CN105926696B - A kind of excavator swing arm potential energy classification recovery and release device and its method - Google Patents

Abstract

The invention discloses a device and method for recovering and releasing the potential energy of an excavator arm in stages. Shuttle valve, boom lock main valve, two release valves, boom lock pilot valve, two accumulators, two recovery valve boom cylinders, four check valves, controller, safety valve, shut-off valve, high pressure relief valve, back pressure valve, auxiliary motor. Through the collection of pressure signals at each point, it is judged whether the boom is loaded, so that the high-pressure accumulator is used to recover the boom when it is heavy-loaded, and the low-pressure accumulator is used to recover when it is no-load, so that the boom under different working conditions can be recovered. The potential energy is fully recovered while avoiding the disadvantages of existing methods such as the use of proportional reversing valves, throttle valves, and speed control valves, or the use of single-type accumulators with poor handling characteristics, and the disadvantages of not being able to fully recover power drop potential energy, etc. It has the characteristics of high fuel saving rate, good maneuverability, and does not affect the working efficiency of the original machine.

Description

An excavator arm potential energy classification recovery and release device and method thereof

technical field

The invention relates to an excavator, in particular to a hydraulic system for recovering and releasing potential energy of an arm of an oil-liquid hybrid excavator, and belongs to the technical field of engineering machinery.

Background technique

The boom of the hydraulic excavator has the characteristics of frequent movement and large mass. During the lowering of the boom, a large amount of oil is wasted through the orifice of the main control valve, which not only causes energy loss but also reduces the life of the system due to the increase of oil temperature. By recovering and utilizing the potential energy of the boom, a secondary power source is formed, and a hybrid system is formed with the engine, which can significantly improve the fuel saving rate of the excavator.

At present, the recovery and utilization of the potential energy of the boom is mainly concentrated in two aspects: one is to recover through the motor, and convert it into electric energy and store it in the battery or super capacitor, and then release it through the motor. This type of system is called a hybrid power system; The fuel is recovered through the hydraulic accumulator and released through the auxiliary motor or directly into the main system through the switching valve. This type of system is called an oil-hydraulic hybrid system. At present, the recovery of the potential energy of the boom is mainly concentrated in the oil-electric hybrid system, but this type of system has many energy conversion links, the conversion efficiency is low, and the system is expensive; so at present, some domestic units have recovered the potential energy of the boom from the oil-hydraulic hybrid system. However, the current relevant research mainly includes:

(1) Recovery through the hydraulic control reversing valve: Due to the harsh working environment of the excavator, large load changes, and high requirements for energy recovery, it is impossible to judge whether the system is loaded by simply using the hydraulic control reversing valve to determine whether to perform energy recovery , and if the energy recovery system is turned on at the time of load, the boom will drop rapidly due to the low pressure of the accumulator, resulting in a stall phenomenon.

(2) Recovery through proportional directional valve, proportional throttle valve, and speed regulating valve: the introduction of proportional directional valve, proportional throttle valve, and speed regulating valve will bring certain throttling loss, reduce energy recovery rate, and The proportional signal needs to be matched with the excavator's working conditions, pose, etc., the control performance is complicated, and the portability is poor.

Moreover, the existing research cannot solve the problem of energy recovery when the boom is lowered when the excavator is loaded. Once the boom is lowered when the excavator is loaded (for example, during the loading and unloading process, the boom will have a small displacement to adjust the optimal unloading method). Soil posture), because the bucket is filled with materials, the load increases a lot, and because the moment arm is longer, the pressure in the rodless cavity of the boom cylinder increases by about 6MPa compared with the empty load (taking a medium-tonnage excavator as an example ), at this time, if it is still recovered through the original accumulator, or the pressure of the accumulator is too low, the boom will drop rapidly when the energy is recovered. At this time, the speed cannot be controlled, and the forced braking will cause the whole vehicle to shake violently , the risk is high; and if the working pressure of the accumulator is increased to make the pressure of the accumulator equal to the pressure of the large chamber of the boom when it is loaded, it can solve the phenomenon of the boom falling quickly when it is lowered with a load, but it will Due to the high pressure of the accumulator, and because the descending speed becomes slower, the power of the main pump increases, which also offsets the energy recovery effect to a certain extent. And by judging the pressure sensor to judge whether it is loaded, it is not feasible to recover when it is loaded, and it is not feasible to recover when it is controlled, because if the reversing valve is opened with a large opening, the pressure in the large cavity of the boom will drop rapidly. The pressure in the large cavity of the boom is about the same when it is loaded and not loaded, and it cannot be distinguished whether it is loaded or not, and if the energy is not recovered when it is loaded, the energy recovery rate will be reduced; and as mentioned above, using balance valves or speed control valves The flow element is used to improve the rapid drop phenomenon of the boom when descending with load, which will bring a certain pressure loss and reduce the energy recovery rate.

Contents of the invention

In order to solve the above problems, the present invention provides an excavator arm potential energy classification recovery and release device and method, which can perform energy recovery and utilization under various working conditions such as no-load and heavy-load of the excavator, and solve the problem of adding energy recovery. Some other problems brought about by the system afterward.

