Compressor for cryogenic refrigerator

Abstract

The utility model relates to a compressor for a cryogenic refrigerator, and aims to enable the disassembly operation of a control panel in the compressor for the cryogenic refrigerator to be easy. A compressor (12) for a cryogenic refrigerator (10) is provided with: a control panel (50); and a compressor housing (24) which is provided with a front panel (24a) and accommodates the control panel (50). The front panel (24a) is provided with: a first panel portion (28) to which piping connection is provided; and a second panel part (29) which is detachably connected to the first panel part (28) and on which a control panel (50) is mounted. The control panel (50) can be pulled forward from the compressor housing (24) together with the second panel portion (29).

Description

[0001] This application claims priority based on Japanese Patent Application No. 2023-101013 filed on June 20, 2023. The entire contents of this Japanese application are incorporated herein by reference. Technical Field

[0002] The utility model relates to a compressor for an ultra-low temperature refrigerator. Background Art

[0003] Typically, a cryogenic refrigerator such as a Gifford-McMahon (GM) refrigerator includes a compressor for supplying high-pressure refrigerant gas to a cold head. The compressor includes components such as a compressor body, an oil separator, an adsorber, a storage tank, and a control device.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2001-74326

[0005] In the previous ultra-low temperature refrigerator compressor, the refrigerant gas supply pipe and recovery pipe of the cold head are connected to the front panel of the compressor frame. In addition, the coolant supply pipe and recovery pipe of the heat exchanger set in the compressor frame for cooling the compressor are also connected to the front panel. The control panel of the compressor is arranged behind the front panel in the compressor frame.

[0006] In a compressor with this frame design, when removing the control panel, the operator first removes the front panel from the compressor frame. However, in order to remove the front panel, it is necessary to extract the refrigerant gas from the refrigerant gas piping and the coolant from the coolant piping before removing these piping from the front panel. In addition, other compressor components such as adsorbers are sometimes fastened to the front panel, and in this case, it is also necessary to remove these components from the front panel in advance. Therefore, in previous designs, the disassembly operation of removing the control panel from the compressor requires a preliminary process of disassembling the compressor into its individual components, which is quite time-consuming. Summary of the invention

[0007] One of the exemplary purposes of an embodiment of the present invention is to facilitate the disassembly of a control panel in a compressor for a cryogenic refrigerator.

[0008] According to one embodiment of the utility model, a compressor for a cryogenic refrigerator includes a control panel and a compressor frame having a front panel and accommodating the control panel. The front panel includes: a first panel portion, which provides a pipe connection; and a second panel portion, which is detachably connected to the first panel portion and carries the control panel.

[0009] According to the utility model, the disassembly operation of the control panel in the compressor for a cryogenic refrigerator can be facilitated. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a diagram schematically showing a cryogenic refrigerator according to an embodiment.

[0011] Figure 2 It is a schematic perspective view showing the appearance of a compressor according to an embodiment.

[0012] Figure 3 It is a schematic perspective view showing the internal device arrangement of the compressor according to the embodiment.

[0013] Figure 4 It is a schematic perspective view showing the internal device arrangement of the compressor according to the embodiment.

[0014] Figure 5 It is a plan view schematically showing a part of the front panel of the compressor housing according to the embodiment.

[0015] Figure 6 It is a cross-sectional view schematically showing a part of the front panel of the compressor housing according to the embodiment.

[0016] Figure 7 It is a schematic plan view showing the back side of the control panel according to the embodiment.

[0017] Figure 8 It is a schematic plan view showing a passage area of ​​a control panel according to the embodiment.

[0018] In the figure: 10-ultra-low temperature refrigerator, 12-compressor, 24-compressor frame, 24a-front panel, 24d-bottom panel, 28-first panel part, 28a-first panel side, 28b-second panel side, 29-second panel part, 50-control panel, 52-castor, 52a-castor fixing part, 58-connecting part. DETAILED DESCRIPTION

[0019] Hereinafter, the embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description and the accompanying drawings, the same or equivalent constituent elements, components and processes are marked with the same symbols, and repeated descriptions are appropriately omitted. For the convenience of explanation, the scale and shape of each part are appropriately set in each of the accompanying drawings, and unless otherwise specified, they are not interpreted as limiting. The embodiments are illustrative and do not limit the scope of the present invention in any way. All the features or their combinations described in the embodiments are not necessarily the essence of the invention.

[0020] Figure 11 is a diagram schematically showing a cryogenic refrigerator 10 according to an embodiment. The cryogenic refrigerator 10 is used to perform cryogenic cooling on an object or a medium. For example, the cryogenic refrigerator 10 can be used as a cooling source for a superconducting magnet device. The superconducting magnet device can be mounted on a strong magnetic field utilizing device as a magnetic field source of, for example, a single crystal pulling device, an NMR (Nuclear Magnetic Resonance) system, an MRI (Magnetic Resonance Imaging) system, an accelerator such as a cyclotron, a high energy physics system such as a nuclear fusion system, or other strong magnetic field utilizing devices (not shown), thereby generating a strong magnetic field required by the device.

