Gearbox special for hybrid power, control method and vehicle

Abstract

The invention provides a hybrid power special gearbox, a control method and a vehicle. The hybrid power special gearbox comprises an engine, a P1 motor, a P3 motor, a synchronizer and a gearbox input shaft. The output end of the engine is rigidly connected with the input shaft of the gearbox; a rotor of the P1 motor is coaxially connected with an input shaft of the gearbox; the synchronizer is used for selectively transmitting power of the engine and the P1 motor to the output end. By optimizing and canceling the clutch and the control logic, the total mass of the power system is reduced, the friction loss energy of the clutch is eliminated, the manufacturing cost of the power system is reduced, and the scheme can effectively reduce the manufacturing cost and improve the transmission efficiency.

Description

Technical Field

[0001] This invention relates to the field of progressive die machining technology, and in particular to a hybrid power transmission, control method, and vehicle. Background Technology

[0002] With the increasing number of hybrid vehicles, the dedicated hybrid transmission, a core component of hybrid vehicles, has also experienced rapid development and technological iteration. Currently, the technical approaches, control logic, and transmission efficiency of dedicated hybrid transmissions are diverse. Common transmission structures are referenced... Figure 3 As shown, some of these transmissions have high manufacturing costs and low transmission efficiency due to unreasonable control logic and structure, which leads to increased vehicle energy consumption.

[0003] Existing hybrid transmission control logic reference Figure 4 As shown (marked at 15 in the diagram is the clutch), when the vehicle needs the engine to engage in hybrid mode, the vehicle controller (HCU) sends a start command to the engine controller (ECU). After the ECU executes the command, it feeds back the result to the vehicle controller (HCU). At this time, after receiving the feedback from the engine controller (ECU), the HCU sends a command (including engine speed / torque information) to the transmission controller (TCU) to receive the engine's power output. After receiving the command, the transmission controller (TCU) controls the clutch to engage slowly, ultimately completing the engine engagement and power transmission.

[0004] The clutch engagement process involves the friction of the clutch friction plates driving the transmission input shaft to rotate and slowly reaching a relative speed of rest (i.e., the engine speed equals the transmission input shaft speed). At this point, the clutch is fully engaged, completing the transmission of speed / torque. The mechanical energy lost during the friction process reduces the transmission efficiency. Summary of the Invention

[0005] The purpose of this invention is to provide a dedicated hybrid power transmission, control method, and vehicle to solve the aforementioned technical problems.

[0006] The technical solution adopted by this invention to solve its technical problem is: A hybrid power transmission includes an engine, a P1 motor, a P3 motor, a synchronizer, and a transmission input shaft; the output end of the engine is rigidly connected to the transmission input shaft; the rotor of the P1 motor is coaxially connected to the transmission input shaft; the synchronizer is used to selectively transmit power from the engine and the P1 motor to the output end.

[0007] Furthermore, the P1 motor is a permanent magnet synchronous motor, which is arranged between the engine and the gearbox gear mechanism, and has the functions of starting the generator and torque assist.

[0008] Furthermore, the P3 motor is connected to the output end of the gearbox and is used to drive the vehicle independently or to output power in parallel with the engine.

[0009] The present invention also discloses a control method for the above-mentioned gearbox, comprising the following steps: When engine intervention is required, the vehicle control unit (HCU) simultaneously sends start-up preparation commands to both the engine control unit (ECU) and the transmission control unit (TCU). The TCU controls the P1 motor to drive the engine to the first target speed; The ECU controls engine ignition when the engine meets the ignition conditions; After the engine starts, the HCU calculates the second target speed based on the vehicle status and instructs the ECU to control the engine to adjust to the second target speed; When the engine speed is synchronized with the driven gear speed of the target gear, the TCU control synchronizer engages to complete the engine power intervention.

[0010] Furthermore, the start-up preparation command includes a first target speed and an initial torque, wherein the initial torque is 0 Nm.

[0011] Furthermore, in the step of the P1 motor driving the engine to the first target speed, the first target speed is a predetermined value within the range of 500-1500 rpm.

[0012] Furthermore, the conditions for determining the need for engine intervention include at least one of the following: vehicle speed exceeding a set threshold, power battery charge falling below a set threshold, or the driver requesting torque exceeding the maximum output torque in pure electric mode.

