JPH08167128A - Cylinder for vtr - Google Patents

Abstract

PURPOSE: To prevent the complication of the shape of plastic molding parts by leading out the output line from a rotary transformer for outputting the VTR signals from a magnetic head to an external circuit without providing a stationary cylinder section with notches and holes. CONSTITUTION: Ball bearings 8, 8 which pivotally support a revolving shaft 15 of this cylinder for VTRs are mounted via a pair of metallic bearing press- fitting parts 7, 7 to a bearing supporting body 6 made of plastic. The dimensional accuracy is made higher than the dimensional accuracy of the case the ball bearings 8, 8 are internally fitted by press fitting. The outer cylindrical part 9c of the stationary cylinder body section 9 molded of the plastic is not provided with notches, etc., for the purpose of leading out the output signal lines 5a from the rotary transformer 5 on the stationary side to the external circuit. As a result, the shape is not intricate and the degradation of the dimensional accuracy is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a VTR cylinder having a plastic molding portion.

[0002]

2. Description of the Related Art A conventional VTR cylinder is generally made of a metal material such as aluminum. After being formed by cold forging or casting, as shown in FIG. The bearing press-fitting portion C was precision processed by turning.

However, it has been limited to suppress the cost from the viewpoint of equipment, processing time, etc. to obtain the processing accuracy required for the VTR cylinder by turning using a metal material such as aluminum as a raw material. .

Further, since the conventional VTR cylinder is formed by cold forging or casting, the coefficient of friction is relatively high at about 0.4, the VTR tape is easily damaged, and the reproduced image is adversely affected. May be caused. Particularly, in a VTR cylinder formed by casting, a casting defect occurs on the surface thereof, and this defect is one of the causes of making the running of the VTR tape unstable.

Therefore, in consideration of the above-mentioned drawbacks, recently,
For example, as disclosed in JP-A-60-40550, it has been attempted to mold a VTR cylinder body with plastic.

In the conventional plastic VTR cylinder, however, as shown in FIG. 4, the output signal line F from the rotary transformer E housed in the fixed cylinder D is connected to an external circuit (not shown). A notch G (not shown but may be a hole) is provided for cutting.

However, the notch G is formed at the same time as the plastic molding of the fixed cylinder D or after the plastic molding by machining. Therefore, the shape accuracy of the fixed cylinder D is deteriorated, which is an obstacle to improving the performance of the product.

[0008]

As described above, in the conventional VTR cylinder molded by plastic, the notch (hole) for connecting the output signal line from the rotary transformer to the external circuit is post-processed. Therefore, the shape accuracy is deteriorated. The present invention has been made in view of the above circumstances, and an object thereof is to provide a VTR cylinder that can solve the above-mentioned problems.

[0009]

The VTR cylinder of the present invention comprises a plastic fixed cylinder portion and a rotary cylinder portion rotatably held by the fixed cylinder portion, and is provided in the rotary cylinder portion. V from magnetic head
The output line from the rotary transformer for outputting the TR signal to an external circuit is led out to the outside without providing a notch or a hole in the fixed cylinder portion.

[0010]

According to the VTR cylinder of the present invention, it is possible to prevent the shape of the plastic molding portion of the fixed cylinder portion from becoming complicated, so that it is possible to prevent the deterioration of the shape accuracy and the dimensional accuracy, and eventually the VTR. It can contribute to performance improvement.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 shows a VTR cylinder of this embodiment. The VTR cylinder is composed of a fixed cylinder portion 1 fixedly provided and a rotary cylinder portion 2 rotatably held by the fixed cylinder portion 1.

