JPH06159495A - Shift control device for vehicle automatic transmission - Google Patents

Abstract

PURPOSE:To provide a shift control device which can perform economical running as possible as it can in accordance with an output characteristic of an individual engine on a vehicle in the case of selection of an economical running mode. CONSTITUTION:When a surging condition detecting means 50 detects occurrence of a surging condition in a vehicle which runs while an economical running shift chart is selected by manipulation of an economical running switch 48, the economical running shift chart is changed so as to carry out shifting at a higher speed. Further, if no surging condition is detected, the economical running shift chart is changed so as to carry out shifting at a speed lower than the previous speed, and accordingly, the shifting may be carried out at a minimum speed at which no surging condition of a vehicle occurs even though any unevenness is present among output characteristics of individual vehicle engines.

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 a vehicle.

[0002]

2. Description of the Related Art In an automatic transmission for a vehicle in which a gear ratio is automatically changed based on a throttle valve opening and a vehicle speed from a pre-stored shift map, an economical traveling mode is selected in advance by a selection operation means. When an economic travel shift map is selected from a plurality of stored shift maps, a shift control of a type that automatically changes the gear ratio of the automatic transmission based on the economical travel shift diagram. The device is known. For example, the shift control device disclosed in Japanese Utility Model Laid-Open No. 61-167758 is that.

[0003]

By the way, in the above-described conventional shift control device, generally, the shift diagram determined at the time of design is uniformly applied, so that the vehicle is driven with emphasis on fuel consumption. In order to prevent surging from occurring due to fluctuations in the engine rotation speed in a running vehicle, the shift map for economic travel in Fig. 1 provides a large margin from the surging occurrence limit in consideration of variations in the output characteristics of the individual engine of the vehicle. It is decided by. For this reason,
Even if the vehicle traveled on the economic travel shift map, it was not always possible to drive the vehicle with sufficient fuel efficiency.

The present invention has been made in view of the above circumstances, and an object of the present invention is to make possible as much as possible according to the output characteristics of the engine of each vehicle when the economical traveling mode is selected. An object of the present invention is to provide a shift control device capable of economical traveling.

[0005]

In order to achieve the above object, the gist of the present invention is to automatically change the gear ratio based on the throttle valve opening and the vehicle speed from a previously stored gear shift diagram. In the automatic transmission for vehicles that can be changed,
When an economical traveling shift map is selected from a plurality of pre-stored shift diagrams by operating the economical traveling selection means, the gear ratio of the automatic transmission is changed based on the economical travel shift diagram. A shift control device of a type that automatically changes, wherein: (a) the occurrence of a surging state of a vehicle is detected during traveling of the vehicle for which the economical travel shift diagram is selected by operating the economical travel selection means. And (b) the economical traveling speed change diagram is changed so that when the surging state of the vehicle is detected by the surging state detecting means, the vehicle shifts at a higher vehicle speed side than before. If the surging state is not detected, the shift diagram changing means for changing to shift to a lower vehicle speed side than before is included.

[0006]

According to this structure, the surging state detecting means detects that the surging state of the vehicle has occurred during the traveling of the vehicle for which the economical traveling shift diagram is selected by operating the economical traveling selecting means. Then, the shift line diagram changing means changes the shift line diagram for economical traveling so as to shift at a higher vehicle speed side than before, but if the surging state is not detected, the vehicle speed side is lower than before. The shift map for economical traveling is changed so that the shift is performed by.

[0007]

As described above, according to the variation of the output characteristics of the engine of each vehicle, the shift line diagram which emphasizes traveling economy is performed so that the shift is performed at the lowest vehicle speed at which the surging state of the vehicle does not occur. Since it is changed, it is possible to drive with emphasis on traveling economy by controlling the shift of the automatic transmission with a shift diagram that emphasizes traveling economy that matches the actual output characteristics of the engine, and to reduce fuel consumption as much as possible. Can be improved.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a vehicle power transmission device to which an embodiment of the present invention is applied. In the figure, the output of the engine 10 is the torque converter 1 with a lockup clutch.
2, the stepped automatic transmission 14, and a differential gear device (not shown) and the like, which are transmitted to the drive wheels.

