Anchor bolt and anchor bolt fixation structure

Abstract

To provide an anchor bolt that suppresses cracks in a hardener surface portion around an embedded shaft portion of an anchor bolt body.SOLUTION: An anchor bolt comprises an anchor bolt body 3 having an embedded shaft portion 30 embedded in concrete (hardener) 1 and an exposed shaft portion 34 positioned in a withdrawal direction from the embedded shaft portion 30. The embedded shaft portion 30 comprises: an adhesion shaft portion 32 formed with an uneven surface; and a smooth shaft portion 31 formed with a smooth surface. The smooth shaft portion 31 is positioned between the adhesion shaft portion 32 and the exposed shaft portion 34.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an anchor bolt and anchor bolt fixing structure that are bonded to a hardening material such as concrete and that can resist pull-out forces generated by the adhesion of the attachment shaft. [Background technology]

[0002] The main anchor bolt fixing mechanisms include types that use deformed steel rods to improve adhesion, types with hooks attached to the tip of the above type, and types with a head attached to the tip of the steel rod to improve bearing force. Also, depending on when the anchor bolt is installed, there are two types: buried anchors (at the time of installation) and post-installed anchors.

[0003] The post-installed anchor described in Patent Document 1 is proposed to form a peripheral groove in the anchor hole wall, and to pre-install an anchor bar with a fixing part at the end of a reinforcing bar with a male thread or the like formed as an irregular pattern, and then fill it with cement-based grout or the like as a filler and let it harden, thereby exerting adhesion and bearing pressure and ensuring long-term strength. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-79720 Summary of the Invention [Problem to be solved by the invention]

[0005] In a mechanism that resists pull-out by the adhesive force of deformed rebars embedded in a hardening material such as concrete, shear forces act in shallow areas around the embedded deformed rebars, which can easily cause cracks on the surface of the hardening material. When such cracks occur, the strength of the hardening material decreases, and repairs to the cracked areas are often required.

[0006] The present invention has been made in view of the above-mentioned problems, and has an object to provide an anchor bolt and an anchor bolt fixing structure that suppress cracking of the surface portion of the hardened material around the embedded shaft portion. [Means for solving the problem]

[0007] The invention of claim 1 is an anchor bolt comprising an anchor bolt body having an embedded shank portion embedded in a hardening material and an exposed shank portion located in the pull-out direction from the embedded shank portion, wherein the embedded shank portion has an attached shank portion formed with an uneven surface and a smooth shank portion formed with a smooth surface, and the smooth shank portion is located between the attached shank portion and the exposed shank portion.

[0008] The invention of claim 2 is the anchor bolt according to claim 1, characterized in that it comprises an anchor body provided on the anchor bolt body, the anchor bolt body further having an anchor body shank portion located further back than the attachment shank portion and on which the anchor body is provided, the anchor body having a protruding anchoring surface portion that protrudes outward from the outer peripheral surface of the anchor body shank portion and faces the pull-out direction of the anchor bolt to resist pull-out, and the anchor body shank portion is formed with an outer diameter smaller than that of the exposed shank portion.

[0009] An invention according to claim 3 is the anchor bolt according to claim 2, characterized in that the protruding fixing surface portion is located within an area surrounded by a locus of the outermost periphery when the attachment shaft portion is rotated around the axis of the anchor bolt body as viewed from the pull-out direction.

[0010] The invention of claim 4 is the anchor bolt according to claim 2, characterized in that the protruding fixing surface portion is located within an area surrounded by a locus of the outermost periphery when the exposed shank portion is rotated around the axis of the anchor bolt body as viewed from the pull-out direction.

[0011] The invention of claim 5 is an anchor bolt described in any one of claims 2 to 4, characterized in that the fixing bodies are provided in plurality in the direction of extraction of the anchor bolt from the fixing body shaft portion.

[0012] The invention according to claim 6 is the anchor bolt according to any one of claims 2 to 4, characterized in that the exposed shank portion has a threaded portion on its outer circumferential surface.

[0013] The invention of claim 7 is an anchor bolt fixing structure in which an anchor bolt having an anchor bolt body is fixed in hardened material, wherein the anchor bolt body has an embedded shank portion embedded in the hardened material and an exposed shank portion located in the pull-out direction from the embedded shank portion, the embedded shank portion has an attached shank portion formed with an uneven surface and a smooth shank portion formed with a smooth surface, and the smooth shank portion is located between the attached shank portion and the exposed shank portion and is embedded in the hardened material.

