JPH0555194B2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a spray gun nozzle.

(Prior art) Spray guns are widely used in painting work because they have high painting efficiency and produce a beautiful finish.
However, when painting with a spray gun, atomized paint and solvent vapor are scattered around.
There is a problem in that workers are contaminated and have a negative impact on their health.

FIGS. 6a and 6b are a sectional view and a front view showing the tip structure of a conventionally used spray gun. In the figure, 1 is a paint nozzle, and 2 is an air cap provided around the tip of the paint nozzle 1. This air cap 2 has a center hole 3 that opens around the tip of the paint nozzle 1, an auxiliary air hole 4 that opens near the outer periphery of the center hole 3, and a side air hole 5 that opens on the inner surface of the air cap 2. . The central hole 3 allows the paint to be ejected from the paint nozzle 1 to atomize it, the side air holes 5 make the spray pattern oval, and the auxiliary air holes 4 make the spray pattern stable and particles uniform.

(Problems to be Solved by the Invention) In order to safely perform painting using such a spray gun, conventional measures have been taken, such as, for example, performing painting in a paint booth. This paint booth is configured to suck in and exhaust harmful substances such as paint and solvent vapor, and also to form a constant air flow to supply clean air to workers and protect them from harmful substances. However, it is not possible to completely protect workers from contamination because the object to be painted itself blocks this air flow and obstructs the suction and exhaust of harmful substances, or the paint bounces off the object to be painted.
On the other hand, powder coating and electrostatic coating have been put into practical use in recent years, but these coatings are easily affected by external airflow because the speed of spraying the paint from the nozzle is low, and depending on the airflow conditions, the paint may will scatter, resulting in paint loss and reduced coating effectiveness.

Therefore, the present invention was made in view of the above problems, and its purpose is to reduce the contamination of workers from harmful substances such as paint and solvents during painting, and to improve the painting work. To provide a spray gun which can perform spraying safely, prevent loss of paint, and enhance coating effect.

(Means for Solving the Problems) In order to achieve the above object, the present invention has the following configuration.

That is, in the nozzle of a spray gun that atomizes the paint from the paint nozzle and discharges it in the form of a spray using a jet of compressed air, when the paint is discharged in the form of a spray from the paint nozzle, an air curtain is placed around the ejected paint. In order to blow out the compressed air forward in a cone shape so as to shield the paint with a similar action, a fresh air nozzle is provided outside the paint nozzle and has a ring-shaped opening at the end of the nozzle for blowing out compressed air. do.

(Function) When atomizing and discharging paint from the paint nozzle,
At the same time, compressed air is jetted forward in a cone shape from a fresh air nozzle located outside the paint nozzle, and the sprayed paint is covered with fresh air. The discharged paint is shielded by the action of the air curtain, which prevents the paint from splashing back toward the operator and improves the reachability of the paint.

(Embodiments) Hereinafter, preferred embodiments of the present invention will be described in detail based on the accompanying drawings.

FIG. 1 is a sectional view showing one embodiment of a spray gun nozzle according to the present invention, and FIG. 2 is a front view. In the figure, 10 is a paint nozzle, and 12 is paint flowing through the paint nozzle 10. 14
16 is a central hole whose tip opens at the outer periphery of the paint nozzle 10, and 16 is a fresh air nozzle which opens at the outer periphery of the central hole 14 in the form of a circular slit. Both the central hole 14 and the fresh air nozzle 16 communicate with the compressed air inflow side.

The fresh air nozzle 16 has its base 1
8 is made of a stretchable elastic material, and the peripheral edge of the aperture 20 is brought into contact with the outer peripheral surface of the base 18 .
Reference numeral 22 denotes a spring that constantly biases the inner circumferential surface of the base 18 in an outward direction.

A cap 24 supports the center hole 14, the fresh air nozzle 16, etc. around the paint nozzle 10. This cap 24 has a second
As shown in the figure, auxiliary air holes 4 and side air holes 5 are provided as in the conventional example. This side air hole 5 is located outside the fresh air nozzle 16.

Next, the operation of the above-described embodiment will be explained.

FIG. 1 is an explanatory diagram showing how the paint is being discharged from the paint nozzle 10, and the paint 12 is caused by compressed air being jetted from the center hole 14 of the cap 24, so that the tip of the paint nozzle 10 is in a negative state. The pressure builds up, atomizes and sprays out. Further, at this time, compressed air is blown out in a cone shape from the fresh air nozzle 16 located on the outer periphery of the center hole 14, and the compressed air is discharged so as to envelop the atomized paint. The flow rate and velocity of the compressed air blown out from the fresh air nozzle 16 are adjusted by a valve or the like. In addition, since the base 18 of the flexible air nozzle 16 has elasticity, the aperture 2
By pushing the outer circumferential surface of the base 18 with
The blowing direction of the compressed air blowing out can be adjusted as appropriate.

