KR20070073973A - Piezoelectric pump and stirling refrigerator - Google Patents

Abstract

A piezoelectric pump and a Stirling refrigerator. The piezoelectric pump (6) comprises a casing (32) formed by welding a plurality of metal members to each other, a piezoelectric element (36) partitioning a space in the casing (32) into an operating space (34) and a back pressure space (35), and resin internal parts (33A, 33B) installed between the casing (32) and the piezoelectric element (36) and holding the piezoelectric element (36). The internal parts (33A, 33B) are formed of an easy-to-machine and easy-to-mold resin. The internal part (33A) specifies the outer periphery of the operating space (34) and the internal part (33B) specifies the outer periphery of the back pressure space (35). Since a recessed part is formed between the internal parts (33A, 33B) by facing the internal parts (33A, 33B) each other, the piezoelectric element (36) can be holdingly stored in the recessed part.

Description

Piezoelectric Pumps and Sterling Coolers {PIEZOELECTRIC PUMP AND STIRLING REFRIGERATOR}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric pump and a Stirling Refrigerator / Freezer, and more particularly to a piezoelectric pump and a piezoelectric pump for circulating fluid efficiently in a negative pressure and a static pressure state. Sterling cooler.

As a pump for circulating a medium, a piezoelectric pump using a piezoelectric element such as quartz or lithium niobate has been conventionally used.

6 is a sectional view showing an example of a conventional piezoelectric pump. Referring to FIG. 6, the piezoelectric pump 106 includes a casing 132, and an operating space 134 and a back pressure space 135 in the casing 132 as shown in FIG. Here, the working space 134 and the back pressure space 135 are partitioned by the piezoelectric element 136. In addition, an inlet 137 for sucking the medium and an outlet 138 for discharging the medium are provided in the casing on the working space 134 side, and the back pressure space 135 in the casing on the back pressure space 135 side. The back pressure hole 135A for adjusting the pressure of) is provided. In addition, check valves 139 and 140 are provided at the inlet 137 and the outlet 138 to prevent the medium from flowing back.

When the piezoelectric pump 106 is operated, an electrical signal is applied to the piezoelectric element 136. Thereby, the piezoelectric element 136 amplitude-moves in the direction of a broken arrow in FIG. At this time, the end portion of the piezoelectric element 136 is fixed to the casing 132, and the piezoelectric element 136 is interlocked in amplitude while being deformed into a convex surface shape. As a result, the volume of the working space 134 fluctuates, and the pressure in the working space 134 fluctuates in accordance with the deformation state of the piezoelectric element 136 to suck / discharge the medium.

Here, the volume of the back pressure space 135 is also changed by the deformation of the piezoelectric element 136. As a result, if the pressure in the back pressure space 135 varies, the direction of movement of the piezoelectric element 136 in the opposite direction to that of the piezoelectric element 136 is changed. Force is generated, and as a result, the operating efficiency of the piezoelectric pump 106 is lowered. On the other hand, the back pressure hole 135A is provided in the back pressure space 135 side of the casing 132 so that the pressure of the back pressure space 135 becomes constant irrespective of the deformation state of the piezoelectric element 136.

Moreover, as what applied the heat exchange by a reverse-stering cycle to a refrigerator, what was described in Unexamined-Japanese-Patent No. 2003-50073 (Prior Example 1) etc. are mentioned, for example.

In the prior art example 1, the high temperature part for radiating the heat of compression of the working gas by a reverse stirring cycle to the outside, the low temperature part for absorbing the expansion heat of the working gas by a reverse stirring cycle from the outside, and thermally couple | bonded with the low temperature part. A low temperature side circulation circuit comprising a closed circuit in which a low temperature side condenser and a plurality of low temperature side evaporators are connected to form a thermophon (thermosyphon), and a cold transfer medium for conveying the cold heat of the low temperature portion are enclosed in the low temperature side circulation circuit. A sterling refrigeration system is disclosed. Here, the heat in the high temperature portion is radiated by the high temperature side heat exchange cycle (heat dissipation system). The high temperature side heat exchange cycle comprises a high temperature side evaporator and a high temperature side condenser connected by piping, and heat is conveyed and discharged by the thermosiphon principle.

In addition, in Korean Utility Model Publication No. 2505727 (Prior Example 2), a piezoelectric pump including a casing, a piezoelectric vibrator provided inside the casing, and a suction and discharge check valve provided in one pump chamber of the piezoelectric vibrator is provided. Is disclosed. In this piezoelectric pump, a half pump chamber located on the opposite side to the pump chamber communicates with the pump chamber and the piezoelectric vibrator.

Patent Document 1: Japanese Patent Publication No. 2003-50073

Patent Document 2: Registered Utility Model Publication No. 2505727

However, the above-described piezoelectric pumps have the following problems.

In the piezoelectric pump as shown in Fig. 6, the casing is constituted by using a plurality of opposing members to form a space therein. Here, sealing between a some member is generally performed using O-ring etc. In such a configuration, since a slow leak of the working medium occurs, the system can be used continuously for a long time in a closed system in which the pressure in the circuit is lower or higher than atmospheric pressure (hereinafter referred to as negative pressure or static pressure). none. Such a problem is not solved even by the piezoelectric pump shown in the prior art example 2.

