JP2015086811A - Gas pressure accumulation system of vehicle and gas pressure accumulation method of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas pressure accumulation system and a gas pressure accumulation method of a vehicle capable of minimizing degradation of fuel consumption by reducing drive work by accumulating a pressure while spending a comparatively long time in a normal running state, in particular, in a running state almost at a constant speed of the vehicle, and achieving maximum braking energy recoverable by a compressor by accumulating a pressure with the maximum drive work when the braking energy of the vehicle can be utilized, in the gas pressure accumulation system and the gas pressure accumulation method in which air, an exhaust gas or their mixture is accumulated in a pressure accumulation container.SOLUTION: A filling device for filling a pressure accumulation container with a gas, is constituted to be connectable with an axle for running a vehicle or a rotary drive shaft for transmitting torque for running to the axle. The filling device is driven by rotary torque of the axle or the rotary drive shaft in a vehicle running state, and the filling device is driven by braking torque of the axle or the rotary drive shaft in a vehicle braking state.

Description

  The present invention relates to a vehicle gas pressure accumulation system and a vehicle gas pressure accumulation method for accumulating air, exhaust gas, or a gas mixture thereof in a pressure accumulation container.

  A turbocharger mounted on an internal combustion engine operates the turbine using the energy of the exhaust gas from the engine, and drives the compressor blades directly connected to the shaft of the turbine to take in the intake air. The compressed air is supplied to the cylinder according to the engine load.

  However, in this turbocharger, in a transient operation state in which the load of the internal combustion engine suddenly increases, a turbo lag is generated that delays the increase of the boost pressure to the required pressure. Run short. As a countermeasure, the EGR amount is decreased to increase the ratio of the air amount in the cylinder. Therefore, the target EGR amount cannot be ensured, and NOx increases due to the limitation of the EGR amount. In addition, there is a smoke limit problem that fuel injection amount per cycle can be suppressed because soot is generated due to deterioration of combustion due to insufficient air amount, and acceleration performance required at start and overtaking by suppressing the fuel injection amount supplied Cannot be obtained.

  In order to avoid these turbo lag problems, a mechanical supercharger that drives the compressor with the power of the crankshaft of the internal combustion engine may be used, but when the engine speed is determined, the required fuel injection per cycle Regardless of the amount, a certain amount of air is supercharged, so that when the fuel injection amount is small, the compressor performs useless driving work. Moreover, since a positive displacement supercharger is used for a mechanical supercharger, the driving work is large. Therefore, in general, the fuel efficiency is deteriorated in this mechanical supercharging system.

  Therefore, as a countermeasure against NOx increase and acceleration performance decrease due to shortage of air amount and EGR gas amount due to turbo lag in turbo type turbocharger and fuel consumption deterioration due to mechanical supercharger, internal combustion at the time of start or acceleration of vehicle etc. An accumulator-type supercharging assist system that releases a mixture of air and exhaust gas pressurized in an accumulator vessel into an intake passage of an internal combustion engine may be employed in a transient operation state of the engine. In this system, the boost pressure can be raised and both the intake air amount and the EGR amount can be secured, so that the fuel injection amount can be increased by increasing the air amount, and the acceleration performance can be improved. , NOx and soot emissions can be reduced.

  As this accumulator-type supercharging assist system, for example, in an internal combustion engine using gas stored in a gas accumulator for supercharging assist, the pressure in the intake manifold, the pressure at the compressor outlet, etc. are detected, A supercharging assistance method for an internal combustion engine that reduces the consumption of gas in a storage gas container used for supercharging assistance by starting control of supercharging assistance using superposed gas for supercharging immediately before the smoke limit is applied, and An internal combustion engine has been proposed (see, for example, Patent Document 1).

  In this pressure accumulating supercharging assist system, a large amount of driving work is required to accumulate a high-pressure air-fuel mixture in the pressure accumulating vessel, but the driving work increases as the pressure is accumulated at a higher speed, which causes a deterioration in fuel consumption.

