JP2015129556A - Clamp metal fitting and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide clamp metal fittings that can have a nut lock part molded at a low cost and eliminate a trouble such that a fixing nut becomes hard to separate from the nut lock part.SOLUTION: A nut lock part 5 which swells is formed by collapsing one end part of a fastening bolt 3. The nut lock part 5 is formed to cover screw threads 3A at an end of the fastening bolt 3. A fixing nut 4 is configured not to come out of the one end part of the fastening bolt 3. A hollow part 5A is formed in one end part of the fastening bolt 3. The hollow part 5A is spread outward to form a swelling part 5B. The swelling part 5B is formed to cover screw threads 3A at the end of the fastening bolt 3. The fixing nut 4 has a lock step part 4A. When the fixing nut 4 is disengaged, the nut lock part 5 is locked in the lock step part 4A.

Description

  The present invention relates to a clamp fitting that is used when connecting a pipe or the like for a temporary scaffold, and more particularly to a clamp fitting that prevents a nut from falling off when a fixing nut is loosened with an electric tool, and a method for manufacturing the same.

  This type of clamp fitting is composed of a clamp body and a clamp lid. A clamping pipe or the like is sandwiched between the clamp body and the clamp lid, and a clamping bolt connected to the clamp body in a swingable manner is attached to the clamp lid. The clamp lid is fastened and connected with a fixing nut that is pre-screwed to the fastening bolt. On the other hand, when removing the connected clamp metal fittings, for example, the fixing nut is loosened using a manual wrench or an electric tool, and the tightening bolt locked to the clamp lid is removed.

  When such a clamp fitting is removed, the fixing nut may fall off from the tightening bolt. Therefore, conventionally, a clamp has been proposed in which a nut stopper is provided at one end of the tightening bolt to prevent the fixed nut from falling off (Patent Document 1). According to this clamp, the bulging portion is formed by crushing the peripheral edge of the one end portion of the fastening bolt toward the axial center of the bolt, and this bulging portion is used as a nut stopper.

Japanese Patent No. 4717053

  However, the nut stopper described in Patent Document 1 forms a bulging portion by crushing the peripheral edge of one end of the tightening bolt toward the axis of the bolt, and the nut fixing portion is formed by this bulging portion. To form. For this purpose, it is necessary to use a press die with a spherical convex part at the center and to perform precise processing such as crushing in a state where the center of the convex part is aligned with the center of the fastening bolt. It was. As a result, there is a problem that requires a lot of cost and labor for forming the nut stopper, such as requiring high-precision processing equipment and a technically precise pressing process.

  Moreover, when the fixing nut is loosened with the electric tool, the nut fixing portion formed at the tip of the tightening bolt may bite into the opening of the fixing nut and may not be separated. That is, since the nut stopper is formed at a portion that gradually bulges from the outer surface of the tightening bolt, a taper is formed from the portion where this bulge starts to the portion that bulges greatly. For this reason, the taper of the nut stopper is easily aligned with the opening of the fixing nut, and when the fixing nut is forcibly rotated with an electric tool when loosening the fixing nut, the nut is inserted into the opening of the fixing nut. There is a possibility that the taper of the stopper is forcibly fitted, and the fixing nut cannot be separated from the nut stopper.

  Therefore, the present invention has been devised to solve the above-mentioned problems, and a nut stopper formed at the tip of the tightening bolt can be formed at low cost with simple equipment, and the fixing nut can be formed from the nut stopper. An object of the present invention is to provide a clamp fitting that eliminates the inconvenience of being difficult to separate and a method for manufacturing the same.

  In order to achieve the above-mentioned object, the first means in the present invention includes a clamp body 1 in which a fastening bolt 3 is swingably provided, a clamp lid 2 that is swingably connected to the clamp body 1, In a clamp fitting provided with a fixing nut 4 screwed to the clamping bolt 3 and locked to the clamp lid 2, one end portion of the clamping bolt 3 is crushed and the thread 3 </ b> A at one end portion of the clamping bolt 3 is expanded. A nut stopper 5 that is bent so as to wrap from the outside is formed, and the fixing nut 4 that is locked to the clamp lid 2 is released from one end of the tightening bolt 3 when the fixing nut 4 is released with an electric tool. It is in the configuration.

  In the second means, the nut fixing portion 5 is formed by forming the annular bulging portion 5B by expanding the hollow portion 5A formed at one end of the tightening bolt 3 to the outside. It is formed so as to wrap around the thread 3A at the end of the tightening bolt 3.

  The third means is to form a locking step portion 4A having a concave cross section on the surface of the fixed nut 4 that contacts the nut stopper 5 and when the fixed nut 4 is released, the nut in the locking step portion 4A. That is, the stopper 5 is configured to be locked.

