JP2020012601A - Manufacturing method for stack for thermoacoustic device, manufacturing apparatus for stack for thermoacoustic device and thermoacoustic device - Google Patents

Abstract

To provide a manufacturing method for a stack for a thermoacoustic device that can improve energy exchange efficiency and also suppress an increase in manufacturing cost, a manufacturing apparatus for the stack for the thermoacoustic device, and the thermoacoustic device.SOLUTION: A manufacturing method includes: a welding process of forming a structure A having adjacent thin pipes 21 welded together by heating a plurality of thin pipes 21 and a storage pipe 22 after bundling the plurality of thin pipes 21 with axes aligned and housing the plurality of bundled thin pipes 21 in a storage pipe 22 whose inner shape is substantially the same with an outer diameter (outer shape) of the plurality of thin pipes 21; a pressurizing process of pressurizing respective inner spaces of the thin pipes 21 of the structure A under atmospheric pressure higher than outside pressure; and a drawing process of heating one axial end of the structure A and axially drawing the one axial end of the structure A.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a method for manufacturing a stack for a thermoacoustic device that exchanges energy based on a thermoacoustic effect, an apparatus for manufacturing a stack for a thermoacoustic device, and a thermoacoustic device.

  As a conventional stack for a thermoacoustic device, there is known a stack in which a plurality of through holes are formed along a flow direction of a working fluid flowing inside a predetermined pipe (see Patent Document 1). This type of stack for thermoacoustic devices is manufactured using a structure in which a plurality of thin tubes made of a predetermined material are densely arranged, and the plurality of thin tubes constitute a plurality of through holes.

JP 2012-229892 A

  One of the manufacturing methods of the thermoacoustic device stack of Patent Document 1 (hereinafter, also referred to as a conventional first manufacturing method) includes the following. That is, a plurality of thin tubes are densely arranged to form a first structure, the first structure is heated and cooled, and adjacent thin tubes are welded to each other to form a second structure, and The second structure is manufactured by heating one end in the axial direction, pulling one end in the axial direction, and then cooling.

  Further, the following is mentioned as another manufacturing method (hereinafter, also referred to as a second conventional manufacturing method) of the thermoacoustic device stack of Patent Document 1. That is, a plurality of thin tubes are densely stored in a storage container having an internal space corresponding to the internal shape of the tube, and in this stored state, a predetermined material that has been melted is poured into the internal space and solidified. It is manufactured by fixing it to a container.

  Note that ωτ is known as one of the indexes for evaluating the energy exchange efficiency of the thermoacoustic device stack. τ means the relaxation time, which is determined by the physical property value of the working fluid and the radius of the through hole. Ω means a self-excited vibration angular frequency (resonance angular frequency) and is determined by the sound velocity of the working fluid and the length of the flow path (tube). Specifically, when the vibration angular frequency ω is high and ωτ≫1, almost no energy exchange is performed, and an adiabatic process is performed. Therefore, adiabatic vibration waves (for example, sound waves) propagate in the through holes. On the other hand, when the vibration angular frequency ω is low and ωτ≪1, energy exchange is sufficiently performed, and an isothermal process is performed.

  However, in the first conventional manufacturing method described above, the outer diameter of the through hole is defined by the drawing ratio of the thin tube. That is, the cross-sectional shape of the through hole of the stack obtained as a result of manufacturing is a shape similar to the thin tube before being pulled.For example, when the thin tube has a circular cross section, the through hole has a proportionally reduced circular shape. .

  In the case of using thin tubes having a circular cross section as described above, when a plurality of thin tubes are arranged in the closest density, the center of each thin tube is arranged at a position that is a vertex of a regular hexagon. At this time, the internal space cannot be completely filled with the narrow tube alone, and a gap space having a substantially triangular cross section in which each side becomes an arc is formed between adjacent narrow tubes.

  Therefore, when manufacturing a thermoacoustic device stack using a thin tube having a circular cross section, the gap space having a substantially triangular cross section also functions as a flow path. In addition, since this gap space has a size and shape different from those of the through-hole, a sound field (vibration field) that is acoustically different is obtained. As a result, the local ωτ may be non-uniform, and the energy exchange efficiency may be reduced.

  Here, when a narrow tube with a regular hexagonal cross section is used instead of a circular sectional shape, it is possible to lay out and arrange densely so that no interstitial space is generated between adjacent narrow tubes. A glass thin tube or the like has a complicated shape compared to a circular cross-section, and the amount of circulation is limited. Therefore, the cost of manufacturing or purchasing the thin tube is required, which may lead to an increase in the manufacturing cost.

