JP2004270810A - Apparatus for controlling clutch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for controlling a clutch, which apparatus carries out automatic engagement control without being affected by fluctuation of the rotational speed of the clutch caused by a torsional vibration, etc. <P>SOLUTION: The apparatus for controlling the clutch has a filter for cutting-off high frequency components in the signal of the rotational frequency of the clutch (NCL) sent from a clutch rotational frequency sensor. Conditions for automatic engagement of the clutch in coasting are as follows. When an accelerator signal by an accelerator opening sensor is OFF and the filtered rotational frequency (fNCL) processed by signal processing in the clutch disengaged from an engine is larger than a clutch engaging and disengaging rotational frequency (N1), the clutch is engaged. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a clutch control device, and is particularly suitable for a mechanical automatic transmission.
[0002]
[Prior art]
In large vehicles such as buses and trucks, the amount of transmission of drive torque is large.Therefore, by combining a mechanical transmission with the same structure as a manual transmission with a clutch device that can automatically connect and disconnect clutches, It is used as an automatic transmission (hereinafter abbreviated as AMT). With such a configuration, it is possible to automatically control the connection and disconnection of the clutch in accordance with the timing of the shift, and to perform the shift automatically.
[0003]
In the automatic clutch device used for the AMT, the engine rotational speed and the clutch rotational speed do not match at the time of the clutch engagement operation. Therefore, a sudden connection may cause a connection shock. The connection speed of the clutch is changed according to the rotation speed to reduce the connection shock (see Patent Document 1). There is also a control method in which the clutch meat is moved while the clutch is being moderately slipped in order to improve the feeling of the clutch meat at the time of connecting the clutch and obtain a feeling of acceleration without rattling (see Patent Document 2).
[0004]
In the automatic clutch device described above, in order to avoid engine stop (hereinafter abbreviated as engine stall) when the vehicle is stopped or when the vehicle speed is reduced to a predetermined speed or less, not only is the clutch engaged or disengaged at the time of gear shifting. It is necessary to automatically disengage the clutch. Conversely, even in the clutch disengaged state, in the case of coasting operation in which the vehicle speed is equal to or higher than a predetermined vehicle speed, it is necessary to automatically bring the clutch into the engaged state in order to secure engine braking. is there. That is, the automatic clutch device has not only the clutch connection / disconnection function at the time of shifting, but also the following clutch connection / disconnection function.
(1) When the vehicle is stopped or when the vehicle speed decreases and the clutch rotation speed becomes equal to or lower than the idle rotation speed of the engine, the clutch is disengaged.
(2) When coasting, for example, when the brake is released and the vehicle speed gradually increases when the vehicle is stopped on a downhill road, the clutch is brought into the engaged state when the clutch speed becomes equal to or higher than the engine idle speed with the vehicle speed.
[0005]
[Patent Document 1]
JP-A-10-274260 (page 3-6, FIG. 1-6)
[Patent Document 2]
JP-A-11-78616 (pages 3-10, FIG. 1-7)
[0006]
[Problems to be solved by the invention]
Not only in AMT, but also in MT (manual transmission), at the time of clutch disengagement connection, torsional vibration occurs in vehicle speed and clutch rotation speed due to a spring element of a drive system component. Specifically, since the shaft or the like acts as a torsion spring, torsional vibration is generated when the clutch is disengaged, and the vehicle speed and the clutch rotational speed temporarily fluctuate due to the torsional vibration (see FIG. 3A described later). ). It is considered that the above-mentioned torsional vibration is also generated when the clutch is disengaged during a shift during traveling.However, when the clutch is disengaged at a high vehicle speed, the torsional vibration is applied because the clutch rotation speed is sufficiently high. The effect is small. However, when the clutch is disengaged in a state where the vehicle speed is low, such as during deceleration, the effect of the torsional frequency on the clutch rotational speed becomes greater.
[0007]
In particular, in the AMT, the clutch connection / disconnection control is automatically performed according to the condition of the vehicle (vehicle speed, engine speed, clutch speed, accelerator opening, etc.). Therefore, prevention and countermeasures of the torsional vibration are required. For example, if a large torsional vibration occurs after the clutch is automatically disengaged by the function (1), the clutch rotational speed may temporarily become higher than the idle rotational speed of the engine ( (See point A in FIG. 3A). This situation corresponds to the condition in which the function (2) works, and there is a problem that the clutch is supposed to be in the engaged state where the clutch should be kept in the disconnected state, and the engine stalls. In other words, despite the fact that the clutch speed is not sufficiently high, the engine and the clutch are brought into the connected state due to temporary fluctuations in the clutch speed, so that the minimum engine speed cannot be maintained. As a result, the engine stall occurred.
