A typical technological process for the manufacture of a tow. Production of electrical harnesses. Development of the technological process for the manufacture of bundles. Classes of machines for making tow. Materials and components for the manufacture of harnesses
Plan:
1. Appointment
2. Technology of making harnesses
3. Marking
4. Safety
Purpose
In the manufacture of electronic devices, a significant proportion of the work falls on the switching of devices inside these devices.
Harnesses- wires running in one stream in parallel along one route, tied or fastened together, terminated connections to circuit elements.
tourniquet
For devices of the same type, to speed up the installation process, wire harnesses are made separately.
The bundle combines direct and reverse conductors with industrial frequency currents according to its scheme.
The wires used in high-frequency equipment are not tied into bundles (since this increases the capacitance between the conductors).
The harnesses are made with a sheath for their fastening and shielding, as well as without sheaths. The wires of the bundles are fastened with a continuous bandage of cotton threads. For installations operating at high temperatures - with glass threads, followed by impregnation of the bandage with wax or paraffin, sometimes with varnish or glue.
Shells are tubular, tape, strip and wicker. Tubular shells are soft and hard.
For soft ones, PVC tubes are used, for hard ones - Al, which, in addition to protection against mechanical damage, perform the function of electrical shielding.
The braided sheath is made of Cu or Al braid, which is easy to put on, provides good bonding, flexibility and shielding. During installation, a metal braid is attached to the body.
1 - electrical tape or shell; 2 - tourniquet; 3 - branch
Tape casings are made of synthetic tape or nylon fabric with a nitrocellulose coating. This shell is practical in that any damaged area can be replaced.
Strip shells- a cover sewn along the tourniquet.
2. Technology of making harnesses.
1) Preparation by type. Coloring and cross-section of wires;
2) cut them;
3) laying them in the required combination according to the template;
4) fastening their visible or dressing shell;
5) dialing and marking;
6) termination and external control.
Making harnesses
Laying is done on templates. Sample- a wooden panel on which the configuration of the harness is applied in full size. The ends of the bundle are fixed with end and rotary clamps. The direction of the laying of each conductor is indicated by a line marked with paint according to the template, with a small number of conductors. With a large number of conductors, the laying is carried out according to the drawing or according to the table of conductors included in the wiring diagram.
On the template, the tourniquet, consisting of individual conductors, is tied with a bandage. The ends of the conductors are terminated.
Marking.
It facilitates the installation and operation of electrical installations, it is applied to everything: devices, devices, clamps, wires, panels, shields, cabinets, consoles and cables.
Marking on the equipment is applied with a stencil or stamp. On the cable - on hanging tags or terminations; on cores - on terminals, PVC tubes or marking adhesive tape.
Secondary circuit wires use colored wires or wires with letter or number markings along the entire length of the insulation.
Different colors are used to indicate phase and polarity: A-yellow, B-green, C-red, blue -"─", red -" + ”.
For marking wires, black carbolite marking end caps or PVC end caps are also used. Marking on carbolite is applied with whitewash, on PVC or capron - ink marking. During installation, the wires are marked with temporary hanging tags made of cardboard, the inscription is written in pencil. After connecting the wires to the terminals, permanent tags are put on the ends of the wires, on which inscriptions are transferred from temporary ones.
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Hinged plastic or metal tags are used for marking cables and bundles. Tags are fixed on cables and bundles with plastic or metal viscous. The inscriptions are applied manually, with a stencil or an embossed stamp.
For the manufacture of harnesses, mounting copper wires with various types of insulation are used: fibrous from nylon threads (MShDL, MESHDL, MGSH, MGSHD) or fiberglass GShchGSL, MGSLE); polyvinyl chloride (PMV, MGV) and fibrous-polyvinyl chloride (MShV, MGSHV, BPVL). At elevated temperatures (up to 250 ° C) and humidity, wires with fluoroplastic insulation (MGTF) are used, for equipment operating at -70 ° C, wires in a hose sheath made of frost-resistant rubber grades RPD and RPSHE. High-frequency signal circuits for protection against electromagnetic interference are switched by shielded wires and cables with the obligatory grounding of each shield at one (with a length of up to 100 mm) or two points (with a length of more than 100 mm). The following requirements are imposed on wires for bundled installation: compliance of the cross section of the conductive core and insulation with the working current density and the permissible voltage drop; mechanical strength, flexibility and elasticity; no damage (undercuts, arson) that reduces their mechanical and electrical strength; the use of markings; the presence of a margin in length, providing repeated soldering.
For each harness, a drawing is developed by the prototyping method, according to which a flat or three-dimensional template is made, and a table of connections is compiled. On the template, the wire laying routes are limited to studs or pins. Pins are also installed in places of bends and branches, at the start and end points of the routes.
