JP4638362B2 - Engine starter - Google Patents

Description

  The present invention relates to an engine starter that starts an engine capable of driving a load.

  Conventionally, an engine starter configured to start an engine provided in a vehicle by a driving torque of a hydraulic motor has been proposed (for example, Patent Documents 1 and 2 below). The engine starter stores a dedicated electric motor that is driven by being supplied with electric power from a battery provided in the vehicle, a dedicated hydraulic pump that is driven by the electric motor, and a hydraulic pressure that is supplied from the hydraulic pump. An accumulator and a dedicated hydraulic motor that starts the engine by being driven by the hydraulic pressure accumulated in the accumulator are provided.

  Since the engine starter having the above configuration uses the hydraulic pressure stored in the accumulator to start the engine, the engine starter can be used instantly compared to the configuration in which the engine is directly started by the driving torque of the electric motor (cell motor). Work rate can be increased (because hydraulic power density is higher than electricity power density). Therefore, the time until the first explosion of the engine is shortened, and the engine startability is improved.

JP 2001-82202 A JP 2003-148409 A

  The engine starting devices according to Patent Documents 1 and 2 store the kinetic energy of the engine in the battery as electric energy, drive the electric motor using this electric energy, and further drive the hydraulic pump by the driving torque of the electric motor Thus, the energy of the hydraulic oil is stored in the accumulator. That is, after the kinetic energy of the engine is once converted into electric energy, the electric energy is further converted into hydraulic oil energy. Therefore, energy loss increases with these energy conversions, leading to a decrease in energy use efficiency. In addition, when the engine is started by an electric motor, a large current flows instantaneously, so that the burden on the battery and the required performance increase.

  In order to reduce energy loss due to energy conversion, the kinetic energy of the engine (or load) is directly used to drive the hydraulic pump, and the hydraulic oil energy required to start the engine is stored in the accumulator in advance. A configuration is also conceivable in which the number of times of energy conversion required for converting hydraulic oil into energy is reduced. However, in that configuration, load fluctuation occurs due to the drive of the hydraulic pump using the kinetic energy of the engine (or load), and shock due to this load fluctuation occurs. Therefore, it is desirable to reduce the driving torque of the hydraulic pump so that this load fluctuation can be reduced. In order to reduce the size of the hydraulic pump, it is desirable that the driving torque of the hydraulic pump can be reduced. On the other hand, in order to improve the startability of the engine, it is desirable to increase the torque that the hydraulic motor acts on the engine.

  An object of the present invention is to provide an engine starting device that can more appropriately start an engine using the energy of hydraulic oil.

  The engine starter according to the present invention employs the following means in order to achieve the above-described object.

An engine starter according to a reference example of the present invention is an engine starter that starts an engine capable of driving a load, and discharges hydraulic oil using engine power or load power. Hydraulic pressure pump, a pressure accumulator that stores the energy of hydraulic oil discharged from the hydraulic pump, a hydraulic motor that can start the engine by using the energy of hydraulic oil stored in the pressure accumulator, and hydraulic pressure A speed reduction mechanism capable of decelerating the power of the motor and transmitting it to the engine, and allowing the power from the hydraulic motor decelerated by the speed reduction mechanism to be transmitted to the engine and interrupting the power transmission from the engine to the speed reduction mechanism And a one-way power transmission mechanism.

In the reference example of the present invention , when the engine is started using the energy of the hydraulic oil, the number of energy conversions required for the conversion to the hydraulic oil energy can be reduced, and the energy loss caused by the energy conversion can be reduced. Can be reduced. In addition, since the engine is started using the hydraulic pressure having a high output density, the work rate available for starting the engine can be instantaneously increased as compared with the configuration in which the engine is started by the electric motor. And since the torque at the time of starting an engine can be increased by transmitting the motive power of a hydraulic motor to an engine after decelerating with a speed-reduction mechanism, the startability of an engine can be improved more. Furthermore, after the engine is started, power transmission from the engine to the speed reduction mechanism is cut off by the one-way power transmission mechanism, so that drag loss of the one-way power transmission mechanism is reduced when power transmission from the engine to the hydraulic motor is cut off. Can do.

  In one aspect of the present invention, it is preferable to include a power interrupting mechanism that interrupts power between a power transmission path from the engine to a load and the hydraulic pump. In this aspect, it is preferable that the hydraulic pump and the hydraulic motor are constituted by an integrated hydraulic pump motor, and the one-way power interrupting mechanism is arranged in parallel to the power transmission mechanism.

An engine starter according to the present invention is an engine starter that starts an engine capable of driving a load, and sucks and discharges hydraulic oil using engine power or load power. Hydraulic pump motor capable of selectively performing either pump operation or motor operation for starting the engine using hydraulic oil energy, and transfer of hydraulic oil energy to the hydraulic pump motor Is provided in an oil passage for connecting the reservoir and the suction side of the hydraulic pump motor, allows the flow of hydraulic oil from the reservoir to the suction side of the hydraulic pump motor, and sucks the hydraulic pump motor A check valve that shuts off the flow of hydraulic oil from the reservoir to the reservoir, a pressure accumulation state that allows the supply of hydraulic oil energy from the discharge side of the hydraulic pump motor to the pressure accumulator, Switching means capable of switching to a release state allowing the supply of hydraulic oil energy from the installation to the suction side of the hydraulic pump motor, and switching to the pressure accumulation state when the pump operation is performed The switching means that switches to the release state when the motor operation is performed, and the operation that the hydraulic pump motor discharges together with the switching of the switching means to the pressure accumulation state when the hydraulic pump motor performs the pump operation. The gist of the invention is to include a reflux means capable of returning a part of oil to the suction side of the hydraulic pump motor.

  In the present invention, when the hydraulic pump motor performs the pump operation, a part of the hydraulic oil discharged from the hydraulic pump motor is returned to the suction side of the hydraulic pump motor, so that the energy of the hydraulic oil is stored in the pressure accumulator. The drive torque of the hydraulic pump motor can be made smaller than the drive torque of the hydraulic pump motor when starting the engine. Therefore, it is possible to reduce the load fluctuation caused by the pump operation of the hydraulic pump motor, and to quickly start the engine.

In one aspect of the present invention, the recirculation means can recirculate part of the hydraulic oil discharged by the hydraulic pump motor to the suction side of the hydraulic pump motor through the recirculation oil path when the pump operation is performed. In addition, it is preferable that communication between the suction side and the discharge side of the hydraulic pump motor via the reflux oil passage is interrupted when the motor operation is performed. In this aspect, the recirculation means includes a first state in which the suction side and the discharge side of the hydraulic pump motor communicate with each other via the recirculation oil path, and a communication via the recirculation oil path between the suction side and the discharge side of the hydraulic pump motor. It is preferable to include a switching valve that can be switched to a second state that shuts off the valve. In this aspect, it is preferable to alternately switch the switching valve between the first state and the second state when the pump operation is performed. In the aspect of the invention, it is preferable that the recirculation unit includes an adjustment unit that adjusts the recirculation amount of the hydraulic oil from the discharge side to the suction side of the hydraulic pump motor when the pump operation is performed. If it carries out like this, the drive torque of the hydraulic pump motor when storing the energy of hydraulic fluid in a pressure accumulator can be adjusted .

In one aspect of the present invention, the hydraulic pump motor includes first and second pump motors connected in parallel to each other, and in the motor operation, the first and second pump motors use the energy of the hydraulic oil. The engine is started, and in the pump operation, at least the first pump motor uses the power of the engine or the power of the load to suck and discharge the hydraulic oil, and the recirculation means performs the pump operation. It is sometimes possible to return at least part of the hydraulic oil discharged by the second pump motor to the suction side of the second pump motor. In this aspect, the recirculation means recirculates at least a part of the hydraulic oil discharged by the second pump motor to the suction side of the second pump motor through the recirculation oil path when the pump operation is performed. It is possible to cut off the communication between the suction side and the discharge side of the second pump motor through the reflux oil passage when the motor operation is performed. In this aspect, the reflux means includes a first state in which the suction side and the discharge side of the second pump motor communicate with each other via the reflux oil path, and a reflux oil path between the suction side and the discharge side of the second pump motor. It is preferable to include a switching valve that can be switched to the second state in which the communication via the second valve is blocked. In this aspect, it is preferable to alternately switch the switching valve between the first state and the second state when the pump operation is performed. In this aspect, it is preferable that the recirculation means can recirculate all of the hydraulic oil discharged by the second pump motor to the suction side of the second pump motor when the pump operation is performed. It is. If it carries out like this, the drive torque of the hydraulic pump motor when storing the energy of hydraulic oil in a pressure accumulator can be made smaller. In this aspect, it is preferable that the capacity of the second pump motor is set larger than the capacity of the first pump motor. If it carries out like this, while being able to make the drive torque of the hydraulic pump motor when storing the energy of hydraulic oil in a pressure accumulator more smaller, the drive torque of the hydraulic pump motor when starting an engine can be made larger. .

