JP2020040073A - Pipe end diameter expansion/reduction device - Google Patents

Abstract

To provide a pipe end diameter expansion/reduction device which can stably stop a diameter reduction die at a prescribed position.SOLUTION: A pipe end diameter expansion/reduction device 1 comprising: a diameter expansion die 2 energized radially inward with a center axis X-X; a taper arbor 7 which is provided in a taper hole 4 formed at a central part of the diameter expansion die 2, and advances/retracts in an axial direction of the axis X-X; a diameter reduction die 10 energized radially outward with the center axis X-X; and a press die 13 which has an inside taper surface 14 fitting to an outside taper surface 11 formed on an outer periphery of the diameter reduction die 10, and advances/retracts in the axis X-X direction. A cylindrical stopper member 17, which suppresses movement to the central axis side with respect to the prescribed position, is provided in the diameter reduction die 10, and the taper arbor 7 is loosely inserted in the stopper member 17.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a device for expanding and contracting a pipe end.

  In an industrial product using a pipe, high accuracy is often required for the outer diameter of the end of the pipe in fitting and joining the pipe and another member.

  Conventionally, in order to obtain a highly accurate portion of the outer diameter of a pipe end, the pipe end is subjected to a diameter-expanding process, and thereafter, the diameter-expanded end is subjected to a diameter-reducing process. In addition, the diameter enlargement processing and the diameter reduction processing are performed by one processing apparatus in order to increase the processing efficiency.

  As shown in FIG. 7, the pipe end expanding / contracting apparatus 101 performed by one processing apparatus radially expands the enlarging die 102 for expanding the diameter by a taper arbor 103 from the inside thereof, and then reduces the diameter. When the outer diameter tapered surface 104a of the diameter mold 104 is pushed toward the centripetal side by the inner taper surface 105a of the press mold 105, the diameter-reduced mold 104 is moved in a centripetal direction (for example, Patent Document 1). reference)).

Japanese Patent No. 2587490

  In the processing using the conventional pipe end expanding / reducing apparatus 101, the processing accuracy of the outer diameter of the end 111 of the pipe 110 by the diameter reducing processing of the diameter reducing die 104 is important.

  However, in the processing apparatus 101 described in Patent Literature 1, there is no description for improving the processing accuracy of the outer diameter.

  In general, in order to stop the reduced-diameter mold 104 at a predetermined position, a dog that moves in conjunction with the reduced-diameter mold 104 and a position sensor that emits a signal in contact with the dog are used. The mold 104 is stopped at a predetermined position.

  However, in the stop position control of the reduced-diameter mold 104 using the dog and the position sensor, it is difficult to always stop the reduced-diameter mold 104 at an accurate position due to fluctuation of the dog position. There is a problem that it is difficult to stably obtain a high processing accuracy with an outer diameter of 111.

  Therefore, an object of the present invention is to propose a pipe end expanding / contracting device capable of stably stopping a diameter reducing type at a predetermined position.

In order to solve the above-mentioned problem, the present invention is directed to an expansion pipe which is inserted into an open end of a pipe, is divided into a plurality of pieces in a circumferential direction, and is urged in a radially inward direction about its axis. A radial die, and a taper arbor provided in a tapered hole formed in the center of the enlarged die and moving forward and backward in the axial direction of the shaft core;
A reduced-diameter type that is fitted around the outer periphery of the open end of the pipe, is divided into a plurality in the circumferential direction, and is urged outward in a radial direction about the axis. A die having an inner tapered surface fitted to an outer tapered surface formed on the outer periphery, and a pressing die that moves forward and backward in the axial direction of the shaft core, comprising:
A cylindrical stopper member for preventing the reduced-diameter mold from moving from a predetermined position toward the shaft center is disposed in the reduced-diameter mold, and the taper arbor is loosely inserted in the stopper member. This is a device for enlarging and reducing the diameter of a pipe end.

  Further, the stopper member may be formed by mutually connecting a plurality of constituent members divided on a plane including the axis.

  According to the present invention, by providing a cylindrical stopper member for preventing movement of the reduced-diameter type in the centripetal direction in the reduced-diameter type, the reduced-diameter type surely completes the reducing step at a predetermined position every time. Therefore, the processing accuracy of the outer diameter at the end of the pipe can be stably obtained.

FIG. 2 is a longitudinal sectional view of a pipe end diameter expanding / contracting apparatus according to an embodiment of the present invention. FIG. 2 is a longitudinal sectional view of a state in which the end of the pipe is expanded from the state of FIG. 1. FIG. 3 is a longitudinal sectional view of a state where the end of the pipe is reduced in diameter from the state of FIG. 2. FIG. 4 is a top view of the stopper member used in the embodiment of the present invention. FIG. 5 is a side view of a component constituting the stopper member of FIG. 4. The perspective view of FIG. The longitudinal section of the diameter expansion and contraction device of the pipe end concerning a prior art.

  An embodiment for carrying out the present invention will be described based on an embodiment shown in the drawings.

  FIG. 1 is a longitudinal sectional view of a pipe end expanding / contracting apparatus 1 according to an embodiment of the present invention.

