Unit cooler and manufacturing method of the same

Abstract

To provide a unit cooler which has a heat exchanger having high cooling efficiency and can perform defrosting efficiently.SOLUTION: A unit cooler has: a housing through which air passes; a fan device including a fan for introducing air into the housing; and a heat exchanger disposed in the housing. The heat exchanger has: a plurality of fins each including first holes and second holes; cooling pipes penetrating through the first holes of the fins; and defrost pipes penetrating through the second holes of the fins. An inner diameter of the first hole is smaller than a maximum outer diameter of the cooling pipe. The unit cooler has a first burring part extending from an inner edge of the first hole in an extension direction of the cooling pipe. An inner periphery of the first burring part adheres to an outer periphery of the cooling pipe over an entire periphery.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a unit cooler and a method for manufacturing the same. [Background technology]

[0002] A unit cooler that supplies cold air to a large refrigerator, freezer, etc. is configured to cool the outside air taken in from outside the housing through a heat exchanger inside the housing, and then supply the cold air into the refrigerator or freezer (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-154785 Summary of the Invention [Problem to be solved by the invention]

[0004] There is a demand for a unit cooler that has a heat exchanger with high cooling efficiency and can prevent frost from forming on the heat exchanger fins, etc. Therefore, the relationship between the fins, cooling piping, and defrost pipe in the heat exchanger is important.

[0005] The present invention has been made in view of the above-mentioned problems, and has an object to provide a unit cooler having a heat exchanger with high cooling efficiency and capable of efficiently performing defrosting, and a method for manufacturing the same. [Means for solving the problem]

[0006] In order to achieve the above object, the unit cooler according to the present invention comprises: a housing through which air passes; a fan device including a fan that introduces air into the housing; a heat exchanger disposed within the housing; the heat exchanger includes a plurality of fins each having a plurality of insertion holes, and a plurality of pipes passing through the insertion holes of the fins; The inner periphery of the insertion hole is in close contact with the outer periphery of the pipe over the entire circumference.

[0007] The unit cooler according to the present invention comprises: a housing through which air passes; a fan device including a fan that introduces air into the housing; a heat exchanger disposed within the housing; the heat exchanger includes a plurality of fins each having a plurality of first holes and a plurality of second holes, a plurality of cooling pipes passing through the first holes of the fins, and a plurality of defrost pipes passing through the second holes of the fins; an inner diameter of the first hole is smaller than a maximum outer diameter of the cooling pipe; a first burring portion extending from an inner edge of the first hole in an extending direction of the cooling pipe; The inner periphery of the first burring portion is in close contact with the outer periphery of the cooling pipe over the entire periphery. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a unit cooler that has a heat exchanger with high cooling efficiency and that can suppress the formation of frost on the fins of the heat exchanger, and a method for manufacturing the same. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a vertical cross-sectional view showing an outline of a unit cooler according to this embodiment. [Figure 2] FIG. 2 is a perspective view showing a part of the heat exchanger. [Figure 3] FIG. 3 is a view of the fin before assembly, viewed from a direction perpendicular to the surface. [Figure 4] FIG. 4 is an enlarged perspective view of the fin shown in FIG. [Figure 5] FIG. 5 is a perspective view showing a part of the fin immediately before assembly. [Figure 6] FIG. 6 is a cross-sectional view showing the process of expanding the cooling pipe. [Figure 7] FIG. 7 is a diagram showing a model of a part of the surface of a fin to explain the passage opening ratio. [Figure 8] FIG. 8 is a diagram showing a model of a part of the surface of a fin to explain the surface transmission coefficient. [Figure 9] FIG. 9 is a diagram showing a fin as a comparative example. [Figure 10] FIG. 10 is a diagram showing a fin according to an embodiment. [Figure 11] FIG. 11 is a cross-sectional view showing a process of expanding a pipe according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a vertical cross-sectional view showing an outline of a unit cooler 10 according to this embodiment.

[0011] 1, a unit cooler 10 of this embodiment includes a housing 12 that forms a closed space therein, a heat exchanger 20 disposed inside the housing 12, an intake hood 14 attached to the housing 12, and a fan unit 30 attached to the housing 12. However, the intake hood 14 does not necessarily have to be provided.

