JP2005351327A - Shift controller for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shift controller for a vehicle maintaining the durability of a frictionally engaging means by limiting a gear ratio in starting based on a load energy amount acting on the frictionally engaging means. <P>SOLUTION: This shift controller comprises a gear type automatic transmission 3 with an auxiliary transmission, the frictionally engaging means 2 transmitting the rotation of an engine 1 to the automatic transmission, and a control means 11 controlling the engagement of the frictionally engaging means. The gear ratio in starting is selected from at least a high speed gear ratio and a low speed gear ratio by a driver. The control means 11 comprises load energy amount calculation means S15, S17, and S18 calculating an energy amount loaded on the frictionally engaging means and gear ratio changing means S3 and S4 changing the gear ratio in starting based on the calculated load energy amount. When the high speed gear ratio is selected as the gear ratio in starting and the calculated load energy amount exceeds a specified value, the selected high speed side gear ratio is changed to the low speed gear ratio. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a shift control device for an automatic transmission, and more particularly to a vehicle shift control device that electrically shifts a shift operation of a transmission in which a sub-transmission is combined with a main transmission using an electric signal.

2. Description of the Related Art Conventionally, an automatic transmission has been proposed in which a mechanical clutch and a synchronous mesh gear type transmission are electronically controlled to automatically shift to a traveling speed corresponding to a traveling state (see Japanese Patent Application Laid-Open No. 2005-228867). In this automatic transmission, since a fluid clutch (torque converter) is not interposed in the driving force transmission system from the engine to the driving wheels, the driving force transmission efficiency is high and the fuel consumption can be improved. Moreover, since there is no slip feeling peculiar to a fluid clutch, drivability can be improved.
Japanese Utility Model Publication No. 2004-125003

  In the aforementioned automatic transmission, a friction clutch is installed between the engine and the automatic transmission to control the power flow. In the so-called half-clutch state when the friction clutch is engaged, load energy acting on the friction clutch is generated, and the generation of load energy is particularly large at the start.

  In such an automatic transmission, the gear stage at the time of starting is set by the driver, and the gear stages that can be used at the time of starting are limited to a plurality of predetermined gear stages. When the driver starts, when the gear set on the high speed side is set out of the settable gear stages and the vehicle starts, the friction clutch is not completely engaged when the vehicle is in a loaded state or when starting on an uphill road. A so-called half-clutch state in which there is a difference between the engine rotation speed and the transmission rotation speed becomes longer, and the load acting on the friction clutch increases. For this reason, the subject that durability of a friction clutch falls arises.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a vehicle transmission control device that selects a gear stage at the time of starting so as to appropriately control the amount of load energy acting on the friction clutch and improves the durability of the friction clutch. .

  A first invention provides an engine as a drive source, a gear-type automatic transmission having a sub-transmission that changes the rotational speed of the engine to a predetermined rotational speed, and transmits the rotation of the engine to the automatic transmission. Friction engagement means, and control means for controlling the shift of the automatic transmission and the engagement of the engagement means in accordance with the running state of the vehicle and the driver's request, the gear ratio at the start is at least on the high speed side In the vehicle selected by the driver from the gear ratio on the low speed side, the control means, based on the load energy amount calculating means for calculating the amount of energy loaded on the friction engagement means, and the calculated load energy amount, A gear ratio changing means for changing the gear ratio at the time of starting, a gear ratio on the high speed side is selected as the gear ratio at the time of starting, and is selected when the calculated load energy amount exceeds a predetermined value. Gi of the high speed side And changing the ratio to the gear ratio of the low speed side.

  According to a second aspect of the present invention, there is provided an engine as a drive source, a gear-type automatic transmission having a sub-transmission that changes the rotational speed of the engine to a predetermined rotational speed, and transmission of the rotation of the engine to the automatic transmission. Friction engagement means, and control means for controlling the shift of the automatic transmission and the engagement of the engagement means in accordance with the running state of the vehicle and the driver's request, the gear ratio at the start is at least on the high speed side In the vehicle selected by the driver from the gear ratio on the low speed side, the control means includes load energy amount calculation means for calculating the amount of energy loaded on the friction engagement means, and the calculated load energy amount is a predetermined value. It is equipped with a frequency measurement means that counts the number of times above and a gear ratio changing means that changes the gear ratio at the start based on the measured number, and the gear ratio on the high speed side is selected as the gear ratio at the start , Said performance It has been if the number of times the load amount of energy exceeds a predetermined value is equal to or more than the predetermined number of times, and changes the gear ratio of the selected high speed side gear ratio of the low speed side.

