JP2556811B2 - Spray gun for electrostatic coating - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is designed to apply a high voltage between the tip of a spray gun and an object to be coated so that the fine particle paint ejected from the spray gun by the action of an electrostatic field is attracted to the object to be coated. Regarding the spray gun for electrostatic coating,
The present invention relates to a spray gun for electrostatic coating that prevents electricity from leaking from the tip of the gun body through the gun body.

[0002]

2. Description of the Related Art In a conventional electrostatic coating spray gun, a valve rod that opens and closes a valve opening formed in a paint passage is connected to a piston of an air cylinder by a rod that passes through the inside of the gun body to open and close the valve opening. It was becoming.

Therefore, the moisture in the compressed air carried into the air cylinder reaches the tip of the gun body from the rod and the valve rod through the seal portion, and the high potential electricity applied to this portion is the moisture. As a result, it is transmitted to the rear part of the gun body, leaks to the ground, and the potential drops, which prevents normal electrostatic coating.

[0004]

The problem to be solved by the present invention is to prevent the high voltage from leaking due to the moisture in the air cylinder being transmitted to the tip of the gun body.

[0005]

As a means for solving the above-mentioned problems, the present invention provides a valve rod provided in a paint passage formed in a gun body, and a valve rod which is opened / closed to / from the valve port is connected via a rod. In the spray gun for electrostatic coating connected to the piston of the air cylinder, a part of the gun body was cut off to expose the rod.

[0006]

The present invention has the above-described structure. Since the rod is exposed by cutting off a part of the gun body, even if moisture leaking from the air cylinder is transmitted to the rod, it is evaporated in the exposed portion. Therefore, it is possible to prevent the high voltage from leaking to the tip portion of the gun body and to prevent the high voltage from leaking to the tip portion of the gun body, and to perform normal electrostatic coating.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings.

In the figure, reference numeral 1 denotes a gun body made of synthetic resin, in which a high voltage generator 2 is embedded in the lower central part thereof, and a spring 3, a nozzle seat 4, and a nozzle adapter 5 having conductivity are interposed. A high voltage is applied to the nozzle 6.

A paint reservoir 7 is formed in the upper portion near the tip of the gun body 1 and through which a high pressure paint is pumped from the rear end of the gun body 1 through a passage (not shown). It is designed to be ejected from the nozzle 6 through the valve port 21, the through hole 9, the spring 3, the nozzle seat 4, and the nozzle adapter 5.

A valve rod 10 having a tip facing the valve opening 21 of the valve seat 8 passes through the paint reservoir 7, and the valve rod is tightly and freely slidably fitted in the packing unit 11. It is connected to a rod 13 which is tightly and slidably fitted to the packing retainer 12. At the rear end of the gun body 1, an air cylinder 18 having a piston 15 slidably fitted in a cylinder 14 is constructed.
Is urged to the left in the figure by the elasticity of the coil spring 17 and moves to the right when pressurized air is supplied from the through hole 16, and this piston 15 has the rod 1
3 are connected. A notch 19 is formed in the upper center of the gun body 1, the center of the rod 13 is exposed, and the gun body 1 is covered with a cover 20.

This embodiment has the above-mentioned structure, and the piston 15
When pressurized air is supplied into the cylinder 14 through the through hole 16 of the valve rod 15 and the piston 15 moves to the right in the figure against the elastic force of the coil spring 17, the valve rod 10 moves in the same direction together with the rod 13 to move the valve seat. 8, the valve opening 21 opens, and the paint supplied to the paint reservoir 7 is atomized and ejected from the nozzle 6 through the passage 9 and the like, and at the same time, the high voltage generator 2 causes the nozzle 6 to have a high voltage. The mist-like paint is charged and is attracted to the object to be painted.

Here, since the pressurized air supplied into the cylinder 14 contains water, the water travels through the rod 13 and advances toward the valve rod 10, but at the center of the rod 13. Since the portion is exposed in the notch 19, the water does not reach the valve rod 10 due to evaporation into the atmosphere.

Therefore, the creeping distance from the nozzle 6 to which the high voltage is applied is up to the exposed portion of the rod 13, and the leakage of the high voltage through the rod 13 is prevented.

In this embodiment, the cover 2 is attached to the gun body 1 in consideration of the adhesion of the paint mist to the exposed portion of the rod 13.
Although it is covered with 0, a slight amount of water from the rod 13 can be released from the screw portion for attaching the cover 20.
If the cover 20 is insufficient, the cover 20 may be provided with a vent hole so as to cover and attach the vent hole.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.

[Explanation of symbols]

 1: Gun body 2: High voltage generator 6: Nozzle 10: Valve rod 13: Rod 18: Air cylinder 19: Notch 21: Valve mouth

Claims (1)

(57) [Claims] 1. A spray gun for electrostatic coating in which a valve opening is provided in a paint passage formed in a gun body, and a valve rod which opens and closes by contacting with the valve opening is connected to a piston of an air cylinder via a rod, A spray gun for electrostatic coating, wherein a part of the gun body is cut off to expose the rod.