JP2847904B2 - Rotating head assembly for magnetic recording / reproducing device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary head assembly of a magnetic recording / reproducing apparatus such as a video tape recorder and a digital audio tape recorder, and more particularly to simplification of the structure of a rotary cylinder thereof.

[Conventional technology]

FIG. 7 is a plan view of a rotary head assembly of a conventional magnetic recording / reproducing apparatus, and FIG. 8 is a longitudinal sectional view taken along line VIII-VIII of FIG.

In the figure, (1) is a magnetic tape, and (2) is a lead groove (201) for guiding the running of the magnetic tape (1).
02) a fixed cylinder, (3) provided at the center of the fixed cylinder (2), a central shaft rotatably supported from the fixed cylinder (2) via a bearing (4), (5)
Is a rotary cylinder fixed to the center shaft (3), which comprises a flange part (500) and a main body part (501), and the flange part (500) has a center through hole (502) and a fixed cylinder at its center. Positioning protrusion (503) protruding to the opposite side from (2)
Are fixed to the central shaft (3) by press-fitting or shrink-fitting the central through-hole (502) to the central shaft (3), and the central shaft (3) and the flange fixed thereto. The support part for supporting the main body part (501) is constituted by the part (500). A center through-opening (504) for fitting the projection (503) is formed in the main body (501) corresponding to the positioning projection (503).
In (00), an axial receiving surface (506) for receiving a peripheral portion (505) of the center through opening (504) of the main body (501) is formed around the positioning projection (503). By fitting the projection (503) and the opening (504), the main body (501) can be positioned in the radial direction by the projection (503).
Axial positioning is performed by the receiving surface (506), and the screw (6) is used at a plurality of circumferentially spaced positions in the state of being positioned with respect to the flange (500). Fixed to (500). (50
Reference numeral 7) denotes an outer peripheral surface of the main body (501), and the magnetic tape (1) extends at a predetermined angle (for example, 180 °) across the outer peripheral surface (507) and the outer peripheral surface (202) of the fixed cylinder (2). )
Wrap over. The rotary cylinder (5) is divided into a flange portion (500) and a main body portion (501), and is formed by connecting the screws (6) to each other. The required predetermined assembly accuracy can be easily obtained by, for example, cutting the receiving surface (506). (7) is a magnetic head for recording information on the magnetic tape (1) or reproducing information already recorded on the magnetic tape (1). It is attached to the main body (501). Reference numeral (9) denotes a rotary transformer for transferring information between the magnetic head (7) and a fixed-side signal processing circuit (not shown) in a non-contact manner. The rotary transformer is fixed to the fixed cylinder (2). The rotary transformer (901) includes a rotary rotary transformer (901) and a rotary rotary transformer (902) fixed to the rotary cylinder (5) to face the rotary transformer (901). (10) is a motor for rotatingly driving the rotary cylinder (5).

(11) is a relay board provided on the upper surface of the rotary cylinder (5), (12) is a signal line having one end connected to the magnetic head (7), and a signal line ( The pattern (111) for soldering 12) is printed. (1
3) is a signal line whose one end is soldered to the pattern (111),
(14) is a relay board provided on the upper surface of the rotary rotary transformer (902). A pattern (not shown) is printed on the relay board (14), and one end of the relay board (14) is a signal line (15). Connected to the rotary rotary transformer (902). The other end of the signal line (13) is soldered to the other end of the pattern on the relay board (14), and thus the signal line (12) of the magnetic head (7) and the relay board (1
1) Upper pattern (111), signal line (13), relay board (1
4) It is electrically connected to the rotary transformer (902) through the above pattern and the signal line (15).

In the main body (501) of the rotary cylinder (5), a center through-opening (504) for fitting the main body (501) to the positioning projection (503) of the flange (500) for positioning is provided.
In addition to the screw insertion hole (508) for the screw (6) and the screw hole (509) for the screw (8), the hole (510) for passing the signal line (12) and the signal line (13) Hole (511) is formed. In addition to these holes, a hole (not shown) for a jig used for positioning the magnetic head (7) is usually provided.

