JPH0731427Y2 - Magnetic disk cartridge - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a magnetic disk cartridge for rotatably storing a disk-shaped disk such as a magnetic disk.

(Prior Art) In general, a magnetic disk cartridge includes, as shown in FIG. 2, a magnetic disk 1, a hub 2 fixed to the central portion of the disk 1, and a liner 3 made of a non-woven fabric or the like for cleaning the disk 1. But the head hole 4 and the hub hole 5
It is arranged in a resin-made exterior case 6 having a.

The liner 3 has a central hole 3a and a cutout 3b so that the liner 3 does not come into contact with a magnetic head (not shown) on the recording / reproducing apparatus side that contacts the internal disk 1 through the hub 2 and the head hole 4.
Is formed in a substantially C shape. This liner 3 has its peripheral edge portions welded to the inner surfaces of the upper half and the lower half of the case 6 by ultrasonic welding. In this ultrasonic welding, as shown in FIG. 2, in the predetermined width region 3c of the peripheral portion of the liner 3, the welded portions 7 are inclined in a certain direction so as to be parallel to each other, and are formed at equal intervals. Since the pattern welding is easy to make by ultrasonic welding,
Many were taken.

However, in the welding of such a pattern, the welding portion 7
Is not constant in length, and a short portion 7a and a long portion 7b are formed. As the characteristics of ultrasonic welding, when the length of the welded portion is short, the welding energy is concentrated and reliable welding is possible, but the longer the length, the more energy tends to diffuse, and the lower the degree of welding. . Therefore, the welding of the long portion 7b is likely to be incomplete, so that the liner 3 is likely to be peeled off or lifted from the portion of the long portion 7b, which causes fluctuations in the rotational torque of the disk 1 and adversely affects recording / reproduction. It was the cause. In other words, this welding pattern corresponds to each welding portion 7
Has a disadvantage that the welding energy is unbalanced and the welding failure is likely to occur.

In order to solve this problem, an improvement in the welding pattern has been attempted. For example, as shown in JP-A-61-115286 shown in FIG. 3, the welding portion 7 is irradiated with radiation in a predetermined width region of the peripheral portion of the liner 3. A method is considered in which the liner 3 is ultrasonically welded by a welding pattern in which each welded portion 7 is formed into a substantially uniform shape and has a substantially equal length.

However, this method has a disadvantage that it is difficult to manufacture a die used for welding and the manufacturing cost is also increased.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a magnetic disk cartridge in which a welding mold can be easily and inexpensively manufactured, and moreover, the entire peripheral edge of the liner is uniformly welded to the inner surface of the outer case.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the magnetic disk cartridge according to the present invention is provided with a large number of lines in which the peripheral edge of the liner and the inner surface of the outer case are welded substantially in parallel and of substantially equal length. It is characterized in that the welded portion formed in the linear welded portion and formed in the tangential direction of the peripheral edge portion of the liner constitutes a long welded portion having a divided shape of substantially the same length as the other welded portions.

The linear welded portions having substantially the same length are substantially parallel to each other, but when the term "parallel" used herein means the same straight line, that is, a plurality of linear welded portions are arranged on the same straight line at a predetermined interval. Including the case

(Effects of the Invention) In the magnetic disk cartridge according to the present invention, a liner ultrasonically welded to the inner surface of the outer case is welded by a plurality of linear welded portions having substantially equal length and substantially parallel to each other at the peripheral edge of the liner. The welded portion formed in the tangential direction of the peripheral portion,
A long welded portion having a divided shape having a length substantially equal to that of the other welded portions is formed.

Therefore, each welded portion is formed in the tangential direction of the peripheral edge of the liner and has substantially the same length without any length. As a result, the degree of diffusion and concentration of ultrasonic energy during welding of all welded portions is high. As a result, it is possible to uniformly ultrasonically weld the entire peripheral portion. Therefore, the problem that the liner peripheral edge is not welded uniformly and the liner is peeled off from the insufficient welded portion is solved.

