JPH09196163A - Clutch monitoring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To monitor the wear of a clutch. SOLUTION: A monitoring device of a clutch monitors a non-allowable wear of the clutch provided between an engine 10 and a transmission 12, and is provided with a monitoring means 16a. When the prescribed action condition is present, the monitoring means compares the value |Nmot-NT | to express the slip present in the clutch with at least one prescribed threshold S1. When the slip of the clutch is larger than the threshold, the clutch is judged to be worn.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clutch monitoring device.

[0002]

It is known from the prior art to provide converters for torque conversion. This converter
Can be bridged by the clutch. About this, for example, “Kraftfagrtechnische Handbuch”, 21.Auflag
See e 1991, 539-541 pp. Furthermore, it is known to use clutches to separate the force coupling between the vehicle engine and the transmission.

It is also known, for example from DE-OS 4304596, to control a converter clutch in order to adjust the desired converter slip.

DE-A1-3334725 to DE-
In the device described in A1-3828128, the clutch is monitored to prevent overheating. DE-A1
In the configuration described in −3624008, the energy consumption of the clutch is detected by the slip detection in the clutch process. When the energy consumption of the clutch thus detected exceeds a predetermined value during the clutch process, an alarm signal is issued.

[0005]

The object of the invention is to monitor the function of the clutch.

[0006]

According to the present invention, there is provided a device for monitoring unacceptable wear of a clutch provided between a vehicle engine and a transmission, the monitoring device being provided with monitoring means. The means are solved by comparing a value representative of slip present in the clutch with at least one predetermined threshold value when a predetermined operating condition is present.

[0007]

DETAILED DESCRIPTION OF THE INVENTION As already mentioned, the present invention relates to a device for monitoring a clutch provided between a vehicle engine and a transmission for unacceptable slip. For this purpose, monitoring means is provided, which detects the value of the slip present in the clutch when a predetermined operating condition is present. This value is compared to at least one predetermined threshold.

With the device of the present invention, the clutch is monitored for clutch wear that has already occurred.

In the configuration of the present invention, the clutch is configured as a converter clutch, generally in combination with an automatic transmission. Another configuration of the invention contemplates a clutch that can be disengaged from the vehicle engine and the transmission by a complete disengagement.

In an advantageous configuration of the invention, a converter is also provided between the vehicle engine and the transmission, which converter is bridged by the converter clutch. Here, the converter clutch is monitored as the clutch.

The failure of the converter clutch used for bridging the torque converter may deteriorate the running characteristics and exhaust gas characteristics of the automobile, and therefore the converter clutch needs to be monitored. It is especially advantageous here to monitor unacceptably high converter slips. Such a failure may be caused, for example, by a converter clutch regulator failure or a converter clutch lining plate failure.

According to the present invention having this structure, it is possible to identify an error in a converter clutch of a type in which a desired slip is adjusted by controlling the converter clutch or a converter clutch of a type in which the converter is completely bridged or opened. It is not necessary to distinguish between these clutch types. Furthermore, the invention does not relate to whether the control of the converter clutch is performed by analog control, clock control or digital control (close / open of the converter clutch).

One advantageous configuration of the invention relates to the control converter clutch described above, in which controllable means are provided for adjusting the converter clutch to the desired slip. The predetermined operating conditions under which the monitoring of the present invention occurs are when the converter clutch is controlled to accommodate small slips. Accordingly, the following failure of the converter clutch can also be detected. That is, it is possible to detect a fault in which the converter clutch is closed correctly and completely, but unacceptably high slip occurs in the transition region to the open state.

With a converter clutch that simply bridges or opens the converter, the predetermined operating condition under which the monitoring of the present invention is performed is when the converter clutch is controlled to completely close the clutch.

Further, the predetermined operating condition under which the monitoring of the present invention is performed may be when the output torque of the vehicle engine falls below a predetermined second threshold value. Since the converter slip depends on its input torque, that is, the engine torque, this configuration causes the converter slip to be relatively small when the clutch is operating normally. This configuration takes into consideration that some slip occurs when the engine torque is very large even when the converter clutch is operating correctly.

The existence of certain operating conditions under which the monitoring of the invention takes place makes the adjustment of small slip and the low engine torque dependent.

Advantageously, depending on the comparison result, the predetermined measure is initiated. In that case, for example, control of an error indication and / or disengagement of the converter clutch is carried out in order to initiate such a means. For example, a driver of a vehicle or machine can be instructed by a warning instruction that the clutch operation is defective. The comparison result obtained according to the invention can then be first filtered and the procedure can only be started depending on the filtered comparison result. Such filtering (e.g., by an integrator) ensures that short-term fluctuations in the converter or clutch slip do not immediately initiate a response.

