JP2010071307A - Dynamic vibration absorber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dynamic vibration absorber which is suitable for characteristic adjustment when installed in field or readjustment after secular change. <P>SOLUTION: The dynamic vibration absorber 1, which absorbs vibration applied to a vibration deadening object by vibrating a rod spring 3 to which a spindle 4 is attached in lower end, and damps a vibration of the rod spring 3 by a magnetic damper 14 constituted with the spindle 4, comprises a frame 2 in which a hole inserted by the rod spring 3 is arranged, an inner cylinder body 5 fixing an upper part of the rod spring 3 to the frame 2, and an outer cylinder body 6 forming a fulcrum point when the rod spring 3 vibrates by contacting the rod spring 3 so that the vibration of the rod spring 3 may be regulated in one section on the axis of the rod spring 3. Furthermore, damping property is adjusted by expanding/contracting a space between the spindle 4 and permanent magnet 8 in such a way that a fixed position B of the rod spring 3 in the frame 2 is moved vertically by rotating the inner cylinder body 5. Additionally, spring characteristic is adjusted by telescoping a distance from the fulcrum point to the spindle 4 in such a way that the fulcrum point is moved vertically by rotating the outer cylinder body 6. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a dynamic vibration absorber that absorbs vibration applied to a structure (damping object) by vibrating a bar spring among vibration reduction devices used in architecture, civil engineering, and general structures.

  Conventionally, when controlling vibration control of a structure, the structure is supported by anti-vibration rubber to prevent the entire structure from shaking, or a weight and a spring are combined to synchronize with the natural period of the structure. A mass damper (dynamic vibration absorber) or the like that does not transmit disturbance to the structure is used.

  Among them, since the dynamic vibration absorber uses resonance in principle, if a large disturbance is applied, the vibration of the weight increases, which may cause damage to the vibration absorber or damage to the vibration damping object. For this reason, it is common to adopt a structure in which an energy absorbing device such as a viscous damper or an oil damper is added to quickly reduce shaking.

  In addition, since the dynamic vibration absorber is a device that absorbs vibrations in the direction of vibration using resonance characteristics, the characteristics of the weights and springs that support the weights and vibrations according to the direction and magnitude of the target vibrations. Therefore, it is necessary to measure the vibration characteristics of the structure causing the vibration problem prior to the design and manufacturing stage, and to reflect them in the design and manufacturing.

  As described above, the dynamic vibration absorber is manufactured so as to produce the maximum effect under the designed conditions. However, in the actual installation site, there are various reasons (for example, the installation location of the machine that becomes the vibration source). In many cases, the expected effect cannot be obtained due to the change in the load or the load applied to the vibrating beam or floor. Furthermore, it is known that the natural period of a structure changes with age. For example, even when a crack that causes structural problems on walls and beams due to earthquake motion is generated, the structure The natural period of has shifted to the long period side compared to the time of new construction.

  In order to allow such a natural period shift in the field and use a relatively wide frequency range as a damping region, a multi-mass damper in which a plurality of mass dampers whose natural periods are gradually shifted may be used. . However, since such a multi-mass damper is increased in size, the workability is poor and the cost tends to be high.

  Therefore, as a configuration in which vibration characteristics can be adjusted in the field without causing deterioration of workability and cost increase, for example, Patent Document 1 includes a weight at one end and is made of a material having a large vibration damping capability. There has been proposed a dynamic vibration absorber that includes a bar spring, a clamping part that clamps the other end of the bar spring, and an adjustment mechanism that changes the height of the clamping position of the bar spring. This dynamic vibration absorber changes the distance from the clamping position to the weight (the range in which the bar spring effectively acts as a spring) by changing the height of the position where the bar spring is clamped, thereby improving the spring characteristics. It can be adjusted.

  However, since this dynamic vibration absorber depends on the vibration damping ability of the material of the rod spring with respect to the damping characteristic, it cannot be adjusted appropriately and there is a possibility that optimum damping cannot be given. For this reason, when a large vibration is received, the resonating weight may shake greatly, resulting in damage to the device or the structure, and cannot be said to have been subjected to accurate tuning.

  Patent Document 2 proposes a dynamic vibration absorber that adjusts the spring characteristics by changing the attachment position of the weight, selecting the mass of the weight, or changing the cross-sectional shape of the spring member. ing. However, also in this dynamic vibration absorber, since the damping characteristic uses the damping ratio of the spring member itself, the damping adjustment cannot be performed, and it is difficult to perform appropriate tuning.

