JP2002069697A - Electrophoretic coating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophoretic coating apparatus with a simple structure, which can carry out an electrophoretic coating with constant film thickness even if the size of an article to be coated is changed. SOLUTION: This electrophoretic coating apparatus comprises a plurality of electrodes 17 provided respectively at both sides in an electrophoresis cell 3, so as to be able to move in a widthwise direction of each vehicle body 4 according to its size. When a big vehicle body 4 is electrophoretically coated, the electrodes 17 at the both sides are moved outwards in the widthwise direction of the vehicle body 4. On the other hand, when a small size vehicle body 4 is electrophoretically coated, electrodes 17 at the both sides are moved inwards in the widthwise direction of the vehicle body 14. Thus, a distance between electrodes 17 respectively the both sides and each vehicle body 4 can be always set constant regardless of the size of vehicle body 4, and the electrophoretic coating with the constant film thickness can be carried out, even if the size of the vehicle body 4 sequentially transported is changed.

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 for immersing an object to be coated in an electrodeposition tank while being conveyed by a conveying means to perform electrodeposition coating.

[0002]

2. Description of the Related Art Conventionally, an electrodeposition coating apparatus for suspending an object to be coated such as a vehicle body on a hanger and sequentially immersing the object in an electrodeposition solution in an electrodeposition tank by transporting a conveyor. It has been known.

[0003] In such an electrodeposition coating apparatus, usually, a power supply rail is disposed above the electrodeposition tank along the conveying direction of the conveyor, and each hanger is connected to the power supply rail and the inside of the electrodeposition tank is provided. On both sides of the object to be coated, a plurality of electrodes are arranged at predetermined intervals in the conveying direction of the conveyor, and a negative voltage is applied to the object to be coated from a power supply via a power supply rail and a hanger. At the same time, a positive voltage is applied to the electrodes, whereby the object to be coated is electrodeposited.

[0004] In such an electrodeposition coating apparatus, the thickness of the coating film to be electrodeposited varies depending on the distance between the electrode and the surface of the object to be coated. In the gazette, in an electrodeposition tank, an insulating shield is vertically slidably attached to each of column-shaped electrodes disposed on both sides of the object to be coated, and the object to be coated is According to the shape of, for example, in a portion where the facing distance between the electrode and the surface to be coated of the object to be coated is shorter, the shield is slid at a low speed to increase the shielding time, and
In areas where the facing distance between the electrode and the surface to be coated is longer, the shield is slid at high speed to shorten the shielding time, so that the film thickness over the entire surface to be coated is made uniform. It has been proposed to.

[0005]

SUMMARY OF THE INVENTION However, Japanese Patent Application Laid-Open No. 7-1
In the method described in Japanese Patent No. 50392, when each object to be coated has a portion where the distance to the surface to be coated with respect to the electrode has a long portion and a short portion, the electrodeposition coating is performed with a uniform film thickness. However, for example, when the size of the entire object to be coated is changed, for example, when a plurality of vehicle models having different sizes are subjected to electrodeposition coating on one line, an optimum Electrodeposition cannot be applied to a coating film. In addition, in order to correspond to the relative distance between the electrode and the surface to be coated, the shield is speed-modulated and slid, so that the control is complicated, and the cost is increased due to the complicated device configuration. .

The present invention has been made in view of such circumstances, and its object is to provide a simple configuration.
An object of the present invention is to provide an electrodeposition coating apparatus capable of performing electrodeposition coating with a constant film thickness even when the size of an object to be coated is changed.

[0007]

In order to achieve the above object, the present invention provides an electrodeposition tank in which an electrodeposition liquid is stored, and an object to be coated which is immersed in the electrodeposition tank for a predetermined distance. In an electrodeposition coating apparatus including a transport unit for sequentially transporting the plurality of objects to be coated, and a plurality of electrodes provided to face the object to be coated in the electrodeposition tank, It is characterized in that it is provided so as to be movable in a direction facing the object to be coated according to the size of the object to be coated.

According to such a configuration, for example, when an object to be coated having a large size is subjected to electrodeposition coating, the electrode is moved in a direction farther from the object to be coated, while an electrode having a small size is coated. In the case of electrodeposition coating an object, if the electrode is moved in a direction closer to the object to be coated, the distance between the electrode and each object to be coated is predetermined regardless of the size of the object to be coated. Can be set to the distance. Therefore, even if the size of each coated object is changed in the sequentially transferred coated objects,
If the electrodes are moved according to the size, electrodeposition coating with a constant film thickness can be performed. Moreover, such an electrodeposition coating apparatus according to the present invention can be realized simply and at low cost because the electrode itself is only moved in the direction facing the object to be coated.

