JPH01205096A - Electrodedeposition device - Google Patents

Abstract

PURPOSE:To enable discrete setting of electrodedeposition conditions in a line where many kinds of materials to be coated coexist by providing a power supply device which applies a prescribed potential to the materials to be coated and providing a means for controlling sticking of a paint between the power supply means and the materials to be coated. CONSTITUTION:The materials A1-A2, B1-B5 to be coated are respectively mounted to a plate member 39 of a carrying jig 40 and are immersed one after another into an electrodedeposition coating liquid 3 in an electrodedeposition cell 2. The potential difference of DC is generated between a current collecting bar 13 connected to a negative terminal 15b of a DC power supply 19 of the power supply device 5 and an electrode 33 connected to a positive terminal 15a. Current collectors 14 supply the current from the bar 13 to control elements 23. The control elements 23 control the current to be supplied to the materials to be coated according to the thickness of the electrodedeposition coated film required for the materials to be coated. The paint 20 is moved and deposited onto the surfaces of the materials to be coated by electrophoresis, by which the electrodedeposition coated films are formed.

Description

[Detailed description of the invention] The present invention relates to an electrodeposition apparatus.

BACKGROUND ART Conventionally, for example, in an electrodeposition coating line, there has been a demand for forming an electrodeposition coating film with a uniform thickness on the object to be coated.

When electrocoating a single type of object or something that can be produced in lots, the optimal electrodeposition coating conditions are first set for each series of objects. All you have to do is maintain the optimum coating conditions.

However, in an electrodeposition coating line where many types of objects are mixed, it is necessary to increase the thickness of the electrodeposition coating, which has the greatest added value among the many types of objects to be coated. It is necessary to set electrodeposition coating conditions according to the object to be coated (high-grade object to be coated).

For this reason, there is a risk that the electrodeposited film thickness will be excessive for intermediate-grade and F-class coated objects that are located before and after the high-grade coated object and flow through the line.

In addition, it is suitable for objects to be coated that have parts where it is necessary to maintain electrodeposition coating conditions within a predetermined range, such as objects to be painted where it is necessary to prevent poor fitting at fitting parts such as screw hole machining parts. It is necessary to separately set conditions for electrodeposition coating, and it is difficult to place such a coating device before and after the above-mentioned F class object and run a mixed line.

The present invention has been made in view of the above-mentioned points, and its purpose is to provide an electrodeposition coating line in which, for example, high-grade objects, intermediate-grade objects, and lower-grade objects flow together;
Or, even in an electrodeposition coating line where 10th grade workpieces and objects to be coated that require high processing dimension accuracy coexist, electrodeposition equipment can be used to set electrodeposition conditions to suit each object to be coated. The aim is to encourage

The purpose of the present invention is to provide a tank for storing an electrodeposition solution, and a tank for transporting the object to be coated so that the object to be coated is present in the electrodeposition solution contained in the tank. a power source means for supplying a predetermined potential to the electrodeposition liquid to apply a predetermined potential to the electrodeposition liquid in order to deposit the paint contained in the +Wf electrocoating liquid onto the object to be coated; This is achieved by an electrodeposition apparatus comprising a control means disposed between the power supply means and the object to be coated to control the adhesion of the paint to the object.

That is, the electrodeposition apparatus of the present invention allows electrodeposition coating conditions to be set according to each object to be coated, and performs electrodeposition coating so that different electrodeposition film thicknesses can be formed in one electrodeposition tank ( 9.

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

In each of FIGS. 1 to 3, an electrodeposition coating apparatus 1 as an electrodeposition apparatus has an electrodeposition tank 2 as a tank filled with an electrodeposition coating liquid 3 as an electrodeposition liquid, and an electrodeposition coating apparatus 1 as an electrodeposition apparatus. 1 to A2 to a plurality of different types of objects to be coated in the electrodeposition coating liquid 3 contained in the tank 2.
81 to B5 are irregularly present at the same time on the object to be coated A1 to A2. A ceiling conveyor installed on the ceiling as a conveying means for sequentially and continuously conveying B1 to B5, more specifically a trolley conveyor 4, and a conveyor to convey objects 1 to A to be coated.
2.81 to B5 to apply the paint 20 in the electrodeposition coating liquid 3 to the objects to be coated A1 to A2.81 to 8 by electrodeposition.
5 to apply a predetermined potential to each of the objects to be coated A1 to A2.
A power supply unit @5 as a power supply means connected to B1 to B5 and the electrodeposition tank 2, respectively, and objects to be coated A1 to A2. Bl~B5
An electric transmission path 8 connected to one end 15b of the power supply device 5 and the individual objects to be coated A1 to A2. Bl～
It is composed of a plurality of controls 211 and a neck mount 6 disposed between the power transmission line 8 and the control device 6, and the electric transmission line 8 and the control device 6 constitute a control means. Further, the electrical transmission path 8 is formed of a conductive material. The electric transmission path 8 is insulated and supported by a suitable means such as the ceiling (not shown).

