JPS6050304B2 - Electromagnetic drive circuit failure diagnosis device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electromagnetic drive circuit failure diagnosis device for detecting the presence or absence of a failure in an electromagnetic drive circuit system that operates an electromagnetic actuator in accordance with a control input signal.

Electromagnetic drive circuit systems configured to operate electromagnetic actuators including solenoids, relays, etc. according to control input signals are applied in a wide range of fields, but electromagnetic actuators require particularly large drive currents. In such cases, the coils that make up the electromagnetic actuator,
It is said that there is a relatively high possibility that drive circuit elements such as transistors and integrated circuits that constitute a drive circuit for operating an electromagnetic actuator will be damaged.

Furthermore, failures in the electromagnetic drive circuit system due to damage to these coils or drive circuit elements may lead to serious accidents in some cases. Therefore, it is necessary to discover failures in the electromagnetic drive circuit system as early as possible and take appropriate measures against it, but for this purpose, it is necessary to diagnose whether or not there is a failure in the electromagnetic drive circuit system from time to time.

At this time, it is possible to diagnose even if the electromagnetic drive circuit system is in a state where it can immediately operate the electromagnetic actuator upon receiving a control signal (hereinafter referred to as 1 operating state of the electromagnetic drive circuit system). It is desirable that the operating function of the electromagnetic drive circuit system not be impaired in the process, that is, that the electromagnetic actuator should not malfunction, but conventionally there has been no suitable device that satisfies these conditions. In view of the above-mentioned circumstances, the present invention provides an electromagnetic drive system in which the presence or absence of a failure in an electromagnetic drive circuit system can be diagnosed without impairing its operating function even if the electromagnetic drive circuit system is in an operating state. The purpose of this invention is to obtain a circuit failure diagnosis device.

An embodiment of the present invention will be described below with reference to the drawings. First, in FIG. 1, an electromagnetic drive circuit system 1 includes a drive circuit 5 whose input side is connected via an adder 4 to an input contact 3 for receiving a control signal A sent from a control signal generation source (not shown); The electromagnetic actuator 7 has one end connected to the output side of the drive circuit 5 via a contact 6, and the other end connected to an anode power supply 8. In FIG. 1, the drive circuit 5 is illustratively a single transistor whose base is connected to the input contact 3 side, whose collector is connected to the electromagnetic actuator 7 side, and whose emitter is grounded. 9, and the electromagnetic actuator 7 is shown as having an electromagnetic coil. Therefore, when the control signal A is sent, a drive current is caused to flow through the electromagnetic actuator 7, and at this time, the drive current forms a potential waveform signal A'' which is an inversion of the control signal A.

Next, the failure diagnosis device 2 will be explained.

A pseudo signal oscillator 10 provided separately and independently from the control signal generation source includes a signal discrimination circuit 1 constituted by an adder 4 and an EX-0R circuit forming an exclusive OR circuit.
1 input side, and its . A pseudo signal B, which is an output signal, is sent to the input side of the drive circuit 5 and the signal discrimination circuit 11, respectively. Pseudo signal B is
An example is a rectangular wave signal as shown in FIG. 2 having a frequency within a frequency range that does not affect the response function of the electromagnetic actuator 7 to the control signal A. Generally, the response frequency characteristic of the electromagnetic actuator 7 to the control signal A is not very high, so the pseudo signal B has a frequency sufficiently higher than the response frequency of the electromagnetic actuator 7.
is sent to the drive circuit 5, depending on the output current generated in response to this pseudo signal oscillator B, the electromagnetic actuator 7
doesn't work. The input side of the signal discrimination circuit 11 constituted by the EX-0R circuit is connected to the pseudo signal oscillator 10 and also to the contact 6, and the output side thereof is connected to the alarm 12 connected in series with the protective resistor R. connected to the input side of the Therefore, the signal discrimination circuit 11 receives the pseudo signal B directly from the pseudo signal oscillator 10, receives the potential waveform signal B'' which is an inverted form of the pseudo signal B from the contact 6, and outputs the output signal C. occurs and sends it to the alarm 12. Fig. 2 1 shows the state when the electromagnetic drive circuit system 1 is normal.
The waveforms of the potential waveform signal B'' based on the pseudo signal B1 and the output signal C are schematically shown.

The potential waveform signal B'' based on the pseudo signal B has a waveform that is an inversion of the pseudo signal B, and the output signal C is always constant due to the action of the EX-0R circuit that constitutes the signal discrimination circuit 11. If the electromagnetic drive circuit system 1 fails and the contact 6 is always at a constant power supply potential regardless of the control signal A, then As shown, the output signal C of the signal discrimination circuit 11 is the pseudo signal B.
A waveform signal with the inverted state is formed.

In such a case, there may be a break in the drive circuit 5 or a short circuit in the electromagnetic actuator 7, for example. Similarly, electromagnetic drive circuit system 1 has failed, and contact 6 is closed regardless of control signal A.
When is always at the ground potential, the output signal C of the signal discrimination circuit 11 forms a waveform signal having the same phase as the pseudo signal B, as shown in FIG.

In such a case, for example, a short circuit in the drive circuit 5 or a disconnection in the electromagnetic actuator 7 may occur. In any case, the waveform of the output signal C of the signal discrimination circuit 11 when the electromagnetic drive circuit system 1 is malfunctioning is the same as the waveform of the output signal C of the signal discrimination circuit 11 when the electromagnetic drive circuit system 1 is operating normally. Since it can be clearly identified compared to the waveform of C, it is easy to detect a failure in the electromagnetic drive circuit system 1.

