JP2014185801A - Self-excited oscillation heat pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a self-excited oscillation heat pipe having improved starting characteristics at low temperature.SOLUTION: A self-excited oscillation heat pipe disclosed in the present specification comprises pressure transmission means provided at the middle of a sealed pipe for transferring pressure fluctuation in one side space to the other side space. The pressure transmission means is allowed to have heat transport characteristics different between on one side and on the other side. The heat pipe on one side (first heat pipe) is allowed to have the heat transport amount less than that of the heat pipe on the other side (second heat pipe) and to have the responsiveness at low temperature superior to that of the second heat pipe. The first heat pipe starts up more quickly than the second heat pipe in a low temperature environment, and the oscillation of the first heat pipe is transmitted to the second heat pipe by the pressure transmission means. The transmitted pressure oscillation induces self-excited oscillation of the second heat pipe, and the self-excited oscillation is started more quickly than in the case of the single element second heat pipe. The pressure transmission means is provided in the folding part of the pipe, and the assemblability is excellent.

Description

  The present invention relates to a self-excited vibration heat pipe.

  A self-excited vibration heat pipe is a device in which a closed thin tube is folded back multiple times (reciprocated multiple times) and a highly volatile liquid (working fluid) is enclosed inside. Install a heat source near one end of the narrow tubes arranged in parallel (near the folded portion). The side to which the heat source is attached is referred to as a heat receiving part (or evaporation part), and the other end of the narrow tubes arranged in parallel is referred to as a heat dissipation part (condensing part). The hydraulic fluid is evaporated by the heat of the heat source at the heat receiving portion. Since evaporation occurs at a plurality of locations (near a plurality of folded portions) of the thin tube, the entire thin tube is in a state where a gas phase and a liquid phase exist alternately. Due to the evaporation of the hydraulic fluid, the pressure of the heat receiving part increases. As the pressure in the heat receiving part increases, the liquid phase and the gas phase hydraulic fluid move to the heat radiating part. The gas phase hydraulic fluid is condensed in the heat radiating portion and returned to the liquid. Thus, the hydraulic fluid moves between the heat receiving portion and the heat radiating portion due to a pressure change caused by the phase change of the hydraulic fluid. That is, the hydraulic fluid vibrates self-excited. The self-excited vibration type heat pipe has high heat transport efficiency because heat is transferred by both latent heat accompanying evaporation and condensation and sensible heat of the working fluid. In addition, since the self-excited vibration heat pipe has a simple structure and can be easily reduced in size, it is often used as a cooling device for semiconductor devices such as power devices and CPUs.

  The characteristics of self-excited vibration heat pipes depend on the cross-sectional area of the tube, the amount of hydraulic fluid per unit volume of the tube, or the type of hydraulic fluid. And the response at low temperatures (startability at low temperatures) are in a trade-off relationship. The reason is that, in a very simplified manner, a large heat transport amount means a large heat capacity, and a large amount of energy is required to evaporate the working fluid (move the working fluid). .

  Thus, various proposals have been made in order to improve the characteristics at low temperatures. In Patent Document 1, a pump is connected to a pipe of a heat pipe, and when the temperature is low, the pump actively vibrates the hydraulic fluid to induce self-excited vibration.

  In Patent Document 2, two heat pipes having different heat transport characteristics are housed in one housing. The two heat pipes are sealed with hydraulic fluids having different melting points. A heat pipe sealed with a working fluid having a low melting point operates even when the outside air temperature is low. When the outside air temperature rises or the temperature of the heat source rises, the heat pipe sealed with the high melting point working fluid starts to operate, and the heat transport amount increases.

JP 2006-319046 A JP 2009-260058 A

  The heat pipe of Patent Document 1 includes an actuator, and actively induces self-excited vibration at low temperatures. The heat pipe of Patent Document 5 corresponds to providing two heat pipes having substantially different characteristics.

  Some of the inventors of the present application have devised a heat pipe with improved characteristics at low temperatures without requiring an active driving force such as a power source (Japanese Patent Application No. 2013-004397, filed on January 15, 2013). And unpublished at the time of filing this application). This specification provides a technology for realizing a novel heat pipe disclosed in Japanese Patent Application No. 2013-004397 at a low cost.