T 
The technological process of bundled wiring consists of the following steps: cutting the installation wires and cables, assembling and knitting the bundle on a template,
connections with contact elements, tracing and fixing on the supporting structure, quality control of execution. The bulk of the work in the manufacture of bundles is occupied by preparatory operations: cutting incoming wires and cables into measured sections, cutting the ends and fixing the insulation, removing the oxide film, twisting, tinning and marking. Cutting and stripping of insulation from the ends of single wires is carried out by the methods described in § 4.3, using universal machines, devices or manually. Automatic equipment (Fig. 4.8) is designed for cutting mounting wires of various sections with a length of 50 ... 1350 mm with simultaneous firing of insulation at the ends at a distance of 5 ... 10 mm at a speed of 2000 pieces / h. To strip the ends of high-frequency cables, mechanized equipment is used, in which insulating and shielding layers are sequentially removed. The separation of the outer PVC coating is carried out by an incision with a rotating knife or
thermomechanical treatment of the surface to be removed using two overlay plates with sharp knife edges, made according to the diameter of the conductive core. The braided shield is removed in a helical shear block. The block (Fig. 4.9) consists of a sleeve 1, two knives 2 and cutters 3 rigidly connected to them. By moving the sleeve along the axis away from the limit stop 5, the processing length is set. When the cutters rotate towards the movement of the cable 4, the shielded braid is bent and cut off, falling into the gap between the teeth of the cutters and knives. A circular cut of the shielding braid is provided by the radial rotation of the block. The remaining layers of cotton, polyethylene and rubber insulation are removed mechanically (by notching) or thermomechanically.
To extract the insulated wire from the shielding braid, a dielectric needle with a hook is used, which expands the strands of the braid with a sharp end and pulls the wire through the hole formed. The part of the braid freed from the wire is soldered to the body lobe directly or through a piece of the mounting wire.
After removing the insulation, the bare ends of the stranded wires are twisted in a rotating drill chuck, in which a bushing with a conical hole is fixed, and all prepared wires are sent for fluxing and tinning with POS-61 molten solder. To protect the fibrous insulation from loosening, its ends are fixed with nitro-glue, stamped plastic tips, by dressing segments of linoxin or polyvinyl chloride tubes, by bandaging with threads. Cutting dielectric tubes into sections of the required length is carried out on an automatic machine, the diagram of which is shown in fig. 12.10. It allows you to cut tubes with a diameter of 2...5 mm and a length of 8...20 mm. The productivity of the machine is 300 thousand blanks per shift.
Reducing the complexity of installation and assembly work, reducing the number of incorrectly made connections, facilitating the control of finding faults and repairs is achieved by marking wires. It is carried out by changing the color of insulated mounting wires, adhesive tapes with numerical or alphabetic codes, marking tubular tags, or by applying markings directly to the wire insulation. The last two methods are most widely used due to their high performance and reliability of execution. Marking tags
receive on a machine similar to that shown in Fig. 4.10, additionally equipped with a replaceable heated marking punch, which, during its movement, presses the paint from the rewound roll of colored tape into the surface of the dielectric tube. Change of a punch and a tape occurs within 1 min. Equipment for marking wire insulation is built on the same principle, but the operation is performed before cutting the wires into sections (machine from Artos, USA). The marking tags are put on the wire in such a way that the cutoffs of the insulation are covered by 1 .. "... 3 mm and their displacement during operation is excluded.
Assembly of harnesses in accordance with the drawing and the table of mounting connections is carried out manually, using an electrified template or on CNC machines. Electrified templates, which are economical in manufacturing, are widely used, since this reduces the labor intensity of the work and reduces the amount of possible marriage. On such templates, the end pins are replaced with quick-clamping buttons, into which LEDs or signal lights (green) are mounted, and red control lights are installed on the connection table next to each route and on the cassette near the cassette with the corresponding prepared wire. Light bulbs and clips are switched in such a way that when the template is connected to the network, a pair of green lights light up, indicating the installation location, and a pair of red lights that determine the type of wire and its location in the cassette. After the correct laying and fixing of the wire, the signal lights of the first route go out, the lights of the second route light up, etc. The control of the correct laying of the wires is carried out from the control panel by the glow of all the lights located at the connection table.
In mass production, CNC automatic equipment is used (for example, a machine tool from Eiectromat, GDR). It is designed for the manufacture of bundles on templates 550X1250 mm in size with 20 wires of different colors with an insulation diameter of 0.5 ... 1.5 mm, including three pairs of twisted wires 2X1 mm in size. The machine consists of a laying head, a drum on which the template is attached, two drum movement mechanisms, consisting of a stepper motor, a worm gear and a magnetic brake, as well as a control system powered by punched tape. The turning points and working steps of the machine are determined by the coordinates on the harness drawing. To check the compiled program and place the end and tracing pins on the template, instead of the laying head, a recorder is fixed, which reproduces the pattern of the bundle. Holes are drilled in the places marked in the figure and pins are inserted for attaching wires.
Before starting the machine, coils with wires are installed on brackets, and the ends of the wires are inserted into the magazine located on the laying head, in the sequence determined by the program. By moving the magazine, the wire is fed into the laying head, which leads it into the template hole next to the initial pin and secures it by winding it onto this pin. The laying of wires along the route is carried out at any angle due to the rotational and transverse movement of the drum with the template. On the final pin, a piece of wire occurs and the operation of its fastening is repeated. To eliminate damage to the wire, the laying head straightens it, and after laying several wires in one plane, it rises higher. If several wires end on one pin, then the machine cuts them to different lengths and winds them at different heights.
The template with the assembled harness is removed from the drum and replaced with a new one, and the removed one is sent for knitting. The time it takes to change the machine to another type of harness depends on its size and complexity. The change of templates is carried out in 30 s. Average spreading speed 10 m/min. Since the harness is assembled on the machine from unprepared wires, these operations are performed after knitting, but using manual devices.
