JP2010084875A - Automatic transmission control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automatic transmission control device for actualizing reliable transfer into a proper emergency travel mode. <P>SOLUTION: When shift is started and a fail detecting time passes, a fail determining means performs fail determination in accordance with a shift proceeding rate and the engaging pressure of an engaging side friction engaging element (S1-S4). When fail is detected in the fail determination (S5), fail action is executed (S6) and shift control is finished (S7). When the shift control is finished, a releasing failure specifying means detects that input torque recorded by a shift condition recording means gets to a predetermined input torque value great enough to give a change to an input shaft rotating speed (S10). When the input torque gets to the predetermined input torque value during shift, the releasing failure specifying means specifies the fail of the releasing side friction engaging element, and then an emergency counter counts up (S11). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a control device for an automatic transmission mounted on a vehicle or the like, and more particularly, to a control device for an automatic transmission capable of shifting to an emergency travel control (hereinafter referred to as an emergency travel mode) in the event of a failure. .

  In general, in a multi-stage automatic transmission mounted on a vehicle or the like, a plurality of friction engagement elements (clutches and brakes) are engaged according to the shift speed in order to form a transmission path of the transmission gear mechanism. It is hydraulically controlled. However, if hydraulic pressure is output to the hydraulic servo of the frictional engagement element that should have been released due to, for example, a failure of the linear solenoid valve (disconnection, valve stick, etc.), the frictional engagement element that is normally engaged In addition, there is a possibility that the frictional engagement element that should be released is engaged.

  Conventionally, in order to prevent such simultaneous engagement, when the engagement pressure of the friction engagement element engaged at normal time is input, the hydraulic pressure (its original pressure) of the other friction engagement elements is cut off. , So-called cutoff valves are provided in accordance with the combination of friction engagement elements that are engaged at each gear stage, thereby preventing simultaneous engagement at any gear stage. Has been devised (see Patent Document 1).

  However, due to recent demands for improving the fuel efficiency of vehicles due to environmental problems, etc., for example, small vehicles and the like are required to have multiple stages of automatic transmissions, and the number of frictional engagement elements for forming a shift stage is required. It tends to increase. In addition, from the viewpoint of vehicle mountability, the automatic transmission is also required to be downsized at the same time, and this tendency is particularly noticeable in the case of a small vehicle with a small mounting space. When the off-valve is used, the increase in the gear position not only prevents the hydraulic control device from being made compact, but also hinders weight reduction and cost reduction.

  Under the circumstances described above, a shift control device for an automatic transmission has been devised that attempts to fail-safe through control (see Patent Document 2). The shift control device described in Patent Document 2 includes a first shift threshold value that is a value between the gear ratios before and after the shift, and a second shift threshold value that is a value obtained by multiplying the gear ratio before the shift by a safety factor. And comparing the time until the actual gear ratio becomes the first gear shift threshold value without becoming the second gear shift threshold value with a preset detection time, thereby determining the fail state as the “air blow state” or It is configured so that it can be distinguished between the “drag state”.

JP 2000-274522 A JP 2007-255518 A

  As described in Patent Document 1, an automatic transmission control device that determines a failure of a friction engagement element based on a change in gear ratio within a predetermined time is a failure of the release side friction engagement element (failure of release). In some cases, it is possible to determine whether the engagement side frictional engagement element has failed or not. For example, when the input shaft speed does not change during power-off upshifting, the release side frictional engagement element is not released. Since the gear stage does not change, the input speed of the input shaft does not change, or the engagement side frictional engagement element has failed (unengaged) and is in the neutral state. There is a risk that the acceleration operation and the change in the input shaft rotational speed are balanced, so that it is impossible to distinguish whether the rotational speed change has occurred in the input shaft, and the frictional engagement element causing the failure may be erroneously specified. That.

  On the other hand, when a failure occurs in the friction engagement element, at least a fail safe action for performing control to stop the shift is performed, and when a failure of the friction engagement element is detected a predetermined number of times, from the normal traveling mode, the failure is detected. It is conceivable to shift to an emergency travel mode that regulates the gears that can be used during travel depending on the type (such as a frictional engagement element that has caused a failure, identification of a gear that cannot be normally achieved).

  For this reason, if the friction engagement element causing the failure is erroneously specified, there is a possibility that an appropriate emergency travel mode to be originally transferred cannot be selected. When shifting to an incorrect emergency travel mode, a gear stage that should be usable becomes unusable, and in the emergency travel mode, a failure occurs again due to a frictional engagement element that has actually failed.

  Accordingly, an object of the present invention is to provide a control device for an automatic transmission that can appropriately shift to an emergency travel mode when a failure occurs in a friction engagement element.

According to the first aspect of the present invention, the plurality of friction engagement elements (C-1, C-) that are engaged based on the engagement pressure supplied to the hydraulic servos (41, 42, 43, 44, 45), respectively. 2, C-3, B-1, B-2), an input shaft (8) connected to the drive source (2), and an output shaft connected to the drive wheel, the plurality of frictions The transmission path between the input shaft (8) and the output shaft is changed based on the engagement state of the engagement elements (C-1, C-2, C-3, B-1, B-2). In the control device (1) of the automatic transmission (3) that forms a plurality of shift stages,
Release failure specifying means (91) for specifying whether or not the failure is a release failure of the release side frictional engagement element (for example, C-3 clutch) when a failure occurs;
An emergency counter (92) that counts at least the number of times that the release-side frictional engagement element (for example, the C-3 clutch) has a release failure;
When the count of the emergency counter (92) reaches a predetermined number of times, the emergency travel mode is selected from the normal travel mode to the emergency travel mode in which the gear is selected so as not to release the friction engagement element that has failed to release. Transition means (93),
The emergency counter (92) counts the number of times when the release failure specifying means (91) specifies a failure as a release failure of the release side frictional engagement element (for example, C-3 clutch).
The control device (1) of the automatic transmission (3) is characterized by the above.

