JP3747832B2 - Vehicle with automatic engine stop function - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a vehicle that automatically stops an engine when stopping or decelerating.
[0002]
[Prior art]
A vehicle is known that automatically stops the engine when a predetermined engine stop condition is satisfied while the vehicle is stopped or decelerated, thereby suppressing fuel consumption and emission emission.
[0003]
[Problems to be solved by the invention]
In a vehicle that automatically stops the engine, auxiliary machinery such as a power steering pump and an air conditioner compressor cannot be driven using the engine output while the engine is automatically stopped. It is necessary to provide a separate motor and to drive these accessories using this accessory drive motor.
[0004]
However, at this time, as disclosed in Japanese Patent Laid-Open No. 11-147424, a state in which the steering is turned until the steering is locked (hereinafter referred to as a full turning state), that is, the power consumed by the power steering pump is maximum. If the rated output of the accessory drive motor is set so as to be able to cope with this situation, the power consumption of the accessory drive motor increases and the fuel consumption deteriorates.
[0005]
The present invention has been made in view of the technical problems of the prior art. In the above vehicle, the maximum value of the output required for the accessory drive motor is suppressed, and a motor with a low rated output is used as the accessory drive motor. An object of the present invention is to reduce the cost while reducing the power consumption during automatic engine stop.
[0006]
[Means for solving problems]
The first invention includes an engine, a hydraulic power steering device, a power steering pump that supplies hydraulic pressure to the power steering device, an auxiliary device, and an auxiliary device drive for driving the power steering pump and the auxiliary device when the engine is stopped. a motor, a drive mechanism for driving the power steering pump及beauty accessory in the output of the engine, automatically stops the engine when a predetermined engine stop condition is satisfied, the predetermined engine restart conditions are means for restarting the engine when a condition is satisfied, e Bei and means for detecting that the steering is steered, there before SL engine automatically stopped, and when the auxiliary machine is operating When the steering is steered, first, the auxiliary machine is stopped, the engine is restarted while the auxiliary machine is stopped, and the engine is restarted. An engine automatic stop function vehicle, characterized in that restarting the auxiliary stops the said accessory drive motor if it is moving.
[0007]
According to a second invention, in the first invention, the drive mechanism drives the power steering pump and the auxiliary machine with the clutch interposed between the engine and the power steering pump and the auxiliary machine, and the output of the engine. The clutch is engaged when engaged, and when the power steering pump and accessory are driven by the output of the accessory drive motor, the clutch is disengaged.
[0008]
According to a third aspect , in the second aspect , when the engine is automatically stopped, the clutch is released, and when the engine is restarted from the engine automatic stop state, the engine rotational speed reaches a predetermined idle rotational speed. When raised, the clutch is engaged.
[0009]
According to a fourth invention, in the first invention, the drive mechanism includes a one-way clutch interposed between the power steering pump and the auxiliary machine and the engine, and the one-way clutch outputs the power steering pump and the power steering pump at an output of the engine. When the accessory is driven, it is in a locked state, and when the power steering pump and the accessory are driven by the output of the accessory drive motor, the accessory is in a free state.
[0010]
According to a fifth invention, in the first to fourth inventions, a motor generator is connected to the engine, and when restarting the engine, the motor generator is used to crank the engine, The engine is restarted.
[0011]
A sixth aspect of the invention is characterized in that, in the first to fifth aspects of the invention, the auxiliary machine is an auxiliary machine that is driven as necessary and has nothing to do with the traveling function of the vehicle.
[0012]
According to a seventh aspect , in the sixth aspect , the auxiliary machine is an air conditioner compressor.
[0013]
[Action and effect]
Therefore, in the vehicle with the engine automatic stop function according to the present invention, when a predetermined engine stop condition is satisfied and the engine is automatically stopped, the engine accessories such as the power steering pump and the compressor of the air conditioner are driven by the accessory drive motor. Is done.
[0014]
Because the power consumed by the power steering pump during steering is large, if the steering is started when the auxiliary machine is operating while the engine is automatically stopped, the engine is restarted and the auxiliary machine is temporarily stopped. The When the engine rotation rises, the accessory drive motor is stopped and the accessory is restarted.
