JP7549368B2 - Flow path switching valve - Google Patents

Description

The present invention relates to a flow path switching valve, and to a flow path switching valve that switches flow paths by rotating and sliding a valve body within a valve chamber.

A type of flow path switching valve that switches flow paths by rotating a cylindrical or ball-shaped valve body is known (see, for example, Patent Document 1).

In this type of flow path switching valve, the valve body is rotated using a rotary drive unit consisting of a motor, drive gear, etc.

JP 2018-115691 A

In a flow path switching valve like the one described above, calibration is performed as appropriate to set the upper and lower limits of the range in which the valve body can be rotated by the motor. For this calibration, it is conceivable to use an absolute angle sensor such as a rotary potentiometer. However, using an absolute angle sensor would increase costs, which would likely lead to an increase in product prices.

The present invention aims to enable calibration of the valve body rotation range while suppressing cost increases.

The flow path switching valve according to the first aspect comprises a valve body in which a valve chamber is formed and inlets and outlets for fluids are formed on the wall surface forming the valve chamber; a valve element having a valve stem, rotatably arranged within the valve chamber and having a flow path; a sealing portion provided to surround the periphery of the opening of the flow path in the valve element and sealing between the inlet and outlet and the valve element with the opening facing the inlet and outlet; and a rotation drive portion that rotates the valve element via the valve stem and is capable of detecting the angular position of the valve element so that the communication state of the multiple inlets and outlets is selectively switched through the flow path of the valve element, and a stopper is provided inside the valve body to limit further rotation of the valve element at least at the upper and lower limits of the valve element rotation range.

In this flow path switching valve, the rotary drive unit rotates the valve body via the valve shaft, thereby switching the flow path of the valve body. In addition, in this flow path switching valve, a stopper provided inside the valve body can limit further rotation of the valve body at least at the upper and lower limits of the valve body rotation range. Since the rotary drive unit can detect the angular position of the valve body, the position where the rotation of the valve body is stopped by the stopper can be detected as the upper or lower limit of the valve body rotation range, and the valve body rotation range can be calibrated. If the angle difference between the upper and lower limits is known, the lower limit can be found from the detected upper limit, and similarly the upper limit can be found from the lower limit. Therefore, compared to using an absolute angle sensor for calibration, it is possible to calibrate the valve body rotation range in the rotary drive unit while suppressing cost increases.

In the second aspect, in the flow path switching valve according to the first aspect, the valve body is provided with a protrusion that protrudes radially outward from the valve body and abuts against the stopper at least at one of the upper and lower limits of the valve body rotation range.

This flow path switching valve has a simple structure in which a protrusion on the valve body abuts against a stopper at at least one of the upper and lower limits of the valve body rotation range, making it possible to calibrate the valve body rotation range at lower cost.

In the third aspect, in the flow path switching valve according to the first or second aspect, the stoppers are provided at both the upper and lower limits of the valve body rotation range.

In this flow path switching valve, stoppers are provided at both the upper and lower limits of the valve body rotation range, so the valve body rotation range can be calibrated by detecting the upper and lower limits even if the angle difference between the upper and lower limits is unknown.

The flow path switching valve of the present invention makes it possible to calibrate the valve body rotation range in the rotary drive unit while suppressing cost increases.

FIG. 2 is a perspective view showing a flow path switching valve according to the embodiment. FIG. 2 is a bottom view showing the flow path switching valve according to the embodiment. 3 is a cross-sectional view taken along the line 3-3 in FIG. 2. FIG. 2 is an exploded perspective view showing the flow path switching valve according to the embodiment. FIG. FIG. 4 is an exploded perspective view showing the valve body and the holder member in an upside-down state. 11 is a cross-sectional view showing a state in which a protruding portion of the valve body is in contact with a stopper that determines the lower limit of a valve body rotation range. FIG. 11 is a cross-sectional view showing a state in which a protruding portion of the valve body abuts against a stopper that determines an upper limit of a rotation range of the valve body. FIG. FIG. 8 is a cross-sectional view showing a state of the valve body corresponding to FIG. 7 . FIG. 8 is a vertical cross-sectional view showing a state of the valve body corresponding to FIG. 7 .

