A hydraulic pump with load pressure feedback split control function and working process

Abstract

The application discloses a hydraulic pump with load pressure feedback shunt control function and a working process, comprising an integrated main pump, wherein the integrated main pump comprises a pump main body, a shunt valve, an electromagnetic switch valve, a bypass damper and a feedback damper; the pump inlet is connected with an oil tank, one end of the pump outlet is connected with a speed regulating valve, and the other end is connected with the shunt valve; the spring side of the shunt valve is connected with the speed regulating valve and a feedback oil way. The shunt valve and the oil pump are integrated and designed as a whole, the oil pump flow is controlled to supply the system according to the demand through the comparison between the load feedback pressure and the pump port pressure, the problem that the shunt valve must be arranged in the system due to the surplus of the fixed displacement pump flow under the condition that the system demand flow is small is solved, meanwhile, the problems of large shunt noise and high shunt loss along the way of the shunt valve in the system are avoided; the hydraulic pump flow is shunted in the pump, the flow channel through which the shunted flow passes is short, the pressure loss is small, the oil pump outlet pressure can be effectively reduced, and the energy saving is good.

Description

Technical Field

[0001] This invention relates to a hydraulic pump and its working process, and more particularly to a hydraulic pump with load pressure feedback diversion control function and its working process. Background Technology

[0002] Small and medium-tonnage cranes typically use engine-driven fixed displacement gear pumps to supply hydraulic oil to their systems. The output flow rate is determined by the engine speed, and under idling conditions, the gear pump's output flow rate remains essentially constant. To regulate the speed of the actuators, excess oil output from the gear pump is typically diverted through a flow divider valve within a multi-way valve. In construction machinery, especially cranes, the flow divider valve is integrated into the multi-way valve and located behind the operator's cab. During minor movements or low-speed operation of the crane, a large amount of high-pressure oil is diverted through the multi-way valve, resulting in significant fluid diversion noise and pressure loss. Since the multi-way valve is generally installed at the rear of the operator's cab, when hydraulic oil flows through the flow divider valve during hydraulic system diversion, it generates considerable noise, significantly impacting the user experience.

[0003] Patent CN211598995U discloses a gear pump with constant flow diversion function. By integrating multiple functional hydraulic valves and setting thin-walled small holes in the oil passage of the diversion valve, the pressure difference before and after the diversion valve remains constant, thereby achieving constant output flow control. This enables the pump to simultaneously supply the required flow to the hydraulic power steering system and the hydraulic control system without affecting each other. However, this patent uses a fixed damping orifice at the pump outlet, resulting in a fixed pressure difference and a constant flow rate. This fails to meet the function of adjusting the output flow rate according to changes in system demand. Summary of the Invention

[0004] Purpose of the invention: The purpose of this invention is to provide a hydraulic pump and its working process with load pressure feedback diversion control function. The diversion valve, solenoid valve and other components are integrated with the oil pump in one design. By comparing the load feedback pressure with the pump port pressure, the oil pump flow rate is controlled to supply the system on demand.

[0005] Technical solution: The present invention includes an integrated main pump, which includes a pump body, a flow divider valve, an electromagnetic switch valve, a bypass damper, and a feedback damper; the pump body inlet is connected to an oil tank, one end of the pump outlet is connected to a speed control valve, and the other end is connected to the flow divider valve; the spring side of the flow divider valve is connected to the feedback oil circuit after the speed control valve, and the other side of the flow divider valve is connected to the pump body outlet.

[0006] The flow divider valve is connected to the speed control valve via a feedback damping mechanism.

[0007] One end of the feedback damper's outlet is connected to a diverter valve, and the other end is connected to a feedback oil circuit. The feedback oil circuit is equipped with a bypass damper and an electromagnetic switch valve. In emergency or standby conditions, the electromagnetic switch valve is de-energized and enters the open circuit. The load feedback pressure oil flows directly back to the oil tank through the feedback oil circuit, realizing low-pressure unloading of the oil pump.

