JP2837831B2 - Finned tube manufacturing method and finned tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a finned tube and a method for manufacturing the same. The finned tube is used, for example, as a heat exchange means of a Joule-Thomson type cooling device.

[0002]

2. Description of the Related Art A finned tube of a Joule-Thomson type cooling device has, for example, a band-shaped fin member having a rectangular cross section at a pitch of about 0.25 mm on the outer periphery of a refrigerant gas introduction pipe having an outer diameter of 0.5 mm. It is configured to be wound and fixed in a coil shape. In order to increase the heat exchange efficiency, the fin member is wound so that the side surface corresponding to the short side of the rectangular cross section faces the outer peripheral surface of the refrigerant gas introduction pipe. Hereinafter, a conventional method of manufacturing a finned tube will be described using a finned tube used in a Joule-Thomson type cooling device as an example.

[0003] First, solder plating is applied to the outer peripheral surface of the refrigerant gas introduction pipe. A band-shaped fin member is wound in a coil at a desired pitch on the outer peripheral surface of the solder gas-introduced refrigerant gas inlet tube. The fin member is fixed to the refrigerant gas introduction pipe by heating the refrigerant gas introduction pipe to melt the solder, and then lowering the temperature to solidify the solder.

[0004]

The step of winding the fin members in a coil at a desired pitch requires a high level of skill and requires a long time.

An object of the present invention is to provide a technique for manufacturing a finned tube that can be manufactured in a simple manner and can reduce the manufacturing time.

[0006]

According to one aspect of the present invention, there is provided a step of preparing a fin member having a coil shape, and forming the fin member into a cylindrical tube having an outer diameter equal to or smaller than the inner diameter of the coil of the fin member. There is provided a method for manufacturing a finned tube, comprising the steps of: inserting a fin member into a hollow space inside a coil of a member; and fixing the fin member to the cylindrical tube.

Since there is no step of directly winding the fin member around the cylindrical tube, a finned tube can be simply and stably manufactured. According to another aspect of the present invention, the step of preparing the fin member is such that one adjacent portion of the coil is closely attached to the outer peripheral surface of the member having a cylindrical outer peripheral surface in the axial direction of the outer peripheral surface. Thus, there is provided a method for manufacturing a finned tube including a step of forming a fin member by winding a rod-shaped member into a coil shape.

[0008] By winding the fin members in close contact with each other in the pitch direction, the yield at the time of winding can be improved. According to another aspect of the present invention, the step of adhering to the cylindrical tube includes a step of extending the fin member, in which the cylindrical tube is inserted into the cavity inside the coil, in the longitudinal direction of the coil to increase the coil pitch. A method for manufacturing a finned tube is provided.

After the fin member that has been tightly wound is stretched to have a desired coil pitch, a cylindrical tube is inserted into the cavity inside the coil. According to another aspect of the present invention, the step of preparing the fin member includes the step of winding a rod-shaped member into a coil at a certain pitch on a member having an outer peripheral surface having a diameter smaller than the outer diameter of the cylindrical tube. A method for manufacturing a tube is provided.

[0010] After the rod-shaped member is wound on the cylindrical outer peripheral surface, when the restriction at the time of winding is released, the coil inner diameter of the coil-shaped rod-shaped member becomes slightly larger than the diameter of the wound outer peripheral surface. By anticipating this increase in diameter, a fin member having a desired coil inner diameter can be formed by previously winding the rod-shaped member on the outer peripheral surface having a diameter slightly smaller than the outer diameter of the cylindrical tube.

According to another aspect of the present invention, the step of fixing to the cylindrical tube includes immersing the fin member and the cylindrical tube inserted into the coil inner cavity of the fin member in a solder plating solution, and performing plating. By doing so, there is provided a method for manufacturing a finned tube including a step of fixing the fin member to the cylindrical tube.

