JP3412432B2 - Shift control device for automatic transmission for vehicle - Google Patents

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 automatically switching the shift speed of an automatic transmission for a vehicle.

[0002]

2. Description of the Related Art As one type of automatic transmission for a vehicle, engine braking is always effective in some of a plurality of automatically-shifted gears, for example, a fourth gear and a fifth gear. However, in other gears, for example, the first gear speed to the third gear speed, the engine braking is not effective because it is achieved by the engagement of the one-way clutch. For example, it is an automatic transmission of five forward speeds described in JP-A-8-246913.

For the above-mentioned automatic transmission for vehicles, a prohibition control may be provided for prohibiting or suppressing a predetermined gear stage when preset traveling conditions are satisfied for various reasons. For example, in order to obtain a driving force or an engine braking force when traveling uphill or downhill over a predetermined gradient, upshifting to a high gear side is prohibited, or the upshift line is moved to a high vehicle speed side so that the high gear Shifting point to higher speed uphill / downhill control, prohibiting upshifting to the higher gear to obtain engine braking force when the accelerator pedal, that is, the throttle valve is suddenly returned, or shifting upshift line Acceleration quick-close control to move to the vehicle speed side to increase the vehicle speed to the high-speed gear stage.Prohibit upshifting to the high-speed gear stage or raise the upshift line in order to obtain a surplus driving force during cornering. Cornering control to move to the vehicle speed side to increase the shift point vehicle speed to the high speed side gear speed.If the driver's driving direction is estimated and acceleration is directed, the high speed side gear is set. Driving direction estimation control that prohibits upshifting to the next gear or moves the upshift line to the higher vehicle speed side to increase the shift point vehicle speed to the high gear side, engine braking promptly when deceleration is rapidly performed In order to obtain power, prohibit upshifting to the high gear side or move the upshift line to the high vehicle speed side to increase the shift point vehicle speed to the high gear side Rapid deceleration control, accelerator pedal depression speed or throttle When the opening speed of the valve is equal to or higher than a predetermined value, the shift-up line is moved to the high vehicle speed side to increase the gear change point vehicle speed to the high speed side gear position and prohibit the up shift to the high speed side gear position for a predetermined period. That is the acceleration operation (ΔTA) control.

[0004]

However, in the conventional vehicle provided with the above-mentioned automatic transmission, a control for prohibiting the above-mentioned high speed gear stage or prohibiting the up-shift to it is provided for a predetermined period. Then, while the above-mentioned high-speed gear or the upshift to that gear is prohibited, the vehicle is driven by the gear in which the engine braking does not work because it is achieved by the engagement of the one-way clutch. Power off with pedal returned (coast)
There is a disadvantage that a shock is generated due to engagement of the one-way clutch when shifting from traveling to power-on (acceleration) traveling by depressing the accelerator pedal.

The present invention has been made in view of the above circumstances, and an object of the present invention is to turn off the power when the vehicle travels at another gear by prohibiting the high speed gear. Power-on (acceleration) from running
An object of the present invention is to provide a shift control device that does not generate a shock when shifting to traveling.

[0006]

The gist of the present invention for achieving the above object is to electrically select an engine brake effective state in which engine braking is effective and an engine brake ineffective state in which engine braking is not effective. A shift control device for an automatic transmission for a vehicle, comprising: a first shift stage achieved by engagement of a one-way clutch when the engine brake is ineffective and a second shift stage in which the engine brake is effective. ) Second speed-gear prohibiting means for prohibiting the second speed-gear when the traveling condition of the vehicle satisfies a preset speed-gearing prohibition condition, and (b) the second speed-gear with the second speed-gear prohibiting means. with particular but was banned
And an engine brake state switching means for switching the first shift stage to an engine brake effective state.

[0007]

Effects of the Invention] In this way, with particular the second shift stage is prohibited by the second gear stage inhibit means, first shift stage is switched to the engine braking effective state by the engine brake state switching device Therefore, when the vehicle is traveling at the first gear due to the prohibition of the second gear, the power-off (coasting) traveling in which the accelerator pedal is returned during traveling to the power-on (acceleration) traveling by depressing the accelerator pedal is performed. Even if the shift is made, the one-way clutch is not engaged, so a shock due to the engagement is prevented.

