JP2007292186A - Friction fastening element interference detecting device for automatic transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a friction fastening element interference detecting device for an automatic transmission having simple construction for precisely detecting the engaging interference of a friction fastening element. <P>SOLUTION: An AT control unit 24 calculates the deceleration of a vehicle from the detection result of an output shaft rotation sensor 38 and determines that the engaging interference occurs when the deceleration is between predetermined values g1, g2 and an oil temperature detected by an oil temperature sensor 36 rises a predetermined value or more in a predetermined time. Thus, it can accurately detect the occurrence of the engaging interference in accordance with oil temperature rise even when it cannot accurately determine whether the engaging interference occurs only from the deceleration. Since it detects whether the engaging interference occurs while using a vehicle speed and the oil temperature originally used for controlling the automatic transmission, it can detect the engaging interference of the friction fastening element while reducing cost without the need for additional hydraulic pressure sensors to detect the engaging interference. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a frictional engagement element interference detection device for detecting engagement interference between a clutch and a brake in a stepped automatic transmission.

Conventionally, a stepped automatic transmission includes a predetermined number of frictional engagement elements, a hydraulic circuit provided for each frictional engagement element, and a valve for switching whether or not to supply hydraulic pressure to the frictional engagement element through the hydraulic circuit. And a desired gear stage is obtained by switching a pattern of a frictional engagement element that supplies hydraulic pressure by a valve and fastening a predetermined frictional engagement element.
However, when hydraulic pressure is supplied to a frictional engagement element other than a predetermined pattern due to a failure of the valve or the like, the frictional engagement element may interfere with engagement.
When this engagement interference occurs, there is a risk that the frictional engagement element on the side where the engagement capacity of the frictional engagement element involved in the engagement is weaker will slip and the acceleration force of the vehicle will be dulled, or that the automatic transmission will malfunction.

In order to detect this engagement interference, for example, in the one described in Patent Document 1, a hydraulic switch is provided in each hydraulic circuit of the frictional engagement element, and the hydraulic pressure is supplied when the hydraulic pressure is not to be supplied. Whether or not it is detected.
In Patent Document 2, the fact that the vehicle decelerates at the time of frictional engagement of the frictional engagement element is detected as the occurrence of engagement interference when the vehicle deceleration exceeds a predetermined value.
JP 2001-59570 A Japanese Patent Laid-Open No. 06-109129

However, since a hydraulic switch is provided in the hydraulic circuit to detect the engagement interference of the frictional engagement element, the hydraulic switch is mounted in the oil. Even though the hydraulic pressure is not supplied to the fastening element, the hydraulic switch may be turned on to erroneously determine that engagement interference has occurred.
Further, it is necessary to attach a hydraulic switch to each hydraulic circuit connected to the frictional engagement element, which increases the cost.

Further, in the case where the engagement interference of the frictional engagement element is detected based only on the change in the deceleration of the vehicle, the engagement capacity of the frictional engagement element involved in the engagement interference is small when the engagement interference occurs. Since slippage occurs, the gear ratio apparently shows a normal gear ratio, and because slippage occurs in the frictional engagement element on the side with a smaller engagement capacity, the vehicle deceleration may not change significantly.
In such a case, there is a problem that it is difficult to detect the engagement interference only by the deceleration and the gear ratio of the vehicle.

  SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a frictional engagement element interference detection device in an automatic transmission that can accurately detect engagement interference of frictional engagement elements with a simple configuration. .

  The present invention is an automatic transmission that includes a plurality of frictional engagement elements and obtains a desired gear stage by fastening the frictional engagement elements by supplying hydraulic pressure to a predetermined combination of frictional engagement elements. In a frictional engagement element engagement interference detection device in an automatic transmission having an engagement interference detection means for detecting whether engagement interference is occurring due to engagement of the frictional engagement elements of the vehicle. Detection means and oil temperature rise detection means for detecting whether or not the temperature characteristic of the oil in the automatic transmission has changed in the upward direction, and the engagement interference detection means detects the vehicle deceleration by the deceleration detection means. The oil temperature characteristic is changed in the increasing direction by the oil temperature increase detecting means after it is detected that the vehicle speed is equal to or higher than the first predetermined value and the vehicle speed is equal to or higher than the first predetermined value. thing When it is detected, and shall be detected as the engagement interference occurring.

