WO2021174931A1

WO2021174931A1 - Device and system with control logic for automatically switching between high and low pressure, and control method therefor

Info

Publication number: WO2021174931A1
Application number: PCT/CN2020/133555
Authority: WO
Inventors: 贾建辉; 沈千里; 苏艳玲; 石峰
Original assignee: 徐州徐工施维英机械有限公司
Priority date: 2020-03-04
Filing date: 2020-12-03
Publication date: 2021-09-10
Also published as: CN111322281A

Abstract

Disclosed are a device and system with a control logic for automatically switching between high and low pressure, and a control method therefor. The device with a control logic for automatically switching between high and low pressure comprises a first control logic unit, a second control logic unit and a control oil port assembly. The first control logic unit is connected to the second control logic unit by means of the control oil port assembly. The system with a control logic for automatically switching between high and low pressure comprises a hydraulic system and the device with a control logic for automatically switching between high and low pressure, and oil ports of the hydraulic system are respectively connected to the first control logic unit and the second control logic unit. The control method for the system with a control logic for automatically switching between high and low pressure comprises: a low-pressure pumping control step; and a high-pressure pumping control step.

Description

High and low voltage automatic switching control logic device, system and control method thereof

Cross-references to related applications

The present disclosure is based on the Chinese patent application with the application number 202010141774.1, the filing date of March 4, 2020, and the invention title of "a high and low voltage automatic switching control logic device, system and control method", and claims its priority Right, the disclosure of the Chinese patent application is hereby incorporated into this disclosure as a whole.

Technical field

The present disclosure relates to a high and low voltage automatic switching control logic device, a system and a control method thereof, and belongs to the technical field of high and low voltage automatic control.

Background technique

With the development of society, high-rise buildings are becoming more and more common. The rise of high-rise buildings provides new development opportunities for our concrete pumping industry, and also brings new challenges. At present, the major domestic concrete pumping machinery manufacturers are fully developing high-pressure pumping equipment.

In the prior art, four three-position four-way electromagnetic reversing valves are used to realize the reversing logic of high and low pressure switching. There are many pipelines, which are not conducive to integration and occupy a large space.

Summary of the invention

The present disclosure provides a high and low voltage automatic switching control logic device, which includes a first control logic unit, a second control logic unit, and a control port assembly; the first control logic unit communicates with the second control port assembly through the control port assembly. The control logic unit is connected;

The control oil port assembly includes a first control oil port, a second control oil port, a third control oil port, and a fourth control oil port;

The first control logic unit includes a first pressure oil port, a first hydraulic control check valve, a second hydraulic control check valve, a third hydraulic control check valve, a fourth hydraulic control check valve and a first cartridge The valve control oil port, the first pressure oil port is respectively connected to the control oil port of the first cartridge valve, the control oil circuit of the first hydraulic control check valve, and the control of the second hydraulic control check valve An oil circuit, a control oil circuit of the third hydraulic control check valve, and a control oil circuit of the fourth hydraulic control check valve;

The second control logic unit includes a second pressure port, a fifth hydraulic control check valve, a sixth hydraulic control check valve, a seventh hydraulic control check valve, an eighth hydraulic control check valve, and a second cartridge The valve control oil port, the second pressure oil port is respectively connected to the second cartridge valve control oil port, the control oil circuit of the fifth hydraulic control check valve, and the control of the sixth hydraulic control check valve An oil circuit, a control oil circuit of the seventh hydraulic control check valve, and a control oil circuit of the eighth hydraulic control check valve;

The first control oil port is respectively connected to the oil outlet of the first hydraulic control check valve and the oil outlet of the fifth hydraulic control check valve, and the second control oil port is connected to the fourth The oil outlet of the hydraulic control check valve and the oil outlet of the eighth hydraulic control check valve, the third control oil port is respectively connected to the oil outlet of the second hydraulic control check valve and the first The oil outlet of the six hydraulic control check valve, the fourth control oil port is respectively connected to the oil outlet of the third hydraulic control check valve and the oil outlet of the seventh hydraulic control check valve.

The present disclosure also proposes a high and low pressure automatic switching control logic system, which includes a hydraulic system and the aforementioned high and low pressure automatic switching control logic device. The oil ports of the hydraulic system are respectively connected to the first control logic unit and the second control logic unit.

In some embodiments, the hydraulic system includes a first three-position four-way reversing valve, a second three-position four-way reversing valve, a first spool valve, a second spool valve, a first cartridge valve, and a second cartridge valve , The first oil cylinder and the second oil cylinder, in which the first three-position four-way reversing valve, the second three-position four-way reversing valve, the first spool valve and the second spool valve are all spool valves; the first cartridge valve is respectively Connect the rod cavity of the first oil cylinder, the rod cavity of the second oil cylinder and the first spool valve. The first spool valve is connected with the second three-position four-way reversing valve; the second cartridge valve is connected to the valve of the first oil cylinder The rod cavity, the rodless cavity of the second cylinder and the second slide valve, the second slide valve is connected with the first three-position four-way reversing valve; the first three-position four-way reversing valve, the second three-position four-way reversing valve The valve pumps high-pressure oil externally through the oil supply port.

In some embodiments, the spools of the first three-position four-way reversing valve, the second three-position four-way reversing valve, the first spool valve and the second spool valve are laid out flat, and the first hydraulically controlled one-way valve , The second hydraulic control check valve, the third hydraulic control check valve, the fourth hydraulic control check valve, the fifth hydraulic control check valve, the sixth hydraulic control check valve, the seventh hydraulic control check valve and the first Eight hydraulic control check valves constitute four groups of hydraulic control check valves distributed at both ends; or the first three-position four-way reversing valve, the second three-position four-way reversing valve, the first spool valve and the second spool valve The spool is arranged in two layers, the first hydraulic control check valve, the second hydraulic control check valve, the third hydraulic control check valve, the fourth hydraulic control check valve, the fifth hydraulic control check valve, and the sixth hydraulic control check valve. The hydraulic control check valve, the seventh hydraulic control check valve and the eighth hydraulic control check valve constitute four groups of hydraulic control check valves arranged at one end.

In some embodiments, the first three-position four-way reversing valve, the second three-position four-way reversing valve, the first spool valve and the second spool valve are all spool valves.

In some embodiments, the first three-position four-way reversing valve is respectively connected to the oil inlet of the fifth hydraulic control check valve and the oil inlet of the eighth hydraulic control one-way valve; the second three-position four-way reversing valve Respectively connect the oil inlet of the first hydraulic control check valve and the oil inlet of the fourth hydraulic control check valve; the first slide valve is connected to the oil inlet of the second hydraulic control check valve and the third hydraulic control check valve respectively The oil inlet of valve v; the second slide valve is respectively connected to the oil inlet of the sixth hydraulic control check valve and the oil inlet of the seventh hydraulic control check valve.

