Control mechanism for electric control gear shifting of hybrid tractor

Abstract

The invention relates to a control mechanism for electric control gear shifting of a hybrid tractor. The control mechanism comprises a control module, a gear shifting mechanism, an executing mechanism and a control panel. The control module comprises a gear shifting control program, the gear shifting mechanism comprises a meshing sleeve, a gear shifting gear and a transmission shaft, the gear shifting gear is rotationally connected to the transmission shaft, the meshing sleeve is slidably connected to the transmission shaft, and meshing structures are arranged between the meshing sleeve and the transmission shaft and between the meshing sleeve and the gear shifting gear and used for achieving synchronous transmission of the transmission shaft and the gear shifting gear. The executing mechanism is used for controlling the meshing sleeve to axially move on the transmission shaft; the control program is used for selecting a gear shifting gear according to a signal of the control panel, controlling the meshing sleeve to move through the executing mechanism to achieve gear shifting, if meshing is not successful, meshing is executed again after resetting, and if meshing is not completed within preset time, a gear engaging failure signal is sent, and the rotating speed of the speed change mechanism is adjusted till meshing is completed.

Description

Technical Field

[0001] The present invention is a control mechanism for electronically controlled gear shifting of a hybrid tractor. Background Art

[0002] In the field of modern agricultural machinery, the power of wheeled tractors has been continuously improved, significantly enhancing their working range and operating speed. To achieve the best match between the power performance and economy of tractors, tractors need to be able to automatically select appropriate gears according to engine operating conditions and load changes. Currently, foreign high-power tractors generally adopt electronically controlled automatic gear shifting technology. For example, the 8000 series of Deere & Company and the 900 series of Fendt. These models, with their advanced electronic control systems, achieve efficient and precise gear shifting, improving operation efficiency and driving comfort.

[0003] In contrast, most domestic-developed high-power wheeled tractors adopt the transmission forms of a main clutch plus a mechanical gear shifting gearbox or a wet main clutch plus a power shift gearbox. These gearboxes usually adopt a mechanical double-rod control method, which has the advantages of strong load-bearing capacity, multiple gears, and a wide speed ratio range, suitable for various operation requirements. However, in some complex working conditions, mechanical gear shifting operations are prone to mis-shifting, thus affecting the driving safety of tractors. In addition, if the driver cannot accurately grasp the gear shifting timing, it will affect the fuel economy and power performance of the tractor, resulting in reduced operation efficiency. At the same time, frequent manual gear shifting also increases the labor intensity of the driver and affects the comfort of long-term operation. Therefore, there is still much room for improvement in the existing mechanical gear shifting method in terms of precise gear shifting, driving convenience, and fuel economy. Summary of the Invention

[0004] The purpose of the present invention is to solve the above-mentioned deficiencies of the prior art and provide a control mechanism for electronically controlled gear shifting of a hybrid tractor.

[0005] A control mechanism for electronically controlled gear shifting of a hybrid tractor includes a control module, a gear shifting mechanism, an actuator, and a control panel. The control module includes a gear shifting control program. The gear shifting mechanism includes a sliding sleeve, a gear shifting gear, and a transmission shaft. The gear shifting gear is rotatably connected to the transmission shaft, and the sliding sleeve is slidably connected to the transmission shaft. An engaging structure is provided between the sliding sleeve and the transmission shaft and the gear shifting gear. The sliding sleeve is used to achieve synchronous transmission between the transmission shaft and the gear shifting gear. The actuator is used to control the axial movement of the sliding sleeve on the transmission shaft;

[0006] The control program is used to perform the following steps:

[0007] Step 1: Select the gear shifting gear to be engaged according to the signal transmitted from the control panel;

[0008] Step 2: The actuator controls the movement of the sliding sleeve to synchronize the transmission shaft and the corresponding shift gear;

[0009] Step 3: If the engagement is not successful, the actuator controls the sliding sleeve to reset and re-perform the engagement action. Repeat the above process until the sliding sleeve engages with the shift gear;

[0010] Step 4: If the engagement is not completed within the preset time, a gear shifting failure signal is sent, the speed of the transmission mechanism is adjusted, and Steps 3 and 4 are repeated until the sliding sleeve engages with the shift gear.

[0011] Further, the sliding sleeve engages with the transmission shaft and the shift gear through a spline structure.

