JP2012091232A - Method for manufacturing connecting fixture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a connecting fixture, which can simplify a manufacturing process, has good workability, and, at the same time, can manufacture the connecting fixtures in a cost-effective manner.SOLUTION: In the method for manufacturing the connecting fixture 16, a short cylindrical projection 11 formed on a first metal material 10 is fitted into a circular hole 13 provided in a second metal material 12, and an end 14 of the projection 11 is pressed to form a diameter-expanded part 15 to connect the first metal material 10 and the second metal material 12 to each other. A slanted diameter-expanded part 63 is formed on one side of the circular hole 13. The projection 11 is inserted into the circular hole 13 so that the slanted diameter-expanded part 63 of the circular hole 13 is located in an end direction of the projection 11 to form the diameter-expanded part 15.

Description

The present invention relates to a method of manufacturing a connecting fitting suitable for a clamp fitting that joins the crossing portions of pipe struts that support a scaffold plate, for example, at a construction site.

2. Description of the Related Art Conventionally, an assembly scaffold used at a construction site is configured by connecting pipes arranged vertically and horizontally by a clamp fitting. As shown in FIG. 5A, the clamp fitting 80 has one end of a fixed member 84 and an end of a movable member 85 each provided with an arcuate pipe receiving portion 82, 83 for pinching the pipe 81. The first and second pipe fixtures 88 and 89 form a pair that can be connected to each other and the other end can be detachably fastened by fastening means 87 comprising a screw mechanism.
As shown in FIGS. 5A and 5B, each of the first and second pipe fixing tools 88 and 89 includes a connecting member (for example, a connecting member having caulking portions 90 and 91 at both ends, for example, , Pipes or rivets) 92 and connected so as to be relatively rotatable (see, for example, Patent Document 1 and Patent Document 2).

Utility Model Registration No. 2535358 Utility Model Registration No. 3089350

However, since separate connecting members 92 are used for connecting the first and second pipe fixing members 88 and 89, for example, the manufacture of the connecting member 92 and the first and second pipe fixing members 88 and 89 are used. It is necessary to attach the connecting member 92 to the. For this reason, an extra manufacturing process is needed and it becomes complicated, and workability | operativity is bad.
Further, since the connecting member 92 is required separately, the manufacturing cost for manufacturing the connecting member 92 is not economical.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a method of manufacturing a connecting metal fitting that can simplify the manufacturing process, has good workability, and can be manufactured economically.

In the manufacturing method of the connecting metal fitting according to the present invention that meets the above-described object, the short cylindrical protrusion formed on the first hardware having a thickness of T1 is formed into a circular shape formed on the second hardware having a thickness of T2. It is a manufacturing method of a fitting that fits into a hole, presses the end of the projecting portion to form an enlarged diameter portion, and rotatably connects the first hardware and the second hardware,
(1) The first die having an inner diameter of (D1) and the first punch having an outer diameter of (D1-2 × T1), which is fitted into the first die, and the pilot hole is formed. Press processing A for forming the protruding portion having a bending angle of 85 degrees or more and less than 90 degrees on the first hardware, a second die having an inner diameter of (D2), and the second die fitted into the second die A pre-processing step having a second punch with an outer diameter of (D2) and a press work B that forms the circular hole with an inner diameter of (D2) in the second hardware,
(2) a fitting process step of inserting a protrusion of the first hardware into the circular hole formed in the second hardware;
(3) A curl die having a protrusion that is in contact with the lower inner side of the protrusion of the first metal fitting in a state in which the protrusion is inserted into the circular hole, and a part of which is inserted into the inner side of the short cylindrical protrusion. And a curved caulking portion that bends the end of the protruding portion fitted into the circular hole outward, and an annular abutting portion that is outside the curved caulking portion and that approaches or abuts the second hardware when the press is completed. A caulking process step of bending the end portion of the protruding portion radially outward using a curl punch to form the enlarged diameter portion.

In the method for manufacturing a connecting metal fitting according to the present invention, an inclined diameter-enlarged portion is provided at a base portion of the second punch, and the press work B is tapered to one side of the circular hole of the second hardware. An inclined diameter-enlarged portion having an enlarged diameter is formed, and in the fitting process step, the projecting portion of the first hardware is inserted into the circular hole formed in the second hardware, and the inclined enlarged-diameter portion of the circular hole is formed. It is preferable to put in such a manner that it is in the direction of the end of the protruding portion.
In the method for manufacturing a connecting metal fitting according to the present invention, the formation of the lower hole in the first hardware in the pretreatment step includes an auxiliary punch provided at a tip portion of the first punch, and the auxiliary punch. It is preferably performed by a pair of auxiliary dies.
In the method for manufacturing a connecting metal fitting according to the present invention, each of the first metal fitting and the second metal fitting is provided with an arcuate pipe receiving portion inside, and a fixing member whose one end is rotatably connected by a pin And the movable member and the fixed member of the first and second pipe fixtures that are paired with the fixed member and screw fastening means capable of fastening the movable member in a state where the pipe is sandwiched. preferable.

The manufacturing method of the connection metal fitting of Claims 1-4 WHEREIN: The pre-processing process which forms a short cylinder-shaped protrusion part in a 1st metal fitting, and forms a circular hole in a 2nd metal hardware, and makes a protrusion part a circular hole. Since there is a fitting processing step to be inserted and a crimping processing step of bending the end portion of the protruding portion fitted in the circular hole outward in the radial direction, the first, without using a separate connecting member as in the prior art, The second hardware can be connected to be relatively rotatable. For this reason, a manufacturing process can be simplified, workability | operativity is good, and also a connection metal fitting can be manufactured economically.
In particular, in the method for manufacturing a connecting metal fitting according to claim 2, in the pretreatment step, a circular hole whose one side is enlarged in a tapered shape is formed in the second hardware, and in the fitting treatment step, a protruding portion is formed in the circular hole. Since the inclined enlarged diameter portion of the circular hole is inserted so as to be in the direction of the end of the protrusion, it is easy to bend when the end of the protrusion is bent radially outward in the caulking process, and the protrusion is The frictional resistance between the outer side and the inner side of the circular hole can be made smaller than when no inclined diameter-expanded portion is provided. Thereby, the relative rotation of the first hardware and the second hardware becomes smooth.

