JP2019071706A - Magnetic fluid heat engine and device mounting the same - Google Patents

Abstract

To provide a structure for improving power conversion efficiency of a magnetic fluid heat engine.SOLUTION: A magnetic fluid heat engine comprises: magnetic fluid; a circulation passage of the magnetic fluid; a magnetic field application section arranged in the middle of the circulation passage; a heat receiving section and a non-heat receiving section, which are arranged in the magnetic field application section; a heat source connected to the heat receiving section; and magnetic field application means for applying a magnetic field to the magnetic field application section. The heat receiving section, the non-heat receiving section and the magnetic field application means are arranged so that driving force is generated in a direction where a value of an internal product of a vector becomes at least negative with respect to resultant force vector of gravity applied to the magnetic fluid in the heat receiving section and inertial force.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a magnetic fluid heat engine and an apparatus equipped with the magnetic fluid heat engine, and more particularly to a configuration of a power converter of the magnetic fluid heat engine.

  A magnetic fluid heat engine has been proposed that circulates the magnetic fluid in the circulation channel by thermal energy. For example, in Patent Document 1, after a magnetic field is generated by a magnetic field application unit in a part of a circulation flow path, a temperature gradient is generated in a magnetic fluid in the magnetic field by a heating unit to make this part a power conversion unit. An arrangement for circulating the

Japanese Patent Application Publication No. 01-012852

  Heretofore, the influence of gravity on the power conversion efficiency of the above-mentioned magnetic fluid heat engine has not been mentioned. Therefore, there was a problem that a guideline for arranging the magnetic fluid heat engine in the device was not clear.

  Therefore, the present invention aims to clarify the influence of gravity on the power conversion efficiency of a magnetic fluid heat engine and to enhance the power conversion efficiency.

  In order to achieve the above object, according to the present invention, a magnetic fluid, a circulation channel of the magnetic fluid, a magnetic field application unit disposed in the middle of the circulation channel, and a heat receiving unit disposed in the magnetic field application unit And a non-heat receiving portion, a heat source connected to the heat receiving portion, and a magnetic field applying means for applying a magnetic field to the magnetic field applying portion, and the combined force vector of gravity and inertial force acting on the magnetic fluid in the heat receiving portion. The magnetic fluid heat engine is characterized in that the heat receiving portion, the non-heat receiving portion, and the magnetic field applying means are arranged so as to generate driving force in such a direction that the value of the inner product of the vector becomes negative.

  According to the present invention, the power conversion efficiency of the magnetic fluid heat engine can be enhanced.

The schematic diagram which shows the notional structure of a magnetic fluid heat engine. The schematic diagram of the motive power conversion part of a magnetic fluid heat engine. The schematic diagram which shows the application example of the motive power conversion part of a magnetic fluid heat engine. FIG. 1 is a schematic view of a lens-interchangeable digital camera according to a first embodiment. FIG. 5 is a schematic view showing coordinate definition in the interchangeable-lens type digital camera in the first embodiment. The schematic diagram which shows the range which the driving force vector in a 1st Example should take. The schematic diagram which shows the determination method of the representation gravity vector in a 1st Example. The schematic diagram of the liquid crystal projector in 2nd Example. FIG. 7 is a schematic view showing a typical use posture of the liquid crystal projector in the second embodiment. FIG. 13 is a schematic view showing a first example of the configuration of the power conversion unit of the magnetic fluid heat engine in the liquid crystal projector in the second embodiment. FIG. 13 is a schematic view showing a second example of the configuration of the power conversion unit of the magnetic fluid heat engine in the liquid crystal projector in the second embodiment. The schematic diagram which shows the structural example of the switching means of the heat conduction direction in 2nd Example.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. FIG. 1 is a schematic view showing a conceptual configuration of a magnetic fluid heat engine. In FIG. 1, 100 is a magnetic fluid heat engine, 101 is a magnetic fluid, 102 is a circulation flow path of magnetic fluid 101, 103 is a magnetic field application means, 104 is a heat source, 105 is a work means, 106 is a heat dissipation The means are shown respectively. Further, 102a indicates a magnetic field application unit in the circulation flow path 102, 102b indicates a heat receiving unit in the magnetic field application unit 102a, and 102c indicates a non-heat receiving unit in the magnetic field application unit 102a. In addition, a power conversion unit of the magnetic fluid heat engine 100 is shown as a generic term of a portion including the magnetic field application unit 103, the heat source 104, and the magnetic field application unit 102a of the circulation channel 102 surrounded by a dotted line.

