JPH07122449B2 - Half-clutch position determination method for clutch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a half-clutch position determining method for a clutch of a vehicle having an automatic transmission.

[Conventional technology]

2. Description of the Related Art Conventionally, in a vehicle equipped with an automatic transmission, in order to obtain a reference position of a clutch half clutch of a clutch for turning on / off an engine output and transmitting the output to the transmission, the half clutch is based on a flowchart shown in FIG. The position is determined.

That is, when the control device determines in step S31 that the transmission is in the neutral state and in step S32 that the vehicle speed is "0", it determines whether the clutch is "disengaged" in subsequent step S33. And the clutch is "disengaged"
Otherwise, the clutch is disengaged in step S34, and step S
If the clutch is "disengaged" in 33, the process proceeds to step S35 and waits until the rotation of the input shaft of the transmission is stopped.

When the control device determines in step S35 that the clutch rotational speed is "0", the control device proceeds to step S36 to slowly connect the clutch. If it is determined in step S37 that the input shaft has started to rotate, step
In S38, the clutch position at that time is stored as the half-clutch position, and in the subsequent step S39, the clutch is completely connected to complete the half-clutch position determination process.

Then, based on the learned value of the half-clutch position obtained in step S38, the half-clutch control at the time of starting and shifting is performed so that the clutch is worn and stable half-clutch control can be performed.

[Problems to be solved by the invention]

Now, in order to rotate the input shaft from the stopped state, a torque that overcomes the viscosity of the mission oil is required, and when the viscosity is high, that is, when the oil temperature of the mission oil is low, the torque increases and Is low, that is, when the oil temperature is high, the torque becomes small.

However, since the oil temperature of the mission oil is not taken into consideration in the above-mentioned conventional method of determining the half-clutch position, the viscosity of the mission oil increases at low temperatures and the half-clutch position shifts to the connecting side, and the clutch is engaged when starting or shifting. There is a problem in that the start shock and the shift shock become large because the amount becomes excessive. Also, if the oil temperature of the mission oil becomes high due to the heat when the clutch is hot due to the heavy use of the half clutch, the viscosity of the mission oil will decrease and the clutch plate will be deformed by the heat to learn the half clutch position. There is a problem in that the value shifts to the disconnection side and the clutch engagement amount becomes insufficient at the time of starting and shifting, causing the clutch to slip and the vehicle to slow down.

The present invention has been made to solve the above problems, and its object is to determine the half-clutch position only when the oil temperature of the mission oil is within a predetermined reference range. Variation within the reference range to prevent excessive clutch engagement when the oil temperature of the transmission oil is low, or insufficient clutch engagement when the oil temperature is high, to perform stable half-clutch control and start the vehicle. Another object of the present invention is to provide a half-clutch position determining method for a clutch that can improve the feeling of gear shifting.

Configuration of the Invention [Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention completely removes a clutch for transmitting / outputting an engine output and transmitting the output to a transmission from a completely disengaged state. In the clutch half-clutch position determining method, the clutch is operated in the direction of the connected complete connection, and the clutch half-clutch position at that time is determined based on the state of the input shaft of the transmission based on the operation of the clutch. Measure the mission oil temperature,
The half clutch position determination method for the clutch is such that the half clutch position is determined only when the measured temperature is within the predetermined reference range, and the half clutch position is not determined when the measured temperature is outside the reference range. To do.

[Action]

The half-clutch position is determined only when the vehicle is at a standstill, the transmission is in the neutral position, and the mission oil temperature is within the predetermined reference range. No decision is made.
Therefore, the variation of the half-clutch position is limited to within the reference range, whereby stable half-clutch control is performed,
The feeling of starting and shifting is improved.

〔Example〕

An embodiment in which the present invention is embodied in a forklift will be described below with reference to FIGS.

FIG. 1 shows the mechanism of a forklift drive system and an electric block circuit. The output of the engine 1 is a dry single plate clutch 2.
Is transmitted to the automatic transmission 3 via the differential gear mechanism 4, and the automatic transmission 3 drives the drive wheels 5 for traveling forward and backward at a predetermined gear ratio. The engine 1 is also used as a drive source for a hydraulic pump that supplies hydraulic oil to a lift cylinder for raising and lowering a fork and a tilt cylinder for tilting a mast.

The dry single plate clutch 2 for turning on and off the output of the engine 1 is adjusted in connection with the stroke of the rod 6a which expands and contracts based on the drive of the clutch control actuator 6. On the other hand, the automatic transmission 3 is driven at the first speed (low speed) by driving the shift switching actuator 7.
It is possible to shift to the second speed (high speed) and to switch to forward traveling, neutral (neutral position) and reverse traveling by driving the forward / reverse switching actuator 8.

Next, an electric circuit for driving and controlling the actuators 6 to 8 will be described.

