JPH0215575Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Technical Field) The present invention relates to a type of paint circulation device that completely circulates all paint up to the paint sprayer in order to avoid sedimentation due to paint stagnation.

(Prior art) In order to avoid sedimentation due to stagnation of paint, a device that completely circulates all the paint in the paint piping is normally used as shown in Figure 1. Paint is supplied to the paint applicator 5 through a plurality of feed pipes 2 branched from the paint supply port 1, while a portion of the supplied paint is collected into the return pipe 4 through the bypass pipe 3 branched from the supply port 51 of the paint machine 5, and the paint is collected into the return pipe 4. It is configured to be returned to the tank 6.

However, this type of circulation device was
As described in Publication No. 41141, the flow of paint in the return pipe 4 determined by the amount of inflow from the bypass pipe 3 is slow, so it tends to settle, and the paint flows from the return pipe 4 toward the paint tank 6. In order to circulate the water, the diameter of the pipe 4 must be made larger toward the discharge side to reduce the pressure, which poses a problem in that it is more expensive than a straight pipe.

(Purpose) The present invention was made in view of the above problem, and its purpose is to prevent the settling of paint in the return pipe, and to make this pipe a straight pipe. An object of the present invention is to provide an improved paint circulation device.

(Structure) Therefore, details of the present invention will be explained below based on illustrated embodiments.

FIG. 2 shows an embodiment of the present invention, in which the same parts as in the conventional device are given the same reference numerals.

The pressure feed pipe 11 supplies the paint in the paint tank 6 to each painting device 5 in the painting workshop via the paint pressure pump 11 and the filter 12, and the pressure feed pipe return side pipe 1
3 and returns to the paint tank 6.The paint feed pipe 2, which branches from a part of the pressure feed pipe 1, is connected to an intermediate filter as shown in an enlarged view in FIG. 21, the paint is supplied to a connecting joint 23 via a paint pressure regulating regulator 22, and the paint is injected from a paint device 5, ie, a spray gun, connected thereto.

On the other hand, the return pipe 4, which is entirely composed of straight pipes with the same diameter, runs from the connection joint 23 to the needle valve 3.
1. It is connected to the bypass pipe 3 extending through the check valve 32, and a part of the paint in the paint supply pipe 2 that has flowed through the pipe 3 is collected and returned to the paint tank 6. However, the most upstream part 41 of the return pipe 4 is connected to a three-way valve 14 disposed in the middle of the return pipe 13 of the pressure-feeding pipe.
The control device 15 is configured to receive the pressurized paint flowing through the return side pipe line 13 of the pressurized pipe by a control device 15 that switches the pressure intermittently. In addition, the reference numeral 16 in the figure
1 shows a back pressure regulator disposed in a part of the pressure-feeding pipe return line 13.

In the above-mentioned device, the paint pumped from the paint tank 6 by the pressure pump 11 goes around the pressure pipe 1 and returns to the paint tank 6 via the pressure pipe return pipe 13, but some of the paint is branched by the pressure pipe 1. The paint enters the feed pipe 2 and is sprayed from the paint device 5 onto the surface to be painted, and a part of the paint in the paint feed pipe 2 flows into the return pipe 4 from the bypass pipe 3, and the spraying is stopped. At the same time, the paint is prevented from settling in the paint feed pipe 2.

By the way, when paint sequentially flows into the return pipe 4, which is made up of straight pipes with the same diameter, from the bypass pipe 3 during which spraying is suspended, the flow velocity of the paint decreases significantly on the downstream side, making it easier to settle. , control device 1
5, the three-way valve 14 is activated every 1 to 3 hours, for example.
When the return pipe 4 is connected to the return pipe line 13 of the pressure-feeding pipe, the paint pumped by the pressure-feeding pump 11 flows into the return pipe 4, and the paint in the pipe 4 is forced into the paint tank. 6, and sedimentation of the paint within the tube is completely prevented. Note that this switching time is set to about 5 to 20 minutes, and after this time has elapsed, the three-way valve 14 returns to its original state and resumes normal paint circulation.

(Effects) As described above, according to the present invention, the upstream side of the return pipe that collects paint from the bypass pipe and circulates it back to the paint supply source is a three-way pipe arranged in the return pipe of the pressure-feeding pipe. Even if an inexpensive straight pipe is used for the return piping, the paint inside can be forcibly fed by the pressure on the return pressure piping side, completely preventing the paint from settling inside the piping. be able to.
Moreover, since the three-way valve is operated intermittently, it is not only possible to prevent the paint from settling in the return piping periodically, but also to prevent the paint from settling in the return piping without having to install a regulator to create a differential pressure in each piping. Under normal operating conditions, normal paint circulation can be achieved, and the apparatus can be constructed at low cost.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing an example of a conventional device;
The figure is a schematic configuration diagram of an apparatus showing an embodiment of the present invention, and FIG. 3 is a configuration diagram of a paint supply pipe system in the same apparatus. DESCRIPTION OF SYMBOLS 1... Pressure feeding piping, 13... Pressure feeding piping return side pipe, 14... Three-way valve, 15... Control device, 2...
Paint supply pipe, 3... Bypass pipe, 4... Return piping, 5... Painter, 6... Paint tank.

Claims (1)

[Scope of utility model registration request] A pressure feed pipe that constitutes a circulation flow path, a plurality of feed pipes that branch from the pressure feed pipe and feed the pressurized paint to the paint applicator, and paint that is fed from the supply port of the paint device to the return pipe. In a paint circulation system equipped with a bypass pipe through which a part of the paint flows, and a return pipe which collects the paint from the bypass pipe and returns it to the paint supply source, an intermittently A paint circulation device characterized in that a three-way valve for switching flow paths is provided, and an upstream end of the return pipe is connected to the three-way valve.