JP2006242112A - Drive force control device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To materialize drive force intended by a driver even when a vehicle is started with a high gear side shift gear position without forming a first gear position at a time of vehicle start. <P>SOLUTION: ECU executes a program performing a step S400 raising engine torque and a step S500 starting the vehicle with higher gear side of gear position than first gear position when first gear start demand is detected (Yes in S100) and first gear position fail judgment is detected (Yes in S200). ECU executes a program not performing a step S800 releasing torque raise process until completion of shift to other gear position (Yes in S700) even if first gear position fail judgment release is detected (Yes in S600). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a driving force control device for a vehicle equipped with an automatic transmission, and more particularly to a driving force control device for a vehicle when a shift gear for starting the vehicle cannot be realized.

Usually, in an automatic transmission, control is performed so that a plurality of friction engagement elements are selectively fastened to form a desired transmission gear stage. Japanese Patent Laid-Open No. 2000-65203 (Patent Document 1) is provided with a pressure switch for detecting the hydraulic fluid pressure of these friction engagement elements, and detects the interlock of the automatic transmission from the combination of the states of these pressure switches. To disclose a technique for interlocking measures. In this Patent Document 1, when a failure occurs in a solenoid or a direct acting valve related to a friction engagement element at the first speed used at the time of starting, the second speed that is not related to the engagement of the friction engagement element is forcibly selected. Thus, it is disclosed that the vehicle is prevented from falling into a state that does not require traveling.
JP 2000-65203 A

  However, if the gear position at the time of start is not the first speed and a gear position (second speed or the like) on the higher gear (smaller gear ratio) side is used, the vehicle is compared with the normal first speed start. As a result, the driving force (creep force) of the vehicle is reduced, which causes the driver to feel uncomfortable.

  The present invention has been made to solve the above-described problems, and its purpose is to give the driver a sense of incongruity even when the shift gear stage at the start cannot form a desired shift gear stage. There is no vehicle driving force control device.

  The vehicle driving force control device according to the first invention is equipped with an automatic transmission in which a plurality of forward gear stages having different gear ratios are formed by selectively engaging a plurality of friction engagement elements. Control the driving force of the vehicle. The driving force control device may not be able to form the first speed stage by the detecting means for detecting whether or not the first speed stage can be formed as the forward gear stage at the time of starting, and the detecting means. If detected, the shift control means for forming the forward gear stage on the higher gear side than the first speed stage, and the forward gear stage having a higher gear ratio than the first speed stage as the forward gear stage at the start of the vehicle. In the case of being formed, it includes driving force control means for controlling the driving force so that the driving force of the vehicle increases.

  According to the first aspect of the present invention, when the detecting means detects that the first speed normally used at the start of the vehicle cannot be formed due to a failure of the hydraulic circuit or the like, the speed change control means has a higher gear than the first speed. Side forward gear stage is formed. At this time, for example, the second gear starts on the high gear side, so that the driving force control means increases the driving force of the vehicle to produce the same driving force as when the first gear is formed and the vehicle starts. Generate in the vehicle. In this way, it can be avoided that the driver feels insufficient driving force due to the use of the forward gear on the high gear side. As a result, it is possible to provide a driving force control device for a vehicle that does not give the driver a sense of incongruity even when the speed change gear stage at the start cannot form a desired speed change gear stage.

  In the vehicle driving force control apparatus according to the second aspect of the invention, in addition to the configuration of the first aspect of the invention, the driving force control means adjusts the output rotational speed of the power source mounted on the vehicle to thereby increase the driving force. Means for controlling.

  According to the second invention, it is possible to control the driving force by increasing the output torque of the engine by increasing the rotational speed of the engine which is an example of the power source mounted on the vehicle.

  In addition to the configuration of the first or second aspect of the invention, the vehicle driving force control apparatus according to the third aspect of the present invention may be configured to perform a predetermined shift even if it is detected by the detecting means that the first speed stage can be formed. Until the shift determination to the first speed stage is made based on the conditions, a prohibiting means for prohibiting the shift to the first speed stage is further included.

