CN111823854A - Four-wheel drive system and vehicle - Google Patents

Abstract

The four-wheel drive system and vehicle of the present invention, a four-wheel drive system, includes an engine, a starting motor, a first clutch, a gearbox, a drive motor, a power take-off, an intermediate transmission shaft and a power coupler; the gearbox includes a speed change assembly and a front differential The engine is connected with the transmission assembly through the first clutch; the input end of the power take-off is connected with the front differential, and the output end of the power take-off is provided with a second clutch connected with the input end of the intermediate transmission shaft; the power coupler It includes a rear differential located at its power output end; the power input end of the power coupler is respectively connected with the drive motor and the output end of the intermediate transmission shaft. The engine or drive motor can be used for two-wheel drive, the engine can be used for four-wheel drive, and the engine and drive motor can be used for four-wheel drive. When the engine is four-wheel drive, the drive motor can supplement the rear axle driving torque, improve the off-road passability of the vehicle, and avoid overheating of the torque manager. The drive motor can work for too short a time, effectively improving vehicle economy and NVH performance.

Description

Four-wheel drive system and vehicle

technical field

The invention belongs to the field of new energy vehicles, and particularly relates to a four-wheel drive system and a vehicle.

Background technique

With the rapid improvement of people's living standards, the rapid development of automobile science and technology and the urgent need for survival and environmental protection, people have put forward higher requirements for automobiles, which are fun to drive, adaptable to multiple road conditions, sufficient power and economical Good high-performance vehicles have become the pursuit of consumers and an important breakthrough for automobile companies to occupy the high-end market.

For vehicles that are fun to drive and can adapt to multiple road conditions, after long-term exploration, people have proposed time-sharing four-wheel drive, full-time four-wheel drive and timely four-wheel drive; among them,

The time-sharing four-wheel drive generally only requires the driver to stop and manually switch to the four-wheel drive mode, and select the vehicle drive type by turning on and off the transfer case. It is easy to damage the four-wheel drive system;

The full-time four-wheel drive can better avoid the understeer of the front-wheel drive car and the over-steer of the rear-wheel drive car through calibration and distribute the output torque to the rear axle, and can improve the active safety and passability of the vehicle. However, the full-time four-wheel drive The strength requirements of the transmission system are high, the failure rate is high, and the fuel consumption is also relatively high;

The timely four-wheel drive system inherits the advantages of part-time four-wheel drive and full-time four-wheel drive through intelligent control, while making up for their shortcomings. Switching to the four-wheel drive mode through the four-wheel drive decision-making on low-adhesion, mud, sand and other attached roads can greatly improve the vehicle's power and off-road performance, making it more fun to drive; on paved roads such as urban roads, the four-wheel drive decision to switch to Two-wheel drive mode can improve vehicle economy while avoiding cornering braking and early tire wear. However, due to the arrangement of the power take-off, the four-wheel drive torque limit value needs to be set lower in order to protect the power take-off, resulting in the vehicle not being able to transmit proper driving torque to the rear axle, resulting in poor vehicle passability and easy torque management. Overheating, customers are prone to complain and jokingly call it a fake four-wheel drive problem.

In order to save energy, reduce emissions, protect the environment, and at the same time to ensure vehicle power, passability and consider technical feasibility, the hybrid four-wheel drive solution of P1 (or P2, or P3) motor + P4 motor is currently the most popular in mass production and research and development. However, practice shows that, due to the insufficient battery capacity of medium-mix and mild-mix four-wheel drive solutions, the vehicle cannot achieve vehicle energy saving under more severe working conditions, let alone Achieving four-wheel drive out of trouble, and the increase in the weight of additional new energy is even more detrimental to the improvement of vehicle energy saving and power performance; the strong-hybrid four-wheel drive solution requires large-capacity batteries, which is not only expensive, but also greatly increases the weight. It is also a huge test, which is not conducive to product competition.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a four-wheel drive system and a vehicle for the problems of insufficient four-wheel drive force and poor economy of the existing solution.

In order to solve the above technical problems, an embodiment of the present invention provides a four-wheel drive system, a four-wheel drive system including an engine, a starting motor, a first clutch, a gearbox and a drive motor, the starting motor is connected to the engine; and It includes a power take-off, an intermediate transmission shaft and a power coupler; the gearbox includes a speed change assembly and a front differential connected with the speed change assembly;

the engine is connected to the transmission assembly through the first clutch;

The input end of the power take-off is connected with the front differential, and the output end of the power take-off is provided with a second clutch;

the input end of the intermediate transmission shaft is connected with the second clutch;

The power coupler includes a rear differential at its power output end; the power input end of the power coupler is respectively connected with the drive motor and the output end of the intermediate transmission shaft.

