JP6648538B2 - Electrodeposition coating equipment - Google Patents

Description

  The present invention relates to an electrodeposition coating apparatus for performing electrodeposition coating of an object to be coated while flowing an electrodeposition coating liquid through an electrodeposition tank.

  2. Description of the Related Art Conventionally, a cationic electrodeposition coating apparatus capable of forming a uniform coating film even on a component having a complicated shape in order to ensure rust prevention such as an automobile body is known (for example, Patent Documents 1 to 4). 2). This electrodeposition coating apparatus applies a voltage to a cathode composed of an automobile body (object to be coated) and an anode disposed in an electrodeposition tank to form anion of water electrolyzed at the cathode. It reacts with a cationic electrodeposition coating liquid to deposit a coating film on an object to be coated.

  The electrodeposition coating apparatus disclosed in Patent Document 1 arranges a propeller stirrer inside an automobile body and directly agitates the electrodeposition coating liquid inside the body to increase the flow velocity near the inner surface of the body while coating the bag-shaped portion. The flow rate is controlled so that the film deposition amount becomes near the maximum value. It is described that the thickness of the bag-shaped portion can be increased by reducing the thickness of the inner surface of the body.

  The electrodeposition coating apparatus of Patent Document 2 is provided with a plurality of injection nozzles and the like just below the liquid level of an electrodeposition tank and on a side wall to increase the flow rate of the electrodeposition coating liquid on the surface of an automobile body and increase the film thickness. is there. In addition, Patent Document 2 describes that when the flow velocity is equal to or higher than the inflection point, the outgassing action of hydrogen gas generated at the cathode is promoted, the electric resistance value of the body surface decreases, and the film thickness increases. .

JP-A-10-237695 JP 2000-119897 A

  However, in the electrodeposition coating apparatus of Patent Document 1, it is necessary to install a propeller stirrer in order to increase the flow rate of the electrodeposition coating liquid, and the apparatus becomes large. In addition, the technique of installing a propeller stirrer inside an object to be coated cannot secure an installation space when performing electrodeposition coating on a small automobile part.

  On the other hand, in the technique of providing a plurality of spray nozzles directly below the liquid level of the electrodeposition tank and on the side wall as in Patent Document 2, it is difficult to increase the flow velocity inside the object to be coated, and the hydrogen gas generated at the cathode is coated with hydrogen gas. And may cause gas pinholes. In particular, when the applied voltage is increased to increase the coating speed, a large amount of hydrogen gas is generated, and the coating film is likely to be broken. As a result, desired rust prevention performance cannot be exerted on the object to be coated.

  Therefore, there is a demand for an electrodeposition coating apparatus capable of forming a smooth coating film while increasing the coating speed even when applying electrodeposition coating to small automobile parts.

Characteristic feature of the electrodeposition coating device, electrodeposition coating solution bathing the entire area of the coated article through the space along the longitudinal direction of the elongated is formed is housed, the longitudinal direction of the object to be coated as a vertical direction An electrodeposition bath disposed therein, a first electrode portion connected to the object to be coated, a second electrode portion disposed inside the electrodeposition bath and serving as a counter electrode to the first electrode portion, and A first ejection part for ejecting the electrodeposition coating liquid from the side of the object toward the object to be coated, and the electrodeposition coating liquid from below the electrodeposition tank toward the penetration space of the object to be coated. A second jetting unit for jetting, and when applying a voltage to the first electrode unit and the second electrode unit, the electrodeposition coating liquid is jetted simultaneously from the first jetting unit and the second jetting unit. On the point.

  In the first electrode portion, the electrodeposition coating solution reacts with ions (cations in anion electrodeposition coating and anions in cation electrodeposition coating) generated by electrolysis of water to deposit a coating film on an object to be coated. . At this time, bubbles (oxygen gas in anion electrodeposition coating and hydrogen gas in cation electrodeposition coating) are generated in the first electrode portion. When these bubbles stay in the coating film, the coating film resistance is reduced and the coating film is hardened by electric discharge, and gas pinholes are formed after baking. In particular, when the applied voltage is large, the electrolysis of water is promoted at the portion where the coating film resistance is reduced, and a large amount of air bubbles are generated. Membrane destruction). As a result, a smooth coating film is not formed, and the desired rust prevention performance cannot be exhibited.

