JPH05277714A - Production of heat exchanger - Google Patents

Abstract

PURPOSE:To manufacture a heat exchanger, in which welding process is unnecessary after forming a header pipe to a cylindrical shape. CONSTITUTION:On one side of both side edges in a brazing sheet 30 cladding a brazing filler metal layer 30b at least on one side surface in a core material 30a, the engaging recessed parts 32 are arranged and on the other side, engaging projecting pieces 33 are arranged. At the both side edges of the brazing sheet 30, the brazing filler metal coated inclining surfaces corresponding to at least the part except the engaging recessed parts 32 and the engaging projecting pieces 3 in the thikness direction are formed. Then, by mutually butting the brazing metal coated inclining surfaces so as to become the overlapping condition, this sheet is formed to cylindrical state and also, the corresponding engaging projecting pieces and the engaging recessed parts are mutually fitted in the condition of preventing the opening parts at the butting part to make the header pipes 3, 4 with tube inserting holes 13. By executing the brazing after inserting the tubes into the tube inserting holes, the tube, a header pipe and the butting part of the header pipe are brazed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a heat exchanger such as an evaporator for a car air conditioner, a condenser and a radiator, and more particularly to a method of manufacturing a heat exchanger manufactured by brazing specifications.

[0002]

2. Description of the Related Art For example, in the above heat exchanger, a header pipe is generally used for the purpose of distributing and supplying a refrigerant to the heat exchanger body. As such a header pipe, conventionally, a brazing sheet in which a brazing material layer is clad on one side or both sides of a core material is formed into a pipe shape, and the header pipe and the tube are vacuum brazed or flux brazed. As a result, the heat exchanger is manufactured.

Conventionally, as a header pipe in the above heat exchanger, there is a so-called electric resistance welded pipe in which a brazing sheet is formed into a tubular shape with its both side edges abutting each other, and then the abutting portion is resistance-welded. Was used.

However, the electric resistance welded pipe requires a separate welding process for forming a tubular shape and then welding for closing the abutting portions, which complicates the manufacturing process and increases the welding cost. It had the drawback of being expensive.

The present invention has been made in order to solve the above drawbacks, and an object of the present invention is to provide a heat exchanger which does not require a welding process after the header pipe is formed into a tubular shape.

[0006]

In order to achieve the above-mentioned object, the present invention is inevitable in a brazing process to be performed thereafter without separately closing both side edge abutting portions of the header pipe by welding. In addition to paying attention to the fact that the abutting part can be joined to the joint part, in order to prevent thermal deformation in the opening direction of the abutting part due to thermal expansion during heating that occurs when brazing the abutting part without joining, A stop means is provided and measures are taken to ensure the reliable joining of the abutting portions.

That is, in the method for manufacturing a heat exchanger according to the present invention, referring to the reference numerals in the drawings, a brazing sheet (30) in which a brazing material layer (30b) is clad on at least one surface of a core material (30a). Engagement recess (3
2) and an engaging projection (33) engaged with the engaging recess on the other side, and the brazing sheet (3)
On both side edges of (0), brazing filler metal-covered inclined surfaces (35a ') (35b') inclined corresponding to the thickness direction are formed at least in the portions excluding the engaging recesses (32) and the engaging protrusions (33). Then, the brazing material-covered inclined surfaces are made to overlap each other to form a tubular shape, and the corresponding engaging projections (33) and the engaging recesses (32) are formed in the abutting portion (31). By using the header pipes (3) and (4) with the tube insertion holes (13) fitted to each other in the open state and inserting the tubes (1) into the tube insertion holes (13), and then brazing the tubes. , Tube (1) and header pipe (3)
(4) and the abutting portion (31) of the header pipe are brazed and joined together, and the gist is a method for manufacturing a heat exchanger, which can solve the above problems. ..

[0008]

[Function] The brazing sheet (30) is formed into a tubular shape by bringing both side edges of the brazing sheet (30) into an abutting state, and the engaging recesses (3
Since the header pipes (3) and (4), in which 2) and the engaging projection (33) are fitted to each other in a state where the butting portion (31) is prevented from opening, thermal expansion or the like occurs at the butting portion due to heating during brazing. Even if thermal deformation occurs, the abutting portion does not open.
Further, since the abutting portion (31) is inevitably joined by brazing, it is not necessary to perform welding for closing the abutting portion before brazing to form an electric resistance welded pipe.

Further, at least the engaging recess (32) and the engaging projection (3) are provided on both side edges of the brazing sheet (30).
The sloped surface (35a
′) (35b ′) is formed, and the inclined surfaces are mutually abutted to form an overlapping state, so even if expansion force in the radial direction acts due to thermal expansion during brazing, the abutting The gap is prevented only by the misalignment of the inclined surfaces (35a ') (35b') of the portion (30). Moreover, since the brazing material is present on the mutually inclined surfaces (35a ') (35b'), not only the inner or outer surface of the butted portion is brazed, but also the thick portion is brazed. As a result, a strong brazed joint at the butted portion is guaranteed.

