Vacuum testing device and manufacturing method of coaxial pulse tube refrigerator

Abstract

The present invention discloses a vacuum testing device and manufacturing method for a coaxial pulse tube refrigerator, comprising a test vacuum chamber, a cable socket, an inner sealing flange, an outer sealing flange, and a hot end flange, wherein the five parts are connected by screws. The vacuum chamber is connected to the cable socket to form an end face static seal; the cable plug is connected to the outer sealing flange to form an end face static seal; the inner sealing flange and the outer sealing flange simultaneously form inner and outer end face static seals and radial static seals with the hot end and the hot end flange through sealing rings and sealing gaskets. A high vacuum environment is achieved at the cold head position through a vacuum pump, and the transmission of a test signal is achieved through a cable plug. The present invention is applied to a coaxial pulse tube refrigerator without a sealing flange. After the vacuum testing device is installed with the refrigerator, the performance test of the refrigerator under a high vacuum environment can be achieved. The problem of difficulty and high cost of vacuum testing of refrigerators without sealing flanges is solved, and the structural design freedom of the coaxial pulse tube refrigerator is improved.

Description

Technical Field

[0001] The invention relates to a vacuum testing device for a mechanical refrigerator, and in particular to a vacuum testing device for a coaxial pulse tube refrigerator without a sealing flange and a manufacturing method thereof. Background Art

[0002] The coaxial pulse tube refrigerator has no moving parts at the cold end, and has the characteristics of small mechanical vibration, small electromagnetic interference, and long life. At the same time, compared with the linear pulse tube refrigerator and the U-shaped pulse tube refrigerator, it also has the advantages of small structure and easy coupling to obtain cooling capacity. It has great advantages and wide application value in the fields of aerospace, low-temperature superconductivity, medical equipment, mobile communication base stations, etc.

[0003] At present, there are coaxial pulse tube refrigerators with sealing flanges ( Figure 1 ) is widely used. Due to the need for coupling and achieving vacuum, the sealing flange usually increases with the increase of the size of the cold head. For areas where there are strict restrictions on weight and cold head size, the coaxial pulse tube refrigerator without sealing flange (Figure 2) can not only significantly reduce the weight of the cold finger, but also relax the size restrictions of the sealing flange and the cold head, and improve the freedom of structural design. However, when performing vacuum testing on the coaxial pulse tube refrigerator without sealing flange, since there is no sealing flange to achieve cold end vacuum, it needs to be placed in a vacuum tank as a whole, which has the problem of difficult and high cost of vacuum testing. Therefore, designing a vacuum testing device for coaxial pulse tube refrigerators without sealing flanges is of significance and value to the development and application of coaxial pulse tube refrigerators. Summary of the invention

[0004] In view of the characteristics of a coaxial pulse tube refrigerator without sealing flange, the present invention provides a vacuum testing device and a manufacturing method of the coaxial pulse tube refrigerator.

[0005] The purpose of the present invention is to design a vacuum testing device for a coaxial pulse tube refrigerator. Through the present invention, the coaxial pulse tube refrigerator without a sealing flange can be tested in a high vacuum environment in a simple and low-cost manner, giving full play to the advantages of high structural design freedom and light weight of the coaxial pulse tube refrigerator without a sealing flange, and greatly enhancing the structural diversity and practicality of the coaxial pulse tube refrigerator without a sealing flange.