Therefore, the fixed cylinder portion 1 has a cylindrical bearing portion 3, a fixed cylinder cylinder 4 having a bottom for holding the bearing portion 3, and a fixed side rotary transformer 5 provided on the fixed cylinder 4. It consists of The bearing 3 includes a sleeve 3a made of metal such as aluminum (Al), a pair of press-fitted portions 7 made of metal such as aluminum (Al) fixed to the sleeve 3a by press fitting, and the like. Ball bearings 8 and 8 which are press-fitted and fixed to the bearing press-fitting portions 7 and 7. And the sleeve 3a
Has a stepped structure and is composed of a large diameter portion 6a located on the lower side and a small diameter portion 6b continuously provided coaxially with the large diameter portion 6a and having ball bearings 8, 8 pressed into both ends. . The upper end plate 6c of the large-diameter portion 6a is provided with a through hole 6d which is a circular small hole. The fixed cylinder 4 is formed by plastic molding into a bottomed cylinder, and a ring-shaped rotary transformer 5 is integrally fixed to the inner bottom of the fixed cylinder main body 9 and the outer surface of the fixed cylinder main body 9. A lead portion 10 which is attached along the circumferential direction by an insert molding method and forms a lead surface for guiding and running a VTR tape, which is made of a metal such as aluminum (Al) for guiding the running of a VTR tape (not shown); A plurality of pin-shaped mounting portions 11 made of a metal such as aluminum (Al) for engaging a VTR casing (not shown), which are provided on the lower surface of the fixed cylinder body 9 so as to project by insert molding. It consists of ... The fixed cylinder body 9 has an inner cylindrical portion 9b in which the large-diameter portion 6a is integrally held and fixed by insert plastic molding, and an outer cylindrical portion 9c coaxially arranged outside the inner cylindrical portion 9b. When,
The inner cylinder portion 9b and the outer cylinder portion 9c are connected to each other, and the bottom portion 9d is fixed to the rotary transformer 5. Thus, a void 9e forming a cylindrical space is provided between the small diameter portion 6b and the inner tubular portion 9b. Then, one end of the output signal line 5a is connected to the rotary transformer 5, and the output signal line 5a is connected to the bottom 9d and the outer cylinder 9c.
Is extended along the inner wall surface of the outer cylinder portion 9c
Is disposed below along the outer wall surface of the. Further, the output signal line 5a is loosely inserted in the through hole 6d, and the other end is connected to an external circuit (not shown). The fixed cylinder body 9 is molded by a plastic injection molding method. As plastic in this case,
For example, phenol resin, tetrafluoride resin and the like are suitable. In addition, carbon is added to such a plastic to impart conductivity to the entire fixed cylinder 4.

On the other hand, the rotary cylinder portion 2 has a rotary shaft 15 pivotally supported by the ball bearings 8 of the bearing portion 3, and the rotary shaft 15
A rotary cylinder 16 coaxially fitted and fixed to one end of the
At least a pair of magnetic heads 17, 17 mounted at symmetrical positions on the edge of the facing surface of the rotary cylinder 16 with respect to the fixed cylinder portion 1, and an extension member 16a on the rotary cylinder 16 so as to closely face the fixed rotary transformer 5. The rotary-side rotary transformer 18 mounted via the rotary-side rotary transformer 18 and an output signal line (not shown) electrically connecting the rotary-side rotary transformer 18 and the magnetic heads 17, 17 to each other. The material of the rotary cylinder 16 may be metal such as aluminum (Al) or plastic.

Next, the operation of the VTR cylinder having the above structure will be described. That is, in the VTR cylinder of this embodiment, the ball bearings 8 supporting the rotary shaft 15 are
Since it is attached to the plastic bearing support 6 via the pair of metal press-fitting portions 7, 7, the ball bearing 8,
The dimensional accuracy can be made much higher than in the case where 8 is internally fitted by press fitting. In particular, in this embodiment, a cutout or the like is specially provided in the outer cylinder portion 9c of the fixed cylinder body 9 formed by plastic injection in order to lead the output signal line 5a from the fixed rotary transformer 5 to an external circuit. Therefore, the shape is not complicated, and it is possible to prevent deterioration of the shape accuracy. Further, in the VTR cylinder of this embodiment, the lead portion 10 made of metal such as aluminum (Al) is used for the bearing support 6
Since it is insert-molded into the fixed cylinder main body that is integrally plastic-molded with, the shape accuracy of the lead surface 10a can be improved compared with the case where the lead surface 10a is directly formed on the conventional plastic-molded fixed cylinder main body. Can be higher. Further, in the VTR cylinder of this embodiment, since the mounting portions 11 ... Are equidistantly arranged on the lower surface of the fixed cylinder body 9 made of plastic and are projected by the insert molding method, the mounting portions 11 ... Assembling accuracy is significantly improved as compared with the case where the fixed cylinder body 9 is integrally formed of the same material.

