WO2018190084A1 - Emitter, and tube for drip irrigation - Google Patents

Abstract

This emitter is provided with a water intake part, a discharge part, a flow path, and a check valve. The water intake part takes in an irrigation liquid. The discharge part discharges the irrigation liquid. The flow path connects the water intake part and the discharge part, and circulates the irrigation liquid. The check valve is provided to the flow path, opens the flow path for the irrigation liquid flowing towards the discharge part, and closes the flow path for fluid flowing back through the flow path from the discharge part. The check valve is provided with a valve body and a protrusion. The valve body includes: a fixed end part which is fixed to an inner wall of the flow path; and a free end part which is positioned at the opposite side to the fixed end part. The protrusion protrudes towards the downstream side of the flow path at the free end part.

Description

Emitter and drip irrigation tubes

The present invention relates to an emitter and a drip irrigation tube having the emitter.

Drip irrigation method is known as one of the plant cultivation methods. The drip irrigation method is a method in which a drip irrigation tube is arranged on or in the soil where plants are planted, and irrigation liquid such as water or liquid fertilizer is dropped from the drip irrigation tube to the soil. One advantage of the drip irrigation method is that the consumption of irrigation liquid can be minimized.

A drip irrigation tube is joined to a tube having a plurality of through holes and a plurality of emitters (“drippers”) that are bonded to the inner wall surface of the tube and quantitatively discharge irrigation liquid from each through hole. (For example, refer to Patent Document 1). The irrigation liquid is sent into the tube by, for example, a pump, and discharged from the through hole through the emitter.

The emitter described in Patent Document 1 includes a first member, a second member, and a film member disposed between the first member and the second member. The first member has a water intake for taking in the irrigation liquid into the emitter, and a wall portion arranged to surround the water intake inside the first member. The second member has a discharge port for discharging the irrigation liquid out of the emitter. By laminating the first member, the membrane member, and the second member in this order, there is a flow path through which the flow irrigation liquid can move between the first member and the membrane member and between the second member and the membrane member. It is formed. A through hole is formed in the membrane member for the liquid taken into the emitter from the water intake port to move from the flow path between the first member and the membrane member to the flow path between the second member and the membrane member. Has been.

Further, in the emitter described in Patent Document 1, the water intake is blocked by the membrane member coming into contact with the wall portion. In the emitter, when the pressure of the irrigation liquid in the tube becomes equal to or higher than a predetermined value, the membrane member closing the intake port is pressed by the irrigation liquid and deformed. The irrigation liquid flows into the emitter through a gap formed between the membrane member and the wall due to the deformation of the membrane member.

JP 2010-046094 A

Generally, even after the liquid feeding into the tube is stopped, the irrigation liquid in the tube is continuously discharged for a certain period of time. When drip irrigation tubes are placed at different elevations, the amount of irrigation liquid discharged from lower emitters is higher than the amount of irrigation liquid discharged from higher emitters . As a result, the pressure in the tube at a high position becomes a negative pressure. As a result, a fluid such as air or water containing fine soil from the outside of the tube may flow backward into the flow path of the emitter. As described above, the back flow phenomenon of the fluid that may be caused by the negative pressure in the tube (hereinafter also referred to as “siphon phenomenon”) may contaminate the inside of the emitter or cause clogging.

On the other hand, in the emitter described in Patent Document 1, when the pressure of the irrigation liquid in the tube becomes less than a predetermined value after stopping the liquid feeding, the water intake is blocked by the membrane member. For this reason, in the said emitter, generation | occurrence | production of a siphon phenomenon can be suppressed. Thus, the membrane member described in Patent Document 1 also functions as a backflow prevention valve that prevents the fluid from flowing back from the discharge port to the flow path together with the first member. However, since the backflow prevention valve of the emitter is composed of three members (first member, second member and membrane member), an assembly error may occur.

An object of the present invention is to provide an emitter and a drip irrigation tube that can suppress the occurrence of siphon phenomenon and have a backflow prevention valve composed of one member.

In order to solve the above-described problems, an emitter according to the present invention has a first surface and a second surface that are in a relationship of front and back, and communicates the inside and outside of the tube on the inner wall surface of the tube through which the irrigation liquid flows. And an emitter for quantitatively discharging the irrigation liquid in the tube from the discharge port to the outside of the tube, and disposed on the first surface. A water intake part for taking in the liquid for irrigation, a discharge part arranged on the second surface for discharging the irrigation liquid, and connecting the water intake part and the discharge part to distribute the irrigation liquid A flow path and the flow path that is disposed in the flow path, opens the flow path for the irrigation liquid flowing toward the discharge section, and flows back to the flow path from the discharge section. Close the flow path A backflow prevention valve, the backflow prevention valve including a fixed end fixed to the inner wall of the flow path, and a free end located on the opposite side of the fixed end. A valve body; and a convex portion protruding toward the downstream of the flow path at the free end portion.

In order to solve the above problems, a drip irrigation tube according to the present invention is joined to a tube having a discharge port for discharging irrigation liquid and a position corresponding to the discharge port on the inner wall surface of the tube. And an emitter according to the present invention.

According to the present invention, it is possible to provide an emitter and a drip irrigation tube that have a backflow prevention valve composed of one member and can suppress the occurrence of a siphon phenomenon.

1A and 1B are cross-sectional views showing an example of the configuration of a drip irrigation tube according to Embodiment 1. FIG. 2A to 2C are diagrams showing the configuration of the emitter or emitter body according to Embodiment 1. FIG. FIG. 3 is a cross-sectional view showing the configuration of the emitter according to the first embodiment. 4A to 4C are schematic cross-sectional views for explaining the operation of the flow rate reducing unit and the backflow prevention valve. 5A and 5B are bottom views for illustrating the configuration of a part of the emitter according to Embodiment 2 and for explaining the operation of the check valve.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[Embodiment 1]
(Composition of drip irrigation tube and emitter)
1A and 1B are cross-sectional views showing an example of the configuration of a drip irrigation tube 100 according to Embodiment 1. FIG. FIG. 1A is a cross-sectional view of the drip irrigation tube 100 in the axial direction, and FIG. 1B is a cross-sectional view of the drip irrigation tube 100 in a direction perpendicular to the axial direction. The drip irrigation tube 100 includes a tube 110 and an emitter 120.

The tube 110 is a tube for flowing irrigation liquid. The irrigation liquid is sent into the tube 110 using a pump, for example. A plurality of discharge ports 112 for discharging the irrigation liquid to the outside of the tube 110 at a predetermined interval (for example, 200 to 500 mm) in the axial direction of the tube 110 are formed on the tube wall of the tube 110. The diameter of the opening of the discharge port 112 is not particularly limited as long as the irrigation liquid can pass through. In the present embodiment, the diameter of the opening of the discharge port 112 is 1.5 mm. Emitters 120 are respectively joined to the positions corresponding to the discharge ports 112 on the inner wall surface of the tube 110. The cross-sectional shape and cross-sectional area perpendicular to the axial direction of the tube 110 are not particularly limited as long as the emitter 120 can be disposed inside the tube 110.

