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

Abstract

The application relates to a self-control type energy recycling structure and a hydraulic excavator loaded with the structure, and aims to solve the technical problem of load increase of a conventional multi-way valve energy recycling, and the technical scheme is as follows: the self-control type energy recycling structure comprises a bidirectional control holding valve unit and a main valve unit; the bidirectional control holding valve unit comprises two holding valve modules, the holding valve module comprises a control valve and a one-way valve, is connected with a pilot control port, an oil return port and an energy recycling oil inlet port respectively, the main valve unit comprises a shuttle valve and a five-position four-way reversing valve, the oil inlets of the shuttle valve are connected with the oil outlets of the two one-way valves respectively, the oil outlets are connected with the oil inlets and control ends of the five-position four-way reversing valve, and are connected with the energy recycling oil outlets and the oil return ports of the main valve unit. The application integrates the modules in the valve body, feeds back the energy to be recycled through pressure feedback of the valve, returns the energy to the load input port through the energy recycling structure, and achieves the energy recycling effect.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of hydraulic systems of engineering machinery, and particularly relates to a self-control type energy recycling structure and a hydraulic excavator carrying the same. BACKGROUND

[0002] Nowadays, engineering machinery is widely applied, and in the working process of engineering machinery, there is a large amount of energy waste, which causes low energy utilization rate, high operation cost, and does not meet the trend of energy saving and environmental protection. The traditional engineering machinery lacks an efficient energy recycling mechanism, and needs to be improved.

[0003] In a hydraulic system, a conventional plate type multi-way valve needs to separately increase a load sensing element to realize energy recycling through external control, and the weight of the valve is also increased, which leads to high transportation cost, impact in the working process, influence on stable operation of the load, poor pressure maintaining effect, and leakage risk. SUMMARY

[0004] The application aims to solve the above problems, and provides a self-control type energy recycling structure and a hydraulic excavator carrying the same.

[0005] To solve the above technical problems, the application adopts the following technical scheme:

[0006] A self-control type energy recycling structure, comprising a double-direction control holding valve unit and a main valve unit.

[0007] The double-direction control holding valve unit comprises a first holding valve module I and a second holding valve module II, the first holding valve module I comprises a first control valve and a first check valve, the second holding valve module II comprises a second control valve and a second check valve, the double-direction 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 recycling oil inlet port PR and a second energy recycling oil inlet port PH, a control end of the first control valve is communicated with the first pilot control port PX, a control end of the second control valve is communicated with the second pilot control port PY, the first oil return port T1 is communicated with oil return ports of the first control valve and the second control valve, oil inlet ports of the first check valve and the second check valve are connected with a hydraulic system to be recycled, a spring cavity and an oil inlet port cavity of the first check valve are communicated through the first control valve, a spring cavity and an oil inlet port cavity of the second check valve are communicated through the second control valve, the first energy recycling oil inlet port PR is communicated with the oil inlet port of the first check valve, and the second energy recycling oil inlet port PH is communicated with the oil inlet port of the second check valve.

[0008] 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 and a five-position four-way directional valve; the a port of the shuttle valve is communicated with the oil outlet of the first one-way valve, the b port is communicated with the oil outlet of the second one-way valve, and the c port is communicated with the oil inlet and the control end d of the five-position four-way directional valve; the first energy recovery oil outlet P, the second energy recovery oil outlet A and the second oil return port T are communicated with the oil outlet of the five-position four-way directional valve; and the control port P1 is connected with the control end e of the five-position four-way directional valve.

[0009] Further, the five-position four-way directional valve is additionally provided with a transition function structure on the basis of a conventional directional valve.

[0010] Further, 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 directional 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 directional valve.

[0011] A hydraulic excavator is provided with a self-control type energy recovery and reuse structure.

[0012] Compared with the prior art, the hydraulic valve has the following beneficial effects:

[0013] 1. The valve body is provided with various unit modules, and the energy to be recovered is returned to the load input port through the energy recovery structure by pressure feedback of the valve, so that the energy recovery and reuse effect is achieved, the weight of the valve body is reduced, and the lightweight of the valve body is realized.

[0014] 2. The five-position four-way directional valve is additionally provided with a transition function on the basis of a conventional directional valve, so that the impact generated in the directional change process does not affect the load action, the action of the actuator is more stable, and the load movement is stable and free of impact.

