JP2006132674A - Start friction element control device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a start clutch control device for a vehicle capable of generating creep torque in accordance with probability of starting the vehicle during stopping the vehicle. <P>SOLUTION: In a transmission controller 40 for controlling a forward clutch 20, fastening torque of the forward clutch 20 is released during stopping the vehicle, and high probability of starting the vehicle is estimated when brake stroke is reduced during stopping the vehicle, so that the fastening torque of the forward clutch 20 is increased to generate the creep torque. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a starting friction element control device for a vehicle capable of generating a creep torque by operating a starting friction element provided in a power transmission path from an engine to a drive wheel.

As this type of technology, when the brake is operated and the vehicle is stopped, the clutch torque is weakened to protect the clutch and reduce fuel consumption. In this case, in order to avoid deterioration of the start response when the vehicle restarts within a short time after the vehicle stops, creep torque is generated within a predetermined time after the vehicle stops, and further when the predetermined time is exceeded. There has been proposed one that generates a creep torque by weakening a clutch torque (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 2001-116067

  However, in the above prior art, the creep torque generation time after the vehicle stops is set to a predetermined time regardless of whether the vehicle actually starts or does not start. Therefore, when the vehicle does not actually start, the generation of unnecessary creep torque causes deterioration of fuel consumption and clutch strength, and when the vehicle actually starts, the vehicle stop time has passed a predetermined time. In this case, there is a drawback that sufficient creep torque is not generated and the response of the restart is deteriorated.

  The present invention has been made paying attention to the above problems, and an object of the present invention is to provide a vehicle start clutch control device capable of generating creep torque according to the possibility of vehicle start while the vehicle is stopped. There is to do.

  In order to achieve the above object, in the present invention, a starting friction element control for a vehicle that controls a starting friction element that is mounted on a vehicle and disposed between an engine and a transmission mechanism to generate a creep torque in a slip state. In the apparatus, a creep torque reducing means for reducing the creep torque while the vehicle is stopped, a start possibility estimating means for estimating that the vehicle is likely to start within a short time while the vehicle is stopped, and the start possibility estimating means When the vehicle is estimated to be highly likely to start, creep torque increasing means for increasing the creep torque while the vehicle is stopped is provided.

  In the present invention, the starting friction element control device for controlling the starting friction element estimates the possibility of starting the vehicle within a short time, and increases the creep torque when it is estimated that the possibility of starting the vehicle is high.

  Therefore, when the possibility of starting the vehicle within a short period of time is low, the generation of unnecessary creep torque can be reduced, and fuel efficiency and clutch strength can be improved. Further, when the possibility of starting the vehicle within a short time is high, a creep torque can be obtained at the time of restart, and a good start response can be ensured.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS The best mode for carrying out a vehicle starting friction element control apparatus according to the present invention will be described below with reference to the drawings.

  First, the configuration of the vehicle starting friction element control device of this embodiment will be described.

  FIG. 1 is an overall system diagram showing the configuration of a drive system and a control system of a vehicle equipped with a belt-type continuously variable transmission equipped with a starting friction element control device of the present embodiment.

  A vehicle equipped with a belt-type continuously variable transmission includes an engine 1, a torsional damper 3 that reduces vibration of the engine 1, a forward / reverse switching mechanism 6 having a starting clutch, and a belt-type continuously variable transmission that continuously shifts between input and output. The transmission 19 includes an output gear 12 and a drive gear 13 that reduce the output, and left and right drive wheels 17 and 18 that are driven through a differential gear 14 and left and right drive shafts 15 and 16.

  In the engine 1, the engine output shaft 2 is connected to the input portion of the torsional damper 3.

  The torsional damper 3 is configured such that an input part connected to the engine output shaft 2 and an output part connected to the transmission input shaft 5 are connected to each other via a torsion spring so as to be relatively rotatable. . In addition, the flywheel 4 which rotates integrally with this is fixed to the output part.

