JP4590802B2 - Embedded hook - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an embedding hook suitable for embedding in a concrete structure.
[0002]
[Prior art]
As an embedded hook, Japanese Utility Model Laid-Open No. 58-63418 discloses a rod-shaped embedded portion embedded in a concrete structure and a hook portion exposed from the concrete structure, and an outer peripheral surface of the embedded portion. A plurality of vertical ribs extending in the generatrix direction and a plurality of horizontal ribs connecting adjacent vertical ribs are formed by die forging, and the embedded portion is used for locking and retaining perpendicular to the axis thereof. An embedded hook is described which is formed by penetrating the shank muscles and fixed. The vertical ribs and the horizontal ribs are formed in a substantially semicircular or trapezoidal cross section.
[0003]
However, in this embedded hook, although the vertical rib and the horizontal rib are formed in the embedded portion, the maximum outer diameter of all the horizontal ribs is the same size, so the bonding strength between the embedded portion and the concrete structure in the drawing direction is sufficient. It was difficult to ensure.
[0004]
Therefore, as described in Japanese Patent Application Laid-Open No. 7-310728, the embedded portion is configured with a tapered shaft having a diameter reduced toward the engaging portion so that the pulling strength of the embedded hook with respect to the structure can be further improved. The one configured in this way has also been proposed.
[0005]
[Problems to be solved by the invention]
In the embedded hook described in the latter publication, since the embedded portion is configured with a taper shaft, the pulling strength of the embedded hook with respect to the structure can be improved, but the manufacturing cost of the embedded hook is increased.
Further, in the embedded hooks described in the above-mentioned publications, since the through hole of the embedded portion through which the shank muscle is inserted is formed by a drill, the thickness of the embedded portion in the mounting portion of the hairpin is thin by the amount corresponding to the through hole. Therefore, when a large external force is applied to the embedded hook, there is a concern that the attachment portion of the shank muscle breaks and the embedded hook falls off.
[0006]
An object of the present invention is to provide an embedded hook that can improve the pull-out strength while suppressing an increase in manufacturing cost.
[0007]
[Means for Solving the Problem and Action]
An embedded hook according to the present invention has an embedded portion embedded in a structure, and a hook portion that extends integrally from the embedded portion and protrudes outside the structure, and is circumferentially provided on the peripheral surface of the embedded portion. A plurality of lateral ribs for retaining the extension are formed to protrude in the axial direction at intervals, and an engagement surface substantially orthogonal to the shaft center of the embedded portion is formed on the side surface of the lateral rib on the hook portion side. The shape is formed so as to become thinner as the distance from the engagement surface increases in the cross section perpendicular to the longitudinal direction of the lateral rib.
[0008]
In this embedded hook, an engagement surface that is substantially perpendicular to the shaft center of the embedded portion is formed on the side surface of the lateral rib on the hook portion side, and the load in the pulling direction of the embedded hook is applied to the structure through this engagement surface. Therefore, the shearing force between the engaging surface of the lateral rib and the engaging portion with respect to the lateral rib of the structure is reduced as much as possible to prevent the engaging portion from being damaged, and the pull-out strength of the embedded hook can be improved. In addition, since the shape of the lateral rib is formed to become thinner as the distance from the engagement surface in the cross section orthogonal to the longitudinal direction of the lateral rib, the base end of the engagement portion is formed while forming the engagement surface as described above. By sufficiently securing the width of the portion, it is possible to effectively prevent breakage of the engaging portion and improve the pull-out strength of the embedded hook.
[0009]
Here, it is preferable that a plurality of longitudinal ribs extending in the axial direction are formed on the circumferential surface of the embedded portion so as to protrude in the circumferential direction. In this case, the torsional load acting on the embedded hook can be received by the vertical rib, and the mounting strength of the embedded hook to the structure can be improved.
[0010]
A through-hole extending in the direction perpendicular to the axis may be formed in the embedded portion, and a knurled bar for preventing rotation and retaining may be attached to the through-hole. In this case, the mounting strength against the load in the pulling direction and torsional direction of the embedded hook with respect to the structure can be remarkably improved by the knurled bar.
