JP2659129B2 - Pipe dowel forming equipment - Google Patents

Description

The present invention relates to an apparatus for forming a dowel on a peripheral wall of a pipe, and more particularly, to a method for engaging a notch of a joint with a steel pipe used for forming a temporary scaffold. The present invention relates to a dowel forming device provided.

[Conventional technology]

The basic structure of a conventional connecting device used for connecting upper and lower pipes constituting a temporary scaffold will be described with reference to FIG. A stepped portion 2 is provided around the joint 1, and an engaging notch 3 which is bent radially in the middle from the end of the joint 1 in the axial direction from the end of the joint 1 is provided at an opposite position sandwiching the axis at both ends of the joint 1. A pair of dowels 5, 5 project from the inner surface of the connecting pipe 4 to be inserted into the outside at opposite positions sandwiching the axis.

To connect the joint 1 and the connection pipe 4, the connection pipe 4 is externally inserted into the joint 1 and the dowel 5 is engaged with the notch 3.
Into the vertical part 3a of the connection pipe 4 or the joint 1
Is pivoted to fit the dowel 5 into the horizontal portion 3b of the engagement notch 3, so that the tensile load of the connecting pipe 4 and the joint 1 is supported by the engagement of the dowel 5 with the side edge 3c of the horizontal portion 3b. Has become.

By the way, in the connection device as described above, in the connected state, the compressive load is supported by the contact between the end face of the connection pipe 4 and the support step portion 2, so that a sufficient supporting force can be obtained.

On the other hand, since the tensile load is supported by the dowel 5 and the side edge 3c of the horizontal portion 3b, the hooking dowel 5 is particularly required to have a shape and a structure excellent in tensile strength.

For this reason, in the tensile load test of the connection device, the amount of movement of the joint 1 and the connection pipe 4 in the axial direction is measured in a state where a predetermined tensile load is applied. As a rejected product.

In the connecting device as described above, in order to form a dowel with high precision in shape in the connecting pipe, when extruding the dowel with a male mold from the outer surface side, the inner surface side is supported by a female mold, and the female mold is formed. The shape of the dowel needs to be formed to be constant by the recess, and the female mold must adopt a structure that can be removed from the inside of the pipe regardless of the dowel protruding inward.

The female mold in the conventional dowel forming apparatus has a split mold structure that can be divided into a plurality of molds in order to allow extraction from inside the pipe.

[Problems to be solved by the invention]

However, the structure in which the female mold is divided into a plurality of parts and assembled has a problem in that since the mechanism is complicated, high processing accuracy is required for the production and the production cost is high.

It is an object of the present invention to provide a pipe dowel forming apparatus capable of forming a highly accurate dowel with a simple structure in order to solve the above problems.

[Means for solving the problem]

In order to solve the above-described problems, the present invention provides a female mold provided with a dowel-shaped recess on the outer peripheral surface, and pressing a position corresponding to the dowel-shaped recess with a peripheral wall of a pipe externally inserted into the female mold. And a male mold that forms a dowel, wherein the female mold is
At the tip of the core having a dowel-shaped recess formed on the outer periphery of the leading end, a rotary core forming the peripheral edge of the dowel-shaped recess is attached, and the dowel is removed in the axial direction from the inside of the dowel-shaped recess at the outer periphery of the rotary core. Is formed by providing a notch therefor.

[Action]

With the pipe fitted externally to the female mold, approach the male mold to the pipe, press the position corresponding to the dowel-shaped recess on the peripheral wall of the pipe with the male mold, and use the male mold and the dowel-shaped recess to seal the pipe peripheral wall. Deform to form dowels.

After the male mold retreats, rotate the female rotating mandrel so that the notch provided on the outer peripheral surface is located at the tip of the dowel forming recess, so that when the pipe is pulled out from the female mold, the dowel is cut from the forming recess. Can be pulled out through the notch.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

As shown in FIGS. 1 to 5, a female mold 13 is fixed in a horizontal state on a base table 11 and attached to a cylindrical mold body 12 having an inner diameter into which the pipe 4 is fitted. Female type 13
A pair of left and right male dies 14, 14 are arranged on both sides sandwiching.

The female mold 13 has a cylindrical core 15 having an outer diameter with which the inner diameter of the pipe 4 is fitted, and a rotating shaft 16 inserted into the core 15.
And a rotating core 17 attached to the rotating shaft 16 on the tip side of the core 15 and a drive mechanism 18 for rotating the rotating shaft 16.

The core metal 15 is fixed so that a flange 19 provided on the outer peripheral surface of the rear end portion is sandwiched between the mold body 12 and the sub-block 20 so as to be coaxially arranged inside the mold body 12.

