JP6572094B2 - Measuring jig for measuring the interval between screw rebars in a coupler and measuring method using the same - Google Patents

Description

  The present invention relates to a measuring jig and a measuring method for measuring a distance between tips of screw rebars in an internal cavity of the coupler after screw rebars are respectively screwed from openings on both sides of the coupler.

  In construction work and civil engineering work, joints (so-called mechanical joints) such as shown in FIG. 5 in which screw rebars 1 are screwed and connected from openings on both sides of a coupler 2 are widely used. Then, after screwing the screw rebar 1, the screw rebar 1 is fixed by injecting a grout material from a grout injection hole 3 provided in the coupler 2. In such a mechanical joint, if the length W (mm) of the portion where the screw rebar 1 and the coupler 2 are screwed together is too short, the load in the tensile direction (hereinafter referred to as tensile) acting by using it for concrete reinforcement or the like. The strength of the mechanical joint against the force) decreases.

Therefore, an upper limit value S _MAX (= 30 mm) of the interval S (mm) between the tips of the screw rebar 1 in the internal cavity of the coupler 2 is defined as an allowable range for sufficiently maintaining the strength of the mechanical joint against the tensile force. ing. Specified upper limit value S _MAX interval S between the tips of the screw reinforcing bar 1, is meant to define the lower limit of the length W of the portion screwed. That is, by screwing the screw rebar 1 so that the interval S in the internal cavity of the coupler 2 is smaller than the S _MAX value at the construction site, the length W of the screwed portion is sufficiently secured, and hence the tension is pulled. Sufficient strength of mechanical joint against force can be maintained.

  However, it is impossible to visually recognize the tip of the screw rebar 1 that has entered the internal cavity of the coupler 2 by screwing the screw rebar 1 and the coupler 2 together.

In order to solve this problem, a mark (for example, coloring with a paint) is added in advance to the position of the screw rebar 1 that satisfies S ≦ S _MAX when the screw rebar 1 and the coupler 2 are screwed together. Conventionally, a technique for obtaining a mechanical joint by screwing the screw rebar 1 to the position of the mark has been widely used. However, since this technique inevitably causes variations in the position where the screw rebar 1 is stopped from being screwed in, the tip position of the screw rebar 1 in the internal cavity of the coupler 2 is not constant, and the tip of the screw rebar 1 is not fixed. There exists a problem that the space | interval S between is easy to fluctuate | variate largely.

  Patent Document 1 discloses a technique in which the periphery of the grout injection hole 3 of the coupler 2 is cut off, a transparent member is fitted, and the screw rebar 1 is screwed in while visually observing the screw rebar 1 in the internal cavity of the coupler 2. Yes. However, this technique requires complicated processing on the coupler 2, which increases the manufacturing cost of the coupler 2, and consequently increases the construction cost of construction work and civil engineering work.

  Patent Document 2 discloses a technique for detecting the tip of a screw rebar 1 by transmitting an ultrasonic wave from the ultrasonic probe to the screw rebar 1 after screwing the screw rebar 1 into the coupler 2 to obtain a mechanical joint. Is disclosed. However, since this technology requires an expensive ultrasonic transmitter, it not only increases the construction cost of construction work and civil engineering work, but also transmits ultrasonic waves by bringing the ultrasonic probe into contact with the screw rebar 1. However, since a series of operations for receiving the echo takes a long time, there is a problem that the construction period of the construction work and the civil engineering work becomes long. Further, since the ultrasonic probe is brought into contact with the unevenness of the screw formed on the surface of the screw rebar 1 to transmit the ultrasonic wave, the detection accuracy of the tip of the screw rebar 1 is lowered and an error of about several mm is generated. There is also a problem.

JP 2012-154164 A JP 2003-279547 A

  The present invention eliminates the problems of the prior art, and after screwing the screw rebar into the coupler and before injecting the grout material, the distance between the ends of the screw rebar is efficiently and accurately measured by a simple means. An object is to provide a measuring jig and a measuring method for measuring.

