JP5569029B2 - Cable support device for industrial robot with flexible guide - Google Patents

Description

The present invention relates to a cable support device that handles the routing of cables and hoses connected to a work tool attached to an arm tip of an industrial robot, and more particularly to a cable support device for an industrial robot using a flexible guide .

  Industrial robots are connected by power and signal cables and hoses between a work tool attached to an end effector at the tip of a robot arm and equipment installed on or around the robot arm. When a cable for the amount of movement necessary for the operation of the robot is loosened and laid around the robot arm, the behavior of the cable is not stable, and there is a problem that the cable is damaged by interference with the robot arm itself and peripheral devices.

  Therefore, as a cable support device that reduces interference with peripheral devices by maintaining a U-shaped shape that wraps the behavior of the cable around the arm, a plurality of fan shapes arranged in an arc belt-shaped member in Patent Document 1 A cable support device using a support block, a cable support device that connects a plurality of support blocks in a circular arc shape by pin connection to Patent Document 2, and a spacer that sandwiches a connecting portion between each of a plurality of support blocks that are connected to Patent Document 3 at the center. Or the cable support apparatus which provides a protrusion control part and forms circular arc shape is disclosed. Patent Document 4 discloses a cable support device that guides a cable in a U shape within a cylindrical guide. Patent Document 5 discloses a cable support device that absorbs slack in a cable by allowing a base side support portion to slide and rotate.

Japanese Utility Model Publication No. 58-184293 JP-A-62-34795 JP 2006-304559 A JP 2004-17220 A Japanese Patent Laid-Open No. 2006-150496

  However, all of the known solutions disclosed in Patent Documents 1, 2, and 3 maintain a U-shape that wraps around the arm by connecting a plurality of support blocks arranged in a circular arc shape. In either case, it is necessary to connect support blocks each having a quantity corresponding to a necessary movement amount, and there is a problem that a great number of man-hours are required for production. In addition, the large number of parts is a high cost factor.

  Further, in any of Patent Documents 1, 2, and 3, since the radius of curvature of the arc is determined by the shape of the support block arranged in the shape of an arc belt, the diameter of the arm wound when the U-shaped shape is formed is also unique. It will be decided. Since the required winding diameter varies depending on the size of the robot and the application site, there is a problem that a support block having a shape corresponding to each robot is required, and the degree of freedom for diversion and diversion is small. In addition, the support block is generally resin-molded, and the need for a plurality of types of these is also a high cost factor.

  Further, in the solution disclosed in Patent Document 4, a cylindrical guide guide is necessary to maintain a shape that wraps around the arm, and there is a problem that the apparatus is increased in size and weight.

  Further, in the solution disclosed in Patent Document 5, since the slack is absorbed in the form that the cable protrudes largely on the base side arm instead of the slack around the arm, the robot is located above and behind the robot other than the arm periphery. There is a problem that the cable interferes with peripheral devices.

An object of the present invention is to solve the problems of the related art, and to realize a cable behavior to be obtained by simple adjustment. A cable support device for an industrial robot using a low-cost, simple, small and light flexible guide. Is to provide.

In the present invention, a tubular flexible member, a fixing portion provided at both ends of the flexible member and having an opening hole that shares a through hole and an opening of the flexible member, and along the longitudinal direction of the flexible member, A set of insertion holes formed symmetrically with respect to the central axis of the cross-section of the flexible member, and two wire rods inserted into the respective insertion holes, and both ends of the wire rod are fixed to the fixing portion, By using flexible guides having different lengths between the fixed portions of the two wire rods, the above-described problems have been solved.

  The cylindrical flexible member is made of a flexible or bellows-like resin, a metal tube, or a material such as a helical spring for the exterior, and is composed of one or a plurality of combinations, and can be bent, twisted, and stretched. In the present invention, the fixing member is provided at both ends, and the wire rod that has been passed through the insertion hole that is symmetrical with respect to the central axis of the cross section is fixed to the fixing member. The Furthermore, since the lengths of the wire rods are different, a part of the donut shape having a shorter wire rod inside and a longer wire rod outside and a half donut shape are formed. If the positions in the width direction of the fixed portions at both ends are restricted, a U-shape or Ω-shape is formed. Moreover, arbitrary curvature radii can be easily obtained by adjusting the length of the wire.

