JP2010127455A - Base isolation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a base isolation system using balls with a one-step structure and ball grooves wherein a comparatively stable frictional coefficient can be obtained even if the frictional coefficient in a moving direction fluctuates. <P>SOLUTION: A base isolation component 1 includes the balls 6 which are fitted in the ball grooves 3 of an upper guide 2 and ball grooves 5 of a lower guide 4 and are movably arranged to slide or roll between the ball grooves. When the upper and lower ball grooves are projected from the perpendicular direction while the crossed angle θ of both ball grooves is set to be 90° or the crossed angle is differentiated, four sets of base isolation components are arranged between the upper and lower plates 22, 23 so that the base isolation components 1 having different mounting directions of the ball grooves in the horizontal direction are set up to be two or more, and it is controlled that any isolation component does not produce complete sliding only in the whole horizontal direction. In the base isolation components, ball grooves are arranged in a X-shape on the four corners of a square shape so as to be a point-symmetry each other against the center of the square shape for combining ball groove centers 2c, 3c. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to seismic isolation parts and seismic isolation devices for protecting articles such as computer servers, arts and crafts, and large buildings from earthquakes, and in particular, ball groove type immunity using balls and ball grooves. It relates to improvement of seismic devices.

  Conventionally, for example, in the slide guide type seismic isolation device shown in Patent Document 1, an upper slide guide and a lower slide guide are provided so that the upper slide guide is substantially perpendicular to the upper slide guide. Provide a slide part that can move along the upper slide guide and move along the lower guide between the guides, and move the upper and lower slide guides in the relative direction. As a seismic isolation component that moves horizontally.

  Place and fix these 4 seismic isolation parts so that the line connecting the center of the upper slide guide to the lower side of the upper plate is a square, and the line connecting the center of the lower slide guide to the upper side of the lower plate is a square The upper table and the lower table are relatively moved in the horizontal direction. Moreover, it arrange | positions in the cross shape with respect to the square side. In addition, what is arrange | positioned at X shape is also known. In addition, the slide portion is known to have a ball slide provided with a large number of balls or a slide surface. In such a slide guide type seismic isolation device, since the frictional force between the slide guides is substantially constant, the slide part is returned to the center (original position) by pulling it from both sides with a spring.

  However, it is necessary to attenuate the shaking by a brake or the like in addition to the restoring force against the shaking of the earthquake. In this case, since the frictional force is constant, an additional mechanism for applying friction must be provided.

  Therefore, in Patent Document 2, an upper guide portion provided with a ball groove provided linearly on the lower surface side, a lower guide portion provided with a ball groove provided linearly on the upper surface side, and a ball of the upper guide portion A ball and a ball groove type seismic isolation part that fits into the groove and the ball groove of the lower guide part and is slidable or rollable between both ball grooves. It was set to be deep and automatically returned. In addition, seismic isolation parts (Fig. 1) whose crossing angle when the horizontal axis of both ball grooves is viewed from the vertical direction is more than 0 ° and less than 90 ° are arranged at the four corners of the square, and the moving direction is the crossing angle. The bisector direction is assumed. By selecting this crossing angle, from pure rolling (crossing angle 0 °, friction coefficient 0.001 to 0.002) to complete slip (crossing angle 90 ° and moving direction is bisector) In the case of the ball groove direction, an arbitrary friction coefficient (for example, about 0.02 to 0.14) between 0.1 and 0.2) can be obtained (FIG. 3). Note that the friction coefficient when the crossing angle is 0 ° is the same as that in Patent Document 1, and the moving direction is the ball groove direction, which is pure rolling friction. Moreover, although the thing of 90 degrees of crossings is mentioned, there was no merit in the use in two steps. Further, the use in one stage is limited to the use in the uniaxial direction (paragraph 0017 in the cited document 2).

  Further, in Patent Document 3, the crossing angle when the horizontal axis of both ball grooves is viewed from the vertical direction is set to 0 ° or more and 90 ° or less, and two or more sets of seismic isolation parts having different crossing angles are placed at the four corners of the rectangle. (The line connecting the centers (centers) of the ball grooves is a square). Thereby, a wide range of arbitrary friction coefficients can be obtained by combining a plurality of seismic isolation parts having different crossing angles, that is, different friction coefficients.

