JPH06114625A - Metal pipe cutting method - Google Patents

Abstract

PURPOSE:To provide a cutting method for metal pipe, with which even a metal pipe having a considerably large hardness and wall thickness can be cut easily and quickly, even if the associate device is embodied relatively small, and also no splash attaches to the saw-teeth and the lifetime of each disc with saw-teeth can greatly be prolonged. CONSTITUTION:A metal pipe to be cut 1 is fixed, and two or more discs 2 with saw-teeth arranged at a constant spacing on one circumference at the periphery of the metal pipe 1 are rotated quickly round their own axes and moved in depth feed from the peripheral surface 3 of the metal pipe 1 till its inside surface 4. After the depth feed or simultaneously therewith, the discs 2 in high speed rotation are moved orbiting in tone circumferential direction, and thereby the pipe 1 is cut.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cutting a metal pipe, and can easily and quickly cut a metal pipe used for an outer ring (outer race) or inner ring (inner race) of a bearing made of special steel. It is related to such a method.

[0002]

2. Description of the Related Art Conventionally, there are several means for cutting a metal pipe, and typical ones are as follows. A) A metal pipe is fixed and cut with an endless band saw (see FIG. 11). (B) A metal pipe that is fixed and cut with a single disc with a rotating saw blade (see FIG. 12). C) A metal pipe is rotated and cut from both sides with two cutting tools (see FIG. 13). D) Rotating a metal pipe and cutting from both sides with two discs with cutting blades (see FIG. 14).

[0003]

However, when the metal pipe has a considerable hardness and wall thickness such as an outer ring and an inner ring of a bearing made of special steel, the conventional cutting means has the following problems. There was a point.

In the above-mentioned item (a) in which the metal pipe is fixed and cut with an endless band saw, the band saw 14 progressing as shown in FIG. 11 cuts the metal part x of the metal pipe 1 and then the hollow part y. pass. Therefore, when passing through the hollow portion y, the cutting chips at the time of cutting are attached and adhere to the saw blade. In this state, the saw blade passes through the metal portion z again to cut the saw blade. Damage and shorten the life. Further, the cut surface of the band saw 14 is difficult to be a right angle surface accurately with respect to the center line of the metal pipe 1 due to escape of the band saw 14 during cutting or the like.

In the case of fixing the metal pipe of the above b) and cutting it with one rotating disc with a saw blade, as shown in FIG. 12, the disc 2 with a saw blade is used as in the case of the above a). When passing through the hollow portion of the metal pipe 1, the cutting powder at the time of cutting the metal portion is first caught and adheres to the saw blade. Therefore, the saw blade is damaged when passing through the metal part again and the life is shortened. In addition, in order to cut the metal pipe 1 with the circular plate 2 having a saw blade, the circular disc 2 having a saw blade must have a radius twice as large as that of the metal pipe 1 or larger, and the apparatus becomes large.

In the above-mentioned c) in which the metal pipe is cut from both sides with two cutting tools, the metal pipe 1 needs to be rotated as shown in FIG. 13, so that the metal pipe 1 has a large diameter and a large weight. In this case, the device must be rotated, which makes the device large and unreasonable. In addition, when the metal pipe 1 is rotated, it will shake at the cut portion due to warping, etc.
5 is easily damaged and the life is shortened.

As shown in FIG. 14, the metal pipe 1 having a large diameter has a large diameter as in the case of the above-mentioned c), as shown in FIG. Even in the case of heavy weight, it is necessary to rotate it, which makes the device large and unreasonable. Further, the metal pipe 1 is shaken at the cutting portion due to warping or the like, and the disc 16 with a cutting edge is easily damaged by the occurrence of vibration, and the life is short. Furthermore, this disc with cutting edge 16
A large edge sag (burr) occurs on the cut surface due to.

An object of the present invention is to solve the problems of the above-mentioned conventional metal pipe cutting means. That is, the object of the present invention is to make it possible to easily and quickly cut even a metal pipe having a considerable hardness and wall thickness, and to prolong the life of the saw blade without chips adhering to it even though it is a relatively small device. Another object of the present invention is to provide a method for cutting a metal pipe that can obtain a highly accurate cut surface.

