JP2010151238A - Vehicle drive device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle drive device capable of suitably preventing engagement shock of a forward movement clutch in restarting of an engine by certainly accumulating an oil pressure required before stopping of the engine in an accumulator. <P>SOLUTION: The vehicle drive device is provided with an oil pump 51; the forward movement clutch C1 connected to the oil pump 51 through an oil passage; the accumulator 58 for accumulating the oil pressure generated by the oil pump 51 through a branch oil passage 77 branched from the oil passage; a hydraulic sensor 59 for detecting pressure-accumulation of the accumulator 58; and a solenoid opening/closing valve 57 for retaining the oil pressure of the accumulator 58 during stopping of the oil pump 51 and feeding the oil pressure of the accumulator 58 to the forward movement clutch C1 at starting of drive of the oil pump 51 or before starting of drive. When it is determined that the vehicle is stopped and pressure-accumulation of the accumulator 58 is a required pressure P1 or less, the solenoid opening/closing valve 57 is opened before stopping of the engine to accumulate the oil pressure in the accumulator 58. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention is for a vehicle capable of quickly supplying a hydraulic pressure to a hydraulic servo at the time of restarting an engine (vehicle drive source), for example, to quickly engage a friction engagement element capable of starting the vehicle. The present invention relates to a driving device.

  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, an engagement shock occurs because the forward clutch is engaged with the engine blown up.

Therefore, various techniques for preventing such an engagement shock from occurring have been proposed.
For example, Patent Document 1 discloses an oil pump that generates hydraulic pressure, a forward clutch that is controlled by hydraulic pressure, an accumulator that branches and is installed in an oil passage that connects the oil pump and the forward clutch, and that accumulates hydraulic pressure, and an accumulator Is a normally closed type electromagnetic on-off valve that opens or closes the oil passage and opens the electromagnetic on-off valve when the engine is restarted to supply the hydraulic pressure stored in the accumulator to the forward clutch. It is disclosed. According to this technique, since the hydraulic pressure stored in the accumulator is supplied to the forward clutch when the engine is restarted, it is possible to quickly engage the forward clutch and prevent the occurrence of an engagement shock.
JP 2000-313252 A

  However, according to the technique described in Patent Document 1 described above, the hydraulic pressure necessary for the accumulator is not accumulated before the engine is stopped due to factors such as oil leakage from the accumulator and insufficient opening time of the electromagnetic on-off valve. was there. In such a case, even if the electromagnetic on-off valve is opened when the engine is restarted, sufficient hydraulic pressure is not supplied from the accumulator to the forward clutch. As a result, there has been a problem that it is not possible to appropriately prevent the engagement shock of the forward clutch.

  Therefore, the present invention has been made to solve the above-described problems. The hydraulic pressure required before the vehicle drive source is stopped is reliably accumulated in the accumulator, and the hydraulic servo is engaged when the vehicle drive source is restarted. An object of the present invention is to provide a vehicle drive device that can appropriately prevent a combined shock.

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 hydraulic servo that is connected to the oil pump via an oil path and can be controlled by hydraulic pressure, An accumulator for storing the hydraulic pressure generated by the oil pump via a branch oil passage branched from the oil passage; a hydraulic pressure detection means for detecting the hydraulic pressure stored in the accumulator; and the oil installed in the branch oil passage. An electromagnetic on-off valve that holds the hydraulic pressure of the accumulator while the pump is stopped and supplies the hydraulic servo of the accumulator to the hydraulic servo at the start of driving of the oil pump or before the start of driving, and controls the opening / closing of the electromagnetic on-off valve An opening / closing valve control means and a vehicle stop determination means for determining whether or not the vehicle stops, wherein the opening / closing valve control means And when the hydraulic pressure detected by the hydraulic pressure detection means does not reach a predetermined value, the electromagnetic on-off valve is opened before the vehicle drive source is stopped to stop the accumulator. It is characterized by storing hydraulic pressure.
Here, the “oil pump” according to the present invention may be a mechanical pump that operates in conjunction with a vehicle drive source, and is an electric pump that operates by power supply without being directly linked to the vehicle drive source. It may be.

  In this vehicle drive device, the hydraulic pressure generated during driving of the oil pump is stored in the accumulator. On the other hand, when the oil pump is stopped, the hydraulic pressure of the accumulator is held by the electromagnetic on-off valve. The hydraulic pressure of the accumulator is supplied to the hydraulic servo at the start of driving the oil pump or before the start of driving. Here, in this vehicle drive device, when it is determined that the vehicle is stopped by the vehicle stop determination means, and the hydraulic pressure detected by the hydraulic pressure detection means does not reach a predetermined value, the on-off valve control means is the vehicle drive source. Before stopping the operation, the electromagnetic on-off valve is opened to store hydraulic pressure in the accumulator. As described above, when the vehicle is stopped, the hydraulic pressure of the accumulator is confirmed and the hydraulic pressure is surely accumulated in the accumulator before the vehicle drive source is stopped, so that the necessary hydraulic pressure is reliably stored in the accumulator before the vehicle drive source is stopped. Accumulate pressure. As a result, the required hydraulic pressure can be reliably supplied to the hydraulic servo when the vehicle drive source is restarted, and the engagement shock of the hydraulic servo can be prevented appropriately.

  In the vehicle drive device according to the present invention, it is desirable to increase the line pressure of the oil passage when the hydraulic pressure is stored in the accumulator before the vehicle drive source is stopped.

