JPS6321071B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a vibration isolator for so-called vertical pipes arranged in the vertical direction, and more specifically, to a vibration isolator for vibrations caused by fluid flow in pipes. The present invention also relates to a vertical pipe vibration isolator used to disperse vibration stress generated in a piping system due to sudden vibrations such as an earthquake.

[Conventional technology] Conventional anti-vibration piping support device (Suaverace)
There are spring-type vibration isolators and hydraulic-type vibration isolators, but spring-type vibration isolators have a relatively simple structure and can easily raise the natural frequency of the entire piping system to avoid resonance vibrations caused by external disturbances. On the other hand, it has the disadvantage that it restricts the expansion and contraction due to thermal expansion of the piping, and that large-capacity products are subject to restrictions due to the manufacturing aspects of the spring. In addition, the hydraulic vibration isolator can effectively reduce resonance vibrations, can freely follow the expansion and contraction of piping without being constrained, and large-capacity types can be manufactured relatively freely. However, the response to minute vibration amplitudes or high frequency vibrations is poor and the effectiveness cannot be expected, and the seal material is subject to constant internal stress and is prone to breakage. There are drawbacks such as. Furthermore, since these vibration isolators support the weight of the piping at the same time, it takes time and effort to adjust the load, making installation work inconvenient.

[Problems to be Solved by the Invention] In view of the above circumstances, the present invention focuses on the vibration absorption effect of viscous shear resistance caused by the relative movement between two surfaces of a viscous body interposed in the gap between the two surfaces, and solves the above problems. The object (technical means) is to provide a new vertical vibration isolation device that eliminates the drawbacks of the prior art.

[Means for Solving the Problems] For this purpose, the vibration isolating device of the present invention adopts the following configuration (technical means). That is, it consists of a flat movable plate, a movable box that accommodates the movable plate, and a fixed box with a bottom that accommodates the movable box, and the movable plate is attached in conjunction with the vertical pipe of the piping system. , is housed in the movable box so as to be movable in the direction of the plate surface via a spacer that maintains a minute gap distance sufficient to exhibit viscous shear resistance, and the movable box maintains a minute gap distance sufficient to exhibit viscous shear resistance. The movable plate is housed in the fixed box so as to be movable in a direction perpendicular to the plate surface of the movable plate via a spacer to be held, and a high viscosity viscous fluid is filled in the gap formed by the spacer. do.

In the above configuration, the minute gap sufficient to exert viscous shear resistance depends on the viscosity of the viscous fluid, but is maintained at least 0.5 mm. Further, the viscosity of the viscous fluid is supposed to maintain a high viscosity of no less than 1000 poise even when the viscosity decreases at high temperatures.

[Function] When a force is applied to the vertical pipe to displace it, the device can be moved in three axial directions, regardless of whether the vertical pipe is displaced in the direction of the pipe axis or in the direction perpendicular to the pipe axis. This displacement appears as relative movement between the two surfaces in the gap with the spacer interposed.
However, since the gap is filled with viscous fluid, viscous shear resistance acts here.

This viscous shear resistance force F is generally proportional to the viscosity coefficient U of the viscous fluid, the area S of the two surfaces that move relative to each other via the viscous fluid, and their relative velocity V, and inversely proportional to the minute gap h between the two surfaces. It is something.
This can be expressed as follows: F=U×S×(V/h) ^m (m is an index determined by the type of viscous fluid used).

Although the size of the minute gap is also related to the viscosity of the viscous fluid used, as can be seen from the above equation, a large resistance force can be obtained by making the distance as small as possible. However, in order to maintain a uniform minute gap over the entire surface between the resistor plates, the gap must be at least 0.5 mm or more, taking into account the difficulty in manufacturing.

The viscous fluid is appropriately selected depending on the environmental conditions in which the device is installed.

That is, under environmental conditions with large changes in temperature, the viscosity of the viscous fluid changes significantly, which greatly affects the viscous shear resistance. Usually, a viscous fluid having a viscosity of several hundred poise to tens of thousands of poise is used, but taking into consideration the degree of viscosity change due to temperature, the lower limit of the viscosity of the viscous fluid that can be used is 1000 poise.

The viscous shear resistance force generated in the gap described above immediately restrains the rapid movement of the movable plate and, by extension, the vertical pipe linked thereto.

