Construction machinery parts SV98-T3003 24V for John Deere solenoid valve

Proportional pressure valve failure analysis and elimination

Because the proportional pressure valve is only on the basis of the ordinary pressure valve, the regulator handle is replaced by a proportional electromagnet. Therefore, the various faults generated by the ordinary pressure valve, which will also produce the fault causes and elimination methods of the ordinary pressure valve are also fully applicable to the corresponding proportional pressure valve (such as the corresponding proportional relief valve), which can be handled by reference. In addition:

① Proportional electromagnet no current through, so that the voltage regulation failure at this time can be analyzed according to the above "(1) proportional electromagnet fault" content. When the voltage regulation failure occurs, you can first check the current value with an electric meter to determine whether there is a problem with the control circuit of the electromagnet, or a problem with the proportional electromagnet, or a problem with the valve part, which can be symptomatic.

② Although the current flowing through the proportional electromagnet is rated, but the pressure does not go up at all, or the required pressure is not available, between the proportional pilot pressure regulator (relief valve) and the main relief valve, the pilot manual regulator of the ordinary pilot relief valve is still retained, which plays the role of a safety valve here. When the valve regulation pressure is too low, although the proportional electromagnet through the current is rated, but the pressure does not go up, if the valve set pressure is too low, the pilot flow from the valve flow back to the tank, so that the pressure does not come. In this case, the valve setting pressure should be increased by about 1MPa than the maximum working pressure of the valve.

(3) The current flowing through the proportional electromagnet is too large, but the pressure is still not up, or the required pressure can not be checked at this time the coil resistance of the proportional electromagnet, if far less than the specified value, then the internal circuit of the electromagnet coil is broken; If the electromagnet coil resistance is normal, then the connection to the proportional amplifier is short-circuited. At this time, the proportional electromagnet should be replaced, and the connection should be connected, or the rewound coil should be installed.