Vehicle electromagnetic clutch disengagement method

Abstract

The invention discloses a vehicle electromagnetic clutch disengagement method which comprises the following steps: S1, at the beginning, a vehicle is in a high-speed parallel running state; an engine module and a generator module of the vehicle are connected through an intermediate transmission module, an electromagnetic clutch is installed on the intermediate transmission module, the intermediate transmission module is connected with an output module, and the output module is further connected with a driving motor module. S2, the vehicle runs in parallel at a high speed, and the VCU recognizes that a driver steps on an accelerator pedal at the opening degree of more than 50%; s3, the VCU starts a clutch disengagement process; s4, clutch disconnection judgment is carried out, and if the clutch is not disconnected, the VCU is returned to start the clutch disconnection process; otherwise, the clutch is disengaged.

Description

Technical Field

[0001] The invention belongs to the technical field of vehicle clutches, and in particular relates to a method for disengaging a vehicle electromagnetic clutch. Background Art

[0002] The current electromagnetic clutch control strategy generally adopts the method of engine zero torque control and superimposed generator jitter. In the current control strategy, due to the engine zero torque control, the generator cannot realize the power generation function during the clutch disengagement. When the power battery SOC is low, the power request of the drive motor cannot be fully met, which in turn affects the high-speed re-acceleration performance. When the clutch is disengaged, the whole vehicle switches to series drive mode, supplying additional power to the drive motor, which will cause the problem of abrupt power response.

[0003] The existing technical solutions have patent numbers: CN202211352428.3, CN202311454036.2, and CN202410279197.0. The above three solutions all perform a "torque unloading" operation on the engine when the clutch is disengaged, which affects the acceleration performance and causes problems with power output changes.

[0004] In the existing solution, an electromagnetic clutch is used to connect the air pump (external). The electromagnetic clutch is a "dry clutch". Generally, a "dry clutch" refers to a friction plate clutch, which may cause a risk of not being able to disengage when transmitting torque. Summary of the invention

[0005] The purpose of the present invention is to solve the above problems and provide a method for disengaging a vehicle electromagnetic clutch which can disengage the clutch under load and ensure the high-speed re-acceleration performance of the whole vehicle.

[0006] In order to solve the above technical problems, the technical solution of the present invention is: a method for disengaging an electromagnetic clutch for a vehicle, comprising the following steps:

[0007] S1. At the beginning, the vehicle is in a high-speed parallel driving state; the engine module and the generator module of the vehicle are connected through the intermediate transmission module, the electromagnetic clutch is installed on the intermediate transmission module, the intermediate transmission module is connected to the output module, and the output module is also connected to the drive motor module;

[0008] S2: The vehicles are traveling in parallel at high speed, and the VCU recognizes that the driver has stepped on the accelerator pedal with an opening of more than 50%;

[0009] S3, VCU starts the clutch disengagement process;

[0010] S4: Clutch disconnection judgment: if the clutch is not disconnected, return to VCU to start the clutch disengagement process; otherwise, the clutch is disengaged.

[0011] Furthermore, the engine module includes an engine, the generator module includes a generator, and the drive motor module includes a drive motor. The engine, generator and drive motor all have two modes: torque control and speed control. The torque control is to output the corresponding torque according to the command torque target value; the speed control is to output the corresponding torque according to the command speed target to balance the torque load.

[0012] Furthermore, when the vehicle is in a high-speed parallel driving state in S1, the engine of the engine module is the main drive, that is, the engine works in a torque control state, and the power of the engine is transmitted to the wheels via the electromagnetic clutch to drive the vehicle. The torque is output according to the throttle opening of the vehicle. The generator and the drive motor are both torque controlled, and both the generator and the drive motor output T k Small torque relies on the teeth, the coil of the electromagnetic clutch remains powered, and the clutch remains engaged.