[0009]

A first method of cutting a metal pipe according to the present invention is to fix a metal pipe 1 to be cut, and to equip the outer circumference of the metal pipe 1 at equal intervals. 2 or more discs with saw blades placed

While rotating at high speed, the metal pipe 1 is cut and moved from the outer peripheral surface 3 to the inner peripheral surface 4,

After that, the two or more circular plates 2 with saw blades that rotate at high speed are orbitally moved in the circumferential direction by at least the angle α obtained by dividing the circumference by the number of the circular plates 2 to revolve the metal. The pipe 1 is cut.

Next, in the second method of cutting a metal pipe according to the present invention, the metal pipe 1 to be cut is fixed and arranged at equal intervals on the same circumference of the outer periphery of the metal pipe 1.
2 or more circular plates with saw blades,

While rotating at high speed, while cutting and moving from the outer peripheral surface 3 to the inner peripheral surface 4 of the metal pipe 2,

At the same time, the metal pipe 1 is cut by revolving the two or more circular plates 2 with saw blades that rotate at high speed in the circumferential direction.

In the above structure, the circular plate 2 with saw blade is 2
The number of sheets or more is usually up to about 10, but the larger the outer diameter of the metal pipe 1 to be cut and the smaller the wall thickness, the larger the number of sheets can be made, while the amount of revolution movement is small. You may

[0016] To move the circular plate 2 with saw blades by cutting so as to reach the inner peripheral surface 4 from the outer peripheral surface 3 of the metal pipe 1 is such that a part of the saw blades 4 is slightly visible from the inner peripheral surface 4. It means to move by cutting.

In the first cutting method, the circular disc 2 with saw blades is revolved in the circumferential direction by at least the angle α obtained by dividing at least the circumference by the number of circular discs 2, in other words, the metal pipe. It means revolving at least an arc portion obtained by dividing the length of the circumference of a circle concentric with 1 by the number of discs 2. This amount of revolution movement indicates the minimum amount of revolution movement, and needless to say, may be more than that.

The relationship between the cutting movement and the revolution movement is that, as in the first cutting method, the saw blade disc 2 is moved until it reaches the inner peripheral surface 4 of the metal pipe 1, and then in the circumferential direction. In the case of starting the revolution movement, and in the case of moving the discs 2 with saw blades toward the inner peripheral surface 4 of the metal pipe 1 while cutting and moving the disc 2 with the saw blades in the circumferential direction at the same time as in the second cutting method. There is.

The metal pipe 1 is not limited to the one having a considerable hardness and wall thickness as used for the outer ring and inner ring of the bearing made of special steel, but widely means a metal pipe. In the figure, 2a, 2b, and 2c show discs with saw blades when the number of discs 2 with saw blades is three. Further, 5 is a notched portion, 6 is an uncut portion, 7 is a disk-shaped substrate, 10 is a holding member, and 13 is a brush for cleaning a saw blade.

[0020]

[Action]

A First, the first cutting method according to the present invention, that is, two or more discs 2 with saw blades are attached to the outer peripheral surface 3 of the metal pipe 1.
A case will be described in which after cutting and moving from the to the inner circumferential surface 4, the cutting is performed by orbital movement in the circumferential direction.

The metal pipe 1 to be cut is clamped and fixed so as not to rotate, and the outer peripheral portion of the metal pipe 1 is
Two or more discs 2 with saw blades arranged at equal intervals on the same circumference are moved while cutting at high speed. By moving each circular plate 2 with a saw blade from the outer peripheral surface 3 of the metal pipe 1 to the inner peripheral surface 4, a deep notch reaching the inner peripheral surface 4 at two or more locations on the outer peripheral portion of the metal pipe 1. The part 5 is cut (see FIG. 2).

Deep cut portion 5 up to the inner peripheral surface 3
Disk 2 with each saw blade that rotates at high speed after forming
Is revolved in the circumferential direction at least by an angle α obtained by dividing the circumference of the metal pipe 1 by the number of the disks 2. By the orbital movement of the circular plate 2 with saw blades, the deep cut portions 5 up to the inner peripheral surface 4 are continuously cut and formed in the circumferential direction of the metal pipe 1 (see FIG. 3).

