JP2002295417A - Clamp fitment and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of a slide during the use of a pipe and a clamp fitment and secure safety and reduce weight by a method where the strength (hardness) of at least a body of a steel pipe, hardness of which is increased, and a clamp fitment is made equal to each other. SOLUTION: In a clamp fitment 10 where body 1 made of a steel and a cover 2 are pivotally secured and a steel pipe 9 for being fastened is fastened by the body 1, the cover 2, a bolt 4, and a nut 6, the strength of the body 1 is adjusted to a level approximately equal to the strength of the pipe 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clamp used for fastening a pipe frame or a scaffold pipe for holding a temporary enclosure panel used for construction work and the like, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Clamp fittings of this type are widely used for the framework of steel pipes to be tied and scaffold pipes.
Normally, carbon steel pipes for general structures are used, and the clamps are also usually JIS specified for hot-rolled mild steel sheets and steel strips.
Used according to standards. However, recently, due to the demand for weight reduction, a high-strength steel which has been made lighter than a normal steel pipe and has improved strength compared to a conventional product has come to be used.

[0003]

A conventional clamp and a commonly used steel pipe can be used for fastening a pipe for scaffolding if the specified value of the Temporary Industry Association certified standard is cleared. .

[0004] However, when a conventional clamp is used for a new product steel pipe formed of high-strength steel, abnormal sliding occurs during use due to the difference in strength (hardness) between the new product pipe and the clamp. Is dangerous because
Scaffolding pipes with heavy loads were extremely dangerous.

The present invention has been developed in order to solve such a drawback. By making the strength of a new product pipe and a clamp fitting equal, it is possible to prevent slippage during use and to improve safety and safety. The purpose is to reduce the weight.

[0006]

In order to achieve the above object, according to the first aspect of the present invention, a steel body and a lid are provided so as to be pivotally attached, and the body and the lid are connected by bolts and nuts. A metal fitting for tightening a steel pipe, wherein the strength of at least the main body is substantially equal to the strength (hardness) of the pipe.

According to a second aspect of the present invention, a steel pipe to be tied is formed of high-tensile steel, and the main body is subjected to a heat treatment so that the strength of the steel pipe and the strength of the high-tensile steel are substantially equal to each other. It was done.

According to a third aspect of the present invention, there is provided a method of manufacturing a clamp fitting for fastening a steel pipe to be fastened to a steel pipe with a bolt and a nut. Process, such as punching or molding, a heat treatment process to increase the strength (hardness) by applying heat treatment to at least the main body of the intermediate product after this process, and plating, caulking, etc. This is a method of manufacturing a clamp, which is manufactured through a processing step.

According to a fourth aspect of the present invention, in the heat treatment step, at least the main body is hardened by rapid cooling after heat treatment.

[0010]

FIG. 1 is a perspective view showing an example of a clamp fitting according to the present invention. FIG. 2 is a perspective view showing the clamp fitting 10 in a frame of a pipe 9 for holding a panel 11 for temporary enclosure. FIG. Although not shown, this clamp fitting is also used for a clamp for fastening a scaffold pipe.

In FIG. 1, reference numeral 1 denotes a main body made of a steel material. The main body 1 has a pipe narrowing surface 2a on an inner peripheral surface via a pin 3, and a lid 2 for transmitting a tightening force to the main body 1. The main body 1 is provided with a pipe support portion 1a, and these pipe contact surfaces are smoothly finished. Further, a bolt 4 is rotatably provided at one end of the main body 1 via a pin 5, and the bolt 4 is
The upper portion of the lid 2 is further tightened and fixed with a nut 6 to tighten the steel pipe 9.

The main body 1 includes an orthogonal clamp shown in FIG. 1, that is, a clamp in which the crossing angle of the steel pipe is held at 90 ° and a free clamp in which the crossing angle of the steel pipe can be freely changed. In this example, the screws 8 are used to fix the main body 1, 1
The orthogonal clamp to which the comrades were fixed is shown.

