JP4910446B2 - Shift control device for automatic transmission - Google Patents

Description

  The present invention relates to a shift control device for an automatic transmission, and more particularly to a shift control device for an automatic transmission for a vehicle equipped with an engine with a supercharger.

  Conventionally, in shift control of an automatic transmission, attempts have been made to improve drivability by shifting the shift determination timing based on the vehicle speed and the accelerator opening. For example, Japanese Patent Application Laid-Open No. 57-195951 discloses a technology that shifts the vehicle speed to be shifted up when accelerating when the accelerator pedal is depressed to the high speed side to prevent the shift up and ensure acceleration. Are known.

Japanese Patent Laid-Open No. 2-197431 discloses a supercharging state detection for detecting a supercharging state of an engine in a vehicle equipped with a supercharged engine so as to obtain a shift characteristic corresponding to the operation of the supercharger. There is disclosed a shift control device for an automatic transmission that includes a means and a shift restricting means for restricting a shift-up operation when the boost pressure rises until the target boost pressure is reached (see FIG. 9).
JP-A-57-195951 JP-A-2-197431

  In a vehicle equipped with an engine with a supercharger, it is known in Patent Document 2 to perform shift control using a supercharging pressure linked to an engine load (≈ vehicle running resistance) in addition to the vehicle speed. If the up-shifting is only regulated until the supercharging pressure reaches the target supercharging pressure (abrupt increase according to the accelerator opening (see FIG. 6 of Patent Document 2)), the shift is performed after reaching the target supercharging pressure. There is a problem that a case where the driving force is insufficient occurs.

  For example, in the case of climbing with a constant accelerator opening as shown in FIG. 10 or when the gradient is lowered and the accelerator is returned during climbing as shown in FIG. Although the supply pressure catches up with the target supercharging pressure, it is possible to cause a situation where the driving force is insufficient due to a shift up even though the vehicle is still climbing. Even during acceleration or climbing, it is possible that the accelerator will return due to acceleration G or the vehicle body gradient without the driver's intention, and in this case as well, there is a possibility that the driving force will be insufficient due to upshifting. It can be said that there is.

  In addition, it has been proposed to detect or estimate a change in the running resistance of a vehicle from these values, such as a vehicle speed sensor, a throttle opening sensor, or a gradient sensor, and change the shift pattern. There is a problem of increasing the number of parts.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a shift control device for an automatic transmission for a vehicle equipped with an engine with a supercharger that can be realized with a simple configuration. There is to do.

  According to the first aspect of the present invention, there is provided a shift map including a shift line that is a boundary line between one shift stage and another shift stage, and the shift stage is determined based on the vehicle state and the current shift stage. A shift control means for selecting and controlling to the selected gear stage, and a shift control device for an automatic transmission connected to an engine with a supercharger, comprising a means for detecting a supercharging pressure; Provided is a shift control device for an automatic transmission characterized in that the shift to the high speed stage is inhibited while the supply pressure exceeds at least the first threshold value.

  According to the second aspect of the present invention, in the shift control device for an automatic transmission described above, after the supercharging pressure exceeds the first threshold value, the supercharging pressure is Even if it falls below the first threshold value, the control for suppressing the shift to the high speed side is continued, and the supercharging pressure is set to a second threshold value set lower than the first threshold value. A shift control device for an automatic transmission is provided in which the suppression of shift to the high speed side is released when the speed is lower than.

  According to the present invention, in a vehicle equipped with a combination of an engine with a supercharger and an automatic transmission, the supercharging pressure of the supercharger is maintained even when the driver reduces the amount of depression of the accelerator pedal. Since shifting is not performed while the first threshold value is exceeded, a decrease in engine torque due to a decrease in supercharging pressure and a decrease in torque transmitted due to clutch disconnection at the time of shifting do not occur, Shift shocks can be reduced, and a suitable shift control system can be constructed at low cost.

  Next, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

[First Embodiment]
FIG. 1 is a schematic diagram showing a schematic configuration (AMT system) of a vehicle to which the present invention can be applied. Referring to FIG. 1, an ECU (transmission control device) 1, an engine 2 having a supercharger 21, a transmission (T / M) 3, and a clutch 4 are shown.

  The ECU 1 includes an engine speed sensor 11, a turbine boost pressure sensor 12, an output speed sensor 13 that detects the speed of the output shaft of the transmission (T / M) 3 and extracts a vehicle speed signal, an accelerator opening sensor 14, A computer for controlling the engine 2, the transmission (T / M) 3, and the clutch 4 including a (shift) map 15 including a shift line that is a boundary line between one shift stage and another shift stage. It is.

  FIG. 2 is a diagram showing an outline of shift lines (upshift shift lines) included in the (shift) map 15 of the ECU 1. For example, during traveling at the Nth gear position, the ECU 1 determines to maintain the current gear position when the vehicle speed V and the accelerator opening T are in the left region of the shift line indicated by the solid line in the figure. When the vehicle speed V and the accelerator opening T reach the right side across the shift line, it is determined that a shift to the (N + 1) th shift stage is necessary.