[0012] Further, the actuator includes a motor, a rocker arm, a shift fork shaft, shift fork feet, and a shift fork sleeve. The motor is connected to one end of the rocker arm, the other end of the rocker arm is connected to the shift fork sleeve, the shift fork sleeve is slidably sleeved on the shift fork shaft, and shift fork feet connected to the sliding sleeve are provided on the outer side of the shift fork sleeve.

[0013] Further, a displacement sensor is provided in the actuator.

[0014] Further, a bearing is provided between the shift gear and the transmission shaft.

[0015] Further, the control module includes a controller, and the controller includes:

[0016] Vehicle Control Unit (VCU): Receives the operation signal and forwards it to the TCU;

[0017] Transmission Control Unit (TCU): According to the command signal from the VCU and in combination with the feedback of the position sensor, controls the forward and reverse rotation of the motor, thereby realizing gear shifting;

[0018] Rotation Speed Control Unit (RCU): When the gear shifting is not completed, the RCU receives the signal sent by the TCU and adjusts the speed of the transmission mechanism.

[0019] Further, the control module further includes a display screen, and the display screen is used to display the gear shifting state information.

[0020] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0021] The gear shifting control program of the present invention is based on the collaborative work of the VCU (Vehicle Control Unit), TCU (Transmission Control Unit), and RCU (Rotation Speed Control Unit), realizing full-automatic control of gear shifting. The driver only needs to press the gear shifting button, and the system can independently perform the gear shifting operation without manual intervention, greatly improving the convenience of gear shifting and the operation efficiency.

[0022] The shift control program can monitor the shift state in real time and, based on the feedback from the motor position sensor, precisely control the forward / backward rotation of the shift motor to ensure the synchronous movement of the shift lever, shift fork, and engagement sleeve. If a shift fails, the system will automatically return to zero and attempt to shift again, avoiding shift jamming problems caused by mismatched engagement.

[0023] After a shift failure, the shift control program will send a signal to the RCU (Rotation Control Unit) to adjust the rotation speed of the transmission mechanism, rotate the gear set to a new angle, and optimize the engagement conditions. Subsequently, the system will automatically re-execute the shift operation, and this process can continue until a successful shift is achieved, thus effectively improving the shift success rate.

[0024] Before ignition and after engine shutdown, the program will automatically perform neutral detection. If the gear is not in neutral, the system will immediately perform a neutral reset operation to ensure that the tractor is in a safe state when starting or shutting down, prevent accidental vehicle movement caused by misoperation, and improve safety.

[0025] The shift control program adopts a CAN bus architecture. The TCU can obtain shift instructions in real time and interact with modules such as the shift motor, position sensor, and display screen to ensure precise and efficient shift operations. In addition, the shift state can be displayed on the display screen in real time, allowing the driver to intuitively monitor the current gear state and improve the visualization of the operation.

[0026] The shift control program can dynamically adjust the shift execution strategy by combining parameters such as the current gear, target gear, gear set rotation speed, and shift motor position. For example, under low-speed or high-load operating conditions, the program can optimize the shift timing, avoid shift shocks, improve shift smoothness, and enhance the driving experience and power transmission efficiency of the entire vehicle.

[0027] Compared with traditional mechanical shifting, the shift control program reduces the impact and friction between gears through precise control of the engagement process, reduces the mechanical losses of the shift mechanism, and extends the service life of the equipment. At the same time, the system can monitor the shift motor and engagement state in real time, give early warnings of potential faults, and reduce maintenance costs.

[0028] The shift control program can be adapted to different tractor transmission structures and support multiple shift modes (manual shift, automatic shift, etc.), and can be adjusted according to different operation requirements, improving the flexibility and adaptability of the system. Description of the Drawings

[0029] Figure 1 is the flowchart of the shift control program. Detailed Implementation Manner

[0030] To deepen the understanding of the present invention, the present invention will be further described in detail below in conjunction with embodiments and drawings. The embodiments are only used to explain the present invention and do not constitute a limitation on the protection scope of the present invention.

