JP3389847B2 - Electrocoating equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates to relates primarily full dip or half dip immersion漬型electrodeposition coating device preferably used in automobile bodies and parts of electrodeposition coating step,
In particular, the film thickness is controlled by controlling the effective area of the electrode.
Related to electrodeposition coating equipment.

[0002]

2. Description of the Related Art For painting automobile bodies, undercoat painting,
A three-coat coating system consisting of an intermediate coating and a top coating is adopted, and a dipping coating method in which the automobile body is completely submerged in the electrodeposition coating liquid is adopted in the undercoating process.

In this type of full-dip electrodeposition coating method, an automobile body, which is the object to be coated, is fixed by an overhead conveyor into an electrodeposition tank filled with an electrodeposition coating liquid while being mounted on a hanger. Delivered at speed.

The automobile body in the electrodeposition tank is about 30 °
After entering the tank at an angle of 3 and passing the inside of the tank for a total immersion time of 3 minutes or more, the tank is taken out at an angle of about 30 °. In the meantime, in the cationic type electrodeposition coating, a DC voltage of about 300 V is applied to the electrodeposition coating liquid via a plurality of electrode plates or electrode rods arranged on the side wall and the bottom wall of the electrodeposition tank, whereby the earth side is applied. Electrophoresis of paint particles occurs between the body and
An electrodeposition coating film is formed on the inner and outer plates of the body and the inner surface of the bag structure.

[0005]

By the way, in the conventional electrodeposition coating method, the electrodeposition film thickness formed on the surface of the object to be coated is
It was controlled mainly by the voltage applied to the electrode plate and the electrode rod. However, in a multi-vehicle type mixing line, a body with a small total surface area to be coated (for example, a small passenger car) or a large vehicle with a small distance between the electrodeposition plate and the like is flowed irregularly. The applied film thickness varies. For this reason, the applied voltage was adjusted to the car model that was the most difficult to secure the film thickness, that is, the applied voltage was set to a high value.Thus, a small car has a thicker film than a large car. There was a problem that the cost was increased due to excessive quality because the film became thicker than the part.

The present invention has been made in view of the above problems of the prior art, and controls the effective area of the electrode according to the condition of the object to be coated to control the film thickness for each vehicle type and part. It is an object of the present invention to provide an electrodeposition coating device that can be used .

[0007]

In order to achieve the above object, the electrodeposition coating apparatus of the present invention is provided with an electrodeposition tank filled with electrodeposition.
In an electrodeposition coating device in which the object to be coated is immersed in the coating liquid,
A diaphragm electrode disposed in the electrodeposition tank, the electrode and the coating target.
Is provided in the case of the diaphragm electrode between the object and
It consists of an insulating plate piece and closes most of the diaphragm electrode.
An open position where most of the diaphragm electrode and the diaphragm electrode are unshielded.
Movable space provided to be able to move continuously between the release position
Insulating masking body consisting of ride board and specifications of coated object
And / or depending on the site, by the masking body
At least one of a shielded area and a non-shielded area of the electrode
And a control means for controlling .

The film thickness of the electrodeposition coating film formed on the surface of the object to be coated mainly depends on the voltage applied to the electrode and the current density from the electrode. Is related to the effective area of the electrode and the distance between the electrode and the object to be coated. That is, if the effective area of the electrode is made variable, the electrodeposited film thickness can be controlled.

The present inventors have paid attention to this point and decided to control the effective area of the electrode with respect to the object to be coated according to the specification and / or site of the object to be coated. As a result, the electrodeposited film thickness can be controlled according to the specifications and / or parts of the object to be coated. Therefore, the film thickness can be controlled, and as a result, it becomes possible to make the electrodeposition film thickness uniform between the coated objects and over the entire coated object.

[0010] In the electrodeposition coating apparatus of the present invention, the effective area before Symbol electrodes, and controlling by interposing an insulating masking material between the electrode and the object to be coated.

