JP2017066998A - Regeneration system for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smoothly increase engine speed even after switching from hydraulic traveling to engine traveling, to improve start acceleration performance, and to improve drivability.SOLUTION: A low pressure reservoir (10) includes a reservoir vessel (22), and a piston (23) arranged in an inside of the reservoir vessel (22) to be freely slidable, and the piston (23) divides the inside of the reservoir vessel (22) into an oil chamber (24) storing oil and a gas chamber (25) storing air in a sliding direction, and the gas chamber (25) of the low pressure reservoir (10) is connected to an intake passage (12) of an engine (1). A control device (11) is further provided for performing supercharge control for increasing a pressure in the intake passage (12) by supplying the air in the gas chamber (25) of the low pressure reservoir (10) to the intake passage (12) during power running operation.SELECTED DRAWING: Figure 1

Description

  The technology disclosed herein relates to a regenerative system for a vehicle including a high pressure accumulator that stores oil under pressure and a low pressure reservoir.

  Conventionally, as this type of regeneration system, a regeneration system including an oil pump motor having both functions of an oil pump and a hydraulic motor is known. The high pressure accumulator and the low pressure reservoir are connected via an oil pump motor. The high pressure accumulator stores oil pressurized to high pressure, and the low pressure reservoir stores oil pressurized to low pressure.

  In this regenerative system, the power of the drive wheels is input to the oil pump motor when decelerating during downhill traveling or the like. Thereby, the oil pump motor is driven as an oil pump, and the oil in the low pressure reservoir is sent to the high pressure accumulator. As a result, the internal pressure of the high pressure accumulator rises, and the oil pressurized to a higher pressure is accumulated in the high pressure accumulator (deceleration regeneration).

  In addition, when the vehicle starts, oil from the high pressure accumulator flows out toward the low pressure reservoir. The oil pump motor is driven as a hydraulic motor by the discharge pressure of oil from the high pressure accumulator, and the power is output to the drive wheels (powering). As a result, the vehicle is hydraulically driven. And the oil which flowed out from the high pressure accumulator is collected in the low pressure reservoir.

  An example of such a regeneration system is disclosed in Patent Document 1, for example.

Japanese Patent Laid-Open No. 10-244858

  However, in the regenerative system described above, the size of the high-pressure accumulator and the low-pressure reservoir is limited in consideration of the mountability in the vehicle, so that there is a limit to the amount of energy that can be regenerated. For this reason, even if power running is performed at the time of starting of the vehicle or the like, before the engine speed becomes sufficiently high, the oil in the high-pressure accumulator may flow out and switch from hydraulic travel to engine travel. In such a case, a feeling of acceleration is generated, the acceleration performance of the start is poor, and the driving performance (drivability) is not good because the driver feels uncomfortable.

  The technology disclosed herein has been made in view of such a point, and the purpose of the technology is to make it possible to smoothly increase the engine speed even after switching from hydraulic traveling to engine traveling. It is to improve acceleration performance and improve drivability.

  In order to achieve the above object, in the technique disclosed herein, the air stored in the low pressure reservoir is used for supercharging the engine.

  Specifically, the technology disclosed herein is directed to a vehicle regeneration system including a high pressure accumulator that stores oil under pressure and a low pressure reservoir. The low pressure reservoir has a container and a piston slidably disposed inside the container. The piston partitions the interior of the container into an oil chamber in which oil is stored and a gas chamber in which air is stored in the sliding direction. The gas chamber of the low pressure reservoir is connected to the intake path of the engine. The regenerative system further includes a control device that performs supercharging control for increasing the pressure in the intake passage by supplying air in the gas chamber of the low-pressure reservoir to the intake passage of the engine during powering.

  According to this configuration, the air in the gas chamber of the low-pressure reservoir is supplied to the intake passage and the air stored in the low-pressure reservoir is used for supercharging the engine when the vehicle is powered, for example, during acceleration such as starting. Even after the oil in the high pressure accumulator has completely flowed out and switched from hydraulic travel to engine travel, the engine speed can be increased smoothly due to the supercharging effect. As a result, it is possible to improve the acceleration performance by suppressing the occurrence of rattling in acceleration, and to improve driving performance by reducing the uncomfortable feeling given to the driver.

  In the above regeneration system, the supercharging path that connects the gas chamber of the low pressure reservoir and the intake path is provided with an adjustment valve that adjusts the supply flow rate of air supplied from the gas chamber of the low pressure reservoir to the intake path, In supercharging control, it is preferable to adjust the supply flow rate of air to the intake path by adjusting the opening of the adjustment valve based on the accelerator opening and the engine speed.

  According to this configuration, since the supply flow rate of air used for supercharging is adjusted based on the accelerator opening and the engine speed, the torque required for the engine (hereinafter referred to as “required torque”) is stored in the low-pressure reservoir. Can be supplied to the intake passage at a flow rate necessary to realize “ In other words, the supply flow rate of air supplied from the low-pressure reservoir to the intake path during execution of supercharging control increases as the required torque increases, and conversely decreases as it decreases. Thereby, acceleration performance (acceleration response) commensurate with the travel request can be obtained.

