WO2022257628A1

WO2022257628A1 - Electro-hydraulic parallel driving engineering machinery locomotion system

Info

Publication number: WO2022257628A1
Application number: PCT/CN2022/089150
Authority: WO
Inventors: 陈其怀; 蔡少乐; 林添良; 郭桐; 付胜杰; 任好玲; 李钟慎; 方燕飞
Original assignee: 华侨大学
Priority date: 2021-06-09
Filing date: 2022-04-26
Publication date: 2022-12-15
Also published as: CN113183753A

Abstract

An electro-hydraulic parallel driving engineering machinery locomotion system, comprising a mechanical transmission part (100), an electric driving part (200), a hydraulic driving part (300) and a locomotion execution part. The mechanical transmission part (100) comprises a power input shaft (109), a hydraulic input shaft (110), a power output shaft (111), a first transmission shaft (101), a second transmission shaft (102), a third transmission shaft (103), a fourth transmission shaft (104), a fifth transmission shaft (105), a sixth transmission shaft (106), and a seventh transmission shaft (107) which are arranged in parallel. The system integrates the advantages of an electric driving system and a hydraulic driving system, adopts an electric driving part and the hydraulic driving part to jointly drive mechanical locomotion, comprehensively exerts the advantages of good electric-transmission speed regulation performance and high hydraulic transmission power density, and is relatively low in energy consumption, sufficient in driving force and good in economy.

Description

An electro-hydraulic parallel driving construction machinery walking system

technical field

The invention relates to a walking system, in particular to a construction machinery walking system driven by electric hydraulic parallel.

Background technique

With the increasingly severe environmental problems and energy crisis, the concepts of energy saving, emission reduction and green environmental protection have gained recognition and attention from more and more countries. Due to the harsh working environment, rough roads, and complex and changeable working conditions of construction machinery (also known as construction vehicles), the energy consumption of its walking system is usually relatively high. Traditional construction machinery mostly uses torque converters + gearboxes. "Double variable" hydraulic transmission device realizes variable speed and torque. The hydraulic transmission has a relatively "soft" working characteristic that the output speed automatically decreases with the increase of the load, which can prevent the engine from being overloaded, but its transmission efficiency is low, and the torque ratio is greatly affected by the speed, especially under heavy load When the system needs to output high power, the transmission efficiency drops sharply, which not only reduces the working efficiency, but also causes huge waste of energy.

Electric construction machinery is considered to be one of the ideal driving methods. However, the working conditions and working modes of construction machinery are quite different from those of general vehicles. The research on electric drive technology in the field of construction machinery walking system is still in its infancy. stage, the following issues need to be addressed urgently:

(1) Low-speed high-torque drive under extreme working conditions: When the motor works at near zero speed, the torque controllability is poor, and its output power is greatly reduced, which is difficult to provide under extreme working conditions such as loader shoveling and bulldozer trenching. Plenty of motivation. If a separate high-energy battery + motor + torque converter-gearbox is used in the travel drive system, a torque converter with high energy consumption is used and energy recovery is not possible, resulting in low overall efficiency and relatively high energy consumption. The high-energy battery + motor + gearbox travel drive system cancels the torque converter, which improves the energy-saving effect of the vehicle. However, due to the limitation of the peak output power of the motor itself (generally twice the rated power and greatly Reduction) also leads to problems such as insufficient near-zero speed driving capability of the system.

(2) It is difficult to match the installed power: the average power of construction machinery is only 1/3-1/4 of the instantaneous peak power. If the driving motor is selected according to the peak power to meet the requirements of extreme working conditions, there will be a large installed capacity. Power surplus, and cannot effectively ensure that the operating point of the drive motor continues to operate in the high-efficiency area, and the economy is poor.

(3) The working condition of energy recovery fluctuates violently: In order to meet the needs of long-term operation, electric construction machinery generally uses energy-type batteries as energy sources, which is difficult to achieve high-rate current charging and discharging, and thus cannot efficiently recover instantaneous high-power braking during frequent start and stop energy.

In view of this, the applicant has carried out in-depth research on the above-mentioned problems, and this case arises.

Contents of the invention

The object of the present invention is to provide a construction machinery traveling system with relatively low energy consumption, sufficient driving force and good economical efficiency and parallel drive of electro-hydraulic.