[0012] The housing 12 has, for example, a rectangular parallelepiped shape and is composed of a bottom surface 12c, a ceiling surface 12d that faces the bottom surface 12c and is spaced apart vertically, a back surface 12a to which the intake hood 14 is attached, a front surface 12b that is spaced apart horizontally from the back surface 12a and to which the fan unit 30 is attached, and a pair of side surfaces 12e (only one of which is shown in Figure 1) that are spaced apart and connected to the ends of the bottom surface 12c, the ceiling surface 12d, the back surface 12a, and the front surface 12b, respectively.

[0013] In this embodiment, the housing 12 is installed on the floor B of a large refrigerator, freezer, etc. (not shown), for example, via a base 16, but it may also be suspended from the ceiling of the refrigerator or freezer using appropriate means.

[0014] The heat exchanger 20 has a function of exchanging heat with the air (outside air) by directly contacting the air drawn in through the intake hood 14. The heat exchanger 20 is also provided with a defrosting mechanism for removing frost and other materials adhering to the heat exchanger 20 during defrosting operation.

[0015] The heat exchanger 20 is placed on the bottom surface 12c of the housing 12 via a pedestal 26. A drain pan (not shown) that discharges water resulting from melted frost during defrosting operation is provided on the bottom surface 12c of the housing 12. With this configuration, water resulting from melted frost during defrosting operation is discharged to the outside.

[0016] The fan device 30 has an exhaust duct 32 attached to the front surface 12b of the housing 12, and a blower motor 34 attached to the exhaust duct 32 via a stay 36.

[0017] During cooling operation, the blower motor 34 rotates the fan 34a while the cooled refrigerant flows through the cooling piping of the heat exchanger 20, which will be described later. Then, outside air is drawn into the housing 12 in the direction of arrow A1 from the lower opening 14a of the intake hood 14. Furthermore, the air that has been cooled by passing through the heat exchanger 20 in the direction of arrow A3 (horizontal direction) is discharged through the exhaust duct 32 in the direction of arrow A2, and the cool air is supplied inside the refrigerator, freezer, or the like, thereby lowering the temperature inside the refrigerator or freezer to below zero degrees.

[0018] During defrosting, the cooling operation is stopped, and warm brine at 15 to 35°C or a high-temperature, high-pressure refrigerant (hot gas) generated downstream of the compressor is passed through the defrosting piping described below to melt frost and other matter adhering to the heat exchanger 20. The high-temperature, high-pressure refrigerant (hot gas) is, for example, at 40 to 70°C, and can be passed through the defrosting piping by switching the flow path of the refrigeration cycle. Also, instead of defrosting piping, a wire- or rod-shaped heat-generating member (hereafter referred to as a heater) can be used. A heater is, for example, a rod-shaped ceramic supporting a heating element such as a nichrome wire, covered with a metal tube. Note that the term "defrosting pipe" is used to refer to both defrosting piping and heaters.

[0019] FIG. 2 is a perspective view showing a portion of heat exchanger 20. Heat exchanger 20 has a large number of fins 21 (only three are shown in FIG. 2), cooling pipes 22 made of tempered stainless steel or copper, and defrosting pipes 23. Fins 21, formed from sheet metal, have surfaces along the air flow direction A3 (FIG. 1) and are arranged in parallel at a pitch of, for example, 4 to 10 mm. Cooling pipe 22 has a bent shape that penetrates all of fins 21 in the direction in which fins 21 are arranged, exits from the last fin 21 in the direction of arrangement, makes a U-turn to re-enter from the same fin 21, penetrates all of fins 21 again in the direction of arrangement of fins 21, and makes another U-turn, repeating this process multiple times.

[0020] When the defrost piping 23 is a piping for warm brine, it penetrates all of the fins 21 in the direction in which the fins 21 are arranged, exits the last fin 21 in the direction of arrangement, makes a U-turn to re-enter the same fin 21, penetrates all of the fins 21 again in the direction in which the fins 21 are arranged, and makes another U-turn, repeating this process multiple times, so that the defrost piping has a bent shape. On the other hand, when the defrost piping 23 is a piping for warm brine, multiple straight pipes penetrate the fins 21. In either case, the defrost piping 23 is straight in the portion shown in FIG. 2.

