JP7086718B2 - Gas spring type anti-vibration device - Google Patents

Description

The present invention relates to a gas spring type vibration isolator.

As a gas spring type vibration isolator, for example, the one shown in Patent Document 1 is known. In the gas spring type vibration isolator of Patent Document 1, a piston that supports the load of the supported body is inserted into the opening on the upper surface of the case member, and the lower end surface of the piston is defined inside the case member. It is closed by an annular flexible member from the outer periphery of the piston to the periphery of the opening to elastically support the load of the supported body.

In the gas spring type vibration isolator of Patent Document 1, in order to suppress resonance caused by the piston, the outer peripheral side of the piston is held by a flexible member, and this flexible member is made of a high damping material. ..

Japanese Patent No. 3910023

However, the gas spring type vibration isolator of Patent Document 1 has a problem that resonance caused by a case member cannot be suppressed.

The present invention has been made in view of these points, and an object of the present invention is to suppress resonance caused by a case member.

In order to achieve the above object, in the present invention, a surging prevention member that comes into contact with the case member is provided to suppress resonance caused by the case member.

Specifically, in the first invention, a piston that supports the load of the supported body is arranged near the opening on the upper surface of the case member, and an annular flexible member is used between the piston and the opening. A gas spring type that is closed to define a gas chamber inside the case member and that holds the piston by the flexible member to form a gas spring that elastically supports the supported body. It is a vibration isolator and includes a surging prevention member made of an elastic body arranged so as to come into contact with the case member. The case member is formed in a bottomed tubular shape, and the bottom of the case member has a bottom. A tubular portion extending upward is formed, and the surging prevention member is formed in a tubular shape, is internally fitted to the case member, and is externally fitted to the tubular portion so as to be in contact with the tubular portion. It is characterized by being done .

According to the first invention, since the surging prevention member made of an elastic body arranged so as to come into contact with the case member is provided, resonance caused by the case member can be suppressed.

According to the first invention, since the surging prevention member is internally fitted to the case member, resonance caused by the case member can be suppressed by a simple configuration of internal fitting.

According to the first invention, the surging prevention member is externally fitted to the cylinder portion so as to come into contact with the cylinder portion, that is, is fitted between the case member and the cylinder portion, so that surging prevention is prevented. The member can be reliably brought into contact with the case member by its elastic rebound force. As a result, resonance caused by the case member can be reliably suppressed.

In the second invention, the piston that supports the load of the supported body is arranged near the opening on the upper surface of the case member, and the space between the piston and the opening is closed by the annular flexible member to close the case. It is a gas spring type vibration isolator that defines a gas chamber inside the member and holds the piston by the flexible member to form a gas spring that elastically supports the supported body. The case member is formed in a bottomed cylindrical shape, and the piston has a piston main body portion having a through hole in the vertical direction and a hollow portion communicating below the through hole, and the piston main body portion. A bottomed cylindrical downward extending portion extending downward and a hollow portion of the downward extending portion are arranged so as to extend in the vertical direction, while the lower end is pivotally supported by the bottom of the downward extending portion. , A support column portion whose upper end is located above the piston main body portion and receives the load of the supported body, and a surging prevention member made of an elastic body arranged so as to come into contact with the case member. The lower end is supported by the bottom of the case member, while the upper end is provided with a coil spring that supports the piston main body, and the surging prevention member is cylindrical. It is characterized in that it is formed in the case, is internally fitted to the case member, and is externally fitted to the coil spring so as to be in contact with the coil spring.

According to the second invention, since the surging prevention member made of an elastic body arranged so as to come into contact with the case member is provided, resonance caused by the case member can be suppressed.

According to the second invention, since the surging prevention member is internally fitted to the case member, resonance caused by the case member can be suppressed by a simple configuration of internal fitting.

In the second invention, since the surging prevention member is externally fitted to the coil spring so as to come into contact with the coil spring, resonance caused by the coil spring can also be suppressed.

The third invention is characterized in that, in the second invention, a protrusion is formed on the inner peripheral surface of the surging prevention member.

As described above, according to the present invention, resonance caused by the case member can be suppressed.

It is a perspective view of the precision vibration isolation table which concerns on Embodiment 1 of this invention. It is a vertical sectional view of the isolator which concerns on Embodiment 1. FIG. FIG. 2 is a diagram corresponding to FIG. 2 of the isolator according to the second embodiment. It is a horizontal sectional view of the surging prevention member which concerns on Embodiment 2. FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following description of preferred embodiments is merely exemplary and is not intended to limit the invention, its applications or its uses.