In order to solve the above-mentioned problems, the present inventor inserts a member for detecting the tip of a threaded reinforcing bar in the coupler (hereinafter referred to as a reinforcing bar tip detecting member) from the grout injection hole, and the threaded reinforcing bar in the internal cavity of the coupler. The technique of measuring the position of the tip of the paper was examined. And
(a) By inserting the reinforcing bar tip detection member into the grout injection hole and bringing it into contact with the upper and lower edges of the grout injection hole, the inclination angle of the reinforcing bar tip detection member can be determined.
(b) The tip of the screw rebar and the grout injection are detected by arranging the rebar tip detection member in a plane formed by the center axis of the coupler and the center axis of the grout injection hole and detecting the tip of the screw rebar in the internal cavity of the coupler. The distance L from the center axis of the hole can be measured,
(c) It has been found that the measurement accuracy of the distance L can be further improved by providing a grout injection hole by machining (for example, a drill).

  The present invention has been made based on such knowledge.

  That is, the present invention is a rebar interval measuring jig for measuring the interval between the ends of screw rebars in the internal cavity of the coupler after screw rebars are respectively screwed from the openings on both sides of the coupler, and provided in the coupler. Inserted into the inner cavity of the coupler through the grout injection hole, the upper end remains outside the coupler, and detects the tip of the screw rebar at the lower end, and the insertion direction attached to the upper end of the rebar tip detection member And a reinforcing bar interval measuring jig in which the reinforcing bar tip detecting member and the insertion direction adjusting member form a single plane.

  In the reinforcing bar interval measuring jig of the present invention, the reinforcing bar tip detecting member may be a linear wire having an inclination angle with respect to the central axis of the grout injection hole, or a curved arc or parabolic wire. preferable. Furthermore, it is preferable that the reinforcing bar tip detection member has a scale indicating the distance between the tip of the screw reinforcing bar and the central axis of the grout injection hole. The grout injection hole is preferably provided by machining.

Further, the present invention provides a reinforcing bar tip detecting member for measuring the spacing between the ends of screw reinforcing bars in an internal cavity of the coupler after screwed reinforcing screws from openings on both sides of the coupler. Inserting into the internal cavity of the coupler from the grout injection hole provided, leaving the upper end of the reinforcing bar tip detection member outside the coupler, and contacting the reinforcing bar tip detection member to the upper and lower edges of the grout injection hole, The insertion direction adjustment member attached to the upper end of the reinforcing bar tip detection member is used to adjust the insertion direction of the reinforcing bar tip detection member, and the reinforcing bar tip detection member is placed in a plane formed by the central axis of the coupler and the central axis of the grout injection hole. insert, measure the distance L _a (mm) between the center axis of one of the tip and the grouting hole of the screw rebar by detecting the one of the front end of the screw rebar at the lower end of the reinforcing bar tip detection member, then , Is rotated 180 ° rebar tip detection member using the insertion direction adjusting member, the distance L _B (mm between the center axis of the other tip and grouting hole of the screw rebar by detecting the other tip of the screw rebar ) was measured, a rebar interval measurement method for calculating the sum of the L _a and L _B.

  In the reinforcing bar interval measuring method of the present invention, it is preferable to use a linear wire having an inclination angle with respect to the central axis of the grout injection hole, or a curved arc or parabolic wire as the reinforcing bar tip detection member. . Furthermore, it is preferable to provide a scale indicating the distance between the tip of the screw reinforcing bar and the center axis of the grout injection hole on the reinforcing bar tip detection member. The grout injection hole is preferably provided by machining.

  According to the present invention, after the screw rebar is screwed into the coupler and before the grout material is injected, the distance between the tips of the screw rebar can be measured with a simple means efficiently and accurately. Has an exceptional effect.

