JPH10318288A - Automatic clutch control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automatic clutch control device to perform constantly comfortable Crawling running without depending upon a vehicle load. SOLUTION: A device to effect Crawling running control changes a clutch engaging amount C according to an accelerator operation amount A when an operation amount (an accelerator operation amount) A of an accelerator pedal is below an operation threshold Ath, and performs Crawling running in a so-called half-clutched state. In this case, A clutch stroke (i.e., a clutch engaging amount C) when a vehicle is moved from a stop state is detected as a vehicle load on an engine output, and the more the vehicle load is higher, the more the operation threshold Ath is varied to a high value. This constitution keeps the operation range, where Crawling running control is practicable, of the accelerator pedal approximately at a constant value in spite of a low vehicle load period (an operation range: Aa-Ac) and a high vehicle load period (an operation range: Ab-Ad), and Crawling running in a constantly stable clutch state is realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic clutch control device for automatically engaging and disengaging a clutch when a vehicle starts or stops or a shift is performed.

[0002]

2. Description of the Related Art Conventionally, in an automatic clutch control device of this kind, an operation amount of an accelerator by a driver (hereinafter referred to as an operation amount)
When the accelerator operation amount is small, the clutch is controlled to be in a so-called half-clutch state to realize a low-speed traveling.

FIG. 8 is a graph showing a relationship between an accelerator operation amount A and a clutch engagement amount C, that is, a transmission torque transmitted from an engine to a power transmission device (such as a transmission) by a clutch. is there. As shown in FIG. 8, in this device, when the accelerator operation amount A is smaller than a predetermined operation threshold value Ath, the clutch engagement amount C is changed according to the accelerator operation amount A, and the accelerator operation amount A becomes equal to the operation threshold value. When Ath or more is reached, the clutch is completely engaged.

That is, when the accelerator operation amount A is smaller than the operation threshold value Ath, the transmission torque transmitted from the engine to the power transmission device by the clutch is equal to the accelerator operation amount A.
When the transmission torque is greater than the vehicle load with respect to the driving force of the engine, the input shaft of the power transmission rotates, and the driving force of the engine is transmitted to the wheels via the power transmission to drive the vehicle. Is started. Then, as long as the accelerator operation amount A does not exceed the operation threshold value Ath, the low-speed traveling in the half-clutch state is continued.

[0005]

By the way, the vehicle load changes variously depending on the load of luggage and the like, road surface conditions such as uphill / downhill, and the like. The amount A (and thus the clutch engagement amount C) increases. However, since the accelerator operation amount A at which the half-clutch state is released is determined, as the vehicle load increases, the range in which the accelerator can be operated to travel in the half-clutch state becomes narrower.

For example, as shown in FIG. 8, at a certain time (when the vehicle load is low), the vehicle starts to move when the accelerator operation amount is Aa, and at another time (when the vehicle load is high), the accelerator operation amount becomes Ab. Assuming that the vehicle starts moving at the time of, the range of the accelerator operation amount A in which the vehicle can travel at a low speed in the half-clutch state is in the range of Aa to Ath at a low vehicle load, and A at a high vehicle load.
The range is b to Ath.

As a result, as the vehicle load increases, it becomes more difficult to continue running in the half-clutch state, and there is a problem that the running state at the time of low-speed running becomes unstable and the driving feeling deteriorates. . In other words, if the range in which the accelerator can be operated to travel in the half-clutch state is narrow, the accelerator pedal operation amount A can be immediately increased by simply depressing the accelerator pedal a little further from the operation position where the vehicle has started to move.
Therefore, it is difficult to continue running in the half-clutch state because the vehicle speed exceeds th and the state changes to the normal running state in which the clutch is completely engaged.

The present invention has been made in order to solve the above problems.
It is an object of the present invention to provide an automatic clutch control device capable of always achieving comfortable low-speed running regardless of the vehicle load.

[0009]

In the automatic clutch control device according to the first aspect of the present invention, the operation amount of the accelerator pedal detected by the accelerator operation amount detecting means is predetermined. If it is smaller than the set operation threshold value, the half-clutch travel control means controls the clutch drive means to increase or decrease the amount of engagement of the clutch in accordance with the operation amount of the accelerator pedal, so that the half-clutch operation control means Slow running in the clutch state is realized.

