Patent Description:
In general, a cryocooler such as a Gifford-McMahon (GM) cryocooler includes a compressor of a refrigerant gas to supply a high-pressure refrigerant gas to a cold head. The compressor includes components such as a compressor main body, an oil separator, an adsorber, a storage tank, and a control device (for example, <CIT>).

Document <CIT> discloses another known cryocooler compressor.

In an existing cryocooler compressor, a pipe for supplying a refrigerant gas to a cold head and a pipe for collecting the refrigerant gas from the cold head can be connected to a front panel of a compressor casing. In addition, a pipe for supplying a coolant to a heat exchanger installed in the compressor casing to cool the compressor and a pipe for collecting the coolant from the heat exchanger can also be connected to the front panel. A control panel of the compressor can be disposed behind the front panel in the compressor casing.

In the compressor with such a casing design, when a worker removes the control panel, the worker first removes the front panel from the compressor casing. However, in order to remove the front panel, it is necessary to discharge the refrigerant gas from the pipe for the refrigerant gas and to discharge the coolant from the pipe for the coolant, and then to remove these pipes from the front panel. In addition, another compressor component such as an adsorber may be fastened to the front panel, and in this case, it is necessary to remove the other compressor component beforehand from the front panel. Therefore, in the existing design, the work of removing the control panel from the compressor requires a preliminary process such as disassembling the compressor into individual parts, which is quite laborious.

The object of the present invention is to facilitate work of removing a control panel in a cryocooler compressor.

According to the present invention, there is provided a cryocooler compressor including a control panel, and a compressor casing that includes a front panel and accommodates the control panel. The front panel includes a first panel portion that provides a pipe connection, and a second panel portion that is removably connected to the first panel portion and on which the control panel is mounted.

According to the present invention, it is possible to facilitate work of removing the control panel in the cryocooler compressor.

Hereinafter, an embodiment for carrying out the present invention will be described in detail with reference to the drawings. In the description and the drawings, the same or equivalent components, members, and processes are denoted by the same reference numerals, and overlapping description is omitted as appropriate. The scale and the shape of each of parts shown in the drawings are set for convenience to make the description easy to understand, and are not to be interpreted as limiting unless stated otherwise. The embodiment is merely an example and does not limit the scope of the present invention. All features described in the embodiment or combinations thereof are not necessarily essential to the present invention.

<FIG> is a diagram schematically showing a cryocooler <NUM> according to the embodiment. The cryocooler <NUM> is used to provide cryogenic cooling to an object or a medium. For example, the cryocooler <NUM> may be used as a cooling source for a superconducting magnet device. The superconducting magnet device is mounted on, for example, a high magnetic field using device as a magnetic field source of an accelerator such as a single crystal pulling device, a nuclear magnetic resonance (NMR) system, a magnetic resonance imaging (MRI) system, and a cyclotron, a high energy physical system such as a nuclear fusion system, or other high magnetic field using devices (not shown) and can generate a high magnetic field required for the devices.

The cryocooler <NUM> includes a compressor <NUM> and a cold head <NUM>. The compressor <NUM> is configured to collect a refrigerant gas of the cryocooler <NUM> from the cold head <NUM>, to pressurize the collected refrigerant gas, and to supply the refrigerant gas to the cold head <NUM> again. The compressor <NUM> is also referred to as a compressor unit. The cold head <NUM> is also referred to as an expander and includes a room temperature section 14a and a low-temperature section 14b which is also referred to as a cooling stage. The refrigerant gas is also referred to as a working gas, and other suitable gases may be used although a helium gas is typically used. The compressor <NUM> and the cold head <NUM> constitute a refrigeration cycle of the cryocooler <NUM>, whereby the low-temperature section 14b is cooled to a desired cryogenic temperature. The low-temperature section 14b can cool an object to be cooled such as a superconducting magnet.

Although the cryocooler <NUM> is, for example, a single-stage or two-stage Gifford-McMahon (GM) cryocooler, the cryocooler <NUM> may be a pulse tube cryocooler, a Stirling cryocooler, or other types of cryocoolers. Although the cold head <NUM> has a different configuration depending on the type of the cryocooler <NUM>, the compressor <NUM> can use a configuration described below regardless of the type of the cryocooler <NUM>.

In general, both a pressure of a refrigerant gas supplied from the compressor <NUM> to the cold head <NUM> and a pressure of a refrigerant gas collected from the cold head <NUM> to the compressor <NUM> are considerably higher than the atmospheric pressure, and can be called a first high pressure and a second high pressure, respectively. For convenience of description, the first high pressure and the second high pressure are also simply called a high pressure and a low pressure, respectively. Typically, the high pressure is, for example, <NUM> to <NUM> MPa. The low pressure is, for example, <NUM> to <NUM> MPa and is, for example, about <NUM> MPa.