  In addition, each time the supercharging control described above is repeated, the air in the gas chamber of the low-pressure reservoir is supplied to the intake path, so that the air in the gas chamber decreases and the gas chamber in the low-pressure reservoir is reduced. The pressure buffering function is impaired, and eventually, air cannot be supplied to the intake passage. Therefore, in the above regeneration system, it is necessary to replenish the gas chamber of the low-pressure reservoir with the air that has decreased with the execution of the supercharging control.

  In order to supply air to the gas chamber of the low-pressure reservoir, it is preferable to use the engine as a compression pump and supply exhaust gas compressed in the exhaust stroke to the gas chamber. Specifically, the gas chamber of the low-pressure reservoir is also connected to the exhaust path of the engine, and the control device drives the engine by the rotation of the drive wheel during deceleration regeneration, and from the exhaust path by driving the engine. It is preferable to execute replenishment control for supplying the exhaust compressed in the exhaust stroke to the gas chamber of the low-pressure reservoir.

  According to this configuration, exhaust gas compressed in the exhaust stroke is supplied to the gas chamber of the low-pressure reservoir in which air has decreased due to execution of supercharging control, so that the pressure buffering function of the gas chamber is prevented from being impaired. be able to. Further, when the engine does not perform the combustion stroke, that is, when the air taken into the engine from the intake path is discharged as exhaust into the exhaust path as it is, the replenishment control is performed, or the oxygen in the gas chamber is performed after the replenishment control is performed. If the concentration is adjusted, it is possible to prevent a situation where air cannot be supplied to the intake path in the supercharging control.

  In addition, according to the above configuration, since the engine is driven by the rotation of the drive wheels, the engine brake can be applied and the engine can function as a compression pump. As a result, the exhaust can be sent to the low-pressure reservoir without providing a separate dedicated compression pump, and the cost increase can be suppressed.

  Furthermore, it is preferable that the control device executes replenishment control when the engine deceleration fuel is cut.

  When high-temperature exhaust gas burned by the engine is introduced into the gas chamber of the low-pressure reservoir, there is a concern that the exhaust heat may adversely affect the low-pressure reservoir. Since the oxygen concentration of the air supplied to the path becomes thin, a desired supercharging effect cannot be expected, and a means for adjusting the oxygen concentration is required separately. However, at the time of deceleration fuel cut, the combustion stroke is not performed in the engine, and the air sucked into the engine is circulated through the exhaust path at a relatively low temperature as exhaust without being combusted.

  According to the above configuration, the uncombusted exhaust when the deceleration fuel is cut, that is, the relatively low temperature air sucked into the engine is replenished to the gas chamber of the low pressure reservoir. In addition, the oxygen concentration of the air in the gas chamber of the low-pressure reservoir can be maintained, and a desired supercharging effect can be obtained during the supercharging control.

  In addition, a catalyst device for purifying harmful components in the exhaust is generally provided in the exhaust path. In this case, the gas chamber of the low-pressure reservoir is preferably connected to the exhaust path on the upstream side of the catalyst device.

  The catalyst device needs to be raised to a temperature at which the catalyst held therein becomes an active state in order to sufficiently exhibit the exhaust gas purification performance. However, when the fuel is decelerated, unburned exhaust (air) flows through the catalyst device, so the catalyst is likely to be cooled and inactivated due to the relatively low temperature exhaust.

  On the other hand, according to the above configuration, the relatively low temperature exhaust gas at the time of the deceleration fuel cut is supplied to the gas chamber of the low pressure reservoir from the exhaust path upstream of the catalyst device. It is possible to reduce the flow rate of the exhaust gas flowing through the exhaust gas, thereby suppressing the catalyst from being cooled to an inactive state.

  According to the above regenerative system, the engine speed can be increased smoothly even after switching from the hydraulic travel to the engine travel, and the start acceleration performance can be improved and the drivability can be improved.

It is a conceptual diagram which shows the regeneration system of a vehicle. It is a conceptual diagram which shows the state at the time of the deceleration regeneration in the regeneration control of a vehicle. It is a conceptual diagram which shows the state at the time of the power running in the regeneration control of a vehicle. It is a conceptual diagram which shows operation | movement of the main structure of the regeneration system of a vehicle. It is a conceptual diagram which shows operation | movement of the main structure of the regeneration system of a vehicle. It is a conceptual diagram which shows operation | movement of the main structure of the regeneration system of a vehicle. It is a flowchart figure which shows an example of control of the regeneration system of a vehicle. It is a flowchart figure which shows an example of control of the regeneration system of a vehicle.

  Hereinafter, exemplary embodiments will be described in detail with reference to the drawings.

−Regenerative system configuration−
FIG. 1 shows an example of an automobile C as a vehicle using the regeneration system ERS.

