JP2018112363A - Flat tube, fin tube type heat exchanger, and manufacturing method for fin tube type heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flat tube capable of suppressing a reduction in wall thickness due to tube expansion so as to enable stable tube expansion, and a fin tube type heat exchanger using the flat tube, and a manufacturing method for the fin tube type heat exchanger.SOLUTION: A flat tube 1 of a fin tube type heat exchanger is configured such that a tube expansion component is inserted for tube expansion, into a central flow passage 11 positioned at a central part out of a plurality of flow passages whose transverse sections are formed into flat shapes and which are provided side-by-side in a long axis direction. At a tube thickness portion in a short axis direction where the center flow passage is formed, a tube thickness material accumulation part 13 is provided in a longitudinal direction of the tube, in which a tube thickness material suitable to the volume of a tube material extending in the long axis direction with the tube expansion is accumulated.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a flat tube having a plurality of flow paths, a fin tube heat exchanger using the flat tube, and a method of manufacturing the fin tube heat exchanger.

  As a fin-tube heat exchanger using a flat tube with a plurality of conventional channels, the flat tube and fins are tightly integrated, so the fin and flat tube are assembled and then the tube is expanded, or the flat tube shape There is one in which a fin and a tube having a smaller through hole (insertion hole) are assembled (for example, see Patent Document 1).

Japanese Patent Laid-Open No. 2005-164221

  An odd number of refrigerant flow paths are formed inside the flat tube, and the largest of the flow paths is provided at the center in the major axis direction and minor axis direction of the flat tube cross section. By inserting a pipe expansion billet into only the flow path provided at the center and expanding the pipe, the entire flat pipe (both in the long axis and the single axis) is expanded. In such a flat tube expanding method, the plate thickness (thickness) of the flat tube decreases around the expanded flow path. As a result, there was a problem that the initially assumed plate thickness could not be ensured and the pressure resistance decreased. Furthermore, since the pressure resistance is not lowered, there is a problem that the heat exchanger is enlarged when the plate thickness is increased as a whole. In addition, there is a countermeasure to prevent the refrigerant from flowing in the expanded flow path so as not to reduce the pressure resistance of the heat exchanger, but in that case, the flow rate of the heat exchanger decreases, so the performance of the heat exchanger decreases. There was a problem such as.

  The present invention has been made to solve the above-described problems, and is a flat tube capable of stably expanding the fin tube by suppressing a reduction in wall thickness due to the tube expansion, and a finned tube heat exchange using the flat tube. It aims at obtaining the manufacturing method of a heat exchanger and a fin tube type heat exchanger.

The flat tube according to the present invention can be expanded by inserting a tube expansion component into a central flow channel located in the central portion of a plurality of flow channels having a flat cross section and arranged in parallel in the longitudinal direction. In a flat tube for a finned tube heat exchanger, the tube thickness corresponding to the volume of the tube material extending in the long axis direction by the tube expansion is added to the tube axis portion in the short axis direction forming the central channel. A tube meat material reservoir portion in which the material is accumulated is provided along the longitudinal direction of the tube.
The finned tube heat exchanger according to the present invention has a flat cross section as a heat transfer tube that is engaged so as to pass through a plurality of fins and that has a flow passage through which a refrigerant flows. In the flat tube for a finned tube heat exchanger that can be expanded by inserting a tube expansion component into a central channel located in the central portion among a plurality of channels arranged in parallel in the long axis direction, In the longitudinal direction of the tube, the tubular material reservoir portion in which the tubular material corresponding to the volume of the tubular material extending in the major axis direction by the expansion is stored in the tubular portion in the short axis direction forming the central channel. A flat tube provided along the line is used.
Further, the manufacturing method of the finned tube heat exchanger according to the present invention is a heat transfer tube for the finned tube heat exchanger, wherein the transverse cross section is formed flat and arranged in parallel in the major axis direction, A tubular material reservoir portion in which a tubular material corresponding to the volume of the tubular material extending in the major axis direction by expansion is stored in a tubular portion of the short axis direction forming a central channel located in the central portion. When a flat tube provided along the longitudinal direction of the tube is used, and the flat tube is inserted through the insertion hole of the fin and expanded, the cross section of the maximum diameter portion is elliptical and the long axis direction is the length of the flat tube. A pipe expansion component matched with the axial direction is inserted through the central channel.

According to the flat tube of this invention, the tubular material in which the tubular material corresponding to the volume of the tubular material that extends in the major axis direction by expansion is stored in the tubular portion of the short axis that forms the central channel. By providing the reservoir part along the longitudinal direction of the pipe, the pipe material provided in the pipe material reservoir part extends in the long axis direction even if the central channel of the flat tube is expanded, and the elongated part It is possible to prevent the wall thickness from being reduced, and to prevent a decrease in pressure resistance of the flow path.
Moreover, according to the finned tube heat exchanger of the present invention, the pressure resistance characteristics of the flow path of the flat tube used as the heat transfer tube are maintained without being damaged, so that the reliability in terms of pressure resistance as the heat exchanger is maintained. In addition to improving the performance, the outer peripheral surface of the flat tube can be reliably brought into contact with the insertion hole of the fin, so that excellent heat exchange efficiency can be obtained.
Moreover, according to the manufacturing method of the fin tube type heat exchanger of this invention, when expanding a flat tube, the reduction | decrease of the thickness of a flat tube is suppressed and stable tube expansion can be performed.

