JP2988241B2 - Electrocoating equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrodeposition coating apparatus, and is particularly useful when applied to a body of a so-called high roof vehicle having a large vertical dimension such as a one-box type commercial vehicle van. .

[0002]

2. Description of the Related Art In a coating process for coating a body of an automobile, there is a process of performing electrodeposition coating using an electrodeposition coating apparatus.
FIG. 5 is an explanatory view showing a configuration of an electrodeposition coating apparatus for an automobile body according to the related art, and FIG. 6 is a cross-sectional view taken along line CC of FIG.

In both figures, 13a is a body for a high-roof vehicle,
13b is a body of a normal car having a smaller vertical dimension than a high-roof car (hereinafter simply referred to as a body for a normal car), 14b.
Is an electrodeposition paint, 15 is an electrodeposition tank, 16a and 16b are conveyor hangers, 17 is a side electrode, 18 is a lower electrode, 19 is a conveyor, and 20 is a power supply.

An electrodeposition paint 15 is stored in an electrodeposition tank 15. The level of the electrodeposition paint 14 is controlled to a required value by overflowing from an overflow section (not shown).

Further, in the electrodeposition bath 15, a side electrode 17 and a lower electrode 18 in the form of a flat plate are provided. Side electrode 17
Is a high-roof vehicle body 13 indicated by an arrow A in FIG.
A plurality of electrodeposition tanks 15 are provided side by side on the left and right side surfaces 15a, 15b in FIG. 6 so as to have a predetermined distance from each other along the transport direction of the vehicle body 13a and the body 13b for a normal vehicle (hereinafter simply referred to as the transport direction). The lower electrode 18 is an auxiliary electrode for additionally generating a coating film, and is provided on the bottom surface 18 on the downstream side in the transport direction from the side electrode 17. Accordingly, the side electrode 17 and the lower electrode 18 are respectively connected to the body 13a for a high-roof vehicle and the body 1
It occupies both sides and below 3b.

The conveyor hangers 16a and 16b are substantially C-shaped members. The lower ends of the conveyor hangers 16a and 16b support the lower front and rear lower ends of the body 13a for a high-roof vehicle and the body 13b for a normal vehicle, respectively. Each is supported. The conveyor 19 is installed above the electrodeposition tank 15 so as to extend along the longitudinal direction of the electrodeposition tank 15, and while transporting the body 13a for a high-roof vehicle and the body 13b for a normal vehicle together with the conveyor hangers 16a and 16b, During the transportation, these bodies 13a and 13b are carried into the electrodeposition tank 15 from the front end (the right end in FIG. 1) of the electrodeposition tank 15, which is on the upstream side in the transport direction, and are moved through the electrodeposition paint 14 by a certain length. Then, it is pulled up from the rear end (left end in FIG. 1) of the electrodeposition tank 15a, which is on the downstream side in the transport direction, to above the electrodeposition tank 15.

The power supply 20 includes a side electrode 17 and a lower electrode 1.
8, a negative voltage is applied to the body 13a for a high-roof vehicle and the body 13b for a normal vehicle via a conveyor 19 and conveyor hangers 16a, 16b.

Therefore, according to the electrodeposition coating apparatus having the above structure,
While the body 13a for high-roof vehicles and the body 13b for ordinary vehicles are conveyed by the conveyer 19 and move in the electrodeposition paint 14a for a certain length, a coating film is formed on these bodies 13a and 13b at the side electrode 17 portion. Further, when there is a thin portion of the coating film at the lower ends of the bodies 13a and 13b, a coating film is additionally generated at the lower electrode 18 portion.

A similar apparatus to the above-mentioned electrodeposition coating apparatus is disclosed in Japanese Utility Model Laid-Open No. 1-74272 and Japanese Patent Application Laid-Open No. 60-96895.

[0010]

However, in the above electrodeposition coating apparatus according to the prior art, the body 1 for a high-roof vehicle is required.
When electrodeposition 3a is applied by electrodeposition, the liquid depth d ₁ (the distance from the center 13a 'of the roof to the liquid level 14a of the electrodeposition paint 14) at the center 13a' of the roof is the center 13b 'of the roof of the body 13b for a normal vehicle. Is smaller than the liquid depth d ₂ (the distance from the roof center 13b 'to the liquid surface 14a), and the distance from the side electrode 17 to the roof center 13a' is smaller than the side electrode 17 to the roof center 13b '. Therefore, the efficiency of forming a coating film at the roof central portion 13a 'is low.

