JP4989355B2 - Turbo molecular pump - Google Patents

Description

  The present invention relates to a turbo molecular pump having a function of detecting a misconnection of wiring between a pump body and a control unit that controls the pump body.

  In the turbo molecular pump, a pump body and a control unit for controlling the pump body are connected by a cable. In particular, in a magnetic bearing type turbo molecular pump that requires motor control and magnetic bearing control, a high voltage circuit is controlled. It is necessary to perform certain motor control and magnetic bearing control, which is the control of the low voltage circuit, but if these are connected together in one cable, there may be problems with mutual insulation, etc. Connected with.

  In particular, in applications where a long cable is required (for example, an accelerator or a fusion-related facility that is required to operate in a radiation environment), since the SN ratio decreases due to the length of the cable, the low voltage circuit In order to improve noise resistance, it is necessary to relay the amplifier in the middle of the cable, and it is necessary to use a cable different from the high voltage circuit.

When pumps of different models are used using a common control unit, the connection state of the terminal unit C provided on the pump main body A is connected to the control unit B via the signal line of the cable as shown in FIG. The provided discrimination circuit D detects and performs control corresponding to the type of pump connected by the control circuit E (see, for example, Patent Document 1).
Japanese Utility Model Publication No. 7-52397

  The wiring between the conventional pump body and its control unit requires a normal motor control cable (high voltage cable) and a magnetic bearing control cable (low voltage cable) as described above. When a pump and a control unit corresponding to the pump are connected and used, if the cable is incorrectly connected, the pump may become inoperable or damaged.

  If a common control unit is provided for pumps of different models, it is possible to determine the incorrect connection of the cable from the connection status of the terminal in addition to the configuration for determining the model. Since a means for discriminating an erroneous connection from the combination of connection states is required, there is a disadvantage that the configuration becomes complicated. Furthermore, it becomes necessary to increase the wiring in the cable.

  An object of the present invention is to solve such problems and to provide means for detecting whether or not a cable connecting a pump body and its control unit is correctly connected with a simple configuration.

  In order to achieve the above object, the present invention provides a turbo molecular pump in which a pump body and a control unit that performs various controls on the pump body are connected via a high voltage cable and a low voltage cable. On the main body side, a part of wiring provided in the high-voltage cable and a part of wiring provided in the low-voltage cable are provided for detection, and the short circuit is detected on the control unit side. A detection circuit is provided.

  As a first invention related to the present invention, a turbo molecular pump in which a pump main body and a control unit that performs various controls on the pump main body are connected via a high voltage cable and a low voltage cable. A first switching unit that short-circuits the wiring of the high-voltage cable and the low-voltage cable is provided, and a detection circuit that detects the short-circuit is connected to the wiring of the high-voltage cable and the low-voltage cable on the control unit side. A second switching unit is provided.

  Further, as a second invention related to the present invention, a turbo molecular pump in which a pump main body and a control unit for performing various controls on the pump main body are connected via a high voltage cable and a low voltage cable. A first switching unit for grounding the wiring of the high-voltage cable and the low-voltage cable on the side, and a detection circuit for detecting the grounding on the control unit side for wiring of the high-voltage cable and the low-voltage cable A second switching unit to be connected is provided.

  According to the present invention, the wiring of the high voltage cable and the low voltage cable is short-circuited on the pump body side, and this is detected by the corresponding control unit, so that the erroneous connection of the cable can be easily found. It is possible to prevent inoperability and damage of the pump.

  Examples of the best mode for carrying out the present invention are shown below.

  FIG. 1 is a block diagram showing a connection state between a pump unit and a control unit of a turbo molecular pump according to an invention related to the present invention.

  Reference numeral 1 denotes a pump unit. The pump unit 1 includes a high voltage circuit 3 for driving a pump motor, a low voltage circuit 4 for operating a magnetic bearing of the pump, and a first changeover switch 5 for switching the cable wiring. It has.

  Reference numeral 2 denotes a control unit that performs pump motor control and magnetic bearing control of the pump unit 1. The high voltage control unit 6 performs pump motor control via the high voltage circuit 3 and the low voltage circuit 4. A low voltage control unit 7 for controlling the magnetic bearing, a second changeover switch 8 for switching the wiring of the cable, a detection circuit 9 for detecting the connection state of the cable, and a display 10 for displaying the normality / abnormality of the connection. Yes.

  The high voltage circuit 3 and the high voltage control unit 6 are connected by a high voltage cable 11, and the low voltage circuit 4 and the low voltage control unit 7 are connected by a low voltage cable. 12 wires were connected.

