A switchable fine-tuning and fast-moving hydraulic system

Abstract

The present invention relates to a switchable, fine-tuning, and fast-action hydraulic system, comprising a hydraulic pump, a hydraulic actuator, and a hydraulic oil tank. The hydraulic pump's oil intake port S and oil discharge port L1 are both connected to the hydraulic oil tank. The system also includes a switching valve group and a load-sensing valve. The hydraulic pump's oil outlet port P is respectively connected to the oil inlet port P of the switching valve group and the load-sensing valve. The oil return port T of the switching valve group and the load-sensing valve are both connected to the hydraulic oil tank. The oil outlets A and B of the switching valve group and the oil outlets A and B of the load-sensing valve are both connected to the hydraulic actuator. The LS port of the switching valve group is connected to the LS port of the load-sensing valve. The LSV port of the switching valve group is connected to the LSP port of the hydraulic pump. The present invention utilizes a low-flow load-sensing valve and a high-flow electro-hydraulic directional valve to achieve switchable adjustment between fine and fast action of the hydraulic actuator, achieving both fine and fast action. High-flow fast action is highly efficient and energy-saving, while also being low-cost and reliable.

Description

Technical Field

[0001] The present invention relates to a hydraulic system, in particular to a switchable fine-tuning and fast-moving hydraulic system. Background Art

[0002] Hydraulic systems usually have hydraulic actuators, such as hydraulic motors and hydraulic cylinders. In actual use, hydraulic motors or hydraulic cylinders need to perform slight and rapid movements according to actual conditions.

[0003] To meet these requirements, load-sensing and electric proportional variable systems are currently the mainstream hydraulic systems. However, when hydraulic systems are used for high-flow, rapid movements, their flow resolution is very low, resulting in poor micro-movement performance. Furthermore, because the system pressure in load-sensing systems is higher than the load pressure, the load-sensing circuit experiences significant power loss and low energy consumption under high-flow conditions.

[0004] The Chinese invention patent entitled "A push-pull micro-control device for a horizontal directional drilling rig power head and its control method" with application number 202110957754.6 records the technical solution that "the present invention provides a push-pull micro-control device for a horizontal directional drilling rig power head, including: a hydraulic system, a controller, an instruction system and an execution system, the instruction system including a push-pull micro-switch for selecting the micro-motion state of the horizontal directional drilling rig head, a push-pull high-speed switch for selecting the high-speed state of the horizontal directional drilling rig head, and a push-pull handle for controlling the forward and backward movement of the horizontal directional drilling rig head; the input end of the controller is electrically connected to the push-pull handle, the push-pull high-speed switch and the push-pull micro-switch, the output end of the controller is connected to the execution system, and the execution system calls the hydraulic system to realize the control of the horizontal directional drilling rig power head."

[0005] The above solution takes micro-motion into consideration and uses two sets of load-sensitive valves. Small flow is used for micro-motion, and large flow valves are used for fast motion. This will significantly increase the cost and fail to solve the problems of large power loss and low efficiency at high flow. Summary of the Invention

[0006] The objects of the present invention are:

[0007] A switchable fine-tuning and fast-action hydraulic system is designed. Through a small-flow load-sensitive valve and a large-flow electro-hydraulic reversing valve, the switchable adjustment of the micro-motion and fast-action of the hydraulic actuator can be realized, achieving both micro-motion and fast-action. It is efficient and energy-saving when the large-flow fast-action is used, and has low cost and reliable performance.

[0008] In order to achieve the above object, the present invention provides the following technical solutions:

[0009] A switchable fine-tuning and fast-acting hydraulic system includes a hydraulic pump, a hydraulic actuator and a hydraulic oil tank, wherein the oil suction port S and the oil discharge port L1 of the hydraulic pump are both connected to the hydraulic oil tank; the system also includes a switching valve group and a load-sensing valve; the oil outlet P of the hydraulic pump is respectively connected to the oil inlet P of the switching valve group and the load-sensing valve, and the oil return port T of the switching valve group and the load-sensing valve are both connected to the hydraulic oil tank, the oil outlets A and B of the switching valve group and the oil outlets A and B of the load-sensing valve are both connected to the hydraulic actuator; the LS port of the switching valve group is connected to the LS port of the load-sensing valve; and the LSV port of the switching valve group is connected to the LSP port of the hydraulic pump.

