JP2021186862A - Heat exchanger manufacturing method - Google Patents

Abstract

To provide a heat exchanger manufacturing method that can manufacture a heat exchanger at low cost.SOLUTION: The heat exchanger manufacturing method includes a main jointing step in which only a stirring pin F2 of a rotating tool F that rotates is inserted into an outer peripheral surface 11f of at least one end part of an extrusion porous pipe 2 and is made to go around the outer peripheral surface 11f of the extrusion porous pipe 2 at a predetermined depth along an overlapping part J2 to friction-stir the overlapping part J2, while contacting only the stirring pin F2 with only the extrusion porous pipe 2 or with the extrusion porous pipe 2 and lid bodes 3. In the main jointing step, the extrusion porous pipe 2 and the lid bodies 3 are rotated or moved parallel using a pair of holding parts 32 and 32 to friction-stir the extrusion porous pipe 2 and at least one lid body 3, while making the holding parts 32 press and hold the two lid bodies 3 and the extrusion porous pipe 2 from both outsides of the lid bodies 3.SELECTED DRAWING: Figure 4

Description

The present invention relates to a method for manufacturing a heat exchanger.

A method of manufacturing a heat exchanger using friction stir welding is performed. For example, Patent Document 1 describes a method for manufacturing a heat exchanger in which an extruded porous tube in which a plurality of holes are arranged side by side and a sealing body that seals an opening of the extruded porous tube are joined by friction stir welding. It has been disclosed.

Japanese Unexamined Patent Publication No. 2016-74016

In the invention according to Patent Document 1, in order to rotate the rotary tool around the extruded porous tube with the rotary tool and the outer peripheral surface of the extruded porous tube perpendicular to each other, the rotary tool is driven to rotate, for example, a spindle unit or the like at the tip. It is necessary to change / adjust the angle and insertion position of the rotation center axis of the rotation tool by attaching it to an arm robot equipped with means. In addition, it is necessary to adjust so that the jig for positioning the extruded perforated pipe and the lid and the moving route of the rotating tool do not interfere with each other. For this reason, there is a problem that the work becomes complicated and ancillary equipment such as a device for driving the rotation tool is costly, resulting in high manufacturing cost.

From such a viewpoint, it is an object of the present invention to provide a method for manufacturing a heat exchanger, which can manufacture a heat exchanger at low cost.

In order to solve the above problems, the present invention is composed of an extruded perforated tube having fins inside and two lids for sealing the openings of the extruded perforated tube, and the extruded perforated tube and the lid. This is a method for manufacturing a heat exchanger in which the lids are joined by frictional stirring. The lid has a peripheral wall portion that rises from a bottom portion and a peripheral edge of the bottom portion, and the extruded porous tube has fins formed at both ends thereof. The rotary tool used for friction stirring has a fitting portion to which the peripheral wall portion is fitted, and the stirring pin is provided with a stirring pin, which is tapered toward the tip side and is extruded porous. By inserting the peripheral wall portion of one lid body into one of the fitting portions of the tube and inserting the peripheral wall portion of the other lid body into the other fitting portion of the extruded porous tube, the said. The inner peripheral surfaces of both ends of the extruded porous tube and the outer peripheral surface of the peripheral wall of each of the lids are overlapped to form two overlapping portions, and the extruded porous tube is one with the end surface of one fin. A butting step of forming two sets of butt portions by abutting the end face of the peripheral wall portion of the lid body and the end face of the other fin of the extruded porous tube with the end face of the peripheral wall portion of the other lid body. , Only the stirring pin of the rotating tool is inserted into the outer peripheral surface of at least one end of the extruded porous tube, and only the stirring pin is in contact with the extruded porous tube only or the extruded porous tube and the lid. In the main joining step, the main joining step of circling around the outer peripheral surface of the extruded porous tube at a predetermined depth along the polymerized portion and rubbing and stirring the polymerized portion is included. While pressing and holding the two lids and the extruded porous tube from both outer sides of each of the lids with a pair of holding portions, the extruded porous tube and the lid are rotated or parallel using the holding portions. It is characterized in that the extruded perforated tube and at least one of the lids are rubbed and stirred by moving the extruded perforated tube.

