JPS6224483A - Linear guide mechanism for magnetic disc device - Google Patents

Abstract

PURPOSE:To make it difficult that the read/write error due to external oscillation and thermal deformation occurs, by specifying the arrangement of six rolling wheels, which support a carriage, and the direction of the force which supports the carriage and applying a prepressure to a proper position. CONSTITUTION:A guide arm 12 which supports a magnetic head 11 is coupled to a carriage 4, and a voice coil 14 is coupled to the carriage 4. Six rolling wheels 2 are arranged on side faces of the carriage 4 as supporting points, and five rolling wheels 2 have inner wheels fixed to the carriage 4, and one rolling wheel 2a is engaged with the carriage 4 through a flat spring 3, and positional relations between the carriage body and a rail 1 are determined by fixed rolling wheels 2. Since such supporting structure is constituted that the outward motion of the carriage 4 on the surface of a disc 13 is supported rigidly and the inclination around the (y) axis is difficult to occur and the supporting force acts outward with a plane parallel with the disc 13 as the boundary, the restorability for meandering motion is improved. Since the prepressure is applied to the center, the inclination around the (y) axis due to thermal deformation is small to make the occurrence of read/write error difficult.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a magnetic disk drive, and more particularly to a linear guide mechanism for a magnetic disk drive that linearly moves a magnetic head.

[Background of the invention]

A head drive mechanism in a magnetic disk drive requires smooth movement and accurate positioning.

In the linear guide method, particularly accurate linear movement is required. If the head deviates from a fixed straight line on its way to the target track, for example, if it twists around the access direction, the head movement will also deviate from linear translation, and in the worst case, it will collide with the disk. There is a risk of Furthermore, residual vibrations caused by the deviation impair positioning accuracy and slow settling time.

In order to achieve accurate linear motion, conventional methods have been developed, such as Japanese Utility Model Application Publication No. 57-8677 and U.S. Pat. No. 4,415,941.
As disclosed in the specification of the above patent, efforts have been made to increase the rigidity of fixing the guide member and to prevent the generation of moment inside the moving body by driving the center of gravity of the movable part.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a linear guide mechanism for a magnetic disk device that allows a head to move linearly with high accuracy and is less likely to cause read/write errors due to external vibrations or thermal deformation.

[Summary of the invention]

When manufacturing a lJ near guide that performs accurate linear motion, it must be assembled with precision and be resistant to external vibrations.
It is necessary to consider that it is difficult to meander and is difficult to deform due to heat. The present invention is based on the idea of solving these problems as described below.

Here, the access direction is defined as the X-axis, the y-axis is defined in a parallel plane, and two axes are defined perpendicular to this plane.

In the example shown in FIGS. 4 and 5, a pair of rolling wheels 2a is preloaded by a leaf spring 3a. In order to ensure that the pushing direction of the leaf spring 3a is accurately in the y direction, the leaf spring 3a must be manufactured symmetrically with respect to the center line 0, be accurately attached to the carriage 4, and then properly placed between the two rails 10. V
- It is necessary to maintain the positional relationship between the handle 1 and the carriage body when assembling them. If the spring 3a is not symmetrical or if there is an inaccuracy during assembly, a tilt will occur about the X-axis. Further, in the example shown in the M+ diagram, the preload force of the leaf spring 3a is increased to prevent the carriage 4 from moving in the y direction, and the rolling wheel 22 is strongly pressed against the rail 1. Therefore, during assembly, the carriage 4 is assembled between the V-rues 1 while deforming the spring 3a with a large force.
It becomes difficult to adjust the preload direction of the rolling wheel 2a.

In the example shown in FIG. 6, the rail lae is pressed against the rolling wheel 2. In this example, as in the previous example, it is difficult to correctly adjust the positional relationship between the rail 1 and the carriage body during assembly.

In order to avoid this difficulty in precision assembly, improvements are made to the conventional guide based on the following ideas. It uses five rolling wheels to determine the positional relationship between the rail and the carriage body, and one or more rollers apply preload to the rolling wheel. Then, the positional relationship between the carriage body and the 7-ru during assembly is determined by the five rolling wheels, and the other rollers only need to apply pressing force, making it easier to process and install the preload spring. . In this way, the assembly can be performed with high precision.

