JP2008185322A - Ignition structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat pipe allowing internal vapor pressure to stably leak at a predetermined part even when used at a high temperature in a state of covering a body part of the heat pipe in close contact from the outer peripheral side. <P>SOLUTION: The heat pipe whose total length is mostly inserted in a metal pipe, is composed of a container 3 comprising a body part 4 and approximately hemispherical end parts 5. The container is filled with an operating fluid inside, and provided with a sacrificial preferential breaking part 7 near a boundary part between each end part and the body part. The sacrificial preferential breaking part may be formed from a part of a linear cylindrical part to a part of a hemispherical part or may be formed at a part of the hemispherical part. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a heat equalizing structure in which a heat pipe is inserted into a metal cylindrical tube to prevent an abnormal increase in internal pressure.

  A heat exchanger in which a heat transfer member is arranged around the heat pipe is used. In such a heat exchanger, for example, the heat pipe is inserted into the insertion hole of the heat transfer member having an insertion hole having an inner diameter larger than the outer diameter of the round heat pipe and heated at a predetermined temperature. Is in close contact with the inner wall of the heat transfer member.

A method of inserting a heat pipe into an insertion hole of a heat transfer member is described in Japanese Patent Publication No. 2647291. That is, a heat pipe having a predetermined outer diameter is processed by enclosing an amount of working liquid in a metal container having a first coefficient of thermal expansion so that a liquid phase does not remain at a predetermined heating temperature. A heat transfer member having an insertion hole with an inner diameter larger than the outer diameter of the heat pipe is processed with a metal having a coefficient of thermal expansion greater than the rate, and the heat pipe is inserted into the insertion hole of the heat transfer member, and the whole is subjected to the vapor pressure of the working fluid. Is heated at a temperature equal to or lower than the burst strength of the heat pipe container to plastically deform the heat pipe container, and the heat pipe is brought into close contact with the inner wall of the heat transfer member by this plastic deformation.
An example in which the heat pipe thus manufactured is applied to a motor shaft is disclosed in Japanese Patent Application Laid-Open No. 59-110432.

  A heat pipe evacuates non-condensable gas such as air from the inside of a sealed container, and then injects a fluid that evaporates and condenses at a target temperature, such as water and ammonia, as a working fluid. A wick that generates a capillary pressure such as the above is provided inside a sealed container. Heat is applied to a predetermined part of the heat pipe, the working fluid evaporates by the heat, and the vapor flows to a part where the temperature and pressure are low, dissipates heat and liquefies.

As a result, the heat given to a part of the heat pipe is mainly transported as latent heat of the working fluid. In the portion where the working fluid is condensed, the wick is returned to the original portion, that is, the portion where evaporation occurs due to capillary pressure, gravity and the like. In this way, in a heat pipe, the working fluid circulates and flows while repeatedly evaporating and condensing inside, so that heat transfer is performed as latent heat, so the apparent thermal conductivity is several times that of metals such as copper. It is 10 to several hundred times higher and can function without the need for external power.
Japanese Unexamined Utility Model Publication No. 63-90770 discloses a measure for preventing the heat pipe from bursting due to abnormal temperature rise. That is, a recess is formed on the outer surface of the container, and the formed recess is filled with a low melting point alloy.
Japanese Patent Publication No. 2647291 JP 59-110432 A Japanese Utility Model Publication No. 63-90770

  In the exhaust heat recovery apparatus using a heat pipe disclosed in Japanese Utility Model Publication No. 63-90770, a large number of heat pipes are connected to an intermediate partition plate in a space surrounded by a double-sided box-shaped casing. It is installed in a horizontal state through the side plates at both ends, and the heat pipe evaporating part faces the exhaust passage through which the high-temperature exhaust flows, and the condensing part faces the air supply passage through which the low-temperature air supply flows.

  However, since the low-melting point alloy is filled in the recess formed in the heat pipe container in the exhaust heat recovery apparatus described above, the structure is complicated and the manufacturing process is increased. When used in a state of being covered closely, the pressure is strongly concentrated in the recess, so that the low melting point alloy melted before the container breaks off, and the surrounding equipment is contaminated, the air is contaminated, etc. May occur.

  Accordingly, the object of the present invention is to stably leak the internal vapor pressure at a predetermined location of the container even when the heat pipe is in close contact with the outer peripheral side and used at a high temperature. It is to provide a heat pipe and a soaking structure.

  The inventor has conducted extensive research to solve the above-described conventional problems. As a result, a round heat pipe sealing / welding part is provided instead of reducing the thickness of a part of the main part of the round heat pipe inserted into the metal cylindrical tube in close contact therewith. If a notch is formed in the vicinity of the boundary between the hemispherical terminal and main body, when the pressure inside the container rises above a predetermined pressure, the preset notch is preferentially damaged and stable. Thus, it was found that the pressure inside the container could be prevented from rising abnormally.

