JPH0991806A - Magnetic recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the accuracy in the out-of-roundness of a stationary drum and the linearity of its lead part without the generation of stresses and strains by fixing of the stationary drum and a drum for a magnetic recording and reproducing device by fixing the central shaft of the drum for the magnetic recording and reproducing device and a magnetic tape traveling mechanism. SOLUTION: A drum base 15 is fixed by means of plural screws 16 to a main chassis section 14. In the central part of a drum base 15, a hole 15a of the diameter slightly larger than the diameter of the central shaft 13 is bored and the central shaft 13 is put therein and is tightened with an external screw 17 from the direction parallel with the central shaft 13 to the internal threads of its base 13a. The drum base 15 has a circular hole 15b slightly larger than the outer peripheral part of the stationary drum 12, where the drum is positioned in the direction perpendicular and parallel to the central shaft 13. Further, the drum is positioned by a positioning hole 15c and a projection 12c for positioning. Thereby, the generation of the strains and stresses in the stationary drum and the drum for the recording and reproducing device is averted and the accuracy of the linearity in the circular lead part of the stationary drum is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing apparatus having a magnetic recording / reproducing drum such as a video tape recorder (hereinafter referred to as VTR), a digital audio tape recorder (hereinafter referred to as DAT), and more particularly to a magnetic recording / reproducing apparatus. The present invention relates to a method for stably fixing a recording / reproducing drum to a magnetic tape running mechanism body without distortion.

[0002]

2. Description of the Related Art Regarding a conventional magnetic recording / reproducing apparatus, a VTR
The device will be described as an example.

[0003] In recent years, magnetic recording / reproducing apparatuses have tended to have higher and higher recording densities. For this reason, in a device for reading and writing signals using a magnetic recording / reproducing drum in which a magnetic head is mounted on a drum, such as a VTR device, a mechanism for precisely guiding and running a magnetic tape is required. is there.

As is well known, the magnetic recording / reproducing apparatus is provided with a magnetic tape traveling mechanism and a magnetic recording / reproducing drum. The magnetic tape traveling mechanism causes the magnetic tape to travel and supply it to the magnetic recording / reproducing drum. Information is read and written by a magnetic head supported by a magnetic recording / reproducing drum. On the outer peripheral surface of the fixed drum of the magnetic recording and reproducing drum,
The lead for guiding the magnetic tape to be run by the magnetic tape running mechanism is formed, its linearity must be precise, and it is an important factor together with the roundness of the outer circumference of the fixed drum. .

On the other hand, there is a demand for weight reduction and price reduction, and it is important to reduce the thickness of parts, reduce material costs, and reduce processing costs.

FIG. 10 is a sectional view showing a main part of a VTR device for recording / reproducing signals using a magnetic recording / reproducing drum with a magnetic tape as a medium.

The magnetic recording / reproducing drum 102 is mainly composed of a rotary drum 100, a fixed drum 101, a magnetic head (not shown), a rotary motor (not shown), a rotary transformer (not shown), and a ball bearing (see FIG. (Not shown), the central axis 103, and the like. The rotary drum 100 and the fixed drum 101 are usually formed by cutting a metal material such as an aluminum alloy, and have a shape and dimensional accuracy of 1/10.
The unit is 00 mm. In addition, each of the above parts is assembled by a precision process.

Next, a method of fixing the magnetic recording / reproducing drum 102 to the magnetic tape running mechanism will be described.

A plurality of screw holes are formed on the bottom surface of the fixed drum 101, and the drum base 104 and a plurality of screws 1 are provided.
Tighten and fix with 05, and further drum base 104
Is fastened and fixed to the main chassis portion 107 of the magnetic tape running mechanism with a screw 106. The magnetic recording / reproducing drum 102 is positioned in the reference plane 104a of the drum base 104 in the direction parallel to the central axis (direction of arrow B in the figure) and in the direction perpendicular to the central axis (direction of arrow A in the figure) and the center. Regarding the rotation direction of the shaft (hereinafter, this direction is referred to as “θ direction”), the protrusion 1 formed on the drum base 104
04b and the positioning hole 101 formed in the fixed drum 101
This is done in step b.

