JP3735549B2 - Switching device and portable operation device using the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a switching device that outputs a NO signal of an NO contact and an NC signal of an NC contact simultaneously and in particular, and electrically inverts an NC signal output from a mechanical NC contact to a NO signal. It is related with the switching apparatus provided with the means to output.
[0002]
In addition, the present invention is connected to an external device such as a manufacturing device or an inspection device installed in a factory or the like, displays status information regarding the external device, receives input information for operating the external device, The present invention relates to a portable operating device that includes the above-described switching device.
[0003]
[Prior art]
In general, there are a wide variety of devices such as manufacturing devices and inspection devices (hereinafter referred to as external devices) installed in factories and the like, and usually there are pipes, valves, conveyors, etc. related to each external device. Equipment and installation conditions are different. For this reason, it is necessary to check the status information regarding each external device and perform an appropriate operation corresponding to the confirmation, and the portable operation device is used for smoothly processing these complicated operations.
[0004]
Here, the portable operation device is connected to an external device, and displays means for displaying status information about the external device, and input transmission for receiving input information for operating the external device and transmitting the input information to the external device. Means for operating an external device, and is also called a teaching unit. The input transmission means of such a portable operation device is usually equipped with an emergency stop switching device such as a button or a lever for emergency stop of the external device in an emergency.
[0005]
The switching device has an NO contact that outputs an NO signal and an NC contact that outputs an NC signal. However, an emergency contact switching device usually employs an NC contact to cut off the circuit in an emergency.
[0006]
Some switching mechanisms are electrically controlled, but in order to eliminate the instability due to electrical malfunction and increase the reliability of the switching operation, the emergency stop switching device is mechanically connected to the NC signal. A switching mechanism having a mechanical NC contact for outputting is widely used.
[0007]
In addition, in European standard EN418 which is a safety standard related to emergency stop, a switching device having two mechanical NC contacts is required for a switching device for emergency stop. If the design conforms to the safety standard and two mechanical NC contacts output two independent NC signals, even if one mechanical NC contact may not be opened due to a failure, the other This is because the mechanical NC contact is opened and the emergency stop is performed safely.
[0008]
Furthermore, in recent years, the demand for judging whether or not there is an emergency stop signal as well as the emergency stop of the external device by cutting off the circuit in an emergency as described above has been increased in constructing the control system of the production line. Yes. As a result, for example, the state of the emergency stop switching device can be monitored even during normal operation.
[0009]
In order to make it possible to determine the presence or absence of an emergency stop signal, it is necessary to provide at least one NO contact that operates simultaneously with the NC contact of the emergency stop switching device. As a conventional technique related to such a switching device, for example, Japanese Patent Application Laid-Open No. 8-11084 discloses two contact points (1NC / 1NO) that have one NC contact and one NO contact and operate mechanically. An emergency stop device employing the above switching device is disclosed. As described above, when one NO contact that operates simultaneously is provided, and further conforms to the safety standard, three contact points that have two NC contacts and one NO contact and operate mechanically ( 2NC / 1NO) switching device is required.
[0010]
FIG. 4 is a schematic diagram showing the configuration of a switching device with three contacts (2NC / 1NO) according to the prior art. As shown in FIG. 4, in the switching device with three contacts (2NC / 1NO) according to the prior art, two mechanical NC contacts 40 that output two independent NC signals, and one independent NO signal And a single mechanical NO contact 41 for outputting.
[0011]
The three independent contacts each have an insulative coupling portion 42 that insulates and couples them, and is mechanically interlocked. That is, when the insulative coupling portion 42 is displaced in the illustrated mechanical input direction (black arrow direction), the mechanical NC contact 40 is opened and the mechanical NO contact 41 is closed.
[0012]
[Problems to be solved by the invention]
However, in the above structure, there is a state in which none of the contacts are closed while the mechanical NC contact 40 is open and the mechanical NO contact 41 is closed. It is impossible for the contacts 41 to operate simultaneously in a strict sense. If there is a problem in the displacement of the insulative coupling portion 42 due to some problem, the consistency between the two contacts cannot be maintained, and there may be a problem in controlling the external device or the like.
[0013]
Further, in the above switching device, the mechanical NC contact 40 and the mechanical NO contact 41 are mixed, so that the structure becomes complicated. Therefore, the manufacturing cost is higher than the case of manufacturing a three-contact (3NC) switching device having three mechanical NC contacts or a three-contact (3NO) switching device having three mechanical NO contacts. Not only is the versatility low, but a dedicated production line is required.
[0014]
An object of the present invention is to provide a switching device that has good mechanical interlocking, can easily maintain the consistency between the NC signal and the NO signal, and can keep the manufacturing cost low. It is said.
