Pure electric loader-digger and torque distribution method

Abstract

According to the pure electric loader-digger and the torque distribution method, a traditional gearbox structure is abandoned, a front walking motor and a rear walking motor are adopted to drive a front axle and a rear axle respectively, and the front axle and the rear axle are driven according to the front axle load, the rear axle load, an accelerator signal and a brake pedal signal during running. Torque distribution of the front walking motor and the rear walking motor is carried out, slipping of front and rear wheels can be effectively avoided, four-wheel drive can be directly adopted at a high speed, and the driving force is improved.

Description

Technical Field

[0001] The invention relates to a pure electric excavator loader and a torque distribution method, belonging to the field of engineering machinery. Background Art

[0002] Backhoe loaders are multifunctional engineering machinery that can perform multiple operations such as digging, shoveling, transporting and leveling. At present, backhoe loaders use fuel engines as power sources, and the power is usually distributed to the front and rear axles through gearboxes and front and rear drive shafts. Since backhoe loaders have small front wheels and large rear wheels, the front wheel speed is faster than the rear wheel, and the front and rear wheels are prone to slipping when driving (whether at high speed or low speed). In order to ensure driving safety, they will become rear-wheel drive at high speeds, and the driving force of the rear drive is weaker. Summary of the invention

[0003] The present invention provides a pure electric backhoe loader and a torque distribution method, which solve the problems disclosed in the background technology.

[0004] According to one aspect of the present disclosure, a pure electric excavator loader is provided, including a front travel motor, a front travel motor controller, a rear travel motor, a rear travel motor controller, a vehicle controller, a battery controller and a power battery; The front travel motor drives the front axle, and the rear travel motor drives the rear axle; The vehicle controller distributes the torque of the front travel motor and the rear travel motor according to the front axle load, the rear axle load, the throttle signal and the brake pedal signal, and sends the distribution result of the front travel motor torque to the front travel motor controller, sends the distribution result of the rear travel motor torque to the rear travel motor controller, and sends the first trigger instruction to the battery controller; wherein the first trigger instruction is an instruction to trigger power-on after the torque distribution is completed; The battery controller controls the power supply line between the power battery and the front travel motor controller to be connected and supply power, and controls the power supply line between the power battery and the rear travel motor controller to be connected and supply power, in response to receiving the first trigger instruction; The front travel motor controller controls the front travel motor to drive the front axle according to the distribution result of the front travel motor torque in response to the power supply line of the power battery being connected and supplying power; The rear travel motor controller controls the rear travel motor to drive the rear axle according to the distribution result of the rear travel motor torque in response to the power supply line with the power battery being turned on and supplying power.

[0005] Further, it also includes a hydraulic motor and a hydraulic motor controller; The hydraulic motor is used to drive the hydraulic pump; The vehicle controller, in response to receiving the action signal from the working handle, sends the action signal to the hydraulic motor controller and sends the second trigger instruction to the battery controller; wherein the second trigger instruction is an instruction for triggering power on after receiving the action signal; The battery controller controls the power supply line between the power battery and the hydraulic motor controller to be turned on and supply power in response to receiving the second trigger instruction; The hydraulic motor controller controls the action of the hydraulic motor according to the action signal in response to the power supply line of the power battery being connected and supplying power.

[0006] Furthermore, the hydraulic pump includes a first pump port and a second pump port. The first pump port supplies oil to the working cylinder through the hydraulic valve, and the second pump port supplies oil to the brake through the steering valve.

[0007] Further, it also includes battery cooling equipment and battery heating equipment; The battery controller, in response to the power battery temperature being lower than a low temperature threshold, sends a battery heating instruction to the vehicle controller, and controls the power supply line between the power battery and the battery heating device to be turned on and supply power; in response to the power battery temperature being higher than a high temperature threshold, sends a battery cooling instruction to the vehicle controller, and controls the power supply line between the power battery and the battery cooling device to be turned on and supply power; The vehicle controller, in response to receiving the battery heating instruction, sends the battery heating instruction to the battery heating device; in response to receiving the battery cooling instruction, sends the battery cooling instruction to the battery cooling device; The battery heating device, in response to being connected to the power supply line of the power battery and supplying power, performs a heating action according to the battery heating instruction; The battery cooling device, in response to being connected to the power supply line of the power battery and supplying power, performs a cooling action according to the battery cooling instruction.

