JP3959846B2 - Control device for automatic engine stop system of vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention automatically stops the engine when a predetermined stop condition including a condition that the shift position is a non-driving position is satisfied, and restarts the automatically stopped engine when a predetermined restart condition is satisfied. The present invention relates to a control device for an automatic engine stop system for a vehicle.
[0002]
[Prior art]
Conventionally, a vehicle has been proposed that is configured to automatically stop the engine when a predetermined stop condition is satisfied while traveling and to save fuel, reduce exhaust emission, or reduce noise. It has already been put into practical use (for example, JP-A-8-14076).
[0003]
As the stop condition when the engine is automatically stopped, for example, a predetermined condition such as vehicle speed zero, accelerator off, brake on, and the like is employed. In this case, if a predetermined condition is satisfied, the engine is automatically stopped when it is in a driving position such as “D” of the forward traveling position or “R” of the backward traveling position, and the automatic stopping is performed at the driving position. It is known that the automatic stop is performed only when the shift position is set to a non-drive position such as “N (neutral)” or “P (parking)” according to the driver's intention.
[0004]
In addition, the conditions for restarting the engine include, for example, a case where the driver indicates an intention to travel such as depressing an accelerator pedal, or a case where the shift position is changed from a non-driving position to a driving position. Further, the engine is restarted when any of the above-described stop conditions is released or when the battery charge amount SOC is insufficient.
[0005]
[Problems to be solved by the invention]
However, the automatic stop condition is satisfied by changing the shift position from the drive position to the non-drive position in this way, and conversely, the restart condition is changed by changing the shift position from the non-drive position to the drive position. In the case of a system that may be established, the detection of the shift position becomes very important.
[0006]
This is because in such a system, the automatic stop and automatic return (restart) of the engine are executed directly depending on the detection of the shift position.
[0008]
Even when the shift position has been detected, if the wrong signal is sent, or if multiple signals are detected at the same time, the automatic engine stop / return control can be performed properly. It may disappear.
[0009]
In addition, when the engine is restarted (unknown, as will be described later), when the shift position is in the non-drive position of the “N (neutral)” position or the “P” (parking) position; Rapid pressure increase in the operation of engaging a predetermined clutch (so-called forward clutch, etc.) of the automatic transmission when in a drive position such as “D” in the forward travel position or “R” in the reverse travel position A technique for changing whether or not to execute control (detailed later) has been proposed, but in such a system, if the shift position cannot be detected, the rapid pressure increase control cannot be executed properly. There is a risk that problems such as sluggishness at the time of starting will occur.
[0010]
The present invention has been made in view of such a conventional problem, and even if the shift position sensor does not operate normally, automatic stop or restart of the engine is improperly executed. It is an object of the present invention to provide a control device for an automatic engine stop system that can prevent such a situation.
[0011]
[Means for Solving the Problems]
The invention, together with the shift position is automatically stops the engine when including automatic stopping preconditions the condition that a non-drive position is established, the automatic stop the engine when a predetermined restart condition is satisfied In a control device for an engine automatic stop system for a vehicle to be restarted, precondition determining means for determining whether or not the automatic stop precondition is satisfied based on a signal from a sensor that detects the shift position, and the automatic stop precondition When it is determined that the condition is satisfied, sensor abnormality determination means for determining whether the detection signal of the sensor is normal, and even when it is determined that the automatic stop precondition is satisfied, If the detection signal is determined to be abnormal, the Rukoto which have a a stop means to stop the control for automatically stopping the engine, the above-mentioned problems Is that persists.
[0012]
Incidentally, means for determining whether the sensor for detecting the shift position is operating properly, detection signal is not the sensor is operating normally if (Claim 2), which is more simultaneously detected Judge that.
[0013]
Further, when the speed of the vehicle is detected to be equal to or higher than a predetermined value when the sensor detects a non-driving position such as a signal of the “N” position of the neutral position or the “P” position of the parking position (invoice) Item 3) or when the vehicle speed is not zero even though the shift position is “P” (Claim 4) , there is usually no possibility, and it is determined that the sensor is not operating normally.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0015]
FIG. 2 shows the drive system of this embodiment.