JP 2001-349373 A JP 2006-183862 A JP 2006-158476 A

  However, Patent Documents 2 and 3 give a predetermined coefficient of friction to a ball that performs a sliding motion between intersecting ball grooves. The coefficient of friction depends on the crossing angle. Therefore, in order to obtain a predetermined coefficient of friction, it is necessary to move the ball in the direction of the bisector of the crossing angle. Further, in order to obtain an appropriate friction coefficient, the crossing angle must be set to about 30 ° to 40 ° smaller than 90 °. For example, if a crossing angle of 40 ° is set in one direction, the friction coefficient in the bisector direction of the crossing angle corresponds to 40 °. However, the 90 ° crossing angle of the bisector of the crossing angle is 90−40 = 50 °, and there is a difference in the friction coefficient in the two horizontal axis directions, so the seismic isolation performance (friction coefficient) depends on the direction. It will change. For this reason, in order to maintain an appropriate friction coefficient and to be able to move horizontally in the entire horizontal direction, the two structures are shifted by 90 ° from each other in two directions (X and Y directions), that is, seismic isolation parts. It was necessary to use a two-stage seismic isolation device with two layers.

  On the other hand, depending on the type of the thing to be loaded on the seismic isolation device, or in the seismic isolation device of 200 gal or less, it is not always necessary to use a highly accurate friction coefficient. Accordingly, an object of the present invention is to provide a single-stage seismic isolation device that can obtain a relatively stable friction coefficient even if the friction coefficient varies, for example, to about 0.08 to 0.12 depending on the moving direction. . Even in the case of Patent Document 1, the slide part needs two parts, that is, an upper slide guide, an upper slide that slides, and a lower slide that slides, and can be said to have a two-stage structure.

  In the present invention, the upper guide part provided with the ball groove provided linearly on the lower surface side, the lower guide part provided with the ball groove provided linearly on the upper surface side, and the ball groove of the upper guide part And a ball fitted to the ball groove of the lower guide part and slidable or rolling between the two ball grooves, and the ball groove has a maximum depth at the center. There are four or more sets of parts, and the upper guide part is arranged and fixed on the lower side of the upper plate so that the line connecting the centers of the ball grooves of the upper guide part is a square, and the lower guide is located on the upper side of the lower plate. When the projection is projected from the vertical direction of the upper and lower plates, the mounting direction of the ball groove is horizontal when the portion is fixed so that the line connecting the center of the ball groove of the lower guide portion is a square. Have two or more seismic isolation parts different from each other, By providing a seismic isolation device whose serial ball is so as not to be moved in the ball groove directions simultaneously, to solve the aforementioned problems.

  In other words, the ball and ball groove type seismic isolation parts are arranged in the same manner as in Patent Documents 2 and 3, so that the sliding direction is rolling and sliding in the bisector direction of the crossing angle. Become. However, if the direction of the ball grooves of all the sets is the same, the friction coefficient shown in FIG. 2 is maximized when the moving direction is the ball groove direction. In particular, when the crossing angle is 90 °, the slipping state is complete. In this case, it becomes sliding friction instead of rolling sliding friction, resulting in a very large friction coefficient. Therefore, in the present invention, since the direction of at least one pair of ball grooves is different, even if the movement direction of other balls is the ball groove direction, the direction of the balls is different, so that not only the maximum friction coefficient is obtained. The overall coefficient of friction is reduced. Thereby, even if a moving direction changes, the fluctuation | variation of a friction coefficient does not become large too much. In addition, when the crossing angle is 90 °, some seismic isolation parts are completely slipped and slipped. As for the friction coefficient at this time, since the friction coefficient is much smaller in the case of complete slip and rolling slip than 90 °, the increase in the overall friction coefficient is remarkably reduced.

  More preferably, the change in the friction coefficient is preferably small. Therefore, in the invention described in claim 2, the ball grooves are attached so that the seismic isolation parts are point objects with respect to the center of the quadrangle.

  That is, by making them point-symmetric with each other, the four sets of ball grooves are tilted inward or outward. As a result, there are two pairs in which the directions of the ball grooves coincide with each other, so that the friction coefficient in movement in the ball groove direction can be lowered. Further, in the case of asymmetrical, a force in the twisting direction is generated in the upper and lower tables, and the operation becomes unstable.