The revolution movement of each circular plate 2 with saw blades is
As described above, when the circumference of the metal pipe 1 is divided by the number of the discs 2 by an angle α, the discs with saw blades 2 eliminate the uncut portion, and the deep cut portions 5 are adjacent to each other. It will be in communication (see FIG. 4). With this, the deep cut portion 5 from the outer peripheral surface 3 to the inner peripheral surface 4 of the metal pipe 1 is formed over the entire circumference, and the metal pipe 1 is cut.

B Next, the second cutting method according to the present invention, that is, while cutting and moving the two or more discs 2 with saw blades from the outer peripheral surface 3 to the inner peripheral surface 4 of the metal pipe 1, At the same time, the case of revolving in the circumferential direction and cutting is described.

The metal pipe 1 to be cut is sandwiched and fixed so as not to rotate, and the outer peripheral portion of the metal pipe 1 is
The notch movement is started while rotating two or more circular plates with saw blades 2 arranged at equal intervals on the same circumference at high speed. By this cutting movement, cutting starts toward the inner peripheral surface 4 at two or more locations on the outer peripheral portion of the metal pipe 1 and the notched portion 5 begins to be formed, but at the same time, a circle with saw blades that rotate at high speed. The plate 2 is revolved in the circumferential direction (see FIG. 6).

By the orbital movement at the same time as the above-mentioned cut movement, each cut portion 5 is cut gradually deeper toward the inner peripheral surface 4 of the metal pipe 1 and longer in the circumferential direction (FIG. 6, FIG. 6). 7). When each notched portion 5 becomes deeper to the inner peripheral surface 3 due to the notch movement and the revolution movement of each saw blade disc 2, each notched portion 5 becomes substantially continuous with each adjacent notched portion 5 (Fig. 7). reference).

However, in the second cutting method described above, a large uncut portion 6 occurs particularly at the beginning of cutting. Therefore, the circular plate 2 with saw blades is allowed to continue to revolve a little more with the cutting movement stopped. With this, the remaining part 6
Is cut, and the deep cut portions 5 are communicated with each other adjacent to each other (see FIG. 8), and a deep cut 6 from the outer peripheral surface 5 to the inner peripheral surface 3 of the metal pipe 1 is formed over the entire circumference, The metal pipe 1 is cut.

C In the first cutting method and the second cutting method described above, the cutting movement of each saw blade disc 2 is performed from the outer peripheral surface 3 to the inner peripheral surface 4 of the metal pipe 1, that is, with each saw blade. A part of the saw blade of the disc 2 is only slightly visible from the inner peripheral surface 4 of the metal pipe 1, and revolves in the circumferential direction after or after the cutting movement.

Therefore, the saw blade of each circular disc with saw blade 2 is
Unlike the conventional case, the metal pipe 1 does not pass through the hollow portion during cutting, and the metal pipe 1 is always rotated and moved while being cut. Therefore, unlike the conventional case, the cutting chips are not involved in the saw blade and attached to the saw blade, and the saw blade is always cut in the state where the chips are not attached, so that the saw blade is not easily damaged. Each of the circular plates 2 with saw blades has a life as long as that when cutting a metal rod, for example.

On the other hand, since the metal pipe 1 is cut by two or more circular plates 2 with saw blades, compared to the case where one circular plate with saw blades cuts and cuts the metal pipe, The required time is greatly reduced and the cutting speed is faster.

Further, since the cutting movement of each disc 2 with saw blades may be performed by the thickness from the outer peripheral surface 3 to the inner peripheral surface 4 of the metal pipe 1, each disc 2 with saw blades has a large diameter. The size of the entire device is reduced as well, because a small diameter is used.

Further, in the present invention, the metal pipe 1 is fixed and cut / cut, and it is not necessary to rotate the metal pipe 1. Therefore, even if the metal pipe is large in diameter and heavy in weight, there is no problem. Further, due to warping of the metal pipe or the like, no shake occurs during rotation, and this surface also extends the life of the circular plate 2 with a saw blade.

