CN104051073B - Shielded data cables for manipulators - Google Patents

Abstract

The invention discloses a shielding type data cable for a mechanical arm, which comprises eight copper conductor units; the eight copper conductor units are twisted pairwise to form four symmetrical insulated wire pairs, and the outer surfaces of the four symmetrical insulated wire pairs are wrapped with first polytetrafluoroethylene tapes and are twisted to form cable cores; the second polytetrafluoroethylene layer longitudinally wraps the outer surface of the cable core, and a plurality of cotton yarns are filled in gaps between the second polytetrafluoroethylene layer and the four symmetrical insulating line pairs; a cotton fiber wire is wound on the outer surface of the second polytetrafluoroethylene layer to form a buffer sliding layer, the winding direction of the cotton fiber wire is opposite to the twisting direction of the four symmetrical insulated wires, a plurality of metal wires are wound on the outer surface of the buffer sliding layer side by side to form a metal shielding layer, and the winding direction of the metal wires in the metal shielding layer is opposite to that of the cotton fiber wire; and a third polytetrafluoroethylene layer is wrapped on the outer surface of the metal shielding layer. The data cable has the advantages of small friction coefficient, flexibility, stretch resistance, no friction static generation and stable structure and electrical performance after frequent movement.

Description

Shielded data cables for manipulators

technical field

The invention relates to a data cable, in particular to a shielded data cable for a mechanical arm.

Background technique

The structure of the traditional shielded data cable is composed of 4 sets of symmetrical signal wire pairs, wrapped with a layer of polyester tape, and then wrapped with a layer of aluminum-plastic composite tape for shielding, and the outer layer is extruded with PVC or other plastic coatings. . Symmetrical signal pairs are formed by the assembly of two copper conductors with an insulated wire covered by a layer of high-density polyethylene. Product performance conforms to the specification requirements of TIA/EIA568. In order to solve the problem of electrical performance attenuation and electromagnetic interference at lower frequencies, some products are designed to braid a layer of copper wire shielding on the outer layer of the aluminum-plastic composite tape. For shielded data cables that require movement, the conductors of the symmetrical signal pairs are replaced with multiple copper stranded conductors. The data cable with this structure can guarantee the transmission performance when it is used in fixed laying and mobile occasions. However, for environments with frequent movements such as robotic arms and relatively harsh environmental conditions, the performance reliability of this type of product cannot meet the requirements. After hundreds of movements, problems such as conductor breakage, increased attenuation, and decreased anti-interference performance will occur. . In the process of moving, there is friction between the insulation, the insulation and the outer tape, and the shield. On the one hand, it is easy to generate static electricity and cause signal interference. At the same time, frequent friction will also cause the mechanical and physical properties of the insulation material to decline. A general mechanical arm will require more than 100,000 movements. If the influence of the sliding of the cable core structure cannot be solved, the problems of product fatigue resistance and shielding stability cannot be solved, and the signal transmission requirements of the mechanical arm cannot be guaranteed. At this point, it is difficult for the traditional cable structure to meet the requirements.

How to design a data cable that can ensure stable signal transmission during more than 100,000 frequent reciprocating movements has become the direction of efforts of those skilled in the art.

Contents of the invention

The invention provides a shielded data cable for a manipulator. The shielded data cable for a manipulator has a small friction coefficient, is soft and stretchable, has no friction and static electricity, and can still ensure a stable structure after frequent movement. The product After 100,000 times of bending, the electrical performance change rate is less than 5%.

