JPH09103716A - Powder spray gun and cap for same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a powder spray gun in which a spray pattern is changed according to the shape of a material to be coated or the like and also provide a cap to be fitted to same. SOLUTION: A cap 10 fitted to the tip part of a nozzle 5 has a shielding part 15 for covering a part of a slit 6 (powder discharge port) of the nozzle 5 and a notch 16 for opening the end part of the slit 6. By rotating the cap 10 around the axial line, the spray pattern is changed into three stages such as small, medium and large patterns.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION This invention relates generally to powder coating, and more particularly to powder coating guns that form elongated spray patterns.

[0002]

BACKGROUND ART Powder coating is drawing attention from the viewpoint of recent environmental problems. This powder coating has the advantage of improving the working environment compared to solution-type coating, and in addition, it collects paint that has not been applied to the object to be coated, that is, oversprayed powder paint, and re-collects it. It is also excellent in terms of effective utilization of resources, that is, it can be used (Japanese Patent Laid-Open No. 64-75057).
No., etc.). A so-called flat spray gun is known as a coating gun used for such powder coating (see Japanese Utility Model Publication No. 4-48827).

[0003]

A flat-spraying gun is one in which paint is sprayed from an elongated paint discharge port (slit) provided at the tip end surface of the nozzle to form an elongated elliptical spray pattern. It is suitable for painting a large flat surface, but when painting a part where multiple surfaces intersect, such as the inner corner of a box-shaped object to be coated, the corner will not be well coated. However, there is a problem that it is difficult to make the finished coating film thickness uniform. Then, the objective of this invention is providing the powder coating gun and the cap for powder coating guns which can change a spray pattern according to the shape etc. of a to-be-coated article.

[0004]

SUMMARY OF THE INVENTION To achieve the above object, the powder coating gun of the present invention is based on the premise that the powder coating gun discharges the powder coating material through a slit formed in the tip surface of a nozzle. A cap rotatably attached to the tip portion of the powder coating gun about an axis line, the cap having a shield portion partially extending from an outer peripheral edge thereof along the tip surface of the nozzle; A configuration is adopted in which the end portion excluding the central portion of the slit is covered with the shielding portion by the rotating operation of the cap.

In the powder coating gun cap of the present invention, the cap is rotatably attached to the tip portion of the powder coating gun for discharging the powder coating material through the slit formed in the tip surface of the nozzle. Therefore, the cap is configured to include a shielding portion that partially extends from the outer peripheral edge of the cap along the tip surface of the nozzle and partially extends in the circumferential direction.

According to the present invention, by adopting the above-mentioned structure, the cap is rotated so that the position of the shielding portion of the cap coincides with the end of the slit of the nozzle which is the discharge port of the powder coating material. Thus, the substantial opening area of the slit can be reduced. As a result, the length of the long and narrow spray pattern can be shortened. For example, when coating the inner surface of a box-shaped object to be coated, the shortened spray is applied to the corner portion where the adhesion of the paint is not preferable. Since it can be applied in a pattern, it becomes easy to obtain a coating film having a uniform film thickness as a whole. Other objects and advantages of the present invention will be apparent from the description of the preferred embodiments below.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the accompanying drawings. First Embodiment (FIGS. 1 to 8) This embodiment shows an example in which the present invention is applied to a powder coating handgun. Referring to FIG. 1, the handgun 1 has a grip 2 and a barrel 3. This handgun 1 has a hose connector 4 at the lower end of the grip 2,
It is connected to a powder supply source (not shown) via a hose (not shown) connected to the connecting tool 4, and a powder quantitative supply device is provided in the middle of the hose. The powder coating material fed into the hand gun 1 through the hose connector 4 reaches the nozzle 5 at the tip of the barrel 3 through the internal powder pipe line (not shown) of the hand gun 1, and the slit of the nozzle 5 is formed. 6 is ejected toward an object to be coated (not shown). Such a handgun 1 is called a so-called flat-blowing gun, and since this flat-blowing handgun is conventionally known, detailed description thereof will be omitted.

