Recently, in lieu of bond instead of spot welding or assembling the body part of the development of technology, the binder has a new application in the body assembly. In welding wire bonding glue to use, we need to have the car with the general performance of rubber, the most important thing is no adverse effect on the subsequent coating process, can withstand the wash coating pre-treatment process, do not pollute electrophoresis buffer , does not affect the quality of the coating.

Adhesive glue application

1 spot rubber

According to Fong fittings understand, J6 liberation of more than 400 pieces of white body stampings welded joints at the outer surface of sealing a direct bearing on the quality of the car body and its resistance to corrosion ability. In automotive manufacturing, sheet metal parts, if each gap junctions did not take effective measures to seal the deal, the car is in motion bound to leak, ventilate, abnormal noise and intake of dust and other undesirable phenomena, even cause weld steel corrosion, premature perforated steel sheet, accelerate scrapped vehicles.

The automotive industry is now a common approach is coated welding seam sealing glue, that is, before stamping welding, spot welding adhesive coated first in a single panel stamping station at the end, and then the two boards together and welding, coating After loading bake cure.

Spot welding of plastic used in automobile production requires a good construction techniques and thixotropic, to ensure sealing performance. After the coating process at the time of the follow-up treatment, will not be washed away, not contaminated liquid electrophoresis, spot not contain silicon rubber material, and that does not affect the strength of plastic welding spot welding, spot welding of plastic can decompose harmful gases or substances cause metal corrosion, the heating process is not flowing, the cured film should have sufficient flexibility and adhesion, chemical resistance, resistance to aging.

2 damping rubber

J6 automobile body in the manufacturing process, the outer cover panel body with the reinforcing plate or enhance binding between the beams usually used soldering method for assembling the reinforcing beam roof panel, door panel, the inner left side panel and the combination of the outer panel, have taken welding methods. Since the outer plate and the reinforcing plate or enhance certain gap between the beams may be generated due to vibration of the driving noise, and also the outside plate solder serious damage to the appearance of the flatness, in order to overcome the above disadvantages, J6 production BIW with adhesive tape vibration method to solve this problem.

Damping strips (or pieces of plastic) in the body J6 car doors, side panels and the inner contact surface of the top panel reinforcement beam and the top cover plate and the outer plate of the binding. Its process is: the body design, the inner plate reinforcing plate and set aside to strengthen the beam gluing groove before welding the damping strip (or plastic blocks) combined with the outer plate in the groove, heated drying Dry cured. Strips (or rubber block) after curing has a high adhesive strength, thermal expansion of the reinforcing beam after the outer plate closely integrated. Instead of the solder joint, which can improve the aesthetic appearance of the body, with reduced vibration and noise (see Figure 2).

Sealants and similar joints, damping glue do not have to set up a separate heat curing reconcile, usually in the drying oven puffed electrophoretic coating, curing, so its use requires the same process conditions and welding sealant.

3 folding plastic

Welding current J6 door outer panel assembly generally used Flap adhesive coating, roll nip after the inner and outer plates connected manner (see Figure 3). Overcome the past, both inside and outside the car door leading to the surface plate welding weld quality defects pits.

In addition to play a role in the bonding glue flap inside and outside the board, but also prevent moisture, water, sand intrusion. Prevent internal and external plate lap and corrosion due to water immersion, increase reliability and outside board connections.

Bonding instead of welding to manufacture cars flap portion has a very wide range of applications, is the development direction of the automobile manufacturing process, in addition to the doors, hood, trunk lid, can also be used in other parts of the side panels and the like.

    Glue construction method

BIW now J6 spot sealants and plastic folding doors are carried out by the method of coating extrusion coating airless.

Airless extrusion coating using compressed air or electricity as power driven high pressure pump, the suction drum by a sealant pump working chamber and to the high pressure (5 ~ 30MPa), then through the high pressure hose, glue guns, glue applied by a human operator in the gap at the workpiece surface.

Airless extrusion coating can be used for high viscosity glue, glue pump, glue gun glue output pressure is adjustable, the glue is easy to control, for different parts of the weld, using different forms of muzzle (such as crude sealed body parts using large-caliber muzzle fine sealing parts using a small-caliber, muzzle profiling), operating flexibility and convenience, the plastic volume, continuous operation is good, high working efficiency, suitable for assembly line. Meanwhile, the way painting equipment requirements, design and construction should consider the following aspects.

1) transmission line pressure hose good performance, can withstand 1.5 times the maximum working pressure of the pressure, no leakage, no leakage.
2) sealing pipe joints, the transition smooth, step-free existence in the pipe wall.
3) firmly support the pipeline, anti-pulse pressure performance.
4) stainless steel piping material selection, dry pipe thickness 6 ~ 8mm, branch pipe thickness 3 ~ 4mm, pipe wall requires clean and smooth.
5) trunk, branch pipes have insulation.