Next, the manufacturing process of the clamp according to the present invention will be described. In this example, the main body 1 and the lid 2 are formed by punching a steel material of a JIS G 3131 hot-rolled mild steel sheet, and further performing a forming process to form an intermediate product. Next, in this example, of the intermediate product, the main body 1 is subjected to a heat treatment step to increase the strength (hardness). As a preferred example, specifically, the main body 1 is heated to 800 to 1000 ° C. by a heating means such as a burner.
By subjecting the main body 1 to immersion in water (about 15 ° C.) and quenching, the main body 1 undergoes martensitic transformation and is hardened, thereby increasing the hardness. As another example, depending on the method of carburizing and quenching, a quenching temperature in the range of 800 to 900 ° C., preferably a quenching temperature of about 880 ° C.
Quenching times in the range of 00 to 150 minutes, preferably about 15 minutes
The heat treatment step is performed by a quenching time of 0 minutes.

The above example illustrates an embodiment of the present invention and, in addition, at a quenching temperature of about
A quenching time of about 0 minutes may be performed, and these are optional according to the embodiment of the present invention, and a suitable heat treatment means is appropriately selected to improve the strength and hardness of the clamp, especially the main body 1. Like that.

Further, the intermediate product having undergone this heat treatment step is:
By performing a plating process and a caulking process, the clamp fitting and the like shown in FIG. 1 are manufactured. As described above, the strength (hardness) of the main body 1 is increased so as to be equal to the hardness of the pipe 9, and the hardness difference between the main body 1 and the pipe 9 is eliminated or reduced, so that the frictional resistance is increased and the slip between the two is improved. Has been lost.

Table 1 shows the results of an experiment conducted on the comparative example in this example within the range of the standard value of the temporary industry association certification standard.

[Table 1] In this case, the amount of change is the torque 3.4 indicated by the clamp.
The maximum load is 10 mm or less when 3 KN · cm and 4.41 KN · cm, and the maximum value of the load when the maximum load is 4.41 KN · cm and the load is applied is the orthogonal type. It is necessary to be 14.7 KN or more and to be 9.81 KN or more for a universal type.

Within this range, as shown in Table 1,
Although the conventional clamp and the conventional steel pipe are within the range of the standard value, the new pipe and the conventional clamp were rejected as a result of the implementation. In addition, in the experimental examples of the new product and the product of the present invention, or the ordinary steel pipe and the product of the present invention, the judgment result of passing was also obtained.

In the clamp, the Vickers hardness of the conventional product is 160, while the clamp of the present invention is 490, and it is confirmed that the hardness is sufficiently improved as compared with the conventional product. Was.

[0019]

As is clear from the above, according to the present invention, even when the clamp is tied to a new steel pipe, accidents such as dropping due to slippage during use are surely prevented. To provide a practical clamp structure and a method for manufacturing the same, which can not only improve the durability and improve the durability but also contribute to the weight reduction of the entire steel pipe. Became possible.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a clamp according to the present invention.

FIG. 2 is an explanatory view showing an example in which the clamp according to the present invention is used for a pipe framework to hold a temporary surrounding panel.

FIG. 3 is a block diagram showing an assembling process of a clamp according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main body (clamp fitting) 2 Lid 4 Bolt 6 Nut 9 Steel pipe 10 Clamp fitting

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3J022 DA15 DA16 EA38 EB14 EC17 EC22 ED23 FA02 FB06 FB07 FB12 GA03 GA12 GB22 3J039 AA06 BB01 CA01 CA03 GA03 GA04 MA03 MA10

Claims (4)

[Claims] 1. A steel material body and a lid are provided so as to be freely pivotable,
A clamp fitting for fastening a steel pipe to be fastened with a body and a lid using bolts and nuts, wherein the strength of the body is at least substantially equal to the strength (hardness) of the pipe. 2. The steel pipe according to claim 1, wherein said steel pipe to be tied is formed of high-tensile steel, and said body is subjected to a heat treatment so that these strengths and said high-tensile steel have substantially the same level. Clamp fitting described. 3. A steel body and a lid are pivotally mounted on the main body,
In the method of manufacturing a clamp fitting for fastening a steel pipe to be fastened with bolts and nuts to the main body and the lid, there is a working process in which a steel material is subjected to a punching process, a forming process, etc. A method of manufacturing a clamp fitting, comprising: a heat treatment step of increasing the strength (hardness) by applying heat treatment to at least a main body; and a clamp fitting through a treatment step such as plating or caulking. 4. The method according to claim 3, wherein in the heat treatment step, at least the main body is heat-treated and then rapidly cooled to be cured.