CN114413504A - Double-end opposite refrigerating structure - Google Patents

Abstract

The invention discloses a double-end opposite refrigeration structure, which comprises a shell, a power structure and an expansion piston structure, wherein the power structure and the expansion piston structure are arranged in the shell; the shell comprises a main shell and a cold head shell, the connecting end of the main shell and the cold head shell is a compression cavity, the power structure is arranged in the main shell, the expansion piston structure is arranged in the cold head shell, and the power structure comprises a hard shaft rod body, an inner cylinder body, an outer cylinder body and a coil assembly which are arranged from inside to outside; the upper side and the lower side of the shaft rod body are connected with a piston head; the outer cylinder body is a magnetic outer cylinder body and is of an open structure, the outer cylinder body is sleeved on the outer side of the inner cylinder body, the piston head is arranged in the compression cavity in a contact sealing mode, and the reciprocating motion of the power structure drives the expansion piston structure to reciprocate through the change of pressure difference to refrigerate. The invention adopts an independent linear driving mode and double-head refrigeration, ensures and even improves the refrigeration efficiency, and simultaneously reduces the processing difficulty by adopting a free piston mode in compression.

Description

Double-end opposite refrigerating structure

Technical Field

The invention relates to the field of refrigeration machines, in particular to a double-head opposite refrigeration structure.

Background

The traditional circulation theory is different, the circulation theory adopted by the sound energy compressor is a more efficient thermodynamic theory, and with the continuous development of new technology, the sound energy compressor is also paid more and more attention by technicians.

For example, CN201920751878.7 discloses a thermoacoustic refrigerator, which works with a power piston and an expansion piston coaxially arranged to achieve the effect of refrigerating at the end of the expansion piston.

However, this process requires a particularly high machining precision of the lower coaxial motion rod of the expansion piston, which requires a large production process, is costly to produce, and is relatively complex.

Therefore, a novel refrigeration structure is needed to be provided, so that the refrigeration effect is ensured, and meanwhile, the production cost is reduced.

Disclosure of Invention

The invention aims to solve the problems and provides a double-head opposite refrigeration structure which adopts an independent linear driving mode and double-head refrigeration to ensure or even improve the refrigeration efficiency, and simultaneously adopts a free piston mode in compression to reduce the processing difficulty.

And the power end integrates the rotor structure, so that the volume of the driving structure is reduced, and the whole power structure is characterized in that the central shaft is positioned by adopting plate springs at two sides, the movement track is fixed, the friction is effectively avoided, and the motor efficiency is improved, so that the refrigerating device is high in refrigerating efficiency, small in volume and low in production cost.

In order to achieve the purpose, the invention adopts the technical scheme that: the expansion piston type hydraulic pump comprises a shell, and also comprises a power structure and an expansion piston structure which are arranged in the shell; the shell comprises a main shell and a cold head shell, the connecting end of the main shell and the cold head shell is a compression cavity, the power structure is arranged in the main shell, and the expansion piston structure is arranged in the cold head shell; the power structure comprises a hard shaft rod body, an inner cylinder body, an outer cylinder body and a coil assembly which are arranged from inside to outside; the upper side and the lower side of the shaft rod body are both connecting ends, and the connecting ends are used for connecting the piston head; the upper side of the shaft lever body is provided with at least two first locking rings, the lower side of the shaft lever body is provided with at least two second locking rings, and the first locking rings and the second locking rings are used for limiting the elastic sheet; the shaft lever body is also fixedly provided with the outer cylinder body between the first locking ring and the second locking ring, and the outer cylinder body is a magnetic outer cylinder body and is of an open structure and is sleeved outside the inner cylinder body; the piston head is in contact sealing in the compression cavity, the inner cylinder body is fixed on the first step, the elastic sheet at the lower side is fixed on the second step, and the elastic sheet at the upper side is fixed on the inner cylinder body; the expansion piston structure comprises an expansion fixing seat fixed by the main shell and the cold head shell, the bottom side of the expansion fixing seat is hollow, at least two expansion elastic sheets are fixed on a central shaft, the circumference of each expansion elastic sheet is fixed with the expansion piston, and the expansion piston is in an air suspension state in the cold head shell.