[0021] The cryogenic refrigerator 10 includes a compressor 12 and a cold head 14. The compressor 12 is configured to recover the refrigerant gas of the cryogenic refrigerator 10 from the cold head 14, and to supply the refrigerant gas to the cold head 14 again after pressurizing the recovered refrigerant gas. The compressor 12 is also referred to as a compressor unit. The cold head 14 is also referred to as an expander, and has a room temperature portion 14a and a low temperature portion 14b (also referred to as a cooling stage). The refrigerant gas is also referred to as a working gas, and helium is usually used, but other suitable gases may also be used. The refrigeration cycle of the cryogenic refrigerator 10 is constituted by the compressor 12 and the cold head 14, thereby cooling the low temperature portion 14b to a desired ultra-low temperature. The low temperature portion 14b can cool a cooled object such as a superconducting magnet, for example.

[0022] As an example, the cryogenic refrigerator 10 is a single-stage or two-stage Gifford-McMahon (GM) refrigerator, but may also be a pulse tube refrigerator, a Stirling refrigerator, or other types of cryogenic refrigerators. The cold head 14 has different structures depending on the type of the cryogenic refrigerator 10, but the compressor 12 uses a compressor with the following structure regardless of the type of the cryogenic refrigerator 10.

[0023] In addition, usually, the pressure of the refrigerant gas supplied from the compressor 12 to the cold head 14 and the pressure of the refrigerant gas recovered from the cold head 14 to the compressor 12 are both much higher than the atmospheric pressure, and can be respectively referred to as the first high pressure and the second high pressure. For the sake of convenience, the first high pressure and the second high pressure are respectively referred to as the high pressure and the low pressure. Typically, the high pressure is, for example, 2 to 3 MPa. The low pressure is, for example, 0.5 to 1.5 MPa, and the low pressure is, for example, about 0.8 MPa.

[0024] The compressor 12 is an oil-lubricated compressor for a cryogenic refrigerator, and includes a compressor body 16, a refrigerant gas pipeline 18, and an oil circulation pipeline 20. Figure 1In the figure, for ease of understanding, the refrigerant gas pipeline 18 is indicated by a solid line, and the oil circulation pipeline 20 is indicated by a dotted line. The compressor 12 includes a compressor housing 24 that accommodates components of the compressor 12, such as the compressor body 16, the refrigerant gas pipeline 18, and the oil circulation pipeline 20.

[0025] The compressor body 16 is configured to compress the refrigerant gas sucked from the suction port thereof and discharge it from the discharge port. In the compressor body 16, oil is used for cooling and lubrication, and the sucked refrigerant gas is directly exposed to the oil in the compressor body 16. Therefore, the refrigerant gas is sent from the discharge port in a state mixed with a small amount of oil.

[0026] The compressor body 16 may be, for example, a vortex pump, a rotary pump, or other pumps that increase the pressure of the refrigerant gas. The compressor body 16 may be configured to discharge a constant refrigerant gas flow rate. Alternatively, the compressor body 16 may be configured to make the discharged refrigerant gas flow rate variable. The compressor body 16 is sometimes also referred to as a compression chamber.

[0027] The refrigerant gas pipeline 18 includes a discharge port 30, a suction port 31, a discharge flow path 32, and a suction flow path 33. The discharge port 30 is an outlet of the refrigerant gas provided in the compressor frame 24 in order to deliver the refrigerant gas pressurized to a high pressure by the compressor body 16 from the compressor 12, and the suction port 31 is an inlet of the refrigerant gas provided in the compressor frame 24 in order to recover the low-pressure refrigerant gas into the compressor 12. The discharge flow path 32 and the suction flow path 33 are accommodated in the compressor frame 24. The discharge port of the compressor body 16 is connected to the discharge port 30 through the discharge flow path 32, and the suction port 31 is connected to the suction port of the compressor body 16 through the suction flow path 33.

[0028] The refrigerant gas pipeline 18 is connected to the cold head 14. The room temperature portion 14a of the cold head 14 is provided with a high pressure port 40 and a low pressure port 41. The high pressure port 40 is connected to the discharge port 30 via a high pressure pipe 42, and the low pressure port 41 is connected to the suction port 31 via a low pressure pipe 43.

[0029] An oil separator 34 and an adsorber 35 are provided on the discharge flow path 32. The purpose of the oil separator 34 is to separate the oil mixed into the refrigerant gas when the refrigerant gas passes through the compressor body 16. The purpose of the adsorber 35 is to remove, by adsorption, the oil or other pollutants remaining in the refrigerant gas, such as vaporized oil, from the refrigerant gas. The oil separator 34 and the adsorber 35 are connected in series. On the discharge flow path 32, the oil separator 34 is arranged on the compressor body 16 side, and the adsorber 35 is arranged on the discharge port 30 side.