[0031] A control mechanism for an electronically controlled shift of a hybrid tractor includes a control module, a shift mechanism, an actuator, and a control panel. The control module includes a shift control program. The shift mechanism includes a dog clutch, shift gears, and a transmission shaft. The shift gears are rotatably connected to the transmission shaft, the dog clutch is slidably connected to the transmission shaft, and an engagement structure is provided between the dog clutch and the transmission shaft and the shift gears. The dog clutch is used to achieve synchronous transmission between the transmission shaft and the shift gears. The actuator is used to control the axial movement of the dog clutch on the transmission shaft.

[0032] In this embodiment, the control module receives signals from the control panel and executes the shift control program. First, the system determines the target shift gear according to the received shift command. Subsequently, the actuator drives the dog clutch to axially move along the transmission shaft, so that the dog clutch is engaged with the target shift gear, thereby realizing the synchronous movement of the transmission shaft and the shift gears. If the engagement fails, the actuator will automatically control the dog clutch to reset and repeat the engagement action until the engagement is successful. If the engagement is still not successful within the preset time, the control module sends a signal indicating that the gear shifting fails, and at the same time adjusts the rotational speed of the speed change mechanism to optimize the gear engagement conditions and tries to engage again until the engagement is successful.

[0033] This embodiment realizes the automatic shift of the tractor through the electronically controlled shift method, avoiding the problems of possible gear impact and unsmooth engagement in the traditional mechanical shift process, and improving the smoothness and reliability of the shift. In addition, the control mechanism can automatically adjust the rotational speed of the speed change mechanism when the shift fails, improve the shift success rate, reduce human intervention, and improve the driving comfort and operation efficiency.

[0034] In other embodiments, the shift control program can adopt different algorithms to optimize the shift logic. For example, an adaptive shift strategy is introduced to automatically adjust the shift timing according to the engine load and the working environment. In addition, the actuator can adopt a hydraulic drive structure to replace the motor drive scheme to adapt to the shift system with greater torque requirements.

[0035] In a possible embodiment, the dog clutch is engaged with the transmission shaft and the shift gears through a spline structure.

[0036] The spline structure enables the dog clutch to slide reliably along the transmission shaft and form a stable torque transmission path at the shift gears by improving the engagement accuracy and stability. Through the precisely machined spline design, the possible gear slip and vibration during the shift process can be effectively reduced, and the stability of the power transmission can be improved.

[0037] The spline structure is adopted to make the meshing more reliable, reduce the wear between gears, improve the smoothness of gear shifting, and extend the service life of the gear shifting mechanism. In addition, this structure can maintain good transmission efficiency under high load conditions and improve the dynamic performance of the whole vehicle.

[0038] In other embodiments, the spline structure can adopt various shapes, such as straight splines, involute splines or circular arc splines, to meet different gear shifting load requirements. At the same time, a wedge connection method or other high-precision positioning structures can also be used to replace the spline connection to improve the rigidity and service life of the system.

[0039] In a possible embodiment, the actuator includes a motor, a rocker arm, a shift fork shaft, shift fork feet, and a shift fork sleeve. The motor is connected to one end of the rocker arm, the other end of the rocker arm is connected to the shift fork sleeve, the shift fork sleeve is slidably sleeved on the shift fork shaft, and the outer side of the shift fork sleeve is provided with shift fork feet connected to the engaging sleeve.

[0040] When a gear shifting command is issued, the control module sends a signal to the actuator. The motor drives the rocker arm to move, the rocker arm drives the shift fork sleeve to slide along the shift fork shaft, and the shift fork feet push the engaging sleeve to move axially along the transmission shaft, finally realizing the meshing of the target gear. If the meshing fails, the motor will control the rocker arm to return to its original position and execute the gear shifting action again.

[0041] This actuator has a compact structure and a clear transmission path. By driving with a motor and amplifying the acting force through a lever mechanism, it can achieve fast and stable gear shifting. Compared with traditional mechanical gear shifting, this mechanism can reduce human operation errors and improve the automation degree and execution accuracy of gear shifting.

[0042] In other embodiments, the rocker arm can adopt different lengths or different shapes to optimize the gear shifting torque transmission efficiency. At the same time, the shift fork structure can be replaced with a linear drive mechanism to improve the gear shifting accuracy. In addition, a hydraulic actuator can also be used to meet the gear shifting requirements of higher loads.

[0043] In a possible embodiment, a displacement sensor is provided inside the actuator.