  In one aspect of the present invention, the hydraulic pump motor performs the pump operation when the load is decelerated, and the return means returns a part of the hydraulic oil discharged by the hydraulic pump motor to the suction side of the hydraulic pump motor when the load is decelerated. Is preferable. If it carries out like this, the drive torque of a hydraulic pump motor when storing the energy of hydraulic oil in a pressure accumulator using load energy can be made small.

  In one aspect of the present invention, it is preferable that the hydraulic pump motor performs the pump operation when the operation of the engine is stopped. If it carries out like this, the engine load at the time of stopping operation of an engine can be increased, and operation stop of an engine can be performed rapidly. In this aspect, it is preferable that the recirculation means does not recirculate the hydraulic oil from the discharge side to the suction side of the hydraulic pump motor even when the pump operation is performed when the operation of the engine is stopped. If it carries out like this, the engine load at the time of stopping operation of an engine can be increased more, and operation stop of an engine can be performed more promptly.

An engine starter according to a reference example of the present invention is an engine starter that starts an engine capable of driving a load, and discharges hydraulic oil using engine power or load power. A hydraulic pump capable of storing the pressure, a pressure accumulator that stores the energy of hydraulic oil discharged from the hydraulic pump, and a hydraulic motor that can start the engine using the energy of the hydraulic oil stored in the pressure accumulator It is preferable that the capacity of the hydraulic motor is set larger than the capacity of the hydraulic pump.

In the reference example of the present invention , since the capacity of the hydraulic motor is set larger than the capacity of the hydraulic pump, the engine is started with the driving torque of the hydraulic pump when the hydraulic oil energy is stored in the pressure accumulator. It can be made smaller than the driving torque of the hydraulic motor. Therefore, it is possible to reduce the load fluctuation caused by the pump operation of the hydraulic pump motor, and to quickly start the engine.

  In one aspect of the present invention, it is preferable to include a speed increasing mechanism capable of increasing the speed of power extracted through a power transmission path from an engine to a load and transmitting the speed to a hydraulic pump. If it carries out like this, the drive torque of the hydraulic pump at the time of storing the energy of hydraulic oil in a pressure accumulator can be made smaller, and size reduction of a hydraulic pump can be achieved.

An engine starter according to a reference example of the present invention is an engine starter that starts an engine capable of driving a load, and discharges hydraulic oil using engine power or load power. A hydraulic pump capable of storing the pressure, a pressure accumulator that stores the energy of hydraulic oil discharged from the hydraulic pump, and a hydraulic motor that can start the engine using the energy of the hydraulic oil stored in the pressure accumulator And a speed increasing mechanism capable of speeding up the power extracted through a power transmission path from the engine to the load and transmitting the speed to the hydraulic pump.

In the reference example of the present invention , the hydraulic pressure when the energy of the hydraulic oil is stored in the pressure accumulating device by increasing the power extracted by the power transmission path from the engine to the load by the speed increasing mechanism and transmitting it to the hydraulic pump. The driving torque of the pump can be reduced. As a result, the hydraulic pump can be reduced in size.

  In one aspect of the present invention, a reduction mechanism capable of decelerating and transmitting the power of a hydraulic motor to the engine, and allowing transmission of power from the hydraulic motor decelerated by the reduction mechanism to the engine and from the engine And a one-way power transmission mechanism that interrupts power transmission to the speed reduction mechanism. In this way, when the power transmission from the engine to the hydraulic motor is interrupted after the engine is started, the drag loss of the one-way power transmission mechanism can be reduced.

  ADVANTAGE OF THE INVENTION According to this invention, the engine using the energy of hydraulic oil can be started more appropriately.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as embodiments) will be described with reference to the drawings.

“Embodiment 1”
FIG. 1 is a diagram showing a schematic configuration of a vehicle drive system including an engine starter according to Embodiment 1 of the present invention. An output shaft 10-1 of the engine (internal combustion engine) 10 is connected to a clutch 12, and the power generated by the engine 10 is changed by a transmission (not shown) when the clutch 12 is engaged before driving wheels ( It is used for driving the vehicle by being transmitted to (not shown). As described above, the power generated by the engine 10 is used for driving a load such as driving a vehicle.

  In the present embodiment, in order to improve the fuel efficiency performance of the engine 10, control is performed to automatically stop or restart the engine 10 according to the traveling state of the vehicle. In this embodiment, the engine 10 is automatically restarted using the energy of the hydraulic oil. Hereinafter, a configuration example for that purpose will be described.

  The hydraulic pump motor 22 is rotationally driven by using the power of the engine 10 or the power of the vehicle, thereby sucking the hydraulic oil stored in the reservoir 23 from its inlet 22a and giving energy to the hydraulic oil, and its outlet 22b. It is possible to perform a pump operation for discharging from the pump. Between the output shaft 10-1 of the engine 10 and the rotating shaft of the hydraulic pump motor 22, a transmission mechanism 26 using a belt or the like and a clutch (electromagnetic clutch) 24 as a power interrupting mechanism are provided. . Here, the gear ratio by the transmission mechanism 26 is set to 1. When the clutch 24 is released, power is not transmitted from the output shaft 10-1 of the engine 10 to the rotating shaft of the hydraulic pump motor 22 via the clutch 24. On the other hand, when the clutch 24 is engaged, power is transmitted from the output shaft 10-1 of the engine 10 to the rotating shaft of the hydraulic pump motor 22 via the clutch 24, so that the hydraulic pump motor 22 is driven to rotate. Is done. When the engine 10 generates power for driving the vehicle (driving wheels), a part of the power of the engine 10 is taken out by the output shaft 10-1 of the engine 10 and used as the rotating shaft of the hydraulic pump motor 22. Communicated. Further, when the vehicle is decelerated, a part of the power of the vehicle is taken out by the output shaft 10-1 of the engine 10 and transmitted to the rotating shaft of the hydraulic pump motor 22.

  The accumulator 28 provided as a pressure accumulator can store the energy of the hydraulic oil discharged from the outlet 22b of the hydraulic pump motor 22. The pressure sensor 29 detects the pressure P of the hydraulic oil accumulated in the accumulator 28. A switching valve 30 and a check valve 27 are provided in the oil passage 25 for connecting the outlet 22 b of the hydraulic pump motor 22 and the accumulator 28. The switching valve 30 communicates the outlet 22b of the hydraulic pump motor 22 and the accumulator 28, and disconnects the communication between the outlet 22b of the hydraulic pump motor 22 and the reservoir 23 (the state on the left side in FIG. 1), and hydraulic pressure. A second state (a state on the right side in FIG. 1) in which the outlet 22b of the pump motor 22 and the reservoir 23 are communicated with each other and the communication between the outlet 22b of the hydraulic pump motor 22 and the accumulator 28 is blocked, and an outlet 22b of the hydraulic pump motor 22 It is possible to switch to the third state (the state in the center of FIG. 1) where communication between the accumulator 28 and the reservoir 23 is blocked. The check valve 27 allows the flow of hydraulic oil from the outlet 22 b of the hydraulic pump motor 22 to the accumulator 28 and blocks the flow of hydraulic oil from the accumulator 28 to the outlet 22 b of the hydraulic pump motor 22. The check valve 27 prevents the backflow of hydraulic oil from the accumulator 28 to the outlet 22 b of the hydraulic pump motor 22. Further, the relief valve 31 allows the hydraulic oil in the oil passage 25 to escape to the reservoir 23 when the pressure P of the hydraulic oil in the accumulator 28 (oil passage 25) exceeds the set value P1, so that the accumulator 28 (oil passage 25) The hydraulic oil pressure P is kept below the set value P1.

  The oil passage 33 for connecting the accumulator 28 and the inlet 22a of the hydraulic pump motor 22 is provided with an opening / closing valve 32 for opening and closing the communication between them. When the on-off valve 32 is in the closed state, the supply of hydraulic oil energy from the accumulator 28 to the inlet 22a of the hydraulic pump motor 22 is shut off. On the other hand, when the on-off valve 32 is in the open state, the supply of hydraulic oil energy from the accumulator 28 to the inlet 22a of the hydraulic pump motor 22 is allowed. In this way, the accumulator 28 can transfer hydraulic oil energy to the hydraulic pump motor 22. The hydraulic pump motor 22 generates power using the energy of the hydraulic oil supplied from the accumulator 28 to the inlet 22a, and can perform a motor operation for restarting the engine 10 with this power. The oil passage 35 for connecting the reservoir 23 and the inlet 22 a of the hydraulic pump motor 22 allows the flow of hydraulic oil from the reservoir 23 to the inlet 22 a of the hydraulic pump motor 22 and allows the inlet of the hydraulic pump motor 22. A check valve 37 for blocking the flow of hydraulic oil from 22a to the reservoir 23 is provided. The check valve 37 prevents the backflow of hydraulic oil from the inlet 22 a of the hydraulic pump motor 22 to the reservoir 23.

