JP2016156339A - Control device for vacuum pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device for a vacuum pump capable of preventing dew condensation at starting of the pump, and capable of improving usability.SOLUTION: A control device for a vacuum pump includes a power supply device for driving the vacuum pump, a flow passage of a refrigerant for cooling the power supply device, a refrigerant limit device for limiting inflow of the refrigerant to the flow passage, and a refrigerant control section for limiting inflow of the refrigerant to the flow passage by the refrigerant limit device for prescribed time after starting of supply of electric power to the power supply device. The refrigerant limit device is a three-way valve switched between a supply position allowing the refrigerant to flow into the flow passage and a bypass position shutting inflow of the refrigerant to the flow passage and allowing the refrigerant to flow into a bypass passage, and the refrigerant control section switches the three-way valve to the bypass position for the prescribed time after starting of supply of the electric power to the power supply device, and switches the three-way valve to the supply position when a condition that there is not sign of dew condensation is satisfied after the prescribed time.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a control device for a vacuum pump.

  A vacuum pump used for evacuation of an external apparatus such as a semiconductor manufacturing apparatus includes a pump body and a power supply device that controls the pump body. The power supply device is cooled by a coolant such as cooling water. Normally, the power supply device has a semi-enclosed structure, and the dew point temperature inside the power supply device is the same as the outside of the power supply device, that is, outside air. For this reason, when a power supply device is cooled with a refrigerant | coolant, the part which becomes locally lower than dew point temperature will generate | occur | produce in a power supply device, and there exists a possibility that dew condensation may arise.

  Patent Document 1 describes a turbo molecular pump that includes a first valve that blocks only the inflow of cooling water to a power supply device when external power supply to the power supply device is off. The turbo molecular pump power supply device is configured to cool the power supply device by closing the first valve so that dew condensation can be prevented when the external power supply is on and the temperature is lower than the temperature at which the power supply device is overcooled. Stop the inflow of water.

Japanese Patent No. 4710377

  By the way, in the vacuum pump control device, when the occurrence of dew condensation is detected, a warning is issued and the operation may be stopped. In the turbo molecular pump described in Patent Document 1, since the first valve is opened when the external power supply is on and the temperature of the power supply device is higher than the supercooling temperature, the power supply to the power supply device is started. After that, a warning may be issued at an early stage or the operation may be stopped. For this reason, there was room for improvement in usability.

A control device for a vacuum pump according to a preferred embodiment of the present invention includes a power supply device that drives a vacuum pump, a refrigerant flow path that cools the power supply apparatus, a refrigerant restriction device that restricts the flow of refrigerant into the flow path, and a power supply And a refrigerant control unit that restricts the refrigerant from flowing into the flow path by a refrigerant restriction device for a predetermined time after the supply of electric power to the apparatus is started.
In a more preferred embodiment, the refrigerant restriction device is a three-way valve that is switched between a supply position for allowing the refrigerant to flow into the flow path and a bypass position for blocking the flow of the refrigerant into the flow path and allowing the refrigerant to flow into the bypass. The refrigerant control unit switches the three-way valve to the detour position for a predetermined time after starting the supply of power to the power supply device, and when the condition that there is no sign of condensation after the predetermined time has been satisfied Switch the three-way valve to the supply position.

  According to the present invention, usability can be improved.

The figure which shows the turbo-molecular pump which concerns on 1st Embodiment. The schematic diagram which shows the position of the temperature sensor and humidity sensor in the power supply device which concerns on 1st Embodiment. The functional block diagram which shows the structure of a turbo-molecular pump. The figure showing a saturated vapor pressure curve. The flowchart which showed the operation | movement of the solenoid valve switching process which concerns on 1st Embodiment. The flowchart which showed the operation | movement of the dew condensation sign determination process which concerns on 1st Embodiment. The schematic diagram which shows the position of the temperature sensor and humidity sensor in the power supply device which concerns on 2nd Embodiment. The flowchart which showed the operation | movement of the dew condensation sign determination process which concerns on 2nd Embodiment. The flowchart which showed the operation | movement of the dew condensation sign determination process which concerns on 3rd Embodiment.

Hereinafter, an embodiment of a vacuum pump will be described with reference to the drawings.
-First embodiment-
FIG. 1 is a diagram illustrating a turbo molecular pump 1 that is an example of a vacuum pump. For convenience of explanation, in this specification, the vertical direction is defined as shown in FIG.

  The turbo molecular pump 1 includes a pump body 10 and a pump control device. The pump control device includes a power supply device 40 that drives and controls the pump main body 10, and a cooling device 50 that is disposed between the pump main body 10 and the power supply device 40. By fixing the inlet flange 11 provided in the pump body 10 to a vacuum chamber of an external device (not shown) such as a semiconductor manufacturing device, a liquid crystal panel manufacturing device, or an analyzer, the turbo molecular pump 1 is connected to an external device (not shown). ). Inside the pump main body 10 are accommodated a rotating body (not shown) in which rotating blades are formed, and a motor (not shown in FIG. 1) that rotationally drives the rotating body. The rotating body is supported in a non-contact manner by an electromagnet constituting a magnetic bearing (not shown in FIG. 1).

