JPH0380571B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a cross-finch tube heat exchanger in which a large number of fins are arranged in parallel and a plurality of heat transfer tubes are passed through and in close contact with these fins. The present invention relates to a method for manufacturing exchanger fins.

[Background of the invention]

Cross-finch tube heat exchangers are widely used as evaporators or air-cooled condensers in heat exchangers for air conditioners. The cross-finch tube heat exchanger generally has a large number of thin plate fins made of aluminum or the like and having a suitable area arranged side by side with a fin pitch of several millimeters, and a plurality of transmission lines such as copper pipes are attached to the side-by-side fins. A heat transfer pipe line in the heat exchanger is created by passing through the heat pipe, expanding the entire penetrating part to bring the fins into close contact with each other, and connecting a U-shaped return pipe to the open end of the heat transfer pipe that has passed through the parallel fins. is formed in a meandering shape.

Cold water, hot water, refrigerant, etc. are passed through the heat transfer tube, while air, etc. is passed between a large number of parallel fins outside the tube, and both fluids exchange heat with each other via the tube wall and fins of the heat transfer tube. . Therefore, what is required of this type of heat exchanger is the same heat transfer performance as well as thinning of the fin material in order to reduce costs. In order to improve heat transfer performance, for example, as disclosed in US Pat. No. 3,397,741, a large number of cut and raised louvers are formed.
In this way, the fin shape that aims to improve the performance of a single fin has an extremely complex shape compared to the conventional simple flat fin, which inevitably requires a manufacturing mold with high precision and is expensive. becomes. Also,
As fin materials become thinner, highly accurate processing equipment is required to machine holes in the collar portion of the fins into which heat exchanger tubes are inserted. U.S. Pat. No. 2,977,918 discloses a method of manufacturing a collar portion of a fin in which a tapered flange is first formed and then a right-angled flange is formed by a mold having a female die and a tool arranged above and below. In addition, as disclosed in U.S. Pat. There are also methods that correct the position in the center.

Processing equipment that requires high precision in this way requires more processing steps and larger molds, which requires a larger press area, necessitating a press machine with excessive capacity, and the equipment is becoming increasingly oversized. They end up becoming larger and more expensive.

[Purpose of the invention]

An object of the present invention is to provide an improved method for manufacturing heat exchanger fins to obtain high performance.

[Summary of the invention]

In order to achieve the above object, the present invention provides a cross-finch tube type in which a plurality of fins formed by molding a louver slit portion and a plurality of collar portions are arranged side by side, and a heat transfer tube is inserted into each collar portion and brought into close contact with the fins. In a method for manufacturing heat exchanger fins for a heat exchanger,
The louver slit part is formed into a louver slit after forming a flat plate material into a wave and forming a mountain wave, and each collar part is stretch formed at the same time as the mountain wave forming, and then drawn at the same time as the louver slit forming, and following the drawing forming. After edge trimming to product dimensions, pierce burring molding,
It is characterized by a structure in which ironing forming and curling forming are performed in this order. When molding a louver slit with a complex shape, if you immediately mold it from a flat plate material to the final shape, there is a limit to the elongation of the material, so it is difficult to obtain a sufficient height when molding a partial rising part. do not have. The present invention firstly
In consideration of this point, before carrying out louver slit forming, wave forming is performed as a pre-process, and then corrugation processing is performed in a mountain wave shape having obtuse angle portions. This is done by shaping the entire fin shape before cutting the final shape of the louver slit without giving any elongation to the material, and in the final forming of the louver slit, cut the fin with a sufficient rising height. It allows the pieces to be shaped.

The tool for wave forming involves arranging multiple round rods of the same diameter in a row, and drawing a flat material between the upper and lower round rods to form the material. It can be molded, and the mold is extremely simple and inexpensive to manufacture compared to one-piece molds.

The louver slit portion is formed by cutting the strip and forming the peaks of the strip at the same time in one stroke of the press. This has the feature that no misalignment occurs between the slit and the chevron portion, and the number of steps can be reduced to reduce the size of the mold and the space required for the step. Furthermore, the overall number of steps is reduced by performing the drawing process of the collar part at the same time as the louver slit part is formed. This is effective in reducing the size of the mold and is useful in reducing the processing time for the entire fin.

