Four-wheel-drive hybrid electric vehicle

Abstract

The invention discloses a four-wheel-drive hybrid electric vehicle, and relates to the technical field of hybrid electric vehicles, the four-wheel-drive hybrid electric vehicle comprises an engine, a first motor, a battery, a second motor and a front axle planet row structure, the battery is electrically connected with the first motor through a first inverter and is electrically connected with the second motor through a second inverter, and the front axle planet row structure is electrically connected with the second motor through a second inverter; the front axle planet row structure comprises a sun gear, planet gears, a planet carrier, a first gear ring and a second gear ring, the sun gear is in transmission connection with the output end of the first motor, the planet gears are meshed with the sun gear and revolve around the sun gear, and the planet carrier is rotationally connected with the planet gears; the side, back on to the planet wheels, of the planet carrier is in transmission connection with the output end of the engine. According to the hybrid electric vehicle, under the pure electric driving mode, four-wheel drive can be achieved through the double motors, so that the good power performance of the vehicle under the pure electric driving mode is guaranteed, the structure of the front axle planet row of the vehicle is simple, the requirement for space arrangement is low, and the NVH performance of the vehicle is greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of hybrid vehicle, in particular to a four-wheel drive hybrid vehicle. Background Art

[0002] A hybrid electric vehicle (HEV) is a vehicle that combines an internal combustion engine and an electric motor, using two power sources to provide power to achieve higher fuel efficiency and lower emissions. During driving, hybrid vehicles can intelligently switch or use both the internal combustion engine and the electric motor according to driving conditions. For example, the electric motor is mainly used when starting and driving at low speeds, while the internal combustion engine or both work together when driving at high speeds or accelerating. In addition, hybrid vehicles are usually equipped with a kinetic energy recovery system to recover energy during braking or deceleration, convert it into electrical energy and store it in the battery, further enhancing energy utilization efficiency. This design not only improves the performance of the vehicle, but also helps reduce the impact on the environment. It is one of the important ways to achieve sustainable transportation.

[0003] With the shortage of energy, the aggravation of environmental problems and the policies promoted by the government, hybrid vehicles have received widespread attention for their long driving range and low energy consumption. With the continuous development of hybrid technology, major automobile manufacturers have launched their own four-wheel drive hybrid products.

[0004] The four-wheel drive hybrid power system not only has the characteristics of good passability and power of the four-wheel drive system, but also has the characteristics of low energy consumption and low pollutant emissions of the hybrid power system. The four-wheel drive hybrid power system can adjust the speed and torque of the motor according to the characteristics of the planetary gear to make the engine and motor work in a higher efficiency area.

[0005] In related technologies, in order to improve the power performance of hybrid vehicles in pure electric mode, car companies usually increase the specifications of the drive motor (ie, P3 motor) of the DHT (hybrid-specific transmission), adopt the configuration of P1 motor + P3 large motor, or increase the number of motors, such as adding a drive motor (ie, P4 motor) to the rear axle of a front-wheel drive hybrid vehicle, and adopt the configuration of P1 motor + P3 motor + P4 motor. However, increasing the drive motor or adding more drive motors will greatly increase the cost of DHT. Summary of the invention

[0006] The main purpose of the present invention is to propose a four-wheel drive hybrid vehicle, which aims to adopt a configuration with fewer motors and smaller motors, while optimizing the DHT cost and ensuring good power performance of the hybrid vehicle in pure electric mode.

[0007] To achieve the above object, the four-wheel drive hybrid vehicle proposed in the present invention includes an engine, a first motor, a battery, a second motor and a front axle planetary gear structure, wherein the battery is electrically connected to the first motor through a first inverter, and is electrically connected to the second motor through the second inverter;

[0008] The front axle planetary gear structure includes a sun gear, a plurality of planetary gears, a planet carrier, a first gear ring and a second gear ring, the sun gear is drivingly connected to the output end of the first motor, the plurality of planetary gears are all meshed with the sun gear and can revolve around the sun gear, the planet carrier is rotationally connected to the plurality of planetary gears, and the side of the planet carrier facing away from the plurality of planetary gears is drivingly connected to the output end of the engine;

[0009] Wherein, the output end of the second motor is connected to the rear wheel transmission, the second gear ring is connected to the front wheel transmission, a first synchronizer is arranged between the second gear ring and the first gear ring, and the first synchronizer has an idle state and a connected state. In the idle state, the first gear ring and the second gear ring are disconnected from each other; in the connected state, the first gear ring and the second gear ring rotate synchronously;

[0010] A second synchronizer is provided between the first motor and the sun gear, and the second synchronizer has a first connection state, a second connection state and an idle state. In the first connection state, the sun gear is fixed and the first motor stops; in the second connection state, the first motor rotates synchronously with the sun gear; in the idle state, the second ring gear is transmission-connected to the planetary carrier through the first ring gear, and the planetary carrier drives the sun gear to rotate to enable the first motor to generate electricity.