  According to the present invention, when engagement interference occurs, the friction engagement element on the side with the smaller engagement capacity slips, and the slip increases the temperature of the oil in the automatic transmission. By detecting that the engagement interference is occurring when the oil temperature is larger than the value g1 and the oil temperature changes in the upward direction, the engagement interference can be detected with higher accuracy. Further, since the detection can be performed based on the vehicle speed and the oil temperature, it is not necessary to provide a hydraulic switch or the like for each hydraulic system of each friction engagement element, and the engagement interference can be detected at a low cost with a simple configuration.

Next, embodiments of the present invention will be described by way of examples.
First, the first embodiment will be described.
FIG. 1 shows a gear train of an automatic transmission to which the frictional engagement element engagement interference detection device according to this embodiment is applied.
The engine output shaft E, the transmission input shaft I, and the transmission output shaft O are arranged coaxially, and a torque converter T / C is interposed between the engine output shaft E and the transmission input shaft I. The transmission input shaft I and the transmission A first planetary gear set G1 and a second planetary gear set G2 are interposed between the output shafts O.
The first planetary gear set G1 is a simple planetary gear set including a first pinion P1, a first carrier C1, a first sun gear S1, and a first ring gear R1, and the second planetary gear set G2 is a second pinion P2 and a second pinion P2. This is a simple planetary gear set including a carrier C2, a second sun gear S2, and a second ring gear R2.

The transmission input shaft I and the second sun gear S2 are directly connected. A reverse clutch R / C is provided in the middle of the member connecting the transmission input shaft I and the first sun gear S1, and the member can be fixed to the case. 2-4 brake 2-4 / B with a multi-plate brake structure is provided.
A high clutch H / C is provided in the middle of the member connecting the transmission input shaft I and the first carrier C1.
A low clutch L / C is provided in the middle of the member connecting the first carrier C1 and the second ring gear R2, and a low and reverse brake L & R / B with a multi-plate brake structure that allows the member to be fixed to the case. The one-way clutch OWC is provided in parallel with the low & reverse brake L & R / B.

The first ring gear R1 and the second carrier C2 are directly connected, and the transmission output shaft O is connected to the second carrier C2.
The high clutch H / C, the low & reverse brake L & R / B, the low clutch L / C, the 2-4 brake 2-4 / B, and the reverse clutch R / C are friction engagement elements. (Hereinafter, each clutch and brake are collectively referred to as a friction engagement element.)

FIG. 2 is a diagram (engagement is indicated by a circle) showing an engagement logic table at each gear stage in a reverse range (hereinafter, R range) and a drive range (hereinafter, D range).
During the R range, the reverse clutch R / C and the low & reverse brake L & R / B are engaged. The low clutch L / C is engaged when the D range is the first speed, the low clutch L / C and the 2-4 brake 2-4 / B are engaged when the D range is the second speed, and the low clutch L / C is high when the D range is the third speed. The clutch H / C is engaged, and the high clutch H / C and the 2-4 brake 2-4 / B are engaged at the fourth speed in the D range.
Note that the low clutch L / C and the low & reverse brake L & R / B are engaged at the first speed in the HOLD mode in the low range (during the first speed embedment).

