CORRUGATED FIN AND HEAT EXCHANGER INCLUDING THE SAME

Abstract

A corrugated fin has flat plate sections each having a pair of lateral sides facing each other and a pair of end sides facing each other, and joining sections connecting with lateral sides of the flat plate sections. The flat plate sections and joining sections are alternately formed into a corrugated shape by bending. The joining section has an even surface joined to a tube through which a heat exchange medium flows, while the flat plate section includes a recess or protrusions in arbitrary sections taken along two directions including a direction in which the lateral sides are arranged and a direction in which the end sides are arranged, respectively.

Description

TECHNICAL FIELD

The present invention relates to a corrugated fin for dissipating heat of a heat exchange medium in a heat exchanger such as a radiator, an oil cooler or an after-cooler. The invention also relates to the heat exchanger including the corrugated fin.

BACKGROUND ART

In an engine room of a work vehicle such as a hydraulic excavator or a bulldozer, an engine, a radiator, a cooling fan and others are placed in a predetermined pattern of locations. When driven, the cooling fan causes a flow of cooling air which passes through the radiator, thereby cooling engine cooling water circulating between the engine and the radiator.

The radiator is constructed mainly of a top tank, a bottom tank, a plurality of tubes and fins.

The top tank and the bottom tank are coupled through the plurality of tubes arranged at predetermined intervals. Thus, the engine cooling water coining from the engine is once stored in the top tank, then passes through the plurality of tubes to be stored in the bottom tank, and is then returned to the engine.

The fins are each disposed between the adjacent tubes and joined to the tubes by joining means such as brazing.

As an example of the above-described fin, there is a corrugated fin having flat plate sections and joining sections that are alternately formed into a corrugated shape by bending (refer to, for example, patent documents 1, 2 and 3). The flat plate sections of such a corrugated fin each has a pair of lateral sides facing each other and a pair of end sides facing each other, while the joining sections each connect with the lateral sides of the flat plate sections.

RELATED ART DOCUMENTS

Patent Documents

Patent Document 1: Japanese Patent Unexamined Publication No. 2007-232246

Patent Document 2: Japanese Patent Unexamined Publication No. 2002-228379

Patent Document 3: Japanese Patent Unexamined Publication No. H09-155487

The corrugated fin is manufactured, for example, by undergoing a grooving process and a corrugating process.

The grooving process is a process of forming a plurality of grooves on a surface of a bandlike sheet by passing the bandlike sheet uncoiled from a sheet coil between a pair of grooving rollers or by press working using a press machine.

In the corrugating process, the bandlike sheet which has undergone the grooving process is passed through a pair of corrugating rollers for bending, whereby the flat plate sections and the joining sections form a corrugated shape in an alternating sequence.

Examples of the grooves formed in the bandlike sheet in the grooving process include grooves extending in a direction in which the pair of lateral sides of the flat plate section are arranged and grooves extending in a direction in which the pair of end sides of the flat plate section are arranged.

Providing the flat plate section with the grooves extending in the direction in which the pair of lateral sides are arranged can increase a section modulus of a section taken along the direction in which the pair of end sides are arranged. Accordingly the flat plate section can have increased rigidity with respect to such a bending action as to bring the pair of lateral sides close to each other. However, in this case, a section taken along the direction in which the pair of lateral sides are arranged cannot have an increased section modulus, so that the flat plate section cannot have increased rigidity with respect to such a bending action as to bring the pair of end sides close to each other.

Providing the flat plate section with the grooves extending in the direction in which the pair of end sides are arranged can increase a section modulus of a section taken along the direction in which the pair of lateral sides are arranged. Accordingly the flat plate section can have increased rigidity with respect to such the bending action as to bring the pair of end sides close to each other. However, in this case, a section taken along the direction in which the pair of end sides are arranged cannot have an increased section modulus, so that the flat plate section cannot have increased rigidity with respect to such the bending action as to bring the pair of lateral sides close to each other.

Therefore, during the production of the conventional corrugated fins or, more specifically, in the corrugating process, bending can possibly occur at an unexpected place, thereby problematically increasing a dimensional error.

For this reason, the dimensional errors of the corrugated fins accumulate when a radiator core is assembled by alternately stacking the corrugated fins and the tubes, which in turn may warp the radiator core, leaving a problem that product accuracy is difficult to improve. Correcting the dimensional error of the corrugated fin requires extra time and effort, while assembling such that the dimensional errors of the corrugated fins offset one another requires a high skill In any case, the production problematically becomes difficult.

SUMMARY OF THE INVENTION

Problems to be Solved by the Invention

In view of the problems mentioned above, the present invention aims to provide a corrugated fin capable of reliably preventing bending at an unexpected place during production, thereby improving product accuracy and facilitating the production. The invention also aims to provide a heat exchanger including this corrugated fin.

Means for Solving the Problems

To achieve the above object, a corrugated fin for a heat exchanger according to a first aspect of the present invention comprises a flat plate section and a joining section which are alternately formed into a corrugated shape by bending, said flat plate section having a pair of lateral sides facing each other and a pair of end sides facing each other, said joining section connecting with a lateral side of the pair of lateral sides of the flat plate section,

wherein said joining section has an even surface joined to a tube through which a heat exchange medium is circulated and

wherein said flat plate section has at least one recess or protrusion in an arbitrary section taken in two directions, the two directions being a direction in which the pair of lateral sides are arranged and a direction in which the pair of end sides are arranged.

According to a second aspect of the invention that is based on the first aspect, it is preferable that the even surface of the joining section is formed into a plane surface.

According to a third aspect of the invention that is based on the first aspect, it is preferable that the even surface of the joining section is formed into a curved surface.

According to a fourth aspect of the invention that is based on the first., second or third aspect, it is preferable that two or more recesses or protrusions are provided.

