JP2009144874A - Vehicle driving device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle driving device capable of smoothly starting a vehicle when driving an oil pump again, by quickly supplying hydraulic pressure to a plurality of hydraulic servos from an accumulator. <P>SOLUTION: A hydraulic circuit 50 is provided in a continuously variable transmission 30. Oil passages 60, 61, 63 and 63b are arranged for connecting the accumulator 56 and the oil pump 51. The oil passage 63b is provided with one-way valve 71 for making oil flow only in the direction to the accumulator 56 from the oil pump 51. Three-way check valves 75 and 76 are respectively connected via oil passages 65 and 70 to a forward clutch C1 and a secondary pulley 32, and oil passages 64 and 69 connected to the accumulator 56 and oil passages 63a and 68 connected to the oil pump 51, are respectively connected to residual two ports of the valves 75 and 76. Out of the oil passages 64, 63a, 69 and 68, the oil passage higher in the hydraulic pressure is communicated with the oil passages 65 and 70 by the valves 75 and 76. <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. As one of them, 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.
JP 2000-313252 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.

  Here, when the engine is restarted (when the oil pump is re-driven), in addition to the forward clutch, unless the pulley provided in the continuously variable transmission or the predetermined clutch provided in the stepped automatic transmission is quickly engaged, The vehicle may not start smoothly. This is because, in the case of a continuously variable transmission, there is a possibility that the belt slips at the time of starting, and in the case of a stepped automatic transmission, there is a possibility that a shock may occur at the time of starting due to a delay in engagement. However, with the technique described in Patent Document 1, the hydraulic pressure cannot be supplied from the accumulator to the forward clutch and other hydraulic servos (that is, a plurality of hydraulic servos). For this reason, there is a possibility that the vehicle cannot be started smoothly when the engine is restarted (when the oil pump is re-driven).

  Accordingly, the present invention has been made to solve the above-described problems, and can quickly supply hydraulic pressure from an accumulator to a plurality of hydraulic servos, and smoothly start the vehicle when the oil pump is re-driven. It is an object of the present invention to provide a vehicular drive device.

  In order to solve the above problems, a vehicle drive device according to the present invention includes an oil pump that generates hydraulic pressure, a pressure regulating valve that regulates hydraulic pressure generated by the oil pump, and a plurality of hydraulic pressure controlled valves. In the vehicle drive device, comprising: a hydraulic servo; and an accumulator that stores the hydraulic pressure generated by the oil pump, and having a hydraulic circuit that supplies hydraulic pressure to the hydraulic servo from either the pressure regulating valve or the accumulator. A pressure accumulation oil passage connecting between the oil pump and the oil pump, and the pressure accumulation oil passage is provided with a one-way valve for flowing oil only in a direction from the oil pump to the accumulator. A three-way check valve is arranged in each oil passage for supplying hydraulic pressure to the servo. One port is connected to an oil passage connected to each of the hydraulic servos, and the remaining two ports are connected to an oil passage connected to the accumulator and an oil passage connected to the pressure regulating valve, respectively. Each of the three-way check valves is characterized in that the higher one of the oil passages connected to the remaining two ports communicates with the oil passage connected to each of the hydraulic servos.

  In this vehicle drive device, the hydraulic pressure generated by the oil pump is stored in the accumulator via the pressure accumulating oil passage and is supplied to each hydraulic servo via the three-way check valve. This is because, in a normal time when the oil pump is driven, in the oil passage connected to the remaining two ports of the three-way check valve, the oil pressure in the accumulator side oil passage is lower than the oil pressure in the pressure regulating valve side oil passage. For this reason, each three-way check valve communicates the pressure regulating valve side oil passage with each oil passage connected to each hydraulic servo.