For example, an oil temperature sensor 9 composed of a thermistor is installed at the bottom of the mission case by being embedded or inserted, detects the oil temperature of the mission oil in the automatic transmission 3, and the detection signal is digitally detected by the A / D converter 10. It is converted into a signal and output to the input / output interface 11.

The vehicle speed sensor 12 detects the rotation speed of the output shaft of the automatic transmission 3 and outputs the detection signal to the input / output interface 11
Output to. The rotation speed sensor 13 detects the rotation speed of the input shaft 3a of the automatic transmission 3 and outputs the detection signal to the interface 11. The engine speed sensor 14 detects the speed of the output shaft of the engine 1 and outputs a detection signal to the interface 11.

Stroke detection sensor 15 consists of a potentiometer,
The stroke amount of the rod 6a of the clutch control actuator 6, that is, the clutch connection state is detected, and the detection signal is converted into a digital signal by the A / D converter 16 and output to the interface 11.

The accelerator sensor 17 is composed of a potentiometer, detects the amount of depression of the accelerator pedal 18 provided in the driver's seat,
The detection signal is converted into a digital signal by the A / D converter 19 and output to the interface 11.

The forward / backward detection sensor 20 detects a switching state (forward, neutral, backward) of the forward / backward operating lever 21, which is also provided in the driver's seat, that is, a direction point, and outputs the detection signal to the interface 11.

A central processing unit (hereinafter referred to as CPU) 31 inputs detection signals from the respective sensors via the input / output interface 11 and operates according to a control program stored in a storage device 32.

The CPU 31 is adapted to determine the stroke amount of the rod 6a of the clutch control actuator 6, that is, the connection state of the dry single plate clutch 2 based on the detection signal from the stroke detection sensor 15. Further, the CPU 31 is adapted to determine the depression amount of the accelerator pedal 18 based on the detection signal from the accelerator sensor 17.

It should be noted that each of these indexes is indexed on the basis of the connection and depression amount data for the detection signals of the stroke detection sensor 15 and the accelerator sensor 17, which are stored in the storage device 32 in advance.

Then, the CPU 31 determines the engine rotation speed corresponding to the calculated accelerator pedal depression amount based on the data stored in the storage device 32, and sets the engine rotation speed through the input / output interface 11 and the throttle actuator drive circuit 22 so as to obtain the calculated rotation speed. The number of rotations of 1 is controlled.

Further, the CPU 31 is adapted to judge the operation start of the accelerator pedal 18 based on the detection signal from the accelerator sensor 17, and when it is judged that the pedal 18 is not operated, the clutch 2 is completely disengaged. The clutch control actuator 6 is driven and controlled via the interface 11 and the clutch actuator drive circuit 23 so as to hold the clutch control actuator 6.

Further, the CPU 31 determines the direction point of the forward / backward operating lever 21 at that time based on the detection signal from the forward / backward traveling detection sensor 20, and the forward / backward switching actuator via the interface 11 and the forward / backward actuator drive circuit 24. 8 for driving and controlling the interface 11 based on the detection signal from the accelerator sensor 17.
Also, the shift actuator drive circuit 25 is driven and controlled.

The CPU 31 calculates the vehicle speed of the forklift based on the detection signal from the vehicle speed sensor 12, and the rotation speed sensor 13
The rotation speed of the input shaft 3a is calculated based on the detection signal from the. The CPU 31 indicates that the vehicle speed is “0”, that is, the forklift is in the stopped state,
When the forward / reverse switching actuator 8 is in the neutral (neutral position) state and the clutch 2 is completely disengaged and the input shaft 3a has a rotational speed of "0", the clutch 2 is slowly connected. Direction, the stroke amount of the rod 6a of the clutch control actuator 6 when the input shaft 3a starts to rotate based on the operation of the clutch 2 is determined as the half clutch position.

The half-clutch position decision reference range T ₂ through T ₁ the oil temperature T detected by the oil temperature sensor 9 is predetermined (T _2> T ₁₎
It is performed only when the half-clutch position is outside the reference range, and the half-clutch position is not determined when it is outside the reference range.This limits the shift amount of the half-clutch position to the connected side or the disconnected side within the reference range. It is designed to prevent an excessive amount of clutch engagement when the oil temperature of the mission oil is low, or an insufficient amount of clutch engagement when the oil temperature is high.

Next, the operation of the forklift configured as described above will be described based on the flowchart shown in FIG.

First, when the CPU 31 determines in step S1 that the transmission 3 is in the neutral state, and in step S2 that the vehicle speed is "0", that the vehicle is fast and the forklift is in the stopped state, the process proceeds to step S3.

CPU31 discriminates whether the oil temperature T> reference value T ₂ detected by the oil temperature sensor 9 at step S3, the determination result is T ₂ ≧ T proceeds to step S4. Continued Step S4
At 31, the CPU 31 determines whether or not the oil temperature T <reference value T ₁ , and if the determination result is T ≧ T ₁ , the process proceeds to step S5. In step S5, the CPU 31 determines whether the clutch 2 is "disengaged". If the determination result is that the clutch 2 is engaged, the process proceeds to step S6 to activate the clutch actuator drive circuit 24 to disengage the clutch 2.