  On the other hand, in Patent Document 3, two bar springs extending from both side surfaces of the cover, weights supported by these bar springs, a permanent magnet attached to the inside of the weight, and fixed to the cover, There has been proposed a dynamic vibration absorber provided with a conductor plate arranged in the vicinity of a permanent magnet. In this dynamic vibration absorber, a magnetic damper is constituted by a permanent magnet on the weight side and a conductor plate on the cover side, and a damping action is obtained by the magnetic damper. Therefore, the dynamic vibration absorber described in Patent Documents 1 and 2 In contrast, the damping characteristic does not depend only on the vibration damping capacity of the bar spring.

  However, this dynamic vibration absorber is also required to change the characteristics of both the spring characteristics and the damping characteristics, because it is indispensable to change the springs and conductor plates. It is not suitable for on-site adjustment or subsequent readjustment.

JP 2005-48791 A JP 2004-190314 A Japanese Patent Laid-Open No. 11-257421

  As described above, the conventional dynamic vibration absorber does not have a structure that can be easily adjusted after the installation at the site or after the secular change, and the capacity of the dynamic vibration absorber is fully utilized. There wasn't. Even if the structure is adjustable, there are many adjustment mechanisms that are complicated or time-consuming, and there is no structure that can easily adjust both the spring characteristics and the damping characteristics.

  Therefore, the present invention has been made in view of the above problems, and an object thereof is to provide a dynamic vibration absorber suitable for characteristic adjustment when installed on the site and readjustment after aging.

  In order to achieve the above-mentioned object, the present invention absorbs vibration applied to the object to be controlled by vibrating a bar spring having a weight attached to one end thereof, and the bar spring by a damper configured between the weight spring and the object. A dynamic vibration absorber for attenuating the vibration of the bar spring, the frame, a fixing portion for fixing a part of the other end of the bar spring to the frame, and a part of the bar spring on the axis thereof Abutting so as to restrict movement in a direction perpendicular to the axial direction of the bar spring, and a fulcrum forming part that forms a fulcrum when the bar spring vibrates, and the frame via the fixing part A first adjusting unit that adjusts a damping characteristic of the dynamic vibration absorber by moving the bar spring in an axial direction of the bar spring and expanding or reducing a distance between the weight and a predetermined position of the damper; The contact position of the fulcrum forming part with respect to the bar spring Is moved in the axial direction of the roots, characterized in that it comprises a second adjustment unit for adjusting the spring characteristic of the distance by stretching animal absorber from the fulcrum to the weight.

  And according to this invention, after providing separately the fixing | fixed part which fixes a bar spring to a flame | frame, and the fulcrum formation part which forms the fulcrum at the time of a bar spring vibrating, a frame is made by the 1st adjustment part. In contrast, the damping characteristic of the dynamic vibration absorber is adjusted by moving the bar spring in the axial direction thereof, and the contact position of the fulcrum forming portion with respect to the bar spring is moved in the axial direction of the bar spring by the second adjustment unit. The spring characteristics of the dynamic vibration absorber can be adjusted. For this reason, it is possible to easily adjust the dynamic vibration absorber at the time of construction on site, and it is possible to easily readjust even when the natural period fluctuates due to aging of the structure.

  In the above-described dynamic vibration absorber, an inner cylinder that is screwed to the outer peripheral surface of the bar spring on the inner peripheral surface and is screwed to the frame on the outer peripheral surface on one end side, and the inner cylindrical body on the inner peripheral surface on one end side And an outer cylindrical body provided with a bar spring restraint portion that abuts the bar spring and forms the fulcrum on the other end side. The outer cylinder is screwed with the inner peripheral surface of the inner cylinder so as to be movable in the axial direction of the bar spring, and the outer cylinder is screwed with the outer peripheral surface of the inner cylinder so as to be movable in the axial direction of the bar spring. Can be configured.

  According to the above configuration, since the first and second adjustment units can be configured by the inner cylinder and the outer cylinder, the dynamic vibration absorber according to the present invention can be configured with a simple structure, and the manufacturing cost can be kept low. It becomes possible. Further, the adjustment of the spring characteristic and the damping characteristic can be performed only by moving the inner cylinder body and the outer cylinder body in the axial direction of the bar spring, so that adjustment after assembly can be facilitated. .

