JPH0481597A - Protector for pump - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a pump protection device used to detect and protect a pump from abnormality.

[Prior Art] FIG. 4 shows, as an example of a pump, the standard configuration of a Tavo molecular pump, which is widely used in the vacuum field including semiconductor film forming apparatuses. This pump consists of a pump body 101 that performs an evacuation action, and a power supply section 102 that drives a motor M of this pump body 101. Power supply part 1
In 02, the AC power supply voltage is rectified in the converter 103,
A DC voltage is obtained by smoothing, and this is converted into DC-DC.
The voltage V is regulated to the required voltage V through the converter 104, and the voltage V is converted to three-phase AC with the required frequency f by the inverter 105, and this is applied to the three-phase low-voltage high-frequency motor M via the two cables 109. That's what I do. The control unit 106 is in charge of variable control of the voltage V and frequency f at this time, and performs feedback control to prevent overcurrent, overvoltage, and output frequency overflow. A control power source 107 connected to the converting section 103 applies an alternating current voltage generated by a chopper or the like to the control section 106.

Further, this pump is equipped as standard with a thermostat 108 in the pump body 101 to protect the motor M from burning out.
/F is connected to construct a protection device. Then, when a temperature abnormality is detected in the thermostat 108, the same signal as when the stop button is operated on the interface I/F is input to the control unit 106, and the control unit 106 executes sequence control related to stopping. It has become.

[Invention or problem to be solved] By the way, Turho molecular pumps can generally be divided into high vacuum type and wide area type.The high vacuum type uses air cooling with a fan, and the wide area type uses water cooling by running cooling pipes. It is carried out. Therefore, is it possible to consider adding an abnormality detection means to detect an increase in fan temperature or a lack of cooling water amount to the above-mentioned protection device?In general systems, this is not particularly required, and the current Turho molecular pump is They are not equipped as standard. For this reason, conventionally, when these were actually needed, a new protection device had to be constructed by adding a power supply circuit, cable, load circuit, etc., which was time-consuming and This prolongs the pump's downtime and reduces operating efficiency, and it also requires redundant power supply circuits, cables, buzzers, sensors, etc. compared to the case where these protective devices were integrated from the beginning. However, the number of unnecessary parts increases, leading to higher costs.

The present invention has been made with attention to such problems, and it is possible to keep the configuration installed in a standard type pump to the minimum necessary, and to easily accommodate the addition of an abnormality detection means. The purpose is to provide a protective device for pumps that are

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

That is, the pump protection device according to the present invention includes a single-phase AC power supply circuit having a current detection means for detecting a conduction state of a positive current and a current detection means for detecting a conduction state of a negative current in a power supply part. In addition, the pump body is provided with a main abnormality detection means that switches the open/closed state of the contacts according to the detection result, and a rectification means that allows only conduction of either a positive current or a negative current to the main abnormality detection means. The main load circuit is provided with a main load circuit, and the single-phase AC power circuit of the power supply section and the main load circuit of the pump body are connected by two cables.

[Function] In this way, in the standard specification protection device in which only the main load circuit is connected to the single-phase AC power supply circuit, the main abnormality detection means of the two current detection means in the single-phase AC power supply circuit is Only the one that detects a current with the same polarity as the current that conducts constitutes a closed circuit with the main load circuit every 1/2 period of the single-phase AC wave, and the main abnormality detection means detects whether or not current flows. Detection results can be retrieved.

On the other hand, if it becomes necessary to provide an auxiliary abnormality detection means separately from the main abnormality detection means, a current with a polarity opposite to the current flowing through the main abnormality detection means will be applied to the auxiliary abnormality detection means. By configuring an auxiliary load circuit having a rectifying means that only allows conduction of
The current detection means that normally does not react forms a closed circuit with the auxiliary load circuit at a phase position shifted by 1/2 period from the previous current detection means, and depending on whether or not current flows, the auxiliary abnormality detection means Detection results can be retrieved.