The material of the tube 110 is not particularly limited. In the present embodiment, the material of the tube 110 is polyethylene.

Examples of the irrigation liquid include water, liquid fertilizer, agricultural chemicals, and a mixture thereof.

2A to 2C are diagrams showing the configuration of the emitter 120 or the emitter body 121 according to the first embodiment. 2A is a plan view of the emitter body 121, FIG. 2B is a plan view of the emitter 120, and FIG. 2C is a bottom view of the emitter 120. FIG. 3 is a cross-sectional view showing the configuration of the emitter 120 according to the present embodiment. FIG. 3 is a cross-sectional view taken along line AA shown in FIG. 2B.

As shown in FIG. 1A, the emitter 120 is joined to the inner wall surface of the tube 110 so as to cover the discharge port 112. The shape of the emitter 120 is not particularly limited as long as it can adhere to the inner wall surface of the tube 110 and cover the discharge port 112. In the present embodiment, the shape of the back surface of the emitter 120 joined to the inner wall surface of the tube 110 in the cross section perpendicular to the axial direction of the tube 110 is such that the inner wall surface of the tube 110 is aligned with the inner wall surface of the tube 110. It is a substantially circular arc shape convex toward. The shape of the emitter 120 in plan view is a substantially rectangular shape with four corners rounded off. The size of the emitter 120 is not particularly limited. In the present embodiment, the length of the emitter 120 in the long side direction is 25 mm, the length in the short side direction is 8 mm, and the height is 2.5 mm.

The emitter 120 according to the present embodiment includes at least an emitter body 121, a film 122, and a cover 123. Details of the function of the emitter 120 will be described later.

The emitter body 121 (emitter 120) has a first surface 1211 and a second surface 1212 that are in a front-back relationship. In the present embodiment, the first surface 1211 is located on the front surface side (irrigation liquid side) of the emitter 120, and the second surface 1212 is located on the rear surface side (tube 110 side) of the emitter 120.

The emitter body 121 is appropriately formed with recesses, grooves, protrusions, and through-holes within a range where the effects of the present embodiment can be obtained. Although details will be described later, in the present embodiment, at least a water intake recess 153, a flow rate reduction recess 161, and a backflow prevention recess 171 are formed on the first surface 1211 of the emitter body 121 (FIG. 2A). reference). In addition, at least a first connection groove 131, a first decompression groove 132, a second connection groove 133, a second decompression groove 134, and a discharge recess 181 are formed on the second surface 1212 of the emitter body 121 (see FIG. 2C).

The emitter body 121 is made of a material having moderate flexibility. Examples of the material of the emitter body 121 include resin and rubber. Examples of the resin include polyethylene and silicone. The flexibility of the emitter body 121 can be adjusted by using a resin material having elasticity. Examples of the method for adjusting the flexibility of the emitter body 121 include selection of a resin having elasticity, adjustment of a mixing ratio of a resin material having elasticity with respect to a hard resin material, and the like. The emitter body 121 can be manufactured by injection molding, for example.

The film 122 is bonded to a part of the first surface 1211 of the emitter body 121. The film 122 is disposed on the emitter body 121 so as to close the opening of the flow rate reducing recess 161. That is, the film 122 is joined to the emitter main body 121 at a portion outside the opening. The film 122 has flexibility and is deformed by the pressure of the irrigation liquid.

The shape and size of the film 122 can be appropriately set according to the shape and size of the emitter main body 121 and the shape and size of the opening of the flow rate reducing recess 161 formed in the emitter main body 121. The thickness of the film 122 can be appropriately set according to the desired flexibility.

The film 122 is formed of a flexible resin material. The material of the film 122 can be appropriately set according to the desired flexibility. Examples of the resin include polyethylene and silicone. The flexibility of the film 122 can also be adjusted by using a resin material having elasticity. An example of a method for adjusting the flexibility of the film 122 is the same as the method for adjusting the flexibility of the emitter body 121. The film 122 can be manufactured by injection molding, for example.

The emitter body 121 and the film 122 may be integrated or separate. For example, the emitter main body 121 and the film 122 may be integrally formed via a hinge part. The film 122 may be rotated about the hinge portion, and the film 122 may be joined to the first surface 1211 of the emitter body 121. The joining method of the emitter body 121 and the film 122 is not particularly limited. Examples of the joining method include welding of a resin material, adhesion with an adhesive, and the like. The hinge portion may be cut after the emitter body 121 and the film 122 are joined.

The cover 123 is joined to a part of the first surface 1211 of the emitter 121 main body. The cover 123 is disposed on the emitter body 121 so as to close the opening of the backflow preventing recess 171. That is, the cover 123 is joined to the emitter body 121 at a portion outside the opening. The shape and size of the cover 123 can be appropriately set according to the shape and size of the emitter body 121, the shape and size of the opening of the backflow prevention recess 171 formed in the emitter body 121, and the like.

The cover 123 may be formed of a flexible material or may be formed of a rigid material. Examples of the material of the cover 123 include resin, rubber, and metal. Examples of the resin include polyethylene and silicone. The flexibility of the cover 123 is the same as the method for adjusting the flexibility of the emitter body 121. The cover 123 can be manufactured by injection molding, for example. In the present embodiment, cover 123 is formed of a material having rigidity. In the present specification, the “material having rigidity” means a material having a rigidity that prevents a member formed by the material from being deformed by the pressure of the irrigation liquid.

The emitter body 121 and the cover 123 may be integrated or separate. An example of a method for joining the emitter body 121 and the cover 123 is the same as an example of a method for joining the emitter body 121 and the film 122.

The film 122 and the cover 123 may be integrated or separate. When the film 122 and the cover 123 are integral, the film 122 and the cover 123 are both flexible. In the present embodiment, the film 122 and the cover 123 are separate bodies. From the viewpoint of imparting rigidity to the cover 123, the film 122 and the cover 123 are preferably separate.

The drip irrigation tube 100 is manufactured by joining the back surface of the emitter 120 to the inner wall surface of the tube 110. The method for joining the tube 110 and the emitter 120 is not particularly limited. Examples of the bonding method include welding of a resin material constituting the emitter 120 or the tube 110, bonding with an adhesive, and the like. Normally, the discharge port 112 is formed after the tube 110 and the emitter 120 are joined, but may be formed before joining.

The emitter 120 includes a water intake unit 150, a first connection channel 141, a first pressure reduction channel 142, a second connection channel 143, a second pressure reduction channel 144, a flow rate reduction unit 160, a backflow prevention valve 170, and a discharge unit 180. Have. The water intake unit 150 and the flow rate reduction unit 160 are disposed on the surface of the emitter 120 (the first surface 1211 of the emitter body 121). Further, the first connection channel 141, the first decompression channel 142, the second connection channel 143, the second decompression channel 144, and the discharge unit 180 are provided on the back surface of the emitter 120 (the second surface 1212 of the emitter body 121). Has been placed. The backflow prevention valve 170 is disposed in a through hole that opens to the first surface 1211 and the second surface 1212.

