JP2761601B2 - Manufacturing method of heat exchanger with plates and fins - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a heat exchanger with plate fins used for, for example, refrigerators and low-temperature showcases.

2. Description of the Related Art In general, this type of heat exchanger is known in which a straight pipe is inserted into a pipe insertion hole of a parallel plate fin and these pipes are connected to each other. The heat exchanger was manufactured by a mechanical expansion method using a mandrel.

Problems to be Solved by the Invention However, in the conventional mechanical expansion method, for example,
As shown in the figure, the plate fins (22) are held in parallel to form a required number of plate fin groups (22A), and these plate fin groups (22A) are inserted into the pipe insertion holes (23). Insert a straight pipe (21), apply lubricating oil to the inner surface of the pipe (21), expand the mandrel (25) by inserting it into the pipe (21), and expand the pipe (21) and plate.・ It is connected to the fin (22)
In the pipe section (21B) without the fin group (22A),
There is a problem that the mandrel (25) does not pass through the center of the pipe (21) due to the so-called uneven thickness, eccentricity and the like of the pipe material, and the pipe is locally distorted and formed.

This is because an annular projection (so-called collar) (24) is generally formed by burring on the periphery of the pipe insertion hole (23) of the plate fin (22). In the pipe portion (21A) where the annular convex portion (24) of the fin (22) exists, the pipe (21) can be prevented from expanding beyond a certain outer diameter, but there is no fin group (22A) In the pipe portion (21B), it is not possible to expect the action of such a fin annular convex portion (24). Therefore, due to the so-called uneven wall thickness and eccentricity of the pipe material, the mandrel (25) is in the
This is because the pipe does not pass through the center of 1) and is distorted and formed.

In the conventional mechanical expansion method, lubricating oil is applied to the inner surface of the pipe (21), and the mandrel (25) is inserted into the pipe (21) to expand the pipe. There is a problem that it is necessary to perform an oil washing step, which is very troublesome.

Furthermore, in order to increase the heat exchange efficiency, a spiral internal ridge (or a spiral groove) is conventionally provided on the inner surface of the pipe material.
However, according to the conventional mechanical pipe expansion method using a mandrel, there is a problem that the ridge of the inner ridge is collapsed by the mandrel at the time of pipe expansion.

An object of the present invention is to solve the above-mentioned problems of the prior art,
In manufacturing a heat exchanger composed of a pipe and a group of plate fins fitted over a part of the entire length of the pipe, even in a pipe portion having no group of plate fins, the pipe is locally distorted. In addition to being able to reliably expand the pipe over the entire length of the pipe, there is no need to perform a troublesome lubricating oil cleaning step, and a spiral internal convex A method of manufacturing a heat exchanger that can produce a high-quality heat exchanger very efficiently without causing the ridges of the internal ridges to collapse even when expanding the pipe material provided with the strip. Is to try to provide.

Means for Solving the Problems In order to achieve the above object, the present invention provides a heat pipe comprising a pipe and a group of parallel plate fins which are fitted over a part of the entire length of the pipe. In manufacturing the exchanger, a lower die having a number of lower pipe holding plates which are arranged in parallel with a fin insertion gap therebetween and have a pipe fitting recess at an upper edge portion, and a fin insertion An upper die having a plurality of upper pipe holding plates having a plurality of upper pipe holding plates having a pipe fitting concave portion at a lower edge portion, with the two pipe holding plates facing each other. Then, a plate fin is inserted into a fin insertion gap at a required portion of the lower die to form a fin group composed of parallel plate fins, and then a fin group having a diameter larger than this is inserted into a pipe insertion hole of the fin group. While inserting a small pipe material, fit this pipe material into the recess of the parallel lower pipe holding plate, lower the upper die, and hold the shape of the pipe material by the upper and lower pipe holding plate over almost the entire length of this Shitsu,
A method for manufacturing a heat exchanger with plate fins, characterized in that the diameter of the pipe material is increased over substantially the entire length by introducing a high-pressure fluid into the inside thereof and the pipe and the plate fins are joined. It is a gist.

According to the method for manufacturing a heat exchanger with plate and fins described above, the pipe material is formed not only by the pipe portion where the plate / fin group exists but also by the pipe holding plates of the upper and lower dies over substantially the entire length of the pipe material. Since the pipe is expanded by high-pressure fluid and the pipe and the plate fin are connected, when the pipe material is expanded,
In the pipe material part where the fin group exists, each plate
The shape of the pipe material portion is retained by the peripheral portion of the pipe insertion hole of the fin and the bottom walls of both concave portions of the upper and lower pipe holding plates, and in the pipe material portion having no fin group,
The shape of the pipe material portion is held by the bottom walls of both concave portions of the upper and lower pipe holding plates, and eventually, the diameter of the pipe material can be uniformly held and expanded over substantially the entire length, and the pipe and the plate fin can be separated. Can be firmly joined. Therefore, even in the pipe portion having no plate fin group, the pipe is not deformed locally and formed at all, and the pipe expansion can be reliably performed over the entire length of the pipe, and high quality heat exchange can be performed. Vessels can be manufactured.

