Precision spraying valve

Abstract

The invention relates to a precision spraying valve with a piezoelectric wafer serving as a driving source. The precision spraying valve comprises a cavity, a one-way valve, the piezoelectric wafer, a needle head, a gas hood and the like. The piezoelectric wafer serving as the driving source presses spraying materials into the needle head, compressed gas in the gas hood descends to disperse the spraying materials into tiny liquid beads to be deposited on the surface of a workpiece. Since a traditional needle valve is not used for controlling spraying or spraying stop of the spraying materials, when the precision spraying valve is used for precision spraying, large edge allowance caused by factors such as eccentricity and form and location tolerance of the needle valve is eliminated.

Description

technical field [0001] The invention relates to a precision spraying valve. Background technique [0002] Spray valves are widely used in the spraying of conformal paint, ink, solvent and other materials. Chinese patent 200920134037.8 discloses a spraying valve, which is also the most widely used spraying valve. The minimum width it can spray is relatively large, generally greater than 5mm, and the edge tolerance is also large, generally ±2mm. For precision micro-spraying (workpieces with a width less than 3mm), the edge tolerance is particularly obvious. The common practice is to place the sprayed workpiece within the effective width of the spray valve, and protect the parts that do not need to be sprayed, which is extremely inconvenient to use. convenient. The main reason for the large and uneven edge tolerance is: due to the small amount of spraying, the opening distance of the firing pin is relatively small, and the amount of spraying material along the firing pin exit...

AI Technical Summary

Problems solved by technology

For precision micro-spraying (workpieces with a width less than 3mm), the edge tolerance is particularly obvious. The common practice is to place the sprayed workpiece within the effective width of the spray valve, and protect the parts that do not need to be sprayed, which is extremely inconvenient to use. convenient

The main reason for the large and uneven edge tolerance is: due to the small amount of spraying, the opening distance of the firing pin is relatively small, and the amount of spraying material along the firing pin exiting the valve port is also small, and the surface tension plays a leading role in the flow of spraying material Effect, it is easy to distribute unevenly when it flows, some along the inner wall of the nozzle, some along the tip of the striker, the unevenness of the material also leads to a large edge tolerance after atomization

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