CN114834247A

CN114834247A - Drive disengagement method and mechanism and automobile

Info

Publication number: CN114834247A
Application number: CN202210446088.4A
Authority: CN
Inventors: 彭永金; 阮鸥; 徐循进; 黎明福; 卢雄; 施邹云
Original assignee: Zhejiang Geely Holding Group Co Ltd; Weirui Electric Automobile Technology Ningbo Co Ltd; Zhejiang Zeekr Intelligent Technology Co Ltd
Current assignee: Zhejiang Geely Holding Group Co Ltd; Weirui Electric Automobile Technology Ningbo Co Ltd; Zhejiang Zeekr Intelligent Technology Co Ltd
Priority date: 2022-04-26
Filing date: 2022-04-26
Publication date: 2022-08-02

Abstract

The invention provides a drive disengaging method, a drive disengaging mechanism and an automobile, wherein the drive disengaging method comprises the following steps: acquiring a torque demand; determining a target position of the disconnect mechanism based on the torque demand; acquiring the position of a synchronizer connected with an intermediate shaft, wherein the synchronizer is connected with a driving motor and the release mechanism; obtaining a current rotation angle of a release motor for supplying power to the release mechanism; determining a current position of the disconnect mechanism based on a synchronizer position and a current rotational angle of a disconnect motor; rotating the trip motor based on a current position and a target position of the trip mechanism; and adjusting the rotating speed and the torque output by the disengaging motor to the target position from the current position of the disengaging mechanism. The invention can realize the conversion of four-wheel drive and two-wheel drive states of the vehicle in different driving modes, different working conditions and different environments, thereby realizing the dynamic property of the four-wheel drive and the real-time economical property of the four-wheel drive.

Description

Drive disengagement method and mechanism and automobile

Technical Field

The invention relates to the technical field of automobiles, in particular to a drive disengaging method and mechanism and an automobile.

Background

The power driving system is used as a power output core component of the pure electric vehicle, and has important influence on the performance of the pure electric vehicle. The existing domestic and foreign pure electric vehicle power driving system mainly adopts two-wheel driving, and along with diversification of requirements of consumers on power configuration of pure electric vehicles, the four-wheel driving system is gradually applied to the pure electric vehicles. Compared with a traditional two-drive pure electric vehicle, the four-drive pure electric vehicle has great improvement on the aspects of dynamic property and operation stability, but still has disadvantages in the aspect of economy.

Disclosure of Invention

The invention aims to provide a drive disengaging method and mechanism for a pure electric four-wheel drive vehicle type, which has lower structural cost, can meet four-wheel drive power performance and can realize two-wheel drive economy.

The invention firstly provides a drive disengaging method for a pure electric four-wheel drive vehicle, which comprises the following steps: acquiring a torque demand; determining a target position of the disconnect mechanism based on the torque demand; acquiring the position of a synchronizer connected with an intermediate shaft, wherein the synchronizer is connected with a driving motor and the release mechanism; obtaining a current rotation angle of a release motor for supplying power to the release mechanism; determining a current position of the disconnect mechanism based on a synchronizer position and a current rotational angle of a disconnect motor; rotating the trip motor based on a current position and a target position of the trip mechanism; and adjusting the rotating speed and the torque output by the disengaging motor to the target position from the current position of the disengaging mechanism.

Further, the step of adjusting the release mechanism from the current position to the target position by the rotation speed and the torque output by the release motor comprises: the rotating speed output by the disengaging motor is reduced in a multi-stage mode, and the output torque is amplified in a multi-stage mode; and adjusting the disengaging mechanism from the current position to the target position by the multi-stage reduced rotating speed and the multi-stage amplified torque.

Further, the step of determining the current position of the disengagement mechanism based on the synchronizer position and the current rotation angle of the disengagement motor is preceded by the step of: and acquiring the position of the synchronizer based on a position sensor which is arranged on the disengaging mechanism and connected with the synchronizer.

The invention further provides a drive release mechanism for a pure electric four-wheel drive vehicle, comprising: a motor is disengaged, a torque demand signal is acquired from the vehicle control unit, and a disengagement torque is output; the speed reducing mechanism comprises a multi-stage speed reducer, the input end of the multi-stage speed reducer is connected with the disconnecting motor, and the output end of the multi-stage speed reducer is connected with the disconnecting component; and the input end of the disengaging component is connected with the speed reducing mechanism, the output end of the disengaging component is connected with the synchronizer assembly, and the synchronizer assembly outputs or cuts off power according to the torque requirement.

