WO2018163343A1 - Rotary atomizing head for electrostatic coating machine - Google Patents

Abstract

Provided is a rotary atomizing head for an electrostatic coating machine capable of improving the coating efficiency of a coating material by increasing the amount of charge of the coating material emitted. In an edge region (26) of a rotary atomizing head (14) for an electrostatic coating machine positioned on an outer periphery (21b) of a front surface (21), coating guide grooves (31) are disposed radially and adjacent to each other across the entire circumference. Thus, coating material P1 supplied from a coating discharge hole opened on the front surface (21) side is charged as the material passes through the coating guide grooves (31) and is emitted in a liquid thread form. Furthermore, the coating guide grooves (31) each have a groove end part (33) that is formed into a sharpened shape which has a narrower width nearer to the end edge of the edge region (26). The end edge of the edge region (26) is formed in a serrated shape having teeth (40). The tops E1 of the teeth (40) are disposed in accordance with the position of the groove end parts (33) of the coating guide grooves (31).

Description

Rotating atomizing head for electrostatic coating machine

The present invention relates to a rotary atomizing head used in an electrostatic coating machine from which paint is discharged.

In the painting of objects such as automobile bodies and automobile parts, strict painting quality is required, and electrostatic coating machines capable of performing uniform and high-quality painting are used. This electrostatic coating machine includes a rotary atomizing head, and atomizes and sprays the paint by a centrifugal force generated by rotating the rotary atomizing head.

As shown in FIGS. 14 to 16, in the conventional electrostatic coating machine 51, the paint P supplied from a paint supply device (not shown) passes through a feed tube 53 provided in the coating machine body 52. Then, it is supplied from the paint discharge hole 54 to the front 56 side of the rotary atomizing head 55. In addition, in the edge area | region 57 located in the outer peripheral part of the front surface 56, many paint guide grooves 58 are formed in the state arrange | positioned radially adjacent to each other over the perimeter. When the rotary atomizing head 55 is rotated by the air motor 59 in the coating machine main body 52, centrifugal force acts on the rotary atomizing head 55. As a result, the paint P supplied to the front 56 side of the rotary atomizing head 55 passes through each paint guide groove 58 and is charged and discharged in the form of liquid yarn.

Incidentally, Patent Document 1 discloses a rotating cup (rotating atomizing head) that promotes atomization of paint by forming an outer peripheral portion in a concavo-convex shape and concentrating an electric field on the top of the convex portion. Further, Patent Document 2 discloses an electrostatic coating machine that prevents the generation of bubbles on the coating surface by forming a large number of concave grooves opened at the outer peripheral end on the rotary atomizing head and releasing the paint in the form of liquid thread. Is disclosed.

Japanese Patent Publication No. 36-1266 (Fig. 1 etc.) Japanese Patent Publication No.55-41825 (Fig. 2 etc.)

By the way, in the conventional electrostatic coating machine 51, an electric field acts equally with respect to the whole outer peripheral part of the rotary atomizing head 55. FIG. In addition, the paint P flows to the outer peripheral side of the rotary atomizing head 55 and is charged while being divided by the paint guide groove 58. However, among the electric fields acting on the outer peripheral portion of the rotary atomizing head 55, the electric field acting near the end portion of the paint guide groove 58 contributes to the charging of the paint P, but the electric field acting on other portions is: Since it does not contribute to the charging of the paint P, it is wasted. That is, in the conventional electrostatic coating machine 51, the paint P that has passed through the paint guide groove 58 is not efficiently charged. In this case, since the charge amount of the paint P does not increase so much, there is a problem that the application efficiency of the paint P to the object cannot be sufficiently improved.

Moreover, in patent document 1, a liquid thread-like coating material is discharge | released not only from a convex part but from a recessed part. However, since the electric field does not concentrate in the recess, the amount of charge of the paint released from the recess is reduced. Therefore, also in this case, there is a problem that the coating efficiency of the paint cannot be sufficiently improved. Although Patent Document 2 is a technique for forming a large number of concave grooves on the rotary atomizing head, it is not intended to increase the charge amount, and therefore the coating efficiency of the paint cannot be improved.

