JP2004197551A - Spacer for anchor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spacer for an anchor causing little eccentricity when inserted in a drilled hole by maintaining the uniform radial arrangement of space holding pieces to the outer diameter change of the anchor such as a lock bolt. <P>SOLUTION: This spacer 3 for the anchor comprises four space holding pieces 31c, 31d, etc., and an approximately cylindrical grip part 11 and a cylindrical part 32 provided on both sides. The cylindrical part 32 is placed in a loosely fitted state to the anchor and longitudinally displaced by the diameter reduced deformation of the respective space holding pieces 31c, 31d, etc. when inserted. The parts which intersect the grip part 11, of two space holding pieces 31d (31a) close to an opening side end part 13 of the grip part 11 fitted to the anchor are respectively located inward in the circumferential direction of the grip part 11 in relation to the same parts of the space holding pieces 31c (31b) placed in the opposed relation with the axis of the grip part 11 held in between. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to an anchor spacer for holding an anchor at an anchor hole position in an anchor hole when an anchor such as a lock bolt is installed on the ground.

  Conventionally, various anchors such as rock bolts and ground anchors have been frequently used as means for stabilizing the ground. These anchors are fixed to the ground by filling an appropriate grout material around the anchors in a state where the anchors are inserted into anchor holes (drilling holes). In this fixing operation, it is important to properly secure the covering thickness of the grout material. For this reason, various shapes of spacers (also referred to as centerizers) for positioning the anchor at the center of the drilling hole, that is, at the hole center. Generally used, a plurality of anchors are attached to the insertion portion of the anchor at predetermined intervals.

  As conventional examples of such a spacer, those described in Patent Documents 1 to 3 below are known. The basic configuration is such that a part of the peripheral wall is cut off, and a substantially cylindrical grip portion capable of expanding and contracting in and out in the radial direction, and a plurality of grip portions provided at substantially equal intervals in the circumferential direction and bulging radially outward. Consisting of a spacing piece. And when these spacers are fitted with their cylindrical portions at appropriate positions in the longitudinal direction of the anchor, a plurality of spacing pieces that protrude radially from the outer peripheral surface of the anchor respectively contact the inner surface of the excavation hole, The anchor is held at the center of the borehole.

JP-B-64-537 (page 1, column 2, line 15-page 2, column 4, line 12, FIG. 1 and FIG. 2) Japanese Utility Model Publication No. 6-7120 (Page 2, column 4, line 30-page 3, column 5, line 6, FIGS. 1 and 2) JP-A-4-189917 (page 2, upper right column, second line-same lower left column, line 14, FIG. 1 and FIG. 3)

  In the case of the lock bolt which is a main object of the spacer, deformed steel bars for reinforced concrete such as bamboo bar steel bars and screw bar bars are used for reasons such as economy and availability. These deformed steel bars are applied in an appropriate state other than cutting the length, for example, by threading the ends, or without any special processing. As the lock bolt, an appropriate one is selected from deformed steel bars of various shapes and specifications according to the use conditions and the like. By the way, details of dimensions such as rib outer diameter and node outer diameter of the above deformed steel bars vary considerably among manufacturers even if the names indicating the standards of the outer diameters are the same. Furthermore, even if the cross-section is out of a perfect circle such as an elliptical shape, the shape and size of the deformed steel bar are various even if the same name is used. Furthermore, since the difference in the anchoring force of the grout material occurs due to the properties of the target ground, there are many cases where the drilling diameter is different even when the same anchor is used, and in consideration of this, the inner diameter of the grip portion is the same. It is also necessary to have spacers with different protrusion amounts of the spacing members.

  However, it is uneconomical to prepare a large number of spacers that match the respective names and drilling diameters for each manufacturer of deformed steel bars, which leads to increased manufacturing and storage costs. For this reason, in the conventional spacers described in Patent Documents 1 and 3, a material that can be appropriately deformed is used, and the inner diameter of the substantially cylindrical grip portion is assumed to be reduced at the time of mounting. Is generally set large so that it can correspond to several types of names. Also, with regard to the amount of protrusion of the spacing member, the diameter is reduced by plastic deformation in advance as in the case of the gripping part, or set to a large value on the premise of deformation at the time of insertion into a drill hole. Is the fact.

  Further, in the above-described conventional spacer, the radially deformable substantially cylindrical grip portion has a part of the peripheral wall divided in the longitudinal direction, and an appropriate interval is formed between the divided peripheral wall side ends. I have. The plurality of spacing pieces that bulge outward in the direction perpendicular to the circumference of the grip portion, that is, along the longitudinal direction of the anchor and outward in the radial direction, hold each spacing based on the non-attached state. The pieces are disposed in parallel with each other at positions that are substantially equally spaced on the circumference with respect to the grip portion. Taking the spacer described in Patent Literature 1 as an example, as shown in FIGS. 25 and 26, the four interval holding pieces 5A, 5B, 5C, and 5D are almost 90 degrees in the non-attached state with respect to the grip portion 6. It is made to be an interval.

