CN105421509B - A kind of hybrid excavator movable arm potential energy retracting device and hybrid excavator - Google Patents

Abstract

The invention relates to the technical field of excavators, in particular to a hybrid excavator arm potential energy recovery device and a hybrid excavator. The device includes a boom cylinder, a hydraulic pump/motor assembly (hydraulic pump or motor assembly) and a boom cylinder control valve, and the boom cylinder control valve is provided with A port, B port, P port, T port and D port; When the boom cylinder control valve is lifted, port A is connected to port P, port B is connected to port D, and port D is connected to the oil tank; when the boom of the excavator is lowered, it is connected to Port A is connected to port T, and port B is connected to port P; and the large chamber of the boom cylinder is connected to port A; the small chamber of the boom cylinder is connected to port B; the oil outlet of the hydraulic pump/motor assembly is connected to port P The energy recovery and reuse oil circuit is connected to the T port, which is used to maintain communication between the large chamber of the boom cylinder and the oil inlet of the hydraulic pump/motor assembly when the excavator arm is lowered, so as to realize the connection of the excavator Recycling of boom potential energy.

Description

Hybrid excavator arm potential energy recovery device and hybrid excavator

technical field

The invention relates to the technical field of excavators, in particular to a hybrid excavator arm potential energy recovery device and a hybrid excavator.

Background technique

Generally, when the boom of the excavator is lowered, oil enters the small cavity of the boom cylinder and returns oil to the large cavity. Usually, the return oil of the large cavity directly enters the oil return circuit through the internal oil channel of the control valve of the boom cylinder; Part of the return oil directly enters the oil return circuit through the oil passage inside the control valve of the boom cylinder. However, due to the existence of the potential energy of the boom when the boom is lowered, the oil return from the large cavity has a lot of energy. If the oil directly enters the oil return circuit in the above way, it is undoubtedly a huge waste.

Contents of the invention

(1) Technical problems to be solved

The technical problem to be solved by the invention is the waste of potential energy caused by the frequent take-off and landing of the existing excavator arm.

(2) Technical solution

In order to solve the above technical problems, the present invention provides a hybrid excavator arm potential energy recovery device, which includes:

Boom oil cylinder control valve, the boom oil cylinder control valve is provided with A port, B port, P port, T port and D port; the boom oil cylinder control valve makes A Port is connected to port P, port B is connected to port D, and port D is connected to the fuel tank; when the boom cylinder control valve is lowered, port A is connected to port T, and port B is connected to port B. The port is connected to the P port;

Boom oil cylinder, the large chamber of the boom oil cylinder is connected to port A; the small chamber of the boom oil cylinder is connected to port B;

A hydraulic pump/motor assembly, the oil outlet of the hydraulic pump/motor assembly is connected to the P port, and its oil inlet is connected to the fuel tank through a one-way control valve, between the oil inlet and the one-way control valve An energy recovery and reuse oil circuit is connected; the energy recovery and reuse oil circuit is connected to the T port, and is used to make the large chamber of the boom cylinder and the inlet of the hydraulic pump/motor assembly when the excavator arm descends. The ports remain connected.

Wherein, the boom cylinder control valve is connected with a first signal control unit and a second signal control unit;

When the boom of the excavator is lifted, the first signal control unit controls the control valve of the boom cylinder to switch to the left position, so that port A is connected to port P, and port B is connected to port D;

When the boom of the excavator is lowered, the second signal control unit controls the control valve of the boom cylinder to switch to the right position, so that the A port is connected to the T port, and the B port is connected to the P port.

Wherein, the energy recovery and reuse oil circuit is provided with a pressure control valve for diversion, and the pressure control valve is connected with the oil tank.

Wherein, the pressure control valve is a relief valve or a safety valve, and the relief pressure of the pressure control valve is set at 5-15 MPa.

Wherein, the oil outlet of the hydraulic pump/motor assembly is also connected with a load mechanism, and the load mechanism includes one or more of an arm cylinder, a bucket cylinder, a swing motor or a traveling motor.