In the electrodeposition coating apparatus of the present invention,
It is preferable that the electrode is provided on a side of the object to be coated, and is provided so as to be movable in a width direction of the object to be coated.

According to such a configuration, if the electrodes provided on the sides are moved in the width direction in accordance with the size of each object to be coated, the electrodes and each object to be coated can be easily and reliably connected. The distance between them can be set to a predetermined distance. Therefore, electrodeposition coating with a uniform film thickness can be performed more simply and at lower cost.

Further, in the electrodeposition coating apparatus according to the present invention, the driving means for moving the electrode, the size detecting means for detecting the size of the object to be coated, and the driving means in the conveying direction of the conveying means. A position detecting unit for detecting a position of the object to be coated, wherein the driving unit moves the electrode in a direction facing the object to be coated based on a detection signal from the size detecting unit and the position detecting unit. It is preferable to be constituted so that it may be moved.

According to such a configuration, if the size detecting means detects the size of the object to be coated and the position detecting means detects the position of the object to be coated, the object to be coated is detected based on the detection signals. When facing the electrode, the driving means can move the electrode to a predetermined position according to the size of the object to be coated. Therefore, the electrode can always be reliably moved to an appropriate position according to the size of each object to be coated, and electrodeposition coating with a constant film thickness can be performed with better accuracy.

[0013]

FIG. 1 is a sectional side view showing a main part of an embodiment of an electrodeposition coating apparatus according to the present invention, and FIG. 2 is a front sectional view thereof. Hereinafter, this electrodeposition coating apparatus will be described with reference to FIGS. In FIG. 1, an electrodeposition coating apparatus 1 includes an electrodeposition tank 3 in which an electrodeposition liquid 2 is stored,
A transport unit 5 as transport means for sequentially transporting a vehicle body 4 as an object to be coated while immersing the vehicle body 4 at a fixed distance, and an electrodeposition unit for electrodepositing the vehicle body 4 in the electrodeposition tank 3 6 is provided.

The electrodeposition tank 3 has a bottom wall 7 as shown in FIG.
And two side walls 8 standing opposite to each other from both side ends of the bottom wall 7. As shown in FIG. Has an outlet-side portion 11 inclined upward, and a flat central portion 12 between the inlet-side portion 10 and the outlet-side portion 11.
In addition, in the electrodeposition tank 3, the vehicle body 4 is formed along the longitudinal direction thereof in such a size that approximately 4 to 6 vehicle bodies 4 can be immersed.

As shown in FIG. 1, the transport unit 5 includes a conveyor 13 disposed above the electrodeposition tank 3 and in parallel with the bottom wall 7 along the longitudinal direction of the electrodeposition tank 3, and a conveyor 13. 13 and a plurality of hangers 14 suspended at a predetermined pitch. As shown in FIG. 2, each hanger 14 includes a holder 15 for holding the vehicle body 4 in a sandwiched manner from the bottom surface.

Then, as shown in FIG. 1, each vehicle body 4 is held in a holder 15 of each hanger 14,
By driving the conveyor 13, the inlet side portion 10 of the electrodeposition tank 3
After being immersed in the electrodeposition liquid 2 in the central portion 12, it is sequentially discharged from the outlet side portion 11.

The electrodeposition unit 6 is shown in FIGS.
As shown in FIG. 2, a power supply rail 16 disposed along the conveyor 13, a side electrode 17 and a bottom electrode 18 provided in the electrodeposition tank 3, and the power supply rail 16, the side electrode 1
7 and a power supply 19 connected to the bottom electrode 18. The power supply rail 16 is connected to each hanger 14 and to the cathode 20 of the power supply 19.

A plurality of side electrodes 17 are provided at predetermined intervals along the longitudinal direction of the electrodeposition tank 3.
The vehicle body 4 is disposed so as to face the vehicle body 4 on both sides. Also, the bottom electrode 1
Similarly, a plurality of reference numerals 8 are provided at predetermined intervals along the longitudinal direction of the electrodeposition tank 3, and are arranged so as to face the vehicle body 4 in the electrodeposition tank 3 below. The side electrode 17 and the bottom electrode 18 are connected to the power source 1.
9 are connected to the anode 21.

A negative voltage is applied to each vehicle body 4 from the cathode 20 of the power supply 19 via the power supply rail 16 and each hanger 14, and from the anode 21 of the power supply 19 to each side electrode 17 and each bottom part. When a positive voltage is applied to the electrode 18, the paint in the electrodeposition liquid 2 is charged and adheres to the surface to be coated of each vehicle body 4 to form a coating film. Is performed.

