JPH03294Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field This invention is applicable to heat exchangers such as evaporators, condensers, and radiators for car air conditioners,
In particular, the present invention relates to a brazing pipe that is suitably used as a header pipe in a heat exchanger manufactured according to brazing specifications.

BACKGROUND TECHNOLOGY For example, in a heat exchanger as described above, for the purpose of distributing and supplying refrigerant to the heat exchanger body,
Header pipes are commonly used. When the heat exchanger is manufactured according to brazing specifications, the header pipe is formed by forming a brazing sheet into a pipe shape with a brazing metal layer clad on one or both sides of the core material. The tubes and other heat exchanger components are vacuum brazed or flux brazed.

Traditionally, header pipes like the one above are
A so-called electric resistance welded tube has been used in which a brazing sheet is formed into a cylindrical shape with both side edges abutted, and then the abutting portions are electrically resistance welded.

Problems that the invention aims to solve However, since ERW pipes require separate welding to close the butt parts after being formed into a cylindrical shape, the manufacturing process is complicated, welding costs are high, and the header pipe is The disadvantage was that the cost was high.

This invention was made in order to eliminate such drawbacks, and the purpose is to provide a brazing pipe suitable for header pipes, etc., which does not require a welding process after forming the brazing sheet into a cylindrical shape. .

Means for Solving the Problems In order to achieve the above object, this invention enables the brazing sheet to be joined in the subsequent brazing process without having to separately weld the abutting parts on both sides of the sheet. In addition, in order to prevent thermal deformation of the butt part in the opening direction due to thermal expansion during heating, which occurs when the butt part is brazed without being bonded, temporary fixing means are installed at the butt part. It is characterized by having the following.

In other words, the brazing pipe according to this invention is
Referring to the reference numerals in the drawings, an engaging recess 32 is provided on one side of both edges of a brazing sheet 30 in which a brazing material layer 30b is clad on at least one side of a core material 30a, and an engaging recess 32 is provided on the other side. The brazing sheet 30 is formed into a cylindrical shape by bringing its side edges into contact with each other, and the corresponding engaging protrusion 33 and the engaging recess 32 are formed into a cylindrical shape. This feature is characterized in that the abutment portions 31 are fitted into each other in a state that prevents the opening of the abutting portions 31, thereby solving the above-mentioned problem.

Function The brazing sheet 30 is formed into a cylindrical shape by bringing its both side edges into contact with each other, and the engaging recesses 32 and the engaging protrusions 33 provided on each of the both side edges of the brazing sheet are brought into contact with each other. Since the parts 31 are fitted in the opening-preventing state, even if thermal deformation such as thermal expansion occurs in the abutting part due to heating during brazing, the abutting part will not open. Furthermore, since the abutting portions 31 are inevitably joined by brazing, there is no need to perform welding to close the abutting portions before brazing to form an electric resistance welded pipe.

Example Next, an example of this invention will be described.

3 to 7 show a heat exchanger made of aluminum or its alloy as a car cooler condenser using a brazing pipe according to the invention.

In these figures, reference numeral 1 indicates a plurality of tubes arranged vertically in a horizontal state, and reference numeral 2 indicates a corrugated fin interposed between adjacent tubes 1,1. The tube 1 is constructed of a flat extruded aluminum member. This tube 1 may be of a porous type, such as a so-called harmonica tube. The corrugated fin 2 has approximately the same width as the tube 1, and is joined to the tube by brazing. The corrugated fins 2 are also made of aluminum, and preferably have louvers cut and raised.

3 and 4 are left and right header pipes having a circular cross section, and the brazing pipes according to this invention are used as these header pipes. As shown in FIG. 6, each header pipe 3, 4 is provided with tube insertion holes 13 at intervals along its length, and both ends of each tube 1 are inserted into the holes.
Strongly joined and connected by brazing. Further, 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. Further, the lower end of the left header pipe 3 and the upper end of the right header pipe 4 are respectively closed by cover pieces 7 and 8. Furthermore, a partition plate 9 is provided approximately at the center of the left header pipe 3 to divide the header pipe into two upper and lower chambers, while a partition plate 10 is also provided at a position below the center of the right header pipe 4. The refrigerant that flows into the left header pipe 3 from the refrigerant inlet pipe 5 flows in a meandering manner around the entire refrigerant passage constituted by a group of tubes and flows out from the refrigerant outlet pipe 6. Heat is exchanged with the air flowing in the direction shown by arrow W through the air circulation gap including the corrugated fins 2 formed therebetween, and the air is condensed. Note that 1 shown in Figure 3
1 and 12 are upper and lower side plates arranged outside the outermost corrugated fin.