[0008]
SUMMARY OF THE INVENTION The present invention has been made in consideration of the above problems, and has as its object to provide a clutch control device that performs automatic connection / disconnection control that is not affected by fluctuations in clutch rotational speed caused by torsional vibration or the like.
[0009]
[Means for Solving the Problems]
A clutch control device according to a first aspect of the present invention solves the above-mentioned problems. A clutch connecting / disconnecting unit for connecting / disconnecting a clutch between an engine and a transmission of a vehicle, and a clutch rotational speed detecting unit detecting a rotational speed of the clutch. Means, an accelerator opening detecting means for detecting an amount of depression of an accelerator pedal, and a filter for cutting a high frequency component of a clutch speed signal from the clutch speed detecting means. Clutch control means for automatically connecting and disconnecting the clutch using the clutch connecting / disconnecting means, when the rotational speed of the clutch in a connected state with the engine is lower than a predetermined rotational speed, puts the clutch in a disconnected state, and the accelerator opening detecting means When the accelerator signal is off and the rotational speed signal-processed by the filter of the clutch disconnected from the engine is greater than a predetermined rotational speed, the clutch is engaged.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
The present invention eliminates the effect of torsional vibration generated when the clutch is disengaged when the clutch connection / disconnection control is automatically performed at a low vehicle speed, particularly in an automatic clutch device used for an AMT (mechanical automatic transmission). For this purpose, a characteristic is that a signal from a sensor for detecting the rotational speed of the clutch (clutch rotational speed detecting means) is filtered by a filter for cutting high-frequency components, and the subsequent signal is used as the clutch rotational speed. Even if there is disturbance such as torsional vibration, by applying a filter, the fluctuation of the clutch rotational speed used as an input signal is reduced, and it is possible to eliminate the influence on the clutch connection / disconnection control. Therefore, by using the signal after the filtering process as the clutch rotation speed, even if the predetermined clutch rotation speed (for example, the engine idle rotation speed) of the clutch disengagement condition is used as the clutch connection condition, incorrect connection of the clutch can be achieved. Can be prevented. Further, when coasting (for example, when the brake is released when the downhill road is stopped and the vehicle speed gradually increases), the clutch can be brought into the engaged state at the predetermined rotation speed. An example of an embodiment of a clutch control device according to the present invention that achieves such effects will be described in detail with reference to the drawings shown below.
[0011]
FIG. 1 is a schematic configuration diagram of an engine, a clutch device, and a transmission in which a clutch control device according to the present invention is used.
[0012]
As shown in FIG. 1, a clutch control device according to the present invention controls a clutch device 3 that connects an output shaft from an engine 1 to a transmission 2.
[0013]
Since the configuration of the engine 1 itself is not directly related to the present invention, the relevant portions will be briefly described, but a generally used engine may be used. The output of the engine 1 is controlled by controlling various attached devices and the like provided in the engine 1, and an output shaft of the engine 1 is provided with an engine speed sensor 4 for detecting the speed of the engine. I have. Ancillary equipment, the engine speed sensor 4, and the like are connected to the engine ECU 5, and the output of the engine 1 is controlled based on input signals from other sensors and control information from other ECUs.
[0014]
Since the configuration of the transmission 2 itself is not directly related to the present invention, the relevant parts will be briefly described. The transmission 2 is an automatic transmission having a plurality of forward gears in addition to the reverse gear. A gear shift unit (hereinafter, abbreviated as GSU) 6 for selecting a shift speed inside the transmission is provided above the transmission 2, and the GSU 6 includes a plurality of electromagnetic valves and a power cylinder (both shown in the figure). ), And is driven by high-pressure operating air supplied from an air tank 8 via an air passage 9.
