JP2005220936A - Bidirectional damper and vibration-removing mount - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bidirectional damper having a damping function to both of a compression direction and an expansion direction. <P>SOLUTION: In the bidirectional damper having a visco-elasticity body, a lower visco-elasticity body R2 is put on a seat plate 5, a partition plate 8 is overlapped on the lower visco-elasticity body R2, and an upper visco-elasticity body R1 is put on the partition plate 8. An upper bracket 6 and a support plate 7 are arranged on both of an upper and lower positions at an upper position of the upper visco-elasticity body R1, the upper bracket 6 and the partition plate 8 are connected with each other by means of two expansion rods 9 and 9, and the support plate 7 and the seat plate 5 are connected with each other by means of two expansion-side rods 10 and 10. When force of a compression direction is applied on the upper bracket 6, the lower visco-elasticity body R2 is compressed. When force of an expansion direction is applied on the upper bracket 6, the upper visco-elasticity body R1 is compressed. Namely, this bidirectional damper has damping performance on both of directions. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a bidirectional vibration damper and a vibration isolation mount in which a load supporting element is combined with a bidirectional vibration damper that imparts resistance to vibrations in the vertical direction. The load supporting element referred to in the present invention is a coil spring or an air spring.

  An air spring as a load support element has been conventionally used as a device for adjusting the level of equipment, as well as a device for adjusting the level of equipment.

  There are two types of air springs: bellows type (bellows type) and diaphragm type. The latter is more stable against buckling, but the bellows type air spring is mainly used for the support structure of equipment. Used. The air spring controls the internal air pressure using a mechanical valve. When an air spring is used as a level adjuster for equipment, the level (height from the floor) is adjusted by adjusting the air pressure using the mechanical valve. Constantly controlled.

  Regardless of fluctuations in load and impact, keeping the level of a table on which equipment is mounted is particularly important for processing machines and measuring equipment. The air spring is assembled as a support structure on the four legs of the table. If an unbalanced load is applied to the four legs of such a table and the amount of air spring sinking differs between the legs, the table will be shaken or tilted, resulting in processing errors or measurement. It causes an error.

  When an air spring is used as a level adjuster, the mechanical valve is used to compensate for table level fluctuations. That is, when an unbalanced load is applied to the table and the air spring of at least one leg is compressed and sinks and the level falls below a specified level, the switch provided on the mechanical valve works, and high-pressure air flows through the piping into the bellows. The bellows are inflated to restore the level.

  Conversely, if the level of the table rises above a specified level, the mechanical valve releases the air in the bellows to lower the level to a specified level, and the table is always automatically adjusted to a constant level.

  In addition, when a table held at a specified level is subject to shock or load fluctuations and its level fluctuates, the air spring quickly converges the level fluctuation to the specified level. It is necessary to provide a damping mechanism. Conventionally, an air spring has been provided with an auxiliary tank as an attenuation mechanism, and an orifice is provided between the air chamber of the bellows and the auxiliary tank to provide attenuation to the air spring due to the viscous resistance of air. It was used.

  By giving damping to the air spring, it becomes possible to keep the resonance peak at the natural frequency low, it is possible to quickly converge the shaking of the table, quickly absorb the change in support load due to disturbance, and the fluctuation level Can be converged and kept at a prescribed level. The damping mechanism is not limited to the above structure, and the same effect can be obtained by adding an oil damper.

  However, in order to add damping to the air spring, it is necessary to install an auxiliary tank and an oil damper in addition to the bellows, which requires an installation space for the auxiliary tank and an oil damper and its control mechanism. There is a problem that the spring becomes large and the fluid control system requires troublesome adjustment.

  In order to solve such a problem, the inventor previously proposed an air spring (one of the previous examples of the vibration isolation mount according to the present invention) to which damping is applied without providing an auxiliary tank or an oil damper. .

  In this air spring, an air spring having a viscoelastic body, the air chamber of the air spring is formed by a bellows, and the viscoelastic body has a columnar shape and is mounted on the upper and lower plates of the bellows. It is installed in between and attenuates the fine vibration and amplitude in both the horizontal and vertical directions applied to the bellows.

