JPH08241653A - Position detecting device for switch - Google Patents

Abstract

PURPOSE: To obtain the position detecting device for a switch, which can always monitor the operation condition of the switch and which can eliminate the incorrect operation due to the induction serge. CONSTITUTION: At the time of opening and closing a switch part, when a body 2 to be detected comes close to a magnetic sensor 11 with the movement of a main spindle 1, the output voltage from the magnetic sensor 11 becomes large. This output voltage is converted to the frequency by a V/F converting unit 13, and converted to the optical signal by an E/O converting unit 14. This optical signal is transmitted to the receiver side, which is not showed in the figure, through an optical fiber 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switch position detecting device for detecting a switching operation state of an electrical switch such as a gas insulated switchgear.

[0002]

2. Description of the Related Art Generally, power switchgear in which electrodes and conductors are housed in a hermetically sealed container is used in a power station substation, switchgear, and the like. As such an electric switch, a gas-insulated switchgear excellent in insulation performance and arc extinction performance is widely used. This gas-insulated switchgear is a switchgear in which a fixed electrode and a movable electrode are operably arranged in a sealed case in which a gas is sealed, and a puffer mechanism is additionally formed on the movable electrode side. When the electrodes are opened / closed, the insulating gas compressed by the puffer mechanism is blown to extinguish the arc generated between the electrodes. Further, an insulating rod and an operating rod are attached to the movable electrode, and the movable electrode is opened and closed by the vertical movement of the operating piston of the operating mechanism connected via the insulating rod and the operating rod.

In a switch such as such a gas-insulated switchgear, the open / close operation state of the switch is displayed,
In order to measure the opening / closing operation time, an auxiliary switch is provided in the operation mechanism section. This auxiliary switch has an auxiliary contact that opens and closes in conjunction with the opening and closing operation of the operating mechanism.

However, in this auxiliary switch, since the auxiliary contact, which is a mechanical contact, is the operation source, as the number of times of opening / closing operations of the opening / closing section increases, galling or oxidation occurs on the contact due to wear, adhesion of foreign matter, or the like. , It may become impossible to connect. Also,
Since it is a switch that is simply turned on / off, there is a problem that the state of the contact cannot be diagnosed when it is turned off.

Therefore, recently, with the development of a monitoring system for the purpose of predicting an abnormality of a switch,
As a means for detecting the opening / closing operation state of the switch, a contactless proximity type sensor has been used in place of the conventional auxiliary switch. Examples of this type of sensor include a proximity sensor described in JP-A-63-43820 and JP-A-63-48718, and an optical sensor described in JP-A-02-7317.

First, the proximity sensor has a metal flange attached to the operation rod as a body to be detected, and is configured to be sensitive to this approach. The proximity sensor includes a sensor that detects a closed state of the movable electrode and a sensor that detects an open state of the movable electrode. That is, each proximity sensor detects an open position and a closed position of the metal flange and issues an open position signal and a closed position signal, respectively, when the movable electrode and the operation rod connected to the movable electrode are in the open state and the closed state. It is like this. The detection signals of these proximity sensors are transmitted to the relay board by cables, respectively, and serve as input signals to the sensor receiver and the measuring unit in the relay board.

Next, the optical sensor includes a transmission type and a reflection type. The transmission type optical sensor is
The light emitting unit and the light receiving unit are arranged so as to face each other, and the detection target is arranged so as to block the light path between the light emitting unit and the light receiving unit when the detection target operates. The operating state of is detected. In addition, the reflection type optical sensor irradiates the detected object with light and collects the reflected light at the light receiving section so that the sensor head detects the approach of the detected object and detects the operating state of the detected object. To do. The object to be detected is attached to a predetermined position of a mechanism that interlocks with the opening / closing operation of the switch, and operates according to the operation of this mechanism to detect the position. Since these optical sensors use light as the position detecting means of the object to be detected, they have an advantage that they are more excellent in noise resistance than the contactless proximity sensor.

[0008]

However, each of the above-mentioned sensors has the following problems. First, since the output of the contactless proximity sensor is an electric signal, there is a high possibility that the contactless proximity sensor may malfunction due to an induced surge generated when the main circuit of the switch is turned on and off. Further, there is a problem that it is difficult to diagnose the sensor itself at all times (especially when it is off) because it is an output form that simply electrically turns on / off the transistor circuit.

