JP2019044496A - Screw type reinforcement joint and fastening confirmation washer - Google Patents

Abstract

To provide a screw type reinforcement joint in which whether a lock nut is fastened at a prescribed torque can be visually and easily confirmed.SOLUTION: A screw type reinforcement joint comprises male screw portions 1c, 1c provided at ends of a pair of reinforcements 1, 1, a screw cylindrical coupler 2, and a lock nut 3. A fastening confirmation washer 4 is interposed between the coupler 2 and the lock nut 3. The fastening confirmation washer 4 includes a protrusion 4b protruding in a thickness direction in a natural state, and is elastically deformed in a flat shape when applied with a compressive force larger than a prescribed value between both faces.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a threaded rebar joint and a tightening confirmation washer used for reinforced concrete.

  There are various types of reinforcement joints used for reinforced concrete, such as lap joints, and in order to simplify the arrangement structure and shorten the construction period, a male screw part is provided at the end of the reinforcement bar and connected with a screw cylindrical coupler There is a screw type rebar joint that In this threaded rebar joint, it has been proposed to provide a lock nut that is tightened in contact with the end face of the coupler in order to eliminate rattling and to ensure tightening (e.g., Patent Document 1).

Patent No. 5869716

The lock nut is mounted in contact with the end face of the coupler, but even if it appears to be in contact with the end face of the coupler, it can not be determined whether or not it is tightened in a state where sufficient tightening torque is applied. Although a large torque is not necessary, it is necessary to apply a certain torque or more. Therefore, it is necessary to confirm the tightening torque with a torque wrench or the like at the time of the tightening operation or at the time of the later inspection.
In the inspection of confirmation of the tightening torque of the screw type rebar joint after completion of reinforcement, for example, there are several hundred screw type rebar joints in one building or the building part to be inspected, and one torque wrench is placed at each one. It is necessary to confirm by etc., and a lot of time is required for inspection.

An object of the present invention is to provide a threaded rebar joint which can easily check visually whether a lock nut is tightened at a prescribed torque.
Another object of the present invention is to provide a tightening confirmation washer which is used in a threaded rebar joint and which can easily check visually whether or not the lock nut is tightened to a specified torque.

According to the screw type reinforcing bar joint of the present invention, a male screw portion provided at the opposite end of a pair of reinforcing bars, a screw cylindrical coupler screwed across both male screw portions, and the coupler screwed with the male screw portion A threaded rebar joint having a lock nut for axially pressing
Between the coupler and the lock nut, there is a clamping confirmation washer which has a projecting portion which naturally protrudes in the thickness direction and which is elastically deformed flatly by a compressive force equal to or greater than a specified value acting between both surfaces. It is characterized by

According to this configuration, at the stage where the lock nut is simply screwed into contact with the tightening confirmation washer, the tightening confirmation washer has a projecting portion, so a gap is generated between the tightening confirmation washer and the coupler or the lock nut. . From this state, as the lock nut is tightened, the tightening confirmation washer flattens and the elastic restoring force gradually increases, and when the tightening confirmation washer is tightened until the gap between the coupler and the lock nut disappears, the above specified value is exceeded. A compression force of between the coupler and the lock nut is generated.
Therefore, the lock nut has a specified torque by visually confirming that the tightening confirmation washer is in a flat state, that is, the tightening confirmation washer is in close contact with both the coupler and the lock nut. It can be concluded that it is tightened with As described above, since it can be easily confirmed visually whether the lock nut is tightened to a specified torque or not, the tightening torque of a large number of screw type rebar joints is checked in the inspection process before placing concrete after reinforcement. Also in the case of performing the confirmation operation of the above, it can be performed in a short time.

  In the screw type reinforcing bar joint of the present invention, the tightening confirmation washer includes an annular disc portion and the projecting portion, and as the projecting portion, the fastening confirmation washer is positioned at a plurality of circumferential positions in the disc portion and circumferentially It may be a shape having a cut-and-raised piece-like inclined projecting piece that rises obliquely to become higher gradually.