  The pump body 10 includes a pump casing having an upper casing 20 and a lower casing 30 attached to the lower side of the upper casing 20. The upper casing 20 and the lower casing 30 are combined and integrated by fastening both flanges 21 and 31 with bolts.

  The flange 32 provided at the lower end of the lower casing 30 is fixed to the cooling block 51 of the cooling device 50 with bolts, whereby the lower casing 30 and the cooling block 51 are coupled and integrated. The casing 41 of the power supply device 40 is coupled to the cooling block 51 with bolts and integrated. The casing 41 is formed in a substantially rectangular box shape having an opening at the top, and the opening at the top is closed by a cooling block 51. The housing 41 is configured to communicate with the outside, but has a semi-hermetic structure in which intrusion of liquid droplets and dust is prevented.

  The cooling device 50 is a device that cools both the pump body 10 and the power supply device 40. The cooling device 50 includes a cooling block 51, a cooling pipe 52 that forms a flow path into which the refrigerant flows, and a three-way valve 150 that restricts the flow of the refrigerant into the flow path of the cooling pipe 52. The cooling block 51 has a flat plate shape, and has an upper surface connected to the pump body 10 so as to allow heat conduction and a lower surface connected to the power supply device 40 so as to allow heat conduction. The cooling block 51 has a cooling pipe 52 disposed therein. The cooling pipe 52 forms a cooling flow path through which water flows as a refrigerant, and a refrigerant inlet portion 52 i and a refrigerant outlet portion 52 o are provided so as to protrude sideways from the cooling block 51.

  The three-way valve 150 is an electromagnetically driven switching valve that adjusts the flow rate of the refrigerant supplied to the cooling device 50. FIG. 2 is a schematic diagram showing the configuration of the cooling device 50 and the internal configuration of the power supply device 40. FIG. 2 shows the positions of the temperature sensor 160 and the humidity sensor 170 in the power supply device 40. As shown in FIG. 2, the three-way valve 150 is provided in the refrigerant inlet 52i and connected to the refrigerant outlet 52o via the bypass channel 52b.

  The three-way valve 150 shuts off the inflow of refrigerant into the cooling pipe 52 in the cooling block 51 and the switching position (hereinafter referred to as supply position) where the refrigerant flows into the cooling pipe 52 in the cooling block 51, and the bypass flow path The position is switched between a switching position where the refrigerant flows into 52b (hereinafter referred to as a bypass position).

  A plurality of substrates 45 a, 45 b, 46 on which a plurality of electronic components are mounted are housed inside the casing 41 of the power supply device 40, and each electronic component is supplied with a coolant to the cooling block 51. To be cooled. Among the plurality of substrates 45a, 45b, 46, a power supply unit 151, a motor drive circuit 152, and a magnetic bearing drive circuit 153, which will be described later, are mounted on the substrates 45a, 45b, and a main control unit 140, which will be described later, A three-way valve drive circuit 154 is mounted.

  Electronic components (for example, field effect transistors (FETs), diodes, etc.) that generate a large amount of heat are mounted on the substrates 45a and 45b, and the electronic components mounted on the substrates 45a and 45b are mounted on the substrate 46. The temperature is higher than that of electronic components. The boards 45a and 45b are metal circuit boards, and are fixed to the cooling block 51 in a state where the boards 45a and 45b are connected to the lower surface of the cooling block 51 so as to conduct heat. Therefore, the substrates 45 a and 45 b are efficiently cooled by supplying the coolant into the cooling block 51. The substrate 46 is fixed to the cooling block 51 by a support member. Here, the substrate has a two-layer structure, but it may have three or more layers, and it is preferable that an electronic component with a larger calorific value be disposed closer to the cooling block 51. Further, when a metal upper lid is provided on the casing 41 of the power supply device 40, for example, the substrates 45a and 45b may be attached to the cooling block 51 via the upper lid and cooled.

  Inside the housing 41 of the power supply device 40, a temperature sensor 160 including a thermosensitive element such as a thermistor and a resistance type or capacitance type humidity sensor 170 are provided. The temperature sensor 160 is surface-mounted on the substrate 45a, and the humidity sensor 170 is surface-mounted on the substrate 46.

  In the present specification, a position near the cooling block 51 inside the housing 41 and when the refrigerant is supplied into the cooling block 51 is low in temperature, and particularly likely to cause dew condensation, is referred to as a “low temperature portion 181”. A position that is farther from the cooling block 51 than the low temperature part 181 and that is at a higher temperature than the low temperature part 181 will be referred to as a “high temperature part 182”. In the present embodiment, a temperature sensor 160 is provided in the low temperature part 181, and a humidity sensor 170 is provided in the high temperature part 182.

  When the humidity sensor 170 is provided in the low temperature part 181, the condensed water adheres to the humidity sensor 170, and there is a possibility that the humidity cannot be detected until the condensed water attached to the humidity sensor 170 evaporates. . In the present embodiment, since the humidity sensor 170 is provided in the high temperature part 182 where condensation is unlikely to occur, it is possible to prevent the condensed water from adhering to the humidity sensor 170.