In order to achieve the above object, the technical solution adopted by the present invention is: a shielded data cable for a manipulator, comprising: eight copper conductor units, the outer surface of the copper conductor units is covered with an insulating polypropylene layer, and the copper conductor units It is made of several copper wires twisted together;

The eight copper conductor units are twisted in pairs to form first, second, third and fourth symmetrical insulated wire pairs, and the respective outer surfaces of the first, second, third and fourth symmetrical insulated wire pairs are wound Wrapped with a first polytetrafluoroethylene tape and twisted to form a cable core;

The second polytetrafluoroethylene layer longitudinally covers the outer surface of the cable core, and the gaps between the second polytetrafluoroethylene layer and the first, second, third and fourth symmetrical insulated wire pairs are filled with several cotton yarns;

A cotton fiber thread is wound on the outer surface of the second polytetrafluoroethylene layer to form a buffer sliding layer. The winding direction of the cotton fiber thread is opposite to the twisting direction of the first, second, third and fourth symmetrical insulated wire pairs. A metal wire is wound side by side on the outer surface of the buffer sliding layer to form a metal shielding layer, and in the metal shielding layer, the metal wire is wound opposite to the cotton fiber thread;

A third polytetrafluoroethylene layer is wrapped around the outer surface of the metal shielding layer, and an outer sheath layer is wrapped around the outer surface of the third polytetrafluoroethylene layer.

Further improvement technical scheme in above-mentioned technical scheme is as follows:

In the above solution, the cotton fiber thread is sparsely wound on the outer surface of the second polytetrafluoroethylene layer.

Due to the use of the above-mentioned technical solutions, the present invention has the following advantages compared with the prior art:

1. In the shielded data cable for the mechanical arm of the present invention, the first, second, third and fourth symmetrical insulated wire pairs are respectively wrapped with a first polytetrafluoroethylene tape and twisted to form a cable core. Two polytetrafluoroethylene layers longitudinally wrap the outer surface of the cable core, and overcome the distance and pitch between the first, second, third and fourth symmetrical insulated wires and their respective copper conductor units during frequent bending Changes occur, thereby causing changes in electrical performance; and during frequent bending, the first, second, third and fourth symmetrical insulated wire pairs are wrapped with the first polytetrafluoroethylene tape on their respective outer surfaces, and the second The polytetrafluoroethylene layer wraps the symmetrical insulated wire pair with four first polytetrafluoroethylene tapes by longitudinal wrapping, because the first polytetrafluoroethylene tape and the second polytetrafluoroethylene layer have low friction coefficient and high strength , corrosion resistance, and good insulation performance. The friction coefficient of the strip is 0.04, which is the material with the lowest friction coefficient among solid materials at present, and it is covered by longitudinal wrapping in front of the metal shielding layer to reduce the overlap caused by the wrapping structure. The increase of friction force caused by contact minimizes the impact of the structural change of the cable core during frequent bending; secondly, due to the reduction of friction force and the PTFE tape is not easy to generate static electricity, it also greatly reduces the generation of static electricity and improves the reliability of performance. sex and safety.

2. The shielded data cable for the mechanical arm of the present invention, the gap between the second polytetrafluoroethylene layer and the first, second, third and fourth symmetrical insulated wire pairs is filled with several cotton yarns, a cotton fiber The wire is wound on the outer surface of the second polytetrafluoroethylene layer to form a buffer sliding layer. The winding direction of the cotton fiber wire is opposite to the twisting direction of the first, second, third and fourth symmetrical insulated wire pairs. Several metal wires Wrapped on the outer surface of the buffer sliding layer to form a metal shielding layer, the metal wires in the metal shielding layer are wound side by side opposite to the cotton fiber thread, so as to ensure that the metal wire has enough moving position when bending without stretching and causing breakage. At the same time, it is easier to slide between the copper wire and the insulating sliding layer without electrostatic interference. This structure can not only ensure the softness of the cable, but also ensure the shielding effect after frequent bending.

3. In the shielded data cable for the mechanical arm of the present invention, a second polytetrafluoroethylene layer is sequentially arranged between the cable core and the outer sheath layer, and a cotton fiber thread is wound on the outer surface of the second polytetrafluoroethylene layer A buffer sliding layer is formed, several metal wires are wound side by side around the buffer sliding layer to form a metal shielding layer, a third polytetrafluoroethylene layer is wrapped around the outer surface of the metal shielding layer, between the metal shielding layer and the outer sheath Form a buffer to avoid electrostatic interference between the outer sheath and the shielding layer during the reciprocating movement of the cable; at the same time, the performance of the PTFE tape is relatively soft and smooth, which will not affect the softness of the cable. The smooth surface makes it easy to slip between the cable core and the sheath during the bending process, which reduces the stretching of the copper conductor and the tinned copper wire braid by external forces and prolongs the service life.

