JP2012159145A - Apparatus for controlling clutch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus for controlling a clutch which can secure responsiveness in starting an engine at a request of acceleration.SOLUTION: The apparatus 2 for controlling a clutch includes: a clutch C1 configured to break the transmission of rotary torque between the engine 10 of a vehicle 1 and a driving wheel 44; a starter 12 configured to transmit the rotary torque to the stopped engine 10 to start the engine 10; a running state determination unit 78 for determining whether start-up of the engine 10 is failed when starting the engine 10 using the starter 12 at the request of a driver during an engine stop control that stops the engine 10 while the vehicle 1 runs; and a running control unit 74 configured to control the engagement of the clutch C1 and also when the running state determination unit 78 determines that the start-up of the engine 10 is failed, bringing the clutch C1 into engagement before the start-up of the engine 10.

Description

  The present invention relates to a clutch control device.

  In a vehicle that travels using power generated by a power source, an engine is often used as the power source, but the engine cannot generate power by increasing the rotational speed from a state where operation is stopped, It is necessary to operate at the minimum number of revolutions that can continue operation. On the other hand, when the vehicle travels, the vehicle speed may become zero and the rotation of the drive wheels may stop. For this reason, the vehicle is provided with a clutch that switches between transmission and interruption of power by switching the engagement state in the power transmission path from the engine to the drive wheels. Drive while switching the status.

  For example, in the braking force regeneration device described in Patent Document 1, a torque converter disposed between an engine and a transmission is provided with a lock-up mechanism, which is an example of a clutch, according to the traveling state of the vehicle. The lockup mechanism is switched between engagement and release. Further, in the braking force regeneration device described in Patent Document 1, it is possible to transmit power from both sides of the torque converter to the auxiliary equipment provided in the engine, that is, the engine to the auxiliary equipment. The power on the side and the power on the wheel side can be transmitted.

  Further, the braking force regeneration device includes a rotation speed selection means for transmitting a higher rotation speed power among the rotation speeds of the engine side power and the wheel side power transmitted to the auxiliary machine to the auxiliary machine. Is provided. For this reason, when the lock-up mechanism is in the open state, one of the power on the engine side and the power on the wheel side is transmitted to the auxiliary machine, and the auxiliary machine is operated by the transmitted power. Thereby, even when the rotational speed of the wheel is low, the auxiliary machine can be operated more appropriately.

JP 2009-207243 A

  Here, in recent years, a technique for stopping the engine while the vehicle is running has been developed for the purpose of reducing fuel consumption. In such a vehicle, the clutch provided in the power transmission path between the engine and the drive wheels is opened when the engine is stopped. When starting a stopped engine, the engine is started by a starter provided in the engine, and a clutch is engaged to transmit power generated by the engine to the drive wheel side.

  However, when the engine is started due to the driver's acceleration request, the engine may fail to start due to an engine misfire, a starter meshing failure, or the like. As described above, when the engine fails to start, there is a case where the acceleration response becomes slow when attempting to restart the engine and the driver's acceleration request cannot be met.

  The present invention has been made in view of the above, and an object of the present invention is to provide a clutch control device that can ensure responsiveness when starting an engine in response to an acceleration request.

  In order to solve the above-described problems and achieve the object, a clutch control device according to the present invention includes a clutch capable of interrupting transmission of rotational torque between a vehicle engine and drive wheels, and the engine in a stopped state. A starter capable of starting the engine by transmitting rotational torque to the engine, and when the engine is started by the starter according to a driver's request during engine stop control for stopping the engine while the vehicle is running. When it is determined that start failure determination means for determining whether or not start has failed and the clutch engagement control is possible and the start failure determination means determines that the engine has failed to start. And an engagement control means for engaging the clutch before starting the engine.

  In the clutch control device, it is preferable that the start failure determination unit determines whether or not the engine has failed to start based on an engine speed corresponding to an operation command for the starter.

  In the clutch control device, the power transmission path between the engine and the drive wheels has a pair of sheaves on the input side and the output side of the rotational torque, and the sheave includes the sheave between the sheaves. A belt for transmitting rotational torque is wound around the belt, and the belt rotating radius is adjusted by adjusting the clamping force of the belt at the sheave, so that the gear ratio between the sheaves can be adjusted steplessly. A continuously variable transmission is provided, and the sheave is configured to reduce the clamping pressure by a hydraulic pressure generated by an electric pump that operates by electricity and a hydraulic pressure generated by a mechanical pump that operates in accordance with the operation of the engine. The clutch is disposed between the engine and the continuously variable transmission in the power transmission path, and when the engine fails to start, When determined by the start failure determination means, the engagement control means is configured such that the clamping pressure of the belt at the sheave changes according to the hydraulic pressure generated by the electric pump and the hydraulic pressure generated by the mechanical pump. It is preferable to adjust the engaging force of the clutch based on the above.

  The clutch control device according to the present invention engages the clutch before starting the engine when the engine failure control means determines that the engine has failed to start when the engine is started at the request of the driver during engine stop control. Therefore, the engine can be started with the inertia energy of the vehicle, and the responsiveness when starting the engine by the acceleration request can be ensured.