When an insulating masking body is provided between the electrode and the article to be coated, the current density from the electrode to the article to be coated is reduced by that much. The deposited film thickness can be suppressed.

[0012]

[0013]

[0014]

[0015]

[0016]

In the electrodeposition coating apparatus of the present invention , the masking body is a movable slide plate that shields and unshields at least a part of the electrodes.

In the electrodeposition coating apparatus of the present invention , since the masking body is composed of the movable slide plate, it is possible to make the film thicker by opening the movable slide plate, and conversely, make the film thinner if the movable slide plate is closed. You can Further, by making the open / close position of the movable slide plate continuous, it is possible to control to a desired film thickness. In particular, if the masking body is composed of a movable slide plate, it can be housed, for example, in the case of the diaphragm electrode, so that the space required for the operation of the masking body can be minimized.

Further, the electrodeposition coating apparatus of the present invention is characterized in that the electrode is a diaphragm electrode, and the insulating masking body is provided in a case of the diaphragm electrode.

When the masking body is interposed between the electrode and the article to be coated, generally, the electrodeposition coating material adheres to the masking body, resulting in malfunction of the masking body or from the masking body to the electrodeposition tank. Although dust and the like brought in may pose a problem, by disposing the masking body in the case of the diaphragm electrode as in the present invention, the masking body is not soaked in the electrodeposition coating material and the masking body is prevented. Therefore, even if dust is brought in, it will not enter the electrodeposition tank.

The specification of the article to be coated is not particularly limited, but in the electrodeposition coating apparatus according to claim 2 , the specifications of the article to be coated include at least the coating area of the article to be coated. To do.

An object to be coated having a small coating area tends to have a thick film due to a large amount of electricity per unit area, but the effective area of the electrode is controlled according to the coating area (specifically, the coating area is By making the effective area of the electrode relatively small with respect to the object to be coated having a small thickness, it is possible to make the film thickness formed on each object to be coated uniform.

Further, as an example of a specification of the object to be coated, claim
In the electrodeposition coating apparatus described in item 3, the specification of the article to be coated includes at least the distance between the article to be coated and the electrode in the tank.

When the distance between the electrodes to be coated and the electrodes is short, the voltage applied per unit area tends to increase and a thick film tends to be formed. The effective area of the electrodes depends on the distance between the electrodes. By controlling (specifically, the effective area of the electrode is made relatively small for the object to be coated with a short distance between the electrodes), the film thickness formed on each object to be coated is made uniform. be able to.

In the electrodeposition coating apparatus of the present invention , the control of the effective area of the electrode may be executed not only according to the specifications of the object to be coated but also according to the site of the object to be coated. For example, when the object to be coated is an automobile body, the electrode effective area of the body vertical surface (fender panel, door outer panel, quarter panel, etc.) that tends to be a thick film relative to the horizontal surface of the body is made relatively small,
As a result, the film thickness can be made uniform between the horizontal surface of the body and the vertical surface.

The electrodeposition coating apparatus of the present invention is mainly applied to full-dip coating of automobile bodies, but it can also be applied to automobile parts coating and the like.

[0027]

According to the present invention, it is possible to locally control the film thickness depending on the site even for an object to be coated which tends to be a thick film or an object to be coated having the same specification. It is possible to make the electrodeposited film thickness uniform between coating objects and over the entire coating object. At the same time, it is possible to suppress cost increase due to excess quality.

Further, the Masking member so disposed within the membrane electrode housing, without risk of malfunction occurs masking member by electrodeposition coating, also the masking material also electrodeposition bath is brought dust by It will not get in. Furthermore, since the masking body is composed of the movable slide plate, it is possible to increase the film thickness by opening the movable slide plate.
On the contrary, the film can be thinned by closing the movable slide plate. Further, by making the open / close position of the movable slide plate continuous, it is possible to control to a desired film thickness.
Especially when the masking body is composed of a movable slide plate,
For example, since the diaphragm electrode can be housed in the case, the space required for the operation of the masking body can be minimized.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 is an overall sectional view showing an electrodeposition coating apparatus of the present invention, FIG. 2 is a sectional view taken along line II-II in FIG. 1, and FIG.
FIG. 1 is a front view showing a first embodiment of a masking body according to the present invention.