Next, the operation of the rotary head assembly will be described. When the rotating cylinder (5) is rotated by the motor (10), the magnetic head (7) also rotates about the central axis (3) and is guided along the lead groove (201) to rotate the fixed cylinder (2) and the rotating cylinder. Outer peripheral surface of cylinder (5) (20
2), (507) Information is recorded / reproduced on / from the magnetic tape (1) running on the tape. At this time, information to be recorded or reproduced includes a rotary transformer (9), a signal line (15), a pattern on the relay board (14), a signal line (13), a pattern (111) on the relay board (11), and a signal. Data is transferred between the magnetic head (7) and the signal processing circuit via the line (12).

In order to form the rotary cylinder (5) as described above, there are generally a cutting method and a forming method.

In the case of using the cutting method, the material is cut into a predetermined outer shape, and the openings and holes (504), (508),
Holes for (509), (510), (511) and a positioning jig for the magnetic head (7) are also cut. In the case of using a molding method, the openings and holes (504), (5
08) to (511) or pins for forming holes for jigs are formed in advance, and an appropriate molding material such as resin is injected into a mold.

By the way, a molded product is generally made by injecting a molten molding material into a mold whose temperature has been controlled to be equal to or lower than the solidification temperature of the molding material. The amount of heat released from the molding material to the mold during flow in the mold is large, the temperature is greatly reduced, and the solidification is quick to the inside. Similarly, even at the part far from the gate where the molding material injected from other gates meets each other, the leading end of the molding material flow with a remarkable temperature drop contacts, so the two flows are solidified inside quickly in a short time without mixing sufficiently. , A so-called weld occurs. Therefore, in these portions, the amount of molding material for supplementing shrinkage due to cooling is small and the density is low, so that the amount of shrinkage of the molded product is large. On the other hand, the portion near the gate has a small temperature drop and is slow to solidify to the inside, so until the gate is closed by cooling and solidification, the molding material is refilled only to compensate for shrinkage due to cooling, so the density is low. It becomes higher and the shrinkage of the molded product becomes smaller. It is well known that even when a pin is formed in a mold, the flow of one molding material is divided into two flows by the pin, so that a weld occurs at a portion where the two are in contact on the downstream side of the pin.

[Problems to be solved by the invention]

As described above, in the conventional rotary head assembly, it is necessary to form a screw insertion hole for a screw for fixing the rotary cylinder to the flange portion in the main body of the rotary cylinder,
When a rotary cylinder is formed by a cutting method, it is necessary to form these holes with high accuracy, and there is a problem that the cost increases due to an increase in the number of processing steps. The cost is increased due to the complicated structure of the mold due to the necessity of forming a pin in the mold, and the weld generated around the screw insertion hole and the body due to the tightening force of the screw for fixing the body to the flange. There is a problem that accuracy is deteriorated due to local distortion of the section.

The present invention has been made in order to solve such a problem of the conventional one, and even if formed by any processing method such as a cutting method and a forming method, a predetermined accuracy can be obtained at a lower cost than the conventional one. It is an object of the present invention to provide a rotary head assembly of a magnetic recording / reproducing apparatus having a rotary cylinder obtained.

[Means for solving the problem]

The rotary head assembly of the magnetic recording / reproducing apparatus according to the present invention has an axial hole formed at an end of the central shaft on the side of the rotary cylinder, and a fastening member having a head is fixed to the hole. The peripheral portion of the central through-opening of the main body is sandwiched between the supporting portion and the receiving surface of the supporting portion.

[Action]

In the rotary head assembly configured as described above, the main body is fixed to the flange by sandwiching the periphery of the center through opening of the main body between the head of the fastening member and the receiving surface. You.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a plan view showing a rotary cylinder of a rotary head assembly according to an embodiment of the present invention as seen through a main body thereof, and FIG. 2 is a sectional view taken along line II-II of FIG. The same parts as those of the prior art are denoted by the same reference numerals, and description thereof will be omitted.

In the drawing, (301) is an axial screw hole formed at the end (302) of the center shaft (3) on the side of the rotary cylinder (5);
(16) covers the upper surface of the main body (501) of the rotary cylinder (5) and presses against the peripheral part (505) of the central through opening (504). (17) Flanges the main body (501). (50
This screw serves as a fastening member to be fixed to 0), and comprises a shaft portion (171) having a male thread and a head (172) having a larger diameter than the shaft portion (171). Screw (1) is attached to the holding plate (16).
An opening (161) having a diameter smaller than the head (172) and larger than the shaft (171) is formed, and the screw (17) is opened (1).
61) and screwed into the screw hole (301), the head (172) of the screw (17) is moved through the holding plate (16) to the peripheral portion (504) of the central through opening (504) of the main body (501). The peripheral portion (505) is thus pressed and locked against the head (172) of the screw (17) and the receiving surface (506) of the flange portion (500) via the holding plate (16). Firmly sandwiched between. As a result, the main body (501) is fixed to the flange (500).

