Cable unit and method for manufacturing same

Abstract

Provided is a cable unit capable of preventing damage between a cable subject to tensile force and bending force and a coupling body of the cable.　The cable unit 1 comprises: a bendable, flexible cable 13 subject to tensile force; a coupling body 11 having a wall part 19 that covers at least a portion of the outer surface of the cable 13 in a radial direction around the cable 13; and a welding part 15 extending from the outer surface of the wall part 19 of the coupling body 11 to the cable 13 in the radial direction.

Description

Cable unit and manufacturing method thereof

[0001] The present invention relates to a cable unit for use in a robot, a manipulator, or the like, and a method for manufacturing the same.

[0002] A conventional cable unit is, for example, one that is applied to a medical manipulator, as described in Patent Document 1.

[0003] In this medical manipulator, an end effector is supported at the tip of a tiltable shaft, and a pull wire is connected to this end effector via an end collar.

[0004] The end collar is a connecting member that is connected to the tip of the pull wire, and together with the pull wire, forms a cable unit. The end collar and the pull wire can be connected by general welding at the boundary between them.

[0005] In such a medical manipulator, the end effector can be operated in a predetermined direction by tilting the tip of the shaft and pushing and pulling the pull wire.

[0006] However, in such a cable unit, tensile and bending forces act on the pull wire, which causes a problem in that the pull wire is easily damaged at the welded portion between the pull wire and the end collar.

[0007] This problem is not limited to pull wires, but is common to all cables that are subject to tensile and bending forces during operation.

[0008] Special Publication No. 2013-215509

[0009] The problem to be solved is that the cable and the connecting member are easily damaged due to the application of tensile and bending forces.

[0010] The present invention provides a cable unit comprising: a cable that is bendable and flexible and that is subject to tensile force; a connecting body having a wall portion that covers at least a portion of the outer surface of the cable in a radial direction centered on the cable; and a weld portion that extends from the outer surface of the wall portion of the connecting body to the cable in the radial direction.

[0011] The present invention also provides a method for manufacturing a cable unit, which includes covering at least a portion of the outer surface of a cable that is flexible enough to be bent and on which tensile force acts with a wall of a connecting body in a radial direction centered on the cable, and forming a weld in the radial direction from the outer surface of the wall of the connecting body to the cable by welding from the outer surface of the wall of the connecting body.

[0012] The present invention can make it difficult for damage to occur between the cable and its joint when tensile and bending forces act on the cable.

[0013] Fig. 1 is a perspective view of a jaw assembly to which a cable unit according to an embodiment of the present invention is applied in an open state. Fig. 2 is a perspective view of the jaw assembly of Fig. 1 in a closed state. Fig. 3 is an enlarged schematic perspective view showing a portion of a cable unit used in the jaw assembly of Fig. 1. Fig. 4 is a schematic side view showing a portion of the cable unit of Fig. 3. Fig. 5 is a schematic cross-sectional view showing a portion of the cable unit of Fig. 4. Fig. 6 is a schematic cross-sectional view showing a portion of a cable unit according to a comparative example.

[0014] The objective of making it difficult for the cable and its connector to be damaged when tensile and bending forces act on them is achieved by welding the cable to the connector from the outer surface of the wall of the connector to the cable.

[0015] The cable unit 1 includes a cable 13, a connecting body 11, and a weld 15. The cable 13 is a long, flexible member that can be bent and to which a tensile force acts. The connecting body 11 has a wall 19 that covers at least a portion of the outer surface of the cable 13 in a radial direction from the cable 13. The weld 15 is formed in the radial direction from the outer surface of the wall 19 of the connecting body 11 to the cable 13. It is preferable that the weld 15 be located only within the range of the outer surface of the wall 19.

[0016] The shape of the wall 19 of the connecting body 11 can be set as appropriate, but in one embodiment, it may be cylindrical. In this case, the cable 13 has a tip located inside the wall 19 of the connecting body 11, and the weld 15 may be formed along the cable 13 in the extension direction of the cable 13 from a portion corresponding to the tip of the cable 13.

