JP4869098B2 - Tube expansion cutting device and tube expansion cutting method - Google Patents

Description

  The present invention relates to a pipe expanding and cutting apparatus and a pipe expanding and cutting method for simultaneously performing a pipe expanding process for expanding the diameter of a pipe body to a predetermined dimension and a cutting step of cutting at an arbitrary cutting position in the axial direction.

  Some metal pipe bodies require highly accurate finished dimensions and roundness. For this reason, conventionally, as a method for manufacturing a tubular body, there has been a pipe expansion process for expanding the diameter of the tubular body formed with a diameter smaller than the finished size. A tube expansion device is used for the tube expansion process.

The pipe expansion device is made by bending a metal flat plate into a cylindrical shape with the end faces in the circumferential direction being butted, welding the butted parts, and moving the plurality of dies inserted inside to the outside in the radial direction to spread them. Thus, a desired dimension is finished (for example, refer to Patent Document 1). The tube obtained by the tube expansion process is cut into a desired length to obtain a product.
Japanese Patent Publication No. 7-80086

  However, in the conventional tube expansion device, the cross section of the tube body can be finished with high dimensional accuracy and roundness, but the axial length cannot be cut to a desired length. For this reason, it has been necessary to transport the semi-finished product tube expanded by the tube expansion device to the cutting device and cut it at an arbitrary cutting position in the axial direction, which complicates the work. In addition, it is necessary to provide a pipe expanding device and a cutting device for manufacturing the tube, and there is a problem that a space necessary for installing the device is enlarged.

  It is an object of the present invention to simultaneously cut a pipe body to a desired length at the time of pipe expansion processing, simplify the pipe manufacturing operation, and reduce the installation space of the apparatus and the pipe expansion cutting method. Is to provide.

  In order to solve the above problems, the present invention includes a plurality of inner cutter dies, a moving mechanism, and an outer cutter. The plurality of inner cutter dies are inserted into the tube body in a state of being arranged along the circumferential direction of the tube body. The moving mechanism reciprocates the plurality of inner cutter dies along the radial direction at the same speed. The outer blade has an annular shape whose inner peripheral surface is equal to the outer peripheral surface before expansion of the tube body, and one side surface is disposed at a position close to one end surface of the inner blade die across the cutting position, and is externally fitted to the tube body. To do.

  When a plurality of inner blade dies are inserted into the tube body and the plurality of inner blade dies are moved outward along the radial direction by the moving mechanism, the tube body is expanded and the plurality of inner blade dies and outer blades The tubular body is cut by the radial shearing force acting on the tube. The tube expansion process and the cutting process are performed simultaneously with a single device.

  The inner surface of each of the plurality of inner blade dies is configured by an inclined surface inclined along the axial direction, and the moving mechanism is a cone having an inclined surface that contacts the inner surface of each of the plurality of inner blade dies. It is also possible to include a cone that can reciprocate along the direction.

  By moving the cone in the axial direction, the plurality of inner cutter dies reciprocate along the radial direction at the same speed. A plurality of inner cutter dies can be operated with a simple configuration.

  Furthermore, you may provide the rotation mechanism which rotates several inner blade dies around the axis of a tubular body. The rotation mechanism rotates the plurality of inner blade dies about the axis of the tube body before the outer peripheral surface of the plurality of inner blade dies reaches the outer peripheral surface of the tube body after reaching the inner peripheral surface of the tube body.

  When the plurality of inner cutter dies move outward along the radial direction, a gap is formed between each of the plurality of inner cutter dies. The plurality of inner cutter dies move in the radial direction and the outer peripheral surface of each inner cutter die reaches the inner peripheral surface of the tube, and then the inner cutter dies are rotated before reaching the outer peripheral surface of the tube. Thus, the plurality of inner cutter dies come into contact with the tubular body even in the gap portion. The tubular body contacts the plurality of inner cutter dies over the entire circumference. The tube can be expanded uniformly over the entire circumference.

