JPH0434921Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) This invention is a painting system that automatically paints workpieces such as automobile bodies by passing them through a painting booth equipped with multiple painting guns using a workpiece conveyor. Regarding equipment.

(Prior Art) Conventionally, as shown in Fig. 1, a paint circulation pipe c is provided in which a pressure pump a feeds paint from a paint tank b under high pressure and returns it to the paint tank b. A coating apparatus is known in which branch pipes e branched from the circulation path c are connected to a coating gun d, and in this case, pressure reducing valves f are interposed in each branch pipe e, and the pressure-feeding is carried out by these pressure reducing valves f. High-pressure paint from pump a is reduced to a predetermined pressure and supplied to each painting gun d.

(Problem to be solved by the invention) In the conventional method described above, if the paint pressure is set to a value slightly higher than the required pressure of each painting gun d, it will not be possible to adequately respond to sudden changes in paint consumption, and each gun will d
Since the supply pressure of paint to the gas becomes stable, the paint has to be pumped at a relatively high pressure, which is sufficiently higher than the required pressure of each gun d, and the pressure pump a becomes larger and the paint circulation pipe C also becomes high pressure. There is a problem that the equipment cost increases as a whole because piping that can withstand it is required.

An object of the present invention is to provide a device that solves these problems.

(Means for Solving the Problems) In order to achieve the above object, the present invention uses a pressure-feeding coating device in which a workpiece is coated by passing it through a coating booth in which a plurality of coating guns are arranged using a workpiece conveyor. A paint circulation pipe is provided that uses a pump to send paint from a paint tank under low pressure and returns it to the paint tank. Branch pipes branched from the circulation pipe are connected to each painting gun, and one pipe is connected to each branch pipe. Plunger-type pressure boost pumps that suck in and discharge a predetermined amount of paint in a cycle are provided, and a pressure regulating valve and an electromagnetic on-off valve are provided in the operating circuit of each fluid actuator that drives the plunger of each boost pump. It is characterized by what it did.

(Function) The paint pumped at low pressure by the pressure pump is boosted to a predetermined pressure by each booster pump, and then supplied to each painting gun at the required pressure.

In this case, each pressure regulating valve is interposed in the operating circuit of each fluid actuator that drives the plunger of each boost pump, so each pressure regulating valve adjusts the supply pressure of the pressure fluid supplied to each fluid actuator. The paint discharge pressure of the boost pump can be easily adjusted.

In addition, although it is necessary to add a booster pump to each branch pipe, a small, inexpensive, low-pressure pressure pump is sufficient, and the paint circulation line can also be an inexpensive low-pressure pipe, so the overall equipment cost is reduced. can be reduced.

(Example) Referring to FIG. 2, 1 is a painting booth, 2 is a work conveyor, and the conveyor 2 is composed of a plurality of carts 2c pulled by a chain 2b on a pair of rails 2a, 2a. One workpiece A is placed on each trolley 2c for conveyance, and each side of the conveyor 2 in the booth 1 is equipped with a painting gun 3 attached to the operating end. A robot 4 and a coating machine 6 having a coating gun 5 attached to its tip are provided, and a workpiece A is passed through the coating booth 1 by the conveyor 2 to be coated.

Then, a paint circulation pipe 9 is provided which pumps the paint from the paint tank 8 by the pressure pump 7 at a pressure lower than the required pressure of each painting gun 3, 5 and returns it to the tank 8 again. A plunger-type pipe is connected to branch pipes 10 branched from the circulation pipe 9, and sucks and discharges a predetermined amount of paint sufficient to coat one workpiece A in one cycle into each branch pipe 10. A booster pump 11 is provided, and a pressure regulating valve 14 and an electromagnetic on-off valve 15 are provided in the operating circuit 13 of each fluid actuator 12 that drives the plunger 11a of each booster pump 11.

Each of the actuators 12 is as shown in FIG.
It is composed of a reciprocating air cylinder, and a plunger 11 is installed at the tip of a piston rod 12a of the cylinder.
a, and the air from the pressure fluid supply source 16 is alternately supplied to both pressure chambers 12c, 12c, which are partitioned by the piston 12b of the cylinder, by the electromagnetic on-off valve 15. The paint is discharged from the pump chamber 11b by the downward movement of the plunger 11a, and the plunger 1
The paint can be sucked into the pump chamber 11b by upward backward movement of the pump 1a.

