JP2804482B2 - Cylinder mounting device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylinder mounting device for mounting a rotary cylinder device equipped with a magnetic head in a helical scan type magnetic recording / reproducing device.

[Prior Art] In a home VTR, as shown in FIG. 4, a rotary cylinder device 1 is provided at a predetermined angle with respect to a main chassis 3, and is provided on a guide base in a recording / reproducing mode. The magnetic tape 9 is pulled out from the tape cassette 6 by the guide rollers 7, 8 and the like, and is spirally wound around the outer peripheral surface of the rotary cylinder device 1 at a predetermined angle to form a tape running path. The rotary cylinder of the rotary cylinder device 1 is provided with a magnetic head (not shown), and the rotary cylinder rotates as the magnetic tape 9 travels, so that recording and reproduction of signals on the magnetic tape 9 by the magnetic head are performed.

The rotary cylinder device 1 is mounted on a cylinder mount 2 attached to a main chassis 3. The structure of the cylinder mount 2 causes the rotary cylinder device 1 to be inclined at a predetermined angle with respect to the main chassis 3.

FIG. 5 shows a method of attaching the rotary cylinder device 1 to the main chassis 3.

In the figure, the main chassis 3 has a large notch hole.
3A is provided, and three screw holes 3B to 3D are provided around the notch hole 3A. On the other hand, the cylinder mount 2 also has a large mounting hole 2A in the center,
And two through holes 2B to 2D and three through holes 2E to 2G. The cylinder mount 2 is arranged such that the through holes 2B, 2C, and 2D correspond to the screw holes 3B, 3C, and 3D of the main chassis 3, respectively.
The screws 4 are placed on the main chassis 3 and the through holes 2
It is fixed to the main chassis 3 by being screwed into the screw holes 3B, 3C, 3D through B, 2C, 2D and tightened. When the cylinder mounting base 2 is fixed to the main chassis 3 in this manner, the mounting holes 2A of the cylinder mounting base 2 and the main chassis 3
The notch 3A is continued.

The rotary cylinder device 1 includes a rotary cylinder 1A equipped with a magnetic head, a fixed cylinder 1B provided with an inclined tape lead 1D, and a protruding portion 1C formed by a built-in drive motor. The diameter is smaller than 1B. Although not shown, screw holes corresponding to the through holes 2E, 2F, and 2G of the cylinder mount 2 are provided on the bottom surface of the fixed cylinder 1B.

The rotary cylinder device 1 is arranged such that the bottom surface of the fixed cylinder 1B rests on the top surface of the mounting seat formed on the cylinder mounting base 2, that is, the mounting surface 2H, on the cylinder mounting base 2 fixed to the main chassis 3. And placed. Here, the through holes 2E to 2G of the cylinder mounting base 2 are provided on the mounting surface 2H, respectively.
, These through holes 2E to 2G face the notch holes 3A of the main chassis 3. The respective screw holes on the bottom surface of the fixed cylinder 1B of the rotary cylinder device 1 are aligned with the through holes 2E to 2G of the cylinder mount 2, and then the screws 5 are inserted through the respective through holes 2E to 2G from the back side of the cylinder mount 2. The rotary cylinder device 1 is screwed and fixed to the cylinder mounting device 2 by tightening into the respective screw holes on the bottom surface of the fixed cylinder 1B.

Here, the plane including each mounting surface 2H of the cylinder mounting base 2 is inclined at a predetermined angle with respect to the main chassis 3 when it is fixed to the main chassis 3, so that the rotary cylinder device 1 When fixed to the base 2 by screwing, the rotary cylinder device 1 is inclined at a predetermined angle with respect to the main chassis 3 as described above.

[Problems to be Solved by the Invention] On the other hand, when the cylinder mount 2 is attached to the main chassis 3, the entire back surface of the cylinder mount 2 is not in contact with the surface of the main chassis 3. On the back surface of the cylinder mounting base 2, mounting seats are formed so as to protrude around the through holes 2 B, 2 C, 2 D, and the top surfaces of these mounting seats contact the surface of the main chassis 3.

Incidentally, the top surfaces of these mounting seats are ideally on the same plane with zero flatness (that is, the flatness of the mounting seat is ideally zero), and the flatness of the main chassis 3 is ideally zero. If zero, the cylinder mount 2 will be mounted on the main chassis 3 in the correct state and posture,
This is practically impossible, and there is a problem with at least either the top surface of the mounting seat of the cylinder mounting base 2 or the flatness of the main chassis 3. Therefore, the cylinder mount 2
If these are screwed and fixed to the main chassis 3, one of them will be distorted and deformed. Normally, the main chassis 3 is stronger than the cylinder mount 2, so that the cylinder mount 2 is more deformed.