Further, the outer cylinder body comprises a connecting end and a magnetic end, the connecting end and the shaft rod body are locked and fixed through bolts, the magnetic end is provided with a permanent magnet on the cylinder body, and the inner cylinder body is of a T-shaped structure and comprises a fixed end and a first connecting end.

Furthermore, the first connecting end is a soft magnetic end or is provided with a silicon steel sheet or a silicon steel sheet.

Further, the coil assembly comprises a coil and a yoke structure arranged on the outer side of the coil, wherein the yoke structure is soft magnetic yoke iron or silicon steel sheet yoke iron.

Furthermore, the number of the first locking rings is three on the upper side, and the number of the second locking rings is two on the lower side; the first locking ring and the second locking ring are both expansion sleeves, an internal thread structure is arranged inside the connecting end, a connecting through hole is formed in the center shaft of the piston head, the top of the connecting through hole is a limiting end, and a locking bolt penetrates through the limiting end to be locked with the internal thread structure.

Furthermore, the elastic sheet and the expansion elastic sheet are in a circular plate spring structure, at least four fixing through holes are arranged on the upper circumference of the elastic sheet and are equally divided, and a through hole is formed in the center of the elastic sheet and the expansion elastic sheet.

Furthermore, a fixing platform is arranged on the outer side of the first step, the main shell comprises an upper shell and a lower shell, the lower shell is fixed on the fixing platform when the coated main body is limited by the first step, a shell fixing bolt penetrates through the upper shell and is fixedly locked with the coated main body, a sealing ring is arranged between the coated main body and the first step, and radiating fins are arranged on the outer sides of the upper shell and the lower shell.

Further, the main shell comprises a central cavity shell, and a heat dissipation fin fixed on the central cavity shell and the upper shell.

Furthermore, the outer side end of the cold head shell is provided with an expansion piston heat dissipation end, and the outer side of the cold head shell is provided with a red copper heat dissipation part.

Further, a cold guiding head is arranged at the end part of the cold head shell.

In summary, the invention has the following advantages:

the invention provides a double-head opposite refrigeration structure, which adopts an independent linear driving mode and double-head compression refrigeration to ensure and even improve the refrigeration efficiency, and simultaneously adopts a free piston mode for compression to reduce the processing difficulty.

And the power end integrates the rotor structure, so that the volume of the driving structure is reduced, and the whole power structure is characterized in that the central shaft is positioned by adopting plate springs at two sides, the movement track is fixed, the friction is effectively avoided, and the motor efficiency is improved, so that the refrigerating device is high in refrigerating efficiency, small in volume and low in production cost.

The driving part of the invention adopts a magnetic driving mode, the coil is fixed, the motion trail of the central shaft lever is constant, the plate springs on the two sides can be effectively limited when being compressed transversely, reciprocating power is provided, reciprocating double-head compression can be realized, the compression efficiency is high, and the working efficiency of the refrigerator is high.

The invention provides an upper and lower split type shell structure which is convenient to assemble and disassemble, assembling steps are reserved on the upper and lower shells, the installation of an inner side power structure is convenient, and meanwhile, the production is simpler and more convenient due to the whole design of the inner side compression chamber and the power part.

Of course, in the optimization mode of the main shell, two implementation modes are provided, and both have simple and convenient assembly effects.

Drawings

FIG. 1 is a schematic view of a central shaft configuration;

FIG. 2 is an enlarged schematic view of section A;

FIG. 3 is a schematic diagram of a power configuration;

FIG. 4 is a schematic view of the inner cylinder structure;

FIG. 5 is a schematic view of the structure of the outer cylinder;

FIG. 6 is a schematic diagram of a spring plate structure;

FIG. 7 is a schematic of the present invention;

FIG. 8 is a schematic sectional view of the main housing structure;

FIG. 9 is a cross-sectional view of the power structure of the present invention;

fig. 10 is a schematic cross-sectional view of the housing of the present invention.

Detailed Description

The invention is further described with reference to the following figures and examples:

example 1:

it should be noted that, in the present embodiment, the term "upper" and "lower" are used in a broad sense rather than in a limited positional relationship, and in the description of the present embodiment, the term "upper" and "lower" are used in combination with the drawings to facilitate understanding of the technical solution.

