JP5700831B2 - Manufacturing method of sintered heat pipe - Google Patents

Description

  The present invention relates to a method for manufacturing a heat pipe that transports heat by the flow of a working fluid enclosed in a container. In particular, the present invention relates to a method for manufacturing a sintered heat pipe formed by sintering metal powder as a wick for returning a working fluid to an evaporation section.

  The heat pipe is used for cooling a device such as a CPU of a personal computer. The heat pipe is a sealed metal body in which a non-condensable fluid is degassed and an appropriate amount of hydraulic fluid is enclosed. The working fluid sealed inside evaporates by being heated from the outside of the container (evaporating part), and when cooled, the vapor is condensed and returned to the working liquid (condensing part), and transports heat as latent heat. Since heat is transported as latent heat, heat transport can be performed even with a small temperature difference between the evaporation section and the condensation section.

  A hollow tube is used for a general heat pipe container. Since this container needs to conduct heat inside and outside, it is made of a material with high thermal conductivity. For example, metals such as copper and aluminum are used. Moreover, water, alcohol, methanol, alternative chlorofluorocarbon, ammonia, etc. are used for the hydraulic fluid.

  In the container, the working fluid condensed in the condensing part is returned to the evaporation part. When the evaporating unit is located below the condensing unit, a thermosiphon heat pipe that drops and returns the working fluid by gravity can be used.

  However, when the evaporation unit is positioned above the condensation unit or both are positioned horizontally due to the positional relationship between the evaporation unit and the condensation unit, the surface tension of the hydraulic fluid is used for the reflux of the hydraulic fluid. Therefore, a wick structure is required inside the container.

  As the wick structure, a linear body obtained by bundling a plurality of fine wires, a mesh body such as a mesh, or a sintered body obtained by sintering powder such as copper powder is used. It is known that a powder using powder can obtain a high surface tension.

  In order to fix the powder in the container, as shown in Patent Document 1, a core rod having a notch is inserted into the container, and a metal is formed in the space formed by the container and the core rod. Fill with powder. It is known to fix the container by sintering by heating the container with the metal powder and the core rod inserted.

JP 2009-68787 A

  At the time of manufacture, in Patent Document 1, a metal powder is filled into a space formed by a core bar having a notch and a container. When the sintered metal is fixed by heating, the core rod and the sintered metal are fixed, and the core rod may not be easily pulled out.

  If the core rod cannot be easily pulled out after fixing the sintered metal, it takes time to move to the next step during manufacturing. Therefore, the problem which reduces the productivity of a heat pipe arises.

  The present invention provides a sintered heat pipe capable of facilitating drawing of a used wick-forming plate after the metal powder is fixed by sintering at the time of manufacturing a sintered heat pipe wick structure. Is the method.

  The present inventor has intensively studied to solve the conventional problems described above. As a result, one aspect of the present invention provides a tube-shaped container, a step of inserting a molding plate so that both ends are in contact with the inner wall of the container along the major axis direction of the container, and one surface of the molding plate, Filling the space between the inner wall of the container facing one surface of the molded plate with metal powder, the other surface of the molded plate, and the other inner wall of the container facing the other surface of the molded plate The process of inserting the presser bar into the space between and the container is heated while pressing the metal powder against the inner wall of the container with the presser bar and the molding plate, and the metal powder is sintered to form the wick structure. A method for manufacturing a sintered heat pipe, comprising: a step of pulling a presser bar and a molded plate from a container; a step of flattening the container; and a step of enclosing a working fluid in the container.

The molded plate may be a flat plate or another shape. Further, the metal powder is filled in contact with a flat surface or a curved surface formed on one surface of the molded plate according to a desired shape of the wick structure. The presser bar may be a cylinder or a polygonal column.

  According to this invention, because the metal powder is fixed by the molded plate and the presser bar, the molded plate and the presser bar can be pulled out separately after sintering. Since the presser bar is not in contact with the metal powder, it does not adhere to the metal powder by sintering. Therefore, it can be easily pulled out. Further, a force can be applied to the molded plate in the direction of the space generated by pulling out the presser bar. As a result, even when the molded plate and the metal powder are fixed, the peeling can be easily performed.

  Since it is composed of a molded plate and a presser bar, the shape of the molded plate can be made in consideration of the shape of the wick structure when the container is flattened. Depending on the shape of the wick structure, a simple flat plate can be used as the molded plate. Further, even when the wick structure has a complicated shape, since it can be configured by a combination of a molded plate and a presser bar, each of the molded plate and the presser bar can be configured by a simple shape. As a result, the processing cost of the forming plate and the presser bar can be reduced.

It is sectional drawing which shows an example of the sintering heat pipe which concerns on embodiment of this invention. It is a schematic diagram explaining an example of the manufacturing method of the sintered heat pipe which concerns on embodiment of this invention. It is the schematic which shows the AA cross section of the tube-shaped container shown in FIG.2 (b). It is sectional drawing which shows the other example of the filling process of the metal powder in the manufacturing method of the sintered heat pipe concerning embodiment of this invention. It is sectional drawing which shows the other example of the filling process of the metal powder in the manufacturing method of the sintered heat pipe concerning embodiment of this invention. It is sectional drawing which shows the other example of the filling process of the metal powder in the manufacturing method of the sintered heat pipe concerning embodiment of this invention. It is sectional drawing which shows the other example of the filling process of the metal powder in the manufacturing method of the sintered heat pipe concerning embodiment of this invention.

 Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between the thickness and the planar dimensions, the ratio of the thickness of each layer, and the like are different from the actual ones. Therefore, specific thicknesses and dimensions should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

 The following embodiments of the present invention exemplify apparatuses and methods for embodying the technical idea of the present invention. The technical idea of the present invention is based on the material and shape of component parts. The structure, arrangement, etc. are not specified below. The technical idea of the present invention can be variously modified within the technical scope described in the claims.

  The sintered heat pipe according to the embodiment of the present invention includes a container 1 and a wick structure 8 as shown in FIG. The container 1 has a flat tube shape. The wick structure 8 is provided so as to be thin at the center of the container 1 and thick at both ends. The cavity 9 is formed between the inner wall of the container 1 and the wick structure 8 so as to be thicker at the center than at both ends.

  The container 1 is a tubular pipe made of metal such as copper having high thermal conductivity. The wick structure 8 is made of a porous sintered metal such as copper, bronze or stainless steel. The sintered metal is formed by sintering metal powder. A sintered metal is a metal powder joined by sintering. The pores of the sintered metal can be adjusted by adjusting the size of the metal powder such as spherical powder or irregular powder.

  Next, a method for manufacturing a sintered heat pipe according to an embodiment of the present invention will be described with reference to FIGS.

  As shown to Fig.2 (a), the container 1, the shaping | molding board 3, and the presser bar 5 are prepared. For example, as the container 1, a copper pipe having a thickness of 0.3 mm and an outer diameter of 3.0 to 6.0 mm that has been cleaned such as degreasing is cut into a predetermined length and used. The molded plate 3 is a plate having a V-shaped cross section perpendicular to the extending direction. The presser bar 5 is a columnar bar. In addition, although the cross-sectional shape of the presser bar 5 may be circular, it may be a complicated shape such as a polygon.

  The forming plate 3 and the presser bar 5 are made of carbon, ceramic, stainless steel or the like. In particular, the molded plate 3 is preferably stainless steel that can be easily molded. The sizes of the forming plate 3 and the presser bar 5 are appropriately adjusted according to the size of the container 1. The length of the forming plate 3 and the presser bar 5 is longer than the length of the container 1 so that it can be easily inserted and removed.

  As shown in FIGS. 2B and 3, the molding plate 3 is inserted along the long axis direction of the tubular container 1 so that both ends of the molding plate 3 are in contact with the inner wall of the container 1. A metal powder 7 is filled in a space between the outward surface of the V-shaped molded plate 3 and the inner wall of the container 1 facing the outward surface. After the metal powder 7 is filled, the presser bar 5 is inserted into the space between the inward surface of the molded plate 3 and the inner wall of the container 1 facing the inward surface. The amount of the metal powder 7 enclosed can be adjusted by the size of the molded plate 3 and the presser bar 5. The metal powder 7 is pressed to the container 1 side by the presser bar 5 and the molded plate 3.

  The filled metal powder 7 is heated at a predetermined temperature, for example, a temperature around the melting point of the metal powder 7 with the molding plate 3 and the presser bar 5 fixed, and is in contact with the inner wall of the container 1 to be porous. A wick structure 8 made of sintered metal is formed. The wick structure 8 refers to a sintered metal in which the metal powder 7 is joined by sintering. When the container 1 and the wick structure 8 are made of copper, they are heated to about 800 to 1000 ° C. Thereby, the wick structure 8 is sintered and fixed to the inner wall surface of the container 1 over the entire length. On the other hand, the molded plate 3 and the wick structure 8 are hardly fixed.

  The forming plate 3 and the presser bar 5 are composed of separate members. After forming, the presser bar 5 is pulled out first. At that time, since the presser bar 5 is not in contact with the wick structure 8, there is no fixation due to sintering, and it can be pulled out easily.

  The remaining molding plate 3 can apply a force in the direction of the space where the presser bar 5 is located, that is, in a direction other than the major axis direction, by removing the presser bar 5. As a result, as shown in FIG. 2 (c), even if the wick structure 8 and the molded plate 3 are partially fixed, the fixed portion can be peeled off and the molded plate 3 can be pulled out. In addition, depending on the molding plate 3, by applying a force, a slight but temporary deformation or deformation such as distortion occurs, and the fixing portion is more easily peeled off.

  After the molded plate 3 is pulled out, a swaging process is performed on one end of the container 1, and bottom welding is performed to weld and seal the end. Further, the other end portion of the container 1 is also subjected to a swaging process to provide a nozzle-like liquid injection port.