Further, the above optical sensor has the following problems. In the case of the transmissive type, the amount of transmitted light changes significantly due to contamination of the light emitting and light receiving surfaces, so it is difficult to apply it to switches used outdoors from the viewpoint of sensor reliability. Further, when the transmitted light is blocked, there is a problem in that it is not possible to detect the damage of the sensor and the abnormality such as the step line of the optical fiber. Further, in the case of the reflection type, the light amount may vary due to dirt on the reflection surface, which reduces the reliability of the sensor. Further, since the object to be detected is away from the sensor, there is a problem that the abnormality of the sensor and the optical fiber cannot be similarly detected when the reflected light does not return.

On the other hand, in such a switch, when carrying out a periodic inspection, a stroke curve showing the moving distance of the movable electrode, that is, the relationship between the operating position of the switch and time is measured. Conventionally, when performing the test for the above inspection,
A complicated jig was attached to the base of the switch operating mechanism for measurement, and the jig was removed when the test was completed, which was a complicated task. From the viewpoint of streamlining the inspection work, there has been an increasing demand for a sensor for easy and highly reliable stroke measurement.

The present invention has been made in view of the above problems, and an object thereof is a position detecting device capable of constantly monitoring the operating state of a switch and not malfunctioning due to inductive surge or the like. To provide. Another object of the present invention is to provide a position detecting device for a switch which can easily perform stroke measurement.

[0012]

According to a first aspect of the present invention, there is provided a position detecting device for a switch according to the present invention. A device main body part having an opening / closing part for performing an opening / closing operation, and an opening / closing operation movable for opening / closing the opening / closing part. Of a switch which is attached to a switch having an operating mechanism including a section, and which detects the position of an object to be detected which is fixedly provided in the opening / closing operation movable section, thereby detecting the operating state of the switch. In the position detection device, a magnetic sensor that outputs a voltage according to the distance to the object to be detected,
It is characterized by comprising a position detection sensor including a voltage / frequency conversion unit for converting the output of the magnetic sensor into a frequency and an electric / optical conversion unit for converting the frequency into an optical signal.

According to a second aspect of the present invention, there is provided the switch position detecting device according to the first aspect of the present invention, wherein the object to be detected has a different magnetic pole or magnetic force. It is characterized in that a plurality of them are provided in the movement direction.

According to a third aspect of the present invention, there is provided the switch position detecting device according to the first aspect of the present invention, wherein a plurality of objects having different magnetic poles are provided as the objects to be detected. It is characterized in that it is arranged at a position facing the position detection sensor when the operation of the switch is "closed" and at a position facing the position detection sensor when the operation of the switch is "cut off".

A switch position detecting device according to a fourth aspect of the present invention is characterized in that, in the first aspect of the invention, the object to be detected is composed of a multipolar magnetic material.

According to a fifth aspect of the present invention, there is provided a position detecting device for a switch, comprising: an apparatus main body part having an opening / closing part for performing an opening / closing operation; and an operating mechanism having an opening / closing operation movable part for opening / closing the opening / closing part. In a switch position detecting device which is attached to a switch having, and which detects an operating state of the switch,
A magnetic sensor that is connected to an auxiliary switch having a contact that opens and closes in conjunction with the opening and closing operation of the opening and closing unit and outputs a voltage according to the rotation angle of the main shaft of the auxiliary switch, and the output of the magnetic sensor as a frequency. It is characterized by comprising a position detection sensor including a voltage / frequency conversion unit for conversion and an electric / optical conversion unit for converting the frequency into an optical signal.

A switch position detecting device according to a sixth aspect of the present invention is characterized in that, in the first or fifth aspect of the invention, the magnetic sensor comprises a magnetoresistive element.

[0018]

In the present invention having the above structure,
The following effects are obtained. That is, according to the first aspect of the present invention, when the detection target fixedly provided in the opening / closing operation movable unit approaches the magnetic sensor during the opening / closing operation of the opening / closing unit, the output voltage from the magnetic sensor becomes large. Becomes This output voltage is converted into a frequency by the voltage / frequency conversion unit and converted into an optical signal by the electric / optical conversion unit. This allows
For example, an optical signal can be transmitted to a receiver or the like, converted into an electric signal in the receiver or the like, and the position of the object to be detected can be measured according to the magnitude of the voltage. As described above, since the optical signal is always output regardless of the ON / OFF state of the switch, it is possible to constantly monitor the position with the position detection sensor. Further, by using the output of the position detection sensor as an optical signal, the reliability in transmission is significantly improved as compared with the case where a proximity switch is used.

