JPH0428066A - Head positioning mechanism for magnetic disk device - Google Patents

Abstract

PURPOSE:To obtain high head positioning accuracy and to perform assembling without generating dust by providing a means which fixes a rail on a holding member by interposing an elastic body. CONSTITUTION:The assembling of the rail 12 is performed by supporting the rail 12 with the holding member 13 by aligning a window 22 with a through hole 23, and fitting a compression coil spring 26 in the shaft 27 of a slide member 24. Thence, it is performed by inserting the shaft 27 to a through hole 21 from the outside of the holding member 13 passing through the through hole 23 and the window 22, and fitting a shaft member 24 in a hole 29 opened at the tip of the shaft from the end face of the rail 12. At this time, it is only enough to fit the sliding member 24, the coil spring 26, and the shaft 27. In such a manner, it is possible to perform the assembling without generating the dust in spite of the rail 12 made of ceramics, and to obtain the high head positioning accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a head positioning mechanism for a magnetic disk drive, and more particularly to a head positioning mechanism for a magnetic disk drive having an improved linear actuator.

[Prior Art] Conventionally, the linear actuator in this type of mechanism is
For example, JP-A-1-96877 and JP-A-61-1
As described in Japanese Patent No. 96475, a rail arranged in parallel, a holding member supporting the rail, a carriage arranged between the rails and holding a head assembly, and a carriage rolling on the rail. and an upper roller, the rail is arranged so that the mounting reference surface on the rail is in contact with the mounting reference surface of the holding member, the roller is in contact with the running surface on the rail, and the roller is placed in contact with the running surface on the rail. By moving the carriage while moving the head, the head is moved in a straight line, and the head is moved to the target position on the magnetic disk.

[Problems to be Solved by the Invention] In order to reduce wear, the rail is usually made of a material different from that of the holding member, such as hardened steel. Fixation to the holding member is achieved by screwing a screw into the rail through a through hole in the holding member. but,
When the temperature rises, the rail has a linear expansion coefficient different from that of the holding member, so thermal stress is generated, causing thermal deformation such as warping similar to bimetal. As a result, a discrepancy occurs between the head position for track positioning servo and the position signal on the disk, making it impossible to perform accurate head positioning.

Additionally, ceramic class materials are increasingly being used for the rails in order to roughly increase the positioning accuracy of the head. However, since screw holes cannot be provided in ceramic rails, through holes are provided in the rail and the holding member, and the rails are fastened with screws. In order to further reduce the mounting volume, the rail is made hollow, the shaft member is inserted into the through hole, and a screw is screwed into the shaft member through the holding member and the rail. However, with these methods, dust such as metal powder is generated when the screws are tightened, so the amount of floating spacing between the head and the magnetic disk is extremely narrow, causing problems in magnetic disk drives that require high cleanliness. There is a risk of causing Moreover, since the ceramic class has a larger difference in coefficient of thermal expansion than hardened steel, the above-mentioned problem of thermal deformation is even more severe.

An object of the present invention is to provide a head positioning mechanism for a magnetic disk drive that includes a carriage for mounting a head, a rail for guiding the carriage, and a holding member for supporting the rail. The object of the present invention is to make it possible to obtain high head positioning accuracy even when the head is made of materials having greatly different coefficients of linear expansion.

Another object of the present invention is that even if the rails are made of materials such as ceramics with significantly different coefficients of linear expansion, it is possible not only to obtain head positioning accuracy, but also to assemble the rails without generating dust. The goal is to make it possible to do it.

[Means for Solving the Problems] A head positioning mechanism for a magnetic disk device of the present invention includes a linear actuator including a carriage on which a head assembly is mounted, a rail for guiding the carriage, and a member for holding the rail. There is.

In order to achieve the above object, the head positioning mechanism for a magnetic disk drive of the present invention is provided with means for fixing the rail to the holding member through an elastic body.

In addition, in order to achieve the other objects mentioned above, the present invention provides a space provided inside the rail along the longitudinal direction of the rail, and a contact surface of the rail with a holding member connected to this internal space. a window provided in the holding member, a hole provided in the holding member corresponding to the window, a first member inserted into the internal space, one end connected to the first member and the other end passed through the window. a second member extending into the hole of the holding member and having a spring receiver in the extension; and a second member disposed between the holding member and the first member in order to obtain a force for crimping the first member to the rail. The rail is fixed to the holding member by the elastic body.

