Heat exchanger having laminated tubes

A heat exchanger has a pair of heat exchanging parts composed of laminated tubes. Each tube is composed of a pair of metal sheets joined to each other. Locating parts each having a projecting piece and a recess are arranged on respective sides of the metal sheet. When the metal sheets are mated, the projecting pieces are engaged with the recesses, respectively. Moreover, the metal sheets are in inverse relation to each other about a top-and-back inversion axis and the projecting pieces are arranged symmetrically to the recesses about the top-and-back inversion axis.

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Description
BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a heat exchanger having laminated tubes which are composed of a pair of metal sheets joined to each other, respectively.

2. Description of the Related Art

Japanese Patent Application Laid-open No. 2000-105091 discloses a heat exchanger having laminated tubes which are composed of a pair of metal sheets joined to each other.

In recent years, there has been requirement of miniaturization for heat exchangers for vehicles. With the requirements, it has been further required to make a heat exchanger thin in the draft direction. Thus, in the conventional heat exchanger, there was an attempt to narrow weld formed on the peripheral margins of the metal sheets in pairs.

However, the narrowing of such weld causes the possibility of increasing defects in welding the metal sheets in pairs in the production of a heat exchanger. Also noted that even if a heat exchanger has only one welding defect in one metal sheet, then the whole heat exchanger is regarded as a defective product, thereby incurring waste. In order to produce no detects in the production of heat exchangers, it is necessary to improve the management of assembling accuracy in the metal sheets in pairs, causing the manufacturing cost to be elevated.

SUMMARY OF THE INVENTION

In the above-mentioned situation, it is an object of the present invention to provide a heat exchanger having a plurality of tubes each of which has a pair of metal sheets and which is formed by reversing one metal sheet to overlap on the other metal sheet and further welding the metal sheets to each other, the heat exchanger being capable of narrowing the weld of the metal sheets with an improvement of the assembling accuracy of the metal sheets while suppressing a rise in the manufacturing cost as possible.

In order to attain the above object, the first aspect of the invention provides a heat exchanger, comprising: a heat exchanging part including laminated tubes each of which has a pair of metal sheets joined to each other, each of the tubes having heat exchanging passage formed therein to extend along the longitudinal direction of the tube, and cylindrical tank parts formed at both ends of each heat exchanging passage to project from a main body of the tube, the cylindrical tank parts of the adjoining tubes connected with each other in communication with each other, wherein the metal sheets have at least one top-and-back inversion axis about which one metal sheet is in inverse relation to the other metal sheet, and wherein each metal sheet has a plurality of projecting pieces formed on the outer circumferential edge of the metal sheet so as to project toward a mate to the metal sheet and a plurality of recesses formed on the outer circumferential edge of the metal sheet so as to allow the projecting pieces to be inserted thereinto respectively, the projecting pieces being respectively arranged symmetrically to the recesses about the top-and-back inversion axis, thereby the projecting piece and the recess constituting a locating part when the metal sheets are mated, the locating parts are provided on at least respective sides of the metal sheet, respectively.

In the heat exchanger of the first aspect, since the locating parts where the projecting pieces engage in the recesses when the metal sheets in pairs are laid to overlap on each other are provided on the respective sides of the outer circumferential edges of the metal sheets, it is possible to improve the assembling accuracy of the metal sheets and also possible to make the weld small thereby realizing a thin heat exchanger. Moreover, since the metal sheets have at least one top-and-back inversion axis about which one metal sheet is in inverse relation to the other metal sheet, and the projecting pieces being respectively arranged symmetrically to the recesses about the top-and-back inversion axis, it is possible to form the pair of metal sheets having an identical configuration. Thus, in spite of the provision of the projecting pieces and the recesses in view of the improvement in assembling accuracy, it is unnecessary to prepare metal sheets of different configurations, whereby the rise in manufacturing cost can be avoided.

In a preferred embodiment, the top-and-back inversion axis comprises a center line of the metal sheet in a longitudinal direction of the metal sheet. Further, the top-and-back inversion axis comprises a center line of the metal sheet in a direction perpendicular to a longitudinal direction of the metal sheet.

With the arrangement, when one metal is reversed about the center line of the metal sheet in a longitudinal direction or a direction perpendicular to the longitudinal direction of the metal sheet, the metal sheet can be mated to the other metal sheet accurately. Therefore this heat exchanger is superior in terms of its versatility. The laminated tubes constitute a pair of heat exchanging parts which are arranged side by side.

