Post-construction anchor

Abstract

To prevent an inner member from entering into a sleeve more than necessary, and ensure high fixing force.SOLUTION: A post-construction anchor 1 comprises: an inner member 2 having a tapered surface 22 that gradually expands toward a tip on an outer circumference of a tip side of a cylindrical base 21, and a female thread hole 23 into which a mounting bolt 4 is screwed and which is internally provided so as to open backward; and a substantially cylindrical sleeve 3 having an expansion piece 32 formed on a tip side of a cylindrical portion 31, which expands by riding up on the tapered surface 22. A position regulating portion 35 is provided on an inner side of the sleeve 31 that is in contact with the inner member 2 and regulates the amount of entry of the inner member 2 at a position where a part of the tapered surface 22 of the inner member 2 is exposed on the tip side more than the expansion piece 32.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a post-installed anchor that is drilled into existing concrete and driven into the concrete. [Background technology]

[0002] A post-installed anchor 200 is known as a post-installed anchor that is drilled into existing concrete and driven into the concrete. The post-installed anchor 200 comprises an inner member 201 having a tapered surface 203 formed on the outer periphery of the tip side of a tubular base 202 that gradually expands in diameter toward the tip, and an internally provided female threaded hole 204 into which a mounting bolt is screwed that opens to the rear, and a substantially tubular sleeve 205 having an expansion piece 206 formed on the tip side, and the tubular base 202 of the inner member 201 is inserted into the tip side of the sleeve 205 and assembled in a non-expanded state (see Patent Documents 1 and 2, FIG. 7).

[0003] This unexpanded post-installed anchor 200 is inserted into a borehole 301 in concrete 300 with the inner member 201 facing towards the back of the hole, and by driving the sleeve 205 into the back of the hole, the tapered surface 203 of the inner member 201 is caused to fit relatively into the expansion piece 206 of the sleeve 205, expanding the expansion piece 206, which then bites into the wall of the borehole 301 and is fixed in place.

[0004] After the anchor 200 is fixed, a mounting bolt 302 is screwed into the female threaded hole 204 of the inner member 201. Then, an attachment 303 is fitted onto the mounting bolt 302 screwed into the inner member 201, a washer 304 is fitted onto the mounting bolt 302 on the outside of the attachment 303, and a mounting nut 305 is screwed onto the mounting bolt 302, so that the attachment 303 is attached to the concrete 300. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2018-3503 A [Patent Document 2] JP 2020-148045 A Summary of the Invention [Problem to be solved by the invention]

[0006] Incidentally, in a post-installed anchor 200 such as those disclosed in Patent Documents 1 and 2, when a tensile force is applied to the mounting bolt 302 by tightening the mounting nut 305, the inner member 201 bites deeper into the inside of the sleeve 205, and this biting increases the amount of expansion of the expansion piece 206 of the sleeve 205, resulting in a follow-up expansion effect and providing greater fixing power.

[0007] However, as shown in Figure 7, if the inner member 201 bites too deeply into the inside of the sleeve 205, the entire tapered surface 203 of the inner member 201, in other words the entire inner member 201, will penetrate into the inside of the sleeve 205, which will result in a problem that the amount of expansion of the expansion piece 206 of the sleeve 205 will be reduced, thereby reducing the fixing strength of the post-installed anchor 200.

[0008] In addition, in a configuration in which a female thread 207 is formed on the inner surface of the sleeve 205 of the post-installed anchor 200 near the rear, and an extraction attachment is screwed into the female thread 207 of the sleeve 205 to easily extract the sleeve 205 when the post-installed anchor 200 is no longer needed, it is necessary for the expansion piece 206 of the sleeve 205 to be expanded and fixed so as to gradually expand in diameter toward the tip in order to smoothly extract the sleeve 205 when it is no longer needed, however, as shown in Fig. 7, if the entire tapered surface 203 of the inner member 201, in other words the entire inner member 201, enters the inside of the sleeve 205, deformation occurs in which the tip 2061 of the expansion piece 206 is bent inward, and the inwardly bent tip 2061 of the expansion piece 206 gets caught on the inner member 201 during the extraction operation of the sleeve 205, making it impossible to extract the sleeve 205.