[0021] In this embodiment, the cooling pipe 22 uses a 3 / 8 inch pipe, and the defrosting pipe uses a larger diameter 4 / 8 inch pipe.

[0022] FIG. 3 shows a single fin 21 before assembly, viewed from a direction perpendicular to the surface (along the pipe penetration direction), after punching but before the spacers 21c are raised. Each fin 21 has a common shape and includes a flat base 21p, a first hole 21a through which the cooling pipe 22 passes, a second hole 21b through which the defrosting pipe 23 passes, and a generally U-shaped spacer 21c. For example, the fin 21 shown in FIG. 3 can be formed by punching an aluminum sheet using a die. The first holes 21a are arranged in rows parallel to each other along the flow direction of air passing through the fin 21 (the left-right direction in FIG. 3), i.e., they are not arranged in a staggered pattern.

[0023] Fig. 4 is an enlarged perspective view of fin 21 shown in Fig. 2. When first hole 21a is punched, the vicinity of the inner edge of first hole 21a is plastically deformed so as to be stretched in the punching direction, and a thin-walled, cylindrical first burring portion 21d is formed contiguous to base portion 21p. Similarly, when second hole 21b is punched, the inner edge of second hole 21b is plastically deformed so as to be stretched in the punching direction, and a thin-walled, cylindrical second burring portion 21e is formed contiguous to base portion 21p.

[0024] A spacer 21c is disposed adjacent to the first hole 21a or the second hole 21b. As shown in FIG. 4, the spacer 21c is cut and bent from a base 21p and stands at approximately 90 degrees relative to the base 21p. The spacer 21c is connected to a pair of legs 21f, 21f and a beam 21g connecting one end of the legs 21f, and the other end of the legs 21f, 21f is connected to the base 21p. When the spacer 21c is viewed from the front (as shown in FIG. 3), the width of the base side of the spacer 21c is smaller than the width of the tip side. In other words, the spacer 21c has a shape that becomes wider toward the tip. Note that the spacer 21c does not have to be U-shaped, but may be a single plate having a trapezoidal shape (a so-called dovetail shape).

[0025] Each of the legs 21f has a rib 21h extending longitudinally in the center. The rib 21h increases the rigidity of the legs 21f, making them less susceptible to buckling. For example, before bending the spacer 21c, a mold is used to form elongated protrusions corresponding to the ribs 21h on the surface of the base 21p, and then the spacer 21c is bent. This forms a bulge at the base of the legs 21f, preventing the legs 21f from collapsing. The length of the spacer 21c is longer than the first burring portion 21d and the second burring portion 21e.

[0026] After the spacers 21c are cut and raised, corresponding, roughly U-shaped holes 21k are formed in the base 21p. Support portions 21m, which are surrounded by the holes 21k and are flush with the surface of the base 21p, are formed between the bases of the legs 21f. The length of the support portions 21m is preferably at least 1 / 2 and at most 3 / 4 of the length of the legs 21f. A portion of the fin 21 formed as described above is shown in FIG. 5.

[0027] As shown in FIG. 2, when the fins 21 are stacked, the edges of the beam portions 21g of the spacers 21c abut against the base portions 21p, allowing the spacing (pitch) between the fins 21 to be set to a constant value of 4 to 10 mm. This makes it difficult for frost to adhere to the fins 21. That is, the spacing (pitch) between the fins 21 is set by the height of the spacers 21c (the distance from one end of the leg portions 21f, 21f to the base portions 21p). Even if the first burring portions 21d and the second burring portions 21e formed by a mold are abutted against adjacent fins 21, it is difficult to ensure a fin pitch of 4 to 10 mm. In particular, when the fins 21 are stacked, the support portions 21m abut against the beam portions 21g of the spacers 21c of the adjacent fins 21, thereby preventing the spacers 21c from falling off into the holes 21k.