FIG. 3 is a diagram showing a shift control system of the automatic transmission.
A D range pressure oil passage 3, an R range pressure oil passage 4, and a line pressure oil passage 1 through which the line pressure passes are connected to the manual valve 2.
The manual valve 2 is a valve that can be switched by a select operation. In the D range, the line pressure oil passage 1 and the D range pressure oil passage 3 are connected to supply the D range pressure oil to the D range pressure oil passage 3, and in the R range The line pressure oil passage 1 and the R range pressure oil passage 4 are connected, and the R range pressure is supplied to the R range pressure oil passage 4.

A pilot pressure oil path 6 is connected to the line pressure oil path 1 via a pilot valve 5.
The pilot valve 5 controls to reduce the line pressure from the line pressure oil passage 1 to a constant pilot pressure.
The D range pressure oil passage 3 is connected to the low clutch L / C via the low clutch amplifier valve 8 and the low clutch pressure oil passage 9.
The low clutch amplifier valve 8 generates a low clutch pressure from the D range pressure based on the control pressure supplied from the duty control type low clutch solenoid 7, and supplies the low clutch pressure to the low clutch L / C.

The D-range pressure oil passage 3 is connected to the high clutch H / C via a high clutch amplifier valve 11 and a high clutch pressure oil passage 12.
The high clutch amplifier valve 11 generates a high clutch pressure from the D range pressure based on the control pressure supplied from the duty control type high clutch solenoid 10 and supplies it to the high clutch H / C.

The D range pressure oil passage 3 is connected to the 2-4 brake 2 through the 2-4 brake first failsafe valve 25 (details will be described later), the 2-4 brake amplifier valve 15 and the 2-4 brake pressure oil passage 16. 4 / B.
The 2-4 brake amplifier valve 15 2-4 from the D range pressure supplied through the 2-4 brake first failsafe valve 25 based on the control pressure supplied from the duty control type 2-4 brake solenoid 14. Brake pressure is generated and supplied to the 2-4 brake 2-4 / B.

A low & reverse brake first failsafe valve 27 and a low & reverse brake second failsafe valve 28 (details will be described later) are connected in parallel to the line pressure oil passage 1, and the low & reverse brake first failsafe valve is connected. 27 and the low & reverse brake second failsafe valve 28 are supplied to the low & reverse brake L & R / B via the low & reverse brake amplifier valve 19 and the low & reverse brake pressure oil passage 20. ing.
The low & reverse brake amplifier valve 19 generates low & reverse brake pressure from the line pressure based on the control pressure supplied from the duty control type low & reverse brake solenoid 18 and supplies it to the low & reverse brake L & R / B. .

The line pressure is switched between high pressure and low pressure by an ON / OFF type pressure control solenoid (PL SOL) 22.
A duty control type lockup solenoid 23 is provided for controlling the hydraulic pressure for engaging or releasing the lockup clutch provided in the torque converter T / C.
Each of these solenoids 7, 10, 14, 18, 22, 23 is operated by a solenoid drive current output from an AT control unit (ATCU) 24.
The AT control unit 24 performs various control calculation processes including shift control based on the input information, and determines the solenoid drive current to be output to each solenoid based on the processing result.
The control calculation processing by the AT control unit 24 will be described later.

The 2-4 brake first failsafe valve 25 includes a fail pressure P _FP (hydraulic pressure equal to the maximum pressure of the high clutch H / C that is engaged at a high speed of the drive range) that always acts on one end of the spool, and a spool. This is a hydraulically operated valve having a low clutch pressure P _{L / C} acting on the other end side of the cylinder as an operation signal pressure.
The low clutch pressure P _{L / C} acting on the other end of the spool of the 2-4 brake first failsafe valve 25 is supplied from the 2-4 brake second failsafe valve 26.

2-4 brake second fail-safe valve 26, the hydraulic pressure to the fail-pressure pressure P _FP acting constantly on one end of the spool, the high clutch pressure P _{H / C} and the operating signal pressure acting on the other end of the spool Actuating valve.
When the low clutch pressure and the high clutch pressure are generated simultaneously at the third speed in the D range, the low clutch pressure P _{L / C} is 2 by applying the high clutch pressure PH _{/ C} to the 2-4 brake second failsafe valve 26. The -4 brake is applied to the first fail-safe valve 25, thereby draining the D-range pressure so that the 2-4 brake pressure is not supplied to the 2-4 brake 2-4 / B.