The compressor <NUM> is an oil-lubricated cryocooler compressor, and includes a compressor main body <NUM>, a refrigerant gas line <NUM>, and an oil circulation line <NUM>. In <FIG>, in order to facilitate understanding, the refrigerant gas line <NUM> is shown by a solid line, and the oil circulation line <NUM> is shown by a broken line. In addition, the compressor <NUM> includes a compressor casing <NUM> that accommodates each component of the compressor <NUM>, such as the compressor main body <NUM>, the refrigerant gas line <NUM>, and the oil circulation line <NUM>.

The compressor main body <NUM> is configured to internally compress a refrigerant gas sucked from a suction port of the compressor main body <NUM> and to discharge the refrigerant gas from a discharge port. An oil is used in the compressor main body <NUM> for the sake of cooling and lubrication, and the sucked refrigerant gas is directly exposed to the oil in the compressor main body <NUM>. Accordingly, the refrigerant gas is delivered from the discharge port in a state where the oil is slightly mixed.

The compressor main body <NUM> may be, for example, a scroll type pump, a rotary type pump, or other pumps that pressurize a refrigerant gas. The compressor main body <NUM> may be configured to discharge the refrigerant gas at a fixed and constant flow rate. Alternatively, the compressor main body <NUM> may be configured to vary the flow rate of the refrigerant gas to be discharged. The compressor main body <NUM> may be called a compression capsule.

The refrigerant gas line <NUM> includes a discharge port <NUM>, a suction port <NUM>, a discharge flow path <NUM>, and a suction flow path <NUM>. The discharge port <NUM> is an outlet of a refrigerant gas that is installed in the compressor casing <NUM> in order to deliver the refrigerant gas, which is pressurized to a high pressure by the compressor main body <NUM>, from the compressor <NUM>, and the suction port <NUM> is an inlet of the refrigerant gas that is installed in the compressor casing <NUM> in order for the compressor <NUM> to receive a low-pressure refrigerant gas. The compressor casing <NUM> accommodates the discharge flow path <NUM> and the suction flow path <NUM>. The discharge port of the compressor main body <NUM> is connected to the discharge port <NUM> by the discharge flow path <NUM>, and the suction port <NUM> is connected to the suction port of the compressor main body <NUM> by the suction flow path <NUM>.

The refrigerant gas line <NUM> is connected to the cold head <NUM>. A high-pressure port <NUM> and a low-pressure port <NUM> are provided in the room temperature section 14a of the cold head <NUM>. The high-pressure port <NUM> is connected to the discharge port <NUM> by a high-pressure pipe <NUM>, and the low-pressure port <NUM> is connected to the suction port <NUM> by a low-pressure pipe <NUM>.

The oil separator <NUM> and the adsorber <NUM> are provided in the discharge flow path <NUM>. The oil separator <NUM> is provided in order to separate an oil, which is mixed in a refrigerant gas as passing through the compressor main body <NUM>, out from the refrigerant gas. The adsorber <NUM> is provided in order to remove, for example, a vaporized oil and other contaminants remaining in the refrigerant gas from the refrigerant gas through adsorption. The oil separator <NUM> and the adsorber <NUM> are connected in series. In the discharge flow path <NUM>, the oil separator <NUM> is disposed on the compressor main body <NUM> side, and the adsorber <NUM> is disposed on the discharge port <NUM> side.

An oil return line <NUM> that connects the oil separator <NUM> to the compressor main body <NUM> is provided. An oil collected by the oil separator <NUM> can be returned to the compressor main body <NUM> through the oil return line <NUM>. In the middle of the oil return line <NUM>, a filter that removes dust included in the oil separated out by the oil separator <NUM> and an orifice that controls the amount of the oil returning to the compressor main body <NUM> may be provided.

On the other hand, a storage tank <NUM> is provided at the suction flow path <NUM>. The storage tank <NUM> is provided as a volume for removing pulsation included in a low-pressure refrigerant gas returning from the cold head <NUM> to the compressor <NUM>.

In addition, a bypass valve <NUM> that connects the discharge flow path <NUM> to the suction flow path <NUM> to bypass the compressor main body <NUM> is provided at the refrigerant gas line <NUM>. For example, the bypass valve <NUM> branches off from the discharge flow path <NUM> between the oil separator <NUM> and the adsorber <NUM> and is connected to the suction flow path <NUM> between the compressor main body <NUM> and the storage tank <NUM>. The bypass valve <NUM> is provided in order to control a flow rate of a refrigerant gas and/or in order to equalize the discharge flow path <NUM> and the suction flow path <NUM> when the compressor <NUM> is stopped.