  When the oil pump stops, the oil pressure in the pressure regulating valve side oil passage decreases in the oil passage connected to the remaining two ports of the three-way check valve. At this time, when the oil pressure in the pressure regulating valve side oil passage becomes lower than the oil pressure in the accumulator side oil passage, each three-way check valve causes the accumulator side oil passage to communicate with each oil passage connected to each hydraulic servo. Thus, when the oil pump is stopped, the hydraulic pressure is supplied from the accumulator to each hydraulic servo, so that there is no delay in the hydraulic pressure supply to each hydraulic servo when the oil pump is redriven. That is, when the oil pump is restarted, the hydraulic pressure is promptly supplied from the accumulator to each hydraulic servo. Therefore, the vehicle can be started smoothly when the oil pump is driven again.

  In the vehicle drive device according to the present invention, the oil passage connecting and disconnecting each of the three-way check valves and the accumulator is switched, and the switching is performed only for a predetermined time when the oil pump starts driving. It is desirable to have a valve.

  With such a configuration, the switching valve is shut off except when the oil pump starts to be driven. Therefore, even if the oil pump is stopped, each accumulator is operated from the accumulator until the oil pump is started again. No hydraulic pressure is supplied to When the oil pump is started again, the switching valve is brought into a communication state only for a predetermined time, so that the hydraulic pressure is supplied from the accumulator to each hydraulic servo. In addition, what is necessary is just to set time until an oil pump is driven and hydraulic pressure is supplied to each hydraulic servo from an oil pump as predetermined time.

  Thereafter, when the hydraulic pressure generated by the oil pump is supplied to each three-way check valve via the pressure regulating valve, the hydraulic pressure in the pressure regulating valve side oil passage becomes higher than that in the accumulator side oil passage in each three-way check valve. For this reason, each three-way check valve is connected to each oil passage connected to each hydraulic servo, and the oil pressure generated by the oil pump is supplied to each hydraulic servo.

  Therefore, only when the hydraulic servo requires hydraulic pressure, the hydraulic pressure can be promptly supplied from the oil pump or accumulator to each hydraulic servo. In particular, it is possible to quickly supply the hydraulic pressure from the accumulator to each hydraulic servo at the start of driving of the oil pump that causes a delay in the supply of hydraulic pressure from the oil pump. As a result, the vehicle can be started smoothly when the oil pump is re-driven.

  The hydraulic pressure is supplied from the accumulator to each hydraulic servo only until the oil pump is driven and the hydraulic pressure is supplied from the oil pump to each hydraulic servo (that is, for a predetermined time during which the switching valve is in communication). It only has to be done. Thereby, the capacity | capacitance of an accumulator can be made small.

  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 each of the three-way check valves in the shut-off state to the outside of the circuit. Is desirable.

  With such a configuration, when the switching valve is in the shut-off state, the residual pressure between the switching valve and each three-way check valve can be released. Thereby, in each three-way check valve, a differential pressure between the pressure regulating valve side oil passage and the accumulator side oil passage can be secured (the pressure regulating valve side oil passage is made higher). As a result, when the hydraulic pressure is supplied from the oil pump to each hydraulic servo, the hydraulic pressure regulated by the pressure regulating valve can be stably supplied.

  In the case where the switching valve is provided, the hydraulic pressure generated by the oil pump after the oil pump is started can be reliably supplied to each hydraulic servo via each three-way check valve. Therefore, after the hydraulic pressure is supplied from the accumulator to the hydraulic servo, the hydraulic pressure generated by the oil pump can be supplied promptly (at high speed) to each hydraulic servo.

  In the vehicle drive device according to the present invention, it is desirable that a throttle valve is provided between the pressure regulating valve and the one-way valve in the pressure accumulation oil passage.

  When the oil pump is driven and hydraulic pressure is supplied by the oil pump, the hydraulic pressure is also supplied to the accumulator in addition to each hydraulic servo, but since the throttle valve is provided in the accumulator oil passage, the accumulator is slowly And (at low speed) the hydraulic pressure is stored. For this reason, most of the hydraulic pressure generated by the oil pump can be supplied to each hydraulic servo. Therefore, even when the oil pressure stored in the accumulator is reduced at the start of driving the oil pump, the oil pressure generated by the oil pump is not frequently used for accumulating the accumulator. Therefore, the hydraulic pressure generated by the oil pump after the start of driving the oil pump can be supplied promptly (at high speed) to each hydraulic servo. Thereby, the capacity required for the accumulator can be further reduced.

