JPH0261882A - Vibration isolator for disk drive system - Google Patents

Abstract

PURPOSE:To improve vibration isolating capacity by forming first and second elastic characteristic parts with different proper frequencies integrally with a vibration isolating member. CONSTITUTION:The vibration isolating member 28 formed with an elastic mate rial is formed in almost cylindrical shape, and a groove 28a is formed at one end part along a periphery. Also, a groove 29a with prescribed width is formed almost in the central part of an inner plane along the inner plane, which comprises the first elastic characteristic part 29. Furthermore, plural projecting parts 30 protruding advancing from an inner peripheral plane to a center with a constant interval are formed at the lower end part of the inner plane along a shaft center, which comprises the second elastic characteristic part 30. The groove 28a of the vibration isolating member 28 is fitted in the through hole 25a of a main chassis 25 on which a disk drive mechanism part is mounted, and after a stud 32 is fitted in the vibration isolating member 28, a mounting screw 33 is screwed in a screw hole 31a formed at a mounting base 31 after inserting the mounting screw 33 through the stud 32. In such a way, the elastic characteristic parts 29 and 30 can be deflected with different spring constants, thereby, the vibration isolating capacity can be improved.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a disc drive system such as a compact disc player, and in particular, to a disc drive system including a pickup, etc., when external vibrations are applied. This invention relates to an improvement in a vibration isolating device that prevents vibration from being transmitted.

(Prior Art) As is well known, in the field of audio equipment, disk drive systems that read recorded information from a disk on which audio signals are digitized and recorded via an optical pickup have become widespread. Currently, for example, compact disc players are the mainstream.

FIG. 6 shows a schematic configuration of such a disk drive system. That is, the disk drive mechanism section 12 is housed in a substantially box-shaped cabinet 11 indicated by a two-dot chain line in the figure. A evening table 13 is rotatably supported approximately at the center of the disk drive mechanism section I2, and is driven to rotate by a disk motor (not shown).

Further, near the turntable 13, an optical pickup 14 is mounted by a guide shaft 15 as indicated by arrow A in the figure.

It is supported movably in the B direction. This pickup I4 is moved by the driving force of a linear motor (only the drive coil 16 is shown), and its moving speed and position are detected by a speed detector 18 having a detection coil 17 that moves together with the pickup I4. .

On the other hand, numeral 19 in the figure is a disk case, and a disk 20 is housed inside. This disk case 19 is
It is inserted into the cabinet 11 through an opening 11a formed on the front surface of the cabinet 11.

At this time, the disk case 19 is guided and inserted by the case guide member 21 of the disk drive mechanism section 12,
It is held in the final mounting position by a pressure spring 22. Then, with the disk case 19 in the loaded state, the disk 20 is placed on the turntable 13, and the long hole 19a formed in the disk case 19 corresponds to the lens portion 14a of the pickup 14, allowing playback. It becomes a state.

Further, the disc case 19 is ejected by being pushed out from the opening 11a by the ejection lever 24 driven by the driving force of the loading release motor 23.

Here, all the various parts constituting the disk drive mechanism section 12 described above are integrally mounted on the main chassis 25. The main chassis 25 includes four vibration isolating members 26 made of an elastic material such as rubber.
is supported in cabinet II by. As shown in FIG. 7, this vibration isolating member 2B has one end attached to a mounting portion 27 formed on the bottom plate 11b of the cabinet 1, and the other end attached to the main chassis 25. Then, install the disk drive mechanism section 12 into the cabinet II.
It is supported by floating inside.

Here, as shown in FIG. 8, the vibration isolating member 26 is formed into a substantially cylindrical shape, and grooves 26a and 2Gb formed along the outer periphery of both ends thereof are connected to the main chassis 2.
5 and the mounting portion 27 by fitting into through holes 25a27a formed in the mounting portion 27, respectively. This vibration isolation member 2G has a vibration isolation effect in both directions of arrows C and D in FIG. 8, and constitutes a three-dimensional vibration isolation mechanism.

When the vibration isolating member 26 is made of rubber, its vibration transmission characteristics are given by the following equation.

τ-(1+γ2)/f(1-η2)2+γ2)
...(1) However, τ indicates the force transmission rate, and γ indicates the loss coefficient. Also, η is the frequency ratio, f/f
o (f is the excitation frequency, fo is the natural frequency). Note that the natural frequency fO is expressed by the following equation.

fo - (1/2π) Yabe 7 seats
-(2) However, k indicates a spring constant, and m indicates mass.

