JP2003200212A - Die for extruding finely perforated tube, mandrel used for the die, and perforated tube manufactured using the die - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a die for extruding finely perforated tube in which any underfill of a partition is suppressed, and the width of hollow parts can be reduced. <P>SOLUTION: This die comprises a female die 30 to form an outer circumferential part of a tube 100 and a mandrel 2 combined therewith, the mandrel 2 has a body 21 and a plurality of columnar bodies 22 which are protruded in a comb-tooth manner from the body, and disposed in a row with intervals in the width direction, and an outer circumferential part of the tip of the columnar body forms a bearing part 25 to form inner circumferential surfaces of a plurality of hollow parts disposed in a row in the width direction of the tube. On the rear side in the extruding direction of the bearing part 25, at least one side outer surface of the thickness direction of the columnar body is recessed inwardly in the thickness direction of the position of the bearing part 25, and a pocket part 27 which is a space for filling a material is formed on one surface side in the thickness direction of the columnar body. In addition, a surface continuous to the pocket part 27 from a base end part of the columnar body 22 is inclined or curved for promoting introduction of the material into the pocket part, and the surface continuous to a bearing part from the pocket part is formed to be an inwardly projecting curved surface. <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 multi-hole tube having a large number of fine hollow portions, such as an aluminum flat tube for heat exchange of a heat exchanger, and an extrusion die for use in this die. The present invention relates to a mandrel, a multi-hole tube manufactured using the die, a heat exchange tube manufacturing method, a heat exchanger, and a heat exchanger manufacturing method.

[0002]

2. Description of the Related Art In a heat exchanger such as an aluminum condenser for an automobile, for example, generally, a large number of fine hollow portions 202 are arranged in a row in a width direction through partition walls 201 as shown in FIG. A flat heat exchange tube 200 called a harmonica tube is used.

When such a multi-hole tube is manufactured by extrusion molding, as an extrusion die, a die female die forming the outer peripheral portion of the tube and a die female die combined with this die die are shown in FIG.
The mandrel 300 as shown in FIG.

The mandrel 300 includes a body 301 and
It has a plurality of columnar bodies 302 protruding from the main body 301 like comb teeth and arranged at intervals in the width direction. An outer peripheral portion of the tip end of the columnar body 302 is arranged in the width direction of the pipe. The bare link portion 303 forms the inner peripheral surface of the plurality of hollow portions.

Such a mandrel 300 is assembled in a die female die with the tip bare link portion of the columnar body facing the opening of the die female die to form a die. At the time of extrusion, from the rear of the mandrel 300,
By pressing the molding material such as aluminum loaded in the container with a stem or the like, the molding material is applied to the female mold and the columnar body 3.
And the columnar body 3 of the mandrel 300.
The extruded tube is obtained by pouring into the gaps between 02 and continuously extruding from these gaps.

[0006]

By the way, in response to the demand for miniaturization and high performance of the heat exchanger, the multi-hole extrusion pipe 200 used for the heat exchanger has a thin partition wall 201 and a hollow portion 2.
The reduction of the width of 02 has been desired.
In order to realize this, the gap 304 between the bearing portions 303 of the adjacent columnar bodies 302 and the width of the bearing portion of the columnar bodies 302 are also made smaller with respect to the mandrel 300 of the die. Is required.

However, in the mandrel 300, if the gap 304 between the bearing portions of the adjacent columnar bodies 302 is made small, the molding material does not sufficiently flow into this gap at the time of extrusion, and a wall thickness is generated in the partition wall of the pipe. There was a problem.

In order to avoid this problem, as shown in FIG. 11, on the rear side of the bearing portion 303 in the pushing direction,
The widthwise outer surface of the columnar body 302 is recessed inward from the position of the bearing portion so that the adjacent columnar body 302
A pocket 305 consisting of a wide space is formed between
At the time of extrusion, by filling the pocket portion 305 with the molding material, a sufficient molding material can be supplied to the gap 304 between the adjacent bearing portions, and a measure for preventing the wall thinning may be taken.

However, especially when the number of fine hollow portions increases, the columnar body 302 is formed in the portion where the pocket portion 305 is formed.
Since the thickness in the width direction is reduced, if the width of the tip bearing portion of the columnar body 302 is reduced to reduce the width of the hollow portion 202 of the pipe 200, the pocket forming portion 30 is reduced.
In No. 5, the columnar body 302 had a reduced thickness in the width direction, the strength was lowered, and the columnar body 302 was easily damaged. Therefore, there is a limit in reducing the width of the hollow portion 202 of the tube 200.

It is an object of the present invention to provide a die for extruding a fine multi-hole pipe which can suppress the wall thickness of the partition wall and can reduce the width of the hollow portion.

Another object of the present invention is to provide a mandrel used for the die for extruding the fine multi-hole tube.

Still another object of the present invention is to provide a multi-hole tube manufactured by using the die for extruding the fine multi-hole tube.

Still another object of the present invention is to provide a method of manufacturing a heat exchange tube using the die.

Still another object of the present invention is to provide a heat exchanger using the heat exchange tube and a method for manufacturing the heat exchanger.

[0015]

According to the present invention, a pocket portion is formed in the thickness direction of a columnar body of a mandrel of an extrusion die, and the shape of the pocket portion is devised.