  In the dynamic vibration absorber, the bar spring is slid in the axial direction of the bar spring while restricting the bar spring from moving in a direction perpendicular to the axial direction of the bar spring. It can be movable. According to this configuration, it is possible to freely change the positions of the bar spring and the outer cylinder while appropriately forming the fulcrum on the axis of the bar spring.

  In the dynamic vibration absorber, the bar spring is formed in a cylindrical shape having a through hole, and is screwed with the frame at the outer peripheral surface on the other end side, and the dynamic vibration absorber is inserted into the through hole. An inner rod body, a large-diameter portion provided on the inner rod body and contacting the inner circumferential surface of the rod spring to form the fulcrum, and screwed into each of the rod spring and the inner rod body; A connecting portion for connecting the spring and the inner rod body, the rod spring being screwed to the connecting portion so as to be movable in the axial direction of the rod spring, and the inner rod body being in the axial direction of the rod spring. And can be configured to be screwed with the connecting portion.

  According to the said structure, a 1st adjustment part can be comprised with the outer peripheral surface of a bar spring, and a flame | frame, and a 2nd adjustment part can be comprised with an inner stick body and a connection part. For this reason, the dynamic vibration absorber concerning this invention can be comprised with a simple structure, and it becomes possible to hold down manufacturing cost low. Furthermore, since adjustment of the spring characteristics and damping characteristics can be performed only by moving the bar spring and the inner bar body in the axial direction of the bar spring, adjustment after assembly can be facilitated.

  In the dynamic vibration absorber, the large-diameter portion is slidable in the axial direction of the bar spring while restricting the bar spring from moving in a direction perpendicular to the axial direction of the bar spring. It can comprise so that it may contact | abut to the internal peripheral surface of a spring. According to this configuration, it is possible to freely change the position of the large diameter portion while appropriately forming the fulcrum on the axis of the bar spring.

  In the above-described dynamic vibration absorber, the damper is arranged such that either the conductor or the magnet attached to the weight and the conductor or the magnet are disposed at a predetermined interval from the conductor or the magnet. It can be set as the magnetic damper comprised with either one of these.

  Further, in the above-described dynamic vibration absorber, the damper is disposed at a predetermined interval from a container having an upper surface opened, a viscous body accommodated in the container, and a bottom surface of the container, and is immersed in the viscous body. It can also be a viscous damper composed of the weight.

  As described above, according to the present invention, it is possible to provide a dynamic vibration absorber suitable for characteristic adjustment when installed on the site and readjustment after aging.

  Next, embodiments of the present invention will be described with reference to the drawings. First, the form using the magnetic damper as a damper which constitutes the dynamic vibration absorber concerning the present invention is explained.

  FIG. 1 is a cross-sectional view showing a first embodiment of a dynamic vibration absorber using a magnetic damper according to the present invention, and FIG. 2 is an enlarged view of a portion A in FIG.

  As shown in FIG. 1, the dynamic vibration absorber 1 has a frame 2 having a predetermined width in a direction perpendicular to the paper surface and provided with a hole 2 a in the upper part, and is suspended vertically from the upper part of the frame 2. The rod spring 3 to be supported, the cylindrical inner cylindrical body 5 disposed between the frame 2 and the bar spring 3, the cylindrical outer cylindrical body 6 screwed with the inner cylindrical body 5, and the frame 2 are supported. A support plate 7 and a permanent magnet 8 disposed on the support plate 7 are provided.

  The bar spring 3 is a spring member that vibrates in response to an external force such as an earthquake, and has a simple configuration using, for example, a round bar. Since this bar spring 3 has a circular cross section, the bar spring 3 is excellent in that it has no directivity and has equivalent spring characteristics in deformation in any direction. A male screw 3a for fixing the bar spring 3 is threaded on the outer peripheral surface of the bar spring 3 (see FIG. 2), and a weight 4 having a predetermined mass is attached to the lower end of the bar spring 3.