According to the second aspect of the invention, the shift state recording means (90) for recording the transition of the input torque (in Torque) during the shift,
In the release failure specifying means (91), the input torque (inTorque) to the automatic transmission (3) recorded in the shift status recording means (90) causes a change in the input shaft rotational speed (inRpm). When it is detected that the torque value (m) has been reached, and the input shaft rotation speed (inRpm) does not change more than a predetermined rotation speed, the release side frictional engagement element (for example, the C-3 clutch) Identify release defects,
A control device (1) for an automatic transmission (3) according to claim 1.

According to the invention of claim 3, when the release failure specifying means (91) detects that the input torque (inTorque) has reached the torque value (m) even once during a shift, the release-side specifying means (91) Identify the release failure of the friction engagement element,
A control device (1) for an automatic transmission (3) according to claim 2.

According to the invention of claim 4, the release failure specifying means (91) is configured such that the input torque to the automatic transmission (3) recorded in the shift status recording means (90) is the torque value (m). If it is not possible to detect that the release side friction engagement element is not specified,
The emergency counter (92) does not count the number of times when the release failure specifying means (91) does not specify a failure as a release failure of the release side frictional engagement element,
A control device (1) for an automatic transmission (3) according to claim 2 or 3.

According to the invention according to claim 5, a fail determination means (79) for determining a failure of the friction engagement element during a shift;
A fail-safe execution means (80) for executing a fail action and stopping at least the shift when the fail determination means (79) determines that a failure has occurred in the friction engagement element being shifted; ,
The release failure specifying means (91) specifies whether the fail is a release failure of the release side frictional engagement element after the fail safe execution means (80) executes a fail action.
A control device for an automatic transmission according to any one of claims 1 to 3.

  Note that the reference numerals in the parentheses are for comparison with the drawings, but this is for convenience to facilitate understanding of the invention and has no influence on the description of the claims. It is not a thing.

  According to the first aspect of the present invention, the emergency counter counts the number of failures when the release failure specifying means specifies that the release-side friction engagement element is not released correctly. Failure can be counted, and an appropriate emergency driving mode to be selected can be correctly selected and shifted.

  According to the second aspect of the present invention, the disengagement specifying means is configured to rotate the input shaft at a predetermined rotation speed regardless of whether the input torque to the automatic transmission is a torque value that causes a change in the input shaft rotation speed. When the change of more than a certain number does not occur, the release-side frictional engagement element is identified as a release failure, and therefore, the release-side frictional engagement element release failure can be identified with high accuracy. Emergency driving mode can be selected.

  According to the invention of claim 3, the release failure specifying means specifies the release failure of the release side frictional engagement element when detecting that the input torque has reached the torque value even once during the shift. Thus, the failure of the disengagement side frictional engagement element can be identified without overlooking, thereby allowing the emergency counter to appropriately count the number of failures.

  According to the fourth aspect of the invention, the release failure specifying means does not specify the friction engagement element causing the failure when the release failure of the release side frictional engagement element cannot be specified. However, it is possible to prevent erroneously counting the failure of the friction engagement element, thereby preventing erroneous selection of the emergency travel mode.

  According to the fifth aspect of the present invention, even if the failure determination of the frictional engagement element is not performed by performing the failure determination of the frictional engagement element separately from the transition control to the emergency travel mode. It is possible to appropriately cope with the generated failure by performing a fail-safe cushion that at least stops shifting.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments according to the present invention will be described below with reference to FIGS.

[Schematic configuration of automatic transmission]
First, a schematic configuration of an automatic transmission 3 to which the present invention can be applied will be described with reference to FIG. As shown in FIG. 2, an automatic transmission 3 suitable for use in, for example, an FF type (front engine, front drive) vehicle is an automatic transmission 3 that can be connected to an engine (drive source) 2 (see FIG. 1). An input shaft 8 is provided, and a torque converter 4 and an automatic transmission mechanism 5 are provided around the axial direction of the input shaft 8.

  The torque converter 4 includes a pump impeller 4a connected to the input shaft 8 of the automatic transmission 3, and a turbine runner 4b to which the rotation of the pump impeller 4a is transmitted via a working fluid. The runner 4 b is connected to the input shaft 10 of the automatic transmission mechanism 5 disposed coaxially with the input shaft 8. Further, the torque converter 4 is provided with a lock-up clutch 7, and when the lock-up clutch 7 is engaged, the rotation of the input shaft 8 of the automatic transmission 3 causes the input shaft of the automatic transmission mechanism 5 to rotate. 10 is transmitted directly.

  The automatic transmission mechanism 5 includes clutches C-1, C-2, C-3 and brakes B-1, which are engaged based on engagement pressures respectively supplied to the hydraulic servos 41 to 45 (see FIG. 5). B-2, an input shaft 10 connected to the engine 2, and a counter gear 11 connected to a drive wheel (not shown), the clutches C-1, C-2, C-3, brake B -1 and B-2 are used to change the transmission path between the input shaft 10 and the counter gear 11 to form a plurality of shift stages. The automatic transmission mechanism 5 includes an input shaft 10, a planetary gear SP and a planetary gear unit PU are provided. The planetary gear SP is a so-called single pinion planetary gear that includes a sun gear S1, a carrier CR1, and a ring gear R1, and has a pinion P1 that meshes with the sun gear S1 and the ring gear R1.

