JP2000213889A - Tube plate of heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the crack of the root parts between a tube and a tube plate by absorbing large stress that is generated at both the end parts in the longitudinal direction of the tube plate due to thermal expansion. SOLUTION: The middle part of a tube plate 4 of a heat exchanger is stiff due to the presence of a vertical rib 5 and is less apt to be deformed even if outer force is applied near the root parts between a flat tube 3 and a flat hole 2. However, since no vertical rib 5 exists at an area 6 without any ribs being formed at both end parts in the longitudinal direction of the tube plate 4, it is apt to be deformed when outer force is applied. Therefore, the thermal expansion of the tube located rear both the end parts is smaller than that of the tube being located at the middle part of a heat exchanger core and thermal stress is absorbed due to the easy deformation of the area without any ribs, thus preventing cracks from occurring at the root parts between the tube near both the ends of the tube plate and the tube plate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiator for cooling engine cooling water, and has a long length of a large number of tubes arranged in parallel, such as a cross flow type (tanks are arranged left and right separated). If applicable for the tube plate.

[0002]

2. Description of the Related Art A cross flow type radiator having a low core and a wide width has a pair of tanks spaced apart left and right, and a number of long flat tubes are arranged in parallel between tube plates of each tank. You. Then, fins are arranged between the tubes.

[0003]

As the length of the tube increases, the elongation of the tube increases with thermal expansion.
However, the upper and lower ends of the heat exchanger core have good ventilation and are relatively easily cooled. Therefore, the thermal expansion of the tubes at the upper and lower ends is less than that at the middle. Then, a distortion occurs due to a difference in elongation between the two. In particular, cracks are likely to occur at the roots of the tubes and the tube plate at both ends in the longitudinal direction of the tube plate, which may cause water leakage. Therefore, an object of the present invention is to solve such a problem.

[0004]

SUMMARY OF THE INVENTION According to the present invention, the periphery of each of a pair of elongated tank bodies 1 which are separated from each other is joined to each other to close the tank body 1 and extend in the longitudinal direction. A number of flat holes 2 are drilled with their long axes parallel to the width direction and spaced apart from each other at regular intervals, and both ends of the flat tube 3 are inserted into each of the flat holes 2. In the tube plate 4 of the heat exchanger, which is brazed and fixed, a longitudinal rib 5 for reinforcement is provided between the adjacent flat holes 2 at the longitudinally intermediate portion of the tube plate 4, and the longitudinal axis of the flat holes 2 is long. Are formed between the flat holes 2 at both ends in the longitudinal direction of the tube plate 4 so as to have no ribs 6 respectively. Area 6 is thick against external force Direction of deformation, a tube plate of a heat exchanger, characterized in that formed in the intermediate portion of the rib there easily so than that of the area.

According to a second aspect of the present invention, in the first aspect, the outer periphery of the ribless area 6 is surrounded by a square,
It is a tube plate of a heat exchanger in which a groove-shaped deformed portion 7 thinner than other portions is formed. The present invention described in claim 3 is:
3. The tube plate of the heat exchanger according to claim 1, wherein the thickness of the flat surface in the ribless area 6 is smaller than that of the other.

[0006]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of a main part of a tube plate of the present invention, and FIG. 2 is a perspective view of a main part of a heat exchanger using the tube plate. This tube plate closes the opening of the tank body 1 made of resin, has an annular groove formed on the outer peripheral edge, and its outer wall is raised, and a claw 9 is formed on the raised edge. Have been. A large number of flat holes 2 are arranged at regular intervals on the plane of the tube plate 4 with their major axes located in the width direction.
Except for both ends of the tube plate, reinforcing vertical ribs 5 are formed between the flat holes 2. Then, rib-free areas 6 are arranged at both ends in the longitudinal direction of the tube plate 4. Then, one end of the flat tube 3 is inserted into each of the flat holes 2, and the inserted portion is liquid-tight brazed and fixed. The bottom of the tank body 1 is fitted into the annular groove of the tube plate 4 via an O-ring, and the claw 9 on the outer periphery of the tube plate is bent, so that a small not-shown provided on the opening edge of the tank body 1 is provided. The tube plate is swaged and fixed to the flange portion in a liquid-tight manner.

