CZ383696A3 - Process for producing flat tubes for heat-exchange apparatus - Google Patents

Abstract

A process for producing a flat heat exchange tube (A) having parallel refrigerant passages (6) in its interior and comprising flat upper and lower walls (1,2), opposite side walls (3,4) and a plurality of reinforcing walls (5) connected between the upper and lower walls (1,2), extending longitudinally of the tube (A) and spaced apart from one another by a predetermined distance, using a rolling mill (33) comprising a central work roll (35) and a plurality of planetary work rolls (36) arranged around a portion of the periphery of the central work roll (35) and spaced apart circumferentially thereof, the central work roll (35) being formed with parallel annular grooves (39,40) in the periphery thereof. An aluminum sheet blank (30) comprising a brazing sheet is rolled by the mill (33) and thereby thinned to a predetermined thickness to form a flat portion serving as the lower wall (2), cause the annular grooves (39) at opposite roll ends to form upright portions (12) providing the respective side walls (3,4) and the other annular grooves (40) to form vertical ridges providing the reinforcing walls (5), the upright portions and the vertical ridges projecting from the flat portion integrally therewith. An aluminum sheet (20) comprising a brazing sheet is placed over all the ridges to provide the upper wall (1) and joined to the upright portions to make the upright portions serve as the opposite side walls (3,4), and the ridges of the lower wall are joined to the upper wall to form the reinforcing walls (5).

Description

Method for manufacturing flat heat exchanger tubes

Technical field

G L 8 £ 5.0

The invention relates to a process for the production of flat tubes, in particular flat tube exchangers, condensers, evaporators and similar heat exchangers used in vehicle radiators.

BACKGROUND OF THE INVENTION

JP-B 45300/91 discloses a condenser for use in vehicle radiators comprising two chambers arranged parallel to the left and right and spaced from each other, parallel flat heat exchanger tubes, each of which is connected to chambers on its opposite ends, of corrugated fins in the airflow space between adjacent heat exchangers and adjacent brazed tubes, the inlet pipe being connected to the upper end of the left chamber and the outlet pipe connected to the lower end of the right chamber, with the left bulkhead located approximately in the middle of the left chamber; a right baffle, located below its center, consists of a series of heat exchanger pipes between the inlet pipe and the left bulkhead, a series of heat exchanger pipes between the left bulkhead and the right bulkhead and a series of heat exchanger pipes between the right bulkhead and the outlet pipe, wherein the number of heat exchanger tubes decreases from top to bottom. The refrigerant flowing into the inlet pipe in the vapor phase flows through the condenser back and forth before it flows out of the outlet pipe in the liquid phase. Capacitors of the described design are called parallel flow capacitors or multiflow, excel in high efficiency, low pressure drop and excellent compactness, and in recent years have been widely used instead of conventional serpentine

- 2 capacitors.

It is required that the heat exchanger tube for use in the condensers is pressure resistant as the refrigerant is introduced into it in the form of a high pressure gas. To meet this requirement and to achieve high heat exchange efficiency, the exchanger tube is made of an extruded hollow aluminum product having a flat top and bottom walls and a reinforcing wall connecting the top and bottom walls. In order to improve the heat exchange efficiency and to increase the compactness of the capacitors, it is desirable that the flat heat exchanger tube has a small wall thickness and the lowest possible height. However, in the case of extruded articles, the extrusion technique imposes limitations on the reduction of tube height and wall thickness.

To overcome this problem, U.S. Pat. No. 5,533,377 discloses a method of manufacturing flat heat exchanger tubes, the invention relates to a flat metal tube having two parallel coolant passages inside and consisting of a flat top and a bottom wall and a series of reinforcing walls connected between the top and bottom. wall and running along the pipe and spaced from each other at a predetermined distance. The known method consists in rolling a metal sheet with a thickness greater than the wall of the exchanger tube to be manufactured by a pair of upper and lower rollers, one of which has parallel annular grooves, thereby reducing the sheet thickness to a specified tube wall thickness by circumferential roller surfaces to form a flat portion serving at least one of two, an upper or lower wall and forming vertical ridges protruding from the flat integral with it and forming a reinforcing wall with annular grooves.

However, the problem of the described method is that a manufacturing apparatus is used which is generally of large dimensions, since the sheet metal strip must pass through a series of rollers.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for manufacturing flat heat exchanger tubes by a manufacturing apparatus. which can be compact in its entirety.

SUMMARY OF THE INVENTION. METHOD FOR MANUFACTURING A FLAT HEATER TUBE WITH INSIDE PARALLEL COOLING THROUGH AND consisting of a flat top wall and a bottom wall to which the cooling fins are attached, and a series of reinforcing walls connected between the top and bottom walls extending along the pipe and spaced apart in predetermined According to the invention, a finishing mill with a central forming roller and a series of planetary forming rollers arranged along a portion of the periphery of the central forming roller and spaced circumferentially from each other is used, wherein the central forming roller or planetary forming rollers have parallel annular peripheral rollers. grooves, and the sheet metal strip is rolled on a finishing mill, thereby reducing the sheet metal strip thickness to a specified value by the peripheral surface of the central work roll and the planetary forming circuitry. The rollers form flat portions serving as at least one upper wall and a lower wall and form integrally with the flat portion vertical ribs protruding from the flat portion and form reinforced walls formed by parallel annular grooves.

The roll stand preferably has a guide base between a pair of adjacent planetary forming rollers and means for pressing the guide base against the central forming roller. These bases suppress the longitudinal extension of the sheet metal strip as it passes through the roll stand and further prevents buckling between adjacent working rolls. As a result, the forming roller or rollers having parallel annular grooves impart a specified cross-sectional configuration to the rolled sheet. In order to reliably obtain a rolled sheet with a specified cross-sectional configuration, it is desirable to arrange several planetary forming rollers relative to the central forming roll such that the rolling clearance gradually decreases even against the direction of movement of the sheet metal strip.

fk

It is also required that rollers with parallel annular grooves and parallel shallow annular grooves between each of the two adjacent annular grooves be used as a central forming roller or as each of the planetary forming rollers to form a heat transfer surface by raising low ribs projecting integrally from the flat portion when forming vertical ribs projecting integrally from the flat portion, and forming reinforcing walls with annular grooves,

It is also desirable that a cylinder formed with parallel annular grooves and protrusions provided at a predetermined interval in each of the grooves and having a height less than the depth of the groove be used as a central forming roller or as each of the planetary forming rollers while forming vertical ribs protruding integrally from the flat portion and forming the reinforcing walls with annular grooves, a series of t slots were formed at a predetermined interval at the upper edge of each rib to form openings to provide communication between parallel refrigerant passages.