  FIG. 6 shows the structure of the air spring. In FIG. 6, a bellows type (bellows type) air spring is used as the air spring 31, and a viscoelastic body 33 is provided in the air chamber R in the bellows 32. The viscoelastic body 33 is a solid that has not only the magnitude of stress but also the property that its rate of increase greatly affects the rate of increase of strain (see P1059, published by Maruzen Co., Ltd., 1985). An example of a material having this property is an epoxy resin.

  In this example, a coil spring 34 is used in addition to an air spring as a load support element, and a combination of a viscoelastic body 33 and a coil spring 34 is used as a vibration isolation mount 35. The example which has arrange | positioned the coil spring 34 and combined together inside and outside is shown.

  The bellows 32 is installed between the upper and lower plates 36 and 37, and the air chamber R is formed therein. The air spring 31 has four support structures for the table 38, and a lower plate 37 of the air spring 31 is installed on the floor, and the table 38 is mounted on the upper plate 36 directly or via a leg stand (not shown). On the table 38, the equipment 41 is mounted. Accordingly, the weight of the equipment 41 including the table 38 is added to each air spring 31, the coil spring 34 is compressed by receiving the weight, and the height of the table 38 is maintained at a predetermined level L. In FIG. 6, reference numeral 19 denotes a swing damper that absorbs energy in the horizontal direction. The swing damper 19 is attached to the lower plate 37 and the raised stay 21 and is in pressure contact with the bracket 20 lowered from the upper plate 36. As will be described later, the swing damper is also provided in the embodiment of the present invention.

  In FIG. 7, the air springs are installed as legs at the four corners of the lower surface of a table 38 on which a machine such as an XY stage is mounted. When the equipment 41 whose weight is moved on the table 38 by the movement of the machine such as the XY stage is mounted on the table 38, the weight of the table 38 including the fixed portion of the equipment 41 is M, and the equipment. If the weight of the portion 41 that moves position (hereinafter referred to as “position-moving component”) is m, the total weight applied to each air spring 31 incorporated in the four legs is that of the “position-moving component”. The total value of the load (m) and the weight (M) of the table 38 excluding the “position-moving component”. The weight (M) of the table 38 excluding “position-moving components” is supported exclusively by the coil spring 34, and the coil spring 34 is the same as the weight (M) of the equipment excluding “position-moving components”. Keeping the balance.

  Each bellows 32 of each air spring 31 contracts and expands individually under a load that varies depending on the position of the “position-moving component” in a state where the coil spring 34 is compressed by a certain amount. The table 37 is tilted (swayed) due to the expansion / contraction of the bellows 32 of the air spring 31 of each leg. The viscoelastic body 33 is efficiently attenuated in a short time. The magnitude of the load supported by the air pressure of the air spring 31, that is, the load (m) of the “position-moving component” is at most about 30% of the total weight.

  According to this air spring 31, it is only necessary to support the load (m) of the “position-moving component” of about 30% of the total weight at the maximum with the air pressure that is press-fitted into the bellows 32. It can be used at low air pressure, and a level adjustment function with excellent responsiveness can be realized.

  However, when the reciprocating equipment 41 as indicated by the arrow R moves rightward at a high speed, the right air spring sinks due to sudden weight addition, while the left air spring suddenly decreases its load. This causes the problem of rising. Regarding the sinking and lifting of the air springs 31, the table 38 is set by the mechanical valve 39 provided in each air spring 31 detecting an up and down change and exhausting or sucking the air springs 31. Try to maintain the height.

  The viscoelastic body 33 actually incorporated in the air spring has its damping performance set by compressing a certain amount by applying pressure in advance, and within the range of the damping performance, the air spring The table 38 is maintained at a constant height by the sinking of 31. However, when a sudden compressive force acts on the viscoelastic body 33 beyond the damping performance, the damping performance may deviate from the design value. In particular, when the air spring 31 is suddenly lifted, the viscoelastic body 33 does not have a function of suppressing the lift, and the table is accelerated by the restoring force of the viscoelastic body 33.

  Further, when the table 38 is lifted and fully lifted, if an overshoot occurs, the end of the rising table 38 may vibrate in the vertical direction thereafter. In such a case, since the damping performance of the viscoelastic body 33 is deteriorated, a damping force does not work, and there is a problem that the vibration of the air spring 31 is difficult to stop.