  The self-excited vibration heat pipe disclosed in Japanese Patent Application No. 2013-004397 is as follows. The heat pipe is provided with a pressure transmission means for transmitting pressure fluctuations while gas and liquid do not pass through the sealed pipe. That is, the internal space of the sealed tube is partitioned into a space on one side and a space on the other side across the pressure transmission means. And the heat transport characteristic which is different in the space of the one side and the space of the other side is given. In other words, such a self-excited vibration heat pipe is formed by connecting a first heat pipe and a second heat pipe having different heat transport characteristics by pressure transmission means that transmits gas and liquid but transmits pressure fluctuations. It is a device. The heat transport property includes good startability at low temperatures. In other words, in the above self-excited vibration heat pipe, the space in the heat pipe pipe is divided into two in the length direction, and the pressure fluctuation generated in one of the divided spaces is divided into the other space. Pressure transmitting means for transmitting is provided. As described above, the amount of heat transport (cooling capacity) and the response at low temperatures (startability at low temperatures) are in a trade-off relationship, and the first heat pipe has a smaller heat transport amount than the second heat pipe. The responsiveness at low temperature is configured to be excellent (the characteristics of the first heat pipe and the characteristics of the second heat pipe may be reversed). The first heat pipe starts faster than the second heat pipe in a low temperature environment. Then, the vibration of the first heat pipe is transmitted to the second heat pipe by the pressure transmission means. The transmitted pressure fluctuation induces self-excited vibration of the second heat pipe, and the second heat pipe starts self-excited vibration earlier than an equivalent single heat pipe. In this self-excited vibration heat pipe, the second heat pipe having a large heat capacity is started earlier than the conventional heat pipe without including an active actuator.

  The pressure transmission means may typically be a piston or a diaphragm (diaphragm). Also, the heat transport characteristics of the first heat pipe and the second heat pipe (that is, one side and the other side of the pressure transmission means) are different from each other in that the pipe cross-sectional area, the amount of hydraulic fluid per unit volume of the pipe, the action This can be achieved by differentiating at least one of the type of liquid and the heat flux. The pressure transmission means may be an elastic body.

  The self-excited vibration heat pipe has a plurality of sealed tubes folded back. In the technology disclosed in this specification, in the above-described novel self-excited vibration heat pipe, the pressure transmission means is provided in any folded portion. By providing the pressure transmission means at the folded portion, the assembly of the heat pipe is improved.

  In many cases, a plurality of bent-back pipes are composed of the following three types of parts. One is a body in which a plurality of parallel flow paths having both ends open are formed. The body may be a perforated pipe formed by extrusion molding (in which case, each hole corresponds to a flow path), or may be a bundle of a plurality of pipes. The remaining two are first and second closing members that respectively cover one end side and the other end side of the plurality of flow paths (that is, cover one end side and the other end side of the body). The first closing member that covers one end side of the plurality of flow paths allows the ends of the two flow paths to communicate with each other in the set of two adjacent flow paths. The second closing member that covers the other end of the plurality of flow paths is different for each of a pair of two adjacent flow paths adjacent to the two flow paths that communicate with the first closing member. The ends of the two flow paths are communicated. A structure in which a plurality of flow paths in the body are connected to one of the first and second closing members corresponds to the above-described plurality of folded pipes.

  Therefore, in one embodiment of the self-excited vibration heat pipe disclosed in the present specification, the pressure transmission means is provided inside any one of the flow paths, and on the inner surface of the first or second closing member. Facing. Alternatively, in another embodiment, the pressure transmission means is provided on the first or second closing member. In the former embodiment, the first or second closing member may be attached after the pressure transmission means is incorporated from the end of the flow path. In the latter embodiment, the assembly of the pressure transmission means is completed when the first or second closing member is assembled to the plurality of flow paths. In any of the embodiments, it is not necessary to insert the pressure transmission means to the vicinity of the center of the flow path, and the manufacturing is easy. Moreover, once the flow path is produced, additional processing for assembling the pressure transmission means is unnecessary. In the following, for the sake of simplicity, the “self-excited vibration heat pipe” may be simply referred to as “heat pipe” for convenience.