[0030] An oil return line 21 is provided to connect the oil separator 34 to the compressor body 16. The oil recovered by the oil separator 34 can be returned to the compressor body 16 through the oil return line 21. A filter for removing dust contained in the oil separated by the oil separator 34 and a throttle hole for controlling the amount of oil returned to the compressor body 16 may be provided on the way of the oil return line 21.

[0031] On the other hand, an accumulator 36 is provided in the suction flow path 33. The accumulator 36 is set to have a capacity for removing pulsation included in the low-pressure refrigerant gas returning from the cold head 14 to the compressor 12.

[0032] In addition, a bypass valve 38 is provided on the refrigerant gas pipeline 18 to connect the discharge flow path 32 to the suction flow path 33 in a manner bypassing the compressor body 16. As an example, the bypass valve 38 branches from the discharge flow path 32 between the oil separator 34 and the adsorber 35 and is connected to the suction flow path 33 between the compressor body 16 and the accumulator 36. The bypass valve 38 is provided for the purpose of controlling the refrigerant gas flow rate and / or balancing the pressure between the discharge flow path 32 and the suction flow path 33 when the compressor 12 is stopped.

[0033] The oil circulation pipeline 20 connects the oil outlet of the compressor body 16 to the oil inlet so that the oil flowing out of the compressor body 16 returns to the compressor body 16. The oil circulation pipeline 20 may be provided with a throttle hole for controlling the oil flow rate flowing through the inside. In addition, the oil circulation pipeline 20 may be provided with a filter for removing dust contained in the oil.

[0034] The compressor 12 further includes a heat exchanger 22 that is housed in a compressor housing 24 and cools the compressor 12. The heat exchanger 22 includes a refrigerant gas cooler 22a that cools the refrigerant gas line 18 by exchanging heat between the refrigerant gas and the cooling medium, and an oil cooler 22b that cools the oil circulation line 20 by exchanging heat between the oil and the cooling medium.

[0035] The refrigerant gas cooler 22a is provided between the compressor body 16 and the oil separator 34 on the discharge flow path 32, and cools the high-pressure refrigerant gas heated by the compression heat generated by the compression of the refrigerant gas in the compressor body 16. The refrigerant gas cooler 22a cools the refrigerant gas by heat exchange between the refrigerant gas and the cooling medium. The cooled refrigerant gas is purified in the oil separator 34 and the adsorber 35. In addition, the oil cooler 22b cools the oil by heat exchange between the oil flowing out from the oil outlet of the compressor body 16 to the oil circulation pipe 20 and the cooling medium. The cooled oil returns to the compressor body 16 from the oil inlet of the compressor body 16. The cooling medium is supplied to the compressor 12 from the outside through the cooling medium inlet 44, and is discharged from the cooling medium outlet 45 to the outside of the compressor 12 after passing through the refrigerant gas cooler 22a and the oil cooler 22b. The cooling medium is a cooling liquid, for example, water. Thus, the compression heat generated in the compressor body 16 is discharged together with the cooling medium to the outside of the compressor 12. In addition, the cooling medium may be cooled by, for example, a chiller (not shown) and then supplied again.

[0036] In this embodiment, the heat exchanger 22 is a shell-and-tube heat exchanger. Therefore, the heat exchanger 22 has an outer tube and an inner tube inserted into the outer tube. The cooling medium is supplied to one of the outer tube and the inner tube, and the fluid to be cooled is supplied to the other tube, thereby enabling heat exchange between the cooling medium and the target fluid to cool the fluid. For example, in the refrigerant gas cooler 22a, cooling water can be supplied to the outer tube, and refrigerant gas can be supplied to the inner tube. In the oil cooler 22b, cooling water can be supplied to the outer tube, and oil can be supplied to the inner tube.

[0037] During the operation of the ultra-low temperature refrigerator 10, the refrigerant gas is supplied from the compressor 12 to the cold head 14, and the periodic volume change of the expansion space of the refrigerant gas in the cold head 14 and the pressure change of the refrigerant gas in the expansion space synchronously therewith constitute a refrigeration cycle (for example, a GM cycle), and the low temperature portion 14b of the cold head 14 is cooled to a desired ultra-low temperature. For example, in the case where the cold head 14 is a two-stage type, the first stage cooling stage is cooled to a first cooling temperature in the range of about 30K to about 80K, for example, and the second stage cooling stage is cooled to a second cooling temperature lower than the first cooling temperature, for example, to 1K to 20K. The second cooling temperature can be a liquid helium temperature of about 4.2K or a temperature lower than it.