  Thus, by increasing the line pressure of the oil passage and storing the hydraulic pressure in the accumulator, the hydraulic pressure required for the accumulator can be reliably stored in a shorter time before the vehicle drive source is stopped. In addition, although it does not specifically limit as a means to raise line pressure, The aspect using various control valves etc. which are arrange | positioned at the oil path can be illustrated. Further, the timing for increasing the line pressure is not particularly limited, and examples include a mode in which the line pressure is increased simultaneously with the opening of the electromagnetic on-off valve, a mode in which the predetermined pressure is satisfied, and a mode in which the line pressure is increased.

  In the vehicle drive device according to the present invention, it is desirable to increase the rotational speed of the oil pump when the hydraulic pressure is stored in the accumulator before the vehicle drive source is stopped.

  In this way, by increasing the rotational speed of the oil pump and storing the hydraulic pressure in the accumulator, the hydraulic pressure required for the accumulator can be reliably stored in a shorter time before the vehicle drive source is stopped. The timing for increasing the rotational speed of the oil pump is not particularly limited, but it is possible to exemplify a mode of increasing when a predetermined condition is satisfied (for example, when accumulator pressure is not sufficient even if the line pressure is increased).

  In this vehicle drive device, the oil pump is a mechanical pump that operates in conjunction with the vehicle drive source, and the increase in the rotation speed of the oil pump is achieved by increasing the rotation speed of the vehicle drive source. The mode performed can be illustrated.

  Thus, when the oil pump is a mechanical pump that operates in conjunction with the vehicle drive source, the rotation speed of the oil drive can be reliably increased by increasing the rotation speed of the vehicle drive source. . Thereby, the hydraulic pressure required for the accumulator can be more reliably accumulated before the vehicle drive source is stopped.

  In the vehicle drive device according to the present invention, it is desirable that the on-off valve control means further opens the electromagnetic on-off valve for a predetermined time and stores hydraulic pressure in the accumulator even during steady operation of the vehicle drive source. .

  As described above, by storing the hydraulic pressure in the accumulator even during the steady operation of the vehicle drive source in advance, the necessary hydraulic pressure can be reliably stored in a short time by the accumulator before the vehicle drive source is stopped. Further, by accumulating the hydraulic pressure in the accumulator during the steady operation of the vehicle drive source, the hydraulic pressure can be effectively accumulated in the accumulator.

  The vehicle drive device according to the present invention comprises vehicle stoppage determining means for determining whether or not the vehicle is stopped, wherein the vehicle stoppage determination means determines that the vehicle is stopped, and Even when the hydraulic pressure detected by the hydraulic pressure detection means does not reach a predetermined value, it is desirable to open the electromagnetic on-off valve and store the hydraulic pressure in the accumulator before the vehicle drive source is stopped.

  As described above, even when the vehicle stoppage determining means determines that the vehicle is stopped and the oil pressure detected by the oil pressure detection means has not reached a predetermined value, the accumulator is accumulated. The hydraulic pressure required before stopping the vehicle drive source can be most reliably stored in the accumulator. In this case as well, effective pressure accumulation can be performed by increasing the line pressure or increasing the rotational speed of the oil pump as described above.

  By the way, since the time required for the accumulator to store the hydraulic pressure is generally about several seconds, the electromagnetic open / close valve is used to hold the hydraulic pressure more than the time that the electromagnetic open / close valve is opened to store the hydraulic pressure. There was a fact that it took longer to keep the valve closed.

  Therefore, in the vehicle drive device according to the present invention, it is desirable that the electromagnetic on-off valve is a normally closed type that opens when energized and closes when not energized.

  As described above, by adopting a normally closed type electromagnetic on / off valve, the accumulator pressure can be maintained without supplying power to the electromagnetic on / off valve. Thereby, an electromagnetic on-off valve can be controlled efficiently and electric power required for the drive of an electromagnetic on-off valve can be reduced.

  According to the vehicle drive device of the present invention, as described above, the hydraulic pressure required before stopping the vehicle drive source is reliably accumulated in the accumulator, and the hydraulic servo engagement shock is appropriately applied when the vehicle drive source is restarted. Can be prevented.

  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. Here, what applied this invention to the vehicle drive system provided with a continuously variable transmission (CVT) is illustrated. Therefore, the vehicle drive system according to the present embodiment will be described with reference to FIG. FIG. 1 is a diagram showing a schematic configuration of a vehicle drive system according to the present embodiment.

  As shown in FIG. 1, the drive system according to the present embodiment includes an engine 10, a continuously variable transmission 30, a control unit 40 that comprehensively controls the system, the engine 10, the continuously variable transmission 30, and a vehicle And various sensors for detecting the state of the above. The engine 10 of the present embodiment corresponds to a “vehicle drive source” of the present invention.

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 that interlocks 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 through which the output of the engine 10 is input via a torque converter 38 (see FIG. 2), a forward / reverse switching clutch, and the like, and a primary pulley 31 described later is provided on the input shaft. It has been. 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 radius (= rotation speed) ratio between the input shaft and the output shaft, that is, the reduction ratio 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 programs such as an engine stop process and an engine restart process, which will be described later, are written in advance in a ROM in the control unit 40. The control unit 40 corresponds to “open / close valve control means”, “vehicle stop determination means” and “vehicle stop determination means” of the present invention.

