US 6,106,433 A · Control system of automotive automatic transmission

Abstract

A motor vehicle includes an internal combustion engine and an automatic transmission powered by the engine. The engine has a throttle valve for controlling the amount of air fed thereto. The transmission selectively assumes an Over-drive possible D-range wherein both a lock-up ON condition and a lock-up OFF condition are available and an Over-drive impossible D-range wherein only the lock-up OFF condition is kept. A control system comprises a first section for detecting a first condition of the engine wherein an open degree of the throttle valve is reduced to a certain degree; a second section for detecting a second condition of the transmission wherein the lock-up ON condition of the Over-drive possible D-range is kept; and a third section for engaging a friction element of the transmission to induce an engine brake when the first and second sections detect the first and second conditions respectively.

Claims8

Dependent claims

A control system comprising:

a first section for effecting a fuel cut to an engine when a throttle opening of the engine is smaller than a given degree and an engine speed is higher than a given degree;
and
a second section for controlling an automatic transmission powered by said engine, said transmission having therein a lock-up device and an overrun clutch, said lock-up device including a lock-up clutch, said transmission inducing engine brake by engaging said overrun clutch,
wherein said second section provides the transmission with both:
a first forward driving range wherein the engine brake is induced when the throttle opening is reduced to a certain degree irrespective of condition of said lock-up clutch;
and
a second forward driving range wherein the induction of the engine brake by the reduction of the throttle opening is carried out only when the transmission assumes a lock-up ON condition effected by said lock-up clutch.

4 more elements

In a motor vehicle including an internal combustion engine and an automatic transmission powered by the engine, said engine having a throttle valve for controlling the amount of air fed thereto, said transmission selectively assuming an Over-drive possible D-range wherein both a lock-up ON condition and a lock-up OFF condition are available and an Over-drive impossible D-range wherein only the lock-up OFF condition is kept,

a control system comprising:
a first section for detecting a first condition of the engine wherein an open degree of said throttle valve is reduced to a certain degree;
a second section for detecting a second condition of the transmission wherein the lock-up ON condition of the Over-drive possible D-range is kept;
a third section for detecting the lock-up OFF condition of the Over-drive impossible range;
a fourth section for engaging an overrun clutch of the transmission to induce an engine brake when said first and second sections detect the first and second conditions respectively;
and
a fifth section for engaging said overrun clutch of the transmission to induce the engine brake when said first and third sections detect the first and third conditions respectively.

4 more elements

Dependencies are inferred from the claim text.

Control system of automotive automatic transmission

Life of this patent

Control system of automotive automatic transmission

Life of this patent

Abstract

Claims8