JPH02180357A - Control device for electronically controlled automatic transmission - Google Patents

Abstract

PURPOSE:To sense failure certainly by sampling the deviation of inter-terminal electric amount measuring value of a linear solenoid from its target value, comparing the sum for the specified number of runs with the reference value, and judging if the case applies to shortcircuiting. CONSTITUTION:In case the two terminals of a linear solenoid 15 for hydraulic control has gone into shortcircuiting, a microprocessor 6 of an electronic control device 3 senses the size of ripples from difference in the monitor voltage ripple characteristic generated in a monitor circuit 11 at the current time. That is, sampling is made for the absolute value of the difference of a voltage value, which corresponds to the current value as target value to be output through a driver circuit 10, from the actual voltage value monitored by the monitor circuit 11, followed by determining the sum for a certain number of runs, and exceeding the reference value should result in a judgement that the trouble applies to inter-terminal shortcircuiting of the linear solenoid 15. Thus shortcircuiting trouble can be sensed certainly.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a control device for an electronically controlled automatic transmission, and more particularly to a detection device for detecting a show between the near solenoid terminals of the transmission.

(Prior Technology) Hydraulic actuators in conventional electronically controlled automatic transmissions include not only solenoid on/off types but also linear output types that continuously change hydraulic pressure according to the amount of current applied to the solenoid. There is something like that.

This linear output type uses current feedback control to always match the current value under a certain condition to the target value, in order to compensate for variations caused by various external factors that can be considered due to the characteristics of the application. are doing.

The variations caused by various external factors here include variations in the voltage that drives the solenoid, variations in the resistance value of the solenoid itself, the temperature of the oil in which the solenoid is immersed (oil temperature), and the self-heating of the solenoid. Changes in resistance value, etc.

In addition, in order to accurately feedback control the hydraulic pressure, it is necessary to connect both terminals of the solenoid to an electronic control device through electric current.In this respect, the linear output type is different from the conventional on/off type solenoid. It is different from the body earth type that is found in some parts of the world.

(Problem to be Solved by the Invention) As described above, when a short occurs between the eleven terminals of the automatic transmission's linear solenoid, it is difficult to detect the failure, and a countermeasure against such a short failure is desired.

SUMMARY OF THE INVENTION In view of the above circumstances, it is an object of the present invention to provide a control device for an electronically controlled automatic transmission that can accurately detect a short-circuit failure between terminals of a solenoid and perform fail-safe control thereof.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides an electronically controlled automatic transmission equipped with a linear solenoid that performs feedback control by an electronic control device. means for sampling the deviation between the target value and the actual measured value of the quantity of electricity; means for performing the sampling a predetermined number of times and calculating the sum of each sampling;
A means for comparing the sum with a reference value is provided, and based on the comparison result, it is determined whether or not there is a short circuit between the terminals of the linear solenoid.

(Operation and Effects of the Invention) According to the present invention, as described above, attention is paid to the electrical characteristics that the linear solenoid is not a mere resistance but a coil and has inductance, and The voltage value (average voltage value) detected by the detection resistor using current feedback control is the same in both cases, but the ripple characteristics are different, so by detecting this difference in ripple characteristics, it is possible to Short circuits can be detected. In other words, the voltage ripple characteristics are different between the normal state (see Figure 3) and the shorted state between the terminals of the linear solenoid (see Figure 4), and when the terminals are shorted, the inductance of the linear solenoid is The ripple value increases. In addition, as shown in Figure 3, this voltage has the characteristic of fluctuating around the target current value in the normal state, so the voltage corresponding to the target current value, here 0.
．． The magnitude of ripple can be detected by sampling and summing the absolute value of the difference between 9AX O, 9Ω-0, 81V and the voltage actually input. If the value of the ripple width detected in this way is larger than a certain reference value, a failure can be accurately detected by determining that there is a short circuit between the terminals of the solenoid.

As described above, when a failure is detected, appropriate measures can be taken using fail-safe control, the driver can be notified of the failure and the need for repair can be instructed, and diagnosis can be used to locate the failure location. You can also explore.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

Fig. 1 is an overall configuration diagram of an electronically controlled automatic transmission to which the present invention is applied, Fig. 2 is an interface circuit diagram of the linear solenoid of the transmission, and Fig. 3 is a monitor voltage characteristic diagram of the linear solenoid in normal conditions. , FIG. 4 is a monitor voltage characteristic diagram when a short circuit occurs between the terminals of the linear solenoid.

