JPH0615390A - Manufacturing method of brazing metal pipe having guide piece in tube insertion hole - Google Patents

Abstract

(57) [Abstract] [Purpose] A brazing metal pipe having a guide piece protruding in parallel with the tube is formed on at least one side edge of the oval tube insertion hole in the minor axis direction to form a complex-shaped hole. A mold is not required so that the pipe wall can be manufactured without being crushed or deformed. [Structure] A strip-shaped forming plate (30) is provided with a pilot hole (31) having a shape corresponding to a tube insertion hole in a state where a guide piece forming projection (32) is left on a side edge in the minor axis direction. In the aspect in which the pilot hole (31) is located on the arc surface, a part of the band-shaped forming blank (30) in the width direction or the length direction is bent and formed in an arc cross section to form the arc portion (39). . By performing a burring process on the lower hole (31), the guide piece forming projection (32) is projected in the thickness direction to form the guide piece (7). The non-circular arc portion (40) excluding the circular arc portion (39) is bent and molded into a pipe having a side-to-side abutting shape.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a brazing metal pipe made of aluminum (including its alloy) or the like, and in particular heat exchange for a car air conditioner condenser, radiator, evaporator, etc. manufactured by brazing specifications. The present invention relates to a method for manufacturing a brazing metal pipe having a guide piece in a tube insertion hole, which is preferably used as a header pipe of a container.

[0002]

2. Description of the Related Art For example, as a heat exchanger as described above,
As shown in FIG. 2, a plurality of flat tubes having an oval cross section are arranged in parallel in a pair of hollow header pipes (3) and (4) arranged in parallel, and the header pipes are There is a so-called parallel flow type heat exchanger in which the fins (2) are connected to each other and are connected between the adjacent tubes (1) and (1).

As the above header pipes (3) and (4) of such a heat exchanger, generally, a brazing sheet in which a brazing material layer is clad on one or both sides of a core material is formed into a pipe shape, and the length direction of the pipe is measured. In addition, a plurality of oval tube insertion holes that match the cross-sectional shape of the tube are arranged in a row. Then, the tube (1) is inserted into the tube insertion holes of the header pipes (3) and (4) and brazed to join the header pipes (3) and (4) to the tube (1). Has been made.

Conventionally, the header pipe as described above has been manufactured by perforating an electric resistance welded pipe of a brazing sheet to form a tube insertion hole. As a result, the pipe is likely to be crushed or deformed.

Therefore, in order to solve the above-mentioned drawbacks, the present applicant bends and forms a part in the width direction or the length direction of a strip-shaped forming blank made of a brazing sheet into an arc-shaped cross section, and then forms the arc-shaped portion into the arc-shaped portion. A method for manufacturing a brazing pipe is proposed in which a tube insertion hole is formed by carrying out a hole forming process, and then both side edges of a forming raw plate are made into an abutting shape to form a pipe for brazing (Japanese Patent Publication No. 3-18982). ).

[0006] According to this method, it is possible to carry out the drilling from the one side of the arc portion with the pad die having a shape matching the arc portion applied, and it is possible to eliminate crushing and deformation of the pipe wall and to achieve high dimensional accuracy. It had the expected excellent effect of being a pipe.

However, in the above-described method for manufacturing a brazing metal pipe, when the tube insertion hole has a simple shape such as an ellipse, the advantages thereof can be maximized. As described above, there are cases where it is necessary to drill holes having a non-simple shape, and in this case, the following new problems were created.

[0008]

That is, in recent years, it has been attempted to facilitate and smooth the insertion of a tube into a tube insertion hole provided in a header pipe, to eliminate wobbling after insertion, and For the purpose of increasing the joint area and the like, as shown in FIG. 1, at least one side edge of the oval tube insertion hole (5) in the minor axis direction projects in parallel with the insertion tube (1). Providing guide pieces (7) has become commonplace.

Thus, in order to form such a guide piece (7), the guide piece is formed at the prepared hole having the shape shown in FIG. 14, that is, at the side edge in the minor axis direction of the oval shape. After first forming the pilot hole (31) with the protruding portion (32) left,
Burr processing is applied to this pilot hole (31) to form a protrusion (32).
Must be projected in the thickness direction to form a guide piece.

