METHOD FOR FORMING WIRE HARNESS AND APPARATUS FOR THE SAME

Abstract: Method of forming wire harness into flattened structure with desired pattern for use in motor vehicle is disclosed. A group of insulated wire is drawn out of wire source by means of a wiring head having a wavering wire guide and a roller with heating means and the wires are placed on a forming boad with a travelling means in an parallel alignment to each other. The wire leading direction on the forming table is controlled by a computer program and any desired harness pattern is formed by moving the wiring head in the longitudinal direction of the wires, X axis, and travelling the forming table in the direction of Y axis which is perpenduclular to the axis X. The neighbouring wire in the parallel alignment on the table are bonded together either by fusing their surface of insulating material or by ulitizing suitable adhesive or softening agent while suitable stretching tension is applied to the wires. In the embodiments of the present invention an apparatus for achieving the same purpose is also disclosed.

Description: This invention relates to an improved method of forming wire harness for use in an automobile, particularly, in a wiring harness assembly placed within a limited space such as a door structure, or ceiling space in a room cabinet. As a preferred embodiment of the present invention, an apparatus for manufacturing the wiring harness assembly is disclosed, in which insulated wires are placed in a parallel alignment followed by bonding the neigbouring wires so that the wiring harness exhibits a predetermined, desired flattened shape. The wiring harness for motor vehicles is composed of a variety of elements. Those include groups of insulated electric wires, connectors consisting of electrical terminals and plastic housing of connectors, grommet and outer binding materials such as clamps and tapes. In general a design table with guide-pins is used to manufacture a set of wire harness assembly, in which an approximate length of insulated electric wire with an electrical terminal in its one end portion is wired along a drawing on the table in which the guide-pins stand aside the trail of wire, and desired numbers of wires are set to form a harness configuration. The sets of wires are then bundled together by means of binding materials resulting in a group of an assembled but shapeless wire collection. The above manual method of making an assembled wire therefore requires a lot of man-hours, and wires are likely to be used in excess due to their suspension between neighbouring guide-pins caused by uneven stretching. In addition, the produced wire harness assembly becomes bulky, which causes difficulty when it is entended to be used for wiring in a limited space such as in a door structure. The US-A-3,699,630 reports on apparatus for use in the manufacture of a wire harness as well as a method for forming this wire harness. A wire dispensing head is controlled to selectively dispense wires from a group of supply spools, laying the wire along predetermined paths according to the desired harness pattern configuration, cutting the wires to conform to the individual path lengths, and securing the wires at respective termination sites. The thus spent wires are cramped together by cramps to form a harness which usually has an almost cylindrical cross section. The US-A-4,071,393 discloses an apparatus for use in the manufacture of a wiring harness of the kind including a plurality of electrically insulated wires having their thermoplastic sheaths fused to a thermoplastic backing tape. Accordingly, the electric insulated wires are directed in a parallel configuration between two cylinders and are covered on the upper and lower side with endless sheaths or strips which are capable to bond to each other. The cylinders press the tape against the wires and at least one of the cylinders is driven so that the wires and the tape are driven between the cylinders as a result of rotation of the cylinder. A hot air blower blows hot air onto the tape and the sheets of the wires immediately before they pass between the cylinders so that when pressure is applied to them by the cylinders the heated surfaces fuse together. However, none of the above mentioned apparatus and methods for producing wiring harness are providing wiring harness which are capable to be used in technical fields where only a limited space is available, since on the one hand the resulting cylindrical cross section is inadequate, or, on the other hand, further bonding material is applied which further increases the amount of material to be stored in e. g. a door structure. It is therefore the object of the present invention to solve the above inefficiency in assembling operation and to reduce bulkiness of the products. This object is solved by an apparatus in accordance with claim 1 and by a method for forming a wire harness assembly in accordance with claim 6. Accordingly, an apparatus for use in the manufacture of the wire harness is disclosed comprising a wire guide having a wavering element in a wiring head attached to a transversal axis X along longitudinal