  The arrangement of the seismic isolation parts is preferably uniform. Therefore, although it may be arranged in a cross shape at the four corners as in the cited document, the moving distance is structurally the shortest in the ball groove direction and the longest in the bisector direction of the crossing angle. Therefore, when making the mounting table into a square shape that matches the square arrangement, it is preferable from the viewpoint of handling, strength, and size that the stroke is long in the front-rear and left-right directions. Therefore, in the invention according to claim 3, the seismic isolation component is a seismic isolation device arranged in an X shape with respect to the square side.

  In order to change the direction of the ball groove, the crossing angle may be changed. Therefore, in the invention according to claim 4, the seismic isolation parts are two or more seismic isolation parts having different crossing angles. For example, a crossing angle of 40 ° and a crossing angle of 60 ° are alternately arranged in an X shape at four corners of a quadrangle. The crossing angle of 40 ° has the highest friction coefficient because the ball moves along the ball groove when the upper and lower plates move relative to each other in the 40 ° direction. At this time, the one having an intersection angle of 60 ° has a low coefficient of friction because the ball does not move along the ball groove when the upper and lower plates move relative to each other in the 40 ° direction. Therefore, the overall friction coefficient can be lowered and variation can be reduced.

  The maximum stroke of the seismic isolation component is the bisector direction with the smaller intersection angle of the ball grooves of the seismic isolation component. Moreover, the one where an intersection angle is small becomes long. For this reason, when the ball groove length is the same, when the angle is 40 ° and 60 °, 60 ° is shorter, so the entire stroke is 60 °. On the other hand, if the perpendicular direction is 60 °, the stroke becomes 90 ° -60 ° = 30 ° and the stroke becomes long. However, if it is 40 °, the stroke becomes 90 ° −40 ° = 50 °, so the stroke becomes effective. Cannot be used.

  Therefore, in the invention according to claim 5, the crossing angle of the seismic isolation parts is in a range of 90 ° ± 6 ° so that the direction in which all the balls and the ball grooves are only completely slipped does not occur. Seismic isolation device.

  That is, since the crossing angles are 90 ° and near 90 °, the strokes in the bisector direction are almost the same. Moreover, since the crossing angles are made different within a range of 12 ° in width, the directions of the ball grooves are not all the same. If the width of the crossing angle is small, all the balls may move in the direction of the ball groove due to a mounting error of the ball groove and the like, and there is a risk of complete slipping. The angle difference between the ball grooves is preferably about 6 °. As described above, when the crossing angle is in the vicinity of 90 °, some of the seismic isolation parts are changed from a complete slip to a rolling slip. Therefore, the friction coefficient of the complete slip and the rolling slip is much smaller than 90 °. The increase in the overall friction coefficient is remarkably reduced, and the effect of the present invention is great.

  In the above-described method, the crossing angle is varied, but it is also possible to reduce the number of matching ball grooves by simultaneously changing the mounting angle. Therefore, in the invention described in claim 6, the seismic isolation component is two or more seismic isolation components having different crossing angles, and the seismic isolation device is different in two or more mounting directions to the upper and lower plates.

  Furthermore, in the invention of claim 7, only the mounting direction is changed, the seismic isolation parts are seismic isolation parts having the same crossing angle, and two or more seismic isolation parts have different mounting directions on the upper and lower plates. Provide a seismic device. In this case, for example, seismic isolation parts having a crossing angle of 93 ° may be arranged at four corners while being rotated by 90 °. Further, as in the case of claim 5 described above, in order to achieve uniform stroke, in the invention according to claim 8, the crossing angle of the seismic isolation device is 90 °, and all the balls and the ball grooves The seismic isolation device is designed so that the direction in which only slips completely does not occur. In order not to be completely slippery, they can be placed tilted inside each other.

  Increasing the tilt angle of seismic isolation parts reduces the stroke. If the amount is too small, there is a risk of complete slippage in the seismic isolation parts due to mounting errors of the ball groove. Therefore, in the invention according to claim 9, the seismic isolation parts are pointed to each other with respect to the center of the quadrangle, arranged in an X shape with respect to the side of the quadrangle, and the seismic isolation part The seismic isolation device in which the inclination of the ball groove with respect to the square side is 45 ° ± 0 ° and 6 ° or less.

