Hydraulic torque converter control method and apparatus

Abstract

The application provides a hydraulic torque converter control method and device, and belongs to the field of automobile gearbox control. When current vehicle parameters meet preset conditions, especially when the current vehicle speed is within a preset vehicle speed range, the clutch in the hydraulic torque converter is controlled to switch to a sliding friction state, that is, a semi-linked state. In this state, the engine can stop fuel injection, and the engine can also be prevented from stalling due to low wheel speed dragging the engine or the engine losing connection with the wheels. In summary, the engine can continue to be fuel cut on the basis of avoiding engine stall, the fuel cut time is prolonged, and oil consumption is further reduced.

Description

Technical Field

[0001] This application relates to the field of automotive transmission control, and in particular to a hydraulic torque converter control method and device. Background Technology

[0002] With advancements in manufacturing and rising living standards, car ownership is growing rapidly. Consumers are increasingly demanding higher standards for their vehicles, such as lower fuel consumption. Furthermore, with the government's growing emphasis on non-renewable resources, increasingly stringent regulations have been introduced to control vehicle emissions and fuel consumption.

[0003] To reduce fuel consumption in automobiles, major manufacturers have begun developing various corresponding technologies, such as low-speed fuel cut-off technology. Existing low-speed fuel cut-off technologies generally stop fuel injection into the engine when the vehicle is coasting and the driver is not pressing the accelerator pedal. They maintain the torque converter clutch engaged and rely on the rotation of the wheels to drive the engine in the opposite direction, thus reducing fuel consumption.

[0004] However, when the vehicle coasts and slowly decelerates to a certain speed, in order to prevent the engine from stalling due to excessively low wheel speed, the torque converter clutch needs to be disengaged. After disengagement, since the connection between the engine and the wheels is broken, the rotation of the wheels cannot continue to drive the engine in the opposite direction. Therefore, the engine needs to resume fuel injection to avoid stalling, and it is impossible to further reduce fuel consumption. Summary of the Invention

[0005] In view of this, this application provides a hydraulic torque converter control method and device that can extend the engine fuel cut-off time and further reduce fuel consumption.

[0006] Specifically, the following technical solutions are included:

[0007] In a first aspect, this application provides a hydraulic torque converter control method, the method comprising:

[0008] Get the current vehicle parameters, including the current vehicle speed.

[0009] Determine whether the current vehicle parameters meet the preset conditions, including that the current vehicle speed is within the preset speed range.

[0010] When it is determined that the current vehicle parameters meet the preset conditions, the clutch in the hydraulic torque converter is switched to the sliding friction state.

[0011] Optionally, the preset conditions include a first sub-condition, a second sub-condition, and a third sub-condition. The current vehicle parameters satisfy the preset conditions when all three sub-conditions are met simultaneously. These current vehicle parameters also include the sliding friction indicator, transmission controller status, driving mode, sliding friction accumulation time, and transmission oil temperature. The current vehicle parameters satisfy the first sub-condition when all of the following conditions are met simultaneously:

[0012] The current vehicle speed is within the preset speed range, the sliding friction indicator is at the preset value, the transmission control status is fault-free, the driving mode is not sport mode, the cumulative sliding friction time is less than the preset time, and the transmission oil temperature is within the preset temperature range.

[0013] Optionally, the current vehicle parameters may also include the engagement point self-learning flag, engine speed, engine speed change rate, engine torque, accelerator pedal opening, engine-turbo speed difference, and the current state of the torque converter clutch. If the current vehicle parameters satisfy the first sub-condition and further simultaneously satisfy all of the following conditions, then the current vehicle parameters satisfy the second sub-condition:

[0014] The engagement point self-learning flag is set to a preset value, the engine speed is within a preset speed range, the engine speed change rate is lower than a preset change rate range, the engine torque is within a preset torque range, the accelerator pedal opening is less than a preset opening, the difference between engine and turbine speeds is less than a preset speed difference, and the current state of the clutch is engaged.

