JP2013252560A - Method for bending heat exchanger - Google Patents

Abstract

A bending method that suppresses the occurrence of buckling that occurs during bending of a heat exchanger is provided.
In the bending method of the outdoor heat exchanger 7, only one gripping part of the heat exchanger is gripped, and the bending part is controlled by controlling the posture of the gripping part so that the gripping part draws a predetermined locus. Bending without using. At that time, the contact position of the free part of the heat exchanger that is not gripped with the guide part 121 is determined by the reaction force generated during bending. Therefore, no restraining force is generated in the free part that is not gripped, and the occurrence of buckling in the heat exchanger 7 during bending can be avoided.
[Selection] Figure 5

Description

  The present invention relates to a heat exchanger bending method, more specifically, at least a part of a flat plate-like heat exchanger having a large number of heat transfer tubes and heat transfer fins positioned between adjacent heat transfer tubes. The present invention relates to a bending method for a heat exchanger that performs bending processing.

  In order to be able to arrange the heat exchanger compactly inside a casing of a predetermined size such as an outdoor unit of an air conditioner, it is necessary to perform a bending process for bending the heat exchanger on the flat plate into an L shape or a U shape. . As a method for bending a heat exchanger, there is a method shown in Patent Document 1 (Japanese Patent Laid-Open No. 6-347186). In this heat exchanger bending method, bending is performed by pressing a flat heat exchanger composed of heat transfer fins and heat transfer tubes around a curved surface of a bending die.

  However, in the method of bending a heat exchanger disclosed in Patent Document 1, deformation and bending occur in the fin located at a portion in contact with the bending die when the finned heat exchanger is bent.

Further, when the bending radius is changed at the time of design change, it is necessary to recreate the bending mold, which consumes a great deal of time and money.
Furthermore, in order to avoid reworking of the bending mold, the design is often made on the assumption that the bending radius dimension of the heat exchanger is not changed, and the dimension of the existing bending mold becomes a design constraint. Yes.

  In order to solve the problems at the time of bending using a bending die, Patent Document 2 (Japanese Patent Laid-Open No. 7-47427) grasps two or more parts of a workpiece without using a bending die and rotates one. A bending apparatus for a cross fin type heat exchanger that performs bending by rotating around an axis is disclosed. When bending a heat exchanger of a type in which corrugated fins and flat refrigerant tubes are laminated by this method, buckling occurs between the two gripped parts gripped in the final bending stage of the bending process, In some cases, the target shape cannot be bent.

  In particular, in a microchannel heat exchanger in which heat transfer fins and corrugated fins having a rectangular cross-sectional shape and flat multi-hole tubes are stacked, a large deformation may occur in a bent portion.

  In view of the problems of the prior art, the present invention can suppress the occurrence of deformation and bending of heat transfer fins during bending of a cross fin type heat exchanger composed of heat transfer fins and heat transfer tubes, A heat exchanger that can suppress the occurrence of buckling that occurs during bending of a microchannel heat exchanger in which a corrugated fin has a rectangular cross-sectional shape and a flat multi-hole tube, and its bending Provide a processing method.

  In order to achieve the above object, the present invention employs the following technical scheme.

  A heat exchanger bending method, the heat exchanger having a plurality of heat transfer tubes and heat transfer fins positioned between adjacent heat transfer tubes, and the processing steps are as follows. .

1st step: The grip part which is the adjacent part of the 1st end of the bending object part of the said heat exchanger is gripped,
Second step: Select a movement trajectory of the center of the grip portion based on the bending position and the curvature of curvature,
Third step: The posture is changed while moving the gripping part so as to draw the movement trajectory, and the free part which is the second end of the bending target part is in contact with one guide surface in the moving process. Like that.

  Here, the grip portion is an adjacent portion of the first end of the bending target portion. The free part is the second end of the part to be bent. The contact surface between the free portion and the guide portion is a surface on the opposite side to the surface that is curved when the heat exchanger is bent.

  In this heat exchanger bending method, only one portion of the heat exchanger is gripped, and the gripping part is bent without using a bending die by controlling the posture of the gripping part so that the predetermined part is drawn as a locus. . The contact position of the free part of the heat exchanger, which is not gripped, with the guide part is determined by the reaction force generated during bending.

  As a result, in this bending method, since there is no bending die, the fin does not receive a force from the bending die at the time of bending, and fin collapse can be avoided. In addition, even when the design of the bending radius is changed, the bending radius can be changed only by inputting a numerical value into the program, and it is not necessary to manufacture an expensive bending die having a long delivery time.

  In addition, the position of the free part of the heat exchanger that holds only one part of the heat exchanger and is not gripped is determined by the reaction force generated during bending, so the heat exchanger Excessive restraint force is not generated in portions other than the gripping portion, and occurrence of buckling during bending can be avoided.

