JP5393514B2 - Heat exchanger - Google Patents

Description

  The present invention relates to an air-cooled heat exchanger that is mainly mounted under the floor of an automobile or in the lower part of an engine room, particularly under an engine front.

  Conventionally, as a heat exchanger for automobiles or other uses, as shown in Patent Document 1, a heat exchanger in which corrugated fin members are arranged on a meandering tube member has been known. This heat exchanger can be made compact by forming the pipe member in a meandering manner, making it possible to lengthen the flow path of the fluid flowing through the inside of the pipe member, and by using corrugated fin members, a large number of pipe members can be used. It is possible to arrange the fins, and the heat exchange performance can be improved.

JP 2005-201622 A

  However, particularly when a heat exchanger is mounted in a narrow space such as under the floor of an automobile or in the lower part of an engine room, it is necessary to reduce the thickness in the thickness direction. As shown in FIG. 18 of Patent Document 1, since the pipe member is formed in two stages, the bulk in the thickness direction is high. Therefore, in the invention described in Patent Document 1, as means for reducing the bulk in the thickness direction, the two-stage pipe member is formed in one stage, and the formation width of the fin member in the thickness direction of the heat exchanger is shortened. It is possible to do. However, if the formation width of the fin member is made too short, the surface of the tube member assembled with the fin member is exposed to the outside of the fin member. Therefore, it becomes easy for the stepping stone from the road surface to directly hit the exposed portion of the pipe member during traveling, and when the stepping stone directly hits the pipe member, the contact portion of the pipe member is damaged and a recess is formed, There is a concern that stress concentration may occur in the concave portion due to external force due to vibration or the like, and the pipe member may be damaged.

  Accordingly, the present invention is intended to solve the above-described problems. The pipe member is formed in a meandering manner to reduce the bulk of the heat exchanger in the thickness direction, so that the floor of an automobile or the lower part of an engine room is formed. In addition, the stepping stones from the road surface are in direct contact with the pipe member and damaged during traveling, and stress concentration occurs in the recess formed by this damage due to external force due to vibration, etc. An object of the present invention is to obtain a heat exchanger capable of preventing a situation where a pipe member is damaged.

  In order to solve the above-described problems, the present invention repeatedly folds and stacks plate materials in a corrugated shape to form corrugated fins, and presses and deforms the curved portion formed by the bending processing into a concave shape. A plurality of fin members formed with engaging recesses, and a plurality of straight pipe portions arranged in parallel via the fin members and the straight pipe portions having meandering pipe members having U-shaped folded portions. The plurality of straight pipe portions of the pipe member are engaged with the engagement concave portions of the plurality of fin members. As described above, the present invention is such that a fin member formed of corrugated fins is assembled to a meandering tube member in which a plurality of straight pipe portions are integrally formed. It can arrange | position and can make manufacture easy.

Moreover, since the fin member is formed of corrugated fins, the surface area of the fin member can be increased due to the presence of the curved portions formed between the fins of the corrugated fins. Therefore, it is possible to efficiently dissipate heat from the pipe member, and heat exchange performance can be improved. In addition, by adopting the above configuration, a one-stage heat exchanger different from the two-stage heat exchanger described in Patent Document 1 is formed. Can be easily mounted under the floor.

Further, the outer diameter of the pipe member is set to 8 mm to 12 mm. When the outer diameter of the pipe member is less than 8 mm, especially when liquids such as oil, gasoline, and light oil are used as the fluid in the pipe, it becomes difficult to secure the required flow rate because the pressure loss of the fluid increases. The flow rate decreases and it becomes difficult to obtain a desired amount of exchange heat, or the pressure loss exceeds a threshold value and it becomes impossible to use. On the other hand, when the diameter is larger than 12.0 mm, the outer diameter of the pipe member becomes larger, so it becomes easier to secure the required flow rate of the fluid with the expansion of the outer diameter. The mountability in a narrow space such as under the floor or the lower part of the engine room is reduced.

Moreover, the opposing space | interval of the curved top part protruded most outward in the curved part of an adjacent fin member is 0.5-5.0 mm. In addition, the curved top part in this invention means the top part most projected in the bending width direction of the fin member in the curved part of the fin member curvedly formed by the bending process of a board | plate material. When the facing distance is larger than 5.0 mm, it is necessary to arrange adjacent fin members in the separating direction via the pipe members. Therefore, the engaging recess of the fin member is shallow and the axial width of the tube member is narrow, and the formation length in the direction perpendicular to the axial direction of the tube member is short. Since the pipe member is engaged and disposed in the mating recess, the contact area between the fin member and the pipe member becomes small, and the heat exchange performance may be lowered, and the assembly strength may be lowered.