[Effects] Since the vertical pipe vibration isolator of the present invention has the above-mentioned configuration and functions, it has the following various superior effects compared to conventional devices.

This device has a simple structure as a vibration isolating mechanism for vertical pipes, can be manufactured economically, and despite its simple structure, exhibits an excellent vibration damping function.

The movement of this device is not restricted to only one direction, but can be moved in any direction, making piping design much more flexible.

The vibrational displacement transmitted to this device is smoothly absorbed by the favorable speed-resistance characteristics of the viscous fluid, and the displacement is quickly stopped. In particular, even minute vibrations are quickly absorbed, so even if the vibrations match the natural vibrations of the piping system (resonant vibrations), the response value can be reduced.

The resistance due to viscous shear resistance does not increase the pressure inside the viscous fluid, so there is no need for a sealing mechanism required in conventional oil dampers, and there is no reduction in performance due to damage to the seal.

Slow expansion and contraction changes due to thermal expansion of the piping system can be absorbed by the moving region, and the displacement of the vertical pipe can be freely followed.

When installing this device, the position can be adjusted in the horizontal and vertical directions, making the installation work easy.

[Example] The present invention will be described below based on an example shown in the drawings.

Figures 1 to 4 show a part of the vibration isolating device S of the present invention.
This example shows two examples (first example),
Its outline is shown in the exploded perspective view of FIG. Here, P is a pipe arranged vertically (hereinafter referred to as a vertical pipe)
and a rib R is fixedly stretched on the vertical pipe P,
Furthermore, a mounting plate R' is attached to the rib.
R'a is a bolt through hole drilled in the mounting plate R'. Note that V is a bolt inserted into the bolt through hole and tightened with a nut (not shown) or the like.

Reference numeral 1 denotes a flat movable plate, which is fixed to the mounting plate R' of the rib R via the mounting plate 11 of the movable plate. Reference numeral 11a indicates a bolt through hole or screw hole bored in the mounting plate 11. The movable plate 1 is sufficiently thick and rigid enough not to bend even if a force perpendicular to the plate surface 1a is applied.

Reference numeral 2 denotes a rectangular parallelepiped-shaped movable box, the top and bottom of which are open, and the movable plate 1 is accommodated through the interior space.

Reference numeral 3 is a fixed box with a bottom, which is open at the top and accommodates the movable box 2. The fixing box 3 itself has a bottom, or the bottom is formed by fixing a bottom plate 31 to the lower part of the bottomless rectangular fixing box. Reference numeral 31a denotes a bolt through hole drilled in the bottom plate 31, which is used for attachment to the frame G.

The characteristic configuration of the present invention embodied in this embodiment is the assembly and arrangement relationship between the movable plate 1, the movable box 2, and the fixed box 3, the details of which are shown in FIGS. 2 and 3. . That is, a plurality of spacers 41 are embedded in the movable plate 1 so as to protrude from the flat plate surface 1a. The spacer 41 is in sliding contact with the inner surface of the movable box 2, and is made of a material that does not wear easily (usually metal, preferably high-strength brass), and the amount of protrusion from the flat plate surface 1a of the movable plate 1 is about 0.5 to 1 mm. is set (Figure 2). Since the upper and lower parts of the movable box 2 are open in the vertical direction (X-axis direction in FIG. 1), the movable plate 1 can move without being restricted; Since there is a movement space A in the Y-axis direction (FIG. 1), it is possible to move freely. The movable plate 1 is moved in the horizontal direction (the first
The movable box 2 is attached via a spacer 41 (in the Z-axis direction in the figure).
Since the movable plate 1 is arranged on the inner surface of the
It is movable in the direction indicated by a (X-Y axis direction, hereinafter referred to as the "plate surface direction" of the movable plate).

