JP2007247840A - Gas-spring vibration isolator and method of adjusting same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration isolator A which supplies/exhausts air directly to/from an air chamber S depending on a change in the supporting height of an air spring 2 by changing over a supply/exhaust flow amount at a proper timing compatible with the condition of supplying/exhausting air to actualize quick reset to a reference height while sufficiently suppressing overshoot. <P>SOLUTION: A throttle valve 33 is provided in a first supply/exhaust duct 30 for supplying/exhausting air to the air chamber S of the air spring 2 via a levelling valve 31. In a second supply/exhaust duct 36 which is branch-connected to the first supply/exhaust duct 30 on the downstream side of the throttle valve 33, a control valve 37 is arranged which consists of a pressure reducing valve. With the reaction of the control valve 37 on differential pressure between the upstream and downstream sides of the throttle valve 33, pressure air is supplied to the air spring 2 when predetermined pressure or higher is on the throttle upstream side than on the downstream side and it is exhausted from the air spring 2 when predetermined pressure or higher is on the downstream side than on the upstream side. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a gas spring type vibration isolator that elastically supports various precision devices such as liquid crystal related manufacturing apparatuses via a gas spring, and more particularly, to a gas spring through a mechanical leveling valve. It relates to a gas chamber that supplies and discharges gas directly.

  Conventionally, as this type of vibration isolator, for example, as described in Patent Document 1, a vibration isolator having a loom supported by a plurality of air springs is known. In this device, adjustment (leveling adjustment) for keeping the gantry horizontal is performed by supplying pressurized air to individual air springs, exhausting, etc. For example, with the operation of the loom, When the shared load increases and the supporting height decreases, the lever of the leveling valve is pushed down, and the pressurized air is supplied directly to the air chamber.

  Then, if pressurized air is supplied to the air chamber until the lever of the leveling valve reaches the reference height, the supply amount of this pressurized air becomes larger than necessary. The support height once becomes higher than the reference height (overshoot), thereby raising the lever of the leveling valve and discharging the air in the air chamber. After the air supply / discharge to / from the air chamber is repeated several times in this way, the support height of the air spring converges to the reference height, and the gantry is kept horizontal.

  At that time, as the amount of pressurized air supplied to the air chamber excessively increases as described above, the amount of overshoot of the support height of the air spring increases, so it takes time to converge to the reference height. Further, when the vibration isolator is suddenly displaced by overshoot, there is a possibility that the device malfunctions.

  Therefore, in the above-mentioned conventional example, a flow control valve is provided in the passage for supplying pressurized air to the air spring, and the flow of the circulating air is reduced to a small amount, thereby excessive air to the air chamber. The supply is reduced to suppress overshoot. As a result, convergence to the reference height is accelerated, and it is possible to prevent the vibration isolator from being suddenly displaced by overshoot.

  However, if the flow rate of pressurized air to the air spring is reduced to a small amount, the air supply delay will inevitably increase. There is a possibility that the tilt of the gantry becomes large and causes a problem of interference. Also, the time for which the pedestal is tilted becomes longer. For example, when a precision instrument such as a liquid crystal panel manufacturing apparatus is mounted, the instrument may not be operated while it is tilted. This is not desirable because it causes excessive extension.

  In this regard, for example, the leveling valve (automatic leveling device) described in Patent Document 2 incorporates two valve bodies, and the change in the support height of the air spring (the tilt of the gantry) is large, and the lever operating amount When air pressure is large, air is supplied from both valve bodies to the air spring, while when the change in the support height is small and the lever operation amount is small, one valve body is closed and air is supplied only from the other valve body. It comes to supply.

If such a leveling valve is used, air can be supplied at a relatively large flow rate to the air spring via the two valve bodies when the change in the support height of the supported body by the air spring is large. The spring can be returned to the reference height relatively quickly, and when close to the reference height, one valve body is closed and the air supply amount is reduced, so that overshoot can be suppressed.
Japanese Utility Model Publication No. 5-30180 Japanese Patent No. 2814077

  However, in the latter conventional example, since the leveling valve has two built-in valve bodies, the structure is complicated, and the opening / closing timing of the two valve bodies is determined uniformly by the amount of operation of the lever. Because the timing of switching from a large flow rate to a small flow rate is determined by this, it is not necessarily necessary to eliminate excessive air supply, sufficiently suppress overshoot, and sufficiently shorten the return time to the reference height. I can't say that.