A heat exchanger according to a fifth aspect of the invention includes the corrugated fin of the first, second, third or fourth aspect.

Advantages of the Invention

In the corrugated fin of the first aspect of the invention, the flat plate section is provided with at least one recess or protrusion in the arbitrary section taken in the two directions, that is, the direction in which the pair of lateral sides are arranged and the direction in which the pair of end sides are arranged. Accordingly, the section taken along the direction in which the pair of end sides are arranged and the section taken along the direction in which the pair of lateral sides are arranged can have increased section moduli, respectively. For this reason, the flat plate section can have increased rigidity with respect to such a bending action as to bring the pair of lateral sides close to each other as well as with respect to such a bending action as to bring the pair of end sides close to each other.

The joining section is not provided with any recess or protrusion such as provided in the flat plate section. This allows a large difference in rigidity between the flat plate section and the joining section, thus enabling easy and reliable bending at a boundary between the flat plate section and the joining section.

In the corrugated fin of the first aspect of the invention, bending at an unexpected place can be prevented without fail during production of the corrugated fin, whereby the corrugated fin can have a reduced dimensional error.

Adopting the structure of the second aspect of the invention can increase an area joined to the tube and a thermal contact area, thus allowing stronger joining between the corrugated fin and the tube and enhancing a heat dissipation effect of the corrugated fin.

Adopting the structure of the third aspect of the invention can avoid stress concentration on a bent part.

Adopting the structure of the fourth aspect of the invention can further increase the rigidity of the flat plate section without fail and allows easier and more reliable bending at the boundary between the flat plate section and the joining section.

The heat exchanger of the fifth aspect of the invention has increased product accuracy and is thus easy to produce.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a general perspective view of a radiator in accordance with a first exemplary embodiment of the present invention.

FIG. 2 is an enlarged perspective view of part. X in FIG. 1.

FIG. 3(a) illustrates the structure of a flat plate section viewed from the direction of arrow Y in FIG. 2, and FIGS. 3(b), 3(c) and 3(d) are sectional views taken along respective lines A-A, B-B, B′-B′ in FIG. 3(a).

FIG. 4 is an enlarged view of an essential part viewed from the direction of arrow Z in FIG. 2.

FIG. 5(a) illustrates a method of manufacturing a corrugated fin, FIG. 5(b) is a state view before corrugation, FIG. 5(c) is a state view after the corrugation, and FIGS. 5(d) and 5(e) illustrate respective shapes of an even surface, with FIG. 5(d) illustrating a plane surface and FIG. 5(e) illustrating a curved surface.

FIG. 6 illustrates variations of the corrugated fin in accordance with the first embodiment.

FIG. 7(a) illustrates the structure of a flat plate section of a corrugated fin in accordance with a second exemplary embodiment, and FIGS. 7(b), 7(c) and 7(d) are sectional views taken along respective lines C-C, D-D, D′-D′ in FIG. 7(a).

FIG. 8(a) illustrates the structure of a flat plate section of a corrugated fin in accordance with a third exemplary embodiment, and FIGS. 8(b), 8(c) and 8(d) are sectional views taken along respective lines E-E, F-F, F′-F′ in FIG. 8(a).

FIG. 9(a) illustrates the structure of a flat plate section of a corrugated fin in accordance with a fourth exemplary embodiment, and FIGS. 9(b) and 9(c) are sectional views taken along respective lines G-G, H-H in FIG. 9(a).

FIG. 10(a) illustrates the structure of a flat plate section of a corrugated fin in accordance with a fifth exemplary embodiment, and FIGS. 10(b) and 10(c) are sectional views taken along respective lines H, J-J in FIG. 10(a).

FIG. 11(a) illustrates the structure of a flat plate section of a corrugated fin in accordance with a sixth exemplary embodiment, and FIGS. 11(b) and 11(c) are sectional views taken along respective lines K-K, L-L in FIG. 11(a).

FIG. 12(a) illustrates the structure of a flat plate section of a corrugated fin in accordance with a seventh exemplary embodiment, and FIGS. 12(b), 12(c), 12(d) and 12(e) are sectional views taken along respective lines M-M, M′-M′, N-N, N′-N′ in FIG. 12(a).

FIG. 13(a) illustrates the structure of a flat plate section of a corrugated fin in accordance with an eighth exemplary embodiment, and FIGS. 13(b) and 13(c) are sectional views taken along respective lines Q-Q, R-R in FIG. 13(a).

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Concrete exemplary embodiments of a corrugated fin and a heat exchanger including the corrugated fin according to the present invention are demonstrated hereinafter with reference to the accompanying drawings. The following description is provided of an example in which the invention is applied to a radiator installed in an engine room of a work vehicle such as a hydraulic excavator or a bulldozer. However, it goes without saying that the invention is applicable to heat exchangers having the same basic structure as the radiator, such as an oil cooler and an after-cooler.

First Exemplary Embodiment

FIG. 1 is a general perspective view of a radiator including a corrugated fin in accordance with the first, exemplary embodiment, of the invention.

(Description of a Schematic Structure of the Radiator)

Radiator 1 shown in FIG. 1 is a device for dissipating heat that engine cooling water (a heat exchange medium) circulating between radiator 1 and an engine (not shown) obtains from the engine.

This radiator 1 is constructed mainly of top tank 2, bottom tank 3, tubes 4 and corrugated fins 5.

Top tank 2 and bottom tank 3 are coupled through the plurality of tubes 4, thus allowing the engine cooling water coming from the engine to be once stored in top tank 2, then pass through the plurality of tubes 4 to be stored in bottom tank 3 and be returned to the engine thereafter.

Tubes 4 and corrugated fins 5 are alternately stacked to form radiator core 6.

