JP4621969B2 - Control device for automatic transmission - Google Patents

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic transmission control device, and more particularly to an automatic transmission control device that protects a starting clutch and prevents a vehicle from moving backward on an uphill road in an automatic transmission that automates a gear-type manual transmission. .

  A vehicle is provided with a power transmission device including an automatic transmission for converting and taking out the driving force of an engine as required according to a traveling condition, a transfer for distributing the driving force, and the like.

  In general automatic transmissions that use a torque converter as a starting mechanism, even when the accelerator pedal is not depressed, there is a creep phenomenon that generates driving force, and operation when traveling at extremely low speeds such as traffic jams and garage entry Has become common among users accustomed to automatic transmissions. For this reason, even in an automatic transmission that does not naturally generate creep, such as a continuously variable transmission that does not use a torque converter as a starting mechanism or an automatic transmission that automates a manual transmission, the accelerator pedal must be depressed. It is configured to generate a driving force when it is not.

In the automatic transmission control device that automates the manual transmission, a bypass clutch is provided between the input shaft and the output shaft, and hill hold control is performed by using this bypass clutch so that the shift position becomes the travel position. Some vehicles lock their wheels under certain conditions to prevent the vehicle from moving backwards.
Some dry single-plate clutch control devices suppress heat generation by increasing and correcting the connection speed of half-clutch control in accordance with the magnitude of the clutch heat quantity.
JP 2002-168333 A JP-A-2-195026

  By the way, in an automatic transmission that uses a dry single-plate type starting clutch as a starting mechanism in the past, if a creep condition is maintained for a long time in a traffic jam or an uphill road, abnormal heat generation occurs, a strange odor occurs, or a clutch disk There was a problem of wear.

  In order to solve this problem, it is known that the start clutch temperature of the start clutch is detected, and when the detected start clutch temperature exceeds the set value, the start clutch is released to protect the start clutch. However, when the starting clutch is released, there is a problem that the vehicle moves backward on the uphill road.

  In order to prevent the automatic transmission from retreating on an uphill road, in the automatic transmission in which the disengagement of acceleration force, which is a problem during gear shifting, is reduced by a sub-clutch installed separately from the starting clutch, mechanical gear meshing and sub- A device that generates double engagement of the clutch and prevents the vehicle from retreating when starting from an uphill road has been proposed in Patent Document 1 described above. Since the vehicle is prevented from retreating at the time of starting, and the countermeasure when the starting clutch heats up abnormally during traveling is not considered, improvement has been desired.

The present invention includes an input shaft coupled to the engine via a dry single-plate start clutch, an output shaft parallel to the input shaft, a plurality of transmission gear trains between the input shaft and the output shaft, And a sub-clutch that engages at least one transmission gear train. By controlling the engagement of the sub-clutch, a control device for an automatic transmission that is capable of shifting even when the starting clutch is engaged. A starting clutch temperature estimating unit for estimating the temperature, and when the starting clutch temperature estimated by the starting clutch temperature estimating unit is equal to or lower than a set value, the starting clutch is normally controlled and estimated by the starting clutch temperature estimating unit when higher and the vehicle than the starting clutch temperature set value is stopped only, with release controlling said starting clutch, engaging the sub clutch Characterized in that a control means for controlling.

  When the start clutch temperature is higher than the set value and the vehicle is in a stopped state, the automatic transmission control device of the present invention releases the start clutch and engages the sub-clutch. When the starting clutch is overheated, it is possible to prevent the vehicle from moving backward on the uphill road even if the starting clutch is released, and to protect the starting clutch, thereby improving the reliability of the automatic transmission. .

The present invention aims to prevent the vehicle from retreating on an uphill road even when the start clutch is released when the start clutch is overheated and to protect the start clutch and to prevent the start clutch temperature from being higher than a set value. When the vehicle is stopped, the starting clutch is released and the sub-clutch is engaged.
Embodiments of the present invention will be described in detail and specifically with reference to the drawings.

  1 to 6 show an embodiment of the present invention.

  In FIG. 6, reference numeral 2 denotes an engine mounted on a vehicle (not shown), and 4 denotes an automatic transmission connected to the engine 2 via a dry single-plate start clutch (main clutch) 6. The automatic transmission 4 is configured on the basis of a normal gear-type manual transmission, and includes a shift stage composed of a plurality of shift gear trains (a forward gear train and a reverse gear train). The gear position is automatically switched. The starting clutch 6 is disposed between the engine 2 and the automatic transmission 4, and includes an engine side coupling portion 6A fixed to the crankshaft 8 on the engine 2 side and a transmission coupling portion 6B on the automatic transmission 4 side. It is configured to be engageable and disengageable, and transmits input from the crankshaft 8 to an input shaft 10 to be described later.