(Embodiment 1)
-Precision vibration isolation table-
FIG. 1 shows a precision vibration isolation table A using a gas spring type vibration isolation device (hereinafter referred to as an isolator) according to the first embodiment of the present invention. This precision vibration isolation table A is equipped with precision equipment (supported object) (not shown) such as a semiconductor inspection device, an electron microscope, and an optical measuring device, and insulates those devices from vibration from the floor. It is intended to be installed in a closed state. The precision vibration isolation table A includes an lower structure portion 1 installed on the floor surface, isolators 2, 2, ... Disposed at four corners on the upper surface of the lower structure portion 1, and isolators 2, 2, ... It consists of a mounting board 3 mounted on the upper part of the ...

The lower structural portion 1 is made by assembling structural members of a steel square pipe into a substantially rectangular shape, and has four legs 4, 4, ... Which extend in the vertical direction, and 2 adjacent to each other. A plan view surrounding the lower beam portions 5, 5, ... Which extend horizontally so as to connect the leg portions 4, 4 of the book to each other on the lower end side, and the outer periphery on the upper end side of the four leg portions 4, 4, ... The inner side surfaces are joined to the outer surfaces of the legs 4, 4, ..., and the upper surface is flush with the upper end surfaces of the legs 4, 4, .... It consists of the positioned upper beam portions 6, 6, .... Horizontal plates 7, 7, ... Are arranged from the upper end surface of each leg 4 to the upper surfaces of the upper beam portions 6, 6, ... Surrounding the outside thereof. Further, two moving casters 8, 8, ... Are arranged on the lower surfaces of the two facing lower beam portions 5, 5, and two casters 8, 8, ... For movement are arranged, and the lower end surface of each leg portion 4 is used for height adjustment. Levelers 9, 9, ... Are arranged.

-Isolator-
FIG. 2 shows the isolator 2. The isolator 2 includes a steel case member 11, a piston 13, a diaphragm 15 (flexible member), and a rubber surging prevention member 25. The isolator 2 comprises a gas spring in which the piston 13 is held by the diaphragm 15 to elastically support the supported object, and a gimbal mechanism is incorporated in the piston 13 to improve the horizontal spring characteristics in the vertical direction. It is very soft as well.

The case member 11 has a bottomed cylindrical shape and is said to have a height dimension larger than a horizontal width. The case member 11 has a disk-shaped base plate 11a (bottom of the case member), a cylindrical peripheral wall portion 11b, and a disk-shaped top plate 11c (upper surface of the case member). The lower end surface of the peripheral wall portion 11b is joined to the upper surface of the base plate 11a, while the upper end thereof is joined to the top plate 11c. Further, a circular opening 11d is formed in a substantially central portion of the top plate 11c so as to be substantially orthogonal to the axis Z in the vertical direction.

The piston 13 is arranged in the vicinity of the opening 11d of the top plate 11c to support the load of the supported body. The piston 13 has a donut-shaped piston body portion 14. The piston body 14 is made of an aluminum alloy, and a central hole (through hole) 14a having a circular cross section penetrates in the vertical direction along the axis Z, while the lower half of the outer circumference is slightly toward the lower end. A tapered surface 14b that is reduced in diameter is formed.

The diaphragm 15 is arranged so as to cover the tapered surface 14b on the outer peripheral side from the lower end surface 14c of the piston main body 14, further extend to the outer peripheral side, and close from there to the peripheral edge of the opening 11d. That is, the opening 11d of the case member 11 is closed by the diaphragm 15 and the piston main body 14, the gas chamber 16 is partitioned, and the lower end surface 14c of the piston main body 14 faces the gas chamber 16 and receives the air pressure. As a result, a gas spring that mainly supports the load in the vertical direction is configured.

The diaphragm 15 is made of a rubber bullet film formed by embedding a polyester fiber woven fabric as a reinforcing material. Once formed into a hat shape with a round hole in the center portion, the peripheral wall portion of the hat is curved in the middle to be downward. It is folded back into a deep dish shape. That is, in the diaphragm 15, an annular roll portion 15b that curves upwardly is formed continuously on the inner peripheral edge of the outer peripheral flange portion 15a corresponding to the flange portion of the hat, and the inner circumference of the roll portion 15b is formed. The edge portion extends below the outer peripheral flange portion 15a, and the inner peripheral flange portion 15c is formed further toward the inner peripheral side from there.