[0028] The cut and raised surface of spacer 21c is aligned along the air flow direction (arrow A3 direction) shown in Figure 4, and when air flows in the direction of arrow A3, some of the air passes between legs 21f, 21f. Furthermore, since legs 21f, 21f also have ribs 21h, 21h, turbulence is more likely to occur in the air passing between fins 21, thereby improving cooling efficiency.

[0029] Next, the arrangement of the first holes 21a, the second holes 21b, and the spacers 21c will be described. In Fig. 3, the vertical (up-down) arrangement of the first holes 21a is referred to as a column, and the horizontal (horizontal) arrangement is referred to as a row.

[0030] Specifically, the first holes 21a are arranged at equal intervals in the vertical direction at a pitch VP and at equal intervals in the horizontal direction at a pitch HP. That is, the first holes 21a are aligned in both the horizontal and vertical directions. It is preferable that VP>HP.

[0031] The second hole 21b is not formed between the first hole 21a in the Nth column and the first hole 21a in the (N+1)th column counting from the upstream side in the air flow direction (direction of arrow A3), nor between the first hole 21a in the Lth row counting from the top and the first hole 21a in the (L+1)th row, but is formed between the first hole 21a in the (L+2)th row and the first hole 21a in the (L+3)th row, and is arranged equidistant (centrally) from the surrounding first holes 21a.

[0032] In addition, second holes 21b are formed similarly between first holes 21a in the (N+2)th column and first holes 21a in the (N+3)th column counting from the upstream side in the air flow direction, and between first holes 21a in the Lth row counting from the top and first holes 21a in the (L+1)th row, but are not formed between first holes 21a in the (L+2)th row and first holes 21a in the (L+3)th row.

[0033] Therefore, in an area where 16 first holes 21a are arranged, three second holes 21b are arranged. The second holes 21b are arranged in two staggered rows between four rows of first holes 21a. In other words, when the fin 21 is viewed along the arrangement direction of the fin 21 (the direction in which the piping penetrates), there are areas where one second hole 21b is arranged between four first holes 21a and areas where no second holes 21b are arranged between four first holes 21a. The area where one second hole 21b is arranged between four first holes 21a refers to a quadrangle with vertices at the centers of the four first holes 21a and where a second hole 21b is formed within the quadrangle. The area where no second holes 21b are arranged between four first holes 21a refers to a quadrangle with vertices at the centers of the four first holes 21a and where no second holes 21b are formed within the quadrangle.

[0034] By arranging the second holes 21b in a staggered pattern with fewer second holes 21b than first holes 21a, as shown in FIG. 2, when cooling pipes 22 are arranged in the first holes 21a and defrosting pipes 23 are installed in the second holes 21b, the air flow between the fins 21 is made to meander, thereby improving cooling efficiency and preventing overheating during defrosting, thereby suppressing the generation of mist. Since the rows of first holes 21a (cooling pipes 22) aligned along the direction of air flow through the fins 21 are arranged parallel to each other, this, combined with the relatively wide vertical spacing between the cooling pipes 22, ensures a smooth flow of air passing between the fins 21. This prevents frost blockage even at low temperatures, enabling continuous operation, suppressing internal temperature rise, and saving energy. For example, air that has entered the heat exchanger along the air flow direction (the direction of arrow A3) flows through the gap between the cooling pipe 22 and the defrosting pipe 23, or the gap between adjacent cooling pipes 22. Because the air cannot pass straight through the gap between the cooling pipes 22, the cooling efficiency can be improved.

[0035] In the Nth column of the first holes 21a, the spacer 21c is formed between the first hole 21a in the Lth row counting from the top and the first hole 21a in the (L+1)th row, but is not formed between the first hole 21a in the (L+1)th row and the first hole 21a in the (L+2)th row.

[0036] Furthermore, in the (N+1)th column of the first holes 21a, the spacer 21c is not formed between the first hole 21a in the Lth row counting from the top and the first hole 21a in the (L+1)th row, and is not formed between the first hole 21a in the (L+1)th row and the first hole 21a in the (L+2)th row.

