JPH0297765A - Abnormality detecting device for automatic transmission - Google Patents

Abstract

PURPOSE:To contrive the miniaturization and the cost down by providing a comparing means which compares a speed change shift, indicated by a control signal, with a speed change shift obtained by a speed change shift arithmetic means. CONSTITUTION:An output from an input shaft speed detector 28 and an output from an output shaft speed detector 29 are given to a processing circuit 31 calculating an actual speed change shift to be obtained. This calculating result is compared with a control signal for indicating a speed change shift of an automatic transmission 20. As the result, when the indicated speed change shift, shown by the control signal, agrees with the actual speed change shift obtained by calculation in the processing circuit 31, the automatic transmission 20 is judged to perform normal action, while when the speed change shifts are in no agreement, the automatic transmission 20 is judged to generate abnormality. By the constitution thus using so-called software, the abnormality is detected, and a device simplifies its constitution contriving the miniaturization and the cost down.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an abnormality detection device for an automatic transmission that converts the rotational power of an internal combustion engine or the like at an appropriate gear ratio and outputs the converted torque.

BACKGROUND OF THE INVENTION In the above-mentioned automatic transmission, the electromagnetic solenoid, which is a main component, is provided with a structure for detecting abnormalities such as short circuits and disconnections.When an abnormality is detected, the automatic transmission It is configured to perform a so-called fail-safe operation.

FIG. 4 is an electrical circuit diagram of a typical conventional automatic transmission drive circuit 1 having an abnormality detection function. This drive circuit 1 includes a rotation speed detector 2 that detects the rotation speed of the internal combustion engine, that is, the rotation speed of the input shaft of the automatic transmission, a rotation speed detector 3 that detects the rotation speed of the output shaft of the automatic transmission, etc. Based on the output from
6 is selectively energized/demagnetized to switch gears.

The drive circuit 1 for the electromagnetic solenoid 5 and the drive circuit 1a for the electromagnetic solenoid 6 are configured similarly, and for the sake of simplicity, the drive circuit 1 will be described below.

The output terminal a1 of the processing circuit 4 is connected to the connection point between the resistors R1, R2 of a series circuit consisting of resistors R1, R2, R3 interposed between the power supply lines 7.8. A connection point 10 between the resistors R2 and R3 of this series circuit is connected to the base of a transistor Q2, and the collector of this transistor Q2 is connected to the power supply line 7 via a resistor R4. Further, a connection point 11 between the collector of the transistor Q2 and the resistor R4 is connected to the base of the transistor Q1, and the transistor Q1. The emitters of Q2 are commonly connected to the power supply line 8 on the ground side.

■・The collector of transistor Q1 is connected via resistor R5,
Connected to the collector of transistor Q5 and the base of transistor Q6. (2) The emitter of transistor Q6 is connected to high level power supply B via resistor R6. l
・Connection point 12 between the emitter of transistor Q6 and resistor R6
is connected to the base of the transistor Q5, and the emitter of this transistor Q5 is connected to the high level @v
! Connected to A+F3.

The input terminal b1 of the processing circuit 4 is connected to the power supply line 7 via a resistor R7, and is also connected to the collector of a transistor Q4. The base of the transistor Q4 is connected to the high level power supply +B via the transistor Q3.
is divided and supplied by resistors R8 and R9. The high-level power supply B is voltage-divided and supplied to the base of the transistor Q3 by resistors RIO and R11. A capacitor C1 is interposed between the base and emitter of this transistor Q3. A connection point 13 between the resistor R11 and the electromagnetic solenoid 5 is connected to the power supply line 8 via a reversely connected diode D1.

In the drive circuit 1 configured as described above, when the electromagnetic solenoid 5 is normal, when the output terminal a1 of the processing circuit 4 is set to low level, the transistor Q2 is cut off, which makes the transistor Q1 conductive, and the transistor Q5. Q6 becomes conductive, power is supplied from transistor Q6 to electromagnetic solenoid 5, and electromagnetic solenoid 5 is excited. As a result, the transistor Q3 is cut off, the transistor Q4 is cut off, and the input terminal b1 of the processing circuit 4 becomes high level.

Also, by setting the output terminal a to high level,
Transistor Q2 conducts and transistor Q1 becomes 31!
As a result, the transistors Q5 and Q6 are cut off, cutting off the supply of power to the electromagnetic solenoid 5, and the electromagnetic solenoid 5 is demagnetized.

As a result, the transistor Q3 becomes conductive, the transistor Q4 becomes conductive, and the input terminal b1 becomes low level.

