JP2006185496A - Dynamic vibration absorber and optical disk device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dynamic vibration absorber capable of absorbing vibration of small to large energy even during high-speed rotation, and an optical disk device using the same. <P>SOLUTION: The dynamic vibration absorber is held on a main chassis 12 for supporting a motor to drive an optical disk. A casing 11, the main chassis 12, and the dynamic vibration absorber 13 are held by an integrated elastic body 20, and the projected part 14 of the dynamic vibration absorber 13 constituting the dynamic vibration absorber is fitted to the top of the through-hole 21 of the elastic body 20. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a dynamic vibration absorber and an optical disk device using the same, and more particularly to a dynamic vibration absorber capable of absorbing vibration during high-speed rotation and an optical disk device using the same.

  An optical disc apparatus for driving an optical medium such as an optical disc such as a CD, CD-ROM, DVD, DVD-ROM, magneto-optical disc, or large capacity FD is disclosed in, for example, Japanese Patent Application Laid-Open No. 2004-192781 (Patent Document 1). Yes. FIG. 10 is a perspective view showing a main part of the optical disc apparatus disclosed in Patent Document 1. In FIG.

  Referring to FIG. 10, a conventional optical disc apparatus is a main unit mounted via elastic body 114 at four locations of casing 111 (only a part of the casing is shown in FIG. 10) and casing 111. A chassis 112 and a dynamic vibration absorber (counterweight) 113 are included. A spindle motor 121 for rotating a disk (not shown) is provided on the main chassis 112, and an optical pickup (not shown) for reading data from the disk is attached to the optical pickup holder 122. Here, the dynamic vibration absorber 113 and the elastic body 114 constitute a dynamic vibration absorber.

  FIG. 11 is a diagram showing a configuration of the elastic body 114 shown in FIG. As shown in FIG. 11, the elastic body 114 includes a first elastic body portion 114 e that supports the casing 111 and the main chassis 112, and a second elastic body portion 114 f that the main chassis 112 supports the dynamic vibration absorber 113. Because of the integrated configuration, the number of parts can be reduced and the configuration is simplified as compared with the case of supporting the casing 111 and the main chassis 112 and the main chassis 112 and the dynamic vibration absorber 113 individually. Note that the elastic coefficients k1 and k2 are set such that the material and dimensions of the elastic body are k1 <k2.

Further, the elastic body 114 has a cylindrical shape having three recesses 114a, 114b, and 114c on the outer periphery that serve as support portions for supporting the casing, the main chassis, and the dynamic vibration absorber. Is provided.
JP 2004-192781 A (FIG. 1 and related description)

  In the optical disk apparatus using the dynamic vibration absorber shown in FIG. 11 and supported by the elastic body 114 in which the first elastic body portion 114e and the second elastic body portion 114f are integrated, the rotational speed of the disk is about 8000 RPM. Then, vibration was sufficiently absorbed with the above configuration.

  On the other hand, recently, the speed of the optical disk apparatus has been increased, and the rotation speed of the spindle motor has become about 10,000 RPM. In order to cope with this, it is necessary to increase the thickness of the portion of the elastic body 114 that supports the casing 111, the main chassis 112, and the dynamic vibration absorber 113 so that the effect can be obtained at a higher rotational speed.

  FIG. 12 shows measurement results obtained by measuring internal vibration using the eccentric gravity center disk in the optical disk apparatus having the dynamic vibration absorber adjusted as described above. The horizontal axis represents the number of rotations (RPM), and the vertical axis represents the magnitude of vibration in terms of (G-rms: root mean square of acceleration).

  (A) is the case where the amount of eccentric gravity is 1 g-cm, and (B) is the case where the amount of eccentric gravity is 0.5 g-cm. In the figure, ▲ is a case where a dynamic vibration absorber made up of the dynamic vibration absorber 113 and the elastic body 114 is not provided, and ■ is data when a dynamic vibration absorber is provided.

  Referring to FIGS. 12A and 12B, when the amount of eccentric gravity is large (when vibration energy is large and 1 g-cm) when the number of rotation exceeds 9000 revolutions, There is a difference in the magnitude of vibration and the effect of a dynamic vibration absorber, but there is little difference between the two when the eccentric mass is small (in the case of 0.5 g-cm). The effect of is not demonstrated. This eliminates the meaning of providing a dynamic vibration absorber.