Subsequently, the CPU 31 determines the input shaft 3a in step S7.
Wait until the number of rotations of the
When the rotation speed of 3a becomes "0", the process proceeds to step S8, the clutch actuator drive circuit 23 is operated, and the clutch 2 is slowly operated in the connecting direction.

In step S9, the CPU 31 determines whether the rotation speed of the input shaft 3a is "0", and the determination result is not "0", that is, when the input shaft 3a starts to rotate,
Proceeding to step S10, the position of the clutch 2 is determined as the half-clutch position and stored in the storage device 32, and the following step S1
At 1, the clutch is completely engaged and the half clutch position determination process ends.

Then, the CPU 31 performs the half-clutch control at the time of starting and shifting, based on the learned value of the half-clutch position obtained in step S10.

Now, the viscosity of the mission oil increases as the temperature decreases. Therefore, as shown in FIG. 3, in the conventional method, in order to rotate the input shaft 3a, the shift of the half clutch position to the connecting side is up to point A. However, in this embodiment, the half-clutch position of the clutch 2 is determined only when the oil temperature T of the transmission oil is the reference value T ₂ ≧ T ≧ the reference value T ₁ , and the oil temperature T <the reference value. At T ₁ , the half-clutch position of clutch 2 is not determined, so
It is possible to shift the half-clutch position to the connection side up to the point B, which allows the clutch 2 to start and shift.
It is possible to prevent an excessive amount of connection of the clutch and perform stable clutch control, and to obtain a stable starting and shifting feeling even at low temperatures.

Also, the viscosity of the mission oil decreases as the temperature rises, so the oil temperature of the mission oil may be high,
If the oil temperature of the mission oil becomes high due to the heat when the clutch 2 is heated to a high temperature by using a large number of half-clutch, the shift of the half-clutch position to the disengaged side is caused by the conventional method as shown in FIG. Although it was up to the point D where the connection amount becomes insufficient, in this embodiment, the half clutch position of the clutch 2 is not determined when the oil temperature T> the reference value T ₂ , so that the half clutch position is disengaged. The shift to the side can be up to point C, and even if the clutch plate is deformed due to heavy use of the half clutch, it is possible to prevent the insufficient amount of clutch engagement at the time of starting and shifting and to move the vehicle smoothly. It is possible to obtain a good start and shift feeling.

In the above embodiment detects the oil temperature T of the transmission oil, and to detect and store the half-clutch position of the clutch 2 when the detected oil temperature T is in the reference range T ₂ through T ₁ However, after memorizing the half-clutch position of clutch 2,
The oil temperature T of the mission oil is detected, and if the detected oil temperature T is within the reference range T _{2 to} T ₁ , the stored half clutch position is determined as the half clutch position at that time, and the detected oil temperature T is If it is outside the reference range T _{2 to} T ₁ , the stored half-clutch position may be erased.

Further, in the above embodiment, the forklift is embodied, but it may be embodied as a vehicle such as a passenger car or a truck.

Effect of the Invention As described in detail above, according to the present invention, by limiting the range of variation of the half-clutch position, the clutch engagement amount becomes excessive when the oil temperature of the mission oil is low,
Alternatively, when the oil temperature is high, there is an excellent effect that it is possible to prevent shortage of the amount of clutch engagement and perform stable half-clutch control, and to improve the feeling of starting and shifting.

[Brief description of drawings]

FIG. 1 is a forklift mechanism and electric block circuit diagram embodying the present invention, FIG. 2 is a flowchart showing the operation, FIG. 3 is a diagram showing variations in learning values, and FIG. 4 is a conventional half-clutch position determination. 6 is a flowchart showing the operation of the method. In the figure, 1 is an engine, 2 is a dry single plate clutch, 3 is an automatic transmission, and 3a is an input shaft.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Sumi Kitagawa 1015 Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited (72) Inventor, Seiichi Hata, 1015, Kamiodanaka, Nakahara-ku, Kawasaki, Kanagawa Prefecture, Fujitsu Limited (56) References JP-A-61-197824 (JP, A)

Claims (1)

[Claims] 1. A clutch for transmitting and outputting the output of an engine and transmitting the output to a transmission is operated in a direction from a completely disengaged completely connected state to a completely connected completely connected state, and based on the operation of the clutch. In the clutch half-clutch position determination method that determines the clutch half-clutch position at that time based on the state of the input shaft of the transmission, the transmission oil temperature of the transmission is measured, and the measured temperature is within the predetermined reference range. A method for determining a half-clutch position of a clutch, wherein the half-clutch position is determined only when there is a certain time, and the half-clutch position is not determined when it is out of the reference range.