Control method for a differential lock, differential lock control system and vehicle

Abstract

The present disclosure relates to a control method of a differential lock, the differential lock being arranged between a first drive axle and a second drive axle, the differential lock having a first gear and a second gear, the first gear being engaged with a first drive gear of the first drive axle, the second gear being used to lock or unlock a second drive gear of the second drive axle, the control method comprising: after the differential lock fails to perform a working mode; step S1: controlling the second gear to rotate relatively with the second drive gear, and controlling the differential lock to perform the working mode again; and step S2: when the differential lock fails to perform the working mode and the number of failures is lower than a preset threshold, performing step S1 again. In this way, in a stationary state of the vehicle, the gap between the second gear and the second drive gear is utilized to control the relative rotation therebetween, thereby improving the success rate of the locking mode and the unlocking mode of the differential lock.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the field of vehicle transmission technology, in particular, to a control method of a differential lock, a differential lock control system and a vehicle. BACKGROUND

[0002] The configuration of the differential lock is often used to evaluate the escape performance of an off-road vehicle. The more the differential lock is configured, the stronger the escape ability of the vehicle in extreme situations. The differential lock generally includes a front axle differential lock, a rear axle differential lock and a central differential lock. When the front axle differential lock is locked, the front axle left and right wheel torque transmission is hard connected. When the rear axle differential lock is locked, the rear axle left and right wheel torque transmission is hard connected. When the central differential lock is locked, it is generally used to transmit power from the front axle to the rear axle or transmit power from the rear axle to the front axle.

[0003] When the vehicle is trapped, the user controls the differential lock to realize wheel differential control or same speed control to realize escape. The prerequisite for realizing escape is that the differential lock can be successfully controlled to be unlocked or locked. In actual application scenarios, the differential lock may not be successfully locked or unlocked, which affects the escape of the vehicle. SUMMARY

[0004] The purpose of the present disclosure is to provide a control method of a differential lock, a differential lock control system and a vehicle to at least partially solve the problems in the related art.

[0005] To achieve the above-mentioned purpose, the present disclosure provides a control method of a differential lock, the differential lock being arranged between a first drive axle and a second drive axle, the differential lock having a first gear and a second gear, the first gear being engaged with a first drive gear of the first drive axle, the second gear being used to lock or unlock a second drive gear of the second drive axle, the control method comprising:

[0006] after the differential lock fails to execute a working mode;

[0007] Step S1: controlling the second gear to rotate relative to the second drive gear to control the differential lock to execute the working mode again; and

[0008] Step S2: when the differential lock fails to execute the working mode and the number of failures is less than a preset threshold, executing step S1 again.

[0009] Optionally, the rotation directions of the second gear relative to the second drive gear in adjacent two times of controlling the second gear to rotate relative to the second drive gear are opposite.

[0010] Optionally, when the number of times that the differential lock fails to execute the working mode is greater than or equal to the preset threshold, the control method further comprises: controlling the differential lock to stop executing the working mode.

[0011] Optionally, the step of controlling the second gear to rotate relative to the second drive gear comprises controlling the second drive gear to rotate, and / or controlling the first drive gear to rotate.

[0012] Optionally, the step of controlling the second gear to rotate relative to the second drive gear comprises:

[0013] determining whether the vehicle is stationary;

[0014] controlling the second gear to rotate relative to the second drive gear when the vehicle is stationary.

[0015] Optionally, the control method further comprises: controlling the second gear to stop rotating relative to the second drive gear when the differential lock successfully executes the working mode.

[0016] Optionally, the step of determining whether the differential lock successfully executes the working mode comprises: obtaining position information of the differential lock and comparing the position information with preset position information.

[0017] Optionally, the working mode comprises a locking mode for engaging the second gear with the second drive gear, and the control method comprises:

[0018] controlling the second gear to move a distance L away from the second drive gear before controlling the second gear to rotate relative to the second drive gear.