Low & reverse brake first fail-safe valve 27, the low & reverse brake second fail-safe valve 28 has a fail-pressure pressure P _FP acting constantly on one end of the spool, the high clutch pressure acting to the other end side of the spool This is a hydraulically operated valve that uses PH _{/ C} and 2-4 brake pressure _{P2-4 / B} as operation signal pressures.
By forcibly draining the line pressure in the D range 2, 3, 4th speed when either one or both of the high clutch pressure PH _{/ C} and 2-4 brake pressure P _{2-4 / B} is generated Do not supply low & reverse brake pressure to low & reverse brake L & R / B.

FIG. 4 is a block diagram showing an electronic control system of the automatic transmission.
The throttle opening TH and the engine speed Ne are input to the AT control unit 24 from an engine control unit (ECU) 29 through serial communication, and torque-down communication is performed between the control units 24 and 29.
The AT control unit 24 includes a turbine rotation sensor 30 provided in the power train of the automatic transmission and detecting the rotation speed of the transmission input shaft I as the turbine rotation speed Nt, and the rotation speed of the transmission output shaft O as the output shaft rotation speed. The detection result from the output shaft rotation sensor 38 detected as No is input.

Note that the vehicle speed of the vehicle can be calculated from the output shaft rotational speed No, which is the rotational speed of the transmission output shaft O.
The AT control unit 24 receives a range signal from the inhibitor switch 31, a hold switch signal from the hold switch 32, and a brake switch signal from the brake switch 33 that detects foot brake operation.
Further, an oil temperature signal indicating the temperature of oil accumulated in the automatic transmission is input from the oil temperature sensor 36 to the AT control unit 24.

  From the AT control unit 24, solenoid drive current is output to each solenoid 7, 10, 14, 18, 22, 23, and a speed display signal is sent to a speedometer 37 provided on the instrument panel. Is output.

Next, a procedure for detecting the engagement interference of the frictional engagement elements performed in the AT control unit 24 will be described.
FIG. 5 shows the flow of the engagement interference detection process.
This process is executed when the foot brake operation of the vehicle is released (when the brake switch 33 is OFF).
In step 100, the deceleration of the vehicle is calculated from the output shaft rotational speed No. In step 101, the oil temperature in the automatic transmission is detected by the oil temperature sensor 36.
The AT control unit 24 constantly monitors the oil temperature detected by the oil temperature sensor 36 and stores changes in the oil temperature.

In step 102, it is determined whether the vehicle deceleration calculated in step 100 is equal to or greater than a predetermined value g1 (first predetermined value). If the calculated deceleration is equal to or greater than the predetermined value g1, friction engagement is performed. Proceeding to step 103 on the assumption that the vehicle has been decelerated due to the interference of the elements. (The greater the deceleration, the stronger the braking force (deceleration))
On the other hand, if the calculated deceleration is less than the predetermined value g1, it is determined that no engagement interference has occurred, and the process returns to step 100 and the above-described processing is repeated.

In step 103, it is determined whether the vehicle deceleration calculated in step 100 is equal to or greater than a predetermined value g2 (second predetermined value). If the calculated deceleration is equal to or greater than the predetermined value g2, step 103 is performed. Proceed to 104.
On the other hand, if the calculated deceleration is less than the predetermined value g2, the routine proceeds to step 106.

In step 104, it is determined that engagement interference has occurred in the frictional engagement element, and in step 105, fail-safe control is performed.
The fail-safe control may be any control that avoids the engagement interference state of the frictional engagement elements. For example, by giving a neutral instruction, all the frictional engagement elements are released or engagement interference occurs. Running the vehicle without using the clutch or brake.