Drawing 1 is a schematic diagram of vehicles provided with a clutch control device concerning an embodiment. FIG. 2 is a flowchart showing an outline of a processing procedure of the clutch control device. FIG. 3 is a flowchart showing an outline of a processing procedure when starting the engine in consideration of the operation of the continuously variable transmission when the engine fails to start.

  Hereinafter, an embodiment of a clutch control device according to the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by this embodiment. In addition, constituent elements in the following embodiments include those that can be easily replaced by those skilled in the art or those that are substantially the same.

Embodiment
Drawing 1 is a schematic diagram of vehicles provided with a clutch control device concerning an embodiment. A clutch control device 2 according to this embodiment is mounted on a vehicle 1. The vehicle 1 is provided with an engine 10 that is an internal combustion engine as a power source during traveling, and rotational torque is transmitted between the engine 10 and a drive wheel 44 of the vehicle 1 between the two. A power transmission path for transmitting the power generated by the engine 10 to the drive wheels 44 is provided.

  The devices constituting the power transmission path will be described. The engine 10 is connected to a torque converter 16 that also functions as torque amplifying means and torque interrupting means. The torque converter 16 is connected to a forward / reverse switching mechanism 20 that can switch the rotational direction of the rotational torque transmitted from the torque converter 16 to an arbitrary direction and transmit it to other devices. Further, the forward / reverse switching mechanism 20 is connected to a continuously variable transmission 30 that constitutes an automatic transmission with the forward / reverse switching mechanism 20. This continuously variable transmission 30 is provided as a CVT (Continuously Variable Transmission) which is a transmission capable of continuously changing the speed ratio between the input rotational speed and the output rotational speed of the rotational torque transmitted from the forward / reverse switching mechanism 20. The belt type continuously variable transmission uses a belt for transmitting torque. The continuously variable transmission 30 provided in this way is provided so that the rotational speed of the rotational torque input from the engine 10 side can be changed and output to the drive wheel 44 side of the vehicle 1 by changing the gear ratio. Yes.

  Specifically, the continuously variable transmission 30 has a pair of sheaves on the rotational torque input side and output side, that is, a primary sheave 32 that rotates by the rotational torque transmitted from the forward / reverse switching mechanism 20; And a secondary sheave 34 that is rotated by rotational torque transmitted from the primary sheave 32. A belt 36 is wound around the primary sheave 32 and the secondary sheave 34, and the rotational torque of the primary sheave 32 is transmitted to the secondary sheave 34 via the belt 36. Further, both the primary sheave 32 and the secondary sheave 34 can adjust the pinching pressure in the width direction of the belt 36, and the rotation radius of the belt 36 to be wound is adjusted by adjusting the pinching pressure. can do. The continuously variable transmission 30 thus determines the rotational radius of the belt 36 when the rotational torque is transmitted between the primary sheave 32 and the secondary sheave 34 via the belt 36 between the primary sheave 32 and the secondary sheave 34. By adjusting both, the gear ratio between sheaves can be changed.

  The continuously variable transmission 30 provided in this way is further connected to the reduction gear 40 so that the rotational torque of the secondary sheave 34 can be transmitted to the reduction gear 40. The speed reduction device 40 can reduce the rotational torque transmitted from the continuously variable transmission 30 and transmit it to the differential device 42. The differential device 42 applies the rotational torque transmitted from the speed reduction device 40 to the left and right. It is possible to transmit to the driving wheel 44. As described above, a power transmission path is configured between the engine 10 and the drive wheels 44 by a plurality of devices and the like.

  Among the devices constituting the power transmission path, the forward / reverse switching mechanism 20 and the continuously variable transmission 30 can be operated by hydraulic pressure. For this reason, these devices are connected to a hydraulic circuit 50 that can adjust the hydraulic pressure applied to each device by having valves and the like, and the suctioned oil is discharged to the hydraulic circuit 50. Thus, a pump that generates hydraulic pressure is connected. Among these, the pump is an electric pump 52 that generates hydraulic pressure using power generated by a motor 54 that is operated by electricity, and a mechanical pump 56 that is a mechanical pump that operates in accordance with the operation of the engine 10 and generates hydraulic pressure. , Is provided. These hydraulic circuits 50, the electric pump 52, the mechanical pump 56, and the devices that are operated by hydraulic pressure such as the forward / reverse switching mechanism 20 are connected by a hydraulic path 58.

  Of the devices that are operated by hydraulic pressure, the forward / reverse switching mechanism 20 disposed between the engine 10 and the continuously variable transmission 30 in the power transmission path is, for example, a frictional engagement, whereby the torque converter 16 is engaged. And the continuously variable transmission 30 are provided so that the engagement of the clutch C1 that can switch between transmission and disconnection of the rotational torque can be performed by hydraulic pressure. For this reason, the forward / reverse switching mechanism 20 can switch the engagement state of the clutch C1 by adjusting the hydraulic pressure. In the continuously variable transmission 30, the clamping pressure of the primary sheave 32 and the secondary sheave 34 can be generated by the hydraulic pressure generated by the electric pump 52 and the hydraulic pressure generated by the mechanical pump 56. It can be adjusted by adjusting the hydraulic pressure. That is, the continuously variable transmission 30 can adjust the gear ratio by adjusting the hydraulic pressure.

