JP2002235996A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat exchanger capable of improving the feedable performance of an adhesive without being affected by the variations in the viscosity and the setting temperature of the adhesive and the like. SOLUTION: A heat exchanger has a core plate 140 that is coupled with the open end surfaces 111 and 121 of tanks 110 and 120, and the end 151 of a tube 150 is fitted in a hole 141 provided in this core plate 140. The circumference of the fit part 160 of the tube 150 is sealed by a thermosetting adhesive 170. In such a heat exchanger, a plate surface 142 provided with the hole 141 is provided with a tilt 143 that is tilted to a virtual surface orthogonal to the longitudinal direction of the tube 150. The adhesive 170 has such a property that its viscosity drops once due to the rise in temperature and increases afterwards. Moreover, the tilt part 143 is tilted in the major axis direction of the cross section of the tube 150.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger suitable for use in a machine-assembled heat exchanger in which a gap between a core plate and a tube is sealed with an adhesive. It is about.

[0002]

2. Description of the Related Art As a conventional heat exchanger, as shown in FIG. 5 (a), an end 151 of a tube 150 is fitted into a burring hole 141 of a core plate 140, and is crimped by pipe expansion. There is known a method of applying an adhesive 170 to 160 and sealing it (see, for example,
No. 0-160385).

[0003] The adhesive 170 used here is used.
Is a rubber-based thermosetting adhesive with excellent heat resistance, chemical resistance such as antifreeze components and rust prevention components, and more specifically, a silicone rubber-based adhesive. The sealing property of the part 160 is ensured.

[0004]

However, if the flowability of the adhesive 170 is reduced due to variations in the viscosity characteristics of the adhesive 170 or variations in the temperature at which the adhesive is cured, as shown in FIG. As described above, the applied adhesive 170 may not sufficiently cover the entire periphery of the fitting portion 160, and the sealing property cannot be secured.

An object of the present invention is to provide a heat exchanger which can improve the adhesive property without being affected by variations in the viscosity and curing temperature of the adhesive.

[0006]

The present invention employs the following technical means to achieve the above object.

According to the first aspect of the present invention, the core plate (14) connected to the open end faces (111, 121) of the tanks (110, 120) serving as the entrance and exit of the heat exchange fluid.
0), and the end (151) of the tube (150) is fitted into the hole (141) provided in the core plate (140) so as to communicate with the inside of the tank (110, 120), and is thermoset. Tube (15)
In the heat exchanger that seals around the fitting portion (160) of (0), the plate surface (142) provided with the hole (141) has a virtual surface orthogonal to the longitudinal direction of the tube (150). It is characterized in that an inclined portion (143) that is inclined with respect to that is provided.

Accordingly, if the adhesive (170) is supplied from the higher side of the inclined portion (143), the adhesive (170) easily flows to the lower side by the inclined portion (143) in the curing process. In addition, the turning property to the fitting portion (160) can be improved.

Incidentally, as in the second aspect of the present invention, the viscosity of the adhesive (170) once decreases as the temperature rises.
After that, if it has the property of increasing viscosity,
Since the adhesive (170) itself flows more easily in the curing process, it is possible to promote the turning to the fitting portion (160) in addition to the function and effect of the inclined portion (143).

Further, as in the invention according to claim 3, the cross section of the tube (150) is made flat,
If the inclined portion (143) is inclined in the longitudinal direction of the cross section of the tube (150), the flow resistance of the adhesive (170) to the tube (150) can be reduced.
The turning property to the fitting part (160) can be improved.

The reference numerals in parentheses of the above-mentioned means indicate the correspondence with the specific means described in the embodiments described later.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIGS. 1 to 3 show a first embodiment of the present invention. The first embodiment is applied to a mechanically assembled radiator for an automobile.
The overall structure and the structure near the tube end will be described.

A mechanically assembled radiator (hereinafter referred to as a radiator) 100 is roughly divided into a core portion 101 for exchanging heat between cooling water and cooling air (outside air) and an upper tank 11.
0, a lower tank 120.