The communication openings in the reinforcing walls allow the coolant flowing through the parallel coolant passages also to flow across the flat heat exchanger tubes, thereby mixing the coolant parts with each other to eliminate temperature differences between the passages. The luminous ratio, which is the percentage of all communication openings in each reinforcing wall to the wall, is preferably 10 to 40%. If within this range, the luminous ratio provides satisfactory heat conduction, thereby providing considerably improved heat exchange efficiency of the heat exchanger tube. If this ratio is less than 10, the heat conduction does not increase while it even exceeds 40 X, the heat conduction no longer increases and only the coefficient of friction increases. The light ratio in the range of 10 to 40% is preferably 10 to 30%, most preferably about 20%.

The clearance of the communication openings is selected so that the refrigerant can flow smoothly between adjacent passages, so that there is no likelihood of solder fouling during soldering, and that the exchanger tube's pressure resistance is not impaired. The spacing of the communication openings is such that the openings do not reduce the pressure resistance of the tube while allowing a smooth flow of the refrigerant through the reinforcing walls. The communication openings formed in the row of reinforcing walls are preferably in a staggered configuration when viewed from above.

The spacing of the reinforcing walls in the direction of the pipe width is preferably up to 4 mm. If the spacing increases above 4 mm, this results in lower thermal efficiency. The height of the reinforcing walls is preferably up to 2 mm. If the height is greater than 2 mm, there will not only be difficulties in producing a compact heat exchanger, but also resistance to the passage of air will increase, resulting in a deterioration in thermal efficiency.

The invention is illustrated, but not limited, by the following examples.

Picture list

Fig. 1 is a cross-sectional view of a flat heat exchanger tube made by the method of the first embodiment of the invention.

FIG. 2 is an enlarged partial cross-sectional view of the flat heat exchanger tube of FIG. 1.

Fig. 3 is a sectional view taken along line 3-3 of Fig. 1.

In FIG. 4 is a schematic illustration of a device for manufacturing the lower tube assembly of FIG. 1.

Fig. 5 is an enlarged sectional view taken along line 5-5 of Fig. 4.

FIG. 6 is an enlarged partial axonometric cross-sectional view showing the peripheral surface of the central forming roller in the apparatus of FIG. 4.

Fig. 7 is a cross-sectional view of the lower tube assembly member of Fig. 1. Fig. 8 is an enlarged, fragmentary, axonometric cross-sectional view showing an aluminum sheet rolled on the rolling mill of the machine shown in Fig. 4.

Fig. 10 is a cross-sectional view showing the upper component member mounted on the lower component member by the method of the first embodiment of the invention.

Fig. 11 is an axonometric view of an apparatus for assistingly securing the upper component member to the lower component member by a first embodiment of the invention.

Fig. 12 is a cross-sectional view of a flat heat exchanger tube made by the method of the second embodiment of the invention.

Fig. 13 is an enlarged partial cross-sectional view of the flat heat exchanger tube of Fig. 12.

FIG. 14 is an axonometric view showing how the upper component member and the lower component member are joined by the method of the second embodiment of the invention.

Fig. 15 is a cross-sectional view showing the upper component member mounted on the lower component member by the method of the second embodiment of the invention.

Fig. 16 is a cross-sectional view of a flat heat exchanger tube made by the method of the third embodiment of the invention.

Fig. 17 is a partial cross-sectional view of the tube assembly member of Fig. 16.

Fig. 18 is a partial view corresponding to Fig. 5 showing the finishing mill for preparing the component member of Fig. 17.

Fig. 19 is a cross-sectional view of a flat heat exchanger tube manufactured by the method of the fourth embodiment of the invention.

Fig. 20 is a partial cross-sectional view of the tube assembly member of Fig. 19.

Fig. 21 is a cross-sectional view of a flat heat exchanger tube made by the method of the fifth embodiment of the invention.

Fig. 22 is a partial cross-sectional view of the tube assembly member of Fig. 21;

Fig. 23 is a cross-sectional view of a flat heat exchanger tube made by the method of the sixth embodiment of the invention;

Fig. 24 is a perspective cross-sectional view of the attachment of the upper component member to the lower component member by the method of the sixth embodiment of the invention.

Fig. 25 is a front view of a flat-tube condenser according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

The term aluminum as used herein refers to pure aluminum and aluminum alloys. In all figures, like parts are designated with the same reference numerals and are not described repeatedly.

Fig. 25 shows a condenser with flat heat exchanger tubes according to the invention. The condenser consists of a pair of parallel and spaced chambers, a left chamber 121 and a right chamber 122, parallel flat heat exchanger tubes.123, each connected to the left chamber 121 and to the right chamber 122, corrugated fins 124 in the air flow passage between adjacent heat exchanger tubes 123 and brazed to adjacent heat exchanger tubes 123, further comprising an inlet tube 125 connected to the upper end of the left chamber 121 and an outlet tube 126 connected to the lower end of the right chamber 122, a left bulkhead 127 within and around the left chamber 121 from the right partition 128 within the right chamber 122 and located below the center thereof, from a series of heat exchange tubes 123 between the inlet tube 125 and the left partition 127 and a right partition 128 a. is from top to bottom. The refrigerant flowing into the inlet pipe 125 in the vapor phase flows through the condenser back and forth before it flows out of the outlet pipe 1.26 in the form of a liquid phase,

The flat heat exchanger tubes in the condensate described above are according to the invention. Examples of heat exchanger tubes according to the invention are described below. In the following embodiments, the lightness ratio of the reinforcing walls is 10 to 40%, which is the percentage of all communication openings formed in the reinforcing wall relative to the wall. The communication openings formed in the row of reinforcing walls are preferably in a staggered configuration when viewed from above. The brazed component is degreased before brazing and then coated with a solder flux.