  The present invention has been made to solve the above problems, and a dynamic vibration absorber capable of absorbing small to large vibrations regardless of the amount of eccentric gravity even at high speed rotation such as 10,000 RPM, and the same An object of the present invention is to provide an optical disk apparatus using the above-described optical disk device.

  In the dynamic vibration absorber held by the main chassis that supports the motor for driving the optical disk according to the present invention, the main chassis is held by the housing via the first elastic body and constitutes the dynamic vibration absorber. A second elastic body for supporting the child on the main chassis; The first elastic body and the second elastic body are integrated and include a rigid means for increasing the rigidity of the second elastic body.

  Since the first elastic body and the second elastic body are integrated and include rigidity means for increasing the rigidity of the second elastic body, the entire elastic body has a small amount of eccentric gravity, that is, even with a small excitation force. By reducing the rigidity so that the dynamic vibration absorber operates and increasing the rigidity of the second elastic body constituting the dynamic vibration absorber, it is possible to cope with high-speed rotation.

  As a result, it is possible to provide a dynamic vibration absorber capable of absorbing small to large vibrations regardless of the amount of eccentric gravity even at high speed rotation.

  Preferably, the second elastic body has a recess, the dynamic vibration absorber has a protrusion, and the rigid means includes a protrusion of the dynamic vibration absorber fitted in the recess of the second elastic body.

  Since the protrusion of the dynamic vibration absorber fits into the recess of the second elastic body, the overall height can be reduced.

  As a result, it is possible to provide a dynamic vibration absorber that can absorb vibrations at high speed rotation and is compact as a whole.

  The second elastic body may have a recess, and the rigid means may include a filler that fills the recess of the second elastic body.

  Preferably, the first elastic body has a hollow portion therein, the second elastic body includes a solid portion therein, and the rigid means is a solid portion inside the second elastic body.

  The first elastic body and the second elastic body may be made of the same material or different materials.

  In another configuration of the present invention, the dynamic vibration absorber is held by a main chassis that supports a motor that drives an optical disk. The main chassis is held in the housing via the first elastic body, and the dynamic vibration absorber is configured of a material different from the first elastic body, supporting the dynamic vibration absorber constituting the dynamic vibration absorber on the main chassis. Including the second elastic body, the first elastic body and the second elastic body are integrated, and includes a rigid means for increasing the rigidity of the second elastic body.

  An optical disk device according to the present invention is equipped with any of the above-described dynamic vibration absorbers.

  As a result, it is possible to provide an optical disc apparatus capable of absorbing small to large vibrations regardless of the eccentric mass of the disk even at high speed rotation.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing an embodiment of a dynamic vibration absorber according to the present invention and an optical disk apparatus using the same.

  Referring to FIG. 1, an optical disc apparatus 10 includes a housing 11 (only a part of the housing is shown in FIG. 1) and a main body attached via elastic bodies 20 at four locations of the housing 11. A chassis 12 and a dynamic vibration absorber 13 are included. The dynamic vibration absorber 13 and the upper part of the elastic body 20 constitute a dynamic vibration absorber.

  A spindle motor 31 for rotating a disk (not shown) is provided on the main chassis 12, and an optical pickup (not shown) for reading data from the disk is attached to an optical pickup holder 32.

  The optical pickup holder 32 is moved in the direction of the arrow in the drawing along a guide 33 provided at the lower part of the main chassis 12.

  2 is a cross-sectional view taken along II-II in FIG. Referring to FIG. 2, the casing 11, the main chassis 12, and the dynamic vibration absorber 13 of the optical disc apparatus 10 are supported by an integrated elastic body 20. The elastic body 20 has a cylindrical shape having a through-hole 21 inside and a recess supporting the casing 11 and the main chassis 12 on the outer periphery. The dynamic vibration absorber 13 has a protrusion 14 at a position where the elastic body 20 exists, and the protrusion 14 can be inserted into the top of the through hole 21.

  FIG. 3 is an enlarged view around one elastic body 20, indicated by III in FIG. With reference to FIG. 3, the engagement state between the protrusion 14 of the dynamic vibration absorber 13, the main chassis 12, the housing 11 and the elastic body 20 will be described.