The core section 101 comprises a tube 150, plate fins 180, and upper and lower core plates 140. Here, these members 15 of the core portion 101 are used.
Each of 0, 180, and 140 is formed of a metal having excellent thermal conductivity, corrosion resistance, and the like, specifically, an aluminum alloy.

The tube 150 is formed by shaping a circular pipe material into a predetermined length in a flat cross section by roller processing. Both ends 151 have flat burring holes 141 formed in upper and lower core plates 140, which will be described later. It is fixed by crimping. Here, the burring hole 141 has a flange portion extending from the edge of the flat hole shape toward the inside of the tank portion (water side). Further, both ends 151 of the tube 150 communicate with the internal spaces of the upper tank 110 and the lower tank 120.

The tube 150 is arranged so that the major axis direction of the tube 150 having a flat cross section and the flow direction of the cooling air (see FIG. 2 and FIG. 1 are perpendicular to the paper surface) are parallel to each other. A plurality of tubes 150 are arranged side by side at predetermined intervals in the left-right direction in FIG. Incidentally, the ratio (L1 / L2) of the dimension (L1) in the long axis direction to the dimension (L2) in the short axis direction of the flat shape of the cross section of the tube 150 is 2 to 5.
It is preferable to reduce the pressure loss on the air side in the core portion 101, to improve the heat exchange efficiency, to improve the pipe expanding workability, and the like.

On the other hand, the fins 180 are formed by pressing a thin strip of sheet material one by one so as to form a horizontally long rectangle by pressing, and a plurality of fins 180 are formed in a predetermined number in the vertical direction (tube longitudinal direction) in FIG. The layers are stacked at intervals (a so-called fin pitch). The interval between the fins 180 is set and held by a protruding piece (not shown) integrally formed with the fin 180 itself. The fin 180 has a flat burring hole (not shown) corresponding to the flat tube 150, and the tube 150 is inserted into the burring hole. The part is fixed by crimping to the tube 150. A well-known louver (not shown) is formed on the fin 180 at an angle to enhance heat transfer.

The upper and lower core plates 140 are formed by pressing a plate material so that the overall shape forms a horizontally long rectangle. As shown in FIG. 2, a groove 144 for inserting a packing 130 as a seal member is formed on the outer edge side. Groove 144
Are formed along the four sides of the outer edge of the core plate 140 and have one connected shape. Core plate 1
A plurality of claw pieces 145 for caulking are formed over the entire periphery at the tip of the outer edge of the forty.

The tube 1 is inserted into the burring hole 141.
The adhesive 170 is inserted from the air side (the upper side in FIG. 2) of the plate surface 142 into the fitting portion 160 into which the end 151 of the 50 is fitted.
Is applied to form the core portion 101.

Here, the adhesive 170 is a rubber-based adhesive excellent in heat resistance, chemical resistance to antifreeze components, rust-preventive components, and the like, and more specifically, a low-temperature-curable silicone-based adhesive. And have viscosity characteristics as shown in FIG. That is, when a predetermined temperature is applied to the adhesive 170, the adhesive 170 itself eventually cures and adheres to the target object with the rise in temperature of the adhesive 170 itself.
It has characteristics such that the viscosity temporarily decreases from the value of the initial viscosity B (here, 50 Pa · s or less is selected) (C region), and then the viscosity increases again (D region).

The upper tank 110 and the lower tank 120 are
Both are made of a resin material having excellent heat resistance, strength resistance and the like, such as nylon containing glass fiber, and the opening end faces 111, 1
21 are formed in a box shape. Upper tank 1
An inlet pipe 112 for injecting cooling water from the engine, a water inlet 114, and the like are integrally formed in the water inlet 10, and a well-known pressure cap 190 is detachably attached to the water inlet 114. Further, an outlet pipe 122 through which cooling water flows out is formed integrally with the lower tank 120.