  In the second conventional manufacturing method, it is necessary to use molds for casting the material to be poured in advance. Further, this material is limited to a material having a lower melting point than the material of the thin tube, and there is a possibility that the degree of freedom in design may be reduced. In addition, since the upper limit of the operating temperature of the stack for a thermoacoustic device manufactured by this manufacturing method is determined by the material having the lowest melting point or the lowest heat-resistant temperature, there is a possibility that the stack application and operating environment may be limited. .

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a method for manufacturing a thermoacoustic device stack that can improve energy exchange efficiency and suppress an increase in manufacturing cost. And a thermoacoustic apparatus.

In order to achieve the above-mentioned object, a method for manufacturing a thermoacoustic device stack, a thermoacoustic device stack manufacturing apparatus, and a thermoacoustic device according to the present invention are characterized by the following (1) to (4).
(1)
A plurality of thin tubes are bundled in the same axial direction, and the bundled thin tubes are housed in a storage tube having an inner shape substantially equal to the outer shape of the plurality of thin tubes. A welding step of heating to form a structure in which the adjacent thin tubes are welded to each other;
A pressurizing step of pressurizing each of the internal spaces of the thin tube of the structure at a pressure higher than an external pressure;
A tensioning step of heating one axial end of the structure, and pulling the one axial end of the structure along the axial direction,
A method for manufacturing a stack for a thermoacoustic device, comprising:
(2)
The manufacturing of the thermoacoustic device stack according to (1), wherein the one end in the axial direction of the structure is pulled by sandwiching and pulling the one end in the axial direction of the storage tube of the structure. Method.
(3)
A plurality of thin tubes are bundled together in the axial direction, and the adjacent thin tubes are welded to each other in a state where the inner shape is housed in a housing tube having an inner shape substantially equal to the outer shape of the bundled thin tubes. For the structure, a pressurizing unit that pressurizes each of the internal spaces of the thin tubes of the structure with a pressure higher than the outside pressure.
A tension portion that grips the one axial end of the structure whose one axial end is heated, and pulls the one axial end along the axial direction,
An apparatus for manufacturing a stack for a thermoacoustic device, comprising:
(4)
A plurality of thin tubes bundled in the same axial direction are housed inside a housing tube having an inner diameter substantially equal to the outer shape of the plurality of thin tubes, and a structure in which adjacent thin tubes are welded to each other is formed inside the thin tube. A thermoacoustic apparatus comprising: a stack formed by pulling one end in the axial direction of the structure along the axial direction in a state where each space is pressurized at a pressure higher than the external pressure.

According to the configuration of the method for manufacturing a stack for a thermoacoustic device of the above (1), the energy exchange efficiency can be improved and the increase in the manufacturing cost can be suppressed. Further, by pulling the structure in a pressurized state, the cross-sectional shape and dimensions of the through-hole (flow path) of the stack are made uniform and the diameter of the through-hole is prevented from becoming excessively small. The thickness between them becomes thin, and the through holes can be provided as densely as possible. As a result, the ratio of the through hole to the cross section of the stack increases, and the aperture ratio of the stack is increased and ωτ is reduced. Therefore, a thermoacoustic device having good energy conversion efficiency can be manufactured.
According to the configuration of the method for manufacturing a stack for a thermoacoustic device of the above (2), the plurality of thin tubes housed in the housing tube can be uniformly pressed radially inward, so that the tube is pulled. The cross-sectional shape of the later thin tube can be formed more uniformly and accurately.
According to the configuration of the thermoacoustic device stack manufacturing apparatus of the above (3), a thermoacoustic device stack that can improve energy exchange efficiency and suppress an increase in manufacturing cost can be manufactured.
According to the thermoacoustic device of the above (4), the energy exchange efficiency can be improved, and the increase in the manufacturing cost can be suppressed.