In FIG. 1, 1 is a throttle position sensor (hereinafter referred to as throttle sensor) that detects the throttle opening, 2 is a vehicle speed sensor, and 3 is an electronic control device. microcomputer 6, first shift solenoid drive circuit 7,
Second shift solenoid drive circuit 8, lock-up solenoid drive circuit 9, hydraulic control solenoid drive circuit 10
, a hydraulic control solenoid monitor circuit 11, and a failure warning device drive circuit 16. Also, 12 is the first
13 is a second shift solenoid,
14 is a lock-up solenoid, 15 is a hydraulic control solenoid, and 17 is a failure warning device, each of which is connected to the electronic control device 3.

In addition, in FIG. 2, the drive circuit IO of the hydraulic control solenoid 15 has a battery voltage B, a switching PNP
) Transistor Tr+, PNP transistor for overcurrent protection Tr1% NPN transistor TP3 that receives the signal from the microcomputer 6, capacitors C8 to C
s, resistors R, , Rs to R8, a flywheel diode D1, and a negative logic N07 circuit 16.

In addition, the monitor circuit 11 has a resistor Rt (combined resistance of resistor R1+ and resistor R2□) = R9, R1°, capacitor C
It is composed of diodes Dz, Ds, and diodes Dz and Ds.

Next, the operation of this circuit will be explained.

When a low level command signal is output from the mass/microcomputer 6, the signal is sent to the negative logic N07 circuit 16.
The signal is inverted to a high level signal, the base potential of the transistor Tr3 rises, and the transistor T is turned on. Then, the switching transistor T,,1
The base potential of is lowered and the transistor 'Ll is turned on, so that the hydraulic control solenoid 15 is energized from the pantry voltage B through the detection resistor R2. The energization state is monitored by the detection resistor R8, and the information is read into the microcomputer 6.

On the other hand, when the microcomputer 6 outputs an illumination level command signal, the signal is inverted to a Lo-level signal by the negative logic N07 circuit 16, and the base potential of the transistor Trs decreases, causing the transistor Tr3
is turned off. Then, the switching transistor T'
The base potential of r+ rises and the transistor TrI is turned off, thereby deactivating the hydraulic control solenoid 15. Its energization state is monitored by a detection resistor R8,
The information is read into the microcomputer 6.

In such a circuit configuration, it is difficult to detect a short circuit between the terminals of the hydraulic control solenoid 15. The reason for this is that the current is This is because feedback control is performed. In other words, the resistance value of the hydraulic control solenoid 15 is 2 to 5 Ω at -C, but even if this becomes 0 Ω due to a short between the terminals, the electronic control unit 6 cannot distinguish it from variations caused by external factors. First, this is because normal current feedback control is performed.

This point will be explained in more detail using FIG. 2.

In this figure, B is the battery voltage, 9-16V
eRI, which fluctuates within the range of 0.9Ω resistance for detection
±1% (1.8Ω parallel circuit).

Moreover, the variation in resistance of the hydraulic control solenoid 15 itself is in the range of 2 to 5 Ω, taking into account the variation between products and the variation in environmental temperature. And this solenoid 1
The operating current range of No. 5 is 0.3 to IA, and it is necessary to have the ability to adjust the current to a constant value, taking into account all the above-mentioned variations. Further, the current is adjusted by 300 Hz PWM (pulse width modulation) control by the microcomputer 6. Here, the minimum and maximum values of the PWM duty range to satisfy the above conditions are as follows.

The minimum duty range of PWM [Dmin is (0, 3
A/ (16V/2 + (0,22+0.9)xO,9
5Ω1)X100-5.7% Its maximum value Dmax is CI A/ (9V15 + (0,22+0.9)xl
, 05Ω)]X100 = 68.6% Therefore, the duty variable range is at least 5.7
~ The maximum is 68.6%, and in reality it is 3 to 75 with a margin.
Set as %.

Here, considering the case where a short circuit occurs between the terminals of the hydraulic control solenoid 15, the minimum value Dsin of the PWM duty range is (0, 3
A/ (16V/(0,22+0.9)xO, 95Ω)
X100-2.0% Its maximum value Dmax is (I A/ (9V/(0,22+0.9)xl, 05
Ω)X100-13.1%, and the duty variable range is 2.0 to 13.1%, which is approximately included in the above-mentioned normal duty variable range.