The automatic transmission 14 is similar to what is known as a so-called A / T, and includes a plurality of sets of single pinion type planetary gear devices arranged coaxially and the planetary gear devices. A plurality of hydraulic friction engagement devices for engaging some of the components with each other or with the housing,
Further, the hydraulic friction engagement device is provided with an electronic control unit 16 described later.
Has two solenoid valves of an on-off operation type that are operated in accordance with a command from, and one of the first speed gear to the fourth speed gear is selectively established by a combination of operating states of the solenoid valves. A hydraulic control circuit 18 for changing the gear ratio γ is provided. The rotation speed of the input shaft 20 of the automatic transmission 14 is N _in and the rotation speed of the output shaft 22 is N _out.
Then, the speed change ratio γ is usually expressed as N _out / N _in .

The electronic control unit 16 includes a CPU 24 and a ROM
26, RAM 28, a so-called microcomputer including an interface (not shown) and the like.
A throttle sensor 32 that detects an opening of a throttle valve 30 that is provided in an intake pipe of the engine 10 and is opened and closed by operating an accelerator pedal (not shown), an engine rotation speed sensor 34 that detects a rotation speed of the engine 10, an automatic transmission 14 Gear stage sensor 36 for detecting the actual gear stage of
The operating position of the output shaft rotation sensor 38 for detecting the rotational speed of the output shaft 22 of the automatic transmission 14 and the shift lever 40, that is, the operating position for detecting one of the L, S, D, N, R and P ranges. From the sensor 42 and the travelability selection operation device 44 for selecting the travelability, the throttle valve opening TA
(%), A signal representing the engine speed N _e ,
A signal representing the actual gear stage G of the automatic transmission 14, a signal representing the output shaft rotation speed N _out , a signal representing the operating position P _s of the shift operating lever 40, and a signal representing the selected drivability D are respectively supplied. It has become so. Since the output shaft rotation speed N _out corresponds to the vehicle speed PS, the output shaft rotation sensor 38 also serves as a vehicle speed sensor.

When the power travel switch 46 is pressed, the travelability selection operation device 44 sets the content of the travelability D to a travel mode in which acceleration is emphasized, and the economical travel switch 48 is operated by pressing. If so, the content of the drivability D is set to the traveling mode with an emphasis on fuel consumption, and if neither the power travel switch 46 nor the economical travel switch 48 is pressed, the content of the drivability D is set to the normal travel mode. .

The CPU 24 of the electronic control unit 16 is R
Using the temporary storage function of the AM 28, the input signal is processed in accordance with the program stored in the ROM 26 in advance, the shift control of the automatic transmission 14 is executed, and the hydraulic control circuit 18 2
Controls the two solenoid valves for shifting.

In the ROM 26 of the electronic control unit 16,
For example, the shift diagram shown in FIG. 2 is stored in advance, and in the above shift control, it is calculated from the actual throttle valve opening TA and the output shaft rotation speed N _out from the shift diagram while the vehicle is traveling forward. Upshift or downshift is determined based on the vehicle speed PS. That is, the throttle valve opening TA indicating the actual traveling state in the shift diagram
When the point indicating the vehicle speed PS crosses the shift-up line indicated by the solid line, the shift-up is determined, and when the point indicating the vehicle speed PS crosses the shift-down line indicated by the broken line, the shift-down is determined. When the electronic control unit 16 determines upshifting or downshifting in this way, it outputs a shift command to the hydraulic control circuit 18 for switching to a gear higher or lower than the previous gear.
The shift diagram of FIG. 2 is a diagram for easy understanding, and is stored in the ROM 26 in the form of a data map.