  ADVANTAGE OF THE INVENTION According to the manufacturing method of the stack for thermoacoustic apparatuses, the manufacturing apparatus of the stack for thermoacoustic apparatuses, and the thermoacoustic apparatus of the present invention, the gap space between adjacent thin tubes when a plurality of thin tubes are bundled with their axial directions aligned. Are filled in the manufacturing process, and the cross-sectional shape and distribution of each through-hole (flow path) of the stack are formed substantially uniformly. By pulling while applying pressure, the cross-sectional shape and dimensions of the through holes of the stack are made uniform and the diameter of the through holes is prevented from becoming excessively small. It can be provided as dense as possible. As a result, the ratio of the through hole to the cross section of the stack increases, and the aperture ratio of the stack can be improved. In addition, the grid of the cross section of the stack becomes finer, and the grid smoothly continues in the longitudinal direction. As a result, pressure loss can be reduced while reducing ωτ. Also, as compared with the case where the stack is similarly reduced from the structure and manufactured, since the structure is provided by being pulled in the longitudinal direction, more stacks can be cut out and the manufacturing cost is reduced. can do. Further, even if an inexpensive thin tube having a circular cross section is used, a flow path originating from the above-mentioned gap space is not provided, so that an inexpensive and energy-efficient stack can be manufactured. As described above, the energy exchange efficiency can be improved, and an increase in manufacturing cost can be suppressed.

  The present invention has been briefly described above. Further, details of the present invention will be further clarified by reading through the modes for carrying out the invention described below (hereinafter, referred to as “embodiments”) with reference to the accompanying drawings.

FIG. 1 is a cross-sectional view schematically illustrating a configuration of a thermoacoustic engine according to an embodiment of the present invention. FIG. 2 is a three-dimensional perspective view illustrating the structure of the thermoacoustic device stack according to the embodiment of the present invention. FIG. 3 is a three-dimensional perspective view illustrating a thin tube constituting a part of the thermoacoustic device stack shown in FIG. 2. FIG. 4 is a schematic diagram illustrating a method for manufacturing the thermoacoustic device stack illustrated in FIG. 2 and a manufacturing apparatus thereof. FIGS. 4A to 4D each illustrate one step of the manufacturing method. FIG. FIG. 5 is a schematic diagram schematically illustrating the configuration of the pressing unit illustrated in FIG. 4C, and FIG. 5A is a cross-sectional view taken along a plane passing through the axial direction. FIG. 5B is a sectional view taken along line VB-VB of FIG. FIG. 6 is an exploded perspective view schematically illustrating a configuration in a tension step illustrated in FIG. 4D and a subsequent cutting step. FIG. 7 is a partially enlarged view illustrating a side surface of the structure viewed from the Y and Z directions shown in FIG. FIG. 8 is a schematic diagram illustrating a modification of the pressurizing section of the thermoacoustic device stack manufacturing apparatus according to the embodiment of the present invention. 9A is a cross-sectional view taken along the line IVA-IVA in FIG. 8, FIG. 9B is a cross-sectional view taken along the line IVB-IVB in FIG. 8, and FIG. 9C is a cross-sectional view taken along the line IVC-IVC in FIG. .

Specific embodiments of the method for manufacturing a thermoacoustic device stack, the thermoacoustic device stack manufacturing device, and the thermoacoustic device of the present invention will be described below with reference to the drawings.
Note that the term “stack” generally refers to a stack of a plurality of members, but in this specification, an energy conversion member for a thermoacoustic device formed from one member is also referred to as a “stack”. .

<Structure of thermoacoustic engine and thermoacoustic device stack>
A configuration of a thermoacoustic engine (thermoacoustic device) 1 and a thermoacoustic device stack (hereinafter, also simply referred to as a stack) 10 according to the present embodiment will be described with reference to FIG. FIG. 1 is a cross-sectional view schematically illustrating a configuration of a thermoacoustic engine 1 according to the present embodiment. FIG. 2 is a three-dimensional perspective view illustrating the structure of the thermoacoustic device stack 10 according to the present embodiment.

  As shown in FIG. 1, a thermoacoustic engine 1 including a thermoacoustic device stack 10 of the present embodiment includes a tube 2, a stack 10, a high-temperature side heat exchanger 3, and a low-temperature side heat exchanger 4. The tube 2 is a cylindrical tube in which the working fluid F is sealed. The stack 10 is a member arranged inside the tube 2. The high-temperature side heat exchanger 3 and the low-temperature side heat exchanger 4 are devices that are arranged so as to sandwich the stack 10 inside the tube 2 from both axial directions of the tube 2 and give the stack 10 a temperature gradient.