  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 controller 40 is connected to an electromagnetic on-off valve 57 and a hydraulic sensor 57 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 on-off valve 57, 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 clutch control valve 54, a shift valve 55, a manual valve 56, and an electromagnetic opening / closing. A valve 57, an accumulator 58, a cutoff valve 60, a shift control valve 65, and a secondary sheave pressure control valve 66 are provided. Such a hydraulic circuit 50 is connected to the forward clutch C 1, the reverse brake B 1, the torque converter 38, and the primary pulley 31 and the secondary pulley 32. The forward clutch C1 corresponds to the “hydraulic servo” of the present invention.

The oil pump 51 is a mechanical pump that operates in conjunction with the engine 10, and serves as a hydraulic pressure source for the entire continuously variable transmission 30. 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 hydraulic pressure (line pressure) regulated by the line pressure regulator valve 52 to a predetermined pressure for operating the forward clutch C1 and the reverse brake B1. The clutch control valve 54 controls the engagement state between the complete engagement and release of the clutch, for example, when the neutral control is performed, the hydraulic pressure adjusted by the clutch pressure control valve 53 is applied to the forward clutch C1. The pressure is controlled to a predetermined pressure for operation. The shift valve 55 selects either the hydraulic pressure adjusted by the clutch pressure control valve 53 or the hydraulic pressure adjusted by the clutch control valve 54 as the hydraulic pressure supplied to the forward clutch C1 or the reverse brake B1. It is.
The operations of these valves 52 to 55 are controlled by solenoids, respectively, and the operation of the valves is controlled by controlling the current supplied to the solenoids.

  The manual valve 56 switches the oil passage in conjunction with the driver's shift position operation. The accumulator 58 temporarily stores the hydraulic pressure generated by the oil pump 51 and regulated by the clutch pressure control valve 53.

  In this hydraulic circuit 50, an oil pump 51 and a line pressure regulator valve 52 are connected by an oil passage 70. Further, the line pressure regulator valve 52 and the torque converter 38 are connected by an oil passage 81. Further, the line pressure regulator valve 52 and the clutch pressure control valve 53 are connected by an oil passage 71. Here, the oil passage 71 is branched into oil passages 82 and 83, and each oil passage 82 and 83 is connected to the primary pulley 31 or the secondary pulley 32, respectively. More specifically, the oil passage 82 is connected to the primary pulley 31 via the shift control valve 65, and the oil passage 83 is connected to the secondary pulley 32 via the secondary sheave pressure control valve 66.

  The oil path 83 is provided with a one-way valve 93 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 66. 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. Therefore, oil leakage in the secondary pulley 32 can be prevented, and air can be prevented from entering. Therefore, after the engine is restarted, air can be prevented from being mixed with the oil supplied by the oil pump, so that the hydraulic performance after the engine restart can be improved.

  The oil passage 82 is provided with a one-way valve 95 that allows oil to flow only from the oil passage 71 toward the primary pulley 31 on the upstream side of the center shift control valve 65. Thereby, when the oil pump 51 is stopped, oil leakage from the primary pulley 31 to the oil passage 71 can be prevented. Therefore, oil leakage in the primary pulley 31 can be prevented, and air can be prevented from entering. Therefore, after the engine is restarted, air can be prevented from being mixed with the oil supplied by the oil pump, so that the hydraulic performance after the engine restart can be improved.

  The oil passage 71 is also branched into an oil passage 85, and the oil passage 85 is connected to the hydraulic chamber 63 of the shutoff valve 60. As a result, the line pressure is supplied to the hydraulic chamber 63 of the shutoff valve 60.

  The clutch pressure control valve 53 and the clutch control valve 54 are connected by an oil passage 72, and the clutch control valve 54 and the shift valve 55 are connected by an oil passage 74. Further, the clutch pressure control valve 53 is connected to the shift control valve 65 via an oil passage 84. An oil passage 73 is formed by branching from the oil passage 72, and the oil passage 73 is connected to the shift valve 55. That is, the oil passage 73 is provided so as to bypass the clutch control valve 54.

  The shift valve 55 and the manual valve 56 are connected by an oil passage 75. The manual valve 56 and the forward clutch C 1 are connected by an oil passage 79, and the manual valve 56 and the reverse brake B 1 are connected by an oil passage 80. Thereby, when the manual valve 56 is set to the forward position (D range), the oil passage 75 and the oil passage 79 are communicated, and the oil passage 80 and the drain EX are connected. . When the manual valve 56 is set to the reverse position (R range), the oil passage 75 and the oil passage 80 communicate with each other, and the oil passage 79 and the drain EX are connected. Further, when the manual valve 56 is set to the neutral position (N range) and the parking position (P range), the oil passage 75 is blocked from both the oil passages 79 and 80, and the oil passages 79 and 80 and the drain are connected. EX is connected. Accordingly, when the manual valve 56 is in a position where hydraulic pressure is not required for the forward clutch C1 (other than the D range), the hydraulic pressure acting on the forward clutch C1 is released from the drain EX, and the hydraulic pressure is applied to the reverse brake B1. At an unnecessary position (other than the R range), the hydraulic pressure acting on the reverse brake B1 is released from the drain EX.

