JP2014157007A - Self-excited vibration type heat pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a self-excited vibration type heat pipe enhanced in starting characteristics at a low-temperature time.SOLUTION: A self-excited vibration type heat pipe comprises pressure transmission means which is disposed midway of a sealed pipe for transmitting a pressure fluctuation in one-side space to the other-side space. Moreover, the pressure transmission means is given different heat transport characteristics on one side and the other side thereof. The one-side heat pipe (or the first heat pipe) is constituted to have a lower heat transport amount but a more excellent low-temperature responsiveness than those of the other-side heat pipe (or the second heat pipe). The first heat pipe is started earlier in a low-temperature environment than the second heat pipe. Moreover, the vibration of the first heat pipe is transmitted to the second heat pipe by the pressure transmission means. The pressure vibration transmitted induces the self-excited vibration of the second heat pipe so that the self-excited vibration is started earlier than the case of the single second heat pipe.

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 tubule is reciprocated many times and a highly volatile liquid (working fluid) is enclosed therein. A heat source is attached near one end of the narrow tubes arranged in parallel. 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 in the narrow tube, the entire thin tube is in a state where a gas phase and a liquid phase are alternately present. 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.

  The characteristics of the self-excited vibration heat pipe 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. Responsiveness (startability at low temperatures) is 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, a pulse voltage is locally applied to the tube, bubbles are generated in the hydraulic fluid, and self-excited vibration is induced. Furthermore, in patent document 3, a vibration is given to hydraulic fluid with the shaker (actuator) driven electrically. The heat pipe of Patent Document 4 includes means for adjusting the amount of hydraulic fluid.

  Further, in Patent Document 5, 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 2004-179534 A JP 2002-195789 A JP 2007-333246 A JP 2009-260058 A

  Each of the heat pipes of Patent Documents 1 to 4 includes some kind of 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. The present specification provides a heat pipe with improved characteristics at low temperatures without requiring an active driving force such as a power source.

  The self-excited oscillating heat pipe disclosed in the present specification includes pressure transmission means for transmitting pressure fluctuations while gas and liquid do not pass through a sealed tube. And the heat transport characteristic which is different in the one side and the other side of the pressure transmission means of a pipe | tube is given. In other words, the self-excited oscillating heat pipe disclosed in this specification is a pressure transmission means that transmits pressure fluctuations while gas and liquid do not pass through the first heat pipe and the second heat pipe having different heat transport characteristics. It is a device connected with. The heat transport property includes good startability at low temperatures. In other words, the self-excited vibration heat pipe disclosed in the present specification has a space in the heat pipe divided into two in the length direction, and a pressure fluctuation generated in one of the divided spaces. Pressure transmitting means for transmitting to the other space is provided. As described above, the heat transport 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 amount of heat transport than the second heat pipe, but the response at low temperatures. It is configured so that the characteristics are 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. That is, by making the heat transport characteristics different on one side and the other side of the pressure transmission means, one side starts self-excited vibration at a lower temperature than the other side.

  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.

  Furthermore, in the heat pipe disclosed in the present specification, it is preferable that the coefficient of thermal expansion of the inner diameter of the pipe is larger than the coefficient of thermal expansion of the outer diameter of the pressure transmission means corresponding to the inner diameter. When the pressure transmission means is a piston, the coefficient of thermal expansion of the outer diameter of the piston is preferably smaller than the coefficient of thermal expansion of the inner diameter of the pipe on which the piston slides. Then, when the heat pipe that is easier to start (first heat pipe) starts, the sliding resistance (first sliding resistance) between the piston and the pipe is large, and the heat pipe having the larger heat capacity (second heat pipe). The sliding resistance (second sliding resistance) between the piston and the pipe when the heat pipe is started can be reduced (first sliding resistance> second sliding resistance). This configuration makes it difficult for the piston to move when the first heat pipe is started (that is, without relaxing the pressure fluctuation due to the movement of the piston), and makes it easy to start the first heat pipe. It is possible to facilitate the movement of the piston as it rises, and promote the transmission of pressure fluctuations to the second heat pipe.

