JP2004052866A - Pressure vessel and engine using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressure vessel and an engine using the same capable of preventing deterioration of performance and reducing the manufacturing cost and noise. <P>SOLUTION: The pressure vessel 20 is divided into a shell part 21 and an end plate 22. A cylindrical part 22 and a spherical surface part 22b which are internally inserted into the shell part 21, are provided on the end plate 22. The cylindrical part 22a is welded to the shell part 21 so that the end surface of the cylindrical part 22a is arranged in the inner side and the outside of the spherical surface becomes convex. An extended part 21a extending in the axial direction from the welded part with the end plate 22 is provided on the shell part 21. Noise is prevented by covering a dynamic vibration absorber 35 mounting the dynamic vibration absorber 35 on the extending part 21a. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a pressure vessel in which an internal space is sealed. The present invention also relates to an engine such as a refrigerator or a compressor having a reciprocating drive unit such as a linear motor in a pressure vessel.
[0002]
In general, a refrigerator employs a vapor compression refrigeration cycle utilizing condensation and evaporation of a refrigerant. However, fluorocarbon used as a refrigerant in a vapor compression refrigeration cycle has been pointed out to have an adverse effect on the environment due to destruction of the ozone layer, and its use and production have been regulated in recent years.
[0003]
For this reason, a Stirling refrigerator using a Stirling engine with a reverse Stirling refrigeration cycle has been proposed instead of a refrigeration cycle using Freon. Since the reverse Stirling refrigeration cycle uses helium gas, hydrogen gas, nitrogen gas, or the like as a working medium, adverse effects on the environment can be prevented.
[0004]
In the Stirling refrigerator, a piston and a displacer are arranged in a cylinder arranged in a pressure vessel via a compression space in an axial direction, and an expansion space communicating with the compression space is provided at a tip of the displacer. By the reciprocating motion of the piston and the displacer with a predetermined phase difference, the working medium is compressed in the compression space and expands in the expansion space, so that the temperature of the expansion space can be lowered.
[0005]
Since a high-pressure gas is sealed in the pressure vessel, the pressure vessel is required to have pressure resistance. Therefore, as disclosed in, for example, JP-A-2001-57767, a pressure vessel is formed by welding two casings having a U-shaped cross section by drawing. However, the cylinder provided in the pressure vessel has a longer axial length because the piston and the displacer that move at a predetermined stroke are fitted inside. For this reason, since the casing in which the cylinder is housed is formed by repeatedly performing the drawing process a plurality of times, there has been a problem that the manufacturing cost is increased.
[0006]
In order to solve this problem, as shown in FIG. 9, a pressure vessel 20 in which a casing 3 is formed by welding a head plate 22 that covers an opening of a body 21 to a cylindrical body 21 is formed into an “A Summary of”. Twenty Ears Experience with Linear Motors and Alternators ", Robert Redlich, Sunpower Inc. , 1996.
[0007]
The end plate 22 has a cylindrical portion 22a fitted inside the body portion 21 and a spherical portion 22b having a predetermined radius of curvature, and the cylindrical portion 22a is welded to the body portion 21 to ensure a sealed state of the pressure vessel 20. I have. Thereby, the cost of the pressure vessel 20 can be reduced.
[0008]
Further, since the piston and the displacer which are fitted in the cylinder reciprocate, a back pressure is applied to the pressure vessel in a direction opposite to the moving direction of the piston and the displacer. As a result, the pressure vessel vibrates at a predetermined cycle, and a dynamic vibration absorber is attached to the pressure vessel as disclosed in JP-A-2000-88383.
[0009]
FIG. 10 is a diagram showing an example of a Stirling refrigerator provided with a dynamic vibration absorber. A plurality of support members 36 are welded to the peripheral surface of the pressure vessel 20 that covers the Stirling refrigerator 1. The dynamic vibration absorber 35 is fixed to the support member 36 by mounting screws 37. The dynamic vibration absorber 35 is configured by attaching a load weight 39 having a predetermined mass to a leaf spring 38. Therefore, the Stirling refrigerator 1 with less vibration can be obtained by absorbing the vibration of the pressure vessel 20 by the inertial force of the load weight 39.
