JP2010264525A - Cable arrangement structure of arc welding robot - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cable arrangement structure of an arc welding robot which easily carries out an inserting operation to a guide cylinder provided in a rotating shaft when a torch cable is attached. <P>SOLUTION: In a welding robot 10, the torch cable 30 is extended along the longitudinal direction of an upper arm 14. In the rotating shaft 16, the guide cylinder 50 is supported so as to freely rotate and extended in the longitudinal direction. An end part of the guide cylinder 50 is provided with a support wall 57 for supporting the torch cable 30, and an insert hole 58 for allowing the torch cable 30 to pass. An entire surface of an opening of the insert hole 58 is located in a position offset from a rotation axis 14a of the upper arm 14 in the rotating shaft 16. In the support wall 57, an insert guide surface 57b is formed which guides the torch cable 30 to the insert hole 58 when the torch cable 30 is inserted from a base end part of the guide cylinder 50. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a cable arrangement structure for an arc welding robot.

  In an arc welding robot that melts a welding wire (consumable electrode) with electric energy and continuously welds it, the welding wire fed from a wire reel or the like is fed to a welding torch, and wire feeding that feeds the welding wire Equipment.

  The arc welding robot generally has a multi-joint. For example, an arc welding robot has six joints from the first axis to the sixth axis, and rotates or twists each joint to cause the arm to rotate, swing, swing, or tilt, respectively. Change the position and orientation of the welding torch attached to the end effector. The wire feeding device is attached to a tilting table that supports an upper arm (hereinafter also referred to as a rotating arm) that rotates about an axis while tilting with a third shaft at the upper end of the lower arm in a standing posture.

  The wire reel to the wire feeding device are connected by a conduit pipe, and the torch cable is connected from the wire feeding device to the welding torch. In the conduit pipe, the cable guides the welding wire transition. The torch cable includes a conduit pipe for feeding a welding wire, a hose forming a passage for shield gas fed along the outer periphery thereof, a conductive wire for covering the outer periphery and supplying welding power, and an outermost periphery. It is composed of a multi-line single-wire power cable made of an insulating coating.

  As described above, since the torch cable has a multiple structure, it has a high bending rigidity and is difficult to bend. Therefore, in order to keep the welding torch from moving when it is moved, the welding torch is attached to the wire feeding device and the welding torch with an allowance in length.

  In the arc welding robot in which the torch cable is disposed, the torch cable passes on the longitudinal axis or in the vicinity thereof along the rotary arm so that the drive shaft and the joint part of the welding robot pass in particular. . This configuration minimizes deformation of the torch cable even when each axis, that is, each joint operates, as compared to the case where the wire feeding device to the welding torch are arranged outside the arm. Based on the insight that it can. This is because the joint center placement and axial placement are least affected by the rotation and tilting of the arm, and if the torch cable is placed at the joint center or axis, the cable will only exhibit the same degree of deformation in any direction. This is because it is considered.

  However, even when the torch cable is placed inside the drive shaft and joints, especially in the center, a robot that frequently uses bending motion or a robot that often maintains a bent state, and also has a large rotation angle and twist amount. It is not always ideal for a robot. For example, in the case of an arc welding robot, the quality of the weld pool formation affects the welding quality, so it is often necessary to give or maintain a desired posture on the welding torch. For example, in the case of a 6-axis robot, it is required to bend the fifth axis from 0 degrees to 120 degrees or keep the bent angle.

  In such a case, if the torch cable passes through the center of the drive shaft and the joint and passes along the longitudinal axis or the vicinity thereof along the rotary arm, The torch cable gradually moves away from the longitudinal axis of the rotating arm and deforms into a question mark (?) To achieve downward bending about the fifth axis. When the torch cable retains such a shape, stress accumulates in the conduit pipe at a portion that warps from the longitudinal axis of the rotating arm and a portion that curves sharply downward, leading to premature wear of the torch cable.

  Since the inner diameter of the conduit pipe is larger than the diameter of the welding wire, the radius of curvature at the curved portion does not match that of the conduit pipe and that of the welding wire. The difference in the radius of curvature causes the welding wire to rub at least at two locations before and after the bend. If the degree of curvature changes, the position where the conduit pipe and the welding wire are rubbed also changes. The frictional force acting between the conduit pipe and the welding wire fluctuates with each deformation of the conduit pipe, and the feeding speed becomes unstable.

  Further, when the bending amount (tilt angle) of the fifth axis is changed, the movement affects the upstream torch cable. That is, the bending of the cable changes between the fourth axis and the fifth axis, resulting in a difference between the length of the conduit pipe and that of the welding wire. The welding wire corresponding to the change in the length of the conduit pipe protrudes or retracts from the welding torch, and the wire supply amount changes undesirably. This disrupts the arc and makes it impossible to expect a significant improvement in welding quality.

