JPS6159851B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a cross-finch tube heat exchanger having oblique sides on the fins.

The cross-finch tube heat exchanger has a shape as shown in Figure 1, and the conventional manufacturing method is to stack a large number of fins 1, insert a hairpin pipe 2, and expand the hairpin pipe 2 so that it fits tightly with the fin 1. After fixing, the return pipe 3 is inserted into the hairpin pipe and the connection part 4 is brazed.

An example of a manufacturing method considered to be the most efficient among conventional processing methods will be described below with reference to the drawings.

The fins 1 usually require several hundred pieces, so the most efficient way to manufacture them is to use a high-speed press to make a wide material 5, as shown in the process diagram in Figure 2.
Processing is carried out sequentially at a feed rate of 25 mm, 50 mm, etc., and multiple rows of pipe insertion holes 10 slightly larger than the outer diameter of the hairpin pipe 2 are simultaneously formed through processes such as overhang 6, drawing 7, burring 8, curling 9, etc., and the width cut portion is formed. After cutting to the required width at step 11, the sheets were cut to the required length at length cutting section 12 and stacked. For stacking, as shown in Fig. 3, the fin 1 is placed in the press 13.
Fin suction device 1
4, and when it reaches the required length, cut the fin with the blade 15, weaken the suction force temporarily, drop the fin 12, and cut the hole 10 of the fin with a guide bar 16 having a smaller diameter than the hole diameter of the fin. The sheets are stacked on the stacking jig 17 until the required number is reached while guiding the stacking jig 17. Once the required number of sheets has been accumulated,
After stopping the press and replacing the stacking jig 17,
Start processing again.

According to this method, the mold is large and highly precise, but the width cutting part 11 is changed and the length cutting blade 1 is changed.
By simply changing the operation control counter in step 5, the mold can be used in common even if the fin width and fin length are changed. The stacked fins 1 are assembled by inserting the hairpin pipe 2 into the pipe insertion hole 10 having a diameter larger than that of the hairpin pipe. The assembled fin 1 and pipe 2 are then used by a press-type tube expansion device as shown in FIG. The fins and pipe are fixed after being expanded. Also, at this time, a return pipe insertion part 22 is simultaneously formed in the brazing part 4 shown in FIG. During this tube expansion, in order to prevent the hairpin pipe 2 from buckling due to the compressive force of inserting the tube expansion head 19, the front and side sides of the fins are restrained by box-shaped jigs (not shown). The fins and pipes that have been fixed are number 5.
As shown in the figure, attach the return pipe 3 with the ring solder 23 attached, and stand the hairpin pipe 2 vertically so that the solder can accumulate well in the soldered part 4.
The cross-finch tube heat exchanger is completed by passing it horizontally through the flame 24 of a burner as shown in FIG. 6 to complete the brazing. The example described above is the most efficient method for manufacturing a cross-finch tube heat exchanger, and is the most widely used method in various countries around the world. However, recently there has been a strong trend toward smaller and thinner air conditioning equipment. With this trend, there has been an increasing demand for a cross-finch tube heat exchanger having fins with hypotenuses as shown in FIG. 7, an example of which is shown in FIG.

Such fins cannot be processed by the multi-row simultaneous stacking method shown in FIGS. 2 and 3. To manufacture these fins, the fins shown in FIG. The only way to do this is to push it in and process it one piece at a time.
In this case, as shown in FIG.
7 has to be cut and picked up, and the mold and fin material width become exclusive to that fin.

If the combination shown in Figure 10 is used to improve the material yield, material loss will be reduced, but since the fins will be separated at the cutting line 28 on the oblique side, it will be impossible to take out the fins using a shooter, and as shown in Figure 3. Loading jig 1 with guide bar 16 as shown
7, but since the press is stacked every stroke, the loading jig 17 becomes full within 1 to 2 minutes, and the press is stopped for a long time, which does not improve efficiency. The present invention has been made in order to make it possible to process cross-finch tube heat exchangers with oblique sides on the fins, which have poor efficiency and yield, using the same production equipment as before, without reducing efficiency. It is something that That is, when manufacturing a fin having an oblique side part, the oblique side parts of the fins are joined together to form two fins, and the joined part has the following:
A cut line is made so that only the intersection of the oblique side of the fin and the end surface in the width direction of the fin is connected, and the fins cut in two places are stacked in exactly the same way as the conventional method. Insert the pipes and treat the two parts as one heat exchanger until the final process or at least the process of fixing the fins and pipes is completed, at which time the two parts can be separated from the connection and the two heat exchangers Manufacture. As a result of the above, the final cutting process is added, but considering that the conventional processing line mentioned earlier has all processing parts automated, only the installation and removal of the heat exchanger is done manually. The present invention, which handles two items at the same time, has a great advantage of halving the number of handling steps. To further explain the embodiment below, Fig. 11 shows an example of the shape of the fin that is stacked in two pieces. It is continuous at both ends 30, and when stacked from a press, it is cut at the other short side 31 of the fin and stacked in two pieces.