  As shown in FIG. 1, the regenerative system ERS includes an engine 1, a first clutch 2, a transmission 3, a differential gear 4, a drive wheel 5, a coupling mechanism 6, a second clutch 7, an oil pump motor 8, a high pressure accumulator 9, A low-pressure reservoir 10 and a control device 11 are included.

  The engine 1 is, for example, a reciprocating engine. A throttle 13 is installed in the intake path 12 of the engine 1. A first switching valve 15, a catalyst device 16, and a muffler 17 are installed in the exhaust path 14 of the engine 1 in order from the upstream side. The output shaft of the engine 1 is connected to the drive wheels 5 via the first clutch 2, the transmission 3 and the differential gear 4. FIG. 1 shows a state where the vehicle is running with the engine 1 as a power source, and the drive wheels 5 are rotationally driven by the engine 1.

  The catalyst device 16 is, for example, an electrically heated catalyst device, and has an exhaust purification function capable of purifying air pollutants such as NOx (nitrogen oxide), CO (carbon monoxide), and HC (hydrocarbon). It has a catalyst inside. The exhaust purification performance of the catalyst is satisfactorily exhibited in an active state when the catalyst is at a predetermined temperature or higher.

  The oil pump motor 8 is a device that functions as one of an oil pump and a hydraulic motor, and has a first oil inlet / outlet 8a and a second oil inlet / outlet 8b that function as either an oil discharge port or a suction port. . As shown in FIG. 1, the rotation shaft of the oil pump motor 8 is connected to the output shaft to the drive wheels 5 via the second clutch 7 and the connection mechanism 6. In FIG. 1, the second clutch 7 is in a disengaged state.

  When the oil pump motor 8 functions as an oil pump, the first oil inlet / outlet 8a functions as a discharge port, and the second oil inlet / outlet 8b functions as a suction port (see FIG. 2). When the oil pump motor 8 functions as a hydraulic motor, the first oil inlet / outlet 8a functions as a suction port and the second oil inlet / outlet 8b functions as a discharge port (see FIG. 3).

  The high pressure accumulator 9 includes a pressure accumulating container 18 having pressure resistance and a piston 19 slidably disposed in the pressure accumulating container 18. The interior of the pressure accumulating vessel 18 is partitioned into an oil chamber 20 and a gas chamber 21 in a sliding direction by a piston 19. In the gas chamber 21, for example, high-pressure air having a level of 200 to 400 atmospheres is stored. The oil chamber 20 stores oil pressurized at the same atmospheric pressure level as the air in the gas chamber 21.

  The low pressure reservoir 10 includes a pressure resistant reservoir container 22 and a piston 23 slidably disposed inside the reservoir container 22. The interior of the reservoir container 22 is partitioned into an oil chamber 24 and a gas chamber 25 in the sliding direction by a piston 23. In the gas chamber 25, for example, low-pressure air having a level of 10 to 30 atm is stored. The oil chamber 24 stores oil pressurized at the same atmospheric pressure level as the air in the gas chamber 25.

  The oil chambers 20 and 24 of the high pressure accumulator 9 and the low pressure reservoir 10 are connected to the oil pump motor 8, and are connected via the oil pump motor 8.

  Specifically, the high pressure accumulator 9 and the low pressure reservoir 10 are provided with oil outlets 9a and 10a. The oil outlets 9 a and 10 a communicate with the oil chambers 20 and 24 and are openings through which oil enters and exits the oil chambers 20 and 24. The oil inlet / outlet port 9a of the high pressure accumulator 9 is connected to the first oil inlet / outlet port 8a of the oil pump motor 8 via an oil path. On the other hand, the oil inlet / outlet port 10a of the low-pressure reservoir 10 is connected to the second oil inlet / outlet port 8b of the oil pump motor 8 through an oil path.

  On-off valves 26 and 27 are provided at the oil inlets 9 a and 10 a of the high-pressure accumulator 9 and the low-pressure reservoir 10, respectively. The open / close valves 26 and 27 of the oil outlets 9a and 10a allow the oil chambers 20 and 24 and the oil pump motor 8 to communicate with each other when in the open state. These on-off valves 26 and 27 are normally closed.

  The oil stored in the oil chambers 20 and 24 of the high-pressure accumulator 9 and the low-pressure reservoir 10 goes back and forth between them by driving the oil pump motor 8. Therefore, the amount of oil stored in both the oil chambers 20 and 24 changes according to the operation of the oil pump motor 8. The volumes of the gas chambers 21 and 25 of the high pressure accumulator 9 and the low pressure reservoir 10 change according to the amount of oil stored in the oil chambers 20 and 24.

  That is, in the high pressure accumulator 9 and the low pressure reservoir 10, when oil flows into the oil chambers 20, 24, the pistons 19, 23 are moved to the gas chambers 21, 25 side (in a direction away from the oil inlets / outlets 9a, 10a). The volume of the oil chambers 20, 24 is increased by the sliding of the pistons 19, 23, and the volume of the gas chambers 21, 25 is decreased accordingly. Further, when the oil flows out from the oil chambers 20 and 24, the pistons 19 and 23 slide toward the oil chambers 20 and 24 (in the direction approaching the oil inlets 9a and 10a) along with the outflow, and the sliding of the pistons 19 and 23 occurs. As a result, the volumes of the oil chambers 20 and 24 are reduced, and the volumes of the gas chambers 21 and 25 are increased accordingly.