  The arrows 108b and 108c indicate typical directions and magnitudes of the magnetic body force acting on the magnetic fluid 101 in the heat receiving portion 102b and the non-heat receiving portion 102c of the circulation flow path 102, and the arrows 108 indicate their forces. Indicates the driving force as a resultant force of The other arrows indicate the direction in which the magnetic fluid 101 flows in the circulation channel 102. The same arrows hereinafter indicate the flow direction of the magnetic fluid.

  The magnetic fluid heat engine is an engine that converts the heat energy of the heat source into kinetic energy of the magnetic fluid in the power conversion unit. Magnetic fluid heat engines have a variety of applications. For example, when a heating means is used as a heat source, it can be used as a liquid delivery apparatus (pump) which performs work by work means. Since this pump does not have a movable part, it does not generate noise or vibration, and there is no mechanical seal, so it has an excellent feature that there is no problem of durability, leakage, mixing of foreign matter, and the like.

  In addition, when an electronic component to be dissipated is used as a heat source, it can be used as a self-circulating liquid cooling system that circulates a magnetic fluid by the heat, transports the heat to the heat dissipation means, and dissipates the heat. This liquid cooling system is power saving because it does not require a separate power supply, and has an excellent feature that it does not generate extra heat.

  The principle of power conversion in the magnetic fluid heat engine is disclosed in the prior art, and therefore will not be described in detail and will be briefly described. First, the magnetic field application unit 102 a is provided in a part of the circulation flow path 102 filled with the magnetic fluid 101, and a magnetic field is generated by the magnetic field application unit 103 inside thereof. At this time, approximately half the area of the magnetic field application section is the heat receiving section 102b, and the other area is the non-heat receiving section 102c, and in these areas, magnetic fields are generated along the flow path direction and facing each other. .

  That is, the direction of the magnetic field in each region is made to be the direction in which the magnetic fluid 101 inside is attracted to the other region (magnetic volume forces 108 b and 108 c in the flow direction).

  Next, heat is applied to the heat receiving portion 102b by the heat source 104 to raise the temperature of the magnetic fluid 101 inside. Then, since the magnetic fluid 101 becomes less magnetic by temperature sensitivity, the magnetic volume force 108 b received from the magnetic field also becomes weaker. As a result, the balance of the magnetic body force between the magnetic fluid in the heat receiving portion 102b and the magnetic fluid in the non-heat receiving portion 102c in the magnetic field applying portion 102a is broken, so that the magnetic fluid flows from the non heat receiving portion toward the heat receiving portion. A moving force (driving force 108) is generated. Power conversion is performed according to the above principle, and the magnetic fluid 101 circulates in the circulation flow channel 102 by continuously propagating in the magnetic fluid 101.

  Based on the above principle, the influence of gravity on the power conversion efficiency of the magnetic fluid heat engine 100 can be considered as follows.

  FIG. 2 is a schematic view showing a detailed configuration of the power conversion unit 107 of the magnetic fluid heat engine 100. As shown in FIG. In FIG. 2, reference numerals 103a and 103b respectively indicate a magnet and a yoke which constitute the magnetic field applying means 103. The arrow 109 indicates the buoyancy acting on the magnetic fluid 101 in the heat receiving portion 102b.

  In the magnetic fluid heat engine 100, when the temperature of the magnetic fluid 101 in the heat receiving portion 102b is increased, the density of the magnetic fluid locally decreases in the heat receiving portion 102b while the driving force 108 is generated according to the principle described above. Because of this, the gravity and the buoyancy 109 in the opposite direction are generated. If this buoyancy 109 is in the direction opposite to the driving force 108 in the direction of the circulation flow path 102, the driving force is attenuated, so the power conversion efficiency of the magnetic fluid heat engine 100 becomes low.

  On the other hand, when it is in the same direction as the driving force, the apparent driving force is increased by the addition of the both, so that the power conversion efficiency of the magnetic fluid heat engine 100 can be enhanced. Therefore, it is preferable to configure the power conversion unit 107 so that the direction of the generated buoyancy 109 matches the direction of the driving force 108 as much as possible.