When the output signal C of the signal discrimination circuit 11 forms a waveform signal as shown in FIG. can be detected with certainty. At this time, the alarm device 12 may be, for example, an alarm pump. Also,
As shown by the dotted line in FIG. 1, if connecting a small capacitor 13 in parallel to the electromagnetic coil of the electromagnetic actuator 7 does not affect the original operating characteristics of the electromagnetic actuator 7, the electromagnetic coil and the capacitor By tuning the parallel circuit with 13 to the pseudo signal B having a frequency sufficiently higher than the response frequency of the electromagnetic actuator 7, a larger, more accurate, and more stable output signal can be obtained as the output signal of the drive circuit 5. Therefore, it is more accurate and stable than the output signal C of the signal discrimination circuit 11. When the pseudo signal B, which is the output signal of the pseudo signal oscillator 10, is a sine wave and the drive circuit 5 is operated in a non-saturation region, a sine wave signal is obtained as the output signal of the drive circuit 5. Before sending this signal to the signal discrimination circuit 11, it is first converted into a waveform-shaped rectangular wave, and then the signal discrimination circuit 11
Failure diagnosis processing can be performed more accurately if the information is sent to

Furthermore, a low-pass filter may be interposed at the output terminal portion of the signal discrimination circuit 11 in order to remove short-time minute fault signals generated as an output signal from the signal discrimination circuit 11.

As described above, according to the present invention, the electromagnetic actuator 7
, receives control signal A as an input signal, and receives control signal A as an input signal.
An electromagnetic drive circuit failure diagnosis apparatus for detecting the presence or absence of a failure in an electromagnetic drive circuit system 1 comprising a drive circuit 5 that generates a drive current for driving the electromagnetic actuator 7 in response to the electromagnetic actuator 7; A pseudo signal B having a frequency within a frequency range that does not affect the response function of the electromagnetic actuator 7 to the control signal A can be generated, and the pseudo signal B can be sent to the input side of the drive circuit 5. a pseudo signal oscillator 10 independent from the signal generation source of the control signal A, configured as follows;
When the electromagnetic drive circuit system 1 receives an output signal generated by the drive circuit 5 based on the pseudo signal B sent from 0 and the pseudo signal B as input signals, and a failure occurs in the electromagnetic drive circuit system 1,
Since the electromagnetic drive circuit system 1 has a signal discrimination circuit 11 that generates an abnormal signal as an output signal that can be distinguished from an output signal when it is operating normally, the pseudo signal B
By simply manually inputting the above-mentioned pseudo signals to the electromagnetic drive circuit system 1, it is possible to immediately diagnose the presence or absence of a failure in the electromagnetic drive circuit system 1 based on the output signal of the signal discrimination circuit 11 generated accordingly. Since signal B has a frequency within a frequency range that does not affect the response characteristics of the electromagnetic actuator 7 to the control signal, there is no fear that the electromagnetic actuator 7 will malfunction even if the pseudo signal B is input. , Therefore, even if the electromagnetic drive circuit system 1 is in operation,
It is possible to accurately and accurately diagnose the presence or absence of a failure at any time.

In addition, since control signal A is not essential for fault diagnosis, there is no need to specially set operating conditions that generate control signal A for fault diagnosis, making fault diagnosis work extremely simple and quick. 7.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram of a main part showing an example of an electromagnetic drive circuit system and an electromagnetic drive circuit diagnostic device based on the present invention connected to the electromagnetic drive circuit system, and Fig. 2 shows a pseudo signal for failure diagnosis and a drive device. FIG. 3 is a waveform diagram schematically showing the output signal of the electromagnetic drive circuit system and the output signal of the signal discrimination circuit, divided into the normal state and the fault state of the electromagnetic drive circuit system. 1... Electromagnetic drive circuit system, 5... Drive circuit, 7... Electromagnetic actuator, 10...
...Five pseudo signal oscillators, 11...Signal discrimination circuit, 12...Alarm, A...Control signal, B...
...pseudo signal.

Claims (1)

[Scope of Claims] 1. Comprising an electromagnetic actuator 7 and a drive circuit 5 that receives a control signal A as an input signal and generates a drive current for driving the electromagnetic actuator 7 in response to the control signal A. In the electromagnetic drive circuit failure diagnosis device for detecting the presence or absence of a failure in the electromagnetic drive circuit system 1, the electromagnetic drive circuit has a frequency within a frequency range that does not affect the response function of the electromagnetic actuator 7 to the control signal A. a pseudo signal oscillator 1 independent from the signal generation source of the control signal A, configured to generate a pseudo signal B and send the pseudo signal B to the input side of the drive circuit 5;
0; Pseudo signal B sent from this pseudo signal oscillator 10
When a failure occurs in the electromagnetic drive circuit system 1, the electromagnetic drive circuit system 1 is operating normally. An electromagnetic drive circuit failure diagnosis device comprising at least a signal discriminating circuit 11 that generates an abnormal signal as an output signal that can be distinguished from an output signal at a time. 2. The electromagnetic drive circuit failure diagnosis apparatus according to claim 1, wherein the signal discrimination circuit 11 is an EX-OR circuit forming an exclusive OR circuit. 3. In the electromagnetic drive circuit failure diagnosis device according to claim 1, the electromagnetic drive circuit failure diagnosis device includes an alarm device 12 that generates an alarm when the signal discrimination circuit 11 generates the abnormal signal as an output signal. An electromagnetic drive circuit failure diagnosis device equipped with