  The fourth means is a clamp body 1 in which a fastening bolt 3 is swingably provided, a clamp lid 2 that is swingably connected to the clamp body 1, and a clamp lid that is screwed to the fastening bolt 3. In the manufacturing method of the clamp bolt for the clamp fitting provided with the fixing nut 4 to be locked to 2, the step of forming the hollow portion 5A at one end of the clamp bolt 3, and the first press die P1 A step of expanding the hollow portion 5A from above 5A into a disc shape and forming a bulging portion 5B in which the peripheral edge of the disc is inclined downward, and the circumference of the bulging portion 5B by the second press die P2. And a step of pressing the portion toward the tightening bolt 3 to form a nut stopper 5 that wraps the screw thread 3A of the tightening bolt 3.

  According to the first aspect of the present invention, the end portion of the tightening bolt 3 is crushed to form the nut stopper portion 5 that bulges so as to cover the thread 3A at the end portion of the tightening bolt 3. High-precision processing equipment used when forming the bulging part that is crushed toward the bolt axis, and precise pressing processes are no longer necessary, and can be manufactured at low cost with ordinary press dies. It becomes possible.

  In addition, since the nut stopper 5 bulges so as to cover the thread 3A at the end of the tightening bolt 3, the nut stopper 5 is formed with a taper continuous from the thread to the nut stopper as in the prior art. There is nothing. Therefore, even when a general nut is used as the fixing nut 4, the conventional problem that the taper of the nut stopper is forcibly fitted to the opening of the fixing nut and cannot be separated is solved.

  As in claim 2, the nut fixing portion 5 is configured to form an annular bulging portion 5 </ b> B by expanding the hollow portion 5 </ b> A formed at one end of the tightening bolt 3 to the outside, and the bulging portion 5 </ b> B By forming the screw 3 </ b> A at the end of the tightening bolt 3 so as to wrap, the screw 3 </ b> A formed at one end of the tightening bolt 3 is covered with the nut stopper 5. Therefore, it is safe even if an operator touches one end portion of the tightening bolt 3, and safety during transportation or work can be improved.

  According to the third aspect of the present invention, the locking nut 4A is formed in the fixed nut 4 so as to have a concave cross section, and when the fixed nut 4 is released, the nut stopper 5 is locked in the locking step 4A. Moreover, the forced fitting of the nut stopper 5 can be prevented more reliably. As a result, even if the nut stopper 5 is locked in the locking step 4A by the strong torque of the electric tool, the nut stopper 5 is not forcibly fitted into the opening of the fixed nut 4.

  The step of forming the hollow portion 5A at one end of the fastening bolt 3 as in claim 4 and the first press mold P1 pushes the hollow portion 5A from above the hollow portion 5A into a disk shape. A step of forming the bulging portion 5B whose peripheral edge is inclined downward, and the second press die P2 presses the circumferential portion of the bulging portion 5B in the direction of the tightening bolt 3 to tighten the bolt 3 And the step of forming the nut stopper 5 that wraps around the screw thread 3A, the nut stopper 5 can be formed with a simple operation.

  Moreover, as in the conventional manufacturing method, a press mold having a spherical convex portion at the center is used, and the center of the convex portion is crushed in a state where the axis of the fastening bolt is aligned. Since precise processing and high-precision processing equipment are not required, inexpensive manufacturing is possible.

It is the front view which showed an example of the clamp metal fittings in this invention. It is sectional drawing which shows the latching step part of this invention. It is sectional drawing which shows the nut stopper part of this invention. (A), (b) is a schematic explanatory drawing which forms a bulging part from a hollow part. (A), (b) is a schematic explanatory drawing which forms a nut stop part in a bulging part.

  According to the present invention, the nut stop formed on the tip of the tightening bolt can be formed with simple equipment at low cost, and the initial purpose of eliminating the inconvenience that the fixed nut is difficult to be separated from the nut stop is achieved. .

  Examples of the present invention will be described below. The clamp metal fitting according to the present invention includes a clamp body 1, a clamp lid 2, a fastening bolt 3, and a fixing nut 4 (see FIG. 1). That is, the clamp body 1 is provided so as to be swingable so that the clamp lid 2 and the fastening bolt 3 face each other. An engaging portion 2A having a groove is formed at the tip of the clamp lid 2, and the tightening bolt 3 is fitted into the groove of the engaging portion 2A. A fixing nut 4 is screwed to the tightening bolt 3 in advance. The fixing nut 4 is locked to the locking portion 2A of the clamp lid 2 and fastened to fix a temporary scaffolding pipe or the like. is there.

