Hybrid power assembly for heavy commercial vehicle and control method of hybrid power assembly

Abstract

The invention discloses a hybrid power assembly for a heavy commercial vehicle and a control method of the hybrid power assembly. The hybrid power assembly comprises an engine, a clutch, a first motor, a second motor, a planet row system, a gearbox system, a shell and a sliding sleeve locking mechanism. Wherein the shell is fixedly arranged, the planet row system, the sliding sleeve locking mechanism and the gearbox system are installed in the shell, and the sliding sleeve locking mechanism is fixedly connected with the inner wall of the shell; the engine is connected with the planet row system and the gearbox system through the clutch and the output shaft, and the row sun gear is connected with the inner wall of the shell in an on-off mode through the sliding sleeve locking mechanism. The control method comprises a pure electric mode, a hybrid mode, a braking energy recovery mode, an engine direct drive mode and a high-voltage fault limping mode. According to the invention, the whole vehicle can still be driven when the whole vehicle has a high-voltage fault, and the clutch and the sliding sleeve locking mechanism are added, so that the clutch can be controlled to be separated, combined and the like.

Description

Technical Field

[0001] The present invention relates to a vehicle power system and control technology, and in particular to a hybrid power system for a heavy-duty commercial vehicle and a control method thereof. Background Art

[0002] Currently, in the transportation sector, commercial vehicles are the main contributors to carbon emissions. Compared with traditional fuel vehicles, hybrid vehicles can significantly reduce tail gas emissions, especially emissions of greenhouse gases such as carbon dioxide. Hybrid vehicles can run solely on electricity under certain conditions, reducing fuel consumption, and can also give full play to the high efficiency characteristics of the engine when driving at high speeds; secondly, regenerative braking technology recovers energy and improves energy utilization efficiency. Therefore, from a technical point of view, heavy-duty commercial vehicles used for long-distance trunk transportation are suitable for hybrid technology routes.

[0003] At present, most of the hybrid powertrain systems for heavy-duty commercial vehicles are P2 structures that integrate a drive motor between the clutch and the multi-speed AMT transmission. This structure is developed based on the existing mature AMT, with low development difficulty and cost, but its energy-saving effect is low, and there is power interruption during gear shifting in the P2 hybrid structure, so the driving comfort of the whole vehicle is not good. Summary of the invention

[0004] In view of the defects or shortcomings of the prior art, the present invention provides a hybrid powertrain for a heavy-duty commercial vehicle.

[0005] To this end, the present invention provides a hybrid powertrain for a heavy-duty commercial vehicle, comprising an engine, a clutch, a first motor, a second motor, a planetary gear system, a gearbox system, a housing and a sleeve locking mechanism; the planetary gear system comprises a planetary gear sun gear, a planetary gear carrier and a planetary gear outer gear roll that are meshed; the housing is fixedly arranged, the planetary gear system, the sleeve locking mechanism and the gearbox system are installed in the housing, and the sleeve locking mechanism is fixedly connected to the inner wall of the housing;

[0006] The engine is connected to the planetary gear carrier through a clutch and an output shaft, the planetary gear sun gear is connected to the first motor through a first reduction mechanism, the planetary gear outer ring is connected to the gearbox system, and the second motor is connected to the gearbox system through a second reduction mechanism;

[0007] The gearbox system comprises a first gearbox and a second gearbox, the first gearbox is connected to the second gearbox, the planetary outer gear ring is connected to the first gearbox, and the second motor is connected to the first gearbox via a second reduction mechanism;

[0008] The planetary sun gear is connected to the inner wall of the housing in an on-off manner through a sliding sleeve locking mechanism.

[0009] A preferred solution is that the first motor is arranged outside the housing and the second motor is arranged outside the housing.

[0010] An optional solution is that both the first gearbox and the second gearbox are two-speed gearboxes. Both the first gearbox and the second gearbox adopt a sliding sleeve structure.

[0011] In a specific solution, the hybrid powertrain is suitable for 49-ton heavy-duty commercial vehicles.