  The bending method is completed using a bending device, and the bending device includes a gripping device, a driving device that drives the gripping device, and a control unit that controls movement of the gripping measure.

  The bending apparatus includes a guide portion, and the guide surface is a contact surface between the guide portion and the free portion.

  In the third step, when the grip portion moves, the contact surface of the free portion is slidable with respect to the guide portion.

  In this bending method, the contact surface of the free part is slidable with respect to the guide part when the gripping part moves along a predetermined movement locus and performs bending. Therefore, the position of the free part of the heat exchanger is determined by the reaction force generated during bending, and the contact position with the guide is determined. Can be avoided.

になるように選択されている。 The coordinates of the movement locus of the bending center of the gripping part in the second step are:

Have been selected to be.

  Of these, Co is the center of the gripping part, θi is an angle θi (defined by θi. = Ωt) formed by the gripping part and the X axis, Ci is the center of the gripping part when the bending process proceeds, and ρ is θi The radius of curvature when the bending process is advanced, ω is the angular velocity, t is the time, and W is the width of the gripping part (the width for gripping the heat exchanger).

  In this bending method, when the bending position and the bending curvature of the heat exchanger are determined, the coordinates of the movement locus of the bending center of the gripping part can be calculated according to Equation (1). Therefore, even when the design of the bending radius is changed, the bending radius can be changed only by inputting a numerical value into the program, and it is not necessary to manufacture an expensive bending die having a long delivery time.

  The heat exchanger processed by the heat exchanger bending method has a plurality of heat transfer tubes and heat transfer fins positioned between adjacent heat transfer tubes, and crosses the refrigerant flowing in the heat transfer tubes and the heat transfer tubes. Heat exchange with the air flow is performed, and the heat transfer tube is a flat multi-hole tube in which a plurality of flow path holes arranged in the width direction are formed.

  When a heat exchanger that has been bent is used as a heat exchanger that exchanges heat between the refrigerant and the air flow, the ventilation resistance of the air flow in the bent portion of the heat exchanger is There is a tendency to be larger than the unprocessed portion. On the other hand, in this heat exchanger bending method, even if the heat exchanger performs heat exchange between the refrigerant flowing in the heat transfer tube and the air flow across the heat transfer tube, the heat transfer fin is deformed. Can be suppressed.

Moreover, in the heat exchanger which employ | adopted the flat tube or the flat multi-hole tube as a heat exchanger tube, compared with the heat exchanger which employ | adopted the circular tube as a heat exchanger tube, the problem that a heat exchanger fin deform | transforms at the time of a bending process tends to arise.

  On the other hand, in this heat exchanger bending method, even if the heat exchanger employs a flat tube or a flat multi-hole tube as the heat transfer tube, deformation of the heat transfer fins can be suppressed.

The heat transfer fin of the heat exchanger processed by the bending method of the heat exchanger is a corrugated fin composed of corrugated fins bent in a waveform along the longitudinal direction of the heat transfer tube, and the heat exchanger is a corrugated fin And a heat exchanger manufactured by laminating flat multi-hole tubes.

  In the cross section perpendicular to the longitudinal direction of the corrugated fin of the heat exchanger processed by the bending method of the heat exchanger, the cross-sectional shape of the corrugated fin is rectangular, and the edges of the corrugated fins adjacent in the vertical direction are in contact with each other. Has been.

In a heat exchanger that employs a flat tube or a flat multi-hole tube as a heat transfer tube, the load applied to the heat transfer fins tends to increase during bending compared to a heat exchanger that employs a circular tube as the heat transfer tube. In addition, when the heat transfer fin is a corrugated fin formed of a wave fin bent in a waveform along the longitudinal direction of the heat transfer tube, particularly when the cross-sectional shape of the wave fin is a rectangle, the heat transfer fin is buckled. Prone to occur.

  On the other hand, in this heat exchanger bending method, even a heat exchanger that employs a flat tube or a flat multi-hole tube as a heat transfer tube and a corrugated fin as a heat transfer fin, Occurrence of bending and buckling during bending can be suppressed.

The heat exchanger processed by the bending method of the heat exchanger has flat heat transfer fins in which a plurality of flat multi-hole tubes are arranged and a plurality of notches that match the cross-sectional shape of the flat multi-hole tubes are formed. A plurality of rows are inserted from a direction perpendicular to the arrangement direction of the multi-hole tube.
Here, a louver-shaped cut may be formed on the surface of the heat transfer fin in a direction perpendicular to the insertion direction.