In the manufacturing method of the connecting metal fitting according to claim 3, the formation of the pilot hole in the first hardware is performed by the auxiliary punch provided at the tip of the first punch and the auxiliary die which is paired with the auxiliary punch. The formation of the prepared hole and the formation of the protruding portion in the first hardware can be continuously performed. For this reason, the manufacturing process can be simplified and the manufacturing time can be shortened.
In the method of manufacturing the connecting metal fitting according to claim 4, since the first and second hardware are used as the fixing members of the first and second pipe fixtures sandwiching the pipe, the first and second fittings are conventionally used. The manufacturing of the pipe fixing tool can be simplified, and the manufacturing cost can be reduced.

(A) is explanatory drawing of the fitting process process of the manufacturing method of the coupling metal fitting which concerns on one embodiment of this invention, (B), (C) is explanatory drawing of a crimping process process. (A)-(C) are explanatory drawings of the press work A in the pre-processing process of the manufacturing method of the connection metal fitting. It is explanatory drawing of the press work B in the pre-processing process of the manufacturing method of the connection metal fitting. It is a perspective view of the clamp metal fitting which uses the connection metal fitting manufactured with the manufacturing method of the connection metal fitting. (A) is a fragmentary sectional view of the clamp metal fitting which concerns on a prior art example, (B) is an expanded sectional view of a connection member.

Next, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention.
As shown in FIGS. 1 to 4, in the method for manufacturing a connecting fitting according to an embodiment of the present invention, the short cylindrical protrusion 11 formed on the first hardware 10 is replaced with the second hardware 12. Is inserted into the circular hole 13 formed in the upper end, the end portion 14 of the projecting portion 11 is pressed to form the enlarged diameter portion 15, and the first hardware 10 and the second hardware 12 are connected to be rotatable. This is a method of manufacturing a metal fitting 16, a pretreatment step in which a protruding portion 11 is formed in a first hardware 10 and a circular hole 13 is formed in a second hardware 12, and a fitting in which the protruding portion 11 is inserted into the circular hole 13 A joint processing step and a caulking processing step of bending the end portion 14 of the protrusion 11 in a state of being fitted into the circular hole 13 outward in the radial direction.
First, after describing the clamp metal fitting 17 using the connection metal fitting 16 manufactured by the method for manufacturing the connection metal fitting according to the embodiment of the present invention, the method for manufacturing the connection metal fitting according to the embodiment of the present invention will be described. .

As shown in FIG. 4, the clamp fitting 17 is made of, for example, steel or stainless steel, and includes first and second pipe fixtures 18 and 19 that form a pair whose surfaces are plated.
The first pipe fixing tool 18 is rotatably connected at one end by a pin 20 and has a fixing member 23 provided with arcuate pipe receiving parts 21 and 22 inside, and an arcuate pipe receiving part 25 inside. , 26 and a screw fastening means 29 capable of fastening the fixed member 23 and the movable member 27 with a pipe (not shown) sandwiched therebetween. On the other hand, the second pipe fixture 19 has the same configuration as that of the first pipe fixture 18, and the screw fastening that can fasten the fixed member 24, the movable member 28, and the fixed member 24 and the movable member 28. A wearing means 29 is provided.

Thus, since the 1st, 2nd pipe fixing tools 18 and 19 have the same structure, below, the number by the side of the 2nd pipe fixing tool 19 is shown in a parenthesis, and description is simplified. .
When viewed from the side, the L-shaped fixing member 23 (24) has a substantially right angle or slightly less than the right angle of the fixing member 23 (24) from one end side to the other end side of the fixing member 23 (24). A pair of pipe receiving portions 21 and 22 that are bent substantially at right angles to the bottom 30 (31) bent at a large angle are provided. In addition, the inside of the pipe receiving portions 21 and 22, that is, the shape of the upper end surface is equal to or larger than the diameter of the pipe (for example, the diameter is 40 mm or more and 50 mm or less) to which the pipe fixture 18 (19) is attached. It has an arc shape with a diameter.

In addition, one end portions of the pipe receiving portions 25 and 26 provided on both sides of the bottom portion 32 of the movable member 27 (28) are inside the one end portions of the pipe receiving portions 21 and 22 provided on the fixed member 23 (24). Is arranged. The inner side of the pipe receiving portions 25 and 26 of the movable member 27 (28), that is, the shape of the upper end surface is equal to or larger than the diameter of the pipe to which the pipe fixture 18 (19) is attached. It has an arc shape.

Through holes 33 and 34 are provided at one end of the pipe receiving portions 21 and 22 of the fixed member 23 (24) and one end of the pipe receiving portions 25 and 26 of the movable member 27 (28), respectively. The holes 33 and 34 are arranged on the same axis, and the pin 20 is inserted into each of the through holes 33 and 34, and the pin 20 is fixed to the fixing member 23 (24).
Thus, when the movable member 27 (28) is opened with respect to the fixed member 23 (24) with the pin 20 as an axis, the outside of the bottom 32 of the movable member 27 (28) is fixed to the fixed member 23 (24). ), The rotation of the movable member 27 (28) relative to the fixed member 23 (24) is controlled.

At the other end of the movable member 27 (28), a groove-shaped locking portion 35 is provided so as to protrude from the bottom 32 of the movable member 27 (28). A U-shaped groove 37 that opens toward the tip of the locking portion 35 is provided in the bottom portion 36 of the locking portion 35, and the locking portion 35 has a bifurcated shape.
A base portion of a screw fastening means 29 is rotatably attached to the other end portions of the pipe receiving portions 21 and 22 of the fixing member 23 (24). The screw fastening means 29 includes a fastening bolt 38 attached to the inside of the other end of the pipe receiving portions 21 and 22, and a fastening nut 39 that is screwed to the fastening bolt 38 and can be attached to and detached from the locking portion 35. ing.
Note that the base of the tightening bolt 38 is routed to each through hole 42 formed in the pipe receiving portions 21 and 22 of the fixing member 23 (24) by using, for example, a headed bolt 40 and a nut 41 screwed to the head bolt 40. Although it is movably attached, for example, it may be rotatively attached using a rivet.