If it is determined in step 103 that the deceleration is less than the predetermined value g2, whether or not a shift has been executed within a predetermined time after calculating the deceleration in step 100 of the current process in step 106. Judging.
If a shift has been executed, the routine proceeds to step 107, where the current shift stage is recorded.
Here, since the engagement state of the frictional engagement element is switched at the time of shifting, engagement interference is likely to occur after the end of shifting. (For example, if the frictional engagement element that you want to switch from the engaged state to the released state does not enter the released state)

Therefore, if there is a possibility that the engagement interference has occurred within a predetermined time after the execution of the shift, it is possible to record which clutch or brake in the process in step 105 described later by recording the current shift stage in step 107. It is possible to use a material that narrows down whether engagement interference has occurred.
On the other hand, if it is determined in step 106 that no shift has been executed within a predetermined time, the routine proceeds to step 108.

In step 108, by referring to the oil temperature detected by the oil temperature sensor 36, the oil temperature rises by a predetermined value or more within a predetermined period after it is once determined that the deceleration is the predetermined value g1 or more in step 102. Determine if you did.
If it is determined that the oil temperature has increased by a predetermined value or more, the routine proceeds to step 104 where it is determined that engagement interference has occurred.
On the other hand, if the oil temperature has not risen by a predetermined value or more, it is determined that no engagement interference has occurred, and the process returns to step 100 and the above processing is repeated.

Here, when the engagement interference occurs, the clutch or brake having a small capacity among the clutches and brakes involved in the engagement interference slips.
The slippage of the clutch and brake generates heat, and the oil temperature in the automatic transmission rises.
Further, when slippage occurs in the clutch or the brake, for example, the oil temperature rises faster than the rise in the oil temperature caused by the heat generated by the torque converter during sports running.
Therefore, when the oil temperature rise above a predetermined value occurs within a predetermined time, the oil temperature rise is caused by slipping of the frictional engagement element on the smaller fastening capacity side due to the interference of the frictional engagement element. Therefore, it can be determined that engagement interference has occurred.
In this embodiment, steps 102 to 104 constitute the engagement interference detection means in the present invention, and step 100 constitutes the deceleration detection means in the present invention. Steps 101 and 108 constitute oil temperature rise detection means in the present invention.

The present embodiment is configured as described above. When the vehicle deceleration is between the predetermined values g1 and g2, engagement interference occurs when the oil temperature rises above the predetermined value within a predetermined period. Even if it is not possible to accurately determine whether engagement interference is occurring only by deceleration, it is possible to accurately detect the occurrence of engagement interference by detecting a rise in oil temperature. Can do.
Also, when slippage occurs in the clutch or brake due to the interference of the frictional engagement elements, the oil temperature rises quickly, so it is engaged when the oil temperature rises above a predetermined value within a predetermined time. By determining that the interference is occurring, for example, when the oil temperature rises due to sports driving or the like, it is not erroneously determined that the engagement interference has occurred, and the detection of the engagement interference is prevented. The accuracy can be further improved.
In order to detect whether or not engagement interference has occurred using the vehicle speed and oil temperature originally used for controlling the automatic transmission, a new hydraulic sensor or the like is additionally provided for detection of engagement interference. There is no need to detect the engagement interference of the frictional engagement elements while reducing the cost. (Effects corresponding to claims 1 and 4 above)

Further, when the deceleration is equal to or greater than the predetermined value g2, it is possible to take measures against the engagement interference such as immediately performing fail-safe control by determining that the engagement interference is immediately occurring. (Effects corresponding to claim 2)
In step 108, in addition to determining whether an oil temperature increase of a predetermined value or more has occurred within a predetermined period, for example, when the oil temperature increase gradient becomes a predetermined value or more, engagement interference has occurred. It may also be determined that the engagement interference has occurred when the oil temperature rise gradient is greater than before it is detected that the deceleration is greater than or equal to the predetermined value g1. it can.
Further, in the fail-safe control in step 105, for example, when all the frictional engagement elements are in a released state, it is not necessary to determine which frictional engagement element system has a failure and engagement interference has occurred. When fail-safe control is performed, the processing of steps 106 and 107 for recording the gear position can be omitted.