[0008]

According to another aspect of the present invention, preferably, the automatic transmission includes a hydraulic friction engagement device for an engine brake, which is engaged to bring the first shift stage into an effective state of the engine brake. When the second shift speed is prohibited by the second shift speed prohibiting means, a shift is performed from the second shift speed to the first shift speed, or within the first shift speed. When a gear shift is performed, an engagement delay unit that delays the engagement of the engine-brake hydraulic friction engagement device by a predetermined delay time relative to the gear shift to the first gear is further provided. With this configuration, the operation of the hydraulic friction engagement device and the engagement operation of the engine brake hydraulic friction engagement device for achieving the shift from the second shift stage to the first shift stage are performed. Since they do not overlap, shift shock is preferably prevented.

Preferably, the predetermined delay time is
The engagement delay means is preset to a time at which the operation of the hydraulic friction engagement device for achieving the shift from the second shift stage to the first shift stage is surely completed. After the operation of the hydraulic friction engagement device for achieving the shift from the second gear to the first gear is surely completed, the engagement of the engine friction hydraulic friction engagement device is started.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a skeleton view showing an example of an automatic transmission for a vehicle, the shift of which is controlled by a shift control device according to an embodiment of the present invention. In the figure, the output of the engine 10 is input to the automatic transmission 14 via the torque converter 12,
It is adapted to be transmitted to the drive wheels via a differential gear unit and an axle not shown.

The torque converter 12 is the engine 1
Pump impeller 18 connected to the crankshaft 16 of 0 and turbine impeller 2 connected to the input shaft 20 of the automatic transmission 14.
2, a lock-up clutch 24 that directly connects the pump impeller 18 and the turbine impeller 22 and a stator 28 that is prevented from rotating in one direction by a one-way clutch 26.

The automatic transmission 14 includes a first transmission 30 for switching between high and low gears and a second transmission 32 for switching between reverse gear and four forward gears. The first transmission 30 includes an HL planetary gear device 34 including a sun gear S0, a ring gear R0, and a planet gear P0 that is rotatably supported by the carrier K0 and meshed with the sun gear S0 and the ring gear R0. The clutch C0 and the one-way clutch F0 are provided between the sun gear S0 and the housing 41, and the brake B0 is provided between the sun gear S0 and the housing 41.

The second transmission 32 is a first planetary gear unit 36 including a sun gear S1, a ring gear R1, and a planet gear P1 rotatably supported by the carrier K1 and meshed with the sun gear S1 and the ring gear R1.
, Sun gear S2, ring gear R2, and carrier K
2 and a second planetary gear unit 38, which is rotatably supported by the sun gear S2 and a ring gear R2 and is meshed with the sun gear S2 and the ring gear R2, and the sun gear S3, the ring gear R3, and the carrier K3, which are rotatably supported by the sun gear S2. S3 and a third planetary gear set 40 including a planet gear P3 meshed with the ring gear R3.

The sun gear S1 and the sun gear S2 are integrally connected to each other, the ring gear R1, the carrier K2 and the carrier K3 are integrally connected, and the carrier K3 is connected to the output shaft 42. The ring gear R2 is integrally connected to the sun gear S3. A clutch C1 is provided between the ring gear R2 and the sun gear S3 and the intermediate shaft 44, and the sun gear S1 and the sun gear S are provided.
A clutch C2 is provided between the shaft 2 and the intermediate shaft 44. In addition, a band-type brake B1 for stopping the rotation of the sun gear S1 and the sun gear S2 is provided on the housing 41.
It is provided in. A one-way clutch F1 is provided between the sun gear S1 and the sun gear S2 and the housing 41.
And the brake B2 are provided in series. The one-way clutch F1 is configured to be engaged when the sun gear S1 and the sun gear S2 try to rotate in the opposite direction to the input shaft 20.

A brake B3 is provided between the carrier K1 and the housing 41, and a brake B4 and a one-way clutch F2 are provided in parallel between the ring gear R3 and the housing 41. This one-way clutch F
2 is configured to be engaged when the ring gear R3 tries to rotate in the reverse direction.

