JP3337366B2 - Magnetic recording / reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a magnetic recording / reproducing drum composed of a rotating drum and a fixed drum, such as a video tape recorder (hereinafter referred to as VTR) and a digital audio tape recorder (hereinafter referred to as DAT). The present invention relates to a magnetic recording / reproducing apparatus, and more particularly to a magnetic recording / reproducing apparatus capable of stably fixing a magnetic recording / reproducing drum without distortion.

[0002]

2. Description of the Related Art In recent years, magnetic recording devices have tended to have higher and higher recording densities. In particular, in an apparatus for reading and writing signals using a magnetic recording / reproducing drum having a magnetic head typified by a VTR mounted on the drum, precise magnetic tape guidance is required to achieve high recording density. is there.

[0003] As is well known, a magnetic recording / reproducing drum is composed of a fixed drum and a rotating drum on which a magnetic head is mounted and which rotates along a central axis. Leads are formed on the outer peripheral surface of the fixed drum for the purpose of accurately guiding the magnetic tape. Therefore, the linearity must be precise and is an important factor for the magnetic recording / reproducing characteristics together with the roundness of the outer periphery of the fixed drum.

[0004] On the other hand, thinning of parts, reduction of material costs and processing costs are important issues due to demands for weight reduction and cost reduction. In particular, the technology for forming a rotating drum or a fixed drum from a resin material is important. Active development. Resin materials are not only lighter than conventional metal materials such as aluminum alloys, but also can use processing methods such as injection molding, so they have sufficient advantages in handling complex shapes and reducing costs. Can be expected.

[0005] Here, a conventional magnetic recording / reproducing drum of a VTR will be described. FIG. 29 is a cross-sectional view around a magnetic recording / reproducing drum of a VTR device that records and reproduces a signal using a magnetic recording / reproducing drum using a magnetic tape as a medium.

The magnetic recording / reproducing drum 203 includes a rotating drum 201, a fixed drum 202, a central shaft 204, a magnetic head (not shown), a rotating motor, a rotary transformer, a ball bearing, and the like. The rotating drum 201 and the fixed drum 202 are formed by injection molding a resin material.
No. 01 is formed by cutting a metal material such as an aluminum alloy. The shape and dimensional accuracy are in units of 1/1000 mm, and these components are precisely assembled to form the magnetic recording / reproducing drum 203.

Next, a method for fixing the magnetic recording / reproducing drum 203 will be described. On the bottom of the fixed drum 202,
A plurality of female screws 202a are opened, and are fixed to the drum base 205 by a plurality of male screws 206. Further, the drum base 205 is fastened and fixed to the main chassis portion 208 of the magnetic tape traveling mechanism main body by a male screw 207.

[0008]

The magnetic recording / reproducing drum 203 is used to accurately record and reproduce signals.
It must be firmly fixed to the main chassis 208. However, at this time, if the flatness of the reference surface of the drum base for positioning the magnetic recording / reproducing drum 203 is not sufficiently high, the fixed drum 2 is tightened by the tightening force of the male screw 206.
02 is deformed, and the linearity of the leads 202b formed on the fixed drum 202 and the roundness of the outer peripheral surface of the fixed drum 202 are deteriorated.

Further, when the above-mentioned resin composite material is used as a drum material for magnetic recording / reproducing, it is easy to deform when fixed, or hardly deforms in the initial state, from the viewpoint of elastic strength. The following time-dependent changes (generally called “creep distortion”) occur, and the roundness of the outer peripheral portion of the fixed drum is deteriorated, and the linearity of the lead portion, which serves as a guide for the magnetic tape, is deteriorated. The linearity does not fall within the specified value, which may have an adverse effect on signal recording and reproduction. In the worst case, there is a problem in that compatibility between VTR devices is impaired. Needs great care.

To cope with such a problem, for example, in Japanese Patent Application Laid-Open No. Hei 4-30361, a notch is formed in a screw tightening portion of a fixed drum so as to have elasticity, thereby preventing deformation of the fixed drum due to tightening. An anchoring method is disclosed.

However, in this method, the notch portion must be formed by post-processing, and particularly in the case of a fixed drum made of a resin composite material, it is necessary to perform secondary processing after injection molding, which is very disadvantageous in cost. There is a problem that there is.