[0010]
[Problems to be solved by the invention]
However, according to the pressure vessel 20 shown in FIG. 9, the end surface of the cylindrical portion 22a is formed to face outward, and the spherical portion 22b is formed to project outward. For this reason, a boundary portion 22c is formed between the spherical portion 22b and the cylindrical portion 22a, where the center of the radius of curvature is arranged outside the pressure vessel 20. Since an outward pressure is applied to the pressure vessel 20 as indicated by an arrow R, pressure is applied to the boundary portion 22c in a direction in which the end plate 22 is separated from the cylindrical portion 22a as indicated by an arrow A.
[0011]
As a result, the upper portion C of the end plate 22 has a large deformation due to the pressing force (R) in the axial direction and the pressing force (A) applied to the boundary portion 22c. Accordingly, the change in the back pressure of the piston due to the change in volume in the pressure vessel 20 becomes large, and the compression force by the piston fluctuates, so that there is a problem that desired performance cannot be obtained. Further, not only in the Stirling refrigerator, but also in an engine having a pressure vessel that seals the inside thereof, there is a problem that the performance is deteriorated due to a large change in the internal volume, and a problem that a high assembling accuracy is required and the manufacturing cost is increased. .
[0012]
On the other hand, the Stirling refrigerator shown in FIG. 10 requires a support member 36 to which the dynamic vibration absorber 35 is attached. Further, since the dynamic vibration absorber 35 is disposed open to the outside, there is a problem that the noise generated by the dynamic vibration absorber 35 increases. A similar problem occurs when a dynamic vibration absorber is provided not only in the Stirling refrigerator 1 but also in a device in which a reciprocating drive unit that reciprocates in a sealed pressure vessel is provided.
[0013]
An object of the present invention is to provide a pressure vessel and an engine that can reduce performance degradation and manufacturing cost. Another object of the present invention is to provide an engine having a dynamic vibration absorber capable of reducing noise and manufacturing cost.
[0014]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a pressure vessel having a cylindrical body having an opening at one end, a head plate closed to the body by closing the opening, and a sealed inside of the body. In an engine using the same, the end plate is characterized in that it has a cylindrical portion fitted to the body portion, and a spherical portion that covers the opening and is protruded to the side away from the end face of the cylindrical portion.
[0015]
According to this configuration, for example, a force for deforming outwardly is applied to the upper portion of the shaft of the head plate by the internal pressure of the pressure vessel, and a force for deforming inwardly is applied to the upper portion of the shaft of the head plate by the pressure applied to the body. Therefore, these forces cancel each other out, the amount of deformation of the upper portion of the end plate is small, and the fluctuation of the internal volume of the pressure vessel is reduced. The engines include Stirling refrigerators and linear motor driven compressors.
[0016]
The present invention also provides a reciprocating drive that reciprocates in a pressure vessel that has a cylindrical body having an opening at one end and a head plate that covers the opening and is fixed to the body, and the inside of which is hermetically sealed. In the engine in which the parts are arranged, an extended part extending in the axial direction from the joint with the head plate is formed on the trunk, and a dynamic vibration absorber that absorbs vibration by the reciprocating drive part is attached to the extended part. I have. According to this configuration, the dynamic vibration absorber is attached to the pressure vessel by simplifying the support member by the extension provided on the body. Thereby, the dynamic vibration absorber is disposed in a state of being surrounded by the body.
[0017]
Further, the present invention reciprocates in a pressure vessel having a cylindrical body having an opening at one end and a head plate closing the opening and being fixed to the body, and hermetically sealed therein. An engine provided with a reciprocating drive unit is characterized in that a dynamic vibration absorber for absorbing vibration by the reciprocating drive unit is attached to the head plate. According to this configuration, the dynamic vibration absorber is attached to the pressure vessel without the need for a separate support member by the end plate, and the dynamic vibration absorber is disposed in a state surrounded by the body.
