HEAT EXCHANGER
A fin has a U-form cutaway portion into which a flat tube is fitted and a fin collar standing inclined from an edge portion of the cutaway portion, and an opened end width W2 of the cutaway portion is formed to be larger than an outer width W1 of the flat tube. Also, the fin collar has a fin collar inclined face portion standing inclined with respect to a fin flat face from the edge portion of the cutaway portion, and a fin collar end face portion bent from an end portion of the fin collar inclined face portion and in surface contact with an outer face of the flat tube.
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The present invention relates to a fin-and-tube heat exchanger in which a flat tube is used.
BACKGROUND ARTAn existing fin-and-tube heat exchanger in which a flat tube is used is manufactured using a manufacturing device such that a position of a flat tube is regulated by the flat tube being fitted between restraining pins, fins are held in a mounting drum that carries out a rotary movement, and the fins are sequentially mounted in the flat tube while the mounting drum is rotated (for example, refer to Patent Document 1).
CITATION LIST Patent LiteraturePatent Document 1: JP-A-2013-59847
SUMMARY OF INVENTION Technical ProblemThe heat exchanger disclosed in Patent Document 1 is such that a force is exerted whereby the flat tube attempts to push apart a closed end portion of a U-form cutaway portion for fitting the fin into the flat tube. Because of this, there is a problem in that when the restraining pins regulating the position of the flat tube are removed, the fin becomes deformed, and warping occurs in a step direction of the flat tube, of which a multiple are disposed.
Further, when warping in the step direction of the flat tube increases at a manufacturing stage of mounting the fin in the flat tube, there is a case in which the fin can no longer be inserted into the flat tube. When the heat exchanger manufacturing device is operated in a state in which the fin cannot be inserted into the flat tube, there is concern that a problem such as a fin mounting plate and the flat tube colliding will occur, and the manufacturing device will stop due to damage.
The invention, having been contrived in order to resolve the heretofore described kind of problem, has an object of employing a cutaway portion form such that a force that attempts to push apart a closed end of a fin cutaway portion when fitting the fin into a flat tube can be restricted, reducing warping in a step direction of the flat tube, and preventing damage to the flat tube and a fin mounting plate.
Solution to ProblemA heat exchanger according to the invention includes a multiple of a flat tube that forms a passage of a heat conducting medium and whose cross-section is of a flat form, and a multiple of a fin, fixed to the flat tube, whose main flat face is perpendicular to a passage direction of the flat tube, and which is disposed at intervals in the passage direction, wherein the fin has a cutaway portion into which the flat tube is fitted and a fin collar standing erect from an edge portion of the cutaway portion, an opened end of the cutaway portion is larger than an outer width of the flat tube, and the fin collar has a fin collar inclined face portion standing inclined with respect to a fin flat face from the edge portion of the cutaway portion, and a fin collar end face portion bent from an end portion of the fin collar inclined face portion and in surface contact with an outer face of the flat tube.
Advantageous Effects of InventionAccording to the heat exchanger of the invention, an opened end of a cutaway portion is larger than an outer width of a flat tube, because of which deformation of a fin when fitting the fin on the flat tube can be restricted, and as a fin collar end face portion of a fin collar is in surface contact with an outer face of the flat tube, the fin and the flat tube can be fixed, and thermal conductivity between the two can be secured.
A heat exchanger of a first embodiment of the invention will be described, using
The fin 2 is of a flat plate form, and a multiple thereof are mounted in parallel at constant intervals in a longitudinal direction of the flat tube 1, that is, a passage direction of a heat conducting medium. The flat tube 1 is such that a cross-section perpendicular to the passage direction is of a flat form, a multiple thereof are disposed in parallel with outer peripheral planes (outer faces) of neighboring flat tubes 1 opposing each other, and a fluid forming a heat conducting medium, such as water or a refrigerant, flows through an interior of each flat tube 1.
An opened form of the cutaway portion 21a is a U-form, and in a state in which the fin 2 and the flat tube 1 are fitted, one semi-circular end portion of the flat tube 1 is fitted into a semi-circular portion (an R portion) forming a closed end of the cutaway portion 21a.
Also, an unshown slit is formed in each of flat portions 2a segregated by the cutaway portion 21a.
Further, a fin collar 22 for joining the flat tube 1 and the fin 2 closely is formed standing erect along an edge portion of each cutaway portion 21a on the same surface side of the fin 2.
