JP2014025610A - Wick manufacturing method and wick structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wick manufacturing method and a wick structure capable of easily removing a core from a sintered wick, or suppressing or preventing breakage of a wick when removing the core.SOLUTION: In a wick manufacturing method for manufacturing a wick by disposing a core 16 inside a type member 14, placing a first powder 12a between the type member 14 and the core 16, and sintering it, after covering the external surface of the core 16 with a member 13 with a cross sectional area of a gap larger than a cross sectional area of a gap formed by sintering the first powder 12a, the first powder 12a is put between the member 13 with a large cross sectional area of the gap and the type member 14, and sintered. Then, by removing the core 16, the wick is manufactured, which has an outer layer formed by the first powder 12a being sintered, and an inner layer formed inside thereof by the member 13 with a large cross sectional area of the gap.

Description

  TECHNICAL FIELD The present invention relates to a manufacturing method and a wick structure of a wick provided in a heat pipe that cools a portion to be cooled by transporting heat as latent heat, and in particular, manufacturing a wick formed by sintering powder. It relates to a method and a wick structure.

  The wick used for the heat pipe is configured to absorb and flow the liquid-phase working fluid by capillary pressure. Since the capillary pressure increases as the cross-sectional area of the gap decreases, a sintered wick formed by sintering metal powder is used, particularly in the loop heat pipe used in the top heat mode. . On the other hand, when the gap of the wick is formed small, the cross-sectional area of the flow path through which the liquid-phase working fluid flows becomes small, and in the case of a sintered wick, the gap becomes a labyrinth. Becomes larger. As a result, there is a possibility that the carbonization characteristics in the heat pipe may be deteriorated.

  The wicks described in Patent Documents 1 to 3 combine a cylindrical wick with a large air gap and a wick with a small air gap surrounding the outer peripheral side to infiltrate the liquid-phase working fluid with the inner peripheral wick. At the same time, the working fluid is sucked by the capillary pressure generated in the outer wick. In particular, the wick described in Patent Document 1 is formed by forming a wick on the inner peripheral side with a resin material in order to suppress or prevent evaporation of the liquid-phase working fluid that has permeated the wick on the inner peripheral side. The heat conductivity of the inner wick is lower than that of the outer wick.

JP 2012-37097 A Japanese Patent Laid-Open No. 10-246583 JP 2006-125783 A

  The outer wicks described in Patent Documents 1, 2, and 3 are configured by sintering powder to generate a high capillary pressure. Moreover, the wick described in Patent Document 1 is formed by inserting an inner wick into the hollow portion of the outer wick. That is, after the outer wick and the inner wick are formed in different steps, each wick is assembled. On the other hand, when forming a cylindrical sintered wick, the core forming the hollow portion is inserted into the mold member forming the outer peripheral surface, and the powder is placed between the core and the mold member. Since it is put and sintered, the core expands due to the heat accompanying the sintering and the powder can be compressed and formed. On the other hand, since the powder is bonded by sintering, The inner diameter of the wick becomes smaller and the frictional force with the core increases. Further, the core and the wick after sintering are partially sintered. Therefore, there is a possibility that the force when removing the core from the inside of the wick increases, or the wick is damaged when removing the core. Furthermore, since the inner peripheral surface of the outer wick is compressed by the core during sintering, the cross-sectional area of the void opened on the inner peripheral surface of the outer wick is reduced, but the gap opening is closed. There is a possibility that. If the opening of the gap is closed in such a manner, the working fluid penetrates from the inner wick to the outer wick even if the inner wick has good permeability. As a result, there is a possibility that the capillary pressure for circulating the working fluid may decrease, or that dryout may occur in the outer wick.

  The present invention has been made by paying attention to the above technical problem, and can easily remove the core from the sintered wick, or can prevent the wick from being damaged when the core is removed. Or it aims at providing the manufacturing method and wick structure of a wick which can be prevented.

