JPH02252996A - Magnetic bearing turbo molecular drag pump - Google Patents

Abstract

PURPOSE:To ease an investigation of the cause of an accident by operating a warning means, when the temperature detected by a temperature sensor, which is arranged at a place requiring temperature watching, exceeds a a warning level and making a memorizing means memorize the detected temperature at this time together with time information. CONSTITUTION:Temperature sensors T, which detect respective internal temperatures of a bearing control part, an inverter, and of an emergency battery and which also detects an electromagnetic coil temperature and a motor coil temperature, are provided, and the output signals from the sensors T are inputted into a judging means 5. Next, it is judged whether or not the temperature detected by each temperature sensor exceeds the permissible level set up in advance, and if it is judged that the detected temperature exceeds a warning level, a warning means 6 is operated. In addition, at least the detected temperatures at this time together with time information are memorized by a memorizing means 7, so that the memorized contents can be used as a clue to find out the cause of an accident.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic bearing turbomolecular pump (hereinafter abbreviated as TMP) which is widely applicable to various fields that utilize ultra-high vacuum.

[Prior Art] FIG. 5 shows a conventional TMP main body 1, in which 10 is a shaft to which a bell-shaped rotor is fixed.

In order to float and support the shaft 10, active radial magnetic bearings 11, 12 and active thrust magnetic bearings 13 are arranged around the shaft.

In order to control these bearings 11, 12, 13, displacement sensors 11a, 12a, 13 are installed near each bearing.
A is arranged to detect a minute gap between the bearings, and the detected value is manually input to the bearing control section 2 as shown in FIG. In the bearing control unit 2, for example, a detected value inputted from a displacement sensor lla is amplified by an amplifier 21, this is converted into a differential correction signal by a controller 22, and the electromagnet of the magnetic bearing 11 is appropriately driven via a driver 23. It is possible to apply voltage. The same applies to other displacement sensors 12a113a.

Further, a high frequency motor 14 is provided to drive the shaft 10, and is driven by a motor control section 3 comprising an inverter 31 capable of varying the oscillation frequency and output voltage, and an OR circuit 32. That is, TMPl can be started up by inputting a start command to the inverter 31, and braking can be applied to TMPl by inputting a stop command to the OR circuit 32. These start/stop commands are basically made by external operations.

By the way, the bearing control section 2, motor control section 3, etc. described above generate a lot of heat due to Joule heat, and the temperature also exceeds TM.
It is generally known that P depends greatly on installation conditions, external environment, etc. For this reason, temperature sensors 24 and 33 are provided at these locations as shown in the figure to monitor the temperature.

That is, the detected temperature taken out from the sensor 24.33 is input to the abnormality processing circuit 41 to determine whether it exceeds a preset abnormal level, and if it exceeds the abnormal level, the entire system becomes uncontrollable. It is assumed that a failure has occurred and the abnormality indicator 42 is turned on, and a stop command is forcibly input to the OR circuit 32.

[Problem to be solved by the invention] However, simply such a temperature monitoring function cannot
It will not operate unless the temperature rises to a dangerous level.
The problem is that it is difficult to avoid accidents.

For example, even if a TMP is installed in a bad environment and the temperature gradually rises from the beginning of operation, the signs of this will not be known until an abnormality is displayed, so an accident may occur at the same time as the abnormality is displayed. , there is a high possibility that this will lead to a situation where there is no time to take action. Therefore, in the worst case, the TMP itself will be damaged, causing great damage to the purpose of use of the vacuum equipment and the like. Moreover, the conventional TMP has the problem that it is extremely difficult to investigate the cause of an accident after it occurs, and some kind of countermeasure is desired in this respect as well.

The present invention has been made with attention to such problems, and an object of the present invention is to improve the reliability of TMP by solving these problems.

[Means for Solving the Problems] In order to achieve the above object, the present invention employs the following configuration.

That is, the TMP device of the present invention, as shown in FIG.
and judgment means 5 which sequentially inputs the detected temperature taken out from this temperature sensor T and judges whether or not the detected temperature exceeds a preset warning permissible level. It is characterized by comprising a warning means 6 which is activated when it is determined that the temperature is high, and a storage means 7 which can store at least the detected temperature at this time together with time information.