[0017] The shape of the welded portion 15 can also be set as appropriate, but in one embodiment, a plurality of welded portions 15 may be arranged at intervals in the circumferential direction of the wall portion 19 of the combined body 11. Alternatively, the welded portion 15 may be formed by a series of a plurality of weld spots 15a.

[0018] The shape of the cable 13 can be set as appropriate, but in one embodiment, the cable 13 may be a twisted wire made up of a central member 13a and a peripheral member 13b arranged in a spiral shape around the central member 13a.

[0019] In the manufacturing method of the cable unit 1, at least a part of the outer surface of the cable 13, which has flexibility to be bent and to which a tensile force acts, is radially covered with the wall portion 19 of the connecting body 11. Then, welding is performed from the outer surface of the wall portion 19 of the connecting body 11, thereby forming the welded portion 15 that extends from the outer surface of the wall portion 19 to the cable 13 in the radial direction.

[0020] The welding can be performed by any suitable method, but may be performed by laser welding.

[0021] [Jaw Assembly] Fig. 1 is a perspective view of a jaw assembly to which a cable unit according to an embodiment of the present invention is applied, in an open state. Fig. 2 is a perspective view of the jaw assembly of Fig. 1, in a closed state. Fig. 3 is an enlarged schematic perspective view showing a part of the cable unit used in the jaw assembly of Fig. 1.

[0022] 1 to 3 is applied to robots, manipulators, and other devices in various fields such as medicine and industry. In this embodiment, the cable unit 1 is incorporated into a jaw assembly 3, which is a forceps used in a surgical support robot, a surgical support manipulator, or the like.

[0023] The jaw assembly 3 is supported on a shaft (not shown) via a bending portion 4. The bending of the bending portion 4 allows the jaw assembly 3 to be oriented in an appropriate direction.

[0024] In the jaw assembly 3 of this embodiment, a pair of jaws 5 and 7 are rotatably supported by a support portion 9. This support allows the pair of jaws 5 and 7 to open and close relative to each other, and they open and close between the open state shown in Fig. 1 and the closed state shown in Fig. 2. The opening and closing movements of the jaws 5 and 7 are performed by pushing and pulling the cable unit 1.

[0025] [Cable Unit] Fig. 4 is a schematic side view showing a part of the cable unit 1 of Fig. 3. Fig. 5 is a schematic cross-sectional view showing a part of the cable unit 1 of Fig. 4.

[0026] The cable unit 1 includes a connector 11 , a cable 13 , and a weld 15 .

[0027] The cable 13 is a flexible, long member, and in this embodiment is a push-pull cable that is operated so as to push and pull in the extension direction relative to the jaw assembly 3. A tensile force acts on the cable 13 when it is pulled relative to the jaw assembly 3, and the cable 13 bends when the bending portion 4 bends.

[0028] The cable 13 is not limited to a push-pull cable, but may be any cable that is flexible enough to be bent and to which a tensile force is applied. For example, the cable of the cable unit may be an operating wire for bending the bending portion 4.

[0029] The cable 13 may be any suitable long member such as a twisted wire, a single wire, an articulated rod, a chain, a string, a thread, a rope, etc. In this embodiment, the cable 13 is made of a twisted wire.

[0030] 4, the cable 13 is made up of a central member 13a and a peripheral member 13b spirally arranged around the central member 13a. A plurality of peripheral members 13b, for example, seven, are provided. The material of the cable 13 can also be selected as appropriate, but in this embodiment, stainless steel is used.

[0031] The coupling body 11 is a member coupled to the cable 13. The coupling body 11 has a wall portion 19 that radially covers at least a portion of the outer surface of the cable 13. The radial direction refers to the radial direction of the cable 13 with the cable 13 at the center.