Optionally, the power coupler further includes a third clutch, a torque manager and a fourth clutch;

the drive motor is connected to the third clutch;

The output end of the intermediate transmission shaft is connected with the torque manager;

Both the third clutch and the torque manager are connected to the rear differential through the fourth clutch.

Optionally, the power coupler further includes a planetary gear mechanism, a first brake and a second brake; the planetary gear mechanism includes a sun gear, a planet carrier and a ring gear;

The output end of the torque manager is connected with the sun gear, and the second brake is used for braking the sun gear;

the drive motor is connected with the ring gear through the third clutch, and the first brake is used for braking the ring gear;

The planet carrier is connected to the rear differential through the fourth clutch.

Optionally, the speed ratio of the power take-off is i, the gear ratio between the ring gear and the sun gear is k, and i=1+K.

Optionally, the power coupler further includes an intermediate gear, and the diameter of the intermediate gear is smaller than the diameter of the ring gear; the drive motor is located on the front side of the power coupler, and the third clutch is connected to the An intermediate gear is connected, and the intermediate gear meshes with the ring gear.

Optionally, the ring gear is located outside the torque manager, and the intermediate gear is located on a side of the ring gear facing away from the torque manager.

Optionally, the four-wheel drive system has an engine two-wheel drive mode, a pure electric two-wheel drive mode, an engine four-wheel drive mode, a hybrid four-wheel drive mode, and a super four-wheel drive mode;

Engage the first clutch, disengage the second clutch, disengage the fourth clutch, the launch motor on, the engine on, the torque manager off, the drive motor off to establish all The engine two-wheel drive mode;

The first clutch is disengaged, the second clutch is disengaged, the third clutch is engaged, the fourth clutch is engaged, the first brake is disengaged, the second brake is engaged, the starting motor does not work, so The engine does not work, the torque manager does not work, and the drive motor drives to establish the pure electric two-wheel drive mode;

The first clutch is engaged, the second clutch is engaged, the third clutch is disengaged, the fourth clutch is engaged, the first brake is engaged, the second brake is disengaged, the starting motor operates, the The engine is driven, the torque manager is activated, and the drive motor is deactivated to establish the engine four-wheel drive mode;

The first clutch is engaged, the second clutch is disengaged, the third clutch is engaged, the fourth clutch is engaged, the first brake is disengaged, the second brake is engaged, the starting motor operates, the The engine is driven, the torque manager is disabled, and the drive motor is enabled to establish the hybrid four-wheel drive mode;

The first clutch is engaged, the second clutch is engaged, the third clutch is engaged, the fourth clutch is engaged, the first brake is disengaged, the second brake is disengaged, the starting motor operates, the The engine drives, the torque manager operates, and the drive motor operates to establish the super four-wheel drive mode.

Optionally, the power take-off is provided in the gearbox.

Optionally, the drive gear shaft of the power take-off is connected to the housing of the front differential.

An embodiment of the present invention provides a vehicle, including a controller, a power battery, and a four-wheel drive system, where the four-wheel drive system is connected to the controller and the power battery.

In the four-wheel drive system and the vehicle provided by the embodiments of the present invention, the working state of the engine can be switched by controlling the working state of the first clutch. When the first clutch is engaged, the engine can output power to the front differential, and through the front differential By controlling the working state of the second clutch, the power transmission or interruption between the front differential and the intermediate transmission shaft can be controlled. When the first clutch and the second clutch are engaged at the same time, the power of the engine can be transmitted to the Rear wheel; the power of the drive motor is transmitted to the rear wheel through the power coupler, and even the intermediate drive shaft; thus, according to the power requirements of the vehicle, the engine can be selected to drive the front wheel alone or drive the front wheel and rear wheel at the same time, and the drive motor is selected to drive the rear wheel alone. Drive the rear wheels together with the engine, which has the advantages of conventional four-wheel drive and hybrid electric vehicles. The driving torque of the rear axle is supplemented by the drive motor, which prevents the traditional four-wheel drive vehicle from being unable to transmit the proper amount to the rear axle due to the limitation of the strength of the power take-off. The problem of driving torque, ensure that the rear axle has enough output torque to improve the off-road passability of the vehicle, avoid the damage of the four-wheel drive system caused by the overheating of the torque manager, and avoid the driving motor of the hybrid four-wheel drive vehicle due to insufficient battery capacity. The problem of too short can effectively improve vehicle economy and NVH performance.