  The elastic body 20 has a through-hole 21a with a small diameter and a through-hole 21b with a large diameter, and the dynamic vibration absorber 13 has a protrusion 14. At two locations in the axial direction of the elastic body 20, annular recesses 20a and 20b are formed on the outer periphery, supported by the casing 11 via the recess 20a, and supported by the main chassis 12 via the recess 20b.

  Further, the head portion of the protruding portion 14 spreads out in an umbrella shape in the radial direction and engages with the step portion 22 formed by the through holes 21a and 21b to prevent the elastic body 20 from coming off.

  For this purpose, the housing 11 is provided with a through hole 11a at a place where the elastic body 20 is attached, and the main chassis 12 is provided with a through hole 12a at a place where the elastic body 20 is attached. Further, the diameters of the through holes 11 a and 12 a are set to be smaller than the outer diameter of the elastic body 20.

  As described above, according to this embodiment, since the protrusion 14 of the dynamic vibration absorber 13 is inserted into the top of the elastic body 20, the lateral rigidity at the top of the elastic body 20 can be increased. Therefore, only the rigidity of the portion where the dynamic vibration absorber is formed can be increased without increasing the rigidity (hardness) of the entire elastic body 20. That is, the first elastic body portion 20c having the elastic coefficient k1 that supports the main chassis 12 and the second elastic body portion 20d having the elastic coefficient k2 that forms the dynamic vibration absorber are represented by the elastic coefficient k1 <k2. Thus, the rigidity of the second elastic body portion 20d can be set high while maintaining the first elastic body portion 20c so that the eccentric mass of the disk is small and vibrations with small excitation energy are also received. As a result, it is possible to easily match the natural frequency of the second elastic body portion with the rotational frequency in the 10,000 RPM region under a desired design condition, that is, at a high speed rotation such as 10,000 RPM. It is possible to provide a dynamic vibration absorber capable of absorbing vibrations up to and an optical disk device using the same.

  Further, in this embodiment, when the casing 11, the main chassis 12, and the dynamic vibration absorber 13 are arranged in this order from the bottom with respect to the elastic body 20, a protruding portion is formed on the dynamic vibration absorber 13. Therefore, the height of the dynamic vibration absorber can be reduced, and the height of the entire optical disc apparatus can be reduced. As a result, it is possible to provide a compact optical disc apparatus having a lower height.

  The elastic modulus is set as follows. A spindle motor 31 for rotating the disk is mounted on the main chassis 12, and the main chassis 12 is supported on the housing 11 by a first elastic body portion 20c having an elastic coefficient k1. On the other hand, an excitation force due to the eccentric rotation of the disk is applied to the main chassis 12. The mass and the elastic coefficient k2 of the dynamic vibration absorber 13 and the second elastic body portion 20d are set so as to coincide with the frequency of the excitation force. By setting in this way, the casing 11, the main chassis 12, and the dynamic vibration absorber 13 are supported by an elastic body made of the same material, and vibration can be effectively prevented.

  Next, FIG. 4 shows measurement results obtained by measuring internal vibration using the eccentric gravity center disk in the optical disk apparatus having the dynamic vibration absorber shown in FIG. This figure corresponds to FIG. 12, with the horizontal axis representing the number of revolutions (RPM) and the vertical axis representing the magnitude of vibration in G-rms. (A) is the case where the amount of eccentric gravity is 1 g-cm, and (B) is the case where the amount of eccentric gravity is 0.5 g-cm. In the figure, ▲ indicates a case where no dynamic vibration absorber is provided, and ■ indicates data when a dynamic vibration absorber is provided.

  Referring to FIG. 4, the dynamic vibration absorber is operated at a high rotation exceeding 8000 rotations even when the mass eccentricity is large (1 g-cm) and when the mass eccentricity is small (0.5 g-cm). It can be seen that there is a difference in the magnitude of vibration between the case where it is provided and the case where it is not provided, and the desired effect of the dynamic vibration absorber is obtained.

  Next, a modification of this embodiment will be described. FIG. 5 is a diagram showing a modification representing the same part as the part shown in FIG. Referring to FIG. 5, here, the elastic body having the conventional shape shown in FIG. 11, that is, a structure having the through hole 25 and supporting the dynamic vibration absorber 15 by a recess provided on the outer periphery of the elastic body 24. In the elastic body 24, the filler 26 is inserted into the top of the through hole 25. The filler 26 can increase the lateral rigidity of the second elastic body portion 24b constituting the dynamic vibration absorber.