  The automatic transmission 4 is provided with an input shaft (main shaft) 10 connected to the transmission side coupling portion 6B of the start clutch 6 and connected to the engine 2 via the start clutch 6. The output shaft (counter shaft) 12, the reverse (reverse) idler shaft 14, and the intermediate shaft (clutch shaft) 16 are provided in parallel.

  Between the input shaft 10 and the output shaft 12, there is provided a gear stage 18 composed of a plurality of transmission gear trains for transmitting the driving force of the input shaft 10 to the output shaft 12 at different gear ratios.

  The shift stage 18 is divided into a low speed stage 18-1, an intermediate stage 18-2, and a high speed stage 18-3 in order from the engine 2 side.

  The low speed stage 18-1 transmits rotation directly from the input shaft 10 to the output shaft 12, and is arranged on the engine 2 side, and includes a first speed gear train 20 and a second speed gear train 22. The medium speed stage 18-2 transmits the rotation via the intermediate shaft 16, and is arranged between the low speed stage 18-1 and the high speed stage 18-2 and includes a third speed gear train 24. The high speed stage 18-3 transmits rotation directly from the input shaft 10 to the output shaft 12, and is disposed on the side away from the engine 2, and includes a fourth speed gear train 26 and a fifth speed gear train 28. .

  The first-speed gear train 20 is provided with a first-speed drive gear 30 that is fixed to the input shaft 10 and a first-speed side engagement that meshes with the first-speed drive gear 30 and is rotatable on the output shaft 12. And a first speed driven gear 32 having a portion 32A.

  The second speed gear train 22 is provided so as to be rotatable on the output shaft 12 by meshing with the second speed drive gear 34 as a low speed stage input gear fixedly provided on the input shaft 10. And a second speed driven gear 36 as an output gear (low speed stage) provided with a second speed side engaging portion 36A.

  The third-speed gear train 24 includes a third-speed drive gear 38 as a medium-speed input gear provided integrally coupled to a second-speed driven gear 36 that is an output gear (low-speed gear) of the output shaft 12, A first intermediate gear 40 for rotation input that is meshed with the third-speed drive gear 38 and fixed to the intermediate shaft 16, and a second intermediate gear for rotation output that is rotatably provided to the intermediate shaft 16. 42. Therefore, the first intermediate gear 40 is driven by the third-speed drive gear 38 that is a medium-speed input gear that is integrally coupled to the second-speed driven gear 36 that is an output gear (low-speed gear).

  The fourth speed gear train 26 is rotatably provided on the input shaft 10, includes a fourth speed side engaging portion 44 </ b> A, and meshes with the second intermediate gear 42 to be fixed to the output shaft 12. It consists of a 4-speed drive gear 44 that is an input gear.

  The fifth-speed gear train 28 is fixed to the output shaft 12 by meshing with the fifth-speed drive gear 46 and the fifth-speed drive gear 46 that is rotatably provided on the input shaft 10 and includes the fifth-speed side engaging portion 46A. And a 5-speed driven gear 48 provided.

  A reverse gear train 50 is provided between the input shaft 10 and the output shaft 12. The reverse gear train 50 is provided with a reverse drive gear 52 fixed to the input shaft 10, and can be engaged with and disengaged from the reverse drive gear 52, and can slide on the reverse idler shaft 14 in the axial direction. And a reverse idler gear 54.

  The output shaft 12 includes a first-speed / second-speed synchronization (synchronization) mechanism as a transmission gear train switching mechanism for switching a plurality of transmission gear trains between the first gear train 20 and the second gear train 22. 56 is arranged. The first-speed / second-speed sync mechanism 56 is moved in the axial direction of the output shaft 12 on the first-speed / second-speed hub 58 provided on the output shaft 12 and fixed on the output shaft 12. The first-speed / second-speed sleeve 60 is a speed-change sleeve that selectively engages / disengages from the first-speed side engaging portion 32A of the first-speed driven gear 32 or the second-speed side engaging portion 36A of the second-speed driven gear 36. It is automatically controlled at the time of shift change. The first-speed / second-speed sleeve 60 is integrally provided with a reverse driven gear 62 that can mesh with the reverse idler gear 54.