[0015] Optionally, the current vehicle parameters also include an execution flag. If the current vehicle parameters satisfy the first and second sub-conditions, and further simultaneously satisfy all of the following conditions, then the current vehicle parameters satisfy the third sub-condition:

[0016] The execution flag is set to a preset value, and the current vehicle speed is within a preset speed range.

[0017] Alternatively, after controlling the clutch in the hydraulic torque converter to switch to a sliding friction state, the method further includes:

[0018] The control current is determined based on the current vehicle parameters.

[0019] The solenoid valve in the clutch of the hydraulic torque converter is controlled in real time according to the control current to keep the clutch in a sliding friction state.

[0020] Secondly, this application provides a hydraulic torque converter control device, characterized in that the device comprises:

[0021] The acquisition module is configured to acquire current vehicle parameters, including the current vehicle speed.

[0022] The judgment module is configured to determine whether the current vehicle parameters meet preset conditions, including that the current vehicle speed is within a preset speed range.

[0023] The control module is configured to switch the clutch in the hydraulic torque converter to a sliding friction state when it is determined that the current vehicle parameters meet the preset conditions.

[0024] Optionally, the preset conditions include a first sub-condition, a second sub-condition, and a third sub-condition. The current vehicle parameters satisfy the preset conditions when all three sub-conditions are met simultaneously. These current vehicle parameters also include the sliding friction indicator, transmission controller status, driving mode, sliding friction accumulation time, and transmission oil temperature. The current vehicle parameters satisfy the first sub-condition when all of the following conditions are met simultaneously:

[0025] The current vehicle speed is within the preset speed range, the sliding friction indicator is at the preset value, the transmission control status is fault-free, the driving mode is not sport mode, the cumulative sliding friction time is less than the preset time, and the transmission oil temperature is within the preset temperature range.

[0026] Optionally, the current vehicle parameters may also include the engagement point self-learning flag, engine speed, engine speed change rate, engine torque, accelerator pedal opening, engine-turbo speed difference, and the current state of the torque converter clutch. If the current vehicle parameters satisfy the first sub-condition and further simultaneously satisfy all of the following conditions, then the current vehicle parameters satisfy the second sub-condition:

[0027] The engagement point self-learning flag is set to a preset value, the engine speed is within a preset speed range, the engine speed change rate is lower than a preset change rate range, the engine torque is within a preset torque range, the accelerator pedal opening is less than a preset opening, the difference between engine and turbine speeds is less than a preset speed difference, and the current state of the clutch is engaged.

[0028] Optionally, the current vehicle parameters also include an execution flag. If the current vehicle parameters satisfy the first and second sub-conditions, and further simultaneously satisfy all of the following conditions, then the current vehicle parameters satisfy the third sub-condition:

[0029] The execution flag is set to a preset value, and the current vehicle speed is within a preset speed range.

[0030] Alternatively, the control module is also configured to determine the control current based on the current vehicle parameters after the clutch in the torque converter switches to a sliding friction state, and to control the solenoid valve in the clutch of the torque converter in real time based on the control current so as to keep the clutch in a sliding friction state.

[0031] By using the hydraulic torque converter control method and device provided in this application, when the current vehicle parameters meet the preset conditions, especially when the current vehicle speed is within the preset vehicle speed range, the clutch in the hydraulic torque converter is controlled to switch to the sliding friction state, i.e., the semi-engaged state. At this time, it can avoid the engine stalling due to the low wheel speed, and it can also avoid the engine stalling due to the loss of connection between the engine and the wheels. In short, it can continue to keep the engine fuel cut-off while avoiding engine stalling, and extend the fuel cut-off time, thereby further reducing fuel consumption. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 A flowchart of the hydraulic torque converter control method provided in the embodiments of this application;

[0034] Figure 2 Another flowchart of the hydraulic torque converter control method provided in the embodiments of this application;

[0035] Figure 3 This is a structural diagram of the electro-hydraulic torque converter control device provided in an embodiment of this application. Detailed Implementation

[0036] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0037] This application provides a hydraulic torque converter control method that can extend the oil cut-off time, thereby further reducing fuel consumption, such as... Figure 1 As shown, the method includes steps S101, S102, and S103, wherein:

[0038] In step S101, the current vehicle parameters are obtained, including the current vehicle speed.