In addition, since the piezoelectric element used in the piezoelectric pump has low heat resistance, when joining the plurality of members by welding to improve the sealing property, the problem is how to make the heat of welding difficult to be transmitted to the piezoelectric element. . By reducing the amount of heat transferred to the piezoelectric element, the function of the piezoelectric element is improved, and consequently, the circulation efficiency of the fluid is improved.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a piezoelectric pump and a sterling cooler for efficiently circulating a fluid in a negative pressure and a static pressure state.

A piezoelectric pump according to the present invention includes a casing formed by joining a plurality of metal members, a piezoelectric element for partitioning a space in the casing into first and second internal spaces, and a piezoelectric element provided between the casing and the piezoelectric element. And supporting first and second internal parts made of nonmetal.

It is preferable that the some metal member which comprises a casing is joined by welding. By joining the members by welding, the durability to the leak of the working medium can be improved. As a result, a piezoelectric pump that can be used for a long time in a closed system operating at a pressure lower or higher than atmospheric pressure is provided. In addition, by providing a non-metal internal part between the metal casing and the piezoelectric element to separate the casing from the piezoelectric element, it is possible to suppress the transfer of welding heat to the piezoelectric element.

Here, the first and second internal parts are made of resin, so that the first and second internal parts respectively define the outer periphery of the first and second internal spaces, and sandwich the piezoelectric elements between the first and second internal parts. It is preferable to hold the piezoelectric element.

The piezoelectric pump can be manufactured at low cost by using a resin which is easy to be molded and by holding the piezoelectric element in a simple structure.

The piezoelectric pump, in one aspect, is formed on the first internal part and on the inlet part through which the working medium passes from the suction pipe outside the casing to the first internal space as the working space. An outlet portion through which the working medium from the first inner space to the discharge pipe outside the casing passes, a first check valve provided between the inlet portion and the first inner space, and a first portion provided between the outlet portion and the first inner space; A second check valve, a plurality of O-rings respectively sealing a gap between the first and second internal spaces and the piezoelectric element, and a gap between the inlet and the outlet and the casing, respectively. Here, it is preferable to provide the 1st and 2nd check valve installation part in which the 1st and 2nd check valves are respectively provided in the 1st internal component, and the some groove part in which the some O-ring is provided, respectively.

In this structure, by providing the recessed part and the groove | channel in the internal component which consists of resin, the installation stand or groove | channel in which a check valve and an O-ring are provided can be formed easily.

Here, it is preferable to further include a communication portion for communicating the second internal space as the back pressure space and the inlet portion or the outlet portion, and the communication portion is constituted by holes or grooves formed in the first and second internal parts.

By forming the communicating portion, the pressure between the working space (first inner space) and the back pressure space (second inner space) can be made approximately equal. In addition, by providing grooves and holes in the internal parts made of resin, it is possible to form a communication portion simply without forming a communication tube outside the casing. As a result, a compact piezoelectric pump for efficiently circulating the fluid is formed at low cost.

Moreover, it is preferable that the said communication part communicates with the junction site | part of the some metal member in a casing. Thereby, a communication part can be used as a leak check hole of a casing.

The piezoelectric pump may, in another aspect, be formed on a first inner part and pass through a first inlet through which the working medium passes from a first suction pipe outside the casing towards the first inner space as the working space; A second inlet formed in the first inlet and passing through the working medium from the second suction pipe outside the casing to the second inner space as the working space, and a first discharge formed on the first inner part and external to the casing from the first inner space; A first outlet through which the working medium towards the pipe passes, a second outlet through which the working medium is formed on the second internal component and from the second internal space toward the second discharge pipe outside the casing; First and second check valves provided between the second inlet and the first and second internal spaces, respectively, and a third installed between the first and second outlets and the first and second internal spaces, respectively. A plurality of O-rings respectively sealing a fourth check valve, a gap between the first and second internal spaces and the piezoelectric element, and a gap between the first and second inlet parts and the first and second outlet parts and the casing, respectively. It is further provided. Here, it is preferable to provide the 1st-4th check valve installation part in which the 1st-4th check valve is respectively provided in the 1st and 2nd internal parts, and the some groove part in which the some O-ring is provided, respectively.

In this configuration, both sides of the piezoelectric element can be used as the working space. Moreover, by providing the recessed part and the groove | channel in the internal component which consists of resin, the installation stand or groove | channel in which a check valve and an O-ring are provided can be formed easily. As a result, a piezoelectric pump for efficiently circulating the fluid is provided at a low cost.

It is preferable to provide the communication hole which communicates the joining site | part of a 1st or 2nd inlet part or a 1st or 2nd outlet part and a metal member.

This communication hole can be used as a leak check hole of the casing.

The piezoelectric pump is, in another aspect, formed on a first inner part and on a first inlet through which a working medium passes from a suction pipe outside the casing to a first inner space as an operating space, and on a second inner part. A second inlet portion formed and through which the working medium passes from the first inlet portion to the second inner space and through which the working medium formed on the first inner component and from the first inner space toward the discharge pipe outside the casing passes; A first outlet, a second outlet formed on the second internal part and through which the working medium passes from the second internal space toward the first outlet, and a hole or a groove formed in the first and second internal parts; A first communication portion communicating the first and second inlet portions, a second communication portion configured by holes or grooves formed in the first and second internal parts and communicating the first and second outlet portions; First and second check valves provided between the second inlet and the first and second internal spaces, respectively, and third and second provided between the first and second outlets and the first and second internal spaces, respectively. Four check valves, a plurality of O-rings respectively sealing the gap between the first and second internal spaces and the piezoelectric element, and the gap between the first and second inlet and the first and second outlet and the casing, respectively. Equipped. Here, it is preferable to provide the 1st-4th check valve installation part in which the 1st-4th check valve is respectively provided in the 1st and 2nd internal parts, and the some groove part in which the some O-ring is provided, respectively.

