JP2009144873A - Vehicle driving device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle driving device having a hydraulic circuit capable of efficiently supplying hydraulic pressure in a short time to a hydraulic servo from an accumulator, while necessarily minimizing capacity of the accumulator. <P>SOLUTION: The hydraulic circuit 50 is provided in a continuously variable transmission 30. A first oil passage 63a and a second oil passage 63b branching off in a branch part and merging in a merging part, are arranged in an oil passage 6 for connecting an oil pump 51 and a forward clutch C1, and a three-way check valve 75 is arranged in the merging part. Out of the three-way check valve 75, one port is connected to the forward clutch C1, and residual two ports are respectively connected to the first oil passage 63a and the second oil passage 63b. One-way valve 71 for making oil flow only in the direction to the merging part from the branch part, the accumulator 56 and a solenoid switching valve 55, are arranged in this order from the branch part in the second oil passage 63b. When starting driving of the oil pump 51, the solenoid switching valve 55 is turned on, and the second oil passage 63b is communicated. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicle drive device that can quickly supply a hydraulic pressure to a hydraulic servo when the engine is restarted, and can quickly engage, for example, a friction engagement element that enables vehicle start.

  Conventionally, in order to save fuel, reduce exhaust emissions, reduce noise, etc., a vehicle equipped with a function (idling stop function) that automatically stops the engine when a predetermined condition is satisfied during driving has been put into practical use. Has been. In such a vehicle, for example, the engine is stopped when all of the conditions such as vehicle speed zero, accelerator off, and brake on are satisfied.

  Here, when the engine stops, the oil pump generally connected to the engine also stops. For this reason, for example, the oil supplied to the forward clutch (hydraulic servo) to be engaged during forward travel also escapes from the oil passage, and the forward clutch has been released from its engaged state. turn into.

  Then, when a predetermined restart condition is satisfied, such as when the driver steps on the accelerator pedal, the stopped engine is restarted, and the oil pump is also restarted. At this time, if the forward clutch is not quickly engaged as the engine is restarted, the forward clutch is engaged with the engine blown up, and an engagement shock occurs.

  Therefore, various techniques for preventing such an engagement shock from occurring have been proposed. For example, an accumulator capable of accumulating hydraulic pressure is branched and installed in an oil passage that connects a forward clutch of an automatic transmission and an oil pump that generates hydraulic pressure to supply hydraulic pressure to the forward clutch. (Patent Document 1). When the engine is restarted, the hydraulic pressure stored in the accumulator is supplied to the forward clutch, thereby preventing the occurrence of engagement shock and improving the restartability of the engine.

  Some accumulators are branched and installed in the hydraulic circuit of an automatic transmission, and a check valve is provided on the oil pump side of the accumulator (Patent Documents 2 and 3). Thus, hydraulic pressure is always supplied from the accumulator to the forward clutch when the engine is stopped, so that the forward clutch in the automatic transmission is always kept in the engaged state.

JP 2000-313252 A JP-A-8-14076 JP 2005-226802 A

  However, the technique described in Patent Document 1 has a problem that the hydraulic pressure stored in the accumulator when the engine is restarted cannot be efficiently supplied to the forward clutch (hydraulic servo) in a short time. This is because when the hydraulic pressure stored in the accumulator is supplied to the forward clutch (hydraulic servo), the hydraulic pressure is supplied not only to the forward clutch (hydraulic servo) but also to the primary regulator valve. This is because the hydraulic pressure leaks.

  Further, a second accumulator, a second switching valve, and a branch oil passage are provided in front of the forward clutch (hydraulic servo). For this reason, when the hydraulic pressure stored in the accumulator is supplied to the forward clutch (hydraulic servo), these increase the fluid resistance and lengthen the oil passage. As a result, it takes a long time until the hydraulic pressure is supplied from the accumulator to the forward clutch (hydraulic servo). This is also one of the reasons why the hydraulic pressure stored in the accumulator cannot be efficiently supplied to the forward clutch (hydraulic servo) in a short time.

  On the other hand, as in the techniques described in Patent Documents 2 and 3, when the engine is stopped, the hydraulic pressure is constantly supplied from the accumulator to the forward clutch, and the forward clutch in the automatic transmission is always kept in the engaged state. Since the supply delay does not occur, the problem of the engagement shock can be solved. However, this technique has a problem that it is necessary to increase the capacity of the accumulator. Further, since the outlet (turbine) side of the torque converter is stopped when the engine is started, the engine rotation can only be absorbed by the torque converter oil, and the engine is restarted while stirring the torque converter oil. As a result, a large burden is placed on the starter system, and new problems such as the need for a large starter occur.

  Therefore, the present invention has been made to solve the above-described problems, and is a hydraulic circuit capable of efficiently supplying hydraulic pressure from an accumulator to a hydraulic servo in a short time while minimizing the capacity of the accumulator. It is an object of the present invention to provide a vehicle drive device including the above.

  A vehicle drive device according to the present invention made to solve the above problems includes an oil pump that generates hydraulic pressure, a hydraulic servo that is controlled by hydraulic pressure, an accumulator that stores the hydraulic pressure generated by the oil pump, A switching valve for switching between a shutoff / communication state of an oil passage connected between the accumulator and the hydraulic servo, and the oil pump is stopped and driven as necessary, and is stored in the accumulator at the start of oil pump driving. In the vehicle drive device having the hydraulic circuit for supplying the hydraulic pressure to the hydraulic servo, the oil passage connecting the oil pump and the hydraulic servo is branched at the branch portion and joined at the junction portion. An oil passage and a second oil passage, and a three-way check valve is disposed at the junction, and one of the three-way check valves is Are connected to the hydraulic servo, and the remaining two ports are connected to the first oil passage and the second oil passage, respectively. A one-way valve that allows oil to flow only in the direction to the direction, the accumulator, and the switching valve are arranged in this order from the branch portion, the three-way check valve includes the first oil passage and the The higher hydraulic pressure of the second oil passage is communicated with the hydraulic servo, and the switching valve is in a communication state only for a predetermined time when the oil pump starts to be driven.