The technical solution adopted to achieve the above purpose: a device for recovering and releasing the potential energy of excavator arm in stages, including: pilot pump, main pump, operating handle, first pressure sensor, boom locking control valve, hydraulic control reversing valve, first shuttle valve, boom lock valve, low pressure release valve, low pressure accumulator, second pressure sensor, low pressure recovery valve, third pressure sensor, fourth pressure sensor, boom cylinder, first check valve , the fifth pressure sensor, controller, second one-way valve, high-pressure recovery valve, high-pressure accumulator, high-pressure release valve, third one-way valve, fourth one-way valve, back pressure valve, auxiliary motor, engine;

The engine is connected with the main pump, the pilot pump and the auxiliary motor in turn, the oil inlet of the main pump is connected with the oil tank, and the oil outlet is connected with the oil inlet P of the hydraulic control reversing valve; the oil return port T of the hydraulic control reversing valve is connected with the The oil tank is connected, the oil outlet B is connected with the rod chamber of the boom cylinder, the oil outlet A is connected with the oil inlet of the boom lock valve; the oil outlet of the boom lock valve is connected with the rodless chamber of the boom cylinder connected; the rodless cavity of the boom cylinder is respectively connected with the oil inlet of the first one-way valve, the oil inlet of the second one-way valve, the control oil port of the high-pressure recovery valve, and the control oil port of the low-pressure recovery valve;

The oil outlet of the first check valve is connected with the oil inlet of the low-pressure recovery valve, the oil return port of the low-pressure recovery valve is connected with the oil tank, and the oil outlet of the low-pressure recovery valve is respectively connected with the oil inlet of the low-pressure accumulator and the low-pressure release valve. The oil outlet of the low-pressure relief valve is connected with an oil inlet of the first shuttle valve;

The oil outlet of the second one-way valve is connected with the oil inlet of the high-pressure recovery valve; The oil outlet of the high pressure relief valve is connected with the other oil inlet of the first shuttle valve;

The oil outlet of the first shuttle valve is respectively connected with the oil outlet of the fourth one-way valve and the oil inlet of the auxiliary motor; the oil inlet of the fourth one-way valve is respectively connected with the oil outlet of the third one-way valve, the auxiliary motor The oil outlet of the motor is connected to the oil inlet of the back pressure valve, the oil outlet of the back pressure valve is connected to the oil tank, and the oil inlet of the third one-way valve is connected to the oil tank;

The oil inlet of the pilot pump is connected to the fuel tank, and the oil outlet is connected to the oil inlet P of the operating handle to provide hydraulic control force to the operating handle. The operating handle is used to control the opening direction of the hydraulic control reversing valve and the displacement of the opening spool. The oil outlet A of the handle is connected to the control port XA of the hydraulic control reversing valve, and the oil outlet B is respectively connected to the control port XB of the hydraulic control reversing valve and the oil inlet of the boom locking control valve; the boom locking control The oil return port of the valve is connected to the oil tank, and the oil outlet is connected to the control oil port of the boom lock valve;

The first pressure sensor is used to measure the pressure of the oil outlet B of the operating handle, the second pressure sensor is used to measure the pressure of the low-pressure accumulator, the third pressure sensor is used to measure the pressure of the rod chamber of the boom cylinder, and the fourth pressure sensor It is used to measure the pressure of the rodless chamber of the boom cylinder, and the fifth pressure sensor is used to measure the pressure of the high-pressure accumulator;

All pressure sensor signals are connected to the input of the controller, and the switches of the low-pressure recovery valve, high-pressure recovery valve, low-pressure release valve, high-pressure release valve and the displacement of the auxiliary motor are controlled according to the program in the controller.

Further, a potential energy classification recovery and release device for an excavator arm also includes a second shuttle valve, a safety valve, and a stop valve; one oil inlet of the second shuttle valve is connected to a low-pressure accumulator, and the other The oil inlet is connected with the high-pressure accumulator, and the oil outlet is respectively connected with the oil inlet of the safety valve and the oil inlet of the shut-off valve, the oil outlet of the safety valve is connected with the fuel tank, and the oil outlet of the shut-off valve is connected with the fuel tank.

Further, the high-pressure recovery valve and the low-pressure recovery valve are electromagnetic reversing valves or hydraulic control reversing valves, and the control methods of these two valves are the same.

Furthermore, the optimal solution for the high-pressure recovery valve and the low-pressure recovery valve is a threaded cartridge valve as the main valve, and a solenoid valve as the pilot valve.

Further, the high-pressure release valve and the low-pressure release valve are two-position two-way electromagnetic switch valves.

Further, the boom locking control valve is a two-position three-way electromagnetic switch valve.

Further, the cut-off valve is a manual on-off valve or an electromagnetic on-off valve.

The present invention also provides a method for grading recovery of potential energy of excavator arm and release device:

Energy recovery switching method: When the power supply of the controller is cut off, all the solenoid valves are powered off, and the displacement of the auxiliary motor is also equal. At this time, the boom locking control valve is in the spring position, and the outlet pressure of the pilot pump is locked through the boom. The control valve reaches the control oil port of the boom lock valve, the boom lock valve opens, and the low-pressure recovery valve and high-pressure recovery valve close. Control the reversing valve, and then return to the fuel tank. At this time, the system is the same as that of the ordinary excavator system; Switch command and auxiliary motor displacement command, at this time the system works in the energy recovery state, which can make the excavator work normally with the original system when the energy recovery system fails;

