JPS6233017A - Mandrel for bending tube - Google Patents

Abstract

PURPOSE:To bend an inserted tube excellently by fixing annular parts together with an inserted wire rope and making outside spherical surfaces of concentric holes, outside spherical surfaces of circumferences and inside spherical surfaces of the concentric holes, inside spherical surfaces of the circumferences on fitting surfaces to the equal radii respectively. CONSTITUTION:Plural annular parts 11 with tapered holes 21 between a head part 22 and a terminal part 31 are tightly fitted by traction of a piston 56 equipped on a tension regulating device 50 through the inserted wire 42 fitted tightly with the head part 22. The centers O2 of the outside spherical surfaces 14 of the tapered holes 21 and the outside spherical surfaces 15 of the circumferences on the annular parts 11 are the same, the center O of the inside spherical surfaces 13 of the tapered holes 21 and the inside surfaces 16 of the outside circumferences are the same also. More, O1 and O2 are overlapped with respective O1, O2 of adjacent annular parts 11 and radii A1, A2 and B1, B2 are the same. Therefore, when the wire rope 42 is bent, fitting spherical surfaces are smoothly slidden and the outside spherical surfaces 17 of the circumferences on the annular parts 11 constitute a continuously curved surface. In this way, the inserted tube is bent to form excellent in sectional shape without breakings.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a mandrel for tube bending, and in particular, to a mandrel for bending a tube, in particular, a ring member of a sliding displacement mandrel is used to slide a spherical surface having a common center of curvature but different radii of curvature. By forming it as a surface, wrinkles do not occur in the tube being bent.

[Conventional technology]

Conventionally, a sliding displacement type mandrel shown in FIG. 6 has been used to bend thin-walled metal tubes that are piped for engines or air conditioning in aircraft, vehicles, etc.

This mandrel has between the starting end member 1 and the terminating end member 2,
A plurality of ring members 3 are assembled in close contact with each other on the same center line, and the wire rope 5 fixed to the starting end member 1 is inserted into the center hole 4 of each ring member 3, and the socket 6 at the other end of the wire rope 15 is inserted. A male screw 6a screwed on the outer periphery of the terminal member 2 is screwed into a female screw 7a of the mounting hole of the terminal member 2, thereby connecting each member.

The inner and outer surfaces of the ring member 3 are spherical surfaces with radii of curvature R and R2 with centers of curvature at different positions, respectively,
Both adjacent ring members 3 are shaped like a bowl.
The other inner surface is slidably abutted on one outer surface of the ring member 3a, and a spherical surface formed on the axially inner end surface of the starting end member 1 is slidably abutted on the outer surface of the final end ring member 3a. A spherical surface formed on the axially outer end surface of the starting end member 2 is slidably abutted on the inner surface of the ring member 3b at the farthest end.

The same figure shows a state in which the tube 8 is bent at a bending radius R and a bending angle of 90° using the above mandrel, and the end member 2 side of the tube 8 into which the mandrel is inserted is fixed, and the starting end When the member I side is bent, the ring member on the starting end side gradually moves and slides in the bending direction with respect to the ring member on the terminal end side, and the tube 8 is bent accordingly. It has become a mechanism.

[Problem that the invention seeks to solve]

In the above-mentioned mandrel, the tension of the wire rope is adjusted according to the predetermined bending radius and bending angle to prevent the wire rope from becoming slack, and the ring members slide while maintaining a constant gap between them. However, the sliding surface of the ring member of conventional mandrels is a spherical surface with a constant radius of curvature, and the tension of the wire rope is adjusted by screwing, so bending is not possible. If the tension of the wire rope is not properly adjusted at the start and there is slack, the bending process will be performed without adjusting the wire rope tension, which changes as the bending process progresses. As shown in Figure 6, the center of the bent wire rope (circumferential line of bending radius R) C and the center of the slidingly displaced ring member (rotation locus of the central axis line) D are misaligned. At the same time, the gap between the ring members is not constant, and a space 9 is formed in some parts.