It is a perspective view which shows notionally the principal part of the finned-tube heat exchanger by Embodiment 1 of this invention. It is sectional drawing which illustrates notionally the penetration part of the flat tube with respect to the fin in the manufacturing method of the flat tube and fin tube type heat exchanger by Embodiment 1 of this invention. It is sectional drawing which illustrates notionally the penetration part of the flat tube with respect to the fin in the manufacturing method of the flat tube and fin tube type heat exchanger by Embodiment 2 of this invention. It is sectional drawing which illustrates notionally the penetration part of the flat tube with respect to the fin in the manufacturing method of the flat tube and fin tube type heat exchanger by Embodiment 3 of this invention. It is a principal part perspective view which shows notionally the modification of the finned-tube type heat exchanger by Embodiment 3 of this invention. It is a perspective view which shows notionally the principal part of the flat tube by Embodiment 4 of this invention, and the fin tube type heat exchanger using the flat tube.

Embodiment 1 FIG.
FIG. 1 is a perspective view conceptually showing the main part of a finned tube heat exchanger according to Embodiment 1 of the present invention, and FIG. 2 is a production of flat tubes and finned tube heat exchangers according to Embodiment 1 of the present invention. It is sectional drawing which illustrates notionally the insertion part of the flat tube with respect to the fin in a method, (a) is before pipe expansion, (b) has shown after pipe expansion. In the figure, as shown in FIG. 2A, the flat tube 1 according to Embodiment 1 is formed in a substantially oval shape with a flat cross section before pipe expansion, and has a flow path for flowing refrigerant. A plurality are arranged side by side in the long axis direction. The number of the flow paths is an odd number, and the central flow path 11 located at the center is also used when inserting a tube expansion component (not shown) such as a tube expansion billet for expanding the flat tube 1. It is circular and has the largest cross-sectional area. On the other hand, a plurality of other flow paths 12 connected in the long axis direction (left and right direction in FIG. 2) have an elliptical shape with a smaller cross-sectional area than the central flow path 11, and are directed toward the long axis direction end of the flat tube 1. Accordingly, the other flow paths 12 have the same size as each other, and there is no problem even if the shape and size are changed from the middle, and the number of flow paths is not particularly limited.

  Further, the external appearance of the flat tube 1 is based on an elliptical cross section. In the first embodiment, the dimension of the minor axis direction of the ellipse and the outer diameter of the ellipse is centered on the intersection of the major axis and the minor axis of the ellipse. And a cross-sectional circle in which the tubular portion in the short axis direction (vertical direction in FIG. 2) forming the central channel 11 is expanded outward in the short axis direction. It has an irregular shape with an arc-shaped protrusion 13A. The protruding portion 13A is formed by a short-axis direction tubular portion that forms the central channel 11, and a tubular material corresponding to the volume of the tubular material that extends in the long-axis direction by expanding the tube is stored in advance. One form of the formed tube material storage part 13 is comprised. The tube material reservoir 13 is formed along the longitudinal direction of the flat tube 1, that is, the front-rear direction of the paper surface of FIG. When the tube is inserted and expanded, the arcuate tubular material reservoir portion 13 is elongated mainly in a deformation in which the curvature is reduced by extending in the major axis direction, and the thickness of the elongated portion is suppressed from being reduced. It plays the role which prevents the fall of the proof pressure characteristic of this.

  In FIG. 2, the shape of the outer peripheral surface in the cross section is a shape such as a combination of an ellipse and a circle. However, the basic shape of the ellipse is, for example, an ellipse (race track shape) composed of a semicircle and a straight line. ), The oval shape such as an egg shape that is not symmetrical, and the corners facing each other with a flat rhombus shape are symmetrical with respect to the short axis direction line passing through the intersection of the long axis direction and the short axis direction. For example, it may be replaced with one formed with an arcuate curved surface. In FIG. 2, the corner portion S of the joint portion between the elliptical shape and the arc-shaped protruding portion 13 </ b> A on the outer peripheral surface of the flat tube 1 is shown as an angular shape as a simple intersection of both curves. The corner S may be a smooth corner connected by a gentle curve.

  Further, the outer shape and the flow path shape of the flat tube 1 are the minimum thickness T1 between adjacent refrigerant flow channels formed in the flat tube 1 and the minimum of the outer peripheral surface of the flat tube 1 in the other flow channels 12. The wall thickness, that is, the minimum thickness T2 in the minor axis direction of the other channel 12 is determined to be equal to the minimum thickness T0 in the minor axis direction of the central channel 11 which is the maximum refrigerant channel. Further, the inner peripheral surfaces of the refrigerant flow paths such as the central flow path 11 and the other flow paths 12 are all shown in a smooth shape. However, in order to increase the contact area with the flowing refrigerant, the inner peripheral surface is uneven. Or protrusions may be provided. Further, here, it is configured symmetrically with respect to the long axis or the short axis. Further, the material that can be used as the flat tube is not particularly limited, and copper or its alloys generally used as a heat transfer tube, aluminum or its alloys can be appropriately selected and used. . Further, the flat tube 1 can be easily obtained by extrusion molding or pultrusion which is a conventional general or known processing method.

