JPH0422109A - Electromagnet device - Google Patents

Abstract

PURPOSE:To always perform a proper attracting operation by a method wherein abnormal detecting means for detecting presence or absence of abnormality of each electromagnet upon the attracting operation and controlling means for changing a supplying time of an operating current based upon signals derived from the abnormal detecting means are provided. CONSTITUTION:In a case where both of electromagnets 1 and 2 are normal, by the AND condition of this signal input, an input pulse part 5 stops an input pulse voltage V2 from a lapse of a delay time t. This delay time t rather substantiates the input of the electromagnets 1 and 2. In addition, if either of electromagnet 1 or 2 do not complete attracting operation due to damage by a fire or disconnection of a coil 7, an input pulse width is set to TP2 due to miscarriage of the above-mentioned AND condition. Thereafter, when a switch 3 is turned OFF and an input voltage Vin gradually descends, an output voltage V1, accordingly a holding pulse voltage V3, is stopped at a predetermined level to restore the electromagnets 1 and 2 into an unoperated state.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to an electromagnet device used in various drive mechanisms, for example, the operation mechanism of a high-voltage electromagnetic switch, and more particularly to an electromagnet device including a plurality of electromagnets connected in parallel.

[Conventional technology]

Generally, when driving an electromagnet, a relatively large operating current is required during the attraction operation, but after the attraction is completed, it is only necessary to supply a smaller holding current (Japanese Patent Application Laid-Open No.
0-116950). On the other hand, in order to ensure the reliability of the electromagnet device, two electromagnets are connected in parallel and used, so that even if one electromagnet fails, the other electromagnet can perform the operation. FIG. 6 is a connection diagram of such a conventional electromagnet device whose drive circuit is constituted by an electronic circuit, and includes two electromagnets 1 and 2 (the drive circuit is included and not shown).
are connected in parallel and connected to a power supply via a common switch 3. A method of driving such an electromagnet device will be explained below with reference to the block diagram of the drive circuit shown in FIG. 7 and the voltage waveform diagram shown in FIG. 8. When the input voltage V Ln gradually rises, the voltage detection section 4 operates at a predetermined level, and a voltage of (2) is outputted from this. Using this vl as input, the electromagnets 1 and 2 are connected to the input pulse section 5.
The pulse pressure ■ necessary for the suction operation is output. This pulse voltage (2) is applied to the coil 7 of the electromagnet 1.2 via the holding pulse section 6, and a suction operation is performed. Furthermore, at the same time as the output voltage (2) stops, a holding pulse (3) is applied from the holding pulse unit 6 to the coil 7, and a holding operation is performed.

[Problem to be solved by the invention]

By the way, the supply time of the operating current necessary for the attracting operation of the electromagnet, that is, the input pulse width TP in Figure 8, is the operating characteristic diagram in Figure 9 (the horizontal axis is the power supply voltage, and the vertical axis is the input pulse width T).
As shown in P), the number of electromagnets 1.2 is smaller than that of two.
It will be longer in the case of individual pieces. This is because when the electromagnets are operated on the same object, the load per electromagnet increases as the number of electromagnets decreases. Therefore, even in an electromagnet device using two electromagnets as shown in Figure 6, conventionally, the input pulse width TP is set to match the case where one electromagnet is used, taking into consideration the case where one electromagnet fails. Ta. However, this applies unnecessary power to the electromagnet during normal operation, and in electromagnetic devices that are operated frequently, the coil may overheat and burn out. This invention was made in view of this situation,
An object of the present invention is to provide an electromagnet device that uses a plurality of electromagnets connected in parallel and that can always supply an appropriate operating current.

[Means to solve the problem]

In order to achieve the above object, the present invention includes an abnormality detection means for detecting the presence or absence of an abnormality in each electromagnet during a suction operation, and a control means for changing the supply time of operating current based on a signal from the abnormality detection means. shall be established. ] The abnormality detection means determines whether each electromagnet is normal or abnormal during suction operation, for example! When there are two magnets, if both of the electromagnets are normal, the supply time TP is controlled using the characteristics E and +Ez shown in FIG. 9, and when one is out of order, the supply time TP is controlled using the same characteristics <E or E2.