Next, consider external vibration. In the arrangement of the rolling wheel shown in FIG. 4, the front end side of the carriage 4 vibrates in two directions. When the carriage 4 vibrates in this way, a displacement component around the y-axis occurs, and as shown in FIG. 7, the signal position of the servo surface 13b that controls the position in the track direction,
The signal position of the data 13a shifts by a minute amount δ, causing an error in reading and writing. Therefore, it is desirable to arrange the six rolling wheels 2 supported by the carriage 4 (il-) as shown in FIGS. 8 and 9, and to make the support rigid around the y-axis. It is omitted.

Based on this idea, it seems possible to use a support structure as shown in FIG. 10. However, Figures 9 and 10
The stability against snake action is different from the figure. This is based on the following idea. First, as shown in FIG. 6, the movement in the xz plane, which includes the access direction and is perpendicular to the disk, has a large impact on the reading/writing error. think. When the carriage 4 is displaced in two directions, the displacement tends to return to the original position due to the rigidity of the support member. At the same time, a frictional force is acting on the supporting member of the moving carriage 4 in a direction opposite to the access direction X. With the displacement, @
As shown in FIGS. 11(a) and 11(b), there is a difference in the frictional forces F and -F4 acting on the support members disposed in each region bordering on a plane parallel to the disk. This difference acts as a moment on the carriage 4, but in the support structure shown in FIG. 9, the direction is in the restoring direction as shown in FIG.
The support structure shown in the figure acts in the diverging direction as shown in FIG. 11(b). Therefore, to deal with snake behavior,
In FIG. 10, it is desirable to have a structure as shown in FIG. 9, that is, a support structure in which the direction of the force supporting the carriage 4 acts outward with a plane parallel to the disk as its boundary.

Furthermore, although the linear guide shown in FIG. 12 based on the above idea seems to be good, it is not preferable because it causes read/write errors due to thermal deformation. Reading and writing errors occur for the following reasons.

When the temperature inside the device rises, a gap may be created between the movable part and the rail 10 because the members have different coefficients of thermal expansion. The pace that fixes the guide rail 1 and the carriage 4 are made of aluminum to reduce weight, and the roller wheels 2 are made of aluminum to reduce weight.
Since hardness is required for the rails 1 and 1, they are often made of iron.

In this case, as shown in FIG. 13, a gap is created between the V-rule 1 and the support point of the rolling wheel 2. and preload force 10
The rolling wheel 2 is then pressed against the rail 1, as shown in Fig. 14. At this time, the carriage 4 tilts around the y-axis,
A reading/writing error as shown in FIG. 7 occurs. If a preload force is applied to the position shown in FIG. 15, no inclination around the y-axis occurs, so there is no reading/writing error due to thermal deformation.

Based on the above concept, a linear guide mechanism for a magnetic disk device is realized in which the head is moved in a linear manner with high accuracy and read/write errors are less likely to occur due to external vibrations and thermal deformation.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. One or more guide arms 12 supporting the magnetic head 11 are coupled to the carriage 4 . A voice coil 14 is coupled to the carriage 4. Six roller wheels 2 are arranged on the side of the carriage 4 as support points, five of them have inner rings fixed to the carriage 4, and one roller supports the υ wheel 2.
a is engaged with the carriage 4 via the leaf spring 3.

When assembling, use the five fixed rolling wheels to determine the positional relationship between the carriage body and the rail l, and apply preload to the remaining rolling wheel.

With this structure, it is possible to easily assemble a linear guide that performs accurate linear motion. In addition, it rigidly supports the movement of the carriage 4 in the direction outside the plane of the disk 13, and
The support structure prevents tilting around the axis. Furthermore, since the direction of the supporting force acts outward with respect to a plane parallel to the disk 13, the stability against snake movement is improved. Furthermore, since the preload is applied to the center, as described in the summary of the invention, the inclination of the y-axis rotation due to thermal deformation is small and read/write errors are less likely to occur.