Embodiment 1

This embodiment is shown in FIGS. 1 to 11. In this embodiment, the flat heat exchanger tube A shown in FIGS. 1 to 3 consists of a flat top wall 1 and a flat bottom wall 2 to which the slats are connected, a vertical left side wall 3, and a vertical right side wall 4 connected between opposing edges of the flat top wall 1 and the flat bottom wall 2, of a series of reinforcing walls 5 arranged between the left side wall 3 and the right side wall 4 connected between the surface an upper wall 1 and a flat lower wall 2 extending along the flat heat exchanger tube A and spaced apart by a predetermined distance. Inside the flat heat exchanger tube A there are parallel passages 6. Between adjacent reinforcing walls 5, low ribs 7 are formed, increasing the heat exchange surface integrally on the upper surface of the flat bottom wall 2. At the upper end of each reinforcing wall 5 is a row of trapezoidal communication openings 8 providing communication between parallel passages 6. refrigerant.

The flat heat exchanger tube A consists of a flat plate-shaped upper component 20 forming a flat top wall i and a lower ridge-shaped component 10 having a flat section XX forming a flat bottom wall 2 left and right with a web 12 forming a left side wall 3; the right side wall 4, the ribs 13 forming the reinforcing walls 5 and the low ribs

7. increasing the heat transfer surface. Each web 12 of the lower component member 10 has a step 12a at the same height as the upper end of the rib 13 and an upper thin wall 15 extending over the step. The upper component member 20 has a bevel 21 inclined outwardly downwardly and forming an upper surface of each of the opposite side portions. The upper thin wall 15 is fixed to the bevel 21 by bending. Each rib reinforcement 13 has trapezoidal cut-outs 14 forming communication openings.

Flat exchanger tube A is produced as follows:

First, a lower component member 10 shown in Figures 7 and 8 is prepared by the machine shown in Figures 4 to 6.

Referring to FIG. 4, the machine for manufacturing the lower component member 10 consists of an unwinder 31 having an aluminum strip 30 (in the form of an aluminum solder wound from a sheet metal upstream roll top with a solder layer solder thereon), and a finishing mill The aluminum strip 30 from the unwinder 31 passes through the pre-rolling stand and is fed to a finishing stand 3 3 where it is unwound. 32, then it is finely rolled to form the lower component member 10.

Referring to FIG. 9, the roll stand 32 aligns the aluminum strip 30 on the opposite side of the brazing material layer such that thick flanges 30a protrude at opposite edges.

The finishing mill 33 has a central forming roller 35 and a series of planetary forming rollers 36 arranged equidistantly along a portion of the periphery of the central forming roller 35. In relation to the central forming roller 35, the planetary forming rollers 36 are arranged such that the rolling gap gradually decreases in the direction of the advancing aluminum strip 30.

The drive (not shown) rotates the central forming roller 35. The planetary forming rollers 36 are rotatable with a rotating central forming roller 35 with a gear (not shown), so that by rotating the central forming roller 35, the planetary forming rollers 36 rotate at the same peripheral speed as the central forming roller 35. The finishing mill 33 further has trapezoidal guide bases 37 between each of the immediately adjacent planet forming rollers 36 and springs 38 to press the trapezoidal guide legs 37 against the central forming roll 35. With their front and rear edges, the guide bases 37 extend into the gap between the central forming roller 35 and the planetary forming roller 36 to the extent that the trapezoidal guide bases 37 do not touch these rollers. Trapezoidal guide bases 37 suppress the longitudinal extension of the aluminum strip 30 as it passes through the finishing roll stand 33 and further prevent the strip from buckling between adjacent planetary forming rollers 36. The longitudinal extension of the strip is also suppressed by rotating all of the planetary forming rollers 36 at the same peripheral speed as that of the central forming roller 35. Since the longitudinal extension of the aluminum strip 30 is suppressed, the strip may have a smaller thickness than conventional aluminum sheet. This reduces material costs and the rolling reduction may be less than that of the prior art.

parallel grooves 39

Referring to Figures 5 and 6, the central forming roll 35 of the finishing mill 33 is provided with circumferential grooves (wider annular and narrower annular grooves 40) circumferentially having the same depth, and the trapezoidal protrusions 43 are formed at a predetermined amount. an interval of each of the narrower annular grooves 40 other than the annular grooves 41 at opposite ends, the trapezoidal protrusions 43 having a height less than the depth of the narrower annular grooves 40. The wider annular groove 39 at each opposite end has a greater width than the others. narrower annular grooves 40 and is further formed with a small width annular groove 41 at the outer edge of its bottom. Further, shallow annular grooves 42 are formed in the central forming cylinder between each pair of immediately adjacent narrower annular grooves 40.

The aluminum strip 30 shown in FIG. 9 with thick flanges 30a and passage through them is rolled by 35 and planetary FIG. 7, rolling with thin-walled portions 30b between the central forming roller by rollers 36. As can be seen from the operation, the aluminum strip 30 is thinned to a predetermined thickness by forming a flat portion 11 providing a flat bottom wall 2 and a wider annular groove 39. create webs 12. thereby securing the left side wall 3 and the right side wall 4 and the ribs 13 forming the reinforcing walls 5, wherein the webs 12 and the ribs 13 protrude integrally from the flat portion 11. Further, the trapezoidal protrusions 43 in each narrower annular groove 40 form trapezoidal cutouts 14 in the upper end of the rib at a predetermined interval, and the grooves form ribs 13 increasing the heat exchange surface similarly projecting integrally from the flat portion 11. The annular grooves 41 of small width form at the upper portion of the webs 12 of greater thickness than the ribs 13 of the step 12a at the same height as the upper ends of the ribs 13 and a vertical upper thin projecting from each step 12a.

wall 15.