[0013] Furthermore, after the accelerator pedal is depressed in S2, the vehicle is in the range-extending state, and according to the current speed and the power following curve, the output torque T ice The engine is in torque control state, and the generator is in power generation state, that is, speed control state. According to the speed ratio conversion and loss compensation, the engine torque T is balanced. gm =T ice i-loss: The drive motor is in the main drive state and outputs torque T according to the throttle opening. tm ; The electromagnetic clutch is in the engaged state, that is, the coil remains powered and the clutch remains engaged.

[0014] Furthermore, the extended-range state refers to when the vehicle's electromagnetic clutch is in an engaged state. In order to ensure that there is no torque on the shaft corresponding to the electromagnetic clutch, a generator is used to balance the torque of the engine to avoid the electromagnetic clutch's teeth being difficult to disconnect due to the torque; the engine drives the generator to generate electricity, and the generated electricity is supplied to the drive motor. The drive motor is torque-controlled, and the output drives the wheels to rotate.

[0015] Furthermore, when the clutch disengagement process is started in S3, the engine is in the range-extending state, following the torque request of the drive motor, and outputs the torque T ice ; The generator is in the power generation state, and the sinusoidal signal T is superimposed on the balanced engine torque gm =T ice i-loss+T z ·sinωt,T z ·sinωt is a superimposed sinusoidal torque fluctuation, which compensates for the possible torque difference between the engine and the generator, and continuously creates opportunities for the torque of the clutch shaft to "cross the zero point", thereby ensuring that the clutch can be disengaged at the moment the clutch shaft crosses the zero point; the drive motor is in the main drive state, and the output torque T is based on the throttle opening tm; The electromagnetic clutch is in the power-off state, the coil is powered off, and the electromagnetic clutch has a disengagement tendency under the action of the return spring. If it fails to disengage successfully, continue to try to disengage; if it has already disengaged, go to the next step.

[0016] Furthermore, when the electromagnetic clutch is disengaged under the action of the return spring, a disengagement trend judgment is performed, and the judgment is made by judging the position of the engaging teeth through the signal of the position sensor to determine whether the disengagement is successful.

[0017] Furthermore, after the clutch is disconnected in S4, the engine is in the range-extending state, and outputs torque T according to the power following curve according to the power demand of the drive motor. ice ; The generator is in the power generation state. According to the power demand of the drive motor, the output speed N follows the power following curve gm ; The drive motor is in the main drive state and outputs torque T according to the throttle opening tm ; The electromagnetic clutch is in the disengaged state, the coil is powered off, and the clutch remains in the disengaged state.

[0018] The beneficial effects of the present invention are:

[0019] 1. The electromagnetic clutch disengagement method for a vehicle provided by the present invention realizes the clutch disengagement with load, ensures the high-speed re-acceleration performance of the whole vehicle, and avoids the problem of power response change.

[0020] 2. The present invention does not require adjustment of the mechanical structure. Through the optimization of the control strategy, the engine will not unload torque during the clutch disconnection period, and the generator will remain in the power generation state, ensuring the power supply of the drive motor under low SOC conditions and the consistency of the driver's acceleration experience.

[0021] 3. The present invention is applied to a hybrid transmission equipped with an electromagnetic tooth clutch to achieve series-parallel switching during vehicle acceleration without adjusting the electromagnetic clutch or other components in the hybrid transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a flow chart of a method for disengaging a vehicle electromagnetic clutch according to the present invention;

[0023] Figure 2 It is a system architecture diagram of the hybrid transmission of the present invention.

[0024] Explanation of the accompanying drawings: 1. Engine module; 2. Generator module; 3. Electromagnetic clutch; 4. Output module; 5. Drive motor module; 11. Engine; 12. Engine driving gear; 21. Generator; 22. Generator gear; 31. Drive shaft; 33. First transmission gear; 34. Second transmission gear; 35. Third transmission gear; 41. Output gear; 42. Output shaft; 51. Drive motor; 52. First gear of drive motor; 53. Second gear of drive motor; 54. Drive motor transmission shaft; 55. Third gear of drive motor. DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments:

[0026] like Figure 1 to Figure 2 As shown, the present invention provides a method for disengaging a vehicle electromagnetic clutch, comprising the following steps:

[0027] S1. At the beginning, the vehicle is in a high-speed parallel driving state; the vehicle's engine module 1 and generator module 2 are connected through an intermediate transmission module, the electromagnetic clutch 3 is installed on the intermediate transmission module, the intermediate transmission module is connected to the output module 4, and the output module 4 is also connected to the drive motor module 5.

