JPS61224116A - Dynamic damper device - Google Patents

Abstract

PURPOSE:To promote miniaturization with a simple constitution and to contribute to improvement of the maintenability and its handling of a cylinder mechanism by providing an elastic body fitted to a rotating body and a weight member fitting freely and movably to the rotating body fitted to the elastic body. CONSTITUTION:The weight member 21 is fitted to one end of the elastic body 20 in a dynamic damper 19 which is fitted to a recess 22 for incorporation formed to a rotating disc 15. The elastic body 20 is buried in the press fit with a prescribed pressing force to the recess 22 and the weight member 21 is buried in the free fitting state freely and movably to the recess 22 with a prescribed gap 23. The weight member 21 fitted freely to the recess 22 of the rotating disc 15 is resonated in the recess 22 in interlocking with the rotation of the disc 15 through the drive of a cylinder mechanism 11. Then the weight member 21 attenuates the vibration of the disc 15 attended with the vibration due to rotation so as to prevent the resonance of the cylinder mechanism 11.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a dynamic damper used to damp vibrations of a rotating body in a cylinder mechanism installed in a magnetic recording/reproducing device such as a video tape recorder (VTR). (vibration absorber) device.

[Technical Background of the Invention II] It is generally known that in a VTR, if a resonance phenomenon exists in the cylinder mechanism, jitter on the screen will worsen, causing color unevenness, distortion, etc. on the screen. By the way, this resonance phenomenon occurs when the harmonics given by the motor torque ripple component in the cylinder mechanism and the vibration frequency component when the magnetic head runs on the tape match or become close to the natural frequency of the cylinder mechanism. , especially in the current 1/2 inch VTR.
This becomes a problem when promoting miniaturization of 8mm VTRs, etc., which are configured to be approximately half the size of the 8mm VTR. For this reason, traditionally,
It was thought that a dynamic damper device could be installed in the cylinder mechanism to dampen the vibrations of the rotating body and improve screen jitter.

Figure 2 shows the above dynamic damper device.
An elastic body 4 to which a weight member 3 is attached is attached to the upper surface of a rotating disk 2 rotatably supported via a rotating shaft 1 by a fixed cylinder (not shown) using a plate 5 and screws 6. However, the vibration of the rotating disk 2 is damped by the weight member 3 and the elastic body 4.

Further, 7 in the figure is a magnetic head.

[Problems in the Background Art] However, in the dynamic damper device described above, due to its configuration, the rotating disk 2, the magnetic head 7, etc. must be removed for maintenance and replacement, which makes the maintenance and replacement work difficult. In addition to being very complicated, there is a problem in that the mounting accuracy of the magnetic head 7 varies depending on the amount of tightening of the screw 6 during the mounting. Furthermore, this has the problem that due to its configuration, the cylinder mechanism becomes large in the axial direction, making it unsuitable for the recent demand for downsizing.

[Object of the invention] This invention has been made in view of the above circumstances, and has a simple configuration,
Moreover, it is an object of the present invention to provide a dynamic damper device that can promote miniaturization and contribute to improved maintainability and handling of the cylinder mechanism.

[Summary of the invention! ! ] That is, the present invention includes an elastic body fitted and embedded in a rotating body, and a weight member that is embedded in a loosely fitted state movable with respect to the rotating body attached to the elastic body. The intended purpose is achieved by incorporating a built-in rotor and configuring the rotor to damp vibrations of the rotating body.