  The power conversion unit 107 shown in FIG. 2 is configured in view of the above. That is, in the posture at the time of use of the magnetic fluid heat engine 100, the heat receiving portion 102b is disposed above the gravity of the non-heat receiving portion 102c. By adopting such an arrangement, the direction of the component 109 a in the circulation flow direction of the buoyancy 109 is aligned with the direction of the driving force 108. Thus, the power conversion efficiency can be enhanced.

  If the definition of the embodiment of the present invention is described more precisely, the inner product of the driving force vector (direction of driving force) in the heat receiving portion of the magnetic fluid heat engine and the resultant force vector of gravity and inertia acting on the magnetic fluid. It is good to arrange a power conversion part so that at least negative and absolute value may become large.

Some application examples are shown in FIG. FIG. 3A is a schematic view of a magnetic fluid heat engine having a configuration in which the circulation flow path 102 is folded back in the power conversion unit 107 in order to miniaturize and simplify the magnetic field application means 103. Also in this heat engine, a driving force is generated such that the magnetic fluid flows from the non-heat receiving portion 102c toward the heat receiving portion 102b. Therefore, the driving force vectors _{F D} in the receiving portion 102b is as shown by the arrow 108. Therefore, in order to make gravity vector F _G (arrow 109) face in the opposite direction, the top 110 of the fold is placed downward in gravity.

Further, FIG. 3B shows an example of the magnetic fluid heat engine in the machine 120 which revolves around a specific circular track 121. Power is generated such that a driving force vector F _D (arrow 108) is generated in the opposite direction with respect to a composite vector F _{G + I} (arrow 112) of the gravity vector F _G (arrow 109) and the centrifugal force vector F _I (arrow 111). A converter is arranged.

  Subsequently, the detailed configuration of each part of the magnetic fluid heat engine 100 will be described. As the magnetic fluid 101, a general substance in which ferromagnetic fine particles such as magnetite or manganese zinc ferrite are dispersed in a mother liquor such as water or oil can be used.

  It is desirable that the tube or pipe member 102 corresponding to the circulation flow path be made of a nonmagnetic material such as resin, rubber, copper or aluminum so that a magnetic field acts on the inside. In order to enhance the efficiency of power conversion, it is important to transfer heat well to the magnetic fluid inside the heat receiving portion 102b, while it is important not to transfer heat to the magnetic fluid as much as possible in the non heat receiving portion 102c. is there. Therefore, the circulation channel 102 may be partially formed of a plurality of components by changing the material (for example, the heat receiving portion is made of copper having high thermal conductivity, the non-heat receiving portion is made of nylon having low thermal conductivity, etc.) .

  The magnetic field application unit 103 may use, for example, a neodymium magnet having a high magnetic flux density, and then combine a yoke of iron or the like so that the magnetic field in the circulation channel direction becomes strong. Or you may use the electromagnet which is easy to control the strength of a magnetic field, and on and off.

  The heat source 104 may be used by winding a linear heating element such as a heating wire or a sheet heating element having flexibility such as a rubber heater around the heat receiving portion 102 b of the tube or pipe member 102. Alternatively, when using electronic components to be dissipated in liquid cooling applications, for example, one end of a heat conducting member such as a metal sleeve or a graphite sheet is connected to surround a tube or pipe, and the other end is to be dissipated It may be connected to the electronic components of the above to transmit heat indirectly. The job means 105 is appropriately incorporated according to the purpose. In the case of liquid cooling applications, it may be omitted.

  The heat radiating means 106 is required to lower the temperature of the magnetic fluid 101 flowing from the heat receiving portion 102b by being heated by the heat source 104 to a high temperature and return it to the non-heat receiving portion 102c. If this is omitted, the temperature difference between the magnetic fluid in the heat receiving portion 102b and the non-heat receiving portion 102c gradually decreases, so that the power conversion efficiency decreases and the circulation eventually stops. As a heat radiation means, for example, a radiator may be incorporated in the middle of the circulation flow path 102 to radiate heat, or a radiation fin may be attached to a part of the circulation flow path 102 to radiate heat. Alternatively, the circulation flow path 102 itself may be exposed to the wind of a fan or another refrigerant to dissipate heat.

  Although the present invention is completed by the configuration described above, the present invention is not limited to this embodiment, and various modifications may be made within the scope of the present invention.