When the flying speed of the table 38 is faster than the restoring extension speed of the viscoelastic body 33, the air spring 31 is separated from the elastic body and the upper and lower stages of the viscoelastic body 33 are not constrained. When pushed up and raised to a level above the upper limit of the switch 40, the air in the air chamber is exhausted, and the table 38 tries to lower the level, but there is a discontinuity in the smooth movement (a state where it stops momentarily) This will affect the performance of the functions of the devices 41.
JP 63-30628 A No. 2003-148540

  The problem to be solved is that when a situation where the table suddenly floats up occurs, the compressed viscoelastic body recovers and expands and follows the change. In particular, the table may be vibrated, and particularly when the extension speed of the viscoelastic body cannot keep up with the flying speed of the table, smooth movement of the table is hindered.

  The present invention uses a viscoelastic body in which at least a part of the compressive force or tensile force is compressed even if a force in any direction is applied, and the vibration damping performance in both the compressive direction and the tensile direction. Is the main feature.

  The bidirectional vibration damper of the present invention can be used alone to cause damping in the compression direction, the pulling direction, or both the upward and downward directions, and further, a coil spring and / or air that is a load supporting element. In combination with a spring, it becomes an anti-vibration mount. Especially, the anti-vibration mount that combines a bidirectional damping damper with a coil spring and an air spring supports the corners of the table and suppresses sudden lifting of the table. As a result of this reaction, the amount of sinking of the table can be reduced, the response to the ups and downs of the table can be improved, and the table can be maintained at a predetermined set height. In addition, vibration control performance is always ensured, and hunting that tends to occur when the supply / exhaust amount of air supplied into or exhausted from the bellows of the air spring is increased with the aim of improving the response can be avoided.

  The bidirectional vibration damper of the present invention has two columnar viscoelastic bodies arranged in series and compressed in advance by a certain amount. Two viscoelastic bodies, a coil spring, and a bellows are combined in parallel to form an air spring. The two viscoelastic bodies are not necessarily attached to one of the two viscoelastic bodies when a force is applied to the table supported by the air spring and the table moves in the upward or downward direction. Compressed and exhibits damping performance. In addition, the bidirectional vibration damper of the present invention constitutes a vibration isolation mount for a structure or equipment in combination with a load support element that supports the weight of the structure or equipment. The load support element is a coil spring or an air spring, and a coil spring and an air spring can be used in combination as the load support element.

  Embodiments of the present invention will be described below with reference to the drawings. 1A and 1B, an example in which a vibration isolation mount is constructed by combining a bidirectional vibration damper 3 of the present invention with a coil spring 4 and an air spring 1 as load supporting elements will be described. The air spring 1 is a bellows type (bellows type) air spring.

  The bidirectional vibration damper 3 includes two columnar viscoelastic bodies R1 and R2 arranged in series. A viscoelastic body is a solid material such as an epoxy resin having a property that not only the magnitude of stress as described above but also its increasing speed has a great influence on the increasing speed of strain. The bodies R1 and R2 are combined such that one of the viscoelastic bodies is compressed when a force in the compression direction is applied, and the other viscoelastic body is compressed when a force in the tension direction is applied. Therefore, the damping performance can be expressed in any direction.

  In this embodiment, a coil spring 4 is arranged in parallel with the bidirectional vibration damping damper 3, and a combination of viscoelastic bodies R1, R2 and the coil spring 4 is used as a vibration isolation mount for the air spring.

  In the present invention, as shown in FIG. 2, the bidirectional vibration damper 3 includes upper and lower two columnar viscoelastic bodies R1 and R2, a seat plate 5, an upper bracket 6, a support plate 7, and a partition plate. 8 and a combination of the pull side and compression side rods 9 and 10. The lower viscoelastic body R2 is mounted on the seat plate 5, the partition plate 8 is stacked on the lower viscoelastic body R2, and the upper viscoelastic body R1 is mounted on the partition plate 8. The upper bracket 6 and the support plate 7 are arranged above and below the upper viscoelastic body R1, and the upper bracket 6 and the partition plate 8 are connected by two pull rods 9 and 9, The support plate 7 and the seat plate 5 are connected by two compression side rods 10 and 10.

