Electric vehicle drivetrain disconnection mechanism and control method, vehicle

Abstract

This invention provides a powertrain disconnection mechanism and control method for electric vehicles, as well as a vehicle. The powertrain disconnection mechanism includes: a passive engagement mechanism fixedly connected to the connecting shaft of a drive motor; an active engagement mechanism connected to the vehicle's drive shaft, slidably disposed along the axial direction of the drive shaft; a first buffer member fixedly connected to either the active or passive engagement mechanism; and a second buffer member elastically connected to the other of the active or passive engagement mechanisms. The active engagement mechanism has an initial position away from the passive engagement mechanism and an engagement position with the passive engagement mechanism. During the process of the active engagement mechanism moving axially to the engagement position, the contact between the first and second buffer members precedes the contact between the active and passive engagement mechanisms. This solution addresses the problem of poor engagement smoothness in existing electric vehicle powertrains by adding a first and a second buffer member.

Description

Technical Field

[0001] This invention relates to the field of vehicle design technology, and more specifically, to an electric vehicle drivetrain disconnection mechanism and control method, and a vehicle. Background Technology

[0002] With the widespread adoption of electric vehicles, the market supply of high-performance four-wheel-drive electric vehicles is increasing, providing users with a better driving experience. However, while improving power, the energy consumption per unit mile of four-wheel-drive electric vehicles also increases. Both national and individual levels have higher requirements for the energy efficiency of electric vehicles, aiming to save energy and alleviate range anxiety. Therefore, numerous studies are attempting to improve the energy efficiency of electric vehicles, including optimizing the performance of drive motors and motor inverters. For four-wheel-drive electric vehicles, in most user scenarios, a single drive motor is sufficient for daily acceleration, causing the other drive motor to operate in a constant follow-up mode. Even without outputting torque, the follow-up motor continuously consumes energy. Therefore, some research has explored a disconnection device. When the vehicle's driving force requirements are low, one drive motor is disconnected from the transmission system. This motor is stationary, significantly reducing energy consumption. Studies have shown that under WLTC standard cycle conditions, using this disconnection device can reduce overall vehicle energy consumption by approximately 3%, indirectly increasing the vehicle's driving range.

[0003] Because electric vehicles transmit large torques, multi-plate clutches are generally not used for power transmission; currently, electric vehicle drivetrains typically use jaw clutches. The common control method is that when the disengagement device needs to be engaged, the drive motor's speed is increased, and the jaw clutch closes quickly. Once the jaw clutch is engaged, the drive motor operates in torque mode to respond to the vehicle's drive torque. Since the disengagement device engages when the vehicle has an urgent power demand, to minimize the engagement time, the jaw clutch is engaged when the speed difference between its two ends is large, inevitably leading to engagement shock. Furthermore, due to the characteristics of jaw clutches, when the speed difference between the two ends of the clutch is large during engagement, tooth knocking occurs, further prolonging the engagement time and resulting in an uneven power response. To achieve smooth engagement, the speed difference between the two ends of the clutch before engagement needs to be reduced through control strategies. This requires precise control of the motor speed. Given the variable operating conditions of the vehicle, precise motor speed control is difficult, leading to frequent uneven clutch engagement during actual vehicle operation and reducing vehicle quality.

[0004] There is currently no effective solution to the technical problem of poor smoothness in the drivetrain engagement of electric vehicles. Summary of the Invention

[0005] The main objective of this invention is to provide an electric vehicle drivetrain disconnection mechanism and control method, as well as a vehicle, to solve the problem of poor smoothness of drivetrain engagement in existing electric vehicles.

[0006] To achieve the above objectives, according to one aspect of the present invention, an electric vehicle drivetrain disconnection mechanism is provided, comprising: a passive engagement mechanism, which is fixedly connected to a connecting shaft of a drive motor and rotates synchronously with the connecting shaft; an active engagement mechanism, which is connected to a vehicle drive shaft, which is connected to the input shaft of the vehicle's main reducer and rotates synchronously with the vehicle drive shaft, and is slidably disposed along the axial direction of the vehicle drive shaft; a first buffer member, which is fixedly connected to either the active engagement mechanism or the passive engagement mechanism; and a second buffer member, which is elastically connected to the other of the active engagement mechanism or the passive engagement mechanism; the active engagement mechanism has an initial position away from the passive engagement mechanism and an engagement position with the passive engagement mechanism, wherein during the process of the active engagement mechanism moving along the axial direction to the engagement position, the contact between the first buffer member and the second buffer member precedes the contact between the active engagement mechanism and the passive engagement mechanism.

[0007] Furthermore, the active engagement mechanism includes: a first sliding sleeve, which is sleeved on the vehicle drive shaft and slidably disposed along the axial direction of the vehicle drive shaft, and rotates synchronously with the vehicle drive shaft; an active side gear, which is fixedly connected to the first sliding sleeve, and has an active meshing part on the end face of the active side gear facing the passive engagement mechanism, through which the active engagement mechanism engages with the passive engagement mechanism; and the active side gear is connected to either the first buffer or the second buffer.

[0008] Furthermore, the passive engagement mechanism includes: a passive side gear, which is fixedly connected to the connecting shaft. A passive engagement portion is provided on the end face of the passive side gear facing the active engagement mechanism. The passive engagement mechanism engages with the active engagement mechanism through the passive engagement portion. The passive side gear is connected to another of the first buffer and the second buffer.

[0009] Furthermore, the active side gear is connected to the first buffer member, and the passive side gear is connected to the second buffer member. The first buffer member is a first friction disc, and the second buffer member includes: an elastic member, the first end of which is connected to the passive side gear, and the elastic member extends along the axial direction of the passive side gear; and a second friction disc, which is disposed opposite to the first friction disc and is connected to the second end of the elastic member. During the process of the active engagement mechanism moving to the engagement position along the axial direction, the contact between the first friction disc and the second friction disc precedes the engagement between the passive meshing part and the active meshing part.

[0010] Furthermore, the passive side gear has a passive side central shaft extending toward the side where the active engagement mechanism is located, and the second buffer also includes: a second sliding sleeve connected to the second friction disc, at least a portion of the second sliding sleeve being sleeved on the passive side central shaft, and an elastic element being sleeved on the second sliding sleeve and the passive side central shaft.

[0011] Furthermore, the electric vehicle drivetrain disconnection mechanism also includes a drive mechanism, which is used to drive the active engagement mechanism to slide along the axial direction of the vehicle drive shaft. The drive mechanism includes: an engagement motor; and an engagement transmission component. The input end of the engagement transmission component is connected to the engagement motor, and the output end of the engagement transmission component is connected to the active engagement mechanism. The engagement motor drives the active engagement mechanism to move along the axial direction of the vehicle drive shaft by controlling the engagement transmission component.