  However, the second ejection section in the present configuration ejects the electrodeposition coating liquid from below the electrodeposition tank toward the object to be coated. For this reason, bubbles existing in the coating film of the object to be coated are separated upward by the electrodeposition coating liquid and taken out of the coating film. As a result, bubbles do not stay in the coating film, and the occurrence of coating film destruction can be prevented. Further, since the electrodeposition coating liquid is jetted from the side of the object to be coated by the first jetting portion, the separation of bubbles existing in the coating film of the object to be coated is promoted.

  On the other hand, there is a possibility that the air bubbles taken out of the object to be coated re-adhere to the coating film of the object to be coated. However, in this configuration, the longitudinal direction of the object to be coated is arranged in the up-down direction, and the second jetting portion allows the electrodeposition coating liquid to flow upward from below, so that the air bubbles are smoothly prevented from interfering with the object to be coated. To rise. As a result, the inconvenience of air bubbles re-adhering to the coating film is eliminated, and a smooth coating film can be reliably formed.

  As described above, since bubbles can be quickly removed from the coating film of the object to be coated, the bubbles do not stay and break the coating film even when a large voltage is applied. That is, in general, the higher the applied voltage, the sooner the coating film is formed. Therefore, in the present configuration, it is possible to increase the applied voltage and increase the coating speed as compared with the related art. Therefore, by adopting this configuration, it was possible to provide an electrodeposition coating apparatus capable of forming a smooth coating film while increasing the coating speed.

  Another characteristic configuration is that a reservoir is provided adjacent to the electrodeposition tank and accommodates the overflowing electrodeposition coating liquid, and is provided on an upper portion of the first ejection section, and the reservoir holds the electrodeposition coating liquid. And a third jetting portion for jetting toward the portion.

  The bubbles taken out of the coating film of the object to be raised rise and are slowly discharged from the liquid level of the electrodeposition tank. At this time, if a large amount of air bubbles are generated, the discharge efficiency may be reduced and the air bubbles may flow back around the object to be coated. If a third ejection unit for ejecting the electrodeposition coating liquid toward the reservoir is provided as in the present configuration, the bubbles staying on the liquid surface of the electrodeposition tank move toward the reservoir. As a result, the air bubbles removed from the coating film of the object to be coated can be smoothly discharged to the outside without flowing back around the object to be coated. Therefore, the bubbles can be prevented from re-adhering to the coating film, and a coating film having smoothness can be more reliably formed. In addition, if the third ejection section is provided above the first ejection section, it is not necessary to separately provide the third ejection section, which is efficient.

  Another characteristic configuration is that the first ejection section is provided in a plurality along the circumferential direction of the electrodeposition tank, and ejects the electrodeposition coating liquid from below the electrodeposition tank to form each of the first ejection sections. And a fourth ejection portion for generating an upward flow while being along the circumferential direction of the portion.

  As in the present configuration, in addition to the second ejection portion, by providing the fourth ejection portion for flowing the electrodeposition coating liquid upward from below, the rising speed of the bubbles is increased, and the bubbles are re-adhered to the coating film. Can be reliably prevented. In addition, since the direction in which the electrodeposition coating liquid flows by the fourth ejection part is set along the circumferential direction of the first ejection part, which is a region that does not interfere with the ejection area of the first ejection part, The flow direction of the coating liquid is constant from bottom to top, and air bubbles can be smoothly guided to the liquid surface.

  Another characteristic configuration includes a control unit that sets a jetting speed of the electrodeposition coating liquid in the first jetting unit and the second jetting unit according to a voltage applied to the first electrode unit and the second electrode unit. It has a point.

  The applied voltage is set according to the target value of the film thickness formed on the workpiece. If the jetting speed of the electrodeposition coating liquid is increased, bubbles generated in the coating film are surely removed. However, when the applied voltage is small, the coating film can be prevented from being broken even if the jetting speed is set low. Thus, as in this configuration, if the ejection speed of the electrodeposition coating liquid is set according to the applied voltage, power consumption can be reduced.

  Another characteristic configuration is that the first ejection portion is disposed closer to the object to be coated than between the side wall of the electrodeposition tank and the object to be coated.

