JP2012225466A - Hydraulic control device - Google Patents

Abstract

Provided is a hydraulic control device capable of reducing a load applied to an oil pump when an engine is restarted.
An engine, a torque converter coupled to the engine, a continuously variable transmission coupled to the torque converter, a torque converter and a continuously variable transmission are provided between the torque converter and the continuously variable transmission. In a hydraulic control device for controlling the hydraulic pressure of a vehicle, comprising a forward / reverse switching mechanism capable of releasing the connection of the motor and an oil pump capable of supplying oil to the torque converter by engine power, during deceleration of the vehicle When the engine is stopped and the connection between the torque converter and the continuously variable transmission is released by the forward / reverse switching mechanism (step S2), the oil in the torque converter is confined (step S3 and step S4).
[Selection] Figure 2

Description

  The present invention relates to a hydraulic control device that controls the hydraulic pressure of a vehicle.

  2. Description of the Related Art Conventionally, a continuously variable transmission having a first power transmission path that passes through a torque converter and a second power transmission path that passes through a continuously variable transmission mechanism is known (see, for example, Patent Document 1). In this continuously variable transmission, the flow rate of oil supplied to the continuously variable transmission mechanism is reduced during power transmission through the first power transmission path, while being supplied to the torque converter during power transmission through the second power transmission path. The oil flow rate is reduced.

  Also, clutch means that can be in a first power transmission state in which the engine power is transmitted to the continuously variable transmission via the torque converter and a second power transmission state in which the engine power is transmitted to the continuously variable transmission without passing through the torque converter. Is known (see, for example, Patent Document 2). This power transmission device has an oil pump that is operated by the power of the engine, and the oil pump supplies oil to the torque converter, the continuously variable transmission, and the clutch means. When the vehicle speed of the vehicle in the fuel cut state becomes a predetermined value or less and the engine stops, the power transmission device restricts or prohibits the flow rate of oil supplied from the oil pump to the torque converter, The oil supplied to the clutch means and the continuously variable transmission is prioritized.

JP-A-5-1756 JP 2010-216625 A

  As in the configuration of Patent Document 2, in the vehicle, the engine may be stopped during deceleration of the vehicle. If the engine is stopped while the vehicle is decelerating, the oil pump that is driven by the power of the engine is stopped, so the amount of oil supplied to the oil pump is reduced. At this time, as in Patent Documents 1 and 2, the amount of oil supplied to the torque converter is reduced, but even when the amount of oil supplied is reduced, the oil is discharged from the torque converter, The hydraulic pressure in the torque converter is lowered. In this case, when the engine is restarted, the amount of oil supplied from the oil pump toward the torque converter increases as oil is discharged from the torque converter. For this reason, it is considered that the load of the oil pump increases when the engine is restarted.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a hydraulic control device that can reduce a load applied to an oil pump when the engine is restarted.

  A hydraulic control apparatus according to the present invention is provided between an engine, a torque converter coupled to the engine, a transmission coupled to the torque converter, and the torque converter and the transmission, and the coupling between the torque converter and the transmission. In a hydraulic control device that controls the hydraulic pressure of a vehicle, including a clutch mechanism that can release the engine and an oil pump that can supply oil toward the torque converter by engine power, the engine is stopped during deceleration of the vehicle. When the connection between the torque converter and the transmission is released by the clutch mechanism, the oil in the torque converter is confined.

  Since the hydraulic control device according to the present invention does not require oil supply to the torque converter by opening the clutch mechanism when the engine is stopped, the oil is confined in the torque converter, so that the torque can be reduced when the engine is restarted. The amount of oil supplied to the converter can be reduced, and the load applied to the oil pump can be suppressed.

FIG. 1 is a diagram illustrating a vehicle to which a hydraulic control device according to an embodiment is applied. FIG. 2 is a flowchart showing the operation of the hydraulic control apparatus according to the embodiment.

  Hereinafter, an embodiment of a hydraulic 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 the hydraulic control device according to the embodiment is applied, and FIG. 2 is a flowchart illustrating the operation of the hydraulic control device according to the embodiment. 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. And a continuously variable transmission 8 coupled to the switching mechanism 7, which constitute a part of the power transmission path of the vehicle 1. The vehicle 1 also includes a hydraulic control device 13 that can supply oil to the power transmission path, and an ECU 14 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 via 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 forward / reverse switching mechanism 7 changes the rotation transmitted from the crankshaft 15 of the engine 5 to the rotation direction in which the vehicle 1 moves forward or to the rotation direction in which the vehicle 1 moves backward, and from the engine 5 to the continuously variable transmission 8. The power transmission to is released.