In the present invention, the threshold changing means changes the operation threshold to a larger value as the vehicle load detected by the load detecting means is larger. That is, when the vehicle load is large, the operation amount of the accelerator pedal when the vehicle starts to move increases, but the operation threshold value also increases accordingly. Therefore, the operation of the accelerator pedal that maintains the half-clutch state regardless of the vehicle load. A sufficient range will be secured.

Therefore, according to the automatic clutch control device of the present invention, it is possible to realize stable low-speed running in the half-clutch state regardless of the vehicle load, and to improve the driving feeling during the low-speed running. By the way, the vehicle load is equal to the driving force required to start the vehicle, and this driving force is expressed by the transmission torque transmitted from the engine side to the power transmission device side by the clutch, that is, the engagement amount of the clutch. Can be.

Therefore, the load detecting means is provided, for example, in claim 2
As described in the above, the operation state detection means for detecting the operation state of the input shaft of the power transmission device, the engagement amount detection means for detecting the engagement amount of the clutch, the operation from stop to rotation by the operation state detection means When the change in the state is detected, the engagement amount of the clutch detected by the engagement amount detecting means may be configured to be a vehicle load by a detection control means.

Next, in the automatic clutch control device according to the third aspect, when the vehicle speed detected by the vehicle speed detecting means is equal to or higher than a predetermined allowable speed, the control prohibiting means includes a half-clutch traveling control means. Prohibit the control by. That is,
If the vehicle speed is higher than a certain level, stable running with the clutch completely engaged is possible, and it is not necessary to run with the clutch partially engaged, so this is prohibited.

Therefore, according to the automatic clutch control device of the present invention, the wear of the clutch due to the meaningless half-clutch running can be prevented, and the reliability of the device and the durability of the clutch can be improved.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram illustrating the entire configuration of the automatic clutch control device according to the present embodiment.

The automatic clutch control device according to the present embodiment includes an engine 2, a five-speed transmission 4 capable of mechanically switching gears in response to operation of a shift lever SH, and an output shaft 2a of the engine 2. The present invention is applied to a vehicle having a clutch mechanism 6 including a well-known friction clutch provided between the transmission 4 and an input shaft 4a.

As shown in FIG. 1, the automatic clutch control device of this embodiment includes a clutch actuator 8 for operating the clutch mechanism 6 in accordance with an operation command Sc, and a clutch stroke sensor 10 for detecting a clutch stroke of the clutch mechanism 6. , A rotation sensor 12 for detecting a rotation speed Ne of the output shaft 2a of the engine 2 (hereinafter, referred to as engine rotation speed), and a rotation speed of the input shaft 4a of the transmission 4 (hereinafter, referred to as intermediate shaft rotation speed) Nc. A rotation sensor 14, a vehicle speed sensor 16 for detecting a vehicle speed V from the rotation speed of a driven wheel, and an operation amount of an accelerator pedal AP (hereinafter, referred to as an operation amount)
An accelerator position sensor 18 for detecting A (accelerator operation amount); and detecting which position P (hereinafter referred to as a lever position P) of the shift lever SH among neutral positions other than 1st to 5th speed, reverse, and neither. Lever position sensor 2
0 and a well-known microcomputer,
Various control signals Se based on the vehicle speed V, accelerator operation amount A, engine speed Ne, and the like detected by the above-described sensors.
And an engine ECU 22 for controlling a fuel injection amount, an ignition timing, and the like of the engine 2, and a vehicle speed V, an accelerator operation amount A, An operation command Sc to be input to the clutch actuator 8 is generated based on the lever position P, the clutch stroke (that is, the clutch engagement amount C), the engine speed Ne, the intermediate shaft speed Nc, and the like. An automatic clutch ECU 24 for controlling speed and the like.

FIG. 2 shows the clutch actuator 8
FIG. 3 is a hydraulic circuit diagram illustrating the configuration of FIG. As shown in FIG. 2, the clutch actuator 8 includes a drain tank 30 that stores the clutch oil, a pair of pumps 32 that pumps the clutch oil in the drain tank 30, a motor 34 that drives the pair of pumps 32, A clutch release cylinder (hereinafter simply referred to as a cylinder) 36 operated by pressure oil supplied from the pump 32;
6 and a pressure reducing control valve 40 provided in the hydraulic path from the cylinder 36 to the drain tank 30.