The tightening confirmation washer may have any shape as long as it has a projecting portion that protrudes in the thickness direction in a natural state, and various shapes such as a toothed washer, a disc spring, and a split spring washer can be adopted. On the other hand, if it has a shape having inclined projecting pieces that obliquely rise at a plurality of circumferential positions, it is easy to visually confirm whether the tightening confirmation washer is in contact with either the coupler or the lock nut without a gap, It is easy to make.
When the position of the inclined projecting piece is the inner periphery of the tightening confirmation washer, even if the tightening confirmation washer is formed with a large diameter with respect to the coupler or the lock nut, the inclined projecting piece and the coupler or the lock nut A large radial clearance can be obtained. Thus, since it can be formed to have a large diameter and the inclined projecting piece can also be formed large, it is produced so as to be flat with a compression force of a prescribed value, compared to the case where the tightening confirmation washer has a small diameter and the inclined projecting piece is small. The accuracy required for the dimensions and shapes is low, which also makes it easy to produce a clamping confirmation washer.

In the screw type reinforcing bar joint according to the present invention, the tightening confirmation washer is formed of an annular disc portion and the projecting portion, and the projecting portion has a shape having embossed projections at a plurality of circumferential positions. Also good.
In the case where the projecting portion is the inclined projecting piece in the form of the cut and raised piece, it is difficult to increase the compressive force required to form a flat shape. Therefore, in order to increase the specified value, it is necessary to increase the thickness of the tightening confirmation washer. On the other hand, if it is an emboss-like projection, the compression force required to form a flat shape is large, for example, 7 to 8 times as large as that of the inclined projecting piece. The board thickness can be made relatively thin.

Note that, as the protruding portions, the cut and raised piece-like inclined protruding pieces and the emboss-like protruding portions may be used, for example, alternately arranged in the circumferential direction.
When used in combination, a large gap can be obtained by the cut-and-raised piece-like inclined projecting piece, and the emboss-like projection can be configured to be flattened with a large compressive force.

In the screw type rebar joint according to the present invention, the tightening confirmation washer includes an annular disc portion and the projecting portion, and a flat washer overlaps the surface of the projecting portion of the tightening confirmation washer, and the tightening is performed. The confirmation washer and the plain washer may be interposed between the coupler and the lock nut.
If the outside diameter of the tightening confirmation washer is about the same as the outside diameter of the coupler or lock nut, the tightening confirmation washer must be manufactured so as to be flat with a small outside diameter and a prescribed compression force. If the outside diameter of the tightening confirmation washer is made sufficiently large relative to the coupler or lock nut, it is easy to manufacture the tightening confirmation washer so as to be flat with the specified compression force. The engagement dimension with respect to the coupler end face and the lock nut width surface, that is, the radial dimension is reduced.
In this regard, by overlapping the plain washers as described above, the outer diameter of the tightening confirmation washer can be increased without causing the problem of the space, and the manufacture of the tightening confirmation washer becomes easy.

The first tightening confirmation washer according to the present invention is a washer interposed between a screw-shaped coupler and a lock nut which are engaged with and screwed to an external screw provided on a reinforcing bar, and includes an annular disc portion and this disc portion It consists of protruding parts provided at multiple locations in the circumferential direction of the disc part, and is a raised piece in the form of cut and raised pieces that are located at multiple locations in the circumferential direction of the above disc part and rise gradually in the circumferential direction. And is elastically deformed in a flat manner when a compressive force equal to or greater than a specified value acts between the coupler and the lock nut.
With this configuration, by tightening the female screw member by interposing the tightening confirmation washer, the tightening confirmation can be performed visually and, as described above, the tightening confirmation so as to be flat with a prescribed compression force. It is easy to make a washer.

The second tightening confirmation washer according to the present invention is a washer interposed between a screw-shaped coupler and a lock nut which are engaged with and screwed to an external screw provided on a reinforcing bar, and includes an annular disc portion and this disc portion It consists of protruding parts provided at multiple locations in the circumferential direction of the disc part, which has embossed projections as this protruding part, and a compressive force equal to or greater than a specified value acts between the coupler and the lock nut It is elastically deformed flat.
With this configuration, by tightening the female screw member with the clamping confirmation washer interposed, the clamping confirmation can be performed visually and the specified value of the compression force without thickening the plate thickness of the clamping confirmation washer It is easy to make

  In the tightening confirmation washer according to the present invention, a male screw portion provided at the opposite end of a pair of reinforcing bars, a screw cylindrical coupler screwed across both male screw portions, and the male screw portion screwed with the coupler A threaded rebar joint having an axially pressing lock nut, wherein the coupler and the lock nut have a projecting portion that naturally protrudes in the thickness direction, and a compressive force greater than a specified value between both surfaces. Since the clamping confirmation washer which elastically deforms flatly intervenes by acting, it is possible to easily confirm visually whether the lock nut is tightened to a prescribed torque or not.

