Self-control type energy recycling structure and hydraulic excavator carrying same

Abstract

The invention relates to a self-control type energy recycling structure and a hydraulic excavator carrying the structure, and aims to solve the technical problem that the load is increased due to energy recycling of a conventional multi-way valve, and the technical scheme is that the self-control type energy recycling structure comprises a two-way control retaining valve unit and a main valve unit; the two-way control holding valve unit comprises two holding valve modules, each holding valve module comprises a control valve and a one-way valve which are connected with a pilot control port, an oil return port and an energy recovery oil inlet respectively, the main valve unit comprises a shuttle valve and a five-position four-way reversing valve, an oil inlet of the shuttle valve is connected with oil outlets of the two one-way valves respectively, and an oil outlet of the shuttle valve is connected with an oil outlet of the five-position four-way reversing valve. And an oil outlet is connected with an oil inlet and a control end of the five-position four-way reversing valve, and is connected with an energy recovery oil outlet and an oil return port of the main valve unit. All the modules are fused in the valve body, energy to be recycled is fed back to a load input port through pressure feedback of the valve, and the effect of energy recycling is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydraulic systems for engineering machinery, and in particular relates to a self-controlled energy recovery and reuse structure and a hydraulic excavator equipped with the structure. Background Art

[0002] Nowadays, construction machinery is widely used. During the operation of construction machinery, a lot of energy is wasted, resulting in low energy utilization, high operating costs, and not in line with the trend of energy conservation and environmental protection. Traditional construction machinery lacks an efficient energy recovery mechanism and urgently needs to be improved.

[0003] In the hydraulic system, conventional slice-type multi-way valves need to add a load-sensitive element separately to recover energy through external control. The weight of the valve will also increase, resulting in higher transportation costs. Impact will occur during operation, affecting the smooth operation of the load, resulting in poor pressure maintenance and a risk of leakage. Summary of the invention

[0004] The object of the present invention is to solve the above-mentioned problems and to provide a self-controlled energy recovery and reuse structure and a hydraulic excavator equipped with the structure.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: A self-controlled energy recovery and reuse structure, comprising a bidirectional control holding valve unit and a main valve unit; The two-way control holding valve unit includes a first holding valve module I and a second holding valve module II, the first holding valve module I includes a first control valve and a first non-return valve, the second holding valve module II includes a second control valve and a second non-return valve, the two-way control holding valve unit is provided with a first pilot control port PX, a second pilot control port PY, a first oil return port T1, a first energy recovery oil inlet PR and a second energy recovery oil inlet PH, the control end of the first control valve is connected to the first pilot control port PX, the control end of the second control valve is connected to the second pilot control port PY, the first oil return port T1 is connected to the oil return ports of the first control valve and the second control valve, the oil inlets of the first non-return valve and the second non-return valve are connected to the hydraulic system to be recovered energy, the spring chamber and the oil inlet cavity of the first non-return valve are connected through the first control valve, the spring chamber and the oil inlet cavity of the second non-return valve are connected through the second control valve, the first energy recovery oil inlet PR is connected to the oil inlet of the first non-return valve, and the second energy recovery oil inlet PH is connected to the oil inlet of the second non-return valve; The main valve unit is provided with a first energy recovery oil outlet P, a second energy recovery oil outlet A, a second oil return port T and a control port P1, including a shuttle valve and a five-position four-way reversing valve. The a port of the shuttle valve is connected to the oil outlet of the first one-way valve, the b port is connected to the oil outlet of the second one-way valve, the c port is connected to the oil inlet and the control end d of the five-position four-way reversing valve, the first energy recovery oil outlet P, the second energy recovery oil outlet A, and the second oil return port T are connected to the oil outlet of the five-position four-way reversing valve, and the control port P1 is connected to the control end e of the five-position four-way reversing valve.

[0006] Furthermore, the five-position four-way reversing valve is also provided with a transition function structure on the basis of a conventional reversing valve.

[0007] Furthermore, a first damper is installed in the oil passage between the c port of the shuttle valve and the control end d of the five-position four-way reversing valve, and a second damper is installed in the oil passage between the control port P1 and the control end e of the five-position four-way reversing valve.

[0008] A hydraulic excavator is equipped with a self-controlled energy recovery and reuse structure.