[Operation] With this configuration, if the warning tolerance level is set to a value lower than the conventional abnormality level, the warning means will issue a warning before the TMP temperature rises unreasonably, so inspections, etc. can be carried out in advance. It becomes possible to take measures against this. At this time, the storage means stores at least the detected temperature when the TMP reaches the warning permissible level together with the time information, which is useful as a clue for investigating the cause of the accident.

[Embodiment] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In principle, the same parts as those in FIG. 6 are given the same reference numerals, and the explanation thereof will be omitted.

Thus, in the TMP according to this embodiment, temperature sensors T to T are arranged at five locations shown in FIG. That is,
The temperature sensor T1 is for detecting the internal temperature of the bearing control unit 2, the temperature sensor T2 is for detecting the internal temperature of the inverter 31, and the temperature sensor T3 is for detecting the internal temperature of the inverter 31. Temperature sensor T4 is used to detect the temperature of the electromagnet coil inside the TMP body 1, and temperature sensor T5 is used to detect the temperature of the motor coil inside the TMP body 1. It is for detection.

Detection signals VT1, VT□, VT3, V-work 4, and V-work are detected from these temperature sensors T1 to T5.

is input to the data processing unit 8 newly added in this embodiment. The data processing section 8 includes a preprocessing circuit 81, an A/D converter 82, a microcomputer 83, an output port 84, a warning indicator 85 (warning means of the present invention), an interface 86, and an abnormality indicator 42. It consists of The preprocessing circuit 81 is equipped with a multiplexer function, and serves to peak-hold analog signals vT1 to VT5 taken out from each temperature sensor T1 to T in parallel, and sequentially guide them to an output terminal. The A/D converter 82 binarizes the peak value VP output from the preprocessing circuit 81.

The microcomputer 83 serves as both the judgment means and storage means of the present invention, and is equipped with a CPU and ROMSRAM, and also has a built-in real-time calendar function that provides date and time information. A program for controlling the CPU is written in the ROM, and the CPU performs calculations according to the program and can output appropriate control signals to the output port 84 and the interface 86.Furthermore, in other areas in the ROM, Two threshold values T L s T H (
TL<TH) is stored, and the former is used as a warning permissible level and the latter as an abnormality permissible level, each of which is used as a reference value for comparative judgment to be described later. Furthermore, a data area for storing detected temperature, date and time data, etc. is secured in the RAM.

The CPU also outputs an image display 85 .
42 can be turned on and off individually, and a stop command can be manually input to the OR circuit 32 of the motor control section 3.

Further, a display 92 and a printer 93 are connected to the interface 86 via a terminal computer 91, and by operating the computer 91,
The data stored in the AM is transferred to these devices 92.
．． 93 so that it can be taken out at any time.

Here, the program written in the ROM is shown in a flowchart as shown in FIG. The operation of this embodiment will be described below with reference to the same figure.

When the program starts, first, in step S1, the multiplexer in the preprocessing circuit 81 is controlled to take out the detection signal VT1 of the temperature sensor T, for example. After that, in step S2, the peak value V is A/D converted,
In step S3, the data is taken into the CPU. Then, in step S4, it is determined whether or not it is equal to or higher than the abnormality tolerance level TH. If YES, the process goes to step S, and it is determined whether "abnormality is occurring" is set at that time (register ). If NO, "abnormality occurring" is newly set in step S6, and a label indicating "abnormality occurring" is attached in step S7, and it is stored in the data area as event data along with the date and time information, and the program is executed. Finish. Also, in step S, YES
If it is determined to be S, the program ends as is.

On the other hand, if the determination in step S4 is NO, the process goes to step S8 to determine whether "abnormality occurring" is set at that time. If YES, the setting is canceled in step S, and a label of "abnormality canceled" is attached in step S1o, and it is stored in the data area as event data together with the date and time information at that time, and the program ends.

Further, if the determination in step S8 is No, the process proceeds to step Sll, where it is determined whether the detected temperature is equal to or higher than the warning permissible level T.

If YES, the process goes to step S12, and it is determined whether or not "warning occurring" is set at that time. If the result is NO, "warning occurring" is newly set in step S13, and "warning occurring" is set in step S814.
The event data is labeled as event data and stored in the data area along with the date and time information, and the program ends. On the other hand, if the determination in step 812 is YES, the program ends immediately.

