D.C. Electromagnetic actuator
AssigneeHitachi Metals, Ltd.
InventorsNorio Matsumoto, Teruo Umehara
Life of this patent
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Abstract
An actuator driven by D.C. power suitable for use in actuating automobile door locking device. The actuator has a yoke apparatus defining a space, two annular solenoid coils supported and received by the yoke apparatus and adapted to be energized simultaneously such that poles of the same polarity appear at the adjacent ends of the coils, and moving means reciprocatably disposed in the space of the yoke apparatus. The moving means includes an axially magnetized permanent magnet carried by a shaft and a pair of magnetic members attached to both axial ends of the permanent magnet.
Claims17
A direct current actuator for use in a vehicle door locking device, adapted to be operated by means of an electric switch, said actuator comprising:
- a yoke apparatus having a hollow cylindrical yoke member, an annular center yoke member projecting inwardly from the middle inner peripheral surface of said cylindrical yoke member, a pair of end yoke means disposed in opposite end portions of said cylindrical yoke member to axially separate from said center yoke member to form a magnetic gap therebetween;
- two annular solenoid coil means supported by said yoke apparatus therein and disposed axially separately in such a manner that the poles of the same polarity are generated in the adjacent end portions of said solenoid coils when they are energized;
- and
- a moving means disposed in a space defined by said yoke apparatus and having a predetermined annular gap between the periphery of said moving means and said yoke apparatus so as to reciprocate in said space, said moving means having an axially magnetized permanent magnet, a pair of magnetic members attached to the axially opposite ends of said permanent magnet, and a shaft engaging with said permanent magnet, each of said magnetic members including an annular portion attached to said permanent magnet and a tapered portion tapered toward the adjacent end of said actuator, and said end yoke means being so shaped as to be able to receive said tapered portion of said magnetic member.
A direct current actuator for use in a vehicle door locking device, adapted to be operated by means of an electric switch, said actuator comprising:
- a yoke apparatus having a hollow cylindrical yoke member, an annular center yoke member projecting inwardly from the middle inner peripheral surface of said cylindrical yoke member, a pair of end yoke means disposed in opposite end portions of said cylindrical yoke member to axially separate from said center yoke member to form a magnetic gap therebetween;
- two annular solenoid coil means supported by said yoke apparatus therein and disposed axially separately in such a manner that the poles of the same polarity are generated in the adjacent end portions of said solenoid coils when they are energized;
- and
- a moving means disposed in a space defined by said yoke apparatus and having a predetermined annular gap between the periphery of said moving means and said yoke apparatus so as to reciprocate in said space, said moving means having an axially magnetized permanent magnet, a pair of magnetic members attached to the axially opposite ends of said permanent magnet, and a shaft engaging with said permanent magnet, wherein the following conditions (i), (ii) and (iii) are met:
- A>C and D>C (i)
- B.gtoreq.C.gtoreq.lg (ii)
- 0.ltoreq.(L/2)-(B-C)/2.ltoreq.5[mm] (iii)
- where,
- A represents the axial distance between the end surfaces of said end yokes adjacent to said center yoke, B represents the axial length of the portion of said center yoke opposing to said moving means, C represents the axial length between the inner end surfaces of said magnetic members at the outer peripheral surface of said moving means, D represents the axial length between the end surfaces of said magnetic members adjacent to the ends of said actuator at the outer peripheral surface of said moving means, lg represents the length of radial gap between the inner surface of said yoke apparatus and the outer peripheral surface of said moving means, and L represents the length of the entire stroke of said moving means.
Dependencies are inferred from the claim text.