[0039] In step S102, it is determined whether the current vehicle parameters meet the preset conditions, wherein the preset conditions include the current vehicle speed being within the preset vehicle speed range.

[0040] In step S103, when it is determined that the current vehicle parameters meet the preset conditions, the clutch in the hydraulic torque converter is controlled to switch to the sliding friction state.

[0041] Using the hydraulic torque converter control method provided in this application, when the current vehicle parameters meet the preset conditions, especially when the current vehicle speed is within the preset vehicle speed range, the clutch in the hydraulic torque converter is controlled to switch to a sliding friction state, i.e. a semi-engaged state. In this state, the engine can stop injecting fuel, while avoiding engine stalling due to low wheel speed dragging the engine or engine stalling due to loss of connection with the wheels. In short, the engine can continue to cut off fuel while avoiding engine stalling, extending the fuel cut-off time, thereby further reducing fuel consumption.

[0042] This application also provides another hydraulic torque converter control method, executed by the vehicle controller. The following description uses the vehicle controller as an example. Figure 2 As shown, the method includes steps S201, S202, S203, S204, and S205, wherein:

[0043] In step S201, the vehicle controller acquires the current vehicle parameters.

[0044] Understandably, the vehicle controller can directly obtain some current vehicle parameters stored in the vehicle controller, and can also indirectly obtain some current vehicle parameters from devices such as the transmission controller and anti-lock braking system.

[0045] It is understandable that at higher speeds, the engine can be driven in the opposite direction by the wheels, which is suitable for keeping the torque converter clutch in a closed state, without requiring the torque converter clutch to enter a sliding friction state. Conversely, at speeds low enough to a certain extent, the clutch must be fully disengaged to prevent the engine from stalling, and after the clutch disengages, the engine needs to resume fuel injection. At moderate speeds, the control method provided in this application embodiment can be used. In other words, when the vehicle is in a specific speed range, it is most appropriate to stop engine fuel injection, allowing the torque converter clutch to enter a sliding friction state, i.e., a semi-engaged state, and putting the vehicle into a coasting mode, thereby preventing the vehicle from stalling while extending the engine fuel cut-off time as much as possible (when the torque converter clutch is in a semi-engaged state, the engine does not need to resume fuel injection). Therefore, before determining whether a fuel cut-off coasting operation can be performed, it is necessary to pre-determine whether the vehicle's current speed meets the preset conditions. Therefore, the current vehicle parameters include the current vehicle speed, which can be obtained by the anti-lock braking system and sent to the vehicle controller via the CAN bus.

[0046] In step S202, the vehicle controller determines whether the current vehicle parameters meet the preset conditions.

[0047] In some optional embodiments, the preset conditions include the current vehicle speed being within a preset speed range, which may be from 10 km / h to 30 km / h.

[0048] More specifically, the preset conditions may include multiple sub-conditions, and the preset conditions are considered satisfied only when all of these sub-conditions are met. In some optional embodiments, the preset conditions include a first sub-condition, a second sub-condition, and a third sub-condition. When the current vehicle parameters simultaneously satisfy the first sub-condition, the second sub-condition, and the third sub-condition, the current vehicle parameters satisfy the preset conditions.

[0049] In some optional embodiments, the first sub-condition, the second sub-condition, and the third sub-condition can be in a progressive relationship, that is, to satisfy the second sub-condition, the first sub-condition must be satisfied beforehand, and to satisfy the third sub-condition, the second sub-condition and the first sub-condition must be satisfied.

[0050] The current vehicle parameters also include the sliding friction indicator, transmission controller status, driving mode, cumulative sliding friction time, and transmission oil temperature.