  According to the third aspect of the present invention, when the first speed stage cannot be formed at the start of the vehicle, the forward gear stage on the higher gear side than the first speed stage is formed, and the driving force control is performed, the hydraulic circuit Even after recovering from the failure, the shift to the first speed is prohibited and, for example, the second speed start is continued. In this way, if the shift to the first speed gear stage is performed while the driving force control is being performed, the driving force suddenly increases excessively and the driver feels uncomfortable. For this reason, the shift to the first gear is prohibited by the prohibiting means to prevent a sudden change in the driving force.

  In the vehicle driving force control apparatus according to the fourth aspect of the invention, in addition to the configuration of the third aspect of the invention, the driving force control means is configured such that when the shifting to the first gear is prohibited by the prohibiting means, Means for controlling the driving force so that the driving force of the vehicle continuously increases is included.

  According to the fourth invention, the driving force control by the driving force control means is continued when the second speed is started by prohibiting the shift to the first speed by the prohibiting means, so that the driving force of the vehicle suddenly increases. You can keep it from changing.

  In the vehicle driving force control apparatus according to the fifth invention, in addition to the configuration of any one of the first to fourth inventions, the power source is an engine, and the automatic transmission includes a torque converter, a transmission mechanism, including. The driving force control means has the same output torque from the automatic transmission as when the first gear is formed even when the forward gear having a higher gear ratio than the first gear is formed. And means for increasing the engine torque to increase the torque input from the torque converter to the automatic transmission.

  According to the fifth aspect of the invention, the output torque from the engine is increased, and the torque input from the torque converter to the automatic transmission is increased. At this time, the output torque from the automatic transmission increases so as to be the same as when the first gear is formed even when the forward gear having a higher gear ratio than the first gear is formed. Let In this way, the same driving force can be generated even when the vehicle starts at the first gear and when the vehicle starts at the second gear on the higher gear side than the first gear.

  In the vehicle driving force control apparatus according to the sixth aspect of the invention, in addition to the configuration of the fifth aspect of the invention, the driving force control means includes means for increasing the engine speed.

  According to the sixth aspect of the invention, even if the engine speed is increased to increase the output torque from the engine and the vehicle starts with the second gear on the higher gear side than the first gear, the first speed It is possible to generate the same driving force as when starting from a stage.

  In the vehicle driving force control apparatus according to the seventh aspect of the invention, in addition to the structure of any one of the first to sixth aspects, the driving force control means is means for controlling the creep force of the vehicle to increase. including.

  According to the seventh aspect, since the creep force generated in the vehicle at the time of starting increases, for example, it is possible to prevent the vehicle from sliding down on an uphill road.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  With reference to FIG. 1, an automatic transmission system including a driving force control apparatus according to the present embodiment will be described. In the following description, it is assumed that the drive source of the vehicle is an engine. However, the drive source may be composed of an engine and a motor other than the engine, or only the motor (but has an automatic transmission). It may be.

This system includes an automatic transmission 10, a hydraulic control circuit 98, and an ECU (Electronic Control Unit) 90. The automatic transmission 10 is controlled by a hydraulic control circuit 98 so as to be in a desired power transmission state. Specifically, linear solenoid valves SL (1) to SL (6) provided in the hydraulic control circuit 98 regulate the hydraulic pressures of a plurality of friction engagement elements provided in the automatic transmission 10. The operations of the linear solenoid valves SL (1) to SL (6) are controlled based on an output command value output from the ECU 90. Moreover, ECU90 implement | achieves the driving force control apparatus which concerns on this Embodiment by running a program.

  As shown in FIG. 1, the accelerator position sensor 52 detects an operation amount Acc of the accelerator pedal 50. The accelerator position sensor 52 outputs a signal representing the accelerator operation amount Acc to the ECU 90. The driver operates the depression amount of the accelerator pedal 50 according to the driver's output request amount. The accelerator pedal 50 corresponds to an accelerator operation member. The accelerator operation amount Acc corresponds to the output request amount.

  The engine rotation speed sensor 58 outputs the detected rotation speed NE of the engine (not shown) to the ECU 90. The intake air amount sensor 60 outputs a signal representing the detected intake air amount Q to the ECU 90. The intake air temperature sensor 62 outputs a signal representing the detected intake intake air temperature T (A) to the ECU 90.

  A throttle position sensor 64 with an idle switch detects the fully closed state (idle state) and the opening degree θ (TH) of the electronic throttle valve of the engine. Throttle position sensor 64 outputs a signal representing detected throttle opening θ (TH) to ECU 90.

