JPH0147256B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a heat exchanger, and more specifically, a method for manufacturing a multi-passage heat exchanger.

The main object of the present invention is to provide a new method of manufacturing a heat exchanger.

Another object of the present invention is to provide a new method for manufacturing a multi-passage cylindrical heat exchanger.

The multi-passage tubular heat exchanger is described in U.S. Pat. No. 3,229,722 by the inventor or
Generally known as No. 3692105, No. 3746086, etc.

Another object of the present invention is to provide an improved method of manufacturing the multi-passage cylindrical heat exchanger described above.

In the production of conventional multi-passage cylindrical heat exchangers,
Usually, the partition wall that partitions the cylindrical member into a plurality of elongated passages is formed by extrusion. However, it is extremely difficult, if not impossible, to form a single, multi-channel cylindrical body using an extrusion method for certain metals (for example, copper and steel).

An important object of the present invention is to provide a method for manufacturing a multi-passage cylindrical heat exchanger that can be easily formed using such metals.

Still another object of the present invention is to provide a method of manufacturing a cylindrical heat exchanger having spaced apart protruding fins using such a metal.

Yet another object of the present invention is to provide a new method for manufacturing cylindrical heat exchangers that is practical, efficient and economical to use.

In the present invention, a metal cylinder having a circular cross section is formed, and the cylinder is flattened over its entire length to have a substantially rectangular cross-sectional shape having an upper wall, a lower wall, and a side wall. Next, at least one wire whose outer surface has a melting point lower than that of the cylindrical body is inserted, and the outer surface of the wire is fixed to the upper wall and the lower wall. This is the manufacturing method.

The outer surface of the wire is fixed to the upper and lower walls of the cylinder by heating the cylinder and the wire at a temperature higher than the melting point of the outer surface of the wire and lower than the melting point of the cylinder. This can be achieved by pressing the upper wall and the lower wall to bring them into close contact with the wire.
Further, while pressing the upper wall and the lower wall, it is desirable to cool the cylinder and the wire at a temperature lower than the melting point of the outer surface of the wire.

Preferred embodiments of the present invention will be described below based on the drawings.

The cylindrical body 1 having a circular cross section becomes a heat exchanger 2 having a substantially rectangular cross section as shown in FIG. It has a plurality of fins 4 provided at intervals in the longitudinal direction.

As mentioned above, the present invention is particularly useful when metals such as copper and steel, which are difficult to use by extrusion, are used for the cylinder 1, but it is needless to say that the present invention is not limited to these metals. .

As shown in the figure, the original shape of the cylindrical body 1 has a substantially circular cross section, and includes an annular main body 5 and a penetrating hole 6 formed by the main body 5. As a preferable form of this cylinder 1, the main body part 5
A plurality of protrusions 7 are provided on the outer surface thereof at equal intervals in parallel to each other along the longitudinal direction.

In carrying out the present invention, the cylinder 1 is flattened from a circular shape as shown in FIG. 1 to a substantially rectangular or oval shape as shown in FIG. This flattening can be achieved by any desired method, such as passing the cylinder through a rolling mill having pairs of rollers gradually brought closer to each other. Preferably, before flattening, the mandrel 8 shown in FIGS. 2 and 3 is inserted into the cylinder 1 (FIG. 2). The intention of inserting the mandrel 8 is to prevent said flattening from becoming excessive.

When the cylinder 1 is flattened in a suitable state as shown in FIG. 3, the main body 5 and the projection 7 have an upper wall 9 and a lower wall 10, and the upper wall and the lower wall are flat and parallel. and are spaced apart from each other,
They are connected by side walls 11 and 12. Cylinder 1
In the flattening of the hole 6, the hole 6 is deformed into a substantially rectangular shape (FIG. 3).

Thereafter, in a preferred embodiment of the invention, a plurality of wires 13 are spaced parallel to each other and also to the side walls 11, 12 (FIG. 4). This wire 13 has at least the outer surface of the cylindrical body 1
The material should have a melting point lower than that of the material. For example, the melting point is approximately
When forming the cylinder 1 with steel at 1427℃ (2600〓),
The wire 13 is made of copper having a melting point of about 871°C (1600°C) or of steel coated with copper having a melting point of about 871°C. Of course, in the case of the steel cylinder 1, the wire 1
3. Low melting point metal other than the above, for example about 399℃
Zinc with a melting point of (750〓) or about 593℃
It can be formed from aluminum, which has a melting point of (1100〓).

On the other hand, if the cylinder 1 is made of copper, in a preferred embodiment of the present invention, the wire 13 cannot be made of steel (of course, it cannot be coated with a metal whose melting point is lower than that of the copper of the cylinder). ). The reason for this is that it is desirable that the melting point of the wire 13 be lower than the melting point of the cylinder 1, as will be explained below.

The wire 13 is temporarily engaged in a predetermined position of the cylindrical body 1 for the next step of the present invention.
A preferred method for this is to shape the cross-sectional shape of the wire 13 itself so that it fits snugly within the opening 6 and to be slidably frictionally engaged, or between the wires 13 in the vicinity and the side walls 11 and 12. This can also be achieved by inserting a suitable wafer, such as carbon, having a thickness smaller than that of the wire 13 between the wire 13 and the wire 13 closest to it.