  A branch oil passage 77 having one end connected to the accumulator 58 is connected to the oil passage 75 at a connection point 77a. This branch oil passage 77 corresponds to the “branch oil passage” of the present invention. The oil passage 75 is provided with a shut-off valve 60 that can shut off the oil passage 75 between a connection point 77 a with the branch oil passage 77 and the shift valve 55. The shutoff valve 60 is provided with a slidable valve body 62 in the valve body 61 for switching the oil passage 75 between the communication state and the shutoff state. A compressed spring 64 is provided on one side of the valve body 62, and a hydraulic chamber 63 is provided on the other side. Thereby, the valve body 62 is moved by the force relationship between the urging force from the spring 64 and the hydraulic pressure supplied to the hydraulic chamber 63, and the oil passage 75 is switched between the communication state and the cutoff state. That is, the shutoff valve 60 shuts off the oil passage 75 when hydraulic pressure is not supplied to the hydraulic chamber 63, and allows the oil passage 75 to communicate when hydraulic pressure is supplied to the hydraulic chamber 63.

  The oil passage 75 is provided with a branch oil passage 76. One end of the branch oil passage 76 is connected between the shift valve 55 and the shut-off valve 60 and the other end is connected between the shut-off valve 60 and the connection point 77a so as to bypass the shut-off valve 60. . In the branch oil passage 76, a one-way valve 92 that allows oil to flow only in the direction from the shift valve 55 to the connection point 77a is disposed. As a result, even if the shutoff valve 60 fails and the oil passage 75 remains blocked, the hydraulic pressure generated by the oil pump 51 is supplied to the forward clutch C1 or the reverse brake B1 via the oil passage 76. It can be done.

  On the other hand, the branch oil passage 77 is provided with an electromagnetic on-off valve 57 between the accumulator 58 and the contact 77a. The electromagnetic on-off valve 57 is a normally closed type that opens when energized and closes when de-energized. The electromagnetic opening / closing valve 57 is controlled to open / close by the control unit 40, and is opened when the oil pump 51 is driven, and is closed when the oil pump 51 is stopped. That is, the branch oil passage 77 is communicated / blocked by opening / closing the electromagnetic opening / closing valve 57. A hydraulic oil pressure sensor 59 that detects the hydraulic pressure stored in the accumulator 58 is provided in the branch oil passage 77 between the accumulator 58 and the electromagnetic on-off valve 57. The hydraulic pressure sensor 59 corresponds to the “hydraulic pressure detecting means” of the present invention. In this embodiment, the hydraulic pressure stored in the accumulator 58 is detected by the hydraulic sensor 59. However, the hydraulic pressure of the accumulator 58 is determined based on the opening / closing time of the electromagnetic on-off valve 57 and / or the engine speed. It is good also as a structure to detect.

  Further, the branch oil passage 77 is provided with an orifice 94 between a connection point 77 a with the oil passage 75 and the electromagnetic on-off valve 57. A branch oil passage 78 is provided so as to bypass the orifice 94. A one-way valve 91 that allows oil to flow only in the direction from the accumulator 58 to the oil passage 75 is disposed in the branch oil passage 78. As a result, when the hydraulic pressure is stored in the accumulator 58, the oil passes through the oil passage 78, and when supplying the hydraulic pressure stored from the accumulator 58, the oil passes through the branch oil passage 78.

  Next, the operation of the vehicle drive system having the above configuration will be described. 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 65 and the secondary sheave pressure control valve 66. 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 58 through the oil passages 70 to 75 and 77 in addition to the continuously variable transmission 30.

  In the vehicle drive system according to the present embodiment, the hydraulic pressure generated by driving oil pump 51 is stored in accumulator 58 during steady running of the vehicle. Processing performed by the control unit 40 during the steady vehicle traveling will be described with reference to FIG. FIG. 3 is a flowchart showing the contents of processing during steady vehicle traveling by the control unit.

  As shown in FIG. 3, in step S1, the control unit 40 determines whether or not the vehicle speed is equal to or higher than a predetermined value. Specifically, the control unit 40 makes this determination based on the vehicle speed signal detected from the vehicle speed sensor 36. When the vehicle speed is equal to or higher than the predetermined value (S1: YES), the control unit 40 proceeds to step S2. On the other hand, when the vehicle speed is not equal to or higher than the predetermined value (S1: NO), the control unit 40 ends this processing routine.

In step S2, the control unit 40 determines whether or not the vehicle is in steady operation. Specifically, the control unit 40 makes this determination based on each signal detected from the vehicle speed sensor 36 or the like. When it is determined that the vehicle is in steady operation (S2: YES), the control unit 40 proceeds to step S3. On the other hand, when it is determined that the vehicle is not in steady operation (S2: NO), the control unit 40 ends this processing routine.
Here, the “steady operation of the vehicle” refers to an operation when it is determined that it is not necessary to control the engagement state between complete engagement and release of the clutch.

  In step S <b> 3, the control unit 40 opens the electromagnetic opening / closing valve 57 (ON state). Specifically, the control unit 40 supplies power to the electromagnetic on-off valve 57 to energize it. Here, since the electromagnetic on-off valve 57 of this embodiment is a normally closed type, the energization opens the electromagnetic on-off valve 57. As a result, the branch oil passage 77 is in a communicating state, and the hydraulic pressure of the oil pump 51 is stored in the accumulator 58. And the control part 40 transfers a process to step S4.