In this way, when the wire rope is bent in a slack state, and a space 9 is created between the ring members, the portion of the tube material in contact with the space 9 will bend as shown by the arrow F in the figure.
Since the wrinkles 8 enter the space 9 under the force of the direction, the wrinkles 8
This causes damage to the tube during use. Further, since the ring member 3c on the starting end side, which is spaced apart by the space 9, receives the bending load alone, it not only deforms but also promotes the formation of wrinkles 8 in the tube.

In addition, contrary to the above case, if bending is performed with excessive tension applied to the wire rope, the wire rope may break or the fixed part at the beginning or end of the wire rope may be damaged. accidents will occur.

[Means for solving problems]

In the mandrel ring member of the present invention, inner spherical surfaces having a common center of curvature on the central axis are formed on the inner circumferential side and the outer circumferential side on the side facing the end member, and the ring member faces the other starting end member. Outer spherical surfaces having a common center of curvature at different points on the central axis are formed on the inner circumferential side and the outer circumferential side. Furthermore, between the inner spherical surface and outer spherical surface on the inner circumferential side and the inner spherical surface and outer spherical surface on the outer circumferential side, an inner tapered surface and an outer tapered surface whose diameter increases toward the axial direction of the starting end member are formed, respectively. ing.

The cross-sectional shape of the starting end member on the side facing the ring member is substantially the same as the inner and outer peripheral sides of the end member of the ring member.

The terminating member has a cross-sectional shape on the side facing the ring member that is substantially the same as the inner circumferential side and the outer circumferential side of the starting end member side of the ring member.

By combining the starting end member, the ring member, and the end member, the inner spherical surface on the inner periphery side and the inner spherical surface on the outer periphery side of one adjacent member are connected to the outer spherical surface on the inner periphery side and the outer spherical surface on the outer periphery side of the other member. The spherical surfaces are slidably abutted on each other.

(Function) In the mantle of the present invention, among the adjacent ring portions +4, the ring member on the starting end side bends the spherical surfaces on the inner circumferential side and the outer circumferential side with respect to the ring member on the terminal end side. Even when the ring member slides to a predetermined bending angle while rotating in the direction until the inner tapered surface of the ring member on the starting end comes into close contact with the outer tapered surface of the ring member on the terminal end, The spherical surfaces on the outer circumferential side maintain a state in which a portion thereof overlaps with each other.

〔Example〕

FIG. 1 is a longitudinal sectional view showing an embodiment of the mandrel of the present invention in a state before operation.
1 part is the mandrel body 10. The left part is the tension adjustment device 50.

The mandrel main body IO includes an annular member 11. Starting end member 22,
It is composed of a terminal member 31 and a wire lobe 42.

As shown in FIG. 4, the ring member 11 of the mandrel body 10 is provided with an outer wing part 15 on the radially outer side of the core part 12 via a link part 18, and on the axial center line of the core part 12. , is an annular body provided with a wire lobe insertion hole 21 that tapers in diameter toward the right side in the axial direction (toward the starting end member side).

The end face of the core part 12 of the ring part member 11 on the axial left side (terminal member side) and the inner surface of the outer wing part 15 have a radius of curvature A, with a point 01 on the central axis as a common center of curvature.
An inner spherical surface 13 with a radius of I is formed on the inner circumferential side, and an inner spherical surface 16 with a radius of curvature B is formed on the outer circumferential side.

Further, on the end face of the core part 12 of the ring part member 11 on the axially right side (starting end member side) and on the outer surface of the outer wing part 15, there is a point 0 on the central axis that is closer to the core part 12 side than the center of curvature O8. With □ as the common center of curvature, the outer spherical surface 14 with the radius of curvature A2 is on the inner peripheral side, and the outer spherical surface 17 with the radius of curvature B2 is on the inner peripheral side.
is formed on the outer circumferential side.

The above radii of curvature A1 and A2 and radii of curvature B1 and B
Regarding the correlation with 2, AI and A2 are equal and B
, and B2 are preferably set to be equal, or A is set to be slightly larger than A2, and B is set to be slightly larger than B2.

The axially left end surface and the axially right end surface of the continuous limb section 18 of the ring member 11 form an inner tapered surface 19 and an outer tapered surface 20 that expand in diameter toward the right side in the axial direction. 19 is a conical surface having the apex at the center of curvature OI, and the outer tapered surface 20 is at the center of curvature 0□
The taper angle of the inner tapered surface 19 is smaller than the taper angle of the outer tapered surface 20.

