JP2007192335A - Start friction element control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a start friction element control device capable of securing torque necessary for starting irrespective of a traveling environment. <P>SOLUTION: A transmission controller 41 is provided with a forward clutch 20 as the start friction element and a backward brake 21 and a fastening force control unit 41d (fastening force control means) which controls a fastening force for the forward clutch 20 and the backward brake 21. In this case, the start friction element control device provides a torque deficient determination part 41c (torque deficient judgement means) which determines whether or not torque at the time of a start is deficient. The fastening force control unit 41d compensates the fastening force greater than that before reduction compensation after reducibly compensating the fastening force for the forward clutch 20 and the backward brake 21 when the torque is deficient at the time of the start. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a start clutch that is fastened when a vehicle starts and transmits engine torque to drive wheels.

This type of technology includes the engine torque fluctuation shock caused by a sudden throttle operation, etc. by controlling the torque capacity of the starting clutch according to the throttle valve opening, the input / output rotational speed difference of the starting clutch, and the engine speed. Has been disclosed (see, for example, Patent Document 1).
Japanese Patent No. 2784500

  In the above prior art, the torque capacity of the starting clutch is controlled only in accordance with the throttle valve opening, the input / output rotational speed difference of the starting clutch, and the engine speed. For this reason, particularly when the running resistance acting on the drive wheels at the time of starting increases due to the driving environment, the torque required to start the starting cannot be secured and the vehicle may not start.

  The present invention has been made paying attention to the above problems, and an object of the present invention is to provide a starting friction element control device capable of ensuring a torque necessary for starting the start regardless of the driving environment.

  In order to achieve the above object, in the present invention, a starting friction element that is provided between a power source and a drive wheel and that connects and disconnects torque and rotational speed, and a fastening force that controls a fastening force of the starting friction element. A start-up friction element control device provided with a control means, and provided with a torque shortage determination means for determining whether or not the torque at the start is insufficient, and the fastening force control means has a shortage of torque at the start In some cases, after the fastening force is reduced and corrected, the fastening force is corrected to be larger than that before the reduction correction.

  Therefore, in the starting friction element control device of the present invention, the load torque to the engine is reduced by correcting and correcting the fastening force of the starting friction element, and the engine speed is increased. As a result, the inertia energy energy of the engine can be increased. Next, the fastening force of the starting friction element is corrected to increase, and the increased inertia energy can be transmitted as torque to the drive wheel side. Therefore, the torque transmitted to the drive wheel side can be temporarily increased as compared to before the correction of the fastening force of the starting friction element to reduce, so that the vehicle can be started without increasing the throttle opening. it can.

  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 will be described.

  FIG. 1 is an overall system diagram showing a configuration of a drive system and a control system of a vehicle equipped with a belt-type continuously variable transmission including an engine controller 40 and a transmission controller 41.

  A vehicle equipped with a belt-type continuously variable transmission includes an engine 1, a forward / reverse switching mechanism 6 having a starting clutch, a belt-type continuously variable transmission 19 that continuously shifts between input and output, and an output gear 12 that decelerates the output. And a drive gear 13, and left and right drive wheels 17 and 18 driven via a differential gear 14 and left and right drive shafts 15 and 16.

  The engine 1 is connected to a clutch input shaft 5 of a forward / reverse switching mechanism 6 via an engine output shaft 2 and a damper 3.

  The forward / reverse switching mechanism 6 includes a simple planetary gear 22 capable of switching the rotation direction and the 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 and retracted. And a reverse brake 21 as an element.

  The simple planetary gear 22 includes a sun gear 22s that rotates concentrically with the clutch output shaft 7 integrated with the primary pulley shaft, a plurality of pinions 22p that mesh with the sun gear 22s on the outer periphery thereof, a ring gear 22r that meshes with the pinion 22p, and a pinion And a carrier 22c that rotatably supports the carrier 22c.

  The sun gear 22 s is connected to the driven side portion of the forward clutch 20 and the clutch output shaft 7. The carrier 22c is connected to the fixed side portion of the reverse brake 21. The ring gear 22r is connected to the drive side portion of the forward clutch 20 respectively.

