JPH06159986A - Tube for heat exchnager and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain a tube for a heat exchanger capable of decreasing a defective relative to a header pipe. CONSTITUTION:A tube inserting hole 9 is formed in a header pipe 3 and the end part of a tube 4 coated with a brazing filler metal is inserted into the hole 9. The tube 4 is soldered to the tube inserting hole 9. A plurality of protrusions 12 made of tube materials protruding to the inside of the tube 4 are provided therein. At both end parts of the tube 4, flat parts 10 are provided at positions at least corresponding to the position of the tube inserting hole 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger tube for reducing defective brazing to a header pipe, and a method for manufacturing a heat exchanger tube capable of rationally manufacturing tubes of various sizes.

[0002]

2. Description of the Related Art Heretofore, a tube of this type made by extruding aluminum, or an actual flat plate 2-289.
Although there is a flat tube in which inner fins are inserted as in Japanese Patent Publication No. 80, it is difficult to mold these, and since each passage in the tube is completely partitioned, the stirring action of the heat exchange fluid cannot be obtained. However, there is a problem that the heat exchange efficiency is generally low.

Therefore, as a means for improving the above problems, for example, Japanese Patent Laid-Open No. 3-155422 discloses
A long plate is roll-formed and folded in two, and its edges are brazed, and a number of protrusions are provided on its inner surface, and the opposing protrusions are abutted and brazed, and the heat exchange fluid is placed between them. Is introduced to stir the fluid so as to enhance the heat exchange efficiency.

[0004]

However, while the above-mentioned tube can improve the heat exchange efficiency, when the protrusion is located in the brazing portion when brazing with the header pipe, the recess corresponding to the protrusion and the tube insertion hole are formed. There is a problem that a brazing break occurs between the inner surface and the inner surface, causing brazing failure in the portion.

The present invention solves these problems, reduces brazing defects between the header pipe and the tube, and makes it possible to rationally manufacture tubes of various sizes, and a heat exchanger tube and a manufacturing method thereof. The purpose is to provide.

[0006]

Therefore, in the heat exchanger tube of the present invention, a tube insertion hole is formed in the header pipe, and the end portion of the tube coated with the brazing material is inserted into the hole to insert the tube. In a tube for a heat exchanger, which is brazed into the tube insertion hole and provided with a plurality of projections inwardly projecting the tube material inside the tube, at least at positions corresponding to the tube insertion hole at both ends of the tube. It is characterized in that the flat portion is provided to prevent breakage of brazing between the tube and the tube insertion hole and prevent defective brazing thereof. Further, the manufacturing method of the heat exchanger tube of the present invention,
A plurality of protrusions are formed on opposing aluminum brazing sheets, the sheets are cut into a predetermined length of a tube, the protrusions are butted to each other and brazed, and both side ends of the sheet are brazed. In the method of manufacturing a tube for an exchanger, a plurality of projections and a flat portion having a predetermined area are alternately formed in the lengthwise direction of the sheet, and the sheet is cut at the flat portion or a position close to the flat portion to obtain various dimensions of the tube. The feature is that the cutting position of the sheet corresponding to can be set easily and rationally.

[0007]

The flat portions are provided at both ends of the tube at least at positions corresponding to the tube insertion holes to prevent breakage of the brazing between the tubes and the tube insertion holes and prevent brazing defects thereof. By alternately molding multiple protrusions and flat parts with a predetermined area in the length direction of the sheet and cutting the sheet at or near the flat parts, it is easy to cut the sheet corresponding to various dimensions of the tube. And can be set reasonably.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An illustrated embodiment in which a tube of a condenser equipped with a vehicle air conditioner according to the present invention is manufactured by roll forming will be described below. In FIGS. 1 to 6, reference numeral 1 is a condenser as a heat exchanger. It has a pair of left and right header pipes 2 and 3, and between these header pipes 2 and 3, a plurality of tubes 4 made of aluminum and radiating fins 5 that compose the capacitor core are laminated.