In addition, a tube insertion hole (1
The tube (1) is inserted and brazed into the tube 3), and the tube is generally inserted into the tube insertion hole in a press-fitted state. At both ends in the direction, a force in the opening direction of the insertion hole is received, and therefore a force in the closing direction is applied to the abutting portion. Therefore, opening of the abutting portion is prevented more and more, and the heat exchanger does not leak liquid.

[0011]

Embodiments of the present invention will be described below.

FIGS. 3 to 7 show a heat exchanger made of aluminum or its alloy as a car cooler capacitor manufactured according to the present invention.

In these figures, (1) is a plurality of tubes vertically arranged in a horizontal state, and (2) is a corrugated fin interposed between adjacent tubes (1) and (1). The tube (1) is composed of a flat extruded shape member made of aluminum. As the tube (1), a porous type so-called harmonica tube may be used. The corrugated fin (2) has almost the same width as the tube (1) and is joined to the tube by brazing. The corrugated fin (2) is also made of aluminum, and it is preferable to use a louver cut and raised.

(3) and (4) are left and right header pipes having a circular cross section. No. 6 in each header pipe (3) (4)
As shown in the figure, tube insertion holes (13) are formed at intervals along the length direction, both ends of each tube (1) are inserted into the holes, and firmly joined and connected by brazing. Has been done. A refrigerant inlet pipe (5) is connected to the upper end of the left header pipe (3), while an outlet pipe (6) is connected to the lower end of the right header pipe (4).
The lower end of the left header pipe (3) and the upper end of the right header pipe (4) are closed by lid pieces (7) and (8), respectively. Furthermore, a partition plate (9) that divides the header pipe into upper and lower chambers is provided substantially in the center of the left header pipe (3), while the right header pipe (4) is provided.
A partition plate (10) is also provided below the center of the
The refrigerant thus flowing into the left header pipe (3) from the refrigerant inlet pipe (5) circulates in a meandering manner through all the refrigerant passages constituted by the tube group, and flows out from the refrigerant outlet pipe (6) during this period. , Heat is exchanged with the air flowing in the direction indicated by the arrow (W) in the air flow gap including the corrugated fins (2) formed between the tubes (1) and (1), and the air is condensed. In addition, as shown in FIG. 3 (11)
(12) are upper and lower side plates arranged outside the outermost corrugated fins.

The header pipes (3) and (4) are constructed as follows. That is, as shown in FIGS. 1 and 2, these header pipes have a double-sided brazing sheet (30) in which a brazing filler metal layer (30b) is formed on both sides of a core material (30a), and both side edges thereof are butted against each other. It is formed into a tubular shape by being brought into a state. In addition, a plurality of dovetail-shaped engaging recesses (32) are formed on one side edge of the abutting portion (31), and the other side edge is fitted to the engaging recess (32). A plurality of inverted trapezoidal engaging protrusions (33) are formed. Then, each engaging protrusion (3
3) and the corresponding engaging recesses (32) are brazed in a fitted state to form the header pipes (3) and (4).

A method of manufacturing the header pipes (3) and (4) will be described. First, as shown in FIGS. 8 and 9,
Prepare a brazing sheet (30) of a predetermined size in which both sides of a core material (30a) made of aluminum are coated with a brazing material layer (30b), and a plurality of brazing sheets (30) are provided on one side edge in the width direction. The engaging recesses (32) are formed, and the engaging protrusions (33) are formed at corresponding positions on the other side edge. As the brazing material layer (30b), an Al-Si based alloy having a Si content of about 6 to 13 wt% is generally used.

Next, as shown in FIG. 10, notches (34) are formed at the same positions on both side edges of the brazing sheet (30). After the abutting of both side edges, the notches correspond to each other, but the notches are matched with each other, and the partition plate (9)
A partition plate insertion hole (14) for installing the (10) will be formed.

Next, both widthwise end portions (35a) (35b) of the brazing sheet (30) are hammered in the thickness direction with a hammer or a press. This strike is on one side edge (35
For a), the lower surface and the other side edge (35b) are performed on the upper surface, so that one side edge gradually becomes thinner from the lower edge to the upper edge, as shown in FIG. An inclined surface (35a ') is formed, and an inclined surface (35b') which is gradually thinned from the upper edge to the lower edge is formed at the other side end portion. Moreover, the brazing material layer (30b) is present on each of the inclined surfaces. By forming the both ends of the brazing sheet (30) in this way, when the two edges are abutted against each other and formed into a tubular shape, the abutting part (31) is overlapped as shown in FIG. The brazing material layer (30b) can be interposed on the abutting surface in conformity with each other, and sufficient brazing of the abutting portion (31) can be guaranteed by the subsequent brazing.