Further, the pattern of the welded portion is not radial but substantially parallel, and therefore, there is no problem that it is difficult to center the die during the fabrication of the die as in the case of radial, and the die can be easily and inexpensively produced.

(Embodiment) An embodiment of the magnetic disk cartridge according to the present invention will be described in detail below with reference to FIG. The same numbers are used for members having the same functions as the members described in FIGS. 2 and 3 which are conventional examples.

FIG. 1 is a plan view showing the inner surface of the lower half 6a of the outer case of the magnetic disk cartridge. In the magnetic disk cartridge, magnetic layers are formed on both sides of a disk-shaped base made of a flexible polyester sheet or the like, and magnetic recording / reproduction is performed on the magnetic layer by a magnetic head while being rotated at a high speed (Fig. (Not shown) is stored.

The magnetic disk cartridge comprises the disk and a resin outer case 6 for housing the disk.
Is formed by joining a lower half 6a having a circular hub hole 5 and a head hole 4 and an upper half (not shown) having substantially the same shape as the lower half 6a.
A non-woven liner 3 having a shape substantially corresponding to the disk is welded to the inner surface of the above, that is, the inner surfaces of the upper and lower halves. This non-woven fabric liner 3 is made of non-woven fabric of thermoplastic synthetic resin fiber such as rayon, polypropylene, polyester, etc. so as to contact the upper and lower surfaces of the disc for cleaning action, and has a circular shape substantially corresponding to the disc. Hub hole 5 so that it does not come into contact with the hub fixed to the hub and the magnetic head on the recording / reproducing device side.
And the central hole 3a and the notch 3b at corresponding positions of the head hole 4.
Is formed into a substantially C shape.

The nonwoven fabric liner 3 is welded to the inner surface of the outer case 6 by ultrasonic welding at the peripheral edge thereof. Since the welding of the liner 3 is the same for the upper half and the lower half, only the case of the lower half 6a shown in FIG. 1 will be described.

The welding of the liner 3 to the inner surface of the lower half 6a is carried out at a large number of linear welded portions 7 that are substantially parallel and have substantially equal lengths at the peripheral edge of the liner 3, as shown in FIG.

A welding die for obtaining such a welding pattern is, for example, ground a large number of parallel linear grooves in a region corresponding to a liner peripheral portion of the die, and for a portion where the grooves have a predetermined length or more, It can be manufactured by grinding the grooves of the part at right angles at the predetermined length intervals, and therefore the mold manufacturing is easy.

Long welded portion 7b formed because the welded portions are linearly arranged in the tangential direction of the annular region that is the peripheral edge of the liner 3.
Also, the other welded portions are cut to have substantially the same length, and a plurality of substantially equal length welded portions 7 are arranged on a straight line at a predetermined interval.

In the above-described embodiment, since the entire peripheral portion of the liner 3 and the inner surface of the outer case 6 are welded by the welded portion 7 having a substantially equal length suitable for ultrasonic welding, the welded portions are uniform and reliable. Welding can be performed. Moreover, since each welded portion is not a radial shape but a parallel line shape, the die can be easily and inexpensively manufactured.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view showing the inside of an embodiment of a magnetic disk cartridge according to the present invention, FIG. 2 is a plan view showing the inside of a conventional magnetic disk cartridge, and FIG. It is a top view which shows the inside of the conventional magnetic disc cartridge different from the figure. 1 ... Disc, 3 ... Liner 6 ... Resin case, 7 ... Welding part

Claims (1)

[Scope of utility model registration request] 1. A magnetic disk cartridge comprising a resin outer case for accommodating a disk and a liner having a peripheral edge welded to the inner surface of the case by ultrasonic welding, wherein the liner peripheral edge and the inner surface of the outer case. Welding is performed in a large number of linear welding portions that are substantially parallel and substantially equal in length, and the welding portion formed in the tangential direction of the liner peripheral edge portion is
A magnetic disk cartridge, characterized in that a long welded portion of a divided shape having a length substantially equal to that of other welded portions is formed.