[0015]
Scan tearing simultaneously actuating the auxiliary and power steering pump during steering and power consumption thereof is increased, the output required for the auxiliary drive motor is to increase, complement by performing control such as this The maximum value of the output required for the machine drive motor can be lowered, and a motor with a small rated output can be used. If the rated output of the accessory drive motor can be reduced, the power consumption can be reduced and the cost can be reduced.
[0016]
At this time, a clutch is interposed between the engine and the power steering pump and auxiliary equipment. When the power steering pump and auxiliary equipment are driven by the engine output, the clutch is engaged, and the power steering pump and auxiliary equipment are output by the output of the auxiliary driving motor. If the clutch is disengaged when driving the engine, the power drive pump and the auxiliary machine are driven by the output of the auxiliary machine drive motor, and the engine does not rotate. An increase in electric power is suppressed ( second invention).
[0017]
In addition, when the engine is restarted, the clutch is engaged when the engine speed increases to a predetermined speed, for example, the idle speed, and thereafter the power steering pump and the auxiliary machine are driven by the engine output. The output of the machine drive motor is not used to increase the engine rotation, and the power steering pump can be driven with the output required at the steering angle at that time, and the steering force can be kept constant ( third invention).
[0018]
Alternatively, instead of the clutch, a power steering pump and an auxiliary machine may be driven by the output of the engine by providing a one-way clutch between the power steering pump and the auxiliary machine and the engine ( fourth invention). Even with such a configuration, the engine does not rotate when the power drive pump and the auxiliary machine are driven by the auxiliary drive motor, and it is not necessary to engage or disengage the clutch. Can be reduced.
[0019]
Furthermore, when a motor generator is connected to the engine and the engine is restarted when the engine is restarted, the engine is restarted by restarting the engine. Can shorten the time until the rotation speed rises. The shorter the start-up time, the smaller the steering amount until the engine is started and the power consumption of the power steering pump, so the maximum output required for the accessory drive motor can be kept low (No. 1) 5 invention).
[0020]
The auxiliary machine that is temporarily stopped is not required for securing the traveling function of the vehicle, and is an auxiliary machine that is driven as necessary, for example, an air conditioner ( sixth and seventh inventions). . Such an auxiliary machine is not required for securing the traveling function of the vehicle, so that no particular problem occurs even if it is temporarily stopped. Further, even if the air conditioner is temporarily stopped at the time of steering, the influence on the in-vehicle temperature is so small that the driver does not care.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[0022]
FIG. 1 shows a schematic configuration of an engine automatic stop vehicle to which the present invention is applied. A motor generator 2 is mechanically connected to the engine 1, and the engine 1 and the motor generator 2 further include a torque converter 3, an automatic transmission 4, a propeller shaft 5, a rear wheel differential 6, and a rear wheel drive. The shaft 7 is connected to the rear wheel 8.
[0023]
The motor generator 2 is an AC rotary electric machine, for example, a three-phase AC synchronous motor, and is used for assisting the engine output when starting (cranking) the engine 1 or accelerating or traveling uphill. Used to regenerate braking energy. The motor generator 2 is connected to the battery 10 via the inverter 9.
[0024]
A crank pulley 23 is connected to the crankshaft 1 a of the engine 1 via an electromagnetic clutch 22. The auxiliary pulley drive motor 31 is connected to the crank pulley 23 via a belt 24 and pulleys 25, 26, 27 and 28. A power steering pump 32 that supplies hydraulic pressure to the hydraulic power steering device 11, a transmission hydraulic pump 33 that generates hydraulic pressure to be supplied to the transmission 4, and a compressor 34 of the air conditioner 12 are connected.
[0025]
The accessory drive motor 31 is a DC motor and is connected to the battery 10. Although the rated output of the auxiliary drive motor 31 cannot cover the auxiliary power consumption when the steering is fully steered (mainly the power consumption of the power steering pump 23), the auxiliary power when the steering is not steered and the air conditioner is activated It is set to an output that can cover power consumption.