In this configuration, both sides of the piezoelectric element can be used as the working space. In addition, the first and second communication portions can be formed without providing a communication tube outside the casing. Moreover, by providing the recessed part and the groove | channel in the internal component which consists of resin, the installation stand or groove | channel in which the check valve and O-ring are provided can be formed easily. As a result, a compact piezoelectric pump for efficiently circulating the fluid is provided at low cost.

Here, one of the first and second communication portions may be in communication with the joining portion of the metal member in the casing. Thereby, a communication part can be used as a leak check hole of a casing.

Moreover, you may further provide the other O-ring which seals a 1st communication part or a 2nd communication part in the joining surface of a 1st internal part and a 2nd internal part. Thereby, the sealing property of the 1st and 2nd communication part used as the path | route of a working medium can be ensured.

Moreover, the some metal member which comprises a casing may have a flange part, respectively, and you may form the casing by welding the front-end | tip parts of a flange part. As a result, the welded portion and the piezoelectric element can be further separated. Therefore, the effect of suppressing heat input to the piezoelectric element can be further enhanced.

In the Stirling refrigerator according to the present invention, the above-described piezoelectric pump is provided in the working medium circulation circuit on the high temperature side.

According to the present invention, there is provided a piezoelectric pump in which slow leakage does not occur even if it is used continuously for a long time in a closed system of negative pressure and positive pressure.

1 is an example of a piping system diagram of a sterling cooler.

2 is a cross-sectional view of a piezoelectric pump according to a first embodiment of the present invention.

3 is a sectional view of a piezoelectric pump according to a second embodiment of the present invention.

4 is a sectional view of a piezoelectric pump according to a third embodiment of the present invention.

5 is an example of the side sectional view which shows the Stirling refrigerator in a Stirring refrigerator.

6 is a sectional view of a conventional piezoelectric pump.

[Description of the code]

1: Stirring Cooler

2: heat dissipation unit

2A to 2F: pipe (high temperature side circuit)

3: endothermic part

3A, 3B: Pipe (low temperature side circuit)

4: Stirring freezer

5: high temperature side evaporator

6: circulation pump

7: high temperature side condenser

8: fan

9: anti-kicking pipe

10: low temperature side condenser

11: low temperature side evaporator

12: fan

13: cylinder

14: piston

15: Displacer

16: player

17: working space

17A: Compression Space

17B: Expansion Space

18, 19: heat exchanger

18A: Tube

20: inner yoke

21: movable magnet

22: outer yoke

23: linear motor

24: piston spring

25: Displacer Spring

26: Displacer Load

27: back pressure space

28: leaf spring

29: balance mass

30, 32: casing

33A, 33B: Internal Parts

34, 34A, 34B: working space

35: back pressure space

36 piezoelectric element

37, 37A, 37B: inlet

38, 38A, 38B: outlet

39, 39A, 39B, 40, 40A, 40B: check valve

41, 41A, 41B: inlet pipe

42, 42A, 42B: outlet pipe

43: O ring

44: communication unit

44A: Leak Check Hole

44B: inlet communication section

44C: outlet communication section

45: power supply terminal

46: flange

EMBODIMENT OF THE INVENTION Below, embodiment of the piezoelectric pump and the Stirling refrigerator based on this invention is described using FIGS.

In addition, in this specification, a "freezer" is a concept including the whole "freezer", "freezer", and "freezer refrigerator".

In addition, in this specification, although the sterling refrigerator as a sterling engine mounting apparatus provided with the sterling refrigerator is demonstrated, the sterling engine mounting apparatus in which the piezoelectric pump which concerns on this invention is provided is not limited to a sterling refrigerator. The Stirling engine is also used as a generator, for example.

(Description of the Stirring Cooler)

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an example of a piping system diagram of a sterling cooler in which piezoelectric pumps according to the first to third embodiments of the present invention described later are provided in a working medium circulation circuit on a high temperature side.

As shown in Fig. 1, the Stirling refrigerator 1 has a Stirling refrigerator 4 (sterling engine) having a heat dissipation unit 2 and a heat absorbing unit 3, and a high temperature side evaporator 5 provided at the heat dissipation unit 2. ), A first high temperature side circulation circuit (first circulation circuit) including a high temperature side condenser 7 and pipes 2A, 2B, a high temperature side evaporator 5, a circulation pump 6, and a foot path Second high temperature side circulation circuit (second circulation circuit) including the prevention pipe 9 and the pipes 2C, 2D, 2E, and 2F, the low temperature side condenser 10 and the low temperature side evaporator provided in the heat absorbing section 3. And a low temperature side circuit including the pipes 3A and 3B. The first high temperature side circulation circuit cools the heat dissipation unit 2 of the Stirling Refrigerator 4, and the second high temperature side circulation circuit supplies heat to the kick prevention pipe 9. In addition, the low temperature side circulation circuit performs heat exchange between the air in the refrigerator and the heat absorbing portion 3 of the Stirling refrigerator 4.