Since the magnetic recording / reproducing drum 102 accurately records and reproduces signals, the drum base 104 and thus the main chassis portion 10 of the magnetic tape running mechanism.
7, but the flatness of the reference surface 104a of the drum base 104 for positioning the magnetic recording / reproducing drum 102 is not good enough at this time, the fixing drum 101 is fixed by the tightening force of the screw 105. The lead 1 that has been deformed and is formed on the fixed drum 101
01a and the roundness of the outer peripheral surface of the fixed drum 101 are deteriorated. Further, when the fixed drum 101 is formed of a thin metal material or a resin material whose elastic strength is smaller than that of the metal material in order to reduce the weight and cost, when the fixed drum 101 is formed by the conventional fixing method, 101
The transformation of will become bigger and bigger.

To solve such a problem, there is known a magnetic recording / reproducing apparatus in which a notch is formed in a screw tightening portion of a fixed drum so that the screw tightening portion has elasticity to prevent deformation due to a tightening force of the fixed drum. (JP-A-4-30361).

[0012]

However, in the magnetic recording / reproducing apparatus described in JP-A-4-30361, the mounting strength of the fixed drum depends on the elasticity of the cutout portion, which is by no means strong. Moreover, the most important fixed drum positioning accuracy was not obtained, and the magnetic tape could not be said to have good running properties.

As described above, in the conventional magnetic recording / reproducing apparatus in which the drum base and the fixed drum are fixed by screw tightening, if the flatness of the reference surface of the drum base is not sufficiently good, it is fixed by the screw tightening force. The track linearity does not fall within the specified value due to the stress that causes the drum to twist in the screw tightening rotation direction, which deteriorates the roundness of the outer circumference of the fixed drum and impairs the linearity of the lead that guides the magnetic tape. There was a possibility. In such a case, recording and reproduction of signals may be adversely affected, and in the worst case, a big problem that compatibility between VTR devices is lost occurs. In particular, this is a problem when the fixed drum is made of a material having low rigidity (for example, a resin composite material) in order to reduce the weight and the cost.

Further, it is necessary to carry out a secondary process of forming a screw hole or a positioning hole in the fixed drum, which is a problem in the process. In addition, when the fixed drum is molded with the resin composite material, the presence of the holes does not allow the filling material to be uniformly oriented, which may deteriorate the roundness of the fixed drum.

The present invention has been made to solve the above problems, and a magnetic recording / reproducing drum is fixed to a magnetic tape running mechanism or a drum supporting member fixed to the magnetic tape running mechanism firmly and without distortion. It is an object to provide a magnetic recording / reproducing device.

[0016]

In a magnetic recording / reproducing apparatus according to a first aspect of the present invention, a central axis of a magnetic recording / reproducing drum is fixed to a tape running mechanism or a drum supporting member fixed to the tape running mechanism. There is something.

In the above structure, when the magnetic recording / reproducing drum is attached to the magnetic tape running mechanism, the central axis of the magnetic recording / reproducing drum is not the fixed drum having a small rigidity but the central axis of the magnetic recording / reproducing drum.
Since it is fixed to the magnetic tape running mechanism or the drum support member, the deformation of the fixed drum due to the stress can be suppressed.

In the magnetic recording / reproducing apparatus according to a second aspect of the present invention, the central axis of the magnetic recording / reproducing drum and the magnetic tape running mechanism or the drum supporting member are engaged with each other by the taper-shaped portions formed therein. And a magnetic recording / reproducing apparatus.

In the above construction, the taper shaped portion enables the magnetic recording / reproducing drum and the magnetic tape running mechanism body or drum supporting member to be precisely positioned. According to another aspect of the magnetic recording / reproducing apparatus of the present invention, a positioning protrusion is formed on a fixed drum of the magnetic recording / reproducing drum, and the magnetic tape running mechanism or a drum supporting member fixed to the magnetic tape running mechanism is provided with the positioning projection. A positioning hole into which the positioning protrusion is inserted is formed.

In the above structure, it is not necessary to form holes for positioning and screwing the magnetic recording / reproducing drum in the fixed drum, and the accuracy of the fixed drum can be maintained.
It is also advantageous in terms of cost. Further, when the fixed drum is molded, the filling material can be uniformly oriented, and the molding accuracy can be improved.

A magnetic recording / reproducing apparatus according to a fourth aspect of the present invention is the magnetic recording / reproducing apparatus according to the third aspect, wherein the positioning hole is an elongated hole elongated in the radial direction of the fixed drum.

As a result, it becomes possible to position the fixed drum in the rotational direction.