  The heat pipe has folded portions at both ends of the parallel flow paths. A heat source is attached to one folded portion, and heat from the heat source is released at the other folded portion. The folded part to which the heat source is attached is called a heat receiving part (or evaporation part), and the other folded part is called a heat radiating part (or condensing part). The pressure transmission means may be provided in the folded portion on the heat radiating portion side. The hydraulic fluid becomes a liquid phase at the heat radiating portion, and the pressure transmission means vibrates in the liquid phase. Since the liquid phase has a higher density than the gas phase, the energy transmitted by the vibration of the pressure transmission means is larger than that of the gas phase. That is, by providing the heat transmission part with the pressure transmission means, the efficiency of pressure transmission is high compared to the case where the heat transmission part is disposed.

  Details and further improvements of the technology disclosed in this specification will be described in the following “DETAILED DESCRIPTION”.

It is sectional drawing which shows the structure of the heat pipe of 1st Example. It is a graph explaining the relationship between the thermal resistance of a heat pipe, and a heat flow rate. It is sectional drawing which shows the structure of the heat pipe of 2nd Example. It is a partial expanded sectional view which shows the structure of the heat pipe of 3rd Example. It is a partial expanded sectional view which shows the structure of the heat pipe of 4th Example. It is a partial expanded sectional view which shows the structure of the heat pipe of 5th Example. It is a partial expanded sectional view which shows the structure of the heat pipe of 6th Example. It is a partial expanded sectional view which shows the structure of the heat pipe of 7th Example. It is a partial expanded sectional view which shows the structure of the heat pipe of 8th Example. It is a partial expanded sectional view which shows the structure of the heat pipe of 9th Example. It is a partial expanded sectional view which shows the structure of the heat pipe of 10th Example. It is a partial expanded sectional view which shows the structure of the heat pipe of 11th Example. It is a partial expanded sectional view which shows the structure of the heat pipe of 12th Example.

  (First Embodiment) FIG. 1 shows a sectional view of a heat pipe 2 of the first embodiment. Although the heat pipe 2 includes a single closed tube that is folded back multiple times, FIG. 1 shows a cross section that crosses all the folded portions. In other words, FIG. 1 corresponds to a cross section that traverses the entire flow path from one end to the other end of one closed tube that is folded back.

  The heat pipe 2 is a device having a tube 5 sealed inside a flat body 3. The pipe 5 is filled with a small amount of hydraulic fluid. The hydraulic fluid is a highly volatile liquid, for example, an alternative chlorofluorocarbon.

  The body 3 is made of a metal having high thermal conductivity such as aluminum or copper. The body 3 is formed with a plurality of parallel flow paths 4a to 4h that are open at both ends. Both ends of the plurality of flow paths 4 a to 4 h are closed by the first closing member 12 and the second closing member 13. Similarly to the body 3, the first closing member 12 and the second closing member 13 are also made of a metal having high thermal conductivity such as aluminum. The first closing member 12 and the second closing member 13 are fixed to the body 3 by brazing, press fitting, joining, or other methods.

  In FIG. 1, the first closing member 12 that covers the openings above the plurality of flow paths 4a to 4h is a set of two adjacent flow paths (flow paths 4a and 4b, 4c and 4d, 4e and 4f, 4g and 4h. ), The ends of the two flow paths are communicated. In the upper opening in FIG. 4, the portion where the flow paths 4a and 4b communicate corresponds to the folded portion 9a. Similarly, in the upper opening in FIG. 4, a portion where the flow paths 4c and 4d communicate, a portion where the flow paths 4e and 4f communicate, and a portion where the flow paths 4g and 4h communicate correspond to the folded portion 9a.

  In FIG. 1, the second closing member 13 that covers the lower openings of the plurality of flow paths 4 a to 4 h is different from the pair of two flow paths that communicate with the first closing member 12 in the lower part of FIG. 1. The ends of the two flow paths are communicated with each other in the pair of the two flow paths adjacent to each other in the opening (flow paths 4b and 4c, 4d and 4e, 4f and 4g). In the lower opening in FIG. 4, the part where the flow paths 4 b and 4 c communicate corresponds to the folded part 9 b. Similarly, in the lower opening in FIG. 4, the portion where the flow paths 4d and 4e communicate and the portion where the flow paths 4f and 4g communicate correspond to the folded portion 9b. The plurality of flow paths 4a to 4h arranged in parallel in this way communicate with the flow paths that are alternately adjacent at both ends, and as a result, one closed tube 5 is formed. Note that both ends of the tube are closed with caps 14 on the second closing member 13 side. The tube 5 is sealed with a cap 14 after the working fluid is put inside.

