JPS5855820B2 - powder coating equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a powder coating apparatus that allows conveyance and adjustment of powder coating materials to be controlled using compressed air.

Generally, in a powder coating apparatus that performs coating by spraying powder coating, powder is conveyed using an ejector pump provided at the bottom of a powder supply tank.

In this case, the means to adjust the conveyance amount of powder coating is as follows:
An air passage for adjusting paint is provided separately from an air passage for transporting paint, and the amount of paint carried out is adjusted by the ratio of the amount of air released from both passages.

In other words, this paint is carried out using compressed air ejected from the paint conveying air passage facing the valve chamber of the ejector pump.
The inside of the valve chamber is made to have a negative pressure, whereby the powder paint flows out from the powder supply tank in the upper part and is supplied to the painting gun.

Adjustment of the amount of paint discharged at this time depends on the increase or decrease of the negative pressure generated in the valve chamber, but if this is done only by increasing or decreasing the pressure or the amount of compressed air ejected from the nozzle, the paint discharge rate will also be affected. The coating conditions also fluctuate, making it impossible to maintain good coating conditions.

In order to improve this point, the end of the air passage for paint adjustment is made to face near the nozzle at the end of the air passage for paint conveyance in the valve chamber, and compressed air is jetted out appropriately to measure the increase or decrease of the negative pressure in the valve chamber. There is also a type that adjusts the amount of paint discharged.

However, such devices have a structure in which the amount of air released from both air passages is adjusted by independent adjustment mechanisms, making the adjustment complicated and resulting in a time-consuming preparation process. Moreover, the painting operation itself also has the drawback of increasing instability.

Furthermore, it has become complicated and difficult to obtain reproducibility.

The present invention has been made in view of the above circumstances.

That is, in the present invention, the air passage for transporting paint and the air passage for adjusting paint facing the valve chamber of the ejector pump provided at the bottom of the powder supply tank are connected to the air amount adjustment mechanism interposed in the pressure reducing valve, and the air amount is adjusted. It is possible to easily and reliably adjust the paint delivery speed and paint delivery amount by changing the ratio.

Hereinafter, the present invention will be explained with reference to drawings of embodiments.

In FIG. 1, 1 has at least one air inlet passage 1a connected to a compressor 2 and a pressure reducing valve 3 on one side, and two valve seats 1ct1 facing the air inlet passage 1a and having the same diameter.
In addition to providing air outlet passages 1e and 1f at the lower end of d,
This is an air adjustment mechanism in which the sharp lower end of the valve body 1gt1h parallel to the valve seat 1ct1d can be inserted into the air adjustment mechanism.
The parts mesh with each other and move and rotate in opposite directions, and the valve body 1g
t 1 h can be relatively raised and lowered.

Reference numeral 4 denotes an ejector pump installed at the lower part of the powder supply tank 5, and one end of the valve chamber 4a of the ejector pump 4 is connected to the end of the paint conveying air passage 4b connected to the air outlet passage 1f of the air adjustment mechanism 1. The formed nozzle 4c is disposed, and a paint regulating air passage 4d whose tip is connected to the air outlet passage 1e of the air regulating mechanism 1 is exposed diagonally below the nozzle 40, and the other end of the valve chamber 4a is arranged. Paint outlet 4e
A paint gun 6 is connected to the paint outlet 4e.

To explain this operation now, first, compressed air produced by the compressor 2 passes through the pressure reducing valve 3 and flows into the air outlet passages 1e and lf branched from the air inlet passage 1a of the air adjustment mechanism 1.

Here, the speed at which the paint is discharged from the powder supply tank 5 can be adjusted by adjusting the total amount of air flowing into the ejector pump 4. In other words, this can be done by adjusting the pressure reducing valve 3 installed on the source pressure side of the air amount adjustment mechanism 1. It can be easily adjusted by adjusting.

Further, the amount of paint discharged is adjusted by two interlocking valve bodies 1gtlh incorporated in the air amount adjustment mechanism 1, and the valve bodies 1g and 1h have at least a pitch diameter and a sharp lower end shape. The aperture diameter of the valve seat 1ct1d is the same, and both valve bodies 1gtlh are rotated in mutually opposite directions by the meshing of the holes 1i and 1j that protrude from the upper surface of the air amount adjustment mechanism 1. Therefore, the amount of air flowing into the paint conveying air passage 4b and paint regulating air passage 4d in the ejector pump 4 from each outlet passage increases or decreases inversely proportionally, and the total amount is a constant amount. becomes.

Therefore, by simply operating one camera 11 or 1j attached to the upper part of the air amount adjustment mechanism 1, the amount of paint discharged can be easily adjusted while maintaining a constant paint discharge speed.

FIG. 2 shows another embodiment, in which a part of the compressed air for conveyance is branched into the paint regulating air passage of the ejector pump via an air regulating mechanism.

