JP2658464B2 - Wiring inspection device for connection cables - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for inspecting a wiring state of a connection cable used for connection between devices when performing signal transmission between control devices, for example.

2. Description of the Related Art There is a wiring inspection device that inspects a connection cable (a cable or a harness having a connector connected to both ends thereof as a connection cable) for a wiring defect such as a short circuit, a disconnection, or an incorrect wiring.

This wiring inspection device allows a predetermined weak current to flow between each connector pin of both connectors of the connection cable to be inspected, and determines whether or not the potential difference matches the reference voltage,
The result of the determination is notified to the operator by sounding a buzzer or the like.

Problems to be Solved by the Invention In the conventional example described above, the soldering work and the crimping work for connecting each connector pin and each conductor of the cable are not appropriate, and the connection failure is caused only by the contact of the connection portion. In the case of, or in the case of a partially broken conductor wire, the current flowing for inspection is a weak current, so that the current flows as in the normal case and changes to the potential difference Does not appear. Therefore, there is a problem that it is not possible to detect a wiring failure such as a connection failure or partial disconnection.

Accordingly, it is an object of the present invention to provide a wiring inspection device capable of reliably detecting a wiring failure of a connection cable.

Means for Solving the Problems A connection cable wiring inspection device according to the present invention is a device for inspecting the wiring condition of a connection cable including a plurality of wiring paths and provided with connectors at both ends, and the inspection object and A constant current source for flowing a current through each wiring path of the connection cable, and a current value setting device for variably setting an output current value of the constant current source to a maximum allowable current value unique to each wiring path, A switch group for sequentially and selectively switching a power supply system from the constant current source to each wiring path of the connection cable, and a switch group generated when a current having a maximum allowable current value unique to each wiring path is individually supplied to each wiring path. And a comparing and judging means for comparing the potential difference with a preset reference voltage value to judge whether or not the wiring state of the connection cable is good.

The output current value of the constant current source is set to the maximum allowable current value of each wiring path of the connection cable to be inspected by the current value setting device, and the output current of the constant current source is individually set for each of the wiring paths. And each potential difference generated at both ends of each wiring path is detected. Then, for example, each potential difference is compared with each potential difference to be generated in a normal state, and if the difference is within a predetermined range, it is determined that the wiring state is good. If the difference is outside the predetermined range, the wiring state is bad. Is determined.

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

In the figure, reference numeral 1 denotes a connection cable to be inspected. The connection cable 1 includes a cable body CA including four conductors CAa to CAd, a connector CN1 having one connector pin connected to one end of each conductor CAa to CAd, and a connector CN connected to the other end of each conductor CAa to CAd. It consists of a connector CN2 to which pins are connected. 2 is a constant current source, 3 is a current value setting device for variably setting the output current value of the constant current source 2 to a predetermined current value, 4 and 5 are connectors respectively connected to the connectors CN1 and CN2,
W1 to SW4 connect the conductors CAa to the constant current source 2 by connecting the connectors CN1 and CN2 to the connectors 4 and 5, respectively.
To CAd are shown. SW5 to SW8 are connectors CN1 and CN2 are connectors 4,5.
Are connected to the conductors CAa to CAd in parallel with respect to the constant current source 2 by being connected to
Are connectors 4,5 provided via switch groups SW5 to SW8.
The potential difference between the reference voltage generator 7 and the voltage supplied from the reference voltage generator 7 is compared, and if the difference is within a predetermined value, a comparator as comparison determination means for turning on the output, 8a to 8d are switch groups SW9 to SW
Registers respectively connected to the output terminal of the comparator 6 via W12 and temporarily storing the output state of the comparator 6, and 9 indicates whether the wiring state of the connection cable 1 is good or bad according to the contents stored in the registers 8a to 8d. The judgment output circuit for judging and outputting the judgment result is shown. And 10 is the switch SW1, SW
5, one group of SW9, one group of switches SW2, SW6, and SW10, one group of switches SW3, SW7, and SW11;
This is a switch switching device in which SW8 and SW12 are grouped into one group and switches in each group are simultaneously turned on / off.

