JP2002303492A - Manufacturing method for double tube type oil cooler and oil cooler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the manufacturing method of a double-tube type oil cooler and an oil cooler, whose small diametral part 1 as well as large diametral part 2 are constituted of a brazing sheet and which is easily manufactured, while the whole of which can be clamped and fixed uniformly upon brazing. SOLUTION: The small diametral part 1 and the large diametral part 2 are formed of a brazing sheet while the rim 8 of the small diametral part 1 and the rim 9 of the large diametral part 2 are assembled respectively at one place in the peripheral direction of the same to braze and fix the whole of them integrally under the clamped condition.

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 double-pipe type oil cooler mainly used for a water-cooled oil cooler or the like for an automobile and an oil cooler.

[0002]

2. Description of the Related Art In a double-pipe oil cooler, a small-diameter pipe and a large-diameter pipe are coaxially arranged, and both ends in the axial direction of the small-diameter pipe are processed into flares, which come into contact with the inner surface of the large-diameter pipe. . Then, an offset inner fin is usually interposed between the large-diameter pipe and the small-diameter pipe. On the outer circumference of both ends in the longitudinal direction of the large diameter pipe,
The oil port is open. Both pipes are formed by forming brazing sheets each having an inner surface coated with a brazing material into a tubular shape, and welding the joints thereof. Then, the inner circumference of the small-diameter pipe is expanded while the whole is assembled, and the inner fin and each pipe are brought into contact. Next, the whole is inserted into a high-temperature furnace, the brazing material is melted, and the parts are integrally and liquid-tightly brazed and fixed. Also, Japanese Patent Application Laid-Open No. 3-71
No. 942 discloses an "aluminum double-pipe heat exchanger" in which both ends of an outer pipe are bent and joined, and the portions are brazed and fixed.

[0003]

When the small-diameter pipe and the large-diameter pipe each have a brazing sheet formed into a tubular shape and their joints are welded, the small-diameter pipe is uniformly spread due to the presence of a weld when the small-diameter pipe is expanded. May not be able to be expanded, resulting in poor brazing during brazing. Further, there is a disadvantage that the brazing sheet welding tube is troublesome and the production cost is high. Next, the latter "aluminum double tube heat exchanger"
In the case of (1), only the both edges on the large-diameter pipe side are fastened, so the small-diameter pipe needs to be a welded pipe. for that reason,
The overall cost is high. In the latter embodiment, in the example of bending one brazing sheet material,
Since the seams are formed at positions different from each other by 180 ° or more and brazing cannot be performed in a state where the entirety is uniformly fastened, there is a possibility that poor brazing between the inner fin and each pipe may occur. Therefore, an object of the present invention is to provide a method of manufacturing a double-pipe oil cooler with low manufacturing cost and high reliability of brazing and an oil cooler.

[0004]

According to the first aspect of the present invention, a small-diameter tube (1) and a large-diameter tube (2) are coaxially arranged,
An inner fin (3) is interposed between them,
In a method for manufacturing a double-pipe oil cooler in which both axial ends of both pipe sections (1) and (2) are closed in a liquid-tight manner, a brazing filler metal is used.
(5) Bending the brazing sheet coated with
The brazing material is positioned on the mutually facing surfaces of the large-diameter pipe section (2) and the small-diameter pipe section (1), and the edge (8) of the small-diameter pipe section (1) in a non-joined state in parallel with the axial direction. ) And the edge of the large diameter pipe (2)
(9) to form a seam (4) in which the inner fin (3) is in contact with the inner fin (3) through the brazing material.
And both sides (1) and (2) are provided with side covers at both axial ends.
(6) is fitted, and the joint (4) is inserted into the furnace in a state where the outer diameter of the large-diameter pipe portion (2) is reduced so as to be reduced, and the joint (4) is included. This is a method for manufacturing a double-pipe oil cooler in which brazing is integrally fixed.

According to a second aspect of the present invention, in the first aspect, a brazing sheet having at least one surface coated with a brazing material (5) is bent to form a large-diameter pipe portion (2). The small-diameter pipe (1) and the rising part that rises in the radial direction
(7) integrally formed through the edge portion in the bending direction (8)
(9) A double-pipe type oil that is brazed in a furnace with the parts contacting each other at the position of their rising parts (7) and their outer circumferences fastened axially inward by a fastening jig (10). This is a method for manufacturing a cooler. According to a third aspect of the present invention, there is provided a double-pipe oil cooler according to the second aspect, wherein the rising portion (7) and both edges (8) and (9) are positioned obliquely with respect to a radial direction. Is the way.