[0044] Working principle

[0045] The displacement sensor is used to detect the position of the shift fork shaft or the shift fork sleeve in real time and feed the data back to the control module. The control module judges the meshing state according to the feedback information and adjusts the motor control strategy when not fully meshed to optimize the gear shifting execution process.

[0046] By introducing a displacement sensor, the gear shifting execution situation can be monitored in real time, the gear shifting accuracy and reliability can be improved, the jamming of the engaging sleeve or gear shifting failure can be prevented, and the intelligent level of the whole vehicle can be further enhanced.

[0047] In other embodiments, displacement sensors can adopt different detection technologies, such as optoelectronic sensors, Hall sensors, or LVDT sensors, to improve detection accuracy and adaptability. At the same time, force sensors can also be used to detect the meshing torque to assist in shift control.

[0048] In a possible embodiment, a bearing is provided between the shift gear and the drive shaft.

[0049] The bearing is used to reduce the rotational friction of the shift gear on the drive shaft, ensuring that the shift gear can rotate freely under low resistance conditions to achieve smoother power transmission.

[0050] Using a bearing reduces the friction between the shift gear and the drive shaft, improves the smoothness of shifting, reduces wear, and improves the reliability and durability of the transmission mechanism.

[0051] In other embodiments, ball bearings, needle bearings, or sliding bearings can be selected to meet the shifting requirements under different load conditions.

[0052] In a possible embodiment, the control module includes a controller, and the controller includes: a vehicle control unit (VCU), a transmission control unit (TCU), and a rotational speed control unit (RCU).

[0053] The VCU receives the operation signal and forwards it to the TCU. The TCU controls the shift actuator according to the instructions of the VCU, and at the same time optimizes the shift operation in combination with the feedback of the displacement sensor. When the gear shifting fails, the RCU receives the TCU signal and adjusts the rotational speed of the transmission mechanism to optimize the meshing conditions.

[0054] This control system improves the intelligence and automation level of shifting, reduces human intervention, and improves the shifting success rate and driving comfort.

[0055] In a possible embodiment, the control module further includes a display screen for displaying shift status information.

[0056] The display screen provides intuitive shift status feedback, improves the user's perception of the vehicle status, and facilitates maintenance and fault diagnosis.

[0057] Description of the working process: The operator sends a shift signal through the gear mode selection button on the control panel, and this signal is first transmitted to the vehicle control unit (VCU). The VCU combines the current working conditions and sends the corresponding shift instruction to the transmission control unit (TCU). After receiving the instruction, the TCU controls the forward / backward rotation of the shift motor through the H-bridge circuit in combination with the feedback information of the position sensor in the shift motor.

[0058] After the shift motor rotates, it drives the shift lever to adjust its position. At the same time, the shift lever drives the shift fork through the shift fork shaft, and finally pushes the engaging sleeve to move along the transmission shaft, so that it meshes with the 1 / 2 gear set of the target gear position, completing the gear shift.

[0059] Before ignition or after engine shutdown, the VCU automatically sends a neutral gear command to the TCU. If the current gear is not in the neutral position, the TCU will control the shift mechanism according to the command to automatically return the gear to the neutral position. At this time, the gear information will be displayed on the display screen in real time to ensure that the driver can intuitively obtain the current shift state.

[0060] When the tractor needs to shift gears during operation, the driver presses the shift button, and the shift command is immediately transmitted to the VCU. The VCU combines the current working conditions and sends a shift command to the TCU again. After receiving the signal, the TCU controls the H-bridge circuit to output a signal by reading the feedback information of the shift motor position sensor, driving the shift motor to rotate forward / backward.

[0061] After the motor rotates, the shift lever moves to the target position. The adjustment of this position depends on the target gear pressed and the current gear. The real-time position information of the shift lever will be displayed on the diagnostic page of the display screen to facilitate the operator to monitor the shift execution status.

[0062] During the gear shift process, the motor drives the shift lever to move, and the shift lever further drives the shift fork through the shift fork shaft, so that the shift fork pushes the engaging sleeve to mesh with the target gear set. Since the gear set is always rotating after the engine starts, once the engaging sleeve is successfully meshed, power transmission can be achieved and the gear shifting is completed.