  In this vehicle drive device, the switching valve is in a shut-off state except when the oil pump starts to be driven. Therefore, the hydraulic pressure generated by the oil pump is transferred to the hydraulic pressure via the first oil passage and the three-way check valve. Supplied to the servo. Further, the hydraulic pressure generated by the oil pump is stored in the accumulator through the second oil passage. Then, when the oil pump stops, the supply of hydraulic pressure to the hydraulic servo stops. At this time, hydraulic pressure is held in the accumulator.

  When the oil pump is driven from this state, the switching valve is in communication for a predetermined time, and the hydraulic pressure stored in the accumulator is supplied to the hydraulic servo via the second oil passage and the three-way check valve. Is done. The predetermined time may be set until the oil pump is driven and the hydraulic pressure is supplied from the oil pump to the hydraulic servo. At this time, the hydraulic pressure from the accumulator is supplied not only in the direction to the merging portion but also in the direction toward the branching portion via the second oil passage. The latter oil flow is caused by the first one-way valve. Be blocked. That is, the hydraulic pressure from the accumulator is surely prevented from leaking from the branch portion. Thereby, since the hydraulic pressure from the accumulator is supplied only to the hydraulic servo, the hydraulic pressure can be efficiently supplied from the accumulator to the hydraulic servo in a short time.

  Further, in this vehicle drive device, since the hydraulic pressure is not always supplied from the accumulator to the forward clutch (hydraulic servo) when the oil pump is stopped, it is not necessary to increase the capacity of the accumulator, and a large starter There is no need for new problems. That is, the accumulator only needs to have a capacity enough to operate the hydraulic servo until the hydraulic pressure generated by the oil pump at the start of the oil pump is supplied to the hydraulic servo.

  Therefore, according to this vehicle drive device, it is possible to efficiently supply hydraulic pressure from the accumulator to the hydraulic servo in a short time while minimizing the capacity of the accumulator.

  In the vehicle drive device according to the present invention, it is desirable that a throttle valve is provided between the branch portion of the second oil passage and the one-way valve.

With such a configuration, when the oil pressure stored in the accumulator is used when the oil pump is driven again after being stopped, the hydraulic servo is passed from the accumulator via the second oil passage and the three-way check valve. The hydraulic pressure can be supplied promptly (at high speed).
After that, when the oil pump is driven and the hydraulic pressure is supplied by the oil pump, the hydraulic pressure is also supplied to the accumulator, but since the throttle valve is provided in the second oil passage, the accumulator slowly ( The oil pressure is accumulated (at low speed). For this reason, most of the hydraulic pressure generated by the oil pump is supplied to the hydraulic servo via the first oil passage and the three-way check valve. Therefore, immediately after the oil pressure stored in the accumulator is supplied to the hydraulic servo at the start of driving the oil pump, the oil pressure generated by the oil pump becomes the accumulated pressure of the accumulator when the oil pressure stored in the accumulator is reduced. Not often used. For this reason, the hydraulic pressure generated by the oil pump after the start of the operation of the oil pump can be supplied promptly (at high speed) to the hydraulic servo. Thereby, the capacity required for the accumulator can be further reduced.

  In the vehicle drive device according to the present invention, the switching valve includes a drain that discharges oil accumulated between the switching valve and the merging portion to the outside of the circuit when the switching valve is shut off. It is desirable.

  With such a configuration, it is possible to release the residual pressure between the switching valve and the merging portion in the second oil passage. Thereby, in the three-way check valve, a differential pressure between the first oil passage and the second oil passage can be secured (the hydraulic pressure of the first oil passage is increased). As a result, the hydraulic pressure generated by the oil pump after the start of the operation of the oil pump can be reliably supplied to the hydraulic servo via the first oil passage and the three-way check valve. Accordingly, after the hydraulic pressure is supplied from the accumulator to the hydraulic servo, the hydraulic pressure generated by the oil pump can be supplied to the hydraulic servo quickly (at high speed).

  When the vehicle drive device according to the present invention is a continuously variable transmission including a primary pulley and a secondary pulley, the hydraulic servo is a forward friction engagement element, and includes a line pressure regulator valve and a clutch. A second one-way valve that allows oil to flow only in the direction of the pulley from the line pressure regulator valve may be provided in the oil passage that connects the pulley to the oil passage that connects the pressure control valve.

  By adopting such a configuration, when the oil pump is stopped, the second one-way valve prevents oil leakage to the hydraulic control valve side in a pulley with a relatively small amount of oil leakage. Can do. Thereby, the fall of the hydraulic pressure in a pulley can be prevented. When the oil pump is stopped, the hydraulic pressure stored in the accumulator at the start of driving the oil pump can be quickly supplied to the forward friction engagement element having a large amount of oil leakage. For these reasons, it is possible to appropriately supply hydraulic pressure to the forward friction engagement element and the pulley at the start of driving the oil pump. As a result, it is possible to reliably prevent the occurrence of the engagement shock of the forward friction engagement element and the occurrence of slipping of the belt with respect to the pulley.

Here, the second one-way valve is preferably provided in an oil passage connecting the line pressure regulator valve and the secondary pulley.
At the start of driving the oil pump, it is in a state that almost no hydraulic pressure is applied to the primary pulley, and the secondary pulley needs to be hydraulically applied. For this reason, by providing a one-way valve on the secondary pulley side and suppressing oil pressure from being removed from the secondary pulley, it is possible to reliably prevent the belt from slipping.