[0014] The invention of claim 8 is the anchor bolt fixing structure described in claim 7, characterized in that the anchor bolt comprises an anchor body provided on the anchor bolt body, the anchor bolt body further having an anchor body shank portion located deeper than the attachment shank portion and on which the anchor body is provided, the anchor body having a protruding fixing surface portion that protrudes outward from the outer peripheral surface of the anchor body shank portion and faces the pull-out direction of the anchor bolt to resist pull-out, the anchor body shank portion is formed with an outer diameter smaller than the exposed shank portion, and the anchor body shank portion and the anchor body are embedded in the hardening material.

[0015] The invention of claim 9 is the anchor bolt fixing structure according to claim 8, characterized in that the protruding fixing surface portion is located within an area surrounded by a locus of the outermost periphery when the attachment shaft portion is rotated around the axis of the anchor bolt body when viewed from the pull-out direction, and is embedded in the hardening material.

[0016] The invention of claim 10 is the anchor bolt fixing structure according to claim 8, characterized in that the protruding fixing surface portion is located within an area surrounded by a locus of the outermost periphery when the exposed shank portion is rotated around the axis of the anchor bolt body when viewed from the pull-out direction, and is embedded in the hardening material.

[0017] The invention of claim 11 is an anchor bolt fixing structure described in any one of claims 8 to 10, characterized in that the fixing bodies are provided in multiple numbers in the pull-out direction of the anchor bolt of the fixing body shaft portion.

[0018] The invention according to claim 12 is the anchor bolt fixing structure according to any one of claims 8 to 10, characterized in that the exposed shaft portion has a threaded portion on its outer circumferential surface. [Effects of the Invention]

[0019] In the anchor bolt and anchor bolt fixing structure of the present invention, the buried shank that is buried in the hardened material is provided with a smooth shank that is formed with a smooth surface between the attached shank and the exposed shank that is exposed from the hardened material. Therefore, the smooth shank, which has reduced adhesive force acting on the hardened material, reduces the shear force that occurs in the shallow part around the hardened material, and while ensuring the adhesive force of the attached shank, it is possible to suppress cracking of the surface of the hardened material around the buried shank.

[0020] In addition, by providing the anchor at the anchor shaft located at the back of the attached shaft, the overall length of the anchor bolt can be shortened without reducing the pull-out strength, and since the diameter of the anchor shaft is made smaller than that of the exposed shaft, the area of ​​the anchor can be increased accordingly, and the anchor does not protrude significantly outward, preventing the overall diameter of the anchor bolt from increasing.As a result, it is possible to prevent the concrete frame from becoming larger, reducing costs, and minimizing interference with rebar, improving workability.In particular, for post-installed anchors, which require drilling a hole in concrete, inserting the anchor bolt, and filling it with adhesive filler, the hole diameter can be reduced, improving workability.

[0021] In addition, since the protruding fixing surface portion is located within the area surrounded by the trajectory of the outermost periphery when the attached shaft portion or exposed shaft portion is rotated around the axis, the amount of protrusion of the fixing body is further reduced, and the diameter of the anchor bolt can be made smaller.

[0022] In addition, by providing multiple anchors in the pull-out direction, the area of ​​the protruding anchoring surface can be secured without increasing the diameter of the anchors, which further reduces interference with rebar and allows the drilling diameter to be reduced for post-installed anchors. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 is a side view of an anchor bolt according to a first embodiment. [Figure 2] FIG. 2 is a bottom view of the anchor bolt according to the first embodiment. [Figure 3] FIG. 10 is a side view of the anchor bolt according to the second embodiment. [Figure 4] FIG. 10 is a side view of the anchor bolt according to the third embodiment. [Figure 5] FIG. 10 is a side view of an anchor bolt according to a fourth embodiment. [Figure 6] FIG. 10 is a vertical cross-sectional view of an anchor bolt according to a fifth embodiment. [Figure 7] FIG. 10 is a vertical cross-sectional view of an anchor bolt according to a sixth embodiment. [Figure 8] FIG. 13 is a side view of the anchor bolt according to the seventh embodiment. [Figure 9] FIG. 13 is a longitudinal sectional view of an anchor bolt according to an eighth embodiment before cutting. [Figure 10] FIG. 13 is a side view of the anchor bolt according to the ninth embodiment. [Figure 11] FIG. 20 is a side view of the anchor bolt according to the tenth embodiment. [Figure 12] FIG. 10 is a side view of a modified anchor bolt. DETAILED DESCRIPTION OF THE INVENTION

[0024] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. However, it goes without saying that the present invention is not limited to the embodiments described below.

[0025] [First embodiment] 1 and 2 show a first embodiment of the present invention. FIG. 1 is a side view of the anchor bolt, and FIG. 2 is a bottom view of the anchor bolt.

[0026] The first embodiment is applied to an anchor bolt 2 that is installed vertically as an embedded anchor embedded in concrete 1 that forms the skeleton of a structure with a horizontally exposed surface, such as a foundation. Figure 1 shows the anchor bolt fixing structure in which the anchor bolt 2 is embedded and fixed in the hardened concrete 1.