On the other hand, when the facing distance is less than 0.5 mm, the facing distance between the adjacent fin members is narrowed, so it is difficult for stepping stones from the road surface to enter the facing distance, and the stepping stones on the surface of the pipe member during traveling. From the point of preventing the situation where the direct contact is difficult to occur, the tube member surface is damaged by stepping stones and a recess is formed, and stress is concentrated in this recess due to external forces such as vibration. Is preferred. However, in order to make the facing interval less than 0.5 mm, the protruding portions of adjacent fin members must be arranged close to each other. However, since the pipe member is located between adjacent fin members, In order to arrange the portions close to each other, it is necessary to form a deep engagement recess in the fin member, and to engage and dispose the pipe member in this deep engagement recess. Therefore, when forming a deep engagement recess, a large shear stress is applied with a large deformation, and unnecessary deformation may occur in the vicinity of the engagement recess. In the present invention, the facing interval means a disposition interval between adjacent fin members facing each other through the tube member, and in particular, an engagement recess that does not involve the tube member between both fin members. It means an interval at the curved top protruding from the fin member in the width direction.

Moreover, the protrusion height of the fin member in the width direction from the surface of the straight pipe portion of the pipe member is set to 11 mm or less. The reason for this is that if the protruding height of the fin member in the width direction is larger than 11 mm, the entire product assembled with the fin member becomes bulky, which reduces the mountability to automobiles, etc. From the calculation of the fin efficiency of the fin member shown, it became clear that a significant improvement in heat exchange performance cannot be expected. Here, the relationship between the protrusion height of a fin member and the fin efficiency regarding the heat exchange performance of a fin member is demonstrated below.

Considering the heat exchanger of the present invention as a flat plate fin having no folded curved portion for the sake of simplicity of calculation,

η = tanh (mL) / mL m≡ (2h / kδ _t ) ^1/2 × L
η: Fin efficiency (%)
k: Thermal conductivity (about 150w / mK as a standard aluminum alloy)
h: Heat transfer coefficient (bending plane perpendicular; about 60w / m ² K, bending plane parallel; about 25w / m ² K)
L: Projection height of fin member (mm)
[delta] _t: plate thickness of the fin members (0.3 mm)

The calculation was performed. A graph created based on this calculation result is shown in FIG. In addition, the said fin efficiency means the heat dissipation efficiency of the fin member which changes with the shape of a fin member, the height of a fin member, and the plate | board thickness of a fin member, and the result of FIG. It shows the change of fin efficiency when the density and the plate thickness of the fin member are constant and only the height of the fin member is changed to 3 to 13.5 mm.

As shown in Fig. 2, when the fin member's protruding height in the width direction exceeds 11mm, the fin efficiency is lower than 80%, and the heat exchange efficiency decreases, while the fin member's protruding height is 11mm or less. The fin efficiency can be secured at 80% or more, and the heat exchange efficiency can be maintained well. Therefore, in order to maintain the heat exchange efficiency of the present invention satisfactorily, the protrusion height in the width direction of the fin member needs to be 11 mm or less.

Further, as described above, after limiting the protruding height in the width direction of the fin member to 11 mm or less, the present invention sets the protruding height of the fin member within the range where the facing interval between the curved tops is 0.5 to 5.0 mm. , Y ≧ 2.46x ^−0.29 (y: projection height in the width direction of the fin member from the surface of the pipe member / opposite spacing of the curved tops, x: opposing spacing of the curved tops) . This formula is derived from the following experiment and simulation analysis.

