JPH0513215A - Yoke for magnetic-circuit formation use - Google Patents

Abstract

PURPOSE:To constitute the title yoke wherein it can be assembled easily and it is set to a proper state without executing any posterior working operation or the like after it has been assembled. CONSTITUTION:Sheet-metal members 42 in which recessed parts 43 for boss pressing-in use and bosses 44 have been formed so as to be faced on both faces of the sheet-metal members are coupled to each other in such a way that each boss 44 on each sheet-metal member 42 on the other side is pressed in and fitted to each recessed part 43 for boss pressing-in use of each sheet-metal member 42 on one side. Each sheet-metal member in which only a hole for boss pressing-in use has been formed is coupled to the sheet-metal members coupled in this manner and is set to a state that each boss does not protrude. Thereby, the sheetmetal members can be coupled to each other, stacked and united without a need for other members for coupling use and without a need for a posterior working operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a yoke for forming a magnetic circuit used in an optical information recording / reproducing apparatus or the like.

[0002]

2. Description of the Related Art Magnetic circuit forming yokes are used in various magnetic circuit forming locations. For example, in an optical information recording / reproducing apparatus, it is used in a head feeding mechanism having a carriage. This yoke for forming a magnetic circuit is formed by various forming methods. Forming methods include cutting, die casting, sintering, lamination of sheet metal parts, etc. Among them, the method of laminating sheet metal parts is low in part cost and relatively free to select a two-dimensional shape. It is widely used because it can be done.

FIG. 9 shows a yoke formed according to the conventional method. After the sheet metal members 60 are stacked,
Forming through holes 61 in the sheet metal member stacking direction at predetermined two positions,
The pin 62 is press-fitted into the through hole 61 and then caulked to form a yoke. Further, in FIG. 10, the through holes 61 are formed after stacking a plurality of sheet metal members 60 in the same manner as the forming method shown in FIG. Instead, the yoke is fixed by fixing it to the base 63 with the screw 62.
The present applicant also discloses a magnetic circuit used in an optical information recording / reproducing apparatus in Japanese Patent Application No. 2-133880. Here, it is disclosed that five plate materials having a thickness of about 1.6 mm are laminated, holes are formed in the vicinity of both ends in the longitudinal direction, and pins are press-fitted therein to form a yoke.

[0004]

However, among the conventional examples shown in FIG. 9, the through holes are formed in the sheet metal member stacking direction in order to press-fit the pins, but in this case, the hole diameter tolerance is strictly required. There is also a need for post-processing. Moreover, a pin that is a component for connecting the sheet metal members is required. Further, a jig for press-fitting the pin is required, and the amount of press-fitting is large, which makes work difficult. Further, when the pin is press-fitted, the length of the pin may have to be adjusted depending on the plate thickness of the sheet metal member and the variation in the gap between the sheet metal members, which may require processing after the press-fitting.

On the other hand, the one shown in FIG.
It is difficult to assemble because the sheet metal members are disassembled until they are fixed to the space. Further, when it is necessary to attach a magnet or the like to the yoke, it is necessary to join the sheet metal members together by some method. If the sheet metal members to be laminated are not provided with any positioning means, the sheet metal members will be displaced from each other when they are fixed to the base, resulting in a step on the end face. The present invention has been proposed to solve the above problems, and provides a yoke for forming a magnetic circuit which is easy to assemble and which is formed in an appropriate state without post-processing etc. after the assembly. It is intended for.

