JP3457705B2 - Mandrel for bending hollow workpieces and bending equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bending mandrel used for bending a hollow metal work such as an aluminum hollow extrusion , a bending apparatus , and a bending method .

[0002]

2. Description of the Related Art For example, an aluminum seat frame material (S) as shown in FIG. 2A is a work (W) made of a flat aluminum hollow extruded material as shown in FIG. 2B. It is manufactured by applying a bending process to the above. For this bending process, for example, it is considered to use a multi-ventor type bending device.

This bending apparatus, as shown in FIG. 3, includes a fixed mold (51) having a work communication hole (51a),
A movable mold (52), which is arranged in front of the fixed mold (51), has a work conduction hole (52a) and is supported so as to be capable of turning and displacing, and the rear of the fixed mold (51). Placed in
Work (W) is fixed Work piece through hole (51a) of mold (51)
Work feeder (5
3) is provided, and the work feeder (53) cooperates with the forced conduction of the work (W) into the mold conduction holes (51a) (52a) and the turning / displacement operation of the movable mold (52). It is supposed that the work (W) is bent by the action.

In the case of bending the work (W) with the hollow material as described above, in order to suppress or prevent the occurrence of crushed deformation such as sink marks in the bent portion of the work (W), Generally, the mandrel (54) is used as one component of the bending apparatus.

Conventionally, as such a mandrel (54), a mandrel made of MC nylon material has been used, and the mandrel (54) is movable from inside the work conduction hole (51a) of the fixed mold (51). In a mode in which the mold (52) is protruded by a predetermined length, it is used by being appropriately arranged in the hollow portion of the work (W).

[0006]

However, the hollow work (W) is bent into the seat frame material (S) as described above by using the multi-bender incorporating the mandrel (54) having the conventional structure as described above. In this case, the radius of curvature r1 of the bent portions (b1) and (b1) of both the shoulders (s) and (s) of the seat frame material (S) is 60 mm, which is very severe, so that the mandrel (54) is It is difficult to follow such bending deformation in the hollow portion of the work (W). Therefore, in order to avoid the occurrence of damage to the mandrel (54), the tip of the mandrel (54) is placed between the fixed mold (51) and the movable mold (52) as shown in FIG. It was possible to project only up to the central part. As a result, the effect of the mandrel (54) is not always sufficiently exerted, and as shown in FIG. 4, the shoulder portion (s) of the obtained seat frame material (S) has a crushed shape such as a sink (a). There was a problem that the deformation of.

In view of the above-mentioned conventional problems, the present invention can cope with severe bending with a small radius of curvature, and effectively causes unintentional deformation such as sink marks at the bent portion of a bent product. It is an object of the present invention to provide a bending mandrel and a bending apparatus that can be suppressed or prevented from occurring.

[0008]

In the above object, according to the solution to ## this invention is to provide the following solutions.

[1] For bending metal hollow work
A bending mandrel which need, nylon press
Composed of exhibits and tensile strength (ASTM D-638) 7
20-840 kg / cm2, elongation (ASTMD-63
8) 20-100%, compressive strength (ASTMD-695)
800-950 kg / cm2, impact strength (ASTMD-
256, with Izod) 18-25kg · cm / 2.5
Bending process characterized by having a physical property of cm
Industrial mandrel.

[2] The nylon extruded product is water-added
It is an extruded product made from nylon 6 by the polymerization method.
The bending mandrel according to Item 1.

[3] The mandrel is a hollow work piece.
Has a cross-sectional shape size that fits within the section
The bending process according to claim 1 or 2, which is formed on the object.
Engineering mandrel.