  On the other hand, in recent years, even in the world, internal combustion engines tend to be down-sized with small displacement and high output, but there is a problem that the braking force of the vehicle is insufficient due to the small displacement. For this reason, an auxiliary brake system is often installed.

  In addition, research on recovery of braking energy is also underway to improve fuel economy. For example, although it is an EGR substitute device, it is a braking energy recovery method in which driving work for pressure accumulation is obtained by braking energy that is discarded as heat in the atmosphere. As a means for recovering braking energy, a continuously variable transmission such as a CVT (continuous variable transmission) is used in accordance with the vehicle speed in a braking state by setting the transmission gear ratio to be transmitted to the exhaust compressor. There has been proposed a braking energy recovery device for a vehicle that obtains pressure-accumulation work in a pressure-accumulation supercharging assist system (for example, see Patent Document 2).

  In this vehicle braking energy recovery device, when the vehicle speed decreases during deceleration and the rotation speed of the propulsion shaft that rotates the wheels of the vehicle decreases, the speed ratio of the continuously variable transmission is controlled, and the rotation speed of the compressor for pressure accumulation Even if the vehicle speed drops, a large amount of braking energy is generated, and this energy is used to drive the compressor. As a result, large braking energy is recovered by controlling the rotational speed of the compressor according to the vehicle speed during deceleration. In addition, by controlling the rotation speed of the compressor so that the minimum required driving work is achieved during normal operation, the braking force is insufficient and the fuel consumption is improved.

  However, in order to obtain a larger braking force, there is a problem that there is no method other than overrunning the compressor. On the other hand, the present inventor has obtained knowledge that a larger braking energy can be recovered by adding a new mechanism and a control method to the method of recovering the braking energy only by controlling the rotation speed of the compressor.

JP 2012-251489 A JP 2012-20711 A

  The present invention has been made in view of the above, and an object of the present invention is to provide a vehicle gas pressure accumulation system and a vehicle gas pressure accumulation method for accumulating air, exhaust gas, or a gas mixture thereof in a pressure accumulation container. In normal driving conditions of the vehicle, especially when driving at a constant speed, accumulating pressure over a relatively short period of time reduces the driving work of the gas filling device, minimizes fuel consumption deterioration, and reduces vehicle braking energy. When it can be used, the object is to provide a vehicle gas pressure accumulation system and a vehicle gas pressure accumulation method capable of obtaining the maximum braking energy that can be recovered by the gas filling device by accumulating pressure with the maximum driving work.

  In order to achieve the above object, a vehicle gas pressure accumulation system according to the present invention is a vehicle gas pressure accumulation system for accumulating air, exhaust gas, or a gas mixture thereof in a pressure accumulation vessel mounted on a vehicle. A gas filling device for filling the gas, and a control device for controlling the gas filling device and having a vehicle state determining means for judging whether the vehicle is in a running state or a vehicle braking state. The filling device can be connected to an axle for running the vehicle or a rotary drive shaft that transmits a running torque to the axle, and in the vehicle running state, the gas filling device rotates the axle or the rotary drive shaft. Driven by torque, the gas filling device is configured to be driven by braking torque of the axle or the rotary drive shaft in a vehicle braking state.

  In the gas accumulation system for a vehicle described above, the gas filling device may be a positive displacement compressor, and the control device may be dead from the top dead center of the piston of the positive displacement compressor when the vehicle is running. The suction valve is opened during the movement to the point and the discharge valve is closed to suck the gas into the cylinder, and the suction valve is closed during the movement from the bottom dead center to the top dead center of the piston. At the same time, the exhaust valve is opened to control the exhaust of the gas. In the vehicle braking state, the exhaust valve is opened from a time earlier than the top dead center to a time earlier than the bottom dead center. Control is performed until the time before the backflow, and the opening timing of the suction valve is from the time after the exhaust valve is closed to the time later than the bottom dead center.

