JPH08105539A - Speed change control device for vehicular automatic transmission - Google Patents

Abstract

PURPOSE: To provide a speed change control device for a vehicular automatic transmission, which can reduce brake operations when a vehicle is running under a poor visibility, and can stably accelerate/decelerate the vehicle with an accelerator operated. CONSTITUTION: In the speed change control device for a vehicular automatic transmission, the device is equipped with a poor visibility running condition detecting means detecting a running condition under a poor visibility, and with a highest speed step prohibiting means prohibiting vehicle running by the step of gear shifting for the highest speed when a running condition under a poor visibility is detected. When a running condition under a poor visibility is detected at the time of running by the step of gear shifting for the highest speed, the highest speed step prohibiting means allows down shifting to be actuated from the highest speed step in response to brake actuation. Or when a running condition under a poorer visibility is detected, it is possible that the device is provided with a low speed shifting means which allows down shifting to be actuated to each step of gear shifting for lower speeds in response to brake actuation when the vehicle is running by each step of gear shifting for speeds other than the highest speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift control device for an automatic transmission for automobiles.

[0002]

2. Description of the Related Art In a vehicle equipped with an automatic transmission, from the viewpoint that the road surface frictional resistance coefficient decreases in rainy weather, the shift line is changed to a low vehicle speed side in rainy weather, and gear shifting is performed at a low vehicle speed side. Car swaying due to shifting on the high speed side,
To prevent the occurrence of spin etc. is disclosed in Japanese Patent Laid-Open No. 61-9974.
No. 8 publication.

[0003]

By the way, when the visibility in the front of the vehicle becomes poor, such as when driving in the rain, the most important thing is to secure the braking force. It is preferable to improve it. However, the device of the above publication is configured to allow the shift to the maximum speed stage even when the visibility in the front of the vehicle becomes poor as in the case of traveling in the rain, so that the driver can change the maximum speed stage. In order to suppress the increase in vehicle speed due to the upshift and the decrease in engine brake, frequent brake operation is performed, resulting in poor driving feeling and undesirable vehicle stability. . In view of the above problems, the present invention provides a shift control device for an automatic transmission for an automobile, which can reduce brake operation and perform stable acceleration / deceleration by accelerator work when traveling in a poor front view such as in rainy weather. is there.

[0004]

According to claim 1 of the present invention, as shown in FIG. 1 (a), an automatic transmission for an automobile which selects a speed stage in accordance with a running state of a vehicle and shifts the gear. And a poor visibility detecting means for detecting a traveling condition with poor visibility in front of the vehicle, and prohibiting traveling at the maximum speed stage when a traveling condition with poor visibility in front of the vehicle is detected. There is provided a gear shift control device for an automatic transmission for a vehicle, comprising: According to the second aspect, as shown in FIG. 1 (b), when a traveling state in which the field of view in front of the vehicle is poor is detected, the maximum speed stage inhibiting means responds to the brake operation to change from the maximum speed stage. A shift control device for an automatic transmission for a vehicle according to claim 1, wherein the shift control is performed for downshifting. According to claim 3, as shown in FIG. 1 (c), when a traveling state in which the field of view in front of the vehicle is poor is detected, the vehicle responds to the brake operation when traveling at a speed stage other than the maximum speed stage. Further, there is provided a shift control device for an automatic transmission for an automobile according to claim 1 or 2, further comprising a low speed shift means for downshifting to a speed stage where a lower speed engine brake is effective.