  The first tightening confirmation washer according to the present invention is a washer interposed between a screw-shaped coupler and a lock nut which are engaged with and screwed to an external screw provided on a reinforcing bar, and includes an annular disc portion and this disc portion It consists of protruding parts provided at multiple locations in the circumferential direction of the disc part, and is a raised piece in the form of cut and raised pieces that are located at multiple locations in the circumferential direction of the above disc part and rise gradually in the circumferential direction. Is used for a screw type rebar joint and the lock nut is tightened at a specified torque, because it is elastically deformed flatly by the compressive force exceeding the specified value acting between the coupler and the lock nut Whether or not it can be easily confirmed visually.

  The second tightening confirmation washer according to the present invention is a washer interposed between a screw-shaped coupler and a lock nut which are engaged with and screwed to an external screw provided on a reinforcing bar, and includes an annular disc portion and this disc portion It consists of protruding parts provided at multiple locations in the circumferential direction of the disc part, which has embossed projections as this protruding part, and a compressive force equal to or greater than a specified value acts between the coupler and the lock nut It is possible to easily check visually whether or not the lock nut is tightened with a prescribed torque, as it is used in a screw-type rebar joint, because it is elastically deformed flatly, and the above-mentioned compression without thickening the plate thickness The specified value of force can be increased.

(A) is a cross-sectional view of a screw-type rebar joint according to a first embodiment of the present invention, (B) is a side view of a tightening confirmation washer thereof, and (C) is a cross-sectional view of the same screw-type rebar joint. It is a front view which shows the state before locking a lock nut of the screw type rebar joint. It is a front view showing the lock nut tightening completed state of the screw type rebar joint. It is a partial expanded sectional view which expands and shows the mesh | engagement part of the screw type rebar joint. It is a front view which shows an example of the external thread part in the screw type rebar joint. It is a front view which shows the other example of the external thread part in the threaded rebar joint. It is a front view which shows the further another example of the external thread part in the threaded rebar joint. (A) is sectional drawing of the screw-type rebar joint which concerns on other embodiment of this invention, (B) is sectional drawing of the modification. (A) is a side view which shows the modification of a clamping confirmation washer, (B) is the sectional drawing. (A) is a side view which shows the other modification of a clamping confirmation washer, (B) is a side view which shows further another modification. (A) is a perspective view showing another modification of the tightening confirmation washer, (B) is a cross-sectional view taken along the line XIB-XIB 'of FIG. (A), (C) is an end view of XIC-XIC' of FIG. It is. It is a perspective view which shows the further another modification of a clamp confirmation washer. It is a perspective view which shows the further another modification of a clamp confirmation washer. The side view which shows the further another modification of a clamping confirmation washer, (B) is the sectional drawing. The side view which shows the further another modification of a clamping confirmation washer, (B) is the sectional drawing. The side view which shows the further another modification of a clamping confirmation washer, (B) is the sectional drawing. It is a perspective view which shows the further another modification of a clamp confirmation washer.

  A first embodiment of the present invention will be described in conjunction with FIGS. This threaded rebar joint is a rebar joint connecting a pair of rebars 1 and 1 and has male screw parts 1c and 1c at opposite ends of both rebars 1 and 1, and the male threads of both rebars 1 and 1 The coupler 2 comprises a coupler 2 consisting of a screw cylinder screwed across the portions 1c, 1c, and a pair of lock nuts 3 and 3 screwed onto the respective male screw portions 1c, 1c to press the coupler 2; Tightening confirmation washers 4 and 4 intervene between the end faces and the lock nuts 3 and 3. The tightening confirmation washer 4 may be interposed only between one of the lock nuts 3 and the end face of the coupler 2.

  Each reinforcing bar 1 has a node portion 1 b on the outer peripheral surface of the round shaft-shaped reinforcing bar body 1 a. The node portions 1 b may be alternately provided every half turn. Further, the reinforcing bar 1 may have a rib extending in the longitudinal direction. Furthermore, the ridges of each reinforcing bar 1 may have a helically extending shape, a so-called screw node or the like.