The wires laid in the bundle, without removing from the template, are tied with threads, tape 10 ... 50 mm wide, shrink film, leather or pressed with rubber. The knitting step is determined by the cross-section of the mounting wires, the number of wires in the bundle n and its diameter D. On curved sections, the knitting step is reduced by 1.5-2 times. Knitting with threads is carried out manually or with the help of pneumatic devices.
From the above description of the TP, it can be seen that in the conditions of serial production, two options for the route for the manufacture of bundles are possible: 1) automatic preparation of wires for installation and manual assembly on a template; 2) automatic layout of wires and their manual preparation for installation.
The choice of the optimal structure is determined from the real conditions for a minimum of labor costs.
Next, the manufactured harness is sent to check the correctness of installation and the quality of the preparatory operations. The assembly of the bundle with connectors, switches and other contact elements, as well as the laying of constructs on the frame and fastening is carried out in the same way with the PLC.
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1. Technical characteristics of the production facility
The technical characteristic of the production facility for which this technological process is being developed is the manufacture of bundles.
General information about harnesses and their manufacturing technology
Bundled installation is electrical installation EVA knots with the help of volumetric insulated wires united in a bundle.
The harness designs are determined by the structural features of the frames and the requirements for the maintenance and repair of equipment. Harnesses are divided into interblock and intrablock, which, in turn, are divided into flat, volumetric, with movable branches.
They are also distinguished by the degree of complexity: the number of branches and closed branches. Harness installation is carried out using mounting wires and cables various types and appointments. Wire insulation can be fibrous from kapron threads (MShDL, MGSH, MGSHD) or fiberglass (MGSL, MGSLE); polyvinyl chloride (PMV, MGV) and fibrous polyvinylchloride (MShV, MGSHV, LPBL), plastic in the form of a shell of polyvinyl chloride (MKSH, MPKSH); rubber (LPRGS, PRP, APRF, PRG) and fluoroplastic (MGTF). The choice of insulation is determined by the electrical voltage and operating conditions of the equipment.
At normal temperature and humidity, wires with fibrous or PVC insulation are used, at elevated temperature and humidity - with fiberglass or fluoroplast insulation.
If it is necessary to protect against external electrostatic fields, the installation is carried out with shielded wires and cables with mandatory grounding of each shield.
Part of the installation wires, especially those with rubber insulation, are supplied with tinned conductors. This preserves the electrical resistance and mechanical strength of the copper wire in rubber or vulcanized rubber, and speeds up the process of preparing wires for mounting and soldering.
When designing, the tolerances for the harness parameters can be determined analytically. When calculating the dimensional chain, they take a wire with a margin for soldering and compensation for bends at contact connections. The deviations of the master link must take into account the tolerances for the geometric dimensions of the frame, the fastening of the bundle, the length of the wires during layout, the installation of technological studs on the template.
The initial development of the harness design is carried out as follows. On the assembled frame, wires are laid according to the mounting or circuit diagram. The ends of the wires are marked on both sides with tags indicating the route number (^ -2; 1 -6; 3 -5 etc.), after which their length is measured and the data is entered in the table of field connections.
The sketch is used to develop a template and. in particular, to determine the placement of technological studs. An experimental harness is assembled on the template, and after it is installed on the frame, the template is adjusted.
2. Manufacturability analysis
Technological design is called, which, at the lowest cost, is the easiest to manufacture. Technological design should include:
1. The widest possible use of unified assemblies, standardized and normalized parts of the elements of parts;
2. Perhaps a smaller number of parts of the original and complex shape and various names, as well as a large repeatability of parts of the same name;
3. Creation of parts of a rational form with easily accessible surfaces for processing and sufficient rigidity in order to reduce the labor intensity and cost of the entire product;
4. It should be rational to assign the accuracy of the size and class of surface roughness;
5. The presence of basing surfaces on the details;
6. Most rational way obtaining blanks for parts (castings, stampings with sizes and shapes that are as close as possible to finished parts, i.e. providing the highest material utilization rate and the lowest labor intensity);
7. Complete elimination or possibly less use of fitting and fitting work during assembly by manufacturing interchangeable parts and mechanization, automation of assembly work;
8. Simplification of assembly and the possibility of parallel assembly in time and space separate parts products;
9. The design should be easy to assemble and disassemble, as well as provide access to any mechanism for adjustment, lubrication, repair.
The design being developed is technologically advanced, since it provides for:
1. Perhaps a smaller number of parts of the original and complex shape and various names, as well as a greater repeatability of parts of the same name;
2. Creation of parts of a rational form with easily accessible surfaces for processing and sufficient rigidity in order to reduce the labor intensity and cost of the entire product;
3. Simplification of assembly and the possibility of parallel assembly in time and space of individual parts of the product;
4. Complete elimination or possibly less use of fitting and fitting work during assembly by manufacturing interchangeable parts and mechanization, automation of assembly work.
3. Technological route for the manufacture of the tow
The technological route for the manufacture of a bundle is the following sequence of operations:
1. Preparatory operation
2. Equipment
3. Preparation of installation wires
4. Wire layout on the template
5. Knitting a tourniquet
6. Control
4. Detailed description of the main operations
1. Preparatory operation
2. Equipment
3 . Ppreparation of installation wires
Preparation of installation wires consists of the following operations: dimensional cutting, removal of insulation and termination of wire ends, marking, maintenance and twisting of wires. If the technological process provides for a continuous layout of the wire on the template, then cutting, removing insulation and terminating the ends is carried out after the formation of the bundle.