[0005]

According to the first aspect of the present invention, traveling at the maximum speed stage is prohibited when a traveling state in which the visibility in front of the vehicle is poor is detected. According to the second aspect of the present invention, when the traveling state in which the field of view in front of the vehicle is poor is detected, when the brake pedal is depressed, the downshift is performed from the maximum speed stage. According to claim 3, when a traveling state with poor visibility in the front of the vehicle is detected, even if the brake pedal is stepped on even when traveling at a speed stage other than the maximum speed stage, the speed stage at which engine braking at a lower speed side is effective. Downshifted to.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings. FIG. 2 schematically shows the configuration of an embodiment of the present invention. In FIG. 2, 1 is an engine and 2 is an engine.
Is an automatic transmission, 3 is built in the automatic transmission 2,
The vehicle speed sensor detects rotation of an output shaft (not shown) of the automatic transmission 2. Here, the automatic transmission 2 is a 4-speed automatic transmission, and is capable of traveling at the fourth speed stage which is the highest speed stage only in the D range. Reference numeral 4 is a brake pedal, 5 is a brake sensor attached to the brake pedal, and 6 is a wipe switch, which serves as a poor visibility detection means in the present invention.

Reference numeral 7 denotes an electronic control unit (hereinafter referred to as "ECU"), which includes a RAM 9, a ROM 10, a CPU 11 and an input port 1 which are interconnected via a bidirectional bus 8.
2, the output port 13, the drive circuit 14 and the like. In the present invention, the highest speed stage is prohibited based on the signal indicating the ON / OFF of the wiper switch 6 input from the input port 12, or at the lower speed side. Since it shifts to the speed stage where the engine brake works, it serves as the maximum speed stage prohibiting means and the low speed shifting means. Various signals, such as a signal indicating the throttle opening of the engine 1 and a shift position of the shift lever, are input to the input port 12.

3 and 4 are flow charts for explaining the operation of the first embodiment of the present invention. The first embodiment is
When the wiper switch remains high for more than a certain period of time, it is determined that the vehicle is in a poor visibility state, and the vehicle is prohibited from traveling at the highest speed stage, in this case the fourth speed stage, and downshifted to the third speed stage. It is a thing.

In step 101, the wiper switch 6
Is High, and the judgment result is YES.
If NO, the process proceeds to step 102, and if NO, the process jumps to step 108 to follow a step of performing a procedure for not performing the operation of prohibiting traveling at the highest speed stage. In step 102, it is determined whether or not the vehicle speed V is equal to or lower than a predetermined determination value VH for determining whether or not the vehicle is traveling at a predetermined high speed. If the determination result is NO, that is, if the vehicle is traveling at a high speed, Jump to step 108 and the judgment result is Y
If ES, go to step 103.

This is a case where it is judged whether or not the vehicle is traveling at a high speed, and when the vehicle is traveling at a high speed, the driver has a strong intention to drive at a high speed while setting the wiper switch to High. Therefore, in that case, the driver's will is respected and the downshift from the highest speed stage is not performed. In step 103, it is determined whether or not the vehicle is traveling in the D range. If the determination result is NO, the process jumps to step 108, and if YES, the process proceeds to step 104. This is because, in the embodiment of the present invention, the highest speed stage is possible only in the D range, and traveling in the highest speed stage is not possible outside the D range.

In step 104, the wiper switch 6
It is determined whether or not a flag XWPH indicating that is High is set. If the determination result is YES, the process directly proceeds to step 107. If the determination result is NO, the wiper switch 6 is determined in step 105. Is Hi
A timer TWP that measures the elapsed time since it was set to gh
H is reset to 0 (zero), measurement is started, the flag XWPH is set in step 106, and then the process proceeds to step 107. In step 107, the wiper switch 6 is set to Hi.
A timer TWP that measures the elapsed time since it was set to gh
It is determined whether or not the measured value of H has become larger than a preset value T1. If the determination result is YES, it is determined that the vehicle is in a poor visibility state and the process proceeds to step 109, and the determination result is NO. If so, jump to step 141.

In step 109, it is determined whether the maximum speed stage inhibition flag XNH is 0, that is, whether the control for inhibiting the maximum speed stage is not executed. at first,
Since Step 109 is determined to be YES, Step 1
10, the routine proceeds to step 110, where it is determined whether or not the vehicle is traveling at the fourth speed stage. Then, if it is determined at step 110 that the gear position is the fourth speed stage, the process proceeds to step 111, and if NO is determined, step 113 is performed.
The process proceeds to.

