JPS5827870B2 - Failure detection device for detectors in electrical equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a failure detection device for a detector in electrical equipment such as a freight car acceleration/deceleration device, an unmanned running trolley, and a crane, and more particularly to a device for preventing malfunction of a failure detector.

The freight car acceleration/deceleration device is constructed, for example, as shown in FIGS. 1a and 1b.

In this figure, 1 is a track on which freight cars run, 2 is a freight car detection truck, 3 is a motor car equipped with a running motor, 4 is a control car equipped with a controller that controls the running motor, and 5
is a brake car, 6 is a bumper car, 7 is a power trolley,
8 is a current collector provided on the freight car detection truck 2; 9 is a proximity switch for detecting an incoming freight car also provided on the freight car detection truck 2; 10 is a proximity switch for detecting a halfway stopped freight car provided on the motor car 3; 11. Reference numeral 12 denotes a proximity switch for detecting the speed of the approaching freight car provided on the control car 4, and 13 a proximity switch for detecting the freight car and measurement interval provided on the brake car 5.

Reference numerals 14 and 15 denote acceleration and deceleration buttons provided on the pusher car 6, which extend onto the track on which the freight car runs when necessary to push the wheels of the freight car.

Work on the sorting line using this freight car acceleration/deceleration device is performed as follows.

That is, as shown in FIGS. 2 and 3, the arrival line R
1, automatically protrudes from Oshiage line R2 and reaches the sorting line R.
When the freight car acceleration/deceleration device 17 waiting at the entrance of the sorting lines R3 to R9 catches the freight car 16a approaching at a speed of about 10±5 b/h from 3 to R9, the freight car and the freight car acceleration/deceleration device temporarily The running motor is controlled on and off, and the vehicle rolls at a speed of about 13 to 15 b/h while repeating running and coasting.
When the distance to the freight car 16c stopped at the stop position reaches a predetermined value L (approximately 50 m), it begins to decelerate, and when it decelerates to 5 kb, the freight car is released, only the freight car acceleration/deceleration device is reversed, and the freight car starts running again. 13 while controlling the motor on and off.
Return to the entrance of the sorting line at a speed of ~15Ax/h and prepare for the next freight car to enter.

This operation is repeated until the sorting line is full of freight cars.

In FIG. 2, 18 is a locomotive for pushing up freight cars or a freight car adjustment device, 16b is a freight car in the middle of transfer, and in FIG. 3,
The solid line shows the operating characteristics of the freight car (including when it is used together with the freight car acceleration/deceleration device), the dashed line shows the driving characteristics of the acceleration/deceleration device, and the dash-dotted line shows the behavior when the freight car acceleration/deceleration device encounters a freight car on its way back to the entrance of the sorting line. It is a driving characteristic.

As described above, since the freight car acceleration/deceleration device includes a plurality of proximity switches and performs automatic operation using these switches, if the proximity switch fails, automatic operation will not be performed normally.

Therefore, a failure detection circuit for detecting a failure of the proximity switch is generally provided.

FIG. 4 is an electrical circuit diagram of a freight car adjustment device equipped with a conventional failure detection circuit of this type.

In this figure, the same reference numerals as in FIG. 1 indicate the same or equivalent parts.

Further, 19 is an electromagnetic contactor for connecting the driving motor 20 to a power source, 21 is a speed generator, and 22 is a control logic circuit, which outputs the speed signal from the speed generator 21 and the output from each proximity switch 9 to 13. Input signals I to H, make various judgments based on these signals, turn on the electromagnetic contactor 19, etc.
It is turned off and the freight car acceleration/deceleration device 11 is automatically controlled as shown in FIG.

For example, when the output of the control logic circuit 22 becomes "09+", this output "O" is inverted by the NAND gate 23 and becomes lTl, which is amplified by the amplifier 24 and flows to the excitation coil of the electromagnetic contactor 19. , put in the electromagnetic contactor 19,
The traveling motor 20 is driven.

Further, 25 is a failure detection circuit, and flip-flops 26 to 25 are failure detection circuits.
30 and NAND gates 31-35.