A double-head opposite refrigeration structure is shown in figures 1-8 and comprises a shell, a power structure and an expansion piston structure, wherein the power structure and the expansion piston structure are arranged in the shell; the shell comprises a main shell body 1-100 and a cold head shell body 1-200, wherein the connecting end of the main shell body and the cold head shell body is a compression cavity 300, the power structure is arranged in the main shell body 1-100, and the expansion piston structure is arranged in the cold head shell body 1-200.

Specifically, referring to fig. 1-6, the power structure includes a hard shaft body 1, an inner cylinder 7, an outer cylinder 6 and a coil assembly 8 arranged from inside to outside.

The shaft rod body is preferably a metal shaft rod, more preferably a soft magnetic material, and has a better effect under the condition of dynamic magnetic driving, and of course, the rigidity of other materials can be satisfied.

The upper side and the lower side of the shaft lever body 1 are both connecting ends 2, and the connecting ends are used for connecting pistons.

Specifically, referring to fig. 2, the connecting end 2 is internally provided with an internal thread structure 21, and the piston head 3 is provided with a connecting through hole 31 on the central axis.

The top of the connecting through hole 31 is a limiting end 32, and a locking bolt 33 passes through the limiting end 32 and is locked with the internal thread structure 21, so that the piston head moves synchronously under the condition that the shaft rod body moves.

It should be noted that the connecting through hole 31 and the internal thread structure 21 are both located on the central axis of the respective structures, so that the central axis has a high degree of progress during movement, and friction is not easily generated.

The upper side of the shaft lever body 1 is provided with at least two first locking rings 4, the lower side of the shaft lever body is provided with at least two second locking rings 5, and an external cylinder body 6 is fixedly arranged between the first locking rings 4 and the second locking rings 5 of the shaft lever body 1.

Referring to the attached figure 1, the outer cylinder body 6 is a power source for the movement of a central shaft, the outer cylinder body 6 is a magnetic outer cylinder body and is of an open structure, the outer cylinder body is sleeved on the outer side of the inner cylinder body 7, the outer cylinder body and the inner cylinder body are coaxial but not in contact, and the outer cylinder body and the coil assembly act to generate movement through an ampere force principle.

In a specific fixing manner, the external cylinder 6 and the shaft body 1 are locked and fixed by bolts.

Of course, the connection by the expansion sleeve is also a fixing mode, and the details are not repeated herein.

With continued reference to the figures, the external cylinder 6 comprises a connecting end 61 and a magnetic end 62, in particular, the connecting end 6 is fastened to the shaft body 1 by bolts.

Further, the magnetic end 62 is provided with a permanent magnet 63 on the cylinder body, and the permanent magnet can be arranged outside the magnetic end and close to the coil, can be bonded in an adhesive manner and can be embedded into the coil, so that the overall design is compact, and the volume of the power structure is reduced.

With continued reference to fig. 1, the first locking ring 4 is provided with three on the upper side.

Further, the second locking ring 5 is provided with two on the lower side.

Further, the first locking ring 4 and the second locking ring 5 are both expansion sleeves.

The first locking ring and the second locking ring are arranged to fix the shaft body with the elastic sheet, the elastic sheet is preferably a plate spring, specifically, the elastic sheet 9 is a circular plate spring structure, at least four fixing through holes 91 are equally arranged on the upper circumference part, and a through hole 92 is arranged at the center position.

The axostylus axostyle body passes the perforating hole, and the upside is fixed by first lock ring 4, and is specific, and first upside is equipped with twice shell fragment 9.

The shell fragment downside is fixed by the second locking ring, is equipped with twice shell fragment, and moreover, two locking rings of downside, with the locking structure cooperation of outer cylinder body, fixed the shell fragment, can reduce cost.

The elastic sheets are in a fixed state relative to the whole compressor and are fixed with the shell of the compressor through the fixing through holes, and the elastic sheets arranged on the two sides position the central shaft on the two sides, so that the motion trail of the central shaft can only move on the central tracks of the two elastic sheets, and the motion precision of the central shaft is improved.

The following is further described with reference to the housing structure in terms of the specific connection manner of the elastic pieces.

In a specific arrangement of the driving structure, the inner cylinder 7 is a T-shaped structure and includes a fixed end 71 and a first connection end 72, and the coil assembly 8 includes a coil 81 and a yoke structure 82 disposed outside the coil.