Description of drawings

1 is a schematic structural diagram of a four-wheel drive system provided by an embodiment of the present invention;

Fig. 2 is a partial enlarged view of Fig. 1;

The reference numbers in the description are as follows:

1. Engine; 2. Starting motor; 3. The first clutch;

4. Gearbox; 41. Transmission assembly; 42. Front differential;

5. PTO; 51. Second clutch; 6. Intermediate drive shaft;

7. Power coupler; 71. Third clutch; 72. Torque manager; 73. Fourth clutch;

74, planetary gear mechanism; 741, sun gear; 742, planet carrier; 743, ring gear;

75, the first brake; 76, the second brake; 77, the intermediate gear; 78, the rear differential;

8. Drive motor;

10. Front wheel; 11. Left front axle; 12. Right front axle;

13. Rear wheel; 14. Left rear axle; 15. Right rear axle;

16. Power battery; 17. Controller.

Detailed ways

In order to make the technical problems, technical solutions and beneficial effects solved by the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention.

As shown in FIG. 1 , an embodiment of the present invention provides a four-wheel drive system, including an engine 1 , a starting motor 2 , a first clutch 3 , a gearbox 4 , a drive motor 8 , a power take-off 5 , an intermediate transmission shaft 6 and a power coupler 7 ; The gearbox 4 includes a transmission assembly 41 and a front differential 42 connected with the transmission assembly 41;

The starting motor 2 is connected to the engine 1;

The engine 1 is connected with the transmission assembly 41 through the first clutch 3;

The input end of the power take-off 5 is connected with the front differential 42, and the output end of the power take-off 5 is provided with a second clutch 51;

The input end of the intermediate transmission shaft 6 is connected with the second clutch 51;

The power coupler 7 includes a rear differential 78 at its power output end; the power input end of the power coupler 7 is connected to the drive motor 8 and the output end of the intermediate transmission shaft 6 respectively.

When in use, the power of the engine 1 is transmitted to the gearbox 4 through the first clutch 3, and drives the front wheels 10 through the front differential 42; the power of the front differential 42 is transmitted to the intermediate transmission shaft 6 through the power take-off 5, and The rear wheel 13 is driven by the power coupler 7; therefore, according to the power demand of the vehicle, the working state of the first clutch 3 and the second clutch 51 can be switched, and the engine 1 can be controlled to drive the front wheel 10 alone, or drive the front wheel 10 and the rear wheel 13 at the same time. The power of the drive motor 8 is transmitted to the power coupler 7, and drives the rear wheels 13 through the rear differential 78; of course, when the engine 1 cannot work and the power battery 16 has sufficient power, the rear wheel can also be driven by the drive motor 8 at the same time. The wheel 13 and the front wheel 10 ; when the engine 1 and the drive motor 8 transmit power to the rear wheel 13 at the same time, the power coupler 7 outputs the coupled power to the rear wheel 13 . Of course, the starter motor 2 can also transmit power to the front differential 42 when necessary.

Specifically, the front differential 42 distributes the power to the left front half shaft 11 and the right front half shaft 12, and drives the left and right front wheels 10 through the left front half shaft 11 and the right front half shaft 12, and the rear differential 78 distributes the power to the left and rear half shafts. The shaft 14 and the right rear half shaft 15 drive the left and right rear wheels 13 through the left rear half shaft 14 and the right rear half shaft 15 .