  The planetary gear unit PU has a sun gear S2, a sun gear S3, a carrier CR2, and a ring gear R2 as four rotating elements. The long gearion PL that meshes with the sun gear S2 and the ring gear R2 and the sun gear S3 This is a so-called Ravigneaux type planetary gear that has meshing short pinions PS that mesh with each other.

  The sun gear S <b> 1 of the planetary gear SP is connected to a boss portion that is integrally fixed to the mission case 9, and the rotation is fixed. The ring gear R1 is in the same rotation as the rotation of the input shaft 10 (hereinafter referred to as “input rotation”). Further, the carrier CR1 is decelerated by reducing the input rotation by the fixed sun gear S1 and the ring gear R1 that rotates, and the clutch (friction engagement element) C-1 and the clutch (friction engagement). Element) connected to C-3.

  The sun gear S2 of the planetary gear unit PU is connected to a brake B-1 formed of a band brake so as to be freely fixed to the transmission case, and is connected to the clutch C-3 via the clutch C-3. Thus, the decelerated rotation of the carrier CR1 can be input. The sun gear S3 is connected to the clutch C-1, so that the decelerated rotation of the carrier CR1 can be input. The brake B-1 has a brake band 19 provided around a drum-shaped member 18 connected to the clutch C-3 and the sun gear S2. The brake band 19 is fixed to the case 9 at one end. The other end is connected to a hydraulic servo 44 (see FIG. 5), which will be described later, and is wound around the drum-shaped member 18 by driving the hydraulic servo 44. The winding direction of the brake band 19 is disposed so as to be opposite to the rotation direction of the drum-shaped member 18 from the first forward speed to the second forward speed. It is configured to perform winding by pulling in the reverse direction from the rotational speed in the second forward speed from the speed stage.

  Further, the carrier CR2 is connected to a clutch C-2 to which the rotation of the input shaft 10 is input, and the input rotation can be freely input through the clutch C-2, and the one-way clutch F-1 and Connected to the brake B-2, rotation in one direction is restricted with respect to the transmission case via the one-way clutch F-1, and rotation can be fixed via the brake B-2. The ring gear R2 is connected to a counter gear (output shaft) 11, and the counter gear 11 is connected to a driving wheel (not shown) via a counter shaft (not shown) and a differential device.

[Operation of each gear stage in automatic transmission]
Next, based on the above configuration, the operation of the automatic transmission mechanism 5 will be described with reference to FIGS. 2, 3, and 4. In the velocity diagram shown in FIG. 4, the vertical axis indicates the rotational speed of each rotating element (each gear), and the horizontal axis indicates the gear ratio of these rotating elements. Further, in the planetary gear SP portion of the velocity diagram, the vertical axis corresponds to the sun gear S1, the carrier CR1, and the ring gear R1 in order from the left side in FIG. Furthermore, in the planetary gear unit PU of the velocity diagram, the vertical axis corresponds to the sun gear S3, the ring gear R2, the carrier CR2, and the sun gear S2 in order from the right side in FIG.

  For example, in the D (drive) range and the first forward speed (1ST), as shown in FIG. 3, the clutch C-1 and the one-way clutch F-1 are engaged. Then, as shown in FIGS. 2 and 4, the rotation of the carrier CR1 that is decelerated by the fixed sun gear S1 and the ring gear R1 that is the input rotation is input to the sun gear S3 via the clutch C-1. Further, the rotation of the carrier CR2 is restricted in one direction (forward rotation direction), that is, the carrier CR2 is prevented from rotating in the reverse direction and is fixed. Then, the decelerated rotation input to the sun gear S3 is output to the ring gear R2 via the fixed carrier CR2, and the forward rotation as the first forward speed is output from the counter gear 11.

  During engine braking (coast), the brake B-2 is locked to fix the carrier CR2, and the forward first speed state is maintained by preventing the carrier CR2 from rotating forward. . Further, at the first forward speed, the one-way clutch F-1 prevents the carrier CR2 from rotating in the reverse direction and enables forward rotation, so that the first forward speed when switching from the non-traveling range to the traveling range, for example. Can be smoothly achieved by the automatic engagement of the one-way clutch F-1.

  At the second forward speed (2ND), as shown in FIG. 3, the clutch C-1 is engaged and the brake B-1 is locked. Then, as shown in FIGS. 2 and 4, the rotation of the carrier CR1 that is decelerated by the fixed sun gear S1 and the ring gear R1 that is the input rotation is input to the sun gear S3 via the clutch C-1. Further, the rotation of the sun gear S2 is fixed by the locking of the brake B-1. Then, the carrier CR2 is decelerated and rotated at a speed lower than that of the sun gear S3, the decelerated rotation input to the sun gear S3 is output to the ring gear R2 via the carrier CR2, and the forward rotation as the second forward speed is counter gear. 11 is output.

  In the third forward speed (3RD), as shown in FIG. 3, the clutch C-1 and the clutch C-3 are engaged. Then, as shown in FIGS. 2 and 4, the rotation of the carrier CR1 that is decelerated by the fixed sun gear S1 and the ring gear R1 that is the input rotation is input to the sun gear S3 via the clutch C-1. Further, the reduced rotation of the carrier CR1 is input to the sun gear S2 by the engagement of the clutch C-3. That is, since the reduction rotation of the carrier CR1 is input to the sun gear S2 and the sun gear S3, the planetary gear unit PU is directly connected to the reduction rotation, and the reduction rotation is output to the ring gear R2 as it is, and the forward rotation as the third forward speed is performed. Output from the counter gear 11.

