JPH07318295A - Plastic heat exchanger and manufacture thereof - Google Patents

Abstract

PURPOSE:To integrally mold a plastic heat exchanger for air conditioning by a plastic sheet. CONSTITUTION:Plastic sheets (1) 4, (2) 5 are superposed, advanced in a direction 10, and cutouts 7 are formed by a plurality of cutting edges 1b provided at a rotary unit 1a of a rotating cutter 1. The cutter 1 is heated to thermally cut the sheets 4, 5 to form the cutouts 7, and to simultaneously fusion-bond the cut edges to form a plurality of heat transfer tubes 8 to become heat transfer passages. Simultaneously, both the ends 4a, 4b, 5a, 5b of the sheets 4, 5 are thermally cut by side cutters 2, 3, their cut edges are fusion-bonded to form headers 9 at both ends. Accordingly, a heat transfer tube body 6 is integrally molded by the two sheets 4, 5, thereby easily manufacturing a heat exchanger.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air, gas or liquid-refrigerant plastic heat exchanger applicable to air conditioning and a method for manufacturing the same.

[0002]

6 to 9 are schematic perspective views of a conventional heat exchanger. As a conventional air-refrigerant heat exchanger, as shown in FIG. 6, a plurality of aluminum fins 20 are fixed to a copper tube 21, a refrigerant 22 is caused to flow in the copper tube 21, and heat of the air 23 and the refrigerant 22 is transferred. There is a fin and tube heat exchanger that performs the exchange. Further, as the liquid-refrigerant heat exchanger, as shown in FIG. 7, a plate 30 made of a metal such as copper or stainless steel forms a passage for the liquid (1) 31 and the liquid (2) 32 to form the liquid ( 1) 31 and the liquid (2) 32, a plate type heat exchanger for exchanging heat, and as shown in FIG.
Pass the tube 41 through the shell 40, and from one side, liquid (1)
There is a shell-and-tube heat exchanger that causes 43 to flow out of the header 42, inflows the liquid (2) 44 into the shell 40, and exchanges heat between the liquid (1) 43 and the liquid (2) 44. .

Further, in the fields of medical and food machines, as shown in FIG. 9, a plurality of plastic tubes 51 are bundled and inserted into a shell 50, and an end 55 is adhered to a header 52 to form a liquid (1). 53 is poured, and the liquid (2) is put in the shell 50.
There is also a shell-and-tube heat exchanger that flows 54 to exchange heat between liquid (1) 53 and liquid (2) 54.

[0004]

Since the conventional fin & tube heat exchanger shown in FIG. 6, plate type heat exchanger shown in FIG. 7 and shell & tube heat exchanger shown in FIG. 8 are all made of metal. There was a problem that it was heavy and easily corroded. Therefore, as shown in FIG. 9, there is a shell-and-tube heat exchanger that uses a plastic tube 51 as a heat transfer tube, but the plastic tube 51 and the header 52 are bonded by using an adhesive or the like. Therefore, if the adhesion is insufficient, there is a problem such as liquid leakage from that portion, and it is necessary to take measures.

Further, since plastic has a lower tensile strength and a lower thermal conductivity than metal, the heat transfer tube is a small diameter tube in order to ensure sufficient pressure resistance and heat exchange capacity. There was a need. However, if the heat transfer tube has a small diameter, it is difficult to bond the structure with the header and the heat transfer tube,
In addition, there is a problem that the possibility of leakage increases due to an increase in the adhesion area.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention superimposes two or more plastic sheets and heat-cuts them, and at the same time, welds their cut edges by heat to form a plurality of heat-transfers. To provide a plastic heat exchanger in which a header group is formed by forming a group of passages and welding the periphery of the sheet, further heat cutting the sheet using a rotary cutter and a side cutter, and welding to make the plastic A method of manufacturing the heat exchanger is also provided.

That is, as the invention of (1), a plurality of plastic sheets are superposed on each other, and the periphery thereof is welded to leave header portions on both sides, and at the same time, a predetermined space is provided between both header portions on both sides. A heat exchanger made of plastic, comprising a plurality of heat transfer passage groups formed by welding.

As the invention of (2), there is also provided a plastic heat exchanger in which a plurality of heat transfer passage groups of the invention of (1) are formed in parallel with each other at equal intervals.

Further, as the invention of (3), a plurality of plastic sheets are superposed and supplied, and while cutting both sides in the supply direction with heated side cutters, the cut ends are welded, and the space between the side cutters is With a heated rotary cutter provided at right angles to the sheet feeding direction and having a blade with a predetermined width and pitch on the outer periphery, the cut portion is welded while cutting the central portion of the plastic sheet at predetermined pitches. Also provided is a method for manufacturing a plastic heat exchanger characterized by the following.