Description of drawings

Accompanying drawing 1 is the structural representation of the shielded data cable of manipulator of the present invention;

Accompanying drawing 2 is the structure schematic diagram of buffer sliding layer and metal shielding layer of the present invention;

Accompanying drawing 3 is A-A sectional structure schematic diagram in accompanying drawing 2;

Accompanying drawing 4 is the structural schematic diagram of comparative example.

In the above drawings: 1. Copper conductor unit; 11. Copper wire; 2. Insulated polypropylene layer; 3. The first symmetrical insulated pair; 4. The second symmetrical insulated pair; 5. The third symmetrical insulated pair; 6. The fourth symmetrical insulated wire pair; 7. The first polytetrafluoroethylene tape; 8. Cable core; 9. The second polytetrafluoroethylene layer; 10. Cotton yarn; 12. Buffer sliding layer; 13. Metal wire; 14 1. Metal shielding layer; 15. The third polytetrafluoroethylene layer; 16. Outer sheath layer; 17. Cotton fiber thread; 18. Polyester tape; 19. Metal braiding layer.

detailed description

The present invention will be further described below in conjunction with accompanying drawing and embodiment:

Embodiment: A shielded data cable for a manipulator, comprising: eight copper conductor units 1, the copper conductor unit 1 is covered with an insulating polypropylene layer 2, and the copper conductor unit 1 is composed of several copper wires 11 stranded;

The eight copper conductor units 1 are twisted in pairs to form first, second, third and fourth symmetrical insulated wire pairs 3, 4, 5, 6, and the first, second, third and fourth symmetrical The outer surfaces of the insulated wire pairs 3, 4, 5, and 6 are wrapped with a first polytetrafluoroethylene tape 7 and twisted to form a cable core 8;

The second polytetrafluoroethylene layer 9 longitudinally wraps the outer surface of the cable core 8, and the second polytetrafluoroethylene layer 9 is connected to the first, second, third and fourth symmetrical insulated wire pairs 3, 4, 5, The gap between 6 is filled with several cotton yarns 10;

In the frequent bending process, the distance and pitch between the first, second, third and fourth symmetrical insulated wires and the respective copper conductor units are changed, thereby causing changes in electrical performance; and the frequent bending process Among them, the outer surfaces of the first, second, third and fourth symmetrical insulated wire pairs are wrapped with a first polytetrafluoroethylene tape, and the second polytetrafluoroethylene layer is wrapped with four fourth A symmetrical insulated pair of polytetrafluoroethylene tapes, because the first polytetrafluoroethylene tape and the second polytetrafluoroethylene layer have low friction coefficient, high strength, corrosion resistance, and good insulation performance, the friction coefficient of the tape is 0.04, which is the material with the lowest friction coefficient among solid materials at present, and it is covered by longitudinal wrapping in front of the metal shielding layer to reduce the increase of friction caused by the lap joint caused by the wrapping structure, so that the cable core will The impact of structural changes is minimized; secondly, due to the reduction of friction and the PTFE belt is not easy to generate static electricity, it also greatly reduces the generation of static electricity, improving performance reliability and safety;

A cotton fiber thread 17 is wound on the outer surface of the second polytetrafluoroethylene layer 9 to form a buffer sliding layer 12, and the winding direction of the cotton fiber thread 17 is the same as that of the first, second, third and fourth symmetrical insulated wire pairs 3, 4, 5, and 6 are twisted in opposite directions, and several metal wires 13 are wound side by side on the outer surface of the buffer sliding layer 12 to form a metal shielding layer 14. In this metal shielding layer 14, the metal wires 13 are wound with the cotton fiber line 17 On the contrary; on the one hand, when bending, the copper wire has enough moving position without stretching to cause disconnection, and at the same time, it is easier to slide between the copper wire and the insulating sliding layer without generating electrostatic interference. This structure can not only ensure the softness of the cable It also ensures the shielding effect after frequent bending;

