JPS60136649A - Control method of automatic speed changer for vehicle - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a control and method for automatic transmissions used in vehicles such as automobiles, and more particularly to a hydraulic torque converter and a gear transmission as an auxiliary transmission. The present invention relates to a method of controlling an automatic transmission having the following.

BACKGROUND OF THE INVENTION Automatic transmissions used in vehicles such as automobiles generally include a hydraulic torque converter and a gear transmission as an auxiliary transmission, and the gear transmission has a plurality of gears and a neutral gear. The gears can be switched between the plurality of gears depending on the vehicle speed and the amount of depression of the accelerator pedal.

Conventionally, in the automatic transmission for a vehicle as described above, when the manual shift range is set to a driving range such as the D range, the gear transmission always changes to the current state, including when the accelerator pedal is released. The gear stage is achieved according to the vehicle speed and the amount of depression of the accelerator pedal, and the internal combustion engine and the wheels are drivingly connected. The fact that the internal combustion engine and the wheels are connected even when the accelerator pedal is released is useful for obtaining an engine braking effect, but this engine braking effect depends on the transmission ratio (input shaft/output shaft). The larger the difference, the more the effect is obtained, and it does not occur so conspicuously at the highest speed gear where the gear ratio is small, especially at the overdrive gear.

It is known that one measure to reduce the running fuel consumption of a vehicle is to operate the internal combustion engine at as low a speed as possible. When not being driven, that is, when coasting with the accelerator pedal released, internal combustion
It is preferable to separate the engine from the wheels and operate the internal combustion engine at idle speed.

OBJECTS OF THE INVENTION The present invention provides a method for achieving a gear when a gear in which a significant engine braking effect can be achieved is to be achieved (also when the accelerator pedal for obtaining the engine braking effect is released). In order to improve driving fuel efficiency, when a gear position that does not provide a significant engine braking effect is to be achieved, a neutral gear position that separates the internal combustion engine from the wheels can be achieved by releasing the accelerator pedal to improve driving fuel efficiency. The purpose of this invention is to provide a control method for an automatic transmission for a vehicle that can improve driving fuel efficiency without impairing the above engine braking effect.

Structure of the Invention The above-mentioned object of the present invention is to provide a hydraulic torque converter, a plurality of gears and a neutral gear, and to change the plurality of gears according to the vehicle speed and the amount of depression of the accelerator pedal. In a method for controlling a vehicular automatic transmission having a gear transmission that is switched between gears, the accelerator pedal is not pressed even when the highest gear among the plurality of gears is to be achieved. This is achieved by a method of controlling a vehicle automatic transmission characterized in that the gear is switched to the neutral gear when the pedal is released.

Effects of the Invention According to the method of controlling an automatic transmission for a vehicle according to the present invention, the accelerator pedal is released even when the highest gear such as an overdrive gear is to be achieved among a plurality of gears. When the engine is running, a neutral stage is achieved, the internal combustion engine and the wheels are disconnected, and the internal combustion engine is operated at an idle speed, thereby improving the fuel efficiency of the vehicle. Neutral gear is achieved when the accelerator pedal is released from the highest gear Φ, where no noticeable engine braking effect can be obtained. When the middle gear is to be achieved, that gear is achieved even if the accelerator pedal is released, so an engine braking effect is obtained, and therefore, as described above, when the highest gear is to be achieved. Even if the neutral gear is achieved without achieving the highest speed gear when the accelerator pedal is released, the practical engine braking effect is not impaired.

DESCRIPTION OF EMBODIMENTS The present invention will now be described in detail with reference to embodiments with reference to the accompanying drawings.

The attached drawing schematically shows the configuration of an apparatus for carrying out the method for controlling an automatic transmission for a vehicle according to the present invention. The automatic transmission 1 is well known in itself, and includes an input shaft 2 drivingly connected to the output shaft of an engine 10O, a hydraulic torque converter 3, and a hydraulic torque converter 3.
] A direct coupling clutch 4 that directly connects the input shaft 2 to the output shaft 3a of the hydraulic torque converter 3, and an auxiliary transmission device.

The gear transmission 7 has a shaft 5 connected to the output shaft 3a of the hydraulic torque converter 3 as an input shaft, and an output shaft drivingly connected to the input shaft and the drive wheels of the vehicle. 6 and a plurality of gear ratios selected from a plurality of gear ratios, and a neutral gear that disconnects the input shaft and the output shaft from the drive coupling relationship. It looks like this. This includes a gear transmission mechanism 7.