  That is, in order to suppress excessive supply of air to the air spring, depending on the supply state, for example, when the flow rate of air is large, it is necessary to close one of the valve bodies at an earlier timing. Thus, if the timing is determined only by the amount of lever operation, this is too late than the appropriate timing and it becomes oversupply, or conversely, it is too early than the appropriate timing and the supply delay becomes large. It is.

  The present invention has been made in view of such points, and an object of the present invention is to supply and discharge gas in a gas spring type vibration isolator that supplies and discharges gas directly to and from a gas chamber. By devising the configuration for this purpose and switching the supply flow rate at an appropriate timing corresponding to the gas supply / exhaust state to the gas chamber, the return time of the height can be sufficiently shortened while sufficiently suppressing overshoot. There is.

  In order to achieve the above object, according to the present invention, the first supply / exhaust passage for supplying / exhausting gas to / from the gas chamber via the leveling valve is provided with a throttle portion, while separately supplying / exhausting gas to / from the gas chamber. A second supply / exhaust passage is provided, and a control valve interposed in the second supply / exhaust passage is operated in accordance with the pressure difference between the upper and lower portions of the throttle portion.

  Specifically, in the first aspect of the invention, the supported body is elastically supported by the gas spring, and a mechanical leveling valve is provided in the first supply / exhaust passage that opens toward the gas chamber of the gas spring. Then, the object is a gas spring type vibration isolator in which gas is directly supplied to and discharged from the gas chamber in accordance with the change in the height of the supported body.

  The first supply / exhaust passage is provided with a throttle portion for restricting the flow of gas between the leveling valve and the gas chamber, and the first supply / exhaust passage is capable of supplying / exhausting gas to / from the gas chamber without passing through the throttle portion. The second supply / discharge passage receives pilot pressure from the upstream side (leveling valve side) and the downstream side opposite to the throttle portion, and the upstream pilot pressure is downstream. When the gas pressure is supplied to the gas chamber when it is higher than a predetermined level, the control valve is provided so as to exhaust the gas from the gas chamber when the downstream pilot pressure is higher than the upstream side by a predetermined level.

  With the above-described configuration, for example, when a device that is a supported body is operated, a load on the gas spring that supports the device increases, and when the support height is lowered, the leveling valve is operated and the gas is first. The gas chamber is supplied directly from the supply / discharge passage. At this time, if the gas pressure on the upstream side is higher than that on the downstream side in the throttle portion of the first supply / exhaust passage and the pressure difference between them is greater than or equal to a predetermined value, the control valve is actuated and the Gas is supplied to the gas chamber.

  Then, by supplying gas at a large flow rate by both the first and second supply / discharge passages, the internal pressure of the gas spring rises quickly and its supporting height also increases, but it becomes the reference height. Before reaching, the gas pressure on the downstream side of the throttle portion of the first supply / exhaust passage also increases, the differential pressure with respect to the upstream side decreases, and the operation of the control valve of the second supply / exhaust passage stops. After that, the gas is supplied from the first supply / exhaust passage only, that is, by the restricting portion, at a small flow rate.

  In other words, the gas supply flow rate is increased according to the increase in the internal pressure of the gas spring instead of the operating amount of the lever of the leveling valve, in other words, at an appropriate timing corresponding to the gas supply state to the gas chamber. Since the flow rate can be switched from low to low, the supply delay to the gas chamber can be reduced as much as possible, the return time to the reference height can be sufficiently shortened, and the excess supply of gas can be eliminated to overshoot. Can be sufficiently suppressed.

  The appropriate timing for such flow rate switching varies depending on, for example, the volume of the gas spring, its damping characteristics, the cross-sectional area and length of the first and second supply / exhaust passages, the supply pressure of the gas pressure source, and the like. Changes depending on the weight of the device as a supported body, the height of the center of gravity, a change in load due to its operation, and the like.

  Therefore, it is preferable that the throttle portion provided in the first supply / exhaust passage as described above is a variable throttle that can change the throttle amount (the invention of claim 2). If it carries out like this, the timing which the control valve of a 2nd supply / exhaust passage act | operates can be changed easily by changing the differential pressure of the up-and-down by change of the amount of restriction. Therefore, if the mounted device is actually operated, and the amount of support of the gas spring is changed accordingly, the amount of adjustment of the variable throttle can be adjusted. In addition, it can be set only by adjusting the aperture amount.

