Method of and apparatus for controlling vacuum pump

• US 6,364,621 B1
• Filed: 05/01/2000
• Issued: 04/02/2002
• Est. Priority Date: 04/30/1999
• Status: Expired due to Fees

• Current Assignee: Almo Technos Co., Ltd. (Amase Create Co.)
• Original Assignee: Almo Technos Co., Ltd. (Amase Create Co.)
• Inventors: Yamauchi, Kazuhiko
• Primary Examiner(s): FREAY, CHARLES GRANT
• Application Number:
  US09/562,326
• Time in Patent Office: 701 Days
• Field of Search: 417/2, 417/12, 417/44.1, 417/45, 417/44.11
• US Class Current: 417/44.11
• CPC Class Codes: F04B 2203/0208 Power
• CPC Class Codes: F04B 49/065 and making use of computers
• CPC Class Codes: F04B 49/20 by changing the driving speed

Abstract

There is disclosed a controlling apparatus for controlling at least one vacuum pump and comprising: at least one vacuum pump having a pump body for sucking a gaseous body from a clean room and exhausting the clean room or the gaseous body and a driving motor for driving the pump body; and a controlling section for controlling the driving motor. The controlling apparatus includes a power measurement device, which measures a driving power to be sent to the driving motor. If the power measurement device measures power which reaches or exceeds a warning value, above a fixed value, then the controlling section switches the state of the at least one vacuum pump from a steady operational state into an unusual event checking state, during which an inspection of the vacuum pump is carried out.

Claims

1. A controlling apparatus, for controlling at least one vacuum pump, comprising:

at least one vacuum pump which includes a pump body for sucking a gaseous body from a room and exhausting the room of the gaseous body and a driving motor for driving the pump body; and

controlling means for controlling the driving motor included in each of said at least one vacuum pump, and said apparatus

including a power measurement device which measures driving power to be sent to the driving motor, and

wherein said controlling means switches a state of said at least one vacuum pump from a steady operational state into an unusual event checking state, in which any unusual event in said at least one vacuum pump is detected, when a value of the power measured by said power measurement device is equal to or exceeds a warning value which is higher than a fixed value, and

wherein said controlling means controls the state of said at least one vacuum pump from the unusual event checking state into the steady operational state, when the power of the driving power decreases to a safe value, which is lower than the fixed value, during a first setting period which said vacuum pump is in operation in the unusual event checking state.

2. The controlling apparatus for controlling at least one vacuum pump, according to 1, wherein said controlling means which includes unusual event determining means for determining whether the driving motor included in said at least one vacuum pump is in an unusual state, and said unusual event determining means determines that the driving motor is in the unusual state, when the steady operational state and the unusual event checking state of said at least one vacuum pump is repeatedly switched from one to another for a predetermined number of times.

3. The controlling apparatus, for controlling at least one vacuum pump, according to claim 1, wherein said controlling means controls the state of said at least one vacuum pump from the unusual event checking state back into the steady operational state, when the power measured by said power measurement device substantially drops or substantially stays constant throughout a first setting period while said at least one vacuum pump is in operation in the unusual event checking state.

4. The controlling apparatus, for controlling at least one vacuum pump, according to claim 3, wherein said controlling means includes unusual event determining means for determining whether the driving motor included in said at least one vacuum pump is in an unusual state, and said unusual event determining means determines that the driving motor is in the unusual state, when the steady operational state and the unusual event checking state of said at least one vacuum pump is switched from one to another for a predetermined number of times.

5. The controlling apparatus, for controlling at least one vacuum pump, according to claim 4, wherein said unusual event determining means calculates an increasing rate of the power measured by said power measurement device while said at least one vacuum pump is in the steady operational state, and determines, when the calculated increasing rate of the measured power is equal to or exceeds a predetermined value, that the driving motor is in an unusual state.

6. The controlling apparatus, for controlling at least one vacuum pump, according to claim 1, wherein said controlling means includes unusual event determining means for determining whether the driving motor included in said at least one vacuum pump is in an unusual state, and said unusual event determining means determines, when the power measured by said power measurement device substantially increases while said at least one vacuum pump is in operation in the unusual event checking state, that the driving motor is in the unusual state.

7. The controlling apparatus, for controlling at least one vacuum pump, according to claim 1, said apparatus including an inverter for controlling a rotational frequency of the driving motor included in said at least one vacuum pump, and

wherein said controlling means controls the inverter which converts a frequency of a driving current to be sent to the driving motor, so that, when the state of said at least one vacuum pump is switched from the steady operational state into the unusual event checking state, the frequency of the driving current to be sent to the driving motor decreases, thereby the rotational frequency of the driving motor drops.