  The vehicle speed sensor 66 detects the vehicle speed V (corresponding to the rotational speed N (OUT) of the output shaft). Vehicle speed sensor 66 outputs a signal representing detected vehicle speed V to ECU 90. Cooling water temperature sensor 68 outputs a signal representing detected engine cooling water temperature T (W) to ECU 90.

  The brake switch 70 detects the presence or absence of operation of a foot brake, which is a service brake. The brake switch 70 outputs a signal indicating whether or not the foot brake is operated to the ECU 90.

  The lever position sensor 74 detects the lever position (operation position) P (SH) of the shift lever 72. The lever position sensor 74 outputs a signal representing the detected lever position P (SH) to the ECU 90.

  The turbine rotation speed sensor 76 detects a turbine rotation speed NT (= input shaft rotation speed N (IN)). Turbine rotational speed sensor 76 outputs a signal representing detected turbine rotational speed NT to ECU 90.

  The AT oil temperature sensor 78 detects an AT oil temperature T (OIL) that is the temperature of the hydraulic oil in the hydraulic control circuit 98. AT oil temperature sensor 78 outputs a signal representing detected AT oil temperature T (OIL) to ECU 90.

  When a shift range up command is input to upshift switch 80, upshift switch 80 outputs a signal representing command R (UP) to ECU 90. The downshift switch 82 outputs a signal representing the command R (DN) to the ECU 90 when the downshift switch 82 receives a shift range down command.

  As shown in FIG. 2, the automatic transmission 10 is suitably used for an FR vehicle mounted in the longitudinal direction of the vehicle (vertically placed), and has eight forward gear stages having different gear ratios (transmission ratios) as will be described later. And two reverse gear stages having different gear ratios are formed. The automatic transmission 10 includes a first transmission unit 14 mainly composed of a double pinion type first planetary gear unit 12, a single pinion type second planetary gear unit 16, and a double pinion type third planetary gear unit. A second transmission unit 20 mainly composed of 18 is provided on the coaxial line. The rotation of the input shaft 22 is shifted and output from the output shaft 24. The input shaft 22 corresponds to an input member, and in this embodiment, the input shaft 22 is a turbine shaft of a torque converter 32 that is rotationally driven by an engine 30 that is a driving power source. The output shaft 24 corresponds to an output member. In this embodiment, the output shaft 24 rotationally drives the left and right drive wheels via a propeller shaft and a differential gear device.

  The first planetary gear unit 12 constituting the first transmission unit 14 includes three rotating elements, that is, a sun gear S1, a carrier CA1, and a ring gear R1. The sun gear S1 is fixed to a transmission case (hereinafter simply referred to as a case) 26 so as not to rotate. The ring gear R1 functions as a deceleration output member when the carrier CA1 is integrally connected to the input shaft 22 and is driven to rotate, and decelerates and outputs the rotation of the input shaft 22.

  A part of the second planetary gear device 16 and the third planetary gear device 18 constituting the second transmission unit 20 are connected to each other, so that four rotating elements RM1 to RM4 are configured. Specifically, the first rotating element RM1 is configured by the sun gear S2 of the second planetary gear device 16. The second rotating element RM2 is configured by connecting a carrier CA2 of the second planetary gear unit 16 and a carrier CA3 of the third planetary gear unit 18 to each other. The third rotating element RM3 is configured by connecting the ring gear R2 of the second planetary gear device 16 and the ring gear R3 of the third planetary gear device 18 to each other. The fourth rotation element RM4 is configured by the sun gear S3 of the third planetary gear unit 18.

  In the second planetary gear device 16 and the third planetary gear device 18, the carrier CA2 and the carrier CA3 are configured by a common member. Further, in the second planetary gear device 16 and the third planetary gear device 18, the ring gear R2 and the ring gear R3 are constituted by a common member. The pinion gear of the second planetary gear device 16 also serves as the second pinion gear of the third planetary gear device 18.