2 and 3 are enlarged views of the nozzle 5 of the hand gun 1. As shown in FIG. The slit 6 described above
Diametrically traverses the tip surface 5a of the nozzle 5, and
It extends from the peripheral edge of the tip surface 5a to the tip portion of the side wall portion 5b. In the figure, reference numeral 10 is a cap, and the cap 10 has a body portion 11 having a substantially cylindrical shape.
A large number of vertical grooves 12 are formed on the outer peripheral surface of the main body 11 at equal intervals in the circumferential direction, and an O-ring 13 as a seal member is attached to the inner peripheral surface of the main body portion 11. . The cap 10 is attached to the tip end portion of the nozzle 5 by fitting the main body portion 11 onto the outer peripheral surface of the side wall portion 5b of the nozzle 5.

As can be best understood from FIG. 4, the cap 10 has an extension cylindrical portion 14 slightly extending forward from the main body portion 11, and a nozzle 5 from the tip of the extension cylindrical portion 14.
Two substantially rectangular shielding portions 1 extending along the tip surface 5a of the
5 and the two shielding portions 15 are arranged diametrically opposite to each other. In addition, a total of two notches 16 are formed in the extension cylinder portion 14 of the cap 10 at positions spaced apart by 90 degrees from the shielding portion 15 in the circumferential direction so as to face each other in the diametrical direction. The shielding portion 15 and the notch 16 are respectively
It has a width dimension L2 slightly larger than the width dimension L1 of the slit 6.

In the above structure, the operator appropriately operates the cap 10 to form the spray pattern according to the shape of the object to be coated or the application site. 5-7 show three spray patterns that can be created by manipulating the cap 10. FIG. 5 shows a mode in which the major axis length Lp of the spray pattern 20 is the smallest (hereinafter referred to as a small pattern).
Is shown. FIG. 6 shows a mode in which the major axis length Lp of the spray pattern 20 is medium (hereinafter referred to as medium pattern). FIG.
Shows a mode in which the major axis length Lp of the spray pattern 20 is the largest (hereinafter referred to as a large pattern).

To make a small pattern, an operator rotates the cap 10 about the axis and positions the shield portion 15 so as to cover both ends of the slit 6. This state is shown in FIG. As a result, the slit 6 of the handgun 1, that is, the discharge port, is covered with the cap 10 (the extension cylinder portion 14 and the shielding portion 15) at both end portions thereof except for the central portion in the longitudinal direction, so that the substantial opening area is greatly reduced. As a result, the spray pattern becomes the small pattern 20A (see FIG. 5B).

In order to form a medium pattern, an operator rotates the cap 10 about the axis to separate the shield portion 15 from both ends of the slit 6, and the extension cylinder portion 14 causes both ends of the slit 6 (nozzle 5). Positioning so as to cover the side wall 5b). This state is shown in FIG. As a result, the slit 6 of the handgun 1, that is, the discharge port, is covered at both ends by the cap 10 (extended cylinder portion 14), so that the actual opening area is reduced, and as a result, the spray pattern becomes the middle pattern 20B. (See FIG. 6B).

To make a large pattern, an operator rotates the cap 10 about the axis, and the notch 16 makes the slit 6.
Position so that it matches the both ends of. This state is shown in FIG.
(A) of FIG. As a result, the slit 6 of the handgun 1, that is, the discharge port is not limited by the presence of the cap 10, and as a result, the spray pattern 20 becomes a large pattern 20C (see FIG. 7B).

The specific numerical values shown in FIGS. 5 to 7 are
It is based on the following specifications. (1) Width L1 of slit 6: 4 mm (2) Outer diameter of nozzle 6: 18 mm (3) Width L2 of shielding part 15 of cap 10: 8 mm (4) Length of shielding part 15 of cap 10: 5 mm (5 ) Spacing between opposing shields: 13 mm (6) Powder discharge rate: 150-200 g / min.

FIG. 8 shows a box-shaped article to be coated 21. When applying the inner surface of the box-shaped article to be coated 21 using the hand gun 1 described above, the spray pattern of the gun 1 is set in a large pattern 20C mode and applied to the bottom surface 21a having a relatively large area. For the relatively narrow side surface 21b,
The corner portion 21c, which is set and applied in the mode of the middle pattern 20B and the adhesion of the paint is relatively unfavorable, is small.
It may be applied after setting the aspect A. When the operator selects any of the small pattern 20A, the medium pattern 20B, and the large pattern 20C and sets the spray pattern according to the application location, the powder spray density is almost constant regardless of the spray pattern. The powder discharge amount is adjusted according to each spray pattern. This makes it easy to obtain a uniform coating film thickness as a whole.