It is now believed that the lower component 10 shown in FIG. 7 should have a total width W = 18 mm, a thickness of the flat part 11 T-0.35 mm, a web height 12 H = 1 mm, its thickness Tl = 1 4 mm, height of vertical thin walls HI = 0.65 mm, their thickness T2 = 0.4 mm, rib height 13 H2 = 1 mm and their thickness T3 = 0.4 mm, rib spacing 13 P = 0.8 mm , the height of the low ribs Ί_ H3 = 0.2 mm and their thickness T4 = 0.2 mm. In this case, it is assumed that the aluminum strip 30 shown in FIG. 9 has a width = w, a width = w1 of the thick flange 30a, a thickness = t of the thin wall portion 30b and a thickness = tl of the thick flange 30a.

The lower component member 10 can then be prepared with said drawing dimensions when w = 18 mm, wl = 1.34 mm, t = 0.57 mm, and tl = 1.13 mm when w = 18 mm, wl = 1, 48 mm, t = 0.62 mm and tl = 1.19 mm and when w = 19 mm, wl = 1.63 mm, t = 0.68 mm and t = 1.25 mm.

The aluminum strip 3C of FIG. 9 has thick flanges 30a which are formed either by allowing one side to exit on the opposite side of the brazing material, or by allowing the side with the brazing material layer to exit, or by allowing both sides to obtain thick flanges. parties get off.

Separately from the lower component member 10, an upper component member 20 is prepared from a flat aluminum sheet in the shape of an aluminum brazing sheet with a layer of brazing material on opposite sides thereof and shaped with a bevel 21 inclined outwardly downwardly on the upper surface of each edge thereof (Fig. 8) . The upper component member 20 is temporarily attached to the lower component member 10 by placing the upper component member 20 at both edges on the stepped portion of the web of the lower component member, the upper thin wall 15 of each web 12 bending inwardly thereby tightening the upper This operation is carried out continuously in a jig having pairs of upper and lower forming rollers 80 to bend the upper thin walls 15 and pairs of upper and lower clamping rollers 81 to attract the upper, component member 20 to the lower the component member 10 from above and below, as shown in FIG. 11.

Then, the pre-locked assembly is sheared to the specified lengths to obtain heat exchanger tube blanks. The assembly is therefore sheared by scissors in the direction of the height of the article, i.e. from top to bottom. This prevents deformation of the webs 12 and ribs 13. These parts are easily deformed when cut in the width direction, i.e. from left to right.

The thus prepared exchanger tubes sc are soldered together with chambers and lamellas. In this case, the upper component 20 is placed on the ribs 13 to form the flat upper wall X of the flat heat exchanger tube A, the upper thin walls 15 of the upper component 20 are brazed to the stepped portions of the respective webs 12 of the lower component 10 as the left side wall 3 and the right side wall X, the ribs 13 of the flat bottom wall 2 are soldered to the flat top wall 1 to form the reinforcing walls 5 and the openings of the trapezoidal cutouts 14 in the ribs 13 are closed by the flat top wall X, thereby communication openings 6 for maintaining parallel coolant passages 6 coolant. A flat exchanger tube A is obtained.

The assembly of the upper component member 20 and the lower component member 10 pre-locked may be pre-coupled by high frequency brazing prior to said brazing operation. Alternatively, the upper component member 20 and the lower component member 10 may be brazed together to obtain the end product of the heat exchanger tube. The chambers and fins can then be brazed to such tubes to form a heat exchanger.

Embodiment 2

This embodiment is shown in Figures 12-15. The method of this embodiment provides a flat heat exchanger tube A1, which is of the same construction as the tube of embodiment 1, except that the left side wall 50 and right side wall 51 have a double structure as shown in FIG. 12 and 13.

The flat heat exchanger tube A1, consisting of the lower component member 60 and the upper component member 70, has the same construction as the tube of embodiment 1 except for the following features. The lower component member 60 has left and right webs 61 of the same height and thickness as the ribs 5 and 5

14, each side edge of the flat portion 11 is a bevel 62. The upper component member 70 has on each side of its edge a vertical portion 72 of the same thickness as the web 61 at its lower end beveled inwardly so that it can be curved to the web 62. The upper component member 70 is so wide that the vertical portions 72 can be mounted externally on respective webs 61 of the lower component member 60.

The flat heat exchanger tube A1 is prepared as follows. 4 and 5, the lower component member 60 is preformed and operated as in Embodiment 1 with the following exception (FIG. 14).

The machine according to this version is not equipped with a rolling mill 3 2. Therefore, a flat aluminum sheet in the form of an aluminum strip with solder material is fed on one side to the finishing mill 33. The central forming roll 35 of the finishing mill 33 has parallel annular grooves on its periphery, all of which have the same width and depth, except that only the annular grooves at opposite ends have a lower face connected to the outer side face by a bevel,

Separately from the lower component member 60, the upper component member 70 is formed from an aluminum sheet in the form of an aluminum strip coated with a layer of brazing material on its opposite side and having vertical portions 72 at opposite side edges. The vertical portions 72 are slightly higher than the webs 61 and are chamfered in and down at the lower end 73.

Then, the upper component member 70 is mounted on the lower component member 60 and the lower ends 73 of the vertical portions 72 of the upper component member 70 are folded inwardly and thereby tightly attached to the webs 62 of the lower component member so that the upper component member 70 and the lower component member 60 tentatively joins. The procedure for obtaining the flat heat exchanger tube A1 is then carried out as in embodiment 1

Embodiment 3 opposite side edges of the bottom wall 87 and consists

This embodiment is shown in FIGS. 16 to 18. As shown in FIG. 16, a flat heat exchanger tube 42 of this embodiment is produced, which consists of a flat top wall 86 and a flat bottom wall 87. to which the slats are to be soldered, the left side walls 85, the right side walls 88, both of which have a rounded outer surface and are connected between the flat upper walls 86 and the flat further of a series of reinforcing walls 89 disposed between the left upper wall 85 and the right the side wall 88 and longitudinally extending in the tube A2 and are separated from each other by a predetermined distance. The pipe A2 has parallel refrigerant passages 74 within it. In the middle of each reinforcing wall 89, a hexagonal communication opening 90 is formed to communicate refrigerant in parallel passages 74.

