JP2012087828A - Vehicle control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle control device capable of alleviating a load to a clutch mechanism upon idling stop and start control.SOLUTION: An ECU 14 of a vehicle includes: an engine; a belt type continuously variable transmission having a primary pulley in which engine power is input, a secondary pulley from which engine power is output toward a driving wheel and a belt; a machine oil pump 24 capable of supplying oil to the belt type continuously variable transmission by engine power; supply side and discharge side oil pressure control valves 81a and 81b capable of controlling oil pressure in a primary oil pressure chamber 58; and an accumulator 73 capable of supplying oil toward a secondary oil pressure chamber 63; wherein the accumulator 73 is operated and the supply side and discharge side oil pressure control valves 81a and 81b are closed when performing idling stop and start control starting the engine upon start of the vehicle while stopping the engine upon stopping of the vehicle.

Description

  The present invention relates to a vehicle control device.

  2. Description of the Related Art Conventionally, a hydraulic control device that controls the hydraulic pressure of hydraulic oil supplied to a belt type continuously variable transmission is known (for example, see Patent Document 1). The hydraulic control device includes a hydraulic pump that discharges hydraulic oil toward the secondary pulley oil chamber, and a pressure accumulator that accumulates the hydraulic oil discharged from the hydraulic pump. The hydraulic pump is operated by the power of the connected engine, and the pressure accumulator discharges the hydraulic oil toward the secondary pulley oil chamber. And the hydraulic control apparatus respond | corresponds to sudden shift operation by supplying hydraulic fluid toward a secondary pulley oil chamber from a hydraulic pump and an accumulator at the time of sudden shift operation of a belt-type continuously variable transmission.

JP 2008-215592 A

  By the way, in order to improve the fuel consumption of the vehicle, the vehicle may execute idling stop and start control (hereinafter referred to as S & S control) that stops the engine when stopped and starts the engine when starting. In this case, as the engine stops, the hydraulic pump (oil pump) stops, and the supply of hydraulic oil to the belt-type continuously variable transmission stops. For this reason, the vehicle is provided with an electric oil pump that supplies hydraulic oil by an electric motor. During S & S control, hydraulic oil is supplied from the electric oil pump toward the belt-type continuously variable transmission. At this time, the hydraulic oil discharge capacity of the electric oil pump is usually smaller than the hydraulic oil discharge capacity of the mechanical oil pump. For this reason, during the S & S control, it is difficult for the electric oil pump to supply the same amount of hydraulic oil as the hydraulic oil discharge capacity of the mechanical oil pump. Therefore, in a situation where there is a concern about belt slipping when the engine is stopped, during ABS operation, or the like, the conventional hydraulic control device supplies the secondary pulley oil chamber by supplying the hydraulic oil from the pressure accumulator to the secondary pulley oil chamber. The hydraulic pressure in the can be secured.

  However, when the engine is stopped by the S & S control and hydraulic oil is supplied from the pressure accumulator toward the secondary pulley oil chamber, a clamping pressure is generated in the secondary pulley, and tension is generated in the belt stretched over the secondary pulley. . At this time, since the hydraulic oil is not supplied to the primary pulley side, the hydraulic oil is discharged from the primary pulley oil chamber due to the tension generated in the belt, and the primary pulley may operate to the downshift side. When the primary pulley is operated to the downshift side, the rotation speed of the primary pulley is increased accordingly. Here, a clutch mechanism for connecting the engine and the primary pulley is provided between the engine and the belt-type continuously variable transmission. For this reason, the differential rotation between the rotation speed on the engine side and the rotation speed on the belt-type continuously variable transmission side is increased across the clutch mechanism, and the clutch mechanism is connected when the engine and the primary pulley are connected by the clutch mechanism. It is assumed that a large load is applied to the.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vehicle control device that can reduce the load on the clutch mechanism during idling stop-and-start control.

  The vehicle control device according to the present invention includes an engine, a first pulley to which engine power is input, a second pulley for outputting engine power to drive wheels, and a first pulley and a second pulley. A belt-type continuously variable transmission having a belt stretched over, a clutch mechanism that connects the engine and the belt-type continuously variable transmission, and transmits engine power to the belt-type continuously variable transmission; An oil pump capable of supplying oil to the belt-type continuously variable transmission, a hydraulic control valve capable of controlling the hydraulic pressure in the first hydraulic chamber of the first pulley, and a second pulley of the belt-type continuously variable transmission. A vehicle control device capable of controlling a vehicle including a pressure accumulator capable of supplying oil toward the second hydraulic chamber, wherein the engine is stopped when the vehicle is stopped, and the engine is stopped when the vehicle is started. Eye to start When running ring stop-and-start control, it actuates the accumulator, characterized in that to close the hydraulic control valve.

