Robot cable

Abstract

A robot cable, comprising: a sheath layer, first core wires, an isolating bar and filling lines, wherein a surface of the isolating bar is provided with at least three grooves spaced from each other in the extension direction thereof, and the sheath layer is sleeved on and spaced apart from an outer side of the isolating bar; one first core wire is arranged spaced apart from the side of each groove close to an inner wall of the sheath layer, and a plurality of filling lines are filled between the first core wires and the inner wall of the sheath layer and between the first core wires and the isolating bar; and the first core wires and the filling lines are both arranged in the extension direction of the isolating bar. The robot cable provides a displacement space for the first core wires during bending by means of the slip effect of the filling lines, thereby reducing the internal stress during the bending of the first core wires, improving the bending stability and prolonging the service life of the first core wires.

Description

A robot cable Technical Field

[0001] The present invention relates to the technical field of cables, and in particular to a robot cable. Background Art

[0002] Robots are widely used in various fields. In order to meet the working needs of robots in different fields, the cable part usually integrates different core wires or pipeline structures. Due to the large degree of freedom of the robot joints, the cable wiring method and cable structural design have an important impact on the long-term stable operation of the cable.

[0003] To accommodate the high degrees of freedom of movement in robot joints, existing robot cable structures typically utilize highly flexible filler materials. By filling these highly flexible materials between the core wires, the cables possess excellent torsional and bending properties. However, the addition of these fillers inevitably prevents the absolute position of the core wires from changing. While the softer filler can deform under stress during bending, reducing the probability of excessive local stress on the core wire surface through deformation, the filler's deformation effect is limited to a small deformation that disperses the local stress. For the core wire itself, the bending angle remains essentially unchanged. Furthermore, since the absolute position of the core wire relative to the cable remains essentially unchanged during bending, stress along the core wire's axis can cause fatigue within the metal. This fatigue phenomenon is particularly pronounced in cables used in robots. When the fatigue limit of the core wire metal is reached, the corresponding cable breaks and fails. Furthermore, for some robot cables that require fiber optic communication, the low ductility of fiber optic material makes it even more difficult to adapt to the long-term torsion or bending of robots.

[0004] In view of this, designing a cable with a more reasonable structure, which can increase the bending radius of the core wire in the cable to a certain extent and extend the service life of the cable has become one of the technical problems that need to be solved urgently.

[0005] Summary of the Invention

[0006] In view of this, the present invention proposes a robot cable, aiming to increase the service life of the cable through structural optimization.

[0007] The technical solution of the present invention is implemented as follows: The present invention provides a robot cable, comprising: a sheath layer, a first core wire, an isolation strip and a filling wire, the surface of the isolation strip is provided with at least three mutually spaced grooves along its extension direction, the sheath layer is arranged at intervals on the outside of the isolation strip, and each groove is spaced apart on one side close to the inner wall of the sheath layer. A first core wire is arranged at intervals, and a plurality of filling wires are filled between the first core wire and the inner wall of the sheath layer and between the first core wire and the isolation strip, and the first core wire and the filling wires are both arranged along the extension direction of the isolation strip.

[0008] In some embodiments, the groove is an arc groove, the arc radius of the groove cross section is greater than the radius of the first core wire, and the arc radius of the groove cross section is smaller than the diameter of the first core wire.

[0009] In some embodiments, the spacer strip is made of polytetrafluoroethylene.

[0010] In some embodiments, the isolation strip is located between two adjacent grooves and has a first cavity defined on the inner side of one end thereof close to the inner wall of the sheath layer.

[0011] In some embodiments, a plurality of grooves are spaced apart along a circumferential array of the spacer strips.

[0012] In some embodiments, a second cavity is defined along the axis of the isolation strip.

[0013] In some embodiments, a second core wire is further included. The second core wire is disposed in the second cavity along the extension direction of the isolation strip, and the second core wire is spaced apart from the inner wall of the second cavity.

[0014] In some embodiments, the filler wire is made of polytetrafluoroethylene.

[0015] In some embodiments, the fill line has a circular cross-section.

[0016] In some embodiments, a sliding layer is further included. The sliding layer is coaxially sleeved on the inner wall surface of the sheath layer, and the sliding layer is sleeved on the outer side of the isolation strip at intervals. The sliding layer is made of polytetrafluoroethylene.