  The forward / reverse switching mechanism 6 includes a simple planetary gear 22 capable of switching the rotation direction and gear ratio, a forward clutch 20 that is fastened and constitutes a starting friction element of the present invention, and a forward friction that is fastened backward and is also of the present invention. And a reverse brake 21 as an element.

  The simple planetary gear 22 rotatably supports a sun gear 22s that rotates concentrically with the primary pulley shaft 7, a plurality of pinions 22p that mesh with the sun gear 22s, a ring gear 22r that meshes with the pinion 22p, and the pinion. And a carrier 22c. The sun gear 22s is connected to the driven side portion of the forward clutch 20 and the primary pulley shaft 7, the carrier 22c is connected to the fixed side portion of the reverse brake 21, and the ring gear 22r is connected to the drive side portion of the forward clutch 20.

  The forward clutch 20 is configured such that a plurality of plates are interposed between a drive side portion connected to the transmission input shaft 5 and a driven side portion connected to the primary pulley shaft 7. A fastening state in which power can be transmitted between the input and output by pressing the plate by applying clutch oil pressure to a piston (not shown), and a release state in which power transmission at the output side is cut off by discharging the clutch oil pressure acting on the piston And can be switched to.

  The reverse brake 21 is configured such that a plurality of plates are interposed between an inner fixed portion of the transmission case 23 and a fixed side portion connected to the carrier 22c. A fastening state in which a plate is pressed by applying brake hydraulic pressure to a piston (not shown) and the integral carrier 22c is fixed to the fixed side portion in a non-rotatable manner; The carrier 22c can be switched to a released state in which the carrier 22c can rotate.

  The forward clutch 20 and the reverse brake 21 correspond to the starting friction element of the present invention.

  The belt type continuously variable transmission 19 continuously changes the speed ratio between the input and output shafts. The belt type continuously variable transmission 19 includes a primary pulley 8 connected to the primary pulley shaft 7, a secondary pulley 10 connected to the secondary pulley shaft 11, and a CVT belt that is stretched between the primary pulley 8 and the secondary pulley 10. 9.

  The primary pulley 8 and the secondary pulley 10 have fixed sheaves 8a and 10a, movable sheaves 8b and 10b that approach and leave the fixed sheaves 8a and 10a, respectively. A primary pulley oil chamber 33 is provided on the back surface of the movable sheave 8 b of the primary pulley 8.

  The hydraulic pressure supplied to the primary pulley oil chamber 33 is controlled by the hydraulic pressure control unit 32 so that the movable sheave 8b is moved relative to the fixed sheave 8a so as to approach and separate from the fixed sheave 8a. An oil tank 30 is provided, and pressure oil obtained by sucking oil from the oil tank 30 by the oil pump 31 is supplied to the hydraulic control unit 32.

  Next, the control system of the vehicle equipped with the belt type continuously variable transmission according to the first embodiment will be described with reference to FIG.

  The control system includes a transmission controller 40 that controls the forward / reverse switching mechanism 6 and the hydraulic control unit 32 of the belt-type continuously variable transmission 19, and sensors connected to the transmission controller 40.

  Connected to the transmission controller 40 are a brake stroke sensor 41 for detecting the amount of brake stroke, an inter-vehicle distance detection device 42 for detecting the inter-vehicle distance between the host vehicle and the preceding vehicle, and a vehicle speed sensor 43 for detecting the vehicle speed. . From these, brake stroke amount information, inter-vehicle distance information, and vehicle speed information are input. The brake stroke sensor 41 corresponds to the brake return detection means of the present invention.

  The transmission controller 40 is connected to a forward clutch solenoid 44 that controls the hydraulic pressure supplied to the forward clutch 20 and a reverse brake solenoid 45 that controls the hydraulic pressure supplied to the reverse brake 21.

