JPH04236363A - Disconnection detector - Google Patents

Abstract

PURPOSE:To provide a disconnection detector capable of detecting which of wirings generates disconnection corresponding to the opening and closing state of a contact in the wirings connecting the contact and the power supply. CONSTITUTION:In a disconnection detector 1 detecting the presence of the disconnection of cables 3-6 (wirings) connecting a contact 2 and a power supply E, the above mentioned cables 4-6 are respectively connected to both terminals of the contact 2 in sets of two to separately form respective closed circuits 7,8 and one closed circuit 9 is further formed by these closed circuits 7,8 inclusive of the contact 2 and resistors R0-R4 of predetermined values are provided to the respective cables 3-6 to judge the disconnection states of the cables 3-6 on the basis of the voltage values V2, V3 detected at the predetermined regions of the closed circuit 9.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disconnection detection device for detecting the presence or absence of a disconnection in wiring connecting a contact and a power source.

0002

2. Description of the Related Art For example, robots are equipped with attached equipment on their arms and wrists depending on their purpose. In this case, the contacts in the accessory equipment and the power supply provided on the robot body side are connected by wiring, and this wiring is supported along the arm. In the above-mentioned wiring structure, since the wiring is frequently bent or curved as the arm moves, there is a possibility that the wiring will be disconnected. Therefore, devices disclosed in, for example, Japanese Patent Laid-Open No. 59-226420 and Japanese Patent Laid-Open No. 63-26907 are known as devices for detecting the presence or absence of disconnection in wiring as described above. In the devices disclosed in the above-mentioned publications, a conductor dedicated to detecting disconnection is provided inside the insulator of the wiring in parallel with the signal conductor, and has lower durability than the signal conductor. By detecting that the signal conductor is disconnected, it is possible to predict when the signal conductor will be disconnected.

0003

[Problem to be Solved by the Invention] However, with the conventional detection device as described above, it is not possible to detect the presence or absence of an actual disconnection situation, much less the presence or absence of a disconnection in the wiring connected to the contact. . SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a disconnection detection device having a function of detecting which wire is disconnected depending on the opening/closing status of the contacts.

0004

[Means for Solving the Problems] In order to achieve the above object, the main means adopted by the present invention is to provide a disconnection detection device for detecting the presence or absence of disconnection in the wiring connecting a contact and a power source. , A plurality of the above wirings are connected as a set to both ends of the above contacts to form separate closed circuits, and these closed circuits including the above contacts form one closed circuit, and each of the above wirings is connected to each other. The disconnection detection device is configured to determine the disconnection status of each of the wirings based on the voltage value detected at a predetermined portion of the closed circuit by interposing a resistor of a predetermined value.

[0005]

[Operation] In the disconnection detection device according to the present invention, the voltage value detected at a predetermined portion of the above-mentioned closed circuit varies depending on the opening/closing status of the contact and the wiring that caused the disconnection. Therefore, by detecting the voltage value, it is possible to detect which wire is disconnected depending on the opening/closing status of the contacts.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples embodying the present invention will be described below with reference to the accompanying drawings to provide an understanding of the present invention. It should be noted that the following examples are examples of embodying the present invention, and are not intended to limit the technical scope of the present invention. Here, FIG. 1 is a circuit diagram of a disconnection detection device according to an embodiment of the present invention, FIG. 2 is an equivalent circuit diagram of the main parts in a state in which the contacts are closed in FIG. 1, and FIG. FIG. 4 is an equivalent circuit diagram of the main parts in the open state, and is a chart showing the disconnection status detected by the disconnection detection device.

In the disconnection detection device 1 according to this embodiment, as shown in FIG.
, 6 are connected as a set, and the cables 3, 4 and 5, 6 form closed circuits 7, 8, respectively. Furthermore, one closed circuit 9 is formed by the closed circuits 7 and 8 and the contact 2. In this example device,
A Zener barrier 10 is interposed in the cables 3, 4, 5, and 6 as a resistor to achieve an intrinsically safe explosion-proof structure. Further, the cables 3, 4, 5, and 6 are provided with resistors R0, R2, R4, and R3 having predetermined values, respectively. The cables 4 and 5 have comparison devices 11 and 11, respectively.
, 12 and 13, 14, a judgment logic circuit 15 is connected thereto. The above-mentioned judgment logic circuit 15 uses the above-mentioned cable 4
, 5, the voltage values V2, V detected at each predetermined portion of
3 to determine the disconnection state of the cables 3 to 6 according to the opening/closing status of the contact 2,
The comparison devices 11 to 14 compare the voltage values V2 and V3.
The function is to set upper and lower limit values that serve as judgment criteria when detecting.