  The forward clutch 20 is configured to be switchable between an engaged state in which torque and rotational speed can be transmitted between input and output and a released state in which transmission is impossible.

  The reverse brake 21 is configured to be switchable between a fastening state in which the carrier 22c is fixed to be non-rotatable and a release state in which the carrier 22c is rotatable.

  The belt type continuously variable transmission 19 changes the gear ratio between the input and output shafts of the belt type continuously variable transmission 19 continuously. A primary pulley 8 connected to a primary pulley shaft integral with the clutch output shaft 7, a secondary pulley 10 connected to a secondary pulley shaft 11, a CVT belt 9 spanned between the primary pulley 8 and the secondary pulley 10, It has.

  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 34 is provided on the back surface of the movable sheave 8 b of the primary pulley 8, and a secondary pulley oil chamber 35 is provided on the back surface of the movable sheave 10 b of the secondary pulley 10.

  The pressure oil obtained by suction from the oil tank 30 by the oil pump 31 is supplied to the line pressure control unit 32. In this line pressure control unit 32, the pressure oil is adjusted to a predetermined line pressure and supplied to the hydraulic control unit 33 and the secondary pulley oil chamber 35. By controlling the hydraulic pressure supplied to the primary pulley oil chamber 34 by the hydraulic control unit 33, the movable sheave 8b is relatively moved so as to approach and separate from the fixed sheave 8a. With this configuration, the belt type continuously variable transmission 19 is configured to change the rotation radius of the CVT belt 9 to change speed.

  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 gears 15 and 16 are connected to the side gears to drive the left and right drive wheels 17 and 18.

  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 FIGS.

  The control system includes an engine controller 40 that controls the engine 1, a transmission controller 41 that serves as a fastening force control unit that controls the hydraulic control unit 33 of the forward / reverse switching mechanism 6 and the belt-type continuously variable transmission 19, and these controllers. And sensors connected to each other.

  The engine controller 40 is connected to a throttle opening sensor 42 that detects the throttle opening and an engine speed sensor 43 that detects the rotation speed of the engine output shaft 2 of the engine 1. From these, throttle opening information and engine output shaft speed information are inputted.

  The transmission controller 41 includes a brake sensor 44 that detects the amount of brake depression, a select lever sensor 45 that detects the position of the select lever, a clutch output shaft rotational speed sensor 46 that detects the rotational speed of the clutch output shaft 7, and a vehicle speed. A vehicle speed sensor 47 is connected. From these, brake depression amount information, select lever position information, clutch output shaft rotation speed information, and vehicle speed information information are input.

  In addition, mutual communication is performed through the CAN communication line 50 connecting the engine controller 40 and the transmission controller 41 to exchange control information and sensor input information.

  The engine controller 40 controls the engine 1 based on transmission control information and information from each sensor.

  The transmission controller 41 controls the forward clutch solenoid 48 that controls the hydraulic pressure supplied to the forward clutch 20 and the reverse brake solenoid 49 that controls the hydraulic pressure supplied to the reverse brake 21 based on engine control information and information from each sensor. To do. By this control, the forward clutch 20 and the reverse brake 21 are switched to a completely engaged state, a slip state, and a released state, respectively. The transmission controller 41 controls the hydraulic pressure supplied to the primary pulley oil chamber 34 by a solenoid valve provided in the hydraulic pressure control unit 33 based on engine control information and information from each sensor. By this control, the belt type continuously variable transmission 19 changes speed by changing the rotation radius of the CVT belt 9.

  FIG. 2 is a control block diagram of the transmission controller 41 corresponding to the starting friction element control device of the present invention.

  The transmission controller 41 includes a creep travel request determination unit (creep travel request determination unit) 41a that determines that the driver is requesting creep travel, and a start request determination unit that determines that the driver is about to start the vehicle. (Start request determination means) 41b, a torque shortage determination unit (torque shortage determination means) 41c for determining the shortage of the torque of the vehicle, a forward clutch solenoid 48 and a reverse brake solenoid 49 by outputting control signals to the forward clutch 20 and And a fastening force control unit (fastening force control means) 41d for controlling the fastening force of the reverse brake 21.