[0032] The shape of the connecting body 11 can be set as appropriate depending on the type of cable 13, etc., but in this embodiment it has a wall portion 19 and a head portion 17. The material of the connecting body 11 can also be set as appropriate, but in this embodiment it is made of the same stainless steel as the cable 13. It is preferable that the wall portion 19 of the connecting body 11 be made of a material that is compatible with the cable 13 for welding.

[0033] The head portion 17 is formed in a rectangular plate shape and has a pair of elongated holes 17a. Although not shown, a pair of jaws 5 and 7 engage with the pair of elongated holes 17a, and the jaws 5 and 7 are linked to the operation of the head portion 17. This linkage causes the jaws 5 and 7 to open and close.

[0034] The wall portion 19 is configured in a cylindrical shape with an open base end. The base end refers to the end farthest from the jaws 5 and 7, assuming that the end closest to the jaws 5 and 7 in the extension direction of the cable unit 1 is the tip end. The tip end and base end are the same for each part of the cable unit 1.

[0035] The wall 19 may be any wall that covers at least a portion of the outer surface of the cable 13 in the radial direction, and may be a structure in which simple wall portions are arranged in a circumferential shape with slits between the wall portions, or a structure in which one or more simple wall portions are provided. The thickness of the wall portion 19 in the radial direction is constant, but may be set as appropriate, for example, to vary.

[0036] The welded portion 15 is formed in the radial direction from the outer surface of the wall portion 19 of the connecting body 11 to the cable 13. In this way, the welded portion 15 fixes the wall portion 19 of the connecting body 11 and the cable 13 together.

[0037] In this embodiment, a plurality of welds 15 are spaced apart in the circumferential direction. For example, the welds 15 are formed at four circumferential locations, each at an angle of 90 degrees. Each weld 15 is formed along the cable 13 in the extension direction of the cable 13, from a portion corresponding to the tip of the cable 13. Although a gap exists between the base end of the weld 15 and the base end of the wall portion 19 in the extension direction, this gap does not have to be present. In this way, the welds 15 are located only within the range of the outer surface of the wall portion 19. In other words, the welds 15 are located only within the range of overlap between the wall portion 19 and the cable 13 in the radial direction.

[0038] Each weld 15 has a plurality of weld spots 15 a formed in succession. The number of weld spots 15 a is arbitrary, but in this embodiment, the number is four. Note that the weld 15 may be formed in a ring shape along the circumferential direction, and a plurality of weld spots 15 may be provided in the extension direction of the wall portion 19.

[0039] The penetration of such welded portion 15 into cable 13 in the radial direction is shallower than when a welding spot is formed directly on cable 13. Therefore, the area of ​​cable 13 that is softened by welding can be reduced.

[0040] FIG. 6 is a schematic cross-sectional view showing a part of a cable unit according to a comparative example.

[0041] The welded portion 15A of the comparative example is composed of a single weld spot 15Aa, and is formed at the boundary between the base end of the wall portion 19 and the cable 13. This welded portion 15A is formed at four locations in the circumferential direction. The configuration other than the welded portion 15Aa is the same between the comparative example and the example.

[0042] In the welded portion 15 of this comparative example, the penetration into the cable 13 in the radial direction is greater than in the embodiment of FIG.

[0043] The cable unit 1 of this example had a tensile load of 27 to 50 N until it broke, whereas the comparative example had a load of 25 N. Furthermore, the number of times the cable unit 1 could be bent at the bending portion 4 before it was damaged was about 100 to 200 times in the comparative example, whereas the present example was able to achieve 3,600 times or more, which was 18 to 36 times higher.

[0044] In this way, the cable unit 1 of this embodiment can be made less susceptible to damage between the cable 13 and the connecting body 11, where tensile and bending forces act.