  However, with the above-described setting based on the non-mounted state, in the mounted state of the spacer, as shown in FIG. 27, the grip portion 6 is reduced in diameter according to the outer diameter of the anchor A to be applied. The spacing between adjacent spacing pieces 5A to 5D changes, and the uniform arrangement is broken. In this case, first, a difference occurs in the distance from the axis of the anchor A to each of the bulging portions of the spacing members 5A to 5D. In addition, the spacing members 5A and 5D provided near the opening-side end of the gripper 6 are most susceptible to the diameter reduction deformation. It is inevitable that the direction of the facing surface of the bulging portion to be in contact changes. This appears as a difference in supporting force among the spacing members 5A to 5D. In particular, the tendency is remarkable in the case where the anchor is attached to the anchor of the lower limit of application where the degree of diameter reduction deformation is large. A similar phenomenon also occurs in a type in which the diameter is increased as in the spacer described in Patent Document 2. As described above, the gap holding pieces do not abut on the inner surface of the drill hole in a uniform radial arrangement due to the expansion and contraction deformation of the gripping portion, so that the filling of the grout material between the anchor and the drill hole becomes poor. There is a problem in that the displacement of the axis center, which is likely to occur, tends to occur.

  By the way, in many grounds, gravel, earth and sand, bedrock, etc. are mixed and the ground is not uniform. For this reason, the straightness of the excavation hole is reduced, and a distorted portion is formed over the entire length without forming a true circular cross section. Under such circumstances, the spacers, which do not cause a large resistance at the time of insertion into the drilling hole and have to hold the anchor at the center position after insertion, can follow the wall surface state of the drilling hole. A moderate elastic deformation capacity is desired.

  The spacer described in Patent Literature 1 has a configuration in which a grip portion is opened, but is premised on insertion from an anchor end portion due to its shape. That is, as is apparent from the drawing, the side edges of the gripper peripheral wall in the opening remain punched, and the width of the opening relative to the outer diameter of the anchor is particularly narrow. is there. Furthermore, since the insertion is performed from the anchor end, the inner diameter of both gripping portions is set to be slightly larger than the outer diameter of the anchor so that the gripper can be smoothly moved to a predetermined position in the longitudinal direction. Therefore, for fixing to the anchor, after shifting the spacer from the end to the predetermined position, the inner diameter of the grip portion is reduced by squeezing the bulging portion of each spacing piece, and the grip portion is tied with an appropriate binding wire. There is a need.

  When the grips at both ends are fixed in this way, each spacer is restrained at both ends by the grips integrated with the spacers, so that the spacer is formed of an elastic material such as a spring steel plate. In such a case, the elastic deformation capability is greatly suppressed. For this reason, at the time of insertion into an excavation hole, each spacing piece cannot smoothly elastically deform according to the state of the inner surface of the hole wall when passing through an elliptical portion of the hole, and a large resistance is generated. Occurs. Therefore, in this case, a decrease in insertability is inevitable. Furthermore, the four spacing pieces equally arranged in the circumferential direction in the non-attached state come out of the uniform arrangement as the diameter of the grip portion in the attached state is reduced. However, since each of the spacing pieces is constrained by the gripping portions at both ends, the abutment portion, which is the top, cannot follow the inner surface of the hole wall and cannot be deformed in the circumferential direction. This leads to a decrease in insertion performance and a cause of eccentricity. On the other hand, when the spacer is formed of an inelastic material, when applied to a drilling hole with poor straightness or roundness, the spacer that has been plastically deformed during insertion does not return to the original state, and the anchor is placed in the hole center. There is a problem that it cannot be located.

  Next, the spacer described in Patent Literature 2 differs from that of Patent Literature 1 in that the spacer is attached to the anchor from the side. In this case, the spacer is formed of an elastic material such as a spring steel plate, and is fixed to the anchor by the tightening force of the grip portion. Each of the spacing pieces protrudes radially outward at one end of the substantially cylindrical grip. Since these are integrally formed, the base portion of the spacing member, that is, a portion near the grip portion is formed in a curved shape under the influence of the cylindrical shape of the grip portion. For this reason, in this spacer, elastic deformation of the entire spacing member is suppressed, and substantially only a portion near the free end side is a deformable region. Therefore, at the time of insertion, the tip of the spacing member may be caught on the inner wall surface of the excavation hole or the inner wall surface may be shaved, so that the insertability of the spacer is not necessarily good. If such a bite occurs, the anchor cannot be positioned at the hole center. For example, the spacer still has a problem to be solved in the same manner as the above-described conventional example.

  The present invention has been made in view of these problems of the related art, and maintains a uniform radial arrangement of the spacing members with respect to a change in the outer diameter of the anchor. It is an object of the present invention to provide a spacer which is hardly generated and an anchor spacer which is hardly shifted and has improved insertability into a drill hole.

  In order to solve the above problem, in claim 1 of the present invention, a part of the peripheral wall is formed in a substantially cylindrical shape that opens along the axial direction, and the opening side ends thereof can be deformed radially inward and outward. A grip portion for receiving and gripping the anchor inside, and at least an intermediate portion at one end side integrally with the grip portion extend along the longitudinal direction of the anchor at substantially equal intervals in the circumferential direction and radially outward. An anchor spacer including at least three spacing holding pieces that swell and hold the swelling portion against a wall surface of a drilled hole to hold the anchor and the wall surface at a predetermined interval. Two of the bulging portions are arranged at positions closer to the opening-side end in the circumferential direction with respect to the gripping portion, and the intersection with the gripping portion is located more inward in the circumferential direction than the bulging portion. It is characterized by:

  According to the above configuration, the two spacing members disposed near the opening-side end, which are susceptible to the effect when the gripping portion expands or contracts in diameter, are anchored so as to abut against the inner surface of the hole. The bulging portion arranged along the longitudinal direction of the cross section does not intersect the gripping portion on an extension line thereof, but intersects at the base portion side at a position more inward in the circumferential direction than the bulging portion. That is, by interlocking the grip portion and the bulging portion of the spacing member by clearly separating the bulging portion from the bulging portion by, for example, inclining the base side portion of the spacing member with respect to the longitudinal direction of the anchor. be able to. As a result, in the two interval holding pieces disposed near the opening-side end, the deformation of the gripping portion is reduced at the base-side portion, and the influence on the bulging portion is reduced. Therefore, in such a spacer, the arrangement state of all the spacing members does not change so much even after the mounting, and always abuts substantially evenly on the inner surface of the drilled hole. Can be securely held at the center of the hole.

