JPH06351214A - Linear motor - Google Patents

Abstract

PURPOSE:To easily attach a second yoke to a first yoke even under a strong force by a method wherein a first fixation part which is formed at the upper part of a support part and whose shape is recessed or protruding and a second fixation part which is formed at the end part of the second yoke and whose shape is pfotruding or recessed are fitted to each other, mounted and bonded. CONSTITUTION:A first yoke 25 is formed to be a rectangular plate shape, a rectangular plate-shaped linear magnet 26 is mounted on, and bonded to, the central part, rectangular block-shaped support parts 27, 27 are attached near end parts in the length direction of the linear magnet 26, and spring pins 33, 33 are erected and installed at the upper part of the individual support parts 27, 27. In addition, a second yoke 29 is formed to be a rectangular plate shape, and through holes 32 are made in positions corresponding to positions of the springs 33, 33 near end parts in the length direction. As a result, since the second yoke 29 can be attached easily to the support parts 27 without using a screw, the second yoke 29 can be attached easily to the first yoke 25 under a strong magnetic force acting on the second yoke 29 or the like by the linear magnet 26.

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 carrying an optical card 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 has a card carrier 2 with the information card 1 held on the card carrier 2. Linearly reciprocating, and the optical head 3 linearly reciprocating in a direction orthogonal to the linear reciprocating direction of the card carrier 2 to scan a data track on the information card to record and reproduce information. (For example, JP-A-6
4-1183).

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

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

As shown in FIGS. 8 and 9, the yoke of the conventional linear motor 4 has a screw hole 11 formed in the upper portion of the support portion 7, and a through hole is formed at a position of the second yoke 9 corresponding to the screw hole 11. 12 is formed, and the second yoke 9 is fixed to the first with the screw 13.
It was attached to the yoke 5.

[0006]

In the information recording / reproducing apparatus, the linear motor 4 is used in order to speed up the recording on the information card 1 or the reproducing from the card, and further to downsize the entire apparatus. It is necessary to use a linear magnet 6 having a high magnetic flux density. Therefore, a strong force having a complicated directional distribution of repulsion and attraction depending on the direction and strength of the magnetic flux of the linear magnet 6 acts on the second yoke 9 and the like.

Conventionally, therefore, the screw hole 11 and the through hole 12 are used.
And position and align the second yoke 9 with the screw 13
When attaching to the yoke 5, it was not easy to accurately align the screw hole 11 and the through hole 12 by receiving a strong force acting on the second yoke 9 and the like by the linear magnet. As a result, there is a problem that the assembly cost of the linear motor 4 becomes high.

Further, the screw 1 is used to facilitate the mounting.
Since it is necessary to use a screw made of a non-magnetic material as No. 3, there is a problem that the cost of parts of the linear motor 4 becomes high.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art and to easily attach the second yoke to the first yoke even under a strong force applied to the second yoke. Is to provide.

[0010]

In order to achieve the above object, a linear motor according to the present invention has a linear magnet disposed on a first yoke and support portions at both ends in the longitudinal direction 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, In a linear motor that moves the movable coil in the longitudinal direction of the linear magnet by an electromagnetic action of the magnetic field in the linear air gap, a concave or convex first fastening portion is formed on the upper portion of the support portion, and the second fastening portion is formed. Second convex or concave shape on the end of the yoke
A fastening portion is formed, the first fastening portion and the second fastening portion are fitted to each other, and the second yoke is attached to the first yoke.

[0011]

According to the present invention, the concave or convex first fastening portion formed on the upper portion of the support portion and the convex or concave second fastening portion formed at the end portion of the second yoke are fitted to each other. Since the second yoke is attached to the first yoke, it is not necessary to use a screw, and therefore, it is necessary to align the screw holes and screw them under a strong force received by the second yoke and the like. Therefore, 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 yoke of a linear motor 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 attached to the central portion of the first yoke 25. The linear magnet 26 has an N pole formed on the upper surface and an S pole formed on the lower surface. Rectangular block-shaped support portions 27, 27 are attached near the end of the linear magnet 26 in the longitudinal direction. 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 through holes 32 are formed near the ends in the longitudinal direction at positions corresponding to the positions 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 is arranged in a direction orthogonal to the direction of the magnetic field 35.
Due to the electromagnetic interaction between the electric current 37 flowing through 0 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. A leakage magnetic field 36 is generated near the end of the linear magnet 26. Between the end of the second yoke 29 in the longitudinal direction and the support portion 27, there is a strong directional distribution in which the magnetic field 35 and the leakage magnetic field 36 repel or attract each other depending on the leakage direction and strength. 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 then,
The through holes 32, 32 and the spring pins 33, 33 are aligned. Next, the second yoke 29 is attached to the supporting portions 27, 27.
To the through hole 32, 32 and the spring pin 33,
And 33. The through hole 3 is provided at a position separated from the upper surface of the linear magnet 26 by the length of the spring pins 33, 33.
Since the fitting between the springs 2, 32 and the spring pins 33, 33 can be started, the work can be performed in a state in which 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 is first aligned and lightly fitted, and then the second yoke 29 is rotated about the previously aligned spring pin 33 as an axis to set another pair. It is also possible to align and fit the through hole 32 and the spring pin 33.