When the emitter 120 and the tube 110 are joined to each other, the first connection channel 141, the first decompression channel 142, the second connection channel 143, the second decompression channel 144, and the discharge unit 180 are formed. In the emitter 120, a flow path that connects the water intake unit 150 and the discharge unit 180 is also formed. The flow channel distributes the irrigation liquid from the water intake unit 150 to the discharge unit 180.

The water intake unit 150 takes the irrigation liquid into the emitter 120. The water intake 150 is disposed in a region that is approximately half of the first surface 1211 of the emitter body 121 (see FIGS. 2A and 2B). The water intake unit 150 includes a water intake side screen unit 151 and a water intake through hole 152.

The water intake side screen unit 151 prevents the suspended matter in the irrigation liquid taken into the emitter 120 from entering the emitter 120. The water intake side screen portion 151 is open to the inside of the tube 110 and has a water intake recess 153, a plurality of slits 154, and a plurality of screen ridges 155.

The water intake recess 153 is a recess formed in a region where the film 122 is not joined on the first surface 1211 of the emitter body 121. The depth of the water intake recess 153 is not particularly limited, and is appropriately set according to the size of the emitter 120. A plurality of slits 154 are formed on the outer peripheral wall of the water intake recess 153, and a plurality of screen ridges 155 are formed on the bottom surface of the water intake recess 153. In addition, a water intake through hole 152 is formed on the bottom surface of the water intake recess 153.

The plurality of slits 154 connect the inner surface of the water intake recess 153 and the outer surface of the emitter body 121, while taking the irrigation liquid from the side surface of the emitter body 121 into the water recess 153. Is prevented from entering the water intake recess 153. The shape of the slit 154 is not particularly limited as long as the above function can be exhibited. In the present embodiment, the shape of the slit 154 is formed such that the width increases from the outer surface of the emitter body 121 toward the inner surface of the water intake recess 153 (see FIGS. 2A and 2B). Thus, since the slit 154 is configured to have a so-called wedge wire structure, the pressure loss of the irrigation liquid flowing into the water intake recess 153 is suppressed.

The plurality of screen ridges 155 are arranged on the bottom surface of the water intake recess 153. The arrangement and number of the screen ridges 155 are not particularly limited as long as the irrigation liquid can be taken in from the opening side of the water intake recess 153 and the intrusion of suspended matter in the irrigation liquid can be prevented. In the present embodiment, the plurality of screen ridges 155 are arranged such that the major axis direction of the screen ridges 155 is along the minor axis direction of the emitter 120. Further, the screen protrusion 155 is formed so that the width decreases from the first surface 1211 of the emitter body 121 toward the bottom surface of the water intake recess 153. That is, in the arrangement direction of the screen ridges 155, the space between the adjacent screen ridges 155 has a so-called wedge wire structure. Moreover, the space | interval between the adjacent protruding item | line parts 155 for screens will not be specifically limited if the above-mentioned function can be exhibited. In this way, the space between the adjacent screen ridges 155 is configured to have a so-called wedge wire structure, so that the pressure loss of the irrigation liquid flowing into the water intake recess 153 is suppressed.

The water intake through hole 152 is formed on the bottom surface of the water intake recess 153. The shape and number of the water intake through holes 152 are not particularly limited as long as the irrigation liquid taken into the water intake recess 153 can be taken into the emitter body 121. In the present embodiment, the water intake through hole 152 is a single long hole formed along the major axis direction of the emitter 120 on the bottom surface of the water intake recess 153. Since this long hole is partially covered with the plurality of screen ridges 155, the water intake through hole 152 is divided into a large number of through holes when viewed from the first surface 1211 side. appear.

The irrigation liquid that has flowed through the tube 110 is taken into the emitter main body 121 while the water intake side screen portion 151 prevents floating substances from entering the water intake recess 153.

The first connection flow path 141 (first connection groove 131) is disposed in the flow path, and includes the water intake section 150 (water intake through hole 152) and the first pressure reduction flow path 142 (first pressure reduction groove 132). Connecting. The first connection channel 141 (first connection groove 131) is linearly arranged along the major axis direction of the emitter 120 at the outer edge portion of the second surface 1212 of the emitter body 121. By joining the tube 110 and the emitter 120, the first connection channel 141 is formed by the first connection groove 131 and the inner wall surface of the tube 110. The irrigation liquid taken in from the water intake unit 150 flows through the first connection channel 141 to the first decompression channel 142.

The first decompression flow path 142 (first decompression groove 132) is disposed downstream of the first connection flow path 141 in the flow path, and is connected to the first connection flow path 141 (first connection groove 131) and the second connection flow. The path 143 (second connection groove 133) is connected. The first reduced pressure channel 142 reduces the pressure of the irrigation liquid introduced from the water intake unit 150 and guides it to the second connection channel 143. The first decompression flow path 142 (first decompression groove 132) is linearly disposed along the major axis direction of the emitter 120 at the outer edge portion of the second surface 1212 of the emitter body 121. In the present embodiment, the upstream end of the first decompression flow path 142 is connected to the first connection flow path 141, and the downstream end of the first decompression flow path 142 is connected to the upstream end of the second connection flow path 143. ing.

The shape of the first decompression groove 132 is not particularly limited as long as the above function can be exhibited. In the present embodiment, the plan view shape of the first decompression groove 132 is a zigzag shape. In the first decompression groove 132, first triangular protrusions 1361 having a substantially triangular prism shape protruding from the inner surface are alternately arranged along the direction in which the irrigation liquid flows. The first convex portion 1361 is disposed so that the tip does not exceed the central axis of the first decompression groove 132 when viewed in plan. By joining the tube 110 and the emitter 120 to each other, the first decompression channel 142 is formed by the first decompression groove 132 and the inner wall surface of the tube 110. The irrigation liquid taken in from the water intake 150 is decompressed by the first decompression channel 142 and guided to the second connection channel 143 (second connection groove 133).

The second connection channel 143 (second connection groove 133) is disposed downstream of the first decompression channel 142 in the channel, and the first decompression channel 142 (first decompression groove 132) and the second decompression channel The flow path 144 (second decompression groove 134) is connected. The second connection channel 143 is formed linearly along the minor axis direction of the emitter 120 at the outer edge of the second surface 1212 of the emitter body 121. By joining the tube 110 and the emitter 120, the second connection channel 143 is formed by the second connection groove 133 and the inner wall surface of the tube 110. The irrigation liquid that has been taken in from the water intake unit 150, led to the first connection channel 141, and decompressed in the first decompression channel 142 is guided to the second decompression channel 144 through the second connection channel 143. It is burned.

The second decompression flow path 144 (second decompression groove 134) is disposed downstream of the second connection flow path 143 in the flow path, and includes a second connection groove 133 (second connection flow path 143) and a flow rate reduction unit. 160 is connected. The second decompression flow path 144 reduces the pressure of the irrigation liquid flowing from the second connection flow path 143 and guides it to the flow rate reduction unit 160. The second decompression flow path 144 (second decompression groove 134) is disposed along the major axis direction of the emitter 120 at the outer edge portion of the second surface 1212 of the emitter body 121. The upstream end of the second decompression groove 134 is connected to the downstream end of the second connection groove 133, and the downstream end of the second decompression flow path 144 is connected to the first connection through hole 164 of the flow rate reducing unit 160. .

