JPH0557337A - Hollow die for extruding cone form - Google Patents

Abstract

PURPOSE:To stably form a small and thin-walled flat porous tube for heat exchanger by the hollow die with a bearing slow in progress of wear. CONSTITUTION:In a hollow die 2 for extruding cone form, a male die 3 is divided into plural pieces of die member including a carbide mandrel chip 6. Further, a female die 4, too, is divided into plural pieces of die member including a carbide female die body piece 20. When wear of bearing progresses, forming is carried out advantageously and satisfactorily only by changing over a mandrel chip 6 and the carbide female die body piece 20 and leaving other die members as they are.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hollow extruder for conforming, which is used for extruding small metal molds such as flat aluminum perforated tubes for heat exchangers.

[0002]

2. Description of the Related Art For example, an aluminum flat porous tube (1) for a heat exchanger as shown in FIG.
Recently, in order to meet the demands for improved performance and compactness of the heat exchanger, its wall thickness t is 0.3 to 0.5 m.
m, height h is 1.4 to 3 mm, width b is 16 to 20 mm, etc., and very delicate and small size tends to be used. Correspondingly, the tube (1) is also manufactured by conform extrusion, which can continuously extrude a small profile with a small extrusion ratio, instead of the conventional billet extrusion.

In the manufacturing by conform extrusion, as a die for extrusion, a small combination made of die steel (SKD61 type) in which a male mold integrally molded and a female mold also integrally molded are combined. Holloday was being used.

However, when the thin and small die material (1) as described above is manufactured by conform extrusion using an extrusion die made of die steel, wear of the die bearing portion progresses very rapidly, and the die The mold cost is increased due to frequent replacement of the mold, resulting in an increase in the cost of the product. In addition, wear often progressed during continuous extrusion, causing defects such as die marks in the die material product (1) in many cases. Further, particularly in the extrusion of the porous tube (1) as described above, since each forming convex portion for forming the hole is much smaller and this is due to the die steel, the strength is very weak, and therefore the breakage is caused. It is liable to occur and not only increases the die cost associated with replacement, but also causes various troubles during or during manufacturing.

Therefore, it may be considered to manufacture the above-mentioned conform extruding holo-dice with a hard metal.

However, the hard metal itself is very difficult to process, and the die used for conform extrusion is very small, which makes it difficult to manufacture the die. In addition, if the bearing is worn due to long-term use, the entire cemented carbide die must be replaced, which in turn causes a rise in die cost. Also, due to the design change, even when extruding mold materials having different cross-sectional shapes and dimensions, it is necessary to replace the entire cemented carbide die, and the same problem occurs.

In view of the above technical background, the present invention can reduce the wear of the bearing to prolong the life of the die, can be easily manufactured, and can reduce the die cost. The main purpose of the present invention is to provide a Hollow Rice for conform extrusion.

[0008]

In the above object, the first
The invention of consists of a combination of a male type and a female type, and the male type is
A thick-walled tubular first mantle die member having an extruded material flow hole in its shaft portion, a cemented carbide mandrel tip having a molding convex portion for molding the inner circumference of the die member at its tip, and the first mantle die And a bridge piece that is disposed across the extruded material flow hole of the member and holds the mandrel tip in the extruded material flow hole, while the female mold is a thick-walled tubular body integrated with the first outer mold member. A second outer mold member, a cemented female main body piece that is arranged in the second outer mold member and has a molding hole that molds the outer peripheral portion of the mold member; and the bridge piece in the second outer mold member. A glove for conform extrusion is characterized by having a ring-shaped spacer piece arranged between the cemented carbide female body piece and a welding chamber for the extruded material divided by the bridge piece.

A second aspect of the present invention comprises a combination of a male die and a female die, wherein the male die has a thick-walled tubular mantle die member having an extruded material flow hole in a shaft core, and an inner die member. A cemented carbide mandrel tip having a molding convex portion for molding the peripheral portion at the tip, and a bridge piece arranged across the extruded material flow hole of the mantle mold member and holding the mandrel tip in the extruded material flow hole. The gist of the present invention is a conformer extruding holo-dice.

