JPS6365760B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrodeposition coating apparatus in which an electrodeposition tank is provided with a hanger for placing an object to be coated immersed in an electrodeposition coating liquid. .

[Conventional technology]

This type of electrodeposition coating equipment places the ionized paint components in the electrodeposition tank on a hanger installed in the electrodeposition tank, and deposits them as a resin on the surface of the object to be coated, which is charged to the opposite polarity. This method performs electrodeposition coating, and is used for metal coating of automobile bodies and frames.

Fig. 1 is a schematic diagram showing a conventional example of this type of electrocoating. It's a tank.

Electrodeposition paint liquid overflowing from the tank body 2 into the sub-tank 3 is constantly fed from the sub-tank 3 to the tank body 2 by a pump P interposed in a paint liquid circulation pipe 4 connected between the two.
After being injected from the injection nozzles 6, 6, . . . of the riser pipe 5 disposed at the bottom of the tank body 2, it overflows and is circulated through a path that returns to the sub-tank 3.

Further, in the tank body 2 of the electrodeposition tank 1, there is provided a hanger H on which the object 7 to be coated immersed in the electrodeposition coating liquid is placed.

Note that this hanger H has an energizing bar (not shown) that energizes the object to be coated 7 placed thereon.

By the way, when the object 7 to be coated is placed on the hanger H provided in the tank body 2 of the electrodeposition tank 1 and subjected to electrodeposition coating, the object 7 to be coated is vertically placed from above the electrodeposition tank 1. Since the object to be coated 7 is lowered and immersed in the tank body 2, air bubbles are likely to adhere to the lower surface of the object to be coated 7 submerged in the electrodeposited paint liquid in the tank body 2, and the lower surface of the object to be coated 7 is particularly uneven. In some cases, very large air bubbles called air pockets are attached.

If electrodeposition coating is performed in this state, there is a risk that uneven coating will occur because the paint will not be electrodeposited on the areas where the bubbles are attached.

For this reason, in the past, for example,
As disclosed in Publication No. 174596, a horizontal rod supported by cylinders at both ends is placed horizontally above the electrodeposition tank, and the object to be coated is suspended from the horizontal rod with a chain to be placed in the electrodeposition paint solution. A hanger that is immersed in water has been proposed.

In other words, a hanger for suspending the object to be coated is provided above the electrodeposition tank rather than inside the electrodeposition tank.

According to this, when cylinders that support both ends of a horizontal rod are alternately expanded and contracted to alternately raise and lower both ends of the horizontal rod, the object to be coated suspended from the horizontal rod is shaken in the electrocoating liquid. Since the air bubbles attached to the lower surface side are moved by the movement, it is possible to prevent uneven coating from occurring.

[Problem to be solved by the invention]

However, in this case, the object to be coated, which is suspended by a chain from the horizontal rod, swings considerably and hits the side wall of the electrodeposition tank or the diaphragm electrode installed along the side wall, resulting in damage. There is a risk that this may occur.

Further, since the entire load of the object to be coated is directly supported by the cylinder, there is a drawback that the cylinder becomes significantly large and equipment costs increase.

Furthermore, the work of hanging the object to be coated on the chain and removing it from the chain is extremely troublesome, and there is also the drawback that the object to be coated cannot be quickly transported from the electrodeposition bath.

Therefore, the present invention is not a method in which the object to be coated is suspended from a hanger provided above the electrodeposition tank and immersed in the electrodeposition tank, but a method in which the object to be coated is placed on a hanger provided in the electrodeposition tank. By adopting a The technical problem is to prevent uneven coating by moving or removing air bubbles adhering to the lower surface of the hanger, and to also enable the power of the drive source for swinging the hanger to be extremely small.

[Means to solve the problem]

In order to solve this problem, the present invention provides an electrodeposition coating apparatus in which a hanger for placing an object to be coated immersed in an electrodeposition coating liquid is provided in an electrodeposition tank.
The hanger includes a frame on which the object to be coated is placed, a pair of support arm members erected on both left and right sides of the central portion of the frame, and a pair of support arm members that suspend and support the upper ends of each of the support arm members on the left and right side walls of the electrodeposition bath. and a swing shaft, and the frame body is connected to a drive source for swinging the hanger in the front and back direction via a swing arm member provided at either the front or rear end of the frame body. do.

[Effect]

According to the present invention, since the object to be coated to be immersed in the electrodeposition paint liquid in the electrodeposition tank is placed on the frame of a hanger provided in the electrodeposition tank, the coating inside the electrodeposition tank is Painted objects can be carried in and out extremely quickly and easily.