[0013] Furthermore, in the step of controlling the synchronizer engagement, the engagement condition is that the difference between the engine speed and the target gear driven gear speed is less than or equal to 150 rpm.

[0014] Furthermore, the HCU, ECU, and TCU communicate via a CAN bus to exchange speed, torque, and status flag information in real time.

[0015] The present invention also discloses a hybrid vehicle comprising the hybrid-specific transmission as described above, and configured to perform the control method described above. The beneficial effects of this invention are as follows: By optimizing and eliminating the clutch and control logic, this invention reduces the total mass of the power system, eliminates energy loss due to clutch friction, and lowers the manufacturing cost of the power system. This solution can effectively reduce manufacturing costs and improve transmission efficiency.

[0016] The present invention will now be described in more detail with reference to the accompanying drawings and embodiments. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the gearbox structure in this invention.

[0018] Figure 2 This is a flowchart of the control method in this invention.

[0019] Figure 3 This is a schematic diagram of the structure of a traditional gearbox; Figure 4 This is a flowchart of the control method corresponding to a traditional gearbox. Detailed Implementation

[0020] The core innovation of this invention's dedicated hybrid transmission (DHT) lies in its highly integrated and structurally simplified design. Please refer to the appendix. Figure 1 The transmission assembly mainly includes the following core components and their connections: Engine 1: Serves as the primary power source for the vehicle during high-speed, high-load, or low battery operation. Its output shaft is directly connected to the transmission input shaft via a rigid connector (such as a splined hub or flange), forming a slip-free, rigid power transmission path. This design fundamentally eliminates the need for traditional dry or wet multi-plate clutch assemblies.

[0021] P1 Motor 9: In this embodiment, P1 motor is a permanent magnet synchronous motor, whose rotor is arranged coaxially with the engine crankshaft and the gearbox input shaft. P1 motor has dual functions: first, as a high-power starter generator, it can quickly pull the engine to the target speed when it needs to be engaged; second, when the vehicle is braking or coasting, it can perform high-efficiency energy recovery as a generator.

[0022] P3 Motor 5: In this embodiment, the P3 motor is also a permanent magnet synchronous motor, and its rotor is connected to the output shaft 4 of the gearbox or the differential through a set of reduction gears. The main functions of the P3 motor are: in pure electric drive mode, it serves as the sole power source to drive the vehicle; in scenarios requiring high power, such as rapid acceleration or hill climbing, it outputs power in parallel with the engine to provide assistance.

[0023] Synchronizer 6: This component is key to achieving clutchless power engagement in this invention. Located inside the gearbox, it rigidly engages the drive gear 8, which has been driven to synchronized speed by the P1 motor and engine, with the driven gear 7 fixed to the output shaft. Its function is similar to the shift synchronizer in a traditional manual gearbox, but here it controls the connection and disconnection of engine power with the drive wheels 1.

[0024] Controller system: This is a distributed network control system, including: Vehicle Controller Unit 14 (HCU): As the "brain" of the vehicle, it is responsible for vehicle energy management, interpretation of driving intentions (analysis of throttle and brake signals), and overall coordination of the actions of the ECU and TCU.

[0025] Engine Controller 12 (ECU): Responsible for the control of the engine itself, including fuel injection, ignition, valve timing, etc., and accurately executes the speed and torque commands issued by the HCU.

[0026] Gearbox Controller 13 (TCU): Responsible for controlling the torque / speed of motor P1, as well as the engagement and disengagement of the synchronizer. The TCU integrates complex logic algorithms for real-time calculation of the target speed and determination of engagement conditions.

[0027] The aforementioned components are tightly coupled through mechanical connections and a high-speed CAN (Controller Area Network) bus, enabling efficient coordination of information and energy.