  The upper bracket 6 has a quadrangular shape, and the pull-side rod 9 is attached to two opposite corners of the upper bracket 6. The support plate 7 is substantially rectangular, and the compression side rods 10 are attached to both ends thereof. In FIG. 3, the attachment positions of the two pull-side rods 9 and the attachment positions of the two compression-side rods 10 are shifted by 90 ° so as not to interfere with each other.

  As the bellows 2 of the air spring 1, one having 1 to 3 stages is frequently used. However, the first stage is harder in the horizontal direction, and the second and third stages are excellent in the stretchability in the vertical direction. Also in this embodiment, a two-stage rubber bellows in which the hardness in the horizontal direction is complemented by a coil spring is used because it is too soft in the horizontal direction and is likely to buckle.

  The air spring 1 is a support structure installed at the four corners of the table 11, and the bellows 2 of the air spring 1 is installed between the upper and lower plates 12, 13 and the lower plate 13 is installed on the floor F, and the coil The spring 4 and the bidirectional vibration damper 3 according to the present invention are installed in parallel with the bellows 2 between the upper and lower plates 12 and 13. In FIG. 1 (1), in this embodiment, coil springs 4 and 4 are installed at two locations on a diagonal line, and the bidirectional vibration damper 3 is installed in a space formed on one side of the bellows 2. .

  When installing the bidirectional vibration damper 3, the seat plate 5 is fixed to the lower plate 13 and the upper bracket 6 is fixed to the lower surface of the upper plate 12 with the upper and lower viscoelastic bodies R1 and R2 slightly compressed. To do. As shown in FIG. 2, a screw rod 14 is screwed into the support plate 7, and when the cap 15 placed on the top of the upper viscoelastic body R1 is pressed by the screw rod 14, the upper viscoelasticity is determined by the amount of screwing. The body R1 is compressed, and at the same time, the lower viscoelastic body R2 is compressed by the same amount.

  Thus, the upper and lower viscoelastic bodies R1 and R2 are fitted between the upper and lower plates 12 and 13 of the air spring 1 supporting the table 11 in a state where the viscoelastic bodies R1 and R2 are compressed by a certain amount. The procedure for compressing the upper and lower viscoelastic bodies R1, R2 is not limited to this. For example, since the lower viscoelastic body R2 is compressed by the pressure determined by the weight received from above and the repulsive force of the coil spring, the upper and lower viscoelastic bodies R1 and R2 are further reduced by the screwing amount of the screw rod 14. It is also possible to adjust the compression amount so that there is no difference in the compression amount between the upper and lower viscoelastic bodies R1, R2, or a certain difference in the compression amount.

  In FIG. 4, the table 11 is placed on the upper plate 12 directly or via a leg stand (not shown), and devices 22 are mounted on the table 11. Accordingly, the weight of the equipment 22 including the weight of the table 11 is added to each air spring 1, the coil spring 4 is compressed by receiving the weight, and the height of the table 11 is maintained at a specified level L.

  High-pressure air is supplied into the bellows 2 of the air spring 1 through a mechanical valve 16, the air pressure in the bellows 2 is controlled by the mechanical valve 16, and the level of the table 11 (height from the floor) is constant (a prescribed level). L). That is, when the table 11 is shaken due to the load movement or impact of the equipment 22 or the reaction force during operation and the level of the table 11 is lowered from the specified level L to Ll, the switch 17 provided in the mechanical valve 16 is pushed down. Then, high-pressure air is supplied into the bellows 2 and expands, and the table 11 is pushed upward.

  When the table 11 is pushed up and its height rises to a level Lh that is equal to or higher than the upper limit of the switch 17, the air in the bellows 2 is released through the drain 18, the bellows 2 is compressed and deformed, and the table 11 may be lowered. Is automatically adjusted to the specified level L.

  When the device 22 moves due to a delay in the automatic adjustment response, the vertical load received by the bellows 2 fluctuates, the internal pressure changes, and the table 11 Moves up and down greatly immediately after movement. In this case, when the table 11 rises, as shown in FIG. 5B, the partition plate 8 fixed to the pulling side rod 9 rises together, so that the upper viscoelastic body R1 is compressed. On the contrary, when the table is lowered, as shown in FIG. 5A, the partition plate 8 is similarly lowered and the lower viscoelastic body R2 is compressed. In this way, the viscoelastic bodies R1 and R2 are resistant to any movement in the vertical direction of the table, and exhibit a damping effect.

