JP2013043995A - Electrodeposition coating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrodeposition coating method, by which each member and a vehicle body are simultaneously coated and they are coated with an appropriate film thickness.SOLUTION: The electrodeposition coating method for a radiator support lower 1 uses an electrodeposition coating apparatus including an electrodeposition tank for storing an electrodeposition liquid, at least one pair of side electrodes oppositely arranged with an interval in the electrodeposition tank, and a bottom electrode. In the method, the radiator support lower 1 is arranged in an engine room 10 of a vehicle body 2, which is partitioned by side members arranged on both sides in the vehicle width direction and a hood 13 for closing a space between upper ends of the both side members (arrangement process), and then, the vehicle body in which the radiator support lower 1 is arranged in the engine room 10 is immersed in the electrodeposition tank from the front side so that the vehicle body may pass through between the both side electrodes and the bottom electrode (electrodeposition coating step).

Description

  The present invention relates to an electrodeposition coating method for electrodeposition coating by immersing vehicle parts in an electrodeposition tank.

  Conventionally, automobiles are manufactured by assembling a plurality of members to a vehicle body (vehicle main member) from the viewpoints of manufacturability, designability, practicality, etc., and each of these members is further combined with a plurality of independent parts. It is also known to form by a combination of these.

  Specifically, for example, left and right side members extending in the vehicle front-rear direction, a radiator support coupled to the front end portion of each side member, and an up-down direction disposed behind each radiator support of each side member A front pillar that extends to the front pillar, a rear end portion of which is coupled to each front pillar, each apron member that extends forward from the front pillar, and a hood that is disposed to cover the top of each apron member and the radiator support. The front car body is known.

  Further, the radiator support is mounted between, for example, a side member extending in the vehicle vertical direction, a lower member extending in the vehicle width direction coupled between the lower ends of the side members, and an upper end of each side member. It has been known to form an upper member extending in the vehicle width direction that has been passed and joined together in a substantially rectangular shape (see, for example, Patent Document 1).

  Further, in an automobile, the vehicle body and the assembly member are usually electrodeposited in a state before assembly. As a coating apparatus for such electrodeposition coating, for example, an electrodeposition liquid is stored. A deposition tank, a conveying means for sequentially conveying a plurality of objects to be coated in the electrodeposition tank for a certain distance, and a facing means to be coated in the electrodeposition tank. In addition, there has been proposed an electrodeposition coating apparatus including a plurality of electrodes provided so as to be movable in a direction opposite to the object to be coated according to the size of the object to be coated (see, for example, Patent Document 2). .)

JP 2009-234336 A JP 2002-69697 A

  On the other hand, the vehicle body and each member need to be coated with an appropriate film thickness. Specifically, for example, a thick coating member (for example, a film thickness of 20 μm or more) to be applied thickly, and a thin coating member to be coated thinly. (For example, a film thickness of 10 to 15 μm), and an intermediate member (for example, a film thickness of 15 to 20 μm) for applying a paint to an intermediate thickness between them.

  However, for example, when a member corresponding to the intermediate member and the vehicle body are simultaneously electrodeposited by the electrodeposition coating method described in Patent Document 2, the coating film thickness of each member becomes excessively thick (for example, a thick coating member). The paint cost is high.

  On the other hand, when such a member is placed in a closed space, for example, a box or the like and electrodeposition-coated, the applied voltage is shielded, so that the coating film thickness of each member becomes excessively thin (for example, There is a problem that a desired coating film cannot be obtained.

  Accordingly, an object of the present invention is to provide an electrodeposition coating method capable of coating each member and the vehicle body at the same time and coating them with an appropriate film thickness.

  In order to achieve the above object, the present invention provides an electrodeposition coating apparatus comprising an electrodeposition tank in which an electrodeposition liquid is stored and at least one pair of electrodes disposed to face each other at an interval in the electrodeposition tank. In the front part structure of the vehicle body defined by a side member disposed on both sides in the vehicle width direction and a hood that closes between the upper ends of both side members, An arrangement step of arranging vehicle parts, and an electrodeposition coating step of immersing the vehicle body in which the vehicle parts are arranged in the front structure into the electrodeposition tank from the front side so as to pass between both the electrodes. It is characterized by including.

  According to the present invention, in the front structure of the vehicle body defined by the side members disposed on both sides in the vehicle width direction and the hood that closes the upper ends of both side members, that is, the front side in the vehicle front-rear direction, and Vehicle parts are arranged in the front structure with the lower side in the vehicle vertical direction open, and the vehicle parts are immersed in the electrodeposition tank from the front side and electrodeposition coated in the state where the vehicle parts are arranged in the front structure. .