The four-wheel drive system provided by the embodiment of the present invention can realize the switching of the working state of the engine 1 by controlling the working state of the first clutch 3. When the first clutch 3 is engaged, the engine 1 can output power to the front differential 42, and through the The front differential 42 drives the front wheels 10; by controlling the working state of the second clutch 51, the power transmission or interruption between the front differential 42 and the intermediate transmission shaft 6 can be controlled. When the first clutch 3 and the second clutch 51 When engaged at the same time, the power of the engine 1 can be transmitted to the rear wheels 13; the power of the drive motor 8 is transmitted to the rear wheels 13 through the power coupler 7, and even the intermediate transmission shaft 6; so that the engine 1 can be selected to drive independently according to the power requirements of the vehicle The front wheel 10 or the front wheel 10 and the rear wheel 13 are driven at the same time, and the drive motor 8 is selected to drive the rear wheel 13 alone or together with the engine 1 to drive the rear wheel 13, which has the advantages of both conventional four-wheel drive and hybrid electric vehicles. Supplementing the driving torque of the rear axle, avoiding the problem that the traditional four-wheel drive vehicle cannot transmit proper driving torque to the rear axle due to the strength limitation of the power take-off 5, ensuring that the rear axle has enough output torque to improve the off-road passability of the vehicle, avoiding the torque manager 72 Overheating causes damage to the four-wheel drive system, and avoids the problem that the driving motor 8 can participate in the working time for too short due to insufficient battery capacity of the hybrid four-wheel drive vehicle, effectively improving vehicle economy and NVH (Noise, Vibration, Harshness) performance, suitable for for mild-hybrid four-wheel drive vehicles.

Specifically, the engine 1 is coaxially connected to the starter motor 2 through splines, which can realize coaxial torque coupling, so that the starter motor 2 can not only start the engine 1, but also participate in driving when necessary.

Specifically, the speed change assembly 41 can realize gear switching and deceleration and torque increase of the output of the engine 1 .

In one embodiment, as shown in FIG. 1 , the power coupler 7 further includes a third clutch 71 , a torque manager 72 and a fourth clutch 73 ;

The drive motor 8 is connected to the third clutch 71;

The output end of the intermediate transmission shaft 6 is connected with the torque manager 72;

The third clutch 71 and the torque manager 72 are both connected to the rear differential 78 through the fourth clutch 73 .

When the drive motor 8 does not need to work, the third clutch 71 is disengaged, which not only reduces the system load, but also protects the drive motor 8. The third clutch 71 can be engaged when the drive motor 8 is required to participate in driving or generating electricity; when the front wheel 10 is driven, disengage The second clutch 51 and the fourth clutch 73 are beneficial to reduce the system load and protect the torque manager 72; according to the power demand of the vehicle, the torque is distributed correspondingly through the torque manager 72, and the conventional four-wheel drive is realized through the engine 1, which can be used for Timely four-wheel drive, the front wheel 10 is driven by the engine 1 and the rear wheel 13 is driven by the drive motor 8 to realize a hybrid four-wheel drive, which can be used when the power take-off 5 cannot bear the load and the torque manager 72 is temporarily overheated, and the front wheel 10 is driven by the engine 1. Drive the rear wheel 13 with the rear wheel 13 and the drive motor 8 to achieve super four-wheel drive, which is suitable for when conventional four-wheel drive and hybrid four-wheel drive are not enough to get the vehicle out of trouble; Due to the limited space, the power take-off 5 with a small design margin cannot bear a slightly larger load, which improves the off-road passability, and avoids the torque manager 72 slipping for a long time to cause overheating, and it can also be used without increasing the torque limit value of the torque manager 72. Under the premise, the dynamic performance and passing performance of the whole vehicle are optimized.

In one embodiment, as shown in FIG. 1 and FIG. 2 , the power coupler 7 further includes a planetary gear mechanism 74 , a first brake 75 and a second brake 76 ; the planetary gear mechanism 74 includes a sun gear 741 , a planet carrier 742 and teeth. circle743;

The output end of the torque manager 72 is connected to the sun gear 741, and the second brake 76 is used for braking the sun gear 741;

The drive motor 8 is connected to the ring gear 743 through the third clutch 71, and the first brake 75 is used to brake the ring gear 743;

The carrier 742 is connected to the rear differential 78 through the fourth clutch 73 .

When only the driving motor 8 outputs power to the rear wheel 13, the second brake 76 brakes the sun gear 741, and when only the torque manager 72 outputs power to the rear wheel 13, the first brake 75 brakes the ring gear 743, so that the planetary gear mechanism 74 can be realized When shifting the output power of the drive motor 8 and the torque manager 72, and the drive motor 8 and the torque manager 72 output power to the rear differential 78 at the same time, the planetary gear mechanism 74 also plays the role of coupling power, which simplifies the structure. , reduce the system load, improve the economy, and ensure the stability of the transmission.

In one embodiment, the speed ratio of the power take-off 5 is i, the gear ratio between the ring gear 743 and the sun gear 741 is k, i=1+K, so as to avoid the damage of the torque manager 72 due to the difference in rotation speed, and extend the torque manager 72 service life.