Of course, there is no need to perform a troublesome lubricating oil cleaning step as in the past, and since the pipe is expanded by using a high-pressure fluid, even if a pipe material having a spiral internal ridge on the inner surface is expanded, the internal There is no such thing as the mountain of the ridge is collapsed.

Embodiment Next, an embodiment of the present invention will be described with reference to the drawings.

1 to 5, which show a first embodiment of the present invention, a method for manufacturing a heat exchanger with plate fins according to the present invention includes two pipes (1) and a part of the total length thereof. In manufacturing a heat exchanger consisting of a group (2A) of parallel plate fins (2) fitted in a manner of being fitted over the fins, first, as shown in FIGS. Numerous lower pipe holding plates (11) arranged in parallel with the substrate (10a) with a gap (12a) and having a pair of left and right semicircular recesses (13a) for fitting pipes that open upward at the upper edge. And a pair of right and left pipe fitting semicircles that are arranged in parallel on the substrate (15a) with a fin insertion gap (12b) therebetween and open downward at the lower edge. An upper die (15) provided with a number of upper pipe holding plates (16) having recesses (13b). ) Are arranged such that both pipe holding plates (11) and (16) face each other. A plate fin (2) is inserted into a fin insertion gap (12a) at a required portion of the lower die (10), and a lower half of the pair of left and right pipe insertion holes (3) is a lower pipe holding plate (11). So that they are at the same level as the pair of semicircular recesses (13a)
A required number of fin groups (2A) composed of the fins (2) are formed.

Here, an annular projection (so-called collar) (4) is formed by burring on the periphery of each pipe insertion hole (3) of the plate fin (2), and the lower die (10) is correspondingly formed. A lower step (14a) is formed at one side edge of each semicircular recess (13a) at the upper edge of the lower pipe holding plate (11), and the upper pipe holding plate ( 16) On the same side edge of each semicircular recess (13b) on the upper edge,
Since the upper step (14b) is formed, each annular projection (4) of the plate fin (2) is connected to the lower step (14a) of the lower pipe holding plate (11) of the lower die (10). By fitting the plate fins (2), the lower halves of the pair of pipe insertion holes (3) are at the same level as the semicircular recesses (13a) of the lower pipe holding plate (11). In addition, it can be easily held.

Then, a pipe material (1a) having a smaller diameter is inserted into a pair of left and right pipe insertion holes (3) of the fin group (2A), and each pipe material (1a) is held in parallel in a lower pipe. It is fitted into the semicircular recess (13a) of the plate (11).

Next, as shown in FIG. 3, all the fin groups (2
A) The pipe material (1a) is inserted into each of the two pipe insertion holes (3) of (A), and each pipe material (1a) is inserted into the semicircular recess (13a) of the parallel lower pipe holding plate (11). With the upper die (15) lowered, the lower end of the upper pipe holding plate (16) is brought into contact with the upper end of the lower pipe holding plate (11). ) A pair of left and right circular pipe insertion holes (13) each having a diameter equal to the diameter of each pipe insertion hole (3) of the plate fin (2) and having the pipe material (1a) inserted therein are formed between each other. I do.

Finally, as shown in FIGS. 4 and 5, both ends of the two pipe materials (1a) are closed in this state, and a high-pressure liquid or gas is formed in each pipe material (1a). High pressure fluid is introduced to increase the diameter of each pipe material (1a) over substantially the entire length.

At this time, in the pipe material portion (P) in which the fin group (2A) exists, the peripheral portion of the pipe insertion hole (3) of each plate fin (2) and the annular convex portion (4), and the upper and lower pipe holding plates (2). 11) The shape of the pipe material portion (P) is held by the bottom walls of the semicircular concave portions (13a) and (13b) of (16), that is, the peripheral portion of the circular pipe insertion hole (13), and the fin group is formed. In the pipe material part (Q) without (2A),
Circular pipe insertion holes (1) for upper and lower pipe holding plates (11) and (16)
Since the shape of the pipe material portion (Q) is held by the peripheral portion of 3), the diameter of the pipe material (1a) can be uniformly increased over substantially the entire length, and the pipe (1)
And the plate fins (2) can be firmly connected.