That is, the present invention is as follows. (1) A die female die forming an outer peripheral portion of a pipe, and a mandrel combined with the die female die are provided, and the mandrel is provided with a main body, and a comb tooth-like protrusion from the main body and spaced apart in the width direction. A plurality of columnar bodies provided, the outer peripheral portion of the tip end of the columnar body being a bearing portion forming the inner peripheral surface of a plurality of hollow portions arranged in the width direction of the pipe. On the rear side in the extrusion direction, at least one outer surface in the thickness direction of the columnar body is recessed inward in the thickness direction from the position of the bearing portion, so that at least one surface side in the thickness direction of the columnar body is molded. A pocket portion that is a material filling space is formed, and a surface of the columnar body that extends from the base end portion to the pocket portion is formed as an inclined surface or a curved surface for promoting introduction of the molding material into the pocket portion. Meanwhile, pocket Fine multihole pipe extrusion die, wherein the surface subsequent to the bearing portion is formed on the curved surface of the inner convex from. (2) The die for extruding a fine multi-hole tube according to item 1 above, wherein a reinforcing rib is formed so as to project from the tip surface of the columnar body. (3) The fine multi-hole tube extrusion die according to item 1 or 2, wherein the width of the columnar body in the bearing portion is 2.0 mm or less, and the interval between the bearing portions of adjacent columnar bodies is 0.6 mm or less. (4) The fine multi-hole tube extrusion die according to any one of items 1 to 3, wherein a groove is formed on at least one surface of the columnar body in the bearing portion in the thickness direction. (5) A mandrel to be combined with a female die for forming an outer peripheral portion of a pipe, comprising a main body and a plurality of columnar bodies protruding from the main body in a comb-like shape and arranged at intervals in the width direction. The columnar body has a tip outer peripheral portion that serves as a bearing portion that forms an inner peripheral surface of a plurality of hollow portions that are arranged in a row in the width direction of the pipe. At least one outer surface in the thickness direction of the body is recessed inward in the thickness direction with respect to the position of the bearing portion, thereby forming a pocket portion that is a space for filling the molding material on at least one surface side in the thickness direction of the columnar body. Has been done,
The surface of the columnar body continuing from the base end portion to the pocket portion is formed as an inclined surface or a curved surface for promoting introduction of the molding material into the pocket portion, while the surface continuing from the pocket portion to the bearing portion is inward. A mandrel for use in a die for extruding a fine multi-hole tube, which is formed on a convex curved surface. (6) The mandrel according to the above item 5, wherein a reinforcing rib is formed so as to project from the tip end surface of the columnar body. (7) The mandrel according to the above item 5 or 6, wherein the width of the columnar body in the bearing portion is 2.0 mm or less, and the interval between the bearing portions of the adjacent columnar bodies is 0.6 mm or less. (8) The fine multi-hole tube extrusion die according to any one of the above items 5 to 7, wherein a groove is formed on at least one surface of the columnar body in the bearing portion in the thickness direction. (9) An extrusion die including a die female die forming an outer peripheral portion of a pipe and a mandrel combined with the die female die, wherein the mandrel has a main body and a comb-like protruding width from the main body. Bearing having a plurality of columnar bodies arranged in a row at intervals in the direction, and the outer peripheral end of the columnar body forming an inner peripheral surface of a plurality of hollow portions arranged in the width direction of the pipe. Is formed in the thickness direction of the columnar body, at least one side outer surface in the thickness direction of the columnar body is recessed inward in the thickness direction from the position of the bearing portion on the rear side in the extrusion direction with respect to the bearing portion. On at least one surface side of which a pocket portion that is a molding material filling space is formed, and the surface that continues from the base end portion of the columnar body to the pocket portion is a slope for promoting introduction of the molding material into the pocket portion. Shaped into a surface or curved surface On the other hand, the surface continuing from the pocket portion to the bearing portion is manufactured by using an extrusion die in which a curved surface having an inward convex shape is produced, and a large number of minute hollow portions partitioned by partition walls in the width direction are provided. Multi-hole tube with. (10) The fine multi-hole tube according to the above item 9, wherein a reinforcing rib is formed so as to project from a tip end surface of a columnar body of the extrusion die. (11) The fine multi-hole tube according to item 9 or 10, wherein the hollow portion has a width of 2.0 mm or less and the partition wall has a wall thickness of 0.6 mm or less. (12) The protrusion is formed between the adjacent partition walls in the hollow portion by forming the groove portion on at least one surface in the thickness direction of the columnar body in the bearing portion of the extrusion die. The fine multi-hole tube according to any one of the above. (13) A die female die that forms the outer peripheral portion of the pipe, and a mandrel that is combined with the die female die are provided. The mandrel has a main body and a comb-teeth-shaped protrusion from the main body, which is arranged at intervals in the width direction. A plurality of columnar bodies provided, the outer peripheral portion of the tip end of the columnar body being a bearing portion forming the inner peripheral surface of a plurality of hollow portions arranged in the width direction of the pipe. On the rear side in the extrusion direction, at least one outer surface in the thickness direction of the columnar body is recessed inward in the thickness direction from the position of the bearing portion, so that at least one surface side in the thickness direction of the columnar body is molded. A pocket portion that is a material filling space is formed, and a surface of the columnar body that extends from the base end portion to the pocket portion is formed as an inclined surface or a curved surface for promoting introduction of the molding material into the pocket portion. Meanwhile, pocket Using the extrusion die of the side next to the bearing portion is formed on the curved surface of the inner convex from parts,
A method for producing a heat exchange tube, which comprises extruding a molding material from the extrusion die. (14) The method for manufacturing a heat exchange tube according to the above item 13, wherein reinforcing ribs are formed so as to project from the tip end surface of the columnar body of the extrusion die. (15) The width of the columnar body in the bearing portion of the extrusion die is 2.0 mm or less, and the interval between the bearing portions of the adjacent columnar bodies is 0.6 mm or less.
4. The method for manufacturing the heat exchange tube according to item 4. (16) The method for manufacturing a heat exchange tube according to any one of the above items 13 to 15, wherein a groove is formed on at least one surface in the thickness direction of the columnar body in the bearing portion of the extrusion die. (17) A die for extrusion, comprising a female die for forming an outer peripheral portion of a pipe, and a mandrel combined with the female die, wherein the mandrel has a main body and a comb-like protruding width from the main body. Bearing having a plurality of columnar bodies arranged in a row at intervals in the direction, and the outer peripheral end of the columnar body forming an inner peripheral surface of a plurality of hollow portions arranged in the width direction of the pipe. Is formed in the thickness direction of the columnar body, at least one side outer surface in the thickness direction of the columnar body is recessed inward in the thickness direction from the position of the bearing portion on the rear side in the extrusion direction with respect to the bearing portion. On at least one surface side of which a pocket portion that is a molding material filling space is formed, and the surface that continues from the base end portion of the columnar body to the pocket portion is a slope for promoting introduction of the molding material into the pocket portion. On a surface or curved surface On the other hand, a large number of minute hollow parts which are manufactured by using an extrusion die in which the surface continuing from the pocket part to the bearing part is formed into an inwardly convex curved surface, and which are partitioned by partition walls in the width direction. With a heat exchange tube having a. (18) The heat exchanger as recited in the aforementioned Item 17, wherein a reinforcing rib is projectingly formed on the tip end surface of the columnar body of the extrusion die. (19) The width of the hollow portion of the heat exchange tube is 2.0 mm or less, and the wall thickness of the partition wall is 0.6 mm or less.
Or the heat exchanger according to 18. (20) The above-mentioned items 17 to 1 in which a fin portion is formed so as to project between adjacent partition walls in the hollow portion of the heat exchange tube.
9. The heat exchanger according to any one of 9. (21) An extrusion die comprising a die female die forming an outer peripheral portion of a pipe and a mandrel combined with the die female die, wherein the mandrel is a body and a width protruding from the body in a comb shape. Bearing having a plurality of columnar bodies arranged in a row at intervals in the direction, and the outer peripheral end of the columnar body forming an inner peripheral surface of a plurality of hollow portions arranged in the width direction of the pipe. Is formed in the thickness direction of the columnar body, at least one side outer surface in the thickness direction of the columnar body is recessed inward in the thickness direction from the position of the bearing portion on the rear side in the extrusion direction with respect to the bearing portion. On at least one surface side of which a pocket portion that is a molding material filling space is formed, and the surface that continues from the base end portion of the columnar body to the pocket portion is a slope for promoting introduction of the molding material into the pocket portion. On a surface or curved surface On the other hand, a large number of minute hollow parts which are manufactured by using an extrusion die in which the surface continuing from the pocket part to the bearing part is formed into an inwardly convex curved surface, and which are partitioned by partition walls in the width direction. A method of manufacturing a heat exchanger, comprising using a heat exchange tube having: and brazing by alternately arranging the heat exchange tube and the outer fin. (22) The method for manufacturing a heat exchanger according to the above item 21, wherein reinforcing ribs are formed so as to project from the tip end surface of the columnar body of the extrusion die. (23) The width of the hollow portion of the heat exchange tube is 2.0 mm or less and the wall thickness of the partition wall is 0.6 mm or less.
22. The method for manufacturing the heat exchanger according to 22. (24) The above-mentioned items 21 to 2 in which fin portions are formed so as to project between adjacent partition walls in the hollow portion of the heat exchange tube.
4. The method for manufacturing the heat exchanger according to any one of 3 above.

That is, the first aspect of the present invention comprises a die female die forming the outer peripheral portion of the pipe, and a mandrel combined with the die female die, the mandrel comprising a body and a comb tooth from the body. Has a plurality of columnar bodies protruding in a line shape and arranged at intervals in the width direction, and the tip outer peripheral portion of the columnar body has an inner peripheral surface of a plurality of hollow portions arranged in the width direction of the pipe. Is formed as a bearing portion, and on the rear side in the extrusion direction with respect to the bearing portion, at least one outer surface in the thickness direction of the columnar body is recessed inward in the thickness direction with respect to the position of the bearing portion. At least one surface side in the thickness direction of the body, a pocket portion that is a molding material filling space is formed, and the surface from the base end portion of the columnar body to the pocket portion is introduced into the pocket portion of the molding material. Slope for promotion While formed stone curved surface in the fine multihole pipe extrusion die, wherein the surface subsequent to the bearing portion from the pocket portion is formed on the curved surface of the inner convex.