Next, a second embodiment will be described.
This embodiment is provided with an AT control unit 24A having different processing contents from the AT control unit 24 in FIG. 4 of the first embodiment, and the other configuration is the same as that of the first embodiment. Omitted.
Next, a procedure for detecting the engagement interference of the frictional engagement elements performed in the AT control unit 24A will be described.
FIG. 6 shows the flow of the engagement interference detection process.
Steps 200 to 203 and steps 205 to 209 are the same as steps 100 to 103 and steps 104 to 108 described with reference to FIG. 5 in the first embodiment. Will be described.

If it is determined in step 203 that the deceleration of the vehicle is equal to or greater than the predetermined value g2, it is determined in step 204 whether or not deceleration of the vehicle continues for a predetermined time t1 or more.
This is to determine whether or not the state in which the deceleration exceeding the predetermined value g1 is detected continues for a predetermined time or more after it is first detected in step 202 that the deceleration becomes the predetermined value g1 or more. It is.

When deceleration of the vehicle continues for a predetermined time t1 or more, the routine proceeds to step 205, where it is determined that engagement interference has occurred in the frictional engagement element. As a result, the process returns to step 200 and the above processing is repeated.
Here, when deceleration of the vehicle has continued for less than the predetermined time t1, for example, when the vehicle has been decelerated for a short time due to a change in the road surface (from a flat road to an uphill road) Since the case where the brake is applied and the vehicle decelerates only for a short time is considered, it is not determined that the engagement interference has occurred in such a case.
In this embodiment, steps 202 to 205 constitute the engagement interference detection means in the present invention, and step 200 constitutes the deceleration detection means in the present invention. Steps 201 and 209 constitute oil temperature rise detection means in the present invention.

  The present embodiment is configured as described above, and when the deceleration of the vehicle is equal to or greater than the predetermined value g2 and the vehicle deceleration state continues for the predetermined time t1 or more, or when the deceleration is equal to or greater than the predetermined value g1 and the oil temperature rises. In addition, when the deceleration state of the vehicle continues for a predetermined time t1 or longer, it is determined that the engagement interference is occurring in the frictional engagement element, so that the vehicle is temporarily decelerated due to, for example, a change in the road surface. In this case, it is possible to prevent erroneous determination that the engagement interference has occurred due to the deceleration of the vehicle even though the engagement interference has not occurred. Therefore, the detection accuracy of the engagement interference can be further improved by taking into account the duration of deceleration of the vehicle. (Effects corresponding to claim 3)

Next, a third embodiment will be described.
In this embodiment, an AT control unit 24B having different processing contents from the AT control unit 24 in the first embodiment is provided (see FIG. 7).
Note that the vehicle in this embodiment is a vehicle having a driving wheel and a driven wheel (a front wheel driving vehicle or a rear wheel driving vehicle), and the right driven wheel side vehicle speed sensor 40A for each wheel as shown in FIG. The left driven wheel side vehicle speed sensor 40B, the right drive wheel side vehicle speed sensor 50A, and the left drive wheel side vehicle speed sensor 50B are attached, and the vehicle speed can be calculated for each wheel.
As the vehicle speed sensors 40A, 40B, 50A, 50B attached to the respective wheels, for example, ABS vehicle speed sensors can be used.
Other configurations are the same as those of the first embodiment, and the same reference numerals are given and description thereof is omitted.