[0051] The sliding friction indicator is a binary bit used to determine the user's initial intention to activate the sliding friction function. Its value is determined based on the user's specific selection on the in-vehicle central control screen and stored in the vehicle controller. A switch control corresponding to the sliding friction function can be pre-displayed on the in-vehicle central control screen. When the user touches this switch control to activate the sliding friction function, the vehicle controller sets the sliding friction indicator to 1 and stores it. Similarly, when the user touches the switch control to deactivate the sliding friction function, the vehicle controller sets the sliding friction indicator to 0 and stores it.

[0052] The first sub-condition is met when all of the following conditions are simultaneously satisfied:

[0053] The current vehicle speed is within the preset speed range, the sliding friction indicator is at the preset value, the transmission control status is fault-free, the driving mode is not sport mode, the cumulative sliding friction time is less than the preset time, and the transmission oil temperature is within the preset temperature range.

[0054] The following section details the design approach for each subordinate condition within the first sub-condition:

[0055] Understandably, it is only appropriate to stop engine fuel injection when the vehicle is within the preset speed range, so that the torque converter clutch enters a sliding friction state, i.e. a semi-engaged state, and the vehicle enters a coasting mode, thereby extending the engine fuel cut-off time as much as possible while avoiding the vehicle from stalling.

[0056] The sliding friction indicator is set to a preset value, which can be 1. If the sliding friction indicator is set to a preset value, it means that the user has previously switched the sliding friction function to the on state via the touch switch control on the vehicle's central control screen. In other words, the user has a preliminary intention to enable the sliding friction function.

[0057] If the transmission control status is fault-free, it means that the clutch of the hydraulic torque converter in the transmission can be normally controlled to enter the sliding friction state.

[0058] If the driving mode is not Sport mode, it indicates that the driver has a less aggressive driving style and lower demand on power and transmission response, thus prioritizing fuel efficiency.

[0059] Because the clutch of the torque converter is in a state of sliding friction, the clutch disc will wear, and the friction heat will cause the transmission oil in the torque converter to heat up. From the perspective of protecting the torque converter, the clutch of the torque converter can only continue to be in a state of sliding friction if the cumulative time of sliding friction is less than a preset time and the transmission oil temperature is within a preset temperature range.

[0060] In some optional embodiments, the current vehicle parameters also include engagement point self-learning flag, engine speed, engine speed change rate, engine torque, accelerator pedal opening, engine-turbo speed difference, and the current state of the torque converter clutch.

[0061] Similar to the sliding friction indicator, the engagement point self-learning indicator is a binary bit used to determine the user's intention to enable the engagement point self-learning function. Its value is determined based on the user's specific selection on the in-vehicle central control screen and stored in the vehicle controller. A switch control corresponding to the engagement point self-learning function can be pre-displayed on the in-vehicle central control screen. When the user touches this switch control to enable the engagement point self-learning function, the vehicle controller sets the engagement point self-learning indicator to 1 and stores it. Similarly, when the user touches this switch control to disable the engagement point self-learning function, the vehicle controller sets the engagement point self-learning indicator to 0 and stores it.

[0062] Engagement point self-learning refers to determining the clutch pressure corresponding to the engagement point of the hydraulic torque converter's clutch, and determining the current value of the solenoid valve of the clutch corresponding to that pressure.

[0063] The engine-turbine speed difference refers to the speed difference between the engine and the turbine of the hydraulic torque converter.

[0064] Since the first and second sub-conditions are progressive, satisfying the second sub-condition requires satisfying additional advanced conditions beyond the first. Specifically, if the current vehicle parameters satisfy the first sub-condition and simultaneously satisfy all of the following conditions, then the current vehicle parameters satisfy the second sub-condition:

[0065] The engagement point self-learning flag is set to a preset value, the engine speed is within a preset speed range, the engine speed change rate is lower than a preset change rate range, the engine torque is within a preset torque range, the accelerator pedal opening is less than a preset opening, the difference between engine and turbine speeds is less than a preset speed difference, and the current state of the clutch is engaged.