  In the vehicle drive device according to the present invention, the plurality of hydraulic servos include at least one pulley provided in the pulley-type continuously variable transmission and a friction engagement element that is engaged when the vehicle starts. It is desirable.

  In this way, by applying the present invention to a vehicle drive device including a pulley type continuously variable transmission, hydraulic pressure is quickly supplied from an accumulator to a hydraulic servo that operates when the vehicle starts at the start of oil pump drive. can do. As a result, the vehicle including the pulley type continuously variable transmission can be started smoothly.

  Here, as the at least one pulley provided in the pulley type continuously variable transmission, a secondary pulley is preferable. This is because at the start of driving the oil pump, it is in a state where almost no oil pressure is required to act on the primary pulley, and the oil pressure is required to act on the secondary pulley. For this reason, by quickly supplying hydraulic pressure to the secondary pulley from the accumulator, it is possible to reliably prevent the belt from slipping and to start the vehicle more smoothly.

  Alternatively, in the vehicle drive device according to the present invention, the plurality of hydraulic servos include at least one friction engagement element provided in the stepped automatic transmission and a friction engagement element that is engaged when the vehicle starts. It may be included.

  In this way, by applying the present invention to the vehicle drive device including the stepped automatic transmission, the hydraulic pressure is quickly supplied from the accumulator to the hydraulic servo that operates when the vehicle starts when the oil pump starts driving. be able to. As a result, the vehicle including the stepped automatic transmission can be started smoothly.

  According to the vehicle drive device of the present invention, as described above, the hydraulic pressure can be supplied from the accumulator to the plurality of hydraulic servos when the oil pump is re-driven. As a result, the vehicle can be started smoothly even when the oil pump is driven again.

  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 pulley 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. Such a hydraulic circuit 50 is connected to a hydraulic servo, that is, 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 the predetermined pressure to operate the forward clutch C1 and the reverse brake B1. 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, an oil passage 67 connected to the primary pulley 31 is connected to the oil passage 61 via a shift control valve 57. An oil passage 68 is connected to the oil passage 67. The oil passage 68 is an oil passage connected to a three-way check valve 76 that is connected to the secondary pulley 32 via the oil passage 70. As a result, hydraulic pressure is supplied to the primary pulley 31 and the secondary pulley 32 from the oil pump 51 via the oil passages 67, 68, and 70.

  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 C <b> 1 are connected via oil passages 63 and 63 a, a three-way check valve 75, and an oil passage 65. Further, the manual valve 54 and the reverse brake B 1 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 an oil passage 63a and an oil passage 63b at a branch portion. The oil passage 63a is connected to a three-way check valve 75. On the other hand, the oil passage 63 b is connected to the electromagnetic switching valve 55, and the electromagnetic switching valve 55 is connected to the three-way check valve 75 by the oil passage 64. That is, one of the three ports of the three-way check valve 75 is connected to the oil passage 65, and the oil passage (pressure regulating valve side oil passage) 63a and the oil passage (accumulator side oil passage) 64 are connected to the remaining two ports. Each is connected. The three-way check valve 75 communicates the oil passage 65 with the higher one of the oil passage 63 a and the oil passage 64. Specifically, when the oil pressure in the oil passage 63a is higher than the oil pressure in the oil passage 64 (when the oil pump 51 is driven), the oil passage 65 and the oil passage 63a are separated by the three-way check valve 75. The communication state is established, and the oil passage 65 and the oil passage 64 are cut off. On the contrary, when the oil pressure in the oil passage 63a is lower than the oil pressure in the oil passage 64 (when the oil pump 51 is stopped and the electromagnetic switching valve 55 is in communication (ON) state), the three-way check valve 75 The passage 65 and the oil passage 63a are cut off, and the oil passage 65 and the oil passage 64 are in communication.

