JP2003206989A - Vibration isolation structure of anisotropic damper and mechanical chassis - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration isolation structure of a damper and a mechanical chassis which can support further thinning of entire equipment without losing a vibration isolation characteristic, and more specifically, to provide a vibration isolation structure of a damper and a mechanical chassis which can restrain relative displacement in the vertical direction of the mechanical chassis against an exterior member. <P>SOLUTION: In this anisotropic damber 21 of the present invention, a flexible member 23 made of a rubber-state elastic body is formed in the rectangular dome shape having a vertical part 23b in the almost vertical direction of the mechanical chassis in the mounted state and a horizontal part 23c in the almost horizontal direction of the mechanical chassis, relative displacement of the mechanical chassis in the vertical direction is restrained by hardening a spring constant through reduction of the length of the vertical part 23b, and the spring constant is softened by increasing the length of the horizontal part 23c so that a high vibration-isolation and damping effect can be gained in the lateral direction. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a damper for damping vibration in a vibration transmission path. More specifically, optical disks such as CDs, magneto-optical disks such as MOs, magnetic disks such as hard disks, etc., which are used in audio equipments including those for automobiles and consumer use, video equipments, information equipments, various precision equipments, etc. A mechanical chassis that mounts a non-contact reading mechanism for various disc-shaped recording media and a damper that is suitable for attenuating external vibrations and internal vibrations that are transmitted between an exterior member that encloses the mechanical chassis and a mechanical chassis that protects the mechanical chassis. It relates to a vibration structure.

[0002]

2. Description of the Related Art With respect to a disk-shaped recording medium (hereinafter simply referred to as "disk") as described above, recorded data is read by a non-contact method using an optical pickup or a magnetic head. Although such a non-contact reading mechanism is mounted on the mechanical chassis, various anti-vibration measures have been taken for the above-mentioned various devices including the mechanical chassis as an exterior member because the reading method is non-contact. As an example thereof, there is known an example in which a damper is interposed between an exterior member and a mechanical chassis to elastically support the mechanical chassis in a floating state.

FIG. 7 shows the first conventional example,
Reference numeral 1 is an exterior member, and 2 is a mechanical chassis. A disc 3 is mounted on the mechanical chassis 2, and the data recorded on the disc 3 is read by a non-contact reading mechanism mounted on the mechanical chassis 2. A damper 4 is attached between the mechanical chassis 2 and the exterior member 1. The damper 4 is of a cylindrical insulator type as shown in FIG. 8, and is formed of a rubber-like elastic body such as styrene elastomer. The damper 4 has an insertion hole 4a along its axis.
Are formed so as to penetrate, and the screw 4 inserted therein is screwed onto the exterior member 1, whereby the damper 4 is fixed to the exterior member 1. Further, the damper 4 has a small-diameter recess 4b.
Is formed, and the mounting portion 2a of the mechanical chassis 2 engages with the recess 4b, whereby the damper 4
Is fixed to the mechanical chassis 2. In the first conventional example, three such insulator type dampers 4 are used to elastically support the mechanical chassis 2 against the exterior member 1 in a floating state.

Further, FIG. 9 shows a second conventional example, and the damper 5 in this conventional example is as shown in FIG.
A substantially cylindrical peripheral wall member 6 formed of a hard resin such as polypropylene, and a flexible member 7 formed of a rubber-like elastic body such as a thermoplastic elastomer and closing the one end side opening of the peripheral wall member 6. , A lid member 8 made of a hard resin such as polypropylene and closing the opening on the other end side of the peripheral wall member 6.
And a viscous fluid 9 made of silicone oil or the like, which is filled in an internal space formed by these members and acts on vibration damping. A mounting recess 7a is formed in the flexible member 7 made of a rubber-like elastic body. In the mechanical chassis 10, a support shaft 10b protruding from a side wall 10a of the mechanical chassis 10 is inserted into the mounting recess 7a and held therein. As a result, the damper 5 and the coil spring S provide vibration-proof support. Then, the damper 5 is fixed to the exterior member 1 by inserting a screw N into the insertion hole 8 a formed in the lid member 8 and screwing the screw N into the screw hole of the exterior member 1. In the second conventional example, three such viscous fluid-filled dampers 5 are used to elastically support the mechanical chassis 10 with respect to the exterior member 1 in a floating state. There is.

[0005]

By the way, with regard to notebook type personal computers, portable electronic devices, etc., there is a remarkable tendency toward thinning of the entire device.
There is a rapid demand for anti-vibration measures in a small internal space. The above-mentioned first conventional example and second conventional example are intended to be able to cope with the anti-vibration measures in such a narrow internal space, and can exhibit anti-vibration characteristics that meet the demand. Has become. That is, in the first conventional example,
Since the insulator-type damper 4 whose height can be set relatively low is used, it is possible to make the exterior member 1 thinner in the vertical direction y. Further, in the second conventional example, since the lid member 8 of the damper 5 is fixed to the side plate portion 1a of the exterior member 1 and the damper 5 is mounted laterally along the lateral direction x, for example, the damper 5 is exteriorly mounted. The exterior member 1 can be made thinner in the vertical direction y than in the case where it is attached to the bottom plate portion 1b of the member 1.