In the automatic transmission 14 configured as described above, for example, according to the operation table shown in FIG. 2, the reverse first gear and the forward five gears are switched. In FIG. 2, the mark ◯ indicates the engaged state, the mark x indicates the disengaged state, and the mark ⊚ indicates that the lockup clutch 24 is actuated when it is in the engaged or slip state. As is clear from FIG. 2, the drive mechanism is configured so that the engine brake is constantly applied at the high speed side gear stage, that is, the fourth speed gear stage and the fifth speed gear stage. In the first to third gears, the solenoid No. 4 of the fourth solenoid valve S4 is de-energized to cause a hydraulic friction engagement device for engine braking (the brake B4 in the first gear, In the second gear, the clutch C0, the third
In the high speed gear stage, the brake B1) is engaged and the engine brake is applied, and the solenoid of the fourth solenoid valve S4 is actuated.
When No. 4 is excited, the hydraulic friction engagement device for engine brake is released and the one-way clutch (first
One-way clutch F2 in the first gear, one-way clutch F0 in the second gear, and one-way clutch F in the third gear.
The engine brake is in a non-operating state in which the gear stage is achieved by the engagement of 1). Shift lever 7
When 2 is operated to D and 4 range, 1st speed ~
Although the shift range is up to the fifth speed, the fourth electromagnetic valve S4 is de-energized, so that the first to third speeds are in the engine braking state. When the shift lever 72 is operated to the 3 range, the fifth gear is prohibited and the first to third gears are brought into the engine braking state. Shift lever 72
Is operated to the second range, the fifth and fourth gears are prohibited and the first to third gears are prohibited.
The high speed gear is set to the engine braking state. When the shift lever 72 is operated to the L range, the fifth
The first gear and the second gear are prohibited and the first gear is brought into the engine braking state.

As shown in FIG. 3, a throttle valve 56 driven by a throttle actuator 54 based on an operation amount of an accelerator pedal 50 detected by an accelerator operation amount sensor 52 is provided in an intake pipe of an engine 10 of a vehicle.
Is provided. Also, the rotational speed N _E of the engine 10
Engine speed sensor 58 for detecting
Intake air amount sensor 60 for detecting the intake air amount Q / N of
Intake air temperature sensor 6 for detecting the temperature T _A of the intake air
2. A throttle sensor 64 for detecting the opening θ _TH of the throttle valve 56, a vehicle speed sensor 66 for detecting the rotation speed N _OUT of the output shaft 42, that is, a vehicle speed V, and a cooling water temperature sensor for detecting the cooling water temperature T _W of the engine 10. 68, brake switch 70 for detecting the operation of the brake, shift lever 7
The operation position sensor 74 for detecting the operation position P _SH of _No. 2, the clutch C0 rotation sensor 75 for detecting the rotation speed N _C0 of the input shaft 20, that is, the clutch C0, and the oil temperature sensor for detecting the hydraulic oil temperature T _OIL of the hydraulic control circuit 84. 77, etc. are provided, and from those sensors, the engine rotation speed N _E ,
Intake air amount Q / N, intake air temperature T _A , throttle valve opening θ _TH , vehicle speed V, engine cooling water temperature T _W , brake operating state BK, shift lever 72 operating position P _SH , clutch C0 rotation speed A signal representing N _C0 and the hydraulic oil temperature T _OIL is supplied to the engine electronic control unit 76 or the shift electronic control unit 78.

The engine electronic control unit 76 includes a CPU,
A so-called microcomputer having a RAM, a ROM, and an input / output interface, the CPU processes an input signal according to a program stored in the ROM in advance while utilizing a temporary storage function of the RAM, and executes various engine controls. For example, the fuel injection valve 79 is controlled to control the fuel injection amount, the igniter 80 is controlled to control the ignition timing, the bypass valve (not shown) is controlled to control the idle speed, and the throttle actuator is controlled to control the traction. A throttle valve 56 is controlled by 54. The engine electronic control unit 76 is communicably connected to a shift electronic control unit 78, and a signal required for one is appropriately transmitted from the other.