This will be described with reference to FIG. 6, which shows a portion between the screw through holes 2B and 2C of the cylinder mount 2 mounted on the main chassis 3. Here, it is assumed that the main chassis 3 is bent in a convex shape from the rear surface side to the front surface side. On the back surface of the cylinder mount 2, convex mounting seats 13B and 13C are provided around the through holes 2B and 2C. Align the through holes 2B, 2C with the screw holes 3B, 3C of the main chassis 3, and insert the screw 4 through the through hole 2B.
When tightened to B, the entire top surface of the mounting seat 13B is tightened so as to contact the surface of the main chassis 3, so that the through hole
On the 2C side, the mounting seat 13C floats from the surface of the main chassis 3, and the screw 4 is passed through the through hole 2C to form a screw hole 3C.
To the mounting seat in the through hole 2B side.
13B will float from the surface of the main chassis 3. Then, when the screw 4 is tightened into the screw holes 3B, 3C through the through holes 2B, 2C, the main chassis 3 has a large mechanical strength, so that the deformation occurs between the through holes 2B, 2C in the cylinder mount 2 side. Become.

As described with reference to FIG. 5, when the rotary cylinder device 1 is screwed and fixed to the cylinder mounting base 2 thus deformed, the rotary cylinder device 1, particularly the fixed cylinder 1B
Is deformed, and accordingly, the tape lead 1D formed thereon is also deformed. If the tape lead 1D is deformed, the running of the magnetic tape guided by the deformation will be disturbed, and the reproduced output waveform of the magnetic head will be disturbed as shown in FIGS. Not preferred.

From the above, in the past, very high precision was required for the flatness of the main chassis and the mounting seat of the cylinder mounting base, and these were troublesome and expensive to manufacture. There was.

SUMMARY OF THE INVENTION An object of the present invention is to provide a cylinder mounting device that solves such a problem and can reduce the accuracy of flatness of a main chassis or a mounting seat of a cylinder mounting base.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a method for mounting a cylinder on a cylinder mounting base on each of screw through holes for mounting to a main chassis on a back surface of the cylinder mounting base. The cylinder mounting base on the mounting side is also provided with a projection having a substantially point-like apex near each of the screw holes for mounting.

Further, the present invention relates to the screw through hole or the screw hole, and locates the convex portion on a side substantially opposite to the mounted rotary cylinder device.

[Operation] When the cylinder mount is screwed and fixed to the main chassis, since the convex portion is provided close to the screw through hole or the screw hole, the contact portion between the cylinder mount and the main chassis is It mainly becomes the top of the projection. Since the top portion is substantially point-shaped, the cylinder mounting base and the main chassis are supported at three points by almost point contact, and even if the accuracy of the flatness is relatively low, the flatness is reduced. Therefore, the mounting state and mounting posture of the cylinder mounting base to the main chassis are hardly affected, and therefore, the deformation of the cylinder mounting base can be prevented.

Also, when the convex portion is positioned on the substantially opposite side to the rotary cylinder device with respect to the screw through hole or the screw hole, the cylinder mounting base presses against the main chassis side when the cylinder mounting base is screwed to the main chassis. Such a force acts, and the positional relation of the mounting surface of the rotary cylinder device on the cylinder mount to the surface of the main chassis is fixed. Accordingly, the attitude of the rotary cylinder device with respect to the main chassis, such as the inclination angle, becomes constant.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a cylinder mounting base in an embodiment of a cylinder mounting device according to the present invention, wherein FIG. 1 (a) is a plan view as viewed from the front side, and FIG. 1 (b) is a plan view as viewed from the back side. 10B, 10C, and 10D are convex portions, and portions corresponding to the above-described drawings are denoted by the same reference numerals, and redundant description will be omitted.