In order to achieve the above object, the present invention adopts the following technical solutions:

An electro-hydraulic parallel-driven construction machinery walking system, comprising a mechanical transmission part, an electric drive part, a hydraulic drive part and a walking execution part respectively connected to the mechanical transmission part, and the mechanical transmission part includes electric drives arranged in parallel to each other. Input shaft, hydraulic input shaft, power output shaft, first transmission shaft, second transmission shaft, third transmission shaft, fourth transmission shaft, fifth transmission shaft, sixth transmission shaft and seventh transmission shaft, the electric input The shaft is in transmission connection with the electric drive part, the hydraulic input shaft is in transmission connection with the hydraulic drive part, the power output shaft is in transmission connection with the walking execution part, and the power input shaft is provided with an input gear, so The first transmission shaft is provided with a first gear and a second gear meshing with the input gear, and the first transmission shaft and the second transmission shaft are connected through a first clutch, and the second transmission A third gear is arranged on the shaft, the third transmission shaft and the hydraulic input shaft are connected through a second clutch, and a fourth gear meshing with the second gear is arranged on the third transmission shaft, The fourth transmission shaft is provided with a fifth gear meshing with the second gear, and the fourth transmission shaft and the fifth transmission shaft are connected through a third clutch, and the fifth transmission shaft is A sixth gear meshed with the third gear is provided, a seventh gear meshed with the first gear is arranged on the sixth transmission shaft, and the sixth transmission shaft and the seventh transmission shaft are connected through the fourth clutch, and the seventh transmission shaft is provided with an eighth gear that meshes with the third gear.

As an improvement of the present invention, the electric drive part includes a first motor-generator integrated machine, a first motor control module electrically connected to the first motor-generator integrated machine, and a charger electrically connected to the first motor control module. The battery is discharged, and the rotating shaft of the first motor-generator is connected to the power input shaft through transmission.

As an improvement of the present invention, the hydraulic drive part includes a pump-motor integrated machine, a main pump, an oil tank connected to the oil inlet of the main pump, and a first two-digit valve connected to the oil outlet of the main pump. A two-way electromagnetic reversing valve, a three-position four-way electromagnetic reversing valve communicated with the oil outlet of the first two-position two-way electromagnetic reversing valve, the oil return port of the three-position four-way electromagnetic reversing valve is connected to the The oil tank is connected, the two oil outlets of the three-position four-way electromagnetic reversing valve are respectively connected to the two oil ports of the pump-motor integrated machine through hydraulic oil pipes, and the two hydraulic oil pipes Oil supply pipes connected to the oil tank are respectively connected to the oil supply pipes, a check valve is arranged on the oil supply pipes, and the rotating shaft of the pump-motor integrated machine is connected to the hydraulic input shaft through transmission.

As an improvement of the present invention, the oil outlet of the main pump and the two oil ports of the pump-motor integrated machine are respectively connected with first safety valves, and the oil return ports of each of the first safety valves are connected with each other. The fuel tank connection.

As an improvement of the present invention, the oil outlet of the first two-position two-way electromagnetic directional valve is also connected with a second two-position two-way electromagnetic directional valve, and the second two-position two-way electromagnetic directional valve The oil outlets of the hydraulic accumulator and the second safety valve are respectively connected, and the oil return ports of the second safety valve are connected with the oil tank.

As an improvement of the present invention, pressure sensors are respectively connected to the oil outlets of the first 2/2-way electromagnetic directional valve and the oil outlets of the second 2/2-way electromagnetic directional valve.

As an improvement of the present invention, it also includes working and steering hydraulic devices, and the oil outlet of the main pump is connected with the working and steering hydraulic devices at the same time.

As an improvement of the present invention, the main pump is connected with a second motor-generator integrated machine, and the second motor-generator integrated machine is electrically connected with a second motor control module, and the second motor control module is connected to the charger. Discharge battery electrical connection.

As an improvement of the present invention, the charge-discharge battery is a lithium battery.

As an improvement of the present invention, a filter is installed on the oil outlet of the oil tank.

By adopting the above technical scheme, the present invention has the following beneficial effects:

1. The present invention combines the advantages of the electric drive system and the hydraulic drive system, uses the electric drive part and the hydraulic drive part to jointly drive the mechanical walking, and comprehensively exerts the advantages of good speed regulation performance of the electric drive and high power density of the hydraulic drive, and the energy consumption is relatively low. Low, plenty of drive and good economy.