In some embodiments, the first cartridge valve is connected to the first pressure oil port through the first cartridge valve control port; the second cartridge valve is connected to the second pressure oil port through the second cartridge valve control port.

In some embodiments, a circulating oil path for low-pressure pumping includes: pumping high-pressure oil input into the oil supply port sequentially enters the rod cavity of the first cylinder through the second three-position four-way reversing valve and the first slide valve, The pressure oil in the rodless cavity of the first oil cylinder enters the rodless cavity of the second oil cylinder through the second cartridge valve, and the pressure oil in the rodless cavity of the second oil cylinder passes through the first slide valve and the second three-position four-way exchange Output from the valve to the oil discharge port; the pumped high-pressure oil at the oil supply port sequentially passes through the second three-position four-way reversing valve and the first slide valve into the rod cavity of the second cylinder, and into the rodless cavity of the second cylinder The pressure oil enters the rodless cavity of the first cylinder through the second cartridge valve, and the pressure oil in the rod cavity of the first cylinder passes through the first slide valve and the second three-position four-way reversing valve 2 to the oil discharge port .

In some embodiments, a circulating oil circuit for low-pressure pumping further includes: pressure oil passing through the first pressure oil port and the first control oil port, the first hydraulic control check valve, the second hydraulic control check valve, and the first hydraulic control check valve. The three hydraulic control check valve and the fourth hydraulic control check valve are in the reverse connection state, the fifth hydraulic control check valve, the sixth hydraulic control check valve, the seventh hydraulic control check valve and the eighth hydraulic control check valve The one-way valves are in the reverse closed state, and the third control port and the fourth control port alternately show pressure oil; or the first pressure port and the second control port have pressure oil passing through, the first hydraulic control check valve , The second hydraulic control check valve, the third hydraulic control check valve and the fourth hydraulic control check valve are all in the reverse connection state, the fifth hydraulic control check valve, the sixth hydraulic control check valve, the seventh The hydraulic control check valve and the eighth hydraulic control check valve are both in a reverse closed state, and pressure oil alternately appears at the third control oil port and the fourth control oil port.

In some embodiments, a circulating oil circuit for high-pressure pumping includes: pumping high-pressure oil input into the oil supply port sequentially enters the rodless cavity of the first cylinder through the first three-position four-way reversing valve and the second slide valve, The pressure oil in the rod cavity of the first oil cylinder enters the rod cavity of the second oil cylinder through the first cartridge valve, and the pressure oil in the rodless cavity of the second oil cylinder passes through the second slide valve and the first three-position four-way exchange Output from the valve to the oil discharge port; the pumped high-pressure oil at the oil supply port sequentially passes through the first three-position four-way reversing valve and the second slide valve into the rodless cavity of the second cylinder, and into the rod cavity of the second cylinder The pressure oil enters the rod cavity of the first oil cylinder through the first cartridge valve, and the pressure oil in the rodless cavity of the first oil cylinder passes through the second slide valve and the first three-position four-way reversing valve to the oil discharge port for output.

In some embodiments, a circulating oil circuit for high-pressure pumping further includes: pressure oil passing through the second pressure oil port and the first control oil port, the first hydraulic control check valve, the second hydraulic control check valve, and the first hydraulic control check valve. The three hydraulic control check valve and the fourth hydraulic control check valve are in the reverse closed state, the fifth hydraulic control check valve, the sixth hydraulic control check valve, the seventh hydraulic control check valve and the eighth hydraulic control check valve The direction valves are in the reverse connection state, and the third control port and the fourth control port alternately show pressure oil; or the second pressure port and the second control port have pressure oil passing through, the first hydraulic control check valve , The second hydraulic control check valve, the third hydraulic control check valve and the fourth hydraulic control check valve are all in the reverse closed state, the fifth hydraulic control check valve, the sixth hydraulic control check valve, the seventh hydraulic control check valve The control check valve and the eighth hydraulic control check valve are both in the reverse connection state, and the third control oil port and the fourth control oil port alternately present pressure oil.

The present disclosure also proposes a control method of a high and low pressure automatic switching control logic system, which includes: a low pressure pumping control step; a high pressure pumping control step.

In some embodiments, the low-pressure pumping control step includes: when only the first pressure oil port, the first control oil port, and the third control oil port have pressure oil passing through, the first hydraulic control check valve, the second hydraulic The control check valve, the third hydraulic control check valve and the fourth hydraulic control check valve are all in the reverse connection state, the fifth hydraulic control check valve, the sixth hydraulic control check valve, and the seventh hydraulic control check valve The valve and the eighth hydraulic control check valve are in the reverse closed state, the control oil at the first control port flows through the first hydraulic control single valve to the second three-position four-way reversing valve, and the second three-position four-way reversing valve When the valve is in the left position, the pressure oil at the third control port flows to the first spool valve through the second hydraulic control check valve. The first spool valve is in the left position. The three-position four-way reversing valve and the first slide valve flow to the rod cavity of the first cylinder and the first cartridge valve. At this time, the control port of the first cartridge valve is pressurized oil, and the first cartridge valve is closed. The high pressure oil pushes the piston of the first oil cylinder, the pressure oil in the rodless cavity of the first oil cylinder acts on the second cartridge valve and the second slide valve. The second cartridge valve controls the oil port without pressure oil, and the second cartridge valve opens , The pressure oil in the rodless cavity of the first oil cylinder enters the rodless cavity of the second oil cylinder through the second cartridge valve to push the piston to move, and the pressure oil in the rod cavity of the second oil cylinder acts on the first cartridge valve and the first At the spool valve, the first cartridge valve is in a closed state, and the pressure oil in the rod cavity of the second cylinder passes through the first spool valve to the second three-position four-way reversing valve, and to the second three-position four-way reversing valve. Oil discharge port output; when the first pressure port, the first control port and the fourth control port are pressurized oil, the pressure oil at the fourth control port flows to the first slide through the third hydraulic control check valve Valve, the first spool valve is connected to the right position, the pumped high-pressure oil from the oil supply port passes through the second three-position four-way reversing valve, the first spool valve enters the rod cavity of the second cylinder, and the high-pressure oil pushes the second cylinder When the piston moves, the second cartridge valve controls the oil port without pressure oil, the second cartridge valve opens, and the pressure oil in the rodless cavity of the second cylinder acts on the second cartridge valve and enters the first cartridge through the second cartridge valve. The rodless cavity of the oil cylinder pushes the piston of the first oil cylinder to move, and the pressure oil in the rod cavity of the first oil cylinder passes through the first slide valve and the second three-position four-way reversing valve to the oil discharge port; when the third control oil When pressure oil alternately appears at the port and the fourth control oil port, the continuous movement of the first oil cylinder and the second oil cylinder is realized, thereby realizing low-pressure pumping.