Therefore, even if the terminals of the hydraulic control solenoid 15 are torn, the current will be adjusted by normal current feedback control, and the microcomputer 6 will determine whether the terminals are correct from the monitored average current value. It is difficult to detect short-circuit failures during

In this way, even if a short circuit occurs between the terminals of the hydraulic control solenoid 15, it cannot be accurately detected, making it difficult to take appropriate measures such as fail-safe.

In addition, in the electronically controlled automatic transmission system described above, two shift solenoids 12 and 13 for speed change control attached to the hydraulic circuit in the T/M are locked up based on signals from the throttle sensor 1 and the vehicle speed sensor 2. (L
-up) The electronic control unit 3 controls the solenoid 14 and the hydraulic control solenoid 15 that controls the line pressure, which is the basis of the hydraulic circuit.
It is an off-type solenoid, and is a hydraulic control solenoid 15.
is a linear solenoid in which the oil pressure changes proportionally to the applied current.

The hydraulic control solenoid 15 adjusts the throttle pressure to 0 at a current value of 1 to 0.3 A output by the electronic control bag N3 based on the throttle opening information from the throttle sensor 1.
．． 5-4.5 to +r/-, the line pressure, which is proportional to the throttle pressure, is controlled. The drive circuit 10 and monitor circuit 11 of this hydraulic control solenoid 15 are as shown in FIG. 2, and are used to correct variations caused by external factors such as those described above (variations in battery voltage, variations in solenoid resistance value, etc.). Therefore, current feedback control is configured. Therefore, both terminals of the hydraulic control solenoid 15 are connected to the electronic control device 3.

Therefore, if the terminals of this hydraulic control solenoid 15 are short-circuited, the current flowing through the solenoid 15 becomes zero, the throttle pressure becomes 5 kg/cd, and the line pressure is even higher than the normal maximum pressure. It becomes pressure. If this condition is left unaddressed, the automatic transmission's shift control will be performed using this high line pressure, which will cause a very large shock when shifting, and also cause secondary failures due to the high oil pressure inside the T/M. Therefore, it is necessary to reliably detect this short-circuit failure between terminals, perform fail-safe control, and provide a failure warning.

The present invention is a hydraulic control solenoid (linear solenoid)
When a short-circuit failure occurs between the terminals of No. 15, the short-circuit failure between the terminals is detected by paying attention to the difference in the ripple characteristics of the monitor voltage at that time and detecting the magnitude of the ripple.

Regarding this point, below, we will compare the monitored voltage when the linear solenoid 15 is energized as shown in Fig. 3 with the monitored voltage when the terminals of the linear solenoid 15 are shorted as shown in Fig. 4. explain. Note that here, the voltage at point a on the output side of the monitor circuit 11 is monitored.

In the normal state, as shown in FIG. 3, the voltage value corresponding to the target current value, here 0.9 Ax
Sample the absolute value of the difference between o, 9Ω = 0.81V and the voltage actually applied manually, and calculate the total by summing it a certain number of times. If the total is larger than a certain reference value, the linear solenoid 15 By determining that the fault is a short-circuit fault between terminals, the short-circuit fault can be accurately detected.

That is, as shown in FIG. 3, the limbus in the normal state is about 10 mV due to the inductance of the linear solenoid 15
On the other hand, in the case of a short-circuit failure, the inductance of the linear solenoid 15 disappears, and the ripple becomes a sawtooth wave (30011z) and reaches about 60 mV.

In this embodiment, the sampling time is every 4 m3, the total number of samplings (sampling number) is 400, and a case where the total A/D value is 1000 or more is regarded as an inter-terminal seat failure.

Here, the A/D value is an A/D value of 10 bits (1024) based on 5■ in the microcomputer 6.
This is the result of the conversion, A / D (total of a 10
00 indicates 4.88V.

FIG. 5 shows experimental data, showing the sum of A/D values in a normal state and a short-circuited state.

As is clear from this figure, the total A/D value is normally around 400, and in the seated state it is around 1100 to 1350.
Therefore, by setting the reference value to 1000, failures can be reliably detected.

