JP3425459B2 - Mandrel device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is mainly applied to a pipe diameter of 30 m /
When processing a metal pipe material with a relatively small diameter of about m or less by the draw bend method (pull bending), the rear end is fixed to the bending device, and the front end side is inserted into the pipe material of the bending portion and the bending portion is positioned. The present invention relates to a mandrel device used for preventing crushing deformation in a machine.

[0002]

2. Description of the Related Art Conventionally, as a mandrel device of this type, as shown in FIG. 4, a core member (provided at the tip of a support rod (11) in connection with the fact that the mandrel device must be replaced if necessary. 12) was connected by mutual screwing (13).

[0003]

However, in the conventional technique as described above, since the connecting structure by the mutual screwing (13) is used, the desired core member (12) is attached when the different diameter pipes are bent. At the time of replacement, the setting accompanying the adjustment of the bending position of the mandrel, and the troublesome work on replacement are caused.
Further, it will hinder productivity due to the consumption of time,
In addition, screwing (1
There was a problem that the 3) part was often loosened and became defective.

The present invention has been made in view of the above problems of the prior art, and the core member side can be immediately attached and detached by the mutual coupling being pressed by the release member in the axial direction. The desired setting and replacement can be performed easily and in a short time, which eliminates the hassle and enhances the productivity, and further, even in the case of bending for a long time, there is a fear that looseness will occur at these joints. It is an object of the present invention to provide a mandrel device or the like that can eliminate the above.

[0005]

In order to achieve the above object, the present invention has an annular groove formed in the groove of a support rod having a stepped small diameter portion and an annular groove formed in the small diameter portion. A cylindrical release member having a bottom is attached to the peripheral surface of the shaft core portion, in which a circular retaining ring having a pressure receiving surface is inserted and attached, and the rear end side serves as a pressing surface and abuts against the pressure receiving surface of the retaining ring. The stepped portion formed by the enlarged diameter portion is hooked on the retaining ring by incorporating the stepped portion formed by the enlarged diameter portion of the core member of the tip end having a short shape having a stepped enlarged diameter portion which is connected to the through hole and opens rearward. The gist is a mandrel device in which the enlarged diameter portion is supported by the small diameter portion so as to be detachably attached, and further, a projecting wall communicating with the enlarged diameter portion is provided at the bottom of the release member so as to project. The protruding wall portion is loosely attached to the through-hole portion of the core member, and the tip portion thereof is configured to slightly project outside the top portion of the core member. At least one slit is provided on the peripheral surface of the release member, the core member is composed of a tip member and a tubular member having separate through holes screwed with each other, and the projecting wall is further provided. The release member may be configured as a separate member that comes into contact with the bottom portion, or an opening may be provided in the bottom portion of the release member, and a through hole extending in the axial direction may be bored in the substantially central portion of the support rod, and if necessary, the A through hole extending in the axial direction is also provided in the central portion of the protruding wall.

[0006]

Since the present invention is constructed as described above, the shaft core of the release member is supported by the engagement with the retaining ring at the stepped portion formed by the expanded diameter portion on the core member side in which the release member is installed. By being configured to be detachably attached to the support rod by pressing in the direction, the setting and replacement can be performed by the above-mentioned hanging simply by direct pressing with the core member, and at the time of detachment, through the through hole portion. By pressing the bottom portion of the release member in the axial direction from the outside with a rod body or the like, the support of the holding ring is released by reducing the diameter of the holding ring. The core member can be easily set and exchanged each time, and it can be done in a very short time without any hassle, improving productivity, and in bending that is repeated for a long time. Well, mutual It becomes possible to eliminate the sorrow caused loose in the engaging portion.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a partially cutaway sectional view of a mandrel device of the present invention, and FIG. 2 is a perspective view of a release member of another embodiment. FIG. 3 is a perspective view of still another releasing member, FIGS. 4 to 6 are views corresponding to FIG. 1 of another embodiment, and FIG. 7 is a longitudinal sectional view of a protruding wall of another embodiment. Is a support rod, and a stepped small diameter portion (2) is provided on the tip side thereof, and an annular recessed groove (3) is provided in the small diameter portion,
A truncated circular retaining ring (4) having a taper-shaped pressure-receiving surface (4 ') consisting of a taper surface or a rounded surface facing forward and outward at the outer edge is inserted into the groove. The rear end is fixed to the bending device. (6) is a release member, the rear end of which is a taper.
It is a bottomed tubular shape that is in contact with the tapered pressure receiving surface (4 ′) of the retaining ring (4) as a tapered pressing surface (6 ′) having a curved surface or a round shape. The support rod (1) is provided with a through hole (5 ") attached to the tip of the support rod (1), and a stepped expanded portion (5 ') is formed in the rear of the through hole and opens rearward. The core member (5) at the tip of the short shape is internally mounted in the expanded diameter portion, and the stepped portion formed by the expanded diameter portion (5 ') is hung on the retaining ring (4) to support the small diameter portion ( It is configured to be detachably attached to 2).

In order to insert the release member (6) through the stepped small diameter portion (2) of the support rod (1), a plurality of slits are formed on the peripheral surface of the release member (6) as shown in FIG. (6 ") is provided,
As described above, by making the slit (6 ″) having a wide width into a circular cross section, the work of reducing the diameter of the release member (6) can be facilitated and the insertion can be facilitated.