  In the heat pipe 2, a heat source is attached to the surface of the body 3 corresponding to a region where the lower folded portions 9 b in FIG. 1 are arranged. A region where the lower folded portions 9b in FIG. 1 are arranged corresponds to the heat receiving portion Hv (evaporating portion). A region where the folded portions 9a are arranged on the side opposite to the heat receiving portion corresponds to the heat radiating portion Hr (condensing portion).

  A heat generation source is attached to the heat receiving portion Hv. The hydraulic fluid evaporates at the heat receiving portion Hv due to the heat of the heat source. The heat receiving portion Hv includes a plurality of folded portions 9b of the pipe 5, and the working fluid evaporates in each of the plurality of folded portions. The working fluid in the heat radiating portion Hr remains liquid. If it does so, a hydraulic fluid will be in the state in which the liquid phase and the gaseous phase were mixed inside the pipe | tube 5. FIG. When the hydraulic fluid becomes a gas at the heat receiving portion Hv, the pressure of the heat receiving portion Hv increases, and the entire hydraulic fluid moves to the heat radiating portion Hr. The gas phase hydraulic fluid that has moved to the heat radiating portion Hr is condensed and returned to the liquid phase. At that time, heat of condensation is released. As the gas-phase working fluid moves, the liquid-phase working fluid in the vicinity of the heat receiving portion Hv also moves to the heat radiating portion Hr and releases heat there. Thus, heat is transported by both the latent heat of vaporization and condensation and the sensible heat of the liquid-phase hydraulic fluid. The hydraulic fluid that has released heat in the heat radiating portion Hr is pushed by the high-temperature hydraulic fluid that is newly sent from the heat receiving portion Hv, and moves to the heat receiving portion Hv. Thus, the hydraulic fluid vibrates self-excited inside the tube 5. The heat source is not limited, but is typically an electronic device such as a semiconductor chip.

  In the middle of the tube 5, the pressure transmission portion 8 is provided in one folded portion 9 a of the heat radiating portion Hr. The pressure transmission unit 8 includes a piston 7 that slides along a flow path by a predetermined stroke. The end of the channel 4c is expanded to a predetermined length, and the piston 7 is inserted into the expanded portion. The piston 7 can freely move between a step corresponding to the boundary between the enlarged diameter portion and the non-expanded diameter portion and the first closing member 12. However, sealing oil is filled between the piston 7 and the inner wall of the pipe 5, and liquid and gas cannot pass through the space on one side and the space on the other side of the piston 7. In FIG. 1, it should be noted that a gap is intentionally drawn between the piston 7 and the inner wall of the pipe 5 in order to help understanding. The same applies to FIGS. 3 to 5 later.

  When pressure fluctuation occurs on one side of the pipe 5 with the piston 7 as a boundary, the piston 7 reciprocates according to the pressure fluctuation. The reciprocating motion of the piston 7 causes a pressure fluctuation on the other side of the tube 5. That is, the pressure transmission unit 8 transmits pressure fluctuations while gas and liquid do not pass through the space on one side and the space on the other side of the piston 7. Hereinafter, the space on one side of the piston 7 in the pipe 5 is referred to as a first heat pipe 5a, and the space on the other side is referred to as a second heat pipe 5b. In other words, in the heat pipe 2, the internal space of the pipe 5 is divided into two in the length direction, and a piston 7 (pressure transmission unit 8) is provided at the divided position. The piston 7 transmits pressure fluctuation generated in one of the divided spaces to the other space. Note that hydraulic fluid is placed in both the first heat pipe 5a and the second heat pipe 5b.

  The first heat pipe 5a and the second heat pipe 5b have different heat transport characteristics. Specifically, the amount of hydraulic fluid is different. In the present embodiment, the amount of hydraulic fluid in the first heat pipe 5a is smaller than the amount of hydraulic fluid in the second heat pipe 5b. Therefore, the first heat pipe 5a starts to operate even with a small amount of heat compared to the second heat pipe 5b. In other words, the first heat pipe 5a starts more quickly at low temperatures than the second heat pipe 5b.