In this die for extruding a fine multi-hole tube, a pocket portion, which is a space for filling the molding material, is formed on at least one side of the columnar body of the mandrel in the thickness direction, and
Since the surface of the columnar body continuing from the base end portion to the pocket portion is formed into an inclined surface or a curved surface for promoting introduction of the molding material into the pocket portion, the molding material smoothly flows into the pocket portion during extrusion. Filled with. Therefore, a sufficient amount of molding material is supplied to the gap between the bearing portions of the adjacent columnar bodies. As a result, even if the gap between the bearing portions is reduced, the wall thickness of the partition wall of the pipe is suppressed. Moreover, since the widthwise pocket of the columnar body is not necessarily provided by reducing the thickness of the columnar body in the widthwise direction, the width of the columnar body in the bare link portion can be reduced correspondingly, and the hollow portion of the tube can be reduced. The width can be reduced.

Further, since the surface from the pocket portion to the bearing portion is formed as an inwardly convex curved surface, there is no corner portion, and stress concentration on the corner portion due to the extrusion pressure applied to the columnar body is avoided. It is possible to prevent the columnar body from being damaged.

By providing the pocket portion on at least one surface side in the thickness direction of the columnar body of the mandrel, the thickness of the columnar body in the thickness direction is reduced and the strength is reduced accordingly. Therefore, the reinforcing ribs may be formed so as to project from the tip end surface of the columnar body to improve the strength of the mandrel.

Further, the width of the columnar body in the bearing portion is 2.0 mm or less, and the interval between the bearing portions of the adjacent columnar bodies is 0.6 mm or less, so that the effect of the present invention can be particularly exerted. preferable.

Further, a groove may be formed on at least one surface in the thickness direction of the columnar body in the bearing portion. In this case, the protrusion corresponding to the groove is
Since it is formed into a multi-hole pipe, for example, when the multi-hole pipe is used as a heat exchange tube of a heat exchanger, this protrusion is used as an inner fin for increasing the contact area with the refrigerant flowing through the hollow portion. be able to.

A second aspect of the present invention is a mandrel which is combined with a female die for forming an outer peripheral portion of a pipe, and which is provided in a row with a main body and comb-shaped projections from the main body at intervals in the width direction. A plurality of columnar bodies formed, the outer peripheral portion of the tip end of the columnar body is a bearing portion that forms the inner peripheral surface of a plurality of hollow portions arranged in the width direction of the pipe. Also on the rear side in the extrusion direction, at least one outer surface in the thickness direction of the columnar body is recessed inward in the thickness direction from the position of the bearing portion, so that the molding material is formed on at least one surface side in the thickness direction of the columnar body. A pocket portion that is a space for filling is formed, and a surface that continues from the base end portion of the columnar body to the pocket portion is formed as an inclined surface or a curved surface for promoting introduction of the molding material into the pocket portion. , From the pocket In mandrel for use in fine multihole pipe extrusion die, wherein the surface subsequent to serial bearing portion is formed on the curved surface of the inner convex.

By combining this mandrel with a female die, it is possible to obtain a multi-hole pipe having a hollow portion with a small width without a wall in the partition wall.

Also in this mandrel, from the viewpoint of improving the strength, a reinforcing rib may be formed so as to project from the tip end surface of the columnar body. Further, the width of the columnar body in the bearing portion may be 2.0 mm or less, and the interval between the bearing portions of the adjacent columnar bodies may be 0.6 mm or less. Further, a groove portion may be formed on at least one surface in the thickness direction of the columnar body in the bearing portion.

A third aspect of the present invention is provided with a female die for forming an outer peripheral portion of the pipe and a mandrel combined with the female die, the mandrel having a main body and a comb-like shape from the main body. A plurality of columnar bodies protruding and arranged at intervals in the width direction, and the outer periphery of the tip of the columnar body forms the inner peripheral surface of a plurality of hollow portions arranged in the width direction of the pipe. The outer surface of at least one side in the thickness direction of the columnar body is recessed inward in the thickness direction from the position of the bearing portion on the rear side in the extrusion direction with respect to the bearing portion. A pocket portion that is a space for filling the molding material is formed on at least one surface side in the thickness direction, and a surface continuing from the base end portion of the columnar body to the pocket portion is for promoting introduction of the molding material into the pocket portion. Or the slope of While being formed on the surface, a large number of micro hollows manufactured by using an extrusion die in which the surface continuing from the pocket portion to the bearing portion is formed into an inwardly convex curved surface and partitioned by partition walls in the width direction. It is in a multi-hole tube with a section.

In this multi-hole tube, the width of the hollow portion having no wall in the partition wall can be made small.

In this multi-hole tube, reinforcing ribs may be formed so as to project from the tip end surface of the columnar body of the extrusion die,
The hollow portion of the multi-hole tube may have a width of 2.0 mm or less, and the partition wall may have a wall thickness of 0.6 mm or less. Further, a groove may be formed on at least one surface in the thickness direction of the columnar body in the bearing portion of the extrusion die, so that a protrusion may be formed between adjacent partition walls in the hollow portion.

A fourth aspect of the present invention is provided with a female die for forming an outer peripheral portion of the pipe, and a mandrel combined with the female die, the mandrel having a main body and a comb tooth shape from the main body. A plurality of columnar bodies protruding and arranged at intervals in the width direction, and the outer periphery of the tip of the columnar body forms the inner peripheral surface of a plurality of hollow portions arranged in the width direction of the pipe. The outer surface of at least one side in the thickness direction of the columnar body is recessed inward in the thickness direction from the position of the bearing portion on the rear side in the extrusion direction with respect to the bearing portion. A pocket portion that is a space for filling the molding material is formed on at least one surface side in the thickness direction, and a surface continuing from the base end portion of the columnar body to the pocket portion is for promoting introduction of the molding material into the pocket portion. Or the slope of A heat exchange characterized in that a molding material is extruded from the extrusion die, which is formed on the surface and on the other hand, the surface continuing from the pocket portion to the bearing portion is formed into an inwardly convex curved surface. There is a method of manufacturing the tube.

According to this manufacturing method, it is possible to manufacture a heat exchange tube having a hollow portion having a small width without a wall in the partition wall.

Also in this manufacturing method, the reinforcing ribs may be formed so as to project from the tip end surface of the columnar body of the extrusion die, and the width of the columnar body in the bearing portion of the extrusion die is 2.0 mm or less. The space between the bearing portions of the adjacent columnar bodies may be 0.6 mm or less, or a groove may be formed on at least one surface in the thickness direction of the columnar bodies in the bearing portion of the extrusion die.

A fifth aspect of the present invention is an extrusion die including a female die for forming an outer peripheral portion of a pipe and a mandrel combined with the female die, wherein the mandrel includes a main body, A plurality of columnar bodies protruding from the main body in a comb-like shape and arranged at intervals in the width direction, and the tip outer peripheral portion of the columnar bodies has a plurality of hollows arranged in the width direction of the pipe. At the rear side of the bearing portion in the extrusion direction, at least one outer surface in the thickness direction of the columnar body is recessed inward in the thickness direction from the position of the bearing portion. By doing so, on at least one surface side of the columnar body in the thickness direction, a pocket portion which is a molding material filling space is formed, and the surface continuing from the base end portion of the columnar body to the pocket portion is formed of a molding material. Guide to pocket It is manufactured by using an extrusion die, which is formed into an accelerating inclined surface or curved surface, and the surface from the pocket portion to the bearing portion is formed into an inwardly convex curved surface. A heat exchanger having a heat exchange tube having a large number of partitioned fine hollow portions.

In this heat exchanger, since the partition wall is provided with a heat exchange tube having a hollow portion with a narrow width and a small width, the heat exchange efficiency of the heat exchange tube and thus the heat exchange efficiency of the entire heat exchanger can be improved. .

Also in this heat exchanger, reinforcing ribs may be formed so as to project from the tip end surface of the columnar body of the extrusion die, the width of the hollow portion of the heat exchange tube is 2.0 mm or less, and the partition wall. May have a thickness of 0.6 mm or less,
Fin portions may be formed so as to project between adjacent partition walls in the hollow portion of the heat exchange tube.