As shown in FIG. 5, the dowel-shaped concave portions 21 provided on both sides of the outer periphery of the leading end of the cored bar 15 are formed in a substantially horseshoe shape that opens at the leading edge of the cored bar 15.

The rotating mandrel 17 arranged at the tip of the mandrel 15 is
Notches 22, 22 are formed along the axial direction to remove the dowels 5 on both outer peripheral surfaces sandwiching the axis.

The rotary core 17 has notches 22 and 22 with dowel-shaped recesses 21 and
5, the rear edge 22a of the rotating core 17 closes the rear end of the dowel forming recess 21, and the rear edge 22a forms the front end of the dowel 5, as shown in FIG. Part to do.

Also, when the rotary core 17 is rotated so that the notch 22 is located at the tip of the dowel forming recess 21, the dowel 5 formed in the dowel forming recess 21 can be removed in the axial direction by the notch 22. To

Therefore, the notch 22 is formed to be equal to or wider than the width of the dowel-shaped recess 21.

The drive mechanism 18 of the rotary shaft 16 is formed by using a cylinder 23, and connects a tip of a rod 24 and an arm 25 fixed to a rear end of the rotary shaft 16 by a link 26 as shown in FIG. The rotary mandrel 17 is rotated via the rotary member 16 between a state in which the notch 22 is located on the tip side of the dowel-shaped concave portion 21 and a state in which the notch 22 is apart therefrom.

As shown in FIGS. 1 and 5, the notch 22 of the rotating core 17 is separated from the dowel forming recess 21 so that the rear edge 22a can completely fix the state in which the tip of the dowel forming recess 21 is closed. , A horizontal hole 27 is provided in the middle of the rotating shaft 16 and the sub-block 20 is provided.
A set pin 29 is attached to the cylinder 28 so as to engage and disengage from the horizontal hole 27 so that the rotary shaft 16 can be fixed by the horizontal hole 27 and the set pin 29.

The pushing mechanism 30 arranged on the rear piece of the female die 13 is configured to advance and retreat two push rods 31 in the axial direction by the cylinder 32, and the outer peripheral surface of the core metal 15 from the hole 33 of the flange 19 at the time of forward movement. Push rod 31
Moves in the axial direction, and presses the end of the pipe 4 fitted to the cored bar 15 to push it out in the axial direction.

The mold body 12 detects the tip of the pipe 4 inserted into the cored bar 15 and displays the positioning state where the tip of the pipe 4 abuts against the flange 19, as shown in FIG. Tsuba 19 on body 12
A pipe 4 inserted in the cored bar 15 is provided with a vertical hole 34 at a position close to the pipe 4 and a detecting member 35 having an inclined surface at its tip is urged by a spring 36 so as to constantly move inward by a spring 36. When the tip of the member abuts against the flange 19, the detecting member 35 is pushed outward by the pipe 4, so that the movement of the detecting member 35 can be confirmed by the cap 37.

In the case of the first example shown in FIGS. 1 to 5, a pair of male dies 14 and 14 arranged at positions on both sides of the female With dowel molding recess 2
A cylinder in which a lateral hole 41 is provided at a position facing 1, 21 and the male mold 14 housed in the lateral hole 41 is fixed to both outer surfaces of the mold body 12.
It is designed to move forward and backward at 42.

The male dies 14 and 14 are formed in a substantially horseshoe shape which is smaller than the dowel-shaped recess 21 by the thickness of the pipe 4. The dowel 5 is formed using plastic deformation.

FIG. 6 shows a second example of the male mold 14, wherein the first
In this embodiment, the same structure as that of the above example is adopted, and the moving direction is arranged so as to be inclined with respect to the axis of the female mold 13. This angle of inclination may be set freely according to the thickness of the pipe 4 and the shape of the dowel 5.

A third example of the male mold 14 shown in FIG. 7 is that a swing arm 51 is swingable about a shaft 53 in conjunction with a jack 52, and a dowel-shaped recess 21 is formed at the tip end of the swing arm 51. A male mold 14 is provided to protrude toward.

The dowel forming apparatus of the present invention is configured as described above,
Next, a method of dowel molding will be described.

As shown in FIG. 5, the rotary core 17 is set so that the notch 22 is located at a position away from the dowel forming recess 21 and the pipe 4 is rotated.
Into the female mold 13.

At this time, the outer diameter of the pipe 4 is supported by the mold body 12, and the portion protruding from the mold body 12 is received by the V-shaped block 54.