Therefore, an adjustment (a rise in the temperature of the electrodeposition paint 14 or an increase in the applied voltage) is performed at the roof central portion 13a 'to secure the required film thickness. However, if the required film thickness of the roof central portion 13a 'is to be ensured by such an adjustment, the coating film is unnecessarily increased in portions other than the roof central portion 13a'. In some cases, this loss is large), and further, there is a problem in terms of quality that gas pins are generated in the portion.

In view of the above prior art, the present invention is also applicable to a case where an object to be coated having a large vertical dimension, such as a body for a high roof vehicle, is electrodeposited. An object of the present invention is to provide an electrodeposition coating apparatus capable of securing a required film thickness at a central portion of an upper end without adversely affecting portions other than the above.

[0013]

According to a first aspect of the present invention, which achieves the above object, an electrodeposition tank for storing an electrodeposition coating material and an object to be coated are formed in a substantially C shape and one of them is open. Transport means suspended by the conveyed conveyor hanger and transported along the transport path, loaded into the electrodeposition tank during transport, moved through the electrodeposition paint for a certain length, and then pulled up; and A plurality of side electrodes arranged in the electrodeposition paint at predetermined intervals along the transport path so as to occupy the side of the article to be moved in the paint, and the inside of the electrodeposition paint. An upper electrode supported by a float floating on the liquid surface so as to occupy the upper central part of the moving object to be coated and below the liquid surface of the electrodeposition coating material, and supports the upper electrode. At the same time, horizontal movement is achieved by support means provided on the open side of the conveyor hanger. A float is braking is and vertically movably supported, and having a power source for applying a voltage between said side electrode and the upper electrode coating object.

According to a second aspect of the present invention which achieves the above object, an electrodeposition tank for storing an electrodeposition coating material and an object to be coated are hung by a conveyor hanger which is formed in a substantially C shape and one of which is open. While being transported along the transport path, the transport means is carried into the electrodeposition tank during transport, moved up in the electrodeposition paint for a certain length, and then pulled up, and the transport means moving in the electrodeposition paint. A plurality of side electrodes provided in the electrodeposition paint at predetermined intervals along the transport path so as to occupy the side of the object, and the object moving in the electrodeposition paint So as to occupy the lower part of the electrodeposition paint, the lower electrode disposed in the electrodeposition paint, the upper end central part of the object to be moved moving in the electrodeposition paint, and the liquid level of the electrodeposition paint. The upper electrode supported by the float floating on the liquid surface and the upper electrode are supported so that In addition, horizontal movement is suppressed by the support means provided on the open side of the conveyor hanger, and the float supported movably up and down, and between the side electrode, the lower electrode, the upper electrode, and the object to be coated. And a power supply for applying a voltage to the power supply.

According to a third aspect of the present invention that achieves the above object, in the above first or second aspect, the upper electrode comprises:
It is characterized in that it is arranged downstream of the side electrode in the conveying direction of the object to be coated.

According to a fourth aspect of the present invention, which achieves the above object, there is provided a dust receptacle supported by a float so as to occupy below the upper electrode in the first, second or third aspect. It is characterized by the following.

[0017]

According to the first aspect of the present invention, even when the object to be coated passes below the upper electrode even at the center of the upper end of the object having a large vertical dimension such as a body for a high-roof vehicle. In addition, a coating film having a required film thickness is surely generated. During this time,
In portions other than the upper end center portion, since this portion is farther from the upper electrode than the upper end center portion, the coating film generated by the upper electrode is small. Also, since the upper electrode is supported by the float and does not move in the horizontal direction, and even if the liquid level of the electrodeposition paint changes, it moves up and down with the float in response to this, so that the upper electrode There is no risk of exposure on the liquid surface.

According to the second configuration of the present invention, in addition to the same operation as in the first configuration, the object to be coated also passes above the lower electrode with respect to the lower end of the object. In the meantime, a coating of the required thin film is reliably produced.