[0012] Furthermore, the transmission components include: a drive worm gear, which is rigidly connected to the engagement motor; a drive turbine, which is configured to cooperate with the drive worm gear, and the drive worm gear is rigidly connected to the active engagement mechanism; the rotation of the engagement motor drives the drive worm gear to rotate, the drive worm gear drives the drive turbine gear to move, and in turn drives the active engagement mechanism to move along the axial direction of the vehicle drive shaft.

[0013] Furthermore, the central axis of the connecting shaft is on the same straight line as the central axis of the vehicle drive shaft.

[0014] According to another aspect of the present invention, a control method for a drivetrain disconnection mechanism of an electric vehicle is provided. The control method is used to control the aforementioned drivetrain disconnection mechanism of the electric vehicle. The electric vehicle includes a main drive motor and a secondary drive motor, wherein the secondary drive motor is the aforementioned drive motor. The control method includes the following steps: obtaining the maximum torque of the main drive motor, the current vehicle speed, the current throttle opening, and the engagement time t; obtaining the required drive torque T1 and the torque change rate R1 of the required drive torque based on the current vehicle speed and the current throttle opening; calculating the required torque T2 after the engagement time t based on the required drive torque T1 and the torque change rate R1; determining whether to control the secondary drive motor to participate in driving based on the required torque T2 and the maximum torque of the main drive motor; and generating a control instruction set when it is determined that the secondary drive motor participates in driving, wherein the control instruction set is used to control the active side gear to move to the engagement position with the passive side gear.

[0015] Furthermore, when it is determined that the auxiliary drive motor participates in the drive, a control instruction set is generated, including: obtaining the rotational speed V1 of the vehicle drive shaft and the actual rotational speed V2 of the auxiliary drive motor; when it is determined that the actual rotational speed V2 and the rotational speed V1 meet the first preset condition, a first control instruction is generated in the control instruction set. The first control instruction is used to control the coupled motor to output the first coupled torque T3, so as to drive the active side gear to move toward the side where the passive side gear is located.

[0016] Furthermore, after the motor outputs the first engagement torque T3, the method also includes: obtaining the rotational speed V3 of the second friction disc; calculating the rate of change of rotational speed V3 based on the rotational speed V3; determining that the second friction disc and the first friction disc have completed engagement when the rate of change of rotational speed meets the second preset condition; obtaining the current first engagement torque T3 as the second engagement torque T4; generating a second control instruction in the control instruction set; the second control instruction is used to control the engagement motor to output the second engagement torque T4, so as to continue to drive the active side gear to move toward the side where the passive side gear is located.

[0017] Furthermore, after the motor outputs the second engagement torque T4, the method further includes: obtaining the speed difference between the driven side gear and the driving side gear; when the speed difference meets the third preset condition, generating a third control command in the control command set, the third control command being used to control the engaging motor to output the third engagement torque T5, so as to continue to drive the driving side gear to move towards the side where the driven side gear is located; when the speed difference meets the fourth preset condition and continues for a preset duration, determining that the engaging mechanism and the driven engagement mechanism have completed engagement, generating a fourth control command in the control command set, the fourth control command being used to control the engaging motor to stop outputting torque.

[0018] Furthermore, based on the required torque T2 and the maximum torque of the main drive motor, determining whether to control the auxiliary drive motor to participate in the drive also includes the following steps: if it is determined that the auxiliary drive motor does not participate in the drive, a fifth control command is generated. The fifth control command is used to control the engagement motor to output the separation torque T6, so that the engagement motor rotates in the opposite direction and drives the active engagement mechanism to move from the engagement position to the initial position; the rotational speed of the passive side gear is obtained; if the rotational speed of the passive side gear meets the fifth preset condition, a sixth control command is generated. The sixth control command is used to control the engagement motor to stop outputting torque.

[0019] According to another aspect of the present invention, a vehicle is provided having an electric vehicle drivetrain disconnection mechanism, wherein the electric vehicle drivetrain disconnection mechanism is the electric vehicle drivetrain disconnection mechanism described above.

[0020] By applying the technical solution of this invention, the engagement device of the electric vehicle transmission system is improved. A first buffer and a second buffer are added inside the passive engagement mechanism and the active engagement mechanism. During the engagement process, the first buffer and the second buffer can reduce the speed difference between the passive engagement mechanism and the active engagement mechanism before engagement, thereby reducing the occurrence of tooth tipping phenomenon, improving the smoothness of engagement and engagement speed, and reducing the difficulty of the control algorithm, thus solving the problem of poor engagement smoothness of the electric vehicle transmission system in the prior art. Attached Figure Description

[0021] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0022] Figure 1 A schematic diagram of an embodiment of the electric vehicle drivetrain disconnection mechanism according to the present invention is shown;

[0023] Figure 2 A flowchart illustrating an embodiment of the control method for the electric vehicle drivetrain disconnection mechanism according to the present invention is shown;

[0024] Figure 3 A schematic diagram of the speed ramp-up stage of the electric vehicle drivetrain disconnection mechanism according to the present invention is shown;

[0025] Figure 4 A schematic diagram of the synchronization stage of the electric vehicle drivetrain disconnection mechanism according to the present invention is shown;

[0026] Figure 5 A schematic diagram of the engagement stage of the electric vehicle drivetrain disconnection mechanism according to the present invention is shown;

[0027] Figure 6 A schematic diagram of the structure after the electric vehicle drivetrain disconnection mechanism according to the present invention has been engaged is shown.

[0028] The above figures include the following reference numerals:

[0029] 1. Drive motor; 2. Connecting shaft;

[0030] 3. Passive side gear; 4. Passive side central shaft; 5. Elastic element; 6. Second friction disc; 7. First friction disc; 8. Driving side gear;

[0031] 9. Drives the turbine; 10. Drives the worm gear;

[0032] 11. Combined motor; 12. First sliding sleeve; 13. Vehicle drive shaft. Detailed Implementation

[0033] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0034] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0035] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0036] Exemplary embodiments according to this application will now be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. It should be understood that these embodiments are provided so that the disclosure of this application is thorough and complete, and that the concept of these exemplary embodiments is fully conveyed to those skilled in the art. In the drawings, for clarity, the thickness of layers and regions may be exaggerated, and the same reference numerals are used to denote the same devices, and therefore their description will be omitted.

[0037] like Figure 1 As shown, according to a specific embodiment of this application, an electric vehicle drivetrain disconnection mechanism is provided.