Hereinafter, a procedure for detecting a failure when a short circuit occurs between the terminals of the linear solenoid according to the present invention will be explained using FIG.

First, it is determined whether the target A/D value is stable (step 2).

As a result, if the A/D value is stable, the target A/D value is
Determine whether or not the D value is greater than or equal to the reference value 9E (0.85A>) (Step 2).

As a result, if the A/D value is greater than or equal to the reference value, the difference between the monitor (sampled) AZD value and the target A/D value is determined (step 2).

Next, in order to remove noise, it is determined whether the difference in A/D values is 15 or more (step 2).

Next, it is determined whether the number of manual A/D operations is less than 45. In other words, the waiting time is set to 0.2 seconds (step ■).

As a result, if the number of A/D inputs is not less than 45, the sum of the differences in A/D values - the sum of the differences up to the previous time + the current A/D
Let it be the difference in D value (step ■).

Next, it is determined whether or not the number of A/D inputs has been increased to 400 (step 2).

As a result, when the number of A/D inputs is 400, it is determined whether the sum of the differences in A/D values is less than the reference value too (step 2).

As a result, if the sum of the differences in A/D values is not less than the reference value 1000, a detection flag is set as a seat failure between the linear solenoid terminals (step 2).

The current target A/D value is stored as comparison data (step 0).

In step (3), the sum of the differences in A/D values is the reference value 1.
If it is less than 000, the data of the sum of the differences in A/D values is cleared (step 2).

Next, after clearing the number of manual inputs of the A/D, proceed to step @) and step 0.

FIG. 7 is a diagram showing a first example of application of the present invention to a hydraulic control device for an automatic transmission.

As shown in the figure, the hydraulic pressure finely adjusted by the linear solenoid valve 23 is applied to the orifice control valve 3.
Supplied for adjusting the valve position of 1. That is, the solenoid modulator valve 29 receives the oil pressure regulated by a primary regulator valve (not shown) and adjusts the oil pressure for each solenoid. The hydraulic pressure adjusted by the solenoid modulator valve 29 is supplied to the boat a of the linear solenoid valve 23. The linear solenoid valve 23 is linearly controlled by a signal sent from a control device (not shown), regulates the hydraulic pressure supplied to the boat a, and sends it to the boat b.

Subsequently, the hydraulic pressure from the boat b is supplied to port b+ of the solenoid relay valve 26. The solenoid relay valve 26 can take two positions, a right half position and a left half position. In the right half position, the boat b+ is connected to the boat c, and the valve of the orifice control valve 31 is connected. Hydraulic pressure is supplied to boat e at one end. On the other hand, in the case of the left half position, the boat b1 is connected to the boat d, and the hydraulic pressure finely adjusted by the solenoid relay valve 26 is supplied to the lockup actuating device, and is used to control the lockup on and off. Ru.

The orifice control valve 31 is finely adjusted by the linear solenoid valve 23, and the valve position is adjusted by the balance between the hydraulic pressure supplied to the boat e and the biasing force of the spring 32. The hydraulic pressure from the manual valve 22 is supplied to the orifice control valve 31 via the boat f, and is supplied to the forward clutch CI via the boat g in the left half position and via the boats g and h in the right half position. sent to.

Therefore, as the oil pressure is supplied from the linear solenoid valve 23, the valve of the orifice control valve 31 gradually descends, at first a small amount of oil flows through port 1-g, and later a large amount of oil flows through port 1-g. , h to the forward clutch CI,
The shock when changing gears is reduced. In addition,
Oil from the manual valve 22 passes through the orifice control pulp 31 as well as through the throttle 34 and check valve 3.
It is connected to the forward clutch CI via a 5-diaphragm 36.

Due to the action of the throttle 36 with the check valve 35, the amount of oil flowing to the forward clutch CI during draining can be made larger than when oil is being supplied.

By the way, as mentioned above, the solenoid relay valve 26 distributes the hydraulic pressure from the linear solenoid valve 23 for adjusting the valve position of the orifice control pulp 31 or for controlling the lock-up actuating device. Therefore, it has two positions, a right half position and a left half position. Therefore, the second coast brake B and maintenance oil pressure are applied to the boat l at one end of the solenoid relay pulp 26 from the boat 1+ of the 1-2 shift valve 27, and the 1-2 shift pressure is transferred to the boat j at the other end of the solenoid relay pulp 26. The second brake B2 engagement hydraulic pressure is supplied from the boat 11 of the valve 27. Further, a spring 33 is disposed on the end face of the valve on the boat i side, and urges the valve downward.