[0015]
In addition, by using the above-described switching device, the present invention not only cuts off the circuit in the event of an emergency, but also makes it possible to determine the presence or absence of an emergency stop signal as well as to make an emergency stop even during normal operation. It is an object of the present invention to provide a portable operating device that can strengthen the control system of a production line, such as being able to monitor the state of a switching device for use.
[0016]
[Means for Solving the Problems]
In order to achieve the above object, a switching device (1) according to the present invention operates mechanically in conjunction with each other and is normally closed (NC: normally closed) contact independent of each other. A switching mechanism having at least three mechanical normally closed contacts (hereinafter referred to as mechanical NC contacts) for outputting a switching signal (hereinafter referred to as NC signals); and at least one mechanical of the mechanical NC contacts. Switching of NC signal that is connected to NC contact (hereinafter referred to as selected mechanical NC contact) and output from the selected mechanical NC contact is normally open (hereinafter referred to as NO contact). signal (hereinafter, referred to as NO signal) and a switching signal inverting means for by inverting output, that the switching signal inverting means is constituted by electrically insulated means It is characterized.
[0017]
According to the switching device (1), the mechanical interlocking of the contacts can be improved, the consistency between the NC signal and the NO signal can be easily maintained, and the manufacturing cost can be kept low. Moreover, since two NC contacts can be used for emergency stop among three NC contacts, even if one mechanical NC contact may not be opened due to a failure, the other mechanical NC contact Is opened and the emergency stop can be performed more safely. Further, since the switching signal inverting means inverts the NC signal to the NO signal and outputs it, the NO signal can be transmitted to a device for notifying an emergency such as an alarm in an emergency, for example. Furthermore, since the switching signal inverting means is constituted by means that is electrically insulated, it is possible to avoid current flowing into the emergency stop switch side.
[0018]
In the switching device ( 2 ) according to the present invention, in the switching device (1) , the switching signal inversion means includes an input end and an output end, and is connected to the other end of the selected mechanical NC contact. An inverting unit that receives a potential at the input terminal (hereinafter referred to as an input potential) from the input terminal and outputs a potential obtained by inverting the input potential (hereinafter referred to as an inverted output potential) to the output terminal; A light emitting means for changing a light emitting state by a potential difference between the inverted output potential at one end connected to the output end of the inverting unit and a potential at the other end, and electrically insulated from the light emitting means, The optical signal transmission unit includes a light receiving unit that senses the light emission state of the light emitting unit and outputs a signal, and an output unit that receives the signal and outputs the NO signal based on the signal. It is characterized in that.
According to the switching device ( 2 ), an inexpensive switching signal inverting means can be realized.
[0019]
In the switching device ( 3 ) according to the present invention, in the switching device ( 2 ), the light receiving means includes an optical transistor, the output unit includes a transistor, and the emitter of the optical transistor is connected to the base of the transistor. And a Darlington connection in which the collector of the phototransistor is connected to the collector of the transistor.
According to the switching device ( 3 ), the current amplification factor is increased and good switching characteristics can be realized.
[0020]
The switching device ( 4 ) according to the present invention is characterized in that, in any of the switching devices (1) to ( 3 ), the switching device is used as an emergency stop switching device. It is said.
According to the switching device ( 4 ), not only can the external device be stopped in an emergency by stopping the circuit in an emergency, but also the presence or absence of an emergency stop signal can be determined. It becomes possible to monitor the state of the apparatus.
[0021]
The portable operating device (1) according to the present invention is connected to an external device, receives display means for displaying status information related to the external device, and input information for operating the external device, and receives the input information from the external device. In the portable operating device including the input transmission means for transmitting to the input device, the input transmission means includes any one of the switching devices (1) to ( 4 ).
According to the portable operating device (1), it is possible to monitor the state of the switching device for emergency stop while keeping the cost low without changing the size of the portable operating device. The control system can be strengthened.
[0022]
In the present invention, a mechanical NC contact refers to an NC contact that operates mechanically with physical displacement, and a switching mechanism refers to an assembly of these mechanical NC contacts.
The potential fixing portion refers to a portion for applying a potential to the circuit, and refers to a portion connected to a power source or a portion grounded. Further, in the circuit connection, various electric resistances, capacitors and the like can be supplemented as long as the operation of the present invention is not hindered.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments according to the present invention will be described below in detail with reference to the drawings.
[0024]
FIG. 1 is a schematic diagram illustrating a configuration of a switching device including three contacts according to an embodiment. As shown in FIG. 1, the three-contact switching device according to the embodiment of the present invention includes three mechanical NC contacts 40 that operate mechanically and output NC signals independently of each other. NC signal output from the selected mechanical NC contact 10 connected to the switching mechanism 13 provided and one mechanical NC contact (hereinafter referred to as a selected mechanical NC contact) 10 of the three mechanical NC contacts 40 Switching signal inverting means 11 for inverting the signal to NO signal and outputting it. A contact (hereinafter referred to as a conversion contact) 12 constituted by the selected mechanical NC contact 10 and the switching signal inverting means 11 operates as a NO contact.