[0038] The electric vehicle drivetrain disconnection mechanism includes a passive engagement mechanism, an active engagement mechanism, a first buffer, and a second buffer. The passive engagement mechanism is fixedly connected to the connecting shaft 2 of the drive motor 1 and rotates synchronously with the connecting shaft 2. The active engagement mechanism is connected to the vehicle drive shaft 13, which is connected to the input shaft of the vehicle's main reducer. The active engagement mechanism rotates synchronously with the vehicle drive shaft 13 and is slidably arranged along the axial direction of the vehicle drive shaft 13. The first buffer is fixedly connected to either the active or passive engagement mechanism. The second buffer is elastically connected to the other of the active or passive engagement mechanism. The active engagement mechanism has an initial position away from the passive engagement mechanism and an engagement position with the passive engagement mechanism. During the process of the active engagement mechanism moving along the axial direction to the engagement position, the contact between the first and second buffers precedes the contact between the active and passive engagement mechanisms.

[0039] By applying the technical solution of this embodiment, the engagement device of the electric vehicle transmission system is improved. A first buffer and a second buffer are added inside the passive engagement mechanism and the active engagement mechanism. During the engagement process, the first buffer and the second buffer can reduce the speed difference between the passive engagement mechanism and the active engagement mechanism before engagement, thereby reducing the occurrence of tooth tipping phenomenon, improving the smoothness of engagement and engagement speed, and reducing the difficulty of the control algorithm, thus solving the problem of poor engagement smoothness of the electric vehicle transmission system in the prior art.

[0040] In this embodiment, the passive engagement mechanism and the active engagement mechanism are dog clutches. The structural principle of this embodiment can also be applied to other types of electric vehicle transmission systems to buffer the engagement of the two transmission mechanisms before engagement, thereby avoiding the problems of large impact caused by rapid engagement and poor smoothness caused by large speed difference.

[0041] The active engagement mechanism includes a first sliding sleeve 12 and an active side gear 8. The first sliding sleeve 12 is sleeved on the vehicle drive shaft 13 and is slidably arranged along the axial direction of the vehicle drive shaft 13. The first sliding sleeve 12 rotates synchronously with the vehicle drive shaft 13. The active side gear 8 is fixedly connected to the first sliding sleeve 12. An active meshing part is provided on the end face of the active side gear 8 facing the passive engagement mechanism. The active engagement mechanism engages with the passive engagement mechanism through the active meshing part. The active side gear 8 is connected to either the first buffer or the second buffer.

[0042] In this embodiment, the active side gear 8 is fixedly connected to the first sliding sleeve 12. The first sliding sleeve 12 rotates synchronously with the vehicle drive shaft 13. The active side gear 8 can slide axially relative to the vehicle drive shaft 13 through the first sliding sleeve 12. The active side gear 8, the first sliding sleeve 12, and the vehicle drive shaft 13 rotate synchronously. The active meshing part is the end face tooth provided on the end face of the active side gear 8 facing the passive engagement mechanism. By controlling the sliding of the active side gear 8, engagement and disengagement with the passive engagement mechanism can be achieved.

[0043] The passive engagement mechanism includes a passive side gear 3, which is fixedly connected to the connecting shaft 2. A passive meshing part is provided on the end face of the passive side gear 3 facing the active engagement mechanism. The passive engagement mechanism engages with the active engagement mechanism through the passive meshing part. The passive side gear 3 is connected to another of the first buffer and the second buffer.

[0044] In this embodiment, the passive side gear 3 is fixedly connected to the connecting shaft 2, and the passive side gear 3 rotates synchronously with the connecting shaft 2. The passive meshing part is an end face tooth provided on the end face facing the side where the active engagement mechanism is located.

[0045] Preferably, the active side gear 8 is connected to the first buffer member, and the passive side gear 3 is connected to the second buffer member. The first buffer member is a first friction disc 7, and the second buffer member includes an elastic member 5 and a second friction disc 6. The first end of the elastic member 5 is connected to the passive side gear 3, and the elastic member 5 extends along the axial direction of the passive side gear 3. The second friction disc 6 is disposed opposite to the first friction disc 7, and the second friction disc 6 is connected to the second end of the elastic member 5. During the process of the active engagement mechanism moving to the engagement position along the axial direction, the contact between the first friction disc 7 and the second friction disc 6 precedes the engagement between the passive engagement part and the active engagement part.

[0046] In this embodiment, the elastic element 5 enhances the buffering effect of the second buffer. The elastic element 5 is preferably a spring. The second friction disc 6 and the first friction disc 7 are arranged opposite each other. To ensure that the contact between the second friction disc 6 and the first friction disc 7 precedes the engagement between the passive and active engagement portions, the initial position of the second friction disc 6 can be made to protrude beyond the end face where the passive engagement portion is located, i.e., the second friction disc 6 is closer to the active engagement portion than the passive engagement portion. Alternatively, the first friction disc 7 can be made to protrude beyond the end face where the active engagement portion is located, so that the first friction disc 7 is closer to the passive engagement portion than the active engagement portion. Furthermore, the initial position of the second friction disc 6 can also protrude beyond the end face where the active engagement portion is located while simultaneously making the first friction disc 7 protrude beyond the end face where the active engagement portion is located. It should be noted that the method of making the contact between the first friction disc 7 and the second friction disc 6 precede the engagement between the passive and active engagement portions can be replaced by other embodiments with the same implementation effect, all of which are included within the scope of this embodiment.

[0047] Furthermore, the passive side gear 3 has a passive side central shaft 4 extending toward the side where the active engagement mechanism is located, and the second buffer also includes a second sliding sleeve connected to the second friction disc 6. At least a portion of the second sliding sleeve is sleeved on the passive side central shaft 4, and the elastic element 5 is sleeved on the second sliding sleeve and the passive side central shaft 4.

[0048] In this embodiment, by setting the passive side central shaft 4 and setting the elastic element 5 and the second sliding sleeve, the movement direction of the second friction disk 6 is made more stable, avoiding tilting during the movement and causing the second friction disk 6 to lose contact with the first friction disk 7.

[0049] Furthermore, the electric vehicle drivetrain disconnection mechanism also includes a drive mechanism. This drive mechanism drives the active engagement mechanism to slide along the axial direction of the vehicle drive shaft 13. The drive mechanism includes an engagement motor 11 and an engagement transmission component. The input end of the engagement transmission component is connected to the engagement motor 11, and the output end is connected to the active engagement mechanism. The engagement motor controls the engagement transmission component to drive the active engagement mechanism to move along the axial direction of the vehicle drive shaft 13. The drive mechanism facilitates the drive control of the active engagement mechanism, enabling adjustment of its direction and speed of movement.