In the electrodeposition coating apparatus 1, each side electrode 17 is provided so as to be movable in the width direction of each vehicle body 4 according to the size of each vehicle body 4. That is, as shown in FIG. 1 and FIG.
Near each side electrode 1 in the longitudinal direction of the electrodeposition tank 3.
Cylinders 22 as driving means are provided at positions opposed to 7, respectively, and the upper end of each side electrode 17 is attached to a cylinder rod 23 which is inserted into each cylinder 22 so as to be able to move forward and backward. Therefore, the side electrode 17 is moved in the width direction with respect to the vehicle body 4 within the range of the stroke length in which the cylinder rod 23 advances and retreats. Therefore, for example, as shown by the solid line in FIG. 3, when a large vehicle body 4 is electrodeposited, each side electrode 17 is moved outward in the width direction with respect to the vehicle body 4. As shown by the imaginary line in FIG.
When electrodepositing a small vehicle body 4,
If each side electrode 17 is moved inward in the width direction with respect to the vehicle body 4, the distance between the side electrode 17 and each vehicle body 4 is always electrodeposited regardless of the size of the vehicle body 4. The optimum distance for painting can be set. Therefore, even when the size of each vehicle body 4 is changed in the sequentially transported vehicle bodies 4, it is possible to perform electrodeposition coating with a constant film thickness. Moreover, the electrodeposition coating apparatus 1 is realized at low cost by a simple configuration in which the side electrode 17 itself is only moved in the width direction of the vehicle body 4.

The cylinder 22 is driven continuously, and is configured so that the cylinder rod 23 can be advanced and retracted at an arbitrary position within the range of the stroke length of the cylinder rod 23. Therefore, regardless of the size of the vehicle body 4, each side electrode 17 is located at an optimum position corresponding to the vehicle body 4.
It is configured so that can be arranged.

As shown in FIG. 1, the electrodeposition coating apparatus 1 is further provided with a vehicle width detection sensor 24 as size detection means and a position sensor 25 as position detection means. By the vehicle width detection sensor 24,
When the vehicle width of the vehicle body 4 is detected and the position sensor 25 detects that the vehicle body 4 has passed a predetermined position, the detection signals are transmitted to a CPU (not shown), At a predetermined timing based on the detection signal by the CPU, the vehicle body 4
The piston rod 23 is driven so as to correspond to the vehicle width of the vehicle, whereby the side electrode 17 is arranged at an appropriate position.

That is, as shown in FIG. 1, the vehicle width detection sensor 24
The vehicle body 4 is located upstream of the entrance side portion 10 of the vehicle.
Is formed by an optical sensor in which, for example, a light emitting element 26 and a light receiving element 27 are arranged above and below which light passes.
The plurality of light-emitting elements 26 and the light-receiving elements 27 are arranged to face each other along the vehicle width direction, and the vehicle body 4 passing by the movement of the conveyor 13 includes the plurality of light-emitting elements 26,
The vehicle width of the vehicle body 4 is detected by detecting which light emitting element 26 blocks the light. Note that such a vehicle width detection sensor 24 is not limited to an optical sensor, and may be configured by, for example, a discharge tube.

The position sensor 25 is constituted by, for example, a limit switch provided at a predetermined position in the conveying direction of the conveyor 13, and each of the hangers 14.
Each time the vehicle passes the limit switch, the limit switch is turned on, and the position of the vehicle body 4 suspended by each hanger 14 is detected. The position sensor 2
5 is not limited to a limit switch, and an encoder may be provided on the conveyor 13 to detect the position of the vehicle body 4 suspended by each hanger 14 from the number of revolutions thereof. A light emitting element and a light receiving element may be attached to both side walls of the tank 3 so that the passage of the vehicle body 4 is detected by an optical sensor. Although only one such position sensor 25 is shown in FIG. 1, a plurality of such position sensors may be provided at appropriate positions along the conveying direction of the conveyor 13.

Further, the vehicle width detection sensor 24 described above
The position detection sensor 25 may also be used, and the vehicle width of each vehicle body 4 may be detected, and the fact that the vehicle body 4 has passed the vehicle width detection sensor 24 may be transmitted to the CPU as a detection signal. Further, the vehicle width detection sensor 24 and the position sensor 25 are, for example,
And an identification mark such as an IC card is attached to each of the vehicle bodies 4 and the vehicle body 4 is attached to the identification mark.
The vehicle width and the position of the vehicle body 4 are sent to the CPU as a detection signal by reading the identification mark by a lead sensor at a predetermined position in the conveying direction of the conveyor 13 after giving information such as the vehicle width of the vehicle. May be sent.