The present invention has been made in view of the above-mentioned problems, and its purpose is to rotate an electrostatic coating machine capable of improving the coating efficiency of the paint by increasing the charge amount of the paint to be released. To provide an atomizing head.

In order to solve the above-mentioned problem, the invention described in means 1 comprises a rotating body having a front surface, a back surface and a central axis, and a large number of paint guide grooves are formed over the entire circumference in an edge region located at the outer peripheral portion of the front surface. Electrostatic coating in which the paint supplied from the paint discharge holes formed radially and adjacent to each other and opened on the front side is charged through the paint guide grooves and discharged in the form of liquid threads A rotary atomizing head used in a machine, wherein the plurality of paint guide grooves have groove end portions formed in a sharp shape that becomes narrower toward the edge of the edge region, The edge of the edge region is formed in a sawtooth shape having a plurality of teeth, and the tops of the plurality of teeth are respectively arranged corresponding to the positions of the groove end portions of the plurality of paint guide grooves. For electrostatic coating machines The Utatekiri Kaatama as its gist.

According to the invention described in means 1, since the edge of the edge region located on the outer peripheral portion of the rotary atomizing head is formed in a sawtooth shape having a large number of teeth, the electric field is generated at the top of the teeth. Become focused. In addition, since the top of the tooth portion is arranged corresponding to the position where the end portion of the paint guide groove is located, the paint that has passed through the paint guide groove is guided to the portion where the electric field is concentrated. As a result, the paint passing through the paint guide groove is efficiently charged, and the charge amount of the paint is surely increased, so that the coating efficiency of the paint can be improved.

The outermost ends of the groove end portions in the large number of paint guide grooves may be disposed at the same position as the tops of the large number of tooth portions or closer to the groove start end portions in the large number of paint guide grooves. It is preferable that they are arranged at the same positions as the tops of a large number of teeth. If the end of the groove end is located closer to the groove start end in the paint guide groove than the top of the tooth, even if the paint passes through the paint guide groove and becomes liquid-like, the end of the groove This is because the paint may spread like a film when passing through the region between the extreme end of the part and the top of the tooth part.

Furthermore, it is preferable that the edge part of an edge area | region is exhibiting the cross-sectional shape chamfered in the cut surface parallel to a central axis. In this way, the sharpness of the edge of the edge region is reduced, so that the rotary atomizing head can be handled easily. In addition, the edge of the edge region is less likely to break.

The invention described in means 2 comprises a rotating body having a front surface, a back surface, and a central axis, and a state in which a large number of paint guide grooves are arranged radially and adjacent to each other in the edge region located at the outer peripheral portion of the front surface. Rotating atomizing head used in an electrostatic coating machine in which paint supplied from a paint discharge hole formed on the front side is charged through a plurality of paint guide grooves and discharged in the form of liquid thread The plurality of paint guide grooves have groove end portions formed in a sharp shape that becomes narrower as they approach the edge of the edge region, and the groove end portions in the edge region The gist of the rotary atomizing head for an electrostatic coating machine is characterized in that a recess having a shape recessed toward the groove start end portion of the plurality of paint guide grooves is formed in a region between .

According to the invention described in the means 2, the recesses having a shape recessed toward the groove start end portions of the many paint guide grooves are formed in the region between the groove end portions in the edge region. For this reason, an electric field concentrates on the part which is not a recess in an edge area | region. In addition, since the end portion of the paint guide groove is disposed in a portion that is not a recess in the edge region, the paint that has passed through the paint guide groove is guided to the portion where the electric field is concentrated. . As a result, the paint passing through the paint guide groove is efficiently charged, and the charge amount of the paint is surely increased, so that the coating efficiency of the paint can be improved.