  The first changeover switch 5 is a double switch, and is interposed in the wiring of the high-voltage cable 11 and the low-voltage cable 12 in the pump unit 1, and the two switches are in a neutral position. The high voltage cable 11 and the low voltage cable 12 are both connected to each other by switching to the a side simultaneously, or by switching two switches from the neutral position to the b side at the same time. 11 and the low-voltage cable 12 are both disconnected and connected to both ends of the short-circuit line 13 via the short-circuit line 13 and the high-voltage cable 11 and the low-voltage cable 12. The wiring is configured to be short-circuited.

  The second changeover switch 8 is also composed of a double switch, and is interposed in the wiring of the high voltage cable 11 and the low voltage cable 12 in the control unit 2. By switching from the neutral state to the c side at the same time, the wiring of the high voltage cable 11 and the wiring of the low voltage cable 12 are both connected, or by switching two switches from the neutral position to the d side at the same time. The wiring of the voltage cable 11 and the wiring of the low voltage cable 12 are both disconnected and connected to the two input lines to the detection circuit 9.

  The detection circuit 9 is connected to the display 10.

  FIG. 2 shows a circuit diagram for checking the connection state. In the circuit diagram, the detection circuit 9 comprises a NOR gate 9a and an OR gate 9b, and the first input side of the NOR gate 9a and the second input side of the OR gate 9b are both The second input side of the NOR gate 9a and the first input side of the OR gate 9b are connected to the wiring of the low voltage cable 12 via a connection point 9c. These two connection points 9c and 9d are connected to a bias voltage + V through a resistor γ, and the output side of the NOR gate 9a is connected to the normal lamp 10a of the display 10 and the OR gate. The output side of 9b is connected to the abnormal lamp 10b of the display device 10, respectively.

  The short-circuit line 13 is grounded.

  When the detection circuit 9 is operated, a bias voltage + V is applied to the first and second input sides of the NOR gate 9a and the OR gate 9b via a resistor γ, and both inputs are held at a high level (H).

  Here, when the first changeover switch 5 of the pump unit 1 is switched to the b side in order to detect the connection state of the cable wiring, the terminal on the b side has a low level (L) because the short-circuit wire 13 is grounded. ) Further, by switching the second changeover switch 8 of the control unit 2 to the d side, the wiring of the high voltage cable 11 and the wiring of the low voltage cable 12 are connected to the detection circuit 9.

  That is, the wiring of the high voltage cable 11 is connected to the first input side of the NOR gate 9a and the second input side of the OR gate 9b of the detection circuit 9, and the other low voltage cable 12 is connected to the second input side of the NOR gate 9a. And connected to the first input side of the OR gate 9b.

  Therefore, when the wiring of the high voltage cable 11 and the wiring of the low voltage cable 12 are correctly connected between the pump unit 1 and the control unit 2, the first and second input sides of the NOR gate 9a and the OR gate 9b Since both are grounded via the wiring of the high voltage cable 11, the wiring of the low voltage cable 12 and the short-circuit line 13, the high level (H) changes to the low level (L).

  As a result, the output side of the NOR gate 9a is at a high level (H) and the normal lamp 10a of the display 10 is turned on, and the output side of the other OR gate 9b is at a low level (L). Not.

  When only one of the high voltage cable 11 and the low voltage cable 12 is grounded or when both are not grounded, both the first and second input sides of the NOR gate 9a and the OR gate 9b are connected. Since it does not become low level (L), the output side of the NOR gate 9a becomes low level (L), the output side of the OR gate 9b becomes high level (H), and the abnormal lamp 10b lights up.

  In this way, the operator can easily know whether the connection of the high voltage cable 11 and the low voltage cable 12 is normal or abnormal, and is normally connected to the pump unit 1 and the control unit 2. After confirming that the first switching switch 5 of the pump unit 1 is switched to the a side and the second switching switch 8 of the control unit 2 is switched to the c side, the motor is driven by the high voltage circuit 3 and the low voltage The circuit 4 can activate the magnetic bearing of the pump.

  FIG. 3 is a block diagram showing a connection state when the low voltage cable wiring is erroneously connected when the A pump 14 and the B pump 16 are used.

  That is, the wiring of the low voltage cable 12A of the A pump 14 is connected to the B control unit 17 that controls the B pump 16, and the wiring of the low voltage cable 12B of the B pump 16 controls the A pump 14. Connected with. First, in order to check the connection state between the A pump 14 and the A control unit 15 that controls the A pump 14, the detection circuit of the A control unit 15 is operated to switch the changeover switches of the A pump 14 and the A control unit 15. In this case, since the wiring of the high voltage cable 11A is correctly connected, the input of the detection circuit of the A control unit 15 connected thereto is grounded and is at the low level (L). On the other hand, the wiring of the low voltage cable 12B of the A control unit 15 is connected to the B pump 16, but since the B pump is not operating, the intercept of the changeover switch of the B pump 16 is in the neutral position and is disconnected. Therefore, the input of the detection circuit of the A control unit 15 connected to the wiring of the low voltage cable 12B is held at the high level (H).