  In order to achieve the above object, according to the first aspect of the present invention, a core is disposed inside a mold member, and the first powder is placed between the mold member and the core and sintered. In the wick manufacturing method of manufacturing a wick, the outer surface of the core is covered with a member having a gap cross-sectional area larger than the gap cross-sectional area formed by sintering the first powder. The first powder is sintered by putting the first powder between a member having a large cross-sectional area of the gap and the mold member, and then removing the core to sinter the first powder. A wick having an outer layer formed in this manner and an inner layer formed by a member having a large cross-sectional area of the gap inside is manufactured.

  The invention according to claim 2 is the method of manufacturing a wick according to claim 1, wherein the member having a large cross-sectional area of the void includes a bundle or mesh of fine wires of metal material or heat-resistant inorganic fiber. .

  A third aspect of the present invention is the manufacturing of the wick according to the first aspect, wherein the member having a large cross-sectional area of the void includes a second powder having an outer diameter larger than the outer diameter of the powder. Is the method.

  According to a fourth aspect of the present invention, in the third aspect of the invention, a wall member that partitions a space between the core and the mold member is inserted, and the second member is interposed between the wall member and the core. After the first powder is put between the wall member and the mold member, the wall member is removed, and then the first powder and the second powder are added. It is a manufacturing method of a wick characterized by sintering.

  The invention of claim 5 is the invention according to any one of claims 1 to 3, wherein the core is covered with a porous member, and then the core covered with the porous member is disposed inside the mold member. This is a method for manufacturing a wick.

  According to a sixth aspect of the present invention, there is provided a wick structure formed by putting powder in a mold member and sintering the outer layer formed by sintering the powder, and a metal material or an inner side of the outer layer. And an inner layer formed by a bundle of fine wires or a mesh of heat-resistant inorganic fibers.

  The invention of claim 7 is the invention of claim 1, wherein a bundle or mesh of fine wires of the metal material or heat resistant inorganic fiber is arranged inside the mold member, and the fine wire of the metal material or heat resistant inorganic fiber is arranged. The wick structure is characterized in that each of the outer layer and the inner layer is formed by putting a powder between a bundle or mesh and the mold member and sintering the powder.

  The invention of claim 8 is characterized in that, in the invention of claim 6 or claim 7, the powder and the bundle of fine wires or mesh of the metal material or heat-resistant inorganic fiber are formed of the same material. It is a wick structure.

  According to the present invention, a wick formed by being sintered by placing a core inside the mold member, putting the first powder between the mold member and the core, and sintering the powder. Can be formed. Further, after the outer surface of the core is covered with a member having a void whose sectional area is larger than the sectional area of the void formed by sintering the first powder, a member and a mold having a large sectional area of the void It sinters after putting a 1st powder between members. Therefore, the member having a large cross-sectional area of the gap and the core are difficult to sinter, and as a result, the force required for removing the core can be reduced, or the wick is broken when removing the core. Can be suppressed or prevented.

  Further, by covering the core with a bundle or mesh of fine wires of metal material or heat-resistant inorganic fiber, the inner layer formed by the fine wires can function as a reinforcing member. Therefore, it is not necessary to increase the temperature at the time of sintering excessively, and as a result, the cost associated with the manufacture of the wick can be reduced. Moreover, it can suppress or prevent that the member which covers a core at the time of sintering volatilizes or melts. Furthermore, even if the powder is connected by sintering and the inner diameter of the outer layer is reduced, the inner layer is interposed between the core and the outer layer, so that the core is excessively compressed. It can be suppressed or prevented. Therefore, it is possible to further reduce the force required when removing the core, or to suppress or prevent the wick from being damaged when removing the core.

  Furthermore, the inner layer and the outer layer can be integrally formed by sintering the inner layer and the outer layer at the same time.