  According to the seismic isolation device of the present invention, the direction of at least one set of ball grooves of the ball and ball groove type seismic isolation parts is arranged between the upper and lower plates, and the coefficient of friction varies even if the moving direction changes. As a result, it was decided to provide a simple one-stage seismic isolation device. In addition, it is a simple seismic isolation component consisting of a single upper and lower ball groove and ball. The ball corresponding to the slide member that slides on the slide guide is simple in structure, easy to handle, and low in height. It became a thing.

  In the invention according to claim 2, the ball grooves are attached so that the seismic isolation parts are pointed to each other with respect to the center of the quadrangle, the friction coefficient in the ball groove direction is lowered, and the force in the torsion direction is Since the presser and the operation are stable, the structure is simple and the rotation stopper and the like may be simple.

  Furthermore, in the invention according to claim 3, since the seismic isolation parts are arranged in an X shape with respect to the sides of the rectangle, and the strokes are made longer and longer in the front-rear and left-right directions, the seismic isolation device is installed and handled. Became easier.

  Further, in the invention according to claim 4, by making the seismic isolation parts two or more seismic isolation parts having mutually different crossing angles, a single-stage seismic isolation device can be obtained. Furthermore, in the invention according to claim 5, since the crossing angle of the seismic isolation parts is in the range of 90 ° ± 6 °, the stroke difference in the left and right and front and rear directions is small, and the size is appropriate for the ball groove. It can be a one-stage seismic isolation device. Furthermore, in invention of Claim 6, a 1 step | paragraph seismic isolation apparatus is provided by changing a crossing angle and a mounting angle.

  Furthermore, in the invention described in claim 7, it is possible to provide a one-stage seismic isolation device with the same crossing angle and different mounting directions only. In the invention according to claim 8, since the crossing angle of the seismic isolation device is 90 °, the difference in frictional force and stroke depending on the seismic isolation direction is reduced, and the structure is simple and easy to use. Became to provide. Furthermore, in the invention according to claim 9, the seismic isolation device is arranged in a point object, in an X shape, and has an inclination with respect to the square side of the ball groove of the seismic isolation component exceeding 45 ° ± 0 ° and 6 ° or less. As a result, a one-stage seismic isolation device with a large stroke and a large variation in the coefficient of friction was provided.

  Although the embodiment of the present invention overlaps with the descriptions in Patent Documents 1 and 2 described above, first, the seismic isolation component will be described with reference to the drawings. FIG. 1 is a plan view in the case of the crossing angle θ according to the seismic isolation component of the present invention, and FIG. As shown in FIG. 1, the seismic isolation component 1 of the present invention is provided with an upper guide portion 2 having a ball groove 4 provided linearly on the lower surface 2a side (indicated by a dotted line). A lower guide portion 3 having a ball groove 5 linearly provided on the upper surface 3 b side is fixed to the base 13. A guide (not shown) is provided, and the upper guide portion 2 and the lower guide portion 3 are regulated so as to always have an intersection angle θ. Between the upper and lower ball grooves 4 and 5, there is provided a ball 6 which is fitted in both ball grooves and is slidable or rollable between both ball grooves. The vertical cross section of the ball groove (not shown) is such that the bottom is deepest at the centers 2c and 3c, and the ball is stable at the positions of the center positions 2c and 3c (4c and 5c) of the respective ball grooves.

  In such a configuration, when the upper guide portion 2 is moved relative to the lower guide portion 3, the crossing angle θ is always regulated to be constant, so that the ball 6 is placed at the center 3c of the lower ball groove 5 as shown in FIG. In some cases, the upper guide portion can move only in the direction of the upper ball groove 4 and can move only in the range indicated by the arrow A. Similarly, when the ball 6 is in the upper right end 5r as viewed in the lower ball groove 5, the range similarly indicated by the arrow B, and when the ball is in the lower left end 5s as viewed in the lower ball groove, the same applies. Since only the range indicated by the arrow C can move, the upper guide portion 2 eventually moves within the range surrounded by the two-dot chain line 10. That is, the lower guide portion 3 and the upper guide portion 2 can be relatively horizontally moved within a range surrounded by a two-dot chain line 10. The longest moving distance is the maximum moving distance L in the bisector direction of the intersection angle, and the minimum moving distance S in the perpendicular direction. When θ = 90 °, L = S. Further, in the figure, the direction of 45 ° obliquely moves the length of the ball groove.

