JPS649092B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for forming an end of a square pipe when welding a pipe material or a shaft member to the end.

A square pipe molded product is used for a rear fork of a motorcycle, and as is known in the art, a pipe material or a shaft-shaped pivot member is welded between the front ends of left and right pipe members so as to be perpendicular to the axial direction of the members.

When a pipe material or a shaft member is welded to such an end, the end is conventionally formed as shown in FIGS. 11 to 15, for example.

That is, as shown in FIG. 12, a V-shaped notch 63 is provided on both side surfaces 62, 62 of the end portion 61 of the square pipe 60 as shown in FIG. The end portion 61 is pressed and crushed from above and below so as to close the end portion 63, the end portion is formed into a tapered shape as shown in FIG. 18, and the closed slit portion 64 is welded and joined.
As shown in FIG. 4, a recess 66 is formed in the edge 65 in a semicircular shape corresponding to the diameter of the pipe material or shaft member to be joined to the end edge 65 by cutting or forging.

The above conventional molding technology includes a V-shaped notch molding process,
It requires processes such as welding the overlapped slit parts, which requires a lot of man-hours and has poor workability and productivity.
It is disadvantageous in terms of cost, and since a notch is provided on the side of the square pipe, it is difficult to say that it is the best in terms of strength and rigidity.Furthermore, as shown in FIG. , improvement is desirable in order to obtain a sufficient welding area.

The present invention has been made to improve the above problems.

SUMMARY OF THE INVENTION An object of the present invention is to provide an apparatus for forming an end of a square pipe, which can form the end of a square pipe at low cost without losing rigidity.

In order to achieve the above object, the present invention applies pressure so as to fit the shape of the tapered core in which the end of the square pipe is formed, and forms the end of the square pipe into a tapered shape with the top and bottom crushed. The device was constructed so that the side surface of the end portion was formed so as to bulge outward.

Next, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 to 5 are explanatory diagrams showing a molding method using the apparatus of the present invention.

FIG. 1 is a perspective view of a square pipe 1. The pipe 1 has, for example, a horizontally long rectangular cross section, consists of upper and lower pieces 2, 3, and left and right side pieces 4, 5, is long in the axial direction, and is cut to a predetermined length. and get pipe 1. Pressure is applied from above and below to the upper and lower pieces 2 and 3 of the end portion 6 so that they become tapered, and slopes 7 and 8 are formed so as to approach the end portions. The upper and lower ends of the end portion 6 are formed into such a tapered shape as slopes 7, 8, and in this forming process, the excess thickness at the end portions of the side pieces 4, 5 is made to bulge laterally symmetrically, and this is shown in FIG.
A semicircular recess 12 corresponding to the diameter of the shaft is formed by notching or forging, and FIG. 5 shows a perspective view.

Next, to explain the above molding in detail in relation to the apparatus, the molding apparatus 20 is as shown in FIG.
A base 23 having a flat contact surface 22 is fixedly set up on a portion near one end in the length direction of the base 21, a rotating shaft 24 is installed vertically within the base 23, and the upper end of the rotating shaft 24 is placed on the base 23. A handle 25 is provided on this protrudingly. A core 26 is arranged on the base 21 so as to be parallel to the base 21 and spaced apart from the upper surface thereof by a predetermined height. The abutment surface 22 is provided with a gap in the width direction necessary to allow the base 26a of the core 26 to swing left and right at a predetermined angle within a horizontal plane. The base 26a of the core 26 is the pipe 1
The intermediate portion 26b is formed to have a small diameter so as to fit loosely with the pipe 1, and the tip portion 26c has a base portion 26d that is in close contact with the inner circumference of the pipe, and the left and right sides extend to the tip. Side pieces 4, 5 of pipe 1
The upper and lower surfaces 26e and 26f are set so as to be in close contact with each other and to form a tapered surface such that the upper and lower surfaces 26e and 26f approach each other toward the distal end.

For the above core 26, rotate the handle 25 to either the left or right so that the tip 26c faces the outside of the base 21, fit the pipe 1 from the tip 26c, and fit into the entire core 26. . Return the handle 25,
Set the core so that it matches the axis of the base 21,
The pipe 1 is further pushed in so that its rear end 13 comes into contact with the contact surface 22 of the base 23. This is shown in FIG. 6, and the length from the contact surface 22 to the tip 26g of the core 26 is equal to the length of the pipe 1, which is the workpiece.

A mold 28 is disposed on the base 21 near the other end, and is slidable in the length direction of the base 21, that is, in the length direction of the core and the pipe 1. It is provided on a slide base 28a that engages with a guide groove 27 provided in the front-rear direction. Molding mold 28
is opened in the direction of the core 26, and the axial direction is opened in the direction of the core 26.
A tapered female tapered molding part 29 is provided, and the molding part 29 has a tip end 26c of the core 26.
The upper and lower female tapered slopes 26e and 26f and the upper and lower slopes 29a and 29b are set so that the male and female fit together with a gap equivalent to the wall thickness of the pipe 1, and in the embodiment, the molded part 29 is opened forward in the axial direction. ing.

