A torque management system, method and automobile for a four-wheel drive vehicle

Abstract

This invention relates to the field of automotive transmission technology, and particularly to a torque management system, method, and vehicle for four-wheel drive vehicles. The system includes a multi-plate clutch, a torque synchronization mechanism, and a hydraulic control circuit. The torque synchronization mechanism comprises a synchronization mechanism sleeve, an outer input shaft gear hub, and an inner output shaft gear hub. The outer input shaft gear hub is connected to the outer rotating joint of the multi-plate clutch, and the inner output shaft gear hub is connected to the inner rotating joint of the multi-plate clutch. The hydraulic control circuit is configured to control the movement of the synchronization mechanism sleeve, such that the synchronization mechanism sleeve simultaneously connects to both the outer input shaft gear hub and the inner output shaft gear hub, or connects only to the outer rotating joint. The four-wheel drive vehicle torque management system provided in this application effectively increases the upper limit of torque transmission, reduces the wear and overheating risk of the multi-plate clutch, and improves the driving experience.

Description

Technical Field

[0001] This invention relates to the field of automotive transmission technology, and in particular to a torque management system, method, and vehicle for four-wheel drive vehicles. Background Technology

[0002] As people's demands for vehicle performance continue to increase, especially in terms of off-road capability and stability in harsh road conditions, traditional two-wheel drive can no longer meet all needs. Therefore, four-wheel drive systems have been widely used in modern vehicles.

[0003] Four-wheel drive systems are generally classified into full-time four-wheel drive, on-demand four-wheel drive, and part-time four-wheel drive. Among them, on-demand four-wheel drive systems often use a multi-plate clutch torque coupler to achieve automatic switching between two-wheel drive and four-wheel drive. The multi-plate clutch torque coupler has a fast response speed, can quickly adjust the power distribution, and can dynamically adjust the power distribution between the front and rear axles according to road conditions, improving the vehicle's stability and handling in complex road conditions such as wet, slippery, icy, and snowy roads.

[0004] However, existing multi-plate clutches have the following problems:

[0005] (1) Lower torque transmission limit: Due to structural and material limitations, the maximum torque transmission capacity of multi-plate clutch torque couplers is limited. That is, the maximum torque transmitted from the power system to other shafts is limited by the clutch performance, and it is usually impossible to achieve 100% torque transmission.

[0006] (2) Overheating problem under high load: Under long-term and frequent high torque transmission, especially in off-road scenarios where wheel end impacts occur frequently, multi-plate clutches are prone to unexpected slippage, leading to overheating of the discs, which in turn results in limited functionality, performance degradation, or even friction plate burn-out damage.

[0007] (3) In part-time four-wheel drive systems, although the traditional central hard differential lock can transmit 100% of the torque, it requires manual operation by the driver. The connecting parts are engaged due to the transmission of torque, and the vehicle must be parked or put into neutral to complete the switching. In the face of mixed driving conditions, it cannot be automatically and timely triggered and deactivated, and frequent stops are required for switching. Summary of the Invention

[0008] This invention aims to at least partially solve one of the technical problems in the aforementioned technologies, and to this end, proposes a torque management system for four-wheel drive vehicles, comprising:

[0009] Multi-plate clutch, torque synchronization mechanism, and hydraulic control circuit; among which,

[0010] The torque synchronization mechanism includes:

[0011] Synchronization mechanism gear sleeve, outer input shaft gear hub, and inner output shaft gear hub;

[0012] The outer input shaft gear hub is connected to the outer rotating pair of the multi-plate clutch, and the inner output shaft gear hub is connected to the inner rotating pair of the multi-plate clutch.

[0013] The hydraulic control circuit is configured to control the movement of the synchronizing mechanism sleeve, such that the synchronizing mechanism sleeve is simultaneously connected to the outer input shaft hub and the inner output shaft hub, or that the synchronizing mechanism sleeve is only connected to the outer rotary pair.

[0014] Furthermore, the outer input shaft hub and the inner output shaft hub have the same central axis, and the outer input shaft hub and the inner output shaft hub are connected by an end face bearing.