Next, the VTR cylinder of the second embodiment will be described. The same symbols are used for the same parts as in the first embodiment. As shown in FIG. 2, the VTR cylinder of the second embodiment comprises a fixed cylinder portion 1 fixedly provided and a rotary cylinder portion 2 rotatably held by the fixed cylinder portion 1. ing.

Thus, the fixed cylinder portion 1 has the bearing portion 3
A fixed cylinder 4 for holding the bearing portion 3, and a fixed side rotary transformer 5 attached to the fixed cylinder 4.
It consists of The bearing portion 3 includes a pair of bearing press-fitting portions 7, 7 made of metal such as aluminum (Al).
And ball bearings 8, 8 fixed by press-fitting to these bearing press-fitting portions 7, 7. On the other hand, the fixed cylinder 4 has a cylindrical fixed cylinder body 9 made of plastic and is attached along the outer circumferential direction of the fixed cylinder body 9 by an insert molding method to guide the running of a VTR tape (not shown). The lead portion 10 is made of a metal such as aluminum (Al) and forms a lead surface for guiding and running the VTR tape. The fixed cylinder body 9 includes a bearing support portion 9m in which the bearing press-fitting portions 7, 7 are insert-molded and a cylindrical cylindrical portion extending in a cup shape at the outer lower end of the bearing support portion 9m. It consists of 9n. The rotary transformer 5 is fixed to the bottom surface of the bearing support portion 9m by, for example, bonding. Then, one end of the output signal line 5a is connected to the rotary transformer 5. The output signal line 5a is attached along the bottom surface of the bearing support portion 9m and the inner wall surface of the cylindrical portion 9n, and the other end portion is connected to an external circuit (not shown). The fixed cylinder body 9 is molded by a plastic injection molding method. As plastic in this case,
For example, phenol resin, tetrafluoride resin and the like are suitable. In addition, carbon is added to such a plastic to impart conductivity to the entire fixed cylinder 4.

On the other hand, the rotary cylinder portion 2 includes a rotary shaft 15 supported by the ball bearings 8 of the bearing portion 3, and the rotary shaft 15
A rotary cylinder 16 coaxially fitted and fixed to one end of the
At least a pair of magnetic heads 17 and 17 are attached at symmetrical positions on the edge of the facing surface of the rotary cylinder 16 with respect to the fixed cylinder portion 1, and a ring shape attached to the rotary shaft 15 so as to closely face the fixed rotary transformer 5. Rotation side rotary transformer 1 provided via the support plate 15a of
8, the rotary transformer 18 for rotation and the magnetic head 1
The output signal line 18a electrically connects 7 and 17. Then, the output signal line 1 is attached to the rotary shaft 15.
A guide hole 15b for inserting 8a is provided at a coaxial position. Both ends of the guide hole 15b are open to the side surface, and the output signal line 18a can be inserted therethrough. Thus, the output signal line 18a, one end of which is connected to the magnetic heads 17, 17, is connected to the guide hole 15b from the one end opening of the guide hole 15b.
After being inserted in b, it is inserted from the other end opening,
It is connected to the rotary rotary transformer 18 via the upper surface of the support plate 15a. The material of the rotary cylinder 16 may be metal such as aluminum (Al) or plastic.