[0009] The present invention has been proposed in view of the above problems, and has an object to provide a post-installed anchor that can prevent the inner member from entering the sleeve more than necessary and can reliably exert a high fixing force. Another object of the present invention is to provide a post-installed anchor that can prevent the expansion piece of the sleeve from bending inward in a structure that makes it easy to pull out the sleeve by utilizing the female thread on the inner surface of the sleeve, and can easily and reliably pull out and remove the sleeve smoothly. [Means for solving the problem]

[0010] The post-installed anchor of the present invention comprises an inner member having a tapered surface formed on the outer periphery of the tip side of a tubular base that gradually expands in diameter towards the tip, and an internally-installed female threaded hole into which a mounting bolt is screwed that opens to the rear, and a roughly cylindrical sleeve having an expansion piece formed on the tip side of the tubular portion that expands by riding up on the tapered surface, and is characterized in that a position regulating portion is provided on the inside of the tubular portion that abuts against the inner member and regulates the amount of insertion of the inner member at a position where a portion of the tapered surface of the inner member is exposed further towards the tip than the expansion piece. According to this, the abutment of the position regulating portion provided on the inside of the tubular portion of the sleeve with the inner member regulates the amount of penetration of the inner member into the sleeve so that a part of the tapered surface of the inner member is exposed on the tip side beyond the expansion piece, so that a fixed state in which the expansion piece of the sleeve gradually expands in diameter toward the tip can be secured. In other words, it is possible to prevent the inner member from penetrating into the sleeve more than necessary, and the high fixing power of the post-installed anchor can be reliably exhibited.

[0011] The post-installed anchor of the present invention is characterized in that a female thread is formed on the inside of the tubular portion and has a larger diameter than the female threaded hole of the inner member, into which an extraction attachment is screwed. This ensures an expanded state in which the expansion piece of the sleeve gradually expands in diameter toward the tip, and prevents the expansion piece of the sleeve from bending inward.Therefore, in a structure in which an extraction attachment is screwed into the female thread on the inner surface of the sleeve to make it easy to pull out the sleeve, the sleeve can be easily and reliably pulled out and removed smoothly. Effect of the Invention

[0012] According to the post-installed anchor of the present invention, it is possible to prevent the inner member from penetrating into the sleeve more than necessary, and the post-installed anchor can reliably exhibit high fixing strength. [Brief description of the drawings]

[0013] [Figure 1] FIG. 2A is a front view of a post-installed anchor according to an embodiment of the present invention, and FIG. 2B is a side view of the post-installed anchor in FIG. 2A as viewed from the inner member side. [Diagram 2] FIG. 2A is a front view of an embodiment of a post-installed anchor in an expanded state, and FIG. 2B is a side view of the post-installed anchor of FIG. 2A as viewed from the inner member side. [Diagram 3] 1A is a front view of a sleeve of a post-installed anchor according to an embodiment, and FIG. 1B is a front view of an inner member of the post-installed anchor according to an embodiment. [Figure 4] 1A is a longitudinal cross-sectional view of a sleeve of a post-installed anchor according to an embodiment, and FIG. 1B is a longitudinal cross-sectional view of an inner member of the post-installed anchor according to an embodiment. [Diagram 5] 1A is a longitudinal cross-sectional view of a post-installed anchor of an embodiment in a state where it is inserted into a drilled hole, and FIG. 1B is a longitudinal cross-sectional view of an expansion piece of the post-installed anchor of an embodiment in a state where it is expanded in the drilled hole. [Figure 6] FIG. 1A is a longitudinal section view illustrating the fixed state of the post-installed anchor of the embodiment after the expansion piece is expanded by drilling a hole, FIG. 1B is a longitudinal section view illustrating the fixed state of the post-installed anchor of the embodiment after a mounting bolt and a mounting nut are installed, and FIG. 1C is a longitudinal section view illustrating the fixed state of the post-installed anchor of the embodiment when a force in the pull-out direction is applied to the post-installed anchor. [Figure 7]FIG. 1 is an explanatory diagram for explaining problems with conventional post-installed anchors. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] [Post-installed anchor according to embodiment] As shown in Figures 1 to 4, a post-installed anchor 1 according to an embodiment of the present invention comprises an inner member 2 having a tubular base 21 on the outer periphery at the tip side thereof with a tapered surface 22 that gradually expands in diameter towards the tip, and an internally provided female threaded hole 23 into which a mounting bolt 4 is screwed so as to open to the rear, and a substantially cylindrical sleeve 3 having an expansion piece 32 formed on the tip side of the tubular portion 31 which expands by riding on the tapered surface 22 of the inner member 2.

[0015] In this embodiment, the female threaded hole 23 of the inner member 2 is formed as a bottomed hole, and opens rearward at the rear end face 24. In this embodiment, the female threaded hole 23 in the vicinity of the rear end face 24 is not formed with a female thread, and the female threaded hole 23 in the vicinity of the rear end face 24 is formed with a larger inner diameter than the part where the female thread is formed, making it easier to introduce and screw the mounting bolt 4 described below into the female threaded hole 23. The female thread of the female threaded hole 23 is capable of screwing in a male thread 41 formed on the outer periphery of the mounting bolt 4.