A sixth aspect of the present invention is an extrusion die including a female die for forming an outer peripheral portion of a pipe and a mandrel combined with the female die, wherein the mandrel is a main body. And a plurality of columnar bodies protruding from the main body in a comb shape and arranged at intervals in the width direction, and the outer peripheral end of the columnar body has a plurality of columnar bodies arranged in the width direction of the pipe. It is made a bearing part that forms the inner peripheral surface of the hollow part of, in the extrusion direction rear side of the bearing part,
At least one outer surface in the thickness direction of the columnar body is recessed inward in the thickness direction with respect to the position of the bearing portion, so that at least one surface side in the thickness direction of the columnar body is a pocket portion that is a molding material filling space. And a surface continuing from the base end portion of the columnar body to the pocket portion is formed into an inclined surface or a curved surface for promoting introduction of the molding material into the pocket portion, while the pocket portion to the bearing portion are formed. The surface following is manufactured by using an extrusion die, which is formed into a curved surface having an inward convex shape, and using a heat exchange tube having a large number of minute hollow portions partitioned by partition walls in the width direction,
This is a method for manufacturing a heat exchanger in which the heat exchange tubes and the outer fins are alternately arranged and brazed.

In this manufacturing method, since the heat exchanging tube having a hollow portion having a small width and having no wall thickness in the partition wall is used, the heat exchanging efficiency of the heat exchanging tube and hence the heat exchanging efficiency of the whole can be improved. It will be possible.

Also in this method of manufacturing a heat exchanger, reinforcing ribs may be formed so as to project from the tip end surface of the columnar body of the extrusion die, and the width of the hollow portion of the heat exchange tube is 2.0 m.
The thickness of the partition wall may be equal to or smaller than m, and the wall thickness of the partition wall may be equal to or less than 0.6 mm. Alternatively, fin portions may be formed so as to project between adjacent partition walls in the hollow portion of the heat exchange tube.

[0038]

BEST MODE FOR CARRYING OUT THE INVENTION In the embodiments described below, the multi-hole pipe to be extruded is shown in FIGS.
As shown in FIG. 1, a flat tube 100 made of aluminum (including its alloy) is provided with a large number of minute hollow portions 102 arranged in a row in a width direction through partition walls 101, and heat exchange for refrigerant flow in a heat exchanger is performed. It is used for tubes. In addition, in both opposing wall portions in the thickness direction (vertical direction in FIG. 7) of this aluminum pipe, at the position of the central portion in the width direction of each hollow portion except the hollow portions on both sides in the width direction (horizontal direction in FIG. 7), The fin portions 1 projecting toward the opposite wall portions to intermediate positions
03 are integrally formed along the length direction of the aluminum tube 100. Therefore, the cross-sectional shape of each hollow portion excluding the hollow portions on both sides in the width direction is H-shaped.

FIG. 1 is a perspective view showing a mandrel 2 of an extrusion die 1 according to an embodiment of the present invention, and FIG. 2 is a front view of the female die 3 seen from the rear side (entrance side) in the extrusion direction, FIG. Is a sectional view taken along line III-III of FIG. 1 in a state where the female die 3 and the mandrel 2 are combined, and FIG. 4 is IV-IV of FIG.
It is a line sectional view.

In FIGS. 1 to 4, the die female die 3 is used.
Has a flat opening 31 corresponding to the outer peripheral shape of the aluminum pipe in the center of the rear surface in the extrusion direction,
An extruded material passage hole 32 that penetrates the die female die 3 in the axial direction is formed so as to communicate with the opening 31. A bare link portion 33 that defines the outer peripheral surface of the aluminum tube is formed at the edge of the opening 31.

On the other hand, the mandrel 2 is integrally formed with a flat mandrel main body 21 and comb-shaped projections from the tip of the mandrel main body 21, and is arranged in rows in the width direction (left and right direction in FIG. 4). It has a plurality of columnar bodies 22.

The mandrel body 21 has a continuous portion 23 connected to the columnar body 22 in the thickness direction (vertical direction in FIG. 4).
Both outer surfaces are inclined surfaces that taper toward the tip, and the molding material on both sides in the thickness direction of the mandrel body 21 easily flows into the columnar body 22 during extrusion.

The columnar body 22 is the aluminum tube 1
No. 00 hollow portions 102 are formed respectively, and the shape of the tip portion thereof corresponds to the cross-sectional shape of each hollow portion 102. That is, the columnar portions 22a on both sides in the row installation direction
In each columnar portion 22 except for, a groove portion 24 for forming the fin portion 103 of the aluminum tube 100 is formed to extend to an intermediate position in the thickness direction at the center portion of both surfaces in the thickness direction. The part 22 is an aluminum tube 10.
It is formed to have an H-shaped cross section corresponding to the cross-sectional shape of the hollow portion 102 of 0. Further, the groove portion 24 extends close to the base end portion of the columnar body 22. Further, the outer peripheral portion of the tip of the columnar body 22 serves as a bearing portion 25 that defines the inner peripheral surface of the hollow portion of the aluminum tube 100.

On the rear side of the bare link portion 25 in the extruding direction, both side surfaces of the columnar body 22 in the thickness direction are formed by the bearing portion 2.
5 is recessed inward from the position of 5, and a pocket portion 27 as a molding material filling space is formed in this portion.

Further, as shown in detail in FIG. 3, a surface 28 continuing from the base end portion of the columnar body 22 to the pocket portion 27.
Is a sloping surface, which results in a pocket 2 of molding material.
It is said that it will be possible to promote the introduction into 7. Instead of the inclined surface, it may be formed into a curved surface that can facilitate the introduction of the molding material into the pocket portion 27.

On the other hand, from the pocket 27 to the bearing 2
The surface 29 following 5 is formed as an inwardly convex curved surface.
The reason why the curved surface is formed in this manner is to prevent a corner portion from being generated on the surface 29 that continues from the pocket portion 27 to the bearing portion 25, and stress is concentrated on the corner portion during extrusion, so that the columnar body 2 is formed.
This is to prevent 2 from being damaged.

Further, in this embodiment, the width of the columnar body 22 is the same from the base end portion to the bearing portion 25, and there is no step difference until both side surfaces 26 in the width direction reach the bearing portion. It is formed on a flat surface. The columnar body 2
The second bearing portion 25 may be configured to project in the width direction. In this case, the step portion from both side surfaces of the columnar body 22 in the width direction to the bearing portion may be formed in a curved surface as in the thickness direction. Further, especially when the width of the columnar body 22 has a margin, a pocket portion may be provided between adjacent columnar bodies.

The mandrel 2 having the above structure is the columnar body 2
The tip portion of the columnar body 22 is arranged so as to face the opening 31 of the die female die 3 so that the bearing portion 25 at the tip of the die 2 and the bearing portion 33 of the die female die 3 face each other.
Is configured. The mandrel 2 may be combined with the die female die in a state of being fixedly supported by shrink fitting or the like on a support body (not shown), if necessary. Further, the mandrel 2 may be divided into, for example, a mandrel body 21 and a columnar body 22, and these may be fixed by shrink fitting.

In this state, an aluminum billet as a molding material is loaded into a container (not shown) in which the die 1 is set, and extrusion is carried out according to a usual method. By the pressing, the aluminum molding material flows on both sides in the thickness direction of the mandrel 2 in the direction of the columnar body 22 along the inclined surface of the connecting portion 23 of the mandrel body 21 and the columnar body 22, as shown by the arrow in FIG. The pockets 27 formed on both sides of the columnar body 22 in the thickness direction are filled.

When the pressure is further applied, the molding material filled in the pocket portion has a gap 11 between the bearing portion 25 of the columnar body 22 and the female die bearing portion 33.
At the same time as being pushed out from the adjacent columnar bodies 22, it is sufficiently supplied between the adjacent columnar bodies 22 and the bearing portion 25 of the adjacent columnar bodies 22 is provided.
It is extruded from the gap 12 between them. And the molding material is
By continuously extruding from these gaps 11 and 12, the aluminum extruded pipe 100 having a cross-sectional shape as shown in FIG. 7 is manufactured.

