阅读说明：本技术 湿式dct变速器离合器电磁阀洗阀控制方法 (Control method for electromagnetic valve washing valve of clutch of wet DCT (dual clutch transmission) ) 是由 李洪 曾开莲 刘德财 银联作 舒玉春 戴吕俊雅 周勇 陈可 廖海生 陈勇 习建民 于 2021-07-17 设计创作，主要内容包括：本发明公开了湿式DCT变速器离合器电磁阀洗阀控制方法,包括：根据采集到的车辆行驶转速、档位和油门的信息进行计算,根据计算结果进行以下选择：若整车处于高档位稳定行驶工况时,则对处于工作状态的离合器电磁阀进行高油压的周期性洗阀控制,所述整车处于高档位稳定行驶工况需要满足的条件为：车辆行驶档位为奇数或偶数离合器行驶的最大档位,整车不处于换挡过程中,行驶车速大于设定的第一阈值,油门变化率、输出轴转速变化率和发动机转速变化率小于设定值,当前工作离合器处于完全结合状态,刹车位置为完全松开状态,变速器油液温度大于设定值。本发明具有使稳定行驶工况时的湿式DCT变速器离合器电磁阀进行洗阀的优点。(The invention discloses a control method for a wet DCT transmission clutch electromagnetic valve washing valve, which comprises the following steps: calculating according to the collected information of the vehicle running speed, the gear and the accelerator, and selecting the following steps according to the calculation result: if the whole vehicle is in a high-gear stable running working condition, the clutch electromagnetic valve in a working state is subjected to high-oil-pressure periodic washing valve control, and the conditions required to be met when the whole vehicle is in the high-gear stable running working condition are as follows: the running gear of the vehicle is the maximum gear of the odd-numbered or even-numbered clutch, the running speed of the whole vehicle is greater than a set first threshold value when the whole vehicle is not in the gear shifting process, the accelerator change rate, the output shaft rotating speed change rate and the engine rotating speed change rate are less than set values, the current working clutch is in a complete combination state, the brake position is in a complete release state, and the oil temperature of the transmission is greater than the set value. The invention has the advantage that the electromagnetic valve of the wet DCT transmission clutch can be washed when the running condition is stable.)

1. The wet DCT transmission clutch electromagnetic valve washing valve control method is characterized by comprising the following steps:

calculating according to the collected information of the vehicle running speed, the gear and the accelerator, and selecting the following steps according to the calculation result:

if the whole vehicle is in a high-gear stable running working condition, the clutch electromagnetic valve in a working state is subjected to high-oil-pressure periodic washing valve control, and the conditions required to be met when the whole vehicle is in the high-gear stable running working condition are as follows: the running gear of the vehicle is the maximum gear of the odd-numbered or even-numbered clutch, the running speed of the whole vehicle is greater than a set first threshold value when the whole vehicle is not in the gear shifting process, the accelerator change rate, the output shaft rotating speed change rate and the engine rotating speed change rate are less than set values, the current working clutch is in a complete combination state, the brake position is in a complete release state, and the oil temperature of the transmission is greater than the set value;

if the whole vehicle is in a high vehicle speed stable running working condition, pulse type washing valve control of low oil pressure is carried out on a clutch electromagnetic valve in an idle state for a long time, and the condition that the whole vehicle is in the high vehicle speed stable running working condition and needs to be met is as follows: the running gear of the vehicle needs to be larger than 4 gears, the running speed of the whole vehicle is larger than a set second threshold value when the whole vehicle is not in the gear shifting process, the accelerator change rate, the output shaft rotating speed change rate and the engine rotating speed change rate are smaller than set values, the current idle clutch is in a separation state, and the brake position is in a completely-released state.

2. The method of claim 1, wherein after the operating clutch completes a high oil pressure periodic purge control operation, a predetermined time period is waited to allow a next purge control operation.

3. The wet DCT transmission clutch solenoid valve wash valve control method as recited in claim 1, wherein the conditions to be satisfied that the currently operating clutch is in a fully engaged state are: the clutch combination oil pressure in the current working state is more than 4bar, and the input end and the output end of the working clutch have no rotating speed difference.