  The transmission controller 40 controls the forward clutch solenoid 44 and the reverse brake solenoid 45 so as to switch the forward clutch 20 and the reverse brake 21 to the fully engaged state, the slip state, and the released state, respectively, based on the information from the sensors. The transmission controller 40 further controls the hydraulic pressure supplied to the primary pulley oil chamber 33 by a solenoid valve (not shown) provided in the hydraulic pressure control unit 32.

  An output gear 12 is fixed to the end of the secondary pulley shaft 11 on the secondary pulley 10 side of the belt type continuously variable transmission 19, and meshed with a drive gear 13 having a larger diameter than the output gear 12.

  Two pinions of the differential gear 14 are fixed to the drive gear 13, and side gears are engaged with these pinions from the left and right, respectively. Drive shafts 15 and 16 are connected to the side gears to drive the left and right drive wheels 17 and 18.

  Next, the operation will be described.

  When the engine 1 is operating, the oil pump 31 is driven to supply pressure oil to the hydraulic control unit 32.

  When the vehicle is stopped and the select lever (not shown) is selected to a non-traveling position such as a P (park) position or an N (neutral) position, the generation of creep torque is stopped. Further, when the vehicle is stopped and the select lever is selected to a travel position such as a D (drive) position or an R (reverse) position, the generation and stop of creep torque are controlled according to conditions.

[Vehicle stop when non-traveling position is selected]
When the select lever (not shown) is in the non-travel position, the transmission controller 40 performs control to keep the release clutch 20 and the reverse brake 21 in a released state without supplying pressure oil to the forward clutch 20 and the reverse brake 21. Therefore, the driving force of the transmission input shaft 5 is not transmitted to the primary pulley shaft 7 and the belt type continuously variable transmission 19 is not rotated. As a result, the driving force does not act on the driving wheels 17 and 18.

[Vehicle stop when driving position is selected]
On the other hand, when the vehicle is stopped and the select lever is at the travel position, it is desirable that creep torque is generated in order to ensure a good response when the vehicle restarts. However, when creep torque is generated, oil is supplied to the forward clutch 20 or the reverse brake 21, and the forward clutch 20 or the reverse brake 21 is brought into a slip state at a hydraulic pressure lower than the complete engagement pressure. There is a drawback.

  Therefore, in this embodiment, when the vehicle is stopped and the select lever is in the traveling position, the transmission controller 40 does not supply pressure oil to the forward clutch 20 and the reverse brake 21, but releases them to perform creep torque. Stop the occurrence of.

  However, when it is estimated that the vehicle is likely to start within a short time, the transmission controller 40 applies pressure to the forward clutch 20 and the reverse brake 21 in order to ensure a good response when the vehicle restarts. Supply oil. Then, the forward clutch 20 or the reverse brake 21 is slipped at a hydraulic pressure lower than the complete engagement pressure to generate a creep torque.

  In the present embodiment, the possibility of starting the vehicle within a short time is estimated based on the following three conditions.

  First, when the vehicle is stopped with the select lever at the travel position, the driver often starts the vehicle again. Therefore, it can be estimated that the possibility of vehicle start is high when a certain amount of time has passed since the vehicle stopped.

  Next, when the vehicle ahead starts, the vehicle is often started. For example, when the host vehicle behind the preceding vehicle stops like waiting for a signal, it can be estimated that if the preceding vehicle starts, the host vehicle is likely to start.

  Finally, since the brake is released when the driver starts the vehicle, it can be estimated that the possibility of starting the vehicle is high when a brake return that reduces the brake stroke amount is detected.

  However, even if creep torque is generated on the assumption that the vehicle is likely to start due to the above three conditions, the vehicle may not actually start. For example, the driver may continue to stop even if the vehicle ahead starts. If creep torque is continuously generated in a state where the vehicle continues to stop, the forward clutch 20 or the reverse brake 21 continues to slip, so that the clutch durability, fuel consumption, and the like deteriorate.