According to the configuration of this embodiment, the support portion 27 is provided with the spring pins 33, 33 and the second yoke 2 is provided.
Since the through hole 32 is provided in the 9th, the second
The yoke 29 can be easily attached to the support portion 27. As a result, under the strong magnetic force exerted on the second yoke 29 and the like by the linear magnet 26, it is not necessary to align the screw holes and screw them as in the conventional case, and the second yoke 2
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 second embodiment of the present invention will be described with reference to FIG. In FIG. 2, the second yoke 29 has a second
A longitudinal hole 38 cut from the end face of the yoke 29 in the longitudinal direction is formed, and a lateral hole 39 cut from the end face of the second yoke 29 in the lateral direction is formed. .

The second yoke 29 is attached as follows. As shown in FIG. 2B, after the long hole 38 is fitted to one spring pin 33, the spring pin 33
The second yoke 29 is rotated about the axis to fit the lateral hole 39 and the other spring pin 33.

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

Next, a third embodiment of the present invention will be described with reference to FIGS. FIG. 5 is an exploded assembly view of a yoke of a linear motor that drives the optical head 3, FIG. 6 is a plan view showing the optical head 3 driven by this linear motor, and FIG. 7 is a view from BB in FIG. FIG.

In FIG. 5, a rectangular plate-shaped first yoke 2 is provided.
5 is bent at both ends and is integrally connected to the support portion 27. Notch parts 40, 40 are formed in the upper part of the support part 27 and are cut out in a rectangular shape. Second yoke 29
Rectangular protrusions 41, 41 that fit into the notches 40, 40 are formed at the ends in the longitudinal direction of the. The depth of the notches 40, 40 is equal to the thickness of the second yoke 29, and the length of the protrusions 41, 41 is equal to the thickness of the support 27. The length of the second yoke 29 in the longitudinal direction is determined by the inner end surface of the one support portion 27 and the other support portion 27.
Is formed to be equal to the distance from the inner end surface of the.

Next, the operation of this embodiment will be described. First, after inserting the movable coil 30 through the second yoke 29, the cutouts 40, 40 and the projections 41, 41 are aligned with each other, and the second yoke 29 is pressed against the support portions 27, 27 to cut the cutouts 40, 40. And the protrusions 41, 41 are fitted together.
At this time, at the same time, the side end surface of the second yoke 29 in the longitudinal direction contacts the inner surface of the support portion 27.

According to the structure of this embodiment, the notch 4
Since 0 and 40 and the protrusions 41 and 41 are provided, the second yoke 29 can be attached to the support portion 27 without using screws.

Further, the notches 40, 40 and the protrusion 4
Since the side end surfaces of the second yoke 29 in the longitudinal direction are brought into contact with the inner side surface of the support portion 27 at the same time when the first yoke 41 and the first yoke 41 are fitted, 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, the concave or convex first fastening portion formed on the upper portion of the support portion and the convex or concave shape formed on the end portion of the second yoke. Since the second yoke is attached to the first yoke by fitting the second fastening portion of the second yoke to each other, it is not necessary to use a screw, and therefore, the screw hole can be formed under a strong force received by the second yoke and the like. There is no need to align and screw
The second yoke can be easily attached to the first yoke.

[Brief description of 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 a positional relationship between the second yoke and the support portion, and (b) shows a procedure for fitting the second yoke to the support portion.

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

FIG. 4 is a vertical cross-sectional view as seen from AA in FIG.

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 the line BB in FIG.

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]

 25 1st yoke 26 Linear magnet 27 Support part 28 Linear gap 29 2nd yoke 32 Through hole 33 Spring pin 38 Longitudinal hole 39 Transverse hole 40 Notch part 41 Projection part

Claims (2)

[Claims] 1. A linear magnet is disposed on the first yoke, and support portions at both longitudinal ends of the first yoke are provided with:
A second yoke is mounted so as to form a linear gap with the linear magnet, and a current is passed through a movable coil wound so as to surround the second yoke through the linear gap,
In a linear motor that moves the movable coil in the longitudinal direction of the linear magnet by the electromagnetic action of this current and the magnetic field in the linear air gap, a concave or convex first fastening portion is formed on the upper portion of the support portion, and A convex or concave second fastening portion is formed at an end portion of the second yoke, and the first fastening portion and the second fastening portion are fitted to each other so that the second yoke is attached to the first yoke. A linear motor characterized by that. 2. The first fastening portion is a spring pin provided upright on the upper portion of the support portion, and one of the second fastening portions is cut in the longitudinal direction from an end face in the longitudinal direction of the second yoke. The second fastening portion is a lateral hole formed by cutting from the end face in the lateral direction of the second yoke in the lateral direction. The linear motor according to claim 1.