Longitudinal dual-motor hybrid power system, control method and vehicle

Abstract

The longitudinally-arranged dual-motor hybrid power system comprises an engine and a hybrid power gearbox, the hybrid power gearbox comprises a first motor, a second motor and a dual clutch connected with the engine, the dual clutch is arranged to be used for controlling combination and separation between the engine and the first motor and between the engine and the second motor, and the second motor is a generator. According to the longitudinally-arranged dual-motor hybrid power system, three modes of pure electric driving, range extending and engine direct driving can be achieved through coordinated control over all the components; when the generator does not work, the generator can be decoupled from the engine and does not need to be reversely dragged, and dragging loss is effectively reduced. The invention further discloses a control method of the longitudinally-arranged dual-motor hybrid power system and a vehicle.

Description

Technical Field

[0001] The present invention belongs to the field of automobile technology, and in particular, relates to a longitudinal dual-motor hybrid power system, a control method and a vehicle. Background Art

[0002] With the advancement of battery and motor technology, as well as people's increased environmental awareness and focus on energy efficiency, hybrid vehicles have become a hot topic for automobile manufacturers and research and development institutions, and the market penetration of hybrid vehicles continues to grow. The current mainstream hybrid architectures include series architecture, parallel architecture, series-parallel architecture, and power split architecture. Among them, the series-parallel configuration is favored by the market due to its simple control, high fuel efficiency, and low cost.

[0003] For commercial vehicles such as pickup trucks, vans (light buses), and light trucks, longitudinal engine layouts are mostly used. However, the existing dual-motor series-parallel configurations are mostly transverse front-wheel drive, which is complex and not suitable for commercial vehicles. In the engine drive mode, the generator is in a power-drag state, and there is a large drag loss at high speeds.

[0004] It is desirable to provide an improved longitudinal dual-motor hybrid system, particularly with regard to how to reduce the impact of drag loss on vehicle performance. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a longitudinal dual-motor hybrid power system, the purpose of which is to reduce drag loss.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: a longitudinal dual-motor hybrid system, including an engine and a hybrid transmission, the hybrid transmission includes a first motor, a second motor and a dual clutch connected to the engine, the dual clutch is configured to control the connection and separation between the engine and the first motor and the second motor, and the second motor is a generator.

[0007] The dual clutch includes a first clutch and a second clutch, the first clutch and the second clutch are connected to the output end of the engine, the first clutch is connected to the first motor, and the second clutch is connected to the second motor.

[0008] The second motor is located between the first motor and the dual clutch.

[0009] The engine, the dual-clutch, the first motor and the second motor are coaxially arranged.

[0010] The hybrid transmission further includes a power transmission mechanism, which is configured to receive power from the engine and / or the first motor and transmit the received power to the differential assembly.

[0011] The power transmission mechanism comprises a first gear and a second gear, the first gear is a power input component of the power transmission mechanism, and the second gear is a power output component of the power transmission mechanism.

[0012] The first gear and the second gear are meshed.

[0013] The hybrid transmission also includes a housing, and the first motor, the second motor, the dual clutch and the power transmission mechanism are located in the housing.

[0014] The present invention also provides a control method for a longitudinal dual-motor hybrid power system, comprising:

[0015] When the longitudinal dual-motor hybrid power system operates in the engine direct drive mode, the dual clutch disconnects the power transmission between the engine and the second motor.

[0016] The present invention also provides a vehicle, comprising the longitudinal dual-motor hybrid power system.

[0017] The longitudinal dual-motor hybrid power system of the present invention can realize three modes of pure electric drive, extended range, and engine direct drive through coordinated control of various components; when the generator is not working, it can be decoupled from the engine without being reverse-dragged, effectively reducing drag losses. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the longitudinal dual-motor hybrid power system of the present invention;

[0019] Figure 2 It is a power roadmap of the longitudinal dual-motor hybrid power system of the present invention working in a pure electric drive mode;

[0020] Figure 3 It is a power route map of the longitudinal dual-motor hybrid power system of the present invention working in the extended-range mode;

[0021] Figure 4 It is a power route map of the longitudinal dual-motor hybrid power system of the present invention working in the engine direct drive mode;