However, recently, there are many demands for further thinning of the entire device, and if the above-mentioned first conventional example and second conventional example are applied as they are, satisfactory vibration damping characteristics are exhibited. Things are getting harder. That is,
In order to improve the damping effect in these conventional examples, a rubber-like elastic body (styrene-based elastomer) having a low hardness is used for the damper 4 of the first conventional example, and it is possible to use the damper 5 of the second conventional example. The hardness of the rubber-like elastic body (thermoplastic elastomer) forming the flexible member 7 is lowered, or the viscous fluid 9
It is conceivable to reduce the viscosity of. However, in order to further reduce the thickness of the entire device, the gaps between the various components provided inside the exterior member 1 are becoming smaller, so that the buoyancy, disturbance vibration, and internal disturbance generated when the disk 3 rotates at high speed. The vibration causes the disk 3 itself and the mechanical chassis 2 and 10 to float in the vertical direction y, and the vibration causes the disk 3 to float in a floating state, which may make contact with the inner surface of the exterior member 1 and various parts around it. , There was a problem.

In order to avoid this problem, for example, the first
In the conventional example, as in the damper 12 shown in FIG. 8B, the large-diameter upper and lower portions are formed by the high-elasticity portion 12a, and the small-diameter intermediate portion is formed by the low-elasticity portion 12b. It is possible. That is, the high elasticity portion 12a performs vibration damping in the vertical direction y, and the low elasticity portion 12b performs vibration damping in the horizontal direction x, so that the high elasticity portion 12a as a whole acts in the vertical direction of the disk 3 and the mechanical chassis 2. The displacement should be suppressed. However, this has a problem that the damping effect against external vibration is deteriorated due to the influence of the high elasticity portion 12a.
Then, we could not expect any other improvement measures to cope with the further reduction in thickness of the entire device without impairing the vibration isolation characteristics.

In the second conventional example, the contact problem described above can be solved by increasing the hardness of the rubber-like elastic body forming the flexible member 7 and the viscosity of the viscous fluid 9; Similar to the conventional example, the damping effect against external vibration is reduced.

The present invention has been made against the background of the above-mentioned conventional examples and the improvement measures thereof, and an object of the present invention is to further reduce the thickness of the entire device without impairing the vibration damping characteristics. The purpose of the present invention is to provide an anti-vibration structure for the damper and the mechanical chassis, which is possible by the following means.

[0010]

[Means for Solving the Problems] That is, a cylindrical peripheral wall member and a flexible member made of a rubber-like elastic body for closing an opening on one end side of the peripheral wall member are provided, and the peripheral wall member or the flexible member is provided. Any one of the above is attached to a mechanical chassis mounted with a non-contact type reading mechanism of a disk-shaped recording medium, and the other one is attached to an exterior member surrounding the mechanical chassis to attach the mechanical chassis to the exterior member. With respect to a damper that supports vibration isolation in a floating state with respect to a vertical portion that displaces the flexible member in a substantially perpendicular direction of the mechanical chassis in the mounted state, a length of the mechanical chassis that is longer than the vertical portion of the mechanical chassis. A horizontal part that is aligned in the direction of the surface,
It is an anisotropic damper characterized by having a rectangular dome shape having.

Among the flexible members, this anisotropic damper is
By making the spring constant hard for the part that corresponds to the approximately vertical direction of the mechanical chassis and softening the spring constant for the part that corresponds to the approximately horizontal direction of the mechanical chassis, the disk speed increases. A high damping effect is exhibited while suppressing relative displacement between the mechanical chassis and the exterior member caused by buoyancy, internal vibration, and external vibration when rotating.

That is, the rubber-like elastic body forming the flexible member has a predetermined hardness satisfying the desired vibration-damping characteristics, and the spring constant is made hard in the vertical direction by the vertical portion having a short length. In the lateral direction (horizontal direction), the spring constant is softened by the horizontal portion whose length is longer than the vertical portion. Therefore, unlike the second conventional example, it is not necessary to increase the hardness of the flexible member in a direction that unavoidably impairs the vibration damping effect, and in the viscous fluid-sealed damper, the viscosity of the viscous fluid is increased. There is no need, and even if the hardness and viscosity are such that desired vibration damping characteristics can be exerted, it is possible to exert a high damping effect while suppressing the buoyancy acting on the disc and the mechanical chassis. The anisotropic damper of the present invention is also applied as a viscous fluid-filled damper, and also as an air damper that has a ventilation hole in a peripheral wall member or the like and exerts a vibration damping effect by air resistance flowing in and out of the ventilation hole. can do.

