JPS6149150B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for assembling automobile panels,
To provide a method for assembling automobile panels that has good workability on an assembly line and can be reliably rust-proofed. In recent years, as it has become common to spray salt on roads to prevent them from freezing in cold regions, there has been a stronger demand for corrosion resistance in automobiles than ever before. However, it is difficult for electrodeposition paint to adhere to the folded edges of automobile body hoods, doors, etc. (herein referred to as panels) and the narrow areas where the inner and outer panels are close together. Rust due to the intrusion of water and moisture is becoming a major problem. As a countermeasure against this problem, the most effective method is to apply a rust-preventive material to the folded portion and its vicinity beforehand and then assemble the inner and outer panels together, and various developments are being made. The following conditions are required for this assembly method: (1) From the standpoint of occupational health and safety, the rust-preventing material must be solvent-free. (2) The method of applying the anti-corrosion material must be one that allows for a uniform coating thickness in a short period of time. (3) Since the application of anti-corrosive material must be carried out intermittently on the assembly line, and there may be work stoppages, the anti-corrosive material remaining in the applicator should be easily cleaned. (4) Anti-corrosion materials should be easy to handle on the assembly line. etc. can be mentioned. The present invention has been made in view of the above points,
A method for assembling automobile panels in which the anti-corrosion material is a two-component, solvent-free thermosetting material consisting of a base agent and a hardening agent, and these are mixed reliably in a short time without using a mixer immediately before spray application. It provides: Embodiments of the present invention will be described in detail below with reference to the drawings. This will be explained using door assembly as an example. Figure 1 is a plan view of the door assembly line, Figure 2 is an automatic sprayer that applies thermosetting rust-preventive material, Figure 3 is a circuit diagram of the automatic sprayer applying rust-preventive material, and Figure 4 is: FIG. 5 is an enlarged sectional view of the coating gun and a time chart of the coating circuit. First, a door assembly line will be explained based on FIG. The outer panel of the door is put into the assembly line automatically or by a worker in the outer panel loading process 1, and dedonor is applied to the necessary parts in the dedonor application process 2, and the rust preventive material is automatically applied in the rust preventive material application process 3. The spray device 4 sprays a two-component solvent-free thermosetting rust preventive material all around the folded portion. On the other hand, the inner panel to which the sashes have been temporarily attached is automatically or manually fed into the assembly line in an inner panel feeding step 5, and brackets used for door locks, door hinges, etc. are welded in welding steps 6 and 7. The outer panel and inner panel that have undergone the above steps are combined in a merging step 8, and then folded and joined together in a seam-folding step 9. After that, it is carried out by a conveyor or other conveyance device. Next, based on FIG. 2, the automatic spraying device 4 for the anti-rust material will be explained. Spray devices described below are provided on each of the three sides of the mounting frame 15. (The configuration of each spray device is the same.) That is, the driving cylinder 16 is attached to the mounting frame 15, and although the details of its structure are not shown, a chain 17 is connected to both ends of the piston. The chain has pulleys 22,2
3 and further connected to the slide body 18. The slide body 18 is slidably attached to a guide rod 19 attached to the mounting frame 15. Reference numeral 100 is a supply unit for a two-component solvent-free thermosetting rust-preventing material, which will be described later; 20 is a spray gun attached to the slide body 18; and 25a and 25b are hoses for feeding the two-component thermosetting rust-preventing material. be. The outer panel 72 of the door is conveyed by the shuttle bar 30. When the automatic spray device 4 is reached, the lift cylinder 31 is actuated to raise the underframe 32 to which the positioning member 33 is fixed, and the outer panel 72 is positioned, lifted, and stopped. In this state, the cylinder 16 operates at the same time that the spraying of the anti-rust material starts, and the slide body 18
That is, the spray gun 20 begins to move and sprays the rust-preventive material onto the folded portion of the outer panel. The spray gun 20 only moves in a plane, but in the case of a door or a hood, this movement alone is sufficient since the door or hood is not curved much. Specific examples of the two-component solvent-free thermosetting rust preventive material used here are shown in Attached Tables 1 and 2.