The fin collar 22 and the unshown slit are formed protruding in the same direction with respect to the surface of the fin 2.
In this way, the fin 2 of the first embodiment of the invention has the cutaway portion 21a in which the flat tube 1 is fitted, and the fin collar 22 standing erect from the edge portion of the cutaway portion 21a toward the outer face of the flat tube 1, and the opened end width W2 of the cutaway portion 21a is offset so as to extend from the semi-circular portion of the closed end of the cutaway portion 21a, in order to be greater than the outer width W1 of the flat tube 1. The fin collar 22 has a fin collar inclined face portion 22a standing inclined with respect to a fin plane from the edge portion of the cutaway portion 21a, and a fin collar end face portion 22b bending from an end portion of the fin collar inclined face portion 22a and in surface contact with the outer face of the flat tube 1.
Because of this, an edge portion of the fin collar 22 of the fin 2 is not in a state of being in contact with the outer face of the flat tube 1, even when in a state of being fitted with the flat tube 1.
Fixing of the flat tube 1 and the fin 2 is carried out by joining the outer face of the flat tube 1 and the fin collar end face portion 22b of the fin 2, and thermal conductivity can be secured by the two being in surface contact.
Herein, the fin collar inclined face portion 22a of the fin 2 is formed in a state extending from two parallel linear edge portions extending from the opened end to the closed end of the U-form cutaway portion 21a, and standing erect opposing the outer face of the flat tube 1 at an angle of less than 90 degrees with respect to the flat portion 2a of the fin 2. At this time, as shown in
Also, as previously described, a fluid such as water or a refrigerant is caused to flow through the interior of the flat tube 1, but owing to the cross-section being of a flat form, an amount of the fluid such as water or a refrigerant can be increased without causing an increase in ventilation resistance in comparison with a circular tube. Because of this, performance as the heat exchanger 100 can be improved. That is, when compared as having the same performance, the heat exchanger 100 in which the flat tube 1 is used has an advantage in that size can be reduced in comparison with an existing heat exchanger in which a circular tube is used.
As shown in
As shown in
Further, as shown in
Manufacture of the heat exchanger 100 is such that before assembling the fin 2, a number of the flat tubes 1 set in accordance with a required cooling and heating performance are disposed in parallel at predetermined intervals. Further, the fin-and-tube is manufactured by all of the multiple of flat tubes 1 disposed in parallel being restrained using the flat tube restraining function, and a necessary number of fins 2 being mounted at predetermined intervals on the restrained flat tubes 1 using the fin mounting function.
The fin mounting function will be described in detail using
The fin mounting plate 121 holding the fin 2 rotates in the direction of the arrow A around the axis X, and stops in a position perpendicular with respect to the flat tube 1 in a lower portion of (directly below) the drum 122, owing to the drum 122 performing one-half of a rotation.
Subsequently, by the fin 2 held by vacuum suctioning being released from the fin mounting plate 121 by vacuum breaking, the fin 2 can be mounted on the outer peripheral face of the flat tube 1.
Next, the fin mounting plate 121 that releases the fin 2 rotates owing to the drum 122 rotating further, but it is necessary here that the fin mounting plate 121 operates so as not to interfere with the fin 2 mounted on the flat tube 1. For the purpose of this operation, a cam follower 124 is attached to the fin mounting plate 121. Furthermore, an unshown cam is disposed in a rotational center portion of the drum 122. By the cam follower 124 following the cam in accompaniment to the drum 122 rotating, the position of the fin mounting plate 121 is controlled, and a configuration such that the fin mounting plate 121 does not interfere with the fin 2 can be adopted.
Next, the movement function of the flat tube 1 will be described in detail. A kind of flat tube restraining portion 300 shown in
In
Because of this, the multiple of flat tubes 1 are arranged at equal pitches in the width direction of the flat tube 1. The flat tube restraining function is such that, while the heretofore described kind of fin mounting operation is being carried out, movement is carried out by the movement function while the flat tube 1 is constantly restrained (in contact). That is, the restraining pin 301 and the flat tube 1 are in a state of being in contact. Therefore, a material with excellent abrasion resistance is selected for the restraining pin 301.
