JPS5838262B2 - Method for processing a metal tube with a small diameter to wall thickness ratio into a tapered shape using a swaging machine, and a fitting device - Google Patents

Description

[Detailed Description of the Invention] The purpose of this invention is to prevent buckling of the pipe wall when processing a metal pipe with a small diameter to wall thickness ratio into a tapered shape using a swaging machine. The present invention relates to a method and a metal fitting device for processing a metal tube with a small diameter to wall thickness ratio into a tapered shape using a swaging machine.

Conventionally, the following method is known for processing a metal tube into a taber shape using a swaging machine.

The first method is to perform swaging using a taper die without using a mandrel, but in this case, the following taper fan angle and pipe diameter to wall thickness ratio (
(many).

Machining fan angle Pipe diameter to wall thickness ratio Amount of taper 1 degree to 2 degrees 1.5 factor Approximately 1760 to 1/302 degrees to 4 degrees
2nd section Approximately 1730 to 1/154 degrees to 6 degrees 3
The second method is to taper a metal tube with a small diameter to wall thickness ratio (excellent).

In this method, a mandrel is used. As shown in Fig. 2, one tapered end 1a of the mandrel 1 is inserted into the processing section of the metal tube 2 in advance, and then inserted into the center of the die 3 for swaging. It is something to do.

According to the second method, there is an effect of making the inner surface of the metal tube glittery.

However, even if the ratio of pipe diameter to wall thickness is small, it can be processed effectively if the fan angle is small and the length of the taper to be processed is short.

However, when machining with a mandrel inserted in this way, the degree of freedom of deformation of the metal tube is reduced, and this requires a significant increase in the pressurizing force at the machining section, which often destroys the mandrel. , or there was a risk of damaging the dice.

In a third method, as shown in FIG. 3, the position of the mandrel 1 is fixed by a chuck 4, and the metal tube 2 is inserted between the die 3 and the mandrel.

According to the third method, the amount of taper is /60~re3
In the case of 0, there is an effect that the pipe diameter to wall thickness ratio (coupling) can be kept up to 1coupling.

However, the third method has problems such as not only poor workability during processing but also the risk of damaging the mandrel for a while.

For example, this may occur when the pressure applied to the mandrel suddenly increases due to a change in the position of the metal core provided inside the mold, an increase in the weld bead, or a change in the inner thickness of the pipe.

However, in this invention, a metal fitting parallel to the pressurizing surface of the die is inserted into the inside of the metal tube to be processed in a loose state, and the metal tube is clamped by the static inertia of the die and the metal tube. Since the metal pipe is processed using
Even when there were changes in the amount and length of the taper, as well as changes in the size of the beat of the metal tube, we succeeded in processing the taper with good workability and high efficiency.

That is, this invention will be explained with reference to the implementation apparatus shown in FIGS. 1, 4, and 5.

The device for implementing the present invention includes an outer peripheral roller 6 inside the housing 5.
, a hammer 7 and a die 3 having a tapered inner surface are sequentially installed in a Ketas saging machine 8.

A cylindrical metal fitting 9 is inserted into the die 3 at an angle θ, one end of the support rod 10 is rotatably attached to the spindle 11, and a metal tube is inserted between the metal fitting 9 and the tapered inner wall of the die 3. 2 is clamped and processed.

The relative positions of the die 3, the metal tube 2, and the fitting 9 in the above embodiment are as shown in FIG.

For example, if the spindle 12 is rotated in the direction of the arrow 13 in FIG. .

In this case, if the metal fitting 9 is placed facing the inside of the die when pressurizing the die, the desired processing can be carried out smoothly.

In the above, the angle θ of the metal fitting is freely determined by the change in the thickness of the metal tube.

For example, the state shown in FIG. 4 shows the state in which the 90-degree taper process has been completed.

Next, FIG. 6 shows a state in which the metal tube is deformed due to buckling during taper processing.