Furthermore, the same effect can be obtained by arranging an arbitrary number of preloaded rolling wheels at arbitrary positions based on the structure shown in FIG.

Alternatively, as shown in FIG. 3, a part or all of the rolling wheel may be engaged with the fixed side 22, and the movable part may be formed as a rolling surface. The same effect can be obtained by this method. Furthermore, there is an effect that the weight of the movable part can be reduced.

Further, in the above embodiments, a leaf spring is used as the preload mechanism, but a coil spring or the attractive force or repulsive force of a magnet may also be used.

〔Effect of the invention〕

According to the present invention, the five fixed support points make it easy to determine the exact positional relationship between the rail and the carriage body during assembly, and since the carriage is rigidly supported around the y-axis, it is free from external vibrations. In addition, since the supporting force acts outward with a plane parallel to the disk as a boundary, the stability against snake movement is improved, which has the effect of allowing the head to move linearly with precision, and furthermore, to ensure proper positioning. Since a preload is applied to the disk, tilting due to thermal deformation is less likely to occur, which has the effect of preventing read/write errors.

[Brief explanation of the drawing]

Fig. 1 is a top view of one embodiment of the present invention, Fig. 2 is a bottom view of Fig. 1, Fig. 3 is a top view of another embodiment of the invention, and Fig. 4 is an example of a general linear guide. 5 is a longitudinal sectional view of FIG. 4, FIG. 6 is a plan view of another example of a general linear guide, FIG. 7 is a diagram explaining the displacement of the carriage in FIG. 6, and FIG. The figure is a plan view showing still another example of a general linear guide, FIG. 9 is a vertical sectional view of FIG. 8, FIG. 10 is a vertical sectional view of still another example of a general linear guide, and FIG. a
) (b) u A diagram showing the direction of frictional force in a general linear guide, Figure 12 is a plan view of yet another example of a general linear guide, and Figure 13 is a diagram showing the support points of the support member in Figure 12. FIGS. 14 and 15 are diagrams showing gaps at the support points of the support member in a partially improved version of FIG. 12. 1...Rail, 2,2a...Rolling car, 3...
Leaf spring, 4... Carriage, 11... Magnetic head,
12... Guide arm, 13... Disc, 14...
...Voice coil, 22...Fixed side. Tomi 1 Zutomi Z Zutomi 3 Zutomi 4 Zu Dormitory 5 Zutomi Δ Zuzu 7 Zuka Fzu inferior De Figure HZa Figure 711 Zuto

Claims (1)

[Claims] a magnetic head for reading and writing recorded signals on a rotating magnetic disk surface; a guide arm having the magnetic head at its tip;
A magnetic disk drive includes a carriage that supports the guide arm, a support means that supports the carriage against the fixed part side and allows the magnetic head to move linearly in the radial direction of the disk, and a motor that drives the carriage in the radial direction of the disk. In the linear guide mechanism, when the carriage is divided into two with a plane passing through the center of gravity of the carriage and parallel to the disk as a boundary, there are four supporting means disposed between the carriage and the fixed part side in one area. As mentioned above, the other region has two or more support points, and these six or more support points are two or more on each of three cutting planes that are approximately equally spaced and perpendicular to the direction of movement of the carriage. The direction of the supporting force applied to the carriage through the support member is outward from a plane passing through the center of gravity of the carriage and parallel to the disk, and the support member having the five support points Rigidly fixed to the carriage or fixed part side,
A support member having one or more support points is elastically engaged with the carriage or fixed part side, and further supports the carriage in a plane parallel to the disc and in a plane perpendicular to the disc and including a straight line in the direction of movement of the carriage. Divided into four areas, the areas on the same side parallel to the disk are called the first and second areas, and the areas on the opposite side are called the third and fourth areas.
When referred to as a region, the area above the central cut plane among the three cross sections,
One rigidly engaged support point is arranged in the first region, one or more elastically engaged support points are arranged in the second region, and each of the other two cutting planes is One support point rigidly engaged with the third region on the cut surface,
A linear guide mechanism for a magnetic disk device, characterized in that one support point is also arranged in the fourth region and rigidly engaged with the fourth region.