JPH0343237Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to an electrodeposition coating apparatus in which an object to be coated is placed on a hanger of a conveyor and immersed in an electrodeposition tank.

[Conventional technology]

In an automobile painting line, an automobile body to be coated is placed on a conveyor hanger and conveyed through a pretreatment process, an electrodeposition process, and a washing process in this order.

When an automobile body that has undergone a pretreatment process and is transported to an electrodeposition process is immersed in an electrodeposition tank for electrodeposition painting, for example, a positive electrode is provided in the electrodeposition tank,
An automobile body suspended on a hanger of a conveyor is connected to a negative electrode via the hanger, so that an electrodeposited coating film is formed on the surface of the automobile body.

By the way, the shapes of hangers on which automobile bodies are placed and transported are known to be gate-shaped or C-shaped (see Figures 2 and 4 of Publication No. 62-9329), and which shape is adopted? However, a portion of the hanger is interposed above the automobile body, and a conveyor rail for suspending the hanger is also present.

For this reason, droplets of pre-treatment liquid or electrocoating paint adhering to the hanger may drip onto the top surface of the automobile body placed on the hanger, or lubricating oil or dirt adhering to the conveyor rail may fall and cause electrolysis. There was a risk that the paint film would be defective.

[Problem that the invention attempts to solve]

Therefore, the inventor of the present invention has devised a method for transporting the object to be coated by placing it on an L-shaped hanger, removing a part of the hanger and the conveyor rail from above the object, and removing the pre-treatment liquid and electrocoating liquid from the bottle. An attempt was made to prevent paint film defects from occurring due to falling parts, lubricating oil, dirt, etc.

However, in an L-shaped hanger consisting of a vertical part and a horizontal part, due to the load of the workpiece placed on the horizontal part, the upper end of the vertical part acts as a fulcrum in the opposite direction to the extension direction of the horizontal part. Since force is applied, in order to resist the rotational force and keep the object in a horizontal state,
It is necessary to provide a hanger support roller on the lower end side of the L-shaped hanger, and to lay a guide rail along the conveyance path of the L-shaped hanger to guide the hanger support roller in contact with it. It has been found that the following problem occurs when this guide rail is installed in an electrodeposition tank.

In other words, the guide rail installed in the electrodeposition tank is connected to an electrode such as a diaphragm electrode installed along the side wall of the electrodeposition tank, and a cover placed on an L-shaped hanger that is connected to a polarity different from that of the electrode. Since the guide rail is interposed between the electrode and the object to be coated, the guide rail becomes an obstacle that blocks the flow of current generated between the electrode and the object to be coated, and prevents the electrodeposition paint from reaching the surface of the object to be coated. A problem arises in that the throwing power (throwing power) is reduced.

In addition, a liquid flow is generated in the electrodeposition tank to agitate the electrodeposition paint in order to prevent precipitation of paint components, but if a guide rail is laid across the entire area in the electrodeposition tank, this It may obstruct the flow of paint.

Furthermore, maintenance and inspection of the guide rails laid throughout the entire area within the electrodeposition tank is extremely difficult.

Where did the inventor conduct further experiments and research?
The above-mentioned problems can be solved all at once, and at the same time, the present invention is not limited to just that, when the object to be coated that is placed on an L-shaped hanger and immersed in an electrodeposition tank is, for example, an automobile body having a hollow part. We have now completed an electrodeposition coating device that can automatically tilt the body within the electrodeposition tank to vent air within the body.

[Means for solving problems]

That is, in the electrodeposition coating apparatus according to the present invention, the hanger of the conveyor on which the object to be coated is placed and immersed in the electrodeposition tank is formed in an L shape, and the hanger support roller attached to the lower end side is brought into contact with the hanger. Guide rails for keeping the object to be coated placed on the L-shaped hanger in a horizontal state are provided on the entrance side and the exit side of the electrodeposition tank, omitting the intermediate part.

[Effect]

According to the present invention, the guide rail that keeps the workpiece placed on the L-shaped hanger in a horizontal state by making contact with the hanger support roller attached to the L-shaped hanger is provided on the entrance side and the exit side of the electrodeposition bath. Since it is installed on the tank side, it prevents the object to be coated from falling from the L-shaped hanger when the object is submerged in the electrodeposition paint in the tank or taken out from the tank. Accidents caused by accidents are prevented.

In addition, the guide rail is omitted between the tank entry side and the tank exit side, and between the part to be coated that is immersed in the electrodeposition tank and the electrode installed in the electrodeposition tank. Since it does not interfere with the flow of current generated in the process, it does not reduce the coverage of the electrodeposition paint on the surface of the object to be coated.

