A gear shifting method for a gearbox to shift into gear, an electronic device and an automobile based on a pneumatic switch valve group shifting control mechanism

Abstract

The present invention discloses a gear shifting method for a gearbox to shift into gear based on a pneumatic switch valve group shifting control mechanism, an electronic device, and an automobile, which relates to the technical field of new energy vehicles. The method includes: pre-dividing the gear shifting stage according to the theoretical gear shifting dimension chain and calibrating the demarcation points of each stage; obtaining the fork displacement value and the fork movement rate, calibrating the valve group enabling and duty cycle size of each stage according to the fork displacement and the fork movement rate, and judging whether the fork shifting force meets the expected threshold; obtaining the target gear position and the input shaft rotation speed rate, compensating the driving motor torque according to the target gear position and the input shaft rotation speed rate, and judging whether the speed synchronization meets the expected threshold; if the fork shifting force and the speed synchronization meet the expected threshold, controlling the fork of the target gear position to shift into gear. This gear shifting method enables the fork to control the magnitude of the shifting force in a trend of approaching displacement within a reasonable synchronous speed threshold, preventing abnormal noises caused by position overshoot in each stage of gear shifting.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy vehicles, and particularly to a gear shifting method for a gearbox, an electronic device, and an automobile based on a pneumatic switch valve group shifting control mechanism. Background Art

[0002] Pure electric heavy trucks have excellent characteristics, and their market share is increasing day by day. As a core driving component, the new energy gearbox is a powerful guarantee for its performance. There are many differences between new energy gearboxes and traditional gearboxes, and the differences in mechanical structures directly lead to different control strategies. With the increasingly wide application of new energy gearboxes, the shifting quality of the gearbox has also become a hard indicator for evaluating the performance of the drive system. In addition to basic reliability, the shifting of new energy gearboxes also requires smooth shifting and no abnormal noise.

[0003] In the prior art, the gear shifting of the gearbox is divided into five stages: unloading, gear disengaging, speed regulation, gear engaging, and torque recovery. However, in many practices, it is found that if the gear engaging stage is not properly handled, it is easy to cause problems such as shifting jerks, abnormal noises, gear teeth hitting, and even gear engaging failures. When the shifting mechanism is a pneumatic control mechanism and is a switch valve group, the accuracy of the shifting force control is affected by the gas flow, and the gas flow is affected by factors such as pipelines, valve switching frequencies, and pressures, resulting in certain uncertainties and fluctuations. When the shifting force is too large, the engaging sleeve is likely to collide with the end face of the gear at the engaging position or after the gear engaging is completed, generating gear teeth hitting (at the engaging position) and impact sounds. Moreover, during the interruption of the shifting power, the input speed of the rotating system will decay during the gear engaging stage due to the frictional force between system components, air resistance, the resistance of the motor coil, and the eddy current loss of the iron core. If the decay is too large, the synchronous speed will exceed the expected threshold, resulting in gear teeth hitting during gear engaging and even gear engaging failure. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a gear shifting method for a gearbox, an electronic device, and an automobile based on a pneumatic switch valve group shifting control mechanism to solve the problems mentioned in the background art.

[0005] The above object of the present invention is achieved through the following technical solutions:

[0006] A gear shifting method for a gearbox based on a pneumatic switch valve group shifting control mechanism includes the following steps:

[0007] Pre-divide the gear engaging stage according to the shifting dimension chain and calibrate the demarcation points of each stage;

[0008] Obtain the shift fork displacement and shift fork moving speed, design a two-parameter shift fork shifting force duty cycle control table, and calibrate the valve group enabling and duty cycle of each stage;

[0009] Calibrate the highest threshold value, and determine whether the current shifting fork movement speed is greater than the highest threshold value allowed in the current stage. If it is greater than the highest threshold value, then disable the valve group.

[0010] Determine the rotational speed difference threshold value according to the target gear position and the rotational speed of the output system, and judge whether the difference between the rotational speed of the input system and the target rotational speed is within the expected threshold value. If it is within the expected threshold value, that is, in the rotational speed synchronization state, then control the shifting fork of the target gear position to shift into gear.