[0015]
Specifically, a power cylinder is operated by high-pressure operating air supplied in accordance with the operation state of the solenoid valve, and is engaged with the power cylinder to select a gear at a shift speed. ) Is operated to shift gears. A gear position sensor 10 for detecting a gear position is provided in the vicinity of or within the GSU 6, and a transmission ECU 11 determines a signal from the gear position sensor 10 and outputs a control signal to the actuator unit 7. . Further, a clutch speed sensor 12 serving as clutch speed detecting means for detecting an input shaft of the transmission 2, that is, a clutch speed, and a vehicle speed sensor 13 for detecting a vehicle speed based on the speed of the output shaft of the transmission 2 are also provided. It is provided to the transmission ECU 11 and is controlled by the transmission ECU 11 so that these rotation speeds are synchronized at the time of shifting. Also, the transmission ECU 11 is provided on an accelerator pedal 14a, and is provided on an accelerator opening sensor 14b serving as an accelerator opening detecting means for detecting the depression amount of the accelerator pedal, and a change lever 15a for controlling the shift of the transmission 2. The speed change switch 15b is also connected, and the transmission ECU 11 performs a shift operation by comprehensively determining these input signals.
[0016]
Further, the clutch control device according to the present invention is provided with a filter 23 for cutting a high frequency component of the rotation speed signal from the clutch rotation speed sensor 12. Specifically, the filter 23 is provided in the middle of the input path from the clutch speed sensor 12 to the transmission ECU 11. By applying a filter to the clutch speed signal, disturbances such as vibrations of the shaft which become high frequency components can be eliminated from the original clutch speed signal, and an appropriate clutch speed (signal) can be detected. It becomes. As a result, even if the clutch rotational speed fluctuates due to the influence of disturbance, the clutch connection operation is not performed unexpectedly.
[0017]
The clutch device 3 is brought into a connected state by pressing a clutch plate 17 against a flywheel 16 connected to an output shaft of the engine 1 with a spring 18, while being disconnected by separating the clutch plate 17 from the flywheel 16. Thus, it is a normal mechanical friction type clutch for connecting and disconnecting the engine 1 and the transmission 2 and can automatically perform the connecting and disconnecting operation. An air cylinder 19 serving as a clutch connecting / disconnecting means is connected to the clutch plate 17 via a lever 20. Two air passages 9a and 9b connected to the air cylinder 19 are connected to two electromagnetic air pressure proportional control valves ( The control valve 21a and 21b are controlled to open and close, respectively, to supply and discharge the high-pressure operating air supplied from the air tank 9, to automatically operate the air cylinder 19, and to operate the clutch plate 12 To automatically connect and disconnect the clutch. A lever 20 connected to the air cylinder 19 is provided with a clutch stroke sensor 22 that indicates the operating position of the clutch plate 17, and a detection signal from the clutch stroke sensor 22 is input to the transmission ECU 11, and a control valve is provided. By controlling the open / close state of each of the clutches 21a and 21b, not only the two states of clutch connection / disconnection but also a state like a half clutch in a manual transmission can be achieved. By performing such control, when transmitting the output of the engine 1 to the transmission 2, it is possible to smoothly shift without any discomfort.
[0018]
Specifically, a spring is provided on one side of the piston (the side to which the lever 20 is connected) inside the air cylinder 19, and when the control valve 21a is turned on, the control valve 21a is placed in the space on the other side of the piston. , The piston is pushed in the direction against the spring, the lever 20 rotates about the fulcrum, and the clutch plate 17 moves in the direction away from the flywheel 16 to move the clutch. The device 3 changes from the connected state to the disconnected state. On the other hand, when the control valves 21a and 21b are both turned off, the high-pressure operating air introduced into the air cylinder 19 passes through the control valves 21a and 21b to one side of the air cylinder 19 that is open to the atmosphere. , The piston is pushed back by the force of the spring, the lever 20 rotates about the fulcrum, the clutch plate 17 moves in the direction of the flywheel 16, and the clutch device 3 changes from the disconnected state to the connected state. At this time, the clutch plate 17 is pressed against the flywheel 16 by the spring 18 and the clutch device 3 is held in the connected state. The clutch device 3 is controlled so as to be automatically connected and disconnected when the transmission 2 is automatically shifted. In the clutch control according to the present invention, the clutch device 3 is automatically connected and disconnected under predetermined conditions. It is controlled as follows.
[0019]
The transmission ECU 11 and the engine ECU 5 that perform such control include a microcomputer (CPU), a memory (including a ROM having a control program and data, and a RAM serving as a calculation work area), and a processing circuit for input / output signals. Interface. In the transmission ECU 11, among the various input signals, the main input signals according to the present invention include a clutch rotational speed sensor 12 (after processing of the filter 23), an accelerator opening sensor 14b, a clutch stroke sensor 22, and the like. Among the various output signals, a main output signal according to the present invention is a control signal to the control valves 21a, 21b and the like. An appropriate control signal is output by the control program based on the information input from the sensor or the like, and the clutch control according to the present invention is performed.