Generally, the thickness of the electrodeposition coating film to be formed on the object to be coated is determined.
There are the following elements to achieve this.

(a) The proportions of the components of the electrodeposition coating solution, such as the type of paint, solid content, amount of solvent, and amount of neutralization.

(b) Temperature of the electrodeposition coating liquid.

(c)? g! m The height of the voltage applied to the equipment.

(d) Time of energization applied to the object to be painted.

(e) Physical distance between the object to be painted and the electrode that applies voltage to the object.

(f) Ratio of opposing areas between the object to be painted and the lightning chamber that applies voltage to the object.

(g) Amount of current applied to the object to be painted.

Therefore, if two or more types of objects to be coated, which require different electrodeposition coating conditions to be set, are mixed in one electrodeposition coating tank and the flow rate is 1°, each object will be coated separately. In order to set the electrodeposition coating conditions, from (C) above to (hl
Any or any combination of the preceding elements may be selected.

In this specific example shown in FIG. 1, the inner wall 301 of the electrodeposition bath 2
．． : is equipped with an insulating lining, such as a vinyl chloride sheet (hereinafter abbreviated as PVC sheet) 31, for electrically insulating between the electrodeposition bath 2 and the electrodeposition coating liquid 3. Further, the power supply device 5 rectifies the AC voltage supplied from the AC power supply 32, preferably sets the voltage to 100 V to 300 V, and supplies a DC current. 19, and a switch 16 for supplying direct current from the power transmission line 8 to the current collection bar 13. Positive terminal 1 of power supply 5! ia t
Also, a plurality of holes (~33 portions 5 of each electrode 33
0, and the negative end f15b is connected to the end 7 of the current collecting bar 13 via the switch 16. That is, the objects A1 to be coated connected to the current collecting bar 13 via the control device 6
A2. Each of Bl to B5 functions as a cathode, and the electrodeposition tank 2
Each of the four cut electrodes 33 attached to the inner wall 30 of the cell via a PVC sheet 31 is configured to function as an anode.

The electrodeposition tank 2 contains water 21 and a solid content concentration of 10 in the water 21.
It is filled with an electrodeposition coating liquid 3 composed of a paint 20 which is dissolved and dispersed at ~25%.

The electrodeposition tank 2 has an overflow tank and a flow tank 1 adjacent to the electrodeposition tank 2.
7 is provided, and the electrodeposition tank 2 and overflow tank 1 are
7 by passage 34 on the one hand and passage 35.3 on the other hand.
6, and the electrodeposition coating liquid 3 is connected to the pump 3.
Pump 37 and passage 36 along arrow 38 direction by 7
, the electrodeposition bath 2, the passage 34, the overpuff [1-bath 17 and the passage 38]. In addition, passage 34.35.3
PVC sheets 3 are also applied to the inner walls of each of the overflow tank 6 and the overflow tank 17.
1 is tied. In addition, as mentioned above, to the object to be coated
82. Since each of 84 to 85 functions as a cathode,
The paint 20 of the electrodeposition coating liquid 3 is such that it can be deposited at the cathode.
In other words, it is necessary to select a paint that has a positive charge in water.

Note that it is of course possible to select a paint that has a negative charge in water instead of a paint that has a positive charge in water, but in that case, each of the objects A1 to A2 and 81 to B5 is anode It is necessary to change the connection between the positive terminal 15a and the negative terminal 15b of the power supply device 5 so that the electric field 33 functions as a cathode.

It consists of a rail system @ 22 for conveying in the direction of. In addition, the conveyance Z shell 40 is rotated and moved on the rail device 22 by a roller 41, a shaft member 42 that rotatably supports the roller 41, and a shaft member 42 that rotatably supports the roller 41.
a plate member 39 for attaching each of 1 to 85;
It is constituted by a rod member 11 connected to the play 1 member 39 by the portion 10 of the play 1 to member 39, and an insulating member 43 for electrically insulating between the rod portion 11 and the shaft member 42. There is.