The oil circulation line <NUM> connects an oil outlet to an oil inlet of the compressor main body <NUM> in order to return the oil flowing out from the compressor main body <NUM> to the compressor main body <NUM> again. The oil circulation line <NUM> may be provided with an orifice that controls a flow rate of an oil flowing therein. In addition, a filter that removes dust included in the oil may be provided at the oil circulation line <NUM>.

In addition, the compressor <NUM> further includes a heat exchanger <NUM> that is accommodated in the compressor casing <NUM> and cools the compressor <NUM>. The heat exchanger <NUM> includes a refrigerant gas cooler 22a that cools the refrigerant gas line <NUM> through heat exchange between the refrigerant gas and a cooling medium, and an oil cooler 22b that cools the oil circulation line <NUM> through heat exchange between the oil and the cooling medium.

The refrigerant gas cooler 22a is disposed between the compressor main body <NUM> and the oil separator <NUM> in the discharge flow path <NUM>, and cools a high-pressure refrigerant gas heated by compression heat generated with the compression of the refrigerant gas in the compressor main body <NUM>. The refrigerant gas cooler 22a cools the refrigerant gas through heat exchange between the refrigerant gas and the cooling medium. The cooled refrigerant gas is purified by the oil separator <NUM> and the adsorber <NUM>. In addition, the oil cooler 22b cools the oil through heat exchange between the oil flowing out from the oil outlet of the compressor main body <NUM> to the oil circulation line <NUM> and the cooling medium. The cooled oil is returned into the compressor main body <NUM> from the oil inlet of the compressor main body <NUM>. The cooling medium is supplied from the outside to the compressor <NUM> through a cooling medium intake <NUM>, and is discharged to the outside of the compressor <NUM> from a cooling medium discharge port <NUM> via the refrigerant gas cooler 22a and the oil cooler 22b. The cooling medium may be a coolant, for example, water. In this manner, compression heat generated by the compressor main body <NUM> is removed to the outside of the compressor <NUM> together with the cooling medium. The cooling medium may be cooled by, for example, a chiller (not shown) and may be supplied again.

In this embodiment, the heat exchanger <NUM> is a double pipe-type heat exchanger. Therefore, the heat exchanger <NUM> includes 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, a fluid to be cooled is supplied to the other. Accordingly, heat exchange between the cooling medium and the target fluid is performed, and the fluid can be cooled. For example, in the refrigerant gas cooler 22a, cooling water may be supplied to the outer tube, and the refrigerant gas may be supplied to the inner tube. In the oil cooler 22b, cooling water may be supplied to the outer tube, and oil may be supplied to the inner tube.

During an operation of the cryocooler <NUM>, a refrigerant gas is supplied from the compressor <NUM> to the cold head <NUM>, a refrigeration cycle (for example, a GM cycle) is configured by a periodic volume fluctuation of an expansion space of the refrigerant gas in the cold head <NUM> and a pressure fluctuation of the refrigerant gas in the expansion space synchronized with the periodic volume fluctuation, and the low-temperature section 14b of the cold head <NUM> is cooled to a desired cryogenic temperature. In a case where the cold head <NUM> is, for example, a two-stage type, a first-stage cooling stage is cooled to a first cooling temperature in a range of, for example, about <NUM> to about <NUM>, and a second-stage cooling stage is cooled to a second cooling temperature lower than the first cooling temperature, for example, <NUM> to <NUM>. The second cooling temperature may be a liquid helium temperature of about <NUM> or a temperature lower than the liquid helium temperature.

A refrigerant gas collected from the cold head <NUM> to the compressor <NUM> flows into the suction port <NUM> of the compressor <NUM> from the low-pressure port <NUM> through the low-pressure pipe <NUM>. The refrigerant gas is collected to the suction port of the compressor main body <NUM> via the storage tank <NUM> on the suction flow path <NUM>. The refrigerant gas is compressed and pressurized by the compressor main body <NUM>. In this case, a temperature of the refrigerant gas is raised by compression heat. The refrigerant gas delivered from the discharge port of the compressor main body <NUM> is cooled by the refrigerant gas cooler 22a of the heat exchanger <NUM>, and exits the compressor <NUM> from the discharge port <NUM> via the oil separator <NUM> and the adsorber <NUM>. The refrigerant gas is supplied into the cold head <NUM> via the high-pressure pipe <NUM> and the high-pressure port <NUM>.

<FIG> is a schematic perspective view showing an appearance of the compressor <NUM> according to the embodiment. <FIG> and <FIG> are schematic perspective views showing the disposition of the devices inside the compressor <NUM> according to the embodiment. <FIG> and <FIG> are perspective views of the compressor <NUM> seen from a front side, and <FIG> is a perspective view of the compressor <NUM> seen from a rear side. <FIG> and <FIG> show a state in which some panels of the compressor casing <NUM> are removed in order to show the disposition of the internal devices of the compressor <NUM>.

