CN103452150B - Hybrid power hydraulic excavator system adopting movable arm closed control - Google Patents

Abstract

The invention discloses a hybrid hydraulic excavator system with closed control of the boom. The system includes an internal combustion engine, a multi-way valve group, a variable displacement hydraulic pump, a generator, an electric energy storage unit, a boom control system, a swing control system, Bucket hydraulic cylinder and stick hydraulic cylinder, the system is driven by a motor with variable speed and the three-port hydraulic pump directly controls the boom hydraulic cylinder to realize the up and down movement of the hydraulic excavator arm; the swing control system controls the swing motor/generator Realize the rotation of the upper rotating body of the hydraulic excavator relative to the lower traveling body; the system adopts a hybrid drive mode, and the potential energy of the boom and the kinetic energy of the rotation can be directly converted into electrical energy and stored in an electrical energy storage unit. The invention conveniently realizes the recovery and release of the potential energy of the control boom, and has the advantages of high energy efficiency, simplified structure, low fuel consumption of the whole machine, high work efficiency and energy utilization rate, and the like.

Description

Hybrid Hydraulic Excavator System with Boom Closed Control

technical field

The invention relates to a hybrid power hydraulic excavator, in particular to a hybrid power hydraulic excavator system in which the boom adopts a closed control mode.

Background technique

During the working process of the hydraulic excavator, due to the up and down swing of the boom, stick and bucket and the rotary motion of the rotary mechanism are very frequent. And a lot of energy is wasted when the boom is lowered. In order to reduce the waste of this part of energy and protect the hydraulic components, it is necessary to recycle the kinetic energy of the hydraulic excavator's slewing braking and the potential energy of the lowering of the boom. The hybrid driving method proposed in recent years provides convenient conditions for the storage and reuse of hydraulic excavator potential energy. The invention patent authorized on 2012.11.07, the control device for hybrid construction machinery (CN200980110700.3) discloses such a The system adopts the coaxial connection of the hydraulic motor, the variable hydraulic pump and the motor generator as the energy conversion unit. On the one hand, the potential energy under the arm of the excavator and the kinetic energy of the slewing brake are converted into electric energy through the hydraulic motor to drive the generator and stored in high voltage. In the battery, it can also drive the variable hydraulic pump to regenerate this part of energy. The disadvantage is that the energy recovery system is more complicated, the number of regeneration conversions is high, and the efficiency is low; the invention patent authorized on 2012.03.07: hybrid construction machinery control method and In hybrid construction machinery (CN200880008679.1), a system consisting of a generator and a motor is used to independently control the rotary motion of the excavator. The disadvantage is that only the kinetic energy of the rotary braking of the excavator can be recovered and reused, and the potential energy under the boom cannot be used. , and there is no energy storage unit in the system.

Contents of the invention

The purpose of the present invention is to provide a hybrid hydraulic excavator drive system based on the closed control of the boom to realize the hydraulic Efficient recovery and reuse of the potential energy of the excavator arm. The electric motor/generator is used to convert the rotary braking kinetic energy and the potential energy of the boom lowering into electric energy, which is stored in the additional electric energy storage unit. Utilization, in order to minimize the energy consumption of the hydraulic excavator operation process.

The hybrid hydraulic excavator system with closed boom control includes internal combustion engine, multi-way valve group, variable displacement hydraulic pump, generator, electric energy storage unit, boom control system, swing control system, bucket hydraulic cylinder and stick hydraulic pressure cylinder; characterized in that:

The boom control system is composed of a boom inverter, a variable speed motor, a control unit, a three-port hydraulic pump, an accumulator, a small diameter hydraulic control check valve, a safety valve and a boom hydraulic cylinder; The electric energy storage unit is connected to the boom inverter, and the boom inverter is connected to the variable speed motor, and the variable speed motor drives the three-oil port hydraulic pump, and the first oil inlet and outlet P _A of the three-oil port hydraulic pump It is connected with the rodless chamber of the boom hydraulic cylinder, the second oil inlet and outlet port P _B is connected with the rod chamber of the boom hydraulic cylinder, and the suction and discharge port _PT is connected with the accumulator; the control unit collects data from the boom hydraulic cylinder The displacement signal or speed signal of the boom inverter controls the speed of the variable speed motor;

The slewing control system is composed of a slewing inverter and a slewing motor/generator, the slewing inverter is connected to the electric energy storage unit, and the slewing motor/generator is connected to the slewing inverter; the slewing inverter is controlled by the control unit; The control unit collects the rotation speed signal of the rotary motor/generator and controls the working state of the rotary motor/generator;

The internal combustion engine is connected with the variable displacement hydraulic pump and the generator, the generator is connected with the electric energy storage unit, the electric energy generated by the generator is stored in the electric energy storage unit, and the electric energy storage unit is connected with the boom inverter and the slewing inverter, The electric energy storage unit supplies power to the variable-speed motor and the rotary motor/generator, and the internal combustion engine drives the variable-displacement hydraulic pump and simultaneously drives the generator to generate electricity.