In order to obtain a high-performance heat exchanger, the shape of the louver slit is an important point. In the present invention, the louver slit portion is formed as follows. In other words, after completing the previous process mentioned above, a corrugation with a non-stretching mountain wave shape is processed, and between the temporary heat exchanger tubes in the tube row direction (holes in the collar part have not yet been drilled at this point. Holes will be drilled after that). A large number of incisions are made in the fin portion of the fins (only the drawing process for the purpose of forming the fins is formed), and the incision strips are formed into small mountain shapes. The cut strips are then raised into bridge shapes. Then, a small mountain shape will be formed on the slope where the large mountain waveform corrugation has been processed.
The height positions of the edges of adjacent small chevron portions are formed to be shifted from each other. These molding processes are performed by one-stroke press working in which an upper die and a lower die are moved up and down. Therefore, the shapes of the upper mold and the lower mold become complex shapes with high precision.

The molding process for the collar of the hole into which the heat transfer tube is inserted is as follows:
It consists of five forming processes: stretching, drawing, piercing barring, ironing, and curling. The stretch forming is performed at the same time as the corrugation of the louver slit portion at the same time, and the drawing forming is performed at the same time as the final forming of the louver slit, as described above.
What is important here is that the above-described forming process of the louver slit portion is completed before starting the piercing burring process of the collar portion, which will be performed from now on. This is to prevent a large amount of chips and punched pieces that are cut out during the piercing burring and ironing processes from getting mixed in during the process of forming the complicated cut and raised strips. Another important reason is that
This is because if the louver slit portion is processed after the collar portion is formed, there is a risk that the hole in the collar portion, which has been finished with high accuracy, may be deformed.

Fin pitches are sometimes required to have a narrow pitch or a wide pitch. As one means of satisfying this requirement, by changing the thickness of the adjusting liner provided under the drawing punch in advance, it is possible to obtain a raised collar portion of any height. The mold consisting of a louver slit die, punch, etc. for forming the louver slit is made into an independent mold for each row of louver slits, thereby facilitating maintenance of the partial rows. By arranging the molds in rows in this way, even when manufacturing heat exchangers with different numbers of rows, it is of course possible to remove and process only the molds of rows that do not require processing. The present application is
It has a row slit blade attachment mechanism that allows changing the fin pattern (number of fin rows) without removing the slit blade from the mold.

In the piercing burring process of the collar part, a pilot hole is bored in the center of the drawing part and at the same time, a tapered burring process is first performed. It is extremely important to process the material into a tapered shape at this stage. That is, the piercing burring process and the ironing process are made into separate processes, and the reference inner diameter is made the same, so that a new burring process is not performed in the ironing process. At this time, by tapering the diameter of the burring punch, it is easy to separate the material from the punch. The reference inner diameter referred to here is the maximum diameter of the tapered part (d ₀ ).
and this maximum diameter is the given finished diameter (d ₁ )
The nominal diameter can be the same diameter as (d ₀ = d ₁ ) or a slightly larger diameter (d ₀ > d ₁ ).In the ironing process of the collar part, the ironing punch should always face the center of the hole. The body of the ironing punch is formed by a swinging shank part, and has a freely centripetal mechanism that automatically points toward the center of the ironing die.The shank part is easy to swing and is movable. It is preferable to use a flexible material. Examples of the flexible material include piano wire for springs.
In this way, the positional relationship between the ironing die and the ironing punch is automatically centered, so that errors in the mold can be absorbed, and there is no need for the precision of mold manufacturing to be very high. Therefore, there is also the advantage that mold manufacturing costs are reduced. In addition, since the inner diameter of the burring die during the taper burring process is the same as the inner diameter of the ironing die for the predetermined finish (the maximum diameter of the tapered part and the predetermined finish diameter are the same),
The same die can be used, reducing the number of parts types.
This results in a significant reduction in mold manufacturing costs.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described based on the drawings. FIG. 1 is a side view of a mold for pressing the fins of a cross-finch tube heat exchanger according to an embodiment of the present invention. It consists of a movable upper mold 20 which is fixed to a section, and inside this mold the thin plate material 1 is moved in the direction of the arrow 2 in each process A to A.
After passing through J, it becomes Huynh.

In the process, step A is waving of the louver slit portion, step B is wavy processing of the louver slit portion and bulge processing of the collar portion, and step C is:
Perform louver slit forming and drawing of the collar. Process D is edge trimming processing, Process E is taper piercing burring processing of the collar part,
In step F, the collar portion is ironed, and in step G, curling is performed. In step H, the pitch feed mechanism of step I separates the rows and pitches the entire sheet, and the sheet is sent to the final step J for shearing processing. The feature of this process is that the taper pierce burring process is performed after the process of the louver slit part is completed.