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a magnetic recording system capable of firmly fixing a magnetic recording / reproducing drum and a magnetic tape running mechanism main body without distortion, and preventing temporal deformation, so-called creep distortion. A playback device is provided.

[0013]

In order to solve the above problems, a magnetic recording / reproducing apparatus according to the present invention is fixed on a drum base.
Fixed drum and rotating drum that rotates along the central axis
Recording / reproducing provided with a magnetic recording / reproducing drum comprising:
In the apparatus, the drum base and the magnetic recording and reproducing
The fixed drum is fixed to the drum by an attachment member.
The fixed portion of the ram is hollow.
I do. Fixed drum fixed on the drum base
And a rotating drum rotating along the central axis
In a magnetic recording and reproducing apparatus having a recording and reproducing drum,
The drum base and the fixed drum are both fibrous fillers.
Comprising a resin composite material containing
Orientation of fibrous filler and fibrous shape in the drum base
The orientation of the filler is substantially perpendicular to each other.
You. Also, a fixed drum fixed on the drum base,
Magnetic recording consisting of a rotating drum rotating along a central axis
In a magnetic recording / reproducing apparatus having a reproducing drum,
Fixed drum is made of resin composite material containing fibrous filler
Fibrous filling of the first color of the fixed drum, consisting of two-color molding
The orientation of the material and the orientation of the second color fibrous filler
It is characterized by being substantially perpendicular.

Further, in a magnetic recording / reproducing apparatus provided with a magnetic recording / reproducing drum comprising a fixed drum fixed on a drum base and a rotating drum rotating along a central axis, the drum base and the magnetic recording / reproducing And the fixing drum is fixed by an attaching member.
The thickness between the portion and the outer peripheral portion is formed to be thinner than other portions including the fixed portion. Further, in a magnetic recording / reproducing apparatus provided with a magnetic recording / reproducing drum composed of a fixed drum fixed on a drum base and a rotating drum rotating along a central axis, the drum base and the magnetic recording / reproducing drum Are fixed by a mounting member, and the fixing portion of the drum base and the drum base are fixed.
Thickness between the fixed drum and the positioning part of the fixed drum
Thickness is smaller than other parts including the fixing part.
And features. Further, the thickness may include the fixing portion.
The portion formed thinner than the portion is an annular groove .

[0015]

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) Regarding the first embodiment of the present invention,
The description will be made with reference to FIGS. 1 is a plan view of the drum base 11, FIG. 2 is a plan view showing a fixed state of the drum base 11 and the fixed drum 12, and FIG.
It is sectional drawing in -A '.

The fixed drum 12 is formed by processing a resin composite material by injection molding, and has three female threads 12a. The molding is performed in units of 1/1000 mm. In particular, the linearity of the lead and the roundness of the outer peripheral portion for the purpose of accurately guiding the magnetic tape are very important factors.

The drum base 11 is formed by processing a resin composite material by injection molding in the same manner as the fixed drum 12. As shown in FIG. 1, a hollow portion 11 b larger than the outer diameter of the fixed drum 12 is formed. I have. Further, a flange 11a protruding inward is formed, and the fixed drum 12
It is a connection part with. The thickness of the flange 11a is smaller than that of the other parts of the drum base 11, as shown in FIG. Further, a positioning projection 11c of the fixed drum 12, which is formed to project inward like the flange 11a, is formed. The positioning projection 11c is
It is formed slightly higher than 1a, has the same thickness as other parts of the drum base 11, and has sufficiently higher rigidity than the flange 11a. The fixed drum 12 is fastened and fixed with a male screw 13 based on the positioning projection 11c.

With the above construction, the fixed drum 12 can be precisely positioned, and the flange 11a of the drum base 11 is thinner than other portions of the drum base 11 and the fixed drum 12, so that the rigidity is small. Male screw 1
Even if stress is generated by the tightening and fixing of the flange 3, the flange 11
Since the distortion is concentrated on a, the fixed drum 12 is not affected by stress, distortion, deformation, or the like due to fixing, and the linearity of the lead and the roundness of the outer peripheral portion of the fixed drum 12 do not deteriorate. Therefore, a change with time due to continuous application of a stress for fixing, that is, creep deformation is small.

Incidentally, without forming the positioning projections 11c,
Even when the fixed drum 12 is positioned by the flange 11a, the effect does not change. Further, the drum base 11 and the fixed drum 12 have been described as being formed by injection molding of a resin composite material, but the materials and processing methods of the drum base and the fixed drum are not limited thereto.