At the time of this extrusion, the bearing portion 25 of each columnar body 22 receives a stress from the back to the front in the extrusion direction via the molding material filled in the pocket portion 27.
Since the surface 29 continuing from the pocket portion 27 to the bearing portion 25 is formed into a curved surface and has no corner portion, the stress is dispersed and damage to the columnar body is suppressed.

In the extrusion die according to this embodiment, the pocket portions 27 are formed on both sides of the columnar body 22 in the thickness direction, and no pocket portion is provided between each columnar body 22. Therefore, compared with the case where the width of each columnar body 22 is narrowed to form the pocket portion, the width of each columnar body at the bearing portion can be made smaller, and therefore the width of the hollow portion 102 of the aluminum tube can be reduced. Can be made smaller.

In addition, since the pocket portion 27 is provided in the thickness direction of the columnar body 22, as in the case where the pocket portion is provided in the width direction of the columnar body, the gap 12 in the width direction between the adjacent columnar bodies is sufficiently formed. Even if the material is supplied and the gap 12 is made small, it is possible to prevent the partition wall 101 of the aluminum tube 100 from being cut off.

Specifically, as shown in FIG. 1B, the width W of the columnar body 22 in the bearing portion 25 is 2.0 mm.
When the distance G between the bearing portions of the adjacent columnar bodies 22, 22 is set to 0.6 mm or less,
Great effect. That is, the thickness T1 of the partition wall 101 is 0.
When the width W1 of the hollow part 102 is 6 mm or less and the width W1 of the hollow part 102 is 2.0 mm or less, an effective effect is exhibited.

FIG. 5 shows a modification of the present invention. In this modification, two reinforcing ribs 5 are provided along the long side portion of the “H” shape on the front end surface of each columnar body 22 in the H shape in a front view.
It is a projecting 0. Thereby, the columnar body 22 can be reinforced against the back pressure (indicated by the arrow in FIG. 5C) applied to the bearing portion 33 of the columnar body 22 during extrusion.

In the above embodiment, the mandrel 2 is used.
Forming a columnar body having an H-shaped cross section to form a hollow portion 10 having an H-shaped cross section.
Although the case where the aluminum tube 100 having 2 is extruded is shown, as shown in FIG. 6, a large number of rectangular hollow portions 202 as shown in FIG. Aluminum tube 2 divided in the direction
It may be configured to push out 00. In FIG. 6, 50
Is a protruding reinforcing rib provided on the tip surface of the columnar body 22 as required.

FIG. 9 is a front view showing a parallel flow type condenser as a heat exchanger using the above-mentioned aluminum tube 100 or 200 as the heat exchange tube 250.

In this condenser, heat exchange tubes 250 made of aluminum tubes 100 or 200 and corrugated outer fins 251 made of aluminum are alternately arranged vertically, and both ends of the heat exchange tubes 250 are made of a pair of aluminum. It is connected to the headers 252 and 252. The heat exchange tube 250 and the header 252 are brazed together, and the heat exchange tube 250 and the outer fin 251 are also brazed together.

Numeral 253 shown in FIG.
4 is the same outlet, 255 is a pair of side plates arranged outside the outermost outer fin, and 256 is a partition that partitions the inside of each header 252 in order to make the refrigerant passage constituted by the heat exchange tube a meandering passage. And each of these heat exchanger components is also joined to the corresponding part by brazing.

In this heat exchanger, the heat exchange tube 250
As the aluminum tube 100 or 200 having a small hollow portion and a thin partition wall, the heat exchange efficiency is excellent. In particular, when the aluminum tube 100 is used as the heat exchange tube 250, the fin portion protruding between the adjacent partition walls functions as an inner fin, so that the heat exchange efficiency is further improved.

[0061]

EXAMPLE In order to show the effect of using the die according to this embodiment, the following test was conducted (Example 1). The hollow portion 102 having a rectangular cross section as shown in FIG.
As a die 1 for extruding aluminum tubes 200 arranged in the width direction, a columnar body 2 having a rectangular cross section as shown in FIG.
A die according to a conventional product, which includes a mandrel 2 having 2 and has a pocket portion formed between adjacent columnar bodies 22 in the width direction of the mandrel 2, and both sides in the thickness direction without forming the pocket portion in the width direction. A die according to the product of the present invention in which the pocket portion 27 was formed was used as a sample product. However,
The reinforcing rib 50 at the tip of the columnar body 22 was not provided.

Then, with the height H of the bare link portion 25 of the columnar body 22 being constant at 1.5 mm, the width W2 of the columnar body 22 (shown in FIG. 6) and the gap 12 between the adjacent columnar bodies 22 are set. The size G2 was set to various values as shown in Table 1, an aluminum billet was extruded, and the limit of extrusion moldability was examined. The results are shown in Table 1 and FIG. In FIG. 10, the vertical axis represents the size G2 of the gap 12 between the adjacent columnar bodies 22,
The horizontal axis represents the width W2 of the columnar body 22. The line connecting the black square points shows the extrusion molding limit of the conventional product, the line connecting the black circle points shows the extrusion molding limit of the actual product, and the upper right area surrounded by each line is the range where good extrusion can be performed. The lower left region indicates the range of poor extrusion or difficult extrusion.

[0063]

[Table 1]

As can be seen from Table 1 and FIG. 10, in the conventional product in which the pocket portion is formed in the width direction of the mandrel 22,
When the width W2 of the columnar body is 2.0 mm, the gap G2 is set to 0.1.
When the thickness is set to mm, the partition wall 201 is deficient or the columnar body itself is damaged. When the width W2 of the columnar body 22 is 1.0 mm, 0.8 mm, 0.5 mm and 0.25 mm, the gap G2 is 0.13 mm and 0.15 mm, respectively.
mm, 0.22 mm, 0.6 mm, the partition wall 20
No. 1 was lacked or the columnar body itself was damaged. On the other hand, in the product of the present invention in which the pocket portion is formed in the thickness direction of the mandrel, the width W2 of the columnar body 22 is 0.2 mm.
As described above, if the gap G2 is 0.08 mm or more, the partition wall 2
The lack of thickness 01 and the damage to the columnar body 22 did not occur. Also,
When the width W2 of the columnar body 22 is 0.15 mm, 0.1 m
When m and 0.05 mm, the gap G2 is 0.1
Even if it is 0 mm, 0.18 mm, or 0.6, the partition wall 20
The lack of thickness 1 and the breakage of the columnar body 22 did not occur.

Therefore, it was confirmed that the extrusion-molding limit can be raised according to the product of the present invention.

In the shaded portion of FIG. 10, it was difficult to extrude even this product. (Example 2) Using the same type of mandrel as in Example 1,
A die according to a conventional product in which a pocket portion is formed between adjacent columnar bodies 22 in the width direction of the mandrel 2, and the present invention in which the pocket portion is formed on both sides in the thickness direction without forming the pocket portion in the width direction The die related to the product was used as the sample. The reinforcing rib 50 at the tip of the columnar body was not provided.

With the height H of the bare link portion 25 of the columnar body 22 being 0.7 mm and the size G2 of the gap 12 between the adjacent columnar bodies 22 being 0.2 mm, the width W2 of the columnar body 22 is maintained. Was set to 0.5 mm, 0.8 mm, and 1.0 mm, respectively, and an aluminum billet was extruded to investigate the life of the die.

As a result, the width W2 of the columnar body 22 is 0.5 m.
In the case of m, in the conventional product, the die life was reached when a billet of 0.9 tons was extruded, while in the product of the present embodiment it was 2.1 tons, and the life of the product of the present embodiment was about 2.3 of that of the conventional product.
It was double. Further, when the width W2 of the columnar body 22 is 0.8 mm, the extruding amount up to the life of the conventional product was 1.5 tons, while the extruding amount of the present embodiment was 2.5 tons, which is about The life was 1.6 times longer. In addition, the width W2 of the columnar body 22
When the value was 1.0 mm, the extruded amount up to the life of the conventional product was 2.2 tons, whereas the extruded amount of this embodiment was 2.6 tons, which is about 1.18 times the life of the conventional product. It was

As described above, according to the product of the present invention, it is confirmed that the life can be extended as compared with the conventional product, and particularly the life can be remarkably extended when the width W2 of the columnar body 22 is set small. Obtained.