[0050] Specifically, the drive mechanism includes a drive worm gear 10 and a drive turbine gear 9. The drive worm gear 10 is rigidly connected to the drive motor 11. The drive turbine gear 9 is configured to cooperate with the drive worm gear 10, and the drive worm gear 10 is rigidly connected to the active engagement mechanism. The rotation of the drive motor 11 drives the drive worm gear 10 to rotate, which in turn drives the drive turbine gear 9 to move, thereby driving the active engagement mechanism to move along the axial direction of the vehicle drive shaft 13. The worm gear mechanism can achieve high-precision drive control. Depending on actual needs, the drive mechanism can also be replaced with gear meshing transmission, ball screw transmission, or other drive mechanisms.

[0051] Preferably, the central axis of the connecting shaft 2 and the central axis of the vehicle drive shaft 13 are on the same straight line. This facilitates the symmetrical arrangement of the active and passive engagement mechanisms, which is beneficial for component layout. Depending on actual needs, the central axis of the connecting shaft 2 and the central axis of the vehicle drive shaft 13 can also be parallel but not collinear, or set at a certain angle, as long as the contact between the first and second buffer components precedes the contact between the active and passive engagement mechanisms to achieve engagement buffering.

[0052] The electric vehicle transmission disconnection mechanism in the above embodiments improves the structure of the jaw clutch by adding a first and second buffer as a pre-engagement device inside the jaw clutch. When the jaw clutch engages, the pre-engagement device engages first. As the jaw clutch gradually engages, the pre-engagement device gradually tightens, causing the speed difference between the two ends of the clutch to gradually decrease. Once the speed difference between the two ends of the jaw clutch is lower than a certain value, the jaw clutch engages quickly, thus avoiding engagement shock and increasing engagement speed. At the same time, due to the presence of the pre-engagement device, the accuracy requirements for the drive motor speed control response are reduced, and the difficulty of algorithm development and calibration is reduced. This improves the application effect while reducing the control difficulty.

[0053] According to another specific embodiment of this application, a control method for an electric vehicle drivetrain disconnection mechanism is also provided. The control method is used to control the electric vehicle drivetrain disconnection mechanism of the above embodiment. The electric vehicle includes a main drive motor and a secondary drive motor, the secondary drive motor being the aforementioned drive motor 1, as shown below. Figure 2 As shown, the control method includes the following steps:

[0054] Step S21: Obtain the maximum torque of the main drive motor, the current vehicle speed, the current throttle opening, and the engagement time t;

[0055] Specifically, the duration t is related to the vehicle speed, and the duration t can be a preset value obtained from multiple tests before the vehicle leaves the factory.

[0056] Step S22: Based on the current vehicle speed and current throttle opening, obtain the required driving torque T1 and the torque change rate R1 of the required driving torque;

[0057] It should be understood that the demand-driven torque T1 is the current demand-driven torque. During driving, the vehicle controller obtains the demand-driven torque T1 at the current vehicle speed and throttle pedal opening by looking up a table based on the vehicle speed and throttle pedal opening. The vehicle controller calculates the torque change rate R1 of the demand torque in real time. The specific calculation method is as follows: the vehicle controller performs 10-cycle average filtering on the demand-driven torque T1. The filtered demand-driven torque is T11. In this embodiment, the software execution cycle of the vehicle controller is 10ms. For the filtered demand-driven torque T11, the filtered torque of the current calculation cycle is subtracted from the filtered torque of 10 cycles ago. The torque difference is then divided by the interval time Δt to obtain the torque change rate R1 of the demand-driven torque. In this embodiment, the time corresponding to 10 cycles is 0.1s, that is, Δt is 0.1 seconds.

[0058] Step S23: Based on the demand-driven torque T1 and the torque change rate R1, calculate the demand torque T2 after the combined duration t.

[0059] It should be understood that the required torque T2 is the required torque after the engagement time t. In this embodiment, T2 = T1 + R1 * t.

[0060] Step S24: Based on the required torque T2 and the maximum torque of the main drive motor, determine whether to control the auxiliary drive motor to participate in the drive.

[0061] Specifically, in step S24, when the required torque T2 is greater than the maximum torque of the main drive motor, it is determined that the auxiliary drive motor will participate in driving. When the required torque T2 is less than the maximum torque of the main drive motor * 0.5, and the future required torque T21 after the delay confirmation time t1 is still less than the maximum torque of the main drive motor * 0.5, it is considered that the main drive motor can independently meet the driving requirements of the whole vehicle, and it is determined that the auxiliary drive motor will not participate in driving. The calculation method of the future required torque T21 is similar to the calculation method of the required torque T2.

[0062] Step S25: If it is determined that the auxiliary drive motor participates in the drive, a control instruction set is generated. The control instruction set is used to control the active side gear 8 to move to the engagement position with the passive side gear 3.

[0063] Through steps S21-S25, the required torque T2 after the engagement time t is determined based on the required driving torque T1, the torque change rate R1, and the engagement time t. Then, based on the maximum torque of the main drive motor, it is determined whether to control the auxiliary drive motor to participate in the drive. This allows the auxiliary drive motor to participate in the drive when necessary, avoids energy waste, and makes the control between motors more reasonable.

[0064] Optionally, in step S25, if it is determined that the auxiliary drive motor participates in the drive, a control command set is generated, including:

[0065] Step S251: Obtain the rotational speed V1 of the vehicle drive shaft 13 and the actual rotational speed V2 of the auxiliary drive motor;

[0066] Step S252: When it is determined that the actual rotational speed V2 and the rotational speed V1 meet the first preset condition, a first control instruction is generated in the control instruction set. The first control instruction is used to control the coupled motor 11 to output the first coupled torque T3, so as to drive the active side gear 8 to move toward the side where the passive side gear 3 is located.

[0067] Specifically, the first preset condition is that the deviation between the actual speed V2 and the target speed V1 of the auxiliary drive motor is less than the speed difference threshold ΔV. Combined with the calculation method of torque request T3, the vehicle controller calculates T3 through a closed-loop P algorithm based on the deviation between speed V1 and speed V2. The closed-loop P coefficient is related to the vehicle speed. Different vehicle speeds are selected, and different P coefficients are given at the current vehicle speed. When the passive side gear 3 and the active side gear 8 are in contact, the speed difference between speed V1 and speed V2 is less than 100 rpm. This critical P coefficient is used as the P coefficient at the current speed.