The flat tube restraining portion 300 shown in
Herein, a case in which the restraining pins 301 are disposed in two rows, and the pins positioned on either side of the multiple of flat tubes 1 are set so as to be in the same row, is shown in the example of
After the fin 2 is mounted on the flat tube 1 by the manufacturing device of
Next,
Consequently, even when retracting the flat tube restraining portion 300, and removing the flat tube restraining portion 300 from the heat exchanger 100 being manufactured, in a step of sequentially mounting the fins 2 on the flat tube 1 in the manufacturing process of the heat exchanger 100, the fin mounting plate 121 and the flat tube 1 no longer interfere, because of which the fin 2 can be mounted as far as a fin mounting terminus portion of the flat tube 1, thereby completing the heat exchanger 100.
Next, using
As heretofore described, the fin collar 22 includes the fin collar inclined face portion 22a, but the fin collar inclined face portion 22a can be a fin collar inclined face portion 22aa formed of a flat face, as shown in
As shown in
Herein, a perspective view of a fin 200 that forms a comparative example is shown in
Next,
As shown in a middle view of
However, at a stage at which the flat tube 1 is removed from the flat tube restraining portion 300, the width of the opened end of the narrow cutaway portion 210 increases, and warping occurs in a longitudinal direction of the fin 200, as shown in a lower view of
The comparative example shown in
A case in which the width W2 of the opened end of the cutaway portion 21a is greater than the width W1 of the closed end, and the two linear edge portions of the cutaway portion 21a, which is of a U-form, are parallel, is shown as an example in the first embodiment, but the cutaway portion 21b of the fin 2 according to the second embodiment, as shown in
Also, as the aperture of the cutaway portion 21b is formed to be greater the nearer to the opened end, as shown in
Forming a fin collar end face portion 23b bent from an end portion of the fin collar inclined face portion 23a is the same as forming the fin collar end face portion 22b of the first embodiment.
With regard to the size of the upright width of the fin collar inclined face portion 23a, however, an example such that the upright width is greater the nearer to the opened end of the cutaway portion 21b, and smaller the nearer to the closed end, is shown in
As heretofore described, the form of the cutaway portion 21b of the fin 2 need not necessarily be of the kind of constant width (W2) shown in
Further, a state wherein the flat tube 1 and the fin 2 are joined with no gap is obtained in a position near the closed end of the cutaway portion 21b, whereby good contact between the flat tube 1 and the fin collar 23 after the fin 2 is mounted on the flat tube 1 can be secured.
Third EmbodimentAn example wherein the multiple of cutaway portions 21a or 21b formed in the fin 2 are all of the same form is shown in the first embodiment or the second embodiment. However, a multiple of cutaway portions formed in one fin 2 need not all be of the same form. Cutaway portions of differing forms can be used in combination.
For example, the fin 2 formed employing two kinds of cutaway portion of differing aperture widths, wherein the narrow cutaway portion 210 shown as a comparative example of the first embodiment and the cutaway portion 21b shown in the second embodiment are disposed alternately, can be used, as shown in
Not being limited to this, three or more kinds of cutaway portion may be provided in the fin 2, and the most appropriate kinds may be selected and employed. Furthermore, with regard to the distribution of cutaway portions in one fin 2, the distribution need not necessarily be of a form such that differing kinds of cutaway portion are disposed alternately. For example, it goes without saying that the cutaway portion form can be changed every two cutaway portions, or cutaway portion forms can be distinguished between depending on a mounting region.
The cutaway portions 21a and 21b of the fin 2 shown in the first embodiment and the second embodiment are such that although a force that attempts to push apart the closed end side of the fin 2 is no longer generated, there is a tendency for contact force between the flat tube 1 and the fin 2 to decrease. Therefore, in order to supplement the contact force between the flat tube 1 and the fin 2, one portion of the multiple of cutaway portions are replaced in the fin 2 with the narrow cutaway portion 210 of the width W3 slightly smaller than the width W1 of the flat tube 1, as shown in
Also, as shown in
An example wherein the fin collars 22 and 23 are provided with line symmetry across a central line passing through a closed end apex of the cutaway portion 21a or the cutaway portion 21b, and left and right fin collar forms are the same, is shown in the first embodiment and the second embodiment.
In the fourth embodiment, a case in which fin collars standing erect from left and right edge portions of the cutaway portions 21c, 21d, and 21e are of differing forms will be described.
