Dynamic vibration absorber for pipeline

Abstract

To provide a dynamic vibration absorber for a pipeline which enables dynamic vibration absorbers for suppressing vibration to be attached to desired positions of a pipeline.SOLUTION: A dynamic vibration absorber for a pipeline 10 includes a first dynamic vibration absorber 20 and a second dynamic vibration absorber 40. The first dynamic vibration absorber 20 includes a first base part 28, a first beam part 29 and a second beam part 30 protruding from the first base part 28, and mass bodies 31, 32 attached to the beam parts 29, 30. The second dynamic vibration absorber 40 includes a second base part 42 which is disposed spaced apart from a pipeline 1, a first biasing spring 45 and a second biasing spring 46, and a mass body 47 sandwiched between the biasing springs 45, 46. The dynamic vibration absorber for the pipeline 10 includes attachment mechanisms 15 for attaching the dynamic vibration absorbers 20, 40 to the pipeline 1.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a dynamic vibration absorber for piping. [Background technology]

[0002] The possibility of vibration occurring in pipes is increasing due to the increased efficiency of drainage pumps and the increased flow rate of cooling pipes for pump bearings caused by higher pressures and temperatures. Patent Document 1 discloses vibration-reducing piping for suppressing pipe vibration. This vibration-reducing piping aims to suppress vibration by forming a spiral curved pipe section with 1.5 turns in the center of the pipe. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 9-53759 Summary of the Invention [Problem to be solved by the invention]

[0004] Piping is not limited to being straight, and the part of the pipe where the greatest vibration occurs is not limited to the center. Therefore, even if the vibration-reducing piping of Patent Document 1 is used, vibration may occur in parts other than the curved pipe section. Dynamic vibration absorbers are known for suppressing vibration, but no consideration is given to attaching dynamic vibration absorbers to piping. Note that piping vibration is not limited to piping attached around the drainage pump, but can also occur in the drainage pump itself and the piping of equipment or facilities other than the drainage pump.

[0005] An object of the present invention is to provide a dynamic vibration absorber for piping that can be attached to a desired position on a piping to suppress vibrations. [Means for solving the problem]

[0006] The present invention provides a first dynamic vibration absorber and a second dynamic vibration absorber that are attached to a pipe, the first dynamic vibration absorber having a first base, a first beam portion that protrudes from the first base to one side of a predetermined direction along a plane that includes a first direction that is a direction in which an attachment position of the pipe extends and a second direction that intersects with the first direction, a second beam portion that protrudes from the first base to the other side of the predetermined direction, a first mass that is attached to the first beam portion, and a second mass that is attached to the second beam portion, a second base disposed at a distance from the piping in a third direction intersecting the plane; a first biasing spring disposed on the second base on the side of the piping; a second biasing spring disposed on the side of the piping at a distance from the first biasing spring in the third direction; and a third mass held between the first biasing spring and the second biasing spring, and further comprising an attachment mechanism for attaching the first dynamic vibration absorber and the second dynamic vibration absorber to the piping.

[0007] The dynamic vibration absorber includes a mounting mechanism for mounting the first and second dynamic vibration absorbers to the pipe. Therefore, the first and second dynamic vibration absorbers can be mounted at desired positions on the pipe. The first dynamic vibration absorber includes a first beam portion and a second beam portion protruding from the first base portion on both sides along a plane including a first direction, which is the direction in which the pipe's mounting position extends, and a second direction intersecting the first direction, and a first mass body and a second mass body attached to the beam portion and the beam portion. Therefore, vibration of the pipe in a direction along the plane can be effectively suppressed. The second dynamic vibration absorber includes a first biasing spring and a second biasing spring arranged on the second base portion side and the pipe side, spaced apart in a third direction intersecting the plane, and a third mass body sandwiched between the first and second biasing springs. Therefore, vibration of the pipe in the third direction intersecting the plane can be effectively suppressed. [Effects of the Invention]

[0008] In the present invention, a dynamic vibration absorber for suppressing vibrations can be attached to a desired position on the piping. [Brief explanation of the drawings]