  At the fourth forward speed (4TH), as shown in FIG. 3, the clutch C-1 and the clutch C-2 are engaged. Then, as shown in FIGS. 2 and 4, the rotation of the carrier CR1 that is decelerated by the fixed sun gear S1 and the ring gear R1 that is the input rotation is input to the sun gear S3 via the clutch C-1. Further, the input rotation is input to the carrier CR2 by engaging the clutch C-2. Then, by the decelerated rotation input to the sun gear S3 and the input rotation input to the carrier CR2, the rotation speed is higher than the third forward speed and is output to the ring gear R2, and the forward rotation as the fourth forward speed is performed. The rotation is output from the counter gear 11.

  At the fifth forward speed (5TH), as shown in FIG. 3, the clutch C-2 and the clutch C-3 are engaged. Then, as shown in FIGS. 2 and 4, the rotation of the carrier CR1 that is decelerated and rotated by the fixed sun gear S1 and the ring gear R1 that is the input rotation is input to the sun gear S2 via the clutch C-3. Further, the input rotation is input to the carrier CR2 by the engagement of the clutch C-2. Then, due to the decelerated rotation input to the sun gear S2 and the input rotation input to the carrier CR2, the rotation speed is slightly higher than the input rotation and is output to the ring gear R2, which is the forward rotation as the fifth forward speed. Is output from the counter gear 11.

  At the sixth forward speed (6TH), as shown in FIG. 3, the clutch C-2 is engaged and the brake B-1 is locked. Then, as shown in FIGS. 2 and 4, the input rotation is input to the carrier CR2 by the engagement of the clutch C-2. Further, the rotation of the sun gear S2 is fixed by the locking of the brake B-1. Then, the input rotation of the carrier CR2 becomes higher than the forward fifth speed by the fixed sun gear S2, and is output to the ring gear R2, and the forward rotation as the sixth forward speed is output from the counter gear 11. .

  In the first reverse speed (REV), as shown in FIG. 3, the clutch C-3 is engaged and the brake B-2 is locked. Then, as shown in FIGS. 2 and 4, the rotation of the carrier CR1 that is decelerated and rotated by the fixed sun gear S1 and the ring gear R1 that is the input rotation is input to the sun gear S2 via the clutch C-3. Further, the rotation of the carrier CR2 is fixed by the locking of the brake B-2. Then, the decelerated rotation input to the sun gear S2 is output to the ring gear R2 via the fixed carrier CR2, and the reverse rotation as the first reverse speed is output from the counter gear 11.

  For example, in the P (parking) range and the N (neutral) range, the clutch C-1, the clutch C-2, and the clutch C-3 are released. Then, the carrier CR1, the sun gear S2, and the sun gear S3, that is, the planetary gear SP and the planetary gear unit PU are disconnected, and the input shaft 10 and the carrier CR2 are disconnected. Thereby, the power transmission between the input shaft 10 and the planetary gear unit PU is disconnected, that is, the power transmission between the input shaft 10 and the counter gear 11 is disconnected.

[Schematic configuration of hydraulic control unit]
Next, the hydraulic control device 6 for an automatic transmission according to the present invention will be described. First, generation parts such as a line pressure, a secondary pressure, a modulator pressure, and a range pressure, which are not shown in the hydraulic control device 6 (see FIG. 1), will be roughly described. The generation portions of the line pressure, secondary pressure, modulator pressure, and range pressure are the same as those of a general automatic transmission hydraulic control device, and are well-known and will be described briefly.

  The hydraulic control device 6 includes, for example, an oil pump, a manual shift valve, a primary regulator valve, a secondary regulator valve, a solenoid modulator valve, a linear solenoid valve SLT, and the like (not shown). For example, the engine 2 (see FIG. 1) When started, the oil pump that is rotationally connected to the pump impeller 4a of the torque converter 4 is driven in conjunction with the rotation of the engine 2 to suck up oil from an oil pan (not shown) through a strainer. Generate hydraulic pressure in the form.

Hydraulic pressure generated by the oil pump, on the basis of a signal pressure P _SLT of the linear solenoid valve SLT that is pressure regulating output according to the throttle opening degree, the pressure is adjusted to a line pressure P _L being discharged adjusted by the primary regulator valve . The line pressure P _L is the manual shift valve, the solenoid modulator valve, and more information is supplied to the linear solenoid valve SLC3 to be described later. The line pressure P _L supplied to the solenoid modulator valve of this is pressure regulated to a modulator pressure P _MOD to be substantially constant pressure by the valve, the modulator pressure P _MOD is the original pressure, such as the linear solenoid valve SLT Supplied as

The pressure discharged from the primary regulator valve is adjusted to the secondary pressure _PSEC while being further discharged and adjusted by, for example, the secondary regulator valve, and this secondary pressure _PSEC is supplied to, for example, a lubricating oil passage or an oil cooler. And also supplied to the torque converter 4 and used to control the lock-up clutch 7.

On the other hand, a manual shift valve (not shown) has a spool that is mechanically (or electrically) driven by a shift lever provided in a driver's seat (not shown), and the position of the spool is controlled by the shift lever. selected shift range (e.g. P, R, N, D) by being switched according to, to set the output state or non-output state of the line pressure P _L the input (drain).

