JPH0726654B2 - Friction clutch connection detection method and apparatus - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a friction clutch connection detection method and device, and more particularly, by detecting a connection point of a clutch provided in the middle of a traveling power transmission mechanism of a vehicle, The present invention relates to a method and an apparatus preferably used to obtain smooth vehicle movement at the time of starting.

[Background of the Invention]

2. Description of the Related Art Conventionally, there is a so-called automatic brake device or the like which is used for mechanically and automatically ensuring a stopped state of a vehicle. With this device, it is necessary to automatically release the hydraulic pressure in the brake device that is being held when the vehicle starts, so there has been a proposal to determine the vehicle start point by using an operation such as stepping on the accelerator pedal. ing.

By the way, when the vehicle start time is obtained by such a method, there is no particular problem in a so-called automatic vehicle, but it may be insufficient in a vehicle in which the transmission is manually operated (hereinafter referred to as a "manual vehicle"). It has become recognized that there is a tendency for detection of the vehicle start time to be required. To explain this concretely, in a manual vehicle, when the vehicle is started by depressing the accelerator pedal or releasing the clutch pedal, these operation timings are uniformly set by the operator's habit. If the clutch is not connected and is not connected when the accelerator pedal is depressed, it will lead to the problem of causing the vehicle to slip when starting on a slope.

A method may be considered in which the clutch pedal is provided with a stroke detection switch for stepping on and off the clutch pedal, but it is difficult to detect connection / disconnection of the clutch.

[Object of the Invention]

SUMMARY OF THE INVENTION From the above viewpoints, it is an object of the present invention to provide a friction clutch connection detection method and device which are preferably used for accurately detecting the time point of brake release in an automatic brake device.

[Outline of Invention]

The feature of the friction clutch connection detection method of the present invention that achieves the above-mentioned object is that vibrations of a certain value or more occurring in the power transmission side member at the time of connection of the friction clutch are detected, and the transmission is set to a low gear. The condition is that the clutch connection point is detected.

Further, the feature of the friction clutch connection detection device of the present invention for specifically carrying out such a method is that a piezoelectric element attached to a power transmission side member of the friction clutch to detect vibration of a predetermined frequency, The friction clutch connection is detected by the logical product of the vibration detection circuit connected to the piezoelectric element, the gear detection means for detecting that the transmission is set to the low gear, and the detection of the vibration detection circuit and the detection of the gear detection means. And a logical product circuit for

The present invention can be applied to various kinds of control that requires detection of the time point when the clutch is switched from the non-connected state to the connected state, and can be preferably used particularly for releasing the brake of the automatic brake device.

As the power transmission side member of the device of the present invention, a member that does not interfere with the attachment of the piezoelectric element and the configuration of connection is appropriately selected, and for example, a clutch release lever or the like may be used. For the vibration detection frequency, for example, a bandpass filter may be used to determine the pass frequency range.

Needless to say, when the connection detection is applied to another control, an appropriate delay circuit or the like may be used together.

Example of Invention

 Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, 1 is a transmission, 2 is a clutch cylinder, 3 is a clutch release lever connected to the piston of this clutch cylinder 2, and a friction clutch (positioned at the front stage (engine side) of the transmission). The structure forms a part of the power-transmitted member (not shown). This friction clutch 4 is a known one, and the clutch release lever 3 is actuated by the clutch cylinder when the clutch pedal (not shown) is stepped on, so that the clutch is disconnected. When the pedal is released, the clutch is connected again.

With respect to the clutch release lever 3 of the clutch having such a structure, in the present example, in order to measure the vibration in the vertical direction, the horizontal direction, and the front-back direction, the vibration pick-ups 5, 6, 7 made of piezoelectric elements (for example, PZT) are respectively provided. The vibration pick-up 5, 6 and 7 signals are attached to the second
As shown in the figure, the input signal is input to the clutch connection point detection circuit 9.

The detection circuit 9 in the present example is an AND circuit (logical product circuit) for determining that the transmission gear is in the (low) state in order to detect the clutch connection when the stopped vehicle starts. 8), the clutch connection detection signal is output when the vibration detection from the vibration pick-up exceeds a predetermined constant G.

In the above, the vibration of the transmitted frequency may be detected by using a band pass filter, which can be appropriately selected and determined according to the characteristics of the vehicle, the clutch mechanism, and the like.

FIG. 3 shows the waveform analysis result of the vibration signal detected by such a detection device, and it was found that the clutch connection can be clearly detected at the time point t ₀ in the figure.

In order to further examine the effectiveness of such a detection method,
The operating conditions for the clutch connection were moderate, normal, and abruptly enough to cause knocking, and tests were also performed when the vehicle was running and when the gear ratio was changed. As a result, it was clarified that the S / N ratio (signal / noise ratio) was obtained enough to satisfy the purpose of vibration detection, and it was found that accurate and stable clutch connection detection could be achieved.

In the above embodiment, the vibration of the clutch release lever in the three directions of up, down, left and right, and front and back is detected. However, since vibration can be detected in any of these direction components, one direction You may do only about a component. The member for detecting the vibration may be any member as long as it does not interfere with the attachment of the vibration pick-up as the member on the power transmission side specified by the clutch release lever.

〔The invention's effect〕

As described above, the friction clutch connection detection method and apparatus according to the present invention realizes accurate and stable clutch connection detection by a novel method and apparatus that have not been used in the past. When used for a brake release signal, etc., good control that has never been achieved is realized, and conventional mechanical detection by pedal stroke requires adjustment by the user due to wear of the clutch facing, but with this method There is also the effect that no adjustment is required at all, and its usefulness is extremely large.

[Brief description of drawings]

The drawings show one embodiment of the present invention. FIG. 1 is a view showing an attachment mode of a piezoelectric element which is a detection element, and FIG. FIG. 3 is a block diagram for this purpose, and FIG. 3 is a diagram showing the characteristics of the detected vibration signal. 1 …… Transmission 2 …… Crutch cylinder 3 …… Clutch release lever 4 …… Friction clutch 5,6,7 …… Vibration pick up 8 …… And circuit.

Claims (3)

[Claims] 1. When the friction clutch is engaged, vibration of a power transmission side member above a certain value is detected, and the clutch engagement time is detected on condition that the transmission is set to a low gear. Friction clutch connection detection method. 2. A piezoelectric element attached to a power transmission side member of a friction clutch to detect vibration of a predetermined frequency, a vibration detection circuit connected to the piezoelectric element, and a transmission set in a low gear. A friction clutch connection detection circuit that detects a friction clutch connection by a logical product of the detection of the vibration detection circuit and the detection of the gear detection unit. apparatus. 3. The friction clutch connection detection device according to claim 2, wherein the friction clutch is provided in the middle of the power transmission mechanism of the vehicle.