Coating equipment

According to informed Lixin fittings, automotive industry with adhesive systems commonly used in spray adhesive or sealant. Automated system will draw to glue plastic bucket from its quantitative and applied to the workpiece, the liberation of the company J6 BIW welding workshop equipment used for the SCA adhesive coating system. SCA coating system is a modular system, mainly by plastic barrel pump (including the controller PCU 3000), quantitative machine, glue guns, fittings (rubber tubes, hoses, cables) and system cabinets (including the controller APC, The cold glue adhesive systems manually without control cabinet) and other components.

According to their specific role can be divided into glue supply system, station exit gun glue supply system, mainly by the double barrel for plastic device is switched focus, dual-filter set, high pressure hose for road, pneumatic booster pump plunger and work Bit outlet assembly and control cabinet composition.

Gun assembly station exit from the union under high pressure regulator, pressure filter, high pressure hose, gun, high pressure or high pressure spray gun glue gun components. Centralized site for plastic double pump through the high-pressure pipeline to transport the plastic coating stations, each station exit independent regulator, independent of the filter. Take the form of a double pump with a prepared, when the need to replace the plastic buckets, level switch is touched, gas control valve will feed pump gas source off, and open the standby pump gas source switch, the standby pump to work, so ensure that equipment can work continuously. Different materials require different viscosity construction pressure, the pressure of the main pump is adjustable to a maximum 3.45 × 107Pa, each independent regulator station exit. Characterized by high pressure pneumatic piston pump to run smoothly, the output pressure and flow stability of the coating, the plunger upward and downward movement of the coating can be output, according to the reciprocating motion of the pump outlet pressure relief circumstances, the frequency of the reciprocating motion with the discharge outlet pressure increases, so small pump worn wearing parts, long life, pump pressure ratio is 65:1. With the increase of traffic paint, spray pressure has dropped, so you can control characteristic curve, according to the demand for paint spray flow to find the required pressure.

Maintenance of spraying equipment should primarily do the following:

1) Pre-class production equipment systems should be checked for glue and make a record. When the device is working, the control cabinet door must be closed.
2) Regular maintenance coating equipment systems, cleaning filters, replacement of wearing parts.
3) good lubrication and maintenance of equipment parts and units, in lubricating parts (such as air motors and pumps at the bottom of the bowl throat, etc.) regularly adding a lubricant and sealing liquid.
4) ensure that the surrounding environment clean coating equipment systems.
Extrusion coating the seam sealant, the need to select a different style squeeze glue gun according to different parts of the extrusion coating, but also with a variety of different types of special muzzle (such as flat nozzle, the nozzle head and the tape guide length muzzle, etc.) .

Occur when gluing problems and solutions

In J6 BIW production gluing process will often encounter some problems, common problems and their solutions are as follows:

1 no glue glue gun

Glue for some time after exposure to air will be solidified, the solidified glue glue gun with a muzzle or hose clog, resulting in no glue gun glue. Solutions are as follows:

1) occurs when the glue gun nozzle blockage, cork pin dredge; obstruction occurs when the spray gun nozzle, using the method of reverse self-cleaning dredge, coming in the opposite direction using the nozzle direction of rotation, hook the trigger to blow out the blockage , then converted back to working condition, if still the glue, glue gun replacement.

2) Check the wear condition of the needle gun, the gun body and seals, and timely replacement of the corresponding parts.

3) Do not let the gun was painted collision or falling to the ground during operation.

4) Do not disassemble the gun.

5) After work, to clean up the glue gun.

2 surface after drying sealant depression

If necessary, some welds require coating layer is very thick, layer shrinkage phenomenon often occurs after pre-baking oven, the main reason is the low viscosity glue. Because more volatile solvent glue, white body deformation leads to a larger weld. Solutions are as follows:

1) Contact the manufacturer to change the glue sealant formulation, an appropriate increase in the viscosity of the sealant.
2) Contact the relevant personnel to repair welding deformation of the car. The weld process control within range.
3) In the focus waterproof lap steel, pre-coated plastic body shop expansion vinyl.

3 vibration strips off

According to Fong fittings understand, usually in white body paint shop before entering, strip off, mainly due to the following:

1) inner plate stiffeners and reinforcing beam did not punch out glue grooves, resulting in strips attached to the board difficult.
2) the inner and outer plates gap is too large, the outer plate is not attached strips, loss in the production process.
3) strips viscosity enough, resulting in loss in the production process.

Prevention and solutions: an increase in the stamping groove; increased assembly precision, reasonable design structure inside and outer plates, so the gap and outer plates suitable; notification manufacturer changed the recipe, increase the viscosity strips.