  According to a third invention, in the first or second invention, the control means includes a fuel injection amount to the engine, a rotation speed of the engine, and a rotation speed of the input shaft of the automatic transmission connected to the friction engagement means. Based on the above, the amount of energy loaded on the friction engagement means is calculated.

  In a fourth aspect based on the third aspect, the control means is configured such that the rotational speed of the input shaft of the automatic transmission is not 0, the rotational speed of the engine, the rotational speed of the input shaft of the automatic transmission, The amount of energy loaded on the friction engagement means during the difference is calculated.

  Therefore, in the first and second aspects of the invention, the gear ratio at the start can be optimally set according to the amount of load energy acting on the friction engagement means, so that excessive load energy acts on the friction engagement means. This makes it possible to maintain the durability of the engaging means.

  In FIG. 1, 1 is an engine, 2 is a friction clutch (friction engagement means), 3 is a synchronous mesh transmission, and the output shaft of the transmission 3 is a drive shaft (for example, a rear axle) via a propeller shaft (not shown). ). A fuel injection pump for supplying fuel to the engine 1 is provided with an electronic governor device 1A for controlling the fuel injection amount (rack position), and a clutch for operating the clutch 2 that transmits the power of the engine 1 to the transmission 3 A booster 2A is provided, and the transmission 3 is provided with a gear shift unit 3A for shifting a gear train constituting the transmission. Reference numeral 27 denotes a control valve of the clutch booster 2A, and 31 denotes an air tank, which supplies operating pressure (compressed air) to the actuators constituting the gear shift unit 3A and the clutch booster 2A.

  As shown in FIG. 2, the transmission 3 includes a splitter gear train 40B as a sub-transmission on the input side and output side of a main transmission gear train 40A (Zm1-Zc1 to Zm3-Zc3, ZmR-ZcR) as a main transmission. (Zm4-Zc4, Zm5-Zc5) and range gear train 40C (Zr1-Zcr1, Zr2-Zcr2) are connected to each other. Hereinafter, the configuration of the transmission 3 will be described.

  A splitter gear Zm5 for switching the splitter gear train 40B to a high speed stage is freely arranged on the input shaft 42 for inputting the output of the engine 1, and a synchronizer hub 44A constituting the synchromesh mechanism 44 is provided at the tip thereof. Fixed. The main shaft 46 disposed coaxially with the input shaft 42 includes a drive gear Zm4, a third speed gear Zm3, a second speed gear Zm2, a first speed gear Zm1 and a reverse gear ZmR that constitute each gear stage of the main transmission gear train 40A. Are arranged freely to rotate, and a range high gear Zr1 for switching the range gear train 40C to a high speed stage is fixed to the tip thereof. The main shaft 46 between the drive gear Zm4 and the third speed gear Zm3, the second speed gear Zm2 and the first speed gear Zm1, and the first speed gear Zm1 and the reverse gear ZmR has a synchronizer hub 44A that constitutes the synchromesh mechanism 44, respectively. Is fixed.

  On the other hand, the main counter shaft 48 arranged in parallel with the input shaft 42 and the main shaft 46 has a counter gear which is always meshed with the splitter gear Zm5, the drive gear Zm4, the third speed gear Zm3, the second speed gear Zm2 and the first speed gear Zm1. Splitter gear Zc5, counter drive gear Zc4, counter third speed gear Zc3, counter second speed gear Zc2 and counter first speed gear Zc1 are fixed. A counter reverse gear ZcR that is always meshed with the reverse gear ZmR is fixed to the main counter shaft 48 via a reverse idler gear ZmR1.

  A range low gear Zr2 for switching the range gear train 40C to a low speed stage is freely arranged on the output shaft 50 which is arranged coaxially with the main shaft 46 and connected to a propeller shaft (not shown), and has a synchromesh at one end thereof. A synchronizer hub 44A constituting the mechanism 44 is fixed. A range counter high gear Zcr1 and a range counter low gear Zcr2, which are always meshed with the range high gear Zr1 and the range low gear Zr2, are fixed to the range counter shaft 52 arranged in parallel with the output shaft 50, respectively.