  Therefore, in this embodiment, even if a certain amount of time has elapsed after the generation of the creep torque, the generation of the creep torque is stopped if the vehicle has not started.

  Hereinafter, control of the forward clutch 20 and the reverse brake 21 by the transmission controller 40 when the vehicle is stopped and the select lever is in the travel position will be described.

  FIG. 2 is a flowchart showing a flow of control of the forward clutch 20 and the reverse brake 21 by the transmission controller 40 when the select lever is in the traveling position.

  In step S1, it is determined whether or not the vehicle is stopped based on the vehicle speed information from the vehicle speed sensor 43. If the vehicle is stopped, the process proceeds to step S2. If the vehicle is not stopped, step S1 is performed. The determination of S1 is repeated.

  In step S2, the supply of pressure oil to the forward clutch 20 and the reverse brake 21 is stopped, and these are released to stop the generation of creep torque. The control in step S2 corresponds to the creep torque reducing means of the present invention.

  In step S3, it is determined whether time t1 has elapsed since the vehicle stopped. When the time t1 elapses from the stop of the vehicle, it is estimated that the vehicle is likely to start, and the process proceeds to step S6. When the time t1 has not elapsed since the stop of the vehicle, the process proceeds to step S4.

  This time t1 is calculated by experiment or calculation of the time when the vehicle is likely to start due to the time trend from the vehicle stop to the vehicle start. The time t1 corresponds to the first predetermined time of the present invention.

  In step S4, it is determined by the inter-vehicle distance detection device 42 whether the inter-vehicle distance between the host vehicle and the preceding vehicle has changed. If the distance to the preceding vehicle has changed, it is estimated that the vehicle is likely to start, and the process proceeds to step S6. If the inter-vehicle distance from the preceding vehicle has not changed, the process proceeds to step S5.

  In step S <b> 5, it is determined whether the brake return that the brake stroke amount decreases is detected by the brake stroke sensor 41. If the brake return is detected, it is estimated that the vehicle is likely to start, and the process proceeds to step S6. If the brake return is not detected, the process returns to step S3. The brake return may be detected when the brake fluid pressure is reduced by a brake fluid pressure sensor (not shown) or may be detected when the brake pedal force is reduced by a brake pedal force sensor (not shown). good.

  The control from step S3 to step S5 corresponds to the start possibility estimation means of the present invention.

  In step S6, pressure oil is supplied to the starting friction element corresponding to the select position of the select lever of the forward clutch 20 or the reverse brake 21. The hydraulic pressure is lower than the complete fastening pressure of the starting friction element, and the starting friction element slips to generate creep torque in the vehicle. The control in step S6 corresponds to the creep torque increasing means of the present invention.

  In step S7, the start of the vehicle is determined. If the vehicle has not started, the process proceeds to step S8. If the vehicle has started, the process proceeds to step S10, and clutch torque control at the time of vehicle start described later is performed.

  In step S8, it is determined whether time t2 has elapsed since the occurrence of creep torque. If creep torque is generated and the vehicle does not start even after time t2, the process proceeds to step S9 and the generation of creep torque is stopped. On the other hand, if creep torque is generated and time t2 or less, the process returns to step S7.

  This time t2 is obtained by experiment or calculation in consideration of the durability of the clutch. This time t2 corresponds to the second predetermined value of the present invention.

  FIG. 3 is a time chart showing the relationship between the brake operation, the vehicle speed, and the clutch torque in comparison with that according to the prior art and that according to the present embodiment, which will be described below. FIG. 3A shows a time chart of creep torque control according to the prior art. FIG. 3B is a time chart of the creep torque control according to the present embodiment. The control is performed when the vehicle starts before the time t2 from the generation of the creep torque and when the vehicle stops after the time t2 after the generation of the creep torque. The time chart is shown. In the figure, the vehicle speed and the clutch torque are not actual magnitudes, but schematically show their changing tendency.