【Example】

Figures 1 to 3 show a first embodiment of the present invention in which there are two 1i magnets. Figure 1 is a connection diagram, Figure 2 is a block diagram of the drive circuit, and Figure 3 is a block diagram of the drive circuit. It is a voltage waveform diagram. Note that parts corresponding to those in the conventional example are given the same reference numerals, and descriptions of substantially the same items will be omitted. In this embodiment, a sensor is used to confirm whether or not the attracting operation of the electromagnet is completed, and the supply time of the operating current is determined depending on the presence or absence of an abnormality. That is, a pulse shortening terminal 8 is provided in the input pulse part 5 of each electromagnet 1 and 2, and output contacts 9 and 10 of a photoelectric switch (not shown) for detecting the suction operation of the movable core (not shown) of the electromagnets 1 and 2 are connected to this terminal. has been done. Therefore, when the switch 3 is turned on and the closing pulse voltage V2 is applied to the coil 7 according to the process described in the conventional example, the electromagnets 1 and 2 start the closing operation. When the attraction operation of the electromagnets 1 and 2 is completed, the contacts 9 and 10 are turned on and the pulse shortening signal TP is input to the pulse shortening terminal 8. When both the electromagnets 1 and 2 are normal, the input pulse unit 5 is activated by the delay time t due to the AND condition of this signal input.
After passing through, stop the input pulse voltage ■2. This delay time t is! This is to ensure that the magnets 1 and 2 are inserted more reliably. As a result, the pulse width of voltage ■2 is equal to that of electromagnet 1 or 2.
TP is shorter than the time T P 2 required to perform one suction operation. At the same time as the voltage (2) is stopped, the holding pulse voltage V is outputted from the holding pulse section 6, and the electromagnets 1 and 2 are held. Further, if the suction operation of either tM1 stone 1 or 2 is not completed due to burnout or disconnection of the coil 7, the input pulse width is set to TP2 because the above AND condition is not satisfied. Thereafter, when the switch 3 is turned off and the input voltage V i R gradually drops, the output voltage (1) and therefore the holding pulse voltage (3) are stopped at a predetermined level, and the electromagnets 1 and 2 return to their non-operating state. FIGS. 4 and 5 show a second embodiment of the invention, with FIG. 4 being a connection diagram and FIG. 5 being a voltage waveform diagram. In this embodiment, whether the suction operation is normal or abnormal is determined based on whether the current flowing through the electromagnets 1 and 2 reaches a predetermined level. That is, in FIG. 4, electromagnets 1 and 2
Current detectors 11 and 12 are inserted in series, respectively,
A series circuit of output contacts 13 and 14 that is turned ON when the current passing through them exceeds a predetermined level is connected to each pulse shortening terminal 8. Therefore, the ON AN of contacts 13 and 14
When condition D is satisfied, the pulse shortening signal TP is input to the terminal 8, and the input pulse width becomes TP. Moreover, if it is not established, it becomes TP2. As described above, in any of the embodiments, the appropriate input pulse width TP or T
P is determined, the coil 7 is prevented from being burnt out due to wasteful power supply, and even if the negative electromagnet 1 or 2 fails, the suction operation can be performed without any problem. In addition, although the above embodiment shows the case where there are two electromagnets, three electromagnets are used.
The present invention can also be applied to cases where the number of pulses is more than 1, by finely setting the input pulse width accordingly.

【Effect of the invention】

According to this invention, the 11tf using two or more electromagnets
l! In the L-stone device, by always supplying an appropriate attracting operation current, the reliability of the electromagnetic device Q can be improved, and the coil can be made smaller and power-saving possible.

[Brief explanation of drawings]

Fig. 1 is a connection diagram of the first embodiment of the present invention, Fig. 2 is a block diagram of the drive circuit in Fig. 1, Fig. 3 is a voltage waveform diagram thereof, and Fig. 4 is a diagram of the second embodiment of the invention. Example connection diagram, Figure 5 is a voltage waveform diagram of the drive circuit in Figure 4, Figure 6 is a connection diagram of the conventional example, Figure 7 is a block diagram of the drive circuit in Figure 6, and Figure 8 is the voltage. The waveform diagram, FIG. 9, is a diagram showing the difference in input pulse width between one and two electromagnets. 1.2...electromagnet, 7...coil. Diagram

Claims (1)

[Claims] 1) A plurality of electromagnets connected in parallel to each other, and a drive circuit that supplies an operating current to these electromagnets for a predetermined period of time during a suction operation, and continuously supplies a holding current smaller than the operating current after the suction is completed. An electromagnet device comprising: an abnormality detection means for detecting the presence or absence of an abnormality in each electromagnet during a suction operation; and a control means for changing the supply time of operating current based on a signal from the abnormality detection means. An electromagnetic device.