[0026]
With such a configuration, the power steering pump 32 and the like can be driven by the output of the engine 1 when the clutch 22 is engaged, and if the clutch 22 is released, the output of the auxiliary drive motor 31 can be achieved without causing the engine 1 to rotate. Thus, the power steering pump 32 and the like can be driven.
[0027]
The control of the engine 1, the motor generator 2, the auxiliary drive motor 31 and the like is performed by a control device 40 including a CPU, a ROM, a RAM, an input / output interface, and the like. The outputs of the engine 1 and the motor generator 2 are controlled so that the target driving force is realized.
[0028]
Further, the control device 40 automatically stops the engine 1 when a predetermined engine stop condition is satisfied when the vehicle is stopped, decelerated, or the like, and suppresses fuel consumption and emission emission. The engine stop condition is, for example, when the select lever is in the driving range, the vehicle speed is zero, and the brake pedal is depressed, and the battery 10 is sufficiently charged, and the brake booster negative pressure is developed more than a predetermined level. It is determined that the engine 1 and the transmission 4 have been warmed up. Further, when the predetermined engine restart condition is satisfied when the engine stop condition is satisfied and the engine is stopped, the engine 1 is automatically restarted.
[0029]
Further, while the engine 1 is in operation, the clutch 22 is engaged and the power steering pump 32 and the like are driven by the engine output. However, when the engine 1 is in the automatic stop state, the clutch 22 is released and power is supplied from the battery 10. In response, the power steering pump 32 and the like are driven by the accessory drive motor 31. With such a configuration, when the power steering pump 32 and the like are driven by the auxiliary drive motor 31, the engine 1 is not accompanied, and an increase in power consumption of the auxiliary drive motor 31 due to friction loss in the engine 1 can be suppressed. it can.
[0030]
Further, if the steering is steered while the auxiliary drive motor 31 is driving the power steering pump 32, the transmission hydraulic pump 33, and the air conditioner compressor 34, the output of the auxiliary drive motor 31 will compensate for the full steering. Since the machine power consumption cannot be covered, the control device 40 temporarily stops the air conditioner 12 to suppress the total power consumption of the auxiliary machine, and restarts the engine 1 during that time. Whether the steering is steered is determined based on the output signal of the steering angle sensor 51.
[0031]
FIG. 2 is a flowchart showing the contents of processing performed when the engine 1 is restarted from the engine automatic stop state, and is repeatedly executed by the control device 40 during the engine automatic stop.
[0032]
According to this, first, in step S1, it is determined whether or not the vehicle is in an engine automatic stop state. If it is determined that the engine is automatically stopped, the process proceeds to step S2, and if not, the process ends.
[0033]
In step S2, the clutch 22 is released, and the power steering pump 32, the transmission hydraulic pump 33, and the air conditioner compressor 34 are driven by the output of the accessory drive motor 31.
[0034]
In step S3, it is determined whether a predetermined engine restart condition is satisfied. This engine restart condition is, for example, when the vehicle speed is zero and the brake is depressed, the select lever is operated from the neutral range to the travel range, the accelerator pedal is depressed, and the charge amount of the battery 10 decreases. Or when the oil temperature of the engine 1 and the transmission 4 has decreased to a predetermined low temperature.
[0035]
When it is determined that the engine restart condition is satisfied, the process proceeds to steps S8 and S9 to start the motor generator 2, thereby cranking the engine 1, and at a predetermined timing, for example, the rotation speed of the engine 1 is a predetermined rotation. At the timing when the speed is reached, fuel injection and ignition are started and the engine 1 is restarted. Then, when the engine 1 starts the self-rotation and reaches the idle rotation speed, the clutch 22 is engaged in step S10, and the accessory drive motor 31 is stopped in step S11.
[0036]
On the other hand, if it is determined in step S3 that the engine restart condition is not satisfied, the process proceeds to step S4, where it is determined whether steering is performed based on the output of the steering angle sensor 51. If steering is detected, the process proceeds to step S5, and if not detected, the process ends.
[0037]
In step S5, it is determined whether the air conditioner 12 is operating. If it is determined that the air conditioner 12 is in operation, the process proceeds to step S6 to stop the air conditioner 12 and then proceeds to step S6. Otherwise, the process proceeds to step S7 while maintaining the stopped state of the air conditioner 12.