Further, the core member (5) is provided with a through hole as shown in FIG.
If the tip member (5a) having (5 ") and the tubular member (5b) are divided so that the tip member (5a) and the tubular member (5b) can be screwed together, the release member (6 ) It is not necessary to give elasticity to itself, and it is possible to use a release member made of a rigid body.

Further, (7) is a projecting wall projecting from the bottom of the releasing member (6) as another embodiment (FIG. 5), and the expanding portion is
It is loosely attached to the through hole (5 ") of the core member (5) through the (5 ') by slightly protruding the tip of the core member to the outside from the top of the core member, and pressing the protruding tip when detaching. The hooks formed by the core member (5) on the retaining ring are released.

In the embodiment shown in FIG. 5, the projecting wall (7) is hollow by forming a through hole (7 ') extending in the axial direction, but it may be solid or may be formed by a releasing member (7). 6) and the protruding wall (7) may be integrally formed as shown in FIG. 5 or may be separately formed as shown in FIG. At this time, the separate protruding wall (7) can be made solid as shown in FIG.

The mandrel device according to the present invention can be used as a mandrel for extrusion molding of a thin resin tube, if desired, in addition to the use at the time of bending the pipe material, and in this case, the support rod (1 ) Is provided with a through hole (1 ') extending in the axial direction as shown in FIG. 6, and an opening (6a) is provided at the bottom of the release member (6) (FIGS. 2 and 3). Further, in the embodiment in which the protruding wall (7) is provided, a through hole (7 ') is also provided in the central portion of the protruding wall (7) to make it hollow (Fig. 7), so that the resin is removed from the inner wall surface of the thin resin tube. Gas emitted during tube molding is sucked to the outside through the through hole (7 '), opening (6a) and through hole (1'), and inert gas is passed through the through hole (1 ') and opening. (6a) and the through hole (7 ') can be filled in the resin tube.

[0013]

As described above, the mandrel device according to the present invention is detachable from each other by pressing the adhered core member (5) at the tip of the support rod (1) in the axial direction. Since they are joined together, the desired setting and replacement work when bending different diameter pipes can be performed easily and in a short time, which eliminates the hassle of work and enhances productivity. This is a very useful mandrel device because it is possible to eliminate the fear of loosening at the joints during repeated bending of time.

[Brief description of drawings]

FIG. 1 is a partially cutaway sectional view of a mandrel device showing an embodiment of the present invention.

FIG. 2 is a perspective view of a release member according to another embodiment.

FIG. 3 is a perspective view of a release member according to still another embodiment.

FIG. 4 is a view corresponding to FIG. 1 of another embodiment.

FIG. 5 is a view corresponding to FIG. 1 of still another embodiment.

FIG. 6 is a view corresponding to FIG. 1 of still another embodiment.

FIG. 7 is a vertical cross-sectional view of another embodiment of the protruding wall.

FIG. 8 is a partially cutaway sectional view of a conventional mandrel device.

[Explanation of symbols]

1 support rod 1'through hole 2 Small diameter part 3 annular groove 4'pressure receiving surface 4 retaining ring 5 core members 5a Tip member 5b tubular member 5'diameter 5 ″ through hole 6 Release member 6'Pressing surface 6 ″ slit 6a opening 7 protruding wall 7'through hole

Claims (7)

(57) [Claims] 1. The concave groove portion of a support rod (1) having a stepped small diameter portion (2) on the tip side and an annular concave groove (3) in the small diameter portion,
The holding ring (4) having an annular pressure receiving surface (4 ') is inserted, and the rear end side serves as a pressing surface (6').
Cylindrical release member (6) with a bottom that contacts the pressure receiving surface (4 ') of (4)
To the enlarged diameter portion of the core member (5) at the tip, which has a short dimension and has a stepped enlarged diameter portion (5 ') that opens rearward in continuation of the through hole (5 ") of the shaft core portion. Internally, the stepped portion formed by the expanded diameter portion (5 ') is hung on the retaining ring (4) to connect the expanded diameter portion to the small diameter portion (2).
A mandrel device, which is detachably attached to and configured on. 2. A diameter-expanded portion (5 ') is provided at the bottom of the release member (6).
A protruding wall (7) communicating with the core member (5).
2. The mandrel device according to claim 1, wherein the mandrel device is loosely attached to the through hole (5 ") of the core member and the tip of the core member is slightly projected from the top of the core member to the outside. 3. At least one peripheral surface of the release member (6)
Mandrel device according to claim 1 or 2, characterized in that it is provided with one slit (6 "). 4. The core member (5) is composed of a tip member (5a) having separate through holes (5 ") screwed together and a tubular member (5b). Any one of items 1 to 3
The mandrel device according to the item. 5. The mandrel device according to claim 2, wherein the projecting wall (7) is formed as a separate member that abuts the bottom portion of the release member (6). 6. An opening (6a) is provided at the bottom of the release member (6), and a through hole (1 ') extending in the axial direction is provided at substantially the center of the support rod (1). Claim 1 characterized by the above-mentioned.
The mandrel device described. 7. The mandrel device according to claim 6, further comprising a through hole (7 ') extending in the axial direction in the central portion of the protruding wall (7).