  The first rotation element RM1 (sun gear S2) is selectively connected to the case 26 by the first brake B1 and stopped. The second rotation element RM2 (carriers CA2, CA3) is selectively coupled to the case 26 by the second brake B2 and stopped. The fourth rotation element RM4 (sun gear S3) is selectively connected to the ring gear R1 of the first planetary gear device 12 which is a reduction output member via the first clutch C1. The second rotating element RM2 (carriers CA2, CA3) is selectively coupled to the input shaft 22 via the second clutch C2. The first rotation element RM1 (sun gear S2) is selectively connected to a ring gear R1 that is a reduction output member via a third clutch C3. Further, the first rotating element RM1 is selectively coupled to the carrier CA1 of the first planetary gear device 12, that is, the input shaft 22 via the fourth clutch C4. The third rotation element RM3 (ring gears R2, R3) is integrally connected to the output shaft 24 and rotates. A direction between the second rotating element RM2 (carriers CA2 and CA3) and the case 26 that prevents the reverse rotation while allowing the second rotating element RM2 to rotate forward (the same rotational direction as the input shaft 22). A clutch F1 is provided in parallel with the second brake B2.

  FIG. 3 is a collinear diagram that can represent the rotational speeds of the rotating elements of the first transmission unit 14 and the second transmission unit 20 with straight lines. In FIG. 3, the lower horizontal line indicates the rotation speed “0”. The upper horizontal line indicates that the rotation speed is “1.0”, that is, the same rotation speed as that of the input shaft 22. Each vertical line of the first transmission unit 14 represents the sun gear S1, the ring gear R1, and the carrier CA1 in order from the left side. The distance between them is determined according to the gear ratio (= the number of teeth of the sun gear / the number of teeth of the ring gear) ρ1 of the first planetary gear device 12. The four vertical lines of the second transmission unit 20 indicate the first rotation element RM1 (sun gear S2), the second rotation element RM2 (carriers CA2 and CA3), and the third rotation element RM3 (ring gear) in order from the left end to the right end. R2, R3), the fourth rotating element RM4 (sun gear S3). These intervals are determined according to the gear ratio ρ2 of the second planetary gear device 16 and the gear ratio ρ3 of the third planetary gear device 18.

  As is apparent from the alignment chart shown in FIG. 3, when the first clutch C1 and the second brake B2 are engaged, the fourth rotating element RM4 is rotated at a reduced speed integrally with the ring gear R1 that is a reduction output member. . Further, the rotation of the second rotation element RM2 is stopped, and the third rotation element RM3 connected to the output shaft 24 is rotated at the rotation speed indicated by “1st”. That is, the first gear stage “1st” having the largest speed ratio (= the rotational speed N (IN) of the input shaft 22 / the rotational speed N (OUT) of the output shaft 24) is established.

  When the first clutch C1 and the first brake B1 are engaged, the fourth rotating element RM4 is rotated at a reduced speed integrally with the ring gear R1. Further, the rotation of the first rotation element RM1 is stopped, and the third rotation element RM3 is rotated at the rotation speed indicated by “2nd”. That is, the second shift stage “2nd” having a smaller speed ratio than the first shift stage “1st” is established.

  When the first clutch C1 and the third clutch C3 are engaged, the second transmission unit 20 is rotated at a reduced speed integrally with the ring gear R1, and the third rotational element RM3 is rotated at a rotational speed (ring gear) indicated by “3rd”. The same rotation speed as R1). That is, the third shift stage “3rd” having a smaller speed ratio than the second shift stage “2nd” is established.

  When the first clutch C1 and the fourth clutch C4 are engaged, the fourth rotating element RM4 is rotated at a reduced speed integrally with the ring gear R1. Further, the first rotation element RM1 is rotated integrally with the input shaft 22, and the third rotation element RM3 is rotated at a rotation speed indicated by “4th”. That is, the fourth shift stage “4th” having a smaller speed ratio than the third shift stage “3rd” is established.

  When the first clutch C1 and the second clutch C2 are engaged, the fourth rotating element RM4 is rotated at a reduced speed integrally with the ring gear R1. Further, the second rotation element RM2 is rotated integrally with the input shaft 22, and the third rotation element RM3 is rotated at a rotation speed indicated by “5th”. That is, the fifth shift stage “5th” having a smaller speed ratio than the fourth shift stage “4th” is established.

  When the second clutch C2 and the fourth clutch C4 are engaged, the second transmission unit 20 is rotated integrally with the input shaft 22, and the third rotating element RM3 is rotated at the rotational speed indicated by “6th” (input shaft). 22). That is, the sixth shift stage “6th” having a smaller speed ratio than the fifth shift stage “5th” is established. The gear ratio of the sixth gear stage “6th” is 1.