[0011]
In this case, the through hole is preferably formed by forging. If comprised in this way, compared with the case where a through-hole is formed with a drill, the intensity | strength of the embed | buried part in the mounting part of a pinch muscle can be improved markedly.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
As shown in FIGS. 1 and 2, the embedded hook 10 is integrally extended from the embedded portion 11 and an embedded portion 11 embedded in a wall portion, a pillar, a floor, a ceiling, or the like when the concrete structure 1 is applied. And a hook portion 12 that protrudes outside the structure 1 and is integrally formed by die forging a metal rod-shaped member. A through-hole 13 extending in a direction orthogonal to the axis is formed at one end of the embedded portion 11, and a rod-shaped barb bar 14 is attached to the through-hole 13, and the barb bar 14 is embedded in the concrete structure 1 together with the embedded unit 11. By doing so, the pull-out strength and the torsional strength of the embedded hook 10 with respect to the concrete structure 1 are increased.
[0013]
The embedded portion 11 is formed in a substantially straight shape, and a plurality of annular retaining ribs 15 that are circumferentially extended are formed on the peripheral surface of the embedded portion 11 at intervals in the axial direction. A plurality of straight vertical ribs 16 are formed at intervals in the circumferential direction.
[0014]
As shown in FIGS. 1 and 3A, an engagement surface 17 that is substantially perpendicular to the axis of the embedded portion 11 is formed on the side surface of the lateral rib 15 on the hook portion 12 side, and the lateral rib 15 is substantially perpendicular to the cross section. It is formed in a triangular shape, and its thickness is made thinner as it gets away from the engagement surface 17. The diameter D of the embedded portion 11 is set to 10 to 100 mm, and the width W1 of the lateral rib 15 is set to 10 to 50% of the diameter D of the embedded portion 11 in consideration of the formability and strength of the lateral rib 15. Yes. The maximum thickness T1 of the horizontal rib 15 is set to 3.0 to 20% of the diameter D of the embedded portion 11 in order to sufficiently secure the engagement surface 17 while ensuring the formability of the horizontal rib 15 by die forging. The arrangement pitch P of the lateral ribs 15 can be arbitrarily set. However, the strength of the structure 1 with respect to the load in the drawing direction is sufficiently secured, and the number of the lateral ribs 15 formed in the embedded portion 11 is increased as much as possible. In order to increase the contact area between the buried portion 11 and the concrete structure 1 as much as possible, it is set to 40 to 80% of the diameter D of the buried portion. The oblique side 18 of the lateral rib 15 may be formed in a substantially straight shape, or may be formed in a curved shape recessed toward the axial center, a curved shape bulged outward, or the like. Further, the lateral rib 15 can be formed to be inclined with respect to the axial direction of the embedded portion 11, and may be arranged with a phase shifted in the axial direction of the embedded portion 11 with the vertical rib 16 as a boundary. .
[0015]
As shown in FIG. 4, the cross-sectional shape of the vertical ribs 16 is formed in a substantially semicircular shape as in the conventional case, and the number thereof can be arbitrarily set according to the diameter of the embedded portion 11 and the like. Since the contact area between the lateral rib 15 and the structure 1 decreases as the number increases, it is preferably set to 2 to 4. The width W2 of the vertical rib 16 is set to 10 to 50% of the diameter of the embedded portion 11 in the same manner as the horizontal rib 15 in consideration of the moldability and strength of the vertical rib 16, and the maximum thickness T2 of the vertical rib 16 is Similar to the lateral ribs 15, it is set to 3.0 to 20% of the diameter D of the embedded portion 11.