  In this case, the hydraulic control valve includes a supply-side hydraulic control valve capable of controlling the hydraulic pressure of the oil supplied toward the first hydraulic chamber of the first pulley, and the oil discharged from the first hydraulic chamber of the first pulley. It is preferable to have a discharge-side hydraulic control valve capable of controlling the hydraulic pressure, and simultaneously close the supply-side hydraulic control valve and the discharge-side hydraulic control valve when executing the idling stop-and-start control.

  In this case, the vehicle further includes a torque converter with a lock-up mechanism that connects the engine and the clutch mechanism and transmits engine power to the clutch mechanism, and changes in the gear ratio of the belt-type continuously variable transmission When the amount and the change rate are within the preset change amount and the set change rate, it is preferable to execute the clutch engagement by the clutch mechanism after releasing the lockup engagement by the lockup mechanism.

  The vehicle control device according to the present invention can operate the pressure accumulator during the idling stop-and-start control to supply oil toward the second hydraulic chamber of the second pulley, and close the hydraulic control valve. Thus, the hydraulic pressure in the first hydraulic chamber of the first pulley can be maintained. For this reason, even if the pinching pressure is generated in the second pulley and the belt is tensioned, the first pulley can secure the pinching pressure against the belt tension, so that the first pulley is difficult to operate to the downshift side. Become. Therefore, an increase in the differential rotation between the input side and the output side of the clutch mechanism can be suppressed, and the load on the clutch mechanism can be reduced.

FIG. 1 is a diagram illustrating a vehicle to which an ECU according to an embodiment of the present invention is applied. FIG. 2 is a diagram illustrating a hydraulic control apparatus to which the ECU according to the embodiment of the present invention is applied. FIG. 3 is a flowchart showing an example of hydraulic control of the hydraulic control device by the ECU. FIG. 4 is a flowchart showing an example of engagement control of the forward / reverse switching mechanism by the ECU.

  Hereinafter, an embodiment of a vehicle 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.

Embodiment
FIG. 1 is a diagram illustrating a vehicle to which an ECU according to an embodiment of the present invention is applied, and FIG. 2 is a diagram illustrating a hydraulic control device to which the ECU according to the embodiment of the present invention is applied. As shown in FIG. 1, a vehicle 1 includes an engine 5 serving as a power source, a torque converter 6 coupled to the engine 5, a forward / reverse switching mechanism (clutch mechanism) 7 coupled to the torque converter 6, and a forward / rearward travel. A belt type continuously variable transmission 8 connected to the switching mechanism 7 is provided, and these constitute a part of the power transmission path of the vehicle 1. As shown in FIG. 2, the vehicle 1 includes a hydraulic control device 13 that can supply hydraulic oil to the power transmission path. The vehicle 1 is configured to be controllable by an ECU 14 that functions as a vehicle control device that controls the vehicle 1.

  For example, a gasoline engine or a diesel engine is used as the engine 5, and the piston reciprocates in the central axis direction of the cylinder formed in a cylindrical shape, and the crankshaft 15 converts the reciprocating motion of the piston into a rotational motion. Output power.

  The torque converter 6 is a kind of fluid clutch, and transmits the power output from the engine 5 to the forward / reverse switching mechanism 7 through oil as hydraulic oil. The torque converter 6 has a lock-up mechanism, and increases the output torque from the engine 5 or transmits it to the forward / reverse switching mechanism 7 with the output torque as it is.

  The belt-type continuously variable transmission 8 includes a primary shaft 55 serving as an input shaft and a secondary shaft 60 serving as an output shaft. The belt-type continuously variable transmission 8 changes the rotation speed of the primary shaft 55 rotated by the power input from the forward / reverse switching mechanism 7 to the desired rotation speed of the secondary shaft 60 according to the driving state of the vehicle 1. Output. A detailed description of the torque converter 6, the forward / reverse switching mechanism 7 and the belt type continuously variable transmission 8 will be described later.

  Therefore, when the engine 5 is driven in the vehicle 1, the power output from the engine 5 is transmitted to the torque converter 6 via the crankshaft 15. Then, the power with the output torque amplified by the torque converter 6 or the power with the output torque transmitted as it is is transmitted to the forward / reverse switching mechanism 7 and is changed to a desired rotational direction by the forward / backward switching mechanism 7. The power in the desired rotational direction is input to the belt-type continuously variable transmission 8, and the primary shaft 55 that rotates by the input power has a secondary speed according to a predetermined speed ratio of the belt-type continuously variable transmission 8. The rotational speed of the shaft 60 is changed. The power from the secondary shaft 60 whose rotation speed has been changed by the belt-type continuously variable transmission 8 is transmitted to the drive wheels via a reduction gear and a differential device (not shown), and the drive wheels rotate, whereby the vehicle 1 Runs.

