JPH0358356A - Oscillation type head positioning mechanism - Google Patents

Abstract

PURPOSE:To exactly position the head by providing a mounting member which pulls and fixes the rear part side of an arm in the boundary part direction of the 1st and 2nd reference planes of an arm supporting block. CONSTITUTION:The mounting member 20 pulls and fixes the rear part side 2h of the arm 2 in the boundary part direction of the 1st reference plane 8a and 2nd reference plane 8b of the arm supporting block 6. A bolt 20a is so screwed to the hypotenuse 2d formed in the boundary part between the side edge 2a and rear end edge 2b of the arm 2 so as to form an equal angle with the reference planes 2a, 2b and projects to the rear surface of the supporting block 6 via a hole 10c provided in the supporting block 6. After a washer 20c is passed onto this bolt 20a, the nut 20b is screwed and tightened to pull and fix the arm 2. The side edge 2a and rear end edge 2b of the arm 2 come respectively into contact with the reference planes 8a and 8b and the arm is exactly positioned and regulated in correspondence to these reference planes 8a and 8b.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a swing type head positioning mechanism, and particularly to a mounting structure for an arm having a magnetic head.

[Prior Art] Generally, in a magnetic disk drive, mechanisms for positioning a magnetic head at a predetermined track position include a linear head positioning mechanism and a swinging head positioning mechanism. Conventionally used linear head positioning mechanisms have a large number of parts that make up the guide section, are complex, and require a long operating range, so there is a limit to miniaturization. On the other hand, the swing type head positioning mechanism has a simple mechanism and is advantageous in terms of size and weight reduction.

However, the above-mentioned swing type head positioning device has an arm made of a long-sided plate material, and this arm has a magnetic head fixed to the front side, a rotating shaft fitted to the rear side, and Since a plurality of these are stacked and fastened together with a plurality of lamination bolts to form an arm portion as a whole, the arm portion must be completely disassembled when replacing any arm. Furthermore, since high machining accuracy is required for each arm and machining tolerances are accumulated, it is difficult to position the arms with high accuracy. In addition, since the arm section as a swinging section is composed of individual parts, it is difficult to increase the rigidity.Furthermore, this arm section is composed of a laminated body, and the material linear expansion coefficients of the arm and laminated bolt are different. Therefore, there is a problem in that temperature changes in the disk device cause misalignment of the laminated surfaces between the arms, and as a result, relative positional misalignment between the servo magnetic head and each data magnetic head tends to occur.

Therefore, there is a swing type head positioning device as described in Japanese Patent Application Laid-Open No. 63-127474. This swing type head positioning device will be explained using FIGS. 4 to 7. In the figure, 1 is a magnetic head, 2 is an arm, 4 is a rotating shaft, 5 is a coil, and 6 is an arm support block.

The above-mentioned arm 2 is made of a long side-shaped plate material with a central part cut out in several places, and a magnetic head l is fixed to the front part side, and one side edge 2a and rear end edge 2b are mutually connected in the rear part 2h. It is shaped to give off a right angle. The arm support block 6 is attached to the rotating shaft 4, and has a first reference surface 8a extending substantially in the radial direction of the rotation @4, and a second reference surface 8b extending substantially perpendicular to the first working reference surface 8a. is formed, and constitutes a substantially V-shaped arm attachment portion 8. As the side edge 2a and rear end R2b of the arm 2 abut against the first reference surface 8a and the second reference surface 8b, respectively, the arm 2 is accurately positioned and regulated in correspondence with these reference surfaces 8a and 8b. In this case, the fitting piece 2m has a part of the side edge 2a protruding in the direction of the first reference surface 8a, and the rear edge 2b
The fitting piece 2n formed to protrude rearward from the groove 9a and the second groove 9a formed on the tip side of the L-th reference surface 8a, respectively.
It is fitted into a groove 9b formed on the tip side of the reference surface 8b.