  The engine 10 is also provided with a starter 12 that can start the engine 10 by inputting rotational torque to a crankshaft (not shown) of the engine 10 when the engine 10 is stopped. The starter 12 is provided by a motor that is operated by electricity supplied from a battery (not shown) that is used as a power source for each electric device equipped in the vehicle 1, and a transmission mechanism that transmits power generated by the motor to the engine 10. It has been. In the starter 12 provided in this way, the motor is operated by electricity from the battery, and the power generated by the motor is transmitted from the transmission mechanism to the crankshaft of the engine 10 in a stopped state to transmit the crankshaft. The engine 10 is started by rotating. That is, the starter 12 is provided so that the engine 10 can be started by transmitting rotational torque to the stopped engine 10.

  Further, the engine 10 is provided with an engine speed sensor 14 which is a speed detection means for detecting the engine speed, and can detect the speed during operation of the engine 10.

  Engines and devices such as the engine 10 and sensors provided as described above are mounted on the vehicle 1 and connected to an ECU (Electronic Control Unit) 70 that controls each part of the vehicle 1. The ECU 70 is also connected to sensors that detect the state of the driving operation of the driver of the vehicle 1. For example, an accelerator that detects the opening of the accelerator pedal 60 that is operated when the driver adjusts the driving force. A sensor 62 is connected.

  In this way, the ECU 70 to which the devices and sensors are connected can exchange information and signals with these devices and the like, whereby each part of the vehicle 1 is detected by the sensors. Based on the above, the ECU 70 operates under the control. For example, the engine 10 has an intake air amount, a fuel injection amount by an injector (not shown), an ignition timing, an opening degree of an accelerator pedal 60 detected by an accelerator sensor 62, an engine speed detected by an engine speed sensor 14, It operates by being controlled according to the engine coolant temperature and the like.

  The hardware configuration of the ECU 70 that can control each unit in this manner is a known configuration including a processing unit having a CPU (Central Processing Unit) and the like, a storage unit such as a RAM (Random Access Memory), and the like. Omitted.

  The processing unit of the ECU 70 provided in this way includes a traveling state acquisition unit 72 that acquires the traveling state of the vehicle 1 and the state of the driving operation of the driver, a traveling control unit 74 that performs traveling control of the vehicle 1, and the vehicle An engine stop control unit 76 that performs engine stop control, which is control for stopping the engine 10 during the travel of the vehicle 1, and a travel state determination unit 78 that performs various determinations based on the travel state of the vehicle 1 and the driving operation state of the driver And have.

  The clutch control device 2 according to this embodiment is configured as described above, and the operation thereof will be described below. When the vehicle 1 travels, the accelerator opening, which is the operation amount of the accelerator pedal 60 operated by the driver, is detected by the accelerator sensor 62, and the detection result is acquired by the traveling state acquisition unit 72 of the ECU 70. The accelerator opening acquired by the traveling state acquisition unit 72 is transmitted to the traveling control unit 74 of the ECU 70. The traveling control unit 74 performs traveling control of the vehicle 1 based on the driving operation state acquired by the traveling state acquisition unit 72 and the like. When traveling control of the vehicle 1 is performed, the power generated by the engine 10 and the gear ratio of the continuously variable transmission 30 are adjusted according to the traveling state transmitted from the traveling state acquisition unit 72 and the like.

  For example, when the power of the engine 10 is adjusted, the opening of a throttle valve (not shown) included in the engine 10 is adjusted, or the injection amount of fuel injected from a fuel injector (not shown) is adjusted. Thus, desired power is generated in the engine 10. Further, when adjusting the transmission ratio of the continuously variable transmission 30, the hydraulic circuit 50 is controlled to adjust the hydraulic pressure applied to the primary sheave 32 and the secondary sheave 34, and the clamping pressure on the belt 36 by each sheave is adjusted. As a result, the radius of rotation of the belt 36 is adjusted, and the gear ratio is adjusted. As described above, the driving control unit 74 controls the engine 10 and the like based on the state of the driving operation by the driver, and the power generated by the engine 10 is driven through the power transmission path of the continuously variable transmission 30 and the like. 44 and a desired driving force is generated by the drive wheels 44.

  In addition, when it can be determined that the driver does not intend to accelerate the vehicle 1, the vehicle 1 performs engine stop control that is control for stopping the operation of the engine 10 and causing the vehicle 1 to travel by inertia using inertial energy. Do. In this engine stop control, not only the operation of the engine 10 is stopped, but also transmission of rotational torque in the power transmission path between the engine 10 and the drive wheels 44 is interrupted. As described above, the engine stop control that stops the engine 10 and also interrupts the transmission of the rotational torque between the engine 10 and the drive wheels 44 is an engine in which the ECU 70 has a driving operation of the driver acquired by the traveling state acquisition unit 72. The determination is made by the stop control unit 76, and it is performed when the driver can determine that there is no intention to accelerate the vehicle 1.