[0016]
In FIG. 2, 1 is an engine mounted on a vehicle, and 2 is an automatic transmission. The engine 1 has a motor generator 3 that functions as a motor and a generator for restarting the engine 1, and the crankshaft 1 a is connected to an electromagnetic clutch 26, a pulley 22, a belt 8, a pulley 23, and a speed reduction mechanism R. Are connected.
[0017]
The speed reduction mechanism R is a planetary gear type, includes a sun gear 33, a carrier 34, and a ring gear 35, and is incorporated between the motor generator 3 and the pulley 23 via the brake 31 and the clutch 32. The clutch 32 can be replaced with a one-way clutch.
[0018]
The oil pump 19 for the automatic transmission 2 is directly connected to the crankshaft 1a of the engine 1 as usual. As shown in the configuration surrounded by the imaginary line P, the oil pump 19 'is connected to the monitor generator 3 through the electromagnetic clutch 27, and the automatic transmission of oil is provided by the unique inlet pipe 24 and outlet pipe 25. It is good also as a structure which supplies to. In the automatic transmission 2, a known forward clutch C1 that is engaged during forward travel is provided.
[0019]
Reference numerals 11 and 16 in the figure denote auxiliary machines, which correspond to, for example, a power steering pump and an air conditioner compressor. The engine crankshaft 1a and the motor generator 3 are connected by pulleys 9 and 14 and a belt 8, respectively. It is connected.
[0020]
Although not shown in FIG. 2, in addition to the above-mentioned auxiliary machines, an engine oil pump, an engine water pump, and the like are also connected. Reference numeral 4 denotes an inverter electrically connected to the motor generator 3. The inverter 4 changes the rotation speed of the motor generator 3 by changing the supply of electric energy from the battery 5 as a power source to the motor generator 3 by switching. Further, switching is performed so that electric energy is charged from the motor generator 3 to the battery 5.
[0021]
Reference numeral 7 denotes a controller for performing on / off control of the electromagnetic clutches 26 and 27 and switching control of the inverter 4. As input signals to the controller, an on / off signal from the air conditioner SW42, an on / off signal of the automatic stop traveling mode (eco-run) SW40, an engine speed signal from the engine speed sensor 49, and a shift position of the shift lever 44 are input. Detection signal from the shift position sensor 45 to detect, signal from the engine coolant temperature sensor 47 that also functions as a sensor for estimating and detecting the oil temperature, vehicle speed signal from the vehicle speed sensor 50, foot brake from the foot brake sensor 51 A signal, a hand brake signal from the hand brake sensor 52, and the like are input.
[0022]
When the engine is automatically stopped, an indicator 46 for notifying the driver of the information and an indicator 48 for notifying the driver that the engine is not automatically stopped are provided.
[0023]
Next, the operation of this embodiment will be described.
[0024]
In the present embodiment, the control in the eco-run mode when the shift position sensor 45 is not operating normally will be described.
[0025]
The shift position signal is input from the shift position sensor 45 into the controller 7, and it is determined in the controller 7 whether or not the signal is appropriate (normal).
[0026]
Whether the shift position sensor 45 is operating normally is determined as follows, for example.
[0030]
First, it is confirmed whether or not a plurality of shift position detection signals are detected.
[0031]
As is apparent from the gate diagram of the shift position shown in FIG. 3, a plurality of shift positions cannot be selected at the same time. Therefore, when the input signal from the shift position sensor 45 to the controller 7 has a plurality of simultaneously detected, controller 7 determines that "the sensor is not working properly", and N G (No Good).
[0032]
As a cause in this case, failure of the sensor 55 itself, other poor signal line contact, and the like are conceivable.
[0033]
Secondly, it is determined whether there is a contradiction between the current vehicle status and the shift position detection signal.
[0034]
For example, when the vehicle is actually traveling in the “D” position and the vehicle speed is equal to or higher than a predetermined value, the signal of the “N” position or the “P” position is detected as “on”, and some failure occurs. It is thought that it has occurred.
[0035]
Similarly, when the shift position is “N” and the vehicle speed tends to increase significantly, it is considered that a failure has occurred. Also in such a case, the controller 7 determines that “the sensor is not operating normally” and sets it to NG.