  The vehicle gas pressure accumulation method of the present invention for achieving the above object is the vehicle gas pressure accumulation method for accumulating air, exhaust gas, or a gas mixture thereof in a pressure accumulation container mounted on the vehicle. The gas filling device for filling the container with gas is configured to be connectable to an axle for running the vehicle or a rotary drive shaft for transmitting running torque to the axle, and is in a vehicle running state or a vehicle braking state. In the vehicle running state, the gas filling device is driven by the rotational torque of the axle or the rotational drive shaft. In the vehicle braking state, the gas filling is performed by the braking torque of the axle or the rotational drive shaft. A method characterized by driving the apparatus.

  According to the vehicle gas pressure accumulation system and the vehicle gas pressure accumulation method of the present invention, in a vehicle gas pressure accumulation system and a vehicle gas pressure accumulation method for accumulating air, exhaust gas, or a gas mixture thereof in a pressure accumulation container, In normal driving conditions, especially when driving at a constant speed, accumulating pressure over a relatively long time can reduce the driving work of the gas filling device, minimize fuel consumption deterioration, and use vehicle braking energy. Sometimes, the maximum braking energy that can be recovered by the gas filling device can be obtained by accumulating pressure with the maximum driving work.

It is a figure showing typically composition of a gas accumulation system of vehicles of an embodiment concerning the present invention. It is a figure which shows an example of the control flow of the gas pressure accumulation method of the vehicle of embodiment which concerns on this invention. It is a figure which shows typically the valve opening timing of the suction valve and discharge valve of the vehicle running state of the 1st control method in a positive displacement compressor. It is a figure which shows typically the valve opening timing of the suction valve and discharge valve of the vehicle braking state of the 2nd control method in a positive displacement compressor.

  DESCRIPTION OF EMBODIMENTS Hereinafter, a vehicle gas pressure accumulation system and a vehicle gas pressure accumulation method according to embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, a vehicle gas pressure accumulation system 20 according to an embodiment of the present invention is provided in a vehicle 1 equipped with an engine (internal combustion engine) 10. Here, a description will be given mainly of a configuration in which supercharging assistance is performed using a gas M that is a mixture of air A and exhaust gas G for supercharging assistance. However, the present invention is not limited to this. Further, when supercharging assistance is performed only with air A, the present invention can also be applied to the case where EGR gas is supplied only with exhaust gas G.

  Further, in the configuration of FIG. 1, the turbo-type supercharger is not particularly shown, but the application target of the present invention is a pressure-accumulation type even if the vehicle is equipped with an engine equipped only with a pressure-accumulation type supercharge assist system. It may be a vehicle equipped with an engine equipped with both a supercharging assist system and a turbo-type supercharging system. Furthermore, the vehicle which mounts the hybrid system provided with an internal combustion engine and a motor generator may be sufficient.

  In this vehicle 1, a part of the exhaust gas G passing through the exhaust passage 11 of the engine 10 is led to an exhaust branch passage (for example, EGR pipe) 12 and cooled by a gas cooler (for example, EGR cooler) 13, and a three-way valve 14. Leading to. An air intake passage 15 for taking in air A and a gas introduction passage 21 are connected to the three-way valve 14. By switching the three-way valve 14, either the air A or the exhaust gas G can be selected and sent to the gas introduction passage 21.

  The gas A or G introduced into the gas introduction passage 21 is compressed and pressurized by a positive displacement compressor (positive displacement compressor) 24 which is a gas filling device, and is pumped to the pressure accumulating vessel 27 through the pressurized gas passage 25. Is done. The drive shaft of the positive displacement compressor 24 is connected to the axle 2 that drives the wheels 3 of the vehicle 1 via a continuously variable transmission 22 formed of CVT or the like and an electromagnetic clutch (clutch) 23. The pressurized gas passage 25 is provided with a check valve 26 so that the gas M from the pressure accumulating container 27 does not flow backward to the positive displacement compressor 24 side.