FIG. 9 shows that in the above equation (1), the loss coefficient γ
The force transmissibility τ with respect to the frequency ratio η with as a parameter
2 shows a transmissibility resonance curve representing the change in . As is clear from this transmissibility resonance curve, one of the characteristics of rubber is that when the frequency ratio η is 1, that is, when the disturbance acceleration matches the natural frequency of Ki, a resonance phenomenon occurs and the vibration insulation effect will be hindered. Since this resonance phenomenon is a phenomenon of the rubber solid H, it cannot be avoided.

Therefore, it is necessary to reduce the value of τ at the resonance point, that is, the resonance magnification Q. However, the loss coefficient γ of the rubber used for vibration isolation in the crotch is in the range of 0.05 to 0.3. Therefore, even when the resonance magnification Q is the smallest, that is, when η-1 and γ-0.3 in equation (1) above, it is considered to be about 3.5 (11 dB), and the vibration isolation performance is There are limits to this.

However, in the pickup 14 used in the above-described disk drive system, the objective lens is supported by a metal piece, a molded spring, or the like, and therefore has a structure that is extremely susceptible to vibration. Therefore, there is a strong desire to develop a vibration isolating member that has a strong vibration isolating effect, has a simple structure, and is economically advantageous.

(Problems to be Solved by the Invention) As described above, in the conventional vibration isolating device for a disk drive system, there is a limit to the vibration insulating performance of the vibration isolating member, and it is difficult to obtain a sufficient vibration isolating effect, especially for pickups, etc. The problem is that it cannot be used.

Therefore, this invention was made in consideration of the above circumstances, and provides an extremely good vibration isolating device for a disk drive system that can greatly improve vibration isolating performance with a simple configuration and is economically advantageous. The purpose is to provide.

[Structure of the Invention] (Means for Solving the Problems) That is, a vibration isolator for a disk drive system according to the present invention is formed into a substantially cylindrical shape, and one end is attached to the disk drive mechanism, and The other end is attached to the mounting base, and the first elastic characteristic part has a groove of a constant width formed on the inner surface of the center part along the inner circumferential surface, and the inner circumferential surface of the inner surface of the end part is a second elastic characteristic portion in which protrusions protruding from the surface toward the center at regular intervals are formed;
The vibration isolating member is configured such that the natural frequencies of the elastic characteristic portions of the vibration damping members are made different.

(Function) According to the above configuration, since the first and second elastic characteristic portions having different natural frequencies are integrally formed in the vibration isolating member, the first and second elastic characteristic portions have different natural frequencies. Due to the mutual interference effect, the resonance magnification Q of the vibration system can be reduced, and the vibration damping performance can be greatly improved, and the structure can be simple and economically advantageous.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings. FIGS. 1(a) and 1(b) show a vibration isolating member 28 made of an elastic material such as rubber. This vibration isolating member 28 is formed into a substantially cylindrical shape, and a groove 28a is formed along the outer periphery at one end thereof.

The vibration isolating member 28 also has a
A groove 29a of a constant width is formed along the inner peripheral surface,
A first elastic characteristic section 29 is configured.

Furthermore, the vibration isolating member 28 has an inner surface shown in FIG.
) A plurality of (eight in the illustrated case) protrusions 3 protrude toward the center at regular intervals from the inner circumferential surface along the axis at the middle and lower end.
0a is formed, and the second elastic characteristic portion 30 is configured.

These first and second elastic characteristic portions 29 and 30 have different natural frequencies, or in other words, different spring constants, due to their different shapes. That is, by partially changing the shape, the first and second elastic characteristic portions 29 and 30 having mutually different elasticities are integrally formed in one vibration isolating member 28.

FIG. 2 shows that the main chassis 25 is attached to a mounting base 31 formed on the cabinet 11 by the vibration isolating member 28.
It shows the means to install it. First, main chassis 2
The groove 28a of the vibration isolating member 28 is inserted into the through hole 25a formed in the
mate. Next, after fitting the stud 32 into the vibration isolating member 28, the mounting screw 33 is inserted through the stud 32 and screwed into the screw hole 31a formed in the mounting base 31, as shown in FIG. Main chassis 25 as shown
is supported by the mounting base 31.