According to a fourth aspect of the present invention, in the first aspect, the two brazing sheets each having at least one surface coated with a brazing material (5) are bent to form a large-diameter pipe portion.
(2) and the small-diameter tube (1), and the small-diameter tube (1) has both edges (8) in the bending direction projecting radially outward from the outer periphery of the large-diameter tube (2). To form a pair of small-diameter side bent portions, and the large-diameter tube portion (2) is formed at both edges in the bending direction.
(9) is in contact with the small-diameter side bent portion, and both edges are bent, and one of the edges is wound around the other edge and fastened. This is a method for manufacturing a double-tube oil cooler that performs brazing.

According to a fifth aspect of the present invention, there is provided an oil cooler manufactured by the manufacturing method according to any one of the first to fourth aspects.

[0008]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a transverse cross-sectional view of the oil cooler of the present invention at right angles to the axis. FIG.
Is an explanatory view showing an example of a manufacturing process of the small-diameter pipe section 1 and the large-diameter pipe section 2, and FIG. 4 is an assembly explanatory view of the oil cooler.
This oil cooler uses one brazing sheet as shown in FIG.
The small-diameter tube portion 1 and the large-diameter tube portion 2 are integrally formed via the rising portion 7, and the edge 9 of the large-diameter tube portion 2 and the edge 8 of the small-diameter tube portion 1 are joined to the rising portion 7. And the inner fin 3 is interposed between the two pipe portions. That is, the small-diameter tube portion 1 and the large-diameter tube portion 2 are coaxially arranged, and the brazing material 5 is positioned on each of the facing surfaces as shown in FIG.

In this example, the edge 9 of the large-diameter tube portion 2 is bent at an acute angle, and the edge 8 of the small-diameter tube portion 1 is formed at an obtuse angle matching the edge portion. Further, the rising portion 7 is aligned with the edge portion 9, and the both edge portions 8 and 9 and the rising portion 7 are in contact with each other. Then, the edge 9 of the large-diameter tube 2 is brought into contact with the edge 8 of the small-diameter tube 1 via the brazing material 5, and the inner fin 3 is interposed inside. As the inner fin 3, a known offset fin is used. The top and bottom of the wave contact the inner surfaces of the small-diameter tube portion 1 and the large-diameter tube portion 2, respectively.

As shown in FIG. 4, a pair of entrances 15 are formed on the outer surfaces of both ends of the large-diameter tube 2 in the longitudinal direction, and a pair of annular side covers 6 are fitted to the ends of the two tubes 1 and 2. You. Then, FIG.
The outer periphery of the large-diameter tube portion 2 is fastened by an appropriate fastening jig 10 as shown in FIG. 6, and the whole is inserted into a high-temperature furnace to melt the brazing material, and then cooled and solidified to thereby perform heat exchange as shown in FIG. Complete the vessel. A pipe connection boss 16 is brazed and fixed to the periphery of the entrance 15, and an oil pipe (not shown) is connected to the pipe connection boss 16.

FIG. 7 is a cross-sectional view showing a second embodiment of the present invention, FIG. 8 is an enlarged view of a main part thereof, and FIG. In this example, two brazing sheets each having at least one surface covered with a brazing material 5 are bent to form a small-diameter tube 1 and a large-diameter tube 2. Then, the two tube portions 1 and 2 are arranged coaxially. Both ends of the small-diameter tube portion 1 are bent in an L-shape, and the radial height of the small-diameter tube portion 1 protrudes from the outer periphery of the large-diameter tube portion 2 and overlaps each other back to back. Both edges of the large-diameter tube portion 2 are slightly bent into an L-shaped cross section, and one of them is fastened and fixed so that the other edge portion is involved.
Prior to the fastening, as shown in FIG. 9, the inner fin 3 is inserted between the small-diameter pipe portion 1 and the large-diameter pipe portion 2. Thereafter, the edge portion 9 is fastened, and a pair of side lids 6 are provided at both ends thereof. Is fitted.

A pipe connecting boss 16 is arranged at an entrance 15 opened on the outer surface of the large-diameter pipe 2, and the whole is inserted into a high-temperature furnace to melt the brazing material coated on the surface of each part. Then, by cooling and solidifying it, the whole is brazed and fixed in a liquid-tight manner. In this example, since one edge 9 of the large-diameter pipe portion 2 is fastened so as to wind around the other edge 9, a special fastening jig is not required for brazing.

[0013]

According to the method of manufacturing a double-pipe oil cooler of the present invention, the edge 8 of the small-diameter pipe 1 and the edge 9 of the large-diameter pipe 2 are brought into contact via the brazing material. In this state, the outer diameter of the large-diameter tube portion 2 is fastened so as to reduce the outer diameter, and the entire portion is brazed and fixed together. By brazing between the inner fin 3 and the inner fin 3 at the same time, a product with high productivity and high accuracy can be provided.