  The continuously variable transmission 8 is, for example, a belt type, and includes a primary shaft 55 serving as an input shaft and a secondary shaft 60 serving as an output shaft. The continuously variable transmission 8 changes the rotational speed of the primary shaft 55 rotated by the power input from the forward / reverse switching mechanism 7 to the desired rotational speed of the secondary shaft 60 according to the driving state of the vehicle 1 and outputs it. To do. The configurations of the torque converter 6 and the forward / reverse switching mechanism 7 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 rotation direction is input to the continuously variable transmission 8, and the primary shaft 55 rotated by the input power rotates the secondary shaft 60 according to a predetermined speed ratio of the continuously variable transmission 8. The speed is changed. The power from the secondary shaft 60 whose rotational speed has been changed by the continuously variable transmission 8 is transmitted to the drive wheels via a reduction gear and a differential device (not shown), and the vehicle 1 travels as the drive wheels rotate. To do.

  Next, the torque converter 6 will be described. The torque converter 6 includes a pump impeller 20, a turbine runner 21, a stator 22, a lockup clutch piston 23, and a facing 27. The torque converter 6 is provided with an oil pump 24 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 can be transmitted to the turbine runner 21 via oil.

  In addition, an oil pump 24 is connected to the pump impeller 20, and the oil pump 24 is operated by transmitting power generated from the engine 5 through the crankshaft 15, the front cover 25, and the pump impeller 20. To do.

  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 30.

  The lockup clutch piston 23 is provided between the turbine runner 21 and the front cover 25 and is connected to the input shaft 38. The lock-up clutch piston 23 includes a hydraulic chamber defined by the pump impeller 20 and the front cover 25, an apply chamber 31 formed on the pump impeller 20 side with the lock-up clutch piston 23 interposed therebetween, and a lock-up clutch piston 23. It is divided into a release chamber 32 formed on the drive plate 26 side. The facing 27 is provided on the drive plate 26 side of the lockup clutch piston 23 and can contact the inside of the front cover 25.

  Oil is supplied from the hydraulic control device 13 to the apply chamber 31 and the release chamber 32. When the hydraulic pressure in the apply chamber 31 becomes higher than the hydraulic pressure in the release chamber 32, the lockup clutch piston 23 performs a lockup fastening operation by bringing the facing 27 into contact with the front cover 25. For this reason, when the lockup clutch piston 23 performs the lockup fastening operation, the pump impeller 20 and the turbine runner 21 are fastened, and the power of the crankshaft 15 can be directly transmitted to the turbine runner 21. On the other hand, when the hydraulic pressure in the apply chamber 31 becomes lower than the hydraulic pressure in the release chamber 32, the lockup clutch piston 23 performs a lockup fastening release operation when the facing 27 is separated from the front cover 25. For this reason, when the lockup clutch piston 23 performs the lockup engagement release operation, the engagement between the pump impeller 20 and the turbine runner 21 is released, and the power of the crankshaft 15 is transmitted to the turbine runner 21 via oil.

  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. Further, 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. Further, the forward / reverse switching mechanism 7 disengages the forward clutch 42 and the reverse brake 43 when releasing the power transmission from the engine 5 to the continuously variable transmission 8.

  Next, the hydraulic control device 13 will be described. The hydraulic control device 13 includes the oil pump 24 and a hydraulic control circuit 72 to which oil is supplied from the oil pump 24. An oil cooler 50 that cools the engine 5 is connected to the hydraulic control circuit 72, and the hydraulic control device 13 can supply oil toward the oil cooler 50. The hydraulic pressure control circuit 72 is connected to the ECU 14, and the hydraulic pressure control device 13 functions when the hydraulic pressure control circuit 72 is controlled by the ECU 14.