  The heat transport characteristics due to the difference in the amount of hydraulic fluid will be specifically described with reference to FIG. FIG. 2 is a graph schematically showing the characteristics of the heat pipe. In the graph of FIG. 2, the vertical axis represents the heat resistance of the heat pipe, and the horizontal axis represents the heat flow rate of the heat pipe. The thermal resistance is a unit representing the difficulty of transferring heat, and corresponds to the amount of temperature increase per unit calorific value per unit time. The heat flow rate corresponds to the amount of heat that passes through a unit area per unit time. The lower right region of the graph in FIG. 2 indicates that the performance of the heat pipe, that is, the cooling capacity is higher. The graph G1 shows the characteristics of the first heat pipe 5a, and the graph G2 shows the characteristics of the second heat pipe 5b. The second heat pipe 5b has a lower thermal resistance in a region where the heat flow rate is higher than that of the first heat pipe 5a. That is, the cooling capacity of the second heat pipe 5b is higher than that of the first heat pipe 5a. However, when the outside air temperature is low or when the heat generation amount of the heat source is small, the heat flow rate does not increase originally. That is, the case where the outside air temperature is low or the case where the heat generation amount of the heat source is small corresponds to the region on the left side of the graph. In the region on the left side of the graph, the first heat pipe 5a has a smaller thermal resistance than the second heat pipe 5b. This indicates that the first heat pipe 5a is easier to operate than the second heat pipe 5b when the outside air temperature is low or the heat generation amount of the heat source is small, that is, the startability is good. Yes. That is, the first heat pipe 5a is superior in startability at a low temperature than the second heat pipe 5b, but the heat transport amount when the heat generation amount of the heat source is larger is the second heat pipe 5a than the first heat pipe 5a. The heat pipe 5b is larger.

  The function of the pressure transmission part 8 is demonstrated. As described above, in the heat pipe 2, the first heat pipe 5a starts before the second heat pipe 5b. That is, vaporization of the hydraulic fluid starts first in the first heat pipe 5a, and self-excited vibration starts. The pressure change due to the self-excited vibration is transmitted to the inside of the second heat pipe 5b through the pressure transmission unit 8. In the second heat pipe 5b, the pressure fluctuation from the first heat pipe 5a stimulates the hydraulic fluid, and self-excited vibration is induced. Thus, even in a region where the self-excited vibration does not normally start with a single heat pipe equivalent to the second heat pipe 5b, the second heat pipe 5b starts to operate due to stimulation from the first heat pipe 5a. The heat pipe 2 has better startability at a low temperature than the two heat pipes equivalent to the first heat pipe 5a and the second heat pipe 5b.

  The pressure transmission unit 8 (piston 7) is disposed in one folded portion 9a of the pipe 5 (flow path) that is folded back a plurality of times. As well shown in FIG. 1, the piston 7 is inserted from one end of the flow path 4 c prior to the attachment of the first closing member 12. When the first closing member 12 is attached after the piston 7 is inserted, the pressure transmission unit 8 is completed. Thus, since the pressure transmission part 8 is provided in the folding | returning part 9a, it is excellent in assemblability. As well shown in FIG. 1, the piston 7 (pressure transmission portion 8) faces the inner surface of the first closing member 12.

  (Second Embodiment) A second embodiment will be described. FIG. 3 is a cross-sectional view of the heat pipe 102 of the second embodiment. In this heat pipe 102, folded portions 109a to 109c are formed in the first and second closing members 112 and 113, and the pressure transmitting portion 8 (piston 7) is incorporated in one of them 109c. This is a different point from the heat pipe 2 of one embodiment. More specifically, the heat pipe 102 has the following configuration. The body 103 of the heat pipe 102 is formed with a plurality of parallel flow paths 4a to 4h that are open at both ends. The opening groups on both sides of the body 103 are closed by a first closing member 112 and a second closing member 113, respectively. The first closing member 112 that covers one end side of the plurality of flow paths 4a to 4h is provided for each of a pair of adjacent two flow paths (flow paths 4a and 4b, 4c and 4d, 4e and 4f, 4g and 4h). The ends of the two flow paths are communicated. The second blocking member 113 that covers the other end side of the plurality of flow paths is a pair of adjacent two flow paths (4b) so as to alternate with the two flow paths that the first closing member 112 communicates with. 4c, 4d and 4e, 4f and 4g), the ends of the other two flow paths are connected. The first closing member 112 is formed with folded portions 109a and 109c communicating with adjacent flow paths. Similarly, the second closing member 113 is also formed with a folded portion 109b communicating with the adjacent flow path. One folded portion 109c of the first closing member 112 is formed deeper than the other folded portion 109a. And the pressure transmission part 8 (piston 7) is provided in the folding | turning part 109c deeper than the others. In this configuration, since the pressure transmission unit 8 is already incorporated in the first closing member 112, the assembly is further superior to the heat pipe 2 of the first embodiment.