[0006] A vacuum testing device for a coaxial pulse tube refrigerator is invented, as shown in Figures 3 and 4, and includes a test vacuum chamber 1, a cable socket 2, an inner sealing flange 3, an outer sealing flange 4, a hot end flange 6, etc., and is characterized in that: the test vacuum chamber 1 and the cable socket 2 are both hollow cylindrical, the inner diameter of the cylinder is larger than the outer diameter of the cold head 14, the top of the test vacuum chamber 1 is provided with a vacuum extraction port 15 for connecting a vacuum extraction device, and the cable socket 2 is provided with a cable plug installation position 21 on the side for installing a cable plug 19; the inner sealing flange 3 is in the shape of two hollow semi-discs, the inner diameter of the semi-discs is smaller than the outer diameter of the cold head 14, and is also smaller than the outer diameter of the upper end face of the hot end 7. This structure can avoid the cold head 14 during installation, and at the same time achieve coordination with the size of the hot end 7. There is a raised sealing pressure ring on the contact surface between the inner sealing flange 3 and the sealing gasket 5, which can form an inner end face after connection. Static seal; the outer sealing flange 4 is disc-shaped, and there is a raised sealing pressure ring on the contact surface with the sealing gasket 5, which can form an outer end face static seal after connection; the hot end flange 6 is two hollow bowl-shaped pieces, the inner diameter size of the middle part of the bowl is equal to the outer diameter size of the hot end 7, and the inner diameter size of the bottom of the bowl is smaller than the outer diameter size of the hot end 7, which is used for axial positioning of the hot end 7; wherein the vacuum chamber 1 is connected to the cable socket 2 through the third screw 13 and the third sealing ring 12 to form an end face static seal; the inner sealing flange 3 is connected to the outer sealing flange 4 through the first screw 10; the cable socket 2 is connected to the outer sealing flange 4 and the hot end flange 6 through the second screw 11 and the second sealing ring 9, and forms an end face static seal with the outer sealing flange 4; the inner sealing flange 3 and the outer sealing flange 4 simultaneously form inner and outer end face static seals and radial static seals with the hot end 7 and the hot end flange 6 through the sealing gasket 5 and the first sealing ring 8. Thus, a vacuum test device that can be applied to a coaxial pulse tube refrigerator without a sealing flange is formed.

[0007] The specific production method is as follows:

[0008] The main machined parts of the vacuum test device include: a test vacuum chamber 1, a cable socket 2, an inner sealing flange 3, an outer sealing flange 4, a sealing gasket 5, and a hot end flange 6. The test vacuum chamber 1 is a hollow cylindrical shape, which is turned as a whole. The inner diameter of the cylinder is larger than the outer diameter of the cold head 14, and there is a vacuum extraction port 15 on the top. The cable socket 2 is a hollow cylindrical shape, which is turned as a whole. The inner diameter of the cylinder is larger than the outer diameter of the cold head 14, and the cable plug installation position 21 is milled on the side. The inner sealing flange 3 is in the shape of two hollow semi-discs, which are turned as a whole and then cut apart. The inner diameter of the semi-disc is smaller than the outer diameter of the cold head 14, and smaller than the outer diameter of the upper end face of the hot end 7. A raised sealing pressure ring is turned on the contact surface with the sealing gasket 5. The outer sealing flange 4 is a disc shape, which is turned as a whole. A raised sealing pressure ring is turned on the contact surface with the sealing gasket 5. The sealing gasket 5 is in the shape of a circular disk, made of rubber, and is formed by die pressing. The inner hole size is equal to the inner diameter size of the inner sealing flange 3, and the outer diameter size is larger than the outer diameter size of the sealing pressure ring on the outer sealing flange 4. The hot end flange 6 is in the shape of two hollow inner round and outer square bowls, which are formed by turning the whole and then cutting. The inner diameter size of the middle part of the bowl is equal to the outer diameter size of the hot end 7, and the inner diameter size of the bottom of the bowl is smaller than the outer diameter size of the hot end 7. It is used for axial positioning of the hot end 7, and the connecting pipe avoidance hole 23 is milled laterally. Vacuum test device and refrigerator installation: The hot end flange 6 is put on the hot end 7 from bottom to top and axially positioned, and the two pieces of the hot end flange 6 are connected by the fifth screw 22. The first sealing ring 8 is stretched to cover the cold head 14 and placed in the sealing groove of the hot end flange 6. The inner hole of the sealing gasket 5 is stretched to cover the cold head 14 and placed flat on the hot end 7 and the hot end flange 6. After the inner sealing flange 3 is connected to the outer sealing flange 4 by the first screw 10, it is placed on the sealing gasket 5, and the sealing gasket 5 is just embedded in the concave surface of the outer sealing flange 4. The vacuum chamber 1 is connected to the cable socket 2 by the third screw 13 and the third sealing ring 12 to form an end face static seal. The cable plug 19 is connected to the test component 16 by the lead 17, and is connected to the cable socket 2 by the fourth screw 20 and the fourth sealing ring 18 to form an end face static seal. The cable socket 2 is connected to the outer sealing flange 4 and the hot end flange 6 by the second screw 11 and the second sealing ring 9, and forms an end face static seal with the outer sealing flange 4. The inner sealing flange 3 and the outer sealing flange 4 form an end face static seal and a radial static seal with the hot end 7 and the hot end flange 6 by the first sealing ring 8 and the sealing gasket 5. The high vacuum environment at the cold head position of the refrigerator is realized by vacuuming through the vacuum pumping port 15, and the transmission of the test signal is realized through the cable plug 19. Thus, a vacuum test device that can be applied to a coaxial pulse tube refrigerator without a sealing flange is formed.