No-load energy recovery method: When the excavator in the original system descends without load, the oil in the large chamber of the boom cylinder returns to the oil through the hydraulic control reversing valve. Due to the throttle effect of the hydraulic control reversing valve spool, the boom cylinder The pressure in the large cavity is maintained at about 12MPa. If the controller power supply is powered on, the system works in the energy recovery state. The fourth pressure sensor detects that the pressure in the large cavity of the boom cylinder is below 16MPa and the first pressure sensor detects that the joystick controls the brake. When the boom is lowered and the pressure difference between the fourth pressure sensor and the second pressure sensor is less than 2MPa, the controller controls the boom lock control valve to be energized, the low-pressure recovery valve to be energized, the high-pressure recovery valve to be de-energized, and the boom lock valve to The control oil port is connected to the oil tank. At this time, the boom lock valve is closed, and the high-pressure recovery valve is also closed. The oil in the large cavity of the boom cylinder enters the low-pressure accumulator from the low-pressure recovery valve. , the moment the low-pressure recovery valve opens, the boom drops instantly, the minimum working pressure set by the low-pressure accumulator is 11MPa, and when the pressure difference between the fourth pressure sensor and the second pressure sensor is greater than 2MPa, the low-pressure recovery valve does not open , the maximum working pressure of the low-pressure accumulator is set by the safety valve, and its nominal volume meets the oil that can recover 60% of the total stroke of the boom cylinder;

On-load energy recovery method: When the excavator in the original system is under load, although the quality of the excavated materials is much smaller than that of the entire boom, bucket, and stick, due to the increase in torque, the large cavity of the boom cylinder The pressure increases sharply, about 18MPa. If the power supply of the controller is powered on, the system works in the state of energy recovery. The fourth pressure sensor detects that the pressure in the large chamber of the boom cylinder is above 16MPa and the first pressure sensor detects that the joystick controls the brake. When the boom is lowered, the controller controls the boom locking control valve to be energized, the low-pressure recovery valve to be de-energized, the high-pressure recovery valve to be energized, and the control oil port of the boom locking valve is connected to the oil tank. At this time, the boom locking valve is closed, and The low-pressure recovery valve is also closed, and the oil in the large chamber of the boom cylinder enters the high-pressure accumulator from the high-pressure recovery valve. The minimum working pressure of the high-pressure accumulator is set at 16MPa to prevent the low-pressure The moment the recovery valve is opened, the boom drops instantly, and the maximum working pressure of the high-pressure accumulator is set by the safety valve. Since the excavator is loaded and the boom lowering process generally only occurs when unloading soil, this time may Since the position of the boom is not suitable for unloading soil, the position of the boom will be adjusted with a small displacement, so the nominal volume of the high-pressure accumulator is sufficient to recover the oil of 10% of the total stroke of the boom cylinder;

Energy release method: The oil recovered by the low-pressure accumulator and the high-pressure accumulator needs to be released again to save energy; when the pressure of the low-pressure accumulator is higher than 12MPa, the low-pressure release valve is opened, and the oil in the low-pressure accumulator passes through The first shuttle valve enters the oil inlet of the auxiliary motor for release; when the pressure of the high-pressure accumulator is higher than 16.2MPa, the high-pressure release valve is opened, and the oil of the high-pressure accumulator enters the auxiliary motor through the first shuttle valve. The displacement of the auxiliary motor is determined according to the displacement of the control handle, that is, the pressure detected by the first pressure sensor. The larger the displacement of the control handle, the larger the opening of the hydraulic control reversing valve and the faster the boom lowering speed. Fast, the displacement of the auxiliary motor changes in proportion to the pressure of the first pressure sensor to maintain a relatively constant pressure in the accumulator; the auxiliary motor drives the main pump and the pilot pump to rotate together with the engine, thereby reducing the power of the engine and realizing energy saving ;

Accumulator unloading method: When the excavator stops for a long time and does not work, the oil recovered in the low-pressure accumulator and high-pressure accumulator needs to be released, otherwise the accumulator will hold high pressure for a long time and damage the service life of the accumulator At this time, by opening the shut-off valve, the oil in the low-pressure accumulator and the high-pressure accumulator will return to the oil tank through the second shuttle valve through the shut-off valve;

Auxiliary motor replenishment method: When the accumulator is not released, the auxiliary motor works at the displacement, the engine drives the auxiliary motor to rotate, and the auxiliary motor basically consumes no engine power, but if the oil inlet of the auxiliary motor sucks oil from the fuel tank, It may be due to the low oil pressure in the fuel tank that it can only absorb a small amount of oil to the oil inlet of the auxiliary motor over a long distance. The back pressure valve cooperates with the third one-way valve and the fourth one-way valve to supply oil to the auxiliary motor, so as to increase the oil supply pressure and improve the oil supply effect;

Boom locking method: When the original system stops, because the boom locking valve adopts the structure of a cartridge valve, its self-locking performance is good, and the boom will not drop. Therefore, in the increased energy recovery circuit, the high-pressure recovery valve Both the low-pressure recovery valve and the low-pressure recovery valve adopt the structure of a screw-in cartridge valve, which solves the problem that the boom may not be locked due to the addition of a bypass.