[0012] The present invention also provides a control method for the hybrid powertrain for the heavy-duty commercial vehicle, including a pure electric mode, a hybrid mode, a brake energy recovery mode, an engine direct drive mode, and a high-voltage fault limp home mode;

[0013] In pure electric mode, the engine speed is zero, the clutch remains engaged, the first motor idles, and the second motor provides driving force for the vehicle;

[0014] In hybrid mode, the engine is started, the clutch remains engaged, part of the engine power is used to generate electricity for the first motor, and the other part is used to drive the vehicle; the second motor rotates forward to provide electric assistance;

[0015] In the braking energy recovery mode, the engine is started or the speed is zero, the clutch remains engaged, the first motor rotates forward to generate electricity, and the second motor rotates forward to output negative torque and is also in the power generation state. In the pure electric mode and hybrid mode, the whole vehicle performs braking energy recovery;

[0016] When the engine direct drive mode is in progress, the power is provided by the engine, the clutch remains engaged, the control sleeve locking mechanism locks the sun gear of the planetary gear train, the first motor is locked, and the second motor is idling;

[0017] When the high-voltage fault is in limp mode, starting is completed through the cooperation of the engine and the clutch. After the gear is engaged, the clutch is opened from the closed state, and the clutch is controlled to gradually engage. The engine synchronously increases the torque, the whole vehicle completes the start, and the sleeve locking mechanism is controlled to lock the sun gear of the planetary gear train. During driving, the power of the whole vehicle is only provided by the engine.

[0018] The present invention takes into account that the whole vehicle can still be driven when the high-voltage fails, and adds a clutch and a sliding sleeve locking mechanism for locking the sun gear in the planetary gear system to ensure that the clutch can achieve separation and combination and other controls. When the high voltage fails, the sun gear in the planetary gear system is locked, and the engine power can be gradually connected by controlling the clutch sliding film to complete the start of the whole vehicle. During driving, the engine cooperates with the clutch and the gearbox to complete the vehicle shifting. At the same time, when the vehicle speed is high, the sun gear mechanism can be locked, and the engine can be directly driven alone, and the whole vehicle enters the pure engine working mode.

[0019] When the vehicle is in hybrid driving, the power of the first gearbox and the second gearbox are coordinated alternately to ensure that the vehicle is running without interruption. The planetary gear ring outputs power to the input shaft of the first gearbox. When the first gearbox is shifting, the second gearbox connected to the second motor is guaranteed to be in gear, and the second motor drives the motor to output power to ensure the normal driving of the vehicle. When the second gearbox is shifting, the first gearbox is guaranteed to be in gear, and the planetary gear system supplements power to ensure that the vehicle is running without interruption. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the structural principle of the hybrid assembly of the present invention. DETAILED DESCRIPTION

[0021] Unless otherwise specified, the scientific and technical terms used herein are understood according to the knowledge of ordinary technicians in the relevant fields.

[0022] Example:

[0023] The hybrid powertrain system of this embodiment is suitable for a 49-ton heavy-duty commercial vehicle. Figure 1 As shown, it includes an engine 1, a clutch 2, a first motor 6, a second motor 11, a planetary gear system and a gearbox system, a housing 5 and a sliding sleeve locking mechanism 4; the planetary gear system includes a planetary gear sun gear 8, a planetary gear carrier 9 and a planetary gear outer gear roll 10 that are meshed;

[0024] The housing 5 is fixedly arranged, specifically arranged at a suitable position of the vehicle, the planetary gear system, the sleeve locking mechanism 4 and the gearbox system are installed in the housing, and the sleeve locking mechanism 4 is fixedly connected to the inner wall of the housing 5;

[0025] The engine 1 is connected to the planetary gear carrier 9 through the clutch 2 and the output shaft 3, the planetary gear sun gear 8 is connected to the first motor 6 through the first reduction mechanism 7, the planetary gear outer ring 10 is connected to the gearbox system, and the second motor 11 is connected to the gearbox system through the second reduction mechanism 12;

[0026] The planetary sun gear 8 is connected to the inner wall of the housing 5 in an on-off manner through the sliding sleeve locking mechanism 4. Figure 1 As shown, the sliding sleeve locking mechanism 4 moves to the right to lock the planetary gear sun gear 8;

[0027] The gearbox system includes a first gearbox 13 and a second gearbox 14 , the first gearbox is connected to the second gearbox, the planetary outer ring gear 10 is connected to the first gearbox 13 , and the second motor 11 is connected to the first gearbox 13 via a second reduction mechanism 12 .

