JP2003191009A - Extrusion die for perforated tube - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an extrusion die for a perforated tube with excellent productivity which is easily adapted to precise machining, and reduces the maintenance cost. <P>SOLUTION: This extrusion die comprises a male die 2 which has a bridge part 4b along the radial direction of a ring part 4a and forms hole parts in a perforated tube T and a female part 3 which is combined therewith to form an outer circumferential part of the perforated tube T. A needle-shaped mandrel piece 5 is inserted in and fixed to each holding hole 8 of a plurality of mandrel piece holding holes 8 which are formed in the longitudinal direction of the bridge part 4b and penetrated in the extruding direction so that each tip part is protruded from the bridge part 4b. A male bearing part 9a to form each hole part T1 of the perforated tube T is swollen on a tip part of each mandrel piece 5. The surface of a male bearing part 9a is formed flat and smooth. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an extrusion die for producing a flat porous tube material made of aluminum or its alloy such as used as a heat exchange tube of a heat exchanger.

[0002]

2. Description of the Related Art For example, as a method for manufacturing a flat porous tube material (100) for a heat exchanger as shown in FIG. 12, an extrusion die having a molding gap corresponding to the cross-sectional shape of the tube material (100) is used. There is an extrusion method in which an extrusion material such as aluminum is molded into this die. The die (101) used in this extrusion method includes, as shown in FIG. 11, a female die (103) having an extrusion hole (104) for molding the outer peripheral portion of the tube material (100), and a tube material (10).
A male mold (102) having a mandrel (106) in which a plurality of hole forming parts (105) (105) for forming the hole parts (100a) (100a) of (0) are provided in a comb tooth shape. , Each hole forming part (10
5) (105)… Male bearing part (105
The male mold (102) and the female mold (103) are combined in a state in which a) (105a) are opposed to each other in the extrusion hole (104). By combining in this way, a molding gap (110) having a shape corresponding to the cross-sectional shape of the porous tube material (100).
Is formed, and the extruded material passes through the molding gap (110), whereby the porous flat tube material (100) is molded.

[0003]

By the way, since the hole forming part (105) of the mandrel (106) is required to have a hardness that can withstand a high extrusion pressure at the time of forming, as a constituent material thereof, Cemented carbide or cemented carbide is used, and the hole forming part (105) is usually formed by an electric discharge machining method or the like.

However, the hole forming part (105) is
It is processed at the tip of the mandrel (106). For example, if you want to increase the hollow density by increasing the number of holes (100a) in the porous tube material (100), make the hole forming part (105) extremely fine. Although it has to be machined, there is a limit to the precision machining of the male bearing part (105a) which is the tip of the hole forming part (105). That is, when the hollow density of the porous tube material (100) is increased, the gap between the hole forming parts (105) (105) becomes narrower, and the facing surfaces of the adjacent hole forming parts (105) (105) are polished. It is not possible to finish on a smooth surface due to factors such as As described above, when the surface of the hole forming part (105), especially the male bearing part (105a) at the tip of the hole forming part is rough, the resistance against extrusion becomes high, which not only causes damage to the hole forming part (105). However, there has been a problem that the extrusion speed becomes slow and it is difficult to efficiently produce the porous tube material (100).

Further, in the conventional extrusion die (101),
Since the hole forming part (105) of the mandrel (106) is integrally formed at the tip of the mandrel (106), the entire mandrel (106) is made of expensive cemented carbide material, resulting in high component cost. Tsuku.

Further, the mandrel (106) has a hole forming part (1
Since 05) is integrally formed, if the hole forming part (105) is damaged, the entire mandrel (106) must be replaced, and repair and maintenance costs increase.

The present invention has been made in view of the above-mentioned problems of the prior art, and is capable of easily responding to fine processing, reducing the maintenance cost, and excellent in the production efficiency of the porous tube material for extrusion. The purpose is to provide dice.

[0008]

In order to achieve the above object, an extrusion die for a perforated tube material according to a first aspect of the present invention has a bridge portion along the radial direction of a ring portion to form a hole portion of the perforated tube material. A male die and a female die that is combined with the male die to mold the outer peripheral portion of the porous tube material, and holds each of a plurality of mandrel piece holding holes that are arranged in the longitudinal direction of the bridge portion and penetrate in the extrusion direction. A needle-shaped mandrel piece is inserted and fixed in the hole in a state where the tip portion is projected from the bridge portion, and a male bearing portion for molding each hole portion of the porous tube material is provided at the tip portion of each mandrel piece. The male bearing portion is formed so as to bulge, and the surface of the male bearing portion is formed to be smooth.

In the extrusion die according to the first aspect of the present invention, a needle-shaped mandrel piece is inserted and fixed in each of a plurality of mandrel piece holding holes formed in the bridge portion. At the tip of each mandrel piece, a male bearing part that forms each hole of the porous tube material is bulged and formed, and since these mandrel pieces are formed as independent members, respectively, there is no gap between the male bearing parts. Regardless of the above, it is possible to obtain a fine male bearing portion whose cross-sectional shape and size are arbitrarily set. In addition, the surface of the male bearing portion can be formed into a smooth surface by polishing or the like, and the resistance against extrusion can be suppressed as much as possible by forming in this way. For this reason, even when the number of holes in the porous tube material is increased to increase the hollow density, it is possible to minimize damage to the male bearing portion and to extrude at a relatively high speed. It is possible to improve efficiency. Also, since a separate mandrel piece is inserted and fixed in the mandrel piece holding hole, use expensive cemented carbide material for the mandrel piece and use inexpensive steel material such as die steel for the other male member. Since it is good, the component cost can be reduced. Further, when the mandrel piece is damaged, only the mandrel piece needs to be replaced, so that repair and maintenance costs can be reduced.