[0011] In one embodiment, the four-wheel drive hybrid vehicle further comprises a one-way clutch, the one-way clutch is arranged inside the engine and rotates synchronously with the crankshaft of the engine, and the one-way clutch is arranged close to the oil seal of the engine; or

[0012] The one-way clutch is arranged between the oil seal and the planet carrier.

[0013] In one embodiment, the four-wheel drive hybrid vehicle further includes a torque limiting vibration damper, which is disposed at an output end of the engine and between the engine and the planet carrier.

[0014] In one embodiment, the four-wheel drive hybrid vehicle has a pure electric drive mode, which includes a pure electric rear-wheel drive mode and a pure electric four-wheel drive mode. In the pure electric rear-wheel drive mode, the first synchronizer is in a neutral state, the second synchronizer is in a neutral state, the first motor and the engine are both stopped, and the second motor drives the rear wheels to travel;

[0015] In the pure electric four-wheel drive mode, the first synchronizer is in a connected state, the second synchronizer is in an idle state, the first motor drives the sun gear to rotate, the planetary carrier is locked, the sun gear drives the multiple planetary gears to rotate, the multiple planetary gears drive the first ring gear to drive the second ring gear to rotate to drive the front wheels to move, and the second motor drives the rear wheels to move.

[0016] In one embodiment, the four-wheel drive hybrid vehicle has an engine direct drive mode, which includes a first gear direct drive mode, a second gear direct drive mode, and a power split front drive mode. In the first gear direct drive mode, the first synchronizer is in a connected state, the second synchronizer is in a second connected state, the engine drives the planet carrier to rotate and drive the plurality of planetary gears to rotate and revolve around the sun gear, and the rotation of the sun gear drives the second ring gear to rotate to drive the front wheels to travel;

[0017] In the second gear direct drive mode, the first synchronizer is in a connected state, the second synchronizer is in a first connected state, the engine drives the planet carrier to rotate, driving the plurality of planetary gears to rotate and revolve around the sun gear, and the first ring gear rotates to drive the second ring gear to rotate to drive the front wheels to travel;

[0018] In the power-split front-wheel drive mode, the first synchronizer is in a connected state, the second synchronizer is in an idle state, the engine drives the planetary carrier to rotate, the planetary carrier drives the sun gear and the first ring gear to rotate respectively, the sun gear drives the first motor to rotate to generate electricity, and the first ring gear drives the second ring gear to rotate to drive the front wheels to travel.

[0019] In one embodiment, the four-wheel drive hybrid vehicle has a parallel four-wheel drive mode, and the parallel four-wheel drive mode includes a first-gear hybrid four-wheel drive mode, a second-gear hybrid four-wheel drive mode, and a power split four-wheel drive mode. In the first-gear hybrid four-wheel drive mode, the first synchronizer is in a connected state, the second synchronizer is in a second connected state, the engine drives the planet carrier to rotate and drive the plurality of planetary gears to rotate and revolve around the sun gear, the sun gear rotates and drives the second ring gear to rotate to drive the front wheels to travel, and the second motor drives the rear wheels to travel;

[0020] In the second-gear hybrid four-wheel drive mode, the first synchronizer is in a connected state, the second synchronizer is in a first connected state, the engine drives the planet carrier to rotate and drives the plurality of planetary gears to rotate and revolve around the sun gear, the first ring gear rotates and drives the second ring gear to rotate to drive the front wheels to travel, and the second motor drives the rear wheels to travel;

[0021] In the power-split four-wheel drive mode, the first synchronizer is in a connected state, the second synchronizer is in an idle state, the engine drives the planetary carrier to rotate, the planetary carrier drives the sun gear and the first ring gear to rotate respectively, the sun gear drives the first motor to rotate to generate electricity, the first ring gear drives the second ring gear to rotate to drive the front wheels, and the second motor drives the rear wheels to drive.

[0022] In one embodiment, the four-wheel drive hybrid vehicle has a parking power generation mode. In the parking power generation mode, the first synchronizer is in an idle state, the second synchronizer is in a second connection state, the engine runs to drive the planetary carrier to rotate, the planetary carrier drives the multiple planetary gears to rotate and revolve around the sun gear, and the rotation of the sun gear drives the first motor to rotate to generate electricity.

[0023] In one embodiment, the four-wheel drive hybrid vehicle has a driving power generation mode, which includes a direct drive power generation mode and a power split power generation mode. In the direct drive power generation mode, the first synchronizer is in a connected state, the second synchronizer is in a second connected state, the engine drives the planet carrier to rotate and drive the plurality of planetary gears to rotate and revolve around the sun gear, the sun gear rotates and drives the second ring gear to rotate to drive the front wheels to travel, the sun gear drives the first motor to rotate and generate electricity, and the engine and the first motor have the same rotation speed;

[0024] In the power splitting power generation mode, the first synchronizer is in a connected state, the second synchronizer is in an idle state, the engine drives the planetary carrier to rotate, the planetary carrier drives the sun gear and the first ring gear to rotate respectively, the sun gear drives the first motor to rotate to generate electricity, and the first ring gear drives the second ring gear to rotate to drive the front wheels to travel.

