JP2009114729A - Threaded reinforcement anchor plate and anchoring structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a threaded reinforcement anchor plate which can be manually fastened, is proof against backlash, dispenses with a reinforcement marking step, allows the operator to check abnormality such as foreign matter and a screwing location, and accommodates defective end face shape at a distal end of a threaded reinforcement to a certain degree, and to provide a threaded reinforcement anchoring structure. <P>SOLUTION: According to the structure of the threaded reinforcement anchor plate, a range from an exit 6 of a through threaded hole 4 into which a steady female thread section 2 screwable onto a male thread of the threaded reinforcement, is penetrated, to a location inside the exit by 0.5 to 5 pitches, is set as a non-steady female thread section 3 where a female thread trough width w becomes smaller at a location closer to the exit 6 such that out of two trough surfaces opposed to each other in a female thread trough, strict lead angles (θ<SB>1</SB>, θ<SB>2</SB>) in A side trough surfaces 7 to which a tensile load of the reinforcement is applied, are set to steady values but strict lead angles (θ<SB>3</SB>, θ<SB>4</SB>) in the other B side trough surfaces 8 are set to smaller values. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fixing plate and fixing structure for screw rebar, and more particularly to a fixing plate and fixing structure used for fixing screw reinforcing bars in a reinforced concrete structure. The screw rebar is also referred to as a screw joint, and the fixing plate is also referred to as a screw fixing plate or a fixing hardware. The fixing plate according to the present invention uses a beam main bar and a column main bar fixing part, a wall main bar fixing part, a small beam main bar and a slab bar fixing part as a use site.

As a fixing plate for fixing main bar intermediates, a screw penetration type fixing plate in which a through screw is formed (see, for example, Patent Document 1 or 2) is known. Moreover, a bag screw type fixing plate (see, for example, Patent Document 1 or 3) in which a non-penetrating screw (bag screw) is formed is known as a fixing plate for fixing the main muscle end portion.
As shown in FIG. 1, the screw penetration type fixing plate (screw fixing plate 204) described in Patent Document 1 has a disk-like fixing plate portion 205 and a hexagonal columnar screw portion 206 at the center of one side surface thereof. A screw hole 207 for wearing a main muscle pivot that penetrates the fixing plate portion 205 and the screw portion 206 in the axial direction is provided. Further, a filler injection port 208 communicating with the screw hole 207 is formed in one circumferential side surface of the screw portion 206. A threaded reinforcing bar is used as the beam main bar 201, and the threaded portion 206 of the screw fixing plate 204 is screwed into and penetrates the beam main bar 201, and a high-strength non-shrink mortar 209 is inserted into the threaded portion 206 and the beam main bar 201 from the filler inlet 208. It is injected between and fixed.

In Patent Document 2, as shown in FIG. 2, if a female screw tube 112 provided with an end bulging portion 112 ′ having an appropriate length is screwed into an end portion of a reinforcing bar 111, a tensile force in the reinforcing bar direction is obtained. In contrast, it can be used as a concrete anchor having a large pulling strength, and this female screw 112 is considered to be a basic screw penetration type fixing plate.
As shown in FIG. 3, the cap screw type fixing plate (screw fixing plate 210) described in Patent Document 1 has a disk-shaped fixing plate portion 211 and a hexagonal columnar screw portion 212 in the center of one side surface thereof. A screw hole 213 for wearing the main muscle pivot is formed from the screw portion 212 to a part of the fixing plate portion 211. Further, a filler inlet 214 that penetrates the center of the fixing plate 211 is formed, and the filler inlet 214 communicates with the screw hole 213. When using the screw fixing plate 210, the screw portion 212 is screwed into the end of the beam main bar 201, and a high-strength non-shrink mortar 209 is injected between the screw portion 212 and the beam main bar 201 through the filler inlet 214 and fixed. It is something to be made.