The heat exchanger comprises an inner fin which is disposed in the heat exchanging passage formed in the tube, wherein the projecting piece in at least one of the locating parts has a dimension in which a leading end thereof can pass through the recess at mating.

In this configuration, it is possible to fix one pair of metal sheets with each other preliminarily by crimping the projecting piece. Therefore, even if an inner fin is disposed in the metal sheets in such a preliminarily fixed state, it is possible to prevent an occurrence of displacement of the inner fin in the tube.

The projecting pieces in the locating parts allocated on at least opposing sides of the metal sheets have a dimension in which respective leading end thereof can pass through the recess at mating.

Also in this configuration, it is possible to fix one pair of metal sheets with each other preliminarily by crimping the projecting piece at the locating parts on the opposing sides of the metal sheets. Therefore, it is possible to prevent the occurrence of displacement of the inner fin more certainly.

The metal sheet has a substantially rectangular shape in plan view, and the projecting pieces in the locating parts allocated on both long sides of the rectangular-shaped metal sheet have a dimension in which respective leading end thereof can pass through the recess at mating.

Also in this configuration, it is possible to fix one pair of metal sheets with each other preliminarily by crimping the projecting piece at the locating parts on both long sides of the rectangular-shaped metal sheets. Therefore, it is possible to prevent the occurrence of displacement of the inner fin certainly in comparison with a case that the metal sheets are preliminarily fixed with each other at the locating parts on respective short sides of the rectangular-shaped metal sheets.

The projecting pieces in the all locating parts have a dimension in which respective leading end thereof can pass through the recesses.

In this configuration, it is possible to fix one pair of metal sheets with each other preliminarily by crimping the projecting piece at all of the locating parts. Therefore, it is possible to prevent the occurrence of displacement of the inner fin certainly.

The metal sheet has a substantially rectangular shape in plan view, and is two or more locating parts are arranged on each long side of the metal sheet.

Then, owing to the provision of two or more locating parts on each long side of the metal sheets, it is possible to improve the positioning accuracy of the metal sheets. Further, when the projecting pieces are crimped, the occurrence of displacement of the inner fin can be prevented certainly.

These and other objects and features of the present invention will become more fully apparent from the following description and appended claims taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view of a heat exchanger (evaporator) in accordance with the first embodiment of the present invention, also viewed from its upwind side;

FIG. 2 is a top view of the evaporator of FIG. 1;

FIG. 3 is a side view of the evaporator of FIG. 1, on the light side in the width direction of the evaporator;

FIG. 4 is a side view of the evaporator of FIG. 1, on the left side in the width direction of the evaporator;

FIGS. 5A to 5D are various views of a side plate of the evaporator of FIG. 1, on the left side in the width direction of the evaporator: FIG. 5A is a plan view of the side plate, FIG. 5B a view of the side plate viewed in the direction of arrow 5B of FIG. 5A, FIG. 5C a view of the side plate viewed in the direction of arrow 5C of FIG. 5A and FIG. 5D a view of the side plate viewed in the direction of arrow 5D of FIG. 5A;

FIGS. 6A to 6D are various views of another side plate of the evaporator of FIG. 1, on the right side in the width direction of the evaporator: FIG. 6A is a plan view of the side plate, FIG. 6B a view of the side plate viewed in the direction of arrow 6B of FIG. 6A, FIG. 6C a view of the side plate viewed in the direction of arrow 6C of FIG. 6A and FIG. 6D a view of the side plate viewed in the direction of arrow 6D of FIG. 6A;

FIGS. 7A to 7D are various views of a first metal sheet forming a tube of the evaporator of FIG. 1: FIG. 7A is a plan view of the first metal sheet, FIG. 7B a view of the first metal sheet viewed in the direction of arrow B of FIG. 7A, FIG. 7C a view of the first metal sheet viewed in the direction of arrow C of FIG. 7A and FIG. 7D a view of the first metal sheet viewed in the direction of arrow D of FIG. 7A;

FIGS. 8A to 8D are various views of a second metal sheet forming a tube of the evaporator of FIG. 1: FIG. 8A is a plan view of the second metal sheet, FIG. 8B a view of the second metal sheet viewed in the direction of arrow 8B of FIG. 8A, FIG. 8C a view of the second metal sheet viewed in the direction of arrow 8C of FIG. 8A and FIG. 8D a view of the second metal sheet viewed in the direction of arrow 8D of FIG. 8A;