In step 110, YES, that is, the fourth
When it is determined that the vehicle is traveling at the speed stage and the routine proceeds to step 111, at step 111, for example, the engine is overrevised when the fourth speed stage is downshifted to the third speed stage based on the vehicle speed and the engine speed. If the engine does not overrev, it is determined in step 112 whether or not the brake operation is performed. If YES is determined in step 112, the process proceeds to step 115 to output a command to travel in the third speed stage, and in step 140, the flag XNH is set to 1 to execute the control for prohibiting the maximum speed stage. And returns. On the other hand, NO in steps 111 and 112.
If it is determined that the flag X
NH is cleared to 0 to indicate that the control for prohibiting the maximum speed stage is not executed, and the process returns.

As described above, when it is determined that the forward visibility is poor, the vehicle is traveling at the fourth speed stage, and if the engine does not overrev even if the engine is downshifted, the brake operation is performed when the brake operation is performed. In response to the operation, the vehicle is downshifted from the fourth speed stage, that is, the control for prohibiting the maximum speed stage is executed, and conversely, even if it is determined that the forward visibility is poor,
If the engine overrevs when the downshift is performed, or if the braking operation is not performed, the control for prohibiting the maximum speed stage is not executed and the downshift is not performed from the fourth speed stage.

On the other hand, if NO at step 110, that is, if the vehicle is not traveling at the fourth speed, the routine proceeds to step 113, at which it is judged that an upshift from the third speed to the maximum speed is required. JE
S, that is, if upshifting is about to be performed, this is stopped in step 114, and step 115
To output a command to run at the third speed stage, and
Proceeding to 40, the flag XNH is set to 1 and the process returns. If NO in step 113, the process directly proceeds to step 140, sets the flag XNH to 1, and returns. As described above, when the vehicle is not traveling at the fourth speed stage, the control for prohibiting the maximum speed stage is executed immediately when it is determined that the vehicle is in a traveling state with poor forward visibility.

If the flag XNH is set to 1 in step 140 and the control for prohibiting the maximum speed stage is being executed, the flow from the next time onward is from step 101 to step 101.
As long as all the judgments in 103 are established, step 10
If NO is determined in 9, the process proceeds to steps 113 and 114, and the same operation as described above is performed to continue the control for prohibiting the maximum speed stage.

As described above, in the first embodiment, when the vehicle is traveling at the maximum speed stage of the D range (the fourth speed stage) when the forward visibility is poor, even if the vehicle is downshifted to the third speed stage, overrev Otherwise, when the brake is depressed, the vehicle is downshifted to the third speed stage, and when traveling at the third speed stage, the upshift to the highest speed stage (fourth speed stage) is prohibited.

FIG. 5 is a flow chart of a second embodiment in which, when the engine brake is applied in all of the D range, the engine is operated so as to downshift to a speed stage where the engine brake is more effective in response to the brake operation. Is. This flowchart is different in steps 113 to 115 from the flowchart of the first embodiment shown in FIG. 4, but is otherwise the same. Therefore, FIG. 5 shows only the portions different from the first embodiment.

In the second embodiment, when the vehicle travels at the maximum speed stage of the D range (fourth speed stage) when the forward visibility is poor, the brake is applied if the vehicle does not overrev even if it is downshifted to the third speed stage. When stepping is performed, the routine proceeds from step 101 to step 112 common to the first embodiment to step 128 which performs the same operation as step 115 in the first embodiment, and a travel command at the third speed stage is issued and the third speed is issued. Downshifted. On the other hand, when the forward visibility is poor, the third speed stage, the second speed stage, the first speed stage other than the highest speed stage
When the vehicle travels at speed stages, in the second embodiment, the first
The determination of NO is made in step 109 or 110 common to the embodiment, and the process proceeds to step 121.