[0025] In one embodiment, the four-wheel drive hybrid vehicle has a series rear-wheel drive mode. In the series rear-wheel drive mode, the first synchronizer is in an idle state, the second synchronizer is in a second connection state, the engine runs to drive the planetary carrier to rotate, the planetary carrier drives the multiple planetary gears to rotate and revolve around the sun gear, the rotation of the sun gear drives the first motor to rotate to generate electricity, and the second motor drives the rear wheels to travel.

[0026] In one embodiment, the four-wheel drive hybrid vehicle has a kinetic energy recovery mode. In the kinetic energy recovery mode, the first synchronizer and the second synchronizer are both in an idle state, and the second motor generates electricity.

[0027] The technical solution of the present invention proposes a four-wheel drive hybrid vehicle, including an engine, a first motor, a battery, a second motor and a front axle planetary gear structure, the battery is electrically connected to the first motor through a first inverter, and is electrically connected to the second motor through a second inverter, and the overall front and rear dual motor layout of P1 motor (i.e., the first motor) + P4 motor (i.e., the second motor) is adopted, the front axle planetary gear structure includes a sun gear, a plurality of planetary gears, a planet carrier, a first gear ring and a second gear ring, the sun gear is drivingly connected to the output end of the first motor, the plurality of planetary gears are all meshed with the sun gear and can revolve around the sun gear, the planet carrier is rotationally connected to the plurality of planetary gears, the side of the planet carrier facing away from the plurality of planetary gears is drivingly connected to the output end of the engine, and the front axle planetary gear structure is The core transmission system in the four-wheel drive hybrid vehicle has a first synchronizer between the first ring gear and the second ring gear, and the first synchronizer has an empty state and a connected state. A second synchronizer is provided between the first motor and the sun gear, and the second synchronizer has a first connected state, a second connected state and an empty state. By controlling the switching of the first synchronizer and the second synchronizer between different states, the engine and the first motor can switch to different transmission connection relationships, thereby obtaining a variety of combination modes such as pure electric drive mode, engine direct drive mode, parallel four-wheel drive mode, parking power generation mode, driving power generation mode and series rear drive mode. In the pure electric drive mode, four-wheel drive can be achieved through dual motors, thereby ensuring good power performance of the vehicle in the pure electric mode.

[0028] Moreover, the four-wheel drive hybrid vehicle is provided with two motors in total and the front axle planetary gear structure is simple, which has low requirements for space layout and greatly improves the NVH performance of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0030] Figure 1 A schematic structural diagram of an embodiment of a four-wheel drive hybrid vehicle provided by the present invention;

[0031] Figure 2 for Figure 1 Structural schematic diagram of the planetary gear structure of the middle and front axle;

[0032] Figure 3 The vehicle status diagram of the four-wheel drive hybrid vehicle in each driving mode.

[0033] Description of Figure Numbers:

[0034] 1000. Four-wheel-drive hybrid vehicle; 1. Engine; 11. Front wheel; 111. Front differential; 12. Rear wheel; 121. Rear differential; 2. First motor; 21. First inverter; 22. Second synchronizer; 221. Housing; 222. Mating end; 23. First synchronizer; 3. Battery; 4. Second motor; 41. Second inverter; 5. Front axle planetary gear structure; 51. Sun gear; 52. Planetary gear; 53. Planet carrier; 54. First ring gear; 55. Second ring gear; 6. One-way clutch; 7. Torque limiting damper.

[0035] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0038] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0039] The present invention proposes a four-wheel drive hybrid vehicle, which aims to adopt a configuration with fewer motors and smaller motors, while optimizing the DHT cost and ensuring good power performance of the hybrid vehicle in pure electric mode. Figures 1 to 3This is a schematic diagram of a structure of an embodiment of a four-wheel drive hybrid vehicle provided by the present invention. It should be noted that: Figure 3 S1 represents the first synchronizer, and S2 represents the second synchronizer, wherein L shown in S2 represents the first connection state, R represents the second connection state, and "0" and "1" represent the disconnection and connection states respectively.

[0040] Please refer to Figures 1 to 3 The present invention provides a four-wheel drive hybrid vehicle, comprising an engine 1, a first motor 2, a battery 3, a second motor 4 and a front axle planetary gear structure 5, wherein the battery 3 is electrically connected to the first motor 2 via a first inverter 21, and is electrically connected to the second motor 4 via a second inverter 41;

[0041] The front axle planetary gear structure 5 includes a sun gear 51, a plurality of planetary gears 52, a planet carrier 53, a first gear ring 54 and a second gear ring 55. The sun gear 51 is drivingly connected to the output end of the first motor 2. The plurality of planetary gears 52 are all meshed with the sun gear 51 and can revolve around the sun gear 51. The planet carrier 53 is rotationally connected to the plurality of planetary gears 52. The side of the planet carrier 53 facing away from the plurality of planetary gears 52 is drivingly connected to the output end of the engine 1.

