JP4034050B2 - Manufacturing method of swing arm base material with support arm for magnetic disk - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a technique for manufacturing a swing arm substrate with a support arm for a two-arm type magnetic disk.
[0002]
[Prior art]
FIG. 4 is a longitudinal sectional view showing a state before assembly of a conventional two-arm type swing arm base material for a magnetic disk. The swing arm base material 1 is composed of a separate one-side arm piece 2 and other parts. The side arm piece 3 and the hollow cylinder 4 are composed of three members.
[0003]
Among these, each of the one-side arm piece 2 and the other-side arm piece 3 has large-diameter holes 2a and 3a that can be combined with the hollow cylinder 4 side by pressing aluminum plate material. The small-diameter hole portions 2b and 3b for attaching the gimbal are provided on the one side portion side on the other side portion side, and a predetermined shape is provided.
[0004]
Further, the hollow cylinder 4 has a bearing metal hole 5 in its axial direction by cutting an aluminum bar, and the large-diameter hole portion 2a on the both end surfaces 4a and 4b side in the axial direction. It is formed with cylindrical protrusions 6 and 7 having an outer diameter substantially the same as the inner diameter of 3a.
[0005]
The one-side arm piece 2 is hollowed through the large-diameter hole 2a, for example, on the cylindrical protrusion 6 positioned on the upper side of the hollow cylinder 4, and the other-side arm piece 3 is hollow through the large-diameter hole 3a. By combining with the cylindrical projections 7 located on the lower side of the cylindrical body 4, the two-arm type swing arm base material 1 shown in FIG. 5 is assembled.
[0006]
[Problems to be solved by the invention]
However, in the case of the conventional method described above, not only an expensive machine tool for cutting is required for accuracy, but also a movable coil is integrally held through a resin molding part separately prepared. However, there is a disadvantage that it is necessary to attach the swing arm base 1 to the side.
[0007]
The present invention has been made in view of the above-described problems of the conventional method, and can not only make cutting using an expensive machine tool for cutting work unnecessary, but also a support arm part for holding a movable coil. It is an object of the present invention to provide a method for manufacturing a swing arm base material with a support arm portion for a two-arm type magnetic disk that can be simultaneously formed and contribute to cost reduction effectively.
[0008]
[Means for Solving the Problems]
The present invention has been made to achieve the above object, and the present invention (a method of manufacturing a swing arm base material with a supporting arm) is a longitudinal direction of a plate-like arm piece portion having an appropriate planar shape. Near one end, a bearing portion that is formed integrally with the arm piece portion with an outer diameter smaller than the width of the arm piece portion is integrally suspended, and includes the arm piece portion side in the axial direction. A pair of arm metal pieces having bearing metal holes penetrated, and an intervening metal piece disposed between the arm metal pieces by extending a pair of supporting arm portions for holding the movable coil to the base portion. Each of the bearing portions is provided with a small-diameter insertion portion provided with a seating height equal to or less than half the plate thickness of the base portion on the open end side, and the small-diameter insertion portion is provided in the base portion. The base portion is provided with a through hole that allows the insertion of the base member. On the other hand, under the arrangement relationship in which the arm pieces face each other and each supporting arm protrudes from the one end side along the length direction, the one small-diameter insertion portion is placed on the one side surface side. The other small-diameter insertion portion is inserted into and fixed to the through hole from the other side surface side, and a method of manufacturing a swing arm substrate with a supporting arm portion in which these arm metal pieces and intervening metal pieces are combined integrally Because
Of the pair of arm metal pieces and intervening metal pieces, at least a pair of arm metal pieces are formed separately by cold forging press processing, and one arm metal piece and the other arm metal piece are each of a small diameter. Under the positional relationship in which the open end face of the insertion part is face-to-face, the base part is inserted into the through hole provided in the base part by positioning from one side and the other side separately. There are structural features in fixing .