Further, the first connecting end 72 is a soft magnetic end or a silicon steel sheet is disposed thereon, and the yoke structure 82 is a soft magnetic yoke or a silicon steel sheet yoke.

The selection of the specific material can effectively reduce the loss of the motor iron core and improve the structural efficiency of the dynamic force.

With continued reference to fig. 7-10, the main housing portion has two preferred embodiments in the design of the housing structure.

Providing a first embodiment, a fixing platform 102 is arranged outside the first step 101, the main housing 1-100 includes an upper housing 100 and a lower housing 200, the covering main body 202 of the lower housing 200 is fixed to the fixing platform 102 while being limited by the first step 201, a housing fixing bolt 600 penetrates through the upper housing 100 and is locked and fixed with the covering main body 202, a sealing ring is arranged between the covering main body 202 and the first step 201, and heat dissipation fins 700 are arranged outside both the upper housing 100 and the lower housing 200.

In this embodiment, both the upper and lower housing ends are compression chambers 300, which are connected to the coldhead housing.

In the present embodiment, the elastic sheet is mainly limited and fixed with the yoke structure when being fixed with the coil structure, and meanwhile, the elastic sheet is limited by the second step 201 on the inner side of the lower housing 200.

With reference to fig. 8 and 9, in the fixing manner of the upper housing and the lower housing, a fixing platform 102 is disposed outside the first step 101, the covering main body 202 of the lower housing 200 is fixed to the fixing platform 102 while being limited by the first step 201, and a sealing ring is disposed between the covering main body 202 and the first step 201.

In a specific fixing manner, the housing fixing bolt 600 passes through the upper case 100 and is locked and fixed with the covering body 202.

In the heat dissipation of the whole compressor, the outer sides of the upper shell 100 and the lower shell 200 are respectively provided with the heat dissipation fins 700, so that the compressor can be guaranteed to have a good heat dissipation effect.

Providing a second embodiment, said main housing 1-100 comprises a central cavity housing 1-300 and an upper housing 100 fixed to said central cavity housing 1-300, said central cavity housing 1-300 is provided with heat dissipation fins 700 at the outside, in this embodiment, the upper housing is provided at the upper side and the inside is provided with a first step for positioning the power structure.

The outer end of the upper housing of this embodiment is a compression chamber 300 for connection with a coldhead housing.

In the present embodiment, when the elastic piece is fixed to the coil structure, the elastic piece is mainly fixed to the yoke structure, and the elastic piece is limited by the first step on the lower side.

The compression chamber is used for compressing gas, namely the piston head 3 is in contact with and sealed in the compression chamber 300, in particular, the outer side of the compression chamber 300 is an expansion piston chamber in a cold head structure, and a valve structure can be arranged between the compression chamber and the expansion piston chamber.

The design of valve block structure can be more excellent control gas's compression.

In the structural arrangement of the shell, a first step 101 is convexly arranged on the inner side of the upper shell 100, and a second step 201 is arranged on the inner side of the lower shell 200.

The first step 101 is used for fixing the power structure of the compressor, specifically, an inner cylinder body of the compressor is fixed on the first step, and relative to an outer cylinder body of the power structure of the compressor, the inner cylinder body is located at a static end and connected with the first step, so that other components can be conveniently fixed.

Namely, the inner cylinder 7 is fixed on the first step 101, the lower spring plate 9 is fixed on the second step 201 or the lower first step, and the upper spring plate 9 is fixed on the inner cylinder 7.

Thereby the central axis pole of the fixed power structure of central point of shell fragment puts, so can form fixedly to the position of central axis pole, keeps the axis pole body 1 to move at the axis of whole structure all the time promptly, improves the reciprocal efficiency of whole compressor.

Because the upper shell and the lower shell are both circular shells, the first step and the second step are connected by equally-divided bolts, and the stability is better.

In the arrangement of the cold head housing and the expansion piston structure, referring to fig. 10, the expansion piston structure 1-1 includes an expansion fixing seat 1-2 fixed by the main housing 1-100 and the cold head housing 1-200, the bottom side of the expansion fixing seat 1-2 is hollowed, at least two expansion spring pieces 1-3 are fixed on a central shaft, the circumference of the expansion spring pieces is fixed with the expansion piston 1-4, and the expansion piston 1-4 is in an air suspension state in the cold head housing 1-200.

