JPS59100069A - Sealing method of car body - Google Patents

Abstract

PURPOSE:To mechanically effect the coating process of a car body seal, by a method wherein a sealer is linearly injected under a high pressure as a distance is left between a coating gun and a steel plate joint. CONSTITUTION:When a car body 1 is moved and stationed in front of a work robot 2, the robot 2 is operated in response to a given signal, and a coating gun 3 is actuated along the seam of a steel plate joint according to a stored program. In which case, a body sealer is supplied to the gun 3 through a high pressure hose 5 with the aid of a high pressure pump 4, and is injected through the forward end thereof. A nozzle head having one or more injection nozzles is used as a nozzle head mounted to the forward end of the coating gun.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for sealing an automobile body, more specifically, a method for automatically applying a sealing material to seal joints of steel plates of an automobile body in a watertight and airtight manner. This invention relates to a method for sealing an automobile body, using a coating gun equipped with a specific nozzle head and spraying a sealer while maintaining a constant distance between the sealer application part of the steel plate joint and the coating gun.

The automobile industry is actively trying to mechanize and automate work by introducing robots in production lines, and robots have already been introduced in processes such as assembly and welding of steel plate joints. By the way, even in the painting process, which is one of the processes in the production line, there is a need to automate the painting process in order to streamline productivity and prevent the effects of organic solvents on the human body, so robotization is actively being promoted. However, the application of adhesives, sealants, etc. requires dot or linear application, and the panel joining structures are complex and diverse, making robotization difficult and sufficient automation has not yet been achieved. do not have.

When assembling and joining heavy-duty steel plates, in general, prior to assembly and welding, spot weld sealer is applied in advance to the joints of the steel plates in areas that cannot be filled or injected in later processes. There are also dust sealers and body sealers that can be used to seal all the gaps left after joining steel plates, or to correct the level difference in the seams of outer panels.

1) The latter body sealer is injected into the gaps during the painting process to ensure close contact, and at the same time corrects uneven build-up, smoothes the surface, and perfects the sealing effect. In addition to objective 1 and 1, it is also necessary to improve the appearance finish, and for this purpose, the paint is gelled by heating in a baking curing oven, and has weather resistance, cold resistance, water resistance, vibration resistance, and adhesion to adherends. In addition to having good adhesion to steel plates, chemically treated surfaces, electrodeposition coatings, and other paint-applied surfaces, it also has excellent paint finish and excellent workability (dispensing performance, brush-coated surfaces, etc.). Correctability and wipeability) are required.

Polyvinyl chloride-based plastisol sealers are currently widely used as body sealers with such characteristics. The present invention relates to improving the sealing method by applying such a body sealer, and provides an automatic method for applying a body sealer using a working robot.

Conventionally, such a body sealer has been applied using a flow gun as shown in FIG. 1 by manually or manually discharging the sealer onto the joint portion of the steel plates, and correction with a brush is sometimes performed. That is, the high-pressure extrusion pump ( ) extrudes the sealer at high pressure and passes through the high-pressure hose (2) to
- Hold the sealer supplied to the gun (3) and adjust the discharge appropriately by operating the handle (4'): Con!・While using J-ru, the pipe (5) at the tip of the pipe (5) is discharged and applied along the joint of the steel plate.The pipe (5) used in this method is
The diameter is approximately 5,000 μm, and the diameter of the vibro is appropriately determined by the size of the portion to be sealed and the size of the sealer. This manual application method is difficult to adapt to the high-speed movement of automobile production assembly lines, and also
Coating the joints of many steel plates, including the outer panels, requires a large amount of manual labor, which poses productivity problems, and furthermore, there are problems with watertight and airtight sealing due to variations in work.

1: In order to eliminate the drawbacks of iEl, the application of pressure pump units and automatic application robots to the dispensing and application of body sealer to the steel plate joints is being considered, but L
In addition to being crowded and sandwiched between joints, the joints have a complex and diverse shape with large steps and bends, making it difficult to apply sealer widely and thickly, making it inefficient and inefficient. It has not been put into practical use due to economic difficulties. In addition, as an improvement on this, it has been proposed to use a spray gun equipped with a flat rectangular cross-shaped application nozzle head (Utility Model Application Publication No. 56-133363). Il
′! However, sufficient sealer application has not yet been achieved for sealing parts such as steel plate joints that have a three-dimensional structure. Another method used is to attach a brush to the tip of the nozzle of a pressure gun and spread the sealer in a wide area at the same time as applying the sealer, but this method does not allow for sufficient spread in areas with complex structures that require high precision. However, due to problems with sealing properties, manual corrections are required after application, and full automation using robots has not yet been achieved.