In some embodiments, the high-pressure pumping control step includes: when there is only the second pressure port, the first control port and the third control port have pressure oil passing through, the fifth hydraulic control check valve, the sixth hydraulic The control check valve, the seventh hydraulic control check valve and the eighth hydraulic control check valve are in the reverse connection state, the first hydraulic control check valve, the second hydraulic control check valve, and the third hydraulic control check valve And the fourth hydraulic control check valve are in the reverse closed state, the pressure oil at the first control port flows to the first three-position four-way reversing valve through the fifth hydraulic control check valve, and the pressure oil at the third control port Enter the second spool valve through the sixth hydraulic control check valve, the second spool valve is connected to the left position, and the pumped high-pressure oil input to the oil supply port passes through the first three-position four-way reversing valve, and the second spool valve flows to the second spool valve. The rodless cavity of a cylinder and the second cartridge valve. At this time, the control port of the second cartridge valve is pressurized oil, the second cartridge valve is closed, and the high pressure oil pushes the piston of the first cylinder to move. The pressure oil in the rod cavity flows to the first cartridge valve and the first slide valve, and the second three-position four-way reversing valve, because the first hydraulic control check valve and the fourth hydraulic control check valve have no pressure oil, The second three-position four-way reversing valve is in the closed state, the first cartridge valve controls the oil port without pressure oil, the first cartridge valve is in the open state, and the pressure oil in the rod cavity of the first cylinder flows to the second The rod cavity of the oil cylinder pushes the piston of the second oil cylinder, and the pressure oil in the rodless cavity of the second oil cylinder flows to the second cartridge valve and the second slide valve, because the second cartridge valve control oil port is pressurized oil. The second cartridge valve is closed, and the pressure oil flows to the oil discharge port through the second slide valve and the first three-position four-way reversing valve; when the fourth control port is pressure oil, it passes through the seventh hydraulic control one-way The valve outputs pressure oil to the second spool valve, the second spool valve is connected to the right position, the high-pressure oil pumped into the oil supply port passes through the first three-position four-way reversing valve, and the second spool valve enters the rodless of the second cylinder Cavity, pushing the piston of the second oil cylinder to move, the pressure oil in the rod cavity of the second oil cylinder enters the rod cavity of the first oil cylinder through the first cartridge valve 5, pushing the piston of the first oil cylinder to move, and the rodless cavity of the first oil cylinder The pressure oil in the medium passes through the second slide valve and the first three-position four-way reversing valve to the oil discharge port; when pressure oil alternates between the third control port and the fourth control port, the first oil cylinder and the second oil cylinder are realized. The continuous movement of the oil cylinder realizes high-pressure pumping.

Description of the drawings

FIG. 1 is a schematic diagram of the structural connection principle of the high and low voltage automatic switching control logic device of the embodiment of the present disclosure.

Fig. 2 is a schematic diagram of the oil circuit connection principle of the hydraulic system of the embodiment of the present disclosure.

Detailed ways

The present disclosure will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to illustrate the technical solutions of the present disclosure more clearly, and cannot be used to limit the protection scope of the present disclosure.

Explanation of related terms:

Concrete pump: An energy conversion device that converts hydraulic energy into pressure energy of flowing concrete.

Main cylinder: An energy conversion device that converts hydraulic energy into mechanical energy. The main cylinder is connected to a concrete piston to convert hydraulic energy into concrete kinetic energy (potential energy).

Low-pressure pumping: The working hydraulic oil enters the state where the main oil cylinder has a rod cavity to push the main oil cylinder to work.

High-pressure pumping: The working hydraulic oil enters the rodless cavity of the main oil cylinder to push the main oil cylinder to work.

Hydraulic control check valve: a control valve that can be reversed through the hydraulic control.

As shown in Figure 1, the present disclosure provides a high and low voltage automatic switching control logic device, which includes a first control logic unit, a second control logic unit, and a control oil port assembly. The first control logic unit is connected with the second control logic unit through the control oil port assembly.

The control oil port assembly includes a first control oil port kz1, a second control oil port kz2, a third control oil port kz3, and a fourth control oil port kz4.

The first control logic unit includes a first pressure port Pd, a first hydraulic control check valve v1, a second hydraulic control check valve v2, a third hydraulic control check valve v3, a fourth hydraulic control check valve v4, and a second hydraulic control check valve v4. A cartridge valve controls port P5. The first pressure port Pd is respectively connected to the first cartridge valve control port P5, the control oil circuit of the first hydraulic control check valve v1, the control oil circuit of the second hydraulic control check valve v2, and the third hydraulic control check valve The control oil circuit of valve v3 and the control oil circuit of the fourth hydraulic control check valve v4.

The second control logic unit includes the second pressure port Pg, the fifth hydraulic control check valve v5, the sixth hydraulic control check valve v6, the seventh hydraulic control check valve v7, the eighth hydraulic control check valve v8 and the second hydraulic control check valve v5. Two cartridge valves control port P6. The second pressure port Pg is respectively connected to the second cartridge valve control port P6, the control circuit of the fifth hydraulic control check valve v5, the control circuit of the sixth hydraulic control check valve v6, and the seventh hydraulic control check valve. The control oil circuit of valve v7 and the control oil circuit of the eighth hydraulic control check valve v8.

The first control oil port kz1 is respectively connected to the oil outlet of the first hydraulic control check valve v1 and the oil outlet of the fifth hydraulic control check valve v5; the second control oil port kz2 is respectively connected to the fourth hydraulic control check valve v4 The oil outlet of and the oil outlet of the eighth hydraulic control check valve v8; the third control oil port kz3 is connected to the oil outlet of the second hydraulic control check valve v2 and the oil outlet of the sixth hydraulic control check valve v6. Port; the fourth control oil port kz4 is respectively connected to the oil outlet of the third hydraulic control check valve v3 and the oil outlet of the seventh hydraulic control check valve v7.

The present disclosure also proposes a high and low pressure automatic switching control logic system, which includes a hydraulic system and a high and low pressure automatic switching control logic device. The oil ports of the hydraulic system are respectively connected to the first control logic unit and the second control logic unit.

