JP2007093103A - Core portion structure for heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the cracks or breakage of a tube at its root by relaxing thermal stress concentrating on the root of the tube. <P>SOLUTION: This core portion structure for a heat exchanger comprises a core portion 2 arranged between a pair of tanks, which consists of a plurality of tubes 7 and a plurality of fins 8. Each tube 7 is inserted and fixed at its either end through and into the corresponding tank 3(4). At the root X of the tube 7 to the tank 3 (4) outside the tank 3(4), a diameter enlarged portion 13 is provided for absorbing thermal expansion and contraction of the tube 7 in the axial direction. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a core structure of a heat exchanger for an automobile.

Conventionally, a core part of a heat exchanger in which a core part composed of a plurality of tubes and a plurality of fins is arranged between a pair of tanks, and both end parts of the respective tubes are inserted and fixed in corresponding tanks, respectively. The structure technology is known (see Patent Documents 1 to 3).
JP 2005-3226 A JP 2005-37061 A JP 2004-278867 A

  However, in the core structure of a conventional heat exchanger, the thermal stress when the tube is thermally expanded and contracted in the longitudinal direction is concentrated at the base of the tube with the tank (hereinafter abbreviated as the tube base). There was a risk of cracking or breakage.

  The present invention has been made in order to solve the above-mentioned problems, and the purpose of the present invention is to reduce heat stress concentrated on the base of the tube, thereby preventing heat exchange that can prevent cracking and breakage of the base of the tube. The core part structure of the vessel is provided.

  According to the first aspect of the present invention, a core portion composed of a plurality of tubes and a plurality of fins is disposed between a pair of tanks, and both end portions of the respective tubes are inserted into the corresponding tanks. In the core part structure of the heat exchanger to be fixed, a diameter-enlarged part capable of absorbing thermal expansion and contraction in the axial direction of the tube is provided outside the tank at the base of the tube in the tube.

  According to the first aspect of the present invention, a core portion composed of a plurality of tubes and a plurality of fins is disposed between a pair of tanks, and both end portions of each tube correspond to each other. In the core part structure of the heat exchanger that is inserted and fixed in the tube, the diameter of the tube is increased on the outer side of the tank at the base of the tube, so that it can absorb thermal expansion and contraction in the axial direction of the tube. Thermal stress at the time of thermal expansion / contraction in the longitudinal direction can be relieved by the enlarged diameter portion, thereby preventing cracks / breakage at the base of the tube.

  Embodiments of the present invention will be described below with reference to the drawings.

Example 1 will be described below.
In the first embodiment, a case where the heat exchanger is applied to a radiator will be described.
1 is a perspective view of a heat exchanger according to a first embodiment of the present invention, FIG. 2 is a front view of a core portion according to the first embodiment, and FIG. 3 is an exploded perspective view of a core portion and a tank according to the first embodiment (partial). 4 is an end view taken along line S4-S4 in FIG. 1, FIG. 5 is an end view for explaining the end of the tube of the first embodiment, and FIG. 6 is a case where the expanded width W1 of the expanded portion is changed. FIG. 7 is a diagram illustrating a tube in which the width W1 of the enlarged diameter portion is further increased.

First, the overall configuration will be described.
As shown in FIG. 1, the radiator 1 in which the core structure of the heat exchanger according to the first embodiment is employed includes a core 2 and tanks 3 and 4.

  As shown in FIG. 2, the core portion 2 includes a pair of tube plates 5 and 6 that are constituent members of tanks 3 and 4 described later, and a plurality of tubes 7 that are alternately arranged between the tube plates 5 and 6. In addition, a wave-like fin 8 and a pair of reinforcements 9 and 10 that connect both ends of the tube plates 5 and 6 are provided.

  As shown in FIG. 3, the tube plates 5 and 6 are fitted with an end 7a of a tube 7 to be described later, and the bottom periphery of the corresponding tanks 3 and 4 is crimped to the dish-shaped periphery. A plurality of claw portions 11 that can be fixed are projected.