  FIG. 3 is a functional block diagram showing the configuration of the turbo molecular pump 1. The turbo molecular pump 1 includes a main control unit 140, a power supply unit 151, a motor 101, a magnetic bearing 102, a three-way valve 150, a temperature sensor 160, a humidity sensor 170, a motor driving circuit 152, a magnetic bearing driving circuit 153, and a three-way valve driving circuit 154. It has.

  The power supply unit 151 includes an AC / DC conversion circuit, a DC / DC converter, and the like. The AC / DC conversion circuit converts AC power supplied to the power supply device 40 into DC power. The DC power converted by the AC / DC conversion circuit is supplied to the motor drive circuit 152, the magnetic bearing drive circuit 153, the three-way valve drive circuit 154, and the like. The direct current power converted by the AC / DC conversion circuit is converted into low voltage direct current power by the DC / DC converter and supplied to the main control unit 140.

  The main control unit 140 is configured to include an arithmetic processing unit having a CPU, a storage device such as ROM, RAM, and other peripheral circuits, and controls the operation of the turbo molecular pump 1. The main control unit 140 functionally includes a motor control unit 141, a magnetic bearing drive control unit 142, a temperature estimation unit 143, a condition determination unit 144, a valve control unit 145, and a counter 149.

  The motor drive circuit 152 drives and controls the motor 101 based on the control signal input from the motor control unit 141. The magnetic bearing drive circuit 153 drives the magnetic bearing 102 based on the control signal input from the magnetic bearing drive control unit 142. The three-way valve drive circuit 154 drives the three-way valve 150 based on the control signal input from the valve control unit 145.

  The counter 149 is a timer for measuring the time after the power is supplied to the power supply device 40.

The temperature estimation unit 143 estimates the temperature of the high temperature unit 182 based on the temperature _TL of the low temperature unit 181 detected by the temperature sensor 160. Hereinafter, the temperature estimated by the temperature estimation unit 143 is referred to as “estimated temperature”. The temperature _{T L} of the low-temperature section 181, in order to estimate the temperature _{T H} of the high temperature portion 182, know the advance of the temperature _{T H} of the temperature _{T L} and the high temperature portion 182 of the low temperature portion 181 relationship.

定数αは、主制御部１４０の記憶装置に予め記憶されている。 Relationship between the temperature T _H of the temperature T _L and the high temperature portion 182 of the low-temperature section 181 is different from the size of the power supply device 40, the arrangement of electronic components comprising a heating source. For example, the temperature _{T H} of the high-temperature portion 182, with respect to the temperature _{T L} of the low-temperature section 181, and was found to be a relation of about 1.7 times. In this case, the estimated temperature _{T H} of the high-temperature section 182, a constant alpha = 1.7 for estimating the temperature is represented by the formula (1).

The constant α is stored in advance in the storage device of the main control unit 140.

  The condition determination unit 144 determines whether the cooling operation execution condition is satisfied and whether the cooling operation stop condition is satisfied.

The cooling operation execution condition is satisfied when both (Condition 1) and (Condition 2) are satisfied.
(Condition 1) A predetermined time (t0) has elapsed since the start of power supply to the power supply unit 151 (Condition 2) It has been determined that there is no sign of condensation.

The cooling operation stop condition is satisfied when (Condition 3) is satisfied.
(Condition 3) It was determined that there was a sign of condensation.

Condition determining unit 144, when the relative humidity R _H of the high temperature portion 182 detected by the humidity sensor 170 is higher than the predetermined humidity threshold, determines that there is a sign of condensation, relative humidity R _H is a predetermined humidity threshold If it is lower than that, it is determined that there is no sign of condensation.

In the present embodiment, as the humidity threshold, there are provided a hysteresis of a first humidity threshold R1 and a second humidity threshold R2 that is higher than the first humidity threshold R1 (R1 <R2). Condition determination unit 144, the relative humidity _{R H} of the high temperature portion 182 in the case of the following first humidity threshold R1 _{(R H} ≦ R1), determines that there is no sign of condensation. Thereafter, when the relative humidity _{R H} of the high temperature portion 182 becomes the second humidity threshold R2 or _{(R H} ≧ R2), the condition determining unit 144 determines that there is a sign of condensation.

  The time threshold t0 is a time set to prevent the occurrence of condensation immediately after the supply of electric power is started, due to the supply of the refrigerant. The time threshold t0 is determined by experiments, simulations, or the like, and is stored in advance in the storage device of the main control unit 140.

  The first humidity threshold value R1 and the second humidity threshold value R2 are smaller than the reference value R0, and the magnitude relationship between R0, R1, and R2 is R1 <R2 <R0.

以下、基準値Ｒ０について詳細に説明する。 Reference value R0 may be set using the saturated vapor pressure P _H in the saturation vapor pressure P _L, and the high temperature portion 182 of the low temperature portion 181 is represented by the formula (2).

Hereinafter, the reference value R0 will be described in detail.

FIG. 4 is a diagram showing a saturated vapor pressure curve, in which the horizontal axis represents the temperature T and the vertical axis represents the saturated vapor pressure P of water vapor. The saturated vapor pressures P _L and P _H are obtained from a saturated vapor pressure curve. In the present embodiment, the approximate expression of the saturated vapor pressure curve is stored in advance in the storage device. Various functions f (T), which are approximate expressions of the saturated vapor pressure curve, have been proposed. For example, the function f (T) is expressed by the Tetens expression (3).