  Next, a fin tube type heat exchanger (hereinafter sometimes simply referred to as a heat exchanger) will be described with reference to FIGS. After the heat exchanger 3 has inserted the flat tube 1 into the insertion hole 22 of a laminate in which a plurality of thin plate-like fins 2 in which a plurality of insertion holes 22 having fin collars 21 are formed are laminated at a predetermined interval. In the manufacturing method of the fin tube type heat exchanger, which will be described later, the expanded pipe part (not shown) whose cross section of the maximum outer diameter portion is elliptical in the circular central channel 11 of the flat tube 1 has its long axis The outer peripheral surface of the flat tube 1 is inserted and expanded in conformity with the long axis of the flat tube 1, and the outer peripheral surface and fins of the left and right ends of the drawing excluding the protrusion 13A provided at the outer peripheral surface of the flat tube 1, particularly the central portion in the long axis direction. 2 can be obtained by bringing the fin collar 21 formed in the shape 2 into close contact. Note that the shape and the size of the post-expansion central flow path 11Z shown in FIG. 2B are substantially equal to the cross section of the maximum outer diameter portion in the above-described elliptical pipe expansion component. The diameter in the short axis direction at the maximum outer diameter portion of the elliptical pipe expansion component is smaller than the diameter in the short axis direction of the central channel 11 before the pipe expansion, and the diameter in the long axis direction is the central flow before the pipe expansion. The path 11 is formed larger than the diameter in the major axis direction by a predetermined dimension.

  The insertion hole 22 for inserting the flat tube 1 into the fin 2 is formed according to the shape of the outer peripheral surface of the flat tube 1 to be used, and the fin collar 21 is a plate of the fin 2 along the peripheral portion of the insertion hole 22. It is formed to rise in a direction perpendicular to the surface. The shape of the inner peripheral surface of the fin collar 21 and the insertion hole 22 is larger than the outer peripheral surface of the flat tube 1 before being expanded, and the flat tube 1 before being expanded is inserted into the insertion hole 22 of the fin 2. When inserted into the housing, it is a size that does not contact, or a size that does not apply a force to deform the fin shape even if contacted. The insertion hole 22 has an elliptical shape as a basic shape, and an arcuate recess 22a for allowing the protrusion 13A of the flat tube 1 to pass through is formed at the center in the long axis direction. Note that the fin collar 21 is also curved in an arc shape at the arc-shaped recess 22 a so as to follow the shape of the insertion hole 22. Note that the gap between the outer peripheral surface of the flat tube 1 and the inner peripheral surface of the fin collar 21 or the insertion hole 22 in FIG. 2 only schematically shows that there is a gap between them. In addition, the width of the gap in the figure is not directly related to the elemental matters in carrying out the present invention.

  Moreover, the flat tube 1 in the heat exchanger 3 of FIG. 1 has illustrated the state after performing the pipe expansion process, after inserting the flat tube 1 in the insertion hole 22 of the fin 2. As shown in FIG. The shape of the inner peripheral surface of the fin collar 21 formed so as to rise along the edge of the insertion hole 22 is opposed to the outer peripheral surface of the elliptical portion of the entire outer peripheral surface of the flat tube 1 after the expansion. It is determined so that the inner peripheral surface of the fin collar 21 is in surface contact. Although the sectional view of the rising portion of the fin collar 21 from the fin 2 is not shown, the angle of the extending direction of the plate-like fin 2 and the rising direction of the fin collar 21 is 90 degrees or less on the insertion hole 22 side. It only has to be. Thereby, when the flat tube 1 is expanded, the flat tube 1 and the fin collar 21 are not in line contact but in surface contact, and the contact area can be increased.

  In addition, as shown in FIG. 2B, the cross-sectional configuration of the oval-shaped portion in a state where the flat tube 1 inserted through the insertion hole 22 having the fin collar 21 is expanded is centered on the flat tube 1. The fin collar 21 located in the section is in a state in which the flat tube 1 is sandwiched, or the flat tube 1 is in a wedge shape and meshes with the fin collar 21 of the insertion hole 22. The positions of 1 and the insertion holes 22, that is, the fins 2, are fixed and integrated. When the expansion of the flat tube 1 is completed, if the amount of engagement between the flat tube 1 and the fin collar 21 is small, or if there is a portion with a small amount of engagement, for example, using a jig not shown, The positions of the fins 2 and the flat tubes 1 may be determined and fixed by brazing or an adhesive.