  The creep travel request determination unit 41a inputs the throttle opening information of the throttle opening sensor 42 from the engine controller 40, the brake depression amount information from the brake sensor 44, and the select lever position information from the select lever sensor 45. The presence / absence of the driver's creep travel request is determined from the input information, and the result is output to the start request determination unit 41b.

  The start request determination unit 41b includes information on presence / absence of a driver's creep travel request from the creep travel request determination unit 41a, throttle opening information of the throttle opening sensor 42 from the engine controller 40, brake depression amount information from the brake sensor 44, Select lever position information is input from the select lever sensor 45. From these input information, the presence or absence of a driver's start request is determined, and the result is output to the torque shortage determination unit 41c.

  The torque shortage determining unit 41c receives the driver start request presence / absence information from the start request determining unit 41b and the throttle opening information of the throttle opening sensor 42 from the engine controller 40. It is determined whether or not the torque at the start of the vehicle is insufficient from these input information, and the result is output to the fastening force control unit 41d.

  The fastening force control unit 41d receives information from the torque shortage determination unit 41c as to whether or not the torque at the start of the vehicle is insufficient, the engine speed information from the engine controller 40 to the engine speed sensor 43, and the clutch output shaft rotation. The engine output shaft rotation speed information is input from the number sensor 46 and the vehicle speed information is input from the vehicle speed sensor 47. The engagement force of the forward clutch 20 and the reverse brake 21 is calculated from the input information, and a control signal corresponding to the calculated engagement force is output to the forward clutch solenoid 48 and the reverse brake solenoid 49.

  Next, the operation will be described.

[Starting friction element control processing]
FIG. 3 is a flowchart showing a flow of engagement control of the forward clutch 20 and the reverse brake 21 performed in the transmission controller 41 when the road load is large.

  In step S1, it is determined based on information from the select lever sensor 45 whether the select lever is in the forward travel position (D range) or the reverse travel position (R range) and the brake is OFF. If the select lever is in the forward travel position (D range) or the reverse travel position (R range) and the brake is OFF, the driver determines that it has a start request and proceeds to step S2, and the driver starts. If it is not determined that the request is held, the process is terminated.

  In step S2, it is determined whether or not the throttle opening is larger than 0/8. When the throttle opening is larger than 0/8, that is, when the accelerator is depressed, the routine proceeds to step S3. On the other hand, when the throttle opening is 0/8, that is, when the accelerator is not depressed, it is determined that the driver has a start request by creep torque (creep travel request), and the process proceeds to step S9.

  In step S3, normal clutch hydraulic pressure control is performed. The normal clutch hydraulic pressure control means that the forward clutch 20 and the reverse on a road surface (for example, a flat road) with a relatively small road load according to the throttle opening, the input / output rotational speed difference of the forward / reverse switching mechanism 6 and the engine rotational speed. The fastening force control of the brake 21 is shown.

  In step S4, it is determined whether or not the throttle opening is larger than the previous measured value. If the throttle opening is larger than the previous measured value, it is determined that the starting torque is insufficient, and the routine proceeds to step S6 without waiting for the set time described in step S5. On the other hand, if the throttle opening is not larger than the previous measured value, the process proceeds to step S5.

  In step S5, the vehicle does not start even after the set time has elapsed since it was determined in step S1 that the driver has a start request. In other words, if the vehicle speed is 0 (zero), the starting torque is insufficient. And the process proceeds to step S6. On the other hand, if the vehicle has started after the set time has elapsed since it was determined in step S1 that the driver has a start request, the process ends. This set time is an experiment in consideration of the driver's uncomfortable feeling due to the elapsed time from when the driver has a start request until the vehicle starts, deterioration due to slipping of the forward clutch 20 and the reverse brake 21, or the like, or It is obtained by calculation.

  In step S6, clutch oil pressure reduction control for reducing the clutch oil pressure Pc is performed. When the clutch oil pressure Pc is reduced, the torque (hereinafter referred to as load torque) due to the road surface load transmitted from the drive wheels 17 and 18 to the engine 1 is reduced, so that the engine speed Ne is increased. When the engine speed Ne increases, the inertia energy In of the engine 1 increases.