In particular, when the D range based on the operation of the shift lever, through said line pressure P _L is communicated with the input port to be input and a forward range pressure output port based on the position of the spool, the forward range pressure output line from the port pressure P _L is output as a forward range pressure (D range pressure) P _D. When based on the operation of the shift lever to the R (reverse) range, communicates with the input port and the reverse range pressure output port based on the position of the spool, the line pressure P _L rear proceeds range pressure output port reverse range Pressure (R range pressure) _PREV is output. Further, when the P range and the N range are set based on the operation of the shift lever, the input port, the forward range pressure output port and the reverse range pressure output port are blocked by the spool, and the forward range pressure output. port and the reverse range pressure output port are communicated with the drain port, that is, the non-output state D range pressure P _D and the R range pressure P _REV are drained (discharged).

[Configuration of shift control portion in hydraulic control device]
Next, a portion that mainly performs shift control in the hydraulic control device 6 according to the present invention will be described with reference to FIG. FIG. 5 is a circuit diagram schematically showing an excerpt of the hydraulic control device 6 of the automatic transmission. The hydraulic control device 6 includes the hydraulic servo 41 for the clutch C-1, the hydraulic servo 42 for the clutch C-2, the hydraulic servo 43 for the clutch C-3, the hydraulic servo 44 for the brake B-1, and the brake B-2. Four linear solenoid valves SLC1, SLC2, SLC3, and SLB1 for directly supplying output pressures adjusted as engagement pressures to each of a total of five hydraulic servos of the hydraulic servo 45 are provided. In addition, a switching valve 23 that achieves a limp home function and switches the output pressure of the linear solenoid valve SLC2 to the hydraulic servo 42 of the clutch C-2 or the hydraulic servo 45 of the brake B-2 is provided. The switching valve 23 is not actually a single valve, but a solenoid valve (not shown), a first clutch apply relay valve, a second clutch apply relay valve, a C-2 relay valve, a B-2 relay valve, or the like. It is drawn in an aggregated form.

A forward range pressure output port (not shown) of the manual shift valve described above is connected to the oil passage a1 to the linear solenoid valve SLC1, the oil passage a4 to the linear solenoid valve SLC2, and the oil passage a5 to the linear solenoid valve SLB1. is configured to forward range pressure P _D can be input Te, in addition, the oil passage d to the linear solenoid valve SLC3, the line pressure P _L from the primary regulator valve (not shown) is input.

The linear solenoid valve SLC1 is of a normally closed type that when not energized in a non-output state, the input port SLC1a for receiving the forward range pressure P _D via the oil path a1, by regulating the forward range pressure P _D and an output port SLC1b for outputting as the engagement pressure _{P C1} control pressure _{P SLC1} to the hydraulic servo 41 Te.

The linear solenoid valve SLC2 is a normally open type that attains an outputting state when being de-energized, the input port SLC2a for receiving the forward range pressure P _D via the oil path a4, and by regulating the forward range pressure P _D The hydraulic servo 42 has an output port SLC2b that outputs the control pressure P _SLC2 as the engagement pressure P _C2 (or engagement pressure P _B2 ).

The linear solenoid valve SLC3 is a normally open type that attains an outputting state when being de-energized, the input port SLC3a which inputs the line pressure P _L via the oil passage d, the hydraulic servo by regulating the line pressure P _L and an output port SLC3b for outputting a control pressure _{P SLC3} as the engagement pressure _{P C3} to 43.

The linear solenoid valve SLB1 is of a normally closed type that when not energized in a non-output state, the input port SLB1a for receiving the forward range pressure P _D through the oil passage a5, by regulating the forward range pressure P _D and an output port SLB1b to output as the engagement pressure _{P B1} control pressure _{P SLB1} to the hydraulic servo 44 Te.

[Configuration of automatic transmission control device]
Next, the control apparatus 1 for an automatic transmission according to the present invention will be described mainly with reference to FIG.

  As shown in FIG. 1, the control device 1 of the automatic transmission includes a control unit (ECU) 70, which includes an accelerator opening sensor 81, an input shaft rotational speed sensor 83, and an output shaft. A rotation speed (vehicle speed) sensor 82 and the like are connected, and are connected to the linear solenoid valves SLC1, SLC2, SLC3, and SLB1 of the hydraulic control device 6 described above. In addition, an engine speed signal and an engine torque signal are sent from the engine 2 to the control unit 70.

  The control unit 70 includes a hydraulic pressure command means 71 having a normal time hydraulic pressure setting means 72, an input torque detection means 73, a torque sharing determination means 74, a shift determination means 75, and a shift map map. Further, the control unit 70 is provided with a shift progress rate calculating means 78, an engagement pressure monitoring means 77, a fail determining means 79, and a fail safe executing means 80.

  Further, the control unit 70 detects a shift state recording unit 90 that records a shift state based on a shift start control signal (shift start determination) from the shift determination unit and a release failure of the disengagement side frictional engagement element. The release failure specifying means 91 to be specified, an emergency counter 92 for counting the number of failures occurring in each friction engagement element, and emergency travel for switching to an emergency travel mode to be described later when the emergency counter 92 reaches a predetermined number Mode transition means 93.

  The shift determination means 75 refers to the shift map map based on the accelerator opening detected by the accelerator opening sensor 81 and the vehicle speed detected by the output shaft rotational speed sensor 82, and the above-mentioned first forward speed to The sixth forward speed is determined. That is, an upshift shift line and a downshift shift line (shift point) corresponding to the accelerator opening and the vehicle speed are recorded in the shift map map, and the accelerator opening and the vehicle speed at that time exceed these shift lines. Then, the shift determination means 75 determines the shift. The shift speed (current shift speed) determined by the shift determination means 75 is output to the hydraulic pressure command means 71 and the torque sharing determination means 74.