However, if a part of the band-shaped forming blank is bent and formed into an arcuate section and then the pilot hole is opened,
It is necessary to use a three-dimensional hole type that has a blade part that matches the prepared hole shape in bottom view and an arc surface in side view, which complicates the manufacturing process of the hole type and increases the cost. It was a new problem that was prone to damage and wear of the blade.

The present invention has been made in view of the above technical background, and has an oval tube insertion hole,
In addition, a brazing metal pipe having a guide piece protruding in parallel with the insertion tube is provided on at least one side edge of the tube insertion hole in the minor axis direction, and a piercing die having a complicated shape is unnecessary, and the pipe wall is crushed. The present invention aims to enable production without causing deformation or deformation, and provides a production method therefor.

[0012]

In order to achieve the above object, the first aspect of the present invention has an oval tube insertion hole (5) as shown with reference to the drawings. A method for manufacturing a brazing metal pipe having a guide piece (7) projecting parallel to the insertion tube (1) on at least one side edge of the tube insertion hole (5) in the minor axis direction. , The brazing material layer (30b) on at least one side of the core material (30a).
) Is attached to the strip-shaped blank (30) made of a brazing sheet, and the pilot hole (31) corresponding to the tube insertion hole is formed.
In the state where the guide piece forming protrusions (32) are left on the side edges in the minor axis direction, and the pilot hole (31) is located on the arc surface. A part of (30) in the width direction or length direction is bent and formed into an arc shape in cross section, and the arc part (3
9) is formed, and after the bending, the pilot hole (31) is subjected to burring so that the guide piece forming projection (32) is projected in the thickness direction to form the guide piece (7). Forming step and, after forming the guide piece, bending-forming the non-circular arc portions (40) (40) excluding the circular arc portion (39) of the forming blank plate (30) to form a pipe having both side edge butting shapes The gist of the present invention is to provide a method for manufacturing a brazing metal pipe having a guide piece in a tube insertion hole, which includes:

Further, the above-described manufacturing process, including the process for forming the strip-shaped blank, is carried out continuously while intermittently transferring one long brazing sheet in the length direction. desirable. That is, the second aspect of the present invention has an oval tube insertion hole (5), and is parallel to the insertion tube (1) on at least one side edge of the tube insertion hole in the minor axis direction. A method for manufacturing a brazing metal pipe having a guide piece (7) projecting in the shape of a brazing sheet (50) in which a brazing material layer (30b) is attached to at least one surface of a core material (30a). The strip-shaped forming blank (30) whose both ends in the length direction or the width direction are connected to the extra support piece (52) on the outer side through the connecting strips (51) by removing the strip-shaped forming plate (30). In the brazing sheet (50) or strip-shaped blank (30), the pilot hole (31) corresponding to the tube insertion hole and the guide piece forming projection (32) on the side edge in the minor axis direction are left. In the step of drilling and in a mode in which the lower hole (31) is located on the arc surface, the strip-shaped blank (3
(0) a step of forming a circular arc portion (39) by bending a part of the width direction or the length direction in a circular arc cross section, and after the bending forming, burring the lower hole (31), A step of forming the guide piece (7) by projecting the guide piece forming projection (32) in the thickness direction, and a non-excluding arc portion (39) of the forming blank (30) after the guide piece is formed. Arc part (4
0) (40) is formed by bending to form a side-to-side edge-butting shape, thereby forming a pipe connected to the excess support piece (52) through the connecting strip (51) and the excess support of the pipe. Including a step of separating from the piece (52), each step from the step of forming the strip-shaped forming blank (30) to the pipe separating step,
A method for manufacturing a brazing metal pipe having a guide piece in a tube insertion hole is characterized in that it is carried out continuously while intermittently transferring one long brazing sheet (50) in the longitudinal direction. To do.

Further, preferably, before bending and forming the arcuate portion (39) of the strip-shaped blank (30), the inner edges of both ends of the pilot hole (31) in the major axis direction are pressed and deformed. Part
While forming a tapered part (33) that is positioned parallel to the tube insertion direction in the pipe molded state, the outer edges of both ends of the pilot hole in the major axis direction are thick in the pipe molded state in the tube insertion direction. It is preferable to form it in the vertical shearing part (34) that is inclined to the outside in the middle of.