  Hereinafter, another embodiment will be described with reference to FIGS. In any of the embodiments, the pressure transmission portion 8 that divides the single pipe 5 into two spaces is provided in the folded portion on the heat radiating portion side. 4 to 13 are partial enlarged cross-sectional views of the folded portion where the pressure transmission unit 8 is provided. The parts not drawn in FIGS. 4 to 13 have the same structure as the heat pipe of the first embodiment (FIG. 1) or the second embodiment (FIG. 3).

  (Third Embodiment) FIG. 4 shows a partially enlarged sectional view of a heat pipe 102a of a third embodiment. The pressure transmission part 8 of the heat pipe 102 a is composed of a piston 7 and a spring 31. The piston 7 faces the inner surface of the first closing member 112. The spring 31 urges the piston 7 toward one of the divided spaces (heat pipes 5a and 5b). The rigidity of the spring 31 is selected so that the natural frequency of the spring 31 and the piston 7 substantially matches the vibration frequency of the gas phase in the first heat pipe 5a. Then, the vibration of the piston 7 is easily induced by the vibration of the gas-phase hydraulic fluid in the first heat pipe 5a. That is, it becomes easy for the second heat pipe 5b to start operating.

  (Fourth Embodiment) FIG. 5 shows a partially enlarged sectional view of a heat pipe 102b of a fourth embodiment. Similarly to the heat pipe 102a of the third embodiment, the pressure transmission portion 8 of the heat pipe 102b is also composed of the piston 7 and the spring 31. The difference from the third embodiment is that a pressure transmitting portion 8 including a piston 7 and a spring 31 is provided in the first closing member 112.

  (Fifth Embodiment) FIG. 6 shows a partially enlarged sectional view of a heat pipe 102c of the fifth embodiment. The heat pipe 102 c includes a pressure transmission unit 8 configured by a diaphragm 47. The diaphragm 47 transmits pressure fluctuation between the first heat pipe 5a and the second heat pipe 5b, but neither gas nor liquid is allowed to pass through. The diaphragm 47 is formed of, for example, a silicon sheet. The diaphragm 47 is attached to the end portion of the body 103 and faces the inner surface of the first closing member 112. This heat pipe 102c also has the same advantages as other heat pipes.

  (Sixth Embodiment) FIG. 7 shows a partially enlarged sectional view of a heat pipe 102d of the sixth embodiment. The pressure transmission unit 8 of the heat pipe 102 d is configured by a diaphragm 47 and a frame 48 that supports the periphery of the diaphragm 47. The pressure transmission unit 8 is incorporated in the first closing member 112. Since the soft diaphragm 47 is supported by the hard frame 48, the pressure transmission unit 8 is easily assembled to the first closing member 112. Typically, the frame 48 is attached to the folded portion 109c of the first closing member 112 by press-fitting or joining. As described above, the heat pipe 102d having the pressure transmission portion 8 composed of the frame 48 and the diaphragm 47 is more easily assembled.

  (Seventh Embodiment) FIG. 8 shows a partially enlarged sectional view of a heat pipe 102e of the seventh embodiment. Similarly to the heat pipe 102d of the sixth embodiment, the pressure transmission portion 8 of the heat pipe 102e is also composed of a diaphragm 47 and a frame 48 that supports it. However, the direction of the diaphragm 47 is different from that of the heat pipe 102d of the sixth embodiment. In the heat pipe 102d of the sixth embodiment, the diaphragm 47 faces in the same direction as the extending direction of the plurality of flow paths formed in the body 103. In the heat pipe 102e of the seventh embodiment, the diaphragm 47 faces a direction perpendicular to the extending direction of the plurality of flow paths formed in the body 103. In other words, the diaphragm 47 is a folded portion that communicates adjacent channels, and is disposed at a curved portion (bent portion) of a channel that communicates parallel channels. The heat pipe 102e can employ a diaphragm having a larger area than the heat pipe 102d of the sixth embodiment.