First, consider the case where the vehicle is traveling at the third speed stage. In step 121, whether the current speed V is lower than the maximum possible speed V2 of the second speed stage, that is, downshift to the second speed stage. Then, it is determined whether or not overrev is performed, and if the determination result is YES, the process further proceeds to step 122, where the speed V is greater than the maximum possible speed V1 of the first speed stage and the maximum possible speed V2 of the second speed stage. It is determined whether or not it is smaller, that is, whether or not the second speed is not overrev, and the first speed is overrev.

If YES at step 122, the routine proceeds to step 123, where it is determined whether or not the speed stage currently traveling is the third speed stage. Since it is considered, it is determined as YES in step 123, the process proceeds to step 124, and step 1
In 24, it is determined whether the brake is depressed,
If YES, it is determined that the driver wants to decelerate, the routine proceeds to step 129, where a command to travel at the second speed stage is issued, and a downshift from the third speed stage to the second speed stage is executed. .

On the other hand, if NO in step 121, it means that the vehicle is traveling at a speed that causes an overrev when downshifting to the second speed stage. Therefore, the process proceeds to step 128 to issue a command to drive in the third speed stage. Continue running at the 3rd speed stage. Also, if NO in step 124, overrev does not occur even if the vehicle travels at the second speed stage, but the driver does not want to decelerate.
Proceed to 28 to continue traveling at the third speed stage.

If the vehicle is traveling in the third speed stage at a speed that does not cause overrev even when traveling in the first speed stage, NO is determined in step 122 and step 125 is performed.
However, if it is confirmed in step 125 that the vehicle is traveling in the third speed stage, the process proceeds to step 124, and the downshift from the third speed stage to the second speed stage is executed as described above. . This is in addition to the above, from the third speed stage to the first
This is for prohibiting excessive deceleration due to one-step downshift to the speed stage.

Next, when the vehicle travels at the second speed stage and the traveling speed V does not overrev at the second speed stage but does overrev at the first speed stage, step 121,
In step 122, it is determined to be YES, and in step 123.
Proceed to step 1, but step 1
In No. 23, NO is determined, and the routine proceeds to Step 129, where the second
The traveling in the second speed stage is continued by commanding traveling in the second speed stage.

On the other hand, when the vehicle is traveling at the second speed stage, but the traveling speed V does not cause overrev even at the first speed stage, it is determined as NO at step 122, and the routine proceeds to step 125 and the vehicle is traveling at the third speed stage. Is determined. Since the vehicle is traveling at the second speed stage, NO is determined in step 125 and the process proceeds to step 126.
It is determined whether or not the vehicle is traveling at the speed stage. Since the vehicle is traveling at the second speed stage, YES is determined and the process proceeds to step 127 to determine whether or not the brake is depressed.

If the decision result in the step 127 is YES, it is decided that the driver wants to decelerate, and the step 13
0, a command to travel at the first speed stage is issued, and a downshift from the second speed stage to the first speed stage is executed. On the contrary, if NO in step 127, the vehicle does not overrev even if the vehicle travels in the first speed stage, but the driver does not want to decelerate. Therefore, the process proceeds to step 129 and the vehicle travels in the second speed stage. continue.

When traveling at the first speed stage,
When it is determined YES in step 121, NO in step 122, NO in step 125, and NO in step 126, the process proceeds to step 130 and a command to travel at the first speed stage is issued to continue traveling at the first speed stage.

At steps 128, 129, and 130, after issuing commands for traveling at the third speed stage, the second speed stage, and the first speed stage, respectively, the process proceeds to step 131, at which the number of speed stages currently in use is determined. After inputting and proceeding to step 140 in FIG. 4, the flag XNH is set to 1 to indicate that the control for prohibiting the maximum speed stage is being performed, and the process returns. As described above, in the second embodiment, when the vehicle travels at the maximum speed stage (fourth speed stage), the third speed stage, and the second speed stage of the D range when the visibility is poor, even if the vehicle is downshifted, overrev is required. If
When the brake is depressed, the vehicle is downshifted to the next lower speed stage.