FIG. 9A is an exploded perspective view of the tube, showing its lamination and FIG. 9B is a perspective view of the tube in its assembled state;

FIG. 10A is a sectional view of one pair of metal sheets before being crimped and FIG. 10B is a sectional view of the metal sheets after being crimped;

FIG. 11 is a sectional view of a tank part of the tubes, showing its lamination;

FIG. 12 is a schematic view of the evaporator, showing the flow of coolant therein;

FIG. 13A is a schematic view showing the distribution of liquid-phase coolant in two heat exchanging parts (evaporator parts) and FIG. 13B is a schematic view showing the distribution of liquid-phase coolant in the evaporator parts in combination;

FIG. 14 is a perspective view showing a modification of the metal sheets forming a tube of the evaporator of the first embodiment of the present invention;

FIG. 15 is a perspective view showing the metal sheets forming a tube of the evaporator of the second embodiment of the present invention; and

FIG. 16 is a perspective view showing the metal sheets forming a tube of the evaporator of the third embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to accompanying drawings, embodiments of the present invention will be described below.

[1st. Embodiment]

FIGS. 1 to 13B show the first embodiment of the present invention. According to the first embodiment of the invention, a heat exchanger is embodied by an evaporator 1 interposed in a refrigeration cycle of an automotive air conditioner. In arrangement, the evaporator 1 is positioned in an air-conditioner casing inside an instrument panel of a vehicle to carry out heat exchange between coolant flowing in the evaporator and air passing through the outside of the evaporator. Due to this heat exchange, the coolant is evaporated to cool down the air.

First of all, the whole structure of the evaporator 1 will be described with reference to FIG. 12.

The evaporator 1 includes two heat exchanging parts 10, 20 juxtaposed on upwind and downwind sides, respectively.

The “downwind-side” heat exchanging part 10 has an upper tank 11, a lower tank 12 and a plurality of heat exchanging passages between the tanks 11 and 12. These heat exchanging passages are also communicated with the tanks 11, 12. Similarly, the “upwind-side” heat exchanging part 20 has an upper tank 21, a lower tank 22 and a plurality of heat exchanging passages between the tanks 21 and 22. As well, these heat exchanging passages are communicated with the tanks 21, 22.

In the downwind-side heat exchanging part 10, the upper tank 11 is partitioned to a first upper tank part 11a and a second upper tank part 11b by a partition 14, while the lower tank 12 is partitioned to a first lower tank part 12a and a second lower tank part 12b by a partition 15. The upper tank 11 is provided, on its right side, with an evaporator inlet 7. The stacked heat exchanging passages are divided into a first path 10a, a second path 10b and a third path 10c in order from the right. Consequently, the coolant introduced into the downwind-side heat exchanging part 10 via the evaporator inlet 7 flows through the first upper tank part 11a, the first path 10a, the first lower tank part 12a, the second path 10b, the second upper tank part 11b, the third path 10c and the second lower tank part 12b, in this order. Then, the coolant is introduced from the most downstream side (i.e. the second lower tank part 12b) of the downwind-side heat exchanging part 10 into the most upstream side (i.e. the first lower tank part 22a) of the upwind-side heat exchanging part 20 through a communication passage 9. That is, the downwind-side heat exchanging part 10 constitutes an “inlet-side” heat exchanging part on the upstream side of the coolant's flow, while the upwind-side heat exchanging part 20 constitutes an “outlet-side” heat exchanging part on the downstream side of the coolant's flow.

In the upwind-side heat exchanging part 20, the lower tank 22 is partitioned to a first lower tank part 22a and a second lower tank part 22b by a partition 24, while the upper tank 21 is partitioned to a first upper tank part 21a and a second upper tank part 21b by a partition 25. The upper tank 21 is provided, on its light side, with an evaporator outlet 8. The stacked heat exchanging passages are divided into a first path 20a, a second path 20b and a third path 20c in order from the light. Consequently, the coolant introduced into the upwind-side heat exchanging part 20 via the communication passage 9 flows through the first lower tank part 22a, the first path 20a, the first upper tank part 21a, the second path 20b, the second lower tank part 22b, the third path 20c and the second upper tank part 21b, in this order. Then, the coolant is discharged from the evaporator 1 through the evaporator outlet 8 on the right side of the second upper tank part 21b as the most downstream part of the upwind-side heat exchanging part 20 on the outlet-side of the coolant's flow.