  The gas chamber 22 of the low-pressure reservoir 10 is connected to the intake path 12 and the exhaust path 14 of the engine 1, respectively, and can be switched between a state communicating with the intake path 12 and a state communicating with the exhaust path 14. Yes.

  Specifically, the low pressure reservoir 10 is provided with a gas inlet / outlet port 10b. The gas inlet / outlet port 10 b communicates with the gas chamber 25 of the low-pressure reservoir 10, is an opening through which air enters and exits the gas chamber 25, and is connected to the air flow passage 28. An open / close valve 29 is also provided at the gas inlet / outlet 10b. The open / close valve 29 of the gas inlet / outlet port 10b allows the gas chamber 25 of the low pressure reservoir 10 and the air flow passage 28 to communicate with each other when in the open state. The on-off valve 29 is normally closed.

  The air flow passage 28 is branched into a supercharging path 30 and a supply path 31. The supercharging path 30 is connected to the intake path 12 and is a supercharging use path through which air supplied from the gas chamber 25 of the low-pressure reservoir 10 to the intake path 12 flows. The replenishment path 31 branches from the exhaust path 14 on the upstream side of the catalyst device 16, and is a replenishment use path through which exhaust (air) supplied from the exhaust path 14 to the gas chamber 25 of the low-pressure reservoir 10 flows. .

  A first switching valve 15 is provided at a branch portion of the supply path 31 in the exhaust path 14. The exhaust path 14 and the supply path 31 are connected via the first switching valve 15. The first switching valve 15 is in a state where the exhaust path 14 is in a state where the exhaust path 14 upstream of the first switching valve 15 is connected to the supply path 31 and an exhaust path downstream of the first switching valve 15. 14 is switched to a state in which exhaust gas is circulated. The first switching valve 15 is normally in a state in which exhaust gas is circulated through the exhaust path 14, and is in a state in which the exhaust path 14 upstream of the first switching valve 15 and the supply path 31 are connected at the time of switching. .

  A second switching valve 32 is provided at the branch portion of the air flow passage 28. The supercharging path 30 and the replenishing path 31 are connected via the second switching valve 32. The second switching valve 32 is in a state where the air flow passage 28 is in a state where the gas chamber 25 of the low pressure reservoir 10 is connected to the supercharging path 30 and a state where the gas chamber 25 of the low pressure reservoir 10 is connected to the supply path 31. Switch to. The second switching valve 32 is normally connected to the gas chamber 25 of the low-pressure reservoir 10 and the intake passage 12, and is switched to connect the gas chamber 25 of the low-pressure reservoir 10 and the exhaust passage 14. .

  Further, an adjustment valve 33 is provided upstream of the supercharging path 30. The adjustment valve 33 has a function of adjusting the supply flow rate of air supplied from the gas chamber 25 of the low pressure reservoir 10 to the intake passage 12. Further, a heat exchanger 34 is provided at an intermediate portion of the supply path 31. The heat exchanger 34 has a function of exchanging heat between the exhaust gas flowing through the supply path 31 and the outside air, and plays a role of cooling the exhaust gas supplied to the low-pressure reservoir 10.

  The control device 11 includes hardware such as a CPU (Central Processing Unit) and a memory, and software such as a control program, and has a function of comprehensively controlling deceleration regeneration and power running of the vehicle C. . For example, drive control of the engine 1 and the oil pump motor 8, connection control of the first clutch 2 and the second clutch 7, opening / closing control of the opening / closing valves 26, 27, 29 of the high pressure accumulator 9 and the low pressure reservoir 10, a first switching valve 15 and the switching control of the second switching valve 32, the opening control of the adjustment valve 33, and the like are performed by the control device 11.

  In addition, the vehicle C is provided with various sensors for controlling the regeneration system ERS.

  Specifically, an intake pressure sensor 35 is provided in the intake path 12 upstream of the throttle 13. The intake pressure sensor 35 detects the pressure of intake air flowing through the intake path 12. The high pressure accumulator 9 is provided with a pressure sensor 36. The pressure sensor 36 detects the internal pressure of the gas chamber 21 of the high pressure accumulator 9.

  The low pressure reservoir 10 is provided with a pressure sensor 37 and a position sensor 38. The pressure sensor 37 detects the pressure in the gas chamber 25 of the low pressure reservoir 10. The position sensor 38 detects the position in the sliding direction of the piston 23 inside the reservoir container 22.