[0022] Figure 5 is a flow chart for determining a vehicle driving mode;

[0023] Figure 6 is a flow chart of various working modes of the longitudinal dual-motor hybrid power system of the present invention;

[0024] The marks in the above figures are: 1, first motor; 2, second motor; 3, engine; 4, differential assembly; 5, wheel; 6, first gear; 7, second gear; 8, housing; C0, first clutch; C1, second clutch. DETAILED DESCRIPTION

[0025] To facilitate understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. Several embodiments of the present invention are given in the drawings, but the present invention can be implemented in different forms and is not limited to the embodiments described in the text. On the contrary, these embodiments are provided to make the content disclosed in the present invention more thorough and comprehensive.

[0026] It should be noted that when an element is referred to as being "fixed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower" and similar expressions used in this article are for illustrative purposes only.

[0027] It should be noted that, in the following embodiments, the “first”, “second” and “third” mentioned do not represent an absolute distinction in structure and / or function, nor do they represent a sequence of execution, but are merely for the convenience of description.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly connected by technicians in the technical field to which the present invention belongs. The terminology used in the specification of the present invention is for the purpose of describing specific embodiments and is not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0029] like Figures 1 to 6 As shown, the present invention provides a longitudinal dual-motor hybrid power system, including an engine 3 and a hybrid transmission, the hybrid transmission includes a first motor 1, a second motor 2 and a dual clutch connected to the engine 3, the dual clutch is configured to control the connection and separation between the engine 3 and the first motor 1 and the second motor 2, and the second motor 2 is a generator.

[0030] The dual clutch includes a first clutch C0 and a second clutch C1 . The first clutch C0 and the second clutch C1 are connected to the output end of the engine 3 . The first clutch C0 is connected to the first motor 1 , and the second clutch C1 is connected to the second motor 2 .

[0031] The second motor 2 is located between the first motor 1 and the dual clutch.

[0032] The engine 3 , the dual-clutch, the first motor 1 , and the second motor 2 are coaxially arranged.

[0033] The hybrid transmission further includes a power transmission mechanism, which is configured to receive power from the engine 3 and / or the first motor 1 and transmit the received power to the differential assembly 4 .

[0034] The power transmission mechanism comprises a first gear 6 and a second gear 7 , wherein the first gear 6 is a power input component of the power transmission mechanism, and the second gear 7 is a power output component of the power transmission mechanism.

[0035] The first gear 6 and the second gear 7 are meshed with each other.

[0036] The hybrid transmission further includes a housing 8 , and the first motor 1 , the second motor 2 , the dual clutch and the power transmission mechanism are located in the housing 8 .

[0037] The present invention also provides a control method for a longitudinal dual-motor hybrid power system, comprising:

[0038] When the longitudinal dual-motor hybrid power system operates in the direct drive mode of the engine 3 , the dual clutch disconnects the power transmission between the engine 3 and the second motor 2 .

[0039] The present invention also provides a vehicle, comprising the longitudinal dual-motor hybrid power system.

[0040] Example

[0041] First, as Figures 1 to 6 As shown, an embodiment of the present invention provides a longitudinal dual-motor hybrid power system, including an engine 3 and a hybrid transmission, the hybrid transmission includes a first motor 1, a second motor 2 and a dual clutch connected to the engine 3, the dual clutch is configured to control the engagement and separation between the engine 3 and the first motor 1 and the second motor 2, the first motor 1 is a drive motor, and the second motor 2 is a generator.

[0042] Specifically, if Figures 1 to 4 As shown, the dual clutch includes a first clutch C0 and a second clutch C1, the first clutch C0 and the second clutch C1 are connected to the output end of the engine 3, the first clutch C0 is connected to the first motor 1, and the second clutch C1 is connected to the second motor 2. The dual clutch is used to transmit the output power of the engine 3 and select different clutches (the first clutch C0 and the second clutch C1) for engagement and separation according to driving needs to achieve the switching of working modes and power transmission routes. The dual-motor four-wheel drive hybrid system can achieve three modes: pure electric mode, extended range mode, and engine direct drive mode, which can improve system efficiency and enhance motor utilization.

