JPH0623037B2 - How to learn the starting point of the clutch - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a learning method of a clutch connection starting point performed by clutch control of an electronically controlled automatic transmission.

(Prior Art) In clutch control of an electronically controlled automatic transmission, conventionally, learning of a clutch starting point is performed to correct a clutch position that occurs when a friction coefficient changes due to thermal deformation or wear of a clutch plate. Has been adopted.

In this learning, when the transmission is in neutral, the clutch is completely disengaged as shown in FIG. 4, and after confirming that the input shaft has stopped, the clutch is gradually connected until the input shaft rotates. The start position of the clutch is detected, and the clutch position at this time is used as the starting point of connection.

(Problems to be Solved by the Invention) However, when the vehicle body weight is increased due to the load in the starting state of the vehicle, the starting point of clutch engagement changes from, for example, P ₁ point to P ₂ point in FIG. I have something to do. Since the clutch control is performed based on the joint start point as described above, if the joint start point is set to P ₂ point, if the vehicle body is light, an acceleration shock will occur when starting, and if it is set to P ₁ point, the vehicle body will be If it is heavy, problems such as delay in starting traveling will occur.

The present invention has been made in view of such a conventional problem, by correcting the learning value of the clutch start position, stable clutch control can be performed despite changes in vehicle weight and wear of the clutch plates, An object of the present invention is to provide a learning method of a clutch starting point that can improve feeling during clutch connection operation.

(Means for Solving the Problems) In order to achieve the above-mentioned object of the present invention, the present invention controls the engagement / disengagement of a clutch by a clutch actuator based on a stroke signal detected by a clutch stroke sensor. In the electronically controlled automatic transmission, the learning value of the clutch connection starting point when the transmission is unloaded and the learning value of the clutch connection starting point when the transmission is loaded are respectively calculated, and both learning values are weighted and averaged according to the clutch connection state. Is performed at the time of learning, and the learning value of the optimum clutch joint starting point is set as the learning value of the clutch joint starting point.

(Operation) In the present invention, the clutch stroke sensor determines the learning start value of the gear start point of the transmission when the transmission is unloaded, and the transmission is loaded, and the input shaft rotates while the clutch is continuously engaged and disengaged. The joint start point to start is calculated as a learning value, and both learning values are weighted and averaged to learn the optimum joint start position even when the initial joint start position changes, and sudden start etc. Prevents shock and keeps the clutch operation feeling good when starting or engaging the clutch.

(Embodiment) FIG. 1 is a diagram illustrating a configuration of an automatic clutch control system. In the figure, 1 is an accelerator pedal, 1a is an accelerator pedal sensor, 2a is an engine rotation sensor, 2b is a flywheel, 4 is a clutch, 4a is a pressure plate, 4b is a clutch disk, 4c is a diaphragm spring, 4d is a release bearing, 4e is a release lever, 4f is a clutch shaft, and 4g is a lever. Further, 5 is a transmission, 6 is a clutch actuator, 6a is a clutch stroke sensor, 8 is a hydraulic power source, 9 is a tank, 10 is a control unit, 11 is a vehicle speed sensor,
12 is an accumulator, 13 is an input shaft, 1
Reference numeral 4 is an input shaft sensor. Furthermore, 71-
Reference numeral 73 is a solenoid valve, B is a power supply, and SW is a power switch linked with an ignition switch.

In FIG. 1, the solenoid valve 71 is driven when the clutch 4 is disengaged, and the solenoid valves 72 and 73 are driven when the clutch 4 is contacted. That is, when the clutch 4 is disengaged, the control unit 10 drives the solenoid valve 71 to supply the pressure fluid from the pressure source 8 to the clutch actuator 6 to move the piston to the first position.
When the clutch 4 is moved to the right side in the figure, the solenoid valves 72 and 73 are driven to cause the pressure fluid in the clutch actuator 6 to flow out, and the piston is moved to the left side in the figure. Move to. The result of the movement is fed back to the control unit 10 through the clutch actuator sensor 6a. Note that the solenoid valves 72 and 73 used for the contact operation constitute a plurality of systems having different control coefficients by providing an orifice in one of the passages (the passage of the solenoid valve 72). Even if the orifices having different diameters are provided, it is not necessary to have two systems. Further, the disconnection operation side may be further provided with a hydraulic system circuit outside the solenoid valve 71 to form a plurality of systems.
The control of the moving speed and the moving amount of the clutch 4 is performed while controlling the duty ratio of these electromagnetic valves 71 to 73. The clutch stroke sensor 6a is
The movement of the piston of the clutch actuator 6 is detected by, for example, a potentiometer and used as a stroke signal.

In such a clutch control device, first, a method of learning the clutch connection starting point when the transmission is unloaded will be described with reference to the flow chart of FIG.