Wire cutting by hand simple tools(scissors, wire cutters), determining the length of the wire according to the sample or using a ruler. In mass production, this operation is automated. Universal are machines for measuring cutting and simultaneous removal of insulation from the ends of the wire.
Depending on the type of insulation used various ways stripping: notch , electric firing or thermal softening with subsequent mechanical contraction of the insulation, and certain ways termination of wire ends.
Textile, plastic and film insulation is removed by incision or electric firing. The removal of multilayer insulation has a number of features. So, in the presence of fiberglass, the outer plastic insulation is removed by electric firing, and the inner (fiberglass) is untwisted, twisted and cut off at a distance of 1 mm from the end of the outer insulation. Outer textile braids require stepped cutting of the ends of the wires. For example, between a cotton braid and a residential wire, a section (3-10 mm) of the main PVC or rubber insulation is left. The end of the braid is fixed with glue, an insulating tube or a thread bandage coated with glue.
Stripping of heat-resistant fluoroplastic insulation is carried out by electric firing at an elevated temperature of the filament. This releases toxic gas - fluorine, which must be removed from working area with a suction system.
The stripping must preserve the quality of the non-removable insulation, exclude a cut or break in the current-carrying conductors and be sufficiently productive. In addition to machines for cutting wires and stripping insulation, special devices have been developed for thermomechanical stripping. Their main working elements are a filament and sponge-knives.
The thread burns through the insulation when the wire is rotated around its axis. Sponges are a support for the wire when burning the insulation, protect it from charring and the thread from mechanical damage, provide insulation together with the thread. The working edges of the jaws have a rounding radius of 0.08 mm and are polished, which will exclude a notch and a break in the current-carrying wires. Insulation stripping devices - can be equipped with a device for connecting to a vacuum system for suction of toxic products of insulation burning. The thermomechanical method allows you to remove insulation in one step from wires with a cross section of 0.07-0.35 mm 2.
For installation, shielded wires and RF coaxial cables are used, having an outer PVC coating on top of the shielding braid. The separation of the coating by notch is laborious and does not provide High Quality end splits.
The thermomechanical method allows you to remove the plastic insulation within 2-3 seconds without damaging the braid.
sponge knives , equipped with heaters penetrate the insulation and cover the shielding braid in diameter. The section of insulation inside the jaws heats up and expands, making it easy to remove it by pulling it off the end of the wire.
Further cutting of the ends of the shielded wires is to remove the shielded braid in a certain area. One of the removal methods is a circular cutoff of the braid using a punch-die cutting pair.
The working part of the punch is made in the form of a cone, turning into a sphere, which allows it to move quite easily inside the braid and provides an even cut of the screen end on the sharp edges of the matrix . The method is implemented with the help of devices of various designs, which make it possible to cut off in 3–4 s.
There are other ways to remove the shielding braid: a helical cut with rotating cutters and knives, cutting off the annular thickening of the braid.
To extract the end of the insulated wire through the shielding braid, the core is pulled apart with a sharp tool: the braids and the wire are pulled through the hole formed. The most common tool is a grooved needle, which is inserted from the end of the shielded wire between the braid and the insulated wire. In a certain place, the tip of the needle pushes the braid apart and, using the eye of the needle, pulls out the end of the wire. This operation is performed in 3-4 seconds manually, guiding the needle using simple devices.
Termination of the ends of shielded wires consists in grounding the shields or fixing the end of the braid relative to the wire. Grounding is carried out by attaching the free end of the braid to the elements of the frame, soldering an additional wire, applying a bandage of bare tinned wire, and then soldering it. Soldering points are protected with insulating tubes.
A non-grounded braid is terminated between two insulating tubes, one placed under the screen and the other outside or between layers of insulating tape. The end of the braid is fixed with a thread bandage or a wire bandage, followed by soldering.
After removing the insulation, the bare ends of the wires are stripped, and the stranded wires are twisted at an angle of 15-300 to the wire axis. last operation performed manually (core cross section less than 0.11 mm 2), with pliers or with the help of special devices. The prepared ends of the wires are subjected to hot tinning by immersion in a solder bath.
Wire marking is necessary to facilitate installation, control, troubleshooting and repair. Use wires with colored insulation and mark them with tags, adhesive tapes or by applying markings directly to the wire insulation. Colored insulated wires are usually used for internal installation EVA. The wiring diagrams indicate the color of the mounting wires with abbreviated symbols or digital codes. Wire marking sticky tapes consists in applying bandages from this tape to the ends of the wires. Marking with the help of marking tags made of polyvinyl chloride tubes has received the greatest application. The tag is attached to the end of the wire. In this case, the tag should overlap the edge of its insulating braid by 1-3 mm. The tags are put on the wires in such a way that their slipping during shaking and vibrations is excluded.