  In step S7, the clutch hydraulic pressure Pc is increased in accordance with the increased engine speed Ne, whereby the increased inertia energy In is transmitted to the drive wheels 17 and 18 side as torque.

  In step S8, it is determined whether or not the vehicle speed has become higher than the set vehicle speed A. If the vehicle speed has become higher than the set vehicle speed A, the clutch hydraulic pressure reduction control and the clutch hydraulic pressure increase control are terminated, and the vehicle speed becomes higher than the set vehicle speed. If not, the process proceeds to step S6. When the vehicle starts to move, the friction between the drive wheels 17 and 18 and the road surface changes from static friction to dynamic friction that is much less resistant than static friction, and the load torque to the engine 1 decreases. The set vehicle speed A may be set to a vehicle speed at which it can be seen that the vehicle has started moving, so that it can be seen that the load torque has decreased.

  Alternatively, one of the following two conditions may be substituted as the end condition for the clutch hydraulic pressure reduction control and the clutch hydraulic pressure increase control, or two or more may be used in combination. The first condition is to detect that the rotational speed difference between the input and output of the forward / reverse switching mechanism 6 obtained from the engine rotational speed sensor 43 and the clutch output shaft rotational speed sensor 46 is sufficiently close to 0 (zero). is there. The second condition is to detect a lockup flag ON indicating a complete engagement command for the forward clutch 20 or the reverse brake 21.

  In step S9, creep clutch hydraulic pressure control is performed. The creep clutch hydraulic pressure control generates a clutch hydraulic pressure Pc that can generate a creep torque when starting on a road surface with a relatively small road load (for example, a flat road).

  In step S10, after the clutch hydraulic pressure Pc is generated, the vehicle does not start even if the set time has elapsed, that is, if the vehicle speed is 0 (zero), the process proceeds to step S11. If the vehicle starts, the process proceeds to step S12. Transition. This set time is obtained by experiment or calculation in consideration of deterioration caused by slipping the forward clutch 20 and the reverse brake 21.

  In step S11, it is determined whether or not the throttle opening is larger than 0/8. When the throttle opening is 0/8, the process is terminated. If the throttle opening is larger than 0/8, it is determined that the accelerator has been stepped on for reasons such as the vehicle has not increased to a sufficient vehicle speed, and the routine proceeds to step S6.

  In step S12, clutch oil pressure reduction control for reducing the clutch oil pressure Pc is performed. When the clutch hydraulic pressure Pc decreases, the load torque to the engine 1 decreases, and the engine speed Ne increases. When the engine speed Ne increases, the inertia energy In of the engine 1 increases.

  In step S13, the clutch hydraulic pressure Pc is increased in accordance with the increased engine speed Ne, whereby the increased inertia energy In is transmitted to the drive wheels 17 and 18 side as torque.

  In step S14, it is determined whether or not the vehicle has started. If the vehicle has started, that is, if the vehicle speed is greater than 0 (zero), the process ends. If the vehicle has not started, the process proceeds to step S12. Return.

[Starting friction element control processing operation]
For example, when starting on a road surface with a relatively small road load (such as a flat road), when the driver steps on the accelerator and the amount of stepping is constant, that is, when starting a normal vehicle, in the flowchart of FIG. Step S1 → Step S2 → Step S3 → Step S4 → Step S5 → END In step S3, clutch hydraulic pressure control is executed so that the vehicle can start smoothly according to the throttle opening, the input / output rotational speed difference of the forward / reverse switching mechanism 6 and the engine rotational speed.

  For example, when the driver is stepping on the accelerator and the amount of stepping is constant when starting on a road surface with a relatively large road load (such as a steep slope) where the vehicle cannot start under normal clutch hydraulic control In the flowchart of FIG. 3, the process proceeds in the order of step S1, step S2, step S3, step S4, step S5, step S6, step S7, and step S8. On the other hand, for example, when the driver is stepping on the accelerator and the amount of stepping is increased when starting on a road surface with a relatively large road load (such as a steep slope) where the vehicle cannot start under normal clutch hydraulic control 3 proceeds in the order of step S1, step S2, step S3, step S4, step S6, step S7, and step S8 in the flowchart of FIG. Steps S6 and S7 are repeated until it is determined in step S8 that the vehicle speed is greater than the set vehicle speed.