[0066] The following section details the design approach for each subordinate condition within the second sub-condition:

[0067] The self-learning flag is set to a preset value. A preset value of 1 indicates that the user has enabled the self-learning function by touching the switch control. In other words, the user has the intention to enable the self-learning function.

[0068] Furthermore, the engine speed is within the preset speed range, the engine speed change rate is lower than the preset change rate range, the engine torque is within the preset torque range, the accelerator pedal opening is less than the preset opening, and the difference between the engine and turbine speeds is less than the preset speed. These lower-level conditions are all to ensure the accuracy of the self-learning of the engagement point.

[0069] If the clutch is currently engaged, it means that the clutch can be switched from the engaged state to the sliding friction state, or directly switched to the disengaged state.

[0070] In some optional embodiments, the current vehicle parameters also include an execution flag bit.

[0071] Similar to the sliding friction flag and the self-learning flag at the engagement point, the execution flag is a binary bit used to determine the user's intention to enable the sliding friction function. The value of this execution flag is determined based on the user's specific selection on the in-vehicle central control screen and stored in the vehicle controller. A switch control corresponding to the sliding friction execution function can be pre-displayed on the in-vehicle central control screen. When the user touches this switch control to enable the sliding friction function, the vehicle controller sets the execution flag to 1 and stores it. Similarly, when the user touches this switch control to disable the sliding friction function, the vehicle controller sets the execution flag to 0 and stores it.

[0072] In some optional embodiments, the aforementioned sliding friction flag, engagement point self-learning flag, and execution flag can be uniformly determined using a single switch control displayed on the vehicle's central control screen. Only one general switch control corresponding to the sliding friction function can be pre-displayed on the central control screen. When the user touches this switch control to switch the sliding friction function to the on state, the vehicle controller sets the sliding friction flag, engagement point self-learning flag, and execution flag to 1 and stores this information. Similarly, when the user touches this switch control to switch the sliding friction function to the off state, the vehicle controller sets the sliding friction flag, engagement point self-learning flag, and execution flag to 0 and stores this information.

[0073] As mentioned above, the first, second, and third sub-conditions are in a progressive relationship. Only when the first and second sub-conditions are met simultaneously, and further advanced conditions are met, can the third sub-condition be considered satisfied.

[0074] Specifically, if the current vehicle parameters satisfy the first and second sub-conditions, and further simultaneously satisfy all of the following conditions, then the current vehicle parameters satisfy the third sub-condition:

[0075] The execution flag is set to a preset value, and the current vehicle speed is within a preset speed range.

[0076] It is understandable that the execution flag is a preset value, which can be 1. The execution flag being a preset value indicates that the user has switched the sliding friction execution function to the on state in advance through the touch switch control on the vehicle's central control screen. In other words, the user has the final intention to execute the sliding friction function.

[0077] Furthermore, it is only appropriate to stop engine fuel injection when the vehicle is within the preset speed range, so that the torque converter clutch enters the sliding friction state, i.e. the semi-engaged state, and the vehicle enters the coasting mode, thereby extending the engine fuel cut-off time as much as possible while avoiding vehicle stalling.

[0078] As mentioned above, only when the current vehicle parameters simultaneously meet the first, second, and third sub-conditions can the current vehicle parameters be considered to meet the preset conditions, allowing the clutch in the torque converter to switch to the sliding friction state, i.e., the following steps are executed:

[0079] In step S203, when it is determined that the current vehicle parameters meet the preset conditions, the vehicle controller controls the clutch in the hydraulic torque converter to switch to the sliding friction state.

[0080] It is understood that the engagement and disengagement of the clutch in the torque converter are controlled by a solenoid valve within the clutch. Providing different control currents to the solenoid valve allows it to change the pressure between the two clutch plates. However, due to varying vehicle operating conditions, the control current required to maintain the clutch in the torque converter in a sliding friction state may differ. Therefore, in some optional embodiments, after controlling the clutch in the torque converter to switch to a sliding friction state in step S203, the method further includes:

[0081] In step S204, the vehicle controller determines the control current based on the current vehicle parameters.