[4] Fixed mold having a work conduction hole
And is placed in front of the fixed mold and the work is conducted.
Movable mold that has holes and is supported so that it can be turned or displaced.
And is placed behind the fixed mold, and the work is
A work feeder that forcibly conducts electricity to the work passage hole,
A state where the fixed die projects from the work hole to the movable die side.
And a mandrel arranged in the hollow part of the work,
Is equipped with the work feeder to the both mold conduction holes.
Cooperation between the forced conduction of the work and the turning / displacement operation of the movable mold.
Bending applied to bend the work by the action
In manufacturing equipment, the mandrel is a nylon extruded product.
And tensile strength (ASTM D-638) 720
~ 840kg / cm2, elongation (ASTMD-638) 2
0-100%, compressive strength (ASTMD-695) 800
~ 950 kg / cm2, impact strength (ASTM D-25
6, with Izod) 18-25kg · cm / 2.5cm
Hollow work characterized by having the following physical properties
Bending equipment.

[5] The tip of the mandrel is a movable metal.
It is designed to reach the inside of the work hole of the mold.
The apparatus for bending a hollow workpiece according to claim 4.

[6] The mandrel is used in a water addition polymerization method.
Nylon 6 is a nylon extruded product
The apparatus for bending a hollow work according to claim 4 or 5.

[7] The mandrel is a hollow part of the work.
With a cross-sectional shape size that fits within
The structure according to any one of claims 4 to 6 which is formed in
Bending device for mounted hollow workpieces.

[8] A fixed mold having a work conduction hole,
It is placed in front of the fixed mold and has a work conduction hole.
A and a movable die which is deflected-displaceably supported, solid
It is placed behind the fixed mold and the work is a fixed mold work.
Work feeder that forcibly conducts electricity to the conduction hole and fixed metal
In a mode in which it projects toward the movable mold side from inside the work conduction hole of the mold.
A mandrel disposed within the work hollow section have, is provided
Was bent using the processing device, both by the workpiece feeder
Forced conduction of the work into the die conduction hole and turning of the movable die
Hollow wire that bends the work by the cooperation with the displacement operation
In the method of bending the slab, the mandrel is
Ron extruded product and tensile strength (ASTM D-6
38) 720-840 kg / cm2, elongation (ASTMD
-638) 20 to 100%, compressive strength (ASTMD-6
95) 800 to 950 kg / cm2, impact strength (AST
MD-256, with Izod) 18-25kg · cm /
Characterized by using a material having physical properties of 2.5 cm
Method for bending hollow work.

[9] The mandrel is fixed to the fixed mold.
From the work conduction hole, protrudes in front of the fixed die, further
At the center position in the work hole of the movable mold.
Request to bend the work by arranging so as to reach
Item 9. A method for bending a hollow work according to Item 8.

[10] The mandrel is in the work.
Has a cross-sectional shape size that is placed in conformity within the void
The hollow work according to claim 8 or 9, wherein a hollow work is used.
Bending method.

As the above-mentioned nylon extruded product, an extruded product prepared from water-polymerized nylon 6 as a raw material is preferably used. As such a nylon extruded product, PN
A nylon material (Nippon Polyenco Co., Ltd.) is preferably mentioned as a specific example. The physical properties are shown in Table 1.

[0020]

[Table 1]

[0021]

In this invention, since the mandrel is made of a nylon extruded product, the mandrel is excellent in both tensile strength and elongation. Therefore, such a mandrel is placed in the hollow portion of the work. Even if the hollow work is placed and subjected to severe bending with a small radius of curvature, the mandrel can be deformed to follow such severe bending without damage, and the hollow work is suppressed from undesired deformation such as sink marks. Or is bent into a bent product having a bent portion with a small radius of curvature which does not exist.

Further, according to the present invention, since the mandrel is incorporated in the multi-bender type bending apparatus, the mandrel is largely protruded from the work communicating hole of the fixed mold to the movable mold side. However, the mandrel can follow and deform such bending in a region that undergoes severe bending between the fixed mold and the movable mold without being damaged. Therefore, the mandrel can be widely arranged in the hollow part of the work even in the region where the work is subjected to severe bending, and the work is prevented from undesired deformation such as sink marks, or the work has a bent part having a small radius of curvature. Bent to.

