Apparatus and method for detecting a position of an actuator piston
First Claim
1. In an injection molding system, an apparatus for continuous monitoring of axial position of an actuator piston traveling between upstream and downstream positions within an axial bore of an actuator housing, the apparatus comprising:
- a magnetic member embedded in the actuator piston;
the actuator housing having a body portion which is of a substantially non-magnetic and/or magnetically permeable material, such that during axial travel of the actuator piston within an axial bore of the non-magnetic or magnetically permeable body portion, the body portion allows transmission of a magnetic field generated by the magnetic member embedded in the actuator piston to be detected by a magnetic field detector attached to an exterior surface of the body portion,the magnetic field detector monitoring changes in a magnetic flux density generated by the magnetic member disposed in the piston as the piston travels between upstream and downstream positions within the axial bore, the detector monitoring the changes in flux density and generating a changing output signal that is unique to each travel position in the bore based on the changes in flux density,wherein the magnetic member has a north-south axis disposed transverse to the direction of axial travel in the bore such that the magnetic flux density varies depending on where the detector is attached relative to the axial travel position of the piston and the embedded magnetic member in the piston, andwherein the output signal of the magnetic field detector is transmitted to a control system for closed loop control or open loop status monitoring of the axial piston position.
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Accused Products
Abstract
Apparatus and method for detecting a position of an actuator piston driving a valve pin in an injection molding system. The apparatus includes an actuator housing having a body portion, surrounding an axial bore, of a substantially non-magnetic and/or magnetically permeable material, a piston, movable within the axial bore for driving a valve pin, the piston including a magnetic member generating a magnetic field such that axial movement of the piston in the bore modifies the magnetic field according to the position of the piston relative to a detection position, and a magnetic field detector attached to an exterior surface of the body portion at the detection position for detecting the magnetic field associated with the position of the piston and generating an output signal determined by the piston position.
34 Citations
14 Claims
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1. In an injection molding system, an apparatus for continuous monitoring of axial position of an actuator piston traveling between upstream and downstream positions within an axial bore of an actuator housing, the apparatus comprising:
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a magnetic member embedded in the actuator piston; the actuator housing having a body portion which is of a substantially non-magnetic and/or magnetically permeable material, such that during axial travel of the actuator piston within an axial bore of the non-magnetic or magnetically permeable body portion, the body portion allows transmission of a magnetic field generated by the magnetic member embedded in the actuator piston to be detected by a magnetic field detector attached to an exterior surface of the body portion, the magnetic field detector monitoring changes in a magnetic flux density generated by the magnetic member disposed in the piston as the piston travels between upstream and downstream positions within the axial bore, the detector monitoring the changes in flux density and generating a changing output signal that is unique to each travel position in the bore based on the changes in flux density, wherein the magnetic member has a north-south axis disposed transverse to the direction of axial travel in the bore such that the magnetic flux density varies depending on where the detector is attached relative to the axial travel position of the piston and the embedded magnetic member in the piston, and wherein the output signal of the magnetic field detector is transmitted to a control system for closed loop control or open loop status monitoring of the axial piston position. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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Specification