As shown in Figure 2, in some embodiments, the hydraulic system includes a first three-position four-way reversing valve 1, a second three-position four-way reversing valve 2, a first spool valve 3, a second spool valve 4, and a A cartridge valve 5, a second cartridge valve 6, a first cylinder 7 and a second cylinder 8. The first cartridge valve 5 is respectively connected to the rod cavity of the first oil cylinder 7, the rod cavity of the second oil cylinder 8 and the first spool valve 3. The first spool valve 3 is connected to the second three-position four-way reversing valve 2. The second cartridge valve 6 is respectively connected to the rodless cavity of the first oil cylinder 7, the rodless cavity of the second oil cylinder 8 and the second spool valve 4. The second spool valve 4 is connected to the first three-position four-way reversing valve 1. The first three-position four-way reversing valve 1 and the second three-position four-way reversing valve 2 are externally pumped with high pressure oil through the oil supply port P (also called P port).

In some embodiments, the first three-position four-way reversing valve 1 is respectively connected to the oil inlet P11 of the fifth hydraulic control check valve v5 and the oil inlet P12 of the eighth hydraulic control check valve v8; the second three positions The four-way reversing valve 2 is connected to the oil inlet P21 of the first hydraulic control check valve v1 and the oil inlet P22 of the fourth hydraulic control check valve v4 respectively; the first slide valve 3 is connected to the second hydraulic control check valve respectively The oil inlet P31 of v2 and the oil inlet P32 of the third hydraulic control check valve v3; the second slide valve 4 is respectively connected to the oil inlet P41 of the sixth hydraulic control check valve v6 and the seventh hydraulic control check valve v7的油口P42.

In some embodiments, the first cartridge valve 5 is connected to the first pressure port Pd through the first cartridge valve control port P5; the second cartridge valve 6 is connected to the second pressure port through the second cartridge valve control port P6 Port Pg.

In some embodiments, a circulating oil circuit for low-pressure pumping includes:

The pumped high-pressure oil input to the oil supply port P enters the rod cavity of the first cylinder 7 through the second three-position four-way reversing valve 2 and the first slide valve 3 in turn, and the pressure oil in the rodless cavity of the first cylinder 7 Enter the rodless cavity of the second cylinder 8 through the second cartridge valve 6, and the pressure oil in the rod cavity of the second cylinder 8 passes through the first slide valve 3 and the second three-position four-way reversing valve 2 to the oil discharge port T (also known as T port) output; the pumped high-pressure oil at the oil supply port P sequentially passes through the second three-position four-way reversing valve 2 and the first slide valve 3 into the rod cavity of the second cylinder 8, the second cylinder The pressure oil in the rodless cavity of 8 enters the rodless cavity of the first cylinder 7 through the second cartridge valve 6, and the pressure oil in the rodless cavity of the first cylinder 7 passes through the first slide valve 3 and the second three-position four Pass the reversing valve 2 to the oil discharge port T and output.

In some embodiments, a circulating oil circuit for low-pressure pumping further includes:

Pressure oil passes through the first pressure port Pd and the first control port kz1, the first hydraulic control check valve v1, the second hydraulic control check valve v2, the third hydraulic control check valve v3 and the fourth hydraulic control check valve The valve v4 is in the reverse connection state, the fifth hydraulic control check valve v5, the sixth hydraulic control check valve v6, the seventh hydraulic control check valve v7 and the eighth hydraulic control check valve v8 are all in the reverse direction In the closed state, pressure oil alternately appears at the third control port kz3 and the fourth control port kz4; or

The first pressure port Pd and the second control port kz2 have pressure oil passing through, the first hydraulic control check valve v1, the second hydraulic control check valve v2, the third hydraulic control check valve v3 and the fourth hydraulic control check valve The valve v4 is in the reverse connection state, the fifth hydraulic control check valve v5, the sixth hydraulic control check valve v6, the seventh hydraulic control check valve v7 and the eighth hydraulic control check valve v8 are all in the reverse direction In the closed state, the third control port kz3 and the fourth control port kz4 alternately present pressure oil.

In some embodiments, a circulating oil circuit for high-pressure pumping includes:

The pumped high-pressure oil input to the oil supply port P enters the rodless cavity of the first cylinder 7 through the first three-position four-way reversing valve 1 and the second slide valve 4 in turn, and the pressure oil in the rod cavity of the first cylinder 7 Enter the rod cavity of the second cylinder 8 through the first cartridge valve 5, and the pressure oil in the rodless cavity of the second cylinder 8 passes through the second slide valve 4 and the first three-position four-way reversing valve 1 to the oil discharge port T output; the pumped high-pressure oil at the oil supply port P passes through the first three-position four-way reversing valve 1 and the second slide valve 4 into the rodless cavity of the second cylinder 8, and into the rod cavity of the second cylinder 8 The pressure oil enters the rod cavity of the first cylinder 7 through the first cartridge valve 5, and the pressure oil in the rodless cavity of the first cylinder 7 passes through the second slide valve 4 and the first three-position four-way reversing valve 1 to Oil drain port T output.

In some embodiments, a circulating oil circuit for high-pressure pumping further includes:

Pressure oil passes through the second pressure port Pg and the first control port kz1, the first hydraulic control check valve v1, the second hydraulic control check valve v2, the third hydraulic control check valve v3 and the fourth hydraulic control check valve The valve v4 is in the reverse closed state, the fifth hydraulic control check valve v5, the sixth hydraulic control check valve v6, the seventh hydraulic control check valve v7 and the eighth hydraulic control check valve v8 are all in the reverse connection. In the ON state, pressure oil alternately appears at the third control port kz3 and the fourth control port kz4; or

Pressure oil passes through the second pressure port Pg and the second control port kz2, the first hydraulic control check valve v1, the second hydraulic control check valve v2, the third hydraulic control check valve v3 and the fourth hydraulic control check valve. The valve v4 is in the reverse closed state, the fifth hydraulic control check valve v5, the sixth hydraulic control check valve v6, the seventh hydraulic control check valve v7 and the eighth hydraulic control check valve v8 are all in the reverse connection. In the ON state, the third control oil port kz3 and the fourth control oil port kz4 alternately appear pressure oil.

Under the action of the first pressure port Pd and the second pressure port Pg, the hydraulic control check valves v1 to v8 are in the reverse connection state. If the first control port kz1, the second control port kz2, and the third If there is no pressure oil through the control port kz3 and the fourth control port kz4, no control oil will flow to the oil inlets p11, p12, p21, p22, p31, p32, p41 and p42, the first three-position four-way change The reversing valve 1 and the second three-position four-way reversing valve 2 are in the neutral state, pumping high-pressure oil is on standby at the oil supply port P, and the system is in a non-pumping state.