The male screw portion 1 c of the reinforcing bar 1 may have any configuration shown in FIGS. 5 to 7. The external thread portion 1c in the example of FIG. 5 has a thread diameter D2 larger than the outer diameter D0 of the rebar main body 1a and smaller than the rebar maximum diameter D1 including the node portion 1b, and the thread groove diameter D3 is the rebar main body 1a Smaller than the outer diameter D1 of In the male screw portion 1c of this example, an enlarged diameter processing portion is formed at the time of roll forming to form a deformed rebar, and a thread groove is rolled in the enlarged diameter processing portion.
The male screw portion 1c in the example of FIG. 6 is an example in which a thread groove is formed as it is without subjecting the reinforcing bar 1 to a process such as diameter expansion processing.
As for the male screw part 1c of the example of FIG. 7, the screw thread diameter D2 and the thread groove diameter D3 are larger than the rebar maximum diameter D1. In this example, even if the male screw portion 1c in this example is a portion formed by forming an enlarged diameter portion in the reinforcing bar 1 and screwed, a male screw member manufactured separately from the reinforcing bar 1 is joined to the end face of the reinforcing bar 1 by friction welding or the like It may be

  In FIG. 1, the coupler 2 is a screw cylinder in which the entire inner periphery is an internal thread portion 2a, and is a fastening length sufficient to ensure the tensile strength required as a rebar joint to the external thread portion 1c of the rebar 1 Ru. The outer diameter surface of the coupler 2 may be a cylindrical surface, or part or all of the axial direction may be a polygon such as a hexagon.

  The lock nut 3 may have a non-circular outer peripheral surface such as a polygon such as a hexagon. The axial width of the lock nut 3 is set to a length that can ensure the compression resistance required for the reinforcing bar joint. The lock nut 3 is responsible for transmitting the compression force as follows.

  The operation of the lock nut 3 will be described with reference to FIG. In addition, in the same figure, in order to simplify the explanation, the tightening confirmation washer 4 is omitted. When a tensile force (shown by a solid arrow in the same figure) acts on the rebars 1 and 1 on both sides, from the surface 1ca on the coupler 2 side of the thread of the male thread 1c of the rebar 1, the female thread 2a of the coupler 2 The tensile force is transmitted to the surface 2aa on the screw tube center side of the screw thread. Therefore, the tensile force is directly transmitted from the reinforcing bar 1 to the nut 2 and transmitted to the other reinforcing bar 1, and the meshing strength of the lock nut 3 does not affect the transmission of the tensile force.

  When a compressive force (shown by a broken arrow in the same figure) acts on the rebars 1 and 1 on both sides, the lock nut 3 is formed from the surface 1da of the screw thread on the thread of the ridge upper thread portion 1d of the rebar 1 The compressive force is transmitted to the surface 3aa on the screw tube side of the screw thread of the female screw portion 3a. The transmitted compression force is transmitted to the coupler 2 from the contact surface between the lock nut 3 and the coupler 2. That is, the compressive force is transmitted from one reinforcing bar 1 to the other reinforcing bar 1 via the lock nut 3, the coupler 2 and the other lock nut 3. The compression resistance required for the rebar joint is about half the compression resistance as compared to the yield point strength. Therefore, the fastening length of the lock nut 3 to the screw portion 1 c may be shorter than the fastening length to the coupler 2.

  In FIG. 1, the clamping confirmation washer 4 has a projecting portion 4 b which naturally protrudes in the thickness direction between the coupler 2 and the lock nut 3, and is flat by a compressive force equal to or greater than a specified value acting between both surfaces. To be elastically deformed. The outer diameter of the tightening confirmation washer 4 is larger than that of the coupler 2 and the lock nut 3.

In the first embodiment, as shown in FIGS. 1 (B) and 1 (C), the tightening confirmation washer 4 has a plurality of annular disc portions 4a and a plurality of circumferential portions on the inner peripheral portion of the disc portions 4a. In the example of illustration, it consists of the cut-and-raised piece-like inclined protrusion piece 4ba provided at equal intervals etc. in three places. The plurality of inclined projecting pieces 4ba form the projecting portion 4b. Each inclined protruding piece 4ba is obliquely raised so as to be gradually higher in the circumferential direction. The three inclined projecting pieces 4ba have the same shape.
The inclined projecting pieces 4ba are formed by actually cutting and raising a plate-like and annular material in this example, but the processing method is not limited.
In addition, although the inclined projecting piece 4ba is provided on the inner peripheral portion of the disc portion 4a in this example, the disc may be provided on the outer peripheral portion of the disc portion 4a as described later with reference to FIG. You may provide in the intermediate part between the inner peripheral part of the part 4a, and an outer peripheral part.