In the first and second high temperature side circulation circuits, water (H 2 O) or the like is enclosed as a refrigerant. The refrigerant evaporated in the high temperature side evaporator 5 reaches the high temperature side condenser 7 through a pipe 2A (high temperature side conduit) (dashed arrow in Fig. 1). In the high temperature side condenser 7, heat exchange with outside air is performed, and a refrigerant | coolant condenses. In order to promote this heat exchange, the fan 8 which generate | occur | produces an airflow is provided in the vicinity of the high temperature side condenser 7. As shown in FIG. The condensed refrigerant is returned to the high temperature side evaporator 5 through the pipe 2B (high temperature side return tube). In the first high temperature side circulation circuit, the high temperature side condenser 7 is more than the high temperature side evaporator 5 so that heat generated in the heat dissipation unit 2 can be transferred using natural circulation by evaporation and condensation of the refrigerant. It is arranged above. Moreover, in order to adjust the boiling point of a refrigerant | coolant, the pressure in a circulation circuit system is adjusted (reduced pressure almost to vacuum).

On the other hand, a pipe 2C is connected to the lower portion of the high temperature side evaporator 5. The liquid refrigerant flows into the pipe 2C from the high temperature side evaporator 5. The refrigerant flowing into the pipe 2C reaches the circulation pump 6 provided below the Stirling Refrigerator 4 via the pipe 2D. The refrigerant discharged from the circulation pump 6 is transferred to the kick prevention pipe 9 through the pipe 2E. Here, the refrigerant flowing inside the kick prevention pipe 9 is kept at a relatively high temperature by heat applied from the heat dissipation unit 2 of the Stirling refrigerator 4. Therefore, kicking in the door part etc. can be suppressed by arrange | positioning the kick prevention pipe 9 in the front surface of a refrigerator. The refrigerant flowing in the kick prevention pipe 9 is returned to the high temperature side evaporator 5 through the pipe 2F. Thus, in the 2nd high temperature side circulation circuit, the forced circulation by the circulation pump 6 is performed.

In the low temperature side circuit, carbon dioxide, a hydrocarbon, etc. are enclosed as a refrigerant. The refrigerant condensed in the low temperature side condenser 10 reaches the low temperature side evaporator 11 through a pipe 3A (low temperature side conduit). In the low temperature side evaporator 11, heat exchange is performed by evaporation of the refrigerant. In order to promote this heat exchange, the fan 12 which generate | occur | produces an airflow is provided in the vicinity of the low temperature side evaporator 11. As shown in FIG. The refrigerant gasified after the heat exchange is returned to the low temperature side condenser 10 through the pipe 3B (low temperature side return tube). In the low temperature side circulation circuit, the low temperature side evaporator 11 is lower than the low temperature side condenser 10 so that the cold heat generated in the heat absorbing section 3 can be transmitted by using the natural circulation by the evaporation and condensation of the refrigerant in this way. It is arranged. In addition, in order to adjust the boiling point of the refrigerant, the pressure in the circulation circuit system is adjusted (reduced to approximately vacuum).

When the Stirling refrigerator 4 is operated, heat generated in the heat dissipating unit 2 of the refrigerator 4 is exchanged with air through the high temperature side condenser 7. On the other hand, the cold heat generated in the endothermic portion 3 of the Stirling refrigerator (4) is heat-exchanged with the air in the cooler through the low temperature side evaporator (11). The warmed air stream from the inside of the freezer is transferred to the vicinity of the low temperature side evaporator 11 and cooled repeatedly.

(1st embodiment)

Fig. 2 is a sectional view showing the piezoelectric pump according to the first embodiment.

As shown in Fig. 2, the piezoelectric pump 6 according to the present embodiment has a casing 32 formed by welding a plurality of metal members and a space in the casing 32 with an operating space 34 (first). A piezoelectric element 36 partitioning the inner space) and the back pressure space 35 (second inner space), and a nonmetallic metal disposed between the casing 32 and the piezoelectric element 36 to hold the piezoelectric element 36. Internal parts 33A and 33B (first and second internal parts).

The internal parts 33A and 33B are made of resin which is easy to be processed and molded. The internal part 33A defines the outer circumference of the working space 34 (pump chamber), and the internal part 33B defines the outer circumference of the back pressure space 35. By opposing the internal components 33A and 33B, a recess is formed between the internal components 33A and 33B, and the piezoelectric element 36 is accommodated and held in the recess. That is, the internal components 33A and 33B hold the piezoelectric element 36 by sandwiching the piezoelectric element 36.

In the example of FIG. 2, the inlet portion 37 formed on the inner component 33A and through which the working medium passes from the inlet pipe 41 (suction pipe) outside the casing 32 to the working space 34 is passed. An inlet portion 37 and an outlet portion 38 formed on the internal component 33A and through which the working medium passes from the working space 34 toward the outlet pipe 42 (discharge pipe) outside the casing 32; And a check valve 39 (first check valve) provided between the working space 34 and the check valve 40 (second check valve) provided between the outlet portion 38 and the working space 34. A plurality of O respectively sealing a gap between the working space 34 and the back pressure space 35 and the piezoelectric element 36 and a gap between the inlet portion 37 and the outlet portion 38 and the inner surface of the casing 32. The ring 43 is provided. Here, the mounting table (the 1st and 2nd check valve installation part) in which the check valves 39 and 40 are respectively installed, and the groove part to which each O-ring 43 is attached are previously processed into the internal parts 33A and 33B. It is installed by performing.