[0009] [Figure 1]1 is a partially cutaway front view of a dynamic vibration absorber for piping according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a side view of the dynamic vibration absorber for piping shown in FIG. 1. [Figure 3] FIG. 2 is a bottom view of the first dynamic vibration absorber of FIG. 1 . [Figure 4] FIG. 4 is an enlarged cross-sectional view of a portion IV of the first dynamic vibration absorber of FIG. [Figure 5] 10 is a graph showing the load characteristics of a biasing spring. [Figure 6] FIG. 2 is a partial cross-sectional view showing a state in which the position of the base of the second dynamic vibration absorber of FIG. 1 has been adjusted. [Figure 7] FIG. 6 is a partial cross-sectional view of a dynamic vibration absorber for piping according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0011] (First embodiment) 1 and 2, a dynamic vibration absorber 10 for piping (hereinafter referred to as "dynamic vibration absorber") according to a first embodiment of the present invention is attached to a pipe 1 that is attached to a drainage pump (not shown), and suppresses vibrations that occur in the pipe 1. However, the dynamic vibration absorber 10 of the present invention is not limited to being used for a pipe 1 used in a drainage pump, and may also be used for the drainage pump itself and for piping of equipment or facilities other than a drainage pump.

[0012] The X direction in the accompanying drawings is the direction in which the mounting position of the pipe 1 extends on a horizontal plane (lateral direction), and is the first direction and the predetermined direction in the present invention. The Y direction is the direction perpendicular to the direction in which the mounting position of the pipe 1 extends on a horizontal plane, and is the second direction in the present invention. The Z direction is the up-down direction perpendicular to the horizontal plane, and is the third direction in the present invention. The pipe 1 is not limited to a configuration that extends linearly in the X direction, but may also be configured to extend in a curved manner. Furthermore, the direction in which the mounting position of the pipe 1 extends is not limited to the X direction along a horizontal plane, and may also include an inclined configuration.

[0013] The dynamic vibration absorber 10 comprises two types of dynamic vibration absorbers 20, 40 and an attachment mechanism 15 to which the dynamic vibration absorbers 20, 40 are respectively attached. The first dynamic vibration absorber 20 and the second dynamic vibration absorber 40 are each attached to different pipes 1 via the attachment mechanism 15. In the following description, the side to which the first dynamic vibration absorber 20 is attached may be referred to as pipe 1A, and the side to which the second dynamic vibration absorber 40 is attached may be referred to as pipe 1B. However, the dynamic vibration absorbers 20, 40 may also be attached via the attachment mechanism 15 to different positions on the same pipe 1.

[0014] (Configuration of mounting mechanism) 1 and 2, the mounting mechanism 15 includes a U-bolt (fastening member) 16 and a mounting seat 18. The mounting mechanism 15 to which the first dynamic vibration absorber 20 is attached and the mounting mechanism 15 to which the second dynamic vibration absorber 40 is attached have different parts in the configuration of the mounting seat 18. In the following explanation, the side to which the first dynamic vibration absorber 20 is attached may be referred to as mounting seat 18A, and the side to which the second dynamic vibration absorber 40 is attached may be referred to as mounting seat 18B.

[0015] The U-bolt 16 is U-shaped and can surround a portion of the pipe 1, and includes a semicircular arc portion 16a and a pair of bolt shanks 16b connected to both ends of the arc portion 16a. The inner diameter of the arc portion 16a is larger than the outer diameter of the pipe 1 and is as small as possible while still being able to hold the pipe 1. The pair of bolt shanks 16b protrude from both ends of the arc portion 16a along lines tangent to both ends of the arc portion 16a. Nuts 17 are threadedly engaged with the tip portions of the pair of bolt shanks 16b, which penetrate the mounting seat 18.

[0016] In this embodiment, two U-bolts 16 are used. However, the number of U-bolts 16 may be one, or may be three or more, and can be changed as needed as long as the mounting seat 18 can be stably fastened. Furthermore, fastening members other than U-bolts 16 may be used as long as they are configured to surround a portion of the piping 1 and be fastened to the mounting seat 18.

[0017] Mounting seat 18 is block-shaped and is disposed on the opposite side of pipe 1 from arc portion 16a of U-bolt 16. Mounting seat 18 is formed with an arc-shaped recessed groove 18a that follows the outer peripheral surface of pipe 1 and extends along the mounting position of pipe 1. Mounting seat 18 also has a through-hole 18b that allows bolt shank 16b of U-bolt 16 to pass through. By passing bolt shank 16b through mounting seat 18 and tightening it with nut 17, mounting seat 18 is attached to pipe 1 in a pressure-welded state.