  A conductive plate 4 a is attached to the lower surface of the weight 4, and the permanent magnet 8 constitutes a magnetic damper 14. The magnetic damper 14 attenuates the vibration of the bar spring 3 by the Lorentz force generated when the conductive plate 4 a crosses the magnetic field of the permanent magnet 8. In addition, since it can be used in a non-contact manner, there is no wear on the attenuation portion, so that it is excellent in maintainability, and further has characteristics such as almost no temperature dependence and deterioration over time. The conductive plate 4a may be any plate that generates an electromagnetic induction effect in cooperation with a permanent magnet. For example, a copper plate, a stainless plate, an aluminum plate, or the like can be used.

  The inner cylinder 5 is used to connect the bar spring 3 and the outer cylinder 6 to the frame 2, and as shown in FIG. 2, a female screw 5 a and a male screw 5 b are threaded on each of the inner peripheral surface and the outer peripheral surface. The Among these, the female screw 5 a on the inner peripheral surface side is screwed with the male screw 3 a of the bar spring 3. On the other hand, the male screw 5 b on the outer peripheral surface side is screwed with the female screws 11 a and 12 a of the lock nuts 11 and 12 respectively attached to the upper surface and the lower surface of the frame 2, thereby fixing the inner cylinder 5 to the frame 2.

  The internal thread 5a on the inner peripheral surface side is not necessarily formed on the entire inner peripheral surface, and may be formed only on the upper portion of the inner peripheral surface as shown in FIG. As shown in FIG. 3 (b), the adjustment nut 10 is integrally disposed on the inner cylinder 5, and the inner nut 5 is not threaded with an internal thread, and the adjustment nut 10 is not screwed. A female screw 10a may be threaded on the inner peripheral surface of the ten.

  Returning to FIG. 2, the outer cylinder 6 is provided to move the position of the fulcrum when the bar spring 3 vibrates in the vertical direction, and an internal thread 6 a is threaded on the inner peripheral surface. The female screw 6 a is screwed with the male screw 5 b on the outer peripheral surface side of the inner cylinder 5, thereby connecting the outer cylinder 6 to the lower portion of the inner cylinder 5.

  A lock nut 13 for fixing the position of the outer cylinder body 6 is provided at the upper end portion of the outer cylinder body 6, and a top view circle provided around the through hole 9 a through which the bar spring 3 is inserted at the lower end portion. An annular bar spring restraint 9 is provided. The bar spring restraining portion 9 is in contact with the bar spring 3 at a part on the axis of the bar spring 3 to form a fulcrum when the bar spring 3 vibrates. Here, the diameter of the through-hole 9a is set in accordance with the outer diameter of the bar spring 3, and a certain amount of tightening force is applied to the bar spring 3 to restrict the vibration of the bar spring 3, while It is set to a size that allows sliding in the direction.

  In addition, in the bar spring restraint part 9, although it can contact | abut to the bar spring 3 by making the diameter of the through-hole 9a correspond with the outer diameter of the bar spring 3, on the other hand, it prevents the bar spring 3 from sliding. It will be. Therefore, the diameter of the through hole 9a is set to be slightly larger than the outer diameter of the bar spring 3 to ensure a margin for the bar spring 3 to slide, and then from the outer peripheral surface side of the outer cylinder 6 in the horizontal direction. A pin (not shown) may be inserted to pin the outer cylinder 6, the bar spring restraint portion 9, and the bar spring 3.

  Next, operation | movement of the dynamic vibration damper 1 which has the said structure is demonstrated, referring FIGS. 4-7.

  When adjusting the spring characteristics of the dynamic vibration absorber 1 to the short cycle side, as shown in FIG. 4, the inner cylinder 5 and the outer cylinder 6 are not changed without changing the fixing position B of the bar spring 3 in the frame 2. And the fulcrum C is moved downward.

  Specifically, the rod spring 3 and the inner cylinder 5 are fixed so as not to rotate, and in this state, only the outer cylinder 6 is rotated to move the outer cylinder 6 downward. As a result, the bar spring restraint portion 9 can be slid downward, and the distance L from the fulcrum C to the weight 4 is shortened while the distance W between the weight 4 and the permanent magnet 8 is maintained at a constant size. The spring characteristic of the dynamic vibration absorber 1 can be shifted to the short cycle side.