  In a heat exchanger that employs a flat tube or a flat multi-hole tube as a heat transfer tube, the load applied to the heat transfer fins tends to increase during bending compared to a heat exchanger that employs a circular tube as the heat transfer tube. In addition, in the case of a heat exchanger configured by inserting a plurality of rows of heat transfer fins formed with a plurality of cutout portions that match the cross-sectional shape of the flat multi-hole tube from the direction perpendicular to the arrangement direction of the flat multi-hole tube, When a louver-like cut is formed on the surface of the heat transfer fin in a direction perpendicular to the insertion direction, the heat transfer fin is likely to buckle.

  On the other hand, with this heat exchanger bending method, it is possible to suppress the bending of the heat transfer fins and the occurrence of buckling during bending.

  The thickness of the heat transfer fin of the heat exchanger processed by the bending method of the heat exchanger is 100 μm or less, and the heat exchanger processing method is such that the heat transfer fin is brazed to the heat transfer tube.

  Here, when the heat transfer fins are brazed to the heat transfer tubes and the thickness of the heat transfer fins is 100 μm or less, the heat effect during brazing and the brazing material on the surface of the heat transfer fins flow to another place. Due to the thinning caused, the strength of the heat transfer fin is lowered, and the protruding portion of the heat transfer fin is easily bent. On the other hand, in this heat exchanger bending method, even if the heat transfer fin with a thin wall thickness is brazed to the heat transfer tube, the protruding portion of the heat transfer fin is prevented from being bent. be able to.

  In the bending method according to the present application, since there is no bending die, the fin does not receive a force from the bending die at the time of bending, and the fin collapse can be avoided. In addition, even when the design of the bending radius is changed, the bending radius can be changed only by inputting a numerical value into the program, and it is not necessary to manufacture an expensive bending die having a long delivery time.

  In addition, the position of the free part of the heat exchanger that holds only one part of the heat exchanger and is not gripped is determined by the reaction force generated during bending, so the heat exchanger Excessive restraint force is not generated in portions other than the gripping portion, and occurrence of buckling during bending can be avoided.

It is a figure which shows the internal structure of the outdoor unit of the outdoor heat exchanger concerning one Embodiment of this invention. The enlarged view of the II section of FIG. It is an expansion perspective view of the III section of FIG. It is a figure which shows the preparation state of the bending process of a heat exchanger. It is a figure which shows the bending process state of a heat exchanger. It is a figure which shows the movement locus | trajectory of the holding part at the time of the bending process of a heat exchanger. It is an image figure of a corrugated heat-transfer fin with a rectangular cross section. It is a partial expansion perspective view of the heat exchanger which has a normal corrugated fin. It is an image figure of the heat exchanger which has an insertion fin. It is sectional drawing of an insertion fin.

  A bending method for a heat exchanger and a heat exchanger according to the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view showing a schematic internal structure of an outdoor unit 1 having an outdoor heat exchanger 7 in which a heat exchanger bending method and a heat exchanger according to an embodiment of the present invention are employed. The outdoor unit 1 constitutes an air conditioner that performs air conditioning by a vapor compression refrigeration cycle. The outdoor unit 1 is connected to an indoor unit (not shown) via the refrigerant communication pipes 2 and 3. In the following description, the front side in FIG. 1 is referred to as “front surface”, the back side in FIG. 1 is referred to as “rear surface”, the left side in FIG. 1 is referred to as “left side”, and the right side in FIG. 1 is the “top surface”, and the lower side of FIG. 1 is the “bottom surface”.

  The indoor unit 2 mainly includes a substantially rectangular parallelepiped box-shaped unit casing 4, a compressor 6, an outdoor heat exchanger 7, and an outdoor fan 8. In addition to the above, the indoor unit 2 accommodates various devices, valves, refrigerant pipes, etc., but the description thereof is omitted here.

  The unit casing 4 mainly includes a bottom plate 41, a top plate 42 (illustrated by a two-dot chain line), a front plate 43 (illustrated by a two-dot chain line), a side plate 44 (illustrated by a two-dot chain line), a partition plate 45, have.

  The bottom plate 41 is a horizontally long, substantially rectangular plate-like member that constitutes the bottom surface portion of the unit casing 4. The peripheral edge of the bottom plate 41 is bent upward. On the outer surface of the bottom plate 41, two fixed legs 5 fixed to the field installation surface are provided. The fixed leg 5 extends from the front side of the unit casing 4 toward the rear side.

  The top plate 42 is a horizontally long and substantially rectangular plate-like member that constitutes the top surface portion of the unit casing 4.