  The engine 1 is provided with a crank angle sensor 39. The crank angle sensor 39 detects a rotation angle of a crankshaft (not shown). In addition, the vehicle C is provided with an accelerator sensor 40 and a brake sensor 41. The accelerator sensor 40 detects the accelerator opening according to the amount of operation of the accelerator pedal, that is, the amount of depression. The brake sensor 41 detects the amount of operation of the brake pedal.

  While the automobile C is in operation, the detection values of these sensors 35 to 41 are output to the control device 11. The control device 11 controls the regenerative system ERS based on these detection values.

-Control of regenerative system-
Next, the operation and control of the regenerative system ERS will be described.

<Deceleration regeneration / Power running control>
The regeneration system ERS performs deceleration regeneration and power running as basic operations. These deceleration regeneration and power running will be described with reference to FIGS. FIG. 2 is a conceptual diagram showing a state of the automobile C during deceleration regeneration. FIG. 3 is a conceptual diagram showing a state of the vehicle C during powering.

  For example, when the accelerator pedal is not depressed or the brake pedal is depressed while the vehicle C is traveling, the control device 11 executes the deceleration regeneration control. In the deceleration regeneration control, as shown in FIG. 2, the on-off valves 9a and 10a of the high-pressure accumulator 9 and the low-pressure reservoir 10 are opened, the first clutch 2 is disengaged and the second clutch 7 is engaged, and the drive wheels 5 Is input to the oil pump motor 8. Thereby, the oil pump motor 8 is driven as an oil pump, and the oil in the low pressure reservoir 10 is sent to the high pressure accumulator 9. As a result, the internal pressure of the high pressure accumulator 9 increases, and the oil pressurized to a high pressure is accumulated in the high pressure accumulator 9 (deceleration regeneration).

  In addition, the control device 11 executes power running control when the vehicle C starts, accelerates from a decelerating run or a constant speed run, and further runs at a constant speed on an uphill. In the power running control, as shown in FIG. 3, the on / off valves 9a and 10a of the high pressure accumulator 9 and the low pressure reservoir 10 are opened, the first clutch 2 is disengaged and the second clutch 7 is connected, and the high pressure accumulator 9 is connected. Oil flows out toward the low pressure reservoir 10. The oil pump motor 8 is driven as a hydraulic motor by the discharge pressure of oil from the high pressure accumulator 9, and the power is output to the drive wheels 5 (power running). As a result, the automobile C is hydraulically driven. Then, the oil flowing out from the high pressure accumulator 9 is collected in the low pressure reservoir 10.

<Supercharging control>
In FIG. 4, the conceptual diagram which shows the operation | movement of the main structure of the regeneration system ERS at the time of execution of supercharging control is shown. The control apparatus 11 of this embodiment performs supercharging control at the time of the power running mentioned above. In this supercharging control, as shown in FIG. 4, the control device 11 opens the opening / closing valve 29 of the gas inlet / outlet port 10b of the low-pressure reservoir 10 while keeping the first switching valve 15 and the second switching valve 32 in the normal state. As a result, the air in the gas chamber 25 of the low-pressure reservoir 10 is circulated through the supercharging path 30, and the air in the gas chamber 25 is supplied to the intake path 12 via the supercharging path 30. Thereby, the pressure of the intake passage 12 is increased, and the efficiency of filling the air into the cylinder of the engine 1 is improved.

  At this time, the control device 11 adjusts the air supply flow rate from the gas chamber 25 of the low-pressure reservoir 10 to the intake passage 12 by adjusting the opening of the adjustment valve 33.

  Specifically, first, a supercharging pressure (hereinafter referred to as “target supercharging pressure”) necessary to realize acceleration according to the accelerator opening is acquired. The target boost pressure is acquired based on the accelerator opening and the engine speed. Here, the engine speed is obtained from the detection value of the crank angle sensor 39. The control device 11 stores in advance a boost pressure map in which a boost pressure corresponding to the accelerator opening and the engine speed is defined.

  FIG. 5 shows an image diagram of the supercharging pressure map. In the supercharging pressure map shown in FIG. 5, the engine speed is divided into, for example, three stages of a high engine speed range, a medium engine speed range, and a low engine speed range, and the accelerator opening and the target boost pressure are determined for each engine speed range. The relationship is defined, and the target supercharging pressure increases as the accelerator opening increases and the engine speed increases. The control device 11 acquires the target boost pressure by comparing the accelerator opening and the engine speed with such a boost pressure map.

  Based on the acquired target supercharging pressure, the pressure of the gas chamber 25 of the low-pressure reservoir 10 detected by the pressure sensor 37, and the intake air pressure detected by the intake pressure sensor 35, the control device 11 The opening degree of the adjustment valve 33 is adjusted so that air flows through the supercharging path 30 at a flow rate necessary to realize the supercharging pressure.

  According to such adjustment of the opening degree of the regulating valve 33, the supply flow rate of the air supplied from the low pressure reservoir 10 to the intake passage 12 when the supercharging control is executed increases as the required torque increases, and conversely decreases as it decreases. Become. Thereby, regeneration system ERS can perform supercharging according to a run demand.