[0015]

[Operation] A strip-shaped forming plate (30) is provided with a pilot hole (31) having a shape corresponding to a tube insertion hole with a guide piece forming projection (32) left on a side edge in the minor axis direction. After that, a part of the strip-shaped forming blank (30) in the width direction or the length direction is bent to have an arc-shaped cross section in a manner that the pilot hole (31) is located on the arc surface. ), A complicated perforating die as in the case of drilling is required. Moreover, since the pilot hole (31) is drilled at the stage of the band-shaped blank (30) before bending, there is no risk of crushing or deforming the pipe.

Further, each step from the step of forming the strip-shaped blank (30) to the step of separating the pipe is continuously performed while intermittently transferring one long brazing sheet (50) in the length direction. In this case, the brazing metal pipe with the guide piece is continuously and efficiently produced.

Further, before bending the forming blank (30), the inner edge portions of both ends of the pilot hole (31) in the major axis direction are positioned in parallel with the tube insertion direction in the pipe forming state ( Vertical shearing part (34) which, while forming in 33), inclines the outer edges of both ends of the pilot hole (31) in the major axis direction in a pipe-formed state toward the tube insertion direction to the middle of the wall thickness so as to open outward.
Header pipe (3)
When inserting both ends of the tube (1) into the tube insertion hole (5) of (4), the widthwise both ends of the tube are guided to the guide surfaces (34 ') at both ends of the insertion hole where the vertical shearing parts (34) are changed. Then, the tube (1) is smoothly inserted while being restricted by the parallel portions (33 ′) at both ends of the insertion hole where the tapered portion (33) is changed.

[0018]

Embodiments of the present invention will be described below. This example shows a method for manufacturing a header pipe used in a heat exchanger made of aluminum (including its alloy) as a car cooler capacitor shown in FIGS. 1 to 5.

1 to 5, (1) is a plurality of tubes vertically arranged in a horizontal state, (2) is a corrugated fin interposed between adjacent tubes (1) and (1), 3) and 4) are left and right aluminum header pipes having a circular cross section, and the brazing pipes manufactured by the present invention are used as these header pipes.

The header pipes (3) and (4) are manufactured as follows.

That is, first, as shown in FIGS. 10 and 11, there is prepared a strip-shaped blank (30) in which a brazing material layer (30b) is formed on both surfaces of a core material (30a) made of aluminum. As the brazing material layer (30b), an Al-Si alloy having a Si content of about 6 to 13 wt% is generally used.

Then, as shown in FIG. 12, in the widthwise intermediate portion of the forming blank (30), a prepared hole (31) having a major axis direction coinciding with the width direction of the forming blank is formed. 30)
Perforated at equal intervals in the length direction. This pilot hole (31)
In the future, the tube insertion hole (5) will have an oval shape. However, in order to form the guide pieces (7) on both side edges of the tube insertion hole (5) in the minor axis direction, the pilot hole (31 ) Is drilled in such a manner that guide piece forming projections (32) are left on both side edges in the minor axis direction.

By performing the above-described pre-hole punching process on the band-shaped forming blank plate (30) before bending, the two-dimensional shape of the punch type matches the pre-hole shape in plan view and is flat in side view. A shape can be used, and it is not necessary to use a three-dimensional shape having an arcuate shape in side view.

The pilot hole (31) is punched so as to penetrate straight through the thickness of the strip-shaped blank (30). After the perforation, preferably, one end edge portion in the thickness direction at both ends in the major axis direction of the pilot hole (31) is pressed and deformed to be faced, and as shown in FIG. A taper portion (33) is formed so as to incline. This taper (33)
In the pipe-formed state, the pipes are positioned parallel to the tube insertion direction as shown in FIG. 6, so that the outer peripheral surfaces of both ends in the width direction of the tube (1) are fitted into a surface contact state when the tube is inserted, and It is provided in order to prevent a gap from being formed between the insertion tube and the brazing and to allow sufficient brazing. Therefore, the taper part (3
In 3), the inclination angle is set in advance so that it becomes parallel to the tube insertion direction after pipe molding.