  The friction coefficient of the seismic isolation component 1 will be described. For example, the friction coefficient at the time of movement of the upper guide portion 2 indicated by an arrow A is rolling and sliding friction between the ball 6 and the upper ball groove 4 and sliding friction between the ball and the lower ball groove 5. Slip is 0 when the ball 6 moves along the ball grooves 4 and 5, and becomes maximum when the ball rotates at right angles to the ball grooves, and the slip decreases as the crossing angle θ of the ball grooves decreases. Therefore, the friction coefficient for each crossing angle θ was measured. The result is shown in FIG. The ball material is SUJ2 (bearing steel), the upper and lower guides are the same, the material is tempered material of S45C, and the ball groove has a Gothic arch cross section with a radius of 52% of the ball diameter and an intersecting angle of 50 °. The groove depth was about 40% of the ball diameter. In addition, four sets of seismic isolation parts were equally placed at the four corners for stabilization.

  As shown in FIG. 3, when the crossing angle θ = 90 degrees, the friction coefficient due to slip is 0.15, and when the crossing angle θ = 0, the conventional ball grooves are arranged in parallel and the rolling coefficient is 0, and the friction coefficient is 0. It is about 0.001 to 0.002. When the crossing angle θ = 30 °, the friction coefficient is 0.05, θ = 45 ° is 0.07, θ = 60 ° is 0.1, θ = 75 ° is 0.12, and the crossing angle is 90 °. The coefficient of friction is approximately equal to the value obtained by connecting the angle and the crossing angle of 0 degrees with a straight line F. Thus, it can be seen that the friction coefficient of the ball groove and ball type seismic isolation part changes according to the crossing angle, that is, the desired frictional coefficient can be easily obtained by changing the crossing angle. In addition, when a higher friction coefficient is required, the friction coefficient at an intersection angle of 90 degrees may be increased by selecting the above-described surface treatment or material.

  Next, the difference in moving direction will be described in the case of the intersection angle θ = 90 ° of the present invention. In this case, when moving in the ball groove direction, as described above, the friction coefficient is about 0.15. On the other hand, when moving in a direction other than the ball groove, since a rolling element is inserted instead of complete slip, the friction coefficient is greatly reduced to about 0.09 to 0.1. Furthermore, when moving in the direction of the bisector of the intersecting angle, the friction coefficient is about 0.08.

  Next, an embodiment of the seismic isolation device of the present invention using the seismic isolation component 1 will be described with reference to the drawings. This is a one-stage seismic isolation device in which four sets of seismic isolation components with a crossing angle of 90 ° are arranged in the shape of a dot, in an X shape, and the inclination of the seismic isolation components with respect to the square sides of the ball groove is different. 4A is a plan view of the seismic isolation device when the ball is in a neutral position, FIG. 4B is a front view, FIG. 5C is a perspective view, and FIG. 5A is a view taken along line AA in FIG. (Upper plate), (b) is a view taken along arrow B-B (lower plate), FIG. 6 (a) is a plan view of the seismic isolation device when the upper plate moves sideways (right), (b) 7A is a perspective view, FIG. 7A is a plan view of the seismic isolation device when the upper plate is moved vertically (upward), FIG. 7B is a perspective view, and FIG. The top view of the seismic isolation apparatus when moving to the direction, (b) is a perspective view.

  As shown in FIGS. 4 and 5, the seismic isolation device 21 of this embodiment includes an upper plate 22 on which a seismic isolation server and artwork are placed, and a lower plate 23 that is fixedly attached to a base such as a fixed floor. In addition, four seismic isolation parts 1 are provided between the upper plate and the lower plate at positions corresponding to the four corners of the quadrilateral. In addition, a code | symbol abbreviate | omits part or all about the same components. The upper and lower plates 22 and 23 are each composed of two plates and are integrally connected by upper and lower plate connecting rods 24 and 25, respectively.