[0019] Optionally, the working mode comprises an unlocking mode for disengaging the second gear from the second drive gear, and the control method comprises:

[0020] obtaining a relative position relationship between the second gear and the second drive gear after the differential lock fails to execute the working mode;

[0021] determining a direction of relative rotation between the second gear and the second drive gear according to the obtained relative position relationship.

[0022] According to a second aspect of the present disclosure, a differential lock control system is also provided. The differential lock is arranged between a first drive axle and a second drive axle. The differential lock has a first gear and a second gear. The first gear is engaged with a first drive gear of the first drive axle. The second gear is used to lock or unlock a second drive gear of the second drive axle. The differential lock control system comprises:

[0023] an execution module configured to control the differential lock to execute a working mode;

[0024] a judging module, configured to judge whether the working mode of the differential lock is executed successfully, and to judge whether the vehicle is stationary after the differential lock fails to execute the working mode;

[0025] a receiving module, configured to receive the judging result of the judging module, and

[0026] a control module, configured to control the relative movement between the second gear and the second driving gear according to the information received by the receiving module.

[0027] Optionally, the judging module comprises a position sensor configured to detect the position of the differential lock, and a wheel speed sensor configured to detect the wheel speed.

[0028] Optionally, the control module comprises a control device, a first driving motor configured to drive the first driving gear, a second driving motor configured to drive the second driving gear, and a differential lock motor configured to drive the differential lock to move, and the control device is electrically connected with the first driving motor, the second driving motor, and the differential lock motor respectively.

[0029] According to a third aspect of the present disclosure, there is also provided a vehicle comprising the differential lock control system as described above.

[0030] By means of the above technical solution, relying on the advantages of the four-wheel independent drive architecture, in the stationary state of the vehicle, the gap of the gear teeth of the second gear and the second driving gear in the circumferential direction of the gear is fully utilized to control the relative rotation of the second gear and the second driving gear, so that the locking can be achieved when the second gear and the second driving gear are partially engaged, and the unlocking can be achieved when the second gear and the second driving gear are too tight, thereby improving the success rate of the locking mode and the unlocking mode of the differential lock in the stationary state of the vehicle, reducing the redundant interaction cost, to a certain extent, simplifying the user operation, and improving the user experience.

[0031] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF DRAWINGS

[0032] The accompanying drawings are included to provide a further understanding of the present disclosure and constitute a part of the specification, and are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation on the present disclosure. In the drawings:

[0033] Figure 1 is a flow chart of the control method of the differential lock provided by an exemplary embodiment of the present disclosure;

[0034] Figure 2 is a structural schematic diagram of the differential lock control system provided by an exemplary embodiment of the present disclosure when the differential lock is in the locking position;

[0035] Figure 3 is a schematic diagram of the differential lock control system provided by an example embodiment of the present disclosure when the differential lock is in the unlocked position;

[0036] Figure 4 is a schematic diagram of the connection of the differential and drive axle when the differential lock is in position B in the differential lock control system provided by an example embodiment of the present disclosure;

[0037] Figure 5 is a schematic diagram of the connection of the differential and drive axle when the differential lock is in position D in the differential lock control system provided by an example embodiment of the present disclosure;

[0038] Figure 6 is a schematic diagram of the connection of the differential and drive axle when the differential lock is in position E in the differential lock control system provided by an example embodiment of the present disclosure;

[0039] Figure 7 is an assembly diagram of the gears in the differential lock control system provided by an example embodiment of the present disclosure when the differential lock is in the regular locked position;

[0040] Figure 8 is an assembly diagram of the gears in the differential lock control system provided by an example embodiment of the present disclosure when the differential lock fails to lock and partial tooth engagement occurs;

[0041] Figure 9 is a schematic diagram of the output torque of the second drive motor after the differential lock fails to lock in the differential lock control system provided by an example embodiment of the present disclosure;

[0042] Figure 10 is an assembly diagram of the gears in the differential lock control system provided by an example embodiment of the present disclosure when the differential lock fails to unlock;

[0043] Figure 11 is a schematic diagram of the output torque of the second drive motor after the differential lock fails to unlock in the differential lock control system provided by an example embodiment of the present disclosure;

[0044] Figure 12 is a line graph of the drive motor torque and differential lock position in the unlocked mode in the differential lock control system provided by an example embodiment of the present disclosure.