  In the oil passage 63b, an orifice 74, a one-way valve 71, and an accumulator 56 are provided in order from a branch portion with the oil passage 63a. The one-way valve 71 is configured to flow oil only in the direction from the branch portion between the oil passage 63a and the oil passage 63b to the accumulator 56. Thereby, when the hydraulic pressure is stored in the accumulator 56, the oil is supplied from the oil pump 51 via the oil passages 60, 61, 63, 63b. In other words, in the present embodiment, the oil passage 60, 61, 63, 63b constitutes a pressure accumulation oil passage. When supplying hydraulic pressure from the accumulator 56, oil does not leak from the oil passage 63b to the oil passage 63.

  The electromagnetic switching valve 55 is controlled to be turned on / off by the control unit 40, and is turned on for a predetermined time when the oil pump 51 starts to be driven, and is otherwise turned off. That is, the communication / blocking between the oil passage 63 b and the oil passage 64 is switched by turning on and off the electromagnetic switching valve 55. In the present embodiment, the oil pressure of the oil pump 51 is supplied to the forward clutch C1 and the secondary pulley 32 after the oil pump 51 is started to drive as the predetermined time during which the electromagnetic switching valve 55 is turned on. The time until is set.

  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 oil passage 64 when the electromagnetic switching valve 55 is in an off state, that is, in a state where the oil passage 63b and the oil passage 64 are blocked. Thereby, in a state where the oil passage 63b and the oil passage 64 are blocked, the residual pressure between the electromagnetic switching valve 55 and the three-way check valve 75 (in the oil passage 64) can be released. Yes.

  In addition, an oil passage 69 connected to the three-way check valve 76 is connected to the oil passage 64. One of the three ports of the three-way check valve 76 is connected to the oil passage 70, and an oil passage (pressure regulating valve side oil passage) 68 and an oil passage (accumulator side oil passage) 69 are connected to the remaining two ports, respectively. It is connected. The three-way check valve 76 communicates the oil passage 70 with the higher one of the oil passage 68 and the oil passage 69. Specifically, when the oil pressure in the oil passage 68 is higher than the oil pressure in the oil passage 69 (when the oil pump 51 is driven), the oil passage 70 and the oil passage 68 are separated by the three-way check valve 76. The communication state is set, and the oil passage 70 and the oil passage 69 are cut off. On the contrary, when the oil pressure in the oil passage 68 is lower than the oil pressure in the oil passage 69 (when the oil pump 51 is stopped and the electromagnetic switching valve 55 is in communication (ON) state), the three-way check valve 76 The passage 70 and the oil passage 68 are blocked, and the oil passage 70 and the oil passage 69 are in communication.

  The oil passage 69 is communicated with or cut off from the oil passage 63b through the oil passage 64 by turning on and off the electromagnetic switching valve 55. Further, the drain EX2 of the electromagnetic switching valve 55 is connected to the oil passage 69 via the oil passage 64 when the electromagnetic switching valve 55 is in an off state, that is, in a state where the oil passage 63b and the oil passage 69 are shut off. It has become. Thereby, in a state where the oil passage 63b and the oil passage 69 are blocked, the residual pressure between the electromagnetic switching valve 55 and the three-way check valve 76 (in the oil passage 69) can be released. Yes.

  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 position of the movable sheave of the primary pulley 31 with respect to the fixed sheave is held or changed by the hydraulic pressure controlled by the shift control valve 57. Further, the position of the movable sheave of the secondary pulley 32 with respect to the fixed sheave is held or changed by the supply / stop of the hydraulic pressure to the secondary pulley 32 by the supply / stop of the hydraulic pressure to the secondary pulley 32. In this manner, 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 turned off, the oil passage 63b and the oil passage 64 are blocked, and the one-way valve 71 prevents hydraulic pressure from leaking from the accumulator 56 to the oil passage 63. 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 oil passage 63b and the oil passage 64 are in communication. That is, when driving of the oil pump 51 is started, the electromagnetic on-off valve 55 is turned on, so that the oil passage 63b communicates with the oil passage 64 and the oil passage 69 connected to the oil passage 64. For this reason, the accumulator 56 and the three-way check valves 75 and 76 communicate with each other. As a result, the hydraulic pressure stored in the accumulator 56 is supplied to the three-way check valve 75 via the oil passages 63b and 64, and is supplied to the three-way check valve 76 via the oil passages 63b, 64 and 69.