[0036]
The shift position sensor 45 according to the two examples has been described above. However, the present invention is not limited to these examples. For example, when the vehicle speed is not zero even though the shift position is “P”, The shift position sensor 45 is not operating normally, for example, when the engine speed is zero even though “D” is “D” (in this embodiment, it cannot be automatically stopped at the “D” position). If it is considered, the controller 7 determines that the shift position sensor has failed, and thereafter stops the control for automatically stopping the engine.
[0037]
In this way, even if the shift position sensor 45 is in an abnormal state (fail), for example, the engine 1 can be prevented from being in a state where it cannot be restarted while being automatically stopped.
[0038]
In the present embodiment, for example, even when a failure is detected in relation to the “P” position, automatic stop control between “D” and “N” positions that are not related to the “P” position is also complete. Has been canceled.
[0039]
That is, when any abnormality is found (“when the shift position sensor 45 is not normal”), the engine is not automatically stopped.
[0040]
Here, for reference, a case where there is no failure in the shift position and the engine automatically stops normally will be described.
[0041]
When the engine 1 is automatically stopped, the controller 7 outputs a disconnection control signal to the electromagnetic clutch 26, and the pulley 22 and the engine 1 are in a power non-transmission state. On the other hand, since the air conditioner and the power steering are desired to be operated even when the engine 1 is stopped, the controller 7 is connected to the inverter 4 so that the motor generator 3 rotates with a torque that takes into account the load of the power steering pump and the air conditioner compressor. Corresponding switching signals are output.
[0042]
At this time, the brake 31 is turned off, the clutch 32 is turned on, and the electromagnetic clutch 26 is turned off. By setting it as such a state, the motor generator 3 and the pulley 23 will be in a direct connection state, and it can ensure the rotational speed required to drive the auxiliary machinery 11 and 16 grade | etc.,. In order to use the motor generator 3 as a generator or drive the auxiliary machinery 11, 16, etc. while the engine is in operation, the brake 31 is turned off, the clutch 32 is turned on, the electromagnetic The clutch 26 is kept on. By doing so, the motor generator 3 and the pulley 23 are directly connected to each other, and the motor generator 3 and the auxiliary machines 1 and 16 are prevented from exceeding the allowable rotation speed even when the engine rotation speed increases. Can do. Even if the clutch 32 is replaced with a one-way clutch, substantially the same operation as described above can be obtained.
[0043]
Further, when the engine 1 is returned, there are many engine restart conditions as described above. However, when the shift position is the “N” position, or when the battery charge capacity SOC decreases, etc. Except when there is no intention, it is necessary to engage the forward clutch C1 at the same time as restarting the engine so that traveling can be started immediately.
[0044]
This is to prevent the engine 1 from blowing up when the accelerator is depressed in a state where the forward clutch C1 is not engaged, and to eliminate the slack at the start.
[0045]
Therefore, rapid pressure increase control is performed in which the hydraulic pressure is rapidly increased temporarily for a predetermined time at the initial supply stage when the hydraulic pressure is supplied to the forward clutch C1.
[0046]
Here, a description will be given of a configuration in which the forward clutch C1 is engaged quickly and with a small engagement shock when the engine 1 is restarted from the automatically stopped state by appropriate rapid pressure increase control.
[0047]
In FIG. 5, the line pressure adjusted by the primary regulator valve 50 is finally supplied to the forward clutch C <b> 1 via the manual valve 54.
[0048]
Here, when the solenoid 60 is controlling the opening of the switching valve 58 in response to the rapid pressure increase control command from the controller 7, the line pressure PL that has passed through the manual valve 54 has passed through the large orifice 56, It is supplied to the forward clutch C1 as it is. Note that the accumulator 70 does not function due to the setting of the spring constant of the spring 74 when the rapid pressure increase control is being executed.