Further, as another form of the screw penetration type fixing plate, as shown in Patent Document 3, it is a fixing metal used for fixing and jointing of a screw rebar having a male flat portion, which is slightly larger than the screw outer diameter of the screw rebar. It has a screw rebar through-hole consisting of a large inner diameter and a female flat part, and a screw groove is formed in the female flat part to be screwed into the thread of the screw rebar, and this screw groove is the width of the screw rebar thread. There is a wedge screw type fixing hardware formed in a wedge shape so that it gradually becomes thinner by half a turn. According to this, when the screw rebar is set, the female flat portion and the male flat portion are matched to allow the screw rebar to penetrate inside without rotating (screwing) the hardware. The hardware can be set to the screw rebar by half-turning at the point.
Japanese Patent No. 2662150 Japanese Patent Publication No. 52-40130 JP-A-7-109790

  The conventional screw penetration type fixing plate can be used by hand tightening, but due to the backlash in the tension direction of the screw rebar and the fixing plate, they cannot be firmly connected to each other and the proof stress is insufficient. Further, in the wedge screw type fixing hardware of Patent Document 3, it is inevitable that an extra process for forming a flat portion (male flat portion) on the screw rebar is required, resulting in an increase in cost. The female screw is screwed only in the flat region in the circumferential direction of the screw hole of the fixing metal, and since the female screw is wedge-shaped, only a part of the female screw meshes with the male screw, so that the normal parallel spiral screw penetration type fixing Compared with the plate, the male / male screw has a smaller mutual contact (metal touch) area, and the frictional force is insufficient, and play tends to occur.

  In addition, the conventional bag screw type fixing plate usually has a consideration such as displaying a necessary screwing length in advance at the end of the screw reinforcing bar in order to confirm to which position the screw reinforcing bar has been screwed. There is a problem that an extra process is required, for example, marking the end of the screw rebar by painting or the like. Also, if a foreign object is bitten, the foreign object cannot be confirmed, and the machine must be forced to tighten.

  Furthermore, in general industrial shearing methods for threaded reinforcing bars, the shear plane cannot guarantee a geometrically accurate vertical cross section with respect to the longitudinal direction of the reinforcing bars, and the cross-sectional properties are not microscopically smooth. There are also screw rebars that are defective and have protrusions (burrs, etc.) inside. In the case of such a threaded reinforcing bar, even if it is screwed to a predetermined position, the protrusion on the end face of the threaded reinforcing bar and the bag bottom of the bag screw type fixing plate are in a point contact state, and play is likely to occur.

  In view of the above-mentioned problems, the present invention can be hand-tightened and hardly generates rattling, does not require a reinforcing bar marking process, can check for abnormalities such as foreign matters and screwed positions, and has some end surface shape defects at the end of the screw reinforcing bar. It is an object of the present invention to provide an acceptable screw rebar anchor plate and anchor structure.

  The inventors have intensively studied to achieve the above object, and in the screw penetration type fixing plate, from the exit of the screw hole through which the steady female screw portion screwed with the male screw of the screw rebar is penetrated to a position inside several pitches. The lead angle of the trough face on the other side is kept the same as that of the steady female thread, with the lead angle of the trough face on the side subjected to the tensile load of the reinforcing bar among the two trough faces facing within the female thread trough. Has been conceived to be smaller than that of the stationary female screw portion, and the present invention has been made. That is, the present invention is as follows.

1. The fixing plate of the screw rebar has a through screw hole penetrating the fixing plate, and the through screw hole is
The inner diameter, outer diameter, and thread pitch from the inlet of the through screw hole are unchanged, and the inner diameter lead angle and outer diameter lead angle of the following A side valley surface are the same as the inner diameter lead angle and outer diameter lead angle of the following B side valley surface. A stationary female thread portion extending and threadingly engaged with the male thread of the threaded reinforcing bar,
It extends in the range from the outlet of the through screw hole to the inner position by 0.5 to 5 pitches at the thread pitch of the steady female thread portion, and is connected to the steady female thread portion. The inner diameter lead angle and outer diameter lead angle of the side valley surface are similar to those of the steady female thread portion, and the inner diameter lead angle and outer diameter lead angle of the following B side valley surface are smaller than that of the stationary female screw portion, And a non-stationary female thread portion that decreases as it approaches the exit of the through screw hole.

A side trough surface: female thread trough surface on the side subjected to tensile load from the threaded reinforcing bar B side trough surface: trough surface on the side opposite to the A side trough surface 2. The fixing plate for screw reinforcing bars according to item 1, wherein the fixing plate is fastened to an end portion of the screw reinforcing bars by hand tightening.

  3. A fixing structure of a screw rebar comprising the fixing plate described in the preceding item 1 or 2 attached to an end of the screw rebar.