[0015] Furthermore, the hydraulic control circuit includes:

[0016] Hydraulic pumps, directional valves, and hydraulic actuators; among which,

[0017] The hydraulic actuator is connected to the gear sleeve of the synchronization mechanism;

[0018] The hydraulic actuator is also connected to the hydraulic pump via the reversing valve;

[0019] The hydraulic actuator operates with the hydraulic flow direction opposite when the directional valve is in the first working position to the hydraulic flow direction when the directional valve is in the second working position.

[0020] Furthermore, the outlet of the liquid pump is also connected to the hydraulic chamber of the multi-plate clutch;

[0021] The hydraulic control circuit further includes: a first check valve disposed between the outlet of the hydraulic pump and the inlet of the reversing valve, a second check valve disposed between the outlet of the hydraulic pump and the inlet of the hydraulic chamber, and a pressure relay.

[0022] The pressure relay is configured as follows:

[0023] When the hydraulic pressure value of the hydraulic control circuit is detected to be greater than the threshold, a signal is transmitted to the vehicle ECU to control the reversing valve to switch its working position.

[0024] Furthermore, the vehicle ECU is also configured to adjust the speed of the hydraulic pump according to the speed difference between the front and rear axles of the vehicle when the synchronizing mechanism sleeve is only connected to the external rotating pair.

[0025] Furthermore, the hydraulic control circuit also includes a pressure accumulator disposed between the oil outlet of the second check valve and the liquid inlet of the hydraulic chamber.

[0026] Furthermore, the directional valve is a three-position four-way directional valve.

[0027] Furthermore, the system also includes: a manual control switch;

[0028] The manual control switch is configured as follows:

[0029] In response to user operations, the movement of the synchronizing mechanism sleeve is controlled so that the synchronizing mechanism sleeve is simultaneously connected to the outer input shaft hub and the inner output shaft hub, or so that the synchronizing mechanism sleeve is only connected to the outer rotary pair.

[0030] This application also proposes a torque management method for four-wheel drive vehicles, including:

[0031] Torque management for four-wheel drive vehicles is based on the aforementioned four-wheel drive vehicle torque management system.

[0032] This application also proposes a vehicle equipped with the aforementioned four-wheel drive vehicle torque management system.

[0033] Compared with the prior art, the beneficial effects of the present invention are:

[0034] 1. The torque management system for four-wheel drive vehicles provided in this application can significantly enhance the off-road capability of vehicles: it can automatically switch the torque synchronization mechanism as needed, and the theoretical upper limit of the transmission torque can reach 100%, which can significantly improve the maximum torque transmission capability and enhance the vehicle's ability to pass through complex terrain, especially on low-traction surfaces such as mud and snow.

[0035] 2. In situations where high torque transmission is required, the torque synchronization mechanism of the four-wheel drive vehicle torque management system provided in this application can automatically intervene to reduce the risk of hydraulic clutch overheating.

[0036] 3. The torque management system for four-wheel drive vehicles provided in this application can improve the driving experience: Through this system, drivers can also select the appropriate driving mode according to their own needs or the current road conditions, thereby obtaining a better driving experience.

[0037] 4. In the four-wheel drive vehicle torque management system provided in this application, high torque usage scenarios are handled by the torque synchronization mechanism, which optimizes the working conditions of the clutch, reduces wear caused by overuse, and extends the overall lifespan of the system.

[0038] 5. The torque management system for four-wheel drive vehicles provided in this application can realize a variety of protection mechanisms, such as overheat protection and fault detection, to ensure the safety and durability of the system, improve the safety performance of the vehicle, and ensure the safety of the driver's life and property.

[0039] 6. The torque management system for four-wheel drive vehicles provided in this application adopts a combination of a multi-plate clutch and a mechanical synchronizer. The presence of the torque synchronization mechanism makes the process from flexible connection to hard connection smoother, thus improving driving comfort.

[0040] 7. The torque management system for four-wheel drive vehicles provided in this application does not require stopping or parking when automatically engaging the synchronization mechanism. By pressurizing the hydraulic clutch, the input and output shafts are made to move at the same speed, and then the torque synchronization mechanism is directly engaged, improving the ease of operation.

