JP2000088485A - Heat exchanger and machining thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent strength from lowering even if a base board is made thin by forming a recess in the base board through drawing while having an offset face part parallel with the surface of the base board and making a fixing hole in the center of the offset face part while being surrounded by the offset face part. SOLUTION: Recesses 19 having offset face part 18 pushed to be parallel with the face of a base board 16 are formed, at a specified interval, in the vicinity of the opposite end parts of the base board 16 in the longitudinal direction by drawing. Four fixing holes 20, for example, having a specified diameter are made in the center of the offset face part 18. Since strength is increased at the part surrounding the fixing hole through hardening at the time of drawing over the entire circumference and rigidity is increased at that part through formation of a three-dimensional offset face part, strength of fixing hole is increased and since that part is not cut off, a thick base board is not required resulting in a lightweight heat exchanger.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger and a method of processing the same, and more particularly to an improvement in a mounting hole formed in a substrate for mounting the heat exchanger to an automobile engine and a method of processing the same.

[0002]

2. Description of the Related Art FIGS. 4 and 5 show an aluminum heat exchanger (radiator) mounted on an automobile engine. The heat exchanger 1 has a large number of fin-wound pipes, and a cooling water passage joint 4 attached to an engine block 5 is fixed to a lower portion thereof. Has an aluminum substrate 6 fixed thereto by brazing. In the vicinity of both ends in the longitudinal direction of the substrate 6, mounting holes 3 for bolts for mounting the heat exchanger 1 to the engine block are formed at a plurality of locations. The cooling water flows between the heat exchanger and the engine block 8 via a passage inside the joint 4.

[0003]

The substrate 6 of the heat exchanger 1 is brazed to a joint in a furnace, so that the temperature of the substrate 6 becomes, for example, about 600 ° C., and the substrate 6 is annealed and softened. The strength of the mounting hole 3 may be reduced, and the mounting hole 3 may be cut off by vibration of the engine. Therefore, assuming that the strength of the substrate 6
Therefore, there is a problem that the thickness of the heat exchanger increases, and the weight of the heat exchanger increases.

In view of the foregoing, an object of the present invention is to provide a heat exchanger having a mounting hole having a small thickness of a substrate, a light weight of the heat exchanger, and a strength that does not decrease. Things.

[0005]

In order to solve the above-mentioned problems of the prior art, according to the present invention, a concave portion having an offset surface portion parallel to the surface is formed in a substrate, and a mounting hole is formed in the offset surface portion. It is provided. Alternatively, a protrusion having an offset surface portion parallel to the surface may be formed on the substrate, and a mounting hole may be provided in the offset surface portion.

Further, according to the present invention, a substrate having a mounting hole is brazed to a joint of a heat exchanger in a heating furnace, and an area of the mounting hole is formed with an offset surface shifted from the substrate surface. Plastic working such as drawing, and the area of the mounting hole is strengthened by work hardening.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a heat exchanger according to an embodiment of the present invention. The structure of the heat exchanger 15 itself is the same as that of the conventional technique shown in FIG.

As shown in FIG. 1, a substrate 16 to be brazed to a joint portion (having a cooling water flow hole) of a cooling water tank portion (header) 2 of a heat exchanger 15 to an engine.
Is made of an aluminum material, has a rectangular shape, and has an edge portion 17 formed by bending the edge of the substrate 16 into an L shape on both edges in the longitudinal direction.
Therefore, the substrate 16 has an inverted U-shape when viewed from the longitudinal direction. At a predetermined interval in the vicinity of both ends in the longitudinal direction of the substrate 16, as shown in FIG. 2, a concave portion 19 having an offset surface portion 18 pressed down so as to be parallel to the surface of the substrate 16 is pressed. It is formed by molding. And this offset surface part 1
8 is provided with a mounting hole 20 having a predetermined diameter
It is formed in the place.

FIG. 3 shows another embodiment of the mounting hole portion 21. The convex portion 23 in which the offset surface portion 22 formed so as to be parallel to the surface of the substrate 16 is formed by press molding. A mounting hole 21 is formed at the center of the offset surface 22. Thus, the mounting holes 20, 21
Since the work hardening occurs by press-forming the concave portion 19 or the convex portion 23 and the strength of the mounting holes 20 and 21 increases, it is not necessary to increase the thickness of the substrate 16. Further, since the mounting holes 20 and 21 have a three-dimensional shape as compared with the conventional two-dimensional shape, the rigidity is increased.