[0038]
In step S7, in order to cope with the power consumption of the power steering pump 32 that increases as the steering angle of the steering increases, the output of the auxiliary drive motor 31 is output at a predetermined increase rate, for example, a response of 6 kW / second or more. Raise. At the same time, the motor generator 2 is powered to start cranking of the engine 1 (step S8), and fuel injection and spark ignition to the engine 1 are performed at a predetermined timing, for example, when the rotation speed of the engine 1 is increased to a predetermined rotation speed. The engine 1 is restarted (step S9). Since the motor generator 2 is a motor having a relatively large rated output that can also be used for assisting the engine torque, the engine speed is instantaneously increased to a predetermined speed by cranking the engine 1 by the motor generator 2. The engine 1 is restarted within a short time.
[0039]
Thereafter, the clutch 22 is engaged at a timing when the rotational speed of the engine 1 reaches the idle rotational speed (step S10), the auxiliary machine drive motor 31 is stopped, and the air conditioner 12 is restarted (step S11). The time from when the air conditioner 12 is stopped after the start of steering turning until the air conditioner 12 is restarted is as short as about 0.3 seconds, and the temperature inside the vehicle due to the temporary stop of the air conditioner 12 is reached. There is almost no influence.
[0040]
Next, the effect | action by performing the said control is demonstrated. Here, the rated output of the accessory drive motor 31 is set to a value such as 2.5 kW so that a necessary output can be obtained when the air conditioner 12 is operating and the steering is not steered.
[0041]
First, FIG. 3 shows the output required for the accessory drive motor 32 when the engine 1 is automatically stopped while the air conditioner is stopped and the steering is not steered. In the figure, “P / S” and “AT” indicate the power steering pump 32 and the transmission hydraulic pump 33, respectively.
[0042]
In this case, only the initial hydraulic pressure required for the power steering pump 32 and the transmission hydraulic pump 33 needs to be ensured, so that the output required for the accessory drive motor 31 is suppressed to about 0.45 kW. In FIG. 3, the output required for the accessory drive motor 31 is set to 0.55 kW with some allowance, and the output required for the accessory drive motor 31 is also the same in other examples shown below. The margin is larger than the output actually required.
[0043]
FIG. 4 shows the output required for the accessory drive motor 31 when the air conditioner is operating and the engine 1 is automatically stopped when the steering is not steered. In the drawing, “A / C” indicates the air conditioner compressor 34.
[0044]
As described above, the rated output of the accessory drive motor 31 is set so that a necessary output can be obtained when the air conditioner 12 is operating and when the steering is not steered. Even if the output required for the machine drive motor 31 increases, it does not exceed the rated output of the accessory drive motor 31.
[0045]
FIG. 5 shows a case where the steering is steered while the engine is automatically stopped and the air conditioner is stopped. The cranking of the engine 1 by the motor generator 2 is started with the start of steering turning as a trigger, and the engine 1 is started. Further, since the power consumption of the power steering pump 32 increases as the steering angle increases, the output of the accessory drive motor 31 is increased at a predetermined increase rate accordingly. Furthermore, before the steering angle increases and the output of the auxiliary machine drive motor 31 cannot cover the auxiliary machine power consumption, the engine rotation is raised to idling rotation, and after the engine rotation has started, the auxiliary machine drive motor 31 is turned off. The power consumed by the auxiliary machine is covered by the output of the engine 1 after stopping.
[0046]
Therefore, the auxiliary drive motor 31 corresponds to the output required at an angle (about 105 degrees) that is steered for a short time (about 0.3 seconds) until the rotational speed of the engine 1 increases to the idle rotational speed. Since it should be possible, the maximum output value required for the accessory drive motor 31 can be kept below the rated output even during turning. At this time, by using the motor generator 2 to crank the engine 1, the time until the engine rotation rises can be reduced to a minimum, and the output required for the accessory drive motor 31 is sufficiently low. It can be suppressed.