[0038] The refrigerant gas recovered from the cold head 14 to the compressor 12 flows from the low-pressure port 41 through the low-pressure pipe 43 into the suction port 31 of the compressor 12. The refrigerant gas is recovered to the suction port of the compressor body 16 after passing through the storage tank 36 on the suction flow path 33. The refrigerant gas is compressed and pressurized by the compressor body 16. At this time, the temperature of the refrigerant gas is increased based on the compression heat. The refrigerant gas sent out from the discharge port of the compressor body 16 is cooled in the refrigerant gas cooler 22a of the heat exchanger 22, and leaves the compressor 12 from the discharge port 30 after passing through the oil separator 34 and the adsorber 35. The refrigerant gas is supplied to the inside of the cold head 14 via the high-pressure pipe 42 and the high-pressure port 40.

[0039] Figure 2 It is a schematic perspective view showing the appearance of the compressor 12 according to the embodiment. Figure 3 and Figure 4 It is a schematic perspective view showing the internal device arrangement of the compressor 12 according to the embodiment. Figure 2 and Figure 3 1 is a perspective view of the compressor 12 as viewed from the front. Figure 4 The diagram shows a perspective view of the compressor 12 as viewed from the rear. Figure 3 and Figure 4 2 shows a state where several panels of the compressor frame 24 are removed in order to show the configuration of the internal equipment of the compressor 12. Figure 2 As shown, the compressor frame 24 of the compressor 12 is in the shape of a rectangular parallelepiped with six faces, that is, it has a front panel 24a, a back panel 24b, a top panel 24c, a bottom panel 24d, and two side panels 24e and 24f on the left and right. The back panel 24b faces the side opposite to the front panel 24a. Between the front panel 24a and the back panel 24b, the top panel 24c is arranged at the top, the bottom panel 24d is arranged at the bottom, and the side panels 24e and 24f are arranged on the left and right sides.

[0040] The front panel 24a includes two panel parts that are combined to form the front panel 24a, specifically, a first panel part 28 and a second panel part 29. The first panel part 28 provides piping connection, and the second panel part 29 provides a user interface and electrical connection. Figure 5 As described above, the second panel portion 29 and the first panel portion 28 are detachably connected together.

[0041] The first panel portion 28 and the second panel portion 29 have a longitudinal shape having a total length equivalent to the height of the compressor 12, and are adjacent to each other in the left and right directions when viewed from the front. The first panel portion 28 corresponds to the right half of the front panel 24a, and the second panel portion 29 corresponds to the left half of the front panel 24a. These panel portions are thin plate-shaped members made of metal such as stainless steel or other appropriate materials.

[0042] like Figure 2 and Figure 3 As shown, the first panel portion 28 is provided with a discharge port 30, a suction port 31, a cooling medium inlet 44, and a cooling medium outlet 45. In this way, the inlet and outlet of the fluid such as the refrigerant gas in the compressor 12 are concentrated in the first panel portion 28. The second panel portion 29 is not provided with such a fluid inlet and outlet.

[0043] An operation panel 25 for receiving input for controlling the cryogenic refrigerator 10 from a user of the cryogenic refrigerator 10 and / or for displaying information related to the cryogenic refrigerator 10 is provided on the front surface of the second panel portion 29 (the surface facing the outside of the compressor frame 24 ).

[0044] Furthermore, a circuit breaker 54 and a cold head connector 55 are provided on the front surface of the second panel portion 29. The circuit breaker 54 is connected to an external power source such as a commercial power source, thereby supplying power to the ultra-low temperature refrigerator 10. The cold head connector 55 is connected to an electrical wiring for supplying power from the compressor 12 to the cold head 14 and for controlling the cold head 14 through the control panel 50. The electrical connection between the compressor 12 and the cold head 14 is established through the electrical wiring.

[0045] A main switch 56 is provided on the circuit breaker 54. The main switch 56 is a switch for switching the ultra-low temperature refrigerator 10 on and off. When the main switch 56 is on, the compressor 12 and the cold head 14 operate, and when the main switch 56 is off, the compressor 12 and the cold head 14 stop operating.

[0046] A control panel 50 is mounted on the second panel portion 29. The control panel 50 is mounted on the back side (the side facing the inside of the compressor frame 24) of the second panel portion 29 and is accommodated in the compressor frame 24. The details will be described later, but Figure 3 and Figure 4 As shown by arrow A in FIG. 2 , the control panel 50 can be pulled out forward from the compressor housing 24 together with the second panel portion 29 .

[0047] The control panel 50 is a control device for controlling the compressor 12. The control panel 50 may include a control circuit configured to receive outputs from various sensors provided on the cryogenic refrigerator 10 and control various devices of the cryogenic refrigerator 10 according to the sensor outputs. A plurality of electrical installation parts including sensors such as temperature sensors and pressure sensors may be accommodated in the compressor frame 24. Each sensor may be connected to the control panel 50 via a communication cable.

[0048] The temperature sensor may include a refrigerant gas temperature sensor provided on the refrigerant gas pipeline 18, an oil temperature sensor provided on the oil circulation pipeline 20, a coolant temperature sensor provided on the coolant piping of the heat exchanger 22, and a cooling temperature sensor provided on the low temperature portion 14b of the cold head 14, etc.