The forming or plastic working of the concave portion 19 or the convex portion 23 is performed after all the components of the heat exchanger 15 are temporarily assembled and brazed in a furnace. That is, as described above,
The brazing of the heat exchanger substrate to the joint is performed in a heating furnace, where the substrate is annealed and softened, reducing the strength of the mounting holes. However, after the brazing in the furnace, by performing the drawing process of the concave portion 19 or the convex portion 23, work hardening occurs in the mounting hole portion, the rigidity is increased, and the strength is increased.

[0011]

As described above, in the heat exchanger of the present invention, since the mounting hole formed in the substrate of the heat exchanger is formed in the offset surface portion which is parallel to the substrate, it is not necessary to form the mounting hole. The strength of this part increases due to the work hardening of the part, and the formation of the offset surface part makes the part three-dimensional and the rigidity increases, so the strength of the mounting hole part increases and the part does not cut, It is not necessary to increase the thickness of the substrate, and the weight of the heat exchanger can be reduced.

Further, in the heat exchanger processing method of the present invention, the mounting hole of the substrate, which has been annealed and softened by brazing the substrate to the heat exchanger body in a furnace, is processed by plastic working for forming an offset surface portion. Can be hardened and strengthened.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one embodiment of a mounting hole of a heat exchanger according to the present invention.

FIG. 2 is a sectional view of a mounting hole in FIG. 1;

FIG. 3 is a partial sectional view showing another embodiment of the mounting hole of the heat exchanger of the present invention.

FIG. 4 is a plan view of the heat exchanger.

FIG. 5 is a perspective view of a conventional mounting hole.

[Explanation of symbols]

 2 Tank part 9 Joint 15 Heat exchanger 16 Substrate 18 Offset surface part 19 Concave part 20 Mounting hole 21 Mounting hole 22 Offset surface part 23 Convex part

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[Procedure amendment]

[Submission date] August 9, 1999 (1999.8.9)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents]

[Document Name] Statement

Patent application title: Heat exchanger and processing method thereof

[Claims]

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger and a method of processing the same, and more particularly to an improvement in a mounting hole formed in a substrate for mounting the heat exchanger to an automobile engine and a method of processing the same.

[0002]

2. Description of the Related Art FIGS. 4 and 5 show an aluminum heat exchanger (radiator) mounted on an automobile engine. The heat exchanger 1 has a large number of fin-wound pipes, and a cooling water passage joint 4 attached to an engine block 5 is fixed to a lower portion thereof. Has an aluminum substrate 6 fixed thereto by brazing. In the vicinity of both ends in the longitudinal direction of the substrate 6, mounting holes 3 for bolts for mounting the heat exchanger 1 to the engine block are formed at a plurality of locations. The cooling water flows between the heat exchanger and the engine block 8 via a passage inside the joint 4.

[0003]

The substrate 6 of the heat exchanger 1 is brazed to a joint in a furnace, so that the temperature of the substrate 6 becomes, for example, about 600 ° C., and the substrate 6 is annealed and softened. The strength of the mounting hole 3 may be reduced, and the mounting hole 3 may be cut off by vibration of the engine. Therefore, on the premise that the strength is reduced, the substrate 6
Therefore, there is a problem that the thickness of the heat exchanger increases, and the weight of the heat exchanger increases.

In view of the above, the present invention has been made to provide a heat exchanger having a mounting hole having a small thickness of a substrate, a light weight of the heat exchanger, and the strength of which is not reduced, and a method of processing the same. It was made for the purpose.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems of the prior art, according to the present invention, a concave portion which has an offset surface portion parallel to the surface thereof and is formed by drawing is formed. A mounting hole is provided at the center of the offset surface in a state surrounded by the offset surface. Alternatively, the substrate may have an offset surface portion parallel to the surface, form a convex portion formed by drawing, and provide a mounting hole at the center of the offset surface portion in a state surrounded by the offset surface portion.

Further, according to the present invention, a substrate having a mounting hole is brazed to a joint of a heat exchanger in a heating furnace, and then the entire area of the mounting hole is offset from the substrate surface by an offset surface. Is formed so as to form a hole, and a region surrounding the mounting hole is strengthened by work hardening.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a heat exchanger according to an embodiment of the present invention. The structure of the heat exchanger 15 itself is the same as that of the conventional technique shown in FIG.