[0006]

In order to achieve the above object, the present invention provides a magnetic circuit forming yoke formed by laminating a plurality of sheet metal members, in which a boss press-fitting recess and a boss are provided at predetermined positions. The sheet metal members formed so as to correspond to each other on both sides were made into a magnetic circuit forming yoke in which the boss press-fitting recesses of one sheet metal member were press-fitted and joined to the bosses of the other sheet metal member. Further, in a magnetic circuit forming yoke formed by laminating a plurality of sheet metal members, a boss press-fitting recess and a boss are formed at predetermined positions so as to correspond to each other on both sides of the sheet metal member.
Sheet metal member and a second sheet metal member having only a boss press-fitting hole portion formed at a predetermined position, and the plurality of first sheet metal members are placed in the boss press-fitting recesses of one sheet metal member and the other sheet metal member. The bosses of the first sheet metal member are press-fitted and joined to each other, and the bosses of the first sheet metal member are press-fitted and joined to the bosses of the second sheet metal member to form a magnetic circuit forming yoke.

[0007]

In this way, since a plurality of sheet metal members are integrally laminated through the boss press-fitting recess or hole formed in the sheet metal member itself and the boss, no other member is required, and It can be assembled easily and properly without requiring post-processing.
Therefore, a high-quality magnetic circuit forming yoke can be easily produced at low cost.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings. In the following embodiments, a magnetic circuit forming yoke used in an optical head driving device of an optical disk device will be described. FIG. 1 is an exploded perspective view of a part of an optical disk device, in which a fixed optical system having a light source and the like and a driving optical system having an objective lens and the like are incorporated. A spindle motor 2 for driving a disk is provided at a substantially central position of a deck base 1 formed of a metal such as aluminum, and a fixed optical system 3 is provided outside a lengthwise end of the deck base 1. Is provided.

Mounting bases 4 and 5 and the other mounting bases 6 and 7 are provided on both sides in the vicinity of the spindle motor 2, respectively. The inner bases are located near the spindle motor 2 through these mounting bases. -Yoke 8 and outer yoke 9 on the outside
Is attached. A magnet 10 is arranged between the inner yoke 8 and the outer yoke 9 to form a magnetic circuit. A short pipe 11 having a square cross-section and made of a copper material is attached to the inner yoke 8 so as to cancel a magnetic flux loss due to an eddy current generated from a magnetic circuit. Similarly, each member for forming a magnetic circuit is provided on the other mounting bases 6 and 7, but the illustration thereof is omitted.

Each of the above yokes is formed by stacking five sheet metal members having a thickness of about 1.6 mm, and a short pipe 11 is attached to the center and outer circumference of the inner yoke 8. . The outer yoke 9 and the inner yoke 8 are formed so as to engage with each other at both ends of the inner yoke 8. If one yoke is fixed and the other is engaged. Can be easily positioned. A reinforcing plate 12 is provided between the above two magnetic circuit forming portions to fix the flexible cable and to close the hole of the deck base described later. Further, a magnetic scale 13 for a speed sensor is provided on the deck base 1 formed on the reinforcing plate 12 at the position of the notch.

FIG. 2 is an exploded perspective view of the vicinity of the head feeding mechanism. The head feed mechanism has the inner yoke 8, the outer yoke 9, and the magnet 10 described above, and a coil body wound around the outer circumference of the short pipe 11 attached to the inner yoke 8.
14 are arranged. A driving force is generated by supplying an electric current to the magnetic circuit thus formed. The other magnetic circuit is also formed in the same manner, but not shown except for the coil body 15. Between a pair of magnetic circuits facing each other, guide rails 16 and 17 are fixed by a plurality of rail restraints 39 and extend in parallel.

Insertion holes 19 and 20 for the guide rails 16 and 17 are formed on both sides in the Y direction which is orthogonal to the X direction, which is the moving direction of the carriage 18. Further, adhesive injection holes 18a are formed at both ends of the carriage 18 in the Y direction, and the coils 14 and 15 are fixed to the carriage 18 by the adhesive injected from the holes 18a. When a current is supplied to the coils 14 and 15, a guide rail is provided via six rotating rollers 24 (only five are shown in the drawing) provided on the outer side of the carriage 18 by the action of the magnetic circuit. It is designed to move along 16 and 17. In addition, the coil 1 on the carriage 18
To fix 4 and 15, the inside of the coils 14 and 15 is held by a jig, positioned with respect to the carriage, and an adhesive (not shown) is formed with a clearance of about 0.1 mm formed between them. No.) is injected and fixed through the adhesive injection hole 18a.