  In Patent Document 1, the problem that cannot be achieved even with the internally installed torch cable as described above, that is, the influence on the upstream torch cable due to the persistence of the bending state at the joint and the repeated bending operation is possible. In order to improve the stability and durability of the welding wire feed. And it enables it to achieve high welding quality and to give a wide motion area and high mobility without deteriorating the operation specifications of the robot.

  More specifically, in the arc welding robot of Patent Document 1, as shown in FIG. 11, a rotating shaft body 103 serving as a rotating shaft is provided in a base end portion of a rotating arm 102 rotatably supported by a tilting table 101. Is provided so as to be rotatable around the rotation axis O, and a swing shaft (not shown) is disposed at the tip.

  A guide cylinder 104 is provided in the rotary shaft 103 so as to be freely supported and extend in the longitudinal direction. A support member 105 for supporting the torch cable T is integrally provided in the guide tube 104. The support member 105 is formed with an insertion hole 106 through which the torch cable T along the rotary arm 102 passes. The entire opening of the insertion hole 106 is provided in a position offset from the rotation axis O of the rotary arm 102 in the rotary shaft 103. As a result, even if the swinging shaft operates at the tip of the rotating arm 102 and the torch cable T is bent, the influence of the bending on the torch cable T located at a position offset from the rotating axis O is as much as possible. Can be reduced. For example, when the welding torch is raised or lowered by the movement of the swing shaft provided at the distal end portion of the rotary arm 102, the torch cable T is offset upward from the rotational axis O of the rotary arm 102 at the proximal end portion of the rotary arm 102. I can keep it.

JP 2005-238428 A

  By the way, in the welding robot of Patent Document 1 configured as described above, when the torch cable T is assembled or when the cable is replaced, the guide cylinder 104 assembled in the rotating shaft 103 is used. The insertion is made from the proximal end side or the distal end side. When the torch cable T is inserted into the guide cylinder 104, the entire opening of the insertion hole 106 is provided at a position offset from the rotation axis O. Compared with the case where it provides, the opening area of the insertion hole 106 becomes narrow. For this reason, there is a problem that it is difficult to insert the torch cable T. That is, as described above, since the torch cable T has a multiple structure, it has a high bending rigidity and is difficult to bend. Therefore, it is difficult to manually insert the insertion hole and it takes time and effort. In particular, when the support member 105 is provided on the tip end side with respect to the base end portion, the support member 105 is distal to the base end, so that the insertion operation of the torch cable T into the insertion hole 106 is difficult.

  An object of the present invention is to provide a cable arrangement structure for an arc welding robot capable of easily performing an insertion operation with respect to a guide tube provided in a rotating shaft when a torch cable is assembled. .

  In order to solve the above-mentioned problems, the invention according to claim 1 is directed to an interior of a rotary arm in which a swing shaft is provided at a distal end portion and a rotary shaft body having a rotary shaft around a longitudinal axis is provided at a base end portion. In the adjacent space, in order to suppress an increase in bending and twisting of the torch cable extending from the proximal end portion toward the distal end portion in association with the movement of each joint, the torch cable is made to follow the longitudinal direction of the rotary arm. In the arc welding robot cable arrangement structure, a guide cylinder that is rotatably supported and extends in the longitudinal direction is provided in the rotating shaft body, and the torch cable is provided at a distal end portion of the guide cylinder. And a through hole through which the torch cable extending along the rotary arm is passed, and the entire opening of the through hole is offset from the rotary axis of the rotary arm in the rotary shaft. In the cable arrangement structure of the arc welding robot according to claim 1, when the torch cable is inserted into the support portion from the proximal end portion of the guide tube, an insertion guide portion capable of guiding the torch cable into the insertion hole is provided. The gist is a cable arrangement structure of an arc welding robot characterized by being formed.

  According to a second aspect of the present invention, the torch cable support surface of the support portion facing the insertion hole and the insertion guide portion are continuously formed with a curved surface in the support portion according to the first aspect, and the torch cable support surface And the insertion hole is formed so that at least a support surface of the torch cable is exposed to the outside.

The invention of claim 3 is characterized in that, in claim 2, the torch cable support surface is formed in an arcuate cross section.
According to a fourth aspect of the present invention, in the second or third aspect, the insertion hole is formed by cutting out the tip of the guide tube.

  According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the guide tube includes a first guide tube body including the support portion and the insertion guide portion, and the first guide tube body. And a second guide cylinder that is detachably connected and supported so as to be freely rotatable with respect to the rotating shaft.

  According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the space for allowing the rotating arm to dispose a torch cable that goes out of the guide tube through an insertion hole of the guide tube. A guide cylinder is provided in a part of the rotation range of the rotation range in which the guide cylinder is free to rotate with respect to the rotary shaft body, and a flange formed so as to cover the insertion hole is provided. When the is positioned, the insertion hole is covered with the ridge.