According to the present invention, since it is a screw penetration type fixing plate having a through screw hole, a reinforcing bar marking step is unnecessary, an abnormality such as a foreign object and a screwing position can be confirmed, and an end surface shape defect at the tip of the screw reinforcing bar is prevented. Tolerable to some extent.
In addition, since the through screw hole is composed of the steady female screw portion and the non-steady female screw portion defined in the present invention, when attaching the fixing plate to the screw rebar, it is only necessary to screw in the fixing plate while lightly pulling the fixing plate. The B-side trough surface of the unsteady female threaded portion is pressed against one of the crest surfaces of the male thread of the threaded rebar, and the A-side trough surface is entirely threaded male threaded in both the steady female threaded portion and the unsteady female threaded portion. In contact with the other mountain surface. Therefore, according to the present invention, when the fixing plate is attached to the screw rebar, it can be hand-tightened and hardly play.

  FIG. 4 is a schematic view showing an example of the fixing plate of the present invention. In the figure, 1 is a fixing plate, 1A is a bulging portion of the fixing plate 1 (acts as an anchor for concrete), 2 is a stationary female screw portion, 3 is an unsteady female screw portion, 4 is a through screw hole, and 5 is a through screw hole. 4 is an inlet (screwing start end), 6 is an outlet of the through screw hole 4 (screwing end port), 7 is an A side valley surface, 8 is a B side valley surface, and 10 is a screw reinforcing bar (not shown) for the fixing plate 1. , 11 is the tension direction of the fixing plate 1. The A side trough surface 7 is a female thread trough surface that receives a tensile load acting in the direction of the tensile direction 11 from the screw reinforcing bar, and the B side trough surface 8 is a trough surface on the opposite side to the A side trough surface 7. .

As the material of the fixing plate 1, for example, austempered spheroidal graphite cast iron, ductile cast iron, SC material, high tensile strength steel having a tensile strength of 490 MPa can be preferably used. The fixing plate 1 may be provided with a hole corresponding to the filler inlet 208 of FIG.
The steady female thread portion 2 has an inner diameter d ₁ , an outer diameter d ₂ , and a thread pitch P that are unchanged from the inlet 5 of the through screw hole 4, and an inner diameter lead angle θ ₁ and an outer diameter lead angle θ ₂ on the A side valley surface are B. It is assumed to be homologous with the inner diameter lead angle θ ₄ and the outer diameter lead angle θ _{3 of the} side valley surface and extends. The form of the steady female screw portion 2 is the same as that of a normal female screw in which the thread width and the valley width are constant throughout the screw length direction.

The pitch P of a spiral wound around a cylinder of diameter d with a lead angle θ is
P = π × d × tan θ (1)
It is represented by In a normal female screw (same for a male screw), as a lead angle in a broad sense, θ calculated using the nominal diameter d _call and the effective diameter d _eff = (d ₁ + d ₂ ) / 2 as the diameter d in the equation (1). In the present invention, in order to define the difference between the forms of the stationary female screw portion 2 and the non-steady female screw portion 3, in the present invention, as a lead angle in a narrow sense, the inner diameter d ₁ , the outer diameter as the diameter d in Equation (1) Each θ calculated by substituting d ₂ is used. That is, in the steady female thread portion 2, the following expression is established.

θ ₁ = θ ₄ = tan ⁻¹ (P / (π × d ₁ )) (2)
θ ₂ = θ ₃ = tan ⁻¹ (P / (π × d ₂ )) (3)
The unsteady internal thread portion 3 has the same inner diameter and outer diameter d ₁ and d ₂ as the stationary internal thread portion 2, and the pitch P of the stationary internal thread portion 2 from the outlet 6 of the through screw hole 4 is 0.5 to 5 pitches (see FIG. In the example of 4 1.25 pitches), it extends to the inner position and continues to the steady female thread portion 2.