[0018] The mounting seat 18 is provided with bolt holes 18c extending upward from the bottom surface for attaching the first base 28 of the first dynamic vibration absorber 20 or the second base 42 of the second dynamic vibration absorber 40. The mounting seat 18A to which the first dynamic vibration absorber 20 is attached is provided with only one bolt hole 18c in the center. The mounting seat 18B to which the second dynamic vibration absorber 40 is attached is provided with multiple (four in this embodiment) bolt holes 18c spaced apart around the axis A that passes through the center of the mounting seat 18B.

[0019] 1 shows a state in which the axis A of mounting seat 18A and the axis A of mounting seat 18B are aligned, but in most cases they are not. In the following description, the axis A of mounting seat 18A may be referred to as the axis A of first dynamic vibration absorber 20, and the axis A of mounting seat 18B may be referred to as the axis A of second dynamic vibration absorber 40.

[0020] (Configuration of the first dynamic vibration absorber) 1 and 2, the first dynamic vibration absorber 20 is provided to reduce or suppress vibration of the pipe 1A mainly in a direction along the horizontal plane (XY plane) in which the mounting position of the pipe 1A extends. The first dynamic vibration absorber 20 includes a casing 21 attached to the mounting seat 18A of the mounting mechanism 15. The first dynamic vibration absorber 20 also includes a first base 28, a first beam 29, a second beam 30, a first mass 31, and a second mass 32 housed within the casing 21.

[0021] The casing 21 includes a casing body 22, a pair of covers 23, a latch seat 25, and a support seat 26. In addition, a latch mechanism (positioning mechanism) 34 is provided between the casing 21 and the mounting seat 18A to determine the orientation of the first dynamic vibration absorber 20 with respect to the piping 1A.

[0022] The casing body 22 is cylindrical and open at both ends. An axis B of the casing body 22 (casing 21) extends along the XY plane. A through-hole 22a is provided in the axial center of the casing body 22, penetrating in the radial direction. The openings at both ends of the casing body 22 are liquid-tightly and airtightly closed by covers 23. One of the pair of covers 23 (the right side in FIG. 1 ) is provided with an opening 23a that connects the inside and outside of the casing body 22. The opening 23a is releasably closed by a plug 24.

[0023] The casing 21 contains a fluid (not shown) that functions as a damping element for damping vibrations of the first beam 29 including the first mass 31 and the second beam 30 including the second mass 32. The fluid is air or a lubricating oil, which is a liquid. However, water may be used as the liquid instead of the lubricating oil.

[0024] The latch seat 25 is disposed above the casing body 22 and adjacent to the lower side of the mounting seat 18A. An arc-shaped positioning groove 25a is formed on the lower side of the latch seat 25 along the outer circumferential surface of the casing body 22. A through hole 25b corresponding to the through hole 22a of the casing body 22 is provided in the center of the latch seat 25.

[0025] The support seat 26 is disposed below the casing body 22 and cooperates with the latch seat 25 to hold the casing body 22. An arc-shaped positioning groove 26a is formed on the upper side of the support seat 26 along the outer circumferential surface of the casing body 22. A through hole 26b corresponding to the through hole 22a of the casing body 22 is provided in the center of the support seat 26.

[0026] After arranging the latch seat 25 and the support seat 26 above and below the casing body 22, the bolts 27 are passed through the through holes 22a, 25b, and 26b and tightened into the bolt holes 18c of the mounting seat 18A. This attaches the casing 21 to the mounting seat 18 of the mounting mechanism 15.

[0027] As described above, the first dynamic vibration absorber 20 is attached to the mounting mechanism 15 by one bolt 27. Therefore, the first dynamic vibration absorber 20 is rotatable about the axis of the bolt (rotation shaft) 27, which coincides with the axis A extending in the vertical direction, relative to the mounting mechanism 15 including the piping 1A. A latch mechanism 34, which will be described in detail later, is provided to determine the angular position of the casing 21 relative to the mounting mechanism 15 including the piping 1A.

[0028] First base portion 28 has a cylindrical shape that can be fitted into casing main body 22, and is disposed in the axial center of casing 21. First base portion 28 is provided with through-holes 28a that penetrate in the radial direction so as to correspond to through-holes 25b, 26b. Bolt holes 28b that are recessed in the axial direction are provided on both axial sides of first base portion 28 that coincide with axis B of casing 21.

[0029] The first beam portion 29 protrudes from the first base portion 28 to one side (the left side in FIG. 1) along the axis B of the casing 21. The second beam portion 30 protrudes from the first base portion 28 to the other side (the right side in FIG. 1) along the axis B of the casing 21. These beam portions 29, 30 are formed by stud bolts made of elastic spring steel, and are each screwed into a bolt hole 28b in the first base portion 28. In other words, the beam portions 29, 30 each have a cantilever structure in which only one end is fixed to the first base portion 28.