  When the second clutch C2 and the third clutch C3 are engaged, the second rotating element RM2 is rotated integrally with the input shaft 22. Further, the first rotation element RM1 is rotated at a reduced speed integrally with the ring gear R1, and the third rotation element RM3 is rotated at a rotation speed indicated by “7th”. That is, the seventh shift stage “7th” having a smaller gear ratio than the sixth shift stage “6th” is established.

  When the second clutch C2 and the first brake B1 are engaged, the second rotation element RM2 is rotated integrally with the input shaft 22. Further, the first rotation element RM1 is stopped from rotating, and the third rotation element RM3 is rotated at the rotation speed indicated by “8th”. That is, the eighth shift stage “8th” having a smaller speed ratio than the seventh shift stage “7th” is established.

  On the other hand, when the second brake B2 and the third clutch C3 are engaged, the rotation of the second rotation element RM2 is stopped. Further, the first rotating element RM1 is rotated at a reduced speed integrally with the ring gear R1, and the third rotating element RM3 is rotated in reverse at the rotation speed indicated by “Rev1”. That is, the first reverse shift speed “Rev1” is established.

  When the second brake B2 and the fourth clutch C4 are engaged, the second rotation element RM2 is stopped from rotating. Further, the first rotating element RM1 is rotated integrally with the input shaft 22, and the third rotating element RM3 is rotated reversely at a rotation speed indicated by “Rev2”. That is, the second reverse shift speed “Rev2” is established.

  The operation table shown in FIG. 4 summarizes the relationship between the above-described gear stages and the operation states of the clutches C1 to C4 and the brakes B1 and B2. In the operation table, “◯” represents engagement, and “(◯)” represents engagement only during engine braking. Since the one-way clutch F1 is provided in parallel with the second brake B2 that establishes the first gear “1st”, it is not always necessary to engage the second brake B2 at the time of start (acceleration). The gear ratio of each gear stage is appropriately determined by the gear ratios ρ1, ρ2, and ρ3 of the first planetary gear device 12, the second planetary gear device 16, and the third planetary gear device 18.

  The clutches C1 to C4 and the brakes B1 and B2 (hereinafter simply referred to as the clutch C and the brake B unless otherwise distinguished) are hydraulically controlled by a hydraulic actuator such as a multi-plate clutch or brake. This is a friction engagement element. The clutch C and the brake B are switched between engaged and disengaged states by excitation, non-excitation, and current control of the linear solenoid valves SL1 to SL6 of the hydraulic control circuit 98. Further, in the clutch C and the brake B, the transient hydraulic pressure at the time of engagement and release is controlled.

  The shift lever 72 and the lever position (operation position) will be described with reference to FIG. As shown in FIG. 5, the shift lever 72 has a parking position (P position), a reverse travel position (R position), a neutral position (N position), a forward travel position (D position), and a manual (manual) as lever positions. It has a shift position (M position). The M position includes “+ position” linked to the upshift switch 80 and “−position” linked to the downshift switch 82.

  In the M position, the shift range can be selected by operating the shift lever 72 to “+ position” or “−position”, but the gear stage (gear ratio) may be selected. In this embodiment, by operating the shift lever 72 once at the “+” side or the “−” side at the M position, 8 ranges (8th, 7th, 6th, 5th, 4th, 3rd, Speed, 2nd speed, 1st speed), 7 range (uses other than 8th speed), 6 range (uses other than 8th and 7th speed), 5 range (5th speed, 4th speed, 3rd speed, 2nd speed, 1st speed) Speed), 4 ranges (use 4th speed, 3rd speed, 2nd speed, 1st speed), 3 ranges (use 3rd speed, 2nd speed, 1st speed), 2 ranges (use 2nd speed, 1st speed), The L range (using 1st gear) switches in order. As an example of selecting the gear stage, by operating the shift lever 72 once at the “+” side or the “−” side at the M position, the 8th speed (8th), 7th speed (7th), 6th speed ( 6th), 5th speed (5th), 4th speed (4th), 3rd speed (3rd), 2nd speed (2nd), 1st speed (1st) are switched in order. Note that the present invention can be applied to any form of such an M position, and can be applied regardless of the presence or absence of the M position.