Next, as shown in FIG. 12, the central portion of the brazing sheet (30) in the width direction is bulged to have a semi-circular cross section by a press along the length direction to bulge the bulged portion (36). To form.

Next, as shown in FIG. 13, the bulge (36)
Further, tube insertion holes (13) along the circumferential direction are arranged at intervals in the length direction of the bulging portion. This perforation is performed by pressing with a pressing die having a shape matching the shape of the bulging portion (36) from the lower surface side. By doing so, the bulging portion (36) can be prevented from being crushed or deformed, and the tube insertion hole (13) with high dimensional accuracy can be formed at an appropriate position.

Next, in order to facilitate insertion of the tube (1) into the tube insertion hole (13), preferably the fourteenth tube is formed.
As shown in the figure, on the bulging side surface of the bulging portion (36),
Chamfer the edge of the tube insertion hole (13). In the figure, (37) is a chamfer.

Then, after chamfering as required, the horizontal portions (38) on both sides of the brazing sheet (30) excluding the bulging portion (36) are pressed by a U-shaped section as shown in FIG. After it is bent and formed into a shape, it is deformed into a round pipe shape while applying an external force by pressing so that both side edges are in abutting shape, and the engaging recess (32) and the engaging protrusion (33) are formed. The desired header pipes (3) and (4) are obtained by fitting them together.
The header pipe thus manufactured is washed as needed and then sent to the product assembling process.

The heat exchanger is manufactured by inserting the ends of the tubes (1) into the tube insertion holes (13) of the header pipes (3) and (4) and partitioning into the partition plate insertion holes (14). After inserting the plates (9) (10), the side plate (1
This was done by placing 1) (12) etc. in a predetermined position and brazing them all together in the furnace. After such brazing, as shown in FIG. 7, a sufficient fillet (15) is formed at the connecting portion between the header pipe (3) (4) and the tube (1), and the header pipe (3) is formed.
(4) and the tube (1) are firmly joined and integrated without a gap. Further, fillets are also formed at the abutting portions (31) of the header pipes (3) and (4), and the abutting portions (31) are hermetically joined.

FIGS. 16 and 17 show a serpentine type evaporator for a car air conditioner as another embodiment of the present invention.

In the figure, (1 ') is an aluminum tube in which a perforated extruded tube is bent in a meandering shape, (2') is a corrugated fin disposed between the parallel portions of the tube, and (3 '). Is an inlet header pipe, and (4 ') is an outlet header pipe.

Similarly to the first embodiment described above, the header pipes (3 ') and (4') are also formed by forming a double-sided brazing sheet into a tubular shape and engaging with engaging recesses (32 ') on both side edges of the brazing sheet. The engaging recess (32 ') is fitted to the engaging recess (32'), and the engaging recess (32 ') is cut out in a substantially C shape in plan view, and the engaging protrusion (33'). Is formed so as to project in a substantially C shape in a plan view. As shown in FIG. 18, the header pipes (3 ′) and (4 ′) are provided with a single tube insertion hole (13 ′) along the length direction. The end of the tube (1 ′) is inserted into the ′ ′ and brazed. Note that (6 ') and (5') shown in FIG. 16 are the refrigerant outlet pipe and the inlet pipe connected to one end of the inlet / outlet header pipe, and (7 ') and (8') close the other end of each header pipe. It is a lid piece.

The header pipes (3 ') (4) of the above embodiment
′) Is also manufactured by the same manufacturing process as the header pipes (3) and (4) of the first embodiment, and the corresponding parts are shown with the same reference numerals but with a dash added. As shown in FIG. 3, the tube insertion hole (13 ′) formed after forming the bulging portion (36 ′) is a long hole along the length direction of the bulging portion (36 ′).

In the above embodiments, the brazing sheet has the brazing material layers clad on both sides, but the brazing material layer may be clad on only one side. Further, the shapes of the engaging recesses and the engaging protrusions are not limited to those shown in the illustrated embodiment, and may be of any form as long as they prevent the opening of both side edge butting portions of the brazing sheet.

[0029]

As described above, according to the present invention, the brazing sheet is formed into a tubular shape by bringing both side edges of the brazing sheet into an abutting state, and at the same time, the corresponding engaging portions and engaging protrusions provided on the both side edges are abutted against each other. Since the brazing is performed using header pipes that are fitted to each other in the opening prevention state of the mating part, it is possible to prevent the abutting part from opening due to thermal deformation when the brazing heat is applied, and to maintain the shape after molding. Good brazing can be performed as it is. Of course, after brazing, the abutting part is completely joined by the brazing material layer, so there is no need to perform welding for closing the abutting part before brazing as in the conventional electric resistance welded pipe, Therefore, the welding process can be eliminated, and the header pipe and the heat exchanger can be simplified in the manufacturing process and the manufacturing cost can be reduced.