Further, according to the present invention, since the tip of the mandrel protruding from the work-passing hole of the fixed mold reaches the inside of the work-passing hole of the movable mold, the work is severely bent. The mandrel is supported from within the hollow portion over the entire length or substantially the entire length of the receiving length range, so that it is bent into a bent product having a bent portion with a small radius of curvature without unintentional deformation such as sink marks. Of course, since the mandrel is an extruded nylon product, the mandrel will not be damaged during such severe bending.

[0024]

Embodiments of the present invention will be described below.

In this embodiment, a hollow work (W) having a cross section as shown in FIG.
A seat frame material (S) as shown in (a) is manufactured.

The hollow work (W) is a hollow extruded material made of aluminum and having a square shape, and has a width B of 45 m.
m, height H is 13 mm, wall thickness t1 on the long side is 1.1 m
m, and the wall thickness t2 on the short side is 2 mm.

The seat frame material (S) is formed into an inverted U shape by bending the hollow work (W) in its height direction, and the lengths of both foot portions (l) (l) of the seat frame material (S) are formed. The intermediate part in the direction is a part manufactured by bending the work width direction. The radius of curvature r1 of the curved portion (b1) in the shoulder portion (s) is 60 mm, and the curved portion (b) in the foot portion (l) is (b).
2) The radius of curvature r2 of (b3) is 200 mm.

As shown in FIGS. 1 (a) and 1 (b), the apparatus used for the above-mentioned bending work is a fixed mold (1) having a work-passing hole (1a), and the fixed mold (1). It is arranged in front of 1) and has a work conduction hole (2a),
In addition, the work (W) is arranged behind the movable mold (2) which is supported so as to be able to turn and displace, and the fixed mold (1), and the work (W) is forced into the work communication hole (1a) of the fixed mold (1). A work feeder (3) for electrical continuity and a mandrel (4) are provided. Then, the work feeder (3) forcibly conducts the work (W) to both mold conduction holes (1a) (2a),
The work (W) is bent by the cooperation of the turning and displacement operations of the movable mold (2).

The fixed mold (1) holds the bending fulcrum mold (5) on the front side, the work guide mold (6) on the rear side, and both molds (5) (6). A holding die (7) is provided, and these work passage holes (5a) (6a) are used as work passage holes (1a) of the fixed die (1).
Is formed so as to conform to the outer peripheral shape of the.

Further, the movable mold (2) has a work conduction hole (2a) having an inner peripheral shape conforming to the outer peripheral shape of the work (W) at the center position in the front-rear direction, and from the center position in the front-rear direction. It is formed in a curved surface that opens in a curved surface toward the curved surface so that the workpiece (W) can smoothly pass through the conduction hole (2a) while being bent and displaced in a predetermined manner when the movable mold (2) is turned or displaced. Has been

Further, the feeder (3) is composed of a pusher (3a) which is forcibly moved in the front-back direction.

The mandrel (4) is made of a nylon extruded product, for example, an extruded product made from nylon 6 by a water-addition polymerization method, and is transversely arranged in the hollow portion of the work (W) in a conforming state. It is molded to have a surface shape size. The mandrel (4) has its rear end connected to and supported by the support bar (9), and protrudes from the inside of the work hole (1a) of the fixed mold (1) to the front of the fixed mold (1). Further, it is arranged so that the tip portion thereof reaches the center position in the work conduction hole (2a) of the movable mold (2).

In the bending process by the bending device, the work (W) is placed in the hollow portion of the mandrel (4).
1) (b), the pusher (3a) with
Is driven forward to force the work (W) into the work communication hole (1a) of the fixed mold (1), and the movable mold (2) is turned and displaced in a predetermined manner. Then, the work (W) is bent to have a predetermined bending shape while moving forward while being applied with a bending force with the movable mold (2) as an action point and the fixed mold (1) as a fulcrum.

During the bending process, in the region between the fixed mold (1) and the movable mold (2) where the bending action is exerted most strongly on the work (W), the work hollow part is filled in the hollow region of the work over the entire length of the region. Since the mandrel (4) is present in the shoulder, the shoulder (s) having a small radius of curvature and the intermediate portion of the foot (l) that is bent in the width direction are deformed by sinking due to bending. Without bending, it is bent into a bent product having bent portions (b1) (b2) (b3) having substantially the same cross-sectional shape as the straight portion. Moreover, by adopting the mandrel (4) made of a nylon extruded product, the mandrel (4) can follow such a severe bending without any trouble and elastically deformed, and the mandrel (4) is not damaged.