  The spacer according to claim 2 is characterized in that, in the above configuration, the side opposite to the gripping portion of the spacing member is formed as a free end. That is, since one end side of each spacing member is not restrained, when the bulging portion comes into contact with the inner surface of the drilled hole at the time of insertion into the drilled hole, they are moved in the longitudinal direction by elastic deformation or plastic deformation to reduce the diameter. I do. For this reason, even if the bulging portion of the spacing member is larger than the hole diameter, it can be smoothly inserted.

  According to a third aspect of the present invention, the folded portion having a smaller diameter than the bulging portion is formed at an end of the space holding piece on the side opposite to the gripping portion. In this case, when applied to the anchor made of the deformed steel bar as described above, even when the end portion is in contact with the anchor surface, it is difficult to be caught by the uneven shape of the surface, and particularly, the free end side as described in the preceding paragraph is long. This is advantageous in a situation of moving in a direction.

  The spacer according to claim 4 is the spacer according to claim 1, in which a part of the peripheral wall has a diameter larger than that of the anchor connecting the spacing pieces and is opened along the axial direction on the side opposite to the holding portion of the spacing piece. A cylindrical portion is provided. In this case, not only is the shape stability of the spacer increased, but also on the side opposite to the gripping portion of the spacing member, almost the entire circumference of the anchor is surrounded. This has the effect of making it difficult for the anchor to fall off.

  In the spacer according to the fifth aspect, a part of the peripheral wall is formed in a substantially cylindrical shape that opens along the axial direction, and the opening-side ends thereof can be deformed inward and outward in the radial direction, and receive and hold the anchor inside. A grip portion, which is integral with the grip portion, and at least an intermediate portion at one end thereof extends at substantially equal intervals in the circumferential direction along the longitudinal direction of the anchor and bulges radially outward, An anchor spacer having at least three spacing pieces for holding the gap between the anchor and the wall at a predetermined distance by contacting the gap with the wall face of the drilling, wherein the spacing pieces are each provided on at least one end side with an anchor. A part of the peripheral wall having a diameter larger than that is connected by a cylindrical portion that opens along the axial direction, and the cylindrical portion is connected to the grip portion in the axial direction through a notch in the circumferential direction. Is characterized by To have.

  According to the above configuration, for the gripping portion that is deformed according to the magnitude of the outer diameter of the anchor, the interval holding piece whose end is connected by the cylindrical portion is interposed between the gripping portion and the cylindrical portion. It is substantially separated by a circumferential cutout of a predetermined length. That is, even if the substantially cylindrical grip portion and the cylindrical portion are integrated, they are connected to each other only at a part of the peripheral wall. There is little effect on Thus, like the spacer according to each of the above-mentioned claims, this spacer has high adaptability to the magnitude of the anchor outer diameter. Further, if a cylindrical portion similar to the grip portion side is provided on the other end side of the gap holding piece, the effect of preventing the gap holding piece from falling off from the anchor is further enhanced. Note that the deformation of the grip portion when attached to the anchor is greater as approaching the opening end, and the position facing the opening end with the axis is the smallest. Therefore, it is preferable that the notch in the circumferential direction is provided leaving the vicinity of the position facing the opening side end.

  The spacer according to claim 6 is characterized in that, in each of the above configurations, the opening-side end of the grip portion is folded back to the outer peripheral surface side. In this case, the anchor can be attached from the side surface of the anchor using the opening, which is very effective in increasing the efficiency of the attaching operation.

  A spacer according to a seventh aspect of the present invention is characterized in that, in each of the configurations of the first to sixth aspects, at least the grip portion and the spacing member are integrally formed of a spring steel material. In this case, the elastic deformation of these portions makes it easy to follow changes in the outer diameter of the anchor and the diameter of the drilled hole, which is extremely effective in expanding the applicable range of the spacer.

  The spacer according to claim 8 is formed in a substantially cylindrical shape in which a part of the peripheral wall is opened along the axial direction, and a grip portion that elastically grips the anchor by receiving the anchor internally from the opening side. At one end of the gripping portion, extending at substantially equal intervals in the circumferential direction along the longitudinal direction of the anchor, and bulging radially outward, with the top of the bulging portion elastically facing the wall surface of the drilling hole. A plurality of gap holding pieces that abut against each other and hold the gap between the anchor and the wall surface at a predetermined gap, and at least at the other end side of the gap holding pieces and at substantially the same circumferential position as the opening of the gripping portion. It is characterized in that a part of the peripheral wall is opened, and a tubular part for receiving the anchor from the opening side thereof into the interior in a loosely fitted state is formed integrally with an elastic plate material.