  The supercharging pressure map is unique to each engine 1 and is obtained in advance by actual measurement or the like. Therefore, the supercharging pressure map shown in FIG. 5 is merely an example, and may have different characteristics depending on the engine 1.

  The scene where this supercharging control is executed will be described below by taking the time when the automobile C starts as an example. FIG. 6 shows a flowchart of supercharging control when the vehicle C starts.

  When the vehicle C starts, that is, when the accelerator pedal is depressed from the stop state, first, detection values of various sensors 35 to 41 are input to the control device 11 as shown in FIG. 6 (step ST001). The detected values of these various sensors 35 to 41 include the accelerator opening Acc and the pressure Ph of the gas chamber 21 of the high pressure accumulator 9.

  The control device 11 determines whether or not the input detection value of the pressure sensor 36 of the high pressure accumulator 9, that is, the pressure Ph of the gas chamber 21 of the high pressure accumulator 9 is smaller than a predetermined pressure Pr1 (step ST002). . The predetermined pressure Pr1 here is a reference pressure for determining whether or not the hydraulic energy accumulated in the high pressure accumulator 9 is a sufficient amount for execution of power running, that is, whether or not the vehicle C can be used as starting power. It is.

  At this time, when the pressure Ph of the gas chamber 21 of the high pressure accumulator 9 is smaller than the predetermined pressure Pr1, the second clutch 7 is disengaged and the first clutch 2 is engaged, the engine 1 is started, The power is output to the drive wheel 5. As a result, the automobile C starts using the engine 1 as a power source (step ST003).

  When the pressure Ph of the gas chamber 21 of the high pressure accumulator 9 is equal to or higher than the predetermined pressure Pr1, it is subsequently determined whether or not the accelerator opening Acc is smaller than the predetermined first opening A1 ( Step ST004). Here, the first opening A1 is a small range and a medium range in which the accelerator opening Acc is divided into three stages of a relatively small range, a medium range, and a relatively large range between fully closed and fully open. It is a reference opening for determining which one of the ranges belongs to.

  At this time, if the accelerator opening Acc is smaller than the first opening A1, the second clutch 7 is engaged, the oil pump motor 8 is driven as a hydraulic motor, and the power is output to the drive wheels 5 ( Step ST005). As a result, the automobile C starts using the oil pump motor 8 (functioning as a hydraulic motor) as a power source. In this case, after the start of the automobile C, the engine 1 is started, the second clutch 7 is disengaged, and the first clutch 2 is connected, whereby the hydraulic travel is switched to the engine travel.

  Further, when the accelerator opening Acc is equal to or greater than the first opening A1, it is subsequently determined whether or not the accelerator opening Acc is smaller than a predetermined second opening A2 (step ST006). The second opening A2 here is a reference opening for determining whether the accelerator opening Acc belongs to a medium range or a large range among the three stages as described above.

  At this time, when the accelerator opening degree Acc is smaller than the second opening degree A2, both the first clutch 2 and the second clutch 7 are connected to drive the oil pump motor 8 as a hydraulic motor and the engine 1. They are started and their power is output to the drive wheels 5. As a result, the automobile C starts using both the oil pump motor 8 (functioning as a hydraulic motor) and the engine 1 as power sources. In this case, the control device 11 does not execute the supercharging control.

  Even when the accelerator opening Acc is equal to or greater than the second opening A2, both the first clutch 2 and the second clutch 7 are connected to drive the oil pump motor 8 as a hydraulic motor and start the engine 1. These powers are output to the drive wheels 5. As a result, the automobile C starts using both the oil pump motor 8 (functioning as a hydraulic motor) and the engine 1 as power sources. In this case, the control device 11 performs supercharging control.

<Supply control>
FIG. 7 is a conceptual diagram showing the operation of the main configuration of the regenerative system ERS when the supply control is executed. The control device 11 according to the present embodiment performs replenishment control if the piston 23 of the low-pressure reservoir 10 is at the limit position on the oil inlet / outlet port 10a side as shown in FIG. 7 at the time of deceleration fuel cut for stopping the fuel supply to the engine 1. Run. The deceleration fuel cut is performed when a predetermined fuel cut condition is satisfied when the engine 1 is in a deceleration operation state. At the time of this deceleration fuel cut, the combustion stroke is not performed in the engine 1, and the air sucked into the engine 1 circulates in the exhaust passage 14 in a relatively low temperature state as exhaust without being burned.

  In this replenishment control, as shown in FIG. 7, the control device 11 puts the first clutch 2 into a connected state, puts the first switching valve 15 and the second switching valve 32 into a switching state, and sets the gas in the low-pressure reservoir 10. The engine 1 is driven by the rotation of the driving wheel 5 by opening the on-off valve 29 of the inlet / outlet 10b, and the exhaust (air) compressed in the exhaust stroke from the exhaust path 14 to the gas chamber 25 of the low-pressure reservoir 10 by driving the engine. Supply. As a result, the gas chamber 25 is replenished with air that has decreased due to the execution of the supercharging control described above. At this time, the engine 1 functions as a compression pump that sends compressed air into the gas chamber 25 of the low-pressure reservoir 10.