[0027] The drawings show coordinate axes X, Y, and Z. The direction in which the anchor bolt 2 is pulled out is the Z-axis direction, and the horizontal plane is shown as the XY plane formed by the X-axis (the left-right direction in FIG. 1) and the Y-axis (the depth direction in FIG. 1).

[0028] The anchor bolt 2 includes an anchor bolt body 3 and a fixing body 4 provided on the anchor bolt body 3.

[0029] The anchor bolt body 3 is formed in a substantially axial shape and has a linear axis 3' (set in the Z-axis direction). The anchor bolt body 3 is formed including a deformed steel bar with a screw groove 32a formed on the outer peripheral surface of a general steel material.

[0030] The anchor bolt body 3 includes an embedded shank 30 that is embedded in concrete 1, which is a hardening material, and an exposed shank 34 that is positioned in the pull-out direction from the embedded shank 30 and is exposed from the concrete 1.

[0031] The exposed shaft portion 34 is fitted with, for example, a through-hole in a base plate (not shown), and a nut is screwed into the thread groove of the exposed threaded portion 34a formed on the outer circumferential surface, thereby providing a base plate or the like.

[0032] The exposed thread portion 34a is formed by cutting the outer peripheral surface of the deformed steel bar, etc. The outer diameter d0 of the exposed thread portion 34a is smaller than the outer diameter d1 of the attachment shaft portion 32, which will be described later.

[0033] In FIG. 1, the upper part of the exposed shaft portion 34 is omitted. The exposed shaft portion 34 is the portion that is exposed from the concrete 1, and is therefore located above, or in front of, the attached shaft portion 32 that is buried.

[0034] The buried shaft portion 30 has a smooth shaft portion 31 formed with a smooth surface, an attachment shaft portion 32 formed with an uneven surface, and an anchor shaft portion 33 located below the attachment shaft portion 32, i.e., at the rear side where it is installed deeper into the concrete 1 than the attachment shaft portion 32.

[0035] The smooth shaft portion 31 is located between the attached shaft portion 32 and the exposed shaft portion 34, and the embedded shaft portion 30 is embedded in the concrete 1 so that the upper end of the smooth shaft portion 31 is flush with the surface of the concrete 1. The smooth shaft portion 31 has a smooth outer surface that suppresses the effect of the adhesive force of the concrete 1, and adhesion to the concrete 1 is not taken into consideration in the design.

[0036] The smooth shaft portion 31 is formed by smoothly cutting the outer peripheral surface of a deformed steel bar, and the outer diameter d4 of the smooth shaft portion 31 is equal to the outer diameter d0 of the exposed thread portion 34a.

[0037] The attachment shaft portion 32 is formed by the outer contour of a deformed steel bar with a thread groove 32a integrally formed as an uneven surface on the outer periphery, and resists pulling out of the anchor bolt 2 by friction and adhesion between the concrete 1 and the surface shape of the attachment shaft portion 32. The attachment shaft 32 is formed as a single unit, and has no movable parts like the expandable type (diameter expansion type), making the structure simple and less likely to break. Also, the installation is completed simply by pouring and hardening the concrete 1, so there is no need for a process to move the movable parts like the expandable type, making it simple. Furthermore, since there is no movable enlarged diameter section, when used as a post-installed anchor, the drilled hole diameter can be made smaller, and interference with nearby obstacles such as rebar can be suppressed. Furthermore, since there is no movable enlarged diameter portion, the amount of hardener to be filled can be reduced. Furthermore, if a movable enlarged diameter section is present, it is difficult for the hardening material to reach the back side of the enlarged diameter section, whereas since there is no movable enlarged diameter section, the hardening material to be filled can easily reach the back side of the enlarged diameter section, improving filling performance and improving construction efficiency and safety.

[0038] The outer diameter d1 of the attachment shaft portion 32 is larger than the outer diameter d0 of the exposed thread portion 34a. The attachment shaft portion 32 has a strong adhesive force to the concrete 1 due to the screw groove 32a.

[0039] The screw grooves 32a may be extended upward along the exposed shaft portion 34 at the same pitch to form an exposed screw portion 34a.

[0040] In this case, the exposed shank 34 is also formed by the outer shape of the deformed steel bar. That is, in this case, the outer diameter d1 of the attached shank 32 is equal to the outer diameter d0 of the exposed threaded portion 34a.

[0041] The anchor shaft portion 33 is axially shaped and has a smaller outer diameter than the attachment shaft portion 32 (the outer diameter d2 of the anchor shaft portion 33 is smaller than the outer diameter d1 of the attachment shaft portion 32), and is formed, for example, from round steel, and is fixed to the lower end surface of the attachment shaft portion 32 by welding or the like, sharing the axis 3'.