4. The method of claim 1, wherein the periodic high oil pressure wash control of the clutch solenoid in an active state comprises:

(a1) clearing 0 out a working clutch flushing cycle counter;

(a2) requesting the working clutch control pressure to rise to the maximum allowable clutch pressure according to a set slope from the current target pressure;

(a3) outputting the control pressure value of the working clutch to maintain the maximum allowable pressure for a time T₁ ；

(a4) Requesting the operating clutch control pressure to drop to 120% of the target pressure at a set slope;

(a5) the control pressure value of the output working clutch is 120% of the target pressure and lasts for a time T₂；

(a6) Repeating the steps (a 2) - (a 5) for one cycle;

(a7) the operating clutch control pressure is requested to drop to the target pressure at a set ramp rate.

5. The wet DCT transmission clutch solenoid valve wash valve control method as claimed in claim 4, wherein the target pressure is a required engagement pressure obtained by linear interpolation according to a required clutch engagement torque, the maximum allowable clutch pressure is an oil pressure value corresponding to the maximum allowable clutch torque, and the control pressure is a final pressure request value output after the target pressure is closed-loop regulated.

6. The wet DCT transmission clutch solenoid valve wash valve control method as recited in claim 1, wherein the condition to be satisfied that the currently idle clutch is in a disengaged state is: the pressure requested by the clutch in the current separation state is 0bar, the feedback current of the electromagnetic valve of the idle clutch is 0mA, and the pressure acquired by the sensor of the idle clutch is less than 0.01 bar.

7. The wet DCT transmission clutch solenoid valve wash valve control method as recited in claim 1, wherein for a clutch solenoid valve in an idle state, the clutch is in a disengaged state for a time exceeding a set time for a functional trigger of the wash valve.

8. The method of claim 1, wherein the pulsed low oil pressure wash control of the clutch solenoid in an idle state comprises:

(b1) requesting the pre-engaged gear on the corresponding shaft of the idle clutch to return to the idle state;

(b2) when the corresponding on-shaft gear is returned to the null position, the control pressure of the idle clutch is requested to be 0bar, and the time T is maintained₃；

(b3) When the pressure collected by the idle clutch is less than or equal to 1bar, the control pressure of the idle clutch is set to be 8 bar;

(b4) when the collected pressure of the idle clutch is larger than or equal to the pressure of the half-joint point of the clutch or the maximum maintaining time T₄Then, an idle clutch control pressure of 0bar is requested;

(b5) repeating the above steps (b 2) - (b 4) for three cycles;

(b6) and closing the pre-gear-engaging return-to-empty request on the corresponding shaft of the idle clutch.

9. The wet-type DCT transmission clutch solenoid valve wash valve control method of claim 8, wherein the pre-engaged gear on the shaft is a gear that an idle clutch is engaged in advance with a shift fork on the shaft;

the collected pressure is an actual pressure value collected by a pressure sensor;

the half-joint pressure is an oil pressure value required to be combined when the clutch starts to transmit torque.

10. The wet DCT transmission clutch solenoid valve wash valve control method as recited in claim 1, wherein said travel vehicle speed is greater than a first set threshold value, which is 80km/h, and said travel vehicle speed is greater than a second set threshold value, which is 45 km/h.

Technical Field

The invention relates to a wet dual-clutch transmission, in particular to a control method for a solenoid valve washing valve of a wet DCT (dual clutch transmission).

Background

The wet DCT is a double-clutch transmission which cools a clutch through oil, a piston is driven by a hydraulic system to shift a fork to engage and combine and separate the clutch in the running process of a vehicle, and the two clutches are alternately combined to realize the uninterrupted transmission of power. Transmission Control Unit (TCU) realizes controlling hydraulic pressure oil circuit and then realizing the combination separation of clutch through the drive solenoid valve, but the solenoid valve receives the influence of oil cleanliness easily in the use, if the oil cleanliness difference can lead to the deposit of the inside impurity of solenoid valve to influence the stability of oil pressure control, arouses the solenoid valve jamming when serious. When the whole vehicle runs, particularly in the gear switching process, unsmooth output feeling can be caused in the clamping stagnation of the electromagnetic valve, and even the vehicle cannot run normally.

In order to reduce the risk of clutch solenoid valve jamming, a common method is to wash the clutch solenoid valve in an idle state, and the valve washing method is generally fixed-frequency pulse type washing, or to wash the valve by controlling the oil pressure of the solenoid valve from the minimum to the maximum in a vehicle static state. At present, the existing valve washing mode is mainly used for valve washing of clutches which do not work for a long time or valve washing control during parking, the valve washing mode is a single valve washing mode in a high-frequency square wave pulse mode, and the clutches which are in a working state for a long time cannot be subjected to valve washing.