[0016]
As shown in FIG. 3A and FIG. 4, a substantially rectangular concave portion 19 is formed by a lateral rib 15 and a longitudinal rib 16 on the surface of the embedded portion 11, and the embedded portion 11 is embedded in the concrete structure 1. In this state, the engaging portion 2 of the concrete structure 1 that engages with the lateral rib 15 and the longitudinal rib 16 is formed in the recess 19. The load in the pulling direction of the embedded hook 10 is received by the engagement of the lateral rib 15 and the engaging portion 2, and the twisting direction of the embedded hook 10 is received by the engagement of the vertical rib 16 and the engaging portion 2. The load of is accepted. In addition, since the load in the pulling direction is received by the engaging portion 2 via the engaging surface 17 orthogonal to the axis of the embedded portion 11, the engagement surface 17 of the lateral rib 15 and the concrete structure 1 are engaged. The shearing force between the portions 2 can be reduced as much as possible to prevent the engagement portion 2 from being damaged, and the pulling strength of the embedded hook 10 with respect to the concrete structure 1 can be improved. Further, since the cross-sectional shape of the lateral rib 15 is made thinner as the distance from the engaging surface 17 increases, the width W of the base portion of the engaging portion 2 is sufficiently increased as compared with the case where the lateral rib 15 is formed in a rectangular shape. It can be secured.
[0017]
FIG. 3B is a longitudinal sectional view of a conventional embedded hook 100. The lateral rib 101 is formed in the embedded portion 102 in an annular shape at regular intervals in the axial direction, and the cross section is formed in a substantially semicircular shape. Yes. For this reason, the load in the pulling direction of the embedded hook 100 acts obliquely on the engaging portion 105 of the concrete structure 104 via the arc-shaped engaging surface 103 on the pulling side of the lateral rib 101, and the engaging surface 103. A shearing force acts between the engaging portion 105 and the engaging portion 105 is easily damaged. On the other hand, in the embedded hook 10 according to the present invention, as shown in FIG. 3A, the engaging surface 17 of the lateral rib 15 is formed so as to be substantially orthogonal to the axis of the embedded portion 11. The shearing force between the engaging surface 17 and the engaging portion 2 can be reduced as much as possible to prevent the engaging portion 2 from being damaged, and the pull-out strength of the embedded hook 10 with respect to the concrete structure 1 can be improved.
[0018]
As shown in FIGS. 1 and 2, the hook portion 12 has a well-known configuration formed in a fishhook shape. A drop-off restricting member 21 is supported at the base portion of the hook portion 12 via a pin member 20 so as to be rotatable between a restricting position shown by a solid line and an open position shown by an imaginary line, and a spring member (not shown) is supported. If the detachment restricting member 21 is not operated to the open position side against the urging force of the spring member, the object to be locked such as a chain or a rope hooked on the hook portion 12 (illustrated) Is omitted from the hook portion 12. However, the drop-out restricting member 21 can be omitted.
[0019]
A disc-shaped flat portion 25 is formed by die forging together with the lateral ribs 15 and the vertical ribs 16 near the end portion of the embedded portion 11, and the flat portion 25 is thinner than the flat portion 25. The thin-walled portion (for example, about 3 mm thick) is formed, and the through-hole 13 is formed by punching out the thin-walled portion. Thus, when the through-hole 13 is formed by die forging, the load in the drawing direction and the twisting direction is received by the engagement between the portion of the flat portion 25 that protrudes outward from the embedded portion 11 and the concrete structure 1. Is possible. In addition, the through hole 13 can be formed by a drill, but when formed by die forging, compared with the case of forming by a drill, the thickness reduction when forming the through hole 13 is reduced. The strength reduction of the embedded portion 11 near the through hole 13 can be suppressed.
[0020]
Here, another embodiment of the embedded hook 10 will be described. The same members as those in the above embodiment may be denoted by the same reference numerals and detailed description thereof may be omitted.
As shown in FIGS. 5 and 6, the embedded hook 30 of this embodiment is formed by molding a metal rod-like member into a substantially U shape, and the embedded hook 30 is connected to the embedded hook 10 at both ends. Similarly, embedded portions 11 each having a horizontal rib 15, a vertical rib 16, a recessed portion 19, and a flat portion 25 are provided, and a substantially U-shaped hook extending continuously from both embedded portions 11 is provided in the middle of the embedded hook 30. A portion 31 is formed.
[0021]
Although not shown in the drawings, the side surface of the horizontal rib 15 on the side of the hook portion 31 is formed with an engagement surface 17 that is substantially orthogonal to the axis of the embedded portion 11. It is formed in a right triangle shape, and its thickness is made thinner as it gets away from the engagement surface 17. Further, a flat portion 25 is formed in the vicinity of the end portion of the embedded portion 11, the through hole 13 is formed by die forging similarly to the above embodiment, and a knurled bar 14 is attached to the through hole 13. However, the through hole 13 may be formed directly by a drill with respect to the embedded portion 11 without providing the flat portion 25.