That is, it is known that the proximity switches 9 to 13 detect objects sequentially from left to right only in the forward direction in FIG. 3, and that in the backward direction there is no detected object and the proximity switches do not operate. In this case, first input the output of the proximity switch 9 to the flip-flop 26, set the S side output of the flip-flop 26 to 0, and then
When 0 operates, its output is input to the flip-flop 27, and the R side output of the flip-flop 27 becomes "1".
Make it.

Therefore, when the proximity switches 9 and 10 are operating normally, the output of the NAND gate 131 remains at 1''.

However, if the proximity switch 9 is off and malfunctions, the S side output of the flip-flop 26 will be 1''.
As mentioned above, the proximity switch 1
0 operates and the R side output of the flip-flop 27 becomes "1".
'', the power of the two NAND gates 31 is 1.
'', and its output becomes ff OFP.

In other words, when the output of the NAND gate 31 becomes O'', it is possible to detect an off-state failure in the proximity switch 9.

In the same manner, it is possible to detect an off-state failure in each proximity switch.

However, in order to detect a failure in the proximity switch 13 located at the rearmost position, since there is no proximity switch to operate next, a signal is supplied from the control logic circuit 22 to the NAND gate 35 instead.

The signal from this control logic circuit 22 is passed to the NAND gate 35.
The timing to apply the signal to the proximity switch 12 can be given after a certain period of time after the proximity switch 12 is activated, or when the proximity switch 1 is applied in sequence after the proximity switch 12 is activated.
There are methods for giving when 3 should be turned on, and it is sufficient to select one of these that is suitable for the control method.

Regarding failure detection when the proximity switch is on,
During the return operation of the freight car adjustment device, the proximity switch is activated for a predetermined time (
This can be easily dealt with by determining a failure when it is turned on continuously (approximately 6 seconds).

Further, when the proximity switch malfunctions, an erroneously generated detection signal is input to the control logic circuit, but this is dealt with, for example, as follows.

(1) Regarding the proximity switch 9, it is impossible in principle to prevent an erroneous detection signal from entering the control logic circuit, and this is dealt with by adjusting the sensitivity of the metal roach and absorbing it by a buffer.

(2) Regarding the proximity switches 10 to 13, even if an erroneously generated detection signal is input to the control logic circuit during the return operation of the freight car acceleration/deceleration device, this can be handled by ignoring the signal while energized.

(3) The detection signals from the proximity switches 10 to 12 are required when catching a freight car, but since the freight car acceleration/deceleration device is not energized at this time, the detection signals generated when energized can be ignored. .

(4) The proximity switch 13 cannot ignore the energized detection signal only at fixed times on the freight car length side.

However, the erroneously generated detection signal at this time fortunately does not result in an error in the length of the freight car.

In other words, even if an erroneous signal occurs, it only means that there is another imaginary wheel between the wheels, and in principle it does not result in an error in measuring the freight car length.

By the way, in such a freight car acceleration/deceleration device, as described above, since the power trolley 7 is disposed close to the proximity switches 9 to 13, the traveling motor 20 of the freight car acceleration/deceleration device is driven. When a load current as shown in FIG. 5a flows, a high frequency current as shown in FIG. A high frequency magnetic field H is generated, and this magnetic field H affects nearby proximity switches, causing them to malfunction.

As a result, the operating order of the proximity switches becomes out of order, and a normal proximity switch is mistakenly determined to be faulty.

SUMMARY OF THE INVENTION An object of the present invention is to provide a failure detection device for a detector in an electrical device that can always perform accurate failure detection without determining that the detector is malfunctioning when the detector malfunctions due to a noise source. be.

In order to achieve this object, the present invention is characterized in that the failure detector is made effective only when the noise source of the electrical equipment is isolated, that is, when the detector does not malfunction.

An embodiment of the present invention will be described below with reference to FIG.

In FIG. 6, the same reference numerals as in FIG. 4 indicate the same or equivalent parts.

The difference from the conventional example shown in FIG. 4 is that when the control logic circuit 22 issues a command to turn off the electromagnetic contactor 19, this command signal is input to the NAND gates 37 to 41 via the timer 36, and the proximity switch 9 -13 signals can be taken out, and the outputs of NAND gates 37-41 are input to flip-flops 26-30 via inverters 42-46, but the other configurations are exactly the same.