Subsequently, an embodiment of an apparatus using a magnetic fluid heat engine will be described.
Example 1
A lens-interchangeable digital camera (hereinafter simply referred to as a camera) according to a first embodiment of the present invention will be described below with reference to FIGS. 4 to 7. Here, in order to simplify the explanation, the influence of the inertial force is not considered here.

  FIG. 4 is a schematic view of a camera in the present embodiment. In FIG. 4, 100 denotes a magnetic fluid thermal engine, 200 denotes a camera body, 201 denotes a housing of the camera 200, 202 denotes a mount for separately connecting a lens (not shown), 203 denotes an imaging device, and 204 denotes an image An imaging optical axis orthogonal to the center of the imaging surface of the element is shown, and 205 denotes a main substrate having various ICs including the image processing IC 205a.

  Reference numeral 206 denotes a button and dial group for various operations, 207 denotes a finder, 208 denotes a strobe capacitor, 209 denotes a radiation fin, and 210 denotes a heat conduction member. In addition, in order to facilitate the following description, the direction of the camera 200 is defined as shown in the figure. The camera 200 has various other members, but is not an essential part of the present embodiment, so the illustration and the description thereof will be omitted.

  The shooting operation using the camera 200 will be briefly described. First, the user holds the camera with a suitable lens attached to the camera 200, and directs the camera 200 at a target to be photographed. Thereafter, the user determines the composition while looking into the finder 207, depresses the release button in the button group 206, and instructs the camera 200 to shoot. When receiving a photographing instruction, the camera 200 forms an image of a lens on the imaging element 203 and exposes it for a predetermined time. During exposure, photoelectric conversion is performed in the imaging element 203, and an electrical signal corresponding to the image to be photographed is accumulated. When the exposure is completed, each IC on the main substrate 205 mainly composed of the image processing IC 205a reads a signal of the imaging element 203 and creates image information.

  The obtained image information is appropriately processed and stored in a recording medium (not shown). Thus, an image file is obtained, and the photographing operation is completed. The above is mainly an operation at the time of shooting a still image, but also at the time of shooting a moving image, it is possible to obtain a moving image file by performing the same operation at high speed and continuously.

  In general, when moving images are taken for a long time with a digital camera, various electronic components such as the imaging device 203 and the image processing IC 205a consume a large amount of power by the above-described operation, and heat is generated. Will rise. At this time, in particular, the surface of the casing 201 in a portion close to the above-described electronic component is likely to be a locally high temperature portion called a so-called heat spot. Therefore, it is preferable to take measures against heat radiation to prevent the occurrence of heat spots and to promote heat radiation by well diffusing the heat generated in the housing, and the camera 200 of this embodiment is a magnetic fluid as heat radiation means therefor. A heat engine 100 is provided.

  That is, electronic components such as the imaging device 203 and the image processing IC 205a correspond to the heat source 104, and are indirectly connected to the heat receiving portion 102b of the magnetic fluid heat engine 100 via the heat conducting member 210a. The magnetic fluid is thereby circulated and heat is carried and diffused. The diffused heat is transmitted to the lens via the mount portion 202, for example, by the heat conducting member 210b. Further, it is transmitted to the strobe capacitor 208 via the heat conducting member 210c. In addition, when passing through the radiation fin 209 embedded in the bottom of the camera, it is released to the outside. As described above, heat is diffused to each part of the camera system, and the heat is released by being released to the outside of the camera.

  Here, in general, the camera has a horizontal position (a posture in which the upper surface side is vertically upward), a vertical position (a posture in which the grip side is vertically upward), and an elevation angle (front side) in order to devise a positional relationship with the object and composition. Photographing is performed in various postures such as a posture to be vertically upward), a depression angle (a posture to make the back surface side vertically upward), a tilt (rotation in the vertical direction) and a roll (rotation around the optical axis). Therefore, the arrangement of the power conversion unit for increasing the efficiency of the magnetic fluid heat engine is often not uniquely determined.

  Therefore, in such a case, for example, at least the driving force is not attenuated in any assumed photographing postures (so that the inner product of the combination of the driving force vector and each gravity vector is at least negative). It is good to arrange a power conversion part. Alternatively, with regard to each shooting posture, weighting may be performed according to parameters such as assumed use frequency and importance (such as required image quality), and the representative posture may be determined in consideration of these. The power conversion unit is disposed such that a driving force is generated in the opposite direction to a gravity vector (hereinafter referred to as a representative gravity vector) at that time. Next, the details of these methods will be described.