  If it is determined that an upshift is necessary, the ECU 1 drives the clutch actuator to release the clutch 4, and drives the throttle actuator on the engine 2 side to close the throttle valve. Subsequently, the ECU 1 appropriately drives the transmission actuator on the transmission (T / M) 3 side, switches the gear train (shift stage), and connects the clutch again to complete the upshift.

  Next, the operation of this embodiment will be described in detail with reference to the drawings. FIG. 3 is a flowchart showing the flow of processing executed at predetermined time intervals in the ECU 1. Referring to FIG. 3, the ECU 1 determines whether or not the boost pressure value input from the turbine boost pressure sensor 12 exceeds a predetermined threshold value (threshold value 1) (step S001).

  Here, when the supercharging pressure value does not exceed the predetermined threshold value (threshold value 1) (NO in step S001), the ECU 1 normally performs shift control (shift stage maintenance / upshift / Downshift) is executed (step S007).

  On the other hand, when the supercharging pressure value exceeds a predetermined threshold value (threshold value 1) (YES in step S001), the ECU 1 shifts to a shift restriction mode that maintains the current shift speed (step S002), and the timer is added. Is started (step S003).

  As long as the supercharging pressure value exceeds the predetermined threshold value (threshold value 1), addition of the timer is continued, and when the timer exceeds the predetermined value (YES in step S004), or the vehicle speed reaches the predetermined value. When the speed exceeds the sufficient speed (YES in step S005), the timer is cleared and the shift restriction mode ends.

  FIG. 4 is a diagram showing a period during which the upshift regulation is continued by the shift control. The difference from FIG. 9 showing the conventional example is that, even after the supercharging pressure reaches the target supercharging pressure, the shift-up is restricted while the predetermined threshold (threshold 1) is exceeded. It is. Further, in the present embodiment, in the section where the supercharging pressure is equal to or less than a predetermined threshold value (threshold value 1), the shift-up restriction is not performed, but as is clear from the shift line in FIG. In the vehicle speed section, since it is rarely determined that the upshift is originally required, the driving force is not insufficient.

  In particular, the AMT system in which an automatic clutch mechanism and an automatic transmission mechanism are incorporated in the manual transmission illustrated in FIG. 1 and is electronically controlled does not include a torque converter, and thus has excellent transmission efficiency, but has a torque loss period during a shift. Although it has a feature of being long, by applying the present invention, it is possible to suppress a shift and secure a necessary torque in a scene where a driving force is required.

  Further, in the above-described embodiment, it has been described that in the shift restriction mode, the control to maintain the current shift stage is performed without referring to the (shift) map 15, but, for example, as shown in FIG. Similar control can also be realized by shifting the upshift shift line thus formed to the high speed side. Of course, in this case, since the accelerator opening is also referred to, it is possible to make a flexible determination according to the magnitude of the accelerator opening. In this case, it is also possible to increase the amount of movement of the shift line in accordance with the magnitude of the supercharging pressure and other vehicle conditions.

  Further, for example, as shown in FIG. 6, the same control can be realized by correcting the vehicle speed used for determining whether or not the shift is required, instead of shifting the upshift line stored in the ECU 1. Also in this case, since the accelerator opening is referred to, it is possible to make a determination according to the magnitude of the accelerator opening, and the correction amount of the vehicle speed can be set according to the magnitude of the supercharging pressure and other vehicle conditions. It is also possible to enlarge it.

[Second Embodiment]
Subsequently, a second embodiment of the present invention in which a change is made to the first embodiment will be described. In this embodiment, in addition to the threshold value for determining the gear position holding mode (threshold value 1), the threshold value for determining the gear position holding mode cancellation (threshold value 2; where threshold value 1> threshold value 2) is used. This is different from the first embodiment. Hereinafter, parts common to the first embodiment will be omitted, and the differences will be described in detail.

  FIG. 7 is a flowchart showing a flow of processing executed at predetermined time intervals in the ECU 1 according to the present embodiment. Referring to FIG. 8, the ECU 1 determines whether or not the boost pressure value input from the turbine boost pressure sensor 12 exceeds a threshold value (threshold value 1) for determining the gear position holding mode (step S101).

  Here, when the boost pressure value exceeds the threshold value for determining the gear position holding mode (threshold value 1) (YES in step S101), the ECU 1 sets 1 to the shift-up prohibition flag (step S102). .

  Then, while the shift-up prohibition flag is 1 (YES in step S105), control for maintaining the current gear position is performed (steps S002 to S006) as in the first embodiment described above.