  Next, the torque converter 6 will be described. The torque converter 6 includes a pump impeller 20, a turbine runner 21, a stator 22, and a lockup clutch 23. Reference numeral 24 denotes a mechanical oil pump (oil pump) that is operated by the power of the engine 5.

  The pump impeller 20 is connected to a front cover 25, and the front cover 25 is connected to the crankshaft 15 via a drive plate 26 of the engine 5. Therefore, power generated from the engine 5 is transmitted to the pump impeller 20 via the crankshaft 15 and the front cover 25, and the transmitted power is transmitted to the turbine runner 21 via oil.

  The turbine runner 21 is disposed so as to face the pump impeller 20, and the turbine runner 21 is connected to the input shaft 38 of the forward / reverse switching mechanism 7. For this reason, the turbine runner 21 transmits the power of the crankshaft 15 transmitted from the pump impeller 20 through the oil to the input shaft 38 of the forward / reverse switching mechanism 7 disposed on the output side.

  The stator 22 is provided between the pump impeller 20 and the turbine runner 21 and is fixed to a housing (not shown) via a one-way clutch 31.

  The lockup clutch 23 is provided between the turbine runner 21 and the front cover 25 and is connected to the input shaft 38. The lockup clutch 23 is supplied with oil from the hydraulic control device 13 to a torque converter hydraulic chamber formed by the pump impeller 20 and the front cover 25, and performs a fastening operation and a fastening release operation by the oil pressure of the oil. For this reason, when the lockup clutch 23 is engaged, the pump impeller 20 and the turbine runner 21 are engaged, and the power of the crankshaft 15 can be directly transmitted to the turbine runner 21.

  Next, the forward / reverse switching mechanism 7 will be described. The forward / reverse switching mechanism 7 includes a planetary gear mechanism 41, a forward clutch 42, and a reverse brake 43. The planetary gear mechanism 41 includes a sun gear 44, a pinion 45, and a ring gear 46.

  The sun gear 44 is connected to the input shaft 38, and a plurality of pinions 45 are arranged around the sun gear 44. Each pinion 45 is held by a switching carrier 47 that is supported around the sun gear 44 so as to be able to revolve integrally. The switching carrier 47 is connected to the input shaft 38 via the forward clutch 42 at the outer peripheral end thereof. The ring gear 46 meshes with each pinion 45 held by the switching carrier 47 and is connected to the reverse brake 43.

  The forward clutch 42 is subjected to engagement control by oil supplied from the hydraulic control device 13. When the forward clutch 42 is disengaged, the power from the engine 5 transmitted to the input shaft 38 is transmitted to the sun gear 44. On the other hand, when the forward clutch 42 is engaged, the power from the engine 5 transmitted to the input shaft 38 is directly transmitted to the switching carrier 47 without the switching carrier 47, the sun gear 44, and each pinion 45 rotating relative to each other. Is done.

  The reverse brake 43 is subjected to engagement control by oil supplied from the hydraulic control device 13. When the reverse brake 43 is engaged, the ring gear 46 is fixed. When the reverse brake 43 is disengaged, the ring gear 46 is released.

  Therefore, the forward / reverse switching mechanism 7 engages the forward clutch 42 and disengages the reverse brake 43 when the power of the engine 5 is in the rotational direction in which the vehicle 1 moves forward. On the other hand, the forward / reverse switching mechanism 7 disengages the forward clutch 42 and engages the reverse brake 43 when the power of the engine 5 is in the rotational direction in which the vehicle 1 moves backward.

  Next, the belt type continuously variable transmission 8 will be described. The belt type continuously variable transmission 8 includes a primary pulley (first pulley) 50 connected to the output side of the forward / reverse switching mechanism 7 and a secondary pulley (second pulley) provided to face the primary pulley 50. 51 and a belt 52 stretched around a primary pulley 50 and a secondary pulley 51.

  The primary pulley 50 includes a primary shaft 55 connected to the output side of the forward / reverse switching mechanism 7, a primary fixed sheave 56 fixed to the primary shaft 55, and a primary movable sheave 57 slidably mounted on the primary shaft 55. And a primary hydraulic chamber (first hydraulic chamber) 58 for moving the primary movable sheave 57 in the axial direction with respect to the primary fixed sheave 56. The primary fixed sheave 56 and the primary movable sheave 57 face each other, and a substantially V-shaped primary groove V1 is formed between them.