  In step S6, clutch hydraulic pressure reduction control is executed so as to reduce the load torque to the engine 1 and increase the engine speed Ne. By increasing the engine speed Ne, the inertia energy In of the engine 1 is increased. In step S7, clutch hydraulic pressure increase control is executed so that the increased inertia energy In is transmitted as torque to the drive wheels 17 and 18 side. If it is determined in step S8 that the vehicle speed is greater than the set vehicle speed, the process proceeds to END.

  For example, when starting on a road surface with a relatively small road load (such as a flat road) and the driver does not step on the accelerator, that is, in the case of normal creep travel, in the flowchart of FIG. The process proceeds in the order of S1, step S2, step S9, step S10, step S11, and END. In step S9, clutch hydraulic pressure control is executed so as to generate creep torque.

  For example, when starting on a road surface with a relatively large road surface load (such as a steep slope) where the vehicle cannot start under normal creep clutch hydraulic control, the driver will not step on the accelerator after the driver has not stepped on the accelerator initially. If so, the process proceeds from step S1, step S2, step S9, step S10, step S6, step S7, and step S8. In step S8, the processing of step S6 and step S7 is repeated until conditions for ending the clutch hydraulic pressure reduction control and clutch hydraulic pressure increase control are satisfied. If it is determined in step S8 that the vehicle speed has become higher than the set vehicle speed, the process proceeds to END. .

  For example, when starting on a road surface with a relatively large road load (such as a steep road) where the vehicle cannot start under normal creep clutch hydraulic control, the driver continues to be in a state where the accelerator is not depressed, that is, creep torque. If the vehicle cannot start with only the torque of step S1, step S1, step S2, step S9, step S10, step S12, step S13, and step S14 proceed. Steps S12 and S13 are repeated until it is determined in step S14 that the vehicle speed has become greater than 0 (zero). In step S12, as in step S6, the clutch hydraulic pressure reduction control is executed so as to reduce the load torque to the engine 1 and increase the engine speed Ne. By increasing the engine speed Ne, the inertia energy In of the engine 1 is increased. In step S13, as in step S7, clutch hydraulic pressure increase control is executed so that the increased inertia energy In is transmitted to the drive wheels 17 and 18 side as torque. If it is determined in step S14 that the vehicle speed has become higher than 0 (zero), the process proceeds to END.

[Starting friction element control processing action]
Next, the operation of the fastening force control unit 41d corresponding to the fastening force control means that is the main component of the present invention will be described.

  <Normal clutch hydraulic control>

  When the engine 1 is in an operating state and the shift lever is moved from the non-traveling position to the forward traveling position such as the D position, the transmission controller 41 switches the valve in the hydraulic control unit 33 to move the forward clutch 20. Control to start supplying pressure oil to At this time, the clutch hydraulic pressure Pc supplied to the forward clutch 20 is lower than the complete engagement pressure, for example, Pc1, and makes the forward clutch 20 slip. As a result, creep torque is generated, and an engagement shock caused by the forward clutch 20 being rapidly engaged at a high pressure is avoided.

  After a predetermined time has elapsed from the start of the slip control, the transmission controller 41 controls the forward clutch 20 to be in a fully engaged state. That is, the transmission controller 41 gradually increases the clutch hydraulic pressure Pc supplied to the forward clutch 20 in accordance with the rotational speed difference between the input and output of the forward clutch 20 obtained from the engine rotational speed sensor 43 and the clutch output shaft rotational speed sensor 46. And finally it is controlled to a completely fastened state.

  On the other hand, when the shift lever is moved from the non-traveling position to the R position, the transmission controller 41 switches the valve in the hydraulic control unit 33 and passes the hydraulic pressure Pc1 lower than the complete engagement pressure to the reverse brake 21 for a predetermined time. Supply until Thereby, the engagement shock which arises when the reverse brake 21 is rapidly engaged at a high pressure is avoided.