After inserting a cylindrical tube into the coil cavity of the fin member, plating is performed in a solder plating solution,
A solder layer having a substantially uniform thickness can be formed on the surfaces of the fin member and the cylindrical tube. Since solder clogging between the fins is less likely to occur, a decrease in heat exchange efficiency due to a decrease in surface area can be prevented.

According to another aspect of the present invention, a cylindrical tube having a cylindrical outer peripheral surface, a fin wound in a coil shape on the outer peripheral surface of the cylindrical tube, an outer peripheral surface of the cylindrical tube and the fin And a solder layer for covering the entire surface of the cylindrical surface and fixing the fin to the cylindrical tube.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for manufacturing a finned tube according to a first embodiment of the present invention will be described with reference to FIG.

As shown in FIG. 1A, a coil-shaped fin member 1 made of, for example, phosphor bronze or stainless steel and having a pitch p ₀ is prepared. Coiled fin member 1
Is manufactured, for example, by winding a band-shaped member on the outer peripheral surface of a columnar member.

FIG. 1B is a perspective view of a half portion obtained by bisecting the fin member 1 on a plane including the center axis of the coil. The cross section of the belt-shaped member has a rectangular shape, and is configured such that the radial width w of the coil is larger than the axial thickness t of the coil.

FIG. 1A and FIG. 1B show a case where one circumferential portion of the coil is formed at a fixed interval from one circumferential portion adjacent thereto, but are adjacent to each other. One round portion may be adhered. That is, the coil pitch p ₀ may be equal to the thickness t of the belt-shaped member. By winding the band-shaped member in close contact, it is possible to prevent the band-shaped member from falling down and the wide side surface of the band-shaped member from adhering to the outer peripheral surface of the cylindrical member, and to stably produce the coil-shaped fin member 1. it can.

A cylindrical tube 2 shown in FIG. 1 (C) is prepared. The outer diameter of the cylindrical tube 2 is equal to or slightly smaller than the inner diameter of the coil of the coiled fin member 1 shown in FIGS. 1 (A) and 1 (B). As shown in FIG. 1 (D), by expanding or compressing the fin member 1 in the axial direction of the coil as desired coil pitch p _1, inserting the cylindrical tube 2 to the coil within the cavity of the coil fin member 1. With the coil pitch maintained, the fin member 1 and the cylindrical tube 2 are immersed in a solder plating solution and electroplated. Solder enters the gap between the fin member 1 and the cylindrical tube 2, and the fin member 1 is fixed on the outer peripheral surface of the cylindrical tube 2.

FIG. 1E is a partial cross-sectional view of the cylindrical tube 2 and the fin member 1 fixed thereto. A solder layer 3 covering the entire surface of the fin member 1 and the outer peripheral surface of the cylindrical tube 2 is formed. The fin member 1 is fixed to the cylindrical tube 2 by the solder layer 3.

When the fin member is fixed to the cylindrical tube by the method according to the conventional example, when the solder layer previously formed on the outer peripheral surface of the cylindrical tube is melted, the solder is formed between the fins by capillary action. May be buried. When the space between the fins is filled, the effective surface area for performing heat exchange is reduced, so that the heat exchange efficiency is reduced. In contrast, according to the present embodiment, a solder layer having a substantially uniform thickness covering the exposed surfaces of the fin member and the cylindrical tube can be formed, so that a decrease in heat exchange efficiency can be prevented.

FIG. 1 illustrates the case where the fin member is formed of phosphor bronze or stainless steel, but may be formed of another material. For example, when formed of copper, the heat exchange efficiency can be further improved.

Referring to FIG. 2, a method for manufacturing a finned tube according to a second embodiment of the present invention will be described. The left end of the ribbon-shaped member 10 in the figure is fixed to the mandrel 11 with the fastening metal 13. The mandrel 11 is rotated, and the ribbon-shaped member 10 is wound around the outer peripheral surface of the mandrel 11. The position of the winding portion of the ribbon-shaped member 10 in the axial direction is restricted by the side guide mechanism 12. When the mandrel 11 rotates, the side guide mechanism 12
Is moved to the right in the figure, so that the ribbon-shaped member 10
Can be wound at a desired pitch.