In one embodiment, as shown in FIG. 1 , the power coupler 7 further includes an intermediate gear 77 , the drive motor 8 is located on the front side of the power coupler 7 , the third clutch 71 is connected with the intermediate gear 77 , and the intermediate gear 77 is connected with the ring gear 743 mesh, simple and compact structure, which is conducive to reducing the lateral size of the four-wheel drive system.

Specifically, the first brake 75 is connected to a clutch part of the third clutch 71 connected to the intermediate gear 77 , the intermediate gear 77 or the ring gear 743 ; in order to simplify the structure and reduce the volume of the power coupler 7 , the first brake is preferably The brake 75 is provided between the third clutch 71 and the intermediate gear 77, and is connected to a clutch portion of the third clutch 71 that is connected to the intermediate gear 77 (as shown in FIGS. 1 and 2).

In one embodiment, the diameter of the intermediate gear 77 is smaller than the diameter of the ring gear 743 , which can realize deceleration and torque increase when power is transmitted from the intermediate gear 77 to the ring gear 743 , and better match the power demand of the vehicle.

In one embodiment, as shown in FIGS. 1 and 2 , the ring gear 743 is located outside the torque manager 72 , and the intermediate gear 77 is located on the side of the ring gear 743 away from the torque manager 72 . The structure is more compact, which is conducive to reducing the volume.

In an embodiment, as shown in FIG. 1 , the power take-off 5 is arranged in the gearbox 4 , and the structure is simpler and more compact, which is beneficial to improve the bearing capacity.

Preferably, the drive gear shaft of the power take-off 5 is connected to the housing of the front differential 42, which is beneficial to increase the structural stability and increase the bearing capacity.

More preferably, the power take-off further includes a speed-increasing gear set, and the speed-increasing gear set is speed-increasingly connected to the housing of the front differential and the second clutch. That is, the power take-off not only realizes the torque reversal, but also realizes the acceleration and torque reduction of the power transmitted from the casing of the front differential to the second clutch.

In one embodiment, as shown in FIG. 1 , the starter motor 2 is located between the engine 1 and the gearbox 4 , which is beneficial to increase the compactness of the structure.

Specifically, the four-wheel drive system has five working modes, including engine two-wheel drive mode, pure electric two-wheel drive mode, engine four-wheel drive mode, hybrid four-wheel drive mode and super four-wheel drive mode, which are reflected in Table 1:

Table 1

(1) Engine two-wheel drive mode

The first clutch 3 is engaged, the second clutch 51 is disengaged, the fourth clutch 73 is disengaged, the starting motor 2 is activated, the engine 1 is activated, the torque manager 72 is deactivated, and the driving motor 8 is deactivated to establish the engine two-drive mode;

In this mode, the starting motor 2 starts the engine 1, and the power of the engine 1 is transmitted to the gearbox 4 through the first clutch 3. After the gearbox 4 shifts the speed, the power is transmitted to the left front axle 11 and the right front half through the front differential 42. The axle 12 drives the left and right front wheels 10, so that the front wheels 10 drive the vehicle, and the intermediate transmission shaft 6 is stationary, which effectively improves the NVH performance and economy of the vehicle, and is suitable for driving on good roads.

Since the second clutch 51 and the fourth clutch 73 are in the disengaged state, the structure of the power coupler 7 except the part of the fourth clutch 73 connected to the rear differential 78 and the intermediate transmission shaft 10 have no power to connect, the third Whether the clutch, the first brake and the second brake are engaged or not will not increase the load of the system, therefore, the working state of the third clutch, the first brake and the second brake may not be restricted.

(2) Pure electric two-drive mode

First clutch 3 disengaged, second clutch 51 disengaged, third clutch 71 engaged, fourth clutch 73 engaged, first brake 75 disengaged, second brake 76 engaged, starter motor 2 off, engine 1 off, torque manager 72 does not work, the drive motor 8 is driven to establish a pure electric two-drive mode;

In this mode, the power of the drive motor 8 is transmitted to the planetary gear mechanism 74 through the third clutch 71 , and is transmitted to the rear differential 78 through the fourth clutch 73 after being shifted by the planetary gear mechanism 74 , and the power is transmitted through the rear differential 78 To the left rear half shaft 14 and the right rear half shaft 15, it drives the left and right rear wheels 13, so that the rear wheels 13 drive the vehicle; it is suitable for low-load conditions such as low vehicle speed, slow start of the vehicle, and low-speed cruise. , to prevent the engine 1 from working in the low-efficiency area; coordinated control by the controller 17 avoids frequent starting of the engine 1 and idling of the intermediate drive shaft 6, effectively improving vehicle economy and reducing emissions.