In addition, since the L-shaped hanger passing through the middle omitted part of the guide rail loses its support at that part and tilts, the object to be coated placed on the L-shaped hanger is automatically tilted. When the electrode has a hollow portion, the air in the hollow portion is removed, thereby reliably preventing electrodeposition defects due to adhesion of air bubbles.

Furthermore, the guide rails are provided on the entry and exit sides of the tank, and the intermediate section is omitted, which makes maintenance and inspection work extremely easy, and at the same time reduces the flow of electrocoated paint that is generated to stir the paint components. There is little risk of interfering with

〔Example〕

Hereinafter, embodiments of the present invention will be specifically described based on the drawings.

FIG. 1 is a schematic view showing an example of an electrodeposition coating apparatus according to the present invention, and FIG. 2 is a view taken along the - line.

In this example, the object to be coated is an automobile body W.
The hanger 2 of the conveyor C, which is loaded and immersed in the electrodeposition tank 1, has a vertical part 2a and a horizontal part 2b.
The conveyor frame 3 to which the conveyor C is attached is placed on the horizontal part 2b of the L-shaped hanger 2 and immersed in the electrodeposition tank 1, and the automobile body W and one side wall of the electrodeposition tank 1 are It is installed in the space above the electrodeposition tank 1, interposed between the electrodeposition tank 4L and the electrodeposition tank 1.

The conveyor frame 3 is formed into a substantially gate shape,
A conveyor rail 5 is attached to the center of the horizontal portion 3a, and the upper end side of the vertical portion 2a of the L-shaped hanger 2 is suspended from the conveyor rail 5.

Note that a C-beam 6 is attached to the upper end of this vertical portion 2a, and the C-beam 6 has a section extending from the vertical portion 3b on the side wall 4L side of the conveyor frame 3 toward the inside of the conveyor frame 3. A protruding current collector 7 is brought into sliding contact to connect the L-shaped hanger 2 with a polarity different from that of the diaphragm electrodes 8R and 8L provided in the electrodeposition bath 1.

Also, from the lower end of the vertical part 3b of the conveyor frame 3 to the vertical part 2a of the L-shaped hanger 2, the C-shaped steel 6 is connected.
Guide rails 10A and 10B of a certain length are provided at the tip of the angle 9 that protrudes horizontally toward the
A hanger support roller 11 is attached to the electrodeposition tank 1 so as to come into contact with it from the side wall 4L side.

On the other hand, on the lower end side of the vertical part 2a of the L-shaped hanger 2, a constant fixed portion is fixed to the tip of an insulating support 12 that protrudes along the side walls 4L on the entrance side and the exit side of the electrodeposition tank 1, respectively. Length guide rails 13A, 13B
A hanger support roller 14 that abuts is attached.

In addition, the guide rail 10A provided on the tank entry side
and 13A are arranged in parallel with each other and have the same length, and guide rails 10B and 13B are provided on the outlet side.
are arranged parallel to each other with the same length, and between the guide rails 10A and 10B and the guide rail 13.
The intermediate portions between A and 13B are each omitted.

Here, the hanger support roller 11 that is guided by coming into contact with guide rails 10A and 10B provided on the conveyor frame 3 receives the load of the automobile body W placed on the horizontal part 2b of the L-shaped hanger 2, and The upper end side of the shaped hanger 2 supports the force that tends to rotate it in the direction of the side wall 4R of the electrodeposition tank 1 using the hanger support roller 14 in contact with the guide rails 13A and 13B as a fulcrum.

On the other hand, the hanger support roller 14 that is guided by coming into contact with the guide rails 13A and 13B has the lower end side of the L-shaped hanger 2 connected to the guide rails 10A and 13B.
The hanger support roller 11 in contact with B is used as a fulcrum to support the force that tends to rotate the electrodeposition bath 1 in the direction of the side wall 4L.

Next, a vertical part 3c on the side wall 4R side of the conveyor frame 3 has a dogleg shape projecting toward the upper surface of the automobile body W placed on the horizontal part 2b of the L-shaped hanger 2 and immersed in the electrodeposition bath 1. An auxiliary electrode 15 is provided.

This auxiliary electrode 15 is attached to a piston rod 17 of a cylinder 16 disposed at the lower end of the vertical portion 3c of the conveyor frame 3 via an insulating material 18, and is attached to diaphragm electrodes 8R, 8L provided in the electrodeposition bath 1.
is connected to the same polarity as the car body W.
It moves up and down to maintain an appropriate distance between the poles according to the vehicle height.