  On the other hand, when the spring characteristic is adjusted to the long period side, as shown in FIG. 5, the screwing range of the inner cylinder 5 and the outer cylinder 6 is increased while the fixed position B is kept at the same position. The fulcrum C is moved upward. Also in this case, the rod spring 3 and the inner cylinder 5 are fixed so as not to rotate, and only the outer cylinder 6 is rotated to move the outer cylinder 6 upward. As a result, the bar spring restraint portion 9 can be slid upward, and the distance L from the fulcrum C to the weight 4 is increased while maintaining the distance W between the weight 4 and the permanent magnet 8 at a constant size. The spring characteristic of the dynamic vibration absorber 1 can be shifted to the long period side.

  On the other hand, when the damping characteristic is increased, as shown in FIG. 6, the fixed position B of the bar spring 3 in the frame 2 is set to the position of the bar spring 3 while keeping the distance L from the fulcrum C to the weight 4 constant. The rod spring 3 is moved downward to bring the weight 4 closer to the permanent magnet 8.

  In changing the fixing position B, first, with the inner cylinder 5 fixed so as not to rotate, only the bar spring 3 is rotated and the bar spring 3 is moved downward. However, with this alone, the height of the bar spring restraint portion 9 does not change, and only the bar spring 3 is lowered, so that the fulcrum C moves to the upper side of the bar spring 3 and the distance L from the fulcrum C to the weight 4. Becomes longer, and the spring characteristic of the dynamic vibration absorber 1 is shifted to the long period side.

  Therefore, the outer cylinder 6 is rotated while being fixed so that the inner cylinder 5 does not rotate, and the outer cylinder 6 is lowered by the same amount as the lowering amount of the bar spring 3. Thus, the position of the fulcrum C is moved downward by the amount of the bar spring 3 being lowered, and the distance L from the fulcrum C to the weight 4 is kept constant. Thereby, only the damping characteristic can be increased without changing the spring characteristic of the dynamic vibration absorber 1.

  On the other hand, when reducing the damping characteristic, as shown in FIG. 7, the distance L from the fulcrum C to the weight 4 is not changed, the fixed position B is moved to the lower side of the bar spring 3, and the bar spring 3 is moved. The weight 4 is raised to move away from the permanent magnet 8. Also in this case, after the rod spring 3 is lifted, the outer cylinder 6 is lifted by the same amount as the rod spring 3 is lifted, and the distance L from the fulcrum C to the weight 4 is increased before the rod spring 3 is lifted. Return to length. As a result, the distance between the conductive plate 4a and the permanent magnet 8 can be increased in a state where the distance L from the fulcrum C to the weight 4 is kept constant, and the damping characteristic can be reduced without changing the spring characteristic of the dynamic vibration absorber 1. Only can be reduced.

  As described above, according to the present embodiment, the fixing mechanism for fixing the bar spring 3 to the frame 2 and the fulcrum forming mechanism for forming the fulcrum C when the bar spring 3 vibrates are provided separately. Since the fixed position B and the fulcrum C can be changed independently, both the spring characteristics and the damping characteristics can be adjusted, and the characteristics can be adjusted separately. In addition, adjustment of the spring characteristics and the like can be performed simply by moving the bar spring 3, the inner cylinder 5 and the outer cylinder 6 in the vertical direction, so that the dynamic vibration absorber 1 can be easily adjusted at the time of construction on site. Even if the natural period fluctuates due to aging of the structure, it can be readjusted easily.

  Next, a second embodiment of the dynamic vibration absorber using the magnetic damper according to the present invention will be described with reference to FIGS. In these drawings, the same components as those in FIGS. 1 to 7 are denoted by the same reference numerals, and description thereof is omitted.

  As shown in FIG. 8, the dynamic vibration absorber 20 is inserted into the frame 2, a bar spring 21 that vertically hangs down from the upper part of the frame 2, and a weight 4 attached to the lower end, and the bar spring 21. An inner rod body 22, a bar spring 21, a connecting portion 23 disposed on the upper portion of the inner rod body 22, a support plate 7, a permanent magnet 8, and the like are provided.

  As shown in FIG. 9, the bar spring 21 has a cylindrical shape with a through hole 21a provided at the center, and a male screw 21b is threaded on the outer peripheral surface of the upper portion thereof. The male screw 21 b is fixed to the frame 2 by screwing with the female screw 2 b screwed into the inner peripheral surface of the hole 2 a of the frame 2.