  Between the rotating shaft of the hydraulic pump motor 22 and the transmission mechanism 26, a speed reduction mechanism 36 and a one-way clutch 34 as a one-way power interrupting mechanism are provided in parallel to the clutch 24. The reduction mechanism 36 can reduce the power of the hydraulic pump motor 22 and transmit it to the transmission mechanism 26 (the output shaft 10-1 of the engine 10). In the deceleration mechanism 36 here, two-stage deceleration is performed. The one-way clutch 34 is provided between the speed reduction mechanism 36 and the transmission mechanism 26 (the output shaft 10-1 of the engine 10). The power from the hydraulic pump motor 22 decelerated by the speed reduction mechanism 36 is output from the engine 10. The transmission to the shaft 10-1 is allowed by the engagement, and the power transmission from the output shaft 10-1 of the engine 10 to the speed reduction mechanism 36 (hydraulic pump motor 22) is cut off by the release (idling).

  The electronic control unit 42 is configured as a microprocessor centered on a CPU, and includes a ROM that stores a processing program, a RAM that temporarily stores data, and an input / output port. The electronic control unit 42 includes a signal indicating an engine rotation speed Ne detected by an engine rotation sensor (not shown), a signal indicating a vehicle speed V detected by a vehicle speed sensor (not shown), and a pressure sensor 29. A signal indicating the pressure P of the accumulator 28 is input through the input port. On the other hand, from the electronic control unit 42, an engine control signal for controlling the operating state of the engine 10, a clutch control signal for performing switching control of release / engagement of the clutch 24, and first to third states of the switching valve 30. A switching control signal for switching the switching and an opening / closing control signal for switching the opening / closing state of the opening / closing valve 32 are output via the output port.

  Next, the operation of the drive system according to the present embodiment, particularly the operation for restarting the engine 10 will be described.

  The electronic control unit 42 controls the switching valve 30 to the first state as shown in FIG. 2 when supplying hydraulic oil to the accumulator 28 by the pumping operation of the hydraulic pump motor 22 (accumulating the accumulator 28). At the same time, the on-off valve 32 is controlled to be closed. That is, a state in which the supply of hydraulic oil energy from the outlet 22b of the hydraulic pump motor 22 to the accumulator 28 is permitted and the supply of hydraulic oil energy from the accumulator 28 to the inlet 22a of the hydraulic pump motor 22 is stopped (pressure accumulation state). To control. Further, as shown in FIG. 2, the electronic control unit 42 engages the clutch 24 to connect the output shaft 10-1 of the engine 10 and the rotating shaft of the hydraulic pump motor 22, thereby The hydraulic pump motor 22 is rotationally driven using the power of the vehicle. By this rotational drive, the hydraulic pump motor 22 can perform a pumping operation in which the hydraulic oil stored in the reservoir 23 is sucked from the inlet 22a, energy is given to the hydraulic oil, and the hydraulic oil is discharged from the outlet 22b. The accumulator 28 can store the energy of the hydraulic oil discharged from the outlet 22b of the hydraulic pump motor 22. Since the gear ratio by the transmission mechanism 26 is 1, the hydraulic pump motor 22 is rotationally driven at the same rotational speed as the engine rotational speed Ne when performing the pump operation. Further, when the pump operation of the hydraulic pump motor 22 is performed, the one-way clutch 34 is released (idling).

  In the present embodiment, the condition for accumulating the accumulator 28 (engaging the clutch 24) can be, for example, when the vehicle is decelerating. By engaging the clutch 24 when the vehicle is decelerating, the hydraulic pump motor 22 can be rotationally driven using the kinetic energy of the vehicle, so that the hydraulic oil energy required for restarting the engine 10 is regenerated energy. Can be stored in the accumulator 28. However, even when the vehicle is not decelerated, the hydraulic pump motor 22 can be driven to rotate by using the power of the engine 10 by engaging the clutch 24. Further, when the pressure P of the accumulator 28 by the pressure sensor 29 is equal to or higher than the set value P1, the electronic control unit 42 determines that the hydraulic oil energy is sufficiently stored in the accumulator 28, and the vehicle is decelerated. Even if it exists, the clutch 24 is not engaged (the hydraulic pump motor 22 is not rotationally driven). The electronic control unit 42 can determine whether or not the vehicle is decelerating based on, for example, the time change rate dV / dt of the vehicle speed V and the brake operation amount B (detected by a sensor (not shown)).

  On the other hand, when restarting the engine 10 that has been stopped by the motor operation of the hydraulic pump motor 22, the electronic control unit 42 keeps the switching valve 30 in the second state with the clutch 24 released as shown in FIG. And the on-off valve 32 is switched to the open state. That is, the state is switched to a state (discharge state) in which the supply of hydraulic oil energy from the accumulator 28 to the inlet 22a of the hydraulic pump motor 22 is allowed and the outlet 22b of the hydraulic pump motor 22 is communicated with the reservoir 23. By switching the switching valve 30 and the opening / closing valve 32, the energy of the hydraulic oil stored in the accumulator 28 is supplied to the inlet 22a of the hydraulic pump motor 22, and the hydraulic pump motor 22 is rotationally driven. When the hydraulic pump motor 22 is driven to rotate, the one-way clutch 34 is engaged, and the power of the hydraulic pump motor 22 is decelerated in two stages by the speed reduction mechanism 36 before being transmitted to the output shaft 10-1 of the engine 10. Thus, the stopped engine 10 is restarted. Thus, when the switching valve 30 is in the second state and the on-off valve 32 is in the open state, the hydraulic pump motor 22 operates as a motor that starts the engine 10 using the energy of the hydraulic oil stored in the accumulator 28. Can be done. After the engine 10 is restarted, the engaged one-way clutch 34 is released, and the transmission mechanism 26 idles. By releasing (idling) the one-way clutch 34, the rotational drive of the hydraulic pump motor 22 by the power of the engine 10 is prevented. At this time, the idling speed of the one-way clutch 34 is equal to the engine speed Ne.

  The electronic control unit 42 controls the clutch 24 to the disengaged state and controls the switching valve 30 to the third state and the on-off valve 32 to the closed state when neither accumulating the accumulator 28 nor restarting the engine 10 is performed. To do. When the engine 10 is rotationally driven in this state, the one-way clutch 34 is released (idling). Further, when the engine 10 is started by a driver's operation, the engine 10 is started by the rotational drive of the starter motor 13.

  In the present embodiment described above, a part of the kinetic energy of the engine 10 or the vehicle is directly converted into hydraulic oil energy by the pumping operation of the hydraulic pump motor 22 and stored in the accumulator 28 in advance. And the engine 10 is restarted by converting the energy of the stored hydraulic oil into the kinetic energy of the hydraulic pump motor 22 by the motor operation of the hydraulic pump motor 22. Thereby, when restarting the engine 10 using the energy of hydraulic oil, the number of times of energy conversion required for conversion of hydraulic oil into energy can be reduced, and energy loss accompanying energy conversion can be reduced. Can do. Therefore, the engine 10 can be restarted efficiently. Further, since the engine 10 is restarted using hydraulic pressure with high output density, it can be used for restarting the engine 10 instantly compared to a configuration in which the engine 10 is restarted by an electric motor (electric starter). Work rate can be increased. Therefore, the time until the first explosion of the engine 10 can be shortened, and the engine 10 can be restarted promptly. As a result, the unburned fuel discharged before the first explosion of the engine 10 can be reduced, and the emission of the engine 10 can be reduced. Furthermore, the engine starter can be reduced in size and mounted.

  In the present embodiment, the hydraulic pump motor 22 is transmitted to the output shaft 10-1 of the engine 10 after the power when the hydraulic pump motor 22 performs the motor operation is decelerated by the speed reduction mechanism 36. Torque that acts on the output shaft 10-1 (torque when the engine 10 is restarted) can be increased. Therefore, the startability of the engine 10 can be further improved. Further, after the engine 10 is restarted, power transmission from the engine 10 to the hydraulic pump motor 22 is interrupted by releasing (idling) the one-way clutch 34, so that the hydraulic pump motor 22 is rotationally driven by the power of the engine 10. (The drag of the hydraulic pump motor 22) can be prevented. Furthermore, by providing the one-way clutch 34 between the speed reduction mechanism 36 and the output shaft 10-1 of the engine 10, the idling speed when the one-way clutch 34 is released can be reduced. As a result, drag loss when the one-way clutch 34 is released can be reduced, and the durability of the one-way clutch 34 can be improved.

  Further, in the present embodiment, when the vehicle is decelerated, the clutch 24 is engaged and the hydraulic pump motor 22 performs the pumping operation, so that the hydraulic oil energy necessary for restarting the engine 10 is converted into the kinetic energy of the vehicle (regeneration). Energy) can be efficiently stored in the accumulator 28. Therefore, restart of the engine 10 using the energy of the hydraulic oil can be performed more efficiently.

  In the present embodiment, the hydraulic pump that performs the pump operation and the hydraulic motor that performs the motor operation are configured by the integrated hydraulic pump motor 22, so that the engine starter can be further downsized and mounted. it can.

  As described above, according to the present embodiment, the restart of the engine 10 using the energy of the hydraulic oil can be performed more appropriately.