  Specifically, the engine 10 has a select lever (not shown) that has an accelerator opening detected by the accelerator sensor 62 and can switch the travel range by selecting the operating state of the automatic transmission. When the motive power is operated to an N (neutral) range where the drive wheels 44 do not transmit, the driver can determine that there is no intention to accelerate the vehicle 1. Thus, when the accelerator opening is fully closed and the select lever is operated to the N range, the engine stop control unit 76 determines to perform engine stop control.

  When the engine stop control unit 76 determines that the engine stop control is performed by satisfying the predetermined condition, the travel control unit 74 stops the operation of the engine 10 by stopping the fuel injection control and the ignition control. . Furthermore, the traveling control unit 74 controls the inertial traveling by controlling the hydraulic circuit 50 to open the clutch C1 provided in the forward / reverse switching mechanism 20 and performing these controls.

  During the engine stop control, the clutch C1 provided in the forward / reverse switching mechanism 20 is opened as described above, thereby interrupting the transmission of rotational torque between the torque converter 16 and the continuously variable transmission 30. As a result, the drive wheels 44 and the engine 10 are in a state where transmission of rotational torque is interrupted, and resistance due to rotation of the engine 10 that does not generate power does not occur, so the vehicle 1 has reduced travel resistance. In this state, the inertial running by the kinetic energy based on the vehicle speed when the engine stop control is started is continued.

  As described above, when it is possible to determine that the driver intends to accelerate the vehicle 1 while the engine 10 is stopped by the engine stop control and the vehicle 1 is traveling by inertia, the engine 10 is started. A driving force is generated by the power generated by the engine 10.

  Specifically, the select lever for switching the travel range of the automatic transmission is operated to a range in which driving power can be generated by the drive wheels 44 using power generated by the engine 10, such as a D (drive) range, When the accelerator sensor 62 detects that the accelerator pedal 60 has been depressed, the driver can determine that he / she intends to accelerate the vehicle 1. As described above, when the select lever is operated to the travel range in which the vehicle 1 travels and the accelerator opening is other than fully closed, the engine stop control unit 76 ends the engine stop control and starts the engine 10. Then, the determination is made.

  When the engine stop control unit 76 determines that the engine 10 is to be started by satisfying the predetermined condition, the travel control unit 74 operates the starter 12 together with the fuel injection control and ignition control of the engine 10. . As described above, when the engine 10 is started by controlling each part of the engine 10, the clutch C <b> 1 of the forward / reverse switching mechanism 20 is engaged, and rotational torque is generated between the torque converter 16 and the continuously variable transmission 30. Make it ready for transmission. As a result, the power generated in the engine 10 is transmitted to the drive wheels 44 via the continuously variable transmission 30 and the like, and the vehicle 1 accelerates according to the driving operation of the driver by generating the driving force in the drive wheels 44. To do.

  When the driver makes an acceleration request at the time of engine stop control, the engine 10 is started in this way, thereby controlling each unit so as to perform acceleration according to the driver's request. In some cases, starting may fail. For example, when the power of the starter 12 is transmitted to the engine 10 when the engine 10 is started, the transmission mechanism of the starter 12 is operated, and the gear (not shown) included in the transmission mechanism and the crankshaft rotate together. Power is transmitted to the crankshaft by meshing with a gear (not shown) that engages, but if the meshing between the gears fails, the engine 10 will fail to start. Further, when the engine 10 is operated, a spark is generated by an ignition plug (not shown) to ignite a mixture of fuel and air. However, when the engine 10 is started, a misfire may occur when the ignition plug is ignited. The engine 10 will fail to start.

  Next, the control when the engine 10 fails to start will be described. When the engine 10 is started, the starting state of the engine 10 is determined by the running state determination unit 78 of the ECU 70, and the engine 10 is started. When it determines with having failed, the clutch C1 of the forward / reverse switching mechanism 20 is engaged. In other words, during engine stop control, the clutch C1 of the forward / reverse switching mechanism 20 is released, but when starting the engine 10 based on the driver's acceleration request, if it is determined that starting has failed, the engine The clutch C1 is engaged without waiting for the start of 10.

  In this case, since the vehicle 1 is running inertially, inertial energy is input from the drive wheels 44 to the power transmission path of the vehicle 1. By engaging the clutch C <b> 1 of the forward / reverse switching mechanism 20, Inertial energy is transmitted as rotational torque from the continuously variable transmission 30 side to the torque converter 16 side. Further, since this rotational torque is transmitted from the torque converter 16 to the engine 10, the crankshaft of the engine 10 is rotated by this rotational torque. At that time, by continuously performing fuel injection control and ignition control, the engine 10 becomes capable of autonomous operation.

  In other words, when the clutch C1 of the forward / reverse switching mechanism 20 is engaged during inertial running with the engine 10 stopped, the rotational torque due to inertial energy is transmitted to the engine 10 and the engine 10 is started by pushing. become. If the engine 10 fails to start when the driver requests acceleration, the clutch C1 of the forward / reverse switching mechanism 20 is engaged in this way, and the engine 10 is started by pushing, so that the driving force according to the driver's request is obtained. Is generated by the engine 10.