In the first aspect of the present invention, the mandrel piece holding holes are formed such that the holding holes adjacent to each other are communicated with each other through a narrow communication hole penetrating in the extruding direction at a middle portion in the height direction. preferable. With this configuration,
The mandrel piece is firmly fixed to the bridge. That is, since the bridge portion is easily elastically deformed by the narrow communication hole, the bridge portion presses the mandrel piece more firmly by the pushing pressure, and the mandrel piece is surely prevented from being pulled out in the pushing direction.

Further, in the first invention, it is preferable that the mandrel piece is provided with a means for preventing the mandrel piece from being pulled out in the extrusion direction at the rear end portion. According to this structure, the removal of the mandrel piece in the extrusion direction can be prevented more reliably.

The extrusion die for perforated tube material according to the second aspect of the present invention comprises a male die having a bridge portion along the radial direction of the ring portion for forming the hole portion of the perforated tube material, and a perforated tube combined with the male die. A mandrel unit holding hole formed by penetrating in the bridge portion in the extrusion direction, the mandrel unit is inserted and fixed, and the mandrel unit is superposed in the extrusion direction. A pair of sandwiching plates having a plurality of mandrel piece holding holes along it, and needle-shaped mandrel pieces which are separate from each other and arranged in the respective holding holes, are provided at the tip of each mandrel piece. Is formed by bulging the male bearing part that molds each hole of the porous tube material,
The surface of the male bearing portion is formed into a smooth surface, while the mandrel piece is sandwiched between the pair of sandwiching plates with each of the distal end portions protruding from the distal end surface of the sandwiching plate. It is characterized by

The extrusion die according to the second aspect of the present invention is different from the extrusion die according to the first aspect of the present invention.
The mandrel piece is not directly attached to the bridge portion, but is sandwiched by a pair of sandwiching plates to form a mandrel unit, and is attached by inserting the mandrel unit into a mandrel unit holding hole formed in the bridge portion. . Therefore, according to the second aspect of the invention, the extrusion die can be manufactured relatively easily. That is, in this extrusion die, a relatively large mandrel unit holding hole is formed in the bridge portion, while a mandrel piece holding hole that requires delicate work is formed on at least one opposing surface of a pair of sandwiching plates with a groove. Can be performed relatively easily by forming
It can be easily manufactured as compared with the extrusion die of the invention. Therefore, a highly accurate extrusion die can be manufactured. Further, for the same reason as in the above first invention,
A fine male bearing part can be formed, damage to the male bearing part can be minimized, and it can be extruded at a relatively high speed to improve production efficiency. Can be reduced, and the repair and maintenance costs can be reduced.

In the second aspect of the present invention, it is preferable that the mandrel piece holding holes are formed such that the holding holes adjacent to each other are communicated with each other through a narrow communication hole penetrating in the extrusion direction at an intermediate portion in the height direction. According to this structure, similarly to the case of the first aspect of the invention, the bridge portion firmly presses the mandrel piece by the extrusion pressure, and the removal of the mandrel piece in the extrusion direction is reliably prevented.

In the second aspect of the invention, it is preferable that the mandrel piece is provided with a means for preventing the mandrel piece from being pulled out in the extrusion direction at its rear end. With this configuration,
As in the case of the first aspect of the invention described above, the removal of the mandrel piece in the extrusion direction is prevented more reliably.

Further, in the second aspect of the present invention, the sandwiching plate is provided with a bulging portion at one end in the width direction and a fitting recess at the other end in the width direction, so that a pair of sandwiching members are sandwiched. It is preferable that the plates are overlapped with each other by fitting their bulges into the other fitting recesses. According to this structure, the pair of sandwiching plates can be configured by the sandwiching plates having the same shape, and the manufacturing cost can be reduced. Further, the pair of sandwiching plates can be accurately positioned and overlapped with each other, whereby the mandrel piece can be securely sandwiched.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Extruding dies for porous tube materials according to the first and second inventions will be described based on the embodiments shown in the drawings.

The extrusion die for perforated tube material according to the embodiments described below is used for molding the flat aluminum perforated tube material (T) used in a heat exchanger as shown in FIG. The extrusion dies (1) (51) for the porous tube material of the first and second inventions are
It goes without saying that it is widely applied to extrusion of various porous tube materials in addition to the tube material for heat exchangers. Further, the material of the porous tube material is not limited to aluminum or its alloy, and other various metals suitable for extrusion molding may be used.

<< One Embodiment of the First Invention >> This First Embodiment
An extrusion die (1) according to one embodiment of the invention (hereinafter, referred to as “first embodiment”) is a male die for molding a hole portion of a porous tube material (T) as shown in FIGS. 1 to 3. (2) and a female die (3), which is combined with the male die (2) and forms the outer peripheral portion of the porous tube material (T), serve as main constituent members.

As shown in FIGS. 1 to 3, the male mold (2) comprises an annular base body (4), a plurality of mandrel pieces (5) (5) ..., And a lid member (6).