  In the conventional creep torque control, when the brake operation is performed, the vehicle speed and the clutch torque decrease. When the vehicle speed is zero and the vehicle is stopped, creep torque control is started regardless of the possibility of vehicle start if the select lever remains selected at the travel position.

  Pressure oil that is slightly reduced from the fully engaged pressure is supplied to the starting clutch so that creep torque is generated from the time the vehicle stops until time T1. When the time T1 is exceeded, the pressure oil supplied to the starting clutch is automatically further reduced so that weak creep torque continues to be generated. As a result, even when there is no start request from the driver, creep torque continues to be generated, causing not only fuel consumption deterioration and clutch durability deterioration, but also a weak start if the time T1 has passed even if it tries to restart with creep. Only creep torque can be obtained.

  On the other hand, in the creep torque control of this embodiment, when the brake operation is performed and the vehicle speed and the clutch torque are reduced, the vehicle speed becomes zero and the vehicle stops, the select lever remains selected at the travel position. Even so, the creep torque control is temporarily stopped.

  If it is estimated at time t that the vehicle has stopped and time t1 has elapsed, the distance between the host vehicle and the preceding vehicle has changed, or the brake return has been detected, the vehicle is likely to start. Generate creep torque.

  When the vehicle starts at time t3 before the time t2 elapses from the generation of the creep torque, control at the time of vehicle start described later for increasing the creep torque is performed. If the vehicle is still stopped when time t2 has elapsed since the generation of the creep torque, the generation of the clutch torque is stopped.

  Thus, when the vehicle is stopped, the clutch torque is generated only when the possibility of starting the vehicle is high, and when the vehicle is not started even if the clutch torque is generated, the generation of the clutch torque is stopped. Therefore, it is possible to improve the durability and fuel consumption of the clutch while ensuring the start response of the vehicle.

[When the vehicle starts]
When the engine 1 is in an operating state and the select lever is moved from the non-travel position to the forward travel position, or while the creep lever is stopped even if the select lever is in the forward travel position while the vehicle is stopped, When starting, the following control is performed.

  The transmission controller 40 switches a valve (not shown) in the hydraulic control unit 32 and starts to supply new pressure oil to the forward clutch 20 from which oil has already been discharged. At this time, the magnitude of the hydraulic pressure supplied to the forward clutch 20 is initially lower than the fully engaged pressure until a predetermined time elapses, and the forward clutch 20 is brought into a slip state. Thereby, the fastening shock which arises when the forward clutch 20 is rapidly fastened at a high pressure can be avoided.

  On the other hand, when the engine 1 is in an operating state and stopped while the select lever is in the forward travel position, and when creep torque is being generated, the forward clutch 20 is supplied with a reduced hydraulic pressure regardless of when it is stopped. Already slipped. Therefore, the vehicle can immediately travel forward with creep, and the response of restarting is improved accordingly.

  The power transmitted to the primary pulley shaft 7 through the forward clutch 20 in this way is further transmitted to the belt type continuously variable transmission 19 in any case. Here, the motor is decelerated and output to the secondary pulley shaft 11, and then is transmitted to the drive wheels 17 and 18 through the output gear 12, drive gear 13, differential gear 14, and drive shafts 15 and 16 in this order. As a result, the vehicle starts and moves forward.

  After a set time has elapsed since the start of the slip control, the transmission controller 40 gradually increases the hydraulic pressure supplied to the forward clutch 20. Then, the hydraulic pressure supplied to the forward clutch 20 is controlled so as to be in a completely engaged state where the clutch engagement torque is not larger than the engine torque, that is, the engine engagement torque or more.

  In this forward travel position, no pressure oil is supplied to the reverse brake 21, and the reverse brake 21 is in a released state.

  The same control as when the forward travel position is selected is performed when the reverse travel position of the select lever is selected. When the select lever is moved from the non-travel position to the reverse travel position, or even if the select lever is in the reverse travel position while the vehicle is stopped, the oil is already Is supplied to the reverse brake 21 from which the pressure has been discharged.

