JP3657416B2 - Vehicle drive control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a drive control device for a vehicle that can alleviate a start shock when a shift range is switched from a non-travel range to a travel range.
[0002]
[Prior art]
For example, in a vehicle equipped with an automatic transmission such as that disclosed in Japanese Patent Application Laid-Open No. 61-105228, the shift range is switched from the neutral range (N range) to the drive range (D range) when starting, Hydraulic pressure is supplied to the clutch of the engagement gear, the clutch is engaged, and the driving force of the engine is transmitted to the wheels via the engagement gear at the time of starting. Normally, the driver switches from the N range to the D range and then depresses the accelerator to start the vehicle.
[0003]
[Problems to be solved by the invention]
However, it may be possible to switch from the N range to the D range while the accelerator is stepped on in the N range due to driver's carelessness. For example, without noticing that it is in the N range, just because the car that had stopped before suddenly started, suddenly stepped on the accelerator and then realized that the current range is the N range A situation of switching from the N range to the D range is conceivable.
[0004]
In such a case, since the clutch is engaged with the engine speed being high, there is a problem that the engagement shock increases.
[0005]
In view of the above circumstances, an object of the present invention is to provide a vehicle drive control device that can reduce the engagement shock when switching from the N range to the D range.
[0006]
[Means for Solving the Problems]
The invention of claim 1 includes a range detection means for detecting a shift range of the automatic transmission in a vehicle drive control device including an automatic transmission and capable of setting the throttle opening of the engine independently of the accelerator opening; An engine speed detecting means for detecting the engine speed; and when the range detecting means detects that the shift range is switched from the non-traveling range to the traveling range, the engine speed detecting means detects the engine speed. Is detected to be larger than a predetermined value, the throttle opening is set to be fully closed, and at the start, the clutch hydraulic pressure of the engagement gear of the automatic transmission is set to a predetermined value at which the clutch does not have a transmission capacity. From the state where the engine speed is greater than the predetermined value and lower than the predetermined value by the engine speed detecting means. During a predetermined time, the throttle opening is kept fully closed, and the clutch hydraulic pressure is increased to a hydraulic pressure obtained by adding a predetermined hydraulic pressure to the predetermined value having no transmission capacity, and the clutch hydraulic pressure is gradually increased after the predetermined time has elapsed. And a control means for setting the throttle opening to a predetermined limit value larger than zero until the clutch has a transmission capacity.
[0007]
According to this device, for example, when the engine speed is large at the time of switching from the N range to the D range, the throttle opening is fully closed and the engine speed is reduced regardless of the accelerator opening. Engage the clutch. Therefore, engagement of the clutch in a state where the engine speed is high can be avoided, and occurrence of engagement shock can be prevented. Specifically, for example, when the accelerator is depressed in the N range and then switched from the N range to the D range, the engine speed is decreased regardless of the accelerator depression, and then decreases to a certain level. Then, the clutch engagement operation is started. Therefore, the clutch is engaged when the engine speed is low, and the engagement shock is alleviated.
[0008]
Also, after waiting for a certain period of time for the engine speed to drop, the throttle opening is not maintained fully closed until the clutch has sufficient capacity, but a predetermined limit value greater than zero (corresponding to the accelerator opening) Set to a value smaller than the normal value). As a result, the driver can experience the rising sound of the engine speed according to the depression of the accelerator. Therefore, the time during which the throttle opening is unresponsive (fully closed) with respect to the depression of the accelerator is reduced, and it is possible to prevent a situation where the accelerator is further depressed by mistake due to the non-response. The driver's uncomfortable feeling during this period can be eliminated.
Then, when the engine speed becomes equal to or less than a predetermined value by fully closing the throttle opening, the clutch hydraulic pressure of the engaging gear at the time of starting is gradually increased to engage the clutch. During the time, the engine speed is sufficiently reduced by maintaining the throttle opening in a fully closed state. This is because if the engine speed is not sufficiently lowered and the throttle opening is returned to the original value (normal value corresponding to the accelerator opening) at the same time as the clutch hydraulic pressure rises, the engine will start before the clutch starts to have capacity. This is because the number of revolutions increases, causing control hunting. Therefore, the predetermined time is preferably set to be approximately the same as the time until the clutch starts to have capacity.