[0082] Understandably, current vehicle parameters may also include oil temperature, which refers to the transmission fluid temperature of the torque converter. PID control can be used to determine the real-time pressure required to control the torque converter clutch. Based on the real-time pressure and oil temperature, a pre-stored relationship table is consulted to determine the real-time control current of the torque converter solenoid valve. This relationship table stores the correspondence between pressure, oil temperature, and control current; it was obtained in advance through a limited number of experiments and stored in the vehicle controller.

[0083] In step S205, the vehicle controller controls the solenoid valve in the clutch of the hydraulic torque converter in real time according to the control current, so as to keep the clutch in a sliding friction state.

[0084] It is understandable that whether the engine resumes fuel injection is directly related to whether the clutch is fully disengaged. At higher vehicle speeds and with the clutch engaged, the engine can directly utilize the rotation of the wheels to reverse the flow of fuel. In this situation, the engine can stop fuel injection to reduce fuel consumption. However, once the clutch is fully disengaged, the engine and wheels move relatively independently, and the engine cannot utilize the rotation of the wheels to reverse the flow of fuel. If fuel injection is not resumed at this point, the engine speed will gradually decrease until it stalls. Therefore, when the clutch is fully disengaged, the engine needs to immediately resume fuel injection to avoid stalling. However, the torque converter control method provided in this application incorporates a clutch semi-engagement process. When the vehicle speed decreases to a certain range, the clutch is not immediately disengaged, but rather first enters a sliding friction state (semi-engagement state). When the clutch is in the semi-engagement state, the engine can continue to maintain fuel cut-off, delaying the resumption of fuel injection. During clutch semi-engagement, the rotation of the wheels and sliding friction can be used to reverse the flow of fuel, preventing the engine from stalling due to loss of connection with the wheels. Furthermore, a certain speed difference is maintained between the engine and the wheels, preventing the engine from being dragged and stalled due to low wheel speeds. When the vehicle speed drops to an extreme level, disengage the clutch and resume engine fuel injection.

[0085] The torque converter control method provided in this application controls the clutch in the torque converter to switch to a sliding friction state, i.e., a semi-engaged state, when the current vehicle parameters meet preset conditions, especially when the current vehicle speed is within a preset speed range. The control current of the clutch's solenoid valve is adjusted in real time to maintain the clutch in a semi-engaged state. This control approach effectively utilizes the clutch's semi-engaged function, preventing engine stalling due to low wheel speeds even without fuel injection, and also preventing engine stalling caused by loss of connection between the engine and wheels. In summary, compared to existing technologies that only disengage the torque converter clutch when the vehicle speed drops to a certain level, the torque converter control method provided in this application fully utilizes the clutch's semi-engaged function, maintaining fuel cut-off while preventing engine stalling, extending the fuel cut-off time, and thus further reducing fuel consumption.

[0086] This application also provides a hydraulic torque converter control device, which is installed in the vehicle controller, such as... Figure 3 As shown, the device includes:

[0087] The acquisition module 301 is configured to acquire current vehicle parameters, including the current vehicle speed.

[0088] The judgment module 302 is configured to determine whether the current vehicle parameters meet preset conditions, wherein the preset conditions include the current vehicle speed being within a preset speed range.

[0089] The control module 303 is configured to switch the clutch in the hydraulic torque converter to a sliding friction state when it is determined that the current vehicle parameters meet the preset conditions.