  At the time of this pressure accumulation, the oxygen concentration of the gas M is grasped by using the detection value of the oxygen concentration sensor 31 provided in the pressure accumulation container 27 so that EGR can be performed at an appropriate EGR rate at the time of EGR, The pressure is accumulated so that the amount of the exhaust gas G and the amount of the air A in the gas M in the pressure accumulating container 27 are set to an appropriate ratio so that the oxygen concentration of M becomes a concentration suitable for EGR control. Further, according to the container internal pressure Pim detected by the container internal pressure sensor 32, the gas M is appropriately stored so as not to become equal to or lower than the pressure accumulation lower limit pressure Pic that allows supercharging assistance. Moreover, the temperature sensor 33 for detecting the temperature of the gas M in the accumulator 27 is provided as needed.

  The gas M accumulated in the pressure accumulator 27 is transferred from the pressure accumulator 27 to the intake passage 16 of the engine 10 via the gas supply passage 28 when the engine 10 is in a transient operation state such as when the vehicle is started or accelerated. Used to assist with supercharging by discharging. When the gas M is composed only of air A, only supercharging assistance is provided. When the gas M is composed only of exhaust gas G, only EGR gas is supplied, and the gas M is a mixed gas of air A and exhaust gas G. In the case of comprising, supercharging assistance and EGR assistance are performed.

  In addition, in order to adjust the discharge pressure Po of the gas M discharged from the pressure accumulator 27 to the intake passage 16, the outlet side pressure, which is the secondary side set pressure, can be changed in the gas supply passage 28. A pressure regulating valve (regulator) 29 that can control whether M is released or not is provided. The pressure adjusting valve 29 may be constituted by a passage area changing device (gas passage area variable valve) capable of changing the passage area of the air-fuel mixture. In this case, the pressure can be adjusted with a simple device. . In addition, the function of adjusting the pressure and the function of controlling whether or not the gas M is released may be separately provided, and a device having each function may be provided in the gas supply passage 28.

  At the same time, the gas accumulation system 20 of the vehicle performs control for adjusting the discharge pressure Po of the gas M according to the operating state of the engine 10 and control of the discharge of the gas M at the time of supercharging assistance or EGR gas supply. A control device 41 is provided. The control device 41 is usually configured to be incorporated in an overall system control device 40 that performs overall control of the engine 10 and overall control of a vehicle on which the engine 10 is mounted. Of the overall system control device, the control device 40 that mainly controls the engine 10 in general is generally called an ECU (engine control unit).

  In the present invention, the control device 41 is further configured to control the continuously variable transmission 22, the electromagnetic clutch 23, and the positive displacement compressor 24, and is in a vehicle running state or a vehicle braking state. The vehicle state determination means for determining whether or not there is provided.

  When accumulating the gas M, the control device 41, in the vehicle running state, is an axle 2 that travels the vehicle 1 (or a rotary drive shaft (not shown) that transmits running torque to the axle 2). With the electromagnetic clutch 23 in the connected state, the positive displacement compressor 24 is driven by the rotational torque of the axle 2 to compress and pressurize the air A or the exhaust gas G, and pump it to the pressure accumulating container 27. In the vehicle braking state, the electromagnetic clutch 23 is connected to the axle 2 on which the vehicle 1 travels, and the positive displacement compressor 24 is driven so as to generate the braking torque by the braking torque of the axle 2, in other words, the braking torque. Then, the air A or the exhaust gas G is compressed and pressurized, and is pumped to the pressure accumulating container 27. When the air A or the exhaust gas G is not accumulated in the pressure accumulating container 27, the electromagnetic clutch 23 is disengaged and the positive displacement compressor 24 is separated from the axle 2.

  More specifically, in the control of the positive displacement compressor 24 which is a gas filling device, in the vehicle running state, as shown in FIG. 3, the suction valve is moved between the top dead center and the bottom dead center in the piston stroke. While opening the valve, the exhaust valve is closed, and the air A or the exhaust gas G is sucked into the cylinder of the positive displacement compressor 24 from the gas introduction passage 21 side and moved from the bottom dead center to the top dead center in the piston stroke. In the meantime, the suction valve is closed and the discharge valve is opened, and the control by the first control method for discharging the air A or the exhaust gas G to the pressurized gas passage 25 side is performed.