[0011]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a longitudinal sectional view showing an example of a swing arm base material for a magnetic disk according to the present invention in a state before assembling, and the entire swing arm base material 11 uses a lightweight metal plate piece such as aluminum. A pair of arm metal pieces 12, 12 which are integrally formed products, and an intervening metal piece 22 formed using a lightweight metal plate piece such as aluminum interposed between the pair of arm metal pieces 12, 12; It is comprised by three members.
[0012]
Among these, each arm metal piece 12 includes a plate-like arm piece portion 13 having an appropriate planar shape, and a column having an outer diameter smaller than the width of the arm piece portion 13 near the one end 13a in the length direction. A bearing portion 15 having a columnar shape having an appropriate height, such as a shape, is integrally suspended. For this reason, the arm piece part 13 located around the bearing part 15 is formed as a flange part 14 protruding from the bearing part 15 side. Note that the planar shape of the pair of arm metal pieces 12 and 12 is basically formed by giving a shape that completely matches each other at the time of assembly and that meets each other. In this case, when the external shape of the pair of arm metal pieces 12 and 12 is different (including an asymmetrical shape), a mold is prepared separately corresponding to the specific shape of each arm metal piece 12. In addition, by integrally molding each of them, it is possible to manufacture with high accuracy. Further, when the pair of arm metal pieces 12 and 12 have the same outer shape in which the pair of arm metal pieces 12 and 12 are symmetrical with each other, they can be manufactured using the same mold.
[0013]
Each arm metal piece 12 is formed with a bearing metal hole 18 having an appropriate inner diameter that is penetrated in the axial direction of the bearing portion 15 including the arm piece portion 13 side.
[0014]
Moreover, the bearing portion 15 provided in each arm metal piece 12 has a small-diameter insertion portion 17 connected to the open end side through a step end surface 16 so that the thickness t ₁ of the base portion 23 of the intervening metal piece 22 to be described later. It is formed having a half or less of the sitting height _{t 2.}
[0015]
By forming the small-diameter insertion portion 17 of the bearing portion 15 and the base portion 23 based on the above dimensional relationship, the open end surface 17a of one small-diameter insertion portion 17 is formed in the through hole 26 of the base portion 23 after assembly. and an open end face 17a of the other small-diameter insertion portion 17 or is brought into close contact with each other, it can be interposed a gap t ₃ therebetween.
[0016]
Therefore, the dimensional accuracy of the sitting height t ₂ of the small-diameter insertion portion 17, it is possible to reliably absorbed in the through-hole 26, it can be assumed that the assembly accuracy was better. In addition, the code | symbol 19 in a figure shows the through-hole drilled near the other end 13b of the arm piece part 13 in order to attach a gimbal.
[0017]
On the other hand, the intervening metal piece 22 has a substantially square shape and is disposed between the bearing portions 15 and 15 of the pair of arm metal pieces 12 and 12 and the base portion 23 to hold the movable coil 31. And a pair of support arms 25, 25 extending in a bifurcated manner in the same direction from the side of the one side 24, and the plane shape is substantially Y-shaped as shown in FIG. ing. In this case, the width of the base portion 23 is preferably formed so as to be substantially the same as the width of the arm piece portion 13, but may be formed to be slightly narrower if necessary.
[0018]
The intervening metal piece 22 includes a through hole 26 formed in the base portion 23 so that the small diameter insertion portion 17 provided in the bearing portion 15 of the arm metal piece 12 can be freely inserted. In this case, the through-hole 26 can be formed so that its diameter is slightly smaller than the outer diameter of the small-diameter insertion portion 17, or substantially the same or slightly larger.
[0019]
In addition, the pair of support arm portions 25, 25 may have a shape corresponding to the specific size of the movable coil 31 and the outer peripheral shape thereof, and the length of the pair of support arm portions 25, 25 only needs to satisfy these conditions. The sheath extending direction can be appropriately selected and formed as desired.
[0020]
Next, the manufacturing method of the swing arm base material with a supporting arm part according to the second invention will be described in detail below together with the description of the operation of the swing arm base material 11 shown in FIG. 1 which is an example of the first invention.