  Therefore, since the input of the detection circuit connected to the wiring of the high voltage cable 11A and the wiring of the low voltage cable 12B in the A control unit 15 does not become low level (L), the display of the A control unit 15 Displays an error, and the operator can confirm that the cable connection is incorrect.

  Similarly, it can be easily confirmed that the connection between the B pump 16 and the B control unit 17 is wrong.

Also, when pumps of different models are controlled by a common control unit, the same switch as described above is provided for each pump, and the same switch and detection as in the case of the corresponding control unit are provided in the common control unit. A circuit and a display are provided. Then, after the cable wiring is connected, the switch of the pump is switched and the switch of the common control unit is switched, so that the connection state with the pump to be used can be confirmed in the same manner as described above. This eliminates the need to provide a combination of terminals separately from the type discrimination.

  FIG. 4 is a block diagram illustrating a connection state between the pump unit and the control unit of the turbo molecular pump according to the present invention.

  Reference numeral 23 denotes a detection wiring provided in the pump unit 1, and one of the detection wirings 23 is connected to the detection circuit 21 of the control unit 2 via another wiring in the high voltage cable 18. The other end of the detection wiring 23 is directly connected to the detection circuit 21 through another wiring in the low voltage cable 19.

  That is, the high-voltage cable 18 is provided with a wiring for connecting the high-voltage circuit 3 and the high-voltage control unit 6 and another wiring for the detection 23 separately. A wiring for connecting the voltage circuit 4 and the low voltage control unit 7 and another wiring for the detection 23 are provided.

  Thus, by closing the switch 20, the detection wiring 23 and the detection circuit 21 form a closed loop circuit, and a current is passed from the detection circuit 21 to the closed loop circuit to detect that the current is flowing. For example, the pump unit 1 can confirm that the control unit 2 is normally connected via the wiring of the high voltage cable 18 and the wiring of the low voltage cable 19.

  Therefore, the operator closes the switch 20 of the control unit 2 to check the connection state after connecting the pump unit 1 and the control unit 2 with the wiring of the high voltage cable 18 and the wiring of the low voltage cable 19.

  If it is correctly connected, it becomes a closed loop circuit as described above, so that a current flows to the detection circuit 21, and the detection circuit 21 detects this and displays on the display 22 that the connection has been made normally.

  As described above, in this embodiment, it is possible to check the connection state by closing the switch 20 of the control unit 2, and thus the operation is simple.

  In addition, when an erroneous connection is made when using a plurality of pumps as shown in FIG. 3, only the control unit switch 20 to be inspected is closed, and the other control unit switches 20 are opened. Since the closed loop circuit is not formed and no current is detected by the detection circuit 21, the display 22 displays an abnormality.

  As described above, in the first embodiment, the method for detecting the connection state of the pump unit and the control unit when using two cables of the low voltage cable and the high voltage cable has been described. However, the present invention is not limited to this. Even when two or more cables are used, it is possible to detect an erroneous connection of cables by detecting the grounding or short circuit of two wirings in a similar manner.

  The turbo molecular pump of the present invention is a molecular pump that requires connection of a high voltage cable wiring and a low voltage cable wiring, and is used when operating a plurality of molecular pumps of different models.

It is a block diagram which shows the connection state of the pump main body side and control part side of the turbo-molecular pump of the invention relevant to this invention. It is a circuit diagram which investigates a connection state. It is a block diagram which shows the connection state at the time of connecting a cable incorrectly. It is a block diagram which shows the connection state of the pump main body side and control part side of the turbo-molecular pump of Example 1 of this invention. It is a block diagram which shows the connection state of the conventional turbo molecular pump.

DESCRIPTION OF SYMBOLS 1, 14, 16 Turbo molecular pump 2, 15, 17 Control part 5 1st changeover switch 8 2nd changeover switch 9,21 Detection circuit 10,22 Display 11, 18, 11A, 11B High voltage cable 12, 19, 12A, 12B Low voltage cable 13 Short circuit 20 Switch 23 Detection wiring

Claims (3)

In a turbo molecular pump that connects a pump body and a control unit that performs various controls to the pump body via a high voltage cable and a low voltage cable, the turbo molecular pump is provided on the pump body side in the high voltage cable . Turbo, wherein said that the detection circuit for detecting a short circuit was only set to the control unit side together with a portion of the wiring the provision of interconnection for the detection of short-circuiting wiring portion provided on the low voltage in the cable Molecular pump. Wherein the control unit, a turbo molecular pump according to claim 1, wherein the sensing circuit is provided with a first display for lighting display and detects the short circuit. Wherein the control unit, the detection circuit is a turbo-molecular pump according to a second display for lighting display and detecting in claim 1 or claim 2 it is provided that is not the short.

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