A third polytetrafluoroethylene layer 15 wraps around the outer surface of the metal shielding layer 14 , and an outer sheath layer 16 wraps around the outer surface of the third polytetrafluoroethylene layer 15 . A buffer is formed between the metal shielding layer and the outer sheath to avoid electrostatic interference between the outer sheath and the shielding layer during the reciprocating movement of the cable. At the same time, the performance of the PTFE tape is relatively soft and smooth, which will not affect the softness of the cable. Through the process control of the sheath extrusion, the smooth surface makes it easy to produce friction between the cable core and the sheath during the bending process. Sliding, reducing the stretching of copper conductor and tinned copper wire braid by external force, prolonging the service life.

The above-mentioned cotton fiber thread 17 is sparsely wound on the outer surface of the second polytetrafluoroethylene layer 9 .

Comparative example: a shielded data cable for a manipulator, including eight copper conductor units 1, the outer surface of the copper conductor unit 1 is covered with an insulating polypropylene layer 2, and the copper conductor unit 1 is twisted by several copper wires 11 combined;

The eight copper conductor units 1 are twisted in pairs to form first, second, third and fourth symmetrical insulated wire pairs 3, 4, 5, 6, and the first, second, third and fourth symmetrical Insulated wire pairs 3, 4, 5, 6 are twisted to form a cable core 8, and a polyester tape 18 is wrapped around the outer surface of the cable core 8, and the polyester tape 18 is connected to the first, second, third and fourth The gaps between the symmetrical insulated wire pairs 3, 4, 5, and 6 are filled with several cotton yarns 10;

A metal braiding layer 19 woven by several copper wires is located on the outer surface of the polyester belt 18 , and an outer sheath layer 16 is wrapped on the outer surface of the metal braiding layer 19 .

The performance test data are shown in Table 1:

Table 1

The above-mentioned embodiments are only to illustrate the technical concept and characteristics of the present invention, and the purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly, and not to limit the protection scope of the present invention. All equivalent changes or modifications made according to the spirit of the present invention shall fall within the protection scope of the present invention.

Claims (1)

1. A shielded data cable for a manipulator, characterized in that it includes: eight copper conductor units (1), the outer surface of the copper conductor unit (1) is covered with an insulating polypropylene layer (2), the copper The conductor unit (1) is formed by twisting several copper wires (11); The eight copper conductor units (1) are twisted in pairs to form first, second, third and fourth symmetrical insulated wire pairs (3, 4, 5, 6), and the first, second, third The outer surfaces of the fourth symmetrical insulated wire pair (3, 4, 5, 6) are wrapped with a first polytetrafluoroethylene tape (7) and twisted to form a cable core (8); The second polytetrafluoroethylene layer (9) longitudinally wraps the outer surface of the cable core (8), and the second polytetrafluoroethylene layer (9) is connected to the first, second, third and fourth symmetrical insulated wire pairs (3, 4, 5, 6) are filled with several cotton yarns (10); A cotton fiber thread (17) is wound on the outer surface of the second polytetrafluoroethylene layer (9) to form a buffer sliding layer (12), and the winding direction of the cotton fiber thread (17) is the same as that of the first, second, third and The twisting direction of the fourth symmetrical insulated wire pair (3, 4, 5, 6) is opposite, and several metal wires (13) are wound side by side on the outer surface of the buffer sliding layer (12) to form a metal shielding layer (14). The winding of the metal wire (13) in the metal shielding layer (14) is opposite to that of the cotton fiber thread (17); A third polytetrafluoroethylene layer (15) is wrapped around the outer surface of the metal shielding layer (14), and an outer sheath layer (16) is wrapped around the outer surface of the third polytetrafluoroethylene layer (15) .