  Further, the input shaft 10 is provided with a 4-speed / 5-speed sync (synchronization) as a transmission gear train switching mechanism for switching a plurality of transmission gear trains between the 4-speed gear train 26 and the 5-speed gear train 28. ) A mechanism 64 is provided. The 4-speed / 5-speed sync mechanism 64 is moved in the axial direction of the input shaft 10 on the 4-speed / 5-speed hub 66 fixed on the input shaft 10 and on the 4-speed / 5-speed hub 66. A fourth speed / fifth speed sleeve 68, which is another speed change sleeve that selectively engages / disengages from the fourth speed side engagement portion 44A of the fourth speed drive gear 44 or the fifth speed side engagement portion 46A of the fifth speed drive gear 46; It is automatically controlled at the time of shift switching.

  The intermediate shaft 16 is provided with a hydraulic clutch 70 as a sub-clutch that transmits a driving force through a driving path from the input shaft 10 to the output shaft 12. The hydraulic clutch 70 includes a plurality of clutch disks 72 that are connected and released by hydraulic pressure and fixedly arranged alongside the intermediate shaft 16, and a pressure plate 74 that contacts and separates from the clutch disks 72, and the second. The intermediate gear 42 is fixed and includes a clutch cover portion 76 that is rotatably provided on the intermediate shaft 16, and engages at least one transmission gear train.

  A differential 80 is connected to an end portion of the output shaft 12 closer to the engine 2 than the first-speed driven gear 32 via a final reduction mechanism (reduction mechanism) 78. The final reduction mechanism 78 includes a reduction gear 82 that is fixed to the output shaft 12 and a ring gear 84 that meshes with the reduction gear 82. The differential 80 includes a case portion 86 to which a ring gear 84 is fixed, and a pinion gear portion 88 connected to the case portion 86. The pinion gear portion 88 is provided with left and right drive shafts 90 and 90 to which left and right drive wheels (not shown) are attached. Therefore, the output shaft 12 is coupled to the drive wheels via the final reduction mechanism 78, the differential 80, and the drive shafts 90 and 90.

  This automatic transmission 4 engages the third gear with the hydraulic clutch 70 in order to eliminate the disconnection of the acceleration force at the time of shifting, and the start clutch 6 does not have to be disconnected at the time of shifting due to the engaged state of the hydraulic clutch 70. Also, it is possible to change the speed so that acceleration is not interrupted.

  As shown in FIG. 4, the starting clutch 6 is engaged / released by the operation of a starting clutch actuator 92 as a starting clutch releasing means. The hydraulic clutch 70 is engaged / released according to the hydraulic state of the hydraulic oil controlled by a hydraulic clutch actuator 94 as hydraulic clutch engaging means. Although not shown, the hydraulic pressure of the hydraulic clutch 70 is supplied by a hydraulic pump drive motor. When the hydraulic pressure becomes a set value or less by a hydraulic sensor or a hydraulic switch, the hydraulic pump drive motor is driven. Then, the hydraulic pressure is restored. Further, when the vehicle is stopped, for example, the double meshing by the engagement of the first gear and the engagement of the hydraulic clutch 70 makes it possible to prevent the reverse on the climbing path even when the brake pedal is not depressed.

  The starting clutch actuator 92 and the hydraulic clutch actuator 94 communicate with a control means (automatic transmission control device) 96 and are operated by a control signal from the control means 96.

  The control unit 96 includes a shift actuator 98 as a shift operation unit that performs a shift operation of a shift operation unit (not shown) of the automatic transmission 4, and a select operation unit that performs a selection operation of the shift operation unit. The select actuator 100 communicates with a failure warning means 102 that issues a warning when the automatic transmission 4 fails.

  Further, the control means 96 detects a throttle position of a shift position sensor 104 that detects the shift position of the automatic transmission 4, a vehicle speed sensor 106 that detects the speed of the vehicle, and a throttle valve (not shown). A throttle opening sensor 108 to detect, a brake switch 110 to detect the depression state of the brake pedal, an engine rotation sensor 112 as an engine rotation speed detecting means for detecting engine rotation speed, and an input side rotation speed of the automatic transmission 4 An input rotation sensor 114 as an input rotation speed detecting means for detecting the rotation speed of the input shaft 10 and a starting clutch stroke for detecting a starting clutch stroke as a clutch operation amount (engaged state and released state) of the starting clutch 6 A starting clutch stroke sensor 116 as a detecting means It is.