Further, since all the circuits from the position detecting sensor to the receiver are composed of optical or electric circuits, the time delay is extremely small as compared with the case where a mechanical relay is used.

According to the second aspect of the invention, by providing a plurality of objects to be detected having different magnetic poles or magnetic forces,
With only one position detection sensor, it is possible to detect which one of the detection objects approaches the position detection sensor.
Therefore, the cost can be reduced.

According to the third aspect of the invention, the position detecting sensor measures the operating state of the switch by detecting the position of the object to be detected having different magnetic poles arranged according to the operation of the switch. be able to.

According to the fourth aspect of the invention, the output from the position detection sensor changes according to the magnetism of the object to be detected. Therefore, for example, when the size of the object to be detected is increased so as to cover the portion facing the position detection sensor when the switch is "closed" and the portion facing the position detection sensor when "closed", It is possible to measure the stroke curve according to the movement of the detected object.

According to the fifth aspect of the invention, when the main shaft of the auxiliary switch rotates in conjunction with the opening / closing operation of the opening / closing section, the output from the magnetic sensor changes according to the rotation angle. The output of this magnetic sensor is converted into an optical signal via the voltage / frequency converter and the electric / optical converter. Thereby, for example, an optical signal can be transmitted to a receiver or the like, converted into an electric signal in the receiver or the like, and the position of the object to be detected can be measured according to the magnitude of the voltage. In this way, opening / closing
Since the optical signal is always output regardless of the off state, it is possible to constantly monitor with the position detection sensor. Further, by using the output of the position detection sensor as an optical signal, the reliability in transmission is significantly improved as compared with the case where a proximity switch is used.

According to the sixth aspect of the present invention, it is possible to detect the output voltage according to the change in the resistivity of the magnetic sensor according to the distance from the object to be detected.

[0025]

Embodiments of the present invention will be described below with reference to the drawings. In the following first to fourth embodiments, the opening / closing operation state of the opening / closing device is detected by detecting the position of the object to be detected attached to the operation rod.

A. First Embodiment (A-1) Configuration of First Embodiment FIG. 1 is a diagram showing a configuration of a position detection device according to a first embodiment of the present invention. Reference numeral 1 denotes a main shaft (operation rod) attached to a movable electrode (not shown), which moves in the direction of arrow AA ′ in the figure with respect to the operation of the movable electrode. Further, a detected body 2 made of a magnetic material is attached to the main shaft 1,
It is designed to move with the spindle 1.

Numerals 10a and 10b are position detection sensors fixed to a base (not shown) of the operating mechanism, and the detected object 2
Is configured to transmit an output according to the moving distance of the. The position detection sensors 10a and 10b correspond to respective positions of the detected object 2 when the operating state of the switchgear is "ON (closed)" and "OFF (shut off)". Two are installed in the longitudinal direction of. The detection signals from the position detection sensors 10a and 10b are input to the receiver or the like housed in a relay board (not shown) via the optical fiber 16.

A surge voltage is generated on the base to which the position detection sensors 10a and 10b are fixed by induction when the main circuit is opened and closed. Therefore, in the high voltage switchgear, the position detection sensors 10a and 10b are attached while being insulated from the base.

Next, an internal circuit which constitutes the position detection sensor 10a (10b) will be described. Each of these internal circuits is electrically shielded by the housing of the position detection sensor 10a (10b).

Reference numeral 11 is a magnetic sensor including a magnetic resistance element and the like. The output voltage of the magnetic sensor 11 changes depending on whether the detected body 2 approaches or leaves. Reference numeral 12 is an amplifier that amplifies the output voltage of the magnetic sensor 11, and an operational amplifier is normally used. Reference numeral 13 is a V / F (voltage / frequency) converter that converts the output voltage of the amplifier 12 into a frequency signal. The V / F converter 13 converts, for example, the output voltage 1 to 2 V of the amplifier 12 into 50 kHz to 100 kHz. The frequency converted here must be selected at a level that does not hinder the monitoring of the operating characteristics of the switch. Normally, the operating time of the switch is about 15 ms to 20 ms, so the conversion frequency by the V / F conversion unit 13 may be selected to be several tens kHz or more.