  According to the vehicle drive device of the present invention, as described above, it is possible to efficiently supply hydraulic pressure from the accumulator to the hydraulic servo in a short time while minimizing the capacity of the accumulator.

  BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a most preferred embodiment embodying a vehicle drive device of the present invention will be described in detail with reference to the drawings.

(First embodiment)
First, the first embodiment will be described. In the first embodiment, the present invention is applied to a vehicle drive system including a continuously variable transmission (CVT). A vehicle drive system according to the first embodiment will be described with reference to FIG. FIG. 1 is a configuration diagram showing a schematic configuration of the vehicle drive system according to the first embodiment.

As shown in FIG. 1, the drive system according to the first embodiment includes an engine 10, a continuously variable transmission 30, a control unit 40 that comprehensively controls the system, an engine 10, and a continuously variable transmission. 30 and various sensors for detecting the state of the vehicle and the like.
The engine 10 is provided with an injector 11, a starter 12, and an igniter 13. A continuously variable transmission 30 is connected to the output shaft of the engine 10.

  An intake manifold 15 and an exhaust manifold 16 are connected to each cylinder of the engine 10. The intake manifold 15 is provided with a throttle valve 17 linked with an accelerator pedal. The throttle valve 17 is provided with a throttle position sensor 17a for detecting the opening degree and an idle switch 17b for detecting a fully closed state. The injector 11 is connected to the control unit 40 via a fuel relay 21, the starter 12 is connected via a starter relay 22, and the igniter 13 is connected via an ignition relay 23.

  The continuously variable transmission 30 is a known belt-type continuously variable transmission. The continuously variable transmission 30 includes an input shaft to which the output of the engine 10 is input via a torque converter, a forward / reverse switching clutch, and the like (not shown), and a primary pulley 31 described later is provided on the input shaft. The primary pulley 31 is composed of a fixed sheave and a movable sheave that are coaxially and integrally rotatable with the input shaft. The movable sheave is displaceable in the axial direction of the input shaft, whereas the fixed sheave is fixed to the input shaft. The opposing surfaces of the fixed sheave and the movable sheave are conical surfaces, and a V-belt wound around the primary pulley 31 is sandwiched between them.

  The continuously variable transmission 30 includes an output shaft disposed in parallel with the input shaft, and a secondary pulley 32 described later is provided on the output shaft. The secondary pulley 32 also has the same configuration as the primary pulley 31 and is configured to sandwich a V-belt that is wound around the secondary pulley 32.

  Thus, in the continuously variable transmission 30, the V belt is wound around the primary pulley 31 and the secondary pulley 32, and power is transmitted from the input shaft to the output shaft via the V belt. Then, by holding or changing the position of the movable sheave with respect to the fixed sheave in each pulley by the hydraulic pressure controlled by the hydraulic circuit 50 described later, the winding radius of the V belt on the primary pulley 31 and the secondary of the V belt The rotation speed ratio, that is, the reduction ratio between the input shaft and the output shaft is maintained or changed by maintaining or changing the winding radius around the pulley 32.

  Further, the continuously variable transmission 30 includes a shift position switch 35 that detects a shift position (range) set by a driver's operation, and the rotational speed of the output shaft of the continuously variable transmission 30 connected to the propulsion shaft. A vehicle speed sensor 36 for detecting the vehicle speed is provided. Further, the continuously variable transmission 30 is provided with an oil temperature sensor 37 that detects the temperature of oil in the transmission.

  The control unit 40 includes a CPU that controls various devices, a ROM in which various numerical values and programs are written in advance, and a RAM in which numerical values and flags of calculation processes are written in a predetermined area. Note that an engine stop process and an engine restart process program, which will be described later, are written in advance in a ROM in the control unit 40.

  The control unit 40 includes an ignition primary coil 13a of the igniter 13, a crank position sensor 14, a throttle position sensor 17a, an idle switch 17b, an ignition switch 18, a shift position switch 35, a vehicle speed sensor 36, a CVT oil temperature sensor 37, and a G sensor. 19a, a water temperature sensor 19b, a battery voltage sensor 19c, a brake pedal switch 19d, a brake master cylinder pressure sensor 19e, an intake air temperature sensor 19f, an intake air amount sensor 19g, and the like are connected. The control unit 40 is connected to an electromagnetic switching valve 55 provided in the continuously variable transmission 30 as will be described later. The control unit 40 executes various calculations based on signals from various switches and sensors, and outputs an ignition cut and ignition signal, a fuel cut and fuel injection signal, a starter drive signal, a drive signal for the electromagnetic switching valve 55, and the like. It is supposed to be.

  Here, the hydraulic circuit 50 provided in the continuously variable transmission 30 will be described with reference to FIG. FIG. 2 is a diagram illustrating a hydraulic circuit provided in the continuously variable transmission. As shown in FIG. 2, the hydraulic circuit 50 includes an oil pump 51, a line pressure regulator valve 52, a clutch pressure control valve 53, a manual valve 54, an electromagnetic switching valve 55, an accumulator 56, and a shift control valve. 57 and a secondary sheave pressure control valve 58 are provided. Such a hydraulic circuit 50 is connected to the forward clutch C 1, the reverse brake B 1, and the primary pulley 31 and the secondary pulley 32.