  The primary shaft 55 has a first hydraulic oil passage 55a and a second hydraulic oil passage 55b at its axis. The first hydraulic fluid passage 55 a connects the primary hydraulic chamber 58 and the hydraulic control device 13. Oil is supplied from the hydraulic control device 13 to the primary hydraulic chamber 58 in the first hydraulic oil passage 55a. Further, the second hydraulic oil passage 55 b connects the space accommodating the primary pulley 50 and the hydraulic control device 13. Oil that serves as lubricating oil is supplied from the hydraulic control device 13 to the lubricated portion of the primary pulley 50 to the second hydraulic oil passage 55b. The primary shaft 55 is provided with an input shaft rotation sensor 59 that detects the number of rotations, and the input shaft rotation sensor 59 is connected to the ECU 14.

  The primary movable sheave 57 is configured to be movable in the axial direction of the primary shaft 55 with respect to the primary fixed sheave 56. The primary movable sheave 57 moves in the axial direction of the primary shaft 55 by controlling the hydraulic pressure in the primary hydraulic chamber 58 by the oil supplied from the hydraulic control device 13 via the first hydraulic oil passage 55a. In other words, the primary fixed sheave 56 can be approached and separated.

  Similarly, the secondary pulley 51 also includes a secondary shaft 60 provided in parallel with the primary shaft 55, a secondary fixed sheave 61 fixed to the secondary shaft 60, and a secondary movable sheave 62 slidably mounted on the secondary shaft 60. And a secondary hydraulic chamber 63 for moving the secondary movable sheave 62 in the axial direction with respect to the secondary fixed sheave 61. The secondary fixed sheave 61 and the secondary movable sheave 62 face each other, and a substantially V-shaped secondary groove V2 is formed between them.

  The secondary shaft 60 has a third hydraulic oil passage 60a at its axis. The third hydraulic oil passage 60 a connects the secondary hydraulic chamber 63 and the hydraulic control device 13. Oil is supplied from the hydraulic control device 13 to the secondary hydraulic chamber 63 in the third hydraulic oil passage 60a. The secondary shaft 60 is provided with an output shaft rotation sensor 64 that detects the number of rotations, and the output shaft rotation sensor 64 is connected to the ECU 14.

  The secondary movable sheave 62 is configured to be movable in the axial direction of the secondary shaft 60 with respect to the secondary fixed sheave 61. The secondary movable sheave 62 moves in the axial direction of the secondary shaft 60 by controlling the hydraulic pressure in the secondary hydraulic chamber 63 by the oil supplied from the hydraulic control device 13 via the third hydraulic oil passage 60a. In other words, the secondary fixed sheave 61 can be approached or separated.

  The belt 52 is a metal endless belt and is wound around the primary groove V1 and the secondary groove V2. Then, by controlling the hydraulic pressures of the primary hydraulic chamber 58 and the secondary hydraulic chamber 63 and appropriately changing the widths of the grooves V1 and V2 of the primary pulley 50 and the secondary pulley 51, the winding radius of the belt 52 is changed, As a result, the speed ratio of the belt type continuously variable transmission 8 is set to a desired speed ratio. Although not shown, a hydraulic control unit for the secondary pulley 51 is also included.

  Next, the hydraulic control device 13 will be described with reference to FIG. The hydraulic control device 13 includes the mechanical oil pump 24 that is a main hydraulic source, an electric oil pump 71 that is an auxiliary hydraulic source, a hydraulic control circuit 72 that is supplied with oil from the hydraulic source, and oil. And an accumulator 73 for accumulating pressure.

  The mechanical oil pump 24 sucks, pressurizes, and discharges oil stored in the oil pan 75. The mechanical oil pump 24 can be operated by the power of the engine 5. For this reason, the mechanical oil pump 24 increases the amount of oil discharged as the rotational speed of the engine 5 increases, and the discharge pressure from the mechanical oil pump 24 thereby increases. The mechanical oil pump 24 supplies oil to the hydraulic control circuit 72.

  The electric oil pump 71 sucks, pressurizes, and discharges hydraulic oil stored in the oil pan 75. The electric oil pump 71 can supply oil by an electric motor 77 that is operated by electric power supplied from a battery (not shown). The electric oil pump 71 supplies hydraulic oil to the hydraulic control circuit 72. At this time, the oil discharge capacity of the electric oil pump 71 is smaller than the oil discharge capacity of the mechanical oil pump 24. A check valve 78 is provided on the discharge side of the electric oil pump 71 to prevent backflow of oil.

  The accumulator 73 stores and accumulates oil discharged from the mechanical oil pump 24. The accumulator 73 supplies oil toward the secondary hydraulic chamber 63. Although details will be described later, the accumulator 73 accumulates pressure when the S & S control is not executed, but supplies oil toward the secondary hydraulic chamber 63 when the S & S control is executed.