As clearly shown in FIG. 1, the annular base body (4) is a cylindrical mold member made of a steel material such as die steel, and extends in the radial direction from the inner rear end edge to the front end edge of the ring portion (4a). A bridge portion (4b) is formed integrally therewith, and voids on both sides sandwiching the bridge portion (4b) are formed as material conduction holes (4c).

The bridge portion (4b) has a structure shown in FIGS.
As is clearly shown in FIG. 3, a lid accommodating groove (7) is formed along the longitudinal direction of the rear end face in the extruding direction, and a mandrel piece holding hole penetrating in the extruding direction is formed at the bottom of the lid accommodating groove (7). A plurality of (8), (8) ... Are arranged along the longitudinal direction of the lid accommodating groove (7) which is the longitudinal direction of the bridge portion (4b). The cross-sectional shape of the mandrel piece holding hole (8) is appropriately set according to the cross section of the mandrel piece (5), but in the first embodiment, the mandrel piece is formed into a rectangular cross section as shown in FIG. The piece (5) can be press-fitted and held in a substantially fitted state. These mandrel piece holding holes (8) have narrow communication holes (8a) (8a) at the intermediate portions in the direction in which the holding holes (8) (8) adjacent to each other are orthogonal to the height direction, that is, the width direction. Are communicated via. Like the holding hole (8), the narrow communication hole (8a) is provided so as to penetrate in the extrusion direction,
Adjacent holding holes (8) (8) are communicated with each other over their entire length. Further, the holding holes (8) and (8) adjacent to the rear end opening side of the mandrel piece holding hole (8) in the height direction are adjacent to the engaging step portions (8b) and (8b) retracted outward in the height direction. It is formed so as to straddle the gap. These engagement step portions (8b) (8b) are engagement projections for preventing the mandrel piece (5) from being pulled out, which will be described later, in a state where the mandrel piece (5) is press-fitted into the mandrel piece holding hole (8). The parts (5a) and (5a) can be engaged with each other.

The tip of the bridge portion (4b) is shown in FIG.
As shown in (a) and FIG. 3 (a), the extruded material is formed so that it is formed so as to slightly project from the tip end surface of the ring portion (4a), and the longitudinal middle portion thereof is tapered. It is supposed to flow. Further, the annular base body (4) is formed such that the peripheral edge portion of the tip end face in the extrusion direction is cut out over the entire circumference, whereby the tip end portion is formed as a fitting convex step portion (4d), and this fitting is performed. Knock pin through holes (4e) (4e) are formed at symmetrical positions on the peripheral edge of the tip surface of the convex step (4d).

The mandrel piece (5) is cut out from a cemented carbide plate made of cemented carbide, ceramics or the like with a diamond grindstone having a fine roughness. Therefore, the cut surface is polished to form a mirror-like smooth surface. Has been done. As shown in FIGS. 1 to 4, the mandrel piece (5) has a needle shape having a rectangular cross section, that is, an elongated shape. Further, as clearly shown in FIG. 2C, the mandrel piece (5) is provided with engaging projections (5a) (5a) with its rear end protruding in both height directions, and the mandrel piece (5) is provided as described above. The piece holding hole (8) can be engaged with the engaging stepped portion (8b). The mandrel piece (5) is shown in FIGS.
As shown in Fig. 7, when the engaging protrusions (5a) (5a) are engaged with the engaging stepped portions (8b) (8b) of the mandrel piece holding hole (8), the tip portions thereof are bridge portions ( 4b) is press-fitted and held in the mandrel piece holding hole (8) in a state of protruding by a predetermined length from the tip surface of 4b), and each protruding tip portion is configured as a hole forming portion (9). The hole forming part (9) is
As clearly shown in FIGS. 2 (b) and 3 (b), the base end portion has a tapered portion (9b) whose cross-sectional area decreases toward the tip, while the tip end portion thereof has a porous tube material (T). Male bearing part (9a) that molds each hole (T1) of
Are formed to bulge outward. The cross-sectional shape and size of the male bearing portion (9a) are appropriately determined according to the cross-sectional shape and size of each hole (T1) of the porous tube material (T) to be manufactured, but the mandrel piece (5). Is preferably determined in consideration of the sectional shape and opening area of the holding hole (8) so that the mandrel piece holding hole (8) can be inserted from the rear end side. In the first embodiment, in the two mandrel pieces (5) and (5) arranged at both longitudinal ends of the bridge portion (4b), the mandrel pieces (5) and (5) are directed outward in the width direction.
On the other hand, the mandrel pieces (5), (5), etc., which are formed in a V-shaped cross section, are formed in a substantially rectangular cross section elongated in the height direction, and these male bearing portions (9
The size of a) is the corresponding holding hole (8) (8)
It is formed corresponding to the opening area of. The taper portion (9b) and the male bearing portion (9a) are processed with a diamond grindstone, and the processed surface is formed into a mirror-like smooth surface. That is, the hole forming part (9)
The surface of (9) ..., in particular, the surface of the male bearing portion (9a) is polished to a mirror-like smooth surface to reduce the resistance to extrusion.

The number of mandrel piece holding holes (8) and the number of mandrel pieces (5) are not particularly limited, and are appropriately determined depending on the number of holes of the porous tube material (T) to be manufactured.