  Then, for example, when the left and right fixing members are rotated inward so that the shorter wire members are on the lower side in a state where they are placed horizontally with the fixing portion side of the flexible guide facing forward, the central portion of the flexible member is Receives force to move downward. When it is lifted in this state, the central part of the flexible member is twisted toward the lower side under the influence of gravity. By utilizing this property, the fixed member is arranged along the shaft so that the shorter wire is on the shaft side and the central portion of the flexible member is directed downward due to gravity, so that the bending due to gravity can occur. And the shape which a flexible member winds around an axis | shaft with the bending force of the wire of different length can be ensured. Thereby, the shape of a flexible guide can be ensured, without restricting places other than a fixing member.

  Note that when both of the shorter wires are rotated outward so as to be on the upper side, a force is applied so that the central portion of the flexible member is twisted upward. Further, if the fixing portion is lengthened, the shape of the entire flexible guide can be adjusted to be U-shaped, and if it is shortened, the shape can be adjusted to approximate Ω-shape. Furthermore, if the fixing portion is bent in accordance with the deformation direction of the flexible member, it is easy to ensure the winding shape.

By using such a flexible guide, the cable of the industrial robot having the second arm rotatably supported by the arm support shaft provided on the first arm serving as the base is connected to the arm support axis, that is, the second arm. It can be controlled to wrap around the axis. Therefore, in the present invention, an industrial robot having a first arm serving as a base and a rod-like second arm supported rotatably with respect to an arm support shaft of the first arm. The side surface portion of the one fixed portion on the side where the length of the wire is short is such that the opening holes of the fixed portion at both ends of the flexible member are directed in the same direction around the arm support shaft. It is fixed to the first arm so as to be on the support axis side, and the side surface portion of the other fixing portion on the side where the length of the wire is short is fixed to the outer periphery of the second arm, and passes through the opening hole. A cable support device for an industrial robot having a flexible guide in which a cable connecting the first arm and the second arm is inserted into the through hole.

  As a result, even if the second arm rotates relative to the first arm around the arm support axis, the flexible guide will wrap around the arm support axis due to gravity and bending force of different lengths of wire. The U-shaped or Ω-shaped shape is secured by itself, and the cable is held by the flexible guide. Needless to say, a flexible hose (pipe) for oil or air pressure, a signal line, or the like may be inserted in the flexible guide.

In the invention according to claim 2 , the opening hole of the fixing portion on the first arm side of the flexible guide is opened downward. Thereby, gravity can be made to act efficiently on a flexible guide.

According to the present invention, the flexible member is bent at the both ends of the flexible member, and the flexible guide is bent with a simple structure in which the wire rods having different lengths that are passed through the insertion holes symmetric with respect to the central axis of the cross section are fixed to the fixed portion. Since it is possible to regulate the torsion and expansion / contraction direction, we provide a cable support device for industrial robots that uses low-cost, simple, small, and lightweight flexible guides that regulate cable behavior by simple adjustment. It became a thing.

Then, for the second arm that rotates with respect to the arm support shaft of the first arm that is the base of the industrial robot, the flexible guide has an arm support axis (first shaft) due to gravity and bending force of different lengths of wire. The outer circumference of the second arm) works to secure a U-shaped or Ω-shaped shape that wraps around itself, or can maintain a certain shape, so it can accommodate cables and hoses, and the cables and hoses can be stretched. The need to consider bending behavior has been reduced, eliminating the need for a large number of support blocks and large guide blocks. Furthermore, the cable support device can reduce the overhang of cables, and the structure around the arm of the industrial robot is simple, easy to maintain, and clean. In addition, since it can be manufactured by cutting to a required length according to the amount of cable movement to be inserted into the flexible guide, it is possible to provide a low-cost cable support device with a small number of parts and easy assembly.

In the second aspect of the present invention, since the opening hole of the fixing portion on the first arm side of the flexible guide is opened downward and gravity is effectively applied, the flexible guide is moved to the arm support axis (second The arm axis) can be surely wound around.

It is a partial section perspective view of one form of a flexible guide used for the present invention . It is an expanded sectional view which shows the XX line cross section of FIG. It is the schematic showing the state which bent the cable support apparatus in the U shape. (A), (b), (c) is an expanded sectional view which shows the part corresponded in the XX sectional drawing of FIG. 1 of the flexible guide which shows another form . (A) is a schematic top view showing an embodiment of a cable support system of the industrial robot of the present invention, (b) is a front view, (c) is a partially enlarged sectional view showing a line Y-Y cross section of (b) It shows the state at a position where the flexible guide is centerline symmetrical. The state where the flexible guide is actually mounted between the relatively rotating shafts is shown in the figure, (a) and (b) are the states in which the rotating shaft is rotated clockwise from the position (c), and (c) is the state where the flexible guide is FIG. 6 is a perspective view showing a state in a center line symmetrical position, (d) is a state rotated left from the original position state, and (e) and (f) are further rotated left.