  More specifically, the cross-sectional area of the throttle portion is preferably set to a range of 5 to 55% of the cross-sectional area of the other part of the first supply / exhaust passage (Invention of Claim 3). That is, if the pressure is less than 5%, the throttle is too strong and the differential pressure becomes too large, so it is difficult to switch to a small flow rate, and the pressure fluctuation (overshoot) in the gas chamber increases due to excessive supply. If it is 55% or more, the throttle is too loose and it is difficult for differential pressure to occur. Therefore, the control valve does not operate easily, and even if it operates once, it immediately stops and switches to a small flow rate, and the gas supply delay This is because it becomes larger.

  Further, it is preferable that the second supply / exhaust passage communicates with the first supply / exhaust passage on the downstream side of the throttle portion, so that the gas spring is provided only for the second supply / exhaust passage. There is no need to provide a through passage, and the structure can be simplified.

  In such a case, when the gas is supplied from the second supply / exhaust passage to the downstream side of the throttle portion of the first supply / exhaust passage, there is a possibility that the gas pressure on the downstream side rises and the differential pressure from the upstream side is suddenly reduced. However, the control valve of the second supply / discharge passage is constituted by a pressure reducing valve in which the downstream gas pressure communicating with the first supply / discharge passage is adjusted in accordance with the pilot pressure from the upstream side of the throttle portion. If so (the invention of claim 4), it can be set so that the gas pressure on the downstream side does not become so high, the vertical pressure difference of the throttle portion does not rapidly decrease due to the supply of gas from the second supply and discharge passage, Therefore, the stability of the operation of the pressure reducing valve that responds to the differential pressure is ensured.

  The present invention is also an adjustment method for adjusting the gas spring vibration isolator according to claim 1, and first, a variable throttle that can change a throttle amount is used as a throttle portion of the first supply / discharge passage. Then, by operating the device that is the supported body, measure the change in its height position, adjust the aperture amount of the variable aperture based on this measurement result, and then change this to a fixed aperture that cannot change the aperture amount It is to exchange.

  According to this method, an inexpensive fixed throttle is adopted as the throttle portion of the gas spring type vibration isolator, and the variable throttle is used for the adjustment while reducing the cost. The same effect as the invention can be obtained. In other words, even when there are many factors that affect the timing of switching the supply flow rate to the gas spring in the vibration isolation device, it is possible to easily set the timing appropriately by simply adjusting the throttle amount of the variable throttle.

  As mentioned above, according to the gas spring type vibration isolator which concerns on this invention, in the gas spring type vibration isolator which was made to supply and discharge gas directly to a gas chamber, the 1st supply / exhaust path where the leveling valve was interposed Since the throttle part is provided with a control valve in a second supply / exhaust passage that is different from the throttle part, and this is operated according to the differential pressure in the upper and lower sides of the throttle part, the supply of gas to the gas spring The flow rate can be switched from a large flow rate to a small flow rate at an appropriate timing corresponding to the supply / discharge state, thereby sufficiently reducing the return time of the height while sufficiently suppressing overshoot. .

In particular, a variable throttle is used as the throttle section of the first supply / exhaust passage, and an actually mounted device is operated to adjust the throttle amount within a predetermined range according to the change in the support height of the gas spring. By doing so, even in a system having many factors that affect the timing of switching the supply flow rate to the gas spring, it can be easily set to an appropriate timing.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that the following description of the preferred embodiment is merely illustrative in nature, and is not intended to limit the present invention, its application, or its use.

  1 and 2 show a schematic configuration of a vibration isolation device A according to an embodiment of the present invention. As shown in FIG. 3, the vibration isolator A usually has a plurality of mounting boards 1 on which devices D such as liquid crystal related manufacturing apparatuses are mounted (three in the example in the figure, but four or more). It is an air spring type that is elastically supported by the air spring 2 (gas spring), and the height of the mounted device D and the mounting board 1 that are the supported bodies is kept substantially constant. In order to sag, a pneumatic circuit 3 is provided for supplying or exhausting air directly to the air chamber S (gas chamber) of the air spring 2. In FIG. 2, elements of the pneumatic circuit 3 are represented by symbols.

