JPH0463742B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention bypasses a first on-off valve that opens and closes an air flow path and a throttle section that is interposed in the air flow path and reduces the pressure of high-pressure air that is pumped. The present invention relates to a painting spray gun that can spray high-pressure, low-pressure discharge air in two stages and increase its versatility by providing a second on-off valve in a branch flow path.

[Conventional technology]

Traditionally, paint spray guns are number one on the trigger index.
A two-stage blower is used in which only pressurized air is discharged by the first operation, and the paint is applied by the second operation of the trigger index, and the first operation releases the surge air pressure to the outside air. This prevents excessive discharge of paint that occurs during the early stages of relief application, and also blows away foreign matter such as dust that adheres to the coated surface.

However, such conventional spray guns use high-pressure air of 6 to 7 kg/cm ² , which is usually generated by an air compressor, as pressurized air to relatively low pressure air, such as 2 to 3 kg/cm 2, which is suitable for applying paint. The problem was that the duster was used at a reduced pressure of cm ² and therefore did not function adequately as a duster for blowing away foreign matter.

In particular, high quality is required when applying a mold release agent to a molding die, and in order to completely remove foreign matter from the applied surface, high-pressure duster air of, for example, 6 to 7 kg/cm ² is required. Therefore, a duster and a high-pressure air source are newly required in addition to the paint spray gun, making the equipment large-scale and becoming a factor in increasing costs.

The present invention is based on the fact that a second on-off valve is provided in a branch flow path that bypasses a first on-off valve that opens and closes an air flow path and a constriction section that is interposed in the air flow path and reduces the pressure of high-pressure air that is pumped. The object of the present invention is to provide a spray gun for painting which can discharge two types of air, high pressure and low pressure, and which can solve the above-mentioned problems.

[Means for solving problems]

An embodiment of the present invention will be described below based on the drawings.

The painting spray gun 1 of the present invention includes a first on-off valve 6 for opening and closing an upper air flow path 3 leading to a high-pressure air source and a lower air flow path 5 leading to an air cap 4;
The upper air flow path 3 and the lower air flow path 5 including the on-off valve 6
A second opening/closing valve 9 is provided to open and close the branch passage 7 that bypasses the upper air passage 3 and the lower air passage 5, while a constriction valve 9 is provided in the joint passage portion 10 of the upper air passage 3 and the lower air passage 5 that is bypassed by the branch passage 7. 11 are provided.

In this example, the painting spray gun 1 includes a piston-shaped gun body 13 having a neck portion 17 and a handle 19 at the front and rear of a copper portion 16 that straddles a central notch portion 15.
and a needle valve 20 which is pivotally supported by the copper part 16 and hangs down between the neck part 17 and the handle 19 and passes through the notch part 15.
and a first on-off valve 6 protruding from the handle 19, and an air cap 4 attached to the neck 17 for spraying paint.

The needle valve 20 has a paint nozzle 2 screwed onto the neck 17.
The paint discharge port 26 formed at the tip of the center hole of 5 is opened as it moves forward, and consists of the center hole, an inner hole 27 in the neck 17, and a side hole 30 communicating from the inner hole 27 to the paint nipple 29. The coating material flowing through the coating material channel 31 is discharged.

The paint nipple 29 is electrically connected to a paint feeder such as a paint pump for pumping the paint.

The needle valve 20 protrudes into the notch 15 and is slidably attached at its terminal end by a support fitting 33 having a reduced diameter portion 33A at the center and one end screwed into a hole 32 provided at the rear of the gun body 13. It is movably penetrated.
Further, the needle valve 20 is attached to the front by a spring piece 36 disposed between an adjusting screw 35 screwed into the rear end of the hole 32, and the needle valve 20 is moved backward by screwing the adjusting screw 35 forward and backward. You can adjust the amount. The needle valve 20 passes through the paint flow path 31 and opens and closes the paint discharge port 26 at its front end by moving forward and backward.

In addition, the through hole 3 is formed in the hole portion 32 at the reduced diameter portion 33A.
9 is bored, and the through hole 39 communicates with an air passage 40 provided in the gun body 13.