式（３）に高温部１８２の推定温度Ｔ_Ｈを代入することで、高温部１８２での飽和蒸気圧Ｐ_Ｈは式（５）により表される。

By substituting the temperature _TL of the low temperature part 181 into the formula (3), the saturated vapor pressure P _L at the low temperature part 181 is expressed by the formula (4).

By substituting the estimated temperature _{T H} of the high-temperature portion 182 in Equation (3), the saturated vapor pressure _{P H} of the high temperature portion 182 is represented by the formula (5).

ここで、Ｐ_Oは電源装置４０の筐体４１内の水蒸気圧である。つまり、低温部１８１での飽和蒸気圧Ｐ_Ｌに対して水蒸気圧Ｐ_Oが高い場合には、低温部１８１で結露が発生していると判定することができる。 Whether or not dew condensation is occurring in the low temperature part 181 can be determined by Equation (6).

Here, _PO is the water vapor pressure in the casing 41 of the power supply device 40. That is, when the water vapor pressure P _O is higher than the saturated vapor pressure P _L in the low temperature part 181, it can be determined that condensation occurs in the low temperature part 181.

Relative humidity _{R H} of the high temperature portion 182 is represented by equation (7).

このため、式（８）の右辺が、結露が発生している状態であるか否かを判定するための基準値Ｒ０であり、基準値Ｒ０は式（２）で表されるように電源装置４０の筐体４１内の温度変化にしたがって変化する。 Substituting equation (7) into equation (6) yields equation (8).

For this reason, the right side of Expression (8) is a reference value R0 for determining whether or not condensation is occurring, and the reference value R0 is represented by Expression (2). It changes according to the temperature change in 40 cases 41.

  In the present embodiment, in order to determine that there is a sign of condensation, as described above, the first humidity threshold R1 and the second humidity threshold R2 are set to values smaller than the reference value R0 (R1 < R2 <R0). The first humidity threshold R1 is obtained by subtracting a constant ΔR1 from the calculated reference value R0 (R1 = R0−ΔR1). The second humidity threshold value R2 is obtained by subtracting a constant ΔR2 from the calculated reference value R0 (R2 = R0−ΔR2). The constants ΔR1 and ΔR2 are stored in advance in the storage device of the main control unit 140.

  The valve control unit 145 shown in FIG. 3 switches the three-way valve 150 to the supply position (that is, operates the cooling device 50) when the cooling operation execution condition is satisfied and the flag is turned on. When the cooling operation stop condition is satisfied and the flag is turned off, the valve control unit 145 switches the three-way valve 150 to the bypass position (that is, stops the cooling device 50).

  FIG. 5 is a flowchart showing the operation of the electromagnetic valve switching process by the main control unit 140 of the power supply device 40 according to the first embodiment, and FIG. 6 is a flowchart showing the operation of the dew condensation sign determination process. When the power switch of the turbo molecular pump 1 is turned on, a valve control program is executed. After initial setting (not shown), the processing after step S100 is repeatedly executed every predetermined control cycle. In the initial setting, the flag for controlling the switching position of the three-way valve 150 is turned off.

  As shown in FIG. 5, when the power switch is turned on and the supply of power to the power supply unit 151 is started, in step S100, the main control unit 140 controls to switch the three-way valve 150 to a bypass position (blocking position). A signal is output, the refrigerant is shut off, and the process proceeds to step S110.

  In step S110, the main control unit 140 accumulates the time of the counter 149 and proceeds to step S120.

  In step S120, the main control unit 140 determines whether the time t counted by the counter 149 has exceeded the time threshold t0. If an affirmative determination is made in step S120, the process proceeds to step S130, and if a negative determination is made, the process returns to step S100.

  In step S130, the main control unit 140 resets the counter 149, that is, sets the accumulated time t to 0, and proceeds to step S140.

  In step S140, the main control unit 140 determines whether or not there is a sign of the occurrence of condensation. Step S140 is repeated until a negative determination is made, and when a negative determination (determination that there is no sign of condensation) is made, the process proceeds to step S150. It is determined according to the process shown in FIG. 6 whether or not there is a sign of the occurrence of condensation.

As shown in FIG. 6, in step S10, the main control unit 140 obtains the relative humidity _{R H} of the temperature _{T L} and the high temperature portion 182 of the low-temperature section 181 is information from the temperature sensor 160 and the humidity sensor 170, step Proceed to S20.

In step S20, the main control unit 140, based on the temperature _{T L} of the low-temperature section 181 acquired in step S10, calculates the estimated temperature _{T H} of the high temperature portion 182, the process proceeds to step S30.

In step S30, the main control unit 140, based on the temperature _{T L} of the low-temperature section 181 acquired in step S10, calculates the saturated vapor pressure _{P L} of the low-temperature portion 181, the process proceeds to step S40.

In step S40, the main control unit 140, based on the estimated temperature _{T H} of the high temperature portion 182 obtained in step S20, it calculates the saturated vapor pressure _{P H} of the high temperature portion 182, the process proceeds to step S50.