In FIGS. 1 (a) and 1 (b), on the back surface of the cylinder mount 2 (the surface facing the main chassis), there are screw through holes 2B for screwing the cylinder mount 3 to the main chassis. Close to 2C and 2D, respectively, convex part 10
B, 10C and 10D are provided. Here, similarly to the prior art described above, annular mounting seats 13B, 13C, 13R protruding around the respective screw through holes 2B, 2C, 2D on the back surface of the cylinder mounting base 2.
D is provided, but the projections 10B, 10C, 10D
It is provided on the top surface of 13B, 13C, 13D, and is positioned substantially opposite to the rotary cylinder device (not shown) with respect to the screw through holes 2B, 2C, 2D. In the drawing, the center O of this rotary cylinder device and the screw through holes 2B, 2
Each convex part on a straight line (dash-dot line) connecting the center of C and 2D
There are 10B, 10C, and 10D.

However, these projections 10B, 10C, and 10D do not need to be strictly positioned on these dashed lines, and it is not necessary to provide mounting seats 13B, 13C, and 13D for each of the screw through holes 2B, 2C, and 2D. The portions 10B, 10C, and 10D may be provided directly on the back surface of the cylinder mount 2.

The protrusions 10B, 10C, and 10D have a substantially dot-like top, and when the cylinder mount 2 is placed on the main chassis, the cylinder mount 2 is moved to the convex portions 10B, 10C, and 10D.
The main chassis is supported at three points by substantially point contact with the top of the 10D.

Then, when such a cylinder mounting base 2 is placed on the main chassis, the cylinder mounting base 2 has a projection on the main chassis.
In this state, almost point contact is made at 10B, 10C, and 10D, and in this state, the attitude of the cylinder mount 2 with respect to the main chassis is determined. In other words, this attitude is determined by the relationship between the contact points of the projections 10B, 10C, and 10D on the surface of the main chassis.

In this state, even if the screw is tightened into the screw hole of the main chassis through each screw through hole 2B, 2C, 2D, the protrusion 10
B, 10C, and 10D are in point contact with the main chassis, and the contact state does not change, and convex portions 10B, 10C, and 10C on the surface of the main chassis.
Since the relationship between the 10D contact points does not change, the cylinder mount 2 is screwed and fixed to the main chassis while maintaining the posture before screwing. Therefore, even if the accuracy of the flatness of the main chassis is relatively low, the cylinder mount 2 does not deform when it is screwed and fixed to the main chassis.

This will be described with reference to FIG. 2 for the portion between the screw through-holes 2B and 2C. As shown in FIG. 6, the cylinder of this embodiment is provided with a main chassis 3 which is deformed so as to project from the back side to the front side. When the mounting base 2 is mounted, the cylinder mounting base 2 is provided with the convex portions 10B, 1 near the screw through holes 2B, 2C.
Point contact is made so that 0C is in contact with the surface of the main chassis 3 (similarly, the convex portion 10D close to the screw through hole 2D is not shown). Therefore, the attitude of the cylinder mount 2 with respect to the main chassis 3 at this time is determined by the relationship between the contact points of the projections 10B, 10C, and 10D on the main chassis 3.

Then, when the cylinder mounting base 2 is tightened to the main chassis 3 with the screw 4, the protrusions 10 on the main chassis 3 are formed.
The relationship between the contact points of B and 10C does not change, and these convex portions 10B and 10C
Since the contact point does not change due to point contact with the main chassis 3, the posture of the cylinder mount 2 does not change even after screwing to the main chassis 3.

When the projections 10B, 10C, and 10D are positioned on the opposite side of the center O of the rotary cylinder device with respect to the screw through holes 2B, 2C, and 2D as shown in FIG. 1, the cylinder mount 2 is screwed into the main chassis. When the stopper is fixed, a force acts on the cylinder mounting base 2 against the main chassis with the projections 10B, 10C, and 10D as fulcrums. For this purpose, screw through holes 2B, 2C,
Even if the cylinder mount 2 is tightened with screws in 2D order,
When tightening the screw with the screw through hole 2B, the cylinder mount 2 is urged toward the main chassis, so the convex
10C and 10D abut the main chassis, and then the screw through hole 2
Similarly, when tightening the screw with C,
Is in contact with the main chassis. In this manner, even when the screw is being tightened, the cylinder mount 2 does not change its posture, and thus does not deform.

In the case of a conventional cylinder mounting base provided with only mounting seats, if the accuracy of the main chassis and the flatness of these mounting seats is low, when the cylinder mounting base is mounted on the main chassis,
It is impossible that all the mounting seats contact the main chassis on the entire top surface, and when the cylinder mounting base is screwed and fixed to the main chassis, as shown in FIG. The whole surface comes into contact with the main chassis. For this reason, the inclination of the top surface of each mounting seat differs from each other, and as a result, the cylinder mounting base is deformed.