  A rod-shaped inner rod body 22 is inserted into the through hole 21a of the rod spring 21, and this inner rod body 22 is provided to move the position of a fulcrum when the rod spring 21 vibrates in the vertical direction. A male screw 22a is threaded on the upper portion of the inner rod body 22, and a large-diameter portion 22b that abuts the inner peripheral surface of the through hole 21a on the side surface is provided on the lower end portion.

  The large diameter portion 22b is in contact with a part of the axial line of the bar spring 21 so as to restrict the horizontal movement of the bar spring 21 in the same manner as the bar spring restraining portion 9 of FIG. Form a fulcrum when vibrating. Here, the outer diameter of the large-diameter portion 22b is set in accordance with the diameter of the through hole 21a, and a certain amount of tightening force is applied to the rod spring 21 to restrict vibration of the rod spring 21, but the large-diameter portion 22b. Is set to a size capable of sliding in the vertical direction within the bar spring 21.

  The connecting portion 23 is provided for connecting the bar spring 21 and the inner rod body 22. A female screw 23a that is screwed with a male screw 22a threaded on the outer peripheral surface of the inner rod body 22 is threaded on the upper portion of the connecting portion 23, and a female screw that is screwed with the male screw 21b of the bar spring 21 is threaded on the lower portion. 23b is threaded. Then, the internal threads 22 a and 23 b are engaged with the external threads 22 a of the internal rod body 22 and the external threads 21 b of the bar spring 21, thereby connecting the internal rod body 22 and the bar spring 21 through the connecting portion 23.

  Next, operation | movement of the dynamic vibration damper 20 which has the said structure is demonstrated, referring FIGS. 10-11.

  When adjusting the spring characteristics of the dynamic vibration absorber 20, as shown in FIG. 10, without changing the fixing position B of the frame 2 with respect to the bar spring 21, the inner rod body 22 is moved up and down to move the fulcrum C up and down. Move.

  Specifically, the rod spring 21 is fixed so as not to rotate, and in this state, only the inner rod body 22 is rotated and moved up and down, and the contact position between the large diameter portion 22b and the inner peripheral surface of the rod spring 21 is determined. Move up and down. As a result, the distance L from the fulcrum C to the weight 4 can be expanded and contracted while the distance W between the weight 4 and the permanent magnet 8 is maintained at a constant size, and only the spring characteristics can be obtained without changing the damping characteristics. Can be adjusted.

  The relationship between the distance L and the spring characteristics is the same as in the case shown in FIGS. 4 and 5, and by shortening the distance L, the spring characteristics can be shifted to the short period side, By increasing the distance L, the spring characteristics can be shifted to the long period side.

  On the other hand, when adjusting the damping characteristic, as shown in FIG. 11, while the distance L from the fulcrum C to the weight 4 is kept constant, the fixed position B of the bar spring 21 in the frame 2 is moved up and down to The spring 21 is moved up and down to increase or decrease the distance W between the conductive plate 4 a and the permanent magnet 8.

  In changing the fixing position B, the inner rod body 22 is fixed so as not to rotate between the connecting portion 23 and the inner rod body 22, and the bar spring 21 is interposed between the connecting portion 23 and the bar spring 21. Fix so that does not rotate. In this state, the bar spring 21 is rotated between the frame 2 and the bar spring 21, and the bar spring 21 is moved up and down to move the position of the weight 4 up and down.

  At the time described above, the inner rod body 22 rotates integrally with the rod spring 21 through the connecting portion 23 and moves up and down together with the rod spring 21. For this reason, the position of the fulcrum C is also raised and lowered by the same amount as the raising and lowering amount of the bar spring 21, and the distance L from the fulcrum C to the weight 4 is kept constant. Therefore, without changing the distance L from the fulcrum C to the weight 4, the interval W between the conductive plate 4a and the permanent magnet 8 can be expanded and reduced, and only the attenuation characteristic can be adjusted.

  As described above, also in the present embodiment, the fixing mechanism that fixes the bar spring 21 to the frame 2 and the fulcrum formation mechanism that forms the fulcrum C when the bar spring 21 vibrates are separately provided, and the fixing position is also fixed. Since B and fulcrum C can be changed independently, the same operations and effects as in the first embodiment can be obtained.

  In the above-described embodiment, the case where the bar springs 3 and 21 are suspended in the vertical direction from the upper surface of the frame 2 is illustrated, but the bar springs 3 and 21 may extend horizontally from the side surface of the frame 2.