  This replenishment control will be described below with an example. FIG. 8 shows a flowchart of supply control.

  Also in the replenishment control, as shown in FIG. 8, the detection values of the various sensors 35 to 41 are input to the control device 11 (step ST101). The detection values of these various sensors 35 to 41 include the pressure Pl of the gas chamber 25 of the low pressure reservoir 10 and the piston position Po of the low pressure reservoir 10. When the detection values of various sensors 35 to 41 are input, control device 11 determines whether deceleration fuel cut is being executed (step ST102).

  At this time, if the deceleration fuel cut is not being executed, the process returns without supplying air to the gas chamber 25 of the low-pressure reservoir 10. If the deceleration fuel cut is being executed, it is subsequently determined whether or not the piston position Po of the low-pressure reservoir 10 is at the limit position on the oil inlet / outlet side 10a as shown in FIG. 7 (step ST103). . At this time, if the piston position Po is not at the limit position on the oil inlet / outlet port 10a side, the process returns without supplying air to the gas chamber 25 of the low pressure reservoir 10.

  When the piston position Po of the low pressure reservoir 10 is at the limit position on the oil inlet / outlet port 10a side, subsequently, it is determined whether or not the pressure Pl of the gas chamber 25 of the low pressure reservoir 10 is smaller than a predetermined pressure Pr2. (Step ST104). The predetermined pressure Pr2 here is reduced to such a degree that the air in the gas chamber 25 of the low-pressure reservoir 10 may impair the pressure buffering function of the gas chamber 25 or fail to perform sufficient supercharging to the intake passage 12. It is a reference pressure for determining whether or not there is.

  At this time, when the pressure Ph of the gas chamber 25 of the low pressure reservoir 10 is equal to or higher than the predetermined pressure Pr2, the first switching valve 15 and the second switching valve 32 are maintained in the normal state, and the gas in the low pressure reservoir 10 is maintained. The supply of exhaust gas to the chamber 25 is prohibited (step ST105). Further, when the pressure Pl of the gas chamber 25 of the low pressure reservoir 10 is lower than the predetermined pressure Pr2, the first switching valve 15 and the second switching valve 32 are switched to be in a switching state and are distributed to the exhaust path 14. Exhaust gas is supplied to the gas chamber 25 of the low-pressure reservoir 10 by driving the engine 1 (functioning as a compression pump) (step ST106). Then return.

-Effect of the embodiment-
According to the regenerative system ERS according to this embodiment, the air stored in the low-pressure reservoir 10 is supplied to the intake passage 12 while the air in the gas chamber 25 of the low-pressure reservoir 10 is supplied to the intake passage 12 when the vehicle C is powered, for example, when acceleration is performed. Is used for supercharging the engine 1, so that the engine speed can be smoothly increased by the supercharging effect even after the oil in the high pressure accumulator 9 has completely flowed out and switched from hydraulic traveling to engine traveling. As a result, it is possible to improve the acceleration performance by suppressing the occurrence of rattling in acceleration, and to improve driving performance by reducing the uncomfortable feeling given to the driver.

  Further, according to the start control of the vehicle C in this embodiment, the power source is limited to the oil pump motor 8 and the oil pump motor 8 and the engine 1 according to the accelerator opening Acc, and further the oil In the case where both the pump motor 8 and the engine 1 are used as power sources, it is divided into a case where the supercharging control is executed and a case where the supercharging control is not executed, and furthermore, air used for supercharging based on the accelerator opening and the engine speed. Since the supply flow rate is adjusted, acceleration performance (acceleration response) commensurate with the travel request can be obtained.

  Further, according to the regenerative system ERS according to this embodiment, the uncombusted exhaust gas at the time of deceleration fuel cut, that is, the relatively low temperature air sucked into the engine 1 is supplied to the gas chamber 25 of the low pressure reservoir 10. Therefore, the adverse effect on the low pressure reservoir 10 due to the exhaust heat can be suppressed, and a desired supercharging effect can be obtained when the supercharging control is executed by maintaining the oxygen concentration of the air in the gas chamber 25 of the low pressure reservoir 10. it can.

  As described above, a preferred embodiment has been described as an example of the technique disclosed herein. However, the technology disclosed herein is not limited to this, and can also be applied to embodiments in which changes, replacements, additions, omissions, etc. have been made as appropriate. Moreover, it is also possible to combine each component demonstrated by the said embodiment into a new embodiment. In addition, the constituent elements described in the accompanying drawings and the detailed description may include constituent elements that are not essential for solving the problem. For this reason, it should not be immediately recognized that these non-essential components are essential because they are described in the accompanying drawings and detailed description.

  For example, the following embodiment may be configured as follows.

  In the said embodiment, although air was stored in the gas chamber 21 of the high pressure accumulator 9, it is not restricted to this. The gas chamber 21 may store other gas such as nitrogen gas instead of air.