  Using the injection port, non-condensable gas such as air contained in the container is degassed, and water, methanol, ethanol, alternative chlorofluorocarbon, or ammonia or other hydraulic fluid is injected. As a liquid injection method, vacuum deaeration is performed using a liquid injection port, and then a working liquid is injected, or an excessive amount of a working liquid is injected in advance, and the container is heated to discharge the working liquid. There are methods such as heating to drive out non-condensable gas by boiling.

  After the injection, the nozzle-like injection port that has been opened is closed and sealed by welding. The round pipe type heat pipe thus manufactured is crushed in the radial direction to obtain a flat type heat pipe. At this time, when it is necessary to bend or bend the major axis direction of the heat pipe, the round pipe type heat pipe is bent or bent into a predetermined shape and then flattened by being crushed in the radial direction. Also in these processes, since the wick structure 8 is fixed by sintering in the container 1, the positional relationship between the working fluid flow path and the steam flow path is ensured in the major axis direction.

  In the embodiment, when the wick structure 8 is formed, the metal powder 7 is sintered against the inner wall of the container 1 by the forming plate 3 and the presser bar 5. Since the presser bar 5 is not in contact with the metal powder 7, it can be easily pulled out from the container 1 after sintering. Further, the molding plate 3 is made of a material that is not easily fixed to the wick structure 8. Furthermore, since a space is formed at the position where the presser bar 5 previously pulled out, a force can be applied in the direction of the space when the molded plate 3 is pulled out. As a result, the molded plate 3 can also be easily pulled out.

  Since the molded plate 3 and the presser bar 5 are used in sintering the metal powder 7, the shape of the molded plate 3 can be formed in consideration of the shape of the wick structure 8 when the container 1 is flattened. Depending on the shape of the wick structure 8, a simple flat plate can be used as the molded plate 3. Further, even when the wick structure 8 has a complicated shape, since it can be configured by a combination of the forming plate 3 and the presser bar 5, each of the forming plate 3 and the presser bar 5 can be configured in a simple shape. . As a result, the processing cost of the forming plate 3 and the presser bar 5 can be reduced.

  In the above description, the V-shaped molded plate 3 is used, but the shape of the molded plate 3 is not limited. For example, as shown in FIG. 4, by enlarging the V-shaped angle to increase the size of the presser bar 5, the amount of metal powder 7 enclosed can be reduced compared to the configuration shown in FIG. Can do.

  Moreover, as shown in FIG.5 and FIG.6, you may use a flat plate shape as the shaping | molding board 3a. This is used when the wick structure 8 is formed in the center of the container 1. The filling amount of the metal powder 7 is determined according to the size of the wick structure 8 to be formed. What is necessary is just to adjust the length of the shaping | molding board 3a with respect to the filling amount of the metal powder 7. FIG.

  Moreover, you may use a deformed board as the shaping | molding board 3b. The molded plate 3b is formed in advance in consideration of the shape of the finished wick structure. The shape of the presser bar 5a is appropriately determined according to the shape of the molding plate 3b. For example, as shown in FIG. 7, a convex curved surface is provided toward the inner wall of the container 1 in the central portion of the molding plate 3 b. The metal powder 7 is filled in contact with the curved surface. When the container 1 is flattened, the wick structure 8 is formed in a trapezoidal shape. The presser bar 5a has a shape in which the end part is in contact with both ends of the molding plate 3b and is fitted into a concave curved surface in the center part. The shape of the presser bar 5a is appropriately determined according to the shape of the molding plate 3b. The cross-sectional shape of the presser bar 5a may be a circle, an ellipse, a polygon, or the like as long as the molded plate 3b can be pressed in addition to the complicated shape described above. In short, it is only necessary that the metal powder 7 can be pressed to the container 1 side by the molded plate 3b.

(Other embodiments)
Although the embodiments of the present invention have been described as described above, it should not be understood that the descriptions and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art. Accordingly, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

  DESCRIPTION OF SYMBOLS 1 ... Container, 3 ... Molded board, 5 ... Presser bar, 7 ... Metal powder, 8 ... Wick structure.

Claims (5)

Preparing a tube-shaped container, and inserting a molding plate so that both ends thereof are in contact with the inner wall of the container along the major axis direction of the container;
Filling a metal powder in a space between one surface of the molded plate and one inner wall of the container facing the one surface;
Inserting a presser bar into the space between the other surface of the molded plate and the other inner wall of the container facing the other surface;
Heating the container while pressing the metal powder against one inner wall of the container with the presser bar and the forming plate, and sintering the metal powder to form a wick structure;
Extracting the presser bar and the molded plate from the container;
A step of flattening the container;
And a step of enclosing a working fluid in the container.   The method for manufacturing a sintered heat pipe according to claim 1, wherein the molded plate is a flat plate.   The method for manufacturing a sintered heat pipe according to claim 1, wherein the metal powder is filled in contact with a plane formed on the one surface.   The method for manufacturing a sintered heat pipe according to claim 1, wherein the metal powder is filled in contact with a curved surface formed on the one surface.   The method for manufacturing a sintered heat pipe according to any one of claims 1 to 4, wherein the presser bar is a cylinder or a polygonal column.

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