  FIG. 2 is a flowchart showing an outline of a processing procedure of the clutch control device. Next, a control method of the clutch control device 2 according to the present embodiment, that is, an outline of a processing procedure of the clutch control device 2 will be described. In the clutch control device 2 according to the present embodiment, first, it is determined whether or not engine stop control is being performed (step ST101). This determination is performed by a traveling state determination unit 78 included in the ECU 70. Based on the state of the engine stop control unit 76, the running state determination unit 78 determines whether or not the engine stop control unit 76 that performs engine stop control when a predetermined condition is satisfied performs the engine stop control. Do. Note that the determination of whether or not the engine stop control is being performed may be performed by a method other than the method that is directly based on the control state in the engine stop control unit 76, for example, the engine stop control implementation state. May be set based on the state of the flag. When it is determined that the engine stop control is not being performed by the determination in the traveling state determination unit 78 (step ST101, No determination), the processing procedure is exited.

  On the other hand, when the driving state determination unit 78 determines that the engine stop control is being performed (step ST101, Yes determination), it is next determined whether or not there is a request for starting the engine 10 (step ST101). ST102). This determination is performed by the traveling state determination unit 78 of the ECU 70. The traveling state determination unit 78 determines whether or not there is a request to start the engine 10 based on the accelerator opening detected by the accelerator sensor 62 and acquired by the traveling state acquisition unit 72. That is, when it is detected that the driver is depressing the accelerator pedal 60 based on the accelerator opening, it is determined that the driver is requesting acceleration, and it is determined that there is a request for starting the engine 10.

  If it is determined by this determination that there is no request for starting the engine 10 (step ST102, No determination), this determination is repeated with the engine 10 stopped until a request for starting the engine 10 is made.

  On the other hand, when it is determined that there is a request for starting the engine 10 (step ST102, Yes determination), the engine 10 is started (step ST103). In other words, the engine 10 is controlled by the travel control unit 74 of the ECU 70, and the starter 12 is operated while performing fuel injection control and ignition control.

  Next, it is determined whether or not the engine 10 has failed to start (step ST104). This determination is made by the traveling state determination unit 78 based on the detection results of the sensors that detect the operating state of the engine 10. The running state determination unit 78 is also provided as a start failure determination unit that determines whether or not the start of the engine 10 has failed when the starter 12 starts the engine 10 in response to a driver request during engine stop control. ing. The traveling state determination unit 78 performs this determination based on, for example, the engine speed corresponding to the start command of the starter 12. That is, when the start-up of the crankshaft rotational speed detected by the engine speed sensor 14 after the start command of the starter 12 is issued by the travel control unit 74 at the start control of the engine 10 is smaller than a predetermined change amount. The engine 10 is determined to have failed to start.

  The determination as to whether or not the engine 10 has failed to start may be performed by other methods. For example, the misfire determination of the engine 10 may be performed based on the detection result of the in-cylinder pressure sensor (not shown) that detects the in-cylinder pressure of the engine 10 to determine whether the engine 10 has failed to start. That is, when it is determined that the engine 10 has misfired during the start control of the engine 10, the engine 10 may be determined to have failed to start.

  If it is determined by this determination that the engine 10 has failed to start (step ST104, Yes determination), the clutch C1 is engaged (step ST105). That is, when it is determined that the engine 10 has failed to start, the travel control unit 74 controls the hydraulic circuit 50 while operating the electric pump 52 without waiting for the engine 10 to start successfully. The clutch C1 of the forward / reverse switching mechanism 20 is engaged. As described above, the traveling control unit 74 is provided so as to be able to control the engagement of the clutch C1, and when the traveling state determining unit 78 determines that the engine 10 has failed to start, It is also provided as an engagement control means for engaging the clutch C1.

  In this case, the engagement control of the clutch C1 is performed in the pushing mode, which is a control mode in which the engine 10 is started by transmitting the rotational torque on the drive wheel 44 side to the engine 10 side. That is, when performing the engagement control in the pushing mode, the engine 10 is in a stopped state or rotating at an extremely low rotation, so that the rotational torque on the drive wheel 44 side suddenly increases. 10, a shock associated with the inertia torque of the engine 10 is generated in the power transmission path and the drive wheels 44. For this reason, during engagement control in the pushing mode, the clutch C1 is gradually engaged so that the rotational torque is gradually transmitted to the engine 10 and the engine speed gradually increases in order to reduce such shock. Combine.

  Next, the engine 10 determines whether or not autonomous return is possible (step ST106). In this determination, the engine speed acquired by the traveling state acquisition unit 72 based on the detection result of the engine speed sensor 14 reaches a predetermined speed at which the engine 10 can autonomously return without requiring external force input. Whether or not the vehicle is traveling is determined by the traveling state determination unit 78. A predetermined rotational speed used when determining whether or not the engine 10 can return autonomously is preset and stored in the storage unit of the ECU 70. The traveling state determination unit 78 determines whether or not the engine speed acquired by the traveling state acquisition unit 72 is equal to or higher than the predetermined rotational speed stored in the storage unit of the ECU 70 as described above. Determines whether or not autonomous return is possible. The predetermined rotation speed used when determining whether or not the engine 10 can return autonomously may be a fixed rotation speed, or may be set as appropriate based on the current water temperature or the like.