That is, compressed air is branched from the compressor 2 through the pressure reducing valve 3 to a branch hose 7.8, one branch hose 1 is connected to the paint conveying air passage 4b of the ejector pump 4, and the branch hose 8 is connected to the paint gun 6. The hose 8' end drawn out from the air quantity regulating valve 1' is connected to the paint regulating air passage 4d.

Adjustment of the paint delivery speed at this time can be easily adjusted by adjusting the total amount of air flowing into the ejector pump 4 by adjusting the pressure reducing valve 3 as in the previous embodiment.

Further, the amount of paint carried out is adjusted by adjusting the ratio of the amount of air sent to the paint conveying air passage 4b of the ejector pump 4 and the amount of air sent to the paint adjusting air passage 4d using another branched hose 8. This is done by the air regulating valve 1' of the paint gun 6, which is interposed between the air passage 4d and the paint regulating air passage 4d.

That is, by appropriately throttling the air amount adjusting valve 1', the amount of air flowing into the paint regulating air passage 4d of the ejector pump 4 is reduced, and the amount of air sent to the paint conveying air passage 4b is reduced accordingly. Therefore, it is possible to reduce the amount of paint discharged while maintaining a constant paint discharge speed.

Further, by opening the regulating valve 1', the amount of paint discharged is increased.

Further, in another embodiment shown in FIG. 3, the paint jetting speed is increased in proportion to the increase in the paint jetting amount.

That is, the air passage 4 for transporting the paint of the ejector pump 4
b. Two valve bodies 1g arranged in the air amount adjustment mechanism 1 communicating with the air passage 4d for adjusting the paint.

Air inlet passages ia, la' are independently faced to the air inlet passages 1a, la', respectively, and separate pressure reducing valves 3.3' are provided in the air inlet passages 1a, la'.
and compressors 2 and 2' are connected.

Here, the set pressure of the pressure reducing valve 3', which communicates with the paint conveying air passage 4b in the ejector pump 4 via the air inlet passages 1a, 1a' and the air outlet passage 1st1f, is set to that of the other pressure reducing valves 3. By setting the pressure higher than the set pressure, the amount of ejected paint can be increased or decreased in proportion to the increase or decrease in the amount of ejected paint.

As mentioned above, the present invention provides an air amount adjustment mechanism that can change the ratio of air amounts flowing into the paint conveying air passage and the paint adjustment air passage in the ejector pump disposed at the bottom of the powder supply tank. By disposing the pump between the pressure reducing valve and the ejector pump, the amount and speed of paint discharge can be easily and quickly adjusted.

In addition, each of these air amount adjustment mechanisms has a simple structure and is easy to handle, so it can withstand long-term use and has the effect of reducing handling errors during painting work.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a two-part cutaway side view, and FIGS. 2 and 3 are side views showing other embodiments. 1...Air adjustment mechanism, 1a...Air inlet passage, 1c, 1d°...Valve seat, 1et1f
...Air outlet passage, Igtlh...
Valve body, 11, 1j...Same photo, 2...
Compressor, 3... pressure reducing valve, 4... ejector pump, 40... valve chamber, 4b...
... Air passage for transporting the paint, 4d... Air passage for adjusting the paint, 5... Powder supply tank.

Claims (1)

[Scope of Claims] 1. In a powder coating device for adjusting the amount of powder, the ejector pump is attached to the lower part of the powder supply tank and has an air passage for transporting the paint and an air passage for adjusting the paint. At least one of the two air passages, the air passage for use and the air passage for adjusting the paint, is connected to an air amount adjustment mechanism equipped with a valve body that changes the flow area, and the above-mentioned two air passages are adjusted by adjusting the valve body. A powder coating device characterized by being able to freely adjust the flow rate ratio of two air passages. 2. The air volume adjustment mechanism is configured such that one valve body moves forward and backward with respect to the valve seat in order to change the flow area of one side, and the flow area of the valve seat of the other passage that moves in the opposite direction due to the movement of the one valve body. 2. The powder coating apparatus according to claim 1, wherein the other valve element to be changed is arranged in parallel so that the flow rate ratio of the two air passages can be adjusted. 3 A part of the compressed air sent to the paint conveying air passage of the ejector pump is branched as appropriate and guided to an air volume adjustment mechanism, and the air volume adjustment mechanism is connected to the paint adjustment air passage of the ejector pump. Claim 1
Powder coating equipment described in section. 4. The powder coating apparatus according to claim 2, wherein the air inlet passageway that guides the two regulating valve sections interlocked with the air amount regulating mechanism is connected to an independent pressure reducing valve arranged separately. 5. Powder coating according to claim 2, wherein a pressure reducing valve is provided in the air inlet passage of the air amount adjustment mechanism, and the air outlet passage faces the paint conveying air passage and the paint adjustment air passage of the ejector pump, respectively. Device.