It is sectional drawing for demonstrating the manufacturing method of the wick which concerns on this invention. It is a perspective view which shows a loop type heat pipe. It is sectional drawing for demonstrating the structure of an evaporator. It is the figure which showed the cross section which follows the IV-IV line | wire in FIG. It is sectional drawing for demonstrating the manufacturing method of the wick of another shape.

  Next, an example of a loop heat pipe that can use the wick according to the present invention will be described. The loop type heat pipe shown in FIG. 2 absorbs heat from a heat generating unit (not shown) and changes the phase of a liquid-phase working fluid into a gas-phase working fluid, and the gas phase flowing from the evaporator 2 The condenser 3 that radiates the heat of the working fluid and changes the phase to the liquid working fluid, the vapor pipe 4 through which the gaseous working fluid discharged from the evaporator 2 flows toward the condenser 3, and the condensation The liquid phase working fluid flows from the container 3 toward the evaporator 2. Each of these members 2, 3, 4, and 5 is connected in an airtight manner, and is configured so that the working fluid supplied in advance circulates while changing phase. Specifically, the heat absorbed by the evaporator 2 from the heat generating portion changes into a gaseous working fluid and flows to the condenser 3 and is transported to the working fluid as latent heat. The heat generating part can be cooled by radiating heat from 3. The working fluid is condensed with the evaporator 2 by capillary pressure generated in a wick (described later) provided in the evaporator 2 or energy of a gas-phase working fluid that flows by absorbing thermal energy. It is comprised so that it may circulate through the vessel 3.

  Here, the configuration of the evaporator 2 will be described. The evaporator 2 shown in FIG. 2 includes a container 6 that forms the appearance of the evaporator 2 as shown in FIG. 3, a wick 7 provided inside the container 6, and a bayonet tube 8 connected to the liquid tube 5. And. A container 6 shown in FIG. 3 is formed in a cylindrical shape from a metal material having good thermal conductivity such as copper, and caps 9a and 9b each having a through hole at the center at both ends of the container 6. Are connected. A plurality of slits 10 and 10 are formed on the inner peripheral surface of the container 6 on the steam pipe 4 side in the circumferential direction at predetermined intervals along the axial direction. FIG. 4 shows a cross-sectional view of the container 6 along the line IV-IV in FIG. Furthermore, the inside of the container 6 on the liquid tube 5 side is configured to function as a liquid reservoir 11 that temporarily stores a liquid-phase working fluid, and the inner diameter thereof is almost the same as the recess 10 a in the slit 10. The diameter is formed.

  Then, the opening end on one side of the steam pipe 4 is connected to the through hole in the cap 9a on the steam pipe 4 side in an airtight manner by welding or the like, and one end in the liquid pipe 5 is connected to the through hole in the cap 9b on the liquid pipe 5 side. The open ends on the side are connected in an airtight manner by welding or the like. In addition, a cylindrical bayonet tube 8 having a diameter smaller than the inner diameter of the liquid tube 5 is provided inside the liquid tube 5, and the bayonet tube 8 passes through the through hole and enters the container 6. It is arranged to extend. More specifically, one end of the bayonet tube 8 is provided so as to be positioned in a hollow portion of the wick 7 described later.

