JP4228873B2 - Assembled bolt dropout prevention brackets for ridged segments - Google Patents

Description

  The present invention relates to an assembly bolt dropout prevention fitting for a segment with a relief, and more particularly to a dropout prevention fitting that can prevent loosening of an assembly bolt with a relatively simple structure.

  A segment with a tenon penetrates the fitting part from the bolt box provided on the inner surface side of one segment in a state where the tenon and the teno groove provided on the joint surface between adjacent segments are fitted. Thus, an assembly bolt that is screwed into a nut provided in the other segment is used.

  Since this assembled bolt is used for temporary fixing of the segment and is not a structurally necessary connecting bolt, it is considered that the assembled bolt is removed and reused after a predetermined period.

  Therefore, for example, an oblique bolt of a trapezoidal screw with a female side inserted is used instead of a normal metric screw bolt so that the assembled bolt can be easily tightened and easily pulled out.

  However, in the construction work, it may take time and effort to remove the assembly bolt, and after removing the assembly bolt, water leakage may occur from the bolt hole, so there are almost no examples of removing the assembly bolt, The actual situation is that it is left as it is, but the left assembly bolts are loosened and fall off over time. For example, an adhesive is applied or disclosed in Patent Document 1. As shown in the figure, measures such as mounting a fitting bolt for preventing assembly bolts are taken.

However, such conventional measures have the following technical problems.
JP 2002-147182 A

  That is, the drop-out prevention measure by applying the adhesive has a problem in durability. On the other hand, the dropout prevention measure disclosed in Patent Document 1 has a problem that a receiving hole for a metal fitting must be provided on the segment side.

  The present invention has been made in view of such a conventional problem, and the object of the present invention is that a special processing is not required on the segment side, and a tense with a predetermined durability is provided. An object of the present invention is to provide a segment assembly bolt dropout prevention fitting.

In order to achieve the above-mentioned object, the present invention provides the above-mentioned fitting from the bolt box provided on the inner surface side of one segment in a state in which the tenon provided on the joint surface between the segments and the tenon groove are fitted. In the assembly bolt drop-off prevention fitting that passes through the portion and is screwed to the nut provided in the other segment, the drop-off prevention fitting is formed of a thin plate-like member and is formed in the center of the assembly bolt. An insertion hole, a rotation restricting portion that extends on the outer periphery of the insertion hole and whose outer end abuts on the inner surface of the bolt box and restricts the rotation of the drop-off prevention metal fitting, and projects on the outer periphery of the insertion hole And a rotation- preventing piece that is bent at the head of the assembled bolt after completion of tightening and restricts looseness of the assembled bolt, and a pair of the rotation restricting portions are provided on both sides of the insertion hole. The pair of rotation restricting portions are Respectively abut against the side surface of the box.

  According to the assembled bolt drop-off prevention fitting of the segment with the chin configured in this way, the outer end abuts on the inner surface of the bolt box and includes a rotation restricting portion that restricts the rotation of the drop-off prevention fitting. When the assembly bolt is rotated to be loosened, the rotation restricting portion comes into contact with the inner surface of the bolt box to prevent the fall-off prevention metal fitting from being accompanied, and as a result, the assembly bolt is prevented from loosening.

  Further, the drop-off prevention metal fitting is provided on the outer periphery of the insertion hole, and is bent at the head of the assembly bolt after completion of tightening, and has a detent piece for restricting looseness of the assembly bolt. When the rotation is about to be loosened, the detent piece comes into contact with the head of the bolt to restrict the axial movement and prevent the assembly bolt from loosening.

  Such prevention of loosening of the assembled bolt can be obtained without applying special processing to the segment. When the loosening of the assembled bolt is prevented, it can be reliably prevented from falling off.

  The rotation restricting portion has different contact lengths with respect to the side surface of the bolt box, and the left side of the assembly bolt can be made larger than the right side.

A plurality of the anti-rotation pieces can be provided with different protruding directions.
The anti-rotation piece is composed of at least three radially extending outward from the center of the insertion hole, and the angle of the center line of each anti-rotation piece with respect to a horizontal line passing through the center of the insertion hole, It can be set to 45 °, 67.5 °, and 120 °.

  According to the assembly bolt drop-off prevention fitting for the segment with a relief according to the present invention, it is possible to prevent the assembly bolt from coming off for a long time without performing special processing on the segment.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 to FIG. 6 show an embodiment of the assembly bolt drop-off prevention fitting of the segment with a relief according to the present invention. As shown in FIG. 1, the drop-off prevention metal fitting 10 shown in these drawings is used when a pair of RC structure segments 12 and 12 a are arranged adjacent to each other and the segments 12 and 12 a are temporarily fastened by an assembly bolt 14. .

  One of the segments 12 to be connected is provided with a convex tenon 16 projecting on the joint surface, and the other segment 12a is provided with a concave teno groove 18 fitted to the tenon 16.