When a plurality of the ring members 10 are arranged on the same central axis and overlapped, the outer spherical surface 14 on the inner circumferential side and the outer spherical surface 17 on the outer circumferential side of the ring member on the left side in the axial direction each have an axis. The inner spherical surface 13 on the inner circumferential side and the inner spherical surface 16 on the outer circumferential side of the ring member on the right side of the direction are in close contact, and there is a gap between the outer tapered surface 20 and the inner tapered surface 19 of both ring members. The spherical surfaces of both ring members that are in close contact with each other serve as sliding surfaces.
They become mutually rotatable about the center of curvature OI.

The rotation angle of the ring member 11 is limited by the taper angle between the inner tapered surface 19 and the outer tapered surface 20, and the angle corresponding to the difference between the taper angles becomes the maximum rotation angle. When the ring member 11 rotates to the maximum angle, the lower half of the inner tapered surface 19 of the right ring member in the axial direction is in close contact with the outer tapered surface 20 of the ring member on the left side in the axial direction. The outer spherical surface 17 on the outer circumferential side of one ring member and the inner spherical surface 16 on the outer circumferential side of the other ring member are arranged so that a portion thereof remains overlapped even when the upper half is subjected to maximum sliding displacement. It has become.

As shown in FIG. 3, the starting end member 22 is an annular body having a wire lobe insertion hole 25 on the axial center line and a socket hole 26 connected to the wire lobe insertion hole 25 and opening on the right end surface in the axial direction. The inner peripheral side and inner peripheral surface of the left end surface in the axial direction of this starting end member 22 have the same radius of curvature A as that of the ring member 11.
I and B.

Inner spherical surfaces 24 and 27 having a common center of curvature at a point 01 on the central axis are respectively formed, and on the radially outer side of the inner spherical surface 24 on the inner peripheral side, there is a groove whose diameter increases toward the right in the axial direction. )<surface 30 is formed. Similar to the case of the ring member 11, this tapered surface 30 is also a conical surface having the center of curvature OI as its apex.

Also, regarding the outer peripheral surface of the starting end member 22, the ring member 11
As in the case of , an outer spherical surface 28 is formed with a radius of curvature B2 having the center of curvature at a point 02 on the central axis.

As described above, the cross-sectional shape of the axial left end surface and the inner and outer circumferential surfaces of the starting end member 22 is the same as that of the axial left end surface of the core section 12 and the connecting branch section 18 of the ring member 11 and the inner and outer surfaces of the outer wing section 15. It is formed to have almost the same shape as the cross-sectional shape.

As shown in FIG. 5, the terminal member 31 has a wire rope insertion hole 34 on the axial center line that tapers in diameter toward the right side in the axial direction, and a step-shaped hole on the left end surface in the axial direction that is connected to the wire rope insertion hole 34. It is an annular body having a center hole 40 that opens with an enlarged diameter, and a medium diameter part 35 is inserted through a stepped surface between a large diameter part 32 at the right end in the axial direction and a small diameter part 37 at the left end in the axial direction. A male thread 38 is provided on the outer peripheral surface of the small diameter portion 37.

The inner and outer circumferential sides of the right end surface in the axial direction of the large diameter portion 32 of this terminal member 31 have the same radii of curvature A2 and B2 as in the case of the ring member 11, and have a common point o2 on the central axis. Outer spherical surfaces 33 and 36 having centers of curvature are formed respectively, and radially outward of the outer spherical surface 33 on the inner peripheral side,
A tapered surface 39 is formed whose diameter increases toward the right side in the axial direction.

This tapered surface 39 is also a conical surface having the center of curvature 02 as its apex, similarly to the case of the ring member 11.

In this way, the cross-sectional shape of the right end surface in the axial direction and the outer circumferential surface of the terminal member 31 is the same as the cross-sectional shape of the right end surface in the axial direction of the core portion 12 and the connecting branch portion 18 of the ring member construction 1 and the outer surface of the outer wing portion 15. It is formed in almost the same shape.