FIG. 2 is a partial plan view of the fins of a cross-finch tube heat exchanger showing an embodiment of the present invention. It is shown in Figure 4. A collar portion 6 for inserting a large number of heat exchanger tubes is provided on the flat fin board 5.
A large number of incisions 7 are made in the intermediate space between this collar part and another adjacent collar part, and this incision strip 8 is bent into a mountain wave shape at the center of the width direction (in the figure, it has a ridge line 9). (obtuse angle), and the notched strips at appropriate positions are raised up almost parallel to the fin substrate in a bridge shape, and the heights of the respective chevron strips 10', 10'', 10 are changed, and the heights of the adjacent chevron strips are adjusted. Edge 11', 11'', 1
Provide a shift in 1. (The above-mentioned cross-sectional PP section is hereinafter collectively referred to as the louver slit section.) Next, in the collar section 6, as shown in Fig. 4, the gap between the fins arranged in parallel, that is, the fin pitch, is managed by the l dimension. The fins are formed for the purpose of reducing the contact thermal resistance between the fins and the heat transfer tube. As described above, the fin according to the manufacturing method of the present invention is formed of a large number of louver slit portions and a large number of collar portions, and the overall fin shape is formed into a mountain wave shape 12. Next, some features included in the mold shown in FIG. 1 for manufacturing the fins will be explained with reference to the drawings.

First, regarding the processing method for the louver slit part, conventionally molding this type of shape usually requires three or more steps: 1) cutting, 2) bending, and 3) bridge-like forming, but this method requires a larger mold. Therefore, a large press machine is required. However, since the material is a thin plate, it does not require a large processing capacity, resulting in a waste of equipment costs. As described above, a mold for producing fins with a complicated shape as shown in FIG. 2 necessarily requires multiple steps. The present invention solves this problem. A method for processing a louver slit portion is provided.

The features of the louver slit processing method of the present invention are as follows:
The louver slit portion is simultaneously processed in the step shown by symbol C in FIG. 1 by one vertical movement of the press. That is, the material is preformed into a mountain wave shape using a louver slit die 13 (equipped in the fixed lower mold 10) and a louver slit punch 14 (equipped in the movable upper mold 20) as shown in FIG. 5A. 1" can be simultaneously cut, bent, and formed into a bridge shape as shown in FIG.
15 shown in Figures B and C is the cutting edge portion. This advantage is that the mold size (process space) is smaller.

2. Parts processing costs can be saved (cheap).

3. Obtain a good fin shape without misalignment between the notch and the chevron.

Another feature is that the louver slit part is preformed into a wave shape 1' and then a wave shape 1'' from the material 1, as shown in Fig. 6, in the pre-processing process where the louver slit part is completed in one process.The actual product is If the fin shape shown in Figure 2 is one row, the width of the material exceeds approximately 500 mm because dozens of rows are pressed at the same time.
The number of peaks indicated by diagonal lines in the figure is approximately 50. Therefore, if material 1 is processed from a flat plate state to the shape of a louver slit part at one time, a large elongation deformation will be applied to the center part of the approximately 500 mm width, and cracks will occur in the fins. This prevents elongation and deformation. Also, even if the material 1 is formed into a 1" mountain waveform in one step, cracks will occur in the same way. However, this is possible if the bending radius at the top of the mountain waveform is made large, but then the louver slit part is When the material is molded at a certain temperature and released from the mold, it does not form a sharp shape as shown in Fig. 5D due to the influence of spring back.Therefore, as shown in Fig. A wave shape ₁ ' having a cross-sectional area A ₀ approximately equal to the cross-sectional area A 1 shown by diagonal lines in FIG. 1 is processed in the step shown by symbol C in FIG. The structure of this process is as shown in Fig. 7, and the wave length L ₀ at one location shown in Fig. 6 and the peak wave length L ₁ at one location are the same dimension (in this case, the inevitable The diameter of the round bar-shaped tools 16 and 16' (height is H ₀ < H ₁ ) is determined. In other words, the shape of the tools 16 and 16' is such that the material 1 has the least elongation deformation and the mold This structure allows the material to be drawn in toward the center (in the direction of arrow 17) and processed into a wave shape. Another feature is that the tool 16 and the tool 16' can be made into the same part, which reduces the number of parts, reduces mold costs, and is less expensive than when machining one piece. As mentioned above, if the material is drawn in smoothly and processed into a wave shape and then formed into a 1" mountain waveform, the material will not crack even if the apex of the bending blade is not rounded, resulting in a sharp apex shape 18. Mountain waveform 1 ” can be formed. As mentioned above, this shape gives good results in the next step of processing the louver slit portion.