  Next, the case where the damper which comprises the dynamic vibration damper concerning this invention is a viscous damper is demonstrated, referring FIG. In the present embodiment, the configuration for adjusting the spring characteristics and the damping characteristics is the same as that of the dynamic vibration absorber 1 using the magnetic damper 14 shown in FIG.

  The viscous damper 33 of the dynamic vibration absorber 30 is placed on the support plate 7 and has a cylindrical container 31 whose upper surface is open, a viscous body 32 accommodated in the container 31, and a bottom surface of the container 31 with a predetermined interval W. And a weight 4 immersed in the viscous body 32.

  The viscous damper 33 having the above configuration causes the weight 4 to be displaced in the horizontal direction due to the vibration of the bar spring 3, and causes shear resistance to the viscous body 32 existing in the gap between the lower surface of the weight 4 and the bottom surface of the container 31. Viscosity damping can be obtained. This shear resistance decreases as the gap between the lower surface of the weight 4 and the bottom surface of the container 31, that is, the viscous shear interval W increases, and increases as the viscous shear interval W decreases. For this reason, by adjusting the viscous shear interval W, the shear resistance can be easily adjusted to a predetermined magnitude, and the attenuation characteristic can be adjusted. As described above, the dynamic vibration absorber 30 using the viscous damper 33 can be easily adjusted at the time of construction in the same manner as the dynamic vibration absorber using the magnetic damper 14.

  The dynamic vibration absorber 30 can also be configured using the bar spring 21, the inner rod body 22, and the connecting portion 23 shown in FIG. 8 as a configuration for adjusting the spring characteristics and the damping characteristics.

  The Lorentz force of the magnetic damper 14 or the viscous shear resistance of the viscous damper 33 depends on the area of the conductive plate 4a attached to the lower surface of the weight 4 or the area of the lower surface of the weight 4, respectively. Therefore, in order to adjust the Lorentz force and viscous shear resistance to a predetermined range, the area of the conductive plate 4a or the area of the lower surface of the weight 4 is appropriately set in advance so that it can be adjusted by the adjustment by the adjusting means for the damping characteristic. It is necessary to select.

  Similarly, the Lorentz force of the magnetic damper 14 or the viscous shear resistance of the viscous damper 33 depends on the magnetic force of the permanent magnet 8 or the viscosity of the viscous body 32, respectively. Therefore, in order to adjust the Lorentz force and viscous shear resistance to a predetermined range, it is necessary to appropriately select the magnetic force and viscosity beforehand so that the Lorentz force and the viscous shear resistance can be adjusted by the adjustment by the above-described damping characteristic adjusting means.

  In the above embodiment, a dynamic vibration absorber having a single bar spring is exemplified. However, as shown in FIG. 13, a plurality of sets of bar springs 3, inner cylinders 5, outer cylinders 6 and the like are arranged. You may arrange.

It is sectional drawing which shows 1st Embodiment of the dynamic vibration damper using the magnetic damper concerning this invention. It is the A section enlarged view of FIG. It is sectional drawing which shows the other example of an inner cylinder. It is a figure for demonstrating the case where a spring characteristic is changed to the short cycle side, Comprising: (a) is sectional drawing, (b) is a partially expanded view of (a). It is a figure for demonstrating the case where a spring characteristic is changed to the long period side, Comprising: (a) is sectional drawing, (b) is a partially expanded view of (a). It is a figure for demonstrating the case where a damping characteristic is increased, (a) is sectional drawing, (b) is a partially expanded view of (a). It is a figure for demonstrating the case where an attenuation | damping characteristic is decreased, Comprising: (a) is sectional drawing, (b) is a partially expanded view of (a). It is sectional drawing which shows 2nd Embodiment of the dynamic vibration damper using the magnetic damper concerning this invention. It is the D section enlarged view of FIG. It is a figure for demonstrating the case where a spring characteristic is adjusted, Comprising: (a) is sectional drawing, (b) is a partially expanded view of (a). It is a figure for demonstrating the case where an attenuation | damping characteristic is adjusted, Comprising: (a) is sectional drawing, (b) is a partially expanded view of (a). It is sectional drawing which shows one Embodiment of the dynamic vibration damper using the viscous damper concerning this invention. It is a figure which shows the other example of the dynamic vibration damper concerning this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Dynamic vibration absorber 2 Frame 2a Hole 2b Female screw 3 Bar spring 3a Male screw 4 Weight 4a Conductive plate 5 Inner cylinder 5a Female screw 5b Male screw 6 Outer cylinder 6a Female screw 7 Support plate 8 Permanent magnet 9 Bar spring restraint part 9a Through-hole 10 Adjustment Nut 11 Lock nut 11a Female screw 12 Lock nut 12a Female screw 13 Lock nut 14 Magnetic damper 20 Dynamic vibration absorber 21 Bar spring 21a Through hole 21b Male screw 22 Inner rod body 22a Male screw 22b Large diameter portion 23 Connecting portion 23a Female screw 23b Female screw 30 Dynamic vibration absorber 31 Container 32 Viscous body 33 Viscous damper B Fixed position C Support point