[0049] For example, Figure 1 As shown, the first temperature sensor 46 is arranged upstream of the heat exchanger 22 on the discharge flow path 32 of the refrigerant gas pipeline 18, thereby measuring the temperature of the refrigerant gas flowing from the compressor body 16 into the heat exchanger 22. The second temperature sensor 47 is arranged downstream of the heat exchanger 22 on the refrigerant gas pipeline 18, thereby measuring the temperature of the refrigerant gas flowing from the heat exchanger 22 into the oil separator 34. The third temperature sensor 48 is arranged upstream of the heat exchanger 22 on the oil circulation pipeline 20, thereby measuring the temperature of the oil flowing from the compressor body 16 into the heat exchanger 22. The fourth temperature sensor 49 is arranged downstream of the heat exchanger 22 on the oil circulation pipeline 20, thereby measuring the temperature of the oil flowing from the heat exchanger 22 into the compressor body 16. The temperature sensor is configured to output a signal indicating the measured temperature to the control panel 50. The temperature sensor may be, for example, a thermistor. The temperature sensor may be mounted on the outer surface of the pipe constituting the refrigerant gas pipeline 18 and the oil circulation pipeline 20.

[0050] Furthermore, the first pressure sensor 37a may be disposed on the discharge flow path 32 to measure the pressure of the refrigerant gas flowing through the discharge flow path 32. The first pressure sensor 37a is configured to output a first measured pressure signal PH indicating the measured pressure to the control panel 50. The second pressure sensor 37b is disposed on the suction flow path 33 to measure the pressure of the refrigerant gas flowing through the suction flow path 33. The second pressure sensor 37b is configured to output a second measured pressure signal PL indicating the measured pressure to the control panel 50.

[0051] The electrical components controlled according to the sensor output may include, for example, a compressor motor driving the compressor body 16, a bypass valve 38, and a cold head motor driving the cold head 14. The control panel 50 may include a compressor inverter for controlling the rotation speed of the compressor motor and / or a cold head inverter for controlling the rotation speed of the cold head motor.

[0052] Re-reference Figure 2 to Figure 4 Casters 52 are installed on the bottom panel 24d to facilitate the movement or transportation of the compressor 12. Four casters 52 are respectively arranged at the four corners of the bottom panel 24d. Figure 3 and Figure 4 As shown, in order to fix the caster 52 to the bottom panel 24d, a caster fixing portion 52a is provided at the upper surface end of the bottom panel 24d for each caster 52. As an example, the caster fixing portion 52a may include a nut for fixing the caster 52 to the bottom panel 24d. The caster 52 is provided with a bolt portion extending upward from the caster 52, and the bolt portion extends toward the upper side of the bottom panel 24d after passing through the receiving hole of the bottom panel 24d and is fixed to the bottom panel 24d by the above-mentioned nut.

[0053] like Figure 3 and Figure 4 As shown, the compressor frame 24 has a frame structure 26 that supports the panel and bears the structural strength. The panel is detachably mounted on the frame structure 26. Figure 2 As shown, when the panel is mounted on the frame structure 26, the equipment in the compressor 12 is covered by the panel. The panel can be mounted on the frame structure 26 by a suitable method such as screwing. When the panel is removed from the frame structure 26, the user or operator can easily access the equipment in the compressor 12 from the opening of the frame structure 26, and the maintenance or manufacturing work of the compressor 12 can be effectively performed.

[0054] For example, a rectangular back outer frame 26a is provided on the back side of the compressor frame 24, which is provided in a manner to surround the back side and constitutes a part of the frame structure 26. The four sides of the rectangular shape of the back panel 24b are respectively detachably mounted on the back outer frame 26a. The upper ends of the back outer frame 26a are connected to the upper edge ends of the front panel 24a through two side frames 26b, and the lower part of the back outer frame 26a is connected to the rear edge of the bottom panel 24d. In addition, the lower edge of the front panel 24a is connected to the front edge of the bottom panel 24d. The four sides of the top panel 24c are detachably mounted on the upper part of the back outer frame 26a and the front panel 24a and the two side frames 26b. The four sides of the side panel 24e are detachably mounted on the back outer frame 26a, the side of the first panel part 28, the side frame 26b and the bottom panel 24d. The four sides of the side panel 24f are detachably attached to the rear outer frame 26a, the side portion of the second panel portion 29, the side frame 26b, and the bottom panel 24d.

[0055] Conventional compressors have adopted a design in which the panels themselves forming each surface of the compressor frame bear the structural strength, so the panel thickness is large and its weight is also likely to increase. Therefore, it is not easy to install the panel in the manufacturing process or to disassemble the panel in the maintenance operation, which is a reason for the reduced operability for the operator. In contrast, according to the embodiment, the compressor frame 24 has a frame structure 26 that bears the structural strength, so that each panel such as the back panel 24b installed on the frame structure 26 can be thinned and lightened. This frame structure also helps to improve operability.