A check valve 4 for preventing a backflow of clutch oil is provided in the hydraulic path on the input side and the output side of each pump 32.
2 are provided, and between the input side of the pressure increasing control valve 38 (hereinafter, referred to as a pressure increasing path) and the output side of the pressure reducing control valve 40 (hereinafter, referred to as a pressure decreasing path). When the oil pressure in the pressure booster rises above a set value, a relief valve for preventing the oil pressure in the pressure booster from rising above the set value by releasing clutch oil in the pressure booster to the drain tank 30 via the pressure reducing path. 44 are provided.

Each of the control valves 38 and 40 is a two-position valve including a communication position for passing the clutch oil and a holding position for blocking the passage of the clutch oil. The operation command Sc from the automatic clutch ECU 24 is provided. The position of the valve is switched in accordance with The cylinder 36
The push rod 36a of the clutch mechanism 6
It is configured to operate a clutch release fork (not shown) operated to release the friction clutch.

In the clutch actuator 8 configured as described above, the motor 34 is driven to operate the pump 32, the control valve 38 for increasing pressure is connected to the communication position, and the control valve 4 for reducing pressure is used.
When 0 is set to the holding position, the clutch oil
When the push rod 36a operates the clutch release fork, the friction clutch of the clutch mechanism 6 operates in the release direction, and conversely, the pressure-increasing control valve 3
When the control valve 8 is set to the holding position and the pressure-reducing control valve 40 is set to the communication position, the clutch oil is returned from the cylinder 36 to the drain tank 30, whereby the friction clutch operates in the engagement direction.

Next, the automatic clutch control executed by the automatic clutch ECU 24 will be described with reference to the flowcharts shown in FIGS. The memory of the microcomputer constituting the automatic clutch ECU 24 stores an operation threshold setting map and a clutch engagement speed setting map described later.

First, FIG. 3 shows a main process executed by the automatic clutch ECU 24. This process is performed when an ignition key (not shown) is operated to turn on the power to the automatic clutch ECU 24 and thereafter until the power is turned off. Is repeatedly executed during When the present process is started, first, in step (hereinafter simply referred to as “S”) 110, the lever position P is read from the lever position sensor 20, and it is determined whether or not the shift lever SH has been operated. If not, the process proceeds to S120 to read the accelerator operation amount A from the accelerator position sensor 18.

In subsequent S130, it is determined whether or not the accelerator operation amount A read in S120 is equal to or less than a preset operation threshold value Ath.
The process proceeds to S140 to read the vehicle speed V from the vehicle speed sensor 16, and then proceeds to S150. In S150, it is determined whether or not the vehicle speed V read in S140 is equal to or less than a preset allowable speed Vth.
The process proceeds to S160 and executes the low-speed traveling control for controlling the clutch to the half-clutch state, followed by terminating the present process.

In step S130, it is determined that the accelerator operation amount A is larger than the operation threshold value Ath, or in step S150.
If it is determined that the vehicle speed V is higher than the permissible speed Vth in step S170, the process proceeds to step S170, where normal traveling control for controlling the clutch to be completely engaged is executed, and then this process ends.

If it is determined in S110 that the shift lever has been operated, the flow shifts to S180, in which a shift control for operating the clutch in accordance with the gear change of the transmission 4 is executed, and then this processing is executed. finish. In the shift control of S180, first, the shift lever SH
When the lever position P changes from any one of the first to fifth speeds and the reverse position to the neutral position, the clutch actuator 8
And outputs an operation command Sc for completely engaging the clutch with the clutch actuator 8 when the lever position P changes to any one of the first to fifth speeds and the reverse position. I do. At this time, the operation speed (hereinafter referred to as clutch engagement speed) CV at which the clutch is engaged is determined by the intermediate shaft speed Nc and the engine speed Nc.
Although it is set based on the rotation ratio Nc / Ne with respect to e and the lever position P of the shift lever SH, it is not related to the gist of the present invention, and therefore, the description thereof is omitted here.