  Outside the pipe 2, a high-temperature heat source 5 is provided on the high-temperature side heat exchanger 3 side, and a low-temperature heat source 6 is provided on the low-temperature side heat exchanger 4 side. The stack 10 converts heat energy and vibration energy that propagate through the working fluid F. Due to this conversion, the thermoacoustic engine 1 exchanges energy between the working fluid F sealed in the tube 2 and heat energy flowing from the high-temperature side heat exchanger 3 to the low-temperature side heat exchanger 4. It is possible to do.

  As shown in FIG. 2, the stack 10 is formed in a cylindrical shape corresponding to the internal shape of the tube 2. The stack 10 is formed at the center of the main body 11 along the flow direction of the working fluid F flowing inside the pipe 2 and the main body 11 disposed inside the pipe 2 and used as a flow path of the working fluid F. And a plurality of through holes 11A. Further, a central portion of the main body 11 of the stack 10 is formed by a plurality of thin tubes 21 as described later. The outer peripheral portion of the main body 11 of the stack 10 is formed by a storage tube 22 that stores a plurality of thin tubes 21 therein.

In the present embodiment, the plurality of through-holes 11 </ b> A of the stack 10 are arranged (densely) at the center of the main body 11. The plurality of through holes 11A (an aggregate of the through holes 11A) are provided so as to be substantially circular as a whole when the stack 10 is viewed from the axial direction, and the center thereof substantially coincides with the axis of the stack 10. Each of the through holes 11A of the stack 10 is formed to have a substantially regular hexagonal cross section. The hole diameter of the through hole 11A is defined by the length (resonance angular frequency ω) of the tube 2 and the thermal relaxation time τ (= r ² / α, where r is the hole diameter and α is the physical property value of the working fluid). The value of ωτ is set in the range of 1 to 10. The intervals (pitch) between the through holes 11A are provided as dense as possible in order to increase the aperture ratio (porosity) of the stack 10. The higher the aperture ratio of the stack 10, the smaller the pressure loss and the smaller the energy loss.
The plurality of through holes 11 </ b> A of the stack 10 are arranged inside the tube 2 in a state where the axial direction thereof substantially matches the axial direction of the tube 2.

<Regarding stack manufacturing method and stack manufacturing apparatus>
Next, a method of manufacturing the stack 10 and the manufacturing apparatus 30 will be described with reference to FIGS. FIG. 3 is a three-dimensional perspective view illustrating a thin tube 21 constituting a part of the thermoacoustic device stack 10. FIGS. 4A to 4D are schematic views illustrating a method for manufacturing the thermoacoustic device stack 10 and the manufacturing apparatus 30. FIGS. 4A to 4D each illustrate one process of the manufacturing method. It is. FIG. 5 is a schematic diagram schematically illustrating the configuration of the pressing unit 31 shown in FIG. 4C, and FIG. 5A is a cross-sectional view taken along a plane passing through the axial direction. FIG. 5B is a sectional view taken along line VB-VB of FIG. FIG. 6 is an exploded perspective view schematically illustrating a configuration in a tension step illustrated in FIG. 4D and a subsequent cutting step. FIG. 7 is a partially enlarged view illustrating a side surface of the structure viewed from the Y and Z directions shown in FIG.

As shown in FIG. 3, in the present embodiment, a thin tube 21 having a substantially circular cross section and a storage tube 22 (see FIGS. 4B, 5, and 6) of a thick tube having a diameter larger than the thin tube 21 are provided. The stack 10 is manufactured using the above. The thin tube 21 and the storage tube 22 are made of glass (quartz if high heat resistance is required) material, are formed in a cylindrical shape, and have through holes 21A and 22A, respectively. The inner diameter of the storage tube 22 is set to be substantially equal to the outer diameter (outer diameter) of the bundled thin tubes 21 in a manufacturing process to be described later, in which a plurality of thin tubes 21 are bundled with their axial directions aligned.
As described above, the through-hole 21A of the thin tube 21 forms the through-hole 11A of the stack 10, and the storage tube 22 forms the outer peripheral portion of the main body 11 of the stack 10.