In other words, the distance between the auxiliary electrodes 15 and the top surface of the vehicle body W can be controlled by the cylinder 16 without performing troublesome control to vary the voltage applied to the auxiliary electrodes 15 according to the vehicle height of the vehicle body W. The film thickness of the electrodeposited film can be easily controlled by an extremely simple operation that can be varied.

Also, depending on the car model, there are cases where there is no problem even if the film thickness on the roof part is a little thinner than other parts, and in this case, it is preferable to keep the film thickness constant over the entire car body W. Conventionally, the electricity supply to the auxiliary electrode 15 is stopped because the priority is to save paint, but even if the electricity supply is stopped, if the auxiliary electrode 15 is immersed in the electrodeposition paint, the intermediate potential will drop. In order to maintain the electrode action, the adhesion of the electrodeposition paint to the upper surface of the automobile body W was promoted, and the effect of saving paint could not be sufficiently achieved.
On the other hand, if the auxiliary electrode 15 is provided so as to be movable up and down as in this example, it can be completely extracted from the electrodeposited paint when it is not needed, thereby increasing the paint saving effect.

Note that the angle portion 9 of the conveyor frame 3 includes guide rails 10A and 10B, which the hanger support roller 11 contacts, and a rail C, which the collector 7 slides into contact with.
A horizontal receiving tray 19 is attached to catch dirt etc. falling from the surface of the shaped steel 6, and a conveyor flail 3 is also attached to the vertical part 3c of the conveyor frame 3.
A tray 20 is attached to catch lubricating oil, dirt, etc. that fall from the tank.

The above is an example of the structure of the electrodeposition coating apparatus according to the present invention, and the operation and effect thereof will be explained next.

According to this example, when the automobile body W carried on the horizontal portion 2b of the L-shaped hanger 2 is placed in the electrodeposition bath 1, hanger supports attached to both the upper and lower ends of the L-shaped hanger 2 are used. Rollers 11 and 14
are in contact with the guide rails 10A and 13A provided on the entry side of the electrodeposition bath 1, respectively, to keep the automobile body W in a horizontal state. Accidents of falling from the horizontal portion 2b of the L-shaped hanger 2 when submerged in the paint can be reliably prevented.

The automobile body W, which is immersed in the electrodeposition tank 1 in this state, is connected to the diaphragm electrodes 8R, 8L and the auxiliary electrode 15 in the electrodeposition tank 1 through the L-shaped hanger 2 with a polarity different from that of the diaphragm electrodes 8R, 8L and the auxiliary electrode 15. Diaphragm electrode 8R, 8L
A current flows between the auxiliary electrode 15 and the automobile body W, and an electrodeposited coating film is formed on the surface of the automobile body W.

At this time, the section between the guide rails 13A and 13B that supports the lower end side of the L-shaped hanger 2 is omitted.
During this period, there is no obstacle that can block the current flowing between the automobile body W immersed in the electrodeposition bath 1 and the diaphragm electrode 8L installed along the side wall 4L inside the electrodeposition bath 1. The throwing power of the electrodeposition paint on the surface of the body W is not impaired.

Further, the L-shaped hanger 2 passing through the omitted part between the guide rails 13A and 13B is moved at a certain angle in the direction of the side wall 4L of the electrodeposition tank 1 with the upper end side of the vertical part 2a as a fulcrum, as shown by the chain line in FIG. Rotate and
Since the automobile body W placed on the horizontal portion 2b of the L-shaped hanger 2 is automatically tilted, the air inside the body W is removed, and defective electrodeposition due to adhesion of air bubbles is reliably prevented.

Furthermore, the guide rails 13A and 13B, which are provided on the entry and exit sides of the tank by omitting the intermediate part, are easy to maintain and inspect, and also prevent the flow of electrocoating paint occurring in the electrodeposition tank 1. There is no risk of interference.

The automobile body W on which the electrocoated film has been formed in the electrodeposition bath 1 is attached to a guide rail 10B on which the hanger support rollers 11 and 14 of the L-shaped hanger 2 on which the body W is placed is provided on the exit side of the bath. By contacting 13B, it is returned to the horizontal state again,
In this state, it is lifted out of the electrodeposition paint in the electrodeposition tank 1.

Therefore, an accident in which the automobile body W placed on the horizontal portion 2b of the L-shaped hanger 2 falls into the tank is reliably prevented.

In the embodiment, an auxiliary electrode 15 facing the upper surface of the car body W is interposed between the car body W and the side wall 4L of the electrodeposition tank 1, and is installed in the space above the electrodeposition tank 1. Since it is provided on the conveyor frame 3, it does not get in the way when performing maintenance inspection or replacement of the diaphragm electrodes 8R, 8L provided in the electrodeposition tank 1, and at the same time, When the submerged automobile body W is tilted together with the L-shaped hanger 2 to vent air, there is no fear that the auxiliary electrode 15 will be damaged by a collision of the automobile body W.