According to the second aspect of the present invention, the small-diameter tube portion 1 and the large-diameter tube portion 2 are connected by the rising portion 7 by bending a single brazing sheet. Since the edges 9 come into contact with each other at the position of the rising portion 7 and are integrally brazed and fixed in a state of being fastened by the fastening jig 10, it is possible to uniformly fasten the whole at the time of brazing. The reliability of attachment is improved. According to the third aspect of the present invention, the rising portion 7 is provided.
By arranging the edges 8 and 9 obliquely to the radial direction, the fastening force at the time of brazing is reliably and entirely applied, and the reliability of brazing is improved.

According to the present invention, the two brazing sheets are bent to form a small-diameter tube portion 1 and a large-diameter tube portion 2.
The edge 8 of the small-diameter tube 1 protrudes from the outer periphery of the large-diameter tube 2, and both edges 9 of the large-diameter tube 2 contact the edge 8 of the small-diameter tube 1, Since they are fastened so that they are involved, all the joints can be fastened together to improve the reliability of brazing of that part.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of a double-pipe oil cooler according to the present invention.

FIG. 2 is an enlarged view of a main part of the oil cooler.

FIG. 3 is an explanatory view showing an example of a manufacturing process of the small-diameter tube portion 1 and the large-diameter tube portion 2 of the oil cooler.

FIG. 4 is an explanatory view of the assembly of the oil cooler.

FIG. 5 is an explanatory view showing a fastening state at the time of brazing of the oil cooler.

FIG. 6 is a partially cutaway view of the oil cooler.

FIG. 7 is a cross-sectional view showing a second embodiment of the double-pipe oil cooler of the present invention.

FIG. 8 is an enlarged view of a main part of the oil cooler.

FIG. 9 is an explanatory view of the assembly of the oil cooler.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Small-diameter pipe part 2 Large-diameter pipe part 3 Inner fin 4 Seam 5 Brazing material 6 Side cover 7 Standing part 8 Edge 9 Edge 10 Fastening jig 15 Doorway 16 Pipe connection boss

Claims (5)

[Claims] A small-diameter pipe section (1) and a large-diameter pipe section (2) are coaxially arranged, an inner fin (3) is interposed therebetween, and both pipe sections (1) (2) )), The brazing sheet coated with the brazing material (5) is bent and formed, and the large-diameter pipe portion (2) is formed. The brazing material is positioned on the mutually facing surfaces of the small-diameter pipe section (1) and the edge (8) and the large-diameter pipe section (2) of the non-joined small-diameter pipe section (1) in the axial direction, respectively. ) So as to form a seam (4) that comes into contact with the edge (9) through the brazing material, and an inner fin (3) is interposed in both pipes (1) and (2);
Side lids (6) are fitted to both ends of the pipes (1) and (2) in the axial direction, and fastened at the joint (4) so that the outer diameter of the large-diameter pipe (2) is reduced. , Inserted into the furnace and its seam (4)
And a method of manufacturing a double-pipe oil cooler that is integrally brazed and fixed. 2. A large-diameter pipe section (2) and a small-diameter pipe section (1) according to claim 1, wherein one brazing sheet having at least one surface coated with a brazing material (5) is bent. Are formed integrally with each other via a rising portion (7) that rises in the radial direction, and the bent edges (8) (9) are connected to each other by the rising portion.
A method for producing a double-pipe oil cooler in which brazing is performed in a furnace in a state where they are brought into contact with each other at a position (7), and their outer peripheries are fastened axially inward by a fastening jig (10). 3. The method for manufacturing a double-pipe oil cooler according to claim 2, wherein the rising portion (7) and both edges (8), (9) are positioned obliquely with respect to a radial direction. 4. A large-diameter pipe section (2) and a small-diameter pipe section (1) according to claim 1, wherein two brazing sheets each having at least one surface coated with a brazing material (5) are bent. The small-diameter tube (1) has both ends (8) in the bending direction at the large-diameter tube.
(2) forming a pair of small-diameter side bent portions which are projected radially outward from the outer periphery of (2) and overlapped, and the large-diameter tube portion (2) has both edges (9) in the bending direction of the small-diameter side bent portion. Double-tube type, in which both edges are bent so that they touch each other, and one of the edges is fastened so that the other edge is involved, and brazing is performed in the furnace in that state. Oil cooler manufacturing method. 5. An oil cooler manufactured by the manufacturing method according to claim 1.