The electronic shift control device 78 is also a microcomputer similar to that described above. The CPU uses the temporary storage function of the RAM while processing the input signal in accordance with the program stored in the ROM 79 in advance, and the hydraulic control circuit 84. Each solenoid valve or linear solenoid valve is driven. For example, the electronic shift control device 78 may include a linear solenoid valve SLT for generating a throttle pressure P _TH having a magnitude corresponding to the opening θ _TH of the throttle valve 56, and a linear solenoid valve SLT for controlling the accumulator back pressure. SLN, lockup clutch 24 engagement, release, slip amount, brake B3
Drive the linear solenoid valve SLU to control the direct control of the clutch and the clutch-to-clutch shift, respectively. Further, the electronic shift control device 78 determines the gear stage of the automatic transmission 14 based on the actual throttle valve opening θ _TH and the vehicle speed V from a pre-stored shift diagram shown in FIG. 5, for example. The solenoid valves S1, S2, S3 are driven so as to obtain the gear position and the engaged state, and the solenoid valve S4 is driven when engine braking is generated.

FIG. 4 is a functional block diagram for explaining a main part of the control function of the electronic control unit, for example, the electronic control unit 78 for shifting. In the figure, the shift control means 100 is
For example, from the pre-stored relationship shown in FIG. 5, the gear shift determination is performed based on the amount indicating the load of the engine 10, for example, the throttle valve opening θ _TH and the actual vehicle speed V, and the gear stage of the automatic transmission 14 is determined. However, the solenoid valves S1, S2, S3 are driven so as to obtain the determined gear and engagement state, and the solenoid valve S4 is used when engine braking is generated.
To drive.

The second shift speed prohibiting means 102 is provided for the shift control means 1 when the preset traveling condition is satisfied.
The high speed gear stage of the automatic transmission 14, for example, the fifth speed gear stage or the fifth speed gear stage and the fourth speed gear stage are prohibited in preference to the shift control by 00. As a result, when the fifth gear position and the fourth gear position are prohibited by the second gear position prohibiting means 102, the engine brake effective state where the engine brake is effective and the engine brake invalid state where the engine brake is not effective are electrically. From the first speed to the third speed (first shift speed), which is achieved by the engagement of the one-way clutch when the engine braking is not effective, the fifth speed gear to which the engine braking is effective. The shift to the fourth gear and the fourth gear (second gear) is prohibited. Here, the prohibition of the second shift speed by the second shift speed prohibiting means 102 is realized by removing the up shift line to the second shift stage and the down shift line from the second shift stage in the shift diagram. However, it is substantially realized by moving the up shift line to the second shift stage and the down shift line from the second shift stage to the high vehicle speed side. The second gear position prohibiting means 102 includes, for example,
In order to obtain driving force or engine braking force when traveling uphill or downhill over a predetermined gradient, prohibit upshifting to the high gear side or move the upshift line to the high vehicle speed side to the high gear side. Shift point for increasing vehicle speed, prohibiting upshifting to the high gear side to obtain engine braking force when the accelerator pedal, that is, the throttle valve is suddenly returned, or prohibiting upshifting to the upshift line To the high gear side to increase the vehicle speed. Accelerator close control to increase the vehicle speed, prohibit upshifting to the high gear side to obtain extra driving force during cornering, or shift up line to the high vehicle speed side. Cornering control to increase the vehicle speed by shifting to
When the driver's driving direction is estimated and acceleration is directed, the upshift to the high gear side is prohibited or the upshift line is moved to the high vehicle speed side to increase the shift point vehicle speed to the high gear side. In order to obtain the engine braking force promptly when rapid deceleration is performed by directivity estimation control and braking operation, upshift to the high gear side is prohibited or the upshift line is moved to the high vehicle speed side Shift point to a higher gear Speed control to increase the vehicle speed, when the accelerator pedal depression speed, that is, the opening speed of the throttle valve is a predetermined value or more, move the shift-up line to a higher vehicle speed side At least a part of the sudden acceleration operation (ΔTA) control for increasing the vehicle speed and prohibiting the upshift to the higher gear for a predetermined period is included.