(3) Engine four-wheel drive mode

The first clutch 3 is engaged, the second clutch 51 is engaged, the third clutch 71 is disengaged, the fourth clutch 73 is engaged, the first brake 75 is engaged, the second brake 76 is disengaged, the starting motor 2 is activated, the engine 1 is driven, and the torque manager 72 is activated , the drive motor 8 does not work to establish the engine four-wheel drive mode;

This mode is a conventional four-wheel drive mode. The starting motor 2 starts the engine 1, and the power of the engine 1 is transmitted to the gearbox 4 through the first clutch 3. After the gearbox 4 is shifted, the front differential 42 transmits a part of the power to the left front axle shaft. 11 and the right front half shaft 12, drive the left and right front wheels 10,

The front differential 42 transmits another part of the power to the intermediate drive shaft 6 through the power take-off 5, and then to the planetary gear mechanism 74 through the torque manager 72, and then transmitted to the rear differential through the fourth clutch 73 after the planetary gear mechanism 74 is shifted. The power is transmitted to the left rear half shaft 14 and the right rear half shaft 15 through the rear differential 78, and drives the left and right rear wheels 13, thereby realizing four-wheel drive; The magnitude of the pressing force of the torque manager 72 is determined intelligently such as stability characteristics, so as to realize the optimal torque input to the sun gear 741 .

In order to protect the torque limit value of the torque manager 72 of the power take-off 5 from being small, the rear axle does not have sufficient power to prevent the vehicle from slipping and there is a certain axle speed difference between the front and rear axles. The vehicle temporarily loses the four-wheel drive function of the engine, and further overheating will damage the four-wheel drive system. Therefore, in order to protect the four-wheel drive system, the engine four-wheel drive mode is suitable for timely four-wheel drive when the vehicle is driving on severe roads.

(4) Hybrid four-wheel drive mode

The first clutch 3 is engaged, the second clutch 51 is disengaged, the third clutch 71 is engaged, the fourth clutch 73 is engaged, the first brake 75 is disengaged, the second brake 76 is engaged, the starter motor 2 is operated, the engine 1 is driven, and the torque manager 72 is not work, the drive motor 8 works to establish a hybrid four-wheel drive mode;

In this mode, the starting motor 2 starts the engine 1, and the power of the engine 1 is transmitted to the gearbox 4 through the first clutch 3. After the gearbox 4 shifts the speed, the front differential 42 transmits the power to the left front axle 11 and the right front axle. 12. Drive the left and right front wheels 10,

The power of the drive motor 8 is transmitted to the planetary gear mechanism 74 through the third clutch 71 , and is transmitted to the rear differential 78 through the fourth clutch 73 after being shifted by the planetary gear mechanism 74 , and the power is transmitted to the left rear half through the rear differential 78 The shaft 14 and the right rear half shaft 15 drive the left and right rear wheels 13 to realize four-wheel drive.

At the same time, it has engine four-wheel drive and hybrid four-wheel drive mode, and the four-wheel drive performance of the whole vehicle is better; when the vehicle is driving on severe roads, in order to improve the off-road passability of the vehicle, the vehicle needs a four-wheel drive form, but due to the strength of the power take-off 5 and the When the torque manager 72 is temporarily overheated and the engine four-wheel drive mode cannot be used, the vehicle can be operated in the hybrid four-wheel drive mode to avoid temporary interruption of the four-drive power transmission; by optimizing the drive motor 8 and designing the transmission ratio of the power coupling mechanism, it can be temporarily The output is stronger than the rear axle power of the engine four-wheel drive, and the hybrid four-wheel drive mode is a reasonable supplement to the engine four-wheel drive, which effectively avoids the problem of the strength of the power take-off 5 and the failure of the torque manager 72.

(5) Super four-wheel drive mode

The first clutch 3 is engaged, the second clutch 51 is engaged, the third clutch 71 is engaged, the fourth clutch 73 is engaged, the first brake 75 is disengaged, the second brake 76 is disengaged, the starting motor 2 is operated, the engine 1 is driven, and the torque manager 72 is operated , the drive motor 8 works to establish the super four-wheel drive mode.