  Next, the configuration of the wick shown in FIG. 3 will be described. The wick 7 shown in FIG. 3 is a bottomed cylindrical member with the steam pipe 4 side closed, and the bayonet tube 8 is spaced from the inner surface of the wick 7 by a predetermined distance to the central portion of the hollow portion in the axial direction. Has been placed. The wick 7 is formed such that the outer diameter on the liquid pipe 5 side is larger than the outer diameter on the steam pipe 4 side, and the portion 7 a on the liquid pipe 5 side is in close contact with the inner surface of the container 6 in the liquid reservoir 11. It is formed to do. Further, the outer diameter on the steam pipe 4 side is formed so as to come into contact with the inner surface of the convex portion 10 b in the slit 10 formed on the inner surface of the container 6. That is, the wick 7 is inserted into the container 6 from the liquid pipe 5 side and is positioned by the end of the slit 10 on the liquid pipe 5 side. As described above, the wick 7 is in contact with the inner surface of the container 6 or the inner surface of the convex portion 10 b in the slit 10, and heat is transmitted from the container 6 through the contact surface. Hereinafter, the portion on the steam pipe 4 side in the wick 7 is referred to as an evaporation portion 7b. Further, as described above, since the outer peripheral surface of the wick 7 on the side of the liquid tube 5 is in close contact with the inner peripheral surface of the container 6, the liquid-phase working fluid stored in the liquid reservoir 11 evaporates. It is comprised so that it may function as a seal | sticker which prevents flowing to the outer peripheral surface of the part 7b, or the steam pipe 4. FIG. Furthermore, since the outer peripheral surface of the wick 7 and the inner peripheral surface of the convex portion 10 b in the slit 10 are configured to contact each other, heat is transmitted to the wick 7 and the liquid-phase working fluid that has permeated into the wick 7. Is changed to a gas-phase working fluid, and the gas-phase working fluid flows in the recess 10a in the slit 10 and flows to the vapor pipe 4 side. That is, the recess 10a in the slit 10 is configured to function as a flow path through which the gas phase working fluid flows.

  The wick 7 shown in FIG. 3 is formed by an outer peripheral wick 12 forming an outer shape and an inner peripheral wick 13 integrally connected to the inner peripheral side of the outer peripheral wick 12. First, the configuration of the outer wick 12 will be described. The outer wick 12 has a bottomed cylindrical shape formed in the same shape as the outer shape of the wick 7, and the inner diameter thereof is slightly larger than the inner diameter of the wick 7. The outer wick 12 is a porous sintered wick formed by sintering a powder of a metal material such as copper, nickel, or titanium, and the powders are partially sintered. As a result, a plurality of minute voids are formed. Therefore, the wick 12 on the outer peripheral side can generate a capillary pressure that sucks the working fluid through a gap having a small cross-sectional area. In other words, the particle diameter of the powder and the cross-sectional area of the void by sintering are determined to such an extent that a sufficient capillary pressure is generated.

  Further, the inner wick 13 integrally formed on the inner peripheral surface of the outer wick 12 is a porous thin wick formed by bundling fine wires or knitting fine wires, It is formed in a bottom cylindrical shape. And the outer peripheral surface and front-end | tip part in the inner peripheral wick 13 are formed in close contact with the inner surface of the outer peripheral wick 12. The inner wick 13 may be made of the same material as the outer wick 12 or may be a heat resistant inorganic fiber such as carbon fiber. The inner peripheral wick 13 has a larger gap cross-sectional area than the outer peripheral wick 12. The inner wick 13 preferably has good liquid-phase working fluid wettability.

  By configuring the evaporator 2 as described above, the liquid phase working fluid is supplied from the bayonet tube 8 to the hollow portion of the wick 7 via the liquid tube 5. A part of the liquid-phase working fluid penetrates into the wick 7, and surplus working fluid that cannot penetrate the wick 7 flows on the inner peripheral surface of the wick 7 and is supplied to the liquid reservoir 11. And temporarily stored. Further, the working fluid that has permeated the wick 7 is sucked to the outer peripheral side of the wick 7 by capillary pressure. This is because the outer peripheral surface of the wick 7 is in contact with the inner surface of the container 6 or the inner surface of the convex portion 10b in the slit 10, so that the liquid-phase working fluid changes into a gas-phase working fluid at that portion. This is because the gas-phase working fluid flows into the steam pipe 4. Then, the working fluid sucked to the outer peripheral side of the wick 7 changes into a gaseous working fluid, and heat transferred from the container 6 to the condenser 3 through the steam pipe 4 as latent heat.