  Even at the time of reverse, the hydraulic pressure supplied to the reverse brake 21 is gradually raised after a predetermined time has elapsed from the start of the slip control, and finally fully engaged, as in the case of forward start. .

<Clutch hydraulic control at high load start>
When the running resistance acting on the driving wheels 17 and 18 at the time of starting increases particularly depending on the driving environment, the torque required to start starting cannot be secured, and the vehicle may not start. In this case, it is conceivable to increase the engine opening by increasing the throttle opening and increasing the energy supplied to the engine 1 to secure the torque necessary for starting.

  The throttle opening can be increased by the driver increasing the accelerator, or by adding control to increase the throttle opening regardless of the driver's accelerator operation. However, in the former case, the vehicle cannot start until the driver steps on the accelerator. In particular, in creep running control, the driver's accelerator operation cannot be expected, and if the vehicle does not start, the driver may feel uncomfortable. On the other hand, in the latter case, when controlling the throttle opening, not only the engine side but also the transmission side must be controlled, so the control becomes complicated. Further, since the throttle opening is controlled regardless of the driver's accelerator operation, there is a possibility that the driver may feel uncomfortable.

  By the way, when the engine speed Ne increases and changes, the engine torque Te is stored as inertia energy of the engine 1, and when the engine speed Ne decreases and decreases, the inertia energy of the engine 1 is released as engine torque Te.

  There is little time for the engine torque Te to increase due to the stored inertia energy. However, the running resistance is greatest when starting from a vehicle stop where static friction occurs. Once the vehicle starts to move, a very small dynamic friction is generated as compared with the static friction, so that the running resistance is drastically reduced as compared to when the vehicle is stopped.

  Therefore, in the present embodiment, the engine speed Ne is changed by controlling the forward clutch 20 and the reverse brake 21 which are start clutches so that the vehicle can be moved even a little.

  The engine speed Ne is determined in that the engine torque Te and the load torque to the engine 1 are balanced. Although there is an upper limit depending on the performance of the engine 1, if the load torque on the engine 1 side increases as a tendency, the engine torque Te also increases and the engine speed Ne decreases. On the other hand, if the load torque to the engine 1 side decreases, the engine torque Te also decreases, and the engine speed Ne increases.

  The load torque to the engine 1 side can be controlled by the fastening force of the forward clutch 20 or the reverse brake 21. That is, when the fastening force of the forward clutch 20 or the reverse brake 21 is increased, the load torque to the engine 1 side is increased, and when the fastening force is reduced, the load torque to the engine 1 side is reduced. However, if the fastening force is increased too much, the load torque on the engine 1 side increases the maximum engine torque of the engine 1 and the engine stops.

  From the above, when the fastening force of the forward clutch 20 or the reverse brake 21 is increased, the engine speed Ne decreases, and when the fastening force is reduced, the engine speed Ne increases.

  Specifically, in this embodiment, when the starting torque is insufficient, the clutch hydraulic pressure Pc of the forward clutch 20 or the reverse brake 21 is reduced. Therefore, the load torque to the engine 1 side decreases and the engine speed Ne increases and changes, so that the engine torque Te is stored as the inertia energy In of the engine 1. Next, the clutch hydraulic pressure Pc was increased. Therefore, the load torque to the engine 1 side increases and the engine speed Ne decreases, so that the inertia energy In of the engine 1 is released as the engine torque Te.

  The torque transmitted to the drive wheels 17 and 18 by the released engine torque Te is transmitted to the drive wheels 17 and 18 more than before the clutch hydraulic pressure Pc of the forward clutch 20 or the reverse brake 21 is reduced. Therefore, the vehicle can be started.

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

  (1) In a transmission controller 41 having a forward clutch 20 and a reverse brake 21 as start friction elements, and a fastening force control unit 41d (fastening force control means) for controlling the fastening force of the forward clutch 20 and the reverse brake 21 A torque shortage determining portion 41c (torque shortage determining means) for determining whether or not the torque at the time is insufficient is provided, and the fastening force control portion 41d is provided with the forward clutch 20 and the torque when starting torque is insufficient. After the fastening force of the reverse brake 21 is reduced and corrected, the fastening force before the reduction correction is corrected to be increased.