The VTR cylinder of the second embodiment having the above-described structure has the same operation and effect as the VTR cylinder of the first embodiment, but in this case, in particular, the fixed cylinder body 9 is replaced by the first cylinder. Since it is not necessary to form a double cylinder like the VTR cylinder of the above embodiment, the structure is simplified,
The effect of preventing shape accuracy can be enhanced.

Next, the VTR cylinder of the third embodiment will be described. The same symbols are used for the same parts as in the first embodiment. As shown in FIG. 3, the VTR cylinder of the third embodiment comprises a fixed cylinder portion 1 fixedly provided and a rotary cylinder portion 2 rotatably held by the fixed cylinder portion 1. ing.

Therefore, the fixed cylinder portion 1 has the bearing portion 3
And a fixed cylinder 4 which holds the bearing portion 3. The bearing 3 is made of, for example, aluminum (A
1) A pair of metal bearing press-fitting portions 7, 7 and ball bearings 8, 8 fixed to these bearing press-fitting portions 7, 7 by press-fitting. On the other hand, the fixed cylinder 4 has a cylindrical fixed cylinder body 9 made of plastic and is attached along the outer circumferential direction of the fixed cylinder body 9 by an insert molding method to guide the running of a VTR tape (not shown). A lead portion 10 formed of a metal such as aluminum (Al) to form a lead surface for guiding and running the VTR tape.
And a pin-shaped mounting made of metal such as aluminum (Al) for being equally arranged on the lower surface of the fixed cylinder body 9 and protruding by an insert molding method to engage with a VTR housing (not shown). Part 11 ... Thus, the fixed cylinder body 9 has the bearing press-fitting portions 7, 7
Is insert plastic molded. The fixed cylinder body 9 is molded by a plastic injection molding method. As the plastic in this case, for example, phenol resin, tetrafluoride resin and the like are suitable. In addition, carbon is added to such a plastic to impart conductivity to the entire fixed cylinder 4.

On the other hand, the rotary cylinder portion 2 has a pipe-shaped rotary shaft 15 axially supported by the ball bearings 8 of the bearing portion 3, and a bottomed end coaxially fitted and fixed to one end portion of the rotary shaft 15. Cylindrical rotating cylinder 16, magnetic heads 17, 17 mounted at least in pairs at the symmetrical positions of the facing cylinder edge of rotating cylinder 16 with respect to fixed cylinder portion 1, and the rotating side mounted on the inner bottom surface of rotating cylinder 16. It comprises a rotary transformer 18 and an output signal line 18a for electrically connecting the rotary transformer 18 with the magnetic heads 17, 17. The material of the rotary cylinder 16 may be a metal such as aluminum (Al),
It may be plastic.

Further, a fixed post 15d fixed to a fixed member (not shown) is loosely inserted in the rotary shaft 15. A disc-shaped support plate 15e is fixed to the upper end of the fixed post 15d, and the fixed rotary transformer 5 is attached to the lower surface of the fixed post 15d so as to closely face the rotary rotary transformer 18. Has been. The fixed-side rotary transformer 5 has an output signal line 5
One end of a is connected. The other end of the output signal line 5a is connected to an external circuit (not shown) via the hollow portion of the rotary shaft 15.

The VTR cylinder of the third embodiment having the above-described structure has the same operation and effect as the VTR cylinder of the first embodiment, but in this case, in particular, the fixed cylinder main body portion 9 is the first cylinder. Since it is not necessary to form a double cylinder like the VTR cylinder of the embodiment, the structure is simplified and the effect of preventing the shape accuracy can be enhanced. Further, the fixed cylinder main body 9 having a simple columnar body to improve rigidity also helps prevent shape accuracy.