  The hydraulic control circuit 72 includes a hydraulic control valve 81 configured by a spool valve, an electromagnetic control valve 82 configured by an electromagnetic solenoid, and a plurality of oil passages L1 to L3. The plurality of oil passages L <b> 1 to L <b> 3 are directed to the first oil passage L <b> 1 that supplies oil toward the primary hydraulic chamber 58, the second oil passage L <b> 2 that discharges oil from the primary hydraulic chamber 58, and the secondary hydraulic chamber 63. And a third oil passage L3 for supplying oil.

  The hydraulic control valve 81 has a supply-side hydraulic control valve 81a provided in the first oil passage L1, and a discharge-side hydraulic control valve 81b provided in the second oil passage L2. The supply-side hydraulic control valve 81a is configured to be able to open and close the first oil passage L1, opens when oil is supplied, and closes when oil is discharged. The supply-side hydraulic control valve 81a supplies oil to the primary hydraulic chamber 58 by opening the valve, but does not supply oil to the primary hydraulic chamber 58 by closing the valve. The discharge-side hydraulic control valve 81b is configured to be able to open and close the second oil passage L2, and opens when oil is supplied, and closes when oil is discharged. The discharge side hydraulic control valve 81b discharges oil from the primary hydraulic chamber 58 by opening the valve, but does not discharge oil from the primary hydraulic chamber 58 by closing.

  The electromagnetic control valve 82 is provided in the third oil passage L3, a supply-side electromagnetic control valve 82a that opens and closes the supply-side hydraulic control valve 81a, a discharge-side electromagnetic control valve 82b that opens and closes the discharge-side hydraulic control valve 81b. And an accumulator opening electromagnetic control valve 82c. The supply side electromagnetic control valve 82a, the discharge side electromagnetic control valve 82b, and the pressure accumulation release electromagnetic control valve 82c are connected to the ECU 14. The supply-side electromagnetic control valve 82a supplies oil to the supply-side hydraulic control valve 81a when in the excited state under the control of the ECU 14, and the oil is discharged from the supply-side hydraulic control valve 81a when in the demagnetized state. The discharge-side electromagnetic control valve 82b supplies oil to the discharge-side hydraulic control valve 81b when it is in an excited state under the control of the ECU 14, and oil is discharged from the discharge-side hydraulic control valve 81b when it is in a demagnetized state. The Further, the pressure accumulation release electromagnetic control valve 82c supplies oil to the secondary hydraulic chamber 63 when it is in an excited state under the control of the ECU 14, and does not supply oil to the secondary hydraulic chamber 63 when it is in a demagnetized state.

  Here, the hydraulic control of the primary hydraulic chamber 58 will be described. When raising the hydraulic pressure in the primary hydraulic chamber 58, the ECU 14 excites the supply-side electromagnetic control valve 82a while demagnetizing the discharge-side electromagnetic control valve 82b. When the supply-side electromagnetic control valve 82a is excited, oil is supplied to the supply-side hydraulic control valve 81a, whereby the supply-side hydraulic control valve 81a is opened and oil is supplied to the primary hydraulic chamber 58. On the other hand, when the discharge-side electromagnetic control valve 82b is demagnetized, the oil is discharged from the discharge-side hydraulic control valve 81b, whereby the discharge-side hydraulic control valve 81b is closed and the oil is not discharged from the primary hydraulic chamber 58. As a result, the hydraulic pressure in the primary hydraulic chamber 58 increases.

  On the other hand, when lowering the hydraulic pressure in the primary hydraulic chamber 58, the ECU 14 demagnetizes the supply-side electromagnetic control valve 82a while exciting the discharge-side electromagnetic control valve 82b. When the supply-side electromagnetic control valve 82a is demagnetized, oil is discharged from the supply-side hydraulic control valve 81a, whereby the supply-side hydraulic control valve 81a is closed and no oil is supplied to the primary hydraulic chamber 58. On the other hand, when the discharge-side electromagnetic control valve 82b is excited, oil is supplied to the discharge-side hydraulic control valve 81b, whereby the discharge-side hydraulic control valve 81b is opened and the oil is discharged from the primary hydraulic chamber 58. As a result, the hydraulic pressure in the primary hydraulic chamber 58 decreases.

  As described above, the oil pressure control device 13 is supplied with oil from at least one of the mechanical oil pump 24 and the electric oil pump 71 to the oil pressure control circuit 72, and the oil pressure control circuit 72 is controlled by the ECU 14. The gear ratio of the belt type continuously variable transmission 8 can be controlled to a desired gear ratio by controlling the oil pressure in the hydraulic chamber 58 and the secondary hydraulic chamber 63.

  Further, the hydraulic control device 13 can control the forward or reverse switching in the forward / reverse switching mechanism 7 by controlling the hydraulic pressure of the oil supplied to the forward clutch 42 and the reverse brake 43. Further, the hydraulic control device 13 can control the hydraulic pressure of oil supplied to the lockup clutch 23 to control the engagement operation and the engagement release operation of the lockup clutch 23 in the torque converter 6.