[0009] The present invention has the following characteristics:

[0010] 1) The coaxial pulse tube refrigerator of the device can realize the test conditions under high vacuum environment at the cold head position after the device and refrigerator are installed. This changes the current situation that the cold end vacuum is realized without a sealing flange and the whole device needs to be placed in a vacuum tank, thus reducing the difficulty and cost of vacuum testing.

[0011] 2) Due to the invention and application of the device, in the design of a coaxial pulse tube refrigerator without a sealing flange, the size restrictions of the sealing flange and the cold head are relaxed, which can improve the structural design freedom of the coaxial pulse tube refrigerator.

[0012] 3) A combined sealing method of the first sealing ring 8 and the sealing gasket 5 is adopted to achieve static sealing and radial static sealing at the hot end position at the same time. This sealing method ensures that the inside of the device can quickly reach a high vacuum environment.

[0013] 4) The parts structure of the device is relatively simple and can be processed by ordinary turning, milling, tapping and other mechanical processes. The installation process of the device and the refrigerator is easy to operate.

[0014] 5) The above characteristics indicate that the present invention can be well applied to the vacuum test of the coaxial pulse tube refrigerator without sealing flange, giving full play to the advantages of the coaxial pulse tube refrigerator without sealing flange, such as small weight and high freedom of structural design, and significantly improving the practicality of the coaxial pulse tube refrigerator without sealing flange. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is the cold end structure diagram of a coaxial pulse tube refrigerator with a sealed flange.

[0016] Figure 2 This is the cold end structure diagram of the coaxial pulse tube refrigerator without sealing flange.

[0017] Figure 3 A schematic diagram of a vacuum testing device for a coaxial pulse tube refrigerator without a sealing flange.

[0018] Figure 4 A cross-sectional view of a schematic diagram of a vacuum testing device.

[0019] Figure 5 This is a schematic diagram of the inner sealing flange structure.

[0020] Figure 6 A cross-sectional view showing a schematic diagram of the inner sealing flange structure.

[0021] Figure 7 Schematic diagram of the sealing gasket structure.

[0022] Figure 8 It is a schematic diagram of the hot end flange structure.

[0023] Fig. 9It is the left view of the hot end flange structure schematic diagram.

[0024] Among them: 1 is the test vacuum chamber, 2 is the cable socket, 3 is the inner sealing flange, 4 is the outer sealing flange, 5 is the sealing gasket, 6 is the hot end flange, 7 is the hot end, 8 is the first sealing ring, 9 is the second sealing ring, 10 is the first screw, 11 is the second screw, 12 is the third sealing ring, 13 is the third screw, 14 is the cold head, 15 is the vacuum extraction port, 16 is the test component, 17 is the lead, 18 is the fourth sealing ring, 19 is the cable plug, 20 is the fourth screw, 21 is the cable plug installation position, 22 is the fifth screw, and 23 is the connecting pipe avoidance hole. DETAILED DESCRIPTION

[0025] The specific implementation method of the present invention is further described in detail below with reference to the accompanying drawings.

[0026] The main machined parts of the vacuum testing device include: a test vacuum chamber 1, a cable socket 2, an inner sealing flange 3, an outer sealing flange 4, a sealing gasket 5, and a hot end flange 6.

[0027] The test vacuum chamber 1 is a hollow cylindrical shape, which is integrally turned, and the inner diameter of the cylinder is larger than the outer diameter of the cold head 14, and a vacuum extraction port 15 is provided on the top. The cable socket 2 is a hollow cylindrical shape, which is integrally turned, and the inner diameter of the cylinder is larger than the outer diameter of the cold head 14, and a cable plug installation position 21 is milled on the side.