Further, the multistage speed reducer comprises a first-stage speed reducer and a second-stage speed reducer which are connected in series, and the input end of the first-stage speed reducer is connected with the disconnecting motor; the multistage speed reducer reduces the rotating speed output by the disengaging motor, amplifies the torque output by the disengaging motor and then transmits the amplified torque to the disengaging assembly.

Furthermore, the disengaging assembly comprises a gear shifting drum and a shifting fork, the shifting drum is pushed to move when rotating, then a synchronizing ring on the synchronizer assembly is driven to move left and right, and an intermediate shaft separated from the synchronizer assembly is combined or separated.

Furthermore, a position sensor is arranged on the shifting fork, and the position sensor monitors the left and right movement of the shifting fork through a permanent magnet.

The present invention also provides a decoupling method of driving a decoupling mechanism, comprising: the controller calculates the working condition according to the current running state of the vehicle and the information of the vehicle sensor actuator, and calculates the target position of the current disconnecting component; the controller judges the actual position of the disengaging assembly; when the actual position of the disengagement assembly is consistent with the target position, the current state of the disengagement assembly is kept, otherwise, the disengagement motor is controlled to operate; and after the rotating speed output by the disconnecting motor is reduced and the output torque is amplified, starting the disconnecting component.

Further, the controller judges the actual position of the disengaging assembly according to the position sensor signal and the disengaging motor corner information acquired in real time.

The invention finally provides a motor vehicle having any of the drive release mechanisms described above.

The invention can realize the conversion of four-wheel drive and two-wheel drive states of the vehicle in different driving modes, different working conditions and different environments, thereby realizing the dynamic property of the four-wheel drive and the real-time economical property of the four-wheel drive.

Drawings

Fig. 1 is a flowchart of a drive disengagement method of a first embodiment of the present invention.

Fig. 2 is a partial flow chart of a drive disengagement method of the first embodiment of the present invention.

Fig. 3 is a simple block schematic diagram of a drive release mechanism of a second embodiment of the present invention.

Fig. 4 is a detailed block schematic diagram of a drive release mechanism of a second embodiment of the present invention.

Fig. 5 is a detailed structural view of a drive release mechanism of a second embodiment of the present invention.

Fig. 6 is a flowchart of a drive disengagement method of a third embodiment of the present invention.

Fig. 7 is a detailed flowchart of the drive release method of the third embodiment of the present invention.

Detailed Description

The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

The terms "mounted," "connected," "fixed" and the like in the description and claims of the present invention are to be construed broadly and may, for example, be fixedly connected or detachably connected or integrated; may be mechanically, electrically or otherwise in communication with each other; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood according to specific situations by those of ordinary skill in the art.

First embodiment

Referring to fig. 1, a first embodiment of the present invention provides a drive disengaging method for a pure electric four-wheel drive vehicle, including:

step S2, acquiring a torque demand;

the invention notices that for pure electric four-wheel drive vehicles, under some working conditions, such as sliding, speed reduction, low load, urban congestion road conditions and the like, the vehicles can meet the driving requirements of customers when working in a two-wheel drive mode, and the two-wheel drive mode is generally a rear drive mode. Under some working conditions, such as cross country, climbing a large slope, accelerating a large accelerator, driving on ice and snow roads and the like, a four-wheel drive mode is required. When the vehicle runs in the two-drive mode, the rotor of the front drive motor is reversely dragged by the front wheel and works in the zero-torque mode, so that the non-economical performance of reverse dragging friction energy consumption and zero-torque control power consumption energy consumption exists, counter electromotive force can be generated during zero-torque work to damage the controller, and the drivability problem can be caused by zero-torque work;

the vehicle torque demand can be obtained through vehicle running state information, such as vehicle position information, vehicle speed, engine running state, running state information of each component of the vehicle, and the like, and can also be ADAS state data information, and the like, so that the torque demand can be obtained in time through comprehensive judgment on the vehicle information;

step S4, determining a target position of the disconnect mechanism based on the torque demand;

when the information of the vehicle sensor actuator is used for working condition calculation, factors such as driving performance, dynamic performance, safety and the like of the vehicle can be considered; the working condition is four-wheel drive or two-wheel drive, or whether some wheels are used as driving wheels; calculating and acquiring a disengagement or engagement demand through a working condition, and acquiring a target position of a disengagement mechanism;

step S6, acquiring the position of a synchronizer connected with the intermediate shaft, wherein the synchronizer is connected with a driving motor and a release mechanism;

the middle shaft is connected with a driving motor and is used for transmitting or cutting off power transmitted to the driving motor through the separation and combination of the left section and the right section;