  In order to facilitate the following description, a three-dimensional coordinate system of orthogonal and sphere is introduced to the camera 200. FIG. 5 is a schematic view showing coordinate definition in the camera 200 in the present embodiment. In FIG. 5, the origin O of the coordinate system is set at the center on the imaging surface of the imaging device 203 (not shown), the x axis in the optical axis direction on the front side of the camera 200 The y-axis is set in the direction orthogonal to the optical axis on the side opposite to the grip side of the camera 200. Further, θ is set to the angle formed from the z-axis positive direction, and Φ is set to the angle formed from the x-axis positive direction to the y-axis positive direction in the xy plane.

According to the above setting, the gravity vector F _G (arrow 220. A unit vector is assumed to be a unit vector hereinafter) acting on the camera 200 in FIG. , -1), or (1, π, 0) in a spherical coordinate system.

First, the former method will be described. _F Gn gravity vector at a photographing position _{n (1, θ Gn, Φ} Gn) When the inner product is at least negative become such a driving force vector _F Dn with it _{(1, θ Dn, Φ Dn} ) in the range to be taken Is decided. Furthermore, since determines the amount corresponding similar range of numbers of photographing posture is assumed, superimposed them, by obtaining the common parts, it is possible to determine the final range should driving force vector F _D takes . Therefore, the power conversion part of the magnetic fluid heat engine may be disposed so that the driving force is generated in that direction.

  FIG. 6 is a schematic view showing the principle of the above method. 6 (a) to 6 (c) show the range of values to be taken by the gravity vectors 221 to 223 and the corresponding driving force vectors 225a to 225c in each photographing posture (a schematic diagram is added as a reference). It shows. The shaded area shown by 224a to 224c is the range for the driving force vector to be taken. Furthermore, these are superimposed, and what is shown in common is FIG. 6 (d). From this, it is preferable to arrange the power conversion unit 107 of the magnetic fluid heat engine 100 in the camera 200 so as to generate the driving force vector 225 within the range of the shaded area indicated by 224.

  By adopting the above-described method, the driving force of the magnetic fluid heat engine does not attenuate in any imaging posture, and thus the power conversion efficiency can be enhanced. On the other hand, depending on the type of imaging posture, there may be no solution in the above method, and there may not be a range in which the driving force vector can be taken. In such a case, the latter method should be taken.

  A schematic view of a method of determining a representative gravity vector by weighting is shown in FIG. FIG. 7A is a schematic view showing six types of shooting postures temporarily assumed by the camera 200, and weighting coefficients according to the assumed use frequency and importance are respectively assigned to the respective shooting postures. For example, since the erect posture shown in 231 is considered to have the highest frequency of use and importance, the weight coefficient is set to be the largest.

  In addition, since it is considered that the photographing posture with the grip side shown at 233 is higher in use frequency than the posture shown with the opposite side shown at 234 at the upper side, the weighting coefficient is set larger. Note that these coefficients are assumed to facilitate the explanation of the present embodiment, and are not based on the actual use results of the digital camera.

After assigning the weighting factor, as shown in FIG. 7B, the gravity vector is synthesized while taking it into consideration, and the representative gravity vector F _GC (arrow 237) in the representative posture is determined. From this, the opposite direction can be determined as the direction of the driving force vector F _D (arrow 238). Therefore, by arranging the power converter of the magnetic fluid thermal engine so as to generate the driving force in that direction, the power conversion efficiency can be enhanced according to many shooting scenes and importance, and a well-balanced configuration is provided. Can be provided.

  As described above, when the device on which the magnetic fluid heat engine is mounted has a plurality of use postures, it is possible to increase the efficiency in any posture, or by weighting according to the use frequency and importance After deciding on the representative attitude, it is recommended that the efficiency be maximized at that attitude.

Example 2
Hereinafter, a liquid crystal projector (hereinafter, simply referred to as a projector) provided with a magnetic fluid heat engine according to a second embodiment of the present invention will be described with reference to FIGS. 8 to 11.