If a very clean condition is required, the first member and the second member are connected by hoop-fitting them, but they can also be connected by screw connection. For example, a compression coil spring or a leaf spring can be used as the elastic body. If it consists of a coil spring,
For example, the second member may be provided with a spring receiver at a portion that receives the spring from the through hole, and the coil spring may be arranged between the spring receiver and a spring seat formed around the through hole. can. In the case of a leaf spring, for example, the second member has a spring receiver at the part that receives the spring from the through hole, the leaf spring is arranged across the through hole, and the second member has a spring receiver at the lower part of the spring receiver. The member may be engaged with the member.

[Operation] In the former head positioning mechanism, the rail is fixed to the holding member by the elastic body pressing the first member against the wall surface forming the internal space of the rail and press-fitting the rail to the holding member. As a result, the frictional force at the contact surface or point of contact between the rail and the holding member is reduced within a range that does not affect the positioning accuracy of the rail. When the environmental temperature changes, sliding occurs between the rail and the holding member, allowing them to extend separately.

The latter head positioning mechanism includes, for example, a state in which the first member is placed in the internal space and the elastic body is placed between the second member and the holding member, and the second member is passed through the window through the through hole. By inserting the first member into the internal space and engaging the first member with the second member, the rail can be fixed even without a screw connection. As a result, the frictional force at the contact surface or point of contact between the rail and the holding member is reduced to the extent that it does not affect the positioning accuracy of the He/Rad, and when the environmental temperature changes, the frictional force between the rail and the holding member is reduced. Can cause slippage.

[Embodiment] An embodiment of the head positioning mechanism for a magnetic disk device of the present invention will be described below with reference to FIGS. 1 to 8.

In this head positioning mechanism, the linear actuator includes a head assembly 10, as shown in FIG.
It includes a carriage 11, a rail 12, a holding member 13, a voice coil 14, and a magnetic sotring 15.

The head assembly 10 includes a head for recording and reproducing and a mechanism for floating the head, and is supported by a carriage 11. Although only one is shown in the drawing, in reality, for example, ten helad assemblies are attached to the carriage 11 so that two of them face each other.

Although the disks are not shown, they are respectively arranged between the disks and the disks facing each other, and their rotating shafts are held in the frame of this disk device.

The carriage 11 is equipped with rollers made of rolling bearings on its sides. There are four rollers at the front end and four rollers at the rear end of the carriage, and the shafts supporting the four rollers are arranged on the carriage at right angles to each other. In the drawing, two rollers in the leading end roller group are designated by 16, and two rollers in the trailing end roller group are designated by 1-.
7.

The rail 12 is disposed such that one end is supported by the holding member 13 and a free end passes through the inside of the voice coil.

The rail itself is made of ceramic class, and has two mounting reference surfaces 18 made of flat surfaces arranged at right angles to each other.
and running surfaces 19 separated by an angle of 90°. The holding member 13 is fixed to the frame of this magnetic disk device.

The holding member itself has a concave shape with an opening facing upward, and has two mounting reference surfaces 20 formed of planes arranged at right angles to each other in the parts forming the two columns. Equipped with

The rail 12 is attached to the holding member 13 with the reference surface 18 in contact with the reference surface 20 of the holding member.

The carriage 11 has four rollers 16 .
17 on the running surface 19 of one rail 12, the roller 16 on the opposite side and the two rollers forming the roller group, and the roller 17 and the two rollers forming the roller group on the running surface of the other rail. These rollers are arranged in contact with each other, and the carriage can be moved by moving these rollers on the rails.

The voice coil 14 is attached to the rear end of the carriage 11 and arranged inside a magnet ring 15 fixed to the frame. Control is performed by a so-called servo surface servo that reads track position information written on some disks by a head associated with this disk and outputs it to voice coil motor control means.

In this linear actuator, the rail is fixed to the holding member so that it can slide only in the longitudinal direction when thermally expanded. explain in detail.

The rail 12 includes an interior space 21 and a window 22, as best shown in FIGS. 2 and 3.