On the other hand, as shown in FIG. 13, the vertical shearing portions (34) straightly cut in the thickness direction remain at the other ends in the thickness direction at both ends in the major axis direction of the pilot hole (31). . This vertical shearing part (34) is shown in FIG.
As shown in (1), the tube (1) is inclined so as to open outward to the middle of the wall thickness, and serves as a guide surface when inserting the tube, which contributes to smoothing and facilitating the insertion.

Next, both widthwise edges of the strip-shaped blank (30) are pressed in the thickness direction with a press or the like to be faced. This pressurization is performed on the lower surface for one side edge portion and on the upper surface for the other side edge portion.
As shown in, the inclined surface (35a) is gradually thinned from the lower edge to the upper edge, and the other side edge portion is gradually thinned from the upper edge to the lower edge. Imposition on 35b). Moreover, the brazing material layer (30b) is present on each of the inclined surfaces (35a) (35b). By imposing both side edges of the strip-shaped forming plate (30) in this way, when the both side edges are made into an abutting shape as shown in FIG. 3, the abutting section (36) becomes an overlapping shape. A brazing material layer can be interposed on the abutting surface in conformity with each other, and sufficient brazing of the abutting portion (36) can be ensured by subsequent brazing.

Next, as shown in FIG. 14, after forming a refrigerant inlet / outlet pipe connection hole (37) at a predetermined portion, a plurality of strip-shaped forming blanks (30) are successively formed at the same position on both side edges in the width direction. Make notches (35). After the abutment, the notches (35) correspond to each other, but they are matched with each other, and a partition plate insertion hole for installing the partition plate (6) for the meandering circulation of the refrigerant in the heat exchanger shown in FIG. (11) will be formed.

Next, as shown in FIG. 16, the widthwise middle portion of the forming blank (30) including the formation area of the pilot hole (31) is bent along the lengthwise direction by pressing or the like into an arcuate cross section. Then, a circular arc portion (39) is formed so that the whole has a hat-shaped cross section. Then, as shown in FIG. 17, the horizontal non-circular arc portions (40) (40) on both sides of the arcuate portion are pressed in the closing direction to bend and form the whole into a substantially V-shaped section. The arc part (39) is formed by
The bending direction is determined so that the taper portions (33) at the both edges in the major axis direction of 1) are located inside and the vertical shearing portions (34) are located outside. By this bending, the tapered parts (33) at both ends of the pilot hole (31) in the major axis direction become parallel to the tube insertion direction,
The vertical shearing portion (34) serves as a guide surface (34 ') that is open to the outside (see FIG. 7).

Next, as shown in FIG. 18, the guide hole (31) is subjected to burring so that the guide piece forming protrusion (32) is deformed so as to project inward in the thickness direction. 7) is formed. The burring process may be performed by inserting a punch from the outside into the pilot hole (31) as in the known method. By this burring process, tube insertion holes (5) having guide pieces (7) projecting inward in the tube insertion direction are formed on both side edges in the minor axis direction.

Subsequently, the non-circular arc portions (40) (40) are further pressed in the approaching direction to bend and form the whole into a substantially U-shaped section (FIG. 19), and then the non-circular arc portions (40) are continuously curved. (39) is bent and formed into a circular cross section, and is formed into a header pipe in which both edges are butted against each other (FIG. 20).

After that, preferably, the cross-sectional shape of the pipe including the shape of the guide piece (7) is modified to obtain the header pipes (3) and (4) having desired dimensions.

By the way, in manufacturing the header pipe as described above, it goes without saying that a plurality of strip-shaped blanks (30) are first manufactured and the above-mentioned steps are carried out on each strip-shaped blank (30). Good, but production efficiency is to continuously carry out all the processes including the manufacturing process of the strip-shaped blank (30) while intermittently transferring one long brazing sheet (50) in the length direction. From the point of, it is particularly preferable.

That is, as shown in FIG. 21, by punching out an unnecessary portion at the tip of the long brazing sheet (50) in the lengthwise direction, a strip-shaped forming plate (30) long in the widthwise direction of the brazing sheet is formed. It is manufactured by connecting both ends in the length direction to the outer excess support piece (52) through the connecting strip (51). Incidentally, (53) is a feed hole provided in the surplus support piece (52) at a position lateral to the connecting strip (51).