Unsteady inner diameter lead angle theta ₁ of the female screw portion 3 of the A Gawatanimen 7 _'and the outer diameter lead angle theta _2' has an inner diameter lead angle theta ₁ and outer diameter lead angle of A Gawatanimen 7 of constant internal thread portion 2 theta ₂ and homologous to each other. That is, θ ₁ ′ = θ ₁ and θ ₂ ′ = θ ₂ .
On the other hand, the inner diameter lead angle θ ₄ ′ and the outer diameter lead angle θ ₃ ′ of the B-side valley surface 8 of the unsteady female thread portion ₃ are the inner diameter lead angle θ ₄ and the outer diameter lead of the B-side valley surface 8 of the stationary female thread portion 2, respectively. It is smaller than the angle θ ₃ . That is, θ ₄ ′ <θ ₄ and θ ₃ ′ <θ ₃ . Therefore, the inner diameter pitch P ₄ ′ and the outer diameter pitch P ₃ ′ of the B-side valley surface 8 of the unsteady female thread portion 3 are:
P ₄ ′ = π × d ₁ × tan θ ₄ ′ <π × d ₁ × tan θ ₄ = P (4)
P ₃ ′ = π × d ₂ × tan θ ₃ ′ <π × d ₂ × tan θ ₃ = P (5)
Thus, the female thread valley width w of the unsteady female thread portion 3 gradually decreases at a decreasing rate proportional to (P−P ₄ ′) / P as it approaches the outlet 6 of the through screw hole 4. Note that the female thread root width (not shown) of the unsteady female thread portion 3 gradually decreases at a decreasing rate proportional to (P−P ₃ ′) / P as it approaches the outlet 6 of the through screw hole 4.

  Therefore, when a screw rebar having a crest width smaller than the valley width of the stationary female screw portion 2 of the fixing plate and larger than the trough width of the unsteady female screw portion 3 at the outlet 6 of the through screw hole 4 is applied to the screw rebar. When the fixing plate 1 is screwed while lightly pulling in the direction of the pulling direction 11, the steady female screw portion 2 smoothly engages with the screw rebar, and the non-steady female screw portion 3 meshes with the male screw of the screw rebar. 6, the B-side trough surface 8 of the unsteady female thread portion 3 is gradually pressed strongly by one of the crest surfaces of the male thread of the screw rebar in contact therewith. As a result, both the steady screw portion 2 and the unsteady screw portion 3 are A Since the side valley surface 7 is in full contact (with no gap) with the other crest surface of the external thread of the threaded reinforcing bar facing this, a large frictional force is obtained because the mutual contact area is increased. Therefore, according to the present invention, when the fixing plate 1 is attached to the screw rebar, it can be hand-tightened and hardly play.

  However, if the extension range of the unsteady internal thread portion 3 from the outlet 6 of the through screw hole 4 to the inside (abbreviated unsteady internal thread range) is smaller than the pitch P of the steady internal thread portion 2 by 0.5 pitches, the screw rebar Since the meshing range with the male screw is too small, a sufficient tightening state cannot be obtained, and play tends to occur. On the other hand, even if the unsteady female thread range is larger than 5 pitches by the pitch P, the tightening strength is not likely to increase any more. Therefore, in the present invention, the unsteady internal thread range is limited to 0.5 to 5 pitches with the pitch P.

  In addition, it is preferable that the inner diameter lead angle and the outer diameter lead angle of the B-side trough surface of the unsteady female screw portion are 0.2 ° or more smaller than the corresponding lead angle (synonymous lead angle) of the steady female screw portion, respectively. That is, it is preferable that the inner diameter lead angle and the outer diameter lead angle of the B-side trough surface of the unsteady female thread portion are each 0.2 degrees or more from the corresponding lead angle of the steady female thread portion. This is because when the angle reduction is less than 0.2 °, it is difficult to obtain a sufficiently strong fastening state within the range of the unsteady internal thread corresponding to 0.5 to 5 pitches. However, no matter how much the angle reduction is increased, if the inner diameter lead angle and the outer diameter lead angle of the B-side trough surface of the unsteady internal thread portion become 0 °, the B-side trough surface of the unsteady internal thread portion Since the screw pitch becomes zero and screwing becomes impossible, it is preferable that the angle reduction is 0.2 ° or more under the restriction that these lead angles are kept above 0 °.

As an example of the present invention, a fixing plate (having the form shown in FIG. 4) in which the unsteady female thread range is 1.25 pitches with the pitch P of the stationary female thread portion was produced. The material of the fixing plate was austempered spheroidal graphite cast iron. In the fixing plate of this example, the inner diameter lead angle θ of the A side trough surface of the steady female thread portion is adapted to each size of screw rebars of various sizes DXX (JIS standard deformed bar steel nominal diameter) shown in Table 1. _1, the outer diameter lead angle theta _2, B-side trough surface outside diameter lead angle theta ₃ of the same _surface, the inner diameter lead angle theta ₄ of the same _faces, and, of unsteady internal thread portion, inner diameter lead angle of the a-side trough surface theta ₁ ', the outer diameter lead angle theta ₂ in the same plane', the outer diameter lead angle theta ₃ of B side valley surface were designed ', inner diameter lead angle theta ₄ of the same _surface' to the values shown in table 1, respectively.