  According to such a configuration, each of the spacing members is fixed at one end by the grip portion, but at the other end side, the cylindrical portion is loosely fitted to the anchor. With the expansion and contraction of the bulging portion in the radial direction, the bulging portion can move forward and backward in the longitudinal direction of the anchor integrally with the tubular portion. That is, when at least one of the plurality of interval holding pieces contacts the rock or the like protruding from the inner surface of the excavation hole and is pressed inward (anchor side), they are gripped with a substantially cylindrical grip portion at both ends. Respectively, and the rigidity based on the overall cylindrical shape thereof suppresses the deformation of the individual spacing members, and all the spacing members cooperate with each other to extend in the longitudinal direction of the anchor. Anchors equipped with this spacer, when inserted, allow each of the spacing pieces to easily follow the unevenness of the inner surface of the digging hole and be elastically deformed without difficulty, thereby improving insertability and installing the anchor at the axis of the digging hole. It becomes possible.

  Further, in the configuration according to the eighth aspect, when the opening side ends of the grip portion and the cylindrical portion are turned to the outer peripheral surface side, it is easy to mount the anchor from the side surface using the opening. Therefore, there is a great effect on increasing the efficiency of the mounting operation. In addition, a slip-preventing means such as a projection may be provided on the grip portion. In this case, it is possible to effectively prevent the spacer from being displaced in the longitudinal direction when the anchor is inserted into the excavation hole.

  In the anchor spacer according to claims 1 to 7 of the present application, since a plurality of spacing pieces that perform the spacing function are separated from the influence of the gripping portion that is deformed according to the size of the outer diameter of the anchor to be applied, For example, even with the same name, an anchor having a variation in shape and size, such as a lock bolt, can be reliably installed at the axial center position of a borehole.

  In the anchor spacer according to the eighth to tenth aspects, each of the spacing members is fixed by the grip portion at one end, but the tubular portion is loosely fitted to the anchor at the other end. Therefore, the swelling portion formed by integral molding of the elastic plate material can be advanced and retracted in the longitudinal direction of the anchor integrally with the tubular portion with the radially expanding and contracting deformation. This facilitates insertion of the anchor into the borehole, and allows the anchor to be reliably installed at the axial center of the borehole.

  In the anchor spacer according to claims 1 to 7 of the present application, the opening-side end of the substantially cylindrical grip portion fitted to the outer peripheral surface of the anchor is deformed inward and outward in the radial direction so that various outer diameters are different. It can be applied to the anchor from the side by appropriately opening the opening. Such a grip portion may be provided only on one side of each spacing member, but may be provided on both sides. In the present invention, when there is a difference between the outer diameter of the anchor to be applied and the inner diameter of the grip portion, the influence of the deformation of the grip portion due to the mounting on the spacing pieces integrated therewith is reduced. There is a technical feature in this point.

  That is, in the spacer according to any one of claims 1 to 4, among the at least three spacing pieces integrated with the grip portion, two of the spacing pieces near the opening-side end are provided with the anchor. It is characterized in that, for example, the base portion on the gripping portion side is inclined inward in the circumferential direction with respect to the bulging portion parallel to the longitudinal direction, and is removed from the extension line of the bulging portion. By adopting such a shape, when the gripping portion expands or contracts according to the magnitude of the outer diameter of the anchor, the inclined portion mitigates the influence of their deformation, causing a large change in the arrangement state of the bulging portion. It will be difficult. Further, in the spacer according to claim 5, a notch of a predetermined length continuing in a circumferential direction with a cylindrical portion connecting each spacing holding piece at one end side to a substantially cylindrical grip portion deformed according to the magnitude of the anchor outer diameter. The spacers are separated from the gripping portions substantially by connecting them via the through holes, thereby reducing the effect.

  In the spacers according to claims 1 to 7, there is no particular limitation as long as the number of the spacing members is three or more, but preferably four. For example, in the case of three spacing pieces, one piece should be placed near the opening side end of the gripper, and the other piece should be placed at a position facing the opening side end with respect to the axis. It suffices that the distance between the spacing members is approximately 120 degrees. As for the material, a material having high elasticity such as a spring steel material is suitable for the reason that the applicable range of the drilling diameter is expanded, but a normal steel material or a synthetic resin can also be used. In the spacers according to the eighth to tenth aspects, integral molding of an elastic material is essential based on the configuration. Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  1 to 3 show a first embodiment of an anchor spacer according to the present invention, and are a front view, a plan view and a side view, respectively. The illustrated anchor spacer 1 is made of a steel plate having an appropriate elasticity, and has a substantially cylindrical gripping portion 11 and four spacing holding pieces 12a provided integrally with the gripping portion 11 on one end side in the axial direction thereof. , 12b, 12c, and 12d. The grip portion 11 has a part of the peripheral wall divided in the axial direction and is opened, and each of the opening-side ends 13, 13 is folded back to the outer peripheral surface side. Further, two projections 14 are provided at opposing positions on the inner surface of the peripheral wall with respect to the axis. The number of the protrusions 14 is not an essential requirement in the present invention. The four spacing pieces 12a, 12b, 12c, and 12d are bent at one edge of the grip portion 11 to form inclined portions 15a, 15b, 15c, and 15d that extend obliquely outward in the radial direction. Are bent further at a position closer to the grip portion 11 than the center, and the remaining portion is formed as bulging portions 16a, 16b, 16c, 16d parallel to the axis of the grip portion 11.