The connecting side of the bottom 30 of the fixing member 23 of the first pipe fixing tool 18 and the bottom 31 of the fixing member 24 of the second pipe fixing tool 19 is substantially flat, and the connecting fitting 16 is formed in this part. ing. That is, the connecting metal fitting 16 is provided in the circular hole 13 provided in the bottom 31 of the fixing member 24 of the second pipe fixture 19 and the bottom 30 of the fixing member 23 of the first pipe fixture 18. It is comprised with the protrusion part 11 inserted in the hole 13 rotatably. Thereby, when using the clamp metal fitting 17, the relative angle of the 1st, 2nd pipe fixing tools 18 and 19 can be arbitrarily adjusted to the target angle.

With the configuration as described above, when using the clamp fitting 17, the pipe receiving portions 21 and 22 of the fixing member 23 (24) are brought into contact with the pipe, and the movable member 27 (28) so as to sandwich the pipe. Then, the tightening bolt 38 is rotated toward the locking portion 35 of the movable member 27 (28). In this way, with the pipe sandwiched between the fixed member 23 (24) and the movable member 27 (28), the tightening bolt 38 is engaged with the U-shaped groove 37 of the forked portion 35 to tighten the tightening bolt 38. The nut 39 is turned using, for example, a spanner or a monkey spanner (a universal spanner), and the fixed member 23 (24) and the movable member 27 (28) are tightened. Note that after tightening the tightening nut 39, the tightening nut 39 is caught on the locking portion 35, so that the tightening nut 39 can be prevented from coming off from the locking portion 35.
Thereby, the 1st, 2nd pipe fixing tools 18 and 19 can be attached in the state pressed on the perimeter of a pipe, respectively, and an assembly scaffold can be assembled.

Subsequently, in order to make the understanding of the invention easier for the manufacturing method of the connection fitting according to the embodiment of the present invention, the fixing member 23 of the first pipe fixture 18 described above is used as the first hardware 10. The fixing member 24 of the second pipe fixture 19 will be described below as the second hardware 12.
First, the first hardware 10 and the second hardware 12 are manufactured using steel or stainless steel. In addition, the 1st, 2nd metal fittings 10 and 12 before manufacture of the connection metal fitting 16 are substantially the same shape, and thickness T1 of the 1st metal fitting 10 and thickness T2 of the 2nd metal fitting 12 are the same. However, either one or both of the shape and thickness may be different.
Next, a pre-processing step is performed which includes pressing A for forming the short cylindrical protrusion 11 on the first metal 10 and pressing B for forming the circular hole 13 on the second metal 12.

In the press processing A, as shown in FIGS. 2A to 2C, first, the lower hole 50 is formed in the first hardware 10, and then inserted into the first die 51 and the first die 51. This is a process for forming the protruding portion 11 on the first hardware 10 using the first punch 52 to be performed.
The first die 51 sets the outer diameter of the protrusion 11 to be formed, and the inner diameter (D1) thereof is, for example, about 25 mm or more and 35 mm or less (here, 28 mm).
On the other hand, the first punch 52 is fitted into the first die 51 to bend the first hardware 10 in which the lower hole 50 is formed to form the protruding portion 11, and the outer diameter thereof is (D1-2). × T1). Here, the thickness T1 of the first hardware 10 is, for example, about 2 mm to 4 mm (here, 2.8 mm to 3.5 mm).

An auxiliary punch 53 is provided at the tip of the first punch 52, and an auxiliary die 54 that is paired with the auxiliary punch 53 is provided on the first die 51.
The auxiliary punch 53 protrudes from the lower end surface of the first punch 52 and is fitted into the auxiliary die 54. On the other hand, the inner diameter (d) of the auxiliary die 54 is set based on the protruding length of the protruding portion 11 to be formed, and the inner diameter is, for example, 10% or more and 40% or less of the inner diameter of the first die 51. (Here, 8 mm). The auxiliary die 54 is a mechanism (for example, a spring material) that moves downward as the first punch 52 is lowered when the protrusion 11 is formed by the first die 51 and the first punch 52. It has.

As a result, as shown in FIG. 2 (A), the first punch 52 is lowered, and as shown in FIG. 2 (B), the first punch 10 is lowered to the first hardware 10 by the auxiliary punch 53 and the auxiliary die 54. Hole 50 is formed. The prepared hole may be formed before the first hardware 10 is transported to the first die 51 and the first punch 52.
Then, as shown in FIG. 2C, the first punch 52 is further lowered to expand the diameter of the lower hole 50 by the first die 51 and the first punch 52, and the diameter-expanded lower hole 55. And the protrusion 11 are formed. At this time, a gap corresponding to the thickness of the first hardware 10 is formed between the inner surface 56 of the first die 51 and the outer surface 57 of the first punch 52, so that the protrusion 11 can be formed smoothly. it can.

The protrusion 11 formed on the first hardware 10 has a bending angle set to 85 degrees or more and less than 90 degrees (preferably 87 degrees or more and less than 90 degrees) with reference to the state before bending (0 degree). ing. Thereby, in the fitting process process mentioned later, insertion of the protrusion part 11 to the circular hole 13 of the 2nd metal fitting 12 can be implemented smoothly.
Since the formed protrusion 11 is for connecting the first hardware 10 and the second hardware 12, the protrusion length L is, for example, twice the thickness T2 of the second hardware 12. It is preferable to be about 10 mm or less (here, 7 mm).