The packing 130 is made of a rubber-based elastic material, and is inserted into the groove 144 of the core plate 140. Then, the opening end faces 1 of the upper and lower tanks 110 and 120
11 and 121 are placed on the packing 130, and the claw pieces 145 of the core plate 140 are opened.
The packing 130 is elastically compressed by being caulked and fixed on the first step portions 113 and 123 by press working.

Next, the structure of the core plate 140 in the first embodiment will be specifically described.

As shown in FIG. 2, the plate surface 142 provided with the burring holes 141 has a long axis direction (the cooling air flow direction) Inclined part 1 inclined to)
43 (portion indicated by the inclination angle θ) is formed over the entire area between the two groove portions 144. Then, as described later, the side (the left side in FIG. 2) which becomes a high position in the inclined portion 143 is set to the injection side of the adhesive 170.

Next, a method of assembling the heat exchanger according to the present embodiment will be described.

First, a predetermined number of fins 180 formed one by one by press working are laminated at a predetermined interval in the vertical direction in FIG. 1, and the tube 150 is inserted into each burring hole (not shown) of the fin 180. .

Next, by inserting a jig (not shown) for expanding the tube into the tube 150 and expanding the tube 150, the outer peripheral surface of the tube 150 is placed on the inner wall surface of each burring hole flange of the fin 180. Crimp and tube 1
The fin 180 is fixed to 50.

Next, the upper and lower ends 151 of the tube 150
Are inserted into the burring holes 141 of the upper and lower core plates 140, respectively, and a jig (not shown) for expanding the tube is inserted into the upper and lower ends 151 to expand the tube (mouth expansion). 151 is pressed against the inner wall surface of the flange of the burring hole 141, and the upper and lower ends 151 of the tube 150 are
Is fixed to the core plate 140.

Next, in order to sufficiently draw out the adhesive strength of the adhesive 170, the fitting portion 160 of the tube 150 and the plate surface 142 are cleaned with a predetermined cleaning liquid to clean the surfaces. Drying and degreasing are performed in a heating furnace to remove processing oil and processing oil for pipe expansion.

Next, the plate surface 1 of the core plate 140
The surface on the air side (upper surface in FIG. 2) of the
From the side that is at a higher position (the left side in FIG. 2), the adhesive 17
0 is injected into the heating furnace, and the adhesive 170 is cured.

Next, the grooves 1 of the upper and lower core plates 140
44, the packing 130 is inserted.
The upper and lower tanks 110, 120 have open end faces 111, 1
The tanks 110 and 120 are attached to the upper and lower core plates 140 such that the 21 is located. Finally, with the opening end faces 111 and 121 pressed against the packing 130, the claw 145 of the core plate 140 is attached to the opening end faces 111 and 12.
It is caulked and fixed on the first step portions 113 and 123 by press working. As a result, the upper and lower core plates 140 and the upper and lower tanks 110 and 120 are integrally connected, and the packing 130 is elastically compressed and deformed, so that the opening end surface 11
1, 121 and the groove 144 are pressed. Thus, the assembly of the entire heat exchanger is completed.

Next, the radiator 100 having the above configuration will be described.
The operation of will be described.

The engine cooling water flowing into the upper tank 110 from the inlet pipe 112 flows into the tube 150 from the upper opening of the tube 150 communicating with the upper tank 110. While passing through the tube 150, the engine cooling water exchanges heat with cooling air via the fins 180 to be cooled. After passing through the tube 150, the engine cooling water flows into the lower tank 120, flows out of the outlet pipe 122 to the outside, and returns to the engine.

The radiator 1 according to the present embodiment
00 is formed by a mechanical assembly method without using brazing as described above. However, between the core plate 140 and the tube 150, a sealing property is secured by the adhesive 170, and water leakage from the fitting portion 160 is prevented. Can be reliably prevented.
That is, in FIG. 2, by injecting the adhesive 170 from the higher side (left side) of the inclined portion 143, the adhesive 170 easily flows to the lower side by the inclined portion 143 in the curing process, and thus is fitted. The turning property to the part 160 can be improved, and the coating can be surely performed. In addition, the adhesive 170 has a region C where the viscosity is reduced as described in FIG.
, The turning property in the curing process can be further promoted in addition to the function and effect of the inclined portion 143.