  According to the screw type reinforcing bar joint of this configuration, as shown in FIG. 2, when the lock nut 3 is simply screwed until it comes into contact with the tightening confirmation washer 4, the tightening confirmation washer 4 has the projecting portion 4b. There is a gap d between the confirmation washer 4 and the coupler 2. From this state, as the lock nut 3 is tightened, the tightening confirmation washer 4 flattens and the elastic restoring force gradually increases, and as shown in FIG. 3, the gap d between the tightening confirmation washer 4 and the coupler 2 and the lock nut 3 becomes When tightened to zero, a compressive force equal to or greater than the specified value is generated between the coupler and the lock nut.

  Therefore, the lock is confirmed by visually confirming that the tightening confirmation washer 4 is in a flat state, that is, the tightening confirmation washer 4 is in contact with both the coupler 2 and the lock nut 3 without any gap. It can be concluded that the nut 3 is tightened to a specified torque. The specified value is designed to be an appropriate value as a threaded rebar joint.

  As described above, since whether or not the lock nut 3 is tightened with a prescribed torque can be easily confirmed visually, even in the inspection process before putting in concrete after laying out, there are a large number of, for example, several tens. It is possible to check the tightening torque of the threaded rebar joint in a short time. The tightening confirmation washer 4 also has an effect of eliminating rattling between the coupler and the lock nut by the elastic restoring force to the compression force by the clamping.

  FIGS. 8A and 8B respectively show other embodiments of the present invention. In this embodiment, in a state where the flat washer 5 is superimposed on the surface of the projecting side of the projecting portion 4 b (see FIG. 1 (B) (C)) on the fastening confirmation washer 4, these fastening confirmation washer 4 and flat washer 5 Is interposed between the coupler 2 and the lock nut 3. In the example of FIG. 8A, the flat washer 5 is disposed on the lock nut 3 side with respect to the tightening confirmation washer 4, but may be disposed on the coupler 2 side. Others are the same as in the first embodiment.

As described above, when the tightening confirmation washer 4 has a shape formed by the annular disc portion 4a and the projecting portion 4b, it can be elastically deformed flat by the application of a compressive force equal to or more than a specified value. If the outer diameter of the tightening confirmation washer 4 is about the same as the outer diameter of the coupler 2 and the lock nut 3, the tightening confirmation washer 4 is not manufactured so as to be flat with a specified compression force which becomes a large value with a small outer diameter. must not.
If the outer diameter of the tightening confirmation washer 4 is made sufficiently large relative to the coupler 2 and the lock nut 3, it will be easy to manufacture the tightening confirmation washer 4 so as to be flat with the above-mentioned compression force. The allowance, ie, the radial dimension, of the protruding portion 4b of No. 4 with respect to the end face of the coupler 2 and the width face of the lock nut 3 becomes small, making it difficult to flatten.
In this regard, if the plain washer 5 is overlapped as described above, the outer diameter of the tightening confirmation washer 4 can be increased without causing a problem of the space by making the plain washer 5 larger. It becomes easy to manufacture.

Hereinafter, various examples of the tightening confirmation washer 4 will be described.
In the example of FIG. 9, the tightening confirmation washer 4 has, as the projecting portions 4, embossed projections 4 bb at a plurality of locations in the circumferential direction and the inclined projecting pieces 4 ba described with FIG. 1. The embossed protrusions 4bb are provided at a plurality of locations in the circumferential direction of the tightening confirmation washer 4, and are alternately arranged with the inclined projecting pieces 4ba in the example of FIG. The protruding side of the emboss-like projection 4bb is preferably the same side as the inclined projecting piece 4ba as in the example shown in the drawing because it is easy to process, but it may be the opposite side to the inclined projecting piece 4ba .

  The emboss-like projection 4bb is a projection whose back surface is a recessed portion as shown in FIG. 6B. In the example shown in FIG. The embossed protrusions 4bb can be formed by press processing such as embossing, but may be formed by other methods.