First, in order to determine the shape of the stepping stone to be used in the simulation analysis, the facing distance t between the curved tops of the fin member is set to 2.0 mm, the plate thickness of the fin member is set to 0.3 mm, and the width direction of the fin member A stepping stone test was conducted when the projecting height L was 3 mm and 4 mm. This stepping stone test is an automotive standard JASO M 104 “Brake tube test method” (category: first category, test purpose: test method and test for the purpose of deteriorating the organic surface of the brake tube, etc. The test conditions and test equipment of the same standard are mainly as follows.
(1) Air pressure: 0.4 ± 0.03MPa
(2) Spray angle; right angle
(3) Spraying distance: 350mm
(4) Stepping stone amount; 850 g
(5) Number of times: 5 times
(6) Test equipment; Gravelometer
(7) Stepping stones: Granite (Jade gravel, size 9-15mm)

Here, the JASO method standard uses gravel with a smooth surface as a stepping stone. However, in this stepping stone test, the outer surface of the organic coating and the like is further deteriorated and a stricter evaluation test is performed. In order to carry out, evaluation was carried out using a grinding stone commercially available as a grinding stone for general cutting (a grinding stone manufactured by Chipton Co., Ltd .: product name “GT”, model number “4”). This grinding stone is an approximately regular triangular prism with a side length of about 10 mm and a height of about 8 mm, or an approximately regular triangular frustum shape and has an edge portion. It is what is used for.

The results of the stepping stone test using the above grinding stone are shown in FIGS. 3A is an enlarged plan view of the heat exchanger before the stepping stone test when the protrusion height L in the width direction of the fin member is 4 mm, and FIG. 3B is the width direction of the fin member. 6 is an enlarged plan view of the heat exchanger after the stepping stone test when the protrusion height L is 4 mm. 4A is an enlarged plan view of the heat exchanger before the stepping stone test when the protrusion height L in the width direction of the fin member is 3 mm, and FIG. 4B is the width direction of the fin member. 6 is an enlarged plan view of the heat exchanger after the stepping stone test when the protrusion height L is 3 mm.

As a result of visually confirming the surface of the pipe member when the protruding height in the width direction of the fin member was 4 mm, no flaws due to flying stones were confirmed as shown in FIG. On the other hand, when the protrusion height in the width direction of the fin member was 3 mm, as shown in FIG. 4B, a plurality of scratches caused by stepping stones were visually confirmed on the surface of the tube member. From this result, if the projecting height in the width direction of the fin member is 3 mm under the condition where the facing distance t between the curved tops of the fin member is 2.0 mm, the stepping stone directly hits the surface of the pipe member during traveling. It became clear that when the projecting height in the width direction of the fin member was 4 mm, the stepping stone hardly hit the surface of the pipe member.

And, in the stepping stone test, the test was conducted for the case where the facing interval t of the curved top portion of the fin member was 2 mm.For the influence of stepping stones at other facing intervals, simulation analysis based on the schematic diagram was conducted based on the above results. went. The simulation analysis will be described. First, in order to determine the shape of the stepping stone used for the simulation analysis, based on the above test results, a schematic diagram in the case where the facing interval t between the curved tops of the fin members is 2 mm as shown in FIG. Created. Each schematic diagram in FIGS. 5 and 6 is a schematic cross-sectional view of the heat exchanger in a direction perpendicular to the tube axis direction of the straight tube portion of the tube member. FIG. 5 (a) is a schematic diagram in the case where the protrusion height L in the width direction of the fin member is 3 mm, and FIG. 5 (b) is a case in which the protrusion height L in the width direction of the fin member is 4mm. FIG.

In the stepping stone test, when the protruding height in the width direction of the fin member is 3 mm, the stepping stone directly hits the surface of the pipe member, and when the protruding height in the width direction of the fin member is 4 mm, the pipe member Since the stepping stone did not directly hit the surface of Fig. 5, in the schematic diagram shown in Fig. 5, when the protrusion height L in the width direction of the fin member (3) is 3mm (Fig. 5 (a)), the stepping stone (21) Is in contact with the surface of the pipe member (1), and the protrusion height L in the width direction of the fin member (3) is 4 mm (FIG. 5B), the surface of the pipe member (1) The shape of the heat exchanger (20) is schematically shown so that the shortest distance P between the stepping stone and the stepping stone (21) is 1 mm.

Then, from the schematic diagram expressed in this way, as shown in FIG. 5, in this simulation analysis, the shape of the stepping stone when contacting the surface of the pipe member was determined to be an inverted triangle. In this simulation analysis, as shown in FIG. 5B, the limit value of the shortest distance between the pipe member (1) and the stepping stone (21) when the stepping stone (21) does not directly hit the pipe member (1). It was a 1mm, if the distance between the tubular member and the stepping stones in schematic view of at least 1mm or more, stepping stones are virtual constant that it will not directly hit the pipe member even when the actual traveling.