In addition, since the end portion of the protrusion is bent radially outward in the caulking process step, the thickness of the protrusion may be tapered (tapered in cross section) so as to be easily bent. Here, when the thickness of the base end portion of the protruding portion is T1 (thickness of the first hardware 10), the thickness t1 of the tip end portion of the protruding portion is 70% or more and less than 100% (preferably 70% of T1). It is preferably set to 90% or less, more preferably 75% to 85%. Thus, as a method of forming the thickness of the projecting portion in a tapered manner, a gap formed between the inner surface of the first die and the outer surface of the first punch is applied to the tip side of the first punch. What is necessary is just to narrow (for example, the inside diameter of a 1st die | dye toward the pressing direction of a 1st punch).
By the press work A shown above, the protruding portion 11 having the enlarged diameter lower hole 55 is formed in the first hardware 10.

Further, as shown in FIG. 3, the press work B is performed by using a second die 60 and a second punch 61 that fits into the second die 60 in pairs with the second die 60. This is a process of forming the circular hole 13 in the metal piece 12.
The second die 60 sets the inner diameter of the circular hole 13 to be formed, and the inner diameter (D2) is slightly larger than the outer diameter of the protruding portion 11, for example, 0.1 mm to 2 mm (here, 1 mm). ) Is getting bigger.

On the other hand, the second punch 61 having an outer diameter (D2) is inserted into the second die 60 except for the root portion. Actually, the outer diameter of the connection fitting 16 is slightly smaller (for example, about 0.1 mm or more and 0.5 mm or less) than the inner diameter of the second die 60. In addition, an inclined diameter-enlarged portion 62 that expands in the direction opposite to the pressing direction of the second punch 61 is provided at the base portion of the second punch 61.
By the press work B shown above, the minimum inner diameter provided with the inclined enlarged diameter portion 63 in which the insertion direction of the protruding portion 11 of the first metal piece 10 is increased in a taper shape on the second metal piece 12 is (D2 ) Circular hole 13 is formed.
In addition, as shown to FIG. 1 (A), area | region R1 of the thickness direction which forms the inclination enlarged diameter part 63 is 0.2 times or more 0.5 times or less of thickness T2 of the 2nd metal fitting 12, for example, horizontal The region R2 in the direction is 0.2 times or more and 0.6 times or less the thickness T2 of the second hardware 12 from the minimum inner diameter (D2) of the circular hole 13 toward the outside in the radial direction. Moreover, it is preferable that the corner | angular part of an inclination enlarged diameter part is chamfered and makes cross-sectional arc shape.

Then, as shown in FIG. 1 (A), the protruding portion 11 of the first hardware 10 is inserted into the circular hole 13 formed in the second hardware 12 in the pretreatment step, and the inclined diameter increasing portion 63 of the circular hole 13 is provided. A fitting process step is performed so as to be in the direction of the tip of the protruding portion 11. Thereby, the bottom outer surface 64 of the first hardware 10 and the bottom outer surface 65 of the second hardware 12 are brought into contact with each other.
Next, the end portion 14 of the protruding portion 11 inserted into the circular hole 13 is bent radially outward to form the enlarged diameter portion 15, and caulking to connect the first hardware 10 and the second hardware 12 rotatably. Perform processing steps. In this caulking process step, as shown in FIGS. 1B and 1C, a curl die 70 and a curl punch 71 are used.

The curl die 70 is formed such that a front peripheral portion thereof is recessed in an arc shape in cross section, and abuts against a lower inner side 72 of the projecting portion 11 in a state of being fitted into the circular hole 13 of the second hardware 12, and a part thereof. It has a protrusion 73 that fits inside the short cylindrical protrusion 11. In addition, the insertion length of the intrusion portion 73 may be at least as long as the thickness of the first hardware 10.
On the other hand, the curl punch 71 is located on the outer side of the curved crimping portion 74 and the curved crimping portion 74 that bends the end portion 14 of the protruding portion 11 fitted into the circular hole 13, and close to the second hardware 12 at the end of pressing. An annular contact portion 75 is provided.

The curved caulking portion 74 is formed such that the front peripheral portion of the curl punch 71 corresponds to the bent shape of the protruding portion 11 and is recessed in a circular arc shape. Further, the tip 76 of the curl punch 71 is slightly smaller than the inner diameter of the tip of the protrusion 11 (for example, about 0.1 mm or more and 0.5 mm or less), and is opposite to the pressing direction of the curl punch 71. The diameter gradually increases in the direction.
Here, the curvature radius R3 of the curved caulking portion 74 is, for example, 1.2 times to 2.5 times (preferably 1.5 times to 2.5 times) the thickness T1 of the first hardware 10. ing. The curved caulking portion 74 is formed within a range of 130 degrees to 180 degrees (preferably 130 degrees to 170 degrees) from the reference with the angle of the tip 76 of the curl punch 71 as a reference (0 degrees). Perform over the set value.

The lower end position 77 of the annular contact portion 75 protrudes downward from the maximum recess point 78 of the curved caulking portion 74. In addition, it is preferable that this annular contact portion is chamfered to have a circular arc shape in cross section.
The annular abutting portion may be formed with a protruding length that abuts on the second hardware 12 at the end of pressing. In this case, the lower limit position of the curl punch can be set by adjusting the protrusion length of the annular contact portion, so that the contact between the protrusion and the circular hole can be achieved without excessive bending of the end of the protrusion. Resistance can be reduced and even eliminated.

Thereby, the protrusion 11 of the first hardware 10 is bent along the surface of the curved caulking portion 74 while opening outward in the radial direction, and the first hardware 10 and the second hardware 12 are rotatably connected.
Thus, after manufacturing the connection metal fitting 16, when using this for the clamp metal fitting 17 shown in FIG. 4, the 1st, 2nd metal fittings 10 and 12 are used as the fixing members 23 and 24, respectively, The formed through hole 33 is aligned with the through hole 34 of the separately manufactured movable members 27 and 28, and the pin 20 is inserted, and the pin 20 is fixed to the fixing members 23 and 24. Further, the fastening bolts 38 of the screw fastening means 29 are attached to the through holes 42 formed in the other end portions of the fixing members 23 and 24, respectively.
Thereby, the clamp metal fitting 17 can be manufactured.