Since the coils 14 and 15 are directly fixed to the carriage 18 by the above method, the coils 14 and 15 do not need bobbins, and the carriage 18 is electrically conductive because an adhesive having an insulating property is used. Even if it has a property, it is not necessary to interpose an insulating film or the like. Further, since the inner diameter of the coil is accurately formed by a jig, it is easy to adjust the position of the coil and the carriage 18, and it is difficult for the coil, the short pipe and the magnet to come into contact with each other, and the mutual distance can be reduced. The magnetic flux density in the gap can be increased to improve drive sensitivity. A guide rail is installed inside the carriage 18.
A pressurizing spring 30 for holding a bearing 29 for pressurizing the carriages 16 and 17 is provided so that the carriage 18 can move smoothly along the guide rails 16 and 17.

Further, four shock absorbing dampers 25 are provided on both sides of the carriage 18 in the X direction. An actuator 21 is mounted and fixed on the carriage 18.
It is designed to move integrally with the carriage 18. An objective lens 22 is movably provided above the actuator 21, and a light beam from a fixed optical unit (not shown) reaches here via a reflecting prism 40 and converges as a light spot on the optical disc. Let In addition, the actuator 21
A dust-proof cover 23 is provided on the upper part of the.

A flexible cable for electric power is attached to the carriage 18.
A flexible cable 27 and a flexible signal cable 27 are mounted on the deck base 1 and the flexible cable 27.
It is fixed on the deck base 1 by a reinforcing plate 12 having a thickness of about 1 mm while being largely curved toward (see FIG. 1). The flexible cable 27 is connected to the reinforcing plate 12, and its end 41 is a hole formed in the deck base 1.
Thread downward from 1a (see Figure 1). The plate 1a is a reinforcing plate 12
It is sealed in. Further, the flexible substrate and the flexible cable are all integrated and bent.

The power flexible cable 26 is further actuated to supply current to the head feed mechanism.
This is for supplying an electric current to the tracking coil and focusing coil of the computer. The flexible signal cable 27 is for supplying a signal from the tracking position sensor 31 of the actuator, and further for supplying a signal from the hall element. The thickness of these flexible coils is about 0.15 mm. The flexible cable is provided by utilizing a space between the guide rails, and an optical path of an optical system is provided between the flexible cables.

Inner yoke 8 and outer yoke 9 used in this apparatus
Will be constructed by stacking sheet metal members. The case where the outer yoke 9 is constructed according to FIG. 3 will be described. First, all five sheet metal members 42 are formed in the same shape, but a steel plate having a plate thickness of 1.6 mm is formed by pressing. In this case, at the same time as removing the outer shape, half-cutting processing is performed so that the boss press-fitting recesses 43 and the bosses 44 are formed at one position on each side of the sheet metal member 42. For the boss press-fitting recess 43 and the boss 44, the boss 44 is simultaneously formed by forming the boss press-fitting recess 43.
Located at the corresponding positions on the front and back of 42. As shown in FIG. 4, the size of this semi-cut processed portion is a recess for boss press fitting.
The diameter D1 of 43 is φ1.98-2 mm, the diameter D2 of the boss 44 is φ2-2.
It is formed within the range of 02 mm variation. The two have a relationship of D2 ≧ D1.

The sheet metal member 42 thus formed is
Since the outer shape processing and the half-cutting processing are performed with the same press die, there is almost no dimensional deviation between the individual sheet metal members 42.
Therefore, when the outer shapes of the individual sheet metal members 42 are guided and overlapped with each other, the semi-cut portions are exactly overlapped. When pressed in this state, since the boss press-fitting recess 43 and the boss 44 have the above-described relationship, the former is press-fitted into the former and they are integrated in a laminated state as shown in FIG. In addition,
As long as the above press-fitting work is easily performed and a proper stacked state can be realized, the dimensional relationship between the diameter D1 of the boss press-fitting recess 43 and the diameter D2 of the boss 44 is not limited to the above. Needless to say.