That is, in the main processing, the shift lever S
When H is operated, the shift control is executed, the shift lever is not operated, and the accelerator operation amount A is equal to the operation threshold A.
When the vehicle speed V is equal to or less than th and the vehicle speed V is smaller than the allowable speed Vth, the low-speed traveling control is executed, and otherwise, the normal traveling control is executed.

Next, the low-speed running control executed in S160 will be described with reference to the flowchart shown in FIG. When the process is started, first, in S210, the rotation sensor 1
4, the intermediate shaft rotation speed Nc is read, and in subsequent S220, it is determined whether or not the read intermediate shaft rotation speed Nc is 0, that is, whether or not the vehicle is stopped. If it is determined that the value is 0, the process proceeds to S230, in which a flag FL indicating that the vehicle is stopped is set (FL ← 1), and then the process proceeds to S280.

On the other hand, if it is determined in S220 that the intermediate shaft rotation speed Nc is not 0, that is, that the vehicle is moving, the program proceeds to S220.
The process proceeds to 240, and it is determined whether the flag FL is set. Then, the flag FL is cleared (FL =
0), it is determined that the vehicle has been moving before, and the process directly proceeds to S280. On the other hand, if the flag FL is set (FL = 1), it is determined that the vehicle has started moving from the stopped state and S250 is performed. After the clutch stroke is read from the clutch stroke sensor 10, the operation threshold value Ath is changed based on the read clutch stroke in S260, and the flag FL is cleared (FL ← 0) in S270. The process proceeds to S280.

When the operation threshold value Ath is changed in S250, an operation threshold value setting map stored in the memory in advance is used. This operation threshold setting map is shown in FIG.
As shown in (a), the operation threshold value Ath is set to increase as the clutch stroke at the time of starting the vehicle increases, that is, as the vehicle load increases.

At S280, the target clutch engagement amount is calculated based on the accelerator operation amount A read at S120, and at S290, the clutch stroke calculated at S280 is calculated as the target clutch engagement amount. Is generated, and the operation command Sc is output to the clutch actuator 8 to end the processing.

Next, the normal traveling control executed in S170 will be described with reference to the flowchart shown in FIG. When the present process is started, first, in S310, a clutch stroke is read from the clutch stroke sensor 10, and in S320, it is determined whether or not the clutch is completely engaged based on the read clutch stroke. If the engagement is complete, the process ends.
On the other hand, if it is determined in S320 that the clutch is not completely engaged, the flow shifts to S330, where the rotation sensor 12,
14, the engine speed Ne and the intermediate shaft speed Nc are read.

At S340, a rotation ratio Nc / Ne between the intermediate shaft rotation speed Nc and the engine rotation speed Ne is calculated, and it is determined whether the rotation ratio Nc / Ne is 1, that is, whether the rotation speeds are the same. If the rotation ratio Nc / Ne is not 1, the process proceeds to S350, where the clutch engagement speed CV is set based on the rotation ratio Nc / Ne.
If Ne is 1, the clutch engagement speed CV is set to the maximum speed, and the routine proceeds to S370.

When setting the clutch engagement speed in S350, a clutch engagement speed setting map stored in a memory in advance is used. In this clutch engagement speed setting map, as shown in FIG. 6B, the clutch engagement speed CV is large when the rotation ratio Nc / Ne is small, and the rotation ratio Nc / Ne becomes large (approaching 1). It is set so that it becomes smaller.

Then, in S370, S350 or S3
An operation command Sc is output so that the clutch operates at the clutch engagement speed CV set at 60, and the process ends. That is, in the present process (normal traveling control), immediately after shifting from the low-speed traveling control to the normal traveling control, if the clutch is not yet fully engaged, the clutch is engaged so that the clutch is smoothly engaged. Set the speed,
When the rotation ratio Nc / Ne is small, it is assumed that the clutch is not engaged or the engagement amount is small, the clutch engagement speed is increased, and the rotation ratio Nc / Ne is increased in accordance with the increase in the clutch engagement amount.
When Ne becomes large, the engagement speed is reduced so that the engagement is rapidly advanced and no shock is generated in the vehicle. If the output shaft and the rotation shaft of the engine have the same speed (that is, the rotation ratio Nc / Ne = 1), no shock is generated when the clutch is completely engaged, so that the clutch is independent of the map. The engagement speed CV is set to the maximum speed.