  The assembly bolt 14 passes through the fitting portion of the hoso 16 and the hoso groove 18 from the bolt box 20 provided on the inner surface of the one segment 12 with the hoso 16 and the hoso groove 18 fitted. Then, it is screwed onto the nut 22 provided on the other segment 12a.

  As shown in detail in FIGS. 2 and 3, the drop-off prevention metal fitting 10 is composed of a thin plate-like member, and includes a main body portion 10 a, an insertion hole 10 b, right and left rotation restricting portions 10 c and 10 d, 3 The book is provided with book-locking pieces 10e, 10f, and 10g.

  The main body portion 10a is formed in a substantially square shape, and an insertion hole 10b is formed at substantially the center thereof. The assembly bolt 14 is inserted into the insertion hole 10b. The right and left rotation restricting portions 10c and 10d are formed on both sides of the insertion hole 10b so as to protrude from both sides of the main body 10a provided with the insertion hole 10b.

  In the case of the present embodiment, the left turn restricting portion 10d has a larger overhang amount than the right turn restricting portion 10c, and the entire length is longer than the right turn restricting portion 10c. The amount of overhang may be sufficient.

  The right and left rotation restricting portions 10c and 10d arranged to face both sides of the main body portion 10a are inclined so that the outer ends that are opposed to each other and expand toward the lower side. Further, upper bent portions 10h are respectively provided at outer end edges of the right and left rotation restricting portions 10c and 10d.

  The three anti-rotation pieces 10e, 10f, and 10g are arranged on the outer periphery of the insertion hole 10b so as to protrude below the main body portion 10a. In the case of the present embodiment, the three detent pieces 10e, 10f, and 10g are set so that the protruding directions are different from each other.

  The three right, left, and center anti-rotation pieces 10e, 10f, and 10g are radially extended from the center of the insertion hole 10b outward so as to have substantially the same length, and the center of the insertion hole 10b is extended. The angles of the center lines of the anti-rotation pieces 10e, 10f, and 10g with respect to the passing horizontal line H are set to 45 °, 120 °, and 67.5 °.

  On the other hand, in the case of the embodiment, the bolt box 20 is recessed on the inner surface of the segment 12 so as to be substantially triangular as seen from the side as shown in FIG. A surface 20a is provided.

  As shown in FIG. 4, the bolt box 20 has a substantially horseshoe-shaped outer periphery of the flat portion 20 a, and a pair of side surface portions 20 c that expand in a C shape at both ends of the arc-shaped portion 20 b. Is provided.

  In addition, an insertion hole 20d for the assembly bolt 14 is formed at a substantially central portion of the flat portion 20a. FIG. 4 shows a state in which the drop-off prevention metal fitting 10 is set in the bolt box 20 formed in this way.

  At this time, the insertion hole 10b of the drop-off prevention metal fitting 10 is set so as to coincide with the insertion hole 20d. In such a set state, the bent portions 10h of the right and left rotation restricting portions 10c and 10d are provided. The outer end is arranged so as to be substantially along the side surface 20c of the bolt box 20 and adjacent to the side surface 20c.

  The drop-off prevention metal fitting 10 configured as described above is attached to the assembly bolt 14 before the assembly bolt 14 is attached to the segment 12. At this time, the assembly bolt 14 is inserted into the insertion hole 10b. In this state, the washer 24 is attached to the assembly bolt 14, and the drop-off prevention metal fitting 10 is assembled with the assembly bolt 14 as shown in FIGS. It is attached in a form sandwiched between the head 14a and the washer 24.

  When the assembly bolt 14 is set in the bolt box 20 in such a state, the right and left rotation restricting portions 10c and 10d of the drop-off prevention metal fitting 10 have the outer ends adjacent to the inner surface of the bolt box 20, and the assembly bolt 14 is When tightening, the right and left rotation restricting portions 10 c and 10 d come into contact with the inner surface of the bolt box 20 and take a reaction force from the wall surface of the bolt box 20.

  When the assembly bolt 14 is tightened in such a state, the accompanying movement of the washer 24 is prevented, and the function of preventing the washer 24 from rotating when the assembly bolt 14 is pulled out is exhibited. In this case, the protruding amounts of the right and left rotation restricting portions 10c and 10d and the contact length with the bolt box 20 can be formed symmetrically so that they are the same amount. As in the example, if the protruding amount and the contact length of the left rotation restricting portion 10d are made larger than those of the right rotation restricting portion 10c, generally, the assembly bolt 14 employs a right screw. It is more efficient to prevent the accompanying movement when the bolt 14 is tightened, that is, when the left side protrudes more than the right side or the contact length is made longer.

  When the screwing of the assembly bolt 14 is finished and the tightening is completed, one of the rotation stopper pieces 10e, 10f, and 10g is bent on the head portion 14a of the assembly bolt 14 and brought into contact with the head portion 14a. The assembly bolt 14 is prevented from loosening.