  The ECU 14 controls the vehicle 1 and controls, for example, the engine 5 and the belt type continuously variable transmission 8 that are part of the power transmission path of the vehicle 1. Specifically, the ECU 14 controls the operation of the engine 5 based on various input signals and various maps input from sensors attached to various parts of the vehicle 1. For example, in the engine 5, the ECU 14 performs injection control of a fuel injection valve (not shown), throttle opening control of a throttle valve (not shown) for controlling the intake air amount of the engine 5, ignition control of a spark plug (not shown), and the like.

  The ECU 14 controls the driving of the belt-type continuously variable transmission 8, particularly the gear ratio, based on various input signals and various maps input from sensors attached to various parts of the vehicle 1. The forward / reverse switching of the forward / reverse switching mechanism 7 is controlled. That is, the ECU 14 controls the torque converter 6, the forward / reverse switching mechanism 7, and the belt type continuously variable transmission 8 by performing operation control of the electric oil pump 71, hydraulic control of the hydraulic control circuit 72, and the like.

  That is, the ECU 14 is connected to the fuel injection valve, the throttle valve, and the spark plug of the engine 5 and is also connected to the electric oil pump 71 and the hydraulic pressure control circuit 72, and the engine speed detected by various sensors, the throttle opening. The driving is controlled based on the driving state such as the degree and the accelerator opening degree.

  Here, the ECU 14 performs idling stop-and-start control (hereinafter referred to as S & S control) for stopping the engine 5 when the vehicle 1 is stopped and starting the engine 5 when the vehicle 1 is started in order to improve the fuel efficiency of the vehicle 1. Running. The term “when the vehicle 1 is stopped” includes not only the stop of the vehicle 1 but also the deceleration state of the vehicle 1 immediately before the vehicle 1 stops. Hereinafter, the S & S control by the ECU 14 will be specifically described.

  When the vehicle 1 decelerates and stops, the ECU 14 determines that the vehicle 1 stops and stops the engine 5. The stop of the engine 5 is to stop fuel injection from a fuel injection valve provided in the engine 5. When the engine 5 is stopped after the fuel injection is stopped, the operation of the mechanical oil pump 24 is stopped, so that oil cannot be supplied to the hydraulic control circuit 72. Therefore, the ECU 14 supplies the oil toward the hydraulic control circuit 72 by operating the electric motor 77 and operating the electric oil pump 71 simultaneously with the stop of the engine 5. At this time, the discharge capacity of the electric oil pump 71 is smaller than the discharge capacity of the mechanical oil pump 24. For this reason, the hydraulic pressure of the oil supplied to the primary hydraulic chamber 58 and the secondary hydraulic chamber 63 decreases, and the hydraulic pressure of the oil supplied to the forward / reverse switching mechanism 7 decreases. At this time, the ECU 14 opens the pressure accumulation electromagnetic control valve 82c and releases the oil accumulated in the accumulator 73, thereby supplying the oil toward the secondary hydraulic chamber 63.

  When the oil pressure of the oil supplied to the forward / reverse switching mechanism 7 decreases, the forward / backward switching mechanism 7 disengages the forward clutch 42 and the reverse brake 43. Thereby, in the forward / reverse switching mechanism 7, power transmission from the engine 5 to the belt-type continuously variable transmission 8 is interrupted.

  When the hydraulic pressure of the oil supplied to the primary hydraulic chamber 58 is reduced, the width of the primary groove V1 is easily widened. On the other hand, oil is supplied from the accumulator 73 to the secondary hydraulic chamber 63 to increase the hydraulic pressure, and a pinching pressure is generated in the secondary pulley 51. Thereby, since the secondary movable sheave 62 is pressed toward the belt 52, the width of the secondary groove V2 is narrowed. When the width of the secondary groove V2 is reduced, tension is applied to the belt 52, and the primary pulley 51 is easily operated to the downshift side by the tension generated in the belt 52. Thereby, the belt-type continuously variable transmission 8 easily changes its gear ratio to the start side (low side).

  Therefore, the ECU 14 performs hydraulic control of the hydraulic control device 13 shown in FIG. 3 during S & S control. FIG. 3 is a flowchart showing an example of hydraulic control of the hydraulic control device by the ECU. First, the ECU 14 determines whether or not S & S control is being executed (step S10). That is, when the ECU 14 determines that the vehicle 1 is stopped and stops the engine 5, the ECU 14 determines that the S & S control has been executed (Yes). On the other hand, when the ECU 14 determines that the S & S control is not being executed (No), the hydraulic pressure control is terminated.