(Embodiment 2) A second embodiment of the present invention will be described with reference to FIGS.

FIG. 4 is a plan view of the fixed drum 21. The fixed drum 21 formed by injection molding of a resin composite material has a flange 21 projecting from the outer peripheral portion of the fixed drum.
a is formed and serves as a connection portion with the drum base 22.

FIG. 5 is a sectional view taken along the line BB 'in FIG. 4, and shows a fixed state of the fixed drum 21 and the drum base 22. Flange 21 of fixed drum 21
a and the drum base 22 are fixed by tightening the male screw 23. The female screw 22 a is machined into the drum base 22, and the positioning of the fixed drum 21 is performed by a positioning portion 22 b of the drum base 22. Flange 21
a is thinner than the others, and the fixed drum 21
The rigidity is smaller than the outer peripheral portion.

According to the above configuration, even if distortion and deformation occur due to the fixing of the fixed drum and the drum base, the distortion and deformation occur.
The deformation concentrates on the flange 21a and does not affect the fixed drum 21.
The roundness of the outer peripheral portion of No. 1 does not deteriorate. Therefore, a change with time due to continuous application of a stress for fixing, that is, creep deformation is small.

Further, with the above configuration, the female screw conventionally formed on the fixed drum side can be formed on the drum base side. When the fixed drum 21 is formed by injection molding using a resin composite material, the female screw can be formed. This eliminates the need for secondary processing of the screw, which is advantageous in terms of cost.

As shown in FIG. 6, a similar effect can be obtained when a notch 24b is formed at the base of the flange 24a of the fixed drum 24.

It should be noted that even if the fixed drum 21 is positioned by the drum base 22 without forming the positioning portion 22b, the effect remains unchanged. As the drum base 22,
Although the form by injection molding of the resin composite material has been described, the material and processing method of the drum base are not limited to this.

(Embodiment 3) A third embodiment of the present invention will be described with reference to FIGS. FIG.
FIG. 8 is a cross-sectional view of the vicinity of the connecting portion showing a fixed state of the fixed drum 33 and the drum base 31 or 32.

In FIG. 7, the fixed drum 33 is formed by injection molding of a resin composite material, and the drum base 31 is similarly formed by injection molding of a resin composite material. The thickness of the drum base 31 in the vicinity of the male screw through hole 31a is formed thinner than other portions. For this reason, it has some spring properties and low rigidity. The vicinity of the female screw of the fixed drum 33 is a circular positioning projection 33a,
The circular concave portion 31b of the drum base 31 is fitted and positioned.

With the above configuration, the stress for fixing the fixed drum 33 to the drum base 31 is reduced.
Of the thin portion near the male screw through hole 31a is absorbed as distortion and deformation, so that the distortion and deformation do not reach the fixed drum 33, and the linearity of the lead and the roundness of the outer peripheral portion of the fixed drum 33 are deteriorated. I will not do it. Therefore, a change with time due to continuous application of a stress for fixing, that is, creep deformation is small.

As shown in FIG. 8 instead of the structure shown in FIG. 7, the same effect can be obtained even if the notch groove 32a is formed from both sides near the male screw through hole 31a of the drum base 32. it can.

Drum bases 31, 32 and fixed drum 3
As No. 3, the form of the resin composite material by injection molding is shown, but the materials and processing method of the drum base and the fixed drum are not limited to this.

(Embodiment 4) A fourth embodiment of the present invention will be described with reference to FIGS. FIG.
10 is a sectional view showing a fixed state of the fixed drum 41 or 42 and the drum base 43.

In FIG. 9, a fixed drum 41 is formed by injection molding of a resin composite material, and a drum base 43 is formed.
A female screw 41a is machined as a joint with the screw. Similarly, the drum base 43 is formed by injection molding of a resin composite material. The vicinity of the female screw 41a is formed to be thinner than other portions, and therefore, this portion has low rigidity. Further, a circular positioning protrusion 43a is formed at a portion where the drum base 43 is connected to the fixed drum, and is fitted to a positioning hole 41b of the fixed drum 41 so that positioning can be performed.