Specifically, the expansion spring plate is also a circular plate spring structure, and has at least four fixing through holes 91 equally divided at the upper circumference part and a through hole 92 at the center position.

To be further explained by combining the fixing mode of the expansion piston, the expansion piston 1-4 adopts a four-axis fixing mode, and the upper part and the lower part of the expansion piston are locked and fixed at the circumferential part by four fixing through holes of the expansion elastic sheet.

In the embodiment, the expansion elastic sheet is arranged up and down and is fixed on the central shaft of the expansion fixed seat 1-2 through the center of the locking ring, namely, the expansion piston can reciprocate in the cold head shell.

The expansion piston is in an air suspension state, and the mechanism of the air suspension state is described in detail in patent application No. CN201920751878.7, which will not be described herein.

With continued reference to fig. 10, the outer side end of the cold head housing 1-200 is provided with an expansion piston heat dissipation end 1-201, and the outer side is provided with a red copper heat dissipation part 1-202.

Further, the end part of the cold head shell 1-200 is provided with a cold guiding head 1-203.

Further explained by combining the working mechanism, the coil is electrified (a wiring through hole is reserved on the shell), and the outer cylinder body reciprocates under the action of the ampere force principle, so that the piston head reciprocates, and gas compression is realized in the compression cavity.

The expansion piston moves along with the movement of the piston head under the action of differential pressure, and the top of the cold head shell forms a low-temperature state and is led out by the cold head when the pressure is changed in an isobaric manner.

And a high-temperature state is formed at the red copper heat dissipation part and is dissipated by the heat dissipation end.

In conclusion, the scheme adopts an independent linear driving mode, double-end compression refrigeration is adopted, the refrigeration efficiency is guaranteed or even improved, and meanwhile, the mode of a free piston is adopted in compression, and the processing difficulty is reduced.

And the power end integrates the rotor structure, so that the volume of the driving structure is reduced, and the whole power structure is characterized in that the central shaft is positioned by adopting plate springs at two sides, the movement track is fixed, the friction is effectively avoided, and the motor efficiency is improved, so that the refrigerating device is high in refrigerating efficiency, small in volume and low in production cost.

The driving part of the invention adopts a magnetic driving mode, the coil is fixed, the motion trail of the central shaft lever is constant, the plate springs on the two sides can be effectively limited when being compressed transversely, reciprocating power is provided, reciprocating double-head compression can be realized, the compression efficiency is high, and the working efficiency of the refrigerator is high.

The invention provides an upper and lower split type shell structure which is convenient to assemble and disassemble, assembling steps are reserved on the upper and lower shells, the installation of an inner side power structure is convenient, and meanwhile, the production is simpler and more convenient due to the whole design of the inner side compression chamber and the power part.

Of course, in the optimization mode of the main shell, two implementation modes are provided, and both have simple and convenient assembly effects.

The above embodiments are merely illustrative of the technical concepts and features of the present invention, and the purpose of the embodiments is to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and not to limit the protection scope of the present invention. All equivalent changes and modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements.

The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

It will be understood that the embodiments described above are illustrative only and not restrictive, and that various obvious and equivalent modifications and substitutions for details described herein may be made by those skilled in the art without departing from the basic principles of the invention.

Claims (10)