Reference numeral 14 is an E / O (electrical / optical) converter, which converts the electrical signal pulse output from the V / F converter 13 into an optical signal. Further, the E / O converter 14 transmits the above optical signal to the receiver side (not shown) via the optical fiber 16. This optical signal is converted into an electrical signal in the receiver and compared with a reference voltage by a comparator. Here, this reference voltage is set so as to correspond to turning on / off of the switchgear, and the output signals from the position detection sensor 10a and the position detection sensor 10b depend on whether the reference voltage is higher than this reference voltage. The judgment of ON / OFF is made.

Reference numeral 17 denotes a power cable, which is connected to the position detecting sensor 10a (10
Power is supplied to the constant voltage power supply 15 of b). The power supply cable 17 is connected to the constant voltage power supply 15 via a noise filter (not shown) at the entrance of the housing of the position detection sensor 10a (10b). In this way, the power cable 1
7 is connected to the constant voltage power supply 15 in a state of being completely shielded inside the housing of the position detection sensor 10a (10b), so that the power supply cable 17 connects the position detection sensor 10a (10b).
Noise does not enter inside b).

(A-2) Operation and effect of the first embodiment Next, the operation of the position detecting device according to the first embodiment having the above-mentioned structure will be described. First, when the operating state of the opening / closing device is "ON (closed)", the detected object 2 faces the position detection sensor 10a as shown in FIG. At this time, the output voltage of the magnetic sensor 11 of the position detection sensor 10a is high, and the output from the position detection sensor 10a is turned on at the receiver side.

When the operating state of the switchgear is "off (shut-off)", the spindle 1 moves in accordance with the opening / closing operation of the operating mechanism,
The detected object 2 moves in the direction of arrow A '. As a result, the output voltage from the magnetic sensor 11 of the position detection sensor 10a becomes small, and the output from the position detection sensor 10a is turned off on the receiver side. Then, when the detected object 2 moves to a position facing the position detection sensor 10b as shown in FIG. 1, the output voltage of the magnetic sensor 11 of the position detection sensor 10b becomes large and the position detection sensor 1
The output of 0b is turned on.

As described above, according to this embodiment, the optical signal is always output regardless of the ON / OFF state of the switch.
It becomes possible to constantly monitor. Further, since the detection signal from the position detection sensor 10 is transmitted to the receiver side by the optical fiber 16, the reliability of signal transmission is significantly improved as compared with the case where the proximity switch is used.

In this embodiment, the position detecting sensor 10
Since the circuit from the receiver to the receiver is composed entirely of optical or electrical circuits, the time delay is extremely small compared to the case of using a mechanical relay. Therefore, the operating characteristics of the switchgear can be more accurately monitored using the outputs of these position detection sensors.

B. Second Embodiment (B-1) Configuration of the Second Embodiment FIG. 2 is a diagram showing the configuration of the position detection device according to the second embodiment of the present invention. In the present embodiment, the spindle 1 is provided with two detection objects 2a and 2b. These detected objects 2
A permanent magnet is used for a and 2b, and the N pole and the S pole of the permanent magnet face the position detection sensor 10 at the positions corresponding to "ON" and "OFF" of the switch operating state, respectively. To be installed.

(B-2) Operation and effect of the second embodiment In the present embodiment, when the opening / closing operation is "on", the operation shown in FIG.
As shown in FIG. 2A, the S pole of the detected object 2b faces the position detection sensor 10, and when it is “off (cut off)”, as shown in FIG. 2B, the N pole of the detected object 2a. Is the position detection sensor 10
To face. As a result, the output voltage of the magnetic sensor 11 changes, and the opening / closing operation is detected. As described above, according to the present embodiment, the operating state of the gas-insulated switchgear can be detected and monitored by only one position detection sensor 10, so that the cost can be reduced.

C. Third Embodiment (C-1) Configuration of the Third Embodiment FIG. 3 is a diagram showing the configuration of the position detection device according to the third embodiment of the present invention. In this embodiment, two position detecting sensors 10 are provided in the position detecting device according to the second embodiment shown in FIG. In this case, between the pair of position detection sensors 10,
The detected body 2 is positioned.

(C-2) Operation and effect of the third embodiment According to this embodiment, the object 2 to be detected is detected by the pair of position detection sensors 10, so that more precise measurement can be performed.

D. Fourth Embodiment (D-1) Configuration of Fourth Embodiment FIG. 4 is a diagram showing a configuration of a position detection device according to a fourth embodiment of the present invention. In this embodiment, as shown in FIG. 4A, a multipolar magnetic body is used as the detected body 2 in the position detecting device according to the second embodiment shown in FIG.