[0030] The diameter of each of the beam portions 29, 30 corresponds to the hole diameter of the corresponding bolt hole 28b in the first base portion 28. In this embodiment, the diameter of the first beam portion 29 including the bolt hole 28b located on the left side in FIG. 1 is smaller than the diameter of the second beam portion 30 including the bolt hole 28b located on the right side in FIG. 1. However, the diameter of the first beam portion 29 including the bolt hole 28b and the diameter of the second beam portion 30 including the bolt hole 28b may be the same. Alternatively, the diameters of the pair of bolt holes 28b may be the same, and the diameter of the first beam portion 29 protruding from the first base portion 28 may be different from the diameter of the second beam portion 30. Alternatively, the cross-sectional shapes of the first beam portion 29 and the second beam portion 30 may be rectangular with different dimensions in the up-down direction and the lateral direction.

[0031] The first mass 31 and the second mass 32 are cylindrical with an outer diameter smaller than the inner diameter of the casing main body 22. The first masses 31 and 32 are provided with bolt holes 31a and 32a, respectively, that penetrate along an axis that coincides with the axis B of the casing and correspond to the threads of the beam portions 29 and 30. The first mass 31 is threadedly engaged with the first beam portion 29 and attached to the first beam portion 29 by tightening a nut 31b onto the first beam portion 29. The second mass 32 is threadedly engaged with the second beam portion 30 and attached to the second beam portion 30 by tightening a nut 32b onto the second beam portion 30. A variety of first masses 31 and second masses 32 with different weights are available and are interchangeable.

[0032] 3 and 4, the latch mechanism 34 is provided to set the attitude of the first dynamic vibration absorber 20 relative to the mounting mechanism 15 including the pipe 1A, i.e., the direction in which the first beam portion 29 and the second beam portion 30 extend, at a predetermined angular position. The latch mechanism 34 is provided between the casing 21 and the mounting seat 18A, and is composed of an accommodation hole 37 that accommodates the coil spring 35 and the rolling elements 36, and a plurality of positioning recesses 38.

[0033] The accommodating hole 37 is a space with a circular cross section and the smallest possible diameter that can accommodate the spherical rolling element 36, and is recessed upward from the underside of the mounting seat 18A of the mounting mechanism 15. The positioning recess 38 is a spherical recess into which part of the rolling element 36 can be fitted, and is provided on the upper surface of the latch seat 25. The distance from the axis A to the center of the accommodating hole 37 and the distance from the axis A to the center of the positioning recess 38 are the same. A plurality of positioning recesses 38 (for example, 24 locations) are provided at equal intervals around the axis A. However, the accommodating hole 37 may be provided in the latch seat 25, and the positioning recess 38 may be provided in the mounting seat 18A.

[0034] 1 to 3, the first dynamic vibration absorber 20 (secondary vibration system) attached to the mounting mechanism 15 can be attached at a desired position relative to the piping 1A (primary vibration system). Of the first dynamic vibration absorber 20, the first beam portion 29 including the first mass body 31 and the second beam portion 30 including the second mass body 32 oscillate along the XY plane in response to vibrations of the piping 1A. The first beam portion 29 including the first mass body 31 and the second beam portion 30 including the second mass body 32 each have their own natural frequencies, and therefore can suppress vibrations of the piping 1A in the X and Y directions.

[0035] Furthermore, multiple types of first mass body 31 and second mass body 32 with different weights are provided. The mounting position of first mass body 31 relative to first beam portion 29 and the mounting position of second mass body 32 relative to second beam portion 30, i.e., the distance from axis A to mass bodies 31 and 32, can be changed by adjusting the degree of engagement between mass bodies 31 and 32 and nuts 31b and 32b. Therefore, by changing mass bodies 31 and 32 and adjusting their mounting positions, the natural frequencies of first beam portion 29 including first mass body 31 and second beam portion 30 including second mass body 32 can be adjusted. This effectively suppresses vibration of piping 1A. The weight M of mass bodies 31 and 32 is approximately 5% of the weight Mp of piping 1A to which they are attached.

[0036] Furthermore, the first dynamic vibration absorber 20 of this embodiment is rotatably attached to the mounting seat 18A of the mounting mechanism 15, and can be positioned at a predetermined angular position by the latch mechanism 34 (see FIG. 4). Therefore, by adjusting the angle of the axis B of the casing 21 relative to the axis of the piping 1A depending on the maximum vibration direction of the piping 1A, vibration of the piping 1A can be more effectively suppressed.