  FIG. 8 is a schematic view of a projector in the present embodiment. In FIG. 8, reference numeral 300 denotes a projector main body provided with the magnetic fluid heat engine 100, 301 denotes a casing of the projector 300, and 301a and 301b denote ventilation openings provided with filters. Reference numeral 302 denotes an illumination optical system including a light source 302a, 303 denotes a reflection mirror, 304 denotes a color separation / combination optical system including a reflection type liquid crystal panel (so-called LCOS) (not shown), dichroic mirrors and prisms, etc. Each shows an optical system.

  Reference numeral 306 denotes a power supply system, 307 denotes a control system, and 308 denotes a leg member. Furthermore, the magnetic fluid heat engine is provided with a radiator 106a and a fan 106b as heat dissipating means. In addition, the projector 300 has various members, but is not an essential part of the present embodiment, so illustration and description thereof will be omitted.

  The projection operation by the projector 300 will be briefly described. When an image signal to be projected is input from an input interface (not shown), a corresponding display state is formed on the LCOS in the color separation / combination optical system 304 through the control system 307. The light source 302 a converts the electricity supplied from the power supply system 306 into light, and supplies the light to the color separation / combination optical system 304 via the mirror 303. The color separation / combination optical system 304 separates the supplied light into each of the three primary colors R, G, B, reflects each on LCOS to obtain an image, combines them, and forms an image to be projected. It leads to the projection optical system 305. Finally, after adjustment for obtaining a desired projection state such as zoom, focus, tilt, or shift is performed by the projection optical system 305, an image is projected on a screen or the like.

  During the above-described operation, the projector 300 consumes a large amount of power, particularly at the light source 302a, and generates heat. Therefore, the projector 300 is provided with the magnetic fluid heat engine 100 as a heat dissipation means in order to suppress the failure of the light source 302a and the surrounding members due to the heat and the reduction of the life. That is, the light source 302a corresponds to the heat source 104, and is connected directly or indirectly to the heat receiving portion of the magnetic fluid heat engine 100 by a heat conduction member (not shown). As a result, the magnetic fluid circulates in the flow path and carries away the heat of the light source 302a. The carried heat is released from the radiator 106 a to the outside of the projector 300, so heat is dissipated.

  Similar to the camera 200 in the first embodiment, the projector 300 is not limited to one type of attitude during operation, and is used in a plurality of attitudes. A typical installation method of the projector 300 is shown in FIG. FIG. 9A shows a so-called stationary installation method, in which the bottom surface having the leg members 308 is placed on the reference surface 321 a with gravity directed downward. Moreover, FIG.9 (b) is the installation method by what is called ceiling suspension, and the bottom face is fixed to the ceiling 321b, facing gravity upwards. The former is frequently used in office meeting spaces and small meeting rooms, and the latter in large meeting rooms and halls.

  Here, assuming that the posture of the projector 300 at the time of stationary shown in FIG. 9A is in the upright state, the posture at the time of ceiling suspension shown in FIG. 9B is inverted and both receive gravity in opposite directions. It will be. Thus, in the embodiment described above, it is not possible to improve the power conversion efficiency of the magnetic fluid heat engine at both postures. Also, even if weighting is performed, the result is only to ignore one of the postures, which is not sufficient. Therefore, a configuration of a power conversion unit for a device having such use postures in opposite directions is required.

  In such a case, it is preferable that the configuration of the power conversion unit of the magnetic fluid heat engine be variable according to the change in attitude of the device so that the direction of the generated driving force can be changed. As a result, the power conversion efficiency of the magnetic fluid heat engine can be enhanced in any posture. Subsequently, a configuration for realizing it will be described.

  FIG. 10 is a schematic view showing a first example of the configuration of the power conversion unit 107 of the magnetic fluid heat engine 100 in the projector 300. As shown in FIG. 10A shows the upright state of the projector 300, and FIG. 10B shows the inverted state of the projector 300. As shown in FIG. In FIG. 10, 102a indicates a magnetic field application unit, 102b indicates a heat receiving unit, 102c indicates a magnet unit corresponding to a non-heat receiving unit, 103 indicates a magnetic unit, and 104 indicates a heat source, and the other end is a light source of the projector 300. The heat conduction member connected with 302a is each shown.