In this case, each actuator 12 is constructed of a reciprocating air cylinder as shown in FIG. 4, and the piston 12b is operated by supplying air to the pressure chamber 12c of the air cylinder, thereby causing the plunger 11a to move downwardly. The upward movement of the plunger 11a may be performed by the supply pressure of the paint from the pressure pump 7, as shown in FIG. , each actuator 12 is constituted by a reciprocating hydraulic cylinder, and a plunger 11a serving as a piston is housed in the cylinder, and one side of the cylinder partitioned by the plunger 11a is a pressure chamber 12c, and the other side is a pump chamber 11b. The pressure chamber 12c may be supplied with pressure oil from a hydraulic pressure supply source 16'.

In FIG. 3, reference numeral 17 indicates a three-way valve installed downstream of the boost pump 11 in the branch pipe 10.
The paint discharged from the paint guns 3 and 5 is sprayed, and the excess paint is transferred to the return pipe 1 by switching the three-way valve 17.
8 to return to paint tank 8. Reference numeral 19 indicates a throttle valve installed in the return pipe 18.

Further, in the drawing, 20 indicates a back pressure valve installed in the paint circulation pipe 9, and 21, 21 indicates a check valve.

Next, in order to explain the operation of the embodiment, first the workpiece A is conveyed by the workpiece conveyor 2.
When the paint reaches a predetermined position in front of each of the painting guns 3 and 5 in the painting booth 1, each actuator 12 is activated to discharge paint from each boost pump 11 and spray the paint from each painting gun 3 and 5.

Next, the painted workpiece A passes through the predetermined position, and each booster pump 11 sucks paint until the next workpiece A is carried into the predetermined position, and discharges the paint when the workpiece A reaches the predetermined position.

This process is repeated in order to coat workpiece A continuously.

In this case, each branch pipe 10 has a booster pump 11
Because of the interposition, the paint pumped at low pressure by the pressure pump 7 can be increased to a predetermined pressure by each pump 11, and the paint can be stably supplied to each painting gun 3, 5 at the required pressure.

In addition, since the pressure regulating valves 14 are interposed in the operating circuits 13 of each fluid actuator 12 that drive the plungers 11a of each boost pump 11, the supply pressure of the pressure fluid supplied to each actuator 12 is controlled by each pressure regulating valve 14. By adjusting, the paint discharge pressure of each booster pump 11 can be easily adjusted.

(Effects of the invention) In this way, the present invention is configured so that the paint that is circulated at low pressure is boosted to a predetermined pressure by each booster pump and then supplied to each painting gun. It is possible to use small and low-pressure pipes, which reduces equipment costs as a whole.Also, the paint discharge pressure of each booster pump can be easily adjusted, and since the paint is circulated at low pressure, high-pressure This has the effect of preventing deterioration of paint when circulating it.

[Brief explanation of the drawing]

Figure 1 is a diagram of a conventional example, Figure 2 is a plan view of an example of the device of the present invention, Figure 3 is a diagram of the main part, and Figures 4 and 5 are diagrams of modified examples. be. 1...Painting booth, 2...Work conveyor, 3, 5...Painting gun, 7...Pressure pump, 8
...Paint tank, 9...Paint circulation pipe, 10...
Branch pipe, 11... Boost pump, 11a... Plunger, 12... Fluid actuator, 13... Fluid actuator operating circuit, 14... Pressure regulating valve, 15...
...Open/close valve.

Claims (1)

[Scope of utility model registration request] In a coating device in which a workpiece is coated by passing it through a coating booth with multiple coating guns arranged on a workpiece conveyor, a paint circulation pipe in which paint is fed under low pressure from a paint tank by a pressure pump and returned to the paint tank again. A branch pipe branched from the circulation pipe line is connected to each painting gun, and a plunger-type booster pump is interposed in each branch pipe to suck in and discharge a predetermined amount of paint in one cycle. . A coating apparatus characterized in that a pressure regulating valve and an electromagnetic opening/closing valve are respectively provided in the operating circuit of each fluid actuator that drives the plunger of each booster pump.