[0043] In the embodiment of the present invention, Figures 1 to 4 As shown, the second motor 2 is located between the first motor 1 and the dual clutch. The engine 3, the first motor 1 of the dual clutch and the second motor 2 are coaxially arranged, which can effectively reduce the Y-direction (the axis of the first motor 1 and the second motor 2 is parallel to the Y-direction, and the Y-direction points to the front or rear of the vehicle) size of the hybrid system, which is beneficial to the space layout of the vehicle.

[0044] In the embodiment of the present invention, when the second motor 2 is not working, it can be decoupled from the engine 3, and the second motor 2 does not need to be reverse-drag, which effectively reduces drag loss, improves system efficiency, and achieves the purpose of saving fuel and reducing consumption.

[0045] like Figures 1 to 4 As shown, the hybrid transmission further includes a power transmission mechanism, which is configured to receive power from the engine 3 and / or the first motor 1 and transmit the received power to the differential assembly 4 .

[0046] In the embodiment of the present invention, Figures 1 to 4 As shown, the power transmission mechanism includes a first gear 6 and a second gear 7, the first gear 6 is a power input component of the power transmission mechanism, the second gear 7 is a power output component of the power transmission mechanism, and the second gear 7 is connected to the differential assembly 4. The first clutch C0 is connected to the first motor 1 through the first transmission shaft, one end of the first transmission shaft is fixedly connected to the first clutch C0, the first transmission shaft is fixedly connected to the rotor of the first motor 1, and the other end of the first transmission shaft is coaxially fixedly connected to the first gear 6. The second clutch C1 is connected to the second motor 2 through the second transmission shaft, one end of the second transmission shaft is fixedly connected to the second clutch C1, and the other end of the second transmission shaft is fixedly connected to the rotor of the second motor 2. The second transmission shaft is a hollow shaft, and the first transmission shaft passes through the second transmission shaft to reduce space occupation and improve the compactness of the structure.

[0047] In the embodiment of the present invention, Figures 1 to 4 As shown, the first gear 6 and the second gear 7 are meshed. The first gear 6 and the second gear 7 transmit power through meshing, and the diameter of the first gear 6 is smaller than the diameter of the second gear 7. When the first gear 6 rotates, the second gear 7 is driven to rotate through the meshing action between the gears. This gear transmission method has the advantages of simple structure and high transmission efficiency.

[0048] The power transmission mechanism can receive power from the engine 3 and / or the first motor 1, which means that it can selectively use the power of the engine 3 or the motor as needed. This flexibility helps to improve the energy efficiency and power performance of the hybrid transmission.

[0049] In the embodiment of the present invention, Figures 1 to 4As shown, the hybrid transmission further includes a housing 8 , and the first motor 1 , the second motor 2 , the dual clutch and the power transmission mechanism are located inside the housing 8 .

[0050] like Figure 5 As shown, the longitudinal dual-motor hybrid system of the embodiment of the present invention also includes a controller, which controls the operation of the dual clutch, the first motor 1, the second motor 2 and the engine 3. The controller obtains information such as the vehicle speed, the wheel-end required torque and the power battery status to determine the vehicle's driving mode. Finally, the controller can control the start and stop of the engine 3 and distribute the driving torque of the engine 3 and the first motor 1 according to the driving mode.

[0051] The vehicle speed is obtained through the vehicle speed sensor and is an important basis for the controller to determine the current state of motion of the vehicle. The wheel-end demand torque is usually calculated based on the driver's acceleration request (such as the position of the accelerator pedal) and the current road conditions (such as slope, resistance, etc.), and is the key data for the controller to decide how much power to output to meet driving needs. The power battery status includes the battery power, temperature, etc., which is the basis for the controller to manage battery usage and charging strategies. The controller will decide when to start or stop the engine3 based on information such as vehicle speed, wheel-end demand torque and power battery status to optimize fuel economy and reduce emissions.

[0052] In the hybrid driving mode, the controller calculates and distributes the torque that the engine 3 and the first motor 1 should provide respectively to achieve the best power distribution and efficiency. This torque distribution can be adjusted in real time according to driving conditions to ensure that the vehicle can provide smooth and strong power output under various road conditions.