[0045] [Method of Manufacturing Cable Unit] When manufacturing the cable unit 1, at least a portion of the outer surface of the cable 13 is radially covered with the wall portion 19 of the connecting body 11, as shown in Fig. 5. In this embodiment, the tip of the cable 13 is inserted into the wall portion 19. As a result, the outer surface of the tip portion of the cable 13 is covered with the tubular portion 19.

[0046] Next, welding is performed from the outer surface of the wall portion 19 of the combined body 11, thereby forming welds 15 extending radially from the outer surface of the wall portion 19 to the cable 13. In this embodiment, the welds 15 are formed at a plurality of locations (four locations) in the circumferential direction of the wall portion 19. The welding is performed by, for example, laser welding, so that the weld spots 15a overlap each other.

[0047] In this way, in this embodiment, the cable unit 1 in which the connector 11 is connected to the cable 13 can be manufactured simply by inserting the tip of the cable 13 into the wall portion 19 and welding from the outer surface of the wall portion 19. At the same time, the manufactured cable unit 1 can be made less susceptible to damage.

[0048] As described above, in this embodiment, by forming a welded portion 15 extending from the outer surface of the wall portion 19 of the connecting body 11, which radially covers at least a portion of the outer surface of the cable 13, to the cable 13, the cable unit 1 can be made less susceptible to damage between the cable 13 and the connecting body 11.

[0049] Furthermore, the cable 13 has a tip located within the wall portion 19 of the connecting body 11, and the welded portion 15 is formed along the cable 13 in the extension direction from a portion corresponding to the tip of the cable 13.

[0050] This makes it possible to more reliably prevent the cable unit 1 from being damaged.

[0051] Furthermore, by arranging multiple welds 15 at intervals around the circumference of the wall portion 19 of the connecting body 11, it is possible to position portions of the cable 13 that have not been softened by welding around the circumference, making it more reliable to prevent damage to the cable unit 1.

[0052] The cable 13 is a stranded wire made up of a central member 13a and a surrounding member 13b. The welded portion 15 does not extend radially into the cable 13 to a large extent, and therefore does not reach the central member 13a of the cable 13. This makes it possible to more reliably prevent damage to the cable unit 1.

[0053] The welded portion 15 has a plurality of weld spots 15a formed in succession, which can more reliably prevent the cable unit 1 from being damaged.

[0054] REFERENCE SIGNS LIST 1 cable unit 3 jaw assembly 4 bending portion 5, 7 jaw 9 support portion 11 coupling body 13 cable 13a central member 13b peripheral member 15, 15A welded portion 15a, 15Aa weld spot 17 head portion 17a elongated hole 19 wall portion

Claims

1. A cable unit comprising: a bendable, flexible cable that is subject to tensile force; a connecting body having a wall portion that covers at least a portion of the outer surface of the cable in a radial direction from the cable center; and a welded portion that extends from the outer surface of the wall portion of the connecting body to the cable in the radial direction.

2. A cable unit according to claim 1, wherein the wall of the combined body is tubular, the cable has a tip located within the wall of the combined body, and the weld is formed along the cable in the extension direction of the cable from a portion of the cable corresponding to the tip.

3. A cable unit according to claim 1 or 2, wherein a plurality of said welds are arranged at intervals in the circumferential direction relative to said wall portion of said coupling body.

4. A cable unit according to claim 1 or 2, wherein the cable is a stranded wire consisting of a core member and a peripheral member arranged in a spiral shape around the core member.

5. A cable unit according to claim 1 or 2, wherein the welded portion is formed by a plurality of weld spots formed in succession.

6. A cable unit according to claim 1 or 2, wherein the welds are located only within the outer surface of the wall portion.

7. A method for manufacturing a cable unit, comprising covering at least a portion of the outer surface of a flexible cable that is bendable and subject to tensile force with a wall of a connecting body in a radial direction from the cable center, and performing welding from the outer surface of the wall of the connecting body to form a weld from the outer surface of the wall to the cable in the radial direction.

8. A method for manufacturing a cable unit according to claim 7, wherein the welding is laser welding.

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