Compared with the background technology, the beneficial effect of the present invention is that by recovering the potential energy of the boom in stages, the potential energy of the boom under different working conditions can be fully recovered, which breaks through the traditional energy recovery method that can only perform energy recovery for one working condition. The limitation of recycling greatly improves the energy saving efficiency. By recovering energy to two accumulators with different pressure ranges and unequal nominal volumes, since the boom generally works under no-load and descends, the volume of low-pressure oil that can be recovered is large, so a low-pressure large-volume accumulator is used to recover the empty space. When unloading, the boom will carry the load and descend for a short distance. At this time, a high-pressure and large-volume accumulator is used to recover the potential energy of the boom when it is loaded, which solves the problem that the traditional single-type accumulator only recovers The defect of potential energy when the boom is unloaded not only increases the volume of recovered oil, but also solves the difficulty of judging the loaded state. When recovering with load, the boom will drop rapidly due to the low pressure of the accumulator, and the control is not good. The phenomenon of living. Moreover, by controlling the proportional change of the auxiliary motor by the controller, the recovered oil and the released oil can be roughly equal instantaneously, so that the back pressure of the large cavity is balanced and the speed is stable. At the same time, this system can integrate functions such as energy recovery switch control, boom load recovery, accumulator unloading, auxiliary motor oil replenishment, boom locking and other functions, with high integration, the recovery and release of boom potential energy through the controller control, which not only simplifies the system, but also facilitates debugging. Greatly improved the portability of technology.

Description of drawings

Fig. 1 is a functional block diagram of the control system of the present invention.

In the figure, pilot pump 1, main pump 2, operating handle 3, first pressure sensor 4, boom lock control valve 5, hydraulic control reversing valve 6, first shuttle valve 7, boom lock valve 8, low pressure Release valve 9, low pressure accumulator 10, second pressure sensor 11, low pressure recovery valve 12, third pressure sensor 13, fourth pressure sensor 14, boom cylinder 15, second shuttle valve 16, first check valve 17 , the fifth pressure sensor 18, the controller 19, the second one-way valve 20, the high-pressure recovery valve 21, the high-pressure accumulator 22, the safety valve 23, the stop valve 24, the high-pressure release valve 25, the third one-way valve 26, the first Four check valves 27, back pressure valve 28, auxiliary motor 29, engine 30.

detailed description

The specific embodiment of the present invention will be described below in conjunction with accompanying drawing 1 .

As shown in Figure 1, a boom potential energy classification recovery and release device. It mainly includes the pilot pump (1, the main pump (2), the operating handle 3, the first pressure sensor 4, the boom lock control valve 5, the hydraulic control reversing valve 6, the first shuttle valve 7, the boom lock Valve 8, low pressure release valve 9, low pressure accumulator 10, second pressure sensor 11, low pressure recovery valve 12, third pressure sensor 13, fourth pressure sensor 14, boom cylinder 15, second shuttle valve 16, first Check valve 17, fifth pressure sensor 18, controller 19, second check valve 20, high pressure recovery valve 21, high pressure accumulator 22, safety valve 23, stop valve 24, high pressure release valve 25, third check valve Valve 26 , fourth one-way valve 27 , back pressure valve 28 , auxiliary motor 29 , engine 30 .

The connection relationship of each component in the system is as follows:

The engine 30 is connected to the main pump 2, the pilot pump 1 and the auxiliary motor 29 in sequence, the oil inlet of the main pump 2 is connected to the oil tank, and the oil outlet is connected to the oil inlet P6 of the hydraulic control reversing valve 6; the hydraulic control reversing valve The oil return port T6 of 6 is connected with the fuel tank, the oil outlet B6 is connected with the rod cavity of the boom cylinder 15, the oil outlet A6 is connected with the oil inlet of the boom lock valve 8; the outlet of the boom lock valve 8 The oil port is connected with the rodless cavity of the boom cylinder 15; the rodless cavity of the boom cylinder 15 is connected with the oil inlet of the first check valve 17, the oil inlet of the second check valve 20, and the high pressure recovery valve 21 respectively. The control oil port is connected to the control oil port of the low-pressure recovery valve 12;

The oil outlet of the first one-way valve 17 is connected with the oil inlet of the low-pressure recovery valve 12, the oil return port of the low-pressure recovery valve 12 is connected with the oil tank, and the oil outlet of the low-pressure recovery valve 12 is respectively connected with the low-pressure accumulator 10, the low-pressure The oil inlet of the relief valve 9 is connected; the oil outlet of the low-pressure relief valve 9 is connected with an oil inlet of the first shuttle valve 7;

The oil outlet of the second one-way valve 20 links to each other with the oil inlet of high-pressure recovery valve 21; The oil inlet of the release valve 25 is connected; the oil outlet of the high pressure release valve 25 is connected with another oil inlet of the first shuttle valve 7;

The oil outlet of the first shuttle valve 7 links to each other with the oil outlet of the fourth one-way valve 27 and the oil inlet of the auxiliary motor 29 respectively; The oil outlet, the oil outlet of the auxiliary motor 29, and the oil inlet of the back pressure valve 28 are connected, the oil outlet of the back pressure valve 28 is connected with the fuel tank, and the oil inlet of the third one-way valve 26 is connected with the fuel tank;

One oil inlet of the second shuttle valve 16 is connected with the low-pressure accumulator 10, the other oil inlet is connected with the high-pressure accumulator 22, and the oil outlet is respectively connected with the oil inlet of the safety valve 23 and the oil inlet of the stop valve 24. The oil outlet of the safety valve 23 is connected to the fuel tank, and the oil outlet of the stop valve 24 is connected to the fuel tank.