[0042] In this embodiment, the outer diameter d2 of the fixing body shaft portion 33 is smaller than the outer diameter d0 of the exposed shaft portion 34 (exposed thread portion 34a).

[0043] The fixing body shaft portion 33 is provided with a plurality of fixing bodies 4 (two in this embodiment). These anchor bodies 4 are circular steel plates and are attached to the outer surface of the anchor body shaft portion 33 by welding or the like in multiple stages (two stages in this embodiment) spaced apart from each other in the pull-out direction (Z direction) of the anchor bolt 2, and protrude outward from the outer surface of the anchor body shaft portion 33.

[0044] The upper surface of each anchoring body 4, which is approximately parallel to the plane XY, becomes a protruding anchoring surface portion 40 that faces the pull-out direction of the anchor bolt 2 and generates a bearing capacity against the pull-out. The bearing capacity is based on the compressive strength of the concrete 1 and resists the pull-out force of the anchor bolt 2.

[0045] When viewed from the pull-out direction, the trajectory of the outermost circumference of the attachment shank 32 rotated around the axis 3' of the anchor bolt body 3 is a circle on a plane parallel to the plane XY, and the protruding fixing surface 40 is located within the area surrounded by this trajectory. In other words, the outer diameter d3 of the fixing body 4 is smaller than the outer diameter d1 of the attachment shank 32.

[0046] In this embodiment, the two fixing bodies 4 have the same diameter, and the outer diameter d3 thereof is smaller than the outer diameter d1 of the attachment shaft portion 32.

[0047] Furthermore, the outer diameter d3 of the fixing body 4 is smaller than the outer diameter d0 of the exposed shank 34 (exposed thread portion 34a). In other words, when viewed from the pull-out direction, the trajectory of the outermost circumference when the exposed shank 34 is rotated around the axis 3' of the anchor bolt body 3 is a circle on a plane parallel to the plane XY, and the protruding fixing surface portion 40 is located within the area surrounded by this trajectory.

[0048] The outer diameter d3 of the fixing body 4 may be larger than the outer diameter d0 of the exposed shaft portion 34 (exposed threaded portion 34a).

[0049] In the direction of pulling out the anchor bolt 2, it is desirable that the length L0 of the smooth shank 31 be two to three times the outer diameter d0 of the exposed shank 34 (exposed threaded portion 34a), and the length L from the upper end of the smooth shank 31 to the protruding fixing surface portion 40 of the lower fixing body 4 be eight to ten times the outer diameter d0 of the exposed shank 34 (exposed threaded portion 34a).

[0050] Furthermore, the length L2 of the fixing body shaft portion 33 is shorter than the length L1 of the adhesive shaft portion 32, and although it depends on the number of fixing bodies 4, it is desirable to set it to, for example, about 10 mm to 100 mm. If it is shorter than this, the concrete 1 will not be able to fill the outer periphery of the anchor shaft portion 33 and the spaces between the anchors 4 as easily, and if it is longer than this, the embedded shaft portion 30 will no longer be compact.

[0051] The outer diameter d2 of the fixing body shaft portion 33 is preferably 50% to 80% of the outer diameter d1 of the attachment shaft portion 32. If it is thinner than this, there is a risk that the fixing body shaft portion 33 will undergo tensile yield, and if it is thicker than this, the protruding fixing surface portion 40 of the fixing body 4 will become narrow, and in order to ensure a sufficiently wide protruding fixing surface portion 40, the fixing body 4 will have to be made larger.

[0052] The anchor bolt 2 is embedded in the concrete 1 in the following manner. The anchor bolt 2 is supported and placed by an appropriate support means with the anchor body shank 33 facing the rear (lower side in FIG. 1) and the exposed shank 34 facing the front (upper side in FIG. 1). Thereafter, concrete 1 is poured up to the boundary between the smooth shank 31 and the exposed shank 34 of the embedded shank 30 and allowed to harden. Once the concrete 1 has hardened, the anchor bolt 2 that was placed before the concrete 1 was poured is embedded in the hardened concrete 1 in the same position and installed.

[0053] When the embedded shank 30 of the anchor bolt 2 is embedded in the concrete 1, a pull-out force acting on the exposed shank 34 transmits stress from the top to the bottom of the embedded shank 30 in that order. In other words, when a pull-out force is applied to the anchor bolt 2, the smooth shank 31, which does not take into account the adhesive strength to the concrete 1, offers almost no resistance, but the adhesive strength of the next adhesive shank 32 provides resistance, and only the stress that cannot be offset is transmitted to the anchor shank 33.