[Embodiments of the Invention] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a dynamic damper device according to an embodiment of the present invention. In the figure, reference numeral 10 denotes a fixed cylinder constituting a cylinder mechanism 11, in which a rotating shaft 12 is freely rotatable via a bearing 13 and a spring member 14. provided. This rotating shaft 12 is connected to a rotating mechanism (not shown) at one end thereof,
A rotating disk 15 is attached to the other end with a flange 16 interposed therebetween. A magnetic head 18 is mounted on the lower surface of the rotating disk 15 and is electrically connected to an 8Is device (not shown) via a rotary transformer mechanism 17, and a dynamic damper 19 is mounted on the upper surface of the rotary disk 15 on the rotating shaft. It is buried approximately symmetrically. These dynamic dampers 19 are similar to each other, for example, a cylindrical elastic body 2.
A weight member 21 is fitted to one end of the rotary disk 15, and is inserted into a built-in recess 22 formed in the rotary disk 15 and shaped like a gourd, for example. Among these, the elastic body 20 is press-fitted into the recess 22 with a predetermined press-fitting strength, and one weight member 21 is inserted into the recess 8I! 2'2 with a predetermined gap 23 and is movably loosely fitted.

In the above configuration, when the cylinder mechanism 11 is driven and the rotating disk 15 rotates, the weight member 21 loosely fitted into the recess 22 of the rotating disk 15 vibrates (resonates) within the recess 22 in conjunction with the rotation. Ru. Thus, the weight member 21 damps the vibration of the rotary disk 15 due to the vibration caused by its rotational drive, thereby preventing the resonance phenomenon of the cylinder mechanism 11 from occurring.

In this manner, the dynamic damper device is embedded in the rotating disk 15 with the elastic body 20 fitted therein, and is embedded in the elastic body 20 in a loosely fitted state so as to be movable relative to the rotating disk 15. Since the weight member 21 is fitted and built into the rotating disk 15, due to its structure, the magnetic head 18 and the rotating disk 1 are
A device that does not get in the way during the maintenance/replacement work in step 5, which can promote improvement in maintainability and handling of the cylinder mechanism 11, and can promote improvement in the thinning of the cylinder mechanism 11 as much as possible. It is.

Further, in the above embodiment, this invention has been explained in the case where two locations are provided on the rotating disk 15, but by adjusting the strength (hardness) of the elastic body 20 and the weight of the weight member 21, it is possible to increase the number of locations. However, the present invention is not limited to this, and is applicable. For example, by providing a plurality of locations, it is possible to attenuate a plurality of frequency components.

Furthermore, in the above embodiment, the cylinder mechanism 1 has a two-layer structure in which a rotary disk 15 is rotatably provided on a fixed cylinder 10.
Although the present invention has been described with reference to the case where it is applied to No. 1, the present invention is not limited thereto, and substantially the same effects can be expected even when applied to a cylinder mechanism with a 311 structure consisting of an upper cylinder, a rotating cylinder, and a lower cylinder.

Note that this invention is not limited to the above embodiments, but also includes
It goes without saying that various modifications can be made without departing from the spirit of the invention.

[Effects of the Invention] As described in detail above, the present invention has a simple configuration, can promote miniaturization, and can contribute to improved maintainability and ease of handling of the cylinder mechanism. A dynamic damper device can be provided.

[Brief explanation of the drawing]

FIG. 1 is a structural explanatory diagram showing a dynamic damper device according to an embodiment of the present invention, and FIG. 2 is a structural explanatory diagram showing a conventional dynamic damper device. DESCRIPTION OF SYMBOLS 10... Fixed cylinder, 11... Cylinder mechanism, 12... Rotating shaft, 13... Bearing, 14... Spring member, 15... Rotating disk, 16... 7 lange, 17... ...Rotary transformer mechanism, 18...Magnetic head, 19...Dynamic damper, 20...
Elastic body, 21... Weight member, 22... Recess, 2
3... Gap. Applicant's agent Patent attorney Takehiko Suzue Figure 1 (a) Figure 2 (a) (b)

Claims (1)

[Claims] In a dynamic damper device that damps vibrations of a rotating body in a cylinder mechanism of a magnetic recording and reproducing device,
A dynamic damper device comprising: an elastic body fitted to the rotating body; and a weight member fitted to the elastic body and movably loosely fitted to the rotating body.