On the other hand, when the electromagnetic solenoid 5 is short-circuited, even if the output terminal a1 is set to a low level as described above, the transistor Q3. Q4 becomes conductive and the input terminal b1 becomes low level.

Further, when the electromagnetic solenoid 5 is disconnected, even if the output terminal a1 is set to high level as described above, the transistor Q3. Q4 is cut off, and the input terminal b1 becomes high level. That is, an abnormality in the electromagnetic solenoid 5 can be detected from the input level of the input terminal b1 relative to the output level of the output terminal a1, as shown in Table 1.

Table 1 In this first table, logic "0" represents a low level, logic r1. represents a high level, and the drive circuit 1a of the electromagnetic solenoid 6 connects the output terminal tt2 and the input terminal b of the processing circuit 4.
2.

Problems to be Solved by the Invention The drive circuit 1 of the prior art as described above is configured to detect an abnormality in the electromagnetic solenoid 5.6 by so-called hardware using transistors Q1 to Q6. Therefore, the number of parts is large, the size is large, and the cost is high.

An object of the present invention is to provide an abnormality detection device for an automatic transmission that can be made smaller and lower in cost.

Means for Solving the Problems The present invention provides an abnormality detection device for an automatic transmission that changes the gear position in response to a control signal so as to become the indicated gear position indicated by the control signal. an input shaft rotation speed detection means for detecting the speed; an output shaft rotation speed detection means for detecting the rotation speed of the output shaft of the automatic transmission; and a response to the outputs of the input shaft rotation speed detection means and the output shaft rotation speed detection means. and a gear position calculation means for calculating and determining the actual gear position, and a comparison means for comparing the gear position indicated by the control signal and the gear position determined by the gear position calculation means. This is an abnormality detection device for an automatic transmission characterized by:

The present invention also provides a gear change detecting means for detecting a change in the indicated gear according to the control signal; The present invention is an abnormality detection device for an automatic transmission, characterized in that it includes a comparison prohibition means for disabling the comparison means.

According to the present invention, the output of the input shaft rotational speed detection means and the output of the output shaft rotational speed detection means are given to the gear position calculation means, and this gear position calculation means is used to detect the detected automatic speed. The actual gear position is calculated from the rotational speed of the input shaft of the transmission and the rotational speed of the output shaft. This calculation result is given to the comparison means and is used as a control signal for instructing the gear position of the automatic transmission.

Therefore, as a result of the comparison operation, the instruction sentence 3g represented by the r control signal! When the gear position matches the actual gear position calculated by the calculation means, the automatic transmission is operating normally, and when they do not match, an abnormality has occurred in the automatic transmission. By detecting abnormalities using a configuration using so-called software in this way, the configuration can be simplified to achieve miniaturization and cost reduction.

Further, according to the present invention, when the gear change detecting means detects that the indicated gear indicated by the control signal has changed, the comparison inhibiting means prevents the comparison operation by the comparing means from the time when the indicated gear changes. It is prohibited only for a predetermined time. As a result, during the delay time of the hydraulic path when changing gears and the transition time until the number of revolutions of the internal combustion engine, that is, the number of revolutions of the input shaft and the number of revolutions of the output shaft of the automatic transmission match, The comparison operation is stopped, thereby preventing erroneous detection and performing a highly accurate abnormality detection function.

Embodiment FIG. 1 is a block diagram showing a drive circuit 22 of an automatic transmission 20 having an abnormality detection function according to an embodiment of the present invention, and its related configuration. Combustion air is supplied to the internal combustion engine 23 from a throttle valve 24 via an intake pipe 25 . The output of the internal combustion engine 23 is transmitted to the input shaft 21 of the automatic transmission 20.
The output from the automatic transmission 20 is transmitted to the wheels 27 via the output shaft 26.

The rotation speed of the input shaft 21, that is, the rotation speed N of the internal combustion engine 23
E is detected by a rotation speed detector 28, and the rotation speed SP of the output shaft 26 is detected by a rotation speed detector 29. The throttle valve 24 is provided with a throttle valve opening detector 30, and each of these detectors 28 to 30
The detection result is given to the processing circuit 31.

The processing circuit 31 is realized by, for example, a microcomputer, and calculates the value from the throttle valve opening θ detected by the throttle valve opening detector 30 and the rotation t&sp of the output shaft 26 detected by the rotation speed detector 29. 1&
Calculates the appropriate gear and instructs the calculation result to the gear SQ
L 0IJT, and a control signal representing this commanded gear position SQL OUT is derived to transistors Q11 and Q12, thereby causing electromagnetic solenoids SL and S2 of the automatic transmission 20 to
is selectively energized/demagnetized. In this way, the electromagnetic solenoid St.