[0010] Furthermore, the switching valve group includes a proportional relief valve, a two-position three-way reversing valve, a throttle valve and an electro-hydraulic reversing valve; the oil inlet P, oil return port T, oil outlet A and oil outlet B of the electro-hydraulic reversing valve are respectively connected to the oil inlet P, oil return port T, oil outlet A and oil outlet B of the switching valve group; the electro-hydraulic reversing valve is specifically a three-position four-way reversing valve.

[0011] Furthermore, the oil inlet P of the throttle valve is connected to the oil outlet P of the hydraulic pump, and the oil outlet T of the throttle valve is connected to the port 2 of the two-position three-way reversing valve; the port 1 of the two-position three-way reversing valve is connected to the LSV port of the switching valve group, and the port 3 of the two-position three-way reversing valve is connected to the LS port of the switching valve group.

[0012] Furthermore, the oil inlet P of the proportional relief valve is connected to port 1 of the two-position three-way reversing valve, and the oil return port T of the proportional relief valve is connected to the oil return port T of the electro-hydraulic reversing valve.

[0013] Furthermore, the hydraulic pump includes a main pump and a control valve, and the control valve is connected to the main pump and the hydraulic oil tank; the control valve includes a load-sensitive control unit and an electric proportional control unit.

[0014] Furthermore, the main pump is connected to the load-sensing control unit and the electric proportional control unit respectively, the electric proportional control unit is connected to the load-sensing control unit and the hydraulic oil tank respectively, and the spring control end oil port of the load-sensing control unit is the LSP port of the hydraulic pump.

[0015] The beneficial effects of the present invention are: a switchable fine-tuning and fast-action hydraulic system, which can realize the switching adjustment of the micro-motion and fast-action of the hydraulic actuator through a small-flow load-sensitive valve and a large-flow switching valve group including an electro-hydraulic reversing valve, and realize the micro-motion and fast-action of the hydraulic actuator. At the same time, it is efficient and energy-saving during large-flow fast-action, and compared with existing hydraulic systems, it has low cost, improved efficiency and reliable performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1The figure is a schematic diagram of the overall connection of a switchable fine-tuning and fast-moving hydraulic system of the present invention.

[0017] Figure 2 The figure is a schematic diagram of a hydraulic pump of a switchable fine-tuning and fast-action hydraulic system according to the present invention.

[0018] Figure 3 The figure is a schematic diagram of a switching valve group of a switchable fine-tuning and fast-acting hydraulic system according to the present invention.

[0019] In the figure: 1, hydraulic pump; 10, main pump; 11, control valve; 111, load sensing control unit; 112, electric proportional control unit;

[0020] 2. Switching valve group; 3. Load-sensing valve; 4. Hydraulic actuator; 5. Hydraulic oil tank; 6. Proportional relief valve; 7. Two-position three-way reversing valve; 8. Throttle valve; 9. Electro-hydraulic reversing valve. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0022] refer to Figures 1 to 3 , a switchable fine-tuning and fast-moving hydraulic system, including a hydraulic pump 1, a hydraulic actuator 4 and a hydraulic oil tank 5. The oil suction port S and the oil discharge port L1 of the hydraulic pump 1 are both connected to the hydraulic oil tank 5, and the hydraulic pump 1 is used for oil supply; it also includes a switching valve group 2 and a load-sensing valve 3. The switching valve group 2 is used to realize the fast-moving control of the hydraulic actuator 4, and the load-sensing valve 3 is used to realize the micro-motion control of the hydraulic actuator 4. The load-sensing valve 3 is specifically a small-flow valve group that can accurately control the output flow accuracy; the oil outlet of the hydraulic pump 1 P is respectively connected to the oil inlet P of the switching valve group 2 and the load sensing valve 3, the hydraulic pump 1 supplies oil to the switching valve group 2 and the load sensing valve 3, the return oil port T of the switching valve group 2 and the load sensing valve 3 are both connected to the hydraulic oil tank 5, the oil outlets A and B of the switching valve group 2 and the oil outlets A and B of the load sensing valve 3 are both connected to the hydraulic actuator 4; the LS port of the switching valve group 2 is connected to the LS port of the load sensing valve 3 for transmitting load sensitive signals; the LSV port of the switching valve group 2 is connected to the LSP port of the hydraulic pump 1 for transmitting control signals.