Further, the present invention is composed of an extruded porous pipe having fins inside and two lids for sealing the openings of the extruded porous pipe, and the extruded porous pipe and the lid are joined by friction stirring. In the method of manufacturing a heat exchanger, the lid has a bottom portion and a peripheral wall portion rising from the peripheral edge of the bottom portion, and a step bottom surface and a step side surface rising from the step bottom surface are formed on the outer peripheral edge of the peripheral wall portion. The extruded perforated pipe has a fitting portion in which the fins are not formed at both ends and the peripheral wall portion is fitted, and the rotary tool used for friction stirring is a stirring portion. The stirring pin is provided with a pin, and the stirring pin is tapered toward the tip end side. By inserting the peripheral wall portion of the other lid body into the other fitting portion of the pipe, the inner peripheral surfaces of both ends of the extruded porous pipe and the stepped side surface of each of the lid bodies are overlapped with each other. While forming two overlapping portions, one end surface of the extruded porous pipe and the step bottom surface of one lid body, and the other end surface of the extruded porous pipe and the step bottom surface of the other lid body are formed. In the butt step of forming two butt portions by butt-butting each, only the stirring pin of the rotating tool is inserted into the outer peripheral surface of at least one end of the extruded porous tube, and only the stirring pin is inserted into the extruded porous tube. A book that rubs and stirs the polymerized portion only or in contact with the extruded porous pipe and the lid by making a circumference around the outer peripheral surface of the extruded porous pipe at a predetermined depth along the polymerized portion. Including the joining step, in the main joining step, the holding portion is used while pressing and holding the two lids and the extruded perforated pipe from both outer sides of each lid with a pair of holding portions. The extruded porous tube and the lid are rotated or moved in parallel to rub and stir the extruded porous tube and at least one of the lids.

According to such a manufacturing method, since the extruded porous tube and the lid are rotated or translated while the lid is held by the pair of holding portions, the holding portion and the rotating tool do not interfere with each other during the main joining step. That is, the extruded perforated pipe and the jig for positioning the lid do not hinder the movement of the rotating tool. As a result, the insertion position and the like can be easily adjusted, and the cost of incidental equipment can be suppressed. Therefore, the heat exchanger can be manufactured at low cost. Further, by abutting the fins or end faces of the extruded perforated pipe with the peripheral wall portion of the lid, the positioning of the lid in the insertion direction can be easily performed.

Further, the extruded porous tube is formed of a second aluminum alloy, the lid is made of a first aluminum alloy, and the first aluminum alloy is a grade having a higher hardness than the second aluminum alloy. It is preferable to have.

Further, it is preferable that the first aluminum alloy is made of a cast material and the second aluminum alloy is made of a wrought material.

Further, in the main joining step, it is preferable that the tip of the stirring pin is made to go around the outer peripheral surface of the extruded perforated pipe in a state of being in contact with the peripheral wall portion of the lid body, and the polymerized portion is frictionally agitated. ..

According to such a manufacturing method, the joint strength between the lid and the extruded perforated pipe can be increased.

According to the present invention, it is possible to provide a method for manufacturing a heat exchanger, which can manufacture the heat exchanger at low cost.

It is an exploded perspective view which shows the heat exchanger which concerns on 1st Embodiment of this invention. It is sectional drawing which shows the butt process of the manufacturing method of the heat exchanger which concerns on 1st Embodiment. It is a perspective view which shows the main joining process of the manufacturing method of the heat exchanger which concerns on 1st Embodiment. It is a schematic diagram which shows the start position of the main joining process of the manufacturing method of the heat exchanger which concerns on 1st Embodiment. It is sectional drawing which shows the main joining process of the manufacturing method of the heat exchanger which concerns on 1st Embodiment. It is a schematic diagram which shows the end position of this joining process of the manufacturing method of the heat exchanger which concerns on 1st Embodiment. It is sectional drawing which shows the butt process of the manufacturing method of the heat exchanger which concerns on 2nd Embodiment of this invention. It is sectional drawing which shows this joining process of the manufacturing method of the heat exchanger which concerns on 2nd Embodiment of this invention.