Further, according to the present invention, in the anisotropic damper, the horizontal portion is formed thicker than the vertical portion.

Since the thickness of the horizontal portion is made thicker than the thickness of the vertical portion, it is possible to strengthen the relative displacement of the mechanical chassis and the exterior member in the vertical direction, and further to suppress the displacement to a small extent. it can.

Further, according to the present invention, in the anisotropic damper, the horizontal portion is formed by making the wall thickness on the top side smaller than the wall thickness on the annular base end side fixed to the one end side opening of the peripheral wall member. It is a thing.

Since the wall thickness of the apex side is thinner than the wall thickness of the annular base end side without making the wall thickness of the horizontal portion equal, there is an adverse effect on the damping performance on the side fixed to the peripheral wall member. The relatively small thickness of the annular end portion side hardens the spring constant in the vertical direction, so that the relative displacement in the vertical direction between the mechanical chassis and the exterior member can be suppressed. In the lateral direction, the vibration damping performance can be enhanced by the thin top side. Therefore, the vibration damping performance and the buoyancy suppression can be exhibited in a better balance than the flexible member having the uniform thickness.

In this case, even if the horizontal portion of the flexible member is such that the wall thickness gradually changes from the annular end portion side to the top side, the wall thickness also changes with a surface difference at the step portion. It may be configured to do so.

Further, according to the present invention for achieving the above object, the peripheral wall member of a damper is provided with a cylindrical peripheral wall member and a flexible member made of a rubber-like elastic body for closing an opening portion on one end side of the peripheral wall member. Or one of the flexible members is attached to a mechanical chassis on which a non-contact type reading mechanism for a disk-shaped recording medium is mounted, and the other one is attached to an exterior member surrounding the mechanical chassis, and the damper is used. Regarding a vibration isolating structure of a mechanical chassis for supporting a mechanical chassis in a floating state with respect to an exterior member, a flexible member of the damper is a rectangle having a vertical portion having a short length in the longitudinal direction and a horizontal portion having a long length. It was dome-shaped, and the vertical portion was attached so as to be aligned in the substantially perpendicular direction of the mechanical chassis, and the horizontal portion was attached so as to be aligned in the substantially surface direction of the mechanical chassis. It is characterized by a door.

According to the vibration isolating structure of the mechanical chassis, the flexible member of the damper has a rectangular dome shape having a vertical portion having a short length in the longitudinal direction and a horizontal portion having a long length, and Since the vertical portion is attached so as to be aligned in the substantially vertical direction of the mechanical chassis, and the horizontal portion is attached so as to be aligned in the substantially planar direction of the mechanical chassis, the rubber-like elastic body forming the flexible member has the desired vibration-proof characteristics. While having a predetermined hardness that satisfies the above, the spring constant is hardened by the vertical portion having a short length in the vertical direction, and the horizontal constant having a length longer than the vertical portion in the horizontal direction (horizontal direction). The spring constant is softened. Therefore, unlike the second conventional example, it is not necessary to increase the hardness of the flexible member in a direction that unavoidably impairs the vibration damping effect, and in the viscous fluid-sealed damper, the viscosity of the viscous fluid is increased. There is no need, and even if the hardness and viscosity are such that desired vibration damping characteristics can be exerted, it is possible to exert a high damping effect while suppressing the buoyancy acting on the disc and the mechanical chassis.

In this case, as a concrete mounting form of the damper, a side wall portion is provided in the mechanical chassis in the vertical direction (vertical direction), and the side wall portion has a lid for closing the other end side opening portion of the peripheral wall member of the damper. The member is fixed by fixing means such as screwing, and the supporting shaft is projected inwardly on the exterior member, and the supporting shaft is inserted and held in the mounting recess formed in the flexible member of the damper. A damper may be attached between the exterior member and the mechanical chassis. On the contrary, the lid member of the damper is fixed to the inner surface of the side plate portion of the exterior member, and the support shaft protruding from the side wall portion of the mechanical chassis is inserted and held in the mounting recess of the flexible member of the damper. The damper may have such a mounting structure.

Further, according to the present invention, in the damper in the vibration isolating structure of the mechanical chassis, the wall thickness of the horizontal portion is made thicker than the wall thickness of the vertical portion.

Since the wall thickness of the horizontal portion is made thicker than the wall thickness of the vertical portion, it is possible to strengthen the relative displacement of the mechanical chassis and the exterior member in the vertical direction, and to further suppress the displacement. it can.

Further, according to the present invention, in the damper in the vibration isolating structure of the mechanical chassis, the wall thickness on the top side is thinner than the wall thickness on the annular base end side fixed to the one end side opening of the peripheral wall member. The horizontal part is formed.