Symbols on the surface of the marking tags are specified in wiring diagrams and are carried out in accordance with industry standards. The production of tags (marking, drying, cutting) is carried out on special machines. Mounting wires are twisted to eliminate electrical interference and reduce the mutual influence of circuits. The stranding pitch is 10-40 mm and increases depending on the increase in the wire cross-section (0.05-0.75 mm 2). This operation is performed manually with a drill or on special machines.
4 . Wire layout on the template
harness mounting wire isolated
Structural and technological development of the harness makes it possible to manufacture it outside the EVA by laying out the mounting wires and cables on the template. Depending on the configuration of the bundles, flat or three-dimensional templates are used. A flat template is a base on which, in accordance with the routing (see Fig. 2) and the configuration of the bundle, metal studs are located. Installation wires are laid between the studs. To protect the wires from damage, insulating tubes are put on the studs. To fix the ends of the wires, the design of the template provides holes located next to the studs, or special clips. Volumetric template It has additional elements, allowing you to lay out the wires and fix them in three planes.
There are universal flat templates that have holes located with a certain pitch and are designed for installing studs. The layout of the studs on the template can be changed depending on the routing and bundle configuration.
Designs of electrified templates have been developed that increase the productivity of harness manufacturing and eliminate installation errors. On such a template, the ends of the mounting wires are fixed with special clamps electrically connected to signal (green) and control (red) lamps. The lamps and clip-buttons are switched in such a way that when the template is connected to the network, two lamps of the first route light up. At correct styling and fixing the wire, the lights of the second route light up, etc. Electrified templates are more expensive than conventional ones, and it is advisable to use them in the mass production of EVA.
When laying out wires on templates, some general rules. Several bundles should be made from wires of different cross-sections, combining wires that are close in diameter. insulation (eg 1 to 3 and 3 to 6 mm). Shielded drives must be located inside the bundle, so they start the layout with them. The screens are pre-cut and soldered, in the presence of an external metal braid, it is wrapped with a keeper tape or insulated with a tube. Short wires of small cross sections are laid inside the bundle. Long wires are laid outside to form the front side. Spare wires should be on top with access to their ends. These rules are easy enough to follow when laying out manually.
The sequence of wire layout on the template is manually set in the connection table, taking into account listed rules. Often a drawing is placed on the template with the designation of the tracks. The end of the wire wound from the coil is marked with a tag and fixed on the template. The wire is cut in place after laying out between the studs and its end is marked. These transitions are repeated many times. The cutting of the ends with such a sequence of operations is carried out after knitting the bundle. Manual layout on the template is performed by the installer, and it is very laborious. In serial production, it can be mechanized using a program-controlled device.
5 . Knitting harnesses
Two (or more) insulated wires with a length of more than 50 mm running in parallel along the same route must be bundled. The only exception can be an unacceptable increase in mutual pickups in electrical circuits. For knitting, threads, cords, braid, insulating tapes, heat shrink tubes, etc. are used. The operation is usually carried out on a template. Knit step t depends on wire section, number of wires n and diameter D tourniquet. On curved sections, the pitch should be reduced depending on the diameter of the bundle bend. At the branching of the wires, the knitting should have 2-5 turns on all branches, the bandages should be made from 2-3 adjacent loops. The ends of the bundle must have bandages and end nodes.
Knitting is carried out in one, two or more threads with manual tension or with the help of devices. To reduce the complexity, the process of knitting harnesses is mechanized using pneumatic guns, and sometimes automated, by knitting harnesses on special semi-automatic machines.
To protect against mechanical damage, the tourniquet is wrapped along the entire length or in a certain area insulating tape. If it consists of wires with cotton or silk insulation, then to protect against moisture, the bundle is impregnated with a water-repellent composition. To protect against high temperatures or aggressive environments, the bundles are placed in tubular, tape, strip or woven sheaths. removing the harness from the template.Thus, knitting harnesses is no less time-consuming operation than laying out and marking wires.
In addition to the use of various devices for the mechanization of the operations of manufacturing a tow, it is advisable to use conveyor lines in conditions of mass production. In this case, the technological process is divided into a number of small operations. At each workplace, the layout of wires of the same section and brand is completely carried out. When determining the cycle of the conveyor, they are guided by the layout operation, based on the fact that the knitting operation is easier to subordinate to the selected rhythm. For example, knitting 16-24 loops takes 3-5 minutes. Most often, the cycle of work is 5 or 7.5 minutes.
The conveyor method of making harnesses has other features. The layout of the wires is carried out continuously, winding them off the coils. A set of tags is preliminarily put on the end of the wire to mark all routes performed at a given workplace.
Universal templates are used, equipped with studs both in places of kinks and branches, and in places of subsequent cutting of wires. The layout routes are marked with the help of special stencils placed on the templates. For knitting harnesses, threads are used that can withstand sufficiently large tension forces. After knitting, the wires are cut, the bundle is removed from the stencil and the ends are cut.
The conveyor for the production of bundles is located in a horizontal plane, closed and transports templates using trolleys. In addition to templates, it is equipped with guns for knitting harnesses, devices for stripping insulation, and a tinning unit. The conveyor method simplifies the operations performed at each workplace and reduces the overall complexity of the production of harnesses. Its disadvantages are the tension of the wires during layout and the deformation of the bundle after removal from the template, which worsens the quality of knitting.
6 . Co.control
After the harness is made, the quality of the termination of the ends of the wires and screens, the presence of markings, the absence of damage to the current-carrying conductors and insulation, and the quality of tinning are controlled. Integrity electrical circuits check with probes. In circuits with a large number of intermediate connections, the resistance is measured.