When a plurality of the above ring members 11 are combined on the same central axis and arranged between the starting end member 22 and the end member 31, as shown in FIG. On the outer spherical surface 14 formed on the inner circumferential side of the ring member 11 and the outer spherical surface 17 formed on the outer circumferential side, the ring member 11 adjacent to the right side in the axial direction (starting end member side)
The inner spherical surface 13 formed on the inner periphery side and the inner spherical surface 16 formed on the outer periphery side are in slidable contact with each other.

Moreover, the inner spherical surfaces 24.27 on the inner and outer circumferential sides of the starting end member 22 are in a slidable state on the outer spherical surfaces 14.17 on the inner and outer circumferential sides of the annular member 11a adjacent to the starting end member 22, respectively. contact with.

Furthermore, the inner spherical surfaces 13.36 on the inner and outer periphery sides of the end member 31 are slidably connected to the inner spherical surfaces 13.36 on the inner and outer periphery sides of the ring member 11b adjacent thereto. come into contact with

Starting end members 22 combined and arranged as described above
, the plurality of ring members 11 and the terminal member 31 are connected by a wire rope 42 inserted through the wire rope insertion holes 25, 21° 34 of each member. wire rope 4
A socket 44 is attached to the starting end side of the wire rope 2 through a tapered sleeve 43, and this socket 44 is fitted and fixed in the socket hole 26 of the starting end member 22. It is pulled out from the hole 40, and a socket 46 is attached via a tapered sleeve 45, and this socket 46 is connected to a tension adjustment device 50, which will be described later.

The tension adjustment device 50 includes a cylinder tube 51 and a piston 56 that is slidably fitted into the cylinder tube 51.

The cylinder tube 51 has the same outer diameter as the large diameter portion 32 of the end member 31 of the mandrel main body 10,
The interior is divided into a front chamber 54 and a rear chamber 55 by a partition wall 52, and the axial end on the front chamber 54 side is screwed and connected to the male thread 38 of the terminal member 31 of the mandrel body 10,
An adapter 70 for attaching a pengu machine (not shown) is screwed and connected to the axial end portion on the rear chamber 55 side.

A piston 56 is slidably fitted into the rear chamber 55 of the cylinder tube 51, and a piston rod 59 integrated with the piston 56 is slidably fitted into the through hole 53 of the partition wall 52. A head 58 having a male thread 57 on the outer periphery is provided protruding from the end surface of the piston 56 on the opposite side from the piston rod 59 .

A valve core 60 is inserted into the piston 56 from this head 58.
Insert the piston rod 5 from the tip of the valve core 60.
A gas passage 61 that opens on the outer circumferential surface of 9 is provided. A hose (not shown) is connected to the male thread 57 of the head 58 of the piston 56 to direct gas through the gas passage 61 through the valve core 60.
From there, it can be fed into the rear chamber 55 of the cylinder tube 51.

Seals 62 and 63 are fitted to the outer peripheral surface of the piston 56 and the inner peripheral surface of the through hole 53 of the partition wall 52 of the cylinder tube 51, respectively, to maintain airtightness on the sliding surface between the piston 56 and the piston rod 59. , the gas sealed in the rear chamber 55 of the cylinder tube 51 is prevented from leaking.

A socket 46 to which the end of the wire row 142 is fixed and a connector 48 fixed to the socket 46 by tightening a port 47 are slidably fitted into the front chamber 54 of the cylinder tube 51. to piston rod 5
The ends of 9 are screwed together and fixed.

Next, the operating state of each member when the mandrel having the above configuration is used will be explained.

At the start of use, compressed gas such as air or nitrogen is first sent through the valve core 60 of the piston 56 of the tension adjusting device 50, and this compressed gas is filled into the rear chamber 55 of the cylinder tube 51 through the gas passage 61. As a result, the piston 56 is pressurized and slides in the backward direction (to the left in FIG. 1), and the mandrel body 1 connected to the piston rod 59
A tension is applied to the wire lobe 42 at the position 0, and the starting end member 22 is pulled toward the terminating member 31 by the socket 44 on the starting end side. Therefore, the inner spherical surfaces 24.27 of the starting end member 22 are in close contact with the outer spherical surfaces 14.17 of the adjacent ring members 11a, and similarly between the plurality of ring members 11 arranged. Ring member 11
The inner spherical surfaces 13.16 of the ring member 11 on the terminal side are in close contact with the outer spherical surfaces 14 and 17 of the ring member 11 on the terminal side, respectively, and the inner spherical surfaces 13 and 16 of the ring member 11b adjacent to the terminal member 31 are respectively in contact with the outer spherical surface 33 of the terminal member 31. Closely attached to .36.

