Method and apparatus for controlling stepping motor in idling rotational speed control
First Claim
1. Idling rotation speed control apparatus for an electronically controlled engine, comprising:
- an engine air intake path portion;
a throttle valve in said intake path portion;
a bypass path parallel to said intake path portion;
a valve for controlling the sectional area of flow in said bypass path, said valve comprising a valve body and a stepping motor displacing said valve body according to step values;
an ignition switch;
an electronic control controllably supplied with electric power in response to the opening and closing of said ignition switch, said electronic control being connected to said sepping motor and comprising a central processing unit and first memory storage means for storing step values of said stepping motor;
second memory storage means for storing a step value of said stepping motor, said second memory storage means being supplied with electric power irrespective of the opening and closing of said ignition switch, and capable of continuous memory storage;
said central processing unit operating said stepping motor according to the step value stored in said first memory storage means to control the sectional area of flow in response to the idling rotation speed of the engine, storing the step value of said stepping motor in said second memory storage means, and making the step value stored in said first memory storage means equal to the step value stored in said second memory storage means following an interruption of electric power supplied to said electronic control; and
said electronic control determining whether said second memory storage means step value is correct, and making said first memory storage means step value equal to said second memory storage means step value only when said second memory storage means step value is correct.
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Accused Products
Abstract
A bypass path is provided parallel to an intake path portion provided with a throttle valve, and the sectional area of flow in the bypass path is controlled by a valve body displaced by a stepping motor. The step value of the stepping motor is stored in a first memory storage of an electronic control. A second memory storage can keep values irrespective of opening and closing an ignition switch and the step value is stored also in the second memory storage. Corrected step values are supplied to the first memory storage from the second memory storage, from read only memory, or from a value dependent on temperature in a manner which will not result in stalling of the engine due to momentary interruptions in the supply of electric power to the electronic control.
19 Citations
18 Claims
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1. Idling rotation speed control apparatus for an electronically controlled engine, comprising:
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an engine air intake path portion; a throttle valve in said intake path portion; a bypass path parallel to said intake path portion; a valve for controlling the sectional area of flow in said bypass path, said valve comprising a valve body and a stepping motor displacing said valve body according to step values; an ignition switch; an electronic control controllably supplied with electric power in response to the opening and closing of said ignition switch, said electronic control being connected to said sepping motor and comprising a central processing unit and first memory storage means for storing step values of said stepping motor; second memory storage means for storing a step value of said stepping motor, said second memory storage means being supplied with electric power irrespective of the opening and closing of said ignition switch, and capable of continuous memory storage; said central processing unit operating said stepping motor according to the step value stored in said first memory storage means to control the sectional area of flow in response to the idling rotation speed of the engine, storing the step value of said stepping motor in said second memory storage means, and making the step value stored in said first memory storage means equal to the step value stored in said second memory storage means following an interruption of electric power supplied to said electronic control; and said electronic control determining whether said second memory storage means step value is correct, and making said first memory storage means step value equal to said second memory storage means step value only when said second memory storage means step value is correct. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method for idling rotation speed control for an electronically controlled engine having an intake path portion, a throttle valve in the intake path portion, a bypass path parallel to the intake path portion, and a valve operated by a stepping motor for controlling the sectional area of flow in the bypass path, said method comprising the steps of:
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operating the stepping motor according to a step value stored in a first memory storage means controllably supplied with electric power in response to the opening and closing of an ignition switch to control the sectional area of flow in response to the idling rotation speed of the engine; storing the step value of the stepping motor in the first memory storage means; storing the step value of the stepping motor in a second memory storage means supplied with electric power irrespective of the opening and closing of said ignition switch and capable of continuous memory storage; determining whether the step value stored in the second memory storage means is correct; and making the step value stored in the first memory storage means equal to the step value stored in the second memory storage means following an interruption in electric power supplied to said electronic control only when the second memory storage means step value is correct. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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Specification