A magnetic recording / reproducing apparatus according to a fifth aspect of the present invention is the magnetic recording / reproducing apparatus described above, wherein at least one of the fixed drum and the rotating drum of the magnetic recording / reproducing drum is
It is made of a resin composite material.

As a result, the weight of the magnetic recording / reproducing apparatus is reduced,
The price can be reduced.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) FIG. 1 shows a first embodiment of the present invention.
The following is a description with reference to FIG. FIG.
FIG. 3 is a schematic sectional view showing a main part of a VTR device. The magnetic recording / reproducing drum 10 includes a rotary drum 11 made by cutting an aluminum alloy, a fixed drum 12 made by injection molding of a resin composite material, and a central shaft 1 made by polishing stainless steel.
It consists of three. The central shaft 13 is press-fitted into the fixed drum 12 and is further bonded by using an epoxy resin or the like. In this figure, the magnetic head, rotary motor, rotary transformer, and ball bearing are not shown. Also, regarding the magnetic tape running mechanism, the other parts of the main chassis portion 14 are not shown.

In this VTR device, the magnetic tape running mechanism runs the magnetic tape. Then, the magnetic tape slides on the outer peripheral surface of the magnetic recording / reproducing drum 10 to record / reproduce information. Since the magnetic tape is guided by the leads 12a formed on the fixed drum 12 of the magnetic recording / reproducing drum 10, the leads 12a
The linearity of a and the roundness of the outer peripheral portion of the fixed drum 12 are very important factors. Therefore, the rotary drum 11 and the fixed drum 12 are processed in units of 1/1000 mm, and are assembled with higher precision.

A method of fixing the magnetic recording / reproducing drum 10 will be described below.

A drum base (drum support member in the claims) 15 is fastened and fixed to the main chassis portion 14 of the magnetic tape running mechanism by a plurality of screws 16. The central portion of the drum base 15 has a central shaft 13 A hole 15a having a diameter slightly larger than the diameter is opened. The central shaft 13 is inserted into the hole 15a, and a male screw 17 is tightened and fixed to a female screw formed on the bottom portion 13a of the central shaft from a direction parallel to the central shaft 13. A circular hole 15b, which is slightly larger than the outer peripheral portion of the fixed drum 12, is formed in the drum base 15, and in this portion, a direction parallel to the direction perpendicular to the central axis 13 (arrow A in the figure) (see the figure). Positioning of the fixed drum 12 indicated by arrow B) is performed. In the θ direction, the positioning is performed by the positioning hole 15c of the drum base 15 and the positioning protrusion 12c of the fixed drum 12.

FIG. 2 is a perspective view showing the shape and positional relationship of the fixed drum 12, the positioning projection 12c, and the positioning hole 15c. The positioning hole 15c is a long hole that is long in the radial direction of the fixed drum 12, has a degree of freedom in the radial direction of the fixed drum 12, and can be accurately positioned in the circumferential direction. Further, since the fixed drum 12 is formed by injection molding a resin composite material, it can be integrally molded to form the positioning projection 12c, and secondary processing is not required, which is convenient in the process.

In the above structure, since the central shaft 13 is made of a hard metal, the distortion or deformation is small with respect to the tightening of the male screw 17, and even if the distortion or the deformation occurs, the central shaft 13 is not deformed. Since it is an end portion, it has no influence on the fixed drum 12 and the rotating drum 11. Therefore, the roundness of the outer peripheral portion of the fixed drum 12 and the linearity of the lead 12a are not deteriorated.

(Second Embodiment) FIG. 3 is a schematic sectional view of the periphery of a magnetic recording / reproducing drum of a VTR device according to a second embodiment of the present invention. In FIG. 3, a magnetic recording / reproducing drum 20 is composed of a rotary drum 21 processed by injection molding of a resin composite material, a fixed drum 22 processed by injection molding of a resin composite material, and a central shaft 23 polished by stainless steel. ing. The central shaft 23 is the fixed drum 2.
It is press-fitted in No. 2 and further joined using an adhesive such as an epoxy resin. In addition, the rotary drum 21 and the fixed drum 22
Are processed and assembled with high accuracy as described above. The magnetic head, rotary motor, rotary transformer, and ball bearing are not shown. Also, regarding the magnetic tape running mechanism, other parts of the main chassis portion 24 are omitted.

In this VTR device, the magnetic tape running mechanism runs the magnetic tape. Then, the magnetic tape slides on the outer peripheral surface of the magnetic recording / reproducing drum 20 to record / reproduce information.