The gear transmission 7 includes a carrier 8 connected to the input shaft 5 and a planetary pinion 9 supported by the carrier.
, a sun gear 10 and a ring gear 11 meshed with the planetary binion, a one-way clutch (Fo) 12 connected between the carrier 8 and the sun gear 10, and an OD that selectively couples the carrier 8 and the sun gear 1O. A clutch (Co) 13 and an OD brake (Bo) that selectively fixes the sun gear 1O to the transmission case.
) 14, which is used as an overdrive device in this gear transmission 7.

The gear transmission 7 includes a sun gear 15, two ring gears 16 and 17, and a planetary pinion 18 that is located between the sun gear 15 and the ring gear 16 and meshes with them.
It has another planetary binion that is located between the sun gear 15 and the ring gear 17 and meshes with them, and carriers 20 and 21 that rotatably support planetary binions 18 and 19, respectively. The ring gear 16 is supported by an intermediate shaft 22, and the intermediate shaft 22 is selectively connected to the ring gear 11 in a torque transmission relationship by a forward clutch (C+) 23. The sun gear 15 is supported by an intermediate shaft 24, and the intermediate shaft 24 is selectively connected to the ring gear 11 in a torque transmission relationship by a direct clutch (C2>25).The intermediate shaft 24 is locked when the engine is driven. The one-sided clutch (F+>26 and the second brake (Blr27) are selectively fixed to the transmission woofer and selectively prevented from rotating by a direct connection 1Hfi with the one-sided clutch (F+>26 and the second brake (Blr27), which is in the state, and is also connected in parallel to the series connection mechanism. A band-type second coast brake (B+) 28 selectively fixes the series connection mechanism to the transmission case and selectively prevents its rotation.Carrier 2
1 is a one-sided clutch (F2>29 that locks when the engine is driving), which is fixed to the transmission case and prevented from rotating only when the engine is driving, and a fast & reverse brake (Ba) 3'
O is selectively fixed to the transmission case and its rotation is selectively prevented. Both the ring gear 17 and the carrier 20 are connected to the output shaft 6.

Each of the clutches 13.23.25 and brakes 14.27.28.3O of the gear transmission 7 is driven by a hydraulic servo device (not shown), and the operation of each hydraulic servo device is performed by the hydraulic control device 31. It has become.

The hydraulic control II device 31 includes four electromagnetic valves 32 to 35,
It has a manual shift valve (not shown) that is switched by a manual shift lever 41 that is operated by hand, and various hydraulic control valves and speed change valves (not shown). The gear transmission 7 is controlled to switch between a plurality of gears and a neutral stage by controlling the supply and discharge of hydraulic pressure to the hydraulic servo of the gear transmission 7 by opening and closing each gear, and is directly connected by opening and closing the solenoid valve 35. clutch 4
The switch is controlled to switch between an engaged state and a released state. The basic structure of this hydraulic control device 31 has already been proposed in Japanese Patent Application No. 55-6911 'O by the applicant and the same applicant, and if a more detailed explanation of this hydraulic control device is required, Patent application 1986-6911'
Please refer to the specification and drawings of No. O.

The solenoid valve 34 is a newly provided solenoid valve for carrying out the control method according to the present invention. In addition to supplying and discharging the oil pressure, for example, when an on signal is given, the hydraulic pressure of the hydraulic servo device of the oD brake 14 is discharged.

The opening and closing of the electromagnetic valves 32 to 35 are performed by electric signals individually applied to each electromagnetic valve by an electronic control unit 36. The electronic control device 36 has an arithmetic processing function such as a microcomputer, and receives information regarding the vehicle speed from the vehicle speed sensor 37 and information regarding the throttle opening of the internal combustion engine 100 from the throttle opening sensor 38, in other words, the amount of depression of the accelerator pedal. The brake switches 39 each give information regarding whether or not the brakes for braking the vehicle are in operation, and the solenoid valves 32 to 35 are activated according to the information.
An on-off electrical signal is individually output to each of them.

By individually applying an on signal or an off signal to the two solenoid valves 32 and 33, the two solenoid valves open and close individually, thereby opening and closing the clutch 13.2 of the gear transmission 7.
3.25 and brake 14.17.28.3O are operated in combinations as shown in the table below, and the gears are changed between multiple gears of four forward gears including an overdrive gear and one reverse gear. The stage is switched and set.