[Example] Hereinafter, an example of the present invention will be described with reference to FIGS. 1(a) and (b) and FIG. 2.

This protection device, as shown in Fig. 1(a),
is provided with a single-phase AC power supply circuit 4 having a current detection means 1 for detecting a conduction state of a positive current and a current detection means 2 for detecting a conduction state of a negative current when viewed from the power supply side,
A thermostat 5 is disposed on the pump body B at a position where the temperature of the motor can be detected, and serves as a main abnormality detection means that closes the contacts when the motor temperature is normal and opens the contacts when the motor temperature is abnormal. A main load circuit 7 having a diode 6 as a rectifier that allows only conduction of positive current is provided, and the terminal 4a of the single-phase AC power supply circuit 4 and the terminal 7a of the main load circuit 7 are connected by two cables 8. are doing.

Specifically, the current detection means 1 includes a Zener diode ZD1, a photocoupler PH, and a diode D1.
The secondary voltage vT of the transformer T is positive only during normal operation when the thermostat 5 of the main load circuit 7 connected between the terminals 4a is closed and the entire circuit forms a closed circuit. When the voltage reaches the breakdown voltage periodically for the Zener diode ZD, the current is conducted, the diode in the photocoupler PH2 emits light, and the transistor shown in the same figure (b) is turned on. There is.

At this time, the collector potential Vc1 becomes rLJ due to a voltage drop through the resistor R1, and after being inverted by the inverter INV1, rHJ is input to the low active AND circuit IC. On the other hand, 2 of transformer T
When the next voltage Vτ periodically takes a negative value, or when the thermostat 5 is abnormally open, no current flows and the photocoupler PH1 does not operate. At this time, the collector potential V
. 1 is held at VCC and becomes rHJ, and inverter I
After inversion at N1, rLJ is input to the AND circuit IC.

On the other hand, the transformer T includes a Zener diode ZD3.
, a photocoupler PH3, and a synchronous signal generating means 3 consisting of a diode D3.

This synchronizing signal generating means 3 causes a diode in the photocoupler PH3 to emit light in synchronization with the operating timing of the current detecting means 1, and turns on a transistor, and the collector potential V is set every half cycle. 3 to rLJ to make the AND circuit IC operable. That is, only when the output of the photocoupler PH3 becomes "L" and the output of the photocoupler PH becomes "H" is satisfied, both input terminals of the AND circuit IC are set to "L". and the AND circuit IC.

The abnormal signal s1 can be output from the second
(see figure).

Further, the current detection means 2 includes a Zener diode ZD2,
Its main parts are composed of a photocoupler PH2 and a diode D2, and since the polarity of the current allowed by the diode D2 is different from the polarity of the current allowed by the diode 6 of the main load circuit 7, the current polarity is usually between the terminals 4a. It is in a state equivalent to being released and is no longer in operation. A flowmeter 9 is connected between the terminals 4a, for example, as shown by the imaginary line in the figure, the contacts are open in normal conditions and closed in abnormal conditions.
, and an auxiliary load circuit 11 having a diode 10 that only allows conduction of negative current when viewed from the power supply side is connected to the flowmeter 9, and the flowmeter 9 is closed and the entire circuit is closed. Only in the event of an abnormality that constitutes a closed circuit, the transformer T
The secondary voltage V of the Zener diode ZD takes a negative value.
When the breakdown voltage is periodically reached with respect to the photocoupler PH2, a current is made to conduct, causing the diode in the photocoupler PH2 to emit light and turning on the transistor. At this time, the collector potential V. 2 is rL due to the voltage drop across resistor R2.
J, and at that time, if the photocoupler PH2 and the AND circuit IC2 are connected through the jumper line JP, the "L" is input to the low active AND circuit IC2. On the other hand, when the secondary voltage V of the transformer T periodically takes a positive value and when the flowmeter 9 is open and normal, no current flows and the photocoupler PH2
doesn't work. At this time, the collector potential is held at V(() and becomes rHJ, which is input to the AND circuit IC2.