The shape of the second decompression groove 134 is not particularly limited as long as the above function can be exhibited. In the present embodiment, the plan view shape of the second decompression groove 134 is a zigzag shape similar to the shape of the first decompression groove 132. In the second decompression groove 134, substantially triangular prism-shaped second protrusions 1362 protruding from the inner surface are alternately arranged along the direction in which the irrigation liquid flows. The second convex portion 1362 is arranged so that the tip does not exceed the central axis of the second decompression groove 134 when viewed in plan. By joining the tube 110 and the emitter 120, the second decompression channel 144 is formed by the second decompression groove 134 and the inner wall surface of the tube 110. The irrigation liquid taken in from the water intake unit 150 is decompressed by the first decompression channel 142 and the second decompression channel 144 and guided to the flow rate reduction unit 160.

The flow rate reducing unit 160 is disposed downstream of the second decompression flow channel 144 and upstream of the backflow prevention valve 170 in the flow channel, and is disposed on the surface side of the emitter 120. The flow rate reduction unit 160 sends the irrigation liquid to the backflow prevention valve 170 while reducing the flow rate of the irrigation liquid according to the deformation of the film 122 due to the pressure of the irrigation liquid in the tube 110.

The configuration of the flow reduction unit 160 is not particularly limited as long as the above function can be exhibited. In the present embodiment, the flow rate reducing portion 160 includes a flow rate reducing recess 161, a valve seat portion 162, a communication groove 163, a first connection through hole 164, a second connection through hole 165, and a diaphragm portion 166.

The flow rate reducing recess 161 is disposed on the first surface 1211 of the emitter body 121. The plan view shape of the flow rate reducing recess 161 is not particularly limited, and is, for example, a substantially circular shape. The depth of the flow rate reducing recess 161 is not particularly limited as long as it is equal to or greater than the depth of the communication groove 163. A first connection through hole 164 and a second connection through hole 165 are open on the inner surface of the flow rate reducing recess 161. In the present embodiment, the first connection through hole 164 and the second connection through hole 165 are open to the bottom surface of the flow rate reducing recess 161.

The valve seat 162 is arranged on the bottom surface of the flow rate reducing recess 161. In the present embodiment, the valve seat portion 162 is disposed in a non-contact manner so as to face the diaphragm portion 166 so as to surround the opening portion of the second connection through hole 165. The valve seat 162 is configured so that the diaphragm 166 can be in close contact when the pressure of the irrigation liquid flowing through the tube 110 exceeds a set value. When the diaphragm portion 166 contacts the valve seat portion 162, the flow rate of the irrigation liquid flowing from the flow rate reducing recess portion 161 into the backflow prevention valve 170 is reduced.

The shape of the valve seat portion 162 is not particularly limited as long as the above-described function can be exhibited. In the present embodiment, the valve seat portion 162 is a cylindrical convex portion. In the present embodiment, the height of the end surface of the convex portion from the bottom surface of the flow rate reducing concave portion 161 decreases from the inside toward the outside.

The communication groove 163 communicates the inside of the flow rate reducing recess 161 with the second connection through hole 165 surrounded by the valve seat 162. The communication groove 163 is disposed on a part of the surface of the valve seat portion 162 to which the diaphragm portion 166 can come into close contact.

The first connection through-hole 164 communicates with the upstream side of the flow path at the flow rate reducing portion 160. In the present embodiment, the first connection through hole 164 communicates with the second reduced pressure channel 144 (second reduced pressure groove 134). The first connection through hole 164 is disposed on the inner surface of the flow rate reducing recess 161. The first connection through-hole 164 is disposed, for example, on the bottom or surface of the flow rate reducing recess 161. In the present embodiment, the first connection through-hole 164 is disposed in a region where the valve seat 162 is not disposed on the bottom surface of the flow rate reducing recess 161.

The second connection through-hole 165 communicates with the downstream side of the flow path in the flow rate reduction unit 160. In the present embodiment, the second connection through-hole 165 communicates with the backflow prevention valve 170. The second connection through-hole 165 is disposed on the inner surface of the flow rate reducing recess 161. The second connection through hole 165 is disposed on the bottom surface or the side surface of the flow rate reducing recess 161, for example. In the present embodiment, the second connection through-hole 165 is disposed at the central portion of the bottom surface of the flow rate reducing recess 161.

Note that the positions of the first connection through holes 164 and the second connection through holes 165 are not limited to the form of the present embodiment. For example, instead of the first connection through hole 164, a second connection through hole 165 may be disposed outside the valve seat portion 162. Further, instead of the second connection through hole 165, the first connection through hole 164 may be disposed so as to be surrounded by the valve seat portion 162.

The diaphragm portion 166 is a part of the film 122. The diaphragm portion 166 is disposed so as to block communication between the inside of the flow rate reducing recess 161 and the inside of the tube 110 and close the opening of the flow rate reducing recess 161. The diaphragm portion 166 has flexibility and deforms so as to contact the valve seat portion 162 in accordance with the pressure of the irrigation liquid in the tube 110. For example, the diaphragm portion 166 is distorted to the flow rate reducing recess 161 side when the pressure of the irrigation liquid flowing in the tube 110 exceeds a set value. Specifically, the diaphragm portion 166 deforms toward the valve seat portion 162 as the pressure of the irrigation liquid increases, and eventually comes into contact with the valve seat portion 162. Even when the diaphragm portion 166 is in close contact with the valve seat portion 162, the diaphragm portion 166 does not block the first connection through hole 164, the second connection through hole 165, and the communication groove 163. The irrigation liquid from the connection through hole 164 can be sent to the backflow prevention valve 170 through the communication groove 163 and the second connection through hole 165.

The backflow prevention valve 170 is disposed downstream of the flow rate adjustment unit 160 and upstream of the discharge unit 180 in the flow path. The backflow prevention valve 170 opens the flow path for the irrigation liquid flowing toward the discharge section 180 and closes the flow path for the fluid flowing back from the discharge section 180 to the flow path. As a result, the backflow prevention valve 170 sends the irrigation liquid to the discharge unit 180, and the fluid flowing back from the discharge unit 180 to the flow path when the liquid supply is stopped flows to the upstream of the backflow prevention valve 170. Stop.

A viewpoint of suppressing the inside of the channel in the component for adjusting the discharge amount of the irrigation liquid from the emitter 120 from being contaminated or clogged by the fluid flowing backward from the discharge unit 180 into the channel. Therefore, it is preferable that the backflow prevention valve 170 is disposed on the downstream side of the flow path. That is, the backflow prevention valve 170 is preferably disposed downstream of the component for adjusting the discharge amount, and more preferably disposed at a position directly communicating with the discharge unit 180. In the present embodiment, since the backflow prevention valve 170 is disposed downstream of the flow rate adjustment unit 160, the fluid that has flowed back into the flow path does not flow into the flow rate adjustment unit 160.