  In this electrodeposition coating, the applied voltage is appropriately cut off by the side member and the hood, and the electrodeposition liquid containing the electrodeposition paint penetrates into the front structure from the open portion on the front side. Then, the electrodeposition liquid is discharged from the front structure through the lower open portion while dipping the vehicle part in the front structure and electrodepositing the vehicle part.

  Therefore, in such a method, with an appropriate applied voltage and the flow of the electrodeposition liquid, for example, with a moderate film thickness that is thinner than that applied outside the structure and thicker than that applied in a closed space, for example. Vehicle parts can be electrodeposited.

FIG. 1 is a perspective view of a radiator support lower as viewed from the front upper side. FIG. 2 is a side view showing a state in which the radiator support lower is disposed in the engine room. FIG. 3 is a front view of FIG. FIG. 4 is an explanatory view for explaining the electrodeposition coating process, and is a side view of the electrodeposition coating apparatus. FIG. 5 is a front view of FIG.

  FIG. 1 is a perspective view of a radiator support lower as viewed from the front upper side.

  In the electrodeposition coating method of the present invention, a radiator support lower (a lower member of the radiator support) 1 as a vehicle part is electrodeposited by an electrodeposition coating apparatus 21 described later.

  The radiator support lower 1 is a lower member of a radiator support (not shown) formed in a substantially frame shape, and as shown in FIG. 1, as a metal member having a substantially U-shaped cross-sectional view extending in the longitudinal direction, Is formed.

  Specifically, the radiator support lower 1 is formed with a predetermined thickness in a side view, and is formed in a curved shape that gradually increases toward both ends in the longitudinal direction. A plurality of (for example, two) support portions 4 are provided.

  The support portion 4 is provided on the radiator support lower 1 to fix a radiator (not shown), and is formed, for example, in the vicinity of the central portion in the longitudinal direction and the vicinity of one end portion in the longitudinal direction. ing.

  The radiator support lower 1 includes a plurality of (for example, five) through holes 5.

  Specifically, the plurality of (for example, five) through holes 5 are formed as substantially circular holes in plan view that penetrate the radiator support lower 1 in the thickness direction, and sequentially follow the longitudinal direction of the radiator support lower 1. Has been placed.

  Further, attachment portions 6 are formed at both ends in the longitudinal direction of the radiator support lower 1.

  Such a radiator support lower 1 is used for assembling a radiator support (not shown) after being electrodeposited simultaneously with the vehicle body 2 (see FIG. 2).

  Specifically, a side member (not shown) of a radiator support (not shown) is attached to each mounting portion 6 described above, and a radiator support (not shown) is further attached to the side member (not shown). ) Upper member (not shown) is attached to form a substantially frame-shaped radiator support (not shown) (see, for example, JP 2009-234336 A). In addition, the obtained radiator support (not shown) is assembled | attached to the vehicle body 2 (refer FIG. 2).

  FIG. 2 is a side view showing a state in which the radiator support lower is arranged in the engine room, and FIG. 3 is a front view in FIG. In FIG. 2, a side member 11 described later is omitted.

  Although not shown in detail, the vehicle body 2 includes an outer panel such as a roof panel, a hood panel, a front fender panel, and a rear fender panel, and forms an outer shape of an automobile.

  Such a vehicle body 2 includes an engine room 10 as a front structure, as shown in FIG.

  The engine room 10 of the vehicle body 2 is an internal space defined by a pair of side members 11 disposed on both sides of the vehicle body 2 in the vehicle width direction and a hood 13 that closes between the upper end portions 12 of the side members 11. Thus, the vehicle vertical direction lower side (vehicle height direction bottom side) is opened, and the vehicle front-rear direction front side is opened.

  The engine room 10 is provided with locking portions (not shown) on both sides in the vehicle width direction, and the radiator support lower 1 can be accommodated and fixed therein.

  The vehicle body 2 includes a front frame 15 having a substantially frame shape in front view on the front side in the front-rear direction, and extends in the vertical direction so as to span the front frame 15 in the vertical direction (the vehicle height direction). The front frame 15 is reinforced by this.

  And in order to paint such a vehicle body 2 and the radiator support lower 1, one Embodiment of the electrodeposition coating method of this invention is employ | adopted.

  That is, in this method, first, as shown in FIGS. 2 and 3, the radiator support lower 1 is disposed in the engine room 10 as the front structure of the vehicle body 2 (arrangement step).

