Vibration damping device with overload protection function

Abstract

To provide a vibration damping device with an overload protection function.SOLUTION: A vibration damping device 1 includes: a first support member 2 connected to one of two members A, B that are vibration damping targets; and a second support member 3 connected to the other of the two members A, B. The vibration damping device suppresses relative displacement in an axial direction between the first and second support members 2, 3 generated along with relative vibration in a linear direction of the two members A, B by using rotational inertia resistance or hydraulic resistance. The first support member 2 includes: a first member 5 on a base end side; and a second member 6 on a tip side that receives the first member 5 to enable relative movement in the axial direction. A shear ring 7 that is broken when a predetermined level or more of force in a compression direction or a tensile direction is applied in the axial direction so as to allow the relative movement of the first member 5 and the second member 6 is interposed between the first member 5 and the second member 6.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a rotational inertia vibration damping device or hydraulic vibration damping device that has a protective function to prevent serious damage to the device or the supported object when a load greater than expected is applied. [Background technology]

[0002] Conventionally, known vibration damping devices for suppressing linear vibration between two members include a rotational inertia vibration damping device (e.g., Patent Document 1) that converts vibration into rotational motion using a ball screw and a ball nut screwed onto it, rotating an inertial body integrally connected to the ball screw, and suppressing vibration between the two members to be damped by the inertia moment of the inertial body; and a hydraulic vibration damping device (e.g., Patent Document 2) that connects two oil chambers partitioned by a piston inserted into a cylinder with an orifice of constant cross-sectional area, and uses the hydraulic resistance generated when oil passes through the orifice due to movement of the piston caused by vibration as a damping force. Patent document 3 describes a rotary inertia mass damper that is equipped with an overload adjustment mechanism that allows relative axial movement between the spline shaft and the screw shaft when an external force that exceeds a predetermined limit value acts in the axial direction, and Patent document 4 describes a hydraulic vibration control device in which a relief valve is provided in a flow path that passes through the piston to prevent an increase in the load acting on the device in the event of an earthquake of a predetermined level or above, and which opens to release the pressure when a pressure greater than the design pressure is applied. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-255752 A [Patent Document 2] Japanese Patent Application Publication No. 5-321968 [Patent Document 3] JP 2017-15133 A [Patent Document 4] JP 5-59840 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a vibration damping device to which an overload protection function is added by using a mechanism different from the load limiting means in the above-mentioned conventional rotary inertia vibration damping device or hydraulic vibration damping device. [Means for solving the problem]

[0005] In the following description, reference will be made to the figures of the accompanying drawings, in which: FIG. In order to solve the above problems, the vibration damping device 1 of the present invention is a vibration damping device that includes a first support member 2 connected to one of two members A and B that are vibration damping targets, and a second support member 3 connected to the other of the two members A and B, and that suppresses the relative axial displacement between the first and second support members 2 and 3 that occurs due to linear relative vibration between the two members A and B by using rotational inertia resistance or hydraulic resistance. The first support member 2 includes a first member 5 on the base end side and a second member 6 on the tip side that receives the first member 5 so as to be relatively movable in the axial direction. A shear ring 7 is interposed between the first member 5 and the second member 6, which breaks when a compressive or tensile force of a predetermined value or more is applied in the axial direction, thereby allowing the first member 5 and the second member 6 to move relatively. Effect of the Invention

[0006] According to the present invention, when a compressive or tensile force of a predetermined magnitude or greater acts between the first support member 2 and the second support member 3 of the vibration damping device 1, the shear ring 7 breaks, thereby avoiding damage to the vibration damping device itself and / or the equipment to be damped. [Brief description of the drawings]

[0007] [Figure 1] 1 is a front view of a vibration damping device according to the present invention, with a portion of the main portion cut away. [Diagram 2] FIG. 2 is a cross-sectional view taken along line II-II of FIG. [Diagram 3]1A is a front view of a rotary inertia vibration damping device to which the present invention is applied, and FIG. 1B is a front view of a hydraulic vibration damping device to which the present invention is applied. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] An embodiment of the present invention will be described with reference to the drawings. The vibration damping device 1 of the present invention is configured as a rotational inertia vibration damping device 101 shown in FIG. 3(A) or a hydraulic vibration damping device 102 shown in FIG. 3(B). Both vibration damping devices 101, 102 include a first support member 2 connected to one of two members A, B to be damped (piping system A in the illustrated example), and a second support member 3 connected to the other member B (structure B such as a building in the illustrated example). In the example of the rotational inertia vibration damping device 101 in FIG. 3(A), the side supporting an inertial body and a ball screw (not shown) is the first support member 2, and the ball nut side is the second support member. In the example of the hydraulic vibration damping device 102 in FIG. 3(B), the hydraulic cylinder side is the first support member 2, and the piston rod side is the second support member. Both are vibration damping devices that suppress the axial relative displacement between the first and second support members 2, 3 that occurs due to linear relative vibration between members A and B, by using rotational inertia resistance in the rotational inertia damping device 101, and by using hydraulic resistance in the hydraulic vibration damping device 102.