A method of fixing the magnetic recording / reproducing drum in this VTR device will be described below.

A drum base 25 is fastened and fixed to the main chassis portion 24 of the VTR device by a plurality of screws 26, and a tapered hole (tapered portion) 25a is formed in the central portion of the drum base 25. The central shaft 23 is inserted into the tapered hole 25a, and the screw 27
When tightened and fixed by, it meshes with the taper-shaped portion 23a formed on the central shaft 23 and can be accurately positioned in the direction perpendicular to the central shaft 23 (direction of arrow A in the figure). Also,
The parallel direction of the central axis 23 (direction of arrow B in the figure) can be accurately positioned by the positioning portion 25b of the drum base 25. In the θ direction, the positioning hole 25c of the drum base 25 and the positioning projection 22c of the fixed drum 22 are arranged.
Positioning is performed by. Here, positioning hole 25c
Is a long hole that is long in the radial direction of the fixed drum 22.
2 has a degree of freedom in the radial direction and is configured to be accurately positioned in the circumferential direction. Further, since the fixed drum 22 is formed by injection molding a resin composite material, it can be integrally molded to form the positioning projection 22c, and secondary processing is not required, which is convenient in the process.

In the above construction, since the screw 27 is fastened to the central shaft 23 made of hard metal, the central shaft 23 is less likely to be distorted, and even if the distortion is caused, the circularity of the fixed drum 22 and The linearity of the lead 22a is not affected and does not cause any problem. Further, since the tapered portion 23a of the central shaft 23 and the tapered portion of the drum base 25 mesh with each other for accurate positioning, the magnetic recording / reproducing drum 20 has good positioning accuracy, and good magnetic recording / reproducing is possible.

(Third Embodiment) FIG. 4 shows a third embodiment of the present invention.
3 is a schematic cross-sectional view of the periphery of the magnetic recording / reproducing drum of the VTR device that is the embodiment of FIG. In FIG. 4, a magnetic recording / reproducing drum 30 is composed of a rotary drum 31 processed by injection molding of a resin compound, a fixed drum 32 processed by injection molding of a resin compound, and a central shaft 33 polished by stainless steel. . The central shaft 33 is the fixed drum 32.
It is press-fitted into and is joined using an adhesive such as an epoxy resin. The rotary drum 31 and the fixed drum 32 are processed and assembled with high accuracy as described above. The magnetic head, rotary motor, rotary transformer, and ball bearing are not shown. Also, the magnetic tape running mechanism is not shown in the other cases of the main chassis portion 34.

In this VTR device, the magnetic tape running mechanism runs the magnetic tape. Then, the magnetic tape slides on the outer peripheral surface of the magnetic recording / reproducing drum 30, and the magnetic head records / reproduces information.

A method of fixing the magnetic recording / reproducing drum in this VTR device will be described below.

The main chassis portion 34 of the magnetic tape running mechanism is formed with a tapered hole 34a,
It meshes with a tapered shape 33a formed on the central shaft 33. As a result, accurate positioning can be performed in the direction perpendicular to the central axis 33 (direction of arrow A in the figure).

The central shaft 33 is fixed with a screw 36 in a tapered hole 34a formed in the main chassis portion 34. In this way, the central shaft 33 is fixed by the tightening force of the screw 36, so that the fixing force is strong.

Further, for the purpose of positioning the magnetic recording / reproducing drum 30 in the direction parallel to the central axis 33 (the direction of arrow B in the figure), the cylindrical fixed drum positioning member 35 is fixed to the screw 37.
Is fixed to the main chassis portion 34 of the main body of the magnetic tape running mechanism. In the θ direction, the positioning is performed by the positioning hole 35b of the fixed drum positioning member 35 and the positioning protrusion 32b of the fixed drum 32. Here, the positioning hole 35b is a long hole that is long in the radial direction of the fixed drum 32, has a degree of freedom in the radial direction of the fixed drum 32, and can be accurately positioned in the circumferential direction. Further, since the fixed drum 32 is formed by injection molding a resin composite material, the positioning protrusion 32b is formed.
This is convenient in terms of process because it can be integrally molded to form the structure and does not require secondary processing.

In the above construction, since the central shaft 33 made of a hard metal is fastened with the screw 36, distortion is unlikely to occur, and even if distortion occurs, the roundness of the fixed drum 32 and the straight line of the lead 32a. It does not affect sexuality and does not cause any problems. Further, the taper-shaped portion 33a of the central shaft 33 and the main chassis portion 34 of the main body of the magnetic tape running mechanism.
Since the tapered portions 34a mesh with each other and position accurately, the positioning accuracy of the magnetic recording / reproducing drum 30 is good, and good magnetic recording / reproducing is possible.

