JPS6038050A - Air cap of spray gun - Google Patents

Abstract

PURPOSE:To stably form a uniform spray pattern by injecting a flat jet stream from the beginning, by forming a side surface air opening into a profile opening shape. CONSTITUTION:A paint is introduced into a nozzle 1 from an introducing port 9 and injected from a paint jet orifice 4. Compressed air is injected from the central air opening 7 comprising an annular slit formed between the center orifice 6 of an air cap 5 and the paint nozzle 1 and impinged to and diffused into the paint injected from the jet orifice 4 to form a spray stream of fine paint particles. In addition, compressed air is also injected from a pair of side surface air orifices 8, 8 which are provided to the leading end of the air cap 5 and collided in front of the paint jet orifice 4 and impinged to the spray stream from both sides thereof to flatten the spray stream.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a 2% cap for an air spray gun.
More specifically, the present invention relates to a complete cap having side air ports that form a stable spray ring pattern suitable for painting with a spray stream of paint atomized by compressed air.

Conventionally, as shown in Fig. 1, the air cap of a general air spray gun has a paint nozzle 12 with a paint spout 11 in the center, which atomizes the paint to form a spray stream. There is. Furthermore, in order to accommodate various coating conditions such as various objects to be coated, paint materials, finishing conditions, etc., the spray pattern is shaped into an ellipse suitable for painting by colliding compressed live air flow from the air ports 14 on both sides of the spray flow from the center. It is deformed into a shape or an oval shape.

However, as the spray pattern becomes larger, simply by colliding a simple circular jet from the side air vents with the central spray, only the colliding portion becomes constricted, making it impossible to form a spray pattern with uniform density. For this purpose, by once colliding with the jet of the auxiliary air port 15 coming out from near the central air port.

The circular jet from the side air port 14 is flattened.

It was colliding with the central spray stream. For this reason, in addition to the central air vent, the air cap requires a large number of side air vents and auxiliary air vents, which requires complicated and accurate hole machining, and requires a large number of man-hours, making it difficult to manufacture. However, the pattern tends to become unstable. In addition, the spray pattern must be checked even after processing, which poses a problem in mass production and lower production costs.

The reason why various air ports are used for pattern stabilization is to make the combined air flow into an appropriate flat air rush pattern, but because of the composite air flow, not only does the pattern itself lack stability. , the speed of the forward jet from the auxiliary air ports provided around the central air port is accelerated, giving the worker a hard feeling about the spray itself.
This gave the impression that the work was difficult.

In view of the above-mentioned circumstances, the present invention provides a side air port with an irregular opening shape, so that a flat jet is ejected from the beginning, thereby stably forming a uniform spray pattern, improving the atomization efficiency, and improving the coating quality. The purpose of this invention is to provide an air cap that can obtain atomization conditions suitable for smooth tooth surface formation, and another purpose is to reduce the number of processing steps by simplifying the processing of the air port of the air cap. reduction.

The purpose is to reduce defective rates and production costs, and to provide an air cap suitable for mass production.
Still another object is to provide an air cap that eliminates auxiliary air ports and provides a soft-feeling spray stream suitable for operations where the spray speed is not accelerated.

The present invention will be explained below with reference to drawings of embodiments.

3 is a paint nozzle provided at the tip of a needle valve 3 placed in the center of the gun body 2. The candy nozzle 1 introduces paint from the rear, and a paint spout 4 is provided at its tip. The outer periphery of the tip of the paint nozzle l is surrounded by a suction cap 5 placed on the outside.
A central 9 lower hole consisting of an annular slit is formed between the center hole 6 and the center hole 6. In addition to the central air lower, the air cap 5 has side air ports 8.8 which are formed by a pair of single holes for forming a spray pattern that cross collide on the axis of the paint nozzle l and in front of the paint nozzle 4. has. The side air ports 8, 8 have an opening shape that is symmetrical with respect to a plane that is common to the center line with the upper center and the lower thrust, respectively, and is asymmetrical with respect to other lines and planes, and 8.8 has a substantially flat irregular shape as shown in Fig. 5 (a), (b), and (c) (- has a bulge 8a on the upper middle side and the side closer to the vital lower part (indicated by the arrow in the figure). Approximately crescent-shaped, inverted triangle.

They are purchased in irregular shapes other than circular and rectangular, such as dish-shaped and V-shaped. 9 is a paint inlet, and 10 is an air passage.