According to the above configuration, even if a distortion or deformation for fixing occurs at the connecting portion between the fixed drum 41 and the drum base 43, the distortion or deformation is concentrated on a thin portion near the female screw 41a. 41 is the stress due to fixing,
There is no influence by distortion, deformation, etc., and the linearity of the lead and the roundness of the outer peripheral portion of the fixed drum 41 do not deteriorate. Therefore, a change with time due to continuous application of stress for fixing to the fixing drum 41, that is, creep deformation is small.

As shown in FIG. 10, in place of the above-mentioned structure, cut-out grooves 42a
The same effect can be obtained even if the shape is formed by molding. Further, the drum base 43 and the fixed drums 41, 4
As No. 2, the form of the resin composite material by injection molding is shown, but the material and processing method of the drum base and the fixed drum are not limited to this.

(Embodiment 5) A fifth embodiment of the present invention will be described with reference to FIGS.

FIG. 11 is a sectional view showing a fixed state of the fixed drum 51 and the drum base 52. Fixed drum 51
Is formed by injection molding of a resin composite material, and a female screw 51a for tightening and fixing the drum base 52 is processed. Also, as shown in FIG.
1a, a circular cutout groove 5 along the outer circumference
1b is formed. Similarly, the drum base 52 is formed by injection molding of a resin composite material. On the drum base 52, positioning protrusions 52a for positioning the fixed drums 51 and 53 are formed.

In the above configuration, the female screw 5 of the fixed drum 51
A stress for fixing is applied to the portion 1a to cause distortion, deformation, and the like. The distortion and deformation are alleviated by the notch groove 51b. Therefore, the linearity of the leads of the fixed drum 51 and the roundness of the outer periphery of the fixed drum 51 do not deteriorate.
Therefore, a change with time due to continuous application of a stress for fixing, that is, creep deformation is small.

As shown in FIG. 13, the same effect can be obtained by forming a cutout groove 53 a on one side of the outer periphery of the fixed drum 53 instead of the above structure. Also,
Even when the positioning drum 52 is not formed and the fixed drum 51 is positioned by the drum base 52, the effect does not change.

The drum base 52 and the fixed drum 5
Although the forms 1 and 53 are shown by injection molding of a resin composite material, the materials and processing methods of the drum base and the fixed drum are not limited to these.

(Embodiment 6) A sixth embodiment of the present invention will be described with reference to FIGS.
FIG. 14 is a plan view of the fixed drum 61, and FIG.
FIG. 7 is a cross-sectional view showing a fixed state of a fixed drum 61 and a drum base 62.

The fixed drum 61 is formed by injection molding of a resin composite material, and has a female screw 61a for tightening and fixing the drum base 62. Female screw 61a
14, a circular groove 61b is formed as shown in FIG. 14, and the sectional view thereof is as shown in FIG.
Similarly to the fixed drum 61, the drum base 62 is formed by injection molding of a resin composite material, and has a positioning projection 62a for positioning the fixed drum 61.

According to the above configuration, even if distortion or deformation for fixing occurs at the joint portion of the fixing drum 61, the distortion or deformation is reduced by the thin portion near the female screw 61a or the groove 61b. The outer peripheral portion of the drum 61 is not affected. Therefore, the outer peripheral portion of the fixed drum 61 is not affected by stress, distortion, deformation, or the like due to fixing, and the linearity of the lead and the roundness of the outer peripheral portion of the fixed drum 61 do not deteriorate. Therefore, a change with time due to continuous application of a stress for fixing, that is, creep deformation is small.

Note that the positioning projections 62a are not formed,
Even when the positioning is performed by the drum base 62, the effect does not change. Further, the drum base 62 and the fixed drum 61
As, the form of the resin composite material by injection molding was shown, but the material of the drum base and the fixed drum, the processing method,
It is not limited to this.

(Seventh Embodiment) A seventh embodiment of the present invention will be described with reference to FIGS.

FIG. 16 is a sectional view showing a fixed state of the drum base 71 and the fixed drum 72. Fixed drum 72
Is formed by injection molding of a resin composite material, and has a female screw 72a for tightening and fixing the drum base 71. Similarly, the drum base 71 is formed by injection molding of a resin composite material, and has a through hole 71 a for passing the female screw 73.

As shown in FIG. 17, a circular groove 71b surrounding the through hole 71a is formed in the vicinity of the through hole 71a, and the sectional shape thereof is as shown in FIG. Also,
The positioning of the fixed drum 72 is performed by a positioning portion 71c of the drum base 71.