[0045] BRIEF DESCRIPTION OF THE DRAWINGS

[0046] 11 first drive motor 12 second drive motor

[0047] 21 first drive axle 22 second drive axle

[0048] 3 differential lock 31 first gear

[0049] 32 second gear 41 first drive gear

[0050] 42 second drive gear 51 first transmission gear

[0051] 52 second transmission gear 61 first output gear

[0052] 62 second output gear DETAILED DESCRIPTION

[0053] The specific embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely intended to illustrate and explain the present disclosure, and are not intended to limit the present disclosure.

[0054] In the present disclosure, the terms "first", "second" and the like used in the present disclosure are used to distinguish one element from another element, and do not have sequential and important meanings. In the present disclosure, when the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated.

[0055] Referring to Figure 1 , the present disclosure provides a control method of a differential lock, wherein the differential lock 3 is arranged between a first drive axle 21 and a second drive axle 22, the differential lock 3 has a first gear 31 and a second gear 32, the first gear 31 is engaged with a first drive gear 41 of the first drive axle 21, and the second gear 32 is used to lock or unlock a second drive gear 42 of the second drive axle 22, the control method can include: after the differential lock 3 fails to execute a working mode; step S1: controlling the second gear 32 to rotate relative to the second drive gear 42, and controlling the differential lock 3 to execute the working mode again; and step S2: when the differential lock 3 fails to execute the working mode and the number of failures is less than a preset threshold, executing step S1 again. The above-mentioned preset threshold can be set according to actual needs, and the present disclosure does not limit the comparison. The control method of the present disclosure can be applied to a four-wheel independent drive or two-wheel independent drive vehicle, that is, the driving motors at both ends of the same shaft can be independently controlled.

[0056] Specifically, whether the working mode of the differential lock 3 is executed successfully can be judged according to the position of the first gear 31, and reference is made to Figures 3-5When the right end of the first gear 31 is located at position A, the differential lock 3 is in the locking limit position; when the right end of the first gear 31 is located at position B, the differential lock 3 is in the normal locking position; when the right end of the first gear 31 is located at position C, the differential lock 3 is in the transition position; when the right end of the first gear 31 is located at position D, the differential lock 3 is in the initial unlocking position; when the right end of the first gear 31 is located at position E, the differential lock 3 is in the normal unlocking position; and when the right end of the first gear 31 is located at position F, the differential lock 3 is in the unlocking limit position. When the right end of the first gear 31 is located at position B, it is determined that the differential lock is successfully locked; and when the right end of the first gear 31 is located at position E, it is determined that the differential lock is successfully unlocked. In other embodiments, when the right end of the first gear 31 is located at positions A to E, it can also be determined that the differential lock is successfully locked; and when the right end of the first gear 31 is located at positions D to F, it can also be determined that the differential lock is successfully unlocked. It should be noted that the "right" described above is based on the direction of the drawing, and corresponds to the direction of the vehicle with reference to the direction of the drawing in Figures 3-5 .

[0057] By the above technical solution, relying on the architectural advantages of four-wheel independent drive, in the vehicle stationary state, the gap of the teeth of the second gear and the second drive gear in the gear circumferential direction is fully utilized to control the relative rotation of the second gear and the second drive gear, so that the locking can be achieved when the second gear and the second drive gear are partially toothed, and the unlocking can be achieved when the engagement surface of the second gear and the second drive gear is too tight, thereby improving the success rate of the differential lock locking mode and the unlocking mode in the vehicle stationary state, reducing the redundant interaction cost, to a certain extent, simplifying the user operation and improving the user experience.