As described above, the mandrel piece (5) according to the first embodiment is formed as a member independent from each other, and the male bearing for forming each hole (T1) of the porous tube material (T) is formed in each. Since the section (9a) is provided,
The mandrel pieces (5) are individually processed to form a fine male bearing part (9
a) (9a) ... can be formed. Therefore, even when the mandrel pieces (5) (5) ... Are attached to the bridge portion (4b) and the gap between the male bearing portions (9a) (9a) is extremely narrow, the individual mandrel pieces (5 ) (5) ... The hole forming parts (9) (9) ...
In particular, by polishing the surfaces of the male bearing portions (9a) (9a) ..., a smooth surface can be obtained over the entire surface, and the resistance to extrusion can be reduced as described above.

The lid member (6) prevents the extruded material from entering the mandrel piece holding holes (8) (8) ... And the narrow communication holes (8a) (8a). It is formed of a hard material in the shape of a slender plate, and the bridge part (4
It is designed to be fitted tightly into the lid accommodating groove (7) of b).

The male mold (2) is assembled as follows. First, the mandrel pieces (5) (5) ... Are attached to the annular base body (4). That is, as shown in FIG. 5, the rear end side opening and the cross-sectional shape of the mandrel piece (5) correspond to the mandrel piece holding holes (8) (8) of the bridge portion (4b) of the annular base body (4). Then, the mandrel pieces (5) are attached to the bridge part (4
Integrate pressure contact with b). In this inserted state,
The engaging protrusions (5a) (5a) of the mandrel piece (5) are engaged with the engaging stepped portions (8b) (8b) of the annular base body (4), and the mandrel piece (5) is removed in the extrusion direction. Certainly prevented. That is, the engaging protrusions (5a) (5a) and the engaging step (8b)
(8b) constitutes the pull-out prevention means referred to in the first aspect of the invention. And
The lid member (6) is tightly fitted in the lid housing groove (7) of the bridge portion (4b) to assemble the male mold (2).

The female mold (3) is shown in FIG. 1, FIG.
As shown in (a), it is provided with an annular peripheral wall member (10), a flow guide plate (11), a female mold body (12), and a backup mold (13).

The annular peripheral wall member (10) includes a flow guide plate (11), a female mold body (12) and a backup mold (13).
Is to accommodate. The annular peripheral wall member (10) is made of die steel, and has an accommodating hole (10a) formed in the axial center thereof so as to penetrate therethrough in the extrusion direction, as clearly shown in FIG. A key groove (10b) is formed at a radially symmetrical position on the inner circumference of the accommodation hole (10a) to relatively rotate the flow guide plate (11), the female mold body (12) and the backup mold (13). It is supposed to be able to be housed in a concentric manner. Further, on the rear end surface of the annular peripheral wall member (10), a fitting concave portion (10) corresponding to the fitting convex portion (4d) of the annular base body (4) is formed.
c) is formed, and knock pin through holes (10d) (10d) are similarly formed in the fitting recess (10c) at positions facing the knock pin through holes (4e) (4e) of the annular base body (4).
Are formed.

The flow guide plate (11) is for adjusting the flow of the extruded material, and as shown clearly in FIG.
It is made of a hard material such as die steel and has a substantially disc shape. The flow guide plate (11) has a female main body (1
Communication hole (11a) corresponding to the extrusion hole (12a) described later in 2)
Are provided so as to penetrate therethrough. The shape of the communication hole (11a) is not particularly limited and is appropriately determined in consideration of the flow of the extruded material, but in the present embodiment, a rectangular shape along the radial direction of the flow guide plate (11). Is formed in.
In addition, the inner peripheral surface at the rear end portion in the thickness direction of the guide plate (11) of the communication hole (11a) is formed in a tapered shape that widens toward the rear end side, as shown in FIG. , Which controls the flow of the extruded material. In addition, the engagement key (11b) (11b) is also provided on the outer periphery of the flow guide plate (11).
Is provided.

As shown in FIG. 1, the female mold body (12) is a substantially circular short column made of a cemented carbide material such as cemented carbide, and has a shaft member having an outer periphery of the tube material (T). A flat extrusion hole (12a) for molding the portion and a mold material outlet hole (12b) connected to the front edge of the extrusion hole (12a) in the extrusion direction are provided. The mold material lead-out hole (12b) is formed in a tapered shape that widens in the extrusion direction. Engagement keys (12c) (12c) are also provided on the outer peripheral portion of the female body (12).

The backup mold (13) is arranged adjacent to the front end of the female mold body (12) in the extrusion direction and supports the pressure acting on the female mold body (12) from the rear during extrusion. Is. As shown in FIG. 1, the backup mold (13) is a short column whose outer peripheral shape is the same as that of the female main body (12), and the axial center portion of which is the female main body (12). A mold material lead-out hole (13a) continuous with the mold material lead-out hole (12b) is formed. Engagement keys (13b) (13b) are also provided on the outer periphery of the backup mold (13).

The female mold (3) is assembled as follows. That is, by sequentially accommodating the backup mold (13), the female main body (12) and the flow guide plate (11) in the accommodating hole (10a) of the annular peripheral wall member (10) and performing shrink fitting. The annular peripheral wall member (10) is pressure-contacted and integrated with the backup mold (13), the female mold body (12) and the flow guide plate (11).