When the vehicle is driving on severe roads, and the above-mentioned four-wheel drive engine or hybrid four-wheel drive cannot get the vehicle out of trouble, the vehicle needs a momentary large driving torque to briefly drive out of the extremely bad road, and the vehicle can work in the super four-wheel drive mode.

In this mode, after the power output from the engine 1 is coupled with the power output from the starter motor 2, or after the starter motor 2 starts the engine 1, it stops working and the engine 1 outputs power alone, and is input to the gearbox 4 through the third clutch 71. The box 4 decelerates and increases the torque and then transmits it to the differential housing, and part of the power of the differential housing is transmitted to the left and right front wheels 10 through the left front half shaft 11 and the right front half shaft 12 respectively, so as to realize the driving of the front wheels 10;

Another part of the power of the differential housing is input to the second clutch 51 of the power take-off 5 through the power take-off 5 to increase the torque and reduce the torque, and then the front axle power is transmitted to the power coupler 7 through the intermediate transmission shaft 6 , and then intelligently determine the torque input to the sun gear 741 through the torque manager 72 in the power coupler 7, and output power from the planet carrier 742 after decelerating and increasing the torque through the planetary gear mechanism 74; The three clutches 71 transmit power to the intermediate gear 77 and through the intermediate gear 77 to the ring gear 743 meshing with it, and then output power from the planet carrier 742;

The planet carrier 742 gathers the power of the engine 1 and the drive motor 8, and finally outputs it to the rear differential 78 through the fourth clutch 73, and then distributes it to the left rear half shaft 14 and the right rear half shaft 15, and finally transmits it to the rear wheel 13, Realize rear wheel 13 drive.

This mode can realize the four-drive force coupling of conventional four-wheel drive and hybrid four-wheel drive, and can maximize the power performance and passing performance of the whole vehicle without increasing the torque limit value of the torque manager 72.

Of course, the four-wheel drive system of the present invention can also realize the normal working modes of vehicles with the engine 1 and the drive motor 8, such as driving charging and braking energy feedback. When charging is required, the power of the engine 1 is connected to the power transmission route of the drive motor 8. It is sufficient to reduce other loads as much as possible at the same time. When the braking energy is fed back, the power transmission route between the driving motor 8 and the wheel is connected and other loads are reduced as much as possible, which will not be repeated here.

If the planetary gear mechanism 74 is cancelled on the basis of the aforementioned scheme, for example, the power transmission between the torque manager 72 and the fourth clutch 73 and the drive motor 8 and the fourth clutch 73 are realized through two sets of parallel gears, the first brake 75 can be cancelled. and the setting of the second brake 76, the control of the first brake 75 and the second brake 76 can be correspondingly canceled when switching the working mode; if the third clutch 71 is canceled on the basis of the foregoing scheme, the control of the third clutch 71 is canceled. The control is sufficient. When the driving motor 8 does not participate in the work, it receives the power from the engine 1, and the rotating shaft of the driving motor 8 can idle; if the fourth clutch 73 is cancelled on the basis of the foregoing scheme, the control of the fourth clutch 73 can be cancelled. , when the drive motor 8 does not participate in the work, it receives the power from the engine 1 or the rear wheel 13, the rotating shaft of the drive motor 8 can idle, and the intermediate transmission shaft 6 receives the power from the rear wheel 13 and can idle; Then, the power routes of each working mode of the scheme are listed one by one.

Embodiments of the present invention further provide a vehicle, including a controller 17 , a power battery 16 and the four-wheel drive system described in any of the foregoing embodiments, where the four-wheel drive system is connected to the controller 17 and the power battery 16 .

Through the structural design of the electromechanical coupling four-wheel drive system and the coordinated control with the controller 17, the advantages of the traditional four-wheel drive and the hybrid four-wheel drive are skillfully combined, and the shortcomings of the two types of four-wheel drive are complemented at the same time, and the four-wheel drive performance of the whole vehicle is optimized. , make the vehicle fun to drive, adapt to multiple road conditions, have sufficient power, and effectively enhance the competitiveness of the vehicle.