[0054] Therefore, cracks are unlikely to occur on the surface of the concrete 1 around the smooth shaft portion 31 which does not resist pulling out. Furthermore, since the attachment shaft portion 32 is embedded relatively deeply in the concrete 1, cracks are unlikely to occur on the surface of the concrete 1 due to the shear force from this portion.

[0055] The outer diameter d2 of the anchoring body shaft portion 33, to which a small stress is applied, can be made smaller than the outer diameter d1 of the attachment shaft portion 32, so that the anchoring body shaft portion 33 does not undergo tensile yielding.

[0056] Since cracks on the surface of the concrete 1 are suppressed in this way, there is no risk of a decrease in the strength of the concrete 1, and there is no need to repair the concrete 1. In other words, a method for suppressing cracks on the surface of the concrete 1 around the anchor bolt 2 is provided.

[0057] In addition, by reducing the outer diameter d2 of the anchor shaft portion 33, the area of ​​the protruding anchoring surface portion 40 can be increased accordingly.Therefore, even if the bearing capacity is ensured, the diameter of the anchor 4 protruding outward from the outer peripheral surface of the anchor shaft portion 33 can be prevented from increasing, thereby preventing the concrete body from becoming larger and improving economy.

[0058] In addition, by keeping the diameter of the anchor 4 small, interference with the reinforcing bars placed in the concrete 1 can be suppressed, improving workability. Furthermore, if the outer diameter d2 of the fixing body shaft portion 33 is made smaller than the outer diameter d0 of the exposed shaft portion 34, the above effect can be further improved.

[0059] In this embodiment, sufficient pull-out resistance can be ensured by having the protruding fixing surface portions 40 of the two fixing bodies 4. That is, by providing surfaces that resist pull-out and face the pull-out direction in multiple stages in the vertical direction, sufficient pull-out resistance is ensured.

[0060] Second Embodiment A second embodiment of the present invention will be described with reference to Fig. 3. Note that a description of the same parts as in the first embodiment will be omitted, and the following mainly focuses on the different parts. FIG. 3 is a side view of the anchor bolt showing the second embodiment.

[0061] The difference from the first embodiment is that the attachment shaft portion 32 is not a threaded shaft with a screw groove formed on the outer surface, but a deformed steel bar with a spiral protrusion 320 welded to the outer surface of the round steel.

[0062] By providing the spiral ridge 320 on the outer peripheral surface, the attachment shank 32 can withstand the pull-out force of the anchor bolt 2 with sufficient adhesion force.

[0063] In this embodiment, the spiral ridge 320 is provided on the outer peripheral surface of the round steel bar by welding, but it may also be an integrally formed deformed steel bar.

[0064] Third Embodiment A third embodiment of the present invention will be described with reference to Fig. 4. Note that a description of the same parts as in the first and second embodiments will be omitted, and the following mainly describes the different parts. FIG. 4 is a side view of the anchor bolt showing the third embodiment.

[0065] The third embodiment differs from the first embodiment in that there is only one fixing body 4. As described above, the stress caused by the pull-out force of the anchor bolt 2 is transmitted from the top to the bottom of the embedded shaft 30, so even if there is only one anchor 4 provided on the anchor shaft 33 at the bottom of the embedded shaft 30, it can exert sufficient bearing strength against pull-out.

[0066] [Fourth embodiment] A fourth embodiment of the present invention will be described with reference to Fig. 5. Note that a description of the same parts as those in the first to third embodiments will be omitted, and the following mainly focuses on the differences. FIG. 5 is a side view of an anchor bolt showing the fourth embodiment.

[0067] The fourth embodiment differs from the first embodiment in that the outer diameter d3 of the fixing body 4 is larger than the outer diameter d1 of the attachment shaft portion 32. In addition, the outer diameter d3 of the fixing body 4 is larger than the outer diameter d0 of the exposed shaft portion 34 (exposed thread portion 34a).

[0068] Even if the outer diameter d3 of the fixing body 4 is increased to further widen the area of ​​the protruding fixing surface portion 40 and strengthen the bearing pressure capacity, the fixing body 4 only needs to protrude slightly outward from the trajectory of the outermost circumference when the attachment shaft portion 32 is rotated around the axis 3' of the anchor bolt body 3, and this prevents the diameter of the fixing body 4 from becoming larger.

[0069] Fifth Embodiment A fifth embodiment of the present invention will be described with reference to Fig. 6. Note that a description of the same parts as in the first to fourth embodiments will be omitted, and the following mainly focuses on the differences. FIG. 6 is a vertical cross-sectional view of an anchor bolt showing the fifth embodiment.

[0070] In this embodiment, the anchor shaft 33 is not a round steel bar, but a threaded steel bar with a screw groove 33a formed on its outer peripheral surface, and the anchor 4 is a circular steel plate with an internal thread surface 41, and the anchor 4 and the anchor shaft 33 are screwed together, which is different from the first embodiment.