  If it is determined by this determination that the engine 10 cannot return autonomously (No determination in step ST106), that is, it is determined that the engine speed acquired by the traveling state acquisition unit 72 has not reached a predetermined speed. If so, the clutch C1 engagement control is continued (step ST105). That is, during the engagement control in the pushing mode, the engine speed is gradually increased, so that the engagement control of the clutch C1 is continued until the engine speed becomes equal to or higher than a predetermined speed at which autonomous return can be achieved.

  On the other hand, when it is determined that the autonomous return of the engine 10 is possible (step ST106, Yes determination), the engagement control of the clutch C1 is set to normal control (step ST107). That is, when the engagement control is performed in the pushing mode of the clutch C1, the engagement state of the clutch C1 is controlled so that the rotational torque transmitted from the drive wheel 44 side to the engine 10 side gradually increases. When it is determined that the engine 10 can return autonomously, the engine 10 is in a state where it can generate the power requested by the driver. Therefore, in this case, the clutch C1 performs engagement control during normal vehicle travel. As described above, when the engagement control of the clutch C <b> 1 is set to the normal control, the electric pump 52 is stopped, and the hydraulic pressure is generated by the mechanical pump 56 that is operated by the power generated by the engine 10.

  Similarly, when it is determined that the engine 10 has not failed during start control (step ST103) (step ST104, No determination), the engine 10 can generate the power required by the driver. Therefore, the clutch C1 performs engagement control during normal vehicle travel (step ST107).

  When the clutch control device 2 determines that the engine 10 has failed to start when the engine 10 is started in response to the driver's acceleration request during engine stop control, the travel control unit 74 The clutch C1 of the forward / reverse switching mechanism 20 is immediately engaged. Thus, when the engine 10 is started by the driver's acceleration request at the time of engine stop control, even if the engine 10 fails to start, the engine 10 can be started with the inertial energy of the vehicle 1, and the driver can be started in a short time. It is possible to generate a driving force in response to the request. As a result, it is possible to ensure the responsiveness when starting the engine 10 by the acceleration request.

  Further, when determining whether or not the engine 10 has failed to start, the traveling state determination unit 78 performs control for starting the engine 10 in order to make a determination based on the engine speed with respect to the operation command of the starter 12. It is possible to more reliably determine whether or not the engine has failed to start. Thereby, the engagement control of the clutch C1 when starting the engine 10 by the driver's acceleration request at the time of engine stop control can be performed more appropriately. As a result, the responsiveness when starting the engine 10 in response to the acceleration request can be ensured without excess or deficiency.

  Further, when it is determined that the engine 10 has failed to start, the clutch C1 is gradually engaged, and the rotational torque on the drive wheel 44 side is gradually transmitted to the engine 10 side. The shock at the time of pushing the engine 10 using can be reduced. As a result, it is possible to suppress the deterioration of drive feeling when the engine 10 is started by an acceleration request.

  In addition, when it is determined that the engine 10 has failed to start, the electric pump 52 is stopped when the engine 10 is in a state where it can return autonomously by engaging the clutch C1, so that the electric pump 52 is used. The amount of electricity consumed can be reduced. That is, since the electric pump 52 converts kinetic energy into electric energy and then converts it back into kinetic energy, the efficiency is lower than that of the mechanical pump 56. However, the electric pump 52 is stopped by stopping the electric pump 52. Therefore, it is possible to reduce the amount of electricity consumed by the electric pump 52 with low efficiency. As a result, it is possible to suppress the deterioration of fuel consumption accompanying the increase in the amount of electricity consumed by operating the electric pump 52.

  Further, when there is an acceleration request during engine stop control, the engine 10 is normally started by the starter 12, and the engine 10 is started by engaging the clutch C1 only when the engine 10 fails to start. ing. In this way, the engine 10 is started only by an emergency by engaging the clutch C1, thereby reducing the number of shocks generated by starting the engine 10 by pushing and suppressing the wear of the clutch C1. Can be. As a result, deterioration of drive feeling can be suppressed, and durability of the clutch C1 can be ensured.

  In the clutch control device 2 according to the above-described embodiment, the engine 10 is pushed by engaging the clutch C1 when the engine 10 fails to start during engine stop control. When starting 10, the control may be performed in consideration of the operation of the continuously variable transmission 30.

  That is, when the engine 10 is failed to start and the clutch C1 is engaged and the engine 10 is pushed, the mechanical pump 56 that is operated by the power generated by the engine 10 is stopped when the engine 10 is stopped. ing. For this reason, the hydraulic pressure at the time of engaging the clutch C <b> 1 at the time of starting failure determination of the engine 10 is generated only by the electric pump 52. However, since the electric pump 52 is less efficient than the mechanical pump 56 due to power loss or the like, it is very difficult to generate a large hydraulic pressure only by the electric pump 52 due to the mounting size in the vehicle 1. .

  On the other hand, when the clutch C1 is engaged in order to start the engine 10, the inertia torque of the engine 10 is input to the continuously variable transmission 30, but only the hydraulic pressure generated by the electric pump 52 causes the sheave to the belt 36. It is difficult to secure the clamping pressure, and the belt 36 may slip. For example, slip may occur between the secondary sheave 34 and the belt 36 that rotate together with the rotating member of the power transmission path located on the drive wheel 44 side with respect to the continuously variable transmission 30. For this reason, when the clutch C1 is engaged when it is determined that the engine 10 has failed to start, even if the clutch C1 is controlled to be engaged in consideration of the suppression of the slippage of the belt 36 in the continuously variable transmission 30. Good.