[0068] Through steps S251-S252, during the speed ramp-up phase, the vehicle controller adjusts the speed of the auxiliary drive motor to meet the first preset condition, and then controls the engagement motor 11 to output the first engagement torque T3, so as to drive the active side gear 8 to move toward the side where the passive side gear 3 is located. This can avoid the problem of tooth tipping caused by the excessive speed difference when the active side gear 8 and the passive side gear 3 come into contact, and improve the smoothness of engagement.

[0069] Optionally, in step S25, after the motor 11 outputs the first engagement torque T3, the method further includes:

[0070] Step S253: Obtain the rotational speed V3 of the second friction disk 6; based on the rotational speed V3, calculate the rate of change of rotational speed V3;

[0071] Step S254: When the rotational speed change rate meets the second preset condition, it is determined that the second friction disk 6 and the first friction disk 7 have completed engagement. The current first engagement torque T3 is obtained as the second engagement torque T4. A second control command is generated in the control command set. The second control command is used to control the engagement motor 11 to output the second engagement torque T4 so as to continue to drive the active side gear 8 to move toward the side where the passive side gear 3 is located.

[0072] Specifically, the second preset condition is that the rate of change of rotational speed is greater than 1.2 times the average value of the previous rate of change of rotational speed.

[0073] After entering the synchronization stage through steps S253-S254, the first engagement torque T3 when the rotational speed change rate meets the second preset condition is kept as the second engagement torque T4, which can make the subsequent engagement smoother, so that the active side gear 8 and the passive side gear 3 can rotate synchronously and engage.

[0074] Optionally, in step S25, after the motor 11 outputs the second engagement torque T4, the method further includes:

[0075] Step S255: Obtain the speed difference between the passive side gear 3 and the active side gear 8;

[0076] In step S256, when the speed difference meets the third preset condition, a third control instruction is generated in the control instruction set. The third control instruction is used to control the coupled motor 11 to output the third coupled torque T5 so as to continue to drive the active side gear 8 to move toward the side where the passive side gear 3 is located. When the speed difference meets the fourth preset condition and continues for a preset time, it is determined that the active coupled mechanism and the passive coupled mechanism have been coupled. A fourth control instruction is generated in the control instruction set. The fourth control instruction is used to control the coupled motor 11 to stop outputting torque.

[0077] Preferably, the third engagement torque T5 is twice the second engagement torque T4. When the speeds of the driven side gear 3 and the driving side gear 8 are equal and this engagement is maintained for a duration of t2, it is considered that the driven side gear 3 and the driving side gear 8 are fully engaged. The vehicle controller then resets the torque of the engaging motor to 0. Based on the characteristics of the worm gear, the driven side gear 3 and the driving side gear 8 remain in a continuous meshing state thereafter. The engagement duration t2 is calculated as follows: based on the current rotational speed V1 of the driving side gear 8, the time required for one revolution can be calculated. This time is then divided by the number of teeth of the driving side gear 8 to obtain the time required to rotate one tooth. This time to rotate one tooth is multiplied by 5 to obtain the value of the engagement duration t2.

[0078] Through steps S255-S256, during the engagement stage, the third engagement torque T5 is twice the second engagement torque T4, causing the engagement motor to accelerate immediately, and the passive side gear 3 and the active side gear 8 to engage quickly.

[0079] Optionally, in step S24, determining whether to control the auxiliary drive motor to participate in driving based on the required torque T2 and the maximum torque of the main drive motor further includes the following steps:

[0080] Step S261: When it is determined that the auxiliary drive motor does not participate in the drive, a fifth control command is generated. The fifth control command is used to control the coupling motor 11 to output the separation torque T6 so that the coupling motor 11 rotates in the opposite direction and drives the active coupling mechanism to move from the coupling position to the initial position.

[0081] Preferably, the magnitude of the separation torque T6 is equal to the second engagement torque T4, and the direction of the separation torque T6 is opposite to the direction of the second engagement torque T4.

[0082] Step S262: Obtain the rotational speed of the passive side gear 3;

[0083] In step S263, when the rotational speed of the passive side gear 3 meets the fifth preset condition, a sixth control command is generated. The sixth control command is used to control the coupled motor 11 to stop outputting torque.

[0084] Specifically, the fifth preset condition is that the rotational speed of the passive side gear 3 is less than 10 revolutions. Depending on actual needs, it can also be set to other conditions that can determine that the passive side gear 3 and the active side gear 8 have been completely separated.

[0085] Through steps S261-S263, the engaging motor 11 rotates in the opposite direction, and the active engaging mechanism gradually disengages from the passive engaging mechanism until it is completely disengaged. At this point, the engaging motor 11 stops outputting torque, and the disengaging motor stops rotating.

[0086] According to another specific embodiment of this application, a vehicle is also provided, which has an electric vehicle drivetrain disconnection mechanism, the electric vehicle drivetrain disconnection mechanism being the aforementioned electric vehicle drivetrain disconnection mechanism. The vehicle in this embodiment can be a pure electric vehicle, a hybrid vehicle, or other new energy vehicle.

[0087] According to another specific embodiment of this application, a preferred embodiment of an electric vehicle drivetrain disconnection mechanism and its control method is also provided.

[0088] Specifically, the electric vehicle drivetrain disconnection mechanism consists of a drive motor 1, a connecting shaft 2, a driven side gear 3, a driven side central shaft 4, an elastic element 5, a second friction disc 6, a first friction disc 7, a driving side gear 8, a drive turbine 9, a drive worm gear 10, a connecting motor 11, a first sliding sleeve 12, and a vehicle drive shaft 13. In this embodiment, the elastic element 5 is a spring.

[0089] The torque transmission gear of the passive side gear 3 is located on the side of the gear and is arranged axially; the torque transmission gear of the active side gear 8 is located on the side of the gear and is arranged axially; when the passive side gear 3 and the active side gear 8 are fully meshed, the torque of the drive motor 1 is transmitted to the active side gear 8 through the passive side gear 3, and then to the vehicle drive shaft 13 through the first sliding sleeve 12 of the active side gear 8. The vehicle drive shaft 13 is connected to the input shaft of the vehicle's main reducer, and the power is finally transmitted to the wheels through the main reducer to drive the vehicle forward.