The reference grooves 9a and 9b are formed to be about 10 to 20 μm wider than the thickness of the fitting pieces 2m and 2n. Reference numerals 7a and 7b are mounting screws, and after positioning and regulating the arm 2 to the arm support block 6 as described above, the mounting screws 7a are inserted into the side of the arm 2 from the side wall 6b opposite to the first reference surface 8a through the hole 10a. By screwing into a screw hole (not shown) formed in the edge 2a and screwing the mounting screw 7b into a screw hole (not shown) formed in the fitting piece 2n, the side edge 2a can be fixed. The arm 2 is fixed to the arm support block 6 so as to be energized by the lth reference plane 8a{Ijl. Note that the arm 2 is made of a material with a linear expansion coefficient equivalent to that of the magnetic disk.

Next, the operation of this swing type head positioning mechanism will be explained. Feedback control is performed using servo information stored on the servo surface of a magnetic disk (not shown), and a necessary current is applied to the coil 5. The arm portion 2c swings due to the electromagnetic force generated from the coil 5, and the magnetic head 1
moves onto a predetermined track on the magnetic disk.

[Problems to be Solved by the Invention] Since the conventional swing type head positioning mechanism is constructed as described above, it is necessary to assemble each arm 2 while making contact with the second reference surface 8b, and the assembly is difficult. It's troublesome and @ edge 2
b was not energized in the direction of the second reference surface 8b, and a minute gap was created between the rear edge 2b and the second reference surface 8b due to dimensional errors in the mounting screws 7a, 7b, hole 10a, etc. In this case, the positioning of the arm 2 in the radial direction of the rotation axis 4 cannot be performed accurately and reliably, and the screw holes of each arm 2, the mounting screws 7a and 7b, and the hole 10a of the arm support block 6 cannot be formed with high precision. In addition to this, there were problems such as requiring a plurality of mounting screws 7a, 7b, etc., and requiring a large number of parts, making it impossible to reduce weight and size.

This invention was made to solve the above-mentioned problems, and it is a swinging device that facilitates assembly, allows accurate positioning, and reduces the number of parts to reduce weight and size. The purpose is to obtain a mold head positioning mechanism.

[Means for Solving the Problems] A swing type head positioning mechanism according to the present invention includes an arm support block that is pivotally attached to a rotating shaft and rotated by electromagnetic force acting on a coil, and a structure formed on the arm support block. an arm mounting portion having a V-shaped notch, the arm mounting portion having a V-shaped notch, and having a first reference surface extending substantially in the radial direction of the rotating shaft and a second reference surface extending substantially perpendicularly to the first reference surface; a plate-shaped arm having a magnetic head on the arm support block, a plate-shaped arm having a rear side edge in contact with the first reference plane and a rear end edge in contact with the second reference plane; The arm support block is provided with a mounting member that pulls and fixes the rear side of the arm in the direction of the boundary with the second reference plane. [Function] The swing type head positioning mechanism of the present invention pulls and fixes the rear side of the arm using a mounting member provided in the direction of the boundary between the first reference plane and the second reference plane in the arm support block. As a result, the side edge of the arm is brought into contact with the first reference surface, and the rear edge of the arm is brought into contact with the second reference surface.

[Embodiment] A swing type head positioning mechanism which is an embodiment of the present invention will be described below with reference to FIGS. 1 to 3. In addition, the fourth
Components that are the same as those in FIGS. 7 to 7 are designated by the same reference numerals, and description thereof will be omitted. In the figure, reference numeral 20 denotes a mounting member, which is composed of a bolt 20a, a washer 20b, and a nut 20c. The mounting member 20 includes a boundary portion 8c between the first reference surface 8a and the second reference surface 8b in the arm support block 6.
The bolt 20a is fixed by pulling the rear side 2h of the arm 2 in the direction, and the bolt 20a is attached to the oblique side 2d formed at the boundary between the side edge 2a and the rear edge 2b of the arm 2.
, are screwed so as to be equiangular with the second reference surfaces 2a and 2b, and protrude from the rear surface 6b of the arm support block 6 through a hole 10c provided in the arm support block 6.

After passing the washer 20b through the bolt 20a, tighten the nut 20ctr and pull the arm 2 to fix it. The arm 2 has its side edges 2a and rear edge 2b in contact with a first reference surface 8a and a second reference surface 8b, respectively, and is accurately positioned and regulated in accordance with these reference surfaces 8a and 8b. Further, the rear portion 2h of the arm 2 is fitted into a groove 9 formed in the arm attachment portion 8 consisting of the first reference surface 8a and the second reference surface 8b. This groove 9 is formed to be approximately 10 to 20 μm wider than the thickness of the rear portion 2h of the arm 2. Furthermore, the arm 2 is equipped with a signal amplification IC.
A flexible printed circuit (FPC) 21 is provided.