Then, the male and female dies (2) and (3) assembled as described above are combined with each other to assemble the extrusion die (1). That is, while fitting the fitting protrusion (4d) of the male mold (2) into the fitting recess (10c) of the female mold (3),
Each knock pin through hole (4e) (10) of both male and female types (2) (3)
Assemble the male and female molds (2) and (3) in a positioned state by inserting knock pins (15) and (15) into d).

In this combined state, the male bearing portions (9a) (9a) of the mandrel pieces (5) (5) ... Are arranged opposite to the extrusion holes (12a) of the female mold body (12). Corresponding to the cross-sectional shape of the tube material (T) between the male bearing portions (9a) (9a) of the mandrel pieces (5) (5) ... and the extrusion hole (12a) of the female body (12) A molding gap (20) is formed. Then, a molten metal of an extruding material such as aluminum is poured into the extruding die (1) to be incorporated in an extruder, and the extruding material is continuously pressed into the extruding die at a required introduction amount, whereby the extruding die ( 1)
Of the perforated flat tube material (T) is extruded in front of. As a result, the material extruded from the forming gap (20) forms the outer peripheral portion of the metal porous flat tube material (T), and also passes through the gap between the adjacent hole forming portions (9) (9). The same tube material (T) depending on the extruded material
The partition walls are formed, and the hole portions corresponding to the hole forming portions (9) (9) ... Are configured.

According to the extrusion die (1) of the first embodiment, as described above, the male bearing portion (9a) is used.
(9a) are finely formed, and the number of holes (T1) is increased, and the porous tube material (T) having an increased hollow density can be efficiently extruded. That is, the male bearing part (9
Since the surface of a) is formed as a smooth surface, resistance to extrusion can be suppressed as much as possible. Therefore, the male bearing portions (9a) (9a) ..., and by extension, the hole forming portions (9) (9).
The damage to the tube can be minimized and it can be extruded at a relatively high speed, and the porous tube material (T)
The production efficiency can be improved.

Also, the mandrel piece holding hole (8)
(8) ... Mandrel piece which is a separate body (5) (5) ...
Since an expensive cemented carbide material is used for the mandrel piece (5) and other members of the male die (2) such as the annular base body (4) are made of inexpensive steel material such as die steel because Since it is good, the component cost can be reduced. Further, if the mandrel piece (5) is damaged, only the mandrel piece (5) needs to be replaced, so that repair and maintenance costs can be reduced.

Further, since the bridge portion (4b) is easily elastically deformed by the narrow communication holes (8a) (8a) ...
The extruding pressure firmly fixes the mandrel pieces (5) (5) by the bridge portion (4b) to reliably prevent the mandrel piece from being pulled out in the extruding direction.

<< One Embodiment According to Second Invention >> Next, one embodiment of the second invention (hereinafter, referred to as "second embodiment").
The extrusion die (51) according to the present invention will be described with reference to FIGS. 6 to 9.

This extrusion die (51) is preferably used for a plurality of simultaneous extrusions. As shown in FIGS. 6 to 8, the mandrel pieces (55) (55) are paired with a sandwiching plate ( 71) Mandrel unit (72) that is sandwiched between (71)
And the mandrel unit (72) is attached to the bridge portion (54b), which is a big difference from the first embodiment.

That is, the male mold (52) includes an annular base (54), a mandrel unit (72), and a mandrel unit (72) as shown in FIG.
And a lid member (56).

The annular base body (54) is made of a hard material, and comprises an annular portion (54a) and a bridge portion (54b). The shaft hole of the annular part (54a) is
c), and is capable of accommodating therein a flow guide plate (11), a female mold body (12) and a backup mold (13) similar to those of the first embodiment.

The female fitting hole (54c) is provided with key grooves (54d) (54d) which are concentrically accommodated in the female mold (53) in a relatively non-rotatable manner at radially symmetrical positions. ing. An annular step (54e) is provided on the outer peripheral edge of the rear end surface of the annular portion (54a) in the extrusion direction, and the annular step (54e) is provided in the circumferential direction of the annular portion (54a). Four knock pin through holes (54f) (54f) ... Are formed therethrough.

The bridge portion (54b) of the annular base (54) is
As shown in FIG. 6 and FIG. 8 (a), in a mode in which the annular portion (54a) projects rearward from the rear end face in the extrusion direction, the female fitting hole portion (54c) of the annular portion (54a) is crossed. The bridging portion (54b) is formed so as to straddle and the leading edge portion of the bridging portion (54b) in the pushing direction substantially opposes the rear end surface of the annular portion (54a).

As shown in FIGS. 6 to 8, a lid accommodating groove (57) is formed along the longitudinal direction of the rear end face of the bridge portion (54b), and the mandrel unit is also extended along the longitudinal direction. In order to hold (72), a horizontally elongated slit-shaped mandrel unit holding hole (73) is formed so as to penetrate in the extrusion direction, and further, both sides in the height direction on the rear end opening side of the mandrel unit holding hole (73). Engagement stepped portions (73a) (73a) are formed on the inner surface and are recessed outward in the height direction.

As shown in FIG. 9, the mandrel unit (72) comprises a pair of sandwich plates (71) (71) and a plurality of needle-shaped mandrel pieces (55) (55).