  As in the present configuration, by causing the first ejection portion to approach the object to be coated, the ejected electrodeposition coating liquid can collide with the side surface of the object to be coated. As a result, it is possible to forcibly remove bubbles generated in the coating film of the object to be coated.

1 is an overall view of an electrodeposition coating apparatus according to the present embodiment. It is a perspective view which shows the ejection part which concerns on this embodiment. FIG. 3 is a view taken in the direction of arrows III-III in FIG. 1. FIG. 3 is a diagram illustrating a relationship between a jet velocity and a voltage at which coating film destruction occurs. FIG. 4 is a diagram illustrating a relationship between an applied voltage and a coating speed when a jet velocity is changed. It is an external appearance photograph of the to-be-coated object which concerns on a present Example. It is an external appearance photograph of the to-be-coated object which concerns on a comparative example. It is a perspective view which shows the ejection part which concerns on another Embodiment 1. It is a perspective view which shows the ejection part which concerns on another Embodiment 2. It is the figure which looked at the electrodeposition coating device concerning another embodiment 3 from the upper part.

  Hereinafter, an embodiment of an electrodeposition coating apparatus according to the present invention will be described with reference to the drawings. As the electrodeposition coating apparatus X in the present embodiment, a cation electrodeposition coating liquid 2 (an example of an electrodeposition coating liquid) is electrodeposited using a workpiece 41 (an example of an object to be coated) as a cathode section 4 (an example of a first electrode section). An example of painting will be described. However, without being limited to the following embodiments, various modifications can be made without departing from the scope of the invention.

  1 to 3 show an electrodeposition coating apparatus X. FIGS. 4 and 5 show plots of the relationship between the ejection speed index and the coating film destruction and the relationship between the applied voltage and the coating speed index when the cationic electrodeposition coating is performed by the electrodeposition coating apparatus X. It is. It should be noted that the numerical values described in detail in the following embodiments are examples, and are not limited.

[Basic configuration]
As shown in FIG. 1, the electrodeposition coating apparatus X is arranged such that the longitudinal direction of a long workpiece 41 is arranged in the vertical direction, and is connected to the electrodeposition tank 1 containing the cationic electrodeposition coating liquid 2 and the workpiece 41. The cathode unit 4 includes an anode unit 5 (an example of a second electrode unit) which is disposed inside the electrodeposition tank 1 and is a counter electrode to the cathode unit 4. In addition, a reservoir 11 for containing the overflowed cationic electrodeposition coating liquid 2 is provided adjacent to the electrodeposition tank 1. The work 41 to be electrodeposited in the present embodiment is assumed to be a small automobile part requiring rust prevention and aesthetics, such as a guide rail of a seat, a pipe, a division bar (a partition member of a window), and the like. ing. That is, the work 41 is formed in a long shape, and the through space 41a along the longitudinal direction is formed at the center.

  A work 41 is fixed at the center of the electrodeposition tank 1 in the present embodiment such that the penetration space 41a (longitudinal direction) extends in the vertical direction. In addition, in the electrodeposition tank 1, an introduction part 3 for introducing the cationic electrodeposition coating liquid 2 is formed near the bottom center. The pump 3 circulates the cationic electrodeposition coating liquid 2 in the reservoir 11 in the introduction section 3. Note that a replenishing unit (not shown) for replenishing the paint component taken out of the electrodeposition tank 1 as the painting of the work 41 progresses may be provided at the introduction unit 3 or at a location different from the introduction unit 3. Further, the cationic electrodeposition coating liquid 2 in the reservoir 11 may be filtered and circulated to the introduction part 3.

  The cationic electrodeposition coating liquid 2 is a vehicle in which a cationic electrolytic resin containing an additive and a solvent is added to an acrylic resin, an epoxy resin, an epoxy-polyamide resin, or the like, and a coloring material (vehicle) is used. Is dispersed in an aqueous medium.

  The cathode portion 4 is connected to the DC power supply 7 in a state where the work 41 is locked by the conductive locking member 42. As shown in FIG. 1, the work 41 is in a state in which all regions are immersed in the cationic electrodeposition coating liquid 2 stored in the electrodeposition tank 1.

  The anode portions 5 are made of stainless steel, a carbon plate, or the like, and are arranged at equal intervals along the circumferential direction of the cathode portion 4 as shown in FIG. Further, the cathode section 4 and the anode section 5 are arranged so that the distance L1 between the electrodes is kept at a predetermined distance (for example, 5 cm).