  With this method, since an elastic body having a conventional configuration can be used, it is not necessary to manufacture a new mold or the like as shown in the previous embodiment.

  In addition, the filler can select the arbitrary materials which can obtain the desired characteristic of a dynamic vibration absorber, such as resin, a hard rubber, and a metal.

  Here, the filler is inserted into the elastic body 24 having the through-hole 25. However, the present invention is not limited thereto, and the first elastic body portion 24a is hollow as shown in this embodiment, and the second elastic body portion is formed. The elastic body 24 may be molded so that only the top 24b is solid.

  Next, a further modification of this embodiment will be described. FIG. 6 is a diagram showing a modification representing the same part as the part shown in FIG. Referring to FIG. 6, here, similarly to FIG. 5, an elastic body having a conventional shape, that is, a through hole 25, and the dynamic vibration absorber 15 is also supported by a recess provided on the outer periphery of the elastic body. In the elastic body 24, a dynamic vibration absorber 16 having a convex portion 16a, a connecting portion 16b for connecting the convex portion 16a and the dynamic vibration absorber 15 to the dynamic vibration absorber 15 shown in FIG. The convex portion 16 a of the dynamic vibration absorber 16 is inserted into the top of the through hole 25 of the elastic body 24. By this convex part 16a, the rigidity of the second elastic body part 16b can be made higher than the rigidity of the first elastic body part 16a constituting the dynamic vibration absorber.

  Next, another embodiment will be described. FIG. 7 is a diagram showing another embodiment of the present invention, and corresponds to the same part as FIG. In this embodiment, the positions of the housing 11 and the dynamic vibration absorber 13 are reversed with respect to the embodiment shown in FIG. Since the other parts are the same as those of the previous embodiment, the same reference numerals are assigned to the corresponding parts, and the description thereof is omitted. Also in this embodiment, since the configuration is just reversed, the same effect as the previous embodiment can be obtained.

  Next, a modification of this embodiment will be described. FIG. 8 is a diagram showing a modification of the embodiment shown in FIG. In this embodiment, the positions of the housing 11 and the dynamic vibration absorber 13 are reversed with respect to the embodiment shown in FIG. Since the other parts are the same as those of the previous embodiment, the same reference numerals are assigned to the corresponding parts, and the description thereof is omitted.

  Next, still another embodiment of the present invention will be described. FIG. 9 is a view showing still another embodiment of the present invention, and corresponds to the same part as FIG. In the previous embodiment, the entire elastic body 20 is made of the same material. However, in this embodiment, the housing 11 has a first elastic body portion 27b that supports the main chassis 12, and the main chassis. 12 changes the material of the second elastic body portion 27 a that supports the dynamic vibration absorber 13.

  In this embodiment, the elastic body 27 is the same as the previous embodiment except that the elastic body 27 has two portions 27a and 27b made of two different materials. The description is omitted. The elastic body 27 has a recess 27c for supporting the housing 11 and a recess 27d for supporting the main chassis 12.

  Referring to FIG. 9, in this embodiment, elastic body 27 includes a second elastic body portion 27 a that constitutes a dynamic vibration absorber, and a first elastic body portion 27 b in which housing 11 holds main chassis 12. including. The boundary between the second elastic body portion 27 a and the first elastic body portion 27 b is the lower surface of the concave portion 27 d that supports the main chassis 12.

  As described above, the elastic body 27 is divided into the first elastic body portion 27a that constitutes the dynamic vibration absorber and the second elastic body portion 27b that holds the housing. A more suitable desired elastic modulus can be obtained in each of the portion constituting the container and the portion holding the main chassis.

  Note that, as in this embodiment, the method of connecting different materials may be any method that maintains the function, such as two-color molding (integral molding) or bonding of the upper and lower portions of the damper.

  Also in this embodiment, the modifications shown in FIGS. 5 to 8 in the previous embodiment may be adopted.

  In the above-described embodiment, an example using only an elastic body has been described. However, the present invention is not limited to this, and a separate attenuator may be used.

  In the above embodiment, the case where the housing, the main chassis, and the dynamic vibration absorber are supported by four elastic bodies in which the first elastic body portion and the second elastic body portion are integrated has been described. Not limited to this, it may be supported by three elastic bodies, or an integrated elastic body may be used for any number of the three or four support portions.