Suppose that in this state, vibration is applied to the cabinet 11 in the direction of arrow E in FIG. 3, for example. Then, the first and second elastic characteristic portions 29 and 30 of the vibration isolating member 28 are deflected with different spring constants, and the vibration energy is absorbed. At this time, the spring constants of the first and second elastic characteristic portions 29 and 30 are respectively kl.

k2 (kl > k2), the vibration isolating member 28 has two natural frequencies in the direction of arrow E, fl - (1/2π) f2- (1/2π) f2- (1/2π) , and resonance points of frequencies fl and f2 exist.

In this case, the relationship between the force transmissibility τ and the frequency f is expressed as
It is indicated by a dotted line in FIG. Note that Ql in FIG. 4 indicates the resonance magnification. Here, as a result of the experiment, the first and second
By changing the shape of the elastic characteristic part 29.30, the spring constant k
By adjusting the values of l and lc2, the curve I shown in FIG.

As shown in ■, the vibration transmission rate can be changed, and the resonance magnification can be set to 0.2. It can be reduced to Q3.

Therefore, according to the configuration of the above embodiment, since the first and second elastic characteristic portions 29 and 30 having different natural frequencies are integrally formed in one vibration isolating member 28, Due to mutual interference between the resonance points of the first and second elastic characteristic sections 29 and 30, the resonance magnification can be reduced and the vibration damping effect can be improved. According to experiments, a resonance magnification of 7 dB could be achieved when the loss coefficient γ was 0.5. Furthermore, since the vibration isolating member 28 is configured to form the first and second elastic characteristic portions 29 and 30 by changing its shape, the structure is simple and economically advantageous.

FIG. 5 shows another embodiment of the invention.

That is, the protrusion 30a constituting the second elastic characteristic section 30
A notch 30b is formed in the spring to reduce the spring constant.

It should be noted that the present invention is not limited to the above-described embodiments, and can be implemented with various modifications without departing from the gist thereof.

[Effects of the Invention] As detailed above, according to the present invention, it is possible to greatly improve the vibration damping performance by simply constructing a disk drive system, which is economically advantageous. A shaking device can be provided.

[Brief explanation of the drawing]

Fig. 1 shows an embodiment of the vibration isolating device for a disk drive system according to the present invention, and is a diagram showing the shape of the vibration isolating member, and Fig. 2 is an exploded perspective view showing the means for mounting with the vibration isolating member. , Fig. 3 is a side cross-sectional view showing how the vibration isolating means is installed, Fig. 4 is a characteristic curve diagram explaining the effects of the same embodiment, and Fig. 5 is a diagram showing another embodiment of the present invention. FIG. 6 is a perspective view schematically showing a disk drive system, FIGS. 7 and 8 are side sectional views showing conventional vibration isolation means, and FIG. 9 is a problem with the conventional means. It is a characteristic curve diagram for explaining. DESCRIPTION OF SYMBOLS 11... Cabinet, 12... Disk drive mechanism part, 13... Turntable, 14... Pick-up, 15... Guide shaft, 16... Drive coil, 1
7...Detection coil, 18...Speed detector, 19...
- Disc case, 20... Disc, 21... Case guide member, 22... Pressing spring, 23... Loading release motor, 24... Ejection lever 25... Main chassis, 26... Vibration isolating member, 27... Attachment part, 28... Vibration isolating member, 29... First elastic characteristic part,
30... Second elastic characteristic part, 31... Mounting base, 3
2...Stud, 33...Mounting screw. (a) Applicant's agent Patent attorney Takehiko Suzue (b) Figure 1 Figure Figure Figure Figure Figure Figure Figure Figure

Claims (1)

[Claims] A disk drive system in which a disk drive mechanism section is installed on a mounting base via a vibration isolating member, and includes a rotation drive section that rotates a disk and a reading section that reads recorded information from the disk rotated by the rotation drive section. In the vibration isolator, the vibration isolator is formed into a substantially cylindrical shape, one end of which is attached to the disk drive mechanism, and the other end of which is attached to the mounting base. A first groove having a constant width formed on the inner surface along the inner circumferential surface.
and a second elastic characteristic portion in which protrusions are formed on the inner surface of the end portion and protrude toward the center at regular intervals from the inner circumferential surface, and the first and second elastic A vibration isolator for a disk drive system, characterized in that it is configured to vary the natural frequencies of characteristic parts.