In addition, the frame of the hanger is connected to a pair of support arm members erected on both left and right sides of the center portion of the frame by a drive source connected via a swing arm member provided at either the front or rear end of the hanger frame. Since the upper end can be swung back and forth using the swing shaft as a fulcrum, air bubbles attached to the underside of the object to be painted are moved or removed without stopping in one place, preventing uneven coating. .

In addition, since the hanger is firmly suspended from the left and right side walls of the electrodeposition bath by swing shafts on both sides of the central part of the frame, it swings horizontally and moves along the side walls inside the electrodeposition bath or along the side walls. There is no need to worry about damaging the installed diaphragm electrode, etc.

Furthermore, since the hanger swings back and forth using the swing shaft that suspends and supports both left and right sides of the center portion of the frame as a fulcrum, the power of the drive source for swinging the hanger can be extremely small.

〔Example〕

Embodiments of the present invention will be specifically described below based on the drawings.

FIG. 2 is a longitudinal cross-sectional view showing an example of an electrodeposition coating apparatus according to the present invention, FIG. 3 is a plan view, and FIG. 4 is a cross-sectional view.

Note that parts common to those in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

In this example, the hanger H provided in the tank body 2 of the electrodeposition tank 1 is adapted to the size of the object 7 to be coated, such as an automobile frame, to be immersed in the electrodeposition paint liquid in the tank body 2. Framed rectangular frame 10
, a pair of support arm members 11 , 11 erected on both left and right sides of the central portion of the frame 10 , and a pair of swing shafts that suspend and support the upper ends of the support arm members 11 on the left and right side walls of the electrodeposition bath 1 . 12, 12.

The swing shafts 12, 12 extend horizontally toward the side wall of the electrodeposition tank 1, and their extended ends are rotatably supported by bearings 13, 13 fixed to the upper part of the side wall of the electrodeposition tank 1, respectively. has been done.

Reference numeral 14 denotes a hydraulic cylinder as a driving source for swinging the hanger H in the front-rear direction (left-right direction as seen in FIG. 2), and is fixed to the outer wall of the electrodeposition tank 1 on the side in which the hanger H swings. It is supported by a bracket 14a so as to be rotatable back and forth as the hanger H swings, and the rod head of the piston rod 15 is rotatably engaged with a connecting member 16, which will be described later.

Reference numeral 17 denotes an L-shaped swinging arm member whose lower end is fixed to the center of the front end of the frame 10 on the side of the hydraulic cylinder 14 and whose upper end is fixed to a connecting member 16 that engages with the piston rod 15.

The frame 10 of the hanger H is provided with contact electrodes 18, 18 that serve as energizing bars for grounding the object 7 placed thereon.

Each contact electrode 18 consists of a top plate part 19 that is brought into contact with the object 7 to be coated, and a spring 20 that elastically supports the top plate part 19. It is designed to turn on electricity only when

Moreover, 21 and 22 are a diaphragm electrode and a bottom electrode installed along the side wall and bottom of the tank body 2, respectively, and are connected to opposite poles of the contact electrodes 18 and 18.

23 indicates diaphragm electrodes 21 and 21 adjacent to each other.
A protector is disposed between the diaphragm electrode 21 and the diaphragm electrode 21 to prevent the object 7 from coming into contact with the diaphragm electrode 21.

The above is an example of the structure of the electrodeposition coating apparatus according to the present invention, and the operation and effect thereof will be explained next.

First, the object to be coated 7 is vertically lowered from above the electrodeposition tank 1 and immersed in the electrodeposition paint liquid in the tank body 2, and placed on the frame 10 of the hanger H provided in the tank body 2. will be placed on.

As a result, the object 7 to be coated comes into contact with the top plate 19 of the contact electrode 18 provided on the frame 10 and becomes grounded, and in this state, electricity is applied to the diaphragm electrode 21 and the bottom electrode 22 to perform electrodeposition. Painting begins.

At the same time, the hydraulic cylinder 14 is activated and its piston rod 15 is expanded and retracted, and the connecting member 16 provided at the tip of the piston rod 15 moves up and down, causing a oscillator rotatably supported by the connecting member 16 to move up and down. The movable arm member 17 causes the hanger H to swing back and forth about the swing shafts 12, 12, and both front and rear ends of the frame 10 on which the object to be coated 7 is mounted alternately move up and down.