In addition, it is preferable that the amount of depressions in the recess when the front outer peripheral portion is viewed from the front side is smaller than the length of the groove end portion. If it does in this way, formation of a recess becomes easy. Even if the recess is formed, the edge portion of the edge region is not greatly shaved, so that the strength reduction of the rotary atomizing head can be prevented. Furthermore, it is preferable that the maximum depression amount of the recess when the front outer peripheral portion is projected from the front side is equal to or larger than the length of the groove end portion. In this manner, the non-recessed portion in the edge region becomes sharper due to the formation of the concave portion, and the electric field is further concentrated on the non-recessed portion. As a result, the amount of charge of the paint to be released increases more reliably, so that the coating efficiency of the paint is further improved.

As described in detail above, according to the first to seventh aspects of the invention, the coating efficiency of the paint can be improved by increasing the charge amount of the paint to be released.

The whole schematic diagram which shows the coating equipment in this embodiment. Sectional drawing which shows an electrostatic coating machine. The front view which shows the rotary atomization head for electrostatic coating machines. The principal part front view which expands and shows area | region A1 of FIG. The front view which expands and shows area | region A1 further. The fragmentary sectional view which shows a rotary atomization head. The principal part perspective view which expands and shows area | region A2 of FIG. FIG. 7 is an essential part cross-sectional view showing a region A2 of FIG. The fragmentary sectional view which shows a rotary atomization head. The principal part perspective view which expands and shows area | region A3 of FIG. The principal part front view which shows the rotary atomization head in other embodiment. The principal part perspective view which shows the rotary atomization head in other embodiment. The principal part perspective view which shows the rotary atomization head in other embodiment. Sectional drawing which shows the principal part which shows the electrostatic coating machine in a prior art. The front view which shows the rotary atomization head for electrostatic coating machines. The principal part front view which expands and shows the area | region a1 of FIG.

Hereinafter, an embodiment embodying the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a painting facility 1 including an electrostatic coating machine 10. The electrostatic coating machine 10 of the present embodiment is a coating machine for performing coating on an object to be coated such as an automobile body, and is attached to the tip of a robot arm 3 provided in the painting robot 2. Then, when the control device (not shown) drives and controls the robot arm 3, the spraying direction and spraying position of the paint P1 (see FIG. 4) sprayed from the electrostatic coating machine 10 are changed.

As shown in FIG. 2, the electrostatic coating machine 10 includes a cylindrical coating machine main body 11, a cylindrical cylindrical part 13 that is rotated by an air motor 12 provided in the coating machine main body 11, and a cylindrical part 13. A rotary atomizing head 14 provided at the tip and a metal feed tube 15 extending in the axial direction in the cylindrical portion 13 are provided.

In the feed tube 15, a supply path 16 for selectively supplying the paint P <b> 1 and the cleaning agent to the rotary atomizing head 14 is formed. A paint supply device 17 is connected to the base end side of the feed tube 15. The paint supply device 17 is configured to supply a predetermined amount of paint P1 and a cleaning agent to the supply path 16 based on a control signal output from the control device. More specifically, the paint supply device 17 includes a valve, a pipe, and the like that switch the supplied paint P1 to another color paint or cleaning agent. The paint supply device 17 includes a pump for adjusting the supply amount of the paint P1 and the cleaning agent. Further, the coating machine main body 11 is provided with a high voltage generator (not shown) which is a voltage applying means for generating a high voltage (for example, 90 kV). A high voltage is applied to the rotary atomizing head 14 by the high voltage generator, and the paint P1 supplied to the rotary atomizing head 14 is discharged in a charged state.

As shown in FIGS. 2, 3, 6, and 9, the rotary atomizing head 14 has a front surface 21, a back surface 22, and a central axis O1. The rotary atomizing head 14 is a bell cup-shaped rotating body whose base material is a conductive metal material (aluminum in the present embodiment). In addition, a center cone portion 23 is provided at the center of the rotary atomizing head 14 so as to face the tip of the feed tube 15, and the center cone portion 23 is provided with a self-cleaning hole 24 opened on the front 21 side. ing. Further, the rotary atomizing head 14 is provided with a large number of paint discharge holes 25 communicating with the supply path 16. Each paint discharge hole 25 is disposed in the central portion 21 a of the front surface 21 of the rotary atomizing head 14 and opens on the front surface 21 side. The “center portion 21a of the front surface 21” is a portion of the front surface 21 that is orthogonal to the central axis O1, and is a circular region when the rotary atomizing head 14 is viewed from the front surface 21. . Each paint discharge hole 25 is disposed so as to surround the self-cleaning hole 24. Specifically, the paint discharge holes 25 are arranged at equiangular intervals with respect to the central axis O1.