The effects of the embossed protrusion 4bb will be described. In the case where the protruding portion 4b is the inclined protruding piece 4ba, it is difficult to manufacture so as to have a flat shape with a large compression force. In order to increase the specified value, it is necessary to increase the thickness of the tightening confirmation washer 4 or the like. On the other hand, with the embossed protrusion 4bb, the compression force required to form a flat shape is large, for example, 7 to 8 times as large as the inclined protruding piece 4ba. Therefore, the tightening confirmation is also performed when the specified value is increased. The thickness of the washer 4 can be made relatively thin.
When the inclined projecting piece 4ba and the emboss-like projection 4bb are mutually arranged as the projecting portion 4b as shown in the example of the figure, the unclamped state between the coupler 2 and the lock nut 3 by the inclined projecting piece 4ba. The gap d can be increased, and the embossed protrusion 4bb can be configured to be flattened with a large compression force.

  Describing an example of dimensions, the reinforcing bar 1 is, for example, a deformed reinforcing bar having a name of about D19 to D41. The male screw portion 1c has a nominal diameter of M19.9 and a screw pitch of 2.5 mm for the rebar 1 having a nominal name of D19. The coupler 2 is about 27 mm in flat diameter and 31 mm in diagonal of the outer peripheral surface when the outer peripheral surface is hexagonal. In the case of the reinforcing bar 1 of each diameter, the inner diameter of the tightening confirmation washer 4 is set to a size 3 to 4% larger than the nominal diameter of the male screw portion 1c of the reinforcing bar 1, and the outer diameter is the nominal diameter of the male screw portion 1c of the reinforcing bar 1 About 70% of the size of the As a specific example, the inner diameter WD2 of the disc portion 4a is 20.5 mm, the outer diameter WD1 is 33.0 to 36.0 mm, and the plate thickness is 1.2 mm. The height of the inclined projecting piece 4ba is about a screw pitch, and the inclination angle of the inclined projecting piece 4ba with respect to the disc portion 4a is 30 to 45 degrees.

In the example shown in FIG. 9, the disc portion 4a is provided on the inner peripheral portion of the disc portion 4a.
As shown to FIG. 10 (A), you may provide in the outer peripheral part of the disc part 4a, and you may provide in an inner peripheral part.

FIG. 10B shows an example in which only the embossed protrusion 4bb is provided as the protruding portion 4b of the tightening confirmation washer 4. The plate thickness of the tightening confirmation washer 4 in this case is, for example, about 1.5 to 1.8 mm in the case of the reinforcing bar 1 of D19, and about 3.0 to 3.6 mm in the case of the reinforcing bar 1 of D41.
As described above, when only the embossed protrusion 4bb is provided, the tightening confirmation washer 4 can be configured so as to be planarized with a large compression force.

FIG. 11 shows still another modification of the tightening confirmation washer. In the example shown in FIG. 9, in the clamping confirmation washer 4 shown in FIG. 9, the emboss-like projection 4bb 'is a ridge extending in the radial direction and whose back surface is a groove. The embossed protrusion 4bb 'extends from near the middle between the inner periphery and the outer periphery of the disc portion 4a to the inner peripheral edge. The groove on the back surface of the embossed protrusion 4bb 'is V-shaped in cross section.
In the case of the tightening confirmation washer 4 used for the reinforcing bar 1 whose name is D19, for example, the outer diameter WD1 of the disc portion 4a is 33.0 to 36.0 mm, the inner diameter WD2 is 20.5 mm, and the plate thickness is 1 .2 mm, length L of embossed protrusion 4bb ': 3.0 mm, groove opening width W: 3 mm, height H: 1.25 to 1.5 mm (half strength of screw pitch) . In this case, the height h of the inclined protrusion 4 ba is approximately the same as the screw pitch, for example, 2.5 mm.

Also in the tightening confirmation washer 4 of the example of the same figure, although the inclined projecting piece 4ba may be omitted and configured as shown in FIG. 12, since the inclined projecting piece 4ba returns flat with a weak force, the gap can be easily recognized In order to do this, it is preferable to provide the inclined projecting piece 4ba.
In the example of FIG. 11, FIG. 12, it is the same as that of the clamp confirmation washer 4 demonstrated with FIG. 9, FIG. 10 except the matter demonstrated especially.

