This invention relates to improvements in a process and apparatus for installing a wire harness used for an automobile electric circuit into a vehicle body.
Wire harnesses used for automobile electric circuits commonly have such a structure that a large number of branch lines extend from a main line composed of a large number of electric wires bound together or bundled by a wrapping tape. Such a wire harness is installed onto a car body such that the main line thereof is wired in a spacing within an automobile and secured at several portions thereof by fastening means and the branch lines are then connected by means of connectors provided at ends of the branch lines to electrical equipment including several loads such as a motor and a solenoid, switches, and electric connection boxes such as a junction box and a fuse box.
An example of wire harness installation will be described below with reference to the drawings. Referring to FIG. 5, an instrument panel 31 molded from a synthetic resin material and a reinforcement member 32 made of a metal material are shown. The reinforcement member 32 is secured to a car body either by means of bolts or by welding, and the panel 31 is mounted on the reinforcement member 32. A wire harness 33 has a main line portion 34 and a plurality of branch lines 35 extending from the main portion 34. The branch portions 35 may be varied in length and extend irregularly in various directions from the main portion 34. Several fastening members 36 such as clips are provided on the main portion 34. The wire harness 33 is secured to the panel 31 or the reinforcement member 32 by means of the fastening members 36 or wire bands. The main portion 34 extends at an end thereof through a through-hole 38 in a car body fire wall 37 to an engine room 39 as shown in FIG. 6. A grommet 40 is fitted in the through-hole 38 of the fire wall 37 for protecting and securing the wire harness 33. Connection of the wire harness 33 to articles of electrical equipment 41 (only one is shown in FIGS. 5 and 6) may be established by means of connectors 42 provided at ends of the main portion 34 and/or the branch portions 35.
In such a wire harness of a bundle form as described above and a process of installing the same, coupling of connectors to various articles of electrical equipment is all accomplished by manual operation because the connectors are provided at ends of branch portions which extend like freely movable branches from the main portion of the wire harness, and hence hands of operators to accomplish such manual operation and spacings in which a hand can operate are required. Besides, where connectors are concentrated such as connectors 42' (FIG. 5) to be coupled to various instruments at the instrument panel, a handle column or several switches, the wire harness is larger in diameter, which makes arrangement of the wire harness and practical use of spacings further difficult. Further, in order to thread the wire harness through a through-hole of the car body, protection and fixation thereof by means of a grommet is required, and hence a hand of an operator is essentially required for installation of the wire harness. In addition, connection of the wire harness 33 with another wire harness can be done only after assembly of the panel and the reinforcement member to the car body and also requires a hand of an operator.
Thus, according to the prior art, connecting operations of a wire harness to various articles of electrical equipment depend mostly upon manual operations and it is difficult to reduce the number of man-hours for installation of the wire harness and automate such installation using a machine, which makes a serious obstruction to speed-up in automobile production lines. Besides, since manual operations are primarily involved, spacings for manual installation operations are required, which makes it difficult to entirely compact the system.