A first embodiment of the flexible guide used in the present invention will be described with reference to the drawings. As shown in FIGS. 1 and 2, the cylindrical flexible member 20 constituting the flexible guide 9 used in the present invention has a cylindrical inner flexible tube 11 having a through hole 21 through which the cable / hose 10 is inserted, as a core. A large number of small-diameter tubes 12 on the outer periphery and an outer cylinder tube 22 provided on the outer periphery of the small-diameter tube. The small-diameter tubes 12 are arranged along the inner flexible tube in a coaxial direction without many gaps. The outer cylinder tube 22 presses the small-diameter tube 12 and the inner flexible tube 11 from the outer periphery to regulate the radial and circumferential movements of the inner flexible tube and the small-diameter tube. Each component such as the inner flexible tube, the small diameter tube, and the outer cylinder tube is flexible and uses materials such as resin, rubber, bellows, and coil spring that are easy to bend, bend, and twist.

  As shown in FIG. 1, stepped cylindrical fixing portions 7 and 8 having opening holes are provided at both ends of the flexible member 20. The opening holes 7a and 8a of the fixed part have substantially the same diameter as the outer diameter of the inner flexible tube 11 and share the opening with the through hole 21. The fixing portion is a rigid body so that both ends of the flexible member 20 can be fixed. For example, a metal such as iron or aluminum, a highly rigid resin, or the like is used.

  In particular, in the present embodiment, as shown in FIGS. 1 to 3, the diagonal or opposite side position of the small-diameter tube 12 arranged circumferentially on the outer periphery of the inner flexible tube 11 (the central axis 20 a of the cross section of the flexible member 20). Wires (wires) 13 and 14 are inserted through the inside of a pair of symmetrical small diameter tubes as insertion holes 12a and 12b, respectively. Both ends of the wire are fixed to the fixing portions 7 and 8 by stoppers 15 and 16 that can adjust the fixing positions of the wires provided in the fixing portions, respectively. By changing the fixing position of the wire, the length of the wire, that is, the length between the fixed portions of the wire can be adjusted, and the lengths L1 and L2 between the fixed portions of the two wires are different and fixed. The small-diameter resin tubes 12 may be odd-numbered, even-numbered, and those having different diameters, and the pair of insertion holes need not be completely symmetric.

  Various methods can be used for the stoppers 15 and 16. Briefly, the wire insertion holes 7e and 8e are provided in the fixed portion, and the retaining portions 13a and 14a larger than the wire insertion holes are provided at the rear ends of the wires 13 and 14. The tip of the wire is inserted through the right wire insertion holes 7e and 7e and the insertion holes 12a and 12b in FIG. 1 and pulled out from the left wire insertion holes 8e and 8e so as to have a predetermined length. The tip may be caulked with caulking materials 15a and 16a that are larger than the wire insertion hole.

  When such a flexible guide is placed on a flat surface in a free state (planar circular arc state), due to the difference in length between the length L1 of the inner wire 13 arranged inside the arc and the length L2 of the outer wire 14 arranged outside the arc. A part of the donut shape, a half donut shape is formed. If the positions in the width direction of the fixing portions 7 and 8 at both ends are restricted, a U-shape or an Ω-shape is formed. In addition, the radius of curvature R in the planar arc state formed by the flexible guide 9 can be arbitrarily determined steplessly.

  Further, as shown in FIG. 3, the orientation of the fixing portions 7 and 8 so that the short-side wire (inner wire) 13 is on the lower side and the longer-side wire (outer wire) 14 is on the upper side. When the flexible guide 9 is bent into a U-shape and lifted, the flexible member 20 forms a U-shape that is wound around the virtual axis b in an arc shape with a radius r. By attaching the side portions 7d and 8d on the wire side on the short side of the fixed portion to the shafts relatively rotating on the same axis, the U-shaped flexible guide formed in this way is attached. A cable support device or the like that maintains a U-shape that wraps around the rotation shaft can be realized.

  Moreover, since a fluid can be flowed through the small diameter tube 12 as necessary, it is not necessary to pass a tube for piping through the inner flexible tube 11 and the inner flexible tube can be made thinner. In this case, a connection part such as a connection hole with a small diameter tube is provided on the fixed part side.

Next, another embodiment of the flexible guide 9 used in the present invention will be described. In the first embodiment , the small-diameter tube 12 is disposed on the outer periphery of the inner flexible tube 11 in order to maintain the positions of the wire members (wires) 13 and 14 of the flexible member 20 at the symmetrical position, the diagonal position, or the opposite side position. It may be a symmetrical position with respect to the central axis 20a of the flexible member 20, and may deviate from the center of the inner flexible tube 11. Further, it is not necessary for all the small diameter tubes 12 to have the same diameter.