  At this time, in the three-way check valve 75, the oil passage 64 and the oil passage 65 communicate with each other because the oil pressure in the oil passage 64 is higher than the oil pressure in the oil passage 63a. In the three-way check valve 76, the oil passage 69 and the oil passage 70 communicate with each other because the oil pressure in the oil passage 69 is higher than the oil pressure in the oil passage 68. As a result, the hydraulic pressure stored in the accumulator 56 is supplied to the forward clutch C1 via the oil passage 63b, the oil passage 64, the three-way check valve 75, and the oil passage 65. The hydraulic pressure stored in the accumulator 56 is also supplied to the secondary pulley 32 via the oil passage 63b, the oil passages 64 and 69, the three-way check valve 76, and the oil passage 70. That is, the hydraulic pressure is supplied from the accumulator 56 to a plurality of hydraulic servos (in this embodiment, two of the forward clutch C1 and the secondary pulley 32).

  Here, the hydraulic pressure supplied from the accumulator 56 is also supplied to the oil passage 63 side via the oil passage 63b. However, the one-way valve 71 is provided between the accumulator 56 and the oil passage 63 in the oil passage 63b. 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 and the secondary pulley 32, the hydraulic pressure is efficiently supplied from the accumulator 56 to the forward clutch C1 and the secondary pulley 32 in a short time. be able to.

  Further, since the hydraulic pressure is not always supplied from the accumulator 56 to the forward clutch C1 and the secondary pulley 32 when the oil pump 51 is stopped, it is not necessary to increase the capacity of the accumulator 56 and a large starter is required. There is nothing. That is, as the accumulator 56, the hydraulic pressure generated in the oil pump 51 when the oil pump 51 starts to be driven is supplied to the forward clutch C1 and the secondary pulley 32 only until the hydraulic pressure generated by the oil pump 51 is supplied to the forward clutch C1 and the secondary pulley 32. It is only necessary to have a capacity that can be supplied.

  Therefore, according to the vehicle drive system of the present embodiment, the hydraulic pressure is efficiently transferred from the accumulator 56 to the forward clutch C1 and the secondary pulley 32 in a short time when the engine is restarted while minimizing the capacity of the accumulator 56. Can be supplied.

  When the engine 10 is started, the electromagnetic switching valve 55 is turned off and the oil passage 63b and the oil passage 64 are 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 oil passage 63a and the oil passage 63b via the oil passages 60, 61, 63, and the oil passages 60, 61, 67 are And supplied to the oil passage 68. Here, an orifice 74 is provided in the oil passage 63 b between the branch portion with the 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 oil passage 63b in which the orifice 74 is provided. 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 and the secondary pulley 32, the hydraulic pressure stored in the accumulator 56 decreases. In this state, 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 oil passage 64 and the port of the three-way check valve 76 connected to the oil passage 69 are Each communicates with drain EX2. For this reason, the residual pressure of the oil passages 64 and 69 can be reliably extracted. Therefore, in the three-way check valve 75, the oil pressure of the oil passage 63a can be made higher than the oil pressure of the oil passage 64, and the oil passage 63a and the oil passage 65 can be reliably communicated. Similarly, in the three-way check valve 76, the oil pressure of the oil passage 68 can be made higher than the oil pressure of the oil passage 69, and the oil passage 68 and the oil passage 70 can be reliably communicated.

  Therefore, the hydraulic pressure generated in the oil pump 51 when the oil pump 51 starts to be driven is supplied promptly (at high speed) to the forward clutch C1 via the oil passage 63a, and the secondary pulley is connected via the oil passage 68. 32 can be supplied promptly (at high speed). Therefore, the capacity required for the accumulator 56 can be further reduced. Further, when the oil pump 51 is driven (when the engine 10 is restarted), the hydraulic pressure is quickly supplied from the accumulator 56 until the hydraulic pressure from the oil pump 51 is supplied to the secondary pulley 32 (at a high speed). Therefore, an appropriate hydraulic pressure acts on the secondary pulley 32, and the slippage of the V belt in the continuously variable transmission 30 is reliably prevented. Thus, the vehicle can be started smoothly and reliably when the oil pump 51 is driven (when the engine 10 is restarted).