When the pipe 4 is inserted to a position where the tip of the pipe 4 comes into contact with the flange 19, the detection member 35 moves outward and the positioning is confirmed.

After the positioning, the male dies 14 and 14 approach and move toward the female dies 13, and the male die 1 is positioned at the position facing the dowel forming recesses 21 and 21 on the peripheral wall of the pipe 4.
4 and 14 press, and as shown in FIGS.
Dowels 5, 5 protruding toward the inner surface side are formed.

When the male dies 14, 14 return to the retracted position after the formation of the dowels 5, 5, the set pin 29 is pulled out of the lateral hole 27, and the rotating core 17 is rotated by the operation of the drive mechanism 18, and the notch 22 is in the notch 22. The push rod 31 of the pushing mechanism 30 moves forward in this state, and pushes out the pipe 4 in the pushing direction to remove it from the female mold 13.

At this time, the dowel 5 in the dowel forming recess 21 is pulled out through the notch 22, and the formation of the dowels 5, 5 is completed by removing the pipe 4 from the female mold 13.

As described above, the dowels 5, 5 formed in the pipe 4 are:
It is formed by pushing a part of the peripheral wall of the pipe 4 in a seamless state and protruding toward the inner surface side. Next, a preferable shape and structure of the dowel 5 will be described.

The dowel 5 is extruded in a substantially horseshoe shape as viewed from the front as shown in FIG. 8, and as shown in FIGS. 8 and 9, the portion of the engaging notch 3 engaging with the side edge 3c of the flat portion 3b becomes the flat portion 5a. The portion that transitions from the flat portion 5a to the inner periphery of the connection pipe 4 is the centering portion 5b of the joint 1 and the connection pipe 4.

The centered portion 5b is formed by a curved surface in the case shown in the figure, and the radius R is set to approximately 1/2 of the difference between the inner diameter D of the connection pipe 4 and the outer diameter d of the joint 1. This centripetal part 5b
It may be formed by a linear inclined surface.

Further, the width F of the flat portion 5a is set to be equal to or larger than the thickness T of the joint 1;
FIG. 5a is a horizontal plane in the form of a moon as shown in FIG. In the state where the joint 1 and the connection pipe 4 are connected, as shown in FIG. 9, the dowel 5 is fitted in the horizontal portion 3b of the engagement notch 3, and at this time, when a tensile force acts on the connection pipe 4, ,
The dowel 5 comes into contact with the side edge 3c of the horizontal portion 3b, and the connection pipe 4 and the joint 1 become coaxial with the action of the centripetal portion 5b, and the flat portion 5a of the dowel 5 comes into contact with the side edge 3c and is connected. The vertical load of the pipe 4 is transmitted to the joint 1 as a vertical load.

Accordingly, the dowel 5 and the joint 1 are engaged with each other in a planar manner, and there is no escape of the dowel 5 to the outside, and the tensile load can be supported without causing the connecting pipe 4 to move in the axial direction.

The dowel 5 having such a shape and structure may be manufactured so that the shapes of the dowel forming recess 21 and the male mold 14 are coupled to the dowel 5 described above.

〔The invention's effect〕

As described above, according to the present invention, the dowels can be formed on the pipe without using the female mold having the split structure, and the structure of the female mold can be simplified, so that the equipment cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a plan view of a cutaway portion of the dowel forming apparatus according to the present invention, FIG. 2 is a front view of the cutout portion of the cutaway portion, FIG. 3 and FIG. Is an exploded perspective view of a dowel-molded portion, FIG. 6 is a cross-sectional plan view showing a second example of a dowel-molded male mold, FIG. 7 is a cross-sectional plan view showing a third example of a dowel-molded male mold, and FIG. The figure is an exploded perspective view of a pipe connecting device using a dowel, and FIG. 9 is an enlarged vertical sectional view showing a use state of the formed dowel. 4 ... pipe, 5 ... dowel, 12 ... mold body, 13 ... female, 14 ... male, 15 ... core, 16 ... rotating shaft, 17 ... rotating core, 21 ... … Dowel recess, 22… Notch.

Claims (1)

(57) [Claims] 1. A female mold having a dowel-shaped recess formed on an outer peripheral surface thereof, and a male mold forming a dowel by pressing a position corresponding to the dowel-formed recess by a peripheral wall of a pipe externally fitted into the female mold. The female mold is configured such that a rotating core bar forming a tip peripheral edge of the dowel forming recess is attached to a tip of a core bar having a dowel forming recess at the tip end outer periphery. Dowel forming apparatus for forming a pipe formed with a notch for extracting a dowel axially from a pipe.