[0042] The output end of the second motor 4 is connected to the rear wheel 12, the second gear ring 55 is connected to the front wheel 11, and a first synchronizer 23 is arranged between the second gear ring 55 and the first gear ring 54. The first synchronizer 23 has an empty state and a connected state. In the empty state, the first gear ring 54 and the second gear ring 55 are disconnected from each other; in the connected state, the first gear ring 54 and the second gear ring 55 rotate synchronously.

[0043] A second synchronizer 22 is provided between the first motor 2 and the sun gear 51. The second synchronizer 22 has a first connection state, a second connection state and an idle state. In the first connection state, the sun gear 51 is fixed and the first motor 2 stops; in the second connection state, the first motor 2 rotates synchronously with the sun gear 51; in the idle state, the second ring gear 55 is transmission-connected to the planetary carrier 53 through the first ring gear 54, and the planetary carrier 53 drives the sun gear 51 to rotate to enable the first motor 2 to generate electricity.

[0044] The technical solution of the present invention proposes a four-wheel drive hybrid vehicle, including an engine 1, a first motor 2, a battery 3, a second motor 4 and a front axle planetary gear structure 5. The battery 3 is electrically connected to the first motor 2 through a first inverter 21, and is electrically connected to the second motor 4 through a second inverter 41. The overall front and rear dual motor layout of P1 motor (i.e., the first motor 2) + P4 motor (i.e., the second motor 4) is adopted. The front axle planetary gear structure 5 includes a sun gear 51, a plurality of planetary gears 52, a planet carrier 53, a first ring gear 54 and a second ring gear 55. The sun gear 51 is transmission-connected to the output end of the first motor 2, and the plurality of planetary gears 52 are all meshed with the sun gear 51 and can revolve around the sun gear 51. The planet carrier 53 is rotationally connected to the plurality of planetary gears 52, and the side of the planet carrier 53 facing away from the plurality of planetary gears 52 is transmission-connected to the output end of the engine 1. Next, the front axle planetary gear structure 5 is the core transmission system in the four-wheel drive hybrid vehicle. A first synchronizer 23 is arranged between the first ring gear 54 and the second ring gear 55. The first synchronizer 23 has an empty state and a connected state. A second synchronizer 22 is arranged between the first motor 2 and the sun gear 51. The second synchronizer 22 has a first connected state, a second connected state and an empty state. By controlling the switching of the first synchronizer 23 and the second synchronizer 22 between different states, the engine 1 and the first motor 2 can switch to different transmission connection relationships, thereby obtaining a pure electric drive mode, an engine 1 direct drive mode, a parallel four-wheel drive mode, a parking power generation mode, a driving power generation mode and a series rear drive mode and other combination modes. In the pure electric drive mode, four-wheel drive can be achieved by dual motors, thereby ensuring good power performance of the vehicle in the pure electric mode.

[0045] Moreover, the four-wheel drive hybrid vehicle is provided with two motors in total and the front axle planetary gear structure 5 is simple, which has low requirements for space arrangement and greatly improves the NVH performance of the vehicle.

[0046] In order to allow the left and right wheels of the vehicle to rotate at different speeds to ensure the speed difference between the inner and outer wheels when turning, the vehicle is provided with a front differential 111 and a rear differential 121 on the front axle and the rear axle respectively. The front differential 111 is driven by a transmission connection with the front axle planetary gear structure 5, and the rear differential 121 is driven by a transmission connection with the second motor 4. The differential can allow the left and right drive wheels to rotate at different speeds when the vehicle turns, thereby ensuring that there is no slip between the wheels and the ground, and improving the driving stability and safety. When the vehicle turns, the inner wheel travels a short distance, and the outer wheel travels a long distance. The differential automatically adjusts the speed difference between the wheels on both sides through the interaction of the planetary gears and the half-shaft gears, so that the vehicle can smoothly pass the curve.

[0047] When the vehicle switches from a low-adhesion road surface to a high-adhesion road surface during driving, the wheel end will be subjected to a large impact force due to the instantaneous increase in friction, and the impact force will be transmitted to the input shaft and the entire transmission system, and this impact force will cause great damage to the vehicle's transmission system. In order to reduce the impact of the wheel end on the input shaft when the vehicle switches from a low-adhesion road surface to a high-adhesion road surface, in one embodiment of the present invention, the vehicle is provided with a torque limiting damper 7 on the input shaft. For details, please refer to Figure 2 The torque limiter damper 7 (Torque Limiter Damper) uses disc springs, friction plate spline hubs, etc. in the transmission system to transmit the torque of the engine 1. When the torque is overloaded, it relies on slippage between the friction surfaces to prevent the transmission system from being overloaded and damaged. At the same time, an arc spring torsion damper is installed inside, which can attenuate the larger torsional vibration angular acceleration at the flywheel end of the engine 1 into a smaller angular acceleration at the input shaft of the gearbox, protect the planetary gear from damage during torsional impact, and prevent the NVH problems of the transmission system such as tooth knocking sound caused by the idling gears inside the gearbox. The damping disc structure arranged inside can attenuate the torsional vibration of the engine 1 and convert it into heat energy for dissipation, so as to protect the input shaft well when the low-adhesion road surface turns to the high-adhesion road surface.