  In the above description of the present embodiment, the hydraulic pump that performs the pump operation and the hydraulic motor that performs the motor operation are configured by the integrated hydraulic pump motor 22, and the pump operation and the motor operation of the hydraulic pump motor 22 are performed in a time-sharing manner. It was supposed to be switched. However, in this embodiment, the hydraulic pump that performs the pump operation and the hydraulic motor that performs the motor operation can be separated. When the hydraulic pump and the hydraulic motor are separated, the position for extracting the power transmitted to the hydraulic pump is not limited to the output shaft 10-1 of the engine 10, but the power from the engine 10 to the drive wheels. It is possible to take out power at an arbitrary position in the transmission path and transmit it to the hydraulic pump. In that case, the clutch 24 can perform power interruption between the power transmission path from the engine 10 to the driving wheel and the hydraulic pump.

  In the present embodiment, the switching valve 30 may be capable of switching only to the two states, the first state and the second state described above. In this case, the electronic control unit 42 controls the switching valve 30 to the second state when neither accumulating the accumulator 28 nor restarting the engine 10 is performed.

“Embodiment 2”
FIG. 4 is a diagram showing a schematic configuration of an engine starter according to Embodiment 2 of the present invention. In the following description of the second embodiment, the same or corresponding components as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

  In the present embodiment, rotation of the output shaft 10-1 of the engine 10 and the hydraulic pump motor 22 is performed by switching between disengagement / engagement of a clutch (electromagnetic clutch) 24 disposed inside a transmission mechanism using a belt, a gear, or the like. It is possible to interrupt power with the shaft. Here, the power generated by the motor operation of the hydraulic pump motor 22 is transmitted to the output shaft 10-1 of the engine 10 after being decelerated by the transmission mechanism. That is, in the power transmission from the hydraulic pump motor 22 to the output shaft 10-1 of the engine 10, the transmission mechanism functions as a speed reduction mechanism. Further, as compared with the first embodiment, a reflux oil passage 55 is provided for connecting the inlet 22a (suction side) and the outlet 22b (discharge side) of the hydraulic pump motor 22. Is provided with a switching valve 50 and an orifice (throttle portion) 53. The switching valve 50 communicates the inlet 22a and the outlet 22b of the hydraulic pump motor 22 via the reflux oil passage 55 and at the same time shuts off the communication between the outlet 22b of the hydraulic pump motor 22 and the reservoir 23 (FIG. 4). An upper state), and a second state (a lower state in FIG. 4) in which the outlet 22b of the hydraulic pump motor 22 communicates with the reservoir 23 and the communication between the inlet 22a and the outlet 22b of the hydraulic pump motor 22 is blocked. It is possible to switch to. By switching the switching valve 50 to the first state, the hydraulic oil can be recirculated from the outlet 22b (discharge side) of the hydraulic pump motor 22 to the inlet 22a (suction side) via the reflux oil passage 55. The orifice 53 here is provided for adjusting the flow rate of the hydraulic oil flowing back from the outlet 22b of the hydraulic pump motor 22 to the inlet 22a.

  When accumulating the accumulator 28 by the pumping operation of the hydraulic pump motor 22, the electronic control unit 42 controls the switching valve 50 to the first state and the on-off valve 32 to the closed state as shown in FIG. . That is, a state in which the supply of hydraulic oil energy from the outlet 22b of the hydraulic pump motor 22 to the accumulator 28 is permitted and the supply of hydraulic oil energy from the accumulator 28 to the inlet 22a of the hydraulic pump motor 22 is stopped (pressure accumulation state). In addition, the inlet 22 a and the outlet 22 b of the hydraulic pump motor 22 are communicated with each other through the orifice 53. The electronic control unit 42 engages the clutch 24 and connects the output shaft 10-1 of the engine 10 and the rotating shaft of the hydraulic pump motor 22 to use the power of the engine 10 or the power of the vehicle. The hydraulic pump motor 22 is driven to rotate. By this rotational drive, the hydraulic pump motor 22 can perform a pump operation in which the hydraulic oil stored in the reservoir 23 is sucked from the inlet 22a, energy is given to the hydraulic oil, and the hydraulic oil is discharged from the outlet 22b. Can store the energy of the hydraulic oil discharged from the outlet 22 b of the hydraulic pump motor 22. However, in the present embodiment, when the pump operation of the hydraulic pump motor 22 is performed, the inlet 22a and the outlet 22b of the hydraulic pump motor 22 communicate with each other through the orifice 53, so as shown in FIG. A part of the energy of the hydraulic oil discharged from the outlet 22 b of the hydraulic pump motor 22 is returned to the inlet 22 a (suction side) of the hydraulic pump motor 22 through the orifice 53. Due to the recirculation of the hydraulic oil, the driving torque when the hydraulic pump motor 22 performs the pump operation can be reduced.

  In the present embodiment, as in the first embodiment, as a condition for accumulating the accumulator 28 (engagement of the clutch 24), for example, the vehicle can be decelerated. By engaging the clutch 24 when the vehicle is decelerated, the hydraulic pump motor 22 can be rotationally driven using the kinetic energy of the vehicle. At this time, a part of the motive power of the vehicle is accelerated by a transmission mechanism using a belt, a gear, or the like and then transmitted to the rotating shaft of the hydraulic pump motor 22. That is, in the transmission of power from the output shaft 10-1 of the engine 10 to the hydraulic pump motor 22, the transmission mechanism functions as a speed increasing mechanism.

  On the other hand, when restarting the engine 10 that has been stopped by the motor operation of the hydraulic pump motor 22, the electronic control unit 42 sets the switching valve 50 to the second state with the clutch 24 engaged as shown in FIG. At the same time, the on-off valve 32 is switched to the open state. That is, the state is switched to a state (discharge state) in which the supply of hydraulic oil energy from the accumulator 28 to the inlet 22a of the hydraulic pump motor 22 is allowed and the outlet 22b of the hydraulic pump motor 22 is communicated with the reservoir 23. At this time, the communication between the inlet 22a and the outlet 22b of the hydraulic pump motor 22 via the reflux oil passage 55 is blocked. By switching the switching valve 50 and the opening / closing valve 32, the energy of the hydraulic oil stored in the accumulator 28 is supplied to the inlet 22a of the hydraulic pump motor 22, and the hydraulic pump motor 22 is rotationally driven. When the hydraulic pump motor 22 is rotationally driven, the power of the hydraulic pump motor 22 is decelerated by a transmission mechanism using a belt, a gear, or the like, and then transmitted to the output shaft 10-1 of the engine 10, thereby stopping. The engine 10 is restarted. Thus, when the switching valve 50 is in the second state and the on-off valve 32 is in the open state, the hydraulic pump motor 22 operates as a motor that starts the engine 10 using the energy of the hydraulic oil stored in the accumulator 28. Can be done. For example, when the electronic control unit 42 determines that the engine 10 has restarted based on the engine speed Ne, the electronic control unit 42 releases the clutch 24 that has been engaged, and sets the switching valve 50 in the first state and the on-off valve 32. Switch to the closed state. The electronic control unit 42 controls the clutch 24 to the released state and controls the switching valve 50 to the first state and the on-off valve 32 to the closed state when neither accumulator 28 nor the engine 10 is restarted. To do.

  In the present embodiment described above, when the hydraulic pump motor 22 performs a pump operation, a part of the hydraulic oil discharged from the outlet 22b of the hydraulic pump motor 22 is supplied to the inlet 22a via the reflux oil passage 55 (orifice 53). By returning to the back, the driving torque of the hydraulic pump motor 22 when accumulating the accumulator 28 is accumulated can be reduced. Therefore, it is possible to reduce the load fluctuation due to the hydraulic pump motor 22 performing the pump operation, and to reduce the shock due to the load fluctuation. Furthermore, the driving torque of the hydraulic pump motor 22 can be further reduced by transmitting the power of the engine 10 or the vehicle to the hydraulic pump motor 22 after increasing the speed by the transmission mechanism.

  On the other hand, when the hydraulic pump motor 22 performs the motor operation, the communication between the inlet 22a and the outlet 22b of the hydraulic pump motor 22 via the reflux oil passage 55 is interrupted, and therefore the hydraulic pump when the engine 10 is restarted. The driving torque of the motor 22 can be increased sufficiently. Therefore, the engine 10 can be restarted promptly. Further, by decelerating the power of the hydraulic pump motor 22 with the transmission mechanism and then transmitting it to the output shaft 10-1 of the engine 10, the torque when the engine 10 is restarted can be further increased.

  Further, in the present embodiment, compared to the first embodiment, the one-way clutch 34 can be omitted, and the configuration of the transmission mechanism between the output shaft 10-1 of the engine 10 and the hydraulic pump motor 22 is simplified. can do. As a result, the engine starter can be further reduced in size and mounted.

  Next, another configuration example of this embodiment will be described.