In step S50, the main control unit 140, based on the saturated vapor pressure _{P L} of the low temperature portion 181 obtained in step S30, to the saturated vapor pressure _{P H} of the high temperature portion 182 obtained in step S40, the reference value R0 Is calculated, and the process proceeds to step S60.

  In step S60, the main control unit 140 determines whether or not the switching position of the three-way valve 150 is a bypass position. If an affirmative determination is made in step S60, that is, if it is determined that the position is a bypass position, the process proceeds to step S70. If a negative determination is made in step S60, that is, if the supply position is determined, the process proceeds to step S75. The switching position of the three-way valve 150 is determined by a flag that controls the switching position of the three-way valve 150.

In step S70, the main control unit 140 calculates the first humidity threshold R1 based on the reference value R0 obtained in step S50 and the constant ΔR1 stored in the storage device, and proceeds to step S80. In step S80, the main control unit 140 determines whether the relative humidity _{R H} of the high temperature portion 182 acquired in step S10 is equal to or less than the first humidity threshold R1 obtained in step S70. If an affirmative determination is made in step 80, the process proceeds to step S90, and if a negative determination is made in step S80, the process proceeds to step S93.

  In step S90, the main control unit 140 determines that there is no sign of condensation and turns on the flag. In step S93, the main control unit 140 determines that there is a sign of condensation and turns off the flag.

In step S75, the main control unit 140 calculates the second humidity threshold R2 based on the reference value R0 obtained in step S50 and the constant ΔR2 stored in the storage device, and proceeds to step S85. In step S85, the main control unit 140 determines whether the relative humidity _{R H} of the high temperature portion 182 acquired in step S10 is the second humidity threshold value R2 or obtained in step S75. If an affirmative determination is made in step 85, the process proceeds to step S95, and if a negative determination is made in step S85, the process proceeds to step S98.

  In step S95, the main control unit 140 determines that there is a sign of condensation and turns off the flag. In step S98, the main control unit 140 determines that there is no sign of condensation, and turns on the flag.

  When it is determined in step S140 that there is no sign of condensation and the flag is turned on, in step S150, the main control unit 140 outputs a control signal for switching the three-way valve 150 to the supply position, and supplies the refrigerant. The process proceeds to step S160.

  In step S160, the main control unit 140 determines whether or not there is a sign of the occurrence of condensation, as in step S140 (steps S10 to S98). Step S160 is repeated until an affirmative determination is made. If an affirmative determination is made (determined that there is a sign of condensation), the process proceeds to step S170.

  In step S160, when it is determined that there is a sign of condensation and the flag is turned off, in step S170, the main control unit 140 outputs a control signal for switching the three-way valve 150 to the bypass position, and shuts off the refrigerant. Return to step S140.

  The operation of the first embodiment is summarized as follows. When the user turns on the power switch of the turbo molecular pump 1, electric power is supplied from an external power source (not shown) to the power supply unit 151, and the turbo molecular pump 1 is activated. The three-way valve 150 is maintained in the bypass position at least for a predetermined time (t0) after the supply of power is started (steps S100 to S120).

  If it is determined that there is no sign of dew condensation after the predetermined time (t0) has elapsed (YES in step S120, NO in S140), the three-way valve 150 is switched to the supply position (step S150), and the cooling block 51 is supplied with refrigerant. Is supplied, the power supply device 40 is cooled.

  For example, when a drive switch (not shown) for instructing driving of the motor 101 of the turbo molecular pump 1 is turned off, the vicinity of the cooling block 51 in the power supply device 40 is in a low temperature state. If it is determined that there is a sign of the occurrence of condensation at the low temperature portion 181 in the power supply device 40 (YES in step S160), the three-way valve 150 is switched to the bypass position (step S170), and the refrigerant is supplied to the cooling block 51. Blocked.

According to the first embodiment described above, the following operational effects are obtained.
(1) The main control unit 140 uses the three-way valve 150 to cause the refrigerant to flow into the flow path of the cooling pipe 52 in the cooling block 51 for a predetermined time after the supply of power to the power supply unit 151 of the power supply device 40 is started. Restrict. Thereby, it is possible to prevent condensation from occurring immediately after the power is turned on.

  By the way, if the temperature around each heat generating portion in the power supply device 40 is low before the power supply to the power supply device 40 is turned on, the heat generated in the heat generating portion is absorbed by the peripheral portion immediately after the power is turned on. For this reason, if the inflow of the refrigerant immediately starts to the cooling block 51 due to the start of the supply of power to the power supply unit 151, there is a possibility that condensation occurs due to rapid cooling. When the occurrence of condensation is detected, a warning is issued, or when control is performed to stop operation, a warning may be issued immediately after power supply to the power supply unit 151 is started, or operation may be stopped. is there. In this case, it is necessary to adjust the flow rate of the refrigerant in order to cancel the warning or restart the operation, and there is room for improvement in convenience.

  In contrast, in the present embodiment, as described above, the flow of the refrigerant into the cooling block 51 is restricted for a predetermined time after the supply of power to the power supply unit 151 is started. For this reason, it is possible to prevent the occurrence of condensation immediately after the power is turned on and improve the usability.

(2) Since supply and shut-off of the refrigerant are controlled based on whether or not there is a sign of condensation, it is possible to prevent the occurrence of condensation and to prevent malfunction due to condensation.