The pitch of the pipe insertion hole 10 is 25 mm, and each stroke of the press is sent in the direction of the arrow to process one pitch at a time. It is designed to operate once every 10 strokes. The handling of this fin is exactly the same as the conventional processing method except for the notch 29. In this embodiment, 12 fins are machined and stacked in parallel in the width direction. When manufactured using the method shown in Figure 8, the tip of the oblique side of the fin may be deformed during handling, but with this processing method, the pipe 2 can be passed through the stacked fins in the same way as before, and pipe expansion is also possible. Brazing can also be produced without any problems in the same way as before. In this embodiment, each heat exchanger is separated by applying a knife from the outside of the heat exchanger to the connection part 30 as shown by the dotted line 32, and moving the knife parallel to the pipe axis direction by the thickness of the fin stack. It separates in one movement. To provide the score line 29, another independently controllable cut blade is provided in the conventional fin mold between the finished part of the mold and the independently operable cutting blade shown at 15 in FIG. This can be achieved by According to this method, if the shape of the oblique side portion is the same, the length can be easily changed by changing the fins. Further, as in the case of the fin of another embodiment shown in FIG. 12, the oblique side portion may be curved if the shape is symmetrical with respect to the center point 34 of the fin where the score line 33 intersects. Also Fig. 3 15
By making the cutting blade oblique, trapezoidal fins as shown in FIG. 13 can also be made by combining this processing method. As described above, the present invention is a highly economically effective invention that makes it possible to manufacture with high efficiency a cross-finch tube heat exchanger having a fin oblique side portion, which was difficult to achieve using conventional methods.

[Brief explanation of the drawing]

Fig. 1 is an external view and a partial cross-sectional perspective view of a cross-finch tube heat exchanger, Fig. 2 is an external view showing the fin processing process, Fig. 3 is a sectional view showing the stacked part of the fins, and Fig. 4 is a cross-sectional view showing the fin processing process. Fig. 5 is a partial sectional view of the heat exchanger brazing section, Fig. 6 is a conceptual diagram of the brazing work, and Fig. 7 is a partial cross-sectional view of the fin and pipe expansion method. As an example, FIG. 8 is a cross-sectional view of another example of the fin stacking method, FIG. 9 is a plan view showing the cutting order of the fins using the method of FIG. 8, and FIG. 10 is a plan view showing the cutting order of the fins in another example. FIG. 11 is a plan view of the fin in an intermediate step of the embodiment of the present invention, and FIG. 12 is a plan view of the fin of another embodiment of the present invention in the intermediate step.
FIG. 3 is a plan view of a fin according to another embodiment of the present invention. 1...Fin, 2...Hairpin pipe, 3...
Return pipe, 4... Brazing part, 5... Fin material, 6... Overhanging part, 7... Squeezing part, 8... Burring part, 9... Curling part, 10... Pipe insertion hole, 11... Width Cutting section, 12...Length cutting section, 13...Press lower part, 14...Suction device, 1
5... Cutting blade, 16... Guide bar, 17... Loader, 18... Rod, 19... Pipe expansion head, 2
0... Heat exchanger end surface, 21... Heat exchanger side surface, 2
2... Retan pipe insertion part, 23... Ring wax, 24... Burner flame, 25... Cutting blade, 26
...Chute guide, 27...Material notch, 28
... Hypotenuse cutting line, 29 ... Hypotenuse cutting line, 30
... Connection portion, 31 ... Cut end surface, 32 ... Separation line, 33 ... Curved oblique side portion, 34 ... Target point.

Claims (1)

[Scope of Claims] 1. When producing a fin having an oblique side part, the oblique side parts of the fins are joined together to form two fins, and the joining part includes a part where the oblique side part of the fin intersects with the end face in the width direction of the fin. Cut a cut line so that the chisel connects, stack the fins cut in two places, insert the pipe, and cut the fins in two places until the final process or at least the process of fixing the fins and the pipe is completed. A method for manufacturing a cross-finch tube heat exchanger, characterized in that the heat exchanger is handled as one heat exchanger, and then separated from the connected portion to separate into two heat exchangers. 2. The method of manufacturing a cross-finch tube heat exchanger according to claim 1, wherein the score line of the fin hypotenuse is a curved line symmetrical with respect to the center point of the score line. 3. One fin is composed of multiple repeating patterns, and the pattern is formed with each stroke of the press, and the processing of the cutting line on the oblique side and the cutting of every second fin operate independently when necessary. A method of manufacturing a cross-finch tube heat exchanger according to claim 1 or 2, which is carried out by a tool part. 4. A method of manufacturing a cross-finch tube heat exchanger according to claims 1 to 4, wherein the connection is separated by moving a knife in a direction parallel to the pipe axis.