[0037] Therefore, the spacers 21c are arranged in two staggered rows between the two rows of the first holes 21a. By arranging the spacers 21c in a staggered manner in this manner, an increase in air resistance can be suppressed and the cooling efficiency can be improved by making the air flow uniform. In this embodiment, the spacers 21c disposed in the gaps of the cooling pipes 22 that serve as air passages are arranged with the longitudinal direction of the plate material aligned with the air flow direction, thereby suppressing an increase in air resistance.

[0038] When attaching the cooling pipe 22 to the first hole 21a, the pipe is expanded. Specifically, as shown in FIG. 6, the cooling pipe 22 is inserted into the first hole 21a of the fin 21, and with one end closed, a high-pressure fluid (such as water) is pumped from the other end from a pump PP to pressurize the inside. This causes the cooling pipe 22 to undergo plastic deformation so as to expand. As a result, the outer periphery of the cooling pipe 22 is in close contact with the inner periphery of the first hole 21a and the first burring portion 21d over the entire circumference, thereby improving cooling efficiency. After the pipe is expanded, the fluid is discharged.

[0039] At this time, because expansion is suppressed by the first holes 21a, the outer diameter φa of the cooling pipe 22 inside the first holes 21a (equal to the inner diameter of the first holes 21a) becomes smaller than the outer diameter φb of the cooling pipe 22 elsewhere, that is, a circumferential groove is formed on the outer periphery of the cooling pipe 22. This makes it possible to suppress axial displacement of the fins 21 relative to the cooling pipe 22.

[0040] When attaching defrosting pipe 23, through which warm brine or hot gas passes, to second hole 21b, pipe expansion is performed in the same manner as described above, so that the outer periphery of defrosting pipe 23 is in close contact with the inner periphery of second hole 21b and second burring portion 21e over the entire circumference, allowing the heat of the warm brine or hot gas to be efficiently transferred to fin 21. On the other hand, when attaching a wire-shaped or rod-shaped heater to second hole 21b, pipe expansion is not performed, and the heater is simply inserted into second hole 21b. This is because the heater is heated to a high temperature, and so can sufficiently heat fin 21 even if the heater and second burring portion 21e are not in close contact over the entire circumference.

[0041] (passage aperture ratio) Next, the opening ratio of the fin will be described. Fig. 7 is a diagram showing a model of a portion of the surface of the fin 21, as seen in the direction in which the cooling pipes penetrate. In Fig. 7 (and Fig. 8, which will be described later), the vertical direction of the fin is the X direction, and the width direction of the fin is the Y direction. The opening ratio of the fin is determined in the region where four first holes 21a surround one second hole 21b. Spacers are omitted.

[0042] Here, we consider region α, where second hole 21b is formed in the center of first hole 21a(1) in the (N+2)th column and Lth row, first hole 21a(2) in the (N+3)th column and Lth row, first hole 21a(3) in the (N+2)th column and (L+1)th row, and first hole 21a(4) in the (N+3)th column and (L+1)th row.

[0043] The upper edge of region α in the X direction extends in the Y direction at a position midway between first hole 21a(1) in the (N+2)th column and Lth row and first hole 21a (not shown) in the (N+2)th column and (L-1)th row, and the lower edge of region α in the X direction extends in the Y direction at a position midway between first hole 21a(3) in the (N+2)th column and (L+1)th row and first hole 21a (not shown) in the (N+2)th column and (L+2)th row.

[0044] Furthermore, the left edge of region α in the Y direction extends in the X direction at a midpoint between first hole 21a(1) in the (N+2)th column and row L and first hole 21a (not shown) in the (N+1)th column and row L, and the right edge of region α in the Y direction extends in the X direction at a midpoint between first hole 21a(2) in the (N+3)th column and row L and first hole 21a (not shown) in the (N+4)th column and row L.

[0045] Here, when the distance between the first hole 21a and the second hole 21b in the X direction is A, the distance from the first hole 21a to the end of the X direction of the region α is B, and the length of the region α in the X direction is C, the through opening ratio β is expressed by the following equation (1). β = ((A×2) + (B×2)) / C×100 (1)

[0046] The larger the opening ratio β, the less likely the gaps in the fins that form the air flow path will be blocked by frost and the less susceptible to the effects of frost, making it excellent for use at low temperatures.However, this limits the diameters of the cooling pipes and defrosting pipes.