  By the way, in a general electrodeposition coating process, a phosphate-based surface treatment is performed by degreasing before applying the cationic electrodeposition coating. Next, after a coating film is formed on the work 41 in the cationic electrodeposition coating process, a baking process is performed through a water washing process, and the electrodeposition coating of the work 41 is completed. Since the cationic electrodeposition coating has a property that a coating film is sequentially formed on the work 41, the so-called throwing power is high, and an excellent thickness capable of forming a uniform film thickness and exhibiting a desired rust prevention performance can be exhibited. It is a painting method.

  In the cationic electrodeposition coating process, hydroxide ions generated by electrolysis of water in the aqueous solvent react with amino groups in the cation-electrolytic resin to form a water-insoluble material on the workpiece 41 of the cathode portion 4. A coating is formed. As shown in FIG. 5, it is known that, when the voltage applied to the cathode portion 4 and the anode portion 5 is increased, the above reaction is accelerated, the coating speed is increased, and the film is further increased. On the other hand, in the cathode section 4, the hydrogen ions receive electric charges, and hydrogen gas is generated. At this time, if the voltage applied to the electrode portions 4 and 5 is increased, a large amount of hydrogen gas stays in the coating film of the work 41 and the growth of the coating film is likely to be hindered. For this reason, the coating film hardens due to a decrease in the coating film resistance and discharge, and gas pinholes are formed after baking.

  In particular, when the voltage applied to the electrode portions 4 and 5 is too high, a large amount of hydrogen gas is generated, and the hydrogen gas remaining in the coating film of the work 41 in the baking process destroys the coating film. A crater-like portion is formed on the surface of the work 41. As a result, the appearance becomes poor and the desired rust prevention performance cannot be exhibited.

  This appearance defect differs depending on various conditions such as bath resistance and electrolyticity of the cationic electrodeposition coating solution 2, the shape and arrangement of the anode part 5, and the material and shape of the work 41. However, coating film destruction generally occurs from 230V or more. Tends to be easier.

  Therefore, in the electrodeposition coating apparatus X according to the present embodiment, the first ejection unit 12 that ejects the cationic electrodeposition coating liquid 2 from the side of the work 41 toward the work 41, and the work 41 from below the electrodeposition tank 1. A second ejection section 13 for ejecting the cationic electrodeposition coating liquid 2 toward the through space 41a (the longitudinal direction of the work 41) is provided. In addition, a distribution box 31 for distributing the cationic electrodeposition coating liquid 2 to the ejection sections 12 and 13 is connected to the introduction section 3. Since the distribution box 31 has a buffer function for storing the cationic electrodeposition coating liquid 2, the ejection pressure of the ejection portions 12, 13 can be set to an appropriate value.

  The electrodeposition coating apparatus X controls the discharge pressure of the pump P to control the discharge speed of the cationic electrodeposition coating liquid 2 discharged from the discharge units 12, 13 via the distribution box 31. Have.

  As shown in FIGS. 2 and 3, each of the first ejection portions 12 extends in an L-shaped tubular shape on two side surfaces of the distribution box 31. In other words, a plurality of (in this embodiment, two) first ejection portions 12 are provided at equal intervals along the circumferential direction of the electrodeposition tank 1, and the interval L2 between the first ejection portions 12 facing each other is a predetermined value. (For example, 20 cm). The first ejection portion 12 has ejection holes 12a formed on the side surface of the work 41 at a predetermined pitch (for example, 9 cm pitch). In addition, the 1st ejection part 12 may be provided in one place or three or more places, and may be provided at irregular intervals.

  As described above, since the cationic spraying liquid 2 is sprayed to the side surface of the work 41 by the first spraying unit 12, bubbles existing in the coating film on the side surface of the work 41 are removed by the cationic spraying solution 2. You are taken out. Further, it is preferable that the first ejection portion 12 is arranged on the side of the work 41 from the middle between the side wall of the electrodeposition tank 1 and the work 41. That is, as shown in FIG. 1, the distance L3 between the inside of the first ejection portion 12 and the outer surface of the work 41 is smaller than half the distance L4 between the inner surface of the side wall of the electrodeposition tank 1 and the outer surface of the work 41. Preferably, it is set. In addition, the distance between the inside of the first ejection part 12 and the outer surface of the work 41 may be set smaller than the distance between the inner surface of the cathode part 4 and the outer surface of the work 41. In this way, by bringing the first ejection part 12 closer to the work 41 side, the ejected cationic electrodeposition coating liquid 2 can collide with the side surface of the work 41. As a result, air bubbles generated in the coating film of the work 41 can be forcibly removed.