[0009] 1, the first support member 2 of the vibration damping device 1 includes a cylindrical casing 4 that houses an inertial body and a ball screw or that houses oil, a columnar first member 5 that extends outward from a lid 41 of the casing, and a roughly cylindrical second member 6 that receives the first member 5 so as to be relatively movable in the axial direction. A shear ring 7 is interposed between the first member 5 and the second member 6, which breaks when a compressive or tensile force of a predetermined magnitude or greater is applied in the axial direction, allowing relative movement between the two.

[0010] The first member 5 comprises a rod portion 51 and a head portion 52 at the tip of the rod portion 51, the head portion 52 having a slightly larger diameter than the rod portion 51, and two annular grooves 53 spaced apart in the axial direction on the outer periphery of the rod portion 51. Shear rings 7, each with an outer periphery protruding from the outer periphery of the rod portion 51, are fitted into the annular grooves 53.

[0011] The second member 6 comprises a connecting pipe 61 whose outer end is connected to the piping system A, a cylindrical adapter 62 fixed to the inner end of the connecting pipe 61, and an annular cutting block 63 removably fixed to the inner end of the adapter 62 by bolts 8.

[0012] The adapter 62 receives the rod portion 51 and the head portion 52 of the first member 5 so as to be slidable in the axial direction. The outer periphery of the head portion 52 is in airtight contact with the inner periphery of the adapter 62 via the seal material 10.

[0013] The cutting block 63 fits inside the two shear rings 7, and its inner periphery is in airtight contact with the outer periphery of the rod portion 51 via a seal material 9. In the illustrated embodiment, the cutting block 63 and the shear ring 7 each consist of a pair of halves.

[0014] Therefore, first and second air chambers 11, 12 are formed on both sides of the head portion 52. The adapter 62 has vent holes 13, 14 that communicate the first and second air chambers 11, 12 with the outside air.

[0015] When the first member 5 and the second member 6 are subjected to vibration in the compressive or tensile direction, for example, with a force 1.5 times or more the rated load of the device, the shear ring 7 designed into the weakest part of the vibration damping device 1 breaks, and the second support member 3 is protected from damage due to overload.

[0016] After the shear ring 7 breaks, the vibration control device 1 retains the function of receiving reaction force due to air resistance in the air chambers 11, 12, while the first member 5 and the second member 6 move relative to each other, causing the air chambers 11, 12 to expand or contract. At this time, the air vents 13, 14 adjust the internal pressure of the air chambers 11, 12, and provide an air cushion that buffers the impact on the piping system A.

[0017] The vibration damping device 1 can be easily restored after the shear ring 7 has broken by removing the cutting block 63, replacing the shear ring 7, and reattaching the cutting block 63. [Explanation of symbols]

[0018] 1. Vibration control device 2. First Support Member 3 Second Support Member 4 Cylindrical casing 41 Lid 5 First member 51 Rod section 52 Head 53 Circular groove A Piping system 6 Second member 61 Connecting Pipe 62 Adapter 63 Cutting Block 7 Shear Ring 8 Volts 9. Sealing materials 10. Sealing material 11 First air chamber 12 Second Air Chamber 13 First Vent 14 Second Vent 101 Rotational inertia vibration control device 102 Hydraulic vibration control device A Vibration control target (piping system) B. Vibration control target (structure)

Claims

1. A vibration damping device comprising: a first support member connected to one of two vibration-damping target members; and a second support member connected to the other of the two vibration-damping target members, the vibration damping device suppressing, by rotational inertia resistance or hydraulic resistance, a relative axial displacement between the first and second support members that occurs due to a linear relative vibration between the two vibration-damping target members, the first support member includes a first member on a base end side and a second member on a tip end side that receives the first member so as to be relatively movable in an axial direction; A vibration damping device with overload protection function, characterized in that a shear ring is interposed between the first member and the second member, and breaks when a compressive or tensile force of a predetermined amount or more is applied in the axial direction, allowing relative movement between the first member and the second member.

2. The first member has two annular grooves on its outer periphery, the two annular grooves being spaced apart in the axial direction, and the shear rings are fitted into the annular grooves, respectively; The vibration damping device with overload protection function as described in claim 1, characterized in that the second member has an annular cutting block removably fixed to its end on the first member side, and the cutting block is arranged to fit inside the two shear rings.

3. The cutting block is provided so as to be airtightly fitted to an outer periphery of the first member via a sealing material, The first member has a head portion at a tip end thereof, which is airtightly fitted to an inner periphery of the second member, and is provided so as to form first and second air chambers on both axial sides of the head portion, The vibration damping device with overload protection function as described in claim 2, characterized in that the second member has an air vent that connects the first and second air chambers to the outside air, thereby cushioning the relative movement between the first and second members after the shear ring is destroyed by air resistance.

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