[0056] As described above, the main components of the compressor 12, such as the compressor body 16, the heat exchanger 22, the oil separator 34, the adsorber 35, the reservoir 36, and the control panel 50, are accommodated in the compressor frame 24. The oil separator 34, the adsorber 35, and the reservoir 36 are arranged on the bottom panel 24d in a manner close to the side panel 24e on one side, and are arranged in the compressor frame 24. The adsorber 35, the reservoir 36, and the oil separator 34 are arranged in order from the first panel portion 28 of the front panel 24a toward the back panel 24b. In addition, the compressor body 16 and the control panel 50 are arranged in the compressor frame 24 in a manner close to the other side panel 24f. As described above, the control panel 50 is mounted on the second panel portion 29 of the front panel 24a, and the compressor body 16 is arranged on the bottom panel 24d between the control panel 50 and the back panel 24b.

[0057] In addition, if Figure 4 As shown, the heat exchanger 22 is configured to be spirally bent along the back of the compressor frame 24. As a result, the sleeve of the heat exchanger 22 with a longer total length can be arranged compactly so as to save space. In addition, the spiral shape of the heat exchanger 22 is formed to leave the central part of the back of the compressor frame 24 empty. That is, an internal access opening 62 is formed in the central part of the back of the compressor frame 24 without the heat exchanger 22. In the manufacturing process of the compressor 12 or in the maintenance operation of the compressor 12 at the use site of the compressor 12, the operator can easily approach the equipment in the compressor 12 from the internal access opening 62. For example, the implementation of manufacturing operations such as pipe welding and joint tightening or various maintenance operations (for example, replacement of consumables such as filters, replacement and repair of equipment such as failed sensors, etc.) can be carried out through the internal access opening 62.

[0058] Figure 5 2 is a plan view schematically showing a portion of the front panel 24a according to the embodiment. Figure 6 It is a side view which schematically shows a part of the front panel 24a which concerns on embodiment.

[0059] As described above, the front panel 24a includes the first panel portion 28 and the second panel portion 29 which are detachably connected to each other. Figure 5 The upper back side of these two panel sections is shown in FIG. Figure 5 2 shows a state where the remaining parts of the compressor housing 24 such as the frame structure 26 and the top panel 24 c are removed from the front panel 24 a and the control panel 50 is removed from the second panel portion 29 .

[0060] The first panel portion 28 and the second panel portion 29 are detachably connected together by a connecting member 58. The connecting member 58 may be, for example, a fastening member such as a screw, a bolt, and a nut, or other detachable appropriate connecting member. The first panel portion 28 includes a first panel side 28a and a second panel side 28b, and the second panel portion 29 includes a first panel side 29a and a second panel side 29b. The first panel side 28a of the first panel portion 28 and the first panel side 29a of the second panel portion 29 are in contact with each other and are connected together by the connecting member 58. In this embodiment, the first panel portion 28 and the second panel portion 29 both have a longitudinal shape, and therefore can be connected together by a plurality of connecting members 58 (for example, connecting members 58 at three locations) in the length direction thereof.

[0061] The second panel side surface 28b of the first panel portion 28 is a side surface opposite to the first panel side surface 28a and faces toward Figure 2 The second panel side 29b of the second panel portion 29 is the side opposite to the first panel side 29a and faces toward Figure 2 The side panel 24f side is shown.

[0062] The first panel portion 28 includes an opening 60 that allows access to the connecting member 58 from the outside of the compressor frame 24. Specifically, the opening 60 is provided on the second panel side 28b of the first panel portion 28. A plurality of openings 60 may be provided on the second panel side 28b corresponding to a plurality of connecting members 58. Since the connecting member 58 and the opening 60 are provided at the same position in the longitudinal direction (i.e., the height direction) of the panel, the opening 60 functions as a so-called observation hole.

[0063] Figure 6 FIG. 2 shows the opening 60 and its vicinity on the second panel side 28b of the first panel portion 28. When the opening 60 is viewed from the outside of the compressor frame 24, as shown in FIG. Figure 6 As shown, the connector 58 can be visually observed from the opening 60. In this example, the diameter of the opening 60 is slightly larger than that of the connector 58, and the entire head of the connector 58 can be observed through the opening 60.

[0064] Therefore, the connection member 58 can be accessed from the outside of the compressor frame 24 through the opening 60. Figure 5 As shown, the width ( Figure 5 A tool 64 having a length corresponding to the horizontal dimension (in the figure) is inserted into the compressor frame 24 from the opening 60 and reaches the connecting member 58. When the connecting member 58 is a screw, the tool 64 may be, for example, a screwdriver. In this way, the opening 60 and the tool 64 may be used to operate the connecting member 58 to connect the first panel portion 28 and the second panel portion 29, or to release the connection.