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

It is a typical top view 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 flux. It is a figure explaining the manufacturing method of a heat pipe. It is sectional drawing in the IV-IV line of FIG. It is a typical top view which shows the structure of the heat pipe of 2nd Example. It is sectional drawing explaining the difference in the thermal expansion coefficient of a pipe | tube and a piston (1). 6A shows the case where the temperature is low, and FIG. 6B shows the case where the temperature is high. It is sectional drawing explaining the difference in the thermal expansion coefficient of a pipe | tube and a piston (2). 7A shows a case where the temperature is low, and FIG. 7B shows a case where the temperature is high.

  (First Embodiment) FIG. 1 shows a schematic plan view of a heat pipe 2 of the first embodiment. The heat pipe 2 is a device in which a sealed tube 4 is formed inside a flat housing 3. The pipe 4 is filled with a small amount of hydraulic fluid. The hydraulic fluid is a highly volatile liquid, for example, an alternative chlorofluorocarbon.

  The entire housing is made of a metal with high thermal conductivity, such as aluminum or copper. The tube 4 reciprocates a plurality of times between one end and the other end of the housing 3 (upper and lower ends in the figure). A region where a plurality of folded portions of the tube 4 are arranged on one end side of the housing 3 is referred to as a heat receiving portion Hv, and a region where the plurality of folded portions of the tube 4 are arranged on the other end side is referred to as a heat radiating portion Hr. 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 of the tube 4, 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 4. 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 4. The heat source is not limited, but is typically an electronic device such as a semiconductor chip.

  A pressure transmission portion 8 is provided in the middle of the tube 4. The pressure transmitting portion 8 has a structure in which a piston 6 is disposed between two constricted portions 7. The piston 6 can move freely between the two constricted portions 7. However, sealing oil is filled between the piston 6 and the inner wall of the pipe 4, and liquid and gas cannot pass through one side and the other side of the piston 6. When pressure fluctuation occurs on one side of the pipe 4 with the piston 6 as a boundary, the piston 6 reciprocates according to the pressure fluctuation. The reciprocating motion of the piston 6 causes a pressure fluctuation on the other side of the tube 4. That is, the pressure transmission unit 8 does not allow gas and liquid to pass through on one side and the other side of the piston 6 but transmits pressure fluctuations. Hereinafter, one side of the piston 6 in the pipe 4 is referred to as a first heat pipe 4a, and the other side is referred to as a second heat pipe 4b. In other words, in the heat pipe 2, the internal space of the pipe 4 is divided into two in the length direction, and a piston 6 is provided at the divided position. The piston 6 transmits the pressure fluctuation generated in one of the divided spaces to the other space.

  The first heat pipe 4a and the second heat pipe 4b 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 4a is smaller than the amount of hydraulic fluid in the second heat pipe 4b. Therefore, the first heat pipe 4a starts to operate even with a small amount of heat compared to the second heat pipe 4b. In other words, the first heat pipe 4a starts at a low temperature earlier than the second heat pipe 4b.

  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 flux 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 flux corresponds to the amount of heat that passes through a unit area per unit time. The lower right region of the graph of FIG. 2 indicates that the performance of the heat pipe, that is, the heat transport capability is higher. Graph G1 shows the characteristics of the first heat pipe 4a, and graph G2 shows the characteristics of the second heat pipe 4b. The second heat pipe 4b has a lower thermal resistance in the region where the heat flux is larger than the first heat pipe 4a. That is, the heat transport capacity of the second heat pipe 4b is higher than that of the first heat pipe 4a. However, when the outside air temperature is low or when the heat generation amount of the heat source is small, the heat flux 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 4a has a lower thermal resistance than the second heat pipe 4b. This indicates that the first heat pipe 4a is easier to operate than the second heat pipe 4b 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 4a has better startability at a lower temperature than the second heat pipe 4b, but the heat transport amount when the heat generation amount of the heat source becomes larger is the second heat pipe 4a than the first heat pipe 4a. The heat pipe 4b is larger.