[0058] Specifically, in the locking process, there may be a failure, as shown in Figure 7 , the second gear 32 and the second drive gear 42 are partially toothed, with reference to Figure 8 , the second drive gear 42 is controlled to move left, and the gap of the teeth of the second gear 32 and the second drive gear 42 in the gear circumferential direction is utilized to achieve successful locking. In addition, while controlling the second drive gear 42 to move left, the second gear 32 can also be controlled to move right, so as to more quickly make the teeth of the second gear 32 and the tooth grooves of the second drive gear 42 relatively move and then achieve locking; in the unlocking process, as shown in Figure 9 , the engagement surface of the second gear 32 and the second drive gear 42 may be too tight, which causes the unlocking to fail. At this time, with reference to Figure 10, the second driving gear 42 is controlled to move right to relieve the over-tight condition of the meshing surface, so as to improve the unlocking probability. In addition, the second gear 32 can be controlled to move left at the same time when the second driving gear 42 is controlled to move right, so as to relieve the over-tight condition of the meshing surface more quickly and achieve the unlocking. It should be noted that the "left" and "right" above are based on the direction of the drawing, and the specific reference Figures 6-10 is the direction of the drawing.

[0059] Further, the rotation directions of the second gear 32 and the second driving gear 42 controlled to rotate relatively in two adjacent times are opposite. Specifically, after the first relative rotation of the second gear 32 and the second driving gear 42, if the working mode of the differential lock 3 is not successfully executed, it indicates that the position of the partial tooth engagement between the second driving gear 42 and the second gear 32 is on the other side. The second relative rotation in the direction opposite to the first relative rotation is performed to successfully execute the working mode of the differential lock 3.

[0060] Still further, when the number of times that the differential lock 3 fails to execute the working mode is greater than or equal to a preset threshold, the control method can further include: controlling the differential lock 3 to stop executing the working mode, at this time, the relative movement of the second gear 32 and the second driving gear 42 is stopped, waiting to enter the driving state, continuing to execute the working mode, or executing the timeout and outputting the failure to execute the working mode.

[0061] The step of controlling the second gear 32 and the second driving gear 42 to rotate relatively can include: controlling the second driving gear 42 to rotate, or controlling the first driving gear 41 to rotate, or controlling the second driving gear 42 and the second gear 32 to rotate in opposite directions. In the vehicle stationary state, the relative rotation angle of the second driving gear 42 and the second gear 32 can only be controlled within a certain range. Specifically, the limit value of the relative rotation angle of the second driving gear 42 and the second gear 32 is the central angle of the gap between the teeth of the second driving gear 42 and the second gear 32 in the circumferential direction when the two gears are engaged.

[0062] Specifically, the step of controlling the second gear 32 and the second driving gear 42 to rotate relatively includes: judging whether the vehicle is stationary; and controlling the second gear 32 and the second driving gear 42 to rotate relatively when the vehicle is stationary.

[0063] Further, the control method can further include: when the differential lock 3 successfully executes the working mode, controlling the second gear 32 and the second driving gear 42 to stop rotating relatively. Specifically, the reference Figure 12In the unlocking mode of the differential lock 3, the driving motor needs to maintain a large torque to slow down the gear meshing surface, but once the unlocking starts, the position of the lock sleeve changes, and the torque of the driving motor needs to be unloaded before the differential lock 3 reaches position D, to avoid transmission to the wheel end and produce a jolt.

[0064] In some embodiments, the step of judging whether the working mode of the differential lock 3 is successfully executed can include: obtaining the position information of the differential lock 3 and comparing it with the preset position information, and specifically, the position information of the differential lock 3 can be compared with positions A, B, C, D, E, and F in FIG. 1 to judge whether the working mode of the differential lock 3 is successfully executed. Figures 4-6

[0065] As an example embodiment of the present disclosure, the working mode can include a locking mode for engaging the second gear 32 with the second driving gear 42, and the control method can include: moving the second gear 32 away from the second driving gear 42 by a distance L before controlling the relative rotation of the second gear 32 and the second driving gear 42. Here, the relative movement refers to the first relative rotation and the second relative rotation. After the differential lock 3 fails to execute the locking mode, it indicates that there may be partial tooth engagement. In the embodiment of the present disclosure, at this time, the right end of the first gear 31 is located at position D, the second gear 32 is moved away from the second driving gear 42 by a distance L, D+L≤E, and after the second gear 32 and the second driving gear 42 are controlled to rotate relative to each other, the locking mode is executed again, and the differential lock 3 reaches position B, indicating that the locking is successful.