Next, this brazing sheet (50) is
After being moved by a predetermined amount in the forward direction and stopped, as shown in FIG. 22, the formed band-shaped forming plate (30) is provided with a pilot hole (31) for a tube insertion hole, and at the same time, the leading band-forming forming plate. The following new band-shaped forming blank (30) is formed behind (30).

Next, the brazing sheet (50) is again conveyed by a predetermined amount and then stopped, and the leading band-shaped forming plate (30) is stopped.
The taper part (33) is formed in the pilot hole (31) for the second strip-shaped forming blank (30), and the pilot hole (31) is formed in the second strip-shaped blank (30) for the second strip-shaped blank (30). A third new band-shaped forming blank (30) is formed on the rear side, and the brazing sheet (20) is intermittently transferred in the same procedure as described below while performing each step on the forming blank (30) and adding a new one. Formed blank (30)
Are continuously formed. The order of performing the step of forming the strip-shaped blank (30) and the step of punching the pilot hole may be changed. First, the pilot hole (31) is drilled in the brazing sheet (50), or the pilot hole is further drilled. Tapers (3
After forming 3), unnecessary portions may be removed to form the strip-shaped blank (30).

In this case, however, each step of the strip-shaped forming plate (30) is carried out while being connected to the surplus supporting piece (52) through the connecting strip (51). When the molding step is completed, as shown in FIG. 23, the pipe molded body (41) still connected to the surplus support piece (52).
Is obtained.

Then, in the final step, the pipe molded body (41) is cut and separated from the connecting strip (51) to obtain a desired header pipe.

The header pipe thus manufactured is washed as needed and then sent to the product assembling process. Since this header pipe will be brazed after that,
The abutting portion is inevitably joined in the brazing process, and therefore the abutting portion (36) does not need to be closed by welding like an electric resistance welded pipe.

The heat exchanger shown in FIGS. 1 to 4 is manufactured as follows. That is, the header pipe (3) (4)
Insert both ends of the tube (1) into the tube insertion hole (5). When inserting the tube (1), both widthwise ends of the tube are guided by the guide surfaces (34 ') at both ends of the tube insertion hole (5) as shown in Figs. It is regulated by the part (33 ') and smoothly inserted, and after insertion, the guide piece (7) of the insertion hole.
Guided by, the tube (1) is inserted straight. Moreover, after being inserted, the guide piece (7) is firmly guided and there is almost no wobbling in the height direction of the tube (1), and the header pipes (3) (4) and the tube (1) form a right angle and are temporarily Connected.

After the tubes are inserted, the corrugated fins (2) also made of a brazing sheet are arranged between the adjacent tubes (1) and (1) and outside the outermost tubes in an intervening state, and the pipe partition plate insertion hole is provided. After inserting the partition plate (6) into (11) and arranging the upper and lower side plates (12) and (12) outside the outermost corrugated fins and temporarily assembling, these components are brazed in the furnace. Brazing all at once.

After brazing, a sufficient fillet is formed at the connecting portion between the header pipes (3) and (4) and the tube (1), and the header pipe and the tube are firmly joined and integrated without a gap. Becomes In particular, the outer opening guide surfaces (34 ') at both ends of the insertion hole serve as a wax reservoir and the wax flows in, and the guide piece (7) and the tube (1)
The abutment with and is widely brazed to ensure a stronger bond. In addition, fillets are also formed at the abutting portions (36) of the header pipes (3) and (4), and the abutting portions (36) are hermetically joined. Moreover, since the header pipes (3) and (4) are deformed under pressure at both side edges in the width direction of the band-shaped forming blank plate (30) at the manufacturing stage, the header pipes (3) and (4) are crushed into a continuous thin state. As shown in FIG. 3, since the abutting portion (36) matches the overlapping state and the brazing material layer (30b) is present between the abutting surfaces, the abutting portion (36) can be joined more reliably. Can be fully guaranteed. Note that (8) and (8) shown in FIG. 2 are upper and lower lid pieces of the header pipes (3) and (4), respectively, and these lid pieces are formed into a cap shape as shown in FIG. By covering the end portions of the header pipes after the pipes (3) and (4) are molded and before brazing, the pipes are closed and the header pipes are prevented from opening due to thermal deformation when the brazing heat is applied. It also has a role. Further, (9) shown in FIG. 2 is a refrigerant inlet pipe, (10) is the same outlet pipe, and these inlet and outlet pipes are brazed together like other parts.

