JPH0448504B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a spray nozzle in which an air nozzle is added to an airless type painting spray device.

<Prior art> In general, paint spray equipment uses an air atomization system that atomizes paint through collision and diffusion of compressed air, and an airless system that atomizes paint by spraying it from a spray nozzle using high liquid pressure. Pressure) atomization systems are widely used. Although there are other types of atomization such as electrical atomization and mechanical atomization, the above two types are the mainstream as devices for atomizing paint.

However, each method has its advantages and disadvantages. For example, air spray uses approximately 1,000 times more air than paint, resulting in a lot of mist being scattered. Airless spraying has problems in that the pattern and amount of paint ejected cannot be freely adjusted, and pattern defects called tails are likely to occur.

Recently, in order to solve the above-mentioned drawbacks, spray devices that combine airless atomization with air atomization have appeared. However, there is still much room for improvement in these devices, and a spray device that is easier to use and more efficient is desired.

<Objective of the Invention> The present invention involves blowing air separately in the vicinity of the nozzle tip exit in opposite directions in the long axis direction of the pattern to eliminate the tail, and further applying other air from the short axis direction of the pattern width to reduce the pattern width. The purpose is to be able to freely adjust the pattern width beyond the specifications of the nozzle tip.

<Structure of the Invention> The present invention includes an airless spray nozzle for hydraulic atomization that has a substantially lip-shaped opening and forms an oval spray pattern, and that the lip-shaped opening is arranged in front of the nozzle at longitudinally opposite positions. is provided with a first air port having an opening and is injected into the sprayed paint before atomization that is injected from the nozzle, and is further provided with a lip-shaped opening of the nozzle in front of the first air injection port. A second air injection port is provided opposite to the rectangular diameter position and injects a flat air stream into the area where the sprayed paint is atomized, and the spray nozzle is capable of eliminating the tail and changing the pattern width. be.

<Example> Hereinafter, the present invention will be described in detail based on the drawings of the example.

In FIGS. 1 and 2, 1 is a hydraulic spray type spray gun body, and a nozzle tip 6 having an approximately lip-shaped opening arranged in the center of the front side of the gun body 1 is a spray gun body of a hydraulic spray type.
It is held by a nozzle holder 2 screwed into the nozzle holder 2. Furthermore, a cap 4 is attached to the nozzle holder 2 by screwing a cap nut 3, and is located between the nozzle tip 6 and the nozzle holder 2, and is used for erasing tails arranged on both sides of the tip opening 6a in the longitudinal direction. A slit hole 7 with a constant width is provided. In addition, a plurality of air holes 5 (three in the figure) are formed facing each other in the cap 4, which is perpendicular to the slit hole 7, and are arranged on the axis of the tip opening 6a. Air is injected toward the area where the sprayed paint has been atomized. The air hole 5 and the slit hole 7 are connected through an air passage 9 provided in the nozzle holder 2, respectively.

To explain this effect, first, like the conventional airless spray nozzle, the paint 8 with a predetermined liquid pressure is
is injected from the gun body 1 through the nozzle tip 6.

Here, a slit hole 7 is provided at a position a in the long diameter direction of the pattern near the tip opening 6a, and in order to spray air c, the tail part of the paint pattern 8a as shown in FIG. is erased by the pressure of air, and the particle group is once transformed into a round shape into pattern 8b or pattern 8c, and then moves toward the atomization point.

Next, air is injected perpendicularly to the sprayed paint from the air hole 5 of the cap 4 to a region on the axis of the tip opening 6a and ahead of the atomization point of the sprayed paint. That is, by colliding air (square air) from the rectangular diameter direction b of the pattern width, the rounded pattern 8b or 8c is stretched to a predetermined oval pattern 8d suitable for painting. In this case, the pattern width can be freely adjusted to a pattern width that exceeds the specifications of the nozzle chip by changing the number of air holes 5 and the blowing pressure. In addition, the air holes are appropriately distributed so that the collision positions of the air injected from the large number of air holes 5 are not concentrated at one point in the pattern, and the air is injected as a band-shaped flat stream. It is composed of

FIGS. 3 and 4 show other embodiments of the air holes, which are slit holes and square holes.

In this case, a slit hole 7' is bored all around the vicinity of the nozzle tip 6, and a slit-like air hole 5' is used as a hole for blowing air to a region beyond the atomization point.

That is, by making the pattern of the paint 8 sprayed from the nozzle tip 6 into a circular spray pattern and spraying air with a width wider than the slit-shaped air hole 5' to the area beyond the atomization point, uniform mist distribution can be achieved. Pattern width can be adjusted freely.

<Effects of the Invention> As described above, the spray nozzle of the present invention has an air hole or a slit hole for eliminating the tail at the front of the airless nozzle tip, injects air from these holes, and also has a spray nozzle that is on the axis of the nozzle tip. ,
Air is further sprayed from a number of air holes or slit-shaped air holes formed to inject from the opposite position toward the area beyond the atomization point of the sprayed paint, resulting in large pattern changes and small airflow. Efficient pattern changes are possible. Therefore, even if the spray pressure is low, the tail can be eliminated, so spraying can be performed at low pressure, resulting in good coating efficiency and improved atomization. Furthermore, since the pattern width can be freely varied, the range of coverage of each nozzle chip is widened, and the number of types of nozzle chips can be reduced.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a longitudinal sectional side view of the main part, FIG. 2 is a front view, FIG. 3 is a longitudinal sectional side view of the main part of another embodiment, and FIG. 4 is a front view of the main part. FIG. 5 is an explanatory diagram of the pattern. 1... Gun body, 2... Nozzle holder, 4... Cap, 5, 5'... Air hole, 6... Nozzle tip, 7, 7'... Slit hole.

Claims (1)

[Scope of Claims] 1. A hydraulic atomizing airless spray nozzle having a substantially lip-shaped opening and forming an oblong spray pattern is disposed at the center, and longitudinally opposing positions of the lip-shaped opening in front of the nozzle are provided. is provided with a first air injection port having an opening and for injecting the spray paint before atomization injected from the nozzle, and further in front of the first air injection port, a lip-shaped opening of the nozzle A spray nozzle characterized in that a second air injection port is provided opposite to a rectangular diameter position and that injects a flat air stream into an area where the sprayed paint is atomized. 2. The spray nozzle according to claim 1, wherein the first air injection port comprises an annular slit formed around the nozzle. 3. The spray nozzle according to claim 1, wherein the second air injection port comprises a plurality of holes arranged in parallel. 4. The spray nozzle according to claim 1, wherein the second air injection port is an elongated slit-shaped opening.