Similarly to the case where the facing distance t of the curved top as shown in FIG. 5 is 2 mm, each facing distance t and the protruding height in the width direction of the fin member when the facing distance t is 0.5 mm, 1 mm, 4 mm, and 5 mm. As shown in FIGS. 6 (a) to 6 (d), a schematic diagram was created for each facing interval, and a simulation analysis was performed. 6A and 6B are schematic views when the facing interval t is 0.5 mm in (a), the facing interval t is 1 mm in (b), the facing interval t is 4 mm in (c), and the facing interval t is 5 mm in (d). Each figure is shown. And in each said opposing space | interval t, the shortest distance P between the stepping stone (21) and the surface of the pipe member (1) is 1 mm, that is, the protrusion height L of the fin member that the stepping stone does not directly hit the pipe member. The lower limit value was determined from the schematic diagram shown in FIG.

As a result, as shown in FIGS. 6 (a) to 6 (d), the protruding height in the width direction of the fin member (3) when the distance P between the surface of the pipe member (1) and the stepping stone (21) is 1 mm. L was 1.7 mm when the facing distance t was 0.5 mm, 2.5 mm when the facing distance t was 1 mm, 7.0 mm when the facing distance t was 4 mm, and 8.5 mm when the facing distance t was 5 mm . And the protrusion height L of the fin member in each said opposing space | interval t was made into the lower limit of the protrusion height of the fin member in which a stepping stone does not directly hit the surface of a pipe member in each opposing space | interval.

Next, results of the simulation analysis, the opposing distance t of the bay Kyokuitadaki portion in the width direction of the protruding height L / fin member facing distance t and the fin member of the curved top portion of the fin member as shown in FIG. 7 The relationship is plotted and expressed as a graph. From the approximate curve of this plot, the formula: y = 2.46x ^-0.29 (y: the protruding height of the fin member in the width direction from the pipe member surface / opposite of the curved top of the fin member) The distance, x: the facing distance of the curved top of the fin member) was derived.

And as the protrusion height in the width direction of the fin member is increased, the surface of the tube member is positioned inward of the fin member. Therefore, the protrusion height in the width direction of the fin member is y ≧ 2.46x ^−. If the relationship ^0.29 (y: protrusion height in the width direction of the fin member from the surface of the tube member / opposite spacing of the curved apex of the fin member, x: opposing spacing of the curved apex of the fin member) It can be said that it is difficult to directly contact the surface of the member. On the other hand, in the range where the facing distance of the curved top portion of the fin member is 0.5 to 5.0 mm, y <2.46x ^−0.29 (y: the protruding height of the fin member in the width direction from the pipe member surface / curved top portion of the fin member , X: facing distance of the curved apex of the fin member), the protrusion height in the width direction of the fin member is insufficient, the distance from the fin member to the surface of the tube member is small, and the stepping stone is directly It will be easy to hit.

The fin member may have a plate thickness of 0.2 mm to 0.5 mm. When the plate thickness is less than 0.2 mm, the fin member becomes thin, so the heat capacity of the fin becomes poor, the temperature of the fin decreases rapidly, the heat exchange efficiency decreases, and the strength of the fin decreases. The stepping stones easily come into contact with the surface of the pipe member. When the thickness is greater than 0.5 mm, although the strength is improved, the heat exchange efficiency is somewhat improved, but a significant improvement cannot be expected, so the material is wasted.

  Further, the fin member may have a fin arrangement interval of 1.6 mm to 2.2 mm formed by bending. In addition, the arrangement | positioning space | interval of the said fin means the separation distance of the pipe axis direction of the straight pipe part of the tube member between adjacent fins in the several fin part formed in the fin member by the bending process. is there. The numerical range of the fin arrangement interval of 1.6 mm to 2.2 mm is based on the following cooling performance test results. To explain this cooling performance test, first, the plate thickness of the aluminum alloy fin member is 0.3 mm, the tensile strength of mechanical properties is 200 MPa, and the fin spacing is 1.6 mm, 2.0 mm, 2.3 mm, A heat exchanger was created for each arrangement interval using fin members of 3.2 mm and 4.0 mm, respectively.