As described above, the automatic clutch control device according to the present embodiment detects the clutch stroke at the time of starting the vehicle as the vehicle load, and controls the low-speed traveling control and the normal traveling control as the vehicle load increases. The operation threshold value Ath serving as a criterion when switching is changed.

For example, as shown in FIG. 6 (a), when the clutch stroke at the start of the vehicle is Ca (when the vehicle load is low), the operation threshold Ath is Ac, and when the clutch stroke at the start of the vehicle is Cb. Assuming that the operation threshold value Ath (when the vehicle load is high) is Ad, as shown in FIG. 7, the operation range of the accelerator pedal capable of performing the low-speed traveling control is Aa to Ac at a low vehicle load and Ab at a high vehicle load. To Ad, which is substantially constant regardless of the vehicle load.

As described above, according to the automatic clutch control device of the present embodiment, the operation range of the accelerator pedal capable of performing the slow-speed running control is sufficiently ensured regardless of the vehicle load.
It is possible to always achieve stable low-speed running, and to improve the driving feeling during low-speed running.

Further, in this embodiment, it is determined not only the accelerator operation amount A but also the vehicle speed V whether to execute the low-speed running control or the normal running control, and the vehicle speed becomes equal to the allowable speed Vth.
When it is larger, the low-speed traveling control is not performed, so that meaningless half-clutch operation is not performed, the wear of the clutch can be prevented, and the reliability of the device can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an entire configuration of an automatic clutch control device according to an embodiment.

FIG. 2 is a hydraulic circuit diagram illustrating a configuration of a clutch actuator.

FIG. 3 is a flowchart illustrating main processing of automatic clutch control.

FIG. 4 is a flowchart showing a low-speed traveling control executed in step 160 of FIG.

FIG. 5 is a flowchart showing normal traveling control executed in step 170 of FIG.

FIG. 6 is an explanatory diagram showing the contents of an operation threshold setting map and a clutch engagement speed setting map.

FIG. 7 is an explanatory diagram illustrating an effect of the present embodiment.

FIG. 8 is an explanatory diagram showing a problem of the conventional device.

[Explanation of symbols]

2 ... Engine 4 ... Transmission 6 ...
Clutch mechanism 8 ... Clutch actuator 10 ... Clutch stroke sensor 12,14 ... Rotation sensor 16 ... Vehicle speed sensor 18 ... Accelerator position sensor 20 ... Lever position sensor 22 ... Engine ECU 24 ... Automatic clutch ECU 30 ... Drain tank 32 ... Pump 34
... Motor 36 ... Clutch release cylinder 36 ... Cylinder 38,40 ... Control valve 42 ... Check valve 44
… Relief valve

Claims (3)

[Claims] 1. A clutch driving means for operating a clutch interposed between an output shaft of an engine and an input shaft of a power transmission device for transmitting power of the output shaft to wheels, and detecting an operation amount of an accelerator pedal. Accelerator operation amount detection means; and if the operation amount detected by the accelerator operation amount detection means is smaller than a predetermined operation threshold, the clutch is configured to increase or decrease the engagement amount of the clutch in accordance with the operation amount. An automatic clutch control device comprising: a half-clutch travel control unit that controls a driving unit; and a load detection unit that detects a load of the vehicle with respect to the driving force of the engine; and a vehicle load detected by the load detection unit is large. An automatic clutch control device, further comprising: threshold changing means for changing the operation threshold to a larger value. 2. The automatic clutch control device according to claim 1, wherein the load detection unit detects an operation state of an input shaft of the power transmission device and an engagement amount of the clutch. An engagement amount detecting unit that detects a change in the operating state from stop to rotation by the operating state detecting unit; and detects an engagement amount of the clutch detected by the engagement amount detecting unit in the vehicle. An automatic clutch control device comprising: a load detection control means; 3. The automatic clutch control device according to claim 1, wherein a vehicle speed detecting means for detecting a speed of a vehicle on which the device is mounted, and a vehicle speed detected by the vehicle speed detecting means is determined in advance. An automatic clutch control device comprising: a control prohibiting unit that prohibits the control by the half-clutch traveling control unit when the speed is equal to or higher than a predetermined allowable speed.