Wherein, the stick cylinder is connected to the oil outlet of the hydraulic pump/motor assembly through a stick cylinder control valve, and the stick cylinder control valve is respectively connected with a third signal control unit and a fourth signal control unit;

When the stick cylinder needs to be extended, the third signal control unit controls the control valve of the stick cylinder to switch to the right position, so that the oil flowing out from the oil outlet enters the large cavity of the stick cylinder ;

When the stick cylinder needs to retract, the fourth signal control unit controls the stick cylinder control valve to switch to the left position, so that the oil flowing out from the oil outlet enters the small chamber of the stick cylinder.

Wherein, the bucket oil cylinder is connected to the oil outlet of the hydraulic pump/motor assembly through a bucket oil cylinder control valve, and the bucket oil cylinder control valve is respectively connected with a fifth signal control unit and a sixth signal control unit;

When the bucket oil cylinder needs to be extended, the fifth signal control unit controls the bucket oil cylinder control valve to switch to the right position, so that the oil flowing out from the oil outlet enters the large cavity of the bucket oil cylinder ;

When the bucket oil cylinder needs to retract, the sixth signal control unit controls the bucket oil cylinder control valve to switch to the left position, so that the oil flowing out from the oil outlet enters the small chamber of the bucket oil cylinder.

Wherein, the boom oil cylinder is one or more of single oil cylinder, double oil cylinder and multiple oil cylinders.

Wherein, an accumulator is connected to the energy recovery and reuse oil circuit.

The present invention also provides a hybrid excavator, which includes the hybrid excavator arm potential energy recovery device.

(3) Beneficial effects

The above-mentioned technical solution of the present invention has the following beneficial effects: the present invention aims at the shortcoming of potential energy waste of the existing excavator arm during frequent take-off and landing, and provides a new type of potential energy recovery device for the arm of the hybrid excavator. The potential energy generated by the lowering of the mobile arm is recovered and reused to achieve the effect of improving the energy utilization rate of the excavator and saving energy consumption.

Description of drawings

1 is a schematic structural view of a potential energy recovery device for a hybrid excavator arm according to an embodiment of the present invention;

Fig. 2 is a schematic structural diagram of a potential energy recovery device for a hybrid excavator arm according to Embodiment 2 of the present invention.

Among them, 1: boom cylinder; 1a: small cavity; 1b: large cavity; 2: stick cylinder; 3: bucket cylinder; 4: boom cylinder control valve; 5: stick cylinder control valve; 6: bucket Oil cylinder control valve; 7a: first signal control unit; 7b: second signal control unit; 8a: third signal control unit; 8b: fourth signal control unit; 9a: fifth signal control unit; 9b: sixth signal control unit Unit; 10: power component; 11: hydraulic pump/motor assembly; 12: one-way control valve; 13: pressure control valve; 14: energy recovery and reuse oil circuit; 15: excavator arm; 16: accumulator.

detailed description

Embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but should not be used to limit the scope of the present invention.

In the description of the present invention, it should be noted that unless otherwise specified, the meaning of "plurality" is two or more; the terms "upper", "lower", "left", "right", "inner ", "outside", "front end", "rear end", "head", "tail", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and Simplified descriptions, rather than indicating or implying that the device or element referred to must have a particular orientation, be constructed and operate in a particular orientation, and thus should not be construed as limiting the invention. In addition, the terms "first", "second", "third", etc. are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

In the description of the present invention, it should also be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be interpreted in a broad sense, for example, it can be a fixed connection or a flexible connection. Detachable connection, or integral connection; it can be mechanical connection or electrical connection; it can be direct connection or indirect connection through an intermediary. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

