JP2002031190A - Vibration resistant device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the height of a vibration resistant device wherein a pressure air chamber which can be expanded and contracted vertically and a pressure air chamber which can be expanded and contracted horizontally are formed between a fixed table and a movable table through a flexible air tight member respectively. SOLUTION: In this vibration control device wherein vertical vibration is prevented from being transmitted to the movable table 30 by holding the movable table 30 and the articles placed on the movable table 30 floating by introducing the pressurized air of a compression air source into the pressure air chamber 40 in the perpendicular direction through a perpendicular pressure controlling system with the air pressure adjusted according to the weight of the movable table 30 and the articles placed on the movable table 30. At the same time, the horizontal vibration of the movable table 30 can also be prevented by introducing pressurized air into a pair of horizontal pressure air chambers 50 through a horizontal pressure control system with the air pressure adjusted, a flexible air tight member for forming the horizontal pressure air chamber 50 is made from a oblong bellows 51.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration isolator for preventing propagation of vibration from a fixed table to a movable table.

[0002]

2. Description of the Related Art Conventionally, as one kind of such vibration isolator, a pressurized air chamber is formed between a fixed table and a movable table via a flexible airtight member, and a pressurized air in the pressurized air chamber is formed. 2. Description of the Related Art An anti-vibration device based on the principle of controlling the intake and exhaust of air to keep a movable table in a floating state and prevent propagation of vibration is known.

In this conventional vibration isolator, in order to prevent the propagation of vibration in the horizontal direction, not only a pressure air chamber which can be expanded and contracted in the vertical direction but also a pressure air chamber which can be expanded and contracted in the horizontal direction is provided. Have been done. As the flexible airtight member forming the pressurized air chamber, a bellows having a cylindrical shape as a whole and having at least one semicircular cross section (waveform deforming portion) which can have a large pressure receiving area and stroke has been used. However, it is difficult to reduce the diameter of the bellows (it is difficult to manufacture a small-diameter bellows), and the height dimension of the vibration isolator is restricted by the bellows diameter. However, there is a case where the height of the vibration isolator is required to be reduced depending on the installation location, and the conventional vibration isolator cannot meet the demand for the reduction of the height.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to obtain a vibration isolator which can be reduced in height.

[0005]

SUMMARY OF THE INVENTION The present invention focuses on the fact that it is difficult to reduce the overall diameter of a bellows, but it is easier to form a bellows horizontally than to reduce the overall diameter. The air chamber was successfully formed with a horizontal bellows to reduce the height. That is, the vibration damping device according to the present invention includes a pressure air chamber that can be expanded and contracted in the vertical direction and a pressure air chamber that can be expanded and contracted in the horizontal direction, respectively, between the fixed base and the movable base via a flexible airtight member. In the vibration damping device, the flexible airtight member forming the horizontal pressure air chamber is formed into a cylindrical shape having a horizontal axis as a whole, and the diameter in the horizontal direction passing through the axis is vertical through the axis. It is characterized by comprising a horizontally long bellows larger than the diameter in the direction.

The shape of the oblong bellows may be, for example, a plane ellipse, an oval or a square.

[0007]

1 to 4 show a first embodiment of a vibration isolator according to the present invention. The fixing base 20 fixed on the base 10 has a bottom wall 21 and a flat cylindrical body 22. The flat cylindrical body 22 has a planar octagonal shape in the illustrated example, and the movable base 3 is placed in the flat cylindrical body 22 in a non-contact state.
0 is located. The movable base 30 has a substantially octagonal plane shape corresponding to the plane shape of the flat cylindrical body 22, and a concave portion 31 having an open lower surface is formed at the center thereof.

[0008] An upper bellows retainer 32 is fixed to the upper surface (bottom surface) of the movable base 30 in the lower opening 31.
The upper bellows retainer 3 is provided on the bottom wall 21 of the fixing base 20.
The lower bellows retainer 23 corresponding to 2 is fixed. A vertical pressure air chamber 40 is formed between the upper bellows retainer 32 and the lower bellows retainer 23.
Both ends of a bellows 41 having a vertical axis are airtightly fixed. The bellows 41 has a cylindrical shape as a whole macroscopically, and a plurality of semicircular sections 4 on its wall surface.
1a, and is extendable in the axial direction. Due to the expansion and contraction, the compressed air chamber 40 expands and contracts in the vertical direction.

The flat cylindrical body 22 of the fixed base 20 and the movable base 30
A pair of horizontally long bellows 51 constituting a pair of pressurized air chambers 50 are supported at positions facing each other in the horizontal direction. The horizontally long bellows 51 is made of an elastic member such as rubber as a base material, and has a substantially planar elliptical or oval cylindrical shape having a horizontal axis as shown in FIG. The horizontal diameter HD passing through the axis is larger than the vertical diameter VD passing through the axis. The horizontally long bellows 51 has sandwiching beads 51a at both ends in the axial direction, and a plurality of (two) semicircular cross-sections in the illustrated example are provided between the sandwiching beads 51a at both ends. (Waveform deformation portion) 51b is formed.