A flow path switching valve 10 according to one embodiment of the present invention will be described with reference to Figures 1 to 3. In each figure, the gaps formed between components and the distances between components may be exaggerated to facilitate understanding of the invention and for convenience in drawing. In this specification, descriptions of positions and directions such as up and down, left and right, front and back, etc. are based on the directional arrows in Figure 1 and do not refer to positions and directions in the actual state of use. In Figure 1, "UP" indicates the upward direction (upper side), "DOWN" indicates the downward direction (lower side), "LH" indicates the leftward direction (left side), "RH" indicates the rightward direction (right side), "FR" indicates the forward direction (front side), and "RR" indicates the rearward direction (rear side). Note that these directions are for convenience only and may differ from the directions when the valve is installed in a vehicle or the like.

(Configuration of flow path switching valve)
Fig. 1 is a perspective view showing the overall configuration of a flow path switching valve 10 according to an embodiment of the present invention. Fig. 2 is a plan view showing the flow path switching valve 10. Fig. 3 is a cross-sectional view taken along the line 3-3 in Fig. 2.

The flow path switching valve 10 is used as a rotary type four-way valve for switching the flow path of a fluid flowing, for example, in the engine room of an automobile. The flow path switching valve 10 has a valve body 14, a valve element 16, a sealing portion 38, and a rotary drive portion 18.

(Valve body)
In Fig. 2, the valve body 14 is composed of a base member 20 and a holder member 21, which are made of, for example, synthetic resin. The base member 20 is open at the bottom, and the holder member 21 is fitted and fixed in the opening. The gap between the base member 20 and the holder member 21 is sealed by, for example, an O-ring 54. As shown in Figs. 6 and 9, a cylindrical valve chamber 12 is formed inside the valve body 14. Inlet and outlet ports 24, 26, and 28 for fluid are formed in the wall surface of the valve chamber 12. The inlet and outlet ports 24, 26 open to face each other in the valve chamber 12. The inlet and outlet port 28 opens in a direction perpendicular to the direction connecting the inlet and outlet ports 24, 26 in a horizontal plane.

In Figures 1 and 2, ports 24A, 26A, and 28A are integrally provided on the outer surface of the base member 20 of the valve body 14 as pipe fittings that communicate with the inlet/outlet 24, 26, and 28. In addition, the outer surface of the base member 20 is provided with a plurality of mounting portions 32 for mounting the flow path switching valve 10 in the engine room of an automobile, etc. In Figure 6, the holder member 21 is integrally provided with an inlet/outlet 29 to the valve chamber 12 and a port 29A as a pipe fitting that communicates with the inlet/outlet 29.

In Figures 3 and 6, the mating portion between the holder member 21 and the base member 20 is sealed, for example, airtight or watertight, by, for example, an O-ring 54. The O-ring 54 is attached, for example, to a groove 56 provided in the holder member 21.

In this embodiment, the holder member 21 and the base member 20 are joined by the screw 25 with the O-ring 54 sandwiched therebetween, but the holder member 21 and the base member 20 may also be joined by welding. If a structure is adopted in which sealing is also ensured by welding, the O-ring 54 is not necessary.

The holder member 21 has a flange 21A, and four through holes 21B are formed in the flange 21A. For example, screws 25 are passed through the through holes 21B. The end surface 20A of the base member 20 against which the flange 21A abuts is formed with a screw hole 20B into which the screw 25 screws. The holder member 21 is fastened to the base member 20 by the screws 25.

Furthermore, for example, two through holes 21C are formed in the flange 21A. A pin 52 (FIG. 6) for positioning is passed through the through hole 21C. A hole 20C that fits the pin 52 is formed in the end surface 20A of the base member 20. The pin 52 is a jig used when assembling the holder member 21 to the base member 20. By inserting the pin 52 that has passed through the through hole 21C of the flange 21A into the hole 20C of the base member 20, the center of the valve chamber 12 of the base member 20 and the center of the holder member 21 can be positioned. This is because, as will be described later, the lower end of the valve body 16 that rotates in the valve chamber 12 is rotationally supported by the inner peripheral surface 21E of the holder member 21.

