Site layout knitting harnesses and cables. Layout and knitting of mounting harnesses. Automated lines for the production of CS and harnesses, types of equipment, advantages, distribution
It's nice to have a girl in our midst. Her name is Elena. She is from the city of Rybinsk, Yaroslavskaya oblast. Here is what she writes about herself:
Good afternoon! I want to write about electrical harnesses for cars and motorcycles. Do's and Don'ts available materials, personal experience. I work as a design engineer, designing harnesses and wiring for piston engines.
So, Elena's article.
About electrical harnesses
The harness is a set electrical wires and cables used for communication various elements electromechanical or electronic systems.
The purpose of the harnesses is to provide power or transmit electronic signals to various peripherals. The harness consists of at least two wires.
Photo 2 - Harness on the assembly table (www.knaapo.com)
This is what professionally made car harnesses look like:
Photo taken from JDMParts blog on drive2.ru
This is what aviation harnesses look like (aer.interelectro.com.ua):
Materials and components for the manufacture of harnesses
The materials used in aircraft harnesses are highly reliable and can also be used in military equipment. For example, heat shrink tubing from Raychem and Deray. After shrinkage, they are quite soft (unlike cheap tubes), resistant to abrasion.
Separately, it is worth mentioning the connectors used. For Russian technology, cylindrical and rectangular connectors are used, for example: SNTs, RSTV, ONTS-BS, 2RMD, 2RMDT (photo 6), in a metal case.
Any harnesses consist of the same components:
– wires (power and signal);
- connectors, lugs, terminal blocks;
– protective materials (winding tape, corrugated and heat-shrinkable tubes, protective sheaths and stockings);
- harness fastenings (clamps, holders).
The difference in price between special materials and what we use for ourselves - at home or in the car - at times.
There are many specialty electrical materials, but they tend to be very expensive or rare. And often we simply do not know what to use (this applies to materials and tools) in a particular situation, and this is where the “collective farm” begins.
Wires for making bundles
Where do we start? From wires. When choosing, be sure to pay attention to the operating temperature, insulation resistance to gasoline, oil, and combustion resistance.
Take stranded copper wires in insulation of different colors and different sections, for example PV-3. They withstand temperatures from -50°C to +65°C. They are quite common, they are in online stores and in retail. In fact, these were the only wires in a wide range of colors and sections that were found in a store in my city. Unfortunately, this is usually the case.
(photo 7).
Photo 7 - Materials, tools and wires for the production of harnesses
Need to cut off required amount. You can measure the length with a rope or wire, laying in place. It is necessary to leave a margin in length for triple re-embedding into contacts or lugs (a few centimeters from both ends). After twisting, the wire will become even shorter, do not forget. The wire should not be taut, especially near the connectors. If you are not sure - take a longer one, you will always have time to cut it off.
In general, if the wires go together at least 50 mm, they are combined into a bundle. It is forbidden to lay power and signal lines in one bundle. This means that the wires from the sensors and the wires from the powerful consumers should follow different paths and be as far apart as possible. An extreme case is a wire from a sensor and an armored wire from a candle.
The winding of the wires can be fixed with a tape or a special thread. FUM tape is available for household practice (in industry, SKLF-4D fluoroplastic film is used, FUM tape is also made of fluoroplastic, a non-combustible electrical material). The winding is carried out in the opposite direction of the winding. (photo 8).
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Photo 8 - twisted wires
Stranded wires are more flexible than just folded together and covered with some kind of sheath.
The upper shell is corrugated, heat-shrinkable tube.
These are the most common materials used in private practice to protect wires. Sometimes they wrap the wire with electrical tape along the entire length, this is not necessary. The glue decomposes over time (especially from heat), the wire will remain sticky, in the end it does not look very good (photo 9).
The corrugation is split and continuous (with a probe for broach - wire). Split can be put on a ready-made harness with installed connectors.
No need to fill the entire corrugation with wires, let a little remain free space(more details in paragraph 5.9 - GOST 23586-96) In the end, you may need to lay a few more wires. Sometimes they put spare wires in the bundle, their ends must be closed, because. the wire is a capillary pump, liquid getting inside will cause corrosion.