Disclosure of Invention

The invention provides a method for controlling a solenoid valve washing valve of a clutch of a wet DCT (dual clutch transmission) under a stable running working condition.

The technical scheme for realizing the purpose is as follows:

the control method for the electromagnetic valve washing valve of the wet DCT transmission clutch comprises the following steps:

calculating according to the collected information of the vehicle running speed, the gear and the accelerator, and selecting the following steps according to the calculation result:

if the whole vehicle is in a high-gear stable running working condition, the clutch electromagnetic valve in a working state is subjected to high-oil-pressure periodic washing valve control, and the conditions required to be met when the whole vehicle is in the high-gear stable running working condition are as follows: the running gear of the vehicle is the maximum gear of the odd-numbered or even-numbered clutch, the running speed of the whole vehicle is greater than a set first threshold value when the whole vehicle is not in the gear shifting process, the accelerator change rate, the output shaft rotating speed change rate and the engine rotating speed change rate are less than set values, the current working clutch is in a complete combination state, the brake position is in a complete release state, and the oil temperature of the transmission is greater than the set value;

if the whole vehicle is in a high vehicle speed stable running working condition, pulse type washing valve control of low oil pressure is carried out on a clutch electromagnetic valve in an idle state for a long time, and the condition that the whole vehicle is in the high vehicle speed stable running working condition and needs to be met is as follows: the running gear of the vehicle needs to be larger than 4 gears, the running speed of the whole vehicle is larger than a set second threshold value when the whole vehicle is not in the gear shifting process, the accelerator change rate, the output shaft rotating speed change rate and the engine rotating speed change rate are smaller than set values, the current idle clutch is in a separation state, and the brake position is in a completely-released state.

The above scheme is adopted, wherein

The invention relates to a high-pressure washing valve control method of a clutch electromagnetic valve in a working state, which aims at controlling the high-pressure washing valve of the clutch electromagnetic valve in the working state, improves the oil flow leaked in a gap between a valve body and a valve core of the electromagnetic valve by increasing the pressure, further washes out impurities in the gap between the valve body and the valve core of the valve body through large flow, and effectively cleans the impurities of the clutch electromagnetic valve in the working state on the premise of not influencing the running performance of a whole vehicle.

2, the invention controls the pulse washing valve of the electromagnetic valve of the clutch in an idle state, monitors the size of the oil pressure of the clutch combination in the valve washing process to realize the pulse control of the pressure required by the valve washing, not only ensures the cleaning effect of the oil liquid in the pulse valve washing process, but also prevents the abnormal abrasion caused by excessive clutch combination, and empties the gear on the idle shaft in front of the valve washing to prevent the unexpected clutch combination, thereby effectively ensuring the driving safety in the valve washing process.

The invention has the following advantages:

the invention realizes the cleaning effect on all clutch electromagnetic valves in the running process of the vehicle, can reduce the deposition of impurities in the running process, and improves the cleanliness of the electromagnetic valves, thereby preventing and reducing the probability of electromagnetic valve clamping failure and further prolonging the service life of the transmission.

Drawings

FIG. 1 is a general flow diagram of a clutch solenoid valve wash valve in the practice of the present invention;

FIG. 2 is a detailed flow chart of the clutch solenoid valve purge control in operation during the practice of the present invention;

FIG. 3 is a detailed flow chart of the clutch solenoid valve purge control in an idle state during the practice of the present invention;

FIG. 4 is a pressure control schematic of the clutch solenoid valve wash valve in operation during practice of the invention.

Detailed Description

The present invention will be described with reference to fig. 1 to 4.

The invention discloses a control method for a wet DCT transmission clutch electromagnetic valve washing valve, which comprises the following steps:

calculating according to the collected information of the vehicle running speed, the gear and the accelerator, and selecting the following steps according to the calculation result: the first method is as follows: and if the whole vehicle is in a high-level stable running working condition, performing high-oil-pressure periodic washing valve control on the clutch electromagnetic valve in a working state. The second method comprises the following steps: and if the whole vehicle is in a high-speed stable running working condition, performing low-oil-pressure pulse type washing valve control on the clutch electromagnetic valve which is in an idle state for a long time. For the two valve washing modes, the two valve washing modes are selected according to specific working conditions.