[0025]
According to the three-contact switching device according to the embodiment, the mechanical NC contact 40 and the selected mechanical NC contact 10 are mechanically interlocked, and the consistency between the mechanical NC contact 40 and the conversion contact 12 is satisfied. Can be kept easily. Therefore, the switching device according to the embodiment can sufficiently ensure reliability even when used as an emergency stop switching device. It should be noted that the number of NC contacts and the number of NO contacts need only be one or more, and can be variously changed depending on the application.
[0026]
Further, according to the switching device according to the embodiment, it is not necessary to mix the mechanical NC contact 40 and the mechanical NO contact 41, and an inexpensive switching mechanism manufactured to have only a plurality of mechanical NC contacts. By using 13, it is possible to keep the manufacturing cost low even if the cost of the switching signal inverting means 11 is added.
[0027]
FIG. 2 is a circuit diagram more specifically showing a preferred embodiment of the conversion contact 12 shown in FIG. As described above, the conversion contact 12 includes the selected mechanical NC contact 10 and the switching signal inverting means 11.
[0028]
As shown in FIG. 2, the switching signal inverting means 11 is connected to one end of the selected mechanical NC contact 10 and has a first potential fixing portion 21 that applies a first potential, a second potential fixing portion 22, , An inversion unit 20, an optical signal transmission unit 24, a third potential fixing unit 23, and an output unit 25. An inverter is preferably used as the inversion unit 20, and a photocoupler is preferably used as the optical signal transmission unit 24.
[0029]
Here, the first potential fixing unit 21 is connected to one end of the selected mechanical NC contact 10 to give a first potential, and the second potential fixing unit 22 is connected to the selected mechanical NC via an electric resistance. Connected to the other end of the contact 10, a second potential is applied. Here, an L level potential grounded is assumed as the first potential, and an H level potential is assumed as the second potential. As the H level, a potential of about 5 V is preferably applied.
[0030]
The inverting unit 20 has an input end and an output end, receives a potential at the input end (hereinafter referred to as an input potential) from the input end connected to the other end of the selected mechanical NC contact 10, and inputs the output to the output end. A potential obtained by inverting the potential (hereinafter referred to as an inverted output potential) may be output, which is realized by a normal inverting circuit.
[0031]
The photocoupler 24 as an optical signal transmission unit includes a light emitting element 26 and a light receiving element 27 that are electrically insulated from each other. The light emitting element 26 changes its light emission state by the potential difference between the potential at one end of the light emitting element 26 connected to the output end of the inverting unit 20, that is, the inverted output potential, and the potential at the other end of the light emitting element 26. The light receiving element 27 senses the light emission state and outputs a signal. As a result, the photocoupler 24 outputs a signal from the light receiving element 27.
[0032]
The third potential fixing unit 23 is connected to the other end of the light emitting element 26 and applies a third potential. Here, an H-level potential is assumed as the third potential. The light emitting element 26 is realized by a light emitting diode or the like, and the light receiving element 27 is realized by an optical transistor, a photodiode or the like.
[0033]
In this way, the operation of the light emitting element 26 can be controlled by the potential difference between the output terminal of the inverting unit 20 and the third potential, and the light receiving element 27 senses the light emission state and outputs a signal. It becomes possible to output. The output unit 25 receives the signal and outputs a NO signal based thereon.
[0034]
Normally, since the selected mechanical NC contact 10 is closed, the input potential becomes L level and the inverted output potential becomes H level. At this time, both ends of the light emitting element 26 are at the H level, and the light emitting element 26 does not emit light at all or does not emit light to the extent that the light receiving element 27 recognizes it as a signal. Therefore, the light receiving element 27 is not normally photoactivated, and both ends thereof are separated, so that the output unit 25 outputs a signal indicating an open state.
[0035]
On the other hand, since the selected mechanical NC contact 10 is opened in an emergency, the input potential becomes H level and the inverted output potential becomes L level. At this time, a potential difference is generated between both ends of the light emitting element 26, the light emitting element 26 emits light, and the light receiving element 27 is normally photoactivated, so that the output unit 25 outputs a signal indicating a closed state.
[0036]
As described above, the output unit 25 outputs a signal indicating the open state at the normal time and outputs a signal indicating the closed state in an emergency, which means that the NO signal is output, and the conversion contact 12 serves as a NO contact. When the output unit 25 outputs a NO signal, it is desirable to amplify the signal.
