阅读说明：本技术 一种混合动力挖掘机节能装置及挖掘机 (Hybrid excavator energy-saving device and excavator ) 是由 李建华 徐玉兵 金月峰 刘恩亮 宋士超 吕磊 于 2021-07-12 设计创作，主要内容包括：本发明公开了一种混合动力挖掘机节能装置及挖掘机,包括混合动力机构、动臂势能回收机构和回转势能回收机构；混合动力机构包括液压泵、发动机、第一发电机、电动机和超级电容,发动机通过第一离合器与液压泵相连,发动机还与第一发电机相连,第一发电机与超级电容相连,电动机分别与液压泵和超级电容相连；液压泵和动臂势能回收机构通过换向阀与动臂油缸相连,动臂势能回收机构与超级电容相连；回转势能回收机构包括与超级电容相连的回转驱动电机。本发明能够充分回收并利用动臂下降的势能、回转减速制动的惯性势能,实现纯电、增程、混动三种驱动方式,使发动机在最佳燃油经济区域工作,提高发动机的功率利用率,减少燃料的消耗,节能环保。(The invention discloses an energy-saving device of a hybrid excavator and the excavator, wherein the energy-saving device comprises a hybrid power mechanism, a movable arm potential energy recovery mechanism and a rotary potential energy recovery mechanism; the hybrid power mechanism comprises a hydraulic pump, an engine, a first generator, a motor and a super capacitor, wherein the engine is connected with the hydraulic pump through a first clutch, the engine is also connected with a first generator, the first generator is connected with the super capacitor, and the motor is respectively connected with the hydraulic pump and the super capacitor; the hydraulic pump and the movable arm potential energy recovery mechanism are connected with the movable arm oil cylinder through the reversing valve, and the movable arm potential energy recovery mechanism is connected with the super capacitor; the rotary potential energy recovery mechanism comprises a rotary driving motor connected with the super capacitor. The invention can fully recover and utilize the descending potential energy of the movable arm and the inertia potential energy of the rotation deceleration braking, realizes three driving modes of pure electricity, range extension and hybrid action, enables the engine to work in the optimal fuel economy area, improves the power utilization rate of the engine, reduces the fuel consumption, and is energy-saving and environment-friendly.)

1. The energy-saving device of the hybrid excavator is characterized by comprising a hybrid power mechanism, a movable arm potential energy recovery mechanism and a rotary potential energy recovery mechanism;

the hybrid power mechanism comprises a hydraulic pump, an engine, a first generator, a motor and a super capacitor, wherein the engine is connected with the hydraulic pump through a first clutch, the engine is also connected with a first generator, the first generator is connected with the super capacitor, and the motor is respectively connected with the hydraulic pump and the super capacitor;

the hydraulic pump and the movable arm potential energy recovery mechanism are connected with a movable arm oil cylinder through a reversing valve, and the movable arm potential energy recovery mechanism is connected with the super capacitor;

the rotary potential energy recovery mechanism comprises a rotary driving motor connected with the super capacitor.

2. The energy-saving device of the hybrid excavator according to claim 1, wherein the super capacitor is connected with a first frequency converter, and the first generator and the motor are both connected with the super capacitor through the first frequency converter.

3. The energy-saving device of a hybrid excavator according to claim 1, wherein the super capacitor is connected with a second frequency converter, and the boom potential energy recovery mechanism and the swing drive motor are both connected with the super capacitor through the second frequency converter.

4. The hybrid excavator economizer of claim 3 wherein the boom potential energy recovery mechanism comprises a hydraulic motor, a second clutch connected to the hydraulic motor, and a second generator connected to the second clutch, the second generator being connected to a second inverter.

5. The energy saving device of a hybrid excavator according to claim 1, wherein a swing gear engaged with the turntable gear is provided on an output shaft of the swing driving motor.

6. The hybrid excavator economizer of claim 1 wherein a pilot operated valve is also connected to the reversing valve, the pilot operated valve also being connected to the second clutch.

7. An excavator comprising the energy saving device for a hybrid excavator according to any one of claims 1 to 6.

Technical Field

The invention belongs to the technical field of excavators, and particularly relates to an energy-saving device of a hybrid excavator and the excavator.

Background

The excavator is a widely used engineering machine, various operation modes exist in the excavator construction process, operation objects are greatly changed, the working point of an engine cannot be stabilized in an economic area when the load power demand is high or low in the traditional excavator, and fuel consumption is serious. Meanwhile, the excavator needs a large amount of movable arm descending and rotating actions in the construction process, and when the movable arm descends, descending potential energy of the movable arm is converted into heat by hydraulic throttling and is wasted; inertial potential energy exists in the process of rotation deceleration braking, and the part of energy cannot be recycled, so that a large amount of heat is generated, and energy waste and part damage are caused.