Here, in the 1st speed of the D+ 2nd and L ranges, neither the second coast brake B nor the second brake B is engaged, so the boat 1. j
Neither oil pressure is supplied, and the above solenoid relay pulp 2
6 is placed in the right half position only by the biasing force of the spring 33.

Next, when it comes to 2nd gear or higher in D, 2nd, and L ranges,
Second brake B2 is engaged and hydraulic pressure is supplied to boat j, and in 2nd and L ranges, not only second brake B2 but also second coast brake B is engaged, and hydraulic pressure is also supplied to boat l. . by the way,
Boat 1. When hydraulic pressure is supplied to both the manual pulp 22 and the 1-2 shift valve 2, the re-extraction pressure is
7 or 2-3 shift valve 28 and are at the same pressure, both end faces of the solenoid relay pulp 26 are pressed with the same force. Therefore, the solenoid relay pulp 26 has a spring It assumes the right half position with only the urging force of 33.

That is, 2nd from each range of N, R, and P.

When shifting to the L speed of the L range, the solenoid relay pulp 26 always takes the right half position and supplies the hydraulic pressure of the linear solenoid valve 23 to the orifice control pulp 31, thereby reducing shift stagnation. .

Also, when moving to 2nd speed or higher in D, 20d, and L ranges,
Since it is necessary to activate the lock-up mechanism,
The solenoid relay pulp 26 is in the left half position and supplies the hydraulic pressure of the linear solenoid valve 23 to the lock-up control valve 24 and the lock-up relay valve 25. Note that it is necessary to release the lock-up when starting in 2nd gear in the 2nd range, but as mentioned above,
d. In the second gear of the L range, the solenoid relay pulp 26 assumes the right half position only by the biasing force of the spring 33, so the hydraulic pressure of the linear solenoid valve 23 is controlled by the lock-up control pulp 24 and the lock-up relay valve 25.
It is not supplied to any of the following.

In the hydraulic control system configured as described above, the present invention operates by connecting the electronic control device 3 to the solenoid of the near solenoid valve 23 described above. Thereby,
As described above, it is possible to reliably detect a short-circuit failure between the solenoid terminals of the near solenoid pulp 23.

FIG. 8 is a diagram showing a second example of application of the present invention to a hydraulic control device for an automatic transmission.

As shown in this figure, overdrive direct clutch C0 receives oil supply from boat a of 3-4 shift valve 55, and overdrive brake B receives oil supply from boat b of 3-4 shift valve 55. It is designed to receive. The 3-4 shift pulp 55 takes two positions by turning on and off the solenoid valve 57, and receives the oil pressure regulated by the primary regulator valve 52 at the boat a and the boat b. selectively supplied to That is, in 1st, 2nd, and 3rd speeds, the solenoid valve 57 is in an on state, and is drained to remove the hydraulic pressure at d), and the 3-4 shift valve 55 is placed in the right half position. . Therefore, the hydraulic pressure from the primary regulator valve 52 is sent to the overdrive direct clutch C(1).

When the fourth speed is reached, the solenoid valve 57 is turned off, oil pressure is supplied to the boat d, the 3-4 shift valve 55 is placed in the left half position, and the oil pressure from the primary regulator valve 52 is applied to the overdrive brake B0.
sent to.

Conversely, during a 4-3 downshift, the oil pressure from the primary regulator valve 52 that was being sent to the overdrive brake B0 is now supplied to the overdrive direct clutch Co by switching the 3-4 shift valve 55. .

In addition, a throttle 61 and a throttle with reverse valve 62 are arranged in the oil passage for engaging the overdrive direct clutch C0 extending from the boat a, and on the overdrive direct clutch C0 side from these, the overdrive direct clutch The C3 accumulator 54 is branch-connected. The Akiemulator 54 for overdrive direct clutch C0 includes overdrive direct clutch C,
The oil enters the upper chamber of the overdrive direct clutch C0 accumulator 54 via the boat e, and the piston 63
is pushed down against the spring 64. Then, the overdrive direct clutch C0 is only engaged when a constant pressure is obtained.