  Specifically, the radiator support lower 1 is housed in the engine room 10 and is fixed in the engine room 10 by engaging portions (not shown) provided on both sides in the vehicle width direction.

  At this time, the radiator support lower 1 is fixed in the engine room 10 in which the lower side in the vertical direction (bottom side in the vehicle height direction) and the front side in the front-rear direction are opened, and the lower surface and the front surface thereof are exposed to the outside. ing.

  In this method, the vehicle body 2 in which the radiator support lower 1 is disposed in the engine room 10 is then electrodeposited (electrodeposition coating process).

  FIG. 4 is an explanatory view for explaining the electrodeposition coating process, and is a side view of the electrodeposition coating apparatus, and FIG. 5 is a front view of FIG.

  In the electrodeposition coating, as shown in FIG. 4, an electrodeposition tank 23 in which an electrodeposition liquid 22 containing an electrodeposition paint is stored and an electrodeposition tank 23 facing each other at an interval are disposed in the electrodeposition tank 23. An electrodeposition coating apparatus 21 having a pair of side electrodes 37 and a bottom electrode 38 is used.

  Hereinafter, this electrodeposition coating apparatus will be described with reference to FIGS. 4 and 5. In FIG. 4, this electrodeposition coating apparatus 21 immerses the electrodeposition tank 23 in which the electrodeposition liquid 22 is stored, and the vehicle body 2 and the radiator support lower 1 as the objects to be coated in the electrodeposition tank 23 for a certain distance. However, a transport unit 25 for transporting sequentially and an electrodeposition unit 26 for electrodeposition coating on the vehicle body 2 and the radiator support lower 1 in the electrodeposition tank 23 are provided.

  As shown in FIG. 5, the electrodeposition tank 23 is formed by a bottom wall 27 and two side walls 28 that stand up from both side ends of the bottom wall 27. As shown in FIG. 4, An inlet side portion 30 whose wall 27 is inclined downward, an outlet side portion 31 whose bottom wall 27 is inclined upward, and a flat central portion 32 between the inlet side portion 30 and the outlet side portion 31 are provided. Yes. In this electrodeposition tank 23, about 4 to 6 units can be immersed along the longitudinal direction of the vehicle body 2 (and the radiator support lower 1 accommodated in the engine room 10). It is formed as a large size.

  As shown in FIG. 4, the transport unit 25 has a conveyor 33 disposed above the electrodeposition tank 23 in parallel with the bottom wall 27 along the longitudinal direction of the electrodeposition tank 23, and a predetermined And a plurality of hangers 34 that are suspended at the same pitch. As shown in FIG. 5, each hanger 34 includes a holder 35 that holds the vehicle body 2 in a sandwiched manner from the bottom surface.

  Then, as shown in FIG. 4, each vehicle body 2 is received from the inlet side portion 30 of the electrodeposition bath 23 by the drive of the conveyor 33 while being held by the holder 35 of each hanger 34, and the central portion 32. After being immersed in the electrodeposition liquid 22, the tank is sequentially discharged from the outlet side portion 31.

  Further, as shown in FIGS. 4 and 5, the electrodeposition unit 26 includes a power supply rail 36 disposed along the conveyor 33, a side electrode 37 and a bottom electrode 38 provided in the electrodeposition tank 23, A power supply 39 connected to the power supply rail 36, the side electrode 37, and the bottom electrode 38 is provided. The power supply rail 36 is connected to each hanger 34 and to the cathode 40 of the power source 39.

  In addition, a plurality of side electrodes 37 are arranged at predetermined intervals along the longitudinal direction of the electrodeposition tank 23, and are arranged so as to face the vehicle body 2 in the electrodeposition tank 23 on both sides. Has been. Similarly, a plurality of bottom electrodes 38 are arranged at predetermined intervals along the longitudinal direction of the electrodeposition tank 23, and are arranged to face the vehicle body 2 in the electrodeposition tank 23 below. . The side electrode 37 and the bottom electrode 38 are connected to the anode 41 of the power source 39.

  Then, as described above, by driving the conveyor 33, each vehicle body 2 (and the radiator support lower 1) enters from the entrance side portion 30 of the electrodeposition bath 23 and passes between the side electrodes 37 and the bottom electrode 38. As such, the electrodeposition bath 23 is immersed from the front side. At this time, a negative voltage is applied from the cathode 40 of the power supply 39 to each vehicle body 2 and each radiator support lower 1 via the power supply rail 36 and each hanger 34, and each side electrode 37 is supplied from the anode 41 of the power supply 39. When a positive voltage is applied to each bottom electrode 38, the paint in the electrodeposition liquid 22 is charged, and it adheres to the painted surface of each vehicle body 2 and each radiator support lower 1 to form a coating film. As a result, electrodeposition is applied.