(Fourth Embodiment) FIG. 5 is a schematic cross-sectional view of the periphery of a magnetic recording / reproducing drum of a VTR device according to a fourth embodiment of the present invention. The magnetic recording / reproducing drum 40 of FIG. 5 includes a rotary drum 41 processed by injection molding of a resin composite material, a fixed drum 42 processed by injection molding of a resin composite material, and a central shaft 43 polished by stainless steel. There is. The central shaft 43 is press-fitted into the fixed drum 42 and further joined by using an adhesive such as an epoxy resin. The rotary drum 41 and the fixed drum 42 are processed and assembled with high accuracy as described above. The magnetic head, the rotary motor, the rotary transformer, and the ball bearing are not shown, and the magnetic tape running mechanism is not shown in other parts of the main chassis portion 44.

In this VTR device, the magnetic tape running mechanism runs the magnetic tape. Then, the magnetic tape slides on the outer peripheral surface of the magnetic recording / reproducing drum 40, and the magnetic head records / reproduces information.

A method of fixing the magnetic recording / reproducing drum in this VTR device will be described below.

The main chassis portion 44 has a drum base 4
5 is fastened and fixed by a plurality of screws 46, and the drum base 45 has a U-shaped cross section as shown in FIG. A tapered hole 45a is formed in the lower central portion of the drum base 45, and the central shaft 43 can be positioned.

FIG. 6 is a perspective view of the vicinity of the upper end portion 43b of the central shaft 43 as seen from above in FIG. As shown in FIG. 6, a semicircular hole 45b having a diameter slightly larger than that of the central shaft 43 is formed so that the upper end 43b of the central shaft 43 can be positioned. 43
The semi-circular hole 45b having a slightly larger diameter is used for positioning, and the central shaft fixing member 48 is attached to the drum base 45 with a screw 49.
The central shaft 43 is fixed to the drum base 45 by tightening with.

The tapered shape 43a formed at the lower end of the central shaft 43 meshes with the tapered hole shape 45a of the drum base 45, and extends in the direction perpendicular to the central shaft 43 (direction of arrow A in the figure) and parallel (direction of arrow B in the figure). Can be positioned accurately.
Further, the upper end portion 43b of the central shaft 43 meshes with the semicircular hole 45b of the drum base 45, thereby accurately positioning the central shaft 43 in the right-angle direction (the direction of arrow A in the figure) and preventing the central shaft 43 from sagging. . Furthermore, for the θ direction,
Positioning hole 45c of drum base 45 and fixed drum 42
Positioning is performed by the positioning protrusion 42c. Here, the positioning hole 45c is a long hole that is long in the radial direction of the fixed drum 42, and has a degree of freedom in the radial direction of the fixed drum 42.
Can be accurately positioned in the circumferential direction. In addition, the fixed drum 42
Is formed by injection-molding a resin composite material, it can be integrally formed to form the positioning protrusion 42c, and secondary processing is not required, which is convenient in the process.

Further, the tapered hole 45a at the lower end of the drum base 45 and the tapered shape 43a of the central shaft 43 are tightened and fixed by the screw 47, and the central shaft fixing member 4 is further fixed.
8 is fastened to the drum base 45 with a screw 49, and the upper end portion 43b of the central shaft 43 is fixed to the drum base 45. Here, the drum base 45 is formed by injection molding of a resin composite material, and can easily cope with the above-mentioned U-shape.

Since the central shaft 43 is made of a hard metal, the strain is small with respect to the tightening of the screws 47 and 49,
Further, even if distortion occurs, it does not affect the roundness of the fixed drum 42 and the linearity of the lead 42a without causing any problem. Further, since the tapered portion 43a of the central shaft 43 and the tapered portion of the drum base 45 mesh with each other and perform accurate positioning, the magnetic recording / reproducing drum 40 has good positioning accuracy and good magnetic recording / reproducing is possible.