[0048] Furthermore, the present invention also proposes an EV / HEV mode switching strategy applied to the hybrid electric vehicle. For the vehicle's power battery 3, the target SOC (State of Charge, which is the percentage of the current remaining power of the battery 3) refers to the SOC of the battery 3 in its optimal working state, the current SOC refers to the current SOC of the battery 3, and the difference SOC refers to the difference between the target SOC and the current SOC. Under the present switching strategy, when the difference SOC≤-10%, the speed n corresponding to the required vehicle speed V is obtained from the torque line Ti in the characteristic map of the second motor 4, and the actual torque (converted to the wheel side) is less than the wheel side required torque T requirement, considering factors such as the battery 3 temperature and the accessory power, the decision is made to use the first motor 2 + the second motor 4 dual-motor pure electric four-wheel drive mode; .... When the torque (converted to the wheel side) is greater than the wheel-side required torque Tdemand, the decision is made for the rear-wheel drive mode of the second motor 4; when -10% < difference SOC ≤ 10%, the speed n corresponding to the required vehicle speed V is obtained in the torque line Ti of the second motor 4 characteristic map, and when the actual torque (converted to the wheel side) is greater than the wheel-side required torque Tdemand, the decision is made for the rear-wheel drive mode of the second motor 4; when -10% < difference SOC ≤ 10%, the speed n corresponding to the required vehicle speed V is obtained in the torque line Ti of the second motor 4 characteristic map, and when the actual torque (converted to the wheel side) is less than the wheel-side required torque Tdemand, the decision is made for the HEV mode, and when the difference SOC > 10%, the decision is made for the HEV mode.

[0049] The hybrid vehicle proposed in this scheme includes a total of 7 power modes, namely pure electric drive mode, engine 1 direct drive mode, parallel four-wheel drive mode, parking power generation mode, driving power generation mode, series rear drive mode and kinetic energy recovery mode.

[0050] Among them, the pure electric drive mode is divided into pure electric rear-wheel drive mode and pure electric four-wheel drive mode. When the vehicle is in pure electric rear-wheel drive mode, please refer to Figure 3, the first synchronizer 23 is in the empty state, and the second synchronizer 22 is also in the empty state. When the first synchronizer 23 is in the empty state, the first gear ring 54 and the second gear ring 55 are in the disengaged state, that is, the movements of the first gear ring 54 and the second gear ring 55 are relatively independent, and there is no transmission relationship between the two. Therefore, when the first synchronizer 23 is in the empty state, the second gear ring 55 does not receive power input, and the front wheel 11 has no power drive and is in a powerless state. At this time, the second motor 4 located at the rear axle is in a working state, and drives the rear wheel 12 to rotate by driving the rear differential 121 to realize rear-wheel drive. The advantage of pure electric rear-wheel drive over pure electric front-wheel drive is that it provides better driving experience and handling performance. The rear wheel 12 is responsible for driving, making the vehicle more stable during acceleration and cornering, while improving the weight distribution of the vehicle and reducing the problem of understeering. In addition, the rear-wheel drive layout can better utilize the effect of the center of gravity shifting backward during acceleration, enhance grip and traction, provide more direct driving feedback, and achieve more efficient kinetic energy recovery during braking.

[0051] When the vehicle is in the pure electric four-wheel drive mode, at this time, the first synchronizer 23 is in a connected state, and the second synchronizer 22 is in an empty state. Since this mode is a pure electric mode, the engine 1 is in an inoperative state, and the output shaft of the engine 1 is connected to the planetary carrier 53. Due to the existence of the one-way clutch 6, the planetary carrier 53 is in a locked state in this mode. The first motor 2 drives the sun gear 51 to rotate, and the sun gear 51 drives the multiple planetary gears 52 to rotate. Since the planetary carrier 53 is locked, the planetary gears 52 do not revolve around the sun gear 51. The multiple planetary gears 52 rotate to drive the first gear ring 54 meshing therewith to rotate, thereby driving the second gear ring 55 to rotate to drive the front wheels 11 to travel. In this pure electric four-wheel drive mode, the four wheels of the vehicle have power input, so that the maximum torque output can be provided immediately, and the acceleration performance and driving experience can be enhanced; at the same time, the high efficiency of the motor helps to improve the energy utilization rate of the whole vehicle and reduce energy consumption. The four-wheel drive system ensures the vehicle's grip and driving stability under various road conditions, and improves driving safety. Compared with pure electric vehicles, hybrid four-wheel drive vehicles can effectively alleviate mileage anxiety, while reducing exhaust emissions and achieving more environmentally friendly travel.

[0052] In one embodiment, the vehicle has an engine 1 direct drive mode, which is further divided into a first gear direct drive mode, a second gear direct drive mode and a power split front drive mode. When the vehicle is in the first gear direct drive mode, the first synchronizer 23 is in a connected state, and the second synchronizer 22 is in a second connected state. For details, please refer to Figure 3 In this mode, the vehicle is in front-wheel drive mode and is driven by engine 1 to achieve front-wheel drive. Engine 1 drives the planetary carrier 53 to rotate, driving multiple planetary gears 52 to rotate and revolve around the sun gear 51. The rotation of the sun gear 51 drives the second ring gear 55 to rotate to drive the front wheels 11 to travel. At this time, the transmission speed is relatively small, which is a low gear.