The inner peripheral flange portion 15c of the diaphragm 15 is adhered to the lower end surface 14c of the piston main body portion 14 and is firmly crimped to the piston main body portion 14 by the washer 17 from below. On the other hand, the outer peripheral flange portion 15a of the diaphragm 15 is adhered to the upper surface of the top plate 11c of the case member 11, and the tightening ring 18 disposed on the upper surface thereof is fastened to the top plate 11c by a bolt (not shown). As a result, it is firmly sandwiched between the lower surface of the tightening ring 18 and the upper surface of the top plate 11c.

The piston 13 has a bottomed cylindrical piston well 19 (downward extending portion) extending downward from the piston main body portion 14. The piston well 19 is formed so as to extend substantially vertically downward from the inner peripheral side thereof from the lower end surface 14c of the piston main body 14, and is a hollow portion 19a communicating with the lower side of the central hole 14a of the piston main body 14. have.

The piston well 19 is made of the same aluminum alloy as the piston main body 14, and the upper end thereof is a reduced diameter portion 19b screwed into the center hole 14a of the piston main body 14. Then, the male screw (not shown) screwed on the outer circumference of the reduced diameter portion 19b is screwed with the female screw (not shown) screwed on the inner circumference of the central hole 14a, whereby the upper end of the piston well 19 is formed. The side is firmly fastened to the piston main body 14 together with the washer 17. Further, the upper end of the hollow portion 19a of the piston well 19 communicates with the central hole 14a of the piston main body portion 14, while the lower end of the hollow portion 19a is closed by a disk-shaped steel cap 20. A well slag 20a that has been heat-treated to increase the surface hardness is formed on the upper surface in order to support the lower end portion of the support rod 22 as described later.

The piston 13 has a disk-shaped load disk 21 above the piston main body 14 so as to receive the load of the mounting board 3 and the mounted device (supported body) from above.

The piston 13 has a support rod (support column) 22. The upper end of the support rod 22 is fastened to the center of the lower surface of the load disc 21. The support rod 22 penetrates the central hole 14a of the piston main body 14 and the hollow portion 19a of the piston well 19 and extends vertically downward, and the hard ball 23 rotatably abuts on the well slug 20a at the lower end thereof. It is arranged like this. A rubber elastic ring 24 in which the core body 24a is embedded is extrapolated to the lower end side of the support rod 22, so that the lower end portion of the support rod 22 is always positioned on the axis Z. That is, the load disc 21 is pivotally supported at the bottom of the piston well 19 via the support rod 22 and is rotatable around an arbitrary axis in the horizontal direction with respect to the piston main body portion 14.

In the isolator 2, the gimbal piston including the load disk 21 and the piston main body 14 is supported by a gas spring to insulate the vertical vibration from the floor to the supported body on the mounting board 3, and the gimbal piston acts. Horizontal vibrations from the floor can also be substantially insulated.

The surging prevention member 25 is for suppressing resonance (surging) of the case member 11. The surging prevention member 25 is formed in a cylindrical shape so as to have a complementary shape to the peripheral wall portion 11b of the case member 11. The surging prevention member 25 is internally fitted to the case member 11 so that its outer peripheral surface is in contact with the inner peripheral surface of the peripheral wall portion 11b and its lower end surface is in contact with the base plate 11a. The vertical length of the surging prevention member 25 is such that it comes into contact with the portion of the case member 11 that becomes the antinode of resonance, and is, for example, slightly longer than half of the vertical length of the peripheral wall portion 11b.

A tubular portion 11e extending upward is integrally formed on the base plate 11a. The tubular portion 11e is formed in a cylindrical shape so as to have a complementary shape to the surging prevention member 25. The surging prevention member 25 is externally fitted to the tubular portion 11e so as to come into contact with the tubular portion 11e. That is, the position of the surging prevention member 25 is fixed by the tubular portion 11e. The length of the tubular portion 11e in the vertical direction is such that the surging prevention member 25 is surely brought into contact with the case member 11, and is, for example, the same length as the surging prevention member 25.

The inner diameter of the surging prevention member 25 is smaller than the outer diameter of the tubular portion 11e. Therefore, the surging prevention member 25 is externally fitted to the tubular portion 11e to generate an elastic rebound force.

