JPS6229083Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a spray gun for stably obtaining a small discharge amount.

Among spray guns that normally spray paint, etc. using compressed air, spray guns that pump paint, etc. through a pressurized tank have a small discharge rate, e.g.
If cc/min is required, the nozzle diameter must be very small, for example, about 0.4 mm. However, if an even smaller discharge amount is required, 0.2mm
It may be as follows. In other words, in the case of multi-liquid sprays, sprays of curing agents, catalysts, etc. have a low viscosity close to that of water, and have a small discharge rate of 10 to 30 c.c./min, so a very small nozzle diameter is required. be done. However, in practice, such a small diameter makes it difficult to process and to obtain stable discharge. In other words, in order to maintain a small discharge amount with pressure feeding using a pressurized tank, in addition to the bore size described above, the pressurizing pressure must be adjusted, but in this case, the pressure difference changes depending on the position of the spray gun, making it unstable. becomes.

The purpose of this invention is to obtain a spray gun with a small discharge amount without using a small nozzle diameter.
The liquid passage before reaching the nozzle diameter is constructed of an extremely thin pipe, and the discharge amount is limited by the resistance of the passage.

The drawings show one embodiment of the present invention.
The figure shows the overall configuration, the second figure shows the hand tube section, and the third figure shows the
The figures show the nozzle apertures. Spray gun 1 has an air cap 2 and a nozzle 3 at its tip, and spray liquid is sent to nozzle 3 from paint supply hose 4 through hand tube 5. Hand tube 5 is a thin metal pipe with an inside diameter of 0.4 mm, and a plastic tube 7 is attached to the outside for protection. As shown in Fig. 2, guides 10 are fitted to both ends of hand tube 5, and together with the plastic tube 7 layered on the outside, it is fastened by a sheet 11 and a cap nut 12. The inside diameter of hand tube 5 is selected depending on the discharge conditions, but for this type of spray gun it should be 1 mm or less, preferably 1.5 mm.
A diameter of about 0.3 mm to 0.5 mm is used. Furthermore, the nozzle opening 8 of the nozzle 3 is configured so that the tip of the needle valve 9 with a small diameter is always in a position, thereby reducing the effective flow area of the nozzle opening 8. That is, in the embodiment, the nozzle opening diameter is 0.7 mm, and the small diameter part is 0.6 mm, so that the effective inner diameter is slightly less than 0.4 mm. By selecting the effective inner diameter of the nozzle opening and the inner diameter of the hand tube so that they are almost similar, a more stable discharge amount can be maintained. In this way, the material that has passed through the paint hose of normal diameter is narrowed while passing through the hand tube 5, and the flow rate is reduced by the resistance and the flow becomes a small, stable flow, and the material is finally discharged from a nozzle with almost the same flow area.

By performing painting with the spray gun configured as described above, even if the position of the spray gun changes, the effect on the discharge amount is kept to a minimum and the discharge amount is stable. Uniform coating can be achieved even if the amount is slightly affected.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a part of a spray gun according to an embodiment of the present invention, FIG. 2 is an enlarged sectional view of a hand tube connection part, and FIG. 3 is a sectional view of a nozzle diameter portion. 1...Spray gun, 3...Nozzle, 4...Paint supply hose, 5...Hand tube.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. A paint nozzle with a nozzle opening at its tip and a needle valve inside, which communicates with the paint chamber and is connected to a paint supply hose that guides paint from a pressurized paint source. A spray gun for a small discharge amount, characterized in that the hand tube has a passage cross-sectional area approximately equal to the opening area of the nozzle opening. 2. The spray gun according to claim 1, wherein the hand tube is a metal pipe with an inner diameter of 1 mm or less.