[0009]
According to a second aspect of the present invention, the predetermined time is a time for sufficiently reducing the engine speed by a throttle opening.
With this configuration, it is possible to maintain the engine speed that is sufficiently reduced by the throttle opening to some extent.
[0010]
According to a third aspect of the present invention, the limit value is a value that can inform the driver by a rising sound of the engine rotation that the engine rotation is responding to the accelerator.
With this configuration, even if the accelerator is stepped on suddenly, the throttle opening is limited. Therefore, the engine speed does not increase rapidly, and only the rising sound of the engine rotation is experienced by the driver.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, the configuration of the drive control apparatus of the embodiment will be described with reference to FIG.
This drive control device includes a clutch hydraulic pressure control means 2 for controlling the hydraulic pressure of the clutch 1 of the engagement gear at the start of the automatic transmission, and a throttle opening degree control means 4 for controlling the opening degree of the throttle 3 of the engine. The throttle opening control means 4 mainly controls the throttle opening in proportion to the accelerator opening, but can control the throttle opening independently of the accelerator opening as needed. is there.
[0012]
This drive control device further includes a range detection means 5 for detecting the shift range position selected by the driver, an engine speed detection means 6, and signals from these range detection means 5 and engine speed detection means 6. Control means 7 for inputting a control signal to the throttle opening control means 4 and the clutch hydraulic pressure control means 2.
[0013]
The control means 7 fully closes the throttle opening when the engine speed is greater than a predetermined value when the range detection means 5 detects that the shift range has been switched from the non-travel range to the travel range. In addition to setting, the clutch hydraulic pressure of the engaging gear at the time of starting is set to a predetermined value having no capacity. In addition, the throttle opening is kept fully closed and the clutch hydraulic pressure of the engagement gear at the start is maintained for a predetermined time from when the engine speed becomes equal to or less than a predetermined value because the throttle opening is fully closed. Is gradually increased to start the clutch engagement operation. Further, after the predetermined time has elapsed, the throttle opening is set to a predetermined limit value greater than zero until the starting engagement gear has capacity.
[0014]
Here, the configuration of the driving force transmission system in the vehicle of the embodiment will be briefly described. This driving force transmission system is of a parallel two-axis type as shown in FIG. 2, and the driving force of the engine is transmitted to the transmission input shaft X via the torque converter TC and the lockup clutch L. The transmission is transmitted from the machine input shaft X to the transmission output shaft Y via the clutch C. In the figure, Tt represents turbine torque, Tout represents output torque, Nout represents output shaft speed, and i represents a gear ratio.
[0015]
Next, the processing contents of the control means 7 will be described with reference to the flowcharts of FIGS. 3 and 4, the time chart of FIG. 5, and the characteristic diagram of FIG. When the control means 7 determines that the switching operation from the N range (non-traveling range) to the D range (traveling range) has been performed based on the detection signal of the range detection means 5, the control means 7 executes the flow of FIG.
[0016]
In this flow, first, in the first step S1, an engagement determination, that is, a determination process for determining whether or not the clutch of the engagement gear at start is engaged is executed. Next, the engine speed NE is checked in step S2. If the engine speed NE is less than or equal to the predetermined value NEINGX, that is, if the engine speed is not particularly high, the in-gear control from step S2 to step S5 is entered, and if NE is greater than the predetermined value NEINGX, that is, in the N range. When the engine speed is abnormally high, such as when the accelerator is depressed, the routine proceeds from step S2 to step S3, the timer tmNEXDL is set, and then the routine proceeds to step S4 to enter engine speed down control (NEDOWN control).
[0017]
The predetermined value NEINGX is the engine speed when the accelerator pedal is depressed in the N range (non-traveling range), and it is predicted that a shock will occur when the clutch is engaged together with the operation of the shift lever. For example, 3000 rpm.