(Description of the Tubes)

As shown in FIG. 2, tubes 4 are each formed of a flattened tube member having internal passage 4a for the engine cooling water.

The plurality of tubes 4 are arranged at predetermined pitch Pa along width direction RW of radiator 1 and at predetermined spacing S along depth direction RD of radiator 1.

(Brief Description of the Corrugated Fin)

Corrugated fin 5 is disposed between tubes 4 which are adjacent in width direction RW of radiator 1. Corrugated fin 5 has flat plate sections 5a and joining sections 5b that are alternately formed into a corrugated shape by bending.

(Brief Description of the Flat Plate Section)

Each flat plate section 5a is a rectangular plate section having a pair of lateral sides 11, 11′ facing each other in width direction RW of radiator 1 and a pair of end sides 12, 12′ facing each other in depth direction RD of radiator 1.

(Description of Groove-Shaped Recesses of the Flat Plate Section)

As shown in FIG. 3(a), flat plate section 5a is provided with, on its surface, the plurality of groove-shaped recesses 13 regularly spaced at predetermined pitch Pb along direction FD in which the pair of end sides 12, 12′ are arranged.

Groove-shaped recesses 13 extend linearly in a direction from end side 12 toward end side 12′ while slanting in a direction from lateral side 11 toward lateral side 11′.

Pitch Pb for arranging groove-shaped recesses 13, an angle of inclination, length and width of each groove-shaped recess 13 and others are determined so that adjacent groove-shaped recesses 13 partly overlap each other when viewed in direction FW in which the pair of lateral sides 11, 11′ are arranged. Providing the plurality of groove-shaped recesses 13 on the surface of flat plate section 5a causes a part between adjacent groove-shaped recesses 13 to become relatively stripe-shaped protrusion 14. In addition, providing groove-shaped recesses 13 on the surface of flat plate section 5a results in formation of corresponding stripe-shaped protrusions 15 (see FIGS. 3(b) and 3(c)) on a back surface of flat plate section 5a.

(Description of Recesses and Protrusions of the Flat Plate Section in Arbitrary Sections)

As shown in FIG. 3(b), flat plate section 5a has the plurality of recesses 16 defined by the respective plurality of groove-shaped recesses 13 in the arbitrary section taken along direction FD in which the pair of end sides 12, 12′ are arranged. In other words, flat plate section 5a has the plurality of protrusions 17, 18 defined by the respective plurality of stripe-shaped protrusions 14, 15 in the arbitrary section taken along direction FD in which end sides 12, 12′ are arranged.

As shown in FIGS. 3(c) and 3(d), flat plate section 5a has recesses 16 defined by respective groove-shaped recesses 13 in the arbitrary sections taken along direction FW in which the pair of lateral sides 11, 11′ are arranged. In other words, flat plate section 5a has protrusions 17, 18 defined by respective stripe-shaped protrusions 14, 15 in the arbitrary sections taken along direction FW in which lateral sides 11, 11′ are arranged. It is to be noted that there exists, as shown in FIG. 3(c), one recess 16 defined by groove-shaped recess 13 or one protrusion 18 defined by stripe-shaped protrusion 15 in the section of flat plate section 5a that is taken along line B-B, while there exists, as shown in FIG. 3(d), two recesses 16 defined by respective groove-shaped recesses 13 or two protrusions 18 defined by respective stripe-shaped protrusions 15 in the section taken along line B′-B′.

(Brief Description of the Joining Section)

As shown in FIG. 4, joining section 5b is a rectangular plate section which makes a right angle with flat plate section 5a, is narrower than flat plate section 5a and has even surface 20 joined to tube 4. Even surface 20 is a plane surface parallel to surface 21 of tube 4.

Conceptually, this even surface 20 has two implications, one of which is that surface 20 is a completely even surface free of undulation and the other of which is that surface 20 is a substantially even surface having, compared with groove-shaped recesses 13, extremely negligible shallow grooves (grooved remnants) which are formed inevitably when a grooving process is carried out to form groove-shaped recesses 13 in flat plate section 5a.

(Description of Joining between the Corrugated Fin and the Tube)

Corrugated fin 5 and tube 4 are joined together by brazing using brazing filler metal 22 interposed between even surface 20 of joining section 5b and surface 21 of tube 4.

Because of being plane, even surface 20 of joining section 5b can have a larger area joined to tube 4 and a larger thermal contact area compared to cases where even surface 20 is a curved surface or an angular surface.

Obtaining the larger joining area between even surface 20 of joining section 5b and surface 21 of tube 4 enables stronger joining between corrugated fin 5 and tube 4.

Obtaining the larger thermal contact area between even surface 20 of joining section 5b and surface 21 of tube 4 enables efficient conduction of the heat of the engine cooling water, which flows through tube 4, from tube 4 to corrugated fin 5, thereby enhancing a heat dissipation effect of corrugated fin 5.

(Description of a Method of Manufacturing the Corrugated Fin)

A description is provided next of the method of manufacturing corrugated fin 5 with reference to FIG. 5(a).

The manufacturing method of corrugated fin 5 includes the grooving process and a corrugating process.

(Description of the Grooving Process)

The grooving process is a process of forming the plurality of groove-shaped recesses 13 on a surface of bandlike sheet 30a, a corrugated fin material, by passing bandlike sheet 30a uncoiled from sheet coil 30 between a pair of first rollers 31, 31′.

The pair of first rollers 31, 31′ have a plurality of recesses and protrusions (not shown) on their outer peripheral surfaces to correspond to the plurality of groove-shaped recesses 13 to he formed in bandlike sheet 30a. As first rollers 31, 31′ are rotated in respective directions of arrows in the drawing, bandlike sheet 30a is sandwiched between these rollers 31, 31′ and then sent downstream. Here, the plurality of groove-shaped recesses 13 are formed on the surface of bandlike sheet 30a as a result of bandlike sheet 30a being sandwiched between the recesses of first roller 31 on one side and the protrusions of first roller 31′ on the other side.