In the evaporator 1, the heat exchanging parts 10, 20 are each divided into the plural paths (e.g. three paths each in the shown example, that is, the paths 10a, 10b, 10c and the paths 20a, 20b, 20c) so as to have the same reference number in each of the parts 10, 20. Further, in the opposing paths overlapped on both “upwind” and “downwind” sides (for example, the first path 10a of the part 10 and the third path 20c of the part 20), the flowing directions of the coolant therein are opposite to each other, vertically and horizontally, including the coolant's flows in the tank parts on the upstream and downstream sides of the opposing paths. With this coolant's passage structure mentioned above, when superimposing the heat exchanging part 10 on the heat exchanging part 20 along the draft direction, it is possible to eliminate an exchanger area where the liquid-phase coolant L does not flow, as shown in FIGS. 13A and 13B. As a result, the evaporator 1 can be provided with even distribution in temperature and high efficiency in heat exchange.

The constituents of the evaporator 1 (i.e. tubes 30, side plates 34, 35 and piping connectors 36, etc.) will be described below.

As shown in FIGS. 1 to 4, the evaporator 1 of this embodiment includes a plurality of tubes 30 stacked on each other and a plurality of outer fins 33 each interposed between the adjoining tubes 30. Each tube 30 is provided by reversing one metal sheet 40 (40A), further overlapping it on another metal sheet 40 (40B) and further welding the periphery of the sheet 40A to the periphery of the sheet 40B while forming coolant passages in the tube 30. Further, the evaporator 1 is provided, on the outermost sides in the laminating direction of the tubes 30, with side plates 34, 35 for reinforcement, providing a designated configuration.

As shown in FIGS. 3, 6A, 6B, 6C and 6D, the side plate 34 is provided with a communication port 34a communicating with the most upstream part (the first upper tank part 11a) of the heat exchanging part 10 and another communication port 34b communicating with the most downstream part (the second upper tank part 21a) of the heat exchanging part 20. A piping connector 36 forming the inlet 7 and the outlet 8 of the evaporator 1 is attached to the communication ports 34a, 34b. The other side plate 35 (see FIGS. 4 and 5A to 5D) has a communication passage 9 formed integrally to communicate the most downstream part of the part 10 (i.e. the second lower tank part 12b) with the most upstream part of the part 20 (i.e. the first lower tank part 12a). Noted that reference numerals 35b denote reinforcing protrusion parts formed on the side plate 35, while reference numeral 37 denotes a reinforcing plate which is fitted to the side plate 34 to form a coolant passage and arranged between the side plate 34 and the piping connector 36.

The constitution of the tube 30 will be described below.

FIG. 9A is an exploded perspective view of the tube 30, showing its lamination. FIG. 9B is a perspective view of the tube 30 in its assembled state. FIGS. 7A to 7D show the metal sheet 40 (40A or 40B) forming the tube 30. As shown in FIG. 7A, the metal sheet 40 is shaped to be substantially rectangular in plan view. In noted that the metal sheet 40A has a configuration identical to that of the metal sheet 40B. The metal sheet 40B corresponds to an element that can be obtained by turning over R the metal sheet 40A about a “top-and-back” inversion axis X, and vice versa. The metal sheets 40A and 40B are mated to form the tube 30.

The tube 30 is provided with heat exchanging passages 31, 31 that perform heat exchange between the coolant flowing in the passages 31, 31 and air flowing outside the tube 30. The heat exchanging passages 31, 31 are formed by one heat exchanging passage 31 for the “downwind-side” heat exchanging part and another heat exchanging passage 31 for the “upwind-side” heat exchanging part. On both ends of the tube 30 in the longitudinal direction, cylindrical tank parts 32, 32 are formed so as to project from the both ends of each heat exchanging passage 31 to the outside. That is, each of the metal sheets 40A, 40B forming the tube 30 includes two grooves 41, 42 for a heat-exchanging passage, extending along the longitudinal direction and four tank parts 43, 44, 45, 46.

