Cable bundle wire basic knowledge consulting

The bundle consists of multiple single wires. In general, the number of single wires constituting the bundle is thin, which not only increases the flexibility of the wire and cable, but also improves the reliability of the line connection. Some wire and cable conductors do not require a large cross-section, but they also use a twisted form for the sake of better flexibility or high reliability.
To make a single wire stranded or twisted at a certain helix angle (or pitch), the equipment must meet the following requirements: one is to make all single wires rotate around the central axis of the equipment; the other is to make the stranded product straight Move forward. By changing the cooperation of these two movement speeds, the size of the helix angle can be adjusted so that the stranded or beamed wires produced meet the structural requirements.
The composition of the stranding machine and the harnessing machine are basically the same, and they are composed of the main parts such as payoffs, traction, cable and take-up, dragging and transmission systems, and control systems. In addition, it is also attached to devices such as splitter boards, parallel wire molds (also known as stampers), and meter counters.
The twisting machine produces a larger twisted specification. In addition to a single single wire at the center, all the single wire payoffs are placed on the payout section (such as a twisting cage), and the single wire is twisted around the central single wire through its rotation. Floor. According to the number of twisted layers of the stranded wires and the number of single wires in each layer, the general stranding machine is provided with several (several segments) separately rotating paylines to make the layers twisted to different strands. Concentric stranded strands are particularly suitable. The beam line produced by the wire harness machine has a small size, and it forms a beam line by the rotation of the basket or the rotary body at the take-up portion. Since the operating operations of the wire harness machine are all in the take-up part, the speed change mechanism is installed in the rotating basket and the position is limited, which determines that the wire harness machine can only be made into a twisted, smaller-sized product. The number of single lines made can be flexibly configured as needed.
The quality of the stranded or bundled wire, on the one hand, depends on the quality of the single-wire material and the additional material itself, on the other hand also depending on the stranding or stranding process. The type of stranding equipment used is directly related to the structure of the stranded product, the size of the cross section and the outside diameter, the number of single strands, the thickness of the single strand, and the length of the manufactured stranded product. If the strands are concentrically stranded, first consider whether the number and size of the payoffs on the stranding machine are suitable, and then consider the stranding direction, the pitch length, and whether or not to twist the strands. If it is a re-strand, the deformation of the strands must also be taken into consideration. This requires an analysis of the structure, specifications, and materials of the strands, determination of process data, and finally the selection of suitable stranding machines. If it is a bundled product, in addition to the number and size of pay-off discs, the determination of the take-up size of the wire-harveter is much more important than that of a stranding machine.
There are provisions for the pitch length and twist direction of various stranded and bundled wires. The pitch length can be calculated by multiplying the outer diameter of the stranded or bundled wire and the practical pitch ratio. In actual production, a larger pitch ratio is generally used to facilitate the increase of productivity as much as possible. Twist must be strictly enforced according to regulations, otherwise it will affect the connection of the line.
Stranding direction: The stranding direction of each layer of strands concentrically twisted is opposite. The direction of stitching is divided into right and left directions. The axis of the stranded strand is perpendicular to the front of the chest. If the single strand is inclined from the upper right to the lower left, Right is the right direction, and vice versa is the left direction. For ease of memory, the left hand or right hand can be used to lift the palm of your hand up and your thumb is apart.
The remaining four fingers are close together, and the four fingers of the close together are in the axial direction of the stranded line. If the obliqueness of the right thumb coincides with the diagonal of the single line, it is the right direction (z direction). If the obliqueness of the left thumb coincides with the oblique line of the single line, It is the left direction (S direction),
In the product standard, it is specified not only that the strands are twisted in opposite directions but also that the outermost strand is twisted. Generally, the outermost twisted strand is twisted in the right direction.
Stranding rule: The stranded core is generally made of strands of the same material and diameter, so that the strands become round, and in the case of a fixed number of strands in the center layer, according to the equation of the arithmetic difference, each The number of layers of strands is 6.28 compared to the inner layer adjacent to it, which means that for every additional layer, 6.28 strands are added, generally six integers.
Measure the twisting pitch with a paper longer than the pitch and tighten it on the strands. Use pencils or crayons to cross the strands in the axial direction to get a set of impressions. The number of impressions should be more than the number of single lines in the measurement layer. At the center of one of them, a mark is made, starting from its neighboring one. When the number is equal to the number of single lines in the measuring layer, a mark is also made at the center of the last numbered mark and the distance between the two marks is measured. It is the pitch of this strand. For the pitch measurement of a wire harness product, since the wire harness is mostly twisted together with a single diameter of a small diameter, it cannot be measured by the tape method. Therefore, the actual measurement method can be used, that is, remove a piece of wire product, cut one of the surfaces and make a mark at the cutting place, remove 10 spirals in the opposite direction of the beam line, and then use a ruler to measure and remove the 10 spiral partial twisted wires. The length, and then divide the obtained length data by 10, the pitch length of the beam line can be obtained.
In general, the smaller the pitch ratio, the better the softness; the smaller the gap between each single wire, ie, the more densely stranded; and the greater the difference between the pitch and the actual length of the single wire at one pitch, The length of the single wire used by the same length of stranded wire also becomes longer.