JPS6334116Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an impedance roller, and an object thereof is to provide an impedance roller that is easy to manufacture and can be manufactured at low cost.

Impedance rollers, which are used in tape recorders and the like and are attached to the tape to remove fluctuation components of tape running, are generally made of metal in order to increase the moment of inertia. Figure 1 shows an example of a conventional impedance roller.
It has a structure in which polyacetal bearings 2 are press-fitted into the center of a substantially cylindrical stainless steel main body 1.

In the case of this type of metal impedance roller 3, the outer peripheral surface of the main body 1 (the surface attached to the tape)
As is well known, precision finishing must be applied,
Since it is a metal surface, it has the disadvantage that it is relatively time-consuming to finish it, and since a process of press-fitting the bearings 2, 2 is required, it also has the disadvantage that it takes time to finish the press-fitting surface and press-fitting.
This has the drawback of increasing manufacturing costs.

The present invention eliminates the above-mentioned drawbacks, and an embodiment thereof will be described below with reference to the drawings.

FIG. 2 is a longitudinal sectional view of an embodiment of the impedance roller according to the present invention.

Reference numeral 4 denotes a main body made of abrasion-resistant synthetic resin, and has a cylindrical outer shape. A bearing portion 4a is integrally molded inside this main body 4. Since the main body 4 and the bearing portion 4a are integrated, there is no need for press fitting as in the conventional case, and manufacturing costs can be reduced.
The outer peripheral part 4b of the main body 4 and the bearing part 4a are connected by an end part 4c, and a circumferential groove 4d is formed therein. On the other hand, a flange portion 4 is provided on the lower side of the bearing portion 4a.
e is formed, and a bent portion 4f projecting inward is integrally formed on the other end surface side of the outer peripheral portion 4b.

A cavity is formed in the main body 4, and a weight 5 made of zinc die-casting is embedded in this cavity. The weight 5 has a reduced diameter part 5a and a large diameter part 5b on its cylindrical inner periphery. The reduced diameter portion 5a of the weight 5 is fitted in contact with the flange portion 4e, and the end surface of the large diameter portion 5b is in contact with the bent portion 4f. Furthermore, a bearing part 4a is fitted into the inner periphery of the reduced diameter part 5a, and the upper surface and outer periphery of the weight 5 are covered by an end surface 4c and an outer periphery 4b.
Therefore, the weight 5 is in contact with the bent portion 4f, the flange 4e, and the end face 4c in the axial direction, and in the radial direction with the bearing portion 4a on the inner periphery and the outer periphery 4b on the outer periphery. It is maintained in a stable condition. Further, since the flange portion 4e is in contact with the end surface of the reduced diameter portion 5a which is located inside the end surface of the large diameter portion 5b, there is a gap between the flange portion 4e of the main body 4 and the bent portion 4f. The surrounding surface is exposed.

The manufacturing procedure of the impedance roller 6 of this embodiment will be explained below.

First, the weight 5 is manufactured using inexpensive zinc die casting. Next, the weight 5 is positioned in the mold, and the main body 4 is formed on the outer surface of the weight 5 by injection molding. This results in
Impedance roller 6 is obtained, but after this,
The outer circumferential surface of the outer circumferential portion 4b of the main body 4 and the inner circumferential surface of the bearing portion 4a are cut to a predetermined precision.

In this way, when the weight 5 is integrally molded with the main body 4, the positioning part of the molding die (not shown) is fitted to the inner circumferential surface of the large diameter part 5b of the weight 5, and the weight 5 and the Positioning is performed with a central core member (not shown) for forming a bearing portion 4a penetrating through the shaft 5.

Also, when cutting the main body 4, the large diameter portion 5 of the weight 5 is inserted into the claw portion of the chuck (not shown) that opens in the outer circumferential direction.
b The impedance roller 6 is brought into contact with the inner peripheral surface.
hold. In addition, since the inner periphery of the exposed large diameter portion 5b of the weight 5 is chucked, it is possible to achieve coaxiality between the weight 5 and the main body 4, which causes more distortion in the main body 4 than when chucking the main body 4 made of synthetic resin. It's hard to do. In addition, since both the bearing part 4a and the outer peripheral part 4b are made of synthetic resin, the finishing process is easier than when cutting a metal surface, and since the bearing part 4a is formed at the same time during injection molding. , which eliminates the hassle of press-fitting as required in the past. This has the advantage of lower manufacturing costs.

Furthermore, since the structure has a zinc die-cast weight embedded in it, the moment of inertia is almost the same as that of the conventional model. Furthermore, in the past, the bearing was press-fitted into the main body, and there was some eccentricity in the bearing, which caused variations in each product, but in this embodiment, the bearing part 4a is attached to the peripheral part 4b during injection molding. Because they are formed at the same time, the position of the bearing part 4a is determined only by the precision of the mold (generally high precision), so there is no variation in the eccentricity of the bearing part due to manufacturing, and Since cutting of the part 4a is easy,
There is an advantage that the degree of eccentricity can be suppressed to a small extent and a good impedance roller can be provided.

As mentioned above, the impedance roller of the present invention is integrally molded with a metal weight embedded inside the impedance roller body made of synthetic resin.
The weight has a cylindrical inner periphery having a reduced diameter part and a large diameter part, and the impedance roller body has a bearing part that fits on the inner periphery of the reduced diameter part of the weight, and a bearing part that is continuous with the bearing part and has a large diameter part. an outer periphery that covers the outer periphery of the weight; a bent part that abuts the end face of the large diameter part; and a flange part that protrudes radially from the bearing part and abuts the end face of the reduced diameter part inside the end face of the large diameter part. The positioning part of the molding die is fitted to the inner periphery of the large diameter part of the weight exposed between the bent part and the flange part of the main body to form the bearing part of the weight and the main body. The position relative to the center core member of the mold can be determined with high precision, and the claw part of the chuck can be brought into contact with the inner periphery of the large diameter part of the weight during cutting, so that the main body can be processed without being distorted. Furthermore, the bearing part can be formed at the same time as the outer circumferential part during injection molding, eliminating the need to press-fit a separate bearing.Also, since the outer circumferential part and the bearing part are made of synthetic resin, cutting is easy. Then,
Therefore, manufacturing is simplified and manufacturing costs can be reduced, and furthermore, since the bearing part is integrally molded,
The eccentricity of the bearing part is slight, and it has the advantage that there is no variation from product to product.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an example of a conventional impedance roller, and FIG. 2 is a longitudinal sectional view of an embodiment of the impedance roller according to the present invention. 1, 4...Main body, 2...Bearing, 3, 6...Impedance roller, 4a...Bearing portion, 4b...Outer circumferential portion, 4c...End portion, 4d...Peripheral groove, 4e...Flange portion, 4f... bending part, 5... weight, 5a...
Reduced diameter part, 5b...large diameter part.

Claims (1)

[Scope of utility model registration request] A metal weight is integrally molded to be embedded inside the impedance roller body made of synthetic resin, and the weight has a reduced diameter part and a large diameter part on the inner periphery of a cylindrical shape. a bearing part that fits into the inner periphery of the reduced diameter part, an outer periphery part that is continuous with the bearing part and covers the outer periphery of the weight, a bent part that comes into contact with the end surface of the large diameter part, and a radial direction from the bearing part. An impedance roller comprising: a flange portion that protrudes from the end surface of the large diameter portion and abuts the end surface of the reduced diameter portion inside the end surface of the large diameter portion.