A trailer control valve with external pressure regulating structure

Abstract

A trailer control valve with an external pressure regulating structure comprises an upper cover (1) and a valve body (15). An outer piston (2) and an inner piston (3) are arranged at the upper portion of an inner cavity of the valve body (15) respectively, a servo piston (6), a spring seat (7) and a guide sleeve (5) are arranged between a valve seat (10) and the inner piston (3), a plunger (8) is arranged in the middle of the guide sleeve (5), outer threads matched with inner threads on the inner wall of the spring seat (7) are arranged on the outer wall of the plunger (8) located on the position of the spring seat (7), a pressure regulating spring (9) is arranged between the spring seat (7) and the servo piston (6), a pressure regulating piston (4) penetrates through the hollow plunger (8) and can rotate to drive the plunger (8) to rotate, a step is arranged on the pressure regulating piston (4) below the plunger (8), an exhaust valve port (42) is formed in the step of the pressure regulating piston (4), and the tail of the pressure regulating piston (4) extends out of a valve body (18) and an exhaust seat (20). After a user selects a motor tractor and a semi-trailer according to tonnage matching, the user can freely adjust the braking proportion of the motor tractor and the semi-trailer according to loading states.

Description

technical field [0001] The invention relates to an automobile accessory, in particular to a control valve. Background technique [0002] The national standard stipulates that the trailer control valve used for the trailer braking system must be installed on the tractor, so the vehicle factory will configure the trailer braking control system according to the standard when producing the tractor, and arrange the trailer control valve on the tractor. in the air brake system on the Since there is no complete vehicle factory in China, tractors and semi-trailers are produced together. Either it is specialized in the production of tractors; or it is specialized in the production of semi-trailers. Users also need to buy a semi-trailer after purchasing a tractor. However, most users do not understand that the braking system of the tractor and the semi-trailer also needs to be matched in addition to the tonnage matching. The bad phenomenon shown by the mismatch of the braking syst...

AI Technical Summary

Problems solved by technology

like figure 1 As shown, the distance between the pressure adjusting screw 24 and the exhaust port is nearly 140mm, and the user cannot adjust it without a special tool.

And because the user does not know the product, it is even more unrealistic to adjust the product after disassembly. After all, it may not be able to recover after disassembly. In addition, if the user disassembles the product by himself, it is a violation of the three guarantees for the product.

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