In the traditional energy-saving device of the hybrid excavator, a generator motor between an engine and a hydraulic pump can only realize hybrid driving and cannot realize a pure electric driving or range extending mode, namely, the engine only charges a super capacitor, and the hydraulic pump is only driven by the motor; the accumulator at the oil return position of the rodless cavity of the movable arm hydraulic cylinder is large in size and difficult to use, and energy cannot be completely recovered; the oil/electricity rotary motor is used for replacing the traditional hydraulic rotary motor, although the energy of the rotary speed reduction brake can be absorbed, the oil consumption generated by using a control valve and a pipeline cannot be reduced, and a control system is complex.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provides an energy-saving device of a hybrid excavator and the excavator, which can fully recover and utilize the potential energy of descending of a movable arm and the inertia potential energy of rotation deceleration braking, realize three driving modes of pure electricity, range increase and hybrid, reduce the highest rotating speed of an engine, enable the engine to work in the optimal fuel economy area, improve the power utilization rate of the engine, reduce the consumption of fuel, save energy and protect environment.

The invention provides the following technical scheme:

an energy-saving device of a hybrid excavator comprises a hybrid power mechanism, a movable arm potential energy recovery mechanism and a rotary potential energy recovery mechanism;

the hybrid power mechanism comprises a hydraulic pump, an engine, a first generator, a motor and a super capacitor, wherein the engine is connected with the hydraulic pump through a first clutch, the engine is also connected with a first generator, the first generator is connected with the super capacitor, and the motor is respectively connected with the hydraulic pump and the super capacitor;

the hydraulic pump and the movable arm potential energy recovery mechanism are connected with a movable arm oil cylinder through a reversing valve, and the movable arm potential energy recovery mechanism is connected with the super capacitor;

the rotary potential energy recovery mechanism comprises a rotary driving motor connected with the super capacitor.

Furthermore, the super capacitor is connected with a first frequency converter, and the first generator and the motor are connected with the super capacitor through the first frequency converter.

Furthermore, the super capacitor is connected with a second frequency converter, and the movable arm potential energy recovery mechanism and the rotary driving motor are connected with the super capacitor through the second frequency converter.

Further, the movable arm potential energy recovery mechanism comprises a hydraulic motor, a second clutch connected with the hydraulic motor and a second generator connected with the second clutch, and the second generator is connected with a second frequency converter.

Furthermore, a rotary gear meshed with the turntable gear is arranged on an output shaft of the rotary driving motor.

Furthermore, the reversing valve is also connected with a pilot control valve, and the pilot control valve is also connected with the second clutch.

The excavator comprises the energy-saving device of the hybrid excavator.

Compared with the prior art, the invention has the beneficial effects that:

(1) the hybrid power system comprises a hybrid power mechanism, when the electric quantity of the super capacitor is sufficient, the first clutch is separated, the engine is not started, and the motor works alone to drive the hydraulic pump, so that a pure electric driving mode is realized, and the hybrid power system has the advantages of smoothness, zero oil consumption and the like; keeping the first clutch separated, starting the engine, generating power by the first generator to charge the super capacitor, and driving the hydraulic pump by the motor to realize a range extending mode; when the electric quantity of the super capacitor is exhausted, the first clutch is combined to start the engine to realize hybrid power driving, so that the engine works in an optimal fuel economy area when the load is changed, and the power utilization rate of the engine is improved;

(2) the movable arm potential energy recovery mechanism comprises a movable arm potential energy recovery mechanism, wherein the return oil energy of a rodless cavity of a movable arm oil cylinder is completely fed back to a power system, the descending potential energy of the movable arm can be fully recovered and utilized, the generation of heat energy is reduced, and the service life of parts is prolonged;

(3) the rotary potential energy recovery mechanism assists the rotary acceleration process by recovering the inertia potential energy of rotary deceleration braking, reduces the heat productivity, can prolong the service life of each component, and simultaneously can reduce the fuel consumption and the tail gas emission by energy recovery, thereby saving energy and protecting environment; in addition, the rotation of the excavator is controlled by the rotary driving motor, the use of control valves and pipelines is reduced, the oil consumption is reduced, and a control system is simplified.

Drawings

FIG. 1 is a schematic structural view of the present invention;

labeled as: 1. an engine; 2. an electric motor; 3. a first clutch; 4. a hydraulic pump; 5. a first generator; 6. a first frequency converter; 7. a super capacitor; 8. a second frequency converter; 9. a rotary drive motor; 10. a second generator; 11. a second clutch; 12. a hydraulic motor; 13. a diverter valve; 14. a boom cylinder; 15. the pilot operated valve.

Detailed Description

The invention is further described below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.

Example 1

As shown in fig. 1, the embodiment provides an energy saving device for a hybrid excavator, which includes a hybrid mechanism, a boom potential energy recovery mechanism and a swing potential energy recovery mechanism.

The hybrid power mechanism comprises a hydraulic pump 4, an engine 1, a first generator 5, a motor 2 and a super capacitor 7, wherein the engine 1 is connected with the hydraulic pump 4 through a first clutch 3, the engine 1 is also connected with the first generator 5, the first generator 5 is connected with the super capacitor 7, and the motor 2 is respectively connected with the hydraulic pump 4 and the super capacitor 7. Specifically, the super capacitor 7 is connected with a first frequency converter 6, and the first generator 5 and the motor 2 are both connected with the super capacitor 7 through the first frequency converter 6.