[0011] In a preferred example of the present invention, it can be further configured that: when the rotational speed of the input system and the target rotational speed are not within the expected threshold value, design a compensation torque, and the parameters include the target gear position and the rotational speed rate of the input shaft. Perform torque compensation through the target gear position and the rotational speed rate of the input shaft to ensure that the difference between the rotational speed of the input system and the target rotational speed is within the expected threshold value and ensure rotational speed synchronization.

[0012] In a preferred example of the present invention, it can be further configured that: the gear shifting into gear stage is divided into four stages, which are respectively:

[0013] Starting stage: from the lowest point a of the neutral gear self-locking ball socket to the highest point b of the neutral gear self-locking ball socket;

[0014] Clearance stage: from point b of the neutral gear self-locking ball socket to the position where the internal teeth of the synchromesh sleeve and the end face teeth of the gear position gear are about to mesh;

[0015] Meshing stage: from the meshing point of the internal teeth of the synchromesh sleeve and the end face teeth of the gear position gear to the highest point c of the gear position self-locking ball socket;

[0016] Confirmation stage: from point c of the gear position self-locking ball socket to the lowest point d of the gear position self-locking ball socket.

[0017] In a preferred example of the present invention, it can be further configured that: according to the mechanical design and the movement characteristics of the shifting fork, calibrate the duty ratio of each stage, and the duty ratio is: the starting stage > the meshing stage > the clearance stage > the confirmation stage.

[0018] In a preferred example of the present invention, it can be further configured that: compensating the torque of the drive motor according to the target gear position and the rotational speed rate of the input shaft includes:

[0019] When the shifting fork moves in the starting stage and the clearance stage, compensate the torque of the drive motor.

[0020] In a preferred example of the present invention, it can be further configured that: before the gear shifting into gear stage is divided into stages according to the shifting dimension chain in advance, adjust the speed of the transmission.

[0021] An electronic device includes a memory and a processor. A computer program is stored in the memory. When the computer program is executed by the processor, the steps of a gear shifting method for a gearbox based on a pneumatic switch valve group shifting mechanism are implemented.

[0022] A vehicle is equipped with an electronic device.

[0023] In summary, the present invention includes at least one of the following beneficial technical effects:

[0024] 1. Refine the stroke in the gear engagement stage. By adjusting the duty cycle enabling and magnitude of the valve group through two parameters, namely the shift fork displacement and the shift fork movement rate, a closed-loop control is formed to control the advance switch and its magnitude, thereby realizing the control of the displacement speed and shifting force throughout the stroke.

[0025] 2. The present invention designs a two-parameter torque compensation. Compared with no torque compensation or single-parameter torque compensation, by analyzing actual data, the motor speed decay can be well controlled, and it can be ensured that during the gear engagement process, the radial torque on the meshing surface of the synchronizer sleeve is smaller. According to (where is the friction coefficient), the moving resistance f of the synchronizer sleeve is smaller, which is more conducive to the movement of the shift fork.

[0026] In summary, through the combined action of the above two measures in the gear engagement stage, the compensation torque can control the synchronous speed, and the two parameters of the shift fork displacement and movement rate can control the speed and force of the shift fork displacement. Only by combining the two can it be ensured that the shift fork engages in gear within a reasonable synchronous speed threshold with a displacement approximation trend, preventing abnormal noises or even gear teeth damage due to position overshoot in each stage. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is the gearbox logic control diagram for the gear engagement stage;

[0028] Figure 2 is the design diagram of the self-locking ball socket of the gearbox shift fork shaft;

[0029] Figure 3 is the schematic diagram of the refinement of the gear engagement stage. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] The present invention will be further described in detail below with reference to the accompanying drawings.

[0031] As Figures 1-3 shown, a gear shifting method for a gearbox based on a pneumatic switch valve group shifting mechanism disclosed in this technical solution includes the following steps:

[0032] Pre-divide the gear engagement stage according to the shift dimension chain and calibrate the demarcation points of each stage; it should be noted that when dividing the stages, the gearbox needs to be speed-regulated in advance to ensure that the initial data can be obtained.