It is sectional drawing which shows typically the example which detects the front-end | tip of a screw reinforcement using the reinforcing bar space | interval measuring jig which concerns on this invention. It is sectional drawing which shows typically the example which detects the front-end | tip of the other screw reinforcing bar using the reinforcing bar space | interval measuring jig which concerns on this invention. It is sectional drawing which shows typically the other example of the reinforcing bar space | interval measuring jig which concerns on this invention. It is sectional drawing which shows typically the other example of the reinforcing bar space | interval measuring jig which concerns on this invention. It is a side view which shows typically the example which screwed the coupler into the both sides of the screw reinforcement.

  First, with reference to FIGS. 1 and 2, an example in which the reinforcing bar tip detecting member constituting the reinforcing bar interval measuring jig is a linear wire will be described.

  FIG. 1 is a cross-sectional view schematically showing an example in which the periphery of the grout injection hole in FIG. 5 is enlarged and the tip of the screw reinforcing bar is detected using the reinforcing bar interval measuring jig according to the present invention.

The grout injection hole 3 can be formed with an internal thread when casting the coupler 2. In particular, the grouting hole 3 having sufficient dimensional accuracy can be formed by manufacturing the coupler 2 by the precision casting technique. Further, by providing the coupler 2 with machining (for example, drilling with a drill), the dimensional accuracy of the grout injection hole 3 can be further improved. The reinforcing bar tip detection member 5 of the reinforcing bar interval measuring jig 4 is inserted into the grout injection hole 3. here,
(A) Insert the reinforcing bar tip detection member 5 in contact with the upper edge 3T and the lower edge 3B of the grout injection hole 3;
(B) By inserting the reinforcing bar tip detection member 5 into a plane formed by the central axis 7 of the coupler 2 and the central axis 8 of the grout injection hole 3, the tip of the screw reinforcing bar 1 can be accurately positioned in the internal cavity of the coupler 2. It becomes possible to detect.

  In (A) above, the upper edge 3T and the lower edge 3B of the grout injection hole 3 with which the reinforcing bar tip detection member 5 contacts are arranged on opposite sides of the center axis 8 of the grout injection hole 3 and the coupler 2 Are arranged in a plane formed by the central axis 7 of the grouting hole 3 and the central axis 8 of the grout injection hole 3. The above (B) can be easily adjusted by holding the insertion direction adjusting member 6 attached to the upper end of the reinforcing bar tip detecting member 5 and adjusting the direction thereof. By configuring the reinforcing bar interval measuring jig 4 so that the reinforcing bar tip detecting member 5 and the insertion direction adjusting member 6 form a single plane, the adjustment (B) can be easily performed. In other words, the length direction of the insertion direction adjusting member 6 may be adjusted so as to coincide with the central axis 7 of the coupler 2.

  Further, in the present invention, after the screw rebar 1 is screwed into the coupler and before the grout material is injected, the distance between the ends of the screw rebar is measured. When inserting from above, the gap between the tips of the screw rebar 1 in the coupler 2 is a cavity.

In this way, the reinforcing bar tip detecting member 5 is inserted into the inner cavity of the coupler 2 from the grout injection hole 3, and the lower end of the reinforcing bar tip detecting member 5 is brought into contact with the tip of the screw reinforcing bar 1. Since the grout injection hole 3 has a good dimensional accuracy as already described, the angle θ _A (°) formed by the reinforcing bar tip detection member 5 and the central axis 8 of the grout injection hole 3 can also be accurately maintained.

At the construction site, it is necessary to measure the distance between the tips of the screw rebar 1 for many mechanical joints. However, if the coupler 2 has the same dimensions, the screw rebar 1 screwed into the coupler 2 and screwed together Even if the position of the tip fluctuates, the angle θ _A is constant. Therefore, if the length of the reinforcing bar tip detection member 5 inserted into the internal cavity of the coupler 2 is measured at the upper edge 3T of the grout injection hole 3, the reinforcing bar tip detection member 5 and the grout injection hole 3 are based on the measured value. The length from the intersection M with the center axis 8 to the lower end of the reinforcing bar tip detection member 5 can be obtained geometrically. Then, the distance L _A (mm) between the tip of the screw rebar 1 (that is, the lower end of the reinforcing bar tip detection member 5) and the central axis 8 of the grout injection hole 3 can be obtained from the length and the angle θ _A as a trigonometric function. .