2. Under high-speed working conditions, use the output torque of the pump-motor integrated machine to make up for the lack of torque caused by the increase in the speed of the first motor-generator integrated machine working in the constant power area. The output torque of the motor assists the driving of the walking motor. Under the extreme working conditions of construction machinery performing engineering operations (such as loader shoveling, bulldozer digging, etc.), the output torque of the pump-motor integrated machine is used to assist the first motor-generator integrated machine to drive the walking. The power level required to obtain the first electric motor integrated machine is greatly reduced.

3. The mechanical transmission part of the present invention cancels the directional clutch and the corresponding gears, and utilizes the characteristics of the first motor-generator integrated machine and the pump-motor integrated machine that can be forward and reversed to realize the forward and reverse of the whole vehicle, which improves the transmission efficiency of the whole vehicle. The installation space of the external oil circuit is reduced, the electrical control and mechanical structure are simplified, the reliability of the whole vehicle is greatly improved, the cost is reduced, and the economy is good.

4. Due to the work of construction machinery and the steering hydraulic device, there is a large degree of overflow loss, and the part of the lost energy is recovered through the hydraulic accumulator, which can be used for the hydraulic drive part or the working and steering hydraulic device. use.

5. By setting charging and discharging batteries and hydraulic accumulators, high-rate current charging and discharging can be realized, and instantaneous high-power braking energy can be efficiently recovered when frequent starts and stops.

Description of drawings

Fig. 1 is a schematic structural view of the construction machinery walking system driven by electro-hydraulic parallel drive of the present invention.

The markings in the figure correspond to the following:

100-mechanical transmission part; 101-first transmission shaft;

102-the second transmission shaft; 103-the third transmission shaft;

104-the fourth transmission shaft; 105-the fifth transmission shaft;

106-the sixth transmission shaft; 107-the seventh transmission shaft;

109-power input shaft; 110-hydraulic input shaft;

111-power output shaft; 112-input gear;

121-the first gear; 122-the second gear;

123-the third gear; 124-the fourth gear;

125-the fifth gear; 126-the sixth gear;

127-the seventh gear; 128-the eighth gear;

129-output gear; 131-first clutch;

132-the second clutch; 133-the third clutch;

134-the fourth clutch; 200-electric drive part;

210-the first electric generator; 220-the first coupling;

300-hydraulic drive part; 310-pump motor integrated machine;

311-the first safety valve; 312-the second coupling;

320-main pump; 321-second electric generator integrated machine;

330-oil tank; 331-filter;

340-the first two two-way electromagnetic reversing valve;

341-the second two-position two-way electromagnetic reversing valve;

342-hydraulic accumulator; 343-second safety valve;

344-pressure sensor; 350-three-position four-way electromagnetic reversing valve;

351-one-way valve; 500-work and steering hydraulic device.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

As shown in Figure 1, this embodiment provides an electro-hydraulic parallel drive construction machinery walking system, including a mechanical transmission part 100 and an electric drive part 200, a hydraulic drive part 300 and a walking execution part respectively connected to the mechanical transmission part 100 (not shown in the figure), wherein, the walking execution part is the wheel type running mechanism or crawler type running mechanism adopted by conventional engineering machinery (such as excavator, loader or wood grabber, etc.), not the present embodiment. The key point is not to be described in detail here.

The mechanical transmission part 100 is essentially a power coupling box, which includes a box body, an electric power input shaft 109, a hydraulic input shaft 110, a power output shaft 111, a first transmission shaft 101, and a second transmission shaft arranged in parallel to each other. 102, the third transmission shaft 103, the fourth transmission shaft 104, the fifth transmission shaft 105, the sixth transmission shaft 106 and the seventh transmission shaft 107, wherein the first transmission shaft 101 and the second transmission shaft 102 are arranged in a straight line in sequence, The third transmission shaft 103 and the hydraulic input shaft 110 are arranged in a straight line, the fourth transmission shaft 104 and the fifth transmission shaft 105 are arranged in a straight line, and the sixth transmission shaft 106 and the seventh transmission shaft 107 are arranged in a straight line. In addition, the power input shaft 109 is in transmission connection with the electric drive part 200 , the hydraulic input shaft 110 is in transmission connection with the hydraulic drive part 300 , and the power output shaft 111 is in transmission connection with the walking execution part. It should be noted that the above-mentioned input shaft or output shaft is only the name of the shaft, and does not mean that the shaft can only realize torque input or torque output. Under certain working conditions, the input shaft may realize the torque output function, and the output shaft may What may be realized is the torque input function, and similarly, the input gear and output gear mentioned below are just the nomenclature of the gears.