  In FIG. 4, when the control means 96 determines from the shift position switch 104, the throttle opening switch 108, and the brake switch 110 that the vehicle is in the starting state, the engagement force of the starting clutch 6 corresponding to the throttle opening is obtained. Further, a feedforward control amount for determining the control amount of the start clutch actuator 92 from the relationship between the start clutch stroke and the start clutch torque capacity, the engine rotation speed detected by the engine rotation sensor 112, and the input rotation detected by the input rotation sensor 114. The starting clutch actuator 92 is controlled by adding a feedback control amount that determines the control amount of the starting clutch actuator 92 so that the rotational difference (speed difference) from the speed becomes a predetermined value corresponding to the throttle opening, and the vehicle Control to start state. After the vehicle starts, when the vehicle speed detected by the vehicle speed sensor 106 is, for example, 15 km / h or more, the first clutch to the second gear are released without releasing the starting clutch 6 by engaging the hydraulic clutch actuator 94. Shift to. Further, when the vehicle is stopped and the throttle opening is fully closed and the shift position is in the forward (D) range or the reverse (R) range, the starting clutch 6 is controlled to obtain a predetermined driving force, and the torque converter Control is performed so as to obtain the same operability as the creep phenomenon of a general automatic transmission that uses the.

  When the starting clutch temperature is higher than a set value (abnormal heat generation determination temperature) and the vehicle is in a stopped state (the vehicle speed is substantially zero (0)), the control means 96 releases the starting clutch 6 and the hydraulic clutch 70. To engage.

  Therefore, as shown in FIG. 5, the control means 96 communicates with the engine rotation sensor 112 and the input rotation sensor 114 to calculate a rotation difference (differential rotation) from the engine rotation speed and the input rotation speed. A starting clutch torque calculating unit 96B that calculates the starting clutch torque capacity based on the starting clutch stroke by contacting the starting part 96A, the starting clutch stroke sensor 116, and the rotation difference calculating unit 96A and the starting clutch torque calculating unit 96B. A starting clutch temperature estimating unit 96C for estimating the starting clutch temperature by calculating the rotation difference and the starting clutch torque capacity, and contacting the starting clutch temperature estimating unit 96C, the starting clutch actuator 92 and the hydraulic clutch actuator 94 to start Starting clutch abnormal heat generation determination unit 9 for determining abnormal heat generation of the clutch 6 And a D is provided.

  In FIG. 5, the starting clutch temperature estimation unit 96C calculates the starting clutch temperature from the rotational difference between the engine rotational speed and the input rotational speed and the starting clutch torque capacity. That is, the rotational difference of the starting clutch 6 is calculated from the engine rotational speed and the input rotational speed, the starting clutch torque capacity is calculated from the starting clutch stroke, and the rotational difference and the starting clutch torque capacity are multiplied to obtain a predetermined time. The starting clutch temperature is calculated by integrating with a constant. When the starting clutch temperature becomes equal to or higher than a preset value (abnormal heat generation determination temperature), it is determined that the starting clutch 6 is in an abnormal heat generation state. When it is determined that this abnormal heat is generated, the starting clutch 6 is released by the starting clutch actuator 92 and the double engagement by the engagement of the hydraulic clutch 70 so that the mechanical gear is engaged by the hydraulic clutch actuator 94. To prevent the vehicle from moving backward.

  The relationship between the starting clutch stroke and the starting clutch torque capacity is shown in FIG. 2. The starting clutch torque capacity is considerably large when the starting clutch stroke is at the position S1, but at the position S2 where the starting clutch stroke is increased, the starting clutch stroke is increased. The clutch torque capacity becomes zero. Further, the relationship between the starting clutch temperature and time is shown in FIG. 3, and the starting clutch temperature gradually increases until time T. When the starting clutch temperature reaches a set value (abnormal heat generation determination temperature) at time T, the starting clutch temperature starts. Abnormal heat generation of the clutch 6 is determined, and the starting clutch temperature is lowered by releasing the starting clutch 6.

  Next, the operation of this embodiment will be described based on the flowchart of FIG.

  When the control unit 96 starts a program for controlling the automatic transmission 4 (step 202), first, the rotational difference (differential rotation) of the starting clutch 6 is calculated as the rotational difference between the engine rotational speed and the input rotational speed ( Step 204).

  Next, the starting clutch torque capacity is calculated from the relationship between the starting clutch stroke and the starting clutch torque capacity (see FIG. 2) (step 206).

  Then, the heat generation amount of the starting clutch 6 is calculated as differential rotation (rotational difference) × starting clutch torque capacity (step 208), and it is determined whether or not the heat generation amount is zero (0) (step 210).

  When this step 210 is NO, the heat generation amount is not zero (0), and the start clutch temperature is estimated by multiplying the heat generation amount by a predetermined time constant k and adding up and adding the previous temperature ( Step 212).