  The air spring 2 is of the bellows type in the example of the figure, and is a base plate 20 disposed on the floor or the like, and a top plate 21 that is spaced apart above the top plate 21 so that the lower surface of the mounting board 1 contacts the upper surface. And a lantern-shaped one-step bellows 22 that is interposed between them and divides the air chamber S inside. The top plate 21 has a supply / exhaust port 23 formed so as to open toward the air chamber S on the lower surface thereof, and a connector 24 is fitted to the other end of the supply / discharge port 23 opened on the side surface of the top plate 21. This is connected to the downstream end of the first supply / discharge line 30 of the pneumatic circuit 3.

  In the illustrated example, a damping mechanism 25 is disposed in the air chamber S of the air spring 2. This is because the damping plate 25b immersed in the silicone oil in the case 25a is connected to the top plate 21 of the air spring 2 by the shaft 25c, and resistance due to the viscosity of the silicone oil is given to the displacement of the top plate 21. Is.

  The pneumatic circuit 3 includes a first supply / exhaust pipe 30 for supplying pressurized air directly from an air pressure source (not shown) to the air chamber S of the air spring 2. 30 is provided with a leveling valve 31 that supplies pressurized air to the air spring 2 in accordance with the vertical movement of the mounting board 1 or exhausts the air from the air spring 2. The first supply / exhaust conduit 30 is provided with a first branch portion 32, a throttle valve 33, and a second branch portion 34 in order from the leveling valve 31 toward the air spring 2.

  In this example, the leveling valve 31 is a mechanical three-port proportional switching valve whose position is switched by an external force. The leveling valve 31 is provided so as to be pivotable in the vertical direction. A supply / exhaust port 31b (A port) for supplying and discharging air between the lever 31a for detecting the position and the air spring 2, and a supply port 31c (P port) for receiving pressurized air from an air pressure source (not shown) ) And an exhaust port (R port) (not shown).

  That is, the supply port 31c is connected to the downstream end of a pipe 30a for supplying compressed air from an air pressure source such as an air pump or a reservoir tank (not shown), while the supply / exhaust port 31b is connected to an air spring. 2 is connected to the upstream end of a pipe 30 b for supplying and discharging air, and the downstream end of the pipe 30 b is connected to the first branch portion 32.

  When the height of the mounting board 1 becomes lower than a preset height (reference height) and the lever 31a rotates downward, the leveling valve 31 is switched to the air supply position shown in FIG. The supply port 31c (P port) and the supply / exhaust port 31b (A port) communicate with each other so that pressurized air is supplied from the air pressure source to the air chamber S of the air spring 2.

  On the other hand, if the mounting board 1 becomes higher than the reference height and the lever 31a rotates upward, the leveling valve 31 is switched to the exhaust position, and the supply / exhaust port 31b (A port) and the exhaust port (not shown) are not shown. R port) is communicated, and air is discharged from the air chamber S of the air spring 2 to the atmosphere. When the mounting board 1 is at a substantially reference height and the lever 31a is not turned up and down, the leveling valve 31 does not supply or exhaust air.

  As described above, the downstream end of the upstream pipe 30b is connected to the first branch portion 32, and the upstream end of the pipe 30c leading to the throttle valve 33 is connected. A pilot line 35 for supplying pilot pressure is connected. In the example shown in the figure, the throttle valve 33 is a variable throttle valve that can change the throttle amount by adjusting the position of the needle with the adjusting screw 33a. The throttle valve 33 is connected to the downstream end of the pipe 30c, and is connected to the second branch portion. 34 is connected to the upstream end of the pipe 30d.

  Further, the downstream end of the pipe 30d is connected to the second branch portion 34, and the upstream end of the pipe 30e leading to the connector 24 of the air spring 2 is connected. Further, the leveling valve 31 and the throttle valve 33 are connected to the second branch portion 34. The downstream end of the second supply / exhaust pipe 36 for supplying / exhausting air to / from the air chamber S of the air spring 2 is connected without intervention. That is, the second supply / discharge pipe 36 is connected to the air chamber S of the air spring 2 via the pipe 30 e of the first supply / discharge pipe 30 downstream of the throttle valve 33 and the supply / discharge port 23. Yes.

  An air pressure control valve 37 for supplying and discharging air to the air spring 2 according to the vertical differential pressure of the throttle valve 33 is interposed in the second supply / exhaust pipe 36 in conjunction with the leveling valve 31. In this example, the air pressure control valve 37 is composed of a pressure reducing valve, connected to the second branch portion 34 by a pipe 36a, and a supply / exhaust port 37a (A port) for supplying and discharging air to and from the air spring 2, and a pipe Pilot port 37d (p1 port) to which a supply port 37b (P port) that receives supply of pressurized air from an air pressure source (not shown) through 36b, an exhaust port 37c (R port), and a pilot line 35 is connected And.