The engine brake state switching means 104 is
When the fifth gear position and the fourth gear position (second gear position) are prohibited by the second gear position prohibiting means 102,
The solenoid valve S4 is switched from the energized state to the non-excited state to provide a hydraulic friction engagement device for engine braking (brake B4 in the first gear stage, clutch C in the second gear stage).
By engaging the brake B1) at 0 and the third speed, the first to third speeds are switched to the engine brake effective state.

The engagement delay means 106 is prohibited from shifting to the fifth speed gear stage and the fourth speed gear stage (second speed stage) by the second speed stage prohibiting means 102, and the fifth speed gear stage. Alternatively, when down-shifting from the fourth gear to the first gear or the third gear (first gear) is performed,
The engagement of the hydraulic friction engagement device for engine braking is delayed by a predetermined delay time from the downshift to the first speed gear stage or the third speed gear stage (first speed stage). More preferably, the engagement delaying means 106 is configured so that the engine brake hydraulic pressure is reached after the operation of the hydraulic friction engagement device for achieving the shift from the second shift stage to the first shift stage is completed. The engagement of the frictional engagement device is started. The predetermined delay time is preset to a time at which the operation of the hydraulic friction engagement device for achieving the shift from the second shift stage to the first shift stage is completed without fail.

FIG. 6 is a flow chart for explaining the main part of the control operation of the electronic control unit, for example, the electronic control unit 78 for shifting. In step (hereinafter, step will be omitted) SA1 in the figure, it is determined whether or not the shift lever 72 is operated to the D range or the 4 range, which is the maximum forward travel range. If the determination at SA1 is negative, this routine is ended, but if the determination is affirmative, at SA2 it is determined whether or not the actual gear stage of the automatic transmission 14 is the third gear stage. It is judged based on the above. If the determination in SA2 is negative, the routine is ended, but if the determination is affirmative, in SA3 corresponding to the second speed-gear prohibiting means 102, the fourth speed gear and the fifth speed gear are set. Whether it is prohibited or not is determined based on the execution of the uphill / downhill control, the accelerator rapid closing control, the rapid deceleration control, the rapid acceleration operation (ΔTA) control, and the like.

If the determination at SA3 is negative, S
In A4, the non-engine braking mode is selected and the solenoid valve S4 is energized, so that the gears below the third speed in the D range traveling are deactivated. However, if the determination at SA3 is affirmative, at SA5, the engine brake mode is selected, and at SA6 corresponding to the engagement delay means 106, the solenoid valve S4 is de-energized and the engine brake mode is set. The engagement of the hydraulic friction engagement device brings the gear stages below the third speed gear stage in the D range traveling into the engine braking action state.
This SA6 is performed during or after the execution of downshifting from the fourth gear stage or the fifth gear stage to the third gear stage with the prohibition of the fourth gear stage and the fifth gear stage. When the predetermined delay time has not elapsed, the solenoid valve S4 is de-energized after the predetermined delay time has elapsed, and the engagement of the engine brake hydraulic friction engagement device is delayed. Will be started. In the present embodiment, the above SA6
Corresponds to the engagement delay means 106.

According to this embodiment, the second shift speed inhibiting means 1
When the second gear (the fourth gear and the fifth gear) is prohibited by 02, the engine brake state switching means 104 (SA5) causes the first gear (the first gear to the third gear). Gear) is switched to the engine braking effective state, and therefore, when the vehicle is traveling to the first gear due to the prohibition of the second gear, the accelerator pedal is returned during traveling from the power-off (coasting) traveling to the accelerator pedal. Even if the power-on (acceleration) travel is performed by depressing 50, the shock due to the engagement of the one-way clutch is prevented.

