JP3113812U - Clamp bracket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reliably prevent a nut from being detached from a bolt when the nut is loosened with an automatic fastener, and to tighten firmly while preventing the removal of this nut using a normal nut. An object of the present invention is to provide a clamp fitting that can be mass-produced at low cost and can be used for a long period of time.
In a clamp fitting provided with a bolt 7 and a nut 12 for fastening and fixing clamp bodies 2 and 3 for connecting pipes and plate members, in order to release the bolt 7 and to keep the effective bolt length, A locking step portion 14 is formed on the tip end side of the nut 12, while the tip end of the bolt 7 forms a retaining portion 9 for retaining the nut 12, and the retaining step portion 14 is engaged with the retaining step portion 14. This is a clamp fitting in which the nut 12 is prevented from coming off from the tip of the bolt 7 by the rotational torque of the automatic fastener.
[Selection] Figure 1

Description

  The present invention relates to a clamp fitting for constructing a pipe framework for holding a surrounding temporary enclosure panel such as a construction site, or for fastening a pipe for scaffolding or other pipe fastening.

Conventionally, for example, a pipe is framed by connecting pipes or pipes and H-shaped steel etc. via a clamp, and a temporary enclosure is constructed by hanging a panel on this pipe via a hook. Some pipes for scaffolding are fastened with clamp metal fittings.
Examples of this type of clamp include a clamp body having an arc recess corresponding to the outer periphery of the steel pipe, a clamp lid pivotally supported by the clamp body, and a steel pipe interposed between the clamp body and the clamp lid. There is a steel pipe clamp in which a steel pipe is fastened by screwing a normal nut to a tightening bolt in a sandwiched state (see, for example, Patent Document 1). When removing this steel pipe clamp from the steel pipe, for example, you can loosen the nut by loosening the nut using a manual wrench, and remove the clamp body by removing the clamp body from the clamp lid. It becomes.

When removing such a clamp, there is a drawback such as the nut being completely removed from the bolt and falling, so that a part of the thread of the bolt, for example, the front end of the bolt is crushed with a cutting tool to engage the nut. There is a clamp to stop.
In addition, the applicant of the present application has proposed a clamp fitting in which a separation preventing portion where the nut cannot be detached from the bolt is provided at the end of the special nut so that the nut is not detached from the bolt (see Patent Document 2). .

JP-A-10-102765 JP 2000-320507 A

  The steel pipe clamp of Patent Document 1 may be easily dropped from the bolt when the nut is tightened. In order to prevent this, there is a clamp that crushes the thread of the bolt. In this case, a crushing process is provided. Since the tip end side cannot serve as a bolt screwing part from the part where it was cut, the effective bolt length is shorter than when no crushing process is provided. Since the effective bolt length is a predetermined length necessary for clamping the pipe with the clamp, if the crushing process is provided in the clamp of Patent Document 1, the pipe may not be fastened. Further, when a bolt that is newly formed by crushing is to be provided, it is necessary to provide a crushing margin in advance and increase the total bolt length in anticipation of the effective bolt length being shortened. Thus, when it is going to crush a screw thread and to acquire the fall prevention effect, the bolt from which length differs is required.

  The clamp fitting of Patent Document 2 uses a nut having a special shape in which a cylindrical portion is extended from a tightening portion. At the time of tightening, the nut cylindrical portion is positioned in a tightening groove portion of a tightening piece, thereby enabling tightening. The effective bolt length can be maintained.

  When providing the nut removal prevention part as described above, the nut is not only used to loosen the nut with a manual wrench, but also when the nut is loosened with an automatic tightening tool with a large rotational torque such as an automatic wrench or electric ratchet. There is a need to avoid inadvertent removal. When the nut comes off the bolt, it must be discarded, in which case the entire clamp fitting is discarded. In order to prevent this, it is necessary to surely prevent dropping.

  The present invention was developed based on the clamp fitting previously proposed by the applicant of the present invention. The purpose of the present invention is to ensure that the nut is detached from the bolt when the nut is loosened with an automatic fastener. An object of the present invention is to provide a clamp fitting that can be used for a long period of time and can be mass-produced at a low cost, and can be tightened firmly while preventing the nut from being removed using a normal nut.