The internal space 21 includes, for example, a through hole provided along the longitudinal direction of the rail 12. The windows 22 are arranged on the rail 1 such that, for example, there are two windows 22, each connected to the through hole 21 and located at right angles thereto.
It is provided in 2. Further, the holding member 13 is provided with a through hole 23 located at the joint portion of the attachment reference surface 20 and open to this reference surface and the outer surface of the holding member. There are two through-holes 23 along the joint, and each through-hole is spaced in the holding member at a spacing that corresponds to the spacing of the windows 22 in the rail.

Further, a shaft member 24 is arranged in the inner space of the rail or the through hole 21, and a slide member 25 is arranged in the window 22 and the through hole 23 of the holding member. The shaft member 24 has the form of an elongated bottle whose diameter is considerably smaller than the inner diameter of the through hole 21. The slide member 25 consists of a shaft 27 and a spring receiver 28 provided at the rear end of the shaft.
A hole 29 larger than the diameter of the shaft member is provided.

In this case, the rail 12 is placed on the holding member 13 with the window 22 aligned with the through hole 23. The slide member 26 is inserted into the through hole 23 and the window 22 such that the tip of the shaft 27 extends into the through hole 21 . The coil spring 26 is inserted into the slide member so as to be located between a spring seat 30 formed inside the through hole 23 of the holding member and a spring receiver 28 of the slide member. The coil spring is of a compression type, and pulls the slide member 26 downward, presses the shaft member 24 against the rail 12, and presses the rail 12 against the holding member 13. Therefore, the rail 12 is prevented from moving in all directions by these members and the mounting reference surface of the holding member 13.

This linear actuator will
A relative thermal expansion difference occurs between the rail 12 and the holding member 13. However, the rail 12 is pressed against the holding member 13 by the coil spring 26, and the friction coefficient between them is smaller than that of the conventional screw-coupled rail 12, so the rail 12 resists the spring 26 and is heated. There will be an amount of slippage related to the differential expansion. Therefore, the rail does not undergo thermal deformation such as warping, and the relationship between the head for track positioning servo and the position signal on the disk does not change with respect to the positional relationship between other disks and heads. positioning can be performed with mutual precision.

Moreover, in this linear actuator, the rail 12
To assemble, align the window 22 with the through hole 23, support the rail 12 on the holding member 13, fit the compression coil spring 26 on the shaft 27 of the slide member 24, and insert the shaft 27 into the through hole from the outside of the holding member 13. 23 and the window 22 into the through hole 21, and the shaft member 24 is fitted from the end surface of the rail 12 into the hole 29 at the tip of the shaft. At this time, each of the slide members, coil springs, and shaft members only needs to be fitted in one place, so even though the rail 12 is made of ceramic class, no dust is generated. Assembly work can be done. Then, in the assembled linear actuator, the shaft member 24, slide member 25, and spring 26 are attached to the rail 1.
2 and the holding member 13, and the carriage 1
1, the mounting volume can be maintained.

Figures 4 and 5 show other rail fixing means.

The rail 12 has a through hole 21 and a window 22.

The holding members 13 each have a through hole 23. The shaft member 24 also has the form of a pin, and is inserted into the through hole 21 of the rail. The slide member 25 also has a shaft 27 and a spring receiver 28, and the shaft 27 is fitted to the slide member 25 through the window 22. coil spring 26
is arranged between the seat 31 in the through hole 23 of the holding member and the spring receiver 29 of the slide member.

However, in this rail attachment method, a unit that further reduces friction is arranged on the contact surface of the holding member 13 with the rail. This unit consists of a ball 33 and a retainer. The retainer beam includes a holding plate 34 and a base plate 35 having a four-shape shape. Holding plate 3
4 is fixed to the substrate 35. The holding plate and the base plate have two through holes 3, as best shown in FIG.
6 is provided. These through holes 36 are arranged at intervals corresponding to the intervals between the windows 22 of the rail and the intervals between the through holes 23 of the holding member. The ball 33 is fitted into a hole 37 in the holding plate 34. The openings at both ends of the hole 37 are given a smaller diameter than the ball 33,
Leaving the ball out prevents it from coming out.