[0047]
Further, since the clutch 22 is engaged at a timing when the engine rotation is increased to a predetermined rotation speed, for example, an idle rotation speed, the output of the auxiliary drive motor 31 is not used for increasing the rotation of the engine 1, and the power steering pump 32 can be driven more than the output required from the steering angle at that time, and the steering force of the steering can be kept constant throughout the engine restart.
[0048]
FIG. 6 shows a case where the steering is steered while the engine is automatically stopped and the air conditioner is operating. In this case as well, the engine 1 is restarted when the steering is steered. However, the power steering device 11 and the air conditioner 12 are simultaneously operated to increase the output required for the accessory drive motor 31. In order to suppress this, the air conditioner 12 is temporarily stopped. In this way, the total power consumption of the auxiliary machine is suppressed below the rated output of the auxiliary machine drive motor 31, and then the air conditioner 12 is restarted when the rotational speed of the engine 1 rises to the idle rotational speed. Stopped.
[0049]
As described above, when the steering is steered when the air conditioner is operated, the air conditioner 12 is temporarily stopped. However, during the time during which the air conditioner 12 is stopped, the engine starts its own rotation from the start of the steering and the rotation speed thereof. Therefore, the temporary stop of the air conditioner 12 has a negligible effect on the in-vehicle temperature.
[0050]
As described above, according to the present invention, when the steering is steered in the engine automatic stop state, the engine 1 is immediately started, the drive of the auxiliary device is switched to the drive by the engine 1, and the steering is steered when the air conditioner is operated. In this case, since the air conditioner 12 is temporarily stopped and the engine 1 is restarted, the maximum value of the output required for the accessory drive motor 31 can be reduced, and thereby the power consumption during the automatic engine stop And an inexpensive motor with a low rated output can be used as the accessory drive motor 31.
[0051]
Next, a second embodiment of the present invention will be described.
[0052]
FIG. 7 shows another configuration of the engine automatic stop vehicle to which the present invention is applied. In addition, about the structure same as previous embodiment, the same referential mark is attached | subjected and description is abbreviate | omitted.
[0053]
In this embodiment, a pulley 62 is provided on the output shaft 31 a of the accessory drive motor 31 via a one-way clutch 61. Further, a belt 63 is wound around the pulley 62 and the crank pulley 23, and a belt 64 is wound between the pulleys 25 to 28. Unlike the previous embodiment, no clutch is interposed between the engine 1 and the crank pulley 23.
[0054]
The one-way clutch 61 is a clutch that transmits torque only in one direction and does not transmit torque in the opposite direction, and drives the power steering pump 32, the transmission hydraulic pump 33, and the air conditioner compressor 34 with the output of the engine 1. In some cases, the locked state is set, but when these auxiliary devices are driven by the output of the auxiliary drive motor 31, the free state is set, so that the drive force is not transmitted from the auxiliary drive motor 31 to the engine 1.
[0055]
FIG. 8 is a flowchart showing the contents of the process performed when the engine 1 is restarted from the engine automatic stop state. The process in step S2 and the process of the previous embodiment in that there is no step S10 (FIG. 2). Is different. As described above, since the one-way clutch 61 is in a free state even when the accessory drive motor 31 is powered, the engine 1 is not rotated, so that the rotation between the engine 1 and the crank pulley 23 is prevented. This is because no clutch is provided for this purpose, and therefore, a process for releasing the clutch (step S2 in FIG. 2) is also unnecessary. Further, since the power steering pump 32 and the like can always be driven by the engine 1 by the one-way clutch 61, the process of engaging the clutch when driving the power steering pump 32 and the like with the engine output after the engine restart (FIG. This is because the second step S10) is also unnecessary.
[0056]
In addition, other processes such as restarting the engine 1 at the time of turning detection, or processing for temporarily stopping the air conditioner 12 until the rotation of the engine 1 starts up when the air conditioner 12 is operating at the time of turning detection, etc. Is the same as that of the previous embodiment, and in this embodiment, the same effect as that shown in FIGS. 3 to 6 can be obtained.
[0057]
Although the embodiment of the present invention has been described above, the above embodiment is merely an example of the configuration to which the present invention is applied, and is not intended to limit the scope of the present invention to the above configuration.