[0041] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention can be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings. The technical solutions of the invention will be further described below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0042] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0043] Figure 1 This is a schematic diagram of a torque management system for a four-wheel drive vehicle, provided as an example.

[0044] Figure 2 This is a schematic diagram of the flexible transmission operation of a multi-plate clutch as shown in the embodiment.

[0045] Figure 3 This is a schematic diagram of the synchronous mechanism tooth sleeve engagement process given in the embodiment;

[0046] Figure 4 This is a schematic diagram of the decoupling process of the synchronizing mechanism gear sleeve given in the embodiment;

[0047] Figure 5 The following is a logic diagram of the working position switching of a three-position four-way directional valve, as shown in the embodiment.

[0048] Reference numerals in the attached figures: 1. First check valve; 2. Second check valve; 3. Pressure relay; 4. Three-position four-way directional valve; 5. Hydraulic chamber; 6. Multi-plate clutch; 7. Pressure accumulator; 8. Hydraulic actuator; 9. Synchronizing mechanism gear sleeve; 10. External input shaft gear hub; 11. Internal output shaft gear hub. Detailed Implementation

[0049] The present invention will be described below with reference to the accompanying drawings. The preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0050] like Figure 1 As shown, this application proposes a torque management system for a four-wheel drive vehicle, including:

[0051] 6. Multi-plate clutch, torque synchronization mechanism and hydraulic control circuit; among which,

[0052] The torque synchronization mechanism includes:

[0053] Synchronization mechanism gear sleeve 9, external input shaft gear hub 10 and internal output shaft gear hub 11;

[0054] The outer input shaft gear hub 10 is connected to the outer rotating joint of the multi-plate clutch 6, and the inner output shaft gear hub 11 is connected to the inner rotating joint of the multi-plate clutch 6.

[0055] The hydraulic control circuit is configured to control the movement of the synchronizing mechanism sleeve 9, so that the synchronizing mechanism sleeve 9 is simultaneously connected to the outer input shaft hub 10 and the inner output shaft hub 11, or so that the synchronizing mechanism sleeve 9 is only connected to the outer rotary pair.

[0056] Furthermore, the outer input shaft hub 10 and the inner output shaft hub 11 have the same central axis, and the outer input shaft hub 10 and the inner output shaft hub 11 are connected by end face bearings.

[0057] According to some embodiments of this application, such as Figure 1 As shown, the torque management system for a four-wheel drive vehicle provided in this application includes: a multi-plate clutch 6, a torque synchronization mechanism, and a hydraulic control circuit. The multi-plate clutch 6 includes inner and outer rotating pairs, wherein the outer rotating pair includes a clutch steel plate disc, the inner rotating pair includes a clutch friction plate disc, and a hydraulic chamber 5 is provided between the inner and outer rotating pairs; the torque synchronization mechanism includes: a synchronization mechanism sleeve 9, an outer input shaft gear hub 10 of the synchronization mechanism, and an inner output shaft gear hub 11 of the synchronization mechanism, with the inner and outer shaft gear hubs connected by end face bearings; the hydraulic control circuit is used to control the synchronization mechanism sleeve 9, thereby controlling the connection and separation of the inner and outer shaft gear hubs.

[0058] Furthermore, the hydraulic control circuit includes:

[0059] 8 hydraulic pumps, directional valves, and hydraulic actuators; among which,

[0060] The hydraulic actuator 8 is connected to the synchronizing mechanism sleeve 9;

[0061] The hydraulic actuator 8 is also connected to the hydraulic pump via a directional valve;

[0062] The hydraulic actuator 8 has the opposite hydraulic flow direction when the directional valve is in the first working position to the hydraulic flow direction when the directional valve is in the second working position.

[0063] Furthermore, the outlet of the liquid pump is also connected to the hydraulic chamber 5 of the multi-plate clutch 6;

[0064] The hydraulic control circuit also includes: a first check valve 1 located between the outlet of the hydraulic pump and the inlet of the reversing valve, a second check valve 2 located between the outlet of the hydraulic pump and the inlet of the hydraulic chamber 5, and a pressure relay 3.