Embodiment one

As shown in Figure 1, this embodiment provides a hybrid excavator arm potential energy recovery device, which includes: boom cylinder 1, hydraulic pump/motor assembly 11 (hydraulic pump or motor assembly) and boom cylinder control valve 4 . A port, B port, P port, T port and D port are arranged on the boom cylinder control valve 4; when the boom cylinder control valve 4 is lifted, the A port and the P port are connected. , port B is connected to port D, and port D is connected to the oil tank; when the boom 15 of the excavator is lowered, the control valve 4 of the boom cylinder connects port A to port T, and port B to port P; The large chamber 1b of the arm cylinder 1 is connected to port A; the small chamber 1a of the boom cylinder 1 is connected to port B; the oil outlet of the hydraulic pump/motor assembly 11 is connected to port P, and its oil inlet passes through a one-way control valve 12 is connected to the oil tank, and an energy recovery and reuse oil circuit 14 is connected between the oil inlet and the one-way control valve 12; the energy recovery and reuse oil circuit 14 is connected to the T port, which is used for when the excavator arm 15 descends Keep the large cavity 1b of the boom cylinder 1 in communication with the oil inlet of the hydraulic pump/motor assembly 11, so as to realize the recovery and utilization of the potential energy of the excavator boom 15.

It is worth noting that the potential energy recovery device is not limited to the potential energy recovery of the excavator arm 15, and is also applicable to other lifting or lowering actuators.

Specifically, a first signal control unit 7a and a second signal control unit 7b are connected to the control valve 4 of the boom cylinder; wherein, the first signal control unit 7a and the second signal control unit 7b are used to apply control signals to realize automatic control .

When the excavator boom 15 is lifted, the first signal control unit 7a controls the boom cylinder control valve 4 to switch to the left position, so that the A port is connected to the P port, and the B port is connected to the D port; the specific execution process is as follows : The first signal control unit 7a applies the control signal of the lifting control valve of the boom cylinder 1, so that the control valve 4 of the boom cylinder is switched to the left position, and at the same time, the oil inlet of the hydraulic pump/motor assembly 11 is fed from the oil tank through the one-way control valve 12 Oil suction, the oil flows through the P port of the boom cylinder control valve 4 to the A port, and thus enters the large chamber 1b of the boom cylinder 1 . The oil in the small chamber 1a of the boom cylinder 1 returns to the fuel tank after being connected through the B port and the D port of the boom cylinder control valve 4 .

When the excavator boom 15 is lowered, the second signal control unit 7b controls the boom cylinder control valve 4 to switch to the right position, so that the A port is connected to the T port, and the B port is connected to the P port. The specific execution process is: the second signal control unit 7b applies the control signal of the lowering control valve of the boom cylinder 1, so that the control valve 4 of the boom cylinder is switched to the right position, and the oil in the large cavity 1b of the boom cylinder 1 is controlled by the boom cylinder. After the port A of the valve 4 is connected to the port T, it enters the energy recovery and reuse oil circuit 14 . Further, the energy recovery and reuse oil passage 14 is also provided with a pressure control valve 13 for diversion, and the pressure control valve 13 is connected with the oil tank. After the return oil enters the energy recovery and reuse oil circuit 14, there are check valves and relief valves or safety valves in front of the oil circuit (wherein, the relief pressure set by the relief valve or safety valve can usually be considered as 7-15MPa), These two valves prevent return oil from going directly back to tank, allowing oil to enter the inlet port of the hydraulic pump or motor assembly. Then, the oil flows through the P port of the boom cylinder control valve 4 to the B port, and enters the small cavity 1a of the boom cylinder 1 to realize the recovery and reuse of the potential energy of the boom.

It should be understood that the boom cylinder control valve 4 disclosed above can have various forms, and a combined valve with other functions or an independent form can be used to meet the boom cylinder 1 large cavity 1b when the boom or the actuator is lowered. The function of communicating with the oil inlet of the hydraulic pump realizes the function of communicating with the large chamber 1b of the boom cylinder 1 and the oil tank when lifting.

In addition, the form of the pressure control valve 13 is not limited, it may be a relief valve or a safety valve, and the relief pressure of the pressure control valve 13 is set at 5-15 MPa. Certainly, it may specifically be a valve with a similar function such as an on-off valve, a proportional valve, etc., for removing excess flow.

In addition, the oil outlet of the hydraulic pump/motor assembly 11 is also connected to a load mechanism, and the load mechanism includes one or more of the stick cylinder 2, bucket cylinder 3, swing motor or traveling motor.