  As shown in FIG. 2, the transmission 3 includes main gear trains Zm1-Zc1 to Zm3-Zc3, ZmR-ZcR (third forward speed, first reverse speed) of the main transmission, and a split gear train of the sub-transmission arranged on the engine side. Zm4-Zc4, Zm5-Zc5 (Low or lower, simply L, Hi or lower, simply H), and sub gear range gear trains Zr1-Zcr1, Zr2-Zcr2 (H, L), which are also disposed on the propeller shaft side. Yes, 12 forward gears (minimum speed) by switching the main gear trains Zm1-Zc1 to Zm3-Zc3, switching the split gear trains Zm4-Zc4, Zm5-Zc5, and switching the range gear trains Zr1-Zcr1, Zr2-Zcr2. 1L on the side to 6H on the fastest side).

  As detection means necessary for vehicle shift control, an engine rotation speed sensor 29 that detects the engine rotation speed, an accelerator opening sensor 28 that detects the amount of depression of the accelerator pedal 7 (a required amount of the accelerator opening), and a stroke of the clutch 2 Clutch stroke sensor 22 for detecting position, shift position of transmission 3 (selected positions of split gear trains Zm4-Zc4, Zm5-Zc5, selected positions of main gear trains Zm1-Zc1-Zm3-Zc3, ZmR-ZcR, range gear train Zr1- Gear position switch (incorporated in gear shift unit 3A) for detecting Zcr1, Zr2-Zcr2), vehicle speed sensor 21 for detecting rotational speed from the output shaft of transmission 3, and main countershaft from main gear Zm1 of transmission 3 Times The main counter shaft rotation speed sensor 23 for detecting the speed, range counter shaft rotation speed sensor 17 for detecting the rotational speed of the range counter shaft from the range gear Zr1 transmission 3 is provided.

  In order to switch between automatic control of engagement control of the clutch 2 and manual control based on the manual operation of the driver, clutch pedal switches 24 and 25 for detecting an initial position (release state) and an operating position (depression state) of the clutch pedal are provided. It is done. A shift lever unit 4 is provided in the cab as a shift instruction unit of the transmission 3 and outputs a shift instruction signal (including a neutral instruction signal) corresponding to the shift position of the shift lever 4A. In addition, a switch 5 (mode changeover switch) for selecting a manual shift mode in which the vehicle is shifted according to the driver's shift instruction and an automatic shift mode that is automatically performed according to the driving state is shifted. Provided on the knob of the lever 4A. The cab is provided with a display unit 13 for displaying the shift position of the transmission 3 and the like, and a brake pedal switch 26 for detecting depression of a brake pedal (not shown). 13A is an alarm means (for example, a buzzer).

  The transmission control unit (TCU) 11 and the engine control unit (ECU) 12 are responsible for the shift control, and these are connected by serial communication (LAN). In the TCU 11, when the mode changeover switch 5 is in the manual shift mode, the shift lever unit 4 shifts to the target position corresponding to the shift instruction signal when the shift instruction signal of the shift lever unit 4 does not coincide with the shift position based on the gear position switch of the transmission 3. Generates a request (shift command). When the mode switch 5 is in the automatic shift mode, a target stage is obtained based on a preset shift map from the detection signal of the accelerator opening sensor 28 and the detection signal of the vehicle speed sensor 21, and this target stage is the gear position switch of the transmission 3. A shift request (shift command) to the target stage is generated when it does not coincide with the shift position based on.

  The shift control is activated by the generation of these shift requests, and the TCU 11 and the ECU 12 control the electronic governor device 1A, the clutch booster 2A, and the gear shift unit 3A in order to smoothly perform the gear shift to the target position at that time. In FIG. 2, split gear trains Zm4-Zc4, Zm5-Zc5 are switched from L to H or H to L each time the transmission 3 changes gear by gear, while range gear trains Zr1-Zrc1, Zr2-Zcr2 are Only when the transmission 3 shifts from 1L to 2H to 3L to 6H or vice versa, it switches from L to H or from H to L.