  In the above embodiment, the regenerative system ERS including the oil pump motor 8 having both functions of the oil pump and the hydraulic motor has been described as an example. However, the present invention is not limited to this, and the regenerative system ERS includes the oil pump motor 8. Instead of this, an oil pump and a hydraulic motor may be provided separately. In this case, for example, the high pressure accumulator 9 and the low pressure reservoir 10 are connected via an oil pump and also connected via a hydraulic motor, and are connected to the oil pump using a switching valve or the like. It suffices if the oil path is connected so that it can be switched to the state connected to the hydraulic motor.

  In the above embodiment, the air in the gas chamber 25 of the low-pressure reservoir 10 that has decreased with the execution of the supercharging control is supplied with the exhaust gas (air) that flows through the exhaust path 14 when the engine 1 is decelerated. The gas chamber 25 of the low-pressure reservoir 10 may be replenished at other timings, such as when the fuel supply to the engine 1 is stopped except when the deceleration fuel is cut. Further, in order to supply air to the gas chamber 25 of the low pressure reservoir 10, the exhaust of the engine 1 may not be used, and a dedicated device or mechanism for that purpose may be provided separately.

  In the above embodiment, the exhaust gas is supplied to the gas chamber 25 of the low-pressure reservoir 10 when the piston position of the low-pressure reservoir 10 is at the limit position on the oil inlet / outlet port 10a side. The exhaust gas is supplied to the chamber 25 when the piston position is positioned closer to the oil inlet / outlet port 10a than a predetermined position (for example, a position when the stored oil is about half the capacity of the oil chamber 24). Alternatively, it may be performed in consideration of the execution time or number of times of supercharging control.

  As described above, the technology disclosed herein is useful for a vehicle regeneration system including a high pressure accumulator that stores oil under pressure and a low pressure reservoir.

C ... Automobile (vehicle), ERS ... Regenerative system, 1 ... Engine,
2 ... 1st clutch, 3 ... Transmission, 4 ... Differential gear,
5 ... drive wheels, 6 ... coupling mechanism, 7 ... second clutch, 8 ... oil pump motor,
9 ... High pressure accumulator, 9a ... Oil inlet / outlet, 10 ... Low pressure reservoir,
10a ... Oil inlet / outlet, 10b ... Gas inlet / outlet, 11 ... Control device, 12 ... Intake path,
13 ... Throttle, 14 ... Exhaust path, 15 ... First switching valve, 16 ... Catalyst device,
17 ... Muffler, 18 ... Accumulator, 19 ... Piston, 20 ... Oil chamber,
21 ... Gas chamber, 22 ... Reservoir container, 23 ... Piston, 24 ... Oil chamber,
25 ... Gas chamber, 26, 27 ... Open / close valve, 28 ... Air flow passage, 29 ... Open / close valve,
30 ... Supercharging path, 31 ... Supply path, 32 ... Second switching valve, 33 ... Adjusting valve,
34 ... heat exchanger, 35 ... intake pressure sensor, 36, 37 ... pressure sensor,
38 ... Position sensor, 39 ... Crank angle sensor, 40 ... Accelerator sensor,
41 ... Brake sensor

Claims (5)

A regenerative system for a vehicle comprising a high pressure accumulator for storing oil under pressure and a low pressure reservoir,
The low-pressure reservoir has a container and a piston slidably disposed inside the container,
The piston divides the inside of the container in a sliding direction into an oil chamber in which oil is stored and a gas chamber in which air is stored,
The gas chamber of the low pressure reservoir is connected to the intake path of the engine,
A regenerative system for a vehicle, further comprising a control device that performs supercharging control for increasing pressure in the intake passage by supplying air in the gas chamber of the low-pressure reservoir to the intake passage during powering. The vehicle regeneration system according to claim 1,
The supercharging path connecting the gas chamber of the low-pressure reservoir and the intake path is provided with an adjustment valve that adjusts the supply flow rate of air supplied from the gas chamber of the low-pressure reservoir to the intake path,
In the supercharging control, the supply flow rate is adjusted by adjusting the opening degree of the adjusting valve based on the accelerator opening degree and the engine speed, and the regenerative system for a vehicle is characterized in that the supply flow rate is adjusted. In the vehicle regeneration system according to claim 1 or 2,
The gas chamber of the low pressure reservoir is also connected to the exhaust path of the engine,
The control device is configured to drive the engine by rotation of a driving wheel during deceleration regeneration and to perform supply control for supplying exhaust gas from the exhaust path to the gas chamber of the low-pressure reservoir by driving the engine. Vehicle regeneration system. In the vehicle regeneration system according to claim 3,
The regenerative system for a vehicle, wherein the control device executes the replenishment control when a deceleration fuel cut of the engine is cut. In the vehicle regeneration system according to claim 4,
A catalyst device is provided in the exhaust path,
A regenerative system for a vehicle, wherein the gas chamber of the low-pressure reservoir is connected to the exhaust path upstream of the catalyst device.

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