Under normal conditions, buckling would occur as shown in Figure 6 a, but according to this invention, since the metal tube is in contact with the inner wall of the metal tube, the metal tube is affected by the static inertia of the metal tube and the die. Due to this, the patient will be in a state of pressure restraint, and there is no risk of buckling.

Next, an embodiment of the method of the present invention will be described.

The outer diameter of the metal tube is 1931 nm, and the wall thickness is 1. 8mm (ratio. 1 0.93 yen), taper amount/6o, taper length 100
0mm, material steel pipe (carbon content 0.15%, tensile strength 50kg
/2) to the diameter of the fitting 1201n to the length 10
When swaging was carried out in the usual manner at a processing speed of 80 mm/sec using 00 mm, a tapered tube with the desired fan angle could be obtained without buckling.

Depending on the model of the swaging machine, the spindle that holds the die rotates at a low speed, and the housing rotates at a high speed.

In this case, the raw pipe to be processed is swaged with almost no rotation.

In such cases, the fulcrum of the metal fitting should be spherical, giving it a swinging action like a pestle.

The metal tube can be clamped between the metal fitting and the die in correspondence with the pressurizing operation of the die.

Furthermore, when molding a very long tapered tube, the spindle holding the die is fixed without rotating, and only the nozzle is rotated to repeatedly apply pressure to the die.

In these types of swaging machines, the metal tube is rotated sufficiently to perform the work, so the metal fittings, as mentioned above, do not need to be swung around like a pestle to attach to the inner wall of the tube. It gives that effect to everyone.

That is, according to this invention, the metal tube is loosely inserted into the metal tube at a predetermined angle (the same angle as the inner wall of the die) and cooperates with the die, so that a metal tube with a small tube diameter to wall thickness ratio can be shaped into a tapered shape. When processing a long tapered pipe, it is possible to process a long tapered pipe extremely easily with a relatively small pressing force, regardless of the amount of taper.

Furthermore, there is no risk of producing defective products due to processing buckling, which tends to occur in thin-walled pipes.

Further, since the pressing force may be relatively small, there is also the advantage that there is no risk of damaging the metal fittings or damaging the various parts of the swaging machine.

[Brief explanation of drawings]

FIG. 1 is a side view of the apparatus for implementing the present invention, FIGS. 2 and 3 are front views showing the mutual relationship between the mandrel and the metal tube as has been done in the past, and FIG. 4 is the metal tube in the apparatus for implementing the present invention. FIG. 5 is a side view, and FIG. 6 is a side view showing the state of buckling of the metal tube. 1... Mandrel, 2... Metal tube, 3
...Dice, 4...Chuck, 5...
...Housing, 6...Outer circumference low-y+,
7... Hammer, 8... Swaging machine, 9... Fitting, 10... Support rod, 11... Support shaft, 12...Spindle.

Claims (1)

[Claims] 1. A metal fitting parallel to the pressurizing surface of the die is inserted into the tapered swaging part formed by a plurality of dies into the inside of the metal tube to be processed in a loose state. A method for processing a metal pipe with a small diameter-to-wall thickness ratio into a tapered shape using a swaging machine, which is characterized by tapering the metal pipe using a die and a metal fitting. 2. A method for forming a metal tube with a small diameter-to-wall thickness ratio into a tapered shape using a swaging machine according to claim 1, wherein the metal fitting supports one end of the metal tube so that its angle can be adjusted. 3. A metal tube with a small pipe diameter to wall thickness ratio, characterized in that one end of a columnar metal fitting is supported at a predetermined angle, and the outer wall contact surface of the metal fitting is held parallel to the processing surface of a die, is spun. A fitting device that processes tapered shapes using an aging machine. 4. A metal tube having a small pipe diameter to wall thickness ratio according to claim 3, characterized in that the supporting rod end of the metal fitting is pivotally supported at the center of the rotary disk, is processed by a swaging machine. A fitting device that processes tapered shapes.