[0015] 3. The pressure of the oil inlet of the one-way valve acts on the spring cavity of the one-way valve through the control valve, a reliable and stable seal is formed under the pressure of the spring cavity of the one-way valve, the purpose of zero leakage is achieved, the communication of the oil passage is blocked, and a reliable load holding function is formed. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is a principle diagram of the present application when there is no load (load holding function);

[0017] Figure 2 It is a principle diagram of energy recovery to the main oil passage when the arm of the hydraulic excavator is retracted and moves downward;

[0018] Figure 3 It is a principle diagram of energy recovery to other auxiliary actuators when the arm of the hydraulic excavator is retracted and moves downward;

[0019] Figure 4 Fig. 4 is a schematic diagram of the principle of the boom retraction and upward movement of the hydraulic excavator;

[0020] Figure 5 Fig. 5 is a schematic diagram of the principle of the boom swing and downward movement of the hydraulic excavator and the energy recovery to the main oil circuit;

[0021] Figure 6 Fig. 6 is a schematic diagram of the principle of the boom swing and downward movement of the hydraulic excavator and the energy recovery to other auxiliary actuators;

[0022] Figure 7 Fig. 7 is a schematic diagram of the principle of the boom swing and upward movement of the hydraulic excavator;

[0023] In the figure: I, first holding valve module; II, second holding valve module; 1, first control valve; 2, second control valve; 3, first check valve; 4, second check valve; 5, shuttle valve; 6, five-position four-way directional valve; 7, first damper; 8, second damper; PX, first pilot control port; PY, second pilot control port; T1, first return port; PR, first energy recovery inlet port; PH, second energy recovery inlet port; P, first energy recovery outlet port; A, second energy recovery outlet port; T, second return port; P1, control port. DETAILED DESCRIPTION

[0024] The application will be further described below in conjunction with the drawings and examples. EXAMPLE

[0025] The self-control type energy recovery and reuse structure comprises a bidirectional control holding valve unit and a main valve unit.

[0026] The bidirectional control holding valve unit comprises a first holding valve module I and a second holding valve module II, the first holding valve module I comprises a first control valve 1 and a first check valve 3, the second holding valve module II comprises a second control valve 2 and a second check valve 4, the bidirectional control holding valve unit is provided with a first pilot control port PX, a second pilot control port PY, a first return port T1, a first energy recovery inlet port PR and a second energy recovery inlet port PH, the control end of the first control valve 1 is communicated with the first pilot control port PX, the control end of the second control valve 2 is communicated with the second pilot control port PY, the first return port T1 is communicated with the return ports of the first control valve 1 and the second control valve 2, the inlet ports of the first check valve 3 and the second check valve 4 are connected with the hydraulic system to be recovered, the spring cavity and the inlet port cavity of the first check valve 3 are communicated through the first control valve 1, the spring cavity and the inlet port cavity of the second check valve 4 are communicated through the second control valve 2, the first energy recovery inlet port PR is communicated with the inlet port of the first check valve 3, and the second energy recovery inlet port PH is communicated with the inlet port of the second check valve 4.

[0027] The main valve unit is equipped with a first energy recovery outlet P, a second energy recovery outlet A, a second return outlet T, and a control port P1. It includes a shuttle valve 5 and a five-position four-way directional valve 6. Port a of the shuttle valve 5 is connected to the outlet of the first check valve 3, port b is connected to the outlet of the second check valve 4, and port c is connected to the inlet and control terminal d of the five-position four-way directional valve 6. A first damper 7 is installed in the oil passage between port c of the shuttle valve 5 and the control terminal d of the five-position four-way directional valve 6. The directional valve 6 is equipped with a transition function structure on the basis of a conventional directional valve, which avoids the impact of the impact generated during the switching process on the load action and makes the actuator action more stable. The first energy recovery oil outlet P, the second energy recovery oil outlet A, and the second return oil outlet T are connected to the oil outlet of the five-position four-way directional valve 6. The control port P1 is connected to the control end e of the five-position four-way directional 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 directional valve 6. Example

[0028] Taking the inward and outward swing of the stick in the excavator system as an example, the stick in the hydraulic excavator system is connected to the first energy recovery oil inlet PR in the rod-side chamber and the stick without rod chamber connected to the second energy recovery oil inlet PH in the stick system. 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 return oil outlet T. The control port P1 is connected to the pump outlet. The pressure at the control end d of the five-position four-way directional valve 6 is Pd, the pressure at the control end e is P1, and the pressure difference between the two ends is ΔP = Pd - P1.

[0029] Working principle of the invention:

[0030] When the system is in its initial state, the first pilot control port PX and the second pilot control port PY have no pilot pressure. The spring chamber and oil inlet of the first check valve 3 in the first holding valve module I are connected through the first control valve 1. The spring chamber and 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 rod chamber pressure oil of the stick goes through the first energy recovery inlet PR to the oil inlet of the first check valve 3, and the rodless chamber pressure oil of the stick goes through the second energy recovery inlet PH to the oil inlet of the second check valve 4.

[0031] like Figure 1 As shown, the pressure at the inlet of the check valve acts on the spring chamber of the check valve through the control valve, forming a reliable and stable seal under the pressure of the spring chamber, achieving zero leakage; at the same time, it blocks the connection of the oil circuit, forming a reliable load holding function.

[0032] like Figure 2As shown, when the stick retracts and moves downward, the first pilot control port PX is supplied with pressurized oil, the first control valve 1 is in the left position, the spring chamber of the first check valve 3 is connected to the first return port T1, the first check valve 3 is open, the a port of the shuttle valve 5 is connected to the c port, the pressurized oil in the stick's rod chamber enters the inlet of the first check valve 3 through the first energy recovery inlet PR, enters the shuttle valve 5 through the outlet of the first check valve 3, and enters the inlet of the five-position four-way directional 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 directional valve 6 is ΔP1, the outlet of the five-position four-way directional valve 6 is connected to the first energy recovery outlet P, and returns to the main oil circuit of the system.