  If ECU14 determines with S & S control being performed, it will determine whether the pressure accumulation of the accumulator 73 was open | released (step S11). That is, the ECU 14 determines that the accumulated pressure of the accumulator 73 is released (Yes) when the accumulated pressure release electromagnetic control valve 82c is opened. On the other hand, if the ECU 14 determines that the accumulated pressure in the accumulator 73 is not released (No), the hydraulic pressure control is terminated.

  Subsequently, when the ECU 14 determines that the accumulated pressure in the accumulator 73 has been released, the ECU 14 controls the supply side electromagnetic control valve 82a and the discharge side electromagnetic control valve 82b to demagnetize, thereby supplying the supply side hydraulic control valve 81a and the discharge side hydraulic control. The valve 81b is closed simultaneously (step S12). When the supply-side hydraulic control valve 81a and the discharge-side hydraulic control valve 81b are closed, the oil pressure in the primary hydraulic chamber 58 is maintained in the primary hydraulic chamber 58 because neither oil is supplied nor discharged. For this reason, during S & S control, the hydraulic pressure in the primary hydraulic chamber 58 is unlikely to decrease, and even if the width of the secondary groove V2 is narrowed and tension is applied to the belt 52, the primary pulley 50 is difficult to operate to the downshift side. . As a result, the belt-type continuously variable transmission 8 does not easily shift down its gear ratio to the start side (low side).

  Thereafter, the ECU 14 suppresses the sudden shift operation of the belt-type continuously variable transmission 8 due to the opening of the supply-side hydraulic control valve 81a and the discharge-side hydraulic control valve 81b when the execution of the S & S control is cancelled. Then, the integral term of the feedback control relating to the shift operation is cleared (step S13).

  With the hydraulic control of the hydraulic control device 13 shown in FIG. 3, the belt-type continuously variable transmission 8 is less likely to shift down its gear ratio to the starting side (low side). In other words, the belt-type continuously variable transmission 8 can maintain its speed ratio or can be gradually shifted down. At this time, when the belt type continuously variable transmission 8 is gently shifted down, the ECU 14 performs the engagement control of the forward / reverse switching mechanism 7 shown in FIG. FIG. 4 is a flowchart showing an example of engagement control of the forward / reverse switching mechanism by the ECU.

  First, after performing the hydraulic control of the hydraulic control device 13 shown in FIG. 3 (step S20), the ECU 14 has caused a downshift based on the detection results by the input shaft rotation sensor 59 and the output shaft rotation sensor 64. It is determined whether or not (step S21). When the ECU 14 determines that a downshift has occurred (Yes), the ECU 14 determines whether or not the change amount and change rate of the downshift are within a preset set change amount and a preset change rate (predetermined value). Determination is made (step S22). On the other hand, when the ECU 14 determines that no downshift has occurred (No), the engagement control of the forward / reverse switching mechanism 7 ends. The set change amount and the set change rate can be allowed to be applied to the forward clutch 42 and the reverse brake 43 when the forward clutch 42 and the reverse brake 43 are engaged by the engagement control of the forward / reverse switching mechanism 7. It is a threshold value for determining whether or not there is.

  When the ECU 14 determines that the change amount and the change rate of the downshift are within the preset change amount and the preset change rate (Yes), the ECU 14 releases the engagement of the lockup clutch 23 of the torque converter 6. The hydraulic control circuit 72 is controlled (step S23). On the other hand, if the ECU 14 determines that the change amount and the change rate of the downshift are larger than the preset change amount and the preset change rate (No), the ECU 14 performs steps until the change amount is within the set change amount and the set change rate. Repeat S22. After step S23, the ECU 14 engages the clutch of the forward / reverse switching mechanism 7 (step S24). That is, the ECU 14 controls the engagement of the forward clutch 42 when the vehicle 1 moves forward, and controls the engagement of the reverse brake 43 when the vehicle 1 moves backward. Then, when the ECU 14 engages and controls the forward / reverse switching mechanism 7, a large load is applied when the engine is started, so that the engine torque is changed and controlled so that the engine torque increases (step S25).