The configuration of the backflow prevention valve 170 is not particularly limited as long as the above function can be exhibited. In the present embodiment, the backflow prevention valve 170 includes a backflow prevention recess 171, a valve body 172, a fixing portion 174, and a third connection through hole 175.

The backflow preventing recess 171 is disposed on the first surface 1211 of the emitter body 121. The shape in plan view of the backflow preventing recess 171 is not particularly limited. In the present embodiment, the backflow preventing recess 171 has a substantially circular circular portion and a protruding portion protruding from the circular portion in a plan view. The depth of the backflow preventing recess 171 is not particularly limited. The depth of the circular portion and the depth of the protruding portion may be the same or different from each other. In the present embodiment, the depth of the circular portion and the depth of the protruding portion are the same.

A part of the bottom of the backflow prevention recess 171 is constituted by a valve body 172 and a fixing part 174. In the present embodiment, the bottom of the circular portion of the backflow preventing recess 171 is constituted by a valve body 172 and a fixing portion 174. A third connection through-hole 175 is open on the inner surface of the backflow prevention recess 171. In the present embodiment, the third connection through hole 175 is disposed on the bottom surface of the protruding portion of the backflow prevention recess 171.

The valve element 172 is deformed downstream in accordance with the pressure of the irrigation liquid flowing toward the discharge unit 180. On the other hand, the valve body 172 does not deform toward the upstream depending on the pressure of the fluid flowing backward from the discharge part 180 to the flow path. The valve body 172 is arrange | positioned so that a flow path may be block | closed with the fixing | fixed part 174. FIG. The upstream and downstream sides of the valve body 172 in the flow path communicate with each other through a gap formed between the valve body 172 and the fixing portion 174 in the open state of the flow path.

The position of the valve body 172 is not particularly limited as long as the flow path can be opened and closed according to the pressure of the irrigation liquid in the flow path. In the present embodiment, valve body 172 is arranged in a portion of the flow path that extends along the opposing direction of first surface 1211 and second surface 1212. That is, the valve body 172 is disposed in a through hole that opens to the first surface 1211 and the second surface 1212.

The number, shape, and size of the valve body 172 are not particularly limited as long as the above functions can be exhibited. In the present embodiment, the planar view shape of the valve body 172 is a fan shape. The number of valve bodies 172 is two. The two valve bodies 172 are arranged so as to be in contact with each other at a portion corresponding to the fan-shaped apex.

The valve body 172 includes a fixed end portion fixed to the inner wall of the flow path and a free end portion located on the opposite side of the fixed end portion. The fixed end is fixed to the side surface of the flow path (the inner wall surface of the flow path groove). In the present embodiment, the fixed end portion is an arc-shaped portion in the fan-shaped valve body 172. The free end is the tip (top) of the fan-shaped valve body 172. In the state where the flow path is closed, the upstream edge of the valve body 172 is in contact with the downstream edge of the fixing portion 174.

A convex portion 173 that protrudes downstream of the flow path is formed at the free end portion of the valve body 172. In the present embodiment, the convex portion 173 is formed on each of the free end portions of the two valve bodies 172.

The convex part 173 is a thick part of the valve body 172. When the irrigation liquid flows back into the flow path from the discharge part 180 side, the two convex parts 173 press each other. That is, the convex portion 173 of one valve body 172 functions as a valve seat with respect to the other valve body 172. Thereby, it can prevent that a flow path is unintentionally opened due to the deformation | transformation to the upstream of the valve body 172. FIG. From the viewpoint of more reliably preventing the backflow of fluid, it is preferable that the two convex portions 173 are in contact with each other even in a state where the valve body 172 is not deformed. That is, the surface of the convex portion 173 on the side of the free end is preferably the end surface of the free end of the valve body 172.

The number, shape, and size (thickness) of the convex portions 173 can be appropriately changed according to the number, shape, and size of the valve body 172. In the present embodiment, the number of convex portions 173 is two. The planar view shape of the convex part 173 is a right-angled isosceles triangle. Examples of the three-dimensional shape of the convex portion 173 include a triangular pyramid shape and a triangular prism shape. In the present embodiment, the three-dimensional shape of the convex portion 173 is a substantially triangular pyramid shape protruding toward the second surface 1212.

The thickness of the convex portion 173 (the length of the convex portion 173 in the flow direction of the irrigation liquid) may or may not be constant. From the viewpoint of more reliably closing the flow path, it is preferable that the convex portion 173 includes a portion where the thickness of the convex portion 173 increases in the valve body 172 from the fixed end portion toward the free end portion. Thereby, the two convex parts 173 can press each other on a wider surface by the pressure of the fluid that flows back into the flow path from the discharge part 180 side. Further, when the surface of the convex portion 173 on the fixed end side receives the pressure of the fluid, a force in a direction along the opposing direction of the two convex portions 173 is applied to the convex portion 173, and as a result, the two convex portions 173. Can press each other with a stronger force.

The thickness of the portion of the valve body 172 where the convex portion 173 is not formed is sufficiently thinner than the thickness of the fixed portion 174. The thickness of the portion only needs to be appropriately deformable according to the pressure of the irrigation liquid in the flow path, and can be adjusted as appropriate according to the material of the emitter body 121 and the like.

Both the planar view shape of the valve body 172 and the planar view shape of the fixing portion 174 are fan-shaped. The shapes of the valve body 172 and the fixing portion 174 are the same as the fan shape that can be formed by dividing the circular shape into four equal parts. The valve bodies 172 and the fixing portions 174 are alternately arranged along the circumferential direction. The valve body 172 and the fixing portion 174 are adjacent to each other.

The fixing portion 174 is a convex portion protruding from the inner wall of the flow channel toward the center of the flow channel. The fixing portion 174 is hardly deformed by the pressure of the irrigation liquid in the flow path. The number, shape, and size of the fixing portions 174 can be appropriately adjusted according to the number, shape, and size of the valve body 172. In the present embodiment, the number of fixing portions 174 is two. In the present embodiment, the planar view shape of the fixing portion 174 is a fan shape. The two fixing portions 174 are arranged so as to be in contact with each other at a portion corresponding to the fan-shaped apex. The planar view shape of the fixing portion 174 is the same as the planar view shape of the valve element 172. The downstream edge of the fixed portion 174 is in contact with the upstream edge of the valve body 172. The thickness of the fixing portion 174 may be adjusted as appropriate as long as the fixing portion 174 is hardly deformed by the pressure of the irrigation liquid in the flow path.

The third connection through-hole 175 communicates with the upstream side of the flow path in the backflow prevention valve 170. In the present embodiment, the third connection through hole 175 communicates with the flow rate reducing unit 160. The third connection through hole 175 is disposed on the inner surface of the backflow prevention recess 171. The third connection through-hole 175 is disposed, for example, on the bottom surface or side surface of the backflow prevention recess 171. In the present embodiment, the third connection through hole 175 is disposed on the bottom surface of the protruding portion of the backflow prevention recess 171.