Further, the L-shaped hanger 2 is not provided with the auxiliary electrode 15, and the conveyor C provided with the L-shaped hanger 2 has no member located directly above the automobile body W placed on the hanger 2. Because it does not exist, the automobile body W transported from the electrodeposition bath 1
Drops of electrodeposited paint liquid will not fall on the upper surface of the conveyor C, and lubricating oil and dust adhering to the conveyor C will not fall, resulting in poor coating.

Furthermore, if the auxiliary electrode 15 is not provided on the L-shaped hanger 2 but provided on the conveyor frame 3 installed in the space above the electrodeposition bath 1, the L-shaped hanger 2 can be used in the pretreatment process. However, there is no risk of droplets of pre-treatment liquid dripping onto the top surface of the automobile body W and causing stains that may cause paint film defects. There is no need to change hangers.

Further, a conveyor rail 5 for suspending the L-shaped hanger 2 and a guide rail 10A for guiding the hanger support roller 11 attached to the L-shaped hanger 2 are provided.
, 10B, auxiliary electrode 15, etc. are all provided on the conveyor frame 3, so conveyor frames 3 having this configuration can be uniformly mass-produced to reduce manufacturing costs, and the entire electrodeposition coating apparatus can be It is also possible to significantly reduce equipment costs.

In addition, in order to hang the L-shaped hanger 2 on the conveyor rail 5 in an appropriate state, the conveyor rail 5
The guide rails 10A and 10B, which are in contact with the hanger support roller 11 attached to the L-shaped hanger 2, must be aligned accurately. 10B on the conveyor frame 3, alignment becomes extremely easy.

That is, the guide rails 10A and 10B that guide the hanger support roller 11 are temporarily placed in the electrodeposition tank 1.
If the guide rails 10A and 10B and the conveyor rail 5 are fixedly provided on the side wall 4L, it becomes very difficult to align the guide rails 10A and 10B and the conveyor rail 5 with respect to each other. In addition, in this case, the guide rail fixed to the side wall 4L becomes an obstacle, which impedes the maintenance, inspection and replacement work of the diaphragm electrode 8L. On the other hand, as described above, the conveyor rail 5 and the guide rail 10A
and 10B are provided on the conveyor frame 3,
It becomes easy to align the two, and there is no problem when performing maintenance, inspection, or replacement of the diaphragm electrode 8L.

[Effect of idea]

As described above, according to the present invention, when the object to be coated placed on the L-shaped hanger is submerged in the electrodeposition paint in the electrodeposition tank, and when it is taken out from the electrodeposition paint, the L Since the hanger support roller of the shaped hanger comes into contact with the guide rail and keeps the object to be coated in a horizontal state, accidents of falling of the object to be coated are reliably prevented.

In addition, the guide rail that abuts the hanger support roller attached to the lower end of the L-shaped hanger is
Since they are installed on the inlet and outlet sides of the tank, and the intermediate part is omitted, the object to be coated placed on the L-shaped hanger automatically tilts in the electrodeposition tank to remove air, preventing air bubbles from adhering to the tank. In addition to reliably preventing electrodeposition defects, the guide rail can also block the current flowing between the electrode installed in the electrodeposition bath and the object to be coated that is connected to a different polarity from the electrode. Therefore, there is no fear that the coverage of the electrodeposition paint on the surface of the object to be coated will be impaired.

In addition, the guide rails installed on the entry and exit sides of the tank by omitting the middle part are extremely easy to maintain and inspect, and at the same time, they eliminate the need for the inside of the electrodeposition tank, which is created to stir the paint components. It has various excellent effects such as being less likely to interfere with the flow of the electrodeposition paint.

[Brief explanation of drawings]

FIG. 1 is a schematic view showing an example of an electrodeposition coating apparatus according to the present invention, and FIG. 2 is a view taken along the - line. Explanation of symbols, W...Automobile body (subject to be coated),
C... Conveyor, 1... Electroplating tank, 2... L-shaped hanger, 13A... Guide rail on the tank side, 13B
... Guide rail on the outlet side, 14 ... Hanger support roller.

Claims (1)

[Scope of utility model registration request] The hanger of the conveyor on which the object to be coated is placed and immersed in the electrodeposition tank is formed in an L shape, and the object to be coated placed on the L-shaped hanger is brought into contact with a hanger support roller attached to the lower end side. An electrodeposition coating apparatus characterized in that guide rails for keeping objects in a horizontal state are provided on the entry side and the exit side of the electrodeposition tank, omitting the intermediate part.