Therefore, in the second embodiment of the flexible guide used in the present invention, as shown in FIG. 4A, the inner flexible tube 11 is inserted eccentrically so as to contact the inner wall of the outer cylinder tube 22, and the outer cylinder is inserted. A plurality of small-diameter tubes 12 'having different diameters are arranged in the gap between the inner tube and the inner tube, and two small-diameter tubes 12 for the through-holes 12a and 12b are provided at the central axis symmetrical position of the flexible member. Wires 13 and 14 were inserted through the wire. The small diameter tubes 12 and 12 ′ may have different hole diameters (including those without holes) and materials in addition to the diameter.

Moreover, when not using small diameter tube 12 'which is not used as insertion hole 12a, 12b by piping etc., an integral thing may be sufficient. Therefore, in the third embodiment of the flexible guide used in the present invention, as shown in FIG. 4 (b), the inner flexible tube 11 is inserted eccentrically so as to contact the inner wall of the outer cylinder tube 22, and the outer cylinder is inserted. A flexible inclusion 17 having a crescent-shaped cross section is provided so that the gap portion is fitted in the gap portion between the tube and the inner tube and the tip thereof is located at the center axis symmetrical position of the flexible member. Small diameter tubes 12 for insertion holes 12a and 12b were respectively provided at two positions between both ends of the inner flexible tube and the crescent-shaped inclusion 17, and wires 13 and 14 were inserted into the insertion holes.

Furthermore, the inner flexible tube 11 and the small diameter tubes 12a and 12b into which the wires 13 and 14 are inserted may be integrated. Further, it may be integrated with the outer tube 22. Therefore, in the fourth embodiment of the flexible guide used in the present invention, as shown in FIG. 4 (c), a through hole 21 is provided in an integrally molded flexible tube 20 ', and a central axis 20a is formed in the wall of the flexible tube. Two insertion holes 12a and 12b were provided at symmetrical positions, and the wires 13 and 14 were inserted into the insertion holes. Thereby, the number of parts can be further reduced.

Next, a cable support device for an industrial robot having the flexible guide of the present invention will be described with reference to the drawings. As shown in FIG. 5, the cable support device 51 of the industrial robot 50 of the present invention includes a first arm 1 serving as a base, and a rod-shaped first arm that is rotatable with respect to the arm support shaft 1 a of the first arm. It consists of the second arm 2 and the flexible guide 9 used in the present invention , through which the cable / hose 10 is inserted. The first arm 1 serving as a base is made swingable (arrow 56) around a shaft 55 of a swing arm (not shown) of an industrial robot, for example. In the drawing of the first arm 1, an arm support shaft 1 a is provided on the left output portion 1 b, and the base portion 2 b of the second arm 2 is rotatable relative to the support shaft with respect to the output portion 1 b of the first arm 1 ( Connected to arrow 57). In addition, other parts other than the first arm 1, the second arm 2, and the tip of the industrial robot are omitted.

  A bracket 3 extends from the first arm 1 toward the second arm 2. The fixed portion 7 provided at the first arm side end portion of the flexible guide 9 has the wire 13 side side surface portion 7d whose arm 7b has a length between the fixed portions so that the opening 7a faces downward, and the arm support axis line. It is being fixed to the edge part of the bracket 3 with the clamp 5 so that it may become 1a side. When the fixed portion 8 provided at the second arm side end of the flexible guide 9 is at the original position in the rotational direction of the second arm, the opening 8a faces downward and the length between the fixed portions is shortened. The clamps 6 are fixed to the side bracket 4 provided on the outer periphery of the second arm so that the side surface portion 8d on the wire 13 side is on the arm support axis 1a side.

  As a result, the flexible member 20 of the flexible guide 9 is deformed so as to be wound around the support shaft 1a line under the force of the wires 13 and 14 having different lengths and the gravity, and the U-shape as shown in FIG. Secure the shape. The cable / hose 10 has, from the first arm 1 side, an opening hole 7a of the fixing portion 7 on the first arm side of the flexible guide 9, a through hole 11a, and an opening hole 8a of the fixing portion 8 on the second arm side. And is disposed at the tip 52 of the second arm of the industrial robot. Therefore, the cable / hose 10 is also regulated in a U shape together with the flexible guide.

