JPS625241Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a spray gun for painting which can atomize the paint and form a uniform thin coating film based on the fact that the paint discharge port is formed in the shape of a long hole.

In conventional painting spray guns that use air, the paint discharge port is usually formed in a circular hole, and as a result, the paint is discharged in the form of a rod, which results in insufficient mixing with the air, resulting in an increase in the amount of sprayed paint. At the same time, it became difficult to atomize the paint.

In this invention, by forming the paint discharge port in the shape of a long hole, it is possible to ensure sufficient mixing with air, and even when the flow rate of the paint is large, the paint can be reliably atomized and a uniform coating film can be formed. The purpose of the present invention is to provide a painting spray gun according to the present invention, and one embodiment thereof is shown in the drawings below, taking as an example the case where the painting spray gun of the present invention is adopted as an automatic spray gun that performs painting operations by remote control. This is explained by:

In the figure, the painting spray gun 1 of the present invention is
By arranging a large number of small-diameter light transmitting ports 3a in a straight line at the tip of the paint nozzle 2, the paint discharge port 3
It is formed into a long and narrow hole. Paint nozzle 2
The cylindrical base 4 is provided with a smaller-diameter cylindrical portion 5 at the front end via a step, and a protrusion 6 extending left and right in the radial direction is continuously provided on the front wall of the cylindrical portion 5.
The paint discharge port 3 is formed by closely arranging the through holes 3a of relatively small diameter which communicate with the guide hole 9 of the base 4. The paint nozzle 2 is provided with an outer flange portion 10 around the front end of the base portion 4, and a groove 11 is recessed in the outer flange portion 10 from the front and back. The base 4 of the paint nozzle 2 is inserted into a central hole 14 which is transparently provided in the center of the case 12. The case 12 is a stepped cylindrical body having a body part 15 and a neck part 16, and a circumferential groove for inserting an O-ring 13 is formed at the front end of the center hole 14.
A threaded portion is cut on the outer periphery of the air cap 6, and the air cap 17 is fixed to the front surface of the neck portion 16 with a gap g using a lock nut.
A paint nipple 19 for connecting a paint pipe is screwed into the center hole 14 of the case 12, and the body 1
An air nipple 20 for introducing compressed air is attached to the outer periphery of the case 5, and a guide hole 21 is formed in the air nipple 20 to pass through the case 12 and reach the front surface of the neck 16. Furthermore, air cap 17
By providing a cone portion 22 on the front surface of the threaded portion with a cylindrical portion in between, and providing a horizontally elongated hole 24 in the front plate 23 of the cone portion 22 through which the projection 6 can be inserted with a small gap, the projection can be fixed. An air jet port 25 surrounding the paint discharge port 3 is formed adjacent to the paint discharge port 3 between the outer periphery of the paint discharge port 6 and the inner surface of the elongated hole 24 . Note that the groove 11 is formed at the base end of the cone portion 22 of the air cap 17.
A key groove 26 having the same width as the above is formed, and by fitting a key 29 between the key groove 26 and the groove 11, the elongated hole 24 of the air cap and the protrusion 6 are positioned, and the air outlet 25 is properly aligned with the paint. It is made to match the circumference of the discharge port 3. Note that the case 12 is provided with eye bolts 30 for attachment.

However, in the gun 1 of the present invention, when compressed air is connected to the air nipple 20 and a paint tube is connected to the paint nipple 19 to forcefully feed air and paint, the compressed air first flows through the air nipple 20 and the guide hole 2.
1, the air outlet 24 passes through the gap g between the front surface of the case 12 and the inner surface of the air cap 17, and the groove 11.
At the same time, the paint passes through the paint nipple 19 and becomes a thin flat stream through the juxtaposed small-diameter through holes 3a of the paint nozzle 2, and is ejected from the paint outlet 3 into a long and narrow stream, making it easy to mix with air. Atomized to form a uniform coating film.

As mentioned above, the painting spray gun of this invention is
In addition to forming the paint discharge port into a long and narrow hole,
Since the air nozzle is closely surrounded by the air nozzle, it is possible to atomize the paint and form a more uniformly thick sprayed film compared to the conventional air nozzle consisting of a simple circular hole that ejects in the shape of a rod. Even when the flow rate of paint increases, it can be prevented from becoming coarse, making it suitable for use in high-viscosity paints and low-viscosity paints, as well as for spraying FRP resins or applying mold release agents. It can be used as an automatic spray gun as well as a handgun. In addition to the case where the paint discharge port is formed by arranging small-diameter through holes as in the above embodiment, it may also be formed into a long hole shape using a slit as shown in FIG. As shown in FIG. b, such elongated holes can be provided, for example, in a radial pattern.

[Brief explanation of the drawing]

Figure 1 is a front view showing one embodiment of the present invention;
The figure is a sectional view, FIG. 3 is an exploded perspective view showing the main parts, and FIGS. 4a and 4b are front views showing other examples of the paint spout. 2...Paint nozzle, 3...Paint discharge port, 25...
...Air outlet.

Claims (1)

[Scope of utility model registration request] A spray gun for painting, characterized in that a paint discharge port of a paint nozzle is formed into an elongated hole shape, and the paint discharge port is surrounded by an air jet port formed around and adjacent to the paint discharge port.