  In step S4, the control unit 40 stops the process until a predetermined time has elapsed. Here, as the predetermined time, a time until the hydraulic pressure in the accumulator 58 becomes equal to or more than a necessary value may be set, and is determined according to the capacity of the accumulator 58. Note that it may be determined whether or not a predetermined hydraulic pressure is stored in the accumulator 58 based on a hydraulic pressure signal from the hydraulic pressure sensor 59. And the control part 40 transfers a process to step S5, after predetermined time passes.

In step S5, the electromagnetic on-off valve 57 is closed (OFF state). Specifically, the control unit 40 stops energization of the electromagnetic opening / closing valve 57. Here, as described above, since the electromagnetic on-off valve 57 is a normally closed type, when the energization to the electromagnetic on-off valve 57 is stopped, the electromagnetic on-off valve 57 is closed. As a result, the branch oil passage 77 is cut off, and the hydraulic pressure accumulated in the accumulator 58 is maintained. Then, the control unit 40 ends the subsequent processing.
As described above, the hydraulic pressure necessary for the accumulator 58 is accumulated during steady running of the vehicle.

  In the vehicle drive system according to the present embodiment, the engine 10 is temporarily stopped (idling stop) by the control unit 40 when a predetermined condition is satisfied. The engine stop process will be described with reference to FIG. FIG. 4 is a flowchart showing the contents of the engine stop process by the control unit.

  As shown in FIG. 4, in step S11, the control unit 40 determines whether or not the vehicle speed is equal to or less than a predetermined value. Specifically, the control unit 40 makes this determination based on a vehicle speed signal detected from the vehicle speed sensor 36. And when it is judged that a vehicle speed is below a predetermined value (S11: YES), the control part 40 transfers a process to step S12. On the other hand, when it is determined that the vehicle speed is equal to or lower than the predetermined value (S11: NO), the control unit 40 ends this processing routine.

  In step S12, the control unit 40 determines whether or not the Acc pressure (accumulated pressure in the accumulator 58) is equal to or greater than a predetermined value. Specifically, the control unit 40 makes this determination based on the oil pressure detected by the oil pressure sensor 59. And when it is judged that Acc pressure is more than predetermined value (S12: YES), control part 40 shifts processing to Step S13. On the other hand, when it is determined that the Acc pressure is not equal to or higher than the predetermined value (S12: NO), the control unit 40 proceeds to step S21.

  In step S13, the control unit 40 determines whether or not the vehicle speed is zero. Specifically, the control unit 40 makes this determination based on a vehicle speed signal detected from the vehicle speed sensor 36. And when it judges that a vehicle speed is zero (S13: YES), the control part 40 transfers a process to step S14. On the other hand, when it is determined that the vehicle speed is not zero (S13: NO), the control unit 40 ends this processing routine.

  In step S14, the control unit 40 determines whether or not the rotational speed (= rotational speed) of the engine 10 is equal to or lower than a predetermined rotational speed. Specifically, the control unit 40 makes this determination based on the engine speed signal detected from the crank position sensor 14. Here, examples of the predetermined rotational speed include a rotational speed slightly higher than the idle rotational speed. And when it is judged that the rotation speed of the engine 10 is below a predetermined rotation speed (S14: YES), the control part 40 transfers a process to step S15. On the other hand, when it is determined that the rotational speed of the engine 10 is not less than or equal to the predetermined rotational speed (S14: NO), the control unit 40 ends this processing routine.

  In step S15, the control unit 40 determines whether or not the accelerator opening is zero. Specifically, the control unit 40 makes this determination based on the accelerator opening signal detected from the throttle position sensor 17a. And when it is judged that the accelerator opening is zero (S15: YES), the control part 40 transfers a process to step S16. On the other hand, when it is determined that the accelerator opening is not zero (S15: NO), the control unit 40 ends this processing routine.

  In step S16, the control unit 40 determines whether or not the brake switch is ON. Specifically, the control unit 40 makes this determination based on a signal detected from the brake pedal switch 19d. In order to more accurately determine whether or not the brake pedal switch 19d is turned on, that is, whether or not the brake device of the vehicle is operating, the detection signal from the brake master cylinder pressure sensor 19e is also considered. You may do it. In this case, for example, it is determined that the brake switch is turned on only when the brake pedal switch 19d is turned on and the pressure detected by the brake master cylinder pressure sensor 19e is equal to or higher than a predetermined value. do it. And when it is judged that a brake switch is ON (S16: YES), the control part 40 transfers a process to step S17. On the other hand, when it is determined that the brake switch is not ON (S16: NO), the control unit 40 ends this processing routine.

In step S17, the control unit 40 determines again whether or not the Acc pressure is equal to or higher than a predetermined value. This determination is also made based on the oil pressure detected by the oil pressure sensor 59. When it is determined that the Acc pressure is equal to or higher than the predetermined value (S17: YES), the control unit 40 proceeds to step S18. On the other hand, when it is determined that the Acc pressure is not equal to or greater than the predetermined value (S17: NO), the control unit 40 proceeds to step S21.
Since it is determined that the Acc pressure is equal to or higher than the predetermined value in step S12, it is considered that there are few cases where it is determined in step S17 that the Acc pressure is not higher than the predetermined value. However, by confirming the accumulated pressure of the accumulator 58 again in this step S17, the hydraulic pressure required for the accumulator 58 can be more reliably accumulated before the engine is stopped.