[0071] Another difference from the first embodiment is that the thread grooves 32a of the attached shank 32 extend upward at the same pitch along the exposed shank 34 to form an exposed threaded portion 34a. The exposed shank 34 is also formed by the outer contour of the deformed steel bar.

[0072] Between the attached shank portion 32 and the exposed shank portion 34, the outer surface of the threaded steel rod is smoothly cut to form a smooth shank portion 31. That is, the outer diameter d1 of the attached shank 32 is equal to the outer diameter d0 of the exposed threaded portion 34a, and the outer diameter d4 of the smooth shank 31 is smaller than the outer diameter d1 of the attached shank 32 and the outer diameter d0 of the exposed threaded portion 34a.

[0073] The screw groove 32a of the attached shank 32 and the exposed screw portion 34a of the exposed shank 34 may be formed continuously by cutting.

[0074] According to this embodiment, the number of fixing bodies 4 and their mounting positions in the pull-out direction (Z direction) can be changed as appropriate, and when multiple fixing bodies 4 are provided, the spacing between the fixing bodies 4 can also be adjusted.

[0075] Furthermore, the fixing body 4 can be provided in a stack of multiple sheets, and can be reinforced so that the fixing body 4 does not bend when the anchor bolt 2 is pulled out.

[0076] Sixth Embodiment A sixth embodiment of the present invention will be described with reference to Fig. 7. Note that a description of the same parts as in the first to fifth embodiments will be omitted, and the following mainly focuses on the different parts. FIG. 7 is a vertical cross-sectional view of an anchor bolt showing the sixth embodiment.

[0077] This embodiment differs from the fifth embodiment in that a screw hole 321 is formed from the lower end surface of the attachment shaft portion 32 along the shaft core 3', the anchor shaft portion 33 is a threaded steel rod with a screw groove 33a formed on its outer peripheral surface, and the upper end of the threaded steel rod is screwed into the screw hole 321.

[0078] According to this embodiment, the length of the fixing body shaft portion 33 can be adjusted by changing the amount of screwing of the fixing body shaft portion 33 into the screw hole 321 of the attachment shaft portion 32.

[0079] Seventh Embodiment A seventh embodiment of the present invention will be described with reference to Fig. 8. Note that a description of the same parts as in the first to sixth embodiments will be omitted, and the following mainly focuses on the different parts. FIG. 8 is a side view of the anchor bolt showing the seventh embodiment.

[0080] This embodiment differs from the first embodiment in that the lower surfaces of the portions of the fixing bodies 4 at each stage that protrude outward from the fixing body shaft portion 33 are formed as tapered surfaces 42 that slope toward the lower end as they approach the axis 3'.

[0081] In this way, the underside of the protruding portion of the anchor 4 is formed as a tapered surface 42, so that concrete 1 can be easily filled between the spaced apart anchors 4, and the protruding anchoring surface portion 40 of the lower anchor 4 can be given sufficient bearing capacity to resist pull-out.

[0082] Eighth Embodiment An eighth embodiment of the present invention will be described with reference to Fig. 9. Note that a description of the same parts as in the first to seventh embodiments will be omitted, and the following mainly focuses on the different parts. FIG. 9 is a vertical cross-sectional view of an anchor bolt according to the eighth embodiment before cutting, showing the lower part and omitting the part above the attachment shank 32. In FIG.

[0083] In this embodiment, the anchor shaft portion 33 and the anchor 4 are formed by cutting a single screw-shaft-shaped deformed steel bar.

[0084] As shown by the dotted line in Figure 9, a first circular groove 50 with a depth equivalent to 1 / 2 the difference between the outer diameter d1 of the attachment shaft portion 32 and the outer diameter d2 of the anchor shaft portion 33 is formed along the outer periphery facing the lower end of the portion that will become the attachment shaft portion 32 of the screw shaft-shaped deformed steel bar, and a second circular groove 51 with the same depth as the first circular groove 50 is formed along the outer periphery at a distance below the first circular groove 50, and further, a circular notch 52 with the same depth as the first circular groove 50 and the second circular groove 51 is formed along the outer periphery at a distance below the second circular groove 51, reaching the lower end of the deformed steel bar.

[0085] As a result, the portions corresponding to the bottom surfaces of the first circular groove 50, the second circular groove 51, and the circular notch 52 become the outer peripheral surface of the fixing body shaft portion 33, and fixing bodies 4 are formed between the first circular groove 50 and the second circular groove 51, and between the second circular groove 51 and the circular notch 52. Therefore, the outer diameter d3 of the fixing body 4 and the outer diameter d1 of the attachment shaft portion 32 are the same diameter. The outer periphery of the fixing body 4 may be further machined to make the outer diameter d3 of the fixing body 4 smaller than the outer diameter d1 of the attachment shaft portion 32.