[0033] like Figure 3 As shown, when the pressure difference ΔP1 drops to ΔP2, the oil outlet of the five-position four-way directional valve 6 is connected to the second energy recovery oil outlet A, and the energy enters other auxiliary actuators to drive the other auxiliary actuators to act or accelerate the action speed of the other auxiliary actuators.

[0034] like Figure 4 As shown, when the stick retracts and moves upward, the first pilot control port PX is supplied with pressurized oil, the first control valve 1 is in the left position, the spring chamber of the first check valve 3 is connected to the first return port T1, the first check valve 3 is open, the a port of the shuttle valve 5 is connected to the c port, the pressurized oil in the stick chamber enters the inlet of the first check valve 3 through the first energy recovery inlet PR, enters the shuttle valve 5 from the outlet of the first check valve 3, and enters the inlet of the five-position four-way directional 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 directional valve 6 drops to ΔP3, the outlet of the five-position four-way directional valve 6 is connected to the second return port T, and returns to the oil tank.

[0035] like Figure 5 As shown, when the boom swings outward and moves downward, the second pilot control port PY is supplied with pressure oil, the second control valve 2 is in the left position, the spring chamber of the second check valve 4 is connected to the first return port T1, the second check valve 4 is open, the b port of the shuttle valve 5 is connected to the c port, the pressure oil in the rodless chamber of the boom enters the inlet of the second check valve 4 through the second energy recovery inlet PH, enters the shuttle valve 5 from the outlet of the second check valve 4, and enters the inlet of the five-position four-way directional 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 directional valve 6 is ΔP1, the outlet of the five-position four-way directional valve 6 is connected to the first energy recovery outlet P, and returns to the main oil circuit of the system.

[0036] like Figure 6 As shown, when the pressure difference drops to ΔP2, the oil outlet of the five-position four-way directional valve 6 is connected to the second energy recovery oil outlet A, and the energy enters other auxiliary actuators to drive the other auxiliary actuators to act or accelerate the action speed of the other auxiliary actuators.

[0037] like Figure 7As shown, when the stick swings outward and moves upward, the second pilot control port PY is supplied with pressure oil, the second control valve 2 is in the left position, the spring chamber of the second check valve 4 is connected to the first return port T1, the second check valve 4 is open, the b port of the shuttle valve 5 is connected to the c port, the pressure oil in the rodless chamber of the stick enters the inlet of the second check valve 4 through the second energy recovery inlet PH, enters the shuttle valve 5 from the outlet of the second check valve 4, and enters the inlet of the five-position four-way directional 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 directional valve 6 drops to ΔP3, the outlet of the five-position four-way directional valve 6 is connected to the second return port T, and returns to the oil tank.

Claims

1. A self-controlled energy recovery and reuse structure, characterized in that, This includes a bidirectional control holding valve unit and a main valve unit; The bidirectional 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 check valve (3). The second holding valve module (II) includes a second control valve (2) and a second check valve (4). The bidirectional control holding valve unit is provided with a first pilot control port (P). X ), second pilot control port (P) Y First return oil port (T1), first energy recovery oil inlet (P) R ) and the second energy recovery oil inlet (P H The control terminal of the first control valve (1) is connected to the first pilot control port (P). X The control terminal of the second control valve (2) is connected to the second pilot control port (P). Y The first return port (T1) is connected to the return ports of the first control valve (1) and the second control valve (2). The 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 inlet chamber of the first check valve (3) are connected through the first control valve (1). The spring chamber and the inlet chamber of the second check valve (4) are connected through the second control valve (2). The first energy recovery inlet (P) R The oil inlet of the first one-way valve (3) is connected to the oil inlet of the second energy recovery oil inlet (P). H ) connects to the oil inlet of the second check valve (4); The main valve unit is provided with a first energy recovery outlet (P), a second energy recovery outlet (A), a second return port (T), and a control port (P1), including a shuttle valve (5) and a five-position four-way directional valve (6). Port a of the shuttle valve (5) is connected to the outlet of the first check valve (3), port b is connected to the outlet of the second check valve (4), and port c is connected to the inlet of the five-position four-way directional valve (6) and the control terminal d. The first energy recovery outlet (P), the second energy recovery outlet (A), the second return port (T), and the control port (P1) are connected to the outlet of the first check valve (3), the second return port (A), and the control port (P1). The oil port (A) and the second return oil port (T) are connected to the oil outlet of the five-position four-way directional valve (6). The control port (P1) is connected to the control end e of the five-position four-way directional valve (6) and the oil outlet of the pump. 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 directional valve (6). 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 directional valve (6).

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

3. A hydraulic excavator, characterized in that, The device is equipped with a self-controlled energy recovery and reuse structure as described in any one of claims 1-2.

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