  However, if this step 210 is YES, the amount of generated heat is zero (0), and the degree of decrease in the starting clutch temperature is obtained in advance by experiment, that is, the heat release temperature is subtracted from the previous temperature to determine the starting clutch temperature. Is settled (step 214).

  After the processing of step 212 and step 214, it is determined whether or not the starting clutch temperature has exceeded a set value (abnormal heat generation determination temperature) (step 216).

  If this step 216 is YES, the starting clutch 6 is released (step 218), and it is further determined whether or not the vehicle speed is substantially zero (0) (step 220).

  If this step 220 is YES, the hydraulic clutch 70 is engaged (step 222), and double meshing with the engagement of a mechanical gear train (for example, first gear) is generated to prevent the vehicle from moving backward. Then, the program is terminated (step 224).

  On the other hand, if the step 216 is NO and the step 220 is NO, the program is immediately terminated (step 224).

  The process of the flowchart of FIG. 1 is repeatedly performed at a constant cycle, for example, every 10 msec cycle.

  As a result, when the estimated starting clutch temperature is higher than the set value and the vehicle is in a stopped state, the starting clutch 6 is released and the hydraulic clutch 70 is engaged. Therefore, when the vehicle is stopped, the starting clutch 6 When the vehicle overheats, the vehicle can be prevented from retreating on the uphill road even when the starting clutch 6 is released, and the starting clutch 6 can be protected, thereby improving the reliability of the automatic transmission 2. it can.

  Further, the starting clutch temperature estimation unit 96C calculates the starting clutch temperature from the rotational difference between the engine speed and the input rotational speed and the starting clutch torque capacity, so that the detecting means for directly detecting the starting clutch temperature. Therefore, the number of parts can be reduced, the cost can be reduced, and the space can be saved.

  That is, in this embodiment, a dry single-plate start clutch 6 is used as a start mechanism, and a gear engagement at a predetermined gear stage is performed by the hydraulic clutch 70, thereby eliminating an automatic transmission at the time of shifting. In the machine 2, when the vehicle is stopped, the start clutch temperature is detected, and when the start clutch temperature exceeds a set value, the start clutch 6 is released and the hydraulic clutch 70 is engaged. Thereby, when the starting clutch 6 is abnormally overheated, the starting clutch 6 is released to protect the starting clutch 6, and the vehicle can be prevented from retreating on the uphill road.

  Further, according to the present invention, depending on the situation on the uphill road, for example, on the uphill, the forward gear is meshed, while on the downhill, the reverse gear is meshed, which is more effective than the movement of the vehicle. Can be prevented.

  When the starting clutch temperature is higher than the set value and the vehicle is in a stopped state, releasing the starting clutch and engaging the sub-clutch can be applied to other transmissions.

It is a flowchart of control of an automatic transmission. It is a figure which shows the relationship between a starting clutch stroke and a starting clutch torque capacity. It is a figure which shows the emitted-heat amount of a starting clutch. It is a block diagram of the control apparatus of an automatic transmission. It is a block diagram of the control means of an automatic transmission. It is a skeleton figure of an automatic transmission.

Explanation of symbols

2 Engine 4 Automatic transmission 6 Start clutch 8 Crankshaft 10 Input shaft 12 Output shaft 16 Intermediate shaft 18 Shift stage 20 1st speed gear train 22 2nd speed gear train 24 3rd speed gear train 26 4th speed gear train 28 5 First gear train 56 First gear / second gear sync mechanism 60 First gear / second gear sleeve 64 Fourth gear / fifth gear sync mechanism 68 Fourth gear / fifth gear sleeve 70 Hydraulic clutch 92 Starting clutch actuator 94 Hydraulic clutch actuator 96 Control means 104 Shift Position switch 106 Vehicle speed sensor 108 Throttle opening sensor 110 Brake switch 112 Engine rotation sensor 114 Input rotation sensor 116 Start clutch stroke sensor

Claims (1)

An input shaft connected to the engine via a dry single-plate start clutch, an output shaft parallel to the input shaft, a plurality of transmission gear trains between the input shaft and the output shaft, and at least one speed change gear And a sub-clutch that engages the gear train. By controlling the engagement of the sub-clutch, the temperature of the starting clutch is estimated in a control device for an automatic transmission that can change speed even when the starting clutch is engaged. A starting clutch temperature estimating unit, and when the starting clutch temperature estimated by the starting clutch temperature estimating unit is below a set value, the starting clutch is normally controlled, and the starting clutch temperature estimated by the starting clutch temperature estimating unit is when higher and the vehicle than the set value is stopped only, with release controlling said starting clutch, engaging control the sub clutch control Control apparatus for an automatic transmission, characterized in that a means.

Images