[0018]
Further, according to the present invention, in the engine having the above-mentioned configuration, the end plate has a cylindrical portion fitted to the body portion, and the dynamic vibration absorber is attached to an extended portion extending from the cylindrical portion outward in the axial direction. According to this configuration, the support member is simplified by the extending portion provided in the cylindrical portion, and the dynamic vibration absorber is attached to the pressure vessel. As a result, the dynamic vibration absorber is disposed in a state of being surrounded by the extension of the end plate. Further, the head plate and the dynamic vibration absorber can be integrated into a unit.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view showing the Stirling refrigerator of the first embodiment. For convenience of description, the same parts as those in FIGS. 9 and 10 of the conventional example are denoted by the same reference numerals. The Stirling refrigerator 1 shown here as an example is covered by a pressure vessel 20 composed of stainless steel casings 2 and 3 having a U-shaped cross section.
[0020]
A flange 2a is projected from the casing 2, and the casing 3 is welded to the flange 2a to seal the inside. The casing 3 is formed by welding a head plate 22 to the tip of a cylindrical body 21. The end plate 22 has a cylindrical portion 22a fitted inside the body portion 21 and a spherical portion 22b composed of a spherical surface. The end surface of the cylindrical portion 22a is inside the pressure vessel 20, and the spherical portion 22b is convex outside. It is formed as follows.
[0021]
A substantially cylindrical cylinder 7 divided in the axial direction is disposed in the pressure vessel 20, and a cylindrical piston 15 and a displacer 8 are fitted in the cylinder 7. The piston 15 and the displacer 8 are coaxially arranged via the compression space 9. An expansion space 14 is provided between the tip of the cylinder 7 and the displacer 8.
[0022]
The compression space 9 and the expansion space 14 communicate with each other through a medium flow passage 11 through which a working medium such as helium flows. A regenerator 10 that stores heat of the working medium and supplies the stored heat to the working medium is disposed in the medium flow passage 11. At both ends of the regenerator 10, heat absorbing fins 12 and heat radiating fins 13 are provided.
[0023]
The piston 15 is integrated with the piston support spring 30 at the rear end, and the displacer 8 is integrated with the displacer support spring 31 via the rod 4 that passes through the center hole 15a of the piston 15. The piston support spring 30 and the displacer support spring 31 are connected by a bolt 32. As will be described later, when the piston 15 reciprocates, the displacer 8 reciprocates with a predetermined phase difference with respect to the piston 15 due to its inertial force.
[0024]
An inner yoke 18 is externally fitted to the cylinder 7 in the casing 3. The outer yoke 17 faces the inner yoke 18 via a gap 19. A driving coil 16 is provided in the outer yoke 17, and an annular permanent magnet 26 is movably disposed in the gap 19. The permanent magnet 26 is integrated with the biston 15 via a cup-shaped sleeve 25. Thus, a linear motor 24 that moves the piston 15 in the axial direction by applying a voltage to the driving coil 16 is configured.
[0025]
In the Stirling refrigerator 1 having the above configuration, when the piston 15 reciprocates by the linear motor 24, the displacer 8 reciprocates with a predetermined phase difference with respect to the piston 15 due to the inertial force of the displacer 8. As a result, the working medium moves between the compression space 9 and the expansion space 14, and a reverse Stirling cycle is performed. That is, the heat generated in the compression space 9 on the high-temperature side due to the compression of the working medium is released to the atmosphere through the radiation fins 13, and the working medium accumulates heat in the regenerator 10 to expand the expansion space 14. Move to
[0026]
The working medium cooled by the regenerator 10 is further cooled by being expanded in the expansion space 14 on the low temperature side. Then, when the working medium moves to the compression space 9 through the medium flow passage 11, the heat stored in the regenerator 10 is taken away and the regenerator 10 is cooled. The refrigerating cycle is performed by repeating this operation.
[0027]
FIG. 2 shows the pressure applied to the casing 3. As shown by an arrow R, pressure is applied to the body portion 21 and the cylindrical portion 22a in a direction of expanding outward in the radial direction. Pressure is applied to the spherical portion 22b in the axial direction in addition to the radial component. The shaft upper portion C of the end plate 22 receives a force on the inner side of the compression container 20 as the cylindrical portion 22a expands in the radial direction. For this reason, in the upper shaft portion C, the force acting outward in the axial direction due to the internal pressure and the force acting inward due to the pressure applied to the cylindrical portion 22a cancel each other, and as a result, the deformation of the upper shaft portion C of the end plate 22 can be prevented. it can.