[0058]
For example, the belt may be hooked on each pulley in a manner other than that shown in FIG. The belt that synchronously rotates the pulley may be a plurality of belts. Also, the position where the clutch 22 is provided can be provided at other positions depending on how the belt is applied. An idle pulley may be provided between them if necessary.
[0059]
The same applies to FIG. 7, and the pulley 61 is provided on the output shaft of the accessory drive motor 31, but this is provided on the output shaft of the power steering pump 32, the transmission hydraulic pump 33 or the air conditioner compressor 34. Even if it does so, the same effect | action is acquired.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an engine automatic stop vehicle to which the present invention is applied.
FIG. 2 is a flowchart showing the contents of processing performed when the engine is restarted from the engine automatic stop state.
FIG. 3 is a time chart showing an output required for an accessory drive motor when the engine is automatically stopped when the air conditioner is stopped and the steering is not steered.
FIG. 4 is a time chart showing an output required for an accessory drive motor when the air conditioner is operating and the engine is automatically stopped when the steering is not steered.
FIG. 5 is a time chart showing a case where steering is steered while the engine is automatically stopped and the air conditioner is stopped.
FIG. 6 is a time chart showing a case where the steering is steered while the engine is automatically stopped and the air conditioner is operating.
FIG. 7 is a diagram showing a second embodiment of the present invention.
FIG. 8 is a flowchart showing the contents of processing performed when the engine is restarted from the engine automatic stop state in the second embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Engine 2 Motor generator 3 Torque converter 4 Automatic transmission 9 Inverter 10 Battery 11 Hydraulic power steering device 12 Air conditioner 22 Clutch 31 Auxiliary drive motor 32 Power steering pump 33 Transmission hydraulic pump 34 Air conditioner compressor 40 Control device 51 Steering angle sensor 61 One-way clutch

Claims (7)

Engine,
A hydraulic power steering device;
A power steering pump for supplying hydraulic pressure to the power steering device;
An auxiliary machine,
An accessory drive motor for driving the power steering pump and the accessory when the engine is stopped;
A drive mechanism for driving the power steering pump and the auxiliary machine with the output of the engine;
Means for automatically stopping the engine when a predetermined engine stop condition is satisfied, and restarting the engine when a predetermined engine restart condition is satisfied;
Means for detecting that the steering is steered;
With
When the steering is steered when the engine is in an automatic stop state and the auxiliary machine is operating, first, the auxiliary machine is stopped and the auxiliary machine is stopped. the engine is restarted, features and to Rue engine automatic stop function vehicles that restarting the accessory together with the engine stops the auxiliary machine drive motor if it is restarted. The drive mechanism is
A clutch interposed between the engine and the power steering pump and auxiliary equipment;
Means for fastening the clutch when driving the power steering pump and auxiliary machine with the output of the engine, and releasing the clutch when driving the power steering pump and auxiliary machine with the output of the auxiliary machine driving motor;
The vehicle with an automatic engine stop function according to claim 1 , wherein the vehicle has an automatic engine stop function. During automatic engine stop, release the clutch,
When restarting the engine from the engine automatic stop state, the clutch is engaged when the rotational speed of the engine rises to a predetermined idle rotational speed.
The vehicle with an engine automatic stop function according to claim 2 . The drive mechanism includes a one-way clutch interposed between the power steering pump and auxiliary machine and the engine,
The one-way clutch is in a locked state when driving the power steering pump and the auxiliary machine with the output of the engine, and is in a free state when driving the power steering pump and the auxiliary machine with the output of the auxiliary machine driving motor.
The vehicle with an engine automatic stop function according to claim 1 . A motor generator is connected to the engine, and when the engine is restarted, the engine is cranked using the motor generator, and the engine is restarted.
The vehicle with an automatic engine stop function according to any one of claims 1 to 4 . The vehicle with an automatic engine stop function according to any one of claims 1 to 5 , wherein the auxiliary machine is an auxiliary machine that is driven as necessary and has nothing to do with a traveling function of the vehicle. The vehicle with an automatic engine stop function according to claim 6 , wherein the auxiliary machine is an air conditioner compressor.

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