Further, in a third aspect of the present invention, in the above-mentioned respective aspects, the cemented carbide mandrel tip is retained by being inserted and disposed in a through-hole-shaped holding hole formed in the bridge piece, and the holding hole is formed. The rear end opening is covered by a cover piece disposed adjacent to the rear portion of the bridge piece in the extrusion material flow hole of the first outer mold member,
In addition, the gist is that the rear surface side of the cover piece is formed in a mountain shape with the peak facing backward.

Furthermore, in a fourth aspect of the present invention, in the above-mentioned respective aspects, the cemented carbide mandrel tip has an engaging abutting portion facing the tip end in the middle portion in the lengthwise direction, and the inside of the holding hole of the bridge piece. The engaging abutting portion facing the base end side is formed in the middle portion in the length direction, and the abutting portions abut each other, whereby the cemented carbide mandrel tip is held in the engaged state by the bridge piece. The main point is to be present.

A fifth aspect of the present invention comprises a combination of a male die and a female die, wherein the female die is provided with a thick-walled tubular outer metal mold member and the outer metal mold member. A cemented carbide female body piece having a molding hole for molding the outer peripheral portion, and a ring shape which is disposed adjacent to the rear portion of the cemented carbide female body piece in the second outer mold member and forms a welding chamber for the extruded material. The gist of the present invention is a conformer extruding hollow chair characterized by having a spacer piece.

[0013]

In the conforming extrusion hollow rice according to the first and second aspects of the present invention, the male mandrel tip forming convex portion is made of cemented carbide so that bearing wear due to extrusion is small and die life is extended. It Moreover, since the male mold has a split structure having the mantle mold member, the cemented carbide mandrel tip, and the bridge piece, it is necessary to process and manufacture each of the male mold members. Well, generally, it can be easily manufactured as a small-sized conform extrusion die. in addition,
Since the mandrel tip is made of cemented carbide and is separated from the others, the mandrel tip can be manufactured with a small amount of processing, and the difficulty associated with the manufacturing process of the male mold is greatly reduced. .. Moreover, even if bearing wear occurs on the convex portion of the mandrel tip molding, or if the standard of the mold material to be molded is changed, only the mandrel tip needs to be replaced or changed, and the others can be used as they are. It is no longer necessary to prepare the dice.

Further, in the conform extruding holo-dice according to the first and fifth aspects of the present invention, since the female main body piece is made of cemented carbide, bearing wear due to extrusion is small and die life is extended. .. Moreover, since the female die is divided into the outer die member, the female body piece, and the spacer piece, each of the female die members can be manufactured by working. Well, generally, it can be easily manufactured as a small-sized conform extrusion die. In addition, since the female die body piece is made of carbide and is separated from the others, the amount of machining is small in the production of the female die body piece, which makes it difficult to manufacture the female die. Sex is greatly reduced. Moreover, even if the bearing wear of the female body molding hole occurs, or if the standard of the mold material to be molded is changed, only the female body piece needs to be replaced or changed. There is no need to prepare a new die.

Further, in the conform extruding hollow chair according to the third aspect of the present invention, the cover piece is disposed adjacent to the rear portion of the bridge piece, and the rear end opening of the bridge piece holding hole is covered by the cover piece. Because of the peeling, not only the extruding pressure does not act on the rear end of the mandrel tip during extrusion, but also the extruded material is prevented from entering between the peripheral wall of the holding hole and the mandrel tip, and the mandrel tip is replaced. At this time, the work of separating the chip and the bridge piece becomes easy. Moreover, since the rear surface side of the cover piece is formed in the shape of a mountain with the peak facing backward, a dead metal portion is not formed at the rear portion of the cover piece during extrusion, and therefore the extruded material The flow becomes smooth and the extrusion speed is increased.

