JPH0344283Y2 - - Google Patents

Description

[Detailed explanation of the idea] Industrial applications The present invention relates to a paint supply device for a paint gun.

BACKGROUND OF THE INVENTION Hand-sprayed paint guns have traditionally been used to paint automobile bodies and the like. As shown in FIG. 2, this paint supply device for a hand-spraying gun usually includes a throttle valve 11 for controlling the discharge amount in a paint circulation pipe 10, and a branch pipe 12 is connected from the paint circulation pipe 10 downstream of the throttle valve 11. This branch pipe 12 is branched and connected to a hand-blown coating gun 13, and a manual three-way switching valve 14 is disposed at the branch part of the branch pipe 12. As is well known, paint is a mixture of pigments dissolved in a solvent.
Therefore, if the flow of the paint in the paint circulation pipe 10 is stopped for a while, a problem arises in that the pigment in the paint settles. Therefore, in conventional paint supply devices, when painting is to be done, the three-way switching valve 14 is manually switched to send paint from the paint circulation pipe 10 into the branch pipe 12, and when the painting work is completed, the three-way switching valve 14 is manually switched again. The paint is switched to circulate within the paint circulation pipe 10. Also, in many paint guns, a paint supply hose for supplying paint to the paint gun and a paint return hose for returning paint supplied to the paint gun are connected to the paint gun, but in reality, these hoses are connected to the paint gun. The weight of the hose is quite heavy, and therefore, when two hoses are connected to the painting gun in this way, there is a problem in that the painting gun is quite difficult to operate. Therefore, in the conventional paint supply device, as shown in FIG. 2, a paint return hose is not provided to the paint gun, but only a paint supply hose is provided.

Problems to be Solved by the Invention However, as mentioned above, with the conventional paint supply device, the three-way switching valve 14 must be manually switched each time the painting operation is started and completed, which only makes the painting operation more complicated. If you forget to switch the three-way switching valve 14 when painting is completed, the paint circulation piping 10
A problem arises in that the pigment in the paint settles because the flow of the paint in the paint stops.

Means for Solving the Problems According to the present invention, in order to solve the above problems,
In a paint supply device that has a paint supply hose for supplying paint to a paint gun but does not have a paint return hose for returning paint supplied to the paint gun, a discharge rate control throttle valve is installed in the paint circulation piping. A branch pipe is branched from the paint circulation pipe downstream of the throttle valve, and the branch pipe is connected to the paint gun via the paint supply hose. When the paint gun stops operating, the valve is automatically opened by the paint pressure and the paint is painted. A check valve that automatically closes when the gun is activated and the paint pressure in the paint circulation pipe falls below a predetermined pressure is installed in the paint circulation pipe downstream of the branch of the branch pipe. .

Embodiment Referring to FIG. 1, reference numeral 1 indicates a paint circulation pipe, and reference numeral 2 indicates a manual throttle valve for controlling the discharge amount installed in the paint circulation pipe 1. The paint is pumped through the paint circulation pipe 1 in the direction of the arrow by a circulation pump (not shown). A branch pipe 3 is branched from the paint circulation pipe 1 downstream of the throttle valve 2, and a hand-sprayed paint gun 4 is connected to this branch pipe 3 via a paint supply hose 5. A check valve 7 is inserted into the paint circulation pipe 1 downstream of the branch portion 6 of the branch pipe 3 and allows the paint to flow only in the circulation direction. This check valve 7 is schematically shown in FIG. 1 as a ball and a compression spring, but it may be of any type. This check valve 7 opens when the pressure difference between the upstream side and the downstream side of the check valve 7 exceeds a predetermined constant pressure.

When painting work is not being performed, paint is supplied into the paint circulation pipe 1 at a predetermined pressure.
At this time, the check valve 7 is opened, so that the paint is circulated through the paint circulation pipe 1 through the check valve 7. On the other hand, when the hand-spraying gun 4 is activated, the paint pressure in the branch pipe 3 decreases, so the check valve 7
The paint pressure on the upstream side also decreases, and the check valve 7 automatically closes at this time. Therefore, at this time, the paint is supplied from the paint circulation pipe 1 via the branch pipe 3 to the hand-spraying gun 4, and is ejected from the hand-spraying gun 4. At this time, since the check valve 7 is closed as described above, the amount of paint discharged from the hand spray gun 4 can be accurately adjusted by operating the throttle valve 2. On the other hand, when the painting operation is completed and the spraying of paint from the hand-spraying gun 4 is stopped, the pressure in the paint circulation pipe 1 upstream of the check valve 7 rises again, and the check valve 7 closes. The valve is automatically opened and the paint is circulated through the paint circulation pipe 1.

Effects of the invention During painting work, paint is automatically supplied to the paint gun, and when painting work is completed, paint is automatically circulated through the paint circulation piping. Therefore, since there is no need to switch the three-way switching valve each time as in the conventional case, the painting work is simplified and the time required for the painting work is also shortened. Furthermore, since the flow of paint in the paint circulation pipe does not stop after the painting work is completed, there is no risk of pigments in the paint settling. Furthermore, since the check valve closes during painting operations, the amount of paint discharged from the painting gun can be accurately adjusted by operating the throttle valve.

[Brief explanation of the drawing]

Figure 1 is an overall view of the paint supply device according to the present invention.
FIG. 2 is an overall view of a paint supply device currently in use. 1... Paint circulation piping, 2... Throttle valve, 3... Branch pipe, 4... Paint gun, 5... Paint supply hose,
6... Branch, 7... Check valve.

Claims (1)

[Scope of utility model registration request] In a paint supply device that has a paint supply hose for supplying paint to a paint gun but does not have a paint return hose for returning paint supplied to a paint gun, a throttle valve for controlling the discharge amount is installed in the paint circulation piping. A branch pipe is branched from the paint circulation pipe downstream of the throttle valve, and the branch pipe is connected to the paint gun via the paint supply hose, and the valve is automatically opened by the paint pressure when the paint gun stops operating. In addition, a check valve that automatically closes when the paint gun is activated and the paint pressure in the paint circulation pipe falls below a predetermined pressure is installed in the paint circulation pipe downstream of the branch part of the branch pipe. A paint supply device for a painting gun installed in