[0033] Specifically, the gearbox with a pneumatic switch valve group shift control mechanism adopts a self-locking ball socket design for the shift fork shaft. The gear engagement stage is divided according to the theoretical shift dimension chain and the self-locking ball socket design of the shift fork shaft. The air intake volume and direction in each stage are controlled by the switch frequency of the control valve group, ultimately ensuring that the gear engagement force and direction in each stage are controllable.

[0034] Furthermore, the gear engagement stage is divided into four stages, namely:

[0035] Starting stage: from the lowest point a of the neutral self-locking ball socket to the highest point b of the neutral self-locking ball socket;

[0036] Clearance stage: from point b of the neutral self-locking ball socket to the position where the internal teeth of the synchromesh sleeve and the end face teeth of the gear will engage;

[0037] Engagement stage: from the engagement point of the internal teeth of the synchromesh sleeve and the end face teeth of the gear to the highest point c of the gear self-locking ball socket;

[0038] Confirmation stage: from point c of the gear self-locking ball socket to the lowest point d of the gear self-locking ball socket.

[0039] The demarcation point between each stage is a window value that can be calibrated to improve the applicability of the program. Since the demarcation point is convenient to calibrate, the gear engagement force and direction can be accurately controlled, providing a data basis for subsequent parameter compensation, that is, through accurate values, more precise compensation can be carried out.

[0040] Obtain the shift fork displacement and shift fork movement rate, design a two-parameter shift fork shift force duty cycle control table, and calibrate the valve group enabling and duty cycle in each stage;

[0041] The two parameters are the shift fork displacement and the shift fork movement rate. Referring to these values, the valve group enabling and duty cycle size can be calibrated in the corresponding stage.

[0042] Firstly, when the shift fork movement rate is greater than the current stage's allowable maximum threshold (a calibratable quantity), the valve group enabling is closed. After the rate returns to a reasonable range, the stage where the shift fork is located is judged according to the actual position of the shift fork, and then it is decided whether to open the valve group enabling;

[0043] Secondly, according to the mechanical design and the movement characteristics of the shift fork, the duty cycle size in each stage is calibrated.

[0044] By adjusting the enabling and size of the duty cycle through the two parameters of the shift fork displacement and the shift fork movement rate, a closed-loop control is formed, which can control the enabling and size of the advance switch, and further control the displacement speed and shift force of the entire stroke. The closed-loop control formed here allows the operator to make corresponding judgments based on the feedback information after the instruction is issued, and further operate on the feedback message.

[0045] Considering the characteristics of gas flow and the judgment of the fork advance, combined with actual vehicle experiments, the duty cycle should be: starting stage > meshing stage > clearance stage > confirmation stage. Combining the actual duty cycle here, a preliminary understanding of the numerical value can be obtained, which is convenient for subsequent corresponding operations.

[0046] Calibrate the highest threshold value, which can be set by yourself here. Determine whether the current fork movement speed is greater than the highest threshold value allowed in the current stage. If it is greater than the highest threshold value, then turn off the valve group enable; the highest threshold value calibrated here can control the current state of the vehicle and also pave the way for subsequent steps.

[0047] Determine the rotational speed difference threshold according to the target gear and the rotational speed of the output system. Judge whether the difference between the rotational speed of the input system and the target rotational speed is within the expected threshold value. If it is within the expected threshold value, that is, the rotational speed synchronization state, then control the fork of the target gear to shift into gear. This is the non-compensation interval.

[0048] The rotational speed of the input system and the target rotational speed are not within the expected threshold value:

[0049] Design a compensation torque table, the parameters include the target gear and the rotational speed rate of the input shaft. Perform torque compensation through the target gear and the rotational speed rate of the input shaft to ensure that the difference between the rotational speed of the input system and the target rotational speed is within the expected threshold value and ensure rotational speed synchronization.