  In addition, since the protrusion 13A of the flat tube 1 is extended in the major axis direction by the pipe expansion, the outer dimension in the minor axis direction of the outer peripheral surface becomes smaller according to the amount of extension. Therefore, the gap between the inner peripheral surface of the fin collar 21 and the outer peripheral surface of the protrusion 13A in the arc-shaped recess 22a is formed before the pipe expansion as shown in FIG. 2 (a). In this case, a gap is generated after the tube expansion, but the flat tube 1 and the fin collar 21 are in close contact with each other in the elliptical portion excluding the protruding portion 13A. However, for example, when the flat tube 1 before being expanded is inserted into the insertion hole 22, no force is applied until the outer peripheral surface of the protrusion 13A deforms the shape of the fin 2 itself, and the arc-shaped recess 22a Even after the expansion of the flat tube 1, the protrusion 13 </ b> A whose dimension in the short axis direction is reduced and the inner surface of the fin collar 21 are in contact with the inner peripheral surface of the partial fin collar 21. For example, the deformation amount in the major axis direction and the minor axis direction of the flat tube 1, the size of the fin collar 21 and the insertion hole 22, and the elastic deformation of the fin collar 21 are allowed so that the vicinity of the protruding end portion can maintain the contact state. By optimizing the size and shape of the range, etc., it is possible to maintain the contact state by spring elasticity, and it is possible to further improve the heat exchange efficiency.

  Next, the manufacturing method of the finned tube heat exchanger according to Embodiment 1 will be specifically described. In order to expand the flat tube 1, although not shown, the tube is expanded with a tube expansion billet as a tube expansion component. In this pipe expansion component, the maximum outer diameter portion on the outer peripheral surface that contributes to pipe expansion needs to have a shape in which the long axis direction of the flat tube 1 is expanded with priority over the short axis direction. For example, FIG. May be substantially the same elliptical shape as the post-expansion central flow path 11Z in the flat pipe 1 after the expansion, and is not close to the shape of the post-expansion central flow path 11Z, but the long axis of the post-expansion central flow path 11Z The elliptical shape may be in contact with the direction, and the short axis direction may not be in contact from before the tube expansion to the end of the tube expansion or just before the tube expansion. In addition, there is no problem with an elliptical shape that is formed by an elliptical shape and a straight line that are in contact with the major axis direction of the central flow path 11Z after the tube expansion and are not in contact with the minor axis direction.

  Moreover, the material of this pipe expansion part should just be a material which is not destroyed by buckling etc. with respect to the load when the flat pipe 1 expands. Also, in general, the flat tube 1 is often made of aluminum or copper, and repeated expansion of the flat tube 1 with pipe expansion parts will cause adhesion and wear of aluminum and copper, thus preventing this. Therefore, there is no problem even if the surface is plated.

  When the flat tube 1 is expanded with such a pipe expansion component, a force preferentially expanded in the long axis direction rather than the short axis direction of the flat tube 1 acts, and the central channel 11 of the flat tube 1 is The protruding portion 13A formed by the formed thin tube portion in the short-axis direction is extended in the long-axis direction to form a flat tube 1 after tube expansion as shown in FIG. In this case, the movement in the long axis direction of the tube material along with the extension in the long axis direction is due to plastic deformation in the direction in which the curvature of the protruding portion 13A constituting the tube material reservoir portion 13 is reduced, so that the pipe is expanded. As a result, not only the thickness of the periphery of the central channel 11 centering on the intersection of the long axis and the single axis of the flat tube 1 but also the change in the thickness of the other channels 12 is small, and the tube can be expanded. That is, according to the manufacturing method of Embodiment 1 having such a configuration, even if the flat tube 1 is expanded, it is possible to manufacture a heat exchanger in which the pressure resistance as the flat tube does not decrease.

  As described above, according to the flat tube according to the first embodiment, the tube corresponding to the volume of the tube material that extends in the long axis direction by expanding the tube is formed in the tube portion in the short axis direction forming the central channel 11. As the tube material storage part 13 in which the meat material is stored, the tubular portion in the short axis direction forming the central channel 11 is formed in an arc-shaped cross section formed by expanding outward in the short axis direction. By forming the protruding portion 13A along the longitudinal direction of the tube, the tube material provided in the tube material reservoir 13 is in the long axis direction even if the central channel 11 of the flat tube 1 is expanded. It is suppressed that the thickness of the elongated portion is reduced by being stretched, so that an effect of preventing a decrease in pressure resistance of the flow path can be obtained.

  Further, according to the finned tube heat exchanger 3 according to the first embodiment, the pressure resistance characteristic of the flow path of the flat tube 1 used as the heat transfer tube is maintained without being damaged by the expansion, so that the heat The pressure resistance of the exchanger is improved, and the outer peripheral surface of the elliptical shape including both ends of the flat tube 1 in particular in the long axis direction can be reliably brought into contact with the insertion hole 22 of the fin 2 Therefore, the heat exchange efficiency can be improved. In the heat exchanger having the same performance, the cost can be reduced by reducing the size of the heat exchanger. Further, when the size of the heat exchanger is reduced, the apparatus for manufacturing the heat exchanger can also be reduced, and the apparatus cost can be reduced.