  In order to achieve the above-mentioned object, the invention according to claim 1 is a clamp fitting provided with a bolt and a nut for fastening and fixing a clamp body for connecting a pipe or a plate material. To maintain the length, a locking step is formed on the tip of the nut. On the other hand, the tip of the bolt forms a retaining portion for retaining the nut so that the retaining portion is engaged with the locking step. This is a clamp fitting that prevents the nut from coming off from the tip of the bolt with the rotational torque of the automatic fastener.

  The invention according to claim 2 is a clamp fitting in which the locking step portion is formed by subjecting a screw hole portion of the nut to a counterbore process having a predetermined diameter.

  The invention according to claim 3 is the clamp fitting in which the retaining portion is an annular diameter-enlarged portion that is pushed and widened from the hollow portion side formed on the tip end side of the bolt.

  The invention according to claim 4 is a clamp fitting in which the retaining portion is formed by crushing the outer end portion of the bolt with a press.

  According to a fifth aspect of the present invention, there is provided a clamp fitting provided with a bolt and a nut for fastening and fixing a clamp body for connecting a pipe or a plate material, and the tip of the bolt forms a retaining portion such as caulking for retaining the nut. This is a clamp fitting that prevents the nut from coming off the tip of the bolt due to the rotational torque of the automatic fastener.

According to the device according to claim 1 or claim 5, even when the nut is loosened with an automatic fastener, the nut can be reliably prevented from being detached from the bolt. It is a clamp fitting that can firmly tighten and fix a pipe or the like while maintaining an effective bolt length by performing simple processing. Therefore, it can be mass-produced at low cost and can be used for a long time.
In addition, according to the invention according to claim 1, since the effective bolt length can be maintained without extending the bolt length, the bolt length can be shortened and stored in the clamp fitting body together with the nut. It is a clamp metal fitting that can be made compact in, for example. For this reason, it is a clamp metal fitting which is excellent in storability and transportability, and can prevent damage to the bolt which is a movable part.

  The invention according to claim 2 and claim 3 is a clamp fitting capable of providing a nut retaining process while maintaining an effective bolt length by performing a simple process using normal bolts and nuts. .

  The invention according to claim 4 is a clamp fitting that can be easily formed into the same shape and the same dimensions by plastic working, and can mass-produce highly accurate products efficiently.

A preferred embodiment of a clamp fitting according to the present invention will be described with reference to the drawings.
In FIG. 1, reference numeral 1 denotes a clamp metal body provided with a pair of clamp bodies 2 and 3 for connecting pipes (not shown). The clamp bodies 2 and 3 are fixed by fixing members 15 such as a plurality of rivets. The clamp bodies 2 and 3 can fix a pipe or the like (not shown) in a substantially orthogonal direction, but may be provided in such a direction that can be fixed in a substantially parallel state. In addition, a clamp body having a shape capable of clamping a plate material member such as an H-shaped steel (not shown) may be provided on one side of the clamp metal body. The shape may be appropriately changed according to the above.
At one end of the clamp bodies 2 and 3 in the present embodiment, a fastening piece 4 for fixing a pipe or the like is rotatably provided on the shaft attachment portion 6 by a shaft attachment rod 5. A fastening groove 4 a is provided on the distal end side of the fastening piece 4.

The bolt 7 shown in FIGS. 2 and 3 is pivotally attached to the shaft fitting portions 2a and 3a of the clamp bodies 2 and 3 in the mounting holes 7a, respectively, and has a male screw portion 8 on the outer peripheral side. ing.
Reference numeral 9 denotes a retaining portion (expanded portion) provided by expanding the male screw portion 8 on the tip end side of the bolt 7. In this example, the retaining portion 9 is provided after the nut 12 is screwed. I am doing so.
The retaining portion 9 is screwed in the direction of loosening the nut 12 by using an automatic tightening tool (not shown) for tightening or loosening a nut such as an automatic wrench or electric ratchet in the clamp metal body 1. The nut 12 is used to prevent the nut 12 from coming off from the tip of the bolt 7 with the rotational torque of the automatic fastener, and has a diameter that is larger than the female thread 13 of the nut 12. Forming. The retaining portion 9 may be configured such that the end of the screw is crushed by crimping the tip of the bolt 7.