[0053] In the embodiment of the present invention, Figure 2 As shown, when the longitudinal dual-motor hybrid system operates in the pure electric drive mode, the engine 3 and the second motor 2 are stopped, the first clutch C0 and the second clutch C1 are in a disengaged state, the first motor 1 responds to the vehicle drive demand torque, and the first motor 1 generates a driving force to drive the vehicle. The power generated by the first motor 1 is transmitted to the differential assembly 4 through the power transmission mechanism.

[0054] When the first set condition is met, the longitudinal dual-motor hybrid system enters the pure electric drive mode. The first set condition includes that the vehicle speed is less than the calibration value, the remaining power of the power battery is greater than the calibration value, and the driving demand power is less than the target value, where the driving demand power = wheel end speed * wheel end demand torque.

[0055] In pure electric drive mode, in order to maximize the efficiency of battery use and reduce emissions, the vehicle usually runs in a lower speed range. Therefore, the controller will set a vehicle speed calibration value. When the actual vehicle speed is lower than this value, the system is more inclined to use the electric motor to provide power. In pure electric drive mode, in order to ensure that there is enough power to support the operation of the electric motor, the SOC of the power battery needs to be maintained at a relatively high level. Therefore, the controller will set an SOC calibration value. When the actual SOC is higher than this value, the system is qualified to enter the pure electric drive mode. The driving demand power is calculated based on the wheel end speed and the wheel end demand torque, which reflects the power required by the vehicle in the current state. In pure electric drive mode, in order to maintain the efficiency of battery use and extend battery life, the system usually limits the driving demand power to a relatively low target value. Therefore, when the actual driving demand power is less than this target value, the system is suitable for entering the pure electric drive mode.

[0056] In the embodiment of the present invention, Figure 3 As shown, when the longitudinal dual-motor hybrid system operates in the extended-range mode, the first clutch C0 is in a disengaged state, the second clutch C1 is in a coupled state, the engine 3 drives the second motor 2 to operate, the second motor 2 generates electricity, and the first motor 1 operates to provide driving force for driving the vehicle. The power generated by the first motor 1 is transmitted to the differential assembly 4 through the power transmission mechanism.

[0057] When the second setting condition is met, the longitudinal dual-motor hybrid system enters the extended range mode. The second setting condition includes that the vehicle speed is less than the calibration value, and the second setting condition also includes that the remaining power of the power battery is less than the calibration value or the wheel-end required power is greater than the calibration value.

[0058] When the remaining power (SOC) of the power battery is lower than a certain set calibration value, it means that the battery power is insufficient and cannot continue to support the long-term operation of the motor. At this time, the system needs to enter the extended range mode, and the engine 3 drives the generator to generate electricity to provide power for the motor, thereby extending the cruising range.

[0059] When the vehicle's wheel-end power demand (i.e., the power currently required by the vehicle) exceeds a certain set calibration value, it means that the driving demand is high and more power is needed to support it. In pure electric drive mode, if the power battery cannot provide enough power to meet this high power demand, the system also needs to enter the extended range mode and use the combination of the engine 3 and the generator to provide additional power.

[0060] When the second setting condition is met and the engine 3 start request is received, the first clutch C0 switches to the disengaged state and the second clutch C1 switches to the engaged state. After the second motor 2 increases the engine 3 speed to the target speed, the engine 3 injects fuel and ignites. After the engine 3 starts successfully, it enters the extended range mode. The controller controls the engine 3 and the generator power according to the vehicle's required power, and the first motor 1 responds to the vehicle's required torque.

[0061] The engine 3 and the generator work together to provide additional electrical energy to the drive motor, thereby extending the vehicle's cruising range. When the vehicle speed is low and the driving demand is high, the range-extending mode can more effectively utilize the energy of the engine 3, reducing energy consumption and emissions.

[0062] In the embodiment of the present invention, Figure 4 As shown, when the longitudinal dual-motor hybrid system operates in the engine direct drive mode, the first clutch C0 is in the engaged state, the second clutch C1 is in the disengaged state, the engine 3 switches to the torque control mode, the engine 3 provides the driving force for driving the vehicle, and the power generated by the engine 3 is sequentially transmitted to the differential assembly 4 through the first transmission shaft and the power transmission mechanism, the torque of the first motor 1 is used for torque compensation, and the first motor 1 adjusts the working point of the engine 3.