During the control, the ribbon cables are checked for the absence of conductor breaks, the insulation resistance between the conductors and the ground buses, the presence of electrical connections between the connector contacts and the ribbon wire.
For control, special automated stands have been developed, for example, with the number of points to be checked is 90 and the main technological time for checking the product is not more than 30 s. The control is carried out by checking the electrical circuits, comparing the states of the switches and then transferring the results to the light indication panel. Stands can work in automatic and manual modes.
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Requirements for the installation of protection devices that are not resistant to maximum current values. Power box installation technology: marking the installation site of electrical equipment, fittings and shields, punching holes, installing fasteners, laying wires.
The invention relates to electrical engineering, in particular to the technology of manufacturing harnesses on automated equipment, and can be used in the fields of technology related to the manufacture of harnesses of a large range. The essence of the invention: in order to speed up the process and improve the quality of the product, the stripping of wire sections from insulation and maintenance of the stripped wire sections are carried out simultaneously with the unfolding of the continuous wire on the template between the trace and end pins, and the distance between the stripped and tinned sections on the continuous wire is chosen equal to the distance between the end pin and the end surface of the nozzle of the laying head, and the length of the processed section of the wire is selected from the expression L=K(1/2d w +d pr)+2l k, where k is a coefficient that takes into account the deformation of the wire when the template pin is bent; d w - pin diameter, mm; d mr - the length of the processed section of the wire, mm; l to - the length of one processed end of the wire, mm. 1 ill.
The invention relates to electrical engineering, in particular to methods for manufacturing harnesses on automated process equipment, and can be used in the production of highly branched harnesses of a large range. A known method for manufacturing a harness mainly for printed circuit boards, including laying out the wire on the pins of the template, cutting the wire in previously stripped and tinned areas, transferring the harness from the template to the printed circuit board, matching the wires of the harness with the pads of the printed circuit board and desoldering the wires of the harness, and transferring the harness to the printed circuit board is carried out after combining the wires of the bundle with the contact pads of the printed circuit board and their desoldering. This method has the following disadvantages: its inefficient use in the production of inter-board, intra-unit, rack harnesses; high coincidence error of pre-prepared sections of the wire with the pins on the template when large numbers wires in the bundle; in the event of a failure in the process of laying out or a break in the wire being laid out large segments wires have to be removed, either returning to their original position and starting the layout from the beginning, or skipping one circuit, which can be further expanded manually, as a result of which errors and loss of time are inevitable, additional expense wires; for pre-training wire runs required optional equipment cleaning and tinning, as well as new programs and media. The closest technical solution, chosen as a prototype, is a method for manufacturing harnesses, including stripping sections of wires from insulation by a laser beam through mask windows, servicing sections of wires stripped of insulation, laying wires on a template, cutting wires and transferring the bundle to an electronic unit, moreover stripping of sections of wires from insulation is carried out after laying out the wires on the template. Main Feature The way to ensure high accuracy of the place of stripping the wire from insulation is stripping it directly at the location of the end of the bundle branch. However, the known method has the following disadvantages: laser processing materials, therefore, each type of harness requires its own mask, which is extremely disadvantageous when small-scale production harnesses. 2. The use of a laser significantly lengthens the technological chain due to the creation of specific conditions for its operation (cooling systems, blocking) and the solution of protection issues environment from harmful fumes of insulation under the influence of a laser, as well as compliance with technical safety conditions for service personnel. 3. After annealing the insulation on the wire sections, it is subsequently necessary to maintain them by well-known methods, with a certain amount of time, which does not big win in labor productivity. The purpose of the invention is to speed up the process of manufacturing harnesses and improve the quality of the product. The goal is achieved by the fact that in the manufacturing method harness products, including laying out a continuous wire on a template between the trace and end pins using a laying head with a nozzle, stripping wire sections from insulation, tinning wire sections stripped of insulation, cutting the wire and transferring the bundle to an electronic unit, while stripping wire sections from insulation and maintenance of the stripped wire sections is carried out simultaneously with the unfolding of the continuous wire on the template between the tracing and end pins, and the distance between the stripped and tinned sections on the continuous wire is chosen equal to the distance between the end pin and the end surface of the pipe of the laying head, and the length of the processed wire section is selected from the expression L= K (1/2d w +d pr)+2l k , where K is the coefficient that takes into account the deformation of the wire when the template pin is bent; d w - pin diameter; d pr - diameter of the processed section of the wire, mm; l k - length of one processed wire end, mm. Comparison of the proposed solution with the prototype shows that the proposed method is novel, since, unlike the prototype, it allows automated processing of the ends (cleaning, fluxing and tinning) of the bundle branches directly in the process of continuous wire layout on the template, therefore, it meets the criterion of the invention "novelty" . Comparison of the proposed method with other technical solutions shows that none of them contains the above set of claimed hallmarks . In the known methods, the processing of wire sections according to a given program is carried out either before the wire layout on the template, or after it. In the claimed technical solution, the processing of wire sections is carried out directly in the process of continuous layout, thereby eliminating the inherent disadvantages of known methods. This allows us to conclude that the proposed method meets the criterion of "significant differences". The drawing shows a fragment of the layout