By energizing/demagnetizing S2, for example, the second
The gear position is changed as shown in the table.

Table 2 F shows that the electromagnetic solenoids SL and S2 are demagnetized.

By switching the gears as described above, the following equation is established.

N E = K X S P
(1) However, the coefficient is the reduction ratio at each gear stage, and its value is shown in Table 3, for example.

Table 3 In this Table 2, ON means electromagnetic solenoid St,
32 is excited, and the OF processing circuit 31 also indicates that the internal combustion engine 2 detected by the rotation speed detector 28 is excited.
Based on the rotation speed NF of the automatic transmission 20 and the rotation speed SP of the output shaft 26 detected by the two rotation speed detectors, the actual gear position of the automatic transmission 20 is determined from the first equation.
Calculate and find.

The processing circuit 31 processes the commanded gear stage SQL O of the control signal.
UT is first compared with the actual gear position 1tEAL OUT calculated as described above, and transistor Q11 is
, Q12 and the electromagnetic solenoids Sl and S2. This judgment operation is performed, for example, between the commanded gear position SQL 0tlT and the actual gear position REAL.
This can be done by performing an exclusive OR with OUT. That is, when the instructed gear 5QLOUT and the actual gear REAL OUT match, the exclusive OR of the two is "o", and when they do not match, it is rlJ.

Next, the abnormality occurrence location is detected based on Table 4.

(Margins below) Table 4 In this Table 4, reference mark A refers to transistor Q.
Reference 'l! indicates that both ll and electromagnetic solenoid s1 are normal. fB indicates that at least one of the transistor Qll and the electromagnetic solenoid s1 is a
The reference mark C indicates that the transistor Ql
The reference numeral indicating that l is shorted indicates that both transistor Q12 and electromagnetic solenoid S2 are normal. The reference iE indicates that at least one of the transistor Q12 and the electromagnetic solenoid S2 is disconnected, and the reference F indicates the transistor Q1.
2 represents m-connection.

That is, for example, the instruction g from the processing circuit 31: gear SQ
When the actual gear stage REAL 0IIT is the second gear while the control signal L OUT is the first gear is being derived, the transistor Qll and the electromagnetic solenoid S
1 indicates that both are normal and transistor Q12 is short-circuited. Also, for example, the indicated gear position S
When the actual gear position REALOMIT is the first speed while a control signal is being derived that indicates that the QL OUT is the third speed, the transistor Q11 is short-circuited and at least one of the transistor Q12 and the electromagnetic solenoid S2 is short-circuited. Indicates that one side is disconnected. In this way, abnormalities in the transistors Qll, Q12 and the electromagnetic solenoids S1, S2 can be detected.

The above-mentioned abnormality detection operation
After a predetermined delay time W1 has elapsed since the control signal representing the change in T was derived, the actual gear position REAL 0
A comparison operation with tlT is performed. Therefore, processing circuit 3
1 has the functions of a gear stage calculation means, a comparison means, a YG stage change detection means, and a comparison prohibition means.

As shown in the second [2], when a control signal indicating a change in the commanded gear position SQL OUT is derived at time t1, the actual gear position is changed by the response delay time W l r, t due to the hydraulic path, etc. The operation starts from time t2.

In addition, after the shift operation is performed in this way, the transition time w1b until the time t3 at which the rotation speed corresponds to the reduction ratio of the gear and the rotation speed SP of the output shaft 26 in the changed gear is calculated. It takes. Therefore, the reference mark W
A delay time indicated by 1 is required. This delay time W1
If the above-mentioned comparison operation is performed in the above, an error will occur in the comparison result. This delay time W1 is, for example, about 2 to 3 seconds.

Therefore, in this embodiment, the abnormality detection operation is performed as follows.

FIG. 3 is a flowchart for explaining the operation. In step n1, each detector 28-
30 detection results are read, and in step rI2, the rotation t& of the output shaft 26 detected by the rotation speed detector 29 is read.
Vehicle speed is calculated from sp.

At the step port 3, the throttle valve opening θ detected by the throttle valve opening detector 30 and the rotation speed detector 2 are detected.
From the rotational speed SP of the output shaft 26 detected by 9 to g
: It is determined whether speeding up should be performed, and if not, the process moves to step rI6, and if so, the process moves to step rr4.