Moreover, a plurality of spacers 42 are embedded in the front and rear outer surfaces 2a of the movable box 2 so as to protrude from the outer surfaces 2a. The spacer 42 is in sliding contact with the front and rear inner surfaces of the fixed box 3, and its material and protrusion amount are the same as those of the spacer 41. The fixed box 3 is provided with stopper members 5 on the upper and lower sides of the front and rear inner surfaces of the side that slides in contact with the movable box 2, which slidably sandwich the upper and lower portions of the movable box 2 (FIG. 3). Therefore, the movable box 2 is attached to the fixed box 3 via the spacer 42 in the front-rear direction, and is attached to the fixed box via the stopper member 5 in the vertical direction. Since the movable box 2 cannot be moved and has a movement space B in the lateral direction, the movable box 2 is movable only in the lateral direction (hereinafter referred to as the "direction perpendicular to the plate surface" of the movable plate).

As a result, the movable plate 1 and the movable box 2 are replaced by the fixed box 3.
(or other stationary system), the three axes (X,
It is movable in the directions (Y and Z axes).

By assembling and installing the movable plate 1 into the movable box 2 and the movable box 2 into the fixed box 3, a gap 6 corresponding to the amount of protrusion of the spacers 41 and 42 is created between the members that come into sliding contact with each other. become.

Reference numeral 7 is a viscous fluid injected into the fixed box 3, and fills the gap 6 described above. The viscous fluid 7
In addition to ordinary viscous materials, high-viscosity viscous materials such as high-molecular viscous materials such as polyisobutylene, polypropylene, polybutene, dimethylpolysiloxane, or asphalt are used in particular to improve the damping characteristics described below. .

The installation of the vibration isolator S according to this embodiment of the invention is carried out as follows. A rib R having a mounting plate R' is fixed at a predetermined position on the vertical pipe P by welding or the like.
In addition, a pedestal G is provided around the vertical pipe P, and the pedestal G is
The vibration isolator S is interposed between the support plate 31 and the rib R, and the fixing box 3 is attached to the frame G with bolts through the bolt holes 31a of the support plate 31, or fixed by direct welding. After that, the movable plate 1 inserted into the movable box 2 is pulled up a little, and the mounting plate 11 of the movable plate 1 is attached to the mounting plate of the rib R.
R', and after aligning the bolt through holes R'a and 11a, they are fixed with bolts and nuts, or both are fixed by welding.

This installation work is easy and has the following advantages. During the installation work, even if there is some horizontal deviation in the installation positions of the frame G and the rib R, the movement range B between the fixed box 3 and the movable box 2, and the movement range A between the movable box 2 and the fixed plate 1. Furthermore, vertical displacement is also absorbed by moving the movable plate 1 in and out of the movable box 2 up and down, and the position is adjusted. When the installation is completed, in order to prevent dust from getting into the viscous fluid 7 in the fixed box 3 of this device Dust-proof covers can also be attached to the edges.

The device S of the present invention may be installed independently on the vertical pipe P, or may be installed on the same frame G in combination with another support device (for example, a spring support Q), or It is also possible to use a combination of these as appropriate (see FIG. 4).

Therefore, when looking at the response of the vibration isolator S of the present invention embodied in the first embodiment to the displacement (vibration and movement) of the vertical pipe P, it is found that the vertical pipe P is Regardless of which direction it is displaced, the device S can be moved in three axial directions, and this displacement appears as a relative movement between the two surfaces in the gap 6 with the spacers 41 and 42 interposed therebetween. However, since the gap 6 is filled with the viscous fluid 7, viscous shear resistance acts here. In other words, the resistance force due to viscous shear is generally proportional to the viscosity coefficient of the viscous body, the area of the two surfaces that move relative to each other through the viscous body, and their relative speed, and inversely proportional to the gap distance between the two surfaces. According to these specifications of the device S, a resistance force acts in a direction to stop the movement of the movable box 2 and the movable plate 1, as well as the vertical pipe P that is interlocked therewith. Since the gap 6 has an extremely small distance and a large relative area between the plate surfaces, the resistance force acting between the two surfaces is extremely large and immediately stops the movement of the vertical pipe P.

When a high-viscosity polymeric viscous body is used as the viscous fluid 7, this tendency becomes even more remarkable. In other words, this viscous body exhibits non-Newtonian fluid properties, that is, pseudoplastic fluid properties (a phenomenon in which the higher the velocity of the fluid, the easier it is to change from high viscosity to low viscosity and flow, and the degree of increase in resistance force decreases.Resistance) (Force is approximately proportional to the speed to the 0.5 to 0.6 power.) The generation of the resistance force is constant regardless of the displacement amplitude and frequency as long as the speed is the same, and when a constant speed is given, the resistance force is Since it shows a rise like a rectangular wave, it is extremely sensitive to vibrations and has the advantage of excellent quick response. As a result, the kinetic energy of the vertical pipe P is quickly absorbed, and harmful stress caused by vibration is not generated in each component of the vibration isolator S.