【table】

【table】

【table】

[Table] In other words, the main component (A) which can be sprayed has a liquid epoxy resin and a liquid polycarboxylic acid anhydride as essential components, and a liquid primary or secondary amino compound and a curing accelerator as essential components. A sprayable curing agent component (B) containing a non-reactive epoxy resin diluent with a molecular weight of 300 to 4000 and a conductive powder as other essential components of component (A) and/or component (B). In both cases of component (A) and component (B), the viscosity at 10 rotations measured at 50°C using a B-type viscometer is
It is a two-component, solvent-free, thermosetting rust-preventing material with a viscosity of more than 20 times the viscosity at 50 rotations. Next, we will discuss the application circuit for the two-component solvent-free thermosetting rust preventive material in the third section.
This will be explained in detail based on FIGS. 4 and 5. In other words,
As shown in FIG. 3, the suction side of the first pump 102 driven by the motor 101 is connected to the main agent tank 1.
03, and the discharge side is connected to the mixing section 205a of the spray gun 20 via the main agent side line 104. In this main agent side line 104, from the first pump 102 side, a first heat exchanger 106, a first electromagnetic valve 107, and a first metering chamber 1 of a metering gun 108 are connected.
08a and the first atomizing chamber 205b of the spray gun 20 are respectively arranged. Quantitative gun 1
08 consists of a first metering chamber 108a, a second metering chamber 108b, and a cylinder section 108c, and as will be described later, the mixing ratio of the main agent and curing agent is determined by changing the volume of each metering chamber 108a, 108b. . Air pressure is introduced into the cylinder portion 108c via an air source, a fourth solenoid valve 110, and lines 109a and 109b. Note that the cylinder portion of the metering gun may be divided into first and second metering chambers. On the other hand, the suction side of the second pump 112 driven by the motor 111 is connected to the curing agent tank 113, and the discharge side is connected to the mixing part 205a of the spray gun 20 through the curing agent side line 114, and the main agent line 104 is connected to the mixing part 205a of the spray gun 20. Connect them in the same position and facing each other. In this curing agent line 114, from the second pump 112 side, a second heat exchange section 115, a second electromagnetic valve 116, and a metering section chamber 108 of a metering gun 108 are installed.
b and the second atomizing chamber 205c of the spray gun 20 are arranged, respectively. In addition, line 1
04 and line 114 are connected to the first heat exchanger 10
6 and the second heat exchanger 115 up to the spray gun 20, the inside of the line is maintained at a predetermined temperature, for example, 30 to 50°C, by using heating tape 225 or other heating material or insulation material. Chamber 205 for reducing the viscosity of the main agent and curing agent and turning them into particles
After complete particle formation in 205c and 205c, the base resin and curing agent are allowed to collide with each other in the mixing section 205a of the spray gun 20 to improve mixing. As shown in FIGS. 3 and 4, the spray gun 20 includes a cylindrical mixing part 205a, a first particulate chamber 205b, a second particulate chamber 205c, and a cylinder part 205b. A plunger 218 that can reciprocate is fitted into the piston 218, and this plunger 218 extends to the cylinder portion 205d and is connected to a piston 219. The tip of the plunger 218 is spherical, and the mixing portion 205a that matches the tip is provided with a tapered portion 205g. Further, a nozzle tip 220 is provided at the tip of the mixing section 205a and fixed with a cap 221. The mixing section 205a is equipped with a thermoskit 2 with contacts.
A first particulate chamber 205b and a second particulate chamber 205 each equipped with 05e and 205f.
c is connected with its mounting position perpendicular to and facing the axis of the plunger 218.
Note that these particle forming chambers 205b and 205c
is provided as close as possible to the mixing section 205a.
In addition, if the distance from when the main agent and curing agent meet until they are discharged is short, it will be difficult to mix them sufficiently, and if the distance is too long, they will be mixed well, but some curing will begin. It is desirable to Thermostat with contact 205e, 205
f is set at a predetermined temperature to prevent an increase in viscosity due to a decrease in temperature and at the same time eliminate pattern differences between the two liquids. Thus, the first particulate chamber 205b communicates with the main agent side line 104, and the second particulate chamber 205b communicates with the main agent side line 104.
c communicates with the curing agent side line 114. The distance between the tapered part 205g near the tip of the mixing part 205a and the nozzle tip 220 is made as small as possible, and the cleaning line 214 is connected to the third solenoid valve 21.
7 and a check valve 221. The cleaning line 214 is a one-sided liquid, for example, a line 114 from the curing agent side pump 112 is branched to a first line.
The pressure of the pump 112 directs the curing agent. This spray gun 20 has lines 222a, 222b and a fifth solenoid valve 2 in its cylinder portion 205d.