[0009] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention integrates each unit module inside the valve body, and returns the energy to be recovered to the load input port through the energy recovery structure through the valve's own pressure feedback, thereby achieving the effect of energy recovery and utilization, and can reduce the weight of the valve body and realize lightweight valve body; 2. The five-position four-way reversing valve of the present invention adds a transition function on the basis of the conventional reversing valve, thereby avoiding the impact of the impact generated during the reversing process on the load action, making the actuator action more stable, and making the load movement smooth and impact-free; 3. The oil inlet pressure of the one-way valve of the present invention acts on the one-way valve spring chamber through the control valve, and a reliable and stable seal is formed under the pressure of the one-way valve spring chamber to achieve the purpose of zero leakage, while blocking the connection of the oil circuit to form a reliable load holding function. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic diagram of the principle of the present invention when there is no load (load holding function); Figure 2 It is a schematic diagram of the principle of energy recovery to the main oil circuit when the boom of a hydraulic excavator is retracted and moves downward; Figure 3 It is a schematic diagram of the principle of energy recovery to other auxiliary actuators when the boom of a hydraulic excavator is retracted and moves downward; Figure 4 It is a schematic diagram of the principle of the hydraulic excavator's boom when it is retracted and moves upward; Figure 5It is a schematic diagram of the principle of energy recovery to the main oil circuit when the bucket arm of a hydraulic excavator swings outward and moves downward; Figure 6 It is a schematic diagram of the principle of energy recovery to other auxiliary actuators when the bucket arm of a hydraulic excavator swings outward and moves downward; Figure 7 It is a schematic diagram of the principle of the bucket arm of a hydraulic excavator swinging outward and moving upward; In the figure: I, first holding valve module; II, second holding valve module; 1, first control valve; 2, second control valve; 3, first non-return valve; 4, second non-return valve; 5, shuttle valve; 6, five-position four-way reversing valve; 7, first damper; 8, second damper; PX, first pilot control port; PY, second pilot control port; T1, first oil return port; PR, first energy recovery oil inlet; PH, second energy recovery oil inlet; P, first energy recovery oil outlet; A, second energy recovery oil outlet; T, second oil return port; P1, control port. DETAILED DESCRIPTION

[0011] The present invention will be further described below in conjunction with the accompanying drawings and embodiments. Example

[0012] A self-controlled energy recovery and reuse structure, comprising a bidirectional control holding valve unit and a main valve unit; The two-way control holding valve unit includes a first holding valve module I and a second holding valve module II. The first holding valve module I includes a first control valve 1 and a first non-return valve 3. The second holding valve module II includes a second control valve 2 and a second non-return valve 4. The two-way control holding valve unit is provided with a first pilot control port PX, a second pilot control port PY, a first oil return port T1, a first energy recovery oil inlet PR and a second energy recovery oil inlet PH. The control end of the first control valve 1 is connected to the first pilot control port PX, and the control end of the second control valve 2 is connected to the second pilot control port PY. The first oil return port T1 is connected to the oil return ports of the first control valve 1 and the second control valve 2. The oil inlets of the first non-return valve 3 and the second non-return valve 4 are connected to the hydraulic system to be recovered. The spring chamber and the oil inlet cavity of the first non-return valve 3 are connected through the first control valve 1, and the spring chamber and the oil inlet cavity of the second non-return valve 4 are connected through the second control valve 2. The first energy recovery oil inlet PR is connected to the oil inlet of the first non-return valve 3, and the second energy recovery oil inlet PH is connected to the oil inlet of the second non-return valve 4. The main valve unit is provided with a first energy recovery oil outlet P, a second energy recovery oil outlet A, a second oil return port T and a control port P1, including a shuttle valve 5 and a five-position four-way reversing valve 6, wherein the a port of the shuttle valve 5 is connected to the oil outlet of the first check valve 3, the b port is connected to the oil outlet of the second check valve 4, the c port is connected to the oil inlet and the control end d of the five-position four-way reversing valve 6, and a first damper 7 is installed in the oil passage between the c port of the shuttle valve 5 and the control end d of the five-position four-way reversing valve 6, and the five-position four-way reversing valve 6 is connected to the oil outlet of the first check valve 3, the b port is connected to the oil outlet of the second check valve 4, and the c port is connected to the oil inlet and the control end d of the five-position four-way reversing valve 6. The reversing valve 6 is further provided with a transition function structure on the basis of a conventional reversing valve, so as to avoid the influence of the impact generated during the reversing process on the load action and make the actuator action more stable. The first energy recovery oil outlet P, the second energy recovery oil outlet A, and the second oil return port T are connected to the oil outlet of the five-position four-way reversing valve 6, the control port P1 is connected to the control end e of the five-position four-way reversing valve 6, and a second damper 8 is installed in the oil passage between the control port P1 and the control end e of the five-position four-way reversing valve 6. Example