Next, a procedure for detecting the engagement interference of the frictional engagement elements performed in the AT control unit 24B will be described.
FIG. 8 shows the flow of the engagement interference detection process.
Steps 300, 302 to 304, and 306 to 310 are the same as steps 100, 101 to 103, and 104 to 108 described with reference to FIG. 5 in the first embodiment. , 305) only will be described.
In step 301, the vehicle speed for each wheel is calculated from the vehicle speed sensors 40A, 40B, 50A, 50B attached to each wheel.

When the deceleration of the vehicle is greater than or equal to the predetermined value g2, or when the deceleration is between g1 and g2 and the oil temperature rises greater than or equal to the predetermined value, in step 305, the vehicle speed for each wheel calculated in step 301 Based on this, it is determined whether or not the vehicle has slipped.
This determination is made when the difference between the vehicle speeds of the respective wheels is equal to or greater than a predetermined value, for example, when the vehicle speed of the driven wheel is low and the vehicle speed of the drive wheel is high, that the slip has occurred. .
If no slip has occurred in the vehicle, the routine proceeds to step 306, where it is determined that engagement interference has occurred in the frictional engagement element.
On the other hand, if slip has occurred, the process returns to step 300 and the above-described processing is repeated.

Here, when the vehicle slips due to road surface freezing or the like, the driving wheel returns to the grip state after the driving wheel is slipped. In this case, since the drive wheels are in a state close to being stopped from the high speed rotation state, the deceleration is calculated based on the deceleration calculated in step 300 (based on the detection result of the output shaft rotation sensor 38 that detects the rotation speed of the transmission output shaft O). The calculated deceleration) becomes large.
As a result, when it is determined that the deceleration is greater than or equal to the predetermined value g2, or when the deceleration is between the predetermined values g1 and g2 and the oil temperature has risen, there is no engagement interference. Regardless, it may be erroneously determined that engagement interference has occurred due to the deceleration caused by the slip.

Therefore, if the difference between the vehicle speeds of the wheels calculated based on the detection results of the vehicle speed sensors attached to the wheels is greater than or equal to a predetermined value, it is determined that the vehicle has slipped and is detected this time. It is determined that the change in deceleration is due to vehicle slip and not due to engagement interference.
In this embodiment, steps 301 and 303 to 306 constitute the engagement interference detection means in the present invention, and step 300 constitutes the deceleration detection means in the present invention. Steps 302 and 310 constitute oil temperature rise detecting means in the present invention. Further, the right driven wheel side vehicle speed sensor 40A and the left driven wheel side vehicle speed sensor 40B constitute the driven wheel side vehicle speed sensor in the present invention, and the right driving wheel side vehicle speed sensor 50A and the left driving wheel side vehicle speed sensor 50B are driven in the present invention. A wheel side vehicle speed sensor is configured.

This embodiment is configured as described above, and when the vehicle speed for each wheel calculated by a vehicle speed sensor attached to each wheel of the vehicle has a difference of a predetermined value or more, the vehicle is in a slip state. In this case, since the increase in the deceleration is caused by the transition from the slip state to the grip state, it is not determined that engagement interference has occurred in the frictional engagement element. Therefore, it is no longer erroneously determined that the engagement interference has occurred when the deceleration changes due to the vehicle changing from the slip state to the grip state, and the detection accuracy of the engagement interference is improved. It can be improved further. (Effects corresponding to claim 5)
In step 300, the output shaft rotation sensor 38 for calculating the deceleration of the vehicle is different from the right drive wheel side vehicle speed sensor 50A and the left drive wheel side vehicle speed sensor 50B. The vehicle speed on the driving wheel side can be calculated based on the detection result, or the deceleration of the vehicle can be calculated based on the detection result of the right driving wheel side vehicle speed sensor 50A and the left driving wheel side vehicle speed sensor 50B.

Each embodiment can be appropriately combined, such as combining the second embodiment and the third embodiment, or combining the first to third embodiments.
Thereby, the detection precision of engagement interference can be improved more.
Further, although the deceleration of the vehicle is calculated based on the output shaft rotational speed No from the output shaft rotation sensor 38, the deceleration can also be detected using an acceleration sensor or the like.