(Fifth Embodiment) FIG. 7 is a schematic sectional view of the periphery of a magnetic recording / reproducing drum of a VTR device. The magnetic recording / reproducing drum 50 includes a rotary drum 51 made by cutting an aluminum alloy, a fixed drum 52 made by injection molding of a resin composite material, and a central shaft 53 made by polishing stainless steel. The central shaft 53 is press-fitted into the fixed drum 52, and is further bonded by using an epoxy resin or the like. The rotary drum 51 and the fixed drum 52 are processed in units of 1/1000 mm and then assembled. The magnetic head, rotary motor, rotary transformer, and ball bearing are not shown in FIG. Also, regarding the magnetic tape running mechanism, the other parts of the main chassis portion 54 are not shown.

In this VTR device, the magnetic tape running mechanism runs the magnetic tape. The magnetic tape slides on the outer peripheral surface of the magnetic recording / reproducing drum 50, and the magnetic head records / reproduces information.

A method of fixing the magnetic recording / reproducing drum in this VTR device will be described below.

A drum base 55 is fastened and fixed to the main chassis portion 54 of the magnetic tape running mechanism by a plurality of screws 56, and the diameter of the drum base 55 is slightly larger than the diameter of the central shaft 53 in the central portion. The hole 55a is opened. The central shaft 53 is inserted into this hole 55a, and the male screw 57 is tightened and fixed to the screw from the direction parallel to the central shaft 53 to form the central shaft 53 at the bottom portion 53a. This hole 55
By a, the fixed drum 52 is positioned in a direction (arrow B in the figure) perpendicular to the central axis 53 (arrow A in the figure). In the θ direction, the positioning hole 55b of the drum base 55 and the positioning projection 52 of the fixed drum 52 are arranged.
Positioning is performed by b. Here, the positioning hole 55
Reference numeral b is an elongated hole that is long in the radial direction of the fixed drum 52, and has a degree of freedom in the radial direction of the fixed drum 52, and can be accurately positioned in the circumferential direction. Further, since the fixed drum 52 is formed by injection molding a resin composite material, it can be integrally molded to form the positioning protrusion 52b, and secondary processing is not required, which is convenient in the process.

In the above structure, since the central shaft 53 made of hard metal is fastened with the screw 57, distortion or deformation is unlikely to occur, and even if the distortion or deformation occurs, it is the end of the central shaft 53. So fixed drum 52 and rotating drum 5
1 is not affected at all, and in particular, the roundness of the outer peripheral portion of the fixed drum 52 and the linearity of the lead 52a are not deteriorated and are not a problem.

(Sixth Embodiment) FIG. 8 is a schematic cross-sectional view of the periphery of a magnetic recording / reproducing drum of a VTR device according to a sixth embodiment of the present invention. In this figure, a magnetic recording / reproducing drum 60 comprises a rotary drum 61 processed by injection molding of a resin composite material, a fixed drum 62 processed by injection molding of a resin composite material, and a central shaft 63 polished by stainless steel. ing. The center shaft 63 is press-fitted into the fixed drum 62, and is further joined by using an adhesive such as an epoxy resin. Further, the rotary drum 61 and the fixed drum 62 are processed and assembled with high accuracy as described above. still,
The magnetic head, rotary motor, rotary transformer, and ball bearing are not shown in FIG. As for the magnetic tape running mechanism, the main chassis 64
The other parts are not shown.

In this VTR device, the magnetic tape running mechanism runs the magnetic tape. The magnetic tape slides on the outer peripheral surface of the magnetic recording / reproducing drum 60, and the magnetic head records / reproduces information.

A method of fixing the magnetic recording / reproducing drum in this VTR will be described below.

A drum base 65 is fastened and fixed to the main chassis portion 64 of the magnetic tape running mechanism with a plurality of screws 66, and a tapered hole 65a is formed at the center of the drum base 65. When the central shaft 63 is put in the tapered hole 65a and tightened and fixed by the screw 67, the central shaft 63 meshes with the tapered shape 63a formed in the central shaft 63, and the central direction of the central shaft 63 is perpendicular (direction of arrow A in the figure) and parallel direction. The central shaft 63 and thus the fixed drum 62 can be accurately positioned in the direction of arrow B in the figure. In the θ direction, the positioning hole 65b of the drum base 65 and the positioning protrusion 62 of the fixed drum 62 are also included.
Positioning is performed by b. Here, the positioning hole 65
Reference numeral b is a long hole that is long in the radial direction of the fixed drum 62, and has a degree of freedom in the radial direction of the fixed drum 62, and can be accurately positioned in the circumferential direction. Further, since the fixed drum 62 is formed by injection molding a resin composite material, it can be integrally molded to form the positioning protrusion 62b, and secondary processing is not required, which is convenient in the process.

