JPS62276471A - Apparatus for detecting inferior part - Google Patents

Abstract

PURPOSE:To prevent the destruction of a detector due to an erroneous operation, by successively contacting a check pin with an interlock contact subjected to AND connection and making it possible to confirm the operation of an interlock circuit by a pilot lamp. CONSTITUTION:An R-phase connection terminal 2 is connected to the R-phase of the control circuit of a machine tool and a T-phase connection terminal 3 to the T-phase of an interlock contact to be checked. If the interlock contact is in a continuity state, a current flows to a parallel circuit consisting of a resistor, a pilot lamp 6 and a Zener diode 12 by the AC flowing to a route consisting of the check pin 4, a contact 7a, a contact 5a, a resistor 8, a rectifying circuit 10 and the terminal 3 to allow the pilot lamp 6 to light. At this time, even if a resistor for 100V is selected when a power source is 200V by the setting error of a change-over switch, the lamp 6 is protected by the Zener diode 12.

Description

[Detailed description of the invention]

3. Detailed description of the invention

[Industrial application field] The present invention relates to a defect detection device for detecting which interlock contact is activated in a control circuit of an industrial machine. [Conventional technology]

As is well known, in industrial machines such as press machines, interlock contacts are placed between the busbars of the control circuit in series with the operating circuit, and if an abnormality occurs during operation, an interlock contact is activated in response to the abnormal location. It is designed to cut off the power to the operating circuit and perform an emergency stop. If an emergency stop occurs due to activation of an interlock contact during operation, it is necessary to determine which interlock contact was cut off and repair the abnormality before restarting operation. A tester is generally used as a defect detection device for such a purpose, and by checking the conduction state of each contact, the operating location of the interlock contact can be determined.

[Problems to be solved by the invention]

However, since the tester is a general-purpose inspection device that can be used by arbitrarily switching between resistance ranges, voltage ranges, current ranges, etc., when handling the tester, extreme care must be taken when switching the ranges. There is a risk that the device will be destroyed if the range is changed incorrectly due to careless operation.

[Means to solve the problem]

The present invention has been made in view of this serious problem, and aims to provide a novel defect detection device that is less prone to handling errors and allows anyone to easily detect defective locations. In summary, the defect detection device of the present invention comprises: a first power supply terminal 3 connected to one line of the control bus of the device to be detected; and a first power terminal 3 connected to the other line of the control bus of the device to be detected. 2nd@, power supply terminal: a plurality of interlock contacts connected to the second power supply terminal 2 to form an OR logic, and connected together with the operating circuit between the control bus of the detected device; A check pin 4 connected to the one line side at any time: A manual operation contact 7 for selecting either the second power terminal 2 or the check pin 4:
an indicator light 6 that lights up when a control Tfl flow flows between the second power supply terminal 2 or the check pin 4 and the first power supply terminal 3; and: from the manual operation contact to the first power supply terminal. It has a resistance adjustment mechanism that is provided in the circuit and changes the resistance value in the circuit: depending on the lighting state of the pilot lamp when the check pin 4 is connected to any of the interlock contacts. It is possible to check whether or not the interlock contact has operated.