[0050] According to the target gear and the rotational speed rate of the input shaft, it is necessary to compensate the drive motor. The compensation for the drive motor torque includes:

[0051] When the fork moves in the starting stage and the clearance stage, compensate the drive motor torque.

[0052] When the transmission is matched with different motors, due to different resistances of the motors and internal losses of the coils, the resistance is different; or for the same model of motor with different gears, due to different inertias and frictions of the rotating system, etc., the resistance is also different. That is, the vehicle driving force should be: F d = F mot + f + Jβ (F d is the vehicle driving force, F mot is the motor torque, f is the transmission system resistance (opposite to the driving direction), J is the moment of inertia of the current rotating system, and β is the angular acceleration of the rotating system).

[0053] Specifically, for the same model of vehicle and a certain fixed gear, when the fork moves in the starting stage of shifting into gear and the clearance stage of shifting into gear, the engaging sleeve and the end face teeth of the gear are in a non-engaged state, and the power of the drive system is interrupted.

[0054] Assume that the driving motor torque is 0 at this time, then the input speed of the rotating system will decay. Because according to: (where: f is the sum of the transmission system resistances; is the current moment of inertia of the rotating system; When f is large, remains unchanged, then increases, and its direction is opposite to the movement direction of the rotating system, so the system speed decay intensifies. Therefore, it can be known that when the system speed decay intensifies, the system needs to apply a driving force to neutralize f. Even when the driving force F = f, then: , then the rotating system should maintain a stable speed. Therefore, in summary, design a table for compensating torque F, and look up the table through two parameters ("target gear position" and "input system speed decay value") for torque compensation, and try to ensure that the difference between the speed of the input system and the target speed in this stage is within the expected threshold to ensure the speed synchronization state. The two-parameter torque compensation designed here can, through analyzing actual data, better control the motor speed decay compared with no torque compensation or single-parameter torque compensation, and can ensure that during the gear engagement process, the radial torque on the meshing surface of the synchronizer sleeve is smaller. According to ( is the friction coefficient), the moving resistance f of the synchronizer sleeve is smaller, which is more conducive to the movement of the shift fork.

[0055] The implementation principle of this embodiment is as follows: For the gear engagement method of the gearbox with a pneumatic switch valve group shift control mechanism, after the gearbox speed regulation is completed, the gear engagement stage is divided into four stages according to the theoretical shift dimension chain, including the start stage, the clearance stage, the meshing stage, and the confirmation stage, and the demarcation points of each stage are calibrated; obtain the shift fork displacement value and the shift fork movement rate, and according to the shift fork displacement and the shift fork movement rate, calibrate the valve group enabling and duty cycle size of each stage, and judge whether the shift fork shifting force meets the expected threshold; obtain the target gear position and the input shaft speed rate, and according to the target gear position and the input shaft speed rate, compensate the driving motor torque when the shift fork moves in the gear engagement start and gear engagement clearance stages, and judge whether the speed synchronization meets the expected threshold; if the shift fork shifting force and the speed synchronization meet the expected threshold, then control the shift fork of the target gear position to engage.

[0056] Based on the gear engagement method of the gearbox described in the above solution, this technical solution also provides an electronic device, including a memory and a processor. A computer program is stored in the memory. When the computer program is executed by the processor, the steps of the above gear engagement method of the gearbox are implemented, achieving the effect of controlling the displacement speed and shifting force of the entire stroke.

[0057] Based on a vehicle described in the above solution, this technical solution also provides a vehicle. This vehicle includes the above electronic device and is used to execute the steps of implementing the above gear engagement method of the gearbox, which will not be elaborated here.