  In the configuration example shown in FIG. 7, the orifice 53 is omitted as compared to the configuration example shown in FIG. Instead of the switching valve 50, a switching valve 51 and an on-off valve 52 are provided. The switching valve 51 communicates the inlet 22a and the outlet 22b of the hydraulic pump motor 22 via the reflux oil passage 55 and at the same time shuts off the communication between the outlet 22b of the hydraulic pump motor 22 and the accumulator 28 (FIG. 7). The second state (FIG. 7) in which the outlet 22b of the hydraulic pump motor 22 and the accumulator 28 are communicated with each other via the check valve 27 and the communication between the inlet 22a and the outlet 22b of the hydraulic pump motor 22 is blocked. It is possible to switch to the lower state). The on-off valve 52 opens and closes communication between the oil passage 25 and the reservoir 23 to open and close communication between the outlet 22b of the hydraulic pump motor 22 and the reservoir 23 when the switching valve 51 is in the second state. Is possible. By switching the switching valve 51 to the first state, the hydraulic oil can be recirculated from the outlet 22b of the hydraulic pump motor 22 to the inlet 22a via the reflux oil passage 55. Further, by switching the switching valve 51 to the second state and the on-off valves 32 and 52 to the closed state, the hydraulic oil energy can be supplied from the outlet 22b of the hydraulic pump motor 22 to the accumulator 28 via the check valve 27. It becomes possible. Further, by switching the switching valve 51 to the second state and the on-off valves 32 and 52 to the open state, the hydraulic oil is supplied from the accumulator 28 to the inlet 22a of the hydraulic pump motor 22, and the outlet 22b of the hydraulic pump motor 22 It is possible to communicate with the reservoir 23. Other configurations are the same as the configuration example shown in FIG.

  When accumulating the accumulator 28 by the pumping operation of the hydraulic pump motor 22, the electronic control unit 42 controls the open / close valves 32 and 52 to be closed and engages the clutch 24 as shown in FIG. 8. The hydraulic pump motor 22 is driven to rotate. Further, the electronic control unit 42 performs duty control that alternately repeats switching of the switching valve 51 between the first state and the second state. By the duty control of the switching valve 51, the distribution of the supply flow rate of hydraulic oil from the outlet 22b of the hydraulic pump motor 22 to the accumulator 28 and the return flow rate of hydraulic oil from the outlet 22b of the hydraulic pump motor 22 to the inlet 22a are controlled. The driving torque when the hydraulic pump motor 22 performs the pump operation can be controlled. For example, by increasing the duty ratio of the switching valve 51 (the ratio at which the switching valve 51 is switched to the first state), it is possible to increase the recirculation flow rate of the hydraulic oil from the outlet 22b of the hydraulic pump motor 22 to the inlet 22a. The driving torque of the pump motor 22 can be reduced. In the configuration example shown in FIG. 7, the condition for accumulating the accumulator 28 can be, for example, when the vehicle is decelerating.

  Further, when stopping the operation of the engine 10, the electronic control unit 42 controls the open / close valves 32 and 52 to be closed and the switching valve 51 to be in the second state. Then, the electronic control unit 42 engages the clutch 24 (connects the engine 10 and the hydraulic pump motor 22), and rotationally drives the hydraulic pump motor 22 using the power of the engine 10 before stopping. The pump operation of the hydraulic pump motor 22 is performed. In that case, the energy of the hydraulic oil discharged from the outlet 22b of the hydraulic pump motor 22 is returned to the inlet 22a via the reflux oil passage 55 because the switching valve 51 is controlled to the second state. Without being supplied to the accumulator 28 via the check valve 27. When the hydraulic pressure is sufficiently stored in the accumulator 28, the hydraulic oil is discharged to the reservoir 23 via the relief valve 31. Therefore, the driving torque (engine load) of the hydraulic pump motor 22 can be increased when the engine 10 is stopped, and the engine 10 can be quickly stopped. Thus, in the pump operation of the hydraulic pump motor 22 during vehicle deceleration, a part of the hydraulic oil discharged from the outlet 22b of the hydraulic pump motor 22 is returned to the inlet 22a, but when the operation of the engine 10 is stopped. The hydraulic oil does not flow back from the outlet 22b of the hydraulic pump motor 22 to the inlet 22a despite the pump operation of the hydraulic pump motor 22.

  Further, when restarting the engine 10 that has been stopped by the motor operation of the hydraulic pump motor 22, the electronic control unit 42 sets the switching valve 51 to the second state with the clutch 24 engaged as shown in FIG. At the same time, the on-off valves 32 and 52 are switched to the open state. By switching the switching valve 51 and the on-off valves 32 and 52, the motor operation of the hydraulic pump motor 22 can be performed as in the configuration example shown in FIG. 4, and the stopped engine 10 can be restarted.

  In the configuration example shown in FIG. 7 as well, it is possible to reduce the driving torque of the hydraulic pump motor 22 when accumulating the accumulator 28 (pump operation) and to reduce the driving torque of the engine 10 (motor operation). The driving torque of the motor 22 can be increased. In the configuration example shown in FIG. 7, the return flow rate of the hydraulic oil from the outlet 22 b to the inlet 22 a of the hydraulic pump motor 22 can be controlled by the duty control of the switching valve 51. Can be omitted. Further, in the configuration example shown in FIG. 7, when the operation of the engine 10 is stopped, the pump operation of the hydraulic pump motor 22 is performed, whereby the engine load can be increased, and the operation of the engine 10 is quickly stopped. Can do. As a result, the ride comfort when the engine 10 is automatically stopped can be improved. Further, when the operation of the engine 10 is stopped, the engine load is further increased by not returning the hydraulic oil from the outlet 22b of the hydraulic pump motor 22 to the inlet 22a despite the pump operation of the hydraulic pump motor 22. The engine 10 can be stopped more quickly.

  In the configuration example shown in FIG. 7, the distribution between the supply flow rate of hydraulic oil from the outlet 22b of the hydraulic pump motor 22 to the accumulator 28 and the return flow rate of hydraulic oil from the outlet 22b of the hydraulic pump motor 22 to the inlet 22a is adjusted. Possible proportional valves can also be provided instead of the switching valve 51. In that case, the electronic control unit 42 drives the proportional valve to distribute the hydraulic oil supply flow rate to the accumulator 28 and the hydraulic oil recirculation flow rate to the inlet 22a of the hydraulic pump motor 22 when accumulating the accumulator 28. It can be controlled by control.

“Embodiment 3”
FIG. 10 is a diagram showing a schematic configuration of an engine starter according to Embodiment 3 of the present invention. In the following description of the third embodiment, the same or corresponding components as those of the first and second embodiments are denoted by the same reference numerals, and redundant description is omitted.

  In the present embodiment, compared to the second embodiment (configuration example shown in FIG. 7), the hydraulic pump motor 22 includes two pump motors 62 and 63 connected in parallel to each other. The capacity of the pump motor 63 is set larger than the capacity of the pump motor 62. The outlet 62 b of the pump motor 62 is connected to the accumulator 28 via the check valve 27, and the outlet 63 b of the pump motor 63 is connected to the switching valve 51. In addition, the capacity | capacitance of a pump motor here represents the volume of the hydraulic oil per rotation of a pump motor.

  The switching valve 51 communicates the inlet 63a and the outlet 63b of the pump motor 62 via the reflux oil passage 55, and also shuts off the communication between the outlet 63b of the pump motor 63 and the accumulator 28 (the upper side in FIG. 10). State), the outlet 63b of the pump motor 63 and the accumulator 28 are communicated via the check valve 27, and the communication between the inlet 63a and the outlet 63b of the pump motor 63 is blocked (on the lower side of FIG. 10). State). The on-off valve 52 can open and close the communication between the outlet 62 b of the pump motor 62 and the reservoir 23. Further, the on-off valve 52 can open and close the communication between the outlet 63b of the pump motor 63 and the reservoir 23 when the switching valve 51 is in the second state. The on-off valve 32 can open and close communication between the accumulator 28 and the inlets 62a and 63a of the pump motors 62 and 63. By switching the switching valve 51 to the first state, the hydraulic oil can be recirculated from the outlet 63b of the pump motor 63 to the inlet 63a via the reflux oil passage 55. Further, by switching the open / close valves 32 and 52 to the closed state, it is possible to supply hydraulic oil energy to the accumulator 28 from the outlet 62b of the pump motor 62 via the check valve 27 (switch to the pressure accumulation state). Become. Further, by switching the switching valve 51 to the second state and the open / close valves 32 and 52 to the open state, the hydraulic oil is supplied from the accumulator 28 to the inlets 62a and 63a of the pump motors 62 and 63, and the pump motors 62 and 63 are supplied. It is possible to communicate the outlets 62b and 63b of the reservoir and the reservoir 23 (switch to the discharge state). In the configuration example shown in FIG. 10, the switching valve 51 and the on-off valve 52 are driven in conjunction with each other, so that the switching valve 51 is switched to the first state and the on-off valve 52 is switched to the closed state. Is switched to the second state, and the on-off valve 52 is switched to the open state.