The reason for providing the timer 36 here is that even if the command to turn off the magnetic contactor 19 is issued, the load current has not yet become zero, so when the load current becomes completely zero, the NAND gates 37 to 41
This is so that the signals of the proximity switches 9 to 13 can be input to the failure detection circuit 25 by giving a command signal to the proximity switches 9 to 13.

Further, inverters 42 to 46 are connected to NAND gates 37 to 4.
By adding 1, the signals of the proximity switches 9 to 13 are inverted, so this is to restore them to their original state.

Turn-on command II of the electromagnetic contactor 19 from the control logic circuit 22
When OP+ is being output, the electromagnetic contactor 19 is turned on as described above, and the travel motor 20 is driven.

On the other hand, this ON command "OI+" is sent to NA via the timer 36.
Since it is also input to the ND gates 31 to 41, even if the proximity switches 9 to 13 operate and their output signal becomes 1'',
The outputs of the NAND gates 37-41 remain N1P+, and 011 remains input to the flip-flops 26-30.

That is, when the traveling motor 20, which is a noise source, is driven and there is a risk of erroneous failure detection, the operation signals of the proximity switches 9 to 13 are not taken into the failure detection circuit 25, and no failure detection operation is performed. .

However, when the control logic circuit 22 outputs the off command "1" for the electromagnetic contactor 19 and the driving motor 20 is disconnected from the power supply, one input of the NAND gates 37 to 41 is "1". , proximity switches 9-13
operates and its output signal becomes "1", the outputs of the NAND gates 37-41 become "0", "1" is input to the flip-flops 26-30, and the proximity switch as described above The off-state failure detection operation is performed in the off-state.

In other words, the operating signal of the proximity switch is taken into the failure detection circuit 25 and the failure detection operation is performed only when the traveling motor 20, which is the noise source, is disconnected from the power supply and there is no risk of false failure detection. become.

Note that in the above embodiment, the traveling motor 20, which is a noise source,
The electromagnetic contactor off command from the control logic circuit 22 detects a state in which the electromagnetic contactor is disconnected from the power supply and there is no risk of false failure detection. It can also be detected by a signal from a contact, or by the fact that the load current has become zero.

As explained above, according to the present invention, the failure detector is enabled only when the noise source of the electrical equipment is disconnected from the power supply, that is, when the detector does not malfunction, so the noise source causes the detector to malfunction. In this case, the detector is not judged to be malfunctioning, and accurate malfunction detection can always be performed.

[Brief explanation of drawings]

Figures 1a and b are top and side views showing the schematic configuration of the freight car acceleration/deceleration device, Figure 2 is an explanatory diagram showing the arrangement of the freight car acceleration/deceleration device in the freight car operation field, and Figure 3 is a diagram showing the freight car and the freight car acceleration/deceleration device. An explanatory diagram showing the operating characteristics of the deceleration device, Fig. 4 is an electric circuit diagram of a freight car acceleration/deceleration device equipped with a conventional failure detection circuit, and Fig. 5a
, b are waveform diagrams of the load current flowing through the power trolley and the high-frequency current contained in this load current, and FIG. FIG. 3 is an electrical circuit diagram of the device. 7...Power trolley, 9-13...
Proximity switch, 19...Magnetic contactor, 20...
... Traveling motor, 22..., ... Control logic circuit,
25...Failure detection circuit, 26-30...
Flip-flop, 31~35°37~41...
・NAND gate, 36... Timer 42-46
...Inverter.

Claims (1)

[Scope of Claims] 1. An electric device comprising: an electric device; a detector that controls the operation of the electric device based on its output; and a failure detector that detects a failure of the detector during operation of the electric device, A failure detection device for a detector in an electrical device, characterized in that the device includes means for activating the failure detector only when a noise source of the electrical device is disconnected from a power source. 2. In claim 1, the electric device is an electric vehicle, and the failure detector is enabled when the electric vehicle is in a coasting state with the drive source of the electric vehicle being disconnected. A failure detection device for a detector in an electrical device, characterized by: 3. In claim 2, the electric vehicle is a freight car acceleration/deceleration device in which seven drive sources are controlled to turn on and off based on the output of the detector, and when the seven drive sources are off, the failure detection is performed. 1. A failure detection device for a detector in electrical equipment, characterized in that the detector is enabled.