The low pressure pumping process includes:

When only the first pressure port Pd, the first control port kz1 and the third control port kz3 have pressure oil passing through, the first hydraulic control check valve v1, the second hydraulic control check valve v2, the third hydraulic control valve The control check valve v3 and the fourth hydraulic control check valve v4 are both in the reverse connection state, the fifth hydraulic control check valve v5, the sixth hydraulic control check valve v6, the seventh hydraulic control check valve v7 and the The eight-liquid control check valve v8 is in the reverse closed state. The control oil at the first control oil port kz1 flows to the second three-position four-way reversing valve 2 through the first hydraulic control single valve v1, and the second three-position four-way reversing valve 2 is connected in the left position. The pressure oil at the third control oil port kz3 flows to the first spool valve 3 through the second hydraulic control check valve v2, and the first spool valve 3 is in the left position. The pumped high-pressure oil input from the oil supply port P flows through the second three-position four-way reversing valve 2 and the first slide valve 3 to the rod cavity of the first cylinder 7 and the first cartridge valve 5. At this time, the control oil port P5 of the first cartridge valve is pressurized oil, and the first cartridge valve 5 is closed. The high-pressure oil pushes the piston of the first oil cylinder 7 to move, and the pressure oil of the rodless cavity of the first oil cylinder 7 acts on the second cartridge valve 6 and the second slide valve 4. The second cartridge valve controls the pressure-free oil at port P6, and the second cartridge valve 6 opens. The pressure oil in the rodless cavity of the first oil cylinder 7 enters the rodless cavity of the second oil cylinder 8 through the second cartridge valve 6 to push the piston to move. The pressure oil in the rod cavity of the second cylinder 8 acts on the first cartridge valve 5 and the first slide valve 3. The first cartridge valve 5 is in the closed state, the pressure oil in the rod cavity of the second cylinder 8 passes through the first slide valve 3 to the second three-position four-way reversing valve 2, and through the second three-position four-way reversing valve 2. To the drain port) output.

When the first pressure port Pd, the first control port kz1 and the fourth control port kz4 are pressure oil, the pressure oil at the fourth control port kz4 flows to the first slide through the third hydraulic control check valve v3 Valve 3, the first spool valve 3 is connected to the right position. The pumped high-pressure oil input from the oil supply port P passes through the second three-position four-way reversing valve 2, and the first slide valve 3 enters the rod cavity of the second cylinder 8, and the high-pressure oil pushes the piston of the second cylinder 8 to move. The second cartridge valve controls the pressure-free oil at port P6, and the second cartridge valve 6 opens. The pressure oil in the rodless cavity of the second oil cylinder 8 acts on the second cartridge valve 6 and enters the rodless cavity of the first oil cylinder 7 through the second cartridge valve 6 to push the piston of the first oil cylinder 7 to move. The pressure oil in the rod cavity of the first oil cylinder 7 passes through the first slide valve 3 and the second three-position four-way reversing valve 2 to the oil discharge port T for output.

When pressure oil alternates between the third control oil port kz3 and the fourth control oil port kz4, the continuous movement of the first oil cylinder 7 and the second oil cylinder 8 is realized, thereby realizing low-pressure pumping.

In some embodiments, the high-pressure pumping control step includes:

When there is only the second pressure port Pg, the first control port kz1 and the third control port kz3 have pressure oil passing through, the fifth hydraulic control check valve v5, the sixth hydraulic control check valve v6, and the seventh hydraulic control port The control check valve v7 and the eighth hydraulic control check valve v8 are in the reverse connection state, the first hydraulic control check valve v1, the second hydraulic control check valve v2, the third hydraulic control check valve v3 and the fourth hydraulic control check valve v3. The hydraulic control check valve v4 is in the reverse closed state. The pressure oil at the first control port kz1 flows through the fifth hydraulic control check valve v5 to the first three-position four-way reversing valve 1, and the pressure oil at the third control port kz3 enters through the sixth hydraulic control check valve v6 The second spool valve 4 and the second spool valve 4 are connected in the left position. The pumped high-pressure oil input to the oil supply port P flows through the first three-position four-way reversing valve 1 and the second slide valve 4 to the rodless cavity of the first cylinder 7 and the second cartridge valve 6. At this time, the second cartridge valve control port P6 is pressurized oil, and the second cartridge valve 6 is closed. The high-pressure oil pushes the piston of the first cylinder 7 to move. The pressure oil in the rod cavity of the first cylinder 7 flows to the first cartridge valve 5 and the first slide valve 3, and the second three-position four-way reversing valve 2. Because both the first hydraulic control check valve v1 and the fourth hydraulic control check valve v4 have no pressure oil, the second three-position four-way reversing valve 2 is in a closed state. The first cartridge valve controls oil port P5 without pressure oil, and the first cartridge valve 5 is in an open state. The pressure oil in the rod cavity of the first cylinder 7 flows to the rod cavity of the second cylinder 8 to push the piston of the second cylinder 8 to move. The pressure oil in the rodless cavity of the second cylinder 8 flows to the second cartridge valve 6 and the second slide valve 4. Because the second cartridge valve control port P6 is pressurized oil, the second cartridge valve 6 is closed. The pressure oil flows through the second slide valve 4 and the first three-position four-way reversing valve 1 to the oil discharge port T for output.

When the fourth control oil port kz4 is pressure oil, the pressure oil is output to the second slide valve 4 through the seventh hydraulic control check valve v7, and the second slide valve 4 is connected to the right. The pumped high-pressure oil input into the oil supply port P enters the rodless cavity of the second cylinder 8 through the first three-position four-way reversing valve 1 and the second slide valve 4, and pushes the piston of the second cylinder 8 to move. The pressure oil in the rod cavity of the second oil cylinder 8 enters the rod cavity of the first oil cylinder 7 through the first cartridge valve 5 to push the piston of the first oil cylinder 7 to move. The pressure oil in the rodless cavity of the first oil cylinder 7 passes through the second slide valve 4 and the first three-position four-way reversing valve 1 to the oil discharge port T and is output.

When pressure oil alternates between the third control oil port kz3 and the fourth control oil port kz4, the continuous movement of the first oil cylinder 7 and the second oil cylinder 8 is realized, thereby realizing high-pressure pumping.

In the embodiment of the present disclosure, the hydraulic system includes four spool valves (ie, the first three-position four-way reversing valve 1, the second three-position four-way reversing valve 2, the first spool valve 3 and the second spool valve 4), 4 groups of hydraulic control check valves (the first hydraulic control check valve v1, the second hydraulic control check valve v2, the third hydraulic control check valve v3, the fourth hydraulic control check valve v4, the fifth hydraulic control check valve Valve v5, the sixth hydraulic control check valve v6, the seventh hydraulic control check valve v7 and the eighth hydraulic control check valve v8) and two cartridge valves (the first cartridge valve 5 and the second cartridge valve 6) ).