directions of wires. Further, a wire forming table with a flat surface on the top is provided having a travelling mechanism along the Y-direction, which is perpendicular to the transversal X-axis. Additionally, wire bonding means are provided comprising a wire press mechanism either by thermal fusion or by adhesion while a group of insulated electric wires are led by said wire guide on the forming table in a closed, parallel alignment. The method for forming wire harness comprises the steps of selecting a group of insulated electric wires to be connected to the terminals showing a common connector housing, clamping the starting end portion of each of the selected wires in order, drawing wires out of supplying means and placing the measured and cut wires in a parallel alignment using a wafering wire guide on a forming-table which is able to travel along rails laid in a direction Y perpendicular to the longitudinal axis X, pressing them with a roller or roll mechanism having heating means while disentangling and bonding the neighbouring wires simultaneous either utilizing an adhesive or suitable softing agent or by thermal fusion of the surfaces of insulation of wires, and leading wires through the wafering wire guide while the wire guide moves an X-direction and the forming table shifts in Y-direction achieving two-dimensionally plotted desired harness pattern on the table. Summarising, the method of forming wire harness of the present invention comprises the steps of selecting a group of the insulated electric wires to be assembled, clamping the starting ends of the wires in order, followed by applying a metallic terminal to each wire end if desired, placing measured and cut wires on a forming table with a program controlled travelling means along the Y axis which is perpendicular to the longitudinal direction of wires X, making a parallel alignment of wires by providing them with a wiring head which consists of a wavering guide and a press mechanism with or without grooves for disentangling wires while the wiring head traces back along axis X, bonding the neighbouring wires as the wiring head proceeds by either thermal fusion of the outer surface of the insulating layer of the wire or utilizing suitable adhesives on the surface of the wire, controlling both the movement of the wiring head along the coordinate X and that of the forming table along the coordinate Y, shaping the wires into any desired flattened harness pattern which is particularly useful for wiring door harness of motor vehicles. An apparatus for achieving the same object is described in the preferred embodiment of the present invention, in which the insulation layers and the untreated, opposite wire ends are removed in order to apply electric terminals and connector housing. Fig. 1 shows steps of forming wire harness of the present invention. Fig 1(A) is a process diagram illustrating the method of the present invention. Fig 1(B) shows a side view illustrating the wire feed. Fig. 1(C) shows a harness pattern formed on the forming table. Fig. 2 shows the apparatus for forming wire harness of the present invention. Fig. 2(A) illustrates a front view of the apparatus of the present invention. Fig. 2(B) illustrates a side view of the wavering wiring head on the forming table with an index roller having grooves being used in the apparatus of the present invention. Fig. 2(C) is an enlarged front view illustrating the wiring head used in the apparatus of the present invention. Fig. 2(D) is an enlarged view illustrating an index roller The preferred embodiments of the present invention are hereinafter described in detail. Referring to Fig. 1, a process layout for forming a wire harness for use in a automobile door harness is explained. It is composed of a wire-forming table (2) having a travelling mechanism along the Y axis which is perpendicular to a longitudinal direction X of a group of insulated electric wires to be assembled, and of a wiring head (3) having a wavering mechanism and a press means with or without grooves for wires equipped with heating means. The wiring head (3) suspends over the wire-forming table (2) and is movable along the axis X, and thus the table (2) and the wiring head (3) constitute a X-Y plotting element. In front of the wire-forming table (2) are located a wire supply (4), a clamp (5) which is able to turn toward a terminal crimp machine (7), and a cutting machine (6). At the back of the wire-forming table (2) are positioned wire-carrier (8) having a clamp mechanism for holding the starting ends of wires A, insulation remover (9), terminal crimper 7 and applicator for connector housing (11), both applicable to the terminating ends B, and terminal supplier (12). The steps employed in the method of forming wire harness assembly of the present invention are described as follows. A group of wires (1) is selected for a set of wiring harness to be assembled. The selection is usually made among the wires which share a common connector within total harness structure. The wires are drawn out of a wire supply (4) and are held properly by a wire clamp means (5) which is able to turn into a direction