In step rr4, the optimum gear position is determined based on the throttle valve opening degree θ and the rotation t&SP, and the optimum gear position is set as the command gear position SQL OUT, and a control signal is derived to the l-transistors Qll and Q12. . step n
In step 5, the timer provided in the processing circuit 31 starts clocking, and the process returns to step n1.

If the gear shifting operation is not being performed in step n3, the process moves to step 116, where it is determined whether the clocking time of the timer has reached a predetermined delay time W1, for example, and if not, the process returns to step 41, Steps r11 to rI6 are thus repeated, and when the delay time W1 has elapsed, the process moves to step n7.

In step rr7, the rotational speed NE of the internal combustion engine 23 is determined, and the ratio between the rotational speed NE and the rotational speed SP is calculated. In step rI8, the step n
Actual gear stage REAL based on the calculation result in 7.
OUT is detected. In step r19, the command gear position SQL 0 of the control signal derived in step n4 is
tlT and the actual gear stage REAL 0IIT detected in step r+3, based on Table 4 above, the transistors Qll, Q12 and the electromagnetic lens Sl, 3 are determined.
2, it is detected whether or not an abnormality has occurred.

Thus, the drive circuit 22 of the automatic transmission 20 according to the invention
The transistors Ql 1. Q12 and electromagnetic solenoid St
, S2 is detected, the configuration can be simplified and the size and cost can be reduced. In addition, when the command gear position SQL OUT represented by the control signal changes, the abnormality detection operation is prohibited for a predetermined delay time W1, which prevents false detection in a transient state when the gear position is changed, and achieves high accuracy. It is possible to perform various detection operations.

The abnormality detection operation as described above is performed using one electromagnetic solenoid,
For example, the effect of the invention may be carried out only for Sl.rJ As described above, according to the present invention, the actual gear stage is calculated and determined from the rotational speed of the input shaft and the rotational speed of the output shaft, and this calculation result and When the control signal for instructing the automatic transmission to change gears matches the commanded gear position, the automatic transmission is operating normally, and when they do not match, an abnormality has occurred in the automatic transmission. Since the abnormality detection is performed by a configuration using so-called software, the configuration can be simplified and the size and cost can be reduced.

Further, according to the present invention, when the gear change detecting means detects that the indicated gear indicated by the control signal has changed, the comparison operation by the comparing means is performed for a predetermined time from the time of change of the indicated gear. This prohibits the delay time of the hydraulic path when changing gears and the number of revolutions of the internal combustion engine, that is, the time required until the number of revolutions of the input shaft and the number of revolutions of the output shaft of the automatic transmission match. During the transition time, the comparison operation is stopped, thereby preventing erroneous detection and allowing a highly accurate abnormality detection operation to be performed.

[Brief explanation of the drawing]

The first [21 is a block diagram showing the drive circuit 22 of the automatic transmission v120 according to an embodiment of the present invention and the configuration related thereto;
FIG. 2 is a graph showing changes in the rotational speed NE of the internal combustion engine rWJ23 and the rotational speed SP of the output shaft 26 when a speed change operation is performed, and FIG. 3 is a flowchart for explaining the operation.
Figure 4 is an electrical circuit diagram of the drive circuit 1 of the conventional automatic X'3 machine. ,ru. 20... automatic transmission, 21... input shaft, 22...
Drive circuit, 23--Internal combustion engine, 24--Throttle valve, 25--Input shaft, 26--Output shaft, 28.29
...-Rotational speed detector, 30... Throttle valve opening detector, 31... Processing circuit, SL, S2... Electromagnetic solenoid, Qll. Q12-・-■・Run register

Claims (2)

[Claims] (1) An input shaft rotation speed that detects the rotation speed of the input shaft of an automatic transmission in an abnormality detection device for an automatic transmission that changes the gear position in response to a control signal so as to achieve the indicated gear position indicated by the control signal. a detection means; an output shaft rotation speed detection means for detecting the rotation speed of an output shaft of the automatic transmission; and an output shaft rotation speed detection means for detecting an actual gear position in response to the outputs of the input shaft rotation speed detection means and the output shaft rotation speed detection means. An automatic gear shift characterized by comprising: a gear position calculation means for calculating and determining the gear position; and a comparison means for comparing the gear position indicated by the control signal and the gear position determined by the gear position calculation means. Machine abnormality detection device. (2) a gear change detection means for detecting a change in the indicated gear according to the control signal; and a comparison means responsive to the output of the gear change detection means for a predetermined period of time from the time when the indicated gear changes. 2. The abnormality detection device for an automatic transmission according to claim 1, further comprising comparison prohibition means for preventing the automatic transmission from operating.