Next, as shown in FIG. 2, the reinforcing bar tip detecting member 5 is rotated 180 ° using the insertion direction adjusting member 6 to detect the tip of the other screw reinforcing bar 1, and the tip of the screw reinforcing bar 1 (that is, the reinforcing bar tip detection). A distance L _B (mm) between the lower end of the member 5 and the central axis 8 of the grout injection hole 3 is obtained. The procedure for obtaining the distance L _B is the same as the procedure for obtaining the distance L _A in FIG.

By calculating the sum of the distance L _A and the distance L _B thus obtained, the distance S (S = L _A + L _B ) between the tips of the screw rebar 1 can be determined. Further, a scale indicating the distance L (L _A in FIG. 1, L _{B in} FIG. 2) between the tip of the screw reinforcing bar 1 and the central axis 8 of the grout injection hole 3 is provided on the reinforcing bar tip detecting member 5 so as to inject the grout. If the scale is read at the upper edge 3T of the hole 3, the distance S between the tips of the screw rebar 1 is determined from the measured values in two directions of the distance L obtained by reading the scale (ie L _A and L _B ). This is preferable because it can be easily measured.

  Next, another example of the reinforcing bar interval measuring jig 4 will be described with reference to FIGS.

  The reinforcing bar interval measuring jig 4 shown in FIG. 3 is a member 9 fitted to the grout injection hole 3 (hereinafter referred to as an injection hole fitting member) with a reinforcing bar tip detection member 5 inclined and slidably mounted. . The outer diameter and length of the injection hole fitting member 9 are the same as the inner diameter and length of the grout injection hole 3, respectively.

When measuring the distance S between the ends of the screw reinforcing bars 1 using the reinforcing bar interval measuring jig 4 shown in FIG. 3, the injection hole fitting member 9 is fitted into the grout injection hole 3, and the distance L in two directions ( That is, L _A and L _B ) are measured. Also in this case, since the angle θ (that is, θ _A and θ _B ) between the reinforcing bar tip detection member 5 and the central axis 8 of the grout injection hole 3 is constant, the distance L _A is set as in the example of FIGS. distance L _B can be measured, it is possible to further determine the spacing S.

  Also in the reinforcing bar interval measuring jig 4 shown in FIG. 3, it is preferable that a scale indicating the distance L is provided on the reinforcing bar tip detection member 5 so that the scale is read on the upper surface of the injection hole fitting member 9.

  The reinforcing bar interval measuring jig 4 shown in FIG. 4 does not use the injection hole fitting member 9 but uses a reinforcing bar tip detecting member 5 made of a curved wire, and the reinforcing bar interval measuring jig 4 is grout injected. The example inserted in the hole 3 is shown.

  When the reinforcing bar interval measuring jig 4 shown in FIG. 4 is used, the relationship between the length of the reinforcing bar tip detecting member 5 inserted into the coupler 2 from the grout injection hole 3 and the position of the tip of the screw reinforcing bar 1 is investigated in advance (hereinafter referred to as “reinforcing bar spacing measuring jig 4”). It is preferable to conduct a preliminary survey). The preliminary survey will be explained.

In the preliminary investigation, the screw rebar 1 is screwed from the opening on one side of the coupler 2, and the ruler is inserted from the other opening, and the distance L between the tip of the screw rebar 1 and the central axis 8 of the grout injection hole 3. Measure _B. Further, the curved reinforcing bar tip detecting member 5 is brought into contact with the upper edge 3T and the lower edge 3B of the grout injection hole 3 and inserted into a plane formed by the central axis 7 of the coupler 2 and the central axis 8 of the grout injection hole 3. The lower end of the reinforcing bar tip detection member 5 is brought into contact with the tip of the screw reinforcing bar 1. Then, provided the scale indicating the distance L _B was measured by the above ruler reinforcing bars tip detection member 5.