[0028]
Therefore, since it is separated into the body portion 21 and the end plate 22, it is not necessary to perform a plurality of drawing processes, so that the manufacturing cost of the Stirling refrigerator 1 can be reduced and the change in the internal volume of the pressure vessel 20 is small. In addition, the back pressure of the cylinder 15 is stabilized, and performance degradation can be prevented. In addition, the cylindrical portion 22 a of the end plate 22 may be fitted to the body 21.
[0029]
Next, FIG. 3 is a side sectional view showing a Stirling refrigerator of a second embodiment. For convenience of explanation, the same parts as those in the first embodiment shown in FIG. 1 are denoted by the same reference numerals. In the present embodiment, the shape of the casing 3 is different from that of the first embodiment, and a head plate 22 having the same shape as that of the first embodiment is arranged so that the inside of the compression container 20 becomes convex. Other parts are the same as in the first embodiment.
[0030]
According to the present embodiment, pressure is applied to the body portion 21 in the radially outward direction, so that bending stress is applied to the cylindrical portion 22a welded to the body portion 21 in the radially inward direction as indicated by the arrow B. . As a result, the upper shaft portion C of the end plate 22 tends to deform inside the pressure vessel. For this reason, the force acting outward in the axial direction due to the internal pressure and the force acting inward in the axial direction due to the bending stress applied to the cylindrical portion 22a cancel out the upper portion C of the end plate 22 as a result. Deformation can be prevented. Therefore, the same effect as in the first embodiment can be obtained.
[0031]
Next, FIG. 4 is a side sectional view showing a Stirling refrigerator of a third embodiment. For convenience of explanation, the same reference numerals are given to the same parts as those in the first embodiment and the conventional example shown in FIGS. 1 and 10 described above. In the present embodiment, a dynamic vibration absorber 35 is disposed in the pressure vessel 20 in addition to the Stirling refrigerator of the first embodiment. Other parts are the same as in the first embodiment.
[0032]
The dynamic vibration absorber 35 is fixed to the end plate 22 by mounting screws 37. The dynamic vibration absorber 35 is configured by attaching a load weight 39 having a predetermined mass to a leaf spring 38. Therefore, the Stirling refrigerator 1 with less vibration can be obtained by absorbing the vibration of the pressure vessel 20 due to the reciprocating motion of the piston 15 by the inertial force of the load weight 39.
[0033]
According to the present embodiment, the same effect as that of the first embodiment can be obtained, and the number of components can be reduced without the need for the support member 36 shown in the conventional example of FIG. Further, since the dynamic vibration absorber 35 is surrounded by the body 21 of the pressure vessel 20, the noise of the Stirling refrigerator 1 can be reduced.
[0034]
Next, FIG. 5 is a side sectional view showing a Stirling refrigerator of a fourth embodiment. For convenience of explanation, the same reference numerals are given to the same parts as those in the first embodiment and the conventional example shown in FIGS. 1 and 10 described above. In the present embodiment, a dynamic vibration absorber 35 is disposed outside the pressure vessel 20 in addition to the Stirling refrigerator of the first embodiment. Other parts are the same as in the first embodiment.
[0035]
An extension 21 a is formed in the body 21 of the casing 3 so as to extend in the axial direction from a joint with the end plate 22. An annular fixing portion 34 is welded to an end of the extension portion 21a, and the dynamic vibration absorber 35 is fixed to the fixing portion 34 by a mounting screw 37. Similarly to the above, the dynamic vibration absorber 35 is configured by attaching a load weight 39 having a predetermined mass to a leaf spring 38. Thereby, the Stirling refrigerator 1 which absorbs the vibration of the pressure vessel 20 and has less vibration can be obtained.
[0036]
According to this embodiment, the same effect as that of the first embodiment can be obtained, and the fixing part 34 is required instead of the support member 36 shown in the conventional example of FIG. 10 described above. Parts cost can be reduced. Further, since the dynamic vibration absorber 35 is surrounded by the extending portion 21a and the fixing portion 34, the noise of the Stirling refrigerator 1 can be reduced.