(3) By the way, when other equipment is connected to the refrigerant outlet side of the turbo-molecular pump 1 and the flow of the refrigerant to the cooling block 51 is controlled by an on-off valve (two-way valve), When the refrigerant flow into the block 51 is blocked, there is a problem that the refrigerant is not supplied to other devices. On the other hand, in the present embodiment, since the three-way valve 150 is employed to restrict the inflow of the refrigerant to the cooling block 51, even if the inflow of the refrigerant to the cooling block 51 is cut off, The apparatus can be supplied with a refrigerant.

-Second Embodiment-
With reference to FIG. 7 and FIG. 8, the turbo-molecular pump 1 which concerns on 2nd Embodiment is demonstrated. The turbo molecular pump 1 according to the second embodiment has the same configuration as that of the first embodiment. In the figure, the same reference numerals are assigned to the same or corresponding parts as those in the first embodiment, and the differences will be mainly described. FIG. 7 is a diagram similar to FIG. 2 and is a schematic diagram showing the positions of the temperature sensor 160 and the humidity sensor 170 in the power supply device 40 according to the second embodiment.

In the first embodiment, the example in which the temperature sensor 160 is arranged in the low temperature part 181 has been described (see FIG. 2). In contrast, in the second embodiment, is arranged a temperature sensor 160 to a high temperature portion 182, the temperature _{T H} of the high-temperature portion 182 is detected by the temperature sensor 160.

ここで、αは、温度を推定するための定数であり、本実施の形態では、α＝１．７である。定数αは、主制御部１４０の記憶装置に予め記憶されている。 In the second embodiment, the temperature estimating unit 143 shown in FIG. 3, based on the temperature _{T H} of the high temperature portion 182 detected by the temperature sensor 160, and estimates the temperature _{T L} of the low temperature portion 181. The estimated temperature _TL of the low temperature part 181 is expressed by Expression (9) obtained by modifying Expression (1).

Here, α is a constant for estimating the temperature, and α = 1.7 in the present embodiment. The constant α is stored in advance in the storage device of the main control unit 140.

  FIG. 8 is a flowchart showing the operation of the dew condensation sign determination process according to the second embodiment, in which steps S10B and S20B are added instead of steps S10 and S20 in the flowchart of FIG. .

As shown in FIG. 8, in the second embodiment, in step 10B, the main control unit 140, the relative temperatures _{T H} and the high temperature portion 182 of the high temperature portion 182 which is information from the temperature sensor 160 and humidity sensor 170 The humidity _RH is acquired, and the process proceeds to step S20B.

In step S20B, the main control unit 140, based on the temperature _{T H} of the high temperature portion 182 acquired in step S10B, calculates the estimated temperature _{T L} of the low-temperature portion 181, the process proceeds to step S30.

Thus, in the second embodiment, the temperature T _H of the high temperature portion 182 detected by the temperature sensor 160, and the relative humidity R _H of the high temperature portion 182 detected by the humidity sensor 170, the estimated low temperature part Based on the estimated temperature _{TL of} 181, it is determined whether or not there is a sign of condensation, and the switching position of the three-way valve 150 is controlled based on the determination result.

  According to such 2nd Embodiment, there exists an effect similar to 1st Embodiment.

-Third embodiment-
With reference to FIG. 3 and FIG. 9, the turbo-molecular pump 1 which concerns on 3rd Embodiment is demonstrated. The turbo molecular pump 1 according to the third embodiment has a configuration similar to that of the first embodiment. Hereinafter, differences from the first embodiment will be described.

  In the first embodiment, based on the information on the temperature of the high temperature part 182, the temperature of the low temperature part 181, and the relative humidity of the high temperature part 182, it is determined whether or not there is a sign of the occurrence of condensation. On the other hand, in the third embodiment, it is determined whether or not there is a sign of the occurrence of condensation based only on the temperature in the casing 41 of the power supply device 40, and the three-way valve 150 is determined based on the determination result. The switching control is executed. This will be specifically described below.

Condition determination unit 144 shown in FIG. 3, when the temperature T _L of the low-temperature section 181 is lower than a predetermined temperature threshold value, determines that there is a sign of condensation, the temperature T _L of the low-temperature section 181 is higher than a predetermined temperature threshold value Is too high, it is determined that there is no sign of condensation.

In the present embodiment, as the temperature threshold, there are provided a hysteresis of a first temperature threshold T1 and a second temperature threshold T2 lower than the first temperature threshold T1 (T2 <T1). When the temperature _TL of the low temperature part 181 is equal to or higher than the first temperature threshold value T1 (T _L ≧ T1), the condition determination unit 144 determines that there is no sign of condensation. Thereafter, when the temperature decreases and the temperature _TL of the low temperature part 181 becomes equal to or lower than the second temperature threshold value T2 (T _L ≦ T2), the condition determination unit 144 determines that there is a sign of condensation.

  The first temperature threshold T1 is an internal temperature at which the power supply device 40 operates stably, and is set to a temperature lower than a temperature abnormality notification temperature that is set below the allowable temperature of the electronic component. As the first temperature threshold T1, for example, a temperature comparable to the ambient environment temperature (room temperature) can be adopted.