[0090] In some optional embodiments, the preset conditions include a first sub-condition, a second sub-condition, and a third sub-condition. The current vehicle parameters satisfy the preset conditions when all three sub-conditions are met simultaneously. The current vehicle parameters also include a sliding friction indicator, transmission controller status, driving mode, accumulated sliding friction time, and transmission oil temperature. The current vehicle parameters satisfy the first sub-condition when all of the following conditions are met simultaneously:

[0091] The current vehicle speed is within the preset speed range, the sliding friction indicator is at the preset value, the transmission control status is fault-free, the driving mode is not sport mode, the cumulative sliding friction time is less than the preset time, and the transmission oil temperature is within the preset temperature range.

[0092] In some optional embodiments, the current vehicle parameters also include the engagement point self-learning flag, engine speed, engine speed change rate, engine torque, accelerator pedal opening, engine-turbo speed difference, and the current state of the torque converter clutch. If the current vehicle parameters satisfy the first sub-condition and further simultaneously satisfy all of the following conditions, then the current vehicle parameters satisfy the second sub-condition:

[0093] The engagement point self-learning flag is set to a preset value, the engine speed is within a preset speed range, the engine speed change rate is lower than a preset change rate range, the engine torque is within a preset torque range, the accelerator pedal opening is less than a preset opening, the difference between engine and turbine speeds is less than a preset speed difference, and the current state of the clutch is engaged.

[0094] In some optional embodiments, the current vehicle parameters also include an execution flag. If the current vehicle parameters satisfy the first sub-condition and the second sub-condition, and further simultaneously satisfy all of the following conditions, then it indicates that the current vehicle parameters satisfy the third sub-condition:

[0095] The execution flag is set to a preset value, and the current vehicle speed is within a preset speed range.

[0096] In some optional embodiments, the control module 303 is also configured to determine a control current based on current vehicle parameters after switching the clutch in the torque converter to a sliding friction state, and to control the solenoid valve in the clutch of the torque converter in real time based on the control current so as to keep the clutch in a sliding friction state.

[0097] Using the hydraulic torque converter control device provided in this application, when the current vehicle parameters meet the preset conditions, especially when the current vehicle speed is within the preset vehicle speed range, the clutch in the hydraulic torque converter is controlled to switch to the sliding friction state, i.e., the semi-engaged state. At this time, it can avoid the engine stalling due to the low wheel speed, and it can also avoid the engine stalling due to the loss of connection between the engine and the wheels. In short, it can continue to keep the engine fuel cut-off while avoiding engine stalling, and extend the fuel cut-off time, thereby further reducing fuel consumption.

[0098] This embodiment and the method embodiment are based on the same inventive concept and are device embodiments corresponding to the method embodiments. Therefore, those skilled in the art should understand that the description of the method embodiment is also applicable to this embodiment, and some technical details will not be described in detail in this embodiment.

[0099] This application also provides a vehicle that includes the hydraulic torque converter control device provided in the previous embodiment.

[0100] In this application, it should be understood that the terms “first”, “second”, etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated.

[0101] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only.

[0102] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

[0103] The above description is only for the purpose of enabling those skilled in the art to understand the technical solution of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A hydraulic torque converter control method, characterized in that, The method includes: Obtain current vehicle parameters, including current vehicle speed; Determine whether the current vehicle parameters meet preset conditions, wherein the preset conditions include the current vehicle speed being within a preset vehicle speed range; When it is determined that the current vehicle parameters meet the preset conditions, the clutch in the torque converter is controlled to switch to a sliding friction state. When the clutch switches to the sliding friction state, the engine remains fuel-cut off and does not stall. The preset conditions include a first sub-condition, a second sub-condition, and a third sub-condition. When the current vehicle parameters simultaneously satisfy the first sub-condition, the second sub-condition, and the third sub-condition, then the current vehicle parameters satisfy the preset conditions. The current vehicle parameters also include a sliding friction indicator, transmission controller status, driving mode, cumulative sliding friction time, and transmission oil temperature. When all of the following conditions are simultaneously satisfied, it indicates that the current vehicle parameters satisfy the first sub-condition: The current vehicle speed is within the preset speed range, the sliding friction indicator is at a preset value, the transmission control status is fault-free, the driving mode is not sport mode, the cumulative sliding friction time is less than a preset time, and the transmission oil temperature is within a preset temperature range. The current vehicle parameters also include the engagement point self-learning flag, engine speed, engine speed change rate, engine torque, accelerator pedal opening, engine and turbine speed difference, and the current state of the torque converter clutch. When the current vehicle parameters satisfy the first sub-condition, and further simultaneously satisfy all of the following conditions, it indicates that the current vehicle parameters satisfy the second sub-condition: The self-learning identifier of the engagement point is the preset value, the engine speed is within the preset speed range, the engine speed change rate is lower than the preset change rate range, the engine torque is within the preset torque range, the accelerator pedal opening is less than the preset opening, the difference between the engine and turbine speeds is less than the preset speed difference, and the current state of the clutch is the engaged state. The current vehicle parameters also include an execution flag. When the current vehicle parameters satisfy the first sub-condition and the second sub-condition, and further simultaneously satisfy all of the following conditions, it indicates that the current vehicle parameters satisfy the third sub-condition: The execution flag is the preset value, and the current vehicle speed is within the preset speed range.

