CN115370671A - A central clutch driving system and its starting control method - Google Patents

Abstract

The invention discloses a central clutch driving system, comprising: the guide sleeve is sleeved on the input shaft of the transmission in an empty mode; one end of the cylinder body is sleeved on the guide sleeve; the piston is arranged in the cylinder body and can axially move along the guide sleeve; an accommodating cavity is formed between the piston and the cylinder block; a pre-compression spring disposed in the accommodating chamber, one end of the pre-compression spring abutting against one end of the piston, and the other end abutting against the bottom of the cylinder block; one end of the release bearing is fixedly connected with the other end of the piston; an intake port opened on one end of the cylinder block; and the air inlet mechanism is communicated with the air inlet. Through the cooperation of air inlet mechanism with cylinder body and piston, through the pressure of adjusting work intracavity and then control the piston along axial motion, improve the degree of accuracy that the separation indicates to joint or separate. The invention also provides a control method of the central clutch driving system.

Description

A central clutch driving system and its starting control method

technical field

The invention relates to a central clutch drive system and a starting control method thereof, belonging to the field of commercial vehicle transmissions.

Background technique

With the development of the automobile industry, automatic transmissions have gradually replaced manual transmissions and become the mainstream choice, and the clutch drive system is a core component of automatic mechanical transmissions (AMT), which play a pivotal role in the process of vehicle starting and transmission shifting. effect. At present, the clutch drive system includes electro-hydraulic, electro-electric and electro-pneumatic.

The traditional hydraulically driven clutch drive system requires a set of hydraulic systems such as motor pumps and oil tanks. The system is too complicated, the cleanliness control effect is poor, the maintenance cost is high, and the hydraulic control response speed is slow, the efficiency is low, and the clutch pressure control accuracy is low. Poor; electronically controlled electric clutch drive system (motor-driven screw or worm gear mechanism), according to the working characteristics of the clutch, the clutch needs to maintain a certain state, at this time, the motor needs to continue to provide stall torque, which is not conducive to the life of the motor and can The power consumption is relatively high, and the Chinese patent application publication number CN101440846A discloses a mechanical automatic transmission clutch actuator, which requires high machining precision, and has disadvantages such as complicated control and poor stability; adding self-locking function Can bring transmission efficiency extremely low again (generally lower than 40%), heat generation fast temperature rising height etc., application publication number is that the Chinese patents such as CN103453044A, CN104019150A all disclose self-locking device, but, the structure of both self-locking devices They are relatively complex and difficult to assemble.

Most of the existing electropneumatic clutch drive system schemes are similar to the clutch cylinders used in manual transmissions. For example, the Chinese patents with application publication numbers CN112211920A, CN111140608A, etc. all disclose electropneumatic clutch actuators. The pistons all need to drive the release bearing to move through the release fork. Due to the existence of the separation fork (labor-saving lever), although the thrust of the piston can be amplified, the stroke of the piston is increased, resulting in an increase in the axial distance of the cylinder piston, the volume is too large, and the integration of the cylinder piston, separation fork, and separation bearing The lower lead to complex structure of the whole drive system.

Contents of the invention

The present invention designs and develops a central clutch driving system, through which the air intake mechanism cooperates with the cylinder body and the piston, and then controls the axial movement of the piston by adjusting the pressure in the working chamber, so as to improve the accuracy of engagement or separation of the separation fingers.

The present invention also designs and develops a control method for a central clutch drive system, which converts the target torque transmitted by the clutch into the air pressure in the clutch drive system according to the different engagement stages of the clutch during the starting process of the car, and controls the engagement of the clutch through the pressure State, reduce the impact and friction work of starting.

The technical scheme provided by the invention is:

A central clutch drive system comprising:

A guide sleeve, which is vacantly sleeved on the input shaft of the transmission;

a cylinder block, one end of which is sleeved on the guide sleeve;

a piston, which is arranged in the cylinder body and can move axially along the guide sleeve;

An accommodation chamber is formed between the piston and the cylinder block;

a pre-compression spring, which is arranged in the accommodating cavity, one end of the pre-compression spring abuts against one end of the piston, and the other end abuts against the bottom of the cylinder block;

Release bearing, one end of which is fixedly connected with the other end of the piston;

an air inlet, which is opened on one end of the cylinder block;

The air intake mechanism communicates with the air intake.

Preferably, the intake mechanism includes:

The air source of the whole vehicle is connected with the air inlet;

an air pressure sensor, which communicates with the vehicle air source and is close to the air inlet;

an air intake valve, which communicates with the vehicle air source and is arranged between the air intake valve and the vehicle air source;

an exhaust valve, which is communicated between the air pressure sensor and the intake valve;

Wherein, the air pressure sensor, the intake valve, and the exhaust valve are all electrically connected to the automobile TCU.