[0037]
Next, FIG. 6 is a side sectional view showing a Stirling refrigerator of a fifth embodiment. For convenience of explanation, the same reference numerals are given to the same parts as those in the fourth embodiment shown in FIG. 5 and the conventional example. This embodiment is different from the fourth embodiment in the shape of the end plate 22. Other parts are the same as in the fourth embodiment.
[0038]
The end plate 22 of the present embodiment is configured similarly to the end plate 22 of the conventional example shown in FIG. For this reason, it is not possible to prevent a change in the internal volume of the pressure vessel 20. However, as in the fourth embodiment, the configuration of the fixing portion 34 is more simplified than that of the conventional supporting member 36, and the cost of parts is reduced. Can be. Further, since the dynamic vibration absorber 35 is surrounded by the extending portion 21a and the fixing portion 34, noise of the Stirling refrigerator 1 can be reduced. As shown in the sixth embodiment in FIG. 7, a fixing plate 34 may be attached to the end of the casing 3 by screws 33.
[0039]
Next, FIG. 8 is a side sectional view showing a Stirling refrigerator of a seventh embodiment. For convenience of explanation, the same reference numerals are given to the same parts as those in the fourth embodiment shown in FIG. 5 and the conventional example. In the fourth embodiment, the fixed plate 34 integrated with the dynamic vibration absorber 5 is attached to the extending portion 21a (see FIG. 5) that extends the trunk portion 21. In the present embodiment, the end plate 22 extends in the axial direction. The fixing plate 34 is attached to the installation portion 22d. Other parts are the same as in the fourth embodiment.
[0040]
The end plate 22 of this embodiment is formed in the same shape as the end plate 22 of the conventional example shown in FIG. 9 described above, and is provided with an extended portion 22d extending from the cylindrical portion 22a. The fixed plate 34 integrated with the dynamic vibration absorber 5 is attached to the extending portion 22d. Therefore, as in the fifth embodiment, it is not possible to prevent a change in the internal volume of the pressure vessel 20. However, it is possible to simplify the configuration and reduce the component cost by using the fixing part 34 as compared with the related art.
[0041]
Further, since the dynamic vibration absorber 35 is covered by the extending portion 22d and the fixing portion 34, the noise of the Stirling refrigerator 1 can be reduced. In addition, since the end plate 22 and the dynamic vibration absorber 5 are configured as a unit, the Stirling refrigerator 1 can be more easily assembled.
[0042]
Although the free piston type Stirling refrigerator is described in the first to seventh embodiments, the same applies to an engine in which a reciprocating drive unit that reciprocates by a linear motor or the like is arranged in a sealed pressure vessel. The effect of can be obtained. For example, a two-piston Stirling refrigerator, a refrigerator that operates a Vermier cycle to perform cooling, or a compressor driven by a linear motor may be used.
[0043]
【The invention's effect】
According to the present invention, since the pressure vessel is separated into the body and the end plate, it is not necessary to perform drawing a plurality of times, so that the manufacturing cost can be reduced, and the cylindrical portion in which the end plate is fitted to the body. And the spherical portion that closes the opening and is convex on the side away from the end surface of the cylindrical surface, so that the change in the internal volume of the pressure vessel due to the internal pressure is small, and the back pressure of the reciprocating drive unit is stable and performance deteriorates Can be prevented. Further, high assembly accuracy is not required, and an increase in manufacturing cost can be prevented.
[0044]
Further, according to the present invention, since the dynamic vibration absorber is attached to the body or the end plate of the pressure vessel by providing an extended portion extending in the axial direction from the junction between the body and the end plate, the support member is simplified and the manufacturing cost is reduced. Can be reduced. Further, the noise of the dynamic vibration absorber can be prevented by surrounding the dynamic vibration absorber with the extending portion.
[0045]
Further, according to the present invention, since the dynamic vibration absorber is arranged in the pressure vessel, the manufacturing cost can be reduced by eliminating the support member, and noise can be prevented by covering the dynamic vibration absorber with the pressure vessel.
[Brief description of the drawings]
FIG. 1 is a side sectional view showing a Stirling refrigerator according to a first embodiment of the present invention.