[0016] In this embodiment, the tubular base 21 of the inner member 2 has an outer periphery formed into a cylindrical surface, and its outer diameter is formed to be approximately the same as or slightly smaller than the inner diameter of the expansion piece 32 in the unexpanded state. The post-installed anchor 1 in the unexpanded state is assembled by inserting the tubular base 21 of the inner member 2 into the expansion piece 32 on the tip side of the sleeve 3, and is arranged so that approximately the entire tapered surface 22 of the inner member 2 is exposed beyond the tip of the expansion piece 32 of the sleeve 3. When the expansion piece 32 is expanded, the sleeve 3 is driven toward the tip of the inner member 2, causing the tapered surface 22 to enter the expansion piece 32 and expanding the expansion piece 32 (see Figure 2).

[0017] The sleeve 3 is provided with extension pieces 32, divided by slits 33 cut in the axial direction from the tip, and in the illustrated example, the slits 33 are formed at four locations in the circumferential direction, and four extension pieces 32 are provided in the circumferential direction. In this embodiment, a female thread 34 is formed on the inside of the tubular portion 31 of the sleeve 3. The female thread 34 is formed with a larger diameter than the female threaded hole 23 of the inner member 2, so that an extraction attachment with a larger diameter than the mounting bolt 4 can be screwed into it, and the mounting bolt 4 can be freely inserted into the hole formed by the female thread 34.

[0018] A position restricting portion 35 is provided inside the tubular portion 31 of the sleeve 3 to abut against the inner member 2 and restrict the amount of insertion of the inner member 2 at a position where part of the tapered surface 22 of the inner member 2 is exposed further toward the tip side than the expansion piece 32. The position restricting portion 35 in this embodiment is a circumferential stepped surface 351 formed so as to protrude inward at the front part of the inside of the tubular portion 31, and the rear end surface 24 of the inner member 2 abuts against this circumferential stepped surface 351 to restrict the amount of insertion of the inner member 2 when the post-installed anchor 1 is expanded. The female thread 34 of the sleeve 3 is formed on the rear side of the circumferential stepped surface 351.

[0019] When the post-installed anchor 1 of the embodiment is installed in concrete 100 to attach an object 110, as shown in Fig. 5(a), a bore hole 101 is formed in the concrete 100, the bore hole 101 is cleaned, and the post-installed anchor 1 in a non-expanded state is inserted into the bore hole 101 with the inner member 2 at the back of the hole. Next, as shown in Fig. 5(b), a driving rod is brought into contact with the rear end surface of the sleeve 3, and the sleeve 3 is driven into the back of the hole by driving the driving rod, etc., so that the tapered surface 22 of the inner member 2 is relatively inserted inside the expansion piece 32 of the sleeve 3 to expand the expansion piece 32, and the expansion piece 32 is caused to bite into the wall of the bore hole 101. In the post-installed anchor 1 in an expanded state, the expanded expansion piece 32 is expanded as shown by the arrow in Fig. 6(a) and bites into the peripheral wall of the bore hole 101 so as to press it outward, and is fixed in the bore hole 101.

[0020] 6(b), the mounting bolt 4, which is a fully threaded bolt with a male thread 41 formed on the outer periphery over its entire length, is inserted into the hole of the female thread 34 and screwed into the female threaded hole 23 of the inner member 2, and the attachment 110 is fitted onto the mounting bolt 4 screwed into the inner member 2. Furthermore, a washer 5 is fitted onto the mounting bolt 4 outside the attachment 110, and a mounting nut 6 is screwed onto the mounting bolt 4.

[0021] By tightening the mounting nut 6 onto the mounting bolt 4, the tapered surface 22 of the inner member 2 is pulled toward the opening of the borehole 101, and the expansion piece 32 of the sleeve 3 is expanded accordingly. The expanded expansion piece 32 bites into the peripheral wall of the borehole 101 so as to press it more strongly outward (see FIG. 6(b)), and the post-installed anchor 1 is fixed in the borehole 101 with greater strength.

[0022] After the mounting bolt 4 has been screwed in and fixed in this manner, if a force is applied to the installation anchor 1 in the direction in which the mounting bolt 4 is pulled out, as shown in Figure 6(c), the position regulating portion 35 or circumferential step surface 351 of the sleeve 3 abuts against the inner member 2 which moves in the direction in which the mounting bolt 4 is pulled out, and regulates the amount of insertion of the inner member 2 to a position where part of the tapered surface 22 of the inner member 2 is exposed further toward the tip side than the expansion piece 32.

[0023] When the inner member 2 enters the sleeve 3 with the amount of entry of the inner member 2 restricted by the position restricting portion 35, the expansion piece 32 of the sleeve 3 stably expands further accordingly, and the expanded expansion piece 32 bites into the peripheral wall of the borehole 101 so as to press it even more strongly outward (see FIG. 6(c)), and the post-installed anchor 1 is fixed with even greater strength in the borehole 101. Furthermore, when it is no longer necessary to install the post-installed anchor 1 in the concrete 100, the male thread of the extraction attachment is screwed into the female thread 34 of the sleeve 3, and the sleeve 3 is pulled out and removed.