  The oil pump 51 serves as a hydraulic pressure source for the entire continuously variable transmission 30 and generates hydraulic pressure by the driving force of the engine 10. The line pressure regulator valve 52 controls the hydraulic pressure generated by the oil pump 51 to a predetermined pressure in order to control the pulley positions of the primary pulley 31 and the secondary pulley 32. The clutch pressure control valve 53 controls a predetermined pressure in order to operate the forward clutch C1 and the reverse brake B1 (hydraulic servo). The manual valve 54 switches the oil passage in conjunction with the driver's shift position operation. The accumulator 56 temporarily stores the hydraulic pressure generated by the oil pump 51 and regulated by the clutch pressure control valve 53.

  In the hydraulic circuit 50, an oil pump 51 and a line pressure regulator valve 52 are connected by an oil passage 60. The line pressure regulator valve 52 and the clutch pressure control valve 53 are connected by an oil passage 61. Here, the oil passage 61 is branched into oil passages 67 and 68, and the primary pulley 31 and the secondary pulley 32 are connected to the oil passages 67 and 68, respectively. More specifically, the oil passage 67 is connected to the primary pulley 31 via the shift control valve 57, and the oil passage 68 is connected to the secondary pulley 32 via the one-way valve 72 and the secondary sheave pressure control valve 58. Has been.

  An oil passage 63 is connected to the clutch pressure control valve 53. A manual valve 54 is provided in the middle of the oil passage 63. The manual valve 54 and the forward clutch C1 are connected by oil passages 63 and 65, and the manual valve 54 and the reverse brake B1 are connected by an oil passage 66. Thereby, when the manual valve 54 is set to the D position (range), the oil passage 63 is communicated, and the oil passage 66 and the drain EX1 are connected. Further, when the manual valve 54 is set to the R position, the clutch pressure control valve 53 side of the oil passage 63 and the oil passage 66 communicate with each other, and a branch portion side of the oil passage 63 described later and the drain EX1 are connected to each other. Connected. Further, when the manual valve 54 is set to the N, P position, the oil passage 63 is blocked, and the branch side of the oil passage 63 and the oil passage 66 and the drain EX1 are connected. . Thus, when the manual valve 54 is in a position where hydraulic pressure is not required for the forward clutch C1 (other than the D position), the hydraulic pressure acting on the forward clutch C1 is released from the drain EX1, and the hydraulic pressure is applied to the reverse brake B1. At an unnecessary position (other than the R position), the hydraulic pressure acting on the reverse brake B1 is released from the drain EX1.

  Here, the oil passage 63 branches into a first oil passage 63a and a second oil passage 63b at a branch point, and is connected to the oil passage 65 via a three-way check valve 75 at the junction. That is, one of the three ports of the three-way check valve 75 is connected to the oil passage 65, and the first two oil passages 63a and the second oil passage 63b are connected to the remaining two ports. The three-way check valve 75 communicates the oil passage 65 with the higher one of the first oil passage 63a and the second oil passage 63b. Specifically, when the oil pressure of the first oil passage 63a is higher than the oil pressure of the second oil passage 63b, the oil passage 65 and the first oil passage 63a are in communication with each other by the three-way check valve 75. The oil passage 65 and the second oil passage 63b are cut off. On the contrary, when the oil pressure of the first oil passage 63a is lower than the oil pressure of the second oil passage 63b, the oil passage 65 and the first oil passage 63a are blocked by the three-way check valve 75. The oil passage 65 and the second oil passage 63b are in communication with each other.

  The second oil passage 63b is provided with an orifice 74, a one-way valve 71, an accumulator 56, and an electromagnetic switching valve 55 in order from the branching portion with the first oil passage 63a. The one-way valve 71 is configured to allow oil to flow only in the direction from the branch portion between the first oil passage 63a and the second oil passage 63b to the joining portion. Thereby, when the hydraulic pressure is stored in the accumulator 56, the oil passes through the oil passage 63b, and when supplying the hydraulic pressure stored from the accumulator 56, the oil does not leak from the second oil passage 63b to the oil passage 63. It has become.

  The electromagnetic switching valve 55 is controlled to be turned on / off by the control unit 40, and is turned on only when the oil pump 51 is started to drive. Otherwise, the electromagnetic switching valve 55 is turned off. That is, the second oil passage 63b is communicated and blocked by turning on and off the electromagnetic switching valve 55. Further, the electromagnetic switching valve 55 is provided with a drain EX2 for discharging oil out of the circuit. The drain EX2 is connected to the second oil passage 63b on the three-way check valve 75 side when the electromagnetic switching valve 55 is in the off state, that is, the second oil passage 63b is shut off. . Thereby, the residual pressure between the electromagnetic switching valve 55 and the three-way check valve 75 can be released in a state where the second oil passage 63b is blocked.

  Then, an effect | action of a vehicle drive system provided with the above structures is demonstrated. In the vehicle drive system according to the present embodiment, the oil pump 51 is driven by the driving force of the engine 10 when the vehicle is traveling, and the hydraulic pressure is supplied to the hydraulic circuit 50. In the continuously variable transmission 30, the positions of the movable sheaves of the primary pulley 31 and the secondary pulley 32 with respect to the fixed sheave are held or changed by the hydraulic pressure controlled by the shift control valve 57 and the secondary sheave pressure control valve 58. Thus, the winding radius of the V belt on the primary pulley 31 and the winding radius of the V belt on the secondary pulley 32 are maintained or changed, and the reduction ratio is maintained or changed (shifted). At this time, the hydraulic pressure generated by the oil pump 51 is supplied to the accumulator 56 through the oil passages 60, 61, 63 and 63 b in addition to the continuously variable transmission 30.

  Here, in the vehicle drive system according to the present embodiment, engine 10 is temporarily stopped by control unit 40 when a predetermined condition is satisfied. This engine stop process will be described with reference to FIG. FIG. 3 is a flowchart showing the contents of the engine stop process by the control unit.

