JPS6045945B2 - Paint color changing device - Google Patents

Description

[Detailed description of the invention] The present invention relates to a paint replacement device.

Conventionally, by using a constant volume gear pump to supply paint to a coating machine, it has become possible to control film thickness at an extremely high level with automatic painting. This is because gear pumps can stably supply paint without fluctuations in the discharge amount regardless of the viscosity, specific gravity, or magnitude of the discharge amount, and can easily finely adjust the discharge amount.

However, if the discharge outlet is closed while the gear pump is in operation, the pressure in the system will instantly rise abnormally, damaging the gear pump and hose.
To avoid applying abnormally high pressure to the gear pump, either open and close the valve alternately to continue discharging to the sprayer, or stop discharging and return the discharge to the suction side of the pump for circulation. used.

Therefore, when relocating using a large number of gear pumps, the number of two-way valves increases multiple times according to the number of colors, making the structure and operation control complex, and requiring a lot of time for relocating.

The present invention has been made in view of the problems in the prior art described above, and uses a Ξ-way valve instead of a two-way valve.

It is an object of the present invention to provide a paint replacement device that can be made compact, have a simple structure, and provide a stable supply of paint. For this reason, the configuration of the present invention operates the piston by introducing and discharging fluid at a predetermined pressure, and the valve body installed integrally with the piston operates the piston.
A circulation path that connects a paint inlet and a paint outlet and circulates paint pumped by a constant volume pump, or connects a paint inlet and a paint discharge port to supply paint from the constant volume pump. A plurality of three-way valves that always form one of the paint supply paths are arranged close to a valve holder that forms a paint supply path that communicates with the paint sprayer via a paint hose. In addition, the present invention is characterized in that the paint discharge port of each three-way valve faces the paint supply passage in close proximity to the paint supply passage.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of a paint color changing device according to the present invention. In this embodiment, six three-way valves are arranged facing each other in parallel.

A paint passage 2 is formed in the lower part of the valve device main body 1, and a paint inlet 2a, a paint outlet 2b, and a paint discharge port 2c are opened at the ends of the paint passage 2. Paint inlet 2a in paint passage 2
A first valve seat 3 is formed between the paint outlet 2b and the paint outlet 2b, and a second valve seat 4 is formed at the open end of the paint outlet 2c. Paint passage 2 between first valve seat part 3 and second valve seat part 4
A valve body 5 is located inside, and the valve body 5 is connected via a connecting rod 6 to
It is connected to the piston 7. 8 is a lock nut.

The piston 7 is located in a cylinder 9 formed in the upper part of the valve device main body 1, and is constantly urged downward by the elastic force of the compression coil spring 10. An air flow passage 11 through which air as a fluid passes is formed so as to surround a cylinder 9 formed inside the valve device main body 1, and the air flow passage 11 communicates with the inside of the cylinder 9 on the lower surface of the cylinder 9. The other end has an air inlet 11a. On the outer peripheral surface of the piston 7, a ring 7. a and 7a are fitted and installed to improve the sealing performance between the piston 7 and the cylinder 9. Further, 13 is a sealing member for the connecting rod 6, 14 is a guide for the connecting rod 6, and a compression coil spring 15 is interposed between the member 13 and the guide 14. The valve device main body 1 configured in this way has screws 51, 51 and 51 facing each other on a valve holder 50 for attaching the valve device main body.
..., and the valve holders 50, 50, 50 are fastened to each other by bolts 52, 52 and nuts 53, 53.

A paint supply passage 54 that communicates with each other is formed in the valve holders 50, 50, 50, and the second valve seat portions 4, 4, . . . of the valve device main bodies 1, 1, . Each of them is arranged in the immediate vicinity of the passage 54. A threaded portion 54a is formed at the other end of the paint supply passage 54, and one end of a paint hose for supplying paint to a coating machine (not shown) is screwed to the threaded portion 54a. When increasing the number of valve device bodies 1, the number of valve holders 50 may be increased as appropriate. Paint sent at a predetermined flow rate by a constant displacement gear pump flows into the paint passage 2 from the paint inlet 2a, but when the piston 7 is in the state shown in the first figure, the first valve seat 3 and the valve Since the body 5 is spaced apart, the paint that has flowed into the paint passage 2 is discharged from the paint outlet 2b. However, when air at a predetermined pressure is sent into the air flow passage 11 from the air introduction port 11a, The piston 7 rises by overcoming the elastic force of the compression coil spring 10, and the valve body 5 comes into pressure contact with the first valve seat part 3 and separates from the second valve seat part 4.

As a result, the paint that has flowed in from the paint inlet 2a flows out from the paint discharge port 2c. That is, switching of the flow path of the paint passage 2 is performed by sucking control air that is forced into the air flow passage 11. Since it is provided close to the table, the paint supply passage can be formed short, and the time required for cleaning can be shortened.

Further, when the three-way valve is disposed on the valve holder, the paint discharge port is disposed immediately adjacent to the paint supply passage, so that the volume of the recessed portion occupied by the paint supply passage is minimized.

FIG. 2 shows a paint color changing device for changing three colors, and in this embodiment, four of the three-way valves described above are used.