It is to be noted that similar groove-shaped recesses 13 can be formed on the surface of bandlike sheet 30a by press working using a press machine.

(Description of the Corrugating Process)

The corrugating process is a bending process in which bandlike sheet 30a coming out from between the pair of first rollers 31, 31′ is passed through a pair of second rollers 32, 32′ disposed downstream of first rollers 31, 31′, whereby flat plate sections 5a and joining sections 5b form the corrugated shape in an alternating sequence.

The pair of second rollers 32, 32′ have a plurality of teeth (not shown) on their outer peripheral surfaces for bending bandlike sheet 30a, which has groove-shaped recesses 13 formed on its surface, into the corrugated shape. The teeth of roller 32 and the teeth of roller 32′ are formed to mesh together. As second rollers 32, 32′ are rotated in respective directions of arrows in the drawing, bandlike sheet 30a is sandwiched between these rollers 32, 32′ and then sent downstream. Here, bandlike sheet 30a is bent into the corrugated shape as a result of being sandwiched between a space between the teeth of second roller 32 and the tooth of second roller 32′.

As shown in FIG. 5(b), bandlike sheet 30a which will undergo the corrugation has sections (indicated by arrows T in the drawing) free of groove-shaped recesses 13 and stripe-shaped protrusions 14 resulting from groove-shaped recesses 13. The corrugation is carried out so that these sections become joining sections 5b each having even surface 20 (see FIG. 5(c)).

In this embodiment, even surface 20 is plane as shown in FIG. 5(d). However, even surface 20 is not limited to this and may also be curved as shown in FIG. 5(e). Forming even surface 20 into the curved surface can avoid stress concentration on a bent part.

Corrugated fin 5 which has undergone the corrugating process is thus sandwiched between adjacent tubes 4 and joined to those tubes 4 by brazing.

Description of Effects of the First Embodiment

In corrugated fin 5 of the first embodiment, flat plate section 5a is provided with, as shown in FIGS. 3(b) and 3(c), recesses 16 defined by groove-shaped recesses 13 or protrusions 17, 18 defined by stripe-shaped protrusions 14, 15 in the arbitrary sections taken along the respective two directions, that is, direction FW in which the pair of lateral sides 11, 11′ are arranged and direction FD in which the pair of end sides 12, 12′ are arranged. This can increase a section modulus of the section taken along direction FD in which end sides 12, 12′ are arranged as well as a section modulus of the section taken along direction FW in which lateral sides 11, 11′ are arranged. For this reason, flat plate section 5a can have increased rigidity with respect to such a bending action as to bring lateral sides 11, 11′ close to each other as well as with respect to such a bending action as to bring end sides 12, 12′ close to each other.

Joining section 5b is not provided with recess 16 defined by groove-shaped recess 13 or protrusions 17, 18 defined by respective stripe-shaped protrusions 14, 15 such as provided at flat plate section 5a. This allows a large difference in rigidity between flat plate section 5a and joining section 5b, thus enabling easy and reliable bending at a boundary between flat plate section 5a and joining section 5b.

Consequently, bending at an unexpected place can be prevented without fail during the production of corrugated fin 5 or, more specifically, in the corrugating process, thus reducing a dimensional error of corrugated fin 5.

Radiator core 6 of radiator 1 of the first embodiment is assembled by alternately stacking tubes 4 and corrugated fins 5. Because the dimensional error of each corrugated fin 5 can be reduced, radiator core 6 does not warp, thereby increasing product accuracy. Moreover, no correction of the dimensional error of corrugated fin 5 and no high skill for offsetting the dimensional errors against one another are required, thus facilitating the production.

Description of Variations of the First Embodiment

FIGS. 6(a) to 6(f) are plan views of respective flat plate sections 5a, illustrating the variations of corrugated fin 5 of the first embodiment.

Corrugated fin 5 of the first embodiment has, at its flat plate section 5a, at least one recess 16 defined by groove-shaped recess 13 in the arbitrary section taken along each of the two directions, that is, direction FW in which the pair of lateral sides 11, 11′ are arranged and direction FD in which the pair of end sides 12, 12 are arranged. Appropriate variations can be made on this structure without: departing from the spirit of this structure.

For example, groove-shaped recess 13 can be replaced by groove-shaped recess 13A having a greater groove width than recess 13 as shown in FIG. 6(a).

As shown in FIG. 6(b), pitch Pb at which groove-shaped recesses 13 are arranged can be changed to smaller pitch Pc.

As shown in FIG. 6(c), groove-shaped recesses 13 can be arranged at least two different pitches Pd, Pe.

As shown in FIG. 6(d), groove-shaped recesses 13, 13A of different groove widths can be alternately arranged.

As shown in FIG. 6(e), a plurality of groove-shaped recesses 13B shorter in length than groove-shaped recesses 13 are arranged alternately as equivalents of recesses 13.

While groove-shaped recesses 13 extend linearly in the direction from end side 12 of flat plate section 5a toward end side 12′, slanting in the direction from lateral side 11 toward lateral side 11′, groove-shaped recesses 13C shown in FIG. 6(f) can be adopted instead. These recesses 13C extend linearly in the direction from end side 12 of flat plate section 5a toward end side 12′ while slanting in an opposite direction, that is, from lateral side 11′ toward lateral side 11.

Second Through Eighth Exemplary Embodiments

Hereinafter, descriptions of corrugated fins 5A to 5G in accordance with the respective second through eighth exemplary embodiments of the present invention are provided one by one. In the following embodiments, elements similar to those in the first embodiment have the same reference marks in drawings, the detailed descriptions of those elements are omitted, and emphasis is placed on different features not seen in the first embodiment.