On the other hand, this AND circuit IC2 also has a synchronizing signal generating means 3.
Unlike the above, the output state of is inputted manually after being inverted by inverter INV2, and the AND circuit IC2 can be operated at a phase position shifted by half a period from the timing at which the AND circuit IC becomes operable. I'm trying to keep it in good condition.

In other words, only when the conditions are satisfied that the pressure of the photocoupler PH3 becomes rHJ and the output of the photocoupler PH2 becomes "L", the AND circuit I
Both input sides of C2 are set to rL, and the AND circuit IC2
The abnormality signal s2 can be outputted from.

Incidentally, the abnormality signals s1 and s2 outputted from both the AND circuits IC, IC2 are input to the alarm 13 and the control section 106 shown in FIG. 3 via the latch circuit 12. Then, a warning sound is emitted to notify the abnormality, and the control unit 106 executes sequence control related to stopping.

If this is the case, the standard equipment will be the cables, latch circuits, alarms, control parts, etc., which are the same as the conventional components used only for mixed coal detection, and the current circuit 1.2.3 .7.11 has been slightly changed or added, and there is almost no impact on productivity in terms of cost or man-hours. However, if this pump is used, for example, as a wide-area type, and the load at that time is large and cooling is an important factor, the load circuit 11 consisting of the flow meter 9 and the diode] 0 described above may be Connect between terminals 7a and 7a of the jumper wire JP
You can build a system to monitor flow abnormalities by simply connecting the . Therefore, compared to the conventional case of constructing a separate protection device using overlapping components, it is possible to meet new demands regarding abnormality detection with far less cost, time, and effort.

Note that the present invention is not limited to the embodiments described above. For example, as the auxiliary abnormality detection means, it is possible to apply a thermostat or the like that detects temperature abnormality of the fan when the pump is used as a high vacuum type, and
In the case of a load circuit that simply connects the terminals 7a, it can be used as means for detecting disconnection of the cable 8 or the like. Furthermore, although the above-mentioned AND circuit is a low active type, if a high active type is used, it is only necessary to change the insertion position of the inverter. Also,
In the above embodiment, two AND circuits are provided so that it is possible to identify which of the load circuits an abnormality has occurred, or if it is sufficient to simply detect that an abnormality has occurred somewhere, the circuit shown in FIG. 3 is used. As shown in FIG.
The circuit can be omitted by connecting to. Furthermore, the main abnormality detection means as standard equipment is not limited to the thermostat, but if it is more important to detect abnormalities in the flow rate or fan, this may be provided as standard equipment. Others, such as applying this protection device to other pumps with similar problems,
Various modifications can be made without departing from the spirit of the invention.

[Effects of the Invention] As explained above, the present invention is designed so that the configuration installed as a standard type is kept to the minimum necessary limit, and moreover, when the need for adding abnormality detection means arises, it can be easily handled. A protection device for the pump can be provided.

[Brief explanation of the drawing]

1(a), (b) and FIG. 2 show an embodiment of the present invention, FIGS. 1(a) and (b) are circuit diagrams, and FIG. 2 is a time chart. FIG. 3 is a partial circuit diagram showing another embodiment of the present invention. FIG. 4 is a configuration explanatory diagram showing a conventional turbo molecular pump. A...Power supply part B...Pump body 1...
- Current detection means (for positive current) 2... Current detection means (for negative current) 4... Single phase AC power supply circuit 5... Main abnormality detection means (thermostat) 6... Rectification means ( diode) 7...Main load circuit 8...Cable

Claims (1)

[Claims] The power supply section is provided with a single-phase AC power supply circuit having a current detection means for detecting the conduction state of positive current and a current detection means for detecting the conduction state of negative current, and the pump body has
A main load circuit is provided that has a main abnormality detection means that switches the open/closed state of the contact according to the detection result, and a rectification means that allows only conduction of either a positive current or a negative current to the main abnormality detection means. A protection device for a pump, characterized in that a single-phase AC power circuit of a power supply section and a main load circuit of a pump body are connected by two cables.