When the ribbon-shaped member 10 wound in a coil shape is removed from the mandrel 11, the inner diameter of the coil becomes slightly larger due to the restoring force of the ribbon-shaped member 10. The outer diameter of the mandrel 11 is previously made slightly smaller than the desired inner diameter of the coil so that the inner diameter of the coil after the restoration of the ribbon-shaped member 10 becomes the desired size. Thus, FIG. 1A of the first embodiment is shown.
The fin 1 shown in FIG.

The fin 1 is fixed to the cylindrical tube 2 by a method similar to the method described in FIG. 1D of the first embodiment. When fins are directly wound around a cylindrical tube, it is necessary to perform a winding step for each cylindrical tube. The above first and second
According to the embodiment, by using a mandrel longer than the cylindrical tube, fins of a plurality of cylindrical tubes can be manufactured in a single winding step.

FIG. 3 is a sectional view of a Joule-Thomson type cooling apparatus using a finned tube manufactured by the method according to the first or second embodiment. The Joule-Thomson type cooling device is configured to include a refrigerant gas introduction pipe 10, a fine hole 11, a needle 12, a needle drive mechanism 20, and a Dewar bottle 30.

A fin 14 for efficiently exchanging heat inside and outside the refrigerant gas introduction pipe is attached to the outer peripheral surface of the refrigerant gas introduction pipe 10 by the method described with reference to FIG. The refrigerant gas introduction pipe 10 is spirally wound around the outer peripheral surface of the cylindrical member 13 at such a pitch that the fins 14 are almost in contact with each other. The refrigerant gas introduction pipe 10 is formed of, for example, a copper-nickel alloy, and the fins 14 are formed of, for example, copper. A string 15 is wound so as to fill the gap between the fins 14 adjacent in the spiral axis direction. The string 15 can stably fix the refrigerant gas introduction pipe 10. One end of the cylindrical member 13 has a lid member 16 made of stainless steel or the like.
, And the other end is, for example, an open end (not shown).

A cavity 18 is formed inside the cover member 16, and the cavity 18 is connected to the refrigerant gas introduction pipe 10 via a gas pipe 17. In addition, the cavity 18 has the fine hole 11
Communicates with the outside. The refrigerant gas is supplied from the refrigerant gas introduction pipe 10 into the cavity 18, and the refrigerant gas in the cavity 18 is ejected to the outside through the fine holes 11.

The needle 12 has a tapered tip,
It is arranged so that a part of the tip is inserted into the fine hole 11. The central portion of the needle 12 is curved in a U-shape, and is attached to a needle holding member 27 described later. The needle 12 is formed of, for example, stainless steel.

The needle driving mechanism 20 includes a holding container 21,
Movable lid 22, fixed lid 23, bellows 24, coil spring 2
5 and a needle holding member 27. The holding container 21 is a cylindrical container, and is fixed to the cylindrical member 13 so that its outer peripheral surface is in close contact with the inner peripheral surface of the cylindrical member 13.

The movable lid 22 is inserted into the holding container 21,
A fixed lid 23 is attached to the opening of the holding container 21. The movable lid 22 is attached to the fixed lid 23 by a coil spring 25 and is elastically supported. The edge of the movable lid 22 and the bottom surface of the holding container 21 are connected by a bellows 24, and the movable lid 22, the bellows 24, and the holding container 21
An airtight cavity 26 is defined by the bottom surface of.

One end of the needle holding member 27 is attached to the movable lid 22, and extends through the fixed lid 23 and the lid member 16 to the outside of the cylindrical member 13. The needle 12 is attached to an end of the needle holding member 27 that is led out of the cylindrical member 13. Note that the needle 12 may be formed integrally with the needle holding member 27.