The tube 7 employs a so-called B-type flat tube having a column 12 at the center thereof, and its end 7a is brazed and fixed in a state where the end 7a is inserted through and fixed to the corresponding through holes of the tube plates 5 and 6, respectively. Has been.
Note that the through holes of the tube plates 5 and 6 may be formed in a cylindrical shape inside the tank 3 (4). Moreover, the column part 12 does not necessarily need to be provided.

And as shown in FIG. 4, the diameter-expanded part 13 expanded in diameter is provided in the both ends of the tube 7 at the tank 3 (4) outer side of the base X of the tube.
Moreover, as shown in FIG. 5, the enlarged diameter part 13 is formed in the cross-sectional shape expanded outside in the substantially semicircle shape, However, It is not limited to this cross-sectional shape.

  The fins 8 are for exchanging heat with the vehicle running wind or the forced wind of a fan (not shown), and the fins 8 employ so-called corrugated fins that are formed in a wave shape. Are both brazed and fixed in contact with each other.

  The reinforcements 9 and 10 are for connecting and reinforcing both end portions of the tube plates 5 and 6, and both end portions 14 are fitted and fixed in the corresponding through holes of the tube plates 5 and 6. It is fixed by brazing.

The bottom of the tank 3 is closed by the tube plate 5 via the seal member S, and the port P1 projects from the vehicle rear side in communication with the internal space.
On the other hand, the tank 4 is similarly closed by the tube plate 6 via the seal member S, and the port P2 projects from the vehicle rear side in communication with the internal space.

  In addition, in the radiator, the tanks 3 and 4 (excluding the tube plates 5 and 6) are made of resin, the constituent members of the core portion 2 are made of aluminum, and at least of the joint portions of the constituent members of the core portion 2 On one side, a clad layer (brazing sheet) is provided.

Next, the operation will be described.
When manufacturing the radiator 1 configured as described above, first, the constituent members of the core portion 2 are temporarily assembled, and then heat-treated in a heating furnace (not shown) to braze the constituent members integrally. Fix it.

At this time, the diameter-expanded portion 13 can be easily formed by forming a groove to be the diameter-expanded portion 13 in advance in the metal plate material before the step of bending into a B-shaped flat shape when the tube 7 is manufactured.
Further, when the tube 7 is inserted and fixed to the tube plates 5 and 6, the tube 7 is simply operated by bringing the enlarged diameter portions 13 into contact with the corresponding tube plates 5 and 6 at both ends of the tube 7. The insertion margin of the end portion 7a can be easily positioned, and the core portion 2 can be temporarily assembled with high accuracy.

  Next, the claw portions 11 of the tube plates 5 and 6 are fixed by caulking to the corresponding peripheral edges of the bottoms of the tanks 3 and 4 via seal members S (not shown) (see FIG. 4). The manufacture of the radiator 1 is manufactured in an airtight state.

  In the radiator 1 configured as described above, after the ports P1 and P2 are connected to the connection pipe on the engine side, the circulation medium at around 110 ° C. flowing into the tank 3 from the engine side via the port P1 is transferred to each tube 7. After being cooled to about 80 ° C. by exchanging heat with the vehicle traveling wind passing through the core portion 2 while flowing into the tank 4 via the air or the forced air of the fan (not shown) and then cooling to the engine side via the port P 2 It is discharged again and functions as a radiator.

  Here, each tube 7 is thermally expanded / contracted mainly in the longitudinal direction, and the thermal stress generated at that time may concentrate on the root of the tube 7 and may be cracked / damaged.

  On the other hand, in the core part structure of the heat exchanger according to the first embodiment, when the tube 7 is thermally expanded / contracted in the longitudinal direction, the enlarged diameter portion 13 is thermally expanded / contracted in the longitudinal direction of the tube 7. Thus, it functions like a damper, thereby absorbing and relaxing the thermal stress applied to the base of the tube 7 and preventing cracks and breakage.