  As shown in FIGS. 2 and 3, the distribution box 31 has a second ejection part 13 having a hole shape on the center upper surface. The second ejection portion 13 may be provided at one place or at a plurality of places. That is, the cationic electrodeposition coating liquid 2 is ejected from the second ejection portion 13 into the inside of the penetration space 41a in a state where the penetration space 41a of the work 41 is arranged in the up-down direction. As a result, bubbles existing in the coating film inside the work 41 are taken out of the coating film by the cationic electrodeposition coating liquid 2. As a result, bubbles do not stay in the coating film, and the occurrence of coating film destruction can be prevented.

  On the other hand, there is a possibility that bubbles taken out of the work 41 may adhere to the coating film of the work 41 again. However, by flowing the cationic electrodeposition coating liquid 2 from below to above the object to be coated by the second ejection part 13, the rising speed of the bubbles is increased, and the bubbles are prevented from re-adhering to the coating film. As a result, a smooth coating film can be reliably formed.

  Further, by providing the jetting parts 12 and 13 in the electrodeposition coating apparatus X, as shown in FIG. 4, it is possible to increase the applied voltage at which the coating film is not broken. In particular, in the present embodiment, the relationship between the breakdown voltage (limit voltage) and the ejection speed index is defined. If the jetting speed of the cationic electrodeposition coating liquid 2 from the jetting parts 12 and 13 is increased about four times from A (L / min) to B (L / min), the applied voltage that does not cause the destruction of the coating film is about 1. It can be increased up to three times (hereinafter referred to as “maximum voltage”). On the other hand, since the coating film breakdown voltage does not increase even if the ejection speed is set to B (L / min), the ejection speed is preferably approximately B (L / min) under the above-mentioned set conditions of the electrodeposition coating apparatus X.

  Moreover, as shown in FIG. 5, when the same voltage is applied, the ejection speed of the cationic electrodeposition coating liquid 2 from the ejection portions 12 and 13 does not affect the coating speed. That is, the throwing power of the cationic electrodeposition coating liquid 2 does not decrease even if the ejection speed can increase the applied voltage. As described above, the electrodeposition coating apparatus X according to the present embodiment can surely form a smooth coating film while increasing the coating speed by increasing the applied voltage compared to the related art.

  The applied voltage is set according to the film thickness formed on the work 41. If the jetting speed of the cationic electrodeposition coating liquid 2 is increased, bubbles generated in the coating film are surely removed. However, when the applied voltage is small, the coating film can be prevented from being broken even if the jetting speed is set low. . Therefore, the control unit 8 in the present embodiment sets the ejection speed of the cationic electrodeposition coating liquid 2 in the ejection units 12 and 13 according to the voltage applied to the cathode unit 4 and the anode unit 5. Thereby, a coating having a desired film thickness can be formed on the surface of the work 41.

  Hereinafter, examples and comparative examples in the present embodiment will be described. As prerequisites for the present embodiment and the comparative example, a cold rolled steel plate (guide rail) having a U-shaped cross section with a depth of about 3 cm, a width of about 5 cm, and a length of about 38 cm is used for the work 41, and a columnar stainless steel for the anode part 5. The cathode part 4 was arranged at four places around the work 41, and the distance L1 between the electrodes of the cathode part 4 and the anode part 5 was set to about 5 cm. The entire area of the work 41 was immersed in the electrodeposition bath 1 filled with the cationic electrodeposition coating liquid 2 while the hole of the work 41 was hooked on the locking claw of the locking member 42.

[Example]
In the present embodiment, the interval L2 between the first ejection sections 12 facing each other is set to about 20 cm, and the ejection holes 12a of the first ejection sections 12 are formed at a pitch of about 9 cm. Further, the cation electrodeposition coating liquid 2 is jetted from the jetting parts 12 and 13 at B (L / min), and while the applied voltage is gradually increased for the first 10 seconds, the maximum voltage is increased for the remaining about 55 seconds. Applied.