[0028] The entire powertrain transmits power by combining a planetary gear mechanism with a parallel shaft gearbox without power interruption. The planetary gear mechanism can decouple the engine from the vehicle speed, so that the engine can continuously operate in the optimal economic zone, reducing the high fuel consumption rate of the engine running in the low speed zone. When matched with the Atkinson cycle engine, it can greatly improve the fuel economy of the vehicle; the role of the first reduction mechanism is to match the engine speed with the vehicle speed, and select the appropriate high-speed first motor through a reasonable reduction ratio design; the main role of the second reduction mechanism is to ensure the pure electric drive capability of heavy-duty commercial vehicles, and play a role in reducing speed and increasing torque.

[0029] The first gearbox and the second gearbox of this embodiment are both two-speed gearboxes, and both adopt a sliding sleeve structure. The planetary gear mechanism and the drive motor EM2 cooperate with each other through the first gearbox and the second gearbox to achieve the whole vehicle without power interruption during driving, thereby improving the gear shifting comfort.

[0030] The hybrid powertrain for heavy-duty commercial vehicles of the present invention includes five operating modes, namely, pure electric mode, hybrid mode, brake energy recovery mode, engine direct drive mode and high-voltage fault limp mode, and related control methods:

[0031] In pure electric mode, when the system enters pure electric mode according to the vehicle working condition, the engine 1 speed is zero, the clutch 2 remains engaged, and the power of the second motor 11 is transmitted from the reduction mechanism 12 to the first gearbox 13, and then to the second gearbox 12 through the first gearbox. The second gearbox controls the speed ratio of the second gearbox through the sliding sleeve, and finally transmits the power to the output shaft 13 to provide driving force for the whole vehicle. In this working mode, the second motor 11 is the only power source for the whole vehicle, and the driving torque of the whole vehicle can be adjusted by controlling the torque of the second motor.

[0032] In hybrid mode, when the system enters hybrid mode according to the vehicle working condition, the engine 1 starts, the clutch 2 remains engaged, the power of the engine 1 is input through the clutch 2 and the planetary gear carrier 9 in the planetary gear train mechanism, and the power is split on the planetary gear mechanism, that is, part of the engine power is transmitted to the planetary gear sun gear 8 through the planetary gear carrier 9, and then transmitted to the first motor 6 through the reduction mechanism 5 for driving power generation; part of the power is transmitted to the planetary gear outer gear roll 10 in the planetary gear train for power output, that is, the planetary gear outer gear roll 10 is connected to the first gearbox 13, the power flows into the first gearbox 13, and then transmitted to the output shaft 15 after passing through the second gearbox 14, and the first gearbox and the second gearbox can control their respective speed ratios through the corresponding sliding sleeves. In this working mode, the power source of the whole vehicle is the engine and the second motor, and the engine output power and the second engine power are coupled through the first gearbox and the second gearbox, thereby adjusting the driving torque of the whole vehicle.

[0033] In the braking energy recovery mode, the engine is started or the speed is zero, the clutch remains engaged, the first motor 6 rotates forward to generate electricity, and the second motor 11 rotates forward to output negative torque and is also in a power generation state. In the pure electric mode and hybrid mode, the whole vehicle performs braking energy recovery.

[0034] When the engine direct drive mode is in operation, the power is provided by the engine 1, the clutch remains engaged, the sleeve locking mechanism is controlled to lock the sun gear 8 of the planetary gear train, the first motor is locked, the second motor is idle, the entire planetary gear train becomes a fixed transmission ratio mechanism, and all the engine power is output to the ring gear of the planetary gear train for output.

[0035] When the high-voltage fault occurs in limp home mode (i.e., when the vehicle battery system or motor fails), the motor cannot drive the vehicle, and starting can only be completed through the cooperation of the engine and the clutch. In the event of a high-voltage fault, the clutch opens from a closed state after the gear is engaged. When the driver steps on the accelerator, the vehicle controller controls the clutch to gradually engage, the engine synchronously increases torque, and the vehicle completes starting. At the same time, the sliding sleeve locking mechanism is controlled to lock the sun gear 8 of the planetary gear train. During driving, the power of the vehicle can only be provided by the engine.