  With reference to FIG. 6, the control structure of the program executed by ECU 90 that is the driving force control apparatus according to the present embodiment will be described. Here, in the present embodiment, when starting at the first speed (1st) in the forward running position (D position or M position), 1st shown in FIG. 4 cannot be formed and 2nd is formed. It should be noted that the program represented by this flowchart is repeatedly performed at predetermined time intervals when engine 30 is in operation.

  In step (hereinafter step is abbreviated as S) 100, ECU 90 determines whether or not a 1st gear start request has been made. In the D position, it is usually 1st start. Also, in the M position, it is usually 1st start. If the 1st gear start request is made (YES in S100), the process proceeds to S200. Otherwise (NO in S100), this process ends.

  In S200, ECU 90 determines whether or not a failure determination for the first gear stage has been detected. There are various methods for determining the failure, and the present invention may be any method. If the first gear stage failure determination has been detected (YES in S200), the process proceeds to S400. If not (NO in S200), the process proceeds to S300.

  In S300, ECU 90 starts the vehicle at the first gear.

  In S400, ECU 90 executes a torque increase process. At this time, the ECU 90 considers the torque change (amplification) in the torque converter 32 in order to increase the output torque of the torque converter 32 so that the driving force output from the automatic transmission 10 is the same as that in the first gear. Thus, the generated torque in the engine 30 is increased. In engine 30, the engine speed is increased from the engine speed-torque characteristic curve to the engine speed corresponding to the torque to be increased.

  In S500, ECU 90 starts the vehicle at the 2nd gear stage on the higher gear side than the first gear stage.

  In S600, ECU 90 determines whether or not the failure determination release of the first gear is detected. If first-gear failure determination release is detected (YES in S600), the process proceeds to S700. If not (NO in S600), the process returns to S600.

  In S700, ECU 90 determines whether or not the shift to another gear stage has been completed. This is because the vehicle speed increases after the vehicle starts, for example, a predetermined shift line map (a map of the vehicle speed and the required output amount (accelerator opening) is defined by an upshift shift line and a downshift shift line. When the upshift shift line is exceeded based on the map), a shift command to another gear stage is output, and the desired friction engagement element is released and engaged to form another gear stage. . When the shift to another gear stage is completed (YES in S700), the process proceeds to S800. If not (NO in S700), the process returns to S700.

  In S800, ECU 90 cancels the torque increase process. In other words, even if the 1st gear stage failure determination release is detected at the time of 2nd start, which is the high gear side transmission gear stage other than 1st, the torque increasing process is continuously performed to prevent a sudden change in the driving force.

  The operation of the vehicle controlled by ECU 90 that is the driving force control apparatus according to the present embodiment in the above-described structure and flowchart will be described.

  When starting from a state where the vehicle is stopped, if the D position is selected as the shift position or the 1st position of the M position is selected, a start at the 1st gear position is required. (YES at S100). However, if a failure determination of the first gear stage is detected due to an abnormality in hydraulic control circuit 98 (YES in S200), the engine 30 is increased in speed and engine torque increase processing is performed (S400). At this time, the driving force (torque) output from the automatic transmission 10 when the second gear stage is formed is the driving force (torque) output from the automatic transmission 10 when the first gear stage is formed. The engine torque input to the torque converter 32 is controlled so as to be the same.

  In this way, the torque of the engine 30 is increased, and the vehicle is started at the 2nd gear stage that is on the higher gear side than the first gear stage. The state at this time is shown in FIG. As shown in FIG. 7, when the vehicle cannot start at the 1st gear stage and the vehicle starts at the 2nd gear stage, the engine 30 is controlled to increase the driving force of the vehicle as indicated by an arrow. This reduces the uncomfortable feeling that the driving force with respect to the accelerator opening felt by the driver when starting the vehicle is too small when the first gear is not realized when the vehicle starts and the 2nd gear on the high gear side is realized. be able to. In particular, on an uphill road, it is possible to reduce a sense of incongruity that the creep force when starting the vehicle is too small.