  The oil pump 24 sucks and pressurizes oil stored in an oil pan (not shown), and supplies the oil toward the hydraulic control circuit 72. The oil pump 24 can be operated by the power of the engine 5 as described above. For this reason, the oil pump 24 increases the amount of discharged oil when the rotational speed of the engine 5 increases, while the amount of discharged oil decreases when the rotational speed of the engine 5 decreases.

  The hydraulic control circuit 72 has a plurality of hydraulic control valves including a spool valve element and an electromagnetic solenoid, and a plurality of oil passages. The ECU 14 can control the oil pressure in each oil passage by appropriately controlling the oil pressure control valve. Examples of the hydraulic control valve include a first hydraulic control valve 74 and a second hydraulic control valve 75. Further, as the oil path, for example, a first oil path L1 from the hydraulic control circuit 72 to the forward clutch 42, a second oil path L2 from the hydraulic control circuit 72 to the reverse brake 43, and an apply chamber from the hydraulic control circuit 72 are provided. A third oil passage L3 leading to 31, a fourth oil passage L4 leading from the hydraulic control circuit 72 to the release chamber 32, a fifth oil passage L5 leading from the hydraulic control circuit 72 to the oil cooler 50, and a first hydraulic control valve 74. And a sixth oil passage L6 extending from the second hydraulic control valve 75 to the second hydraulic control valve 75. Although not shown, there is an oil path from the hydraulic control circuit 72 to the continuously variable transmission 8 in addition to the hydraulic control valves 74 and 75 and the oil paths L1 to L6.

  The first hydraulic control valve 74 supplies the oil supplied from the oil pump 24 toward the second hydraulic control valve 75 via the sixth oil passage L6. The second hydraulic control valve 75 supplies the oil supplied from the first hydraulic control valve 74 toward the third oil path L3, the fourth oil path L4, and the fifth oil path L5. At this time, the third oil passage L3, the fourth oil passage L4, and the fifth oil passage L5 communicate with each other.

  Accordingly, when the oil pump 24 is activated and oil is supplied from the oil pump 24 to the hydraulic control circuit 72, the hydraulic control circuit 72 is controlled by the ECU 14, thereby causing the torque converter 6, the forward / reverse switching mechanism 7 and the non-return mechanism 7 to operate. The step transmission 8 is hydraulically controlled. Accordingly, 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 engagement operation and the engagement release operation of the lockup clutch 23 in the torque converter 6 by controlling the oil pressure of the oil supplied to the lockup clutch 23. Furthermore, the hydraulic control device 13 can control the speed ratio of the continuously variable transmission 8 to a desired speed ratio.

  The ECU 14 controls the vehicle 1, for example, the engine 5, the torque converter 6, the forward / reverse switching mechanism 7, the continuously variable transmission 8, and the like that are part of the power transmission path of the vehicle 1. Specifically, the ECU 14 controls the operation of the engine 5 and controls the gear ratio of the continuously variable transmission 8 based on various input signals and various maps input from sensors attached to various parts of the vehicle 1. Or the forward / reverse switching of the forward / reverse switching mechanism 7 is controlled, or the lock-up of the torque converter 6 is controlled.

  In other words, the ECU 14 is connected to a fuel injection valve, a throttle valve, and a spark plug (not shown) of the engine 5 and is based on an operating state such as an engine speed, a throttle opening, and an accelerator opening detected by sensors in various places. Control these driving. The ECU 14 is connected to a hydraulic control circuit 72 and controls the torque converter 6, the forward / reverse switching mechanism 7 and the continuously variable transmission 8 by performing hydraulic control of the hydraulic control circuit 72 and the like.

  Here, in order to improve the fuel efficiency of the vehicle 1, the ECU 14 stops the engine 5 while the vehicle 1 is decelerating and also performs idling stop-and-start control (hereinafter referred to as S & S control) that starts the engine 5 when the vehicle 1 starts. Is running. Hereinafter, the S & S control by the ECU 14 will be described with reference to FIG. 2, and the control of the hydraulic control circuit 72 during the S & S control by the ECU 14 will be described.