Description of Groove-Shaped Recesses of a Flat Plate Section Shown in FIG. 7(a) in Accordance with the Second Embodiment

As shown in FIG. 7(a), corrugated fin 5.A of the second embodiment has, on a surface of its flat plate section 5a, the plurality of groove-shaped recesses 40 regularly spaced at predetermined pitch Pf along direction FD in which a pair of end sides 12, 12′ are arranged.

Each groove-shaped recess 40 is formed of first groove-shaped recess 40a and second groove-shaped recess 40b, and in the plan view with end side 12′ of flat plate section 5a being above the other end side 12, first and second groove-shaped recesses 40a, 40b connect in a V shape.

Starting from a middle point of direction FW in which a pair of lateral sides 11, 11′ of flat plate section 5a are arranged, first groove-shaped recess 40a extends linearly in a direction from end side 12 toward end side 12′ while slanting in a direction from lateral side 11 toward lateral side 11′.

Starting from the middle point of direction FW in which lateral sides 11, 11′ of flat plate section 5a are arranged, second groove-shaped recess 40b extends linearly in the direction from end side 12 toward end side 12′ while slanting in a direction from lateral side 11′ toward lateral side 11.

Description of Recesses and Protrusions of the Flat Plate Section in Arbitrary Sections Shown in FIGS. 7(b), 7(c) and 7(d) in Accordance With the Second Embodiment

As shown in FIG. 7(b), flat plate section 5a has the plurality of recesses 41 defined by the respective plurality of groove-shaped recesses 40 in the arbitrary section taken along direction FD in which the pair of end sides 12, 12′ are arranged. In other words, flat plate section 5a has the plurality of protrusions 44, 45 defined by a respective plurality of stripe-shaped protrusions 42, 43 in the arbitrary section taken along direction FD in which end sides 12, 12′ are arranged.

As shown in FIGS. 7(c) and 7(d), flat plate section 5a has recesses 41 defined by groove-shaped recesses 40 in the arbitrary sections taken along direction FW in which the pair of lateral sides 11, 11′ are arranged. In other words, flat plate section 5a has protrusions 44, 45 defined by stripe-shaped protrusions 42, 43 in the arbitrary sections taken along direction FW in which lateral sides 11, 11′ are arranged. It is to be noted that there exists, as shown in FIG. 7(c), one recess 41 defined by groove-shaped recess 40 or one protrusion 45 defined by stripe-shaped protrusion 43 in the section of flat plate section 5a that is taken along line D-D, while there exists, as shown in FIG. 7(d), two recesses 41 defined by groove-shaped recess 40 or two protrusions 45 defined by stripe-shaped protrusion 43 in the section taken along line D′-D′.

Description of Groove-Shaped Recesses of a Flat Plate Section Shown in FIG. 8(a) in Accordance With the Third Embodiment

As shown in FIG. 8(a), corrugated fin 5B of the third embodiment has, on a surface of its flat plate section 5a, the plurality of groove-shaped recesses 46 regularly spaced at predetermined pitch Pg along direction FD in which a pair of end sides 12, 12′ are arranged.

Groove-shaped recesses 46 are recesses each bent into an arc shape, bulging toward end side 12 between lateral sides 11, 11′.

Description of Recesses and Protrusions of the Flat Plate Section in Arbitrary Sections Shown in FIGS. 8(b), 8(c) and 8(d) in Accordance With the Third Embodiment

As shown in FIG. 8(b), flat plate section 5a has the plurality of recesses 47 defined by the respective plurality of groove-shaped recesses 46 in the arbitrary section taken along direction FD in which the pair of end sides 12, 12′ are arranged. In other words, flat plate section 5a has the plurality of protrusions 50, 51 defined by a respective plurality of stripe-shaped protrusions 48, 49 in the arbitrary section taken along direction FD in which end sides 12, 12′ are arranged.

As shown in FIGS. 8(c) and 8(d), flat plate section 5a has recesses 47 defined by groove-shaped recesses 46 in the arbitrary sections taken along direction FW in which the pair of lateral sides 11, 11′ are arranged. In other words, flat plate section 5a has protrusions 50, 51 defined by stripe-shaped protrusions 48, 49 in the arbitrary sections taken along direction FW in which lateral sides 11, 11′ are arranged. It is to be noted that there exists, as shown in FIG. 8(c), one recess 47 defined by groove-shaped recess 46 or one protrusion 51 defined by stripe-shaped protrusion 49 in the section of flat plate section 5a that is taken along line F-F, while there exists, as shown in FIG. 8(d), two recesses 47 defined by groove-shaped recess 46 or two protrusions 51 defined by stripe-shaped protrusion 49 in the section taken along line F′-F′.

Description of Groove-Shaped Recesses of a Flat Plate Section Shown in FIG. 9(a) in Accordance With the Fourth Embodiment

As shown in FIG. 9(a), corrugated fin 5C of the fourth embodiment has, on a surface of its flat plate section 5a, the plurality of groove-shaped recesses 52 regularly spaced at predetermined pitch Ph along direction FD in which a pair of end sides 12, 12′ are arranged.

Each groove-shaped recess 52 is formed of first groove-shaped recess 52a, second groove-shaped recess 52b, third groove-shaped recess 52c and fourth groove-shaped recess 52d, and in the plan view with end side 12′ of flat plate section 5a being above the other end side 12, those first through fourth groove-shaped recesses 52a, 52b, 52c, 52d connect in a W shape.

Starting from a point located in the middle between lateral side 11′ and a middle point of direction FW in which lateral sides 11, 11′ of flat plate section 5a are arranged, first groove-shaped recess 52a extends linearly in a direction from end side 12 toward end side 12′ while slanting in a direction from lateral side 11 toward lateral side 11′.