  According to the above configuration, the ECU 14 can supply the oil toward the secondary hydraulic chamber 63 of the secondary pulley 51 by operating the accumulator 73 during the idling stop-and-start control. Further, the ECU 14 can maintain the hydraulic pressure of the primary hydraulic chamber 58 of the primary pulley 50 by simultaneously closing the supply-side hydraulic control valve 81a and the discharge-side hydraulic control valve 81b. For this reason, even if a clamping pressure is generated in the secondary pulley 51 and a tension is generated in the belt 52, the primary pulley 50 can secure a clamping pressure against the tension of the belt 52. Therefore, the primary pulley 50 operates to the downshift side. It becomes difficult to do. Therefore, the ECU 14 can suppress an increase in the differential rotation between the input side and the output side of the forward / reverse switching mechanism 7 during S & S control, and reduce the load when the clutch of the forward / reverse switching mechanism 7 is engaged. Can do. Thereby, the wear life of the clutch of the forward / reverse switching mechanism 7 can be extended. Further, the belt-type continuously variable transmission 8 is less likely to change the gear ratio before and after the S & S control, so that it is possible to reduce the uncomfortable feeling of the driver driving the vehicle 1. Further, conventionally, in order to reduce the differential rotation between the input side and the output side of the forward / reverse switching mechanism 7, the shift control is performed so that the gear ratio of the belt-type continuously variable transmission 8 is once shifted up to the high side. However, since it is not necessary to perform this shift control, the responsiveness when the vehicle 1 starts can be secured.

  Further, since the ECU 14 can simultaneously close the supply side hydraulic control valve 81a and the discharge side hydraulic control valve 81b, even if the hydraulic pressure in the primary hydraulic chamber 58 rises due to the tension of the belt 52, the discharge side hydraulic control valve In addition to the outflow of oil from the second oil passage L2 in 81b, the backflow of oil from the first oil passage L1 in the supply side hydraulic control valve 81a can be suppressed.

  Further, when the belt-type continuously variable transmission 8 is downshifted after the hydraulic pressure control during the S & S control, the ECU 14 determines that the torque converter 6 if the change amount and change rate of the downshift are within the set change amount and the set change rate. The lockup clutch 23 can be released and the forward / reverse switching mechanism 7 can be engaged. Thereby, the ECU 14 can control the engagement of the forward / reverse switching mechanism 7 before the differential rotation between the input side and the output side of the forward / reverse switching mechanism 7 becomes large. The load at the time can be further reduced.

  As described above, the vehicle control device according to the present invention is useful for a vehicle including an engine and a belt-type continuously variable transmission, and is particularly suitable for extending the wear life of the clutch of the forward / reverse switching mechanism. Yes.

DESCRIPTION OF SYMBOLS 1 Vehicle 5 Engine 6 Torque converter 7 Forward / reverse switching mechanism 8 Belt type continuously variable transmission 13 Hydraulic controller 14 ECU
DESCRIPTION OF SYMBOLS 23 Lockup clutch 24 Mechanical oil pump 42 Forward clutch 43 Reverse brake 50 Primary pulley 51 Secondary pulley 52 Belt 58 Primary hydraulic chamber 59 Input shaft rotation sensor 63 Secondary hydraulic chamber 64 Output shaft rotation sensor 71 Electric oil pump 72 Hydraulic control circuit 73 Accumulator 81a Supply-side hydraulic control valve 81b Discharge-side hydraulic control valve 82a Supply-side electromagnetic control valve 82b Discharge-side electromagnetic control valve 82c Accumulation release electromagnetic control valve L1 First oil path L2 Second oil path L3 Third oil path

Claims (3)

Engine,
A first pulley to which the power of the engine is input; a second pulley that outputs the power of the engine toward a drive wheel; and a belt that is stretched between the first pulley and the second pulley. A belt-type continuously variable transmission,
A clutch mechanism for connecting the engine and the belt-type continuously variable transmission to transmit the power of the engine to the belt-type continuously variable transmission;
An oil pump capable of supplying oil to the belt-type continuously variable transmission by the power of the engine;
A hydraulic control valve capable of controlling the hydraulic pressure in the first hydraulic chamber of the first pulley;
A vehicle control device capable of controlling a vehicle comprising: a pressure accumulator capable of supplying the oil toward the second hydraulic chamber of the second pulley of the belt-type continuously variable transmission;
While the vehicle is stopped, the engine is stopped, and when the idling stop-and-start control is started to start the engine when the vehicle is started, the pressure accumulator is operated and the hydraulic control valve is closed. A vehicle control device. The hydraulic control valve is
A supply-side hydraulic control valve capable of controlling the hydraulic pressure of the oil supplied toward the first hydraulic chamber of the first pulley;
A discharge side hydraulic control valve capable of controlling the hydraulic pressure of the oil discharged from the first hydraulic chamber of the first pulley,
The vehicle control device according to claim 1, wherein the supply-side hydraulic control valve and the discharge-side hydraulic control valve are simultaneously closed when the idling stop-and-start control is executed. The vehicle is
A torque converter with a lockup mechanism that connects between the engine and the clutch mechanism and transmits the power of the engine to the clutch mechanism;
When the change amount and change rate of the gear ratio of the belt-type continuously variable transmission are within a preset change amount and set change rate, after releasing the lock-up engagement by the lock-up mechanism, the clutch The vehicle control apparatus according to claim 1, wherein clutch engagement by a mechanism is executed.

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