JPH0670460U - Magnetic disk drive - Google Patents

Abstract

(57) [Abstract] [Purpose] To reduce the cost of the device by eliminating the need for cutting the irregularities of the frame. [Constitution] A hub for mounting and driving a magnetic disk on the outer peripheral surface, and a drive magnet fixed on the inner peripheral surface of the hub,
In a magnetic disk drive device including a stator core having a coil wound opposite to the drive magnet and a frame for fixing the stator core, the frame 2 is made of sintered metal, and the surface of the frame 2 is formed. The concavo-convex portions 2d and 2c are composed of non-cut surface.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a magnetic disk drive device.

[0002]

[Prior art]

 Conventionally, a so-called center axis rotation type magnetic disk drive device as shown in FIG. 2 is known. In the figure, reference numeral 1 designates a frame, and a hollow cylindrical bearing holder portion 1b is erected integrally in the central portion. An iron core 3 is fixed to the outer periphery of the bearing holder portion 1b, and a coil 4 is wound around the core 3. Outer rings of the bearings 5 and 5 are fitted and fixed to the inner periphery of the bearing holder portion 1b, and a center shaft 6 is fitted and fixed to the inner rings of the bearings 5 and 5. A hub 7 shaped so as to cover the core 3, the coil 4 and the like is fitted and fixed to an end portion of the central shaft 6, and a magnetic disk (not shown) is provided on the outer peripheral surface of the core 3 on the inner peripheral surface. The ring-shaped drive magnets 8 are mounted at the opposite positions. An insulating paper 11 is attached to the upper surface of the frame 1 under the coil 4 in the drawing, and a flexible substrate (Flexible Print Circuit) 10 extending to the outside of the motor is attached to the lower surface thereof. The flexible substrate 10 is one in which a conductor pattern is formed on a base made of an insulating material, and a cover made of an insulating material is coated on the conductive pattern. As shown in FIGS. 2 and 3, a through hole 1a for drawing out a lead wire (terminal wire) 9 from the coil 4 is formed in the lower portion of the coil 4 of the frame 1, and the lead wire is formed. Reference numeral 9 denotes a conductor pattern portion (solder land portion) exposed from the cover of the flexible substrate 10 through the through hole (not shown) formed in the insulating paper 11, the through hole 1a of the frame 1, and the notch 10a of the flexible substrate 10. Soldered on top 10b. Then, by applying a predetermined drive voltage to the coil 4 from a power supply means (not shown) outside the motor through the conductor pattern of the flexible substrate 10 and the lead wire 9, the hub 7 having the magnetic disk mounted thereon is rotated. Has become.

[0003]

[Problems to be solved by the device]

 However, the above magnetic disk drive device has the following problems. That is, a portion of the lower end surface of the frame 1 to which the flexible substrate 10 is attached is a concave surface 1d, and this concave surface 1d is formed by plastic working by pressing or forging. As shown in the figure, the convex part 1e is generated on the back surface of the press part, so this convex part 1e must be removed by turning, but this cutting is an intermittent cutting, and the cutting tool immediately falls off, and There is a problem that processing is impossible. On the other hand, in the latter case, the forging itself has relatively poor forming dimensional accuracy, and since many harmful stains and the like adhere to the surface, it is necessary to finish the concave surface 1d by turning, but this is also an intermittent cutting. Therefore, as in the former case, almost no machining is possible. Further, in both of them, the bottom surface 1c of the frame 1 has to be cut in order to obtain dimensional accuracy, but there is a problem that the cutting is extremely difficult as described above.

Therefore, an object of the present invention is to provide a low-cost magnetic disk drive device that does not require cutting of the uneven portion.

[0005]

[Means for Solving the Problems]

 In order to achieve the above object, the magnetic disk drive device of the present invention has a hub for mounting and driving a magnetic disk on the outer peripheral surface, a drive magnet fixed on the inner peripheral surface of the hub, and a coil facing the drive magnet. In a magnetic disk drive comprising a wound stator core and a frame for fixing the stator core, the frame is made of sintered metal, and the irregularities on the surface of the frame are not cut. It is characterized by being constructed from a work surface.

[0006]

[Action]

 According to the magnetic disk drive device in such means, the frame formed by sintering has excellent dimensional accuracy, and the surface thereof is almost free from undulations and stains, so that cutting of the uneven portion is unnecessary. Become.

[0007]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of a frame of a magnetic disk drive according to an embodiment of the present invention. Since the other parts other than this frame are exactly the same as the prior art, the description thereof is omitted here. To do. The frame of the magnetic disk drive of this embodiment is different from that of the prior art in that the frame 2 is made of sintered metal.

Here, this sintered metal is obtained by kneading, for example, stainless metal powder with a binder (binder), molding this with a metal mold in the same manner as plastic injection molding, and then applying a temperature of 100 ° C. or higher. It is a product that is sintered and solidified at a high temperature, and has extremely excellent dimensional accuracy compared to products manufactured by processing methods such as forging and casting, and it seems that there is almost no waviness or dirt on its surface. It has become.

Therefore, it is not necessary to cut the concave portion 2d to which the flexible substrate 10 is attached and the bottom surface 2c of the frame, and the device can be made inexpensive. Further, since the cutting time associated with the recesses 2d and 2c can be omitted in this way, it is possible to mass-produce the frame 2. Furthermore, even if the dimensional accuracy is required to be higher than the above, and there is almost no waviness or stain on the surface, it has an effect that it can be easily processed.

Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the above-mentioned embodiments, and various modifications can be made without departing from the gist of the invention. Needless to say, for example, in the above embodiment, only the application example to the concave portion 2d is described, but the same can be applied to the convex portion.

Further, it is also applicable to a type in which the bearing holder portion 1b and the frame are separate bodies.

Furthermore, it is of course applicable to a fixed center axis type magnetic disk drive.

[0013]

[Effect of device]

 As described above, according to the magnetic disk drive device of the present invention, since the frame is formed of sintered metal, the frame formed by sintering has excellent dimensional accuracy, and the surface thereof has a waviness. Since there is almost no dirt, cutting of the uneven portion is unnecessary, and the cost of the device can be reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a frame of a magnetic disk drive according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a magnetic disk drive device showing a conventional technique.

FIG. 3 is a view of FIG. 2 seen from below.

FIG. 4 is a diagram for explaining a problem when the recess of the frame is formed by plastic working by pressing.

[Explanation of symbols]

 2 frame 2d recess

Claims (1)

[Scope of utility model registration request] 1. A hub for mounting and driving a magnetic disk on the outer peripheral surface, a drive magnet fixed to the inner peripheral surface of the hub, a stator core around which a coil facing the drive magnet is wound, In a magnetic disk drive including a frame for fixing a stator core, the frame is made of a sintered metal, and the concavo-convex portion on the surface of the frame is made of a non-cut surface. Magnetic disk drive.