Tube A2 is the only component 94. Referring to FIG. 17, the center portion 94 has a central flat portion 92 forming a right side wall 88, a right flat portion 91 forming a flat top wall 86, a right rib 89a forming the upper halves of the stiffening walls 89, and a left side wall 85 in the center width. the right flat portion 91, the right ribs 89a and the first rounded portion 85a are located to the right of the central flat portion 92. and a left flat portion 93 forming a flat bottom wall 87, wherein the left ribs 89b form the lower halves of the reinforcing walls 89 and the second rounded portion 85b form the lower half of the left side wall.

85, wherein the left flat portion 93, the left ribs 89b and the second rounded portion 85b are located to the left of the central flat portion 92. The right rib 89a. (left rib 89b) has a right trapezoid cutout 90a, (left trapezoid cutout 90b) to form the upper halves (lower halves) of the hexagonal communication holes 90.

The flat heat exchanger tube A2 is prepared as follows. 4 and 5, the component 94 is preformed and operated as in Embodiment 1.

The machine according to this embodiment is not equipped with a rolling mill 3 2. Therefore, a flat aluminum sheet in the form of an aluminum strip with solder material is fed on one side to the finishing mill 3. As can be seen in FIG. 18, the central forming roll 35 has a finishing annular groove 97 on its periphery. on either side of the center symmetrically spaced at a specified interval and a protrusion 99 with a height less than the depth of the parallel annular grooves 97. To the right of the rightmost parallel annular groove 97 has a central forming roller 35 having a right annular groove 95 with a depth and width greater than they have parallel annular grooves 97, delimited by a bottom and a vertical inner wall connected thereto by a bevel. To the left of the leftmost parallel annular groove 97, the central forming roller 35 has a left annular groove 96 with a depth and width greater than the parallel annular grooves 97 delimited by the bottom and a vertical inner wall connected thereto by a bevel. The planetary forming roller 36 is provided at its right end with a right flange 96a which is circumferentially in contact with the bottom of the right annular groove 95 and at its left end is provided with a left flange 98b which is peripherally in contact with the bevel of the left annular groove 9 6. The left flange 98b and the right flange 98a have an inwardly rounded inner face.

finishing rolling forming roll 3 5 thin aluminum strip

The aluminum strip 30 is rolled by a mill 33. formed by the central and planetary forming rollers 36 on a defined wall thickness by the outer surface of the central forming roller 35 and the planetary forming rollers 36 on the central flat portion 92. the right flat portion 91 and the left flat portion 93, wherein the parallel annular grooves 97 form ribs, the right ribs 89a and the left ribs 89b projecting integrally from the right flat portion 91 and the left flat portion 93 form right trapezoids on the protrusions 99 in parallel annular grooves 9.7. the slits 90a and left trapezoid slits 90b at a predetermined interval in the upper protrusions of the right ribs 8.9a. and the left ribs 89b and the opposing side edges of the aluminum strip fold in the direction of the right ribs 89a and the left ribs 89b, thereby forming a first rounded portion 85a and a second rounded portion 85b. The resulting aluminum sheet with right trapezoid cutouts 90a in the right ribs 89a and left trapezoid cutouts 90b in the left ribs 89b, i.e. the component 94 bends in the middle like a hairpin, creates a right side wall 98. The edges are soldered to join the first rounded and a second rounded portion 85b. Thus forming a left side wall 85. The downward right ribs 89a mate with the left ribs 89h facing up to form the reinforcing walls 89 with right-hand trapezoidal cut-outs 90a and left-hand trapezoid cutouts 9.0b combined into hexagonal communication openings 90 in the middle of the reinforcing wall. 8.9., Thereby ensuring coolant communication through parallel passages 7 4. A flat exchanger tube A2 is thus obtained.

Embodiment 4

This embodiment is shown in Figures 19 and 20.

The flat heat exchanger tube A3 shown in FIG. 19 has the same construction as the flat heat exchanger tube of Embodiment 1 except that each reinforcing wall 100 has trapezoidal communication openings 101 in the upper end and the reinforcing walls 100 have similar trapezoidal communication openings 101 alternately arranged at the lower end.

The tube A3 is a single member 102. As shown in FIG. 20, the member 102 has a central flat portion 92 in the center of its width forming the right side wall 88; the right flat portion 91 forming the flat top wall 86, the right ribs 100a forming the reinforcing walls 100, and the first rounded portion 85a forming the upper half of the left side wall 85 are located to the right of the central flat portion 92: and the left flat portion 92 forming the flat bottom wall 87, the left ribs 100b forming the reinforcing walls 100, and the second rounded portion 85b forming the lower half of the left side wall 85, which is located to the left of the central flat portion 92. The right ribs 100a have right trapezoidal cutouts 101a and left. the ribs 100b have left trapezoidal cutouts 101b forming communication openings. Right ribs 100a of the left flat portion. 93 is one less than the left ribs 100b of the right flat portion 9.1 and are offset against the right edge of the component 102 relative to the other ribs by 1/2 of the rib pitch.

The pipe A3 is produced in the same manner as the pipe of Embodiment 3, except for the following features of the central forming cylinder. While the central forming cylinder has parallel annular grooves on opposite sides from the center of its length, the grooves on the right side are offset from the grooves on the left by 1/2 of the groove spacing towards the right end of the cylinder and there are one less than the left grooves. The annular grooves have twice the depth of the annular grooves of embodiment 3.

By means of a central forming roll, a flat aluminum strip, i.e. a component 102 having a first trapezoidal cutout 101a and a second trapezoid cutout 101b, is rolled in the right rib 100a with the left rib 100b. The right side wall 88 is formed by bending the component 102 in the middle of its width as a hairpin, the left side wall 85 is formed by brazing the opposing edges, thereby joining the first rounded portion 85a and the second rounded portion 85b; the reinforcing walls 100 are formed by joining the right ribs 100a of the top wall 86 with the flat portion of the bottom wall 87 and the left ribs 100b of the bottom wall 87 alternately with the flat wall portion 86 and the openings first trapezoid slot 1.01aa and the second trapezoid slot IJT1b. are closed with a flat portion to form trapezoidal communication openings 101 in the parallel reinforcing walls 100 alternately in the upper and lower positions to maintain the parallel refrigerant passages 74 relative to each other.