  As shown in FIG. 5A, the upper guide portions 2 are fixed to the four corners of the lower surface of the upper plate 22 with a large number of bolts 31 with the ball grooves 4 facing downward. Further, as shown in FIG. 5B, the lower guide portions 3 are respectively fixed by bolts 31 with the ball grooves 5 facing upward at the four corners of the upper surface of the lower plate 23. The upper guide portion 2 and the lower guide portion 3 are attached so that the crossing angle of the respective ball grooves 4 and 5 is 90 °. Balls (steel balls) 6 are held between the ball grooves 4 and 5 so as to be able to slide and rotate, and four sets of seismic isolation parts 1 are installed between the upper plate 22 and the lower plate 23. Lines connecting the centers 4c and 5c of the upper and lower ball grooves 4 and 5 are made to be rectangular Kk and Ss, and are parallel to the sides of the rectangular upper and lower plates. The ball grooves 4 of the upper guide portion 2 are formed in a Katakana-shaped C shape, and the ball grooves 5 of the lower guide portion 3 are formed in a reverse-C shape of Katakana. As shown by the dotted line in FIG. 4A, when projected from the vertical direction, the upper and lower ball grooves 4 and 5 (upper and lower guide portions 2 and 3) form an X-shape with respect to the square side. It is arranged to become.

  As shown in FIG. 5B, the angle of the lower ball groove 5 is inclined 48 ° (45 ° + 3 °) outward with respect to the vertical side S of the line connecting the centers 5c of the lower ball grooves. Further, as shown in FIG. 5 (b), the upper ball groove 4 corresponds to the lower ball groove 5 so that the crossing angle is 90 °, and is located beside the line connecting the centers 4c of the upper and lower ball grooves. Similarly, it falls to the outside by 48 ° (45 ° + 3 °) with respect to the side k. It is point symmetric with respect to the center of the quadrangular lines Ss and Kk connecting the centers of the upper and lower ball grooves, and further symmetric with respect to the central axis. A guide 28 is provided around the ball 6 so as to be fitted simultaneously with the side portions of the upper and lower guide portions so as to make the crossing angle of the ball grooves constant, and to prevent the upper plate from floating with respect to the lower plate. It has been. Further, a buffer rubber 33 is fixed on the upper surface of the lower plate 23 and is in contact with an X-axis stopper 29 and a Y-axis stopper 30 provided on the lower surface of the upper plate 22 so that the movement range of the upper and lower plates can be reduced. You can limit it. A hole 32 is formed in the center of the lower plate, and a wiring guide (wall) 34 for protecting the wiring is provided.

  In the seismic isolation device 21 having such a configuration, a case where the upper plate 22 is moved in the lateral (right) direction as viewed in FIG. 4 will be described. When the upper plate 22 receives a force in the left-right direction, as shown in FIG. 7, the bisector direction with a crossing angle of 90 °, that is, the left-right direction is easy to move because the friction is small. Therefore, the upper plate 22 moves in the left-right direction.

  Next, the case where the upper plate 22 is moved in the upward (vertical or backward) direction as viewed in FIG. 4 will be described. When the upper plate 22 receives a force in the vertical direction, as shown in FIG. 7, it is easy to move because the friction is small in the bisector direction of 90 ° and the vertical direction as in the right direction. Therefore, the upper plate 22 moves upward with respect to the lower plate 23. The inclination of the ball grooves 4 and 5 (vertical guides 2 and 3) with respect to the left and right and vertical (vertical or longitudinal) directions is ± 3 °, and is hardly affected.

  In the seismic isolation device 21, the left and right and front and rear movements are combined, and the upper and lower plates 22 and 23 move relative to each other in all horizontal directions. However, if the mounting angles of the seismic isolation parts 1 are all the same, if a force is applied in the oblique 45 ° direction, which is the ball groove direction, the ball 6 and one of the ball grooves 4 and 5 are completely slipped, increasing the frictional resistance. To do. For this reason, the left and right and front and rear fine movements are repeatedly moved relative to each other in the 45 ° direction, and the operation becomes jerky and fine vibrations are applied, so that the original seismic isolation performance cannot be ensured. On the other hand, as shown in FIG. 8, in the present embodiment, the mounting angle is point-symmetric with respect to the central axis, and the outer side is slant 48 °, and the direction of the ball moving in the ball grooves 4 and 5 is 2 The pairs will be the same, but the four sets will not be the same. Therefore, for example, when a force in the direction of 45 ° is applied, the angle does not coincide with the angle of the ball groove, so that all the balls do not slide completely but roll, so the coefficient of friction is low and smoothly in the 45 ° direction. It will move.