[0017] The robot cable of the present invention has the following advantages over the prior art:

[0018] The robot cable of the present invention uses isolation strips to separate different first core wires, and at the same time, filling wires are set on the inner side of the sheath layer and the space outside the first core wire and the isolation strip for filling. Compared with the conventional setting of solidified fillers or soft fixed fillers, the filling body structure composed of multiple filling wires can undergo local position slip under the action of external stress. The local slip can provide displacement space for the first core wire, thereby avoiding the bending radius of the bent part of the first core wire being too small, reducing fatigue damage to the first core wire, and at the same time, due to the local slip of the bent part of the first core wire, the stress fatigue of the first core wire along the axial direction is greatly alleviated, thereby improving the service life of the first core wire. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] FIG1 is a cross-sectional view of a robot cable according to the present invention;

[0021] FIG2 is an isometric cross-sectional view of the robot cable of the present invention.

[0022] In the figure: 1-sheath layer, 2-first core wire, 3-isolation strip, 4-filling wire, 5-second core wire, 6-sliding layer, 31-groove, 32-first cavity, 33-second cavity. DETAILED DESCRIPTION

[0023] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0024] It should be noted that when an element is referred to as being “fixed on” or “disposed on” another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or indirectly connected to the other element.

[0025] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0026] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which embodiments of the present invention belong. If the definitions set forth in this section are contrary to or otherwise inconsistent with definitions set forth in the patents, patent applications, published patent applications, and other publications incorporated herein by reference, the definitions listed in this section take precedence over the definitions incorporated herein by reference.

[0028] As shown in Figure 1 and combined with Figure 2, one example of the robot cable of the present invention is described, which includes a sheath layer 1, a first core wire 2, an isolation strip 3 and a filling wire 4. The sheath layer 1 is a cylindrical body, the isolation strip 3 is a tensile body structure, and the side of the isolation strip 3 is provided with three grooves 31 along the axial direction. The sheath layer 1 is sleeved on the outside of the isolation strip 3, and on the inner side of the sheath layer 1, a first core wire 2 is provided on one side of each groove 31 close to the sheath layer 1. The extension direction of the first core wire 2 is the same as the extension direction of the isolation strip 3. Several filling wires 4 are arranged side by side and filled on the outside of the first core wire 2. The filling wire 4 is filled between the isolation strip 3 and the sheath layer 1, and the length direction of the filling wire 4 is the same as the extension direction of the isolation strip 3.

[0029] In conventional robotic cable solutions, a filler that cannot be compressed or flowed is placed between the core wire and the sheath. Therefore, when the cable bends, the material on the side of the cable near the outer circumference of the bent portion will be stretched, and the material on the side of the cable near the inner circumference of the bent portion will be compressed. The sheath layer 1 and the insulating layer on the surface of the core wire are usually made of polymer materials. These materials have a certain degree of elasticity. Therefore, under such low and medium frequency stretching or compression, the structural stability of the material can be maintained. However, for the filler part and the conductive part within the core wire, such forces will cause internal defects. For example, repeated stretching, compression, and bending of metals will cause internal fatigue of the metal. When the fatigue limit is reached, the conductor will break. For optical fibers made of materials such as glass fiber and fillers made of inorganic materials, low-frequency stretching and compression can cause defects, affecting functional use and structural strength.

[0030] In the above embodiment, when the cable bends, the tensile stress within the outer sheath layer 1 forces the filling wire 4 located between the outer sheath layer 1 and the adjacent first core 2 to be compressed toward the bend. At this point, the outer filling wire 4 is squeezed inward by the pressure, while the inner filling wire 4 exerts pressure on the separator strip 3 and the first core 2. Simultaneously, the outer sheath layer 1 tends to sag toward the bend due to the internal tensile stress. Due to the pressure and the deformation of the sheath layer 1, the filling wire 4 moves perpendicular to the plane of the cable after bending. This displacement of the filling wire 4 allows the outer first core 2 to move toward the bend, thereby increasing the bending radius of the outer first core 2 and reducing the internal tensile stress. Similarly, the inner first core 2 tends to move toward the outside of the bend, reducing the internal compressive stress. The isolation and filling effect of the separator strip 3 stabilizes the relative position of the filling wire 4 within the sheath layer 1. When the cable returns to its original position, the relative positions of the filling wire 4 and the corresponding first core 2 are more easily restored. The above solution provides filling lines 4 that can partially slide relative to each other, so that the first core wire 2 can adaptively adjust its position during cable bending to eliminate internal tensile stress or compressive stress, thereby providing good protection for the first core wire 2 and helping to extend its service life.

[0031] In the above embodiment, a first core wire 2 is correspondingly arranged in each of the three grooves 31. The three first core wires 2 can be core wires with different functions or core wires with the same function. Each first core wire 2 can be one of the core wires such as power line, signal line, data line, and structural line.