The arrangement of the spools of the four spool valves can be:

Four spool valves (ie, the first three-position four-way reversing valve 1, the second three-position four-way reversing valve 2, the first spool valve 3, the second spool valve 4) spools are laid out flat, and the control mechanism (ie Four sets of hydraulically controlled check valves) are distributed at both ends; or

The four spool valves (ie the first three-position four-way reversing valve 1, the second three-position four-way reversing valve 2, the first spool valve 3, the second spool valve 4) are arranged in two layers before and after the valve core, and the control mechanism ( That is, four groups of hydraulically controlled one-way valves are arranged at one end.

The working logic of this hydraulic system (according to the symbols in Figure 1 and Figure 2) is as follows:

The logic relationship of low pressure pumping (oil in the small cavity of the cylinder) is: the first pressure port Pd is always connected to the pressure oil, the first control port kz1 or the second control port kz2 is always connected to the pressure oil, and the third control port kz3, The fourth control port kz4 acts on high pressure oil alternately, and the second pressure port Pg does not act on pressure oil.

The logic relationship of high pressure pumping (oil in the large cavity of the oil cylinder): the second pressure port Pg is always connected to the pressure oil, the first control port kz1 or the second control port kz2 is always connected to the pressure oil, the third control port kz3, the first The four control ports kz4 act as high pressure oil alternately, and the first pressure port Pd does not act as pressure oil.

The above embodiments of the present disclosure can achieve at least one of the following effects:

The high and low pressure automatic switching control logic device of the embodiment of the present disclosure includes a control logic composed of four sets of hydraulic control check valves, a control port assembly and two cartridge valve control ports. The hydraulic valve is internally controlled to reduce the number of solenoid valves and The number of pipelines is easy to integrate and save space.

The high-low pressure automatic switching control logic system of the embodiment of the present disclosure includes a hydraulic system and a high-low pressure automatic switching control logic device, through the aforementioned low-pressure pumping (oil in a small cavity of a cylinder) logic relationship and high pressure pumping (oil in a large cavity of a cylinder) Logical relationship to solve low-pressure pumping and high-pressure pumping as a whole.

The control method of the high and low pressure automatic switching control logic system of the embodiment of the present disclosure, by designing a high and low pressure switching system with new control logic, enables the concrete pump to easily switch from low pressure to high pressure (or high pressure to low pressure) in a short time. Switch) so as to improve the construction efficiency of the concrete pump, reduce the construction intensity of workers, and improve the overall performance of the concrete pump. The above are only the preferred embodiments of the present disclosure. It should be pointed out that for those of ordinary skill in the art, without departing from the technical principles of the present disclosure, several improvements and modifications can be made. These improvements and modifications It should also be regarded as the protection scope of the present disclosure.

Claims

A high and low voltage automatic switching control logic device, comprising a first control logic unit, a second control logic unit and a control oil port assembly; wherein

The first control logic unit is connected to the second control logic unit through the control oil port assembly;

The control oil port assembly includes a first control oil port (kz1), a second control oil port (kz2), a third control oil port (kz3), and a fourth control oil port (kz4);

The first control logic unit includes a first pressure oil port (Pd), a first hydraulic control check valve (v1), a second hydraulic control check valve (v2), a third hydraulic control check valve (v3), The fourth hydraulic control check valve (v4) and the first cartridge valve control port (P5), the first pressure port (Pd) is respectively connected to the first cartridge valve control port (P5), The control oil circuit of the first hydraulic control check valve (v1), the control oil circuit of the second hydraulic control check valve (v2), the control oil circuit of the third hydraulic control check valve (v3) and The control oil circuit of the fourth hydraulic control check valve (v4);

The second control logic unit includes a second pressure port (Pg), a fifth hydraulic control check valve (v5), a sixth hydraulic control check valve (v6), a seventh hydraulic control check valve (v7), The eighth hydraulic control check valve (v8) and the second cartridge valve control port (P6), the second pressure port (Pg) is respectively connected to the second cartridge valve control port (P6), The control oil circuit of the fifth hydraulic control check valve (v5), the control oil circuit of the sixth hydraulic control check valve (v6), the control oil circuit of the seventh hydraulic control check valve (v7) and The control oil circuit of the eighth hydraulic control check valve (v8); and

The first control oil port (kz1) is respectively connected to the oil outlet of the first hydraulic control check valve (v1) and the oil outlet of the fifth hydraulic control check valve (v5), and the second The control oil port (kz2) is respectively connected to the oil outlet of the fourth hydraulic control check valve (v4) and the oil outlet of the eighth hydraulic control check valve (v8). The third control oil port ( kz3) are respectively connected to the oil outlet of the second hydraulic control check valve (v2) and the oil outlet of the sixth hydraulic control check valve (v6), and the fourth control oil port (kz4) is respectively connected to The oil outlet of the third hydraulic control check valve (v3) and the oil outlet of the seventh hydraulic control check valve (v7).
A high and low pressure automatic switching control logic system, comprising a hydraulic system and the high and low pressure automatic switching control logic device of claim 1; wherein

The oil ports of the hydraulic system are respectively connected to the first control logic unit and the second control logic unit;

The hydraulic system includes a first three-position four-way reversing valve (1), a second three-position four-way reversing valve (2), a first slide valve (3), a second slide valve (4), a first plug Installed valve (5), second cartridge valve (6), first oil cylinder (7) and second oil cylinder (8), wherein said first three-position four-way reversing valve (1), said second three Position four-way reversing valve (2), the first spool valve (3) and the second spool valve (4) are all spool valves;

The first cartridge valve (5) is respectively connected to the rod cavity of the first oil cylinder (7), the rod cavity of the second oil cylinder (8) and the first slide valve (3). The first slide valve (3) is connected with the second three-position four-way reversing valve (2);

The second cartridge valve (6) is respectively connected to the rodless cavity of the first oil cylinder (7), the rodless cavity of the second oil cylinder (8) and the second slide valve (4), the The second slide valve (4) is connected to the first three-position four-way reversing valve (1); and

The first three-position four-way reversing valve (1) and the second three-position four-way reversing valve (2) externally pump high-pressure oil through an oil supply port (P).
The high and low voltage automatic switching control logic system according to claim 2, wherein