This unit is placed between the rail 12 and the holding member 13 with the retainer holes 36 aligned with the windows 22 and through holes 23 and the balls 33 in contact with the rails 12. The slide member 25 has a through hole 23 and a retainer hole 36.
The coil spring 26 is fitted to the shaft member 24 through the window 22, and the coil spring 26 is disposed between the seat 31 in the through hole 23 of the holding member and the spring receiver 29 of the slide member 25. The movement of the rail is prevented by pressing the shaft member 24 against the rail 12 and pressing the rail 12 against the holding member 13 with the ball 33 interposed.

In a linear actuator with such a unit,
Similar to the above-mentioned means, the rail 12 does not slide against the spring 26 even if the environmental temperature changes, and not only does the rail not become thermally deformed, but also the friction between the rail 12 and the holding member 13 is smaller. Therefore, the rail can slide more smoothly.

FIG. 6 shows another rail fixing means in which the balls are arranged on the contact surface between the rail 12 and the holding member 13.

In this, the ball is indicated by reference numeral 133 and is arranged between the holding member 13 and the rail 12. but the ball is not held by the retainer,
The position is fixed by a magnet 41. These magnets are inserted and fixed into blind holes 40 provided in the holding member 13 corresponding to the balls 133. The inverted-shaped member 39 placed between the ball and the holding member is for smooth rolling of the ball, and similarly to the retainer, the space between the windows 22 of the rail and the through hole 23 of the holding member is adjusted. The through-holes are arranged at intervals corresponding to the interval. The slide member 25 is fitted to the shaft member 24 through the through hole 23 , the hole in the member 41 and the window 22 , and a compressed coil spring 26 is inserted into the seat 3 in the through hole 23 .
1 and the spring receiver 28 of the slide member 25.

This linear actuator, like the ones in FIGS. 4 and 5, can also reduce the friction between the rail 12 and the holding member 13, so when the environmental temperature changes, the rail can be heated more smoothly. It can be transformed.

Note that this rail mounting may be accomplished by placing a viscous substance between the balls 33. By doing so, the viscous material layer absorbs vibrations of the rail 12 when the carriage 11 travels, thereby eliminating head crashes and making it possible to construct a more reliable magnetic disk device.

FIG. 7 shows yet another rail attachment means.

This means differs from those shown in FIGS. 2 to 6 only in the shaft member and slide member.

The shaft member 124 is made of a member having a larger diameter than shaft members in other means, and has a screw hole 4 on the circumferential surface.
2 is provided. There are two screw holes in the longitudinal direction.
They are arranged at intervals corresponding to the windows 22 of the rail and the through holes 23 of the holding member. The slide member 125 has a shaft 127 and a spring receiver 128, and the tip of the shaft 127 is provided with a male thread related to the screw hole 42.

This slide member has a shaft 127 that is connected to the through hole 23 and the window 2.
2 into the internal space 21 of the rail, and the tip of a shaft 127 is screwed into the shaft member 124. The compression type coil spring 26 is arranged between the seat 31 in the through hole 23 and the spring receiver 128 of the slide member. rail 12
The spring 26 presses the shaft member 124 against the rail 12,
By crimping the rail 12 to the holding member 13,
Movement is stopped.

FIGS. 8 and 9 show still other rail fixing means.

In this case, the shaft member and the slide member are constructed similarly to those shown in FIG. 7, but the spring is a leaf spring 126.
It consists of

The shaft member 124 is inserted into the through hole 21, and the slide member 1
25 is inserted into the through hole 21 through the through hole 23 and the window 22, and its tip is screwed into the shaft member 124. The leaf spring 126 is attached to the holding member 13 by the screw 43.
and the notch 44 at the free end is located at the bottom of the spring receiver 128.
It is engaged with the shaft 128 of the slide member 125. The rail is stopped in motion by leaf spring 126 pressing shaft member 124 against rail 12 and pressing the rail against retaining member 13 .

FIG. 10 shows yet another means of mounting the rail.