Further, in the conform extruding hollow rice according to the fourth aspect of the invention, the cemented carbide mandrel tip has an engaging abutting portion facing the tip end at the middle portion in the longitudinal direction thereof, and a holding hole for the bridge piece. An engaging contact portion facing the base end side is formed in the middle portion in the longitudinal direction, and the contact portions are brought into contact with each other, whereby the cemented carbide mandrel tip is held in an engaged state by the bridge piece. By doing so, the mounting state of the cemented carbide mandrel tip, which is made extremely small as a conform extrusion die, becomes stable.

[0017]

EXAMPLE Next, an example in which the conform extruding holo-dice of the present invention is applied to a die for molding and manufacturing a flat porous tube (1) for a heat exchanger as shown in FIG. 4 will be described.

In the conform extruding hollodeice (2) shown in FIGS. 1 to 3, (3) is a male type,
(4) is a female type.

The male mold (3) comprises a first outer mold member (5),
The mold is a combination of a mandrel tip (6), a bridge piece (7), and a cover piece (8).

The first outer mold member (5) is a thick-walled cylindrical member made of die steel and has a hollow portion as an extruded material flow hole (9). On the inner peripheral surface of the extrusion material flow hole (9), two key grooves (1 with a semicircular cross section extending in the axial direction are provided.
0) and (10) are formed to face each other with their phases different from each other by 180 °. Incidentally, the specific dimensions of this outer mold are, for example, an outer diameter of 65 mm and an inner diameter of 30 mm.

The mandrel tip (6) is a flat plate-shaped mold member made of superhard metal, and the tube (1) is attached to the tip of the mold member.
Small molding protrusions (11) that mold each hollow part (1a) ...
A large number of ... Are provided in parallel. Each of the molding convex portions (11) of the mandrel tip (6) is easily formed by performing wire-cut electric discharge machining using a wire as an electric discharge machining electrode. In addition, the base end portion is formed wider than the front end side through the step, whereby the left and right engaging contact portions (12) (1) facing the front in the extrusion direction.
2) is formed.

The bridge piece (7) is a die member made of die steel and is formed in an elliptical cross section, and the middle portion thereof has a first portion.
When the extruded material flow hole (9) of the mantle mold member (5) is crossed, both key grooves (10) of the flow hole (9) are provided on both sides.
It is supposed to fit into the inside of (10).
The bridge piece (7) is provided with a slit-shaped holding hole (13) extending in the longitudinal direction and penetrating therethrough. The inside of the holding hole (13) has substantially the same width as the base end side of the mandrel tip (6), and the tip end side of the mandrel tip (6) via the step portion. Of the mandrel tip (6) is formed in a stepped slit hole having substantially the same width as the width of the mandrel tip (6).
Is inserted into the holding hole (13) of the bridge piece (7) from the rear end opening side, the engaging abutting portions (12) (14) abut each other, and the molding convex portion (1) of the mandrel tip (6)
1) is held in a state of protruding a predetermined distance in front of the bridge piece (7). In this state, the rear end face of the mandrel tip (6) and the rear end face of the bridge piece (7) are substantially flush with each other. In addition, the rear end surface of the bridge piece (7) is formed as a flat surface for arranging the cover piece (8) adjacent to each other in a surface contact state, and the front end both side surfaces make the flow of the extruded material smooth. Because of this, the inclined taper surface (15)
It is formed in (15).

The cover piece (8) is a die member made of die steel, and like the bridge piece (7), is formed to have an oval cross section, and the middle portion thereof is an extruded material of the first outer die member (5). Both sides of the flow hole (9) are fitted into the key grooves (10) (10) of the flow hole (9) in a conforming manner while crossing the flow hole (9). This cover piece (8)
The front end surface of the bridge piece (7) is arranged in surface contact with the rear flat surface of the bridge piece (7) to cover the rear end opening of the holding hole (13) of the bridge piece (7) so as to cover it. It has been done. Then, the rear end side of the cover piece (8) is formed in a mountain-shaped cross-section with its peak facing backward so that the extruded material can be circulated by the mountain-shaped portion (16) without producing a dead metal portion. Has been done.