[0058] The present invention refines the travel during the gear engagement stage. By adjusting the duty cycle enabling and magnitude of the valve group through two parameters, namely the shift fork displacement and the shift fork movement rate, a closed-loop control is formed to control the enabling and magnitude of the advance switch, thereby achieving the control of the displacement speed and shifting force throughout the travel. Torque compensation is performed by looking up a table based on two parameters, namely the target gear position and the input shaft rotational speed rate. Compared with no torque compensation or single-parameter torque compensation, by analyzing actual data, the motor speed decay can be well controlled, such that during the gear engagement process, the radial torque F on the meshing surface of the synchronizer sleeve r is smaller. According to f = μ * F r (where μ is the friction coefficient), the movement resistance f of the synchronizer sleeve is smaller, which is beneficial to the movement of the shift fork. The speed and force of the shift fork displacement are controlled through two parameters, namely the shift fork displacement and the shift fork movement rate. The synchronous rotational speed is controlled through compensated torque. The two are combined and act together during the gear engagement stage to ensure that the shift fork engages in gear with a displacement approximation trend within a reasonable synchronous rotational speed threshold, preventing abnormal noises and gear clashes due to position overshoot in each stage.

[0059] The embodiments of this specific implementation manner are all preferred embodiments of the present invention, and do not limit the protection scope of the present invention accordingly. Therefore, all equivalent changes made according to the structure, shape, and principle of the present invention shall be covered within the protection scope of the present invention.

Claims

1. A gearbox shifting method based on a pneumatic switch valve group shifting control mechanism, characterized in that: The steps include: Divide the gear shifting phase into stages according to the gear shifting dimension chain in advance, and calibrate the dividing point of each stage; Obtain the fork displacement and fork moving speed, design the fork shift force duty cycle control table with two parameters: fork displacement and fork moving speed, and calibrate the valve group enable and duty cycle at each stage; Calibrate the highest threshold value to determine whether the current fork movement rate is greater than the maximum threshold value allowed in the current stage. If it is greater than the maximum threshold value, the valve group is closed to enable; The speed difference threshold is determined according to the target gear and the output system speed, and it is judged whether the difference between the input system speed and the target speed is within the expected threshold. If it is within the expected threshold, that is, the speed is synchronized, the shift fork of the target gear is controlled to shift into gear; The gearbox based on the pneumatic switch valve group shift control mechanism adopts the self-locking ball and socket design of the fork shaft; The rotation speed of the input system and the target rotation speed are not within the expected threshold, and a compensation torque is designed, and the parameters include the target gear and the input shaft rotation speed rate. The torque compensation is performed through the target gear and the input shaft rotation speed rate to ensure that the difference between the rotation speed of the input system and the target rotation speed is within the expected threshold, thereby ensuring rotation speed synchronization; The gear-in phase is divided into four stages: Starting stage: from the lowest point a of the neutral self-locking ball socket to the highest point b of the neutral self-locking ball socket; Clearance stage: from the neutral self-locking ball socket point b to the position where the internal teeth of the coupling sleeve and the end face teeth of the gear gear will mesh; Meshing stage: from the meshing point between the internal teeth of the coupling sleeve and the end teeth of the gear gear to the highest point c of the gear self-locking ball socket; Confirmation stage: from point c of the gear self-locking ball socket to the lowest point d of the gear self-locking ball socket.

2. A gearbox shifting method based on a pneumatic switch valve group shifting mechanism according to claim 1, characterized in that: The duty cycle of each stage is calibrated according to the mechanical design and the movement characteristics of the shift fork, and the duty cycle is as follows: the starting stage> the meshing stage> the gap stage> the confirmation stage.

3. A gearbox shifting method based on a pneumatic switch valve group shifting mechanism according to claim 2, characterized in that: According to the target gear position and the input shaft speed rate, compensating the drive motor torque includes: When the shift fork moves in the starting phase and the gap phase, the driving motor torque is compensated.

4. A gearbox shifting method based on a pneumatic switch valve group shifting mechanism according to claim 3, characterized in that: Before the advance gear shifting phase is divided into stages according to the gear shifting size chain, the gearbox is speed regulated.

5. An electronic device comprising a memory and a processor, characterized in that: The memory stores a computer program, and when the computer program is executed by the processor, the steps of the transmission shifting method based on the pneumatic switch valve group shifting control mechanism as claimed in any one of claims 1 to 4 are implemented.

6. A car, characterized in that: The electronic device is provided with the electronic device according to claim 5.

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