The discharge unit 180 discharges the irrigation liquid to the outside of the emitter 120. The discharge unit 180 is disposed on the second surface 1212 side of the emitter body 121 so as to face the discharge port 112 of the tube 110. The discharge unit 180 sends the irrigation liquid in the emitter 120 to the discharge port 112 of the tube 110. Accordingly, the discharge unit 180 can discharge the irrigation liquid to the outside of the emitter 120. The structure of the discharge part 180 will not be specifically limited if the above-mentioned function can be exhibited. In the present embodiment, the discharge unit 180 includes a discharge recess 181 and an intrusion prevention unit 182.

The discharge recess 181 is disposed on the second surface 1212 of the emitter body 121. A part of the bottom of the discharge recess 181 is configured by a valve body 172 and a fixing portion 174. The shape of the discharge recess 181 in plan view is a substantially rectangular shape. A valve body 172, a fixing portion 174, and an intrusion prevention portion 182 are disposed on the bottom surface of the discharge recess 181.

The intrusion prevention unit 182 prevents intrusion of foreign matter from the discharge port 112. The intrusion prevention unit 182 is not particularly limited as long as it can perform the above-described function. In the present embodiment, intrusion prevention unit 182 is four convex portions arranged adjacent to each other. The four convex portions are arranged so as to be positioned between the valve body 172 and the discharge port 112 when the emitter 120 is joined to the tube 110.

[Operation of drip irrigation tube]
Next, the operation of the drip irrigation tube 100 will be described.

First, irrigation liquid is fed into the tube 110. The pressure of the irrigation liquid fed to the drip irrigation tube 100 is preferably 0.1 MPa or less so that the drip irrigation method can be easily introduced and the tube 110 and the emitter 120 are prevented from being damaged. . The irrigation liquid in the tube 110 is taken into the emitter 120 from the water intake unit 150. Specifically, the irrigation liquid in the tube 110 enters the water intake recess 153 through the slit 154 or the gap between the screen protrusions 155 and passes through the water intake through hole 152. At this time, since the water intake part 150 has the water intake side screen part 151 (gap between the slit 154 and the projection ridge part 155), it is possible to remove the suspended matter in the irrigation liquid. Moreover, since the so-called wedge wire structure is formed in the water intake part 150, the pressure loss of the irrigation liquid flowing into the water intake part 150 is suppressed.

The irrigation liquid taken from the water intake unit 150 reaches the first connection channel 141. The irrigation liquid that has reached the first connection channel 141 passes through the first decompression channel 142 and reaches the second connection channel 143. The irrigation liquid that has reached the second connection channel 143 flows into the second decompression channel 144. The irrigation liquid that has flowed into the second reduced pressure channel 144 flows into the flow rate reduction unit 160 through the first connection through hole 164. The irrigation liquid that has flowed into the flow reduction unit 160 flows into the backflow prevention valve 170 through the second connection through hole 165 and the third connection through hole 175. The irrigation liquid that has flowed into the backflow prevention valve 170 deforms the valve body 172 of the backflow prevention valve 170 toward the downstream side, and passes through a gap formed between the valve body 172 and the fixing portion 174, and the discharge unit 180. Flow into. The irrigation liquid that has flowed into the discharge unit 180 is discharged out of the tube 110 from the discharge port 112 of the tube 110.

(Operation of flow reduction part and check valve)
Here, the operation of the flow rate reduction unit 160 and the backflow prevention valve 170 according to the pressure of the irrigation liquid in the tube 110 will be described. 4A to 4C are schematic cross-sectional views for explaining the operation of the flow rate reducing unit 160 and the backflow prevention valve 170. FIG. 4A to 4C are partially enlarged sectional views taken along line AA shown in FIG. 2B. 4A is a cross-sectional view when the irrigation liquid is not supplied to the tube 110, and FIG. 4B is a cross-sectional view when the pressure of the irrigation liquid in the tube 110 is the first pressure. FIG. 4C is a cross-sectional view when the pressure of the irrigation liquid in the tube 110 is the second pressure exceeding the first pressure.

The flow rate reducing portion 160 and the backflow prevention valve 170 communicate with each other via the second connection through hole 165 and the third connection through hole 175. In the flow rate reduction unit 160, the flow rate of the irrigation liquid is controlled by deforming the diaphragm unit 166 so as to be distorted toward the flow rate reduction concave portion 161 according to the pressure of the irrigation liquid in the tube 110. In the backflow prevention valve 170, the valve body 172 is deformed so as to be distorted downstream in accordance with the pressure of the irrigation liquid in the flow path, and the flow path is opened. In the present embodiment, since the cover 123 is made of a rigid material, it is not deformed by the pressure of the irrigation liquid.

Before the irrigation liquid is fed into the tube 110, the pressure of the irrigation liquid is not applied to the film 122, so the diaphragm portion 166 is not deformed (see FIG. 4A). Further, since the valve body 172 is not deformed, the flow path is closed in the backflow prevention valve 170.

When the irrigation liquid starts to flow into the tube 110, the diaphragm 166 and the valve body 172 begin to deform (see FIG. 4B). When the diaphragm portion 166 is not in contact with the valve seat portion 162, the irrigation liquid taken in from the water intake portion 150 passes through the flow path in the emitter 120 and is discharged from the discharge port 112 of the tube 110 to the outside. The At this time, the valve body 172 of the check valve 170 is distorted downstream. At this time, a gap is formed between the valve body 172 and the fixed portion 174. Thereby, in the backflow prevention valve 170, the flow path is opened for the irrigation liquid flowing toward the discharge unit 180, and the irrigation liquid can move toward the discharge unit 180. As described above, when the irrigation liquid is started to be fed into the tube 110 or when the pressure of the irrigation liquid in the tube 110 is lower than a predetermined pressure, the irrigation introduced into the emitter 120 from the water intake unit 150. The working liquid is discharged outside through the flow path.

When the pressure of the irrigation liquid in the tube 110 is further increased, the diaphragm portion 166 is further deformed toward the valve seat portion 162. Normally, as the pressure of the irrigation liquid increases, the amount of the irrigation liquid flowing through the flow path should increase. However, in the emitter 120 according to the present embodiment, the first pressure reduction flow path 142 and the second pressure reduction liquid are increased. By reducing the pressure of the irrigation liquid in the flow path 144 and reducing the distance between the diaphragm portion 166 and the valve seat portion 162, an excessive increase in the amount of the irrigation liquid flowing in the flow path is prevented (FIG. 4B). When the pressure of the irrigation liquid in the tube 110 is equal to or higher than a predetermined value (second pressure), the diaphragm portion 166 contacts the valve seat portion 162 (see FIG. 4C). Even in this case, the diaphragm portion 166 does not block the first connection through-hole 164, the second connection through-hole 165, and the communication groove 163. Therefore, the irrigation liquid introduced from the water intake portion 150 is not connected to the communication groove. Through 163, the liquid is discharged from the discharge port 112 of the tube 110 to the outside. As described above, when the pressure of the irrigation liquid in the tube 110 is equal to or higher than the second pressure, the flow reduction unit 160 makes the irrigation liquid flowing through the flow path when the diaphragm unit 166 contacts the valve seat 162. Suppresses increase in liquid volume.