As described above, the adhesive 1
Since 70 is applied, cured, and adhered, sufficient sealing properties are ensured, and water leakage can be reliably prevented.

Since the inclined section 143 is provided in the longitudinal direction of the cross section of the tube 150 having a flat cross section,
The flow resistance of the adhesive 170 to the tube 150 can be reduced, and the turning property to the fitting portion 160 can be improved.

(Other Embodiments) FIG. 4 shows a modification as another embodiment.

The inclined portion 143 does not need to be provided in the entire region between the two groove portions 144 of the core plate 140 as in the first embodiment.
(A) and (b) may be partially provided.

Thus, the step between the plate surface 142 of the core plate 140 and the bottom of the groove 144 can be reduced, so that the press workability of the core plate 140 can be improved. And since the position of the fitting part 160 can be moved to the air side (upper side) and the tube 150 can be shortened, the flow resistance of the engine cooling water and the material cost of the tube 150 itself can be reduced.

Although this embodiment has been described as a mechanically assembled heat exchanger that does not use brazing, it is also applicable to a heat exchanger formed by brazing. That is, in the brazed heat exchanger, the fitting portion 160 of the tube 150 is
Although it should be sealed by brazing, pin holes and the like may occur due to variations in gaps at the time of fitting, temperature variations in the furnace, and the like, which may lead to leakage. In such a case (such as found in a leak inspection process at the time of manufacturing a heat exchanger), such a leak is sealed by using an adhesive as a repair, and a good product is obtained. In addition, since the turning property of the adhesive can be improved, the reworking operation becomes easy, and the leakage can be surely prevented. (The rework is also performed at the time of repair in the market.) If the cross-sectional shape of the tube 150 is close to a round shape, the inclined portion 143 of the plate core 140 includes a plurality of tubes 150. It may be inclined in the direction (the left-right direction in FIG. 1).

Further, the burring hole 141 is inserted into the tank 11.
The adhesive 170 is applied on the air side (upper side in FIG. 2) of the plate surface 142, but the same effect can be obtained even if the two are reversed.

Further, in the above embodiment, the heat exchanger for cooling an automobile engine has been described. However, it is needless to say that the present invention can be widely applied to heat exchangers for other uses.

[Brief description of the drawings]

FIG. 1 is a front view showing the entire heat exchanger of the present invention.

FIG. 2 is a cross-sectional view showing a cross section taken along a line AA in FIG.

FIG. 3 is a characteristic graph showing viscosity and temperature during curing of an adhesive.

FIG. 4 is a cross-sectional view showing a variation of an inclined portion;
(A) is a first modification, and (b) is a second modification.

5A is a cross-sectional view showing a tube fitting portion of the related art, and FIG. 5B is a view taken in the direction of arrow E in FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 heat exchanger 110 upper tank (tank) 120 lower tank (tank) 111, 121 open end face 140 core plate 141 burring hole (hole) 142 plate face 143 inclined section 150 tube 151 end section 160 fitting section 170 adhesive

Claims (3)

[Claims] A tank (1) serving as an inlet / outlet of a heat exchange fluid.
A core plate (140) coupled to the open end faces (111, 121) of the core plates (140, 120); and holes (141) provided in the core plate (140).
A tube (1) having an end (151) fitted into the hole (141) and communicating with the inside of the tank (110, 120).
50) and a thermosetting adhesive (170) for sealing around a fitting portion (160) of the tube (150), wherein the plate surface (142) provided with the hole (141) is provided. )
Has a slope (143) inclined with respect to an imaginary plane orthogonal to the longitudinal direction of the tube (150). 2. The heat exchanger according to claim 1, wherein the adhesive has a characteristic that the viscosity temporarily decreases with an increase in temperature and then increases. 3. The tube (150) has a flat cross-sectional shape, and the inclined portion (143) is inclined in a longitudinal direction of the cross section of the tube (150). The heat exchanger according to any one of claims 1 to 2.