Photo 11 shows a way to seal the insulation of a spare wire, it consists in the fact that a piece of heat shrink (the presence of an adhesive layer is not important) is put on so that at least a centimeter and a half is not put on the wire and treated with a burner. Until it cools down, we squeeze the free part of the tube with our fingers, it will stick together. All.
The use of heat shrink in the production of electrical harnesses
It would seem that the split corrugation is leaky, what is the use of it? It will not allow the wires to fray on sharp edges, unlike inexpensive heat shrink. There is a minus - the corrugation will not withstand a high temperature.
Instead of a corrugation, a tourniquet along the entire length can be put on heat shrink.
Conventional heat shrink HERE has an operating temperature of -55 to +105°C, a shrinkage ratio of 2:1. This means that a size 8/4 tubing has a diameter of 8 mm before shrinking, 4 mm after shrinking. The closer the diameter of the bundle to the diameter of the unshrinked tube, the smaller the wall thickness after shrinkage, therefore, it is worth choosing a tube so that the diameter of the bundle is approximately in the middle of these dimensions.
To shrink the tube, you can use matches, a lighter, a burner, building hair dryer. The main thing is to monitor the uniformity of shrinkage and not burn it (for any tube, the manufacturer writes the temperature of its full shrinkage). It is inconvenient to do this with matches. Honestly. A small tube can still be seated at the soldering point of one thin wire, something more can not.
Professional option - (actually a good thing, great for working with wood and leather when waxing, will help remove old paint, will heat the part when replacing bearings). It has a temperature control over a wide range, shrinkage is even and not too fast.
I use soldering torch, she fills up with gas for lighters (photo 12).
The flame has a high temperature, so everything must be done quickly and carefully so as not to burn the pipe. On my own, I recommend purchasing such a burner, it will help when working with heat shrink, when soldering massive parts, and in other cases. But you can do without a hair dryer.
The branching of the wires hidden in the corrugation is carried out using a collapsible tee (photo 13)
I didn't have any triplets. I had to use tape, even though I don't like it. The edges of the tubes are inserted into each other and carefully wrapped.
For branching, there are cable heat-shrinkable cable gloves (photo 15)
Photo 15 - cable heat-shrinkable gloves
Great thing, but I saw these in retail stores once, and then they are for cables large diameter. If you are a fan of your craft, you will surely want to use these products. They are in online stores (but you have to look), for example, the KBT plant (Kaluga) will soon produce such products (I advise you to visit the KBT catalog on their website).
Stripping
Photo 16 - Stripper
It is carried out with a special tool - a stripper (photo 16)
He cuts the insulation, not reaching the core, but so that it can be torn off and moved. I strongly doubt that someone uses such a tool in everyday life (for example, I don’t have one). Do not listen to someone who tells you “and I cut the insulation across the wire with side cutters / cutters / knife” this is done at your own peril and risk, you cannot be sure that the blade did not reach the wire cores. "By eye" it is very difficult to adjust the depth of the incision.
I do like this. But you need to be confident in your tool, hands and wire insulation! Yes, and after 10-20 such removals, corns begin to appear! (Note SamElectric.ru)
One of the stripping tools is a mounting knife, straight or with a heel (photo 17). With some skill, insulation can be used with a clerical knife instead of a straight mounting knife. The insulation is cut with chips, as if sharpening a pencil, but trying not to cut the wires.
I use a utility knife extensively. Especially when stripping cables. To do this, I cut the outer insulation lengthwise, trying not to cut the inner, individual one. And in a single wire I remove the insulation (when there are no wire cutters, or in difficult cases), cutting the insulation around.
Defense companies used insulation burners, which are similar to wood burning tools. red-hot nichrome wire insulation is burned in a circle and then removed. Suitable for MGTF and other wires. Similarly, you can remove the insulation with a soldering iron (photo 19). Minus - the smell and harmful fumes.
Photo 19 - Removing the insulation with a soldering iron.
Photo 19-2 - Removing the insulation with a soldering iron.
Soldering or crimping wires
In general, crimping is better in terms of vibration resistance. When soldering, at the point where the wires come out of the solder, they are more likely to break off if they are subjected to vibration (photo 20).