[Function] That is, the defect detection device of the present invention basically connects the parallel circuit of the second power supply terminal and the check pin to the first power supply 5f.
Since the circuit is simply connected in series with the I element, the pilot lamp, and the resistance value adjustment circuit, it is possible to respond to changes in the power supply voltage of the control circuit by simply adjusting the resistance value adjustment circuit and adjusting the circuit resistance. can. Further, if the first power terminal A and the second power terminal are respectively connected to the control bus of the detected device, and the second power terminal A and the second power terminal of the check pins are enabled. The pilot lamp lights up and you can check the pilot lamp itself. Further, the first power terminal is connected to one control bus of the detected device, the second power terminal and the check pin of the check pins are enabled, and the check pin is connected to the interlock of the detected device. By connecting the contact to the one line side, it is possible to detect whether or not the interlock contact has operated based on whether the pilot lamp lights up or not. [Embodiment] An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a plan view showing an example of the external appearance of the defect detection device of the present invention, in which an R-phase connection terminal 2), a T-phase connection terminal 3, and a check pin 4 are each led out from a unit 1 by lead wires. There is. Then, the R-phase connection terminal 2 is connected to the R-in of the control circuit of the press machine and other machine tools, and the connection terminal 3 is connected to the T-in of the control circuit of the machine tool. The pins 4 are connected to the opposite inner sides of the interlock contacts to be checked for continuity in the control circuit. In addition, on the surface of the housing 1, there is a changeover switch 5 for switching between 200V and 100V ranges, a pilot lamp 6 that lights up to indicate the continuity state of the interlock contact that is subject to checking, and a lighting lamp 6 itself. Test buttons 7 for testing the status are arranged as appropriate. Note that the location of these members on the housing 1 is not an important issue for the present invention. Next, FIG. 2 is a circuit diagram showing a specific circuit example of the defect detection device of the present invention.
Reference numerals 5, 6, and 7 indicate the R-phase connection terminal 2, T-phase connection terminal 3, check bin 4, selector switch 5, pilot lamp 6, and test button 7, respectively, which have already been explained in FIG. In addition, in FIG. 2, 8 indicates that the control voltage of the detected device is 200.
A resistor 9 is selected when the control voltage of the detected device is 100V, and a series circuit of the resistor 8 and the contact 5a of the switching switch 5 and a series circuit between the resistor 9 and the switching switch 5 are shown. - The series circuit of the contact 5b of the notch 5 is connected in parallel, and by metering the contact 5a of the changeover switch 5, a resistor 8 for 200V is established, and by metering the contact 5b of the changeover switch 5, a resistor 8 for 100V is established. 9 are each effectively selected. Further, the test button 7 has a B contact 7a and an A contact 7b, the B tI point 7a is connected to the check bin 4, and the A
Contact 7b is connected to R-phase connection terminal 2. Furthermore, in FIG. 2, 10 is a rectifier circuit using a diode bridge, 11 is a shunt resistor, and 12 is a Zener diode for constant voltage, and a forward voltage is applied to the pilot lamp 6. The operating status of the target interlock contact can be checked depending on whether the interlock contact is present or not. Next, the operation of this embodiment will be explained with reference to the above matters and FIG. 3. Incidentally, FIG. 3 is a circuit diagram showing the parts directly related to the present invention extracted from the control circuit of the machine tool in which the operating part of the interlock contact is detected by the defective part detection device of the present invention. ■1 to ■ are interlock contacts, PBI is a run button, PH1 is a stop button, OL is an overload relay, 21 is a relay coil excited by the meter of the run button FBI, and 22 is A that self-holds the relay coil 21. Each contact point is shown, and operation is performed by energizing the relay coil 21. First, in the control circuit of the machine tool shown in FIG. 3, in a normal state, the interlock contacts 11~! , is all made up. Therefore, when the operation button FBI is pressed, the relay coil 21 is excited, self-held by the A contact 22, and operation is started. Then, when the stop button P132 is pressed or any of the interlock contacts (1 to 2) breaks, the relay coil 21 is broken and the operation is stopped. The defect detection device of this embodiment shown in Figs. 1 and 2 is as follows:
The T-phase connection terminal 3 is connected to the T-in of the control circuit, the R-phase connection terminal 2 is connected to the R-in of the control circuit, and the check pin 4 is connected to each interlock contact point (1), ~I. It is used by being connected to any of the interconnection points. In addition, if the power supply for the control circuit of the detected device is 200V, the contact 5a of the changeover switch 5 is made and the voltage is 200V.
In the case of 100V, the contact 5b of the changeover switch 5 is metered and the resistor 9 for 100V is selected. The defect detection device of this embodiment has two operating modes: (1) checking the continuity of the pilot lamp 6 itself, and (2) checking the continuity of each interlock contact. First, when conducting conduction of the (1+ pilot lamp 6 itself), connect the T phase connection terminal 3 and the R phase connection terminal 2 to the After connecting each terminal, press the test button 7 to make contact 7b. Therefore, R phase connection terminal 2 - contact 7b - contact 5a (or contact 5b) - resistor 8 (or resistor 9) - rectifier circuit 10 -T
The rectifier circuit 10 is activated by the alternating current flowing through the path of the phase connection terminal 3.
A current flows through the parallel circuit of the resistor 1, the pilot lamp 6, and the Zener diode 12. Therefore, if the pilot lamp 6 is normal, the pilot lamp 6 lights up and the pyro. When the playing card 6 does not light up, it is possible to detect an abnormality in the biloft lamp 6. Next, the case (2) of checking the continuity of each interlock contact will be explained. The following explanation assumes that the interlofter contact I4 is activated during operation of the control circuit shown in FIG. 3, and that the interlock contact I4 remains broken. Interlock contact RiI! When carrying out a check, the check bottle 4 is brought into contact with the inner side of the target interlock contact. First, when the check pin 4 is read directly to the T-in side of the interlock contacts I and T, the normal interlock contact 11 is closed, so the check pin 4 is electrically connected to the R-in side. Therefore, due to the alternating current flowing in the path of check bin 4 - contact 7a - contact 5a (or contact 5b) - resistor (or resistor 9) - rectifier circuit 10 - T phase connection terminal 3, from rectifier circuit 10 to resistor 1 pilot loft lamp. 6. Zener diode 1
Current flows through the two parallel circuits, and the pilot lamp 6 lights up. interlock contact