  The air pressure control valve 37 receives a pilot pressure from the upstream side of the throttle valve 33 via the pilot pipe line 35 and also receives a pilot pressure from the downstream side of the throttle valve 33 via the pipe 36a. In response to the differential pressure (up and down differential pressure of the throttle valve 33), either the supply of pressurized air from the supply / exhaust port 37a or the exhaust from the exhaust port 37c is performed, whereby the supply / exhaust port 37a is operated. The air pressure on the (A port) side is adjusted according to the pilot pressure from the upstream side of the throttle.

  That is, when the leveling valve 31 of the first supply / exhaust pipe 30 is in the supply position, and thereby the pressurized air is supplied to the air spring 2 through the first supply / exhaust pipe 30, the throttle valve 33 Although the upstream gas pressure is higher than that on the downstream side, if this differential pressure is greater than or equal to a predetermined value, the supply / exhaust port 37a and the supply port 37b of the control valve 37 are connected to each other, and the second supply / exhaust conduit The pressurized air is supplied to the air spring 2 also by 36.

  On the other hand, when the leveling valve 31 is in the exhaust position and is thereby exhausted from the air spring 2 via the first supply / exhaust conduit 30, the upstream side of the throttle valve 33 is generally at atmospheric pressure. The pressure difference with the gas pressure on the downstream side of the throttle valve 33 becomes a predetermined value or more, the supply / exhaust port 37a and the exhaust port 37c of the control valve 37 are communicated, and exhaust is also performed by the second supply / exhaust conduit 36. Will come to be.

  In addition, regardless of whether the leveling valve 31 is in the supply position or the exhaust position, the air pressure control valve 37 does not operate and the supply and exhaust air is exhausted if the magnitude of the differential pressure across the throttle valve 33 is less than a predetermined value. Also do not. Of course, when the lever 31a is substantially at the reference position and the leveling valve 31 does not supply or exhaust air, the air pressure control valve 37 does not operate because the differential pressure across the throttle valve 33 becomes zero.

  The control valve 37 preferably has a large capacity with a maximum flow rate higher than that of the leveling valve 31 according to the capacity of the air chamber S of the air spring 2. The air pressure source of the first supply / exhaust pipe line 30 and the second supply / exhaust pipe line 36 may be made common, but the air pressure source of the second supply / exhaust pipe line 36 is the maximum air pressure determined by the requirements of the mounted device D, That is, it is preferable that the air pressure corresponding to the maximum shared load is supplied when the shared load of any of the air springs 2 is maximized by the operation of the mounted device D.

  Next, regarding the operation of the vibration isolator A when the load sharing of each air spring 2 changes greatly, as in the case where the device D on the mounting board 1 is activated and the center of gravity moves in the horizontal direction. ,explain.

  For example, as schematically shown in FIG. 3, the moving body d <b> 1 on the mounted device D moves in the horizontal direction, the shared load of one of the air springs 2 increases, and the support height is lower than the reference height. Then, the leveling valve 31 is switched to the air supply position, and the pressurized air is directly supplied to the air chamber S of the air spring 2 by the first supply / exhaust pipe 30. At this time, if the change in the support height of the air spring 2 is larger than a certain level, the supply pressure is increased accordingly, and the air pressure upstream of the throttle valve 33 in the first supply / exhaust pipe 30 is reduced downstream. Therefore, the control valve 37 is operated, and the pressurized air is supplied to the air spring 2 also from the second supply / exhaust conduit 36.

  Then, by supplying pressurized air at a large flow rate by both the first and second supply / exhaust pipes 30 and 36, the internal pressure of the air spring 2 rises quickly, and the support height also increases slightly later. As it approaches the reference height, the opening of the leveling valve 31 decreases, the air pressure supplied to the upstream side of the throttle valve 33 gradually decreases, and the internal pressure of the air spring 2 increases. The air pressure on the downstream side of the throttle increases.