Since the wall thickness of the top portion is smaller than the wall thickness of the annular base end portion without making the wall thickness of the horizontal portion equal, there is an adverse effect on the damping performance on the side fixed to the peripheral wall member. The relatively small thickness of the annular end portion side hardens the spring constant in the vertical direction, so that the relative displacement in the vertical direction between the mechanical chassis and the exterior member can be suppressed. In the lateral direction, the vibration damping performance can be enhanced by the thin top side. Therefore, the vibration damping performance and the buoyancy suppression can be exhibited in a better balance than the flexible member having the uniform thickness.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In addition, the same reference numerals are used for the same members in each embodiment, and the duplicated description will be omitted.

First Embodiment [FIGS. 1 to 3]

The anisotropic damper 21 of this embodiment includes a cylindrical peripheral wall member 22, a flexible member 23, a lid member 24, and
The viscous fluid 9 is enclosed in the internal space formed by these components.

As shown in the plan view of FIG. 1, the peripheral wall member 22 is formed in a substantially rectangular shape having a vertical portion 22a and a horizontal portion 22b. The vertical portion 22a is attached to the exterior member 1 with its length direction aligned with the vertical direction y, and the horizontal portion 22b is attached with its length direction aligned with the horizontal direction x.

As a material of the peripheral wall member 22, one having rigidity is preferable, and a thermoplastic resin is used according to required performance such as dimensional accuracy, heat resistance, mechanical strength, durability and reliability of target parts. It is possible to select from thermosetting resins, metals and the like. As an example of the thermoplastic resin, polyethylene resin, polypropylene resin, polyvinyl chloride resin, polystyrene resin, acrylonitrile-styrene-acrylate resin, acrylonitrile-
Butadiene / styrene resin, polyamide resin, polyacetal resin, polycarbonate resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polyphenylene oxide resin, polyphenylene sulfide resin, polyurethane resin, polyphenylene ether resin, modified polyphenylene ether resin, silicone resin, polyketone resin, liquid crystal Polymers and their composites can be used. As the thermosetting resin, a phenol resin, an epoxy resin, a silicone resin, a polyurethane resin, a melamine resin, an unsaturated polyester resin or the like, or a composite material thereof can be used. As metal, stainless steel,
Various die casts are available.

The flexible member 23 having the annular end portion 23a fixed to the opening on one end side of the peripheral wall member 22 as described above is formed in a rectangular dome shape like the peripheral wall member 22 and has an overall thickness. The thickness is constant in each part.

The flexible member 23 has a vertical portion 23b having a length d2 that is aligned in the direction perpendicular to the upper surface 10c of the mechanical chassis 10, that is, the vertical direction y, and the surface direction of the mechanical chassis 10, that is, the lateral direction. In FIG. 3, for convenience of explanation, the longitudinal direction of the exterior member 1 is shown as the horizontal direction x, but the horizontal direction x has a length d1 that is horizontal. The part 23c is formed.

Bent-shaped curved portions 23e and 23f are formed on each vertical portion 23b with the bent portion 23d as a boundary. Since the flexible member 23 has a rectangular dome shape, the curved portion 23e is shorter than the curved portion 23f in the length direction. Further, each horizontal portion 23c is also formed with bulging curved portions 23g and 23h having different lengths with the bent portion 23d as a boundary. The vertical portion 23b and the horizontal portion 23c are continuous with a bulging curved surface at four corners 23i where they intersect.

The top portion 23k where the vertical portion 23b and the horizontal portion 23c converge is a flat portion, and a shaft holding portion 23m projecting inward of the peripheral wall member 22 is formed at the center portion thereof. The mechanical chassis 10 is attached to the anisotropic damper 21 by inserting and holding the support shaft 10b of the side wall portion 10a into the attachment recess 23n of the shaft holding portion 23m.

Here, the characteristics required as the material of the flexible member 23 will be described. It is preferable that the material has high durability and damping characteristics and low creep characteristics. Specifically, regarding the durable physical properties, the rubber tensile physical properties are preferably 2 MPa or more, and more preferably 4 MPa or more. Regarding the damping characteristics, a high damping material having a loss coefficient tan δ of 0.05 or more (25 ° C.), preferably 0.2 or more is suitable. If the loss coefficient tan δ is less than 0.05, the amplitude of the mechanical chassis 10 at the time of resonance becomes large and the exterior member 1
This is because there is a risk of contact with. Regarding creep characteristics, compression set (70 ° C x 22 hours) was 50
% Or less, preferably 30% or less, having a low creep characteristic is suitable. 5 compression set (70 ° C x 22 hours)
This is because if it is larger than 0%, the displacement amount of the mechanical chassis 10 after being left for a long time becomes large and there is a possibility that the mechanical chassis 10 may come into contact with the exterior member 1.