To the object to be painted 1 to 2, 81 to B5 are connected to each of the plate members 39, along the direction of extension of the rail device 22, i.e. from left to right M4 in FIG. It is transported in the direction towards. During this transportation, a plurality of objects 1 to A2 and 81 to B5 are simultaneously dipped into the electrodeposition coating liquid 3 in the electrodeposition tank 2. In the embodiment shown in FIG. 1, the trolley conveyor 4 is constructed so that three to four objects to be coated can be immersed at the same time. The control device 6 also includes a plurality of current collectors 14 that are attached to the bar member 11 and that are in electrical sliding contact with the current collecting bar 13 to receive the current supplied from the current collecting bar 13. Adjust the current received by the to the desired amount of current, and
2. It is composed of a control element 23 for supplying to each of 81 to 85. The current collector 14 and the current collector bar 13 are preferably made of steel. Note that the control device 6 has a time control 1 as a control element 23 that controls the current supply time instead of adjusting the current flow received by the collector 14.
It may be configured by one element, or it may be a voltage control element that controls the magnitude of the voltage supplied from the collector bar 13, or it may be configured by combining these time control, voltage control, and current control, respectively. It may be configured.

Normally, a device (not shown) is placed adjacent to the electrodeposition tank 2 for washing the object to be coated with water after Ti@ coating. Devices for washing with water include, for example, a water tank washing device, a shower type washing device, a dip washing device, and the like.

Next, the operation of the electrodeposition apparatus in the specific example shown in FIGS. 1, 2, and 3 will be explained.

First, the carriers 1 to 2 and 81 to B5 are attached to the plate member 39 of the conveyance tool 40 on the conveyor 4. Then, the trolley conveyor 4 is put into operation so that the U-ra 41 rolls on the rail device 22, and the objects 1 to 82 are conveyed to the object to be coated. Bl to B5 are sequentially conveyed in the direction of arrow 9,
They are successively dipped into the electrodeposition coating liquid 3 filled in the electrodeposition tank 2.

Prior to this, the switch 16 of the power supply unit @5 is turned on. A DC potential difference occurs between the current collecting bar 13 connected to the negative terminal 15b of the DC power source 19 and the electrode 33 connected to the positive terminal 15a of the DC power source 19. A current collector 14 is in contact with the current collecting bar 13, and the current collector 14 supplies the current from the current collecting bar 13 to the control cord 23. The control cord 23 is set to a desired state in order to control the current supplied to the object to be coated according to the thickness of the electrodeposition coating required by the object to be connected.

In such a state, 1~A2.81~ to the object to be painted.
B5 is immersed one after another into the electrodeposition coating liquid 3, and when a direct current is passed between the cathode of the object to be coated and the anode of the electrode 33, the paint 20 is electrophoretically transferred to the object to be coated. moving to the surface. Electrolysis of water 21, which is a solvent, occurs on the surfaces of the anode and cathode, and the electrode 3, which is an anode,
The hydroxide ion concentration increases on the surface of No. 3, making it acidic and generating oxygen gas, and the hydrogen ion concentration increases on the surface of the cathode, which becomes alkaline and generating hydrogen gas. For this reason, in this specific example, the electrodeposition tank 2 is filled with the electrodeposition coating liquid 3 composed of the electrodeposition paint 20 which has a positive charge in water and water 21 which is the solvent of this electrodeposition paint 20. , the electrodeposited particles 20 aggregate and precipitate near the surface of the object to be coated. In this way, an electrodeposition coating film is formed on the surface of the object to be coated.

In this specific example, a current control water element is used as the control element 23 of the control device 6, but more specifically, the current control may be performed by making the resistance value variable, for example. is preferred. Furthermore, by selecting the material of the current collector 14, the resistance value can be adjusted arbitrarily in order to set the current supplied to each object to be coated according to the unique thickness of the electrocoated film required for each object. You may also set it to .

Next, a second specific example of the electrodeposition apparatus of the present invention will be described.

In FIGS. 4 and 5, parts common to the first specific example shown in FIGS. 1, 2, and 3 are given the same reference numerals, and the functions related to those parts are and 01
Since the works are common, their explanation will be omitted here.