Furthermore, 331 indicates a slide rail, 332 indicates a ballast, and 333 indicates a cushion member. Also, 334a and 334b (F _G1 and F _G2 ) drive forces acting on the magnetic fluid in the heat receiving portion 102 b, and 335 a and 335 b (F _D1 and F _D2 ) drive forces acting on the magnetic fluid in the heat receiving portion 102 b. Show each vector.

  The heat receiving portion 102b and the two non-heat receiving portions 102c all have the same shape. Furthermore, the magnet unit 103 is connected to the slide rail 331 via the ballast 332 so as to be movable relative to it. From this, even when the projector 300 is in the upright or inverted posture, the magnet unit 103 moves downward by gravity under the influence of gravity, and the heat receiving portion 102b seen from the magnet unit is effective (a position in the magnetic field applying portion 102a) Side) is positioned above the non-heat receiving portion 102c.

  Therefore, the driving force is generated above the gravity and directed in the direction opposite to the gravity, so that the power conversion efficiency of the magnetic fluid heat engine can be enhanced in both the erect and inverted postures. At this time, the circulation directions of the magnetic fluid in the magnetic fluid heat engine 100 are opposite to each other, but can be used without any problem as a heat radiation application in the present embodiment.

  In the present embodiment, the ballast 332 is added in order to prevent the magnet unit 103 from being raised by the reaction force at the time of operation of the magnetic fluid heat engine 100. If the magnet unit 103 is sufficiently heavy with respect to the reaction force, it may be omitted. Further, a cushion member 333 is added to cushion an impact at the time of movement of the magnet unit 103. Alternatively, a damper mechanism or the like may be used.

  Further, instead of moving the magnet unit 103 by gravity as described above, the control unit such as a motor or a user may move the magnet unit manually. In this case, for example, the projector 300 may be configured to include a posture detection unit, drive the motor according to the output, or prompt the user to move the magnet unit 103. Alternatively, the magnet unit 103 may be set to move in conjunction with a screen reverse operation or the like, which is required when changing the attitude of the projector.

  Next, FIG. 11 is a schematic view showing a second example of the configuration of the power conversion unit 107 of the magnetic fluid heat engine 100 in the projector 300. As shown in FIG. FIG. 11 shows the upright state of the projector 300. A switching mechanism in the heat conducting member 341, in which the heat receiving portion 102d and 102e can be either a heat receiving portion or a non-heat receiving portion, 341 corresponds to a heat conduction member by a plate spring, and 342 corresponds to a heat conduction direction switching means. The reference numerals 342a and 342b indicate thermal contact points of the heat conduction direction switching mechanism 342, 343 indicates an inner wall for fixing the magnet unit 103, 344 indicates a linear motion motor, and 345 indicates a posture detection means of the projector 300.

  In this configuration, the heat conducting member 104 is connected to both of the heat receiving parts 102d and 102e, and both are connected to the light source 302a via the switching mechanism 342 of the heat conduction direction. From this, by using the switching mechanism 342 to transmit the heat of the light source 302a to one area and not to transmit the heat to the other area, the direction in which the magnetic fluid flows can be freely switched. It becomes possible.

  That is, in FIG. 11, since the heat contact 342a is on and 342b is off, the heat receiving portion 102d is a heat receiving portion and the heat receiving portion 102e is a non heat receiving portion, so that driving force is generated above gravity. Thus, the power conversion efficiency can be enhanced. On the other hand, when the projector 300 is inverted, the efficiency can be similarly enhanced by turning off the heat contact 342 a and turning on the heat contact 342 b.

  In the heat conduction direction switching mechanism 342, turning on and off of the heat contact is realized by elastic contact and non-contact between the plate springs. That is, when the thermal contact is turned on, a force is applied by the linear motion motor 344 so as to deform the plate springs in a direction in which they are in close contact with each other. This minimizes the increase in thermal resistance in this area.

  The heat conduction direction switching means may have another configuration. A configuration example of the switching means is shown in FIG. For example, as shown in FIG. 12A, the thermal contacts 342a and 342b have a gap, and the thermal conduction may be turned on by inserting the thermal conductive member 342c into either one of them.

  In the case of this configuration, there is an advantage that it is easy to keep the increase in the thermal resistance low, since it is easy to obtain a wider and more rigid contact portion. In addition, as shown in FIG. 12 (b), in the configuration in which the heat transfer liquid 342d is enclosed in the heat insulating container 342e, the heat transfer liquid is filled between any one of the heat contact points so that the heat conduction is turned on. You may In the case of this configuration, since the heat transfer liquid automatically moves in accordance with gravity, there is an advantage that the attitude control means is not required.