  According to the present invention, a plurality of inner blade dies are inserted into the tube body, and the plurality of inner blade dies are moved outward along the radial direction by the moving mechanism, so that the tube body is expanded at the same time. The tube body can be cut by a radial shearing force acting on the tube of the blade die and the outer blade. The tube expansion process and the cutting process can be performed simultaneously with a single device, so that the manufacturing work of the tube can be simplified and the installation space of the device can be reduced.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a front view of a tube expanding and cutting device 10 according to an embodiment of the present invention. FIG. 2 is a side sectional view of the tube expanding and cutting device 10. The pipe expanding and cutting device 10 performs a cutting process for cutting the end of the pipe body 100 at a predetermined cutting position S in the X-axis direction simultaneously with the pipe expanding process for expanding the diameter of the pipe body 100. The cutting position S is set to a position at a distance W from one end of the tubular body 100. The pipe expanding and cutting device 10 includes eight inner cutter dies 1, outer cutters 2, and cones 38 as an example.

  As an example, the outer blade 2 is made of die steel (such as SKD11), and the inner peripheral surface has an annular shape that is equal to the outer peripheral surface of the tube body 100 before the pipe expansion, and the side surface 21 is brought close to the cutting position S so Fits outside. As an example, the outer cutter 2 is held by the holder 4 via four fixing bolts 5.

  The holder 4 is formed with a hole 41. The hole 41 penetrates the holder 4 in the X-axis direction and is arranged concentrically with the outer blade 2. The inner diameter of the hole 41 is made equal to the outer diameter of the tube body 100 after tube expansion.

  Each of the eight inner cutter dies 1 has a cylindrical shape equally divided along the circumferential direction, and has a predetermined gap between the cutting position S and the side surface 21 of the outer cutter 2 in the X-axis direction. Is provided in the tube 100. The inner cutter dies 1 are arranged in close contact with each other in the circumferential direction. For example, die steel (SKD11 or the like) is used as a raw material, and the outer surface is configured by an arc surface having a smaller diameter than the inner diameter of the tube body 100 before the tube expansion. The inner surface is configured by an inclined surface 13 inclined along the X-axis direction. The inclined surface 13 is inclined so that the radial distance from the central axis parallel to the X-axis direction is wide on the front side and narrow on the back side.

  Each inner cutter die 1 is integrally provided with a flange portion 11 on the back side. Each of the inner cutter dies 1 is supported by the flange 11 so as to be movable along the radial direction of the tube 100 on the support 6. Each inner cutter die 1 has a groove 12 formed on the inner surface over the entire length in the X-axis direction.

  The support 6 is located on the back side of the holder 4. As an example, four spacers 7 are fixed to the back surface of the holder 4 via four fixing bolts 8. Each spacer 7 defines a distance between the holder 4 and the support 6. The length of the spacer 7 in the X-axis direction is determined according to the cutting distance W of the tubular body 100. A cover 61 in which a hole 62 is formed is attached to the front surface of the support 6 via a fixing bolt 63. The hole 62 is disposed concentrically with the outer blade 2 and the hole 41. The holder 4 together with the spacer 7 can be separated from the support 6 along the X-axis direction.

  The cone 3 has an octagonal cross section as an example, and the outer surface is configured by an inclined surface 32 that abuts against the inner surface of the inner cutter die 1. The inclined surface 32 is inclined so that the radial distance from the central axis parallel to the X-axis direction is wide on the front side and narrow on the back side. Eight keys 31 are attached to the cone 3 at equal intervals along the circumferential direction. Each key 31 is fitted in the groove 12 of each inner cutter die 1. Similarly to the inner blade holder 1, the cone 3 can be divided into eight parts in the circumferential direction.

  The cone 3 is fixed to the peripheral surface of the slide shaft 9. The slide shaft 9 reciprocates along the X-axis direction by a hydraulic mechanism 91, for example. The cone 3, the slide shaft, and the hydraulic mechanism 91 correspond to the moving mechanism of the present invention.

  The tube expansion / cutting device 10 is provided with a motor 92. The motor 92 supplies rotation to the slide shaft 9 via a transmission member such as a belt or a gear. The motor 92 constitutes the rotation mechanism of the present invention together with the transmission member. When the slide shaft 9 rotates, the inner cutter die 1 also rotates around the axis of the tube body 100.