The drawings after FIG. 9 show other embodiments of the present invention. Among the elements included in these other embodiments, the same elements as the elements explained in the first embodiment are the same. By attaching the reference numeral of, the detailed description thereof is omitted,
Hereinafter, the characteristic part of each embodiment will be described.

Second Embodiment (FIGS. 9 to 11) This embodiment shows an example in which the present invention is applied to an automatic gun for powder coating, and an example in which the spray pattern is automatically changed. In this sense, it corresponds to the modification of the first embodiment described above.

The automatic painting gun 30 of this embodiment has an actuator 31 on the outer peripheral portion of the barrel 3. The actuator 31 has a pair of operating rods 32 projecting forward from the actuator 31. These two operating rods 32 are spaced apart in the diametrical direction of the barrel 3 and extend parallel to each other. Body part 1 of cap 10
Connected to 1. The actuator 31 can rotate the cap 10 around the axis in two steps at intervals of 90 degrees, whereby the spray pattern of the gun 30 can be the three patterns described above, that is, the small pattern 20A and the middle pattern 20.
B and the large pattern 20C are selectively set. Further, when each spray pattern is set, the powder discharge amount is adjusted so that the powder spray density is constant regardless of which spray pattern is set.

The actuator 31 includes an intermediate plate 33.
Has two outer cylinders 35 and 36 arranged side by side in the axial direction with respect to each other. The outer cylinders 35 and 36 and the intermediate plate 33 form two ring-shaped pressure chambers 37 and 3 extending in the circumferential direction.
8 are formed. In each pressure chamber 37, 38,
A front ring-shaped plate 40 and a rear ring-shaped plate 41 are arranged, and each plate 40, 41 is provided with a projection 42 extending in the axial direction, as can be seen from FIG. 9. Note that the projection of the rear plate 41 is not shown in the drawing for the sake of illustration. Each pressure chamber 37, 38
Respectively, the pressure chambers 37 and 38 are
Each is divided into two chambers in the circumferential direction.

The intermediate plate 33 is integrated with the rear plate 41 by bolts 48 so as to rotate together with the rear plate 41. This rear plate 41
Rotation of the intermediate plate 33, that is, the rotation of the intermediate plate 33,
It is defined by a stopper (not shown) provided on the shielding plate 43 that closes the rear end of the intermediate plate 33, and the rotation region of the intermediate plate 33 is set to 90 degrees around the axis. Further, the rotation of the front plate 40 is performed by the intermediate plate 3
The rotation region of the front plate 40 is defined by the stopper 44 of No. 3 and is set to 90 degrees around the axis.

The rear end of the operation rod 32 described above is fixed to the front plate 40. Each pressure chamber 37, 38
Are provided with first and second air supply / discharge ports 45 and 46, respectively. The first and second ports 45 and 46 are divided by the projection 42 for each pressure chamber 37 and 38. It is set up facing two rooms. Compressed air is selectively fed from a total of four ports 45, 46, whereby the operating rod 32 rotates in two steps at 90-degree intervals. As a result, the cap 10 of the gun 30 is rotated in two steps at 90-degree intervals by the actuator 31, whereby the spray pattern selectively becomes the small pattern 20A, the middle pattern 20B, and the large pattern 20C. The front outer cylinder 35
The groove 47 for passing the operation rod 32 formed in the above is shielded by a sealing rotation plate (not shown).

Third Embodiment (FIGS. 12 to 19) This embodiment shows an example in which the spray pattern can be changed almost continuously. 12 is a front view of the cap for changing the spray pattern, and FIG. 13 is a side view of the cap viewed from the direction of arrow X13 in FIG. The cap 50 of this embodiment is basically the same as the cap 10 described above, but the shape of the shielding portion 15 and the shape of the notch 16 are different.

The two shield portions 15 of the cap 50 have a point-symmetrical shape, and each shield portion 15 has a substantially fan shape. The shape of the shielding portion 15 will be described in detail. In the shielding portion 15, the sandwiching angle Θ (see FIG. 12) of two sides that intersect each other is set to about 150 °, and the intersection of these two sides is the axis of the nozzle 5. One side 15a that is arranged apart from the center O is relatively short, the other side 15b is relatively long, and the relatively short side 15a is the nozzle 5
The slit 6 has a shape extending substantially in line with the wall surface.