Embodiment 5

This embodiment is shown in Figures 21 and 22.

By the method of this embodiment, a flat exchanger tube of the same design as in Embodiment 1 is obtained except that the trapezoidal communication openings 106 are at the lower ends of the reinforcing walls 105, as shown in FIG. 21.

The flat heat exchanger tube A4 is a single component 107. As shown in FIG. 22, the component 107 consists of a central flat portion 92 in the middle of its width to form a side wall 88; it further comprises a right flat portion 91 forming the top wall 86, ribs 105a forming the reinforcing walls 105 and an arcuate portion 85a forming the upper half of the left side wall 85, which are located on the right side of the central flat portion 92 '. it further comprises a left flat portion 93 forming a bottom wall 87 and a second rounded portion 85b forming a lower half of the left side wall 85 which are located on the left side of the central flat portion 92. The zebra 105a have trapezoidal cutouts 106a forming communication openings 106.

The flat heat exchanger tube A4 is manufactured in the same way as the tube of embodiment 3, except for the following features of the central forming cylinder. The central forming cylinder has parallel annular grooves only on the right side of its longitudinal central portion, and the annular grooves have twice the depth of the annular grooves of embodiment 3.

The flat heat exchanger tube A4 is made of a rolled aluminum plate, a component 107 obtained by a central forming cylinder and having cutouts 106a in the ribs 105a, bending the component 1737 in the center portion as a hairpin, to form the right side wall 88 and solder the butt opposite edges. coupling the first rounded portion 85a. with a second rounded portion 85b to form a left side wall 85, soldering the ribs 105a of the top wall 86 to the flat portion of the bottom wall 87 to form the stiffening walls 105, and closing the trapezoidal slot openings 106a in the ribs 105a with the flat portion to form the trapezoidal communication openings 1.06 in the lower, at the ends of the walls 105, to maintain coolant passages 74 parallel to one another.

Embodiment 6

This embodiment is shown in Figures 23 and 24.

By the method of this embodiment, a flat exchanger tube A5 of the same construction as in Embodiment 1 is obtained except that the flat exchanger tube A5 has a right side wall 110 with a circular outer surface and a vertical inner surface as seen in Fig. 23.

As shown in FIG. 24, the flat heat exchanger tube A5 forms the upper component member 112 and the lower component member 114. The upper component member 112 has a flat portion 111 forming a flat top wall 86, the first ribs 89a. forming the upper halves of the left side wall 85, and the first rounded portion 85a and the upper rounded portion 110a having a circular outer face form the upper halves of the opposite left side wall 85 and the right side wall 110. The lower component member 114 consists of a left flat portion 93 forming a flat bottom wall 87, first ribs 89a forming the lower halves of the reinforcing walls 89 and a second rounded portion 85b and a lower rounded portion 110b having a circular outer surface forming the lower half of the left side wall 85 and right side wall. 110. The first rib 89a, and the second rib 89b have corresponding first trapezoidal cutouts 90a and a second trapezoidal cutout 90b forming upper halves and lower halves of hexagonal communication openings 90.

The flat heat exchanger tube A4 is manufactured in the same way as the tube according to embodiment 3 except for the following features of the central forming cylinder 3 5. The central forming cylinder 35 has parallel annular grooves, only on the right side of its longitudinal central section and annular grooves twice the depth of the annular grooves. Embodiment 3.

Flat exchanger tube A5 is produced by following procedure:

First, with the machine as used in Embodiment 1 shown in Figures 4 and 5, it rolls the upper component member 11.2 and the lower component member 114.

In this case, they have a central forming roller 65. 18 and the right annular groove 95 of the central forming roller 35 and the right flange 96a of the planetary forming roller 36 are the same as the left annular groove 96 of the central forming roller 35 and the left flange. 98b of the planetary forming roller 36 mirrored symmetrically with only half of the portions of parallel annular grooves formed between opposing end grooves. The central forming roller 35 and the planetary forming roller 36 of the second machine finishing mill 33 have a cross-section corresponding to the same drawing, the left annular groove 96 of the central forming roller and the left guide 98b of the planetary forming roller 36 are respectively the right annular groove 95 of the central forming roller 35; the left flange 98b of the planetary forming roller 35 is mirror-symmetrical with only half of the portions of parallel annular grooves formed between opposing end grooves.

The aluminum strips, each forming a brazed sheet with brazing material on opposite surfaces, are rolled on both thin gauge rolls of a specified thickness to form a flat portion 111 and a lower flat portion 113, the annular grooves forming the first rib 89a, and the second rib. 89h extending integrally from the flat portion 11 and the lower flat portion 113, wherein the protrusions in the grooves form a first trapezoidal cutout 90a and a second trapezoidal cutout 90b at a specified interval at the upper edges of the first rib 89a and the second rib 89b and the opposite side edges bend in the projections the first rib 89a and the second rib 89b, thereby forming a first rounded portion 85a, an upper rounded portion 110a, a second rounded portion 85b, and a lower rounded portion 110b, each having a circular outer face. The rolled aluminum strips, i.e. the upper component member 112 and the lower component member 114 are butt-brazed on both sides, joining the first rounded portion 85a and the upper rounded portion 110a, the second rounded portion 85b and the lower rounded portion 110b having an annular outer face to obtain opposing side walls, with the flat portion 111 of the upper component member 112 and the lower flat portion 113 of the lower component member 114 serving as the flat top wall 86 and the flat bottom wall 87 and the first ribs 89a soldered to the second ribs 89b to form reinforcing walls 89 with a first trapezoidal cutout 90a and a second trapezoidal cutout 90b of the first fin 89a and the second fin 89b folded to form hexagonal communication openings 90 in the middle of the reinforcing walls 89 to maintain coolant passages 74 therebetween. In this way, a flat exchanger tube A5 is obtained.

The upper walls of the flat heat exchanger tubes of Embodiments 1 and 2, the upper and lower walls of the flat heat exchanger tubes of Embodiments 3 through R can be formed with low projections increasing the heat exchange surface as in the case of the lower wall of Embodiment 1.

In all of the preceding embodiments, the central forming roll of the finishing mill has different annular grooves, whereas such annular grooves may alternatively be formed in planetary forming rollers.