In order to release the pressure stably, the notch part and the shape of the notch are important.In particular, it is cut parallel to the tangent of the outer peripheral surface of the terminal part, and the major axis of the body part and the notch surface It has been found that the pressure can be safely released when the formed notch angle is in the range of 0 to 30 degrees. Furthermore, when the notch angle is in the range of 5 to 15 degrees, the leak temperature accuracy is more stable and pressure can be released, and even if there is some variation in the workability of the notch, there is no problem. The pressure can be released, which is preferable.
That is, if a notch (slice) is provided in a part of the outer peripheral surface of the terminal portion at the notch angle in the above-described range, the variation in the fracture position in the slice portion can be reduced and the fracture starts at the center of the slice portion. There was found.
The present invention has been made based on the research results described above.

  According to a first aspect of the heat pipe of the present invention, the heat pipe is inserted into a metal tube substantially in its entire length, and a container constituting the heat pipe includes a main body portion and a substantially hemispherical terminal portion, and the container Is a heat pipe in which a working fluid is sealed and a sacrificial preferential destruction portion is provided in the vicinity of a boundary portion between the terminal portion and the main body portion.

  The 2nd aspect of the heat pipe of this invention is a heat pipe in which the said sacrificial preferential destruction part is provided in the position straddling both the said terminal part and the said main-body part.

  A third aspect of the heat pipe according to the present invention is a heat pipe in which the sacrificial preferential destruction portion is provided only in the terminal portion.

  A fourth aspect of the heat pipe of the present invention is a heat pipe in which the main body has a substantially linear cylindrical shape.

  A fifth aspect of the heat pipe of the present invention is a heat pipe in which the sacrificial preferential destruction portion is formed by a notch formed in a direction substantially perpendicular to a boundary line between the terminal portion and the main body portion.

  A sixth aspect of the heat pipe of the present invention is a heat pipe in which the sacrificial preferential destruction portion is formed by a notch formed in a direction substantially parallel to a tangent to the outer peripheral surface of the terminal portion.

  A seventh aspect of the heat pipe of the present invention is a heat pipe in which an angle between the major axis of the container and the formed notch surface is 0 to 30 degrees.

  The eighth aspect of the heat pipe of the present invention is a heat pipe in which the shape of the sacrificial preferential destruction portion is substantially circular.

  One aspect of the soaking structure according to the present invention is a soaking structure formed by inserting the above-described heat pipe into a metal tube.

  One aspect of the drum of the present invention is a drum for a copying machine, a printing machine, or a textile machine using the soaking structure.

  According to the present invention, a heat pipe (container) can be cut into a predetermined place even when used at a high temperature in a state where the main body of the heat pipe is closely covered from the outer peripheral side without preparing a complicated structure. By only providing a notch, it is possible to reduce the variation in leak temperature when leaking the internal pressure, and to stably release the internal pressure. Since the terminal part is entirely covered with a metal cylindrical tube (the terminal part is not in contact), the leaked working fluid will not scatter to the surroundings. Absent.

Various embodiments of a heat pipe and a soaking structure according to the present invention will be described with reference to the drawings.
One aspect of the heat pipe of the present invention is a heat pipe that is inserted into a metal tube substantially in its entire length, and a container constituting the heat pipe includes a main body portion and a substantially hemispherical terminal portion, It is a heat pipe in which a working fluid is sealed and a sacrificial preferential destruction portion is provided in the vicinity of a boundary portion between the terminal portion and the main body portion. The main body may be linear, and may have a curved shape or a bent portion.

FIG. 1 is a cross-sectional view for explaining one embodiment of a soaking structure provided with a heat pipe of the present invention. As shown in FIG. 1A, the heat equalizing structure 1 of the present invention includes a round heat pipe 3 (which may have a flat portion) and a metal cylindrical tube 2. A container 3 having a linear (which may be bent) main body 4 and a terminal 5 formed at the end of the main body is inserted into the metal cylindrical tube 2. In addition to the welded portion for sealing, the terminal portion may have a dent or the like. The heat pipe and the metal cylindrical tube may be brought into close contact with each other by expansion, or heat conductive rubber or grease may be interposed. The insertion is performed in such a manner that the entire container fits in a metal cylindrical tube. That is, the terminal portion 5 and the sealing / welding portion 6 formed at the center tip portion are completely accommodated in the cylindrical tube 2. The container 3 and the cylindrical tube 2 are in a state in which the main body of the container is closely covered from the outer peripheral side so that heat conduction is good. In addition, in order to improve the adhesion effect, a heat transfer material may be interposed therebetween.
FIG. 1B shows, as an example, a linear main body portion 4 of a container and a terminal portion 5 formed on a terminal of the main body portion.