  The fixing plate of this example was attached to the end of a correspondingly sized screw reinforcing bar to form a fixing structure. At this time, any fixing plate could be fastened to a screw rebar of a corresponding size without causing looseness by hand tightening, and the fastened state was sufficiently strong. In addition, it was possible to confirm abnormalities such as foreign matters and the screwing position without rebar marking when screwing. Further, even if there was a burr-like protrusion due to rough shear on the end face of the screw rebar on the side where the fixing plate was screwed, it was possible to mount it to a sufficiently strong fastening state by hand tightening as in the case without such a protrusion.

It is the schematic which shows an example of the conventional screw fixing board (screw penetration type). It is the schematic which shows an example of the conventional screw fixing board (screw penetration type). It is the schematic which shows an example of the conventional screw fixing board (bag screw type). FIG. 3 is a schematic diagram illustrating an example of a fixing plate of the present invention.

Explanation of symbols

1 Fixing plate (present invention)
1A bulge 2 steady female thread 3 unsteady female thread 4 through screw hole 5 through screw hole entrance (starting screw opening)
6 Outlet of through screw hole (screwing end port)
7 A side trough surface (female thread trough surface on the side subjected to tensile load from screw rebar)
8 B side trough (valley side opposite to A side trough)
10 Tensile direction from screw rebar
11 Fixing plate tension direction
111 Rebar
112 Female thread
112 'End bulge
201 Beam reinforcement
204 Screw fixing plate (screw penetration type)
205 Fixing plate
206 Screw part
207 Screw hole
208 Filler inlet
209 High strength non-shrink mortar
210 Screw fixing plate (bag screw type)
211 Fixing plate
212 thread
213 Screw hole
214 Filler inlet d ₁ Inner diameter d ₂ Outer diameter P Thread pitch of steady thread part w Female thread valley width θ ₁ Inner diameter lead angle of A side valley face of steady female thread part θ ₂ Outer diameter of A side valley face of steady female thread part Lead angle θ ₃ Outer diameter lead angle of B-side trough surface of steady female thread portion θ ₄ Inner diameter lead angle of B-side trough surface of steady female thread portion θ ₁ 'Inner diameter lead angle of A-side trough surface of unsteady female thread portion θ ₂ ' Outer diameter lead angle of the A-side trough surface of the unsteady female thread portion θ ₃ 'Outer diameter lead angle of the B-side trough surface of the unsteady female thread portion θ ₄ ' Inner diameter lead angle of the B-side trough surface of the unsteady female thread portion

Claims (3)

The fixing plate of the screw rebar has a through screw hole that penetrates the fixing plate,
The inner diameter, outer diameter, and thread pitch from the inlet of the through screw hole are unchanged, and the inner diameter lead angle and outer diameter lead angle of the following A side valley face are the same as the inner diameter lead angle and outer diameter lead angle of the following B side valley face. A stationary female thread portion extending and threadingly engaged with the male thread of the threaded reinforcing bar,
It extends in the range from the outlet of the through screw hole to the inner position by 0.5 to 5 pitches in the thread pitch of the steady female thread part, and is connected to the regular female thread part. The inner diameter lead angle and outer diameter lead angle of the side valley surface are similar to those of the steady female thread portion, and the inner diameter lead angle and outer diameter lead angle of the following B side valley surface are smaller than that of the stationary female screw portion, And a non-stationary female thread portion that decreases as it approaches the exit of the through screw hole.
A side trough surface: female thread trough surface on the side subjected to tensile load from the threaded reinforcing bar B side trough surface: trough surface on the side opposite to the A side trough surface   2. The fixing plate for screw rebar according to claim 1, wherein the fixing plate is fastened to an end portion of the screw rebar by hand tightening.   A fixing structure of a screw reinforcing bar, wherein the fixing plate according to claim 1 or 2 is attached to an end of the screw reinforcing bar.

Images