[0013] A hydraulic excavator equipped with the automatic control energy recovery and reuse structure is taken as an example of the inward and outward swing of the excavator system boom; wherein, the boom rod cavity in the hydraulic excavator system is connected to the first energy recovery oil inlet PR, the boom rodless cavity is connected to the second energy recovery oil inlet PH, the main oil circuit in the excavator system is connected to the first energy recovery oil outlet P, other auxiliary actuators in the excavator system are connected to the second energy recovery oil outlet A, the oil tank in the excavator system is connected to the second oil return port T, the control port P1 is connected to the oil outlet of the pump, the pressure at the control end d of the five-position four-way reversing valve 6 is Pd, the pressure at the control end e is P1, and the pressure difference between the two ends △P=Pd-P1.

[0014] Working principle of the present invention: When the system is in the initial state, there is no pilot pressure on the first pilot control port PX and the second pilot control port PY, the spring chamber and the oil inlet of the first check valve 3 in the first holding valve module I are connected through the first control valve 1, and the spring chamber and the oil inlet of the second check valve 4 in the second holding valve module II are connected through the second control valve 2. In this state, the boom chamber pressure oil flows through the first energy recovery oil inlet PR to the oil inlet of the first check valve 3, and the boom non-rod chamber pressure oil flows through the second energy recovery oil inlet PH to the oil inlet of the second check valve 4.

[0015] like Figure 1 As shown, the oil inlet pressure of the check valve acts on the spring chamber of the check valve through the control valve, and a reliable and stable seal is formed under the pressure of the spring chamber of the check valve to achieve the purpose of zero leakage; at the same time, the connection of the oil circuit is blocked to form a reliable load holding function.

[0016] like Figure 2As shown, when the boom is retracted and moves downward, the first pilot control port PX is connected to the pressure oil, the first control valve 1 works in the left position, the spring chamber of the first check valve 3 is connected to the first oil return port T1, the first check valve 3 is opened, the a port of the shuttle valve 5 is connected to the c port, and the boom chamber pressure oil enters the oil inlet of the first check valve 3 through the first energy recovery oil inlet port PR, enters the shuttle valve 5 from the oil outlet of the first check valve 3, and enters the oil inlet of the five-position four-way reversing valve 6 through the shuttle valve 5. At this time, the pressure difference between the control end d and the control end e of the five-position four-way reversing valve 6 is △P1, and the oil outlet of the five-position four-way reversing valve 6 is connected to the first energy recovery oil outlet P, and returns to the main oil circuit of the system.

[0017] like Figure 3 As shown, when the pressure difference △P1 drops to △P2, the oil outlet of the five-position four-way reversing valve 6 is connected to the second energy recovery oil outlet A, and energy enters other auxiliary actuators to drive other auxiliary actuators to operate or accelerate the operation speed of other auxiliary actuators.

[0018] like Figure 4 As shown, when the boom is retracted and moves upward, the first pilot control port PX is connected to the pressure oil, the first control valve 1 works in the left position, the spring chamber of the first check valve 3 is connected to the first oil return port T1, the first check valve 3 is opened, the a port of the shuttle valve 5 is connected to the c port, and the boom chamber pressure oil enters the oil inlet of the first check valve 3 through the first energy recovery oil inlet port PR, enters the shuttle valve 5 from the oil outlet of the first check valve 3, and enters the oil inlet of the five-position four-way reversing valve 6 through the shuttle valve 5. At this time, the pressure difference between the control end d and the control end e of the five-position four-way reversing valve 6 is reduced to △P3, and the oil outlet of the five-position four-way reversing valve 6 is connected to the second oil return port T and returns to the oil tank.