Preferably, the piston is radially provided with a connection groove towards the side of the guide sleeve.

Preferably, it also includes:

Two guide rings are matched and arranged in the connecting groove.

Preferably, a sealing ring is provided between the inner wall of the cylinder and the piston.

Preferably, a dust-proof sleeve is provided between the outer wall of the cylinder and the piston, and a dust-proof felt is provided between the dust-proof sleeve and the outer wall of the cylinder.

Preferably, a dust cover is provided between the piston and the release bearing.

A starting control method of a central clutch drive system, using the central clutch drive system, comprising:

Step 1. After the vehicle starts, record the position of the initial clutch slipping point;

Step 2. After the transmission is shifted into gear, control the clutch to eliminate the idle travel, so that the clutch is engaged to the slip point and enters the idling stage;

Step 3. Control the pressure of the working chamber to the pressure corresponding to the half-joint point, so that the clutch continues to engage to the half-joint point, and enters the sliding friction stage;

Step 4: Control the clutch to continue to engage. After the clutch is fully engaged, start is completed.

Beneficial effects of the present invention:

The present invention adopts the electro-pneumatic scheme to drive the clutch, and the structural scheme is simpler, more stable, and lower in cost than the hydraulically driven scheme; compared with the electric scheme, the machining accuracy requirement is lower, the energy consumption is low, the service life is long, and the failure rate is low.

The present invention adopts the central electric control pneumatic scheme to drive the clutch, the structure is simpler than the existing separation fork scheme, the axial length is greatly reduced, and the sensor, pressure chamber, piston, release bearing, housing and other components are integrated Being integrated, the integration degree and system efficiency of each component are improved, and the installation convenience of the drive system is also improved.

The invention collects the air pressure signal of the pressure chamber through the air pressure sensor, controls the pressure of the pressure chamber through the electronic control unit, and then controls the displacement of the piston to drive the separation or engagement of the separation finger, which improves the control accuracy when the piston stroke becomes shorter The low problem greatly improves the accuracy of the disengagement finger engagement or disengagement.

The starting control method of a central clutch drive system proposed by the present invention optimizes the self-learning of the kisspoint point; and calculates the target torque transmitted by different clutches according to the different engagement stages of the clutch in the starting process, and converts the target torque For the air pressure in the clutch drive system, the impact and friction work of starting are reduced.

Description of drawings

Fig. 1 is a structural schematic diagram of the central clutch driving system of the present invention.

Fig. 2 is a flow chart of clutch kisspoint self-learning control according to the present invention.

Fig. 3 is a flow chart of starting control of the central clutch driving system of the present invention.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings, so that those skilled in the art can implement it with reference to the description.

As shown in Figures 1-3, the present invention provides a central clutch drive system, including: dust-proof felt 1, first sealing ring 2, dust-proof sleeve 3, cylinder block 4, piston 5, release bearing 6, anti-dust Dust cover 7, guide ring 8, guide sleeve 9, second sealing ring 10, precompression spring 11, air inlet 12, air pressure sensor 13, intake valve 14, exhaust valve 15.

The guide sleeve 9 is sleeved on the input shaft of the transmission, and one end of the cylinder block 4 is sleeved on the guide sleeve, and is fixedly connected with the guide sleeve 9. The piston 5 is arranged in the cylinder body and can be pivoted along the guide sleeve 9. direction movement, an accommodation cavity is formed between the piston 5 and the cylinder block 4, the pre-compression spring 11 is arranged in the accommodation cavity formed by the piston 5 and the cylinder block 4, one end of the release bearing 6 is fixedly connected with the other end of the piston 5, and in the cylinder body On one end of 4, offer air inlet 12, air inlet is connected with air inlet mechanism.

The intake mechanism includes: an air pressure sensor 13, an intake valve 14, an exhaust valve 15 and a vehicle air source. Wherein, the air source of the whole vehicle is connected with the air inlet, the air pressure sensor 13 is connected with the air source of the whole vehicle, near the air inlet 12, and the air intake valve 14 is connected with the air source of the whole vehicle, and is located between the air pressure sensor 13 and the air source of the whole vehicle. Between; the exhaust valve 15 communicates with the vehicle air source, and is located between the air pressure sensor and the exhaust valve 15.

In the present invention, as a preference, the cylinder block 4 and the guide sleeve 9 are connected by welding, a working chamber is formed between the cylinder block 4 and the piston 5, and an air inlet 12 is opened on one side of the cylinder block 4, The high-pressure gas enters the working chamber from the gas supply source through the air inlet 12 to push the piston 5 to move axially. The release bearing is connected with the piston 5 and moves together with the piston 5 during operation.