In the above description of each embodiment, the wiper switch 6 is used as the poor visibility state detecting means, and when the wiper switch 6 is set to High for a predetermined time or more, it is considered that the running state is poor visibility. Although the downshift is controlled from other than the speed stage or the highest speed stage, it is also possible to perform the similar control by using other poor visibility state detecting means. For example, if the wiper switch 6 and the headlight switch (not shown) are turned on at the same time, or if a fog lamp (not shown) is turned on, or if a raindrop sensor (not shown) detects raindrops. It is also possible to assume that the vehicle is in a traveling state with poor visibility.

[0030]

According to the first aspect of the present invention, the vehicle is traveling at the maximum speed stage because the maximum speed stage is prohibited and the vehicle travels at a speed stage where engine braking is more effective when the vehicle is traveling in a poor visibility field. The responsiveness of the vehicle to the accelerator work of the driver is improved, the driving feeling is improved, the number of times the brake is depressed is reduced, and the stability of the vehicle is improved.
According to the second aspect, since the highest speed stage is prohibited when the brake is depressed, when the driver wants to decelerate, the vehicle automatically shifts to a speed stage where engine braking is more effective. However, since it is not performed when the driver does not want to decelerate because the brake is not depressed, a downshift contrary to the driver's intention is prevented and the driving feeling is further improved. According to the third aspect, the engine braking is effective in response to the brake operation, and the vehicle is automatically downshifted to a lower speed stage, so that the safety of the vehicle is further improved.

[Brief description of drawings]

FIG. 1 is a diagram showing a concept of control of a shift control device for an automatic transmission according to each claim of the present invention, in which (a) is the first claim;
The concept of control of the shift control device of the automatic transmission by
(B) is a diagram showing a concept of control of a shift control device for an automatic transmission according to claim 2, and (c) is a diagram showing a concept of control of a shift control device for an automatic transmission according to claim 3.

FIG. 2 is a diagram showing a configuration of a shift control device for an automatic transmission according to the present invention.

FIG. 3 is a flowchart of a control for prohibiting the maximum speed stage when the forward visibility is poor according to the first embodiment of the present invention.

FIG. 4 is a continuation of the flowchart of FIG.

FIG. 5 is a flowchart of control for downshifting to a lower speed stage due to poor front visibility according to the second embodiment of the present invention (only the portions different from FIGS. 3 and 4).

[Explanation of symbols]

 1 ... Engine 2 ... Automatic transmission 3 ... Vehicle speed sensor 4 ... Brake pedal 5 ... Brake sensor 6 ... Wiper switch 7 ... Electronic control unit

Claims (3)

[Claims] 1. A shift control device for an automatic transmission for an automobile, which shifts gears by selecting a speed stage in accordance with a running state of a vehicle, comprising: a poor visibility detecting means for detecting a running state in which a field of view in front of the vehicle is poor. A shift control device for an automatic transmission for an automobile, comprising: a maximum speed stage prohibiting means for prohibiting traveling at a maximum speed stage when a traveling state with poor visibility in front of the vehicle is detected. 2. The maximum speed stage prohibiting means downshifts from the maximum speed stage in response to a brake operation when a traveling state with poor visibility in front of the vehicle is detected. A shift control device for an automatic transmission for a vehicle as described above. 3. When a traveling state with poor visibility in front of the vehicle is detected, the vehicle is traveling at a speed stage other than the maximum speed stage, and in response to a brake operation, a lower speed stage in which engine braking is effective. The shift control device for an automatic transmission for an automobile according to claim 1 or 2, further comprising a low speed shift means for downshifting.