Starting from the point located in the middle between lateral side 11′ and the middle point of direction FW in which lateral sides 11, of flat plate section 5a are arranged, second groove-shaped recess 52b extends linearly in the direction from end side 12 toward end side 12′ while slanting in a direction from lateral side 11′ toward lateral side 11.

Starting from a point located in the middle between lateral side 11 and the middle point of direction FW in which lateral sides 11, 11′ of flat plate section 5a are arranged, third groove-shaped recess 52c extends linearly in the direction from end side 12 toward end side 12′ while slanting in the direction from lateral side 11 toward lateral side 11′.

Starting from the point located in the middle between lateral side 11 and the middle point of direction FW in which lateral sides 11, 11′ of flat plate section 5a are arranged, fourth groove-shaped recess 52d extends linearly in the direction from end side 12 toward end side 12′ while slanting in the direction from lateral side 11′ toward lateral side 11.

Description of Recesses and Protrusions of the Flat Plate Section in Arbitrary Sections Shown in FIGS. 9(b) and 9(c) in Accordance With the Fourth Embodiment

As shown in FIG. 9(b), flat plate section 5a has the plurality of recesses 53 defined by the respective plurality of groove-shaped recesses 52 in the arbitrary section taken along direction FD in which the pair of end sides 12, 12′ are arranged. In other words, flat plate section 5a has the plurality of protrusions 56, 57 defined by a respective plurality of stripe-shaped protrusions 54, 55 in the arbitrary section taken along direction FD in which end sides 12, 12′ are arranged.

As shown in FIG. 9(c), flat plate section 5a has at least two recesses 53 defined by groove-shaped recess 52 in the arbitrary section taken along direction FW in which the pair of lateral sides 11, 11′ are arranged. In other words, flat plate section 5a has at least two protrusions 56, 57 defined by stripe-shaped protrusion 54, 55 in the arbitrary section taken along direction FW in which lateral sides 11, 11′ are arranged.

Description of Groove-Shaped Recesses of a Flat Plate Section Shown in FIG. 10(a) in Accordance With the Fifth Embodiment

As shown in FIG. 10(a), corrugated fin 5D of the fifth embodiment has, on a surface of its flat plate section 5a, the plurality of groove-shaped recesses 58 regularly spaced at predetermined pitch Pi along direction FW in which a pair of lateral sides 11, 11′ are arranged.

Each groove-shaped recess 58 is formed of first groove-shaped recess 58a, second groove-shaped recess 58b, third groove-shaped recess 58c and fourth groove-shaped recess 58d, and in the plan view with lateral side 11′ of flat plate section 5a being above the other lateral side 11, those first through fourth groove-shaped recesses 58a, 58b, 58c, 58d connect in an M shape.

Starting from a point located in the middle between end side 12 and a middle point of direction FD in which a pair of end sides 12, 12′ of flat plate section 5a are arranged, first groove-shaped recess 58a extends linearly in a direction from end side 12′ toward end side 12 while slanting in a direction from lateral side 11′ toward lateral side 11.

Starting from the point located in the middle between end side 12 and the middle point of direction FD in which end sides 12, 12′ of flat plate section 5a are arranged, second groove-shaped recess 58b extends linearly in a direction from end side 12 toward end side 12′ while slanting in the direction from lateral side 11′ toward lateral side 11.

Starting from a point located in the middle between end side 12′ and the middle point of direction FD in which lateral sides 12, 12′ of flat plate section 5a are arranged, third groove-shaped recess 58c extends linearly in the direction from end side 12′ toward end side 12 while slanting in the direction from lateral side 11′ toward lateral side 11.

Starting from the point located in the middle between end side 12′ and the middle point of direction FD in which lateral sides 12, 12′ of flat plate section 5a are arranged, fourth groove-shaped recess 58d extends linearly in the direction from end side 12 toward end side 12′ while slanting in the direction from lateral side 11′ toward lateral side 11.

Description of Recesses and Protrusions of the Flat Plate Section in Arbitrary Sections Shown in FIGS. 10(b) and 10(c) in Accordance With the Fifth Embodiment

As shown in FIG. 10(b), flat plate section 5a has at least two recesses 59 defined by groove-shaped recesses 58 in the arbitrary section taken along direction FD in which the pair of end sides 12, 12′ are arranged. In other words, flat plate section 5a has at least two protrusions 62, 63 defined by stripe-shaped protrusions 60, 61 in the arbitrary section taken along direction FD in which end sides 12, 12′ are arranged.

As shown in FIG. 10(c), flat plate section 5a has the plurality of recesses 59 defined by the respective plurality of groove-shaped recesses 58 in the arbitrary section taken along direction FW in which the pair of lateral sides 11, 11′ are arranged. In other words, flat plate section 5a has the plurality of protrusions 62, 63 defined by the respective plurality of stripe-shaped protrusions 60, 61 in the arbitrary section taken along direction FW in which lateral sides 11, 11′ are arranged.

Description of Groove-Shaped Recesses of a Flat Plate Section Shown in FIG. 11(a) in Accordance With the Sixth Embodiment

As shown in FIG. 11(a), corrugated fin 5E of the sixth embodiment has, on a surface of its flat plate section 5a, the plurality of first groove-shaped recesses 64 and the plurality of second groove-shaped recesses 65 that are regularly spaced at predetermined pitch Pj along direction FD in which a pair of end sides 12, 12′ are arranged.

Each first groove-shaped recess 64 extends linearly in a direction from end side 12 toward end side 12′ while slanting in a direction from lateral side 11 toward lateral side 11′.