The super capacitor 7 is also connected with a second frequency converter 8. The boom potential energy recovery mechanism comprises a hydraulic motor 12, a second clutch 11 connected with the hydraulic motor 12 and a second generator 10 connected with the second clutch 11, wherein the second generator 10 is connected with the super capacitor 7 through a second frequency converter 8. The hydraulic pump 4 and the hydraulic motor 12 are connected with a boom cylinder 14 through a reversing valve 13, the reversing valve 13 is further connected with a pilot control valve 15, the pilot control valve 15 can open the reversing valve 13 to enable a rod cavity of the boom cylinder 14 to be filled with oil, so that the boom is controlled to descend, and the pilot control valve 15 is further connected with the second clutch 11.

The rotary potential energy recovery mechanism comprises a rotary driving motor 9 connected with the super capacitor 7 through a second frequency converter 8, and a rotary gear meshed with the turntable gear is arranged on an output shaft of the rotary driving motor 9.

Example 2

An excavator comprising the hybrid excavator energy saving device of embodiment 1.

The working principle of the invention is as follows:

the invention can realize three driving modes:

(1) pure electric mode: when the electric quantity of the super capacitor 7 is sufficient, the engine 1 is not started, the first clutch 3 is separated, and the motor 2 works alone to drive the hydraulic pump 4;

(2) a range extending mode: the engine 1 is started, the first clutch 3 is separated, the first generator 5 generates electricity to charge the super capacitor 7, and the motor 2 drives the hydraulic pump 4;

(3) mixing mode: when the load power demand is high, the engine 1 is started, the first clutch 3 is combined, the motor 2 works to drive the hydraulic pump 4 together, so that the output power of the engine 1 is reduced, and the engine 1 is ensured to work at the optimal fuel oil working point; when the load power demand is low, the motor 2 does not work, the engine 1 is started to drive the hydraulic pump 4, and the first generator 5 does not generate electricity or electricity according to the load power demand, so that the engine 1 is ensured to work at the optimal fuel oil working point.

The return oil of the rodless cavity of the movable arm oil cylinder 14 is divided into two paths and is respectively connected with an oil inlet of the hydraulic pump 4 and an oil inlet of the hydraulic motor 12. When the boom of the excavator descends, the pilot control valve 15 is turned to open the left pilot valve, the direction valve 13 is pushed to the left valve position, the second clutch 11 is engaged, and the hydraulic motor 12 is rotated. The boom cylinder 14 has a rod cavity for oil inlet, the rodless cavity is mainly compressed by gravity, and the return oil flows to the oil inlet of the hydraulic pump 4 and the oil inlet of the hydraulic motor 12 through the reversing valve 13. At this time, the oil return amount of the boom cylinder 14 is greater than the oil inlet amount, so the oil return can maintain pressure at the oil inlet of the hydraulic pump 4 to assist in driving the hydraulic pump 4 to rotate, that is, the hydraulic pump 4 absorbs the hydraulic energy of the return oil of the rodless cavity of the boom cylinder 14. Another part of the return oil flows to the hydraulic motor 12 to drive the hydraulic motor 12 to rotate and drive the second generator 10 to generate electricity, and the electricity is stored in the super capacitor 7 through the second frequency converter 8. When the boom is lifted, the return oil amount of the boom cylinder 14 is smaller than the oil inlet amount, so that the return oil flows to the oil inlet of the hydraulic pump 4 without resistance, or flows back to the oil tank through the auxiliary hydraulic motor 12 (in a free state due to clutch disengagement).

A rotary driving motor 9 is adopted to replace a traditional hydraulic rotary motor, the rotary driving motor 9 is in a generator mode in the rotary speed-reducing braking process, and a second frequency converter 8 converts alternating current generated by the rotary driving motor 9 into direct current, namely, inertial potential energy of the rotary speed-reducing braking is converted into electric energy to be stored in a super capacitor 7; in the process of rotation acceleration, the rotation driving motor 9 is in a motor mode, the second frequency converter 8 converts direct current of the super capacitor 7 into alternating current, and electric energy in the super capacitor 7 is released to drive the rotation driving motor 9 to rotate, start and accelerate.

In conclusion, the excavator realizes three driving modes of pure electricity, range extension and hybrid action by matching the first generator and the motor with the engine, reduces the highest rotating speed of the engine, enables the engine to work in the optimal fuel economy area, and improves the power utilization rate of the engine; according to the invention, the hydraulic motor and the second generator can fully absorb the gravitational potential energy generated by the descending of the movable arm, and the rotary driving motor can fully absorb the inertia potential energy generated by the rotary deceleration braking, so that the heat productivity is reduced, the service life of each component can be prolonged, the fuel consumption and the tail gas emission are reduced, and the energy-saving and environment-friendly effects are realized.

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.