of the bundle with the simultaneous preparation of a section of the wire. The inventive method for the manufacture of bundled products is implemented as follows. The layout of a continuous wire is carried out on a wire layout machine. A universal template is installed in the machine with pins fixed in it, which determine the topology of the future harness. A program is introduced into the program control system of the machine, which describes the layout route and determines the sequence of technological commands. The unprepared wire 1 is placed on the coil 2, from which, in the process of continuous layout, it enters the template 3 with the pins 4 fixed in it and hooks on them. The ends of the wires in the bundle must be processed to a length determined in the design documentation, for example, 10 mm. Measured processing, as you know, includes stripping the insulation on the wire and maintaining the stripped area. Such processing of sections of the wire continuously supplied to the coils is carried out by the device for dimensional preparation of the wire 5 (UMP). The layout process begins with fixing the beginning of the wire and turning on the UMP, which processes the section of wire 6 corresponding to the beginning of the first circuit. After turning on the machine, the stacking head 7 begins to move relative to the origin of the template for a length equal to the distance R between the nozzle 8 of the stacking head 7 and the UMP. This distance is, for example, 150 mm. Further, in accordance with the layout route, the wire goes around pin 9 on the template so that the section stripped on the wire is not deformed. Then the laying head moves along the coordinates, depending on the topology of the first circuit, and r=150 mm before the end pin that combines the first and second circuits, the UMP is turned on, a section of wire is processed in it for a length determined by the formula L=l p +2l to , where l to - the length of one machined end of the wire; l p - the length of the technological jumper that occurs when the wire is wrapped around the pin and which must be removed during the trimming process. The length of the technological jumper can be estimated by the formula l K (1/2d w +d pr), where K is the coefficient that takes into account the deformation of the wire when the template pin is bent; d w - pin diameter;
d pr - the diameter of the processed section of the wire. Assuming that l p can be equal to, for example, 4 mm, at the end pin that combines any two consecutive circuits, the wire section is processed, for example, to a length L=4+2x10=24 mm. Then the next chain is laid out according to the program, the process is repeated until the level of the layout rises, depending on the device of the laying head, by the value h, due to engagement with the tracing pins more wires. As h increases, the UMP is switched on according to the program at the moment when the distance between the end surface of the pipe of the laying head and the end pin will be determined as r=R-h. In our example, this distance is 150-10=140 mm. When laying out the last chain on the template, the wire is processed, 10 mm long, after which the laying head, moving further along the route, goes around the end pin so that the processed area is not subjected to deformation. Subsequently, the wire laid out on the template is tied according to the drawing, all, except for the extreme, processed sections are cut in half, technological jumpers are removed and the finished bundle is transferred to the electronic unit. The use of the method is most effective in the manufacture of bundles of a large (several hundred) number of wires, since it ensures high accuracy of matching of the processed sections of the wire with the pins and the process of processing sections of the wire does not depend on the number of circuits in the bundle. The use of the proposed method for the manufacture of bundled products provides, in comparison with existing ways the following benefits:
1. Due to the combination of wire layout and processing processes, the technological capabilities of the wire layout machine have been expanded. 2. Significantly increased the productivity of the process of manufacturing harnesses by reducing the time for processing the ends, which is carried out automatically, efficiently and safely. 3. The quality of wire products is improved due to the exclusion of monotonous manual labor. 4. Working conditions are improving. 5. In addition, the use of the proposed method does not require additional capital investments. 6. The use of the proposed method allows you to maximize the benefits of a universal template for the manufacture of highly branched bundles.
Claim
METHOD FOR MANUFACTURING HARNESSES, which includes laying out a continuous wire on a template between trace and end pins using a laying head with a branch pipe, stripping wire sections from insulation, tinning wire sections stripped of insulation, cutting the wire and transferring the bundle to an electronic unit, characterized in that, in order to speed up the process and improve the quality of the product, the stripping of the wire sections from insulation and the tinning of the stripped wire sections are carried out simultaneously with the unfolding of the continuous wire on the template between the tracing and end pins, and the distance between the stripped and tinned sections on the continuous wire is chosen equal to the distance between the end pin and the end surface of the nozzle of the laying head, and the length L of the processed section of the wire is selected from the expression
L \u003d K (1 / 2d w + d pp) + 2l k,
where K is the coefficient taking into account the deformation of the wire at the bend of the template pin;
d w - pin diameter, mm;
d pr - diameter of the processed section of the wire, mm;
l to - the length of one processed end of the wire, mm.
Knitting harnesses
The basis of every electrical product is conductors. In our age of miniaturization, many of them are being integrated into printed circuit boards, walls and panels, can be made in the form of ultra-thin loops, transparent coatings and much more. However, the lion's share of the circuits is still connected by separate isolated copper wires and cables, which are combined into bundles for ease of installation and repair, more stringent standardization of parameters and simplification of access to various units.
Knitting harnesses is one of the most common operations in the general cable processing process, the manufacture of cable assemblies. In principle, it is produced after cutting and stripping the cables. But often (especially when many wires of the same type are used in the bundle that do not require complex stripping), cutting can be done directly on the knitting template after laying the wire along the route. That is, depending on the materials used, production conditions and the characteristics of a particular product, operations can be mixed and interchanged. This requires their implementation in the course of a single technological process, in any case, at one enterprise. LLC "CEPIKS" is one of the leaders Russian market in this specialization.