  On the other hand, the input torque detection means 73 calculates the input torque inTorque (engine torque * torque converter torque ratio) currently input to the input shaft 10 of the automatic transmission mechanism 5 based on the engine torque from the engine 2 and the torque converter torque ratio. To detect. Further, the torque sharing determination means 74 is based on the gear determined by the shift determination means 75, and the torque sharing in the clutch or brake (see FIG. 3) engaged in the automatic transmission mechanism 5, that is, each gear ratio. Based on the above, the ratio to the input torque in Torque required for the clutch or brake is determined (calculated).

  Next, the normal time hydraulic pressure setting means 72 multiplies the torque sharing in the engaged clutch or brake determined by the torque sharing determination means 74 according to the gear position, and further multiplies the safety factor. The torque sharing value and the input torque inTorque detected by the input torque detecting means 73 are multiplied to calculate the torque capacity (transmission torque) of the engaged clutch or brake, and the number and area of friction plates of each clutch or brake. From the pressure receiving area of the hydraulic servo, the engagement pressure (control pressure) supplied to the hydraulic servo of the clutch or brake being engaged is calculated.

  Based on the engagement pressure set by the normal-time hydraulic pressure setting means 72, the hydraulic pressure command means 71 supplies the engagement pressure to the hydraulic servo of the clutch or brake being engaged. An electric command is given to the solenoid valves SLC1, SLC2, SLC3, SLB1, that is, during traveling under normal conditions, a clutch and a brake are engaged so that a torque capacity that takes into account a safety factor is added to the input torque inTorque. Even if the engine torque fluctuates or receives torque fluctuations from the drive wheels due to road conditions or the like, the clutch and the brake are engaged so as not to slip.

  Since the pump impeller 4a of the torque converter 4 and the turbine hub (not shown) of the engine 2 rotate at substantially the same rotational speed, the torque (input torque) of these input shafts 8 and 10 is also substantially the same. It is. Therefore, in the present invention, the input torque inTorque may be either the engine torque or the turbine torque.

[Automatic transmission control]
Next, the transition control to the emergency travel mode, which is the main part of the present invention, will be described in detail mainly based on FIGS. 6 and 7 by taking the power-off-up shift as an example.

  First, the normal power-off upshift will be described. When the shift determination unit 79 refers to the shift map map based on signals from the accelerator opening sensor 81 and the output shaft rotational speed sensor 82 and determines the start of the power-off upshift, the shift timer setting unit 85 sets it. Within the release preparation time, the hydraulic pressure command means 71 sweeps down the release side hydraulic pressure, which is the engagement pressure of the release side friction engagement element, until just before the friction engagement element starts to slide (release preparation control).

  Further, the engagement side frictional engagement element also increases the engagement side hydraulic pressure of the release side hydraulic pressure in response to the start of the release preparation of the release side frictional engagement element, and immediately before the engagement of the frictional engagement element. Servo start-up control is performed. The servo activation control includes the first half stroke pressure control (servo A control), which is a so-called loosening operation, and the second half engagement preparation control (just before the engagement side frictional engagement element starts engagement). Servo B control).

  When the servo activation control is completed, the engagement side frictional engagement element gradually increases the engagement side hydraulic pressure, and shifts to the engagement control for actually engaging the engagement side frictional engagement element slowly. When the release preparation control is finished, the release side frictional engagement element is swept down and released as quickly as possible in the range where no shift shock occurs.

  When the engagement control time elapses, the disengagement side and engagement side frictional engagement elements shift to completion control, and the shift is completed when the completion control time elapses. Note that, during the power-off upshift described above, the accelerator opening is a value that is substantially close to zero, and when the engagement control starts, the gear ratio changes, whereby the input shaft speed of the automatic transmission changes. inRpm decreases (see FIG. 6a).

Next, fail safe control will be described. As shown in FIG. 7, the speed change decision means 75 is started the shift is judged (S1), when the release preparation control described above ends, the fail detection timer t ₁ set by the fail detection timer setting unit 86 is started (S2).

The failure detection timer t ₁ is set to switching shift gripping ends at a time prior than complete control is completed, when the failure detection timer t ₁ is completed after a predetermined period of time has elapsed (S3), A failure determination unit 79 determines a failure (S4).

Failure determining means 79, and the shift progress degree ShiftR, has the engagement pressure detected by the engagement pressure monitoring means 77 and the detection condition of the fail, at the end of the fail detection timer t _1, the shift progress degree ShiftR speed change When the hydraulic pressure command value for the engagement side hydraulic pressure is lower than the progress rate threshold G and the hydraulic pressure command value for the engagement side hydraulic pressure is larger than the engagement pressure threshold value N, the hydraulic pressure command is sufficient to cause a change in the input shaft rotation speed. It not, as a fail-detection timer t ₁ of the end to the shift progress degree ShiftR (input shaft rotational speed InRpm) has progressed to the normal value to proceed naturally, if during the shift, not in a normal speed state ( It is determined that a failure of the frictional engagement element has occurred (S5).

  When the failure determination means 79 determines that the friction engagement element has failed, a control signal is output from the failure determination means 79 to the fail safe execution means 80. Based on this control signal, the fail safe execution means 80 performs a fail action for stopping the shift and returning it to the shift stage before the start of the shift (S6). When the fail-a cushion is finished, the shift control is also finished (S7).

  Further, in the fail determination of the fail determination means 79 (S4), if neither of the shift progress rate ShiftR or the engagement pressure condition is satisfied, it is regarded as a normal shift state (S8), and the above-described normal operation is performed. After the shift control is performed, the shift control is terminated (S9).