(effect)
From the above, according to the present embodiment, since the surging prevention member 25 made of an elastic body arranged so as to come into contact with the case member 11 is provided, resonance caused by the case member 11 can be suppressed.

Further, according to the present embodiment, since the surging prevention member 25 is internally fitted to the case member 11, resonance caused by the case member 11 is suppressed inside the case member 11 by a simple configuration of internal fitting. be able to.

Further, according to the present embodiment, the surging prevention member 25 is externally fitted to the cylinder portion 11e so as to come into contact with the cylinder portion 11e, that is, is fitted between the case member 11 and the cylinder portion 11e. Therefore, the surging prevention member 25 can be reliably brought into contact with the case member 11 by its elastic rebound force. As a result, resonance caused by the case member 11 can be reliably suppressed.

(Embodiment 2)
The second embodiment is a modification of the configuration of the isolator 2, and has the same configuration as that of the first embodiment in other respects. Therefore, in the following description, duplicate description may be omitted for the same components as those of the first embodiment.

FIG. 3 shows the isolator 2 of the present embodiment.

The upper end of the support rod 22 abuts on the lower surface of the load disc 21 in a rollable and point-contact state, and has an upwardly convex spherical load receiving surface so as to receive the load of the supported body via the load disc 21. 22a is provided. That is, the load disc 21 is rollable with respect to the load receiving surface 22a at the upper end of the support rod 22, and is pivotally supported at the bottom of the piston well 19 via the support rod 22.

The isolator 2 further includes a coil spring 26. The coil spring 26 receives a part of the load of the supported body. The coil spring 26 surrounds the outer periphery of the piston well 19 of the piston 13 at a distance, and the lower end thereof is supported by the base plate 11a, while the upper end supports the piston body portion 14.

A boss portion 11f is formed on the upper surface of the base plate 11a by bulging, and a flange portion 19c is formed on the upper end of the piston well 19. The lower end of the coil spring 26 is arranged so as to surround the boss portion 11f of the base plate 11a, while the upper end thereof is in contact with the flange portion 19c at the upper end of the piston well 19. The boss portion 11f is for positioning the lower end of the coil spring 26.

The surging prevention member 25 is for suppressing the resonance of the case member 11 and the coil spring 26. The surging prevention member 25 is internally fitted to the case member 11 so that its outer peripheral surface is in contact with the inner peripheral surface of the peripheral wall portion 11b, while its inner peripheral surface (projection portion 25a described in detail later) is a coil spring. It is externally fitted to the coil spring 26 so as to come into contact with the 26. The length of the surging prevention member 25 in the vertical direction is such that the case member 11 and the coil spring 26 are in contact with each other at the antinodes of the resonance, and is, for example, substantially the same length as the coil spring 26.

FIG. 4 shows a horizontal cross section of the surging prevention member 25. The surging prevention member 25 is formed with a plurality of protrusions 25a, 25a, ... Of a protrusion shape extending in the vertical direction extending in the vertical direction on the inner peripheral surface thereof at intervals. Each protrusion 25a of the surging prevention member 25 is in contact with the coil spring 26.

That is, in the present embodiment, the surging prevention member 25 is externally fitted to the coil spring 26 so that its inner peripheral surface is in contact with the coil spring 26, so that not only the resonance caused by the case member 11 but also the coil Resonance caused by the spring 26 can also be suppressed.

Further, since the protrusions 25a, 25a, ... Of the surging prevention member 25 are in contact with the coil spring 26, the spring constant of the coil spring 26 is higher than that in the case where the entire inner peripheral surface of the surging prevention member 25 is in contact with the coil spring 26. Since the influence on the spring is small and the friction is small, it is easy to fit the outside.

(Other embodiments)
In each of the above embodiments, the isolator 2 has a gimbal mechanism incorporated in the piston 13, but the isolator 2 is not limited to this.

Further, in each of the above-described embodiments, the sirging prevention member 25 has a cylindrical shape whose length in the vertical direction is slightly longer than half the length in the vertical direction of the peripheral wall portion 11b of the case member 11, and its lower end surface is formed on the base plate 11a. Although they are in contact with each other, the present invention is not limited to this, and the case member 11 or the coil spring 26 may be fitted to the case member 11 or the coil spring 26 so as to be in contact with only the portion that becomes the antinode of the resonance of the case member 11 or the coil spring 26.