Further, according to the present embodiment, when the second shift stage is prohibited by the second shift stage inhibiting means 102, the shift from the second shift stage to the first shift stage (for example, 4
→ 3 downshift) is performed, or when a shift within the first speed stage (for example, 2 → 3 upshift) is performed, the engagement of the hydraulic friction engagement device for engine braking is performed as described above. Since the engagement delay means 106 for delaying the shift to the first shift stage by the predetermined delay time is further provided, the hydraulic friction engagement device for achieving the shift from the second shift stage to the first shift stage. Since the operation of (1) and the engagement operation of the hydraulic frictional engagement device for engine braking do not overlap with each other, the shift shock is preferably prevented. For example, at the time of the 4 → 3 downshift due to the start of prohibiting the upshift to the fourth gear, the brake B1 is engaged so as not to overlap with the clutch C2 for the 4 → 3 downshift. Further, in the case where the 2 → 3 upshift is performed while the fourth speed gear is prohibited, the release of the brake B3 and the engagement of the brake B2 for the 2 → 3 upshift are performed at the same time and then overlapped with that. The brake B1 is engaged so as not to.

FIG. 7 is a flow chart for explaining the control operation in another embodiment of the present invention. In the figure, S
In B1, it is determined whether or not the shift lever 72 is operated to the D range or the 4 range which is the maximum forward travel range. If the determination in SB1 is negative, the routine is ended, but if the determination is affirmative, in SB2 corresponding to the second speed-gear inhibiting means 102, the fourth speed gear and the fifth speed gear are set. Whether it is prohibited or not depends on the uphill / downhill control, accelerator rapid closing control, cornering control, driving direction estimation control, sudden deceleration control, sudden acceleration operation (Δ
TA) Judgment based on execution of control or the like. This SB
When the determination of 2 is denied, this routine is ended, but when the determination of 2 is made, the automatic transmission 1
Whether or not the actual fourth gear is the fourth gear is determined based on the shift output signal or the like.

If the determination at SB3 is affirmative, S
In B4, it is determined whether or not the 4 → 3 downshift determination is performed. If this determination at SB4 is negative, this routine is ended, but if the determination is affirmative, a predetermined delay time T1 that has been set in advance from the shift determination at SB5 corresponding to the engagement delay means 106 has elapsed. It is determined whether or not. When the predetermined delay time T1 elapses, S
Since the determination at B5 is affirmative, at SB9 corresponding to the engine braking state switching means 104, the engine brake hydraulic friction engagement device is engaged, and the third gear is brought to the engine braking state. .

If the determination at SB3 is negative, S
At B6, it is determined whether the actual gear stage of the automatic transmission 14 is the second gear stage based on the gear shift output signal or the like. If the determination at SB6 is negative, the routine is terminated, but if the determination is affirmative, it is determined at SB7 whether or not the 2 → 3 upshift determination is performed. If the determination in SB7 is negative, the routine is terminated, but if the determination is affirmative, the predetermined delay time T2 set in advance from the shift determination in SB8 corresponding to the engagement delay means 106 has elapsed. It is determined whether or not. When the predetermined delay time T2 elapses, the determination at SB8 is affirmative, so at SB9, the engine brake hydraulic friction engagement device is engaged and the third gear is brought into the engine brake state.

According to this embodiment, similarly to the embodiment of FIG. 6 described above, the second shift speed prohibiting means 102 prohibits the second shift speed (the fourth speed gear and the fifth speed gear). As a result, when the vehicle travels to the first shift stage, the engine braking is performed even if the power-off (coasting) traveling in which the accelerator pedal is returned during traveling is switched to the power-on (acceleration) traveling by depressing the accelerator pedal 50. Since the mode is set, the shock due to the engagement of the one-way clutch is prevented, and the engagement delay means 106 (SB5,
Due to SB8, the engagement operation of the hydraulic friction engagement device for engine brake is delayed more than the operation of the hydraulic friction engagement device for achieving the shift from the second shift stage to the first shift stage. Since they do not overlap with each other, shift shock is preferably prevented. The delay times T1 and T2 are 4 →
Since different values are set in the case of 3 downshift and in the case of 2 → 3 upshift, shift shock is reliably prevented.

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, during downhill traveling, that is, during traveling in which the throttle valve opening θ _TH is zero and the brake is operated, the second gear position prohibiting means 102 causes the fourth gear position and the fifth gear position. Is prohibited, eg 5 → 4
When the downshift or the 4 → 3 downshift is executed, the throttle valve 56 is temporarily opened during the downshift period to increase the engine speed N _E to 5
By engaging the clutch C0 for achieving the → 4 downshift or engaging the brake B1 for achieving the 4 → 3 downshift, as in the case of the so-called constant speed shift,
Shift shock may be reduced.