[0023] The switching valve group 2 includes a proportional relief valve 6, a two-position three-way directional valve 7, a throttle valve 8 and an electro-hydraulic directional valve 9; the oil inlet P, oil return port T, oil outlet A and oil outlet B of the electro-hydraulic directional valve 9 are respectively connected to the oil inlet P, oil return port T, oil outlet A and oil outlet B of the switching valve group 2; the electro-hydraulic directional valve 9 is specifically a three-position four-way directional valve, and the electro-hydraulic directional valve 9 is used to control the oil flow direction of the hydraulic actuator 4, thereby realizing actions in different directions.

[0024] The oil inlet P of the throttle valve 8 is connected to the oil outlet P of the hydraulic pump 1, and the oil outlet T of the throttle valve 8 is connected to the 2 port of the two-position three-way reversing valve 7, and the throttle valve 8 plays a throttling role; the 1 port of the two-position three-way reversing valve 7 is connected to the LSV port of the switching valve group 2, and the 3 port of the two-position three-way reversing valve 7 is connected to the LS port of the switching valve group 2, and the coil of the two-position three-way reversing valve 7 is a3.

[0025] The oil inlet P of the proportional relief valve 6 is connected to the port 1 of the two-position three-way reversing valve 7, and the oil return port T of the proportional relief valve 6 is connected to the oil return port T of the electro-hydraulic reversing valve 9. The proportional relief valve 6 is used to control the system pressure, and the coil of the proportional relief valve 6 is a2.

[0026] The hydraulic pump 1 includes a main pump 10 and a control valve 11. The control valve 11 is connected to the main pump 10 and the hydraulic oil tank 5. The main pump 10 is used to supply oil in the hydraulic oil tank 5. The control valve 11 includes a load-sensitive control unit 111 and an electric proportional control unit 112. The coil of the electric proportional control unit 112 is a1.

[0027] The main pump 10 is respectively connected to the load-sensing control unit 111 and the electric proportional control unit 112. The electric proportional control unit 112 is respectively connected to the load-sensing control unit 111 and the hydraulic oil tank 5. The spring control end oil port of the load-sensing control unit 111 is the LSP port of the hydraulic pump 1. When in the fast-acting mode, the hydraulic oil of the main pump 10 is supplied to the LSV port of the switching valve group 2 through the throttle valve 8 and the two-position three-way reversing valve 7, and is finally transmitted to the LSP port of the hydraulic pump 1 to achieve feedback.

[0028] The working principle of the present invention is as follows: when the hydraulic actuator 4 needs fine-tuning or micro-movement, a large current is input to the coil a1 of the electric proportional control unit 112, and the coil a3 of the two-position three-way reversing valve 7 is energized. The oil output from the oil outlet P of the main pump 10 is blocked by the electric proportional control unit 112 and the two-position three-way reversing valve 7, that is, the switching valve group 2 is in an inoperative state; the oil outlet P of the main pump 10 is input to the oil inlet P of the load-sensing valve 3, and the load-sensing valve 3 controls the oil flow and flow direction of the hydraulic actuator 4, thereby controlling the movement direction of the hydraulic actuator 4 and realizing micro-movement; the system pressure can be limited by controlling the current of the coil a2 of the proportional relief valve 6.