Then, in a cylindrical wind tunnel having a square cross section, the heat exchangers with different fin arrangement intervals are installed so as to be parallel to the direction of the wind received when the vehicle is mounted (not vertical, which is a general method of installing heat exchangers). At the same time, water was circulated through the pipe member of the heat exchanger, and the temperature of water flowing into the heat exchanger and the temperature of water passing through the heat exchanger were measured. The measurement conditions at this time are as follows.
Water inlet temperature 70 ° C constant air flow inlet temperature 20 ° C constant water flow rate 1.5 ~ 2.5L / min
Air flow velocity 2.5 ~ 5.5m / s

Then, in each heat exchanger measured under the above measurement conditions, the temperature of the inlet and outlet temperatures of water that is the fluid in the pipe and the air that is the fluid between the fins, and the temperature difference between the two temperatures are respectively calculated. Was converted into a temperature difference when light oil was used instead of water, and the converted temperature difference was defined as a fluid drop temperature when passing through the heat exchanger of the present invention. The conditions for the conversion are as follows.
Light oil inlet temperature 100 ° C
Air flow inlet temperature 50 ℃
Light oil flow rate 0.75L / min
Air flow velocity 5m / sec

Then, the relationship between the drop temperature of the fluid in the pipe of each heat exchanger obtained in this way and the arrangement interval of the fins of each heat exchanger was plotted and represented by a graph as shown in FIG. From FIG. 8, it was found that the temperature drop of the fluid in the pipe exceeds about 10 ° C. when the arrangement interval is in the range of 1.6 mm to 2.2 mm. From this result, in the range where the fin arrangement interval is 1.6 mm to 2.2 mm, the drop temperature of the fluid in the pipe accompanying the passage to the heat exchanger shows a higher value compared to other arrangement intervals. In order to maintain good heat exchange performance, it is preferable that the fin spacing be in the range of 1.6 mm to 2.2 mm. When the fin arrangement interval is less than 1.6 mm, the surface area of the fin member increases, but the arrangement interval becomes too narrow, so that the flow resistance increases and the fluidity of the fluid passing through the fin member deteriorates. Heat exchange performance will be reduced, and if it is wider than 2.2 mm, the flow resistance will decrease and flow will be easier, but the surface area of the fin member will be smaller, so in this case the heat exchange performance will also be reduced. To be.

  Since the present invention is configured as described above, and the fin member formed as a corrugated fin is engaged with the meandering tube member, the manufacturing can be facilitated, and the fin member The surface area of the tube member can be increased, and the heat from the tube member can be efficiently radiated. In addition, by forming such a heat exchanger within the range of the configuration and dimensions described above, it is possible that the stepping stone from the road surface directly hits the surface of the pipe member during traveling without impairing good heat exchange performance. The abutting part of the tube member is damaged and a recess is formed. In this recess, stress concentration due to external forces such as vibration occurs, and the risk of damaging the tube member can be eliminated, and the bulk of the product in the thickness direction can be reduced. Can be low. Therefore, it is possible to improve the mountability in a narrow space under the floor of an automobile or at the lower part of the engine room, particularly under the engine front.

The perspective view which shows Example 1 of this invention. The graph which shows the relationship between the protrusion height of the width direction of a fin member, and fin efficiency. (a) The partial plane enlarged photograph which shows the state of the heat exchanger before a stepping stone test in case the protrusion height of the width direction of a fin member shall be 4 mm. (b) The partial plane enlarged photograph which shows the state of the heat exchanger after a stepping stone test in case the protrusion height of the width direction of a fin member shall be 4 mm. (a) The partial plane enlarged photograph which shows the state of the heat exchanger before a stepping stone test when the protrusion height of the width direction of a fin member is 3 mm. (b) The partial plane enlarged photograph which shows the state of the heat exchanger after a stepping stone test when the protrusion height of the width direction of a fin member is 3 mm. The schematic diagram used for the simulation analysis of facing space | interval t = 2 of the curved top part of a fin member. The schematic diagram used for each simulation analysis of facing space | interval t = 0.5,1,4,5 of the curved top part of a fin member. The graph showing the relationship between the opposing space | interval of the curved top part of a fin member, the protrusion height of the width direction of a fin member / the opposing space | interval of the curved top part of a fin member, and its approximated curve. The graph showing the relationship between the arrangement | positioning space | interval of a fin, and the fall temperature of the fluid in the pipe | tube which passed the heat exchanger. FIG. 3 is a perspective view illustrating a fin member according to the first embodiment. The AA line partial expanded sectional view of FIG. The BB line partial expanded sectional view of FIG.

