Electric control dual-chamber relay valve

Abstract

The invention discloses an electric control dual-chamber relay valve which comprises a valve body, a piston rod positioned in the valve body and a lifting valve controlled by up-and-down motion of the piston rod, wherein a total air inlet of the valve body and an outlet of a brake cylinder are respectively communicated with a total air cavity and a brake cylinder cavity which are arranged at the upper part of the lifting valve, a piston on the piston rod comprises an upper piston and a lower piston, an upper template is arranged between the upper piston and the valve body, a lower template isarranged between the lower piston and the valve body, a pressure feedback cavity formed above the upper template is communicated with the brake cylinder cavity through a throttling hole, a first control cavity formed between the upper template and the lower template is communicated with a common pre-control pressure air inlet of the valve body, and a second control cavity below the lower templateis communicated with an emergency pre-control pressure air inlet of the valve. The relay valve has the advantages of safe and reliable property, high sensitivity, relatively lower difficulty in manufacture process and relatively lower manufacture cost.

Description

Technical field [0001] The invention relates to the technical field of control valves, in particular to a relay valve that controls the charging and discharging of a train brake cylinder according to an air pressure command to realize the functions of braking, relief and pressure maintaining. Background technique [0002] The relay valve is an important pneumatic component in the electro-pneumatic brake control device of railway locomotives and rolling stock. During the braking process of the vehicle, the master controller or the train control vehicle-mounted device first sends out control commands such as train traction, idling, and braking, and passes The train connection or train network transmits the command signal. After receiving the command, the electronic control component in the electro-pneumatic brake control device of each vehicle calculates the braking force according to the vehicle weight and the principle of electric brake priority, and then calculates the required b...

AI Technical Summary

Problems solved by technology

[0008] First, the lower chamber of the piston is the cavity where the pre-control pressure Cv enters during normal braking, and also the cavity where the emergency pre-control pressure Cj enters during emergency braking. The same cavity has two functions, so under normal conditions Next, it is necessary to ensure that the common brake pre-control pressure Cv and the emergency brake pre-control pressure Cj will not fill the lower chamber of the piston at the same time. If the lower chamber of the piston is filled with the two control pressures at the same time, it will inevitably superimpose and output a larger brake cylinder Pressure C, from the perspective of brake safety, this is not allowed by vehicle brake control, and the above-mentioned relay valve cannot completely prevent this phenomenon from happening

[0009] Second, the relay valve is an important part of the electropneumatic brake control device. As an important part of the electropneumatic brake of the railway vehicle, it is required to have good pressure following sensitivity, and the diaphragm 1 of the above relay valve is affected by the piston 5 constraints, the flexibility of activities is poor, and the resistance encountered in the movement of the piston is relatively large, which affects the sensitivity of the piston to pressure changes in the chamber, resulting in poor overall performance.

[0010] Third, the valve body of the above-mentioned relay valve is generally made by casting process. The valve body has a closed casting cavity and is integrated with each valve port. The casting process is difficult and the manufacturing cost is relatively high.

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