[0065] As described above, the compressor 12 is equipped with various electrical components such as various sensors (e.g., pressure sensors 37a, 37b, temperature sensors 46-49) and bypass valve 38. These electrical components are housed in the compressor housing 24 and connected to the control panel 50. In order to achieve electrical connection between the electrical components and the control panel 50, as shown in FIG. Figure 4 and Figure 7 As shown, the control panel 50 includes a plurality of connectors 66. To these connectors 66, connectors of electric wiring (not shown) extending from electrical components are connected.

[0066] Figure 7 2 is a schematic plan view showing the back side of the control panel 50 according to the embodiment. Figure 4 and Figure 7 , a plurality of connectors 66 are provided on the back of the control panel 50. These connectors can be centrally arranged at a specific position on the back of the control panel 50. For example, as shown in the figure, a plurality of connectors 66 can be arranged at a position on the back of the control panel 50 close to the outside of the compressor frame 24 (for example, a position close to the panel of the compressor frame 24). In this way, when the panel (for example, the side panel 24f) is removed from the compressor frame 24, the connectors 66 are exposed near the opening of the frame structure 26. The operator can easily approach these connectors 66 from the outside of the compressor frame 24, so that the connection (or removal) operation between the electrical installation parts and the connectors 66 can be easily performed.

[0067] And, if Figure 7 As shown, a plurality of fixing members 68 (e.g., tie-wrap fixing seats) are provided on the back of the control panel 50, which detachably fix the electrical wiring used to connect the electrical installation components to the connector 66 on the control panel 50. The fixing members 68 are provided to connect the wiring path 70 (as an example, Figure 7 The fixing member 68 is shown by a dotted line in FIG. 1 and is fixed to the back of the control panel 50. By using such a fixing member 68, the electrical wiring can be arranged and arranged on the back of the control panel 50.

[0068] Figure 87 is a schematic top view showing the passage area 72 of the control panel 50 according to the embodiment. As described above, the control panel 50 can be pulled forward from the compressor housing 24 together with the second panel portion 29. When the control panel 50 is pulled out, it is pulled forward from the compressor housing 24 along the arrow A. Figure 8 Components of the compressor 12 other than the control panel 50 are omitted.

[0069] A caster fixing portion 52a is provided at the upper surface end of the bottom panel 24d of the compressor frame 24. In this embodiment, the passing area 72 of the control panel 50 when the control panel 50 is pulled forward from the compressor frame 24 together with the second panel portion 29 is defined at a position closer to the inside than the caster fixing portion 52a. In other words, the width (lateral dimension) W1 of the bottom surface of the control panel 50 is narrower than the width W2 of the second panel portion 29. Thus, interference between the control panel 50 and the caster fixing portion 52a can be avoided when the control panel 50 is pulled forward, so that the control panel 50 can be taken out smoothly.

[0070] An exemplary sequence of removing the control panel 50 from the compressor 12 according to the embodiment is as follows. First, the side panels 24e, 24f and the top panel 24c are removed from the compressor frame 24. The fastening between the second panel portion 29 of the front panel 24a and the frame structure 26 and the bottom panel 24d is released. A long tool 64 such as a screwdriver is inserted through the opening 60 of the first panel portion 28 of the front panel 24a to remove the connector 58, thereby releasing the fastening between the first panel portion 28 and the second panel portion 29. In this way, the structural connection between the compressor 12 and the control panel 50 is released.

[0071] Furthermore, it is not necessary to remove the main components of the compressor 12 , such as the compressor body 16 , the oil separator 34 , the adsorber 35 , and the accumulator 36 , which are provided on the bottom panel 24 d .

[0072] Next, the electrical connection between the compressor 12 and the control board 50 is released. The electrical wiring connected to the plurality of connectors 66 on the back of the control board 50 is removed. These wirings are also removed from the fixings 68 on the back of the control board 50. Furthermore, the cable connecting the compressor body 16 and the control board 50 is also removed.

[0073] Then, the second panel portion 29 and the control board 50 are pulled out from the compressor housing 24 in the direction of arrow A. Thus, the control board 50 can be removed from the compressor 12 together with the second panel portion 29. The removed control board 50 can be repaired, replaced, or other maintenance work.

[0074] As described at the beginning of this specification, in the previous ultra-low temperature refrigerator compressor, typically, a single panel is used on the front of the compressor frame. The refrigerant gas supply piping and recovery piping of the cold head will be connected to the single front panel. Moreover, the coolant supply piping and recovery piping of the heat exchanger provided in the compressor frame for cooling the compressor will also be connected to the front panel. The control panel of the compressor will be arranged behind the front panel in the compressor frame. In the compressor of this design, when removing the control panel, the operator first removes the front panel from the compressor frame. However, in order to remove the front panel, it is necessary to extract the refrigerant gas from the refrigerant gas piping and the coolant from the coolant piping before removing these pipings from the front panel. In addition, other compressor components such as adsorbers are sometimes fastened to the front panel, and at this time, it is also necessary to remove these components from the front panel in advance. Therefore, in the previous design, the disassembly operation of removing the control panel from the compressor requires a pre-process of decomposing the compressor into each component, so it takes a lot of time.