The air passage 40 includes a blind hole 42 extending along the handle 19 from an air nipple 41 at the lower end of the handle 19.
and an upright 46 that communicates with the terminal end of the blind hole 42 and extends to a horizontal hole 45 provided below the hole 32 with an air adjustment control valve 43 interposed therebetween; Conduction hole 39 from the front of hole 45
Diagonal hole 4 leading to air hole 47 passing through copper part 16
9, an air hole 47, and an air passage 53 leading from the tip of the air hole 47 through a circumferential groove 50, a small 51 around the paint nozzle 25, and an air outlet 52 at the tip of the air cap 4. It is formed by path 5. Note that the air passage 53 extends from the air hole 47 to the circumferential groove 5.
5. A pattern flow path 58 is provided which communicates with the pattern hole 57 of the air cap 4 through a notch 56 provided in the flange around the paint nozzle 25. The air hole 47 has a valve shaft 59 that approaches and moves away from the tapered portion at the tip, and an adjustment screw 60 for adjusting the pattern that controls the amount of air flowing into the pattern hole 57 is provided at the rear of the upper end of the handle.

Further, a first on-off valve 6 having a shaft 67 projecting forward of the handle 19 is installed in the horizontal hole 45.

The horizontal hole 45 has a small diameter portion 4 in front of the base hole portion 45A.
5B is a stepped hole having a large diameter part 45C with an internal thread threaded on the rear side, and a sleeve 63 and a receiving metal fitting 65 are inserted into the small diameter part 45B with a seal interposed therebetween, and the large diameter part 62 A valve seat 66 is screwed into the front.

The shaft rod 67 includes a truncated conical valve portion 67B that widens toward the rear at the rear end of the valve shaft portion 67A.
A is inserted into the sleeve 63 and the receiving fitting 65 while being sealed, and the valve portion 67B is engaged with the tapered portion 66A at the rear end of the valve seat 66. Further, in front of the tapered portion 66A, the valve seat 66 is formed with a constricted portion 11 having an appropriate gap and into which the valve shaft portion 67A is loosely inserted.

A spring piece is arranged between the shaft rod 67 and the cap 69 at the rear end of the horizontal hole 45, and the valve part 67B is connected to the tapered part 66A.
By pressing the taper portion 66A, the upper air flow path 3 and the lower air flow path 5 can be disconnected, and by pulling the trigger 21 with your finger, the shaft rod 67 can be disconnected.
is retreated and connects the upper air flow path 3 and the lower air flow path 5.

Further, a push button type second on-off valve 9 is screwed into a hole 70 which is open on both sides of the handle 19 and communicates with the upright hole 46 .

As shown in FIG. 2, in this example, the hole 70 is
A small-diameter screw portion 71 disposed approximately in the center, a large-diameter screw portion 72 and a large-diameter hole portion 73 are provided on both sides of the small-diameter screw portion 71, and the small-diameter screw portion 71 is electrically connected to the rising hole 46, and the large-diameter screw portion 71 is electrically connected to the upright hole 46. The diameter hole portion 73 and the base hole portion 45A of the horizontal hole 45 are communicated through a guide hole 75.

In this example, the second on-off valve 9 includes a support cylinder 77 having a center hole 76 and a valve shaft 79 passing through the center hole 76.
A push button metal fitting 80 is provided.

The support tube 77 has a threaded portion 77A at its tip screwed into the small diameter threaded portion 71, and a collar portion 77 at its rear end.
B is locked in the large diameter hole 73 with a sealing effect. Further, between the threaded portion 77A and the collar portion 77B, there are a plurality of circumferential holes 81 extending from the center hole 76 toward the circumferential surface.
... will be established.

The push button fitting 80 is arranged to be slidable on the inner peripheral surface of the flange portion 77B, and the valve stem 79 is sealed to the flange portion 77B at the base portion 79A. Also push button metal fittings 80
The spring piece 82 disposed between the valve shaft 79 and the flange 77B biases the valve shaft 79 outward, so that the sealing material 83
The valve portion 79B can close the opening end 86 of the center hole 76, and the push button of the push button fitting 80 can close the opening end 86 of the center hole 76.
When the valve shaft 79 retreats, the opening end 86
to open. Note that a nut fitting 85 is screwed into the large-diameter screw portion 73 of the hole 70 to seal one end of the hole 70.

Therefore, the hole 70 and the conduction 75 can form a branch flow path 7 that includes the first on-off valve 6 and bypasses the upper air flow path 3 and the lower air flow path 5, and also includes the second on-off valve 6. 9 can open and close the branch flow path 77 at the open end 86. Further, the parallel passage portion 10 of the air passage 40 that is bypassed by the branch passage 7, that is, in this example,
an intersection P between the upright hole 46 and the hole 70;
As described above, the constriction section 11 is provided between the intersection Q of the horizontal hole 45 and the guide 75, and the constriction section 11 can reduce the pressure of the high-pressure air being pumped.