According to this embodiment, when the sheet metal members are laminated and integrated, it is easy to simply press the sheet metal members together without using the conventional means of press-fitting pins or the like into the through holes. You can do it. In addition, since the individual sheet metal members are formed in advance by the same press die, there is no variation, and even if the layers are integrated, there is no need for post-processing or finishing of the members in a displaced state.

Next, a second embodiment of the present invention will be described. In this embodiment, the present invention is applied to the inner yoke 8 described above. As shown in FIG. 2, a magnet 10 is provided between the inner yoke 8 and the outer yoke 9 to form a magnetic circuit.
In this case, it is necessary to reduce the gap size between the magnet 10 and the inner yoke 8 to increase the magnetic flux density in the gap. on the other hand,
In order to cancel the magnetic flux loss due to the eddy current, the inner yoke 8 is provided with a short pipe 11 on the outer periphery of the central portion of the inner yoke 8, and the coil 14 is further provided outside thereof.

The inner yoke 8 is constructed in this way, but when the sheet metal members are laminated as in the case of constructing the outer yoke 9, the boss 44 extends from the sheet metal member surface as shown in FIG. It will be in a protruding state. When the boss 44 projects, the short pipe 11 is provided on the outer periphery of the central portion of the inner yoke 8 so as to cover the longitudinal end portion of the inner yoke 8 (see the state of FIG. 2). The short length of the short pipe 11 must be large enough to allow the boss 44 to escape. However, if the short pipe 11 is configured in this way, the gap is widened by that amount and the performance of the magnetic circuit is deteriorated. Therefore, when forming the inner yoke 8, it is necessary to eliminate the projection of the boss 44 as shown in FIG.

Therefore, in the present embodiment, as shown in FIG. 6, among the five sheet metal members, four sheet metal members 42 are punched out from the outer shape by pressing a steel plate having a thickness of 1.6 mm as in the first embodiment. At the same time, the boss press-fitting recess 43 and the boss 44 are formed by half-cutting. In this case, the boss press-fitting recess 43 and the position and number of bosses 44 to be formed are the same as in the first embodiment. Further, the diameter of the boss press-fitting recess 43 is set to D1, and the diameter of the boss 44 is set to
When D2 is set, D1 is φ1.98 to 2 mm, D2 is φ2 to 2.02 mm, and D2 ≧ D1.
Similar to the first embodiment, since the sheet metal members 42 are formed by the same press die by the outer shape and the half-cutting process, there is almost no dimensional deviation between the members.

Next, the fifth sheet metal member among the sheet metal members.
A hole 46 is simply formed in a position corresponding to a boss of another sheet metal member 42 without forming a boss in the 45, and is used as a boss press-fitting position. As shown in FIG. 7, when the diameter of the hole 46 of the sheet metal member 45 is D3, D3 is configured within the range of variation of φ1.98 to 2 mm, and is between the diameter D2 of the boss 44 formed on the sheet metal member 42. To D2 ≧
It is configured to have a D3 relationship. Also, sheet metal member
Since the outer shape of 45 is the same as that of the other sheet metal member 42, the hole 46
The same press die can be used because the punch can be formed by simply exchanging the punch for semi-cutting of the press die for processing the sheet metal member 42 with the punch for punching. Therefore,
The dimensional deviation between the sheet metal member 45 and the sheet metal member 42 hardly occurs.