Wherein, the stick cylinder 2 is connected to the oil outlet of the hydraulic pump/motor assembly 11 through the stick cylinder control valve 5, and the stick cylinder control valve 5 is respectively connected with a third signal control unit 8a and a fourth signal control unit 8b; When the stick cylinder 2 needs to extend, the third signal control unit 8a controls the stick cylinder control valve 5 to switch to the right position, so that the oil flowing out from the oil outlet enters the large cavity 1b of the stick cylinder 2; when the stick When the oil cylinder 2 needs to retract, the fourth signal control unit 8b controls the stick cylinder control valve 5 to switch to the left position, so that the oil flowing out from the oil outlet enters the small chamber 1a of the stick cylinder 2 .

Wherein, the bucket oil cylinder 3 is connected to the oil outlet of the hydraulic pump/motor assembly 11 through the bucket oil cylinder control valve 6, and the bucket oil cylinder control valve 6 is respectively connected with the fifth signal control unit 9a and the sixth signal control unit 9b; When the bucket cylinder 3 needs to be extended, the fifth signal control unit 9a controls the bucket cylinder control valve 6 to switch to the right position, so that the oil flowing out from the oil outlet enters the large cavity 1b of the bucket cylinder 3; when the bucket When the oil cylinder 3 needs to retract, the sixth signal control unit 9b controls the bucket oil cylinder control valve 6 to switch to the left position, so that the oil flowing out from the oil outlet enters the small cavity 1a of the bucket oil cylinder 3 .

In addition, other load element control valves can also be provided correspondingly for other load mechanisms, and the control principles thereof are the same or similar to those described above.

Preferably, the boom oil cylinder 1 is one or more of single oil cylinder, double oil cylinder and multi-oil cylinder, and the combinations are flexible and diverse.

Further, the power input end of the hydraulic pump/motor assembly 11 is connected to a power element 10 such as an engine or an electric motor, and may be a single pump, a combined pump, or a motor with a pump function.

To sum up, this embodiment designs a new hybrid excavator arm potential energy recovery device, which directly leads the high-pressure oil return from the large chamber 1b of the boom cylinder 1 to the oil inlet of the hydraulic pump or motor to increase the oil inlet pressure. , effectively utilize the potential energy when the boom or the actuator is lowered, reduce the required power (or torque) of the hydraulic pump or motor, reduce the energy consumption of the power source, and achieve the purpose of energy saving.

Moreover, the structure of the device is simple, and compared with the traditional principle, there are not many additional parts, and it can be adapted to the selection of different models. At the same time, it can also achieve a good energy-saving effect, and a relatively small-power prime mover can be selected, thereby reducing equipment costs.

Embodiment two

As shown in Figure 2, the technical content of the second embodiment that is the same as that of the first embodiment will not be described repeatedly, and the content disclosed in the first embodiment also belongs to the content disclosed in the second embodiment. The difference between the second embodiment and the first embodiment is: An accumulator 16 is also connected to the energy recovery and reuse oil passage 14 . That is to say, an accumulator 16 can be arranged according to FIG. 2 on the oil path between the control valve 4 of the boom cylinder and the oil inlet of the hydraulic pump or motor assembly, so as to increase the recovery of the potential energy of the boom. The accumulator 16 is an energy storage device in a hydropneumatic system. It converts the energy in the system into compression energy or potential energy at an appropriate time and stores it. When the system needs it, it converts the compression energy or potential energy into hydraulic or pneumatic energy and releases it to replenish the system.

Embodiment Three

According to the contents disclosed in the first and second embodiments above, the third embodiment provides a hybrid excavator, including the hybrid excavator arm potential energy recovery device disclosed above, which has the same technical effect. Compared with traditional excavator hydraulic oil circuits, the required power (or torque) of hydraulic pumps or motors can be reduced, that is, the power output of power components 10 such as engines or electric motors can be reduced, and their energy consumption can be reduced, so as to achieve the purpose of energy saving.

The embodiments of the present invention have been presented for purposes of illustration and description, but are not intended to be exhaustive or to limit the invention to the form disclosed. Many modifications and changes will be apparent to those of ordinary skill in the art. The embodiment was chosen and described in order to better explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention and design various embodiments with various modifications as are suited to the particular use.