The needle holding member 27 is hollow from the end on the movable lid 22 side to the portion extending outside the cylindrical member 13. This hollow portion communicates with the cavity 26 and the cavity 2
Airtightness is maintained with 6. A gas having a pressure higher than the atmospheric pressure is sealed in the cavity 26. The sealing gas is, for example, nitrogen, argon, or air. Movable lid 2
Reference numeral 2 stands still at a position where the pressure of the sealed gas and the elastic force of the coil spring 25 are balanced. When the temperature of the sealed gas changes and the pressure in the cavity 26 changes, the rest position of the movable lid 22 changes.

[0033] The refrigerant gas introduction pipe 1 constructed as described above.
The part including the microhole 11, the needle 12, and the needle driving mechanism 20 is inserted into the Dewar 30 having a double wall structure, and an expansion space 31 is defined between the lid member 16 and the inner wall of the Dewar 30. ing. The Dewar bottle 30 is formed of, for example, glass. The inner diameter of the inner wall of the Dewar bottle 30 is set to a size such that its inner peripheral surface substantially contacts the fin 14.

A part of the outer wall of the Dewar bottle 30 at the upper end is constituted by an infrared transmitting member 33. The infrared transmitting member 33 is formed of, for example, germanium, sapphire, or the like.

An object 40 to be cooled is attached to the inner wall of the Dewar 30 at a position facing the infrared transmitting member 33. The interior cavity 32 of the double wall of the Dewar bottle 30 is vacuum-sealed after the object to be cooled 40 is attached. Cooled object 4
Reference numeral 0 denotes an infrared detecting element using, for example, a Schottky junction between silicon and platinum cobalt.

Next, the operation of the Joule-Thomson type cooling apparatus shown in FIG. 3 will be described. A high-pressure refrigerant gas is supplied from the lower end of the refrigerant gas introduction pipe 10 in the drawing. The refrigerant gas is, for example, nitrogen, argon, air, or the like. The refrigerant gas is introduced into the cavity 18 through the refrigerant gas introduction pipe 10,
The gas is ejected from the fine holes 11 into the expansion space 31. At this time,
Cold occurs due to the Joule Thomson effect, and the object to be cooled 4
Cool 0.

The low-temperature refrigerant gas in the expansion space 31 is discharged to the outside through the space between the cylindrical member 13 and the inner wall of the Dewar bottle 30. At this time, the low-temperature refrigerant gas cools the refrigerant gas introduction pipe 10. Since the fins 14 are provided in the refrigerant gas introduction pipe 10, heat can be efficiently exchanged between the gas flowing inside the refrigerant gas introduction pipe 10 and the gas flowing outside. In addition, since the string 15 obstructs the flow of the refrigerant gas to generate turbulence, the heat exchange efficiency is improved. Since the refrigerant gas flowing through the refrigerant gas introduction pipe 10 exchanges heat with the discharged refrigerant gas and is cooled, the cooling efficiency can be improved.

When the temperature in the expansion space 31 decreases, the temperature of the hollow space of the needle holding member 27 on the expansion space 31 side also decreases. When the temperature falls below the liquefaction point of the filling gas, the filling gas in the hollow cavity of the needle holding member 27 liquefies, and the pressure in the cavity 26 decreases. When the internal pressure decreases, the movable lid 22 is pushed down by the coil spring 25, and the needle 12 is inserted deeper into the minute hole 11. For this reason, the amount of refrigerant gas jetted decreases.

When the amount of refrigerant gas ejected decreases, the expansion space 3
Since the temperature inside 1 rises, the pressure inside cavity 26 rises, and the insertion amount of needle 12 into fine hole 11 becomes shallow. The ejection amount of the refrigerant gas increases, and the temperature in the expansion space 31 decreases. In this way, the temperature in the expansion space 31 can be adjusted, and the refrigerant gas can be saved.

It is preferable that a part of the filling gas in the cavity 26 is liquefied at the operating temperature. If a part is liquefied, the amount of liquefaction increases and decreases due to a slight change in temperature, and the pressure in the cavity 26 fluctuates greatly, so that a temperature change can be detected sensitively.