  If the upper / lower differential pressure of the throttle valve 33 becomes less than the predetermined value, the operation of the control valve 37 is stopped, the supply of pressurized air through the second supply / exhaust pipe 36 is stopped, and then the leveling valve 31 is stopped. Until the lever 31a is lifted and the support height of the air spring 2 is substantially equal to the reference height, only the small flow rate of pressurized air throttled by the throttle valve 33 is supplied from the first supply / exhaust pipe 30 alone. It is supplied to the spring 2.

  As described above, the pressurized air according to the change in the support height of the air spring 2 and the increase in its internal pressure, that is, at an appropriate timing corresponding to the supply state of the pressurized air to the air chamber S of the air spring 2. Is switched from a large flow rate supply state by the two supply / discharge conduits 30, 36 to a small flow rate supply state by only the first supply / discharge conduit 30, so that pressurized air is supplied to the air chamber S Without causing a delay, the excessive supply can be eliminated and the overshoot can be sufficiently suppressed.

  FIG. 4 shows the change in the support height when the shared load of the air spring 2 is increased as described above so that the first and second supply / exhaust conduits 30 and 36 are switched as in this embodiment. It is a graph of the test result shown in comparison with what made it and what supplies pressurized air to the air spring 2 only by the 1st supply / exhaust pipe line 30. As shown in FIG. (A), in this embodiment, the maximum displacement of the support height due to the change in the shared load is about 2 mm, which is compared with the comparative example (about 5 mm) shown in FIG. (B). It can be seen that it becomes significantly smaller. Moreover, in this embodiment, there is no overshoot, the displacement amount is 0.5 mm or less in less than 3 seconds, and the convergence time is very short.

  On the other hand, when the shared load of one of the air springs 2 decreases and the support height becomes higher than the reference height, the leveling valve 31 switches to the exhaust position and exhausts from the air spring 2, thereby the first supply Since the upstream side of the throttle valve 33 in the exhaust pipe 30 is close to the atmospheric pressure, the differential pressure with the downstream side becomes a predetermined value or more, the control valve 37 is activated, and the second supply / exhaust pipe 36 also exhausts air. Will come to be.

  If exhaust is performed at a large flow rate by both the first and second supply / exhaust pipes 30 and 36, the internal pressure of the air spring 2 is suddenly reduced, and the upper and lower differential pressure of the throttle valve 33 becomes less than a predetermined value. After the exhaust through the second supply / exhaust pipe 36 is finished, the exhaust is performed only by the first supply / exhaust pipe 30, that is, the throttle valve 33 is reduced to a small flow rate. As described above, as a result of switching the exhaust flow rate at an appropriate timing as in the air supply described above, overshoot can be sufficiently suppressed without causing a delay in exhaust from the air spring 2.

  Here, the appropriate timing for switching the air supply / discharge flow rate to the air spring 2 as described above is, for example, the volume of the air chamber S, the characteristics of the damping mechanism 25, the first and second supply / exhaust conduits 30, 36. Change depending on the cross-sectional area and length of each of the passages, the pressure of the air pressure source, and the like, and also change depending on the weight of the mounted device D, the height of the center of gravity, and the change in the shared load of the air spring 2 due to its operation. It will be.

  With respect to this point, in this embodiment, a throttle valve 33 whose throttle amount can be changed is disposed in the first supply / exhaust conduit 30, and the throttle amount is adjusted by the adjusting screw 33 a, so By changing the pressure, the operation timing of the control valve 37 can be changed very easily.

  Therefore, when the device D is actually mounted and operated, the change in the height position thereof is measured, and if the throttle amount of the throttle valve 33 is adjusted based on, for example, the displacement peak or the convergence time, the above-mentioned As described above, the appropriate timing can be set only by adjusting the throttle amount of the throttle valve 33, although the appropriate timing changes due to many factors.

  FIG. 5 shows the change in the support height when the shared load of the air spring 2 is reduced as compared with the comparative example in the embodiment as in FIG. Fig. (A) is a comparative example, and Figs. (B) and (c) are those of this embodiment, but Fig. (B) shows a relatively small throttle amount of the throttle valve 33 (passage cross-sectional area is small). (C) is a state where the amount of restriction is relatively large (the cross-sectional area of the passage is small).