As shown in <FIG>, the compressor casing <NUM> of the compressor <NUM> has a rectangular parallelepiped shape having six surfaces, and includes a front panel 24a, a back panel 24b, an upper panel 24c, a bottom panel 24d, and two side panels 24e and 24f on left and right sides. The back panel 24b faces an opposite side of the front panel 24a. Between the front panel 24a and the back panel 24b, the upper panel 24c is disposed above, the bottom panel 24d is disposed below, and the side panels 24e and 24f are disposed on the left and right sides.

The front panel 24a includes two panel portions combined with each other to form the front panel 24a, specifically, a first panel portion <NUM> and a second panel portion <NUM>. The first panel portion <NUM> provides a pipe connection, and the second panel portion <NUM> provides a user interface and an electrical connection. As will be described below with reference to <FIG>, the second panel portion <NUM> is removably connected to the first panel portion <NUM>.

The first panel portion <NUM> and the second panel portion <NUM> have a vertically elongated shape having a total length corresponding to a height of the compressor <NUM>, and are adjacent to each other in a left-right direction in front view. The first panel portion <NUM> corresponds to the right half of the front panel 24a, and the second panel portion <NUM> corresponds to the left half of the front panel 24a. The panel portions are thin plate-shaped members formed of a metal such as stainless steel or other appropriate materials.

As shown in <FIG> and <FIG>, the first panel portion <NUM> is provided with the discharge port <NUM>, the suction port <NUM>, the cooling medium intake <NUM>, and the cooling medium discharge port <NUM>. In this way, the outlet and the inlet of the fluid such as the refrigerant gas in the compressor <NUM> are concentrated in the first panel portion <NUM>. The second panel portion <NUM> is not provided with such outlet and inlet of the fluid.

An operation panel <NUM> for receiving an input for controlling the cryocooler <NUM> from a user of the cryocooler <NUM> and/or for displaying information regarding the cryocooler <NUM> is provided on a front surface (surface facing the outside of the compressor casing <NUM>) of the second panel portion <NUM>.

In addition, a power breaker <NUM> and a cold head connector <NUM> are provided on the front surface of the second panel portion <NUM>. The power breaker <NUM> is connected to an external power source such as a commercial power source, whereby the cryocooler <NUM> is supplied with power. An electric wire for supplying power from the compressor <NUM> to the cold head <NUM> and for controlling the cold head <NUM> by the control panel <NUM> is connected to the cold head connector <NUM>. An electrical connection between the compressor <NUM> and the cold head <NUM> is established by the electric wire.

A main switch <NUM> is provided in the power breaker <NUM>. The main switch <NUM> is a switch for switching on and off the cryocooler <NUM>. When the main switch <NUM> is turned on, the compressor <NUM> and the cold head <NUM> are operated, and when the main switch <NUM> is turned off, the operation of the compressor <NUM> and the cold head <NUM> is stopped.

The control panel <NUM> is mounted on the second panel portion <NUM>. The control panel <NUM> is attached to a back surface (surface facing the inside of the compressor casing <NUM>) of the second panel portion <NUM>, and is accommodated in the compressor casing <NUM>. Although details will be described below, as shown by an arrow A in <FIG> and <FIG>, the control panel <NUM> can be extracted forward from the compressor casing <NUM> together with the second panel portion <NUM>.

The control panel <NUM> is a control device that controls the compressor <NUM>. The control panel <NUM> may include a control circuit configured to receive an output from various sensors provided in the cryocooler <NUM> and to control various devices of the cryocooler <NUM> based on the sensor output. A plurality of electric components including sensors such as a temperature sensor and a pressure sensor may be accommodated in the compressor casing <NUM>. Each sensor may be connected to the control panel <NUM> by a communication cable.

The temperature sensor may include a refrigerant gas temperature sensor provided in the refrigerant gas line <NUM>, an oil temperature sensor provided in the oil circulation line <NUM>, a coolant temperature sensor provided in a coolant pipe of the heat exchanger <NUM>, a cooling temperature sensor provided in the low-temperature section 14b of the cold head <NUM>, or the like.