[First Embodiment]
An embodiment of the present invention will be described with reference to the drawings as appropriate. The present invention is not limited to the following embodiments. In addition, some or all of the components in each embodiment can be combined as appropriate. As shown in FIG. 1, the heat exchanger 1 according to the first embodiment is composed of an extruded porous tube 2 and lids 3 (3A, 3B) arranged at both ends of the extruded porous tube 2. .. The heat exchanger 1 is a device that circulates a fluid inside to cool an arranged heating element. The extruded perforated pipe 2 and each lid 3 are integrated by friction stir welding. The lid 3 is referred to as a lid 3A and 3B as necessary to distinguish them.

The extruded perforated pipe 2 is mainly composed of a main body portion 11 and a plurality of fins 12. The fin 12 is formed inside the main body 11. In the present embodiment, the extruded porous tube 2 is formed mainly containing a second aluminum alloy. The second aluminum alloy is formed of, for example, an aluminum alloy wrought material such as JIS A1050, A1100, A6063. The extruded perforated pipe 2 is an extruded profile made of a second aluminum alloy.

The main body 11 has a tubular shape. The side portions 11a and 11b of the main body portion 11 are curved so as to be convex outward (outside in the width direction of the main body portion 11). The substrate portions 11c and 11d of the main body portion 11 are flat and face each other in parallel. That is, the cross section of the main body 11 has an oblong shape. The fins 12 are perpendicular to the substrate portions 11c and 11d. The fins 12 extend in the extrusion direction of the main body 11, and are formed in parallel with each other. A plurality of holes 13 having a rectangular cross section through which a fluid flows are formed between the adjacent fins 12.

Fitting portions 14 to which fins 12 are not formed are formed in the openings at both ends of the extruded porous tube 2. The fitting portion 14 is a portion into which the peripheral wall portion 22 of the lid 3, which will be described later, is inserted. The fitting portion 14 is formed by cutting both ends of the fin 12. The shape of the extruded perforated pipe 2 is not limited to the above-mentioned shape. For example, the cross section of the extruded porous tube 2 (cross section perpendicular to the extrusion direction) may be circular, elliptical, or square.

The lids 3A and 3B are members that seal the openings at both ends of the extruded porous tube 2. The lids 3A and 3B have the same shape, respectively. The lid 3 has a bottom portion 21 and a peripheral wall portion 22. The bottom portion 21 is a plate-shaped member having an oval shape. The outer shape of the bottom portion 21 is housed inside the extruded perforated pipe 2, and is formed with an inner peripheral surface 11 g (see FIG. 2) of the main body 11 of the extruded perforated pipe 2 so as to seal the opening of the extruded perforated pipe 2. It has almost the same shape. The peripheral wall portion 22 is a portion that rises vertically from the peripheral edge portion of the bottom portion 21. The peripheral wall portion 22 is formed in an oval frame shape along the shape of the bottom portion 21. A concave header flow path 24 is formed by the bottom portion 21 and the peripheral wall portion 22.

The material of the lid 3 is not particularly limited as long as it is a metal capable of friction stir welding, but in the present embodiment, it is formed mainly containing a first aluminum alloy. The first aluminum alloy is a material having a higher hardness than the second aluminum alloy. As the first aluminum alloy, for example, an aluminum alloy cast material such as JISH5302 ADC12 (Al—Si—Cu system) is used. In the present specification, the hardness refers to Brinell hardness, and can be measured by a method according to JIS Z 2243.

Next, a method of manufacturing the heat exchanger according to the present embodiment will be described. In the method for manufacturing a heat exchanger according to the present embodiment, a preparation step, a butt step, and a main joining step are performed.

The preparation step is a step of preparing the extruded porous tube 2 and the lid 3. The extruded porous tube 2 is formed by, for example, extrusion molding. The lid 3 is molded by die casting, for example.

The butt step is a step of butting the lid 3 against the extruded porous tube 2 as shown in FIG. In the butt step, the peripheral wall portion 22 of the lid 3 is inserted into the fitting portion 14 of the extruded perforated pipe 2 and fitted. As a result, the end surface 22a of the peripheral wall portion 22 and the end surface 12a of the plurality of fins 12 are abutted to form a plurality of abutment portions J1. Further, the inner peripheral surface 11g of the extruded porous tube 2 and the outer peripheral surface 22b of the peripheral wall portion 22 are overlapped to form the polymerization portion J2.