In the circuit configuration as described above, when the contact 2 is closed, it can be equivalently represented as shown in FIG. In this case, V2 is (Z2/(Z1+
It is expressed as Z2))×(R2/(R1+R2))E. Also, V3 is (Z2/(Z1+Z2))×(R3/(
It is represented by R1+R3))E. In this case, Z1
is (R1+R0)(R1+R4)/(2R1+R0+R
4), Z2 is (R1+R2)(R1+R3)/(2R1
+R2+R3). On the other hand, the state in which the contact point 2 is open can be equivalently represented as shown in FIG. In this case, V2 is R2・E/(R0+2R1
+R2), and V3 is expressed as R3・E/(R4+2
R1+R3). In addition, as mentioned above, contact 2
Case 1 is the state in which the contact 2 is closed, and Case 2 is the state in which the contact 2 is open.

Under the above relationship, for example, if the cable 3 or 4 is disconnected while the contact 2 is open (Case 3), V2 becomes 0 and V3 becomes R3・E/
It is expressed as (2R1+R3+R4). Similarly, if cable 5 or 6 is disconnected while contact 2 is open (case 4), V2 is R2・E/(2R1+
R0+R2), V3 is represented by 0. In addition, if the cable 3 or 4 and the cable 5 or 6 are disconnected while the contact 2 is open (case 5), V2
, V3 are both 0.

In the above procedure, case 6 is the case where the contact 2 is closed and the cable 3 is disconnected, case 7 is the case where the contact 2 is closed and the cable 5 is disconnected, and case 7 is the case where the contact 2 is closed and the cable 4 is disconnected. Case 8 is when contact 2 is closed and cable 6 is disconnected. Case 9 is when contact 2 is closed and cables 3 and 5 are disconnected. Case 10 is when contact 2 is closed and cables 3 and 4 are disconnected. Case 11,
Case 12 is when contact 2 is closed and cables 5 and 6 are disconnected, case 13 is when contact 2 is closed and cables 4 and 5 are disconnected, and each resistance value is R0 = R3 = 1.
KΩ, R1=0.3KΩ, R2=R4=2KΩ, and a summary of these relationships is shown in FIG.

In the figure, the state at V2 is 0.
1E or less is defined as L, 0.1 to 0.38E as M, and 0.38E or more as H. In addition, in the state of V3, 0.2E or less is defined as L, and from 0.2E to 0.32E as M.
, 0.32E or more is defined as H. Therefore, as is clear from FIG. 4, in the disconnection detection device 1, based on the values of V2 and V3,
It is possible to detect which cable is disconnected depending on whether the cable is opened or closed.

0012

[Effects of the Invention] As described above, the present invention provides a disconnection detection device for detecting the presence or absence of a disconnection in the wiring connecting a contact and a power source, in which a plurality of the above-mentioned wirings are connected as a set to both ends of the above-mentioned contact. A closed circuit is formed separately for each, and a closed circuit is formed by these closed circuits including the above contacts, and a resistor of a predetermined value is inserted in each of the above wirings to detect at a predetermined part of the closed circuit. Since the disconnection detection device is characterized in that the disconnection status of each of the above-mentioned wirings is determined based on the voltage value, it is possible to detect which wiring is disconnected according to the open/close status of the contact. can.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of a disconnection detection device according to an embodiment of the present invention.

FIG. 2 is an equivalent circuit diagram of the main parts in FIG. 1 with the contacts closed.

FIG. 3 is an equivalent circuit diagram of the main parts in FIG. 1 with the contacts open.

FIG. 4 is a chart showing the state of wire breaks detected by the wire breakage detection device.

[Explanation of symbols]

1...Disconnection detection device
2... Contacts 3, 4, 5, 6... Cable
7, 8, 9... Closed circuit 11, 12, 13, 14... Comparison device 15... Judgment logic circuit R0, R1, R2, R3, R4... Resistance V2, V3
…Voltage value

Claims (1)

[Claims] [Claim 1] A disconnection detection device for detecting the presence or absence of a disconnection in a wiring connecting a contact and a power source, in which a plurality of the above-mentioned wirings are connected as a set to both ends of the above-mentioned contact to form separate closed circuits, and the above-mentioned A closed circuit is formed by these closed circuits including the contacts, and a resistor of a predetermined value is interposed in each of the wirings, and each of the above is determined based on the voltage value detected at a predetermined portion of the closed circuit. A disconnection detection device characterized by determining a disconnection status of a wiring.