The power input shaft 109 is provided with an input gear 112, the first transmission shaft 101 is provided with a first gear 121 and a second gear 122 meshing with the input gear 112, and the first transmission shaft 101 and the second transmission shaft 102 pass through The first clutch 131 is connected, the second transmission shaft 102 is provided with the third gear 123, the third transmission shaft 103 and the hydraulic input shaft 110 are connected through the second clutch 132, and the third transmission shaft 103 is provided with the second The fourth gear 124 meshed with the gear 122, the fourth transmission shaft 104 is provided with a fifth gear 125 meshed with the second gear 122, that is, the second gear 122 meshes with the input gear 112, the fourth gear 124 and the fifth gear 125 at the same time ; The fourth transmission shaft 104 and the fifth transmission shaft 105 are connected by the third clutch 133, the fifth transmission shaft 105 is provided with the sixth gear 126 meshing with the third gear 123, and the sixth transmission shaft 106 is provided with the sixth transmission shaft 106 and The seventh gear 127 meshed with the first gear 121, and the sixth transmission shaft 106 and the seventh transmission shaft 107 are connected through the fourth clutch 134, and the seventh transmission shaft 107 is provided with an eighth gear meshed with the third gear 123 128, the power output shaft 111 is provided with an output gear 129 that meshes with the third gear 123, that is, the third gear 123 meshes with the output gear 129, the sixth gear 126 and the eighth gear 128 at the same time, and the number of teeth of each gear can be determined according to the actual situation. Need to set.

The first clutch 131, the third clutch 133 and the fourth clutch 134 correspond to the three speed ratio gears of the mechanical transmission part 100, and the connection or disconnection of the second clutch 132 determines whether the hydraulic drive part 300 is coupled with the electric drive part 200, Of course, the casing also needs to be provided with a three-speed transmission mechanism that cooperates with each clutch. The specific transmission mechanism is the same as that used in a conventional gearbox, and will not be described in detail here. It should be noted that the three-speed transmission is only one of the multi-speed transmissions used in existing construction machinery locks, and it can also be provided with more than three speeds according to actual needs.

The mechanical transmission part 100 provided in this embodiment cancels the directional clutch and the corresponding gear used in the traditional engineering machinery, and uses the first motor-generator integrated machine 210 and the pump-motor integrated machine 310 that will be mentioned below to be able to rotate forward and reverse. Features Realize the forward and reverse of the whole vehicle. This scheme improves the transmission efficiency of the whole vehicle, reduces the installation space of the external oil circuit, simplifies the electrical control and mechanical structure, greatly improves the reliability of the whole vehicle and reduces the cost.

The electro-hydraulic parallel drive construction machinery walking system provided in this embodiment has three driving modes: single walking motor drive, single variable pump/motor drive, walking motor and variable variable pump/motor compound drive. According to the conditions of the gear position and driving mode, the corresponding clutch is combined, and the power is output through the corresponding gear. Here, the three-speed transmission mechanism is used for illustration:

In the single travel motor drive mode, the electric drive part 200 is driven independently. When the gear is the first gear, the third clutch 133 is combined (that is, in a transmission connection state), and the other clutches are separated (that is, in a non-transmission connection state), and the electric drive The power provided by the part 200 is transmitted to the walking execution part through the electric power input shaft 109, the first transmission shaft 101, the fourth transmission shaft 104, the fifth transmission shaft 105, the second transmission shaft 102 and the power output shaft 111; In the second gear, the fourth clutch 134 is combined, and the other clutches are disengaged. The power provided by the electric drive part 200 passes through the electric input shaft 109, the first transmission shaft 101, the sixth transmission shaft 106, the seventh transmission shaft 107, and the second transmission shaft in sequence. 102 and the power output shaft 111 are transmitted to the walking execution part; when the gear position is the third gear, the first clutch 131 is combined, and the other clutches are separated, and the power provided by the electric drive part 200 is sequentially passed through the electric power input shaft 109, the first transmission shaft 101, The second transmission shaft 102 and the power output shaft 111 are transmitted to the walking execution part.