The sandwiching bead portion 51 of the horizontally long bellows 51
a, one of which is hermetically supported on the outer surface of the movable base 30;
The other is air-tightly supported on the inner surface of the flat cylindrical body 22.
That is, a horizontal bellows seat 34 having a bottomed cylindrical shape whose axis is oriented in the horizontal direction is fixed to the movable base 30 at a position facing the horizontal direction centering on the compressed air chamber 40. One holding bead portion 51 a of the horizontally long bellows 51 is hermetically supported between the bellows 51 and the retainer 35. The other sandwiching bead portion 51a of the horizontally long bellows 51 is
A pair of pressurized air chambers which are horizontally expandable and contractible between the fixed base 20 and the movable base 30 are supported between the fixed base 20 and the movable base 30 in an airtight manner on the inner surface of the flat cylindrical body 22 of the fixed base 20 via a retainer 24. 50 are formed.

The horizontally long bellows 51 having a horizontal diameter HD larger than the vertical diameter VD is easier to manufacture than a cylindrical bellows having a diameter of VD as a whole, and the flat tubular body 22 and the movable base 30
Is reduced to correspond to the vertical diameter VD of the horizontally long bellows 51.

The pressure air chamber 40 and the pair of pressure air chambers 50 are connected to a vertical pressure control system 61, a first horizontal pressure control system 62, and a second horizontal pressure control system 63, respectively, as shown in FIG. The vertical pressure control system 61, the first horizontal pressure control system 62, and the second horizontal pressure control system 63 are connected to a compressed air source 65 via a common manifold 64.

The vibration isolator having the above-described configuration regulates the pressure of the compressed air from the compressed air source 65 via the manifold 64 and the vertical pressure control system 61 according to the weight of the movable table 30 and the object placed on the movable table 30. The movable table 30 and the object to be mounted can be held in a floating state by introducing the movable table 30 and the mounted object into the vertical pressure air chamber 40.
0 can be prevented from being transmitted. At the same time, the pair of horizontal pressure air chambers 50 are connected to each other through the manifold 64, the first horizontal pressure control system 62, and the second horizontal pressure control system 63.
By similarly adjusting the pressure of the pressurized air from the compressed air source 65 and introducing the same, the horizontal movable table 30 can be prevented from vibrating.

FIG. 5 shows an example in which the horizontal bellows forming the pressurized air chamber 50 is a flat rectangular horizontal bellows 51R. The rectangular bellows 51R has a horizontal axis, and the horizontal diameter HD is larger than the vertical diameter VD, as in the horizontal bellows 51 of FIG.

In the embodiment described above, a pair of horizontal pressure air chambers 50 is provided, but a pair of two pressure air chambers may be provided in two orthogonal directions. Also in this embodiment, the pressure air chamber 50 is formed by the horizontally long bellows 51, 51R.

[0016]

As described above, according to the vibration damping device of the present invention, since the flexible airtight member constituting the pressure air chamber in the horizontal direction is constituted by the horizontally long bellows, the height can be reduced.

[Brief description of the drawings]

FIG. 1 shows an embodiment of a vibration damping device according to the present invention.
FIG. 2 is a cross-sectional view taken along line II of FIG.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is a perspective view showing the same part as a cross section.

FIG. 4 is a perspective view of a single horizontally long bellows forming a horizontal air chamber of the apparatus shown in FIGS. 1 to 3;

FIG. 5 is a perspective view showing another embodiment of the horizontally long bellows portion as a partial cross section.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Foundation 20 Fixed base 21 Bottom wall 22 Flat cylindrical body 23 Lower bellows retainer 24 Retainer 30 Movable base 31 Lower surface opening concave part 32 Upper bellows retainer 34 Horizontal bellows seat 35 Retainer 40 Pressure air chamber (vertical direction) 41 Bellows 50 Pressure air chamber (Horizontal direction) 51 Horizontal bellows (planar ellipse or oblong) 51R Horizontal bellows (planar square) 51a Nipping bead part 51b Semicircular part in cross section 61 Vertical pressure control system 62 First horizontal pressure control system 63 Second horizontal pressure Control system 64 Manifold 65 Compressed air source VD Vertical diameter HD Horizontal diameter

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tomomasa Fujita 1-840 Mitsuhashi-cho, Omiya-shi, Saitama Prefecture Fujikura Rubber Industries Co., Ltd. Omiya Plant (72) Inventor Hiroshi Kinta 1-840 Mitsuhashi-cho, Omiya-shi, Saitama F term (reference) in Omiya Plant of Industrial Co., Ltd. 3J048 AA02 AD01 BE02 CB19 DA05 EA13 3J069 AA24 AA31 CC40 DD50

Claims (2)

[Claims] 1. A pressure air chamber which can be expanded and contracted in a vertical direction and a pressure air chamber which can be expanded and contracted in a horizontal direction are formed between a fixed base and a movable base via flexible airtight members. In the vibration device, the flexible airtight member forming the horizontal pressure air chamber is formed in a cylindrical shape having a horizontal axis as a whole, and a horizontal diameter passing through the axis is a vertical diameter passing through the axis. An anti-vibration device comprising a horizontally long bellows having a larger diameter. 2. The vibration isolator according to claim 1, wherein the oblong bellows is a flat ellipse, an oval, or a square.