  Moreover, according to the manufacturing method of the fin tube type heat exchanger which concerns on Embodiment 1, when expanding the flat tube 1, the pipe | tube which forms the center part flow path 11 and the other flow path 12 of the flat tube 1 Reduction of the thickness of the meat material is suppressed, and stable tube expansion is possible. Therefore, the pressure resistance of the flat tube 1 is ensured, and the outer peripheral surface of the flat tube 1 can be securely brought into close contact with the fin collar 21, so that a heat exchanger excellent in heat exchange efficiency and reliability can be provided.

Embodiment 2. FIG.
FIG. 3 is a cross-sectional view conceptually illustrating an insertion portion of the flat tube with respect to the fin in the manufacturing method of the flat tube and fin tube heat exchanger according to Embodiment 2 of the present invention. b) shows after tube expansion. In the figure, the flat tube 1A of the second embodiment is provided with an odd number of refrigerant channels arranged in the long axis direction inside as shown in FIG. 3 (a). Among the refrigerant flow paths, the central flow path 11A used for expanding the pipe is elliptical and has a long axis that matches the long axis of the flat tube 1A and a short axis that matches the short axis of the flat tube 1A. . On the other hand, a plurality of other channels 12 that are continuous in the left-right direction of the central channel 11A are substantially the same as those in the first embodiment. The outer shape of the flat tube 1A is based on an elliptical shape, and a circular shape centering on the axis in the minor axis direction passing through the center of the elliptical shape is symmetrically arranged on the upper and lower sides of the figure about the major axis. Two circular shapes are subtracted from an elliptical shape, and the tubular material reservoir 13 has an inner peripheral surface in the minor axis direction of the outer peripheral surface of the minor axis direction tubular portion forming the central channel 11A. It consists of a groove-like portion 13B that is recessed in a circular arc shape.

  Further, the tubular material reservoir portion 13 whose outer peripheral surface side is composed of the groove-shaped portion 13B is not shown in an elliptical shape whose size is larger in both the major axis direction and the minor axis direction than the elliptical shape of the central channel 11A. When the expanded pipe component is disposed so that the major axis direction thereof matches the major axis of the flat tube 1A and is inserted into the central channel 11A to be expanded, the groove-like portion 13B constituting the tubular material reservoir 13 is formed. At the same time that the tube wall is elongated in the major axis direction, and also in the minor axis direction, it is extended by plastic deformation in a direction in which the curvature of the groove-like portion 13B having the outer peripheral surface recessed in a circular arc shape decreases, Since the tubular portion of the groove 13B is moved and supplied mainly in the long axis direction, the thickness of each flow path including the other flow paths 12 accompanying expansion is suppressed, and the pressure resistance of the flow path is reduced. It has a function to prevent deterioration of characteristics.

  Therefore, the shape of the flat tube 1A, the central flow channel 11A for tube expansion, and the shapes of the plurality of other flow channels 12 are the minimum of the groove-like portion 13B forming the central flow channel 11A of the flat tube 1A. The wall thickness T0 is determined so as to be equal to the minimum wall thickness T1 between the other flow paths 12 and the minimum wall thickness T2 with respect to the outer peripheral surface of the flat tube 1A in the other flow paths 12. As shown in FIG. 3A, the cross-sectional area of the central channel 11 </ b> A of the flat tube 1 </ b> A before expanding is formed to be the same as or slightly smaller than the maximum of the other channels 12. It should be noted that the elliptical portion of the external shape of the flat tube 1A can be changed to, for example, an oval shape such as an oval shape or an oval shape, a rhombus shape, etc., and irregularities or protrusions are formed on the inner wall surface of each flow path. The points that may be formed and the intersections of different curves can be formed smoothly are the same as in the first embodiment.

  Moreover, the fin 2 in the heat exchanger 3 of Embodiment 2 is a fin formed so as to rise along the periphery of the insertion hole 22 formed in accordance with the elliptical basic shape of the flat tube 1 </ b> A and the insertion hole 22. It has a collar 21. The shape of the fin collar 21 and the insertion hole 22 is larger than that of the flat tube 1A before being expanded, and when the flat tube 1A before being expanded is inserted into the fin 2, the size is not in contact or contact Even so, the size is such that the force to deform the fin shape is not applied. The insertion hole 22 has an elliptical shape including a portion facing the groove 13B, and is formed so as to rise along the edge of the flat tube 1A and the insertion hole 22 when the flat tube 1A is expanded. The shape is such that the fin collar 21 meshes well in a wedge state.

  When the flat tube 1A as described above is expanded with a tube expansion component having an elliptical cross section, the groove-shaped portion 13B that is recessed from the elliptical shape of the flat tube 1A is extended to the left and right in parallel with the tube axis direction. It becomes the flat tube 1A after tube expansion as shown to 3 (b). The groove-like portion 13B that is recessed from the elliptical shape of the flat tube 1A constitutes the tube material reservoir portion 13, so that the long axis of the flat tube 1A is extended when expanded and expanded. Manufactures a heat exchanger that can be expanded without changing the thickness of the central channel 11A around the intersection of the axis and the single axis, and the pressure resistance of the flat tube does not decrease even if the flat tube 1A is expanded it can.