The material of the flexible member 23 that requires the above-mentioned characteristics is required to have desired dimensional accuracy, heat resistance, mechanical strength, durability, reliability, anti-vibration characteristics, anti-vibration characteristics, etc. It can be selected from thermoplastic elastomer, crosslinked rubber and the like depending on the performance. As an example of the thermoplastic elastomer, a styrene-based thermoplastic elastomer,
An olefin-based thermoplastic elastomer, a polyester-based thermoplastic elastomer, a polyurethane-based thermoplastic elastomer, a polyamide-based thermoplastic elastomer, a vinyl chloride-based thermoplastic elastomer and the like can be used. As the crosslinked rubber, natural rubber, butadiene rubber, isoprene rubber, styrene-butadiene copolymer rubber, nitrile rubber, hydrogenated nitrile rubber, chloroprene rubber, ethylene propylene rubber, chlorinated polyethylene, chlorosulfonated polyethylene, butyl rubber and halogenated butyl rubber. , Acrylic rubber, fluorine rubber, urethane rubber, silicone rubber, etc. can be used.

The lid member 24 closes the opening on the other end side of the peripheral wall member 22, and the outward flange 2 of the peripheral wall member 22.
2c is formed in a shape relative to 2c, and is fixed to the outward flange 22c by ultrasonic welding. The material is the same as that of the peripheral wall member 22.

Next, the mounting structure of the anisotropic damper 21 will be described. As shown in FIG. 3, the anisotropic damper 21 is mounted by aligning the vertical portion 23b of the flexible member 23 with the vertical direction y of the upper surface 10c of the mechanical chassis 10, that is, the horizontal portion 23c. 10 face directions,
That is, it is attached along the lateral direction x. When attaching the cover member 24, the lid member 24 is attached to the side plate portion 1a of the exterior member 1.
It is fixed by adhesion to. Even if the lid member 24 is not adhered, the lid member 24 is screwed to the side plate portion 1a of the exterior member 1, or a hook-shaped engaging piece is provided on the lid member 24 or the peripheral wall member 22, and the lid member 24 is attached to the exterior member 1. It may be fixed by engaging it, or conversely, a hook-like engaging piece may be provided on the exterior member 1 and this may be fixed by engaging it with the lid member 24 or the peripheral wall member 22. In addition to such mechanical fixing means, fixing may be performed by chemical fixing means such as fusion or welding. The coil spring S surrounds the anisotropic damper 21 so that the support shaft 10b of the mechanical chassis 10 is supported.
To the mounting recess 23 of the flexible member 23 of the anisotropic damper 21.
Insert into n and hold. In this embodiment, since the mechanical chassis 10 is supported by the three anisotropic dampers 21 in a vibration-proof manner, the above-described mounting work is performed for the three anisotropic dampers 21 to produce an anisotropic shape as shown in FIG. A mounting structure for the sex damper 21 is obtained.

Next, the operation and effect of the anisotropic damper 21 according to the first embodiment and its mounting structure will be described.

The flexible member 23 of the anisotropic damper 21 has a spring constant made hard by the vertical portion 23b having a short length d2 in the vertical direction y in the direction perpendicular to the plane of the mechanical chassis 10. In the horizontal direction x, the spring constant is softened by the horizontal portion 23c whose length d1 is longer than the vertical portion 23b. Therefore, in the relative displacement between the exterior member 1 and the mechanical chassis 10 in the vertical direction y caused by the internal vibration, the external vibration, or the buoyancy when the disk 3 rotates at a high speed, the length d2 is short and the spring constant is hard. Is suppressed by the vertical portion 23b. On the other hand, the vibration in the lateral direction x is damped by the horizontal portion 23c having a long length d1 and a softened spring constant. Therefore, as in the above-described conventional example, the hardness of the flexible member 23 is increased or the viscous fluid 9
It is not necessary to increase the viscosity of the disk 3 and even if the hardness and the viscosity of the disk 3 are maintained so that the desired vibration damping characteristics can be exhibited, the disk 3
It is possible to exhibit a high damping effect while suppressing relative displacement between the mechanical chassis 10 and the mechanical chassis 10.

Second Embodiment [FIG. 4, FIG. 5, FIG. 3]

The anisotropic damper 31 of this embodiment differs from the anisotropic damper 21 of the first embodiment in the configuration of the peripheral wall member 32 and the flexible member 33. Note that the other configurations of the anisotropic damper 31 and the mounting structure thereof are the same as those in the first embodiment.