(D-2) Operation and effect of the fourth embodiment With such a structure, the position detecting sensor 10
A pulse voltage as shown in FIG. 4B is output from the amplifying unit 12 of FIG. Here, FIG. 4C shows a stroke curve 40 that represents the moving distance of the movable electrode, that is, the relationship between the operating position of the switchgear and time. The output pulse shown in FIG. 4B starts output at a position corresponding to the operation start point A of the stroke curve 40 shown in FIG. 4C and ends output at a position corresponding to the operation end point B. Therefore, the operating position of the switchgear can be detected by measuring this output pulse.

As described above, according to this embodiment, since the stroke curve can be measured, it is possible to monitor the change in the operating state of the switchgear with high accuracy. In order to reduce the cost of the detected body 2, the multipolar detection body 2 may be arranged only at the position for detecting the "ON" state and the position for detecting the "OFF" state of the switchgear. Good.

E. Fifth Embodiment (E-1) Configuration of Fifth Embodiment In the above-described first to fourth embodiments, the example in which the contactless position detection sensor 10 is used for the operating mechanism has been described.
In the embodiment, an example using the rotation of the main shaft of the auxiliary switch is shown. Further, the position detecting device according to the present embodiment is shown in FIG.
The stroke curve shown in can be measured.

FIG. 5 is a diagram showing a position detecting device according to this embodiment. In FIG. 5A, 3 is a lever,
The linear motion of the main shaft 1 of the switchgear in the direction of arrow AA 'is transmitted to the main shaft 4 of the auxiliary switch 5 in the direction of arrow BB' as a rotary motion in the direction of arrow BB '.

Further, in FIG. 5B, 20 is a stroke measuring sensor, which is the same as the auxiliary switch 5 in the base 1
It is installed on 9. This stroke measuring sensor 20
Is connected to the auxiliary switch main shaft 4 via an insulating coupling 6. In the stroke measuring sensor 20,
Reference numeral 18 denotes an angle sensor composed of a magnetic resistance element or the like, which outputs a voltage corresponding to the rotation angle of the main shaft 4. The parts other than the angle sensor 18 are the same as the position detection sensor 10 shown in FIG.

The detection signal from the stroke measuring sensor 20 is input through the optical fiber 16 to a receiver or the like housed in a relay board (not shown).
Then, it is converted into an electric signal on the receiver side and compared with a reference voltage by a comparator. Here, the reference voltage is set in correspondence with turning on / off of the switchgear, respectively. For example, when the rotation angle of the auxiliary switch main shaft 4 becomes a constant angle, the output voltage of the magnetic sensor 18 becomes a constant magnitude, and the detection signal from the stroke measuring sensor 20 becomes larger than a constant reference voltage. , The operation start point A of the stroke curve 40 shown in FIG. 4 (c) is detected.
Further, due to the change in the output voltage of the magnetic sensor 18, the voltage of the detection signal from the stroke measuring sensor 20 gradually decreases, and when the voltage becomes equal to or lower than a predetermined reference voltage, the operation end point B is detected.

Also in this case, as in the case of the position detection sensor 10, the conversion frequency by the V / F conversion unit 13 is set to several tens of kHz.
If it is selected to be z or more, it does not affect the accuracy of stroke measurement. In addition, the stroke measurement sensor 2
Since the internal circuit of 0, the power supply cable 16, and the like are configured to prevent noise, the configuration is similar to that of the position detection sensor 10, so that malfunction due to inductive surge or the like can be prevented.

(E-2) Operation and Effect of Fifth Embodiment In the structure as described above, when the operating condition of the switchgear is "ON", the main shaft 1 is moving in the direction of arrow A, and the auxiliary work is performed accordingly. The switch main shaft 4 is rotating in the arrow B direction. At this time, the angle sensor 18 corresponding to the rotation angle of the spindle 4
Output voltage is high, and the signal is higher than a constant reference voltage on the receiver side.

When the operating state of the opening / closing device is "OFF", the spindle 1 moves in the direction of arrow A'with the opening / closing operation of the operating mechanism, and the spindle 4 rotates in the direction of arrow B 'accordingly. The output voltage of the angle sensor 18 corresponding to the rotation angle of the main shaft 4 gradually decreases. Then, on the receiver side, when the signal becomes lower than a predetermined reference voltage, it is detected that the switchgear is turned off.