  Specifically, when the clutch C1 is engaged when it is determined that the engine 10 has failed to start, the inertia torque that can be held without causing the belt 36 to slip by the clamping pressure that can be generated by the secondary sheave 34. And the slip control of the clutch C1 is controlled so that the first-axis rotational speed fluctuation, which is the rotational speed fluctuation of the engine 10, torque converter 16, and primary sheave 32, is within the range of the inertia torque. At this time, when the engine speed is increased by starting the engagement of the clutch C1, the mechanical pump 56 is also started by the operation of the engine 10. For this reason, when calculating the inertia torque that can be held by the clamping pressure that can be generated by the secondary sheave 34, the mechanical pump 56 that operates by raising the hydraulic pressure generated by the electric pump 52 and the engine speed is increased. Calculation is based on the clamping pressure that can be generated by the generated hydraulic pressure.

  That is, when the travel state determination unit 78 determines that the engine 10 has failed to start, the travel control unit 74 changes the secondary sheave that changes according to the hydraulic pressure generated by the electric pump 52 and the hydraulic pressure generated by the mechanical pump 56. The engagement force of the clutch C1 is adjusted based on the clamping force of the belt 36 at 34. Thereby, when starting the engine 10 by engaging the clutch C1, the engine 10 can be started without causing the belt 36 to slip.

  FIG. 3 is a flowchart showing an outline of a processing procedure when starting the engine in consideration of the operation of the continuously variable transmission when the engine fails to start. Next, a procedure for starting the engine 10 so that the belt 36 does not slip as described above will be described. In this way, the control for starting the engine 10 by suppressing the slip of the belt 36 when the engine 10 fails to start is determined by the clutch control device 2 according to the embodiment that the start of the engine 10 has failed (step ST104, After the determination (Yes determination), the determination is made until it is determined that the autonomous return of the engine 10 is possible (step ST106, Yes determination). That is, when it is determined that the engine 10 cannot return autonomously (No determination in step ST106), this control is called until it is determined that autonomous return is possible.

  When performing this control, first, it is determined whether or not to start the hydraulic control mode at the time of engine start / return failure determination from engine stop control (step ST201). This determination is performed by the traveling state determination unit 78. The traveling state determination unit 78 starts the hydraulic control mode based on whether or not the engine speed acquired by the traveling state acquisition unit 72 has been increased to a rotational speed at which the mechanical pump 56 can effectively generate hydraulic pressure. It is determined whether or not to do. If it is determined by this determination that the hydraulic pressure control mode at the time of engine start / return failure determination is not started (No determination in step ST201), the processing procedure is exited.

  On the other hand, when it determines with starting the hydraulic control mode at the time of engine start reset failure determination (step ST201, Yes determination), the clamping pressure of the secondary sheave 34 is acquired (step ST202). The clamping pressure of the secondary sheave 34 is acquired by estimating the clamping pressure that can be generated in the secondary sheave 34 by applying hydraulic pressure to the secondary sheave 34 by the traveling state acquisition unit 72. At that time, the traveling state acquisition unit 72 not only provides the hydraulic pressure generated by the electric pump 52 as the hydraulic pressure to be applied to the secondary sheave 34, but also the hydraulic pressure generated by the mechanical pump 56 that has started operating when the engine speed is increased. Including and estimating the clamping pressure.

  As described above, the clamping pressure that can be generated in the secondary sheave 34 is stored in the storage unit of the ECU 70 with the relationship between the hydraulic pressure applied to the secondary sheave 34 and the clamping pressure set in advance in a map state. The traveling state acquisition unit 72 estimates the clamping pressure from the map and the hydraulic pressure. Note that the hydraulic pressure used when acquiring the clamping pressure may be estimated based on the operating state of the electric pump 52 or the mechanical pump 56, or a hydraulic pressure sensor (not shown) for detecting the hydraulic pressure is provided in the hydraulic pressure path. You may acquire from a detection result.

  Next, an inertia torque that can hold the belt 36 is calculated (step ST203). That is, the inertia torque that can be held by the clamping force of the secondary sheave 34 acquired by the traveling state acquisition unit 72 is calculated by the traveling control unit 74 based on the acquired clamping pressure and the friction coefficient between the belt 36 and the secondary sheave 34. To do.

  Next, the equivalent inertia of the axis related to the primary sheave 32 is calculated (step ST204). This equivalent inertia is calculated based on an inertia torque that allows the belt 36 to be held by the secondary sheave 34. That is, since the inertia torque is (equivalent inertia × rotational fluctuation), the inertia inertia related to the primary sheave 32 (the engine 10, the torque converter 16, the clutch C1) based on the inertia torque that allows the belt 36 to be held by the secondary sheave 34. Etc.) is calculated by the travel control unit 74. In this case, the torque converter 16 calculates the equivalent inertia assuming that it is in a lock-up state.