[0053] When the vehicle is in the second gear direct drive mode, the first synchronizer 23 is in the connected state, the second synchronizer 22 is in the first connected state, the engine 1 drives the planetary carrier 53 to rotate and drive the multiple planetary gears 52 to rotate and revolve around the sun gear 51, the first ring gear 54 rotates to drive the second ring gear 55 to drive the front wheels 11 to travel, and the transmission speed is relatively large at this time, which is a high gear. The vehicle can reasonably switch between the two gears of the engine 1 direct drive through the driving computer according to the preset shift speed and vehicle speed to provide a better driving experience.

[0054] In the direct drive mode of the engine 1, the battery 3 can also be charged through the first motor 2, thereby achieving better fuel economy. When the vehicle is in the power split front drive mode, the first synchronizer 23 is in a connected state, the second synchronizer 22 is in an idle state, the engine 1 drives the planetary carrier 53 to rotate, the planetary carrier 53 drives the sun gear 51 and the first ring gear 54 to rotate respectively, the sun gear 51 drives the first motor 2 to rotate and generate electricity, and the first ring gear 54 drives the second ring gear 55 to rotate to drive the front wheel 11 to travel. The power split mode divides the power of the engine 1 into two branches, which are transmitted to the front wheels 11 to drive the car, thereby improving fuel economy and power. The two branches are mechanical power flow and electric power flow, wherein the mechanical power flow directly drives the wheels, and the electric power flow is converted into electrical energy by the rotation of the first motor 2 to generate electricity, and then converted into mechanical energy by the first motor 2 to drive the vehicle. The advantage of the power split system is that it can intelligently adjust the working state of the engine 1 and the electric motor according to the driving conditions, so that the engine 1 always works in the optimal efficiency range, thereby reducing fuel consumption and improving power performance. For example, when driving at low speed, engine 1 can maintain the high-efficiency speed range to generate electricity, while when driving at high speed, it can directly drive the wheels to reduce the loss in the energy conversion process. In addition, the power split system can be optimized according to different driving modes and working conditions, such as using pure electric mode in congested urban roads, and using engine 1 direct drive mode when driving at high speed, to achieve the best balance between fuel economy and power performance.

[0055] In one embodiment, the vehicle has a parallel four-wheel drive mode, which includes a first-gear hybrid four-wheel drive mode, a second-gear hybrid four-wheel drive mode, and a power-split four-wheel drive mode. When the vehicle is in the first-gear hybrid four-wheel drive mode, the first synchronizer 23 is in a connected state, and the second synchronizer 22 is in a second connected state. The engine 1 drives the planetary carrier 53 to rotate, driving the multiple planetary gears 52 to rotate and revolve around the sun gear 51. The rotation of the sun gear 51 drives the second ring gear 55 to rotate to drive the front wheels 11 to move, and the second motor 4 drives the rear wheels 12 to move. At this time, the vehicle is in a low-speed four-wheel drive.

[0056] When the vehicle is in the second gear hybrid four-wheel drive mode, the first synchronizer 23 is in a connected state, the second synchronizer 22 is in a first connected state, the engine 1 drives the planetary carrier 53 to rotate, driving the multiple planetary gears 52 to rotate and revolve around the sun gear 51, the first ring gear 54 rotates to drive the second ring gear 55 to rotate to drive the front wheels 11 to move, and the second motor 4 drives the rear wheels 12 to move. At this time, the vehicle is in high-speed four-wheel drive.

[0057] When the vehicle is in power-split four-wheel drive mode, the first synchronizer 23 is in a connected state, the second synchronizer 22 is in an idle state, the engine 1 drives the planetary carrier 53 to rotate, the planetary carrier 53 drives the sun gear 51 and the first ring gear 54 to rotate respectively, the sun gear 51 drives the first motor 2 to rotate to generate electricity, the first ring gear 54 drives the second ring gear 55 to rotate to drive the front wheels 11 to move, and the second motor 4 drives the rear wheels 12 to move. At this time, the front wheels 11 are driven by the engine 1, and part of the power of the engine 1 is used to drive the first motor 2 to rotate to charge the battery 3, and the rear wheels 12 are driven by the second motor 4, thereby realizing four-wheel drive.

[0058] In one embodiment, the four-wheel drive hybrid vehicle also has a parking power generation mode, the first synchronizer 23 is in an idle state, the second synchronizer 22 is in a second connection state, the engine 1 runs to drive the planetary carrier 53 to rotate, the planetary carrier 53 drives the multiple planetary gears 52 to rotate and revolve around the sun gear 51, and the rotation of the sun gear 51 drives the first motor 2 to rotate and generate electricity. In this mode, the engine 1 is in a working state, and the mechanical energy generated by its work is converted into electrical energy by the first motor 2 and stored in the battery 3, thereby achieving parking power generation.