  When the accumulator 28 is accumulated by the pumping operation of the hydraulic pump motor 22, the electronic control unit 42 controls the open / close valves 32 and 52 and the switching valve 51 to the first state as shown in FIG. The electronic control unit 42 engages the clutch 24 and rotationally drives the pump motors 62 and 63 using the power of the engine 10 or the power of the vehicle, thereby performing the pump operation of the hydraulic pump motor 22. In this pump operation, the pump motor 62 sucks the hydraulic oil stored in the reservoir 23 from the inlet 62a, gives energy to the hydraulic oil, and discharges it from the outlet 62b. The accumulator 28 stores the energy of the hydraulic oil discharged from the outlet 62b of the pump motor 62. On the other hand, in the pump motor 63, since the inlet 63a and the outlet 63b communicate with each other via the reflux oil passage 55, the hydraulic oil discharged from the outlet 63b of the pump motor 63 is as shown in FIG. All are recirculated to the inlet 63a (suction side) through the reflux oil passage 55 as they are. That is, energy is not given to the hydraulic oil in the pump motor 63, and the pump motor 63 does not work as a pump. As a result, the driving torque when the hydraulic pump motor 22 performs the pump operation can be reduced. In the present embodiment, as in the first and second embodiments, as a condition for accumulating the accumulator 28, for example, the vehicle can be decelerated.

  On the other hand, when restarting the engine 10 being stopped by the motor operation of the hydraulic pump motor 22, the electronic control unit 42 opens the on-off valves 32 and 52 with the clutch 24 engaged as shown in FIG. The open state and the switching valve 51 are switched to the second state. By switching the on-off valves 32 and 52 and the switching valve 51, the energy of the hydraulic oil stored in the accumulator 28 is supplied to the inlets 62a and 63a of the pump motors 62 and 63, and the pump motors 62 and 63 are rotationally driven. When the pump motors 62 and 63 are rotationally driven, the power of the pump motors 62 and 63 is decelerated by a transmission mechanism using a belt, a gear, or the like and then transmitted to the output shaft 10-1 of the engine 10 to stop. The engine 10 inside is restarted. As described above, when the on-off valves 32 and 52 are in the open state and the switching valve 51 is in the second state, the pump motors 62 and 63 start the engine 10 using the energy of the hydraulic oil stored in the accumulator 28. Thus, the motor operation of the hydraulic pump motor 22 can be performed. For example, when the electronic control unit 42 determines that the engine 10 has restarted based on the engine rotational speed Ne, the electronic control unit 42 releases the engaged clutch 24, closes the on-off valves 32 and 52, and switches the switching valve 51. Is switched to the first state. The electronic control unit 42 controls the clutch 24 to the released state, closes the on-off valves 32 and 52 and sets the switching valve 51 to the first state when neither accumulator 28 nor the engine 10 is restarted. To control.

  In the present embodiment described above, when the hydraulic pump motor 22 performs a pump operation, all the hydraulic oil discharged from the outlet 63b of the pump motor 63 is returned to the inlet 63a via the reflux oil path 55. The driving torque of the hydraulic pump motor 22 when accumulator 28 is accumulating can be reduced. Therefore, it is possible to reduce the load fluctuation caused by the pump operation of the hydraulic pump motor 22. On the other hand, when the hydraulic pump motor 22 performs motor operation, the communication between the inlet 63a and the outlet 63b of the pump motor 63 via the reflux oil passage 55 is interrupted, and therefore the hydraulic pump motor when the engine 10 is restarted. The driving torque of 22 can be increased sufficiently. Therefore, the engine 10 can be restarted promptly. Furthermore, since the capacity of the pump motor 62 is set to be smaller than the capacity of the pump motor 63, the driving torque of the hydraulic pump motor 22 when accumulating the accumulator 28 can be reduced, and the engine 10 The driving torque of the hydraulic pump motor 22 when restarting can be further increased.

  Further, in the present embodiment, compared with the second embodiment, the orifice 53 of the reflux oil passage 55 can be omitted, and the pressure drop in the reflux oil passage 55 can be eliminated.

  In the present embodiment, as shown in FIG. 13, the drive control of the switching valve 51 and the on-off valve 52 can be performed independently. In the configuration example shown in FIG. 13, when accumulating the accumulator 28 by the pump operation of the hydraulic pump motor 22, the electronic control unit 42 controls the on-off valves 32 and 52 to be closed as shown in FIG. 14. By engaging the clutch 24, the pump motors 62 and 63 are rotationally driven. The energy of the hydraulic oil discharged from the outlet 62 b of the pump motor 62 is stored in the accumulator 28. Further, the electronic control unit 42 performs duty control that alternately repeats switching of the switching valve 51 between the first state and the second state. By controlling the duty of the switching valve 51, distribution of the supply flow rate of hydraulic oil from the outlet 63b of the pump motor 63 to the accumulator 28 and the return flow rate of hydraulic oil from the outlet 63b of the pump motor 63 to the inlet 63a is controlled. The driving torque of the pump motor 63 can be controlled. For example, by increasing the duty ratio of the switching valve 51 (the ratio at which the switching valve 51 is switched to the first state), it is possible to increase the return flow rate of the hydraulic oil from the outlet 63b of the pump motor 63 to the inlet 63a. 63 drive torque can be reduced. In this case, the pump motors 62 and 63 suck the hydraulic oil stored in the reservoir 23 from the inlets 62a and 63a, give the hydraulic oil energy, and discharge the hydraulic oil from the outlets 62b and 63b. In the configuration example shown in FIG. 13, the condition for accumulating the accumulator 28 can be, for example, when the vehicle is decelerating.

  Further, when stopping the operation of the engine 10, the electronic control unit 42 controls the open / close valves 32 and 52 to be closed and the switching valve 51 to be in the second state. Then, the electronic control unit 42 engages the clutch 24 (connects the engine 10 and the pump motors 62 and 63), and rotationally drives the pump motors 62 and 63 using the power of the engine 10 before stopping. Thus, the pump operation of the hydraulic pump motor 22 is performed. In that case, the energy of the hydraulic oil discharged from the outlet 63b of the pump motor 63 is returned to the inlet 63a via the reflux oil passage 55 because the switching valve 51 is controlled to the second state. Instead, it is supplied to the accumulator 28 via the check valve 27. When the hydraulic pressure is sufficiently stored in the accumulator 28, the hydraulic oil is discharged to the reservoir 23 via the relief valve 31. Therefore, the driving torque (engine load) of the hydraulic pump motor 22 can be increased when the engine 10 is stopped, and the engine 10 can be quickly stopped. Thus, in the pump operation of the hydraulic pump motor 22 during vehicle deceleration, a part of the hydraulic oil discharged from the outlet 63b of the pump motor 63 is returned to the inlet 63a, but when the operation of the engine 10 is stopped. The hydraulic oil is not recirculated from the outlet 63b of the pump motor 63 to the inlet 63a in spite of performing the pump operation of the hydraulic pump motor 22.

  Further, when restarting the engine 10 being stopped by the motor operation of the hydraulic pump motor 22, the electronic control unit 42 sets the switching valve 51 to the second state with the clutch 24 engaged as shown in FIG. At the same time, the on-off valves 32 and 52 are switched to the open state. By switching the switching valve 51 and the on-off valves 32 and 52, the motor operation of the hydraulic pump motor 22 can be performed as in the configuration example shown in FIG. 10, and the stopped engine 10 can be restarted.

  In the configuration example shown in FIG. 13 as well, the driving torque of the hydraulic pump motor 22 when accumulating the accumulator 28 (pump operation) can be reduced, and the hydraulic pump when the engine 10 is restarted (motor operation). The driving torque of the motor 22 can be increased. Furthermore, when the operation of the engine 10 is stopped, the engine load can be increased, and the operation of the engine 10 can be stopped quickly.

  In the configuration example shown in FIG. 13 as well, a proportional valve is provided in place of the switching valve 51, and the supply flow rate of hydraulic oil from the outlet 63b of the pump motor 63 to the accumulator 28 and the operation from the outlet 63b of the pump motor 63 to the inlet 63a. A proportional valve capable of adjusting the distribution with the oil recirculation flow rate may be provided instead of the switching valve 51. In that case, when the accumulator 28 is accumulated, the electronic control unit 42 controls the proportional valve drive control of the distribution between the supply flow rate of the hydraulic oil to the accumulator 28 and the return flow rate of the hydraulic oil to the inlet 63a of the pump motor 63. Can be controlled by.

“Embodiment 4”
FIG. 16 is a diagram showing a schematic configuration of an engine starter according to Embodiment 4 of the present invention. In the following description of the fourth embodiment, the same or corresponding components as those in the first to third embodiments are denoted by the same reference numerals, and redundant description is omitted.

  The hydraulic pump 72 is driven to rotate by using the power of the engine 10 or the power of the vehicle, thereby sucking the hydraulic oil stored in the reservoir 23 from its inlet 72a and giving energy to the hydraulic oil, from its outlet 72b. It is possible to perform a pumping operation for discharging. A clutch (electromagnetic clutch) 24 is arranged inside the hydraulic pump 72, and power is interrupted between the output shaft 10-1 of the engine 10 and the hydraulic pump 72 by switching the release / engagement of the clutch 24. Is possible. When the clutch 24 is engaged, the power of the engine 10 or the power of the vehicle is increased by the transmission mechanism 36 and then transmitted to the hydraulic pump 72. That is, in the power transmission from the output shaft 10-1 of the engine 10 to the hydraulic pump 72, the transmission mechanism 36 functions as a speed increasing mechanism.