[0018]
In the engine speed reduction control, as shown in FIG. 5, the throttle opening TH is set to “0”, regardless of the accelerator opening AP. At the same time, the clutch hydraulic pressure QON of the engaging gear at the time of starting is made to stand by at a predetermined value at which the clutch does not have a transmission capacity (range HA in FIG. 5).
[0019]
As the “predetermined value at which the clutch has no transmission capacity” in this case, a learned value learned in advance can be used, and this learned value can be obtained experimentally. For example, the clutch hydraulic pressure is gradually increased from zero while measuring the rotational speed on the input side and the rotational speed on the output side of the clutch. If there is no torque transmission via the clutch, the rotation speed ratio will be the same as when the clutch hydraulic pressure is zero, and if there is even a little torque transmission capacity, the rotation speed ratio will change. Learning, storing, and setting as a predetermined value. However, some margin is taken to learn the clutch hydraulic pressure just before the rotation change occurs. This is because it is necessary to set the clutch hydraulic pressure to ensure that the torque transmission capacity is zero, taking into account the effects of variations in individual clutches and the viscosity of the working oil (which depends on the oil temperature). is there.
[0020]
In a range where engine speed NE> NEINGX (HA range in FIG. 5), the process proceeds from step S2 to step S3 to step S4. When the engine speed NE becomes equal to or lower than NEINGX by the throttle opening fully closed control, the process proceeds from step S2 to step S5. At this time, the clutch hydraulic pressure is increased by one step (2-30% increase) and then enters the range of HB in FIG. Here, the reason why the clutch hydraulic pressure is increased by one step is that the learning value without the clutch transmission capacity is a value with some margin, so the clutch hydraulic pressure of about 20-30% of the predetermined value is set as the first step. Even if it is added, it has been experimentally confirmed in advance that there is no shock due to engagement of the clutch (a factor that the engine speed is sufficiently reduced). This is because it is better to increase the one-step clutch hydraulic pressure in order to shorten the time.
[0021]
Next, in the in-gear control in step S5, the flow of FIG. 4 is executed. When the in-gear control shown in FIG. 4 is entered, an engagement flag F-ENGAGE indicating the clutch engagement state is set to 1 in step S11 (this flag is engaged when the clutch is engaged, that is, the clutch of the engagement gear at the time of start is set to the transmission capacity. It is determined whether it is 1). Whether or not the clutch has sufficient torque capacity in this case (whether or not it is engaged) can be determined by comparing the rotational speeds of the clutch torque input side and output side. In a parallel two-shaft type transmission such as this device, it is possible to determine whether or not the rotational speed of the input shaft and the output shaft of the transmission has reached a rotational speed ratio corresponding to the gear ratio at the time of clutch engagement. it can.
[0022]
If not yet engaged, the engagement flag F-ENGAGE is “0”, so the process proceeds from step S11 to step S12. Here, the RD flag (R range → D range or D range to R range operation is switched). It is determined whether or not F-RD is 1). If YES, the process proceeds to step S14. If NO, it is determined in step S13 whether the timer tmNEXDL is counting. If it is counting, the process proceeds to step S14. Note that the time of the timer tmNEXDL is a time required to sufficiently reduce the engine speed at the throttle opening (necessary enough to start gradually grasping the clutch without a shock) and has been reduced. The engine speed is a time that can be maintained to some extent so that control hunting does not occur after the clutch is started.
[0023]
In step S14, the throttle opening TH is maintained at "0", and in step S15, a predetermined value tmNRD (AP) is set in the transition timer tmING. The predetermined value tmNRD (AP) in this case is a value depending on the accelerator opening AP, and a preset map value as shown in FIG. 6 is used. Next, the process proceeds from step S15 to step S18, the clutch hydraulic pressure QON is calculated, and the clutch hydraulic pressure is controlled to that value. In this case, the clutch hydraulic pressure QON is gradually increased and gradually brought to the clutch engagement level.