  The function of the pressure transmission part 8 is demonstrated. As described above, in the heat pipe 2, the first heat pipe 4a starts before the second heat pipe 4b. That is, vaporization of the hydraulic fluid starts first in the first heat pipe 4a, and self-excited vibration starts. The pressure change due to the self-excited vibration is transmitted to the inside of the second heat pipe 4b through the pressure transmission unit 8. In the second heat pipe 4b, the pressure fluctuation from the first heat pipe 4a stimulates the hydraulic fluid, and self-excited vibration is induced. In this way, even if the single heat pipe equivalent to the second heat pipe 4b is a region where the self-excited vibration does not normally start, the second heat pipe 4b starts to operate due to stimulation from the first heat pipe 4a. The heat pipe 2 has better startability at low temperatures than the two separate heat pipes equivalent to the first heat pipe 4a and the second heat pipe 4b.

  An example of the manufacturing method of the heat pipe 2 of 1st Example is demonstrated. FIG. 3 is a diagram for explaining the manufacturing method. The flat plate-type heat pipe 2 can be made using a multi-hole tube made by extrusion molding of aluminum. The member indicated by reference numeral 33 in FIG. 3 is a multi-hole tube. The multi-hole tube has a plurality of through holes 34 extending in parallel. In FIG. 3, only one through hole is shown by a hidden line, and the other through holes are not shown. After arranging the piston 6 inside one through hole 34, a punch 36 is driven from the outside of the multi-hole 33 toward the through hole 34 on both sides of the piston. A reference numeral 35 indicates a hit point of the punch 36.

  FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. FIG. 4 is a partial cross-sectional view of the periphery of the piston 6. A recess 7 is formed in the inner wall of the through hole 34 inside the hit point 35 of the punch 36. The two recesses 7 define a range in which the piston 6 can move. In this way, the pressure transmission part 8 composed of the recess 7 and the piston 6 is formed. After the pressure transmission part 8 is formed and filled with a small amount of hydraulic fluid, both ends of the plurality of through holes 34 arranged in parallel are closed. At this time, communication between adjacent through holes is ensured inside the housing. Further, the sets of through holes to be communicated with each other are staggered on one end side and the other end side of the housing. Specifically, assuming that the through holes A, B, and C are aligned, the through holes A and B communicate with one end side of the housing, and the through holes B and C communicate with the other end side. Thus, one sealed tube having a pressure transmission part in the middle is obtained while reciprocating between the both ends of the casing a plurality of times. In FIG. 4, the upper side of the pressure transmission unit 8 corresponds to the first heat pipe 4a, and the lower side of the pressure transmission unit 8 corresponds to the second heat pipe 4b.

  (Second Embodiment) A heat pipe 22 of the second embodiment will be described with reference to FIG. In the heat pipe 22, one sealed pipe 14 is divided into a first heat pipe 14 a and a second heat pipe 14 b by the pressure transmission unit 18. The pressure transmission unit 18 is a diaphragm 17 (diaphragm). The diaphragm 17 vibrates due to pressure fluctuation, but does not allow gas and liquid to pass through. That is, the diaphragm 17 transmits the pressure fluctuation (self-excited vibration) generated in one of the first heat pipe 14a and the second heat pipe 14b to the other. The diaphragm 17 has the same effect as the pressure transmission unit 8 of the first embodiment.

  In the heat pipe 22, the first heat pipe 14a and the second heat pipe 14b have different tube cross-sectional areas. The tube cross-sectional area W1 of the first heat pipe 14a is smaller than the tube cross-sectional area W2 of the second heat pipe 14b. Therefore, the first heat pipe 14a has a smaller thermal resistance than the second heat pipe 14b, and the starting at a low temperature is quicker. Accordingly, the first heat pipe 14a starts before the second heat pipe 14b in a low temperature environment or when the heat generation amount of the heat source is small. Then, the pressure fluctuation due to the self-excited vibration of the first heat pipe 14 a is propagated to the second heat pipe 14 b through the diaphragm 17. Inspired by pressure fluctuations received from the first heat pipe 14a via the diaphragm 17, self-excited vibration is likely to occur in the second heat pipe 14b. That is, the second heat pipe 14b is started earlier than a single heat pipe equivalent thereto.