[0008] Furthermore, it also includes an environment cooling device and an environment heating device; The battery controller controls the power supply line between the power battery and the environment heating device to be turned on and supply power in response to receiving an externally triggered environment heating instruction; controls the power supply line between the power battery and the environment cooling device to be turned on and supply power in response to receiving an externally triggered environment cooling instruction; The vehicle controller, in response to receiving an externally triggered environment heating instruction, sends the environment heating instruction to the environment heating device; in response to receiving an externally triggered environment cooling instruction, sends the environment cooling instruction to the environment cooling device; The environment heating device, in response to being connected to the power supply line of the power battery and supplying power, performs a heating action according to the environment heating instruction; The environment cooling device, in response to the power supply line with the power battery being connected and supplying power, performs a cooling action according to the environment cooling instruction.

[0009] Furthermore, a DC / DC controller is also included; The vehicle controller, in response to receiving a power supply demand from a low-voltage electrical device, sends a power-drawing instruction to a battery controller and a DC / DC controller; The battery controller controls the power supply line between the power battery and the DC / DC controller to be turned on and supply power in response to receiving the power supply instruction; The DC / DC controller, in response to the power supply line with the power battery being turned on and supplying power, executes a power-taking action according to a power-taking instruction.

[0010] Furthermore, the power battery is powered by a high-voltage distribution box, and the battery controller controls the on-off of the power supply line by controlling the high-voltage distribution box.

[0011] According to another aspect of the present disclosure, a torque distribution method is provided, which is applicable to the above-mentioned pure electric backhoe loader, and the method includes: Calculate the requested vehicle torque based on the accelerator signal and the brake pedal signal; According to the requested vehicle torque, front axle load and rear axle load, the torque that may be allocated to the front travel motor and the torque that may be allocated to the rear travel motor are found from the first torque distribution table; wherein the first torque distribution table stores the corresponding front travel motor torque and front axle load, the corresponding rear travel motor torque and rear axle load, and the torque values ​​are not greater than the adhesion of the front tire and the rear tire to the ground; According to the torque that may be allocated to the front travel motor and the torque that may be allocated to the rear travel motor, the front travel motor torque and the rear travel motor torque with the smallest power sum are found from the second torque distribution table, and the front travel motor torque and the rear travel motor torque with the smallest power sum are taken as the final torque distribution result; wherein, the second torque distribution table stores the power sums corresponding to different torque distributions; the power sum is the sum of the front travel motor power and the rear travel motor power.

[0012] Furthermore, the first torque distribution table is pre-built, and the process of pre-building the first torque distribution table includes: Calculate the torque that may be allocated to the front travel motor and the torque that may be allocated to the rear travel motor according to the possible front axle load, the possible rear axle load, the external characteristic torque of the front travel motor, and the external characteristic torque of the rear travel motor, and construct a first torque allocation table according to the torque that may be allocated to the front travel motor and the torque that may be allocated to the rear travel motor; The formula for calculating the torque that may be allocated to the front travel motor and the torque that may be allocated to the rear travel motor is: ; Where T is the vehicle torque, T1 and T2 are the torques of the front and rear travel motors, m1 and m2 are the front axle load and rear axle load, k1 and k2 are relationship parameters, T 1峰 and T 2峰 The external characteristic torque of the front travel motor and the rear travel motor respectively.

[0013] Furthermore, the second torque distribution table is pre-built, and the process of pre-building the second torque distribution table includes: According to the efficiency maps of the front travel motor and the rear travel motor, the power sum under different torque distributions is calculated; and the second torque distribution table is constructed according to the power sum under different torque distributions.