[0090] The connecting shaft 2 is rigidly connected to the driven gear 3. The driven gear 3 and the connecting shaft 2 always rotate at the same speed. The driven central shaft 4 is rigidly connected to the driven gear 3 and rotates at the same speed. The second friction disc 6 has a hollow sliding sleeve (i.e., the aforementioned second sliding sleeve) behind it, which is fitted onto the driven central shaft 4. The hollow sliding sleeve behind the second friction disc 6 can only slide left and right along the driven central shaft 4, and is not allowed to rotate around the driven central shaft 4. That is, the second friction disc 6 rotates at the same speed as the driven gear 3. The spring is located on the second friction disc. Between the second friction disc 6 and the driven gear 3, when the second friction disc 6 is subjected to force to the left, the spring is compressed, and the second friction disc 6 moves to the left along the driven side central axis 4. It should be noted that when the second friction disc 6 and the first friction disc 7 are not in contact, the spring is in a free state. At this time, the end face of the second friction disc 6 is higher than the side end face of the driven gear 3. That is to say, when the driving gear 8 moves to the right and engages with the driven gear 3, the engagement of the second friction disc 6 and the first friction disc 7 is earlier than the engagement of the driving gear 8 and the driven gear 3.

[0091] The active side gear 8 is rigidly connected to the first sliding sleeve 12. The first sliding sleeve 12 is a hollow structure and is fitted on the vehicle drive shaft 13. The first sliding sleeve 12 can only slide left and right along the vehicle drive shaft 13 and cannot rotate around the vehicle drive shaft 13. That is, the active side gear 8 and the vehicle drive shaft 13 rotate at the same speed. The first friction disc 7 is coaxially arranged with the active side gear 8 and is rigidly connected to the active side gear 8. That is, the first friction disc 7 and the active side gear 8 rotate at the same speed.

[0092] The drive turbine 9 is rigidly connected to the active side gear 8. The drive turbine 9 and the drive worm 10 form a worm gear mechanism. The drive worm 10 is rigidly connected to the coupling motor 11. The rotation of the coupling motor 11 drives the drive worm 10 to rotate, which in turn drives the drive turbine 9 to move left and right, which in turn drives the active side gear 8 to move left and right. The drive turbine 9, the drive worm 10 and the coupling motor 11 form a movement control mechanism for the active side gear 8.

[0093] When the motor 11 rotates in the preset direction, it drives the driving gear 8 to move to the left. At the same time, the first friction disk 7 also moves to the left. As mentioned earlier, when the first friction disk 7 moves to the left, it will contact the second friction disk 6. As the first friction disk 7 continues to move to the left, the spring will be compressed. The tighter the spring is compressed, the greater the clamping force provided by the spring to the first friction disk 7 and the second friction disk 6, and the smaller the speed difference between the first friction disk 7 and the second friction disk 6. Since the second friction disk 6 and the driven gear 3 have the same speed, and the first friction disk 7 and the driving gear 8 have the same speed, as the first friction disk 7 and the second friction disk 6 gradually press together, the speeds of the driven gear 3 and the driving gear 8 gradually remain the same.

[0094] The electric vehicle drivetrain disconnection mechanism in this embodiment is mainly applied to new energy vehicles with four-wheel drive configurations, namely, a drive motor on each of the front and rear axles. One of the drive motors is kept in real time connected to the drivetrain, and this motor is called the main drive motor; the other drive motor on the axle is disconnected from the drivetrain through the disconnection mechanism described in this embodiment when the overall vehicle drive force demand is not high. This drive motor maintains a 0 torque state and is called the auxiliary drive motor. In this embodiment, drive motor 1 is the auxiliary drive motor.

[0095] Step S1: The engagement time t of the transmission system disconnection mechanism described in this embodiment at different vehicle speeds is determined through experiments. During driving, the vehicle controller obtains the required driving torque T1 at the current vehicle speed and throttle pedal opening by looking up a table based on the vehicle speed and throttle pedal opening. The vehicle controller calculates the torque change rate R1 of the required torque in real time. Based on the current required driving torque T1 and the torque change rate R1 of the current required torque, the vehicle controller calculates the required torque T2 after engagement time t. The calculation method is T2 = T1 + R1 * t.

[0096] The calculation method for the torque change rate R1 of the demand-driven torque is as follows: The vehicle controller performs 10-cycle average filtering on the demand-driven torque T1, and the filtered demand-driven torque is T11. In this embodiment, the software execution cycle of the vehicle controller is 10ms. For the filtered demand-driven torque T11, the filtered torque of the current calculation cycle is subtracted from the filtered torque of 10 cycles ago, and the torque difference is divided by the interval time Δt to obtain the torque change rate R1 of the demand-driven torque. In this embodiment, the time corresponding to 10 cycles is 0.1s, that is, Δt is 0.1 seconds.

[0097] Step S2: The auxiliary drive motor intervention flag ClutchEngag is calculated. When the required torque T2 calculated by the vehicle controller exceeds the maximum torque of the main drive motor, it is considered that the main drive motor alone cannot fully meet the vehicle's power requirements. Therefore, the ClutchEngag flag is set (set to 1), meaning the auxiliary drive motor needs to participate in driving, and the disconnection device in this embodiment needs to be engaged. When the required torque T2 calculated by the vehicle controller is less than the maximum torque of the main drive motor * 0.5, and the future required torque T21 after a delay confirmation time t1 is still less than the maximum torque of the main drive motor * 0.5, it is considered that the main drive motor can independently meet the vehicle's driving requirements, the auxiliary drive motor can be disengaged from the transmission system, the disconnection device in this embodiment needs to be disengaged, and the ClutchEngag flag is reset (set to 0). The calculation method for the future required torque T21 can be derived from the calculation method for the required torque T2.

[0098] The purpose of setting the delayed confirmation time t1 is that the driver's required torque fluctuates randomly. By delaying the confirmation time t1, the frequent setting and resetting of the ClutchEngag flag can be avoided, thereby avoiding frequent engagement and disengagement of the disconnection device in this embodiment.

[0099] Step S3: After the ClutchEngag flag is set, it is necessary to control the engagement of the disconnection mechanism in this embodiment. The specific engagement process control method includes:

[0100] In step S31, before the disconnection device is engaged, the drive motor 1 (i.e., the auxiliary drive motor) is stationary at 0 speed. Since the vehicle drive shaft 13 is connected to the wheel drive shaft, the speed of the drive shaft 13 can be obtained by calculating the speed ratio based on the wheel speed on the drive shaft. According to the aforementioned connection relationship, the speed of the active side gear 8 is also equal to V1. When the disconnection device needs to be engaged, the speed increase stage of the passive side gear 3 and the active side gear 8 is entered. The vehicle controller needs to control the speed of the auxiliary drive motor at the target speed V1. The vehicle controller detects the actual speed V2 of the auxiliary drive motor and compares it with the target speed V1. It obtains the torque request to the auxiliary drive motor through the PI closed-loop control algorithm. After receiving the requested torque from the vehicle controller, the auxiliary drive motor controller responds and executes the requested torque from the vehicle controller.