  When force is applied in the same direction as one ball groove, the other ball groove does not move in the same direction, so the two balls are completely slipped, but the remaining two balls are rolling and sliding. The coefficient is low. Therefore, the overall coefficient of friction is an intermediate coefficient between perfect slip and rolling slip. This value is sufficiently low for complete slipping, so it will move smoothly. In the case of the inclination in the present embodiment, the variation due to the direction of the friction coefficient is about 0.08 to 0.12 (specific angle at the ball groove), and the variation is small except for the specific angle, and the friction coefficient is also small. It became. As described above, according to the present embodiment, there is a variation in the coefficient of friction depending on the direction without greatly reducing the stroke, but there is no state of complete slipping. Get performance.

  Next, another embodiment of the present invention will be described. FIG. 9 is a schematic view showing another embodiment of the present invention, in which the lower plate 23 'and the lower ball groove 5 are shown by solid lines, and the upper ball groove 4 is shown by dotted lines. FIG. 13 is exaggerated. In this example, the seismic isolation component 1 having an intersection angle of 87 ° is attached by being rotated every 90 °. The same components as those described above are denoted by the same reference numerals and a part of the description is omitted. As shown in FIG. 9, in the same manner as in the above-described embodiment, the mounting of the ball groove 4 of the upper guide portion 2 is in the shape of a Katakana character, and the ball groove 5 of the lower guide portion 3 is in the opposite shape of the Katakana character. When projected in a letter shape from the vertical direction, the upper and lower ball grooves 4 and 5 are arranged in an X shape with respect to the square side. Further, in the projection state from the vertical direction, the bisector direction of the ball groove and the quadrangular side are arranged so as to coincide with each other.

  As shown in FIG. 9, the crossing angle of the upper left and lower right ball grooves is 93 ° on the upper side, and the direction of the ball grooves is inclined 43.5 ° on the upper side with respect to the rectangular lateral side s. The crossing angle of the upper right and lower left ball grooves is 87 ° on the upper side, and the direction of the ball grooves is inclined 46.5 ° on the upper side with respect to the rectangular lateral side s. It is point-symmetric with respect to the center of the line Ss that connects the centers of the upper and lower ball grooves.

  In the seismic isolation device 21 ′ having such a configuration, when the upper plate (not shown) is moved in the left-right direction or the up-down direction as viewed in FIG. 9, the bisector direction of the crossing angle is substantially the same in both the up-down direction and the left-right direction. It is easy to move because the friction is small. Therefore, as described above, the upper plate can move left and right or up and down.

  Next, when a force is applied in the oblique 45 ° direction, the ball groove directions are 43.5 ° and 46.5 °, respectively, which are 1.5 ° different from 45 °. For this reason, the ball 6 and the ball grooves 4 and 5 are rolling and sliding. Since it is not completely slipping, the coefficient of friction is low and it moves smoothly in the 45 ° direction. When a force is applied in an oblique direction of 43.5 °, the upper left and the lower right are completely slipped, but the upper right and the lower left are different by 3 °, resulting in a rolling slip. The same applies to the 46.5 ° direction. Therefore, even if a force is applied in the direction of a set of ball grooves, all the balls do not slide completely, so the friction coefficient is low and the balls move smoothly. Thus, even if the crossing angle is the same, the mounting direction is changed, or the crossing angle is changed and combined, a stable seismic isolation performance sufficient for practical use can be obtained while securing the stroke.

