US 5,698,778 A · Throttle valve opening sensor

Abstract

A sensor has a rotor mounted on a throttle shaft, permanent magnets mounted on an end of the rotor and rotatable together with the rotor and the throttle shaft, a Hall-effect element fixed on a rotational axis of the magnets for outputting an electric signal corresponding to the direction of the magnetic field, and a circuit member for compensating the temperature characteristics of the magnets and the Hall-effect element and for driving the Hall-effect element and processing the output from the Hall-effect element. A circuit chamber of the sensor is filled with silicon gel to add heat capacity to the circuit member. A resin member having notches around a periphery thereof is disposed in a connecting portion of the rotor at which the rotor is connected to the throttle shaft to block heat conduction from the shaft toward the magnets. Thus, the temperature conditions of the circuit member, the magnets and the Hall-effect elements are substantially equalized to achieve high precision in detection of the throttle valve opening regardless of external temperature changes.

Claims13

Dependent claims

A throttle valve opening sensor comprising:

a throttle shaft;
a rotor mounted on the throttle shaft and supporting a throttle valve on an axis of the throttle valve so that the rotor turns responsive to turning of the throttle shaft;
a magnet mounted on the rotor and rotatable together with the rotor, the magnet being magnetized generally perpendicularly to a rotational axis of the rotor;
a magnetoelectric element, fixed to a housing, positionable in a hollow space defined by the magnet, the magnetoelectric element outputting an electric signal corresponding to direction of a magnetic field of the magnet;
a circuit member, in a circuit chamber formed in the housing, for compensating temperature characteristics of the magnet and temperature characteristics of the magnetoelectric element and for processing an electric signal from the magnetoelectric element in a required manner;
and
temperature transition compensating means, including a heat retaining member at least partially filling the circuit chamber, for making time-dependent temperature transition characteristics of the magnet and the circuit member approximately equal to one another.

4 more elements

Dependencies are inferred from the claim text.

Throttle valve opening sensor

Life of this patent

Throttle valve opening sensor

Life of this patent

Abstract

Claims13