The pair of sandwich plates (71) (71) are made of a hard material such as die steel and are formed in a rectangular plate shape. As shown in FIG. 9, a plurality of pin-holding grooves (71a) (71a) extending from the front end to the rear end are formed on the opposing surfaces of the pair of sandwich plates (71) (71). It is formed with a predetermined set interval in the direction. The groove lines (71a) (71a) ... In the second embodiment are the mandrel piece holding holes (8) (8) in the first embodiment when the pair of sandwiching plates (71) (71) are overlapped. ), The mandrel piece holding holes (58) (58) are formed along the extrusion direction, and adjacent holding holes (58) are formed.
(58) are communicated with each other through narrow communication holes (58a) (58a) ...

The groove (71a) does not necessarily have to be formed in both the sandwiching plates (71) (71). For example, grooves (71a) (71a) ... corresponding to the mandrel pieces (55) (55) ... are formed on one sandwich plate, and these grooves (71a) (71a) ... are formed with grooves. The other sandwiching plate which is not provided may be used for closing. Book second
In the embodiment, the U-shaped grooves (71a) (71a) ... Of the same cross-section are formed on the opposing surfaces of the pair of sandwich plates (71) (71).

In addition, on each opposing surface of the sandwiching plate (71), as shown in FIG.
As shown in FIG. 5, a ridge-shaped bulging portion (71b) is formed along one of the widthwise edges along the longitudinal direction from the leading edge to the trailing edge, and the other of the ridges is formed along the longitudinal direction. Fitting recess (71c) that fits into the bulging part (71b)
Is formed so that the pair of sandwiching plates (71) (71) can be superposed in a positioned state.

Further, as shown in FIG. 9, at a portion of the facing surface of these sandwiching plates (71) slightly closer to the rear end portion in the longitudinal direction, along the width direction of the sandwiching plates (71), An elongated key receiving groove (74) is provided in a manner to traverse all the groove lines (71a) (71a) ..., and the key receiving groove (74) has a prismatic shape that can be fitted to the key receiving groove (74). The removal prevention key (75) is housed. The key accommodating groove (74) is deeper than the groove strips (71a) (71a) ... While the key accommodating groove (74) accommodates the removal preventing key (75). In this state, the upper surface of the key (75) has grooves (71a) (71
It is set so as to be located between the bottom surface of a) ... and the facing surface of the sandwich plate (71). That is, the removal prevention key (75)
However, the grooves (71a) (71a) ... are accommodated and arranged in such a manner that the corresponding portions of the grooves (71a) (71a) ...

As shown in FIG. 9, the longitudinal rear ends of the pair of sandwiching plates (71) (71) on the opposite sides of the opposing faces are arranged in the width direction of the sandwiching plates (71). Key fitting grooves (76) (76) having a U-shaped cross section are formed along the entire width. The lower ends of the oblong prismatic engagement keys (77) (77) are fitted into the key fitting grooves (76) (76), while the upper ends of the engagement keys (77) (77) are engaged. Is an engaging step (73a) (7a) (7a) formed at the rear end of the mandrel unit holding hole (73).
3a) to prevent the mandrel unit (72) from being pulled out in the pushing direction.

On the other hand, mandrel pieces (55) (55) ...
Is different from the mandrel pieces (5) (5) of the first embodiment in the structure at the base end thereof. That is, at the base end of the mandrel piece (55), as shown in FIG.
Detachment prevention engagement grooves (55a) (55a) having a U-shaped cross section with which (5) (75) are engaged are formed in a state of traversing the mandrel piece (55). These mandrel pieces (55)
Of the mandrel pieces (55) (55) ... by engaging the withdrawal prevention keys (75) (75) with the withdrawal prevention engaging grooves (55a) (55a). It is supposed to prevent. Therefore, these removal preventing engagement grooves (55a) (55a)
And the withdrawal prevention keys (75) (75) form the withdrawal prevention means referred to in the second aspect of the present invention, and more reliably prevent the withdrawal of the mandrel pieces (5) (5) ... In the extrusion direction. Has been done. In the state where the mandrel pieces (55) (55) are sandwiched by the pair of sandwich plates (71) (71), the hole forming part (59) is formed from the tip surfaces of the pair of sandwich plates (71) (71). (59) ... is made to project.

The grooves (71a) (71a) provided on the opposing surfaces of the pair of sandwich plates (71) (71) are the sandwich plates (71).
Mandrel piece (5
It should be formed to a length that can hold 5).

Then, the mandrel unit (72) is assembled as follows. That is, as shown in FIG. 9, the pull-out prevention key (75) is housed in the key housing groove (74) of the one sandwiching plate (71), and the mandrel pieces (55) (55) are housed.
, And one of the engagement preventing grooves (55a) (55a) is fitted into the key (75), respectively.
Place them in the grooves (71a) (71a) of 1). Then, the other sandwiching plate (71) in which the removal preventing key (75) is also housed in the key housing groove (74) is provided with the ridge-shaped bulging part (71b) and the fitting recess (71c). The fitting concave portion (71c) of the sandwiching plate (71) and the ridge-shaped bulging portion (71b) are opposed to each other, and the removal preventing key (75) is provided on the other side of the mandrel pieces (55) (55). , Which are opposed to the removal preventing engagement grooves (55a) (55a), and are overlapped with the sandwiching plate (71).