FIG. 2 is a diagram for explaining the state of pressure in the container. As shown in FIG. 2, a pressure of σ 2 − = pR / t works in the vertical direction in the main body. In the horizontal direction in the main body, a pressure of σ1 = pR / 2t works. A pressure of σR = pR / 2t is applied to the terminal portion.
When the linear main body portion does not cover the outer peripheral portion, the vertical pressure σ2− = pR / t in the main body portion becomes the largest, and the main body portion is damaged due to abnormal temperature rise. Therefore, the possibility that the broken pieces are scattered is low. In addition, the symbol of the above-mentioned stress formula means P: pressure, R: radius, and t: wall thickness.

  On the other hand, when the linear main body is covered with its outer peripheral portion in close contact, it is reinforced by a metal cylindrical tube covering the outer peripheral portion, so that the vertical pressure σ2 in the main body portion. -= PR / t is reduced, and the horizontal pressure σ1 = pR / 2t in the main body portion or the pressure σR = pR / 2t in the terminal portion becomes larger, and damage is caused by these pressures. However, since the wall thickness t of the terminal portion increases in processing the container, the horizontal pressure σ1 = pR / 2t in the main body portion is larger than the pressure σR = pR / 2t of the terminal portion, and the inside of the main body portion is increased. There is a possibility that the terminal portion is broken and scattered by the horizontal pressure σ1 = pR / 2t.

Therefore, as a sacrificial preferential destruction part, instead of a linear main body part, a thin part is formed at the terminal part, and even when covered with a metal cylindrical tube that complements the strength of the heat pipe (container), It is important to destroy it safely. Even if the sacrificial preferential destruction part is formed on the straight body part, the outer peripheral part is reinforced by a metal cylindrical tube, so even if the pressure rises due to abnormal temperature rise, the sacrificial preferential destruction part A state occurs where no destruction occurs.
The soaking structure of the present invention includes a sacrificial preferential destruction portion formed at and / or near the terminal portion of the container.

  In the soaking structure of the present invention, the container is inserted and mounted in an outer peripheral member longer than the container, for example, a metal cylindrical tube, and used at a temperature of 200 ° C. or more for the purpose of soaking the outer peripheral member. The terminal portions at both ends of the linear body portion are generally hemispherical, and have a manufacturing sealing portion at the center tip of the terminal portion, and the linear body portion has a certain thickness. ing. When leaking the internal pressure by applying at least one notch of a predetermined notch shape that is continuous over a part of the end part of the heat pipe or a part of the end part and a part of the linear main body in the vicinity thereof. Reduce variation in leakage temperature.

  FIG. 3 is a cross-sectional view illustrating one embodiment of the sacrificial preferential destruction portion. As shown in FIG. 3, in this embodiment, a sacrificial preferential destruction portion is formed by continuously cutting a part of the terminal part and a part of the linear main body part substantially parallel to the axis of the heat pipe. is doing. This aspect is suitable when performing breakage leakage at a temperature of 200 ° C. to 300 ° C. This embodiment can also be used at a temperature of 200 ° C. or lower.

  FIG. 4 is a cross-sectional view illustrating another embodiment of the sacrificial preferential destruction portion. As shown in FIG. 4, in this embodiment, a sacrificial preferential destruction portion is formed by cutting a part of the terminal portion in the vicinity of the linear main body portion. That is, it cuts in parallel to the tangent line of the outer peripheral surface of the terminal portion. The cut shape is circular. This aspect is suitable when a breakage leak is performed at a temperature of 300 ° C. to 400 ° C. In particular, it has the effect of reducing the variation in leak temperature.

  Details of this embodiment are shown in FIG. As shown in FIG. 6, a notch thickness is formed on the curved surface outside the terminal portion 5 in the vicinity of the boundary between the linear main body portion 4 and the terminal portion 5 with the major axis direction of the main body portion and a predetermined notch angle (θ). Make a cut with to. The shape of the cut portion is generally circular, but a part of the cutout extends over the cylindrical body. The notch angle may be in the range of 0 to 30 degrees, and more preferably in the range of 5 to 15 degrees. In particular, when the notch angle is about 10 degrees, it is possible to reduce the variation in the leak temperature when leaking the internal pressure, and to stably release the pressure. In the present invention, as described above, by merely providing a notch at a predetermined place of the heat pipe (container), the variation in the leak temperature when leaking the internal pressure is reduced, and the internal pressure is stably maintained. Can be removed.

In addition, since the entire terminal including the terminal is covered with a metal cylindrical tube (the terminal is not in contact), the leaked working fluid does not scatter around and contaminates peripheral devices. There is nothing.
In addition, this aspect, when the thickness changes at the terminal portion and the thickness is constant, and when the terminal portion is formed by drawing or the like, the thickness is not constant, and when the thickness increases toward the tip, Is suitable.