  The workpiece 41 after electrodeposition coating and baking in this example had a smooth appearance and was in a good state as shown in FIG. Therefore, it was confirmed that good electrodeposition coating can be performed even in a high voltage region where gas pinholes and coating film breakage usually occur.

[Comparative example]
In this comparative example, the same maximum voltage as in the present example was applied over the remaining approximately 55 seconds while gradually increasing the applied voltage for the first 10 seconds without providing the ejection portions 12 and 13.

  As shown in FIG. 7, the work 41 after electrodeposition coating and baking in this comparative example had a crater-shaped depression in its appearance, and many of the depressions were scattered particularly near the edge portion of the work 41. . This is presumably because a large amount of hydrogen gas stayed in the coating film, the current was locally concentrated, and a discharge phenomenon occurred to harden the coating film. As described above, it was confirmed that when a large voltage was applied without providing the ejection portions 12 and 13, the coating speed did not increase and the coating film was destroyed.

  Hereinafter, another embodiment will be described using the same member names and reference numerals as in the above-described embodiment to facilitate understanding of the drawings.

[Another embodiment 1]
As shown in FIG. 8, the present embodiment is different from the above-described embodiment in that the cationic electrodeposition coating liquid 2 is ejected from the side of the work 41 and the cationic electrodeposition coating liquid 2 is directed toward the reservoir 11. That is, the third jetting portion 14 for causing the fluid to flow. The third jetting portion 14 is formed by using the same pipe member as the second jetting portion 13 and providing an jetting hole portion 14 a facing the reservoir 11 above each of the second jetting portions 13. In addition, the third ejection part 14 may be provided with a plurality of ejection holes 14 a facing the reservoir 11 over the entire length of the plurality of second ejection parts 13, or a pipe member different from the second ejection part 13 may be provided. It may be connected to the distribution box 31 and is not particularly limited. Further, the number of the third ejection portions 14 may be one, or may be an arbitrary number of two or more.

  The bubbles taken out of the coating film of the work 41 rise and are slowly discharged from the liquid surface of the electrodeposition tank 1. At this time, when a large amount of air bubbles are generated, there is a possibility that the discharge efficiency is reduced and the air bubbles flow back around the work 41. As in the present embodiment, if the third jetting part 14 for flowing the cationic electrodeposition coating liquid 2 toward the reservoir 11 is provided, the bubbles remaining on the liquid surface of the electrodeposition tank 1 are directed toward the reservoir 11. Moving. As a result, the bubbles removed from the coating film of the work 41 can be smoothly discharged to the outside without flowing back around the work 41. Therefore, the bubbles can be prevented from re-adhering to the coating film, and a coating film having smoothness can be more reliably formed.

[Another embodiment 2]
As shown in FIG. 9, the present embodiment differs from the above-described embodiment in that the cation electrodeposition coating liquid 2 is ejected from below the electrodeposition tank 1 and the first That is, a plurality of (four in the present embodiment) fourth ejection parts 15 that generate an upward flow are provided along the space. These fourth ejection portions 15 are provided at equal intervals around the second ejection portion 13 on the upper surface of the distribution box 31 and are formed in a hole shape. The fourth ejection portion 15 may be provided at one location, or may be provided at two or more locations at irregular intervals.

  In the present embodiment, in addition to the second ejection part 13, the fourth ejection part 15 for flowing the cationic electrodeposition coating liquid 2 from below to above the work 41 is provided, so that the rising speed of bubbles is increased and the coating film is formed on the coating film. The bubbles can be reliably prevented from reattaching. Moreover, since the ejection direction of the fourth ejection portion 15 is set to a region that does not interfere with the ejection region of the first ejection portion 12, the flow direction of the cationic electrodeposition coating liquid 2 is fixed from bottom to top. In addition, air bubbles can be smoothly guided to the liquid surface.

[Another embodiment 3]
As shown in FIG. 10, a plurality of device groups having the work 41, the electrode units 4 and 5, and the ejection units 12 and 13 may be provided in parallel in the single electrodeposition tank 1. As a result, the number of works 41 that can be electrodeposited at one time is increased, and manufacturing efficiency is improved.