[0066] As another example embodiment of the present disclosure, the working mode can include an unlocking mode for disengaging the second gear 32 from the second driving gear 42, and the control method can include: after the differential lock 3 fails to execute the working mode, obtaining the relative position relationship between the second gear 32 and the second driving gear 42, specifically, the relative position relationship between the two can be obtained through a position sensor; determining the direction of the relative rotation of the second gear 32 and the second driving gear 42 according to the obtained relative position relationship, that is, determining the direction of the relative rotation according to the edge of the second gear 32 and the second driving gear 42 that is in close contact.

[0067] ​According to a second aspect of the present disclosure, a differential lock control system is also provided, the differential lock 3 is arranged between the first drive axle 21 and the second drive axle 22, the differential lock 3 has a first gear 31 and a second gear 32, the first gear 31 is engaged with the first drive gear 41 of the first drive axle 21, the second gear 32 is used to lock or unlock the second drive gear 42 of the second drive axle 22, the differential lock control system can include an execution module, a judgment module, a receiving module and a control module, wherein the execution module is used to control the differential lock 3 to execute the working mode; the judgment module is used to judge whether the working mode of the differential lock 3 is executed successfully; and after the differential lock 3 fails to execute the working mode, it is judged whether the vehicle is stationary; the receiving module is used to receive the judgment result of the judgment module; the control module is used to control the relative motion between the second gear 32 and the second drive gear 42 according to the information received by the receiving module. The differential lock control system has all the beneficial effects of the control method of the differential lock described above, which will not be repeated here.

[0068] Wherein, the judgment module can include a position sensor for detecting the position of the differential lock 3 and a wheel speed sensor for detecting the wheel speed. The position information of the differential lock 3 is obtained by the position sensor and compared with the preset position information; the wheel speed sensor can obtain the information of whether the vehicle is stationary for judgment.

[0069] Further, the control module can include a control device, a first drive motor 11 for driving the first drive gear 41, a second drive motor 12 for driving the second drive gear 42, and a differential lock motor for driving the differential lock 3 to move, and the control device is electrically connected with the first drive motor 11, the second drive motor 12 and the differential lock motor respectively.

[0070] Specifically, reference is made to Figures 7-11The differential lock 3 is used to lock or unlock the power coupling relationship between the first driving motor 11 and the second driving motor 12. The first driving motor 11 can drive the first driving axle 21 to rotate through the first output gear 61. The first driving axle 21 has a first driving gear 41 engaged with the first gear 31 and a first transmission gear 51 engaged with the first output gear 61. Therefore, the first driving motor 11 can directly drive the differential 3 to rotate. The second driving motor 12 can drive the second driving axle 22 to rotate through the second output gear 62. The second driving axle 22 has a second driving gear 42 used to lock or unlock the second gear 32 and a second transmission gear 52 engaged with the second output gear 62. Therefore, the second driving motor 12 drives the second driving axle 22 to rotate through the second driving gear 42. After the differential lock 3 fails to perform the working mode for the first time, the first driving motor 11 outputs a forward torque and / or the second driving motor 12 outputs a reverse torque to control the second gear 32 and the second driving gear 42 to rotate relative to each other for the first time. After the differential lock 3 fails to perform the working mode for the second time, the second driving motor 12 outputs a forward torque and / or the first driving motor 11 outputs a reverse torque to control the second gear 32 and the second driving gear 42 to rotate relative to each other for the second time.

[0071] According to a third aspect of the present disclosure, a vehicle is also provided, which can include the differential lock control system described above. The vehicle has all the beneficial effects of the differential lock control system described above, which will not be repeated here.