The piezoelectric pump 6 has a communicating portion 44 which communicates the back pressure space 35 with the inlet portion 37. The communication part 44 is comprised by the hole or the groove formed in the internal parts 33A and 33B. The communication part 44 reaches on the inner surface of the casing 32, and communicates with the welding site | part of several metal member. Instead of the communicating section 44, a communicating section communicating the back pressure space 35 and the outlet section 38 may be provided.

When the piezoelectric pump 6 is actually operated, an electric signal is applied to the piezoelectric element 36 via the power supply terminal 45, and the piezoelectric element 36 is amplitude-moved in the left and right directions in FIG.

In the above configuration, by joining a plurality of members constituting the casing 32 by welding, the durability to the leak of the working medium can be improved. As a result, the piezoelectric pump 6 which can be used for a long time in the closed system of a negative pressure and a positive pressure state is provided. Moreover, when the internal parts 33A and 33B made of resin are provided between the metal casing 32 and the piezoelectric element 36, the casing 32 and the piezoelectric element 36 are spaced apart to weld the metal member. Transmission of the welding heat to the piezoelectric element 36 can be suppressed. Therefore, the operating efficiency of the piezoelectric element 36 is improved, and consequently, the circulation efficiency of the working medium is improved.

As the internal parts 33A and 33B, the piezoelectric pump 6 can be carried out at low cost by using a resin part which is easy to be molded and by holding the piezoelectric element 36 in a simple structure as described above. I can make it.

In addition, the mounting table and the groove in which the check valves 39 and 40 and the plurality of O-rings 43 are respectively provided can be easily formed by providing recesses and grooves in the resin internal parts 33A and 33B.

In addition, the communicating portion 44 is formed, whereby the pressure between the working space 34 (first internal space) and the back pressure space 35 (second internal space) can be maintained substantially the same. As a result, the circulation efficiency of a working medium improves in a negative pressure and a positive pressure state. Here, the communication part 44 can be easily formed without providing a communication pipe outside the casing by providing grooves and holes in the resin internal parts 33A and 33B. As a result, the compact structure of the piezoelectric pump 6 is realized at low cost. In addition, by communicating the communication part 44 with the welding site of the some metal member, the communication part 44 can be used as a leak check hole (communication hole) of a casing.

The metal member which comprises the casing 32 has the flange part 46, respectively, and the casing 32 is formed by welding the front-end | tip parts of the flange part 46. As shown in FIG. By providing the flange portion 46, the welded portion and the piezoelectric element 36 can be further separated. Therefore, the effect of suppressing heat input to the piezoelectric element 36 can be further enhanced.

(2nd embodiment)

3 is a cross-sectional view showing a piezoelectric pump according to a second embodiment.

The piezoelectric pump 6 which concerns on this embodiment is a modification of the piezoelectric pump 6 which concerns on 1st Embodiment, and uses both sides of the piezoelectric element 36 as a pump room (operating space 34A, 34B), It is characterized by the above-mentioned. do.

The piezoelectric pump 6 is formed on the internal part 33A (first internal part) as shown in FIG. 3 and is operated from the inlet pipe 41A (first suction pipe) outside the casing 32. The inlet portion 37A (first inlet) through which the working medium toward 34A (the first inner space) passes, and formed on the inner component 33B (the second inner component) and outside the casing 32. On the inlet portion 37B (second inlet) through which the working medium from the inlet pipe 41B (second suction pipe) is directed toward the working space 34B (second inner space), and on the internal component 33A. An outlet portion 38A (first outlet portion) formed therein and through which the working medium passes from the operating space 34A toward the outlet pipe 42A (first discharge pipe) outside the casing 32; and the internal component 33B. An outlet portion 38B (second outlet portion) formed thereon and through which the working medium passes from the operating space 34B toward the outlet pipe 42B (second discharge pipe) outside the casing 32; Check valves 39A and 39B (first and second check valves) provided between the sections 37A and 37B and the working spaces 34A and 34B, respectively, the outlet portions 38A and 38B and the working space 34A, Check valves 40A and 40B (third and fourth check valves) respectively provided between 34B), a gap between the working spaces 34A and 34B and the piezoelectric element 36 and inlets 37A and 37B, and A plurality of O-rings 43 are respectively provided to seal gaps between the outlet portions 38A and 38B and the inner surface of the casing 32. Here, the mounting table (first to fourth check valve mounting portions) on which the check valves 39A, 39B, 40A, and 40B are respectively installed, and the groove portion on which the respective O-rings 43 are installed, are internal parts 33A and 33B. It is installed by performing a process in advance.

The piezoelectric pump 6 reaches the internal parts 33A and 33B from the inlets 37A and 37B on the inner surface of the casing 32 and communicates with the leak check hole 44A in communication with the welded portions of the plurality of metal members. (Communication holes). The leak check hole 44A may be provided only on one side of the internal parts 33A and 33B, and reaches on the inner surface of the casing 32 from the outlet parts 38A and 38B instead of the leak check hole 44A. The leak check hole which communicates with the welding site | part of a some metal member may be provided.

Also with the said structure, similarly to 1st Embodiment, the piezoelectric pump 6 with high circulation efficiency which can be used for a long time in the closed system of a negative pressure and a positive pressure state is provided at low cost.

In addition, by leaking the leak check hole 44A with the welded portions of the plurality of metal members, the leak check of the casing can be performed.

In addition, in this embodiment, detailed description is not repeated about the same matter as 1st Embodiment mentioned above.

(Third embodiment)

4 is a sectional view showing a piezoelectric pump according to a third embodiment.