[0070]

As described above, the die female die forming the outer peripheral portion of the pipe and the mandrel combined with the die female die are provided, and the mandrel has a main body and a width protruding from the main body in a comb shape. Bearing having a plurality of columnar bodies arranged in a row at intervals in the direction, and the outer peripheral end of the columnar body forming an inner peripheral surface of a plurality of hollow portions arranged in the width direction of the pipe. Is formed in the thickness direction of the columnar body, at least one side outer surface in the thickness direction of the columnar body is recessed inward in the thickness direction from the position of the bearing portion on the rear side in the extrusion direction with respect to the bearing portion. On at least one surface side of which a pocket portion that is a molding material filling space is formed, and the surface that continues from the base end portion of the columnar body to the pocket portion is a slope for promoting introduction of the molding material into the pocket portion. On a surface or curved surface While made, according to the fine multihole pipe extrusion die, wherein the surface subsequent to the bearing portion from the pocket portion is formed on the curved surface of the inner convex,
At the time of extrusion, the molding material smoothly flows into and is filled in the pocket portion, so that a sufficient amount of the molding material is supplied to the gap between the bearing portions of the adjacent columnar bodies.

As a result, even if the gap between the bearing portions is made small, the wall thickness of the partition wall of the pipe is suppressed. Moreover, since the widthwise pocket of the columnar body is not necessarily provided by reducing the thickness of the columnar body in the widthwise direction, the width of the columnar body in the bare link portion can be reduced correspondingly, and the hollow portion of the tube can be reduced. The width can be reduced.

Further, since the surface continuing from the pocket portion to the bearing portion is formed as an inwardly convex curved surface, there is no corner portion, and stress concentration on the corner portion due to the extrusion pressure applied to the columnar body is avoided. It is possible to prevent the columnar body from being damaged.

In the extrusion die, when the reinforcing rib is formed so as to project from the tip end surface of the columnar body, the strength of the mandrel can be improved.

According to the extrusion die, the width of the columnar body in the bearing portion is 2.0 mm or less, and the interval between the bearing portions of the adjacent columnar bodies is 0.6 mm or less. Extrusion is also possible.

Further, when a groove is formed on at least one surface of the columnar body in the bearing portion in the thickness direction, the projecting portion corresponding to the groove is formed in the multi-hole pipe. When used as a heat exchange tube of a heat exchanger, this protrusion can be used as an inner fin for increasing the contact area with the refrigerant flowing through the hollow portion.

A mandrel to be combined with a female die for forming the outer peripheral portion of the tube, which comprises a main body and a plurality of columnar bodies protruding from the main body in a comb-teeth shape and arranged at intervals in the width direction. And a tip outer peripheral portion of the columnar body is a bearing portion forming an inner peripheral surface of a plurality of hollow portions arranged in a row in the width direction of the pipe, and on the rear side in the extrusion direction with respect to the bearing portion, At least one outer surface in the thickness direction of the columnar body is recessed inward in the thickness direction with respect to the position of the bearing portion, so that at least one surface side in the thickness direction of the columnar body is a pocket portion that is a molding material filling space. And a surface continuing from the base end portion of the columnar body to the pocket portion is formed into an inclined surface or a curved surface for promoting introduction of the molding material into the pocket portion, while the pocket portion to the bearing portion are formed. To According to the mandrel used in the die for extruding a fine multi-hole tube, which has a curved surface with an inwardly convex curved surface, the mandrel used in combination with the die female die has a hollow with no wall in the partition wall. It is possible to obtain a multi-hole tube having a small width.

In this mandrel, the strength can be improved when the reinforcing rib is formed so as to project from the tip end surface of the columnar body.

Further, when the width of the columnar body in the bearing portion is 2.0 mm or less and the interval between the bearing portions of the adjacent columnar bodies is 0.6 mm or less, the hollow portion of the multi-hole tube is extremely fine. It can be anything.

When a groove is formed on at least one surface of the columnar body in the bearing portion in the thickness direction, the protrusion can be used as an inner fin of a heat exchange tube, for example.

Further, a die female die for forming the outer peripheral portion of the pipe and a mandrel combined with the die female die are provided, and the mandrel is provided with a main body and a comb-teeth-shaped protrusion from the main body at intervals in the width direction. A plurality of columnar bodies arranged in a row, the outer peripheral portion of the tip end of the columnar body being a bearing portion forming an inner peripheral surface of a plurality of hollow portions arranged in the width direction of the pipe, On the rear side in the extrusion direction with respect to the bearing portion, at least one outer surface in the thickness direction of the columnar body is recessed inward in the thickness direction from the position of the bearing portion, so that at least one surface side in the thickness direction of the columnar body is formed. , A pocket portion that is a molding material filling space is formed,
The surface of the columnar body continuing from the base end portion to the pocket portion is formed as an inclined surface or a curved surface for promoting introduction of the molding material into the pocket portion, while the surface continuing from the pocket portion to the bearing portion is inward. According to the multi-hole tube having a large number of minute hollow portions partitioned by the partition wall in the width direction, which is manufactured by using the extrusion die formed on the convex curved surface, the partition wall has no hollow portion. It can be a multi-hole tube with a small width.

In this multi-hole tube, when a reinforcing rib is formed so as to project from the tip end surface of the columnar body of the extrusion die,
By improving the strength of the mandrel, it is possible to further eliminate the wall thickness of the partition wall and form a multi-hole tube having a smaller hollow portion width.

The width of the hollow portion of the multi-hole tube is 2.0 m.
When the wall thickness is m or less and the wall thickness of the partition wall is 0.6 mm or less, it is possible to form a multi-hole tube in which the width of the hollow portion is small and the wall thickness of the partition wall is thin.

In addition, when a groove is formed on at least one surface of the columnar body in the bearing portion of the extrusion die in the thickness direction, a protrusion is formed between adjacent partition walls in the hollow portion. The protrusion can be used as an inner fin of a heat exchange tube, for example.

Further, a die female die for forming the outer peripheral portion of the pipe and a mandrel to be combined with the die female die are provided, and the mandrel is provided with a main body and a comb tooth-like protrusion from the main body with a space in the width direction. A plurality of columnar bodies arranged in a row, the outer peripheral portion of the tip end of the columnar body being a bearing portion forming an inner peripheral surface of a plurality of hollow portions arranged in the width direction of the pipe, On the rear side in the extrusion direction with respect to the bearing portion, at least one outer surface in the thickness direction of the columnar body is recessed inward in the thickness direction from the position of the bearing portion, so that at least one surface side in the thickness direction of the columnar body is formed. , A pocket portion that is a molding material filling space is formed,
The surface of the columnar body continuing from the base end portion to the pocket portion is formed as an inclined surface or a curved surface for promoting introduction of the molding material into the pocket portion, while the surface continuing from the pocket portion to the bearing portion is inward. According to the manufacturing method of the heat exchange tube, which is characterized in that the extrusion die formed on the convex curved surface is used and the molding material is extruded from the extrusion die, the width of the hollow portion having no wall in the partition wall. It is possible to manufacture a heat exchange tube having a small size.

In this manufacturing method, when the reinforcing ribs are formed so as to project from the tip end surface of the columnar body of the extrusion die, the mandrel is improved in strength to further eliminate the wall thickness of the partition wall and to reduce the width of the hollow portion. Of smaller heat exchange tubes can be manufactured.

Further, when the width of the columnar body in the bearing portion of the extrusion die is 2.0 mm or less and the interval between the bearing portions of the adjacent columnar bodies is 0.6 mm or less, the width of the hollow portion is It is possible to manufacture a heat exchange tube having a small thickness of 2.0 mm or less and a partition wall thickness of 0.6 mm or less.

Further, when a groove is formed on at least one surface of the columnar body in the bearing portion of the extrusion die in the thickness direction, the fin portion is formed so as to project between the adjacent partition walls in the hollow portion. Exchange tubes can be manufactured.