According to the third configuration of the present invention, in addition to the same operation as the first or second configuration, when an object having a large vertical dimension passes below the upper electrode, the upper end of the object is positioned at the center of the upper electrode. The portion other than the portion is farther from the upper electrode than the central portion at the upper end as described above, and a sufficient coating film (required film thickness) has already been generated on the side electrode portion. Since the resistance is increased, no additional coating film is generated, and the film thickness is maintained at the required thickness.

According to the fourth configuration of the present invention, in addition to the same operation as the first, second, or third configuration, paint dust generated on the upper electrode is peeled off by the dust receiver to be coated. Prevents sticking to the top of objects.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings. The same parts as those in the related art are denoted by the same reference numerals, and redundant description will be omitted.

FIG. 1 is an explanatory view showing the structure of an electrodeposition coating apparatus according to an embodiment of the present invention, FIG. 2 is a sectional view taken along the line AA of FIG. 1, and FIG. Perspective view showing details,
FIG. 4 is a sectional view taken along line BB of FIG.

As shown in these figures, the electrodeposition coating apparatus according to the present embodiment has the same structure as the above-mentioned prior art electrodeposition coating apparatus (see FIGS. 5 and 6), and has an upper electrode 1 and a dust receptacle. 2, 11, safety chains 3a, 3b, support members 4a, 4
b, 12, float 5, supporting parts 6a, 6b, 7a, 7
b, 9a, 9b, 9c, 9d, arms 8a, 8b, and a cable 10.

The upper electrode 1 is located at a predetermined position, that is, as shown in FIGS. 1 and 2, at the center of the roof of the high-roof vehicle body 13a moving in the electrodeposition paint 14 at the downstream side in the transport direction from the side electrode 17. 13a 'above and electrodeposition paint 1
This liquid level 1 is occupied below the liquid level 14a of
It is supported by a float 5 floating on 4a.

More specifically, as shown in FIGS. 3 and 4, the float 5 is formed by forming a rigid PVC pipe into a substantially rectangular shape, and has a space 5a on the inner side. The upper electrode 1 is provided on 5a. That is, the cylindrical upper electrode 1 has rod-shaped support members 4a, 4a whose both ends are fixed inside the float 5 so that the longitudinal direction thereof extends along the longitudinal direction of the float 5 and occupies the center of the space portion 5.
It is supported by the float 5 via b. Accordingly, when the float 5 moves up and down in accordance with a change in the level of the electrodeposition coating material 14, the upper electrode 1 moves up and down. As the upper electrode 1, a bare electrode made of copper is usually used.

The dust receiver 2 is a semi-cylindrical member made of hard polyvinyl chloride, and its both ends are supported below the upper electrode 1 so as to surround the lower half of the upper electrode 1.
a, 4b, respectively, and paint scum generated on the upper electrode 1 is peeled off and the roof central portions 13a ', 13b'
To prevent it from adhering to

Each of the arms 8a and 8b is a V-shaped member, and each of its base ends is connected to a supporting portion 9a to 9d provided at a predetermined interval on the upper end of one side surface 15a of the electrodeposition tank 15. Each of the end portions is rotatably supported, and each end is fixed to support portions 7a and 7b provided at both ends in the longitudinal direction of the float 5, respectively. That is, the arms 8a and 8b hold the float 5 so that the longitudinal direction of the float 5 is along the transport direction, and suppress the float 5 from moving in the horizontal direction, while preventing the liquid level of the electrodeposition paint 14 from changing. With this vertical movement, the float 5 rotates about the base end so as not to hinder the vertical movement of the float 5. Note that such arms 8a,
8b can be provided to hold the float 5
This is because the conveyor hangers 16a and 16b are formed in a substantially C shape as described above. That is, the right side of the conveyor hangers 16a and 16b in FIG. 2 is open, and by providing the arms 8a and 8b on the open side, the arms 8
This is because a and 8b can be prevented from becoming an obstacle to conveyance.

The safety chains 3a and 3b have supporting portions 6a and 6b each having a lower end provided at both ends in the longitudinal direction of the float 5.
The upper end is fixed to the bottom of the refuse receptacle 11, respectively, and when the liquid level of the electrodeposition paint 14 is greatly reduced, such as when the electrodeposition paint 14 is replaced with a new one, the float 5 Prevents falling. Note that these safety chains 3a and 3b have such a slack that the vertical movement of the float 5 due to the normal change of the liquid level (change of the control range) cannot be prevented.