Peripheral wall member 3 constituting the anisotropic damper 31
2, the width (thickness) d3 of the vertical portion 32a is different from the width (thickness) d4 of the horizontal portion 32b. This is the peripheral wall member 3
The shape corresponds to the shape of the annular end portion 33a of the flexible member 33 fixed to the second open end 32c. That is, in the flexible member 33 of this embodiment, the vertical portion 33b has the same thickness d5 as a whole (FIG. 5B), but the mounting recess 33e of the shaft holding portion 33d is sandwiched in FIG. 4B. The wall thickness of the horizontal portion 33c corresponding to the hatched area r surrounded by the two-dot chain line shown above and below is the wall thickness d5 of the vertical portion 33b in the annular terminal portion 33a.
The thickest part is thicker than
It is formed so as to be gradually thinned toward a flat top portion 33f having the same thickness as the thickness d5 of b (FIG. 5A). At the boundary between the vertical portion 33b and the horizontal portion 33c on the back surface of the flexible member 33 (the portion indicated by the alternate long and two short dashes line in FIG. 4), an inclined surface is formed from the thick horizontal portion 33c to the thin vertical portion 33b. ing.

As described above, the feature of the flexible member 33 of the anisotropic damper 31 of this embodiment is that the vertical portion 33b.
And the horizontal portion 33c have different wall thicknesses.
In regard to the above, the wall thickness is changed from the annular terminal portion 33a to the top portion 33f. With this configuration, the anisotropic damper 31 can exert the following action / effect in addition to the action / effect of the anisotropic damper 21 of the first embodiment. That is, the horizontal portion 33c is fixed to the peripheral wall member 32 and has a relatively large spring constant on the side of the thick annular end portion 33a which has a relatively small influence on the vibration damping performance, and from there, the top portion 33c.
The spring constant becomes softer on the side of the mounting recess 33e by gradually reducing the thickness toward f. Therefore, on the side of the annular end portion 33a of the horizontal portion 33c having a hard spring constant, the exterior member 1 is further provided.
With respect to the relative displacement of the mechanical chassis 10 in the vertical direction y, the displacement is strong, and the displacement can be further reduced. Then, on the side of the mounting recess 33e of the horizontal portion 33c having a soft spring constant, the deformation in the lateral direction x is flexible and high damping performance can be exhibited.

Third Embodiment [FIG. 6]

The anisotropic damper 41 of this embodiment is a modification of the anisotropic damper 31 of the second embodiment, except that the structure of the horizontal portion 42a of the flexible member 42 is different from that.
Other configurations are similar to those of the second embodiment. That is,
In the flexible member 42, the horizontal portion 42a has an annular end portion 42b.
From the top portion 42c to the top portion 42c, and is thicker than the vertical portion 42d. Then, at the boundary portion (the broken line portion shown in FIG. 6A) between the horizontal portion 42a and the vertical portion 42d on the back surface of the flexible member 42, the thick horizontal portion 42.
A step portion 42e is formed from a to the thin vertical portion 42d.

According to the anisotropic damper 41 of the third embodiment, the horizontal portion 42a is thicker than the vertical portion 42d as compared with the anisotropic damper 31 of the second embodiment, and Since the wall thicknesses are the same, the restraint against the relative displacement of the exterior member 1 and the mechanical chassis 10 in the vertical direction y is further strengthened, and the displacement is further restrained.

Next, examples will be described.

[0048]

Example 1 Example 1 corresponds to the anisotropic damper 21 of the first embodiment described above, and its mounting structure is as shown in FIG.

Specifically, a polypropylene resin and a styrene thermoplastic elastomer were two-color molded to prepare a peripheral wall member (22) and a flexible member (23). And after injecting the viscous fluid (9) into it, the outward flange (2
2c) and a lid member (24) made of polypropylene resin are sealed by ultrasonic fusion, and an anisotropic damper (21)
Got

Annular end portion (23a) of the flexible member (23)
Has a rectangular shape with a longitudinal direction of 10 mm and a lateral direction of 6.5 mm. Moreover, the wall thickness of the flexible member (23) was 0.3 mm and made equal. Furthermore, the styrene-based thermoplastic elastomer forming the flexible member (23) has a hardness of 30 (J
IS K6253 type A), compression set 30%,
A loss factor tan δ of 0.20 (25 ° C) was used. The viscous fluid (9) has a rotational viscosity of 1.
2 m ² / s of silicone grease was used.

[0051]

Example 2 Example 2 corresponds to the anisotropic damper 31 of the second embodiment described above, and its mounting structure is the same as in FIG.

In the second embodiment, the vertical portion (33b) of the flexible member (33) has a thickness of 0.3 mm, and the horizontal portion (33c) has the thickest annular end portion (33a) of 0.6 mm. The anisotropic damper (31) is The horizontal part (33
c) is the thickest annular end (33a) to top (3)
The thickness was gradually reduced to 3f). Other configurations except the thickness of the flexible member (33) are the same as those of the anisotropic damper (21) of the first embodiment.

[0053]

Example 3 Example 3 corresponds to the anisotropic damper 31 of the second embodiment described above, and its mounting structure is the same as that shown in FIG.