This joining step is a step of friction-stir welding the polymerized portion J2 using the rotary tool F (see FIG. 5). In this joining step, a holding step and a friction stir welding step are performed. In the holding step, as shown in FIG. 3, the lids 3A and 3B are pressed and held from both outer sides by a holding device (jig) provided with a pair of holding portions 32. In the present embodiment, an intermediate plate 31 is interposed between the holding portion 32 and the lid 3A, and between the holding portion 32 and the lid 3B, respectively. The holding portion 32 has a columnar shape, and its end faces come into surface contact with the intermediate plates 31 and 31, respectively. By providing the intermediate plate 31, the pressing force of the holding portion 32 can be dispersed to reliably hold the extruded perforated pipe 2 and the lids 3A and 3B. The intermediate plate 31 may be omitted.

The holding portion 32 of the holding device, the extruded perforated tube 2, and the lids 3A and 3B rotate or move in parallel in synchronization with each other. That is, in the holding device, the extruded perforated pipe 2 and the lids 3A and 3B are rotated in the circumferential direction while the lid 3A and the lid 3B are pressed and held by the holding portions 32 and 32, respectively, and up and down, left and right. And it can be moved linearly in the front-back direction.

As shown in FIG. 5, the rotation tool F includes a connecting portion F1 and a stirring pin F2. The rotary tool F is made of, for example, tool steel. The connecting portion F1 is a portion connected to the rotating shaft of the friction stir device (not shown). The connecting portion F1 has a columnar shape, and a screw hole (not shown) to which a bolt is fastened is formed.

The stirring pin F2 hangs down from the connecting portion F1 and is coaxial with the connecting portion F1. The stirring pin F2 is tapered as it is separated from the connecting portion F1. At the tip of the stirring pin F2, a flat flat surface F3 that is perpendicular to the rotation center axis Z is formed. A spiral groove is engraved on the outer peripheral surface of the stirring pin F2. In the present embodiment, in order to rotate the rotation tool F clockwise, the spiral groove is formed counterclockwise from the base end to the tip end. In other words, the spiral groove is formed counterclockwise when viewed from above when the spiral groove is traced from the base end to the tip end.

When the rotation tool F is rotated counterclockwise, it is preferable to form the spiral groove clockwise from the base end toward the tip end. In other words, the spiral groove in this case is formed clockwise when viewed from above when the spiral groove is traced from the base end to the tip end. By setting the spiral groove in this way, the metal plastically fluidized during friction stir welding is guided to the tip end side of the stirring pin F2 by the spiral groove. As a result, the amount of metal that overflows to the outside of the metal member to be joined (extruded porous tube 2 and lid 3) can be reduced. The rotation tool F may be attached to, for example, a friction stir device that can move in the vertical direction and the horizontal direction, or may be attached to an arm robot having a rotation driving means such as a spindle unit at the tip.

In the friction stir welding step, as shown in FIG. 4, the start position SP1, the end position EP1, and the intermediate points S1 and S2 are set apart from each other on the set movement route L1. The set movement route L1 is set in the vicinity of the end face 11e of the extruded perforated pipe 2 in parallel with the end face 11e.

As shown in FIG. 4, in the friction stir welding step, the intrusion section from the start position SP1 to the intermediate point S1, the main section from the intermediate point S1 on the set movement route L1 to the intermediate point S2, and the intermediate point S2. Three sections of the detachment section from to the end position EP1 are continuously subjected to friction stir welding. In the friction stir welding step, for example, when the rotary tool F is attached to the friction stir welder, the metal member to be joined is rotated or linearly moved by the holding portions 32 and 32 without moving the position of the rotary tool F to perform friction stir welding. I do. Further, for example, when the rotation tool F is attached to the arm robot, at least one of the holding device provided with the holding portions 32 and 32 and the arm robot is displaced to move the rotation tool F relative to the metal member to be joined. Perform friction stir welding.