  The front plate 43 is a plate-like member that mainly forms the front portion of the unit casing 4 and the front portion of the right side surface. The lower part of the front plate 43 is fixed to the bottom plate 41 with screws or the like. The front plate 43 is formed with an air outlet 43a. The blower outlet 43a is an opening for blowing outdoor air taken into the unit casing 4 through suction ports (not shown) formed on the back surface and the left side surface of the unit casing 4 (arrows A to A indicating airflow). See C).

  The side plate 44 is a plate-like member that mainly constitutes the rear portion and the right back portion of the right side surface of the unit casing 4. The lower part of the side plate 44 is fixed to the bottom plate 42 with screws or the like.

  The partition plate 45 is a plate-like member disposed on the bottom plate 41. The partition plate 45 extends vertically. The partition plate 45 is disposed so as to partition the internal space of the unit casing 4 into two left and right spaces (that is, the fan chamber S1 and the machine chamber S2). The lower part of the partition plate 45 is fixed to the bottom plate 41 with screws or the like.

  Thus, the internal space of the unit casing 4 is divided into the blower chamber S1 and the machine chamber S2 by the partition plate 45. The blower chamber S <b> 1 is a space surrounded by the bottom plate 41, the top plate 42, the front plate 43, and the partition plate 45. The machine room S <b> 2 is a space surrounded by the bottom plate 41, the top plate 42, the front plate 43, the side plate 44, and the partition plate 45. In the blower room S1, an outdoor heat exchanger 7 and an outdoor fan 8 are mainly disposed. A compressor 6 is mainly disposed in the machine room S2.

  The compressor 6 is a compressor for compressing a low-pressure refrigerant in the refrigeration cycle until it becomes a high-pressure refrigerant. The compressor 6 is an approximately vertical cylindrical hermetic compressor. The compressor 6 is disposed at the approximate center in plan view in the machine room S2.

  The outdoor heat exchanger 7 functions as a refrigerant radiator that uses outdoor air as a heat source during cooling, and functions as a refrigerant evaporator that uses outdoor air as a heat source during heating. The outdoor heat exchanger 7 is a fin tube type heat exchanger constituted by a plurality of heat transfer tubes 11 and a plurality of heat transfer fins 12. The outdoor heat exchanger 7 is bent so as to form a substantially L shape in plan view. The outdoor heat exchanger 7 is disposed in the blower chamber S <b> 2 so as to follow the left side surface and the back surface of the unit casing 4 and to surround the left side surface and the back surface side of the blower fan 8. The detailed configuration and manufacturing method of the outdoor heat exchanger 7 will be described later.

  The outdoor fan 8 takes air into the blower chamber S <b> 1 through suction ports (not shown) formed on the left side surface and the back surface of the unit casing 4, passes the outdoor heat exchanger 7, and then the front surface of the unit casing 4. It is a ventilation fan which functions so that it may blow off from the blower outlet 43a formed in this. Here, the outdoor fan 8 is a propeller fan, and is disposed downstream of the outdoor heat exchanger 7 in the blower chamber S1.

  Next, the detailed structure of the outdoor heat exchanger 7 is demonstrated using FIG.2 and FIG.3. Here, FIG. 2 is an enlarged view of the II part of FIG. 1, and FIG. 3 is an enlarged perspective view of the III part of FIG.

  The outdoor heat exchanger 7 mainly includes a plurality of stacked flat heat transfer tubes 11, heat transfer fins 21 disposed between the flat tubes 11, and header tubes 48 and 49.

The flat tube 11 has a direction perpendicular to the longitudinal direction (vertical direction) of the headers 48 and 49 (specifically,
It is a plate-like aluminum or aluminum alloy tube member extending in the horizontal direction. The several flat tube 11 consists of a flat tube which has the wide plane part 12 in the direction orthogonal to the longitudinal direction. The heat transfer tube 11 faces the width direction of the flat surface portion 12 (in the direction of arrows A and B in FIG. 1 and in the direction of arrow E in FIG. 2) between the vertical directions with the flat surface portion 12 facing in the vertical direction. A plurality of ventilation spaces are arranged with outdoor air flow.

  The planar portion 12 is formed with a plurality of flow passage holes 13 arranged in the width direction so as to penetrate the planar portion 12 in the longitudinal direction. The refrigerant flows through each flow path hole 13. The heat transfer tube 11 is made of a metal material such as aluminum and is manufactured by extrusion molding or the like. Thus, the flat multi-hole tube in which the several flow-path hole 13 (refer FIG. 3) was formed is employ | adopted as the heat exchanger tube 11 here, and the heat transfer rate by the side of a refrigerant | coolant is improving.