[0037] (Configuration of the second dynamic vibration absorber) 1 and 2, the second dynamic vibration absorber 40 is provided to reduce or suppress vibration of the pipe 1B in the vertical direction that intersects with the horizontal plane in which the mounting position of the pipe 1B extends. The second dynamic vibration absorber 40 includes a support member 41 that is attached to the mounting seat 18B of the mounting mechanism 15. The second dynamic vibration absorber 40 also includes a second base 42, a cylindrical container 44, a first biasing spring 45, a second biasing spring 46, and a mass body (third mass body) 47.

[0038] The support members 41 are provided to support the second base 42 at a distance from the mounting seat 18B of the mounting mechanism 15 including the piping 1B. The support members 41 in this embodiment are formed of stud bolts, and are attached to the mounting seat 18B so as to be threaded into the bolt holes 18c and extend downward.

[0039] The second base 42 is plate-shaped and supported by the support members 41, and is disposed below the mounting seat 18B of the mounting mechanism 15, which includes the pipe 1B, at a distance. The second base 42 is provided with a plurality of through holes 42a, through which the plurality of support members 41 pass, respectively. The second base 42 is supported by the support members 41 by passing the support members 41 through the through holes 42a and tightening nuts 43 to the support members 41. The distance between the second base 42 and the mounting seat 18B, which includes the pipe 1B, can be adjusted by changing the tightening amount of the nuts 43 to the support members 41. The second base 42 is provided with an opening 42b that penetrates in the vertical direction at the center of the second base 42, through which the axis A passes.

[0040] The cylindrical container 44 is a cylindrical cylinder that accommodates the mass body 47 so that it can move linearly. The lower end of the cylindrical container 44 is attached airtight and liquidtight to the second base 42. The upper end of the cylindrical container 44 is open and positioned with a gap relative to the mounting seat 18B of the mounting mechanism 15 on the piping 1B side.

[0041] The first biasing spring 45 is a compression spring that biases the mass body 47 upward, and is disposed on the piping 1B side of the second base 42. The second biasing spring 46 is a compression spring that biases the mass body 47 downward, and is disposed above the first biasing spring 45 on the piping 1B side with a gap therebetween. The lower end of the first biasing spring 45 is supported on the upper surface of the second base 42, and the upper end of the first biasing spring 45 is supported on the lower surface of the mass body 47. The upper end of the second biasing spring 46 is supported on the lower surface of the mounting seat 18B of the mounting mechanism 15, and the lower end of the second biasing spring 46 is supported on the upper surface of the mass body 47. It is preferable that the mounting seat 18B be provided with a structure that positions and holds the upper end of the second biasing spring 46.

[0042] In this embodiment, both the first biasing spring 45 and the second biasing spring 46 are nonlinear coil springs with nonlinear load characteristics. More specifically, the biasing springs 45, 46 are conical and cylindrical, with the coil diameter gradually decreasing from one end to the other. The diameter of the spring wire gradually decreases from the largest coil diameter at one end to the smallest coil diameter at the other end. The first biasing spring 45 thus configured has its end with the largest coil diameter abutting against the second base 42, and its end with the smallest coil diameter abutting against the mass body 47. The second biasing spring 46 has its end with the largest coil diameter abutting against the mounting seat 18B of the mounting mechanism 15, and its end with the smallest coil diameter abutting against the mass body 47.

[0043] FIG. 5 shows the load characteristics of the biasing springs 45, 46. The horizontal axis of FIG. 5 represents the amount of deformation, and the vertical axis of FIG. 5 represents the magnitude of the load. Referring to FIG. 5, the biasing springs 45, 46 have a first linear characteristic in the early stage of compression from no load (zero) to deflection δ0, a non-linear characteristic in the middle stage of compression from deflection δ0 to δ1, and a second linear characteristic in the later stage of compression from deflection δ1 to δ2. The slope of the first linear characteristic in the early stage of compression is smaller than the slope of the second linear characteristic in the later stage of compression.