Further, there is provided an extrusion die including a female die for forming an outer peripheral portion of the pipe and a mandrel combined with the female die, wherein the mandrel has a main body and a comb tooth shape from the main body. A plurality of columnar bodies protruding and arranged at intervals in the width direction, and the outer periphery of the tip of the columnar body forms the inner peripheral surface of a plurality of hollow portions arranged in the width direction of the pipe. The outer surface of at least one side in the thickness direction of the columnar body is recessed inward in the thickness direction from the position of the bearing portion on the rear side in the extrusion direction with respect to the bearing portion. A pocket portion that is a space for filling the molding material is formed on at least one surface side in the thickness direction, and a surface continuing from the base end portion of the columnar body to the pocket portion is for promoting introduction of the molding material into the pocket portion. The slope of While being formed into a curved surface, the extrusion die has a surface that continues from the pocket portion to the bearing portion is formed into an inwardly convex curved surface, and is manufactured by using a large number of partitions partitioned by a partition wall in the width direction. According to the heat exchanger provided with the heat exchange tube having the fine hollow portion, the heat exchange efficiency of the heat exchange tube and the heat of the entire heat exchanger can be improved by the heat exchange tube having a hollow portion with a small wall thickness without partition wall. The exchange efficiency can be improved.

In this heat exchanger, when the reinforcing ribs are formed so as to project from the tip end surface of the columnar body of the extrusion die, the partition wall of the heat exchange tube is further eliminated and the width of the hollow portion is further reduced. Since it is possible, it is possible to obtain a heat exchanger with even higher heat exchange efficiency.

In this heat exchanger, when the width of the hollow part of the heat exchange tube is 2.0 mm or less and the wall thickness of the partition wall is 0.6 mm or less, the width of the hollow part of the heat exchange tube is Since the partition wall is small and the wall thickness is thin, the heat exchange efficiency of the heat exchanger can be improved.

When the fins are formed so as to project between the adjacent partition walls in the hollow portion of the heat exchange tube, the heat exchange efficiency is further increased by the contact between the fins and the refrigerant flowing through the heat exchange tube. To do.

Further, there is provided an extrusion die including a female die for forming an outer peripheral portion of a tube and a mandrel combined with the female die, wherein the mandrel has a main body and a comb tooth shape from the main body. A plurality of columnar bodies protruding and arranged at intervals in the width direction, and the outer periphery of the tip of the columnar body forms the inner peripheral surface of a plurality of hollow portions arranged in the width direction of the pipe. The outer surface of at least one side in the thickness direction of the columnar body is recessed inward in the thickness direction from the position of the bearing portion on the rear side in the extrusion direction with respect to the bearing portion. A pocket portion that is a space for filling the molding material is formed on at least one surface side in the thickness direction, and a surface continuing from the base end portion of the columnar body to the pocket portion is for promoting introduction of the molding material into the pocket portion. The slope of While being formed into a curved surface, the extrusion die has a surface that continues from the pocket portion to the bearing portion is formed into an inwardly convex curved surface, and is manufactured by using a large number of partitions partitioned by a partition wall in the width direction. According to the method of manufacturing a heat exchanger in which a heat exchange tube having a minute hollow portion is brazed by alternately arranging the heat exchange tube and the outer fin, the width of the hollow portion having no wall thickness in the partition wall Since a small heat exchange tube is used, it becomes possible to manufacture a heat exchanger having excellent heat exchange efficiency of the heat exchange tube and thus excellent overall heat exchange efficiency.

In this method of manufacturing a heat exchanger, when the ribs of the extrusion die are formed with protruding reinforcing ribs on the tip end surface, the partition wall of the heat exchange tube is further prevented from being cut off and the width of the hollow portion is reduced. Can be further reduced, so that a heat exchanger with even higher heat exchange efficiency can be manufactured.

The width of the hollow portion of the heat exchange tube is 2.
When the thickness of the partition wall is 0 mm or less and the wall thickness of the partition wall is 0.6 mm or less, the heat exchange efficiency of the heat exchanger is good because the width of the hollow portion of the heat exchange tube is small and the wall thickness of the partition wall is thin. Can be done.

Further, when the fin portion is formed so as to project between the adjacent partition walls in the hollow portion of the heat exchange tube, the refrigerant flowing through the heat exchange tube is brought into contact with the fin portion to further improve the heat exchange efficiency. A heat exchanger can be manufactured.

[Brief description of drawings]

FIG. 1A is a perspective view showing a mandrel of an extrusion die according to an embodiment of the present invention, and FIG. 1B is a plan view of a columnar body.

FIG. 2 is a front view of the female die of the extrusion die as seen from the rear (entrance side) in the extrusion direction.

FIG. 3 is a cross-sectional view of essential parts of an extrusion die in which a female die and a mandrel are combined.

4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 shows a modified example of the present invention, in which (a) is a perspective view of a main part of a mandrel, (b) is a front view of a columnar body seen from the extrusion side, and (c) is a side surface of the columnar body. It is a figure.

FIG. 6 shows another embodiment of the present invention and is a front view of the main part of the mandrel as seen from the extrusion side.

7A is a sectional perspective view of an extruded aluminum tube manufactured by the die of FIGS. 1 to 4, and FIG. 7B is an enlarged front sectional view of the same.

8 (a) is a cross-sectional perspective view of an extruded aluminum tube manufactured by a die including the mandrel of FIG.
(B) is a front cross-sectional enlarged view of the same.

FIG. 9 is a front view of the heat exchanger according to the embodiment of the present invention.

FIG. 10 is a graph showing the results of a limit test of extrudability performed in Examples.

FIG. 11 is a perspective view of a mandrel used in a conventional extrusion die.

[Explanation of symbols]

1. Die 2. Mandrel 21. Mandrel main body 22. Columnar body 23. Connection part 25. Bearing part 27・ ・ ・ Pocket part 28 ・ ・ ・ Surface 29 continuing from the base end of the columnar body to the pocket part 29 ・ ・ ・ Surface continuing from the pocket part to the approach part 30 ・ ・ ・ ・ ・ Female die 50 ... Reinforcing ribs 100 ... Pipe 101 ... Partition wall 102 ... Hollow part 200 ... Pipe 201 ... Partition wall 202 ... Hollow part 250 ... ... Heat exchange tube 251 ... Outer fin

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Fumio Shimizu             Showaden 1-480 Inuzuka, Oyama City, Tochigi Prefecture             Koyama Works Co., Ltd. F-term (reference) 4E029 MB01 MB08 NA03

Claims (24)