2. The method according to claim 1, characterized in that, After the clutch in the controlled hydraulic torque converter is switched to a sliding friction state, the method further includes: The control current is determined based on the current vehicle parameters; The solenoid valve in the clutch of the hydraulic torque converter is controlled in real time according to the control current so that the clutch maintains the sliding friction state.

3. A hydraulic torque converter control device, characterized in that, The device includes: The acquisition module is configured to acquire current vehicle parameters, including the current vehicle speed. The judgment module is configured to determine whether the current vehicle parameters meet preset conditions, wherein the preset conditions include the current vehicle speed being within a preset vehicle speed range; The control module is configured to, when it is determined that the current vehicle parameters meet the preset conditions, control the clutch in the torque converter to switch to a sliding friction state, wherein when the clutch switches to the sliding friction state, the engine remains fuel-cut off and does not stall. The preset conditions include a first sub-condition, a second sub-condition, and a third sub-condition. When the current vehicle parameters simultaneously satisfy the first sub-condition, the second sub-condition, and the third sub-condition, then the current vehicle parameters satisfy the preset conditions. The current vehicle parameters also include a sliding friction indicator, transmission controller status, driving mode, cumulative sliding friction time, and transmission oil temperature. When all of the following conditions are simultaneously satisfied, it indicates that the current vehicle parameters satisfy the first sub-condition: The current vehicle speed is within the preset speed range, the sliding friction indicator is at a preset value, the transmission control status is fault-free, the driving mode is not sport mode, the cumulative sliding friction time is less than a preset time, and the transmission oil temperature is within a preset temperature range. The current vehicle parameters also include the engagement point self-learning flag, engine speed, engine speed change rate, engine torque, accelerator pedal opening, engine and turbine speed difference, and the current state of the torque converter clutch. When the current vehicle parameters satisfy the first sub-condition, and further simultaneously satisfy all of the following conditions, it indicates that the current vehicle parameters satisfy the second sub-condition: The self-learning identifier of the engagement point is the preset value, the engine speed is within the preset speed range, the engine speed change rate is lower than the preset change rate range, the engine torque is within the preset torque range, the accelerator pedal opening is less than the preset opening, the difference between the engine and turbine speeds is less than the preset speed difference, and the current state of the clutch is the engaged state. The current vehicle parameters also include an execution flag. When the current vehicle parameters satisfy the first sub-condition and the second sub-condition, and further simultaneously satisfy all of the following conditions, it indicates that the current vehicle parameters satisfy the third sub-condition: The execution flag is the preset value, and the current vehicle speed is within the preset speed range.

4. The apparatus according to claim 3, characterized in that, The control module is also configured to determine a control current based on the current vehicle parameters after the clutch in the control torque converter switches to a sliding friction state, and to control the solenoid valve in the clutch of the torque converter in real time based on the control current, so as to keep the clutch in the sliding friction state.

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