  First, the controller 40 determines whether or not the vehicle speed is zero (step 1). Specifically, based on the vehicle speed signal from the vehicle speed sensor 36, the CPU of the control unit 40 determines whether or not the vehicle speed is zero. At this time, when the control unit 40 determines that the vehicle speed is zero (S1: YES), it is subsequently determined whether or not the engine speed is equal to or lower than a predetermined speed (step 2). Specifically, based on the engine speed signal from the crank position sensor 14 input to the control unit 40, the CPU of the control unit 40 determines whether the engine speed is equal to or lower than a predetermined speed. As the predetermined rotational speed in step 2, for example, a rotational speed slightly higher than the idle rotational speed may be set. On the other hand, when the control unit 40 determines that the vehicle speed is not zero (S1: NO), the processing routine ends without the engine 10 being stopped.

  In the process of step 2, when it is determined by the control unit 40 that the engine speed is equal to or lower than the predetermined speed (S2: YES), it is subsequently determined whether or not the accelerator opening is zero. (Step 3). On the other hand, when the control unit 40 determines that the engine speed is not equal to or lower than the predetermined speed (S2: NO), the processing routine ends without stopping the engine 10.

  In step 3, specifically, based on the accelerator opening signal from the throttle position sensor 17a, the CPU of the control unit 40 determines whether or not the accelerator opening is zero. In addition, you may make it add the output signal from the idle switch 17b to judgment whether an accelerator opening is zero. In the process of step 3, when the control unit 40 determines that the accelerator opening is zero (S3: YES), it is subsequently determined whether or not the brake switch is turned on (step 4). ). On the other hand, when it is determined by the control unit 40 that the accelerator opening is not zero (S3: NO), the processing routine ends without stopping the engine 10.

  Specifically, in step 4, based on the output signal from the brake pedal switch 19d, the CPU of the control unit 40 determines whether or not the brake pedal switch is turned on. In order to more accurately determine whether or not the brake pedal switch is turned on, that is, whether or not the vehicle brake device is operating, the detection signal from the brake master cylinder pressure sensor 19e should also be considered. It may be. In this case, for example, it is determined that the brake switch is ON only when the brake pedal switch is ON and the pressure detected by the brake master cylinder pressure sensor 19e is equal to or higher than a predetermined value. That's fine.

  If it is determined in the process of step 4 that the brake switch is turned on by the control unit 40 (S4: YES), it is subsequently determined whether other engine stop conditions are satisfied. (Step 5). On the other hand, when the control unit 40 determines that the brake switch is not turned on (S4: NO), the processing routine ends without stopping the engine 10.

  Here, as other engine stop conditions in the process of step 5, for example, climbing / inclination determination based on an output signal from the G sensor 19a (condition is established when the inclination angle is a predetermined value or less), and from the water temperature sensor 19b From the engine water temperature determination based on the output signal (condition is satisfied when the water temperature is within a predetermined range), battery voltage determination based on the output signal of the battery voltage sensor 19c (condition is satisfied when the battery voltage is greater than or equal to a predetermined value), CVT oil temperature determination based on the output signal (condition is satisfied when the CVT oil temperature is within a predetermined range), elapsed time since the previous engine start (condition is satisfied when the predetermined time is exceeded), vehicle speed history (when the value is above a predetermined value) For example).

  If all the other engine stop conditions are satisfied in the process of step 5, that is, if all of the processes in steps 1 to 5 are affirmative (S5: YES), the engine 10 is stopped (step 5). 6). Specifically, a fuel cut signal and an ignition cut signal constituting an engine stop signal are output from the control unit 40 to the fuel relay 21 and the ignition relay 23, respectively. As a result, the high voltage is not supplied from the igniter 13 to the spark plug, and the fuel is not injected from the injector 11, and the engine 10 is stopped. On the other hand, when all the other engine stop conditions are not satisfied (S5: NO), the processing routine ends without stopping the engine 10.

  Here, since the oil pump 51 is also stopped when the engine 10 is stopped, the hydraulic pressure is not supplied to the hydraulic circuit 50. At this time, the electromagnetic switching valve 55 is OFF and the second oil passage 63b is shut off, and the one-way valve 71 prevents hydraulic pressure from leaking from the accumulator 56 to the first oil passage 63a. Is done. For this reason, in the accumulator 56, the state which stored the hydraulic pressure is maintained. When the engine 10 is temporarily stopped as described above, the control unit 40 executes a restart processing routine of the engine 10. The restart process after the engine is temporarily stopped will be described with reference to FIG. FIG. 4 is a flowchart showing the contents of the engine restart process by the control unit.

  First, the control unit 40 determines whether or not the engine 10 is stopped (step 10). At this time, when the control unit 40 determines that the engine 10 is stopped (S10: YES), it is determined whether or not the position of the manual valve 54 is set to the D range (step 11). . This determination is made based on an output signal from the shift position switch 35. If the control unit 40 determines that the engine 10 is not stopped (S10: NO), it is not necessary to restart the engine 10, and the processing routine ends.

  If the control unit 40 determines in the process of step 11 that the position of the manual valve 54 is set to the D range (S11: YES), it is determined whether or not an engine restart condition is satisfied. (Step 12). On the other hand, when the control unit 40 determines that the position of the manual valve 54 is not set to the D range (S11: NO), this processing routine ends. Here, examples of the engine restart condition in the process of step 11 include that the vehicle speed is zero, that the brake switch is OFF, and that the accelerator opening is not zero.