A mandrel unit (72) having a plurality of mandrel pieces (55) (55) sandwiched between such a pair of sandwiching plates (71) (71) is provided with a mandrel holding hole (73).
The mandrel unit (72) is fixed to the bridge part (54b) while holding the mandrel pieces (55) (55) by being press-fitted or tightly fitted into the inside of the mandrel unit from the rear side in the extrusion direction. ) And FIG. 8 (b), each male bearing part (59a) of the mandrel pieces (55) (55) has a female fitting hole (54a) of an annular part (54a).
It is located inside the c) in the protruding direction in the extrusion direction. Then, the lid member (56) is tightly fitted into the lid housing groove (57) of the bridge portion (54b) to assemble the male mold (52).

The female mold (53) includes a flow guide plate (11),
A female mold body (12) and a backup mold (13) are provided. The flow guide plate (11), the female mold body (12) and the backup mold (13) are the flow guide plate (11), the female mold body (12) and the backup mold (13) in the first embodiment. The description is omitted here.

In the extrusion die (51) according to the second embodiment, the flow guide plate (11), the female main body (12) and the backup mold (13) are the male (52) annular portion (54).
It is combined with the male mold (52) while being fitted and housed in the female mold fitting hole (54c) of a). Then, the combined male die (52) is held by a holding die member that holds a plurality of male dies (52) (52) (not shown), and a plurality of simultaneous extrusion processes are performed.

According to the extrusion die (51) of the second embodiment, the same effect as that of the extrusion die (1) of the first embodiment can be obtained. Further, the extrusion die (51) is different from the extrusion die (1) according to the first embodiment, and the mandrel pieces (55) (5
5) are not directly attached to the bridge portion (54b) but are sandwiched by a pair of sandwiching plates (71) to form a mandrel unit (72).
2) is attached by inserting it into the mandrel unit holding hole (73) formed in the bridge portion (54b). Therefore, the extrusion die (51) can be manufactured relatively easily. That is, in this extrusion die (51), the mandrel unit holding hole (73) (73) (73) that requires delicate work is formed while the mandrel unit holding hole (73) that is relatively large and easy to form is formed in the bridge portion (54b). ) ... is formed by a pair of sandwich plates (71) (71)
This can be performed relatively easily by forming the grooves (71a) (71a) ... on the opposing surfaces, and can be manufactured more easily than the extrusion die (1) of the first embodiment.
Therefore, a highly accurate extrusion die (51) can be manufactured.

Further, the sandwiching plates (71) (71) are provided with a ridge-like bulging portion (71b) at one end in the width direction, and a fitting recess (71c) at the other end in the width direction. The pair of sandwiching plates (71) (71) have their bulging portions (71b) (71b).
Since b) is superposed by being fitted in the other fitting concave portion (71c) (71c), it is possible to accurately position and superpose, and the sandwiching plate (71) having the same shape.
With this, a pair of sandwiching plates (71) (71) can be configured, and the manufacturing cost can be reduced.

As described above, the extrusion dies (1) (5) for the porous tube material (T) according to the embodiments of the first and second inventions.
Although 1) has been described, these inventions are not limited to the above embodiments, and various modifications can be made without departing from the spirit of the invention.

[0062]

As described above, according to the die for extruding the porous tube material of the first aspect of the present invention, the die can be processed regardless of the gap between the male bearing portions, and the male bearing portion has a sectional shape. Fine processing can be performed by arbitrarily setting the size and size. Moreover, it is possible to form a smooth surface by polishing the surface of the male bearing portion,
By forming in this way, the resistance to extrusion can be suppressed as much as possible. Therefore, even when the hollow density is increased by increasing the number of holes in the porous tube material,
The damage to the male bearing portion can be minimized, and the male bearing portion can be extruded at a relatively high speed to improve the production efficiency. Also, since a separate mandrel piece is inserted and fixed in the mandrel piece holding hole, use expensive cemented carbide material for the mandrel piece and use inexpensive steel material such as die steel for the other male member. Since it is good, the component cost can be reduced. Further, when the mandrel piece is damaged, only the mandrel piece needs to be replaced, so that repair and maintenance costs can be reduced.

Further, in the first invention, in the case where the mandrel piece holding holes are formed such that the holding holes adjacent to each other are communicated with each other through the narrow communicating hole penetrating in the extruding direction at the intermediate portion in the height direction. The mandrel piece is firmly fixed by the bridge portion, and the mandrel piece is reliably prevented from being pulled out in the pushing direction.

Further, in the first aspect of the invention, when the mandrel piece is provided with a means for preventing the mandrel piece from being pulled out in the extruding direction at the rear end thereof, the mandrel piece is more surely prevented from being pulled out in the extruding direction. There is an advantage that

According to the extrusion die of the second invention,
In addition to the same effects as the first invention, there is an effect that the extrusion die can be manufactured relatively easily. That is, in this extrusion die, a relatively large mandrel unit holding hole is formed in the bridge portion, while a mandrel piece holding hole that requires delicate work is formed on at least one opposing surface of a pair of sandwiching plates with a groove. And the like can be performed relatively easily and can be manufactured more easily than the extrusion die of the first invention. Therefore, a highly accurate extrusion die can be manufactured.

In the second aspect of the present invention, in the mandrel piece holding holes, when the holding holes adjacent to each other are communicated with each other through a narrow communication hole penetrating in the extruding direction at an intermediate portion in the height direction, As in the case of the above-mentioned first invention, the mandrel piece is more firmly held by the holding plate,
Withdrawal of the mandrel piece in the extrusion direction is reliably prevented.