  For shift control that does not involve switching of the range gear trains Zr1-Zrc1, Zr2-Zcr2, when a shift command (shift request) is generated, the accelerator opening of the engine 1 (rack position of the fuel injection pump) is reduced to a no-load state. Then, the clutch 2 is disconnected. When the disconnection of the clutch 2 is detected, the main gear trains Zm1-Zc1 to Zm3-Zc3 are set to neutral (gear disengagement), and at the same time, the split gear trains Zm4-Zc4 and Zm5-Zc5 are switched, while the engine speed is changed. Control is performed to a target rotation (synchronous rotation of the gear stage to be geared of the main transmission) calculated from the rotation of the range counter shaft and the gear ratio (ratio) after completion of the transmission 3 transmission. In accordance with this, the main gear train Zm1 corresponding to the shift command is controlled while the main counter shaft rotation of the transmission 3 is controlled to the target rotation by the double clutch operation of the clutch 2 (clutch disengagement → clutch engagement → clutch disengagement). -Gears Zc1-Zm3-Zc3. Thereafter, when the gear engagement is completed, the clutch 2 is connected and the engine rotation control is switched to normal control corresponding to the accelerator opening.

  The transmission 3 to which the present invention is applied is configured as described above. Next, the configuration of the TCU (control means) 11 that performs the start gear position control of the present invention will be described using the block diagram shown in FIG.

  The operating state of the transmission 3 is input to the TCU 11 from each sensor. Specifically, the rotational speed of the engine 1 is input from the engine rotational speed sensor 29, and the fuel injection amount of the engine 1 is input from the ECU 12. The rotation speed of the main counter shaft is input from the main counter shaft rotation speed sensor 23, the accelerator opening is input from the accelerator opening sensor 28, and the shift lever position is input from the gear position switch (3A). Further, a signal of a gear position sensor 62 that detects the position of the fixed gear of the splitter gear train 40B is input.

  Based on each input signal, the TCU 11 switches the split gear train and the range gear train and engages the clutch 2, and performs start gear stage limit control for limiting the gear stage when starting the vehicle.

  FIGS. 4-1 and FIGS. 4-2 are flowcharts illustrating the contents of the starting gear stage limit control according to the present invention. In this embodiment, only the 1H and 2L gear ratios that are the second and third gear ratios from the low speed side among the gear ratios that can be selected as the gear stage at the time of starting will be described below. Normally, the driver selects 2L as the gear stage when starting on a flat road without loading, and the gear stage 1H is selected when the vehicle is loaded or when starting on an uphill road. However, it is possible to select the gear stage 2L even when starting on an uphill road. In such a case, the half-clutch state becomes longer, the load acting on the friction clutch 2 becomes larger, and the durability of the friction clutch 2 is increased. There is a problem of lowering. Therefore, in the present invention, when the durability of the friction clutch 2 is lowered, the gear stage at the start is limited to the low speed side gear stage so that the load energy amount acting on the friction clutch is suppressed. is there.

  First, in steps S1 and S2, the position of the shift lever 4A is read, and it is determined whether or not the position is in the travel range. If it is not in the travel range, it is determined that the vehicle is not in a starting state, and the process returns to step S1.

  In step S3, the number of times that a load greater than or equal to a predetermined value set in advance through experiments or the like from the viewpoint of durability of the friction clutch 2 is applied to the friction clutch 2 is compared with the predetermined number of times. Here, when a load greater than or equal to a predetermined value acts on the friction clutch 2 for a predetermined number of times, wear of the friction clutch 2 proceeds, and durability of the clutch 2 decreases. Therefore, when a load of a predetermined value or more is applied a predetermined number of times or more, the gear stage at the time of starting is limited and changed to a lower gear stage.

  In this embodiment, when the determination condition is satisfied, the process proceeds to step S4, and the gear stage at the start is set to the gear stage 1H regardless of the driver's selection. On the other hand, if the determination condition is not satisfied, the process proceeds to step S5 because there is no fear of the durability of the friction clutch 2 being lowered, and the gear stage at the start is set to the high speed gear stage 2L according to the driver's selection. For example, even if the driver's selection is 2L, if the load state of the friction clutch 2 matches the condition of step 3, the load acting on the friction clutch 2 is reduced by setting the gear stage to 1H, and the friction clutch 2 suppresses a decrease in durability. Alternatively, the driver may be notified that the gear stage is performing control different from the required gear stage. Here, steps S3 and S4 correspond to the gear ratio changing means.

