JPS5837472Y2 - spray gun - Google Patents

Description

[Detailed explanation of the idea] This invention relates to improvements to spray guns.

The spray gun is designed to spray paint by mixing the air flow ejected from the gap between the central hole of the air cap and the paint nozzle with the paint.

By the way, in spray painting, it is desirable to spray the paint in as atomized particles as possible, regardless of the particle size of the paint, and for this purpose, various changes are made in the position, ejection direction, or diameter of the air holes drilled in the air cap. Improvements have been made with a lot of effort.

However, it is technically difficult to promote atomization by the above means, and the atomization is extremely difficult.

Therefore, an object of the present invention is to provide a spray gun that can produce a more atomized and softer coating than before by adjusting the airflow ejected from the side air holes (square holes) of the air cap. do.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

In the figure, reference numeral 1 denotes an air hole provided in the center of an air cap 2, and a plurality of auxiliary air holes 3 and side air holes 4 are provided around the outer periphery of this air hole 1.

Reference numeral 5 designates a paint nozzle, which is integrally connected to the gun body 7 through a screw portion 6 provided at its rear end.

Further, a paint passage 8 is provided in the center, and a paint spout 9 is provided at the tip of the paint passage 8, and the spout 9 is opened and closed by moving a needle 10 corresponding to the paint spout 9 back and forth.

Further, a pair of front and rear flange portions 11.12 are formed on the outer periphery of the paint nozzle 5 via a peripheral wall 14, and an annular air reservoir 13 is formed between the flange portions 11.12.

Reference numeral 15 indicates a plurality of air holes extending through the circumferential wall 14 in the axial direction, and reference numeral 16 indicates a plurality of air holes extending through the rear flange 12.

17 is a circular regulator.

This annular adjustment body 17 is interposed between the front end surface of the spray gun body 7 and the rear end surface of the rear flange 12 of the paint nozzle 5.

Further, on the front side of the adjustment body 17, an outer circumferential wall 18 and an inner circumferential wall 19 are provided.
An annular groove is formed between the inner and outer circumferential walls 18 and 19 to provide an air reservoir 20, and the surface side of the air reservoir 20 is brought into close contact with the rear side of the flange 12 of the paint nozzle 5, and further on the rear side. A recess 22 forming an air pocket is formed by the outer peripheral wall 21.

Note that the recess 22 may be provided in the adjustment body 17 as in this embodiment, or may be provided in the distal end surface of the gun body 7.

Reference numeral 23 designates a valve hole through which the annular air reservoir 20 passes through a compressed air passage 24 of the gun body 7, and the air passage 24 also communicates with the recess 22.

In addition, in the figure, 25 is a valve body provided corresponding to the valve hole 23, and 26 is a valve body provided corresponding to the valve hole 23.
2 is an air passage formed in the gap between the inner periphery of the annular adjustment body 17 and the outer periphery of the paint nozzle 5; 27 is a cap band;
8 is an O-ring.

Next, to describe the operation of the above structure, when the valve body 25 closes the valve hole 23, the compressed air flow passing through the compressed air passage 24 goes around the recess 23, and then passes through the air passage 26 and passes through the air hole. 15, and is ejected from the air holes 1 and auxiliary air holes 3 to perform painting.

Therefore, no air is ejected from the side air holes 4.

When the valve body 25 is released, the recess 22 is removed from the compressed air passage 24.
A part of the compressed air that has circulated flows into the annular air reservoir 20 from the valve (L23) of the regulator 17 and stagnates therein, and further flows into the annular air reservoir 13 from the air hole 16 of the paint nozzle 5,
It accumulates here as well, and then blows out from the side air hole 4 of the air cap 2.

Therefore, compared to the case where the air is accumulated in only one annular air reservoir 13 as in the past, there is no problem such as pulsation in the air flow itself, and the air flows from the side air hole 4 in an ideal rectified state. is ejected, which has a great effect on making the paint finer and producing a softer coating.

In this way, by opening the valve body 25, it is possible not only to adjust the pattern as in the conventional case, but also to satisfy both the atomization of the paint and the soft coating.

Furthermore, since the O-ring 28 is fitted between the outer periphery of the rear side of the adjustment body 17 and the tip of the gun body 7, there is no possibility that air will leak from the joint portion of the cap band 27 as in the conventional case.

According to the spray gun of the present invention, as is clear from the above description, the regulator 17 is interposed between the paint nozzle 5 and the gun body 7, and the compressed air passage 24 on the gun body 7 side and the air cap 2 are connected to each other. In addition to the first annular air reservoir 13 between the paint nozzle 5 and the air cap 2, a second annular air reservoir 20 is provided in the middle of the compressed air passage between the side air hole 4 and the air cap 2. The airflow ejected from the side air holes 4 has no pulsation and is ejected in an ideal rectified state, and the paint is atomized, making it possible to apply a soft coating.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of the main parts, and FIG. 2 is a perspective view of the paint nozzle. 2 is an air cap, 4 is a side air hole, 5 is a paint nozzle,
7 is a gun body, 17 is an annular adjustment body, 18 is an outer peripheral wall, 1
9 is an inner peripheral wall, 20 is an annular air reservoir, 23 is a valve hole, and 24 is a compressed air passage.

Claims (1)

[Scope of utility model registration request] It includes a gun body 7, a paint nozzle 5 connected to its tip, and an air cap 2 fitted over the tip, and a first annular air reservoir 13 formed between the paint nozzle 5 and the air cap 2 and air A second annular air reservoir 20 that communicates with the side air hole 4 of the cap 2 and faces the rear end surface of the paint nozzle 5 and the gun body 7 is provided between the rear end surface of the paint nozzle 5 and the front end surface of the gun body 7. A regulating body 17 having a valve hole 23 communicating between the compressed air passage 24 on the side and the second annular air reservoir 20 is installed, and the paint nozzle 5 is provided with the first and second annular air reservoirs 13. ．．
A spray gun characterized by being provided with an air hole 16 that communicates with the air hole 20.