The electrodeposition coating apparatus of this embodiment has a long boat-shaped electrodeposition tank 1, and the electrodeposition tank 1 is filled with the electrodeposition coating liquid L.

The car body B which is the object to be coated is a hanger H.
It is continuously loaded at a constant speed by the overhead conveyor C while it is mounted on the body B.
In order to completely submerge the electrodeposition tank C, the overhead conveyor C is inclined downward at about 20 ° to 40 ° on the entry side of the electrodeposition tank 1 and maintains the height at which the body B is completely submerged in the effective range of the electrodeposition tank. On the outlet side, it is inclined upward by about 20 ° to 40 °. In FIG. 1, the left side of the figure is the inlet side and the right side is the outlet side.

The length of the electrodeposition tank 1 within the effective range of the electrodeposition tank, that is, the range in which the body B is completely submerged is set so that the total submersion time of, for example, 3 minutes or more is secured for each vehicle type. When the body B is placed in the bath, in the cationic electrodeposition coating, the electrodeposition coating is applied via the electrodes (only the diaphragm electrode plate 2 on the side surface is shown) arranged on the side wall and the bottom wall of the electrodeposition bath 1. 3 in liquid L
A body B grounded by applying a DC voltage of around 00V (supplied from the power supply device shown in FIG. 1).
Electrophoresis of the paint particles occurs between and, and an electrodeposition coating film is formed on the inner and outer plates of the body B and the inner surface of the bag structure.

An overflow tank T is provided outside the outlet side of the electrodeposition tank 1, and the electrodeposition coating liquid L that has passed over the weir T1 between the electrodeposition tank 1 and the overflow tank T is the overflow. It flows into the tank T. Therefore, the liquid level of the electrodeposition tank 1 is determined by the height of the weir T1.

In the overflow tank T, a suction pump P, a filter F, a heat exchanger E and a plurality of nozzles 3 are provided.
Is provided with a paint circulation system 4 having the following: the electrodeposition paint liquid L in the overflow tank T is sucked by the pump P, filtered by the filter F, adjusted to an appropriate temperature by the heat exchanger E, and then the nozzle 3 Is discharged into the electrodeposition tank 1. The paint circulation system 4 stirs the paint in the electrodeposition tank 1 to prevent the electrodeposition paint liquid L from settling and to make the paint temperature uniform.

FIG. 2 is a sectional view taken along line II-II of FIG. 1. The diaphragm electrode 2 is housed in a diaphragm case 5 arranged along both side walls of the electrodeposition tank 1, and the diaphragm is concerned. The case 5 is filled with pure water. Then, the applied voltage from the diaphragm electrode 2 is applied to the body B through the diaphragm 6 provided on the surface facing the body B.

In particular, in the electrodeposition coating apparatus of this embodiment, as shown in the figure, a masking body 7 is provided inside the diaphragm case 5 and between the diaphragm electrode 2 and the body B. . The masking body 7 is made of, for example, an insulating material such as vinyl chloride or polytetrafluoroethylene, or the surface thereof is coated with the insulating material. It is possible to move to a position where it rises to. The driving means 8 for the masking body 7 is not particularly limited, but, for example, a fluid cylinder or a mechanical lifter can be adopted.

As shown in FIG. 3, the masking body 7 of this embodiment is mainly provided with a masking portion 71 for shielding the central portion of the door panel of the body B, and the other portions above and below are opened. The part 72 is formed. As a result, even if the masking body 7 is dipped in the diaphragm case 5, the voltage from the diaphragm electrode 2 is applied to the portion other than the portion corresponding to the central portion of the door panel through the opening 72.