Specifically, the engine 1 , the starting motor 2 , the drive motor 8 , the torque manager 72 , the first clutch 3 , the second clutch 51 , the third clutch 71 , the fourth clutch 73 , the first brake 75 and the second brake 76 are connected to The controller 17 is controlled by the controller 17 , and the starting motor 2 and the driving motor 8 are both connected to the power battery 16 . In FIG. 1 , the connection between the controller 17 and the elements controlled by the controller 17 is indicated by a dashed line, and the connection between the power battery 16 and the charging and consuming elements is indicated by a dashed-dotted line.

The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention shall be included in the protection scope of the present invention. Inside.

Claims (10)

1. A four-wheel drive system comprises an engine, a starting motor, a first clutch, a gearbox and a driving motor, wherein the starting motor is connected with the engine; it is characterized by also comprising a power takeoff, an intermediate transmission shaft and a power coupler; the gearbox comprises a speed change assembly and a front differential connected with the speed change assembly;

the engine is connected with the speed change assembly through the first clutch;

the input end of the power takeoff is connected with the front differential, and the output end of the power takeoff is provided with a second clutch;

the input end of the intermediate transmission shaft is connected with the second clutch;

the power coupler comprises a rear differential at a power output end thereof; and the power input end of the power coupler is respectively connected with the output ends of the driving motor and the intermediate transmission shaft.

2. The four-wheel drive system according to claim 1, wherein the power coupling further comprises a third clutch, a torque manager, and a fourth clutch;

the driving motor is connected to the third clutch;

the output end of the intermediate transmission shaft is connected with the torque manager;

the third clutch and the torque manager are both connected to the rear differential through the fourth clutch.

3. The four-wheel drive system according to claim 2, wherein the power coupling further comprises a planetary gear mechanism, a first brake and a second brake; the planetary gear mechanism comprises a sun gear, a planet carrier and a gear ring;

the output end of the torque manager is connected with the sun gear, and the second brake is used for braking the sun gear;

the driving motor is connected with the gear ring through the third clutch, and the first brake is used for braking the gear ring;

and the planet carrier is connected with the rear differential mechanism through the fourth clutch.

4. The four-wheel drive system according to claim 3, wherein the power take-off speed ratio is i, and the gear ratio of the ring gear to the sun gear is K, i ═ 1+ K.

5. The four-wheel drive system according to claim 4, wherein the power coupling further comprises an intermediate gear having a diameter smaller than a diameter of the ring gear; the driving motor is located on the front side of the power coupler, the third clutch is connected with the intermediate gear, and the intermediate gear is meshed with the gear ring.

6. The four-wheel drive system according to claim 5, wherein the ring gear is located on an outer side of the torque manager and the intermediate gear is located on a side of the ring gear facing away from the torque manager.

7. The four-wheel-drive system according to claim 3, wherein the four-wheel-drive system has a two-wheel-drive engine mode, a two-wheel-drive electric mode, a four-wheel-drive engine mode, a four-wheel-drive hybrid mode and a four-wheel-drive super mode;

engaging the first clutch, disengaging the second clutch, disengaging the fourth clutch, operating the starting motor, driving the engine, not operating the torque manager, and not operating the driving motor to establish the two-drive mode of the engine;

the first clutch is separated, the second clutch is separated, the third clutch is engaged, the fourth clutch is engaged, the first brake is separated, the second brake is engaged, the starting motor does not work, the engine does not work, the torque manager does not work, and the driving motor drives to establish the pure electric two-drive mode;

engaging the first clutch, engaging the second clutch, disengaging the third clutch, engaging the fourth clutch, engaging the first brake, disengaging the second brake, operating the launch motor, the engine drive, the torque manager, and the drive motor, to establish the engine four-drive mode;

engaging the first clutch, disengaging the second clutch, engaging the third clutch, engaging the fourth clutch, disengaging the first brake, engaging the second brake, operating the launch motor, the engine drive, the torque manager is not operational, and the drive motor is operational to establish the hybrid four-wheel drive mode;

engaging the first clutch, engaging the second clutch, engaging the third clutch, engaging the fourth clutch, disengaging the first brake, disengaging the second brake, the starting motor operates, the engine drives, the torque manager operates, and the drive motor operates to establish the super four-wheel drive mode.

8. The four-wheel drive system according to claim 1, wherein the power take-off is provided within the gearbox.

9. The four-wheel drive system according to claim 8, wherein a drive gear shaft of said power take-off is connected to a housing of said front differential.

10. A vehicle comprising a controller and a power battery, further comprising a four-wheel drive system according to any of claims 1-9, said four-wheel drive system being connected to said controller and said power battery.

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