Further, in each of the above embodiments, the surging prevention member 25 is made of rubber, but the surging prevention member 25 is not limited to this, and may be made of, for example, a urethane resin, a thermoplastic elastomer, or a material having viscoelasticity.

Further, in the first embodiment, the peripheral wall portion 11b and the tubular portion 11e of the case member 11 and the surging prevention member 25 are cylindrical, but the present invention is not limited to this, and may be, for example, a square tubular shape.

Further, in the first embodiment, the surging prevention member 25 is fixed to the tubular portion 11e of the case member 11 by outer fitting, but the present invention is not limited to this, and for example, the surging prevention member 25 may be fixed with an adhesive. Further, a convex portion (protrusion or the like) is provided on one of the outer peripheral surface of the surging prevention member 25 and the peripheral wall portion 11b of the case member 11, and a concave portion (groove or the like) having a shape complementary to the convex portion is provided on the other, and the convex portion is provided as a concave portion. The surging prevention member 25 may be fixed to the case member 11 by fitting the surging prevention member 25 into the case member 11.

Further, in the first embodiment, the surging prevention member 25 is internally fitted to the case member 11, but the present invention is not limited to this, and the surging prevention member 25 may be externally fitted to the case member 11.

Further, in the first embodiment, the tubular portion 11e is formed integrally with the base plate 11a, but the present invention is not limited to this, and the tubular portion 11e may be an independent member not integrally with the base plate 11a.

Further, in the second embodiment, the boss portion 11f is formed on the upper surface of the base plate 11a, but the present invention is not limited to this, and the boss portion 11f may not be formed. That is, the lower end of the coil spring 26 may be in contact with the upper surface of the base plate 11a.

Further, in the second embodiment, the surging prevention member 25 is said to have four protrusions 25a, 25a, ..., But the number thereof is not limited to this, and may be, for example, three. Further, the protrusions 25a, 25a, ... May not be formed.

The present invention is useful as a gas spring type vibration isolator.

2 Isolator (gas spring type vibration isolator)
11 Case member 11a Base plate (case member)
11b Peripheral wall (case member)
11c Top plate (case member)
11d Opening 11e Cylinder 13 Piston 14 Piston body 14a Center hole (through hole)
15 Diaphragm (flexible member)
16 Gas chamber 19 Piston well (downward extension)
19a Hollow part 20 cap (downward extension part)
22 Support rod (support pillar)
25 Surging prevention member 26 Coil spring

Claims (3)

A piston that supports the load of the supported body is placed near the opening on the upper surface of the case member, and the space between the piston and the opening is closed by an annular flexible member, and a gas chamber is inside the case member. It is a gas spring type vibration isolator that constitutes a gas spring that elastically supports the supported body by holding the piston by the flexible member while defining the above.
A surging prevention member made of an elastic body arranged so as to come into contact with the case member is provided .
The case member is formed in a bottomed cylindrical shape.
A tubular portion extending upward is formed at the bottom of the case member.
The surging prevention member is a gas spring type anti-vibration device that is formed in a cylindrical shape, is internally fitted to the case member, and is externally fitted to the tubular portion so as to come into contact with the tubular portion . A piston that supports the load of the supported body is placed near the opening on the upper surface of the case member, and the space between the piston and the opening is closed by an annular flexible member, and a gas chamber is inside the case member. It is a gas spring type vibration isolator that constitutes a gas spring that elastically supports the supported body by holding the piston by the flexible member while defining the above.
The case member is formed in a bottomed cylindrical shape.
The piston
A piston body with a through hole in the vertical direction,
A bottomed cylindrical downward extending portion having a hollow portion communicating below the through hole and extending downward from the piston main body portion,
It is arranged so as to extend in the vertical direction in the hollow portion of the downward extending portion, and the lower end is pivotally supported by the bottom of the downward extending portion, while the upper end is located above the piston main body and is supported. It has a support column that receives the load of the body,
A surging prevention member made of an elastic body arranged so as to come into contact with the case member, and a surging prevention member.
It is provided with a coil spring that surrounds the outer periphery of the downward extending portion at a distance, and the lower end is supported by the bottom portion of the case member, while the upper end supports the piston main body portion.
The surging prevention member is a gas spring type vibration isolator which is formed in a cylindrical shape, is internally fitted to the case member, and is externally fitted to the coil spring so as to come into contact with the coil spring. In claim 2,
A gas spring type anti-vibration device in which a protrusion is formed on the inner peripheral surface of the surging prevention member.

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