In this embodiment, the wiring state of the connection cable 1 is inspected by the following operation procedure.

First, when all the switches SW1 to SW12 are off, connect the connectors to the connectors CN1 and SN2 of the connection cable 1 to be inspected.
Connect 4,5 respectively. Next, by operating the current value setting unit 3, the output current value of the constant current source 2 is set to the maximum allowable current value of each of the conductors CAa to CAd corresponding to the maximum allowable current value of each wiring path of the connection cable 1. The voltage generated by the reference voltage generator 7 is set to the potential difference between the connectors 4 and 5 that occurs when the current having the maximum allowable current value normally flows through the conductors CAa to CAd. This setting operation need only be performed once before the next energizing operation when the maximum allowable current value of each wiring path is the same, but must be performed for each energizing operation when they differ from each other. By operating the switch switching device 10, the switch
SW1, SW5, and SW9 are turned on, and power is supplied to the wiring path including the conductor CAa. By this operation, the potential difference generated between the connectors 4 and 5 is compared with the voltage generated by the reference voltage generator 7 in the comparator 6, and the output state of the comparator 6 is stored in the register 8a. Thereafter, by operating the switch switching device 10, the switches SW1,
SW5, SW9 are turned off, switches SW2, SW6, SW10 are turned on, then switches SW2, SW6, SW10 are turned off, switches SW3, SW7, SW11 are turned on, and switches SW3, SW7, SW11 are turned off, switch SW4,
The switches SW8 and SW12 are turned on to sequentially energize the respective wiring paths of the connection cable 1.

By the above operation, the respective output states of the comparator 6 when the respective wiring paths of the connection cable 1 are energized are changed to the respective registers 8a to 8d.
Respectively. Then, the judgment output circuit 9 reads the stored contents of the registers 8a to 8d, judges whether there is a wiring path with a bad wiring state based on the contents, and outputs the judgment result. If there is a bad wiring route,
Based on the determination output, for example, an LED or the like specifies which wiring path is defective and displays it.

As described above, in this embodiment, the quality of each wiring path is determined by flowing the maximum allowable current value of the conductors CAa to CAd through each wiring path of the connection cable 1, so that short-circuit, disconnection,
In addition to detecting wiring faults such as erroneous wiring, connector pins CN1 and CN2 and conductors CAa to CAd
Is in poor contact, or conductors CAa to CAd
In the case of a partial disconnection in which some of the element wires are disconnected, the voltage drop due to the increase in the resistance value caused by the defective wiring is large due to the large current value, and the defective wiring can be detected.

Effect of the Invention As described above, according to the present invention, a current having the maximum allowable current value flows through each wiring path of the connection cable to be detected,
Since the quality of the wiring of the connection cable is determined, it is possible to reliably detect a wiring failure such as a connection failure or a partial disconnection that cannot be detected only by passing a weak current.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a configuration of one embodiment of the present invention. DESCRIPTION OF SYMBOLS 1 ... Connection cable, 2 ... Constant current source, 3 ... Current value setting device, 6 ... Comparator (comparison determination means), 7 ... Reference voltage generator, 8a-8d ... Register, 9 ... Judgment output circuit.

Claims (1)

(57) [Claims] An apparatus for inspecting the wiring condition of a connection cable including a plurality of wiring paths and having connectors at both ends, the apparatus including a plurality of wiring paths, and a constant for flowing a current through each wiring path of the connection cable to be inspected. A current source; a current value setting device for variably setting an output current value of the constant current source to a maximum allowable current value unique to each of the wiring paths; and a power supply from the constant current source to each of the wiring paths of a connection cable. A switch group for sequentially and selectively switching the system, and comparing a potential difference generated when a current having a maximum allowable current value unique to each of the wiring paths is individually supplied to each of the wiring paths with a preset reference voltage value. And a comparing and judging means for judging the wiring condition of the connection cable.