On the other hand, overdrive brake B0 extending from boat b
A throttle 65 and a throttle 66 with a check valve are provided in the engagement oil passage, and the overdrive brake rotor 0
An overdrive brake B0 achiemulator 56 is branch-connected to the side. The overdrive brake low 0
Accumulator 56 is for overdrive brake B
This oil is to prevent sudden oil supply to the overdrive brake B and the overdrive brake B through the boat f.
enters the lower chamber of the accumulator 56 and pushes up the piston 67 against the spring 68. Then, the overdrive brake B0 is only engaged when a constant pressure is obtained.

Here, each of the accumulators 54, 56 is provided with boats g and h on the back pressure side of the piston (>3.67).The boats g are connected to the cut-off valve 60.
is connected to the boat i, and the cut-off valve 6 is connected to the boat i.
Hydraulic pressure is supplied or stopped depending on the 0 position. Also,
Boat h is connected to boat j of an accumulator control valve 58, and hydraulic pressure is supplied or stopped depending on the position of the accumulator control valve 58. The hydraulic pressure supplied to these boats g and h provides back pressure to the accumulators 54 and 56, thereby acting as resistance to the operation of the accumulators 54 and 56, resulting in overdrive direct clutch C0 and overdrive brake B0. It acts to speed up the engagement and disengagement.

The back pressure is controlled as follows.

The hydraulic pressure regulated by the solenoid modulator valve 59 is applied to the hole 1-k of the accumulator control valve 58.
and the accumulator control valve 58
Since it is normally in the left half position, it is supplied to the sound pressure side boat h of the overdrive brake B0 achievator 56 via the boat j, and is also supplied to the boat l of the cut-off valve 60 via the boat J.

By the way, the cut-off valve 60 has two positions depending on the oil pressure supplied from the throttle valve 53, for example, depending on the acceleration/deceleration state of the vehicle. That is, when the accelerator is turned on, hydraulic pressure is supplied from the boat m of the throttle valve 53 to the boat n+p of the cutoff valve 60, and the cutoff valve 60
takes the right half position. At this time, boat l and boat l
When the overdrive direct clutch C0 is cut off, the back pressure applied to the port g of the accumulator 54 for the overdrive direct clutch C0 disappears, and the engagement of the overdrive direct clutch C0 becomes delayed. That is, in the case of a 4-3 downshift, for example a 4-3 kickdown, with the accelerator on, the engagement of the overdrive direct clutch C0 is delayed and the shock at the time of downshifting is reduced.

Further, when the accelerator is turned off, the supply of hydraulic pressure from port m of the throttle valve 53 to ports n and p of the cut-off valve 60 is stopped, and the oil in the port ntp is discharged. Therefore, the cut-off valve 60
takes the left half position, and ports l and port i are communicated, so back pressure is applied to port g of the accumulator 54 for overdrive direct clutch Co, and as a result, overdrive direct clutch C0 is not engaged. It gets faster. That is, in the case of a 4-3 downshift with the accelerator off, for example a 4-3 manual downshift, the overdrive direct clutch C0 is engaged quickly, resulting in a good response during downshifting.

As described above, the cut-off valve 60 is switched by turning on and off the accelerator, and accordingly, the overdrive direct clutch C0 overdrive emulator 5 is switched.
The supply of back pressure applied to 4 is controlled to perform downshift control according to the driving conditions, but the 4 shifts down from 4th to 3rd gear while naturally reducing speed.
-3 When coasting down, it is desirable to reduce the shock in the same way as when kicking down.
At the time of the 4-3 coast down, the back pressure of the overdrive direct clutch C0 Achiemulator 54 is removed.

To this end, the linear solenoid valve 51, which operates during 4-3 coastdown, is used to control the accumulator control pulp 58. That is, the port r of the linear solenoid valve 51 is connected to the port q of the S-accumulator control valve 58, and when the linear solenoid valve 51 is activated and hydraulic pressure is supplied to the port q, the accumulator control valve 58 is in the right-hand position. (Move to 1- and Bo)
J is cut off. As a result, the back pressure formed on the boat j side can be forcibly removed.