The wire group 13 is provided on the cylinder 1 as described above, and the cylinder 1 is fed into the heating device H shown briefly in FIG. The upper wall 9 and the lower wall 10 of the cylinder 1 are heated to a temperature higher than the melting point of at least the outer surface of the wire 13 by means of a heat induction collar or a microwave heating device, etc. It is held firmly in engagement with the wire group 13 by means. While the upper wall 9 and the lower wall 10 are in close contact with the wire group 13, the wire group 13 is cooled at a temperature lower than the above-mentioned melting point, and the wire group 13 is held at a predetermined position within the cylinder 1 by brazing. It is. In FIG. 7, reference numeral 16 indicates a fused portion of the wire group 13, which is connected to the wall portions 9 and 10 by this fused portion 16. In this way, the wire group 13 is fixed within the cylindrical body 1.

When the wire group 13 is held within the cylindrical body 1, the fourth
The result is a complete assembly as shown in the figure. Next, the fins 4 are formed from the protrusions 7 that protrude outward from the upper wall 9 and the lower wall 10. As for the method of forming the fins, the protrusions 7 are formed as disclosed in the above-mentioned US Pat. No. 3,692,105. Any desired method can be employed, such as by cutting or by cutting into the main body portions 5 of the wall portions 9 and 10 to stand upright. Due to the formation of the fins 4, the square fins have a main portion 17 formed by cutting into the main body portion 5 of the cylindrical body 1, and extend over the entire width of the wall portions 9, 10. Reference numeral 18 is a barb-like projection formed by cutting the projection 7, and is a portion projecting outward from the main portion 17.

Of course, if necessary, Huynh 4 is based on U.S. Pat.
As disclosed in No. 3229722 and No. 3202212, wall portions 9 and 1
0 may be formed from only the protrusion 7, and in this case, the fin becomes only a barb-like protrusion 18 without the main part 17 serving as the base, as shown in FIG.

As mentioned above, in a preferred embodiment of the invention, the wire group 13, or at least its outer surface, has a lower melting point than the cylinder 1. By doing this, when the wire group 13 is brazed into the cylinder body 1, the cylinder body 1 is not deformed, and the brazing is ensured at a temperature below the melting point of the cylinder body 1. can be caused to occur.

Although the above embodiment shows an example using a plurality of wires 13, the present invention is not limited to this. Only one wire 13 is used, and two wires are placed on both sides of the wire.
It is also possible to use a two-passage type heat exchanger with separate passages.

As described above, according to the present invention, a cylindrical heat exchanger having a plurality of passages can be formed extremely easily and quickly, and furthermore, it is difficult to make a multi-passage type one by extrusion. It is a method that can efficiently form the above-mentioned metals, and is a practically excellent method that can achieve the various objects of the present invention.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and it goes without saying that various changes can be made within the scope of the claims.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a cylindrical body adopted as a preferred embodiment of the present invention, and FIGS.
5 is a cross-sectional view of the cylinder shown in the figure, illustrating the steps of the manufacturing method according to the present invention, FIG. 5 is an explanatory diagram showing the next process for the cylinder shown in FIG. 4, and FIG. It is a cross-sectional view similar to the figure but more detailed,
FIG. 7 is a cross-sectional view showing the details of a state taken along the line 7--7 in FIG. 6, showing the next step in the preferred embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Cylindrical body, 2... Heat exchanger, 3... Passage formed in the heat exchanger 2, 4... Fin, 5... Main body part of the cylinder 1, 6... Hole of the cylinder 1, 7... Cylindrical body 1 8... Mandrel for flattening the cylinder 1, 9... Upper wall, 10... Lower wall, 11, 12... Side wall, 13... Wire, 14... Heating unit, 15...
Roller, 16... Melting part of wire 13.

Claims (1)

[Claims] 1. A metal cylinder with a circular cross section is formed, and the cylinder is flattened over its entire length to have a substantially rectangular cross-sectional shape having an upper wall, a lower wall, and a side wall. and inserting at least one wire whose outer surface has a melting point lower than that of the cylinder into the cylinder, and fixing the outer surface of the wire to the upper wall and the lower wall by heating to form a multi-passage. A method for manufacturing a multi-passage heat exchanger. 2. The outer surface of the wire is fixed to the upper wall and the lower wall by heating the cylindrical body and the wire at a temperature higher than the melting point of the outer surface of the wire and lower than the melting point of the cylindrical body. 2. The manufacturing method according to claim 1, wherein said upper wall and said lower wall are pressed to bring them into close contact with said wire. 3. The manufacturing method according to claim 2, which includes the step of cooling the cylindrical body and the wire at a temperature lower than the melting point of the outer surface of the wire while pressing the upper wall and the lower wall. . 4. The manufacturing method according to claim 1, wherein the cylindrical body has a plurality of parallel and spaced apart protrusions that protrude outward along the longitudinal direction of the cylindrical body. 5. The manufacturing method according to claim 4, wherein outwardly projecting fins are formed at intervals along the longitudinal direction of the protrusion. 6. The manufacturing method according to claim 4, wherein fins projecting outward from the protrusion, the upper wall, and the lower wall are formed at intervals along the longitudinal direction of the cylindrical body. 7 The outer surface of the wire is fixed to the upper wall and the lower wall by heating the cylindrical body and the wire at a temperature higher than the melting point of the outer surface of the wire and lower than the melting point of the cylindrical body. Claim 6: The method is carried out by extruding the upper wall and the lower wall to bring them into close contact with the wire, and cooling the cylinder and the wire at a temperature lower than the melting point of the outer surface of the wire. Manufacturing method described in section. 8. The manufacturing method according to claim 7, wherein the cylindrical body is made of steel, and at least the outer surface of the wire is made of copper. 9. The manufacturing method according to claim 1, wherein a plurality of the wires are inserted into the cylinder at intervals. 10. The manufacturing method according to claim 5, wherein the fins are formed by cutting the upper wall and the lower wall and standing them upright.