In the second aspect of the invention, when the mandrel piece is provided with means for preventing the mandrel piece from pulling out in the direction of extrusion in the rear end portion, as in the case of the first aspect of the invention, the direction of extrusion is the same. There is an advantage that the removal of the mandrel piece from the inside can be prevented more reliably.

Further, in the second aspect of the present invention, the sandwiching plate is provided with a bulging portion at one end in the width direction and a fitting recess at the other end in the width direction, so that a pair of sandwiching plates are sandwiched. When the plates are overlapped with each other by fitting their bulging portions into the other fitting recesses, a pair of sandwiching plates can be formed by sandwiching plates of the same shape, The production cost can be reduced. Further, there is an advantage that the pair of sandwiching plates can be accurately positioned and overlapped with each other, and the mandrel piece can be reliably sandwiched.

[Brief description of drawings]

FIG. 1 is a perspective view showing an extruding die of a porous tube material according to an embodiment of the first invention in a separated state.

FIG. 2A is a vertical sectional view of the extrusion die. FIG. 6B is an enlarged view of the tip of the mandrel piece in FIG. FIG. 3C is an enlarged view of the removal prevention unit of FIG.

FIG. 3A is a sectional view taken along line III-III in FIG. FIG. 2B is an enlarged view of a main part of FIG.

FIG. 4 is an enlarged perspective view showing a mounted state of the mandrel piece of the die for extruding a porous tube material according to the embodiment of the first invention.

FIG. 5 is a rear view of the bridge portion according to the embodiment of the first invention.

FIG. 6 is a perspective view showing, in a separated state, an extrusion die for a porous tube material according to an embodiment of the second invention.

FIG. 7A is a vertical sectional view of the extrusion die. FIG. 6B is an enlarged view of the tip of the mandrel piece in FIG. FIG. 3C is an enlarged view of the removal prevention unit of FIG.

FIG. 8 (a) is a cross-sectional view taken along line VIII-VIII in FIG.
It is a line sectional view. FIG. 2B is an enlarged cross-sectional view of the main part of FIG.

FIG. 9 is an exploded perspective view of the mandrel unit according to the second embodiment of the invention.

FIG. 10 is a perspective view showing a flat porous tube material manufactured by the extrusion die of the present embodiment.

FIG. 11 is a cross-sectional view showing a conventional extrusion die.

FIG. 12 is a perspective view showing a flat porous tube material manufactured by a conventional extrusion die.

[Explanation of symbols]

1 ... Extrusion die 2 ... Male 3 ... Female 4 ... Annular substrate 4a ... Ring part 4b ... Bridge section 5 ... Mandrel piece 8 ... Mandrel piece holding hole 8a ... narrow communication hole 9a ... Male bearing part 71 ... Sandwich plate 72 ... Mandrel unit 73 ... Mandrel unit holding hole

Claims (7)

[Claims] 1. A male die having a bridge portion along the radial direction of a ring portion for molding a hole portion of a porous tube material, and a female die combined with the male die for molding an outer peripheral portion of the porous tube material. The needle-shaped mandrel pieces are inserted into the respective holding holes of the plurality of mandrel piece holding holes which are arranged in the longitudinal direction of the bridge portion and penetrate in the extruding direction, with the tip portions protruding from the bridge portion. It is fixed, and a male bearing portion that molds each hole portion of the porous tube material is bulged and formed at the tip of each mandrel piece, and the male bearing portion has a smooth surface. A die for extrusion of porous tube material. 2. The perforated tube according to claim 1, wherein the mandrel piece holding holes are formed such that the holding holes adjacent to each other are communicated with each other through a narrow communication hole penetrating in an extruding direction at an intermediate portion in the height direction. Die for material extrusion. 3. The die for extruding a porous tube material according to claim 1, wherein the mandrel piece is provided with a means for preventing the mandrel piece from being pulled out in the extruding direction at its rear end portion. 4. A male die having a bridge portion extending along the radial direction of the ring portion for molding the hole portion of the porous tube material, and a female die combined with the male die for molding the outer peripheral portion of the porous tube material. The mandrel unit holding hole formed by penetrating in the extrusion direction in the bridge portion, the mandrel unit is inserted and fixed, the mandrel unit is formed by stacking a plurality of mandrel piece holding holes along the extrusion direction. It is composed of a pair of sandwiching plates and needle-shaped mandrel pieces which are separate from each other and arranged in each holding hole, and each hole portion of the porous tube material is formed at the tip of each mandrel piece. The male bearing portion is bulged, and the surface of the male bearing portion is formed into a smooth surface. On the other hand, this mandrel piece has each tip portion protruding from the tip surface of the sandwiching plate. In state, extrusion die of the porous tube material, characterized by comprising sandwiched the pair of clamping plates. 5. The perforated tube material according to claim 4, wherein the mandrel piece holding holes are formed such that the holding holes adjacent to each other are communicated with each other through a narrow communication hole penetrating in an extrusion direction at an intermediate portion in the width direction. Die for extrusion. 6. The extrusion die for a porous tube material according to claim 4, wherein the mandrel piece is provided at its rear end portion with a device for preventing removal in the extrusion direction. 7. The sandwich plate is provided with a bulging portion at one widthwise end portion thereof, and is provided with a fitting recess at the other widthwise end portion thereof, and the pair of sandwiching plates are mutually expanded. The extrusion die for perforated tube material according to any one of claims 4 to 6, wherein the protruding portion is fitted into the other fitting recessed portion so as to be overlapped with each other.