For example, as shown in <FIG>, a first temperature sensor <NUM> is provided upstream of the heat exchanger <NUM> on the discharge flow path <NUM> of the refrigerant gas line <NUM>, and measures a temperature of the refrigerant gas flowing into the heat exchanger <NUM> from the compressor main body <NUM>. A second temperature sensor <NUM> is provided downstream of the heat exchanger <NUM> on the refrigerant gas line <NUM>, and measures a temperature of the refrigerant gas flowing into the oil separator <NUM> from the heat exchanger <NUM>. A third temperature sensor <NUM> is provided upstream of the heat exchanger <NUM> on the oil circulation line <NUM>, and measures a temperature of the oil flowing into the heat exchanger <NUM> from the compressor main body <NUM>. A fourth temperature sensor <NUM> is provided downstream of the heat exchanger <NUM> on the oil circulation line <NUM>, and measures a temperature of the oil flowing into the compressor main body <NUM> from the heat exchanger <NUM>. The temperature sensor is configured to output a signal representing the measured temperature to the control panel <NUM>. The temperature sensor may be, for example, a thermistor. The temperature sensor may be mounted on an outer surface of the pipe constituting the refrigerant gas line <NUM> and the oil circulation line <NUM>.

In addition, a first pressure sensor 37a may be disposed in the discharge flow path <NUM> to measure a pressure of the refrigerant gas flowing through the discharge flow path <NUM>. The first pressure sensor 37a is configured to output a first measured pressure signal PH representing the measured pressure to the control panel <NUM>. A second pressure sensor 37b is disposed in the suction flow path <NUM> to measure a pressure of the refrigerant gas flowing through the suction flow path <NUM>. The second pressure sensor 37b is configured to output a second measured pressure signal PL indicating the measured pressure to the control panel <NUM>.

The electric component controlled based on the sensor output may include, for example, a compressor motor that drives the compressor main body <NUM>, the bypass valve <NUM>, and a cold head motor that drives the cold head <NUM>. The control panel <NUM> may include a compressor inverter for controlling a rotation speed of the compressor motor and/or a cold head inverter for controlling a rotation speed of the cold head motor.

Referring again to <FIG>, casters <NUM> are attached to the bottom panel 24d in order to facilitate the movement and the transportation of the compressor <NUM>. Four casters <NUM> are respectively provided at four corners of the bottom panel 24d. As shown in <FIG> and <FIG>, in order to fix the casters <NUM> to the bottom panel 24d, a caster fixation portion 52a is provided at an upper surface end portion of the bottom panel 24d for each of the casters <NUM>. As an example, the caster fixation portion 52a may include a nut for fixing the caster <NUM> to the bottom panel 24d. The caster <NUM> is provided with a bolt portion extending upward from the caster <NUM>, and the bolt portion extends above the bottom panel 24d through a receiving hole penetrating the bottom panel 24d and is fixed to the bottom panel 24d by the nut.

As shown in <FIG> and <FIG>, the compressor casing <NUM> includes a frame structure <NUM> that supports the above-described panels and is responsible for structural strength. The panels are removably attached to the frame structure <NUM>. In a state where the panels are attached to the frame structure <NUM>, the devices inside the compressor <NUM> are covered and hidden by the panels as shown in <FIG>. The panels may be attached to the frame structure <NUM> by an appropriate method such as screwing. In a state where the panels are removed from the frame structure <NUM>, the user or the worker can easily access the devices inside the compressor <NUM> from an opening portion of the frame structure <NUM>, and can efficiently perform maintenance work or manufacturing work of the compressor <NUM>.

For example, on a back surface of the compressor casing <NUM>, a rectangular back outer frame 26a that is provided to surround the back surface and that configures a part of the frame structure <NUM> is provided. Each of four sides of the rectangular shape of the back panel 24b is removably attached to the back outer frame 26a. Both ends of an upper part of the back outer frame 26a are connected to both ends of an upper edge of the front panel 24a by two side frames 26b, and a lower part of the back outer frame 26a is connected to a rear edge of the bottom panel 24d. In addition, a lower edge of the front panel 24a is connected to a front edge of the bottom panel 24d. Four sides of the upper panel 24c are removably attached to upper parts of the back outer frame 26a and the front panel 24a and the two side frames 26b. Four sides of the side panel 24e are removably attached to side portions of the back outer frame 26a and the first panel portion <NUM>, the side frame 26b, and the bottom panel 24d. Four sides of the side panel 24f are removably attached to side portions of the back outer frame 26a and the second panel portion <NUM>, the side frame 26b, and the bottom panel 24d.

In the existing compressor, a design is adopted in which a panel itself forming each surface of the compressor casing is responsible for structural strength, so that a plate thickness of the panel is large, and a weight thereof tends to be large. Therefore, the work of attaching the panel in the manufacturing process or the work of removing the panel in the maintenance work is not easy, which is one of causes of a decrease in workability for the worker. On the other hand, according to the embodiment, the compressor casing <NUM> includes the frame structure <NUM> that is responsible for structural strength, so that each panel such as the back panel 24b attached to the frame structure <NUM> can be thinned and weight-saved. Such a casing structure is also useful in improving workability.