Knitting is a general term. In fact (in accordance with the specifications for specific bundles), wires can be fastened not only with a thread, but also with all kinds of clamps, ties and tapes, leather cases, special polymer bandages and so on. The material and method of knitting is determined by the type of wires, the conditions of installation, storage and operation of the equipment, the location of the bundle route in the product in relation to sharp, moving, heating elements. In some cases, knitting with a thread is even unacceptable: in flexible areas where the wires must move freely relative to each other, inside insulating tubes (sheathing, windings), on wires and cables with insulation made of polyethylene, fluoroplastic and other materials with cold fluidity.
When knitting bundles, special attention is paid to shielded wires, the braids of which must be isolated from each other and from the device case, if this is not allowed by the electrical circuit. They are also enclosed in solid smooth dielectric tubes in areas where the bundle can be bent during operation. Additional insulation is also applied to the bundles at the points of their transition through sharp edges and holes in the structural elements of panels and devices. A reinforced bandage made of thread (or an additional tie) fastens the places where the wires branch from the trunk of the bundle, the edges of the flexible sections and some other key points.
Harnesses are knitted, as a rule, on templates specially made according to technical documentation - shields with pegs for turns and wire branches, providing the necessary bending radii and matching the shape of the harness to its route according to the project. Methods of knitting and layout of wires in bundles, depending on their cross-section, type and functional purpose, are standardized by GOST 23586-96, wire cutting and fastening designs - by GOST 23587-96, and requirements for cutting and connecting screens - by GOST 23585-96. Immediately, stripping, dialing and marking of cables is usually performed (since the wire numbers are signed directly on the shields), and their tinning or installation of lugs after removal from the template.
final stage harness manufacturing is its testing on special equipment with a thorough check and recording of all electrical and mechanical parameters.
Manufacturing cable harness products
Cable harness products are used for switching nodes, boards, blocks and switching racks in many industries. They can differ both in the degree of complexity (from a single-core conductor between two contact pads, to a combined bundle with a complex switching table), and functional purpose(ground wire, coaxial cable, fiber optic cable, etc.)
Regardless of the complexity and purpose, the cable assembly must meet the following quality criteria: reliability of signal transmission from the start to the end point; minimum loss of signal characteristics; ease of switching the harness in electrical equipment; durability of terminal connectors, contacts and connectors during the operation of electrical equipment; maintainability during service.
The manufacturing process of cable harness products (cable assemblies) is divided into several production stages:
Measured wire cutting
wire stripping
Crimping cable lugs (cremping)
Installation (assembly) of connectors
Knitting (installation) of harnesses
Wire (cable) marking
Preparation and installation of a special cable
Quality control and compliance terms of reference
Even at the design stage, factors affecting the characteristics of the harness are determined. They form the basis of the technological process for the manufacture of cable assemblies. dimensions, type of wire (cable), section, external diameter, installed contacts and connectors, marking, bandage and strapping - all these stages are strictly verified in the production process chain.
The production of cable harness products is carried out on assembly stands (with the exception of jumper wires). They allow you to minimize errors when knitting and bandaging harnesses, as well as reduce production time. Also on the stands there is an opportunity to check specifications harness knitting.
Checking the quality and compliance of the cable assembly with the terms of reference is checked at all stages of the production of the wire harness and at the final control (output control of the enterprise). All discrepancies are recorded in the test reports, on the basis of which a statistical analysis is carried out. Necessary adjustments are made to the manufacturing process, materials, terms of delivery of components, design and technological documentation.
ELECTRICAL HARNESS PRODUCTION TECHNOLOGIES high requirements to build quality and reliability. Accordingly, each unit and part of the car must meet these requirements. An integral element of the car is the electrical wiring (wiring harnesses). A wiring harness is a finished product consisting of individual wires fastened together in a bundle, the ends of which are reinforced with contacts that are assembled into blocks or protective elements (tubes, rubber caps, covers) are put on them. The wires are fastened into bundles: bandages made of PVC adhesive tape, cable ties (toothed clamps made of thermoplastic polymers); heat shrink tube.  A modern car has harnesses with a total number of wire segments of about three hundred (and more often more), reinforced with various contacts. The reliability of such complex product depends on several factors. First of all, these are increased requirements for the quality of components and materials. Which, in turn, is influenced by the choice of supplier and the conduct of incoming control. The next factor is the use of modern high-performance and precise production and control - measuring equipment that meets the requirements of international standards. And, finally, the most important factor of reliability is the specialists involved in the production process. The quality and reliability of the product depends on their professionalism. Autotractor harnesses can be divided into: low and high voltage(battery and starter wires are most often single, less often - consisting of two to three wires).  The technological process of manufacturing a wire harness is divided into several basic operations: cutting wires, stripping the ends of wires from insulation, reinforcing wires with lugs or contacts, fastening wires into bundles (binding), installing detachable connectors, quality control. In order for you to better understand what components the wiring harnesses consist of and in what sequence they are used in their manufacture, we tried to give detailed description basic operations for the manufacture of harnesses and types of equipment used. For more better understanding assembly sequence of any harness in this section we will introduce general concepts bundle structures, which will be found later in the text. The harness can be divided into parts and give them names.
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