  In step S18, the control unit 40 determines whether or not other engine stop conditions are satisfied. Here, as other engine stop conditions, for example, climbing / inclination determination based on an output signal from the G sensor 19a (condition is established when the inclination angle is equal to or smaller than a predetermined value), engine based on an output signal from the water temperature sensor 19b Water temperature determination (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 equal to or higher than a predetermined value), based on the output signal from the oil temperature sensor 37 CVT oil temperature determination (condition is satisfied when CVT oil temperature is within a predetermined range), elapsed time since the previous engine start (condition is satisfied when it is longer than a predetermined time), vehicle speed history (condition is satisfied when it is higher than a predetermined value), etc. Can be mentioned. And when it is judged that the other engine stop conditions are satisfied (S18: YES), the control part 40 transfers a process to step S19. On the other hand, when it is determined that other engine stop conditions are not satisfied (S18: NO), the control unit 40 ends this processing routine.

  In step S19, the control unit 40 stops the engine 10. Specifically, the control unit 40 outputs a fuel cut signal, an ignition cut signal, and the like that constitute an engine stop signal to the fuel relay 21, the ignition relay 23, and the like. As a result, high voltage is not supplied from the igniter 13 to the spark plug, and fuel is not injected from the injector 11 to stop the engine 10 (idling stop). Then, the control unit 40 ends the subsequent processing. 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 on-off valve 57 is closed (OFF state) and the branch oil passage 77 is shut off. Therefore, the hydraulic pressure of the accumulator 58 is maintained.

[When it is determined in steps S12 and S17 that the Acc pressure is not equal to or higher than the predetermined value (S12: NO, S17: NO)]
In step S21, the control unit 40 opens the electromagnetic opening / closing valve 57 (ON state). That is, the control unit 40 opens the electromagnetic on-off valve 57 by supplying power to the electromagnetic on-off valve 57 and energizing it as described above. As a result, the branch oil passage 77 is in a communicating state, so that the hydraulic pressure of the oil pump 51 is stored in the accumulator 58. And the control part 40 transfers a process to step S22.

  In step S <b> 22, the control unit 40 increases the line pressure of the hydraulic circuit 50. Specifically, the controller 40 increases the line pressure by changing the amount of current supplied to the solenoid that controls the operation of the clutch pressure control valve 54 and the like. And the control part 40 transfers a process to step S23.

  In step S23, the control unit 40 stops the process until a predetermined time has elapsed. As the predetermined time, the time until the hydraulic pressure in the accumulator 58 becomes a required value or more is set as described above. Here, by increasing the line pressure of the hydraulic circuit 50 and storing the hydraulic pressure in the accumulator 58, the hydraulic pressure required for the accumulator 58 can be reliably stored in a shorter time before the engine 10 is stopped. And the control part 40 transfers a process to step S24, after predetermined time passes.

  In step S24, the control unit 40 determines whether or not the Acc pressure is greater than or equal to a predetermined value. That is, the control unit 40 makes this determination based on the hydraulic pressure detected by the hydraulic sensor 59 as described above. And when it is judged that Acc pressure is more than predetermined value (S24: YES), control part 40 shifts processing to Step S25. On the other hand, when it is determined that the Acc pressure is not equal to or higher than the predetermined value (S24: NO), the control unit 40 proceeds to step S31.

  In step S25, the controller 40 closes the electromagnetic open / close valve 57 (OFF state). That is, the control unit 40 closes the electromagnetic on-off valve 57 by stopping energization of the electromagnetic on-off valve 57. Then, the control unit 40 ends the subsequent processing.

[When it is determined in step S24 that the Acc pressure is not equal to or higher than the predetermined value (S24: NO)]
In step S31, the control unit 40 increases the engine speed. In the present embodiment, since the oil pump 51 is a mechanical pump that operates in conjunction with the engine 10, the rotational speed of the oil pump 51 is increased by increasing the engine speed. Thereby, the oil flow rate of the entire hydraulic circuit 50 can be increased. The control unit 40 may gradually increase the engine speed, or may increase the engine speed to a predetermined speed and maintain the speed. Thus, by increasing the rotational speed of the oil pump 51 and accumulating the hydraulic pressure in the accumulator 58, the hydraulic pressure required for the accumulator 58 can be reliably accumulated in a shorter time before the engine 10 is stopped. And the control part 40 transfers a process to step S24. That is, the control unit 40 does not shift the process to step S25 until the hydraulic pressure necessary for the accumulator 58 is accumulated.

When the engine 10 is temporarily stopped as described above, the control unit 40 executes a restart processing routine of the engine 10 after idling stop.
Therefore, the restart process after idling stop (temporary stop) of the engine 10 will be described with reference to FIG. FIG. 5 is a flowchart showing the contents of the engine restart process by the control unit.

  In step S42, the control unit 40 determines whether or not a restart condition for the engine 10 is satisfied. Here, examples of the engine restart condition include a vehicle speed being zero, a brake switch being OFF, and an accelerator opening being not zero. And when it is judged that the restart conditions of the engine 10 are satisfied (S42: YES), the control part 40 transfers a process to step S43. On the other hand, when it is determined that the restart condition of the engine 10 is not satisfied (S42: NO), the control unit 40 ends this processing routine.

  In step S43, the control unit 40 opens the electromagnetic opening / closing valve 57 (ON state). That is, the controller 40 opens the electromagnetic on-off valve 57 by energizing the electromagnetic on-off valve 57 as described above. As a result, the branch oil passage 77 is in a communicating state, and the hydraulic pressure stored in the accumulator 58 is supplied to the forward clutch C1. And the control part 40 transfers a process to step S44.