Claims (7)

A dynamic vibration absorber that absorbs vibration applied to the object to be controlled by vibrating a bar spring having a weight attached to one end, and attenuates the vibration of the bar spring by a damper configured between the weight and the damper. ,
Frame,
A fixing portion for fixing a part of the other end side of the bar spring to the frame;
A part of the axis of the bar spring is in contact with the bar spring so as to restrict movement of the bar spring in a direction perpendicular to the axial direction of the bar spring, thereby forming a fulcrum when the bar spring vibrates. A fulcrum forming part to be
The damping force of the dynamic vibration absorber is adjusted by moving the rod spring in the axial direction of the rod spring with respect to the frame via the fixing portion, and expanding or reducing the distance between the weight and a predetermined position of the damper. A first adjustment unit that
A second adjustment unit that adjusts the spring characteristics of the dynamic vibration absorber by moving the contact position of the fulcrum forming portion with respect to the rod spring in the axial direction of the rod spring and expanding or contracting the distance from the fulcrum to the weight. And a dynamic vibration absorber. An inner cylinder screwed with the outer peripheral surface of the bar spring at the inner peripheral surface and screwed with the frame at the outer peripheral surface on one end side;
An outer cylinder that is threadedly engaged with the outer peripheral surface on the other end side of the inner cylindrical body at the inner peripheral surface on one end side, and is provided with a bar spring restraining portion that contacts the bar spring and forms the fulcrum on the other end side With body,
The bar spring is screwed to the inner peripheral surface of the inner cylinder so as to be movable in the axial direction of the bar spring,
The dynamic vibration absorber according to claim 1, wherein the outer cylinder body is screwed with an outer peripheral surface of the inner cylinder body so as to be movable in an axial direction of the bar spring.   The bar spring restraining portion is configured to be able to slide the bar spring in the axial direction of the bar spring while restricting the bar spring from moving in a direction perpendicular to the axial direction of the bar spring. The dynamic vibration absorber according to claim 2, wherein The bar spring is formed in a cylindrical shape having a through hole, and is screwed with the frame at the outer peripheral surface on the other end side,
The dynamic vibration absorber
An inner rod inserted into the through hole;
A large-diameter portion that is provided on the inner rod body and abuts on the inner peripheral surface of the bar spring to form the fulcrum;
A threaded engagement with each of the bar spring and the inner rod body, and a coupling portion for coupling the bar spring and the inner rod body;
The bar spring is screwed into the connecting portion so as to be movable in the axial direction of the bar spring,
2. The dynamic vibration absorber according to claim 1, wherein the inner rod body is screwed to the connecting portion so as to be movable in an axial direction of the bar spring.   The large diameter portion is slidably moved in the axial direction of the bar spring while restricting the bar spring from moving in a direction perpendicular to the axial direction of the bar spring. The dynamic vibration absorber according to claim 4, wherein the dynamic vibration absorber is abutted.   The damper includes either one of a conductor or a magnet attached to the weight, and one of the conductor or the magnet disposed at a predetermined interval from the conductor or the magnet. 6. The dynamic vibration absorber according to claim 1, wherein the dynamic vibration absorber is a magnetic damper configured.   The damper is composed of a container having an upper surface opened, a viscous body housed in the container, and a weight arranged at a predetermined interval from the bottom surface of the container and immersed in the viscous body. 6. The dynamic vibration absorber according to claim 1, wherein the dynamic vibration absorber is a damper.

Images