A properly made crimp is stronger than the wire itself, but how many people have a crimp at least for auto-terminals at home? That's right, no, I have too (but in general the crimps look like this - photo 21). So let's solder.
I have both a crimp and a stripper. I already wrote about crimping wires with tips.
Important: never use acidic fluxes when soldering wires, no matter how tempting it may sound. Because the wire is a capillary pump and you still can’t wash out the flux residues from there, no matter who tells you what. Soon there will be corrosion.
It is convenient to use rosin dissolved in alcohol. Pour this solution into a bottle with a brush, such as nail polish.
It is convenient to use flux LTI-120 with a brush. Or rosin in a jar, I write about it.
Connector covers
- protect the contacts inside from water and dust, provide mechanical adhesion of the connector body and wire. They are sealed or non-sealed.
In the photo 22 connector long time worked without a casing, the wires were often bent and moved, the cores were partially broken near the contacts (the wires were connected by crimping, but the cause of the malfunction was precisely in the absence of a casing).
Photo 22 - Connector without casing
Sealed casings are made of heat-shrinkable materials with an adhesive layer. The same tube, just a different shape. You can easily use a piece of regular tubing, but the fact is that the diameter of the back of the connector and the diameter of the cable have a very large difference that ordinary heat shrink at a ratio of 2:1 does not cover. Simply put, it will sit on the connector normally, and the wire will hang out. You can look for tubing with a shrink ratio of 3:1 or more. They do exist, but they cost more.
23 - Heat shrink connector cover
In photo 23, a piece of ordinary heat shrink was used, a corrugation of a larger diameter was taken (only 2 wires inside). It should be noted that the softening temperature of the corrugation is approximately equal to the shrinkage temperature of the tube, so you need to work with the burner quickly and carefully, trying not to overheat anything.
Photo 24-1 - Before and after
Photo 24-2 - new electrical harness set
Sealing
If necessary, special mastic is poured inside the casing to seal the contacts. In private practice, you can use silicone automotive sealant. Large volume will dry for several days. If this is really necessary, try to be patient and pour in parts, or at least smear the critical parts with a thick layer.
Important: never use acid curing sealants, corrosion will not take long.
If you open the tube and the smell of acetic acid hits your nose, do not use it. If it does not smell, you can use it, it is alcohol-based neutral.
As a rule, acid sealants are cheaper (ABRO, RUNWAY), an honest manufacturer will indicate on the package - “Contains acetic acid”. If there is no such inscription, carefully read the composition and google each of the components. The composition of the sealant that I bought contained methyltriacetoxysilane - this is a reagent for vulcanizing rubbers, synthesized using acetic anhydride (I do not claim that this component is present in absolutely all acid sealants, please pay attention to the composition when buying).
After opening this tube, it began to smell acetic acid, although the manufacturer has indicated that it can be used for electrical connections. We will not tempt fate, we will leave it for less responsible nodes.
Bundle laying
The installation order is:
- we place the tourniquet in place, temporarily fix it with ties;
- connect all electrical connectors;
- we fix the bundle in place, starting from the connectors (for example, from the ends of the bundle, where there are smaller terminals to a large common connector).
The harness is secured in place with nylon cable ties. By the way, black ties are more resistant to external influences.
In photo 27 on the left you can see 2 metal clamps that attach the wires to the frame. They can be used, but on condition that the clamp does not fray the wire - locally wrap it with electrical tape, put on a piece of heat shrink, put something on it. Do not forget that the harness should not be pulled tight at the connectors, should not touch sharp corners, dangle too much, or touch very hot parts.
But what if the harness goes into the box and connects there?
This situation simply occurs when a brake light is connected:
The black contraption with a union nut in photo 28 is a plastic cable gland (gland). It is designed just for entering cables into various boxes. Such a thing costs no more than 20 rubles (for small wire diameters). There are metal cable glands (for harsh conditions and critical connections), but in stores they are in best case under the order, the cost is already about 100 r per piece. In addition to the inputs, there are special penetrations and bushings.
Photo 29 - Cable entry on the wire in the analysis
The wire dangles in the connector (yes, anywhere), what else can be done?