[Other Embodiments]
(1) The ejection holes 12a, the second ejection portions 13, and the ejection holes 14a and the fourth ejection portions 15 of the third ejection portions 14 in the above-described embodiment are formed in a hole shape. The present invention is not limited to this, and may be configured by a nozzle or the like. Further, the distribution box 31 may be omitted.

(2) In the above-described embodiment, four anode portions 5 are provided at equal intervals along the circumferential direction on the side of the work 41. However, the present invention is not particularly limited. Any arrangement may be used. Further, the shape of the anode part 5 may be any shape such as a columnar shape or a plate shape, and a holding member for holding the anode part 5 and the tube member of the first ejection part 12 is attached to the electrodeposition tank 1. May be provided.

(3) The form in which the work 41 is engaged and fixed to the cathode portion 4 in the above-described embodiment may be any form such as holding the work 41 with a sandwiching member.

(4) The control unit 8 in the above-described embodiment may include a temperature control unit or a concentration control unit that controls the temperature and the concentration of the cationic electrodeposition coating liquid 2 contained in the electrodeposition tank 1 at a constant level. In this case, the effect of preventing the solidification of the cationic electrodeposition coating liquid 2 and the stabilization of the film thickness can be expected.

(5) In the above-described embodiment, the cation electrodeposition coating is described as an example, but the electrodeposition coating apparatus X may be used for anion electrodeposition coating. In this case, the first electrode portion is constituted by an anode portion, and the second electrode portion is constituted by a cathode portion. Anion electrodeposition coating is performed on the anode portion and oxygen gas is generated. Also in this anion electrodeposition coating, since the oxygen gas staying in the coating film of the work 41 is effectively taken out by the jetting parts 12 and 13, it is possible to prevent the destruction of the coating film.

  INDUSTRIAL APPLICABILITY The present invention is applicable to an electrodeposition coating apparatus for electrodeposition coating a vehicle part or the like.

DESCRIPTION OF SYMBOLS 1 Electrodeposition tank 11 Reservoir part 12 First ejection part 13 Second ejection part 14 Third ejection part 15 Fourth ejection part 2 Cationic electrodeposition coating liquid (electrodeposition coating liquid)
4 Cathode unit (first electrode unit)
41 Work (object to be coated)
5 Anode part (second electrode part)
8 control part X electrodeposition coating equipment

Claims (5)

An electrodeposition bath in which a long and penetrating space along the longitudinal direction is formed, which contains an electrodeposition coating liquid that immerses the entire area of the object to be coated, wherein the longitudinal direction of the object to be coated is arranged in a vertical direction,
A first electrode unit connected to the object;
A second electrode unit disposed inside the electrodeposition tank and serving as a counter electrode to the first electrode unit;
A first ejection unit that ejects the electrodeposition coating liquid from the side of the object toward the object to be coated,
A second ejection unit that ejects the electrodeposition coating liquid from below the electrodeposition tank toward the penetration space of the object to be coated ,
An electrodeposition coating apparatus that, when a voltage is applied to the first electrode unit and the second electrode unit, ejects the electrodeposition coating liquid simultaneously from the first ejection unit and the second ejection unit . A reservoir provided adjacent to the electrodeposition tank and containing the overflowed electrodeposition coating liquid;
2. The electrodeposition coating apparatus according to claim 1, further comprising: a third ejection unit provided above the first ejection unit and ejecting the electrodeposition coating liquid toward the reservoir. 3. A plurality of the first ejection parts are provided along a circumferential direction of the electrodeposition tank,
4. The apparatus according to claim 1, further comprising: a fourth ejection unit that ejects the electrodeposition coating liquid from below the electrodeposition tank to generate an upward flow between the first ejection units along the circumferential direction. 3. The electrodeposition coating apparatus according to 2.   2. A control unit for setting a jetting speed of the electrodeposition coating liquid in the first jetting unit and the second jetting unit according to a voltage applied to the first electrode unit and the second electrode unit. 3. The electrodeposition coating apparatus according to any one of claims 1 to 3.   The electrodeposition coating according to any one of claims 1 to 4, wherein the first ejection portion is disposed closer to the object to be coated than an intermediate portion between a side wall of the electrodeposition tank and the object to be coated. apparatus.

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