[0059] In one embodiment, the four-wheel drive hybrid vehicle has a driving power generation mode, which includes a direct drive power generation mode and a power split power generation mode. In the direct drive power generation mode, the first synchronizer 23 is in a connected state, and the second synchronizer 22 is in a second connected state. The engine 1 drives the planetary carrier 53 to rotate and drive multiple planetary gears 52 to rotate and revolve around the sun gear 51. The rotation of the sun gear 51 drives the second ring gear 55 to rotate to drive the front wheels 11 to drive. The sun gear 51 drives the first motor 2 to rotate and generate electricity. The engine 1 and the first motor 2 have the same rotation speed, so that the engine 1 drives the wheels to drive and the first motor 2 to generate electricity at the same time.

[0060] In the power splitting power generation mode, the first synchronizer 23 is in a connected state, the second synchronizer 22 is in an idle state, the engine 1 drives the planetary carrier 53 to rotate, the planetary carrier 53 drives the sun gear 51 and the first ring gear 54 to rotate respectively, the sun gear 51 drives the first motor 2 to rotate to generate electricity, the first ring gear 54 drives the second ring gear 55 to rotate to drive the front wheels 11 to move, at this time the second motor 4 of the vehicle does not work, and only the front engine 1 is directly driven.

[0061] In one embodiment, the four-wheel drive hybrid vehicle has a series rear-wheel drive mode. In the series rear-wheel drive mode, the first synchronizer 23 is in an idle state, the second synchronizer 22 is in a second connection state, the engine 1 runs to drive the planetary carrier 53 to rotate, the planetary carrier 53 drives the multiple planetary gears 52 to rotate and revolve around the sun gear 51, the rotation of the sun gear 51 drives the first motor 2 to rotate and generate electricity, and the second motor 4 drives the rear wheels 12 to travel. At this time, the front wheels 11 have no power input and are only driven by the rear wheels 12.

[0062] The four-wheel drive hybrid vehicle proposed in this scheme also has a kinetic energy recovery mode. In the kinetic energy recovery mode, the first synchronizer 23 and the second synchronizer 22 are both in an idle state, and the second motor 4 generates electricity. In this mode, when the driver steps on the brake pedal or releases the accelerator pedal, the vehicle will recover energy through the reverse action of the motor. On long downhill sections, the kinetic energy recovery system can slow down the vehicle speed and recover energy at the same time.

[0063] The above description is only an exemplary embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A four-wheel drive hybrid vehicle, characterized in that: The invention comprises an engine, a first motor, a battery, a second motor and a front axle planetary gear structure, wherein the battery is electrically connected to the first motor through a first inverter, and is electrically connected to the second motor through the second inverter; The front axle planetary gear structure includes a sun gear, a plurality of planetary gears, a planet carrier, a first gear ring and a second gear ring, the sun gear is drivingly connected to the output end of the first motor, the plurality of planetary gears are all meshed with the sun gear and can revolve around the sun gear, the planet carrier is rotationally connected to the plurality of planetary gears, and the side of the planet carrier facing away from the plurality of planetary gears is drivingly connected to the output end of the engine; Wherein, the output end of the second motor is connected to the rear wheel transmission, the second gear ring is connected to the front wheel transmission, a first synchronizer is arranged between the second gear ring and the first gear ring, and the first synchronizer has an idle state and a connected state. In the idle state, the first gear ring and the second gear ring are disconnected from each other; in the connected state, the first gear ring and the second gear ring rotate synchronously; A second synchronizer is provided between the first motor and the sun gear, and the second synchronizer has a first connection state, a second connection state and an idle state. In the first connection state, the sun gear is fixed and the first motor stops; in the second connection state, the first motor rotates synchronously with the sun gear; in the idle state, the second ring gear is transmission-connected to the planetary carrier through the first ring gear, and the planetary carrier drives the sun gear to rotate to enable the first motor to generate electricity.

2. The four-wheel drive hybrid vehicle according to claim 1, characterized in that: The four-wheel drive hybrid vehicle further includes a one-way clutch, which is disposed inside the engine and rotates synchronously with the crankshaft of the engine, and the one-way clutch is disposed close to the oil seal of the engine; or The one-way clutch is arranged between the oil seal and the planet carrier.

3. The four-wheel drive hybrid vehicle according to claim 2, characterized in that: The four-wheel drive hybrid vehicle further comprises a torque limiting vibration damper, which is arranged at the output end of the engine and located between the engine and the planet carrier.

4. The four-wheel drive hybrid vehicle according to any one of claims 1 to 3, characterized in that: The four-wheel drive hybrid vehicle has a pure electric drive mode, which includes a pure electric rear-wheel drive mode and a pure electric four-wheel drive mode. In the pure electric rear-wheel drive mode, the first synchronizer is in a neutral state, the second synchronizer is in a neutral state, the first motor and the engine are both stopped, and the second motor drives the rear wheels to travel; In the pure electric four-wheel drive mode, the first synchronizer is in a connected state, the second synchronizer is in an idle state, the first motor drives the sun gear to rotate, the planetary carrier is locked, the sun gear drives the multiple planetary gears to rotate, the multiple planetary gears drive the first ring gear to drive the second ring gear to rotate to drive the front wheels to move, and the second motor drives the rear wheels to move.