As described above, the main components of the compressor <NUM>, such as the compressor main body <NUM>, the heat exchanger <NUM>, the oil separator <NUM>, the adsorber <NUM>, the storage tank <NUM>, and the control panel <NUM>, are accommodated in the compressor casing <NUM>. The oil separator <NUM>, the adsorber <NUM>, and the storage tank <NUM> are installed on the bottom panel 24d close to one side panel 24e, and are disposed in the compressor casing <NUM>. The adsorber <NUM>, the storage tank <NUM>, and the oil separator <NUM> are arranged in this order from the first panel portion <NUM> of the front panel 24a toward the back panel 24b. In addition, the compressor main body <NUM> and the control panel <NUM> are disposed in the compressor casing <NUM> close to the other side panel 24f. As described above, the control panel <NUM> is attached to the second panel portion <NUM> of the front panel 24a, and the compressor main body <NUM> is installed on the bottom panel 24d between the control panel <NUM> and the back panel 24b.

As shown in <FIG>, the heat exchanger <NUM> is disposed in a state of being bent in a spiral shape along the back surface of the compressor casing <NUM>. Accordingly, the double pipe of the heat exchanger <NUM> having a relatively long total length can be made compact and disposed in a space-saving manner. In addition, the spiral shape of the heat exchanger <NUM> is formed to leave a space at a center portion of the back surface of the compressor casing <NUM>. That is, an internal access opening portion <NUM> in which the heat exchanger <NUM> is not disposed is formed in the center portion of the back surface of the compressor casing <NUM>. In the manufacturing process of the compressor <NUM> or in maintenance work of the compressor <NUM> at a site where the compressor <NUM> is used, the worker can easily access the devices inside the compressor <NUM> from the internal access opening portion <NUM>. For example, the manufacturing work such as pipe welding and joint fastening and various kinds of maintenance work (for example, replacement of consumables such as filters and replacement and repair of devices such as failed sensors) can be performed through the internal access opening portion <NUM>.

<FIG> is a plan view schematically showing a part of the front panel 24a according to the embodiment. In addition, <FIG> is a side view schematically showing a part of the front panel 24a according to the embodiment.

As described above, the front panel 24a includes the first panel portion <NUM> and the second panel portion <NUM> that are removably connected to each other. <FIG> shows a back surface upper part of these two panel portions. <FIG> shows a state in which the remaining portions of the compressor casing <NUM>, such as the frame structure <NUM> and the upper panel 24c, are removed from the front panel 24a, and the control panel <NUM> is removed from the second panel portion <NUM>.

The first panel portion <NUM> and the second panel portion <NUM> are removably connected to each other by a connecting tool <NUM>. For example, the connecting tool <NUM> may be a screw, a fastening part such as a bolt and a nut, or other appropriate removable connecting parts. The first panel portion <NUM> includes a first panel side surface 28a and a second panel side surface 28b, and the second panel portion <NUM> includes a first panel side surface 29a and a second panel side surface 29b. The first panel side surface 28a of the first panel portion <NUM> and the first panel side surface 29a of the second panel portion <NUM> are in contact with each other and are connected to each other by the connecting tool <NUM>. In this embodiment, since the first panel portion <NUM> and the second panel portion <NUM> have a vertically elongated shape, the first panel portion <NUM> and the second panel portion <NUM> may be connected to each other by a plurality of the connecting tools <NUM>, for example, three connecting tools <NUM> along a longitudinal direction thereof.

The second panel side surface 28b of the first panel portion <NUM> is a side surface on a side opposite to the first panel side surface 28a, and faces the side panel 24e side shown in <FIG>. The second panel side surface 29b of the second panel portion <NUM> is a side surface on a side opposite to the first panel side surface 29a, and faces the side panel 24f side shown in <FIG>.

The first panel portion <NUM> includes an opening portion <NUM> for enabling access to the connecting tool <NUM> from the outside of the compressor casing <NUM>. Specifically, the opening portion <NUM> is provided on the second panel side surface 28b of the first panel portion <NUM>. A plurality of the opening portions <NUM> may be provided on the second panel side surface 28b to correspond to the plurality of connecting tools <NUM>. Since the connecting tool <NUM> and the opening portion <NUM> are provided at the same position in the longitudinal direction (that is, a height direction) of the panel, the opening portion <NUM> functions as a peephole, so to speak.

<FIG> shows the opening portion <NUM> and the vicinity thereof in the second panel side surface 28b of the first panel portion <NUM>. When peeping through the opening portion <NUM> from the outside of the compressor casing <NUM>, as shown in the figure, the connecting tool <NUM> can be visually recognized in the opening portion <NUM>. In this example, a diameter of the opening portion <NUM> is slightly larger than a diameter of the connecting tool <NUM>, and the entire head portion of the connecting tool <NUM> is visible through the opening portion <NUM>.