In this list, the O mark indicates that the relevant clutch or brake is engaged, the × mark indicates that the relevant clutch or brake is released, and the Δ mark indicates that the relevant one-way clutch is on the engine side. This indicates that it is engaged (locked) when the engine is driving the vehicle, and released (free) during engine braking when the engine is driven from the vehicle side. Note that in the L range, an upshift to the second gear is not performed, and only a downshift from the second gear to the first gear is performed. In this list, θ indicates the throttle opening of the internal combustion engine.

The electromagnetic control i device 36 turns on the electromagnetic valve 34 when the throttle opening e detected by the throttle angle sensor 38 is zero, that is, when the accelerator pedal is released and the throttle valve of the internal combustion engine 10O is in the fully open position. It is designed to output a signal.

When an ON signal is given to the solenoid valve 34, the solenoid valve opens, the hydraulic pressure of the hydraulic servo device of the OD brake 14 is discharged, and the OD brake is released.

The 0D brake 14 is engaged only in the overdrive stage, so if the accelerator pedal is released when the overdrive stage is to be achieved,
In addition to the OD clutch 13, the 0D brake 14 is released, and the overdrive planetary gear device consisting of the carrier 8, planetary binon 9, sun gear 10, and ring gear 11 is in a state where no rotational power is transmitted, and the input A neutral stage is achieved in which the shaft 5 and the output shaft 6 are separated from each other in their driving connection.

As mentioned above, even when the overdrive gear, which is the highest gear, should be achieved, when the throttle opening is zero and the accelerator pedal is released, the neutral gear is achieved and the internal combustion engine 1 'O'O was separated from the wheel of a vehicle not shown in the diagram.

At this time, the internal combustion engine 1'O'0 comes to be operated at the idle speed, thereby improving driving fuel efficiency.

As mentioned above, the conditions for achieving the neutral gear while driving are when the highest gear is to be achieved, when the accelerator pedal is released, and when the vehicle speed is below a predetermined value and the vehicle It is advantageous that the braking brake is not activated in order to prevent a large shock from occurring when returning to a predetermined gear due to the neutral gear and to quickly brake the vehicle. Further, it is more preferable that the ON signal output from the electronic control device 36 to the solenoid valve 34 is canceled by a manual switch 40 operated by the driver's will. If the manual switch 4° is provided, the driver's will selectively prohibits the vehicle from entering the neutral gear when the highest gear should be achieved and the accelerator pedal is released. Even at the highest gear, a slight engine braking effect can be obtained.

Although the present invention has been described in detail with respect to specific embodiments above, the present invention is not limited thereto.
It will be apparent to those skilled in the art that various embodiments are possible within the scope of the invention.

[Brief explanation of drawings]

The attached figure is a schematic configuration diagram schematically showing the configuration of a device for implementing the control method for an automatic transmission for 11 vehicles according to the present invention. DESCRIPTION OF SYMBOLS 1... Automatic transmission, 2... Input shaft, 3... Fluid torque converter, 4... Direct coupling clutch, 5...
Shaft, 6... Output shaft, 7... Gear transmission, 8...
Carrier, 9...Planetary binion, 10...Sun gear, 11...Ring gear, 12...One-way clutch, 13...OD clutch, 14...OD brake, 15...Sun gear, 16.17...Ring gear, 18.19...Planetary binion, 20.2
DESCRIPTION OF SYMBOLS 1... Carrier, 22... Intermediate shaft, 23... Forward clutch, 24... Intermediate shaft, 25... Direct clutch, 26... One-way clutch, 27...
Second brake, 28...Second coast brake, 29...One-way clutch. 30...Fast & reverse brake, 31...
Hydraulic control device, 32-35... Solenoid valve, 36... Electronic control @ position, 37... Vehicle speed sensor, 38... Throttle opening sensor, 39... Brake switch, 4O.
...Manual switch, 41...Manual shift lever - Patent applicant Toyota Motor Corporation Representative Patent attorney Masaki Akashi

Claims (1)

[Claims] An automatic transmission for a vehicle comprising a fluid torque converter and a gear transmission having a plurality of gears and a neutral gear and being switched between the plurality of gears depending on the vehicle speed and the amount of depression of an accelerator pedal. The method for controlling an aircraft is characterized in that even when the highest speed among the plurality of gears is to be achieved, when the accelerator pedal is released, the gear is switched to the neutral gear. A method for controlling an automatic transmission for a vehicle.