And the position of the tip of the screw reinforcing bar 1 while varying similarly the distance L _B is measured, providing a scale indicative thereof to rebar tip detection member 5. The scale is preferably provided so that it can be read at the upper edge 3T of the grout injection hole 3.

In this way, the reinforcing bar tip detecting member 5 provided with the scale by making the preliminary investigation is brought into contact with the upper edge 3T and the lower edge 3B of the grout injection hole 3, and the center axis 7 of the coupler 2 and the center of the grout injection hole 3 are contacted. The distance L _B can be measured by inserting into the plane formed by the shaft 8, bringing the lower end of the reinforcing bar tip detection member 5 into contact with the tip of the screw reinforcing bar 1 and reading the scale.

Next, although not shown in the drawings, the rebar tip detection member 5 is rotated 180 ° using the insertion direction adjusting member 6 to detect the tip of the other screw rebar 1 and the tip of the screw rebar 1 (that is, the rebar tip detection member). 5) and the distance L _A (mm) between the center axis 8 of the grout injection hole 3 is measured. The procedure for obtaining the distance L _A is the same as the procedure for obtaining the distance L _B in FIG.

By calculating the sum of the distance L _A and the distance L _B thus obtained, the distance S (S = L _A + L _B ) between the tips of the screw rebar 1 can be determined.

  The shape of the curved reinforcing bar tip detecting member 5 is not particularly limited, and a curved reinforcing bar tip detecting member 5 having an arc shape, a parabolic shape, an elliptical shape, a sine curve shape, a quadratic function curve shape, or the like may be used. However, an arcuate or parabolic rebar tip detecting member 5 that can be easily processed for bending is preferable.

  In addition, you may apply said preliminary | backup investigation to the reinforcing bar front-end | tip detection member which consists of a linear wire as shown to FIG.

  As described above, according to the present invention, from the grout injection hole 3 to the internal cavity of the coupler 2 using the simple reinforcing bar interval measuring jig 4 composed of the reinforcing bar tip detecting member 5 and the insertion direction adjusting member 6. The distance between the tips of the screw rebar 1 can be measured efficiently and accurately with a simple operation of inserting.

<Example 1>
Two screw rebars (shaft body diameter 48.3mm, thread height 4.2mm, length 300mm) were manufactured and screwed in through the openings on both sides of the coupler (size D51). The coupler grout injection hole (diameter 6 mm) was provided by drilling. In this embodiment, the grout material is not injected from the grout injection hole of the coupler, but the screw rebar screwed into the coupler is referred to as a mechanical joint.

Measure the length of the screw rebar protruding from both sides of the coupler of the obtained mechanical joint, and subtract the measured value from the length of the screw rebar (= 300mm), so that the screw rebar and the coupler are screwed together The length W (see FIG. 5) of the measured part was calculated. In this way, the W value was calculated for the screw rebars on both sides, and then the total W value was subtracted from the length of the coupler to calculate the distance S between the screw rebar tips (see FIG. 5). This is S _standard .

Next, from the grout injection hole of the mechanical joint, a linear reinforcing bar tip detecting member constituting the reinforcing bar interval measuring jig shown in FIG. 1 is inserted into the inner space of the coupler, and both sides are measured by the measuring method according to the present invention. The distance L (L _A and L _{B in} FIGS. 1 and 2) between the tip of the threaded reinforcing bar and the center axis of the grout injection hole is measured and summed to determine the distance S between the ends of the threaded reinforcing bar. (See FIGS. 1 and 2) was calculated. This is S _example-1 .

When S _standard and S _example-1 thus obtained were compared, the error was 1.2 mm. As described above, the conventional measurement technique using ultrasonic waves has an error of several millimeters, but according to the present invention, it was confirmed that measurement can be performed with good accuracy.