In the above structure, firstly, since the arms 2 are each independently fixed to the arm support block 6, it is easy to fix and separate any one arm 2.

Second, with respect to the first reference surface 8a and the second reference surface 8b,
Arm 2 produces the effect of a beam.

That is, the rigidity in the swinging direction is increased by the arm 2, and the mechanical rigidity necessary for stable control by the servo mechanism is obtained.

Thirdly, minute displacements of the arm 2 due to thermal stress caused by differences in linear expansion coefficients of the swinging part structure or parts when the temperature of the device itself changes are based on the first and second reference planes 8a and 8b at the bottom of the groove. This occurs in the direction in which the bolts 20a1if6 are attached.

Since the fixed reference surfaces 8a and 8b of the arms 2 are formed in the same shape on the block 6, the minute displacement amount and direction of each arm 2 are substantially the same.

Further, since the magnetic head 1 and the bolt 20a form a constant angle, only a certain portion of the displacement of the arm 2 in the bolt tightening direction in the cosine direction becomes the displacement in the magnetic head mounting direction. As a result, the amount of displacement in the mounting direction of the magnetic head is smaller than the displacement in the bolt tightening direction of arm 2, and since the magnitude of each arm is almost the same as the above minute displacement, as a result, the servo magnetic head and each data magnetic head It becomes possible to suppress the relative positional deviation of.

Also, the fourth bolt 20a is used to attach the arm 2.
Only one bolt is required, and by tightening this bolt 20a, the side edge 2a and rear end edge 2b of the arm 2 are aligned with the first and second reference planes 8a and 8.
b, and the rear part 2h is fitted into the groove 9, so positioning can be performed with high precision and reliability, and the structure is simple, making it possible to reduce the weight and size.

In this embodiment, the bolt 20a is attached to the oblique side 2dL of the arm 2:[. However, the mounting member 20 may be constructed integrally with the arm 2, and the mounting member 20 may be composed of a bolt 20a, a washer 20b, and a nut 20c. It may be constructed using only the mounting screws 2 or hexagonal bolts for screwing.

[Effects of the Invention] As described above, in the swing type head positioning mechanism according to the present invention, the rear side of the arm is pulled in the direction of the boundary between the first reference plane and the second reference plane in the arm support block. Since a fixing member is provided on the arm support block, the rear end of the arm can be biased and positioned on the second reference plane as well as on the first reference plane, and a minute gap is created between the second reference plane and the arm. It is possible to accurately position the rotating shaft in the radial direction without causing any
There is no need to pay special attention to ensure accurate contact with the reference surface, and assembly is easy.
Since the arm can be energized on both the second reference plane, very high processing accuracy is not required, and the holding force provided by both the first and second reference planes prevents the arm from wobbling, reducing the number of parts in the mounting member. There is no need to increase the number of units, and the weight and size can be reduced.

[Brief explanation of drawings]

1 and 2 are a plan view and a side view of a swing type head positioning mechanism which is an embodiment of the present invention, FIG. 3 is a plan view of an arm and an arm support block, and FIGS. 4 to 6 are An external perspective view, a side view, and a plan view of a conventional swing type head positioning mechanism, and FIG. 7 is a sectional view taken along the line AA in FIG. 5. DESCRIPTION OF SYMBOLS 1... Magnetic head, 2... Arm, 4... Rotating shaft, 5... Coil, 6... Arm support block, 8...
...Arm attachment part, 8a, 8b...Reference surface, 9...
・Groove, 2o...Mounting member. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Scope of Claims] An arm support block pivotally connected to a rotation shaft and rotated by electromagnetic force acting on a coil, and a first arm support block formed on the arm support block and extending substantially in the radial direction of the rotation shaft.
A V-shaped notch arm mounting portion consisting of a reference surface and a second reference surface extending substantially perpendicular to the first reference surface; a plate-shaped arm that abuts on a reference surface and whose rear edge abuts on the second reference surface; A swing type head positioning mechanism characterized in that the arm support block is provided with a mounting member that is fixed by pulling the side thereof.