[0032] In the above embodiment, the sizes of different first core wires 2 may be different.

[0033] According to different usage scenarios of the robot, the first core wires 2 may be core wires with different functions, and therefore, the sizes of different first core wires 2 may be different.

[0034] In the above embodiment, the first core wire 2 includes an inner wire and at least one insulating layer coated on the outer side of the wire.

[0035] In the above embodiment, the cross-sectional dimension of the filling wire 4 is much smaller than that of the first core wire 2 . In some examples, the maximum diameter of the first core wire 2 is 5-20 mm, and the maximum diameter of the filling wire 4 is 0.1 mm-1 mm.

[0036] In some embodiments, the groove 31 is an arc groove, and the arc radius of the cross section of the groove 31 is greater than the radius of the first core 2 , and the arc radius of the cross section of the groove 31 is smaller than the diameter of the first core 2 .

[0037] In the above embodiment, the arc of the cross section of the groove 31 does not exceed 270°.

[0038] In some embodiments, the isolation strip 3 is made of polytetrafluoroethylene.

[0039] In the above embodiment, the function of the isolation strip 3 is mainly to maintain the absolute position of the first core wire 2. At the same time, the isolation strip 3 can also improve the protection of the first core wire 2 through a certain degree of self-displacement or deformation during the bending of the cable. The use of polytetrafluoroethylene material, on the one hand, has a certain degree of softness and mechanical strength, and can be adaptively deformed during the bending process of the cable. At the same time, it has good insulation and chemical stability, which meets the requirements of cable use. On the other hand, polytetrafluoroethylene has good self-lubrication. During the bending process of the cable, it has a good sliding effect with the adjacent filling wire 4, which is conducive to the sliding of the filling wire 4 and the rapid recovery of the cable shape.

[0040] In some embodiments, the isolation strip 3 is located between two adjacent grooves 31 and has a first cavity 32 defined on the inner side of one end thereof close to the inner wall of the jacket layer 1 .

[0041] In the above embodiment, in order for the first core wire 2 to have a good internal stress elimination effect during the bending process of the cable, it is necessary to provide sufficient space for the relative position change of the first core wire 2, which is achieved on the one hand by the position slip between the filling wire 4 and the first core wire 2. Since the filling wire 4 itself is a continuous linear structure, local slippage will cause stretching to itself, so its own elastic tensile deformation and tensile strength will limit the slippage. In order to make up for the insufficient slip position, a first cavity 32 is provided on the inner side of the outer peripheral body of the isolation strip 3, and the first cavity 32 is compressed under pressure to provide further slip space. At the same time, when the isolation strip 3 is made of polytetrafluoroethylene, it itself also has a certain elasticity, and the first cavity 32 can rebound when the cable is bent and reset, thereby continuing to maintain good filling and structural stability on the inside of the cable.

[0042] In the above embodiment, the first cavity 32 is provided through the extending direction of the isolation bar 3 .

[0043] Since the filling line 4 is arranged along the extension direction of the isolation strip 3, the first cavity 32 also needs to be arranged through along the extension direction of the isolation strip 3. Secondly, the continuously penetrating isolation strip can make local deformation easier to recover.

[0044] In the above embodiment, as a preferred example, the wall thickness of the first cavity 32 is the same at all locations.

[0045] As a preferred structural example, the wall thickness of the first cavity 32 is the same at all locations, so that the deformation degree of the first cavity 32 remains consistent when subjected to the same pressure. On the one hand, this is beneficial for the first cavity 32 to be able to recover to its original shape as much as possible when it rebounds after compression, and on the other hand, it can avoid stress concentration and damage.

[0046] It should be understood that the wall thickness of the above-mentioned first cavity 32 refers to the wall thickness of the first cavity 32 away from the main part of the isolation strip 3. Since the first cavity 32 is opened on the outer peripheral side of the isolation strip 3, the wall thickness of the end close to the inner peripheral side as the connecting part connected to the isolation strip 3 is not within the above-mentioned restricted range.

[0047] In some embodiments, the cross-section of the isolation bar 3 is circular, and the plurality of grooves 31 are arranged in an array along the circumference of the isolation bar 3 at intervals.

[0048] In some embodiments, a second cavity 33 is defined along the axis of the isolation strip 3 .

[0049] In the above embodiment, the second cavity 33 can further improve the deformation capability of the isolation strip 3 .

[0050] In the above embodiment, as a preferred example, the wall thickness of the second cavity 33 is the same at all locations.