Of course, as shown in FIG. 1 (a), each of the projections 10B, 10C, and 10D is not required to be on the dashed line, and the screw through holes 2B, 2C, and 2D
The same operation and effect as described above can be obtained as long as the rotary cylinder device is mounted on a side substantially opposite to the mounted rotary cylinder device.

As described above, in this embodiment, the cylinder mount 2
Is not deformed even if it is screwed and fixed to the main chassis 3, so that there is no deformation in the rotary cylinder device, especially the fixed cylinder, which is mounted on the cylinder mount 2 as shown in FIG. The running of the magnetic tape in the apparatus can be made smooth, and a head reproduction output having a stable waveform can be obtained as shown in FIG.

In the above embodiment, the protrusions are provided on the cylinder mount. However, similar protrusions are provided near the mounting screw holes (screw holes 3B, 3C, 3D in FIG. 5) of the cylinder mount in the main chassis. May be provided, and the same operation and effect as described above can be obtained.

[Effects of the Invention] As described above, according to the present invention, the cylinder mount can be fixed to the main chassis with screws while maintaining the posture when the cylinder mount is placed on the main chassis. Can prevent deformation of the cylinder mount due to the above, and even if the tolerance of parts accuracy such as main chassis is expanded to some extent, tape running in the rotary cylinder device can be stabilized, resulting in cost reduction and quality of parts. Labor reduction such as management can be achieved.

[Brief description of the drawings]

FIG. 1 (a) is a plan view of a cylinder mounting base in one embodiment of the cylinder mounting apparatus according to the present invention as viewed from the front side, FIG. 1 (b) is a plan view of the same viewed from the back side, and FIG. FIG. 3 is a cross-sectional view showing the mounting state of the table to the main chassis, FIG. 3 is a waveform diagram showing head playback output according to this embodiment, FIG. 4 is a plan view showing a tape running mechanism of a home VTR, and FIG. FIG. 6 shows a method of mounting a rotary cylinder device on a main chassis by a cylinder mounting device, FIG. 6 is a cross-sectional view showing a mounting state of a rotary cylinder device on a main chassis by a conventional cylinder mounting device, and FIG. 7 shows a deformed cylinder mounting base. FIG. 9 is a waveform diagram showing a head reproduction output when the operation is performed. 2 ... Cylinder mount, 2B, 2C, 2D ... Screw through hole, 2H ...
... the mounting surface of the rotary cylinder device, 3 ... the main chassis,
3B, 3C, 3D: Screw hole, 4: Screw, 10B, 10C, 10D: Protrusion.

──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Yasuhiro Hashiguchi 1410 Inada, Katsuta, Ibaraki Prefecture Inside Tokai Plant, Hitachi, Ltd. (72) Koji Fukuda 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture (56) References JP-A-62-54887 (JP, A) JP-A-60-182087 (JP, A) JP-A-63-96695 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) G11B 15/61 G11B 33/12

Claims (2)

(57) [Claims] A plurality of screw through holes are provided in a cylinder mounting base to which a rotary cylinder device is screwed and fixed, and a screw hole facing the screw through hole is provided in a main chassis. In a cylinder mounting device in which the cylinder mounting base is screwed and fixed to the main chassis by tightening a screw into the screw hole through each, a surface of the cylinder mounting base opposed to the main chassis includes:
A protruding portion having a substantially point-like apex is provided for each of the screw through holes in proximity to the screw through hole, and each of the convex portions is further mounted on the cylinder mount with respect to the screw through hole. A cylinder mounting device, which is arranged on a side opposite to a side of the rotary cylinder device to be placed. 2. A plurality of screw through-holes are provided in a cylinder mounting base to which a rotary cylinder device is screwed and fixed, and a screw hole facing the screw through-hole is provided in a main chassis. In the cylinder mounting device, the cylinder mounting base is screwed and fixed to the main chassis by tightening a screw into the screw hole through each of the screw holes. On a surface of the main chassis opposed to the cylinder mounting base,
Each of the screw holes is provided with a convex portion having a substantially point-like apex in proximity to the screw hole, and each of the convex portions is further mounted on the cylinder mount with respect to the screw hole. A cylinder mounting device, which is disposed on a side opposite to a side of the rotary cylinder device mounted on a main chassis.