[0086] In this way, by cutting a single screw-shaft shaped deformed steel bar to form the attachment shaft portion 32, anchor shaft portion 33 and anchor 4, there is no need to join the parts together by welding, etc., making manufacturing easy. The structures of the smooth shaft portion 31 and the exposed shaft portion 34 are the same as those in the seventh embodiment.

[0087] Ninth Embodiment A ninth embodiment of the present invention will be described with reference to Fig. 10. Note that a description of the same parts as in the first to eighth embodiments will be omitted, and the following mainly focuses on the differences. FIG. 10 is a side view of the anchor bolt showing the ninth embodiment.

[0088] The ninth embodiment differs from the first embodiment in that the attachment shaft portion 32 is formed from a deformed steel bar having a plurality of longitudinal ribs 322a extending along the axial direction and a plurality of horizontal ribs 322b extending along the circumferential direction on the outer surface.

[0089] Two longitudinal ribs 322a are formed in the axial direction, one of which is shown in FIG. 10, and the other is formed on the rear side.

[0090] The horizontal ribs 322b are provided symmetrically in the X-axis direction with the vertical rib 322a as a boundary, and are formed at different positions (staggered) in the Z-axis direction.

[0091] Since the vertical ribs 322a and horizontal ribs 322b are provided on the outer peripheral surface, the attaching shaft portion 32 has sufficient adhesive strength to the concrete 1.

[0092] Tenth Embodiment A tenth embodiment of the present invention will be described with reference to Fig. 11. Note that a description of the same parts as the first to ninth embodiments will be omitted, and the following mainly focuses on the differences. FIG. 11 is a side view of an anchor bolt showing the tenth embodiment.

[0093] This embodiment is applied to an anchor bolt 2 provided horizontally as an embedded anchor embedded in concrete 1 of a structural part having a vertically exposed surface such as a wall surface. The anchor bolt 2 is the same as that according to the first embodiment.

[0094] The anchor shaft 33 is located horizontally to the right of the attachment shaft 32, i.e., on the rear side where it is installed deeper into the concrete 1 than the attachment shaft 32. The exposed shaft 34 is the part exposed from the concrete 1, and is therefore located on the pull-out side of the X-axis (left side in the drawing) of the buried attachment shaft 32, i.e., on the front side.

[0095] The fixing body 4 of the anchor bolt 2 in this embodiment has a protruding fixing surface portion 40 that faces the pull-out direction (X direction) applied horizontally to the anchor bolt 2 and resists the pull-out.

[0096] The smooth shank portion 31 is disposed between the exposed shank portion 34 and the attached shank portion 32, making it difficult for cracks to occur on the surface of the concrete 1.

[0097] [Other Modifications] The present invention is not limited to the above-described embodiment, and may also include the following, for example.

[0098] In this embodiment, the pull-out direction of the anchor bolt is perpendicular to the exposed surface of the concrete, but this is not limiting and the pull-out direction of the anchor bolt may be at a different angle from the exposed surface of the concrete. For example, the present invention may be applied to an anchor bolt that is embedded at an angle to the concrete of a horizontal exposed surface such as a foundation.

[0099] In this embodiment, the outer shape of the fixing body is circular, but it may also be angular, such as triangular, rectangular, polygonal, etc. When multiple angular fixing bodies are used stacked in the axial direction as viewed from the axial direction, the vertices of the fixing bodies may be aligned in the pull-out direction of the anchor bolt, or may be offset from each other.

[0100] In the embodiment having a plurality of fixing bodies, all fixing bodies have the same shape and size, but the fixing bodies may have different shapes and outer diameters.

[0101] The deformed steel bars used for the anchor shaft portion and the attachment shaft portion may have a shape other than that of the steel bars in the above embodiment, for example, a steel bar having diagonally intersecting protrusions formed on the outer surface.

[0102] In the present embodiment, the exposed shank 34 of the anchor bolt body 3 is such that the exposed surface of the concrete 1 or filler 11 in which the attachment shank 32 or the anchor body shank 33 is embedded is a uniform plane, and the part exposed from that plane is the exposed shank 34, but this is not limited to this. For example, as shown in Figure 12, a recess H like a box cutout is provided on the exposed surface of concrete 1, and a smooth shaft portion 31, an adhesive shaft portion 32, and an anchor shaft portion 33 are buried below the recess H, and are only exposed inside the recess H above these, are naturally included in the exposed shaft portion of the present invention.