Generally used corrugated shapes are formed by immediately forming a flat plate material once, relying on the elongation of the material, and are thus limited to a rising height _H1 that does not exceed the elongation limit. However, according to the present invention, there is no elongation of the material in the pre-treatment process compared to the conventional method, so that the rising height of the cut and raised strips can be maintained sufficiently.

Next, as mentioned above, from the material 1, a wave shape 1' is formed.
Next, a mold structure that can process a preformed waveform of 1" into a louver slit shape in one press process will be explained in detail based on FIG. 8. FIG. 8A shows a state in which the mold is released; B is a sectional view showing a state in which the louver slit portion has been processed, and a side view seen from the direction of arrow 19 is shown in FIG. 8C.The first feature of this structure is that the louver slit die 13 The supporting method for the ribbon punch 14 is a unit type structure for each row (in an example in which several dozen rows of fins shown in FIG. 2 are pressed at the same time), that is, (1) Louvus. The punch 14 is the punch holder 2
Bolt part 2 for fixing the louver strip pump 4 to 0
1 and a special bolt 21 that has a positioning part 21'' to the upper die plate 22.
Must be fixed to 0.

(2) A die 23 for preliminary drawing (details will be described later) of the collar portion 6 shown in FIG. 2 is housed in the punch holder 20 with a structure shown in the drawing that can be moved by a spring 24.

(3) The louver slit die 13 is fixed to the die holder 25 with the special bolt 21.

(4) A punch 26 for preliminary drawing (details will be described later) and a stripper pin 27 of the collar portion 6 shown in FIG.

(5) The punch holder 20 in which the parts (1) and (2) above are assembled and the die holder 25 in which the parts (3) and (4) above are assembled form one unit and are connected to the upper mold plate 22 and the lower part by bolts 29. The structure of the louver slit part processing process fixed to the mold plate 30.

(6) The stripper pin 27 has both the role of separating the 7-7 from the cutting blades 13 and 14 after louver slit processing and the role of sending the workpiece 1'' by sliding it on the top surface of the pin 27.The above effects are as follows: (a) For each row Since it is a unit type, maintenance is easy (parts can be easily replaced even if parts are damaged). Mold manufacturing costs are extremely high because special processing equipment and enormous processing time are required.With this method, parts can be divided into smaller parts, eliminating the need for unreasonable processing and significantly reducing mold costs. I can figure it out.

(c) When manufacturing a conventional one-piece stripper plate, the area of the louver slit part is larger than the fin area as in the embodiment of the present invention, and when this louver slit part is processed in one process, the one-piece stripper plate The structure of the stripper plate becomes weak. However, the pin-type stripper according to the present invention has a built-in holder, so
As shown in Figure A, the workpiece slides on the upper surface of the stripper pins 27 standing in a row, and this function can be fully performed.

As described above, the processing of the louver slit portion has various characteristics, and when the processing of the louver slit portion is completed, the louver slit die 13 and the louver slit punch 14 are in the state shown in FIG. 5D. As is clear from this figure, the fin material is completely restrained within the cutting edge, so there are no foreign objects, especially symbol E (hole punch) symbol F in Figure 1.
Chips generated during processes such as ironing and burring,
It is clear that if vented gas etc. gets mixed in and accumulates, it will damage the cutting blade. In order to avoid this danger, the features of the present invention include these chips,
The above-mentioned louver slitting process is placed before the collar part forming process, compared to the process that generates scraps. Next, a method of fabricating the collar portion 6 having the cross-sectional shape shown in FIG. 4 will be described. Further, FIG. 9 shows the collar part molding process. First, Figure 9A is the first
The step indicated by symbol B indicates that the overhanging portion 31 is formed in the same step as the step of forming the waveform 1'' in FIG. 6.