  The accumulator 28 can store the energy of the hydraulic oil discharged from the outlet 72b of the hydraulic pump 72. The oil passage 25 for connecting the outlet 72b of the hydraulic pump 72 and the accumulator 28 allows the flow of hydraulic oil from the outlet 72b of the hydraulic pump 72 to the accumulator 28 and from the accumulator 28 to the outlet 72b of the hydraulic pump 72. A check valve 27 is provided to block the flow of the hydraulic oil.

  The hydraulic motor 73 connected in parallel with the hydraulic pump 72 generates power using the energy of the hydraulic oil stored in the accumulator 28, and can perform a motor operation to restart the engine 10 with this power. . The capacity of the hydraulic motor 73 (the volume of hydraulic oil required for one rotation of the hydraulic motor 73) is set larger than the capacity of the hydraulic pump 72 (the volume of hydraulic oil discharged by one rotation of the hydraulic pump 72). . The oil passage 33 for connecting the accumulator 28 and the inlet 73a of the hydraulic motor 73 is provided with an opening / closing valve 32 for opening and closing the communication between them. The outlet 73 b of the hydraulic motor 73 is connected to the reservoir 23. The oil passage 35 for connecting the reservoir 23 and the inlet 73a of the hydraulic motor 73 allows the flow of hydraulic oil from the reservoir 23 to the inlet 73a of the hydraulic motor 73, and from the inlet 73a of the hydraulic motor 73 to the reservoir. A check valve 37 that shuts off the flow of hydraulic oil to the engine 23 is provided.

  A one-way clutch 34 is disposed inside the hydraulic motor 73. The one-way clutch 34 allows power transmission from the hydraulic motor 73 to the output shaft 10-1 of the engine 10 by its engagement, and releases power transmission from the output shaft 10-1 of the engine 10 to the hydraulic motor 73 (idling). ). The power of the hydraulic motor 73 is transmitted to the output shaft 10-1 of the engine 10 after being decelerated by the transmission mechanism 36. That is, in the power transmission from the hydraulic motor 73 to the output shaft 10-1 of the engine 10, the transmission mechanism 36 functions as a speed reduction mechanism.

  When accumulating the accumulator 28 by the pumping operation of the hydraulic pump 72, the electronic control unit 42 controls the on-off valve 32 to be closed and engages the clutch 24 as shown in FIG. The hydraulic pump 72 is rotationally driven using power or vehicle power. By this rotational drive, the hydraulic pump 72 can suck the hydraulic oil stored in the reservoir 23 from the inlet 72a, give energy to the hydraulic oil, and discharge the hydraulic oil from the outlet 72b (perform a pump operation). 28 can store the energy of the hydraulic oil discharged from the outlet 72 b of the hydraulic pump 72. At this time, the one-way clutch 34 is released (idling), and the hydraulic motor 73 is not driven to rotate. In the present embodiment, as in the first to third embodiments, as a condition for accumulating the accumulator 28, for example, the vehicle can be decelerated.

  On the other hand, when restarting the stopped engine 10 by the motor operation of the hydraulic motor 73, the electronic control unit 42 switches the on-off valve 32 to the open state with the clutch 24 released, as shown in FIG. When the on-off valve 32 is switched to the open state, the hydraulic oil energy stored in the accumulator 28 is supplied to the inlet 73a of the hydraulic motor 73, and the hydraulic motor 73 is driven to rotate. When the hydraulic motor 73 is driven to rotate, the one-way clutch 34 is engaged, and the power of the hydraulic motor 73 is decelerated by the transmission mechanism 36 and then transmitted to the output shaft 10-1 of the engine 10. The engine 10 is restarted. As described above, when the on-off valve 32 is in the open state, the hydraulic motor 73 can start the engine 10 (perform motor operation) using the energy of the hydraulic oil stored in the accumulator 28. . After the engine 10 is restarted, the engaged one-way clutch 34 is released. By releasing the one-way clutch 34, the rotational drive of the hydraulic motor 73 by the power of the engine 10 is prevented. The electronic control unit 42 controls the clutch 24 to be in the disengaged state and the on-off valve 32 to be in the closed state when neither accumulating the accumulator 28 nor restarting the engine 10 is performed.

  In the present embodiment described above, since the capacity of the hydraulic pump 72 is set to be smaller than the capacity of the hydraulic motor 73, the driving torque of the hydraulic pump 72 when accumulating the accumulator 28 can be reduced. The driving torque of the hydraulic motor 73 when the engine 10 is restarted can be increased. Therefore, it is possible to reduce the load fluctuation due to the rotational drive of the hydraulic pump 72 and to restart the engine 10 promptly. Furthermore, the driving torque of the hydraulic pump 72 can be further reduced by transmitting the power of the engine 10 or the vehicle to the hydraulic pump 72 after being accelerated by the transmission mechanism 36. Furthermore, the torque when the engine 10 is restarted can be further increased by transmitting the power of the hydraulic motor 73 to the output shaft 10-1 of the engine 10 after decelerating the power of the hydraulic motor 73.

  In the present embodiment, by reducing the driving torque of the hydraulic pump 72, the hydraulic pump 72 can be reduced in size and the mountability can be improved. Furthermore, the torque capacity of the clutch 24 can be reduced, and the clutch 24 can be downsized and mounted. Further, by incorporating the clutch 24 and the one-way clutch 34 into the hydraulic pump 72 and the hydraulic motor 73, respectively, the engine starter can be further reduced in size and mounted. Further, in the present embodiment, the configuration of the hydraulic system can be simplified as compared with the second and third embodiments.

  Next, another configuration example of this embodiment will be described.

  In the configuration example shown in FIG. 19, power is transmitted from the hydraulic motor 73 to the output shaft 10-1 of the engine 10 via the transmission mechanism 36, and power is transmitted from the output shaft 10-1 of the engine 10 to the hydraulic pump 72. Is performed via a transmission mechanism 26 that is separate from the transmission mechanism 36. The transmission mechanism 36 is a reduction mechanism capable of decelerating the power of the hydraulic motor 73 and transmitting it to the output shaft 10-1 of the engine 10. The transmission mechanism 26 increases the power of the engine 10 or the power of the vehicle. Thus, the speed increasing mechanism can be transmitted to the hydraulic pump 72. According to the configuration example shown in FIG. 19, the transmission ratio when the power is transmitted from the output shaft 10-1 of the engine 10 to the hydraulic pump 72 (the transmission ratio of the transmission mechanism 26), and the output shaft of the engine 10 from the hydraulic motor 73. The transmission gear ratio (transmission gear ratio of the transmission mechanism 36) when power is transmitted to 10-1 can be set independently. Therefore, the driving torque of the hydraulic pump 72 when accumulating the accumulator 28 and the torque when restarting the engine 10 can be set more appropriately.

  Further, in the configuration example shown in FIG. 20, the transmission that can reduce the power of the hydraulic motor 73 and transmit it to the output shaft 10-1 of the engine 10 by meshing the pinion gear 36 b with the outside of the flywheel 36 a. A mechanism (deceleration mechanism) 36 is configured, and the one-way clutch 34 is disposed inside the flywheel 36a. The one-way clutch 34 here allows transmission of the power from the hydraulic motor 73 decelerated by the reduction mechanism 36 to the output shaft 10-1 of the engine 10 by its engagement, and the output shaft 10-1 of the engine 10 Power transmission to the speed reduction mechanism 36 (hydraulic motor 73) is cut off by its release (idling). Between the output shaft 10-1 of the engine 10 (auxiliary side opposite to the flywheel 36a) and the hydraulic pump 72, there is a transmission mechanism 26 using a belt or the like, and a clutch (electromagnetic clutch) 24. Is provided. Here, the transmission mechanism 26 is a speed increasing mechanism capable of increasing the speed of the power of the engine 10 or the power of the vehicle and transmitting it to the hydraulic pump 72. In the configuration example shown in FIG. 20, the capacity of the hydraulic motor 73 is set larger than the capacity of the hydraulic pump 72. Also in the configuration example shown in FIG. 20, when accumulating the accumulator 28, the on-off valve 32 is controlled to be closed and the clutch 24 is engaged. When restarting the stopped engine 10, the on-off valve 32 is switched to the open state with the clutch 24 released.

  According to the configuration example shown in FIG. 20, the diameter ratio between the flywheel 36a and the pinion gear 36b can be increased. Therefore, even when the capacity of the hydraulic motor 73 is reduced, the torque when the engine 10 is restarted is reduced. It can be secured sufficiently. Further, by incorporating the one-way clutch 34 inside the flywheel 36a, the engine starter can be further reduced in size and mounted. Furthermore, the idling speed when the one-way clutch 34 is released can be reduced, and drag loss when the one-way clutch 34 is released can be reduced. Moreover, the mounting performance of the hydraulic pump 72 and the hydraulic motor 73 can be improved by disposing the hydraulic pump 72 and the hydraulic motor 73 on opposite sides of the engine 10.