In the above embodiment, the case where the tube insertion hole (5) whose major axis direction coincides with the width direction of the strip-shaped blank (30) is provided has been described. It is also possible to provide an insertion hole that matches the length direction of (1).

[0043]

According to the invention described in claim 1, there is an oval tube insertion hole, and at least one side edge of the tube insertion hole in the minor axis direction is parallel to the insertion tube. When manufacturing a brazing metal pipe having a projecting guide piece, after forming a pilot hole in the strip-shaped forming plate with a guide piece forming protrusion on the side edge in the minor axis direction, the pilot hole Since a part of the strip-shaped forming plate in the width direction or the length direction is bent and formed in an arc cross-section in a state of being located on the arc surface, a complicated piercing die such as a case where a pilot hole is formed after the bending is formed. It is not necessary, and it is possible to reduce the complexity of drilling-type processing and manufacturing, and the risk of blade damage and wear. Moreover, since the pilot hole is formed before bending, the risk of crushing or deforming the pipe can be reduced.

Further, since the burring process for forming the guide piece is performed in the arc portion after the bending, the guide piece prevents the guide piece from bending as in the case where the guide portion is bent. As a result, smooth bending can be performed without further functioning, and the risk of pipe deformation can be further reduced.

According to the second aspect of the present invention, one long brazing sheet is intermittently transferred in the length direction in each of the steps from the step of forming the strip-shaped forming plate to the step of separating the pipe. However, since it is continuously performed, the brazing metal pipe with the guide piece can be continuously and efficiently produced, and also can be produced by full automation.

According to the third aspect of the present invention, the inner edge portions of both ends of the pilot hole in the major axis direction are formed with tapered portions for arranging them in parallel with the tube insertion direction in the pipe-formed state, In addition, by forming the outer edges of both ends of the pilot hole in the major axis direction into vertical shearing parts that incline in an outwardly open shape up to the middle of the wall thickness with respect to the tube insertion direction in the pipe molded state, the tube insertion hole of the header pipe When inserting both ends of the tube into the tube, both ends in the width direction of the tube are guided by the guide surfaces at both ends of the tube insertion hole where the vertical shearing portion is changed, and are further restricted to the parallel portions at both ends of the insertion hole where the taper portion is changed. Therefore, the tube can be smoothly inserted into the insertion hole, and the brazing pipe can be easily assembled into a heat exchanger or the like.

[Brief description of drawings]

FIG. 1 is a perspective view of a heat exchanger using a brazing pipe manufactured according to the present invention as a header pipe, showing the header pipe and a tube separately.

2 (a) is a front view of the heat exchanger shown in FIG. 1,
Similarly, (B) is a plan view.

FIG. 3 is a sectional view taken along line III-III in FIG.

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

5 is a cross-sectional view taken along the line VV of FIG.

FIG. 6 is a vertical cross-sectional view of a brazing pipe manufactured according to the present invention.

7 is a sectional view taken along line VII-VII of FIG.

FIG. 8 is a front view of the brazing pipe.

FIG. 9 is a rear view of the same.

FIG. 10 is a perspective view of a band-shaped forming blank as a material of a brazing pipe.

11 is a sectional view taken along line XI-XI of FIG.

FIG. 12 is a perspective view showing a state where a pilot hole is formed in a strip-shaped blank.

13 is a sectional view taken along line XIII-XIII in FIG.

FIG. 14 is a cross-sectional view showing a state in which both side edges in the width direction of the band-shaped forming blank are faced.

FIG. 15 is a plan view showing a state where a notch for inserting a partition plate and a refrigerant inlet / outlet pipe connection hole are provided in a forming blank plate.

FIG. 16 is a perspective view after forming an arc portion.

FIG. 17 is a cross-sectional view after V-shaped bending.

FIG. 18A is a sectional view after forming a guide piece by burring, and FIG. 18B is a sectional view taken along line XVIII-XVIII of FIG. 18A.

FIG. 19 is a cross-sectional view after U-shaped bending.

FIG. 20 is a cross-sectional view after molding into a pipe.