  Here, the stress value applied to the root X of the tube when the expanded width W1 in the expanded diameter portion shown in FIG. 5 is changed to various values is calculated, and the stress reduction rate effect compared with the case where the expanded diameter portion is not provided. The result of calculating is shown in FIG. In addition, the tube assumed the tube of general width and thickness, and the length W2 of the diameter expansion part was 5 mm.

As shown in FIG. 6, a stress reduction effect of about 20% to 80% can be obtained when the expanded diameter width W1 is 0.2 mm to 1.5 mm, compared with the case where the expanded diameter portion is not provided, which is preferable. I found it.
In consideration of the increase in the resistance of the flow medium with the increase in the expanded width W1, the expanded width W1 is sufficiently set to 0.2 mm to 0.5 mm (stress reduction effect is about 20% to 50%). Effects can be obtained.
Further, as shown in FIG. 7, when the length W2 of the enlarged diameter portion is increased, a linear portion is formed, and this portion is thermally expanded / contracted, and thermal stress concentrates on the root of the tube 7, The length W2 of the enlarged diameter portion is preferably 5 mm or less.

Next, the effect will be described.
As described above, in the core part structure of the heat exchanger according to the first embodiment, the core part 2 including the plurality of tubes 7 and the plurality of fins 8 is disposed between the pair of tanks. In the core part structure of the heat exchanger in which both ends of each tube 7 are inserted and fixed to the corresponding tank 3 (4), the tank 3 (4) at the base X with the tank 3 (4) in the tube 7 Since the enlarged diameter portion 13 capable of absorbing thermal expansion and contraction in the axial direction of the tube 7 is provided on the outside, the thermal stress when the tube 7 is thermally expanded and contracted in the longitudinal direction can be relaxed by the enlarged diameter portion 13. Thereby, the crack and damage of the base of the tube 7 can be prevented.

Although the present embodiment has been described above, the present invention is not limited to the above-described embodiment, and design changes and the like within the scope not departing from the gist of the present invention are included in the present invention.
For example, although the case where the heat exchanger is applied to the radiator 1 has been described in the first embodiment, the heat exchanger may be applied to a capacitor. The tanks 3 and 4 may all be made of aluminum.
Further, in the first embodiment, the enlarged diameter portions 13 are formed at both end portions of all the tubes 7.

  Moreover, as shown in FIG. 8, you may form the enlarged diameter part 20 which connected multiple enlarged diameter parts 13 (two in the figure). However, the desired effect cannot be obtained if the enlarged diameter portions are separated from each other.

It is a perspective view of the heat exchanger of Example 1 of this invention. It is a front view of the core part of the present Example 1. FIG. It is a disassembled perspective view (only a part) of the core part of this Example 1, and a tank. It is an end elevation in S4-S4 line of FIG. It is an end view explaining the edge part of the tube of the present Example 1. FIG. It is a figure which shows the stress value at the time of changing diameter expansion width W1 of an enlarged diameter part. It is a figure explaining the tube which made width W1 of an enlarged diameter part larger. It is an end elevation explaining the edge part of the tube of another Example.

Explanation of symbols

X Tube base P1, P2 Port S Seal member 1 Radiator 2 Core portion 3, 4 Tank 5, 6 Tube plate 7 Tube 7a (tube) end portion 8 Fin 9, 10 Reinforce 11 Claw portion 12 Column portion 13 Diameter expansion Part 14 End

Claims (1)

Between the pair of tanks, a core portion composed of a plurality of tubes and a plurality of fins is disposed,
In the core portion structure of the heat exchanger in which both end portions of each tube are inserted and fixed in corresponding tanks,
A core part structure of a heat exchanger, characterized in that an enlarged diameter part capable of absorbing thermal expansion and contraction in the axial direction of the tube is provided outside the base of the tank in the tube.

Images