[0010]

According to the present invention, the heat transfer passage group formed by heat cutting and welding and the header portion can be integrally molded from a plastic sheet by the above-mentioned means. There is no concern about leakage of the refrigerant from the bonded portion of the thin tube, the reliability is improved, and the heat resistance of the sheet is reduced because the heat transfer passage group is formed by the plastic sheet. Furthermore, by reducing the diameter of the heat transfer passage group, the heat transfer area on the air side can be increased and the pressure resistance of the inside refrigerant can be increased.

Further, in the invention of (2), since the heat transfer passage groups are arranged in parallel and at equal intervals, the above-described operation is achieved and the heat transfer passage groups can be easily processed. It is arranged uniformly.

Further, in the invention of (3), a method is adopted in which the rotary cutter which heats the heat transfer passage group, and the header portion is heat-cut at the same time by a pair of side cutters and the cut ends thereof are welded. Therefore, the plastic heat exchanger can be integrally molded from a plurality of sheets, and unlike the conventional case, it is possible to easily manufacture a reliable heat exchanger without adhering a thin tube with an adhesive.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. 1 is a perspective view of a plastic heat exchanger manufacturing apparatus according to an embodiment of the present invention and a heat exchanger immediately after manufacturing, FIG. 2 is a perspective view of a cutter for heat cutting used in this embodiment, and FIG. FIG. 4 is a perspective view of a side cutter for heat cutting similarly used in this embodiment.

In these drawings, reference numeral 1 denotes a rotary cutter for heat cutting, in which a plurality of blades 1b are provided in the radial direction on the circumference of a cylindrical rotating body 1a. (Shown with 6 blades in FIG. 1) 2 and 3 are a pair of side cutters for heat cutting, which rotate on the left and right of the cutter 1 either coaxially with the rotor 1a or independently provided on a shaft 1a. . Reference numeral 4 is an upper plastic sheet (1), 5 is a lower plastic sheet (2), and 6 is a heat transfer tube main body after two sheets 4, 5 are formed. Reference numeral 7 denotes a cut portion which is cut by the blade 1a of the cutter 1 and the cut portion is welded, and 8 constitutes a heat transfer passage group, and is a heat transfer tube formed by welding the cut end of the cut portion. . Reference numeral 9 is a header formed by cutting and welding the plastic sheets (1) 4 and (2) 5 together by the side cutters 2 and 3 on both sides.

With such a configuration, the two plastic sheets 4 and 5 enter from the advancing direction 10 and are cut by the plurality of blades 1a of the rotating cutter 1 to form a plurality of cut portions 7. The blade 1a of the cutter 1 is heated at a temperature sufficient to melt the plastic sheet, and the cut portions of the sheets (1) and (2) are welded to each other by this heat at the same time as cutting, and the heat transfer tube 8 is formed. To be done. At the same time, the left and right ends of the plastic sheets 4 and 5 are heated by the heated side cutters 2 and 3 similarly to the cutter 1, and end portions 4a and 4b,
The headers 9 are formed by cutting the cut portions 5a and 5b and welding the cut portions by the heat.

FIG. 2 is a perspective view of an embodiment of a cutter 1 having eight blades, in which eight blades 1 are evenly arranged around the rotating body 1a.
b is fixed, and the plastic sheet is cut at the tip of the blade 1b. In this case, the pitch of the heat transfer tubes 7 formed is equal. By changing the blade width P1 of the cutter and the pitch P2 on the circumference and arranging the blade, the diameter and pitch of the heat transfer tube and the gap between the tubes can be selected to desired dimensions. (6 in FIG.
Although illustrated with a single blade, in FIG. 2, the pitch P2 is equally divided into eight, and eight blades are illustrated. FIG. 3 is a perspective view of the side cutters 2 and 3 in which the plastic sheet is cut by a blade on the circumference by rotating around the shaft 2a. In addition, the shaft 2 of the side cutters 2 and 3
The a and 3a may be coaxial with the rotating body 1a of the cutter 1 or may be independent shafts.

FIG. 4 is a view showing a manufacturing process of a heat transfer tube according to an embodiment of the present invention, and the cutter is shown as four blades 1b for convenience of explanation. (A) shows a state in which the blade A of the cutter 1 is rotating on the outer periphery of the rotating body 1a and is approaching the plastic sheets 4 and 5. (B) shows a process in which the blade A rotates and comes into contact with the plastic sheet 4 to cause the deformation B. In (c), the rotation of the blade A progresses, the plastic sheets 4 and 5 are cut together, and
The state where the cut portion is welded to form the heat transfer tube 7 having a space inside is shown.