[0051] Similarly, it should be understood that the wall thickness of the second cavity 33 mentioned above refers to the wall thickness of the second cavity 33 close to the groove 31. The second cavity 33 has a connecting portion close to the first cavity 32, and the wall thickness of this portion is not within the above-mentioned limited range.

[0052] In some embodiments, a second core wire 5 is further included, and the second core wire 5 is disposed in the second cavity 33 along the extending direction of the isolation strip 3. The second core wire 5 is spaced apart from the inner wall of the second cavity 33.

[0053] In the above embodiment, the second core wire 5 serves as a structural core wire, and may also serve as a core wire with a specific function, such as an optical fiber.

[0054] In the above embodiment, compared with the problem of poor bending effect of optical fiber lines in conventional cables, the second cavity 33 is located in the central part of the isolation strip 3. At the same time, as a better structural example, the isolation strip 3 is located in the central part of the sheath layer 1. Therefore, when the cable is bent, even if the second core wire 2 located in the second cavity 33 is bent, the stress generated inside it is minimized. Moreover, when the cross-sectional area of ​​the second cavity 33 is much larger than the cross-sectional area of ​​the second core wire 5, the length of the second core wire 5 in the second cavity 33 is allowed to be greater than the length of the second cavity 33. At this time, even if there is local internal stress, the internal stress can be offset by displacement in the length direction. This design has a good protective effect on the second core wire 5.

[0055] In some embodiments, the filling wire 4 is made of polytetrafluoroethylene.

[0056] In the above embodiment, considering the sliding requirements of the filling line 4 , the use of polytetrafluoroethylene material can greatly reduce the sliding difficulty of the filling line 4 .

[0057] In some embodiments, the cross-section of the filling line 4 is circular.

[0058] The above embodiment is a preferred example. The contact area between the circular filling wire 4 and the adjacent filling wires 4 as well as the first core wire 2, the sheath layer 1 and the isolation strip 3 is small, and the sliding friction is low.

[0059] In some embodiments, a sliding layer 6 is further included. The sliding layer 6 is coaxially arranged on the inner surface of the sheath layer 1 and is sleeved on the outer side of the isolation strip 3 at intervals. The sliding layer 6 is made of polytetrafluoroethylene.

[0060] The sheath layer 1 usually serves as an armor structure, and the friction between it and the filling wire 4 is not conducive to the structural stability of the filling wire 4. Therefore, a sliding layer 6 made of polytetrafluoroethylene is provided for direct contact with the filling wire 4. On the one hand, the sliding friction is reduced. On the other hand, the polytetrafluoroethylene material has good sealing and strong flexibility, which can meet the sealing and deformation requirements when the cable is bent.

[0061] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A robot cable, characterized in that: include: A sheath layer, a first core wire, an isolation strip and a filling wire. The surface of the isolation strip is provided with at least three mutually spaced grooves along its extension direction. The sheath layer is spaced on the outside of the isolation strip. A first core wire is spaced on one side of each groove close to the inner wall of the sheath layer. Several filling wires are filled between the first core wire and the inner wall of the sheath layer and between the first core wire and the isolation strip. The first core wire and the filling wires are both arranged along the extension direction of the isolation strip.

2. The robot cable according to claim 1, characterized in that: The groove is an arc groove, the arc radius of the groove cross section is greater than the radius of the first core wire, and the arc radius of the groove cross section is smaller than the diameter of the first core wire.

3. The robot cable according to claim 1, characterized in that: The isolation strip is made of polytetrafluoroethylene.

4. The robot cable according to claim 3, characterized in that: The isolation strip is located between two adjacent grooves and has a first cavity formed on the inner side of one end thereof close to the inner wall of the sheath layer.

5. The robot cable according to claim 3, characterized in that: A plurality of grooves are spaced apart along a circumferential array of the spacer strip.

6. The robot cable according to claim 5, characterized in that A second cavity is provided in the axial direction of the isolation strip.

7. The robot cable according to claim 6, characterized in that It also includes a second core wire, which is arranged in the second cavity along the extension direction of the isolation strip, and the second core wire is spaced apart from the inner wall of the second cavity.

8. The robot cable according to claim 1, wherein: The filling wire is made of polytetrafluoroethylene.

9. The robot cable according to claim 1, characterized in that: The cross section of the filling line is circular.

10. The robot cable according to claim 1, wherein: It also includes a sliding layer, which is coaxially sleeved on the inner wall surface of the sheath layer, and is sleeved on the outer side of the isolation strip at intervals, and the sliding layer is made of polytetrafluoroethylene.

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