[0037]
FIG. 2 shows an example of a circuit when the light receiving means includes an optical transistor and the output unit includes a transistor. At this time, it is desirable that a Darlington connection is made in which the emitter of the phototransistor is connected to the base of the transistor and the collector of the phototransistor is connected to the collector of the transistor, thereby increasing the current amplification factor and good switching. Characteristics are realized. A capacitor between the phototransistors is installed to remove noise and improve the rising and falling characteristics.
[0038]
FIG. 3 is a diagram conceptually showing an environment in which a portable operating device using a switching device with three contacts (2NC / 1NO) according to an embodiment of the present invention is used. As shown in FIG. 3, the portable operating device 30 is connected to the external device 34 and receives display means 31 for displaying status information 100 related to the external device 34 and input information 110 for operating the external device 34. And input transmission means 32 for transmitting the input information 110 to the external device 34. The input transmission means 32 is equipped with the switching device 33 described above. Hereinafter, the case where the switching device 33 is used as a switching device for emergency stop will be described.
[0039]
The external device 34 is roughly classified into a processing unit 35 that performs processing in the manufacturing process of the external device 34 and an emergency operation unit 36 that operates in an emergency. Then, the switching device 33 outputs two independent NC signals 130 to the processing unit 35 and further outputs one independent NO signal 140 to the emergency operation unit 36.
[0040]
As a result, the emergency operation unit 36 is normally opened and stopped by the NO signal 140, but is closed and operated in an emergency to transmit the related information 120 to the related equipment 37. . In addition, as related equipment 37, safety is ensured when an external device 34 such as an alarm device, an external device 34 linked with an external device 34 such as a transport device, or a gas valve shut-off device is stopped. For example.
[0041]
As described above, according to the switching device according to the embodiment, the mechanical linkage between the NC contact and the NO contact can be improved, and the consistency between the NC signal and the NO signal can be easily maintained. It is also possible to produce an excellent effect that can reduce the manufacturing cost.
[0042]
Further, according to the portable operating device using the switching device according to the embodiment of the present invention, the emergency operating device conforming to the safety standard can be achieved while keeping the cost low without changing the size of the portable operating device. it becomes possible to monitor the state of the switching device, it is possible to enhance the control system of the production line.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a configuration of a switching device having three contacts according to an embodiment.
FIG. 2 is a circuit diagram more specifically showing a preferred embodiment of the conversion contact shown in FIG. 1;
FIG. 3 is a diagram conceptually showing an environment in which a portable operation device using a switching device with three contacts (2NC / 1NO) according to an embodiment of the present invention is used.
FIG. 4 is a schematic diagram showing a configuration of a switching device with three contacts (2NC / 1NO) according to the prior art.
[Explanation of symbols]
10 Selected mechanical NC contact
11 Switching signal inversion means
12 Conversion contact
13 Switching mechanism
40 Mechanical NC contact
42 Insulating connection

Claims (5)

Operates mechanically and outputs switching signals (hereinafter referred to as NC signals) of normally closed contacts (hereinafter referred to as NC contacts) independently of each other, at least three mechanical It is connected to a switching mechanism having a normally closed contact (hereinafter referred to as a mechanical NC contact) and at least one mechanical NC contact (hereinafter referred to as a selected mechanical NC contact) among the mechanical NC contacts. Switching signal inversion means for inverting the NC signal output from the mechanical NC contact to a normally open (NO) contact signal (hereinafter referred to as NO contact) switching signal (hereinafter referred to as NO signal) And the switching signal inversion means is constituted by means that is electrically insulated . The switching signal inversion means includes an input end and an output end, and receives a potential at the input end (hereinafter referred to as an input potential) from the input end connected to the other end of the selected mechanical NC contact; An inverting unit that outputs a potential obtained by inverting the input potential (hereinafter referred to as an inverted output potential) to the output end, the inverted output potential at one end connected to the output end of the inverting unit, and the other end Optical signal transmission provided with a light emitting means for changing a light emitting state according to a potential difference between the electric potential and a light receiving means which is electrically insulated from the light emitting means and senses the light emitting state of the light emitting means and outputs a signal The switching device according to claim 1 , further comprising: an output unit that receives the signal and outputs the NO signal based on the signal. The light receiving means includes an optical transistor, the output unit includes a transistor, the emitter of the optical transistor is connected to the base of the transistor, and a Darlington connection is made in which the collector of the optical transistor is connected to the collector of the transistor. The switching device according to claim 2, wherein: The switching device, the switching device according to any one of claims 1-3, characterized in that is used as a switching device for emergency stop. A portable device that is connected to an external device and includes display means for displaying status information related to the external device, and input transmission means for receiving input information for operating the external device and transmitting the input information to the external device A portable operation device, wherein the input transmission means includes the switching device according to any one of claims 1 to 4 .

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