Analysis of the Causes of the Failure of the Main Control Valve of the Air Compressor of the Terex 3307A Dump Truck

2021-05-02

The working principle of the main control valve The working principle of the main control valve

After the compressed air coming out of the air compressor passes through the one-way, the other components of the main control valve are reassembled, and the valve 1 enters the stage air reservoir. When the pressure of the air reservoir increases to the specified air compressor value of 0.83, the right side of the main control valve The thrust is greater than the spring force on the left and the main control valve is in the right working position. The gas flowing out from the main control valve causes the pneumatic control check valve 2 to work, and the air intake and exhaust of the air compressor are connected to realize the empty load operation of the air compressor.

The compressed gas in the system cannot flow to the air compressor due to the action of the one-way valve 1, and the dehumidification valve can only work when the system pressure reaches a prescribed value.

The design of the air compressor to achieve the empty load operation after reaching the specified value not only ensures the stability of the system pressure, but also avoids the bursting of the pipeline when the system pressure greatly exceeds the specified value, and can prolong the service life of the air compressor.

Failure phenomenon of main control valve adjustment failure In the use of the vehicle, the system pressure often reaches the specified value, the air compressor also works straight. The pre-tightening force of the main control valve spring cannot achieve the empty load operation of the air compressor under the corresponding pressure. The compressed air outside the specified value in the brake system is completely discharged through the safety valve, and the two safety lines of the brake system become the case where only the safety valve is fully loaded. This situation is dangerous because the compressed air in the air reservoir will be quickly discharged into the atmosphere due to the failure of the safety valve, causing the vehicle brake system to malfunction.

Analysis of the reasons for the failure of the main control valve adjustment We have disassembled and checked the main control valve that was replaced during the inspection. It is found that the wear of the inner seal of the valve is not serious and can be used continuously. Check the valve body and find the special filter of the air inlet. Dirty, the top is covered with oil. The cleaning air inlet filter is installed on the air compressor to test, the function of the main control valve can be restored, and the maximum output pressure of the air compressor can be sensitively adjusted by adjusting the spring preload.

Originally, when the compressed air coming from the air reservoir enters the main control valve, the flow area is reduced due to the clogging of the filter screen, and a damping hole is formed. The control gas is decompressed, and the depressurized gas is insufficient to promote the main control. The piston in the valve moves in the direction of the compression spring, and the control gas cannot enter the micro-piston Cylinder at the top of the air compressor to push the piston downward, and open the one-way valve in the air compressor to make the air compressor enter. The exhaust ports are connected to achieve an empty load operation.

There is another situation in use.

From the control principle and actual structure of the main control valve, there are two joints on the main control valve, one connected to the air reservoir and the other connected to the moisture exhaust valve. During the overhaul, the dehumidification valve is often left unattended by the maintenance personnel for various reasons. At this time, since the joint and the micro-piston cylinder at the top of the top of the air compressor cannot work, even if the system reaches the rated pressure, the air compressor is still working continuously, and the main control valve cannot function as a control. The mouth is flat and the beautiful couple is eating dinner at home. The flat head is eager to drink the pot head, mouth wine and mouth dish, that is called beauty! It may be that the dishes here are delicious, and the two wines are in the belly, and I haven’t felt it! Anyway, nothing happened at night. Then drink again.

Drinking, the phone rang. Pingtouer picks up the phone and feeds! Who, Xiao Wang, what, what is missing! No. I have been drinking that line, OK! wait for me!

Beauty hurry to say that you can't drive!

Pingtou children dare to control me through the wine. Got it. I can't manage you! Beautiful side said to go outside the door.

Pingtou swayed and dressed, and tossed for a long time before going out. Sitting in the car, he did not know how to open the street. Just entering the street is encountering a red light, the police on duty carefully inspected the intersections. When I saw the flat-headed car, the policeman came over to the flathead. Pingtou’s heart is bad! Could he know that I am drinking, but I can't drink it!

After the police finished the ceremony, he said to Pingtou that you have a driver's license. You have a drink, how do you know, get off and look at your license plate.

Pingtou was puzzled by the underground car, and only a blank sheet of paper was attached to the license plate. It says that the driver drunk driving! Port Auto Clinic □ Jiangxi Hu Tielin Air Compressor Main Control Valve Failure Cause Analysis Terex 330 Dump Truck □ Beijing Zhang Zhigang Report

The Terex control valve contain Terex air control valve,Terex hydraulic control valve,Terex control valve repair kit,Terex main control valve,Terex pressure control valve,Terex steering control valve.The hot sale products:Terex body control valve15302652; Terex main control valve assy29536518;Terex cylinder control valve20044397;Terex pressure control valve03417079;Terex pressure control valve 09249220;Terex steering control valve09074897;Terex steering control valve 15252436/15011925;Terex main control valve15046883/15046884.
Terex Air Control Valve, Terex Hydraulic Control Valve, Terex Main Control Valve, Terex Pressure Control Valve
Terex Parts Co., Ltd. http://www.svdequips.com