On the other hand, the female die (4) is a die in which the second outer die member (18), the spacer piece (19) and the female die body piece (20) are combined.

The second mantle die member (18) is made of die steel and is a thick-walled cylindrical die member which is integrally connected to the first mantle die member (5) of the male die (3). Is. And
A semi-circular key groove (21) (21) is provided on the inner peripheral portion of the first outer mold member (5) continuously corresponding to the key groove (10) (10) of the inner peripheral portion. Has been.

The spacer piece (19) is a ring-shaped mold member made of die steel and having a predetermined height, and is inserted and arranged in the second outer mold member (18) in a conforming manner. Then, a pair of engaging projections (22) (22) having semicircular cross sections with 180 ° different phases are provided on the outer peripheral portion thereof, and in a state of being inserted into the outer mold member (18), The engaging projections (22) (22) are fitted in the key grooves (21) (21) in a conforming manner.

The female main body chip (20) is a die member made of superhard metal, and is inserted and arranged in the second outer die member (18) in a conformable state like the spacer piece (19). ing. An oval-shaped forming hole (23) corresponding to the outer peripheral shape of the tube (1) is formed in the shaft core portion. Further, a pair of engaging protrusions (24) (24) having a semicircular cross section are formed on the outer peripheral portion thereof with 180 ° different phases, similarly to the spacer mold member (19). 2 It is adapted to be fitted in the key grooves (21) (21) in the outer mold member (18) in a conforming state.

The mold members are assembled into a die as follows. That is, bridge piece (7)
The carbide mandrel tip (6) is inserted into the holding hole (13) from the rear side of the holding hole (13) to bring the engaging contact surfaces (12) and (14) into contact with each other. Then, a bridge piece in which a female main body piece (20), a spacer piece (19), and a cemented carbide mandrel tip (6) are held in a thick-walled cylinder formed by the first and second outer mold members (5) (18). (7) Insert the cover piece (8) in the state of engaging the key grooves (10) and (21) one after another. Then, the thick cylindrical body formed of the first and second outer mold members (5) (18) and the inner containing mold members (20) (19) (7) (8) are shrink-fitted or cold-fitted. To integrate. The above is assembled into a die.
As a result, the molding protrusion (11) of the mandrel tip (6)
Project into the molding hole (23) of the female body piece (20),
A molding gap (27) conforming to the cross-sectional shape of the heat exchanger tube (1) is formed therein, and a spacer piece (19) is provided between the bridge piece (7) and the female body piece (20). A welding chamber (28) for joining the extruded materials divided by the bridge piece (7) is formed.

The above-mentioned combination die (1) is set in a conform extruder equipped with a rotating wheel and a fixed shoe and used for extrusion. During extrusion, the extruded material is divided by the cover piece (8) and flows into the hollolander (1). During this inflow, the extruded material is divided along the mountain-shaped portion (16) on the rear end side of the cover piece (8), so that no dead metal portion is formed at the rear portion of the piece (8). Therefore, the flow of the extruded material becomes smooth, and the extrusion speed is increased. Also, the extruded material is
Due to the presence of the cover piece (8), it does not happen that it flows into a slight gap between the holding hole (13) of the bridge piece (7) and the mandrel tip (6).
Further, the extrusion pressure does not act on the rear end surface of the mandrel tip (6). Therefore also mandrel tip (6)
Holds the bridge piece (7) in an extremely stable state during extrusion without any risk of breakage and separation due to the extrusion pressure due to the abutment engagement action of the engagement abutment portions (12) (14). To be done. Then, the extruded materials divided into the cover piece (8) and the bridge piece (7) are joined together in the welding chamber (28) in the spacer piece (19), and
A tube for heat exchanger (passes through a molding gap (27) surrounded by the molding convex portion (11) of the carbide mandrel tip (6) and the molding hole (23) of the carbide female body piece (20). It is molded into 1). Since the molding gap (27) is surrounded by the superhard metal, the bearing wear is small, the molding gap can withstand continuous extrusion called conform extrusion, and defects such as die marks do not occur in the mold material.