Incidentally, the failure detection timer t ₁ is the frictional engagement element on the engagement side is started engages descends input shaft rotational speed InRpm, whereby the shift progress degree to fail decision if normal control state It is a period that is sufficiently advanced.

  Further, the shift progress rate ShiftR is calculated based on the rotation speed of the input shaft 10 given from the input shaft speed sensor 83 and the counter gear 11 given from the output shaft speed sensor 82 during the shift by the shift progress rate calculation means 78. This value is calculated based on the degree of reach from the rotation speed ratio with the rotation speed to the transmission gear ratio of the next gear stage to be shifted.

Furthermore, shift progress rate threshold G is supposed value if the normal shift control failure detection timer t ₁ is sufficiently greater than if elapsed and is set to a value that does not erroneously detect a fail. Further, the engagement pressure threshold value N is set to a value (torque capacity at the time of engagement control) that can sufficiently engage the friction engagement element on the engagement side at the time of shifting.

  Next, the emergency travel mode will be described. The control device 1 of the automatic transmission 3 is running when the friction engagement element, in particular, the disengagement side friction engagement element has failed in addition to the normal travel mode in which the normal travel shift control described above is performed. The vehicle has an emergency travel mode that regulates the gears that can be used.

  There are a plurality of types of emergency travel modes depending on the type of failure. In the present embodiment, the release side emergency travel mode when the release side frictional engagement element fails, and the engagement side frictional engagement mode. There is an engagement emergency travel mode when the element fails, but it is sufficient that at least the release side emergency travel mode is provided. Conversely, the emergency travel mode may be further subdivided depending on the type of failure. Good.

  As an example of the release-side emergency travel mode described above, as shown in FIG. 8, the clutch C-3, which is the release-side frictional engagement element, is released when shifting from the fifth forward speed to the fourth forward speed. A case where a defect occurs will be described. When the emergency counter 92 reaches a predetermined count number (number of times), the emergency travel mode transition means 93 shifts the travel mode from the normal travel mode to the release-side emergency travel mode.

When the disengagement emergency travel mode is started by a control signal from the emergency travel mode transition means 93 (S20), the shift speed is fixed to the fifth forward speed that does not release the clutch C-3 that has caused the disengagement failure. (S21). Then, the vehicle speed V becomes lower than the speed threshold value V ₁ is the value of the limit for maintaining the fifth forward speed becomes insufficient driving force (S22), the shift gear position is fixed to the forward third speed is prohibited (S23).

  Thus, in the release-side emergency travel mode, control is performed to restrict the release-side frictional engagement element that has caused the release failure to be limited to a speed that does not release, so that a running gear is formed. Abrupt shift shocks are prevented by dropping from the high speed stage to the low speed stage according to the vehicle speed.

  Further, in the engagement-side emergency travel mode, the use of a shift stage formed by engagement of friction engagement elements that have been engaged poorly is prohibited, and shift control is performed in which the vehicle travels only at other shift stages. Further, in the case of a failure of the engagement side frictional engagement element, control may be performed so that the upshift is repeated until the gear position at which the gear ratio is established at each failure without shifting to the emergency travel mode.

Next, transition control from the normal travel mode to the emergency travel mode will be described. In FIG. 7, when the fail action is performed (S6) and the shift control is completed (S7), the release failure specifying unit 91 refers to the transition of the input torque inTorque recorded by the shift state recording unit 90. It is determined whether or not the input torque inTorque during the shift has exceeded a low torque region X (m ₁ <X> m ₂ ) that is a slight influence on the input shaft rotational speed inRpm (S10). . In other words, it is detected that the input torque inTorque has reached a torque value m that causes a change in the input shaft rotational speed inRpm (S10).

The torque value m is a range other than the low torque region X, and the torque threshold values m ₁ and m ₂ are set in a range of approximately 0 Nm. The low torque region X is from the pulsation of the engine and the wheel side. This is an error range in which the input torque varies depending on the torque. Therefore, as shown in part b of the input torque line B in FIG. 6, the disengagement failure specifying means 91 is configured so that the input shaft inTorque has a fluctuation exceeding the low torque region X even once during the shift. If there is no change in the rotational speed inRpm,
Even if the input torque value m can sufficiently affect the input shaft rotational speed inRpm, it is assumed that no change has occurred in the input shaft rotational speed inRpm, and the failure is the release of the disengagement side frictional engagement element. Identify as bad.

  The emergency counter 92 has at least as many counters as the number of emergency driving modes. In this embodiment, the emergency counter 92 includes a release-side counter for the release-side frictional engagement element failure, and an engagement-side frictional engagement element failure. The disengagement counter can count the failure separately for each friction engagement element. Further, the engagement counter is set for each gear stage and counts a failure.

  The emergency counter 92 counts up the number of counters of the frictional engagement element that has caused the failure when the type of failure and the frictional engagement element that has caused the failure can be identified. When the release side frictional engagement element 91 that has caused a failure is identified, the number of release side counters of the frictional engagement element that has caused the failure is counted up (S11).

  When the emergency counter reaches a predetermined number of times, the occurrence of a failure is regarded as deterministic (irreversible), and the emergency travel mode transition means shifts from the normal travel mode to the emergency travel mode suitable for the type of failure. .

  On the other hand, as shown in the input torque line A in FIG. 6, if the input torque inTorque does not fluctuate beyond the low torque region X even during the shift, it can be determined that a failure has occurred in the friction engagement element. Since it is impossible to specify whether the failure is the release-side friction engagement element or the engagement-side friction engagement element, the release failure specifying means 91 does not specify the failed friction engagement element, and the emergency counter 92 does not count failures.