[0024] According to the post-installed anchor 1 of this embodiment, the amount of penetration of the inner member 2 into the sleeve 3 is restricted so that part of the tapered surface 22 of the inner member 2 is exposed further toward the tip than the expansion piece 32 due to the abutment of the position regulating portion 35 or the circumferential step surface 351 provided on the inside of the tubular portion 31 of the sleeve 3 with the inner member 2, thereby ensuring a fixed state in which the expansion piece 32 of the sleeve 3 is gradually enlarged in diameter toward the tip. In other words, it is possible to prevent the inner member 2 from penetrating into the sleeve 3 more than necessary, and the post-installed anchor 1 can reliably exert its high fixing power.

[0025] In addition, since an expanded state is ensured in which the expansion piece 32 of the sleeve 3 gradually expands in diameter toward the tip, and deformation of the expansion piece 32 of the sleeve 3 by bending inward can be prevented, in a structure in which an extraction attachment is screwed into the female thread 34 on the inner surface of the sleeve to facilitate extraction of the sleeve 3, the sleeve 3 can be easily and reliably pulled out and removed smoothly.

[0026] [Scope of the invention disclosed herein] The inventions disclosed in this specification include, in addition to the inventions and embodiments listed as inventions, those specified by changing partial contents of these to other contents disclosed in this specification, those specified by adding other contents disclosed in this specification to these contents, or those specified by deleting partial contents of these to the extent that partial effects can be obtained, and specifying them as a higher-level concept. The inventions disclosed in this specification also include the following contents and modifications.

[0027] For example, in the post-installed anchor 1 of the above embodiment, a female thread 34 is formed on the inside of the tubular portion 31 of the sleeve 3 so that when the post-installed anchor 1 is no longer needed, an extraction attachment can be screwed onto it to pull out the sleeve 3, but the sleeve of the post-installed anchor of the present invention may be any suitable sleeve having an approximately cylindrical shape with an expansion piece formed on the tip side of the tubular portion and provided with a position regulating portion, and it is also possible to use a sleeve that does not have a female thread 34 formed thereon.

[0028] Furthermore, although the female threaded hole 23 of the inner member 2 of the post-installed anchor 1 in the above embodiment is a bottomed hole, the female threaded hole 23 may be provided so as to penetrate axially all the way to the tip of the inner member 2, in which case the length along which the female threads are formed in the female threaded hole 23 may be any length within a range that satisfies the length of thread engagement with the mounting bolt 4.

[0029] Furthermore, the position regulating portion in the sleeve of the post-installed anchor of the present invention is not limited to the circumferential step surface 351 of the above embodiment but may be any appropriate portion within the scope of the spirit of the present invention, and may be, for example, the inner end portion of the front end face of the tubular portion 31 which abuts against the inner member 2 near the boundary between the tubular base portion 21 and the tapered surface 22 of the inner member 2. [Industrial Applicability]

[0030] The present invention can be used as a post-installed anchor that is driven into a hole in existing concrete. [Explanation of symbols]

[0031] 1...Post-installed anchor 2...Inner member 21...Cylindrical base 22...Tapered surface 23...Female thread hole 24...Rear end surface 3...Sleeve 31...Cylindrical portion 32...Expansion piece 33...Slit 34...Female thread 35...Position control portion 351...Circumferential step surface 4...Mounting bolt 41...Male thread 5...Washer 6...Mounting nut 100...Concrete 101...Drilling hole 110...Attachment 200...Post-installed anchor 201...Inner member 202...Cylindrical base 203...Tapered surface 204...Female thread hole 205...Sleeve 206...Expansion piece 2061...Tip 207...Female thread 300...Concrete 301...Drilling hole 302...Mounting bolt 303...Attachment 304...Washer 305...Mounting nut

Claims

1. an inner member having a tapered surface formed on the outer periphery of the tip side of the cylindrical base, the diameter of which gradually increases toward the tip, and an internal threaded hole into which a mounting bolt is screwed, the internal threaded hole being disposed so as to open rearward; A generally cylindrical sleeve having an expansion piece formed on a tip side of a cylindrical portion, the expansion piece expanding by riding on the tapered surface, a position regulating portion provided on the inside of the tubular portion for restricting the amount of insertion of the inner member at a position where the tapered surface of the inner member abuts against the inner member and is exposed toward the tip side beyond the expansion piece.

2. 2. The post-installed anchor according to claim 1, wherein the inside of the cylindrical portion is formed with a female thread having a diameter larger than that of the female threaded hole of the inner member, into which an extraction attachment is screwed.

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