Incidentally, the hollow work (W) made of the A6061-T4 hollow extruded material having the size and shape shown in FIG. 2B is replaced with the seat frame material (S) having the size and shape as shown in FIG. 2A. MC nylon # 901 material (elongation: 10-50%, tensile strength: 80)
0-980kg / cm2) mandrel and MC nylon # 908 material (elongation: 40-150%, tensile strength:
520 to 650 kg / cm @ 2) mandrel and PN nylon material as an extruded product made from nylon 6 by the water addition polymerization method (elongation: 20 to 100%, tensile strength:
720 to 840 kg / cm2) and a mandrel with a mandrel, and the mandrel tip is projected to the center of the work conduction hole (2a) of the movable mold (2). Was bent by. In the multi-bender, the length L1 of the movable mold (2) in the front-rear direction is 40 mm,
Distance L2 between the fixed mold (1) and the movable mold (2)
Is 15 mm, and the protruding length L3 of the mandrel (4) from the fixed mold (1) is 35 mm.

As a result, in the mandrel made of MC Nylon # 901 material, dents occur when bending the bent portions (b2) and (b3) in the middle part of the foot (l) of the seat frame material (S), and the MC nylon material With the mandrel of # 908 material, the work (W) buckled and the mandrel was damaged at the first run. On the other hand, the mandrel made of the PN nylon material was stably bent into a seat frame material (S) having good bending shape and appearance quality as well as no damage to the mandrel.

The embodiment of the present invention has been described above.
The mandrel may have a structure in which notches extending in the circumferential direction are formed on the circumferential side surface at intervals in the length direction to improve the bending performance.

[0038]

As described above, since the bending mandrel of the present invention is made of the extruded product made of nylon, the mandrel is excellent in both tensile strength and elongation. Even if such a mandrel is placed in the hollow part of the work and the hollow work is subjected to severe bending with a small radius of curvature, the mandrel can be deformed following such severe bending without damage or the like. Undesired deformation such as is suppressed, or it can be bent into a bent product having a bent portion with a small radius of curvature that does not exist.

Further, the bending apparatus according to the present invention and
The bending method is such that the mandrel made of such nylon extruded product is incorporated in the multi-bender type bending apparatus, so that the mandrel is moved from the work hole of the fixed mold to the movable mold side. Even if the mandrel is largely projected, the mandrel can be deformed to follow such bending without breakage in the region where the fixed mold and the movable mold are subjected to severe bending, and thus the mandrel can be subjected to severe bending. In the above, the mandrel can be widely arranged in the hollow portion of the work, and the work can be bent into a bent product having a bent portion with a small radius of curvature in which an undesired deformation such as a sink is suppressed.

Further, the bending apparatus according to the present invention and
The bending method is such that the tip of the mandrel protruding from the work conduction hole of the fixed die reaches the inside of the work conduction hole of the movable die, so that the work has a length range subject to severe bending. The mandrel is supported from the inside of the hollow portion over the entire length or substantially the entire length thereof, so that the work can be bent into a bent product having a bent portion with a small radius of curvature without any undesired deformation such as sink marks. Of course, since the mandrel is made of an extruded product made of nylon, it is possible to perform bending without damaging the mandrel in such severe bending.

[Brief description of drawings]

FIG. 1A is a sectional view showing a bending apparatus according to an embodiment, and FIG. 1B is a sectional view of the bending apparatus during bending.

FIG. 2A is a perspective view of a seat frame member, and FIG. 2B is a cross-sectional view of a work.

FIG. 3A is a sectional view showing a bending apparatus according to a conventional example, and FIG. 3B is a sectional view of the bending apparatus on the way of bending.

FIG. 4 is a partial front view showing a sink mark at a shoulder portion of a seat frame member bent by a conventional bending device.