[0020]
FIG. 2 is a flowchart of clutch control showing an example of the embodiment of the present invention. Here, the control part according to the present invention is extracted and described.
[0021]
In steps S1 and S2, conditions for operating the clutch from the connected state to the disconnected state include a clutch disengagement speed N1 at which the clutch speed (NCL) from the clutch speed sensor reaches a predetermined speed during deceleration or stoppage. It must be smaller. When this condition is satisfied, the clutch is disengaged. Here, the clutch disengagement rotational speed N1 is, for example, the idle rotational speed of the engine. However, the rotational speed is not necessarily limited to the idle rotational speed as long as the rotational speed does not cause engine stall.
[0022]
In steps S3 and S4, conversely, as conditions for operating the clutch from the disengaged state to the connected state, the condition is that the accelerator signal from the accelerator opening sensor is off and the clutch rotation speed (NCL) is filtered. The condition (fNCL) must be greater than the clutch connection speed N1. Such a situation corresponds to, for example, a case where the vehicle speed is increased by releasing the brake on a downhill road and coasting.
When this condition is satisfied, the clutch connection operation is performed. Here, the clutch rotational speed (fNCL) is obtained by cutting a high frequency component of the actual clutch rotational speed (NCL). Even if the clutch rotational speed (NCL) fluctuates due to disturbance or the like, the influence of the fluctuation is considered. Has been eliminated. As a result, even when an abnormal fluctuation occurs in the clutch rotation speed due to torsional vibration or the like, unexpected clutch connection operation does not occur, and engine stall can be prevented.
[0023]
FIG. 3 is a comparison diagram of the conventional clutch control and the clutch control of the present invention.
[0024]
As shown in FIG. 3A, in the conventional clutch control, when the clutch rotation speed becomes unexpectedly larger than the clutch connection / disconnection rotation speed N1 due to torsional vibration or the like (for example, point A in FIG. 3). In this case, the engine stall occurs because the clutch is engaged. However, as shown in FIG. 3B, in the clutch control according to the present invention, the clutch rotation speed (NCL) may unexpectedly become larger than the clutch connection / disconnection rotation speed N1 due to torsional vibration or the like. Also, by using the clutch rotation speed (fNCL) that is a filter of the clutch rotation speed (NCL), fluctuations are eliminated, and the clutch engagement operation is prevented from being performed erroneously to prevent engine stall. I have.
[0025]
【The invention's effect】
According to the present invention, by applying a filter to the clutch rotation speed, the clutch rotation speed fluctuated by torsional vibration is apparently reduced, and the clutch rotation speed does not exceed the clutch connection / disconnection rotation speed. As a result, the condition for bringing the clutch into the engaged state is not satisfied, and the clutch can be kept in the disengaged state to prevent engine stall.
[Brief description of the drawings]
FIG.
1 is a schematic configuration diagram of an engine, a clutch device, and a transmission in which a clutch control device according to the present invention is used.
FIG. 2
4 is a flowchart of clutch control showing an example of the embodiment of the present invention.
FIG. 3
FIG. 4 is a comparison diagram of the conventional clutch control and the clutch control of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Engine 2 Transmission 3 Clutch device 11 Transmission ECU
12 clutch speed sensor 14a accelerator pedal 14b accelerator opening sensor 16 flywheel 17 clutch plate 18 spring 19 air cylinder 20 lever 21 control valve 22 clutch stroke sensor 23 filter

Claims (1)

Clutch connection / disconnection means for connecting / disconnecting a clutch between an engine and a transmission of a vehicle, clutch rotation number detection means for detecting the rotation number of the clutch, and accelerator opening degree detection means for detecting an amount of depression of an accelerator pedal; A clutch having clutch control means for automatically disengaging the clutch using the clutch connection / disconnection means when the rotational speed of the clutch in a connected state with the engine is lower than a predetermined rotational speed. In the control device,
Providing a filter that cuts high frequency components of the clutch rotation speed signal from the clutch rotation speed detection means,
The clutch control unit may be configured such that the accelerator signal from the accelerator opening detection unit is off, and the number of revolutions of the clutch in a disconnected state with the engine signal-processed by the filter is greater than the predetermined number of revolutions. A clutch control device, wherein the clutch is automatically brought into a connected state using the clutch connecting / disconnecting means.

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