As described above, the flow rate reducing unit 160 adjusts the flow rate of the irrigation liquid discharged from the discharge port 112 of the tube 110 in accordance with the deformation of the film 122 due to the pressure of the irrigation liquid in the tube 110. For this reason, the drip irrigation tube 100 according to the present embodiment can discharge a certain amount of irrigation liquid out of the tube 110 regardless of whether the pressure of the irrigation liquid is low or high.

(Function of backflow prevention valve)
Here, the function of the check valve 170 will be further described. First, for comparison, a comparative emitter without the backflow prevention valve 170 will be described. As described above, when the drip irrigation tube is arranged at a place with a difference in elevation, when the liquid supply of the irrigation liquid into the tube 110 is stopped, the amount of the irrigation liquid discharged from the emitter at the high position And the amount of irrigation liquid discharged from the emitter at a low position. As a result, due to the difference in height, the inside of the tube 110 has a negative pressure. As a result, in the drip irrigation tube having the comparative emitter, fluid such as air or water containing fine soil from the outside of the tube. In some cases, a so-called siphon phenomenon occurs that flows backward in the flow path of the emitter.

In contrast, the emitter 120 according to the present embodiment has a backflow prevention valve 170. After stopping the liquid supply of the irrigation liquid into the tube 110, the pressure of the irrigation liquid in the flow path decreases, so that the valve deformed toward the downstream side of the flow path in the open state of the flow path. The body 172 returns to the state before deformation. Thereby, the flow path is closed in the check valve 170. Furthermore, even if the inside of the tube 110 becomes negative pressure, the adjacent convex portions 173 press each other so that the valve body 172 does not deform toward the upstream. For this reason, even if the fluid flows backward from the discharge part 180 to the flow path, the closed state of the flow path is maintained. As a result, it is possible to prevent a fluid such as air or water containing fine soil existing outside the tube 110 from flowing upstream of the valve body 172.

(effect)
As described above, the emitter 120 according to the present embodiment has the backflow prevention valve 170 including the valve body 172. Thereby, in the emitter 120, generation | occurrence | production of a siphon phenomenon can be suppressed. Therefore, according to the drip irrigation tube 100 having the emitter 120 according to the present embodiment, it is possible to suppress the occurrence of clogging of the flow path due to the siphon phenomenon even in a place with a height difference. Moreover, since the backflow prevention valve 170 can be comprised by one member, the emitter main body 121 can be comprised by integral molding.

[Embodiment 2]
5A and 5B are bottom views for illustrating the configuration of a part of the emitter 220 according to the second embodiment and for explaining the operation of the backflow prevention valve 270. 5A is a bottom view when the irrigation liquid is not fed to the tube 110, and FIG. 5B is a bottom view when the pressure of the irrigation liquid in the tube 110 is equal to or higher than a predetermined value. .

The emitter 220 according to the second embodiment includes an emitter body 221 and a film 122, and includes a water intake unit 150, a first connection channel 141, a first decompression channel 142, a second connection channel 143, and a second decompression. A flow path 144, a flow rate reduction unit 160, a backflow prevention valve 270, and a discharge unit 180 are included. The emitter 220 according to the second embodiment differs from the emitter 120 according to the first embodiment only in the configuration of the backflow prevention valve 270 and the point that the cover 123 is not provided. Therefore, the same components as those of the emitter 120 according to the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

The emitter body 220 is the same as the emitter body 120 in the first embodiment, except that the configuration of the backflow prevention valve 270 is different from the backflow prevention valve 170 in the first embodiment. In the second embodiment, the backflow prevention valve 270 has a backflow prevention recess 271 and two valve bodies 272.

The backflow preventing recess 271 is arranged on the second surface 1212 of the emitter body 221. The backflow prevention recess 271 is disposed adjacent to the discharge recess 181. The shape in plan view of the backflow preventing recess 271 is not particularly limited. In the present embodiment, the shape of the backflow preventing recess 271 is substantially rectangular. A second connection through-hole 165 is open on the inner surface of the backflow prevention recess 271. In the present embodiment, the second connection through hole 165 is disposed on the bottom surface of the backflow prevention recess 271. The second connection through-hole 165 opens to the inner surface of the flow rate reducing recess 161 and the inner surface of the backflow prevention recess 271.

The depth of the backflow prevention recess 271 is substantially the same as the length of the valve body 272 in the depth direction of the backflow prevention recess 271. Thereby, when the valve body 272 is disposed in the recess 271 for preventing backflow, the flow path can be blocked. As a result, the flow path can be opened and closed by the deformation of the valve body 272 due to the pressure of the irrigation liquid.

The valve body 272 is deformed downstream in accordance with the pressure of the irrigation liquid flowing toward the discharge unit 180. On the other hand, the valve body 272 is not deformed upstream by the fluid flowing backward from the discharge part 180 to the flow path. As described above, the two valve bodies 272 are disposed so as to block the flow path. The upstream and downstream of the valve body 272 in the flow path communicate with each other through a gap formed between the two valve bodies 172 in the open state of the flow path.

In Embodiment 2, the valve body 272 is disposed in a portion of the flow path that extends along the surface direction of the second surface 1212. That is, the valve body 272 is disposed in the backflow prevention recess 271 whose opening is disposed on the second surface 1212.

The number, shape, and size of the valve body 272 are not particularly limited as long as the above functions can be exhibited. In this Embodiment, it is a plate | board shape which becomes wide as it approaches a front-end | tip part (free end part). The number of valve bodies 272 is two. The two valve bodies 272 are disposed so as to be in contact with each other at the distal end portion.

The valve body 272 includes a fixed end fixed to the inner wall of the flow path and a free end positioned on the opposite side of the fixed end. The fixed end portion is fixed to the side surface of the flow path. In the present embodiment, the fixed end portion is a base end portion of the plate-shaped valve body 272. The upper surface of the valve body 272 is in contact with the inner wall surface of the tube 110, and the lower surface of the valve body 272 is in contact with the bottom surface of the backflow prevention recess 271. The free end is the tip (top) of the plate-shaped valve body 272.

A convex portion 273 that protrudes toward the downstream side of the flow path is formed at the free end portion of the valve body 272. In the present embodiment, the convex portion 273 is formed on each of the free end portions of the two valve bodies 272.

The convex part 273 is a thick part of the valve body 272. When the irrigation liquid flows back into the flow path from the discharge unit 180 side, the two convex portions 273 are pressed against each other. That is, the convex part 273 of one valve body 272 functions as a valve seat with respect to the other valve body 272. Thereby, it can prevent that a flow path is unintentionally opened due to the deformation | transformation to the upstream of the valve body 272. FIG. From the viewpoint of more reliably preventing the backflow of fluid, it is preferable that the two convex portions 273 are in contact with each other even in a state where the valve body 272 is not deformed. That is, the surface of the convex portion 273 on the free end side is preferably the end surface of the free end portion of the valve body 272.