  As described above, according to the drive system according to the first embodiment, the forward clutch C1 and the secondary pulley 32 are connected to the oil pump 51 and the accumulator 56 via the three-way check valves 75 and 76, respectively. It is connected. An orifice 74, a one-way valve 71, an accumulator 56, and an electromagnetic switching valve 55 are arranged in this order from the branching side with the oil passage 63 in the oil passage 63 b in which the accumulator 56 is provided. 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 turned off (shut off), so that the hydraulic pressure generated by the oil pump 51 is supplied to the oil passages 60, 61, 63, 63 a and 3. It is supplied to the forward clutch C 1 via the direction check valve 75 and also supplied to the secondary pulley 32 via the oil passages 60, 61, 67, 68 and the three-way check valve 76. At this time, the hydraulic pressure generated by the oil pump 51 is stored in the accumulator 56 through the oil passage 63b. When the oil pump 51 stops, the supply of hydraulic pressure to the forward clutch C1 and the secondary pulley 32 stops. At this time, hydraulic pressure is held in the accumulator 56.

  After that, 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 advances through the oil passages 63b and 64 and the three-way check valve 75. It is supplied to the secondary clutch 32 through the oil passages 63b, 64, 69 and the three-way check valve 76 while being supplied to the clutch C1. At this time, the hydraulic pressure from the accumulator 56 is also supplied in the direction toward the branch portion (oil path 63) via the oil path 63b, but this oil flow is blocked by the one-way valve 71. That is, the hydraulic pressure from the accumulator 56 is surely prevented from leaking from the branch portion. Thereby, at the start of driving of the oil pump 51 when the engine is restarted, the hydraulic pressure can be quickly supplied from the accumulator 56 to the forward clutch C1 and the secondary pulley 32, and there is no delay in the hydraulic pressure supply. Therefore, the vehicle drive system according to the first embodiment can start the vehicle smoothly.

(Second Embodiment)
Next, a second embodiment will be described. The second embodiment is different from the first embodiment in that the present invention is applied to a stepped automatic transmission (stepped AT). However, the basic configuration of the second embodiment is almost the same as that of the first embodiment, and a stepped automatic transmission 80 is provided 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, and the description thereof is omitted as appropriate. The hydraulic circuit will be described with reference to FIG. FIG. 5 is a diagram showing a hydraulic circuit in the vehicle drive system (stepped automatic transmission) according to the second embodiment. Here, the case where the forward clutch C1 is engaged at all forward stages of the D range and the forward clutch C1 and the clutch C2 are engaged at the first speed of the D range (when the vehicle starts) is illustrated.

  As shown in FIG. 5, in the hydraulic circuit 50a, the clutch pressure control valve is not provided, but the line pressure regulator valve 52 and the manual valve 54a are provided. A branch oil passage 63 c branched from the oil passage 63 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 54a 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. When the vehicle starts, the forward clutch C1 and the clutch C2 are engaged.

  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 oil passages 60, 63, 63a, the three-way check valve 75, and the oil passage 65. The hydraulic pressure generated by the oil pump 51 is stored in the accumulator 56 via the oil passages 60, 63, 63b.

  Further, the hydraulic pressure generated by the oil pump 51 is supplied to the shift valve / control valve unit 81 via the oil passages 60, 63, 63 c. Then, the shift / control valve unit 81 changes the engagement / release combination pattern of the clutches C2 and C3 and the brakes B1 and B2, and the stepped automatic transmission 80 shifts to a predetermined stage.

  When the engine 10 is stopped and 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 engine 10 is restarted (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 oil passages 63b and 64 in three directions. It is supplied to the forward clutch C <b> 1 via the check valve 75 and the oil passage 65. Further, the hydraulic pressure stored in the accumulator 56 is supplied to the clutch C <b> 2 via the oil passages 63 b, 64, 69, the three-way check valve 76, and the oil passage 86. Thus, the forward clutch C1 and the clutch C2 that need to be engaged for vehicle start can be quickly engaged. At this time, the hydraulic pressure from the accumulator 56 is also supplied in the direction toward the oil passage 63 via the oil passage 63 b, but the oil flow is blocked by the one-way valve 71. That is, the hydraulic pressure from the accumulator 56 is reliably prevented from leaking from the oil passage 63.