  The heat transfer fins 21 are made of aluminum or an aluminum alloy. Specifically, the heat transfer fin 21 is configured by bending a plate-shaped material having a width direction dimension larger than the width direction dimension of the flat portion 12 of the heat transfer tube 11 into a waveform along the longitudinal direction of the heat transfer tube 11. Corrugated fin. Here, when the width direction dimension of the plane part 21 is W1 and the width direction dimension of the heat transfer fin 21 is W2, the relation of the width direction dimension W1 of the plane part 12 <the width direction dimension W2 of the heat transfer fin 21 is established. Yes. The heat transfer fin 21 is made of a metal material such as aluminum. The heat transfer fin 21 has a fin body portion 22 and a fin edge portion 23.

  The fin body portion 22 is a portion disposed in the ventilation space between the upper and lower directions of the flat surface portion 12, and an upper end 24 and a lower end 25 are formed by bending a plate-like material into a waveform along the longitudinal direction of the heat transfer tube 11. ing. The upper end 24 is joined to the lower surface of the flat portion 12 by brazing. The lower end 25 is joined to the upper surface of the flat portion 12 by brazing. In addition, in order to improve heat exchange efficiency, the fin main body portion 22 is formed with a plurality of main body side cut-up portions 26 by cutting up the central portion of the fin main body portion 22 in the vertical direction. Here, the main body side cut and raised portion 26 is cut and raised in a louver shape. And the main body side cut-and-raised part 26 is formed so that the inclination direction with respect to the outdoor air flow is reversed between the upstream portion and the downstream portion of the outdoor air flow.

  The fin edge portion 23 is a portion in which a part of the heat transfer fin 21 protrudes in a direction orthogonal to the longitudinal direction of the heat transfer tube 11. More specifically, the fin edge part 23 is a part which protrudes toward the width direction outer side (here both width direction outer sides) of the heat exchanger tube 11 from each ventilation space. The fin edge portion 23 is formed with an upper end 27 and a lower end 28. The upper end 27 and the lower end 28 are provided with cuts in the vicinity of the fold lines for forming the upper end 24 and the lower end 25, thereby bending the plate material into a waveform along the longitudinal direction of the heat transfer tube 11. When the lower end 25 is formed, it is a part that is cut and raised in the vertical direction. Here, the upper end 27 and the lower end 28 are on the downstream side of the outdoor air flow in the fin edge portions 23 formed on both sides in the width direction of the heat transfer tube 11 (in FIG. 1, the outdoor fan 8 side, in FIG. It is formed only on the fin edge 23 located on the (E side). For this reason, the fin edge portions 23 adjacent in the vertical direction are in contact with or close to each other via the upper end 27 and the lower end 28. Here, the upper end 27 and the lower end 28 are cut and raised in a substantially rectangular shape because the cut is provided in parallel to the width direction of the heat transfer tube 11, but the cut is formed in the width direction of the heat transfer tube 11. May be cut up and formed into a substantially triangular shape or a substantially trapezoidal shape. Further, in order to improve the heat exchange efficiency, the fin edge portion 23 is formed with a plurality of edge side raised portions 29a and 29b by cutting the central portion of the fin edge portion 23 in the vertical direction. The edge cut-and-raised portion 29 a located on the upstream side of the outdoor air flow is formed to have the same vertical width as that of the main body-side cut and raised portion 26. On the other hand, the edge cut-and-raised portion 29b located on the downstream side of the outdoor air flow is formed to have a shorter vertical width than the body-side cut and raised portion 26. Here, the edge cut and raised portions 29a and 29b are cut and raised in a louver shape. The edge cut-and-raised portions 29a and 29b are formed so that the inclination direction with respect to the outdoor air flow is reversed between the upstream portion and the downstream portion of the outdoor air flow. As described above, since the vertical width of the edge cut-and-raised portion 29b is shorter than that of the main body-side cut and raised portion 26, the strength of the fin edge portion 23 is prevented from being lowered.

  In the outdoor heat exchanger 7 having the above-described configuration, when functioning as a refrigerant radiator during cooling, the refrigerant that flows through the heat transfer tube 11 and the cooling source that flows through the ventilation space so as to cross the heat transfer tube 11 are used. The outdoor air exchanges heat with the heat transfer fins 21 and the heat transfer tubes 11. Then, heat dissipation of the refrigerant is performed. Further, when the outdoor heat exchanger 7 functions as a refrigerant evaporator, the refrigerant flowing in the heat transfer tube 11 and the outdoor air as a heating source flowing in the ventilation space so as to cross the heat transfer tube 11 are heat transfer fins 21. And heat exchange is performed via the heat transfer tube 11. Then, the refrigerant is evaporated. At this time, dew condensation water is generated on the surface of the heat transfer fin 21, but the fin edge 23 is formed on the downstream side of the outdoor air flow of the outdoor heat exchanger 7. Condensed water can flow downward. In particular, as described above, the fin edge portion 23 has the upper end 27 and the lower end 28, and the fin edge portions 23 adjacent to each other in the vertical direction are in contact with each other or close to each other. doing.