Furthermore, the flange 21A is provided with, for example, two protrusions 21D that protrude toward the valve body 14. The end face 20A of the base member 20 is formed with a hole 20D into which the protrusion 21D fits. By fitting the protrusion 21D into the hole 20D, it is possible to suppress changes in the alignment over time between the center of the valve chamber 12 of the base member 20 and the center of the holder member 21.

As shown in FIG. 3, the upper wall surface of the valve chamber 12 is provided with a fitting hole 30 through which the valve shaft 48 of the valve body 16 is rotatably inserted. In addition, the base member 20 is provided, for example, integrally with a support portion 15 extending to the opposite side to the port 28A. A rotation drive portion 18 is fixed onto the base member 20 and the support portion 15, for example, using a screw 22.

(Valve body)
3 to 5, the valve body 16 is a member made of, for example, synthetic resin, and is arranged in the valve chamber 12 so as to be rotatable about an axis O1 extending vertically. The upper part of the valve body 16 is pivotally supported in a fitting hole 30 provided in the upper wall surface of the valve chamber 12 via an O-ring 34. The O-ring 34 is attached, for example, to a groove 16A1 formed in the outer circumferential surface of the upper part of the valve body 16. Meanwhile, the lower part of the valve body 16 is pivotally supported on the inner circumferential surface 21E of the holder member 21 via an O-ring 35 (see also FIG. 10). The O-ring 35 is attached, for example, to a groove 16B1 formed in the outer circumferential surface 16B of the lower part of the valve body 16.

The valve body 16 has a generally cylindrical outer peripheral surface 16C centered on the axis O1. The outer peripheral surface 16C is provided in a range of approximately 180°. In other words, the outer peripheral surface 16C is formed in a generally semicircular shape when viewed from the direction of the axis O1. The radius of curvature of the outer peripheral surface 16C is set to be slightly smaller than the radius of the valve chamber 12. A gap S1 is formed between the cylindrical inner wall 12A of the wall surface of the valve chamber 12 and the outer peripheral surface 16C of the valve body 16 (Figures 7 and 8). This gap S1 is also formed between the tip of a protruding portion 16G (described later) and the inner wall 12A of the valve chamber 12. The size of the gap S1 may vary depending on the location.

A flow path (internal flow path) 36 is provided inside the valve body 16 to selectively connect the inlets and outlets 24, 26, 28, and 29 provided in the valve body 14, in other words, to selectively switch the connection state of the inlets and outlets 24, 26, 28, and 29. In detail, the valve body 16 is formed with openings 36A and 36B formed in a direction perpendicular to the direction of the rotation axis O1 of the valve body 16. As shown in FIG. 9, the openings 36A and 36B are perpendicular to each other. The valve body 16 also has an opening 36C formed below the rotation axis O1. The openings 36A, 36B, and 36C are connected to the flow path 36.

A circular recess 16D is formed around the openings 36A and 36B on the outer circumferential surface 16C of the valve body 16, to which the seat members 40 and 42 (described later) are attached. A protrusion 16E for positioning the seat members 40 and 42 is provided, for example, at two or one locations on the inside of the circular recess 16D around the openings 36A and 36B.

A valve shaft 48 is integrally provided on the upper part of the valve body 16. The central axis of the valve shaft 48 is coaxial with the axis O1 of the valve body 16. The valve shaft 48 is provided with a gear portion 48A having unevenness in the circumferential direction, and this gear portion 48A engages with the output portion of the rotation drive unit 18. Between the upper outer peripheral surface 16A and the outer peripheral surface 16C of the valve body 16, a medium diameter portion 16F is provided, which has a larger diameter than the upper outer peripheral surface 16A and a smaller diameter than the outer peripheral surface 16C. A gap S2 is formed between the medium diameter portion 16F and the protrusions that constitute the stoppers 44, 46 described below. The formation of this gap S2 and the above-mentioned gap S1 suppresses the retention of foreign matter in the valve chamber 12.