  Next, the positional relationship between the grip portion and the spacing member, which is a technical feature of the present invention, will be described in detail with reference to FIG. Here, the four bulging portions 16a, 16b, 16c, and 16d in each of the space holding pieces 12a, 12b, 12c, and 12d are arranged at substantially 90-degree intervals so as to be equally spaced in the circumferential direction in the non-mounted state. Be placed. Among these, the two interval holding pieces 12b, 12c located on the back side are such that the inclined portions 15b, 15c and the bulging portions 16b, 16c are only bent in the radial direction at the middle, and are not axially oriented. It extends on a straight line when viewed. However, the relationship between the two interval holding pieces 12a and 12d close to both the opening side ends 13 and 13 is completely different. In other words, in the inclined portions 15a, 15d of the two interval holding pieces 12a, 12d close to the opening side end portions 13, 13, the gripping portion 11 side approaches the inclined portions 15b, 15c located on the back side, respectively. It is out of the opposite position, and the cross-shaped arrangement is broken in a plan view. That is, when viewed from the front or the side, the inclined portions 15a and 15d appear to be slightly twisted.

  In addition, this type of anchor spacer is generally manufactured by press molding, and is obtained by first punching an appropriate steel plate into a comb shape, and rounding the base end portion of each tooth serving as a grip portion into a cylindrical shape. . In the present invention, as shown in FIG. 4, of the comb teeth 12a, 12b, 12c, and 12d, which will be spacing members after molding, the comb teeth 12a and 12d located at both ends are provided with base ends serving as grip portions. Punching is performed so that inclined sides 15a and 15d having a predetermined length are formed on the portion 11 side. Then, each of the comb teeth 12a, 12b, 12c, and 12d is bent obliquely to one side near the boundary with the base end portion 11 and further bent at a predetermined intermediate position so as to be parallel to the surface of the base end portion 11. When the whole is rounded into a cylindrical shape, the above-mentioned gripping portion 11, the inclined portions 15a, 15b, 15c, 15d and the bulging portions 16a, 16b, 16c, 16d are formed.

  Next, a method of mounting the anchor spacer 1 will be described with reference to FIGS. Here, an example is shown in which the anchor is applied to a lock bolt R made of a bamboo-shaped deformed reinforcing bar as an anchor. First, in order to mount the anchor spacer 1, the opening-side ends 13, 13 of the gripper 11 are addressed to the predetermined position of the lock bolt R from the side, and are strongly pressed. As a result, the opening-side ends 13, 13 open while resisting the elasticity of the material, and the lock bolt R is fitted inside the grip portion 11. In this case, the two protrusions 14 provided on the inner surface of the grip portion 11 are effective in preventing rotation with respect to the lock bolt R and displacement in the longitudinal direction. In this manner, the anchor spacer 1 according to the present invention can be mounted on the anchor by one-touch operation. In addition, when the outer diameter of the anchor to be mounted is smaller than the inner diameter of the grip portion 11, or when the gripping force by the grip portion 11 is to be increased to more reliably prevent detachment, use of an appropriate auxiliary member is effective. is there. For example, as shown in FIG. 7, the binding wire W is wound around the boundary between the grip portion 11 and each of the space holding pieces 12a, 12b, 12c, and 12d and tightened. A U-shaped clip for preventing the opening from straddling the back side of the folded portion of the 13, 13 may be fitted so as to be inserted in the axial direction of the grip portion 11.

  That is, the anchor spacer 1 responds to the magnitude of the outer diameter of the anchor to be applied by increasing or decreasing the diameter of the grip portion 11. In such a case, the amount of deformation of the peripheral wall of the grip portion 11 increases as it approaches the opening-side ends 13, 13. Therefore, if attention is paid to the spacing members 12a, 12b, 12c, and 12d, the spacing members 12a and 12d that are closer to the opening-side end portions 13 and 13 are easily affected. However, in the present invention, as described above, since the inclined portions 15a and 15d are off the extension lines with respect to the bulging portions 16a and 16d, the influence of the deformation of the grip portion 11 on the bulging portions 16a and 16d. Be relaxed. For this reason, the initial uniform arrangement of the bulging portions 16a, 16b, 16c, and 16d, that is, the distance from the axial center and the direction of the contact surface with respect to the inner surface of the bore do not significantly change.

  8 and 9 show a state where the lock bolt R is inserted into the hole H. In this case, the distance from the axis of each bulging portion 16a, 16b, 16c, 16d in the anchor spacer 1 is set to be larger than the inner diameter of the hole H. When the inclined portions 15a, 15b, 15c and 15d of the anchor spacer 1 come into contact with the entrance of the hole H and the inclined surface is pressed by the pressing force of the lock bolt R, it falls down to the base side of the lock bolt R. Deformed and inserted inside. That is, since these spacing members 12a, 12b, 12c, and 12d are free ends on one side and are curved and extend with a certain length, the bases of the inclined portions 15a, 15b, 15c, and 15d are connected to the nodes. The bulges 16a, 16b, 16c, 16d abut almost evenly against the inner surface of the borehole. Thereby, the lock bolt R can be installed at the center of the hole H.

  10 to 12 show a second embodiment of the anchor spacer according to the present invention, and are respectively a front view, a plan view and a side view. In the following embodiments, parts that are the same as those in the previous embodiment are denoted by the same reference numerals, and description thereof is omitted. The illustrated anchor spacer 2 is the same as the previous embodiment in that four spacers 21a, 21b, 21c, and 21d are provided integrally with the gripper 11. However, each of the interval holding pieces 21a to 21d is bent obliquely inward toward the axial center without ending the straight side on the anti-grip portion 11 side of the bulging portions 23a to 23d following the inclined portions 22a to 22d. Further, the terminal portions are turned back portions 24a to 24d. The folded portions 24a to 24d which are arranged at intervals of about 90 degrees in the circumferential direction have an interval between the folded portion 24a and the folded portion 21c and a gap between the folded portion 21b and the folded portion 24d which are opposed to each other. It is set smaller than. Also, the distal end portions of the folded portions 24a and 24d close to the opening side end portions 13 and 13 are not bent obliquely outward in a state of being directly opposed to the axial center like the other folded portions 24b and 24c. Under the influence of the inclined portions 22a and 22d, the contact portion is bent so as to be in contact with the contact portion in a slightly oblique state as compared with the facing state. That is, when the spacing pieces 21a and 21d are directed toward the axis, the bending lines of the folded portions 24a and 24d are oblique, while the bending lines of other folded portions 24a and 24d are orthogonal to the longitudinal direction.