  Further, the pressure transmission portion 8 of the heat pipe 102 e is attached to the end portion of the body 103. Therefore, the shape of the first closing member 112 is simple. The pressure transmission unit 8 is incorporated in the first closing member 112. Since the soft diaphragm 47 is supported by the hard frame 48, the pressure transmission unit 8 is easily assembled to the first closing member 112. Typically, the frame 48 is attached to the folded portion 109c of the first closing member 112 by press-fitting or joining. The heat pipe 102e is also easy to assemble the pressure transmission unit 8.

  (Eighth Embodiment) FIG. 9 shows a partially enlarged sectional view of a heat pipe 102f according to an eighth embodiment. Similarly to the heat pipe 102e of the seventh embodiment, the pressure transmission portion 8 of the heat pipe 102f is also configured by a diaphragm 47 and a frame 48 that supports it. The heat pipe 102f is different from the heat pipe 102e of the seventh embodiment in that the pressure transmission unit 8 is incorporated in the first closing member 112.

  In the heat pipes 102c to 102f of the fifth to eighth embodiments, the natural frequency of the diaphragm 47 may be substantially matched with the natural frequency of the gas phase hydraulic fluid of the first heat pipe 5a.

  (Ninth to Twelfth Embodiment) FIGS. 10 to 13 are partially enlarged sectional views of heat pipes 102g to 102k according to ninth to twelfth embodiments. These heat pipes are provided with the pressure transmission part 8 of the elastic body 57 (157). The elastic body is typically rubber or a thin film bag in which a liquid is sealed. The elastic body 57 (157) closes the flow path and does not allow gas and liquid to pass through. In FIG. 10, it should be noted that a gap is intentionally drawn between the elastic body 57 (157) and the inner wall of the tube 5 to help understanding. The same applies to FIGS. 11 to 13 later. However, when the part facing one heat pipe 5a is subjected to pressure fluctuation, the part vibrates and the part facing the other heat pipe 5b vibrates. Therefore, the elastic body 57 (157) can also transmit pressure fluctuation from one heat pipe 5a to the other heat pipe 5b.

  In the heat pipe 102g (FIG. 10) of the ninth embodiment, a spherical elastic body 57 is disposed at the end of the body 103, and the elastic body 57 faces the first closing member 112. The first closing member 112 is provided with a recess 112 a that receives the spherical elastic body 57.

  In the heat pipe 102h (FIG. 11) of the tenth embodiment, a flat elastic body 157 is disposed at the end of the body 103, and the elastic body 157 faces the first closing member 112. Since the elastic body 157 is flat, it is stably supported by the flow path. Therefore, the depression 112a of the ninth embodiment is not necessary. Further, the elastic body 157 is in surface contact with the inner wall of the flow path along the bent portion, and has a high sealing property between gas and liquid.

  The heat pipe 102j (FIG. 12) according to the eleventh embodiment includes a spherical elastic body 57, similar to the heat pipe 102g according to the ninth embodiment. The heat pipe 102j is different from the heat pipe 102g of the ninth embodiment in that the elastic body 57 (pressure transmission unit 8) is incorporated in the first closing member 112 instead of the body 103.

  The heat pipe 102k (FIG. 13) of the twelfth embodiment includes a flat elastic body 157, similar to the heat pipe 102h of the tenth embodiment. The heat pipe 102k is different from the heat pipe 102h of the tenth embodiment in that an elastic body 157 (pressure transmission unit 8) is incorporated in the first closing member 112 instead of the body 103.

  Points to be noted regarding the technology described in the embodiments will be described. The heat pipe disclosed in this specification is connected to a first heat pipe having a good startability in a low temperature environment and a second heat pipe having a large heat transport amount, although the startability is inferior to that of the first heat pipe, by pressure transmission means. Device. In this heat pipe, the self-excited vibration of the first heat pipe serves as a stimulus for starting the second heat pipe, and the second heat pipe is easily started. The technology disclosed in this specification actively utilizes the “self-excited vibration” that is a feature of self-excited heat pipes, and can improve starting characteristics at low temperatures compared to conventional heat pipes without requiring an actuator. it can.