However, the structure of the masking body 7 shown in FIGS. 2 and 3 is merely an example, and can be appropriately selected according to the vehicle type. In short, it suffices to shield the diaphragm electrode portion corresponding to the portion that tends to be a thick film and provide the opening 72 in the other portion. Further, it is not necessary to provide the masking body 7 for all the diaphragm electrodes 2 provided in the electrodeposition tank 1, and it may be partially provided, or the structure of the masking body 7 to be provided in each diaphragm case 5 is appropriate. It may be configured to.

The vertical movement of the masking body 7 is executed by the driving means 8. The driving means 8 is controlled by the control means 9 so that the vehicle type data from the vehicle type detecting device is inputted. It is connected to the.

The vehicle type detecting device is not particularly limited, but is, for example, a device for detecting a peculiar point of the shape of the body B using a photoelectric tube or the like (for example, arranged immediately before entering the tank), or a production control system. A data reading device or the like can be applied.

Further, the control means 9 has a masking body 7 for each vehicle type data which is experimentally or empirically confirmed.
The appropriate position data is stored in advance as a table, and when the vehicle type data is input from the vehicle type detection device, a control signal is output to the driving means 8 of the masking body 7 based on this memory.

In this case, the plurality of masking bodies 7 can be controlled independently of each other. For example, the pair of facing masking bodies 7, 7 and the adjacent masking body 7 may be commonly controlled.

Next, the operation will be described. The voltage applied to the electrode 2 is set, for example, in accordance with the vehicle type in which it is difficult to secure the electrodeposition film thickness. Usually, it is a large vehicle with a large electrodeposition area. Then, when such a large vehicle is transported, the masking body 7 is taken out of the diaphragm case 5, and electrodeposition coating is applied in a state where there is no shield between the diaphragm electrode 2 and the body B. As a result, an electrodeposition coating film having an appropriate film thickness is formed on a large vehicle according to the set voltage.

In the meantime, when a small car having a small electrodeposition area flows in, a driving signal of the masking body 7 is output from the control means 9 to the driving means 8 based on the vehicle type data, and the small car is continuously conveyed. The masking body 7 is successively dipped in the diaphragm case 5 according to the transportation. With respect to the diaphragm electrode 2 that the small car has passed through, the masking body 7 is sequentially taken out from the diaphragm case 5.

Since a small car or the like has a smaller electrodeposition area, the electrodeposition film thickness tends to be thicker than that of a large car. However, by interposing the masking body 7, the current flowing in the small car is suppressed. , It is possible to suppress such thickening,
The film thickness can be the same as that of large vehicles.

Further, if the masking body 7 as shown in FIG. 3 is used, it is possible to suppress the film thickness of a door panel or the like, which tends to be partially thickened even in the same vehicle type.
It is also possible to make the film thickness of the entire vehicle uniform.

Furthermore, the masking body 7 of this embodiment is
The diaphragm case 5 is not immersed in the electrodeposition tank 1 itself.
Since it is immersed in the inside, it is possible to prevent the electrodeposition coating from adhering to cause malfunction, or to prevent the dust attached to the masking body 7 from being brought into the electrodeposition tank 1.

The masking body 7 according to the present invention is not limited to the above-mentioned ones and can be variously modified and changed. FIG. 4 is a perspective view showing another embodiment of the masking body, and FIGS. 5A and 5B are plan views showing the operation thereof.

In this embodiment, the masking body 7 is composed of a plurality of vertically long strip-shaped insulating plate pieces 73 that are slidably overlapped with each other. It is arranged in between. Then, by the drive means 8 including a fluid cylinder or the like, as shown in FIG.
A closed position that shields most of the diaphragm electrode 2 as shown in FIG.
As shown in FIG. 3B, the diaphragm electrode 2 can be moved to and from an open position where most of the diaphragm electrode 2 is unshielded.

By doing so, as in the above-described embodiment, when a large vehicle is conveyed, the masking body 7 is moved to the position shown in FIG.
As shown in (B), it is opened, and electrodeposition coating is performed in a state where there is no shield between the diaphragm electrode 2 and the body B. As a result, an electrodeposition coating film having an appropriate film thickness is formed on a large vehicle according to the set voltage.