As shown in FIGS. 2 to 9, the edge region 26 is located on the outer peripheral portion 21 b of the front surface 21 of the rotary atomizing head 14. Note that “the outer peripheral portion 21b of the front surface 21” is inclined to the opposite side of the coating machine body 11 by an angle θ1 (0 ° or more and 90 ° or less in the present embodiment) shown in FIG. This is a region that is connected to the central portion 21a via a curved surface. The edge region 26 (outer peripheral portion 21 b) is a region that forms an annular shape when the rotary atomizing head 14 is viewed from the front surface 21.

As shown in FIGS. 4, 5, and 7, the edge region 26 is formed with a large number of paint guide grooves 31 arranged radially and adjacent to each other over the entire circumference. The paint guide grooves 31 are arranged at equiangular intervals with the central axis O1 as a reference. Each paint guide groove 31 extends along the radial direction of the rotary atomizing head 14. Each paint guide groove 31 has a groove center portion 32 and a groove end portion 33, and a region near the central axis O <b> 1 in the groove center portion 32 is a groove start end portion 34. The groove center portion 32 and the groove start end portion 34 are formed in a sharp shape that becomes narrower as it approaches the central axis O1. The groove end portion 33 has a base end portion (an end portion on the central axis O1 side) communicating with the groove center portion 32, and has a sharp shape that becomes narrower as it approaches the end edge portion of the edge region 26. Is formed.

The overall length L1 of the paint guide groove 31 is not less than 1 mm and not more than 10 mm. More specifically, the length L2 of the groove center portion 32 is 0.7 mm or more and 7 mm or less, and the length L3 of the groove end portion 33 is 0.3 mm or more and 3 mm or less. Furthermore, the line width W1 (see FIG. 5) and the depth D1 (see FIG. 7) of the paint guide groove 31 are maximized at the connection portion between the groove center portion 32 and the groove end portion 33. In the present embodiment, the maximum value of the line width W1 of the paint guide groove 31 is 0.1 mm or more and 1 mm or less, and the maximum value of the depth D1 of the paint guide groove 31 is 0.1 mm or more and 2 mm or less.

As shown in FIGS. 4, 5, 7, and 10, the edge of the edge region 26 is formed in a sawtooth shape having a large number of teeth 40. The top portions E <b> 1 of the respective tooth portions 40 are respectively arranged corresponding to positions where the groove terminal portions 33 of the respective paint guide grooves 31 are present. The outermost end E2 of the groove end portion 33 in each paint guide groove 31 is disposed closer to the groove start end portion 34 in each paint guide groove 31 than the top E1 of each tooth portion 40 by 0 mm or more and 1 mm or less. In other words, the extreme end E2 of the groove end portion 33 in each paint guide groove 31 is disposed on the opposite side of the groove end portion 33 in the paint guide groove 31 from the top portion E1, and closer to the central axis O1 than the top portion E1. ing.

In the region between the groove terminal portions 33 in the edge region 26, a recess 41 having a shape recessed toward the groove start end portion 34 in each paint guide groove 31 is formed. Each recess 41 is open at the edge of the edge region 26. In addition, when the outer peripheral part 21b of the front surface 21 is seen from the front 21 side (specifically, the direction orthogonal to the outer peripheral part 21b of the front surface 21), the amount of depression C1 (see FIG. 5) of the recess 41 is It is smaller than the length L3 (0.3 mm or more and 3 mm or less) of the groove terminal portion 33, and is 0.1 mm or more and 2 mm or less in this embodiment. Here, “the amount of depression C1 of the recess 41 when the outer peripheral portion 21b of the front surface 21 is viewed from the front surface 21 side” is visible in the recess 41 when the outer peripheral portion 21b is viewed from the front surface 21 side. The amount of depression only in the part. Furthermore, the maximum depression amount C2 (see FIG. 5) of the recess 41 when the outer peripheral portion 21b of the front surface 21 is projected from the front surface 21 side is equal to the length L3 of the groove terminal portion 33. It is 0.3 mm or more and 3 mm or less.