(Sealing part)
4 and 9, the sealing portion 38 is provided so as to surround the periphery of the openings 36A and 36B of the flow passage 36 in the valve body 16, and is a member that seals between the inlet/outlet 24, 26, and 28 and the valve body 16 in a state in which the openings 36A and 36B face the inlet/outlet 24, 26, and 28, and has, for example, a seat member 40 and an O-ring 42. The seat member 40 and the O-ring 42 are respectively disposed in the two annular recesses 16D of the valve body 16. The seat member 40 is made of, for example, a synthetic resin, and is formed in an annular shape having openings corresponding to the openings 36A and 36B of the flow passage 36 in the valve body 16. The inner diameter of the seat member 40 is set to be equal to the inner diameter of the inlet/outlet 24, 26, and 28, for example.

The surface of the seat member 40 that slides against the inner wall 12A of the valve chamber 12 is a cylindrical surface that runs along the inner wall 12A. This allows the valve body 16 to rotate and slide smoothly within the valve chamber 12 when the seat member 40 is in contact with the inner wall 12A of the valve chamber 12, and allows the valve body 16 to seal between the inlet/outlet 24, 26, 28 and the valve body 16 when the openings 36A, 36B face the inlet/outlet 24, 26, 28. On the other hand, the back surface of the seat member 40 is, for example, substantially flat. A recess 40A that fits with the protrusion 16E of the valve body 16 is formed on this back surface. The O-ring 42 is disposed at the bottom of the annular recess 16D, and the seat member 40 is fitted over the O-ring 42. In other words, the space between the seat member 40 and the valve body 16 is sealed, for example, airtight or watertight, by the O-ring 42.

As an example, a resin with low water absorption such as PPS (polyphenylene sulfide) can be used for the valve body 14 and the valve element 16, a self-lubricating resin such as PTFE (fluororesin) can be used for the seat member 40, and synthetic rubber can be used for the O-ring 42.

(Rotation drive unit)
1 to 3, the rotary drive unit 18 rotates the valve body 16 via a valve shaft 48 so that the communication state of the multiple inlets and outlets 24, 26, 28, and 29 is selectively switched through the flow path 36 of the valve body 16, and is capable of detecting the angular position of the valve body 16. The rotary drive unit 18 has a motor for rotating the valve shaft 48, a drive gear, and the like, and is disposed above the valve body 14 so as to rotate the valve body 16 around a rotation axis (center line) O1 via the valve shaft 48. The valve shaft 48 of the valve body 16 engages with the rotary drive unit 18 around the axis O1. The rotary drive unit 18 is provided with a connector 50 to which, for example, wiring for communication with a control unit and power supply is connected. The motor may be a stepping motor so as to detect the angular position of the valve body 16, or may be a combination of a motor such as a DC motor and a magnetic sensor (for example, a Hall element).

6, 7, and 8, the valve body 16 is rotated within a predetermined valve body rotation range. At least one of, for example both, the upper and lower limits of this valve body rotation range are provided with stoppers 44, 46 inside the valve body 14 to limit further rotation of the valve body 16. Specifically, the stoppers 44, 46 are integrally provided around the insertion hole 30 (FIG. 2) in the upper wall surface of the valve chamber 12. The stopper 44 determines the upper limit, and the stopper 46 determines the lower limit. The upper and lower limits can also be referred to as one end and the other end. In addition, by providing the stoppers 44, 46 inside the valve body 14, i.e., on the upper wall surface of the valve chamber 12, the valve body 16 can be positioned from the lower side of the valve chamber 12.

The valve body 16 is provided with a protrusion 16G that protrudes radially outward from, for example, the medium diameter portion 16F of the valve body 16 and abuts against the stoppers 44, 46 at least at the upper and lower limits of the valve body rotation range, and in this embodiment, at both. The protrusion 16G is, for example, a fan-shaped convex portion in a plan view, and is provided in one location. This protrusion 16G abuts against the stopper 44 at the upper limit of the valve body rotation range and abuts against the stopper 46 at the lower limit. The arrangement of the stoppers 44, 46 and the size of the protrusion 16G in the circumferential direction of the valve body 16 are appropriately changed depending on the valve body rotation range. In other words, the positions of the stoppers 44, 46 are determined taking into account this angle difference and the shape of the protrusion 16G of the valve body 16.