[0049]
Eventually, when the solenoid 60 receives the end command of the rapid pressure increase control from the controller 7 and controls the shutoff of the switching valve 58, the line pressure PL that has passed through the large orifice 56 is relatively slowly passed through the small orifice 64 to the forward clutch C1. Supplied (substantially the same route as before). At this stage, since the hydraulic pressure supplied to the forward clutch C1 is considerably increased, the hydraulic pressure in the oil passage 66 connected to the accumulator 70 moves the piston 72 upward in the drawing against the spring 74. As a result, while the piston 72 is moving, the increase in hydraulic pressure supplied to the forward clutch C1 is temporarily stopped, and the forward clutch C1 can complete the engagement very smoothly.
[0050]
FIG. 4 shows the hydraulic pressure supply characteristics of the forward clutch C1.
[0051]
In FIG. 4, the thin line indicates the case where the rapid pressure increase control is not executed, and the thick line indicates the case where it is executed. Further, a portion denoted by Tfast indicates a period (predetermined period) during which the rapid pressure increase control is executed. This period Tfast qualitatively corresponds to a period when a piston (not shown) of the forward clutch C1 packs a so-called clutch pack, and also corresponds to a period until slightly before the engine rotational speed reaches a predetermined idle rotational speed. . Tc and Tc ′ correspond to a period during which the clutch pack of the forward clutch C1 is packed.
[0052]
If the rapid pressure increase control is not executed, oil is supplied through a route that is substantially the same as the conventional one bypassing the switching valve 58. Therefore, a considerable time is required until the piston clutch pack of the forward clutch C1 is filled. Tc 'elapses, and the engagement is completed around time t2 following the course as shown by the thin line in the figure.
[0053]
As is clear from the display of FIG. 4, the start timing Ts of the rapid pressure increase control is set when the engine rotational speed NE reaches a predetermined value NE1. As described above, the reason why the rapid pressure increase control is not started simultaneously with the engine restart command Tcom is that the engine 1 slightly rises from a state where the rotational speed is zero (a state where the engine 1 rises to a value of about NE1). This is because the time T1 to become may vary greatly depending on the traveling environment. If the rapid pressure increase control is started at the same time as the engine restart command Tcom, the forward clutch C1 is sometimes engaged while the rapid pressure increase control is being executed. It may be completed and a very large engagement shock may occur. Therefore, avoiding immediately after restarting the engine with a large variation and setting the time Ts when the engine starts to rise slightly as the start timing of the rapid pressure increase control, the variation is small (stable) regardless of the driving environment. Oil supply control can be realized.
[0054]
However, as described above, this rapid pressure increase control is not always executed at the time of restart. For example, when the shift position is the “N” position, it is not necessary to engage the clutch in the first place. Not.
[0055]
Here, the “movement itself” between the “N” position and the “D” position is not problematic because it is mechanically executed in conjunction with the movement of the shift lever 44, but electrical detection of the shift position. If it is not possible, there is a possibility that a situation where the rapid pressure increase control is not executed may occur. In such a case, not only is the vehicle swayed at the start, but when the accelerator is depressed, the engine 1 is blown up.
[0056]
In this embodiment, when it is determined that the shift position sensor 45 is not operating normally for some reason, the automatic stop of the engine 1 is stopped, and the eco-run mode in which the automatic stop / restart of the engine is repeated is not entered. Therefore, such a problem can be dealt with without causing any inconvenience.
[0057]
Next, the flowchart of this embodiment is demonstrated.
[0058]
In FIG. 1, in step 20, input signals from various sensors are processed. For example, it receives signals such as shift position and vehicle speed.
[0059]
Next, in step 30, it is determined whether a precondition for automatically stopping is satisfied. For example, the vehicle speed is zero, the accelerator is off, the brake is on, and the shift position is “P” or “N”.
[0060]
In the present embodiment, since it is a control that executes an eco-run when it is detected that there is a shift position between “P” as the stop position and “N” as the neutral position, detection of the shift position is essential.
[0061]
When the precondition is not satisfied in step 30, the process proceeds to step 100 and the indicator 48 indicating that the engine automatic stop control is not executed is turned on.
[0062]
When the condition of step 30 is satisfied, the process proceeds to step 40, and it is determined whether or not the shift position sensor 45 is operating normally. The means and method for determining are as described above.
[0063]
If it is determined here that the shift position sensor 45 is not normal, the engine automatic stop control is not executed (eco-run is not performed), the execution of the engine automatic stop control is stopped, and the routine proceeds to step 100.