As shown in FIG. 4 (A), a plurality of thin tubes 21 are prepared, the plurality of thin tubes 21 are aligned in the axial direction, and bound by a restraining means such as a thread or a tape. Thereafter, as shown in FIG. 4B, the bundled plural thin tubes 21 are stored in the storage tube 22 so as to be inscribed in the inner peripheral surface of the storage tube 22. In this storage, as many small tubes 21 as possible are stored in the storage tube 22. Thereby, the thin tube 21 is stored in the storage tube 22 in a state of being pressed against the adjacent thin tube 21. Then, the plurality of thin tubes 21 and the storage tube 22 are heated to near the softening point by a heater or the like, maintained for a predetermined time, and then cooled. At this time, since the thin tube 21 is in pressure contact with the adjacent thin tube 21, the thin tube 21 is welded to the adjacent thin tube 21 by being cooled after being heated. Thus, the structure A in which the adjacent thin tubes 21 are welded to each other is formed (ie, a welding step).
In the welding step, as shown in FIG. 7A, the plurality of thin tubes 21 are densely arranged inside the storage tube 22. However, the internal space cannot be completely filled with the narrow tube 21 alone without any gap, and a substantially triangular gap space S1 in which each side has an arc shape is formed between the adjacent narrow tubes 21.

Here, the configuration of the manufacturing apparatus 30 of the stack 10 of the present embodiment will be described.
4A and 4B, such as a restraining means (not shown) for bundling a plurality of thin tubes 21 and a heater for heating the thin tubes 21 and the storage tube 22. Various heating means (not shown) and the like can be employed. Here, in particular, a portion for realizing the manufacturing method of FIGS. 4C and 4D will be specifically described.

  As shown in FIGS. 4C, 4D, 5 and 6, the manufacturing apparatus 30 of the stack 10 according to the present embodiment is different from the above-described structure A in the inside of the thin tube 21 of the structure A. A pressurizing portion 31 for pressurizing each space at a pressure higher than the outside pressure; and a tension portion 38 for gripping one axial end of the structure A in the radial direction and pulling one axial end along the axial direction. And a cutting machine 41 (see FIG. 6) that cuts the structure A pulled in a radial direction after a tensioning step described later.

  The pressing portion 31 is formed in an annular shape, and includes first and second lids 32 and 36 having flange portions 33 and 37 provided on the peripheral edge thereof. The first and second lids 32 and 36 cover both ends in the axial direction of the structure A to make the structure A airtight (see FIG. 5A).

  As shown in FIG. 5A, the inner diameter of the flange portion 33 of the first lid 32 is such that the first lid 32 can be fitted to the structure A outside. The annular portion of the first lid 32 is provided with a flow path 34 through which gas can pass. The other end of the flow path 34 is connected to a compression device (not shown) such as a compressor.

As shown in FIGS. 5A and 5B, a disk-shaped mesh portion 35 is provided on the inner peripheral surface of the flange portion 33 of the first lid 32. The mesh portion 35 is connected to the axially intermediate portion of the inner peripheral surface of the flange portion 33 at the peripheral edge of the mesh portion 35, and has a predetermined gap space S2 between itself and the inner end surface of the first lid 32.
Note that the gap space S2 is pressurized at a pressure higher than the outside pressure via the flow path 34 in a pressurizing step described later.

  In addition, the mesh portion 35 is in contact with one axial end surface of the structure A at the outer end surface of the mesh portion 35. A plurality of through-holes 35A are formed in the mesh portion 35 at positions corresponding to the through-holes 21A of the thin tubes 21 of the structure A when the first lid 32 is fitted onto the structure A. Thereby, when the first lid 32 closes one axial end of the structure A, the mesh portion 35 closes the through hole 21A of the thin tube 21 while closing the gap space S1 formed in the structure A. It communicates with the gap space S2.

  As shown in FIG. 4C, the first and second lids 32 and 36 of the pressurizing unit 31 are used to axially move the structure A using the manufacturing apparatus 30 for the stack 10 configured as described above. Both ends are closed to make the structure A airtight. Then, a compression device such as a compressor is operated to pressurize the gap space S2 on the first lid 32 side at a pressure higher than the outside pressure through the flow path 34 (ie, a pressurizing step). At this time, the gap space S2 communicates with the internal space of the through hole 21A of the thin tube 21 via the through hole 35A of the mesh portion 35 (see FIG. 5A). Therefore, the internal space of the through-hole 21A is also uniformly pressurized with the pressurization of the gap space S2. On the other hand, at the time of this pressurizing step, one end in the axial direction of the substantially triangular gap space S1 (see FIG. 7 (A)) between the narrow tubes 21 where each side becomes an arc is other than the through hole 35A of the mesh portion 35. And the other end in the axial direction is closed by the second lid 36, so that no pressure is applied.