[0047] (Transmission coefficient) Next, the surface transmission coefficient of the fin will be explained. Fig. 8 is a diagram showing a model of a part of the surface of the fin 21, as seen in the direction in which the cooling pipes penetrate. Here, the region γ around the first hole 21a in the Nth column and Lth row will be considered.

[0048] The upper edge of region γ in the X direction extends in the Y direction at a midpoint between first hole 21a in the Nth column, Lth row and first hole 21a in the Nth column, (L-1)th row (not shown), and the lower edge of region γ in the X direction extends in the Y direction at a midpoint between first hole 21a in the Nth column, Lth row and first hole 21a in the Nth column, (L+1)th row (not shown).

[0049] The left edge of region γ in the Y direction extends in the Y direction at a midpoint between the first hole 21a in the Nth column and Lth row and the first hole 21a in the (N-1)th column and Lth row (not shown), and the right edge of region γ in the Y direction extends in the Y direction at a midpoint between the first hole 21a in the Nth column and Lth row and the first hole 21a in the (N+1)th column and Lth row (not shown).

[0050] Here, when the length of region γ in the X direction is A' (m), the length of region γ in the Y direction is B' (m), and the inner diameter of first hole 21a is φC' (m), the surface transmission coefficient δ is expressed by the following equation (2). δ=(((A'×B')-π(C') 2 / 4)×2) / 1000 (2)

[0051] The smaller the surface transfer coefficient δ, the better the heat transfer efficiency between the cooling pipes and the fins, and while a large cooling efficiency can be obtained with a small heat transfer area, the diameter of the cooling pipes is limited.

[0052] (Comparative Example) Fig. 9 is a diagram showing a fin as a comparative example. In the fin of Fig. 9, the first holes 21a are arranged in a staggered pattern, and no second holes are formed. The pitch of the first holes 21a in the X direction is 22 mm, the pitch of the first holes 21a in the Y direction is 25 mm, and the inner diameter of the first holes 21a is φ9.88 mm. In this case, the through opening ratio β of the comparative example is 22.2%, and the surface transmission coefficient δ is 0.975 / m.

[0053] (Example) Fig. 10 is a diagram showing a fin according to an embodiment. The fin shown in Fig. 10 has first holes 21a and second holes 21b, similar to the fin shown in Fig. 3, with the X-direction pitch of the first holes 21a being 25mm, the Y-direction pitch of the first holes 21a being 30mm, and the inner diameter of the first holes 21a being φ9.8mm. In this case, the passing opening ratio β of the embodiment is 47.3%, and the surface transmission coefficient δ is 1.358 / m.

[0054] 11 is a cross-sectional view showing a process of expanding a pipe according to another embodiment. In this embodiment, the configuration other than the fins 21' is the same as in the above-described embodiment, so a duplicated description will be omitted. In addition, the fins 21' are the same as in the above-described embodiment except that a first burring portion is not formed in the first hole (insertion hole) 21a, so a duplicated description will be omitted.

[0055] As shown in Fig. 11, cooling pipes 22 are inserted into first holes 21a of fins 21', and with one end closed, high-pressure fluid (such as water) is pumped from the other end from pump PP to pressurize the interior. This causes plastic deformation so that the cooling pipes 22 expand. This expansion brings the entire outer periphery of the cooling pipes 22 into close contact with the inner periphery of the first holes 21a, thereby improving cooling efficiency. After expansion, the fluid is discharged.

[0056] The second hole of the fin may be an insertion hole without forming a second burring portion, and may be expanded after the defrosting pipe is inserted in the same manner as described above.

[0057] The present invention is not limited to the above-described embodiments. Any of the components of the above-described embodiments can be modified within the scope of the present invention. Furthermore, any of the components can be added or omitted from the above-described embodiments. For example, the refrigerant of the present invention may be a fluorocarbon-based refrigerant or CO2.