In the above embodiment, the ball bearings 8,
Although 8 has a structure in which it is press-fitted and fixed to the bearing press-fitting portions 7, 7, they may be integrally molded. The action and effect in this case are not different from those described above. Further, although the method of molding only the fixed cylinder portion 1 with the plastic resin has been described, not only the fixed cylinder portion 1 but also the rotating cylinder portion 2 may be molded with the resin. Further, in the second and third embodiments, the bearing press-fitting portions 7, 7 are directly held by the fixed cylinder body portion 9, but the bearing press-fitting portions 7, 7 are fixed to the fixed cylinder body portion 9 via the sleeve. You may make it hold | maintain.

[0025]

The VTR cylinder of the present invention comprises a plastic fixed cylinder portion and a rotary cylinder portion rotatably held by the fixed cylinder portion. The output line from the rotary transformer for outputting the VTR signal to the external circuit is led out to the outside without providing a notch or a hole in the fixed cylinder portion. As a result, it is possible to prevent the shape of the plastic molding portion of the fixed cylinder portion from becoming complicated, so that it is possible to prevent deterioration in shape accuracy and dimensional accuracy. As a result, the performance of the VTR can be improved.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a VTR cylinder according to a first embodiment of the present invention.

FIG. 2 is a sectional view of an essential part of a VTR cylinder according to a second embodiment of the present invention.

FIG. 3 is a cross-sectional view of essential parts of a VTR cylinder according to a third embodiment of the present invention.

FIG. 4 is an explanatory diagram of a conventional technique.

[Explanation of symbols]

1: Fixed cylinder part, 2: Rotating cylinder part, 5: Fixed side rotary transformer, 5a: Output signal line, 8: Ball bearing, 1
0: lead part, 11: mounting part, 18: rotary side rotary transformer, 18a: output signal line.

Claims (4)

[Claims] 1. A rotary cylinder unit having a magnetic head and a rotary rotary transformer for inputting a signal from the magnetic head, a fixed rotary transformer provided facing the rotary rotary transformer, and the fixed rotary transformer. A stationary cylinder having a stationary side output line for transmitting a signal output from the outside to rotatably holding the rotating cylinder part, the stationary cylinder part supporting the rotating cylinder part as a bearing. And a fixed cylinder made of plastic for holding the bearing section, and the fixed output line is led to the outside via the bearing section. 2. A bearing portion has a sleeve and a bearing press-fitted and fixed to the sleeve, and the sleeve has a large diameter portion held by a fixed cylinder made of plastic and is coaxial with the large diameter portion. The fixed cylinder is formed in a double cylindrical shape in which a fixed-side rotary transformer is attached to an inner bottom portion of the fixed cylinder, which has a small diameter portion that is continuously provided to hold the bearing and forms a gap between the fixed cylinder and the fixed cylinder. The fixed-side output line from the fixed-side rotary transformer is routed to the void through the fixed cylinder and led out to the outside via a through hole provided in the end plate of the large-diameter portion. The VTR cylinder according to claim 1, characterized in that: 3. A fixed-side rotary transformer is attached to the lower end surface of the fixed cylinder, the rotary cylinder part is pivotally supported by a bearing part through a hollow rotary shaft, and the rotary cylinder part is attached to the lower end part of the rotary shaft. Is attached at a position where the rotary side rotary transformer closely faces the fixed side rotary transformer, and
The rotation-side output line from the magnetic head is connected to the rotation-side rotary transformer through the hollow portion of the rotation shaft, and the fixed-side rotary transformer is directly led to the outside from the lower end surface side of the fixed cylinder. The cylinder for VTR according to claim 1, wherein 4. The rotating cylinder portion is a bottomed cylindrical shape that is axially supported by a bearing portion via a pipe-shaped rotating shaft and has a rotary rotary transformer attached to the inner bottom portion thereof.
The fixed cylinder portion has a fixed post loosely inserted in the rotary shaft, a fixed rotary transformer mounted on the fixed post and closely facing the rotary rotary transformer, and one end thereof connected to the fixed rotary transformer. 2. The VTR cylinder according to claim 1, wherein the VTR cylinder has a fixed-side output line led to the outside via a rotary shaft.