The header pipes 2 and 3 are formed in a substantially elliptic tube shape, which is composed of, for example, an aluminum brazing sheet having an inner and outer surface coated with a brazing material, and an end plate 6 and a tank plate 7 formed in a substantially gutter shape. The two end portions are joined to each other by facing them, and the joint portions 8 are brazed.

A plurality of tube insertion holes 9 and 9 are formed on the peripheral surfaces of the end plates 6 and 6 which face each other. The tubes 4 are inserted into these holes 9 and 9 and their joints are brazed. There is.

The tube 4 is made of, for example, an aluminum brazing sheet whose both surfaces are coated with a brazing material, as described in the above-mentioned Japanese Unexamined Patent Publication (Kokai) No.
As in Japanese Patent Publication No. 155422, roll-forming and folding in two, and flat parts 10 and turbulent flow forming parts 11 of predetermined length are alternately arranged along the lengthwise direction on the opposing peripheral surfaces 4a and 4b. After the bending, the peripheral surfaces 4a and 4b are cut to predetermined lengths with a cutting machine (not shown) after the bending.

Of these, the flat portion 10 is composed of a flat raw surface of an aluminum brazing sheet, and has a length a,
That is, the interval between the adjacent turbulent flow forming portions 11 and 11 is formed to be slightly longer than the outer diameter dimension of the header pipes 2 and 3 on the short diameter side, and the boundary portion between the flat portions 10 and 10 is cut along the cutting line C1. Then, the cutting machine is used for cutting.

Flat portions 10, 10 are located at both ends of the tube 4 cut into a predetermined length. When the tube 4 and the header pipes 2, 3 before brazing are assembled, the flat portion 10 is provided as shown in FIG. The most part is housed in the header pipes 2 and 3, and the base thereof is positioned at the opening of the tube insertion hole 9.

The turbulent flow forming section 11 is composed of a plurality of similar projections 12 projecting inside the tube 4, their shapes and arrangement patterns are set appropriately, and their length b.
Are made to have the same length, and the end faces of the projections 12 are butted against each other and brazed in this case.
It is also possible to continuously provide the whole area of the tube 4 between the flat portions 10, 10 without separately providing.

In the figure, 13 and 13 are flat joints formed by bending the side edges of the peripheral surfaces 4a and 4b into a substantially L-shape.
After bending 4b, these are opposed to each other and brazed, and 14 is a bent portion formed between the peripheral surfaces 4a and 4b. Besides, in the figure, 15 is a partition plate that divides the inside of the header pipes 2 and 3 into upper and lower parts, and 16 is the header pipes 2 and 3.
3 is a cap that closes the upper and lower end portions of 3.

6 and 7 show another embodiment of the present invention, in which the same reference numerals are used for the portions corresponding to those of the above-mentioned embodiment. In this embodiment, the turbulent flow forming portion 11 is provided in the entire area of the tube 4, and the narrow flat portion 10 is provided at both ends of the tube 4, leaving a slight turbulent flow forming portion 11.

The flat portion 10 is formed by deleting a predetermined number of rows of the projections 12 at predetermined positions, which is one row in the embodiment, and the position thereof is predetermined depending on the curved shape of the end plate 6 or the tank plate 7. When the tube 4 after being cut to length is inserted into the tube insertion holes 9 and 9, it corresponds to the periphery of the protrusion 12 located at the opening of the tube insertion holes 9 and 9, and the length a is the length of the tube 4. This is approximately twice the pitch of the protrusions 12 in the direction.

Strictly speaking, the turbulent flow forming section 11 is provided in two types, long and short, that is, a long one located outside the header pipes 2 and 3 and a short one located inside the header pipes 2 and 3. The length b1 of the former is divided into flat parts 1
This corresponds to the length of the projection group located between 0 and 10, and the length b2 of the latter corresponds to the length of the projection group located inside the header pipes 2 and 3.