  In this case, when the top dead center is set at a rotation angle of 0 deg, the bottom dead center is set at a rotation angle of 180 deg, and the top dead center is set at a rotation angle of 360 deg, the suction valve is opened and discharged at a rotation angle of 0 deg to 180 deg. The valve is closed, and the suction valve is closed and the discharge valve is opened between the rotation angles of 180 deg to 360 deg.

  Further, in the vehicle braking state, as shown in FIG. 4, the air A or exhaust gas discharged from the pressurized gas passage 25 from the time earlier than the top dead center to the bottom dead center as the opening period of the discharge valve is reached. Until the time point before G flows backward, the air A or the exhaust gas G is discharged to the pressurized gas passage 25 side, and the opening timing of the suction valve is later than the bottom dead center from the time point after closing the discharge valve. Until now, the control is performed by the second control method in which the air A or the exhaust gas G is sucked into the cylinder of the positive displacement compressor 24 from the gas introduction passage 21 side.

  In this case, when the top dead center is set at the rotation angle 0 deg, the bottom dead center is set at the rotation angle 180 deg, and the top dead center is set at the rotation angle 360 deg, the discharge valve is opened and the suction valve is set between the rotation angles β1 deg to β2 deg. Is closed, the air A or the exhaust gas G in the cylinder is discharged, the exhaust valve is closed and the suction valve is opened between the rotation angles β2deg to β3deg, and the volume of the air A or the exhaust gas G is increased. Suction into the cylinder of the mold compressor 24. Further, between the rotation angles β2deg to (360 + β1) deg, both the suction valve and the exhaust valve are closed to prevent the exhausted air A or exhaust gas G from flowing backward.

  In this vehicle braking state, the electromagnetic clutch 23 is connected, the positive displacement compressor 24 is connected to the axle 2 via the continuously variable transmission 22, and the speed ratio Rg of the continuously variable transmission 22 is set. Is preferably switched to a gear ratio Rgm that maximizes the rotational speed Nb of the positive displacement compressor 24 with respect to the rotational speed Na of the axle 2.

  An example of supercharging assistance of the control device 41 will be briefly described. When the operating state of the engine 10 is in the low rotation speed region R1 during supercharging assistance, the gas M is The maximum combustion pressure Pmax in the cylinder (cylinder) of the engine 10 does not exceed the allowable maximum combustion pressure Pmc, and is released to a set pressure Po1 set in advance according to the minimum boost pressure Pmin commensurate with the fuel injection amount q. A pressure Po is set, and supercharging assistance is performed at the discharge pressure Po. This set pressure Po1 is set in advance by experiments or the like, but is set to a constant value in the low rotation speed region R1, a value that changes according to the operating state of the engine 10, or the minimum boost pressure Pmin. Set the value by adding it to the added value. As a result, supercharging assistance is performed at a discharge pressure Po commensurate with the operating state of the engine 10. The discharge pressure Po at this time is, for example, about 80 kPa to 120 kPa although it depends on the capacity of the pressure accumulating container 27 and the like.

  In addition, when the operation state of the engine 10 is in the middle / high rotational speed region R2 at the time of supercharging assistance, control is performed to assist supercharging by setting the discharge pressure Po to the residual pressure Pr of the accumulator 27. . The discharge pressure Po at this time changes from moment to moment depending on the remaining amount of the gas M from the pressure accumulating vessel 27. The discharge pressure Po at this time is, for example, in the range of about 120 kPa to 250 kPa, depending on the capacity of the pressure accumulating container 27 and the like. As a result, the amount of gas M released is adjusted and released in accordance with the operating state of the engine 10 in the transient operation state, and the necessary and sufficient gas M is released.

  Next, a vehicle gas pressure accumulation method using the vehicle gas pressure accumulation system 20 will be described with reference to the control flow of FIG.

