JP3193187B2 - Linear motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear motor, and more particularly to a linear motor for conveying an optical card or the like of an information recording / reproducing apparatus.

[0002]

2. Description of the Related Art As shown in FIG. 10, an information recording / reproducing apparatus using an information card 1 such as an optical card or the like has a card carrier 2 with the information card 1 held on the card carrier 2. Linearly reciprocates the optical head 3 and reciprocates the optical head 3 in a direction orthogonal to the direction of the linear reciprocation of the card carrier 2 to scan a data track on the information card to record and reproduce information. (For example, see
No. 4-1183).

In this type of apparatus, the card carrier 2 is reciprocated linearly by a linear motor 4. Although not shown, the optical head 3 performs a linear reciprocating motion by a similar linear motor.

As shown in FIG. 11, the linear motor 4 has a linear magnet 6 disposed at the center of a first yoke 5 and supports 7 at both ends in the longitudinal direction of the first yoke 5.
In addition, a second yoke 9 is mounted so as to form a linear gap 8 with the linear magnet 6, and a current is applied to the movable coil 10 wound around the second yoke 9 through the linear gap 8. The moving coil 10 is moved in the longitudinal direction of the linear magnet 6 by the electromagnetic action of the flowing current and the magnetic field in the linear gap 8.

As shown in FIGS. 8 and 9, the yoke of the conventional linear motor 4 has a screw hole 11 formed at an upper portion of the support portion 7 and a through hole formed at a position of the second yoke 9 corresponding to the screw hole 11. 12 and the second yoke 9 is first
It was designed to be attached to the yoke 5.

[0006]

In the information recording / reproducing apparatus, in order to speed up the recording on or reproduction from the information card 1 and to reduce the size of the entire apparatus, the linear motor 4 is used. It is necessary to use a linear magnet 6 having a high magnetic flux density. For this reason, a strong force having a complicated directional distribution that repels and attracts works on the second yoke 9 and the like depending on the direction and strength of the magnetic flux by the linear magnet 6.

Conventionally, the screw hole 11 and the through hole 12
And the second yoke 9 is moved to the first position with the screw 13.
When the linear magnet is attached to the yoke 5, the linear magnet receives a strong force acting on the second yoke 9 and the like, so that it is not easy to accurately align the screw hole 11 and the through hole 12. As a result, there is a problem that the assembly cost of the linear motor 4 is increased.

Further, a screw 1 is used to facilitate the mounting.
For example, it is necessary to use a screw made of a non-magnetic material as 3, and there is a problem that the component cost of the linear motor 4 is increased.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art and to provide a linear motor in which the second yoke can be easily attached to the first yoke even under a strong force applied to the second yoke and the like. It is to provide.

[0010]

In order to achieve the above object, a linear motor according to the present invention comprises a first yoke provided with linear magnets and a support provided at both longitudinal ends of the first yoke. A second yoke is mounted so as to form a linear gap between the linear magnet and the linear magnet, and a current is passed through a movable coil wound around the second yoke through the linear gap, And a linear motor that moves the movable coil in the longitudinal direction of the linear magnet by an electromagnetic action of a magnetic field in the linear gap and at least two first retaining portions having a convex shape on an upper portion of the support portion. At least two recessed second fastening portions are formed at the end of the second yoke, and the first fastening portion and the second fastening portion are fitted to each other to attach the second yoke to the first yoke. Dress Wherein the first fastening portion is a spring pin erected on the upper portion of the support portion, and one of the second fastening portions is cut in the longitudinal direction from the longitudinal end face of the second yoke. The other side of the second fastening portion is a lateral hole formed by being cut in the side direction from an end surface of the second yoke in the side direction, and the second yoke is formed in the second yoke. Is fitted to one of the spring pins in a state in which the first yoke is slightly overlapped with the first yoke, and then the second yoke is rotated around the spring pin so that the second yoke is largely overlapped with the first yoke. In this state, the lateral hole and the other spring pin are fitted, and the second yoke is mounted on the first yoke.

[0011]

According to the present invention, the concave or convex first retaining portion formed at the upper portion of the support portion and the convex or concave second retaining portion formed at the end of the second yoke are fitted to each other. Since the second yoke is mounted on the first yoke, it is not necessary to use a screw. Therefore, it is necessary to position the screw hole under a strong force applied to the second yoke or the like and screw the screw. And the second yoke can be easily attached to the first yoke.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a linear motor according to the present invention will be described below with reference to FIGS.