Under these circumstances, the inventors of the present invention conducted various research in order to achieve a completely automated sealing method by introducing work robots in the body sealer application process on the automobile body production line. , a specific nozzle head is installed at the tip of the coating gun attached to the work robot,
By spraying seawater in a line at high pressure and applying it in a strip while maintaining a constant distance between the coating gun and the joint of the steel plates, the inventors completed the present invention. There's only one thing you can do.

That is, the present invention provides a method for applying a body sealer to the joints of steel plates of small bodies in an automobile production line to seal the car body, which includes a coating gun mounted on a working robot and one or more injection jets. Using a coating gun equipped with a nozzle head with holes, spray one sealer in a line at a height of 11E while maintaining a distance between the coating gun and the steel plate joint to form a band on the joint. The present invention provides a method for sealing an automobile interior body in which a coating process is performed mechanically by coating.

The sealing method of the present invention will be explained in more detail with reference to the drawings.

FIG. 2 is a schematic perspective view showing a specific example of an apparatus for painting the steel plate joints of an automatic tonnage Φ body using a working robot according to the present invention, and FIG. 3 is a schematic perspective view of a coating gun used. Schematic cross-sectional views of the head nozzle attached to the tip, FIGS. 4A, B, and C are cross-sectional views taken along the line A-A in FIG. show.

@Figure 2? As shown in the figure, when the heavy vehicle +i+ is moved and placed in front of the working robot 2), the robot (2) starts moving in response to a predetermined signal, and the coating gun 13) applies the coating gun 13) to the steel plate joint according to the stored contents. Move along the seam.

At this time, the body sealer is supplied to the gun (3) through the high-pressure hose (5) by the high-pressure pump (4), and is injected from the nozzle at the tip of the gun.

The working robot (2) used in the present invention generally has a
Field of assembly industry such as construction machinery, electrical machinery etc.
What is used is the rotation, tilting of the ten-do arm, extension and contraction,
Any device having 5 to 7 degrees of freedom such as wrist twisting and swinging may be used. Such a robot is used for automatic coating work after being taught in advance.

Since the sealer according to the present invention is applied by spraying,
In order to prevent the application area from becoming wider than necessary, it is necessary to spray and apply it in a relatively medium-sized line, for example, about 5 to 10 cm wide. For this purpose, a nozzle head provided at the tip of the coating gun of the present invention (2) having one or more injection holes as shown in FIG. 4 is used. When using a one-hole nozzle, The diameter of the injection hole is 30
A tapered shape having a diameter of 0 to 2000 μm is preferable. The multi-hole nozzle is preferably one with a lotus-root-shaped cross section having 3 to 7 injection holes, and its diameter is 100 to 10 mm.
It is desirable to set it to 00 μm. In addition, these nozzle heads have a tip shape with a diameter of the injection hole (DJ) as shown in Figure 3.
For example, it is advantageous in actual operation that the diameter of the injection port (l) is about 200 to 6007 Lm, and the length Ll is about 21njn. Preferably, the nozzle head is made of a material with low wear, such as stainless steel or tungsten steel.

Furthermore, during spray application of the body sealer according to the present invention, 1
2. In order to achieve the desired coating thickness and coating, it is preferable to maintain a constant distance between the steel plate joint of the car body to be coated and the head nozzle tip of the coating gun, usually several to several hundred millimeters, especially 5 to 200yr. By setting the distance between the surface to be coated and the gun within a certain range, when the first sealer is sprayed and reaches the steel plate joint, its spray energy can be used to maintain a constant coating thickness. can get. In addition, this ↓ Una application 111 and application thickness are affected by the distance between the L fertilizer application surface and the application gun, as well as the sealer discharge pressure, nozzle diameter, number of injection holes, etc., and these must be applied at the same time. By adjusting the coating thickness, a desired coating thickness can be achieved during coating.

In addition, in the sealing method according to the present invention, the moving speed of the nozzle head of the coating gun attached to the work robot is adjusted appropriately due to the speed of the automobile assembly production line7, and the pressure pump unit is adjusted according to the speed. Coating work is carried out.

The body sealer used in the present invention is usually a polyvinyl chloride-based plastisol sealer, which is generally made by mixing polyvinyl chloride powder for paste with dioctyl phthalate or dioctyl phthalate.
1. It is dispersed and kneaded in a plasticizer such as diisodecyl phthalate, and is filled with various usual additives such as calcium carbonate, clay, and silica, and metal soap to prevent dehydrochlorination. A viscosity-adjusting paste aid such as a stabilizer, an antioxidant, a pigment, an adhesion promoter, a viscosity stabilizer, and a thixotropic network is appropriately blended. This sealer has good discharging properties, and has a viscosity of 20.0 mm in order to obtain a spread coating surface [11.
000~70,0OOcps (20℃ with BH type viscometer)
It is preferable to have a viscosity of 13 [■ viscosity 1y
The ratio of the viscosity at 2 rotations divided by the viscosity at 200 rotations (,121, below, simply referred to as viscosity ratio) is 3.
The above are preferred. In addition, the discharge amount of sealer (7Ks7/cn for discharge air by Severs type extrusion viscometer,
Nozzle diameter 3mm, temperature 20℃) is 500P
/ min or more, usually 500-2000! It is desirable to have a speed of i2/min. When the above-mentioned sealer is heated to 120 to 170° C. in a paint baking oven in an automobile production line, its component polyvinyl chloride powder swells, fuses, and gels.