[0028] The following is in conjunction with the appendix Figure 2 This paper provides a step-by-step, in-depth analysis of a typical engine intervention scenario (e.g., a vehicle traveling in pure electric mode on a highway, with the driver pressing the accelerator to overtake). Step S1 (Intervention Condition Judgment): The vehicle is being driven smoothly by the P3 motor alone. At this moment, the driver suddenly presses the accelerator pedal, opening it to more than 70%. The HCU monitors this strong power demand signal in real time, and combined with the current vehicle speed (assuming 75km / h) and battery SOC (assuming 25%) information, based on the preset MAP map or strategy algorithm, it instantly determines that the P3 motor alone cannot meet the current power demand, and the engine must be activated to intervene in the hybrid drive mode.

[0029] Step S2 (Sending Coordinated Start-up Command): Instead of using the traditional serial command method, the HCU simultaneously sends an "engine ready to intervene" command packet containing target parameters to both the ECU and TCU via the CAN bus. This command packet includes at least: the initial target speed N_target (e.g., 700 rpm) and the initial torque T_target (0 Nm). This "broadcast" command significantly reduces the system response time.

[0030] Step S3 (Engine pre-synchronization and start-up): This is a parallel execution process.

[0031] On the TCU side: Within milliseconds of receiving the command, the TCU immediately controls the P1 motor to operate in speed control mode, outputting a smoothly increasing torque, which drives the stationary engine crankshaft to start rotating through the rigidly connected input shaft. Due to the absence of clutch slippage, the engine speed can quickly and accurately follow the P1 motor speed up to 700 rpm.

[0032] On the ECU side: The ECU is simultaneously activated, engaging the fuel pump, building up fuel rail pressure, and putting the ignition coils and injectors into standby mode. When the ECU detects via the crankshaft position sensor that the engine speed has reached the ignition point (e.g., above 500 rpm) and stabilizes around 700 rpm, it immediately controls the spark plugs to ignite and the injectors to inject fuel. Because the engine has already been brought to a certain speed, the ignition and start-up process is very rapid, smooth, and almost vibration-free.

[0033] Step S4 (Drivetrain Speed ​​Synchronization): At this point, although the engine has started, its power has not yet been transmitted to the wheels. The HCU calculates the output shaft speed matching the current vehicle speed (75 km / h) and the currently engaged gear ratio (e.g., overdrive, with a ratio of 0.8) in real time, and then calculates the theoretical speed N_driven of the driven gear. The HCU then sends new commands to the ECU and TCU, requesting that the engine speed (and the connected drive gear) be adjusted to synchronize with N_driven.

[0034] Step S5 (Precise Target Speed ​​Tracking): Based on the precise gear ratio information, the TCU calculates the precise target engine speed N_engine_final and sends it to the ECU via the CAN bus. The ECU takes over the control of the engine speed, adjusting the throttle opening and ignition advance angle to ensure the engine speed quickly and smoothly tracks to N_engine_final. During this stage, the P1 motor can switch to torque control mode to assist in adjustment or maintain idling. When the speed difference enters a very small tolerance range (e.g., ±10 rpm), the ECU and TCU send a "Speed ​​Synchronization Ready" signal to the HCU.

[0035] Steps S6 and S7 (Power Engagement): After confirming that all prerequisites are met, the HCU issues the final command to the TCU to "engage the synchronizer." The TCU controls the shift actuator to push the synchronizer sleeve onto the driven gear of the target gear. Since the speeds of the driving and driven gears are highly synchronized, the synchronizer only needs to overcome minimal inertia to complete a shock-free engagement. With a "click," the engine power is seamlessly integrated into the drive system, providing a powerful combined drive force with the P3 motor for overtaking, and the vehicle enters hybrid mode.

[0036] Finally, this embodiment also discloses a hybrid vehicle, which is equipped with the aforementioned transmission and configured with the aforementioned control method.