  7 (a) to 7 (d) are cross-sectional image diagrams of the heat transfer fins of the outdoor heat exchanger shown in FIG. A corrugated fin in which the cross section of the corrugated fin is rectangular and the fin edges adjacent in the vertical direction are in contact with each other or close to each other is also referred to as a bridge fin.

  The bridge fin 321 in FIG. 7A has a shape in which the angle between the upper end 324 and the lower end 325 formed by bending into a corrugated shape and the fin body 322 forms a right angle.

  The bridge fin 421 shown in FIG. 7B has a shape in which the angle between the upper end 424 and the lower end 425 formed by corrugation and the fin body 422 is a right angle, and the intersection 426 is chamfered. is there.

  The bridge fin 521 in FIG. 7C has a shape in which the angle between the upper end 524 and the lower end 525 formed by bending into a corrugated shape and the fin body 522 forms an obtuse angle.

  The bridge fin 621 in FIG. 7D has a shape in which the angle between the upper end 624 and the lower end 625 formed by bending into a corrugated shape and the fin body 622 forms an obtuse angle, and the intersection 626 is chamfered. is there.

  Next, the manufacturing method of the outdoor heat exchanger 7 is demonstrated based on FIGS. Here, FIG. 4 shows a preparation state for bending the outdoor heat exchanger 7. FIG. 5 is a diagram showing a bending state of the outdoor heat exchanger 7. FIG. 6 is a diagram illustrating a movement trajectory of the grip portion during bending of the heat exchanger.

  First, a flat plate-shaped outdoor heat exchanger 7 that is not bent is prepared. Here, as shown in FIG. 2, the flat plate-shaped outdoor heat exchanger 7 includes a plurality of straight tubular heat transfer tubes 11 with the planar portions 12 facing each other and with a ventilation space between the planar portions 12. The heat transfer fins 21 that are arranged and bent in a waveform are arranged and stacked in each ventilation space. The heat transfer fins 21 are brazed to both surfaces of the flat portion of the heat transfer tube 11. More specifically, a brazing material is provided on both surfaces of the flat portion of the heat transfer tube 11, and a plurality of heat transfer tubes 11 provided with the brazing material and the heat transfer fins 21 are laminated and heated in a brazing furnace or the like. As a result, the heat transfer tubes 11 and the heat transfer fins 21 are brazed. In the flat plate-like outdoor heat exchanger 7, as shown in FIG. 3, the upper end of the fin edge portion 23 is one side in the width direction of the flat portion 12 (the direction facing the downstream side of the outdoor air flow). The fin edge 23 in which 27 and the lower end 28 are formed protrudes. Further, with respect to the other side in the width direction of the flat portion 12 (the direction facing the upstream side of the outdoor air flow), the fin edge portion 23 where the upper end 27 and the lower end 28 are not formed protrudes to the upstream side of the outdoor air flow.

  Here, the number of straight tubular flat tubes 11 required for a predetermined number of stacked layers (100 to 300) is prepared. Further, as many heat transfer fins 21 as necessary for a predetermined number of stacked stages (100 to 300 stages) are prepared. As a result, the fin-tube laminate 100 (a) is formed by alternately stacking the heat transfer fins 21 and the flat tubes 11 as shown in FIG.

  Further, both ends of each flat tube 11 are connected to headers 48 and 49 as shown in FIG. There are two types of headers 48 and 49, and the fin-tube laminates 100 (a) and 100 (b) are connected to the first header 48 one by one. On the other hand, two fin-tube laminates 102, that is, two rows of fin-tube laminates 100 (a) and 100 (b) are connected to the second header 49. That is, the second header 49 is shared by the two fin-tube laminates. Thus, the heat exchanger 7 has a total of two rows of fin-tube laminates. Here, the length L of the heat exchanger 7 is 1000 mm to 2500 mm, the height H is 700 mm to 1300 mm, the thickness t is 24 mm to 60 mm, and the thickness of the heat transfer fins 21 is 100 μm or less. The plurality of flow path holes 131 have a square shape of 250 μm × 250 μm, which is a so-called microchannel heat exchanger.

  Next, the bending of the flat outdoor heat exchanger 7 is performed using the bending apparatus 120. The part to be bent and the bending curvature of the heat exchanger are determined by the dimensions and the internal structure of the outdoor unit. As shown in FIG. 5, the bending apparatus 120 includes a gripping device 122, a guide unit 121, a drive device (not shown) such as an actuator that drives the gripping device 122, a control unit (not shown), and the like. ing.