First, after confirming that the gear shift is completed, the gear position is in the neutral position, and the select lever is in the neutral position, and after satisfying each of these conditions, it is checked whether or not the vehicle is in the stopped state, and Yes of In this case, disengage the clutch. Next, it is checked whether the clutch is disengaged. N
In the case of o, the clutch disengagement operation is performed again, and in the case of Yes, the process of is performed. Then, it is determined whether or not the input shaft has stopped rotating, and when it is confirmed that the input shaft has stopped rotating, the clutch is operated at a low speed. Check whether or not the input shaft has stopped rotating by this contact operation, and if it stops rotating, continue contact operation of the clutch again,
If the rotation starts, that point, that is, the starting point of clutch engagement is stored. In this way, the learning of the clutch engagement start point in the neutral state of the gear is performed. This learning value is CU
T: LEARN1. This learning value is updated every time the above learning is performed, but some past values, for example, seven values are stored in the control unit 10 because they are used when performing weighting calculation of the learning value described later. Stored in memory.

Next, with the transmission under load,
A method for learning the clutch engagement start point is shown in FIG. To describe this, first, make sure that the clutch is in the disengaged position, and check whether the transmission gear is in the reverse position, the low position, or the second position. That is, make sure that the gear is in neutral, medium, or low-speed gear other than high-speed gear. Such a state is a state in which the stopped vehicle is about to start forward traveling or start backward traveling, and therefore the accelerator pedal is not yet depressed. Then, when it is confirmed that the gear of the transmission is in the low speed stage, it is checked whether or not the accelerator pedal depression amount is within a preset low speed region. The low speed range indicates an initial state in which the driver depresses the accelerator pedal in order to start traveling, and for example, the depression amount of the accelerator pedal is lower than about 1/8 of the total depression amount. . Then, when the accelerator pedal is in that area, after confirming that the clutch joint point has not been learned, a certain target rotation speed, for example, 500 rp
Set the engine speed to m. This rotation speed is controlled by the control unit 10 at a constant speed by feeding back the output of the engine rotation sensor 2a. The state that the learning is not completed indicates that the accessory power supply of the vehicle is turned off, the old learning value used up to that point is initialized, and then the accessory power supply is turned on for traveling the vehicle. In addition, the state that the vehicle has already been learned is the state in which the vehicle is started and the learning operation described later is performed, and that value is applied to the memory in the control unit 10 to the vehicle. A state in which learning values are stored.

In such a transmission load condition, next, the clutch is gradually engaged, and the input shaft speed at this time is read to check the clutch engagement condition.

During this process, when it is determined that the pulse generated by the input shaft sensor has generated a predetermined number of pulses within 100 msec, the clutch operation is stopped,
The clutch position at this time, that is, the connection start point is read as CUT: LEARN2 at ultra-low speed. Also, at this time, after confirming the rotation of the input shaft for 60 msec, it is checked again whether the predetermined number of pawls continues for 100 msec. The learned value of the point and the learned value of the connection start point when the transmission is loaded can be weighted to obtain the optimum learned value of the following equation. Based on this learned value, the vehicle is started and this value is set to the control unit 10 It will be stored in the internal memory and will be used as the latest learning value until this value is initialized. Although the specific gravity of the weight is set to 7 or 8 here, this can be freely changed at the time of tuning. If the predetermined number of pulses is small in step, the process returns to step.

CUT: LEARN = [(CUT: LEARN1 × 7) + (CUT: LEARN2)] / 8 The learning operation up to this point is performed within an extremely short time and within the accelerator pedal depression amount setting range.

By setting the clutch connection point based on the learning value determined in this way according to changes in vehicle body weight, etc.,
It is possible to start without causing a shock or delay in the start of running. It should be noted that such learning operation is executed when the operation state in the vehicle reaches the state of the beginning of input in the flow charts of FIGS. 2 and 3, but in some cases even if the number of times of execution is thinned out. Good.

(Effects of the Invention) As is apparent from the above description, according to the present invention, it is suitable for each time based on the constant learning value of the two clutch connection points when the transmission is unloaded and when it is loaded. By weighting, it is possible to set the optimum clutch joint point corresponding to the change in the weight of the vehicle and the change in the friction coefficient of the clutch plate, and based on such set value,
The output of the control unit promises a smooth vehicle start without shock. In addition, since the clutch position control can be accurately performed, it is possible to prevent the engine from being blown up at the time of starting, and to obtain an effect that the clutch life can be significantly improved.

[Brief description of drawings]

FIG. 1 is an explanatory view showing the structure of an automatic clutch control system, and FIG.
FIG. 4 is a flow chart showing a learning method of the clutch engagement starting point when the transmission is unloaded, FIG. 3 is a flow chart showing a learning method of the optimum clutch engagement starting point, and FIG. It is explanatory drawing which shows a change. 1 ... Accelerator pedal 4 ... Clutch 5 ... Transmission 6 ... Clutch actuator 8 ... Hydraulic power source 9 ... Tank 10 ... Control unit 13 ... Input shaft 14 ... Input shaft sensor

Claims (1)

[Claims] 1. An electronically controlled automatic transmission in which a clutch actuator controls disengagement / connection of a clutch based on a stroke signal detected by a clutch stroke sensor, and a learning value of a clutch starting point and a transmission load when a transmission is unloaded. The learning value of the clutch engagement start point at each time is obtained, and the weighted averaging process according to the clutch engagement state is performed for these learning values at the time of learning so that this is set as the optimum learning value of the clutch engagement start point. A method for learning the starting point of clutch connection.