  After setting the gear position, the shift position is read in steps S6 and S7, and it is determined whether the shift position is neutral, that is, whether the driver has stopped starting. In the case of neutral, the process returns to step S1. When the travel range is other than neutral, the process proceeds to step S8, and the accelerator opening is read from the accelerator opening sensor 28. In step S9, it is determined whether the accelerator opening is not 0. If the accelerator opening is 0, the process returns to step S6. If not, the process proceeds to step S10.

  In step S10, the load energy amount Q acting on the friction clutch 2 is canceled to zero. Next, in step S11, the rotational speed of the input shaft 42 and the difference between the rotational speed of the engine and the rotational speed of the input shaft are calculated to determine whether or not the friction clutch 2 is in the half-clutch state. If the friction clutch 2 is completely engaged or if the rotation of the input shaft 42 is not transmitted, the process proceeds to step S13 to determine whether or not the start is completed.

  If it is a half-clutch state, the engine rotational speed B, the main countershaft rotational speed, and the position of the splitter gear train 40B are read in the next step S12 and step S14, and the position of the splitter gear train 40B and the position of the main countershaft in step S15. The rotational speed C of the input shaft 42 is calculated from the rotational speed.

  In the next step S16, the engine rotational speed B is read, and the rotational speed C of the input shaft 42 is calculated. In step S17, the load energy amount dQ acting on the friction clutch 2 is calculated from these and the fuel injection amount A by the following equation. To do.

  In subsequent step S18, the integrated value Q of the energy amount up to the previous calculation is added to the calculated energy amount dQ, and the process returns to the half-clutch determination in step S14 as a new integrated energy amount Q. By repeatedly calculating and integrating this calculation during the half-clutch state, the accumulated energy amount Q acting on the friction clutch 2 in the half-clutch state can be calculated. Here, steps S15, 17 and 18 correspond to the load energy amount calculation means in the claims.

  Returning to the half-clutch determination in step S11, if this determination is not in the half-clutch control, the process proceeds to the start-end determination in step S13, and the start is made on condition that the rotation speed of the engine 1 and the rotation speed of the input shaft 42 match. It is determined that the process has ended. When there is a difference between the engine speed and the input shaft 42 (the input shaft 42 is considered to be 0 and the vehicle has not started moving yet), the start has not ended. Return to step S11. If it is determined that the start has been completed, the process proceeds to step S19, where it is determined whether or not the cumulative energy amount Q of the friction clutch 2 is equal to or greater than a predetermined value. If it is equal to or greater than the predetermined value, the process proceeds to step S20. The number of times obtained is incremented once and the process proceeds to step S21. If the integrated energy amount Q is less than the predetermined value in step S19, the process proceeds to step S21. Here, step S20 corresponds to the number-of-times counting means in the claims.

  In step S21, it is determined from the output of the vehicle speed sensor 21 whether or not the vehicle is stopped. If the vehicle is running, the determination is repeated until the vehicle stops, and if the vehicle stops, the process returns to step 1.

  As described above, the number of times that the load acting on the friction clutch 2 exceeds a predetermined energy when the high-speed gear stage is selected from among the gear stages that can be selected at the start of the vehicle is stored. Is over a predetermined number of times, the use of the selected high-speed gear stage is prohibited and control is performed to limit the use of the low-speed gear stage. The durability of the friction clutch 2 can be extended.

  FIGS. 5A and 5B are other flowcharts for explaining the contents of the starting gear stage limit control according to the present invention. In this embodiment, the point of difference from the control content shown in FIG. 4 is that when the integrated energy amount Q of the load acting on the friction clutch 2 is equal to or greater than a predetermined value, a flag is set and the flag is turned on / off. This is the point that the limit control of the gear stage at the time of starting is performed.

  First, in step S0, the flag is set to off.

  Next, in steps S1 and S2, the position of the shift lever 4A is read, and it is determined whether or not the position is in the travel range. If it is not in the travel range, it is determined that the vehicle is not in a starting state, and the process returns to step S1.