With the above configuration, the stress generated when the fixed drum 72 is fixed is made constant by the resiliency of the circular groove 71b. However, the distortion and deformation are alleviated by the thin portion of the circular groove 71b near the through hole 71a.
Therefore, the fixed drum 72 is not affected, and the linearity of the lead and the roundness of the outer peripheral portion of the fixed drum 72 do not deteriorate. Therefore, a change with time due to continuous application of a stress for fixing, that is, creep deformation is small.

The effect is not changed even if the positioning is performed by the drum base 71 without forming the positioning portion 71c.
Further, as the drum base 71 and the fixed drum 72,
Although the form by injection molding of the resin composite material has been described, the material of the drum base and the fixed drum and the processing method are not limited thereto.

(Eighth Embodiment) An eighth embodiment of the present invention will be described with reference to FIG.

FIG. 18 is a sectional view of the fixed drum 81. The fixed drum 81 is formed by injection molding of a resin composite material. At this time, a male screw 82 is insert-molded. A nut 84 is used for fixing to the drum base 83.

With the above configuration, when the fixed drum 81 is injection-molded, it is not necessary to form a female screw for fixing by secondary processing, so that the process can be simplified and the cost is advantageous. At the time of fixing, since the torsional stress due to the tightening of the female screw portion and the male screw portion does not directly reach the fixed drum 81, the outer peripheral portion of the fixed drum 81 has
There is no influence from distortion, deformation, and the like, and the linearity of the lead and the roundness of the outer peripheral portion of the fixed drum 81 do not deteriorate. Therefore, a change with time due to continuous application of a stress for fixing, that is, creep deformation is small. Further, since secondary processing for forming the female screw is not required, it is advantageous in cost.

(Embodiment 9) A ninth embodiment of the present invention will be described with reference to FIG.

FIG. 19 is a sectional view showing a fixed state of the fixed drum 91 and the drum base 92. Fixed drum 91
Are formed by injection molding of a resin composite material,
3, a female screw 91a is machined. Similarly, the drum base 92 is formed by injection molding of a resin composite material, and includes a through hole 92 a near the central shaft 93 and a fixed drum 91.
A positioning protrusion 92b for positioning the hole is machined.

According to the above configuration, the screw fixing portion is close to the central shaft 93 and far from the outer peripheral portion of the fixed drum 91, so that distortion and deformation for fixing near the female screw 91a of the fixed drum 91 occur. However, the influence does not reach the outer peripheral portion of the fixed drum 91, and the linearity of the lead and the fixed drum 91
The roundness of the outer peripheral portion is not deteriorated. Therefore,
The change with time due to the continuous application of the stress for fixing, that is, the creep deformation is small.

The drum base 92 and the fixed drum 9
As 1, the form by injection molding of the resin composite material is shown, but the material of the drum base and the fixed drum and the processing method are not limited thereto.

(Embodiment 10) A tenth embodiment of the present invention will be described with reference to FIG.

FIG. 20 is a sectional view showing a fixed state of the fixed drum 101 and the drum base 102. The fixed drum 101 is formed by injection molding of a resin composite material, and the drum base 102 is similarly formed by injection molding of a resin composite material.

As shown in FIG. 20, the fixed drum 101 has a hollow portion 101a formed on the bottom surface of the fixed drum 101. Then, a female screw 101c is formed in the lower layer portion 101b of the two-layer structure, and fixed with the male screw 103.

According to the above configuration, distortion due to stress at the time of fixing is absorbed by the lower portion 101a of the thin two-layer structure.
The outer peripheral portion of the fixed drum 101 is an upper layer portion 101 having a two-layer structure.
d, it does not affect the roundness of the outer peripheral portion of the fixed drum 101 or the linearity of the lead, and changes with time due to continuous application of stress for fixing, that is, creep deformation. small. Also, the lower layer portion 101b
Even if a through hole is formed in the upper layer portion 101d and a female screw is formed in the upper layer portion 101d, it is possible to prevent the outer peripheral portion of the fixed drum 101 from being distorted due to elastic deformation of the upper layer portion 101d. Obtainable.

(Embodiment 11) An eleventh embodiment of the present invention will be described with reference to FIG. FIG.
FIG. 3 is a cross-sectional view showing a fixed state of a fixed drum 111.