[0029] When the hydraulic actuator 4 needs to move quickly, the a3 coil of the two-position three-way reversing valve 7 is in a de-energized state, and the hydraulic oil supplied by the main pump 10 directly enters the electro-hydraulic reversing valve 9. By controlling the coil a4 or coil a5 of the electro-hydraulic reversing valve 9, the movement direction of the hydraulic actuator 4 can be controlled; the movement speed of the hydraulic actuator 4 is controlled by controlling the input current of the coil a1 of the electric proportional control unit 112, and the overall pressure of the system can be limited by controlling the current of the coil a2 of the proportional relief valve 6; at this time, the main pump 10 supplies oil directly to the hydraulic actuator 4 through the electro-hydraulic reversing valve 9 of the switching valve group 2, so the oil supply pressure of the main pump 10 is the same as the pressure of the hydraulic actuator 4, and there is no pressure difference of the load-sensitive system, so the power loss is low and the system is more efficient.

[0030] In the present invention, unless otherwise expressly specified or limited, the terms "connected," "connected," "fixed," etc. should be understood in a broad sense. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0031] The above embodiments are used to further illustrate the present invention, but the present invention is not limited to these specific embodiments. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be understood to be within the scope of protection of the present invention.

Claims

1. A switchable fine-tuning and fast-acting hydraulic system, comprising a hydraulic pump (1), a hydraulic actuator (4), and a hydraulic oil tank (5), wherein the oil suction port S and the oil discharge port L1 of the hydraulic pump (1) are both connected to the hydraulic oil tank (5); characterized in that: It also includes a switching valve group (2) and a load sensing valve (3); the oil outlet P of the hydraulic pump (1) is connected to the oil inlet P of the switching valve group (2) and the load sensing valve (3) respectively, the return oil port T of the switching valve group (2) and the load sensing valve (3) are both connected to the hydraulic oil tank (5), the oil outlets A and B of the switching valve group (2) and the oil outlets A and B of the load sensing valve (3) are both connected to the hydraulic actuator (4); the LS port of the switching valve group (2) is connected to the LS port of the load sensing valve (3); the LSV port of the switching valve group (2) is connected to the LSP port of the hydraulic pump (1); the switching valve group (2) includes a proportional relief valve (6), a two-position three-way reversing valve ( 7), a throttle valve (8) and an electro-hydraulic directional valve (9); the oil inlet P, the oil return port T, the oil outlet A and the oil outlet B of the electro-hydraulic directional valve (9) are respectively connected to the oil inlet P, the oil return port T, the oil outlet A and the oil outlet B of the switching valve group (2); the electro-hydraulic directional valve (9) is specifically a three-position four-way directional valve; the oil inlet P of the throttle valve (8) is connected to the oil outlet P of the hydraulic pump (1), and the oil outlet T of the throttle valve (8) is connected to the 2nd port of the two-position three-way directional valve (7); the 1st port of the two-position three-way directional valve (7) is connected to the LSV port of the switching valve group (2), and the 3rd port of the two-position three-way directional valve (7) is connected to the LS port of the switching valve group (2).

2. A switchable fine-tuning and fast-acting hydraulic system according to claim 1, characterized in that: The oil inlet P of the proportional relief valve (6) is connected to the port 1 of the two-position three-way reversing valve (7), and the oil return port T of the proportional relief valve (6) is connected to the oil return port T of the electro-hydraulic reversing valve (9).

3. The switchable fine-tuning and fast-acting hydraulic system according to claim 2, characterized in that: The hydraulic pump (1) comprises a main pump (10) and a control valve (11), wherein the control valve (11) is connected to the main pump (10) and the hydraulic oil tank (5); the control valve (11) comprises a load-sensing control unit (111) and an electric proportional control unit (112).

4. The switchable fine-tuning and fast-acting hydraulic system according to claim 3, characterized in that: The main pump (10) is connected to a load-sensing control unit (111) and an electric proportional control unit (112), respectively. The electric proportional control unit (112) is connected to the load-sensing control unit (111) and a hydraulic oil tank (5), respectively. The spring control end oil port of the load-sensing control unit (111) is the LSP port of the hydraulic pump (1).

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