JPS6063397A - Prevention of defective painting when conveyor stops in electrodeposition painting - Google Patents

Abstract

PURPOSE:To prevent the surface of a material to be coated from being unevenly painted by generating the same flow as the liquid flow which arises on moving of the material to be coated in an electrodeposition liquid when the material stops in the electrodeposition liquid owing to stoppage of a conveyor. CONSTITUTION:A material 4 to be coated is continuously dipped by a hanger 6 detained to a conveyor 5 into a cationic electrodeposition liquid 2 contained in an electrodeposition cell 1 by which the material 4 is electrodeposition-painted. The liquid 2 is sucked through a suction port 8 by a pump 9 and is discharged from injection nozzles 7 to the extent of avoiding clogging of the nozzles 7. When the material 4 stops in the liquid 2 owing to stoppage of the conveyor 5, a motor is controlled by a sensor 11 which senses the stop to increase the liquid flow by the pump. The similar liquid flow to the liquid flow generated when the material 4 moves is thereby generated in the liquid 2. Settling of the components having the larger specific gravity in the liquid 2 is thus prevented and the surface of the material 4 is uniformly painted without unevenness.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for electrocoating a uniform coating film on the surface of a conductive object, and particularly to a method for preventing coating defects caused by conveyor stoppage.

(Prior art) In electrodeposition coating, if the coating conveyor is unavoidably stopped due to some kind of malfunction or relation to the next process, the liquid flow such as stirring of the solution does not occur to move the object to be coated. Among the components, pigments with higher specific gravity fall into the liquid and deposit on the surface of the object to be coated, resulting in a problem of uneven coating on the surface.

In such cases, paper (1) was used to eliminate the unevenness, but this takes a lot of time and the film becomes thin, resulting in problems such as 11 (11) and 11 (lower finish quality). occurs.

(Objective 1 of the Invention) The present invention was made to solve the above-mentioned problem of the conventional problem.When the coating conveyor is stopped, pigments with low specific gravity among the components of the electrodeposition solution fall down =J The objective is to prevent IJ from coating unevenness on the surface of the object to be coated, which occurs when the coating is applied.

(Structure of the Invention) In the method of the present invention, when a stoppage of the coating conveyor due to an accident or the like is detected by the sensing device in the 7-stem electrodeposition coating,
The injection device is automatically operated to generate a liquid flow similar to the liquid flow generated by the movement of the object to be coated when the conveyor is operating, preventing the settling of pigments with heavy specific gravity among the components of the electrodeposition solution, and spraying the liquid onto the object to be coated. This is an IL method for preventing coating defects when a conveyor is stopped in electrodeposition coating, which is characterized by preventing coating defects due to unevenly distributed pigment adhesion to the surface.

(Effects of the Invention) According to the present invention, when the coating conveyor is stopped, a liquid flow is generated by the solution jet in the upper part of the bathtub, thereby preventing the pigment with low specific gravity from falling in the electrodeposition liquid components, and average'd
This prevents uneven coating on the surface of the object to be coated, and eliminates the need for traditional methods such as sanding with paper. Furthermore, it is possible to prevent painting defects such as a decline in finish quality that occurs as a result.

(Example) A detailed description will be given below based on an example shown in the attached drawings.

In FIGS. 1, 2, and 3, this electrodeposition apparatus R contains a cationic electrodeposition liquid 2 in an electrodeposition tank 1.

Seed electrodes 3 facing each other and functioning as anodes are installed in a state immersed in the electrodeposition liquid 2, and in this electrodeposition tank 1, a workpiece 4 in contact with the cathode 2 is held on a conveyor 5. Bangka 6
It is continuously immersed in water.

Further, a spray nozzle 7 is provided near the object 4 to be coated and inside the seed electrode 3 so as to spray the spray toward the bathtub -1= section.

Electrodeposition liquid 2 is sucked into the nozzle 7 through a suction port 8 provided on the surface of the melt tank 11E and is supplied under pressure from a pump 9 through a pipe 10.

The pump 9 is operated by a same-volume motor and is connected to the coating conveyor s.
Normally, when the conveyor belt is in operation, the conveyor belt 11, which senses the stoppage t:, sends enough liquid to prevent clogging of the piping 10 and jet f4J nozzle 7. ) by setting a negative number to 1ilj, it is controlled to generate a liquid pressure that produces a liquid flow similar to the liquid flow caused by the movement of the object 6 when the conveyor is operating.

In this embodiment, the pumping location of the pump 9 can be automatically changed by the processor 11 that detects when the conveyor stops, thereby preventing wasteful power consumption during operation.

Here, the conventional electrodeposition apparatus is provided with an injection riser for stirring the pigment precipitated in the suction part of the electrodeposition tank 1.
1E sucked in from the suction port provided in the eaves of the electrodeposition tank
The liquid is supplied under pressure by a pump.

Embodiment 2 is a part of the pump and piping used in this jet riser according to the present invention. 'd% This is commonly used as a bath liquid supply means for the injection nozzle 7 for preventing defects.

In FIG. 4, the difference (χ) from FIG. 3 is shown.

A pump 13 for pumping the electrodeposition liquid 2 to the injection nozzle 7 and the injection riser 12 is shared, and the pipe In is divided into a nozzle pipe 10a and a riser pipe Ob in the middle.

Furthermore, nozzle pulp 14 and riser pulp 15 are provided in the middle of the pipes 10a and 10b, respectively.
The pulps 14 and 15 are provided with pulp drive devices 16 and 17 controlled by the sensor 11. The pulp]
4.15 is a conveyor (
When the vehicle is moving, the injection riser 12 is operated, and on the other hand, the injection nozzle 7 and piping 11 are opened at a nearly closed position to deliver enough liquid to prevent clogging. 11, the pulp opening degree is controlled to have an inverse relationship.

In this embodiment, the pump I3 for supplying the electrodeposition liquid 2 under pressure is shared by the injection nozzle 7 and the injection riser 12.

Here, since the injection riser 12 is already in use, by sharing the pump, there is less need to revise the Nk 41i1, and costs for the revamp can be saved.

Furthermore, when Examples 1 and 2 are combined, by changing the number of poles of the drive motor of the common pump, the J of the bottom of the heavy loading tank and the soil area when the conveyor is stopped is +5! Stirring can also be done at the same time.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a front view of the coating device, and FIG. 2I'y, I is a plan view of the coating device. FIG. 3 is a cross-sectional view of the coating device, and FIG. 4 is a cross-sectional view of the coating device according to the second embodiment. 1... Electrodeposition tank, 2... Electrodeposition liquid, 3... Seed electrode, 4
...Object to be coated, 5...Conveyor, 6...Hanger, 7
... Injection nozzle, 8 ... Suction port, 9-13 ... Pump, 10, 10a, 10b ... Piping, 11 ... Sensor, 12 ... Injection riser, 14 ... For nozzle Valve, 15... Pulp for riser, 16/17 - Pulp drive value IN. Patent applicant Kazuo Konishi, representative of Toyo Kogyo Co., Ltd. Figure 1 Figure 30. Figure 134

Claims (1)

[Claims] In an electrocoating method using an energizing bath method in which the object to be coated is continuously completely poured into an electrodeposition paint solution containing pigment by a conveyor and a coating film is deposited on the surface of the object, the conveyor stops.J:
, the sensing device is activated, the pump and the pulp are controlled by the activation signal, and the solution injection nozzle is activated so that a flow similar to the liquid flow generated by the movement of the object to be coated is generated when the conveyor is in operation. Method for preventing coating defects when conveyor stops during electro-deposition coating.