In the closet section, friction stir welding is performed from the start position SP1 to the intermediate point S1. In the closet section, the stirring pin F2 rotated clockwise is inserted into the start position SP1 while the rotation center axis Z is perpendicular to the outer peripheral surface 11f of one end of the main body 11, and is relatively moved to the intermediate point S1. .. At this time, the stirring pin F2 is gradually pushed in so as to reach a preset "predetermined depth" by at least reaching the intermediate point S1. That is, instead of keeping the rotation tool F in one place, the rotation tool F is gradually lowered while being moved to the set movement route L1. A plasticized region W1 is formed in the movement locus of the rotation tool F.

When the rotation tool F reaches the intermediate point S1, the section shifts to this section as it is. The predetermined depth means the depth at which the stirring pin F2 is inserted in this section from the intermediate point S1 to the intermediate point S2. In this section, as shown in FIG. 5, only the stirring pin F2 of the rotation tool F is brought into contact with the metal member to be joined and is made to go around along the set movement route L1.

In the present embodiment, a predetermined depth is set so that the tip of the stirring pin F2 (flat surface F3) is in contact with the outer peripheral surface 22b of the peripheral wall portion 22. In this section, only the stirring pin F2 is inserted from the outer peripheral surface 11f side of the end portion of the extruded porous tube 2 to the overlapping portion J2, and only the stirring pin F2 is brought into contact with the extruded porous tube 2 and the lid 3A. The polymerized portion J2 is friction-stir welded with the base end side of the stirring pin F2 exposed. In this section, a predetermined depth may be set so that the stirring pin F2 does not come into contact with the lid 3A. That is, friction stir welding may be performed in a state where only the stirring pin F2 is in contact with only the extruded porous tube 2. In this case, the polymerized portion J2 is plastically fluidized and joined by the frictional heat between the stirring pin F2 and the extruded porous tube 2.

In this section, when the rotation tool F is viewed from above, the rotation tool F is moved so that the rotation center axis Z overlaps with the set movement route L1. As shown in FIG. 6, when the stirring pin F2 reaches the intermediate point S2 by rotating the rotation tool F around the rotation tool F, the rotation tool F shifts to the withdrawal section as it is.

In the detachment section, the stirring pin F2 is gradually pulled out (raised) from the intermediate point S2 toward the end position EP1, and the stirring pin F2 is detached from the extruded porous tube 2 at the end position EP1. That is, the rotation tool F is gradually pulled out while being moved to the end position EP1 without staying in one place.

After the friction stir welding between the extruded porous pipe 2 and the lid 3A on one end side is completed, the friction stir welding between the extruded porous pipe 2 and the lid 3B on the other end side is performed in the same manner. That is, the peripheral wall portion 22 of one lid 3A is inserted into one fitting portion 14 of the extruded porous pipe 2, and the peripheral wall portion of the other lid 3B is inserted into the other fitting portion of the extruded porous pipe 2. .. As a result, the inner peripheral surfaces of both ends of the extruded porous tube 2 and the outer peripheral surfaces of the peripheral wall portions 22 of the respective lids 3A and 3B are overlapped to form two overlapping portions J2 (partially not shown). Further, the end surface 12a of one fin 12 of the extruded porous tube 2, the end surface 22a of the peripheral wall portion 22 of the lid 3A, and the end surface of the other fin 12 of the extruded porous tube 2 and the end surface of the peripheral wall portion of the other lid 3B. And are butted against each other to form two sets of butted portions J1 at both ends of the fin 12 (partially not shown). Then, the two polymerization portions J2 are frictionally agitated. Friction stir welding between the extruded porous tube 2 and the lid 3B on the other end side may be omitted. That is, it is sufficient that the extruded porous tube 2 and at least one lid 3 are frictionally agitated.

According to the method for manufacturing a heat exchanger in the present embodiment described above, the extruded perforated pipe 2 and the lids 3A and 3B are rotated or linearly held in a state where the lids 3A and 3B are held from both outer sides by a pair of holding portions 32. Since it is moved, the holding portion 32 and the rotation tool F do not interfere with each other during the main joining process. That is, since the jig for positioning the extruded perforated pipe 2 and the lids 3A and 3B is not on the movement route of the rotation tool F, it does not hinder the movement of the rotation tool F. As a result, the insertion position and the like can be easily adjusted, and the cost of incidental equipment can be suppressed. Therefore, the heat exchanger 1 can be manufactured at low cost.