The piezoelectric pump 6 which concerns on this embodiment is a modification of the piezoelectric pump 6 which concerns on 1st Embodiment, and uses both sides of the piezoelectric element 36 as a pump room (operating space 34A, 34B), It is characterized by the above-mentioned. do.

The piezoelectric pump 6 is formed on the internal part 33A (first internal part) and shown in Fig. 4, and the working space 34A is formed from the inlet pipe 41 (suction pipe) outside the casing 32. The inlet portion 37A (first inlet) through which the working medium is directed toward (first inner space), and formed on the inner component 33B (second inner component) and from the inlet portion 37A An inlet portion 37B (second inlet portion) through which the working medium toward 34B (second inner space) passes, and formed on the inner component 33A and outside the casing 32 from the operating space 34A. The outlet portion 38A (first outlet portion) through which the working medium directed toward the outlet pipe 42 (discharge pipe) passes, and formed on the internal component 33B and from the operating space 34B to the outlet portion 38A. An inlet portion 38B (second outlet portion) through which the working medium toward the light passes, and an inlet portion formed by holes or grooves formed in the internal components 33A and 33B and communicating the inlet portions 37A and 37B. Outlet communication part 44C (second communication part) which consists of communication part 44B (1st communication part) and the hole or the groove formed in internal parts 33A, 33B, and communicates outlet parts 38A, 38B. And check valves 39A and 39B (first and second check valves) provided between the inlets 37A and 37B and the working spaces 34A and 34B, respectively, the outlets 38A and 38B and the working space. Check valves 40A and 40B (third and fourth check valves) respectively provided between the 34A and 34B, and the gap and inlet portion 37A between the working spaces 34A and 34B and the piezoelectric element 36. A plurality of O-rings 43 are respectively provided to seal gaps between the 37B) and the outlet portions 38A, 38B and the inner surface of the casing 32. Here, the mounting table (first to fourth check valve mounting portions) on which the check valves 39A, 39B, 40A, and 40B are respectively installed, and the groove portion on which the respective O-rings 43 are installed, are internal parts 33A and 33B. It is installed by performing a process in advance.

Here, the inlet communication part 44B reaches on the inner surface of the casing 32, and communicates the welding site | part of several metal member. Thereby, the inlet communication part 44B can be used as a leak check hole. On the other hand, as shown in Fig. 4, the outlet communicating portion 44C is sealed by providing an O-ring (another O-ring) on the joining surfaces of the internal parts 33A and 33B, and the welded portions of the plurality of metal members are connected to each other. Does not communicate. In addition, the inlet communicating section 44B may be sealed, and the outlet communicating section 44C may communicate with the welding site. In this way, only one of the inlet communicating section 44B and the outlet communicating section 44C communicates with the welding site, and the other is sealed by an O-ring, so that the inlets 37A and 37B serving as a passage of the working medium and the outlet are provided. It is possible to avoid the portions 38A and 38B communicating with each other.

Also with the said structure, similarly to 1st Embodiment, the piezoelectric pump 6 with high circulation efficiency which can be used for a long time in the closed system of a negative pressure and a positive pressure state is provided at low cost.

In addition, the inlet communication section 44B and the outlet communication section 44C can be easily formed without providing a communication tube outside the casing by providing grooves or holes in the resin internal parts 33A and 33B. As a result, the compact structure of the piezoelectric pump 6 is realized.

In addition, in this embodiment, detailed description is not repeated about the same matter as 1st Embodiment mentioned above.

(Description of Stirring Freezer)

5, an example and the operation | movement of the structure of the sterling refrigerator 4 are demonstrated.

As shown in Fig. 5, the sterling refrigerator 4 of the present embodiment is a free piston type sterling engine, and has a casing 30, a cylinder 13 assembled to the casing 30, and a cylinder 13; The operating space 17 including the piston 14 and the displacer 15, the regenerator 16, the compression space 17A and the expansion space 17B, and the heat dissipation portion 2 And a heat absorbing portion 3, a linear motor 23 as a piston driving means, a piston spring 24, a displacer spring 25, a displacer rod 26, and a back pressure space 27. do.

In the example of FIG. 5, the outer housing (outer wall) of the sterling refrigerator 4 is not constituted by a single container, but has a casing 30 (vessel portion) located on the back pressure space 27 side, and an operating space 17 side. It consists mainly of the heat radiating part 2, the tube 18A, and the heat absorbing part 3 which are located in. The casing 30 defines a back pressure space 27. The casing 30 can be assembled with various components including the cylinder 13, the linear motor 23, the piston spring 24, and the displacer spring 25. Inside the outer housing, a working medium such as helium gas, hydrogen gas, or nitrogen gas is filled.

The cylinder 13 has a substantially cylindrical shape, and accommodates the piston 14 and the displacer 15 as a free piston in a reciprocating manner therein. In the cylinder 13, the piston 14 and the displacer 15 are spaced coaxially and spaced apart by the piston 14 and the displacer 15 an operating space 17 in the cylinder 13. It is divided into the compression space 17A and the expansion space 17B. More specifically, the operating space 17 is a space located on the displacer 15 side rather than an end face on the displacer 15 side of the piston 14, and the piston 14 and the displacer 15 are located. A compression space 17A is formed therebetween, and an expansion space 17B is formed between the displacer 15 and the heat absorbing portion 3. The compression space 17A is mainly surrounded by the heat dissipation unit 2, and the expansion space 17B is mainly surrounded by the heat absorbing unit 3.