perpendicular to the longitudinal direction X of the wires where a terminal crimp element including a wire-insulation remover and a terminal crimper (7) with a terminal feeder (12) are located. After the wires are placed on the forming-table (2) in a U-shaped pattern, while holding each of the wires in a flat, parallel alignment, the destined wire ends (B), which are on the opposite side of the staring wire ends (A), is shifted toward Y2 and Y3 direction along axis Y. The wire ends (B) are subject to extra steps including insulation removal at (9), terminal crimping at (7), and a connector housing is attached at (11), and thus flat wire harness is obtained. If necessary, the starting ends A of the wires are crimped with terminals, and then lead along the X axis while the A ends are held by the clamp (5) until it reaches a cutter (6). A wire carrier (8) proceeds to the cutter (6) and holds the wire end A, and the clamp (5) moves back to the original position along axis X while wires are brought to a table end portion (13) where the wire ends A are fixed. Each of the wires is measured by means of dancer-roller passway (14) in length according to their anticipated distance in an assembled harness on the table (2) and is cut by the cutter (6). Fig. 1 (C) illustrates a harness pattern formed by the method of the present invention. A wiring head (3) having a wavering mechanism and a press means suspends over the wires on the table (2). At the table end portion (13) the wiring head (3) comes down to the table (2) and touches the wire-surfaces in its press means such as a guiding roll (20) with or without grooves for wires. As the wiring head (3) proceeds in the direction of X, the wires (1) are disentangled and simultaneously the neighbouring wires are bonded together by either thermal fusion in the surfaces of their insulation or by using an adhesive. The corner portions R1 and R2 are formed by moving the wiring head (3) and the forming-table (2) into X and Y directions, respectively, according to a programmed design for an anticipated harness pattern. Preferred embodiment of the present invention of forming wire harness is that a both-sided adhesive tape having larger width than that of the actual harness pattern to be traced is placed on the wire-forming table (2) along the passage or wires before the wires are lead on the table (2) through wire-guide (3). The tape sticks to the wire surfaces and is useful as a substrate for maintaing the wires (1) on the predetermined position in a parallel alignment until the neighbouring wires become bonded. The tape can be removed after the harness has been formed in a pattern. It should be emphasized that a flat harness with integrating unit pattern can be formed, in which a number of branches are included in a single pattern. In other words, a complexed flat harness is provided by integration of unit harness elements which consist of a group of wires as described in the present invention. An apparatus for achieving the same object of forming a flat harness with parallel wire alignments is described referring to Fig. 2. The Figure illustrates a front view of the device. To the wire-forming table (2) are equipped two guide rails (17A) and (17B) along which the wire-forming table (2) can be slidably moved in a direction of the Y axis. 16A is a rotatable driving rod located in the middle and underneath the table (2). 16B is also a rotatable driving rod to which the hanger (18) of wiring head (3) is attached. The rod is literally the X coordinate and is parallel to the longitudinal wire direction. In the example illustrated in Fig. 2, the wavering wiring head (3) and three rollers (20), (21A) and (21B) are attached to the head portion of the hanger (18). The roller (20) is an indexing roller whose course is directed by a computer program, and the other two are rollers for disentangling the wires (1) into a parallel alignment between each other. The latter rollers (21A) and (21B) have spaced grooves for wires and are equipped with heating means which are useful for bonding neighbouring wires by thermal fusion. The latter two rollers follow the trail of the former roller (20). The wires (1) are introduced into a hollow pipe (23) and are drawn to the forming-table (2) and are disentangled and bonded together as the three rollers (20), (21A) and (21B) pass over them. When index roller (20) has completed its programmed tracing around an desired harness pattern, the wires (1) on the forming table (2) are aligned in parallel showing formed flat pattern of wire harness. As described above, the wires (1) are lead into their common longitudinal direction X by moving the wiring head (3) which is driven by rotating the driving rod (16B) and also wires (1) are directed toward the Y direction by travelling of the forming table (2). By combing these movements along the axes X and Y, any desired pattern with or without curvature can be plotted. According to the apparatus for forming wire harness, a flat, two dimensionally plotted wire harness is provided. When the wires are pressedly bonded while maintaining their parallel alignment, an accurate harness pattern is achieved.