In addition, in the cutting with each disc 2 having a saw blade, no edge sagging occurs on the cut surface, and there is no escape of the disc 2 having a saw blade like a band saw at the time of cutting, so that the cut surface is a metal pipe. It is a plane perpendicular to the center line of 1 accurately.

When the metal pipe 1 has a large wall thickness, the cutting resistance becomes large when the disc 2 with saw blades is used for cutting. In that case, the first cutting method may be used,
The above-mentioned No. 2 for simultaneously rotating and revolving each disc 2 with saw blades
According to this cutting method, the cutting can be performed more efficiently.

[0035]

1 to 4 show the steps of the first cutting method according to the present invention, and FIGS. 5 to 8 show the steps of the first cutting method. And FIG.9 and FIG.10 shows the outline of the apparatus which implements the cutting method which concerns on this invention.

In order to fix or feed the metal pipe 1 to be cut, a pipe fixing chuck 8 for clamping the vicinity of the cut portion is provided, and the chuck 8 is rotated by a feed screw (not shown) rotated by a motor. Moves forward and backward for each cutting, feeds the metal pipe 1 by a fixed length, and clamps and fixes it at a predetermined position.

Two or more circular plates with saw blades 3 are used here, and the circular plates with saw blades 2a, 2b, 2c are used.
Are arranged at equal intervals on the same circumference on the surface of the disk-shaped substrate 7 provided on the same line as the center line of the metal pipe 1.

That is, the disc-shaped substrate 7 is provided so as to be on the same line as the center line of the metal pipe 1 to be cut, and the disc-shaped substrate 7 can be rotated by a motor (not shown) for revolution movement. . The holding members 10 are provided at three positions on the same circumference at equal intervals near the outer circumference on the surface of the disk-shaped substrate 7, and the holding members 10 are cut and moved by the cylinders 11 for movement. It is possible to move toward the center of 7. The holding members 10 are provided with the discs 2a, 2b, 2c with saw blades, and can be rotated by the motors 12 for high-speed rotation.

The above-mentioned three discs 2a, 2b with saw blades,
The cutting movement of 2c is from the outer peripheral surface 3 to the inner peripheral surface 4 of the metal pipe 1, and the movement amount of each holding member 10 can be adjusted according to the outer diameter and the inner diameter of the metal pipe 1 to be cut.

The above-mentioned discs 2a, 2b with saw blades,
In the first cutting method, the revolving movement of 2c is at least the angle obtained by dividing the circumference of the metal pipe 1 by the number of discs 2, that is, the three discs 2a, 2b, 2c with saw blades. In the illustrated embodiment, one 360 degrees divided by 3 is 120.
The disk-shaped substrate 7 is rotatable so that it can be revolved at least by a degree (see FIG. 4).

The orbital movement of the discs 2a, 2b, 2c with saw blades in the second cutting method is performed by the disc 2 with saw blades.
Even after the cutting movement of a, 2b, 2c to the inner peripheral surface 4 is stopped,
I'm trying to continue a little longer. This is a metal pipe 1
This is because each of the uncut portions 6 is generated (see FIG. 7), and when each of the saw blade discs 2a, 2b, 2c revolves a little further, each of the uncut portions 6 is moved to the adjacent saw blade circle. The plate 2 is cut and removed, and the cut portion 5 is formed over the entire circumference of the metal pipe 1.

The brush 13 for cleaning the saw blade is for removing the chips adhering to the saw blade, and is provided so as to come into contact with the outer peripheral portions of the discs 2a, 2b, 2c with saw blades. is there.

[0043]

As is clear from the above, according to the method for cutting a metal pipe of the present invention, even if the metal pipe has a considerable hardness and wall thickness, it is a relatively small device,
The cutting can be performed easily and quickly, the cutting blade does not adhere to the cutting chips, the life of the disc with the saw blade can be extended, and a highly accurate cut surface can be obtained.

That is, in the method for cutting a metal pipe according to the present invention, two or more circular plates with saw blades are rotated at high speed, and the discs are cut and moved by an amount corresponding to the wall thickness of the metal pipe, and in the circumferential direction. It is revolved and cut.