In the meantime, when a small car having a small electrodeposition area flows in, a control signal of the masking body 7 is output from the control means 9 to the drive means 8 based on the vehicle type data, so that a small car continuously conveyed. The masking body 7 is sequentially closed as shown in FIG. With respect to the diaphragm electrode 2 that the small car has passed through, the masking body 7 is sequentially opened.

Since a small car has a small electrodeposition area, the electrodeposition film thickness tends to be thicker than that of a large car. However, by interposing the masking body 7, the electric current flowing in the small car is suppressed. , It is possible to suppress such thickening,
The film thickness can be the same as that of large vehicles.

Further, since the masking body 7 of the present embodiment is not immersed in the electrodeposition tank 1 itself but is disposed inside the diaphragm case 5, the electrodeposition paint adheres to cause malfunctions, or It is possible to prevent dust attached to the masking body 7 from being brought into the electrodeposition tank 1. In particular, since the masking body 7 of the present embodiment is composed of the movable slide plate, it is not necessary to take it out of the diaphragm case 5, and compared with the masking body 7 shown in FIGS. 2 and 3,
A small space is required in the shielded state and the non-shielded state.

The above-described embodiments are described for facilitating the understanding of the present invention, and are not described for limiting the present invention. Therefore, each element disclosed in the above-described embodiment is intended to include all design changes and equivalents within the technical scope of the present invention.

For example, in the masking body 7 shown in FIGS. 4 and 5, the plate piece 73 may be formed in a horizontally long strip shape and the sliding direction may be the vertical direction of the body B. By doing so, it is possible to suppress the increase in the film thickness for each body part of one body.

Further, in the above-mentioned embodiment, the masking body 7 is entirely provided in the diaphragm case 5, but the present invention can be applied to electrodes other than the diaphragm electrode.

[Brief description of drawings]

FIG. 1 is an overall sectional view showing an electrodeposition coating apparatus of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a front view showing an embodiment of a masking body according to the present invention.

FIG. 4 is a perspective view showing another embodiment of the masking body according to the present invention.

FIG. 5 is a plan view showing the embodiment of FIG. 4 ((A) shows a state where the slide plate is closed, and (B) shows a state where the slide plate is open).
Is.

[Explanation of symbols]

1 ... Electrodeposition tank 2 ... Diaphragm electrode (electrode) 3 ... Nozzle 4 ... Paint circulation system 5 ... Diaphragm case 6 ... diaphragm 7 ... Masking body 71 ... Masking section 72 ... Opening 73 ... Board piece 8 ... Driving means 9 ... Control means

─────────────────────────────────────────────────── --Continued front page (56) References JP-A-9-31691 (JP, A) JP-A-7-150392 (JP, A) JP-A-5-78898 (JP, A) Actual development Sho-63- 110576 (JP, U) (58) Fields surveyed (Int.Cl. ⁷ , DB name) C25D 13/22 B62D 65/00 C25D 13/00 305

Claims (3)

(57) [Claims] 1. An electrodeposition coating apparatus for immersing an object to be coated in an electrodeposition coating solution filled in an electrodeposition tank, a diaphragm electrode disposed in the electrodeposition tank, the electrode and the object to be coated. In the case of the diaphragm electrode between
Is provided on the diaphragm electrode and is composed of a plurality of insulating plate pieces.
Most of the diaphragm electrode and most of the diaphragm electrode open
Insulating masking body composed of a movable slide plate provided so as to be continuously movable between an open position where it is not shielded, and the above-mentioned masking machine according to the specification and / or site of the object to be coated.
Of the shielded or unshielded area of the electrode
An electrodeposition coating apparatus comprising: a control means for controlling one side at least . Wherein said in the specification of the object to be coated, <br/> electrodeposition coating device according to claim 1, characterized in that includes painting area of at least the article to be coated. The specifications wherein the object to be coated, electrodeposition coating device according to claim 1, characterized in that includes the distance between the article to be coated and the electrode in at least the bath.