Three-way valves 1a, 1b, 1c, and 1'' are mounted parallel to and opposite to the valve pedestal 16, and 1'' closes the paint outlet of the three-way valve. That is, it functions as a two-way valve. 1'' is placed at the rear of the system leading to the coating machine to ensure and facilitate cleaning.The paint outlet 2 is located in the paint supply passage (not shown) formed in the valve holder 16.
c is open.

One end of the paint supply passage is connected to an electrostatic coating machine 17. In the figure, 18 indicates a constant displacement gear pump, 19 indicates a paint tank for paint A, 20 indicates a paint tank for paint B, and 21 indicates a paint tank for paint C. 22
is the circulation of cleaning thinner, and 23 is the regulator.

Preparation for painting is completed with the gear pumps 18, 18, 18 in operation, but at this time, paints A, B,
C flows into the paint passage 2 from the paint inlet 2a of the three-way valves 1a, 1b, 1c, and is discharged from the paint outlet 2b to return to the original paint tanks 19, 20, 21, respectively.

Now, when painting the object to be coated using paint A, control air is supplied from the air inlet 11a of the three-way valve 1a to operate the piston 7, and the paint passage 2 of the three-way valve 1a is
The paint A supplied inside the valve holder 1 is transferred from the paint outlet 2c to the valve holder 1.
The paint is supplied into the paint supply passage No.6. Then, the paint A is applied to the object to be coated by the electrostatic coating machine 17. When switching the paint from A to B, the supply of control air from the three-way valve 1a is stopped and the paint discharge port 2c leading to the paint sprayer 17 is opened.
By closing the paint A, the paint A is circulated from the paint outlet 2b through the tank 19.

Control air is supplied to the valve 1'' with the paint outlet 2b of the three-way valve closed. Then, cleaning thinner is supplied from the wrinkler circulation 22 to the paint outlet 2 of the valve 1''.
The paint is supplied into the paint supply passage of the valve holder 16 through the valve holder 16, and the inside of the paint supply passage, the inside of the paint hose 24, and the inside passage of the electrostatic atomizer 17 are cleaned. Here, if the supply of control air to the valve ``is stopped and control air is supplied to the three-way valve 1b, the paint B will be transferred to the electrostatic coating machine 1.
It will be sent to 7. Thereafter, by repeating the above operations, the colors are changed as appropriate. The control air can be switched manually or automatically, and the coating machine 17 is not limited to an electrostatic coating machine.

If the discharge of paint is interrupted during painting, sedimentation may occur and the desired finish may not be achieved. Therefore, during painting, it is better to keep the gear pump for unused paint running at all times to circulate the paint. desirable.

This circulation is even more necessary when using paints containing metals, which are particularly prone to sedimentation, and in this case, a three-way valve color changing device is extremely easy to operate and effective. be. As explained above, according to the present invention, since a three-way valve that switches the valve using fluid pressure is installed in the coating device, the circulation and discharge of paint are stable and reliable. The paint color can be changed accurately, and since multiple three-way valves are disposed close to each other in a valve holder that has a paint supply passage inside, the device can be made more compact, the structure can be simplified, and cleaning can be achieved. The cleaning time has been shortened by shortening the system for cleaning, and furthermore, since the paint discharge port of the three-way valve faces the paint supply passage in the valve pedestal, the paint supply passage near the paint discharge port It is possible to provide a paint color changing device that exhibits many effects such as less color buildup in recesses and the ability to reliably remove color buildup with short-time thinner cleaning.

Furthermore, if the same three-way valve according to the present invention is used as the cleaning thinner valve as in this embodiment, furthermore,
Not only can this device be made more compact and have a simpler structure, but the three-way valve can be mass-produced, which can also contribute to reducing the cost of the three-way valve.

Furthermore, this three-way valve can also be used for air supply.

[Brief explanation of the drawing]

FIG. 1A shows a sectional view of an apparatus according to an embodiment of the present invention, a top view of FIG. DESCRIPTION OF SYMBOLS 1...Valve device main body, 2...Paint passage, 2a...Paint inlet, 2b...Paint outlet, 2c...Paint discharge port,
3...21st valve seat part, 4...2nd valve seat part, 5...
Valve body, 6...Connecting rod, 7...Zeston, 9...Cylinder, 10...Compression coil spring, 11...Air flow path, 11a...Air inlet 1a, 1b, 1c,
1″...Three-way valve, 16,50...Valve holder, 17...
・Electrostatic coating machine, 18...Gear pump, 19,20,
21...Paint tank, 22...Thinner circulation, 23...Regulator, 24...Paint hose, 54...Paint supply passage.

Claims (1)

[Claims] 1 The piston is operated by introducing and discharging liquid at a predetermined pressure, and the valve body attached integrally with the piston is brought into contact with one valve seat, thereby connecting the paint inlet and the paint outlet. , a circulation path for circulating the paint pumped by the constant volume pump, and a circulation path for connecting the paint inlet and the paint outlet by bringing the valve body into contact with the other valve seat, and the constant volume pump A three-way valve formed by forming either one of the paint supply routes for supplying paint from the paint supply route, and a paint supply route communicating with the paint sprayer via the paint hose formed inside the valve holder; A paint color changing device characterized in that a plurality of three-way valves are disposed close to each other, and the paint discharge port of each three-way valve faces the paint supply path in the immediate vicinity of the paint supply path.