[0014] The beneficial effects achieved by the present invention are as follows: the present invention abandons the traditional gearbox structure and adopts the front travel motor and the rear travel motor to drive the front axle and the rear axle respectively. When driving, the torque of the front travel motor and the rear travel motor is distributed according to the front axle load, the rear axle load, the throttle signal and the brake pedal signal, which can effectively avoid the front and rear wheels from slipping, and can directly adopt four-wheel drive at high speed to improve the driving force. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is the control module architecture diagram of a pure electric backhoe loader; Figure 2 is a flow chart of the torque distribution method; Figure 3 It is a schematic diagram of the external characteristic torque of the motor; Figure 4 This is the motor efficiency map. DETAILED DESCRIPTION

[0016] The following will be combined with the drawings in the embodiments of the present disclosure to clearly and completely describe the technical solutions in the embodiments of the present disclosure. It is obvious that the described embodiments are only part of the embodiments of the present disclosure, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present disclosure and its application or use. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present disclosure.

[0017] Unless specifically stated otherwise, the relative arrangement of components and steps, the numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present disclosure.

[0018] At the same time, it should be understood that for the convenience of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship.

[0019] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0020] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0021] It should be noted that similar symbols and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it does not require further discussion in subsequent figures.

[0022] At the same time, in the description of the embodiments of the present application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance. Therefore, the features defined as "first" or "second" may explicitly or implicitly include one or more features.

[0023] In order to solve the problems of front and rear wheel slippage and weak high-speed rear-wheel driving force in existing backhoe loaders, the present invention proposes a new pure electric backhoe loader, which specifically abandons the traditional gearbox structure, adopts front travel motor and rear travel motor to drive the front axle and rear axle respectively, and distributes the torque of the front travel motor and the rear travel motor during driving.

[0024] See also Figure 1 , Figure 1 This is a control module architecture diagram of a pure electric backhoe loader, which may include at least a front travel motor, a front travel motor controller, a rear travel motor, a rear travel motor controller, a vehicle controller, a battery controller and a power battery.

[0025] The front travel motor drives the front axle, and the rear travel motor drives the rear axle. It should be noted that the front travel motor and the rear travel motor are the driving modules of the whole vehicle. The front travel motor is mechanically connected to the front axle to drive the front axle. Both sides of the front axle are connected to tires. The rear travel motor is mechanically connected to the rear axle to drive the front axle. Both sides of the rear axle are connected to tires. There is no mechanical connection between the front travel motor and the rear travel motor.

[0026] The vehicle controller distributes the torque of the front travel motor and the rear travel motor according to the front axle load, the rear axle load, the throttle signal and the brake pedal signal, and sends the distribution result of the front travel motor torque to the front travel motor controller, sends the distribution result of the rear travel motor torque to the rear travel motor controller, and sends the first trigger instruction to the battery controller; wherein the first trigger instruction is an instruction to trigger power-on after the torque distribution is completed.

[0027] It should be noted that the vehicle controller is the brain of the vehicle and is an existing component. Its main function is to collect information, process the information, and then issue corresponding instructions.

[0028] Both the front axle load and the rear axle load can be obtained from load sensors, that is, the front axle load sensor and the rear axle load sensor are installed on the front axle and the rear axle respectively. The load sensor can communicate with the vehicle controller through the CAN bus to realize the transmission of the load.

[0029] The throttle signal is the signal generated by the driver stepping on the accelerator, and the brake pedal signal is the signal generated by the driver stepping on the brake pedal. The throttle and brake pedals also communicate with the vehicle controller through the CAN bus to realize the transmission of the throttle signal and the brake pedal signal.

[0030] Similarly, the front travel motor controller, the rear travel motor controller and the battery controller all communicate with the vehicle controller through the CAN bus, thereby realizing the transmission of the allocation results and the transmission of the first trigger instruction; wherein, the output torque of the travel motor can be controlled by the allocation result, and the first trigger instruction is merely a prompt signal, that is, a prompt signal prompting the battery controller to perform corresponding actions.

[0031] During driving, the vehicle controller distributes the torque of the front and rear travel motors according to the front axle load, rear axle load, throttle signal and brake pedal signal. Through torque distribution, the front and rear wheel slip can be effectively avoided. There is no risk in directly using four-wheel drive at high speeds, so there is no need to switch to rear-wheel drive, thereby improving the driving force at high speeds.