  If the engine restart condition is satisfied in the process of step 12 (S12: YES), the engine 10 is restarted after the electromagnetic switching valve 55 is turned on (step 13) (step 13). 14). Specifically, a fuel injection signal, an ignition signal, and a starter drive signal that constitute an engine restart signal are output from the control unit 40 to the fuel relay 21, the ignition relay 23, and the starter relay 22, respectively. Thereby, the starter 12 is driven, a high voltage is supplied from the igniter 13 to the spark plug, fuel is injected from the injector 11, and the engine 10 is restarted. On the other hand, when the engine restart condition is not satisfied (S12: NO), this processing routine ends.

  Thus, when the engine 10 is restarted, the electromagnetic on-off valve 55 is turned on immediately before the engine is started, so that the second oil passage 63b is in a communicating state. That is, at the start of driving of the oil pump 51, the electromagnetic on-off valve 55 is turned on and the second oil passage 63b is brought into communication. For this reason, the accumulator 56 and the three-way check valve 75 communicate with each other. Thereby, the hydraulic pressure stored in the accumulator 56 is supplied to the three-way check valve 75 via the oil passage 63b. At this time, since the hydraulic pressure in the second oil passage 63b is higher than the hydraulic pressure in the first oil passage 63a, the second oil passage 63b and the oil passage 65 are communicated by the three-way check valve 75.

  Thereby, the hydraulic pressure stored in the accumulator 56 is supplied to the forward clutch C1 via the second oil passage 63b, the three-way check valve 75, and the oil passage 65. Here, the hydraulic pressure supplied from the accumulator 56 is also supplied to the branching point side with the first oil passage 63a via the second oil passage 63b. However, the one-way valve 71 is provided in the second oil passage 63b between the accumulator 56 and the branch point of the first oil passage 63a. For this reason, the hydraulic pressure supplied from the accumulator 56 does not escape to the oil passage 63. Thereby, since the hydraulic pressure from the accumulator 56 is supplied only to the forward clutch C1, the hydraulic pressure can be efficiently supplied from the accumulator 56 to the forward clutch C1 in a short time.

  Further, since the hydraulic pressure is not always supplied from the accumulator 56 to the forward clutch C1 when the oil pump 51 is stopped, the capacity of the accumulator 56 does not need to be increased and a large starter is not required. That is, the accumulator 56 has a capacity that can supply the hydraulic pressure to the forward clutch C1 only until the hydraulic pressure generated by the oil pump 51 at the start of the oil pump 51 is supplied to the forward clutch C1. It only has to be prepared.

  Therefore, according to the vehicle drive system according to the present embodiment, the hydraulic pressure can be efficiently supplied from the accumulator 56 to the forward clutch C1 in a short time when the engine is restarted while minimizing the capacity of the accumulator 56. it can.

  When the engine 10 is started, the electromagnetic switching valve 55 is turned off and the second oil passage 63b is shut off (step 15). At this time, the oil pump 51 is driven, and hydraulic pressure is supplied from the oil pump 51 to the first oil passage 63a and the second oil passage 63b via the oil passages 60, 61, 63. Here, an orifice 74 is provided in the second oil passage 63 b between the branch point with the first oil passage 63 a and the one-way valve 71. When the oil pump 51 is driven, the hydraulic pressure generated by the oil pump 51 is supplied to the accumulator 56 through the second oil passage 63 b provided with the orifice 74. For this reason, the accumulator 56 accumulates the hydraulic pressure slowly (at low speed).

  Thereby, at the start of driving of the oil pump 51 when the engine 10 is restarted, immediately after the hydraulic pressure stored in the accumulator 56 is supplied to the forward clutch C1, the hydraulic pressure stored in the accumulator 56 is reduced. The hydraulic pressure generated by the oil pump 51 is not often used for accumulating the accumulator 56. At this time, since the electromagnetic switching valve 55 is OFF, the port of the three-way check valve 75 connected to the second oil passage 63b communicates with the drain EX2. For this reason, the residual pressure between the electromagnetic switching valve 55 and the three-way check valve 75 in the second oil passage 63b can be released, and the hydraulic pressure of the first oil passage 63a is higher than the hydraulic pressure of the second oil passage 63b. Can be high. As a result, in the three-way check valve 75, the first oil passage 63a and the oil passage 65 can be reliably communicated with each other. For these reasons, the hydraulic pressure generated by the oil pump 51 at the start of driving of the oil pump 51 can be supplied promptly (at high speed) to the forward clutch C1 via the first oil passage 63a. For this reason, the capacity required for the accumulator 56 can be further reduced.

  The oil passage 68 is provided with a one-way valve 72 that allows oil to flow only from the line pressure regulator valve 52 to the secondary pulley 32 on the upstream side of the secondary sheave pressure control valve 58. Thereby, when the oil pump 51 is stopped, oil leakage from the secondary pulley 32 to the line pressure regulator valve 52 can be prevented. Accordingly, a decrease in hydraulic pressure in the secondary pulley 32 can be prevented.

  Note that oil leakage from the primary pulley 31 to the line pressure regulator valve 52 may occur while the oil pump 51 is stopped. However, in a state where the engine 10 is stopped and the oil pump 51 is stopped, almost no hydraulic pressure is required to act on the primary pulley 31, so long as the hydraulic pressure is applied only to the secondary pulley 32. good. For this reason, oil leakage from the primary pulley 31 hardly occurs. Even if an oil leak from the primary pulley 31 occurs, the oil leak does not cause a slip of the V-belt when the oil pump 51 starts to be driven.

  As described above, when the oil pump 51 is stopped, the oil pressure from the secondary pulley 32 is suppressed by the one-way valve 72. For this reason, when the engine 10 is restarted, an appropriate hydraulic pressure is applied to the secondary pulley 32, so that slippage of the V belt in the continuously variable transmission 30 is reliably prevented.