Since the central shaft 63 is made of a hard metal, the strain is small with respect to the tightening of the screw 67, and even if the strain occurs, the roundness of the fixed drum 62 and the lead 6 are prevented.
There is no influence on the linearity of 2a, and there is no problem. Further, since the tapered portion 63a of the central shaft 63 and the tapered portion of the drum base 65 mesh with each other for accurate positioning, the positioning accuracy of the magnetic recording / reproducing drum 60 is good, and good magnetic recording / reproducing is possible.

(Seventh Embodiment) FIG. 9 is a schematic sectional view of the periphery of a magnetic recording / reproducing drum of a VTR device according to a seventh embodiment of the present invention. In the figure, a magnetic recording / reproducing drum 70 comprises a rotary drum 71 processed by injection molding of a resin composite material, a fixed drum 72 processed by injection molding of a resin composite material, and a central shaft 73 polished by stainless steel. There is. However, here, the magnetic tape running mechanism other than the magnetic head, the rotary motor, the rotary transformer, the ball bearing and the main chassis portion 74 is not shown. The central shaft 73 is press-fitted into the fixed drum 72, and is further joined by using an adhesive such as an epoxy resin. Further, the rotary drum 71 and the fixed drum 72 are processed and assembled with high accuracy as described above.

In this VTR device, the magnetic tape running mechanism runs the magnetic tape. Then, the magnetic tape slides on the outer peripheral surface of the magnetic recording / reproducing drum 70, and the magnetic head records / reproduces information.

A method of fixing the magnetic recording / reproducing drum in this VTR will be described below.

A taper-shaped hole 74a is formed in the main chassis portion 74 of the main body of the magnetic tape running mechanism, which meshes with the taper-shaped 73a formed in the central shaft 73, and is perpendicular to the central shaft 73 (arrow A in the figure). Direction) and parallel direction (direction of arrow B in the figure). In the θ direction, the positioning is performed by the positioning hole 74b of the main chassis portion 74 of the magnetic tape running mechanism body and the positioning projection 72b of the fixed drum 72. Here, the positioning hole 74b is a long hole that is long in the radial direction of the fixed drum 72, has a degree of freedom in the radial direction of the fixed drum 72, and can be accurately positioned in the circumferential direction. Further, since the fixed drum 72 is formed by injection molding a resin composite material, it can be integrally molded to form the positioning projection, and secondary processing is not required, which is convenient in the process.

The central shaft 73 is inserted into the tapered hole 74a formed in the main chassis portion 74 of the magnetic tape running mechanism body, and the central shaft 73 is fixed with the screw 75. Since the central shaft 73 is fixed by the tightening force of the screw 75, the fixing force is strong.

Also in this embodiment, the central shaft 73 made of a hard metal is less likely to be distorted by the tightening of the screw 75, and even if the distortion is caused, the fixed drum 7 is prevented.
The circularity of 2 and the linearity of the lead 72a are not affected and cause no problem. Further, since the taper-shaped portion 73a of the central shaft 73 and the taper-shaped portion 74a of the main chassis portion 74 of the main body of the magnetic tape running mechanism mesh with each other for accurate positioning, the positioning accuracy of the magnetic recording / reproducing drum 70 is good, and good magnetic properties are obtained. Recording / playback is possible.

In the above embodiment,
Although an example in which one or both of the rotating drum and the fixed drum form the resin composite material by injection molding is shown, of course, the forming method is not limited to this, and other methods,
For example, extrusion molding, compression molding, cutting molding, polishing molding, etc. may be used, and the material is not limited to the resin composite material, and may be, for example, a metal such as an aluminum alloy, a ceramic such as aluminum oxide or zirconia, or another material. It goes without saying that the same effect can be obtained.

Further, it is obvious that the same effect can be obtained in a magnetic recording device other than the VTR device such as the DAT device.

[0069]

In the magnetic recording / reproducing apparatus of the present invention, the magnetic recording / reproducing drum is fixed by the central axis of the magnetic recording / reproducing drum and the magnetic tape running mechanism or the drum base (drum support member) fixed thereto. Since the fixing is performed by fixing, stress strain due to fixing does not occur in the fixed drum and the magnetic recording / reproducing drum, and the roundness of the fixed drum and the accuracy of the linearity of the lead portion can be improved.