Then, based on the vehicle width information and the position information of the vehicle body 4, the CPU operates the side electrodes 1.
A time when the vehicle body 7 and the detected vehicle body 4 face each other is calculated, and the piston rod 23 of each side electrode 17 is driven according to the vehicle width of the vehicle body 4 in accordance with the calculated time. Thus, by arranging each side electrode 17 at an appropriate position corresponding to the vehicle body 4, an appropriate electrodeposition coating corresponding to the size of the vehicle body 4 is performed.

As described above, based on the detection signals from the vehicle width detection sensor 24 and the position sensor 25, each side electrode 1
7 is arranged at an appropriate position corresponding to the specific vehicle body 4, even if the vehicle bodies 4 of different sizes are irregularly transported in the sequentially transported vehicle bodies 4, each side electrode 17 Can always be reliably moved to an appropriate position according to the size of each vehicle body 4, and electrodeposition coating with a constant film thickness can be performed with better accuracy.

In the above description, the side electrode 1
7 is configured to be moved in the width direction of the vehicle body-4 by driving the cylinder 22. However, the driving means is not limited to the cylinder 22, and includes, for example, a gear drive, a chain drive, a pulley drive, and a solenoid. Driving may be performed, and the invention is not limited to driving continuously in the width direction, but may be driving by multi-stage switching or two-stage switching.

In the above description, each side electrode 17 is moved in the width direction with respect to the vehicle body 4. For example, each bottom electrode 18 is moved in the vertical direction with respect to the vehicle body 4. May be configured.

Further, in the above description, each side electrode 17 is arranged at an appropriate position corresponding to each vehicle body 4 based on detection signals from the vehicle width detection sensor 24 and the position sensor 25. Although such control is not performed, for example, each side electrode 17 is configured to be manually movable in the width direction, and the operator appropriately adjusts the size of each vehicle body 4 according to the size. Manually operate each side electrode 17
May be switched in the width direction.

In this electrodeposition coating apparatus 1, each side electrode 17 is provided with a vertically slidable shield as described in Japanese Patent Application Laid-Open No. Hei 7-150392, so that Depending on the shape of the body 4, for example, in a portion where the facing distance between the side electrode 17 and the surface to be painted of the vehicle body 4 is shorter, the shield is slid at a low speed to increase the shielding time, and Part electrode 17 and vehicle body 4
In a portion where the distance to the surface to be coated is longer, the shielding body may be slid at high speed to shorten the shielding time, so that the film thickness of each vehicle body 4 may be made uniform.

[0032]

According to the electrodeposition coating apparatus of the present invention, it is possible to perform electrodeposition coating with a constant film thickness even when the size of each object to be coated is changed in the object to be sequentially transported. .
Moreover, since the configuration is such that the electrode itself is only moved in the direction facing the object to be coated, it can be realized simply and at low cost.

If the electrode can be moved in the width direction on the side of the object to be coated, the electrode can be further simplified and reduced in cost.
Electrodeposition coating with a constant film thickness can be performed.

Further, if the electrodes are moved by the driving means based on the detection signals from the size detecting means and the position detecting means, the electrodes can always be reliably moved to the appropriate positions corresponding to the sizes of the objects to be coated. The electrodeposition can be performed, and electrodeposition coating with a constant film thickness can be performed with better accuracy.

[Brief description of the drawings]

FIG. 1 is a sectional side view of a main part showing an embodiment of an electrodeposition coating apparatus of the present invention.

FIG. 2 is a front sectional view of FIG.

FIG. 3 is a front sectional view of a main part in FIG. 2;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 electrodeposition coating apparatus 2 electrodeposition liquid 3 electrodeposition tank 4 vehicle body 13 conveyor 17 side electrode 18 bottom electrode 22 cylinder 24 vehicle width detection sensor 25 position sensor

Claims (3)

[Claims] An electrodeposition tank in which an electrodeposition liquid is stored, and transport means for sequentially transporting a plurality of the objects to be immersed in the electrodeposition tank so that the objects to be coated are immersed at a fixed distance, An electrodeposition coating apparatus comprising: a plurality of electrodes provided so as to face the object to be coated in the electrodeposition tank; wherein the electrode faces the object according to the size of the object to be coated. An electrodeposition coating apparatus, which is provided so as to be movable in a direction. 2. The electrode according to claim 1, wherein the electrode is provided on a side of the object to be coated, and is movably provided in a width direction of the object to be coated. Dressing equipment. 3. A driving unit for moving the electrode, a size detecting unit for detecting a size of the object to be coated, and a unit for detecting a position of the object in a conveying direction of the conveying unit. A position detecting unit, wherein the driving unit is configured to move the electrode in a direction facing the object to be coated based on detection signals from the size detecting unit and the position detecting unit. The electrodeposition coating apparatus according to claim 1, wherein: