JPS6014623B2 - electrostatic painting equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a static paint coating device using conductive paint, and in particular, it is capable of cleaning the conductive paint supply route to the electrostatic paint machine in a short time, and is capable of cleaning the conductive paint supply path after cleaning. The present invention relates to an electrostatic coating device that can prevent high voltage leakage from a paint supply path.

Conventionally, there has been a first path leading from an insulated paint tank to an inlet of an insulated paint flow switching valve via an insulated pump, and a first path leading from the first outlet of the paint flow switching valve to an electrostatic atomizer. An electrostatic coating device is used which includes a second path and a third path leading from the second outlet of the paint flow path switching valve to the paint tank.
The tortoise-conducting paint in the tank is supplied to the electrostatic coating machine.

Moreover, when painting is interrupted, the first route and the third route are passed through and the paint is returned to the tank. By the way, in this type of apparatus, when a day's painting work is finished or when changing the color of the paint, it is necessary to clean and dry the entire path from the paint tank to the electrostatic atomizer. Therefore, conventionally, the outlet of the third route was removed from the paint tank, the first route and the third route were passed through each other, and the paint pump inside the paint tank was used to discharge the cleaning liquid to the outside, and then the cleaning liquid was poured into the paint tank. The pump is operated to clean the first route and the third route, then the first route and the second route are operated to clean the first route and the second route, and then the first route is cleaned. The method used has been to remove the inlet from the paint tank, connect it to the air supply path, and repeat the same sequence as described above, which has resulted in the following drawbacks. (2) After cleaning the 1st and 3rd paths, the 1st and 2nd paths are washed, and after drying the 113th path, the 1st and 2nd paths are dried, so cleaning and drying takes a considerable amount of time.

■ When cleaning the second route (including the electrostatic sprayer),
Since the cleaning liquid flows through the first path and into the second path, the total length of the path becomes long, and cleaning takes a considerable amount of time.

(2) When flowing the cleaning liquid into the second path, a pump in the middle of the first path is used, but since this pump is for supplying electrostatic paint V, its capacity is generally small.

Therefore, cleaning takes a considerable amount of time. ■Generally, compared to the first and third routes from the paint tank to the flow switching valve, the second route from the flow switching valve to the electrostatic coating machine is set longer by a hose or the like.

For this reason, the long time required for cleaning the second path has become a bottleneck. The present invention provides a first
・By providing an electrostatic coating device that can separately clean and dry the 3rd path and the 2nd path from the paint flow separation valve to the electrostatic coating machine, the total cleaning and drying time can be shortened. In this system, a cleaning path consisting of an insulated hose is provided through an insulated valve in the insulated conductive paint supply path from the paint supply source to the electrostatic coating machine, and in the cleaning path, The cleaning liquid supply path and the compressed air supply connection section are connected in parallel through a grounded flow path switching valve.

The invention will be explained in detail below with reference to the illustrated embodiments.

In the figure, 1' is a paint tank insulated with an insulator 2, 3
is a paint supply pump insulated with insulator 4, and 5 is insulator 4
6 is an electrostatic atomizer, 7 is a first path from the paint tank 1 to the inlet 5A of the paint flow path switching valve 5 via the pump 3, and 8 is a paint flow path switching valve. A second path 9 leads from the first outlet 58 of the valve 5 to the electrostatic atomizer 6, and a third path 9 leads from the second outlet 5C of the paint flow path cutting valve 5 to the paint tank 1.

The above is a well-known configuration, and when performing final coating, the first path 7 and the second path 8 are made to pass through each other by the switching valve 5, and a conductive paint such as a water casing paint, a metallic paint, etc. and operates the pump 3 to supply conductive paint to the electrostatic coating machine 6. In this case, the object to be coated (not shown) is generally grounded and a negative voltage is applied to the electrostatic atomizer 6.
For this reason, the tank 1, the pump 3, and the first to third paths 7 to
A high voltage is applied to 9 through the conductive paint, and the insulators 2,
4 ensures insulation. Moreover, when the painting is interrupted as necessary, the first path 7 and the third path 9 are transported by the sliding door valve 5, and the paint sent from the tank 1 by the pump 3 is transferred to the tank via the third path 9. It is returned to within 1. At the first outlet 5B of the paint flow path switching valve 5, a fourth path 10 is provided which is branched from the second path 8 and is insulated.

The fourth path as a cleaning path is formed of an insulated hose made of polytetrafluorethylene or the like. Note that the fourth path 10 may be of an insulating structure, for example, an insulating hose interposed in the middle of a conductive hose. An insulated check valve 11 for preventing paint from flowing from the second path 8 to the fourth path 10 is provided at the branching point between the second path 8 and the fourth path 10. This inflow blocking means is not limited to a check valve, but may be an on-off valve, for example. In the fourth path 1, a cleaning liquid supply path 13 and a compressed air supply path 14 are connected in parallel via a flow path switching valve 12 that is separate from the paint flow path switching valve 5.