Note that the cant-off valve 60 is provided with a port n and a port p that are branched from one oil passage, and this is for providing a snap action to the cut-off valve 60. ! In order to form a positive snap action, the pressure receiving area of the land 69 of the spool valve is made larger than the pressure receiving area of the land 70. Therefore, when the accelerator is turned on, oil is initially supplied from port n and port p.

At that time, oil supplied from port n pushes land 69 downward, but oil supplied from port p pushes lands 69 and 7
Since the spool valve is pressurized and the spool valve is urged upward from the difference in the pressure receiving area, the speed at which the spool valve descends is slow, and if the supply of oil from port P stops during the descent, the spool valve The force that urges the valve upward is eliminated, and the oil supplied from port n exclusively pushes the land 69 downward, so that the downward speed of the spool valve becomes faster.

Conversely, when the spool valve rises, a similar snap action is applied, and the speed increases in the latter half of the rise.

In this way, reliable switching operation can be obtained when descending and ascending, so the above-mentioned overdrive direct clutch C
- Back pressure can be quickly supplied and stopped to the Akiemulator 54.

In the hydraulic control system configured as described above, the present invention operates by connecting the electronic side 'a device 3 to the solenoid of the near solenoid valve 51 described above. Thereby, a short-circuit failure between the terminals of the solenoid of the linear solenoid valve 51 can be reliably detected.

As a result, when a short-circuit failure is detected, the system shifts to a mode (so-called emergency mode) that allows manual transmission driving by operating the shift lever, performs fail-safe control, and displays a failure warning installed on the driver's instrument panel. The device 17 can be activated to inform the driver of the malfunction and alert him to the need for repairs.

In addition, by storing the fact that this short-circuit failure has occurred in the memory of the electronic control unit, it is possible to quickly search for the failure location by reading it out with a diagnostic system tester at a dealer, etc. It is possible to improve serviceability.

Note that the present invention is not limited to the above embodiments,
Various modifications are possible based on the spirit of the present invention, and these are not excluded from the scope of the present invention.

[Brief explanation of the drawing]

Fig. 1 is an overall configuration diagram of an electronically controlled automatic transmission to which the present invention is applied, Fig. 2 is an interface circuit diagram of the linear solenoid of the transmission, and Fig. 3 is a monitor voltage characteristic diagram of the linear solenoid in normal conditions. , Figure 4 is a monitor voltage characteristic diagram when the terminals of the linear solenoid are short-circuited, and Figure 5
The figure shows experimental data when the linear solenoid of the present invention is shunted between terminals, Figure 6 is a failure detection flowchart when the linear solenoid is short-circuited between terminals, and Figure 7 is a diagram showing the specific automatic operation of the present invention. FIG. 8 is a diagram showing a first example of application to a hydraulic control device for a transmission, and FIG. 8 is a diagram showing a second example of application to a hydraulic control device for an automatic transmission. 1...Throttle sensor, 2...Vehicle speed sensor, 3.
...Electronic control unit, 4.5...Interface circuit,
6... Microcomputer, 7... First shift solenoid drive circuit, 8... Second shift solenoid drive circuit, 9... Lock-up solenoid drive circuit,
10... Solenoid drive circuit for hydraulic control, 11...
Monitor circuit, 12...first shift solenoid, 13
...Second shift solenoid, 14...Lock-up solenoid, 15...Hydraulic pressure control solenoid (linear solenoid), 16...Failure warning device drive circuit, 1
7... Failure warning device, 23, 51... Linear solenoid valve. Patent applicant: Aisin ADA Co., Ltd. Agent: Patent attorney: Mamoru Shimizu (1 other person) Figure 3 Figure 3

Claims (3)

[Claims] (1) In an electronically controlled automatic transmission equipped with a linear solenoid that performs feedback control by an electronic control device, means for sampling the deviation between the target value of the amount of electricity between the terminals of the linear solenoid and the measured value of the actual amount of electricity. and means for performing the sampling a predetermined number of times to obtain the total sum of each sampling, and means for comparing the sum with a reference value, and based on the comparison result, it is determined whether or not there is a short between the terminals of the linear solenoid. A control device for an electronically controlled automatic transmission characterized by: (2) The control device for an electronically controlled automatic transmission according to claim 1, wherein the target value is set after transition to a stable state. (3) The control device for an electronically controlled automatic transmission according to claim 1, wherein the determination is not made when the deviation exceeds a set value.