A first embodiment of the present invention will be described with reference to FIGS. 1, 3 and 4. FIG. 1 is an exploded view of a linear motor yoke used to drive the card carrier 2. In FIG. 1, the first yoke 25 is formed in a rectangular plate shape, and a rectangular plate-shaped linear magnet 26 is mounted at the center of the first yoke 25. Linear magnet 26
Has an N pole on the upper surface and an S pole on the lower surface. Near the longitudinal end of the linear magnet 26, rectangular block-shaped support portions 27 are attached. Spring pins 33, 3 are provided on the upper portions of the respective support portions 27, 27.
3 are erected. The height of the support portion 27 is such that a predetermined linear gap 28 is formed between the lower surface of the second yoke 29 and the upper surface of the linear magnet 26. Second yoke 2
9 is formed in a rectangular plate shape, and a through hole 32 is formed in the vicinity of the end in the longitudinal direction at a position corresponding to the position of the spring pins 33.

As shown in FIG. 4, a magnetic field 35 is formed in the linear gap 28 in a direction perpendicular to the upper surface of the linear magnet 26. The movable coil 3 extends in a direction orthogonal to the direction of the magnetic field 35.
Due to the electromagnetic interaction between the current 37 flowing through the zero and the magnetic field 35, the card carrier 2 receives a propulsive force in a direction perpendicular to the paper surface. The moving direction of the card carrier 2 is controlled by changing the direction of the current 37.

The second yoke 9 and the like are attracted by the linear magnet 6 with a strong force. In addition, a leakage magnetic field 36 is generated near the end of the linear magnet 26. A strong directional distribution between the end of the second yoke 29 in the longitudinal direction and the support portion 27 having a complicated direction distribution that repels or attracts depending on the direction and strength of the leakage of the magnetic field 35 and the leakage magnetic field 36. Power is working.

Next, the operation of this embodiment will be described. First, the movable coil 30 is inserted through the second yoke 29, and thereafter,
The through holes 32, 32 are aligned with the spring pins 33, 33. Next, the second yoke 29 is connected to the support portions 27, 27.
To the through holes 32, 32 and the spring pins 33,
33 is fitted. At a position separated from the upper surface of the linear magnet 26 by the length of the spring pins 33, 33, the through hole 3 is formed.
Since the fitting of the spring pins 33, 33 with the spring pins 2, 32 can be started, the work can be performed in a state where the force received by the second yoke 29 is reduced. It should be noted that only one set of the through-hole 32 and the spring pin 33 are first aligned and lightly fitted, and then the second yoke 29 is rotated around the previously aligned spring pin 33 to rotate the other set. It is also possible to align and fit the through hole 32 and the spring pin 33.

According to the structure of the present embodiment, the support portion 27 is provided with the spring pins 33, 33 and the second yoke 2
9 is provided with a through hole 32, so that the second
The yoke 29 can be easily attached to the support 27. As a result, under the strong magnetic force exerted on the second yoke 29 and the like by the linear magnet 26, there is no need to align the screw holes and screw them together as in the related art.
9 can be easily attached to the first yoke 25.

Further, since it is not necessary to use a screw, it is not necessary to form the screw with a non-magnetic material.

Next, a first embodiment of the present invention will be described with reference to FIG. In FIG. 2, a second yoke 29 has a second
A longitudinal hole 38 cut in the longitudinal direction from the longitudinal end face of the yoke 29 and a lateral hand hole 39 cut in the lateral direction from the lateral end face of the second yoke 29 are formed. .

The mounting of the second yoke 29 is performed as follows. As shown in FIG. 2B, after the longitudinal hole 38 is fitted to one of the spring pins 33,
The second yoke 29 is rotated about the axis to fit the lateral hole 39 and another spring pin 33.

According to the structure of this embodiment, since the elongated hole 38 and the lateral hole 39 are formed in the second yoke 29, the positioning with the spring pins 33, 33 can be easily performed.

Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 5 is an exploded view of the yoke of the linear motor driving the optical head 3, FIG. 6 is a plan view showing the optical head 3 driven by the linear motor, and FIG. FIG.