In the single-variable pump/motor drive mode, the hydraulic drive part 300 is driven independently. When the gear is in first gear, the second clutch 132 and the third clutch 133 are engaged, and the other clutches are disengaged. The power provided by the hydraulic drive part 300 is sequentially passed through the hydraulic drive The input shaft 110, the third transmission shaft 103, the first transmission shaft 101, the fourth transmission shaft 104, the fifth transmission shaft 105, the second transmission shaft 102 and the power output shaft 111 are transmitted to the walking execution part; when the gear position is the second gear , the second clutch 132 and the fourth clutch 134 are combined, the other clutches are separated, and the power provided by the hydraulic drive part 300 passes through the hydraulic input shaft 110, the third transmission shaft 103, the first transmission shaft 101, the sixth transmission shaft 106, the The seven transmission shafts 107, the second transmission shaft 102 and the power output shaft 111 are transmitted to the walking execution part; when the gear position is the third gear, the first clutch 131 and the second clutch 132 are combined, and the other clutches are separated, and the hydraulic drive part 300 provides The power is sequentially transmitted to the walking execution part through the hydraulic input shaft 110 , the third transmission shaft 103 , the first transmission shaft 101 , the second transmission shaft 102 and the power output shaft 111 .

In the travel motor and variable variable pump/motor compound drive mode, the electric drive part 200 and the hydraulic drive part 300 are driven simultaneously, and the action of the next clutch in each gear state is the same as in the single variable pump/motor drive mode, and the electric drive part The power of the 200 and the hydraulic driving part 300 is coupled at the second gear 122, and jointly drives the second gear 122 to rotate, and then transmits the power to the walking execution part along the corresponding transmission shaft.

The electric drive part 200 includes a first motor-generator integrated machine 210, a first motor control module (not shown in the figure) electrically connected to the first motor-generator integrated machine 210, and a charge-discharge battery ( (not shown in the figure), wherein, the rotating shaft of the first motor-generator 210 is connected to the power input shaft 109 through the first coupling 220, and the charge-discharge battery is preferably a lithium battery. It should be noted that the motor-generator integrated machines mentioned in this embodiment are motor/generators with both motor and generator functions, which can be purchased directly from the market.

The hydraulic drive part 300 includes a pump-motor integrated machine 310, a main pump 320, an oil tank 330 connected to the oil inlet of the main pump 320, a first two-position two-way electromagnetic reversing valve 340 connected to the oil outlet of the main pump 320, The three-position four-way electromagnetic reversing valve 350 communicated with the oil outlet of the first two-two two-way electromagnetic reversing valve 340, wherein the rotating shaft of the pump-motor integrated machine 310 is transmitted with the hydraulic input shaft 110 through the second coupling 312 connect. It should be noted that both the pump-motor integrated machine 310 and the main pump 320 are variable displacement pumps/motors that can simultaneously function as a variable displacement pump and a hydraulic motor, and can be purchased directly from the market.

The pump-motor integrated machine 310 has two oil ports, and when one of the oil ports was used as an oil inlet, the other oil port was used as an oil outlet. The two oil ports of the pump-motor integrated machine 310 are respectively connected with first safety valves 311 , and the oil return ports of each first safety valve 311 are connected with the oil tank 330 to recover hydraulic oil.

The main pump 320 is connected with a second integrated motor generator 321 , specifically, the rotating shaft of the second integrated motor generating machine 321 and the rotating shaft of the main pump 320 are coaxially connected through a coupling. The second motor-generator integrated machine 321 is electrically connected to a second motor control module (not shown in the figure), and the second motor control module is electrically connected to the charging and discharging battery, so that the reverse rotation of the main pump 320 can be used to drive the second motor generator. The all-in-one machine 321 generates power to realize energy storage. Preferably, the construction machinery walking system provided in this embodiment also includes a working and steering hydraulic device 500, the working and steering hydraulic device 500 is a hydraulic device used to drive the action and steering of the working unit on a conventional construction machine, not the hydraulic device of this embodiment. key points, which will not be detailed here. The oil outlet of the main pump 320 is connected to the working and steering hydraulic device 500 at the same time, that is, the conventional working and steering hydraulic device 500 is connected to the hydraulic drive part 300 in parallel, which can make full use of the surplus power of the working and turning hydraulic system 500, which is relatively Energy saving, specifically, due to the operation of construction machinery (such as loaders, etc.) and the operation of the steering hydraulic device 500, there is a large degree of overflow loss, and this part of the energy is consumed through the hydraulic accumulator 342 that will be mentioned below Recovery is performed for reuse of the hydraulic drive section 300 or the work and steering hydraulics 500 . In addition, the oil outlet of the main pump 320 is also connected with a first safety valve 311 , and the oil return port of the first safety valve 311 is also connected with the oil tank 330 to protect the main pump 320 .