The Joule refrigerant gas inlet pipe 10 and the fins 14 for use in Thomson type cooling device is a very compact parts, coil pitch p ₁ of about 0.25mm shown in FIG. 1 (D) as an example, Figure 1 The thickness t of the fin member shown in FIG.
Is about 0.064 mm and the width w is about 0.025 mm. The outer diameter of the refrigerant gas introduction pipe 10 is about 0.5 mm. According to the method of manufacturing a finned tube according to the first or second embodiment, the yield in the process of manufacturing such a fine finned tube can be improved.

The present invention has been described in connection with the preferred embodiments.
The present invention is not limited to these. For example, it will be apparent to those skilled in the art that various modifications, improvements, combinations, and the like can be made.

[0043]

As described above, according to the present invention,
The coiled fin can be easily and stably fixed on the outer peripheral surface of the cylindrical tube. Further, since clogging of the solder between the fins does not easily occur, it is possible to prevent a decrease in heat exchange efficiency due to a decrease in the surface area.

[Brief description of the drawings]

FIG. 1 is a front view of a fin member for explaining a method of manufacturing a finned tube according to a first embodiment of the present invention, a perspective view of a half portion cut along a plane passing through a central axis, and a front view of a cylindrical tube. FIG. 3 is a front view and a partial cross-sectional view of a tube with fins.

FIG. 2 is a front view schematically showing a manufacturing apparatus for explaining a method for manufacturing a finned tube according to a second embodiment of the present invention.

FIG. 3 is a cross-sectional view of a Joule-Thomson cooling device using a finned tube.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fin member 2 Cylindrical tube 3 Solder layer 5 Ribbon member 6 Mandrel 7 Side guide mechanism 8 Clamping fitting 10 Refrigerant gas introduction pipe 11 Micro hole 12 Needle 13 Cylindrical member 14 Fin 15 String 16 Cover member 17 Tube 18 Cavity 19 Groove 20 Needle Driving mechanism 21 Holding container 22 Movable lid 23 Fixed lid 24 Bellows 25 Coil spring 26 Cavity 27 Needle holding member 28 Gap 30 Dewar bottle 40 Cooled object

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F25B 9/02 B21D 53/06 F25B 9/00 F28F 1/36

Claims (6)

(57) [Claims] A step of preparing a coil-shaped fin member; a step of inserting a cylindrical tube having an outer diameter equal to or smaller than an inner diameter of the coil of the fin member into a coil inner cavity of the fin member; Fixing a fin member to the cylindrical tube. 2. The step of preparing the fin member includes a step of forming a rod-shaped member such that one adjacent portion of a coil is closely attached to the outer peripheral surface of a member having a cylindrical outer peripheral surface in the axial direction of the outer peripheral surface. The method for manufacturing a finned tube according to claim 1, comprising a step of forming the fin member by winding the member into a coil shape. 3. The method according to claim 2, wherein the step of fixing to the cylindrical tube includes a step of extending the fin member in which the cylindrical tube is inserted into a coil inner cavity in a coil length direction to increase a coil pitch. A method for producing the finned tube according to the above. 4. The method according to claim 1, wherein the step of preparing the fin member includes a step of coiling a rod-shaped member at a certain pitch around a member having an outer peripheral surface having a diameter smaller than the outer diameter of the cylindrical tube. Manufacturing method of finned tube. 5. The step of fixing the fin member to the cylindrical tube by immersing the fin member and the cylindrical tube inserted into the coil inner cavity of the fin member in a solder plating solution and plating the fin member. The method for producing a finned tube according to any one of claims 1 to 4, comprising a step of fixing the fin to the cylindrical tube. 6. A cylindrical tube having a cylindrical outer peripheral surface, a fin wound in a coil shape on the outer peripheral surface of the cylindrical tube, and covering the entire outer peripheral surface of the cylindrical tube and the entire surface of the fin. And a solder layer for fixing the fin to the cylindrical tube.