The oil inlet of the pilot pump 1 is connected to the oil tank, and the oil outlet is connected to the oil inlet P3 of the operating handle 3 to provide hydraulic control force to the operating handle 3, and the operating handle 3 is used to control the opening direction and opening direction of the hydraulic control reversing valve 6. The displacement of the spool, the oil outlet A3 of the operating handle 3 is connected with the control port XA of the hydraulic control reversing valve 6, and the oil outlet B3 is respectively connected with the control port XB of the hydraulic control reversing valve 6 and the inlet of the boom locking control valve 5. The oil port is connected; the oil return port of the boom lock control valve 5 is connected with the oil tank, and the oil outlet is connected with the control oil port of the boom lock valve 8;

The first pressure sensor 4 is used to measure the pressure of the oil outlet B3 of the operating handle 3, the second pressure sensor 11 is used to measure the pressure of the low-pressure accumulator 10, and the third pressure sensor 13 is used to measure the pressure of the rod chamber of the boom cylinder 15. Pressure, the fourth pressure sensor 14 is used to measure the pressure of the rodless cavity of the boom cylinder 15, and the fifth pressure sensor 18 is used to measure the pressure of the high-pressure accumulator 22;

All pressure sensor signals are connected to the input of the controller 19, and the switches of the low-pressure recovery valve 12, high-pressure recovery valve 21, low-pressure release valve 9, high-pressure release valve 25 and the displacement of the auxiliary motor 29 are controlled according to the program in the controller 19 .

In addition, the high-pressure recovery valve and the low-pressure recovery valve are electromagnetic reversing valves or hydraulic control reversing valves, and the control methods of these two valves are the same.

In addition, the optimal solution for the high-pressure recovery valve and the low-pressure recovery valve is a threaded cartridge valve as the main valve, and a solenoid valve as the pilot valve.

In addition, the high-pressure release valve and the low-pressure release valve are two-position two-way electromagnetic switch valves.

In addition, the boom locking control valve is a two-position three-way electromagnetic switch valve.

In addition, the stop valve is a manual on-off valve or an electromagnetic on-off valve.

A working method of an excavator boom potential energy classification recovery and release device is as follows:

Energy recovery switching method: when the controller 19 is powered off, all solenoid valves are powered off, and the displacement of the auxiliary motor 29 is also equal to 0. At this time, the boom locking control valve 5 is in the spring position, and the outlet pressure of the pilot pump 3 The boom lock valve 5 reaches the control oil port of the boom lock valve 8, the boom lock valve 8 is opened, and the low-pressure recovery valve 12 and high-pressure recovery valve 21 are closed. When the boom is lowered, the boom cylinder 15 has a large chamber The oil is from the boom lock valve 8 to the hydraulic control reversing valve 6, and then returns to the oil tank. At this time, the system is the same as that of an ordinary excavator; The signal collected by the sensor gives the solenoid valve switching command and the auxiliary motor 29 displacement command according to the internal program of the controller 19. At this time, the system is working in the energy recovery state, which can make the excavator return to the original system when the energy recovery system fails. normal work;

No-load energy recovery method: When the excavator in the original system descends under no load, the oil in the 15th cavity of the boom cylinder returns to the oil through the hydraulic control reversing valve 6. The pressure in the large chamber of the boom cylinder 15 is maintained at about 12MPa. If the controller 19 is powered on, the system works in the energy recovery state. The fourth pressure sensor 14 detects that the pressure in the boom cylinder 15 is below 16MPa and the first pressure When the sensor 4 detects that the joystick 3 controls the lowering of the boom, and the pressure difference between the fourth pressure sensor 14 and the second pressure sensor 11 is less than 2 MPa, the controller 19 controls the boom lock control valve 5 to be powered on, and the low pressure recovery valve 12 to be powered on. Electricity, high-pressure recovery valve 21 is powered off, the control oil port of the boom lock valve 8 is connected to the oil tank, at this time the boom lock valve 8 is closed, and the high-pressure recovery valve 21 is also closed, and the oil in the large cavity of the boom cylinder 15 is The low-pressure recovery valve 12 enters the low-pressure accumulator 10. In order to prevent the moment the low-pressure recovery valve 12 opens due to the low pressure of the accumulator, the boom will drop instantly. The minimum working pressure of the low-pressure accumulator 10 is set to 11MPa , and when the pressure difference between the fourth pressure sensor 14 and the second pressure sensor 11 is greater than 2 MPa, the low-pressure recovery valve 12 will not open, and the maximum working pressure of the low-pressure accumulator 10 is set by the safety valve 23, and its nominal volume meets the energy recovery dynamic Oil fluid for 60% of the total stroke of the arm cylinder 15;