The charger is connected to the electric energy storage unit, and the charger is connected to the power supply.

The advantages of the present invention are:

1. The hydraulic cylinder of the boom is directly controlled by a three-port hydraulic pump without throttling loss, which facilitates the recovery and reuse of the potential energy of the control boom, without the need for multiple energy exchanges through the hydraulic motor and generator, and the energy recovery efficiency high.

2. The three-port hydraulic pump is driven by a motor with variable speed, so that the three-oil hydraulic pump only needs to use a hydraulic pump with a fixed displacement. Compared with the variable displacement control method, the structure is simplified; the power drive adopts a hybrid The power mode is conducive to increasing the load rate of the internal combustion engine, making the internal combustion engine work in the high-efficiency fuel range, thereby saving the fuel consumption of the whole machine.

3. Both the boom and the slewing are driven by motors. The potential energy of the boom and the kinetic energy of the slewing can be directly converted into electric energy storage, and they share one electric energy storage unit. The stored energy can complement and utilize each other, which improves the working efficiency of the whole machine and energy utilization.

Description of drawings

Fig. 1 is a working principle diagram of the driving system of the hydraulic excavator of the present invention.

In the figure, 01-boom control system, 02-swing control system, 1-internal combustion engine, 2-multi-way valve group, 3-variable displacement hydraulic pump, 4-generator, 5-electric energy storage unit, 6-rotating speed Variable motor, 7-control unit, 8-three oil port hydraulic pump, 9-accumulator, 10-A small diameter hydraulic control check valve, 11-B small diameter hydraulic control check valve, 12-A safety Valve, 13-B safety valve, 14-boom hydraulic cylinder, 15-swing motor inverter, 16-swing motor/generator, 17-bucket hydraulic cylinder, 18-stick hydraulic cylinder, 19-swing arm motor Inverter, 20-charger.

Detailed ways

The present invention is further described below in conjunction with accompanying drawing:

As shown in Figure 1, the hybrid hydraulic excavator driving system of the boom closed control system includes an internal combustion engine 1, a multi-way valve group 2, a variable displacement hydraulic pump 3, a generator 4, an electric energy storage unit 5, and a boom control system 01. Rotation control system 02. Bucket hydraulic cylinder 17 and arm hydraulic cylinder 18.

Boom control system 01 consists of boom inverter 19, variable speed motor 6, control unit 7, three-port hydraulic pump 8 that can balance the area difference of differential hydraulic cylinders, accumulator 9, and two small-diameter hydraulic pumps. Control check valve 10,11, two safety valves 12,13 and boom hydraulic cylinder 14 are formed. In the boom control system 01, the electric energy storage unit 5 is connected to the boom inverter 19, and the boom inverter 19 is connected to the variable-speed motor 6, and the variable-speed motor 6 drives the three-oil port hydraulic pump 8, and the three-oil port The first oil inlet and outlet P _A of the hydraulic pump 8 is connected with the rodless chamber of the boom hydraulic cylinder 14, the second oil inlet and outlet P _B is connected with the rod chamber of the boom hydraulic cylinder 14, and the oil suction and discharge port P _T is connected with the rod chamber of the boom hydraulic cylinder 14. The accumulators 9 are connected; the A safety valve 12 is connected in parallel with the A small diameter hydraulic control check valve 10, and the O port of the A safety valve and the oil inlet port of the A small diameter hydraulic control check valve are connected to the three oil port hydraulic pump The oil suction and discharge port P _T of 8, the P port of the A safety valve and the oil outlet of the A small-bore hydraulic control check valve are connected to the first oil inlet and outlet P _A of the three-port hydraulic pump 8; the B safety valve is connected to the B small The large-bore hydraulic control check valves are connected in parallel, the O port of the B safety valve and the oil inlet port of the B small-bore hydraulic control check valve are connected to the suction and discharge port P _T of the three-port hydraulic pump 8, and the P port of the B safety valve and the The oil outlet of the B small diameter hydraulic control check valve is connected to the second oil inlet and outlet P _B of the three oil port hydraulic pump.

The swing control system 02 is composed of a swing transformer 15 and a swing motor/generator 16 , the swing inverter 15 is connected to the electric energy storage unit 5 , and the swing inverter 15 is connected to the swing motor/generator 16 .

The boom control system 01 controls the boom hydraulic cylinder 14 to realize the up and down movement of the boom of the hydraulic excavator, and the slewing control system 02 realizes the rotation of the upper rotating body of the hydraulic excavator relative to the lower traveling body by controlling the slewing motor/generator 16; The volume hydraulic pump 3 drives the excavator bucket hydraulic cylinder 17 and the stick hydraulic cylinder 18 to work through the multi-way valve group 2 .