[0032] The battery controller, in response to receiving the first trigger instruction, controls the power supply line between the power battery and the front travel motor controller to be connected and supply power, and controls the power supply line between the power battery and the rear travel motor controller to be connected and supply power.

[0033] It should be noted that the battery controller and power battery are both essential equipment for electric vehicles. The battery controller interacts with the power battery, that is, it is connected through a low-voltage wiring harness to monitor the power battery voltage, power, temperature, etc., and can also control the power battery to supply power and charge. See also Figure 1 In some embodiments, the power battery can be powered by a high-voltage distribution box, and the battery controller controls the on-off of the power supply line by controlling the high-voltage distribution box. That is, the power battery can be connected to the high-voltage distribution box through a high-voltage cable, and the battery controller is connected to the high-voltage distribution box through a low-voltage wiring harness to control the high-voltage relay in the high-voltage distribution box, thereby controlling the on-off of the power supply line.

[0034] The front travel motor controller controls the front travel motor to drive the front axle according to the distribution result of the front travel motor torque in response to the power supply line with the power battery being connected and supplying power. The rear travel motor controller controls the rear travel motor to drive the rear axle according to the distribution result of the rear travel motor torque in response to the power supply line with the power battery being connected and supplying power.

[0035] It should be noted that see Figure 1 The high-voltage distribution box can connect the front travel motor controller and the rear travel motor controller through a high-voltage cable. When the power supply line is turned on and powered, that is, the high-voltage relay between the power battery and the travel motor controller is closed, and the power battery supplies power to the travel motor controller, the travel motor controller will control the movement of the travel motor according to the allocated torque.

[0036] It should be noted that, in addition to torque distribution control, the backhoe loader also performs hydraulic control in some embodiments, so the backhoe loader also includes a hydraulic motor and a hydraulic motor controller.

[0037] Similar to the travel motor, the hydraulic motor controller is connected to the vehicle controller through the CAN bus. The high-voltage distribution box can be connected to the hydraulic motor controller through a high-voltage cable. The hydraulic motor controller is connected to the hydraulic motor through a high-voltage wiring harness. The hydraulic motor is used to drive the hydraulic pump. The hydraulic pump includes a first pump port and a second pump port. The first pump port has a large displacement. The first pump port supplies oil to the working cylinders through a hydraulic valve, such as the boom cylinder, the dump bucket cylinder, the digging arm cylinder, the arm cylinder, the bucket cylinder, the slewing cylinder and the outrigger cylinder, etc. The second pump port has a small displacement. The second pump port supplies oil to the brake through a steering valve.

[0038] In hydraulic control: The vehicle controller, in response to receiving the action signal from the working handle, sends the action signal to the hydraulic motor controller and sends the second trigger instruction to the battery controller; wherein the second trigger instruction is an instruction for triggering power on after receiving the action signal; The battery controller controls the power supply line between the power battery and the hydraulic motor controller to be turned on and supply power in response to receiving the second trigger instruction; The hydraulic motor controller controls the action of the hydraulic motor according to the action signal in response to the power supply line of the power battery being connected and supplying power.

[0039] It should be noted that the working handle is similar to the throttle mentioned above, and is connected to the vehicle controller through the CAN bus. The movement of the working handle will send an action signal to the vehicle controller. After receiving the action signal, the vehicle controller sends the action signal to the hydraulic motor controller, and sends the second trigger instruction to the battery controller, which triggers the battery controller to control the high-voltage relay between the power battery and the hydraulic motor controller to close, and controls the power battery to supply power to the hydraulic motor controller. After the hydraulic motor controller is energized, it will control the movement of the hydraulic motor according to the action signal. Specifically, the hydraulic motor drives the hydraulic pump to pump the hydraulic oil to the hydraulic valve, steering valve, and brake. The hydraulic valve supplies oil to each hydraulic cylinder, and the steering valve supplies oil to the steering gear, thereby realizing the operation, steering and service braking of each cylinder.

[0040] It should be noted that in addition to torque distribution control and hydraulic control, the backhoe loader, in some embodiments, also performs some auxiliary controls, such as battery heating and cooling control, environmental heating and cooling control, and power supply control.