A plurality of projecting pieces 47 and recesses 48 are formed in the outer circumference of the metal sheet 40. The projecting pieces 47 and the recesses 48 are symmetrically arranged about the top-and-back inversion axis X. That is, if making the metal sheet 40A opposing the metal sheet 40B, then the projecting pieces 47 oppose the recesses 48 respectively. Subsequently, when overlapping the metal sheet 40A on the metal sheet 40B, the projecting pieces 47 are inserted into the recesses 48, so that the resulting engagements between the projecting pieces 47 and the recesses 48 allow the metal sheets 40A, 40B to be located to each other. These locating elements having the projecting pieces 47 and the recesses 48 in engagement are provided on respective sides 40a, 40b, 40c, 40d of the metal sheet 40 (or the tube 30).

According to the embodiment, all of the projecting pieces 47 are shaped with dimensions so that their leading ends pass through the recesses 48 when fitting the metal sheet 40A to the metal sheet 40B while interposing two inner fins 61, 61 therebetween. Subsequently, as shown in FIGS. 10A and 10B, the crimping of the projecting pieces 47 allows the metal sheets 40A, 40B to be caulked thereby fixing the tube 30 preliminarily.

It is noted in the shown embodiment that the above top-and-back inversion axis X is identical to a sheet's center line extending along the direction perpendicular to the longitudinal direction of the metal sheet 40, namely, a center line for dividing the metal sheet 40 into two equal parts in the longitudinal direction of the sheet 40.

In the manufacturing process (see FIG. 9) of the evaporator 1, the tubes 30 in such a preliminarily fixed condition are laid to overlap on each other into a preliminary assembly as shown in FIGS. 1 to 4. Thereafter, the preliminary assembly is carried by a not-shown jig and transferred into a furnace for welding the preliminary assembly. Noted that FIGS. 9A and 9B do not illustrate the outer fin 33 for convenience of understanding. According to the above-mentioned manufacturing process, if possible to position the adjoining tubes 30, then it becomes possible to automatize the laminating operation of the tubes 30, whereby the manufacturing cost can be saved. That is, the possibility of positioning the metal sheets 40A, 40B in their addorsed (back-to-back) condition would allow the laminating operation of the tubes 30 to be automated thereby reducing the manufacturing cost of the evaporator 1. Therefore, as shown in FIGS. 7A and 7B, in the tank parts 43, 44 (45, 46) on both sides of the groove 41 (42), one tank part 43 (46) is provided, on the periphery of its opening end 43a (46a), with an engagement projection 49 as locating parts (locating means). Owing to the provision, when the engagement projection 49 of the tank part 43 (46) is inserted into the opening end 44a (45a) of the other tank part 44 (45), the metal sheets 40A, 40B in their addorsed (back-to-back) can be positioned in relation with each other. In other words, the metal sheets 40 (40A, 40B) are respectively shaped so as to be symmetrical to each other about the top-and-back inversion axis X except the projecting pieces 47, the recesses 48 and the engagement projection 49.

Also noted that not only the metal sheet 40 of FIGS. 7A and 7B but a second metal sheet 50 of FIGS. SA and 8B is employed in this embodiment. The second metal sheet 50 is provided with an “intecral-molding” partition 51 serving as one of the aforementioned partitions 14, 15, 24, 25 (see FIG. 12) for dividing the heat exchanging parts 10, 20 into the paths 10a, 10b, 10c, 20a, 20b and 20c. It is noted that this metal sheet 50 is nothing but a metal sheet where one tank part 43 in the four tank parts 43, 44, 45, 46 of the first metal sheet 40 is replaced by the partition 51. Depending on the position(s) of the second metal sheet(s) 50 to be inserted into a lamination of the tubes 30, the compartmentalization of these paths 10a, 10b, 10c, 20a, 20b and 20c is determined in the heat exchanging parts 10, 20. Note, in FIGS. 1 and 2, reference numerals 50A, 50B, 50C, 50D denote the same metal sheets 50 though some of them are inverted inside and out in the arrangement of the heat exchanger.

The effects of the first embodiment will be summarized below.

First of all, it should be noted that the metal sheets 40A, 40B are respectively provided, around their outer circumferential edges, with the projecting pieces 47 projecting toward the reverse side of each metal sheet and the recesses 48 allowing insertion of the projecting pieces 47 and that the locating parts each having the projecting piece 47 and the recess 48 in combination are provided on the sides 40a, and 40d of each metal sheet 40A (40B), respectively. Therefore, the assembling accuracy of one pair of metal sheets 40A, 40B is so improved as to make their weld smaller, whereby it is possible to make the heat exchanger 1 thin.