The rear surface of the mold 28 is a cam surface 30 consisting of an inclined surface, and a lift cam 32 having a cam surface 31 opposite thereto is provided. As shown in Fig. 6, the cam 32 is located in front of the core and the tip of the pipe and is separated from them.
The state in which the mold 28 is separated from the mold 28 is defined as the pre-molding and dispensing state, and the mold 28 is biased in the direction of separation by an elastic member 34 such as a spring, and is in the position shown in FIG. 6 by a stopper or the like. That is, a cam surface 30 on the rear surface, a cam surface 31 that comes into sliding contact with this, and this cam surface 3.
The mold 2 is moved up and down by the action of a mold advancing/retracting mechanism 35 consisting of a lifting platform 33 and a pressing member 34 for raising and lowering the mold 2.
8 advances and retreats.

By the way, as is clear from FIG. 8, in the width direction of the molded part 29, both sides 29c and 29d of the inlet part are sufficiently larger than the width of the pipe 1, and are wider than the width between these parts after the left and right bulge molding described above. Set it slightly larger. Both inner walls 29e and 29f are tapered so as to gradually become wider toward the back.

In the above process, the lifting platform 33 is moved downward, which causes the cam 32 to descend, and its cam surface 31 engages with the cam surface 30 of the mold 28, and as the downward movement continues, the action of the cam surfaces 31 and 30 causes the cam 32 to descend. Molding mold 2 at the rear in the axial direction
8 slides while being guided by the groove 27, and moves in the direction of the core and pipe on the fixed side in the axial direction. The molded part 29 fits into the tip of the pipe 1, and since the upper and lower slopes 29a and 29b of the molded part 29 are as described above, the pipe 1
The distal end portion of the core is bent vertically from the leading edge while sliding relative to each other, and is formed into a tapered shape between it and the core distal end portion 26c.

This is shown in Fig. 7, where the tip of the pipe 1 is pressurized in the vertical direction and becomes tapered.
On the other hand, the inside of the side piece of the pipe material to be processed is connected to the core 26.
is restricted by both sides of the tip 26c, and cannot deform inwardly.On the other hand, since there is clearance on both inner sides of the molded part 29 as described above, both sides expand outward in a semicircular shape. It will be released.

After molding, the lifting table 33 is raised to release the engagement between the cam 32 and the mold 28, whereby the mold is released, moves to the left in the figure, and returns to the position before molding in FIG. 6. Next, the shaft 24 is rotated via the handle 25, whereby the square pipe base end 13 moves laterally while following and abutting the contact surface 22, and moves in the direction of removal from the core. . This is shown as an imaginary line in Figure 8.

In this way, the tip can be formed into a shape that is tapered and bulges laterally. After the above process, the recess 12 is formed by forging or the like.

To explain a rear fork as an example using the square pipes formed above, square pipes A and B formed as described above are bent symmetrically from the middle part, and end pieces C and C are welded to the rear ends. With,
A cross plate D is horizontally joined between the intermediate front parts, and a pipe material E, for example, is inserted between the tip parts formed according to the above description.
and weld half the circumference of the pipe material E to the recess F to obtain a rear fork as shown in FIGS. 9 and 10.

Although the above embodiments have shown the formation of a square pipe for forming a rear fork, the invention can be carried out in any manner.

16 to 23 show modified embodiments of the present invention, and the same parts as above are given the same reference numerals, and only the changed parts will be described.

In this embodiment, the upper and lower pieces 102 and 103 of the end 106 of the square pipe 101 are pressurized from above and below to form a tapered shape as shown in FIG.
6 are formed as slopes 107 and 108, and in this forming process, one of the side pieces 104 and 105, for example, side piece 105, is formed into a 17th slope.
16 shows an end view of the end 106 of the pipe 101. As shown in FIG.

Next, the above-mentioned forming will be explained in relation to the apparatus 120.
h, 126i (see Figure 21), pipe 1
A recess 140 having a length in the axial direction and being released at the tip 126g of the core 126 is provided on the side surface 126h on the side where 01 is to be expanded.

On the other hand, a molding section 129 provided in the mold 128
The upper and lower slopes 129a and 129b are tapered as described above, and the inner wall 129
e and 129f are formed parallel to the axial direction (see FIG. 20). The width of the molded part 129 is made sufficiently larger than the width of the pipe 101, and
01, a clearance is formed between the inner wall 129e on the side of the recess 140 and the side piece 105 of the pipe 101 on the same side, and the inner wall 129f on the opposite side and the side piece 104 are set so that they are in close contact with each other.