As shown in
The cutaway portion 21c of the fin 2 shown in
The structure of the fin 2 shown in
Of two linear edge portions of a cutaway portion of the fin 2 in which the flat tube 1 is to be fitted, the fin collar 22 of the first embodiment is formed on a left side edge portion, and a fin collar 220 of an existing structure is formed on a right side edge portion, as shown in
The fin 2 including the fin collar 22 is such that an opened end of the cutaway portion 21d is larger than a closed end, the fin collars 22 and 220 standing erect one from each of the two linear edge portions of the cutaway portion 21d are of differing forms, the edge portion on the side on which the fin collar 22 is formed is positioned on a line connecting a position offset in a direction in which the cutaway portion 21d spreads from a closed end semi-circular portion and the opened end, the edge portion on the side on which the fin collar 220 is formed is positioned on a line connecting the opened end and the closed end, and the two are disposed in parallel. The cutaway portion 21d is such that an opened end width and the aperture width W4 on the closed end side are of the same dimension, which is greater than the width W1 of the closed end (the semi-circular portion).
Furthermore, a structure such that the fin collar 23 of the second embodiment is formed on a left side edge portion of the cutaway portion 21e of the fin 2, and the fin collar 220 is formed on a right side edge portion, can also be adopted, as shown in
It goes without saying that the cutaway portions 21c, 21d, and 21e of the fin 2 shown in
By the forms of the cutaway portions 21c, 21d, and 21e of the fin 2 shown in
Also, it goes without saying that the cutaway portions 21c, 21d, and 21e shown in
The embodiments of the invention can be freely combined, and each embodiment can be modified or abbreviated as appropriate, without departing from the scope of the invention.
Claims
1. A heat exchanger, comprising:
- a multiple of a flat tube that forms a passage of a heat conducting medium and whose cross-section is of a flat form; and
- a multiple of a fin, fixed to the flat tube, whose main flat face is perpendicular to a passage direction of the flat tube, and which is disposed at intervals in the passage direction, wherein
- the fin has a cutaway portion into which the flat tube is fitted and a fin collar standing erect from an edge portion of the cutaway portion,
- an opened end of the cutaway portion is larger than an outer width of the flat tube,
- an aperture form of the cutaway portion is U-form, one semi-circular end portion of the flat tube is fitted into a semi-circular portion forming a closed end of the cutaway portion, and
- the fin collar has a fin collar inclined face portion standing inclined with respect to a fin flat face from the edge portion of the cutaway portion, and a fin collar end face portion bent from an end portion of the fin collar inclined face portion and in surface contact with an outer face of the flat tube.
2. The heat exchanger according to claim 1, wherein
- the fin collar inclined face portion extends from two linear edge portions reaching from the opened end to the closed end of the cutaway portion, and stands erect facing the outer face of the flat tube at an angle of less than 90 degrees with respect to the fin flat face.
3. The heat exchanger according to claim 2, wherein
- the opened end of the cutaway portion is larger than the closed end, and the two linear edge portions of the cutaway portion are parallel.
4. The heat exchanger according to claim 2, wherein
- the opened end of the cutaway portion is larger than the closed end, and each of the two linear edge portions of the cutaway portion is positioned on a line connecting the opened end and the closed end.
5. The heat exchanger according to claim 1, wherein
- the fin collar inclined face portion and the fin collar end face portion are both flat faces.
6. The heat exchanger according to claim 1, wherein
- the fin collar inclined face portion is a curved face, and the fin collar end face portion is a flat face.
7. The heat exchanger according to claim 1, wherein
- the fin has a narrow cutaway portion whose opened end is smaller than the outer width of the flat tube in addition to the cutaway portion.
8. The heat exchanger according to claim 7, wherein
- the cutaway portion and the narrow cutaway portion are alternately disposed in an end portion of the fin.
9. The heat exchanger according to claim 2, wherein
- the opened end of the cutaway portion is larger than the closed end, fin collars standing erect from each of the two linear edge portions of the cutaway portion are of differing forms, one of the edge portions is positioned on a line parallel to the main flat face of the flat tube, and the other of the edge portions is positioned on a line connecting the opened end and the closed end.
10. The heat exchanger according to claim 2, wherein
- the opened end of the cutaway portion is larger than the closed end, fin collars standing erect from each of the two linear edge portions of the cutaway portion are of differing forms, one of the edge portions is positioned on a line connecting a position offset in a direction in which the cutaway portion spreads from the closed end and the opened end, and the other of the edge portions is positioned on a line connecting the opened end and the closed end.
Type: Application
Filed: Feb 3, 2017
Publication Date: Nov 8, 2018
Applicant: MITSUBISHI ELECTRIC CORPORATION (Chiyoda-ku, Tokyo)
Inventor: Toshimichi Baba (Tokyo)
Application Number: 15/779,912