In the ROM 26 of the electronic control unit 16,
In addition to the normal traveling shift diagram shown in FIG. 2, a power traveling shift diagram and an economical traveling shift diagram are also stored in advance, and the power traveling switch 46 of the drivability selection operation device 44 is stored.
Is operated, the power travel shift map is selected, and if the economical travel switch 48 is operated, the economic travel shift map is selected, and the automatic travel shift map is selected in accordance with the selected shift map as described above. The gear stage of the transmission 14 is controlled. The power travel shift line and the economic travel shift line are composed of shift lines that are shifted to the right and left sides of the shift line of the normal travel shift line of FIG. 2, respectively. When the switch 46 is operated, the vehicle can travel at a higher output than in normal traveling, and when the economical travel switch 48 is operated, the engine speed N _e is lower than that in normal traveling. Can run economically.

FIG. 3 is a functional block diagram for explaining an essential part of this embodiment, that is, an essential part of the control function of the electronic control unit 16 when the economical traveling switch 48 is operated. In the figure, a surging state detecting means 50 for detecting the occurrence of a surging state of the vehicle during traveling of the vehicle for which the economical traveling shift map is selected by operating the economical traveling switch 48, and the economical traveling shift diagram are shown. When the surging state of the vehicle is detected by the surging state detecting means 50, the vehicle is changed to shift at a higher vehicle speed side than before, and when the surging state is not detected, at a lower vehicle speed side than before. A shift diagram changing means 52 for changing the shift is provided. For this reason, when the surging state detecting means 50 detects that the surging state of the vehicle has occurred during traveling of the vehicle for which the economical traveling shift diagram is selected by operating the economical traveling switch 48, the shift diagram The changing means 52 changes the economical traveling gear shift diagram so as to shift on the higher vehicle speed side than before, but if the surging state is not detected, shifts on the lower vehicle speed side than before. Because the economic travel shift diagram is changed, the traveling economy is improved so that the shift is performed at the lowest vehicle speed that does not cause the surging state of the vehicle depending on the variation in the output characteristics of the engine of each vehicle. The emphasis shift diagram is changed.

FIG. 4 and FIG. 5 show an economic traveling shift diagram changing routine which is a main part of the control operation of the electronic control unit 16. In step SG1 in the figure, it is determined whether or not the economical traveling mode is selected by operating the economical traveling switch 48. If the determination in step SG1 is negative, the routine is terminated, but if the determination is affirmative, in the subsequent step SG2, it is determined whether or not the throttle valve opening TA is less than or equal to a predetermined determination reference value TAE. Is determined. The determination reference value TAE is a value for setting a range to be changed in the economic travel shift diagram shown in FIG. 6, for example, and is set appropriately.

If the determination at step SG2 is negative, this routine is ended, but if the determination is affirmative, at step SG3 that follows, is the vehicle speed PS below the predetermined determination reference value PS _sp ? It is determined whether or not. The determination reference value PS _sp is the vehicle speed corresponding to the portion corresponding to the actual throttle valve opening TA on the shift-up line for shifting up to the current gear. For example, if the throttle valve opening TA 6 is traveling in fourth gear be between TAE and TA _b, the TAE of the upshift line L ₃₄ to the fourth speed
And the corresponding vehicle speed portion located between the TA _b.

If the determination at step SG3 is negative, this routine is ended, but if the determination is affirmative, then at step SG4 the surging detection routine corresponding to the surging detection means 50 is executed,
Whether or not a surging state of the vehicle has occurred is detected. The surging detection routine will be described with reference to FIG.
In step SG4-1, volatility .DELTA.N _e of the engine rotational speed N _e is calculated from the following equation (1). In the following equation (1), MN _e is the lower peak value of the pulsating engine rotation speed N _e .

[0020]

[Number 1] _{ΔN e = (N e -MN e} ) / MN e ··· (1)

[0021] In step SG4-2, number of times per a predetermined time exceeds the engine rotational speed N criterion values S ₁ to volatility .DELTA.N _e is set in advance and _e are counted, the count value C is stored To be done. In step SG4-3, whether said count value C exceeds a predetermined criterion value C _s is determined. The judgment reference values S ₁ and C _s correspond to the count value C in a state where the passenger starts to feel the surging of the vehicle, for example, and are determined experimentally. The judgment reference value C _s may be a constant value, but it is better that it is a function of gear speed and vehicle speed.