As described above, in the present embodiment, the inner yoke 8 is constructed by using two kinds of members, that is, the sheet metal member 42 and the sheet metal member 45. First, the outer shape of the sheet metal member 42 is aligned as a guide. After the sheet metal members 42 are superposed on each other, the sheet metal member 45 is superposed on the surface side of the sheet metal member 42 projecting from the boss 44 side.
Then, since there is almost no dimensional deviation between the members, the boss 44 of each member, the recess 43 for the boss, and the hole 46 are almost exactly overlapped with each other. When pressing from the sheet metal member stacking direction in this state, the size of each part is D2 ≧ D1, D2 ≧ D3 as described above, so the boss 44 is press-fitted into the boss press-fitting recess 43 and the hole 46. As shown in FIG. 8, the five sheet metal members are integrated in a laminated state.

According to this embodiment, when the sheet metal members are integrally laminated, the sheet metal members can be easily pressed by simply pressing each other without using the conventional means of press-fitting the pins or the like into the through holes. You can do it. In addition, since the individual sheet metal members are formed in advance by the same press die, there is no variation, and even if the layers are integrated, there is no need for post-processing or finishing of the members in a displaced state. Further, since the boss can be configured so as not to project from the sheet metal member, the short pipe can be provided without widening the gap, and the performance of the magnetic circuit is not deteriorated.

[0026]

As described above, according to the present invention, in forming a yoke by laminating a plurality of sheet metal members, the sheet metal members can be connected to each other without using other parts, so that the parts cost and the assembly cost can be increased. Can be reduced. Further, since the precision of each sheet metal member can be realized by press working, post-processing is unnecessary and the production cost can be reduced. Further, since the respective sheet metal members can be formed by the same press die, the shapes can be made uniform, the subsequent handling becomes easy, and the number of assembling steps can be reduced. Further, since the sheet metal members are integrated in a laminated state, subsequent assembly can be easily performed. Further, after stacking the sheet metal members, there is no displacement between the members and there is almost no step on the end face, and a high quality yoke can be efficiently produced.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a part of an optical disc device to which the present invention is applied.

FIG. 2 is an exploded perspective view of the vicinity of a head feeding mechanism of the optical disk device.

FIG. 3 is an exploded side view of a sheet metal member constituting the outer yoke according to the first embodiment of the present invention.

FIG. 4 is a partial cross-sectional view of the sheet metal member.

FIG. 5 is a side view of the outer yoke integrated and laminated.

FIG. 6 is an exploded perspective view of a sheet metal member forming an inner yoke according to a second embodiment of the present invention.

FIG. 7 is a partial cross-sectional view of the sheet metal member.

FIG. 8 is a side view of the inner yoke that is laminated and integrated.

FIG. 9 is a side view of a yoke according to a conventional example in a partially cross-sectional state.

FIG. 10 is a side view of another yoke according to the conventional example in a partially cross-sectional state.

[Explanation of symbols]

42 Sheet metal member 43 Boss press-fitting recess 44 Boss

Claims (2)

[Claims] 1. A magnetic circuit forming yoke formed by laminating a plurality of sheet metal members, wherein one sheet metal member is formed by forming a boss press-fitting recess and a boss at a predetermined position so as to correspond to each other on both sides of the sheet metal member. A yoke for forming a magnetic circuit, characterized in that the boss of the other sheet metal member is press-fitted and fitted into a boss press-fitting recess of the member. 2. A magnetic circuit forming yoke formed by laminating a plurality of sheet metal members, wherein: a first sheet metal member in which a boss press-fitting recess and a boss are formed at corresponding predetermined positions on both sides of the sheet metal member. , A second sheet metal member having only a boss press-fitting hole formed at a predetermined position,
The plurality of first sheet metal members are coupled to each other by press-fitting the bosses of the other sheet metal member into the boss press-fitting recesses of the one sheet metal member, and further connecting the first sheet metal members to the boss press-fitting holes of the second sheet metal member. A yoke for forming a magnetic circuit, characterized in that the bosses of the sheet metal members are press-fitted and joined together.