Here, processing of the retaining portion 9 will be described. In FIG. 3, first, the hollow portion 10 is first processed into a hollow shape on the front end side of the bolt 7 by a processing means such as forging. The hollow portion 10 is provided in a shape having an inclined slope portion 11, and when the force is applied in the arrow direction from the tip end side of the bolt 7 by the slope portion 11, the bolt tip end side is provided so that the diameter of the bolt can be expanded outward. .
After the nut 12 is screwed onto the bolt 7, when a pressing force is applied from the tip portion of the bolt 7 by a press machine (not shown), the annular retaining portion 9 is formed by being spread from the hollow portion 10 side.
Further, the retaining portion 9 may be processed at a time. For example, the retaining portion 9 and the hollow portion 10 can be formed simultaneously by pressing them with a press.
In any case, it is desirable to form the edge portion 9a of the retaining portion 9 in a round shape to improve safety.

As shown in FIG. 4, the nut 12 has a female thread portion 13 that is screwed into the threaded portion 8. By tightening or loosening the nut 12, the bolt 7 and the nut are secured to the fastening groove portion 4a. 12 is fixed so that the clamp body 2 or 3 can be tightened with a pipe or the like. At the lower part of the nut 12, an annularly enlarged ridge 12 a is provided, and when tightening, the lower surface side of the ridge 12 a abuts the tightening piece 4 to achieve a stable tightening state. The protruding portion 12a can be omitted.
The locking step portion 14 is formed by subjecting a screw hole portion of the nut 12 to a counterbore with a predetermined diameter by a counterbore machine (not shown). By providing the locking step portion 14 in this way, when the nut 12 is screwed out with respect to the bolt 7, the retaining portion 9 can be engaged with the locking step portion 14 and screwed out to the limit. Therefore, the escape of the retaining portion 9 which is a retaining processing portion of the bolt 7 can be held. At this time, the bolt effective length L of the bolt 7 is maintained. The bolt 7 is preferably provided with a length that can be accommodated in the clamp metal body 1 when the nut 12 is screwed out to the maximum. The nut 12 may be a general-purpose nut that does not have the locking step portion 14 so that the nut 12 does not come off from the retaining portion 9 that has been crimped.

Next, the operation in the above embodiment will be described.
When the nut 12 screwed to the bolt 7 is loosened by the automatic fastener, the retaining portion 9 is engaged with the locking step portion 14 when the nut 12 is positioned near the outer end of the bolt 7. Even if the rotational torque of the automatic fastener is further applied to the nut 12 from this state, the retaining portion 9 has a larger diameter than the female screw 13a of the nut 12, so that it is locked to the edge of the female screw portion 13. Stop in state. Therefore, it is possible to resist the rotational torque of the automatic fastener, and it is possible to reliably prevent the nut 12 from being accidentally pulled out from the bolt 7. At this time, since the effective length L of the bolt can be maintained at the same length without changing compared with the case where the locking step portion 14 and the retaining portion 9 are not provided, the pipe can be securely fastened. it can.
In addition, by adjusting the processing conditions of the locking step portion 14 and the retaining portion 9, it was possible to obtain a slip-off torque of the nut 12 of about 120 kgf. On the other hand, the removal torque of the nut of the conventional clamp in which a part of the screw thread of the bolt is crushed by the cutting tool is about 50 kgf, and the removal strength of the clamp fitting of the present embodiment can be greatly improved compared to the conventional case. .

  FIG. 5 shows another example of the clamp fitting according to the present invention. In this clamp fitting, the outer end portion of the bolt 20 is crushed by a press machine, and the nut 23 is prevented from coming off at this portion of the bolt 20. An annular retaining portion 22 is provided.

  FIG. 6 shows a state of crushing when the bolt 20 of FIG. 5 is pressed by the press member 30 of the press machine. The press member 30 has a groove portion 31, and the groove portion 31 is deformed so that the screw thread at the outer end portion of the bolt 20 is pushed down, and the retaining portion 22 is formed at the portion of the male screw portion 21.