The fixed drum 111 is formed by injection molding of a resin composite material, and has an H-shaped cross section parallel to the central axis as shown in FIG. As described above, since the shape of the fixed drum 111 is symmetrical with respect to the gate position 111a, the stress distribution and fiber orientation at the time of molding are also symmetrical to the shape, and the fixed drum 111 is fixed to the drum base 112. Deformation is not biased with respect to the stress in the process. Further, since the cross-sectional shape is H-shaped, the mechanical strength against external force is improved as compared with the conventional concave type, so that the linearity of the lead and the roundness of the outer peripheral portion of the fixed drum 111 do not deteriorate. Therefore, a change with time due to continuous application of a stress for fixing, that is, creep deformation is small. Furthermore, since the stress distribution and fiber orientation during the above-mentioned forming process are symmetric with respect to the central axis, there is also an effect that the forming accuracy is improved.

Although the fixed drum 111 has been described as being formed by injection molding of a resin composite material, the material and processing method of the drum base and the fixed drum are not limited thereto.

(Twelfth Embodiment) A twelfth embodiment of the present invention will be described with reference to FIGS. FIG. 22 is a cross-sectional view of the fixed drum 121, FIG. 23 is a conceptual diagram showing the orientation direction of the fibrous filler in the fixed drum 121, and FIG. .

The fixed drum 121 is formed by injection molding a resin composite material in which glass fiber, carbon fiber, and other fibrous fillers are mixed with a thermoplastic resin. As shown in FIG. 22, the fixed drum 121 is
1a has a mold structure that becomes a gate. The flow direction of the resin is the direction of the arrow in FIG. 22, and the longitudinal direction of the fibrous filler, that is, the orientation, matches the flow direction of the resin. Therefore, the orientation of the fibrous filler on the bottom surface of the fixed drum 121 is in the direction of the arrow in FIG.

On the other hand, the drum base 122 is also formed by injection molding a resin composite material in which glass fibers, carbon fibers, and other fibrous fillers are mixed in a thermoplastic resin. The orientation of the fibrous filler of the drum base 122 is in the direction of the arrow in FIG. 24, and is substantially perpendicular to the orientation of the bottom surface of the fixed drum 121. In order for the orientation of the drum base 122 to be in such a direction, a gate is formed at a position 122a and molding is performed. Furthermore, the above-mentioned orientation can be realized also by using a three-point gate in combination with 122b and 122c.

Thereafter, the drum base 122 and the fixed drum 121 are tightened and fixed with male screws.

In a resin composite material containing a fibrous filler, the characteristics vary greatly depending on the orientation of the fibrous filler. That is, the tensile strength, bending strength, and elastic modulus parallel to the orientation are:
It is larger than that perpendicular to the orientation. This is the same for the creep strength.

Therefore, since the orientations of the bottom surfaces of the drum base 122 and the fixed drum 121 are substantially perpendicular to each other, the weak portions due to the respective orientations are complemented. As a result, the distortion and deformation due to the fixation become extremely small. Further, as described above, it is also strong against creep strain.

If the same orientation of the fibrous filler can be realized, the position and number of gates at the time of molding are not limited to those in the above-described embodiment. The effect of the present invention does not change even if the material contains a filler having a shape other than the above, such as a sphere, a particle, a powder, or the like.

(Thirteenth Embodiment) A thirteenth embodiment of the present invention will be described with reference to FIGS.

FIG. 25 is a sectional view of the fixed drum 131. The fixed drum 131 is made of a thermoplastic resin made of glass fiber,
It is formed by two-color molding of a resin composite material containing carbon fiber and other fibrous fillers. 132 is 1
The colors 133 indicate the second color. 26 and 27
FIG. 3 is a plan view showing the orientation of the fibrous fillers of the first color and the second color, respectively. As shown in FIG. 26, the first color is a two-point gate at points 132a and 132b, and the second color is a film gate at 133a, as shown in FIG. .

In a resin composite material containing a fibrous filler, the properties vary greatly depending on the orientation of the fibrous filler. That is, the tensile strength, bending strength, and elastic modulus parallel to the orientation are greater than those perpendicular to the orientation. this is,
The same applies to the creep strength.

Therefore, since the orientations of the first and second colors of the fixed drum 131 are substantially perpendicular to each other, the weak portions due to the respective orientations are complemented. As a result, distortion and deformation due to the fixation are extremely small. Further, as described above,
It is also strong against creep strain.