[0008] The inlet side of the bypass damper is connected to the feedback damper, and the outlet side is connected to the solenoid switch valve. The outlet of the solenoid switch valve is connected to the oil tank. In emergency or standby conditions, the solenoid switch valve is de-energized and is in the open circuit. The load feedback pressure oil flows directly back to the oil tank through the feedback oil circuit, realizing low-pressure unloading of the oil pump.

[0009] When the speed control valve opening is zero, the load feedback pressure is zero, and the pressure oil output by the pump pushes open the diversion valve, diverting all of it to the oil tank.

[0010] After the electromagnetic switch valve is energized and closed, the speed control valve opens, and the load pressure is transmitted to the spring side of the diverter valve. The hydraulic oil output by the pump is first supplied to the speed control valve, and the excess flow is diverted by the diverter valve to achieve partial diversion.

[0011] The outlet of the diverter valve is connected to the oil tank so that excess oil can flow back to the oil tank.

[0012] The outlet of the speed control valve is connected to the oil tank via a motor.

[0013] The working process of a hydraulic pump with load pressure feedback flow diversion control function includes the following steps:

[0014] Standby unloading: When the whole system is in standby and not in operation, the speed control valve opening is zero and the load feedback pressure is zero. At this time, the pressure built up by the pump output flow pushes open the diversion valve, realizing the full diversion to the oil tank.

[0015] When the system starts working, the solenoid switch valve is energized and closes. As the speed control valve opens, the load pressure is transmitted to the spring side of the flow divider valve. The hydraulic oil output by the pump is first supplied to the system to meet the flow requirements of the speed control valve. Excess flow will cause the pump outlet pressure to increase until the flow divider valve is pushed open to achieve partial flow diversion.

[0016] When the pump output flow is less than or equal to the flow required by the speed control valve, the pump outlet pressure is less than the load pressure of the diverter valve plus the spring force, the diverter valve is closed and does not divert flow.

[0017] Unloading function: The feedback oil circuit is equipped with feedback damping, bypass damping and solenoid switch valve. In emergency or standby conditions, the solenoid switch valve is de-energized and is in the open circuit. The load feedback pressure oil flows directly back to the oil tank, realizing low-pressure unloading of the oil pump.

[0018] In the unloading function, the load feedback pressure oil flows directly back to the oil tank through feedback damping and feedback oil circuit.

[0019] Beneficial effects: The present invention has the following advantages:

[0020] (1) This invention integrates the diverter valve and the oil pump into one unit. By comparing the load feedback pressure and the pump outlet pressure, the oil pump flow is controlled to supply the system on demand. This solves the problem that a diverter valve must be installed in the system when the system demand flow is small due to the excess flow of the fixed pump. It also avoids the problems of high diversion noise and high diversion delay loss of the diverter valve in the system.

[0021] (2) Since the hydraulic pump is generally installed on the chassis of the engineering crane, the noise generated by the diversion valve integrated on the hydraulic pump will not have a significant noise impact on the operator on the crane due to the blocking effect of the chassis structural components.

[0022] (3) The hydraulic pump flow is split inside the pump. Compared with the split flow in the upper vehicle system, the flow path of the split flow is shorter and the pressure loss is smaller. This can effectively reduce the oil pump outlet pressure and has good energy saving performance. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of the present invention. Detailed Implementation

[0024] The invention will now be further described with reference to the accompanying drawings.

[0025] like Figure 1 As shown, this invention solves the noise problem of multi-way valve diversion by eliminating the diversion function of the multi-way valve and achieving diversion control through the oil pump itself, thus improving the user experience. It includes an integrated main pump 1, a speed control valve 2, and a motor 3. The inlet of the integrated main pump 1 is connected to the oil tank 4, and the outlet is connected to the speed control valve 2. One end of the outlet of the speed control valve 2 is connected to the integrated main pump 1, and the other end is connected to the motor 3. Both the integrated main pump 1 and the motor 3 are connected to the oil tank 4.