FIGS. 5 and 6 show other embodiments (second embodiment) of the present invention.
Examples) are shown below. Components that perform the same functions as those in the first embodiment are given the same reference numerals.
The features of the configuration that are different from those of the first embodiment are that the movable box 2 has a bottom, the bottom 21 is flat, and a spacer 42 is provided on the lower surface 211 of the bottom 21.
is buried, and the movable box 2 is placed on the inner bottom surface of the fixed box 3. Further, the side surface 212 of the bottom portion 21 in the front-rear direction (Y direction) is formed as a sliding surface, and is restrained by the inner surface formed on the sliding surface of the fixed box 3, so that only sliding is possible. Further, a side surface 213 in the lateral direction (Z direction) of the bottom portion 21 exists in a moving region B and is opposed to the inner surface of the fixed box 3. Therefore, the movable box 2 and the fixed box 3 are arranged so that the lower surface 211 of the movable box and the inner bottom surface of the fixed box 3 are separated from each other by a gap 6 corresponding to the amount of protrusion of the spacer 42, and only in the lateral direction (Z direction). It will be installed to allow relative movement.

Further, since the viscous fluid 7 is separately filled into the movable box 2 and the fixed box 3, the amount of viscous fluid can be smaller than that in the first embodiment.

The present invention is not limited to the configurations of the above two embodiments, and various design changes can be made within the scope of the basic technical idea of the present invention. That is, ○A The arrangement of the movable plate 1, movable box 2, and fixed box 3 is as follows:
For example, it is not necessary to align the movable plate 1 with the radial direction of the vertical pipe P, and it can be set at any position as long as it is vertical.
Since it can move in the axial direction, this device S
The installation direction is free.

○B Also, the spacers 41 and 42 may be embedded in a manner other than the embodiments described above, for example, the spacers 41 and 42 may be embedded.
on the inner surface of the movable box 2 or the spacer 42
It is free to embed the spacers 41, 4 in the inner bottom surface of the fixing box 3.
2 can maintain a suitable gap between the viscous resistance surfaces of the movable plate 1, the movable box 2, and the fixed box 3.

[Brief explanation of the drawing]

The drawings show a vertical pipe vibration isolator of the present invention, and the first
The figure is an exploded perspective view of one embodiment, Figures 2 and 3.
The figure is an enlarged sectional view of the main part, FIG. 4 is an example of use, and FIGS. 5 and 6 are sectional views of the main part of other embodiments. S... Vibration isolator, 1... Movable plate, 1a... Movable plate surface, 2... Movable box, 3... Fixed box, 41, 42
... Spacer, 6 ... Gap, 7 ... Viscous fluid,
8...Vertical pipe.

Claims (1)

[Claims] 1. Consists of a flat movable plate 1, a movable box 2 that accommodates the movable plate 1, and a fixed box 3 with a bottom that accommodates the movable box 2, wherein the movable plate 1 is connected to piping. It is attached in conjunction with the vertical pipe P of the system, and is housed in the movable box 2 so as to be movable in the direction of the plate surface 1a via a spacer 41 that maintains a minute gap distance sufficient to exert viscous shear resistance. The movable box 2 is housed in the fixed box 3 so as to be movable in a direction perpendicular to the plate surface 1a of the movable plate 1 via a spacer 42 that maintains a minute gap distance sufficient to exert viscous shear resistance, and the spacer 41, A vibration isolator for a vertical pipe, characterized in that a gap 6 formed by 42 is filled with a highly viscous fluid 7. 2. The vertical pipe vibration isolator according to claim 1, wherein the spacers 41 and 42 are made of high-strength brass. 3. The vertical pipe vibration isolator according to claim 1 or 2, wherein the spacer 41 is fixed to the plate surface 1a of the movable plate 1. 4. The vibration isolator according to claim 1 or 2, wherein the spacer 42 is fixed to the outer surface 2a or the bottom surface 211 of the movable box 2.