The header pipes 3 and 4 are constructed as follows. That is, as shown in FIGS. 1 and 2, these header pipes are made of a double-sided brazing sheet 30, in which both sides of a core material 30a are coated with brazing metal layers 30b, with both side edges brought into contact with each other. It is molded into a shape. In addition, a plurality of dovetail-shaped engagement recesses 32 are formed on one side edge of the abutting portion 31, and a plurality of inverted trapezoid-shaped engagement recesses 32 that fit into the engagement recesses 32 are formed on the other side edge. An engaging protrusion 33 is formed. Then, each engaging protrusion 33 and the corresponding engaging recess 32 are fitted and brazed to form the header pipes 3 and 4.

To explain the method for manufacturing the header pipes 3 and 4, first, as shown in FIGS. 8 and 9, brazing layers 3 are formed on both sides of a core material 30a made of aluminum.
A brazing sheet 30 of a predetermined size coated with 0b is prepared, and this brazing sheet 3
A plurality of engagement recesses 32 are provided on one side edge in the width direction of 0.
At the same time, an engaging protrusion 33 is formed at a corresponding position on the other side edge. The brazing material layer 30b is generally made of Al-Si with a Si content of approximately 6 to 13 wt%.
Uses alloys of the same type.

Next, as shown in FIG. 10, cuts 34 are formed at the same position on both side edges of the brazing sheet 30. After the two side edges are brought together, the corresponding notches are matched to form the partition plate insertion holes 14 in which the partition plates 9 and 10 are installed.

Next, both ends 35a and 35b of the brazing sheet 30 in the width direction are struck in the thickness direction with a hammer or a press. This blow is applied to the lower surface of one side end 35a and the other side end 35a.
5b on the upper surface, as shown in FIG. 11, one side end has an inclined surface 35 that gradually becomes thinner from the lower edge to the upper edge.
a', and at the other side end, an inclined surface 35 that gradually becomes thinner from the upper edge to the lower edge.
b′ is formed. Furthermore, it is assumed that the brazing material layer 30b is present on both inclined surfaces. By forming both side ends of the brazing sheet 30 in this way, when the both side edges are abutted and formed into a cylindrical shape, the abutted portions 31 overlap and form a cylindrical shape, as shown in FIG. A brazing material layer 30b can be interposed on the contact surface, and sufficient bonding of the abutting portions 31 can be ensured by subsequent brazing.

Next, as shown in FIG. 12, the central part in the width direction of the brazing sheet 30 is pressed along the length direction to form a bulge into a semicircular cross-sectional shape to form the bulge part 3.
form 6.

Next, as shown in FIG. 13, circumferential tube insertion holes 13 are arranged in the bulge 36 at intervals in the length direction of the bulge. This hole-drilling was performed by pressing a mold having a shape that matches the shape of the bulging portion 36 from the lower surface side. By doing so, it is possible to prevent the bulging portion 36 from being crushed or deformed, and the tube insertion hole 13 can be bored at an appropriate position with high dimensional accuracy.

Next, in order to facilitate insertion of the tube 1 into the tube insertion hole 13, preferably, as shown in FIG.
The edge of the tube insertion hole 13 is chamfered.
In the figure, 37 is a chamfered portion.

Subsequently, after performing surface punching as necessary, both horizontal portions 38 of the brazing sheet 30 excluding the bulging portion 36 were bent and formed using a press so as to have a U-shaped cross section as shown in FIG. Thereafter, it is deformed into a round pipe shape while applying an external force using a press so that both side edges meet, and the engagement recess 32 and the engagement protrusion 33 are fitted to obtain the desired header pipes 3, 4. The header pipe manufactured in this way is cleaned as necessary and then sent to the product assembly process.

The production of the heat exchanger consists of header pipes 3 and 4.
After inserting the end of each tube 1 into the tube insertion hole 13 and inserting the partition plates 9 and 10 into the partition plate insertion hole 14, the side plates 11 and 1 are inserted.
This was done by arranging the 2nd grade in a predetermined position and brazing it in one place using furnace brazing or the like. After such brazing, as shown in FIG.
A sufficient fillet 15 is formed at the connection portion between the header pipes 3, 4 and the tube 1, and the header pipes 3, 4 and the tube 1 are firmly joined and integrated without any gaps. And header pipe 3,
A fillet is also formed in each of the abutting portions 31 of No. 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 this invention.

In the figure, 1' is an aluminum tube formed by bending a multi-hole extruded pipe into a meandering shape, 2' is a corrugated fin interposed between parallel parts of the tube, 3' is an inlet header pipe, and 4' is an outlet header pipe. It is.