As described above, according to the present embodiment, the stroke curve can be measured without requiring the complicated work of the prior art. Further, the stroke measuring sensor 20 can be easily attached not only to a newly manufactured switchgear but also to an existing switchgear. Further, in this way, the stroke measurement sensor 20 is attached to the operating mechanism of the opening / closing device, and the detection signal thereof is pulled out to the outside of the operating mechanism of the opening / closing device, or is pulled out to the control panel at the site to perform inspection / checking. Workability during testing is greatly improved.

(E-3) Modified Example of Fifth Embodiment FIG. 6 is a diagram showing a modified example of the fifth embodiment. this is,
This is a case where the main shaft 1 makes a rotational movement with respect to the movement of the movable electrode. As shown in FIG. 6 (a), the main shaft 1 has a lever 3 a,
It is connected to the auxiliary switch main shaft 4 via 3b, and rotates in accordance with the opening / closing operation of the operating mechanism 21. Also in this case,
As shown in FIG. 6B, the stroke curve can be measured by attaching the above-described stroke measuring sensor 20.

[0053]

As described above, according to the present invention, since the detection signal is constantly output, it is possible to constantly monitor the operating state of the switch. Further, since the output signal is output as an optical signal, the sensor does not malfunction due to inductive surge or the like. Therefore, it is possible to provide a highly reliable switch position detecting device.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing the configuration of a switch position detecting device according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram showing a configuration of a switch position detecting device according to a second embodiment of the present invention.

FIG. 3 is a schematic diagram showing a configuration of a switch position detecting device according to a third embodiment of the present invention.

4A is a schematic diagram showing the configuration of a switch position detecting device according to a fourth embodiment of the present invention, FIG. 4B is a diagram showing an output voltage in the same embodiment, and FIG. 4C is a diagram showing a stroke curve. .

FIG. 5 is a schematic diagram showing the configuration of a switch position detecting device according to a fifth embodiment of the present invention.

FIG. 6 is a schematic view showing a modification of the switch position detecting device according to the embodiment.

[Explanation of symbols]

 1 ... Spindle 2 (2a, 2b) ... Object to be detected 3 ... Lever 4 ... Auxiliary switch main spindle 5 ... Auxiliary switch 6 ... Insulation coupling 10 (10a, 10b) ... Position detection sensor 11 ... Magnetic sensor 12 ... Amplification unit 13 ... V / F converter 14 ... E / O converter 15 ... Constant voltage power supply 16 ... Optical fiber 17 ... Power cable 18 ... Angle sensor 19 ... Base 20 ... Stroke measurement sensor 21 ... Operating mechanism 40 ... Stroke curve

Claims (6)

[Claims] 1. A switch having an apparatus main body part having an opening / closing part for performing an opening / closing operation and an operation mechanism having an opening / closing operation movable part for opening / closing the opening / closing part, the opening / closing operation movable part being attached to the opening / closing operation movable part. In a position detecting device for a switch, which detects an operating state of the switch by detecting the position of a detection target fixedly provided, a magnetic sensor which outputs a voltage according to a distance from the detection target. And a voltage for converting the output of the magnetic sensor into a frequency /
Frequency converter and electric / electrical converter for converting the frequency into an optical signal
A position detection device for a switch, comprising a position detection sensor including a light conversion unit. 2. A plurality of the objects to be detected, each of which has a different magnetic pole or magnetic force, are provided in the operation direction of the opening / closing operation movable portion.
Switch position detecting device described. 3. A plurality of objects having different magnetic poles are provided as the objects to be detected, and each of the objects to be detected has a position facing the position detection sensor when the operation of the switch is “closed”, and The switch position detecting device according to claim 1, wherein the switch position detecting device is arranged at a position facing the position detecting sensor when the operation of the switch is "blocked". 4. The position detecting device for a switch according to claim 1, wherein the object to be detected is made of a multi-pole magnetic material. 5. An operating state of the switch attached to a switch having an apparatus main body section having an opening / closing section for performing an opening / closing operation and an operation mechanism having an opening / closing operation movable section for opening / closing the opening / closing section. In a position detecting device for a switch that detects a magnetic field, the magnetic field is connected to an auxiliary switch having a contact that opens and closes in conjunction with the opening / closing operation of the opening / closing unit, and outputs a voltage according to a rotation angle of a main shaft of the auxiliary switch. A switch including a sensor, a voltage / frequency conversion unit for converting an output of the magnetic sensor into a frequency, and an electric / optical conversion unit for converting the frequency into an optical signal. Position detection device. 6. The position detecting device for a switch according to claim 1, wherein the magnetic sensor comprises a magnetoresistive element.