As described above, the present invention has been described with reference to one embodiment. However, the present invention is not limited to the configuration described in the above embodiment, and is described in the claims. Other embodiments and modifications conceivable within the scope of the above are also included. For example, a case where the manufacturing method of the connecting metal fitting of the present invention is configured by combining some or all of the above-described embodiments and modifications is also included in the scope of the right of the present invention.

10: 1st metal fitting, 11: Protruding part, 12: 2nd metal fitting, 13: Circular hole, 14: End part, 15: Diameter expansion part, 16: Connecting metal fitting, 17: Clamp metal fitting, 18: First Pipe fixing tool, 19: Second pipe fixing tool, 20: Pin, 21, 22: Pipe receiving part, 23, 24: Fixed member, 25, 26: Pipe receiving part, 27, 28: Movable member, 29: Screw Fastening means, 30 to 32: bottom, 33, 34: through hole, 35: locking portion, 36: bottom, 37: U-shaped groove, 38: tightening bolt, 39: tightening nut, 40: headed bolt, 41: nut, 42: through hole, 50: pilot hole, 51: first die, 52: first punch, 53: auxiliary punch, 54: auxiliary die, 55: enlarged diameter lower hole, 56: inner surface, 57 : Outer surface, 60: second die, 61: second punch, 62: inclined enlarged diameter portion, 63: inclined enlarged diameter 64: bottom outer surface, 65: bottom outer surface, 70: curl die, 71: curl punch, 72: lower inner side, 73: protrusion portion, 74: curved crimped portion, 75: annular contact portion, 76: tip portion, 77: Lower end position, 78: Maximum indentation point

The present invention relates to a method of manufacturing a connecting fitting suitable for a clamp fitting that joins the crossing portions of pipe struts that support a scaffold plate, for example, at a construction site.

2. Description of the Related Art Conventionally, an assembly scaffold used at a construction site is configured by connecting pipes arranged vertically and horizontally by a clamp fitting. As shown in FIG. 5A, the clamp fitting 80 has one end of a fixed member 84 and an end of a movable member 85 each provided with an arcuate pipe receiving portion 82, 83 for pinching the pipe 81. The first and second pipe fixtures 88 and 89 form a pair that can be connected to each other and the other end can be detachably fastened by fastening means 87 comprising a screw mechanism. As shown in FIGS. 5A and 5B, each of the first and second pipe fixing tools 88 and 89 includes a connecting member (for example, a connecting member having caulking portions 90 and 91 at both ends, for example, , Pipes or rivets) 92 and connected so as to be relatively rotatable (see, for example, Patent Document 1 and Patent Document 2).

Utility Model Registration No. 2535358 Utility Model Registration No. 3089350

However, since separate connecting members 92 are used for connecting the first and second pipe fixing members 88 and 89, for example, the manufacture of the connecting member 92 and the first and second pipe fixing members 88 and 89 are used. It is necessary to attach the connecting member 92 to the. For this reason, an extra manufacturing process is needed and it becomes complicated, and workability | operativity is bad.
Further, since the connecting member 92 is required separately, the manufacturing cost for manufacturing the connecting member 92 is not economical.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a method of manufacturing a connecting metal fitting that can simplify the manufacturing process, has good workability, and can be manufactured economically.

In the manufacturing method of the connecting metal fitting according to the present invention that meets the above-described object, the short cylindrical protrusion formed on the first hardware is inserted into the circular hole formed on the second hardware, and the protrusion Forming a diameter-enlarged portion by pressing the end portion of the first metal fitting and the second metal fitting manufacturing method,
An inclined enlarged diameter portion is formed on one side of the circular hole, and the enlarged diameter portion of the circular hole is in the direction of the end of the protruding portion. A diameter portion is formed.

The manufacturing method of the connecting metal fitting according to claim 1 or 2 is characterized in that a short cylindrical protrusion is formed in the first hardware, a circular hole is formed in the second hardware, and one side of the second hardware is tapered. Forming a circular hole with an enlarged diameter, and inserting the protruding portion into the circular hole so that the inclined enlarged diameter portion of the circular hole is in the direction of the end of the protruding portion, so when bending the end of the protruding portion radially outward bending not easy.

(A) is explanatory drawing of the fitting process process of the manufacturing method of the coupling metal fitting which concerns on one embodiment of this invention, (B), (C) is explanatory drawing of a crimping process process. (A)-(C) are explanatory drawings of the press work A in the pre-processing process of the manufacturing method of the connection metal fitting. It is explanatory drawing of the press work B in the pre-processing process of the manufacturing method of the connection metal fitting. It is a perspective view of the clamp metal fitting which uses the connection metal fitting manufactured with the manufacturing method of the connection metal fitting. (A) is a fragmentary sectional view of the clamp metal fitting which concerns on a prior art example, (B) is an expanded sectional view of a connection member.

Next, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention.
As shown in FIGS. 1 to 4, in the method for manufacturing a connecting fitting according to an embodiment of the present invention, the short cylindrical protrusion 11 formed on the first hardware 10 is replaced with the second hardware 12. Is inserted into the circular hole 13 formed in the upper end, the end portion 14 of the projecting portion 11 is pressed to form the enlarged diameter portion 15, and the first hardware 10 and the second hardware 12 are connected to be rotatable. This is a method of manufacturing a metal fitting 16, a pretreatment step in which a protruding portion 11 is formed in a first hardware 10 and a circular hole 13 is formed in a second hardware 12, and a fitting in which the protruding portion 11 is inserted into the circular hole 13 A joint processing step and a caulking processing step of bending the end portion 14 of the protrusion 11 in a state of being fitted into the circular hole 13 outward in the radial direction.
First, after describing the clamp metal fitting 17 using the connection metal fitting 16 manufactured by the method for manufacturing the connection metal fitting according to the embodiment of the present invention, the method for manufacturing the connection metal fitting according to the embodiment of the present invention will be described. .