[0021]
That is, of the pair of arm metal pieces 12 and 12 and the intervening metal piece 22 constituting the swing arm base material 11, at least the pair of arm metal pieces 12 and 12 is cold against a lightweight metal plate piece such as aluminum. By performing forging press processing, it is integrally formed with high precision and formed separately under a state where excellent strength is imparted. The intervening metal piece 22 can be formed by cold forging press processing or can be formed by normal press processing.
[0022]
Thus, the pair of arm metal pieces 12 and 12 has the intervening metal piece 22 interposed therebetween as shown in FIG. 1, and the open end surface 17a of the bearing portion 15 of one arm metal piece 12 and the other arm metal piece 12 The bearing member 15 is disposed vertically with a positional relationship in which the open end surface 17a of the bearing portion 15 is confronted with each other.
[0023]
Thereafter, the small-diameter insertion portion 17 of the bearing portion 15 included in the one arm metal piece 12 is inserted into the through hole 26 from the upper surface side of the base portion 23 to the small-diameter insertion portion 17 of the bearing portion 15 included in the other arm metal piece 12. Are respectively inserted into the through holes 26 from the lower surface side of the base portion 23, and are integrally fixed and combined.
[0024]
In this case, the pair of arm metal pieces 12 and 12 and the intervening metal piece 22 face each other, and each support arm portion 25 has a length from the one end 13a side of the arm piece portion 13 to the length thereof. After arranging so as to be in a positional relationship protruding along the direction, the whole is integrally combined by appropriate fixing means. In addition, as a fixing means in this case, an appropriate welding technique such as a YAG laser welding can be adopted in addition to press-fitting and bonding and fixing using an appropriate adhesive.
[0025]
Moreover, if you have formed a small-diameter insertion portion 17 of the bearing portion 15 of each arm metal piece 12 is provided as a sitting height t ₂ of less than 1/2 of the thickness t ₁ of the base portion 23 of the intermediate metal strip 22, FIG. 2, when each small-diameter insertion portion 17 is inserted into the through hole 26, each step end face 16 is brought into contact with the base portion 23 side, and a gap t ₃ is formed between the open end faces 17 a and 17 a. It can be formed without fail.
[0026]
Accordingly, the dimensional accuracy of the sitting height t ₂ of the small-diameter insertion portion 17, since it is possible to reliably absorbed by the through hole 26 can be made to the assembly accuracy was better.
[0027]
The pair of arm metal pieces 12 and 12 is basically formed by giving a shape that is completely coincident with each other at the time of assembly. In this case, when the external shape of the pair of arm metal pieces 12 and 12 is different (including an asymmetrical shape), a mold is prepared separately corresponding to the specific shape of each arm metal piece 12. In addition, by integrally molding each of them, it is possible to manufacture with high accuracy. Further, when the pair of arm metal pieces 12 and 12 have the same outer shape in which the pair of arm metal pieces 12 and 12 are symmetrical with each other, they can be manufactured using the same mold.
[0028]
Moreover, since both of the pair of arm metal pieces 12 and 12 are manufactured under the same construction method (cold forging press processing), the bearing metal hole 18 formed between the small diameter insertion portions 17 and 17 is formed. Concentricity can also be ensured with higher accuracy.
[0029]
Further, the swing arm base material 11 formed by integrating the pair of arm metal pieces 12 and 12 and the intervening metal piece 22 includes the pair of support arm portions 25 and 25. On the other hand, the movable coil 31 can be easily attached by bonding and fixing the movable coil 31 via an adhesive or by integrally molding the support arm portions 25 and 25 and the movable coil 31 with resin.
[0030]
As mentioned above, although this invention was demonstrated based on the example of illustration, the specific content of this invention is not limited to the said description. For example, the cross-sectional shape of each bearing portion 15 may be a cylindrical shape or a polygonal shape such as a rectangular tube shape, and the seating height of each bearing portion 15 is appropriately determined as desired. be able to. Further, the outer diameter of the bearing portion 15 can be matched with the width of the arm piece portion 13.