In all embodiments, the slits in the ribs are formed simultaneously when the aluminum strip passes through the finishing roll stand, while the slots may be formed separately when the strip passes through the roll stand. In this case, the protrusions need not be provided on the lower face defining the annular groove of the central forming cylinder.

S ubject usability

Flat coil tubes made by rolling aluminum strips are a suitable part of heat exchangers such as condensers, evaporators and coolers, especially in vehicles, as they increase the heat exchange surface and allow coolant communication between individual flow channels, thereby increasing the heat efficiency of the heat exchanger.

Claims (18)

- 24 PATENT CLAIMS A method of manufacturing a flat heat exchanger tube having, within it, parallel coolant passages and consisting of a flat top wall and a flat bottom wall to which cooling fins are attached, and a series of reinforcing walls connected along the upper and lower walls. tubes and spaced apart from each other at a predetermined distance, using a finishing mill with a central forming roller and a plurality of planetary forming rollers arranged along a portion of the periphery of the central forming roller and spaced circumferentially from each other, the central forming roller or planetary forming rollers having parallel narrower annular grooves, characterized in that the metal strip is rolled on a finishing mill, thereby reducing the thickness of the metal strip to a specified value by the peripheral surface of the central work roll and the circumferences of the planetary forming rollers forming flat parts serving as at least one upper the wall and the bottom wall a form integrally with the flat part the vertical ribs protruding from the flat part and form reinforced walls formed by parallel annular grooves. 2. The method of claim 1, wherein the finishing mill has a trapezoid guide shoe between each pair of immediately adjacent planetary rollers and means for urging the trapezoid guide shoe against the ingenious forming roller. 3. A method according to claim 1, wherein the central or each of the planetary rollers is a roll having wider annular grooves and parallel shallow annular grooves to form low heat exchanging ribs extending integrally from the flat portion. forming vertical ribs with annular grooves projecting integrally from the flat portion and forming reinforcing walls. 4. A method according to claim 1, wherein the central forming cylinder or each of the planetary forming rollers is cylinders having shaped parallel narrower annular grooves, and simultaneously with the narrower annular grooves, trapezoidal protrusions are formed at a predetermined interval at each predetermined interval. a narrower annular groove and having a height less than the depth of the narrower annular groove, wherein forming ribs protruding integrally from the flat portion and forming stiffening walls, a series of trapezoidal cutouts are formed at a predetermined interval at the upper edge of each rib to form hexagonal communication openings communication between parallel refrigerant passages. Method according to claim 4, characterized in that the slits are trapezoidal. 6. The method of claim 4, wherein each reinforcing wall has a brightness ratio of 10 to 40%, which is the ratio of all hexagonal communication openings in the reinforcing wall to the reinforcing wall. Method according to claim 4, characterized in that the communication openings formed in the row of reinforcing walls are in a staggered configuration as seen from above. 8. A method of manufacturing a flat exchanger tube having, within it, parallel refrigerant passages and consisting of a flat top wall and a flat bottom wall to which cooling fins are attached, and a series of reinforcing walls connected between the top and bottom walls extending along the tube and spaced apart at a predetermined distance, using a central forming roller finishing mill and a series of planetary forming rollers arranged along a portion of the periphery of the central forming roller and spaced circumferentially from each other, wherein the central forming roller or planetary forming rollers have parallel narrower annular grooves and protrusions at a predetermined interval in each of the annular grooves other than the annular grooves at opposite ends and having a lower height than the depth of the narrower annular grooves, characterized in that rolls a sheet of metal with a thickness greater than the bottom wall thickness of the exchanger tube to be manufactured on the finishing mill, thereby reducing the sheet metal thickness to a specified value by the peripheral surface of the central forming roller, and the circumferences of the planetary forming rollers form flat parts serving as a flat bottom wall; the annular grooves at the ends of the cylinder form the webs forming the respective side walls, and the other narrow annular grooves form the vertical ribs forming the reinforcing walls, the webs and vertical ribs projecting integrally from the flat portion forming protrusions in each slot forming slits in the upper edge of the ribs in advance at specified intervals and the metal plate is placed on all ribs to form the upper wall, the metal plate is attached to the webs, the webs serve as side walls, the ribs connect the lower a wall with an upper wall to form stiffening walls and to flip openings of cutouts in each fin through the top wall to form hexagonal communication openings to provide communication between parallel refrigerant passages. Method according to claim 8, characterized in that: characterized in that the annular grooves of small width at the ends of the cylinder have a greater width than the other narrower annular grooves and are formed at the outer end of their bottom by an annular groove of reduced width, wherein the metal strip is formed such that the webs are thicker than the low ribs and form a stepped portion with the same height as the lower ends of the ribs at the top of each web and an upper thin wall projecting from the stepped portion, the flat metal strip having a bevel on the upper surface at each side edge; each side edge of the metal sheet i It attaches to the stepped portion of the web, followed by joining the top thin walls of the web to the bevel of the metal strip by bending the thin wall inward and attaching the thin wall to the bevel. # ' 10. The method of claim 9, wherein the metal sheet has edges on each side ... the integral vertical part and the opposite right side wall and the left side wall are obtained by placing the vertical parts on the outside of the flat bottom wall to form a flat metal tube. 11. A method according to claim 10, wherein the flat portion forming the flat bottom wall is formed. it is rolled out of a metal strip, bevels are formed at each edge outwards and downwards, and the vertical portion is somewhat higher than the web, and has a bevel downward and inward towards the bottom and inwards to z and h and t. 12. A method of manufacturing a flat heat exchanger tube having parallel coolant passages therebetween and consisting of a flat top wall and a flat bottom wall to which cooling fins are attached, and a series of reinforcing walls connected between the top and bottom walls extending along the tube and spaced apart at a predetermined distance, using a central forming roll finishing mill with a plurality of planetary forming rollers arranged along a portion of the periphery of the central forming roller and spaced circumferentially from each other, the central forming roller or planetary forming rollers having parallel narrower annular grooves on the periphery opposite sides in the middle of the length with symmetrical protrusions at a predetermined interval in each of the annular grooves and having a height less than the depth of the narrower annular grooves, characterized in that: is rolled sheet metal 2'8 strips with a thickness greater than the bottom wall thickness of the exchanger tube to be manufactured on the finishing mill, thereby reducing the thickness of the metal strip to a specified value by the peripheral surface of the central forming roll and the planetary forming rollers to form a flat portion serving as a flat bottom wall wherein the annular grooves form ribs protruding integrally from the flat portion, the protrusions in each groove form slits in the upper edge of each rib at a predetermined interval, and at least one of the opposite side edges of the strip is bent towards the projecting ribs and the resulting metal strip having the ribs of the cut-outs, bend like a hairpin in the middle of the width of the plate, the side edges of the plate are butt-joined, thereby attaching the vertical ribs to the standing ribs to form stiffening walls and the cut-outs of the opposite ribs communication holes to ensure communication between the parallel refrigerant passages. 