On the other hand, when the vehicle is stopped while the select lever is in the reverse travel position and the creep torque is being generated, the pressure oil of a size that can be creeped is already supplied to and held by the reverse brake 21. Therefore, the vehicle can immediately travel backward by creep, and the response of restarting is improved accordingly. In these cases, oil is discharged from the forward clutch 20.
[When the vehicle is running after starting]
As described above, when the set time elapses after starting at the forward travel position or the reverse travel position, the transmission controller 40 controls the valve of the hydraulic control unit 32 to increase the hydraulic pressure supplied to the forward clutch 20 or the reverse brake 21. To go. Finally, the engagement torque at the forward clutch 20 becomes equal to or higher than the engine torque so that a complete engagement state without slipping is achieved.

  In this case, during forward travel, the sun gear 22s of the forward / reverse switching mechanism 6 has the same rotational speed as that of the ring gear 22r, so that they rotate together with the carrier 22c. Therefore, the primary pulley shaft 7 rotates in the same direction and at the same rotation speed as the transmission input shaft 5, and the power of the engine 1 is input to the belt type continuously variable transmission 19 as it is.

  On the other hand, since the carrier 22c cannot be rotated by the reverse brake 21 during reverse travel, the sun gear 22s reverses at an increased speed. Therefore, the primary pulley shaft 7 rotates in the direction opposite to that of the transmission input shaft 5 and increased in speed, and the power of the engine 1 is input to the belt type continuously variable transmission 19 in a reverse state. .

  During these travels, the transmission ratio of the belt-type continuously variable transmission 19 is controlled by the transmission controller 40. That is, the target gear ratio is determined based on vehicle speed information obtained from the vehicle speed sensor 43 by the transmission controller 40, throttle opening degree information obtained from an engine controller (not shown), engine speed information, and the like.

  The hydraulic pressure supplied to the primary pulley oil chamber 33 is adjusted so as to achieve this target gear ratio, and the movable sheaves 8b and 10b of the primary pulley 8 and the secondary pulley 10 are displaced. The output of the belt-type continuously variable transmission 19 obtained according to this gear ratio is transmitted to the left and right drive wheels 17 and 18 via the output gear 12, the drive gear 13, the differential gear 14, and the drive shafts 15 and 16. . The drive wheels 17 and 18 are driven by the above-described action to drive the vehicle forward or backward.

  Next, the effect of the present embodiment will be described.

  (1) When the select lever is at the travel position, the generation of creep torque is stopped when the vehicle stops, and the creep torque is generated when it is estimated that the vehicle is likely to start within a short time. Therefore, the durability and fuel consumption of the clutch can be improved while ensuring a good start response of the vehicle.

  (2) When the vehicle is stopped with the select lever at the travel position, the driver often starts the vehicle again. Therefore, when a certain amount of time has elapsed since the vehicle stopped, the possibility of starting the vehicle is high. Therefore, when the time t1 has elapsed since the vehicle stopped, it is estimated that the vehicle is likely to start within a short period of time, and creep torque is generated. Accordingly, creep torque can be generated only when the possibility of vehicle start is high within a short time, and the durability and fuel consumption of the clutch can be improved while ensuring a good start response of the vehicle.

  (3) Since the brake is released when the driver starts the vehicle, when the brake return is detected by the brake stroke sensor 41 or the like, it is estimated that the possibility of starting the vehicle is high within a short time. Therefore, creep torque can be generated only when the possibility of vehicle start is high, and the durability and fuel consumption of the clutch can be improved while ensuring a good vehicle start response.