[0065] Pressure relay 3 is configured as follows:

[0066] When the hydraulic pressure value of the hydraulic control circuit is detected to be greater than the threshold, a signal is transmitted to the vehicle ECU to enable it to control the directional valve to switch its working position.

[0067] According to some embodiments of this application, such as Figure 1 As shown, the hydraulic control circuit includes: a hydraulic pump, a hydraulic actuator 8, a directional valve, a check valve, a pressure relay 3, and a relief valve. The hydraulic actuator 8 is connected to the synchronizing mechanism sleeve 9. The hydraulic actuator 8 moves under the drive of the hydraulic pump, which drives the synchronizing mechanism sleeve 9 to move, thereby controlling the connection and disconnection between the inner output shaft hub 11 and the outer output shaft hub. The hydraulic actuator 8 is connected to the hydraulic pump through a reversing valve. The reversing valve has at least two working positions. In the two working positions, the movement state of the extension and retraction mechanism of the hydraulic actuator 8 is opposite. That is, the reversing valve is used to control the extension and retraction of the hydraulic actuator 8. The outlet of the hydraulic pump is also connected to the hydraulic chamber 5 of the multi-plate clutch 6. The hydraulic pressure in the hydraulic chamber 5 is controlled to control the torque transmitted by the clutch. A check valve is provided between the outlet of the hydraulic pump and the inlet of the reversing valve. Another check valve is provided between the outlet of the hydraulic pump and the hydraulic chamber 5. The presence of the check valve causes the hydraulic pressure value of the hydraulic control circuit to continuously increase. When the hydraulic pressure value reaches the threshold, the pressure relay 3 sends a signal to the control module (in this embodiment, the vehicle ECU) to control the switching of the working position of the reversing valve, thereby changing the connection state between the inner output shaft hub 11 and the outer output shaft hub.

[0068] Furthermore, the vehicle ECU is also configured to adjust the speed of the hydraulic pump according to the speed difference between the front and rear axles of the vehicle when the synchronizing mechanism sleeve 9 is only connected to the external rotating joint.

[0069] According to some embodiments of this application, the multi-plate clutch 6 is mounted on the drive shaft. When the synchronizing mechanism sleeve 9 is only connected to the outer rotating pair (i.e., the synchronizing mechanism sleeve 9 is not engaged and the torque management system of the four-wheel drive vehicle is in the on-demand four-wheel drive mode), the hydraulic control circuit controls the clutch pressure by adjusting the oil pump speed, thereby adjusting the magnitude of the torque transmitted by the clutch.

[0070] Furthermore, the hydraulic control circuit also includes a pressure accumulator 7 located between the oil outlet of the second check valve 2 and the liquid inlet of the hydraulic chamber 5.

[0071] According to some embodiments of this application, a pressure accumulator 7 is also provided in the hydraulic control circuit. When the working position of the directional valve is switched, the hydraulic circuit of the hydraulic actuator 8 is reversed, the pressure of the hydraulic control circuit changes, and the pressure accumulator 7 is used to maintain the pressure of the hydraulic control circuit.

[0072] Furthermore, the directional valve is a three-position four-way directional valve 4.

[0073] According to some embodiments of this application, such as Figure 1 As shown, the directional valve is a three-position four-way directional valve 4. When the directional valve is in the left position, the hydraulic actuator 8 receives oil; when the directional valve is in the right position, the hydraulic actuator 8 discharges oil; when the directional valve is in the neutral position, the hydraulic circuit of the hydraulic actuator 8 is cut off.

[0074] Figure 2 The principle of flexible transmission of the multi-plate clutch 6 is shown: the pressure relay 3 is in the closed state, the three-position four-way directional valve 4 is in the middle position, the hydraulic pump output supplies oil to the hydraulic circuit of the multi-plate clutch 6 through the first check valve 1 and the second check valve 2, so that the pressure accumulator 7 is charged, and at the same time the pressure chamber of the multi-plate clutch 6 is pressurized, and the inner rotating pair and the outer rotating pair of the multi-plate clutch 6 are gradually pressed together to realize the transmission of torque. The magnitude of the transmitted torque is positively correlated with the tightness of the contact of the rotating pair. At this time, the magnitude of the transmitted torque can be controlled by adjusting the speed of the hydraulic pump.