When the tube 4 is manufactured, the peripheral surfaces 4a and 4b of the aluminum brazing sheet are used.
After the projection 12 is formed on the ridge, it is folded in two around the bent portion 14 and cut into a predetermined length along the cutting line C2. At that time, the cutting line C2 is not limited to the position of the projection 12 as shown in FIG. 8 and can be set to any position parallel to this, and in any case, on one side or both sides of the cutting line C2,
The flat portions 10 and 10 are arranged with the slight turbulence forming portions 11 and 11 having a predetermined length left.

That is, in this embodiment, a part of the turbulent flow forming portion 11 located at the brazing portion is formed flat to maintain the turbulent flow forming portion 11 and prevent brazing failure of the portion.
The turbulence forming portion 11 is also arranged in the header pipes 2 and 3 to strengthen the strength due to the rigidity of the protrusions 12 and improve the pressure resistance performance of the portion, and at the same time, over the entire area of the tube 4, the turbulence forming portion 11 is formed. By forming 11, the characteristic is that the stirring action of the heat exchange fluid is enhanced and the heat exchange efficiency is improved.

In each of the above-mentioned embodiments, the tube 4 is formed by roll forming, but it is also possible to perform this by press forming, and the turbulent flow forming portion 11 has a cylindrical shape as shown in the drawing. Not limited to the protrusions 12, it may be a truncated cone, an elliptical shape, or an oval shape. Further, instead of uniformly forming the heights of the protrusions 12, it is possible to form part of the heights to be low. Is.

In the case of manufacturing the heat exchanger tube thus constructed, for example, an aluminum brazing sheet having a width corresponding to the blank of the tube 4 is coiled on a reel (not shown), which is, for example, disclosed in JP-A-3-15542.
It is supplied to the forming roll (not shown) shown in FIG.

In this way, the aluminum brazing sheet has a circumferential surface 4a, which extends in the longitudinal direction, as shown in FIG.
4b, the bent portion 14, and the joint portions 13 and 13 are formed, and the plurality of protrusions 12 and the flat portion 10 are continuously and alternately formed on the peripheral surfaces 4a and 4b.

In this case, in forming the flat portion 10, for example, the pitch of the uneven portion (not shown) for forming projections formed on the peripheral surface of the forming roll is set to the same width as the flat portion 10. Can be obtained at.

After the above-mentioned forming, the aluminum brazing sheet is sent to a bending machine (not shown) provided adjacent to the forming roll, and is gradually folded in two around the bending portion 14 by the forming machine, as shown in FIG. , 4 are molded.

After that, the molding tube 4 is sent to a cutting machine provided adjacent to the molding machine, and the flat section 1 is cut by the cutting machine.
It is cut at the cutting line C1 provided at 0.

The molded tube 4 thus cut into a predetermined length has flat portions 1 similar to both ends of the inner peripheral surfaces 4a and 4b.
0 is located, and a turbulent flow forming portion 11 composed of a large number of projections 12 is arranged between them, and the flat portion 10 and the turbulent flow forming portion 11 are centered on the center of the tube 4 in the longitudinal direction. It is molded symmetrically.

As shown in FIG. 3, a concave hole is formed on the surface of the molded tube 4 at a position corresponding to the projection 12, and the inside of the tube 4 is surrounded by the peripheral surfaces 4a and 4b as shown in FIG. The protrusions 12 are abutted, and the joints 13, 13 have their inner surfaces superposed, as shown. The same applies to the molded tube 4 of FIGS. 7 and 8.

Next, when the molded tube 4 is assembled to the header pipes 2 and 3 before brazing, first, a pair of end plates 6 and a tank plate 7 are prepared, and these are opposed to each other and fitted together. The partition plate 15 is attached at a predetermined position, and the pair of header pipes 2 and 3 are assembled.

Then, in the tube insertion hole 9 formed in one end plate 6 of these header pipes 2 and 3,
One end of the molded tube 4 is inserted, and the other end is inserted into the tube insertion hole 9 formed in the end plate 6 of the other header pipes 2, 3.

After that, the heat radiation fins 5 are interposed between the tubes 4 and 4, the caps 16 are fitted into the upper and lower ends of the header pipes 2 and 3, and these are temporarily fixed by clips or appropriate jigs and tools.