In Example 3, the thickness of the vertical portion (33b) of the flexible member (33) is 0.3 mm, and the thickness of the horizontal portion (33c) is 0.9 mm at the thickest annular end portion (33a). The anisotropic damper (31) is The horizontal part (33
c) is the thickest annular end (33a) to top (3)
The thickness was gradually reduced to 3f). Other configurations except the thickness of the flexible member (33) are the same as those of the anisotropic damper (21) of the first embodiment.

[0055]

COMPARATIVE EXAMPLE 1 Comparative example 1 is a damper 1 shown in FIG.
2 and its mounting structure is as shown in FIG.

The damper (12) of Comparative Example 1 has a hardness of 90.
(JIS K6253 Type A) styrene elastomer with high elasticity (12a) and hardness 30 (JIS
The low elasticity portion (12b) made of a styrene elastomer of K6253 type A) was produced by two-color molding.

[0057]

Comparative Example 2 Comparative Example 2 corresponds to the damper 5 shown in FIG. 10, and its mounting structure is as shown in FIG.

In the damper (5) of Comparative Example 2, the shape of the peripheral wall member (6) and the flexible member (7) and the thickness of the flexible member (7) were set to 0.3 mm and the same thickness. The rest of the configuration is the same, except for the anisotropic damper (21) of 1.

An evaluation test was conducted on each of the above Examples and Comparative Examples. The evaluation test method is a vibration test. The conditions are as follows. In each of the examples, three anisotropic dampers (21, 31) were used to support the mechanical chassis (10) weighing 70 g with the mounting structure shown in FIG. Further, in Comparative Example 1, three mechanical dampers (12) were used to support the mechanical chassis (2) weighing 70 g with the vibration damping support by the mounting structure shown in FIG. 7. In Comparative Example 2, three dampers (5) were used to weigh 7
The mechanical chassis (10) having a weight of 0 g is supported by a vibration isolator with a mounting structure shown in FIG. The disk reproducing devices of the respective examples and the comparative examples in which the exterior member 1 is provided with the mechanical chassis (10, 2) are fixed to the vibration table.

The vibration table is vibrated in the vertical direction (longitudinal direction y) and in the left-right direction (horizontal direction x) at a constant acceleration of 5 m / s ² within a frequency range of 10 to 500 Hz to vibrate to the mechanical chassis (10, 2). The displacement of the mechanical chassis (10, 2) was measured at the resonance frequency by measuring the transmissibility. The resonance magnification is at the resonance frequency,
The vibration output acceleration a ₂ from the mechanical chassis (10, ₂ ) was measured with respect to the vibration input acceleration a ₁ from the vibration table, and converted by the relational expression of ₂₀ Log (a ₁ / a ₂ ).
Moreover, the disk (3) is rotated at high speed (9600 rpm).
The vibration leakage to the outside when the measurement was performed was measured by the G sensor. The results of this vibration test are shown in Table 1.

[0061]

[Table 1]

Comparing Examples 1 to 3 with Comparative Example 1, in Comparative Example 1, since the damper is of the insulator type, all evaluations in the vibration damping performance are compared with Examples 1 to 3. It turns out that it is inferior. Further, although the amount of displacement in the vertical direction is superior to that of the first embodiment, it does not have the required vibration damping performance.

Comparing Examples 1 to 4 with Comparative Example 2, in Comparative Example 2, the same evaluation as in Examples 1 to 3 was obtained in the evaluation of the vibration damping performance. Is clearly inferior to Examples 1 to 3 and also inferior in vibration leakage to the outside.

Therefore, according to Examples 1 to 3, the vertical displacement of the mechanical chassis can be significantly suppressed without reducing the vibration damping performance.
It can also be used to make devices thinner.

[0065]

EFFECT OF THE INVENTION According to the anisotropic damper of the present invention, the rubber-like elastic body forming the flexible member has a predetermined hardness satisfying the desired vibration damping characteristics, but has a short length in the longitudinal direction. The spring constant is hardened by the vertical portion, and the spring constant is softened by the horizontal portion whose length is longer than the vertical portion in the lateral direction (horizontal direction). Therefore, even if the hardness and viscosity are such that desired vibration damping characteristics can be exerted, a high damping effect can be exerted while suppressing the displacement between the disc and the mechanical chassis, and thus various devices equipped with the mechanical chassis can be provided. Further thinning can be supported.

According to the present invention in which the wall thickness of the horizontal portion is thicker than the wall thickness of the vertical portion, it is possible to strengthen the suppression of relative displacement of the mechanical chassis and the exterior member in the vertical direction.
Further, the displacement can be suppressed small.

According to the present invention, the wall thickness of the apex portion is thinner than the wall thickness of the annular base end portion, without making the wall thickness of the horizontal portion equal, and according to the present invention, the damping is made on the fixing side to the peripheral wall member. The spring constant in the vertical direction is hardened by the thick annular end portion side, which has a relatively small adverse effect on performance, and the relative displacement in the vertical direction between the mechanical chassis and the exterior member can be suppressed.
In the lateral direction, the vibration damping performance can be enhanced by the thin top side. Therefore, the vibration damping performance and the buoyancy suppression can be exhibited in a better balance than the flexible member having the uniform thickness.