The notch 16 has a vertical wall 16a extending straight from a relatively short side 15a of the one shield portion 15, and
It is formed by an inclined wall 16b extending obliquely from a relatively long side 15b of the other shield portion 15.

FIG. 14 shows the relationship between the rotation operation of the cap 50 and the change in the opening area of the slit 6 of the nozzle 5, that is, the discharge port. As can be understood from the figure, the end portions except the central portion of the slit 6 are covered with the shielding portion 15 and / or the extension cylinder portion 14 as the cap 50 rotates, so that the substantial opening area of the slit 6 is reduced. It changes almost steplessly.

15 to 17 show an example of an actuator 60 for rotating the cap 50. The actuator 60 is roughly composed of a cylindrical cylinder 61 arranged on the outer circumference of the barrel 3, a ring-shaped piston 62 fitted and inserted in the cylinder 61, and an integral body of the piston 62 from the cylinder 61. Sliding cylinder 6 extending forward
3 and a rotary cylinder 64 that rotates in relation to the tip of the sliding cylinder 63.

The cylinder 61 has a pressure chamber 65 on the rear side of the piston 62, and a fluid supply / discharge port 66 is provided facing the pressure chamber 65. The port 66 is connected to a compressed air supply source (not shown) as an example of a working fluid source via a hose (not shown), and a exchange valve (not shown) is provided in the hose, By controlling this switching valve, supply and stop of compressed air to the pressure chamber 65,
The compressed air is exhausted from the compression chamber 65.

The sliding cylinder 63 integral with the piston 62 is biased in the retracting direction by a compression coil spring 67. The sliding cylinder 63 has a pair of diametrically opposed long grooves 68, and the long grooves 68 extend straight in the axial direction. A pin 69 is provided so as to penetrate the long groove 68, and the pin 69 is fixed to a base 70 fixed to the outer peripheral surface of the barrel 3. With this configuration, the sliding cylinder 63 is guided by the long groove 68 and the pin 69 and linearly moves in the axial direction.

The rotary cylinder 64 has a pair of circumferential projections 64a formed on the inner surface thereof, and the pair of circumferential projections 64a,
64b are spaced apart in the axial direction and extend parallel to each other. The pair of circumferential protrusions 64 a and 64 b are housed in the circumferential groove 70 a formed on the outer peripheral surface of the base 70, and the rotating cylinder 64
Are guided by the circumferential groove 70a and rotate about the axis.

The rotary cylinder 64 has a cam groove 72 on its outer peripheral surface, and a projection 73 projecting from the inner surface of the sliding cylinder 63 is arranged in the cam groove 72. The linear motion of the sliding cylinder 63 is converted into the rotary motion of the rotary cylinder 64. A pair of connecting rods 75 extending in the radial direction is provided at the tip of the rotary cylinder 64, and the rotary cylinder 64 and the cap 50 are integrated by the connecting rods 75.

18 and 19 show an example in which a coating gun having a cap 50 and an actuator 60 is attached to a reciprocator (not shown). FIG.
As shown in (a) and (b) of the above, as the coating object 80 that moves along the transport path 80 in the coating booth, for example, a plurality of types of coating objects 80 (W1, W2) having different width dimensions W are provided. Even if they are mixed, the cap 50 is appropriately rotated to set the major axis length Lp of the spray pattern 84 so as to substantially match the widths W1 and W2 of the object 80, and the work of coating each object. Therefore, the problem of overspray can be reduced. Similarly, when the shape of the article to be coated 82 is such that the width dimension W changes, such as the barrel shape shown in FIG. 19, the cap 50 is rotated so as to match the width dimension at each part. By applying the coating while changing the spray pattern 84, the problem of overspray can be reduced. 18 and 19, the arrow T indicates the moving direction of the coating gun.

Fourth Embodiment (FIGS. 20 to 22) This embodiment shows another example of an actuator for rotating the cap 50, and in this sense, corresponds to a modification of the third embodiment. 20 is an enlarged perspective view showing a main part of a powder coating gun provided with a cap 50, and FIG. 21 is a vertical sectional view thereof.