The pre-compression spring 11 is arranged in the working chamber, which can reset the piston 5. The pre-compression spring 11 can make the release bearing 6 and the clutch diaphragm spring release finger stick together, preventing the loss of parts caused by the collision between the two during work due to gaps.

The air pressure sensor 13 is electrically connected to the transmission controller (TCU), and the TCU is electrically connected to the intake valve 14 and the exhaust valve. The working chamber is connected to the air source of the vehicle through the intake valve 14. Air valve 15 and TCU form a closed-loop control system. The air pressure sensor 13 is used to detect the air pressure information of the working chamber and transmit it to the TCU. After receiving the air pressure information, the TCU controls the opening of the intake valve 14 through the duty cycle (PWM), and the high-pressure gas from the air source of the whole vehicle enters the working chamber. The chamber drives the piston 5 and the release bearing 6 to move, and the release bearing 6 pushes the release finger to drive the clutch to separate.

The vehicle air source, TCU, intake valve 14 and exhaust valve 15 are systems independent of the invention patent of the present application.

The piston 5 is connected with the guide ring 8, the guide ring 8 is arranged in the groove of the piston 5, the guide ring 8 is connected with the guide sleeve 9, there is relative movement between the guide ring 8 and the guide sleeve 9, the clutch drive system is installed , the guide sleeve 9 is sleeved on the input shaft of the transmission.

The central clutch drive system also includes a first sealing ring 1 arranged between the cylinder body 4 and the piston 5 and a second sealing ring 10 arranged between the piston 5 and the guide sleeve 9, which are used to seal the working chamber and prevent gas leaks.

The central clutch drive system also includes a dust cover 7 located between the piston 5 and the release bearing 6, a dust sleeve 3 located between the cylinder block 4 and the piston 5, and a dust sleeve 3 located between the dust sleeve 3 and the cylinder block 4. The dust-proof felt 1 is used to prevent dust from entering the working chamber.

The present invention also provides a control method of a central clutch drive system, including:

Step 1. After the vehicle starts, record the position of the initial clutch slipping point;

Step 2. After the transmission is shifted into gear, control the clutch to eliminate the idle travel, so that the clutch is engaged to the slip point and enters the idling stage;

Step 3. Control the pressure of the working chamber to the pressure corresponding to the half-joint point, so that the clutch continues to engage to the half-joint point, and enters the sliding friction stage;

Step 4: Control the clutch to continue to engage. After the clutch is fully engaged, start is completed.

Specifically include:

(1) Kisspoint self-learning method

After the AMT program is initialized, start the engine, control the intake valve action of the clutch, and set the maximum air pressure _P1 in the working chamber of the corresponding clutch drive system to 100% when the clutch is disengaged to the maximum position.

When the TCU sends the Kisspoint self-learning command, it controls the intake valve action of the clutch, and the clutch is separated until the air pressure = preset KP value + 20% (the initial value of the preset KP = 50%, and then the preset KP = the result of the last self-learning ), then control the action of the exhaust valve of the clutch, slowly engage the clutch, record the air pressure P ₂ in the working chamber of the clutch drive system when the intermediate shaft speed signal is greater than 5rpm, then the Kisspoint value: KP=P ₂ /P ₁ *100%; Record and store the clutch kisspoint value KP.

(2) Start control method

①Step 1: After the AMT control program is initialized, record and store the position of the clutch slipping point (Kisspoint);

②Step 2: After the transmission is in gear, control the clutch to eliminate the idle travel, engage to the Kisspoint position, and enter the idling stage;

When the vehicle starts, when the driver steps on the accelerator pedal, set the target air pressure of the clutch drive system to the air pressure value corresponding to the Kisspoint position, control the exhaust valve of the clutch, and quickly engage the clutch to the Kisspoint position. At this time, the clutch driving disc and The driven disc slips;

Entry conditions: TCU issues a vehicle start command and the transmission is in gear;

Exit condition: The air pressure value in the working chamber of the clutch drive system has reached KP.

③Step 3: Control the clutch to continue to engage to the half-engagement point (the air pressure value in the working chamber of the clutch drive system reaches the air pressure corresponding to the half-engagement point), and enter the speed synchronization stage (slipping friction stage);

Among them, the air pressure of the working chamber × the cross-sectional area of the working chamber = the thrust of the clutch drive system, that is, the force acting on the clutch release finger, and then look up the table according to the specific clutch load characteristics and separation characteristics to obtain the corresponding transmission torque value under the thrust at this time;

The half-engagement point refers to the clutch position corresponding to the torque transmitted by the clutch = the resistance torque of the whole vehicle. After passing this critical value, the speed of the input shaft of the transmission suddenly changes from zero, and the vehicle starts to move.