Between the compression space 17A and the expansion space 17B, a regenerator 16 is formed in which a film is wound while having a predetermined gap on the inner circumferential surface of the tube 18A. 17A and the expansion space 17B communicate with each other. Thereby, the closed circuit is comprised in the stirring refrigerator 4. By the operation medium enclosed in this closed circuit flowing in accordance with the operation | movement of the piston 14 and the displacer 15, the reverse stirring cycle mentioned later is implement | achieved.

The linear motor 23 is disposed in the back pressure space 27 located outside the cylinder 13. The linear motor 23 has an inner yoke 20, a movable magnet portion 21, and an outer yoke 22. The linear motor 23 allows the piston 14 to move in the axial direction of the cylinder 13. Driven.

One end of the piston 14 is connected to a piston spring 24 made of a leaf spring or the like. The upper piston spring 24 functions as elastic force imparting means for imparting elastic force to the piston 14. By applying an elastic force to the piston spring 24, it becomes possible to reciprocate the piston 14 more stably in the cylinder 13 more stably. One end of the displacer 15 is connected to the displacer spring 25 via the displacer rod 26. The displacer rod 26 is disposed through the piston 14, and the displacer spring 25 is composed of a leaf spring or the like. The peripheral part of the said displacer spring 25 and the peripheral part of the piston spring 24 support which extends from the linear motor 23 to the back pressure space 27 side of the piston 14 (henceforth, it may be called back). Supported by the member.

On the side opposite to the displacer 15 with respect to the piston 14, a back pressure space 27 surrounded by the casing 30 is disposed. The back pressure space 27 is located on the outer circumferential region located around the piston 14 in the casing 30 and on the piston spring 24 side (rear side) than the piston 14 in the casing 30. A posterior region. There is also a working medium in this back pressure space 27.

On the inner circumferential surface of the heat dissipation unit 2 and the heat absorbing unit 3, a heat exchanger 18 and a heat exchanger 19 are provided. The heat exchangers 18 and 19 heat-exchange between the compression space 17A, the expansion space 17B, the heat dissipation part 2, and the heat absorbing part 3, respectively.

On the rear side of the casing 30, a balance mass 29 is provided via the leaf spring 28. The balance mass 29 is a mass member that absorbs the vibration of the casing 30 generated by the vibration of the piston 14 and the displacer 15. Specifically, when vibration occurs in the casing 30 due to the vibration of the piston 14 or the displacer 15, the balance mass 29 vibrates so as to follow the vibration of the casing 30, thereby causing the stirling freezer. The vibration of (4) is reduced.

Next, operation | movement of this Stirling refrigerator 4 is demonstrated.

First, the linear motor 23 is operated to drive the piston 14. The piston 14 driven by the linear motor 23 approaches the displacer 15 to compress the working medium (working gas) in the compression space 17A.

As the piston 14 approaches the displacer 15, the temperature of the working medium in the compression space 17A increases, but heat generated in the compression space 17A is released to the outside by the heat dissipation portion 2. Therefore, the temperature of the working medium in the compression space 17A is kept approximately isothermal. That is, this process is corresponded to the isothermal compression process in a reversestering cycle.

After the piston 14 approaches the displacer 15, the displacer 15 moves to the heat absorbing portion 3 side. On the other hand, the working medium compressed in the compression space 17A by the piston 14 flows into the regenerator 16 and also flows into the expansion space 17B. At that time, the heat of the working medium is stored in the regenerator 16. That is, this process is corresponded to the isothermal cooling process of a reverse-stering cycle.

The high-pressure working medium introduced into the expansion space 17B expands as the displacer 15 moves to the piston 14 side (rear side). As the displacer 15 moves to the rear side in this manner, the center portion of the displacer spring 25 is also deformed to protrude toward the rear side.

As described above, when the working medium expands in the expansion space 17B, the temperature of the working medium in the expansion space 17B decreases, but external heat is transferred to the expansion space 17B by the heat absorbing portion 3. In the expansion space 17B is maintained approximately isothermal. In other words, this process corresponds to the isothermal expansion process of the reverse-stering cycle.

The displacer 15 then begins to move in a direction away from the piston 14. Thereby, the working medium in the expansion space 17B passes through the regenerator 16 and is returned to the compression space 17A side again. The heat stored in the regenerator 16 at that time is given to the working medium, so that the working medium is heated up. That is, this process is corresponded to the isothermal heating process of a reverse-stering cycle.

This series of processes (isothermal compression process-isothermal cooling process-isothermal expansion process-isothermal heating process) is repeated to form a reverse stiring cycle. As a result, the heat absorbing portion 3 gradually becomes a low temperature, and reaches an extremely low temperature (for example, about -50 ° C). On the other hand, the heat radiating part 2 becomes high temperature (for example, about 60 degreeC) gradually. As described above, the cold heat in the heat absorbing portion 3 is supplied into the refrigerator through the low temperature side circulation circuit, and the heat in the heat dissipating portion 2 is cooled through the first and second high temperature side circulation circuits. Is released out.

As mentioned above, although embodiment of this invention was described, combining the characteristic part of each embodiment mentioned above suitably is planned from the beginning. In addition, it should be thought that embodiment disclosed this time is an illustration and restrictive at no points. The scope of the invention is indicated by the claims, and it is intended to include any modification within the scope and meaning equivalent to the claims.

As described above, the present invention is applied to a piezoelectric pump and a stirling cooler.