If the determination in step SG4-3 is negative, the surging of the vehicle has not occurred, so the content of the flag F _surge is cleared to "0" in step SG4-4. Step SG4-
If the determination of 3 is affirmative, it means that the vehicle is surging, and therefore the content of the flag F _surge is set to "1" in step SG4-5. This flag F _surge indicates that the vehicle is in a surging state when the content is “1”.

Returning to FIG. 4, in step SG5, it is determined whether or not the content of the flag F _surge is "0". If the determination in step SG5 is affirmative,
Since the surging of the vehicle has not occurred, in step SG6, the shift point vehicle speed PS _sp is changed by the predetermined value ΔPS to a vehicle speed lower than the value up to that point according to the following equation (2). That is, the shift lines L ₃₄ and L _{43 of the} part to be changed are shifted from the position shown in the upper part of FIG. 7 to the position shown in the lower part.

[0024]

[Equation 2] PS _sp ← PS _sp −ΔPS (2)

On the other hand, if the determination in step SG5 is negative, it means that the vehicle is surging, and therefore, in step SG7, the shift point vehicle speed PS _sp is determined according to the following equation (3). The value 2ΔPS is changed to a higher vehicle speed side than the previous values. That is, the shift lines L ₃₄ and L _{43 of the} portion to be changed are shifted from the position shown in the upper part of FIG. 8 to the position shown in the lower part.
In the present embodiment, steps SG5 to SG7 correspond to the shift diagram changing means.

[0026]

[Formula 3] PS _sp ← PS _sp + 2ΔPS ・ ・ ・ (3)

As described above, according to the present embodiment, the surging state of the vehicle during traveling of the vehicle for which the economical traveling shift diagram is selected by the operation of the economical traveling switch 48 by the surging state detecting means 50. When the occurrence is detected, the shift diagram changing means 52 changes the shift diagram for economical traveling so as to shift at a higher vehicle speed side than before, but when the surging state is not detected, Since the economic travel shift diagram is changed to shift at a lower vehicle speed side than before, the lowest vehicle speed that does not cause the surging state of the vehicle depending on the variation of the output characteristics of the engine of each vehicle etc. The shift diagram is changed to emphasize traveling economy so that the shift can be performed at.
Therefore, depending on the variation in the output characteristics of the engine of each vehicle, the shift diagram will be changed to emphasize running economy so that the shift is performed at the lowest vehicle speed that does not cause the surging state of the vehicle. , By controlling the shift of the automatic transmission with a gear shift diagram that emphasizes traveling economy that matches the actual output characteristics of the engine, traveling that emphasizes traveling economy can be performed and fuel consumption can be improved as much as possible. . As shown in FIG. 9, the higher the gear speed is, the higher the fuel consumption is. Therefore, in the economical traveling selection state, it is preferable that the higher gear speed is used as much as possible in a range where surging does not occur.

Although one embodiment of the present invention has been described above with reference to the drawings, the present invention can be applied to other modes.

For example, in the above-described embodiment, the throttle valve opening TA is used, but instead of this, the accelerator pedal operation amount A _cc detected by the accelerator pedal operation amount sensor and its change speed VA _cc , intake air Negative pipe pressure and fuel injection amount may be used. In short, it is sufficient if the amount represents the required output of the vehicle.

Further, in the surging state detecting means 50 of the above-mentioned embodiment, the fluctuation rate ΔN of the engine rotation speed N _{e.
e [= (N e -MN e) /} MN e ] but it has been determined that the occurrence of surging of the vehicle with a possible number C exceeds the predetermined value S ₁ is higher than the criterion value C _s, the engine The output torque value from the engine 10 may be used instead of the speed N _e , or the surging of the vehicle may be detected based on a signal from a vibration sensor provided in the engine 10 or a power transmission system thereof. is there. Here, the surging of the vehicle is a vibration generated from the engine 10 when operating at a relatively low speed and a high load.