  FIG. 13 shows a state in which the anchor spacer 2 is mounted on a lock bolt R. In the present embodiment, the bulging portions 23a to 23d, which perform the interval maintaining function, are also supported on the opposite side of the grip portion 11 by the folded portions 24a to 24d abutting on the lock bolts R. Increased elasticity. In general, a deformed bar having irregularities formed on the outer peripheral surface thereof, such as a bamboo bar or a screw bar, is frequently used for the lock bolt R. However, the anchor spacer 2 is attached by having the folded portions 24a to 24d. At the time of insertion or insertion into a drilled hole, the tips do not catch on the surface of the lock bolt R, and good workability can be obtained. In addition, as for the space | interval holding | maintenance piece 21a, 21b, 21c, and 21d, each part does not need to be clearly divided like the inclination parts 22a-22d and the bulging parts 23a-23d as mentioned above. Good.

  14 and 15 show a third embodiment of the anchor spacer according to the present invention, and are a side view and a plan view, respectively. The illustrated anchor spacer 3 is provided with a cylindrical portion 32 having a larger diameter than the grip portion 11 on the other end side of the spacing members 31a to 31d. As is apparent from FIG. 15, a part of the peripheral wall of the cylindrical portion 32 is opened along the axial direction, similarly to the grip portion 11, and the respective open side ends 33, 33 are folded back toward the outer peripheral surface. However, the inner diameter is set to be larger than the outer diameter of the anchor to be applied. The anchor spacer 3 can be easily and reliably attached to the anchor from the side surface by using the openings. In this case, the tubular portion 32 is very effective in preventing falling off by surrounding the anchor on the other end side of the anchor spacer 3 as well. The inner diameter of the tubular portion 32 is larger than the outer diameter of the anchor, and the other ends of the spacing pieces 31a to 31d are movable in the longitudinal direction of the anchor. 34d can be inserted smoothly without hindering the expansion / contraction deformation.

  16 and 17 show a fourth embodiment of the anchor spacer according to the present invention, and are a side view and a plan view, respectively. Unlike the above embodiments, the illustrated anchor spacer 4 has a configuration in which the spacing members 42a to 42d are substantially separated from the grip portion 41 that is deformed depending on the size of the anchor outer diameter. That is, cylindrical portions 43, 44 having a larger diameter than the grip portion 41 are provided at both end portions of each of the space holding pieces 42 a to 42 d, and one of the cylindrical portions 43 has the grip portion 41 sandwiching the cutout 45. Is connected to As is clear from FIG. 17, these cylindrical portions 43 and 44 have a part of the peripheral wall opened along the axial direction similarly to the grip portion 41, and the inner diameter is larger than the outer diameter of the anchor to be applied. Is set. In addition, the notch 45 occupies most of the circumference, and the grip part 41 and the cylindrical part 43 are connected by a part of the circumference. With such a configuration, even if the grip portion 41 expands and contracts according to the size of the anchor, the influence hardly reaches the space holding pieces 42a to 42d. Therefore, the desired uniform arrangement of the spacing members 42a to 42d is maintained, and the anchor can be reliably held at the center of the hole. In this case, the mountability to the anchor is not much different from that of the third embodiment, and the drop-out prevention effect and the insertability to the drilled hole by the tubular portions 43 and 44 are also the same. Note that the end of the spacing members 42a to 42d may be free ends without the cylindrical portion 44 on the other end side.

  18 to 21 show a fifth embodiment of the anchor spacer according to the present invention, and are respectively a front view, a left side view, a bottom view and a right side view. The illustrated anchor spacer 7 is formed by integral molding of a steel plate having an appropriate elasticity, and has a substantially cylindrical grip portion 71 and four intervals provided integrally with the grip portion 71 at one end in the axial direction thereof. It is composed of a holding piece 72 and a tubular portion 73 arranged on the other end side of the spacing piece 72.

  As shown in FIGS. 19 and 20, a part of the peripheral wall is divided in the axial direction so as to be in an open state, and both side ends 71a, 71a of the peripheral wall forming the opening 74 are located on the outer peripheral surface side. Is folded back. Further, a projection 71b is provided on the inner surface of the peripheral wall at a position opposing the opening 74 with respect to the axis. The projections 71b prevent displacement in the longitudinal direction due to insertion by engaging with the knot at an appropriate position with respect to an anchor having a knot on the outer peripheral surface such as a deformed bar, for example. The protrusions 71b are not an essential requirement in the present invention. Even when the protrusions 71b are provided, an appropriate number may be provided at an appropriate place of the grip portion 71. As is clear from FIG. 19, the grip portion 71 in the present embodiment is not flat on the entire peripheral wall, but has an arc portion on the protrusion 71b side with a larger curvature than the arc on both side portions thereof, and is almost flat. Has become something. This is because the cross-sectional shape of the anchor (lock bolt) to be applied is adjusted, and is not necessarily limited to this.