  As shown in FIG. 4D, the pulling portion 38 is configured by a pair of arms 39. At the tip of the arm 39, a substantially C-shaped grip portion 40 is provided. The pair of arms 39 makes the inner peripheral surface of the holding portion 40 contact the outer peripheral surface of the storage tube 22 of the structure A, and clamps the structure A in the radial direction. At this time, the pair of arms 39 has a predetermined elastic force in a direction approaching each other and holds the structure A. Thereby, even if the diameter of the structure A changes in the holding portion, the structure can be held correspondingly. In this sandwiched state, the pulling portion 38 pulls one axial end of the structure A along the axial direction.

  Then, as shown in FIGS. 4D and 6, in a state where the structure A shown in FIG. 4C is pressurized, one end in the axial direction of the structure A is heated to a temperature higher than the softening point by a heater or the like. Then, one end in the axial direction of the storage tube 22 of the structure A is sandwiched between the pair of arms 39 of the pulling portion 38 and pulled along the axial direction so as to be separated from the other end in the axial direction. Thereby, the structure A in which the thin tube 21 and the storage tube 22 are extended in the axial direction is formed (that is, the tension step).

  In the tensioning step, the storage tube 22 presses the plurality of thin tubes 21 radially inward by pulling the storage tube 22 shown in FIGS. 4D and 6. At this time, the thin tubes 21 are also heated and softened, and the inner spaces of the respective thin tubes 21 are in a pressurized state. Drag toward the direction acts. On the other hand, a substantially triangular gap space S1 (see FIG. 7A) in which each side becomes an arc between each of the thin tubes 21 is not pressurized and is substantially the same as the outside air pressure. Therefore, the cross-sectional shape of the thin tube 21 changes due to the pressing by the storage tube 22 and the drag of the internal space of each thin tube 21, and the gas in the gap space S1 is pushed out. Thereby, the gap space S1 is filled. Then, as shown in FIG. 7 (B), the pressing by the storage tube 22 and the drag of the internal space of each thin tube 21 are balanced, and finally the cross-sectional shape of the thin tube 21 is formed into a substantially regular hexagon. .

  Further, the hole diameter of the thin tube 21 stretched in the stretching step is reduced according to the balance between the pressure for pressurizing the internal space of the thin tube 21 and the distance for pulling the structure A. Therefore, it is preferable to set the pressure for pressurizing the internal space of the thin tube 21 and the distance for pulling one end of the structure A in accordance with the desired hole diameter of the through hole 21A. Similarly, the heating temperature and the pulling speed also affect the reduction rate of the thickness of a material such as glass in the cross-sectional shape of the thin tube 21, and thus may be appropriately adjusted as a setting parameter.

  After the tension step, as shown in FIG. 6, the structure A is cut into a predetermined length by a cutting machine 41 such as a dicing saw, and the cut surface is polished. As a result, as shown in FIG. 7B, a plurality of through-holes 11A having a substantially regular hexagonal cross section are densely arranged, and a stack 10 having a honeycomb shape is formed.

(Modification)
Next, a modification of the present embodiment will be described with reference to FIGS. As a modified example, as shown in FIG. 8, the first lid 32 is vertically moved in the drawing so that two gap spaces S2 and S3 are formed inside the first lid 32 of the pressurizing unit 31. May be provided so as to form a two-layer structure.

Specifically, a gap space S3 for releasing air in the gap space S1 defined by the outer peripheral surface of the thin tube 21 is arranged in the upper stage of the first lid 32. In addition, an air hole 50 is formed in the outer wall of the first lid 32 to communicate with the gap space S3 and allow air to escape to the outside. Further, a gap space S2 for pressurizing the internal space of the thin tube 21 is disposed below the first lid 32, as in the present embodiment. A channel 34 communicating with the gap S2 is formed on the outer wall of the first lid 32, and the gap S2 is pressurized through the channel 34.
Similarly, in the present modified example, the first lid 32 is also provided with a first mesh portion (mesh portion) 35 that partitions the gap space S2 from the outside on the flange portion 33 side.

  A second mesh portion 51 that partitions the gaps S2 and S3 is provided between the gaps S2 and S3. As shown in FIG. 8 and FIG. 9 (A), when the first lid 32 is fitted on the structure A, the second mesh portion 51 has a gap space S1 defined by the outer peripheral surface of the thin tube 21. A plurality of through holes 51A are formed at positions corresponding to (see FIG. 7A). At the lower end surface of the second mesh portion 51, a plurality of pipes 52 that respectively communicate with the through holes 51A of the second mesh 51 extend downward and are integrally provided. At this time, as shown in FIG. 9 (B), when the first lid 32 is fitted to the structure A, the tube 52 corresponds to the gap space S1 defined by the outer peripheral surface of the thin tube 21. Will be placed. Therefore, the internal space of the tube body 52 communicates with the gap space S1.