  In step S2 ′, it is determined whether or not a flag to be set is turned on when a load of a predetermined value or more set in advance through experiments or the like is applied to the friction clutch from the viewpoint of durability of the friction clutch 2. If it is on, the process proceeds to step S4. If it is off, the process proceeds to step S5.

  In this embodiment, when the determination condition is satisfied, the process proceeds to step S4, and the gear stage at the start is set to the gear stage 1H regardless of the driver's selection. On the other hand, if the determination condition is not satisfied, the process proceeds to step S5 because there is no fear of the durability of the friction clutch 2 being lowered, and the gear stage at the start is set to the high speed gear stage 2L according to the driver's selection. For example, even if the driver's selection is 2L, if the load state of the friction clutch 2 matches the condition of step 3, the load acting on the friction clutch 2 is reduced by setting the gear stage to 1H, and the friction clutch 2 suppresses a decrease in durability. Alternatively, the driver may be notified that the gear stage is performing control different from the required gear stage. Here, steps S3 and S4 correspond to the gear ratio changing means.

  After setting the gear position, the shift position is read in steps S6 and S7, and it is determined whether the shift position is neutral, that is, whether the driver has stopped starting. In the case of neutral, the process returns to step S1. When the travel range is other than neutral, the process proceeds to step S8, and the accelerator opening is read from the accelerator opening sensor 28. In step S9, it is determined whether the accelerator opening is not 0. If the accelerator opening is 0, the process returns to step S6. If not, the process proceeds to step S10.

  In step S10, the load energy amount Q acting on the friction clutch 2 is canceled to zero. Next, in step S11, the rotational speed of the input shaft 42 and the difference between the rotational speed of the engine and the rotational speed of the input shaft are calculated to determine whether or not the friction clutch 2 is in the half-clutch state. If the friction clutch 2 is completely engaged or if the rotation of the input shaft 42 is not transmitted, the process proceeds to step S13 to determine whether or not the start is completed.

  If it is a half-clutch state, the engine rotational speed B, the main countershaft rotational speed, and the position of the splitter gear train 40B are read in the next step S12 and step S14, and the position of the splitter gear train 40B and the position of the main countershaft in step S15. The rotational speed C of the input shaft 42 is calculated from the rotational speed.

  In the next step S16, the engine rotational speed B is read, and the rotational speed C of the input shaft 42 is calculated. In step S17, the load energy amount dQ acting on the friction clutch 2 is calculated from these and the fuel injection amount A by the following equation. To do.

  In subsequent step S18, the integrated value Q of the energy amount up to the previous calculation is added to the calculated energy amount dQ, and the process returns to the half-clutch determination in step S14 as a new integrated energy amount Q. The accumulated energy amount Q acting on the friction clutch 2 in the half-clutch state can be calculated by repeatedly calculating and accumulating this calculation in the half-clutch state. Here, steps S15, 17 and 18 correspond to the load energy amount calculation means in the claims.

  Returning to the half-clutch determination in step S11, if this determination is not in the half-clutch control, the process proceeds to the start-end determination in step S13, and the start is made on condition that the rotation speed of the engine 1 and the rotation speed of the input shaft 42 match. It is determined that the process has ended. When there is a difference between the engine speed and the input shaft 42 (the input shaft 42 is considered to be 0 and the vehicle has not started moving yet), the start has not ended. Return to step S11. If it is determined that the start has been completed, the process proceeds to step S19, where it is determined whether or not the accumulated energy amount Q of the friction clutch 2 is equal to or greater than a predetermined value. If it is equal to or greater than the predetermined value, the process proceeds to step S22. A flag to be set when the acting load is equal to or greater than a predetermined value is turned on. If the load is less than the predetermined value, the process proceeds to step S23, the flag is turned on or off, and the process proceeds to step S24.

  In step S24, it is determined from the output of the vehicle speed sensor 21 whether or not the vehicle is stopped. If the vehicle is running, the determination is repeated until the vehicle stops, and if the vehicle stops, the process returns to step 1.

  As described above, when the high speed gear stage is selected from among the gear stages that can be selected at the start of the vehicle, when the load acting on the friction clutch 2 exceeds a predetermined energy, the selected high speed side gear stage is selected. Since the control to prohibit the use of the gear stage and restrict the use of the gear stage on the low speed side is performed, the load acting on the friction clutch 2 can be reduced, and the durability of the friction clutch 2 can be extended. Can do.