Further, in this joining step, the tip of the stirring pin F2 (flat surface F3) is set to a predetermined depth so as to come into contact with (penetrate) the outer peripheral surface 22b of the peripheral wall portion 22, so that the lid 3 and the lid 3 are formed. The bonding strength with the extruded porous tube 2 can be increased.

Further, in the butt step, the end surface 22a of the peripheral wall portion 22 is brought into contact with the fin 12 of the extruded perforated pipe 2, so that the insertion direction of the lid 3 (extrusion direction of the extruded perforated pipe 2) can be easily positioned. can.

Further, in the closet section of the main joining step, the stirring pin F2 is gradually pushed in until the predetermined depth is reached while moving the rotary tool F from the start position SP1 to the intermediate point S1 at one point on the set movement route L1. It is possible to prevent the rotation tool F from stopping and the frictional heat from becoming excessive.
Similarly, in the disengagement section of the main joining step, the stirring pin F2 is gradually pulled out from a predetermined depth while moving the rotation tool F from the intermediate point S2 to the end position EP1 to disengage the stirring pin F2 on the set movement route L1. It is possible to prevent the rotation tool F from stopping at one point and causing the frictional heat to become excessive.

As a result, it is possible to prevent the frictional heat from becoming excessive on the set movement route L1 and the first aluminum alloy from being excessively mixed into the extruded porous pipe 2 from the lid 3 to cause poor joining.

Further, the first aluminum alloy of the lid 3 is a material having a higher hardness than the second aluminum alloy of the extruded porous tube 2. Thereby, the durability of the heat exchanger 1 can be enhanced. Further, it is preferable that the first aluminum alloy of the lid 3 is an aluminum alloy cast material and the second aluminum alloy of the extruded porous tube 2 is an aluminum alloy wrought material. By using an Al—Si—Cu based aluminum alloy casting material such as JISH5302 ADC12 as the first aluminum alloy, the castability, strength, machinability and the like of the lid 3 can be improved. Further, by using, for example, JIS A1000 series or A6000 series as the second aluminum alloy, the processability and thermal conductivity of the extruded porous tube 2 can be improved.

Further, in this joining step, since the entire circumference of the butt portion J1 can be friction-stir welded, the airtightness and watertightness of the heat exchanger can be improved. Further, at the end portion of the main joining step, the rotation tool F is made to go to the end position EP1 after completely passing through the intermediate point S1. That is, the airtightness and watertightness can be further improved by overlapping the ends of the plasticized region W1 formed by this joining step on the set movement route L1.

Further, in this joining step, only the stirring pin F2 is brought into contact with the extruded porous tube 2 and the lid 3A, and friction stirring is performed with the base end side of the stirring pin F2 of the rotary tool F exposed. The acting load can be reduced. In this joining step, only the stirring pin F2 may be brought into contact with only the extruded porous tube 2, and friction stirring may be performed with the base end side of the stirring pin F2 of the rotary tool F exposed. Further, by providing the header flow path 24 in the lid 3, the fluid flowing in each hole 13 can be collected.

In this joining step, the rotation speed of the rotation tool F may be constant or variable. In the intrusion section of the main joining step, if the rotation speed of the rotation tool F at the start position SP1 is V1 and the rotation speed of the rotation tool F in this section is V2, V1> V2 may be satisfied. The rotation speed V2 is a preset constant rotation speed in the set movement route L1. That is, at the start position SP1, the rotation speed may be set high, and the rotation speed may be gradually reduced in the closet section to shift to the main section.

Further, if the rotation speed of the rotation tool F in this section is V2 and the rotation speed of the rotation tool F at the end position EP1 is V3 in the detachment section of the first main joining step, V3> V2 may be satisfied. That is, after shifting to the detachment section, the rotation tool F may be detached from the extruded porous tube 2 while gradually increasing the rotation speed toward the end position EP1. By setting as described above when the rotary tool F is pushed into the extruded perforated pipe 2 or when it is detached from the extruded perforated pipe 2, it is possible to compensate for the small pushing pressure in the indentation section or the incision section at the rotation speed. Therefore, friction stir welding can be preferably performed.