The fins are provided between the flat tubes 3.
11 are located. Then, high-temperature engine cooling water flows from the left tank body 1 to the right-hand side (not shown) through the respective flat tubes 3, and the flat tubes 3 and the fins
Cooling air flows through the outer surface of 11. This tube plate 4
The intermediate portion has high rigidity due to the presence of the vertical ribs 5, and is hardly deformed even when an external force is applied near the root of the flat tube 3 and the flat hole 2. However, since the vertical ribs 5 do not exist in the rib-free areas 6 formed at both ends in the longitudinal direction of the tube plate 4, they are easily deformed when an external force is applied. And by the cooling air flowing through the core,
Both ends in the longitudinal direction of the tube plate 4 tend to be relatively easy to cool, and the middle part tends to be hard to cool. Therefore, the thermal expansion of the flat tubes 3 located at both ends in the longitudinal direction of the tube plate 4 is smaller than that of the other portions, and stress is generated between them. At this time, the ribless area 6 is relatively easily deformed, and absorbs the distortion so that the stress does not become excessive.

FIG. 3 shows another embodiment of the present invention. In this embodiment, a thin groove-shaped deformed portion 7 is formed so as to surround the ribless area 6 and the ribless area 6 is formed. The plane is formed thinner than other planes.
FIGS. 4 and 5 show the cross-sectional view and the mounting state of the tube. As is clear from FIG. 4, the ribless area 6 and the groove-shaped deformed portion 7 are stretched more during press molding,
There it is thinned. In order to remove the work hardening accompanying the thinning of the tube plate, it is preferable that the tube plate is heated and annealed after molding to keep the hardness of each part constant. The insertion portions of the flat tubes 3 inserted into the respective flat holes 2 are brazed and fixed to each other in a liquid-tight manner. Then, the thin portion 10 of the ribless area 6 is easily deformed by the external force applied via the flat tube 3, so that excessive stress is not generated at the base of the flat tube.

[0009]

The tube plate of the heat exchanger according to the present invention has a plurality of flat holes 2 located at both ends in the longitudinal direction.
A ribless area 6 is formed between the ribless areas 6, whereby the ribless area 6 is more easily deformed in the thickness direction with respect to an external force than that of the ribbed area in the middle. Therefore, it absorbs a larger stress particularly generated at both ends in the longitudinal direction of the tube plate due to the thermal expansion, thereby preventing a crack at the root portion between the tube and the tube plate, thereby providing a highly reliable heat exchanger. That is, compared to the thermal expansion of the tube located in the middle part of the heat exchanger core, that of the tube located in the vicinity of both ends is smaller, resulting in thermal distortion, particularly with the tubes in the vicinity of both ends of the tube plate. Cracks tend to occur at the base of the tube plate, but the thermal stress is absorbed by easy deformation of the rib-free area.

Further, according to the second aspect of the present invention, the thinner groove-shaped deformed portion 7 facilitates absorption of thermal stress. Similarly, according to the third aspect of the present invention, the thickness of the flat surface in the groove-shaped deformed portion 7 is made thinner than the other, so that thermal strain can be absorbed more easily.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part of a tube plate of a heat exchanger according to the present invention.

FIG. 2 is a perspective view of a main part of a heat exchanger using the tube plate.

FIG. 3 is a perspective view of a main part of a tube plate according to another embodiment of the present invention.

FIG. 4 is a longitudinal sectional view of FIG. 3;

FIG. 5 is a cross-sectional view of a main part of a heat exchanger using the tube plate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tank main body 2 Flat hole 3 Flat tube 4 Tube plate 5 Vertical rib 6 Area without rib 7 Groove deformed part 8 Pipe 9 Claw part 10 Thin part 11 Fin

Claims (3)

[Claims] 1. A peripheral edge is joined to each of openings of a pair of elongated tank bodies 1 which are separated from each other, and the tank bodies 1
And a large number of flat holes 2 are drilled at regular intervals in the longitudinal direction and with their long axes parallel to the width direction,
Both ends of the flat tube 3 are inserted into the respective flat holes 2,
In the tube plate 4 of the heat exchanger in which the insertion portion is brazed and fixed in a liquid-tight manner, a longitudinal rib 5 for reinforcement is provided between the adjacent flat holes 2 at an intermediate portion in the longitudinal direction of the tube plate 4. A rib-free area 6 having no longitudinal rib is formed between a plurality of flat holes 2 which are bent parallel to the long axis of the flat hole 2 and are located at both ends in the longitudinal direction of the tube plate 4. Accordingly, the rib-free area 6 is formed such that deformation in the thickness direction with respect to an external force can be performed more easily than that of the ribbed area in the middle part. 2. The tube plate for a heat exchanger according to claim 1, wherein the outer periphery of the ribless area 6 is surrounded by a rectangle, and a groove-shaped deformed portion 7 thinner than other portions is formed. 3. The tube plate for a heat exchanger according to claim 1, wherein the thickness of the flat surface in the ribless area 6 is smaller than that of the other.