  As described above, according to the second embodiment, in addition to the effects of the first embodiment, it is not necessary to provide the arc-shaped recess 22a in the insertion hole 22 of the fin 2 in the heat exchanger 3, so the fin collar 21 Since the shape of the fin 2 can be simplified, for example, it becomes easy to form a metal mold, the equipment cost such as the mold can be reduced and the production can be stabilized. Further, by increasing the dimension in the minor axis direction of the pipe expansion part, it becomes easy to bring the outer peripheral surface of the groove-like portion 13B of the flat tube 1A into close contact with the inner peripheral surface of the fin collar 21. Since it becomes easy to enlarge a contact area, a heat exchanger with favorable heat exchange efficiency can be obtained.

Embodiment 3 FIG.
FIG. 4 is a cross-sectional view conceptually illustrating the insertion portion of the flat tube with respect to the fin in the manufacturing method of the flat tube and fin tube heat exchanger according to Embodiment 3 of the present invention. b) shows after tube expansion. FIG. 5 is a main part perspective view conceptually showing a modification of the finned tube heat exchanger according to the third embodiment of the present invention. As shown in FIG. 4 (a), the flat tube 1B before the expansion has an outer peripheral surface based on an elliptical shape, and an odd number of refrigerant channels are arranged in parallel in the major axis direction, and the center in the major axis direction The central channel 11B located at the intersection of the center in the short axis direction is formed in a circular shape. It should be noted that the shape of a plurality of other flow paths 12 that are continuous in the left-right direction of the central flow path 11B, and the point that irregularities and protrusions can be formed on the outer peripheral surface forming the flow path are the same as in the first embodiment. is there.

  In the flat tube 1B according to the third embodiment, the minimum thickness T3 of the tube portion in the short axis direction forming the central channel 11B in the tube material reservoir 13 forms the other channel 12. The minimum thickness T1 between adjacent refrigerant flow paths and the minimum thickness T2 with respect to the outer peripheral surface of the flat tube 1B in each flow path are formed. The cross section of the maximum diameter portion effective for tube expansion is elliptical, the outer diameter in the major axis direction is larger than the dimension in the major axis direction of the central channel 11B, and the outer diameter in the minor axis direction is the central channel 11B. The tube is expanded in the long axis direction by inserting a tube expansion part (not shown) having the same size as the short axis direction. In addition, when the center part flow path 11B is a perfect circle, it cannot be overemphasized that the dimension of the major axis direction and the dimension of a short axis direction of the center part flow path 11B are equal.

  When the pipe material reservoir 13 is expanded in the long axis direction by the pipe expanding component, the short axis direction flesh portion forming the central channel 11B is plastically deformed in the long axis direction, and the tube axis The central channel 11B formed in the central portion in the long axis direction in which the tubular material is stored so that the tubular material corresponding to the volume of the expanded tubular material is supplied as the expansion allowance when being elongated in the direction. The thickness increasing portion 13C is a cross-sectional portion including the minimum thickness T3 in the minor axis direction. In addition, the oval appearance of the flat tube 1B can be changed to, for example, an oval shape such as an oval shape or an oval shape, a rhombus shape, etc., and irregularities or protrusions are formed on the inner wall surface of each flow path. The other points are the same as in the first embodiment.

  Moreover, the fin 2 in the heat exchanger 3 of Embodiment 3 has the fin collar 21 formed so that it may stand along the insertion hole 22 formed according to the shape of the flat tube 1B, and the insertion hole 22 periphery. ing. The shape of the fin collar 21 and the insertion hole 22 is larger than that of the flat tube 1B before being expanded. When the flat tube 1B before being expanded is inserted into the fin 2, the size is not in contact or contact Even so, the size is such that the force to deform the fin shape is not applied. The insertion hole 22 has a shape such that when the flat tube 1B is expanded, the flat tube 1B and the fin collar 21 are engaged in a wedge state.

  When the pipe expansion part (not shown) is inserted into the central channel 11B to expand the tube, the circular central channel 11B is expanded into an elliptical channel as shown in FIG. 4B. In addition, the outer peripheral surface of the flat tube 1 </ b> B, in particular, the outer peripheral surface of the portion excluding the central portion in the major axis direction is in close contact with the inner peripheral surface of the fin collar 21. In addition, also about the center part of a major axis direction, making the dimension of the minor axis direction of a pipe expansion part larger than the dimension of the minor axis direction of the flat tube 1B, or making the inclination to the center direction of the fin collar 21 large. Therefore, it is easy to improve the adhesion. As the pipe is expanded, the minimum thickness T3 in the short axis direction forming the central channel 11B decreases, but is thicker than the minimum thicknesses T1 and T2 of the other channels 12 in the initial state. Therefore, since the tube material is covered by the tube material reservoir 13 formed of the wall thickness increasing portion 13C without lowering the pressure resistance, the wall thickness of all the channel portions accompanying the extension of the central channel 11B in the major axis direction. Is suppressed, and the pressure resistance characteristics of the flow path are prevented from being lowered.