5. The four-wheel drive hybrid vehicle according to any one of claims 1 to 3, characterized in that: The four-wheel drive hybrid vehicle has an engine direct drive mode, which includes a first gear direct drive mode, a second gear direct drive mode and a power split front drive mode. In the first gear direct drive mode, the first synchronizer is in a connected state, the second synchronizer is in a second connected state, the engine drives the planet carrier to rotate and drive the plurality of planetary gears to rotate and revolve around the sun gear, and the rotation of the sun gear drives the second ring gear to rotate to drive the front wheels to travel; In the second gear direct drive mode, the first synchronizer is in a connected state, the second synchronizer is in a first connected state, the engine drives the planet carrier to rotate, driving the plurality of planetary gears to rotate and revolve around the sun gear, and the first ring gear rotates to drive the second ring gear to rotate to drive the front wheels to travel; In the power-split front-wheel drive mode, the first synchronizer is in a connected state, the second synchronizer is in an idle state, the engine drives the planetary carrier to rotate, the planetary carrier drives the sun gear and the first ring gear to rotate respectively, the sun gear drives the first motor to rotate to generate electricity, and the first ring gear drives the second ring gear to rotate to drive the front wheels to travel.

6. The four-wheel drive hybrid vehicle according to any one of claims 1 to 3, characterized in that: The four-wheel drive hybrid vehicle has a parallel four-wheel drive mode, which includes a first-gear hybrid four-wheel drive mode, a second-gear hybrid four-wheel drive mode, and a power split four-wheel drive mode. In the first-gear hybrid four-wheel drive mode, the first synchronizer is in a connected state, the second synchronizer is in a second connected state, the engine drives the planet carrier to rotate and drive the plurality of planetary gears to rotate and revolve around the sun gear, the sun gear rotates and drives the second ring gear to rotate to drive the front wheels to travel, and the second motor drives the rear wheels to travel; In the second-gear hybrid four-wheel drive mode, the first synchronizer is in a connected state, the second synchronizer is in a first connected state, the engine drives the planet carrier to rotate and drives the plurality of planetary gears to rotate and revolve around the sun gear, the first ring gear rotates and drives the second ring gear to rotate to drive the front wheels to travel, and the second motor drives the rear wheels to travel; In the power-split four-wheel drive mode, the first synchronizer is in a connected state, the second synchronizer is in an idle state, the engine drives the planetary carrier to rotate, the planetary carrier drives the sun gear and the first ring gear to rotate respectively, the sun gear drives the first motor to rotate to generate electricity, the first ring gear drives the second ring gear to rotate to drive the front wheels, and the second motor drives the rear wheels to drive.

7. The four-wheel drive hybrid vehicle according to any one of claims 1 to 3, characterized in that: The four-wheel drive hybrid vehicle has a parking power generation mode. In the parking power generation mode, the first synchronizer is in an idle state, the second synchronizer is in a second connection state, the engine runs to drive the planetary carrier to rotate, the planetary carrier drives the multiple planetary gears to rotate and revolve around the sun gear, and the rotation of the sun gear drives the first motor to rotate to generate electricity.

8. The four-wheel drive hybrid vehicle according to any one of claims 1 to 3, characterized in that: The four-wheel drive hybrid vehicle has a driving power generation mode, which includes a direct drive power generation mode and a power split power generation mode. In the direct drive power generation mode, the first synchronizer is in a connected state, the second synchronizer is in a second connected state, the engine drives the planet carrier to rotate and drive the plurality of planetary gears to rotate and revolve around the sun gear, the sun gear rotates and drives the second gear ring to rotate to drive the front wheels to travel, the sun gear drives the first motor to rotate and generate electricity, and the engine and the first motor have the same rotation speed; In the power splitting power generation mode, the first synchronizer is in a connected state, the second synchronizer is in an idle state, the engine drives the planetary carrier to rotate, the planetary carrier drives the sun gear and the first ring gear to rotate respectively, the sun gear drives the first motor to rotate to generate electricity, and the first ring gear drives the second ring gear to rotate to drive the front wheels to travel.

9. The four-wheel drive hybrid vehicle according to any one of claims 1 to 3, characterized in that: The four-wheel drive hybrid vehicle has a series rear-wheel drive mode. In the series rear-wheel drive mode, the first synchronizer is in an idle state, the second synchronizer is in a second connection state, the engine runs to drive the planetary carrier to rotate, the planetary carrier drives the multiple planetary wheels to rotate and revolve around the sun gear, the rotation of the sun gear drives the first motor to rotate to generate electricity, and the second motor drives the rear wheels to travel.

10. The four-wheel drive hybrid vehicle according to any one of claims 1 to 3, characterized in that: The four-wheel drive hybrid vehicle has a kinetic energy recovery mode. In the kinetic energy recovery mode, the first synchronizer and the second synchronizer are both in an idle state, and the second motor generates electricity.

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