The heat exchanger 1 temporarily fixed in this way is carried into the brazing furnace, and the brazing parts are brazed at once in the furnace. For example, the end plate 6 and the tank plate 7 are brazed at their joints 8 and 8, and the tube 4 is brazed to the opening of the tube insertion hole 9 by the brazing material on the surface and the brazing material on the inner surface. Protrusion 12 depending on the material
The joints 13 and 13 are brazed by the brazing material on the inner surface while the braces are brazed together.

In this case, since the flat portion 10 is located at the opening portion of the tube insertion hole 9, the molten brazing filler metal is evenly distributed, and the space between the surface of the tube 4 and the opening portion of the tube insertion hole 9 is distributed. Infiltrate and braze them evenly. Therefore, when the concave hole corresponding to the protrusion is located at the opening of the tube insertion hole 9 as in the conventional case, it is possible to prevent the situation where the relevant portion causes brazing and defective brazing.

In this case, in the first embodiment, since the wide flat portion 10 is provided around the opening of the tube insertion hole 9, the molten brazing material does not flow into the concave hole and stay there,
A uniform distribution is promoted, and the brazing failure is strongly prevented. On the other hand, in the second embodiment, since the turbulent flow forming portion 11 is also provided in the header pipes 2 and 3, the stirring action of the heat exchange fluid is enhanced and the rigidity of the protrusions 12 causes
The strength of the portion is enhanced, and the pressure resistance performance can be improved.

[0035]

As described above, since the heat exchanger tube of the present invention is provided with the flat portions at the positions corresponding to at least the tube insertion holes at both end portions of the tube, it causes breakage around the tube insertion hole as in the conventional case. It is possible to prevent brazing between the tube and the inner surface of the tube insertion hole and prevent brazing defects of the tube without worrying that the concave hole integrated with the projection is located. Further, as described above, the method for manufacturing the heat exchanger tube of the present invention alternately forms a plurality of protrusions and a flat portion having a predetermined area in the length direction of the sheet, and cuts the sheet at the flat portion or a position close to the flat portion. By doing so, the cutting position of the sheet can be easily and rationally set according to various dimensions of the tube.

[Brief description of drawings]

FIG. 1 is a front view showing an example of a heat exchanger to which the present invention is applied.

FIG. 2 is an enlarged sectional view showing a main part of one embodiment of the present invention.

FIG. 3 is a perspective view showing a main part of a tube of the present invention, showing a state before brazing.

FIG. 4 is an enlarged sectional view taken along the line AA of FIG.

FIG. 5 is a perspective view showing a main part of a tube of the present invention, showing a situation in the middle of a molding process.

FIG. 6 is a front view showing a main part of the tube of the present invention, showing a situation in the middle of a molding process.

FIG. 7 is a cross-sectional view showing the main parts of another embodiment of the present invention.

FIG. 8 is a front view showing a main part of the other embodiment, showing a situation in the middle of a molding process.

[Explanation of symbols]

 1 heat exchanger 2, 3 header pipe 4 tube 6 tube insertion hole 10 flat part 12 protrusion

Claims (2)

[Claims] 1. A header pipe is formed with a tube insertion hole, and an end portion of a tube coated with a brazing material is inserted into the hole,
While brazing the tube to the tube insertion hole,
A heat exchanger tube having a plurality of projections projecting inward from the tube material, wherein flat portions are provided at both ends of the tube at least at positions corresponding to the tube insertion holes. Tube for heat exchanger. 2. A plurality of projections are formed on opposing aluminum brazing sheets, the sheets are cut into a predetermined length of tubes, the projections are butted to each other and brazed, and both side ends of the sheet are brazed. In the method for manufacturing the heat exchanger tube thus configured, a plurality of protrusions and a flat portion having a predetermined area are alternately formed in the lengthwise direction of the sheet, and the sheet is cut at the flat portion or a position close to the flat portion. A method for producing a heat exchanger tube, which is characterized.