  In addition, you may use materials other than die steel for the raw material of the inner cutter die 1 and the outer cutter 2 in consideration of the raw material of the pipe body 100 to be expanded and cut. Further, the inner cutter die 1 is not limited to eight equally divided in the circumferential direction. Further, the outer cutter 2 can be divided into a plurality of parts along the circumferential direction.

  When the tube body 100 is expanded and cut, as shown in FIG. 2, the slide shaft 9 is moved to the frontmost position in the X-axis direction, and the tube body 100 is moved from the front side of the holder 4 to the outer blade 2, The holes 41 and 62 are sequentially penetrated. Accordingly, the eight inner cutter dies 1 face the inner peripheral surface of the tube body 100.

  FIG. 3 is a side cross-sectional view showing a state of the tube expanding and cutting device 10 when the tube body 100 is expanded and cut. When the slide shaft 9 is moved to the back side along the X-axis direction from the state shown in FIG. 2, the key 31 moves to the back side while sliding in the groove 12, and the inclined surface 13 of each inner cutter die 1 is moved. It is pressed in the radial direction by the inclined surface 32 of the cone 3. As a result, the inner cutter dies 1 move at the same speed in the radial direction and press the inner peripheral surface of the tube body 100 outward to expand the tube body 100.

  The tubular body 100 is expanded until the outer peripheral surface comes into contact with the inner peripheral surface of the hole 41 of the holder 4. At this time, since the front surface of the inner cutter die 1 is located close to the rear surface of the outer cutter 2 with the cutting position S in between, the outer peripheral side end of the front surface of the inner cutter die 1 faces the rear surface of the outer cutter 2. To do. The tubular body 100 is cut by receiving a shearing force from the inner blade die 1 and the outer blade 2 at the cutting position S.

  In the state shown in FIG. 1, the eight inner cutter dies 1 are in close contact with each other in the circumferential direction. The tube expansion work is to expand the diameter of the tube body 100 by about 1%. Therefore, when the inner cutter dies 1 are moved outward along the radial direction, the circumferential gap between the inner cutter dies 1 is small, and the tubular body 100 can be cut over the entire circumference.

  However, in order to make the cut surface of the tubular body 100 smooth, a circumferential gap generated between the inner cutter dies 1 becomes a problem. Therefore, each inner cutter die 1 moves in the radial direction, and the outer peripheral surface of each inner cutter die 1 comes into contact with the inner peripheral surface of the tubular body 100 and before reaching the outer peripheral surface of the tubular body 100 (FIG. 4 (A ), The motor 92 is driven, and each inner cutter die 1 is rotated together with the slide shaft 9.

  The rotation angle of the slide shaft 9 at this time is an angle that does not coincide with an integral multiple of the circumferential division angle by the plurality of inner cutter dies 1. For example, in this embodiment, since the circumference is divided by eight inner cutter dies 1 and the division angle is 45 degrees, as an example, as shown in FIG. Rotate 5 degrees. When the slide shaft 9 is rotated at an angle that is an integral multiple of 45 degrees, which is the division angle, the position of each inner blade die 1 after rotation matches the position of each inner blade die 1 before rotation, and is the same before and after the rotation. This is because a gap is formed at the angular position.

  After rotating the inner cutter dies 1 together with the slide shaft 9, each inner cutter die 1 is moved in the radial direction until the outer peripheral surface of each inner cutter die 1 is exposed to the outside of the tube body 100 as shown in FIG. The tube 100 can be expanded and cut by smoothing the cut surface.

  In this way, according to the tube expanding and cutting device 10, the tube 100 can be cut while being expanded, and the tube expanding and cutting steps for the tube 100 can be performed simultaneously with a single device. The manufacturing work of 100 can be simplified and the installation space of the apparatus can be reduced.

  When the expansion and cutting of the tubular body 100 are completed, the cone 3 is moved to the front side as shown in FIG. A pressing force toward the outside in the radial direction does not act on each inner cutter die 1. Each of the inner cutter dies 1 is moved inward in the radial direction to a position where the inner cutter dies 1 are in close contact with each other in the circumferential direction by the elastic force of the elastic body provided in the support body 6.