  As described above in detail, according to the drive system according to the first embodiment, the first oil passage 63a connected to the oil passage 65 connected to the forward clutch C1 via the three-way check valve 75. And a second oil passage 63b. The second oil passage 63b includes an orifice 74, a one-way valve 71, an accumulator 56, an electromagnetic switching valve in this order from the branching side of the oil passage 63 and the first oil passage 63a and the second oil passage 63b. 55 is arranged. Then, the electromagnetic switching valve 55 is turned on by the control unit 40 for a predetermined time when the oil pump 51 starts to be driven.

  For this reason, except when the drive of the oil pump 51 is started, the electromagnetic switching valve 55 is in an OFF (shut off) state. Is supplied to the forward clutch C1. Further, the hydraulic pressure generated by the oil pump 51 is stored in the accumulator 56 via the second oil passage 63b. When the oil pump 51 is stopped, the supply of hydraulic pressure to the forward clutch C1 is stopped. At this time, hydraulic pressure is held in the accumulator 56.

  Thereafter, when the oil pump 51 is driven, the electromagnetic switching valve 55 is turned on (communication), and the hydraulic pressure stored in the accumulator 56 is passed through the second oil passage 63b and the three-way check valve 75. It is supplied to the forward clutch C1. At this time, the hydraulic pressure from the accumulator 56 is supplied not only in the direction to the merging portion but also in the direction toward the branching portion via the second oil passage 63b, but the latter oil flow is caused by the one-way valve 71. Be blocked. That is, the hydraulic pressure from the accumulator 56 is surely prevented from leaking from the branch portion. Further, since the hydraulic pressure is not always supplied from the accumulator 56 to the forward clutch C1 when the oil pump 51 is stopped, the capacity of the accumulator 56 can be reduced. Therefore, according to the vehicle drive system according to the first embodiment, the hydraulic pressure can be efficiently supplied from the accumulator 56 to the forward clutch C1 in a short time while the capacity of the accumulator 56 is minimized.

(Second Embodiment)
Next, a second embodiment will be described. The basic configuration of the second embodiment is substantially the same as that of the first embodiment, but the configuration of the hydraulic circuit provided in the continuously variable transmission is different. For this reason, in the following, the same reference numerals are given to the same components as those in the first embodiment, and the description thereof is omitted as appropriate. The hydraulic circuit will be described with reference to FIG. FIG. 5 is a diagram illustrating a hydraulic circuit in the vehicle drive system according to the second embodiment.

  As shown in FIG. 5, in the hydraulic circuit 50 a, the manual valve 54 is provided in the middle of the oil path 65, not in the middle of the oil path 63. As a result, at each shift position where no hydraulic pressure is required for the forward clutch C1 or the reverse brake B1, the hydraulic pressure can be reliably removed from the forward clutch C1 or the reverse brake B1 or both via the drain EX1. It has become.

  In such a hydraulic circuit 50a as well, as described in the first embodiment, the electromagnetic switching valve 55 is in an OFF (shut off) state except when the drive of the oil pump 51 is started. Is supplied to the forward clutch C1 via the first oil passage 63a, the three-way check valve 75, and the oil passage 65. Further, the hydraulic pressure generated by the oil pump 51 is stored in the accumulator 56 via the second oil passage 63b. When the oil pump 51 is stopped, the supply of hydraulic pressure to the forward clutch C1 is stopped. At this time, hydraulic pressure is held in the accumulator 56.

  Thereafter, when the oil pump 51 is driven, the electromagnetic switching valve 55 is turned on (communication), and the hydraulic pressure stored in the accumulator 56 is supplied to the second oil passage 63b, the three-way check valve 75, and the oil passage. Via 65, it is supplied to the forward clutch C1. At this time, the hydraulic pressure from the accumulator 56 is supplied not only in the direction to the merging portion but also in the direction toward the branching portion via the second oil passage 63b, but the latter oil flow is caused by the one-way valve 71. Be blocked. That is, the hydraulic pressure from the accumulator 56 is surely prevented from leaking from the branch portion.

  Therefore, also in the drive system according to the second embodiment, the hydraulic pressure can be efficiently supplied from the accumulator 56 to the forward clutch C1 in a short time while minimizing the capacity of the accumulator 56. In addition, the other effects described in the first embodiment can be obtained.

(Third embodiment)
Finally, a third embodiment will be described. The third embodiment is different from the first and second embodiments in that the present invention is applied to a stepped automatic transmission (stepped AT). However, the basic configuration of the third embodiment is substantially the same as that of the first embodiment, and is provided with a stepped automatic transmission 80 instead of the continuously variable transmission 30 (see FIG. 1). The configuration of the provided hydraulic circuit is different. For this reason, in the following, the same reference numerals are given to the same components as those in the first embodiment, the description thereof is omitted as appropriate, and the difference in the vehicle drive system according to the third embodiment is mainly described. The hydraulic circuit will be described with reference to FIG. FIG. 6 is a diagram showing a hydraulic circuit in a vehicle drive system (stepped automatic transmission) according to the third embodiment. Here, the case where the forward clutch C1 is engaged in all the forward stages in the D range is illustrated.

  As shown in FIG. 6, in the hydraulic circuit 50b, the clutch pressure control valve is not provided, but the line pressure regulator valve 52 and the manual valve 54b are provided. A branch oil passage 63 c branched from the first oil passage 63 a is provided and connected to the shift valve / control valve unit 81. The shift valve / control valve unit 81 is connected to an oil passage 66 having one end connected to the manual valve 54b in addition to the branch oil passage 63c.