[0041] The structure of battery heating and cooling control may include at least a battery cooling device and a battery heating device; wherein, the battery cooling device may adopt a battery water cooling unit, and the battery heating device may adopt a battery water heater, both of which are connected to the high-voltage distribution box via a high-voltage cable, and are connected to the vehicle controller via a CAN bus.

[0042] In battery heating and cooling control: The battery controller, in response to the power battery temperature being lower than a low temperature threshold, sends a battery heating instruction to the vehicle controller, and controls the power supply line between the power battery and the battery heating device to be turned on and supply power; in response to the power battery temperature being higher than a high temperature threshold, sends a battery cooling instruction to the vehicle controller, and controls the power supply line between the power battery and the battery cooling device to be turned on and supply power; The vehicle controller, in response to receiving the battery heating instruction, sends the battery heating instruction to the battery heating device; in response to receiving the battery cooling instruction, sends the battery cooling instruction to the battery cooling device; The battery heating device, in response to being connected to the power supply line of the power battery and supplying power, performs a heating action according to a battery heating instruction.

[0043] The battery cooling device, in response to being connected to the power supply line of the power battery and supplying power, performs a cooling action according to the battery cooling instruction.

[0044] It should be noted that due to the interaction between the power battery and the battery controller, when the power battery temperature is less than 0°, a battery heating command will be sent to the vehicle controller, and the high-voltage relay between the power battery and the battery heating device will be controlled to close, and the power battery will be controlled to supply power to the battery heating device. After receiving the battery heating command, the vehicle controller will send the battery heating command to the battery heating device, and the battery heating device will perform the heating action according to the battery heating command after being powered on; conversely, when the power battery temperature is greater than 45°, a battery cooling command will be sent to the vehicle controller, and the high-voltage relay between the power battery and the battery cooling device will be controlled to close, and the power battery will be controlled to supply power to the battery cooling device. After receiving the battery cooling command, the vehicle controller will send the battery cooling command to the battery cooling device, and the battery cooling device will perform the cooling action according to the battery cooling command after being powered on.

[0045] The structure of the environmental heating and cooling control may at least include an environmental cooling device and an environmental heating device, wherein the environmental cooling device may be a refrigeration air conditioner, and the environmental heating device may be an air-heating PTC heater, both of which are connected to the high-voltage distribution box via a high-voltage cable, and are connected to the vehicle controller via the CAN bus. At the same time, since the environmental heating and cooling are based on external triggering, an air conditioning panel can be provided, and the air conditioning panel is connected to the vehicle controller and the battery controller via the CAN bus, that is, the environmental heating or cooling is triggered by the buttons in the air conditioning panel.

[0046] In ambient heating and cooling control: The battery controller controls the power supply line between the power battery and the environment heating device to be turned on and supply power in response to receiving an externally triggered environment heating instruction, i.e., triggering environment heating through the air conditioning panel; controls the power supply line between the power battery and the environment cooling device to be turned on and supply power in response to receiving an externally triggered environment cooling instruction, i.e., triggering environment cooling through the air conditioning panel; The vehicle controller, in response to receiving an externally triggered environment heating instruction, sends the environment heating instruction to the environment heating device; in response to receiving an externally triggered environment cooling instruction, sends the environment cooling instruction to the environment cooling device; The environment heating device, in response to the power supply line with the power battery being connected and supplying power, performs a heating action according to the environment heating instruction.

[0047] The environment cooling device, in response to the power supply line with the power battery being connected and supplying power, performs a cooling action according to the environment cooling instruction.

[0048] It should be noted that when the ambient temperature is low, such as 2°, the driver presses the heating button in the air-conditioning panel, which sends an ambient heating command to the vehicle controller and the battery controller. The battery controller receives the ambient heating command, controls the high-voltage relay between the power battery and the ambient heating device to close, and controls the power battery to supply power to the ambient heating device. The vehicle controller receives the ambient heating command, sends the ambient heating command to the ambient heating device, and when the ambient heating device is powered on, the ambient heating device performs the heating action according to the ambient heating command; conversely, when the ambient temperature is high, such as 30°, the driver presses the cooling button in the air-conditioning panel, which sends the ambient cooling command to the vehicle controller and the battery controller. The battery controller receives the ambient cooling command, controls the high-voltage relay between the power battery and the ambient cooling device to close, and controls the power battery to supply power to the ambient cooling device. The vehicle controller receives the ambient cooling command, sends the ambient cooling command to the ambient cooling device. When the ambient cooling device is powered on, the ambient cooling device performs the cooling action according to the ambient cooling command.