[0063] The success of gear shifting is closely related to the rotational speed of the gear set at idle speed. To ensure smooth gear shifting, it is necessary to adjust to a suitable speed range so that the shift lever can smoothly enter the target position when pushing the engaging sleeve. The driver can initially judge the gear shifting situation through the shift lever position information on the display screen, but whether the gear shifting is successful ultimately depends on the gear information on the home page of the display screen.

[0064] If the gear shifting fails, the TCU will control the shift lever of the shift motor to automatically return to the zero position and perform the reciprocating movement + return to zero action within a limited time to attempt to shift gears multiple times. If it still fails within the set time, the TCU will send a gear shifting failure signal to the VCU.

[0065] When the VCU receives the gear shifting failure signal, it will further transmit the signal to the rotational speed control unit (RCU). After receiving the signal, the RCU adjusts the rotational speed of the transmission mechanism to rotate the gear set to a new angle to optimize the meshing conditions. After the adjustment is completed, the VCU will send a shift command to the TCU again, and the TCU will try to control the motor to rotate and drive the shift mechanism again. This process will continue until the gear shifting is successful.

[0066] The entire shift control system adopts a CAN bus structure. Compared with the traditional independent signal wire connection method, the number of wiring is significantly reduced, improving the reliability of the system.

[0067] In addition, devices such as the controller, shift mechanism, and display screen all transmit data through the bus, which not only enhances the data interaction ability but also makes the collaborative work among components more orderly, ensuring the intelligence and automation of shift operations and improving the overall shift efficiency and driving experience.

[0068] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A control mechanism for electronically controlled gear shifting of a hybrid tractor, characterized in that, It includes a control module, a shifting mechanism, an actuator, and a control panel. The control module includes a shifting control program. The shifting mechanism includes a dog clutch, shifting gears, and a transmission shaft. The shifting gears are rotatably connected to the transmission shaft, the dog clutch is slidably connected to the transmission shaft, and an engagement structure is provided between the dog clutch and the transmission shaft and the shifting gears. The dog clutch is used to achieve synchronous transmission between the transmission shaft and the shifting gears. The actuator is used to control the axial movement of the dog clutch on the transmission shaft; The control program is used to perform the following steps: Step 1: Select the shifting gear to be engaged according to the signal transmitted from the control panel; Step 2: Control the movement of the dog clutch through the actuator to make the transmission shaft and the corresponding shifting gear move synchronously; Step 3: If the engagement is not successful, the actuator controls the dog clutch to reset and re-perform the engagement action, repeating the above process until the dog clutch is engaged with the shifting gear; Step 4: If the engagement is not completed within the preset time, a gear shifting failure signal is sent, the speed of the speed change mechanism is adjusted, and Steps 3 and 4 are repeated until the dog clutch is engaged with the shifting gear.

2. The control mechanism for the electronic shift of a hybrid tractor according to claim 1, characterized in that, The dog clutch is engaged with the transmission shaft and the shifting gears through a spline structure.

3. The control mechanism for the electronic shift of a hybrid tractor according to claim 1, characterized in that, The actuator includes a motor, a rocker arm, a shift fork shaft, shift fork feet, and a shift fork sleeve. The motor is connected to one end of the rocker arm, the other end of the rocker arm is connected to the shift fork sleeve, the shift fork sleeve is slidably sleeved on the shift fork shaft, and shift fork feet connected to the dog clutch are provided on the outer side of the shift fork sleeve.

4. The control mechanism for the electric shift of a hybrid tractor according to claim 3, characterized in that, A displacement sensor is provided inside the actuator.

5. The control mechanism for electronic shift of a hybrid tractor according to claim 1, characterized in that, A bearing is provided between the shifting gear and the transmission shaft.

6. The control mechanism for the electro-hydraulic shift of a hybrid tractor according to claim 4, characterized in that The control module includes a controller, and the controller includes: Vehicle Control Unit (VCU): Receives operation signals and forwards them to the TCU; Transmission Control Unit (TCU): According to the command signal from the VCU and in combination with the feedback of the position sensor, controls the forward and reverse rotation of the motor, thereby achieving gear shifting; Rotation Speed Control Unit (RCU): When the gear shifting is not completed, the RCU receives the signal sent by the TCU and adjusts the speed of the speed change mechanism.

7. The control mechanism for electronically controlled gear shifting of a hybrid tractor according to claim 1, characterized in that, The control module further includes a display screen, and the display screen is used to display the shifting state information.

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