On-load energy recovery method: When the excavator in the original system is under load, although the quality of the excavated materials is much smaller than that of the entire boom, bucket, and stick, due to the increase in torque, the 15 large cavity of the boom cylinder The pressure increases sharply, about 18MPa. If the controller 19 is powered on, the system works in the state of energy recovery, the fourth pressure sensor 14 detects that the pressure in the large chamber of the boom cylinder 15 is above 16MPa and the first pressure sensor 4 detects When the joystick 3 controls the lowering of the boom, the controller 19 controls the boom locking control valve 5 to be energized, the low-pressure recovery valve 12 is de-energized, the high-pressure recovery valve 21 is energized, and the control oil port of the boom locking valve 8 is connected to the oil tank , at this time the boom lock valve 8 is closed, and the low-pressure recovery valve 12 is also closed, the oil in the large chamber of the boom cylinder 15 enters the high-pressure accumulator 22 from the high-pressure recovery valve 21, and the minimum value set by the high-pressure accumulator 22 The working pressure is 16MPa, to prevent the moment when the low-pressure recovery valve 12 is opened due to the low pressure of the accumulator, the boom will drop instantly. The maximum working pressure of the high-pressure accumulator 22 is set by the safety valve 23. Since the excavator is loaded Sometimes, the lowering process of the boom generally only occurs when the soil is unloaded. At this time, the position of the boom may be adjusted with a small displacement because the position of the boom is not suitable for unloading the soil. Therefore, the nominal volume of the high-pressure accumulator 22 meets the energy requirements. It is enough to recover the oil of 10% of the total stroke of the boom oil cylinder 15;

Energy release method: the oil recovered by the low-pressure accumulator 10 and the high-pressure accumulator 22 needs to be released again to save energy; when the pressure of the low-pressure accumulator 10 is higher than 12MPa, the low-pressure release valve 9 is opened, and the low-pressure accumulator 10 oil enters the oil inlet of the auxiliary motor 29 through the first shuttle valve 7 to be released; when the pressure of the high-pressure accumulator 22 is higher than 16.2MPa, the high-pressure release valve 25 is opened, and the oil in the high-pressure accumulator 22 Enter the oil inlet of the auxiliary motor 29 through the first shuttle valve 7, and release; the displacement of the auxiliary motor 29 is determined according to the displacement of the control handle 3, that is, the pressure detected by the first pressure sensor 4. The greater the displacement of the control handle 3, It shows that the larger the opening of the hydraulic control reversing valve 6, the faster the lowering speed of the boom, and the displacement of the auxiliary motor 29 changes in proportion to the pressure of the first pressure sensor 4 to maintain a relatively constant pressure in the accumulator; the auxiliary motor 29 and the engine 30 drive the main pump 2 and the pilot pump 1 to rotate, thereby reducing the power of the engine 30 and realizing energy saving;

Accumulator unloading method: When the excavator stops for a long time and does not work, the oil recovered in the low-pressure accumulator 10 and the high-pressure accumulator 22 needs to be released, otherwise the accumulator will be damaged by high pressure for a long time Service life, at this time, by opening the shut-off valve 24, the oil in the low-pressure accumulator 10 and the high-pressure accumulator 22 will return to the oil tank through the second shuttle valve 16 through the shut-off valve 24;

Auxiliary motor replenishment method: when the accumulator is not released, the auxiliary motor 29 works at 0 displacement, the engine 30 drives the auxiliary motor 29 to rotate, and the auxiliary motor 29 basically does not consume the power of the engine 30, but if the auxiliary motor 29 is If the oil port absorbs oil from the oil tank, it may be due to the low oil pressure in the oil tank that it can only absorb a small amount of oil to the oil inlet of the auxiliary motor 29 for a long distance. , set a back pressure valve 28 at the oil outlet of the auxiliary motor 29, cooperate with the third one-way valve 26 and the fourth one-way valve 27 to replenish oil for the auxiliary motor 29, increase the oil replenishment pressure, and improve the oil replenishment effect;

Boom locking method: when the original system stops, since the boom locking valve 8 adopts the structure of a cartridge valve, its self-locking performance is good, and the boom will not drop, so in the increased energy recovery circuit, the high-pressure recovery Both the valve 21 and the low-pressure recovery valve 12 adopt the structure of a screw-in cartridge valve, which solves the problem that the boom may not be locked due to the addition of a bypass.

The above-mentioned embodiment is only a preferred embodiment of the present invention, but the embodiment of the present invention is not limited by the above-mentioned embodiment, and any other changes, modifications, substitutions, combinations, Simplifications should be equivalent replacement methods, and all are included in the protection scope of the present invention.

Claims (9)

1. a kind of excavator swing arm potential energy classification recovery and release device, it is characterised in that including：Pioneer pump (1), main pump (2), It is operation handle (3), first pressure sensor (4), swing arm locking control valve (5), pilot operated directional control valve (6), the first shuttle valve (7), dynamic Arm lock valve (8), low pressure relief valve (9), low pressure accumulator (10), second pressure sensor (11), low pressure recovery valve (12), 3rd pressure sensor (13), the 4th pressure sensor (14), boom cylinder (15), the first check valve (17), the 5th pressure pass Sensor (18), controller (19), the second check valve (20), high pressure recovery valve (21), high pressure accumulator (22), high pressure relief valve (25), the 3rd check valve (26), the 4th check valve (27), counterbalance valve (28), servo-motor (29), engine (30)；

Engine (30) is sequentially connected with main pump (2), pioneer pump (1) and servo-motor (29), the oil inlet and fuel tank of main pump (2) It is connected, oil-out is connected with the oil inlet P 6 of pilot operated directional control valve (6)；The oil return inlet T 6 of pilot operated directional control valve (6) is connected with fuel tank, Oil-out B6 is connected with the rod chamber of boom cylinder (15), and oil-out A6 is connected with the oil inlet of swing arm lock valve (8)；Swing arm The oil-out of lock valve (8) is connected with the rodless cavity of boom cylinder (15)；The rodless cavity of boom cylinder (15) is single with first respectively Oil inlet, the oil inlet of the second check valve (20), the control port of high pressure recovery valve (21), low pressure recovery valve to valve (17) (12) control port is connected；