  Further, since the horizontal movement of the table 11 causes a relative horizontal shift with respect to the seat plate 5 and the support plate 7 in which the partition plate 8 is connected by the compression rod 10, shearing occurs in the viscoelastic bodies R1 and R2. Power is exerted and the damping effect is demonstrated. As described above, the bidirectional damper according to the present invention is converted into a relative table behavior even if it is an exogenous minute vibration received from the floor, so that the minute vibration propagating from the floor synthesized in both the vertical and horizontal directions is prevented. However, the damping effect can be obtained by the viscoelastic bodies R1 and R2.

  In addition, prior to installation between the upper and lower plates 12 and 13, the compression amount is given to the upper and lower viscoelastic bodies R1 and R2 in advance when the upper bracket 6 is pushed down or pulled up. This is because when the viscoelastic body R1 (R2) is compressed, the other viscoelastic body R2 (R1) follows the change. If the viscoelastic bodies R1 and R2 are not compressed in advance, when one of the viscoelastic bodies is compressed, the other viscoelastic body cannot follow the change, and the viscoelastic body R1 or R2 is separated from the partition. A gap is generated between the plate 8 and the air spring 1 pushed up or pulled down by the vertical movement of the table becomes a discontinuous point when returning to the level L, and an impact is generated on the table 11. According to the present invention, as long as the speed of vertical movement of the table is not extremely high, no gap is generated, and the fluctuation of the table can be smoothly attenuated to maintain a constant level L.

  Further, also in this embodiment, the swing damper 19 is assembled as means for absorbing the energy of the horizontal relative displacement generated between the upper plate 12 and the lower plate 13. That is, the bracket 20 is lowered on the upper plate 12, the stay 21 is raised on the lower plate 13, and the swing damper 19 supported by the stay 21 is brought into pressure contact with the bracket 20. Since the displacement in the horizontal direction occurs in the biaxial direction, in FIG. 1 (1), a rocking damper 19 that absorbs the energy of the relative displacement is installed on the two planar axes (XY plane).

  The swing damper 19 is a rod-like viscoelastic body. The swing damper 19 is held across the bracket 20 and the stay 21 and is interposed between the upper plate 12 and the lower plate 13 in a horizontal posture, so that the table 11 receives a reaction force of the apparatus and the horizontal surface ( In the case of a large swing in the X direction or the Y direction on the XY plane, resistance is given to the table 11 by the viscous property of the swing damper 19. Thereby, the energy of shaking of the table 11 is absorbed, and the shaking of the table 11 can be stopped quickly.

However, in the present invention, by combining the bidirectional vibration damper and the air spring, the shearing force of the upper and lower viscoelastic bodies acts in the horizontal direction, so that the vibration damping performance in the horizontal direction can be greatly improved. Is possible.
As described above, in the embodiment, a description has been given of a vibration isolation mount in which a combination of a coil spring and an air spring is used as a load support element, and a bidirectional vibration damper is combined with the load support element by this combination. Of course, the load supporting element is not limited to the combination of a coil spring and an air spring, but the bidirectional vibration damper according to the present invention is applicable to a vibration isolation mount using a combination of a coil spring and an air spring and a bidirectional vibration damper. The function of the anti-vibration mount can be exerted by acting the damping of both directions. Further, in the embodiment, for the sake of easy understanding, the example in which the damping is applied in the vertical direction using the upper and lower laminated viscoelastic bodies has been described, but the damping direction is not necessarily limited to the vertical direction. The vibration damping damper can be used in a horizontal posture or an inclined posture by using the seat plate on the fixed side and the upper bracket on the movable side.

  The bidirectional vibration damping damper according to the present invention can greatly contribute to the improvement of the performance of the equipment because the table does not shake even if the movement speed of the equipment moving on the table is improved in combination with the air spring. In addition, since the bidirectional vibration damper is unitized, it can be used as a bidirectional vibration isolation mount in any combination with a coil spring or air spring, and it can be added to a device supported by a spring mount with an air jack. Can be installed.