[0072] The preferred embodiments of the present disclosure are described in detail above with reference to the accompanying drawings, but the present disclosure is not limited to the specific details in the above-described embodiments. Various simple modifications can be made to the technical solutions of the present disclosure within the technical concept of the present disclosure, and these simple modifications all belong to the protection scope of the present disclosure.

[0073] In addition, it should be noted that each specific technical feature described in the above-described specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, various possible combinations will not be described again in the present disclosure.

[0074] In addition, various different embodiments of the present disclosure can also be combined in any appropriate manner, as long as they do not deviate from the idea of the present disclosure, and they should also be considered as disclosed in the present disclosure.

Claims

1. A control method for a differential lock, characterized in that, The differential lock is disposed between the first drive axle and the second drive axle. The differential lock has a first gear and a second gear. The first gear meshes with a first drive gear of the first drive axle, and the second gear is used to lock or unlock the second drive gear of the second drive axle. The control method includes: After the differential lock fails to execute the operating mode; Step S1: Determine if the vehicle is stationary. When the vehicle is stationary, control the second gear and the second drive gear to rotate relative to each other, and control the differential lock to execute the operating mode again; and Step S2: When the differential lock fails to execute the working mode and the number of failures is less than a preset threshold, step S1 is executed again.

2. The control method according to claim 1, characterized in that, In two consecutive control operations, the second gear and the second drive gear rotate in opposite directions relative to each other.

3. The control method according to claim 1, characterized in that, When the number of times the differential lock fails to execute the working mode is greater than or equal to a preset threshold, the control method further includes: controlling the differential lock to stop executing the working mode.

4. The control method according to claim 1, characterized in that, The step of controlling the relative rotation of the second gear and the second drive gear includes: controlling the rotation of the second drive gear, and / or controlling the rotation of the first drive gear.

5. The control method according to claim 1, characterized in that, The control method further includes: when the differential lock successfully executes the working mode, controlling the second gear and the second drive gear to stop rotating relative to each other.

6. The control method according to claim 1, characterized in that, The steps for determining whether the differential lock's operating mode has been successfully executed include: obtaining the differential lock's position information and comparing it with preset position information.

7. The control method according to any one of claims 1-6, characterized in that, The operating mode includes a locking mode for engaging the second gear with the second drive gear, and the control method includes: Before controlling the second gear to rotate relative to the second drive gear, control the second gear to move a distance L away from the second drive gear.

8. The control method according to any one of claims 1-6, characterized in that, The operating mode includes an unlocking mode for disengaging the second gear from the second drive gear, and the control method includes: After the differential lock fails to execute the working mode, the relative positional relationship between the second gear and the second drive gear is obtained; The direction of relative rotation between the second gear and the second drive gear is determined based on the obtained relative positional relationship.

9. A differential lock control system, characterized in that, The differential lock is disposed between the first drive axle and the second drive axle. The differential lock has a first gear and a second gear. The first gear meshes with a first drive gear of the first drive axle, and the second gear is used to lock or unlock the second drive gear of the second drive axle. The differential lock control system includes: The execution module is used to control the operating mode of the differential lock; The judgment module is used to determine whether the differential lock's working mode has been successfully executed; and after the differential lock fails to execute the working mode, to determine whether the vehicle is stationary. A receiving module, configured to receive the judgment result from the judgment module; and The control module is used to control the relative movement between the second gear and the second drive gear according to the information received by the receiving module.

10. The differential lock control system according to claim 9, characterized in that, The judgment module includes a position sensor for detecting the position of the differential lock and a wheel speed sensor for detecting the wheel rotation speed.

11. The differential lock control system according to claim 9, characterized in that, The control module includes a control device, a first drive motor for driving the first drive gear, a second drive motor for driving the second drive gear, and a differential lock motor for driving the differential lock to move. The control device is electrically connected to the first drive motor, the second drive motor, and the differential lock motor, respectively.

12. A vehicle, characterized in that, The differential lock control system includes any one of claims 9-11.

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