The number, shape, and size (thickness) of the convex portions 273 can be appropriately changed according to the number, shape, and size of the valve body 272. In the present embodiment, the number of convex portions 273 is two. The planar view shape of the convex part 273 is a trapezoid. An example of the three-dimensional shape of the convex portion 273 is a polygonal column shape. In the present embodiment, the three-dimensional shape of the convex portion 273 is a quadrangular prism shape.

The thickness of the convex portion 273 (the length of the convex portion 273 in the flow direction of the irrigation liquid) may or may not be constant. From the viewpoint of more reliably closing the flow path, the convex portion 273 preferably includes a portion where the thickness of the convex portion 273 increases in the valve body 272 from the fixed end portion toward the free end portion. Thereby, the two convex parts 273 can press each other on a wider surface by the pressure of the fluid that flows back into the flow path from the discharge part 180 side. Further, when the surface of the convex portion 273 on the fixed end portion side receives the pressure of the fluid, a force in a direction along the facing direction of the two convex portions 273 is applied to the convex portion 273, and as a result, the two convex portions 273. Can press each other with a stronger force.

The thickness of the portion of the valve body 272 where the convex portion 273 is not formed is only required to be appropriately deformable according to the pressure of the irrigation liquid in the flow path, and is appropriately determined according to the material of the emitter body 221 and the like. Can be adjusted.

In the valve body 272 according to the second embodiment, a convex portion 273 that protrudes to the downstream side of the flow path is formed. Thereby, similarly to the valve body 172 in Embodiment 1, it can prevent that the valve body 272 deform | transforms to an upstream side, and can prevent the open | release of the flow path unintentionally (refer FIG. 5A and B). That is, the valve body 272 can also open the flow path for the irrigation liquid flowing toward the discharge unit 180 and close the flow path for the fluid that flows backward from the discharge unit 180 to the flow path.

(effect)
The emitter 220 and drip irrigation tube according to the second embodiment have the same effects as the first embodiment. In the second embodiment, the valve body 272 is disposed in the backflow prevention recess 271 disposed on the second surface 1212 of the emitter body 221. Since the opening of the backflow prevention recess 271 is closed by the inner wall surface of the tube 110, a separate member (the cover 123 in Embodiment 1) for closing the opening of the backflow prevention recess 271 is not required. Therefore, the second embodiment is more preferable from the viewpoint of reducing the number of components of the emitter 220.

In the emitters 120 and 220 according to the first and second embodiments, the case where the number of the valve bodies 172 and 272 in the backflow prevention valves 170 and 270 is two has been described. However, the configuration of the emitter according to the present invention is It is not limited to an aspect. For example, the number of valve bodies may be one or three or more. When the number of valve bodies is one, the inner wall of the flow path functions as a valve seat.

The configurations of the emitter and the drip irrigation tube according to the present invention are not limited to the emitters 120 and 220 and the drip irrigation tube 100 according to the first and second embodiments. For example, the emitter is the first decompression channel. 142, the second decompression flow path 144, and the flow rate adjustment unit 160 may not be provided. In this case, the emitter is constituted by at least an emitter body and a cover.

In the first and second embodiments, the emitters 120 and 220 and the tube 110 are joined, so that the first connection channel 141, the first decompression channel 142, the second connection channel 143, and the second decompression flow. Although the aspect in which the path 144 is formed has been described, the first connection flow path 141, the first pressure reduction flow path 142, the second connection flow path 143, and the second pressure reduction flow path 144 are previously provided as flow paths in the emitter 120. It may be formed.

Furthermore, in the first embodiment, the emitter 120 having the fixing portion 174 has been described. However, the emitter according to the present invention may not have the fixing portion 174.

This application claims priority based on Japanese Patent Application No. 2017-078670 filed on Apr. 12, 2017. The contents described in the application specification and the drawings are all incorporated herein.

According to the emitter according to the present invention, it is possible to suppress the occurrence of clogging caused by the backflow of the fluid outside the tube to the flow path even in a place with a height difference. Therefore, further development of drip irrigation is expected.

100 Tube for drip irrigation 110 Tube 112 Discharge port 120, 220 Emitter 121, 221 Emitter body 1211 First surface 1212 Second surface 122 Film 123 Cover 131 First connection groove 132 First pressure reduction groove 133 Second connection groove 134 Second pressure reduction Groove 1361 First convex part 1362 Second convex part 141 First connection flow path 142 First decompression flow path 143 Second connection flow path 144 Second decompression flow path 150 Water intake part 151 Water intake side screen part 152 Water intake through hole 153 Water intake Recessed portion 154 Slit 155 Screen convex portion 160 Flow rate reducing portion 161 Flow rate reducing recess portion 162 Valve seat portion 163 Communication groove 164 First connection through hole 165 Second connection through hole 166 Diaphragm portion 170, 270 Backflow prevention valve 171 , 271 Backflow recess 172, 272 Valve 173,273 protrusions 174 fixed portion 175 third connecting holes 180 discharge portion 181 the discharge recess 182 intrusion preventing portion

Claims (7)

A first surface and a second surface that are in a front-back relationship with each other, and are joined to a position corresponding to a discharge port that communicates the inside and outside of the tube on the inner wall surface of the tube through which the irrigation liquid flows. An emitter for quantitatively discharging the irrigation liquid from the discharge port to the outside of the tube;
A water intake section disposed on the first surface for taking in the irrigation liquid;
A discharge part disposed on the second surface for discharging the irrigation liquid;
A channel for connecting the water intake unit and the discharge unit, and for distributing the irrigation liquid;
The flow path is disposed in the flow path, opens the flow path with respect to the irrigation liquid flowing toward the discharge section, and closes the flow path with respect to a fluid flowing backward from the discharge section to the flow path. A backflow prevention valve for
Have
The backflow prevention valve is
A valve body including a fixed end fixed to the inner wall of the flow path, and a free end positioned on the opposite side of the fixed end;
In the free end portion, a convex portion protruding toward the downstream of the flow path,
Having
Emitter. The emitter according to claim 1, wherein the convex portion includes a portion whose thickness increases from the fixed end portion toward the free end portion. The emitter according to claim 2, wherein a surface of the convex portion on the free end side is an end surface of the valve body on the free end side. The number of the backflow prevention valves is plural,
In the state where the flow path is closed, the convex portions of the plurality of backflow prevention valves are in contact with each other.
The emitter according to any one of claims 1 to 3. The backflow prevention valve according to any one of claims 1 to 4, wherein the backflow prevention valve is disposed in a portion of the flow path that extends along a facing direction of the first surface and the second surface. Emitter. The emitter according to any one of claims 1 to 5, wherein the backflow prevention valve is disposed in a portion of the flow path extending along a surface direction of the second surface. A tube having a discharge port for discharging irrigation liquid;
The emitter according to any one of claims 1 to 6, joined at a position corresponding to the discharge port on the inner wall surface of the tube;
Having a drip irrigation tube.

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