Next, to explain the present invention in detail, first, the paint is introduced into the paint nozzle l through the paint inlet 9, and as the needle box 3 moves back, it is ejected from the paint spout 4 at the center of the tip of the paint nozzle l. On the other hand, the compressed air is injected through the air passage ``0'' to the middle upper air lower air passage formed by the annular slit formed between the center hole 6 of the air cap 5 and the paint nozzle 1. A spray stream of fine paint particles is formed by colliding and diffusing the paint ejected from the paint jetting port 4. Furthermore, the compressed air is located at the tip of the air camp 5 and is supplied to the paint outlet 4.
The air is injected from a pair of side air ports 8, 8 that collide in front of the air.

The spray from the center collides with the spray from both sides to flatten the spray to form an oval or elliptical spray pattern suitable for painting.

In this case, the side air ports 8, 8 have an opening shape that is symmetrical only with respect to a plane that is roughly common to the center line with the central air lower, and moreover, the side air ports 8, 8 have a bulge 8a on the side closer to the center 2% lower.
Since it is formed into a substantially flat irregular shape other than a circular or square shape, the jet of compressed air injected from the side air ports 8, 8 becomes flat from the beginning and collides with the spray flow from the center. Moreover, since the side air port 8.8 has a bulge 8a on the side closer to the center, the spray stream is caused to collide with the spray flow at the upper middle portion of the bulge 8.8, where the width gradually increases. That is, in the narrow part d] of the air injection pattern (air pattern), the spray stream at the center is first expanded, and the slightly wider part of the air pattern collides with the spray stream. Therefore, a live air stream with an appropriate width can be used at each collision stage, resulting in stable atomization and efficient atomization.

As described above, the present invention forms the paint ejected from the paint jetting port into an atomized spray stream by jetting compressed air from the central air port, and also 111, which has a substantially flat shape other than a circular or square shape that is symmetrical only with respect to a plane common to each line, and has an opening shape of the side air vent close to the center of the air vent.
By forming a large bulge in 11, the jet of compressed air from the llIO surface nitrogen air port becomes flat from the beginning, and since the side air port has a bulge on the side closer to the center, the jet of compressed air from the llIO surface nitrogen air port becomes flat from the beginning, and the side air port has a bulge on the side closer to the center. On the other hand, it is possible to collide with a part that gradually widens from the center, which does not cause a defective pattern, achieves stable atomization and efficient atomization, and obtains a spray pattern suitable for painting. be able to. In other words, compared to the conventional case of combining various types of live airflow from a plurality of auxiliary air ports and circular openings of side air ports to form a live airflow for pattern formation, it is possible to create the desired airflow using only a pair of side air ports. Since it is not a composite flow, there is no wasted airflow and atomization is improved. Furthermore, (11+) the collision angle of the air flow from the air ports is obtuse compared to the conventional composite flow, and since there is no acceleration of the spray flow by the auxiliary air port, the velocity of each particle is low, and the mist is soft, making it easier for workers to paint. This is an easy pattern to work with.

Moreover, since only the pair of irregularly shaped side air ports need to be machined into the air cap, hole machining is simplified.
This has the effect of reducing the number of processing steps and making the air cap suitable for mass production.

[Brief explanation of drawings]

FIG. 1 and FIG. 2 are cross-sectional views showing a conventional thrust cap;
and a perspective view. Figures 3 to 5 show embodiments of the present invention, with Figure 3 being a sectional view, Figure 4 being a perspective view, and Figures 5 (a), (b), and (c) showing the side entrance facing the front. FIG. l...Paint nozzle 4...Paint spout 5...Air cap 7...Center air inlet 8...Side nitrogen inlet 8a・・・・・・
...Bulge patent applicant Iwata Painting Machinery Co., Ltd. Sardine Figure 1 Figure 2 Figure 4 Figure 5 (A) (B) (C)

Claims (1)

[Claims] 1. For a paint nozzle that has a paint spout in the center, an annular central air port is formed around the spout, and an annular central air port is formed in front of the spout in an opposing position so that the nitrogen flow crosses and collides with the spray flow. In a spray gun having a side air port, the yA11 side air port is formed with an opening shape other than circular or square that is symmetrical only with respect to a plane common to the center line of the center air port and both side air ports, respectively. The nitrogen cassof T2 of the spray gun is characterized by being designed to inject a flat stream of nitrogen air. An air cap for a spray gun according to claim 1.