  Thereafter, the slide shaft 9 is rotated in the opposite direction to the original angular position, and the holder 4 and the spacer 7 are moved to the front side along the X-axis direction so as to be separated from the support 6. The tube body 100 expanded to a predetermined diameter and cut to a predetermined length can be taken out from the tube expansion / cutting device 10.

  When the outer cutter 2 is divided into a plurality along the circumferential direction, as an example, the outer cutter 2 is divided into eight equal parts in the circumferential direction like the inner cutter die 1, and the outer cutters 2 are approached and separated from each other by an inclined surface, for example. To be configured. The division positions of the outer cutter 2 are arranged so as not to coincide with the division positions of the inner cutter die 1. The inner cutter dies 1 are moved in directions away from each other, and at the same time, the outer cutters 2 are rotated in the same direction as or opposite to the inner cutter dies 1 around the axis of the tube body 100 while approaching each other.

  In addition, all said embodiment is an example, This invention is not limited to these, A various change can be added within the scope of this invention.

It is a front view of tube expansion cutting device 10 concerning an embodiment of this invention. It is side surface sectional drawing of the pipe expansion cutting device. It is side surface sectional drawing which shows the state of the pipe expansion cutting device 10 at the time of pipe expansion and cutting of the tubular body 100. It is a front view of the pipe expansion cutting device 10 which shows the state of the inner blade die 1 at the time of pipe expansion and cutting of the tubular body 100.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inner blade die 2 Outer blade 3 Cone 4 Holder 6 Support body 7 Spacer 10 Tube expansion cutting device 100 Tube body

Claims (4)

A tube expanding and cutting device that expands the tube body in the radial direction and cuts the tube body at a predetermined cutting position in the axial direction,
A plurality of inner blade dies inserted into the tube body in a state of being arranged along the circumferential direction of the tube body, and the plurality of inner blade dies are reciprocated along the radial direction at the same speed. And a moving mechanism that has an annular shape whose inner diameter is equal to the outer diameter before expansion of the tubular body, and one side surface is disposed at a position close to one end surface of each of the plurality of inner cutter dies with the cutting position interposed therebetween. An outer blade that fits around the tube body,
When each of the plurality of inner cutter dies is moved outward along the radial direction, the tubular body is cut by a radial shearing force acting between the plurality of inner cutter dies and the outer cutter. Expanded cutting device. Each of the plurality of inner cutter dies is an inclined surface whose outer surface faces the inner peripheral surface of the tubular body, and whose inner surface is inclined along the axial direction,
2. The tube expansion according to claim 1, wherein the moving mechanism includes a cone having an inclined surface that abuts on an inner surface of each of the plurality of inner cutter dies, and is reciprocally movable along the axial direction. Cutting device.   Before each of the plurality of inner cutter dies moves outward along the radial direction and the outer peripheral surface of the plurality of inner cutter dies reaches the inner peripheral surface of the tube, before reaching the outer peripheral surface of the tube The tube expansion cutting device according to claim 1, further comprising a rotation mechanism that rotates the plurality of inner cutter dies about the axis of the tube body. An annular outer cutter whose inner diameter is equal to the outer diameter before expansion of the tubular body, and a plurality of inner cutter dies inserted into the tubular body in a state of being arranged along the circumferential direction of the tubular body. A tube expansion cutting method for expanding the tube body in the radial direction and cutting at a predetermined cutting position in the axial direction,
The outer cutter is fitted on the outer peripheral surface of the tube so that one side surface is close to the cutting position, and the plurality of inner cutter dies are positioned between the outer cutter in the axial direction inside the tube. Are moved outwardly along the radial direction at positions having a predetermined interval sandwiching the cutting position, and before the outer peripheral surfaces of the plurality of inner cutter dies reach the outer peripheral surface of the tubular body, Rotating a blade die around an axis of the tubular body, and cutting the tubular body by a radial shearing force acting between the outer blade and the inner blade while expanding the tubular body. Cutting method.

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