  Here, the manufacturing method of the wick 7 mentioned above is demonstrated. FIG. 1 is a view for explaining a manufacturing method of the wick 7, and a mold member 14 for forming the outer shape of the outer wick 12 is used. Specifically, the outer wick 12 has a portion having the same inner diameter as the outer diameter of the portion formed with a relatively large outer diameter and the same inner diameter as the outer diameter of the portion formed with a smaller outer diameter. A mold member 14 having a portion having the same is used. In addition, the mold member 14 is formed in a hollow shape, and one end side, more specifically, an end on the side formed with a large inner diameter is opened, and the other end is It is closed by a disk portion 15 having a through hole for putting powder.

  A core 16 formed in a cylindrical shape is inserted into the mold member 14. In addition, the material of the core 16 should just be a material which is not fuse | melted with the temperature at the time of sintering, As an example, stainless steel etc. can be used. Further, one end of the core 16 is formed so as to close and close the one end of the mold member 14. That is, the opening of the mold member 14 is closed by assembling the core 16 having a portion formed larger than the inner diameter of one end of the mold member 14 to the mold member 14.

  And the core 16 is assembled | attached to the type | mold member 14 in the state covered with the material for forming the wick 13 of the inner peripheral side. Specifically, the core 16 is covered with a bundle of metal wires such as copper, nickel or titanium or heat-resistant inorganic fibers such as carbon that are bundled or knitted. The child 16 is inserted and assembled. After the core 16 is assembled to the mold member 14, powders 12 a and 12 a for forming the outer wick 12 are inserted from the through hole in the disk portion 15, and the through hole is closed by a pin 17 or the like. .

  As described above, the material for forming the inner wick 13 and the outer wick 12 was inserted into the mold member 14 and sealed, and heated and sintered from the outside of the mold member 14. Thereafter, when the temperature is lowered to a predetermined temperature, the core 16 is removed from the mold member 14, and the wick 7 is extracted from the mold member 14.

  As described above, when the core 16 is sintered with the inner wick 13 covered, the core 16 and the inner wick 13 are not easily sintered, and the powders 12a and 12a are sintered together. Since a part of the compressive force of the outer wick 12 having the smaller inner diameter can be received by the inner wick 13, the compressive force acting on the core 16 can be reduced. As a result, it becomes easy to remove the core 16 after sintering, and the wick 7 is damaged when the core 16 is removed because the inner wick 13 and the core 16 are not sintered. The situation can be suppressed or prevented. The reason why the core 16 and the inner wick 13 are difficult to sinter is that the gap formed by the contact between the core 16 and the fine wire during sintering is large, This is because the surface tension is small. Further, as described above, the inner peripheral wick 13 is formed by a continuous member such as a thin wire, whereby the inner peripheral wick 13 can function as a reinforcing member for the wick 7 as a whole. In other words, even when sintered at a relatively low temperature, since the inner wick 13 is formed by a continuous member, the powders 12a and 12a are sufficiently welded to each other during sintering. There is no need to increase the temperature, and as a result, the manufacturing cost for the sintering temperature can be reduced. Further, by using a fine wire of metal material or heat-resistant inorganic fiber, the fine wire or fiber does not volatilize or melt during sintering.

  In addition, although the example which forms the inner periphery side wick 13 with a thin wire | line was given and demonstrated, in short, the inner periphery side wick 13 should just be formed with the core 16 and the member which is hard to be sintered. . That is, it is only necessary that the cross-sectional area of the gap formed by the core 16 and the member for forming the inner wick 13 is increased. Accordingly, the inner wick 13 may be a sintered wick formed of powder having a relatively large outer diameter. When the inner wick 13 is formed by sintering wicks, a cylindrical separator is inserted between the mold member 14 and the core 16, and a small diameter powder is formed on the outer periphery of the separator. 12a, 12a is put, a large diameter powder is put on the inner peripheral side, and then the separator is removed and then sintered. By sintering in this way, the cross-sectional area of the gap between the powder placed on the inner peripheral side of the separator and the core 16 is increased. As a result, the powder forming the wick 13 on the inner peripheral side and the middle The child 16 is hardly sintered. Therefore, it is possible to reduce the load when the core 16 is removed after sintering, and it is possible to suppress or prevent the wick 7 from being damaged when the core 16 is removed.