  The pipe expanding / reducing device 1 at the end of the pipe has an expanding die (finger) 2, and is divided into eight parts in the circumferential direction around an axis XX located at the center of the expanding die 2. It has a mold 2a. In the present embodiment, the enlarged die 2 is constituted by the split dies 2a divided into eight pieces. However, the number of the split dies 2a constituting the enlarged dies 2 can be arbitrarily set. In addition, the split mold 2a is provided so as to be movable in a radial direction and a centripetal direction about the axis XX of the enlarged diameter mold 2. In addition, below, the upper part A of FIG. 1 is demonstrated as one of the axis XX, and the lower part B is the other.

  An enlarged-diameter molding part 3 to be inserted into the open end 21 of the pipe 20 to be machined is formed at one end A of the split die 2a in the axial center XX direction of the enlarged die 2. . At the center of the split mold 2a of the diameter-expanding mold 2, a tapered hole 4 whose diameter increases from one end A to the other B in the axis XX direction of the diameter-expanding mold 2 is formed. Is formed.

  As shown in FIG. 1, a conical taper arbor 7 is provided in the tapered hole 4, the diameter of which increases from one end to the other end in the axis XX direction of the diameter expanding die 2. The taper arbor 7 can be moved in and out of the tapered hole 4 of the large-diameter die 2 in the axis XX direction by a first drive unit (not shown). The first drive unit is driven by an arbitrary drive method such as a hydraulic cylinder and an actuator.

  Each split mold 2a of the enlarged diameter mold 2 is always urged in a radially inward direction (centripetal direction) about the axis XX of the enlarged diameter mold 2 by a first urging portion such as a spring (not shown). Have been.

  The angle of the inner surface of the tapered hole 4 and the angle of the outer surface of the tapered arbor 7 with respect to the axis XX of the diameter-expanding die 2 are substantially the same, and as shown in FIG. By moving the shaft core XX toward one A side (upper side) of the shaft core XX and inserting it into the tapered hole 4, the enlarged-diameter-side molded portion 3 of each split mold 2 a in the enlarged-diameter mold 2 is enlarged. The mold 2 is moved evenly in the radial direction about the axis XX of the mold 2, and the diameter-increase-side molding portion 3 expands its diameter. When the diameter of each split mold 2a is expanded, each split mold 2a may or may not contact a stopper member 17 described later.

  As shown in FIGS. 1 and 3, the taper arbor 7 is moved to the other B side (lower side) of the axis XX of the large-diameter die 2 by the first driving means so as to be separated from the inside of the tapered hole 4. Then, each split mold 2a is evenly moved in the centripetal direction about the axis XX of the diameter-expanding mold 2 by the urging force of the first urging portion, and the diameter-expanding-side molding portion 3 is reduced in diameter. It has become so.

  As shown in FIG. 1, a split die 10 a divided into eight pieces in the circumferential direction around the axis XX of the expanded diameter die 2 is provided radially outside each split die 2 a in the expanded die 2. The configured reduced-diameter mold 10 is provided so as to surround the outer periphery of the enlarged-diameter mold 2. In the present embodiment, the reduced-diameter die 10 is constituted by eight split dies 10a, but the number of the split dies 10a constituting the reduced-diameter die 10 can be arbitrarily set. The split mold 10a is provided so as to be movable in a radial direction and a centripetal direction about the axis XX of the diameter-expanding mold 2.

  A reduced-diameter molding part 12 that is fitted on the outer periphery of the open end 21 of the pipe 20 is formed at one end A of the reduced-diameter die 10 in the axial center XX direction of the enlarged diameter die 2. .

  At the end of one of the outer peripheral surfaces of the split dies 10a in the reduced-diameter mold 10, the outer side positioned radially outward from the one A side of the axis XX of the large-diameter mold 2 to the other B side. A tapered surface 11 is formed.

  An annular pressing die 13 is provided radially outward of the outer tapered surface 11 so as to be able to advance and retreat in the axis XX direction of the enlarged diameter die 2 by a second driving unit (not shown). Inside the pressing die 13, an inner tapered surface 14 corresponding to the outer tapered surface 11 is located radially outward as going from one A side to the other B side of the axis XX of the enlarged diameter die 2. Is formed. The inner tapered surface 14 is arranged so as to fit with the outer tapered surface 11. The second driving unit is driven by an arbitrary driving method such as a hydraulic cylinder and an actuator.

  Each split mold 10a of the reduced-diameter mold 10 is always urged radially outward with respect to the axis XX of the enlarged-diameter mold 2 by a second urging portion such as a spring (not shown).

  When the pressing die 13 is moved to the other side B of the axis XX of the diameter-enlarging die 2, the split die 10 a of the diameter-reducing die 10 is moved in the centripetal direction by the inner tapered surface 14, and the reduced-diameter forming part is formed. 12 is reduced in diameter. Also, when the pressing die 13 is moved to the one A side of the axis XX of the enlarged diameter die 2, the split die 10a of the reduced diameter die 10 is moved in the radial direction by the urging force of the second urging portion, The diameter of the reduced-diameter molding section 12 increases.