13. A method of manufacturing a flat exchanger tube having, within it, parallel refrigerant passages and consisting of a flat top wall and a flat bottom wall to which cooling fins are attached, and a series of reinforcing walls connected between the top and bottom walls extending along the tube and spaced apart at a predetermined distance, using a central forming roll finishing mill with a series of planetary forming rollers arranged along a portion of the periphery of the central forming roller and spaced circumferentially from each other, wherein the central forming roller or planetary forming rollers have parallel narrower annular grooves on opposite sides in the middle of the length, whereby the annular grooves on one of the opposite sides are offset by 1/2 of the groove spacing towards the one end of the cylinder relative to the annular grooves on the other side, forming provide symmetrical protrusions at a predetermined interval in each of the annular grooves and having a height less than the depth of the narrower annular grooves, such that a sheet metal strip with a thickness greater than the thickness of the bottom wall produced is rolled exchanger tubes on the finishing mill, thereby reducing the thickness of the sheet metal strip to a specified value by the peripheral surface of the central forming roller and the circumferences of the planetary forming rollers to form a flat bottom serving as a flat bottom wall, the annular grooves forming ribs projecting each groove cuts in the upper edge of each rib at a predetermined interval, and at least one of the opposite side edges of the strip is bent toward the projecting ribs, and the resulting metal strip having slits in the ribs is bent e like a hairpin in the middle of the width of the plate, the side edges of the plate are butt-jointed, thereby alternately attaching vertical ribs to the resulting top wall to the flat portion of the resulting bottom wall and the bottom wall ribs to the flat portion. top walls to form stiffening walls and to close the openings of the rib slots with the flat portions to form six gate communication openings to provide communication between parallel refrigerant passages. 14. A method of manufacturing a flat heat exchanger tube having parallel coolant passages therebetween and consisting of a flat top wall and a flat to white wall to which the cooling fins are attached, and a series of reinforcing walls connected between the top and bottom walls extending along the pipe and spaced each other at a predetermined distance, using a central forming roll finishing mill with a plurality of planetary forming rollers arranged along a portion of the periphery of the central forming roller and spaced circumferentially from each other, the central forming roller or planetary forming rollers having parallel annular narrower annular grooves on opposite sides in the middle of the length, wherein the annular grooves on one of the opposite sides are offset by 1/2 of the groove spacing towards one end of the cylinder relative to the annular grooves on the other side, wherein each of the annular grooves is formed by a narrower depth of the protrusions at a predetermined interval in the grooves and having a height of a smaller lie of the annular grooves, characterized in that a sheet metal strip with a thickness greater than the thickness of the bottom wall produced exchanger tubes on the finishing mill to reduce the thickness of the sheet metal strip to a specified value by the peripheral surface of the central forming roller and the circumferences of the planetary roller rolls to form the flat parts, forming ribs protruding integrally into the grooves of the parts; the ribs slits one of the opposing ribs at a predetermined interval and at least the lateral edges of the strip are bent in the direction and the resulting metal strip having slits in the ribs is bent like a hairpin in the middle of the width of the des but the side edges of the plate are butt-joined to connect alternately vertical ribs on the resulting top wall to the flat portion of the resulting bottom wall and the ribs of the bottom wall to the flat portion of the top wall to form stiffening walls and hexagonal communication openings to ensure communication between parallel, coolant passages. A method of manufacturing a flat heat exchanger tube having, within it, parallel refrigerant passages and consisting of a flat top wall and a flat bottom wall to which cooling fins are attached, and a series of reinforcing walls connected between the top and bottom wall extending along the tube and spaced from each other at a predetermined distance, using a central forming roll finishing mill and a series of planetary forming rollers arranged along a portion of the periphery of the central forming roller and spaced circumferentially from each other, the central forming roller or planetary forming rollers having parallel annular narrower annular grooves on opposite sides in the middle of the length, wherein the annular grooves on one of the opposite sides are offset by 1/2 of the groove spacing towards the one end of the cylinder relative to the annular grooves on the other side; They are formed by a symmetrical predetermined interval in each of the annular grooves less than the depth of the narrower projections in the grooves and having a height by the annular grooves, characterized in that a sheet metal strip having a thickness greater than the bottom wall thickness of the exchanger tube produced on a finishing mill, thereby reducing the thickness of the metal strip to a specified value by the peripheral surface of the central forming roller and the circumferences of the planetary forming rollers to form a flat portion, forming ribs protruding integrally protrusions in each groove. the opposing side edges of the strip are bent toward the projecting ribs and the two resulting metal sheets are joined to each other at the side edges to form side walls, the flat portions of the two metal sheets serving as the top and bottom walls, the downwardly directed fins, connect to the annular fins of the upwardly facing groove of the opposite ribs of the communication openings of the refrigerant passageways. forming reinforcing walls and cut-outs to form hexagonal to ensure communication between parallel Method according to one of Claims 1 to 15, characterized in that a plurality of planetary forming rollers are arranged with respect to the central forming roll, so that the rolling gap decreases in the direction of the advancing metal strip. 17. The method of claims 1 to 15, wherein the metal strip is a brazing sheet having a brazing layer on at least one opposite surface. A method according to claim 8, 9, 10, 11 or 15, wherein the metal sheet is a brazing sheet with a brazing material layer on at least one opposite surface. ova o