Further, in the above-described embodiment, the flex lockup control is performed in which the lockup clutch 24 is slip-engaged so as to have a predetermined target slip rotation speed in order to expand the fuel cut region during deceleration traveling. Good. In this case, for example, when the highest gear is prohibited and the 5 → 4 downshift is performed by starting the downhill control in association with the brake operation, for example, similar to the manual 5 → 4 downshift, The gear shift shock may be reduced by temporarily increasing the target slip rotation speed.

Further, although the automatic transmission 14 of the above-described embodiment has five forward gears, it may have four forward gears or six forward gears, and an electric motor may be used instead of the engine 10. .

Further, in the above-described embodiment, the engine braking state switching means 104 sets the first to third speed gear stages to the engine braking state, but only the third speed gear stage is set to the engine braking state. It may be.

In the embodiment shown in FIG. 7, the SB
In 5 and SB8, it was determined whether or not the elapsed time from the shift determination of the 4 → 3 downshift or the 2 → 3 upshift exceeded the preset delay time T1 or T2. Alternatively, the elapsed time from the completion of the shift of the 2 → 3 up shift, that is, the time when the gear ratio of the third gear is obtained may be used. By doing so, there is an advantage that the influence of the variation in the shift period is eliminated and the engine braking state can be quickly obtained.

Although not individually exemplified, the present invention can be carried out in various modified and improved modes based on the knowledge of those skilled in the art.

[Brief description of drawings]

FIG. 1 is a skeleton diagram illustrating a configuration of an automatic transmission for a vehicle that is shift-controlled by a shift control device according to an embodiment of the present invention.

FIG. 2 is a chart showing a relationship between a combination of operations of a plurality of solenoid valves or hydraulic friction engagement devices in the automatic transmission of FIG. 1 and gear stages established by the combination.

FIG. 3 is a diagram illustrating an electrical configuration of a control device included in the vehicle of FIG.

FIG. 4 is a functional block diagram illustrating a main part of a control function of the electronic shift control device of FIG.

5 is a diagram showing a shift diagram used in the shift control means of FIG. 3. FIG.

FIG. 6 is a flowchart illustrating a main part of a control operation of the electronic shift control device of FIG.

FIG. 7 is a flowchart illustrating a main part of a control operation of the electronic shift control device according to another embodiment of the present invention, and is a diagram corresponding to FIG. 6;

[Explanation of symbols]

14: Automatic transmission 78: Electronic control unit for shifting 100: shift control means 102: Second gear speed prohibiting means 104: Engine brake state switching means 106: engagement delay means

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI F16H 63:12 F16H 63:12 (56) References JP-A-2-163565 (JP, A) JP-A-3-272363 (JP , A) JP 61-36543 (JP, A) JP 6-117529 (JP, A) JP 6-346961 (JP, A) Actual development 2-333963 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) F16H 59/00-61/12 F16H 61/16-61/24 F16H 63/40-63/48

Claims (2)

(57) [Claims] 1. An engine braking effective state in which engine braking is effective and an engine braking ineffective state in which engine braking is ineffective are electrically selected, and are achieved by engagement of a one-way clutch in a state in which the engine braking is ineffective. 1st gear and 2nd with engine braking
A shift control device for an automatic transmission for a vehicle having a shift speed, the shift control means for prohibiting the second shift speed when a running condition of the vehicle satisfies a preset shift prohibition condition; , with particular the second shift stage is prohibited by the second shift stage prohibiting means, and an engine brake state switching means for switching the first speed stage to the engine braking effective state,
A shift control device for an automatic transmission for a vehicle, comprising: 2. The automatic transmission includes an engine brake hydraulic friction engagement device that is engaged to bring the first shift stage into an engine brake effective state, and the second shift stage. When the prohibiting means prohibits the second shift stage and shifts from the second shift stage to the first shift stage, the engagement of the engine friction hydraulic friction engagement device is changed to the first shift stage. 2. The shift control device for a vehicular automatic transmission according to claim 1, further comprising engagement delay means for delaying the shift to one shift stage by a predetermined delay time.