The sealing method of the present invention is applied to watertight and airtight sealing parts of steel plate joints of automobile bodies.
Inner panels such as the quarter channel of the front door and trunk, the joint between the roof panel and the sand panel, the joint between the half panel and the rear end, the tire house, the door hem, and the various plywood joints on the interior floor. , including the steel plate joints of the outer skin.

Furthermore, the sealing method of the present invention can be applied to various fields other than automobiles, for example, it can be used to spray watertight seals on electrical appliances such as refrigerators and washing machines.

The sealing method of the present invention can achieve the desired watertight and airtight sealing even in complex shapes and locations of steel plate joints in the automobile body, and it is also possible to adjust the coating thickness and finish the appearance during coating, unlike conventional methods. This eliminates the need for brush correction work, which not only streamlines the automobile production process, but also improves sole accuracy, making it extremely economically advantageous.

Next, the seal construction method of the present invention will be explained in more detail with reference to Examples, but the present invention is not limited thereto.

Example 1 A painting robot (manufactured by Mitsubishi Heavy Industries, Ltd.) was used as a working robot, and Penguin Seal +1516 (manufactured by Mitsubishi Heavy Industries, Ltd.) was used as a body sealer.
Manufactured by Sunstar Giken Co., Ltd., viscosity 5QOOOcps, using a Severs type extrusion viscometer discharge [1300P/min, viscosity ratio 5.0), King type mastic soil pump (manufactured by Nippon Gray Co., Ltd., pressure ratio 45:1) The liquid is fed under pressure to the head nozzle of the coating gun attached to the robot.

A single-hole stainless steel tapered nozzle with a diameter of 600 μm was used as the nozzle head, the distance between the steel plate joint and the nozzle was 5 mm, the coating gun was moved at a speed of 320 m/s, and the pressure of the pump air was 2 to 1/d. Body sealer is sprayed in a line under high pressure onto the steel plate joints of an actual vehicle body.

As a result, the sealer discharge rate was 400 P/min, and during application 8~
], Om, a coating film having a coating thickness of 2 to 3 Nn, a substantially uniform surface and excellent smoothness can be obtained. This product has a good surface finish without any brush correction work.

Example 2 Using the same work opening boll, body sealer, and pressure feed bobbin as in Example 1, a stainless steel nozzle (total cross-sectional diameter 6), the air pressure of the pump is 3KS'/cJ, and the distance between the X plate joint and the nozzle is 6Tan.
The coating was sprayed onto the joint in the tire house of an actual vehicle body at a nozzle head moving speed of 320 mm/sec.

As a result, the amount of sealer discharged was 900! i'/min, a coated film with good consistency of 3 to 4 coats thickness is obtained during coating at 15wn1.

[Brief explanation of drawings]

Figure 1 is a schematic diagram of a conventional manual flow gun, Figure 2
The figure is a schematic perspective view of a specific example of a coating device for a steel plate joint of an automobile body using a working robot used in the present invention.
The figure is a schematic cross-sectional view of the head nozzle attached to the tip of the coating gun used in the present invention, and FIGS. 4A, B, and C are cross-sectional views taken along line A-A in FIG. 3
The embodiments of holes and five holes are shown. The main symbols in the figure are as follows. J...Automatic stone car body, 2...Working robot, 3...
Application gun, 4...high pressure pump, 5...high pressure hose.

Claims (1)

[Claims] is) a method for sealing a car body by applying a body sealer to a joint between steel plates of a car body in an automobile production line,
Using a coating gun equipped with a nozzle head with one or more injection holes attached to a work robot, the sealer is sprayed in a line under high pressure while maintaining a distance between the coating gun and the steel plate joint to form a strip. An automobile body sealing method characterized by coating (2) The sealing method according to item (1) above, in which the distance between the coating gun and the steel plate joint is maintained at several to several hundred millimeters. (3) The sealing method according to item n or (2) above, wherein the band-like application of the sealer is performed by moving either or both of the object to be coated and the nozzle head. (4) Viscosity ratio of 3 or more and discharge as this body sealer! The sealing method of item il+ above using a polyvinyl chloride plastic sealer with a rate of 500 F/min or more. (5) The sealing method according to item 1), wherein the injection hole of the nozzle head provided in the coating gun has a diameter of 100 to 2000 μm. (6) The sealing method according to any one of items (1) to (5) above, wherein the coating gun is equipped with a multi-hole nozzle head having 3 to 7 injection holes.