[0044] The mass body 47 is cylindrical with an outer diameter smaller than the inner diameter of the cylindrical container 44, and is sandwiched between the first biasing spring 45 and the second biasing spring 46. A seal member 48 is attached to the outer periphery of the mass body 47 to seal the space between the mass body 47 and the cylindrical container 44. The mass body 47 configured in this manner functions as a piston when placed inside the cylindrical container 44. The air in the space between the mass body 47 and the second base 42 inside the cylindrical container 44 functions as a damping element. Multiple types of mass bodies 47 with different weights are prepared and are interchangeable. It is preferable that the mass body 47 be provided with a structure for positioning and holding the biasing springs 45, 46.

[0045] 1 and 2, the second dynamic vibration absorber 40 (secondary vibration system) attached to the mounting mechanism 15 can be attached to a desired position relative to the piping 1B (main vibration system). Of the second dynamic vibration absorber 40, a mass body 47 sandwiched between a pair of biasing springs 45, 46 moves forward and backward in the vertical direction (Z direction) in response to vibrations of the piping 1B. The biasing springs 45, 46 including the mass body 47 have a natural frequency, and therefore can suppress vertical vibrations of the piping 1B.

[0046] Moreover, multiple types of mass bodies 47 with different weights are prepared. As shown in FIG. 6, the support position of the second base 42 can be adjusted by changing the tightening amount of the nut 43, thereby adjusting the distance between the mounting seat 18B of the mounting mechanism 15 and the second base 42, thereby adjusting the spring constant k of the biasing springs 45, 46, and thus the natural frequency of the second dynamic vibration absorber 40. This effectively suppresses vibrations in the pipe 1B. The weight M of the mass body 47 is approximately 5% of the weight Mp of the pipe 1B to which it is attached. It is also preferable to provide a scale on the support member 41 so that the natural frequency of the second dynamic vibration absorber 40 can be confirmed, for example, by comparing it with the upper end of the cylindrical container 44.

[0047] The dynamic vibration absorber 10 of the first embodiment configured as above has the following features.

[0048] The mounting mechanism 15 is provided for mounting the first dynamic vibration absorber 20 and the second dynamic vibration absorber 40 to the pipe 1. Therefore, the first dynamic vibration absorber 20 and the second dynamic vibration absorber 40 can be mounted at a desired mounting position on the pipe 1. The first dynamic vibration absorber 20 includes a first beam portion 29 and a second beam portion 30 that protrude from a first base portion 28 on both sides along the XY plane, and a first mass body 31 and a second mass body 32 attached thereto. Therefore, vibration of the pipe 1 in the direction along the XY plane can be effectively suppressed. The second dynamic vibration absorber 40 includes a first biasing spring 45 and a second biasing spring 46 that are spaced apart in the vertical direction intersecting the plane, one on the second base portion 42 side and the other on the pipe 1 side, and a mass body 47 sandwiched between them. Therefore, vibration of the pipe 1 in the vertical direction intersecting the XY plane can be effectively suppressed.

[0049] The mounting mechanism 15 has a U-bolt 16 and a mounting seat 18 that is fastened to the U-bolt 16 and attached by being pressed against the piping 1. Therefore, the first dynamic vibration absorber 20 and the second dynamic vibration absorber 40 can be easily and reliably attached to the piping 1 without damaging the piping 1.

[0050] The first dynamic vibration absorber 20 and the second dynamic vibration absorber 40 are each attached to a different attachment mechanism 15. Therefore, depending on the actual vibration conditions of each individual pipe 1, the first dynamic vibration absorber 20 or the second dynamic vibration absorber 40 can be attached to suppress vibration of the pipe 1.

[0051] The casing 21 of the first dynamic vibration absorber 20 is rotatably attached to the mounting mechanism 15 around bolts 27 extending in the vertical direction. The casing 21 and the mounting mechanism 15 are also provided with a latch mechanism 34 for determining the extension direction of the first beam portion 29 and the second beam portion 30. This allows the extension direction of the first beam portion 29 and the second beam portion 30 to be adjusted according to the maximum vibration direction of the piping 1, thereby effectively suppressing vibration of the piping 1.

[0052] The second dynamic vibration absorber 40 has a support member 41 that supports the second base portion 42, and the support member 41 is capable of adjusting the distance of the second base portion 42 from the mounting mechanism 15. By adjusting the distance of the second base portion 42 from the mounting mechanism 15, the spring constant k of the first biasing spring 45 and the second biasing spring 46 can be increased or decreased. As a result, the natural frequency of the second dynamic vibration absorber 40 can be changed, thereby effectively suppressing vibration of the piping 1.

[0053] Other embodiments and various modifications of the present invention will be described below, but in these descriptions, points that are not particularly mentioned are the same as those in the first embodiment. In the drawings referred to below, the same elements as those in the first embodiment are given the same reference numerals.