  The pressure transmission part 8 is arrange | positioned in the folding | turning part by the side of the thermal radiation part of the pipe | tube 5 turned back by multiple times. Therefore, the assembling property of the pressure transmission part 8 is good.

  The body 3 (103) having the parallel flow paths 4a to 4h may use a porous tube made by extrusion molding, or may be a bundle of a plurality of pipes. The parallel flow paths 4a to 4h may be curved on the way. The heat pipe disclosed in this specification has an advantage that not only an actuator is unnecessary, but also its manufacture is easy.

  In the first embodiment, the amount of hydraulic fluid is different between the first heat pipe and the second heat pipe. The first heat pipe and the second heat pipe need only have different heat transport characteristics, and the characteristics are not limited to the amount of hydraulic fluid. For example, the first heat pipe and the second heat pipe may have different cross-sectional areas. In addition to the amount and cross-sectional area of the hydraulic fluid, the first heat pipe and the second heat pipe may have different heat transport characteristics by changing the type of hydraulic fluid, the heat flow rate, and the like. Further, the body 3 of the heat pipe of the example was a flat plate type. The shape of the entire heat pipe is not limited to a flat plate, and may be a cylinder or a prism. Alternatively, an L-shaped plate may be used.

  In the heat pipe of the embodiment, the cooling capacity of the first heat pipe is higher than the cooling capacity of the second heat pipe. It is desirable that the space (typically length) occupied by the first heat pipe having a high cooling capacity is larger than the space occupied by the second heat pipe.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

2, 102, 102a-102k: heat pipe 3: bodies 4a to 4h: flow path 5: pipe 5a: first heat pipe 5b: second heat pipe 7: piston 8: pressure transmission section 9, 109: folding section 12, 112: 1st closure member 13, 113: 2nd closure member 14: Cap 31: Spring 47: Diaphragm 48: Frame 57, 157: Elastic body Hr: Heat radiation part Hv: Heat receiving part

Claims (7)

It is a self-excited vibration heat pipe that has a tube that is sealed and bent back multiple times,
A pressure transmitting means for dividing the space in the pipe into one of the folded portions and transmitting the pressure fluctuation of the space on one side to the space on the other side is provided,
A self-excited oscillating heat pipe characterized in that heat transport characteristics differ between the space on one side and the space on the other side of the pressure transmission means. A body in which a plurality of parallel flow paths having both ends open are formed;
A first closing member that covers one end side of the plurality of flow paths, the first closing member that communicates the ends of the two flow paths for each pair of adjacent two flow paths;
A second closing member that covers the other end side of the plurality of flow paths, each of a pair of another two flow paths adjacent to each other so as to alternate with the two flow paths that communicate with the first closing member. A second closing member for communicating the ends of the other two flow paths with respect to
With
2. The self-excited vibration heat pipe according to claim 1, wherein the pressure transmission means is provided inside one of the flow paths and faces the inner surface of the first or second closing member. . A body in which a plurality of parallel flow paths having both ends open are formed;
A first closing member that covers one end side of the plurality of flow paths, the first closing member that communicates the ends of the two flow paths for each pair of adjacent two flow paths;
A second closing member that covers the other end side of the plurality of flow paths, each of a pair of another two flow paths adjacent to each other so as to alternate with the two flow paths that communicate with the first closing member. A second closing member for communicating the ends of the other two flow paths with respect to
With
The self-excited vibration heat pipe according to claim 1, wherein the pressure transmission means is provided in the first or second closing member.   The self-excited vibration heat pipe according to any one of claims 1 to 3, wherein the pressure transmission means is provided in a folded portion on the heat radiation side.   The self-excited vibration heat pipe according to any one of claims 1 to 4, wherein the pressure transmission means is any one of a piston, a diaphragm, and an elastic body that closes the flow path.   6. The self-excited vibration heat pipe according to claim 5, wherein the pressure transmission means includes a piston and a spring that urges the piston toward a space on one side of the divided pipe.   7. The pressure transmission means according to claim 1, wherein at least one of the pipe cross-sectional area, the amount of hydraulic fluid per unit volume of the pipe, the type of hydraulic fluid, and the heat flux is different between the one side and the other side. The self-excited vibration heat pipe according to claim 1.

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