FIG. 5 is an explanatory view showing the process of accommodating the sheet of the heat exchanger having the formed heat transfer tubes in the case. (A) shows a heat transfer tube main body 6 having a heat transfer tube 8 manufactured by a cutter 1 and a side cutter 2, and (b) shows a heat transfer tube main body 6a obtained by forming header inlets and outlets 11 and 12 from the main body 6. 6C shows a state 6c in which the main body 6a is folded into a plurality of units, and FIG. 6D shows a state in which the unitary heat exchanger 6c is housed in the case 15.

By making the above case an open structure or a closed structure, it can be used as a heat exchanger for all fluids.

In the above, the case of the two plastic sheets 4 and 5 has been exemplified, but when the number of sheets is three or more, it is also possible to provide a heat exchanger for a plurality of fluids of three or more fluids. .

According to this embodiment, since the heat exchanger is made of plastic, it is lightweight, and the heat transfer tube 8 and the header 9 are molded at once by the cutter 1 and the side cutter 2 without using an adhesive. Therefore, the manufacturing cost can be reduced. Further, because of this, problems such as defective adhesion as in the prior art do not occur and reliability is improved. Therefore, the thermal resistance of the plastic sheet is reduced, and further, by reducing the diameter of the heat transfer tube 8, the heat transfer area on the air side can be increased and the pressure resistance of the refrigerant inside the tube can be increased.

[0022]

As described above in detail, in the present invention, two or more plastic sheets are superposed on each other, and the header portion welded on the periphery of the sheets and both sides are welded on the central portion. A heat exchanger having a plurality of heat transfer passage groups is produced, and such a heat exchanger is manufactured by heat cutting and welding a plastic sheet with a rotary cutter having a plurality of blades on the outer periphery and a side cutter. Since the method is adopted, the following effects are obtained.

(1) Since the heat exchangers are all made of plastic, they are lightweight, and the heat transfer tube passage portion and the header portion can be molded at one time, and the manufacturing cost can be reduced.

(2) Since the heat exchanger is manufactured by heat cutting with a rotary cutter and a side cutter and forming the cut portion by welding, compared with the conventional method of adhering a thin plastic tube with an adhesive, Integral molding becomes possible,
Bonding work and defects due to poor bonding are eliminated, and the reliability of the product is improved.

[Brief description of drawings]

FIG. 1 is a perspective view of a plastic heat exchanger manufacturing apparatus and a heat exchanger according to an embodiment of the present invention.

FIG. 2 is a perspective view of a cutter for manufacturing a plastic heat exchanger according to an embodiment of the present invention.

FIG. 3 is a perspective view of a side cutter for manufacturing a plastic heat exchanger according to an embodiment of the present invention.

4A and 4B are explanatory views of a manufacturing process of a plastic heat exchanger according to an embodiment of the present invention, where FIG. 4A is a state immediately before heat transfer tube molding, and FIG. (C)
Shows the state after forming the heat transfer tube.

FIG. 5 is an explanatory view of a process of housing a heat transfer tube body of a plastic heat exchanger according to an embodiment of the present invention in a case, (a) shows a molded state of the body, and (b) shows a molded transfer. The state of the heat pipe main body, (c) shows the state of the molded main body bent, and (d) shows the state of the folded unit housed in the case.

FIG. 6 is a perspective view of a conventional fin & tube heat exchanger.

FIG. 7 is a perspective view of a conventional plate heat exchanger.

FIG. 8 is a perspective view of a conventional shell and tube heat exchanger.

FIG. 9 is a perspective view of another conventional shell and tube heat exchanger.

[Explanation of symbols]

 1 Cutter 2 Side Cutter 3 Side Cutter 4 Plastic Sheet (1) 5 Plastic Sheet (2) 6 Heat Transfer Tube Body 7 Notch 8 Heat Transfer Tube 15 Case

Claims (3)

[Claims] 1. A plurality of plastic sheets are superposed on each other, and the periphery thereof is welded to leave header portions on both sides, and the header portions are arranged at a predetermined interval, and both sides are welded. A plastic heat exchanger comprising a plurality of formed heat transfer passage groups. 2. The plastic heat exchanger according to claim 1, wherein the plurality of heat transfer passage groups are formed in parallel with each other at equal intervals. 3. A plurality of plastic sheets are superposed and supplied, and while cutting the both sides in the supply direction with heated side cutters, the cut edges are welded and the sheet is cut between the side cutters at right angles to the sheet supply direction. The cut portion is welded while the central portion of the plastic sheet is cut at a predetermined pitch by a heated rotary cutter having a blade having a predetermined width and pitch on the outer periphery. Manufacturing method of plastic heat exchanger.