[0054] (Second embodiment) 7, the dynamic vibration absorber 10 of the second embodiment differs from the dynamic vibration absorber 10 of the first embodiment in that the first dynamic vibration absorber 20 and the second dynamic vibration absorber 40 are provided as an integrated unit and there is only one mounting mechanism 15. The second embodiment also differs from the first embodiment in that the first dynamic vibration absorber 20 and the second dynamic vibration absorber 40 are connected by a pipe 50.

[0055] The mounting mechanism 15, similar to the first embodiment shown in Fig. 1, includes a U-bolt 16 and a mounting seat 18. The mounting seat 18, similar to the mounting seat 18A shown in Fig. 1, is configured to be able to mount a first dynamic vibration absorber 20.

[0056] The first dynamic vibration absorber 20 includes a casing 21 that houses a first base 28, a first beam 29, a second beam 30, a first mass 31, and a second mass 32, and is attached to the mounting seat 18 of the mounting mechanism 15 with bolts 27. The casing 21 includes a support seat 26 that has a structure for mounting the second dynamic vibration absorber 40. Specifically, the support seat 26 has a plurality of bolt holes 26c (four in this embodiment) that extend upward from the bottom surface and are spaced apart around the axis A.

[0057] The second dynamic vibration absorber 40 includes a second base 42, a cylindrical container 44, a first biasing spring 45, a second biasing spring 46, and a mass body 47, and is attached to the underside of the first dynamic vibration absorber 20 via a support member 41. In other words, the second dynamic vibration absorber 40 is attached to the opposite side of the first dynamic vibration absorber 20 from the piping 1. The support member 41 is attached to the support seat 26 of the first dynamic vibration absorber 20 so as to be threaded into the bolt holes 26c and extend downward. The second base 42 is supported by the support member 41 by passing the support member 41 through the through hole 42a of the second base 42 and tightening a nut 43 to the support member 41.

[0058] The pipe 50 is used to connect the inside of the casing 21 of the first dynamic vibration absorber 20 with the space on the second base 42 side inside the cylindrical container 44 of the second dynamic vibration absorber 40. One end of the pipe 50 is connected to the opening 23a of the casing 21, and the other end is connected to the opening 42b of the second base 42. The pipe 50 is made of an elastically deformable material. However, the pipe 50 may also be made of a non-elastically deformable material.

[0059] The casing 21 of the first dynamic vibration absorber 20 and the cylindrical container 44 of the second dynamic vibration absorber 40 are filled with lubricating oil, which functions as a damping element, between the mass body 47 and the second base 42. The lubricating oil can flow between the two via a pipe 50 due to the difference in internal pressure between the casing 21 and the cylindrical container 44. However, water may be filled instead of lubricating oil, or air may function as a pressure reducing element.

[0060] In the dynamic vibration absorber 10 of the second embodiment configured as described above, the first dynamic vibration absorber 20 capable of suppressing vibration of the pipe 1 in a direction along the XY plane and the second dynamic vibration absorber 40 capable of suppressing vibration of the pipe 1 in the up-down direction intersecting the XY plane can be integrally attached via the attachment mechanism 15 to a desired attachment position of one pipe 1. Therefore, vibration of the pipe 1 in three-dimensional directions can be effectively suppressed.

[0061] The first dynamic vibration absorber 20 further includes a pipe 50 that connects the inside of the casing 21 with the inside of the cylindrical container 44 of the second dynamic vibration absorber 40. This allows the lubricating oil, which functions as a damping resistor, to flow between the inside of the casing 21 of the first dynamic vibration absorber 20 and the inside of the cylindrical container 44 of the second dynamic vibration absorber 40. This allows the damping force of the first dynamic vibration absorber 20 and the second dynamic vibration absorber 40 to be increased.

[0062] The present invention is not limited to the configuration of the above embodiment, and various modifications are possible.

[0063] For example, the casing 21 of the first dynamic vibration absorber 20 and the inside of the cylindrical container 44 of the second dynamic vibration absorber 40 in the first embodiment may be connected by a pipe 50.

[0064] In the second embodiment, the second dynamic vibration absorber 40 may be attached to the attachment mechanism 15, and the first dynamic vibration absorber 20 may be attached to the opposite side of the second dynamic vibration absorber 40 from the piping 1.

[0065] The first dynamic vibration absorber 20 may not have the casing 21, and the first base 28, the first beam 29, the second beam 30, the first mass 31, and the second mass 32 may be exposed.