As a result, the air bubbles adhering to the lower surface of the object to be painted 7 move, or some of them completely escape from the lower surface.

Therefore, even if air bubbles adhere to the bottom surface of the object to be coated 7 when the object to be coated 7 is immersed in the electrodeposition paint liquid, the air bubbles attached to the bottom surface of the object 7 do not constantly move during electrodeposition coating. Since the coating is removed from the bottom surface, uneven coating due to the adhesion of air bubbles is reliably prevented.

Further, the hanger H, which can carry the object 7 to be coated and swing back and forth, is securely hung on the left and right side walls of the electrodeposition bath 1 by swing shafts 12, 12 at both left and right sides of the center part of the frame body 10. Since it is supported, there is no fear that it will sway and damage the side wall inside the electrodeposition tank 1 or the diaphragm electrode 21 installed along the side wall.

Furthermore, since the hanger H is balanced by suspending and supporting the left and right sides of the central part of the frame 10 on which the object 7 to be coated is placed by swing shafts 12, 12, the hanger H is balanced. Only one cylinder 14, which is relatively small and has a small driving force, can be used, and the equipment cost is very low.

Note that the frame 10, whose left and right sides at the center are suspended and supported by swing shafts 12, 12, is supported at its front end by a swing arm member 17 connected to a hydraulic cylinder 14 via a connection member 16. , this will not hit the bottom electrode 22 or the riser pipe 5 and cause damage.

When the electrodeposition coating is completed, the drive of the hydraulic cylinder 14 is stopped, the swinging of the hanger H is stopped, and the object to be coated 7 is lifted above the tank body 2 and carried out of the electrodeposition tank 1.

In this way, if the object to be coated 7 to be immersed in the electrocoating liquid in the tank body 2 is placed on the frame 10 of the hanger H provided in the tank body 2, The work of carrying in and out the object 7 to be coated can be carried out extremely quickly and easily.

In addition, in the above-mentioned embodiment, a case was explained in which the hydraulic cylinder 14 was used as a drive source for swinging the hanger H, but the present invention is not limited to this, and for example, the swing shaft 12 may be driven by a motor or other drive source. It may also be something that is held and rotated.

Further, the hydraulic cylinder 14 is configured to operate in conjunction with the contact electrode 18, and the object to be coated 7 is connected to the contact electrode 18.
It may be configured to operate only while in contact with.

Furthermore, the hanger H does not need to be constantly oscillated during electrodeposition coating, but may be oscillated only once, or may be oscillated several times intermittently at appropriate time intervals. It may be.

〔Effect of the invention〕

As described above, according to the present invention, the object to be coated to be immersed in the electrodeposition paint liquid in the electrodeposition tank is placed on the frame of the hanger provided in the electrodeposition tank and is swung. Because of this structure, it is possible to move or remove air bubbles attached to the bottom surface of the object to be coated, thereby preventing uneven coating, and at the same time, it is possible to carry the object to be coated into and out of the electrodeposition tank extremely quickly and easily. The effect is that it can be done.

Furthermore, there is no need to worry about the side walls of the electrocoating bath or the electrodes installed along the side walls being damaged by the swinging hanger holding the object to be coated, and the drive source for swinging the hanger. This has the very advantageous effect of requiring only a very small amount of power.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view schematically showing a conventional electrodeposition coating device, FIG. 2 is a longitudinal cross-sectional view showing an example of an electrodeposition coating device according to the present invention, FIG. 3 is a plan view thereof, and FIG. 4 is a cross-sectional view. It is a front view. Explanation of symbols, 1...electrodeposition tank, 2...tank body, 3...subtank, 7...object to be coated, H...
Hanger, 10... Frame body, 11... Support arm member, 1
2... Swing shaft, 14... Hydraulic cylinder (drive source),
17... Swinging arm member.

Claims (1)

[Claims] 1. In an electrodeposition coating apparatus in which a hanger is provided in an electrodeposition bath to place a workpiece immersed in an electrodeposition paint liquid, the hanger includes a frame body on which the workpiece is placed, and a frame body on which the workpiece is placed. Consisting of a pair of support arm members erected on both left and right sides of the central portion, and a pair of swing shafts that suspend and support the upper ends of each support arm member on the left and right side walls of the electrodeposition tank,
An electrodeposition coating apparatus characterized in that the frame body is connected to a drive source that swings the hanger in the front and back direction via a swing arm member provided at one end of the frame body.