  Compared to the comparative example shown in FIG. (A), the maximum displacement amount of the support height is lower in each of the embodiments shown in FIGS. (B) and (c) (about 9 mm → 2 to 5 mm). The time until the amount becomes 0.5 mm or less is also greatly shortened (about 10 seconds → about 4 seconds). On the other hand, when comparing the embodiments of FIGS. (B) and (c), as shown in FIG. (B), the smaller the amount of restriction, the larger the maximum displacement amount. When the amount is small, it is difficult for the pressure difference between the upper and lower sides of the throttle valve 33 to be generated. Therefore, the control valve 37 does not readily operate, the start of exhaust through the second supply / exhaust pipe 36 is delayed, and the control valve 37 that has once been operated. This is considered to be due to an increase in the exhaust delay from the air spring 2 as a result of immediately stopping and exhausting by the second supply / exhaust pipe 36 not being performed (exhaust is switched to a small flow rate).

  In addition, compared with the embodiments of FIGS. (B) and (c), the time until the displacement of the support height becomes 0.5 mm or less is about 4 seconds in both cases. In the time until the amount becomes 0.25 mm or less, the smaller diaphragm amount shown in FIG. 5B is about 5 seconds, which is shorter than about 8 seconds in FIG. This is because when the throttle amount is large and the pressure difference between the top and bottom is likely to occur (Fig. (C)), the timing of switching the exhaust flow rate to a small flow rate is delayed, resulting in excessive supply of air, which is large as shown in the figure. This is probably due to overshoot.

  When the throttle amount of the throttle valve 33 is adjusted in this manner, the cross-sectional area of the flow path is in the range of 5 to 55% of the cross-sectional area of the pipes 30c and 30d of the first supply / exhaust pipe 30. It is preferable that If the pressure is less than 5%, the throttle is too strong, and the switching timing of the air supply flow rate is delayed, resulting in an excessive supply. On the other hand, if it exceeds 55%, the throttle is too loose and it is difficult for a differential pressure to occur. For this reason, the control valve does not readily operate, and even if it is once activated, it immediately stops and immediately switches to a small flow rate.

  Therefore, according to the vibration isolator A according to this embodiment, the throttle valve 33 is provided in the first supply / exhaust pipe 30 that supplies and discharges air directly to the gas chamber S of the air spring 2 by the operation of the leveling valve 31. Thus, while the air supply / discharge amount is reduced, a control valve 37 is provided in the second supply / exhaust pipe 36, and this is operated according to the differential pressure of the throttle valve 33 as required. Air can be supplied to and discharged from the air spring 2 at a large flow rate, and can be switched to a small flow rate at an appropriate timing corresponding to the supply / discharge state. The return time to height can be shortened.

  Further, as described above, the throttle valve 33 that generates the differential pressure in the first supply / exhaust conduit 30 can adjust the throttle amount by the adjusting screw 33a, thereby changing the vertical differential pressure of the throttle valve 33. Since the flow rate switching timing by the control valve 37 can be changed very easily, even if the optimum timing changes due to various factors of the system, it is only necessary to adjust the throttle amount of the throttle valve 33 accordingly. Can be easily set to the appropriate timing.

  Further, in this embodiment, the downstream end of the second supply / exhaust pipe line 36 is connected to the first supply / exhaust pipe line 30 by the second branching portion 34 on the downstream side of the throttle valve 33, and the downstream pipe is further connected thereto. 30e and the supply / exhaust port 23 communicate with the air chamber S of the air spring 2, so that it is necessary to newly provide a through passage or the like in the air spring 2 only for the second supply / exhaust pipe 36. In addition, the apparatus cost can be reduced by simplifying the structure.

  In addition, when the second supply / discharge pipe 36 is connected downstream of the throttle valve 33, when pressurized air is supplied at a large flow rate, the gas pressure on the downstream side of the throttle increases. The control valve 37 may stop due to a decrease in the differential pressure from the upstream side, and the operation of the control valve 37 may become unstable. In this embodiment, the control valve 37 is replaced with a pressure reducing valve. Therefore, the operation pressure of the control valve 37 can be ensured.

  In addition, this invention is not limited to the said embodiment, Various other embodiment is included. That is, in the embodiment, a pressure reducing valve is used as the air pressure control valve 37, but this may be another air pressure control valve such as a direction control valve.

  For example, if the throttle valve 33 is provided integrally with the air pressure control valve 37 as shown in FIGS. In this case, an integrated composite valve 38 in which the throttle portion or the like indicated by the broken line in FIG. 6 is built in the pneumatic control valve 37 may be used, or the portion indicated by the broken line is provided separately as a manifold having the throttle portion built in. This may be integrated with the pneumatic control valve 37.