Pneumatic pressure is conducted via 23. Further, the first granulation chamber 205b, the second granulation chamber 205c, and the mixing section 205a are maintained at a constant temperature using a heating material such as a heating tape 225 or a heat insulating material, and the thermostat 205e, 205f guarantees the set temperature range. Next, one cycle of application of the two-component antirust material will be explained with reference to FIG. 5, which is a time chart of each member. FIG. 3 shows a state in which the previous application has been completed and all valves and switches are OFF. The first, second, and fourth solenoid valves 107 and 11 are activated by the command to start work.
6,110 switches. In other words, the first solenoid valve 1
07 is on the 107b side, and the second magnetic valve 116 is on the 116 side.
a side, and the fourth solenoid valve 110 is switched to the 110a side. Pump 10 driven by motor 101
2 supplies the main agent in the main agent tank 103, and the curing agent in the curing agent tank 113 by a pump 112 driven by a motor 111 is supplied to the lines 104, 114 and the metering chambers 108a, 108b of the metering gun 108, respectively. . After the time required to reliably supply the required amount to each metering chamber 108a, 108b, the first and second solenoid valves 107,
116 returns to the state shown in FIG. 1, and after a predetermined period of time has elapsed, the fourth solenoid valve 110 returns to the state shown in FIG. Then, the first solenoid valve 107 and the spray gun 2
0 mixing section 205a and the second electromagnetic valve 116 and the mixing section 205a of the spray gun 20.
The curing agent between the two is simultaneously pressurized by the metering gun 108. After pressurization, the fifth electromagnetic valve 223 is switched to the 223b side after a period of time has elapsed until the pressure reaches a steady state. The piston 219 and plunger 218 of the spray gun 20 move to the solid line position in FIG.
Chambers 205b, 205 where both drugs are made into particles
After generating turbulence and forming particles in step c, the mixing section 205
After flowing into the tube a and mixing in a turbulent state, it is ejected from the nozzle tip 220. When the piston rod 108d of the metering gun 108 reaches its lowering limit, the limit switch 124 is turned on. Upon receiving this signal, the fifth solenoid valve 223 returns to the position shown in FIG. Piston 219 and plunger 2 of spray gun 20
18 cuts the lines 104 and 114, and the tip of the plunger 218 descends to the tapered portion 205g of the mixing portion 205a and stops. The mixed liquid remains between the nozzle tip 220 and the plunger 218, but upon confirmation after the spray gun 20 completes its movement, the third solenoid valve 217 is switched to the 217b side, and the curing agent passes through the line 214 to clean them. do. Further, a check valve 221 prevents the mixed liquid from flowing into the line 214. With this, one cycle is completed. Mixing section 205a
Although the curing agent will remain on the tip of the nozzle tip 220, the curing agent alone will not cause a curing reaction due to the characteristics of the two-component material, so there will be no problem in the next cycle. In addition, the production tact is fast, and during line operation, if the main agent and curing agent are not completely reacted, the third solenoid valve 217 is not energized and held on the 217a side, thereby reducing wastage of cleaning liquid. Is possible. The door assembled in this manner is attached to the vehicle body, and the rust-preventive material is hardened during baking after undercoating, providing the desired rust-preventing effect. Note that it is optional to join the outer panel and the inner panel by spot welding after folding. As described above, the present invention has the following effects. (1) Since the main ingredient and curing agent of the two-component solvent-free thermosetting rust preventive material are atomized immediately before mixing, mixing is performed reliably in the spray gun, resulting in improved rust preventive effect. (2) Since the two-component anti-corrosion material is mixed in a cylindrical mixing section that is part of the spray gun without using a mixer, the coating device is simple and the mixture can be mixed reliably. (3) Furthermore, since it is two-component, maintenance on the assembly line is easy.

[Brief explanation of the drawing]

Figure 1 is a plan view of the door assembly line, Figure 2 is an automatic sprayer that applies thermosetting anti-rust material, Figure 3 is a circuit diagram of the automatic sprayer applying rust-preventive material, and Figure 4 is the coating. FIG. 5 is an enlarged sectional view of the gun and a time chart of the coating circuit. 4...Automatic spray device, 15...Mounting frame, 2
0... Spray gun, 102, 112... Pump, 107, 110, 116, 217, 223...
... Solenoid valve, 205b, 205c... Chamber to be turned into particles.

Claims (1)

[Claims] 1. Applying a thermosetting anti-rust material to the joint between the outer panel and the inner panel, joining them by folding, etc., and then heating to harden the rust-preventing material and assemble automobile panels. This method involves atomizing the main ingredient and hardening agent of a two-component solvent-free thermosetting rust preventive material, mixing the two, and immediately spraying this mixture on the joining area before joining both panels. A method for assembling automobile panels, characterized in that the assembled body is assembled to a vehicle body and heated together with the vehicle body to harden the rust-preventive material and perform rust-preventive treatment.