- 1 The main spool orifice is blocked
- 2 The main spool is stuck in the open position
- 3 The main valve balance spring breaks or twists so that the main valve core cannot be reset
- 4 The pressure-regulating bomb is twisted or not installed
- 5 The cone valve (or steel ball) is not installed (or broken)
- 6 The pilot valve seat is broken
- 7 Long-distance control port through the fuel tank
Method of exclusion:
- 1 Clean the orifice, filter or change the oil
- 2 Overhaul, re-assemble (the fastening force of the bonnet screws should be even), filter or change the oil
- 3 Change the spring
- 4 Replace or reload the bomb praise
- 5 Reinstall or replace
- 6 Replace the valve seat
- 7 Check the operating status of the electromagnetic reversing valve or the on-off status of the long-distance control port, and eliminate the source of the fault
The hydraulic system of the four-column hydraulic press and the equipment method of the motor on the tank are vertical and horizontal:
The vertical equipment method is to put the hydraulic pump and related pipelines in the oil tank. This structure is compact, beautiful, and has good oil absorption conditions, which is convenient for collecting oil leakage, but it is not convenient to repair the equipment.
In the case of horizontal equipment, it is more convenient to repair hydraulic pumps and piping exposed equipment.
There are two main methods for connecting the machine to the pump: flange type and bracket type.
Flange type: The hydraulic pump equipment is on the flange, and the flange is connected to the motor with flange. The coaxiality of the motor and the pump is easy to ensure, and the assembly and disassembly are also convenient.
Bracket type: The structure is simple, and the bracket can be welded by steel plate or casting, which is simple to manufacture and low in cost.
Suitable for single pieces. However, it is difficult to ensure that the axes are coaxial when equipment motors and pumps are used. The coaxiality of the motor and the pump should be ≤0.05mm, and the equipment should be adjusted carefully. In order to prevent the hydraulic pump from adding a rated load and oscillating due to the equipment error of the coaxiality, a flexible coupling is often used. In order to enhance the rigidity of the connection between the motor and the pump, attention should be paid to prevent resonance. Therefore, the hydraulic pump and the motor should be installed on a panel with outstanding rigidity to form a whole, and then installed on the fuel tank.
If you choose the YB- x x B variable vane pump, you can install the hydraulic pump device on the bottom plate of the pump first, and then device it on the pump device panel together with the motor. This structure is compact and easy to repair.
The pump equipment panel should be different according to the pump model and equipment method, and you can design it yourself.
Please keep the source and address of this article for reprinting：Causes of no pressure in the overflow valve of a four-column hydraulic press and its troubleshooting
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