The control unit 7 collects the displacement signal or speed signal of the boom hydraulic cylinder 14, and controls the speed of the variable speed motor 8 through the boom inverter 19; the rotary inverter 15 is controlled by the control unit 7; the control unit 7 collects the rotation speed The rotational speed signal of the motor/generator 16 controls the working state of the rotary motor/generator 16 .

When the whole machine is working, the internal combustion engine 1 is connected with the variable displacement hydraulic pump 3 and the generator 4, the internal combustion engine 1 drives the variable displacement hydraulic pump 3, and simultaneously drives the generator 4 to generate electricity; the generator 4 is connected with the electric energy storage unit 5, and the generator 4 The generated electric energy is stored in the electric energy storage unit 5 , which is connected with the boom inverter 19 and the swing inverter 15 , and the electric energy storage unit 5 supplies power for the speed variable motor 6 and the swing electric/generator 16 . The variable speed motor 6 drives the three-port hydraulic pump 8, and the control unit 7 collects the displacement or speed signal of the boom hydraulic cylinder 14, controls the speed of the variable speed motor 6, and realizes the control of the speed and direction of the three-port hydraulic pump 8 , so as to cooperate with the displacement of the three-port hydraulic pump 8 to improve the energy efficiency of the system.

When the boom is lowered, the piston rod of the boom hydraulic cylinder 14 retracts, the first oil inlet and outlet port P _A of the three-oil hydraulic pump 8 sucks oil from the rodless chamber of the boom hydraulic cylinder 14, and the first oil port of the three-oil hydraulic pump 8 2 The oil inlet and outlet port P _B supplies oil to the rod chamber of the boom hydraulic cylinder 14, and the excess high-pressure oil from the rodless chamber enters the accumulator 9 through the oil suction and discharge ports to realize potential energy recovery; when the boom is lifted, the boom The piston rod of the hydraulic cylinder 14 is stretched out, the first oil inlet and outlet P _A of the three-oil hydraulic pump 8 supplies oil to the rodless chamber, and the second oil inlet and outlet P _B sucks oil from the rod chamber, and there is not enough oil in the rodless chamber Supplemented by accumulator 9.

When the excavator turns and starts, accelerates, and turns at a constant speed, the turning motor/generator 16 is in the motor working state, and the control unit 7 controls the turning inverter 15 to realize that the electric energy storage unit 5 supplies electric energy to the turning motor/generator 16; when excavating When the machine is in slewing braking, the slewing motor/generator 16 is in the working state of a generator, and the control unit 7 controls the slewing inverter 15 to realize the storage of the power generated by the slewing motor/generator 16 to the electric energy storage unit 5.

When there is a power supply near the excavator, or the excavator is stored in a place with power supply, the charger 20 is connected to the power supply for charging, and the charger 20 is connected to the electric energy storage unit 5, and the charger 20 can be used to charge the electric energy storage unit 5. Supplement electrical energy, or put the machine in a fully electric state.

Claims (2)

1. a hybrid power hydraulic excavator system for swing arm enclosed control, comprises internal combustion engine, banked direction control valves group, becomes displacement hydraulic pump, generator, energy storage unit, swing arm control system, rotary control system, bucket hydraulic cylinder and dipper hydraulic cylinder; It is characterized in that:

Described swing arm control system is made up of swing arm inverter, variable speed motor, control unit, three hydraulic fluid port hydraulic pumps, accumulator, little latus rectum hydraulic control one-way valve, safety valve and swing arm hydraulic cylinder; Described energy storage unit is connected to swing arm inverter, and swing arm inverter is connected to variable speed motor, and variable speed motor drives three hydraulic fluid port hydraulic pumps, the 1st oil inlet and outlet P of three hydraulic fluid port hydraulic pumps _abe connected with the rodless cavity of swing arm hydraulic cylinder, the 2nd oil inlet and outlet P _bbe connected with the rod chamber of swing arm hydraulic cylinder, suction hydraulic fluid port P _tbe connected with accumulator; Control unit gathers displacement signal or the rate signal of swing arm hydraulic cylinder, through the rotating speed of swing arm inverter control variable speed motor;

Described rotary control system by turn round inverter, revolution dynamoelectric machine form, revolution inverter be connected with energy storage unit, revolution dynamoelectric machine with turn round inverter be connected; The controlled unit controls of revolution inverter; The tach signal of control unit collection revolution dynamoelectric machine also controls the duty of revolution dynamoelectric machine;

Described internal combustion engine is connected with change displacement hydraulic pump, generator, generator is connected with energy storage unit, the power storage that generator sends is in energy storage unit, energy storage unit and swing arm inverter, turn round inverter and be connected, energy storage unit is variable speed motor, revolution dynamoelectric machine is powered, internal combustion engine drive becomes displacement hydraulic pump, drives electrical power generators simultaneously.

2. the hybrid power hydraulic excavator system of a kind of swing arm enclosed control according to claim 1, it is characterized in that: charger is connected with energy storage unit, charger is connected on power supply.