  On the other hand, as shown in FIG. 21 and the like, a part of the peripheral wall of the cylindrical portion 73 is opened in the axial direction in the same manner as the grip portion 71, and both end portions 73a, 73a forming the opening 75 are formed. It is folded back to the outer peripheral surface side. However, it is different from the above-mentioned grip portion 71 in that the inner diameter is set to be larger than the outer diameter of the lock bolt to be applied. This is because the cylindrical portion 73 can be smoothly displaced in the longitudinal direction on the lock bolt along with the diameter-reducing deformation of the four interval holding pieces 72 described later at the time of insertion into the excavation hole. The interval between the openings 75, including the opening 74 of the grip 71, is set smaller than the outer diameter of the lock bolt so that the opening cannot be easily removed. Further, as is clear from FIG. 20 and the like, the positions of the openings 74 and 75 in the circumferential direction are almost the same.

  The four spacing pieces 72 are located between the grip portion 71 and the cylindrical portion 73 and bulge in an arc shape such that the central portion has a maximum diameter. As is clear from FIGS. They are arranged at intervals of approximately 90 degrees in the direction. In this case, the interval between the central portions, which are the maximum diameter portions (top portions) of the interval holding pieces at the opposing positions, is set to be somewhat larger than the inner diameter of the excavation hole. The interval between the tops may be equal to or smaller than the inner diameter of the drill hole. In short, it is only necessary to hold the anchor near the center of the excavation hole and to secure a necessary covering thickness.

  Next, a method of using the anchor spacer 7 will be described. FIG. 22 shows a state where the lock bolt R (anchor) to which the anchor spacer 7 is attached is installed in the excavation hole H. The lock bolt R used here is formed of a threaded-shaped deformed steel bar, and two flat portions are formed on the outer peripheral surface thereof along the longitudinal direction at opposing positions sandwiching the axis. It has a shape divided by the part. At the time of mounting, at a predetermined position of the lock bolt R, the opening 74 of the grip portion 71 and the opening 75 of the cylindrical portion 73 are directed toward the row of screw joints, and are strongly pressed from behind. As a result, both side ends 71a, 71a and both side ends 73a, 73a open beyond the width between the flat portions of the lock bolt R while resisting the elasticity of the material. Goes over the flat part, and the lock bolt R fits into the grip part 71 and the cylindrical part 73. Here, the grip portion 71 resiliently grips the lock bolt R from the outer peripheral surface side, but does not grip the cylindrical portion 73 because its inner diameter is larger than the outer diameter of the lock bolt R. , So as not to hinder displacement in the longitudinal direction. However, since the width of the opening 75 is smaller than the width between the flat portions, the cylindrical portion 73 does not easily come off the lock bolt R. Thus, the anchor spacer 7 according to the present invention can be mounted on the lock bolt R by one-touch operation. When the gripping force of the gripping portion 71 is increased to more reliably prevent the detachment, for example, a U-shape for preventing the opening from straddling the both end portions 71a, 71a and the back side of the folded portion of the both end portions 73a, 73a. It is effective to use an appropriate auxiliary member such as using a clip in the shape of a circle or winding a binding wire around the boundary between the both end portions 71a, 71a and the spacing member 72.

  Here, in each of the interval holding pieces 72 curved outward in an arc shape, the distance from the axis of the anchor spacer 7 to the top of the center which is the maximum diameter portion is set to be slightly larger than the radius of the excavation hole H. ing. Further, the spacer 7 is mounted such that the grip portion 71 side is the tip end side of the lock bolt R. Then, with the insertion of the lock bolt R into the excavation hole H, each of the spacers 72 of the spacer 7 first comes into contact with the entrance of the excavation hole H, and the pressing force applied to the lock bolt R causes the inclined surface on the front side thereof. When pressed, it is deformed to fall to the lock bolt R side. That is, the central top portion receives a force in the direction of reducing the diameter. Further, since the cylindrical portion 73 is surrounded with an appropriate gap left relative to the lock bolt R, the cylindrical portion 73 can move in the longitudinal direction in conjunction with the expansion and contraction deformation of each spacing member 72. It has become. Therefore, the lock bolt R to which the spacer 7 is attached is smoothly inserted into the excavation hole H by appropriately elastically expanding and contracting the spacing members 72 in accordance with the unevenness of the inner surface of the excavation hole H. Can be installed in any location.

  FIGS. 23 and 24 are explanatory views showing the behavior of the above-described spacing holding piece 72 in the expansion and contraction deformation. In the spacer 7 according to the present invention, each of the spacing holding pieces 72 is restrained to a certain degree by its free elastic deformation by adopting an integrated structure in which the both ends are connected to the substantially cylindrical holding portion 71 and the cylindrical portion 73. ing. Therefore, when any one of the spacing members 72 receives a pressing force inward, the cylindrical portion 73 is pushed rearward as the spacing member 72 changes from the curved state to the flat state. At this time, since the other spacing members 72 are connected to the cylindrical portion 73 in the same manner, they also have a structure in which they are also reduced in diameter in conjunction with each other. That is, in the spacer 1 of the present invention, when a radial force from the outside toward the axis is applied to at least one of the spacing members 72, the radius at the central top corresponding to the maximum diameter portion becomes L1. At the same time, the total length of the spacer 1 is extended by L2. By exhibiting such behavior, it is possible to improve the insertability of the anchor, and at the same time, to install the anchor at the axial center position of the excavation hole H.

  In each of the above embodiments, the description has been given of the case where the number of the spacing members is four. However, it is needless to say that the number of the spacing members may be three or five or more. Various modifications within the spirit are of course possible.