Therefore, since each circular disc with a saw blade does not pass through the hollow portion during cutting and is constantly rotated and moved while cutting the metal pipe, it is possible to prevent chips from adhering to the saw blade. This can be prevented and the life of the disc with saw blade can be greatly extended.

Further, since two or more discs with saw blades are revolved for cutting and cutting, the time required is significantly longer than that of the conventional one using one disc with saw blades. Can be shortened.

Since the cutting movement amount is further reduced,
Since it is not necessary to make the circular plate with saw blade large in diameter and it is not necessary to rotate a large-diameter and heavy metal pipe, the entire apparatus can be downsized and there is no difficulty.

Moreover, since the metal pipe is not rotated, there is no wobbling during rotation due to warping of the metal pipe and the life of the circular disk with saw blade can be extended also from this aspect. Further, since the cutting surface is a circular plate with a saw blade, the end surface does not sag, and it is possible to accurately cut into a right-angled surface.

When the wall thickness of the metal pipe is large and the cutting resistance is large, the metal pipe can be cut by the first cutting method of the present invention. According to the cutting method of No. 2, it is possible to overcome the cutting resistance and cut more efficiently.

[Brief description of drawings]

FIG. 1 is a front view showing a state before the start of cutting in a first method for cutting a metal pipe according to the present invention.

FIG. 2 is a front view showing a state after the discs with saw blades are cut and moved from the state shown in FIG.

FIG. 3 is a front view showing a state in which the circular plates with saw blades are revolving from the state shown in FIG. 2;

FIG. 4 is a front view showing a state where the circular plates with saw blades further revolve from the state shown in FIG. 3 to cut the metal pipe.

FIG. 5 is a front view showing a state before the start of cutting in the second metal pipe cutting method according to the present invention.

FIG. 6 is a front view showing a state in which the circular plates with saw blades have started cutting movement and revolution movement from the state shown in FIG. 5;

FIG. 7 is a front view showing a state in which the circular plates with saw blades have almost completed the cutting movement from the state shown in FIG. 6;

FIG. 8 is a front view showing a state in which the circular plates with saw blades further revolve from the state shown in FIG. 7 to cut the metal pipe.

FIG. 9 is a schematic front view of an apparatus used for carrying out the method for cutting a metal pipe according to the present invention.

FIG. 10 is a schematic side view with a part of the apparatus shown in FIG. 9 omitted.

FIG. 11 is a front view showing a conventional means using a band saw.

FIG. 12 is a front view showing a conventional means using one circular plate with a saw blade.

FIG. 13 is a front view showing a conventional means using two cutting tools.

FIG. 14 is a front view showing a conventional means using two discs with cutting blades.

[Explanation of symbols]

1-Metal pipe 2-Disc with saw blade 3-Outer peripheral surface 4-Outer peripheral surface 5-Notched portion 6-Uncut portion 7-Disc substrate 8-Chuck 10-Holding member 11-Cylinder 12-Motor 13-Brush α − Angle

Claims (2)

[Claims] 1. A metal pipe 1 to be cut is fixed,
The two or more circular plates 2 with saw blades, which are arranged at equal intervals on the same circumference of the outer peripheral portion of the metal pipe 1, are cut and moved while rotating at high speed from the outer peripheral surface 3 to the inner peripheral surface 4 of the metal pipe 1. After that, the two or more circular plates 2 with saw blades that rotate at high speed are orbitally moved in the circumferential direction by at least the angle α obtained by dividing the circumference by the number of the circular plates 2 to form a metal pipe. 1. A method for cutting a metal pipe, which is characterized in that 1. 2. A metal pipe 1 to be cut is fixed,
Moving two or more circular plates 2 with saw blades arranged at equal intervals on the same circumference of the outer periphery of the metal pipe 1 while rotating at high speed until the outer peripheral surface 3 of the metal pipe 2 reaches the inner peripheral surface 4 At the same time, the metal pipe 1 is cut at the same time by revolving the two or more circular plates with saw blades 2 that rotate at high speed in the circumferential direction, and cutting the metal pipe 1. .