Abstract: A vehicle body composite coating, comprising, in succession, a polyurethane finishing coat, a polyurethane intermediate layer, a polyester putty and a micro-arc oxidation ceramic layer undercoat, wherein the micro-arc oxidation ceramic layer undercoat is on an aluminium substrate of the vehicle body. The design method of the vehicle body composite coating includes establishment of a physical model, selection of an optimal thickness ratio, preparation of the vehicle body composite coating and an erosion test. The vehicle body composite coating enhances the binding force between the whole coating system and the aluminium alloy substrate, reduces the possibility of shedding of the coating as a whole, and improves the anti-erosion performance of the vehicle body composite coating.

Abstract: A welding clamping device includes a base plate and two positioning slide blocks, each of the positioning slide blocks includes a slide base and a cam, wherein the slide base includes a support plate and two cam holders fixed at two opposite ends of the support plate; the cam is rotatably mounted between the two cam holders via a camshaft for press-fitting a workpiece to be welded; and the base plate is provided with a slide slot, and the two positioning slide blocks are relatively slidably mounted in the slide slot. The device can better position a workpiece to be welded, improving welding quality; and clamping and unloading are easy and take a short time, improving welding efficiency.

Abstract: A vehicle body composite coating, comprising, in succession, a polyurethane finishing coat, a polyurethane intermediate layer, a polyester putty and a micro-arc oxidation ceramic layer undercoat, wherein the micro-arc oxidation ceramic layer undercoat is on an aluminium substrate of the vehicle body. The design method of the vehicle body composite coating includes establishment of a physical model, selection of an optimal thickness ratio, preparation of the vehicle body composite coating and an erosion test. The vehicle body composite coating enhances the binding force between the whole coating system and the aluminium alloy substrate, reduces the possibility of shedding of the coating as a whole, and improves the anti-erosion performance of the vehicle body composite coating.

Abstract: A welding clamping device includes a base plate and two positioning slide blocks, each of the positioning slide blocks includes a slide base and a cam, wherein the slide base includes a support plate and two cam holders fixed at two opposite ends of the support plate; the cam is rotatably mounted between the two cam holders via a camshaft for press-fitting a workpiece to be welded; and the base plate is provided with a slide slot, and the two positioning slide blocks are relatively slidably mounted in the slide slot. The device can better position a workpiece to be welded, improving welding quality; and clamping and unloading are easy and take a short time, improving welding efficiency.