[0036] To facilitate maintenance and replacement of the motors, in a preferred embodiment, the first motor and the second motor are both arranged outside the housing.

[0037] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention is described in detail with reference to the aforementioned embodiments, those skilled in the art can still combine the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the invention shall be included in the protection scope of the present invention.

Claims

1. A hybrid powertrain for a heavy-duty commercial vehicle, comprising an engine (1), a clutch (2), a first motor (6), a second motor (11), a planetary gear system and a gearbox system; the planetary gear system comprises a planetary gear sun gear (8), a planetary gear carrier (9) and a planetary gear outer gear roll (10) arranged in meshing arrangement; It is characterized in that It also includes a housing (5) and a sliding sleeve locking mechanism (4); The housing is fixedly arranged, the planetary gear system, the sleeve locking mechanism (4) and the gearbox system are installed in the housing, and the sleeve locking mechanism (4) is fixedly connected to the inner wall of the housing (5); The engine (1) is connected to the planetary gear carrier (9) via a clutch (2) and an output shaft (3); the planetary gear sun gear (8) is connected to the first motor (6) via a first reduction mechanism (7); the planetary gear ring (10) is connected to a gearbox system; and the second motor (11) is connected to the gearbox system via a second reduction mechanism (12); The gearbox system comprises a first gearbox (13) and a second gearbox (14), the first gearbox is connected to the second gearbox, the planetary outer gear ring (10) is connected to the first gearbox (13), and the second motor (11) is connected to the first gearbox (13) via a second reduction mechanism (12); The planetary gear sun gear (8) is connected to the inner wall of the housing (5) in an on-off manner via a sliding sleeve locking mechanism (4).

2. The heavy-duty commercial vehicle hybrid powertrain according to claim 1, characterized in that: The first motor is arranged outside the housing.

3. The hybrid powertrain for a heavy-duty commercial vehicle according to claim 1, characterized in that: The second motor is arranged outside the housing.

4. The heavy-duty commercial vehicle hybrid powertrain according to claim 1, characterized in that: The first gearbox and the second gearbox are both two-speed gearboxes.

5. The hybrid powertrain for a heavy-duty commercial vehicle according to claim 1, characterized in that: The first gearbox and the second gearbox both adopt a sliding sleeve structure.

6. The heavy-duty commercial vehicle hybrid powertrain according to claim 1, characterized in that: The hybrid powertrain is suitable for 49-ton heavy-duty commercial vehicles.

7. The control method for a hybrid powertrain for a heavy commercial vehicle according to any one of claims 1 to 6, characterized in that: Including pure electric mode, hybrid mode, brake energy recovery mode, engine direct drive mode and high-voltage fault limp mode; In pure electric mode, the engine (1) has a rotation speed of zero, the clutch (2) remains engaged, the first motor (6) is idling, and the second motor (11) provides driving force for the entire vehicle; In hybrid mode, the engine (1) is started, the clutch (2) remains engaged, part of the engine power is used to generate electricity for the first motor (6), and the other part is used to drive the vehicle; the second motor (11) is used for forward rotation and electric power assistance; In the braking energy recovery mode, the engine is started or the speed is zero, the clutch (2) remains engaged, the first motor (6) rotates forward to generate electricity, and the second motor (11) rotates forward to output negative torque and is also in a power generation state. In the pure electric mode and the hybrid mode, the whole vehicle performs braking energy recovery; When the engine direct drive mode is in progress, the power is provided by the engine (1), the clutch (2) remains engaged, the sliding sleeve locking mechanism is controlled to lock the sun gear (8) of the planetary gear train, the first motor is locked, and the second motor is idle; When the high-voltage fault limp mode is in progress, starting is accomplished through the cooperation of the engine and the clutch. After the gear is engaged, the clutch is opened from a closed state and the clutch is controlled to gradually engage. The engine synchronously increases torque, the vehicle starts, and the sliding sleeve locking mechanism is controlled to lock the sun gear (8) of the planetary gear train. During driving, the power of the vehicle is only provided by the engine.

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