[0101] Step S32: When the deviation between the actual speed V2 and the target speed V1 of the auxiliary drive motor is less than the speed difference threshold ΔV, the vehicle controller sends a engagement torque request T3 to the engagement motor 11. The engagement motor 11 receives the torque T3 and executes it, then the engagement motor starts to rotate. According to the worm gear principle, at the same time as the engagement motor starts to rotate, the driving side gear 8 begins to move to the left, entering the speed ramp-up stage. Figure 3 As shown.

[0102] The calculation method for torque request T3 is as follows: The vehicle controller calculates T3 based on the deviation between speed V1 and speed V2 using a closed-loop P algorithm. The closed-loop P coefficient is related to the vehicle speed. Different vehicle speeds are selected, and different P coefficients are given at the current vehicle speed. When the passive side gear 3 contacts the active side gear 8, the speed difference between speed V1 and speed V2 is less than 100 rpm. This critical P coefficient is used as the P coefficient at the current speed.

[0103] Step S33: When the driving gear 8 moves to the left until the first friction disc 7 begins to contact the second friction disc 6, friction is generated when they come into contact due to the speed difference between them. This friction is applied to both the first and second friction discs simultaneously. For the second friction disc 6, the friction causes it to rotate faster (because the speed of the first friction disc 7 is greater than that of the second friction disc 6). The vehicle controller monitors the rate of change of the speed V2 of the second friction disc 6 (obtained by differentiating the speed V2). When the rate of change is greater than 1.2 times the average of the previous rates of change, it is considered that the first friction disc 7 and the second friction disc 6 have completed their engagement, and the synchronization stage between the driven gear 3 and the driving gear 8 begins. Figure 4 As shown;

[0104] After entering the synchronization stage between the passive side gear 3 and the active side gear 8, the vehicle controller keeps the engaged motor torque unchanged at the current value, which is defined as T4.

[0105] Step S34: When the vehicle control detects that the speed difference between the passive side gear 3 and the active side gear 8 is less than 20 rpm, it enters the engagement stage between the passive side gear 3 and the active side gear 8, as follows: Figure 5 As shown;

[0106] During this phase, the vehicle controller doubles the torque of the engaging motor from the initial torque value T4, meaning the current torque T5 is twice the holding torque T4 before entering this phase. Under the action of this torque T5, the engaging motor immediately accelerates, and the driven gear 3 and the driving gear 8 quickly engage. When the speeds of the driven gear 3 and the driving gear 8 are equal and this is confirmed for a duration t2, it is considered that the driven gear 3 and the driving gear 8 are fully engaged. The vehicle controller then resets the torque of the engaging motor to 0. Based on the characteristics of the worm gear, the driven gear 3 and the driving gear 8 remain in a continuously meshed state thereafter. Figure 6 As shown;

[0107] The confirmation time t2 is calculated as follows: based on the current rotational speed V1 of the active side gear 8, the time required for it to rotate one revolution can be calculated, and then divided by the number of teeth of the active side gear 8 to obtain the time required to rotate one tooth. This time to rotate one tooth is multiplied by 5 to obtain the value of the confirmation time t2.

[0108] Step S4: After the ClutchEngag flag is reset, the disconnection mechanism described in this embodiment needs to be controlled to separate. The specific separation process control method is as follows:

[0109] In step S41, since the auxiliary drive motor was already in a 0 torque follow-up state before the disconnection structure was separated, the vehicle controller sent a value of T6 = -1 * T4 to the disconnect motor. The disconnect motor then quickly reversed, and the active side gear 8 quickly moved to the right. After the speed of the passive side gear 3 was less than 10 revolutions, it was considered that the passive side gear 3 and the active side gear 8 had been completely separated. Subsequently, the vehicle controller sent a 0 torque request to the disconnect motor, and the disconnect motor stopped rotating.

[0110] In the above embodiment, a friction mechanism (i.e., a first friction disc 7 and a second friction disc 6) is respectively provided inside the active side gear 8 and the passive side gear 3. The friction mechanism inside the passive side gear 3 is supported by a spring. In the natural state of the spring, the outer side of the second friction disc 6 protrudes beyond the end face of the passive side gear 3. This allows the engagement of the first friction disc 7 and the second friction disc 6 to occur earlier than the engagement of the active side gear 8 and the passive side gear 3 during the engagement process. As the jaw clutch is gradually engaged, the friction mechanism is gradually tightened, causing the speed difference between the two ends of the clutch to gradually decrease. Once the speed difference between the two ends of the jaw clutch is lower than a certain value, the jaw clutch engages quickly, avoiding engagement impact and increasing engagement speed. At the same time, due to the presence of the friction mechanism, the accuracy requirements for the drive motor speed control response are reduced, and the difficulty of algorithm development and calibration is reduced. This improves the application effect while reducing the control difficulty.

[0111] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0112] In addition to the above, it should be noted that the terms "one embodiment," "another embodiment," and "embodiment" used in this specification refer to specific features, structures, or characteristics described in connection with that embodiment, which are included in at least one embodiment described in the general description of this application. The appearance of the same expression in multiple places in the specification does not necessarily refer to the same embodiment. Furthermore, when a specific feature, structure, or characteristic is described in connection with any embodiment, the intention is to suggest that implementing such a feature, structure, or characteristic in conjunction with other embodiments also falls within the scope of this invention.

[0113] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0114] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A drivetrain disconnection mechanism for an electric vehicle, characterized in that, include: A passive coupling mechanism is fixedly connected to the connecting shaft (2) of the drive motor (1), and the passive coupling mechanism rotates synchronously with the connecting shaft (2); An active engagement mechanism is connected to a vehicle drive shaft (13), which is connected to the input shaft of the vehicle's main reducer. The active engagement mechanism rotates synchronously with the vehicle drive shaft (13), and is slidably arranged along the axial direction of the vehicle drive shaft (13). The first buffer component is fixedly connected to either the active engagement mechanism or the passive engagement mechanism. The second buffer is elastically connected to another of the active engagement mechanism and the passive engagement mechanism; The active engagement mechanism has an initial position away from the passive engagement mechanism and an engagement position with the passive engagement mechanism. During the process of the active engagement mechanism moving to the engagement position along the axial direction, the contact between the first buffer and the second buffer occurs before the contact between the active engagement mechanism and the passive engagement mechanism. The active engagement mechanism includes: The first sliding sleeve (12) is sleeved on the vehicle drive shaft (13). The first sliding sleeve (12) is slidably arranged along the axial direction of the vehicle drive shaft (13). The first sliding sleeve (12) rotates synchronously with the vehicle drive shaft (13). Active side gear (8) is fixedly connected to the first sliding sleeve (12). An active meshing part is provided on the end face of the active side gear (8) facing the passive engagement mechanism. The active engagement mechanism engages with the passive engagement mechanism through the active meshing part. The active side gear (8) is connected to either the first buffer or the second buffer. The passive coupling mechanism includes: A passive side gear (3) is fixedly connected to the connecting shaft (2). A passive engagement part is provided on the end face of the passive side gear (3) facing the active engagement mechanism. The passive engagement mechanism is engaged with the active engagement mechanism through the passive engagement part. The passive side gear (3) is connected to the other of the first buffer and the second buffer.