[0075] Figure 3 The principle of the engagement process of the synchronizing mechanism sleeve 9 is illustrated: When the hydraulic circuit pressure of the multi-plate clutch 6 rises to a threshold, it triggers the pressure relay 3. The control module (in this embodiment, the vehicle ECU) makes a decision based on the position of the synchronizing mechanism sleeve 9. If the synchronizing mechanism sleeve 9 only engages with the outer input shaft hub 10, the control module controls the three-position four-way directional valve 4 to enter the left position, opening the hydraulic circuit of the hydraulic actuator 8. The hydraulic circuit of the multi-plate clutch 6 maintains pressure through the pressure accumulator 7. Hydraulic fluid enters from the right side of the hydraulic actuator 8, the telescopic mechanism moves to the left, driving the synchronizing mechanism sleeve 9 to move and engage with the inner output shaft hub 11. After the synchronizing mechanism sleeve 9 moves to the end of its stroke, the pressure relay 3 controls the three-position four-way directional valve 4 to return to the middle position through the control module, locking the synchronizing mechanism sleeve 9, thus forming a hard connection between the inner output shaft and the outer input shaft, suitable for high torque transmission conditions.

[0076] Figure 4 The principle of the decoupling process of the synchronizing mechanism sleeve 9 is shown: When the three-position four-way directional valve 4 is in the neutral position, the hydraulic pump continues to run, causing the pressure in the hydraulic circuit to gradually increase. When the pressure reaches the threshold, the pressure relay 3 is triggered. The control module makes a decision based on the position of the synchronizing mechanism sleeve 9. If the synchronizing mechanism sleeve 9 is simultaneously engaged with the outer input shaft hub 10 and the inner output shaft hub 11, the control module controls the three-position four-way directional valve 4 to run to the right position. The hydraulic actuator 8 reverses the inlet and outlet hydraulic circuits, the telescopic mechanism moves to the right, and drives the synchronizing mechanism sleeve 9 to disengage. At the same time, the pressure in the pressure chamber of the multi-plate clutch 6 increases, gradually taking over the torque transmission path, ensuring that the synchronizing mechanism sleeve 9 can be smoothly pushed out from the inner output shaft hub 11, and the outer input shaft and inner output shaft are disconnected.

[0077] comprehensive Figures 2-4The given technical solution provides the switching logic for the four working positions of the three-position four-way directional valve, as follows: Figure 5 As shown.

[0078] Furthermore, the system also includes: a manual control switch;

[0079] The manual control switch is configured as follows:

[0080] In response to user operations, the movement of the synchronizing mechanism gear sleeve 9 is controlled, so that the synchronizing mechanism gear sleeve 9 is simultaneously connected to the outer input shaft gear hub 10 and the inner output shaft gear hub 11, or the synchronizing mechanism gear sleeve 9 is only connected to the outer rotary pair.

[0081] According to some embodiments of this application, the control mechanism corresponding to the synchronization mechanism sleeve 9 can be a device that can be manually or automatically controlled. When the system pressure reaches the threshold, or when the driver selects the full-time four-wheel drive mode, the synchronization mechanism sleeve 9 simultaneously engages the inner output shaft hub 11 and the outer output shaft hub to rigidly connect the front and rear axles and achieve maximum torque transmission.

[0082] In summary, the conduction position of the three-position four-way directional valve 4 is controlled by the pressure relay 3 via the vehicle ECU, or it can be actively controlled by the user. After the synchronizing mechanism sleeve 9 is engaged or disengaged, the three-position four-way directional valve 4 returns to the neutral position to lock the synchronizing mechanism sleeve 9. When the synchronizing mechanism sleeve 9 is not engaged, the ECU, based on road condition feedback and signals such as vehicle speed and wheel speed, controls the engagement state of the multi-plate clutch 6 by controlling the hydraulic pump speed to adjust the torque distribution between the front and rear axles. At this time, the torque management system of the four-wheel drive vehicle is in an on-demand four-wheel drive state. When the synchronizing mechanism sleeve 9 is engaged, the torque management system of the four-wheel drive vehicle switches to a full-time four-wheel drive state. The front and rear axles are rigidly connected through the synchronizing mechanism sleeve 9, enabling greater torque transmission to cope with more severe road conditions.