  Next, a change permission first-axis rotation speed change is calculated (step ST205). In other words, the change in the first shaft rotation speed that can allow the variation in the first shaft rotation speed that is the rotation speed of the engine 10, the torque converter 16, and the primary sheave 32 is changed by the secondary sheave 34. Based on the inertia torque that can be held and the equivalent inertia of the shaft related to the primary sheave 32, the travel control unit 74 calculates it. As a result, the permissible value for the change in the number of revolutions is calculated so that the inertia torque of the first axis falls within the range of the inertia torque that allows the secondary sheave 34 to hold the belt 36.

  Next, the engagement pressure of the clutch C1 is calculated (step ST206). That is, the engagement pressure of the clutch C1 that can make the change in the rotational speed of the first axis fall within the allowable value of the rotational speed change calculated by the travel control unit 74 is calculated. In addition, when calculating the engagement pressure of this clutch C1, it calculates in consideration of oil temperature and the engine speed at the time of a control start. When the engagement pressure of the clutch C1 is calculated in this way, the hydraulic circuit 50 is controlled so that the engagement pressure of the clutch C1 becomes the calculated engagement pressure.

  As described above, when starting the engine 10 during the engine stop control, it is determined that the start has failed, and when the clutch C1 is engaged, the engagement force is based on the clamping force of the belt 36 at the secondary sheave 34. By adjusting this, it is possible to suppress the slipping of the belt 36 when the engine 10 is started by pushing. Thereby, when transmitting the rotational torque from the drive wheel 44 side to the engine 10, it can be transmitted efficiently. As a result, the engine 10 can be started early.

  Further, not only the hydraulic pressure that can be generated by the electric pump 52 but also the hydraulic pressure that can be generated by the mechanical pump 56 whose rotation is increased by raising the engine speed, the clamping pressure of the belt 36 is calculated. Thus, the clamping pressure can be calculated with high accuracy. As a result, the engagement pressure of the clutch C1 can be controlled more appropriately, and the engine 10 can be started earlier.

  In the clutch control device 2 according to the above-described embodiment, when the engine 10 is started due to a driver's acceleration request or the like during engine stop control, the clutch that is engaged when it is determined that the start has failed is Although it is the clutch C1 of the switching mechanism 20, the clutch engaged when the engine 10 fails to start may be other than the clutch C1. The clutch that is engaged when it is determined that the engine 10 has failed to start is opened during engine stop control to cut off the rotational torque between the engine 10 side and the drive wheel 44 side. Any clutch other than the clutch C1 of the forward / reverse switching mechanism 20 may be used as long as it can transmit the rotational torque on the drive wheel 44 side to the engine 10 side.

  Further, in the clutch control device 2 described above, the case where the belt-type continuously variable transmission 30 is used as an example of the transmission is described, but the transmission is other than the belt-type continuously variable transmission 30. May be used. As long as the transmission is a transmission that can transmit the rotational torque on the drive wheel 44 side to the engine 10 side even when the engine 10 is stopped, the form is limited to the belt-type continuously variable transmission 30. Absent.

DESCRIPTION OF SYMBOLS 1 Vehicle 2 Clutch control apparatus 10 Engine 12 Starter 14 Engine speed sensor 16 Torque converter 20 Forward / reverse switching mechanism 30 Continuously variable transmission 32 Primary sheave 34 Secondary sheave 36 Belt 44 Drive wheel 50 Hydraulic circuit 52 Electric pump 56 Mechanical pump 58 Hydraulic path 60 accelerator pedal 70 ECU
72 Traveling state acquisition unit 74 Traveling control unit 76 Engine stop control unit 78 Traveling state determination unit C1 Clutch

Claims (3)

A clutch capable of interrupting transmission of rotational torque between the vehicle engine and drive wheels;
A starter capable of starting the engine by transmitting rotational torque to the stopped engine;
Start failure determination means for determining whether or not the engine has failed to start when the engine is started by the starter at the request of a driver during engine stop control for stopping the engine while the vehicle is running;
Engagement control for engaging the clutch before starting the engine when the start failure determination means determines that the engine has failed to start and the clutch engagement control is provided. Means,
A clutch control device comprising:   2. The clutch control device according to claim 1, wherein the start failure determination unit determines whether the start of the engine has failed based on an engine speed corresponding to an operation command of the starter. The power transmission path between the engine and the drive wheels has a pair of sheaves on the input side and output side of the rotational torque, and a belt that transmits the rotational torque between the sheaves is wound around the sheave. A continuously variable transmission is provided that is capable of continuously adjusting the gear ratio between the sheaves by adjusting the rotation radius of the belt by adjusting the clamping force of the belt at the sheave. And
The sheave is capable of generating the pinching pressure by a hydraulic pressure generated by an electric pump that operates by electricity and a hydraulic pressure generated by a mechanical pump that operates in accordance with the operation of the engine.
The clutch is disposed between the engine and the continuously variable transmission in the power transmission path,
When the start failure determination means determines that the engine has failed to start, the engagement control means changes according to the hydraulic pressure generated by the electric pump and the hydraulic pressure generated by the mechanical pump. The clutch control device according to claim 1, wherein an engagement force of the clutch is adjusted based on the clamping pressure of the belt in a sheave.

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