[0024]
By forcibly setting the throttle opening TH to zero as described above, the engine speed is sufficiently lowered to wait for a predetermined time set by the timer tmNEXDL. Then, when the timer tmNEXDL finishes counting, the determination in step S13 is NO, and the process proceeds to step S16. In step S16, the throttle opening TH is not fully closed, and is not returned to the normal value corresponding to the accelerator opening, but a value within a range with a predetermined limit lower than the normal value. (Range of HC in FIG. 5). That is, as the throttle opening TH, a limit value TH5DG that corresponds to the accelerator opening AP but does not become a value larger than the normal value is set.
[0025]
This limit value TH5DG (corresponding to a predetermined limit value greater than zero in the claim), if the throttle opening is zero and the engine speed does not increase regardless of the accelerator operation, the accelerator is accidentally depressed further. This is a value that is intended to prevent this by the rising sound of the engine rotation, and may be a value that can inform the driver by sound that the engine rotation is responding to the accelerator. Therefore, a throttle opening value within about 5 degrees may be given. In this control stage, even if the accelerator is stepped on suddenly, the throttle opening is limited. Therefore, the engine speed does not increase rapidly, and only the rising sound of the engine rotation is felt by the driver. As a result, it is possible to prevent the driver from feeling uncomfortable and to prevent the accelerator from being stepped on indefinitely. As the limit value TH5DG, a map value corresponding to the accelerator opening AP as shown in FIG. 6 is used.
[0026]
As shown in the map of FIG. 6, the timers tmNRD and tmNIG are set such that the longer the accelerator opening, the longer the time until the accelerator opening AP is greater than the predetermined accelerator opening. Then, a certain time is set. Further, as the value of the limit value TH5DG, a large throttle opening is set in the limited throttle opening until the predetermined accelerator opening AP, and a predetermined value (TH5DG = About 5 degrees) is set.
[0027]
In the next step S17, a predetermined value tmNIG (AP) is set in the transition timer tmING. The predetermined value tmNIG (AP) in this case is a value depending on the accelerator opening AP, and a preset map value as shown in FIG. 6 is used. Next, the process proceeds from step S17 to step S18, the clutch hydraulic pressure QON is calculated, and the clutch hydraulic pressure is controlled to that value. In addition, gradually increase the clutch hydraulic pressure, and restore the relationship between the accelerator opening and the throttle opening in a state where the torque is sufficiently transmitted through the clutch (that is, the clutch has a transmission capacity). . This is because, from the above state, even if the line pressure is increased, the torque transmission capacity hardly changes and there is no shock.
[0028]
Until the engagement flag F-ENGAGE becomes 1, processing is performed in the flow of steps S11 → 12 → 13 → 16 → 17 → 18, and when engagement is confirmed by the engagement flag F-ENGAGE = 1, the process proceeds from step S11 to step S20. Then, the clutch hydraulic pressure is set to the line pressure ATLINE pressure mode. Further, after waiting for the value of the timer tmING to become zero in step S21, the process proceeds to step S22, the in-gear flag F-INGEA is reset, and the process is terminated.
[0029]
To summarize the above, in the control of this device, when the engine speed is large when switching from the N range to the D range, the throttle opening TH is made zero regardless of the accelerator opening AP, and at the same time, the clutch hydraulic pressure QON is set. Set to zero. Then, after waiting for the set time (predetermined time) of the timer tmNEXDL for the engine speed NE to drop, the clutch hydraulic pressure QON is gradually increased and engaged. Also, until the clutch is engaged, the throttle opening TH is controlled by restricting the accelerator operation so that the engine operation can be recognized by the engine sound, and the throttle opening TH is suppressed until the engagement is confirmed. To return the throttle opening to the normal value corresponding to the accelerator opening.