[0103] In this embodiment, the smooth shaft portion 31 has a smooth outer circumferential surface to suppress the adhesive force of the concrete 1, and is formed by cutting the outer circumferential surface of the deformed steel bar smoothly, but this is not limiting. For example, the smooth shaft portion 31 may be further coated with a lubricant. Also, for example, a thread similar to the exposed threaded portion 34a of the exposed shaft portion 34 may be formed by extending it to near the upper end of the attached shaft portion of the buried shaft portion, and a threaded portion formed on the inner surface of a metal sleeve whose outer surface is smooth, for example, polished to a mirror finish, and whose adhesive force of concrete is suppressed, may be screwed and attached to this portion to form a smooth shaft portion.

[0104] Each technical matter in any of the embodiments may be applied to other embodiments to form examples. [Explanation of symbols]

[0105] 1. Concrete (hardening material) 2 anchor bolts 3 Anchor bolt body 3' axis 30 Buried shaft 31 Smooth shaft part 32 Attached shaft 320 protrusion 321 screw hole 322a Vertical rib 322b horizontal rib 33 Fixing body shaft 34 Exposed shaft part 4 Fixing body 40 Protruding fixing surface section 41 Female thread surface 42 Tapered surface 50 First circular groove 51 Second circular groove 52 Circular notch

Claims

1. An anchor bolt comprising an anchor bolt body having an embedded shank portion that is embedded in a hardening material and an exposed shank portion that is positioned in a pull-out direction from the embedded shank portion, The embedded shaft portion includes an attached shaft portion formed with an uneven surface and a smooth shaft portion formed with a smooth surface, The smooth shank portion is positioned between the attached shank portion and the exposed shank portion. An anchor bolt characterized by:

2. a fixing body provided on the anchor bolt body, The anchor bolt body further includes an anchor body shank located on the inner side of the attachment shank and on which the anchor body is provided, the fixing body has a protruding fixing surface portion that protrudes outward from the outer peripheral surface of the fixing body shaft portion and faces the pull-out direction of the anchor bolt to resist pull-out, The fixing body shaft portion is formed to have a smaller outer diameter than the exposed shaft portion.

2. The anchor bolt according to claim 1.

3. The protruding fixing surface portion is located within a region surrounded by a locus of the outermost periphery when the attachment shaft portion is rotated around the axis of the anchor bolt body when viewed from the pull-out direction.

3. The anchor bolt according to claim 2.

4. The protruding fixing surface portion is located within a region surrounded by a locus of the outermost periphery when the exposed shank portion is rotated around the axis of the anchor bolt body when viewed from the pull-out direction.

3. The anchor bolt according to claim 2.

5. A plurality of the fixing bodies are provided in the direction of pulling out the anchor bolt from the fixing body shaft portion. The anchor bolt according to any one of claims 2 to 4.

6. The exposed shaft portion has a threaded portion on its outer circumferential surface. The anchor bolt according to any one of claims 2 to 4.

7. An anchor bolt fixing structure in which an anchor bolt having an anchor bolt body is fixed to a hardened material, The anchor bolt body has an embedded shank portion that is embedded in the hardening material and an exposed shank portion that is positioned in a direction from which the anchor bolt is pulled out, The embedded shaft portion has an attached shaft portion formed with an uneven surface and a smooth shaft portion formed with a smooth surface, The smooth shank portion is located between the attached shank portion and the exposed shank portion and is embedded in the hardening material. An anchor bolt fixing structure characterized by the above.

8. The anchor bolt includes a fixing body provided on the anchor bolt body, The anchor bolt body further includes an anchor body shank located on the inner side of the attachment shank and on which the anchor body is provided, the fixing body has a protruding fixing surface portion that protrudes outward from the outer peripheral surface of the fixing body shaft portion and faces the pull-out direction of the anchor bolt to resist pull-out, The fixing body shaft portion is formed to have an outer diameter smaller than that of the exposed shaft portion, The fixing body shaft portion and the fixing body are embedded in the hardening material.

8. The anchor bolt fixing structure according to claim 7.

9. The protruding fixing surface portion is located within a region surrounded by a trajectory of the outermost periphery when the attachment shaft portion is rotated around the axis of the anchor bolt body as viewed from the pull-out direction, and is embedded in the hardening material.

9. The anchor bolt fixing structure according to claim 8.

10. The protruding fixing surface portion is located within a region surrounded by a trajectory of the outermost periphery when the exposed shank portion is rotated around the axis of the anchor bolt body as viewed from the pull-out direction, and is embedded in the hardening material.

9. The anchor bolt fixing structure according to claim 8.

11. A plurality of the fixing bodies are provided in the direction of pulling out the anchor bolt from the fixing body shaft portion. The anchor bolt fixing structure according to any one of claims 8 to 10.

12. The exposed shaft portion has a threaded portion on its outer circumferential surface. The anchor bolt fixing structure according to any one of claims 8 to 10.

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