Claims (9)

A casing 32 formed by joining a plurality of metal members; A piezoelectric element 36 which divides the space in the casing 32 into first and second internal spaces 34, 34A, 34B, 35; A piezoelectric pump provided between the casing (32) and the piezoelectric element (36) and having first and second internal parts (33A, 33B) made of non-metal holding the piezoelectric element (36). The method according to claim 1, wherein the first and second internal parts 33A, 33B are made of resin, The first and second internal parts 33A, 33B define the outer periphery of the first and second internal spaces 34, 35, respectively, A piezoelectric pump for holding the piezoelectric element (36) by sandwiching the piezoelectric element (36) between the first and second internal components (33A, 33B). The inlet according to claim 1, wherein an operating medium formed on the first internal part 33A and passing from the suction pipe 41 outside the casing 32 toward the first internal space 34 as the working space passes. Section 37, An outlet portion 38 formed on the first internal component 33A and through which a working medium passes from the first internal space 34 toward the discharge pipe 42 outside the casing 32; A first check valve 39 installed between the inlet portion 37 and the first internal space 34; A second check valve 40 installed between the outlet portion 38 and the first internal space 34; Sealing a gap between the first and second internal spaces 34 and 35 and the piezoelectric element 36 and a gap between the inlet portion 37 and the outlet portion 38 and the casing 32, respectively. It is further provided with a plurality of O-rings 43, The first and second check valve mounting portions, on which the first and second check valves 39 and 40 are installed, are respectively provided in the first internal part 33A, and the plurality of O-rings 43 are respectively provided. Piezoelectric pump provided with a plurality of grooves. 4. The communication apparatus as set forth in claim 3, further comprising a communication portion (44) for communicating the second internal space (35) as the back pressure space and the inlet portion (37) or the outlet portion (38), The communicating portion (44) is constituted by a hole or a groove formed in the first and second internal parts (33A, 33B). The piezoelectric pump according to claim 3, further comprising a communication hole (44) for communicating the joining portion between the inlet portion (37) or the outlet portion (38) and the metal member. 2. The working medium according to claim 1, which is formed on the first internal part 33A and passes from the first suction pipe 41A outside the casing 32 toward the first internal space 34A as the working space. The first inlet portion 37A, A second inlet formed on the second internal part 33B and through which the working medium passes from the second suction pipe 41B outside the casing 32 toward the second internal space 34B as the working space ( 37B), A first outlet portion 38A formed on the first internal component 33A and through which a working medium passes from the first internal space 34A toward the first discharge pipe 42A outside the casing 32; , A second outlet portion 38B formed on the second internal component 33B and through which a working medium passes from the second internal space 34B toward the second discharge pipe 42B outside the casing 32; , First and second check valves 39A and 39B installed between the first and second inlets 37A and 37B and the first and second internal spaces 34A and 34B, respectively; Third and fourth check valves 40A and 40B installed between the first and second outlet portions 38A and 38B and the first and second internal spaces 34A and 34B, respectively; A gap between the first and second internal spaces 34A and 34B and the piezoelectric element 36, the first and second inlets 37A and 37B, and the first and second outlets 38A, A plurality of O-rings 43 each sealing a gap between 38B) and the casing 32; First to fourth check valve mounting portions each of which the first to fourth check valves 39A, 39B, 40A, and 40B are provided to the first and second internal parts 33A and 33B, and the plurality of A piezoelectric pump provided with a plurality of grooves in which the O-rings 43 are respectively provided. The communication hole 44A of Claim 6 provided with the said 1st or 2nd inlet part 37A, 37B or the 1st or 2nd outlet part 38A, 38B, and the junction part of the said metal member. Piezoelectric pump. The working medium according to claim 1, wherein the working medium is formed on the first internal part 33A and passes from the suction pipe 41 outside the casing 32 toward the first internal space 34A as the working space. 1 inlet (37A), A second inlet portion 37B formed on the second internal component 33B and through which a working medium passes from the first inlet portion 37A toward the second internal space 34B; A first outlet portion 38A formed on the first internal component 33A and through which a working medium passes from the first internal space 34A toward the discharge pipe 42 outside the casing 32; A second outlet portion 38B formed on the second internal component 33B and through which a working medium passes from the second internal space 33B toward the first outlet portion 38A; A first communication portion 44B constituted by holes or grooves formed in the first and second internal parts 33A and 33B, and for communicating the first and second inlet portions 37A and 37B; A second communication portion 44C constituted by holes or grooves formed in the first and second internal components 33A and 33B, and communicating the first and second outlet portions 38A and 38B; First and second check valves 39A and 39B installed between the first and second inlets 37A and 37B and the first and second internal spaces 34A and 34B, respectively; Third and fourth check valves 40A and 40B installed between the first and second outlet portions 38A and 38B and the first and second internal spaces 34A and 34B, respectively; A gap between the first and second internal spaces 34A and 34B and the piezoelectric element 36, the first and second inlets 37A and 37B, and the first and second outlets 38A, A plurality of O-rings 43 each sealing a gap between 38B) and the casing 32; First to fourth check valve mounting portions each of which the first to fourth check valves 39A, 39B, 40A, and 40B are provided to the first and second internal parts 33A and 33B, and the plurality of A piezoelectric pump provided with a plurality of grooves in which the O-rings 43 are respectively provided. A Stirling refrigerator in which the piezoelectric pump (6) according to claim 1 is provided in a working medium circulation circuit on the high temperature side.

Images