Moreover, it is noted that each of the metal sheets 40A, 40B is shaped so as to be symmetrical about the top-and-back inversion axis X that is a center line of the metal plate 40A (40B) alone the direction perpendicular to the longitudinal direction and that the projecting pieces 47 are arranged in symmetry with the recesses 48 about the top-and-back inversion axis X. Therefore, it is possible to form the metal sheet 40A and the metal sheet 40B of identical configurations. Thus, in spite of the provision of the projecting pieces 47 and the recesses 48 in order to improve the assembling accuracy, it is unnecessary to prepare metal sheets of difference configurations, whereby the rise in manufacturing cost can be avoided.

Second, since all of the projecting pieces 47 are formed so that their leading ends pass through the recesses 48 respectively at all of the locating parts each having the projecting piece 47 and the recess 48 in engagement, it is possible to preliminarily fix the metal sheets 40A, 40B with each other by folding (crimping) the leading ends of the projecting pieces 47 inwardly. Therefore, the displacement of the inner fin can be prevented certainly.

Third, since each of the long sides 40a, 40b is provided with two or more locating parts each having the projecting piece 47 and the recess 48 to be mated each other, it is possible to improve the positioning accuracy between the metal plates 40A, 40B furthermore. Additionally, it is possible to prevent the displacement of the inner fin.

Further, as for the modification of FIG. 14 of the first embodiment of the invention, it goes without saying that there can be produced the similar operation and effects in spite of the presence of difference in the positions of the projecting pieces 47 and the recesses 48 on the long sides 40a, 40b.

[2nd. Embodiment]

The second embodiment of the present invention will be described below. FIG. 15 shows the second embodiment of the present invention. In this embodiment, elements identical to those in the first embodiment will be indicated with the same reference numerals, respectively. Additionally, overlapping descriptions in terms of constitution and effect of the elements are eliminated.

The second embodiment differs from the first embodiment in that a “top-and-back” inversion axis Y for a metal sheet 140A (140B) is a center line extending along the longitudinal direction of the sheet 140A (140B) (i.e. a center line for dividing the sheet 140A into two equal parts in the direction perpendicular to the longitudinal direction) and the projecting pieces 47 are arranged in symmetry with the recesses 48 about the top-and-back inversion axis Y Additionally, according to the second embodiment, the assembly of the metal sheets 140A, 140B is provided, on each of the short sides 40c and 40d, with two locating parts each having the projecting piece 47 and the recess 48 in engagement and also provided, on each of the long sides 40a and 40b, with one locating part having the projecting piece 47 and the recess 48 in engagement, which is different from the first embodiment.

According to the second embodiment, it should be noted that the metal sheets 140A, 140B are respectively provided, around their outer circumferential edges, with the projecting pieces 47 projecting toward the reverse side of each metal sheet and the recesses 48 allowing insertion of the projecting pieces 47 and that the locating parts each having the projecting piece 47 and the recess 48 in combination are provided on the sides 40a, . . . and 40d of each metal sheet 140A (140B), respectively. Therefore, the operations and effects are similar to those of the first embodiment.

Moreover, it is noted that, except the projecting pieces 47 and the recesses 48, the metal sheet 140A is shaped so as to be symmetrical to the metal sheet 140B about the top-and-back inversion axis Y and that the projecting pieces 47 are arranged in symmetry with the recesses 48 about the top-and-back inversion axis Y Therefore, it is possible to form the metal sheet 140A and the metal sheet 140B of identical configurations. Thus, in spite of the provision of the projecting pieces 47 and the recesses 48 in order to improve the assembling accuracy, it is unnecessary to prepare metal sheets of difference configurations, whereby the rise in manufacturing cost can be avoided.

Noted that, due to two locating parts on each of the long sides 40a, 40b of the metal sheet 40A (40B), the first embodiment is superior to the second embodiment in view of the positioning accuracy of the metal sheets and the prevention of displacement of the inner fin after crimping the projecting pieces.

[3rd. Embodiment]

The third embodiment of the present invention will be described below. FIG. 16 shows the third embodiment of the present invention. In this embodiment, elements identical to those in the first embodiment will be indicated with the same reference numerals respectively and their overlapping descriptions are eliminated.

The third embodiment differs from the first and second embodiments in that a metal sheet 240A is shaped so as to be symmetrical to another metal sheet 240B about two “top-and-back” inversion axes X and Y and that the projecting pieces 47 are arranged in symmetry with the recesses 48 about the top-and-back inversion axes X and Y.