  In step S44, the control unit 40 stops the process until a predetermined time has elapsed. Here, the predetermined time is not particularly limited, but about 50 ms can be exemplified in consideration of the time required to complete the opening of the electromagnetic on-off valve 57. And the control part 40 transfers a process to step S44.

In step S45, the control unit 40 starts the starter 12. Specifically, the control unit 40 outputs a starter drive signal constituting an engine restart signal to the starter relay 22. And the control part 40 transfers a process to step S46.
In step S46, the control unit 40 outputs a fuel injection signal, an ignition signal, etc. constituting other engine restart signals to the fuel relay 21, the ignition relay 23, etc., respectively.
As described above, the starter 12 is driven, a high voltage is supplied from the igniter 13 to the spark plug, and fuel is injected from the injector 11. Thus, the engine 10 is restarted.

  In the present embodiment, as described above, the electromagnetic on-off valve 57 is opened before the restart of the engine 10 and a predetermined time elapses, whereby the switching electromagnetic valve 57 is supplied before a large current is supplied to the starter 12 or the like. Can be opened. Thereby, the current required for opening the electromagnetic on-off valve 57 can be ensured, and the electromagnetic on-off valve 57 can be reliably opened when the engine 10 is restarted. As a result, when the engine 10 is restarted, the hydraulic pressure of the accumulator 58 can be reliably supplied to the forward clutch C1.

  Next, an example of behavior indicated by the C-1 pressure (hydraulic pressure acting on the forward clutch C1) and the Acc pressure under the control of the control unit 40 will be described with reference to FIG. FIG. 6 is a time chart showing an example of the behavior of the C-1 pressure and the Acc pressure.

[Behavior during steady driving]
In FIG. 6, at time t1, as shown in (b), the vehicle speed is constant at a predetermined value (S1: YES, S2: YES). At this time, as shown in (g), the control unit 40 opens the electromagnetic on-off valve 57 (step S3). As a result, the branch oil passage 77 is brought into a communication state, so that the Acc pressure gradually increases as shown in (f). And when predetermined time passes, the control part 40 will close the electromagnetic on-off valve 57, as shown to (g) (step S4, step S5). As a result, as shown in (f), the accumulator 58 holds a predetermined hydraulic pressure. At this time, in the example shown in FIG. 6, the Acc pressure does not reach the necessary pressure P1.

[Behavior when the engine is stopped]
When the time reaches t2, as shown in (a), the brake switch is stepped on by the driver of the vehicle. As a result, the vehicle speed gradually decreases as shown in FIG. When the vehicle speed decreases to a predetermined value (for example, 5 to 10 km / h) at time t3, the control unit 40 determines whether or not the Acc pressure has reached the necessary pressure P1 (step S12). This example corresponds to the case where the Acc pressure has not reached the required pressure P1 (S12: NO). Therefore, the control unit 40 opens the electromagnetic opening / closing valve 57 as shown in (g) (step S21). At this time, the control unit 40 also increases the line pressure as shown in (d) (step S22). As the line pressure increases, the C-1 pressure and the Acc pressure also increase as shown in (e) and (f). In this example, as shown in (f), since the Acc pressure reaches the necessary pressure P1 at time t4 (S24: YES), the control unit 40, as shown in (g), 57 is closed (step S25). When the Acc pressure does not reach the required pressure P1 or when it is desired to accumulate pressure in a shorter time, the engine speed may be increased as indicated by a broken line in (c). Thereby, since the rotational speed of the oil pump 51 can be raised, the flow volume of the oil which flows through the hydraulic circuit 50 whole can be increased. As a result, the Acc pressure can reliably reach the required pressure P1 in a shorter time. Then, the control unit 40 stops the vehicle as shown in (b) at time t4, and stops the engine 10 as shown in (c) at time t5 (step S19).

[Behavior at engine restart]
Subsequently, when the time reaches t6, as shown in (a), the brake is turned off, and the restart condition is satisfied at time t7 (step S42). For this reason, the control part 40 opens the electromagnetic on-off valve 57 as shown to (g) (step S43). As the electromagnetic on-off valve 57 is opened, the hydraulic pressure of the accumulator 58 is supplied to the forward clutch C1, so that the C-1 pressure increases as shown in (e), and the Acc as shown in (f). The pressure drops. Then, at time t8 after elapse of 50 ms from time t7, for example, a starter signal is output from the control unit 40 as shown in (h), and the engine speed (E / G speed) is shown in (c). It begins to rise (steps S44 to S46). At time t9, the control unit 40 closes the electromagnetic on-off valve 57 as shown in (g) and stops the output of the starter signal as shown in (h).

  Since the time required for the accumulator 58 to store the hydraulic pressure is generally about several seconds, as shown in FIG. 6G, the electromagnetic on-off valve 57 is opened (ON) to store the hydraulic pressure. There is a situation in which the time for which the electromagnetic on-off valve 57 is closed (OFF) in order to maintain the hydraulic pressure is longer than the time for which the pressure is kept. On the other hand, in this embodiment, a normally closed type is adopted as the electromagnetic on-off valve 57. As a result, the accumulated pressure in the accumulator 58 can be maintained without supplying power to the electromagnetic opening / closing valve 57. As a result, the electromagnetic on-off valve 57 can be efficiently controlled, and the electric power required for driving the electromagnetic on-off valve 57 can be reduced.