By appropriately setting the pressure of the compressed gas filling the rear chamber 55 of the cylinder tube 51 according to the bending radius and bending angle of the mandrel body, a predetermined tension can be applied to the wire rope 42. During the bending process, the starting end member 22, the ring member 11, and the end member 31
It is possible to maintain the respective members in an appropriate close contact state and prevent the generation of gaps between the members.

FIG. 2 shows the operating state when the mandrel body of the present invention is bent to a maximum bending angle of 90° (IDR, 90°) with a bending radius R that is the same as the outer diameter D of the mandrel (inner diameter of the tube to be processed).

The ring member 11b at the final end adjacent to the end member 31 of the mandrel main body 10 rotates by a certain angle about the center of curvature 0, and accordingly, the ring member 1
The inner spherical surface 13.16 of 1b is the outer spherical surface 3 of the terminal member 31.
3. It does not slide in the direction of 36, but is displaced in the rotational direction. Similarly, regarding the plurality of ring members 11 sequentially adjacent to this ring member 11b, the ring member 11 on the starting end side adjacent to the ring member 11b on the terminal end side is centered around the center of curvature 01. The inner spherical surface 13.16 of the ring member 11 on the starting end side does not slide on the outer spherical surface 14.17 of the ring member 11 on the terminal end side, but is displaced in the direction of the rotational force. Also,
The starting end member 22 is the starting end ring member 11 adjacent thereto.
a by a certain angle around the center of curvature 01, and the inner spherical surface 24.27 of the starting end member 22 rotates against the ring member 1.
It does not slide on the outer spherical surface 14.17 of 1a, but is displaced in the rotational direction.

The above-mentioned terminal end member 31, each ring member 11 and starting end member 2
The sliding displacement between the two is calculated by the radius of curvature A, B, of the inner spherical surface of each member relative to the radius of curvature Az, Bz of the outer spherical surface of each member.
If is set to a slightly smaller value, even if the members are in close contact with each other under pressure due to the tension of the wire rope 42, the process will be performed more smoothly without experiencing large frictional resistance.

When each member has rotated to the maximum bending angle, the terminal member 3
The lower half of the inner tapered surface 19 of the adjacent ring member 11b is in close contact with the lower half of the tapered surface 39 of No. 1, and the plurality of ring members 11 sequentially adjacent to this ring member 11b are ,
In the lower half of the outer tapered surface 20 of the ring member 11 on the terminal end side,
The lower half of the inner tapered surface 19 of the ring member 11 at the starting end is in close contact with the outer tapered surface 2 of the ring member 11a, 0:) at the starting end.
The lower half of the tapered surface 30 of the starting end member 22 is in close contact with the lower half of the tapered surface 30 of the starting end member 22 .

Further, the inner spherical surface 16 on the outer circumferential side of the ring member 11b adjacent to the terminal member 31 is entirely covered with the lower half, and a part of the upper half thereof is the outer spherical surface 36 on the outer circumferential side of the terminal member 31.
Regarding the ring members 11 that overlap and are adjacent to each other, the inner spherical surface 16 on the outer circumferential side of the ring member 11 on the starting end side is the entire surface of the lower half, and the upper half is a part of the inner spherical surface 16 of the ring member 11 on the terminal end side. The outer spherical surface 17 on the outer circumferential side of the ring member 11a at the starting end overlaps with the outer spherical surface 27 on the outer circumferential side of the ring member 11.

The inner spherical surface 27 on the outer circumferential side of the starting end member 22 is in a state where the lower half overlaps the entire surface and the upper half overlaps partially.

Therefore, until the sliding displacement due to rotation of the plurality of ring members 11 is completed, the rotation locus of the center axis line is
Coupled with the fact that the bent wire rope 42 does not shift from the center, and these ring members 11 remain in close contact with each other and are kept in an overlapping state, sliding displacement occurs.
This eliminates uneven gaps between the ring members and the formation of spaces.