  The depth of the bottom of the ball groove gradually increases from both ends, and the depth of the bottom of the center is the largest, but the longitudinal section along the ball groove at the bottom of the ball groove is similar to the conventional one, A straight line such as a V-shape, a curve such as a U-shape, an ellipse, or a circle is used. The upper and lower grooves preferably have the same cross-sectional shape. The cross-section of the ball groove is a cross section in which the ball such as a Gothic arch shape, V-groove shape, U-groove, U-groove, or the like where the ball contacts at two or more points rolls and rotates in directions other than the ball groove direction for stable operation. However, in the present embodiment, since slip is prevented from occurring, an arc cross section larger than the ball diameter that rotates in a direction other than the ball groove direction may be used to make a single point contact. Good.

It is a top view of the seismic isolation component concerning this invention. It is operation | movement explanatory drawing of the seismic isolation part concerning this invention. The result of having measured the friction coefficient with respect to each crossing angle (theta) of the seismic isolation part concerning this invention is shown, a horizontal axis shows crossing angle (theta), and a vertical axis | shaft shows friction coefficient (micro | micron | mu). BRIEF DESCRIPTION OF THE DRAWINGS (a) of the seismic isolation apparatus which shows embodiment of this invention is a top view at the time of a ball | bowl neutral position, (b) Front view, (c) is a perspective view. (A) is an AA arrow line view of FIG.4 (b), (b) is a BB line arrow line view. (A) of the seismic isolation apparatus which shows embodiment of this invention is a top view when an upper guide part moves to the side (right) side, (b) is a perspective view. (A) of the seismic isolation apparatus which shows embodiment of this invention is a top view when an upper guide part moves to the vertical (upward) direction, (b) is a perspective view. (A) of the seismic isolation apparatus which shows embodiment of this invention is a top view when an upper guide part moves diagonally rightward, (b) is a perspective view. It is a schematic plan view of the seismic isolation apparatus which shows other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Seismic isolation part 2 Upper guide part 3 Lower guide part 4 Ball groove of upper guide part 5 Ball groove of lower guide part 4c, 5c Center (part)
6 Ball 21, 21 'Seismic isolation device 22 Upper plate 23 Lower plate Square Ss, Kk
θ Crossing angle

Claims (9)

  An upper guide part provided with a ball groove linearly provided on the lower surface side, a lower guide part provided with a ball groove provided linearly on the upper surface side, the ball groove of the upper guide part and the lower guide part Four or more sets of seismic isolation parts that have a maximum depth at the center, the ball groove being fitted in the ball groove and slidable or rolling between the two ball grooves. The upper guide portion is disposed and fixed on the lower side of the upper plate so that a line connecting the centers of the ball grooves of the upper guide portion is a square, and the lower guide portion is disposed on the upper side of the lower plate. When the ball groove is projected from the vertical direction of the upper and lower plates, two or more mounting directions of the ball groove are different in the horizontal direction. Having the seismic isolation parts, all the balls are simultaneously Seismic isolation device characterized in that it is so as not to move to the serial ball groove direction.   2. The seismic isolation device according to claim 1, wherein the ball isolation grooves are attached to the seismic isolation parts so as to be point targets with respect to the center of the quadrangle.   The seismic isolation device according to claim 2, wherein the seismic isolation component is arranged in an X shape with respect to the square side.   The seismic isolation device according to claim 1, wherein the seismic isolation component is two or more seismic isolation components having different crossing angles.   5. The crossing angle of the seismic isolation component according to claim 4 is in a range of 90 ° ± 6 ° so that a direction in which all the balls and the ball groove are only completely slipped does not occur. The seismic isolation device according to claim 4.   The seismic isolation device according to any one of claims 1 to 5, wherein the seismic isolation components are two or more seismic isolation components having different crossing angles, and two or more attachment directions to the upper and lower plates are different.   The seismic isolation device according to claim 1, 2 or 3, wherein the seismic isolation components are seismic isolation components having the same crossing angle, and two or more seismic isolation components have different mounting directions to the upper and lower plates. .   The crossing angle of the seismic isolation device according to claim 7 is 90 °, and a direction in which all the balls and the ball grooves are only completely slipped is not generated. The seismic isolation device described.   The seismic isolation parts are pointed to each other with respect to the center of the quadrangle, arranged in an X shape with respect to the side of the quadrangle, and the inclination of the ball groove of the seismic isolation part with respect to the side of the quadrangle is 45. The seismic isolation device according to claim 8, wherein the seismic isolation device is more than ±± 0 ° and not more than 6 °.

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