It is a front view which shows an example of the spacer for anchors by this invention. It is a top view of the said anchor spacer. It is a side view of the said anchor spacer. It is explanatory drawing which shows the intermediate stage of the manufacturing process of the said anchor spacer. It is a side view which shows the mounting state of the said anchor spacer. It is a top view showing the mounting state of the above-mentioned anchor spacer. It is a side view which shows the mounting state which applied the binding wire to the said anchor spacer. It is a side view which shows the insertion state of the said anchor spacer in a hole. It is a side view which shows the insertion state of the said anchor spacer in a hole. It is a front view which shows the other example of the spacer for anchors by this invention. It is a top view of the said anchor spacer. It is a side view of the said anchor spacer. It is a side view which shows the mounting state of the said anchor spacer. FIG. 5 is a side view showing another example of the anchor spacer according to the present invention. It is a top view of the said anchor spacer. FIG. 5 is a side view showing another example of the anchor spacer according to the present invention. It is a top view of the said anchor spacer. FIG. 5 is a side view showing another example of the anchor spacer according to the present invention. It is a top view of the said anchor spacer. It is a front view of the said anchor spacer. It is a bottom view of the said anchor spacer. It is a side view which shows the use condition of the said anchor spacer. It is explanatory drawing which shows the expansion-contraction behavior of the spacing member in the said anchor spacer. FIG. 24 is a left side view of FIG. 23. It is a side view of the conventional anchor spacer. It is a top view of the said anchor spacer. It is a top view showing the mounting state of the above-mentioned anchor spacer.

Explanation of reference numerals

1, 2, 3, 4, 5, 7, ... spacers for anchors, 6, 11, 41, 71 ... gripping parts, 12a to 12d, 21a to 21d, 31a to 31d, 42a to 42d, 5A to 5D, 72 ... intervals Holding pieces, 13, 33, 71a, 73a: Open end, 14, 71b: Projection, 15a to 15d, 22a to 22d: Inclined part, 16a to 16d, 23a to 23d, 34a to 34d: Swelled part, 32 , 43, 44, 73 ... cylindrical part, 45 ... notch, 74, 75 ... opening, R ... lock bolt

Claims (10)

  A part of the peripheral wall is formed in a substantially cylindrical shape that is open along the axial direction, and the opening side ends thereof are deformable inward and outward in the radial direction, respectively, and a gripper that receives and grips the anchor inside; At one end, at least an intermediate portion extends circumferentially at substantially equal intervals along the longitudinal direction of the anchor and bulges radially outward, and the bulge contacts the wall surface of the drilled hole. An anchor spacer having at least three spacing holding pieces for holding at least a predetermined spacing between an anchor and a wall surface, wherein two of the spacing holding pieces have a bulging portion with respect to the grip portion. An anchor spacer, wherein the spacer is located at a position closer to the opening-side end in the direction, and the intersection with the grip portion is located inward in the circumferential direction from the bulging portion.   2. The anchor spacer according to claim 1, wherein a side of the gap holding piece opposite to the gripping portion is formed as a free end. 3.   The anchor spacer according to claim 1, wherein a folded portion having a smaller diameter than a bulging portion is formed at an end of the gap holding piece on the side opposite to the gripping portion.   The space holding member further includes a tubular portion having a diameter larger than that of an anchor connecting the space holding pieces and having a part of a peripheral wall opened along an axial direction on an opposite side of the gripping portion. An anchor spacer as described in the above.   A part of the peripheral wall is formed in a substantially cylindrical shape that is open along the axial direction, and the opening side ends thereof are deformable inward and outward in the radial direction, respectively, and a gripper that receives and grips the anchor inside; At one end, at least an intermediate portion extends circumferentially at substantially equal intervals along the longitudinal direction of the anchor and bulges radially outward, and the bulge contacts the wall surface of the drilled hole. What is claimed is: 1. An anchor spacer comprising at least three spacing members for holding at least a predetermined distance between an anchor and a wall surface, wherein each of the spacing members has a diameter larger than that of the anchor on at least one end side of the peripheral wall. The parts are connected by a cylindrical part that opens along the axial direction, and the cylindrical part is connected to the grip part in the axial direction through a circumferential cutout. Spacer.   The anchor spacer according to any one of claims 1 to 5, wherein an opening-side end of the grip portion is folded back to an outer peripheral surface side.   The anchor spacer according to any one of claims 1 to 6, wherein the grip portion and the spacing member are integrally formed of a spring steel material.   A part of the peripheral wall is formed in a substantially cylindrical shape that opens along the axial direction, and a grip portion that receives the anchor from the opening side and resiliently grips the anchor, and has one end side of the grip portion. It extends along the longitudinal direction of the anchor at substantially equal intervals in the circumferential direction and bulges radially outward, and the top of the bulging portion is elastically brought into contact with the wall surface of the excavation hole, so that the anchor and the wall surface A plurality of spacing pieces that hold the gap at a predetermined interval, and a part of the peripheral wall is opened at at least the same circumferential position as the opening of the gripping part at least at the other end side of these spacing pieces, and the anchor is fixed. An anchor spacer, characterized in that a tubular portion for receiving a loose fit into the inside from the opening side is integrally formed of an elastic plate material.   The anchor spacer according to claim 8, wherein an opening-side end of the grip portion and the tubular portion is folded back to an outer peripheral surface side.   The anchor spacer according to claim 8, wherein the grip portion is provided with a slip prevention unit.

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