The tension adjustment device of the above embodiment has been described for the case where the rear chamber of the cylinder tube is filled with compressed gas to pressurize the piston, but a compression coil spring may be inserted instead of the compressed gas, or both may be used. May be used together.

〔Effect of the invention〕

As explained above, the ring member of the mandrel of the present invention has two types of spherical surfaces having a common 4° center of curvature on the inner circumferential side and the outer circumferential side as sliding surfaces, and the starting end member side and the terminal end member side. A tapered surface is formed between the spherical surfaces of the inner circumferential side and the outer circumferential side, the diameter of which increases in the axial direction of the starting end member, and the sliding surface of the starting end member is The ring member is formed to have almost the same cross-sectional shape as the end member side, and the sliding surface of the end member is
It is formed to have substantially the same cross-sectional shape as the starting end member side of the ring member. Therefore, according to the present invention, the sliding displacement when the plurality of ring members superimposed on the same central axis are rotated is performed on the inner circumferential side and the outer circumferential side, so that the rotational trajectory of the central axis is The bending radius remains aligned with the circumferential line of the bending radius, and there is no space between the ring members, so unlike conventional mandrels, wrinkles that can cause breakage occur in the bent tube. 11 Not only is it possible to process bent tubes of excellent quality, but the ring members always receive bending load while overlapping each other during bending, so they do not deform, making it a mandrel with high practical value. is obtained.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention in a state before operation, FIG. 2 is a longitudinal sectional view showing the embodiment of the invention in an operating state, and FIG. 3 shows a starting end member. , the same figure (a) is a front view of the left half, the same figure (bl is a cross-sectional view, FIG. 4 shows the ring member, the same figure (a) is a front view of the left half, and the same figure [b) is a cross-section Figures 5 and 5 show the terminal member, and the same figure [al is a front view of the left half, the same figure (bl is a sectional view, and FIG. 6 is a longitudinal sectional view showing a conventional mandrel in an operating state). In the figure, 11 is an annular member, 13.14 is an inner spherical surface on the inner circumferential side, and an outer spherical surface, 16.17 is an inner spherical surface on the outer circumference side, and an outer spherical surface, 19.20 is an inner tapered surface, an outer tapered surface, and 22 is an outer spherical surface. Starting end member, 24 is an inner spherical surface on the inner periphery side, 27, 28 is an inner spherical surface on the outer periphery side, outer spherical surface, 30 is an inner tapered surface, 31 is a terminal end member, 33 is an outer spherical surface on the inner periphery side, 36 is an outer spherical surface on the outer periphery side outer spherical surface, 39 outer tapered surface, 42 wire rope, 50
is a tension adjustment device, ol is the center of curvature of the inner spherical surface on the inner and outer circumferential sides, and 0□ is the center of curvature of the outer spherical surface on the inner and outer circumferential sides.

Claims (1)

[Claims] A plurality of ring members are arranged on the same central axis between a starting end member and a terminal end member, one end of a wire rope inserted along the central axis of each member is fixed to the starting end member, and the other end of the wire rope is fixed to the starting end member. In a tube bending mandrel connected to a tension adjustment device on the end member side, the inner and outer peripheral sides of the ring member on the side facing the end member, and the inner and outer peripheral sides on the side opposite to the starting end member. an inner spherical surface and an outer spherical surface having a common center of curvature at different points on the central axis are formed on each side, and between the inner spherical surface and outer spherical surface on the inner peripheral side and the inner spherical surface and outer spherical surface on the outer peripheral side. An inner tapered surface and an outer tapered surface each having a diameter increasing toward the starting end member are formed, and the cross-sectional shape of the side of the starting end member facing the ring member is changed to the inner and outer periphery of the end member of the ring member. The cross-sectional shape of the side of the end member facing the ring member is substantially the same as the inner circumferential side and the outer circumferential side of the start end member side of the ring member, and the starting end member, By combining the ring member and the terminal member, the inner spherical surface on the inner circumferential side and the inner spherical surface on the outer circumferential side of one adjacent member,
A mandrel for tube bending, characterized in that the mandrel is slidably abutted on an outer spherical surface on the inner circumferential side and an outer spherical surface on the outer circumferential side of the other member.