[Second Embodiment]
Next, a method for manufacturing the heat exchanger according to the second embodiment of the present invention will be described. In the second embodiment, as shown in FIGS. 7 and 8, the shape of the lid 3C is different from that of the first embodiment. In the second embodiment, the parts different from the first embodiment will be mainly described. In the manufacture of the heat exchanger according to the second embodiment, a preparation step, a butt step, and a main joining step are performed.

In the preparation step, the extruded perforated pipe 2 and the lid 3C are prepared. The lid 3C has a bottom portion 21 and a peripheral wall portion 22C rising from the peripheral edge of the bottom portion 21. A peripheral wall step portion 23 is formed on the outer peripheral edge of the peripheral wall portion 22C over the entire circumferential direction. The peripheral wall step portion 23 has a step bottom surface 23a and a step side surface 23b that rises vertically from the step bottom surface 23a. The step bottom surface 23a is parallel to the bottom portion 21.

In the butt step, the peripheral wall portion 22C of the lid 3C is inserted into the fitting portion 14 of the extruded perforated pipe 2 and fitted. As a result, the step bottom surface 23a of the peripheral wall portion 22C and the end surface 11e of the extruded perforated pipe 2 are abutted to form a butt portion J3 (two butt portions J3 are formed at both ends of the extruded perforated pipe 2). Further, the inner peripheral surface 11g of the extruded porous tube 2 and the stepped side surface 23b of the peripheral wall portion 22C are overlapped to form the polymerized portion J4 (two polymerized portions J4 are formed at both ends of the extruded porous tube 2). .. The fin 12 and the end surface 22a of the peripheral wall portion 22C may be in contact with each other or may be separated from each other.

In this joining step, as shown in FIG. 8, the polymerized portion J4 is friction-stir welded using the rotary tool F. In this section of the main joining process, a predetermined depth is set so that the tip of the stirring pin F2 (flat surface F3) comes into contact with the peripheral wall portion 22C (step side surface 23b). Since this joining step is substantially the same as that of the first embodiment, the description thereof will be omitted.

The method for manufacturing the heat exchanger according to the second embodiment described above can also obtain substantially the same effect as that of the first embodiment. Further, in the butt step, the step bottom surface 23a of the lid 3C is brought into contact with the end surface 11e of the extruded perforated pipe 2, so that the insertion direction of the lid 3C (extrusion direction of the extruded perforated pipe 2) can be easily positioned. Can be done.

Although the embodiment of the present invention has been described above, the design can be appropriately changed as long as it does not contradict the gist of the present invention. For example, in the main joining step according to the present embodiment described above, the start position SP1 and the end position EP1 are provided on the set movement route L1, but the start position SP1 and the end position EP1 are provided at a position away from the lid 3 with respect to the set movement route L1. The position SP1 and the end position EP1 may be provided. Also in this case, the rotation tool F is gradually pushed in while moving the rotation tool F from the start position SP1 to the intermediate point S1 provided on the set movement route L1. Further, the rotation tool F is gradually released while moving the rotation tool F from the intermediate point S2 to the end position EP1. This makes it possible to prevent excessive frictional heat on the set movement route L1. Further, when moving the rotation tool F to the intermediate point S1 side or separating it from the intermediate point S2, it is preferable to set a movement route so that the movement speed of the rotation tool F does not decrease or stop.