FIG. 21 is a perspective view showing a state where a leading strip-shaped blank is formed on one long brazing sheet.

FIG. 22 is a perspective view after the brazing sheet of FIG. 21 is transferred and the next step is performed.

FIG. 23 is a perspective view before performing a pipe separating step.

[Explanation of symbols]

 1 ... Tube 3, 4 ... Header 5 ... Tube insertion hole 7 ... Guide piece 30 ... Strip forming blank 30a ... Core material 30b ... Brazing material 31 ... Pre-hole 32 ... Guide piece forming protrusion 33 ... Tapered portion 33 ' Parallel part 34 Vertical shear part 34 'Guide surface 39 Arc part 40 Non arc part 50 Blazing sheet 51 Connection strip 52 Excess support piece

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location F28F 9/02 301 C 9141-3L

Claims (3)

[Claims] 1. An oval tube insertion hole (5) is provided,
A method for manufacturing a brazing metal pipe having a guide piece (7) projecting parallel to the insertion tube (1) on at least one side edge of the tube insertion hole (5) in the minor axis direction, A band-shaped forming plate (3) made of a brazing sheet in which a brazing material layer (30b) is applied to at least one surface of a core material (30a).
In (0), a step of forming a pilot hole (31) having a shape corresponding to the tube insertion hole in a state where the guide piece forming projection (32) is left on the side edge in the minor axis direction, and the pilot hole (31 ) Is located on the arc surface, a part of the strip-shaped forming plate (30) in the width direction or the length direction is bent and formed to have an arc cross section to form the arc portion (39), and After the forming, a step of forming the guide piece (7) by projecting the guide piece forming protrusion (32) in the wall thickness direction by subjecting the pilot hole (31) to burring, and after forming the guide piece, A tube insertion, characterized in that it includes a step of bending the non-circular arc portions (40) (40) excluding the circular arc portions (39) of the forming blank plate (30) to form a pipe having both sides edge butting. A method for manufacturing a brazing metal pipe having a guide piece in a hole. 2. A guide piece (1) having an oval tube insertion hole (5) and projecting parallel to the insertion tube (1) on at least one side edge of the tube insertion hole in the minor axis direction. A method for manufacturing a brazing metal pipe having 7), comprising partially removing a brazing sheet (50) having a brazing material layer (30b) adhered to at least one surface of a core material (30a), A step of forming a strip-shaped forming plate (30) having both ends in the length direction or the width direction connected to an extra support piece (52) on the outer side through a connecting strip (51), and the brazing sheet (50) or the strip shape Formed blank (3
In (0), a step of forming a pilot hole (31) having a shape corresponding to the tube insertion hole in a state where the guide piece forming projection (32) is left on the side edge in the minor axis direction, and the pilot hole (31 ) Is located on the arc surface, a part of the strip-shaped forming plate (30) in the width direction or the length direction is bent and formed to have an arc cross section to form the arc portion (39), and After the forming, a step of forming the guide piece (7) by projecting the guide piece forming protrusion (32) in the wall thickness direction by subjecting the pilot hole (31) to burring, and after forming the guide piece, The non-circular arc portions (40) (40) excluding the circular arc portions (39) of the forming blank (30) are bent and formed into a side-to-side edge-butting shape so that excess support is provided via the connecting strips (51). The strip-shaped blank (30) including a step of forming a pipe connected to the piece (52) and a step of separating the pipe from the surplus support piece (52). The steps from the step of forming up pipe separation step, one of the long brazing sheet (50)
A method for manufacturing a brazing metal pipe having a guide piece in a tube insertion hole, which is carried out continuously while intermittently transferring in the length direction. 3. Before bending and forming the arcuate portion (39) of the strip-shaped blank (30), the inner edges of the lower hole (31) in the major axis direction are pressed and deformed, whereby the inner edges are formed. While forming a tapered part (33) that is positioned parallel to the tube insertion direction in the pipe molded state, the outer edges of both ends of the pilot hole in the major axis direction are thick in the pipe molded state in the tube insertion direction. The method for producing a brazing metal pipe having a guide piece in the tube insertion hole according to claim 1, wherein the vertical shearing portion (34) is formed so as to incline in an outwardly open state up to the middle thereof.