8. The controlling apparatus, for controlling at least one vacuum pump, according to claim 1, wherein:

said controlling section includes hazardous event determining means for determining whether the driving motor is in a hazard state;

said hazardous event determining means determines that the driving motor is in the hazard state, when the value of the power measured by the power measurement device is equal to or exceeds a hazard value which is higher than the warning value; and

said controlling means switches the state of said at least one vacuum pump into a hazard operational state.

9. A controlling apparatus, for controlling at least one vacuum pump, comprising:

at least one vacuum pump which includes a pump body for sucking a gaseous body from a room and exhausting the room of the gaseous body and a driving motor for driving the pump body; and

controlling means for controlling the driving motor included in each of said at least one vacuum pump, and said apparatus

including a power measurement device which measures driving power to be sent to the driving motor, and

wherein said controlling means switches a state of said at least one vacuum pump from a steady operational state into an unusual event checking state, in which any unusual event in said at least one vacuum pump is detected, when a value of the power measured by said power measurement device is equal to or exceeds a warning value which is higher than a fixed value, and

wherein at least one open-close door is arranged along the room;

said controlling means switches the state of said at least one vacuum pump from the steady operational state into an intensive operational state, in which suction of the gaseous body from the room is effectively performed, when said open-close door is open or closed; and

said at least one vacuum pump is maintained to be in operation in the intensive operational state throughout a second setting period.

10. A method of controlling at least one vacuum pump, which comprises a pump body for sucking a gaseous body from a room and exhausting the room of the gaseous body and a driving motor for driving the pump body, said method comprising:

switching a state of said at least one vacuum pump from a steady operational state into an unusual event checking state, in which any unusual event in said at least one vacuum pump is detected, when a value of driving power to be sent to the driving motor is equal to or exceeds a warning value, which is higher than a fixed value; and

controlling the state of said at least one vacuum pump from the unusual event checking state into the steady operational state, when the power of the driving power decreases to a safe value, which is lower than the fixed value, during a first setting period which said vacuum pump is in operation in the unusual event checking state.

11. The method of controlling at least one vacuum pump, according to claim 10, said method comprising

controlling the state of said at least one vacuum pump from the unusual event checking state into the steady operational state, when the driving power substantially drops or substantially stays constant through the first setting period, while said at least one vacuum pump is in operation in the unusual event checking state.

12. The method, of controlling at least one vacuum pump, according to claim 10, said method comprising unusual event determining means for determining whether said at least one vacuum pump is in an unusual state, and wherein

said unusual event determining means determines that the driving motor is in an unusual state, when the steady operational state and the unusual event checking state of said at least one vacuum pump is repeatedly switched from one to another for a predetermined number of times.

13. The method, of controlling at least one vacuum pump, according to claim 11, said method comprising unusual event determining means for determining whether said at least one vacuum pump is in an unusual state, and wherein

said unusual event determining means determines that the driving motor is in an unusual state, when the steady operational state and the unusual event checking state of said at least one vacuum pump is repeatedly switched from one to another for a predetermined number of times.

14. The method, of controlling at least one vacuum pump, according to claim 10, said method comprising unusual event determining means for detecting any unusual event in said at least one vacuum pump, and

wherein said unusual event determining means determines that the driving motor is in an unusual state, when the value of the driving power substantially increases, during the unusual event checking state of said at least one vacuum pump.

15. The method, of controlling at least one vacuum pump, according to claim 14, wherein said unusual event determining means determines that the driving motor is in an unusual state, when an increasing rate of the driving power is equal to or exceeds a predetermined value, during the steady operational state of said at least one vacuum pump.

16. The method, of controlling at least one vacuum pump, according to claim 10, wherein a rotational frequency of the driving motor is lower, during the unusual event checking state of said at least one vacuum pump, than a rotational frequency of the driving motor, during the steady operational state of said at least one vacuum pump.

17. The method, of controlling at least one vacuum pump, according to claim 10, said method including hazardous event determining means for determining that said at least one vacuum pump is in a hazard state, and

wherein hazardous event determining means determines that said at least one vacuum pump is in a hazard state, when the value of the driving power is equal to or exceeds a hazard value, which is higher than the warning value, and switches the state of said at least one vacuum pump into a hazard operational state.

18. A method, of controlling at least one vacuum pump, which comprises a pump body for sucking a gaseous body from a room and exhausting the room of the gaseous body and a driving motor for driving the pump body, wherein at least one open-close door is arranged along the room, said method comprising:

switching a state of said at least one vacuum pump from a steady operational state into an unusual event checking state, in which any unusual event in said at least one vacuum pump is detected, when a value of driving power to be sent to the driving motor is equal to or exceeds a warning value, which is higher than a fixed value;

switching the state of said at least one vacuum pump from the steady operational state into an intensive operational state, in which suction of the gaseous body from the room is effectively performed, when the at least one open-close door is open or closed; and

maintaining the intensive operational state for a second setting period.