Each second groove-shaped recess 65 extends linearly in the direction from end side 12 toward end side 12′ while slanting in a direction from lateral side 11′ toward lateral side 11.

First groove-shaped recesses 64 cross second groove-shaped recesses 65, thus forming a mesh-like pattern as a whole.

Description of Recesses and Protrusions of the Flat Plate Section in Arbitrary Sections Shown in FIGS. 11(b) and 11(c) in Accordance With the Sixth Embodiment

As shown in FIG. 11(b), flat plate section 5a has the plurality of recesses 66 defined by the plurality of groove-shaped recesses 64, 65 in the arbitrary section taken along direction FD in which the pair of end sides 12, 12′ are arranged. In other words, flat plate section 5a has the plurality of protrusions 69, 70 defined by a plurality of stripe-shaped protrusions 67, 68 in the arbitrary section taken along direction FD in which end sides 12, 12′ are arranged.

As shown in FIG. 11(c), flat plate section 5a has the plurality of recesses 66 defined by the plurality of groove-shaped recesses 64, 65 in the arbitrary section taken along direction FW in which the pair of lateral sides 11, 11′ are arranged. In other words, flat plate section 5a has the plurality of protrusions 69, 70 defined by the plurality of striped-shaped protrusions 67, 68 in the arbitrary section taken along direction FW in which lateral sides 11, 11′ are arranged.

Description of Groove-Shaped Recesses of a Flat Plate Section Shown in FIG. 12(a) in Accordance With the Seventh Embodiment

As shown in FIG. 12(a), corrugated fin 5F of the seventh embodiment has first groove-shaped recess 71 and second groove-shaped recess 72 on a surface of its flat plate section 5a.

First groove-shaped recess 71 extends linearly between a corner where lateral side 11 and end side 12 meet and a corner where lateral side 11′ and end side 12′ meet.

Second groove-shaped recess 72 extends linearly between a corner where lateral side 11′ and end side 12 meet and a corner where lateral side 11 and end side 12′ meet.

First groove-shaped recess 71 and second groove-shaped recess 72 cross each other, thus forming an X shape.

Description of Recesses and Protrusions of the Flat Plate Section in Arbitrary Sections Shown in FIGS. 12(b), 12(c), 12(d) and 12(e) in Accordance With the Seventh Embodiment

As shown in FIGS. 12(b) and 12(c), flat plate section 5a has recesses 73, 74 defined by groove-shaped recesses 71, 72 in the arbitrary sections taken along direction FD in which the pair of end sides 12, 12′ are arranged. In other words, flat plate section 5a has protrusions 77, 78 defined by stripe-shaped protrusions 75, 76 in the arbitrary sections taken along direction FD in which end sides 12, 12′ are arranged. It is to be noted that there exists, as shown in FIG. 12(b), one recess 73 (74) defined by groove-shaped recess 71 (72) or one protrusion 77 (78) defined by stripe-shaped protrusion 75 (76) in the section of flat plate section 5a that is taken along line M-M, while there exists, as shown in FIG. 12(c), two recesses 73 (74) defined by respective groove-shaped recesses 71 (72) or two protrusions 77 (78) defined by respective stripe-shaped protrusions 75 (76) in the section taken along line M′-M′.

As shown in FIGS. 12(d) and 12(e), flat plate section 5a has recesses defined by groove-shaped recesses 71, 72 in the arbitrary sections taken along direction FW in which the pair of lateral sides 11, 11′ are arranged. In other words, flat plate section has protrusions 77, 78 defined by stripe-shaped protrusions 75, 76 in the arbitrary sections taken along direction FW in which lateral sides 11, 11′ are arranged. It is to be noted that there exists, as shown in FIG. 12(d), one recess 73 (74) defined by groove-shaped recess 71 (72) or one protrusion 77 (78) defined by stripe-shaped protrusion 75 (76) in the section of flat plate section 5a that is taken along line N-N, while there exists, as shown in FIG. 12(e), two recesses 73 (74) defined by respective groove-shaped recesses 71 (72) or two protrusions 77 (78) defined by respective stripe-shaped protrusions 75 (76) in the section taken along line N′-N′.

Description of Groove-Shaped Recesses of a Flat Plate Section Shown in FIG. 13(a) in Accordance With the Eighth Embodiment

As shown in FIG. 13(a), corrugated fin 5G of the eighth embodiment has, on a surface of its flat plate section 5a, the plurality of hemispheric recesses 79 in a staggered arrangement in direction FW in which a pair of lateral sides 11, 11′ are arranged as well as in direction FD in which a pair of end sides 12, 12′ are arranged.

Pitch Pk for arranging hemispheric recesses 79, a diameter of each hemispheric recess 79 and others are determined so that hemispheric recesses 79 adjacent in direction FD in which end sides 12, 12′ are arranged partly overlap each other when viewed in direction FW in which lateral sides 11, 11′ are arranged.

Pitch Pm for arranging hemispheric recesses 79, the diameter of each hemispheric recess 79 and others are determined so that hemispheric recesses 79 adjacent in direction FW in which lateral sides 11, 11′ are arranged partly overlap each other when viewed in direction FD in which end sides 12, 12′ are arranged.

Description of Recesses and Protrusions of the Flat Plate Section in Arbitrary Sections Shown in FIGS. 13(b) and 13(c) in Accordance With the Eighth Embodiment

As shown in FIG. 13(b), flat plate section 5a has the plurality of recesses 80 defined by the respective plurality of hemispheric recesses 79 in the arbitrary section taken along direction FD in which the pair of end sides 12, 12′ are arranged. In other words, flat plate section 5a has the plurality of protrusions 82 defined by a respective plurality of hemispheric protrusions 81 in the arbitrary section taken along direction FD in which end sides 12, 12′ are arranged.