If the same orientation of the fibrous filler can be realized, the position and number of gates at the time of molding are not limited to those in the above-described embodiment. In addition, the resin composite material containing the fibrous filler of the first color and the resin composite material containing the fibrous filler of the second color may be different kinds of materials. It is desirable that the thicknesses of the respective members are also substantially the same. Further, even if the resin composite material of the fixed drum 131 contains a filler having a spherical shape, a granular shape, a powder shape, or another shape other than the above, the effect of the present invention does not change at all.

(Embodiment 14) A fourteenth embodiment of the present invention will be described with reference to FIG.

FIG. 28 is a cross-sectional view showing the shapes and fixing methods of the drum base 141 and the fixed drum 142. The fixed drum 142 is formed by injection molding of a resin composite material, and the drum base 141 is similarly formed by injection molding of a resin composite material.

Drum base 141 and fixed drum 142
Has a substantially symmetric shape via the coupling surface CC ′. The fixed drum 142 is fixed to the drum base 141 by a male screw 143. Also, the drum base 141
Is fixed to the main chassis 145 by a male screw 144. Since the fixed drum 142 and the drum base 141 have a substantially symmetric shape via the coupling surface CC ′, the male screw 1
The modes in which stress distortion occurs due to the tightening of the bolts 43 are in opposite directions, and the deformations cancel each other. As a result, the deformation of the fixed drum 142 is suppressed.

That is, even if creep distortion occurs in the fixed drum 142, the drum base 141 also attempts to distort in the opposite direction. Linearity has no effect over time. Therefore, good recording and reproduction can be performed. Most preferably, the drum base 141 and the fixed drum 142 are formed by the same processing method. In the case of molding, it is more preferable that the gate position is the same.

In the above embodiment, the example in which the fixed drum and the drum base are formed by injection molding of the resin composite material has been described. However, the forming method is not limited to this.
Other methods such as extrusion molding, compression molding, cutting molding, and polishing molding may be used. The material is not limited to the resin composite material, for example, metals such as aluminum alloys, aluminum oxide, ceramics such as zirconia,
The effect of the present invention is not changed at all by other materials.

Further, for example, it is apparent that similar effects can be obtained in a magnetic recording device other than a VTR such as a DAT.

[0083]

As described above, according to the magnetic recording / reproducing apparatus of the present invention, since the material has a low elastic strength, it is deformed in an attempt to firmly fix it, or even if it is hardly deformed in the initial state, it is so-called creep The resin composite material is not distorted or deformed by the stress applied for long-term fixing called distortion, and especially the outermost roundness, which is the most important in the fixed drum, and the role of guiding the magnetic tape. This leads to the effect that the linearity of the lead portion is not degraded and good magnetic recording and reproduction can be realized.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a drum base according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a fixed state of a drum base and a fixed drum according to the first embodiment of the present invention.

FIG. 3 is a view showing a cross-sectional view taken along line AA ′ of FIG. 2;

FIG. 4 is a diagram illustrating a fixed drum according to a second embodiment of the present invention.

FIG. 5 is a diagram showing a fixed state between a drum base and a fixed drum according to a second embodiment of the present invention.

FIG. 6 is a diagram illustrating another fixed state of the drum base and the fixed drum according to the second embodiment of the present invention.

FIG. 7 is a diagram illustrating a fixed state between a drum base and a fixed drum according to a third embodiment of the present invention.

FIG. 8 is a diagram illustrating another fixed state of the drum base and the fixed drum according to the third embodiment of the present invention.

FIG. 9 is a diagram illustrating a fixed state between a drum base and a fixed drum according to a fourth embodiment of the present invention.

FIG. 10 is a diagram showing another fixed state of the drum base and the fixed drum according to the fourth embodiment of the present invention.

FIG. 11 is a diagram illustrating a fixed state of a drum base and a fixed drum according to a fifth embodiment of the present invention.

FIG. 12 is a view showing a fixed drum in FIG. 11;

FIG. 13 is a diagram showing another fixed state of the drum base and the fixed drum in the fifth embodiment of the present invention.

FIG. 14 is a diagram illustrating a fixed drum according to a sixth embodiment of the present invention.

FIG. 15 is a diagram illustrating a fixed state of a drum base and a fixed drum according to a sixth embodiment of the present invention.

