Pressure-limiting and air-relieving auxiliary brake valve device with vent hole plug

Abstract

The invention relates to a pressure-limiting venting auxiliary brake valve device with an air vent screw plug. The pressure-limiting venting auxiliary brake valve device comprises a valve body, a disk, a support device, a pressure adjusting device, and a pressure relief opening device. A fixed through hole is reserved on the valve body. A drive shaft penetrates the fixed through hole to fix the disk in the inner cavity of the valve body. The pressure adjusting device comprises a shell, a piston tappet, an inner spring and a piston sleeve. The screw plug is in a cup shape. The inner spring is contacted with inner side of the cup bottom. One end of the screw plug near the cup bottom is provided with outer threads by tapping. The screw plug is connected with shell of the pressure adjusting device in a threaded manner. A notch is reserved at the cup opening of the screw plug. At least one air vent is reserved at the cup bottom of the screw plug. The pressure limiting venting auxiliary brake valve device is compact in structure, can effectively control motion travel of the piston tappet and improve exhaust back pressure of an engine at low speed, guarantees low resistance of reciprocating motion of the piston tappet, prevents failure of an inner spring due to high temperature, and enables service life of the auxiliary brake valve device to be prolonged.

Description

technical field [0001] The invention relates to an auxiliary braking device, in particular to a pressure-limiting and air-releasing auxiliary braking valve device of a vehicle with a vent plug. Background technique [0002] The pressure-limiting and air-leakage auxiliary brake valve device is an auxiliary braking device for vehicles, especially suitable for commercial vehicles. Vehicle brake failure to ensure driving safety. [0003] The pressure-limiting and deflated auxiliary brake valve device in the prior art relies on the cylinder or the vacuum booster cylinder to push and pull the drive shaft to deflect to make the butterfly plate deflect. The drive shaft is inserted into the butterfly plate and fixed with rivets, and the force of the drive shaft deflection acts on the rivet , The rivet is easily deformed and broken under a large compressive force, and the butterfly cannot realize its effective movement. [0004] Chinese Patent Nos. 200710137250.X and 200810126049.6 ...

AI Technical Summary

Problems solved by technology

[0003] The pressure-limiting and deflated auxiliary brake valve device in the prior art relies on the cylinder or the vacuum booster cylinder to push and pull the drive shaft to deflect to cause the butterfly plate to deflect. The drive shaft is inserted into the butterfly plate and fixed with rivets. , the rivet is easily deformed and broken under a large pressure, and the butterfly cannot realize its effective movement

[0004] Chinese Patent Nos. 200710137250.X and 200810126049.6 disclose a kind of exhaust brake, which includes a valve body, a disc, a support rod, a support sleeve, a pressure reducing valve, a spring and an adjusting screw. Release the excess pressure to ensure the stability of the working pressure, but when the pressure reducing valve is opened to adjust the pressure, it will cause hot gas to surround the spring, and the very high temperature will easily cause the spring to fail; moreover, the pressure reducing valve, the pressure plate and the adjusting screw have no guiding design, and the combination is not good. Stable, the offset of the pressure plate makes the adjustment screw unable to adjust the proper pressure; in addition, the pressure plate and the pressure reducing valve are easy to rotate, causing the spring torsion and causing the spring to break and fail

When the butterfly plate is closed and the engine exhaust gas is discharged into the intake chamber of the valve body, a part of the gas will inevitably enter the housing of the pressure regulating device, which hinders the reciprocating movement of the tappet and cannot effectively control the exhaust back pressure.

At the same time, due to the high temperature of the exhaust gas of the engine, the closed structure prevents the inner chamber of the pressure regulating device from dissipating heat, and the continuous high temperature will cause the pressure limiting spring to be deformed by heat, or even fail, and the braking effect of the auxiliary brake valve is seriously delayed, and the sensitivity is greatly reduced

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