[0026] The integrated main pump 1 includes a pump body 1.1, a flow divider valve 1.2, a solenoid switch valve 1.3, a bypass damper 1.4, and a feedback damper 1.5. The inlet of the pump body 1.1 is connected to the oil tank 4, and one end of the outlet of the pump body 1.1 is connected to the speed control valve 2, while the other end is connected to the flow divider valve 1.2. The spring side of the flow divider valve 1.2 is connected to the speed control valve 2 via the feedback damper 1.5, and the outlet of the flow divider valve 1.2 is connected to the oil tank 4. One end of the outlet of the feedback damper 1.5 is connected to the flow divider valve 1.2, and the other end is connected to the feedback oil circuit. The feedback oil circuit is equipped with the bypass damper 1.4 and the solenoid switch valve 1.3. The inlet side of the bypass damper 1.4 is connected to the feedback damper 1.5, and the outlet side is connected to the solenoid switch valve 1.3. The outlet of the solenoid switch valve 1.3 is connected to the oil tank 4.

[0027] By integrating the diverter valve 1.2 with the pump body 1.1, the diverter valve 1.2 is controlled to open and divert the flow by comparing the outlet pressure of the pump body 1.1 with the load feedback pressure, ensuring that the hydraulic oil flowing into the system meets the flow requirements of the speed control valve 2.

[0028] This invention can provide the following operating states:

[0029] Working state 1: Standby unloading: When the whole system is in standby and not in operation, the speed control valve 2 is open to zero and the load feedback pressure is zero. At this time, the pressure built up by the flow output of the pump body 1.1 pushes open the spring of the diversion valve 1.2, realizing the full diversion to the oil tank 4.

[0030] Operating State 2: When the system starts working, the solenoid switch valve 1.3 is energized and closed. As the speed control valve 2 opens, the load pressure is transmitted to the spring side of the diversion valve 1.2. The hydraulic oil output from the pump body 1.1 is first supplied to the system to meet the flow requirements of the speed control valve 2. Excess flow will cause the outlet pressure of the pump body 1.1 to increase until the diversion valve 1.2 is pushed open to achieve partial diversion.

[0031] Operating state 3: When the flow rate output by the pump body 1.1 is less than or equal to the flow rate required by the speed control valve 2, the outlet pressure of the pump body 1.1 is less than the load pressure of the diverter valve 1.2 plus the spring force, and the diverter valve 1.2 is in the closed state and does not divert flow.

[0032] Unloading function: A feedback damper 1.5, a bypass damper 1.4, and a solenoid switch valve 1.3 are set in the feedback oil circuit. In emergency or standby conditions, the solenoid switch valve 1.3 is de-energized and in the open circuit. The load feedback pressure oil flows directly back to the oil tank 4 through the feedback oil circuit, realizing low-pressure unloading of the oil pump.

[0033] The working process of a hydraulic pump with load pressure feedback flow diversion control function includes the following steps:

[0034] When the entire system is in standby mode, the speed control valve opening is zero and the load feedback pressure is zero. At this time, the pressure built up by the pump output pushes open the diversion valve, realizing the complete diversion to the oil tank.

[0035] When the system starts working, the solenoid switch valve is energized and closes. As the speed control valve opens, the load pressure is transmitted to the spring side of the flow divider valve. The hydraulic oil output by the pump is first supplied to the system to meet the flow requirements of the speed control valve. Excess flow will cause the pump outlet pressure to increase until the flow divider valve is pushed open to achieve partial flow diversion.

[0036] When the pump output flow is less than or equal to the flow required by the speed control valve, the pump outlet pressure is less than the load pressure of the diverter valve plus the spring force, the diverter valve is closed and does not divert flow.

[0037] Feedback damping, bypass damping, and a solenoid switch valve are installed in the feedback oil circuit. In emergency or standby conditions, the solenoid switch valve is de-energized and in the open circuit. The load feedback pressure oil flows directly back to the oil tank through the feedback damping and the feedback oil circuit, realizing low-pressure unloading of the oil pump.