The first embodiment will be explained below:

the conditions required to be met when the whole vehicle is in a high-gear stable running working condition are as follows: the running gear of the vehicle is the maximum gear of the odd-numbered or even-numbered clutch, the running speed of the whole vehicle is greater than a set first threshold value when the whole vehicle is not in the gear shifting process, the accelerator change rate, the output shaft rotating speed change rate and the engine rotating speed change rate are less than set values, the current working clutch is in a complete combination state, the brake position is in a complete release state, and the oil temperature of the transmission is greater than the set value.

After the working clutch completes the periodic high oil pressure valve control action, the next valve control is allowed to start after waiting for a preset time period. The conditions to be met when the current working clutch is in a complete combination state are as follows: the clutch combination oil pressure in the current working state is more than 4bar, and the input end and the output end of the working clutch have no rotating speed difference.

The periodic washing valve control for high oil pressure of the clutch electromagnetic valve in the working state comprises the following steps:

(a1) clearing 0 out a working clutch flushing cycle counter;

(a2) requesting the working clutch control pressure to rise to the maximum allowable clutch pressure according to a set slope from the current target pressure;

(a3) outputting the control pressure value of the working clutch to maintain the maximum allowable pressure for a time T₁ ，T₁0.1-1 second;

(a4) requesting the operating clutch control pressure to drop to 120% of the target pressure at a set slope;

(a5) the control pressure value of the output working clutch is 120% of the target pressure and lasts for a time T₂，T₂0.1-1 second;

(a6) repeating the steps (a 2) - (a 5) for one cycle;

(a7) the operating clutch control pressure is requested to drop to the target pressure at a set ramp rate.

The target pressure is the pressure required to be combined, which is obtained by linear interpolation according to the torque required by the clutch combination, the maximum allowable pressure of the clutch is the oil pressure value corresponding to the maximum allowable torque of the clutch, and the control pressure is the final pressure request value output after the target pressure is subjected to closed-loop regulation.

The following describes the first embodiment with reference to specific data:

1, the conditions that the whole vehicle needs to meet when being in a high-gear stable running working condition are preferably as follows: the driving gear is, for example, an even number highest gear 6 or an odd number highest gear 7, the driving gear is not in the gear shifting process and has no gear change requirement, the vehicle speed is greater than 80km/h, the throttle opening change rate in 2 calculation periods is less than 3%, the output shaft rotating speed change rate is less than 5rpm, the engine rotating speed change rate is less than 15rp, the brake is in a release state, the clutch combination oil pressure in a working state is greater than 4bar, the difference between the engine rotating speed and the working clutch shaft rotating speed is less than 20rpm, and the gearbox oil temperature is greater than 20 ℃. And the clutch electromagnetic valve washing valve is controlled after the clutch electromagnetic valve washing valve meets the conditions and the time of finishing the clutch valve washing operation of the previous work exceeds 10 minutes.

2. If the above condition is satisfied, the periodic wash valve control for high oil pressure to the clutch solenoid valve in the operating state includes the steps of:

(a1) clearing 0 out a working clutch flushing cycle counter;

(a2) requesting the working clutch control pressure to rise to the maximum allowable clutch pressure according to a set slope from the current target pressure;

(a3) outputting a control pressure value of the working clutch to maintain the maximum allowable pressure for 0.2 second;

(a4) requesting the operating clutch control pressure to drop to 120% of the target pressure at a set slope;

(a5) outputting a working clutch control pressure value which is 120% of the target pressure and lasts for 0.2 second;

(a6) repeating the steps (a 2) - (a 5) for one cycle;

(a7) the operating clutch control pressure is requested to drop to the target pressure at a set ramp rate.

3. When the valve washing triggering condition is not met in the working clutch valve washing process, the system judges that the valve washing is interrupted, or the valve washing is completed after the working clutch electromagnetic valve washing cycle is completed for 2 cycles, the system can push out the working clutch valve washing control after any condition is met, and the control pressure is recovered to the normal target pressure value with a larger slope.

Mode two will be explained below:

the conditions that the whole vehicle needs to meet when in a high-speed stable running working condition are as follows: the running gear of the vehicle needs to be larger than 4 gears, the running speed of the whole vehicle is larger than a set second threshold value when the whole vehicle is not in the gear shifting process, the accelerator change rate, the output shaft rotating speed change rate and the engine rotating speed change rate are smaller than set values, the current idle clutch is in a separation state, and the brake position is in a completely-released state.