A filter 331 is installed on the oil outlet of the oil tank 330 , and the oil inlet of the main pump 320 is connected with the oil tank 330 through the filter 331 , so as to prevent the pollutants mixed in the oil tank 330 from blocking the hydraulic channel. The oil inlet of the first two-position two-way electromagnetic reversing valve 340 is connected with the oil outlet of the main pump 320, because the oil outlet of the main pump 320 is also connected with the oil inlet of the first safety valve 311 and the working and steering hydraulic pressure. device 500 , therefore, the oil inlet of the first two-position two-way electromagnetic reversing valve 340 is also substantially connected with the oil inlet of the first safety valve 311 and the working and steering hydraulic device 500 .

Preferably, the oil outlet of the first two-position two-way electromagnetic reversing valve 340 is also connected with a second two-position two-way electromagnetic reversing valve 341, specifically, the oil outlet of the first two-position two-way electromagnetic reversing valve 340 The port is connected to the oil inlet port of the second two-position two-way electromagnetic reversing valve 341, and the oil outlet port of the second two-position two-way electromagnetic reversing valve 341 is respectively connected with a hydraulic accumulator 342 and a second safety valve 343. The oil return port of the second safety valve 343 is connected to the oil tank 330. In this way, when the construction machinery performs engineering operating conditions, its characteristics are low speed, high torque, and short time. The characteristics of this operating condition are the same as those of the hydraulic accumulator 342. The characteristics match well, and the hydraulic accumulator 9 can be used to supply oil to the pump-motor integrated machine 310 . In addition, in this embodiment, pressure sensors 344 are respectively connected to the oil outlets of the first 2/2-way electromagnetic directional valve 340 and the second 2/2-way electromagnetic directional valve 341 .

The three-position four-way electromagnetic directional valve 350 has an oil inlet, an oil return port and two oil outlets. The oil inlet of the three-position four-way electromagnetic directional valve 350 is connected to the first two-position two-way electromagnetic directional valve. The oil outlet of 340 is connected, and its essence is also connected with the oil inlet of the second two-position two-way electromagnetic reversing valve 341 at the same time, and the oil return port of the three-position four-way electromagnetic reversing valve 350 is connected with the oil tank 330, three-position four-way The two oil outlets of the electromagnetic reversing valve 350 are respectively connected to the two oil ports of the pump-motor integrated machine 310 through hydraulic oil pipes, and the two hydraulic oil pipes are respectively connected with oil supply pipes connected to the oil tank 330. Each oil supply pipe is provided with a check valve 351, so that the pump-motor integrated machine 310 can use the oil supply pipe to replenish oil and prevent backflow at the same time.

Preferably, in this embodiment, rotational speed sensors are installed on the rotating shafts of the first motor-generator integrated machine 210 and the pump-motor integrated machine 310, and the rotational speed sensor on the first motor-generator integrated machine 210 communicates with the first motor controller to intercept , the rotational speed sensor on the pump-motor integrated machine 310 is in communicative connection with the second motor controller, so that the corresponding motor controller can read the corresponding rotational speed and torque signals.

As mentioned above, the electro-hydraulic parallel drive construction machinery travel system provided in this embodiment has three driving modes: single travel motor drive, single variable pump/motor drive, travel motor and variable variable pump/motor compound drive. In /motor drive mode, the advantage of the variable pump motor integrated machine 310 matching the hydraulic accumulator 342 working at low speed and high torque is mainly responsible for the starting condition; in the single-travel motor drive mode, the first motor-generator integrated machine 210 has high efficiency. Advantages, mainly responsible for medium and low speed working conditions; in the travel motor and variable variable pump/motor compound drive mode, when responsible for high-speed working conditions, the output torque of the motor integrated machine 310 is used to compensate for the first motor-generator integrated machine 210 working in the constant power area due to the rotational speed To improve the problem of insufficient torque, when responsible for the execution of engineering operations (such as shoveling, stalling, etc.), use the output torque of the motor integrated machine 310 to assist the drive of the first motor-generator integrated machine 210, so that the first motor-generator integrated machine 210 The power level is greatly reduced. The specific control mode of each electromagnetic reversing valve is shown in the following table (the up and down and left and right azimuths in the table are the azimuths shown in Figure 1):

The electro-hydraulic parallel-driven construction machinery walking system provided in this embodiment uses a hydraulic accumulator-variable pump/motor to couple and drive the first motor-generator integrated machine 210 as a walking motor through the mechanical transmission part 100 (power coupling box) , and cancel the torque converter used in traditional construction machinery (such as loaders or excavators, etc.), and use the hydraulic motor (that is, the pump-motor integrated machine 310) to assist the electric motor (that is, the first The motor-generator integrated machine 210) outputs instantaneous large torque to meet the driving demand of extreme working conditions. The first motor-generator integrated machine 210 only needs to output an average torque; under negative load conditions, the hydraulic accumulator 342 and lithium battery are used The composed dual energy recovery unit realizes high-efficiency composite recovery of instantaneous high-power and stable low-power energy respectively.