The garbage tray 11 includes the float 5 and the conveyor 1
9 is supported by the lower end of an L-shaped support member 12 whose upper end is supported by a ceiling structure (not shown) so as to cover the entire float 5 in the middle of the float 5 and hangs down from the conveyor 19. Grease or the like is prevented from adhering to the upper electrode 1.

The cable 10 is a cable connecting the upper electrode 1 and the power supply 20, and the power supply 2 is connected through the cable 10.
From 0, a positive voltage is applied to the upper electrode 1.

Therefore, according to the above-mentioned electrodeposition coating apparatus, as shown in FIG.
When occupying the lower part of the upper electrode 1 after passing through the portion, a coating film is additionally generated at the roof central portion 13a '. As a result, the required film thickness of the roof central portion 13a 'is secured.

In addition, at this time, the body 13 for a high-roof vehicle is used.
In the portion a except for the roof central portion 13a ', a sufficient coating film (required film thickness) has already been formed at the side electrode 17 portion, and this coating film has increased electric resistance and Since it is farther from the upper electrode 1 than the central portion 13a ', no additional coating film is generated.

Therefore, there is no fear that the film thickness of the portion concerned is increased more than necessary and a large loss in cost is caused, and there is no possibility of causing a quality defect such as generation of gas pins in the portion, and the quality is high. Electrodeposition coating can be performed efficiently.

In a state where a voltage is applied to the upper electrode 1,
Even if the ordinary vehicle body 13b occupies below the upper electrode 1, at this time, the parts other than the roof central part 13b 'in the side electrode 17 are, of course, the roof central part 13b.
A sufficient coating film (required film thickness) is formed also on b ′, and the electric resistance is increased by these coating films, and these portions are formed on the central portion 13a ′ of the roof of the high roof vehicle body 13a. In comparison, since it is far away from the upper electrode 1, there is no possibility that a coating film is additionally formed on these portions, and no particular problem occurs. Therefore, a voltage may always be applied to the upper electrode 1 regardless of the type of the body.

The upper electrode 1 is supported by the float 5 and moves up and down with the float 5 in accordance with a change in the liquid level of the electrodeposition coating material 14. Therefore, there is no possibility that the upper electrode 1 will be exposed on the liquid surface 14a. There is no risk of being adversely affected.

Further, since the trash receptacles 2 and 11 are provided,
It is possible to prevent paint residue generated on the upper electrode 1 from peeling off and adhering to the roof central portions 13a 'and 13b', thereby preventing deterioration in quality and preventing the conveyor 1 from being damaged.
By preventing grease or the like dripping from the upper electrode 9 from adhering to the upper electrode 1, it is possible to prevent performance degradation.

Further, since the material of the float 5 and the waste receiver 2 is hard polyvinyl chloride, the body 1
Even if the roof 3a or the like accidentally contacts the float 5 or the dust receptacle 2, there is no possibility that a spark will occur between the roof 3a and the upper electrode.

Since the upper electrode 1 can be viewed from above, the management of the upper electrode 1 is easy.

Also, as in the above embodiment, the side electrode 17
Although it is desirable to dispose the upper electrode 1 and the lower electrode 18 on the downstream side in the transport direction, the present invention is not limited to this, and these may be disposed at the same position as the side electrode 17 or in the transport direction relative to the side electrode 17. It may be arranged on the upstream side.

In this case, an ON / OFF control means is interposed between the upper electrode 1 and the lower electrode 18 and the power supply 20, and a body 13a for a high-roof vehicle or the like is formed in order to prevent an unnecessary coating film from being formed. Upper electrode 1 according to the height of the body
It is desirable to control ON / OFF of the current supply to the lower electrode 18. For example, when the body 13a for a high-roof vehicle is electrodeposited, the power supply to the upper electrode 1 is turned ON, and when the body 13b for a normal vehicle is electrodeposited, the power supply to the upper electrode 1 is turned OFF. I do.

Further, a detecting means for detecting the height of the body before the body is carried into the electrodeposition paint 14 is provided, and after detecting the height of the body by the detecting means, The ON / OFF control means is turned ON after a predetermined time when the body reaches just before the upper electrode 1 and the lower electrode 18.
-It may be automated to perform the OFF control.

