Deceleration control device of an internal combustion engine

• US 4,799,466 A
• Filed: 07/09/1987
• Issued: 01/24/1989
• Est. Priority Date: 11/29/1984
• Status: Expired due to Term

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Shibata, Yoshiaki, Ohnaka, Hidemi
• Primary Examiner(s): Wolfe, Willis R.
• Assistant Examiner(s): Carlberg, Eric R.
• Application Number:
  US07/073,316
• Time in Patent Office: 565 Days
• Field of Search: 123/332, 123/333, 123/493, 123/559, 123/327, 123/589
• US Class Current: 123/327
• CPC Class Codes: F02D 41/0005 during deceleration
• CPC Class Codes: F02D 41/123 the fuel injection being cut-off
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A deceleration control device of an engine comprising an intake passage which has a throttle valve therein. A bypass passage is branched from intake passage upstream of the throttle valve and is connected to the intake passage downstream of the throttle valve. A flow control valve is arranged in the bypass passage. At the time of deceleration, when the supply of fuel is cut, the flow control valve opens to increase the flow area of the bypass passage by a predetermined flow area.

Claims

1. A deceleration control device of an internal combustion engine having an intake passage which has a throttle valve therein, said engine including a automatic transmission with at least a neutral and a drive position, said device comprising:

a bypass passage branched from a location in the intake passing upstream of the throttle valve to a location in the intake passage downstream of the throttle valve;

valve means arranged in said bypass passage for controlling a flow area of said bypass passage;

means for supplying fuel, arranged in said intake passage;

detecting means for detecting a deceleration state of the engine and producing an output signal representing said deceleration state;

fuel supply control means for controlling said fuel supply means in response to the output signal of said detecting means to produce a fuel cut signal to cut the supply of fuel from said fuel supply means when said deceleration state is a predetermined deceleration state; and

valve control means for controlling said valve means in response to said fuel cut signal to increase the flow area of said bypass passage when the supply of fuel from said bypass means is cut, wherein said valve means opens to increase the flow area of said bypass passage by a predetermined flow area when said fuel cut signal is produced, and said valve means closes to reduce the flow area of said bypass passage when the production of said fuel cut signal is stopped, said predetermined flow area being further changed in accordance with a shift range of said automatic transmission and being larger in said neutral position than in said drive position.

2. A device according to claim 1, wherein said detecting means comprises engine speed sensor means for detecting the engine speed, and a throttle switch means for detecting that the throttle valve is in an idling position, said fuel cut signal being produced when the throttle valve is in the idling position and when the engine speed is higher than a predetermined cut speed, the production of said fuel cut signal being stopped when the throttle valve is in the idling position and when the engine speed decreases below a predetermined return speed.

3. A device according to claim 2, further comprising a digital computer having a ROM, said return speed being stored in said ROM, said cut speed being calculated by adding a fixed speed to said return speed.

4. A device according to claim 1, wherein the flow area of aid bypass passage is maintained constant during the time said fuel cut signal is produced.

5. A device according to claim 1, wherein said engine comprises an automatic transmission, said valve means closes at said first speed to an opening degree which is determined by a shift range of said automatic transmission.

6. A device according to claim 5, wherein the shift range of said automatic transmission comprises an N position and a D range, said opening degree in said N position being larger than said opening degree in said D range.

7. A device according to claim 1, further comprising a throttle switch which produces an output signal indicating that the throttle valve is in an idling position, an engine speed sensor which produces an output signal representing the engine speed, and idling speed control means which controls said valve means in response to the output signals of said throttle switch and said engine speed sensor to maintain the engine speed at a predetermined idling speed when the throttle valve is in the idling position.

8. A device according to claim 7, wherein said idling speed control means stops the control of said valve means when said fuel cut signal is produced.

9. A device according to claim 8, wherein said idling speed control means starts the control of said valve means when the production of said fuel cut signal is stopped.

10. A device according to claim 1, further comprising a mechanical supercharger driven by the engine and arranged in the intake passage downstream of the throttle valve.

11. A device according to claim 1, wherein said valve means comprises a valve port formed in said bypass passage, a valve body which cooperates with said valve port, and a stepper motor connected to said valve body for driving said valve body.

12. A device as in claim 1 wherein said valve control means includes means for initially closing said valve means at a first speed and subsequently closing said valve means at a second speed which is lower than said first speed.