Next, FIG. 9B shows that in the process indicated by symbol C in FIG. 1, the constricted portion 32 is formed in the same step as the step of forming the louver slit portion as shown in FIG. Next, FIG. 9C shows that in the process indicated by symbol E in FIG. 1, a pilot hole is bored in the center of the constricted portion 32 and a tapered burring portion 33 is formed at the same time.
Next, FIG. 9D shows that in the process of symbol F in FIG.
It is shown that the vertical cylindrical portion 34 is ironed to a predetermined inner diameter d by a rolling means equipped with a free centripetal mechanism. Next, FIG. 9E shows that in the process indicated by symbol G in FIG. 1, curling is performed so that the collar portion 6 has a predetermined fin height l. The collar portion 6 is molded by the above molding process, and various features included in this process will be described below.

The purpose of the processing shown in FIGS. 9A and 9B is to adjust the reduction amount, that is, the amount by which the material is reduced in the direction of the arrow 35 (adjustment of h ₁ and h ₂ dimensions), thereby increasing the height l ₀ dimension of the vertical cylindrical portion 34. The goal is to control. This is because if a collar portion with a low l dimension is curled while the l ₀ dimension remains high, cracks will occur in the flange portion 36 . Therefore, when molding a collar portion with a particularly low dimension l, the steps shown in FIGS. 9A and 9B may be omitted by lowering the punch completely. This control method will be explained with reference to FIG. 8. Although the drawing punch 26 shown in this figure is of the step B in FIG. 9, it can be considered that the punch 26 in the step A of FIG. 9 has almost the same structure. The drawing punch 26 is held by a height adjusting liner 37 in the structure shown in the figure. Therefore, in order to adjust the heights h ₁ and h ₂ shown in Fig. 9A and B, the height dimension
It turns out that all you have to do is replace _h3 with a different adjustment liner. Further, in order to omit steps A and B in FIG. 9, it is sufficient to simply remove the adjustment liner 32. This allows the l dimensions of various collar portions 6 to be changed using the same mold with less setup change time.

Regarding the characteristics of the processes in Figure 9 C, D, and E, 10th
This will be explained with reference to FIGS. 11 and 12.

The feature of this molding of _the collar _part 6 is that in the pre-process shown in FIG _. A burring portion 33 having a shape is formed. The inner diameter d ₀ in this tapered shape is the reference diameter of the tapered burring, and in some cases, the nominal diameter of this reference diameter is called a diameter that is somewhat larger than d ₀ in consideration of the R section of section 33a. Sometimes. Next, the vertical cylindrical part 34 having a predetermined inner diameter d ₁ is completed with the remaining burring, and at the same time is rolled and ironed by a rolling means equipped with a free centripetal means, and then curled to obtain the desired height l of the fin collar part 6. The purpose is to mold it into. FIG. 10 shows the structure of the tapered burring portion 33 during the processing process. The upper surface 39 of the stripper plate 38 is the cut surface 41 of the fixed die 40.
The movable die 42 held by the movable upper die 20 and the movable die 42 contained therein are attached to the lower die 10 set in the shape of FIG. The punch 43 for drilling a pilot hole descends, punches a pilot hole, and drops the punched waste 44. At the same time, a tapered burring part 45 is formed by a tapered burring punch part 45 and a movable die 42 that fits it. . This burring processing method is called inverted burring, and has a structure that has been generally applied to fin press types.
The feature is that 5 is tapered. The tapered shape allows the inner diameter dimension d ₀ to be tightly controlled, and compared to the conventional straight shape, the burring part can be removed from the punch with extremely small force without deforming the shape of the burring part after processing.

Next, the tapered burring part 33 formed into the above-mentioned shape is moved to the process indicated by symbol _F in FIG. As shown in the figure, it is rolled by the ironing punch 47 and ironing die 48 to a predetermined raised dimension l ₀ .

The details of this ironing process will be explained with reference to FIG. 12. FIG. 12A shows the state before the laddering process, and FIG. 12B shows the state after the laddering process is completed. 52 is a die holder, and 53 is a punch holder. When the tapered burring part 33 is sent onto the stripper plate 49, the pilot part of the pin 50, which has both a pilot function and a knockout function and is movable by a spring 51, tapers the center of the ironing die 48. The inner diameter of the tapered portion (d ₂ shown in FIG. 9C) of the shaped burring portion is set. Then the first
In the process of lowering the upper mold to the state shown in Fig. 2B, the ironing die 48, ironing punch 47, and shank 51 supporting them complete the remaining burring, and at the same time, the ironing process is carried out by the rolling means equipped with a free centripetal means. Let's do it.