step S8, obtaining the current rotation angle of the disengaging motor which provides power for the disengaging mechanism;

the disengaging motor can control whether to output power through left rotation and right rotation;

step S10, determining the current position of the disengaging mechanism based on the synchronizer position and the current rotation angle of the disengaging motor;

a step S12 of rotating the disengagement motor based on the current position and the target position of the disengagement mechanism;

the current position is, for example, the release mechanism bringing the vehicle into a four-wheel drive state; or the disengaging mechanism enables the vehicle to be in a two-drive state; the target state is, for example, a two-drive state or a four-drive state of the vehicle;

step S14, adjusting the rotating speed and the torque output by the disengaging motor from the current position to the target position;

see in particular fig. 2. The step of adjusting the release mechanism from the current position to the target position by causing the release motor to output the rotation speed and the torque, i.e., step S14, may include:

step S142, reducing the rotation speed output by the disengaging motor in multiple stages and amplifying the output torque in multiple stages;

and step S144, adjusting the disengaging mechanism from the current position to the target position by using the multi-stage reduced rotating speed and the multi-stage amplified torque.

Before the step of determining the current position of the disengagement mechanism based on the synchronizer position and the current rotation angle of the disengagement motor, i.e., before step S10, the method further comprises the steps of:

in step S9, a synchronizer position is acquired based on a position sensor provided in the release mechanism and connected to the synchronizer.

Second embodiment

See fig. 3. The second preferred embodiment of the present invention provides a drive disengaging mechanism of pure electric four-wheel drive vehicle type, which comprises a disengaging motor 20, a speed reducing mechanism 40 and a disengaging assembly 60. The disengagement motor 20 receives a torque demand signal from the controller 10 and outputs a disengagement torque. The controller 10 may be a vehicle control unit. The reduction mechanism 40 comprises a multi-stage reduction gear having an input connected to the decoupling motor 20 and an output connected to the decoupling assembly 60. The input end of the disengaging component 60 is connected with the speed reducing mechanism 40, the output end is connected with the synchronizer assembly 50, and the synchronizer assembly 50 outputs or cuts off power according to the torque requirement.

See fig. 4. In the present embodiment, the multistage speed reducer includes a first stage speed reducer 42 and a second stage speed reducer 44 connected in series, and the input end of the first stage speed reducer 42 is connected to the run-off motor 20. The speed reducer is arranged into two stages, each stage can be made to be smaller, so that the occupied space is smaller, and the space in the vehicle can be better utilized.

The decoupling motor 20 is preferably a BLDC (Brushless Direct Current) motor. The disengagement assembly 60 may include a shift drum 62 and a shift fork 64, and the shift drum 62 rotates to push the shift fork 64 to move through a groove on the shift drum 62, so as to drive the synchronizing ring 52 on the synchronizer assembly 50 to move left and right, to engage or disengage the separated intermediate shaft 72 of the synchronizer assembly 50, to disengage and engage the synchronizer assembly 50, to cut off power transmitted to the wheel 74, or to transmit power to the wheel 74. The disengagement assembly 60 can also be implemented in other ways: such as a hydraulic clutch, an ECVT, and other gear box designs, which are not described herein.

The shift fork 64 is provided with a position sensor 66, and the position sensor 66 monitors the left and right movement of the shift fork 64 by a permanent magnet, and feeds back the position information of the trip unit 60 to the controller 10. Similarly, the trip motor 20 may not only serve as an actuator for the trip mechanism, but may also be used to calculate trip mechanism status information by feeding back the angle of rotation to the controller 10 via its internal hall sensor. The controller 10 may verify the information from the position sensor 66 and the trip motor 20 against each other to confirm accurate position information for the trip mechanism. When the position sensor 66 and the disengagement mechanism position information reflected by the disengagement motor 20 are the same, the position information is determined as the current position information of the disengagement mechanism. The current position is, for example, a set angle of a right turn of a disconnecting motor, a shifting fork enables two ends of an intermediate shaft to be connected through a synchronizer, and a vehicle is in a four-wheel drive state; or the motor is separated from the left to rotate by a set angle, the two ends of the intermediate shaft are separated by the shifting fork through the synchronizer, and the vehicle is in a two-drive state.

The multistage decelerator transmits the BLDC power to reduce the rotation speed of the output of the decoupling motor 20, and amplifies the torque of the output of the decoupling motor 20 to transmit to the decoupling assembly 60. After the speed is reduced, the BLDC rotating speed with high rotating speed control precision is reduced in proportion by the disconnecting motor 20, and the rotating speed control precision is further improved. Meanwhile, the torque is amplified, and small-torque control can be adopted, so that the cost of the BLDC is reduced.