  Therefore, by reducing and correcting the fastening force of the forward clutch 20 and the reverse brake 21, the load torque to the engine 1 is reduced, and the engine speed Ne is increased. Thereby, the inertia energy energy In of the engine 1 can be increased. Next, the fastening force of the starting friction element is increased and corrected, and the increased inertia energy In energy can be transmitted to the drive wheel side as torque. Accordingly, the torque transmitted to the drive wheel side can be temporarily increased as compared to before the fastening force of the forward clutch 20 and the reverse brake 21 is reduced and corrected, so that the vehicle can be operated without increasing the throttle opening. You can start.

  (2) Furthermore, the fastening force control unit 41d ends the reduction correction and increase correction of the fastening force of the forward clutch 20 and the reverse brake 21 when the vehicle speed exceeds the set vehicle speed.

  Therefore, it is possible to continue the process of performing the reduction correction and the increase correction of the fastening force of the forward clutch 20 and the reverse brake 21 until the vehicle starts. Therefore, the possibility that the vehicle can start can be increased.

  (3) Further, the torque shortage determination unit 41c determines that the torque at the time of start is insufficient when the accelerator depression amount increases. Therefore, it is possible to detect that the driver is about to start earlier because the accelerator depression amount is increased. Therefore, it is possible to ensure a torque that does not make the driver feel uncomfortable in accordance with the driver's request to start.

  (4) Furthermore, a start request determination unit 41b (corresponding to a start request determination unit) that determines whether or not there is a start request from the driver is provided, and the torque shortage determination unit 41c has been determined to have a start request and after a set time has elapsed. When the vehicle speed is 0 (zero), it is determined that the starting torque is insufficient.

  Therefore, it is possible to prevent the vehicle from continuing for a long time due to a lack of torque. Therefore, deterioration due to slippage of the forward clutch 20 and the reverse brake 21 can be reduced, and a torque with less discomfort can be secured for the driver.

  (5) Furthermore, the start request determination unit 41b determines that there is a start request when the select lever is in the forward or backward position, the brake is released, and the accelerator is depressed. Therefore, since it is possible to detect a driver's start request with high accuracy by a simple method, it is possible to ensure a torque that does not make the driver feel uncomfortable according to the driver's start request.

  (6) Further, a creep travel request determination unit 41a for determining a driver's creep travel request is provided, and the start request determination unit 41b is a driver when the creep travel request determination unit 41a determines that there is a creep travel request. Judged that there is a start request.

  Therefore, since it is possible to detect the driver's start request even during creep travel when the driver does not perform the accelerator operation, it is possible to secure torque closer to that during normal creep travel even on road surfaces with high road loads. it can.

  (7) Further, the creep travel request determination unit 41a determines that there is a creep travel request when the select lever is in the forward or backward position, the brake is released, and the accelerator is not depressed. did. Therefore, since it is possible to detect the driver's creep travel request with high accuracy by a simple method, it is possible to ensure a torque that is comfortable for the driver according to the driver's creep travel request.

  In the first embodiment, the torque transmitted to the drive wheel side is corrected to reduce and correct the engagement force of the forward clutch 20 and the reverse brake 21 by performing the correction correction and the decrease correction of the engagement force of the forward clutch 20 and the reverse brake 21. Increased compared to

  On the other hand, the present embodiment is different in that the engine torque Te is further increased by the engine controller 40 by increasing and correcting the engine throttle opening.

  Since the system configuration of the present embodiment is the same as that of the first embodiment, the same reference numerals are given and description thereof is omitted.

  FIG. 4 is a control block diagram of the engine controller 40.

  The engine controller 40 includes a throttle opening control unit (throttle opening control means) 40 a that controls the throttle opening of the engine 1.

  The throttle opening degree control unit 40 a receives throttle opening degree information from the throttle opening degree sensor 42 and engine speed information from the engine speed sensor 43. From the input information, the throttle opening of the engine 1 is calculated and controlled to the calculated throttle opening.

  Next, the operation will be described.

  FIG. 5 is a flowchart showing a flow of throttle opening control of the engine 1 performed in the engine controller 40 when the road load is large, and engagement control of the forward clutch 20 and the reverse brake 21 performed in the transmission controller 41.