It is a figure which shows the gear train of an automatic transmission. It is a figure which shows the fastening logic table | surface in each gear stage. It is a figure which shows the shift control system of an automatic transmission. It is a block diagram which shows the electronic control system of the automatic transmission in the 1st, 2nd Example. It is a figure which shows the flow of the engagement interference detection process in a 1st Example. It is a figure which shows the flow of the engagement interference detection process in a 2nd Example. It is a block diagram which shows the electronic control system of the automatic transmission in a 3rd Example. It is a figure which shows the flow of the engagement interference detection process in a 3rd Example.

Explanation of symbols

1 Line pressure oil passage 2 Manual valve 3 D range pressure oil passage 24, 24A, 24B AT control unit 36 Oil temperature sensor 38 Output shaft rotation sensor 40A Right driven wheel side vehicle speed sensor (driven wheel side vehicle speed sensor)
40B Left driven wheel side vehicle speed sensor (driven wheel side vehicle speed sensor)
50A Right drive wheel side vehicle speed sensor (Drive wheel side vehicle speed sensor)
50B Left driven wheel side vehicle speed sensor (Drive wheel side vehicle speed sensor)
E Engine output shaft I Transmission input shaft O Transmission output shaft R / C Reverse clutch (Friction engagement element)
2-4 / B 2-4 Brake (Friction engagement element)
H / C High clutch (Friction engagement element)
L / C Low clutch (Friction engagement element)
L & R / B Low & Reverse Brake (Friction engagement element)

Claims (4)

An automatic transmission that includes a plurality of frictional engagement elements and obtains a desired gear position by fastening the frictional engagement elements by supplying hydraulic pressure to the frictional engagement elements in a predetermined combination, other than the predetermined combination In a frictional engagement element engagement interference detection device in an automatic transmission provided with an engagement interference detection means for detecting whether engagement interference occurs due to engagement of a frictional engagement element,
Deceleration detection means for detecting the deceleration of the vehicle;
Oil temperature rise detecting means for detecting whether or not the temperature characteristic of the oil in the automatic transmission has changed in the rising direction,
The engagement interference detecting means is
The deceleration detection means detects that the vehicle deceleration is greater than or equal to a first predetermined value,
And when it is detected by the oil temperature rise detection means that the temperature characteristic of the oil is changing in the increasing direction after the deceleration is detected to be equal to or greater than the first predetermined value, A friction engagement element engagement interference detecting device in an automatic transmission, wherein the engagement interference is detected as occurring. When the vehicle deceleration detected by the deceleration detection means is equal to or greater than a second predetermined value, which is a deceleration larger than the first predetermined value, the engagement interference detection means 2. The frictional engagement element engagement interference detection device for an automatic transmission according to claim 1, wherein it is detected that engagement interference occurs regardless of a detection result by the temperature rise detection means. The engagement interference detecting means is
A state in which a deceleration greater than or equal to the first predetermined value has been detected for a predetermined time or longer after the deceleration detection means detects that the vehicle deceleration has reached or exceeded the first predetermined value. 3. The frictional engagement element engagement interference detection device for an automatic transmission according to claim 1, wherein the engagement interference is detected as being caused by the engagement interference. A driven wheel side vehicle speed sensor for detecting the rotation state of the driven wheel of the vehicle;
A driving wheel side vehicle speed sensor for detecting the rotation state of the driving wheel of the vehicle,
The engagement interference detecting means is
When a deceleration greater than a first predetermined value is detected by the deceleration detection means,
When the difference between the vehicle speed calculated based on the detection result of the driven wheel side vehicle speed sensor and the vehicle speed calculated based on the detection result of the drive wheel side vehicle speed sensor is larger than a predetermined value, the engagement 4. The frictional engagement element engagement interference detection device for an automatic transmission according to claim 1, wherein the interference detection device does not detect that interference has occurred.

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