  A space portion 15 is formed between the enlarged diameter mold 2 and the reduced diameter mold 10, and a cylindrical stopper member 17 is disposed in the space portion 15. In the stopper member 17, a part of each split mold 2a of the enlarged diameter mold 2 and the taper arbor 7 are loosely inserted.

  The stopper member 17 is formed in a cylindrical shape, and is formed with rigidity and strength so as not to be deformed or broken even if it is compressed in the centripetal direction by the reduced diameter mold 10.

  As shown in FIGS. 4 to 6, the stopper member 17 is formed by connecting constituent members 17a and 17b divided by a plane passing through the center axis. In the present embodiment, the stopper member 17 is formed by connecting the two divided component members 17a and 17b so as to be separable from each other. However, the stopper member 17 is formed by separating and combining the three or more divided component members. It may be.

  As shown in FIGS. 4 to 6, the constituent members 17 a and 17 b of the stopper member 17 are provided with an engaging pin 18 and an engaging hole 19 at their joints, respectively. By engaging the member 19, the constituent members 17a and 17b can be detachably connected.

  Next, a description will be given of a method of forming the open end of the pipe using the pipe end expanding / contracting device 1.

  First, as shown in FIG. 1, the taper arbor 7 is moved to the other B side of the axis XX of the diameter expanding die 2 by the first driving unit, and the diameter of the diameter expanding die 2 is divided by the urging force of the first urging unit. The mold 2a is moved in the centripetal direction to reduce (retreat) the diameter-increased-side molding portion 3 and to move the pressing die 13 to one A side of the axis XX of the diameter-increased die 2 by the second drive portion. The splitting die 10a of the diameter reducing die 10 is moved in the radial direction by the urging force of the second urging part, and the diameter of the reduced diameter forming part 12 is increased (retracted).

  Next, within the open end 21 of the pipe 20, the enlarged diameter forming section 3 of the enlarged diameter mold 2 in the enlarged diameter reducing apparatus 1 for the pipe end is located, and the reduced diameter molding section 12 of the reduced diameter mold 10 is located. The pipe 20 is attached to the diameter increasing / reducing device 1 at the end of the pipe so as to be located on the outer peripheral portion of the open end 21 of the pipe 20.

  Next, as shown in FIG. 2, the taper arbor 7 is moved by a predetermined amount to one A side of the axis XX of the large-diameter mold 2 by the first driving unit, and the split mold 2 a of the large-diameter mold 2 is moved in the radial direction. To enlarge the diameter of the enlarged-diameter molding section 3 and the diameter of the open end 21 of the pipe 20 by a predetermined amount.

  Next, the taper arbor 7 is moved to the other B side of the axis XX of the enlarged diameter mold 2 by the first driving unit, and the split mold 2a of the enlarged diameter mold 2 is moved in the centripetal direction by the first urging unit. Then, the diameter-increase side molding portion 3 is reduced in diameter (retracted).

  Next, as shown in FIG. 3, when the pressing die 13 is moved to the other B side of the axis XX of the enlarged diameter die 2 by the second driving unit, the inner tapered surface 14 splits the reduced diameter die 10. The mold 10 a is pushed in the centripetal direction, and the diameter of the opening end 21 of the pipe 20 is reduced by the reduced-diameter molding part 12.

  Further, when the pressing die 13 is moved to a predetermined position on the other B side of the axis XX of the diameter expanding die 2, the diameter reducing die 10 comes into contact with the outer peripheral surface of the stopper member 17, and Is prevented from moving in the centripetal direction and is forcibly stopped. Thereby, the diameter reduction processing of the open end 21 of the pipe 20 is completed, and the outer diameter of the open end 21 can be formed to a desired diameter with high accuracy.

DESCRIPTION OF SYMBOLS 1 Diameter expansion / contraction device of pipe end part 2 Diameter expansion type 7 Taper arbor 10 Diameter reduction type 11 Outer taper surface 13 Push die 14 Inner taper surface 17 Stopper member 17a, 17b Component member 20 Pipe 21 Open end

Claims (2)

A large-diameter die that is inserted into the open end of the pipe, is divided into a plurality of pieces in the circumferential direction, and is urged in a radially inward direction about the axis thereof, and formed at the center of the large-diameter die A taper arbor provided in the tapered hole, and moving forward and backward in the axial direction of the shaft core,
A reduced-diameter type that is fitted around the outer periphery of the open end of the pipe, is divided into a plurality in the circumferential direction, and is urged outward in a radial direction about the axis. A die having an inner tapered surface fitted to an outer tapered surface formed on the outer periphery, and a pressing die that moves forward and backward in the axial direction of the shaft core, comprising:
A cylindrical stopper member for preventing the reduced-diameter mold from moving from a predetermined position toward the shaft center is disposed in the reduced-diameter mold, and the taper arbor is loosely inserted in the stopper member. A device for expanding and reducing the diameter of a pipe end, which is characterized in that: 2. The apparatus according to claim 1, wherein the stopper member is formed by mutually connecting a plurality of constituent members divided on a plane including an axis of the stopper member.

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