[Explanation of symbols]

1 ... Fixed mold 1a ... Work conduction hole 2 ... Movable mold 2a ... Work conduction hole 3 ... feeder 4 ... Mandrel W ... work S: Seat frame material

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Claims (10)

(57) [Claims] 1. Used for bending a metal hollow work.
A bending mandrel that, Ri Do from nylon extrudate, and a tensile strength (ASTMD
-638) 720-840 kg / cm2, elongation (AST
MD-638) 20-100%, compressive strength (ASTMD
-695) 800 to 950 kg / cm2, impact strength (A
STMD-256, with Izod) 18-25kg / c
machining mandrel bending, characterized in der Rukoto having the physical properties of the m / 2.5 cm. 2. The nylon extruded product is a water-added polymerization method.
An extruded product using nylon 6 as a raw material according to claim 1.
Bending mandrel described. 3. The mandrel is provided in a hollow portion of a work.
To have a cross-sectional shape size that is arranged in a conforming state
The bending man according to claim 1 or 2, which is formed.
Drel. 4. A fixed mold having a work communication hole, a movable mold arranged in front of the fixed mold, having a work communication hole, and supported so as to be capable of turning and displacing, a fixed mold. A work feeder, which is arranged at the rear of the mold and forcibly conducts the work to the work conduction hole of the fixed mold, and a work feeder which is arranged in the work hollow portion so as to project from the work conduction hole of the fixed mold to the movable mold side. In a bending apparatus equipped with a mandrel, the work feeder bends the work by the cooperative action of the work feeder forcibly introducing the work into both mold conduction holes and the turning / displacement operation of the movable mold. the mandrel, Ri Do from nylon extrudate, and pull
Tensile strength (ASTM D-638) 720-840kg / c
m2, elongation (ASTMD-638) 20-100%, pressure
Compressive strength (ASTM D-695) 800-950 kg / c
m2, impact strength (ASTM D-256, with Izod)
Those with physical properties of 18-25 kg · cm / 2.5 cm
Bending apparatus of the hollow workpiece, characterized in der Rukoto. 5. The hollow work bending apparatus according to claim 4 , wherein the tip of the mandrel reaches the inside of the work communication hole of the movable mold. 6. The mandrel is produced by a water addition polymerization method.
A nylon extruded product made from nylon 6 as a raw material.
The apparatus for bending a hollow work according to 4 or 5. 7. The mandrel is provided in a hollow portion of a work.
To have a cross-sectional shape size that is arranged in a conforming state
Formed according to any one of claims 4 to 6.
Bending machine for hollow workpieces. 8. A fixed die having a work passage hole, a movable die arranged in front of the fixed die, having a work passage hole, and supported so as to be capable of turning and displacing, a fixed die. A work feeder, which is arranged at the rear of the mold and forcibly conducts the work to the work conduction hole of the fixed mold, and a work feeder which is arranged in the work hollow portion so as to project from the work conduction hole of the fixed mold to the movable mold side. Using a bending machine equipped with a mandrel, a hollow workpiece that bends the work by the cooperative action of the work feeder's forced conduction of the work into both mold conduction holes and the turning / displacement movement of the movable mold. Bending method smell
The extruded nylon product and
Tensile strength (ASTM D-638) 720-840kg / c
m2, elongation (ASTMD-638) 20-100%, pressure
Compressive strength (ASTM D-695) 800-950 kg / c
m2, impact strength (ASTM D-256, with Izod)
Those with physical properties of 18-25 kg · cm / 2.5 cm
A method for bending a hollow work, the method comprising: 9. The mandrel is attached to a work piece of the fixed mold.
From the inside of the conduction hole to the front of the fixed mold, and
The tip of the to the central position in the work hole of the movable die
Arranged so as to reach and bend the workpiece.
Hollow word over click bending method according. 10. The mandrel is in a hollow portion of a work.
Having a cross-sectional shape size that is arranged in conformity with
Bending of a hollow workpiece according to claim 8 or 9,
Construction method.