Then, when bearing wear progresses by long-term continuous extrusion or when a tube having different standards is formed, the die (1) is disassembled to remove the cemented carbide mandrel tip (6) and the cemented carbide female. Take out the mold body piece (20). In this removal, the mandrel tip (6) and the bridge piece (7) are separated from each other by the use of the cover piece (8) to prevent the extruded residue from remaining between them. It is easily achieved by the rear drawer of the. Then, a new cemented carbide mandrel tip (6) and a cemented carbide female body piece (20) are prepared, the other die members are the same as those used in the die, and reassembled in the die in the same manner as above. And restart extrusion. As described above, when the wear of the bearing progresses, it is only necessary to replace the mandrel tip (6) and the cemented carbide female body piece (20), which is economical and can reduce the die cost.

Although specific examples have been described above, the die of the present invention is not limited to the case where it is used for molding the flat porous tube (1) as shown in FIG. It can be widely applied for conform extrusion molding of precision mold materials.

[0032]

As described above, the conform extruding holloidice according to the first and second inventions has less wear of the bearing due to extrusion and is less likely to die when the male type mandrel tip forming convex portion is made of carbide. It is possible to prolong the life, thereby reducing the die cost in extrusion, and continuously extruding a die material without defects such as die marks in conform extrusion, which is continuous extrusion. Moreover,
The male mold has a jacket mold member, a cemented carbide mandrel tip, and a divided structure having a bridge piece, so in manufacturing, each of the male mold members may be processed and manufactured, The conforming extrusion die, which is generally small, can be easily manufactured. In addition, since the mandrel tip is made of super-hard material and is separated from the others, the mandrel tip can be manufactured with a small amount of processing, and the difficulty associated with the male manufacturing process is greatly reduced. It can be reduced, which can contribute to a reduction in die cost. Moreover, even if bearing wear occurs on the convex portion of the mandrel tip molding, or if the standard of the mold material to be molded is changed, only the mandrel tip needs to be replaced or changed, and the others can be used as they are. It is not necessary to prepare a die, and the economical efficiency of the die can be improved. Further, in the conforming extrusion hollow rice of the first and fifth inventions, since the female main body piece is made of cemented carbide, bearing wear due to extrusion is small and die life can be extended. A die cost in extrusion can be reduced, and a mold material having no defects can be continuously extruded in conform extrusion which is continuous extrusion. Moreover, since the female die is divided into the outer die member, the female body piece, and the spacer piece, each of the female die members can be manufactured by working. Often, it is possible to easily manufacture the die for conform extrusion, which is generally small. In addition, the female body piece is made of carbide,
By making this a separate body from the others, the amount of processing in the production of the female main body piece can be small, and the difficulties associated with the production processing of the female die can be greatly reduced, contributing to the reduction of die cost. You can. Moreover, even if bearing wear occurs in the female main body piece molding hole, or when the standard of the mold material to be molded is changed, only the main body piece needs to be replaced or changed, and the others can be used as they are. It is not necessary to prepare a new die, and the economical efficiency of the die can be improved.

Further, in the conform extruding hollobody of the third invention, a cover piece is arranged adjacent to the rear portion of the bridge piece, and the rear end opening of the bridge piece holding hole is covered by the cover piece. Therefore, the action of the extrusion pressure on the rear end of the mandrel tip during extrusion is eliminated, and the holding force of the mandrel can be lowered,
Therefore, a very small male die as a conform extrusion die can be realized in a divided configuration. In addition, the extruded material is prevented from entering between the peripheral wall of the holding hole and the mandrel tip, so that the tip and the bridge piece can be easily separated when the mandrel tip is replaced.
Moreover, since the rear surface side of the cover piece is formed in the shape of a mountain with the peak facing backward, a dead metal portion is not formed at the rear portion of the cover piece during extrusion, and therefore the extruded material The flow becomes smooth, the extrusion speed can be increased, and the efficiency of the extrusion operation can be realized.