  Here, the shift valve / control valve unit 81 controls engagement / release of the clutches C2, C3 and brakes B1, B2 provided in the stepped automatic transmission 80. Therefore, the clutch C2 and the shift valve / control valve unit 81 are connected by the oil passage 82, the clutch C3 and the shift valve / control valve unit 81 are connected by the oil passage 83, and the brake B1 and the shift valve / control valve unit are connected. 81 is connected by an oil passage 84, and the brake B <b> 2 and the shift valve / control valve unit 81 are connected by an oil passage 85. As a result, when the manual valve 54b is set to the D range, the clutches C2 and C3 and the brakes B1 and B2 are engaged / released by hydraulic control of the shift valve / control valve unit 81 according to the traveling state of the vehicle. The combination pattern is changed, and the stepped automatic transmission 80 is shifted to a predetermined step.

  In such a hydraulic circuit 50b as well, as described in the first embodiment, the electromagnetic switching valve 55 is in an OFF (shut off) state except when the oil pump 51 starts to be driven. Is supplied to the forward clutch C1 via the first oil passage 63a, the three-way check valve 75, and the oil passage 65. Further, the hydraulic pressure generated by the oil pump 51 is stored in the accumulator 56 via the second oil passage 63b. When the oil pump 51 is stopped, the supply of hydraulic pressure to the forward clutch C1 is stopped. At this time, hydraulic pressure is held in the accumulator 56.

  Thereafter, when the oil pump 51 is driven, the electromagnetic switching valve 55 is turned on (communication), and the hydraulic pressure stored in the accumulator 56 is supplied to the second oil passage 63b, the three-way check valve 75, and the oil passage. Via 65, it is supplied to the forward clutch C1. At this time, the hydraulic pressure from the accumulator 56 is supplied not only in the direction to the merging portion but also in the direction toward the branching portion via the second oil passage 63b, but the latter oil flow is caused by the one-way valve 71. Be blocked. That is, the hydraulic pressure from the accumulator 56 is surely prevented from leaking from the branch portion.

  Therefore, also in the drive system according to the third embodiment, the hydraulic pressure can be efficiently supplied from the accumulator 56 to the forward clutch C1 in a short time while minimizing the capacity of the accumulator 56. As for the other effects described above, the same effect can be obtained in the vehicle drive system according to the third embodiment except for the effect of preventing the slip of the V belt in the continuously variable transmission.

  It should be noted that the above-described embodiment is merely an example and does not limit the present invention in any way, and various improvements and modifications can be made without departing from the scope of the invention. For example, in the third embodiment, the manual valve 54 b is disposed in the middle of the oil passage 63, but may be disposed in the middle of the oil passage 65.

  In the above-described embodiment, the mechanical oil pump 51 connected to the engine 10 is exemplified. However, the present invention is also applied to a vehicle drive system including an electric oil pump that is not connected to the engine. Can be applied.

It is a lineblock diagram showing a schematic structure of a vehicle drive system concerning a 1st embodiment. It is a figure which shows the hydraulic circuit with which a continuously variable transmission is equipped. It is a flowchart which shows the content of the engine stop process by a control part. It is a flowchart which shows the content of the engine restart process by a control part. It is a figure which shows the hydraulic circuit in the vehicle drive system which concerns on 2nd Embodiment. It is a figure which shows the hydraulic circuit in the vehicle drive system (stepped automatic transmission) which concerns on 3rd Embodiment.

Explanation of symbols

10 Engine 11 Injector 12 Starter 13 Igniter 14 Crank position sensor 17 Throttle valve 17a Throttle position sensor 18 Ignition switch 19d Brake pedal switch 21 Fuel relay 22 Starter relay 23 Ignition relay 30 Continuously variable transmission (CVT)
31 Primary pulley 32 Secondary pulley 35 Shift position switch 36 Vehicle speed sensor 37 Oil temperature sensor 40 Control unit 50 Hydraulic circuit 51 Oil pump 52 Line pressure regulator valve 53 Clutch pressure control valve 54 Manual valve 55 Electromagnetic switching valve 56 Accumulator 57 Shift control valve 58 Secondary sheave pressure control valve 63a First oil passage 63b Second oil passage 71 One-way valve (first)
72 One-way valve (second)
74 Orifice 75 Three-way check valve C1 Forward clutch B1 Reverse brake EX2 Drain

Claims (3)

An oil pump that generates hydraulic pressure, a hydraulic servo that is controlled by hydraulic pressure, an accumulator that stores the hydraulic pressure generated by the oil pump, and a shut-off / communication state of an oil passage that is connected between the accumulator and the hydraulic servo. A vehicular drive device comprising: a switching valve for switching, wherein the oil pump is stopped and driven as necessary, and has a hydraulic circuit that supplies hydraulic pressure stored in the accumulator to the hydraulic servo at the start of oil pump driving.
The oil passage that connects between the oil pump and the hydraulic servo has a first oil passage and a second oil passage that branch off at a branching portion and join at a joining portion,
A three-way check valve is disposed at the junction,
One port of the three-way check valve is connected to the hydraulic servo, and the remaining two ports are connected to the first oil passage and the second oil passage, respectively.
In the second oil passage, a one-way valve that allows oil to flow only in the direction from the branch portion to the junction portion, the accumulator, and the switching valve are arranged in this order from the branch portion. ,
The three-way check valve communicates the hydraulic servo with the higher hydraulic pressure of the first oil passage and the second oil passage,
The vehicle drive device according to claim 1, wherein the switching valve is in a communication state only for a predetermined time at the start of driving of the oil pump. The vehicle drive device according to claim 1,
A vehicle drive device, wherein a throttle valve is provided between the branch portion of the second oil passage and the one-way valve. In the vehicle drive device according to claim 1 or 2,
The vehicle drive device according to claim 1, wherein the switching valve includes a drain that discharges oil accumulated between the switching valve and the merging portion to the outside of the circuit when the switching valve is turned off.

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