(A) is a top view which shows one Embodiment of the air spring by this invention, (b) is the sectional view on the AA line of (a). It is a figure which shows the example which applied the bidirectional | two-way damping damper of this invention to the anti-vibration mount of the air spring, (a) is a BB sectional drawing of Fig.1 (1) (a), (b) is ( It is a side view of a). It is a figure which shows the structure of the bidirectional | two-way damping damper of this invention, (a) is a front view, (b) is a side view, (c) is a top view, (d) is the DD sectional view of (a). FIG. It is a perspective view which shows the positional relationship of the tension | pulling side rod and compression side rod of a bidirectional vibration damper. It is a figure which shows operation | movement of the air spring of this invention. It is a figure which shows the state by which the upper and lower stage viscoelastic body was compressed with the load. It is a figure which shows the structure of the conventional air spring. It is a figure which shows operation | movement of the conventional air spring.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Air spring 2 Bellows 3 Bidirectional vibration damper 4 Coil spring 5 Seat plate 6 Upper bracket 7 Support plate 8 Partition plate 9 Pull side rod 10 Compression side rod 11 Table 12 Upper plate 13 Lower plate 14 Screw rod 15 Cap 16 Mechanical valve 17 Switch 18 Drain 19 Oscillating damper 20 Bracket 21 Stay 22 Equipment

Claims (9)

A bidirectional vibration damper having a viscoelastic body,
A viscoelastic body is one that compresses at least part of the force in any direction of compressive force or tensile force, and exhibits damping performance in both the compressive and tensile directions. A two-way vibration damper characterized by being. A bidirectional vibration damper having a set of two columnar viscoelastic bodies,
The two columnar viscoelastic bodies are such that when a force in the compression direction is applied to the set of viscoelastic bodies, one of the viscoelastic bodies is compressed, and when a force in the tensile direction is applied, the other viscoelastic body The two-way vibration damper is characterized by being combined so as to be compressed. A bi-directional vibration damper composed of a combination of two columnar viscoelastic bodies, a seat plate, an upper bracket, a support plate, a partition plate, and a tension side and compression side rod,
The lower viscoelastic body is mounted on the seat plate, the partition plate is stacked on the lower viscoelastic body, the upper viscoelastic body is mounted on the partition plate,
The upper bracket and the support plate are arranged above and below the upper viscoelastic body,
The upper bracket and the partition plate are connected by a pull rod,
The support plate and the seat plate are connected by a compression side rod,
The bidirectional vibration damper according to claim 2, wherein the seat plate is fixed, and the compression force and the tensile force are applied to the upper bracket.   4. Both according to claim 3, wherein the attachment position of the pull-side rod attached to the upper bracket and the attachment position of the compression-side rod attached to the support plate are shifted in phase so as not to interfere with each other. Anti-vibration damper. The support plate has pressure adjusting means,
4. The bidirectional vibration damper according to claim 3, wherein the pressurizing adjustment means pressurizes and compresses the upper and lower viscoelastic bodies. A vibration isolation mount comprising a combination of the bidirectional vibration damper according to claim 1, 2, 3, 4 or 5, and a load support element,
The vibration isolation mount, wherein the load supporting element is a coil spring, and the coil spring is disposed in parallel with the bidirectional vibration damper. A vibration isolation mount comprising a combination of the bidirectional vibration damper according to claim 1, 2, 3, 4 or 5, and a load support element,
The vibration isolation mount, wherein the load supporting element is an air spring, and the air spring is disposed in parallel with the bidirectional vibration damper. A vibration isolation mount comprising a combination of the bidirectional vibration damper according to claim 1, 2, 3, 4 or 5, and a load support element,
The load supporting element is a combination of a coil spring and an air spring, and the coil spring and the air spring are arranged in parallel with the bidirectional vibration damper.   The air spring has a bellows installed between the upper and lower plates, the lower plate is installed on the floor, the upper plate supports the table, and the bidirectional vibration damper is installed between the upper and lower plates. The vibration isolation mount according to claim 7, wherein the vibration isolation mount is installed in parallel with the bellows 2.

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