The second specific example differs from the first specific example in that a plurality of power incoming bars are provided.

That is, as shown in FIGS. 4 and 5, the negative terminal 15b of the DC power supply 19 of the power supply device 5 as a power supply means is connected to the power supply bars 13^, 13B via the switch 16, and the ends 7A,
7B are connected to each other.

Further, the current collectors of the control device 6 are selected corresponding to 1 to A2 and 81 to B5, respectively, to the objects to be coated connected to the plate member 39 of the conveying jig 40 in the trolley conveyor 4 as a conveying means. Ru. That is, the current collector 14A is connected to the plate member 39 that connects the objects to be painted ^1 to A2, and the current collector 14A is connected to the plate member 39 that connects the objects to be painted ^1 to B5.
B are installed respectively, and the collector 14A is connected to the incoming power bar 13.
In A, the current collectors 14B are configured to be able to electrically come into sliding contact with the power incoming bar 13B.

These power incoming bars 13^, 13B and the control device constitute a control means. Therefore, plate member 39
1 to A2 to the workpiece connected to the workpiece. When moving in the direction of arrow 9 along the extension direction of the rail device 22 of each trolley conveyor 4 of 81 to 85, 1 to A2 to the workpiece connected to P
If the J position is changed to the J position, the electric I! ! ! The dynamic contact state is released, and no current flows through each of the objects A1 to A2 to be coated. However, even when the objects B1 to B5 to be coated reach the positions indicated by points P, the electrical sliding contact state of the current collector 14B to the power incoming bar 13B is maintained, and the objects to be coated B1 to B85 are kept in contact with each other. current can still be passed.

In other words, the objects to be painted A1 to A2. Objects to be painted 81 to B5
Set the current supply time for each to a predetermined length,
Object to be painted ^1~A2. It is possible to produce the required thickness of the electrodeposition coating film corresponding to each of Bl to 85. In this second specific example, the 'di? The coating film No. 7 is thicker than the electrodeposited coating films of the objects A1 to A2.

In the second specific example, as in the first specific example, materials with different resistances for the current collector are selected depending on the objects to be coated, that is, the materials required for each object to be coated are selected. The amount of current supplied to the object to be coated may be set as desired depending on the specific thickness of the electrodeposited coating film. Similarly, the power supply bar may be constructed so that materials with different resistances are selected depending on the object to be coated. Furthermore, as elements for controlling the thickness of the electrodeposition coating film in the second specific example, a) changing the length of the coming bar (time control) b) changing the material of the coming bar (changing the amount of current) Control) C) Changing the material of the current collector (control of current amount) may be adopted, or a) +
c) A combination of b)+c) may also be used.

From the above, since the electrodeposition apparatus of the present invention has the above-described configuration, it can be used in an electrodeposition work line where many types of workpieces coexist.
3, the electrodeposition conditions can be individually set according to each workpiece, so that the thickness of the electrodeposition film required for each workpiece can be produced as desired.

[Brief explanation of the drawing]

FIG. 1 is a schematic overall explanatory diagram of a preferred embodiment of the present invention, FIG. 2 is a plan view of FIG. 1, and FIG.
4 is a schematic illustration of another preferred embodiment of the present invention, and FIG. 5 is a sectional view taken along line v--v in FIG.
FIG. 1... Electrodeposition coating device, 2... Electrodeposition tank,
3... Electrodeposition coating liquid, 4... Trolley conveyor, 5... Electric 1IPi device, G...
Control device, 1...Terminal, 8...Electrical transmission line, 81-A2.81-B5...Object to be painted. Representative Patent Attorney Takeshi Funayama Figure 5

Claims (3)

[Claims] (1) A tank for storing an electrodeposition liquid, a conveying means for transporting the object to be coated so that the object to be coated is present in the electrodeposition liquid contained in the tank, and the object to be coated. a power supply means for applying a predetermined potential to the electrodeposition liquid to the object to be coated in order to cause the paint contained in the electrodeposition liquid to adhere to the object; and a power supply means for controlling the adhesion of the paint to the object to be coated. An electrodeposition apparatus comprising a control means disposed between the means and the object to be coated. (2) The electrodeposition apparatus according to claim 1, wherein the control means comprises a current control element that controls the current from the power supply means. (3) The electrodeposition apparatus according to claim 1 or 2, wherein the control means comprises a time control element that controls the supply time of current from the power supply means.