[0038] This invention integrates the flow divider valve and the oil pump into one unit. By comparing the load feedback pressure with the pump outlet pressure, the oil pump flow is controlled to supply the system on demand. This solves the problem of having to install a flow divider valve in the system when the system's required flow is low due to the excess flow of the fixed displacement pump. It also avoids the problems of high flow divider noise and high flow divider distance loss in the system. Since the hydraulic pump is generally installed on the chassis of the engineering crane, the flow divider noise generated by the flow divider valve integrated on the hydraulic pump will not have a significant noise impact on the operator on the crane due to the shielding effect of the chassis structural components. The hydraulic pump flow is divided inside the pump. Compared with the flow divider in the crane system, the flow path of the divided flow is shorter and the pressure loss is smaller, which can effectively reduce the oil pump outlet pressure and has good energy saving.

Claims

1. A hydraulic pump having a load pressure feedback split control function, characterized by, The system includes an integrated main pump, comprising a pump body, a flow divider valve, an electromagnetic switch valve, a bypass damper, and a feedback damper. The pump body's inlet is connected to an oil tank, and one end of its outlet is connected to a speed control valve, while the other end is connected to the flow divider valve. The spring side of the flow divider valve is connected to the feedback oil circuit following the speed control valve, and the other side of the flow divider valve is connected to the pump body outlet. A feedback damper is connected between the spring side of the flow divider valve and the speed control valve. One end of the feedback damper's outlet is connected to the flow divider valve, and the other end is connected to the feedback oil circuit. A bypass damper and an electromagnetic switch valve are provided on the feedback oil circuit. The inlet side of the bypass damper is connected to the feedback damper, and the outlet side is connected to the electromagnetic switch valve. The outlet of the electromagnetic switch valve is connected to the oil tank.

2. A hydraulic pump with load pressure feedback flow control function according to claim 1, characterized in that, When the speed control valve opening is zero, the load feedback pressure is zero, and the pressure oil output by the pump pushes open the diversion valve, diverting all of it to the oil tank.

3. A hydraulic pump with load pressure feedback flow control function according to claim 1, characterized in that, After the electromagnetic switch valve is energized and closed, the speed control valve opens, and the load pressure is transmitted to the spring side of the diverter valve. The hydraulic oil output by the pump is first supplied to the speed control valve, and the excess flow is diverted by the diverter valve.

4. A hydraulic pump with load pressure feedback flow control function according to claim 1, characterized in that, The outlet of the diverter valve is connected to the oil tank.

5. A hydraulic pump with load pressure feedback flow control function according to claim 1, characterized in that, The outlet of the speed control valve is connected to the oil tank.

6. The working process of a hydraulic pump based on the load pressure feedback diversion control function according to any one of claims 1 to 5, characterized in that, Includes the following steps: Standby unloading: When the whole system is in standby and not in operation, the speed control valve opening is zero and the load feedback pressure is zero. At this time, the pressure built up by the pump output flow pushes open the diversion valve, realizing the full diversion to the oil tank. When the system starts working, the solenoid switch valve is energized and closes. As the speed control valve opens, the load pressure is transmitted to the spring side of the flow divider valve. The hydraulic oil output by the pump is first supplied to the system to meet the flow requirements of the speed control valve. Excess flow will cause the pump outlet pressure to increase until the flow divider valve is pushed open to achieve partial flow diversion. When the pump output flow is less than or equal to the flow required by the speed control valve, the pump outlet pressure is less than the load pressure of the diverter valve plus the spring force, the diverter valve is closed and does not divert flow. Unloading function: The feedback oil circuit is equipped with feedback damping, bypass damping and solenoid switch valve. In emergency or standby conditions, the solenoid switch valve is de-energized and is in the open circuit. The load feedback pressure oil flows directly back to the oil tank, realizing low-pressure unloading of the oil pump.

7. The working process of a hydraulic pump with load pressure feedback flow diversion control function according to claim 6, characterized in that, In the unloading function, the load feedback pressure oil flows directly back to the oil tank through feedback damping and feedback oil circuit.

Images