[0049] The power supply control structure includes at least a DC / DC controller, which is connected to a high-voltage distribution box via a high-voltage cable and to a vehicle controller via a CAN bus.

[0050] When taking power: The vehicle controller sends a power-drawing instruction to the battery controller and the DC / DC controller in response to receiving power supply requirements of low-voltage electrical equipment, such as the working handle, brake pedal, air conditioning panel, lead-acid battery, etc.; The battery controller controls the power supply line between the power battery and the DC / DC controller to be turned on and supply power in response to receiving the power supply instruction; The DC / DC controller, in response to the power supply line with the power battery being turned on and supplying power, executes a power-taking action according to a power-taking instruction.

[0051] It should be noted that the power here is drawn from the power battery through the DC / DC controller, which converts high voltage electricity into low voltage electricity to power the lead-acid battery and low-voltage electrical equipment. The vehicle controller receives the power supply demand of the low-voltage electrical equipment and sends a power-drawing instruction to the battery controller and the DC / DC controller. After receiving the power-drawing instruction, the battery controller controls the high-voltage relay between the power battery and the DC / DC controller to close, and controls the power battery to supply power to the DC / DC controller. After the DC / DC controller is powered on, it executes the power-drawing action according to the power-drawing instruction.

[0052] The above-mentioned pure electric excavator loader abandons the traditional gearbox structure and adopts the front travel motor and the rear travel motor to drive the front axle and the rear axle respectively, reducing environmental pollution. When driving, the torque of the front travel motor and the rear travel motor is distributed according to the front axle load, the rear axle load, the throttle signal and the brake pedal signal, which can effectively avoid the front and rear wheels from slipping, improve the stability, safety, efficiency and endurance of the whole vehicle, and can directly adopt four-wheel drive at high speed to improve driving force.

[0053] See also Figure 2 , Figure 1 : is a flow chart of a torque distribution method provided by an embodiment of the present disclosure. The method is applicable to the above-mentioned pure electric backhoe loader and can be executed by a vehicle controller. The method may at least include the following steps: Step 1: Calculate the requested vehicle torque based on the accelerator signal and the brake pedal signal.

[0054] The vehicle controller VCU obtains the electrical signals of the accelerator pedal and brake pedal opening in real time, and calculates the torque requested by the vehicle based on the changes in the electrical signals of the accelerator pedal and brake pedal.

[0055] Step 2, according to the requested vehicle torque, front axle load and rear axle load, find out the torque that may be allocated to the front travel motor and the torque that may be allocated to the rear travel motor from the first torque distribution table; wherein the first torque distribution table stores the corresponding front travel motor torque and front axle load, the corresponding rear travel motor torque and rear axle load, and the torque values ​​are not greater than the adhesion of the front tires and the rear tires to the ground.

[0056] It should be noted that the first torque distribution table is a pre-built table, which can be stored in the whole machine controller after being built. The process of pre-building the first torque distribution table may include: According to the possible front axle load, possible rear axle load, front travel motor external characteristic torque and rear travel motor external characteristic torque (see Figure 3 ), calculate the torque that may be allocated to the front travel motor and the torque that may be allocated to the rear travel motor, and construct a first torque distribution table according to the torque that may be allocated to the front travel motor and the torque that may be allocated to the rear travel motor. Since the torque value is not greater than the adhesion, the front travel motor torque and the rear travel motor torque are allocated according to the first torque distribution table, and the whole vehicle will not slip.

[0057] The formula for calculating the torque that can be distributed to the front travel motor and the torque that can be distributed to the rear travel motor is: ; Where T is the vehicle torque, T1 and T2 are the torques of the front and rear travel motors, m1 and m2 are the front axle loads and rear axle loads, k1 and k2 are relationship parameters, k1 is the relationship parameter between m1 and T1, k2 is the relationship parameter between m2 and T2, T 1峰 and T 2峰 The external characteristic torque of the front travel motor and the rear travel motor respectively.