  The first embodiment of the present invention will be described. (1) is a pipe member formed of an aluminum alloy. As shown in FIG. 1, a plurality of straight pipe portions (2) are inserted into fin members (3) at intervals ( 4), the end portion of the straight pipe portion (2) is curved, and this curved portion is a U-shaped folded portion (5). By forming the pipe member (1) meandering in this manner, a plurality of insertion intervals (4) of the fin members (3) are preferably formed in parallel. In each insertion interval (4), a fin member (3) is engaged and arranged. In this embodiment, the outer diameter r of the pipe member (1) shown in FIG. 11 is 8 mm. In this embodiment, the pipe member (1) is formed of an aluminum alloy as described above. However, in other different embodiments, the pipe member (1) is made of steel, stainless steel, copper, copper alloy, It is also possible to form with titanium, titanium alloy or the like.

The fin member (3) is formed of a flat strip made of aluminum alloy having a plate thickness of 0.3 mm, and the strip is formed into a corrugated shape having a constant folding height as shown in FIG. The corrugated fins are bent. Thus, by using the corrugated fin as the fin member (3), a large number of flat fins (7) are integrally formed via the curved portion (6) formed by bending. . In this embodiment, the arrangement interval (18) q of the fins (7) shown in FIG. 10 is set to 2.0 mm. Therefore, by forming the fin member (3) as described above, it becomes easy to arrange a large number of fins (7) on the pipe member (1) at equal intervals and in parallel, and the large number of fins (7). And a large number of curved portions (6), the surface area of the fin member (3) can be widened to easily produce a product with high heat exchange performance. Further, the presence of the curved portion (6) makes the fin member (3) three-dimensional and has a structurally stable integrated structure, which improves the impact resistance and increases the durability of the heat exchanger (20). It becomes possible to improve. In this embodiment, the fin member (3) is formed of an aluminum alloy. However, in other different embodiments, the fin member (3) is formed of steel, stainless steel, copper, copper alloy, titanium, titanium alloy, or the like. Is also possible.

Further, in the fin member (3) formed as described above, the curved top portion (15) that protrudes outwardly out of the curved portion (6) that is curved is pressed and deformed into a concave shape, thereby being shown in FIG. Thus, an arcuate engagement recess (8) is formed. The shape of the engaging recess (8) is such that the outer peripheral surface (10) of the pipe member (1) can be brought into surface contact with the outer peripheral surface (10) of the pipe member (1) as shown in FIGS. ).

Then, with the pipe member (1) engaged with the engaging recess (8), as shown in FIG. 1, the fin members (3) are inserted into the insertion intervals (4) between the pipe members (1). ) Are inserted and arranged. As shown in FIG. 1, a pair of end cover members (11) and side cover members (12) are disposed at both ends and both ends of the tube member (1) on which the fin member (3) is disposed as described above. ), And both end portions (13) of the pipe member (1) project from the one end cover member (11). Brackets (14) for assembling the heat exchanger (20) of this embodiment under the floor of the vehicle are formed on both sides of the end cover member (11).

Since the heat exchanger (20) of the present embodiment has a simple configuration in which the fin member (3), which is a corrugated fin, is engaged with the pipe member (1) as described above, it is easy to manufacture. In addition to the large surface area of the fin member (3), the fin member (3) can efficiently dissipate heat from the pipe member (1), and the heat exchange performance can be easily improved. It is. Further, since the fin members (3) are arranged in parallel in one stage as shown in FIG. 1, the thickness of the heat exchanger (20) is different from the two-stage heat exchanger described in Patent Document 1. It becomes possible to reduce the bulk of the direction. Therefore, the mountability in a narrow space such as under the floor of an automobile can be improved.

Further, since the arrangement interval (18) q of the fins (7) is set to 2.0 mm, as shown in FIG. 8, the lowered temperature of the fluid in the pipe that has passed through the heat exchanger (20) is higher than that of other arrangement intervals. Therefore, the heat exchanger (20) having excellent heat exchange performance can be obtained. Moreover, the opposing space | interval (17) t of the curved top part (15) in the protrusion part (16) from the pipe member (1) surface of the adjacent fin member (3) shown in FIG. 11 is 2 mm. And the protrusion height L of the fin member (3) in the width direction from the surface of the pipe member (1) shown in FIG. 10 is 4 mm, and the relationship with the facing interval (17) t = 2 mm of the curved top (15). Y ≧ 2.46x− ^0.29 (y: protrusion height L of the fin member (3) in the width direction from the surface of the pipe member (1) / opposite distance (17) t of the curved top (15), x: curved top The formula of (15) facing interval (17) t) is established.