[0064]
If it is determined in step 40 that the shift position sensor is normal, the process proceeds to step 60 where the shift position history is determined in the controller 7.
[0065]
This is because if the shift position is frequently changed between “N” and “R” within a certain period of time, it is often put in a garage. Since it is not appropriate to automatically stop the engine, the engine is controlled not to automatically stop. In other words, according to the shift history (including the concept of shift frequency), it is determined what conditions the vehicle is currently in (such as garage entry, normal travel, etc.) based on a map or the like, and the predetermined condition is After being established, the time is variably controlled until the automatic engine stop is started.
[0066]
Thereafter, in Step 70, it is determined whether or not the automatic stop start condition is satisfied, that is, whether or not the preconditions are continuously satisfied for a time set according to the shift history. Proceeding to 80, the engine is automatically stopped (eco-run), and the indicator 46 indicating that the engine is being automatically stopped is turned on to notify the driver.
[0067]
If the automatic stop start condition is not satisfied in step 70, the process returns to step 50, and the engine is not automatically stopped . 1 corresponds to the precondition determining means of the present invention, step 40 corresponds to the sensor abnormality determining means of the present invention, and step 50 corresponds to the canceling means of the present invention. .
[0068]
【The invention's effect】
According to the present invention, the signal of a sensor for detecting a shift position, when the automatic stop assumptions are determined to be satisfied, it is determined whether the sensor for detecting the shift position is operating properly, when the sensor for detecting of the shift position is determined not to operate normally, even if the automatic stop assumptions are determined to be satisfied, be discontinued et cholanic (control for automatically stopping the engine) Thus, even if the shift position sensor fails (failure), it is possible to prevent an inappropriate control from being executed, and to obtain an excellent effect that does not make the driver uneasy or uncomfortable.
[Brief description of the drawings]
FIG. 1 is a flowchart showing an example of a control flow of control at the time of engine restart of a vehicle according to the present invention. FIG. 2 is a system configuration diagram of a vehicle engine drive device to which the present invention is applied. FIG. 4 is a diagram showing the oil supply characteristics and the like of the forward clutch along the time axis. FIG. 5 shows a main part of the hydraulic control device for executing the rapid pressure increase control. Hydraulic circuit diagram [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Engine 2 ... Automatic transmission 3 ... Motor generator 4 ... Inverter 5 ... Battery 7 ... Controller 19 ... Oil pump 40 ... Eco-run SW
42 ... Air conditioner SW
44 ... Shift lever 45 ... Shift position sensor 46 ... Engine automatic stop indicator 47 ... Engine cooling water temperature sensor 49 ... Engine speed sensor 50 ... Vehicle speed sensor 51 ... Foot brake sensor 52 ... Hand brake sensor R ... Deceleration mechanism

Claims (4)

An engine of a vehicle that automatically stops the engine when an automatic stop precondition including a condition that the shift position is a non-driving position is satisfied, and restarts the engine that is automatically stopped when a predetermined restart condition is satisfied In the control device of the automatic stop system,
Precondition determining means for determining whether or not the automatic stop precondition is satisfied by a signal from a sensor that detects the shift position;
Sensor abnormality determining means for determining whether or not the detection signal of the sensor is normal when it is determined that the automatic stop precondition is satisfied;
Even if it is determined that the automatic stop precondition is satisfied, if the detection signal of the sensor is determined to be abnormal, the vehicle has stop means for stopping the control for automatically stopping the engine. Control device for automatic engine stop system. In claim 1,
The control device for an automatic engine stop system for a vehicle, wherein the sensor abnormality determination means determines that the sensor is not operating normally when a plurality of detection signals from the sensor are detected simultaneously. In claim 1,
The sensor abnormality determination means determines that the sensor is not operating normally when the speed of the vehicle is detected to be equal to or higher than a predetermined value when the sensor detects a non-driving position. A control device for an automatic engine stop system of a vehicle. In claim 1,
The sensor abnormality determining means determines that the sensor is not operating normally when the vehicle speed is not zero although the shift position is a “P (parking) position” which is a stop position. A control device for an automatic engine stop system of a vehicle.

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