Therefore, it is possible to access the connecting tool <NUM> from the outside of the compressor casing <NUM> by using the opening portion <NUM>. As shown in <FIG>, a tool <NUM> having a length compatible with a width (dimension in the horizontal direction in <FIG>) of the first panel portion <NUM> can be inserted from the opening portion <NUM> into the compressor casing <NUM> and can reach the connecting tool <NUM>. In a case where the connecting tool <NUM> is a screw, the tool <NUM> may be, for example, a driver. In this way, the connecting tool <NUM> can be operated by using the opening portion <NUM> and the tool <NUM> to connect or disconnect the first panel portion <NUM> and the second panel portion <NUM>.

As described above, the compressor <NUM> includes various electric components such as various sensors (for example, the pressure sensors 37a and 37b and the temperature sensors <NUM> to <NUM>) and the bypass valve <NUM>. The electric component is accommodated in the compressor casing <NUM> and is connected to the control panel <NUM>. As shown in <FIG> and <FIG>, the control panel <NUM> includes a plurality of connectors <NUM> in order to electrically connect the electric component and the control panel <NUM> to each other. A connector of an electric wire (not shown) extending from the electric component is connected to the connectors <NUM>.

<FIG> is a schematic plan view showing a back surface of the control panel <NUM> according to the embodiment. Referring to <FIG> and <FIG>, the plurality of connectors <NUM> are provided on the back surface of the control panel <NUM>. These connectors may be collectively disposed at a specific location on the back surface of the control panel <NUM>. For example, as shown in the figure, a large number of the connectors <NUM> may be collectively disposed at a location near the outside of the compressor casing <NUM> (for example, a location close to the panel of the compressor casing <NUM>) on the back surface of the control panel <NUM>. In this way, the connectors <NUM> are exposed near the opening portion of the frame structure <NUM> when the panel (for example, the side panel 24f) is removed from the compressor casing <NUM>. The worker can easily access the connectors <NUM> from the outside of the compressor casing <NUM>, and can easily perform the work of connecting (or removing) the electric component to (or from) the connectors <NUM>.

In addition, as shown in the figure, a large number of fasteners <NUM> (for example, tie anchors) for removably fixing electric wires for connecting the electric component to the connectors <NUM> to the control panel <NUM> are provided on the back surface of the control panel <NUM>. The fasteners <NUM> are provided on the back surface of the control panel <NUM> to define a wiring route <NUM> (an example is shown by a broken line in <FIG>). By using the fasteners <NUM>, the electric wires can be organized and disposed on the back surface of the control panel <NUM>.

<FIG> is a schematic top view showing a passage region <NUM> of the control panel <NUM> according to the embodiment. As described above, the control panel <NUM> can be extracted forward from the compressor casing <NUM> together with the second panel portion <NUM>. When the control panel <NUM> is extracted, the control panel <NUM> is extracted forward from the compressor casing <NUM> along an arrow A. In addition, in <FIG>, the components of the compressor <NUM> other than the control panel <NUM> are not shown.

The caster fixation portion 52a is provided at an upper surface end portion of the bottom panel 24d of the compressor casing <NUM>. In this embodiment, the passage region <NUM> of the control panel <NUM> when the control panel <NUM> is extracted forward from the compressor casing <NUM> together with the second panel portion <NUM> is defined inside the caster fixation portion 52a. In other words, a width (dimension in the horizontal direction) W1 of the bottom surface of the control panel <NUM> is narrower than a width W2 of the second panel portion <NUM>. Accordingly, when the control panel <NUM> is extracted forward, interference between the control panel <NUM> and the caster fixation portion 52a can be avoided, and the control panel <NUM> can be smoothly extracted.

An exemplary procedure for removing the compressor <NUM> from the control panel <NUM> according to the embodiment is as follows. First, the side panels 24e and 24f and the upper panel 24c are removed from the compressor casing <NUM>. The fastening between the second panel portion <NUM> of the front panel 24a, and the frame structure <NUM> and the bottom panel 24d is released. The tool <NUM>, which is long, such as a driver is inserted through the opening portion <NUM> of the first panel portion <NUM> of the front panel 24a, the connecting tool <NUM> is removed, and the fastening between the first panel portion <NUM> and the second panel portion <NUM> is released. In this way, the structural connection between the compressor <NUM> and the control panel <NUM> is released.

The main components of the compressor <NUM>, such as the compressor main body <NUM>, the oil separator <NUM>, the adsorber <NUM>, and the storage tank <NUM>, which are installed on the bottom panel 24d, do not need to be removed.

Next, the electrical connection between the compressor <NUM> and the control panel <NUM> is released. The electric wires connected to a large number of the connectors <NUM> on the back surface of the control panel <NUM> are removed. The wires are also removed from the fasteners <NUM> on the back surface of the control panel <NUM>. In addition, an electric cable connecting the compressor main body <NUM> and the control panel <NUM> is also removed.