[0075] In contrast, according to the embodiment, the first panel portion 28 of the front panel 24a is provided with a piping connection, and the control panel 50 is mounted on the second panel portion 29. Thus, in a state where the piping of the refrigerant gas and the cooling liquid is connected to the first panel portion 28, the second panel portion 29 can be removed without removing the first panel portion 28 from the compressor frame 24. In the disassembly operation of the control panel 50, it is not necessary to disassemble the piping. The disassembly operation of the control panel 50 in the compressor 12 for the ultra-low temperature refrigerator 10 can be easily performed.

[0076] Furthermore, the first panel portion 28 is provided with an opening 60 that allows access to the coupling member 58 from the outside of the compressor frame 24. Thus, the tool 64 can reach the coupling member 58 from the outside of the compressor frame 24 to release the connection between the first panel portion 28 and the second panel portion 29 without disassembling various devices such as the adsorber 35 provided in the compressor frame 24. This also helps to facilitate the disassembly operation of the control panel 50.

[0077] A plurality of connectors 66 connected to a plurality of electrical installation components are provided on the back of the control panel 50. Preferably, the plurality of connectors 66 are collectively arranged at a specific position on the back of the control panel 50. Thus, by removing the wiring from the connectors 66, the connection between the control panel 50 and the electrical installation components can be released.

[0078] The control panel 50 can be pulled forward from the compressor housing 24 together with the second panel portion 29. The passage area 72 of the control panel 50 is defined inside the caster fixing portion 52a. Thus, the control panel 50 can be pulled forward without interfering with the caster fixing portion 52a.

[0079] The present invention is described above based on the embodiments. Those skilled in the art should understand that the present invention is not limited to the above-mentioned embodiments, and various design changes and variations may exist, and such variations are also within the scope of the present invention. Various features described in one embodiment may also be applicable to other embodiments. The new embodiment generated by the combination has the effects of the combined embodiments.

[0080] In the above-mentioned embodiment, the front panel 24a is formed by two panel parts adjacent to each other on the left and right, but the front panel 24a may also adopt other structures. For example, the front panel 24a may be formed by two panel parts adjacent to each other in the upper and lower parts. At this time, the first panel part 28 and the second panel part 29 may be in a horizontally long shape with a total length equivalent to the horizontal width of the compressor 12, and may be adjacent to each other in the upper and lower parts when viewed from the front. The first panel part 28 (or the second panel part 29) may be equivalent to the upper half of the front panel 24a, and the second panel part 29 (or the first panel part 28) may be equivalent to the lower half of the front panel 24a.

[0081] The front panel 24a may be divided into three or more panel parts including the first panel part 28 and the second panel part 29. These panel parts may be connected to each other to constitute the front panel 24a.

[0082] The present invention has been described above based on the implementation method and using specific terms, but the implementation method only shows one aspect of the principle and application of the present invention. Without departing from the scope of the idea of ​​the present invention specified in the technical solution, the implementation method allows for a variety of modifications and configuration changes.

Claims

1. A compressor for a cryogenic refrigerator, characterized in that: have: control panel; and The compressor frame has a front panel and accommodates the control panel. The front panel includes: a first panel portion for providing piping connection; and a second panel portion detachably connected to the first panel portion and carrying the control board.

2. The compressor for a cryogenic refrigerator according to claim 1, characterized in that: The second panel portion is detachably connected to the first panel portion via a connecting member. The first panel portion has an opening that allows access to the coupling member from outside the compressor housing.

3. The compressor for ultra-low temperature refrigerator according to claim 2, characterized in that: The first panel portion includes a first panel side surface to which the connector is mounted and a second panel side surface having the opening.

4. The compressor for a cryogenic refrigerator according to claim 1, characterized in that: The control panel can be pulled out forward from the compressor housing together with the second panel portion.

5. The compressor for a cryogenic refrigerator according to claim 4, characterized in that: The compressor frame includes a bottom panel, and the caster fixing portion is provided at an upper surface end portion of the bottom panel. When the control panel is pulled forward from the compressor housing together with the second panel portion, a passage area of ​​the control panel is defined on the inner side of the caster fixing portion.

6. The compressor for a cryogenic refrigerator according to any one of claims 1 to 5, characterized in that: The compressor further comprises a plurality of electrical components, wherein the plurality of electrical components are accommodated in the compressor frame. A plurality of connectors connected to the plurality of electrical components are provided on the rear surface of the control panel.

7. The compressor for a cryogenic refrigerator according to claim 6, characterized in that: The plurality of connectors are collectively arranged at specific locations on the rear surface of the control board.

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