Further, MN _e in equation (1) for obtaining the fluctuation rate .DELTA.N _e may be a moving average value below the peak value of the predetermined time period, the amplitude of the engine rotation speed N _e pulsates It may be an average value.

Further, in the above-mentioned embodiment, FIG. 7 and FIG.
Have been displaced similarly down-shift line L ₄₃ with the upshift line L ₃₄ is also shown in the up-shift line L ₃₄
Only the shift may be allowed.

Further, in the above-described embodiment, the change of the portion of the upshift line L ₃₄ and the downshift line L ₄₃ between the third speed gear position and the fourth speed gear position after TAE has been described. , A part of the upshift line L ₃₄ and the downshift line L ₄₃ , for example, TA _a <TA <TAE or TA
Local changes may be made where _a <TA <TA _b , and upshift line L ₃₄ and downshift line L
_{In addition to 43,} for example, changes may be made to the upshift line L ₂₃ and the downshift line L ₃₂ between the second speed gear and the third speed gear.

Further, the automatic transmission 14 of the above-mentioned embodiment is
It was a stepped transmission equipped with multiple sets of planetary gears,
It may be a continuously variable transmission in which a transmission belt is wound around a pair of pulleys having a variable effective diameter. In short, the automatic transmission can select an economic traveling shift diagram in response to the operation of the economical traveling switch 48 and can change the gear ratio based on the shift diagram.

The above description is merely one embodiment of the present invention, and the present invention can be variously modified without departing from the gist thereof.

[Brief description of drawings]

FIG. 1 is a diagram showing a vehicle power transmission device to which a shift control device according to an embodiment of the present invention is applied.

FIG. 2 is a diagram showing an example of a shift diagram stored in advance in the electronic control device of FIG.

FIG. 3 is a functional block diagram illustrating an essential part of the operation of the electronic control device of FIG.

FIG. 4 is a flowchart illustrating a main part of control operation of the electronic control device of FIG.

5 is a flowchart illustrating in detail the surging detection routine of FIG.

FIG. 6 is a diagram showing a shift diagram for economical traveling, which is stored in the electronic control unit of the embodiment of FIG. 1.

7 is a diagram illustrating an operation of changing the shift line to a low vehicle speed side in the electronic control unit of FIG. 1 when a vehicle surge does not occur.

FIG. 8 is a diagram illustrating an operation of changing the shift line to a higher vehicle speed side in a state where a vehicle surge occurs in the electronic control device of FIG. 1.

9 is a rotation variation rate ΔN of the engine in the vehicle of FIG.
It is a figure explaining the relationship between _e and fuel consumption.

[Explanation of symbols]

 14: Automatic transmission 48: Economical traveling switch (economical traveling selecting means) 50: Surging state detecting means 52: Shift line diagram changing means

Claims (1)

[Claims] 1. An automatic transmission for a vehicle in which a gear ratio is automatically changed based on a throttle valve opening and a vehicle speed from a pre-stored shift map, and a plurality of pre-stored data are stored by operating an economical travel selecting means. A shift control device of a type that automatically changes the gear ratio of the automatic transmission based on the economical travel shift map when the economical travel shift diagram is selected from the various types of shift maps. And a surging state detecting means for detecting occurrence of a surging state of the vehicle during traveling of the vehicle for which the economical traveling shift diagram is selected by operating the economical traveling selecting means, and the economical traveling shift diagram. Is changed so that when the surging state of the vehicle is detected by the surging state detecting means, the vehicle is shifted to a higher vehicle speed side than before, and the surging state is not detected. The case than before the speed change control apparatus for a vehicular automatic transmission, which comprises a, a shift diagram changing means for changing to shift in the low vehicle speed side.