Furthermore, if the determination in step 811 is NO, the process proceeds to step 815, where it is determined whether "warning in progress" is set at that time.

If YES, the setting is canceled in step S16, and a label of "warning canceled" is attached in step S17, and it is stored in the data area as event data together with the date and time information at that time, and the program ends.

Furthermore, if the determination in step S15 is No, the program ends immediately.

Then, in the above flowchart, the program returns to the start from the point where it ended, and this time the next detection signal (
For example, take out the VT2) and perform the same operation. By repeating this series of operations, each temperature sensor T
The detected values V1, ~VT, of 1 to T5 are continuously checked when the TMPL starts operating, and each event data of abnormality occurrence, abnormality cancellation, warning occurrence, and warning cancellation is accumulated in the data area in the RAM. It turns out.

However, if this is the case, the warning indicator 85 will light up when the TMP temperature has risen unreasonably.
Since it is notified that the vehicle is not being operated normally, by taking measures such as inspection in advance, it becomes possible to prevent sudden accidents like those in the past. Moreover,
Information related to the TMP temperature is stored in the data area of the RAM, so by operating the terminal computer 91 to retrieve and check the information, you can verify the situation concretely and regularly and prevent the temperature from rising. The cause can be investigated. -For example, with conventional TMPs, it was not possible to easily judge the pros and cons of installation locations, etc., but with this TMP, if the temperature has risen from the time the pump was installed, it can be installed immediately. You will be able to easily infer whether the cause is due to poor conditions or the external environment.

In addition, if the detected temperature exceeds the abnormality tolerance level T, the protection function is activated and the TMP is urgently stopped as in the past, but since this TMP retains event data as described above, it is difficult to determine the cause of the abnormality. The investigation becomes easy.

Although one embodiment of the present invention has been described above, there is no problem even if the temperature sensors T4, T shown by broken lines in FIG. 2 are not provided. That is, from a practical point of view, if at least one temperature sensor is placed in the same control loop, the desired purpose can be achieved to some extent. It is also effective to provide the abnormality tolerance level and warning tolerance level with a certain hysteresis between the occurrence and release as shown in FIG. 4. In the same figure, when the abnormality tolerance level occurs, TH+Δ
t1, TH-Δt1 when canceling, TL+Δt2 when the warning tolerance level occurs, and TL-Δt2 when canceling. Furthermore, the contents can be further enriched by storing other necessary event data in the data area. If the terminal computer 91 is not used to retrieve this event data, the microcomputer 83 may drive the display 92 and printer 93 in real time. It also serves as a means of memory. Furthermore, such TM
If it is P, it will be easy to create a network using a common computer when operating in parallel, and centrally manage the temperature. In addition, the configuration of each part can be modified in various ways without departing from the spirit of the present invention.

[Effects of the Invention] According to the TMP of the present invention, when there is a temperature change, a warning is issued by the warning means, and the detected temperature at that time is stored in the storage means together with time information, so that specific inspections can be carried out in advance. This makes it possible to improve reliability.

[Brief explanation of drawings]

FIG. 1 is a configuration explanatory diagram showing the TMP of the present invention. Second
3 shows an embodiment of the present invention, FIG. 2 is a circuit diagram, and FIG. 3 is a flowchart. FIG. 4 is an explanatory diagram showing another embodiment of the present invention. Furthermore, FIGS. 5 and 6 show conventional examples, FIG. 5 is a vertical cross-sectional view of TMP, and FIG.
The figure is a circuit diagram corresponding to FIG. 2. T...Temperature sensor 5...Judgment means 6...Warning means 7...Storage means

Claims (1)

[Claims] A temperature sensor placed at a location where temperature monitoring is required,
A judgment means that sequentially inputs the detected temperature taken out from the temperature sensor and judges whether it exceeds a preset warning tolerance level, and a judgment means that determines whether the detected temperature exceeds the warning tolerance level. 1. A magnetic bearing turbo-molecular pump comprising: a warning means that is activated when the temperature is exceeded; and a storage means capable of storing at least the detected temperature at this time together with time information.