[Brief description of drawings]

FIG. 1 is a front view of a damper according to a first embodiment.

FIG. 2 is a cross-sectional view of the damper shown in FIG. 1, in which FIG.
-The sectional view which follows the SB line, and the partial view (b) is the sectional view which follows the SC-SC line.

FIG. 3 is an explanatory diagram of a vibration isolation structure for a mechanical chassis using the dampers according to the first to third embodiments.

4A and 4B are explanatory views of a damper according to a second embodiment, where FIG. 4A is a front view of a peripheral wall member and FIG. 4B is a front view of a flexible member.

5 is a sectional view of the damper according to the second embodiment, in which FIG. 5A is a sectional view of the damper taken along the line SD-SD in FIG. 4;
FIG. 6B is a sectional view of the damper taken along the line SE-SE in FIG.

6A and 6B are explanatory views of a damper according to a third embodiment, where FIG. 6A is a front view and FIG. 6B is an SF-SF of FIG.
Sectional drawing which follows the line.

FIG. 7 is an explanatory diagram of a vibration isolation structure of a mechanical chassis according to a first conventional example.

8 is an external perspective view including a partial cross section of a damper used in the vibration damping structure of FIG. 7, where FIG. 8A is an external perspective view of one insulator type damper, and FIG. 8B is another insulator type damper. 3 is an external perspective view of the damper of FIG.

FIG. 9 is an explanatory diagram of a vibration isolation structure of a mechanical chassis according to a second conventional example.

10 is an explanatory view of a damper used in the vibration-proof structure of FIG. 9, where FIG. 10A is a sectional view of the damper taken along the line SA-SA in FIG. 10B, and FIG. 10B is a plan view of the damper. Fig.

[Explanation of symbols]

1 Exterior material 1a Side plate part 1b Bottom plate part 2 mechanical chassis 3 discs (disc-shaped recording media) 10 mechanical chassis 10a side wall 10b support shaft 10c upper surface 21 Anisotropic damper (first embodiment) 22 Peripheral wall member 22a vertical part 22b Horizontal part 23 Flexible member 23a annular terminal 23b vertical part 23c Horizontal part 23k top 24 Lid member 31 Anisotropic damper (second embodiment) 32 Peripheral wall member 32a vertical part 32b horizontal part 33 Flexible member 33a annular terminal 33b Vertical part 33c Horizontal part 33f top 41 Anisotropic Damper (Third Embodiment) 42 Flexible member 42a horizontal part 42b annular terminal 42c top 42d vertical part 42e Step portion x lateral direction y Vertical direction (perpendicular direction)

Claims (5)

[Claims] 1. A cylindrical peripheral wall member, and a flexible member made of a rubber-like elastic body that closes an opening on one end side of the peripheral wall member, and one of the peripheral wall member and the flexible member is a disk. Attached to a mechanical chassis mounted with a non-contact reading mechanism for a recording medium, and the other one of them is attached to an exterior member surrounding the mechanical chassis so that the mechanical chassis is in a floating state with respect to the exterior member. In a damper for vibration-proof support, the flexible member is aligned in a substantially vertical direction of the mechanical chassis in the mounted state, and is aligned in a substantially planar direction of the mechanical chassis having a length longer than the vertical part. An anisotropic damper having a rectangular dome shape having a horizontal portion. 2. The anisotropic damper according to claim 1, wherein the horizontal portion is thicker than the vertical portion. 3. The horizontal portion according to claim 1, wherein the horizontal portion is formed such that the thickness on the top side is thinner than the thickness on the annular base end side fixed to the one end side opening of the peripheral wall member. Directional damper. 4. The anisotropic damper according to claim 3, wherein the horizontal portion is gradually thinned from the annular base end side to the top side. 5. A damper comprising a tubular peripheral wall member and a flexible member made of a rubber-like elastic material that closes an opening on one end side of the peripheral wall member, and either one of the peripheral wall member and the flexible member is provided. It is attached to a mechanical chassis mounted with a non-contact type reading mechanism for a disk-shaped recording medium, and either one of the other is attached to an exterior member surrounding the mechanical chassis,
In a vibration isolating structure of a mechanical chassis in which the damper supports the mechanical chassis in a floating state with respect to an exterior member, a flexible member of the damper comprises a vertical portion having a short length in a longitudinal direction and a horizontal portion having a long length. It has a rectangular dome shape, and the vertical portion is attached so as to be aligned in a substantially vertical direction of the mechanical chassis, and the horizontal portion is attached so as to be aligned in a substantially planar direction of the mechanical chassis. Anti-vibration structure of mechanical chassis.