  In the above embodiments, the description has been made using two gear stages, high and low, as selectable gear stages at the time of starting. However, by using the same criteria, more usable gear stages can be set. It is also possible to do.

  Since the durability of the friction clutch can be maintained, it is useful for an automatic transmission having a sub-transmission.

It is a whole lineblock diagram showing an embodiment of this invention. It is a block diagram of an automatic transmission. It is a block diagram of TCU which performs gear ratio restriction | limiting control at the time of start of this invention. It is a flowchart of the gear ratio limitation control at the time of start of the present invention. It is a flowchart of the gear ratio limitation control at the time of start of the present invention. It is a flowchart of the other gear ratio limitation control at the start of the present invention. It is a flowchart of the other gear ratio limitation control at the start of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine 1A Electronic governor device 2 Friction clutch 2A Clutch booster 3 Automatic transmission 3A Gear shift unit 4 Shift lever unit 4A Shift lever 11 Transmission control unit 12 Engine control unit 13 Display unit 13A Buzzer 17 Splitter gear rotation sensor 21 Vehicle speed sensor 22 Clutch stroke Sensor 23 Gear rotation sensor 24, 25 Clutch switch 26 Brake pedal switch 28 Accelerator opening sensor 29 Engine rotation sensor 32 Range countershaft 40A Main transmission 40B Splitter (sub transmission)
40C range 42 input shaft 44 synchromesh mechanism 44A synchronizer hub 46 main shaft 48 main counter shaft 50 output shaft 60 main position sensor 62 splitter position sensor 64 range position sensor

Claims (4)

An engine as a drive source,
A gear-type automatic transmission including a sub-transmission that changes the rotational speed of the engine to a predetermined rotational speed using at least a gear ratio between the high speed side and the low speed side;
Friction engagement means for transmitting rotation of the engine to the automatic transmission;
Control means for controlling the shift of the automatic transmission and the engagement of the engagement means according to the running state of the vehicle and the request of the driver;
In a vehicle in which a driver selects a gear ratio at the time of starting from at least the high speed side and the low speed side gear ratio of the sub-transmission,
The control means includes
Load energy amount calculating means for calculating the amount of energy loaded on the friction engagement means;
Gear ratio changing means for changing the gear ratio at the start based on the calculated load energy amount,
The gear ratio on the high speed side is selected as the gear ratio at the time of start, and when the calculated load energy amount exceeds a predetermined value, the gear ratio on the high speed side selected is changed to the gear ratio on the low speed side. A shift control apparatus for a vehicle, characterized by being changed. An engine as a drive source,
A gear-type automatic transmission including a sub-transmission that changes the rotational speed of the engine to a predetermined rotational speed using at least a gear ratio between the high speed side and the low speed side;
Friction engagement means for transmitting rotation of the engine to the automatic transmission;
Control means for controlling the shift of the automatic transmission and the engagement of the engagement means according to the running state of the vehicle and the driver's request;
In a vehicle in which a driver selects a gear ratio at the time of starting from at least the high speed side and the low speed side gear ratio of the sub-transmission,
The control means includes
Load energy amount calculating means for calculating the amount of energy loaded on the friction engagement means;
Number-of-times measuring means for counting the number of times the calculated load energy amount is equal to or greater than a predetermined value;
Gear ratio changing means for changing the gear ratio at the start based on the measured number of times,
If the gear ratio on the high speed side is selected as the gear ratio at the time of start and the number of times the calculated load energy amount exceeds a predetermined value is a predetermined number or more, the selected gear ratio on the high speed side is A vehicular speed change control device, wherein the gear ratio is changed to a low gear ratio.   The control means determines the amount of energy applied to the friction engagement means based on the fuel injection amount to the engine, the rotation speed of the engine, and the rotation speed of the input shaft of the automatic transmission connected to the friction engagement means. The vehicle shift control device according to claim 1, wherein the shift control device for a vehicle is calculated. The control means is configured so that the rotational speed of the input shaft of the automatic transmission is not zero and the frictional engagement is performed while a difference between the rotational speed of the engine and the rotational speed of the input shaft of the automatic transmission is occurring. 4. The vehicle shift control device according to claim 3, wherein an amount of energy loaded on the means is calculated.

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