[0063] When the third setting condition is met, the longitudinal dual-motor hybrid system enters the engine direct drive mode. The third setting condition includes that the vehicle speed is greater than a calibrated value.

[0064] During the process of the longitudinal dual-motor hybrid system working in the extended-range mode, when the third setting condition is met and the engine 3 driving mode request is received, the second motor 2 unloads torque, that is, gradually reduces its output torque, and prepares for the engine 3 to take over the drive. The first clutch C0 switches to the disengaged state, disconnects the first motor 1 from the engine 3, and ensures that the engine 3 can be smoothly connected. The engine 3 begins to enter the speed control mode, and the target speed of the engine 3 is set to be synchronized with the current speed of the first clutch C0. When the speed difference between the engine 3 and the first clutch C0 is less than the set target value, the first clutch C0 switches to the engaged state, the engine 3 switches to the torque control mode, and the longitudinal dual-motor hybrid system enters the engine direct drive mode. The first clutch C0 switches to the engaged state, and the second clutch C1 switches to the disengaged state. At this time, the engine 3 and the first motor 1 jointly respond to the wheel-end drive torque.

[0065] In a second aspect, an embodiment of the present invention further provides a control method for a longitudinal dual-motor hybrid power system, comprising:

[0066] When the longitudinal dual-motor hybrid system operates in the engine direct drive mode, the dual clutch disconnects the power transmission between the engine 3 and the second motor 2.

[0067] In a third aspect, an embodiment of the present invention further provides a vehicle, including a longitudinal dual-motor hybrid power system of the above structure. The specific structure of the longitudinal dual-motor hybrid power system can be referred to Figures 1 to 6 Since the vehicle of the embodiment of the present invention includes the longitudinal dual-motor hybrid power system of the above embodiment, it has all the advantages of the longitudinal dual-motor hybrid power system.

[0068] The present invention is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned method. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A longitudinal dual-motor hybrid system, characterized in that: It includes an engine and a hybrid transmission, the hybrid transmission includes a first motor, a second motor and a dual clutch connected to the engine, the dual clutch is configured to control the connection and separation between the engine and the first motor and the second motor, and the second motor is a generator.

2. The longitudinal dual-motor hybrid system according to claim 1, characterized in that: The dual clutch includes a first clutch and a second clutch, the first clutch and the second clutch are connected to the output end of the engine, the first clutch is connected to the first motor, and the second clutch is connected to the second motor.

3. The longitudinal dual-motor hybrid system according to claim 1, characterized in that: The second motor is located between the first motor and the dual clutch.

4. The longitudinal dual-motor hybrid power system according to any one of claims 1 to 3, characterized in that: The engine, the dual-clutch, the first motor and the second motor are coaxially arranged.

5. The longitudinal dual-motor hybrid power system according to any one of claims 1 to 3, characterized in that: The hybrid transmission further includes a power transmission mechanism, which is configured to receive power from the engine and / or the first motor and transmit the received power to the differential assembly.

6. The longitudinal dual-motor hybrid power system according to claim 5, characterized in that: The power transmission mechanism comprises a first gear and a second gear, the first gear is a power input component of the power transmission mechanism, and the second gear is a power output component of the power transmission mechanism.

7. The longitudinal dual-motor hybrid power system according to claim 6, characterized in that: The first gear and the second gear are meshed.

8. The longitudinal dual-motor hybrid power system according to claim 5, characterized in that: The hybrid transmission also includes a housing, and the first motor, the second motor, the dual clutch and the power transmission mechanism are located in the housing.

9. The control method of a longitudinal dual-motor hybrid power system according to any one of claims 1 to 8, characterized in that: include: When the longitudinal dual-motor hybrid power system operates in the engine direct drive mode, the dual clutch disconnects the power transmission between the engine and the second motor.

10. A vehicle, characterized in that: It comprises a longitudinal dual-motor hybrid power system as described in any one of claims 1 to 8.

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