The conditions to be met when the current idle clutch is in the separation state are as follows: the pressure requested by the clutch in the current separation state is 0bar, the feedback current of the electromagnetic valve of the idle clutch is 0mA, and the pressure acquired by the sensor of the idle clutch is less than 0.01 bar.

For the clutch electromagnetic valve in the idle state, the duration of the clutch in the separation state exceeds the set time of the function trigger of the washing valve.

The pulse type washing valve control for low oil pressure of the clutch electromagnetic valve in the idle state comprises the following steps:

(b1) requesting the pre-engaged gear on the corresponding shaft of the idle clutch to return to the idle state;

(b2) when the corresponding on-shaft gear is returned to the null position, the control pressure of the idle clutch is requested to be 0bar, and the time T is maintained₃，T₃0.1-1 second;

(b3) when the pressure collected by the idle clutch is less than or equal to 1bar, the control pressure of the idle clutch is set to be 8 bar;

(b4) when the collected pressure of the idle clutch is larger than or equal to the pressure of the half-joint point of the clutch or the maximum maintaining time T₄Then, pleaseDetermining idle clutch control pressure 0bar, T₄0.1-1 second;

(b5) repeating the above steps (b 2) - (b 4) for three cycles;

(b6) and closing the pre-gear-engaging return-to-empty request on the corresponding shaft of the idle clutch.

The pre-engaged gear on the shaft is a gear on which a shifting fork on the shaft corresponding to the idle clutch is engaged in advance; the collected pressure is an actual pressure value collected by a pressure sensor; the half-joint pressure is an oil pressure value required to be combined when the clutch starts to transmit torque.

The following describes the second embodiment with reference to specific data:

1. whether pulse type washing valve control of low oil pressure is needed to be carried out on the clutch solenoid valve in an idle state is determined by judging the following conditions: the vehicle running gear is more than or equal to 4 gears, the vehicle is not in the gear shifting process and has no gear change requirement, the vehicle speed is more than 40km/h, the throttle opening change rate in 2 calculation periods is less than 3%, the output shaft rotating speed change rate is less than 5rpm, the engine rotating speed change rate is less than 15rpm, the brake is in a release state, the idle clutch acquisition pressure is less than 0.01bar, the idle clutch request pressure is 0bar, the idle clutch feedback current is 0mA, and the time from the last idle clutch valve washing action end exceeds 6 minutes.

2. If the above conditions are met, the system enters a washing valve control process of the working clutch, and the method specifically comprises the following steps:

(b1) requesting the idle clutch to return to the empty state of the gear on the corresponding shaft;

(b2) when the corresponding shaft gear is returned to the empty state, the control pressure of the idle clutch is requested to be 0bar, and the maintaining time is 0.2 seconds;

(b3) when the pressure collected by the idle clutch is less than or equal to 1bar, the control pressure of the idle clutch is set to be 8 bar;

(b4) when the acquisition pressure of the idle clutch is more than or equal to the half-combination point pressure or the maximum maintaining time is 0.5 seconds, requesting the idle clutch to control the pressure to be 0 bar;

(b5) repeating the above steps (b 2) - (b 4) for three cycles;

(b6) and closing the pre-gear-engaging return-to-empty request on the corresponding shaft of the idle clutch.

3. When the idle clutch valve washing process is not satisfied with the valve washing triggering condition, the system judges that the valve washing is interrupted, or the idle clutch electromagnetic valve washing cycle is completed by 4 cycles, the valve washing is completed, the system pushes out the idle clutch valve washing control after any condition is met, and when the idle clutch valve washing control is pushed out, the system sets the control pressure of the idle clutch to be 0bar so that the idle clutch is completely separated.

4. After the idle clutch electromagnetic valve is withdrawn from the washing valve control, the pre-engaging gear return-to-air request is closed, and the system performs pre-engaging action on the idle shaft according to the gear change requirement.

Finally, it should be noted that: the above embodiments are only preferred embodiments of the present invention to illustrate the technical solutions of the present invention, but not to limit the technical solutions, and the patent scope of the present invention is not limited; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention; in addition, the technical scheme of the invention is directly or indirectly applied to other related technical fields, and the technical scheme is included in the patent protection scope of the invention.