In addition, as shown in FIGS. 7, 8, and 10, the edge of the edge region 26 has a chamfered portion 43 having a chamfered surface (planar shape) chamfered at a cut surface parallel to the central axis O1. It has a cross-sectional shape. The chamfering depth of the chamfered portion 43 based on the outer peripheral portion of the back surface 22 is 0.05 mm or more and 1 mm or less, and the chamfering angle of the chamfered portion 43 based on the outer peripheral portion of the back surface 22 is 30 ° or more and 90 ° or less. . The chamfered portion 43 of the present embodiment is a C-shaped chamfered portion, but may be an R-shaped (curved) chamfered portion.

Next, a method of forming each paint guide groove 31 and each recess 41 (groove processing method) will be described.

First, a plate material (base material) having a circular shape in plan view made of a conductive metal material (aluminum in the present embodiment) is prepared. In the subsequent groove forming step, a large number of paint guide grooves 31 are formed by performing groove processing using a cutting tool on the region including the edge region 26 in the plate material. Here, in the grooving, the blade of the cutting tool is inclined to the surface of the region including the edge region 26 in a state where the blade of the cutting tool is inclined by 20 ° or more and 80 ° or less with respect to the surface of the region including the edge region 26. It is done by pressing. In the recess forming step after the groove forming step, a large number of recesses 41 are formed by performing groove processing using a cutting tool on a region that becomes the outer peripheral portion of the back surface 22 in the plate material. Here, in the groove processing, the blade of the cutting tool becomes the outer peripheral portion of the back surface 22 in a state where the blade of the cutting tool is inclined by 10 ° or more and 90 ° or less with respect to the surface of the region that becomes the outer peripheral portion of the back surface 22. This is done by pressing against the surface of the area. In this embodiment, the recess forming process is performed after the groove forming process. However, the groove forming process may be performed after the recess forming process. Then, the chamfering part 43 is formed by performing the grinding | polishing process which grind | polishes the outer peripheral part of a board | plate material.

Next, a method for coating an object to be coated using the electrostatic coating machine 10 will be described.

First, a high voltage is applied to the rotary atomizing head 14 by a high voltage generator. In the rotary atomizing head 14 of the present embodiment, since the edge of the edge region 26 is formed in a sawtooth shape having a large number of teeth 40, the electric field is concentrated on the top E1 of the teeth 40. Become. Next, the coating material P <b> 1 is supplied from the coating material supply device 17 to the feed tube 15. At this time, the paint P1 that has passed through the feed tube 15 is guided to the center cone portion 23 of the rotary atomizing head 14. When the paint P1 is supplied, the flow rate of the paint P1 is moderately suppressed. Therefore, the paint P1 passes through the paint discharge hole 25 instead of the self-cleaning hole 24, and enters the front 21 side of the rotary atomizing head 14. Led.

When the rotary atomizing head 14 is rotated by the air motor 12, centrifugal force acts on the rotary atomizing head 14. As a result, the paint P1 supplied to the front 21 side of the rotary atomizing head 14 passes through each paint guide groove 31 from the groove start end 34 toward the groove end 33, and is spread at that time. It becomes a liquid thread shape (see FIG. 4). The paint P1 is charged when passing through the paint guide groove 31. Furthermore, since the paint P1 that has passed through the paint guide groove 31 is guided to the top E1 of the tooth portion 40 where the electric field concentrates, the amount of charge of the paint P1 is reliably increased. Thereafter, the charged paint P1 in the form of liquid yarn is uniformly discharged from the rotary atomizing head 14 to become droplets P2 (see FIG. 4), and adheres to the surface of the object to be coated in the state of the droplets P2. As a result, the article to be coated is painted.

