Automatic engine stop control system for vehicles

• US 6,334,834 B1
• Filed: 03/23/2000
• Issued: 01/01/2002
• Est. Priority Date: 03/25/1999
• Status: Expired due to Fees

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Mizutani, Koichi, Kusaka, Yasushi
• Primary Examiner(s): Wright, Dirk
• Application Number:
  US09/533,926
• Time in Patent Office: 649 Days
• Field of Search: 477/187, 477/203, 477/205
• US Class Current: 477/203
• CPC Class Codes: B60T 13/585 comprising friction brakes and retarders
• CPC Class Codes: B60T 17/02 Arrangements of pumps or compressors, or control devices therefor
• CPC Class Codes: F02D 17/04 rendering engines inoperative or idling, e.g. caused by abnormal conditions dependent on lubricating conditions F01M1/22; dependent on cooling F01P5/14
• CPC Class Codes: F02D 29/02 peculiar to engines driving vehicles; peculiar to engines driving variable pitch propellers
• CPC Class Codes: F02D 41/123 the fuel injection being cut-off
• CPC Class Codes: F02N 11/003 said electric motor being also used as a drive for auxiliaries, e.g. for driving transmission pumps or fuel pumps during engine stop
• CPC Class Codes: F02N 11/084 State of vehicle accessories, e.g. air condition or power steering
• CPC Class Codes: F02N 2200/0807 Brake booster state
• CPC Class Codes: F02N 2200/0808 Steering state, e.g. state of power assisted steering
• CPC Class Codes: F02N 2200/124 Information about road conditions, e.g. road inclination or surface
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

An automatic engine stop control system for a vehicle in which: an engine is activated when fed with a fuel; and an action mechanism has an action content influenced by a rotating state of the engine; and the fuel feed to the engine is stopped when predetermined conditions are satisfied during the running of the vehicle comprises: a rotating state decider for deciding that the engine is forced to rotate by a running inertia force owned by the vehicle while the vehicle is coasting; an action state decider for deciding the action content of the action mechanism in the state where the engine is forced to rotate by the running inertia force of the vehicle; and an automatic stop inhibitor for inhibiting the stop of the fuel feed to the engine when it is decided by the action state decider means that the action content of the action mechanism is insufficient.

Claims

1. An automatic engine stop control system for a vehicle, which has:

an engine to be activated when fed with a fuel; and

a brake booster for assisting a braking force which has an action content influenced by a rotating state of the engine, and in which the fuel feed to the engine is stopped when predetermined conditions are satisfied during a running of the vehicle, comprising;

rotating state deciding means for deciding that the engine is forced to rotate by a running inertia force owned by the vehicle while the vehicle is coasting;

action state deciding means for deciding that the action content of the brake booster is insufficient when a pressure difference between a vacuum in the brake booster and an atmospheric pressure drops to a lower level than a predetermined value, in a state where the engine is forced to rotate by the running inertia force of the vehicle; and

automatic stop inhibition means for inhibiting the stop of the fuel feed to the engine when it is decided by the action state deciding means that the pressure difference between the vacuum in the brake booster and the atmospheric pressure drops to a lower level than the predetermined value.

2. An automatic vehicle engine stop control system according to claim 1,

wherein the action mechanism includes a brake booster for assisting a braking force, and

wherein the action state deciding means includes means for deciding that the action content is insufficient when the braking force generated by the brake booster is lower than a predetermined value.

3. An automatic vehicle engine stop control system according to claim 2,

wherein the action state deciding means further includes means for deciding that the action content is insufficient when a pressure difference between a vacuum in the brake booster and an atmospheric pressure drops to a lower level than a predetermined value.

4. An automatic vehicle engine stop control system according to claim 1, further comprising:

an automatic stop control selecting mechanism for executing an automatic stop control to stop the fuel feed to the engine when it is manually operated and when predetermined conditions are satisfied during the running of the vehicle.

5. An automatic vehicle engine stop control system according to claim 1,

wherein the predetermined conditions contain the fact that the state where a throttle opening is less than a predetermined degree continues for a predetermined time period.

6. An automatic vehicle engine stop control system according to claim 1, further comprising:

means for stopping an ignition of the engine after a predetermined time period was elapsed from the instant when the fuel feed to the engine had been stopped.

7. An automatic engine stop control system for a vehicle, which has:

an engine to be activated when fed with a fuel; and

an action mechanism having an action content influenced by a rotating state of the engine, and in which the fuel feed to the engine is stopped when predetermined conditions are satisfied during a running of the vehicle, comprising;

rotating state deciding means for deciding that the engine is forced to rotate by a running inertia force owned by the vehicle while the vehicle is coasting;

action state deciding means for deciding that the action content of the action mechanism in a state where the engine is forced to rotate by the running inertia force of the vehicle;

automatic stop inhibition means for inhibiting the stop of the fuel feed to the engine when it is decided by the action state deciding means that the action content of the action mechanism is insufficient; and

means for stopping an ignition of the engine after a predetermined time period has elapsed from an instant when the fuel feed to the engine has been stopped.