[0028] In step S1, the engine module 1 includes an engine 11 and an engine driving gear 12, and the engine driving gear 12 is sleeved on the rotating shaft of the engine 11. The generator module 2 includes a generator 21 and a generator gear 22, and the generator gear 22 is sleeved on the rotating shaft of the generator 21. The output module 4 includes an output gear 41 and an output shaft 42, and the output gear 41 is sleeved on the output shaft 42. The drive motor module 5 includes a drive motor 51, a first drive motor gear 52, a second drive motor gear 53, a drive motor transmission shaft 54 ​​and a third drive motor gear 55. The rotating shaft end of the drive motor 51 is penetrated by the first drive motor gear 52, the first drive motor gear 52 is meshed with the second drive motor gear 53, the second drive motor gear 53 and the third drive motor gear 55 are both sleeved on the drive motor transmission shaft 54, and the output gear 41 is respectively meshed with the third transmission gear 35 and the third drive motor gear 55.

[0029] The engine 11, the generator 21 and the drive motor 51 all have two modes: torque control and speed control. The torque control is to output the corresponding torque according to the command torque target value; the speed control is to output the corresponding torque according to the command speed target to balance the torque load.

[0030] The intermediate transmission module includes a transmission shaft 31 , on which an electromagnetic clutch 3 , a first transmission gear 33 , a second transmission gear 34 and a third transmission gear 35 are sleeved. The second transmission gear 34 is connected to the first transmission gear 33 , and the electromagnetic clutch 32 is located between the second transmission gear 34 and the third transmission gear 35 .

[0031] The first transmission gear 33 meshes with the generator gear 22, and the second transmission gear 34 meshes with the engine driving gear 12. The electromagnetic clutch 3 is controlled to be connected to or separated from the first transmission gear 33, so as to realize the rotation and stop of the control transmission shaft 31, and then realize the motion control of the third transmission gear 35. The third transmission gear 35 meshes with the output gear 41, and when the third transmission gear 35 rotates, it drives the output gear 41 to rotate, and then drives the output shaft 42 to rotate.

[0032] In step S1, when the vehicle is in a high-speed parallel driving state, the engine 11 of the engine module 1 is the main drive, that is, the engine 11 works in a torque control state, and the power of the engine 11 is transmitted to the wheels through the electromagnetic clutch 3 to drive the vehicle to travel. The torque is output according to the throttle opening of the vehicle. The generator 21 and the drive motor 51 are both torque controlled, and the generator 21 and the drive motor 51 both output T k Small torque relies on the gears, the coil of the electromagnetic clutch 3 remains powered, and the clutch remains engaged.

[0033] In step S1, when the vehicle is in a high-speed parallel driving state, the engine 11 is the main drive and outputs torque according to the vehicle throttle opening. The generator 21 and the drive motor 51 are both torque controlled. k Small torque relies on the gears, the coil of the electromagnetic clutch 32 remains powered on, and the clutch remains engaged. In this embodiment, the electromagnetic clutch 3 is an existing mature device.

[0034] S2: The vehicles are traveling in parallel at high speed, and the VCU recognizes that the driver has stepped on the accelerator pedal with an opening of more than 50%.

[0035] After the accelerator pedal is depressed in step S2, the vehicle is in the range-extending state, and according to the current speed and the power following curve, the output torque T ice The engine is in torque control state, the generator 21 is in power generation state, that is, speed control state, according to the speed ratio conversion and loss compensation, the engine torque T is balanced gm =T ice ·i-loss; the drive motor 51 is in the main drive state, and outputs torque T according to the throttle opening tm ; The electromagnetic clutch 3 is in the engaged state, that is, the coil remains powered and the clutch remains engaged.