Now, in this ironing process, since the material 1 is rolled and becomes extremely thin, it is necessary to form the thickness of the intermediate part of the fin collar to be uniform and without any deviation. 47 must be kept concentric. However, even if the molds are made concentrically when manufacturing, the steel materials such as the ironing punch holder 53 that supports the die holder and ironing punch may deform due to seasonal temperature changes in the place where the mold is used or temperature rises due to ironing. It is difficult to maintain concentricity even if measures such as passing cooling water are taken. Moreover, it is extremely difficult to manufacture concentrically. In order to solve this problem, a flexible centripetal means is applied to the ladder punch in the burring mold of the present invention. The shank 51 to which the ironing punch 47 of FIG. 12 is attached is made of a flexible material, such as piano wire for a spring, and is tilted freely toward the center of the ironing die 48 based on the ironing punch holder 53. , it is a freely centripetal mechanism. By this means, errors in the positional relationship between the ironing die 48 and the ironing punch 47 can be absorbed, the accuracy during mold manufacturing can be made somewhat easier, and the mold manufacturing cost can be reduced. In addition, since the ironing punch 47 is formed in a spherical shape, the contact surface with the material is in line contact, and the material is less likely to adhere to the surface of the ironing punch 47 than with surface contact such as a cylindrical punch. effective.

The shank portion 51 is made of an ironing punch 47 and a pin 5 made of a highly hard material such as carbide.
Connected by 4. In addition, the shank part is made of a flexible material that is integrally machined with the fixed part of the punch holder 53, and the part that swings toward the center of the ironing die is machined to be as thin as possible to withstand the ironing force without buckling. Also, this part is made as long as possible.

Next, the features included in the molding process shown in FIGS. 9C to D will be described. As mentioned above, the feature of this process is that in the next step of the tapered burring step, the remaining burring is completed and at the same time, the inner wall of the burring portion is ironed to form a predetermined vertical cylindrical shape. This advantage is due to the tapered shape, which makes it easier to enter the ironing die 48 in the next step, and the fact that it is the best shape for smooth ironing, as shown in FIG. 11. Furthermore, by limiting d ₀ ≧ b ₁ , the burring die 42 and the 11th die shown in FIG.
Since the ironing die 48 shown in the figure can use the same parts (with the same inner diameter), the number of the same parts can be doubled at once (the number of types of parts can be reduced), and the mold manufacturing cost can be reduced. Figure 13 shows the details of the row slit blade section, and is characterized by the fact that the row slit blade can be replaced by sliding it inside the mold without removing the row slit blade attached to the upper mold of the find die. That is.

The row slit upper blade 61 has an adjusting bolt 67
By connecting with and rotating the adjuster bolt 67, the row slit upper blade 61 moves up and down the inner surface 65a of the row slit slide plate 65, and engages with the row slit lower blade 64. 66 is a holding bolt. This adjustment bolt 67 can be manually operated, but it can also be easily automated using an electric drive or a cylinder.

This makes it easy to replace the row slit blades when changing the fin pattern, making it possible to significantly reduce the number of man-hours.

The features of the present invention are summarized as follows.

1. The mold size (process space) becomes smaller.

2. A good fin shape with no misalignment between the louver slit cut and the chevron shape can be obtained.

3. Wave-like preforming allows formation of good shapes and high wave heights.

4. Since the louver slitting process is a unit type, maintenance is easy as even if parts are damaged, parts can be replaced.

5. Since the louver slitting process is a unit type, parts can be divided into smaller parts and simple parts shapes can be created, so there is no need for excessive machining and mold costs can be reduced.

6. The louver slit process is installed in a place where it is difficult for chips, vented gas, etc. to get mixed in, so there is little risk of mold damage.

7. Since the burring punch part is tapered, the burring part can be removed from the punch 4 with extremely small stripper force without deforming the shape of the burring part after processing.

8. In the ironing process of the collar part, a flexible centripetal mechanism is adopted, so concentricity can be maintained appropriately and the thickness of the fin collar can be made uniform. In addition, the accuracy of mold manufacturing can be made rough.

9. Changing the fin pattern The slitting blade can be easily replaced and the number of man-hours can be greatly reduced.

〔Effect of the invention〕

Since the present invention is configured as described above, it is possible to obtain an improved method for manufacturing a louver strip fin for a heat exchanger to obtain high performance.