As shown in FIG. 1, a substrate 16 to be brazed to a joint portion (having a cooling water flow hole) of a cooling water tank portion (header) 2 of a heat exchanger 15 to an engine.
Is made of an aluminum material, has a rectangular shape, and has an edge portion 17 formed by bending the edge of the substrate 16 into an L shape on both edges in the longitudinal direction.
Therefore, the substrate 16 has an inverted U-shape when viewed from the longitudinal direction. At a predetermined interval in the vicinity of both ends in the longitudinal direction of the substrate 16, as shown in FIG. 2, a concave portion 19 having an offset surface portion 18 pressed down so as to be parallel to the surface of the substrate 16 is press-formed ( (Draw forming). At the center of the offset surface portion 18, mounting holes 20 having a predetermined diameter are formed, for example, at four locations in a state surrounded by the center portion.

FIG. 3 shows another embodiment of the mounting hole portion 21. Press-forming (draw-forming) a convex portion 23 having an offset surface portion 22 which is pushed up so as to be parallel to the surface of the substrate 16 is formed. ), And a mounting hole 21 is formed in the center of the offset surface 22 in a state surrounded by the center. As described above, work hardening occurs in the mounting holes 20 and 21 by press forming the concave portion 19 or the convex portion 23,
Since the strength of the mounting holes 20 and 21 increases, the substrate 16
Need not be thick. Also, the mounting holes 20, 21
Since the portion has a three-dimensional shape compared to the conventional two-dimensional shape, the rigidity is increased.

The forming or plastic working of the concave portion 19 or the convex portion 23 is performed after all the components of the heat exchanger 15 are temporarily assembled and brazed in a furnace. That is, as described above,
The brazing of the heat exchanger substrate to the joint is performed in a heating furnace, where the substrate is annealed and softened, reducing the strength of the mounting holes. However, after the brazing in the furnace, by performing the drawing process of the concave portion 19 or the convex portion 23, work hardening occurs in the mounting hole portion, the rigidity is increased, and the strength is increased.

[0011]

As described above, in the heat exchanger of the present invention, since the mounting hole formed in the substrate of the heat exchanger is formed in the offset surface portion which is parallel to the substrate, it is not necessary to form the mounting hole. Due to the work hardening, the strength of the part surrounding the mounting hole increases over the entire circumference, and the formation of the offset surface part makes the part three-dimensional and increases rigidity, so the strength of the mounting hole part increases and the part increases However, there is no need to increase the thickness of the substrate, and the weight of the heat exchanger can be reduced.

Further, in the heat exchanger processing method of the present invention, the mounting hole of the substrate, which has been annealed and softened by brazing the substrate to the heat exchanger body in a furnace, is mounted by plastic working for forming an offset surface portion. Work hardening can occur around the hole to strengthen it.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one embodiment of a mounting hole of a heat exchanger according to the present invention.

FIG. 2 is a sectional view of a mounting hole in FIG. 1;

FIG. 3 is a partial sectional view showing another embodiment of the mounting hole of the heat exchanger of the present invention.

FIG. 4 is a plan view of the heat exchanger.

FIG. 5 is a perspective view of a conventional mounting hole.

[Description of Signs] 2 Tank part 9 Joint 15 Heat exchanger 16 Substrate 18 Offset surface part 19 Concave part 20 Mounting hole 21 Mounting hole 22 Offset surface part 23 Convex part

Claims (3)

[Claims] 1. A heat exchanger having a substrate having a mounting hole formed therein, wherein the substrate is provided with a concave portion having an offset surface portion parallel to the substrate surface, and the mounting surface is provided with the mounting hole. A heat exchanger. 2. A heat exchanger having a substrate having a mounting hole formed therein, wherein the substrate has a projection provided with an offset surface portion parallel to the surface thereof, and the mounting hole is provided on the surface portion. A heat exchanger. 3. A substrate having a mounting hole formed therein is brazed to a joint for flowing a heat exchange medium of a heat exchanger in a heating furnace, and then a region of the mounting hole is offset from a surface of the substrate. A method for processing a heat exchanger, wherein plastic working is performed so that a hole is formed, and work hardening occurs in a region of a mounting hole.