  FIG. 6 shows the state in which the flexible guide 9 is actually mounted between the relatively rotating shafts. The left and right sides of FIG. 5 are reversed, the left side is the base side, and the right side is rotated. The flexible guide 9 is the same as that of the first embodiment, but uses a wound spring for the outer cylinder and the inner flexible tube. As shown in FIG. 6 (C), the fixing portion 7 of the flexible guide 9 has the opening 7a facing downward, and the wire 13 side whose length between the fixing portions is shortened is the arm support shaft 1a side. Are fixed to a base (not shown). The other fixed portion 8 of the flexible guide 9 is positioned with respect to the support shaft so that the opening 8a faces downward and the wire 13 side whose length between the fixed portions is shortened is on the arm support axis 1a side. The rotating shaft (second arm) is fixed by a fixing member (not shown). This is the same as FIG.

  Next, when the rotation shaft is rotated rightward 58 around the support shaft 1a as shown in the drawing, the fixing portion 8 moves downward as shown in FIG. 6B, but the flexible member 20 maintains the U-shape. While being twisted, the state of winding around the support shaft 1a is maintained. Further, when the right rotation 59 is performed, as shown in FIG. 6A, the fixing portion 8 moves directly below, but the flexible member retains its shape. Further rotation increases the twist and increases the winding force.

  On the other hand, when the rotation axis is rotated 60 and 61 counterclockwise as shown in the drawing, as shown in FIGS. 6D and 6E, the fixing portion 8 moves upward, while the flexible member 20 maintains the U shape. The state of winding around the support shaft 1a is maintained. Further, when the counterclockwise rotation 62 is performed, as shown in FIG. 6F, the fixing portion 8 moves directly above, but the flexible member can maintain the shape.

  As described in FIG. 3, the radius r around which the U-shaped flexible guide wraps around the virtual axis b is substantially equal to the radius of curvature R in the planar arc state shown in FIG. Therefore, in order to obtain the desired radius r, the lengths L1 and L2 of the wires 13 and 14 are adjusted by adjusting the positions of the stoppers 15 and 16, and the curvature radius R in the planar arc state is adjusted. Further, since the length of the wires 13 and 14 can be adjusted even after the cable support device is mounted on the robot arm, the winding diameter after wiring construction can be easily changed or corrected.

  As described above, the cable support device 51 of the industrial robot 50 having the flexible guide 9 according to the present invention can arbitrarily adjust the radius of curvature of the arc formed by the flexible guide by adjusting the lengths of the two wires 13 and 14. A cable support structure can be provided that maintains a U-shape that wraps around the robot arm at any desired diameter. In addition, flexible members (inner flexible tubes, small diameter tubes, tubes for outer cylinders, etc.) and wire rods (wires) are continuous, and can be manufactured by cutting to the required length according to the amount of cable movement. A low-cost cable support device with few parts and easy assembly. Although the cable support for the industrial robot has been described, it goes without saying that it can be applied to other than the industrial robot as long as it has a mechanism that can rotate relatively on the same axis.

1 First arm 1a Arm support shaft 2 Second arm (rotating shaft)
7 (one) fixing part 8 (other) fixing part 7a, 8a Opening hole 7d, 8d Short wire side side part 9 Flexible guide.
10 Cable 11 Through-hole 12a, 12b Insertion hole 13 Wire (wire) (short side)
14 (long side) wire (wire)
20 Flexible member 20a Central axis 50 of cross section of flexible member Industrial robot 51 Cable support device.
L1, L2 Length between fixed parts

Claims (2)

An industrial robot having a first arm serving as a base and a rod-like second arm rotatably supported with respect to an arm support shaft of the first arm, a cylindrical flexible member; A fixing portion provided at both ends of the flexible member and having an opening hole that shares a through hole and an opening of the flexible member, and is formed symmetrically with respect to the central axis of the flexible member along the longitudinal direction of the flexible member. A pair of insertion holes and two wire rods inserted into the respective insertion holes, and both ends of the wire rod are fixed to the fixing portion, and the length between the fixing portions of the two wire rods The opening of the fixing portion at both ends of the flexible member is directed to the same direction around the arm support shaft, and the length of the wire of one of the fixing portions is shorter. Front side is front It is fixed to the first arm so as to be on the arm support axis side, the side surface portion of the other fixed portion on the side where the length of the wire is short is fixed to the outer periphery of the second arm, and the opening hole is formed. A cable support device for an industrial robot having a flexible guide through which a cable connecting between the first arm and the second arm is inserted into the through hole. The cable support device for an industrial robot having a flexible guide according to claim 1, wherein the opening hole of the fixing portion on the first arm side of the flexible guide is opened downward.

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