[0022]
In the present embodiment, the embedded portion 11 is formed in a substantially straight shape, but it may be used that is bent in an L shape or the like, and a plurality of metal rod-like members such as plant roots may be used. You may use what was radially welded. Moreover, as hook parts 12 and 31, things other than the shape shown in figure can also be employ | adopted.
[0023]
【The invention's effect】
According to the embedded hook of the present invention, an engagement surface that is substantially orthogonal to the shaft center of the embedded portion is formed on the side surface of the lateral rib on the hook portion side, and a load in the pulling direction of the embedded hook is passed through this engagement surface. Therefore, the shearing force between the engaging surface of the lateral rib and the engaging portion of the structure with respect to the lateral rib can be reduced as much as possible to prevent the engaging portion from being damaged, and the pull-out strength of the embedded hook can be improved. . In addition, since the shape of the lateral rib is formed to become thinner as the distance from the engagement surface in the cross section orthogonal to the longitudinal direction of the lateral rib, the base end of the engagement portion is formed while forming the engagement surface as described above. By sufficiently securing the width of the portion, it is possible to effectively prevent breakage of the engaging portion and improve the pull-out strength of the embedded hook.
[0024]
Here, when a plurality of longitudinal ribs extending in the axial direction are formed on the peripheral surface of the embedded portion with a circumferential interval, the torsional load acting on the embedded hook can be received by the vertical rib, and the embedded hook for the structure The mounting strength can be improved.
[0025]
When a through-hole extending in the direction perpendicular to the axial center is formed in the embedded portion and a knurled bar for locking and retaining is attached to this through-hole, the knurled bar moves the embedded hook to the structure in the pull-out direction and torsional direction. The mounting strength against the load can be greatly improved.
[0026]
Further, in this case, by forming the through hole by forging, the strength of the embedded portion in the shank muscle mounting portion can be significantly improved as compared with the case where the through hole is formed by a drill.
[Brief description of the drawings]
[Fig. 1] Longitudinal sectional view of an embedded hook in a concrete structure [Fig. 2] (a) is a plan view, (b) is a front view of the embedded hook [Fig. 3] (a) is III-III in Fig. 1 Fig. 4B is a cross-sectional view taken along the line IV-IV in Fig. 1; Fig. 5 is another embodiment. FIG. 6 is a view corresponding to FIG. 1 of the embedded hook according to the example. FIG. 6A is a plan view and FIG. 6B is a front view of the embedded hook.
DESCRIPTION OF SYMBOLS 1 Concrete structure 2 Engagement part 10 Embedment hook 11 Embedment part 12 Hook part 13 Through-hole 14 Hairpin 15 Horizontal rib 16 Vertical rib 17 Engagement surface 18 Oblique side 19 Recess 20 Pin member 21 Drop-off restriction member 25 Flat part 30 Embedded hook 31 Hook part

Claims (4)

Having a buried portion embedded in the structure and a hook portion extending integrally from the buried portion and projecting outside the structure;
A plurality of retaining lateral ribs extending in the circumferential direction are formed on the circumferential surface of the buried portion so as to protrude in the axial direction, and the side ribs on the side of the hook portion of the lateral rib are substantially orthogonal to the shaft center of the buried portion. An engagement surface was formed, and the shape of the lateral rib was formed to be thinner as it was away from the engagement surface in a cross section perpendicular to the longitudinal direction of the lateral rib.
An embedded hook characterized by that. The embedded hook according to claim 1, wherein a plurality of longitudinal ribs extending in the axial direction are formed on the peripheral surface of the embedded portion so as to protrude in the circumferential direction. The embedded hook according to claim 1 or 2, wherein a through hole extending in a direction orthogonal to the axis is formed in the embedded portion, and a knurled bar for rotation and retention can be attached to the through hole. The embedded hook according to claim 3, wherein the through hole is formed by forging.

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