Referring to fig. 5, in a specific embodiment, the technical scheme can disconnect the front drive in a pure electric four-wheel drive vehicle, so that the front drive motor is not dragged reversely, and the rear drive is driven independently, thereby avoiding the economic and driveability problems caused by reverse dragging of the rotor of the front drive motor and zero torque control. The trip motor 20 is a BLDC small motor, the multi-stage reduction gear includes a first stage reduction gear 42 and a second stage reduction gear 44, the power output from the BLDC small motor is transmitted to the shift drum 62, and the shift fork 64 is provided with a permanent magnet bar of a position sensor 66. Fork 64 is also coupled to synchronizer assembly 50. The drive motor 30 is a front drive motor and the wheels are front drive wheels, and the drive motor 30 transfers power to the front drive wheels 74 through the synchronizer assembly 50 and the intermediate shaft 72.

Referring to fig. 5 again, when the disengaging mechanism is in the disengaged state, if the engagement requirement is met, the BLDC small motor is controlled to rotate forward, and the BLDC small motor drives the shift drum to rotate forward by disengaging the first-stage speed reducer and the second-stage speed reducer. The shifting fork is pushed to move rightwards by the rotation of the shifting drum, so that a synchronizing ring on the synchronizer assembly is driven to move rightwards, the left end and the right end of a middle shaft separated from the synchronizer assembly are combined, and the power of an input shaft of a front driving motor can be transmitted, namely the combination of a release mechanism.

Third embodiment

Referring to fig. 6 and 7, the present embodiment provides a control method or a disengagement method of a drive disengagement mechanism of a pure electric four-wheel drive vehicle type, including:

step Sb, the controller calculates the working condition according to the current running state of the vehicle and the information of the vehicle sensor actuator, and calculates the target position or the target state of the current disconnecting component;

when the vehicle runs, the current running state of the vehicle is, for example, vehicle position information, vehicle speed, engine running state, running state information of each component of the vehicle, and the like, and can also be ADAS state data information and the like, so that the vehicle information can be comprehensively judged and prompted in time;

when the information of the vehicle sensor actuator is used for working condition calculation, factors such as driving performance, dynamic performance, safety and the like of the vehicle can be considered; the working condition is four-wheel drive or two-wheel drive, or whether some wheels are used as driving wheels; calculating and acquiring a disengagement or engagement demand through a working condition;

step Sd, the controller judges the actual position of the disengaging assembly;

the controller 10 judges the actual position of the disengaging assembly 60 according to the position sensor signal and the disengaging motor corner information acquired in real time; the disengaging assembly 60 comprises a gear shifting drum 62 and a shifting fork 64, when the disengaging motor 20 starts the disengaging assembly 60, the gear shifting drum 62 rotates to push the shifting fork 64 to move, so that a synchronizing ring 52 on the synchronizer assembly 50 is driven to move left and right, and the left end and the right end of an intermediate shaft 72 connected with the synchronizer assembly 50 are combined or separated;

step Sf, when the actual position of the disconnecting component is consistent with the target position, the current state of the disconnecting component is kept, otherwise, the disconnecting motor is controlled to operate;

before the controller is disengaged from the motor to act, the rotating speed and the torque difference of two end shafts of the synchronizer are required to be ensured to be within a certain range;

sh, after the rotating speed output by the disconnecting motor is reduced and the output torque is amplified, the disconnecting assembly is started;

the disengaging motor drives the gear shifting drum to operate through a secondary speed reducer, so that the shifting fork is driven to move;

when the shifting fork 64 moves, the position sensor 66 can monitor the position of the synchronizer by monitoring the permanent magnet strip 662 running synchronously with the shifting fork 64, so as to monitor the position information of the release mechanism and feed the information back to the controller 10 in real time. The BLDC rotation angle information is fed back in real time during the operation of the BLDC to determine the position of the release mechanism, and the information is fed back in real time.