1 Heat exchanger 2 Extruded perforated pipe 3 Lid 22 Peripheral wall 32 Holding part F Rotating tool F2 Stirring pin J1 Butt part J2 Overlapping part SP1 Start position EP1 End position W1 Plasticization area

Claims (5)

Manufacture of a heat exchanger composed of an extruded porous tube having fins inside and two lids for sealing the openings of the extruded porous tube, and joining the extruded porous tube and the lid by frictional stirring. It ’s a method,
The lid has a bottom portion and a peripheral wall portion rising from the peripheral edge of the bottom portion.
The extruded perforated pipe has a fitting portion in which the fins are not formed at both ends and the peripheral wall portion is fitted.
The rotary tool used for friction stirring is equipped with a stirring pin, and the stirring pin is tapered toward the tip side.
Inserting the peripheral wall portion of one lid into the fitting portion of one of the extruded porous pipes, and inserting the peripheral wall portion of the other lid into the fitting portion of the other of the extruded porous pipes. By superimposing the inner peripheral surfaces of both end portions of the extruded porous pipe and the outer peripheral surfaces of the peripheral wall portions of the respective lids to form two overlapping portions, the end surface of one fin of the extruded porous pipe is formed. The end face of the peripheral wall portion of the lid body and the end face of the other fin of the extruded porous tube are abutted against each other to form two sets of abutting portions. Butting process and
Only the stirring pin of the rotating tool is inserted into the outer peripheral surface of at least one end of the extruded porous tube, and only the stirring pin is brought into contact with the extruded porous tube only or the extruded porous tube and the lid. In this state, the present joining step of circling around the outer peripheral surface of the extruded porous pipe at a predetermined depth along the polymerized portion and frictionally stirring the polymerized portion is included.
In the main joining step, the two lids and the extruded porous pipe are pressed and held by a pair of holding portions from both outer sides of the lids, and the extruded porous pipe and the extruded porous pipe are held by using the holding portions. A method for manufacturing a heat exchanger, which comprises rotating or moving a lid in parallel to rub and agitate the extruded perforated tube and at least one of the lids. Manufacture of a heat exchanger composed of an extruded porous tube having fins inside and two lids for sealing the openings of the extruded porous tube, and joining the extruded porous tube and the lid by frictional stirring. It ’s a method,
The lid has a peripheral wall portion rising from the bottom portion and the peripheral edge of the bottom portion, and a peripheral wall step portion having a step bottom surface and a step side surface rising from the step bottom surface is formed on the outer peripheral edge of the peripheral wall portion.
The extruded perforated pipe has a fitting portion in which the fins are not formed at both ends and the peripheral wall portion is fitted.
The rotary tool used for friction stirring is equipped with a stirring pin, and the stirring pin is tapered toward the tip side.
Inserting the peripheral wall portion of one lid into the fitting portion of one of the extruded porous pipes, and inserting the peripheral wall portion of the other lid into the fitting portion of the other of the extruded porous pipes. By superimposing the inner peripheral surfaces of both ends of the extruded porous pipe and the stepped side surfaces of the respective lids to form two overlapping portions, one end surface of the extruded porous pipe and one of the lids are formed. A butt step of forming two butt portions by abutting the step bottom surface of the body and the other end surface of the extruded porous tube with the step bottom surface of the other lid body.
Only the stirring pin of the rotating tool is inserted into the outer peripheral surface of at least one end of the extruded porous tube, and only the stirring pin is brought into contact with the extruded porous tube only or the extruded porous tube and the lid. In this state, the present joining step of circling around the outer peripheral surface of the extruded porous pipe at a predetermined depth along the polymerized portion and frictionally stirring the polymerized portion is included.
In the main joining step, the two lids and the extruded porous pipe are pressed and held by a pair of holding portions from both outer sides of the lids, and the extruded porous pipe and the extruded porous pipe are held by using the holding portions. A method for manufacturing a heat exchanger, which comprises rotating or moving a lid in parallel to rub and agitate the extruded perforated tube and at least one of the lids. The extruded porous tube is made of a second aluminum alloy, the lid is made of a first aluminum alloy, and the first aluminum alloy is a grade having a higher hardness than the second aluminum alloy. The method for manufacturing a heat exchanger according to claim 1 or 2, wherein the heat exchanger is manufactured according to claim 1. The method for manufacturing a heat exchanger according to claim 3, wherein the first aluminum alloy is made of a cast material and the second aluminum alloy is made of a wrought material. The main joining step is characterized in that the tip of the stirring pin is made to go around the outer peripheral surface of the extruded porous pipe in a state of being in contact with the peripheral wall portion of the lid body, and the polymerized portion is frictionally agitated. The method for manufacturing a heat exchanger according to any one of claims 1 to 4.

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