Even when the check bin 4 is brought into contact with the T-in sides of [2 and 2], the check bin 4 is electrically connected to the R-in side, so the biloft lamp 6 lights up in the same manner as above. Now, when the check pin 4 is brought into contact with the T-in side of the broken interlock contact I4, the check pin 4 is not electrically connected to the R-in side, so the pilot lamp 6 does not light up. As a result, it was discovered that interlock contact #4 had broken. Also, could the detected device be controlled due to a setting error in the switching switch 5? If the fll power supply is 200V, resistor 9 for 100V
Even if this is selected, the voltage applied to the pilot lamp 6 is suppressed by the Zener diode 12, and the danger of damaging the pilot lamp 6 due to excessive voltage is avoided. Incidentally, although the above example shows an example in which one circuit illustrated in FIG. 2 is housed in one housing 1, it is also possible to arrange similar circuits in parallel,
By using multiple check bins at the same time, you can find interlock locations at once. In this case, it goes without saying that the R-phase connection terminal and the T-phase connection terminal can be shared. In addition, although the example in which the R-phase connection terminal 2 and the test button 7 are provided to check the continuity of the pilot lamp 6 is shown above, even if the R-phase Vt terminal 2 and the test button 7 are omitted, the T-phase connection terminal 2 and the test button 7 are omitted. By connecting the connecting terminal 3 to the T-in of the control circuit of the detected device and connecting the check bin 4 to the R-in of the control circuit of the detected device, the pilot lamp 6 can be checked for continuity. can. However, if the R-phase connection terminal 2 and the test button 7 are provided as in the above embodiment, it is thought that operational errors will be reduced. [Effect] As explained above, according to the defect detection device of the present invention, a very simple judgment can be made as to whether or not the pilot lamp lights up by simply bringing the check bin into contact with the AND-connected interlock contacts one after another. - It is possible to reliably detect the location where the interlock contact has moved. Further, as described above, in the defect detection device of the present invention, the range is changed only by changing the resistance range in accordance with the power supply voltage of the circuit to be detected, so there is little risk of erroneous range switching. Furthermore, even if the range is changed over, if the input voltage becomes low, the brightness of the pilot lamp will only decrease, and if the input voltage becomes high, the Zener voltage will cause the pilot lamp to change to a high voltage. This will prevent the situation from being destroyed. Furthermore, according to the defect detection W i of the present invention, it is also possible to confirm whether the pilot lamp itself is good or bad.

[Brief explanation of drawings]

FIG. 1 is a plan view showing one embodiment of the present invention, FIG. 2 is a circuit diagram showing one embodiment of the present invention, and FIG. 3 is a control circuit of a device detected by the defect detection device of the present invention. FIG. 2 is a circuit diagram showing extracted portions directly related to the present invention.

Claims (2)

[Claims] (1) a first power terminal connected to one line of the control bus of the detected device; a second power terminal connected to the other line of the control bus of the detected device; and the second power terminal connected to the other line of the control bus of the detected device. a check pin connected at any time to the one line side of a plurality of interlock contacts which are connected to form an OR logic with the power terminal of the detected device, and which are AND-connected together with the operating circuit between the control bus of the detected device; a manually operated contact for selecting either the second power terminal or the check pin; and lighting when a control current flows between the second power terminal or the check pin and the first power terminal. A defect detection device comprising an indicator light and a resistance adjustment mechanism provided in a circuit extending from the manual operation contact to the first power supply terminal and changing a resistance value in the circuit. (2) In the defect detection device according to claim 1, the resistance adjustment mechanism includes a parallel circuit of a plurality of resistors corresponding to a power supply voltage of the control circuit, and one of the plurality of resistors. What is claimed is: 1. A defect detection device comprising a changeover switch for selection, wherein a power supply voltage is displayed on an operation panel of the changeover switch.