  (4) Since the driver of the host vehicle is likely to start when the stopped front vehicle starts, the inter-vehicle distance detection device 42 changes the inter-vehicle distance between the host vehicle and the front vehicle while the vehicle is stopped. When it is detected, the possibility of starting the vehicle is estimated within a short time. Therefore, creep torque can be generated only when the possibility of vehicle start is high, and the durability and fuel consumption of the clutch can be improved while ensuring a good vehicle start response.

  (5) It is estimated that the vehicle is likely to start within a short time, and the generation of creep torque is stopped when the time t2 has elapsed since the generation of creep torque. Therefore, it is possible to avoid prolonged generation of creep torque while the vehicle is stopped and to improve the durability and fuel consumption of the clutch.

  The vehicle starting clutch control device of the present invention has been described based on the first embodiment. However, the specific configuration is not limited to these embodiments, and the claims relate to each claim. Design changes and additions are allowed without departing from the spirit of the invention.

  For example, in Example 1, the generation of creep torque is stopped when the vehicle stops, and the creep torque is generated when it is estimated that the driver has requested to start. Furthermore, when the time t2 has elapsed since the generation of the creep torque, the generation of the creep torque is stopped again. Instead of stopping the generation of the creep torque, a weak creep torque that is smaller than the normal creep torque may be generated.

  Moreover, although the possibility of vehicle start within a short time is determined using the three conditions of step S3, step S4, and step S5 in FIG. 2, any one or two conditions may be used. Other conditions may be added.

  In the first embodiment, the start clutch control device is applied to the engagement control of the forward clutch and the reverse brake of the vehicle equipped with the belt type continuously variable transmission, but the vehicle equipped with the stepped automatic transmission or the toroidal continuously variable transmission is shown. The present invention can be applied to various vehicles having a clutch that is fastened at the time of starting and transmits an input torque from a drive source, such as a mounted vehicle, an automatic MT mounted vehicle, a hybrid vehicle, and an electric vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall system diagram showing a drive system and a control system of a vehicle equipped with a belt type continuously variable transmission to which a starting friction element control device according to a first embodiment is applied. 3 is a flowchart illustrating a flow of a starting friction element control process executed by a transmission controller according to the first embodiment. 4 is a time chart of the conventional starting friction element control and the starting clutch control according to the first embodiment.

Explanation of symbols

20 forward clutch 21 reverse brake 40 transmission controller 41 brake stroke sensor 42 inter-vehicle distance detection device

Claims (5)

In a vehicle start friction element control device that controls a start friction element that is mounted on a vehicle and disposed between an engine and a speed change mechanism to generate a creep torque in a slip state,
Creep torque reducing means for reducing creep torque while the vehicle is stopped;
Start possibility estimation means for estimating that the possibility of vehicle start is high within a short period of time while the vehicle is stopped;
A creep torque increasing means for increasing the creep torque while the vehicle is stopped when the possibility of starting the vehicle is estimated to be high by the start possibility estimating means;
A starting friction element control device for a vehicle, comprising: The vehicle starting friction element control device according to claim 1,
The starting frictional element control device for a vehicle, wherein the starting possibility estimating means estimates that the possibility of starting the vehicle is high when a first predetermined time elapses after the vehicle stops. The vehicle starting friction element control device according to claim 1,
A brake return detecting means for detecting a brake return for the driver to release the brake;
The starting frictional element control device for a vehicle, wherein the starting possibility estimating means estimates that the possibility of starting the vehicle is high when the brake return is detected. The vehicle starting friction element control device according to claim 1,
A vehicle distance measuring means for measuring the distance between the host vehicle and the vehicle ahead is provided.
The starting frictional element control device for a vehicle, wherein the starting possibility estimating means estimates that the possibility of starting the vehicle is high when the inter-vehicle distance is changed by the inter-vehicle distance measuring means. The starting friction element control device for a vehicle according to any one of claims 1 to 4,
The vehicle starting friction element control device characterized in that the creep torque increasing means ends the creep torque increase when a second predetermined time elapses from the start of creep increasing without starting the vehicle.

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