The inner wall 1 of the molded part 129 on the recess 140 side
An inner mold 141 for expanding the side piece 105 of the pipe 101 is provided near 29e. The inner mold 141 has a prismatic shape with the same height as the tip 126g of the core 126, has a pointed tip, and has an inner wall 129 of the molding part 129.
The side surface 142 on the e side is formed in a tapered shape, and the side surface 143 on the inner wall 129b side has both inner walls 129e,
Recess 1 formed in core 126 parallel to 129f
A convex portion 144 is provided in the axial direction so as to engage with the convex portion 40 .

In the above, when the mold 128 moves in the direction of the core and the pipe as described above, the tip of the pipe 101 slides relative to the top and bottom slopes 129a, 129b of the molding part 129 and the top and bottom of the core tip 126c. It is bent in the vertical direction from the leading edge between the slopes 126e and 126f, and is formed into a tapered shape.
This is shown in FIG. At this time, the molding section 129
The inner mold 141 placed in the inner mold 141 moves in the direction of the core and the pipe together with the mold 128, and the convex portion 1 provided on the side surface 143 of the inner mold 141 moves as shown in FIGS.
44 is a recess 14 formed in the core tip 126c.
0, and the recess 14 of the processed part of the pipe material
The side piece 104 on the opposite side to the core tip 1 has an inner side
26c, the outside is restricted by the inner wall 129f of the molding part 129, and deformation is impossible, but the side piece 105 on the concave part 140 side is laterally moved along the tapered side wall 142 of the inner mold 141. Expanded. Figure 20 shows the state after molding.

In this way, the square pipe can be formed into a shape that is tapered and only one of the side pieces expands laterally.

As described above, according to the present invention, there is provided a mold having a core having a tapered surface, female tapered upper and lower slopes, and a molding portion with an inner wall bulging outward, and a core having a tapered surface. The end of a square pipe can be easily formed with good quality using a simple molding device consisting of a mold advancing and retracting mechanism that moves the mold forward and backward.

Furthermore, by turning the tip of the core away from the mold by operating the handle, the square pipe can be attached and removed without significantly retracting the mold, simplifying the equipment and improving work efficiency.

[Brief explanation of drawings]

Figures 1 to 5 are explanatory diagrams showing the molding process,
Figure 1 is a perspective view of the square pipe, Figure 2 is a side view of the molded state, Figure 3 is a side view of the recessed part,
Figure 4 is an end view of the same, Figure 5 is a perspective view of the same, Figure 6 is a side view of the molding device before molding, Figure 7 is a view during molding, and Figure 8 is a plan view after molding. Figure 9 is a plan view of the rear fork, Figure 10 is a side view of the same, and Figure 1 is a top view of the rear fork.
1 to 15 are diagrams explaining the conventional forming process, FIGS. 16 to 23 are explanatory diagrams showing a modified example, FIG. 16 is an end view of the square pipe in the formed state, and FIG. 17 is a diagram showing a modified example. The same plan view, FIG. 18 is the same side view,
Figure 19 is a side view of the molding equipment during molding, Figure 20 is a plan view after the same molding, Figure 21 is an enlarged plan view of the main parts of the molding equipment before molding, and Figure 22 is the same during molding. 23 is a view taken along the line AA in FIG. 22. In addition, in the drawing, 1 is a square pipe, 20 is a forming device,
21 is a base, 24 is a rotating shaft, 25 is a handle, 2
6 cores, 26e and 26f are the upper and lower surfaces of the tip of the core, 28 is the mold, 29 is the same molding part, 29a, 2
9b is the same upper and lower slopes, 29e and 29f are the same inner walls,
30 is a cam surface on the rear surface of the mold, 31 is a cam surface on the lifting table side, 33 is a lifting table, 34 is an elastic member, and 35 is a mold advancing/retracting mechanism.

Claims (1)

[Claims] 1. A square pipe is penetrated and supported by the base and the base of the tip, the base has a rotation handle at the upper end and is fixed to a rotating shaft standing from the base, and the top and bottom surfaces of the tip are A core has a tapered surface and the side surface of the tip portion is in close contact with the inner periphery of the square pipe before molding, and a molding part that opens toward the core is bored, and the core is formed above and below this molding part. a mold having a female tapered slope corresponding to the tapered surface of the mold, and at least one of the inner walls of the molding part being bulged outward from the outer surface of the pipe after bulging molding; and a rear surface of the mold. It consists of a sloping cam surface formed on the cam surface, a lifting platform equipped with a cam surface that slides in contact with the cam surface and descends to move the mold forward, and an elastic member that biases the mold in the backward direction. A device for forming an end of a square pipe, comprising a mold advance/retreat mechanism for advancing and retracting a mold toward the core.