Therefore, according to the present embodiment, the following effects can be obtained.

(1) In the rotary atomizing head 14 for the electrostatic coating machine 10 of the present embodiment, the paint P1 that has passed through the paint guide groove 31 is guided to the top E1 of the tooth portion 40, which is a portion where the electric field concentrates. As a result, the paint P1 that has passed through the paint guide groove 31 is efficiently charged, and the amount of charge of the discharged paint P1 is reliably increased, so that the coating efficiency of the paint P1 on the object can be improved.

(2) In this embodiment, the edge part of the edge area | region 26 located in the front 21 of the rotary atomization head 14 is exhibiting the cross-sectional shape which has the chamfered chamfer part 43 (refer FIG. 8, FIG. 10). . Therefore, the sharpness of the edge of the edge region 26 is reduced, so that the rotary atomizing head 14 can be easily handled.

In addition, you may change this embodiment as follows.

In the rotary atomizing head 14 of the above embodiment, the outermost end E2 of the groove end portion 33 in each paint guide groove 31 is disposed closer to the groove start end portion 34 in each paint guide groove 31 than the top E1 of each tooth portion 40. It had been. However, the extreme end E2 of the groove end portion 33 in each paint guide groove 31 may be arranged at the same position as the top portion E1 of each tooth portion 40.

In the above embodiment, when the outer peripheral portion 21b of the front surface 21 of the rotary atomizing head 14 is viewed from the front surface 21 side, the recess amount C1 of the recess 41 is greater than the length L3 of the groove terminal portion 33 in the paint guide groove 31. (See FIG. 5). However, as shown in FIGS. 11 to 13, the recess amount C3 of the recess 71 may be equal to the length L5 of the groove end portion 63 in the paint guide groove 61. Further, the depression amount C3 may be larger than the length L5 of the groove terminal portion 63. If the amount of depression C1 is made equal to the length L5 or larger than the length L5, the formation of the recess 71 results in a sharper shape in the edge region 26 that is not the recess 71. Further, the electric field is further concentrated on the portion that is not the recess 71. As a result, the charge amount of the paint P1 to be released increases more reliably, so that the coating efficiency of the paint P1 is further improved.

In the above embodiment, the maximum depression amount C2 of the recess 41 when the outer peripheral portion 21b is projected from the front 21 side is equal to the length L3 of the groove terminal portion 33 (see FIG. 5). However, as shown in FIGS. 11 to 13, the maximum depression amount C4 of the recess 71 may be larger than the length L5 of the groove terminal portion 63. Further, the maximum depression amount C4 may be smaller than the length L5 of the groove terminal portion 63. If the maximum depression C4 is larger than the length L5, a portion that is not the recess 71 in the outer peripheral portion of the back surface 22 becomes a sharper shape due to the formation of the recess 71. Therefore, a portion that is not the recess 71 Further, the electric field is concentrated. As a result, the charge amount of the paint P1 to be released increases more reliably, so that the coating efficiency of the paint P1 is further improved. On the other hand, if the maximum depression amount C4 is made smaller than the length L5, the formation of the recess 71 is facilitated. Even if the recess 71 is formed, the edge of the outer peripheral portion of the back surface 22 is not greatly shaved, so that the strength of the rotary atomizing head 14 can be prevented from being lowered.

The rotary atomizing head 14 of the above embodiment is a bell cup-shaped rotating body in which the outer peripheral portion 21b of the front surface 21 is inclined by an angle θ1 (0 ° or more and 90 ° or less) with respect to the central portion 21a. Other shapes may be used.

In the above embodiment, the automobile body is exemplified as the object to be coated by the electrostatic coating machine 10, but the present invention is not limited to this. For example, automobile parts such as bumpers and other parts may be used as the objects to be coated.

Next, in addition to the technical ideas described in the claims, the technical ideas grasped by the embodiment described above are listed below.