The first three-position four-way reversing valve (1), the second three-position four-way reversing valve (2), the first spool valve (3) and the second spool valve (4) The spool is laid out flat, the first hydraulic control check valve (v1), the second hydraulic control check valve (v2), the third hydraulic control check valve (v3), and the fourth hydraulic control check valve (v3) v4), the fifth hydraulic control check valve (v5), the sixth hydraulic control check valve (v6), the seventh hydraulic control check valve (v7) and the eighth hydraulic control check valve (v8) constitute four groups of liquid The control check valve is distributed at both ends; or

The first three-position four-way reversing valve (1), the second three-position four-way reversing valve (2), the first spool valve (3) and the second spool valve (4) The spool is arranged in two layers, the first hydraulic control check valve (v1), the second hydraulic control check valve (v2), the third hydraulic control check valve (v3), and the fourth hydraulic control check valve (v4), the fifth hydraulic control check valve (v5), the sixth hydraulic control check valve (v6), the seventh hydraulic control check valve (v7) and the eighth hydraulic control check valve (v8) constitute four groups The hydraulic control check valve is arranged at one end.
A high and low voltage automatic switching control logic system according to claim 2 or 3, wherein:

The first three-position four-way reversing valve (1) is respectively connected to the oil inlet (P11) of the fifth hydraulic control check valve (v5) and the inlet of the eighth hydraulic control check valve (v8). Oil port (P12);

The second three-position four-way reversing valve (2) is respectively connected to the oil inlet (P21) of the first hydraulic control check valve (v1) and the inlet of the fourth hydraulic control check valve (v4). Oil port (P22);

The first slide valve (3) is respectively connected to the oil inlet (P31) of the second hydraulic control check valve (v2) and the oil inlet (P32) of the third hydraulic control check valve (v3) ；

The second slide valve (4) is respectively connected to the oil inlet (P41) of the sixth hydraulic control check valve (v6) and the oil inlet (P42) of the seventh hydraulic control check valve (v7) ；

The first cartridge valve (5) is connected to the first pressure oil port (Pd) through the first cartridge valve control oil port (P5); and

The second cartridge valve (6) is connected to the second pressure oil port (Pg) through the second cartridge valve control oil port (P6).
A high and low pressure automatic switching control logic system according to claim 4, wherein a circulating oil circuit for low pressure pumping comprises:

The pumped high-pressure oil input to the oil supply port (P) sequentially enters the rod of the first oil cylinder (7) through the second three-position four-way reversing valve (2) and the first slide valve (3) The pressure oil in the rodless cavity of the first oil cylinder (7) enters the rodless cavity of the second oil cylinder (8) through the second cartridge valve (6), and the second oil cylinder (8) The pressure oil in the rod cavity of) passes through the first slide valve (3) and the second three-position four-way reversing valve (2) to the oil discharge port (T); and

The pumped high-pressure oil at the oil supply port (P) sequentially passes through the second three-position four-way reversing valve (2) and the first slide valve (3) into the rod of the second cylinder (8) The pressure oil in the rodless cavity of the second oil cylinder (8) enters the rodless cavity of the first oil cylinder (7) through the second cartridge valve (6), and the first oil cylinder (7) The pressure oil in the rod cavity of) passes through the first slide valve (3) and the second three-position four-way reversing valve (2) to the oil discharge port (T).
The high-low-pressure automatic switching control logic system according to claim 5, wherein a circulating oil circuit for the low-pressure pumping further comprises:

The first pressure oil port (Pd) and the first control oil port (kz1) have pressure oil passing through, the first hydraulic control check valve (v1), the second hydraulic control check valve (v2) ), the third hydraulic control check valve (v3) and the fourth hydraulic control check valve (v4) are both in reverse connected state, the fifth hydraulic control check valve (v5), the The sixth hydraulic control check valve (v6), the seventh hydraulic control check valve (v7) and the eighth hydraulic control check valve (v8) are all in a reverse closed state, and the third control oil port (kz3). Pressure oil alternately appears at the fourth control oil port (kz4); or

The first pressure oil port (Pd) and the second control oil port (kz2) have pressure oil passing through, the first hydraulic control check valve (v1), the second hydraulic control check valve (v2) ), the third hydraulic control check valve (v3) and the fourth hydraulic control check valve (v4) are both in reverse connected state, the fifth hydraulic control check valve (v5), the The sixth hydraulic control check valve (v6), the seventh hydraulic control check valve (v7) and the eighth hydraulic control check valve (v8) are all in a reverse closed state, and the third control oil port (kz3) and the fourth control oil port (kz4) alternately appear pressure oil.
A high and low pressure automatic switching control logic system according to claim 4, wherein a circulating oil circuit for high pressure pumping comprises:

The pumped high-pressure oil input to the oil supply port (P) sequentially enters the rodless of the first oil cylinder (7) through the first three-position four-way reversing valve (1) and the second slide valve (4) The pressure oil in the rod cavity of the first oil cylinder (7) enters the rod cavity of the second oil cylinder (8) through the first cartridge valve (5), and the second oil cylinder (8) The pressure oil in the rodless cavity of) passes through the second slide valve (4) and the first three-position four-way reversing valve (1) to the oil discharge port (T); and

The pumped high-pressure oil at the oil supply port (P) sequentially passes through the first three-position four-way reversing valve (1) and the second slide valve (4) into the rodless of the second oil cylinder (8) The pressure oil in the rod cavity of the second oil cylinder (8) enters the rod cavity of the first oil cylinder (7) through the first cartridge valve (5), and the first oil cylinder (7) The pressure oil in the rodless cavity of) passes through the second slide valve (4) and the first three-position four-way reversing valve (1) to the oil discharge port (T).
The high-low-pressure automatic switching control logic system according to claim 7, wherein a circulating oil circuit for the high-pressure pumping further comprises:

The second pressure oil port (Pg) and the first control oil port (kz1) have pressure oil passing through, the first hydraulic control check valve (v1), the second hydraulic control check valve (v2) ), the third hydraulic control check valve (v3) and the fourth hydraulic control check valve (v4) are both in a reverse closed state, the fifth hydraulic control check valve (v5), the first The six hydraulic control check valve (v6), the seventh hydraulic control check valve (v7) and the eighth hydraulic control check valve (v8) are all in the reverse connection state, and the third control oil port (kz3). Pressure oil alternately appears at the fourth control oil port (kz4); or

The second pressure oil port (Pg) and the second control oil port (kz2) have pressure oil passing through, the first hydraulic control check valve (v1), the second hydraulic control check valve (v2) ), the third hydraulic control check valve (v3) and the fourth hydraulic control check valve (v4) are both in a reverse closed state, the fifth hydraulic control check valve (v5), the first The six hydraulic control check valve (v6), the seventh hydraulic control check valve (v7) and the eighth hydraulic control check valve (v8) are all in the reverse connection state, and the third control oil port (kz3). Pressure oil alternately appears at the fourth control oil port (kz4).
A control method based on the high and low voltage automatic switching control logic system according to any one of claims 2 to 8, comprising:

Low-pressure pumping control steps; and

High-pressure pumping control steps.
The control method of a high and low pressure automatic switching control logic system according to claim 9, wherein the low pressure pumping control step comprises:

When only the first pressure port (Pd), the first control port (kz1) and the third control port (kz3) have pressure oil passing through, the first hydraulic control check valve (v1), the second hydraulic control The one-way valve (v2), the third hydraulic-controlled one-way valve (v3) and the fourth hydraulic-controlled one-way valve (v4) are all in the reverse connection state. The fifth hydraulic-controlled one-way valve (v5), the sixth hydraulic The control check valve (v6), the seventh hydraulic control check valve (v7) and the eighth hydraulic control check valve (v8) are in the reverse closed state, and the control oil at the first control port (kz1) passes through the first liquid The control single valve (v1) flows to the left position of the second three-position four-way reversing valve (2), and the pressure oil at the third control port (kz3) flows to the first slide through the second hydraulic control check valve (v2) The valve (3) is in the left position, and the pumped high-pressure oil input from the oil supply port (P) flows through the second three-position four-way reversing valve (2) and the first slide valve (3) to the first cylinder (7). The rod cavity and the first cartridge valve (5). At this time, the control oil port (P5) of the first cartridge valve is pressurized oil, the first cartridge valve (5) is closed, and the high pressure oil pushes the piston of the first cylinder (7) Movement, the pressure oil in the rodless cavity of the first cylinder (7) acts on the second cartridge valve (6) and the second slide valve (4), the second cartridge valve controls the port (P6) without pressure oil, The second cartridge valve (6) is opened, and the pressure oil in the rodless cavity of the first cylinder (7) enters the rodless cavity of the second cylinder (8) through the second cartridge valve (6), pushing the piston to move, and the second cylinder (8) The pressure oil with the rod cavity acts on the first cartridge valve (5) and the first slide valve (3), the first cartridge valve (5) is in the closed state, and the second cylinder (8) has The pressure oil in the rod cavity is output through the first slide valve (3) to the second three-position four-way reversing valve (2), and the second three-position four-way reversing valve (2) to the oil discharge port (T);

When the first pressure port (Pd), the first control port (kz1) and the fourth control port (kz4) are pressure oil, the pressure oil at the fourth control port (kz4) passes through the third hydraulic control unit The direction valve (v3) flows to the right position of the first spool valve (3), and the pumped high-pressure oil input from the oil supply port (P) passes through the second three-position four-way reversing valve (2) and the first spool valve (3) Enter the rod cavity of the second cylinder (8), the high pressure oil pushes the piston of the second cylinder (8), the second cartridge valve controls the oil port (P6) without pressure oil, the second cartridge valve (6) opens, and the second cartridge valve (6) opens. The pressure oil in the rodless cavity of the second cylinder (8) acts on the second cartridge valve (6), passes through the second cartridge valve (6) and enters the rodless cavity of the first cylinder (7), pushing the first cylinder ( 7) The piston moves, the pressure oil in the rod cavity of the first oil cylinder (7) passes through the first slide valve (3) and the second three-position four-way reversing valve (2) to the oil discharge port (T) ；

When pressure oil alternately appears at the third control oil port (kz3) and the fourth control oil port (kz4), the continuous movement of the first oil cylinder (7) and the second oil cylinder (8) is realized, thereby realizing low-pressure pumping.
The control method of a high and low pressure automatic switching control logic system according to claim 9, wherein the high pressure pumping control step comprises:

When only the second pressure port (Pg), the first control port (kz1) and the third control port (kz3) have pressure oil passing through, the fifth hydraulic control check valve (v5) and the sixth hydraulic control The check valve (v6), the seventh hydraulic control check valve (v7) and the eighth hydraulic control check valve (v8) are in the reverse connection state. The first hydraulic control check valve (v1), the second hydraulic control The one-way valve (v2), the third hydraulic-controlled one-way valve (v3) and the fourth hydraulic-controlled one-way valve (v4) are in the reverse closed state, and the pressure oil at the first control port (kz1) is controlled by the fifth hydraulic The check valve (v5) flows to the first three-position four-way reversing valve (1), and the pressure oil at the third control port (kz3) enters the second slide valve (4) through the sixth hydraulic control check valve (v6) ) In the left position, the pumped high-pressure oil input to the oil supply port (P) flows through the first three-position four-way reversing valve (1) and the second slide valve (4) to the rodless cavity and At the second cartridge valve (6), the second cartridge valve control port (P6) is pressurized oil at this time, the second cartridge valve (6) is closed, and the high pressure oil pushes the piston of the first cylinder (7) to move, The pressure oil in the rod cavity of the first cylinder (7) flows to the first cartridge valve (5) and the first slide valve (3), and the second three-position four-way reversing valve (2), because the first fluid The control check valve (v1) and the fourth hydraulic control check valve (v4) have no pressure oil, the second three-position four-way reversing valve (2) is in the closed state, and the first cartridge valve controls the oil port ( P5) There is no pressure oil, the first cartridge valve (5) is open, the pressure oil in the rod cavity of the first cylinder (7) flows to the rod cavity of the second cylinder (8) to push the second cylinder (8) The piston moves, the pressure oil in the rodless cavity of the second cylinder (8) flows to the second cartridge valve (6) and the second slide valve (4), because the second cartridge valve control oil port (P6) is Pressurized oil, the second cartridge valve (6) is closed, the pressurized oil flows through the second slide valve (4) and the first three-position four-way reversing valve (1) to the oil discharge port (T) for output;

When the fourth control port (kz4) is pressure oil, the pressure oil is output to the right position of the second slide valve (4) through the seventh hydraulic control check valve (v7), and the pumping port (P) is input The high-pressure oil passes through the first three-position four-way reversing valve (1) and the second slide valve (4) into the rodless cavity of the second cylinder (8), pushing the piston of the second cylinder (8) to move, and the second cylinder (8) The pressure oil in the rod cavity of) enters the rod cavity of the first cylinder (7) through the first cartridge valve (5), pushing the piston of the first cylinder (7) to move, and the rodless cavity of the first cylinder (7) The pressure oil in the medium passes through the second slide valve (4) and the first three-position four-way reversing valve (1) to the oil discharge port (T);

When pressure oil alternates between the third control oil port (kz3) and the fourth control oil port (kz4), the continuous movement of the first oil cylinder (7) and the second oil cylinder (8) is realized, thereby realizing high-pressure pumping.