[0066] The second dynamic vibration absorber 40 may not include the cylindrical container 44, and may have a configuration in which the first biasing spring 45, the second biasing spring 46, and the mass body 47 are exposed. [Explanation of symbols]

[0067] 1, 1A, 1B piping 10 Dynamic vibration absorber for piping 15 Mounting mechanism 16 U-bolt (fastening member) 16a Arc section 16b Bolt shank 17 Nut 18, 18A, 18B Mounting seat 18a Groove 18b Through hole 18c bolt holes 20 1st dynamic vibration absorber 21 Casing 22 Casing body 22a Through hole 23 Cover 23a Open hole 24 Plug body 25 Latch seat 25a Positioning groove 25b Through hole 26 Support seat 26a Positioning groove 26b Through hole 26c bolt hole 27 volts 28 1st base 28a through hole 28b bolt hole 29 1st beam section 30 2nd beam part 31 First mass body 31a Bolt hole 31b Nut 32 Second mass body 32a Bolt hole 32b Nut 34 Latch mechanism (positioning mechanism) 35 coil spring 36 rolling elements 37 Storage Cave 38 Positioning recess 40 2nd dynamic vibration absorber 41 Support member 42 Second base 42a through hole 42b hole 43 Nut 44 Cylindrical container 45 First biasing spring 46 Second biasing spring 47 Mass body (third mass body) 48 Sealing material 50 Pipe (communicating pipe) X: Direction in which the piping installation position extends (first direction) Y: Direction perpendicular to the pipe installation position (second direction) Z Vertical direction (3rd direction)

Claims

1. a first dynamic vibration absorber and a second dynamic vibration absorber attached to the piping; The first dynamic vibration absorber is A first base portion; a first beam portion protruding from the first base portion toward one side of a predetermined direction along a plane including a first direction in which the attachment position of the piping extends and a second direction intersecting the first direction; a second beam portion protruding from the first base portion toward the other side in the predetermined direction; a first mass attached to the first beam; a second mass attached to the second beam portion; and The second dynamic vibration absorber is a second base portion disposed at a distance from the piping in a third direction intersecting the plane; a first biasing spring disposed on the second base portion on the piping side; a second biasing spring disposed on the pipe side at a distance from the first biasing spring in the third direction; a third mass sandwiched between the first biasing spring and the second biasing spring; It has The dynamic vibration absorber for piping further comprises an attachment mechanism for attaching the first dynamic vibration absorber and the second dynamic vibration absorber to the piping.

2. The attachment mechanism includes: a U-shaped fastening member surrounding a portion of the piping; a mounting seat to which the first base portion or the second base portion is attached and which can be attached to the piping in a pressure-welded state by fastening the fastening member; 2. The dynamic vibration absorber for piping according to claim 1, comprising:

3. 3. The dynamic vibration absorber for piping according to claim 2, wherein the first dynamic vibration absorber and the second dynamic vibration absorber are respectively attached to different attachment mechanisms.

4. one of the first dynamic vibration absorber and the second dynamic vibration absorber is attached to the attachment mechanism; 3. The dynamic vibration absorbing device for piping according to claim 2, wherein the other of the first dynamic vibration absorber and the second dynamic vibration absorber is attached on the opposite side of the mounting mechanism from the one of the first dynamic vibration absorber and the second dynamic vibration absorber.

5. the first dynamic vibration absorber has a casing that houses the first base portion, the first beam portion, the second beam portion, the first mass body, and the second mass body; the second dynamic vibration absorber includes a cylindrical container having one end attached to the second base portion and an open end on the piping side, and a sealing member that seals between the third mass and the cylindrical container, a communication pipe that communicates the inside of the casing with the second base side in the cylindrical container, The dynamic vibration absorber for piping according to any one of claims 1 to 4.

6. the first dynamic vibration absorber has a casing that houses the first base portion, the first beam portion, the second beam portion, the first mass body, and the second mass body; the casing is attached to the attachment mechanism so as to be rotatable about a rotation axis extending along the third direction, The casing and the mounting mechanism are provided with positioning mechanisms for determining directions in which the first beam portion and the second beam portion extend. The dynamic vibration absorber for piping according to any one of claims 1 to 4.

7. the second dynamic vibration absorber has a support member that supports the second base portion, The dynamic vibration absorber for piping according to claim 1 , wherein the support member is capable of adjusting a distance between the second base portion and the mounting mechanism.

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