Several effects can be achieved by using a spray gun equipped with this fresh air nozzle 16, and FIGS. 3, 4, and 5 are explanatory diagrams showing examples of its use.

FIG. 3 shows an example in which the air blowing angle of the fresh air nozzle 16 is set so as to cover the periphery of the paint spray, and 26 is a spray gun;
8 is a paint spray discharged from a paint nozzle 10, and 30 is fresh air blown out from a fresh air nozzle 16. In this example,
Since the atomized paint is wrapped and shielded by the fresh air 30, the paint and solvent will not be scattered towards the operator, and the paint that has been sprayed onto the object to be coated and bounced off will not be scattered. can be prevented. Further, by being shielded by the fresh air 30, the coating spray 28 can be guided to the object to be coated without being affected by external air currents. As a result, paint is efficiently sprayed onto the object being painted, preventing paint loss,
The coating effect can be enhanced.

FIG. 4 shows an example in which the fresh air nozzle 16 has a large blowing angle and the fresh air 30 is used in the form of an air curtain between the object to be coated and the worker. By using it in this way, it is possible to reduce the exposure of workers to paints and solvents. In addition, in this case, a side air hole 5 is provided on the inner circumferential side of the flexible air nozzle 16 to prevent the paint spray 28 from being sprayed.
The deformation of the pattern and the action of the flexible air 30 may be prevented from interfering with each other.

FIG. 5 shows an example of using a spray gun in a painting booth. In the figure, reference numeral 32 denotes a painting booth, and this painting booth 32 is exhausted through a filter 34 provided at the rear, and an air flow is formed from the front to the rear of the painting booth 32. 36 is an object to be painted. The spray gun 26 is used in front of the painting booth 32, uses fresh air 30 in the form of an air curtain, and adjusts the flow rate of the fresh air 30 to an amount commensurate with the amount of air taken into the painting booth 32.

This painting method has the same effect as a push-pull type ventilation system, and can suppress indoor air from being exhausted. That is, painting booth 3
When only 2 is used, indoor air is also taken in at the same time, indoor cooling and heating air is exhausted, and the indoor pressure is made negative, but the intake air amount of the painting booth 32 is replenished by the fresh air 30. This makes it possible to suppress indoor air discharge.

It goes without saying that by using both the paint booth 32 and a spray gun equipped with a fresh air nozzle 16, it is possible to further reduce the scattering of harmful substances such as paint and solvents on workers. do not have.

In addition, in the above-mentioned embodiment, the flexible air nozzle 16 was provided in the shape of a circular slit.
The shape of the fresh air nozzle 16 is not limited to a circular slit shape, and the fresh air is ejected so as to wrap around the outside of the paint that is spreading in a spray shape, thereby preventing the paint from scattering around. It is fine as long as it prevents it. For example, multiple small-diameter nozzles that communicate with the compressed air inflow side can be arranged in a circle on the outside of the paint nozzle, or they can be placed at opposite positions across the paint nozzle so as to block only a specific direction. It is also possible to arrange nozzles that eject fresh air, or to provide nozzles that eject fresh air at four orthogonal positions.

Furthermore, the above-mentioned fresh air nozzle can be similarly attached to a spray gun used for powder coating and electrostatic coating.

(Effects of the Invention) According to the present invention, as described above, by providing the spray gun with a fresh air nozzle, it is possible to reduce the scattering of paint, solvent, etc. and the splashing of paint from the object to be painted. This allows workers to be protected from harmful substances and work more safely. Furthermore, since the paint spray can be guided to the object to be painted without being affected by external air currents, it is effective in reducing loss of paint and increasing the coating effect.

The present invention has been variously explained above with reference to preferred embodiments, but the present invention is not limited to these embodiments, and it goes without saying that many modifications can be made without departing from the spirit of the invention. That's true.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of a spray gun nozzle according to the present invention, FIG. 2 is a front view, and FIG.
Figures 4 and 5 are explanatory diagrams showing usage examples, and Figure 6
Figures a and b are a sectional view and a front view showing a nozzle of a conventional spray gun. 10...Paint nozzle, 12...Paint, 14...
Center hole, 16...Fresh air nozzle, 18
...Base, 20...Aperture, 22...Spring, 24...
...Cap, 26...Spray gun, 28...Paint spray, 30...Fresh air, 34...
...Filter, 36...Object to be painted.

Claims (1)

[Scope of Claims] 1. In a nozzle of a spray gun that atomizes paint from a paint nozzle and discharges it in the form of a spray by blowing out compressed air, when the paint is discharged in the form of a spray from the paint nozzle, the paint that is discharged In order to blow compressed air forward in a cone shape so as to shield the surrounding area with an air curtain-like effect, a fresh air nozzle is provided outside the paint nozzle, the nozzle end of which blows out compressed air opening into a ring shape. A spray gun nozzle with a unique feature.