In this way, a product consisting of two pipes (1) and a required number of plate fins (2A) which are fitted over a part of the entire length of the pipes is used for heat exchange as it is. For example, as shown in FIG. 6, the pipe portion (1A) of the two pipes (1) where the fin group (2A) is present may be used as a fin group (2A). By bending the pipe portion (1B) having no pipe in a U-shape as viewed from a plane, the two pipes (1) are meandering as viewed from a plane, and this is used as a heat exchanger in a refrigerator or a low-temperature showcase, for example.

7 to 9 show a second embodiment of the present invention. Here, the difference from the first embodiment is that
First of all, a number of lower pipe holding plates (11) arranged on the substrate (10a) of the lower die (10) with a fin insertion gap (12a) therebetween, and the height of the plate fins (2) is increased. And a pair of left and right U-shaped pipe fitting recesses (13a) which are open upward when viewed from the front, and the bottoms of these pipe fitting recesses (13a) are The lower die (1) is formed on the substrate (15a) of the upper die (15).
A pair of left and right upper pipe holding plates (16) having a width to be fitted in the pipe fitting recess (13a) of (0) is a substrate (15a).
The fin insertion gaps (12b) are arranged in the longitudinal direction of each other, and are opened downward at the lower edges of the respective upper pipe holding plates (16) and are substantially semicircular. Secondly, in order to increase the heat exchange efficiency, spiral inner ridges (5) are provided on the inner surfaces of the two pipe materials (1a). On the point.

Therefore, according to the second embodiment, the lower die (10)
In the required portion of (1), each fin (2) is inserted into the fin insertion gap (12a) deeper than the plate fin (2), and the lower halves of the pair of left and right pipe insertion holes (3) are respectively After dropping down to the same level as the semicircular bottom of the long U-shaped recess (13a), a required number of fin groups (2A) composed of parallel plate fins (2) are formed (FIG. 7). And Fig. 8), the pipe material (1a) is inserted into each of the two pipe insertion holes (3) of all the fin groups (2A), and each pipe material (1a) is connected in parallel to the lower pipe holding plate. When the upper die (15) is lowered while being fitted into the recess (13a) of (11), the upper end of the lower pipe holding plate (11) of the lower die (15) is moved upward.
5) It is abutted against the lower surface of the substrate (15a),
The upper pipe holding plate (16) is fitted into two long U-shaped pipe fitting recesses (13a) opened upward of the lower pipe holding plate (11), and the long U-shaped pipe fitting recess. (13a) and the upper pipe holding plate (1
6) A pair of left and right circular pipe insertion holes (13) into which the pipe material (1a) is inserted are respectively formed by the downwardly open pipe fitting recesses (13b) that are substantially semicircular and open downward. (See FIG. 9). In this state, a high-pressure fluid is introduced into each pipe blank (1a), and the diameter of each pipe blank (1a) is increased over substantially the entire length. ) Can be uniformly increased over substantially the entire length, and the pipe (1) and the plate fin (2) can be firmly connected.

Since the other points of the second embodiment are the same as those of the first embodiment, the same components are denoted by the same reference numerals in the drawings.

In each of the above embodiments, two plate insertion holes (3) are provided in the plate fin (2), and two pipes (1) are inserted. However, the present invention is not limited to this. The method of the present invention is applied to the production of a heat exchanger comprising a plate fin (2) having one or more pipe insertion holes (3) and one or more pipes (1). .

Plate / fin group (2A) for pipe (1)
May be provided at least one.

In each of the above embodiments, after forming the required number of plate / fin groups (2A), the pipe material (1a) is inserted into the pipe insertion holes (3) of the fin group (2A), and then the upper die (15) is formed. ) Is lowered, the lower end of the upper pipe holding plate (16) is abutted against the upper end of the lower pipe holding plate (11), and the shape of the pipe material (1a) is held by the upper and lower pipe holding plates (11) and (16). Although the case of expanding the pipe is shown, after forming the fin group (2A), the upper die (15) is lowered first, and the lower end of the upper pipe holding plate (16) is connected to the lower pipe. After forming a circular pipe insertion hole (13) by abutting against the upper end of the holding plate (11), the pipe material (1a)
Into the pipe insertion hole (3) of the fin group (2A) and the circular pipe insertion hole (1) formed by the upper and lower pipe holding plates (16) and (11).
In some cases, the pipe material (1a) may be expanded while maintaining its shape with the upper and lower pipe holding plates (11) and (16).