  Specifically, the vehicle body 2 is immersed in the electrodeposition liquid 22 in the electrodeposition tank 23, and the electrodeposition liquid 22 enters the engine room 10 from an open portion on the front side of the vehicle body 2. Then, the electrodeposition liquid 22 is discharged from the engine room 10 through the lower open portion while the radiator support lower 1 is immersed in the engine room 10 and the radiator support lower 1 is electrodeposited. The

  In such electrodeposition coating, each member needs to be coated with an appropriate film thickness. Specifically, for example, a thick coating member (for example, a film thickness of 20 μm or more) to be applied thickly, and a paint to be thinly applied. It is classified into a thin coating member (for example, a film thickness of 10 μm to 15 μm) to be applied, and an intermediate member (for example, a film thickness of 15 to 20 μm) for coating the intermediate thickness between them.

  For example, the car body 2 is coated with a thick paint (for example, a film thickness of 20 μm or more), while the radiator support lower 1 is coated with a paint at a middle thickness (for example, a film thickness of 15 to 20 μm). In this case, for example, when the radiator support lower 1 is immersed in the electrodeposition liquid 22 without being accommodated in the vehicle body 2 and a negative voltage is applied, the applied voltage is not shielded. There is a problem in that the coating material is excessively deposited on the surface to be coated of the radiator support lower 1, and the coating film becomes excessively thick.

  On the other hand, for example, in the case where the radiator support lower 1 is electrodeposited as described above in a closed space where no open surface exists, for example, in the vehicle interior of the vehicle body 2, the applied voltage is excessively high. Since it is shielded, there is a problem that the coating amount of the paint on the surface to be coated of the radiator support lower 1 is reduced and the film thickness of the coating film becomes excessively thin.

  On the other hand, in the above-described method, the vehicle is partitioned by the side members 11 disposed on both sides in the vehicle width direction and the hood 13 that closes the upper end portions of the side members 11, and the lower side in the vertical direction (vehicle In the state where the radiator support lower 1 is disposed in the engine room 10 and the radiator support lower 1 is disposed in the engine room 10 in the engine room 10 in which the bottom side in the high direction is opened and the front side in the front-rear direction is opened. Painted.

  Therefore, in this state, when a negative voltage is applied to the radiator support lower 1 as described above, the applied voltage is appropriately shielded by the side member 11 and the hood 13. Further, as described above, the electrodeposition liquid 22 enters the engine room 10 from the open portion on the front side, and the radiator support lower 1 is immersed in the engine room 10 so that the radiator support lower 1 is electrodeposited. However, it is discharged from the engine room 10 through the lower open portion.

  Therefore, the paint in the charged electrodeposition liquid 22 is appropriately adhered onto the surface to be coated of the radiator support lower 1, and a coating film having an appropriate film thickness is formed.

  Therefore, according to such a method, for example, it is thinner than painting outside the engine room 10, and, for example, painting is performed in a structure in which both sides in the vehicle width direction and both sides in the vertical direction of the vehicle body are partitioned, for example, in the passenger compartment. The radiator support lower 1 can be electrodeposited with a thicker and more appropriate film thickness.

  In the above description, the radiator support lower 1 is used as the vehicle member, but the present invention is not limited to this, and various members can be used as the vehicle member. In the above description, the engine room 10 is used as the front structure of the vehicle body. However, the present invention is not limited to this, and the front structure includes a front side in the vehicle front-rear direction and a lower side in the vehicle vertical direction. Various internal spaces with open sides can be adopted.

DESCRIPTION OF SYMBOLS 1 Radiator support lower 2 Car body 10 Engine room 13 Hood 14 Support member

Claims (1)

An electrodeposition coating method for a vehicle member using an electrodeposition coating apparatus comprising: an electrodeposition tank in which an electrodeposition liquid is stored; and at least one pair of electrodes disposed opposite to each other in the electrodeposition tank. And
An arrangement step of arranging the vehicle parts in a front structure of a vehicle body defined by side members arranged on both sides in the vehicle width direction and a hood that closes between upper ends of both side members;
An electrodeposition coating step of immersing the vehicle body in which the vehicle parts are arranged in the front structure from the front side into the electrodeposition tank so as to pass between both the electrodes. Electrodeposition painting method.

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