The means or response is initiated when the slip present in the converter clutch (eg, the absolute value of the difference between the input speed and the output speed of the converter or clutch) exceeds a predetermined first threshold value for a predetermined duration. can do. This also ensures that short-term fluctuations in the converter or clutch slip do not immediately cause an error message.

In general, the converter clutch can be operated by hydraulic adjustment pressure. The predetermined operating condition under which the monitoring of the invention is carried out is in this case that the hydraulic regulating pressure is above a third threshold value. In this case, it is assumed that the clutch is closed when the clutch pressure is high. This embodiment has the same background as the previously described embodiment in which the converter clutch is controlled to accommodate small slips. With this, the following failure of the converter clutch can be detected. That is to say, it is possible to detect a fault in which the bar clutch is now correctly and completely closed, but in the transition region to the released state an unacceptably large slip occurs.

The above-mentioned first, second and third threshold values can be fixedly set, or can be set depending on operating parameters representing or controlling the operating state of the converter clutch. For example, the first, second, and third thresholds can be set by a characteristic curve or a characteristic map depending on operating parameters. This operating parameter also represents or controls the operating state of the converter clutch. Such operating parameters may be converter clutch condition and / or temperature.

As already mentioned, another aspect of the invention relates to a clutch, which is capable of disconnecting the force connection between the vehicle engine and the transmission by means of a clutch opening control. Here, a clutch that is directly operated by the driver is handled. This clutch separates the vehicle engine from the transmission during the transmission switching process. The predetermined operating condition under which the present invention is monitored is when the clutch is controlled to be fully closed.

After the end of the clutch process, the clutch must firmly connect the engine and the drive shaft. As the life of the clutch approaches, the pressing force of the clutch gradually weakens, and the maximum torque that can be transmitted by the clutch decreases.
At this stage, slipping occurs even when the clutch is closed, that is, after the end of the clutch process.

Thus, in an advantageous form of this embodiment, the predetermined operating condition is that the output torque of the vehicle engine and / or the engine controlled variable (controlling and / or representing the output torque of the vehicle engine) is a predetermined fourth threshold value. It is time to exceed. Here, for example, the injection quantity and / or the engine load can be considered.

In the presence of clutch wear, this is first detected by the increase in slip during the transmission of large clutch torques. The detection of this slip when the clutch is closed informs the driver that the clutch should be replaced in a timely manner, shortly after the end of the clutch process. This is done before the actual failure occurs. For this purpose, means are initiated depending on the comparison result of the invention. Here, starting this means includes controlling an error instruction.

Further, in response to the comparison results of the present invention, the control of the vehicle engine can be modified to reduce the maximum output torque of the vehicle engine. This prolongs the life of the clutch. This is because it is sufficient to transmit a relatively small torque.

The first threshold value is preferably set as a function of the speed ratio which is adjusted instantaneously.

Further advantageous configurations of the invention are described in the dependent claims.

[0028]

1 and 4, two exemplary embodiments of the device according to the invention are shown as block circuit diagrams.

2, 3, 5 and 6 are slow charts of the method of the present invention.

The present invention will be described below based on examples. Here, FIGS. 1, 2, and 3 explain the present invention based on a converter clutch, and FIGS. 4, 5, and 6 explain a present invention based on a separation clutch.

In FIG. 1, a vehicle engine is indicated by 10. The drive unit of the vehicle engine is controlled by the engine control device 10a. The output shaft of the engine 10 is connected to the input side of the hydraulic converter 11. The output of this converter is guided to the wheels 13 of the vehicle via a transmission 12 (for example an automatic transmission) and optionally an output differential transmission not shown. The converter 11 can be mechanically bridged by a converter clutch 17. For this purpose, the converter clutch 17 has a part 16 of the control device 16.
A predetermined converter clutch pressure is applied by b.
In this case, the original control device 16 outputs the output signal Pwk. This signal corresponds to the converter clutch pressure to be adjusted. In order to obtain the control signal Pwk, the control device 16 is supplied with the pump rotational speed and turbine rotational speed (input rotational speed and output rotational speed of the converter) Nmot and NT detected by the sensors 14 and 15, for example. As is known per se, the control signal can be determined in dependence on the engine drive data (for example present in the engine control unit 10a) and the instantaneous converter slip (Nmot-NT). Here, the control signal can be configured such that the clutch 17 can only be completely closed or opened (the control signal has the values "Auf" and "Zu"). Alternatively, the converter control can be performed to control clutch slip or converter slip to a predetermined value in a known manner. In the latter case, the control signal Pwk can be an analog signal or a clock signal (eg pulse width modulation). Furthermore, the control device for controlling the converter clutch 17 is generally integrated with the transmission control device. The transmission control device controls the gear ratio i of the automatic transmission 12.