  In FIG. 5, the same processes as those in the flowchart of FIG. 3 are denoted by the same reference numerals and description thereof is omitted.

  In this embodiment, step S15 is performed after the process of step S7. In step S15, the throttle opening of the engine 1 is increased regardless of the accelerator depression amount, and the process proceeds to step S8.

  Moreover, step S16 is performed after the process of step S13. In step S16, similarly to step S15, the throttle opening of the engine 1 is increased regardless of the accelerator depression amount, and the process proceeds to step S14. At this time, the fastening force of the forward clutch 20 and the reverse brake 21 is also increased in accordance with the increase in the throttle opening.

  In steps S15 and S16, the engine torque Te can be increased by increasing the throttle opening of the engine 1.

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

  In this embodiment, the following effects can be obtained in addition to the effects described in the first embodiment.

(7) A throttle opening degree control unit 40a for controlling the throttle opening degree of the engine 1 is provided,
The throttle opening control unit 40a corrects the throttle opening to be increased regardless of the accelerator depression amount when the starting torque is insufficient. Therefore, it is possible to increase the engine torque Te, and it is possible to secure the torque at the start.

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. FIG. 3 is a control block diagram of the transmission controller according to the first embodiment. 3 is a flowchart illustrating a flow of clutch hydraulic pressure control of the starting clutch performed in the transmission controller according to the first embodiment. FIG. 6 is a control block diagram of an engine controller according to a second embodiment. 7 is a flowchart illustrating a flow of clutch hydraulic pressure control of a starting clutch performed in an engine controller and a transmission controller according to a second embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine 20 Forward clutch 21 Reverse brake 40 Engine controller 40a Throttle opening degree control part 41 Transmission controller 41a Creep travel request judgment part 41b Start request judgment part 41c Torque shortage judgment part 41d Fastening force control part 42 Throttle opening degree sensor 43 Engine speed Sensor 44 Brake sensor 45 Select lever sensor 46 Clutch output shaft rotational speed sensor 47 Vehicle speed sensor 48 Forward clutch solenoid 49 Reverse brake solenoid

Claims (8)

A starting friction element that is provided between the power source and the drive wheel and connects and disconnects the torque and the rotational speed;
Fastening force control means for controlling the fastening force of the starting friction element;
In a starting friction element control device comprising:
A torque shortage determining means for determining whether or not the torque at the time of start is insufficient;
The fastening force control means, when the torque at the time of starting is insufficient, corrects the fastening force to be increased and then corrects the fastening force before the reduction correction, after correcting the fastening force. apparatus. The starting friction element control device according to claim 1,
The starting friction element control device is characterized in that when the vehicle speed exceeds a set vehicle speed, the fastening force reduction correction and the increase correction are terminated. In the starting friction element control device according to claim 1 or 2,
The starting torque element control device is characterized in that the torque shortage determining means determines that the starting torque is insufficient when the accelerator depression amount is increased. In the starting friction element control device according to any one of claims 1 and 3,
Provide a start request determination means for determining the presence or absence of a driver's start request,
The torque shortage determining means determines that the torque at the start is insufficient when the vehicle speed is substantially zero after a set time has elapsed since it was determined that the start request is present. Friction element control device. The starting friction element control device according to claim 4,
The start request determination means determines that there is a start request when the select lever is in the forward or reverse position, the brake is released, and the accelerator is depressed. means. In the starting friction element control device according to claim 4 or 5,
Equipped with a creep travel request judging means for judging whether or not there is a creep travel request of the driver;
The starting friction element control device, wherein the starting request determining means determines that there is a starting request when it is determined that the creep travel request is present. The starting friction element control device according to claim 6,
The creep travel request determination means determines that there is a creep travel request when the select lever is in the forward or backward position, the brake is released, and the accelerator is not depressed. apparatus. The starting friction element control device according to any one of claims 1 to 7,
Provided with a throttle opening control means for controlling the throttle opening of the engine so that the throttle opening is corrected to be increased regardless of the accelerator depression amount when the starting torque is insufficient. A starting friction element control device.

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