FIG. 2 is a diagram illustrating pressure applied to a pressure vessel of the Stirling refrigerator according to the first embodiment of the present invention.
FIG. 3 is a side sectional view showing a Stirling refrigerator according to a second embodiment of the present invention.
FIG. 4 is a side sectional view showing a Stirling refrigerator according to a third embodiment of the present invention.
FIG. 5 is a side sectional view showing a Stirling refrigerator according to a fourth embodiment of the present invention.
FIG. 6 is a side sectional view showing a Stirling refrigerator according to a fifth embodiment of the present invention.
FIG. 7 is a side sectional view showing a Stirling refrigerator according to a sixth embodiment of the present invention.
FIG. 8 is a side sectional view showing a Stirling refrigerator according to a seventh embodiment of the present invention.
FIG. 9 is a side sectional view showing a pressure vessel of a conventional Stirling refrigerator.
FIG. 10 is a side sectional view showing a conventional Stirling refrigerator.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Stirling refrigerator 2, 3 Casing 4 Rod 7 Cylinder 8 Displacer 9 Compression space 10 Regenerator 11 Refrigerant flow path 12 Heat absorption fin 13 Radiation fin 14 Expansion space 15 Piston 16 Drive coil 20 Pressure vessel 21 Body 21a, 22d Extension Part 22 End plate 22a Cylindrical part 22b Spherical part 25 Sleeve 26 Permanent magnet 34 Fixed member 35 Dynamic vibration absorber 36 Support member 39 Load weight

Claims (8)

In a pressure vessel having a cylindrical body having an opening at one end, and a head plate that closes the opening and is fixed to the body, the inside of the body is sealed.
The pressure vessel according to claim 1, wherein the end plate has a cylindrical portion fitted to the body portion, and a spherical portion that covers the opening and is formed to project away from an end surface of the cylindrical portion. A reciprocating drive unit that reciprocates is disposed in a pressure vessel that has a cylindrical body having an opening at one end and a head plate that closes the opening and is fixed to the body, and is hermetically sealed. Institutions that
The engine according to claim 1, wherein the end plate has a cylindrical portion fitted to the body portion, and a spherical portion that covers the opening and that is formed to project away from an end surface of the cylindrical portion. An extended portion extending in the axial direction from a joint portion with the end plate is formed on the body portion, and a dynamic vibration absorber for absorbing vibration by the reciprocating drive portion is attached to the extended portion. 2. The institution according to 2. A reciprocating drive unit that reciprocates is disposed in a pressure vessel that has a cylindrical body having an opening at one end and a head plate that closes the opening and is fixed to the body, and is hermetically sealed. Institutions that
An engine, wherein an extension portion extending in the axial direction from a joint portion with the end plate is formed on the trunk portion, and a dynamic vibration absorber for absorbing vibration by the reciprocating drive portion is attached to the extension portion. A reciprocating drive unit that reciprocates is disposed in a pressure vessel that has a cylindrical body having an opening at one end and a head plate that closes the opening and is fixed to the body, and is hermetically sealed. Institutions that
An engine, wherein a dynamic vibration absorber that absorbs vibration from the reciprocating drive unit is disposed in a state surrounded by the body. A reciprocating drive unit that reciprocates is disposed in a pressure vessel that has a cylindrical body having an opening at one end and a head plate that covers the opening and is fixed to the body and that is hermetically sealed. Institutions that
An engine, wherein a dynamic vibration absorber for absorbing vibration by the reciprocating drive unit is attached to the head plate. The engine according to claim 6, wherein the end plate has a cylindrical portion fitted to the body portion, and the dynamic vibration absorber is attached to an extended portion extending from the cylindrical portion outward in the axial direction. A reciprocating drive unit that reciprocates is disposed in a pressure vessel that has a cylindrical body having an opening at one end and a head plate that closes the opening and is fixed to the body, and is hermetically sealed. Institutions that
An engine, comprising: an extension part extending the head plate outward in the axial direction; and a dynamic vibration absorber that absorbs vibrations from the reciprocating drive part, which is disposed in a state surrounded by the extension part.

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