  On the other hand, even when the boost pressure value is equal to or lower than the threshold value for determining the gear position holding mode (threshold value 1) (NO in step S001), the ECU 1 does not immediately clear the upshift prohibition flag. When the boost pressure value is below the threshold value for determining whether to hold the gear position hold mode (threshold value 2) (YES in step S103), the shift-up prohibition flag is cleared (= 0) (step S104).

  Therefore, whether or not to perform shift control (shift stage maintenance / upshift / downshift) using the normal shift line is determined by the value of the upshift prohibition flag. Specifically, the state where the upshift prohibition flag is 0, that is, the state where the boost pressure value does not exceed the threshold value for determining the gear position holding mode (threshold value 1) (the engine load is increasing but the vehicle speed is increased). Low state) or a state in which the boost pressure value is higher than the threshold value for determining the gear position holding mode (threshold value 1), but is equal to or lower than the threshold value for determining the gear position holding mode release value (threshold value 2) In this state, the shift control using the shift line (shift stage maintenance / upshift / downshift) is performed (step S007).

  FIG. 8 is a diagram showing a period during which the upshift regulation is continued by the shift control. The difference from the first embodiment is that the shift pressure holding mode release determination is performed even after the boost pressure reaches the target boost pressure and after the shift pressure hold mode determination threshold (threshold 1) or less. While this threshold value is exceeded, up-shifting regulation is continued, and this is suitably applied to an AMT system having a large torque loss period during shifting.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and a combination of an engine with a supercharger and an automatic transmission described in the claims. In the vehicle configuration, there is no particular limitation as long as the shift pattern for suppressing the shift to the high speed side is changed while the supercharging pressure exceeds at least a predetermined threshold value. For example, in the above-described embodiment, the shift control is performed regardless of the current shift speed. However, the control may be performed only at a specific low speed.

  For example, when a vehicle equipped with an automatic transmission is equipped with an acceleration sensor and a gradient sensor, these values are used to more accurately grasp the running resistance of the vehicle and increase or decrease the above threshold value. It is also possible to change the timing of shifting inhibition directly.

1 is a schematic diagram illustrating a schematic configuration of a vehicle to which the present invention is applicable. It is a figure showing an example of the shift line (upshift side shift line) included in the shift map. It is a flowchart showing the flow of the process performed in the transmission control apparatus which concerns on the 1st Embodiment of this invention. It is a figure for demonstrating the period when an upshift is controlled by the transmission control apparatus which concerns on the 1st Embodiment of this invention. It is a figure for demonstrating the example of the correction | amendment of the shift line (upshift side shift line) for achieving an upshift regulation. It is a figure for demonstrating the example of correction | amendment of the vehicle speed for achieving an upshift regulation. It is a flowchart showing the flow of the process performed in the transmission control apparatus which concerns on the 2nd Embodiment of this invention. It is a figure for demonstrating the period when an upshift is controlled by the transmission control apparatus which concerns on the 2nd Embodiment of this invention. It is a figure for demonstrating the period when an upshift is controlled by the conventional transmission control apparatus. It is a figure for demonstrating the conventional transmission control apparatus. It is a figure for demonstrating the conventional transmission control apparatus.

Explanation of symbols

1 ECU (transmission control device) 1
2 Engine
3 Transmission (T / M)
4 Clutch 11 Engine Speed Sensor 12 Turbine Supercharging Pressure Sensor 13 Output Speed Sensor 14 Accelerator Opening Sensor 15 (Shift) Map 21 Supercharger

Claims (4)

It has a shift map that includes a shift line that is a boundary line between one shift stage and another shift stage, selects a shift stage based on the vehicle status and the current shift stage, and controls to the selected shift stage A shift control device for an automatic transmission that includes a shift control means and is connected to an engine with a supercharger,
Means for detecting the supercharging pressure,
Inhibiting the shift to the high speed stage while the supercharging pressure exceeds at least the first threshold value;
A shift control device for an automatic transmission characterized by the above. It has a shift map that includes a shift line that is a boundary line between one shift stage and another shift stage, selects a shift stage based on the vehicle status and the current shift stage, and controls to the selected shift stage A shift control device for an automatic transmission that includes a shift control means and is connected to an engine with a supercharger,
Means for detecting the supercharging pressure,
While the supercharging pressure exceeds at least the first threshold value, the shift to the high speed side is suppressed, and
After the supercharging pressure exceeds the first threshold value, the control for suppressing the shift to the high speed side is continued even if the supercharging pressure falls below the first threshold value. And
Canceling the inhibition of shifting to the high speed stage when the supercharging pressure falls below a second threshold value set lower than the first threshold value;
Shift control apparatus for automatic transmission you characterized. The shift to the high speed side is suppressed or the suppression of the shift to the high speed side is canceled by correcting the shift line or the vehicle speed,
The shift control apparatus for an automatic transmission according to claim 1 or 2, wherein The automatic transmission is an automatic manual transmission (AMT) in which an actuator is attached to a manual transmission;
The shift control device for an automatic transmission according to any one of claims 1 to 3.

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