  The configurations of the two types of power conversion units 107 described above are common in that both can make the direction of generation of the driving force reverse. However, they have different characteristics and may be selected appropriately. For example, in the former method of moving the magnet unit 103, there is no hot contact between the light source 302a and the heat receiving portion 102b, so that the thermal resistance can be reduced and the efficiency can be easily improved. On the other hand, in the latter method using the heat conduction direction switching mechanism 342, although the thermal resistance is likely to increase due to the presence of the thermal contact, it is not necessary to move the magnet unit 103. It has the advantage of being easy to miniaturize in the direction.

  As described above, according to the present embodiment, even in an apparatus having a plurality of use postures receiving gravity in opposite directions, any posture can be achieved by making the configuration of the power conversion unit of the magnetic fluid heat engine variable. Can also provide a configuration for enhancing the power conversion efficiency.

100. Magnetic fluid heat engine 101. Magnetic fluid 102. Circulation channel 102a. Magnetic field application unit 102b. Heat receiving unit 102c. Non-heat receiving part 103. Magnetic field application means 104. Heat source 107. Power converter 108. Driving force vector 109. Buoyancy vector

Claims (9)

Magnetic fluid,
A circulation channel of the magnetic fluid;
A magnetic field application unit disposed in part of the circulation channel;
A heat receiving unit and a non-heat receiving unit disposed in the magnetic field application unit;
A heat source connected to the heat receiving unit;
A magnetic field application unit that applies a magnetic field to the magnetic field application unit;
With respect to the resultant force vector of gravity and inertial force acting on the magnetic fluid in the heat receiving portion,
A magnetic fluid heat engine, wherein the heat receiving portion, the non-heat receiving portion, and the magnetic field application means are arranged so as to generate a driving force in such a direction that the value of the inner product of the vector becomes negative. The magnetic fluid heat engine according to claim 1, wherein the heat receiving portion is disposed above the gravity of the non-heat receiving portion. It is placed on a predetermined orbit
The magnetic fluid heat engine according to claim 1 or 2, wherein the heat receiving portion is disposed closer to the center of revolution than the non-heat receiving portion. In the previous magnetic field application unit, the circulation channel has a folded shape,
The heat receiving part is disposed on one side and the non-heat receiving part is disposed on the other side of the reciprocating flow path generated by the folded shape,
The magnetic fluid heat engine according to claim 1, characterized in that the top of the folded shape is arranged to be directed downward by gravity. Have multiple usage postures,
With respect to the resultant force vector of gravity and inertia in all cases of the plurality of use postures,
The magnetic fluid according to any one of claims 1 to 4, wherein the heat receiving portion and the non-heat receiving portion are arranged so as to generate a driving force in a direction such that the value of the inner product of the vector becomes negative. Heat engine. Multiple usage postures,
Having a weighting factor corresponding to each of the plurality of use postures;
With respect to the representative resultant force vector of the gravity and the inertial force of the plurality of use postures, which are synthesized in consideration of the weighting factor,
The magnetic fluid according to any one of claims 1 to 4, wherein the heat receiving portion and the non-heat receiving portion are arranged so as to generate a driving force in a direction such that the value of the inner product of the vector becomes negative. Heat engine. Have multiple usage postures,
A magnetic field application unit is movably held in the flow channel direction of the magnetic field application unit of the circulation flow channel,
The magnetic fluid heat engine according to any one of claims 1 to 4, wherein the magnetic field application means is moved such that the heat receiving part is located above the gravity of the non-heat receiving part in each of the use postures. Magnetic fluid,
A circulation channel of the magnetic fluid;
A magnetic field application unit disposed in part of the circulation channel;
A plurality of heat receiving portions disposed in the magnetic field applying portion;
A heat source,
Heat conduction direction switching means for switchably connecting the heat source to the plurality of heat receivable portions;
A magnetic field application unit that applies a magnetic field to the magnetic field application unit;
A magnetic fluid heat engine characterized in that the direction of heat conduction is switched so as to conduct the heat of the heat source to the heat-receiving part on the side located above the gravity when in each of the use postures. An apparatus equipped with the magnetic fluid heat engine according to any one of claims 1 to 8.