  Therefore, also in the vehicle drive system according to the second embodiment, the hydraulic pressure can be quickly supplied from the accumulator 56 to the forward clutch C1 and the clutch C2 while reducing the capacity of the accumulator 56. Accordingly, when the oil pump 51 starts to be driven when the engine is restarted, the hydraulic pressure can be quickly supplied from the accumulator 56 to the forward clutch C1 and the clutch C2, and there is no delay in the hydraulic pressure supply. Therefore, the vehicle drive system according to the second embodiment can start the vehicle smoothly.

  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 first embodiment, the hydraulic pressure is supplied from the accumulator 56 to the forward clutch C1 and the secondary pulley 32. Of course, a hydraulic servo other than these two hydraulic servos (for example, the primary pulley 31). Etc.) may be supplied with hydraulic pressure. For example, in order to supply hydraulic pressure from the accumulator 56 to the primary pulley 31, a three-way check valve may be newly provided between the primary pulley 31 and the shift control valve 57.

  In the above-described embodiment, the manual valve 54 is provided in the middle of the oil passage 63, but may be provided in the middle of the oil passage 65 (between the three-way check valve 65 and the forward clutch C1). Furthermore, although the oil path 63b connected to the accumulator 56 is branched from the oil path 63, the oil path 63b can also be branched from other oil paths (for example, the oil path 67).

  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 (stage automatic transmission) which concerns on 2nd 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 60 70 Oil path 71 One-way valve 74 Orifice 75 Three-way check valve 76 Three-way check valve C1 Forward clutch EX2 Drain

Claims (6)

An oil pump that generates hydraulic pressure, a pressure regulating valve that regulates the hydraulic pressure generated by the oil pump, a plurality of hydraulic servos controlled by hydraulic pressure, and an accumulator that stores the hydraulic pressure generated by the oil pump, In the vehicle drive device having a hydraulic circuit that supplies hydraulic pressure to the hydraulic servo from either the pressure regulating valve or the accumulator,
A pressure accumulating oil passage connecting between the accumulator and the oil pump;
The pressure accumulation oil passage is provided with a one-way valve that allows oil to flow only in the direction from the oil pump to the accumulator,
A three-way check valve is arranged in each oil passage for supplying hydraulic pressure to each hydraulic servo,
One port of each of the three-way check valves is connected to an oil passage connected to each of the hydraulic servos, and the remaining two ports are an oil passage connected to the accumulator, and an oil passage connected to the pressure regulating valve. Each connected to
Each of the three-way check valves communicates a higher hydraulic pressure of the oil passages connected to the remaining two ports to an oil passage connected to each of the hydraulic servos. apparatus. The vehicle drive device according to claim 1,
A vehicular drive comprising: a switching valve that switches between a shutoff / communication state of an oil passage connecting each of the three-way check valves and the accumulator and that is in a communication state only for a predetermined time when the oil pump starts driving. apparatus. In the vehicle drive device according to claim 2,
The vehicle switching device according to claim 1, wherein the switching valve includes a drain for discharging oil accumulated between the switching valve and each of the three-way check valves in a shut-off state to the outside of the circuit. The vehicle drive device according to any one of claims 1 to 3,
The vehicle drive device according to claim 1, wherein a throttle valve is provided between the pressure regulating valve and the one-way valve in the pressure accumulation oil passage. The vehicle drive device according to any one of claims 1 to 4,
The plurality of hydraulic servos include at least one pulley provided in a pulley type continuously variable transmission and a friction engagement element that is engaged when the vehicle starts. The vehicle drive device according to any one of claims 1 to 4,
The plurality of hydraulic servos include at least one friction engagement element provided in the stepped automatic transmission, and a friction engagement element that is engaged when the vehicle starts. .

Images