Further, the central shaft and the magnetic tape running mechanism or the drum base have tapers which mesh with each other, and the taper can accurately position the magnetic recording / reproducing drum and the magnetic tape running mechanism or the drum base.

Further, since the positioning projection is formed on the fixed drum and the positioning is performed between the fixed tape and the positioning hole of the magnetic tape running mechanism body or the drum base, the air recording / reproducing drum and the magnetic tape running mechanism body or the drum base are arranged. Positioning can be performed accurately, and good signal recording / reproduction is possible. Further, since it is not necessary to provide a screw hole or a positioning hole in the fixed drum, a uniform orientation of the filling material can be obtained, the shape accuracy such as the roundness is improved, and further, the screw hole or the positioning hole can be formed. Since the subsequent processing is unnecessary, the cost of the molded product can be reduced.

Further, by forming the fixed drum by injection molding of a resin composite material, it is possible to realize weight reduction and cost reduction, and it is easy to integrally form the above-mentioned positioning protrusions, which is advantageous in terms of mold structure. .

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a main part of a magnetic recording / reproducing apparatus of a first embodiment.

FIG. 2 is a sectional view illustrating a method of positioning the fixed drum in FIG. 1 in a θ direction.

FIG. 3 is a schematic cross-sectional view showing a main part of the magnetic recording / reproducing apparatus of the second embodiment.

FIG. 4 is a schematic sectional view showing a main part of a magnetic recording / reproducing apparatus according to a third embodiment.

FIG. 5 is a schematic cross-sectional view showing a main part of a magnetic recording / reproducing apparatus of a fourth embodiment.

FIG. 6 is a cross-sectional view illustrating a method of positioning the upper end portion of the central axis of FIG.

FIG. 7 is a schematic cross-sectional view showing the main parts of a magnetic recording / reproducing apparatus of a fifth embodiment.

FIG. 8 is a schematic sectional view showing a main part of a magnetic recording / reproducing apparatus according to a sixth embodiment.

FIG. 9 is a schematic sectional view showing a main part of a magnetic recording / reproducing apparatus of a seventh embodiment.

FIG. 10 is a schematic sectional view showing a main part of a conventional magnetic recording / reproducing apparatus.

[Explanation of symbols]

10, 20, 30, 40, 50, 60, 70 Magnetic recording / reproducing drum 12, 22, 32, 42, 52, 62, 72 Fixed drum 13, 23, 33, 43, 53, 63, 73 Central shaft 14, 24, 34, 44, 54, 64, 74 Main chassis part 15, 25, 35, 45, 55, 65 Drum base 12c, 22c, 32b, 42c, 52b, 62b, 7
2b Positioning protrusions 15c, 25c, 35b, 45c, 55b, 65b, 7
4b Positioning hole 23a, 33a, 43a, 63a, 73a Shaft side taper shape part 25a, 34a, 45a, 65a, 75a Taper shape hole

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kazuhiro Nishikawa 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka

Claims (5)

[Claims] 1. A magnetic recording / reproducing apparatus for recording / reproducing information on / from the magnetic tape by using a magnetic recording / reproducing drum for supporting a magnetic head and a magnetic tape traveling mechanism for traveling a magnetic tape. A magnetic recording / reproducing apparatus in which a central axis of a reproducing drum is fixed to the tape running mechanism or a drum supporting member fixed to the tape running mechanism. 2. The magnetic recording / reproducing apparatus according to claim 1, wherein the central shaft and the magnetic tape running mechanism or the drum supporting member are meshed with each other by a taper-shaped portion formed therein. Characteristic magnetic recording / reproducing device. 3. A magnetic recording / reproducing apparatus for recording / reproducing information on / from the magnetic tape by using a magnetic recording / reproducing drum for supporting a magnetic head and a magnetic tape traveling mechanism for traveling a magnetic tape. A positioning protrusion is formed on a fixed drum of the reproducing drum, and a positioning hole into which the positioning protrusion is inserted is formed on the magnetic tape running mechanism or a drum support member fixed to the magnetic tape running mechanism. A magnetic recording / reproducing apparatus characterized in that 4. The magnetic recording / reproducing apparatus according to claim 3, wherein the positioning hole is an elongated hole that is long in the radial direction of the fixed drum. 5. The magnetic recording / reproducing apparatus according to claim 1, wherein at least one of the fixed drum and the rotating drum of the magnetic recording / reproducing drum is made of a resin composite material. Magnetic recording / reproducing device.