[0019] like Figure 5 As shown, when the boom swings outward and moves downward, the second pilot control port PY is connected to the pressure oil, the second control valve 2 works in the left position, the spring chamber of the second one-way valve 4 is connected to the first oil return port T1, the second one-way valve 4 is opened, the port b of the shuttle valve 5 is connected to the port c, and the pressure oil in the boom rodless chamber enters the oil inlet of the second one-way valve 4 through the second energy recovery oil inlet PH, enters the shuttle valve 5 from the oil outlet of the second one-way valve 4, and enters the oil inlet of the five-position four-way reversing valve 6 through the shuttle valve 5. At this time, the pressure difference between the control end d and the control end e of the five-position four-way reversing valve 6 is △P1, and the oil outlet of the five-position four-way reversing valve 6 is connected to the first energy recovery oil outlet P, and returns to the main oil circuit of the system.

[0020] like Figure 6 As shown, when the pressure difference drops to △P2, the oil outlet of the five-position four-way reversing valve 6 is connected to the second energy recovery oil outlet A, and energy enters other auxiliary actuators to drive other auxiliary actuators to operate or accelerate the operation speed of other auxiliary actuators.

[0021] like Figure 7As shown, when the boom swings outward and moves upward, the second pilot control port PY is connected to the pressure oil, the second control valve 2 works in the left position, the spring chamber of the second one-way valve 4 is connected to the first oil return port T1, the second one-way valve 4 is opened, the port b of the shuttle valve 5 is connected to the port c, and the pressure oil in the boom rodless chamber enters the oil inlet of the second one-way valve 4 through the second energy recovery oil inlet PH, enters the shuttle valve 5 from the oil outlet of the second one-way valve 4, and enters the oil inlet of the five-position four-way reversing valve 6 through the shuttle valve 5. At this time, the pressure difference between the control end d and the control end e of the five-position four-way reversing valve 6 drops to △P3, and the oil outlet of the five-position four-way reversing valve 6 is connected to the second oil return port T and returns to the oil tank.

Claims

1. A self-controlled energy recovery and reuse structure, characterized in that: It includes a bidirectional control holding valve unit and a main valve unit; The two-way control holding valve unit comprises a first holding valve module (I) and a second holding valve module (II), wherein the first holding valve module (I) comprises a first control valve (1) and a first non-return valve (3), and the second holding valve module (II) comprises a second control valve (2) and a second non-return valve (4). The two-way control holding valve unit is provided with a first pilot control port (PX), a second pilot control port (PY), a first oil return port (T1), a first energy recovery oil inlet port (PR), and a second energy recovery oil inlet port (PH). The control end of the first control valve (1) is connected to the first pilot control port (PX), and the second control valve (PY) is connected to the first control port (PY). The control end of the first check valve (2) is connected to the second pilot control port (PY), the first oil return port (T1) is connected to the oil return ports of the first control valve (1) and the second control valve (2), the oil inlets of the first check valve (3) and the second check valve (4) are connected to the hydraulic system for energy recovery, the spring chamber and the oil inlet cavity of the first check valve (3) are connected through the first control valve (1), the spring chamber and the oil inlet cavity of the second check valve (4) are connected through the second control valve (2), the first energy recovery oil inlet port (PR) is connected to the oil inlet port of the first check valve (3), and the second energy recovery oil inlet port (PH) is connected to the oil inlet port of the second check valve (4); The main valve unit is provided with a first energy recovery oil outlet (P), a second energy recovery oil outlet (A), a second oil return port (T) and a control port (P1), and comprises a shuttle valve (5) and a five-position four-way reversing valve (6); the port a of the shuttle valve (5) is connected to the oil outlet of the first one-way valve (3), the port b is connected to the oil outlet of the second one-way valve (4), the port c is connected to the oil inlet and the control end d of the five-position four-way reversing valve (6); the first energy recovery oil outlet (P), the second energy recovery oil outlet (A) and the second oil return port (T) are connected to the oil outlet of the five-position four-way reversing valve (6), and the control port (P1) is connected to the control end e of the five-position four-way reversing valve (6).

2. The self-controlled energy recovery and reuse structure according to claim 1, characterized in that: The five-position four-way reversing valve (6) is further provided with a transition function structure on the basis of a conventional reversing valve.

3. The self-controlled energy recovery and reuse structure according to claim 1, characterized in that: A first damper (7) is installed in the oil passage between the c port of the shuttle valve (5) and the control end d of the five-position four-way reversing valve (6), and a second damper (8) is installed in the oil passage between the control port (P1) and the control end e of the five-position four-way reversing valve (6).

4. A hydraulic excavator, characterized in that: Equipped with a self-controlled energy recovery and reuse structure as described in any one of claims 1-3.

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