The rail 12 is provided with through holes 21 and windows 22, as well as other rail attachment means. The holding member 13 is also provided with through holes 23 that correspond to each of the windows 22 when the rail 12 is attached. The shaft member 224 is inserted into the through hole. However, the member on the holding member side consists of a member 45 in the form of a bottle. The member 45 has the through hole 23
It is arranged on the outer surface of the holding member 13 so as to cross the . A tension coil spring 126 is arranged inside the window 22 and the through hole 23, and has one end connected to the shaft member 2.
24, and the other end is engaged with member 45. rail 12
The spring 26 presses the shaft member 224 against the rail 12,
Movement is stopped by crimping the rail to the holding member 13.

This linear actuator also includes a rail 12 and a holding member 1.
3 can reduce friction, allowing the rail to slide smoothly when the environmental temperature changes.Moreover, the structure is simpler than other fixing means, reducing costs. be able to.

In the embodiments described above, the rails are arranged in parallel, and the carriage is arranged between the rails so that the rollers roll on these rails, but linear actuators with other arrangements can also be used. Similar effects can be obtained by employing Tosukumono as the rail fixing means described in these embodiments.

[Effects of the Invention] According to claim 1, in the head positioning mechanism of the magnetic disk drive of the present invention, since the frictional force at the contact surface or contact point between the rail and the holding member is small, It prevents heat deformation of the rail and allows head positioning to be performed with mutual precision.

According to claim 2, since the frictional force at the contact surface or contact point between the rail and the holding member is small, it is possible to prevent thermal deformation of the rail due to the difference in linear expansion coefficients and to position the head with high precision. Not only is this possible, but the rail can be fixed simply by inserting it, so the rail can be fixed to the holding member without generating dust. Regardless of the material used, a highly reliable magnetic disk device can be constructed.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view showing an embodiment of the linear actuator for a magnetic disk drive of the present invention, Fig. 2 is a vertical cross-sectional view of the portion where the rail is fixed to the holding member, and Fig. 3 is a cross-sectional view. It is. FIG. 4 is a cross-sectional view showing another configuration of the portion fixing the rail to the holding member, and FIG. 5 is a perspective view showing details of a unit disposed between the rail and the holding member. FIG. 6 is a cross-sectional view showing still another structure of the part that fixes the rail to the holding member, FIG. 7 is a cross-sectional view showing still another structure of the part that fixes the rail to the holding member, Fig. 8 is a cross-sectional view showing still another configuration of the part that fixes the rail to the holding member, and Fig. 9 is an arrow A in Fig. 8.
FIG. 10 is a front view of some of the members as seen from the direction of FIG. DESCRIPTION OF SYMBOLS 10... Head assembly, 11... Carriage, 12... Rail, 13... Holding member, 21...
Internal space, 22... window, 23... through hole, 24.1
24.224...first member, 25.125.45.
...Second member, 26.126...Elastic body.

Claims (1)

[Claims] 1. In a head positioning mechanism of a magnetic disk drive that includes a carriage on which a head assembly is mounted, a rail for guiding the carriage, and a member for holding the rail, an elastic body is used. 1. A head positioning mechanism for a magnetic disk drive, comprising means for intervening to fix a rail to a holding member. 2. In a head positioning mechanism of a magnetic disk drive that includes a linear actuator including a carriage on which a head assembly is mounted, a rail for guiding the carriage, and a member for holding the rail, means for fixing the rail to the holding member is provided. , a space provided inside the rail along the longitudinal direction of the rail, a window provided on the contact surface of the rail with the holding member so as to be connected to this internal space, and a holding member corresponding to the window. a hole provided, a first member inserted into the interior space, one end connected to the first member, the other end extending through the window into the hole of the holding member, and having a spring receiver in the extension portion. A head positioning mechanism for a magnetic disk drive comprising a second member and an elastic body disposed between the holding member and the first member to obtain a force for pressing the first member against the rail. 3. The second member has a spring receiver at a portion receiving the spring from the through hole, and the elastic body is made of a compression type coil spring and is arranged between the spring receiver and a spring seat formed around the through hole. A head positioning mechanism according to claim 2. 4. The second member has a spring receiver at the part that receives the spring from the through hole, and the elastic body is made of a leaf spring and is arranged across the through hole, and the second member is connected to the second member at the lower part of the spring receiver. A head positioning mechanism according to claim 1 in which the head positioning mechanism is engaged.