[0042]

According to the present invention, as described above in detail with the embodiment, even if the object to be coated has a large vertical dimension, such as a high-roof vehicle, the upper electrode is provided with the upper electrode. Required film thickness can be surely secured.
For this reason, high quality electrodeposition coating can be performed efficiently regardless of the size of the object to be coated. Further, since the upper electrode is supported by the float, it is possible to prevent the upper electrode from moving in the horizontal direction and to prevent the upper electrode from being exposed on the liquid surface of the electrodeposition paint and adversely affecting it.

Further, the provision of the lower electrode makes it possible to reliably secure a necessary thin film also at the lower end of the object to be coated.

Further, by disposing the upper electrode on the downstream side of the side electrode in the transport direction, it is possible to reliably prevent the formation of a coating film having a thickness smaller than a required thin film on a portion other than the central portion of the upper end of the object to be coated. And there is no cost loss.

Further, the provision of the dust receptacle prevents the paint residue generated on the upper electrode from peeling off and adhering to the upper end of the object to be coated, thereby preventing deterioration in quality.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a configuration of an electrodeposition coating apparatus according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a perspective view showing details of an upper electrode and the like shown in FIG. 1;

FIG. 4 is a sectional view taken along line BB of FIG. 3;

FIG. 5 is an explanatory view showing a configuration of an electrodeposition coating apparatus according to a conventional technique.

6 is a sectional view taken along line CC of FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Upper electrode 2, 11 Garbage receiver 3a, 3b Safety chain 4a, 4b, 12 Support member 5 Float 8 Arm 10 Cable 13a Body for high roof car 13b Body for normal car 14 Electrodeposition paint 14a Liquid level 15 Electrodeposition tank 15a, 15b Side 16a, 16b Conveyor hanger 17 Side electrode 18 Lower electrode 19 Conveyor 20 Power supply

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁶ , DB name) C25D 13/22 C25D 13/00 305

Claims (4)

(57) [Claims] 1. An electrodeposition tank for storing an electrodeposition coating material, and an object to be coated are transported while being transported along a transport path while being hung by a conveyor hanger having a substantially C-shape and having one open side. Conveying means which is carried into the electrodeposition tank and moved up in the electrodeposition paint for a predetermined length and then pulled up, so that the object to be moved in the electrodeposition paint occupies a side of the object to be coated. A plurality of side electrodes disposed in the electrodeposition paint at predetermined intervals along the transport path; and above an upper center portion of an upper end of the object to be moved in the electrodeposition paint, and the electrodeposition paint An upper electrode supported by a float floating on the liquid surface so as to occupy a lower position than the liquid surface of the liquid, and the horizontal movement is supported by a supporting means provided on the open side of the conveyor hanger while supporting the upper electrode. A float supported so as to be restrained and movable up and down, Wherein the parts and upper electrodes electrodeposition coating apparatus characterized by having a power source for applying a voltage between the article to be coated. 2. An electrodeposition tank for storing an electrodeposition coating material, and an object to be coated are transported while being transported along a transport path while being hung by a conveyor hanger formed in a substantially C shape and having one open side. Conveying means which is carried into the electrodeposition tank and moved up in the electrodeposition paint for a predetermined length and then pulled up, so that the object to be moved in the electrodeposition paint occupies a side of the object to be coated. A plurality of side electrodes arranged in the electrodeposition paint at predetermined intervals along the transport path; and the electrodeposition paint occupying below the object to be moved moving in the electrodeposition paint. A lower electrode disposed therein, above the center of the upper end of the workpiece to be moved in the electrodeposition paint, and occupied below the liquid level of the electrodeposition paint, so as to occupy this liquid level. An upper electrode supported by a floating float, and supporting the upper electrode, A float, which is horizontally supported by the support means provided on the discharge side and supported so as to be movable up and down, and a power supply for applying a voltage between the side electrode, the lower electrode and the upper electrode, and the object to be coated. An electrodeposition coating apparatus comprising: 3. The electrodeposition coating apparatus according to claim 1, wherein the upper electrode is disposed downstream of the side electrode in the conveying direction of the object to be coated. apparatus. 4. The electrodeposition coating apparatus according to claim 1, further comprising a dust receiver supported by a float so as to occupy below the upper electrode. .