According to the third embodiment, since one metal sheet 240A (240B) may be reversed about either one of the top-and-back inversion axes X and Y in order to be the other metal sheet 240B (240A), the third embodiment is superior to the first and second embodiments in terms of its versatility. Noted that the inner fin is not shown in FIGS. 14 to 16.

In summary, according to the present invention, there are provided a plurality of locating parts on the respective sides of the outer circumferential edges of metal sheets in pairs, wherein each of the locating part has a projecting piece and a recess that engage with each other when one metal sheet is reversed to overlap on the other metal sheet. That is, owing to the provision of the locating parts, the assembling accuracy of the metal sheets is so improved as to make their weld smaller, whereby it is possible to make the heat exchanger thin.

Moreover, according to the present invention, each metal sheet is shaped so as to have a symmetrical configuration about a “top-and-back” inversion axis (X, Y) or “top-and-back” inversion axes (X and Y) and thereupon, the projecting pieces are arranged in symmetry with the recesses about the top-and-back inversion axis (axes). Therefore, it is possible to form the pair of metal sheet of identical configurations. Thus, in spite of the provision of the projecting pieces and the recesses in view of the improvement in assembling accuracy, it is unnecessary to prepare metal sheets of difference configurations, whereby the use in manufacturing cost can be avoided.

Finally, it will be understood by those skilled in the art that the foregoing descriptions are nothing but three embodiments of the disclosed heat exchanger and therefore, various changes and modifications may be made within the scope of claims.

Claims

1. A heat exchanger, comprising:

a heat exchanging part including laminated tubes each of which has a pair of metal sheets joined to each other, each of the tubes having heat exchanging passage formed therein to extend along the longitudinal direction of the tube, and cylindrical tank parts formed at both ends of each heat exchanging passage to project from a main body of the tube, the cylindrical tank parts of the adjoining tubes connected with each other in communication with each other,
wherein the metal sheets have at least one top-and-back inversion axis about which one metal sheet is in inverse relation to the other metal sheet, and
wherein each metal sheet has a plurality of projecting pieces formed on the outer circumferential edge of the metal sheet so as to project toward a mate to the metal sheet and a plurality of recesses formed on the outer circumferential edge of the metal sheet so as to allow the projecting pieces to be inserted thereinto respectively, the projecting pieces being respectively arranged symmetrically to the recesses about the top-and-back inversion axis, thereby the projecting piece and the recess constituting a locating part when the metal sheets are mated, the locating parts are provided on at least respective sides of the metal sheet, respectively.

2. The heat exchanger of claim 1, wherein the top-and-back inversion axis comprises a center line of the metal sheet in a longitudinal direction of the metal sheet.

3. The heat exchanger of claim 1, wherein the top-and-back inversion axis comprises a center line of the metal sheet in a direction perpendicular to a longitudinal direction of the metal sheet.

4. The heat exchanger of claim 1, wherein the laminated tubes constitute a pair of heat exchanging parts which are arranged side by side.

5. The heat exchanger of claim 1, further comprising an inner fin which is disposed in the heat exchanging passage formed in the tube, wherein the projecting piece in at least one of the locating parts has a dimension in which a leading end thereof can pass through the recess at mating.

6. The heat exchanger of claim 5, wherein the projecting pieces in the locating parts allocated on at least opposing sides of the metal sheets have a dimension in which respective leading end thereof can pass through the recess at mating.

7. The heat exchanger of claim 5, wherein

the metal sheet has a substantially rectangular shape in plan view, and
the projecting pieces in the locating parts allocated on both long sides of the rectangular-shaped metal sheet have a dimension in which respective leading end thereof can pass through the recess at mating.

8. The heat exchanger of claim 5, wherein the projecting pieces in the all locating parts have a dimension in which respective leading end thereof can pass through the recesses.

9. The heat exchanger of the claim 1, wherein

the metal sheet has a substantially rectangular shape in plan view; and
two or more locating parts are arranged on each long side of the metal sheet.
Patent History
Publication number: 20050039895
Type: Application
Filed: Jul 22, 2004
Publication Date: Feb 24, 2005
Inventors: Hiroyuki Inaba (Kitakatsushika-gun), Hiroyuki Katori (Saitama-shi)
Application Number: 10/896,586
Classifications
Current U.S. Class: 165/153.000; 165/176.000