US 4,226,295 AGranted

Gear shift system and method with optional gas pedal controlled shaft initiation

AssigneeRobert Bosch GmbH

InventorsHelmut Rembold, Ernst Linder, Ferdinand Grob

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Abstract

Rapid movement of the gas pedal initiates a shifting operation to the next higher or next lower gear depending upon whether the speed of the gearing lies above or below a predetermined speed range. The speed range extends from a first to a second predetermined speed. Both the width of the range and the actual values of the first and second predetermined speed are automatically adjusted as a function of the throttle valve position and the then-present gear. If the gas pedal is not activated but the gear speed is less than a predetermined first threshold speed, an automatic down-shift takes place. Up-shifting can only occur when the speed of the gearing exceeds a minimum up-shift speed. Engagement and disengagement of the clutch is controlled and may include jolt limiting. The engine speed is limited during gear shifting.

Claims52

Dependent claims

In an automotive vehicle having a gas pedal (34), an engine having a throttle valve (35) coupled to said gas pedal, gearing (43), gear speed sensor means (45) for furnishing a transmission speed signal indicative of the speed of said gearing, and gear shift means (42) for changing gear ratios in said gearing in response to shift command signals, a system for furnishing said shift command signals to said gear shift means, comprising, means (36-39) connected to said gas pedal for furnishing a desired gear shift signal only when the magnitude of rate of change of position of said gas pedal exceeds a predetermined magnitude;

shift enable signal furnishing means (46, 80) connected to said gear speed sensor means, for furnishing an up-shift enable signal when the speed of said gearing exceeds a predetermined first gear speed and for furnishing a down-shift enable signal when the speed of said gearing is less than a predetermined second gear speed;
and gear control means (41) connected to said desired gear shift signal furnishing means and said shift enable signal furnishing means, for furnishing an up-shift command signal to said gear shift means in response to the simultaneous presence of said desired gear shift signal and said up-shift enable signal, and for furnishing a down-shift command signal to said gear shift means in response to the simultaneous presence of said desired gear shift signal and said down-shift enable signal.

In a motor vehicle having a gas pedal (34), a throttle valve (35) coupled to said pedal, gearing having a plurality of gear ratios, and gear shift means (42) for changing said gear ratios in response to gear shift command signals applied thereto, a method for furnishing said gear shift command signals to said gear shift means, comprising the steps of

sensing the rotary speed of said gearing and furnishing a first transmission speed signal only when the rotary speed of said gearing exceeds a predetermined first gear speed and a second transmission speed signal only when the rotary speed of said gearing is less than a predetermined second gear speed;
substantially simultaneously sensing the rate of change of position of said throttle valve relative to a closed position and furnishing a first limiting derivative signal only when the rate of change of position of said throttle valve exceeds a first predetermined throttle valve position change value and furnishing a second limiting derivative signal only when the rate of change of said throttle valve position exceeds a second predetermined throttle valve position change value;
and furnishing an upshift command signal to said gear shift means only in response to the simultaneous presence of said first limiting derivative signal and said first transmission speed signal and furnishing a downshift command signal only in response to the joint presence of said second limiting derivative signal and said second transmission speed signal.

Dependencies are inferred from the claim text.