Moreover, on both side edges of the brazing sheet, at least portions other than the engaging concave portions and the engaging protrusions are formed with brazing material-coated inclined surfaces which are inclined corresponding to the thickness direction, and the brazing material-coated inclined surfaces are mutually connected. Since they are in contact with each other to form an overlapping state, even if an expanding force in the radial direction acts due to thermal expansion during brazing, the gaps will be created only by the overlapping of the inclined surfaces of the butting part. This can be prevented, and the opening of the abutting portion can be prevented more and more in combination with the effect of preventing the opening due to the engagement between the engagement projection and the engagement recess described above. Moreover, since the brazing material is present on the mutually inclined surfaces of the abutting portion, not only the inner surface or the outer surface of the abutting portion is brazed, but also the thick portion is brazed. A strong brazed joint of the parts can be guaranteed.

Moreover, the tube is inserted into the tube insertion hole of the header pipe and brazed in this state. Since the tube is generally inserted into the tube insertion hole in a press-fitted state, this tube The press-fitting causes the pipe to receive a force in the opening direction of the insertion hole at both ends of the tube insertion hole in the circumferential direction, and therefore a force in the closing direction is applied to the abutting portion. For this reason, it is possible to further prevent the abutting portion of the header pipe from being opened, and it is possible to obtain a heat exchanger without liquid leakage.

[Brief description of drawings]

FIG. 1 is a sectional perspective view showing an example of a header pipe used in the present invention.

FIG. 2 is a front view of the same.

FIG. 3 is a front view of a heat exchanger using the brazing pipe shown in FIGS. 1 and 2 as a header pipe.

FIG. 4 is a plan view of the same.

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

FIG. 6 is a perspective view showing a header pipe, a tube, and a corrugated fin separately.

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

8 is a diagram for explaining a manufacturing process of the header pipe shown in FIG. 1, and is a cross-sectional perspective view of a brazing sheet as a material.

9 is a sectional view taken along line IX-IX in FIG.

FIG. 10 is a cross-sectional perspective view after forming a notch.

FIG. 11 is a cross-sectional view after hitting both end portions of the brazing sheet.

FIG. 12 is a cross-sectional perspective view after formation of a bulge.

FIG. 13 is a cross-sectional perspective view of the tube insertion hole after being punched.

FIG. 14 is a side view after chamfering the tube insertion hole.

FIG. 15 is a cross-sectional perspective view after being formed into a U-shaped cross section.

FIG. 16 is a perspective view of a heat exchanger using another brazing pipe as a header pipe.

FIG. 17 is a perspective view showing the vicinity of the header pipe of FIG. 16 with the header pipe and the tube separated.

FIG. 18 is an enlarged perspective view of the header pipe shown in FIG.

FIG. 19 is a cross-sectional perspective view of the brazing sheet after the tube insertion hole is formed in the manufacturing process of the header pipe shown in FIG.

[Explanation of symbols]

 1 ... Tube 3, 3 ', 4, 4' ... Header pipe 13, 13 '... Tube insertion hole 30 ... Brazing sheet 30a ... Core material 30b ... Brazing material layer 31 ... Collision part 32, 32' ... Engagement recess 33, 33 '... Engaging protrusion

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nobori Nobori 6224, Kaiyamacho, Sakai City, Osaka Prefecture Showa Aluminum Co., Ltd. (72) Tadashi Usui, 6224, Kaiyamacho, Sakai City, Osaka Showa Aluminum Within the corporation

Claims (1)

[Claims] 1. A brazing sheet (30) in which a brazing filler metal layer (30b) is clad on at least one side of a core material (30a).
An engaging recess (32) is provided on one of both side edges of the, and an engaging projection (33) engaged with the engaging recess is provided on the other side, and both side edges of the brazing sheet (30) are At least a portion excluding the engagement recess (32) and the engagement projection (33), the brazing material-covered inclined surface (35a ') inclined corresponding to the thickness direction.
(35b ') is formed, and the brazing material-covered inclined surfaces are made to collide with each other to form an overlapping state, whereby a cylindrical shape is formed, and the corresponding engaging projection (33) and the engaging recess (32) are made to collide with each other. Header pipe (3) with a tube insertion hole (13) that is fitted into the mating part (31) in the open-blocking state.
(4) is used to insert the tube (1) into the tube insertion hole (13) and then braze the tube (1) and the header pipes (3) and (4), and the abutting portion of the header pipe (3). 31) A method for manufacturing a heat exchanger, which comprises brazing and joining.