Electronically controlled automatic transmission

• US 4,941,096 A
• Filed: 12/09/1987
• Issued: 07/10/1990
• Est. Priority Date: 12/10/1986
• Status: Expired due to Term

• Current Assignee: Aisin-Warner K.K.
• Original Assignee: Aisin-Warner K.K.
• Inventors: Suzuki, Kenji, Ito, Yasunobu
• Primary Examiner(s): Gruber, Felix D.
• Application Number:
  US07/130,776
• Time in Patent Office: 944 Days
• Field of Search: 364/424.1, 74/866, 74/843, 74/862, 74/855, 73/118.1
• US Class Current: 701/55
• CPC Class Codes: F16H 2059/0221 for selecting modes, i.e. input device for selecting between different modes with range selector F16H2059/082; for conjoint control B60W30/182
• CPC Class Codes: F16H 2059/087 Winter mode, e.g. to start on snow or slippery surfaces
• CPC Class Codes: F16H 2061/023 Drive-off gear selection, i.e. optimising gear ratio for drive off of a vehicle
• CPC Class Codes: F16H 2312/02 Driving off
• CPC Class Codes: F16H 59/08 Range selector apparatus
• CPC Class Codes: F16H 59/66 Road conditions, e.g. slope, slippery
• CPC Class Codes: F16H 61/0213 characterised by the method for generating shift signals

Abstract

If a driver wishes to start off an automotive vehicle in second or third gear when the vehicle is at rest on a road surface having a low coefficient of friction, as is the case when a road surface is covered with snow, the driver operates a winter mode selection switch while the transmission is in the speed range in which the vehicle ordinarily travels, i.e. the D range. After the vehicle has started off in the higher gear following use of the switch, the transmission switches over to the ordinary travel mode automatically as vehicle velocity rises. In a case where the engine is turned off and then restarted, the transmission switches over to the ordinary travel mode automatically. This eliminates any inconvenience that might be caused by forgetting to operate the switch prior to the restarting of the engine.

Claims

1. An electrically controlled automatic transmission for an automotive vehicle having shift solenoids for controlling gear selection of said transmission, comprising:

an electronic control unit for detecting ordinary start-up and high gear start-up of said vehicle, for driving said solenoids to engage a low gear for initial movement of said vehicle when ordinary start-up is detected, and for driving said solenoids to engage a higher gear than said low gear for initial movement of said vehicle when said high gear start-up is detected;

start-up setting means for manually switching between said ordinary start-up and said high gear start-up;

said electronic control unit including decision means for determining whether the instant state of vehicle velocity is within an acceptable region for said low gear, when said start-up setting means has been switched to said high gear start-up;

high gear start-up output means for driving said shift solenoids to engage said higher gear, when said instant state of vehicle velocity is within said acceptable region for said low gear; and

high gear start-up dismissal means for switching to said ordinary start-up, when said instant state of vehicle velocity is outside of said acceptable region for said low gear.

2. The automatic transmission according to claim 1, wherein said start-up setting means includes display means for displaying high gear start-up is in effect.

3. An electrically controlled automatic transmission for an automotive vehicle having shift solenoids for controlling gear selection of said transmission, comprising:

an electronic control unit for driving said shift solenoids in an ordinary shifting mode by responding to signals from a throttle opening sensor and vehicle velocity sensor including engaging a low gear for initial movement of said vehicle;

switch means for manually engaging one of said ordinary shifting mode and a high gear start-up;

said electronic control unit having decision means for determining whether an instant state of vehicle velocity is within an acceptable region for said low gear, when said high gear start-up has been engaged;

high gear start-up output means driving said solenoids to engage a higher gear than said low gear for initial movement of said vehicle, when said high gear start-up has been engaged and said instant state of vehicle velocity is within said acceptable region for said low gear; and

high gear start-up dismissal means for switching from said high gear start-up to said ordinary shifting mode, when said high gear start-up has been engaged and said instant state of vehicle velocity is outside of said acceptable region for said low gear.

4. The automatic transmission according to claim 3, wherein said electronic unit includes means for driving a display means for displaying high gear start-up when engaged.