Due to the complex and frequent working conditions of engineering machinery such as loaders and excavators, the braking frequency is high, while the traditional braking system adopts friction braking, and the life of the braking system is difficult to evaluate, resulting in hidden dangers in reliability. To solve This problem, preferably, in this embodiment provides a strategy that puts forward energy recovery in motor braking mode in priority, and energy recovery in variable displacement pump/motor braking mode, because the efficiency of the electrical circuit is higher than that of the hydraulic circuit, and at the same time, due to the braking The torque is large, the energy recovery effect is obvious, and the cruising ability of the vehicle is greatly improved. The specific method is as follows: combined with the SOC value of the lithium battery to judge the mode, when the SOC value is in a rechargeable state, use the first electric generator 210 and/or Or the second motor-generator integrated machine 321 outputs reverse torque, generates counter electromotive force under load, recycles and utilizes the energy generated by braking, and stores it in the lithium battery; when the SOC value is in a state of non-rechargeable or low charging efficiency, Using the variable pump/motor to work in the pump mode, the kinetic energy of the construction machinery is converted into pressure energy and stored in the hydraulic accumulator 342. In particular, when the vehicle is running at high speed and coasting, hydraulic energy recovery can be performed.

Specifically, in terms of energy recovery, it mainly consists of two parts: energy recovery of the working and steering hydraulic device 500 and regenerative braking. For the energy recovery of the working and steering hydraulic device 500, when there is recoverable energy in the working and steering hydraulic device 500, the whole machine controller of the engineering machinery (this controller is a conventional controller, but does not belong to a part of this embodiment) , of course, an independent controller can also be added in this embodiment, and the controller is communicated with the controller of the whole machine when in use) to the pressure of the oil outlet connected to the second two-position two-way electromagnetic reversing valve 341 The sensor 344 monitors to determine whether the hydraulic accumulator 342 is in a recoverable state. When the hydraulic accumulator 342 is in a recoverable state, the first two-position two-way electromagnetic reversing valve 340 works in the lower position, and the second two-position two-way The electromagnetic reversing valve 341 works in the right position to recover energy; for regenerative braking, the controller of the whole machine monitors the SOC value of the lithium battery, and when the SOC value is in a recyclable state, electrical energy recovery is performed. The whole machine control controller sends a torque mode request to the first motor-generator integrated machine 210 through the first motor controller, and the whole machine controller receives and processes the electronic brake pedal opening signal, and assigns a braking torque to it , when the SOC value is in a non-recoverable state or the recovery efficiency is low, the hydraulic energy recovery is performed, and the energy recovery is performed by the hydraulic accumulator 342. At this time, the pump-motor integrated machine 310 works in the pump mode, and the second two-position two-way The electromagnetic reversing valve 341 works at the right station, and the three-position four-way electromagnetic reversing valve 350 is at the lower station during forward braking and at the upper station during reverse braking. Hydraulic energy recovery, the control method is the same as above.

When the construction machinery walking system provided in this embodiment is applied to construction machinery, its working principle is as follows: use the complete machine controller of the construction machinery to control the feedback speed and feedback torque signals of the two motor controllers, the electronic throttle opening of the construction machinery Degree signal, brake pedal opening signal, pressure sensor pressure feedback signal of the construction machinery walking system, SOC signal of the battery management system, etc. The controller of the whole machine executes a pre-established control strategy, and sends control signals to the two motor controllers, three electromagnetic reversing valves, and four clutches in this embodiment, so as to control the first motor-generator integrated machine 210 and the pump-motor integrated machine 310 output power, spool displacement of three electromagnetic reversing valves, combination or disengagement of four clutches, and then realize various driving conditions and energy recovery methods.

The present invention has been described in detail above in conjunction with the accompanying drawings, but the embodiments of the present invention are not limited to the above-mentioned embodiments. Those skilled in the art can make various modifications to the present invention according to the prior art, and these all belong to the protection scope of the present invention .