The header pipes 3' and 4' mentioned above are also
As in the embodiment, the double-sided brazing sheet is formed into a cylindrical shape, and the engaging recesses 32' and the engaging protrusions 33' on both side edges of the brazing sheet are fitted. is formed into a notch having a substantially C-shape when viewed from above, and the engaging convex portion 33' is formed to protrude from a substantially C-shape when viewed from above. In addition, the header pipes 3' and 4' have a single tube insertion hole 1 along the length direction, as shown in Fig. 18.
3' is bored, and this tube insertion hole 1
The end of tube 1' is inserted into 3' and brazed. Note that 6' and 5' shown in FIG. 16 are a refrigerant outlet pipe and an inlet pipe connected to one end of the inlet/outlet header pipe, and 7' and 8' are lid pieces that close the other end of each header pipe.

The header pipes 3' and 4' of the above embodiment also have the first
It was manufactured in the same manufacturing process as the header pipes 3 and 4 of the embodiment, and corresponding parts are shown with the same reference numerals and dash symbols added, but as shown in FIG. The difference is that the tube insertion hole 13', which is bored after forming the bulge 36', is a long hole extending along the length of the bulge 36'.

In the above embodiments, the brazing sheet has a brazing material layer clad on both sides, but the brazing sheet may have a brazing material layer clad on only one side. Furthermore, the shapes of the engaging recess and the engaging protrusion are not limited to the illustrated embodiments, but may be of any shape as long as they prevent the opening of the abutting portions of both side edges of the brazing sheet.

Effects of the invention This invention is as described above, in which the brazing sheet is formed into a cylindrical shape by abutting both sides of the sheet, and the corresponding engaging portions and engaging protrusions provided on both sides of the sheet are formed into a cylindrical shape. Since they are fitted together to prevent the abutting portions from opening, when brazing using this brazing pipe, the abutting portions can be prevented from opening due to thermal deformation during soldering heat, and molding can be prevented. Good brazing can be performed while maintaining the subsequent shape. Of course, after brazing, the butt parts are completely joined by the brazing layer, so it is not necessary to perform welding to close the butt parts before brazing, as with conventional ERW pipes. Therefore, the welding process can be made unnecessary, and the manufacturing process of the brazing pipe can be simplified and the manufacturing cost can be reduced.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional perspective view showing an embodiment of this invention, Fig. 2 is a front view of the same, and Fig. 3 shows a heat exchanger using the brazing pipe shown in Figs. 1 and 2 as a header pipe. 4 is a plan view, FIG. 5 is a sectional view taken along line V-V in FIG. 3, FIG. 6 is a perspective view showing the header pipe, tube, and corrugated fin separated, and FIG. Figure 3 -
Line sectional views, and FIGS. 8 to 15 are diagrams for explaining the manufacturing process of the header pipe shown in FIG. 1. FIG. 8 is a cross-sectional perspective view of a brazing sheet as a material, and FIG. - line sectional view of the figure,
FIG. 10 is a cross-sectional perspective view after the notch is formed, FIG. 11 is a cross-sectional view after the both ends of the brazing sheet are struck, and FIG. 12 is a cross-sectional perspective view after the bulge is formed.
Fig. 13 is a cross-sectional perspective view after drilling the tube insertion hole, Fig. 14 is a side view after chamfering the tube insertion hole, Fig. 15 is a cross-sectional perspective view after forming the tube insertion hole into a U-shaped cross section, and Fig. 16 is a cross-sectional perspective view after the tube insertion hole has been chamfered. 17 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 in FIG. 16 with the header pipe and tube separated; FIG. 18
The figure is an enlarged perspective view of the header pipe shown in FIG. 17, and FIG. 19 is a cross-sectional perspective view of the brazing sheet after the tube insertion hole is bored in the manufacturing process. 3, 3', 4, 4'... Header pipe (pipe for brazing), 30... Brazing sheet, 30
a...core material, 30b...brazing material layer, 31...butt portion, 32, 32'...engaging recess, 33,3
3′...Engaging protrusion.

Claims (1)

[Scope of utility model registration request] A brazing sheet having a brazing material layer clad on at least one side of the core material is provided with an engaging recess on one side of both edges, and an engaging protrusion that is engaged with the engaging recess is provided on the other side, and the brazing sheet is The sheet is formed into a cylindrical shape by abutting both side edges thereof, and the corresponding engagement protrusion and the engagement recess are fitted into each other to prevent the abutment from opening. Pipe for brazing.