[0031]
【The invention's effect】
As described above, according to the present invention, a pair of arm metal pieces and an intervening metal, which are integrally formed with each other with high precision, independently of each other, without cutting the swing arm base with a support arm for a two-arm type magnetic disk. Therefore, it is possible to eliminate the troublesome work of assembling while adjusting the accuracy, thereby effectively contributing to the reduction of the product cost.
[0032]
Moreover, since the small diameter insertion part of the bearing part with which each arm metal piece is provided is made into 1/2 or less of the board | substrate thickness of the base | substrate part in an interposition metal piece, the assembly precision can be made more excellent.
[0033]
In addition, since the pair of arm metal pieces is basically formed by giving a shape that is completely coincident with each other at the time of assembly, and has the same outer shape that is symmetrical to each other. In some cases, the same mold can be used. Therefore, the member cost can be reduced as compared with the case where the outer shape of the pair of arm metal pieces is different (including the asymmetric shape). Furthermore, since both of the pair of arm metal pieces are manufactured under the same construction method, the concentricity of the bearing metal hole formed between the small-diameter insertion portions should be ensured with higher accuracy. Can do.
[0034]
Furthermore, since the swing arm base has a pair of support arms, the movable coil is bonded and fixed to the support arms via an adhesive, or the support arm and the movable coil are integrally molded with resin. For example, the moving coil can be easily attached.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a state before assembly of an example of a swing arm base with a support arm for a magnetic disk according to the present invention.
FIG. 2 is a longitudinal sectional view showing an example of a swing arm base material with a support arm portion for a magnetic disk according to the present invention in a state after assembly.
FIG. 3 is a plan view showing an example of intervening metal pieces constituting the present invention.
FIG. 4 is a longitudinal sectional view showing a state before assembly of a configuration example of a conventional two-arm type magnetic disk swing arm base material.
5 is a longitudinal sectional view showing a state after assembly of the conventional example of FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Swing arm base material 2 One side arm piece 3 Other side arm pieces 2a, 3a Large diameter hole part 2b, 3b Small diameter hole part 4 Hollow cylinder body 4a, 4b End surface 5 Bearing metal hole 6, 7 Cylindrical protrusion part 11 Swing arm Base material 12 Arm metal piece 13 Arm piece portion 13a One end 13b The other end 14 The flange portion 15 The bearing portion 16 The step end surface 17 The small diameter insertion portion 17a The open end surface 18 The bearing metal hole 19 The through hole 22 The intervening metal piece 23 The base portion 24 One side 25 Support arm 26 Through hole 31 Moving coil

Claims (1)

A bearing portion formed integrally with the arm piece portion by providing an outer diameter smaller than the width of the arm piece portion near one end in the length direction of the plate-like arm piece portion having an appropriate planar shape is integrated. A pair of arm metal pieces each having a bearing metal hole penetrating in the axial direction including the arm piece part side, and a pair of supporting arm parts for holding the movable coil as the base part. Each of the bearing portions has a seat height of ½ or less of the plate thickness of the base portion on the open end side of each of the bearing portions. The provided small-diameter insertion portion is provided, and the base portion is provided with a through-hole through which the small-diameter insertion portion can be freely inserted. The arm pieces face each other with respect to the base portion. Arrangement relationship that arm part protrudes along the length direction from the one end side Originally, the one small-diameter insertion portion is inserted and fixed into the through hole from one side surface of the other and the other small-diameter insertion portion from the other side surface, and the arm metal piece and the interposition metal piece are integrated. A method of manufacturing a swing arm base material with a support arm part for magnetic disk,
Of the pair of arm metal pieces and the intervening metal pieces, at least a pair of arm metal pieces are formed separately by cold forging press processing, and one arm metal piece and the other arm metal piece are inserted with a small diameter respectively. Under the positional relationship that the open end face of the part meets each other, the base part is positioned and inserted into the through hole provided in the base part separately from both sides of the one side and the other side, and the whole is fixed integrally. A method for producing a swing arm base material with a support arm portion for a magnetic disk.

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