Claims

An electro-hydraulic parallel-driven construction machinery walking system is characterized in that it includes a mechanical transmission part and an electric drive part, a hydraulic drive part, and a walking execution part respectively connected to the mechanical transmission part, and the mechanical transmission part includes mutual electric power input shaft, hydraulic input shaft, power output shaft, first transmission shaft, second transmission shaft, third transmission shaft, fourth transmission shaft, fifth transmission shaft, sixth transmission shaft and seventh transmission shaft arranged in parallel, The power input shaft is in transmission connection with the electric drive part, the hydraulic input shaft is in transmission connection with the hydraulic drive part, the power output shaft is in transmission connection with the walking execution part, and the power input shaft is provided with input gear, the first transmission shaft is provided with a first gear and a second gear meshed with the input gear, and the first transmission shaft and the second transmission shaft are connected through a first clutch, so The second transmission shaft is provided with a third gear, the third transmission shaft is connected to the hydraulic input shaft through a second clutch, and the third transmission shaft is provided with a gear that meshes with the second gear. The fourth gear, the fourth transmission shaft is provided with a fifth gear meshing with the second gear, and the fourth transmission shaft and the fifth transmission shaft are connected through a third clutch, the first The fifth transmission shaft is provided with a sixth gear meshed with the third gear, and the sixth transmission shaft is provided with a seventh gear meshed with the first gear, and the sixth transmission shaft and the first gear The seven transmission shafts are connected through the fourth clutch, and the seventh transmission shaft is provided with an eighth gear meshed with the third gear.
The construction machinery travel system driven by electro-hydraulic parallel drive according to claim 1, characterized in that, the electric drive part comprises a first motor-generator integrated machine and a first motor control module electromechanically connected with the first motor-generator integrated machine and a charge-discharge battery electrically connected to the first motor control module, the rotating shaft of the first integrated motor-generator is connected to the electric power input shaft through transmission.
The electro-hydraulic parallel-driven construction machinery walking system according to claim 2, wherein the hydraulic drive part includes a pump-motor integrated machine, a main pump, an oil tank connected to the oil inlet of the main pump, and the The first two-position two-way electromagnetic reversing valve connected to the oil outlet of the main pump, and the three-position four-way electromagnetic reversing valve connected with the oil outlet of the first two-two-way electromagnetic reversing valve, the The oil return port of the three-position four-way electromagnetic reversing valve is connected to the oil tank, and the two oil outlets of the three-position four-way electromagnetic reversing valve are respectively connected to the two oil outlets of the pump-motor integrated machine through hydraulic oil pipes. The ports are connected one by one, and the two hydraulic oil pipes are respectively connected with oil supply pipes connected to the oil tank, and the oil supply pipes are provided with check valves, and the rotating shaft of the pump-motor integrated machine is connected to the hydraulic input Shaft drive connection.
The electro-hydraulic parallel-driven construction machinery travel system according to claim 3, characterized in that the oil outlet of the main pump and the two oil ports of the pump-motor integrated machine are respectively connected with first safety valves, The oil return ports of each of the first safety valves are connected with the oil tank.
The construction machinery traveling system driven by electro-hydraulic parallel drive according to claim 3, characterized in that, the oil outlet of the first two-position two-way electromagnetic directional valve is also connected with a second two-position two-way electromagnetic directional valve , the oil outlet of the second two-position two-way electromagnetic reversing valve is respectively connected with a hydraulic accumulator and a second safety valve, and the oil return ports of the second safety valve are connected with the oil tank.
The construction machinery traveling system driven by electro-hydraulic parallel drive according to claim 5, characterized in that, the oil outlets of the first two-position two-way electromagnetic directional valve and the second two-position two-way electromagnetic directional valve Pressure sensors are respectively connected.
The construction machinery traveling system driven by electro-hydraulic parallel drive according to claim 3, further comprising working and steering hydraulic devices, and the oil outlet of the main pump is connected to the working and steering hydraulic devices at the same time.
The construction machinery traveling system driven by electro-hydraulic parallel drive according to claim 3, characterized in that, the main pump is connected with a second motor-generator integrated machine, and the second motor-generator integrated machine is electrically connected with a second motor control module, and the second motor control module is electrically connected to the charging and discharging battery.
The construction machinery traveling system driven by electro-hydraulic parallel drive according to claim 8, characterized in that, the charge-discharge battery is a lithium battery.
The construction machinery traveling system driven by electro-hydraulic parallel drive according to claim 3 is characterized in that a filter is installed on the oil outlet of the oil tank.