  Moreover, although the air spring 2 is used as a gas spring, you may use the other gas spring which filled nitrogen gas, for example. In addition, as the damping mechanism 25, various configurations can be adopted, and the damping mechanism 25 can be omitted.

  Furthermore, in the above-described embodiment, the throttle portion of the first supply / exhaust conduit 30 is configured by the throttle valve 33. However, the present invention is not limited thereto, and may be configured by, for example, a fixed throttle that cannot change the throttle amount. Alternatively, the throttle portion can be configured by making the pipes 30c and 30d of the first supply / exhaust pipe line 30 into a plurality of pipes having different diameters.

  When doing so, at first, the throttle part is configured by a variable throttle such as the throttle valve 33, and the actual mounted device D is actuated to measure the change of its height position. Based on the measurement result, After adjusting the throttle amount of the throttle valve 33 as described above, the fixed throttle with the throttle amount thus adjusted may be replaced with a combination of the pipes. By doing so, the cost of the apparatus can be reduced because the throttle valve 33 is not required.

It is a figure which shows schematic structure of the vibration isolator which concerns on embodiment of this invention. FIG. 2 is a view corresponding to FIG. 1, in which elements of the pneumatic circuit are represented by symbols. It is the top view and front view which show the state which mounted apparatuses etc. It is a graph which shows the change of the support height when the shared load of an air spring increases, (a) shows an embodiment and (b) shows a comparative example. FIG. 5 is a diagram corresponding to FIG. 4 when the shared load is reduced, where (a) shows a comparative example, and (b) and (c) show an embodiment. FIG. 3 is a view corresponding to FIG. 1 according to another embodiment in which a throttle portion is integrated with a pneumatic control valve. FIG. 3 is a view corresponding to FIG.

Explanation of symbols

A Vibration isolation device (Gas spring type vibration isolation device)
S Air chamber (gas chamber)
DESCRIPTION OF SYMBOLS 1 Mounting board 2 Air spring 3 Pneumatic circuit 30 1st supply / discharge passage (1st supply / discharge passage)
31 Leveling valve 33 Throttle valve (variable throttle)
35 Pilot pipeline (pilot passage)
36 Second supply / discharge pipe (second supply / discharge passage)
37 Control valve (pneumatic control valve)

Claims (5)

The supported body is elastically supported by a gas spring, and a mechanical leveling valve is provided in the first supply / exhaust passage that opens to face the gas chamber of the gas spring to change the height of the supported body. A gas spring type vibration isolator configured to supply and discharge gas directly to the gas chamber according to
The first supply / exhaust passage is provided with a throttle portion that restricts the flow of gas between the leveling valve and the gas chamber,
A second supply / discharge passage capable of supplying / discharging gas to / from the gas chamber without passing through the throttle portion is provided;
The second supply / exhaust passage receives pilot pressure from the leveling valve side upstream of the throttle and the downstream side opposite thereto, and the upstream pilot pressure is higher than a predetermined level than the downstream side. A gas spring type vibration isolation device is characterized in that a control valve is provided to supply gas to the gas chamber while exhausting from the gas chamber when the downstream pilot pressure is higher than the upstream side by a predetermined level or higher. apparatus.   2. The gas spring type vibration damping device according to claim 1, wherein the throttle portion of the first supply / discharge passage includes a variable throttle whose amount of restriction can be changed.   3. The gas according to claim 1, wherein the throttle portion of the first supply / exhaust passage has a cross-sectional area through which the gas flows is 5 to 55% of a passage cross-sectional area of another portion. Spring type vibration isolator. The second supply / discharge passage communicates with the first supply / discharge passage on the downstream side of the throttle portion;
The control valve of the second supply / exhaust passage is composed of a pressure reducing valve in which the downstream gas pressure communicating with the first supply / exhaust passage is adjusted according to the pilot pressure from the upstream side of the throttle portion. The gas spring type vibration isolator according to any one of claims 1 to 3. An adjustment method for adjusting the gas spring vibration isolator according to claim 1,
First, using a variable throttle that can change the throttle amount as the throttle part of the first supply / discharge passage,
Operate the device that is the supported body, measure the change in its height position,
After adjusting the aperture amount of the variable aperture based on the measurement result,
A method for adjusting a gas spring type vibration damping device, characterized in that the variable throttle is replaced with a fixed throttle whose amount of change cannot be changed.

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