1. The utility model provides a double-end confrontation refrigeration structure which characterized in that: the expansion piston type hydraulic pump comprises a shell, and also comprises a power structure and an expansion piston structure which are arranged in the shell; the shell comprises a main shell (1-100) and a cold head shell (1-200), the connection end of the two is a compression cavity (300), the power structure is arranged in the main shell (1-100), and the expansion piston structure is arranged in the cold head shell (1-200); the power structure comprises a hard shaft rod body (1), an inner cylinder body (7), an outer cylinder body (6) and a coil assembly (8) which are arranged from inside to outside; the upper side and the lower side of the shaft rod body (1) are both provided with connecting ends (2), and the connecting ends (2) are used for connecting the piston heads (3); the upper side of the shaft lever body (1) is provided with at least two first locking rings (4), the lower side of the shaft lever body is provided with at least two second locking rings (5), and the first locking rings (4) and the second locking rings (5) are used for limiting the elastic sheet (9); the shaft lever body (1) is also fixedly provided with the outer cylinder body (6) between the first locking ring (4) and the second locking ring (5), and the outer cylinder body (6) is a magnetic outer cylinder body and has an open structure and is sleeved outside the inner cylinder body (7); the piston head (3) is in contact sealing in the compression cavity (300), the inner cylinder body (7) is fixed on a first step (101) in the main shell body (1-100), the elastic sheet (9) on the lower side is fixed on a second step (201), and the elastic sheet (9) on the upper side is fixed on the inner cylinder body (7); the expansion piston structure (1-1) comprises an expansion fixing seat (1-2) fixed by the main shell body (1-100) and the cold head shell body (1-200), the bottom side of the expansion fixing seat (1-2) is hollow, at least two expansion elastic sheets (1-3) are fixed on a central shaft, the circumference of each expansion elastic sheet is fixed with an expansion piston (1-4), and the expansion pistons (1-4) are in an air suspension state in the cold head shell body (1-200).

2. A dual-head opposing refrigeration structure as recited in claim 1, wherein: the outer cylinder body (6) comprises a connecting end (61) and a magnetic end (62), the connecting end (61) and the shaft rod body (1) are locked and fixed through bolts, the magnetic end (62) is provided with a permanent magnet (63) on the cylinder body, and the inner cylinder body (7) is of a T-shaped structure and comprises a fixed end (71) and a first connecting end (72).

3. A dual-head opposing refrigeration structure as recited in claim 2, wherein: the first connecting end (72) is a soft magnetic end or a silicon steel sheet arranged on the soft magnetic end.

4. A dual-headed opposing refrigeration structure as claimed in claim 1 or 3, wherein: the coil assembly (8) comprises a coil (81) and a yoke structure (82) arranged on the outer side of the coil, wherein the yoke structure (82) is soft magnetic yoke iron or silicon steel sheet yoke iron.

5. A dual-head opposing refrigeration structure as recited in claim 1, wherein: the number of the first locking rings (4) is three, and the number of the second locking rings (5) is two; the locking device is characterized in that the first locking ring (4) and the second locking ring (5) are both expansion sleeves, an internal thread structure (21) is arranged inside the connecting end (2), a connecting through hole (31) is formed in the center shaft of the piston head (3), the top of the connecting through hole (31) is a limiting end (32), and a locking bolt (33) penetrates through the limiting end (32) to be locked with the internal thread structure (21).

6. A dual-head opposing refrigeration structure as recited in claim 1, wherein: the elastic sheet (9) and the expansion elastic sheet (1-3) are of circular plate spring structures, at least four fixing through holes (91) are arranged on the upper circumference of the elastic sheet in an equant mode, and a through hole (92) is formed in the center of the elastic sheet.

7. A dual-headed opposing refrigeration structure as claimed in claim 1 or 6, wherein: the outer side of the first step (101) is provided with a fixing platform (102), the main shell (1-100) comprises an upper shell (100) and a lower shell (200), a coating main body (202) of the lower shell (200) is fixed on the fixing platform (102) when the first step (201) is limited, a shell fixing bolt (600) penetrates through the upper shell (100) and the coating main body (202) to be locked and fixed, a sealing ring is arranged between the coating main body (202) and the first step (201), and the outer side of the upper shell (100) and the outer side of the lower shell (200) are provided with radiating fins (700).

8. A dual-headed opposing refrigeration structure as claimed in claim 1 or 6, wherein: the main shell (1-100) comprises a central cavity shell (1-300) and an upper shell (100) fixed on the central cavity shell (1-300), and heat dissipation fins are arranged on the outer side of the central cavity shell (1-300).

9. A dual-head opposing refrigeration structure as recited in claim 1, wherein: the outer side end of the cold head shell (1-200) is provided with an expansion piston heat dissipation end (1-201), and the outer side of the cold head shell is provided with a red copper heat dissipation part (1-202).

10. A dual-headed opposing refrigeration structure as claimed in claim 1 or 9, wherein: the end part of the cold head shell (1-200) is provided with a cold guiding head (1-203).

Images