[0028] like Figure 5 , Figure 6 As shown, the inner sealing flange 3 is in the shape of two hollow semi-circular discs, which are formed by turning as a whole and then cutting apart. The inner diameter of the semi-circular disc is smaller than the outer diameter of the cold head 14 and smaller than the outer diameter of the upper end surface of the hot end 7. A raised sealing pressure ring is turned on the contact surface with the sealing gasket 5. The outer sealing flange 4 is in the shape of a disc, which is turned as a whole and a raised sealing pressure ring is turned on the contact surface with the sealing gasket 5.

[0029] like Figure 7 As shown, the sealing gasket 5 is in the shape of an annular disk, made of rubber, and formed by mold pressing. The inner hole size is equal to the inner diameter size of the inner sealing flange 3, and the outer diameter size is larger than the outer diameter size of the sealing pressure ring on the outer sealing flange 4.

[0030] like Figure 8 , Fig. 9 As shown, the hot end flange 6 is in the shape of two hollow bowls, which are formed by turning the whole and then cutting. The inner diameter of the middle of the bowl is equal to the outer diameter of the hot end 7, and the inner diameter of the bottom of the bowl is smaller than the outer diameter of the hot end 7. It is used for axial positioning of the hot end 7, and a connecting pipe avoidance hole 23 is milled on the side.

[0031] Vacuum test equipment and refrigerator installation Figure 3 , Figure 4As shown, the hot end flange 6 is put on the hot end 7 from bottom to top and axially positioned, and the two pieces of the hot end flange 6 are connected by the fifth screw 22. The first sealing ring 8 is stretched to cover the cold head 14 and placed in the sealing groove of the hot end flange 6. The inner hole of the sealing gasket 5 is stretched to cover the cold head 14 and placed flat on the hot end 7 and the hot end flange 6. After the inner sealing flange 3 is connected to the outer sealing flange 4 by the first screw 10, it is placed on the sealing gasket 5, and the sealing gasket 5 is just embedded in the concave surface of the outer sealing flange 4. The vacuum chamber 1 is connected to the cable socket 2 by the third screw 13 and the third sealing ring 12 to form a static end face seal. The cable plug 19 is connected to the test component 16 by the lead 17, and is connected to the cable socket 2 by the fourth screw 20 and the fourth sealing ring 18 to form a static end face seal. The cable socket 2 is connected to the outer sealing flange 4 and the hot end flange 6 by the second screw 11 and the second sealing ring 9, and forms a static end face seal with the outer sealing flange 4. The inner sealing flange 3 and the outer sealing flange 4 form inner and outer end surface static seals and radial static seals with the hot end 7 and the hot end flange 6 through the sealing gasket 5 and the first sealing ring 8. The vacuum is drawn through the vacuum extraction port 15 to achieve a high vacuum environment at the cold head position of the refrigerator, and the test signal is transmitted through the cable plug 19.

[0032] Finally, it should be noted that: those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A vacuum test device for a coaxial pulse tube refrigerator, comprising a test vacuum chamber (1), a cable socket (2), an inner sealing flange (3), an outer sealing flange (4), and a hot end flange (6), characterized in that: The test vacuum chamber (1) and the cable socket (2) are both hollow cylindrical, the inner diameter of the cylinder is larger than the outer diameter of the cold head (14), the top of the test vacuum chamber (1) is provided with a vacuum extraction port (15) for connecting a vacuum extraction device, and the cable socket (2) is provided with a cable plug installation position (21) on the side for installing a cable plug (19); the inner sealing flange (3) is in the shape of two hollow semi-discs, the inner diameter of the semi-discs is smaller than the outer diameter of the upper end surface of the hot end (7), this structure can avoid the cold head (14) when installed and simultaneously achieve the matching with the size of the hot end (7), there is a raised sealing pressure ring on the contact surface with the sealing gasket (5), and after connection, a static seal can be formed on the inner end surface; the outer sealing flange (4) is in the shape of a disc, and there is a raised sealing pressure ring on the contact surface with the sealing gasket (5), and after connection, a static seal can be formed on the outer end surface; the hot end flange (6) is in the shape of two hollow bowls, the middle of the bowl The inner diameter is equal to the outer diameter of the hot end (7), and the inner diameter of the bottom of the bowl is smaller than the outer diameter of the hot end (7), and is used for axial positioning of the hot end (7); wherein the vacuum chamber (1) is connected to the cable socket (2) via a third screw (13) and a third sealing ring (12) to form an end face static seal; the inner sealing flange (3) is connected to the outer sealing flange (4) via a first screw (10); the cable socket (2) is connected to the outer sealing flange (4) and the hot end flange (6) via a second screw (11) and a second sealing ring (9), and forms an end face static seal with the outer sealing flange (4); the inner sealing flange (3) and the outer sealing flange (4) simultaneously form inner and outer end face static seals and radial static seals with the hot end (7) and the hot end flange (6) via a sealing gasket (5) and a first sealing ring (8), thereby forming a vacuum testing device applicable to a coaxial pulse tube refrigerator without a sealing flange.