[0037] This embodiment achieves a significant improvement in overall performance through the aforementioned "structural subtraction" and "control addition": Dual optimization of manufacturing cost and weight: The clutch assembly, hydraulic control system (such as valve box, oil pump, and oil circuit), or electronic clutch actuator are directly eliminated, reducing not only the Bill of Materials (BOM) cost but also saving related design, assembly, and testing costs. Simultaneously, the removal of this hardware directly results in a 3-5 kg ​​weight reduction in the assembly, continuously contributing to vehicle lightweighting and energy consumption reduction. A significant leap in transmission efficiency: The slippage work loss present in traditional clutches during engagement is completely eliminated, a loss particularly significant in urban driving conditions with frequent start-stop cycles. Real-world testing shows that during engine intervention, this solution reduces energy loss by approximately 85%-95% compared to traditional clutch solutions, resulting in a 3%-5% improvement in the overall transmission efficiency of the powertrain, directly translating into lower fuel consumption and longer driving range. A qualitative leap in power responsiveness and smoothness: Traditional clutch engagement processes typically require hundreds of milliseconds or even longer and exhibit non-linear torque build-up. This solution, through the active drive of the P1 motor and the rigid combination of the synchronizer, shortens the total time for engine power engagement by approximately 0.5-1.0 seconds, achieving "on-demand" power response. More importantly, by avoiding the torque jump from slippage to lock-up of the friction plates, the entire engagement process is extremely smooth, with almost no jerking, significantly improving the driving experience. NVH (Noise, Vibration, and Harshness) performance improvement: Eliminating the clutch means eliminating a potential source of vibration and noise. Engine starting occurs after being driven to a certain speed, avoiding significant vibrations during low-speed starts. The entire system operates more quietly and smoothly. Increased reliability and reduced maintenance costs: The clutch is a vulnerable component in traditional transmission systems, posing risks of wear and overheating. Eliminating the clutch reduces potential failure points, improves the durability and reliability of the powertrain, and also reduces potential maintenance costs for users in the future.

[0038] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in this invention are only used to explain the relative positional relationship and movement of the components in a specific posture shown in the accompanying drawings. If the specific posture changes, the directional indication will also change accordingly.

[0039] The present invention has been described above with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any improvements made using the inventive concept and technical solution of the present invention, or direct application to other situations without modification, fall within the protection scope of the present invention.

Claims

1. A hybrid-dedicated transmission characterized by comprising: It includes an engine, a P1 motor, a P3 motor, a synchronizer, and a gearbox input shaft; the output end of the engine is rigidly connected to the gearbox input shaft; the rotor of the P1 motor is coaxially connected to the gearbox input shaft; the synchronizer is used to selectively transmit power from the engine and the P1 motor to the output end.

2. The hybrid power transmission according to claim 1, characterized in that, The P1 motor is a permanent magnet synchronous motor, which is located between the engine and the gearbox gear mechanism, and has the functions of starting the generator and torque assist.

3. A hybrid power transmission according to claim 2, characterized in that, The P3 motor is connected to the output end of the gearbox and is used to drive the vehicle independently or to output power in parallel with the engine.

4. A control method for a hybrid power transmission as described in any one of claims 1-3, characterized in that, Includes the following steps: When engine intervention is required, the vehicle control unit (HCU) simultaneously sends start-up preparation commands to both the engine control unit (ECU) and the transmission control unit (TCU). The TCU controls the P1 motor to drive the engine to the first target speed; The ECU controls engine ignition when the engine meets the ignition conditions; After the engine starts, the HCU calculates the second target speed based on the vehicle status and instructs the ECU to control the engine to adjust to the second target speed; When the engine speed is synchronized with the driven gear speed of the target gear, the TCU control synchronizer engages to complete the engine power intervention.

5. The control method according to claim 4, characterized in that, The start-up preparation command includes a first target speed and an initial torque, wherein the initial torque is 0 Nm.

6. The control method according to claim 4, characterized in that, In the step of the P1 motor driving the engine to the first target speed, the first target speed is a predetermined value within the range of 500-1500 rpm.

7. The control method according to claim 4, characterized in that, The conditions for determining the need for engine intervention include at least one of the following: vehicle speed exceeding a set threshold, power battery charge falling below a set threshold, or driver requesting torque exceeding the maximum output torque in pure electric mode.

8. The control method according to claim 4, characterized in that, In the process of controlling the synchronizer to engage, the engagement condition is that the difference between the engine speed and the target gear driven speed is less than or equal to 150 rpm.

9. The control method according to claim 4, characterized in that, The HCU, ECU, and TCU communicate via a CAN bus to exchange speed, torque, and status information in real time.

10. A hybrid vehicle, characterized in that, It includes a hybrid-specific transmission as described in any one of claims 1-3, and is configured to perform the control method as described in any one of claims 4-9.

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