If winding with various electrical tapes (PVC or fabric) and fixing with clamps does not suit you, then ...
There is such a wonderful thing - LETSAR silicone tape - electrical insulating heat-resistant self-adhesive rubber radiation vulcanization tape. It is a self-adhesive tape, vulcanized at room temperature. After two days, you get a piece of relatively soft rubber where you wound it.
In aircraft harnesses, it is just wound under rigid metal casings for better compression. I will not describe the properties in more detail, too much text. Sold in spools of 500 g, highly stretched when winding, the coil will last a very long time.
In general, it is worth looking for self-adhesive (self-vulcanizing) tapes of other brands, there is less packaging.
- OST 1 00723-74 Connection of negative wires to the body aircraft. Technical requirements
- GOST 23585-79 Installation of electrical radio-electronic equipment and devices. Technical requirements for cutting and connecting wire screens
- GOST 23586-96 Installation of electrical radio-electronic equipment and devices. Technical requirements for harnesses and their fastening
- GOST 23587-79 Technical requirements for cutting installation wires and fastening cores
- OST 1.01025-82 Shielding of wires, bundles, cables and metallization of aircraft. General technical requirements
Cable tie add-on
It is more practical than plastic ties (clamps) and electrical tape. The main advantage is that it is reusable!
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 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 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 an automated technological equipment, and can be used in the production of highly branched bundles 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 the 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 laid out manually, as a result of which errors and loss of time are inevitable, additional wire consumption; for pre-training sections of wire require additional equipment for stripping 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 unprofitable for small-scale production of 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. An unprepared wire 1 is placed on a coil 2, from which, in the process of continuous layout, it enters the template 3 with 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 area 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, for ease of installation and repair, more stringent standardization of parameters and easier access to various blocks combined into bundles.
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 of the 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, threading 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. electric 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. The methods of knitting and layout of wires in bundles, depending on their cross section, type and functional purpose, are standardized by GOST 23586-96, the design of wire cutting and core fastening - by GOST 23587-96, and the 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.
Manufacture of 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. Overall dimensions, type of wire (cable), cross-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 a 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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The technical equipment of the Contract Manufacturing of our company allows us to carry out such a type of work as the manufacture of small and medium batches of non-standard wiring harnesses with increased requirements for reliability and quality (industrial electronics, automotive technology, mechanical engineering, etc.)
Our specialists have mastered the modern advanced technology of braiding wire harnesses,
for this we use the installation of braiding and shielding harnesses in production Cobra 450/1000.
An additional polyester thread braid over the shielding braid makes it possible to use the wire harness at temperatures up to 120°C.
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If necessary, additional sealing of the connectors with special compounds is carried out.
For maximum automation and acceleration of the technological process of manufacturing harnesses, we have at our disposal various desktop machines for measuring cutting and stripping wires (Komax Kappa 330 and Cosmic 927R), a semi-automatic press for crimping terminals and contacts Metal TT.
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Technological possibilities and limitations in the production of harnesses
Wire types |
stranded stranded and solid copper, single wires |
Types of insulation |
polyvinyl chloride, bonded polyethylene, Teflon (TFE), Tefzel (ETFE), Kynar (PVDF), silicone rubber, fiberglass, Nylon, Mylar, Vulkene, neoprene, Hypalon, other wound or embossed insulation |
Min. section |
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Max. section |
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Min. wire length |
at least 10 mm of insulation must remain |
Max. wire length |
999.5 meters |
Min. stripping length |
3 mm (standard value); |
Max. stripping length |
full stripping: 9 mm on stranded wire, 40 mm on solid wire |
Half-sweep |
41 mm or any combination for a total of 82 mm, on stranded or solid wire |
Lot size |
not limited |
Max. performance* |
1000 wires per hour |
*Performance depends on wire type, insulation, wire length, stripping length, wire size.
Apart from various types harnesses, you can order the production of all kinds of information cables for your equipment from us. We are ready to supply any necessary equipment for the production of your cable products.
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 under conditions high temperature – glass threads followed by impregnation of the bandage with wax or paraffin, sometimes 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, if not in large numbers 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.