Fault locator apparatus for wire harnesses

• US 6,011,399 A
• Filed: 12/30/1996
• Issued: 01/04/2000
• Est. Priority Date: 01/10/1996
• Status: Expired due to Fees

• Current Assignee: Harness System Technologies Research, Ltd. (Sumitomo Corporation), Sumitomo Electric Industries Limited (Sumitomo Corporation), Sumitomo Wiring Systems Limited (Sumitomo Corporation)
• Original Assignee: Harness System Technologies Research, Ltd. (Sumitomo Corporation), Sumitomo Electric Industries Limited (Sumitomo Corporation), Sumitomo Wiring Systems Limited (Sumitomo Corporation)
• Inventors: Miyazaki, Yoshiyuki, Matsumaru, Akio, Kido, Motonori
• Primary Examiner(s): Ballato, Josie
• Assistant Examiner(s): SOLIS, JOSE M
• Application Number:
  US08/774,610
• Time in Patent Office: 1,100 Days
• Field of Search: 324/522, 324/538, 324/52, 324/539, 324/503, 439/497, 356/73.1, 317/18
• US Class Current: 324/538
• CPC Class Codes: G01R 31/11 using pulse reflection methods
• CPC Class Codes: G01R 31/50 Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections testing of sparking plugs H01T13/58
• CPC Class Codes: G01R 31/58 Testing of lines, cables or conductors testing of electric windings G01R31/72

Abstract

An apparatus for detecting a trouble location in a wire harness can easily detect a location of any trouble such as breakage or short circuit in electric wires in a wire harness and in particular can detect the trouble location by way of a simple structure utilizing a portion with a shield function. In the detecting apparatus, a pulse signal is transmitted in electric wires (2) in a wire harness (1), in which a trouble location is to be detected, and in a sensing line juxtaposed along the electric wires (2) at their ends. A measuring device (20) receives a reflected wave from a transmitted wave and measures a difference in time between the transmitted wave and the reflected wave. A distance from a transmitting end point to a trouble location point is determined in accordance with the difference in time and a signal propagation velocity. Each electric wire (2) in the wire harness (1) is a single wire having no splice portion and a shielded wire having a conductive shield sheath (10). The wire harness (1) is provided with a connection part for connecting each electric wire (2) and the shield sheath (10) to the measuring device (20).

Claims

1. An apparatus for detecting a trouble location in a wire harness, comprising:

a wire harness having a plurality of electric wires, in which a trouble location is to be detected, each of said electric wires being a single insulation-sheathed wire, said wire harness including a main line part and at least one branch line part, each of which is protected by a sheath member, at least one of said electric wires in said main line part extending into said branch line part without any splice;

a plurality of sensing lines juxtaposed along said electric wires; and

a measuring device which transmits a pulse signal in said electric wires and said sensing lines at their ends and receives a reflected wave from a transmitted wave, said pulse signal having a pulse width (A) of 0.049-0.976 n sec, a period (B) of 48.78 n sec, and a duty ratio (A/B) of 0.001-0.020, thereby measuring a difference in time between the transmitted wave and the reflected wave;

each of said electric wires in said wire harness being covered with a conductive shield sheath, said wire harness having a connection part for connecting each of said electric wires and each shield sheath to said measuring device, thereby using said shield sheath as a sensing line upon detecting said trouble location;

whereby a distance from a transmitting end point to a trouble location point is determined in accordance with said difference in time and a signal propagation velocity;

said main line part having a main connector connected to said connection part and said branch line part having a branch connector at a distal end thereof, whereby said trouble location can be detected while said wire harness is installed in a vehicle.

2. The apparatus of claim 1 wherein said sheath member is a tape which includes a conductive layer between insulation layers, and an adhesive layer on either surface of said insulation layers.

3. The apparatus of claim 1 wherein said sheath member is a tube having a conductive layer between insulation layers.

4. The apparatus of claim 1 wherein said sheath member is a tape which includes a conductive layer between insulation layers, and an adhesive layer on either surface of said insulation layers.

5. The apparatus of claim 1 wherein said sheath member is a tube having a conductive layer between insulation layers.

6. The apparatus of claim 1 wherein said branch connector contains a terminal connected to said conductive shield sheaths on said electric wires.

7. The apparatus of claim 1 wherein said connection part provided on said wire harness includes a connector for partial electrical wiring and a detecting connector separately.

8. The apparatus of claim 1 wherein said connection part provided on said wire harness includes a connector for partial electrical wiring and a detecting connector which are formed together with each other.