[0083] This application also proposes a torque management method for four-wheel drive vehicles, including:

[0084] Torque management for four-wheel drive vehicles is based on the aforementioned four-wheel drive vehicle torque management system.

[0085] This application also proposes a vehicle equipped with the aforementioned four-wheel drive vehicle torque management system.

[0086] It is obvious that those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A torque management system for a four-wheel drive vehicle, characterized in that, include: Multi-plate clutch (6), torque synchronization mechanism and hydraulic control circuit; among which, The torque synchronization mechanism includes: Synchronization mechanism gear sleeve (9), external input shaft gear hub (10) and internal output shaft gear hub (11); The outer input shaft gear hub (10) is connected to the outer rotating pair of the multi-plate clutch (6), and the inner output shaft gear hub (11) is connected to the inner rotating pair of the multi-plate clutch (6). The hydraulic control circuit is configured to control the movement of the synchronizing mechanism sleeve (9) so that the synchronizing mechanism sleeve (9) is simultaneously connected to the outer input shaft hub (10) and the inner output shaft hub (11), or so that the synchronizing mechanism sleeve (9) is only connected to the outer rotary pair. The hydraulic control circuit includes: Hydraulic pump, directional valve and hydraulic actuator (8); among which, The hydraulic actuator (8) is connected to the synchronous mechanism sleeve (9); The hydraulic actuator (8) is also connected to the hydraulic pump via the directional valve; The hydraulic actuator (8) has the opposite hydraulic flow direction when the directional valve is in the first working position to the hydraulic flow direction when the directional valve is in the second working position. The outlet of the liquid pump is also connected to the hydraulic chamber (5) of the multi-plate clutch (6); The hydraulic control circuit further includes: a first check valve (1) disposed between the outlet of the hydraulic pump and the inlet of the reversing valve, a second check valve (2) disposed between the outlet of the hydraulic pump and the inlet of the hydraulic chamber (5), and a pressure relay (3). The pressure relay (3) is configured as follows: When the hydraulic pressure value of the hydraulic control circuit is detected to be greater than the threshold, a signal is transmitted to the vehicle ECU to control the reversing valve to switch its working position. The hydraulic control circuit further includes a pressure accumulator (7) disposed between the oil outlet of the second check valve (2) and the liquid inlet of the hydraulic chamber (5).

2. The torque management system for four-wheel drive vehicles as described in claim 1, characterized in that, The outer input shaft hub (10) and the inner output shaft hub (11) have the same central axis, and the outer input shaft hub (10) and the inner output shaft hub (11) are connected by an end face bearing.

3. The torque management system for four-wheel drive vehicles as described in claim 1, characterized in that, The vehicle ECU is also configured to adjust the speed of the hydraulic pump according to the speed difference between the front and rear axles of the vehicle when the synchronizing mechanism sleeve (9) is only connected to the external rotary joint.

4. The torque management system for four-wheel drive vehicles as described in claim 1, characterized in that, The reversing valve is a three-position four-way reversing valve (4).

5. The torque management system for four-wheel drive vehicles as described in any one of claims 1-4, characterized in that, The system also includes: a manual control switch; The manual control switch is configured as follows: In response to the user's operation, control the movement of the synchronization mechanism sleeve (9) so that the synchronization mechanism sleeve (9) is connected to both the outer input shaft hub (10) and the inner output shaft hub (11) at the same time, or so that the synchronization mechanism sleeve (9) is connected to only the outer rotary pair.

6. A torque management method for a four-wheel drive vehicle, characterized in that, include: Torque management of four-wheel drive vehicles is performed based on the torque management system for four-wheel drive vehicles as described in any one of claims 1-5.

7. A car, characterized in that, The vehicle is equipped with a four-wheel drive vehicle torque management system as described in any one of claims 1-5.

Images