The oil-out of first check valve (17) is connected with the oil inlet of low pressure recovery valve (12), the oil return opening of low pressure recovery valve (12) Be connected with fuel tank, the oil-out of low pressure recovery valve (12) respectively with low pressure accumulator (10), the oil inlet of low pressure relief valve (9) It is connected；The oil-out of low pressure relief valve (9) is connected with an oil inlet of the first shuttle valve (7)；

The oil-out of second check valve (20) is connected with the oil inlet of high pressure recovery valve (21)；The oil return opening of high pressure recovery valve (21) Be connected with fuel tank, the oil-out of high pressure recovery valve (21) respectively with high pressure accumulator (22), the oil inlet of high pressure relief valve (25) It is connected；The oil-out of high pressure relief valve (25) is connected with another oil inlet of the first shuttle valve (7)；

The oil-out with the 4th check valve (27), the oil inlet of servo-motor (29) are connected the oil-out of first shuttle valve (7) respectively； The oil inlet of 4th check valve (27) oil-out, the oil-out of servo-motor (29), back pressure with the 3rd check valve (26) respectively The oil inlet of valve (28) is connected, and the oil-out of counterbalance valve (28) is connected with fuel tank, the oil inlet and fuel tank of the 3rd check valve (26) It is connected；

The oil inlet of pioneer pump (1) is connected with fuel tank, and oil-out is connected with operation handle (3) oil inlet P 3, gives operation handle (3) Hydraulic control power is provided, operation handle (3) is used for controlling the opening direction of pilot operated directional control valve (6) with opening spool displacement, operation Handle (3) oil-out A3 is connected with the control mouth XA of pilot operated directional control valve (6), the oil-out B3 controls with pilot operated directional control valve (6) respectively Donsole XB, the oil inlet of swing arm locking control valve (5) are connected；The oil return opening of swing arm locking control valve (5) is connected with fuel tank, goes out Hydraulic fluid port is connected with the control port of swing arm lock valve (8)；

First pressure sensor (4) is used for the pressure for measuring operation handle (3) oil-out B3, and second pressure sensor (11) is used for The pressure of low pressure accumulator (10) is measured, the 3rd pressure sensor (13) is used for the pressure for measuring boom cylinder (15) rod chamber, 4th pressure sensor (14) is used for the pressure for measuring boom cylinder (15) rodless cavity, and the 5th pressure sensor (18) is used to survey Measure the pressure of high pressure accumulator (22)；

The input of all pressure sensor signal access controllers (19), and control low pressure is opened according to controller (19) internal program Recovery valve (12), high pressure recovery valve (21), low pressure relief valve (9), the switch of high pressure relief valve (25) and servo-motor (29) Discharge capacity.

2. a kind of excavator swing arm potential energy classification recovery as claimed in claim 1 and release device, it is characterised in that also include Second shuttle valve (16), safety valve (23), stop valve (24)；One oil inlet of described the second shuttle valve (16) and low pressure accumulation of energy Device (10) is connected, and another oil inlet is connected with high pressure accumulator (22), and oil-out connects the oil inlet of safety valve (23), cut respectively The only oil inlet of valve (24), the oil-out of safety valve (23) are connected with fuel tank, and the oil-out of stop valve (24) is connected with fuel tank.

3. excavator swing arm potential energy classification recovery as claimed in claim 1 and release device, it is characterised in that described high pressure Recovery valve and low pressure recovery valve are solenoid directional control valve or pilot operated directional control valve, and the control mode of the two valves is identical.

4. excavator swing arm potential energy classification recovery as claimed in claim 3 and release device, it is characterised in that described high pressure The optimal case of recovery valve and low pressure recovery valve is that main valve is screw-in cartridge valve, and pilot valve is magnetic valve.

5. excavator swing arm potential energy classification recovery as claimed in claim 1 and release device, it is characterised in that described high pressure Relief valve and low pressure relief valve are bi-bit bi-pass electromagnetic switch valve.

6. excavator swing arm potential energy classification recovery as claimed in claim 1 and release device, it is characterised in that described swing arm Locking control valve is two-position three-way electromagnetic switch valve.

7. excavator swing arm potential energy classification recovery as claimed in claim 2 and release device, it is characterised in that described cut-off Valve is hand switch valve or electromagnetic on-off valve.