  As described above, as shown in FIG. 9C, the first mesh portion 35 includes the same first through-hole (through-hole) 35A as in the above-described embodiment and the first through-hole 35A. And a plurality of second through holes 35B each having a small diameter. The second through-hole 35B of the first mesh portion 35 is located at a position corresponding to the gap space S1 defined by the outer peripheral surface of the thin tube 21 when the first lid 32 is fitted to the structure A. Respectively formed. Then, as shown in FIGS. 8 and 9, each tube 52 is formed so as to bridge between the second through hole 35B of the first mesh portion 35 and the through hole 51A of the second mesh portion 51. Is done.

In this modification, when the structure A is pulled while pressurizing the structure A through the space S2, the air in the space S1 partitioned by the outer peripheral surface of the thin tube 21 is removed from the internal space of the tube 52, the space S3. And can escape to the outside through the air holes 50. Thus, the sectional shape of the thin tube 21 after being pulled can be formed more uniformly and accurately.
In addition, not only air may naturally escape from the air holes 50, but also air may be sucked and air may be positively removed. At this time, if air is excessively sucked, the outer periphery of the thin tube 21 crushes a part of the gap space S1 and is located below the stack 10 in the height direction of the stack 10 (on the second lid 36 side). Welding may occur with air remaining in the gap space S1. For this reason, it is desirable to appropriately adjust the amount per unit time of suction.

<The manufacturing method of the stack for thermoacoustic devices of the present embodiment, the manufacturing device thereof, and the advantages of the thermoacoustic device>
As described above, according to the method for manufacturing the thermoacoustic device stack 10, the manufacturing device 30 for the thermoacoustic device stack 10, and the thermoacoustic device 1 of the present embodiment, the plurality of thin tubes 21 are bundled with their axial directions aligned. In this case, the gap space S1 between the adjacent thin tubes 21 is filled in the manufacturing process, and the cross-sectional shape and distribution of each through hole 11A of the stack 10 are formed substantially uniformly. By pulling while applying pressure, the cross-sectional shape and dimensions of the through-holes 11A of the stack 10 are made uniform and the diameter of the through-holes 11A is prevented from becoming excessively small. The holes 11A can be provided as densely as possible. Thereby, the ratio of the through holes 11A to the cross section of the stack 10 increases, and the aperture ratio of the stack 10 can be improved. That is, by appropriately setting the pressure for pressurizing the internal space of the thin tube 21 and the distance for pulling one end of the structure A, it is possible to improve the aperture ratio of the stack 10 before the structure A is pulled. Further, the grid of the cross section of the stack 10 becomes finer, and the grid smoothly continues in the longitudinal direction. As a result, pressure loss can be reduced while reducing ωτ. In addition, since the structure A is provided by being pulled in the longitudinal direction as compared with the case where the stack 10 is similarly reduced and manufactured from the structure A, more stacks 10 can be cut out, Manufacturing costs can be reduced. In addition, even if an inexpensive thin tube 21 having a circular cross section is used, a flow path originating from the gap space S1 is not provided, so that the stack 10 which is inexpensive and energy efficient can be manufactured. As described above, the energy exchange efficiency can be improved, and an increase in manufacturing cost can be suppressed.

  According to the method for manufacturing the thermoacoustic device stack 10 and the thermoacoustic device stack 10 manufacturing device 30 of the present embodiment, the axial end of the storage tube 22 of the structure A is sandwiched and pulled. Since the one end of the structure A in the axial direction is pulled, the plurality of thin tubes 21 stored in the storage tube 22 can be uniformly pressed inward in the radial direction. Can be more uniformly and accurately formed.

  This concludes the description of specific embodiments, but aspects of the present invention are not limited to these embodiments, and modifications and improvements can be made as appropriate.