  In the configuration examples shown in FIGS. 19 and 20, the position at which the power transmitted to the hydraulic pump 72 is extracted is not limited to the output shaft 10-1 of the engine 10, but the power transmission path from the engine 10 to the drive wheels is not limited. It is possible to take out power at an arbitrary position and transmit it to the hydraulic pump 72. In that case, the clutch 24 can perform power interruption between the hydraulic pump 72 and the power transmission path from the engine 10 to the driving wheel, and the transmission mechanism (speed increasing mechanism) 26 is driven from the engine 10. It is possible to increase the power extracted through the power transmission path leading to the wheel and transmit it to the hydraulic pump 72.

  In the above description of each embodiment, the hydraulic pump motor 22 (or the hydraulic pump 72) is driven to rotate by utilizing the kinetic energy of the vehicle by engaging the clutch 24 when the vehicle is decelerated. However, in this embodiment, the hydraulic pump motor 22 (or the hydraulic pump 72) can be driven to rotate by engaging the clutch 24 even when the vehicle is not decelerated. For example, when the pressure P of the accumulator 28 is lower than a set value P2 (P2 <P1), the clutch 24 is engaged and the hydraulic pump motor 22 (or the hydraulic pump 72) is driven to rotate using the power of the engine 10. It is also possible.

  In each embodiment, instead of the pressure sensor 29, a pressure switch that outputs a signal corresponding to the pressure of the hydraulic oil accumulated in the accumulator 28 can be provided. For example, the pressure switch outputs an H (high) level signal when the pressure of the accumulator 28 is equal to or higher than a set value, and outputs an L (low) level signal when the pressure of the accumulator 28 is lower than the set value. can do.

  As mentioned above, although the form for implementing this invention was demonstrated, this invention is not limited to such embodiment at all, and it can implement with a various form in the range which does not deviate from the summary of this invention. Of course.

1 is a diagram showing a schematic configuration of a vehicle drive system including an engine starter according to Embodiment 1 of the present invention. It is a figure explaining operation | movement of the engine starting apparatus which concerns on Embodiment 1 of this invention. It is a figure explaining operation | movement of the engine starting apparatus which concerns on Embodiment 1 of this invention. It is a figure which shows schematic structure of the engine starting apparatus which concerns on Embodiment 2 of this invention. It is a figure explaining operation | movement of the engine starting apparatus which concerns on Embodiment 2 of this invention. It is a figure explaining operation | movement of the engine starting apparatus which concerns on Embodiment 2 of this invention. It is a figure which shows the other schematic structure of the engine starting apparatus which concerns on Embodiment 2 of this invention. It is a figure explaining other operation | movement of the engine starting apparatus which concerns on Embodiment 2 of this invention. It is a figure explaining other operation | movement of the engine starting apparatus which concerns on Embodiment 2 of this invention. It is a figure which shows schematic structure of the engine starting apparatus which concerns on Embodiment 3 of this invention. It is a figure explaining operation | movement of the engine starting apparatus which concerns on Embodiment 3 of this invention. It is a figure explaining operation | movement of the engine starting apparatus which concerns on Embodiment 3 of this invention. It is a figure which shows the other schematic structure of the engine starting apparatus which concerns on Embodiment 3 of this invention. It is a figure explaining other operation | movement of the engine starting apparatus which concerns on Embodiment 3 of this invention. It is a figure explaining other operation | movement of the engine starting apparatus which concerns on Embodiment 3 of this invention. It is a figure which shows schematic structure of the engine starting apparatus which concerns on Embodiment 4 of this invention. It is a figure explaining operation | movement of the engine starting apparatus which concerns on Embodiment 4 of this invention. It is a figure explaining operation | movement of the engine starting apparatus which concerns on Embodiment 4 of this invention. It is a figure which shows the other schematic structure of the engine starting apparatus which concerns on Embodiment 4 of this invention. It is a figure which shows the other schematic structure of the engine starting apparatus which concerns on Embodiment 4 of this invention.

Explanation of symbols

  10 engine, 12, 24 clutch, 22 hydraulic pump motor, 26 transmission mechanism (speed increasing mechanism), 27, 37 check valve, 28 accumulator, 29 pressure sensor, 30, 50, 51 switching valve, 32, 52 on-off valve, 34 one-way clutch, 36 transmission mechanism (deceleration mechanism), 42 electronic control unit, 53 orifice, 55 reflux oil passage, 62, 63 pump motor, 72 hydraulic pump, 73 hydraulic motor.

Claims (14)

An engine starter for starting an engine capable of driving a load,
A pump operation that sucks and discharges hydraulic oil using engine power or load power and a motor operation that starts the engine using hydraulic oil energy can be selectively performed. Possible hydraulic pump motor,
A pressure accumulator for transferring hydraulic oil energy to the hydraulic pump motor;
The hydraulic fluid is provided in an oil passage for connecting the reservoir and the suction side of the hydraulic pump motor, allows the hydraulic oil to flow from the reservoir to the suction side of the hydraulic pump motor, and operates from the suction side of the hydraulic pump motor to the reservoir. A check valve that shuts off the flow of
The pressure accumulation state allows the supply of hydraulic oil energy from the discharge side of the hydraulic pump motor to the pressure accumulator, and the release state permits the supply of hydraulic oil energy from the pressure accumulation device to the suction side of the hydraulic pump motor. Switching means capable of switching, switching means to switch to the pressure accumulation state when the pump operation is performed, and switching to the discharge state when the motor operation is performed;
When the hydraulic pump motor performs the pump operation, the switching means switches to the accumulated pressure state, and a part of the hydraulic oil discharged by the hydraulic pump motor can be returned to the suction side of the hydraulic pump motor. Means,
An engine starting device comprising: The engine starting device according to claim 1,
The recirculation means can recirculate part of the hydraulic oil discharged by the hydraulic pump motor to the suction side of the hydraulic pump motor through the recirculation oil path when the pump operation is performed. An engine starter characterized in that communication between the suction side and the discharge side of the hydraulic pump motor through the reflux oil passage is interrupted when The engine starting device according to claim 2,
The recirculation means is configured to block the first state in which the suction side and the discharge side of the hydraulic pump motor are communicated with each other via the recirculation oil passage, and the communication between the suction side and the discharge side of the hydraulic pump motor via the recirculation oil passage. An engine starter comprising a switching valve capable of switching between two states. The engine starter according to claim 3, wherein
An engine starter characterized by alternately switching the switching valve between the first state and the second state when the pump operation is performed. The engine starter according to any one of claims 1 to 3,
The recirculation means includes an adjusting means for adjusting a recirculation amount of the hydraulic oil from the discharge side to the suction side of the hydraulic pump motor when the pump operation is performed. The engine starting device according to claim 1,
The hydraulic pump motor includes first and second pump motors connected in parallel to each other,
In the motor operation, the first and second pump motors start the engine using the energy of the hydraulic oil,
In the pump operation, at least the first pump motor uses the power of the engine or the power of the load to suck and discharge the hydraulic oil,
The recirculation means can recirculate at least a part of the hydraulic oil discharged by the second pump motor to the suction side of the second pump motor when the pump operation is performed. apparatus. The engine starter according to claim 6, wherein
The return means can return at least a part of the hydraulic oil discharged by the second pump motor to the suction side of the second pump motor through the return oil path when the pump operation is performed, An engine starter characterized in that communication between the suction side and the discharge side of the second pump motor through the reflux oil passage is interrupted when the motor operation is performed. The engine starting device according to claim 7,
The recirculation means includes a first state in which the suction side and the discharge side of the second pump motor communicate with each other via the reflux oil path, and a communication via the reflux oil path between the suction side and the discharge side of the second pump motor. An engine starter comprising a switching valve that can be switched to a second state that shuts off the engine. The engine starter according to claim 8, wherein
An engine starter characterized by alternately switching the switching valve between the first state and the second state when the pump operation is performed. The engine starting device according to any one of claims 6 to 8,
The engine starter characterized in that the recirculation means can recirculate all of the hydraulic oil discharged by the second pump motor to the suction side of the second pump motor when the pump operation is performed. The engine starter according to any one of claims 6 to 10,
An engine starter characterized in that the capacity of the second pump motor is set larger than the capacity of the first pump motor. The engine starter according to any one of claims 1 to 11,
The hydraulic pump motor performs the pump operation when the load is decelerated,
The recirculation means recirculates part of the hydraulic oil discharged from the hydraulic pump motor to the suction side of the hydraulic pump motor when the load is decelerated. The engine starter according to any one of claims 1 to 12,
The hydraulic pump motor performs the pump operation when the operation of the engine is stopped. The engine starting device according to claim 13,
The recirculation means prevents the working oil from recirculating from the discharge side to the suction side of the hydraulic pump motor even when the pump operation is performed when the operation of the engine is stopped.

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