  Next, when the pressure transmission part 8 is comprised with the piston 6, the difference in the thermal expansion coefficient of the internal diameter of the pipe | tube 3 and the external shape of the piston 6 is demonstrated. FIG. 6 is a partial enlarged cross-sectional view schematically showing the difference between the inner diameter Wa of the pipe 3 and the outer diameter Wb2 of the piston 6 in the heat pipe 2 of the first embodiment. FIG. 6A shows the relationship between the inner diameter Wa1 and the outer diameter Wb1 at the temperature at which the first heat pipe 4a is scheduled to start. FIG. 6B shows the relationship between the inner diameter Wa2 and the outer diameter Wb2 at the temperature at which the second heat pipe 4b is scheduled to start. In other words, FIG. 6B shows a case where the temperature is higher than in the case of FIG.

In the description here, the coefficient of thermal expansion of the inner diameter Wa of the pipe 3 is larger than the coefficient of thermal expansion of the outer diameter Wb of the piston 6, in other words, the coefficient of thermal expansion of the outer diameter Wb of the piston 6 is 3 is smaller than the thermal expansion coefficient Wa. The tube 3 is made of aluminum, for example, and the piston 6 is made of copper, for example. The linear expansion coefficient of aluminum is 23.0 [x10 ⁻⁶ / K], the linear expansion coefficient of copper is 16.7 [x10 ⁻⁶ / K], and the linear expansion coefficient of aluminum is greater than the linear expansion coefficient of copper. Is also expensive. If there is such a difference in linear thermal expansion coefficient, the thermal expansion coefficient of the inner diameter Wa of the tube 3 is larger than the thermal expansion coefficient of the outer diameter Wb of the piston 6.

  In the case of FIG. 6A, the inner diameter Wa1 of the tube 3 and the outer diameter Wb1 of the piston 6 are substantially equal. Therefore, the piston 6 receives a high sliding resistance between the inner wall of the pipe 3. When the first heat pipe 4a starts to operate (when self-excited vibration starts in the first non-heat pipe 4a), the piston 6 does not move. When the piston 6 moves, the pressure fluctuation in the first heat pipe 4a is alleviated and inhibits the start of self-excited vibration. However, in the case of FIG. 6A, since the piston 6 does not move, such inhibition does not occur. .

  When the temperature rises and reaches the temperature at which the second heat pipe 4b is scheduled to start (in the case of FIG. 6B), the inner diameter Wa1 of the tube 3 expands to Wa2, and the outer diameter Wb1 of the piston 6 expands to Wb2. Since the thermal expansion coefficient of the inner diameter Wa of the pipe 3 is larger than the thermal expansion coefficient of the outer diameter Wb of the piston 6, the inner diameter Wa2 of the pipe 3> the outer diameter Wb2 of the piston 6. Therefore, the sliding resistance that the piston 6 receives from the inner wall of the pipe 3 is lowered, and the piston 6 becomes easy to move. When the temperature rises to the temperature range where the second heat pipe 4b is scheduled to start, the piston 6 starts to move, and the vibration of the first heat pipe 4a is transmitted to the second heat pipe 4b. The second heat pipe 4b receives a pressure fluctuation from the first heat pipe 4a via the piston 6, and the start of operation is induced. In FIG. 6B, a gap is drawn between the piston 6 and the inner surface of the pipe 3 to help understanding. Actually, however, the piston 6 has the first heat pipe 4a and the second heat pipe 4b. Neither gas nor liquid can pass between them. The same applies to FIG. 7B.

  FIG. 7 shows a case where a rubber seal ring 41 is attached around the piston 6. Also in the case of FIG. 7, if the difference between the thermal expansion coefficient of the inner diameter of the tube 3 and the thermal expansion coefficient of the outer diameter of the piston 6 is the same as in FIG. 6, the same advantages as in FIG.

  Similar to FIG. 6, FIG. 7A shows the relationship between the inner diameter Wa1 and the outer diameter Wc1 at the temperature at which the first heat pipe 4a is scheduled to start. FIG. 7B shows the relationship between the inner diameter Wa2 and the outer diameter Wc2 at the temperature at which the second heat pipe 4b is scheduled to start.