Then, the second panel portion <NUM> and the control panel <NUM> are pulled out from the compressor casing <NUM> along an arrow A. In this way, the control panel <NUM> can be removed from the compressor <NUM> together with the second panel portion <NUM>. The removed control panel <NUM> can be subjected to the maintenance work such as repair or replacement.

As described at the beginning of the present specification, typically, in the existing compressor for the cryocooler, a single panel is used on the front surface of the compressor casing. A pipe for supplying the refrigerant gas to the cold head and a pipe for collecting the refrigerant gas from the cold head can be connected to the single front panel. In addition, a pipe for supplying the coolant to the heat exchanger installed in the compressor casing to cool the compressor and a pipe for collecting the coolant from the heat exchanger can also be connected to the front panel. The control panel of the compressor can be disposed behind the front panel in the compressor casing. In the compressor with such a design, when the worker removes the control panel, the worker first removes the front panel from the compressor casing. However, in order to remove the front panel, it is necessary to discharge the refrigerant gas from the pipe for the refrigerant gas and to discharge the coolant from the pipe for the coolant, and then to remove these pipes from the front panel. In addition, another compressor component such as an adsorber may be fastened to the front panel, and in this case, it is necessary to remove the other compressor component beforehand from the front panel. Therefore, in the existing design, the work of removing the control panel from the compressor requires a preliminary process such as disassembling the compressor into individual parts, which is quite laborious.

On the other hand, according to the embodiment, the first panel portion <NUM> of the front panel 24a provides the pipe connection, and the control panel <NUM> is mounted on the second panel portion <NUM>. Accordingly, the second panel portion <NUM> can be removed without removing the first panel portion <NUM> from the compressor casing <NUM> in a state where the pipes for the refrigerant gas and the coolant are connected to the first panel portion <NUM>. It is possible to eliminate the need to remove the pipes in the work of removing the control panel <NUM>. It is possible to facilitate the work of removing the control panel <NUM> in the compressor <NUM> for the cryocooler <NUM>.

In addition, the first panel portion <NUM> is provided with the opening portion <NUM> for enabling access to the connecting tool <NUM> from the outside of the compressor casing <NUM>. Accordingly, without removing various devices such as the adsorber <NUM> installed in the compressor casing <NUM>, the tool <NUM> can reach the connecting tool <NUM> from the outside of the compressor casing <NUM>, and the connection between the first panel portion <NUM> and the second panel portion <NUM> can be released. This is also useful to facilitate the work of removing the control panel <NUM>.

The plurality of connectors <NUM> connected to the plurality of electric components are provided on the back surface of the control panel <NUM>. Preferably, the plurality of connectors <NUM> are collectively disposed at a specific location on the back surface of the control panel <NUM>. Accordingly, the connection between the control panel <NUM> and the electric component can be released by removing the wires from the connectors <NUM>.

In addition, the control panel <NUM> can be extracted forward from the compressor casing <NUM> together with the second panel portion <NUM>. The passage region <NUM> of the control panel <NUM> is defined inside the caster fixation portion 52a. Accordingly, the control panel <NUM> can be extracted forward without interfering with the caster fixation portion 52a.

The present invention has been described above based on the examples. It will be understood by those skilled in the art that the present invention is not limited to the embodiment, but it is defined by the appended claims.

In the above-described embodiment, the front panel 24a is formed of two panel portions that are adjacent to each other in the left-right direction, but the front panel 24a may have another configuration. For example, the front panel 24a may be formed of two panel portions that are adjacent to each other in an up-down direction. In this case, the first panel portion <NUM> and the second panel portion <NUM> may have a horizontally elongated shape having a total length corresponding to a width of the compressor <NUM>, and may be adjacent to each other in the up-down direction in front view. The first panel portion <NUM> (or the second panel portion <NUM>) may correspond to the upper half of the front panel 24a, and the second panel portion <NUM> (or the first panel portion <NUM>) may correspond to the lower half of the front panel 24a.

The front panel 24a may be divided into three or more panel portions including the first panel portion <NUM> and the second panel portion <NUM>. The panel portions may be connected to each other to form the front panel 24a.

Claim 1:
A cryocooler compressor (<NUM>) comprising:
a control panel (<NUM>); and
a compressor casing (<NUM>) that includes a front panel (24a) and accommodates the control panel (<NUM>),
wherein the front panel (24a) includes a first panel portion (<NUM>) that provides a pipe connection,
characterized in that the front panel (24a) includes a second panel portion (<NUM>) that is removably connected to the first panel portion (<NUM>) and on which the control panel (<NUM>) is mounted.