Therefore, it is not necessary to form a screw insertion hole (508) for the screw (6) in the main body (501) in order to fix the main body (501) to the flange (500). When the rotary cylinder (5) is formed, the cutting of the plurality of screw insertion holes (508) becomes unnecessary, and the number of processing steps is reduced and the cost is reduced accordingly. In the case of forming by a molding method, it is not necessary to form a pin for forming the screw insertion hole (508) in the mold, and the structure of the mold is simplified and the cost is reduced. In addition, when the screw insertion hole (508) is formed, no weld is generated around the screw insertion hole (508).
1) The accuracy of the rotary cylinder (5) is improved.
In addition, the main body (501) caused by the tightening of the screw (6)
And the precision of the rotary cylinder (5) is further improved. Moreover, a plurality of screws (6) become unnecessary, and the effect of reducing the number of parts can be obtained.

(14A) is a relay board corresponding to the conventional (14), which is mounted on the upper surface of the rotary rotary transformer (902), and a pattern (141) is printed on the relay board (14A). Have been. (18) is a signal line connecting the magnetic head (7) to one end of the pattern (141), and the other end of each pattern (141) is connected by a signal line (15).
It is connected to the rotation rotary transformer (902). The magnetic head (7) is fixed to the flange (500).

Thus, the magnetic head (7) is connected to the relay board (14A) on the rotary rotary transformer (902) by the signal line (18).
By connecting directly to the relay board (11) on the upper surface of the rotary cylinder (5) and the signal lines (12),
(13) becomes unnecessary, and therefore these signal lines (1
Holes (510) and (511) for passing 2) and (13) are also unnecessary,
When the rotary cylinder (5) is formed by a cutting method,
Cutting of the holes (510) and (511) becomes unnecessary, so that the number of processing steps is reduced and the cost is further reduced. In the case of forming by a molding method, holes (510), (5
In the case where the holes (510) and (511) are formed, it is not necessary to form the pins for forming (11) in the mold, thereby simplifying the structure of the mold and reducing the cost. In addition, the generation of welds around the periphery is also eliminated, and the accuracy of the rotary cylinder (5) is further improved. Moreover, since the relay board (11) and the signal lines (12) and (13) become unnecessary,
The number of parts is reduced, and the cost is further reduced. However, such a configuration does not directly relate to the present invention, and the relay boards (11) and (14) may be arranged in the same manner as the conventional one as shown in FIG.

The main part of another embodiment of the present invention is shown in a longitudinal sectional view in FIG. This embodiment differs from the embodiment of FIGS. 1 and 2 in that the holding plate (16) is omitted and the main body (50) is omitted.
The diameter of the central through-opening (504) of 1) is reduced, and as a fastening member, it is directly locked to the peripheral portion (505) of the central through-opening (504) of the main body (501) instead of the screw (17). A pin (17A) having a head (173) and an unthreaded shaft (174) is used, and the center shaft (3) is threaded instead of the threaded hole (301). A hole (303) is formed, and the shaft (174) of the pin (17A) is fixed to the hole (303) by appropriate means such as press-fitting or shrink fitting. The same effect as that of the embodiment shown in FIGS. 1 and 2 can be obtained.

The main part of still another embodiment of the present invention is shown in a longitudinal sectional view in FIG. This embodiment is different from the embodiment shown in FIG. 3 in that a projection (503) for positioning a flange portion (500) is used.
Instead of omitting the opening (504) in the center of the body (501)
The diameter of the main body (5) is made substantially the same as the diameter of the central axis (3), and the central through-opening (504) is fitted to the central axis (3).
01) is that the positioning in the radial direction is performed. That is, it is possible to fit the center through-opening (504) for positioning in the radial direction by the projection (503) or the center axis (3) as in this embodiment. What is necessary is just the center part of the support part which consists of a center axis (3) and a flange part (500). In this embodiment, the positioning of the main body (501) in the axial direction is performed by the receiving surface (506) formed on the flange (500) as in the case of FIG.
Has gone by.