  In the first step, when a gripping part that is adjacent to the first end of the bending target part is gripped, the bending curvature is determined. The control unit selects the gripping position of the gripping device 122 and the movement locus of the gripping unit 111 of the heat exchanger 7 based on the bending position and the bending curvature.

となるようにする。 In the second step, the control unit selects the movement locus at the center of the gripping unit. In this case, the coordinates are

To be.

The process of calculating the coordinates of this movement trajectory is as follows.

  In the above formulas (1) to (5), Co is the center of the gripping part, θi is the angle θi (defined by θi = ωt) formed by the gripping part and the X axis, and Ci is when the bending process proceeds The center of the gripping part, ρ is the radius of curvature when the bending process is advanced by θi, ω is the angular velocity, t is time, and W is the width of the gripping part. P is the center of the bent part, Ao is the adjacent point between the bent part and the gripping part, and Ai is the adjacent point between the bent part and the gripping part when the bending process proceeds.

  In the third step, the gripping device 122 is moved in the direction of arrow X by an actuator (not shown) while the gripping device 122 grips the gripping portion 111 of the heat exchanger 7. As a result, the flat plate heat exchanger 7 bends in the direction of the arrow X. Here, the heat exchanger 7 is bent in a state where the contact surface of the free portion 113 which is the second end of the bending target portion is in contact with the guide portion 121.

  In this heat exchanger bending method, only one portion of the gripping portion 111 of the heat exchanger is gripped, and the orientation of the gripping portion is controlled so that the gripping portion draws a predetermined trajectory without using a bending die. Bending is performed. At that time, the contact position of the free part 113 of the heat exchanger that is not gripped with the guide part 121 is determined by a reaction force generated during bending.

  Therefore, no restraining force is generated in the free portion 113 that is not gripped, and the occurrence of buckling in the heat exchanger 7 during bending can be avoided.

  Further, in this bending method, since there is no bending die, the fin does not receive a force from the bending die at the time of bending, and the fin collapse can be avoided. Even when the design of the bending radius is changed, it is possible to change the bending radius only by inputting a numerical value into the program, and it is not necessary to manufacture an expensive bending die having a long delivery time.

  Here, although the bending apparatus 120 includes the guide part 121, the bending part may not be provided with a guide part, and a free part that is not gripped may be brought into contact with a flat surface such as a table.

-Other embodiments-
As mentioned above, although embodiment of this invention was described based on drawing, specific structure is not restricted to said embodiment and its modification, It can change in the range which does not deviate from the summary of invention.

(A)
In the above embodiment, the present invention is applied to the outdoor heat exchanger 7 using a flat multi-hole tube as the heat transfer tube 11 and using a bridge fin as the heat transfer fin. It is not limited.

  For example, as shown in FIG. 8, the present invention may be applied to an outdoor heat exchanger 207 using normal corrugated fins instead of bridge fins as heat transfer fins.

  The heat transfer fin 244 shown in FIG. 8 is made of aluminum or aluminum alloy, and has a wave shape in which a peak portion and a valley portion are repeatedly formed between the plurality of flat heat transfer tubes 243 in a front view. . The heat transfer fin 244 has a plate-like portion that spreads flat from the peak portion to the valley portion, and the plate-like portion has a guide portion S for increasing the heat transfer area. Further, the heat transfer fin 244 is provided with a first guide G1 and a second guide that do not have a surface tension sufficient to hold condensed water near the downstream end in the air flow direction. For this reason, the dew condensation water guided to the downstream end of the heat transfer fin 244 by the air flow does not stay at the downstream end of the heat transfer fin 244, but follows the first guide G1 and the second guide G2 by its own weight. It is easy to flow down.

  Further, in the cross section perpendicular to the longitudinal direction of the corrugated fin shown in FIG. 8, the cross sectional shape of the corrugated fin is substantially triangular, but is not limited thereto. In the cross section perpendicular to the longitudinal direction of the corrugated fin, the cross-sectional shape of the corrugated fin may be rectangular.

(B)
Further, as shown in FIG. 9, the present invention may be applied to an outdoor heat exchanger 307 that uses insertion fins as heat transfer fins.

  Here, as shown in FIG. 10, the insertion fin has a plurality of cutout portions that match the cross-sectional shape of the flat multi-hole tube, and heat transfer for insertion from a direction perpendicular to the arrangement direction of the flat multi-hole tube. Point to the fin.

FIG. 9 is an external perspective view of an outdoor heat exchanger 307 using insertion fins, and FIG. 10 is a cross-sectional view of the insertion fins. The outdoor heat exchanger 307 includes a flat multi-hole tube 353, insertion fins 354, and headers 351 and 352.