(1) In the above means 1, the outermost ends of the groove end portions of the multiple paint guide grooves are arranged closer to the central axis than the tops of the multiple tooth portions. Rotating atomizing head for machine.

(2) In the above means 1, the outermost ends of the groove end portions in the plurality of paint guide grooves are arranged on the opposite side of the groove end portions in the plurality of paint guide grooves from the tops of the plurality of tooth portions. Rotating atomizing head for electrostatic coating machines.

(3) The rotary atomizing head for an electrostatic coating machine according to the above means 1 or 2, wherein the plurality of paint guide grooves extend along a radial direction of the rotary atomizing head.

(4) In the above means 1 or 2, the electrostatic coating machine includes voltage applying means for applying a high voltage to the rotary atomizing head, and the paint that has passed through the many paint guide grooves is charged. A rotary atomizing head for electrostatic coating machines, characterized in that it is released.

10 ... Electrostatic coating machine

14 ... Rotating atomizing head

21 ... Front

21b ... Front outer peripheral part

22 ... Back

25 ... Paint discharge hole

26: Edge region

31, 61 ... Paint guide groove

33, 63 ... end of groove

34 ... groove start end

40 ... tooth part

41, 71 ... recess

C1, C3 ... The amount of depression in the recess

C2, C4 ... Maximum amount of depression in recess

E1 ... Top of teeth

E2 ... the end of the groove end

L3, L5 ... Length of groove end

O1 ... central axis

P1 ... Paint

Claims (7)

It consists of a rotating body having a front surface, a back surface and a central axis, and is formed in a state in which a large number of paint guide grooves are arranged radially and adjacent to each other in the edge region located at the outer peripheral portion of the front surface. A rotary atomizing head used in an electrostatic coating machine in which the coating material supplied from the coating material discharge hole opened through the plurality of coating material guide grooves is charged and discharged in the form of a liquid thread,

The multiple paint guide grooves have groove end portions formed in a sharp shape that becomes narrower as they approach the edge of the edge region,

The edge of the edge region is formed in a sawtooth shape having a large number of teeth,

The tops of the plurality of tooth portions are respectively arranged corresponding to the positions of the groove end portions of the plurality of paint guide grooves.

A rotary atomizing head for electrostatic coating machines.

The outermost ends of the groove end portions in the multiple paint guide grooves are disposed at the same positions as the tops of the multiple tooth portions or closer to the groove start end portions in the multiple paint guide grooves. The rotary atomizing head for an electrostatic coating machine according to claim 1.

3. The rotary atomizing head for an electrostatic coating machine according to claim 1, wherein an edge of the edge region has a cross-sectional shape chamfered along a cutting plane parallel to the central axis. .

It consists of a rotating body having a front surface, a back surface and a central axis, and is formed in a state in which a large number of paint guide grooves are arranged radially and adjacent to each other in the edge region located at the outer peripheral portion of the front surface. A rotary atomizing head used in an electrostatic coating machine in which the coating material supplied from the coating material discharge hole opened through the plurality of coating material guide grooves is charged and discharged in the form of a liquid thread,

The multiple paint guide grooves have groove end portions formed in a sharp shape that becomes narrower as they approach the edge of the edge region,

In the region between the groove end portions in the edge region, a recess having a shape recessed toward the groove start end portion of the multiple paint guide grooves is formed.

A rotary atomizing head for electrostatic coating machines.

5. The rotary mist for an electrostatic coating machine according to claim 4, wherein a recess amount of the recess when the front outer peripheral portion is viewed from the front side is smaller than a length of the groove end portion. Head.

The maximum recess amount of the recess when the front outer periphery is projected from the front side is equal to or greater than the length of the groove end portion. A rotary atomizing head for the electrostatic coating machine described.

The edge part of the said edge area | region is exhibiting the cross-sectional shape chamfered in the cut surface parallel to the said center axis | shaft, For electrostatic coating machines of any one of Claim 4 thru | or 6 characterized by the above-mentioned. Rotating atomizing head.

Images