  The second temperature threshold T2 is set in consideration of the refrigerant flow rate and the refrigerant temperature, and is stored in advance in the storage device of the main control unit 140. As the second temperature threshold T2, for example, a temperature comparable to the temperature of the supplied refrigerant can be employed.

  FIG. 9 is a flowchart showing the operation of the condensation predictor determination process according to the third embodiment, in which steps S20, S30, S40, S50, S70, and S75 in the flowchart of FIG. 6 are omitted, and FIG. Instead of step S80 and step S85 in the flowchart, step S80C and step S85C are added.

In step S80C, the main control unit 140 determines whether or not the temperature _TL acquired in step S10 is equal to or higher than the first temperature threshold T1. If a positive determination is made in step S80C, the process proceeds to step S90, and if a negative determination is made in step S80C, the process proceeds to step S93.

In step S85C, the main control unit 140 determines whether or not the temperature _TL acquired in step S10 is equal to or lower than the second temperature threshold T2. If a positive determination is made in step S85C, the process proceeds to step S95, and if a negative determination is made in step S85C, the process proceeds to step S98.

  According to such 3rd Embodiment, there exists an effect similar to 1st Embodiment.

The following modifications are also within the scope of the present invention, and one or a plurality of modifications can be combined with the above-described embodiment.
(Modification 1)
In the first and second embodiments, the example in which the constant α is used as the value for estimating the temperature has been described, but the present invention is not limited to this.

(Modification 1-1)
For example, a constant suitable for the operation state may be selected from a plurality of constants based on the operation state of the turbo molecular pump 1. The relationship between the temperature of the low temperature part 181 and the temperature of the high temperature part 182 differs between when the refrigerant is supplied into the cooling block 51 and when the supply of the refrigerant into the cooling block 51 is interrupted. For this reason, it is preferable to examine the relationship between the temperature of the low temperature part 181 and the temperature of the high temperature part 182 in advance at each switching position of the three-way valve 150.

  The difference between the temperature of the low temperature part 181 and the temperature of the high temperature part 182 is larger when the cooling operation is performed than when the cooling operation is stopped. For example, it can be seen that the temperature of the high temperature part 182 in the operation state in which the refrigerant is supplied into the cooling block 51 is about 1.7 times the temperature of the low temperature part 181. It is assumed that the temperature of the high temperature part 182 in the operation state in which the supply of the refrigerant to is cut off is approximately 1.3 times the temperature of the low temperature part 181.

  In this case, the first constant α1 = 1.7 and the second constant α2 = 1.3 are stored in the storage device of the main control unit 140 in advance. When the three-way valve 150 is switched to the supply position, the main control unit 140 selects the first constant α1 as the constant α for estimating the temperature (α = α1), and uses the equations (1) and (9). Estimate temperature. When the three-way valve 150 is switched to the bypass position, the main control unit 140 selects the second constant α2 as the constant α for estimating the temperature (α = α2), and uses the equations (1) and (9). Estimate temperature.

According to such (Modification 1-1), in addition to the same functions and effects as those of the first embodiment, the following functions and effects are achieved.
(4) When the cooling operation is being performed, the main control unit 140 compares the temperature T _H (or T _L ) detected by the temperature sensor 160 and the estimated temperature as compared to when the cooling operation is stopped. The estimated temperature is estimated so that the difference from T _L (or T _H ) becomes large. Thereby, since the estimation accuracy of temperature can be improved, the determination accuracy of the presence / absence of the occurrence of condensation can be improved.

(Modification 1-2)
When the load of the motor 101 that drives the pump body 10 of the turbo molecular pump 1 is higher than the predetermined load, the estimated temperature is detected by the temperature sensor 160 compared to the case where the load of the motor 101 is lower than the predetermined load. The estimated temperature may be estimated so that the difference from the temperature becomes large. For example, whether the motor 101 is rotationally driven or stopped is detected, and when the motor 101 is rotationally driven, it is detected by the temperature sensor 160 compared to when it is stopped. The estimated temperature can be estimated so that the difference between the estimated temperature and the estimated temperature becomes large. According to such (Modification 1-2), similarly to (Modification 1-1), since it is possible to estimate the temperature suitable for the operating state, the determination accuracy of the presence / absence of the occurrence of condensation is increased. Can be improved.

(Modification 1-3)
The value α for estimating the temperature may be a variable instead of a constant. For example, a function α (T) corresponding to the temperature detected by the temperature sensor 160 may be used as a value for estimating the temperature. According to such (Modification 1-3), similarly to (Modification 1-1), it is possible to estimate the temperature suitable for the operating state. Can be improved.

(Modification 1-4)
The power consumption of the motor is calculated, and the value α for estimating the temperature may be set so that the difference between the temperature detected by the temperature sensor 160 and the estimated temperature increases as the power consumption increases. According to such (Modification 1-4), similarly to (Modification 1-1), it is possible to estimate the temperature suitable for the operating state, and therefore, the determination accuracy of the presence / absence of the occurrence of condensation is improved. Can be improved.