As shown in FIG. 4, the clamp fitting 17 is made of, for example, steel or stainless steel, and includes first and second pipe fixtures 18 and 19 that form a pair whose surfaces are plated.
The first pipe fixing tool 18 is rotatably connected at one end by a pin 20 and has a fixing member 23 provided with arcuate pipe receiving parts 21 and 22 inside, and an arcuate pipe receiving part 25 inside. , 26 and a screw fastening means 29 capable of fastening the fixed member 23 and the movable member 27 with a pipe (not shown) sandwiched therebetween. On the other hand, the second pipe fixture 19 has the same configuration as that of the first pipe fixture 18, and the screw fastening that can fasten the fixed member 24, the movable member 28, and the fixed member 24 and the movable member 28. A wearing means 29 is provided.

Thus, since the 1st, 2nd pipe fixing tools 18 and 19 have the same structure, below, the number by the side of the 2nd pipe fixing tool 19 is shown in a parenthesis, and description is simplified. .
When viewed from the side, the L-shaped fixing member 23 (24) has a substantially right angle or slightly less than the right angle of the fixing member 23 (24) from one end side to the other end side of the fixing member 23 (24). A pair of pipe receiving portions 21 and 22 that are bent substantially at right angles to the bottom 30 (31) bent at a large angle are provided. In addition, the inside of the pipe receiving portions 21 and 22, that is, the shape of the upper end surface is equal to or larger than the diameter of the pipe (for example, the diameter is 40 mm or more and 50 mm or less) to which the pipe fixture 18 (19) is attached. It has an arc shape with a diameter.

In addition, one end portions of the pipe receiving portions 25 and 26 provided on both sides of the bottom portion 32 of the movable member 27 (28) are inside the one end portions of the pipe receiving portions 21 and 22 provided on the fixed member 23 (24). Is arranged. The inner side of the pipe receiving portions 25 and 26 of the movable member 27 (28), that is, the shape of the upper end surface is equal to or larger than the diameter of the pipe to which the pipe fixture 18 (19) is attached. It has an arc shape.

Through holes 33 and 34 are provided at one end of the pipe receiving portions 21 and 22 of the fixed member 23 (24) and one end of the pipe receiving portions 25 and 26 of the movable member 27 (28), respectively. The holes 33 and 34 are arranged on the same axis, and the pin 20 is inserted into each of the through holes 33 and 34, and the pin 20 is fixed to the fixing member 23 (24).
Thus, when the movable member 27 (28) is opened with respect to the fixed member 23 (24) with the pin 20 as an axis, the outside of the bottom 32 of the movable member 27 (28) is fixed to the fixed member 23 (24). ), The rotation of the movable member 27 (28) relative to the fixed member 23 (24) is controlled.

At the other end of the movable member 27 (28), a groove-shaped locking portion 35 is provided so as to protrude from the bottom 32 of the movable member 27 (28). A U-shaped groove 37 that opens toward the tip of the locking portion 35 is provided in the bottom portion 36 of the locking portion 35, and the locking portion 35 has a bifurcated shape.
A base portion of a screw fastening means 29 is rotatably attached to the other end portions of the pipe receiving portions 21 and 22 of the fixing member 23 (24). The screw fastening means 29 includes a fastening bolt 38 attached to the inside of the other end of the pipe receiving portions 21 and 22, and a fastening nut 39 that is screwed to the fastening bolt 38 and can be attached to and detached from the locking portion 35. ing.
Note that the base of the tightening bolt 38 is routed to each through hole 42 formed in the pipe receiving portions 21 and 22 of the fixing member 23 (24) by using, for example, a headed bolt 40 and a nut 41 screwed to the head bolt 40. Although it is movably attached, for example, it may be rotatively attached using a rivet.

The connecting side of the bottom 30 of the fixing member 23 of the first pipe fixing tool 18 and the bottom 31 of the fixing member 24 of the second pipe fixing tool 19 is substantially flat, and the connecting fitting 16 is formed in this part. ing. That is, the connecting metal fitting 16 is provided in the circular hole 13 provided in the bottom 31 of the fixing member 24 of the second pipe fixture 19 and the bottom 30 of the fixing member 23 of the first pipe fixture 18. It is comprised with the protrusion part 11 inserted in the hole 13 rotatably. Thereby, when using the clamp metal fitting 17, the relative angle of the 1st, 2nd pipe fixing tools 18 and 19 can be arbitrarily adjusted to the target angle.

With the configuration as described above, when using the clamp fitting 17, the pipe receiving portions 21 and 22 of the fixing member 23 (24) are brought into contact with the pipe, and the movable member 27 (28) so as to sandwich the pipe. Then, the tightening bolt 38 is rotated toward the locking portion 35 of the movable member 27 (28). In this way, with the pipe sandwiched between the fixed member 23 (24) and the movable member 27 (28), the tightening bolt 38 is engaged with the U-shaped groove 37 of the forked portion 35 to tighten the tightening bolt 38. The nut 39 is turned using, for example, a spanner or a monkey spanner (a universal spanner), and the fixed member 23 (24) and the movable member 27 (28) are tightened. Note that after tightening the tightening nut 39, the tightening nut 39 is caught on the locking portion 35, so that the tightening nut 39 can be prevented from coming off from the locking portion 35.
Thereby, the 1st, 2nd pipe fixing tools 18 and 19 can be attached in the state pressed on the perimeter of a pipe, respectively, and an assembly scaffold can be assembled.

Subsequently, in order to make the understanding of the invention easier for the manufacturing method of the connection fitting according to the embodiment of the present invention, the fixing member 23 of the first pipe fixture 18 described above is used as the first hardware 10. The fixing member 24 of the second pipe fixture 19 will be described below as the second hardware 12.
First, the first hardware 10 and the second hardware 12 are manufactured using steel or stainless steel. In addition, the 1st, 2nd metal fittings 10 and 12 before manufacture of the connection metal fitting 16 are substantially the same shape, and thickness T1 of the 1st metal fitting 10 and thickness T2 of the 2nd metal fitting 12 are the same. However, either one or both of the shape and thickness may be different.
Next, a pre-processing step is performed which includes pressing A for forming the short cylindrical protrusion 11 on the first metal 10 and pressing B for forming the circular hole 13 on the second metal 12.