  FIG. 5 is a cross-sectional view illustrating another embodiment of the sacrificial preferential destruction portion. As shown in FIG. 5, a notch 7 is formed on the curved surface outside the terminal portion 5 near the boundary between the linear body portion 4 and the terminal portion 5 by performing a notch process in parallel with the axis of the body portion. ing. This aspect is suitable when a breakage leak is performed at a temperature of 300 ° C. to 400 ° C. Furthermore, it is suitable when the thickness changes at the terminal portion and the thickness is constant.

FIG. 7 is a cross-sectional view of the tip of one heat pipe. This aspect shows a state in which the terminal portion is formed by drawing or the like and the thickness is not constant, and is thicker toward the tip.
The soaking structure according to the present invention is a soaking structure formed by inserting the above-described heat pipe into a metal tube. The drum of the present invention is a drum for a copying machine, a printing machine or a textile machine using the above-described soaking structure. The drum is also called a roller.
It should be noted that the soaking structure is often used when the roll itself rotates in use, but may not be rotated. Further, it may be a soaking plate having an HP flat caulking structure or a case where a metal pipe covers only one part of the HP.

  In the soaking structure of the present invention, it is important to release the internal pressure more stably at the notch by reducing the variation in the leak temperature when the internal pressure leaks. In the heat equalizing structure according to the present invention, as described above, a sacrificial preferential destruction portion is formed by continuously cutting a part of the terminal part and a part of the linear body part, or a linear shape. In the curved surface outside the terminal portion 5 near the boundary between the main body portion 4 and the terminal portion 5, an incision is made with a notch thickness at a predetermined cutting angle with the major axis direction of the main body portion to form a sacrificial preferential destruction portion. As it forms, destruction begins in the middle of the cutout.

  According to the present invention, even when used at a high temperature in a state where the main body portion of the heat pipe is closely covered from the outer peripheral side without preparing a complicated structure, the heat pipe (container) is cut into a predetermined place. It is possible to reduce the variation in the leak temperature when leaking the internal pressure, and to stably release the internal pressure. Since the terminal part is entirely covered with a metal cylindrical tube (the terminal part is not in contact), the leaked working fluid will not scatter to the surroundings. Absent.

FIG. 1 is a cross-sectional view illustrating one embodiment of a heat equalizing structure according to the present invention. FIG. 2 is a diagram for explaining the state of pressure in the container. FIG. 3 is a cross-sectional view illustrating one embodiment of the sacrificial preferential destruction portion. FIG. 4 is a cross-sectional view illustrating another embodiment of the sacrificial preferential destruction portion. FIG. 5 is a cross-sectional view illustrating another embodiment of the sacrificial preferential destruction portion. FIG. 6 is a diagram for explaining details of another embodiment of the sacrificial preferential destruction portion of the present invention shown in FIG. It is sectional drawing of the front-end | tip part of a heat pipe.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Soaking | uniform-heating structure of this invention 2 Metal cylindrical tube 3 Heat pipe (container)
4 Body part 5 Terminal part 6 Sealing / welding part 7 Notch part

Claims (10)

  A heat pipe having a substantially full length inserted into a metal tube, wherein a container constituting the heat pipe includes a main body part and a substantially hemispherical terminal part, and a working fluid is sealed in the container, and the terminal The heat pipe which provided the sacrificial preferential destruction part in the boundary part vicinity of a part and the said main-body part.   2. The heat pipe according to claim 1, wherein the sacrificial preferential destruction portion is provided at a position straddling both the terminal portion and the main body portion.   The heat pipe according to claim 1, wherein the sacrificial preferential destruction portion is provided only in the terminal portion.   The heat pipe according to any one of claims 1 to 3, wherein the main body has a substantially linear cylindrical shape.   The heat pipe according to any one of claims 1 to 4, wherein the sacrificial preferential destruction portion is formed by a notch formed in a direction substantially perpendicular to a boundary line between the terminal portion and the main body portion.   The heat pipe according to any one of claims 1 to 5, wherein the sacrificial preferential destruction portion is formed by a notch formed in a direction substantially parallel to a tangent to the outer peripheral surface of the terminal portion.   The heat pipe according to any one of claims 1 to 6, wherein an angle between the major axis of the container and the formed notch surface is 0 to 30 degrees.   The heat pipe according to any one of claims 1 to 7, wherein the shape of the sacrificial preferential destruction portion is substantially circular.   A heat equalizing structure formed by inserting the heat pipe according to any one of claims 1 to 8 into a metal tube. A drum for a copying machine, a printing machine or a textile machine using the soaking structure according to claim 9.

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