[0030]
Accordingly, it is possible to avoid engagement of the clutch when the engine speed NE is large when switching from the N range to the D range, and it is possible to prevent the occurrence of an engagement shock, that is, a start shock. Further, although the clutch hydraulic pressure is increased after the predetermined time tmNEXDL has elapsed, the control hunting can be prevented by maintaining the throttle opening degree at the fully closed state at that stage. Further, since the throttle opening is set to the limit value TH5DG corresponding to the accelerator opening after the predetermined time tmNEXDL has elapsed until the clutch is engaged, the throttle opening TH is fully closed during that time. On the other hand, the driver can feel the connection between the accelerator and the throttle with the engine sound, and can prevent further erroneous accelerator depression. Therefore, drivability is also improved.
[0031]
【The invention's effect】
As described above, according to the first aspect of the invention, when it is detected that the shift range is switched from the non-traveling range to the traveling range, a state where the engine speed is greater than the predetermined value is detected. When the throttle opening is set to be fully closed and the engine speed is greater than a predetermined value, and it is detected that the engine speed has fallen below the predetermined value, the clutch of the engagement gear at start is Control means for setting the throttle opening to a predetermined limit value greater than zero until the transmission capacity is provided, so that the engagement shock when switching from the non-traveling range to the traveling range can be mitigated. . In particular, since the throttle opening is set to a predetermined limit value until the clutch has capacity after the engine speed is reduced, the driver connects the accelerator to the throttle with the engine sound. Can be sensed, and further erroneous accelerator depression can be prevented, thereby improving maneuverability.
In addition, since the control means maintains the throttle opening at a fully closed state for a predetermined time from when it is detected that the engine speed is greater than the predetermined value, it is less than the predetermined value. Can be achieved.
[0032]
According to the second aspect of the present invention, it is possible to maintain the engine speed sufficiently reduced by the throttle opening to some extent, so that it is possible to prevent control hunting at the beginning of clutch gripping from occurring. is there.
Further, according to the third aspect of the present invention, even if the accelerator is stepped on suddenly, the throttle opening is limited. Therefore, the engine speed does not increase rapidly, and only the rising sound of the engine rotation is experienced by the driver. Therefore, there is an effect that it is possible to prevent the driver from feeling uncomfortable and to prevent the accelerator from being depressed unnecessarily.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention.
FIG. 2 is a block diagram showing a schematic configuration of a driving force transmission system in the vehicle of the embodiment.
FIG. 3 is a flowchart showing a flow of processing executed by the control means 7 of FIG. 1;
4 is a flowchart showing details of in-gear control (step S5) in the flowchart of FIG. 3;
FIG. 5 is a time chart corresponding to the control flow of FIGS. 3 and 4;
6 is a characteristic diagram showing the contents of a map used in the control of FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Clutch 2 Clutch oil pressure control means 3 Throttle 4 Throttle opening degree control means 5 Range detection means 6 Engine speed detection means 7 Control means

Claims (3)

In a vehicle drive control device equipped with an automatic transmission and capable of setting the throttle opening of the engine independently of the accelerator opening,
Range detection means for detecting the shift range of the automatic transmission;
Engine speed detecting means for detecting the engine speed;
When it is detected by the range detection means that the shift range has been switched from the non-traveling range to the traveling range, if the engine speed detection means detects a state where the engine speed is greater than a predetermined value, the throttle The opening is set to be fully closed, and at the time of starting, the clutch hydraulic pressure of the engagement gear of the automatic transmission is made to wait at a predetermined value at which the clutch has no transmission capacity, and the engine speed is detected by the engine speed detection means. The throttle opening is maintained in a fully closed state for a predetermined time from when it is greater than the predetermined value, and when the predetermined value or less is reached, and the clutch hydraulic pressure is added to the predetermined value without transmission capacity. Until the clutch has a transmission capacity by gradually increasing the clutch hydraulic pressure after the predetermined time has elapsed. Serial drive control apparatus for a vehicle, characterized in that a control means for setting the throttle opening to a predetermined limit value greater than zero.   2. The vehicle drive control device according to claim 1, wherein the predetermined time is a time for sufficiently reducing the engine speed by a throttle opening.   2. The vehicle drive control device according to claim 1, wherein the limit value is a value capable of notifying a driver by a rising sound of engine rotation that engine rotation is responding to an accelerator.

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