As shown in FIG. 13(c), flat plate section 5a has the plurality of recesses 80 defined by the respective plurality of hemispheric recesses 79 in the arbitrary section taken along direction FW in which the pair of lateral sides 11, 11′ are arranged. In other words, flat plate section 5a has the plurality of protrusions 82 defined by the respective plurality of hemispheric protrusions 81 in the arbitrary section taken along direction FW in which lateral sides 11, 11′ are arranged.

Description of Effects of the Second through Eighth Embodiments

Even in each of corrugated fins 5A, 5B, 5C, 5D, 5E, 5F, 5G of the second through eighth embodiments, flat plate section 5a is provided with at least one recess 41, 47, 53, 59, 66, 73 or 74 defined by groove-shaped recess 40, 46, 52, 58, 64, 65, 71 or 72 or at least one protrusion 44, 45, 50, 51, 56, 57, 62, 63, 69, 70, 77 or 78 defined by stripe-shaped protrusion 42, 43, 48, 49, 54, 55, 60, 61, 67, 68, 75 or 76, or at least one recess 80 defined by hemispheric recess 79 or at least one protrusion 82 defined by hemispheric protrusion 81 in the arbitrary section taken along each of the two directions, that is, direction FW in which the pair of lateral sides 11, 11′ are arranged and direction FD in which the pair of end sides 12, 12′ are arranged. This can increase a section modulus of the section taken along direction FD in which end sides 12, 12′ are arranged as well as a section modulus of the section taken along direction FW in which lateral sides 11, 11′ are arranged. Therefore, corrugated fins 5A to 5G of the second through eighth embodiments can provide the same effects as corrugated fin 5 of the first embodiment. Similarly to radiator 1 of the first embodiment, radiators including such respective corrugated fins 5A to 5G have increased product accuracy, thus facilitating their production.

The embodiments and variations of the corrugated fin and the heat exchanger including the corrugated fin according to the present invention have been described above. However, the present invention is not limited to the structures described in the above embodiments and variations and allows appropriate variations on each of the structures without departing from the spirit of the invention, such as, appropriately combining the structures of the above-described embodiments and variations.

INDUSTRIAL APPLICABILITY

A corrugated fin and a heat exchanger including the corrugated fin according to the present invention have the characteristic of being capable of reliably preventing bending at an unexpected place during production, thereby improving product accuracy and facilitating the production, and therefore, are suitable for use in and as a radiator, an oil cooler, an after-cooler or the like.

DESCRIPTION OF REFERENCE MARKS IN THE DRAWINGS

1 radiator (heat exchanger)

4 tube

5, 5A, 5B, 5C, 5D, 5E, 5F, 5G corrugated fins

5a flat plate section

5b joining section

11, 11′ lateral sides

12, 12′ end sides groove-shaped recess (first embodiment)

13A groove-shaped recess (variation of first embodiment)

13B groove-shaped recess (variation of first embodiment) groove-shaped protrusion (first embodiment)

16 recess (first embodiment)

17, 18 protrusions (first embodiment)

20 even surface

40 groove-shaped recess (second embodiment)

41 recess (second embodiment)

42, 43 stripe-shaped protrusions (second embodiment)

44, 45 protrusions (second embodiment)

46 groove-shaped recess (third embodiment)

47 recess (third embodiment)

49, 48 stripe-shaped protrusions (third embodiment)

50, 51 protrusions (third embodiment)

52 groove-shaped recess (fourth embodiment)

53 recess (fourth embodiment)

54, 55 stripe-shaped protrusions (fourth embodiment)

56, 57 protrusions (fourth embodiment)

58 groove-shaped recess (fifth embodiment)

59 recess (fifth embodiment)

60, 61 stripe-shaped protrusions (fifth embodiment)

62, 63 protrusions (fifth embodiment)

64, 65 groove-shaped recesses (sixth embodiment)

66 recess (sixth embodiment)

67, 68 stripe-shaped protrusions (sixth embodiment)

69, 70 protrusions (sixth embodiment)

71, 72 stripe-shaped recesses (seventh embodiment)

73, 74 recesses (seventh embodiment)

75, 76 stripe-shaped protrusions (seventh embodiment)

77, 78 protrusions (seventh embodiment)

79 hemispheric recess (eighth embodiment)

80 recess (eighth embodiment)

81 hemispheric protrusion (eighth embodiment)

82 protrusion (eighth embodiment)

Claims

1. A corrugated fin for a heat exchanger, comprising:

a flat plate section and a joining section which are alternately formed into a corrugated shape by bending, said flat plate section having a pair of lateral sides facing each other and a pair of end sides facing each other, said joining section connecting with a lateral side of the pair of lateral sides of the flat plate section,

wherein said joining section has an even surface joined to a tube through which a heat exchange medium is circulated, and

wherein said flat plate section has at least one recess or protrusion in an arbitrary section taken in two directions, one of the two directions being a direction in which the pair of lateral sides are arranged, and the other of the two directions being a direction in which the pair of end sides are arranged.

2. The corrugated fin of claim 1, wherein the even surface of the joining section is formed into a plane surface.

3. The corrugated fin of claim 1, wherein the even surface of the joining section is formed into a curved surface.

4. The corrugated fin of claim 1, wherein two or more recesses or protrusions are provided.

5. A heat exchanger including the corrugated fin of claim 1.

6. The corrugated fin of claim 2, wherein two or more recesses or protrusions are provided.

7. The corrugated fin of claim 3, wherein two or more recesses or protrusions are provided.

8. A heat exchanger including the corrugated fin of claim 2.

9. A heat exchanger including the corrugated fin of claim 3.

10. A heat exchanger including the corrugated fin of claim 4.

11. A heat exchanger including the corrugated fin of claim 6.

12. A heat exchanger including the corrugated fin of claim. 7.