  In the example shown in the figure, a pair of clamp fittings are rotatably connected. However, the clamp fittings can also be attached to an orthogonal clamp in which a pair of clamp fittings are fixed in an orthogonal state or to the end of a wall connecting pipe. The clamp metal fittings used for every application, such as the clamp metal fittings to be mounted, are targeted.

  In the present invention, a nut retaining portion 5 is formed at one end of the tightening bolt 3, and the nut retaining portion 5 is configured to cover the thread 3A at the end of the tightening bolt 3 (see FIG. 2). . The fixing nut 4 is configured not to come off from one end of the tightening bolt 3 when the fixing nut 4 locked to the clamp lid 2 is released by an electric tool such as an impact wrench. This nut stopper 5 is formed so as to wrap the nearest screw thread 3A from the outside.

  The fixing nut 4 of the present invention uses a normal nut as the fixing nut 4. Moreover, the forced fitting of the nut stopper 5 can be more reliably prevented by using the fixed nut 4 formed with the locking step 4A (see FIG. 3). 4 A of this latching step parts are formed in the concave cross section in the surface contact | abutted to the nut stop part 5 of the fixed nut 4. As shown in FIG. And when releasing the fixed nut 4 with an electric tool, it forms so that the nut stop part 5 may be latched by the bottom part in this latching step part 4A. By forming the locking step portion 4A, the opening portion of a normal nut in which the conventional nut stopper is forcibly fitted is eliminated.

  Next, a manufacturing method for forming the nut stopper 5 on the fastening bolt 3 will be described. In the first step, a hollow portion 5A is formed at one end of the tightening bolt 3 (see FIG. 4 (A)). In the second step, the hollow portion 5A is spread outwardly from above the hollow portion 5A using the first press die P1 to form a disk-shaped bulged portion 5B (see FIG. 7B). ). At this time, the peripheral edge of the bulging portion 5B is formed to be slightly inclined downward. In the third step, the second press die P2 is used (see FIG. 5 (a)), the circumferential portion of the bulging portion 5B is pressed toward the tightening bolt 3, and the bulging portion 5B is pressed. Then, the nut 3 is bent so as to wrap around the screw thread 3A of the tightening bolt 3. The distal end of the nut stopper 5 is formed in advance in the second step so that the peripheral edge of the bulging portion 5B is formed obliquely downward. When the bulging portion 5B is further bent in the third step, the bulging portion 5B The tip of the portion 5B is bent so as to wrap the screw thread 3A from the outside.

  In addition, each structure of this invention is not limited to the example of illustration, It is arbitrary in the range which does not change the summary of this invention, such as the nut stop part 5, the 1st press die P1, and the 2nd press die P2. It is possible to change the configuration.

P1 1st press die P2 2nd press die 1 Clamp body 2 Clamp lid 2A Locking part 3 Tightening bolt 3A Screw thread 4 Fixing nut 4A Locking step part 5 Nut stopper part 5A Hollow part 5B Swelling part

Claims (4)

  A clamp having a clamp body in which a fastening bolt is swingably provided, a clamp lid that is swingably connected to the clamp body, and a fixing nut that is screwed to the clamp bolt and locked to the clamp lid In the bracket, one end of the tightening bolt is crushed to form a nut stopper that is bent so as to wrap the screw thread of the one end of the tightening bolt from the outside, and the fixed nut that is locked to the clamp lid is an electric tool A clamp metal fitting that is configured so that the fixing nut does not come off from one end of the tightening bolt when releasing with.   The nut fixing portion pushes and expands a hollow portion formed at one end portion of the tightening bolt outward to form an annular bulge portion, and the bulge portion wraps the screw thread at the end of the tightening bolt. The clamp metal fitting according to claim 1 formed as described above.   A locking step portion having a concave cross section is formed on a surface of the fixing nut that contacts the nut stopping portion, and the nut stopping portion is locked in the locking step portion when the fixing nut is released. The clamp metal fitting according to 1.   A clamp having a clamp body in which a fastening bolt is swingably provided, a clamp lid that is swingably connected to the clamp body, and a fixing nut that is screwed to the clamp bolt and locked to the clamp lid In the method of manufacturing a metal fitting, a step of forming a hollow portion at one end portion of the fastening bolt, and a first press mold spreads the hollow portion from above the hollow portion into a disk shape, and the peripheral edge of the disk is slanted A step of forming a bulging portion that faces downward, and a second pressing die press the circumferential portion of the bulging portion toward the tightening bolt to form a nut stopper that wraps the thread of the tightening bolt A method of manufacturing a clamp fitting, comprising:

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