(Modification 2)
In the first embodiment, an example in which the temperature detected by the low temperature part 181 is multiplied by a constant α to estimate the temperature of the high temperature part 182 will be described. In the second embodiment, the temperature detected by the high temperature part 182 is described. The example in which the constant α is divided by the calculated temperature to estimate the temperature of the low temperature part 181 has been described, but the present invention is not limited to this. Instead of multiplying or dividing by the constant α, the constant β is added to the temperature detected by the low temperature portion 181 to estimate the temperature of the high temperature portion 182, or the temperature detected by the high temperature portion 182 is constant β May be subtracted to estimate the temperature of the low temperature part 181. It is preferable to employ a method capable of estimating the temperature with higher accuracy in accordance with the relationship between the temperature of the low temperature part 181 and the temperature of the high temperature part 182 that change depending on the shape and size of the power supply device 40 and the arrangement of electronic components.

(Modification 3)
In the above-described embodiment, the example in which the supply / detour of the refrigerant to the cooling block 51 is switched by the three-way valve 150 has been described, but the present invention is not limited to this. Instead of the three-way valve 150, an electromagnetic on-off valve that can switch the supply / cutoff of the refrigerant to the cooling block 51 may be adopted.

(Modification 4)
In the above-described embodiment, the example in which the supply of the refrigerant to the cooling block 51 is cut off, that is, the supply flow rate of the refrigerant to the cooling block 51 is set to 0 is described as an example of restricting the inflow of the refrigerant to the cooling block 51. However, the present invention is not limited to this. If the supply flow rate of the refrigerant is such that the flow rate of the refrigerant supplied to the cooling block 51 can be reduced compared to when the cooling operation is being performed and the state can be returned to the state where it is determined that there is no sign of the occurrence of condensation. This means that the refrigerant is restricted from flowing into the cooling block 51 even when the refrigerant is being supplied.

(Modification 5)
In the above-described embodiment, the configuration in which the power supply device 40 is disposed below the pump body 10 has been described, but the present invention is not limited to this. For example, the power supply device 40 may be disposed on the side of the lower casing 30 of the pump body 10. Further, the present invention is not limited to the case where the pump body 10 and the power supply device 40 are combined, and both of them may be arranged and used individually. In this case, the cooling device 50 is provided in each of the power supply device 40 and the pump body 10.

(Modification 6)
In the third embodiment, in step S80C, and it determines whether or not the temperature _{T L} of the low-temperature section 181 is the first temperature threshold value T1 or more as the temperature in the housing 41, in step S85C, the low temperature portion 181 Although the example which determines whether temperature _TL is below 2nd temperature threshold value T2 was demonstrated, this invention is not limited to this. Instead of the temperature _{T L} of the low-temperature section 181 may compare the temperature _{T H} of the high-temperature portion 182 with a predetermined threshold. Instead of the temperature _{T L} of the low-temperature section 181 may compare the average value of the temperature _{T H} of the temperature _{T L} and the high temperature portion 182 of the low temperature portion 181 with a predetermined threshold.

(Modification 7)
Without being limited to the case where water is used as the refrigerant, various coolants can be used as the refrigerant.

(Modification 8)
In the above-described embodiment, the example in which the turbo molecular pump is employed as the vacuum pump has been described. However, the present invention is not limited to this, and the present invention can be applied to various vacuum pumps. For example, the present invention can also be applied to a vacuum pump having only a drag pump such as a Ziegburn pump or a Holweck pump.

  As long as the characteristics of the present invention are not impaired, the present invention is not limited to the above-described embodiments, and other forms conceivable within the scope of the technical idea of the present invention are also included in the scope of the present invention. .

DESCRIPTION OF SYMBOLS 1 Turbo molecular pump, 10 Pump main body, 11 Inlet flange, 20 Upper casing, 21 Flange, 30 Lower casing, 32 Flange, 40 Power supply device, 41 Case, 45a Substrate, 46 Substrate, 50 Cooling device, 51 Cooling block, 52 cooling pipe, 52b bypass flow path, 52i refrigerant inlet, 52o refrigerant outlet, 101 motor, 102 magnetic bearing, 140 main controller, 141 motor controller, 142 magnetic bearing drive controller, 143 temperature estimator, 144 conditions Determination unit, 145 valve control unit, 149 counter, 150 three-way valve, 151 power supply unit, 152 motor drive circuit, 153 magnetic bearing drive circuit, 154 three-way valve drive circuit, 160 temperature sensor, 170 humidity sensor, 181 low temperature unit, 182 high temperature Part

Claims (2)

A power supply for driving the vacuum pump;
A refrigerant flow path for cooling the power supply device;
A refrigerant restriction device for restricting the flow of refrigerant into the flow path;
A control device for a vacuum pump, comprising: a refrigerant control unit that restricts the refrigerant from flowing into the flow path for a predetermined time after the supply of electric power to the power supply device is started. In the vacuum pump control device according to claim 1,
The refrigerant restriction device is a three-way valve that is switched between a supply position for allowing the refrigerant to flow into the flow path and a bypass position for blocking the flow of the refrigerant into the flow path and allowing the refrigerant to flow into the detour.
The refrigerant control unit switches the three-way valve to the bypass position for a predetermined time after starting the supply of power to the power supply device, and a condition that there is no sign of condensation after the predetermined time has been satisfied. A controller for a vacuum pump that switches the three-way valve to the supply position.

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