The main part of a further embodiment of the invention is shown in longitudinal section in FIG. This embodiment differs from any of the embodiments shown in FIGS. 1 to 4 in that a step is formed in a portion of the central shaft (3) protruding from the flange (500), and this step is formed. A receiving surface (304) for receiving a peripheral portion (505) of the central through opening (504) of the main body (501) is provided, and the diameter of the central through opening (504) of the main body (501) is smaller on the tip side than the step. The diameter of the central portion (504) is made substantially equal to the diameter of the central portion, and the center through opening (504) is fitted to this small diameter portion so that the receiving surface (304) formed on the central axis (3) positions the main body (501) in the axial direction. That is the point That is, the axial bearing surface for the peripheral portion (505) may be formed on either the central shaft (3) or the flange portion (500) constituting the support portion. The positioning of the main body (501) in the radial direction is performed at the small-diameter portion of the central axis (3).

In any of the above embodiments, the main body (50
The center through-opening (504) of 1) is formed to have a constant diameter in the thickness direction, but depending on the mounting structure to the supporting portion, the sixth through-hole may be formed.
As shown in the figure, it may be formed as a through opening whose diameter changes in the middle in the thickness direction.

It is needless to say that the present invention is not limited to the case where the rotary cylinder is formed by a cutting method or a forming method, but can be applied to a method formed by any other method.

〔The invention's effect〕

As described above, according to the present invention, an axial hole is formed at the end of the central shaft, and the head of the fastening member fixed to the axial hole and the receiving surface formed at the support portion are formed. With a very simple configuration in which the peripheral portion of the central through opening of the main body is sandwiched between the two, a rotary head assembly of a magnetic recording / reproducing apparatus having a rotary cylinder having a predetermined accuracy at a lower cost than the conventional one can be obtained. The effect is achieved.

[Brief description of the drawings]

FIG. 1 is a plan view showing a rotary cylinder of a rotary head assembly of a magnetic recording / reproducing apparatus according to an embodiment of the present invention as seen through a main body thereof, and FIG. 2 is a view taken along line II-II of FIG. 3 to 5 are longitudinal sectional views of main parts of different embodiments of the present invention, FIG. 6 is a view showing a modification of the main body of the rotary cylinder, and FIG. 7 is a conventional magnetic recording. FIG. 8 is a sectional view taken along line VIII-VIII in FIG. 7 of the rotary head assembly of the reproducing apparatus. In the figure, (1) is a magnetic tape, (2) is a fixed cylinder, (202) is an outer peripheral surface, (3) is a central axis, (301),
(303) is an axial hole, (302) is an end of the central axis (3),
(304) is a bearing surface, (4) is a bearing, (5) is a rotary cylinder, (500) is its flange, (501) is a main body, (50)
2) is the center through hole, (504) is the center through opening, (505) is the periphery of the center through opening (504) of the main body (501), (50)
6) is the receiving surface, (507) is the outer peripheral surface, (7) is the magnetic head,
(17) and (17A) are fastening members, and (172) and (173) are their heads. In the drawings, the same reference numerals indicate the same or corresponding parts.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-147115 (JP, A) JP-A-62-205514 (JP, A) JP-A-49-10709 (JP, A) JP-A-46-147 8511 (JP, A) Japanese Utility Model 63-49611 (JP, U) (58) Field surveyed (Int. Cl. ⁶ , DB name) G11B 5/52

Claims (1)

(57) [Claims] 1. A rotary head assembly for a magnetic recording / reproducing apparatus for recording / reproducing information on / from a magnetic tape, comprising: a fixed cylinder having an outer peripheral surface for guiding the running of the magnetic tape; A center axis designated as possible, and a rotating cylinder fixed to the center axis and supporting a magnetic head for recording and reproducing information on and from the magnetic tape, wherein the rotating cylinder has a center through hole fixed to the center axis. And a central through-opening in which a central portion of the support portion including the central shaft and the flange portion is fitted, and an outer peripheral surface around which the magnetic tape is wound, and is fixed and supported by the support portion. A rotary head assembly for a magnetic recording / reproducing apparatus comprising a main body, wherein the support has an axial receiving surface for receiving a peripheral portion of a central through-opening of the main body; An axial hole is formed at the end of the mandrel on the side of the rotating cylinder, and a fastening member having a head that is locked to a peripheral portion of a center through opening of the main body portion is formed in the axial hole of the central shaft. A rotary head assembly of a magnetic recording / reproducing apparatus, wherein a peripheral portion of a central through-opening of the main body is sandwiched between the head and the receiving surface.