  When the vehicle 1 decelerates and stops, the ECU 14 determines whether or not to execute S & S control (step S1). When the ECU 14 executes the S & S control (step S1: Yes), the ECU 14 stops the engine 5 and releases the forward clutch 42 of the forward / reverse switching mechanism 7 (step S2). Here, the stop of the engine 5 is to stop fuel injection from a fuel injection valve provided in the engine 5. As a result, the forward / reverse switching mechanism 7 is in a state where the engagement of the forward clutch 42 and the reverse brake 43 is released, and releases the power transmission from the engine 5 to the continuously variable transmission 8. In addition, if ECU14 determines with not performing S & S control (step S1: No), it will progress to step S1 again. When the engine 5 is stopped after the fuel injection is stopped, the operation of the oil pump 24 is stopped, whereby the flow rate of the oil supplied toward the hydraulic control circuit 72 is decreased.

  When the power transmission from the engine 5 to the continuously variable transmission 8 is canceled by executing Step S2, the oil supply to the torque converter 6 becomes unnecessary. For this reason, after execution of step S2, the ECU 14 controls the hydraulic control circuit 72 to execute control for confining oil in the torque converter 6. Specifically, after the execution of step S2, the ECU 14 controls the hydraulic control circuit 72 and closes the sixth oil passage L6, whereby the oil from the first hydraulic control valve 74 to the second hydraulic control valve 75 is controlled. Supply is stopped (step S3). After executing step S3, the ECU 14 controls the hydraulic control circuit 72 to close the fifth oil passage L5, thereby stopping the supply of oil from the second hydraulic control valve 75 to the fifth oil passage L5 ( Step S4). Thereby, since ECU14 can stop supply and discharge | emission of the oil in the 3rd oil path L3 and the 4th oil path L4, it can confine the oil in the torque converter 6. FIG.

  Thereafter, when the vehicle 1 tries to start, the ECU 14 restarts the engine 5 and engages the forward clutch 42 of the forward / reverse switching mechanism 7. As a result, the forward / reverse switching mechanism 7 is in a state where the forward clutch 42 is engaged and the reverse brake 43 is disengaged, and power is transmitted so that the engine 5 moves forward to the continuously variable transmission 8. Is called. Further, when the engine 5 is restarted, the oil pump 24 is operated, and thereby the flow rate of the oil supplied toward the hydraulic pressure control circuit 72 is increased. For this reason, the ECU 14 controls the hydraulic control circuit 72 to open the closed fifth oil passage L5 and sixth oil passage L6.

  As described above, according to the present embodiment, when the engine 5 is stopped during the deceleration of the vehicle 1 and the flow rate of the oil supplied from the oil pump 24 decreases, the hydraulic control device 13 By closing L5 and the sixth oil passage L6, the oil in the torque converter 6 can be confined. For this reason, the hydraulic control device 13 can suppress the amount of oil discharged from the torque converter 6 when the engine 5 is stopped, and the amount of oil supplied to the torque converter 6 when the engine 5 is restarted. Can be reduced. Thereby, the hydraulic control device 13 can reduce the load applied to the oil pump 24 when the engine 5 is restarted.

DESCRIPTION OF SYMBOLS 1 Vehicle 5 Engine 6 Torque converter 7 Forward / reverse switching mechanism 8 Continuously variable transmission 13 Hydraulic control device 14 ECU
DESCRIPTION OF SYMBOLS 15 Crankshaft 20 Pump impeller 21 Turbine runner 22 Stator 23 Lock-up clutch piston 24 Oil pump 25 Front cover 26 Drive plate 27 Facing 31 Apply chamber 32 Release chamber 38 Input shaft 41 Planetary gear mechanism 42 Forward clutch 43 Reverse brake 44 Sun gear 45 Pinion 46 ring gear 47 switching carrier 50 oil cooler 55 primary shaft 60 secondary shaft 72 hydraulic control circuit 74 first hydraulic control valve 75 second hydraulic control valve L1 first oil path L2 second oil path L3 third oil path L4 fourth oil Road L5 5th oil path L6 6th oil path

Claims (1)

Engine,
A torque converter coupled to the engine;
A transmission coupled to the torque converter;
A clutch mechanism provided between the torque converter and the transmission, and capable of releasing the connection between the torque converter and the transmission;
In the hydraulic control device for controlling the hydraulic pressure of the vehicle including an oil pump capable of supplying oil toward the torque converter by the power of the engine,
An oil pressure control device for confining oil in the torque converter when the engine is stopped during deceleration of the vehicle and the connection between the torque converter and the transmission is released by the clutch mechanism.

Images