FIG. 16 is a diagram illustrating a fixed state of a drum base and a fixed drum according to a seventh embodiment of the present invention.

FIG. 17 is a view showing a drum base in FIG. 14;

FIG. 18 is a diagram illustrating a fixed state of a drum base and a fixed drum according to an eighth embodiment of the present invention.

FIG. 19 is a diagram illustrating a fixed state of a drum base and a fixed drum according to a ninth embodiment of the present invention.

FIG. 20 is a diagram illustrating a fixed state between a drum base and a fixed drum according to a tenth embodiment of the present invention.

FIG. 21 is a diagram illustrating a fixed state of a drum base and a fixed drum according to an eleventh embodiment of the present invention.

FIG. 22 is a sectional view of a fixed drum according to a twelfth embodiment of the present invention.

FIG. 23 is a plan view of the fixed drum shown in FIG. 22.

FIG. 24 is a plan view of a drum base according to a twelfth embodiment of the present invention.

FIG. 25 is a sectional view of a fixed drum according to a thirteenth embodiment of the present invention.

FIG. 26 is a plan view of the fixed drum shown in FIG. 25.

FIG. 27 is a plan view of a drum base according to a thirteenth embodiment of the present invention.

FIG. 28 is a diagram illustrating a fixed state between a drum base and a fixed drum according to a fourteenth embodiment of the present invention.

FIG. 29 is a diagram illustrating a conventional example.

[Explanation of symbols]

 Reference Signs List 11 Drum base 11a Flange 11c Positioning protrusion 12 Fixed drum 12a Female screw 13 Male screw

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Kazuhiro Nishikawa 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation (56) References JP-A 1-311448 (JP, A) JP-A Hei 6 150473 (JP, A) JP-A-61-82359 (JP, A) JP-A-3-121535 (JP, U) JP-A 62-3649 (JP, U) JP-A-6-68126 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) G11B 15/61

Claims (6)

(57) [Claims] 1. A magnetic recording / reproducing apparatus provided with a magnetic recording / reproducing drum including a fixed drum fixed on a drum base and a rotating drum rotating along a central axis, wherein the drum base and the magnetic recording / reproducing are provided. A magnetic recording / reproducing apparatus, wherein the fixing drum and the fixing drum are fixed by an attachment member, and the fixing portion of the fixing drum is hollow. 2. A magnetic recording / reproducing apparatus including a magnetic recording / reproducing drum including a fixed drum fixed on a drum base and a rotating drum rotating along a central axis, wherein the drum base and the fixed drum are Magnetic recording / reproducing characterized in that the orientation of the fibrous filler in the fixed drum and the orientation of the fibrous filler in the drum base are substantially perpendicular to each other, both being made of a resin composite material containing a fibrous filler. apparatus. 3. A magnetic recording / reproducing apparatus provided with a magnetic recording / reproducing drum comprising a fixed drum fixed on a drum base and a rotating drum rotating along a central axis, wherein the fixed drum is a fibrous filling. The fixed drum is formed by two-color molding using a resin composite material, and the orientation of the fibrous filler of the first color of the fixed drum and the orientation of the fibrous filler of the second color are substantially perpendicular to each other. Magnetic recording and reproducing device. 4. A magnetic recording / reproducing apparatus provided with a magnetic recording / reproducing drum including a fixed drum fixed on a drum base and a rotating drum rotating along a central axis, wherein the drum base and the magnetic recording / reproducing device are provided. The fixing drum is fixed by a mounting member, and the fixing portion of the fixing drum is fixed.
A magnetic recording / reproducing apparatus characterized in that the thickness between the outer peripheral portion and the outer peripheral portion is formed thinner than other portions including the fixed portion. 5. A fixed drum fixed on a drum base
And a rotating drum rotating along the central axis
In a magnetic recording / reproducing apparatus having a recording / reproducing drum , the drum base and the magnetic recording / reproducing drum are mounted.
The drum base is fixed by a member.
And the fixed drum provided on the drum base.
Other parts including the fixed part with the thickness between the positioning part
Magnetic recording / reproducing device characterized by being formed thinner than
Place. 6. The thickness of a portion other than the portion including the fixing portion is set to be larger than that of the portion including the fixing portion.
The thin part is an annular groove
A magnetic recording / reproducing apparatus according to claim 4.