  In addition, as described above, since the inner wick 13 is interposed between the core 16 and the outer wick 12, sintering is performed, the gap opened on the inner surface of the outer wick 12 is closed. This can be suppressed or prevented. As a result, the liquid-phase working fluid that has permeated the inner peripheral wick 13 is likely to permeate the outer wick 12.

  In the above-described example, the manufacturing method in which the outer wick 12 and the inner wick 13 are simultaneously sintered has been described as an example, but the inner wick 13 is formed in advance by sintering. May be. Further, as described above, not only a wick having a relatively large diameter portion and a small diameter portion, but also a cylindrical wick can be formed as shown in FIG. Furthermore, in the example mentioned above, although the example comprised by the wick 13 of the inner peripheral side and the wick 12 of the outer peripheral side was given, between the inner peripheral wick 13 and the outer peripheral wick 12 was given. It may be composed of three layers of wicks with other wicks interposed therebetween, or may be composed of wicks of more layers. That is, the manufacturing method or structure of the wick according to the present invention may be any wick formed of a plurality of layers. In the above-described example, the slit 10 is formed on the inner surface of the container 6 to form a flow path through which the gas-phase working fluid flows, but the slit is formed on the outer peripheral surface of the outer wick 12. You may form the flow path through which a gaseous-phase working fluid flows. In that case, the outer surface of the outer wick 12 is formed by forming irregularities for forming the slit 10 on the inner surface of the mold member 14 and sintering the powder 12a, 12a inside. A slit 10 can be formed in the substrate.

  7 ... Wick, 12 ... Outer wick, 12a ... Powder, 13 ... Inner wick, 14 ... Mold member, 15 ... Disc part, 16 ... Core, 17 ... Pin.

Claims (8)

In the manufacturing method of the wick, the core is disposed inside the mold member, and the first powder is placed between the mold member and the core to sinter the wick, thereby manufacturing the wick.
After covering the outer surface of the core with a member having a cross-sectional area of the void larger than the cross-sectional area of the void formed by sintering the first powder, the member having a large cross-sectional area of the void and the member The first powder is put between the mold member and sintered, and then the core is removed, whereby the outer layer formed by sintering the first powder, and the inside of the outer layer are formed. A wick manufacturing method comprising manufacturing an wick having an inner layer formed by a member having a large cross-sectional area of a void.   The wick manufacturing method according to claim 1, wherein the member having a large cross-sectional area of the void includes a bundle of fine wires or a mesh of a metal material or a heat-resistant inorganic fiber.   The wick manufacturing method according to claim 1, wherein the member having a large cross-sectional area of the void includes a second powder having an outer diameter larger than the outer diameter of the powder.   A wall member that divides a space between the core and the mold member is inserted, and the second powder is placed between the wall member and the core, and the wall member and the mold member The first powder is put between the first powder, the wall member is removed, and then the first powder and the second powder are sintered. Wick manufacturing method.   4. The method of manufacturing a wick according to claim 1, wherein the core is covered with a porous member, and then the core covered with the porous member is disposed inside the mold member. . In the wick structure formed by putting the powder in the mold member and sintering it,
An outer layer formed by sintering the powder;
A wick structure comprising an inner layer formed of a bundle or mesh of fine wires of metal material or heat-resistant inorganic fiber inside the outer layer.   A bundle or mesh of fine wires of the metal material or heat-resistant inorganic fiber is disposed inside the mold member, and a powder is placed between the bundle or mesh of fine wires of the metal material or heat-resistant inorganic fiber and the mold member. The wick structure according to claim 1, wherein each of the outer layer and the inner layer is formed by putting and sintering.   The wick structure according to claim 6 or 7, wherein the powder and the bundle or mesh of fine wires of the metal material or heat resistant inorganic fiber are formed of the same material.

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