  When the vehicle is starting in such a state, even if the failure determination release of the first gear stage is detected (YES in S600), the shift to the other gear stage is completed (YES in S700). ) Continue the torque increase process. If this is done, even if the failure determination release of the 1st gear stage is detected, if the gear is immediately shifted to the 1st gear stage, the gear shifts to the low gear side and the driving force suddenly becomes too large. Since the torque increase process is continuously performed until the shift to another gear stage is completed, it is possible to prevent the driver from feeling uncomfortable due to such a sudden change in driving force.

  As described above, when the first gear, which is the forward travel gear normally used when the vehicle starts, cannot be formed due to a failure of the hydraulic control circuit, the vehicle starts on the high gear side (2nd gear). Done. In such a case, when it is determined that the gear ratio of the forward travel stage that is actually set is high, the driving force of the engine is increased. As a result, a driving force (creep force) closer to the driving force including the creep force intended by the driver (corresponding to the first gear stage of the forward travel stage) can be generated, thereby reducing the driver's uncomfortable feeling. it can. As a result, it is possible to provide a driving force control device for a vehicle that does not give the driver a sense of incongruity even when the speed change gear stage at the time of starting cannot form a desired speed change gear stage.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a control block diagram provided in the vehicle in order to control the automatic transmission in the embodiment of the present invention. 1 is a skeleton diagram of an automatic transmission according to an embodiment of the present invention. It is a collinear diagram showing the rotational speed of each rotation element of an automatic transmission. It is an operation | movement table | surface which shows the engagement element which establishes the several gear stage in the automatic transmission of embodiment of this invention. It is a figure which shows the shift lever of the automatic transmission of embodiment of this invention. It is a flowchart which shows the control structure of the program performed by ECU which concerns on embodiment of this invention. It is a figure which shows the relationship between the throttle opening and drive force in embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Automatic transmission, 12 1st planetary gear apparatus, 14 1st transmission part, 16 2nd planetary gear apparatus, 18 3rd planetary gear apparatus, 20 2nd transmission part, 22 input shaft, 24 output shaft, 26 transmission case, 30 engine, 32 torque converter, 50 accelerator pedal, 52 accelerator position sensor, 58 engine rotation speed sensor, 60 intake air amount sensor, 62 intake air temperature sensor, 64 throttle position sensor, 66 vehicle speed sensor, 68 cooling water temperature sensor, 70 brake Switch, 72 shift lever, 74 lever position sensor, 76 turbine rotational speed sensor, 78 AT oil temperature sensor, 80 upshift switch, 82 downshift switch, 90 ECU, 98 hydraulic control circuit.

Claims (7)

A driving force control device for a vehicle equipped with an automatic transmission in which a plurality of forward gears having different gear ratios are formed by selectively engaging a plurality of friction engagement elements,
Detecting means for detecting whether or not the first gear can be formed as the forward gear at the time of start;
A shift control means for forming a forward gear on the higher gear side than the first speed when the detecting means detects that the first speed cannot be formed;
Driving force control means for controlling the driving force so as to increase the driving force of the vehicle when a forward gear step having a higher gear ratio than the first gear is formed as the forward gear at the time of starting. A vehicle driving force control device including:   The vehicle driving force control device according to claim 1, wherein the driving force control means includes means for controlling the driving force by adjusting an output rotational speed of a power source mounted on the vehicle.   Even if it is detected by the detecting means that the first speed stage can be formed, the first speed stage is changed until the shift determination to the first speed stage is made based on a predetermined speed change condition. The vehicle driving force control device according to claim 1, further comprising prohibiting means for prohibiting shifting of the vehicle.   The driving force control means includes means for controlling the driving force so that the driving force of the vehicle continuously increases when shifting to the first gear is prohibited by the prohibiting means. The vehicle driving force control device according to claim 3, further comprising: The power source is an engine,
The automatic transmission includes a torque converter and a transmission mechanism,
The driving force control means is configured such that when the first speed stage is formed even if the output torque from the automatic transmission is a forward gear stage having a higher gear ratio than the first speed stage. 5. The vehicle according to claim 1, further comprising means for increasing the torque of the engine so as to increase the torque input from the torque converter to the automatic transmission. Driving force control device.   The vehicle driving force control device according to claim 5, wherein the driving force control means includes means for increasing the number of revolutions of the engine.   The vehicle driving force control device according to claim 1, wherein the driving force control means includes means for controlling the creep force of the vehicle to increase.

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