FIG. 7 shows an example in which the outer end portion of the male threaded portion 27 of the bolt 26 is crushed by a pressing member 32 having a shape different from that in FIG. As shown in the drawing, the pressing member 32 has a semicircular groove 33 having a substantially semicircular cross section. When the semicircular groove 33 is pressed against the outer end of the bolt 26, the outer end portion of the bolt 26 is semicircular. The retaining portion 28 that is crushed toward the outer peripheral side of the groove 33 and is expanded in an annular shape as shown in the figure is formed.
The retaining portion 28 is not exposed in the rearward direction of the bolt 26 because the tip portion is crushed when pressed and bulges in the direction of the semicircular groove 33 and deforms into a curl shape.

Further, the retaining portion is not limited to the above-described example as long as the nut does not fall off due to the rotational torque of the automatic fastener, and the retaining portion is not limited to the above-described technical idea. It can be formed in various shapes.
In FIG. 8, a general-purpose nut is used as the nut 35, and the retaining portion 9 for retaining the nut 35 is formed by caulking or the like at the tip of the bolt 7. In the figure, the same parts as those of the clamp fitting of FIG. 2 are denoted by the same reference numerals.
Here, the effective length of the bolt of the clamp fitting in FIG. 9 is set to 68 mm, torque is applied to the nut 35 in the removal direction, and the removal torque test is the torque when the nut 35 comes out from the front end side of the bolt 7. The results are shown in Table 1.

Assuming that the safe removal torque is 13.0 N · m or more, all the samples exceeded this safety value, and the safety was confirmed from the test results.
As described above, even when the nut 35 is a general-purpose nut, it can be prevented from coming off by appropriate means such as caulking. In this case as well, the bolt 7 is securely attached when rotational torque is applied from the automatic fastener. Pull-out from the tip side can be prevented.

  The present invention can be applied to various metal fittings and jigs as a structure for preventing nuts from falling off bolts. Furthermore, if the bolts and nuts are screwed together, the present invention can be widely applied to general screwing structures. Can be applied.

It is the perspective view which showed an example of the clamp metal fitting in this invention. It is a partially notched enlarged front view showing a bolt and nut in a retaining state. FIG. 3 is an enlarged front view partially cut away showing the bolt in FIG. 2. (A) is a half-enlarged sectional view of a nut. (B) is an enlarged plan view of a nut. It is a partially notched enlarged front view showing another example of the clamp fitting in the present invention. FIG. 6 is an enlarged front view partially cut away showing a processed state of the bolt of FIG. 5. It is a partially notched enlarged front view showing another example of the processing state of the bolt. It is a partially notched enlarged front view showing still another example of the clamp fitting in the present invention.

Explanation of symbols

1 Clamp metal body 2, 3 Clamp body 7 Bolt 8 Male thread 9 Retaining part (expanded part)
10 Hollow part 12 Nut 13 Female thread part 14 Locking step part

Claims (5)

  For clamp fittings with bolts and nuts that fasten and clamp clamp bodies that connect pipes and plate materials, the nuts are locked to the end of the nuts in order to release the bolts and keep the effective bolt length. On the other hand, the tip of the bolt forms a retaining portion for retaining the nut, and the retaining portion is engaged with the retaining step portion so that the nut is rotated by the rotational torque of the automatic fastener. Clamp metal fitting that prevents it from coming out of the tip of the bolt.   The clamp fitting according to claim 1, wherein the locking step portion is formed by subjecting a screw hole portion of a nut to a counterbore process having a predetermined diameter.   The clamp fitting according to claim 1 or 2, wherein the retaining portion is an annular diameter-enlarged portion that is pushed from the hollow portion side formed on the tip end side of the bolt.   The clamp metal fitting according to any one of claims 1 to 3, wherein the retaining portion is formed by crushing an outer end portion of a bolt with a press. In clamp fittings with bolts and nuts that fasten and clamp clamp bodies that connect pipes and plate materials, the bolt ends form a retaining part such as caulking for retaining the nuts to rotate the automatic fastener. A clamp fitting that prevents the nut from coming off the tip of the bolt by torque.

Images