  In this case, the head 14a of the assembly bolt 14 is normally formed in a regular hexagon, and the hexagon of the head 14a is in an arbitrary position depending on the tightening state. However, in the case of the present embodiment, the three right, left, and center detent pieces 10e, 10f, and 10g are extended radially outward from the center of the insertion hole 10b, and the center of the insertion hole 10b. Since the angle of the center line of each of the detent pieces 10e, 10f, 10g with respect to the horizontal line H passing through is set to 45 °, 120 °, 67.5 °, the hexagonal shape of the head 14a is in any position. Even if it becomes, any one of the rotation prevention pieces 10e, 10f, 10g comes to be orthogonal to one side of the hexagon (in FIG. 4, the left rotation prevention piece 10f is orthogonal). In addition, the bending toward the head 14a side is simplified, and the head 14a can be securely adhered to the head 14a in the folded state.

  Now, according to the assembling bolt drop-off prevention fitting of the segment with a chin configured as described above, the rotation restricting portion that restricts the rotation of the drop-off prevention fitting 10 with the outer end contacting the inner surface of the bolt box 20. 10c and 10d, when the assembly bolt 14 is rotated to be loosened, the rotation restricting portions 10c and 10d are brought into contact with the inner surface of the bolt box 20 to prevent the drop-off preventing metal fitting 10 from being accompanied. As a result, loosening of the assembly bolt 14 is prevented.

  Further, the drop-off prevention metal fitting 10 protrudes from the outer periphery of the insertion hole 10b and is bent at the head portion 14a of the assembled bolt 14 after the tightening is completed, thereby preventing the locking pieces 10e and 10f from restricting looseness of the assembled bolt 14. 10g, when the assembly bolt 14 is rotated to be loosened, the detent pieces 10e, 10f, and 10g come into contact with the head portion 14a of the bolt 14 to restrict the movement in the axial direction. The assembly bolt 14 is prevented from loosening.

  Such prevention of loosening of the assembly bolt 14 can be obtained without applying special processing to the segments 12 and 12a. When the assembly bolt 14 is prevented from loosening, it can be reliably prevented from falling off.

  According to the present invention, the assembly bolt drop prevention bracket of the segment with a relief can prevent the assembly bolt from coming off for a long time without performing any special processing on the segment, so that tunnel construction using this type of segment is possible. Can be used effectively.

It is sectional drawing of the junction part of the segment in which the drop-off prevention metal fitting of the assembly bolt of the segment with a relief concerning this invention is used. It is a top view which shows one Example of the drop-off prevention metal fitting of the assembly bolt of the segment with a relief concerning this invention. It is a side view of FIG. It is a front view of the bolt box of the segment shown in FIG. It is side surface explanatory drawing of the state which attached | attached the assembly | attachment bolt to the drop-off prevention metal fitting concerning this invention, and was set to the bolt box. It is explanatory drawing of the other side state in which the drop-off prevention metal fitting concerning this invention was attached to the assembly bolt, and was set to the bolt box.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Fall prevention metal fitting 10a Main part 10b Insertion hole 10c Right rotation control part 10d Left rotation control part 10e Right rotation prevention piece 10f Left rotation prevention piece 10g Center rotation prevention piece 12 Segment 14 Assembly bolt 14a Head 16 Hozo 18 Hozo groove 20 Bolt box 22 Nut 24 Washer

Claims (4)

In a state where the tenon provided on the joint surface between the segments and the tenon groove are fitted, the bolt box provided on the inner surface side of one segment penetrates the fitting portion and is provided on the other segment. In the assembly bolt drop-off prevention bracket that is screwed onto the nut,
The drop-off prevention fitting is composed of a thin plate member,
An insertion hole for the assembly bolt drilled in the center;
A rotation restricting portion that extends on the outer periphery of the insertion hole, an outer end abuts against the inner surface of the bolt box, and restricts the rotation of the drop-off prevention metal fitting;
A protrusion that projects from the outer periphery of the insertion hole, is bent at the head of the assembly bolt after completion of tightening, and includes a detent that restricts looseness of the assembly bolt ;
A pair of the rotation restricting portions are provided on both sides of the insertion hole, and the pair of rotation restricting portions abut against the side surfaces of the bolt box, respectively . 2. The assembly bolt for a cruciform segment according to claim 1, wherein the rotation restricting portion has different contact lengths with respect to a side surface of the bolt box, and makes the left side of the assembly bolt larger than the right side. Fall-off prevention bracket. The assembly bolt drop prevention fitting for a segment with a relief as claimed in claim 1 or 2, wherein a plurality of the rotation stopper pieces are provided with different protruding directions. The anti-rotation piece is composed of at least three radially extending outward from the center of the insertion hole, and the angle of the center line of each anti-rotation piece with respect to a horizontal line passing through the center of the insertion hole, The assembly bolt drop-off prevention fitting for a segment with a relief according to any one of claims 1 to 3, wherein the bracket is set to 45 °, 67.5 °, and 120 °.

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