A kind of 8. movable arm potential energy classification recovery and method for releasing such as any one of claim 1-7 described device, it is characterised in that Method is as follows：

Energy regenerating method of switching：When needing to close energy regenerating, controller (19) power cut-off, all magnetic valves lose Electricity, the discharge capacity of servo-motor (29) are equal to 0, and now swing arm locking control valve (5) is in spring position, pioneer pump (3) outlet pressure The control port of swing arm lock valve (8) is reached through swing arm locking control valve (5), swing arm lock valve (8) is opened, and low pressure reclaims Valve (12) and high pressure recovery valve (21) are closed, and the fluid slave arm lock valve (8) of the big chamber of boom cylinder (15) arrives when swing arm declines Pilot operated directional control valve (6), then oil return box；When needing to open energy regenerating, controller (19) power supply obtains electric, controller (19) root The signal come according to the collection of all pressure sensors provides electromagnetic valve switch instruction and the instruction of servo-motor (29) discharge capacity, now System is operated in energy recovery state；

Unload energy recovery method：During energy regenerating closed mode, when zero load declines, the fluid of the big chamber of boom cylinder (15) is through liquid Reversal valve (6) oil return liquid is controlled, due to the effect of pilot operated directional control valve (6) throttling spool, ties up the pressure of the big chamber of boom cylinder (15) Hold in 12MPa；When controller (19) power supply obtains electric, system is operated in energy recovery state, when the pressure of the big chamber of boom cylinder (15) Power declines in below 16MPa and control crank (3) control swing arm, and the 4th pressure sensor (14) senses with second pressure When the pressure difference of device (11) is less than 2MPa, controller (19) control swing arm locking control valve (5) obtains electric, low pressure recovery valve (12) and obtained Electricity, high pressure recovery valve (21) dead electricity, the control port connected tank of swing arm lock valve (8), now swing arm lock valve (8) closing, and And high pressure recovery valve (21) is also switched off, the big chamber fluid of boom cylinder (15) enters low pressure accumulation of energy from low pressure recovery valve (12) Device (10), in order to prevent because energy storage pressure is too small, and low pressure recovery valve (12) is set to open moment, swing arm moment drops, low pressure The minimum operating pressures that accumulator (10) is set is 11MPa, and the 4th pressure sensor (14) and second pressure sensor (11) Pressure difference when being more than 2MPa, low pressure recovery valve (12) is not turned on, and the maximum working pressure of low pressure accumulator (10) is by safety valve (23) set, its nominal volume meets the fluid that can reclaim the total kilometres of boom cylinder (15) 60%；

Band carries energy reclaiming method：When original system excavator band carries decline, although the more whole swing arm of the quality of material excavated, shovel Bucket, the quality of dipper are much smaller, but due to the increase of torque so that the pressure of the big chamber of boom cylinder (15) increased dramatically, about 18MPa, if controller (19) power supply obtains electric, system is operated in energy recovery state, and the 4th pressure sensor (14) detects The pressure of the big chamber of boom cylinder (15) detects that control crank (3) controls in more than 16MPa and first pressure sensor (4) When swing arm declines, controller (19) control swing arm locking control valve (5) obtains electric, low pressure recovery valve (12) dead electricity, high pressure recovery valve (21) electric, the control port connected tank of swing arm lock valve (8) is obtained, now swing arm lock valve (8) is closed, and low pressure recovery valve (12) it is also switched off, the big chamber fluid of boom cylinder (15) enters high pressure accumulator (22) from high pressure recovery valve (21), and high pressure stores The minimum operating pressures that energy device (22) is set is prevented because energy storage pressure is too small as 16MPa, and opens low pressure recovery valve (12) Open moment, swing arm moment is dropped, and the maximum working pressure of high pressure accumulator (22) is set by safety valve (23), due to excavator With carry when and swing arm decline process typically only occur in unload soil when, this when may due to swing arm position not It is adapted to unload soil, swing arm position can be adjusted thin tail sheep, so the nominal volume of high pressure accumulator (22) meets that swing arm oil can be reclaimed The fluid of the total kilometres of cylinder (15) 10%；

Energy releasing method：The fluid that low pressure accumulator (10) reclaims with high pressure accumulator (22), which need to discharge utilization again, to be saved Energy；When the pressure of low pressure accumulator (10) is higher than 12MPa, that is, open low pressure relief valve (9), the oil of low pressure accumulator (10) Liquid enters servo-motor (29) oil inlet through the first shuttle valve (7), is discharged；When the pressure of high pressure accumulator (22) is higher than During 16.2MPa, that is, high pressure relief valve (25) is opened, the fluid of high pressure accumulator (22) enters servo-motor through the first shuttle valve (7) (29) oil inlet, discharged；The discharge capacity of servo-motor (29) is according to the displacements of control crank (3), i.e. first pressure sensor (4) pressure of detection determines that the displacement of control crank (3) is bigger, illustrate that the opening of pilot operated directional control valve (6) is bigger, under swing arm Reduction of speed degree is faster, and the discharge capacity of servo-motor (29) changes with the proportional pressure of first pressure sensor (4), to maintain accumulation of energy Pressure relative constancy in device；Servo-motor (29) drives main pump (2) and pioneer pump (1) to rotate together with engine (30), from And the power of engine (30) is reduced, realize energy-conservation.

It is 9. a kind of such as the servo-motor oil supplement method of any one of claim 1-7 described device, it is characterised in that method is as follows：

When accumulator does not discharge, now servo-motor (29) is operated in 0 discharge capacity, and engine (30) drives servo-motor (29) rotation Turn, servo-motor (29) does not expend engine (30) power, but if the oil inlet of servo-motor (29) if the fuel tank oil suction, Because fuel tank oil liquid pressure is relatively low, a small amount of fluid can only be absorbed over long distances to servo-motor (29) oil inlet, now servo-motor (29) it can be emptied, it is necessary to design other feed circuit for it, one counterbalance valve (28) is set in servo-motor (29) oil-out, It is servo-motor (29) repairing together to coordinate the 3rd check valve (26), the 4th check valve (27), improves oil compensation pressure, improves and mends Oily effect.