[Effect]

By indexing the trigger 21, the shaft 67 is moved back and the tapered portion 66A of the valve seat 66 is opened. Note that due to this opening, for example, 6
High-pressure air of ~7 kg/cm ² passes through the upper air flow path 3 and flows into the tapered portion 66A.

The inflowing high-pressure air is controlled to an appropriate discharge pressure, for example 2 to 3 Kg/
The air passes through the lower air flow path 5 and is ejected from the air outlet 52 and pattern hole 57 while being reduced in pressure to cm ² .

Furthermore, by further indexing the trigger 21, the needle valve 20 is moved back and the paint discharge port 26 is opened.

Therefore, the coating material from the coating material supply tool passes through the coating material flow path 31 and flows out from the coating material discharge port 26, and the above-mentioned 2 to 3 kg/
Atomized by air with a discharge pressure of cm ² .

Furthermore, by pressing the push button fitting 80 prior to operating the trigger 21, the second on-off valve 9 is opened, and the first on-off valve 6 and the throttle portion 11 are bypassed through the branch flow path 7. Therefore, the high-pressure air forced into the air nip 41 passes through the upper air flow path 3, the branch flow path 7, and the lower air flow path 5, and is ejected from the air outlet 52 and the pattern hole 59 without being depressurized. Since the ejected air is under high pressure, it can be suitably used as duster air, and can also be used as air for applying high-viscosity paints. Therefore, the painting spray gun 1 of the present invention can be used in combination with a duster, improving its usability and versatility, and making it possible to downsize equipment and reduce costs. In addition, it can be used as a spray gun for painting high-viscosity paints, further increasing its versatility.In addition, the gun body 13 is equipped with a constriction part 11 to reduce the pressure of high-pressure air, so it can be used as a spray gun for painting high-viscosity paints. can also be abolished.

FIG. 3 shows another embodiment of the branch flow path 7 and the second on-off valve 9.

In this example, the branch flow path 7 is provided concentrically with the oblique hole 49, and communicates between the base hole portion 45A and the lower part of the control valve 43 of the upright hole 46 at both ends thereof. Further, a second opening/closing valve 9 of a Kotuku type is disposed in the branch channel 7, which opens and closes the branch channel 7 by rotating the branch channel 7.

In this example, the control valve 43 is used as the throttle part 11, and the pressure reduction rate of the high-pressure air can be arbitrarily adjusted by screwing the control valve 43 forward and backward.

In addition, as the aperture part 11, as shown in FIG.
It is also preferable to form the cap 65 of the horizontal hole 45 so that it can move forward and backward, and change the opening area of the intersection of the upright hole 46 and the horizontal hole 45 by moving it forward and backward.

〔Effect of the invention〕

As described above, the painting spray gun of the present invention includes a first on-off valve that opens and closes the upper air flow path and the lower air flow path, and a first on-off valve that opens and closes the upper air flow path and the lower air flow path. In addition to providing a second on-off valve that opens and closes the branch flow path that bypasses the branch flow path, a constriction portion is provided in the parallel flow path that is bypassed by the branch flow path, so that two types of air, high pressure and low pressure, can be discharged. By operating the first on-off valve, it can be used as a normal painting spray gun, and by operating the second on-off valve, it can be used as a duster. Furthermore, by operating the first on-off valve and the second on-off valve, it can also be used as a spray gun for painting high viscosity paint, increasing its versatility. Furthermore, since the constriction section is provided, a pressure reducing machine can be eliminated, and many effects can be achieved, such as contributing to downsizing of equipment and cost reduction.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing one embodiment of the present invention, and FIG.
The figure is a cross-sectional view showing the second on-off valve, and FIG. 3 is a cross-sectional view showing an upper air flow path and another embodiment of the second on-off valve.
FIG. 4 is a partial sectional view showing another example of the aperture section. 3... Upper air flow path, 4... Air cap, 5...
...lower air flow path, 6...first on-off valve, 7...branch flow path, 9...second on-off valve, 10...combined passage portion,
11... Aperture section.

Claims (1)

[Claims] 1. A first on-off valve that connects and disconnects the upper air flow path leading to the high-pressure air source and the lower air flow path leading to the air cap by finger operation, and the upper air flow path and the lower air flow path have both ends connected to each other. A second on-off valve that opens and closes a branch flow path that includes the first on-off valve and bypasses the upper air flow path and the lower air flow path by being electrically connected to the upper air flow path and the lower air flow path is provided. A spray gun for painting, comprising a constriction part provided in a joint portion that is bypassed by the branch flow path.