Claims (10)

1. A hybrid excavator arm potential energy recovery device, characterized in that it comprises: Boom oil cylinder control valve, the boom oil cylinder control valve is provided with A port, B port, P port, T port and D port; the boom oil cylinder control valve makes A Port is connected to port P, port B is connected to port D, and port D is connected to the fuel tank; when the boom cylinder control valve is lowered, port A is connected to port T, and port B is connected to port B. The port is connected to the P port; Boom oil cylinder, the large chamber of the boom oil cylinder is connected to port A; the small chamber of the boom oil cylinder is connected to port B; A hydraulic pump/motor assembly, the oil outlet of the hydraulic pump/motor assembly is connected to the P port, and its oil inlet is connected to the fuel tank through a one-way control valve, between the oil inlet and the one-way control valve An energy recovery and reuse oil circuit is connected; the energy recovery and reuse oil circuit is connected to the T port, and is used to make the large chamber of the boom cylinder and the inlet of the hydraulic pump/motor assembly when the excavator arm descends. The ports remain connected. 2. The hybrid excavator boom potential energy recovery device according to claim 1, characterized in that the boom cylinder control valve is connected with a first signal control unit and a second signal control unit; When the boom of the excavator is lifted, the first signal control unit controls the control valve of the boom cylinder to switch to the left position, so that port A is connected to port P, and port B is connected to port D; When the boom of the excavator is lowered, the second signal control unit controls the control valve of the boom cylinder to switch to the right position, so that the A port is connected to the T port, and the B port is connected to the P port. 3. The hybrid excavator boom potential energy recovery device according to claim 1, characterized in that, the energy recovery and reuse oil circuit is provided with a pressure control valve for diversion, and the pressure control valve is connected to the oil tank. 4. The hybrid excavator arm potential energy recovery device according to claim 3, wherein the pressure control valve is a relief valve or a safety valve, and the relief pressure of the pressure control valve is set to 5-15MPa . 5. The hybrid excavator arm potential energy recovery device according to claim 1, characterized in that, the oil outlet of the hydraulic pump/motor assembly is also connected to a load mechanism, and the load mechanism includes an arm cylinder, a shovel One or more of bucket oil cylinder, swing motor or travel motor. 6. The hybrid excavator arm potential energy recovery device according to claim 5, characterized in that, the stick cylinder is connected to the oil outlet of the hydraulic pump/motor assembly through a stick cylinder control valve, and the The stick cylinder control valve is respectively connected with a third signal control unit and a fourth signal control unit; When the stick cylinder needs to be extended, the third signal control unit controls the control valve of the stick cylinder to switch to the right position, so that the oil flowing out from the oil outlet enters the large cavity of the stick cylinder ; When the stick cylinder needs to retract, the fourth signal control unit controls the stick cylinder control valve to switch to the left position, so that the oil flowing out from the oil outlet enters the small chamber of the stick cylinder. 7. The hybrid excavator arm potential energy recovery device according to claim 5, characterized in that, the bucket cylinder is connected to the oil outlet of the hydraulic pump/motor assembly through a bucket cylinder control valve, and the The bucket oil cylinder control valve is respectively connected with the fifth signal control unit and the sixth signal control unit; When the bucket oil cylinder needs to be extended, the fifth signal control unit controls the bucket oil cylinder control valve to switch to the right position, so that the oil flowing out from the oil outlet enters the large cavity of the bucket oil cylinder ; When the bucket oil cylinder needs to retract, the sixth signal control unit controls the bucket oil cylinder control valve to switch to the left position, so that the oil flowing out from the oil outlet enters the small chamber of the bucket oil cylinder. 8 . The hybrid excavator boom potential energy recovery device according to claim 1 , wherein the boom cylinder is one of single cylinder, double cylinder and multiple cylinders. 9 . The hybrid excavator arm potential energy recovery device according to claim 1 , wherein an accumulator is connected to the energy recovery and reuse oil circuit. 10. A hybrid excavator, characterized by comprising the hybrid excavator arm potential energy recovery device according to any one of claims 1-9.