Of importance to the present invention is the configuration of the monitoring unit shown at 16a. This monitoring unit generally constitutes the whole unit together with the control device 16b. The monitoring unit 16a includes the engine torque Mmot from the engine control device 10a, the engine speed Nmot (detected by the sensor 14 or present in the engine control device 10a), and the turbine speed detected by the speed sensor 15. NT and control signal Pwk are supplied. The monitoring unit 16a controls the indicating device 18 for an error indication by forming the signal S.

FIG. 2 shows the operation of the monitoring unit 16a. After the start step 201, first step 202
At, engine torque Mmot, engine speed Nmot, turbine speed NT and control signal Pwk are read. In step 203, it is determined whether or not a predetermined inspection condition exists. The detection of the presence of the inspection condition will be described in detail with reference to FIG. If the inspection condition does not exist, the process directly jumps to the end step 206. If an inspection condition exists, then in step 204 the absolute value of the clutch slip or converter slip | Nmot-NT | is compared with a threshold value S1. When the value | Nmot-NT | falls below the threshold value S1, the process jumps to the end step 206. Otherwise, in step 205, optionally after filtering, the signal S
Is formed. This is because the error is indicated by the indicator 18. After the end step 206, the flow shown in FIG. 2 is newly started.

After the start step 301 shown in FIG. 3, in step 302, the engine torque Mmot and the control signal P
wk is read. In step 303, the control signal P
It is checked whether wk has exceeded a (relatively large) threshold value S3 (here it is assumed that a high clutch pressure closes the converter clutch). If it exceeds, that is, if the clutch is closed, the routine jumps to step 304. If this is not the case (the control signal Pwk falls below a relatively large threshold value S3), this means that the clutch may be open. That is, a slight slip may exist even when the clutch is operating normally. In this case, the process directly jumps to the end step 306.

There are three clutch states in the background of inquiry 303.

1. The clutch is completely closed.

2. The clutch is completely open.

3. The clutch is slightly open for control to the desired slip.

In the second case no test is carried out, but in the first case a test according to the invention of the conditions queried in step 304 is preferably carried out. In the third case, if the clutch is out of order, the clutch adjustment pressure Pwk is further increased until the clutch adjustment pressure Pwk exceeds the threshold value S3 in order to control a predetermined slip. Based on this, two conditions (steps 303 and 3)
One of 04) (step 303) is satisfied.

In the following step 304, the engine torque M
mot is compared to a relatively small threshold S2. If the engine torque exceeds the threshold value S2, this means that the input torque of the converter is large and a relatively large slip due to the converter can be adjusted. in this case,
The function of the converter clutch is difficult to check for unacceptable slip.

For example, when the engine torque is sufficiently small,
This means that relatively small converter slips are expected. In this case, converter slip or clutch slip can be evaluated and converter clutch function testing can be performed for unacceptable slip. This is indicated by step 305.
After the end step 306, the flow shown in FIG. 3 newly starts.

The following are examples of the values for the threshold values S1, S2 and S3.

S1 = 20 U / min S2 = 100 Nm S3≈5 bar where U is rotation, min is minutes, N is Newton, and m is meters.

In FIG. 4, a vehicle engine is indicated by 410. The driving of the vehicle engine is controlled by the engine control unit 410a. The output shaft of engine 410 is coupled to the input side of clutch 417, the output of which is transmitted to vehicle wheels 413 via transmission 412 (eg, conventional hand-shift transmission) and optionally a differential transmission (not shown).

Here, a clutch known per se is operated via a clutch pedal 421 operated by the driver. However, the operation K can also be performed by a clutch adjuster (not shown). This clutch regulator is operated either directly by the driver or by a control device within the framework of an automatic handshift transmission.

Of importance to the present invention is the configuration of the monitoring unit shown at 416a. The monitoring unit may advantageously be a component of engine control 410a. The monitoring unit 416a includes an engine torque Mmot from the engine control device 410a and an engine speed Nmot (sensor 414).
(Or present in the engine control unit 410a), the transmission output speed Nab detected by the speed sensor 420 is supplied. The monitoring unit 416a can control the indicating device 418 to indicate excessive clutch wear by forming the signal S.
Furthermore, the signal S generated by the monitoring unit 416a
Is supplied to the engine control unit 410a. As a result, the maximum engine torque described above is reduced.

FIG. 5 shows the function of the monitoring unit 416a. After start step 501, first step 502
The engine torque Mmot, the engine speed Nmot, the transmission output speed Nab, the clutch control K, and the instantaneous transmission gear ratio I are read out. In step 503, it is inspected whether a predetermined inspection condition exists. The detection of the presence of the inspection condition will be described in detail with reference to FIG. If the inspection condition does not exist,
Jump to end step 507.