2. A method for manufacturing a vacuum testing device for a coaxial pulse tube refrigerator as claimed in claim 1, characterized in that Here’s how: The main machined parts of the vacuum testing device include: a test vacuum chamber (1), a cable socket (2), an inner sealing flange (3), an outer sealing flange (4), a sealing gasket (5), and a hot end flange (6); wherein the test vacuum chamber (1) is in the shape of a hollow cylinder, which is integrally formed by turning, the inner diameter of the cylinder is larger than the outer diameter of the cold head (14), and a vacuum extraction port (15) is provided on the top; the cable socket (2) is in the shape of a hollow cylinder, which is integrally formed by turning, the inner diameter of the cylinder is larger than the outer diameter of the cold head (14), and a cable plug installation position (21) is milled on the side; the inner sealing flange (3) is in the shape of two hollow semi-discs, which are integrally turned and then cut apart, the inner diameter of the semi-discs is smaller than the outer diameter of the upper end surface of the hot end (7), and the sealing gasket is provided on the hot end flange (6). (5) a raised sealing pressure ring is turned on the contact surface; the outer sealing flange (4) is in the shape of a disc and is turned as a whole. A raised sealing pressure ring is turned on the contact surface with the sealing gasket (5). The sealing gasket (5) is in the shape of a circular ring disk and is made of rubber. It is pressed by die opening. The inner hole size is equal to the inner diameter size of the inner sealing flange (3), and the outer diameter size is larger than the outer diameter size of the sealing pressure ring on the outer sealing flange (4); the hot end flange (6) is in the shape of two hollow bowls, which are turned as a whole and then cut apart. The inner diameter size of the middle part of the bowl is equal to the outer diameter size of the hot end (7), and the inner diameter size of the bottom part of the bowl is smaller than the outer diameter size of the hot end (7). It is used for axial positioning of the hot end (7), and a connecting pipe avoidance hole (23) is milled on the side; vacuum testing device and refrigeration Machine installation: The hot end flange (6) is put on the hot end (7) from bottom to top and axially positioned, and the two pieces of the hot end flange (6) are connected by the fifth screw (22); the first sealing ring (8) is stretched to cover the cold head (14) and placed in the sealing groove of the hot end flange (6); the inner hole of the sealing gasket (5) is stretched to cover the cold head (14) and placed flat on the hot end (7) and the hot end flange (6); the inner sealing flange (3) is connected to the outer sealing flange (4) by the first screw (10), and then placed on the sealing gasket (5), and the sealing gasket (5) is just embedded in the concave surface of the outer sealing flange (4); the vacuum chamber (1) is connected to the cable socket (2) by the third screw (13) and the third sealing ring (12) to form an end face static seal, and the cable The plug (19) is connected to the test component (16) through the lead wire (17), and is connected to the cable socket (2) through the fourth screw (20) and the fourth sealing ring (18) to form an end face static seal. The cable socket (2) is connected to the outer sealing flange (4) and the hot end flange (6) through the second screw (11) and the second sealing ring (9), and forms an end face static seal with the outer sealing flange (4). The inner sealing flange (3) and the outer sealing flange (4) form an end face static seal and a radial static seal with the hot end (7) and the hot end flange (6) through the first sealing ring (8) and the sealing gasket (5). A high vacuum environment is achieved at the cold head position of the refrigerator by vacuuming through the vacuum extraction port (15), and the test signal is received through the cable plug (19).

Images