2. The electric vehicle drivetrain disconnection mechanism according to claim 1, characterized in that, The active side gear (8) is connected to the first buffer, and the passive side gear (3) is connected to the second buffer. The first buffer is a first friction disc (7), and the second buffer includes: An elastic element (5) is provided, the first end of which is connected to the passive side gear (3), and the elastic element (5) extends along the axial direction of the passive side gear (3). The second friction disc (6) is disposed opposite to the first friction disc (7), and the second friction disc (6) is connected to the second end of the elastic member (5); During the process of the active engagement mechanism moving axially to the engagement position, the contact between the first friction disc (7) and the second friction disc (6) precedes the engagement between the passive engagement part and the active engagement part.

3. The electric vehicle drivetrain disconnection mechanism according to claim 2, characterized in that, The passive side gear (3) has a passive side central shaft (4) extending toward the side where the active engagement mechanism is located, and the second buffer also includes: The second sliding sleeve is connected to the second friction disc (6), and at least part of the second sliding sleeve is sleeved on the passive side central shaft (4). The elastic element (5) is sleeved on the second sliding sleeve and the passive side central shaft (4).

4. The electric vehicle drivetrain disconnection mechanism according to claim 1, characterized in that, The electric vehicle drivetrain disconnect mechanism further includes a drive mechanism for driving the active engagement mechanism to slide along the axial direction of the vehicle drive shaft (13). The drive mechanism includes: Combined with motor (11); The input end of the combined transmission component is connected to the combined motor (11), and the output end of the combined transmission component is connected to the active combined mechanism. The combined motor drives the active combined mechanism to move along the axial direction of the vehicle drive shaft (13) by controlling the combined transmission component.

5. The electric vehicle drivetrain disconnection mechanism according to claim 4, characterized in that, The connecting transmission component includes: A drive worm (10) is rigidly connected to the combined motor (11); A drive turbine (9) is configured to cooperate with the drive worm (10), and the drive worm (10) is rigidly connected to the active engagement mechanism; The rotating motor (11) drives the drive worm (10) to rotate, and the drive worm (10) drives the drive turbine (9) to move, thereby driving the active engagement mechanism to move along the axial direction of the vehicle drive shaft (13).

6. The electric vehicle drivetrain disconnection mechanism according to claim 1, characterized in that, The central axis of the connecting shaft (2) is on the same straight line as the central axis of the vehicle drive shaft (13).

7. A control method for a disconnection mechanism of an electric vehicle transmission system, characterized in that, The control method is used to control the electric vehicle transmission system disconnection mechanism according to any one of claims 1-6, the electric vehicle including a main drive motor and a secondary drive motor, the secondary drive motor being the drive motor (1) according to any one of claims 1-6, and the control method includes the following steps: Obtain the maximum torque of the main drive motor, the current vehicle speed, the current throttle opening, and the engagement time t; Based on the current vehicle speed and current throttle opening, the required driving torque T1 and the torque change rate R1 of the required driving torque are obtained. Based on the demand-driven torque T1 and the torque change rate R1, calculate the demand torque T2 after the combined duration t. Based on the required torque T2 and the maximum torque of the main drive motor, determine whether to control the auxiliary drive motor to participate in the drive; When it is determined that the auxiliary drive motor participates in the drive, a control instruction set is generated, which is used to control the active side gear (8) to move to the engagement position where it engages with the passive side gear (3).

8. The control method according to claim 7, characterized in that, If it is determined that the auxiliary drive motor participates in the drive, a set of control instructions is generated, including: Obtain the rotational speed V1 of the vehicle drive shaft (13) and the actual rotational speed V2 of the auxiliary drive motor; When it is determined that the actual rotational speed V2 and the rotational speed V1 meet the first preset condition, a first control instruction is generated in the control instruction set. The first control instruction is used to control the motor (11) to output a first engagement torque T3, so as to drive the active side gear (8) to move toward the side where the passive side gear (3) is located.

9. The control method according to claim 8, characterized in that, After the combined motor (11) outputs the first combined torque T3, the method further includes: Obtain the rotational speed V3 of the second friction disc (6); Based on the rotational speed V3, calculate the rate of change of rotational speed V3; When the rotational speed change rate meets the second preset condition, it is determined that the second friction disk (6) and the first friction disk (7) have completed the engagement, the current first engagement torque T3 is obtained as the second engagement torque T4, and the second control instruction in the control instruction set is generated. The second control instruction is used to control the engagement motor (11) to output the second engagement torque T4 so as to continue to drive the active side gear (8) to move toward the side where the passive side gear (3) is located.

10. The control method according to claim 9, characterized in that, After the combined motor (11) outputs the second combined torque T4, the method further includes: Obtain the speed difference between the passive side gear (3) and the active side gear (8); When the speed difference meets the third preset condition, a third control instruction is generated in the control instruction set. The third control instruction is used to control the combined motor (11) to output a third combined torque T5 so as to continue to drive the active side gear (8) to move toward the side where the passive side gear (3) is located. When the speed difference meets the fourth preset condition and lasts for a preset duration, it is determined that the active engagement mechanism and the passive engagement mechanism have completed engagement, and a fourth control instruction in the control instruction set is generated. The fourth control instruction is used to control the engaged motor (11) to stop outputting torque.

11. The control method according to claim 10, characterized in that, Based on the required torque T2 and the maximum torque of the main drive motor, determining whether to control the auxiliary drive motor to participate in the drive also includes the following steps: When it is determined that the auxiliary drive motor does not participate in the drive, a fifth control command is generated. The fifth control command is used to control the combined motor (11) to output the separation torque T6 so that the combined motor (11) rotates in the opposite direction and drives the active combined mechanism to move from the combined position to the initial position. Obtain the rotational speed of the passive side gear (3); When the rotational speed of the passive side gear (3) meets the fifth preset condition, a sixth control command is generated, which is used to control the combined motor (11) to stop outputting torque.

12. A vehicle, characterized in that, The vehicle has an electric vehicle drivetrain disconnection mechanism, which is the electric vehicle drivetrain disconnection mechanism according to any one of claims 1-6.

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