In the press processing A, as shown in FIGS. 2A to 2C, first, the lower hole 50 is formed in the first hardware 10, and then inserted into the first die 51 and the first die 51. This is a process for forming the protruding portion 11 on the first hardware 10 using the first punch 52 to be performed.
The first die 51 sets the outer diameter of the protrusion 11 to be formed, and the inner diameter (D1) thereof is, for example, about 25 mm or more and 35 mm or less (here, 28 mm).
On the other hand, the first punch 52 is fitted into the first die 51 to bend the first hardware 10 in which the lower hole 50 is formed to form the protruding portion 11, and the outer diameter thereof is (D1-2). × T1). Here, the thickness T1 of the first hardware 10 is, for example, about 2 mm to 4 mm (here, 2.8 mm to 3.5 mm).

An auxiliary punch 53 is provided at the tip of the first punch 52, and an auxiliary die 54 that is paired with the auxiliary punch 53 is provided on the first die 51.
The auxiliary punch 53 protrudes from the lower end surface of the first punch 52 and is fitted into the auxiliary die 54. On the other hand, the inner diameter (d) of the auxiliary die 54 is set based on the protruding length of the protruding portion 11 to be formed, and the inner diameter is, for example, not less than 10% and not more than 40% of the inner diameter of the first die 51. (Here, 8 mm). The auxiliary die 54 is a mechanism (for example, a spring material) that moves downward as the first punch 52 is lowered when the protrusion 11 is formed by the first die 51 and the first punch 52. It has.

As a result, as shown in FIG. 2 (A), the first punch 52 is lowered, and as shown in FIG. 2 (B), the first punch 10 is lowered to the first hardware 10 by the auxiliary punch 53 and the auxiliary die 54. Hole 50 is formed. The prepared hole may be formed before the first hardware 10 is transported to the first die 51 and the first punch 52.
Then, as shown in FIG. 2C, the first punch 52 is further lowered to expand the diameter of the lower hole 50 by the first die 51 and the first punch 52, and the diameter-expanded lower hole 55. And the protrusion 11 are formed. At this time, a gap corresponding to the thickness of the first hardware 10 is formed between the inner surface 56 of the first die 51 and the outer surface 57 of the first punch 52, so that the protrusion 11 can be formed smoothly. it can.

The protrusion 11 formed on the first hardware 10 has a bending angle set to 85 degrees or more and less than 90 degrees (preferably 87 degrees or more and less than 90 degrees) with reference to the state before bending (0 degree). ing. Thereby, in the fitting process process mentioned later, insertion of the protrusion part 11 to the circular hole 13 of the 2nd metal fitting 12 can be implemented smoothly.
Since the formed protrusion 11 is for connecting the first hardware 10 and the second hardware 12, the protrusion length L is, for example, twice the thickness T2 of the second hardware 12. It is preferable to be about 10 mm or less (here, 7 mm).

In addition, since the end portion of the protrusion is bent radially outward in the caulking process step, the thickness of the protrusion may be tapered (tapered in cross section) so as to be easily bent. Here, when the thickness of the base end portion of the protruding portion is T1 (thickness of the first hardware 10), the thickness t1 of the tip end portion of the protruding portion is 70% or more and less than 100% (preferably 70% of T1). It is preferably set to 90% or less, more preferably 75% to 85%. Thus, as a method of forming the thickness of the projecting portion in a tapered manner, a gap formed between the inner surface of the first die and the outer surface of the first punch is applied to the tip side of the first punch. What is necessary is just to narrow (for example, the inside diameter of a 1st die | dye toward the pressing direction of a 1st punch).
By the press work A shown above, the protruding portion 11 having the enlarged diameter lower hole 55 is formed in the first hardware 10.

Further, as shown in FIG. 3, the press work B is performed by using a second die 60 and a second punch 61 that fits into the second die 60 in pairs with the second die 60. This is a process of forming the circular hole 13 in the metal piece 12.
The second die 60 sets the inner diameter of the circular hole 13 to be formed, and the inner diameter (D2) is slightly larger than the outer diameter of the protruding portion 11, for example, 0.1 mm to 2 mm (here, 1 mm). ) Is getting bigger.

On the other hand, the second punch 61 having an outer diameter (D2) is inserted into the second die 60 except for the root portion. Actually, the outer diameter of the second punch 61 is slightly smaller (for example, about 0.1 mm or more and 0.5 mm or less) than the inner diameter of the second die 60. In addition, an inclined diameter-enlarged portion 62 that expands in the direction opposite to the pressing direction of the second punch 61 is provided at the base portion of the second punch 61.
By the press work B shown above, the minimum inner diameter provided with the inclined enlarged diameter portion 63 in which the insertion direction of the protruding portion 11 of the first metal piece 10 is increased in a taper shape on the second metal piece 12 is (D2 ) Circular hole 13 is formed.
In addition, as shown to FIG. 1 (A), area | region R1 of the thickness direction which forms the inclination enlarged diameter part 63 is 0.2 times or more 0.5 times or less of thickness T2 of the 2nd metal fitting 12, for example, horizontal The region R2 in the direction is 0.2 times or more and 0.6 times or less the thickness T2 of the second hardware 12 from the minimum inner diameter (D2) of the circular hole 13 toward the outside in the radial direction. Moreover, it is preferable that the corner | angular part of an inclination enlarged diameter part is chamfered and makes cross-sectional arc shape.