In summary, the invention has been designed to provide a motor disengageable method and mechanism for disengaging a driving motor, such as a front driving motor or a rear driving motor, in order to take note of some working conditions, such as coasting deceleration, the possibility that a front driving motor is dragged backwards, the possibility that energy consumption, zero-torque control, drivability and the like exist in a four-wheel drive vehicle. The structure is combined with a logic control method, the BLDC small motor is controlled to rotate to drive the gear shifting drum to act, and then the synchronizer is separated and combined, so that the separation and combination of the motor and the half shaft are realized. According to the technical scheme, after the first-stage reduction gear and the second-stage reduction gear are adopted for reducing, the BLDC rotating speed with high rotating speed control precision per se is reduced in proportion, and the rotating speed control precision is further improved. Meanwhile, the torque is amplified, and small-torque control can be adopted, so that the cost of the BLDC is reduced. According to the technical scheme, the vehicle can realize four-wheel drive and two-wheel drive state conversion in different driving modes, different working conditions and different environments through a set of complete disengagement method and/or control method, so that the four-wheel drive power performance can be realized, and the real-time four-wheel drive economy can also be realized.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.

Claims

1. A drive disengagement method for a pure electric four-wheel drive vehicle is characterized by comprising the following steps:

acquiring a torque demand;

determining a target position of the disconnect mechanism based on the torque demand;

acquiring the position of a synchronizer connected with an intermediate shaft, wherein the synchronizer is connected with a driving motor and the release mechanism;

obtaining a current rotation angle of a release motor for supplying power to the release mechanism;

determining a current position of the disconnect mechanism based on a synchronizer position and a current rotational angle of a disconnect motor;

rotating the trip motor based on a current position and a target position of the trip mechanism; and

and adjusting the release mechanism from the current position to the target position by using the rotating speed and the torque output by the release motor.

2. The drive disengagement method according to claim 1, wherein: the step of adjusting the release mechanism from the current position to the target position by the rotating speed and the torque output by the release motor comprises the following steps:

the rotating speed output by the disengaging motor is reduced in a multi-stage mode, and the output torque is amplified in a multi-stage mode;

the multi-stage reduced rotation speed and the multi-stage amplified torque are used for adjusting the release mechanism from the current position to the target position.

3. The drive release method according to claim 1, characterized in that: the step of determining the current position of the disengagement mechanism based on the synchronizer position and the current rotational angle of the disengagement motor is preceded by the step of:

and acquiring the position of the synchronizer based on a position sensor which is arranged on the disengaging mechanism and connected with the synchronizer.

4. A drive release mechanism for pure electric four-wheel drive vehicle type, comprising:

a disengagement motor (20) for acquiring a torque demand signal from the vehicle control unit and outputting a disengagement torque;

the speed reducing mechanism (40) comprises a multi-stage speed reducer, the input end of the multi-stage speed reducer is connected with the disconnecting motor (20), and the output end of the multi-stage speed reducer is connected with a disconnecting component (60); and

and the input end of the disengaging component (60) is connected with the speed reducing mechanism (40), the output end of the disengaging component is connected with the synchronizer assembly (50), and the synchronizer assembly (50) outputs or cuts off power according to the torque requirement.

5. The drive disconnect mechanism of claim 4, wherein:

the multi-stage speed reducer comprises a first-stage speed reducer (42) and a second-stage speed reducer (44) which are connected in series, and the input end of the first-stage speed reducer (42) is connected with the disconnecting motor (20);

the multi-stage speed reducer reduces the rotating speed output by the disengaging motor (20), amplifies the torque output by the disengaging motor (20), and transmits the amplified torque to the disengaging assembly (60).

6. The drive disconnect mechanism of claim 4, wherein: the disengaging assembly (60) comprises a gear shifting drum (62) and a shifting fork (64), and the shifting drum (62) pushes the shifting fork (64) to move when rotating, so that a synchronizing ring (50) on the synchronizer assembly (50) is driven to move left and right, and an intermediate shaft (72) separated from the synchronizer assembly (50) is combined or separated.

7. The drive disconnect mechanism of claim 6, wherein: a position sensor (64) is arranged on the shifting fork (64), and the position sensor (64) monitors the left and right movement of the shifting fork (64) through a permanent magnet.

8. A method of disengaging a drive disengaging mechanism according to any of claims 4 to 7, comprising:

the controller calculates the working condition according to the current running state of the vehicle and the information of the vehicle sensor actuator, and calculates the target position of the current disconnecting component;

the controller judges the actual position of the disengaging assembly;

when the actual position of the disengagement assembly is consistent with the target position, the current state of the disengagement assembly is kept, otherwise, the disengagement motor is controlled to operate; and

and after the rotating speed output by the disconnecting motor is reduced and the output torque is amplified, the disconnecting assembly is started.

9. The disengagement method of driving the disengagement mechanism according to claim 8, characterized in that: and the controller judges the actual position of the disengaging assembly according to the position sensor signal and the disengaging motor corner information acquired in real time.

10. A motor vehicle, characterized in that it has a drive release mechanism according to any one of claims 4 to 7.