The clamping confirmation washer 4 may have, for example, a truncated conical shape as a whole, as shown in FIG. In this case, the entire portion except the outer peripheral edge portion of the tightening confirmation washer 4 is the protruding portion 4b.
The tightening confirmation washer 4 in the example of FIG. 14 has an outer peripheral portion formed as an annular disc portion 4a, and from the inner periphery of the annular disc portion 4a, a plurality of tooth-like projecting pieces 4bd are on the inner peripheral side in the oblique axial direction. It has a protruding shape, so to speak a toothed washer.

In the tightening confirmation washer 4 of the example of FIG. 15, contrary to the example of FIG. 13, the disc portion 4a is provided on the inner peripheral side, and the toothed protrusion 4bd is provided on the outer periphery. It is done.
The clamping confirmation washer 4 of FIG. 16 has a split portion at one circumferential direction, and the both side portions of the split portion are circumferentially offset to form a projecting portion 4 b projecting in the thickness direction over the whole. ing.
The tightening confirmation washer 4 in the example of FIG. 17 is configured to have the projecting portion 4 b at one position in the circumferential direction.
Also in the screw-type rebar joint using the tightening confirmation washer 4 of the shape of these FIGS. 13-17, it can be easily confirmed visually whether it is tightened by prescription torque.

In addition, if it shows as an example of a reference proposal, the tightening confirmation washer of this invention and its each above-mentioned embodiment adjoins not only a reinforcing bar joint but a lock nut, other nuts, a bolt head etc., and bolts (an anchor bolt is included) Can be used for tightening confirmation.

  As mentioned above, although the form for implementing this invention based on the Example was demonstrated, the embodiment disclosed here is an illustration and restrictive at no points. The scope of the present invention is indicated not by the above description but by the claims, and is intended to include all the modifications within the meaning and scope equivalent to the claims.

1 Rebar 1c Male thread 2 Coupler 3 Lock nut 4 Tightening confirmation washer 4a Disc 4b Protrusive part 4ba Protrusive piece 4bb Embossed protuberance 5 Flat washer

Claims (6)

Male screw parts provided at opposite ends of a pair of reinforcing bars, a screw cylindrical coupler screwed on both male screw parts, and a lock nut screwed on the male screw parts and pressing the coupler in the axial direction A screw type rebar joint having
Between the coupler and the lock nut, there is a clamping confirmation washer which has a projecting portion which naturally protrudes in the thickness direction and which is elastically deformed flatly by a compressive force equal to or greater than a specified value acting between both surfaces. Screw-type rebar joint characterized by.   The screw type reinforcing bar joint according to claim 1, wherein the tightening confirmation washer is formed of an annular disc portion and the projecting portion, and as the projecting portion, the fastening confirmation washer is positioned at a plurality of circumferential positions in the disc portion Screw-type rebar joint with cut-and-raised piece-like inclined projecting pieces that rise diagonally to become gradually higher in the circumferential direction.   The screw-type reinforcing bar joint according to claim 1 or 2, wherein the tightening confirmation washer includes an annular disc portion and the projecting portion, and as the projecting portion, embossed projections are formed at a plurality of locations in the circumferential direction. Threaded rebar joint with parts.   The screw type reinforcing bar joint according to any one of claims 1 to 3, wherein the tightening confirmation washer includes an annular disc portion and the protruding portion, and the protruding portion of the tightening confirmation washer protrudes A threaded rebar joint in which a plain washer overlaps a side surface and the tightening confirmation washer and the plain washer are interposed between the coupler and the lock nut.   A washer interposed between a screw cylindrical coupler adjacent to and screwed with a male screw provided on a reinforcing bar and a lock nut, provided at an annular disc portion and a plurality of circumferential portions of the disc portion The coupler has a cut-and-raised piece-like inclined projecting piece which is positioned at a plurality of circumferential positions in the disc portion and rises obliquely in the circumferential direction as the projecting portion. A tightening confirmation washer which is elastically deformed flatly when a compressive force equal to or more than a specified value acts between the lock nut and the lock nut.   A washer interposed between a screw cylindrical coupler adjacent to and screwed with a male screw provided on a reinforcing bar and a lock nut, provided at an annular disc portion and a plurality of circumferential portions of the disc portion A clamping confirmation washer having an embossed projection as the projecting portion and which is elastically deformed flatly by a compressive force equal to or greater than a specified value acting between the coupler and the lock nut.

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