If the inspection condition exists, the ratio Nab of the transmission output speed and the engine speed Nab is determined in step 504.
/ Nmot is compared to the instantaneous transmission ratio I. Ratio Nab / N
If mot does not exceed the value I, end step 507.
Jump to. Otherwise, in step 505,
The signal S is formed, possibly after filtering, excessive clutch wear is indicated by the indicator 418 and the maximum engine torque is reduced. After the end step 507, the flow shown in FIG. 5 newly starts.

After the start step shown in FIG. 6, step 60 is performed to detect whether the inspection condition exists.
At 2, the engine torque Mmot and the clutch control K are read. In step 603 the clutch control K is checked to see if the clutch is fully closed. Then step 6
When it is detected in 04 that a relatively large engine torque exists (threshold value S4), it is detected in step 605 that the inspection condition exists.

[Brief description of the drawings]

FIG. 1 is a block circuit diagram of an embodiment of the device of the present invention.

FIG. 2 is a flowchart of the method of the present invention.

FIG. 3 is a flow chart of the method of the present invention.

FIG. 4 is a block circuit diagram of an embodiment of the device of the present invention.

FIG. 5 is a flowchart of the method of the present invention.

FIG. 6 is a flow chart of the method of the present invention.

[Explanation of symbols]

 10 Vehicle Engine 11 Converter 12 Transmission 13 Wheels 16 Control Device 17 Converter Clutch

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Thomas Luping, Germany, Renningen im Blumenring 9 (72) Inventor, Marzel Hachameister, Federal Republic of Germany Korntal-Müngen Christian-Wagner-Strasse 10 (72) Invention By Ralph Krevin Germany Stuttgart Sütilnenweg 19

Claims (15)

[Claims] 1. A device for monitoring unacceptable wear of a clutch provided between a vehicle engine (10, 410) and a transmission (12, 412), the device including monitoring means (16a, 416). When the predetermined operating condition is present, the monitoring means has a value (| Nmot-NT |, Nab / N) representing the slip present in the clutch.
mot) is compared with at least one predetermined threshold value (S1, I). 2. A converter (11) is provided between a vehicle engine (10) and a transmission (12), said converter being bridged by a converter clutch (17), and the converter clutch (1) serving as a clutch.
The monitoring device according to claim 1, which monitors 7). 3. Means (16a) are provided for adjusting and controlling the converter clutch (17) to a desired slip, the predetermined operating conditions being that the converter clutch (17) adjusts a slight slip, Or the monitoring device of claim 2, which is present when controlled to close completely. 4. The monitoring device according to claim 2, wherein the predetermined operating condition exists when the output torque (Mmot) of the vehicle engine (10) falls below a predetermined second threshold value. 5. Monitoring device according to claim 2, characterized in that the means is started depending on the comparison result and the error indication (18) is controlled and / or the converter clutch (17) is opened to start the means. . 6. The monitoring device according to claim 5, wherein the comparison result is filtered and the means is started depending on the filtered comparison result. 7. A converter clutch (1)
7) value representing slip present in ((Nmot-NT
7. The device according to claim 5, which starts when |) exceeds a predetermined first threshold value (S1) for a predetermined duration. 8. The converter clutch (17) is operated by a hydraulic adjustment pressure (Pwk), and the predetermined operating condition exists when the hydraulic adjustment pressure (Pwk) exceeds a third threshold value (S3). The monitoring device according to claim 2. 9. The first or second or third threshold value (S
Monitoring device according to claim 2, 4 or 7 or 8, wherein 1, S2, S3) are set depending on operating parameters that represent or control the operating state of the converter clutch (17). 10. The first or second or third threshold value (S
1, S2, S3) are set by a characteristic curve or a characteristic map depending on the operating parameters that represent or control the operating state of the converter clutch (17). Monitoring equipment. 11. Monitoring device according to claim 9 or 10, characterized in that the operating parameter is the condition and / or the temperature of the converter clutch (17). 12. Force control between the vehicle engine and the transmission can be interrupted by controlling (K) the clutch (417) to open, and the predetermined operating condition is that the clutch is completely closed. The monitoring device of claim 1, which is present when controlled to occur. 13. The predetermined operating condition is vehicle engine (41
13. The monitoring device according to claim 12, which is present when an engine control amount that controls and / or represents the output torque (Mmot) of 0) and / or the output torque of the vehicle engine exceeds a predetermined fourth threshold value (S4). 14. Starting means depending on the comparison result and controlling (S) an error indication (418) to start said means.
And / or modifying the control of the vehicle engine (410) to reduce the maximum output torque (Mmot) of the vehicle engine. 15. The monitoring device according to claim 12, wherein the first threshold value depends on the gear ratio (I) which is adjusted instantaneously.