Further, in the conform extruding hollow rice according to the fourth aspect of the present invention, the cemented carbide mandrel tip has an engaging abutting portion facing the tip end at the middle portion in the longitudinal direction, and a holding hole for the bridge piece. An engaging contact portion facing the base end side is formed in the middle portion in the longitudinal direction, and the contact portions are brought into contact with each other, whereby the cemented carbide mandrel tip is held in an engaged state by the bridge piece. By doing so, it is possible to make the mounting state of the cemented carbide mandrel tip, which is made very small as a conform extrusion die, very stable.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a conform extrusion die according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a perspective view showing each mold member forming the die in a separated state.

FIG. 4 is a cross-sectional view of a flat porous tube for a heat exchanger.

[Explanation of symbols]

 1 ... Flat porous tube for heat exchanger 2 ... Conform extrusion die 3 ... Male type 4 ... Female type 5 ... First mantle die member 6 ... Carbide mandrel tip 7 ... Bridge piece 8 ... Cover piece 9 ... Extrusion material distribution Hole 11 ... Molding convex portion 13 ... Holding hole 16 ... Angled portion 18 ... Second mantle mold member 19 ... Spacer piece 20 ... Carbide female body piece 23 ... Molding hole 28 ... Welding chamber

Claims (5)

[Claims] 1. A combination of a male mold and a female mold, wherein the male mold molds a thick-walled tubular first outer mold member having an extruded material flow hole in a shaft core, and a mold member inner peripheral portion. A cemented carbide mandrel tip having a molding convex portion at the tip, and a bridge piece that is arranged across the extrusion material flow hole of the first mantle mold member and holds the mandrel tip in the extrusion material flow hole. On the other hand, the female die is provided with a second thick outer tubular mold member that is integral with the first outer mold member, and a molding hole that is arranged in the second outer mold member and molds the outer peripheral portion of the mold material. And a ring that is disposed between the bridge piece and the cemented carbide female body piece in the second outer mold member and that forms a welding chamber for the extruded material divided by the bridge piece. -Shaped spacer piece, and Hollow rice for conform extrusion. 2. A molding which comprises a combination of a male mold and a female mold, wherein the male mold molds a thick-walled tubular mantle mold member having an extruded material flow hole in a shaft core and an inner peripheral part of the mold material. A cemented carbide mandrel tip having a convex portion at its tip, and a bridge piece that is arranged across the extruded material flow hole of the outer mold member and holds the mandrel tip in the extruded material flow hole. Hol conformer for conform extrusion. 3. The cemented carbide mandrel tip is held by being inserted and arranged in a through-hole holding hole formed in a bridge piece, and the rear end opening of the holding hole is a first outer mold. The extruded material flow hole of the member is covered with a cover piece arranged adjacent to a rear portion of the bridge piece, and a rear surface side of the cover piece is formed in a mountain shape with a peak facing rearward. 1) The conformer extrusion hollow rice of 1) or (2). 4. The cemented carbide mandrel tip has an engaging abutting portion facing the tip end at the middle portion in the lengthwise direction, and a base end side in the middle portion in the lengthwise direction inside the holding hole of the bridge piece. The cemented carbide mandrel tip is held in an engaged state on the bridge piece by forming facing engaging abutting portions and abutting these abutting portions against each other. The conformer extruding holloyd rice according to any one of claims. 5. A combination of a male die and a female die, wherein the female die is a thick-walled tubular outer mold member, and a molding hole that is arranged in the outer mold member to mold the outer peripheral portion of the mold material. And a ring-shaped spacer piece that is disposed adjacent to the rear part of the cemented carbide female body piece in the second outer mold member and that forms a welding chamber for the extruded material. A conformer extruding hollow rice characterized by the following.