In FIG. 5, the first yoke 2 is a rectangular plate.
5 is bent at both ends and integrally connected to the support portion 27. Cut portions 40, 40 cut into a rectangular shape are formed on the upper portion of the support portion 27. Second yoke 29
Are formed with rectangular projections 41, 41 that fit into the cutouts 40, 40 at the ends in the longitudinal direction. The depths of the cuts 40 are equal to the thickness of the second yoke 29, and the lengths of the protrusions 41 are equal to the thickness of the support 27. The length of the second yoke 29 in the longitudinal direction is such that the inner end surface of the one support portion 27 and the other support portion 27
Is formed so as to be equal to the distance between the inner end surface and the inner end surface.

Next, the operation of this embodiment will be described. First, after the movable coil 30 is inserted through the second yoke 29, the notches 40, 40 and the projections 41, 41 are aligned, and the second yoke 29 is pressed against the support parts 27, 27, and the notches 40, 40 are formed. And the projections 41, 41 are fitted.
At this time, the side end surface in the longitudinal direction of the second yoke 29 abuts on the inner surface of the support portion 27.

According to the structure of this embodiment, the notch 4
Since the projections 41 and 41 and the projections 41 are provided, the second yoke 29 can be attached to the support 27 without using screws.

The notches 40, 40 and the projection 4
At the same time that the first yoke 29 is fitted to the first yoke 29, the longitudinal end surface of the second yoke 29 is brought into contact with the inner surface of the support portion 27, so that the second yoke 29 is stably attached to the support portion 27. be able to.

[0027]

As is apparent from the above description, according to the present invention, a concave or convex first retaining portion formed on the upper portion of the support portion and a convex or concave shape formed on the end of the second yoke are provided. The second yoke is fitted to the second yoke so that the second yoke is mounted on the first yoke, so that it is not necessary to use a screw. There is no need to screw up and align
The second yoke can be easily attached to the first yoke.

[Brief description of the drawings]

FIG. 1 is a schematic exploded view of a yoke of a linear motor for driving a card carrier according to a first embodiment of the present invention.

FIG. 2 is a schematic exploded view of a linear motor according to a second embodiment of the present invention. (A) shows the positional relationship between the second yoke and the support, and (b) shows the procedure for fitting the second yoke to the support.

FIG. 3 is a plan view showing a card carrier driven by a linear motor.

FIG. 4 is a longitudinal sectional view as viewed from AA in FIG. 3;

FIG. 5 is a schematic exploded view of a yoke of a linear motor for driving an optical head according to a third embodiment of the present invention.

FIG. 6 is a plan view showing an optical head driven by a linear motor.

FIG. 7 is a vertical cross-sectional view taken along line BB in FIG. 6;

FIG. 8 is a schematic exploded view showing a conventional linear motor for driving a card carrier.

FIG. 9 is a schematic exploded view showing a conventional linear motor for driving an optical head.

FIG. 10 is a perspective view showing a schematic configuration of an information recording / reproducing apparatus.

FIG. 11 is a perspective view showing a schematic configuration of a conventional linear motor.

[Explanation of symbols]

 Reference Signs List 25 first yoke 26 linear magnet 27 support portion 28 linear gap 29 second yoke 32 through hole 33 spring pin 38 long hole 39 lateral hole 40 cutout portion 41 protrusion

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-183254 (JP, A) JP-A-4-21182 (JP, U) JP-A 63-83983 (JP, U) JP-A 62-183 115777 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) H02K 33/18 H02K 41/02

Claims (1)

(57) [Claims] A linear magnet is disposed on a first yoke, and support portions at both ends in a longitudinal direction of the first yoke are provided on a first yoke.
A second yoke is mounted so as to form a linear gap between the linear magnet and the linear magnet, and a current is applied to a movable coil wound around the second yoke through the linear gap,
In a linear motor that moves the movable coil in a longitudinal direction of the linear magnet by an electromagnetic action of the current and a magnetic field in the linear gap, at least two first retaining portions having a convex shape are formed above the support portion. And at least two concave second retaining portions are formed at the end of the second yoke, and the first retaining portion and the second retaining portion are fitted to each other to move the second yoke to the first yoke. The first fastening portion is a spring pin erected on an upper portion of the support portion, and one of the second fastening portions extends from a longitudinal end surface of the second yoke in the longitudinal direction. The other side of the second fastening portion is a lateral hole formed by being cut in a side direction from an end face in a side direction of the second yoke; The second yoke is After fitting the longitudinal hole into one of the spring pins in a state in which the first yoke is slightly overlapped with one yoke, the second yoke is rotated around the spring pin to make a state in which the second yoke is largely overlapped with the first yoke. It fitted a transverse hole and the other of the spring pin, a linear motor, characterized in that you mount the second yoke to the first yoke.