[Claims] 1. A die female die for forming an outer peripheral portion of a pipe, and a mandrel combined with the die female die, wherein the mandrel has a main body and a comb tooth-like protrusion from the main body and is spaced in the width direction. A plurality of columnar bodies that are arranged in a row, and the outer peripheral portion of the tip of the columnar body is a bearing portion that forms the inner peripheral surface of a plurality of hollow portions that are arranged in a row in the width direction of the pipe. On the rear side in the extrusion direction with respect to the bearing portion, at least one outer surface in the thickness direction of the columnar body is recessed inward in the thickness direction from the position of the bearing portion, so that at least one surface side in the thickness direction of the columnar body is formed. A pocket portion that is a space for filling the molding material is formed, and a surface that continues from the base end portion of the columnar body to the pocket portion is formed as an inclined surface or a curved surface for promoting introduction of the molding material into the pocket portion. Meanwhile, A die for extruding a fine multi-hole tube, characterized in that a surface continuing from the pocket portion to the bearing portion is formed as an inwardly convex curved surface. 2. The die for extruding a fine multi-hole tube according to claim 1, wherein a reinforcing rib is formed so as to project on the tip surface of the columnar body. 3. The width of the columnar body in the bearing portion is 2.
The fine multi-hole tube extrusion die according to claim 1 or 2, wherein the distance between the bearing portions of adjacent columnar bodies is 0 mm or less, and the interval between the bearing portions of adjacent columnar bodies is 0.6 mm or less. 4. The fine multi-hole tube extrusion die according to claim 1, wherein a groove portion is formed on at least one surface of the columnar body in the bearing portion in the thickness direction. 5. A mandrel to be combined with a female die for forming an outer peripheral portion of a pipe, the main body and a plurality of columnar bodies protruding from the main body in a comb shape and spaced in the width direction. And a tip outer peripheral portion of the columnar body is a bearing portion forming an inner peripheral surface of a plurality of hollow portions arranged in a row in the width direction of the pipe, and on the rear side in the extrusion direction with respect to the bearing portion, At least one outer surface in the thickness direction of the columnar body is recessed inward in the thickness direction with respect to the position of the bearing portion, so that at least one surface side in the thickness direction of the columnar body is a pocket portion that is a molding material filling space. And a surface continuing from the base end portion of the columnar body to the pocket portion is formed as an inclined surface or a curved surface for promoting introduction of the molding material into the pocket portion, while the pocket portion to the bearing portion. followed by A mandrel for use in a die for extruding a fine multi-hole tube, the surface of which is formed as a curved surface that is convex inward. 6. The mandrel according to claim 5, wherein a reinforcing rib is formed so as to project from the tip surface of the columnar body. 7. The width of the columnar body in the bearing portion is 2.
The mandrel according to claim 5 or 6, wherein the mandrel is 0 mm or less, and the interval between the bearing portions of adjacent columnar bodies is 0.6 mm or less. 8. The die for extruding a fine multi-hole tube according to claim 5, wherein a groove portion is formed on at least one surface of the columnar body in the bearing portion in the thickness direction. 9. An extrusion die comprising a die female die forming an outer peripheral portion of a tube and a mandrel combined with the die female die, wherein the mandrel is a body and a comb tooth shape from the body. A plurality of columnar bodies protruding and arranged at intervals in the width direction, and the outer periphery of the tip of the columnar body forms the inner peripheral surface of a plurality of hollow portions arranged in the width direction of the pipe. Is formed into a bearing portion, and on the rear side in the extrusion direction with respect to the bearing portion, at least one outer surface in the thickness direction of the columnar body is recessed inward in the thickness direction with respect to the position of the bearing portion. On at least one surface side in the thickness direction, a pocket portion that is a molding material filling space is formed, and the surface that continues from the base end portion of the columnar body to the pocket portion is for promoting introduction of the molding material into the pocket portion. Or the slope of It is manufactured using an extrusion die that is formed into a curved surface, while the surface that continues from the pocket portion to the bearing portion is an inwardly convex curved surface. Multi-hole tube with a hollow part. 10. The fine multi-hole tube according to claim 9, wherein a reinforcing rib is formed so as to project from the tip end surface of the columnar body of the extrusion die. 11. The hollow portion has a width of 2.0 mm or less,
The wall thickness of the partition wall is 0.6 mm or less.
The fine multi-hole tube described in 0. 12. A protrusion is formed between adjacent partition walls in the hollow portion by forming a groove portion on at least one surface in the thickness direction of the columnar body in the bearing portion of the extrusion die. 12. The fine multi-hole tube according to any one of 1 to 11. 13. A female die for forming an outer peripheral portion of a pipe,
With a mandrel combined with this die female mold,
The mandrel has a main body and a plurality of columnar bodies protruding from the main body in a comb-like shape and arranged at intervals in the width direction, and the tip outer peripheral portion of the columnar bodies is arranged in the width direction of the pipe. A bearing portion that forms an inner peripheral surface of a plurality of hollow portions provided is provided, and on the rear side in the extrusion direction with respect to the bearing portion,
At least one outer surface in the thickness direction of the columnar body is recessed inward in the thickness direction with respect to the position of the bearing portion, so that at least one surface side in the thickness direction of the columnar body is a pocket portion that is a molding material filling space. And a surface continuing from the base end portion of the columnar body to the pocket portion is formed into an inclined surface or a curved surface for promoting introduction of the molding material into the pocket portion, while the pocket portion to the bearing portion are formed. A method for producing a heat exchange tube, characterized in that an extruding die having a curved surface with an inwardly convex curved surface is used, and a molding material is extruded from the extruding die. 14. The method of manufacturing a heat exchange tube according to claim 13, wherein a reinforcing rib is formed so as to project from the tip end surface of the columnar body of the extrusion die. 15. The width of the columnar body in the bearing portion of the extrusion die is 2.0 mm or less, and the distance between the bearing portions of adjacent columnar bodies is 0.6 mm or less.
The method for producing a heat exchange tube according to 3 or 14. 16. The method of manufacturing a heat exchange tube according to claim 13, wherein a groove is formed on at least one surface of the columnar body in the bearing portion of the extrusion die in the thickness direction. 17. A female die for forming an outer peripheral portion of a pipe,
An extrusion die comprising a mandrel combined with the die female die, wherein the mandrel comprises a main body, and a plurality of columnar bodies protruding from the main body in a comb shape and arranged at intervals in the width direction. And a tip outer peripheral portion of the columnar body is a bearing portion forming an inner peripheral surface of a plurality of hollow portions arranged in a row in the width direction of the pipe, and on the rear side in the extrusion direction with respect to the bearing portion, At least one outer surface in the thickness direction of the columnar body is recessed inward in the thickness direction with respect to the position of the bearing portion, so that at least one surface side in the thickness direction of the columnar body is a pocket portion that is a molding material filling space. And a surface continuing from the base end portion of the columnar body to the pocket portion is formed as an inclined surface or a curved surface for facilitating introduction of the molding material into the pocket portion. Manufactured by using an extrusion die in which the surface following the hollow part is formed as an inwardly convex curved surface, and a heat exchange tube having a large number of minute hollow parts partitioned by partition walls in the width direction. Exchanger. 18. The heat exchanger according to claim 17, wherein a reinforcing rib is formed so as to project from the tip end surface of the columnar body of the extrusion die. 19. The width of the hollow portion of the heat exchange tube is 2.0.
The heat exchanger according to claim 17 or 18, wherein the heat exchanger has a thickness of not more than mm and a partition wall having a thickness of not more than 0.6 mm. 20. The fin portion is formed so as to project between adjacent partition walls in the hollow portion of the heat exchange tube.
The heat exchanger according to any one of 7 to 19. 21. A female die for forming an outer peripheral portion of a pipe,
An extrusion die comprising a mandrel combined with the die female die, wherein the mandrel comprises a main body, and a plurality of columnar bodies protruding from the main body in a comb shape and arranged at intervals in the width direction. And a tip outer peripheral portion of the columnar body is a bearing portion forming an inner peripheral surface of a plurality of hollow portions arranged in a row in the width direction of the pipe, and on the rear side in the extrusion direction with respect to the bearing portion, At least one outer surface in the thickness direction of the columnar body is recessed inward in the thickness direction with respect to the position of the bearing portion, so that at least one surface side in the thickness direction of the columnar body is a pocket portion that is a molding material filling space. And a surface continuing from the base end portion of the columnar body to the pocket portion is formed as an inclined surface or a curved surface for facilitating introduction of the molding material into the pocket portion. A heat exchange tube having a large number of fine hollow portions partitioned by partition walls in the width direction is used, which is manufactured by using an extrusion die in which the surface following the hollow portion is formed as an inwardly convex curved surface. A method of manufacturing a heat exchanger in which heat exchange tubes and outer fins are alternately arranged and brazed. 22. The method of manufacturing a heat exchanger according to claim 21, wherein a reinforcing rib is formed so as to project from a tip end surface of the columnar body of the extrusion die. 23. The width of the hollow portion of the heat exchange tube is 2.0.
The heat exchanger manufacturing method according to claim 21 or 22, wherein the partition wall has a wall thickness of 0.6 mm or less, and a partition wall thickness of 0.6 mm or less. 24. The fin portion is formed so as to project between adjacent partition walls in the hollow portion of the heat exchange tube.
24. The method for manufacturing the heat exchanger according to any one of 1 to 23.