  In each of the above-described embodiments, as the elastic body, a “thermosetting elastic body (rubber)” or a “thermoplastic elastic body (thermoplastic elastomer)” may be used. Specifically, the “thermosetting elastic body (rubber)” includes natural rubber, butadiene rubber, styrene butadiene rubber, acrylonitrile butadiene rubber, isoprene rubber, chloroprene rubber, butyl rubber, halogenated butyl rubber, ethylene propylene rubber, chloro Examples include sulfonated polyethylene, chlorinated polyethylene, acrylic rubber, fluorine rubber, urethane rubber, and silicone rubber.

  As the “thermoplastic elastomer (thermoplastic elastomer)”, thermoplastic elastomers such as styrene thermoplastic elastomer, olefin, polyester, polyurethane, vinyl chloride, and polyamide can be used.

  Although one embodiment of the present invention has been described with reference to the drawings, the present invention is not limited to the illustrated embodiment. Various modifications can be made to the illustrated embodiment within the same scope or equivalent scope as the present invention.

  Since the dynamic vibration absorber according to the present invention can absorb vibrations over a wide range of mass eccentricity even at high rotation, it can be advantageously used in an optical disk device or the like using the vibration absorber.

It is a perspective view which shows the principal part of the optical disk apparatus using the dynamic vibration damper concerning this invention. It is sectional drawing of the part shown by II-II in FIG. FIG. 3 is an enlarged view of a portion indicated by III in FIG. 2. It is a figure which shows the vibration measured value of the optical disk apparatus which has a dynamic vibration damper of the structure shown in FIG. It is sectional drawing which shows the other example corresponding to FIG. 3 of a dynamic vibration absorber. It is sectional drawing which shows the further another example corresponding to FIG. 3 of a dynamic vibration absorber. It is sectional drawing which shows the further another example corresponding to FIG. 3 of a dynamic vibration absorber. It is a figure which shows other embodiment of the dynamic vibration damper concerning this invention. It is sectional drawing which shows the further another example corresponding to FIG. 3 of a dynamic vibration absorber. It is a perspective view of the optical disk device which has the conventional dynamic vibration absorber. It is a figure which shows the elastic body which comprises the conventional dynamic vibration damper. It is a figure which shows the vibration measured value of the optical disk apparatus which has the conventional dynamic vibration absorber.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Optical disk apparatus, 11 Case, 12 Main chassis, 13, 15, 16 Dynamic vibration absorber, 14 Protrusion part, 20, 24 Elastic body, 21 Through hole, 22 Step part, 31 Spindle motor, 32 Optical pick-up holder, 33 guide.

Claims (8)

A dynamic vibration absorber held by a main chassis that supports a motor that drives an optical disk,
The main chassis is held in the housing via the first elastic body,
Including a second elastic body for supporting a dynamic vibration absorber constituting the dynamic vibration absorber on the main chassis;
The first elastic body and the second elastic body are integrated,
A dynamic vibration absorber including rigidity means for increasing rigidity of the second elastic body. The second elastic body has a recess;
The dynamic vibration absorber has a protrusion,
2. The dynamic vibration absorber according to claim 1, wherein the rigid means includes a protruding portion of the dynamic vibration absorber that is fitted into a concave portion of the second elastic body. The second elastic body has a recess;
The dynamic vibration absorber according to claim 1, wherein the rigid means includes a filler that fills the concave portion of the second elastic body. The first elastic body has a hollow portion inside,
The second elastic body includes a solid part inside,
The dynamic vibration absorber according to any one of claims 1 to 3, wherein the rigid means is a solid part inside the second elastic body. The dynamic vibration absorber according to any one of claims 1 to 4, wherein the first elastic body and the second elastic body are made of the same material. The dynamic vibration absorber according to any one of claims 1 to 4, wherein the first elastic body and the second elastic body are made of different materials. A dynamic vibration absorber held by a main chassis that supports a motor that drives an optical disk,
The main chassis is held in the housing via the first elastic body,
A dynamic vibration absorber constituting the dynamic vibration absorber is supported on the main chassis, and includes a second elastic body made of a material different from the first elastic body,
The first elastic body and the second elastic body are integrated,
A dynamic vibration absorber including rigidity means for increasing rigidity of the second elastic body. An optical disk device on which the dynamic vibration absorber according to any one of claims 1 to 7 is mounted.

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