  By configuring the automatic transmission control device 1 as described above, the emergency counter 92 counts the number of failures when the release failure specifying means 91 specifies that the release side frictional engagement element is not released correctly. Therefore, the number of times of the emergency counter 92 of the friction engagement element that has caused the failure can be counted up reliably, and an appropriate emergency travel mode to be originally selected can be correctly selected and shifted.

  Further, the disengagement specifying means 91 changes the torque value that causes the input torque inTorque to fluctuate outside the low torque region X where the input shaft rotational speed inRpm has a slight effect on the input shaft rotational speed inRpm during the shift. When the input shaft rotational speed inRpm does not change more than the predetermined rotational speed in spite of having reached m, the release-side frictional engagement element is identified with high accuracy in order to specify that the release-side frictional engagement element is defectively released. It is possible to identify the release failure of the joint element.

  Further, when it is detected that the input torque inTorque has reached the predetermined torque value m even once during the shift, the release-side frictional engagement element of the release-side frictional engagement element is identified by specifying the release failure of the release-side frictional engagement element. A release failure can be detected with higher accuracy.

  As described above, the release failure of the disengagement side frictional engagement element can be detected with higher accuracy, and the input torque inTorque during shifting changes within the low torque region X, and the release failure specifying means 91 fails. If it cannot be detected, the friction engagement element that caused the failure is not identified, so the emergency counter 92 does not count the failure of the wrong friction engagement element and selects the appropriate emergency travel mode accurately. can do.

Further, even if the release failure specifying means 91 cannot specify the friction engagement element that has caused the failure, the fail determining means 79 performs the fail determination separately. Can respond appropriately.
Note that the fail-a cushion does not return to the gear stage before the shift when the failing frictional engagement element can be identified, but fails when the release-side frictional engagement element is not fully released. The disengagement-side frictional engagement element may be shifted to another speed stage that does not release. In the case of a failure of the engagement-side frictional engagement element, the frictional engagement element in which the failure has occurred is not used. You may change speed.

  Moreover, although the automatic transmission 3 of the present embodiment described above has been described as an example that can achieve the sixth forward speed, the automatic transmission to which the present invention can be applied is not limited thereto. Of course, other types of automatic transmissions may be used.

The block diagram which shows the control apparatus of the automatic transmission which concerns on this invention. The skeleton figure which shows the automatic transmission which can apply this invention. The engagement table of this automatic transmission mechanism. The speed diagram of this automatic transmission mechanism. FIG. 2 is a circuit diagram schematically showing an excerpt of a hydraulic control device of the automatic transmission. The time graph figure which shows the change of each part in the case of power-off up transmission. The flowchart explaining the effect | action of the control apparatus of this automatic transmission. The flowchart explaining emergency driving mode.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Control apparatus of automatic transmission 2 Drive source 8 Input shaft 41, 42, 43, 44, 45 Hydraulic servo 79 Fail determination means 80 Fail safe execution means 90 Shift condition recording means 91 Release defect specification means 92 Emergency counter 93 Emergency travel mode Transition means C-1, C-2, C-3, B-1, B-2 Friction engagement element m Torque value in Torque Input torque

Claims (5)

A plurality of friction engagement elements engaged based on engagement pressures respectively supplied to the respective hydraulic servos, an input shaft connected to a drive source, and an output shaft connected to a drive wheel, In a control device for an automatic transmission that forms a plurality of shift stages by changing a transmission path between the input shaft and the output shaft based on an engagement state of a plurality of friction engagement elements,
A release failure specifying means for specifying whether the failure is a release failure of the release side frictional engagement element when a failure occurs;
An emergency counter that counts at least the number of times the release-side frictional engagement element has a release failure;
Emergency travel mode transition means for switching from the normal travel mode to the emergency travel mode for selecting and driving a gear stage that does not release the friction engagement element in which the release failure has occurred when the count of the emergency counter reaches a predetermined number of times; With
The emergency counter is configured to count the number of times when the release failure specifying means specifies a failure as a release failure of the release side frictional engagement element.
A control device for an automatic transmission. A shift status recording means for recording the transition of the input torque during the shift,
The unsatisfactory release specifying means detects that the input torque to the automatic transmission recorded in the shift status recording means has become a torque value that causes a change in the input shaft rotational speed, and rotates the input shaft. When the number does not change more than a predetermined number of revolutions, the release-side frictional engagement element is identified as being unsatisfactory.
The control device for an automatic transmission according to claim 1. The release failure specifying means specifies a release failure of the release side frictional engagement element when detecting that the input torque has reached the torque value even once during a shift.
The control apparatus for an automatic transmission according to claim 2. The release failure specifying means determines that the release side frictional engagement element is not released when it cannot detect that the input torque to the automatic transmission recorded in the shift status recording means has reached the torque value. Not specific
The emergency counter does not count the number of times when the release failure specifying means does not specify a failure as a release failure of the release side frictional engagement element,
The control device for an automatic transmission according to claim 2 or 3. Fail determination means for determining a failure of the friction engagement element during a shift;
A fail-safe execution means for executing a fail action when the failure determination means determines that a failure has occurred in the frictional engagement element during a shift, and at least stopping the shift;
The release failure specifying means specifies whether the fail is a release failure of the release side frictional engagement element after the fail safe execution means executes a fail action.
The control device for an automatic transmission according to any one of claims 1 to 3.

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