  The control flow of FIG. 2 is that in the vehicle equipped with the gas pressure accumulation system 20 of this vehicle, the pressure Pim in the pressure accumulation container 27 decreases, and the pressure of the gas M needs to be accumulated below the pressure accumulation lower limit pressure Pic. In this case, it is called from the advanced control flow, and after executing the contents of the control flow in FIG. 2, it returns to the advanced control flow, and when pressure accumulation is required, it is called from the advanced control flow. During operation of the engine 10, it is shown that it is repeatedly called and implemented every time pressure accumulation is required, and is shown as a control flow that ends with the end of this advanced control flow.

  When the control flow of FIG. 2 is called from an advanced control flow and starts, it is determined in step S11 whether or not pressure accumulation in the pressure accumulation container 27 is necessary. This determination is made based on whether or not the in-container pressure Pim of the accumulator 27 is equal to or lower than the accumulator lower limit pressure Pic. If it is determined in step S11 that pressure accumulation is not necessary (NO), the process returns to the advanced control flow and waits for the next pressure accumulation necessary state.

  If it is determined in step S11 that pressure accumulation is required (YES), the process proceeds to step S12, the electromagnetic clutch 23 is set in the connected state, and the process proceeds to the next step S13. In step S13, it is determined whether the driving state of the vehicle 1 is a vehicle running state or a vehicle braking state. This determination is made by vehicle state determination means for determining whether the vehicle is in a running state or a vehicle braking state.

  If it is determined in step S13 that the vehicle is in a running state (YES), the process goes to step S14, where the speed ratio Rg of the continuously variable transmission 22 is determined by the engine speed Nem and the accelerator opening α. Corresponding to the injection amount qm, it is calculated and set or changed using the gear ratio setting map Mg or the like, and the rotational torque of the axle 2 is transmitted to the rotational drive shaft of the positive displacement compressor 24 to drive the positive displacement compressor 24. To do. The positive displacement compressor 24 is driven by performing on-off valve control of the suction valve and the discharge valve at the timing of the first control method as shown in FIG. Thereby, the air A or the exhaust gas G is accumulated in the pressure accumulation container 27. After performing this control for a preset control time, the process returns to step S11.

  If it is determined in step S13 that the vehicle is in a braking state (NO), the process goes to step S15, and the speed ratio Rg of the continuously variable transmission 22 is set to be positive with respect to the rotational speed Na of the axle 2. The gear ratio Rgm is switched to maximize the rotation speed Nb of the compressor 24. At the same time, when the positive displacement compressor 24 is driven, the on-off valve control of the suction valve and the discharge valve is performed at the timing of the second control method as shown in FIG. Thereby, the air A or the exhaust gas G is accumulated in the pressure accumulation container 27. After performing this control for a preset control time, the process returns to step S11.

  Thereafter, Steps S11 to S14 or Steps S11 to S15 are repeatedly performed. If it is determined that there is no pressure accumulation request in the determination of Step S11 (NO), the process goes to Step S16 and the electromagnetic clutch 23 is disengaged. Return to return to the advanced control flow. Further, when the operation of the vehicle 1 or the engine 10 is stopped in the middle of the control, an interrupt is generated, the return is made and the control flow returns to the advanced control flow, and this control flow is ended at the end of the advanced control flow.

  2, in the vehicle gas pressure accumulation method for accumulating air A, exhaust G, or gas M, which is a mixture thereof, in the pressure accumulation container 27 mounted on the vehicle 1, the gas M is supplied to the pressure accumulation container 27. Is configured to be connectable to an axle 2 that travels the vehicle 1 (or a rotary drive shaft that transmits traveling torque to the axle 2), and in a vehicle traveling state. It is determined whether the vehicle is in a vehicle braking state. In the vehicle running state, the positive displacement compressor 24 is driven by the rotational torque of the axle 2, and in the vehicle braking state, the positive displacement compressor 24 is driven by the braking torque of the axle 2. Can be driven.