  When the temperature at which the first heat pipe 4a is scheduled to start (in FIG. 7A), the difference between the inner diameter Wa1 of the pipe 3 and the outer diameter Wc1 of the piston 6 (Wa1-Wc1) Small enough to squeeze strongly. Therefore, the piston 6 receives a high sliding resistance between the inner wall of the pipe 3. When the first heat pipe 4a starts to operate (when self-excited vibration starts in the first non-heat pipe 4a), the piston 6 does not move and the first heat pipe 4a starts smoothly.

  When the temperature rises and reaches the temperature at which the second heat pipe 4b is scheduled to start (in the case of FIG. 7B), the inner diameter Wa1 of the tube 3 expands to Wa2, and the outer diameter Wc1 of the piston 6 expands to Wc2. Since the coefficient of thermal expansion of the inner diameter Wa of the pipe 3 is larger than the coefficient of thermal expansion of the outer diameter Wc of the piston 6, the difference (Wa2-Wc2) between the inner diameter Wa of the pipe 3 and the outer diameter Wc2 of the piston 6 is lower than that at low temperature. Also spread. That is, (Wa2-Wc2)> (Wa1-Wc1). Therefore, the compressive force applied to the seal ring 41 is weakened, and the sliding resistance that the piston 6 receives from the inner wall of the pipe 3 is lowered. As a result, the piston 6 becomes easy to move. The same effect as in the case of FIG. 6 is obtained.

  As described above, if the material of the pipe 3 and the piston 6 is selected so that the thermal expansion coefficient of the inner diameter of the pipe 3 is larger than the thermal expansion coefficient of the outer diameter of the piston 6 corresponding to the inner diameter, the temperature can be reduced. It becomes easier to start the first heat pipe 4a.

  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 heat pipe of the embodiment, in particular, the heat pipe 2 of the first embodiment can be easily manufactured using the multi-hole. The heat pipe disclosed in this specification has an advantage that not only an actuator is unnecessary, but also its manufacture is easy. In addition, in the manufacturing method demonstrated in the Example, the punch was applied only from the single side | surface of the multi-hole pipe | tube, and the constriction part was provided in the one surface in a pipe | tube. It is also preferable to provide a constricted portion on both sides of the cross section in the tube by applying a punch from both sides of the multi-hole tube.

  In the first embodiment, the amount of hydraulic fluid is different between the first heat pipe and the second heat pipe. In the second embodiment, the first heat pipe and the second heat pipe have different tube cross-sectional areas. The first heat pipe and the second heat pipe need only have different heat transport characteristics, and are not limited to the amount of hydraulic fluid or the cross-sectional area. 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 flux, and the like. In addition, the housings 3 of the heat pipes 2 and 22 of the examples were both flat plate types. 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 example, the heat transport capability of the first heat pipe is higher than the heat transport capability of the second heat pipe. It is desirable that the space (typically length) occupied by the first heat pipe having a high heat transport 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, 22: heat pipe 3: housing 4: pipe 4a, 14a: first heat pipe 4b, 14b: second heat pipe 6: piston 7: constricted part 8, 18: pressure transmission part 17: diaphragm 33: multi-hole Hole 34: Through hole 36: Punch 39: Spot 41: Seal ring Hr: Heat radiation part Hv: Heat receiving part W1, W2: Pipe cross-sectional area

Claims (4)

  In the middle of the sealed pipe, there is provided pressure transmission means for dividing the space in the pipe and transmitting pressure fluctuations in the space on one side to the space on the other side, and heat is applied to one side and the other side of the pressure transmission means. A self-excited vibration heat pipe characterized in that self-excited vibration is started at a low temperature on one side compared to the other side by different transport characteristics.   2. The self-excited vibration heat pipe according to claim 1, wherein the pressure transmission means is a piston or a diaphragm.   The 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 differs between one side and the other side of the pressure transmission means. Self-excited vibration heat pipe.   The self-excited vibration type according to any one of claims 1 to 3, wherein the coefficient of thermal expansion of the inner diameter of the tube is larger than the coefficient of thermal expansion of the outer diameter of the pressure transmission means corresponding to the inner diameter. heat pipe.

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