In this embodiment, the angular difference θ between the upper and lower limits of the valve disc rotation range is 270° (Figure 7). When the angular difference between the upper and lower limits of the valve disc rotation range is known, the calibration program can calculate the lower limit from the upper limit, and the upper limit from the lower limit. Therefore, only one of the upper limit stopper 44 or the lower limit stopper 46 may be provided. Also, a protrusion that abuts against the upper limit stopper 44 and a protrusion that abuts against the lower limit stopper 46 may be provided separately.

(Action, Effect)
Next, the operation and effect of the flow path switching valve 10 of this embodiment will be described. In Figures 1 and 3, in this embodiment, the flow path 36 of the valve body 14 can be switched by rotating the valve element 16 via the valve shaft 48 by a rotary drive unit 18 consisting of a motor, a drive gear, etc. Specifically, the communication state of the inlets and outlets 24, 26, 28, and 29 provided in the valve body 14 can be selectively switched through the flow path 36 of the valve element 16.

For example, in Figures 9 and 10, the valve body 16 is at the lower limit of the valve body rotation range, the inlet/outlet 26 and 29 are connected, and the inlet/outlet 24 and 28 are connected. In addition, when the valve body 16 is rotated 90 degrees clockwise from the state in Figure 9, the inlet/outlet 26, 28, and 29 are connected, and the inlet/outlet 24 is closed. When the valve body 16 is further rotated 90 degrees clockwise, the inlet/outlet 24, 28, and 29 are connected, and the inlet/outlet 26 is closed. When the valve body 16 is further rotated clockwise to the upper limit of the valve body rotation range, the inlet/outlet 24 and 29 are connected, and the inlet/outlet 26 and 28 are connected.

In addition, in this embodiment, the stoppers 44, 46 provided on the outside of the valve body 14 can limit further rotation of the valve body 16 at both the upper and lower limits of the valve body rotation range. Specifically, the protrusions 16G of the valve body 16 come into contact with the stoppers 44, 46, respectively, thereby limiting further rotation of the valve body 16.

Since the rotation drive unit 18 can detect the angular position of the valve body 16, the position where the protrusion 16G stops the rotation of the valve body 16 by the stoppers 44, 46 can be detected as the upper or lower limit of the valve body rotation range, and the valve body rotation range can be calibrated. It is desirable to perform the calibration every time the flow path switching valve 10 is used, or irregularly or periodically, such as once a month. Here, an example of the calibration procedure using the protrusion 16G of the valve body 16 and the stoppers 44, 46 will be described with reference to Figures 7 and 8.

When the valve body 16 is rotated counterclockwise by the rotary drive unit 18 (Fig. 1) from a position between the upper and lower limits of the valve body rotation range, the protrusion 16G comes into contact with the lower limit stopper 46 in Fig. 7, and further rotation of the valve body 16 is restricted. At this time, by detecting the stop of the motor of the rotary drive unit 18, it is possible to detect that the valve body 16 has reached the lower limit of the valve body rotation range. Next, when the valve body 16 is rotated clockwise by the rotary drive unit 18 (Fig. 1), the protrusion 16G comes into contact with the upper limit stopper 44 in Fig. 8, and further rotation of the valve body 16 is restricted. At this time, by detecting the stop of the motor of the rotary drive unit 18, it is possible to detect that the valve body 16 has reached the upper limit of the valve body rotation range.

The rotational position of the motor of the rotary drive unit 18 may be detected, for example, using a sensor such as a Hall element, or may be detected from the back electromotive force of a stepping motor or brushless motor. The number of rotations of the motor (i.e., the angular position of the valve body) from the state in which the protrusion 16G abuts against the lower limit stopper 46 or the upper limit stopper 44 can be detected using a sensor, but in the case of a stepping motor, the number of rotations of the motor (i.e., the angular position of the valve body) may also be detected from the number of input pulses. The state in which the protrusion 16G abuts against the lower limit stopper 46 or the upper limit stopper 44 (reference position, motor stopped state) can also be detected from a sensor or back electromotive force.