Then, as shown in FIG. 1 (A), the protruding portion 11 of the first hardware 10 is inserted into the circular hole 13 formed in the second hardware 12 in the pretreatment step, and the inclined diameter increasing portion 63 of the circular hole 13 is provided. A fitting process step is performed so as to be in the direction of the tip of the protruding portion 11. Thereby, the bottom outer surface 64 of the first hardware 10 and the bottom outer surface 65 of the second hardware 12 are brought into contact with each other.
Next, the end portion 14 of the protruding portion 11 inserted into the circular hole 13 is bent radially outward to form the enlarged diameter portion 15, and caulking to connect the first hardware 10 and the second hardware 12 rotatably. Perform processing steps. In this caulking process step, as shown in FIGS. 1B and 1C, a curl die 70 and a curl punch 71 are used.

The curl die 70 is formed such that a front peripheral portion thereof is recessed in an arc shape in cross section, and abuts against a lower inner side 72 of the projecting portion 11 in a state of being fitted into the circular hole 13 of the second hardware 12, and a part thereof. It has a protrusion 73 that fits inside the short cylindrical protrusion 11. In addition, the insertion length of the intrusion portion 73 may be at least as long as the thickness of the first hardware 10.
On the other hand, the curl punch 71 is located on the outer side of the curved crimping portion 74 and the curved crimping portion 74 that bends the end portion 14 of the protruding portion 11 fitted into the circular hole 13, and close to the second hardware 12 at the end of pressing. An annular contact portion 75 is provided.

The curved caulking portion 74 is formed such that the front peripheral portion of the curl punch 71 corresponds to the bent shape of the protruding portion 11 and is recessed in a circular arc shape. Further, the tip 76 of the curl punch 71 is slightly smaller than the inner diameter of the tip of the protrusion 11 (for example, about 0.1 mm or more and 0.5 mm or less), and is opposite to the pressing direction of the curl punch 71. The diameter gradually increases in the direction.
Here, the curvature radius R3 of the curved caulking portion 74 is, for example, 1.2 times to 2.5 times (preferably 1.5 times to 2.5 times) the thickness T1 of the first hardware 10. ing. The curved caulking portion 74 is formed within a range of 130 degrees to 180 degrees (preferably 130 degrees to 170 degrees) from the reference with the angle of the tip 76 of the curl punch 71 as a reference (0 degrees). Perform over the set value.

The lower end position 77 of the annular contact portion 75 protrudes downward from the maximum recess point 78 of the curved caulking portion 74. In addition, it is preferable that this annular contact portion is chamfered to have a circular arc shape in cross section.
The annular abutting portion may be formed with a protruding length that abuts on the second hardware 12 at the end of pressing. In this case, the lower limit position of the curl punch can be set by adjusting the protrusion length of the annular contact portion, so that the contact between the protrusion and the circular hole can be achieved without excessive bending of the end of the protrusion. Resistance can be reduced and even eliminated.

Thereby, the protrusion 11 of the first hardware 10 is bent along the surface of the curved caulking portion 74 while opening outward in the radial direction, and the first hardware 10 and the second hardware 12 are rotatably connected. Thus, after manufacturing the connection metal fitting 16, when using this for the clamp metal fitting 17 shown in FIG. 4, the 1st, 2nd metal fittings 10 and 12 are used as the fixing members 23 and 24, respectively, The formed through hole 33 is aligned with the through hole 34 of the separately manufactured movable members 27 and 28, and the pin 20 is inserted, and the pin 20 is fixed to the fixing members 23 and 24. Further, the fastening bolts 38 of the screw fastening means 29 are attached to the through holes 42 formed in the other end portions of the fixing members 23 and 24, respectively.
Thereby, the clamp metal fitting 17 can be manufactured.

As described above, the present invention has been described with reference to one embodiment. However, the present invention is not limited to the configuration described in the above embodiment, and is described in the claims. Other embodiments and modifications conceivable within the scope of the above are also included. For example, a case where the manufacturing method of the connecting metal fitting of the present invention is configured by combining some or all of the above-described embodiments and modifications is also included in the scope of the right of the present invention.

10: 1st metal fitting, 11: Protruding part, 12: 2nd metal fitting, 13: Circular hole, 14: End part, 15: Diameter expansion part, 16: Connecting metal fitting, 17: Clamp metal fitting, 18: First Pipe fixing tool, 19: Second pipe fixing tool, 20: Pin, 21, 22: Pipe receiving part, 23, 24: Fixed member, 25, 26: Pipe receiving part, 27, 28: Movable member, 29: Screw Fastening means, 30 to 32: bottom, 33, 34: through hole, 35: locking portion, 36: bottom, 37: U-shaped groove, 38: tightening bolt, 39: tightening nut, 40: headed bolt, 41: nut, 42: through hole, 50: pilot hole, 51: first die, 52: first punch, 53: auxiliary punch, 54: auxiliary die, 55: enlarged diameter lower hole, 56: inner surface, 57 : Outer surface, 60: second die, 61: second punch, 62: inclined enlarged diameter portion, 63: inclined enlarged diameter 64: bottom outer surface, 65: bottom outer surface, 70: curl die, 71: curl punch, 72: lower inner side, 73: protrusion portion, 74: curved crimped portion, 75: annular contact portion, 76: tip portion, 77: Lower end position, 78: Maximum indentation point

Claims (2)

The short cylindrical protrusion formed on the first hardware is inserted into the circular hole formed on the second hardware, and the end of the protrusion is pressed to form the enlarged diameter part, A manufacturing method of a connecting metal fitting for connecting the first hardware and the second hardware,
An inclined enlarged diameter portion is formed on one side of the circular hole, and the enlarged diameter portion of the circular hole is in the direction of the end of the protruding portion. A manufacturing method of a connecting metal fitting characterized by forming a diameter part. 2. The method of manufacturing a connecting metal fitting according to claim 1, wherein a region in the thickness direction in which the inclined enlarged diameter portion is formed is in a range of 0.2 to 0.5 times the thickness of the second hardware. The horizontal region in which the inclined enlarged diameter portion is formed is 0.2 times or more and 0.6 times or less the thickness of the second hardware from the smallest inner diameter of the circular hole toward the outer side in the radial direction. The manufacturing method of the coupling metal fitting characterized by being in the range.

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