Here, the method for manufacturing the thermoacoustic device stack, the manufacturing device for the thermoacoustic device stack, and the features of the thermoacoustic device according to the present invention described above will be briefly summarized and listed in the following [1] to [4].
[1]
A plurality of thin tubes (21) are bundled in the same axial direction, and the bundled plural thin tubes (21) are contained in a storage tube (22) whose inner shape is substantially equal to the outer shape of the plural thin tubes (21). A welding step of heating the plurality of thin tubes (21) and forming a structure (A) in which the adjacent thin tubes (21) are welded to each other,
A pressurizing step of pressurizing each of the internal spaces of the thin tube (21) of the structure (A) at a pressure higher than an external pressure;
A tension step of heating one axial end of the structure (A) and pulling the one axial end of the structure (A) along the axial direction;
A method for manufacturing a stack (10) for a thermoacoustic device, comprising:
[2]
The one end in the axial direction of the structure (A) is pulled by holding and pulling the one end in the axial direction of the storage tube (22) of the structure (A). The manufacturing method of the stack (10) for thermoacoustic apparatuses described in the above.
[3]
A plurality of thin tubes (21) are bundled together in the axial direction, and are housed in a storage tube (22) whose inner shape is substantially equal to the outer shape of the bundled thin tubes (21). And pressurizing each of the internal spaces of the thin tubes (21) of the structure (A) with a pressure higher than the outside pressure with respect to the structure (A) in which the adjacent thin tubes (21) are welded to each other. Part (31),
A tension portion (38) for gripping the axial end of the structure (A) having the heated axial end and pulling the axial end along the axial direction;
An apparatus (30) for producing a stack (10) for a thermoacoustic device, comprising:
[4]
A plurality of thin tubes (21) bundled in the axial direction are housed inside a storage tube (22) having an inner diameter substantially equal to the outer shape of the plurality of thin tubes (21), and the adjacent thin tubes (21) are adjacent to each other. Is welded, and one end in the axial direction of the structure (A) extends along the axial direction in a state where the internal space of the thin tube (21) is pressurized at a pressure higher than the outside air pressure. A thermoacoustic device (1), characterized in that it has a stack formed by pulling.

1 Thermoacoustic engine (thermoacoustic device)
2 Tube 3 High-temperature side heat exchanger 4 Low-temperature side heat exchanger 5 High-temperature heat source 6 Low-temperature heat source 10 Stack for thermoacoustic device 11 Main body 11A Through hole 21 Thin tube 21A Through hole 22 Storage tube 22A Through hole 30 Manufacture of stack for thermoacoustic device Apparatus 31 Pressurizing part 32 First lid 33 Flange part 34 Flow path 35 Mesh part (first mesh part)
35A Through hole (first through hole)
35B Second through-hole 36 Second lid 37 Flange 38 Tension unit 39 Arm 40 Gripping unit 41 Cutting machine 50 Air hole 51 Second mesh unit 51A Through-hole 52 Tube F Working fluid A Structure S1 Gap space S2 Clearance space S3 Clearance space

Claims (4)

A plurality of thin tubes are bundled in the same axial direction, and the bundled thin tubes are housed in a storage tube having an inner shape substantially equal to the outer shape of the plurality of thin tubes. A welding step of heating to form a structure in which the adjacent thin tubes are welded to each other;
A pressurizing step of pressurizing each of the internal spaces of the thin tube of the structure at a pressure higher than an external pressure;
A tensioning step of heating one axial end of the structure, and pulling the one axial end of the structure along the axial direction,
A method for manufacturing a stack for a thermoacoustic device, comprising: 2. The manufacturing of the thermoacoustic device stack according to claim 1, wherein the axial end of the structure is pulled by holding and pulling the axial end of the storage tube of the structure. 3. Method. A plurality of thin tubes are bundled together in the axial direction, and the adjacent thin tubes are welded to each other in a state where the inner shape is housed in a housing tube having an inner shape substantially equal to the outer shape of the bundled thin tubes. For the structure, a pressurizing unit that pressurizes each of the internal spaces of the thin tubes of the structure with a pressure higher than the outside pressure.
A tension portion that grips the one axial end of the structure whose one axial end is heated, and pulls the one axial end along the axial direction,
An apparatus for manufacturing a stack for a thermoacoustic device, comprising: A plurality of thin tubes bundled in the same axial direction are housed inside a housing tube having an inner diameter substantially equal to the outer shape of the plurality of thin tubes, and a structure in which adjacent thin tubes are welded to each other is formed inside the thin tube. A thermoacoustic apparatus comprising: a stack formed by pulling one end in the axial direction of the structure along the axial direction in a state where each space is pressurized at a pressure higher than the external pressure.

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