In the above embodiment, since the annular projection (4) of each plate fin (2) is supported on the upper surface of the lower step (14a) of the lower pipe holding plate (11), each fin (2) The lower end of the plate fin (2) is apart from the upper surface of the base of the lower die (10).
In some cases, the annular convex portion (4) is not provided. In such a case, the upper and lower dies (10) and (15) do not require the upper and lower steps (14a) and (14b), of course. Each fin (2) is supported with its lower end placed on the upper surface of the base of the lower die (10).

Effect of the Invention The method of manufacturing a heat exchanger with plate fins according to the present invention comprises, as described above, a pipe and a group of parallel plate fins fitted and fitted over a part of the entire length of the pipe. In manufacturing a heat exchanger comprising: a lower die having a plurality of lower pipe holding plates arranged in parallel with a fin insertion gap therebetween and having a pipe fitting recess at an upper edge thereof; An upper die having a number of upper pipe holding plates arranged in parallel with a fin insertion gap and having a pipe fitting concave portion at a lower edge portion,
Arrange both pipe holding plates facing each other,
A plate fin is inserted into a fin insertion gap at a required portion of the lower die to form a fin group composed of parallel plate fins, and a pipe material having a smaller diameter is inserted into a pipe insertion hole of the fin group. While inserting the pipe material into the recesses of the parallel lower pipe holding plate, lowering the upper die, and holding the shape of the pipe material by the upper and lower pipe holding plates over substantially the entire length thereof. By introducing a high-pressure fluid into the interior of the pipe, the diameter of the pipe material is increased over substantially the entire length, and the pipe and the plate fin are joined together. There is no possibility that the pipe will be locally distorted and formed, and it is ensured that the pipe is expanded over the entire length of the pipe. In addition to the need for a troublesome lubricating oil cleaning step, and even when expanding a pipe material with a spiral internal ridge on the inner surface, the mountain of the internal ridge is crushed. Therefore, it is possible to produce a high-quality heat exchanger very efficiently.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 to FIG. 5 are for explaining the steps of the first embodiment of the present invention in order, and FIG. And FIG. 2 is a perspective view showing the state in which the plate fins and the pipe material are set, FIG. 2 is a perspective view of the same, and FIG. FIG. 4 is a partial longitudinal sectional view showing a state in which the pipe is expanded by introducing high-pressure fluid into a pipe material, and FIG. 5 is a perspective view showing the same. FIG. 6 is a perspective view of a heat exchanger formed by bending a pipe portion having no fin group. 7 to 9 are views for sequentially explaining the steps of the second embodiment of the present invention. FIG. 7 is a partial longitudinal sectional view showing a state in which plate fins and a pipe material are set, and FIG. Is the same perspective view,
FIG. 9 is a partial longitudinal sectional view showing a state where the upper die is lowered. FIG. 10 is a partial vertical cross-sectional view showing an implementation step of a conventional heat exchanger manufacturing method. (1) ... pipe, (1a) ... pipe material, (1A) ...
Pipe section with fin group, (1B) ... pipe section without fin group, (2) ... plate fin, (2A)
... fin group, (3) ... pipe insertion hole, (4) ... annular convex part, (5) ... internal convex part, (10) ... lower die,
(11) ... Lower pipe holding plate, (12a) (12b) ... Fin insertion gap, (13a) (13b) ... Pipe fitting recess, (14a) (14b) ... Upper and lower steps, ( 15) Upper die, (16) Upper pipe holding plate.

Claims (1)

(57) [Claims] 1. A pipe (1) and a parallel plate fin (2) fitted over a part of the entire length thereof.
In manufacturing a heat exchanger consisting of a group (2A), a number of fin insertion gaps (12a) are arranged in parallel with each other, and a plurality of pipe insertion recesses (13a) are provided at the upper edge. Lower die (1) with lower pipe holding plate (11)
0) and a pipe fitting recess (13b) which is arranged in parallel with a fin insertion gap (12b) therebetween and has a lower edge portion.
The upper die (15) provided with a number of upper pipe holding plates (16) having the upper and lower pipes (11) and (16) are arranged so that they face each other. The plate fins (2) are inserted into the fin insertion gaps (12a) at the locations, and the parallel plate fins (2) are inserted.
A fin group (2A) is formed, and then a pipe material (1a) having a smaller diameter is inserted into the pipe insertion hole (3) of the fin group (2A), and the pipe material (1a) is inserted. The recesses (13) of the lower pipe holding plate (11)
a) and lower the upper die (15),
The shape of the pipe material (1a) is held by the upper and lower pipe holding plates (11) and (16) over substantially the entire length thereof.
By introducing a high-pressure fluid into the inside of the plate, the diameter of the pipe material (1a) is enlarged substantially over the entire length, and the pipe (1) and the plate fin (2) are connected to each other. Manufacturing method of finned heat exchanger.