  As described above, in the vehicle drive system according to the present embodiment, the hydraulic pressure generated while the engine 10 is being driven is stored in the accumulator 58. On the other hand, when the engine 10 is stopped, the hydraulic pressure of the accumulator 58 is held by the electromagnetic on-off valve 57. When the engine 10 is restarted, the hydraulic pressure of the accumulator 58 is supplied to the forward clutch C1. Here, in this system, when the vehicle speed decreases and the Acc hydraulic pressure does not reach the required pressure P1, the control unit 40 opens the electromagnetic on-off valve 57 and stores the hydraulic pressure in the accumulator 58. ing. As described above, when the vehicle is stopped, the hydraulic pressure of the accumulator 58 is confirmed, and the necessary pressure P1 is reliably accumulated in the accumulator 58 before the engine 10 is stopped. By reliably supplying the clutch C1, it is possible to appropriately prevent the engagement shock of the forward clutch C1.

  Further, in this vehicle drive system, the required pressure P1 is applied to the accumulator 58 in a shorter time before the engine 10 is stopped by increasing the line pressure of the hydraulic circuit 50 or increasing the rotational speed of the oil pump 51. Accumulate pressure reliably. Furthermore, by storing the hydraulic pressure in the accumulator 58 in advance during steady running of the vehicle, the necessary pressure P1 can be reliably stored in the accumulator 58 in a shorter time before the engine 10 is stopped.

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

  In the above-described embodiment, the case where the hydraulic pressure is accumulated in the accumulator 58 in advance during steady running of the vehicle is exemplified. However, the hydraulic pressure is applied to the accumulator 58 only when the stop of the engine 10 is predicted from the deceleration of the vehicle. You may make it accumulate pressure.

  Further, in the above-described embodiment, the case where the normally closed type is adopted as the electromagnetic on-off valve 57 is exemplified, but the normally open type may be adopted as the electromagnetic on-off valve 57.

It is a figure which shows schematic structure of the vehicle drive system which concerns on this 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 process at the time of vehicle steady running by a control part. 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 time chart which shows an example of the behavior of C-1 pressure and Acc pressure.

Explanation of symbols

10 Engine (vehicle drive source)
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 (open / close valve control means, vehicle stop determination means, vehicle stop determination means)
DESCRIPTION OF SYMBOLS 50 Hydraulic circuit 51 Oil pump 52 Line pressure regulator valve 53 Clutch pressure control valve 54 Clutch control valve 55 Shift valve 56 Manual valve 57 Electromagnetic on-off valve 58 Accumulator 59 Hydraulic sensor (hydraulic detection means)
60 Shutoff valve 65 Shift control valve 66 Secondary sheave pressure control valve 70-85 Oil passage C1 Forward clutch (hydraulic servo)
P1 Required pressure

Claims (7)

An oil pump that generates hydraulic pressure;
A hydraulic servo connected to the oil pump via an oil passage and controllable by hydraulic pressure;
An accumulator for storing the hydraulic pressure generated by the oil pump through a branched oil passage branched from the oil passage;
Oil pressure detection means for detecting the oil pressure stored in the accumulator;
An electromagnetic on-off valve that is installed in the branch oil passage, holds the hydraulic pressure of the accumulator while the oil pump is stopped, and supplies the hydraulic servo of the accumulator to the hydraulic servo at the start of driving the oil pump or before driving When,
On-off valve control means for controlling opening and closing of the electromagnetic on-off valve;
Vehicle stop determination means for determining whether or not the vehicle stops,
The on-off valve control means determines that the vehicle stop judgment means determines that the vehicle is to be stopped and the hydraulic pressure detected by the hydraulic pressure detection means has not reached a predetermined value before stopping the vehicle drive source. A vehicle drive device characterized by opening an electromagnetic on-off valve to store hydraulic pressure in the accumulator. The vehicle drive device according to claim 1,
The vehicle drive device according to claim 1, wherein when the hydraulic pressure is stored in the accumulator before the vehicle drive source is stopped, the line pressure of the oil passage is increased. In the vehicle drive device according to claim 1 or 2,
A vehicle drive device characterized in that when the hydraulic pressure is stored in the accumulator before the vehicle drive source is stopped, the rotational speed of the oil pump is increased. In the vehicle drive device according to claim 3,
The oil pump is a mechanical pump that operates in conjunction with the vehicle drive source,
The vehicle drive device according to claim 1, wherein the rotation speed of the oil pump is increased by increasing the rotation speed of the vehicle drive source. In the vehicle drive device according to any one of claims 1 to 4,
The on-off valve control means further opens the electromagnetic on-off valve for a predetermined time and stores hydraulic pressure in the accumulator during steady operation of the vehicle drive source. In the vehicle drive device according to any one of claims 1 to 5,
A vehicle stoppage determining means for determining whether or not the vehicle is stopped,
Even when the vehicle stoppage determining means determines that the vehicle is stopped and the hydraulic pressure detected by the hydraulic pressure detection means has not reached a predetermined value, the electromagnetic opening / closing is stopped before the vehicle drive source is stopped. A vehicular drive device that opens a valve and stores hydraulic pressure in the accumulator. The vehicle drive device according to claim 1,
The vehicle drive device according to claim 1, wherein the electromagnetic on-off valve is a normally closed type that opens when energized and closes when not energized.

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