[0036] The extended range state refers to when the electromagnetic clutch 3 of the vehicle is in the engaged state. In order to make the shaft corresponding to the electromagnetic clutch 3 free of torque, a generator is used to balance the torque of the engine to avoid the electromagnetic clutch 3 being difficult to disconnect due to torque; the engine 11 drives the generator 21 to generate electricity, and the generated electricity is supplied to the drive motor 51. The drive motor 51 is torque controlled and outputs the drive wheels to operate. In this embodiment, when the electromagnetic clutch 3 is still connected, it means that the electromagnetic clutch 3 is connected to the second transmission gear 34.

[0037] S3, VCU starts the clutch disengagement process.

[0038] When the clutch disengagement process is started in step S3, the engine 11 is in the range-extending state, following the drive motor torque request, and outputs the torque T ice Generator 21 is in power generation state, and the sinusoidal signal T is superimposed on the balanced engine torque gm =T ice i-loss+T z ·sinωt,T z ·sinωt is a superimposed sinusoidal torque fluctuation, which compensates for the torque difference between the engine and the generator, and continuously creates the opportunity for the torque of the clutch shaft to "cross the zero point", thereby ensuring that the clutch can be disengaged at the moment when the clutch shaft crosses the zero point; the drive motor 51 is in the main drive state, and outputs the torque T according to the throttle opening. tm ; The electromagnetic clutch 3 is in the power-off state, the coil is powered off, and the electromagnetic clutch 3 has a disengagement trend under the action of the return spring. If it fails to disengage successfully, continue to try to disengage; if it has already disengaged, proceed to the next step.

[0039] When the electromagnetic clutch 3 is disengaged under the action of the return spring, a disengagement trend judgment is performed. The judgment is made by judging the position of the engaging teeth through the signal of the position sensor to determine whether the disengagement is successful.

[0040] S4: Clutch disconnection judgment: if the clutch is not disconnected, return to VCU to start the clutch disengagement process; otherwise, the clutch is disengaged.

[0041] After the clutch is disconnected in S4, the engine 11 is in the range-extending state, and outputs torque T according to the power following curve according to the power demand of the driving motor. ice The generator 21 is in the power generation state, and outputs the speed N according to the power following curve according to the power demand of the driving motor. gm The driving motor 51 is in the main driving state and outputs torque T according to the throttle opening. tm ; The electromagnetic clutch 32 is in the disengaged state, the coil is powered off, and the clutch remains in the disengaged state.

[0042] Those skilled in the art will appreciate that the embodiments described herein are intended to help readers understand the principles of the present invention, and should be understood that the protection scope of the present invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific variations and combinations that do not deviate from the essence of the present invention based on the technical revelations disclosed by the present invention, and these variations and combinations are still within the protection scope of the present invention.

Claims

1. A method for disengaging a vehicle electromagnetic clutch, characterized in that: The following steps are involved: S1. At the beginning, the vehicle is in a high-speed parallel driving state; the engine module (1) and the generator module (2) of the vehicle are connected via an intermediate transmission module, the electromagnetic clutch (3) is installed on the intermediate transmission module, the intermediate transmission module is connected to the output module (4), and the output module (4) is also connected to the drive motor module (5); S2: The vehicles are traveling in parallel at high speed, and the VCU recognizes that the driver has stepped on the accelerator pedal with an opening of more than 50%; S3, VCU starts the clutch disengagement process; S4: Clutch disconnection judgment: if the clutch is not disconnected, return to VCU to start the clutch disengagement process; otherwise, the clutch is disengaged.