Cleaning and drying of the electrostatic coating device made of the above-mentioned material is carried out as follows. After painting is completed, the high voltage is cut off, the first route 7 and the third route 9 are made to pass through each other by the paint passage valve 5, the outlet 9A of the third route 9 is taken out of the tank 1, and the pump 3 is turned off. The paint in tank 1 is discharged to the outside.

Then, when the tank 1 is empty, the cleaning liquid in the tank 1 is poured into the tank 1, and the pump 3 is operated to clean the first and third paths 7 and 9. The first tank may be a separate container containing cleaning liquid. In this case, water is used as the cleaning liquid when the conductive paint is a water-soluble paint, and thinner is used when the conductive paint is a metallic paint. It is preferable to mix air into the first and third channels 7 and 9 in order to improve their cleaning performance. This cleaning air mixing operation is repeated as many times as necessary, and finally the inside of the hose is filled with air. Meanwhile, the first path 7 and the third path 9 are controlled by the paint flow path switching valve 5. After that, the flow path switching valve 12 connects the cleaning liquid supply path 13 and the fourth
The cleaning liquid is fed into the second path 8 from the cleaning liquid supply V supply path 13 via the fourth path 10, and the inside of the second path 8 is cleaned.

In this case, water or thinner from factory piping with a certain pressure is used as the cleaning liquid as described above, but since it can be sent to the second path 8 without passing through the pump 3, it is not necessary to send a large amount. It is possible to shorten the cleaning time. Drying in the second path 8 is carried out by the air supply path 14 using the flow path switching valve 12.
This is done by driving the fourth route 10 and the fourth route 10. The cleaning and drying operations are repeated as many times as necessary, and the final drying operation is performed. That is, it is important to dry the insulating hose 10 sufficiently so that the high voltage does not leak from the check valve 11 to the rare road switching valve 12 when a high voltage is applied at the start of the next coating. As described above, the first, second and third routes 7, 8
, 9 is dried, and the cleaning/drying work is completed. Therefore, when painting starts, the fourth path 10 itself is insulated,
Moreover, since the inside of the fourth path 10 is dry, the insulation of the second path 8 is confirmed. In addition to the above-mentioned embodiments, the present invention is also applicable to a paint flow switching valve 5 in which a cleaning liquid supply channel, an air supply channel, etc. are connected in parallel with the first path 7 so as to be able to function effectively, and a flow channel switching valve 12 in which a cleaning liquid supply channel, an air supply channel, etc. It is also possible to connect a plurality of cleaning liquid V supply channels in a switchable manner in parallel, or to connect to the rear end of a conventional color changing device having a lotus hole.

In any case, it goes without saying that the same effect is achieved in that there is no need to insulate this cleaning path. Since the present invention achieves the above-mentioned advantages, it has the following effects.

■ The first and third paths from the paint tank to the paint flow path switching valve and the second path from the paint flow path switching valve to the electrostatic sprayer can be cleaned and dried separately and at the same time. Significant time savings can be achieved.

(2) Since the fourth cleaning path is dried with air after the cleaning solution flows, insulation is maintained and high voltage leakage from the conductive paint supply path is prevented.

Therefore, it is possible to prevent electrostatic coating defects and the like caused by leakage of static electricity. ■ The insulation of the cleaning path is maintained by air drying, so even if the cleaning solution is a good conductive solvent, the connection source can be used with it grounded. For example, in the case of water-soluble paint, the water used as the cleaning liquid is
This means that V can be directly supplied from the water faucet to the flow path switching valve 12, and no special equipment is required.

[Brief explanation of drawings]

The figure is an overall configuration diagram of an electrostatic coating apparatus showing an embodiment of the present invention. 1...Paint tank, 3...Pump, 5
......Paint flow path switching valve, 5A...Inlet,
5B...1st exit, 5C...2nd exit, 6
...Electrostatic coating machine, 7...First route, 8
...Second route, 9...Third route, 10
...4th path, 12... flow path switching valve,
13... Cleaning liquid supply path, 14... Compressed air supply Kamakura road.

Claims (1)

[Claims] 1. A cleaning path consisting of an insulated hose is provided via an insulated valve in the insulated conductive paint supply path from the paint supply source to the electrostatic coating machine, and a grounded flow path is provided in the cleaning path. An electrostatic coating device characterized in that a cleaning liquid supply path and a compressed air supply path are connected in parallel via a switching valve.