<Example 2>
From the grout injection hole of the same mechanical joint as in Example 1, an arc-shaped (curvature radius 60 mm) reinforcing bar tip detecting member constituting the reinforcing bar interval measuring jig shown in FIG. 4 is inserted into the internal space of the coupler. The distance L between the tip of the screw rebar and the center axis of the grout injection hole was measured for each of the screw rebars on both sides, and the distance S between the tips of the screw rebar was calculated by adding them. This is S _example-2 .

When S _standard and S _example-2 thus obtained were compared, the error was 1.3 mm. As described above, the conventional measurement technique using ultrasonic waves has an error of several millimeters, but according to the present invention, it was confirmed that measurement can be performed with good accuracy.

1 Screw rebar 2 Coupler 3 Grout injection hole
Upper edge of 3T grout injection hole
3B Lower edge of grout injection hole 4 Rebar interval measuring jig 5 Rebar tip detection member 6 Insertion direction adjustment member 7 Central axis of coupler 8 Central axis of grout injection hole 9 Injection hole fitting member

Claims (8)

  A rebar interval measuring jig for measuring a distance between the ends of the screw rebars in an internal cavity of the coupler after screw rebars are respectively screwed from openings on both sides of the coupler, and a grout provided on the coupler Reinforcing bar tip detecting member that is inserted into the inner cavity of the coupler through the injection hole, the upper end remains outside the coupler, and detects the tip of the screw reinforcing bar at the lower end, and attached to the upper end of the reinforcing bar tip detecting member A reinforcing bar interval measuring jig, wherein the reinforcing bar tip detecting member and the inserting direction adjusting member form a single plane.   The said reinforcing bar front-end | tip detection member is a linear wire which has an inclination | tilt angle with respect to the center axis | shaft of the said grout injection hole, or the curved circular arc shape or the parabolic wire material of Claim 1 characterized by the above-mentioned. Rebar interval measuring jig.   3. The reinforcing bar interval measuring jig according to claim 1, wherein the reinforcing bar tip detecting member has a scale indicating a distance between the tip of the screw reinforcing bar and a central axis of the grout injection hole.   The reinforcing bar interval measuring jig according to any one of claims 1 to 3, wherein the grout injection hole is provided by machining. In the reinforcing bar interval measuring method for measuring the interval between the ends of the screw reinforcing bars in the internal cavity of the coupler after screwed reinforcing bars from the openings on both sides of the coupler, a reinforcing bar tip detecting member is provided on the coupler. The upper end of the reinforcing bar tip detecting member is left outside the coupler by inserting it into the inner cavity of the coupler through the grout injection hole, and the reinforcing bar tip detecting member is in contact with the upper and lower edges of the grout injection hole. Then, the insertion direction adjusting member mounted on the upper end of the reinforcing bar tip detection member is used to adjust the insertion direction of the reinforcing bar tip detection member to form the central axis of the coupler and the central axis of the grout injection hole. The tip of one of the screw rebars is inserted by inserting the reinforcing bar tip detecting member into a plane and detecting the tip of one of the screw reinforcing bars at the lower end of the reinforcing bar tip detecting member. The grout distance between the central axis of the injection hole L _A (mm) of measured, then said insertion direction adjusting member is rotated 180 ° the reinforcing bar tip detection member with the other of the tip of the screw rebar and A distance L _B (mm) between the other tip of the screw rebar and the central axis of the grout injection hole is detected, and the sum of L _A and L _B is calculated. Rebar interval measurement method.   The linear reinforcing rod having an inclination angle with respect to the central axis of the grout injection hole or a curved arc or parabolic wire is used as the reinforcing bar tip detection member. Rebar spacing measurement method.   The reinforcing bar interval measuring method according to claim 5 or 6, wherein a scale indicating a distance between the tip of the screw reinforcing bar and a central axis of the grout injection hole is provided on the reinforcing bar front end detection member.   The method for measuring a spacing between reinforcing bars according to any one of claims 5 to 7, wherein the grout injection hole is provided by machining.

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