2. A method for disengaging a vehicle electromagnetic clutch according to claim 1, characterized in that: The engine module (1) includes an engine (11), the generator module (2) includes a generator (21), and the drive motor module (5) includes a drive motor (51). The engine (11), the generator (21) and the drive motor (51) all have two modes: torque control and speed control. The torque control is to output a corresponding torque according to a command torque target value. Speed ​​control is to output the corresponding torque according to the command speed target and balance the torque load.

3. A method for disengaging a vehicle electromagnetic clutch according to claim 1, characterized in that: When the vehicle is in a high-speed parallel driving state in S1, the engine (11) of the engine module (1) is the main drive, that is, the engine (11) works in a torque control state, and the power of the engine (11) is transmitted to the wheels via the electromagnetic clutch (3) to drive the vehicle to travel. The torque is output according to the throttle opening of the vehicle. The generator (21) and the drive motor (51) are both torque controlled, and the generator (21) and the drive motor (51) both output T k The small torque relies on the gears, the coil of the electromagnetic clutch (3) remains powered, and the clutch remains engaged.

4. A method for disengaging a vehicle electromagnetic clutch according to claim 1, characterized in that: After the accelerator pedal is depressed in S2, the vehicle is in the range-extending state, and according to the current speed and the power following curve, the output torque T ice The engine is in torque control state, the generator (21) is in power generation state, that is, speed control state, according to the speed ratio conversion and loss compensation, the engine torque T is balanced gm =T ice ·i-loss; the drive motor (51) is in the main drive state, and outputs torque T according to the throttle opening tm ; The electromagnetic clutch (3) is in the engaged state, that is, the coil remains powered and the clutch remains engaged.

5. A method for disengaging a vehicle electromagnetic clutch according to claim 4, characterized in that: The extended-range state refers to when the electromagnetic clutch (3) of the vehicle is in an engaged state. In order to prevent the shaft corresponding to the electromagnetic clutch (3) from having no torque, a generator is used to balance the torque of the engine to avoid the electromagnetic clutch (3) being difficult to disconnect due to the torque; the engine (11) drives the generator (21) to generate electricity, and the generated electricity is supplied to the drive motor (51). The drive motor (51) is torque-controlled and outputs a drive wheel to rotate.

6. A method for disengaging a vehicle electromagnetic clutch according to claim 1, characterized in that: When the clutch disengagement process is started in S3, the engine (11) is in the range-extending state, following the torque request of the drive motor, and outputting the torque T ice The generator (21) is in the power generation state, and the sinusoidal signal T is superimposed on the balanced engine torque. gm =T ice i-loss+T z ·sinωt,T z sinωt is a superimposed sinusoidal torque fluctuation, which compensates for the torque difference between the engine and the generator, and continuously creates opportunities for the torque of the clutch shaft to "cross the zero point", thereby ensuring that the clutch can be disengaged at the moment when the clutch shaft crosses the zero point; the drive motor (51) is in the main drive state, and outputs the torque T according to the throttle opening. tm ; The electromagnetic clutch (3) is in the power-off state, the coil is powered off, and the electromagnetic clutch (3) has a disengagement tendency under the action of the return spring. If the disengagement fails, the disengagement attempt continues; If it is already disengaged, proceed to the next step.

7. A method for disengaging a vehicle electromagnetic clutch according to claim 1, characterized in that: When the electromagnetic clutch (3) is disengaged under the action of the return spring, a disengagement trend judgment is performed. The judgment is made by judging the position of the engaging teeth through the signal of the position sensor to determine whether the disengagement is successful.

8. A method for disengaging a vehicle electromagnetic clutch according to claim 1, characterized in that: After the clutch is disconnected in S4, the engine (11) is in the range-extending state, and outputs torque T according to the power following curve according to the power demand of the driving motor. ice The generator (21) is in the power generation state, and according to the power demand of the drive motor, the output speed N follows the power following curve gm The drive motor (51) is in the main drive state, and outputs torque T according to the throttle opening tm ; The electromagnetic clutch (32) is in the disengaged state, the coil is powered off, and the clutch remains in the disengaged state.

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