JPS593225B2 - automatic spray gun - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a general automatic spray gun or an automatic spray gun for electrostatic painting in which the amount of paint ejected can be digitally controlled in conjunction with automation of painting.

Currently, with the automation of painting, humans are no longer required to operate spray guns, and robots are now performing these functions.

However, there was no way to digitally control the amount of paint ejected. The present invention was made in view of the above circumstances.

In other words, the control function for automatic painting is the O of the spray gun.
There are N-OFF, position, angle and movement speed of the spray gun, etc., but when examining the operation of a handgun operated by a human, it is found that in addition to the above functions, there are times when the needle valve is unknowingly messed up. However, it can be seen that the amount of paint sprayed is adjusted.Of course, in order to perform more advanced and effective painting, strictly speaking, automatic guns also need this function, and the present invention The method attempts to digitally control the ejection amount of paint at several preset levels.

Hereinafter, the present invention will be explained with reference to drawings of embodiments.

First, the concrete structure for controlling the spray gun consists of an electric control system 1, an air control system 2, and a gun needle valve operating system 3, as shown in FIG.

Generally, when the paint pressure is constant, the amount of paint ejected is changed by the degree of opening of the needle valve. Therefore,
By controlling the first generation of the needle valve, the amount of paint ejected can be controlled, but this is normal! 5. In the form and shape of the nozzle needle, 1 of the needle valve that changes the jetting amount.
It is known that the ejection amount is in the range of 0 to 2 mm, and even if the ejection amount exceeds 2 mm, the ejection amount remains unchanged and does not increase significantly. In the case of an automatic gun, the function of pulling the needle valve is generally to move the piston from 10 to increase the pressure of working air, and then pull the needle valve accordingly.In this case, the change in air pressure causes the needle valve to move. It is possible to change a generation.
Theoretically, by knowing the spring constant, friction coefficient, and paint 95 pressure of the spring that pushes the piston back when there is no working air, and strictly controlling the working air pressure, it is possible to change the needle valve's generation in an analog way. I can do it. However, in reality, due to changes over time in each factor, changes in spring set state, fluctuations in paint pressure, difficulty in finely controlling air pressure, etc., it is necessary to set the delivery allowance to a predetermined value within the range of 0 to 2 degrees. Difficult to control.

The needle valve operating system of the present invention provides a stable displacement even when the above factors change, and allows the displacement of the needle valve to be digitally drawn at the set position of the piston receiving plate. .

In other words, the relationship between the air blowing pressure and the moving amount is shown in FIG. 2.

Here, the values of the working air pressures Pal, pa2, and pa3 can be appropriately selected by changing the spring constant of the spring that presses the piston and the piston receiving plate, and the piston travel distance 1
1, 12, and 13 can also be set appropriately depending on the setting position of the piston receiving plate. Next, the automatic spray gun 4 in which the amount of paint ejected can be adjusted in stages will be explained based on the operating air control circuit 5 of the embodiment.

First, in this automatic spray gun 4, a needle valve 6 penetrates through the center of the gun body 4', a piston 7 is fitted into the rear end of the needle valve 6, and the tip is capped on the back side of the piston 7. It is equipped with springs 9, 9', g', which are engaged with springs 8 and which restrict the backward movement in stages, and the springs 9, 9', r are set in a flexed state so as to have an initial load.

In this case, the two springs 9', 9'' are attached to the fixed guide 10.
The piston 7 is moved in three stages as a whole with the piston receiving plate 11, 1V whose position is regulated by the stepped part, and the tip of the needle valve 6 is connected to the paint spout 12a of the paint nozzle 12. When I came to the meeting, it became applicable. An air cap 13 is arranged in front of the paint nozzle 12. Also, the air control circuit 5
Three-way solenoid valves 15, 152, 152 are connected in parallel via pressure reducing valves 14, 14', 14'' with relief, respectively, and a shuttle valve 16 is connected to the discharge port of the solenoid valves 15, 15', A shuttle valve 16' is connected between the shuttle valve 16 and the remaining solenoid valve 15'', and the discharge port of the shuttle valve 16' is guided to the air passage 17 facing the piston 7 of the gun body 4' to form an 0R circuit. It will be configured. Reference numeral 18 indicates an air passage for pattern adjustment, and the tip of the air passage 18 communicates with the air cap 13.

Next, to explain the operation of the present invention, first, when obtaining the first stage paint ejection amount, if the electric signal A is applied to the air control circuit 5, the electromagnetic valve 15 corresponding to the first stage paint ejection amount is activated. The solenoid 15a is energized to open the valve, and this air pressure passes through the shuttle valves 16 and 16', which serve as 0R elements, to the piston 7.
The spring 9 corresponding to this air pressure is pressed to move the needle valve 6 by a distance of 11, and the needle valve 6 is engaged with the piston 7.
moves backward by a predetermined amount, and the tip of the needle valve 6 presents a certain opening to the paint spout 12a of the paint nozzle 12, and paint flows in from the paint passage 19 and the first stage jet amount is discharged. become something that When it is desired to obtain the ejection amount of the second or third stage, a different electric signal A is applied to the air control circuit 5 to operate the solenoid valve 15' or 15'', and the piston 7
is moved back 12 or 13 distances, and the needle valve 6 is interlocked to obtain the second or third stage ejection amount.

That is, for the piston retraction distance 11, an air pressure between Pa2 and Pal is applied, for the retraction distance 12, an air pressure between Pa3-4)A2 is applied, and for the retraction distance 13, an air pressure of Pa3 or more is applied. As mentioned above, the automatic spray gun of the present invention is provided with a plurality of piston receiving plates in stages on the back of the piston provided at the rear end of the needle valve, and which regulates the retracted position of the piston. By disposing a spring set in a flexed state at the rear of the receiving plate, the retracted position of the piston can be regulated in stages by controlling the operating air pressure supplied to the piston.In other words, the retracted position of the needle valve can be regulated in stages. Since it is possible to accurately control the amount of paint ejected, it is possible to accurately adjust the amount of paint ejected.

Furthermore, the present invention makes it possible to digitally control the amount of paint ejected by applying sequence control to the electromagnetic valve actuation signal of the air control system, thereby making it possible to remotely control the automatic spray gun.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; Fig. 1 is a flow sheet diagram showing the automatic adjustment system, Fig. 2 is an explanatory diagram showing the amount of movement of the piston part that operates the needle valve, and Fig. 3 is the air control system. The circuit diagram, FIG. 4, is a sectional view of the gun body. 1... Electric control system, 2... Air control system, 3... Gun needle valve operation system, 4...
Hakudo spray gun, 41...Same gun body, 6...
...Needle valve, 7...Piston, 9,9
',9''... Spring, 11,11'...
...Piston receiving plate, 17...Air passage.

Claims (1)

[Scope of Claims] 1. In an air spray gun in which a needle valve is retracted by the operation of a piston to change the amount of paint ejected, a plurality of piston receiving plates for regulating the retracted position of the piston are provided in stages at the rear of the piston. , a spring is arranged at the rear of each piston receiving plate, and by selecting the working air pressure supplied to the piston, the retracted position of the piston is regulated in stages, and the amount of paint ejected can be adjusted in stages. automatic spray gun. 2. Claim 1, wherein the spring is attached to the rear part of the piston receiving plate in a deflected state so as to have an initial load.
Automatic spray gun as described in section.