Apparatus for controlling engine brake force during vehicle running on downhill with released accelerator
First Claim
1. An apparatus for controlling an engine brake force of a motor vehicle having an engine, an accelerator pedal, and an automatic transmission which is shifted to change the speed ratio according predetermined shifting conditions, said engine brake force being produced by said engine when said accelerator pedal is in a released state, said apparatus comprising:
- an accelerator position sensor for detecting an operating amount of said accelerator pedal;
a vehicle speed sensor for detecting an actual running speed of the vehicle;
desired-speed determining means for determining whether said operating amount of the accelerator pedal detected by said accelerator position sensor is reduced below a predetermined threshold which is close to zero, and determining a desired speed of the vehicle on the basis of said actual running speed detected by said vehicle speed sensor when said operating amount is reduced below said predetermined threshold;
intake air control means for controlling an intake air quantity of said engine such that said actual running speed approaches said desired speed; and
limiting means for limiting said intake air quantity controlled by said intake air control means, to a value not exceeding a reference value which is determined on the basis of said speed ratio of the automatic transmission and said actual running speed of the vehicle, so as to permit said actual running speed to be maintained at said desired speed when the vehicle runs on a level road surface.
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Accused Products
Abstract
An apparatus for controlling the engine brake of a motor vehicle, adapted to control the intake air quantity of the engine so as to maintain the actual vehicle speed at a desired speed. The apparatus includes a device for avoiding acceleration of the vehicle during running on a downhill with the accelerator pedal released, and a device to permit deceleration of the vehicle during the subsequent running on an uphill road. The apparatus may include a device for increasing the engine brake force when the brake pedal is depressed, by fully closing the throttle valve and/or shifting down the transmission, to assure sufficient engine braking effect upon depression of the brake pedal on a downhill. The apparatus may include a device for updating the desired vehicle speed when the actual speed is lowered by depression of the brake pedal, to prevent acceleration of the vehicle after the brake pedal is released at the end of a downhill. The desired vehicle speed may be updated when the difference between the initially determined desired speed and the actual speed exceeds a given limit, or when the brake pedal is released.
48 Citations
31 Claims
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1. An apparatus for controlling an engine brake force of a motor vehicle having an engine, an accelerator pedal, and an automatic transmission which is shifted to change the speed ratio according predetermined shifting conditions, said engine brake force being produced by said engine when said accelerator pedal is in a released state, said apparatus comprising:
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an accelerator position sensor for detecting an operating amount of said accelerator pedal; a vehicle speed sensor for detecting an actual running speed of the vehicle; desired-speed determining means for determining whether said operating amount of the accelerator pedal detected by said accelerator position sensor is reduced below a predetermined threshold which is close to zero, and determining a desired speed of the vehicle on the basis of said actual running speed detected by said vehicle speed sensor when said operating amount is reduced below said predetermined threshold; intake air control means for controlling an intake air quantity of said engine such that said actual running speed approaches said desired speed; and limiting means for limiting said intake air quantity controlled by said intake air control means, to a value not exceeding a reference value which is determined on the basis of said speed ratio of the automatic transmission and said actual running speed of the vehicle, so as to permit said actual running speed to be maintained at said desired speed when the vehicle runs on a level road surface. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An apparatus for controlling an engine brake force of a motor vehicle having an engine, an accelerator pedal, a brake pedal, and an automatic transmission which is shifted to change the speed ratio according to predetermined shifting conditions, said engine brake force being produced by said engine when said accelerator pedal is in a released state, said apparatus comprising:
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an accelerator position sensor for detecting an operating amount of said accelerator pedal; a vehicle speed sensor for detecting an actual running speed of the vehicle; determining means for determining whether said accelerator pedal is in said released state in which said operating amount is smaller than a predetermined threshold close to zero; first control means operated in response to a determination by said determining means that said accelerator pedal is in said released state, for increasing the engine brake force with an increase in said actual running speed of the vehicle detected by said vehicle speed sensor; brake detecting means for detecting that said brake pedal of the vehicle is depressed;
ansecond control means operated in place of said first control means when said brake pedal is depressed, for controlling said engine brake force such that the engine brake force controlled by the second control means is larger than that controlled by said first control means. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17)
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18. An apparatus for controlling an engine brake force of a motor vehicle having an engine, an accelerator pedal, and an automatic transmission, said engine brake force being produced by said engine when said accelerator pedal is in a released state, said apparatus comprising:
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an accelerator position sensor for detecting an operating amount of said accelerator pedal; a vehicle speed sensor for detecting an actual running speed of the vehicle; desired-speed determining means for determining whether said operating amount of the accelerator pedal detected by said accelerator position sensor is reduced below a predetermined threshold which is close to zero, and determining a desired speed of the vehicle on the basis of said actual running speed detected by said vehicle-speed sensor when said operating amount is reduced below said predetermined threshold; engine brake control means for controlling said engine brake force so as to prevent said actual running speed of the vehicle detected by said vehicle speed sensor from exceeding said desired speed determined by said desired-speed determining means; and updating means for updating said desired speed of the vehicle on the basis of said actual running speed, when said actual running speed becomes smaller than said desired speed by more than a predetermined value. - View Dependent Claims (19, 20, 21, 22, 23)
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24. An apparatus for controlling an engine brake force of a motor vehicle having an engine, an accelerator pedal, a brake pedal, and an automatic transmission, said engine brake force being produced by said engine when said accelerator pedal is in a released state, said apparatus comprising:
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an accelerator position sensor for detecting an operating amount of said accelerator pedal; a vehicle speed sensor for detecting an actual running speed of the vehicle; desired-speed determining means for determining whether said operating amount of the accelerator pedal detected by said accelerator position sensor is reduced below a predetermined threshold which is close to zero, and determining a desired speed of the vehicle on the basis of said actual running speed detected by said vehicle-speed sensor when said operating amount is reduced below said predetermined threshold; engine brake control means for controlling said engine brake force so as to prevent said actual running speed of the vehicle detected by said vehicle speed sensor from exceeding said desired speed determined by said desired-speed determining means; brake detecting means for detecting whether said brake pedal is depressed; and updating means operated when said brake pedal is depressed, for updating said desired speed of the vehicle on the basis of at least said actual running speed detected by said vehicle speed sensor when said brake pedal is released. - View Dependent Claims (25, 26, 27, 28, 29, 30, 31)
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Specification