The torque transmitted by the clutch corresponding to the half joint point is the sum of the following two parts of torque.

In the first part, first set the engine target speed at start, and calculate the deviation between the engine target speed and the actual engine speed. Through the speed deviation PID control, the first target torque of the clutch is obtained, including:

PID control control formula:

In the formula: T _q1 is the first target torque of the clutch, K _p is the proportional gain coefficient, e(t) is the position error of the clutch actuator (the difference between the actual position and the set position), K _i is the integral gain coefficient, and K _d is proportional gain factor;

In the second part, look up the table through the accelerator pedal and the engine speed to obtain the base torque, and then calculate the gain coefficient through the current vehicle weight and current slope to obtain the base torque * gain coefficient, and obtain the second target torque of the clutch; (Note: the The process needs to limit the maximum and minimum torque value and torque change rate according to the accelerator pedal, vehicle weight, slope and other vehicle signals).

Finally, the target air pressure value is obtained from the calculated required clutch transmission torque look-up table. Entry condition: The air pressure value in the working chamber of the clutch drive system has reached KP.

Exit condition: speed synchronization of the master and slave parts of the clutch has been completed.

④ Step 4: After the speed is synchronized, the clutch is controlled to continue to engage;

Entry condition: speed synchronization (slip grinding at start) of the master and slave parts of the clutch has been completed.

Exit condition: The clutch is fully engaged (the air pressure in the working chamber has dropped to the minimum value).

⑤Step 5: After the clutch is fully engaged, the start is complete;

Entry condition: The clutch is fully engaged (the air pressure in the working chamber has dropped to the minimum value).

The method calculates target torques transmitted by different clutches according to different engagement stages of the clutches in the starting process, and converts the target torques into air pressure in the clutch drive system, thereby reducing the impact and friction work of starting.

Although the embodiment of the present invention has been disclosed as above, it is not limited to the use listed in the specification and implementation, it can be applied to various fields suitable for the present invention, and it can be easily understood by those skilled in the art Therefore, the invention is not limited to the specific details and examples shown and described herein without departing from the general concept defined by the claims and their equivalents.

Claims (8)

1. A central clutch drive system, characterized in that it comprises: A guide sleeve, which is vacantly sleeved on the input shaft of the transmission; a cylinder block, one end of which is sleeved on the guide sleeve; a piston, which is arranged in the cylinder body and can move axially along the guide sleeve; An accommodation chamber is formed between the piston and the cylinder block; a pre-compression spring, which is arranged in the accommodating cavity, one end of the pre-compression spring abuts against one end of the piston, and the other end abuts against the bottom of the cylinder block; Release bearing, one end of which is fixedly connected with the other end of the piston; an air inlet, which is opened on one end of the cylinder block; The air intake mechanism communicates with the air intake. 2. The central clutch drive system according to claim 1, wherein the air intake mechanism comprises: The air source of the whole vehicle is connected with the air inlet; an air pressure sensor, which communicates with the vehicle air source and is close to the air inlet; an air intake valve, which communicates with the vehicle air source and is arranged between the air intake valve and the vehicle air source; an exhaust valve, which is communicated between the air pressure sensor and the intake valve; Wherein, the air pressure sensor, the intake valve, and the exhaust valve are all electrically connected to the automobile TCU. 3 . The central clutch driving system according to claim 2 , characterized in that, a connection groove is radially opened on the side of the piston facing the guide sleeve. 4 . 4. The central clutch drive system according to claim 3, further comprising: Two guide rings are matched and arranged in the connecting groove. 5. The central clutch driving system according to claim 4, characterized in that a sealing ring is further arranged between the inner wall of the cylinder and the piston. 6. The central clutch driving system according to claim 5, characterized in that, a dust-proof sleeve is arranged between the outer wall of the cylinder and the piston, and a dust-proof sleeve is arranged between the outer wall of the cylinder and the outer wall of the cylinder. There are dust-proof felts in between. 7. The central clutch drive system according to claim 6, wherein a dust cover is provided between the piston and the release bearing. 8. A starting control method of a central clutch drive system, using the central clutch drive system described in any one of claims 1-7, characterized in that, comprising: Step 1. After the vehicle starts, record the position of the initial clutch slipping point; Step 2. After the transmission is shifted into gear, control the clutch to eliminate the idle travel, so that the clutch is engaged to the slip point and enters the idling stage; Step 3. Control the pressure of the working chamber to the pressure corresponding to the half-joint point, so that the clutch continues to engage to the half-joint point, and enters the sliding friction stage; Step 4: Control the clutch to continue to engage. After the clutch is fully engaged, start is completed.

Images