[0058] This specification includes the disclosure of the following inventions. (First aspect) a housing through which air passes; a fan device including a fan that introduces air into the housing; a heat exchanger disposed within the housing; the heat exchanger includes a plurality of fins each having a plurality of insertion holes, and a plurality of pipes passing through the insertion holes of the fins; The inner periphery of the insertion hole is in close contact with the outer periphery of the pipe over the entire circumference. A unit cooler characterized by:

[0059] (Second aspect) a housing through which air passes; a fan device including a fan that introduces air into the housing; a heat exchanger disposed within the housing; the heat exchanger includes a plurality of fins each having a plurality of first holes and a plurality of second holes, a plurality of cooling pipes passing through the first holes of the fins, and a plurality of defrost pipes passing through the second holes of the fins; an inner diameter of the first hole is smaller than a maximum outer diameter of the cooling pipe; a first burring portion extending from an inner edge of the first hole in an extending direction of the cooling pipe; The inner periphery of the first burring portion is in close contact with the outer periphery of the cooling pipe over the entire circumference. A unit cooler characterized by:

[0060] (Third aspect) The defrost pipe is a defrosting pipe through which warm brine or hot gas passes, a second burring portion extending from an inner edge of the second hole in an extending direction of the defrosting pipe; The inner periphery of the second burring portion is in close contact with the outer periphery of the defrosting pipe over the entire periphery. A unit cooler according to a second aspect, characterized in that:

[0061] (Fourth aspect) The fins have spacers that abut adjacent fins. The unit cooler according to the second or third aspect, characterized in that:

[0062] (Fifth aspect) The first holes are arranged in rows parallel to each other along the flow direction of air passing through the fin. A unit cooler according to a second aspect, characterized in that:

[0063] (Sixth aspect) In the method for manufacturing a unit cooler according to any one of the second to fifth aspects, forming the first burring portion around the first hole of the fin by punching a metal plate material using a die; After inserting the cooling pipe into the first hole, the cooling pipe is expanded by sending a pressurized fluid into the cooling pipe. A method for manufacturing a unit cooler. [Explanation of symbols]

[0064] 10 Unit Cooler 12. Case 14 Intake hood 20 Heat exchanger 21 Finn 21a 1st hole 21d First Barring Section 21c spacer 21b 2nd hole 21e Second Burring Section 22 Cooling piping 23 Defrost piping 30 Fan unit 32 Exhaust duct 34 Blower motor 34a Fan 36 Stay

Claims

1. a housing through which air passes; a fan device including a fan that introduces air into the housing; a heat exchanger disposed within the housing; the heat exchanger includes a plurality of fins each having a plurality of insertion holes, and a plurality of pipes passing through the insertion holes of the fins; The inner periphery of the insertion hole is in close contact with the outer periphery of the pipe over the entire circumference. A unit cooler characterized by:

2. a housing through which air passes; a fan device including a fan that introduces air into the housing; a heat exchanger disposed within the housing; the heat exchanger includes a plurality of fins each having a plurality of first holes and a plurality of second holes, a plurality of cooling pipes passing through the first holes of the fins, and a plurality of defrost pipes passing through the second holes of the fins; an inner diameter of the first hole is smaller than a maximum outer diameter of the cooling pipe; a first burring portion extending from an inner edge of the first hole in an extending direction of the cooling pipe; The inner periphery of the first burring portion is in close contact with the outer periphery of the cooling pipe over the entire periphery. A unit cooler characterized by:

3. The defrost pipe is a defrosting pipe through which warm brine or hot gas passes, a second burring portion extending from an inner edge of the second hole in an extending direction of the defrosting pipe; The inner periphery of the second burring portion is in close contact with the outer periphery of the defrosting pipe over the entire periphery.

3. The unit cooler according to claim 2.

4. The fins have spacers that abut adjacent fins.

3. The unit cooler according to claim 2.

5. The first holes are arranged in rows parallel to each other along the flow direction of air passing through the fins.

3. The unit cooler according to claim 2.

6. In the method for manufacturing a unit cooler according to any one of claims 2 to 5, forming the first burring portion around the first hole of the fin by punching a metal plate material using a die; After inserting the cooling pipe into the first hole, a pressurized fluid is sent into the cooling pipe to expand the cooling pipe. A method for manufacturing a unit cooler.

Images