  According to the vehicle gas pressure accumulation system 20 and the vehicle gas pressure accumulation method of the present invention configured as described above, a vehicle gas pressure accumulation system for accumulating air A, exhaust G, or gas M, which is a mixture thereof, in the pressure accumulation container 27, and In the vehicle gas pressure accumulation method, the vehicle 1 accumulates pressure over a relatively long time in a normal traveling state, particularly in a traveling state close to a constant speed, thereby reducing driving work and minimizing deterioration in fuel consumption. When the braking energy of 1 can be used, the maximum braking energy that can be recovered by the positive displacement compressor 24 can be obtained by accumulating pressure with the maximum driving work.

1 Vehicle 2 Axle 3 Wheel 10 Engine (Internal combustion engine)
DESCRIPTION OF SYMBOLS 11 Exhaust passage 12 Exhaust branch passage 13 Gas cooler 14 Three-way valve 15 Air intake passage 16 Intake passage 20 Gas storage system 21 Gas introduction passage 22 Stepless transmission 23 Electromagnetic clutch 24 Positive displacement compressor (positive displacement compressor: gas filling device) )
25 Pressurized gas passage 26 Check valve 27 Accumulation vessel 28 Gas supply passage 29 Pressure adjustment valve 31 Oxygen concentration sensor 32 Container internal pressure sensor 33 Temperature sensor A Air G Exhaust gas Na Axle rotation speed Nb Volumetric compressor rotation speed Nem Engine rotation speed M Gas Mg Gear ratio setting map Pic Accumulated pressure lower limit pressure Pim In-vessel pressure Po Gas discharge pressure Po1 Set pressure Pmax Maximum combustion pressure Pmc Maximum allowable combustion pressure Pmin Minimum boost pressure Pr Residual pressure in accumulator container q Fuel Injection amount qm Fuel injection amount R1 determined by accelerator opening R1 Low rotation speed region R2 Medium / high rotation speed region Rg Gear ratio Rgm of continuously variable transmission Gear shift that maximizes the rotational speed of the displacement compressor relative to the rotation speed of the axle Ratio α Accelerator opening

Claims (3)

In a gas pressure accumulation system for a vehicle that accumulates air or exhaust gas or a gas mixture thereof in a pressure accumulation vessel mounted on the vehicle,
A control device comprising a gas filling device for filling the pressure accumulating vessel with gas, and having a vehicle state determination means for controlling the gas filling device and judging whether the vehicle is in a running state or a vehicle braking state. Prepared,
The gas filling device can be connected to an axle for running a vehicle or a rotary drive shaft for transmitting a running torque to the axle, and in the vehicle running state, the gas filling device is connected to the axle or the rotary drive shaft. The vehicle gas pressure storage system is configured so that the gas filling device is driven by the braking torque of the axle or the rotational drive shaft in a vehicle braking state. The gas filling device is composed of a positive displacement compressor,
The control device is
In the vehicle running state, the suction valve is opened during the movement from the top dead center to the bottom dead center of the piston of the positive displacement compressor, and the discharge valve is closed to suck the gas into the cylinder. During the movement from the bottom dead center to the top dead center of the piston, the suction valve is closed and the discharge valve is opened to discharge the gas.
In the vehicle braking state, the opening period of the exhaust valve is from a time point earlier than the top dead center to a time point earlier than the bottom dead center and before the exhausted gas flows backward, and the opening timing of the suction valve is 2. The vehicle gas pressure accumulation system according to claim 1, wherein the control is performed from a time point after the exhaust valve is closed to a time point later than the bottom dead center. In a vehicle gas pressure accumulation method for accumulating air, exhaust gas, or a gas mixture thereof in a pressure accumulation container mounted on a vehicle,
The gas filling device for filling the pressure accumulating vessel with gas is configured to be connectable to an axle for running the vehicle or a rotary drive shaft for transmitting running torque to the axle,
Determine whether the vehicle is running or braking,
In the vehicle running state, the gas filling device is driven by the rotational torque of the axle or the rotational drive shaft, and in the vehicle braking state, the gas filling device is driven by the braking torque of the axle or the rotational drive shaft. A method for storing gas in a vehicle.

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