[Brief explanation of drawings]

FIG. 1 is an overall schematic diagram of the fin processing apparatus, and shows the process order of the processing parts. Figure 2 is a plan view of the processed fin, Figure 3 is
PP arrow cross section in Figure 2, Figure 4 is Q in Figure 2.
-Q arrow sectional view, FIG. 5 is a diagram showing the processing situation of the louver strip fin part, FIG. 6 is a diagram showing the preforming method of the material, FIG. 7 is a diagram showing the wave-shaped processing situation, Figure 8 is a sectional view and side view of the louver slit processing device, Figure 9 is a diagram showing the collar part forming process, Figure 10 is a diagram of the tapered burring situation, and Figure 11 is an enlarged view of the ironing process. , FIG. 12 shows an overall diagram of the ironing process. FIG. 13 is a detailed view of the row slit blade portion. 10... Fixed lower mold, 20... Movable upper mold, 1...
Thin plate material, 5...Fin board, 6...Color part,
7... Cut, 8... Cut strip, 9... Ridge line, 1
0, 10, 10... chevron strip, 11, 11, 11
... Edge, 12 ... Mountain waveform, 13 ... Louva slit die, 14 ... Louva slit punch, 1
6, 16...Tool, 25...Die holder, 26...
...Preliminary drawing punch, 27... Stripper pin, 28... Spring, 32... Drawing part, 33
... Tapered bur ring, 34 ... Vertical cylindrical part, 36 ... Flange part, 37 ... Adjustment liner,
47... Shigoki punch, 48... Shigoki die, 5
2... Die holder, 53... Punch holder, 61
... row slit upper blade, 64 ... row slit lower blade.

Claims (1)

[Scope of Claims] 1. Heat exchanger of a cross-finch tube heat exchanger in which a plurality of fins formed by molding a louver slit portion and a plurality of collar portions are arranged side by side, and a heat transfer tube is inserted into each collar portion and brought into close contact with the fins. In the dexter fin manufacturing method, the louver slit portion is formed into a louver slit after forming a flat plate material into a wave and forming a mountain wave, and each collar portion is formed by stretch forming at the same time as the mountain wave forming, and then at the same time as the louver slit forming. 1. A method for manufacturing heat exchanger fins, which comprises drawing, followed by edge trimming to product dimensions, followed by piercing burring, ironing, and curling. 2 Louver slit forming involves making multiple cuts in the fins between heat transfer tubes adjacent in the tube row direction, forming the cut strips into a mountain shape, raising the cut strips into a bridge shape, and forming the cut strips into a bridge shape. 2. The method of manufacturing a heat exchanger fin according to claim 1, wherein the molding is performed by shifting the height positions of adjacent edges of the pieces. 3. The method of manufacturing fins for a heat exchanger according to claim 1, wherein the collar portion is formed so that the height of the fin collar can be changed by ironing. 4. The method for producing fins for a heat exchanger according to claim 2, wherein in the louver slit forming, the cutting, bending, and bridge-like forming of the cut strips are performed by one vertical movement of the press. 5 Wave forming is characterized in that a plurality of round bar-shaped tools with the same diameter are arranged in a staggered manner, and a flat plate material is drawn between the tools to form a wave. The method for manufacturing heat exchanger fins according to item 1. 6 Louver slit molding is performed using a mold consisting of a louver slit die and a louver slit punch.
2. The method of manufacturing heat exchanger fins according to claim 1, wherein the fins are processed in units of tube rows. 7. The method for manufacturing heat exchanger fins according to claim 1, wherein the pierce burring molding involves punching a pilot hole in the center of the constricted portion of the collar portion and simultaneously performing burring into a tapered shape. 8 In ironing, a spherical ironing punch with the upper and lower parts cut off, which is provided at the tip of the shank, is automatically guided to the center of the ironing die by a rolling means equipped with a free centripetal mechanism having a swinging shank. 2. The method of manufacturing heat exchanger fins according to claim 1, wherein the processing is carried out by moving the fins from below to above. 9. The heat exchanger according to claim 3, wherein the drawing is performed by replacing adjustment liners of different thickness between the lower end surface of the drawing punch and the mold body. Fin manufacturing method. 10 Pierce burring molding is characterized in that the maximum diameter (d ₀ ) of the tapered burring portion satisfies d ₀ ≧ _{d 1 in} relation to a predetermined finished diameter (d 1 ). The method for manufacturing heat exchanger fins according to item 7.