Claims: Apparatus for use in the manufacture of a wire harness with flattened structure comprising: a wire guide (20) having a wavering element in a wiring head (3) attached to a longitudinal axis X along longitudinal directions of wires, a wire forming table (2) with flat surface on the top having a travelling mechanism (16A, 17A, 17B) along Y direction which is perpendicular to the longitudinal axis X, characterized by wire bonding means (21A, 21B) with a wire press mechanism either by thermal fusion or by adhesion while a group of insulated electric wires (1) are led by said wire guide (20) on the forming table in a close, parallel alignment. Apparatus of Claim 1 wherein the wavering element in the wiring head (3) includes a leading guide means (20) which traces a programmed wire pass and a wire pulling means which follows the leading guide means (20). Apparatus of Claim 1 and 2 wherein the wiring head (3) includes a thermal press roller (21A, 21B) for bonding electric insulation wires so that the wires in the parallel alignment become bonded together resulting in a desired, flattened structure as a whole harness. Apparatus of Claim 1, 2, and 3 wherein wire-connecting terminals are applied to the starting end portion (A) of the electric insulated wires before bonding. Apparatus of Claim 1 wherin an address of the wavering element in the wiring head on the forming table is indicated on the X-Y coordinates by an automatic control means having a location program according to the pattern of wiring harness to be formed. Method for forming wire harness comprising the steps of: selecting a group of insulated electric wires (1) to be connected to the terminals sharing a common connector housing; clamping the starting end portion (A) of each of the selected wires (1) in order; drawing wires (1) out of supply means (4) and placing the measured and cut wires (1) in a parallel alignment using a wavering wire guide (20) on a forming-table (2) which is able to travel along rails (17A, 17B) laid in a direction Y perpendicular to the longitudinal axis X; characterized by pressing them with a roller or roll mechanism (21A, 21B) having heating means while disentangling and bonding the neighbouring wires simultaneous either utilizing an adhesive or suitable softing agent or by thermal fusion of the surfaces of insulation of wires (1); and leading wires (1) through the wavering wire guide (20) while the wire guide moves in X direction and the forming table (2) shifts in Y direction achieving two-dimensionally plotted desired harness pattern on the table. Method of Claim 6 wherein wires (1) are placed on a both-sided adhesive member whose opposite side is pasted to the table surface and the adhesive member is removed from harness after wires (1) are formed. Method of Claim 6 and 7 wherein the wires (1) are placed in a parallel alignment on the forming-table (2) using two types of roller means (20, 21A, 21B) consisting of an indexing roller (20) for guiding wires (1) to a position with a pre-determined, programmed address along the two dimensional way, and of rollers (21A, 21B) for entangling wires and for bonding the neighbouring wires (1) by thermal fusion of wire insulation surface or by utilizing adhesive or softing agent.

Inventors: FUKUDA, MICHIO SUMITOMO WIRING SYSTEMS LTD., IIDA, TSUTOMU SUMITOMO WIRING SYSTEMS LTD., ITAYA, NOBUYUKI SUMITOMO WIRING SYSTEMS LTD., KURODA, NAOKI SUMITOMO WIRING SYSTEMS LTD.
Applicants: SUMITOMO WIRING SYSTEMS, LTD.
Application year: 1987
Main classification: H02B1
IPC codes: H01B13, H01R43