Adjustable load pressure compensation balancing system, end cover and counterbalance valve

An end cover for an adjustable load pressure compensation counterbalance valve, comprising an end cover valve body, wherein:

• a first cavity, a second cavity and a third cavity are formed in the end cover valve body, and the first cavity and the second cavity are connected with the third cavity;
• an inlet of the first cavity is a control oil input port, and a filter screen and a first orifice are sequentially disposed inwards from the inlet of the first cavity;
• a backpressure check valve is disposed in the second cavity, and an input end of the backpressure check valve is located on a side close to the third cavity;
• an adjustable orifice is disposed in the third cavity,
• wherein the adjustable orifice comprises a plug, a spool on the adjustable orifice, a variable throttling groove, a spring seat, a spring, a spring shield and an adjusting screw;
• the plug, the spool on the adjustable orifice, the spring seat and the spring are sequentially arranged in a channel direction of the third cavity;
• the spring has an end connected with the spring seat and an another end connected with the adjusting screw, and the spring shield is disposed outside the spring;
• the variable throttling groove is formed in the spool on the adjustable orifice;
• the spool on the adjustable orifice has an end connected with a load port of a counterbalance valve, located outside the end cover valve body, and an another end connected with the spring seat, and the variable throttling groove is connected with a counterbalance valve control cavity of the counterbalance valve.

An adjustable load pressure compensation balancing system, comprising:

• an adjustable orifice control module, wherein the adjustable orifice control module is used for receiving control oil and an oil from an outside, and the volume of the control oil passes through the adjustable orifice control module is increased with the increase of a pressure applied to the oil;
• a counterbalance valve control module, wherein the counterbalance valve control module is used for receiving the control oil, and the oil passes through the counterbalance valve control module is decreased with the decrease of the control oil acting on the counterbalance valve control module;
• an overcompensation rate adjustment module, used for adjusting an overcompensation rate of the counterbalance valve control module by disposing a plurality of detachable orifices;
• wherein when the pressure applied to the counterbalance valve control module by the control oil is maximum, a pressure applied to the adjustable orifice control module by the control oil is minimum, and then the pressure applied to the counterbalance valve control module decreases, while the pressure applied to the adjustable orifice control module increases;
• wherein the plurality of detachable orifices comprise two orifices, which are a first orifice and a second orifice respectively,
• wherein the adjustable orifice control module comprises an adjustable orifice, and the adjustable orifice comprises an adjustable orifice oil passage and an adjustable orifice control cavity,
• two ends of the adjustable orifice oil passage are connected with a control oil input port and a drainage port respectively, and the drainage port is used for recycling the control oil and oil in a counterbalance valve spring cavity of the counterbalance valve control module,
• the adjustable orifice control cavity is used for receiving oil from the outside, a size of the adjustable orifice oil passage is adjusted according to the pressure of the oil, and the adjustable orifice oil passage becomes larger with the increase of the pressure,
• wherein the counterbalance valve control module comprises a counterbalance valve, and the counterbalance valve comprises a first counterbalance valve oil passage, a second counterbalance valve oil passage and a counterbalance valve control cavity,
• the counterbalance valve control cavity is used for receiving the control oil, a size of the first counterbalance valve oil passage is adjusted according to the pressure of the control oil, the first counterbalance valve oil passage becomes larger with the increase of the pressure, and when the control oil is not received, the first counterbalance valve oil passage is disconnected, and
• a check valve is disposed in the second counterbalance valve oil passage, and the second counterbalance valve oil passage is connected only when the pressure applied to the counterbalance valve control module increases, and
• wherein the counterbalance valve control module further comprises a fourth orifice, and the oil in the counterbalance valve spring cavity returns to the drainage port through the fourth orifice.