  In the modification of FIG. 5, the flat tube 1B shown in FIG. 4 is changed to a flat tube 1C having an elliptical cross section, and in accordance with the change, the cross-sectional dimension of the flat tube 1C before expansion is longer. The heat exchanger 3 is configured using the fins 2 provided with circular insertion holes 22 and fin collars 21 (not shown). As in the case of the elliptical flat tube 1B, the flat tube 1C is provided with a flow path for allowing an odd number of refrigerants to flow in the major axis direction having an oval cross section. The central channel has a circular shape before pipe expansion, and is formed with a thickened portion having the same function as the thickened portion 13B of the tubular material reservoir 13 shown in FIG. The cross section of the maximum diameter portion is elliptical, the outer diameter in the major axis direction is larger than the dimension in the major axis direction of the central channel, and the outer diameter in the minor axis direction is the minor axis dimension of the central channel. It is configured to be expanded mainly in the long axis direction by inserting a pipe expansion part (not shown) of the same level as the above. In the case of the elliptical flat tube 1 </ b> C, the direction extended by the tube expansion is mainly the long axis direction, and the shape of the insertion hole 22 is accordingly formed.

  As shown in FIG. 5, the heat exchanger 3 in the modified example rises along a plurality of flat tubes 1 </ b> C along an insertion hole 22 formed in accordance with the shape of the flat tube 1 </ b> C and a peripheral portion of the insertion hole 22. A plurality of thin plate-like fins 2 having fin collars 21 (not shown) formed as described above are arranged. It is known that the interval between the plurality of fins 2 greatly contributes to performance. In order to keep the interval between the plurality of fins 2, slit-shaped protrusions protruding in the depth direction of the figure formed by press molding such as cutting and raising between adjacent flat tubes 1 </ b> C on the plate surface of the fins 2. 23 is provided.

  Moreover, the convex part 23 is required in order to improve the heat exchange property of the fin 2. However, if it is the convex part 23, there will be no restriction | limiting in a shape. Moreover, when the space | interval of the several fin 2 can be maintained, there is no problem even if there is no convex part 23 or it is a convex part less than the space | interval of the several fin 2. FIG. For example, the plurality of fins 2 may be fixed with a jig or the like (not shown) and fixed to the plurality of flat tubes 1C and the fins 2. In FIG. 5, the flat tube 1 </ b> C is formed by bending one flat tube into a U shape or a hairpin shape, but the flat tube 1 </ b> C may be a straight straight tube. In that case, before and after assembling a plurality of flat tubes and flat fins 2, U-shaped pipes are attached to the ends of straight tubular flat tubes by brazing, etc., and formed into a U-shape as shown in the figure it can.

  As described above, in the flat tube 1B or the flat tube 1C according to the third embodiment, the tube wall material reservoir 13 has the minimum thickness T3 of the tube portion in the short axis direction in which the central channel 11B is formed. The minimum thickness T2 of the tubular portion in the short axis direction forming the other flow path 12 and the minimum thickness T1 in the long axis direction of the flow paths adjacent to each other in the long axis direction are made larger. It is formed by the thickened portion 13C.

  When such a flat tube 1B or flat tube 1C is expanded, the peripheral portion of the central channel 11B is extended to become a flat tube after the expansion as shown in FIG. Although the peripheral portion of the central channel 11B is extended and expanded, the minimum thickness T3 of the central channel 11B is reduced, but the other channel 12 is formed in the initial state in the short axis direction. The pressure resistance of the flat tube does not decrease as much as it is thicker than any of the minimum wall thickness T2 of the tube wall portion and the minimum wall thickness T1 of the flow paths adjacent to each other in the long axis direction. A heat exchanger can be manufactured. Moreover, since the shape of the flat tube 1B, the flat tube 1C, and the fin 2 can be simplified, the further effect that reduction of equipment costs, such as a metal mold | die, and production stabilization are obtained is acquired.

Embodiment 4 FIG.
FIG. 6 is a perspective view conceptually showing a main part of a flat tube and a finned tube heat exchanger using the flat tube according to Embodiment 4 of the present invention. In the fourth embodiment, for example, after the expansion of the outer peripheral surface of the flat tube 1 and the inner peripheral surface of the fin collar 21 in the heat exchanger 3 using the flat tube 1 similar to the first embodiment shown in FIG. Are connected to each other by a brazing, an adhesive, an adhesive mixed with metal powder, or the like, which has a lower thermal resistance than a simple contact between metal surfaces due to the elastic force of the fin collar 21, or By connecting, the thermal resistance between the flat tube 1 and the fin collar 21 is lowered.

  In the figure, at the boundary between the outer peripheral surface of the flat tube 1 after the pipe expansion and the upper end of the fin collar 21, good thermal conductivity such as brazing, adhesive, or metal powder, as conceptually indicated by a thick line. There is provided a joining portion 24 joined by an adhesive mixed with various powders. Note that the brazing material, the adhesive, and the like used for the joint portion 24 are permeated not only to the boundary portion described above but also to the outer peripheral surface of the flat tube 1 and the inner peripheral surface of the fin collar 21. Moreover, it penetrate | invades also into the clearance gap between the outer peripheral surface of 13 A of protrusion parts in the outer peripheral surface of the flat tube 1 as shown in FIG.2 (b), and the inner peripheral surface of the fin collar 21, and heat conduction between both is carried out. Has contributed. In addition, the flat tube 1 is not limited to the illustrated thing, For example, you may replace with the thing of FIGS.