The stepping stone test was conducted in the heat exchanger (20) of the present example prepared as described above. This stepping stone test was carried out in accordance with the automobile standard JASO M 104 “Brake tube test method”, assuming that road stones are rolled up by wheels and come in contact with the vehicle while the vehicle is running. The test conditions of the stepping stone test of this example are as follows.
(1) Air pressure; 0.4 ± 0.03MPa
(2) Spray angle; right angle
(3) Spraying distance: 350mm
(4) Amount of stepping stones; 850g
(5) Number of times: 5 times
(6) Test equipment: Gravelometer (Suga Test Instruments Co., Ltd., JA400 Stepping Stone Tester)
(7) Stepping stone: Product name “GT” Model No. “4” (Chipton Co., Ltd .: with an edge, approximately 10 mm on a side and approximately 8 mm in height, used for polishing work) (Plate pyramid shaped grinding stone)

  Then, the surface condition of the fin member (3) and the pipe member (1) after the stepping stone test was visually confirmed. The surface state of the fin member (3) and the pipe member (1) after the test is shown in the photograph of FIG. From FIG.3 (b), since the fin member (3) was in the state which each fin (7) was distorted by directly hitting a stepping stone, it has confirmed that it received the big damage by a stepping stone. However, on the surface of the pipe member (1), scars that were considered to be caused by contact with stepping stones were hardly confirmed. From these results, by creating the heat exchanger (20) with the dimensions of the present embodiment, it is possible to prevent damage to the pipe member (1) due to stepping stones without impairing good heat exchange performance. Thus, the product life can be kept long.

  In this embodiment, the engaging portion (22) between the fin member (3) and the pipe member (1) is not brazed, bonded, or painted, but in other different embodiments, The joint portion (22) and / or the vicinity thereof are brought into close contact with the fin member (3) and the pipe member (1) in the engagement portion (22) by means such as brazing, adhesion, or painting. May be. As described above, when the fin member (3) of the engaging portion (22) and the pipe member (1) are brought into close contact with each other by the above means, a gap is generated in the engaging portion (22), and moisture enters the gap. Since it is possible to prevent the fin member (3) and the pipe member (1) from corroding, it is possible to obtain excellent corrosion resistance in the engaging portion (22). Further, since the pipe member (1) and the fin member (3) are always kept in close contact with each other, heat exchange between the pipe member (1) and the fin member (3) can be performed efficiently, The exchange performance can be further improved.

DESCRIPTION OF SYMBOLS 1 Pipe member 2 Straight pipe part 3 Fin member 5 Folding part 6 Curved part 7 Fin 8 Engagement recessed part 15 Curved top part 16 Projection part 17 Opposite space | interval 18 Arrangement | positioning space | interval

Claims (3)

A plate material is bent into a corrugated shape to form a corrugated fin, and a plurality of fin members in which a curved portion formed by bending is pressed and deformed into a concave shape to form an engaging concave portion, and the fin member is interposed therebetween. A plurality of straight pipe portions are arranged in parallel, and the straight pipe portions are composed of meandering pipe members connected by U-shaped folded portions, and the plurality of straight pipe portions are connected to the plurality of fin members. In the state engaged with the engaging recess of the tube member, the outer diameter of the tube member is 8 mm to 12 mm, and the facing interval of the curved top portion that protrudes most outward in the curved portion of the adjacent fin member is 0.5 to 5.0 mm, and When the protrusion height of the fin member from the surface of the straight pipe portion is 11 mm or less and the facing interval is in the range of 0.5 to 5.0 mm, y ≧ 2.46x ^−0.29 (y: pipe member surface From the height of the fin member in the width direction / curved top Kicking opposing distance, x: the heat exchanger, characterized in that the formula of the facing distance) of the curved top portion is a value which satisfies. The heat exchanger according to claim 1, wherein the fin member has a thickness of 0.2 mm to 0.5 mm. The heat exchanger according to claim 1 or 2, wherein the fin member has an interval between fins of 1.6 mm to 2.2 mm.

Images