[0058] Step 3, according to the torque that may be allocated to the front travel motor and the torque that may be allocated to the rear travel motor, find out the front travel motor torque and the rear travel motor torque when the power sum is the smallest from the second torque distribution table, and take the front travel motor torque and the rear travel motor torque when the power sum is the smallest as the final torque distribution result; wherein, the second torque distribution table stores the power sums corresponding to different torque distributions; the power sum is the sum of the front travel motor power and the rear travel motor power.

[0059] It should be noted that the second torque distribution table is a pre-built table, which can be stored in the whole machine controller after being built. The process of pre-building the second torque distribution table includes: according to the efficiency map of the front travel motor and the rear travel motor (see Figure 4 ), calculate the power sum under different torque distributions; and construct a second torque distribution table according to the power sum under different torque distributions.

[0060] The formula for determining the final torque distribution result can be expressed as: ; Where P is the power and are the efficiencies of the front and rear travel motors, i1 and i2 are the front axle speed ratio and rear axle speed ratio, n1 and n2 are the speeds of the front and rear travel motors, respectively.

[0061] The speed and torque of the front and rear travel motors are distributed in real time according to the second torque distribution table, so that the total efficiency of the motor is at a high efficiency point, thereby improving the endurance of the vehicle.

[0062] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A pure electric backhoe loader, characterized in that: Including front travel motor, front travel motor controller, rear travel motor, rear travel motor controller, vehicle controller, battery controller and power battery; The front travel motor drives the front axle, and the rear travel motor drives the rear axle; The vehicle controller distributes the torque of the front travel motor and the rear travel motor according to the front axle load, the rear axle load, the throttle signal and the brake pedal signal, and sends the distribution result of the front travel motor torque to the front travel motor controller, sends the distribution result of the rear travel motor torque to the rear travel motor controller, and sends the first trigger instruction to the battery controller; wherein the first trigger instruction is an instruction to trigger power-on after the torque distribution is completed; The battery controller controls the power supply line between the power battery and the front travel motor controller to be connected and supply power, and controls the power supply line between the power battery and the rear travel motor controller to be connected and supply power, in response to receiving the first trigger instruction; The front travel motor controller controls the front travel motor to drive the front axle according to the distribution result of the front travel motor torque in response to the power supply line of the power battery being connected and supplying power; The rear travel motor controller controls the rear travel motor to drive the rear axle according to the distribution result of the rear travel motor torque in response to the power supply line with the power battery being turned on and supplying power.

2. The pure electric backhoe loader according to claim 1, characterized in that: Also included are a hydraulic motor and a hydraulic motor controller; The hydraulic motor is used to drive the hydraulic pump; The vehicle controller, in response to receiving the action signal from the working handle, sends the action signal to the hydraulic motor controller and sends the second trigger instruction to the battery controller; wherein the second trigger instruction is an instruction for triggering power on after receiving the action signal; The battery controller controls the power supply line between the power battery and the hydraulic motor controller to be turned on and supply power in response to receiving the second trigger instruction; The hydraulic motor controller controls the action of the hydraulic motor according to the action signal in response to the power supply line of the power battery being connected and supplying power.

3. The pure electric backhoe loader according to claim 2, characterized in that: The hydraulic pump comprises a first pump port and a second pump port. The first pump port supplies oil to the working cylinder through the hydraulic valve, and the second pump port supplies oil to the brake through the steering valve.

4. The pure electric backhoe loader according to claim 1, characterized in that: It also includes battery cooling equipment and battery heating equipment; The battery controller, in response to the power battery temperature being lower than a low temperature threshold, sends a battery heating instruction to the vehicle controller, and controls the power supply line between the power battery and the battery heating device to be turned on and supply power; in response to the power battery temperature being higher than a high temperature threshold, sends a battery cooling instruction to the vehicle controller, and controls the power supply line between the power battery and the battery cooling device to be turned on and supply power; The vehicle controller, in response to receiving the battery heating instruction, sends the battery heating instruction to the battery heating device; in response to receiving the battery cooling instruction, sends the battery cooling instruction to the battery cooling device; The battery heating device, in response to being connected to the power supply line of the power battery and supplying power, performs a heating action according to the battery heating instruction; The battery cooling device, in response to being connected to the power supply line of the power battery and supplying power, performs a cooling action according to the battery cooling instruction.

