Position detecting apparatus for actuator and variable valve lift mechanism for internal combustion engine
First Claim
1. A position detecting apparatus for an actuator, comprising:
- a rotor in which plural magnets are provided on a predetermined pitch circle whose center is a center of a drive shaft, the plural magnets being provided at intervals of a predetermined angle;
a coil which is provided so as to face the magnet such that a magnetic field is formed between the coil and the magnet;
a shaft which is connected to the rotor through a movement conversion mechanism that converts rotational movement to linear movement, and which is linearly moved in response to rotational movement of the rotor, the rotational movement being caused by energizing the coil; and
a sensor portion which detects a change in magnetic flux of the magnet, the change being caused by the rotational movement of the rotor, and which obtains an amount of linear movement of the shaft based on the detected change in the magnetic flux,wherein the magnets are buried in the rotor so as to be exposed on an end portion of the rotor, the end portion facing the sensor portion.
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Accused Products
Abstract
A position detecting apparatus for an actuator includes a linear movement mechanism in which a magnet is provided; a coil which is provided so as to face the magnet such that a magnetic field is formed between the coil and the magnet; and a drive shaft which is connected to the linear movement mechanism through a ball screw, and which is linearly moved in response to rotational movement of the rotor, the rotational movement being caused by energizing the coil; and a magnetic flux detection sensor which detects a change in magnetic flux of the magnet, the change being caused by the rotational movement of the rotor, and which obtains an amount of linear movement of the drive shaft based on the detected change in the magnetic flux.
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Citations
8 Claims
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1. A position detecting apparatus for an actuator, comprising:
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a rotor in which plural magnets are provided on a predetermined pitch circle whose center is a center of a drive shaft, the plural magnets being provided at intervals of a predetermined angle; a coil which is provided so as to face the magnet such that a magnetic field is formed between the coil and the magnet; a shaft which is connected to the rotor through a movement conversion mechanism that converts rotational movement to linear movement, and which is linearly moved in response to rotational movement of the rotor, the rotational movement being caused by energizing the coil; and a sensor portion which detects a change in magnetic flux of the magnet, the change being caused by the rotational movement of the rotor, and which obtains an amount of linear movement of the shaft based on the detected change in the magnetic flux, wherein the magnets are buried in the rotor so as to be exposed on an end portion of the rotor, the end portion facing the sensor portion. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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Specification