  As described above, according to the fourth embodiment, even if the flat tube 1 is expanded, it is possible to manufacture a heat exchanger in which the pressure resistance as the flat tube does not decrease, and heat for assembling the fins 2 by expanding the flat tube 1. The heat exchange performance of the exchanger is improved. Therefore, even if the size is the same, the heat exchange performance of the heat exchanger is improved, or in the heat exchanger having the same performance, the cost can be reduced by reducing the size of the heat exchanger. Further, when the size of the heat exchanger is reduced, the apparatus for manufacturing the heat exchanger can also be reduced, and the apparatus cost can be reduced.

  It should be noted that the present invention can be freely combined with each other within the scope of the invention, and each embodiment can be appropriately modified or omitted.

1, 1A, 1B, 1C flat tube, 11, 11A, 11B central channel,
11Z Central channel after pipe expansion, 12 other channels, 13 tube material reservoir, 13A ridge,
13B Groove-shaped portion, 13C Thickness increasing portion, 2 fin, 21 fin collar,
22 insertion hole, 22a arcuate recess, 23 convex part, 24 joint part, 3 heat exchanger,
S corner, T0 minimum thickness (short axis direction of the central channel 11),
T1 minimum wall thickness (between refrigerant flow paths), T2 minimum wall thickness (short axis direction of other flow paths 12),
T3 Minimum wall thickness (short axis direction of the central channel 11B).

Claims (9)

  Fin tube heat exchange that allows tube expansion by inserting a tube expansion component into a central channel located in the center of a plurality of channels that have a flat cross section and are arranged in the longitudinal direction. In a flat tube for dexterity, a tubular material in which a tubular material corresponding to the volume of the tubular material extending in the major axis direction by the expansion is stored in a tubular portion in the short axis direction forming the central channel. A flat tube of a finned tube heat exchanger, characterized in that a reservoir is provided along the longitudinal direction of the tube.   The tubular material reservoir portion is composed of a protruding portion having an arcuate cross section formed by expanding a tubular portion in the short axis direction forming the central channel in the outward direction in the short axis direction. The flat tube of the finned-tube heat exchanger according to claim 1.   The tubular material reservoir portion is formed by denting a tubular portion in the short axis direction forming the central channel and reducing the cross-sectional area of the central channel in the inner direction in the short axis direction. 2. The flat tube of a finned tube heat exchanger according to claim 1, wherein the outer peripheral surface shape in which the tube material is stored is a groove-shaped portion having an arcuate cross section.   The tubular material reservoir has a thickness of a tubular portion in the short axis direction that forms the central channel, and a minimum thickness of a tubular portion in the minor axis direction that forms another flow path. 2. The finned tube heat exchanger according to claim 1, wherein the finned tube heat exchanger comprises a thickness increasing portion formed larger than both the thickness and the minimum thickness in the major axis direction between the channels adjacent to each other in the major axis direction. Flat tube.   The flat tube of the finned tube heat exchanger according to any one of claims 1 to 4, wherein the cross section has an elliptical shape, a rhombus shape, or an oval shape.   The flat tube according to any one of claims 1 to 5 is used as a heat transfer tube disposed so as to penetrate a plurality of fins and provided with a flow path through which a refrigerant flows. Fin tube heat exchanger.   The fin tube heat exchanger according to claim 6, wherein the flat tube and a fin collar formed in the insertion hole of the fin are joined by a brazing material or an adhesive.   As a heat transfer tube for a finned tube heat exchanger, a short axis direction that forms a central channel located in the center of a plurality of channels that have a flat cross section and are arranged side by side in the long axis direction A flat tube in which a tube material reservoir portion in which a tube material corresponding to the volume of the tube material extending in the long axis direction is expanded is provided along the longitudinal direction of the tube is used. When the tube is inserted through the insertion hole of the fin and expanded, the expanded part in which the cross section of the maximum diameter portion is elliptical and the long axis direction of the tube matches the long axis direction of the flat tube is inserted into the central channel. A method of manufacturing a finned tube heat exchanger.   The tubular material reservoir portion is composed of a protruding portion having an arcuate cross section in which a tubular portion in the short axis direction forming the central channel is expanded outward in the short axis direction, or The outer peripheral surface of the tube portion in the short axis direction forming the central channel is recessed in a circular arc shape in the inner direction in the short axis direction, and the cross sectional area of the central channel is reduced. Thickness of a tube-shaped portion in which the meat material is accumulated, or the thickness of the tube portion in the short axis direction forming the central channel, the short axis direction forming another channel 9. The tube wall portion of claim 8, wherein the tube wall portion is formed larger than both the minimum thickness in the major axis direction of the flow paths adjacent to each other in the major axis direction. Manufacturing method of finned tube heat exchanger.

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