The actuator 90 included in this embodiment
Is roughly composed of a pinion 91 rotatably attached to the outer peripheral surface of the barrel 3 and a pair of racks 92 arranged in parallel with the pinion 91 interposed therebetween. It is housed in 93. An inner peripheral portion of the pinion 91 is extended forward in the axial direction, and a flange 94 is formed at a tip end of this extended portion. The flange 94 and the cap 50 are connected to each other by a connecting rod 95.
Are linked by

The rack 92 makes a linear motion by compressed air supplied from a port (not shown), and this linear motion is converted into a rotary motion by the pinion 91. This rotational movement is transmitted to the cap 50 via the connecting rod 95,
This causes the cap 50 to rotate and create the desired spray pattern.

[Brief description of the drawings]

FIG. 1 is a side view of a handgun according to a first embodiment of the present invention.

FIG. 2 is a partial perspective view showing an enlarged tip portion of the handgun of FIG.

FIG. 3 is a sectional view taken along line III-III of FIG. 2;

FIG. 4 is a perspective view of a cap attached to the hand gun according to the first embodiment.

FIG. 5 is an explanatory diagram showing the relationship between the rotational position of the cap of the handgun of the first embodiment and the spray pattern formed thereby, showing a mode of a small pattern.

FIG. 6 is an explanatory diagram showing the relationship between the rotational position of the cap and the spray pattern formed by the same as in FIG. 5, showing a mode of a medium pattern.

FIG. 7 is an explanatory view showing the relationship between the rotational position of the cap and the spray pattern formed by the same as in FIGS. 5 and 6, showing a large pattern mode.

FIG. 8 is an explanatory view showing an example in which a box-shaped object to be coated is coated using the hand gun of the first embodiment.

FIG. 9 is a perspective view showing a distal end portion of an automatic painting gun according to a second embodiment of the present invention and including a partially exploded view of an actuator included therein.

10 is a vertical cross-sectional view of the tip portion of the automatic painting gun of FIG.

11 is a cross-sectional view of the actuator taken along line X11-X11 of FIG.

FIG. 12 is a front view of a cap presented as a third embodiment of the present invention.

13 is a side view of the cap of FIG.

14 is an explanatory diagram showing the relationship between the rotation of the cap of the gun equipped with the cap of FIG. 12 and the change in the effective opening area of the slit of the nozzle.

FIG. 15 is a perspective view of a tip portion of an automatic painting gun as a third embodiment of the present invention, which has an actuator for rotating a cap.

FIG. 16 is a partially cutaway perspective view of the gun shown in FIG.

17 is a vertical cross-sectional view of the tip portion of the gun shown in FIG.

FIG. 18 is a diagram showing an example in which the gun of the third embodiment is attached to a reciprocator and coating is performed by mixing and mixing coating objects having different width dimensions.

FIG. 19 is a diagram showing an example in which the gun of the third embodiment is attached to a reciprocator and an object to be coated having a partially different width dimension is applied.

FIG. 20 shows an embodiment corresponding to a modification of the automatic painting gun of the third embodiment, and is a perspective view of the tip portion of the gun equipped with another type of actuator for rotating the cap.

21 is a cross-sectional view of the tip portion of the coating gun of FIG.

22 is a cross-sectional view taken along line X22-X22 of FIG.

[Explanation of symbols]

 1 Handgun for powder coating 3 Barrel part of handgun 5 Handgun nozzle 5a Nozzle tip surface 6 Slit formed in the nozzle 10 Cap 15 Cap shielding part

Claims (2)

[Claims] 1. A powder coating gun for discharging powder coating material through a slit formed on a tip surface of a nozzle, comprising a cap rotatably attached to a tip portion of the powder coating gun about an axis. The cap includes a shield portion that partially extends from the outer peripheral edge of the cap along the tip surface of the nozzle, and the end portion except the central portion of the slit is covered with the shield portion by the rotating operation of the cap. Characteristic powder coating gun. 2. A cap rotatably attached to a tip end portion of a powder coating gun for discharging powder coating material through a slit formed in a tip end surface of the nozzle, the cap comprising an outer peripheral edge of the nozzle. A powder coating gun cap, comprising: a shield portion that partially extends along a tip surface and partially extends in a circumferential direction.