As a result, the angular position of the valve disc 16 at the rotary drive unit 18 at the upper limit of the valve disc rotation range corresponds to the angular position of the valve disc 16 at the rotary drive unit 18 at the lower limit of the valve disc rotation range, completing the calibration of the valve disc rotation range. This allows the angular position of the valve disc 16 to be changed arbitrarily within the valve disc rotation range.

In this embodiment, since stoppers 44, 46 are provided at both the upper and lower limits of the valve disc rotation range, the valve disc rotation range can be calibrated by detecting the upper and lower limits even if the angular difference between the upper and lower limits is unknown. If the angular difference between the upper and lower limits of the valve disc rotation range is known, the calibration program can calculate the lower limit from the upper limit, and the upper limit can be calculated from the lower limit. Therefore, calibration can be performed even in a configuration in which only the upper limit stopper 44 or the lower limit stopper 46 is provided.

In this manner, in this embodiment, the simple configuration in which the protrusion 16G provided on the valve body 16 abuts against the stoppers 44, 46 at at least one of the upper and lower limits of the valve body rotation range makes it possible to calibrate the valve body rotation range in the rotation drive unit 18 while suppressing cost increases compared to when an absolute angle sensor is used for calibration.

[Other embodiments]
Although one embodiment of the present invention has been described above, the present invention is not limited to the above, and it goes without saying that the present invention can be implemented in various modified forms without departing from the spirit and scope of the present invention.

It goes without saying that the number and arrangement of the inlets and outlets formed in the valve body 14 can be changed as appropriate depending on the application location of the flow path switching valve 10. In the above embodiment, a four-way valve was used as an example of the flow path switching valve 10, but it goes without saying that it may also be, for example, a two-way valve or a three-way valve.

In addition, the flow path switching valve 10 in the above embodiment is intended to be used for flow path switching in the engine room of a vehicle (such as an engine cooling circuit or an electronic device cooling circuit), but the application is not limited to this, and it can of course be used for flow path switching in a hot water supply system, for example.

The valve body 16 is provided with a protrusion 16G that abuts against the stoppers 44, 46, but this is not limited thereto, and any configuration may be used as long as the stoppers 44, 46 can limit further rotation of the valve body 16 at least at one of the upper and lower limits of the valve body rotation range.

10 Flow path switching valve 12 Valve chamber 12A Inner wall (wall surface)
Reference Signs List 14 Valve body 16 Valve element 16G Projection 18 Rotation drive portion 24 Inlet/outlet 26 Inlet/outlet 28 Inlet/outlet 29 Inlet/outlet 36 Flow path 36A Opening 36B Opening 36C Opening 38 Sealing portion 44 Stopper 46 Stopper 48 Valve stem

Claims (3)

a valve body having a valve chamber formed therein and a fluid inlet/outlet formed on a wall surface defining the valve chamber;
a valve body having a valve shaft, rotatably disposed within the valve chamber, and having a flow path;
a sealing portion provided to surround an opening of the flow passage in the valve body, the sealing portion sealing between the inlet/outlet and the valve body in a state in which the opening and the inlet/outlet face each other;
a rotation drive unit that rotates the valve body via the valve shaft so that a communication state of the plurality of inlets and outlets is selectively switched through the flow passage of the valve body, and that is capable of detecting an angular position of the valve body;
Equipped with
A flow path switching valve, comprising: a stopper for limiting further rotation of the valve disc at at least one of an upper limit and a lower limit of a rotation range of the valve disc, the stopper being integrally provided on a wall surface including a cylindrical inner wall of the valve chamber . The flow path switching valve according to claim 1, wherein the valve body is provided with a protrusion that protrudes radially outward from the valve body and abuts against the stopper at least at one of the upper and lower limits of the valve body rotation range. The flow path switching valve according to claim 1 or 2, wherein the stoppers are provided at both the upper and lower limits of the valve body rotation range.