JPH04182959A - Tape guide made of ceramics - Google Patents

Abstract

PURPOSE:To produce a tape guide with high accuracy at a low cost by providing a recessed part having a center axis common to a cylindrical body inside the cylindrical body and specifying the size of the recessed part. CONSTITUTION:This tape guide is made of ceramics, and the recessed part having the center axis common to the cylindrical body is provided inside the cylindrical body. In this case, the tape guide satisfying an expression I is used, where the entire length of the cylindrical body is l0, the outside diameter is d0, the inside diameter is d1, the length of the recessed part in an axial direction is l, and the diameter is (d) as for the size of the recessed part. Then, it will suffice to provide the recessed parts having the diameter of (d), singly or plurally but in case they are plurally provided, it is necessary to set the sum of the length in the respective axial directions to l. Thus, the tape guide is produced with high accuracy at a low cost.

Description

[Detailed description of the invention] "Industrial application field" The present invention relates to a guide for a magnetic tape.

``Prior art'' Traditionally, metal materials have been used as guides for porcelain tapes.In some cases, guides for porcelain tapes made of metal were made integrally with a metal shaft, but in most cases In this case, it was made into a cylindrical shape and then fitted with a metal shaft.

``Problem to be solved by the invention'' However, metal materials have insufficient abrasion resistance, and it is extremely difficult to achieve the goal of long life while maintaining the high precision required for magnetic tape guides. It's difficult. Ceramics, which have excellent wear resistance, are expensive to process.

One of the reasons why ceramic machining is expensive is that diamonds are used for the grinding process. for example,
When the cylindrical body of the metal material used to fit with the metal shaft of the prior art mentioned above is a ceramic cylindrical body, the entire inner diameter surface area of the ceramic cylindrical body must be ground for precise alignment with the metal shaft. Must be. Furthermore, among the costly ceramic grinding processes, processing the inner diameter surface in particular takes the most time, consumes diamonds quickly, and is cost effective.
It is difficult to reduce the

The purpose of the present invention is to provide a highly accurate and fully equipped
To provide a ceramic tape guide that can be manufactured at low cost.

The first means is a cylindrical tape guide that is fitted onto a metal part and whose outer peripheral surface slides on the porcelain tape. A recessed portion with metal is provided inside the cylinder stop, and the size of the recessed portion is determined by the total length 2o of the cylindrical body, the outer diameter do, the inner diameter d1, and the axial length λ of the recessed portion.
, the diameter d is 9, and the formula ta is determined by using a tape guide.

Here, the ceramic includes all known ceramic materials with excellent sliding properties such as zirconia, alumina, silicon nitride, silicon carbide, and sialon.

As for the external fitting method with the metal shaft, any known fitting method such as press fitting, shrink fitting, cold fitting, etc. may be used.

Here, the number of recesses having a diameter d may be one or more, but in the case of a plurality of recesses, it is sufficient if the sum of the lengths in the axial direction of each recess is equal to g.

The fewer the number of recesses, the fewer the number of steps and the lower the cost.

Next, the second means is to use a tape guide sound provided in the inside of one of the four-part seven-circle body at a position not in contact with both end surfaces of the first means.

However, it is desirable that the concave portions be symmetrical with respect to both ends of the cylinder and the center of j, but if it is too close to one end surface, the fitting part with the metal shaft on the one end surface side will be too narrow, and the cylinder As long as your body can't support it, it's okay.

Comparing the costs of GL and Fuku 2, Vermilion 2's method is cheaper and cheaper.

"Operation" The relationship between the axial length ρ and fl [diameter d] of the recess inside the cylindrical body (overall length io, outer diameter do, inner g dx ) is
If it exceeds 11ft, the wall thickness of the cylinder will be different between the outer circumference 9111 surface near the end of the cylinder and the outer circumferential side surface with a recess on the inner i11, so there will be a difference in deformation resistance when machining the outer circumferential side surface, so there will be a difference in the outer diameter after machining. occurs, and the straightness 1 required for the tape guide
I am not satisfied with the degree.

“Example” First example of use of the ceramic tape guide of the present invention
This will be explained using figures. The ceramic tape guide 1 of the present invention has a cylindrical appearance, but has a concave portion 1a having a common center with the cylindrical body. Fitting portions 1b that fit with the metal shaft 2 are provided on both end surfaces of the recess 1a.

The ceramic tape guide 1 of the present invention has an outer diameter of +0.01, a diameter of 8 (±0.02) txx, and an inner diameter of 6 (-o, oo).
-'The total length is 20 (±0.01) m and the straightness of the outer diameter part in the axial direction is 5 μm or less.

A method of manufacturing the tape guide 1 will be explained below.

First, a powder containing silicon nitride as a main component is pressure-molded, fc-processed, and then cut to form a molded body with a cylindrical body on the outside and a concave portion with varying axial and radial lengths on the inside. obtain. Then, it is sintered to obtain a silicon nitride sintered body (processing 1i1) (its dimensions are shown in Table 1). Process 1b.

Second, the outer diameter surface is processed using a cylindrical grinder.

As shown in the axial cross-sectional view shown in Figure 2, the dimensions after processing are as follows: the outer diameter is a (= 8 mm), and the inner diameter is dl (= 6 m).
) and the total length was fly (= 20 m).

Since there is no need to perform fim processing on the recess, before and after machining, if the radial length l and axial length d of the recess exceed 1, the straightness will be 6.5 (μm), and the tape guide The accuracy required for this cannot be achieved.

In addition, Table 1 shows the ratio of machining time when the entire inner diameter surface is machined without forming a recess inside as in Magnet 8 (comparative example), with m manpower time set as 1. : The longer the length of the sea urchin recess, the longer the machining time for the same diameter part.If the present invention has mechanical strength like ceramic, the Ω
Even if it is ≧0.5ft, the fit is strong enough! I can hold it. The longer Ω is, the more the inner diameter of the fitting part 1
The grinding length (Qo-fl) of b can be shortened.

The f'L provided in the workpiece shall be such that the straightness of the outer circumferential surface of the loquat is satisfied by 10tIj without producing any bending sound when the outer circumferential surface is cut.

``Effects'' This invention is extremely useful in industry, as it makes it possible to replace ceramic tape guides that can be manufactured at low cost in order to meet the demand for storage capacity in order to meet the demands of four generations.

[Brief explanation of drawings]

Figure 1: Seven examples of convenient use of the Cefmic tape guide in its original form. Figure 2 shows the center of Mitsuaki's Cefmic tape guide, with the rusted axis aligned 10,000 times wfr flush. 1... Cefmic tape guide, La... recess,
1b...Fitting part with metal shaft, 2...Metal shaft, Q
,...Full length of tape guide, d...Diameter of recess, do
... Tape guide outer diameter, Q ... Axial length of four parts,
dl... Tape guide inner diameter Patent applicant: Nihon Tokushu Togyo Co., Ltd. Suzuki Tei - Figure 1 Figure 2 Figure 1 ' 11-do --ya

Claims (2)

[Claims] (1) A cylindrical body that is fitted onto a metal shaft and whose outer peripheral surface slides on the magnetic tape, is made of ceramic and has a recessed portion inside the cylindrical body that has a common central axis with the cylindrical body,
The size of the recess is the total length of the cylindrical body l_0 and the outer diameter d_0
, the inner diameter d_1, the axial length of the convex portion l, and the diameter d, then d_0^4-d_1^4/d_0^4-d^4×(l/
A tape guide characterized by satisfying the formula: l_0)^3≦1. (2) The tape guide according to claim (1), characterized in that one recess is provided inside the cylindrical body at a position that does not touch the inside of both end surfaces.