5. The pure electric backhoe loader according to claim 1, characterized in that: It also includes environmental cooling equipment and environmental heating equipment; The battery controller controls the power supply line between the power battery and the environment heating device to be turned on and supply power in response to receiving an externally triggered environment heating instruction; In response to receiving an externally triggered environment cooling command, controlling the power supply line between the power battery and the environment cooling device to be turned on and supply power; The vehicle controller, in response to receiving an externally triggered environment heating instruction, sends the environment heating instruction to the environment heating device; in response to receiving an externally triggered environment cooling instruction, sends the environment cooling instruction to the environment cooling device; The environment heating device, in response to being connected to the power supply line of the power battery and supplying power, performs a heating action according to the environment heating instruction; The environment cooling device, in response to the power supply line with the power battery being connected and supplying power, performs a cooling action according to the environment cooling instruction.

6. The pure electric backhoe loader according to claim 1, characterized in that: It also includes a DC / DC controller; The vehicle controller, in response to receiving a power supply demand from a low-voltage electrical device, sends a power-drawing instruction to a battery controller and a DC / DC controller; The battery controller controls the power supply line between the power battery and the DC / DC controller to be turned on and supply power in response to receiving the power supply instruction; The DC / DC controller, in response to the power supply line with the power battery being turned on and supplying power, executes a power-taking action according to a power-taking instruction.

7. The pure electric backhoe loader according to any one of claims 1 to 6, characterized in that: The power battery is powered by a high-voltage distribution box, and the battery controller controls the on and off of the power supply line by controlling the high-voltage distribution box.

8. A torque distribution method, characterized in that: The method is applicable to the pure electric backhoe loader according to any one of claims 1 to 7, and the method comprises: Calculate the requested vehicle torque based on the accelerator signal and the brake pedal signal; According to the requested vehicle torque, front axle load and rear axle load, the torque that may be allocated to the front travel motor and the torque that may be allocated to the rear travel motor are found from the first torque distribution table; wherein the first torque distribution table stores the corresponding front travel motor torque and front axle load, the corresponding rear travel motor torque and rear axle load, and the torque values ​​are not greater than the adhesion of the front tire and the rear tire to the ground; According to the torque that may be allocated to the front travel motor and the torque that may be allocated to the rear travel motor, the front travel motor torque and the rear travel motor torque with the smallest power sum are found from the second torque distribution table, and the front travel motor torque and the rear travel motor torque with the smallest power sum are taken as the final torque distribution result; wherein, the second torque distribution table stores the power sums corresponding to different torque distributions; the power sum is the sum of the front travel motor power and the rear travel motor power.

9. The method according to claim 8, characterized in that The first torque distribution table is pre-built, and the process of pre-building the first torque distribution table includes: Calculate the torque that may be allocated to the front travel motor and the torque that may be allocated to the rear travel motor according to the possible front axle load, the possible rear axle load, the external characteristic torque of the front travel motor, and the external characteristic torque of the rear travel motor, and construct a first torque allocation table according to the torque that may be allocated to the front travel motor and the torque that may be allocated to the rear travel motor; The formula for calculating the torque that may be allocated to the front travel motor and the torque that may be allocated to the rear travel motor is: ； Where T is the vehicle torque, T1 and T2 are the torques of the front and rear travel motors, m1 and m2 are the front axle load and rear axle load, k1 and k2 are relationship parameters, T 1峰 and T 2峰 The external characteristic torque of the front travel motor and the rear travel motor respectively.

10. The method according to claim 8, characterized in that The second torque distribution table is pre-built, and the process of pre-building the second torque distribution table includes: According to the efficiency maps of the front travel motor and the rear travel motor, the power sum under different torque distributions is calculated; and the second torque distribution table is constructed according to the power sum under different torque distributions.

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