JP2530531B2 - Internal mixed spray gun - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal mixing type coating spray gun which is mainly used for spraying paint on the inner and outer wall surfaces of buildings and ceiling surfaces.

[0002]

2. Description of the Related Art As shown in FIG. 3, a conventional internal mixing type coating spray gun of this type has an air nozzle 3 whose tip is on the same rear axis of a paint nozzle 2 mounted on a spray gun main body 1. The rear end of the paint nozzle is a high-pressure air guide tube 4, and the paint supplied between the nozzles 2 and 3 is supplied to the paint nozzle 2 by the high-pressure air jetted from the air nozzle 3.
It is designed to jet from.

[0003]

However, in the internal mixing type coating spray gun of the above-mentioned conventional structure, high-pressure air is jetted from the air nozzle 3 at the time of spraying work. Backflow is avoided, but when the spraying work is stopped, paint and the like flow backwards from the air nozzle into the high-pressure air guide tube and become clogged.Therefore, the spraying work is often interrupted and the wire or needle-shaped bar is applied from the paint nozzle side. There is a problem to be solved in that it requires a troublesome extra work such as inserting a needle or a needle-shaped rod into the high-pressure air guide tube to clear the clogging, and significantly lowering the coating work efficiency. .

SUMMARY OF THE INVENTION It is an object of the present invention to provide an internal mixing type coating spray gun which prevents clogging of paint by opening and closing an air nozzle according to the start and stop of a spraying work and has a high coating work efficiency. I am trying.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides an internal mixing type spray gun for spraying an internal mixing type spray gun on the same rear axis of a paint nozzle mainly mounted on the spray gun and at an end thereof. An interior having a single or multiple heads, in which a high-pressure air guide tube is provided and the paint supplied to the paint chamber between both nozzles is sprayed from the paint nozzle by high-pressure air sprayed from the air nozzle. In the mixed spray gun for painting, a needle valve is provided in the high-pressure air guide tube so as to move backward when the high-pressure air is jetted and move forward into the air nozzle at the tip when the jetting is stopped.

[0006]

As described above, by equipping the high-pressure air guide tube with a needle valve that moves backward when the high-pressure air is jetted and moves forward into the air nozzle at the tip when the jetting is stopped, at the same time when the painting operation is stopped, Since the air nozzle is blocked by the needle valve, it is possible to prevent backflow of paint etc. from the air nozzle to the inside.
The clogging release work, which was frequently required every time the spraying work is stopped or periodically, becomes unnecessary, and it works to remarkably improve the spraying work efficiency of the paint.

[0007]

EXAMPLES The construction of an internal mixing type spray gun for coating (hereinafter referred to as a coating spray gun) according to the present invention will be described based on examples. FIG. 1 is a schematic configuration diagram of a coating spray gun according to a first embodiment of the present invention. A high-pressure air guide tube 4 provided with an air nozzle 3 is provided, and a paint chamber 6 between both nozzles is provided.
A spray gun for painting, in which the paint supplied to the above is jetted from the paint nozzle 2 by the high-pressure air jetted from the air nozzle 3, and a needle valve 7 is installed in the high-pressure air guide pipe 4. When the high pressure air is injected, the needle valve 7 acts on the piston 10 housed in the cylinder 9 in which the high pressure air is integrated with the needle valve 7 and the ventilation port 8 is opened, so that the ventilation port 8 side in the cylinder 9 side. It is configured to retreat against the spring 11 arranged in the above, and to be advanced by the spring 11 when the injection of high pressure air is stopped.

In the coating spray gun constructed as described above, the high pressure air guide tube 4 is used to inject the paint supplied to the paint chamber 6 from the paint nozzle 2 by the high pressure air injected from the air nozzle 3. When high pressure air is supplied to the piston 10, the air pressure acts on the piston 10 to move it against the spring 11, thereby causing the needle valve 7 that has closed the air nozzle 3 to retreat and open, and also to spray the air. When the supply of high-pressure air is stopped to stop the work, the air pressure does not act on the piston 10, and the elastic force of the spring 11 acts in the opposite direction to move the needle valve 7 forward to close the air nozzle 3. That is, it works to prevent backflow of paint or the like from the air nozzle 3.

FIG. 2 is a schematic view of the coating spray gun according to the second embodiment, which is the same as the first embodiment except that the advancing and retracting means of the needle valve 7 is different. The same reference numerals are given and the description is omitted, and only the forward / backward configuration will be described. The structure is to move the piston 10 housed in the cylinder 9 integrally with the needle valve 7 by switching the high pressure air, and to guide the high pressure air to the one air chamber 12 partitioned by the piston 10. When air pressure acts from the inside of the pipe 4, the other air chamber 13 of the cylinder 9 is communicated with the atmosphere, and conversely, the other air chamber 13
When high pressure air is applied from the one air chamber 12
The switching valve 14 that is switched to communicate with the atmosphere is installed in the high-pressure air supply path.

Also in the coating spray gun of the second embodiment constructed as described above, the spraying work is stopped and the needle valve 7 is advanced and retracted at the start of the spraying work as in the case of the first embodiment, so that the paint etc. when the work is stopped It functions to prevent backflow from the air nozzle 3.

[0011]

As described above, in the internal mixing type coating spray gun of the present invention, when the high pressure air is injected into the high pressure air guide tube, it is retracted, and when the injection is stopped, it is advanced into the air nozzle at the tip. Since the needle valve is provided, the air nozzle is blocked by the needle valve at the same time when the painting operation is stopped, and the backflow of the paint and the like from the air nozzle to the inside is prevented. Therefore, the troublesome work of clearing the clogging, which is required every time the spraying work is stopped, becomes unnecessary, and there is an effect that the spraying work efficiency of the paint is remarkably improved.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a spray gun for internal mixing type coating according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram of the internal mixing type coating spray gun according to the second embodiment of the present invention.

FIG. 3 is a schematic diagram of a conventional spray gun for internal mixing type coating.

[Explanation of symbols] 1 Spray gun main body 2 Paint nozzle 3 Air nozzle 4 High pressure air guide tube 5 Paint hopper 6 Paint chamber 7 Needle valve 8 Vent port 9 Cylinder 10 Piston 11 Spring 12 One air chamber 13 The other air chamber 14 Switching valve

Claims (3)

(57) [Claims] 1. A high-pressure air guide tube having an air nozzle at its tip is arranged on the same rear axis of a paint nozzle mounted on a spray gun as a main body, and paint supplied to a paint chamber between the nozzles is provided. In an internal mixing type coating spray gun having a single head or a plurality of heads, which is adapted to be sprayed from a paint nozzle by high-pressure air sprayed from an air nozzle, in the high-pressure air guide tube, when the high-pressure air is jetted, it is retracted and when the jetting is stopped. An internal mixing type spray gun for painting, which is equipped with a needle valve that moves forward into the air nozzle at the tip. 2. The advancing / retreating means of the needle valve causes the high-pressure air, together with the needle valve, to act on the piston housed in the cylinder when the high-pressure air is jetted, and retreat against the spring to relieve the high-pressure air. The spray gun for internal mixing type coating according to claim 1, wherein the spray gun is moved forward by the spring when the injection is stopped. 3. The needle valve advancing / retreating means is configured to advance / retreat a piston housed in the cylinder integrally with the needle valve by switching high pressure air.
Internal mixing type coating spray gun described.