  The flat multi-hole tube 353 is formed of aluminum or an aluminum alloy, and has upper and lower flat portions serving as heat transfer surfaces, and a plurality of internal flow paths 353a through which a refrigerant flows. The flat multi-hole tubes 353 are arranged in a plurality of stages at intervals in a state where the plane portion is directed up and down.

  The insertion fins 354 are aluminum or aluminum alloy fins having the shape shown in FIG. 10 and are in contact with the flat multi-hole tube 353. The insertion fin 354 is formed with a plurality of cutouts 354a that are elongated horizontally. The shape of the notch 354a of these insertion fins 54 is a flat multi-hole tube so that the insertion fins 354 can be inserted into the multi-stage flat multi-hole tube 353 arranged between the headers 351 and 352. It substantially matches the outer shape of the cross section 353.

(C)
In the above embodiment, the present invention is applied when the outdoor heat exchanger 7 is bent so as to be substantially L-shaped, but the present invention is not limited to this.

  For example, the present invention may be applied when bending the outdoor heat exchanger 7 so as to form a substantially U shape.

(D)
In the above embodiment, the present invention is applied to the outdoor heat exchanger 7 constituting the outdoor unit, but the present invention is not limited to this.

  For example, the present invention may be applied to an indoor heat exchanger constituting an indoor unit, a heat exchanger in another type of air conditioner, and the like.

  The present invention provides a bending method for a heat exchanger that performs bending on at least a part of a flat plate heat exchanger having a large number of heat transfer tubes and heat transfer fins positioned between adjacent heat transfer tubes. Widely applicable.

7 outdoor heat exchanger 11 heat transfer tube 21 heat transfer fin 111 gripping part 112 free part 120 bending device 121 guide part 122 gripping device

JP-A-6-347186 Japanese Unexamined Patent Publication No. 7-47427

Claims (9)

It is a kind of heat exchanger bending method, and its features are
A first step of gripping a gripping portion that is a first end of a portion to be bent of the heat exchanger;
A second step of selecting a movement trajectory of the center of the grip portion based on a bending position and a curvature of curvature;
The posture is changed while moving the gripping part so as to draw the movement locus, and the free part which is the second end of the bending target portion is in contact with one guide surface in the moving process. 3 steps,
Bending method of heat exchanger equipped with The bending method of the heat exchanger according to claim 1, wherein the bending method is completed using a bending apparatus, and the bending apparatus includes a gripping device, a guide unit, A driving device that drives the gripping device and a control unit that controls movement of the gripping means, and the guide surface is a contact surface between the guide portion and the free portion. It is the bending method of the heat exchanger of Claim 1 or 2, Comprising: The characteristic is
In the third step, when the gripping portion moves, the contact surface of the free portion is slidable with respect to the guide portion. It is the bending method of the heat exchanger of Claim 1 or 2, Comprising: The characteristic is
The coordinates of the movement locus at the center of the gripping part in the second step are:

Selected to be
Of these, Co is the center of the gripping part, θi is the angle θi formed by the gripping part and the X axis (defined by θi = ωt), Ci is the center of the gripping part when bending is advanced, and ρ is only θi The radius of curvature when the bending process proceeds, ω is the angular velocity, t is the time, and W is the width of the gripping portion. The heat exchanger includes a plurality of heat transfer tubes and heat transfer fins arranged in the valleys of adjacent heat transfer tubes, and performs heat exchange between the refrigerant flowing in the heat transfer tubes and the air flow across the heat transfer tubes. Is what
The heat transfer tube is a flat multi-hole tube in which a plurality of flow path holes arranged in the width direction are formed.
The bending method of the heat exchanger of any one of Claims 1-4. The heat transfer fin is a corrugated fin constituted by a wave-like fin bent in a waveform along the longitudinal direction of the heat transfer tube,
The heat exchanger is manufactured by laminating corrugated fins and the flat multi-hole tube.
The method for bending a heat exchanger according to claim 5. In the cross section perpendicular to the longitudinal direction of the corrugated fin, the cross-sectional shape of the corrugated fin is rectangular,
Edges of the wavy fins adjacent in the vertical direction are in contact with each other,
The method for bending a heat exchanger according to claim 6. The flat multi-hole tube is arranged in a plurality of stages,
A plurality of rows of heat transfer fins to be inserted from a direction perpendicular to the arrangement direction of the flat multi-hole tubes are inserted,
The heat transfer fin has a plurality of notches that match the cross-sectional shape of the flat multi-hole tube.
The method for bending a heat exchanger according to claim 5. The thickness of the heat transfer fin is 100 μm or less,
The heat transfer fins are brazed to the heat transfer tubes,
The method for bending a heat exchanger according to any one of claims 5 to 8.

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