  According to the first aspect of the present invention, when the torch cable is inserted from the proximal end of the guide tube at the time of cable assembly or cable replacement, the insertion guide portion provided on the guide tube guides the torch cable to the insertion hole. When assembling the torch cable or exchanging the cable, the insertion work can be easily performed with respect to the guide tube provided in the rotating shaft.

  According to the invention of claim 2, the torch cable support surface is exposed at least to the outside by the insertion hole. Therefore, when the torch cable is inserted from the support portion side at the distal end of the guide tube toward the base end, the torch cable support is supported. The surface can guide the insertion of the torch cable. Even in this configuration, the insertion operation can be easily performed with respect to the guide tube provided in the rotating shaft. Moreover, in the operation of the torch cable, the torch cable can be easily inserted into the guide tube from either the front end or the base end of the guide tube according to various work conditions.

  In addition, since the support surface of the torch cable of the support portion is continuously formed by the insertion guide portion and the curved surface, the joint of the welding robot is operated, the torch cable is operated, and the supported position with respect to the guide tube is Even if it changes, it can be supported not only on the support surface of the torch cable but also on the insertion guide portion. If the insertion guide part and the torch cable support surface are not continuous due to the curved surface, it will be supported by the edge of the torch cable support surface, and a load is applied to the contact area of the torch cable by the edge, and the torch cable is supported. Will speed up the damage. According to claim 2, such damage to the torch cable can be suppressed.

  According to the invention of claim 3, since the torch cable is formed in an arc shape in cross section and is formed as a rounded portion and has no sharp corner portion, an excessive load is partially applied to a portion where the torch cable is supported. Therefore, the torch cable is smoothly supported, and the operation of feeding the welding wire (consumable electrode) that is inserted into the torch cable and travels can be smoothly, that is, stabilized. As a result, the welding quality can be improved.

  According to the invention of claim 4, since the insertion hole is formed by cutting out the tip of the guide tube, the insertion hole of claim 2 can be easily formed, and the function and effect of claim 2 can be easily achieved. realizable.

  According to the invention of claim 5, since the first guide cylinder and the second guide cylinder are separable, when the first guide cylinder is worn by rubbing with the torch cable, Without removing the second guide cylinder from the rotating shaft, the worn first guide cylinder can be removed and replaced with a new first guide cylinder.

  According to the sixth aspect of the present invention, since the insertion hole can be covered with the scissors, it is possible to prevent the spatter generated during arc welding from entering the insertion hole. Also, depending on the welding position during arc welding, the torch cable may bend greatly toward the space above the rotary arm, but even if it is bent, the torch cable acts as a wall that suppresses the torch cable from protruding, so the torch cable Can be prevented from protruding greatly from the space above the rotary arm and interfering with external devices or the like. In addition, when the arc welding is stopped when the arrangement relationship between the ridge and the insertion hole is positioned vertically, dust and dust from above can be prevented from entering the insertion hole by the ridge.

BRIEF DESCRIPTION OF THE DRAWINGS The block diagram of the whole arc welding robot of one Embodiment which actualized this invention. FIG. 3 is a structural diagram of an upper arm portion showing a configuration structure of cables and the like in a robot arm. (A) is a schematic sectional drawing which shows the attachment structure of a guide cylinder, (b) is explanatory drawing of the plane P and opening area S1, S2. The top view of an upper arm. The perspective view of the 1st guide cylinder of a guide cylinder. The disassembled perspective view of the 1st guide cylinder and 2nd guide cylinder of a guide cylinder. (A) is a front view of the front-end | tip part of a guide cylinder, (b) And (c) is a front view of the front-end | tip part of other embodiment. The front view of an upper arm. The perspective view of an upper arm. The perspective view of an upper arm. FIG. 6 is a structural diagram of an upper arm portion showing an arrangement structure of cables and the like in a conventional robot arm.

Hereinafter, a first embodiment in which a cable arrangement structure of an arc welding robot according to the present invention is embodied will be described with reference to FIGS. 1 to 7A and FIGS.
An articulated arc welding robot (hereinafter referred to as a welding robot 10) includes six joints that move as indicated by arrows A to F in FIG. 1, and each rotates or twists to rotate, turn, Swing or tilt.

  Specifically, the base 11 fixed to the floor (not shown) is provided with a turning base 12 so as to be turnable around the first axis 11a (in the direction of arrow A in FIG. 1). A lower arm 13 is pivotally supported on the turning base 12 so as to be swingable around a second axis 12a (in the direction of arrow B in FIG. 1), which is a horizontal axis.

  At the upper end of the lower arm 13, an upper arm 14 as a rotating arm is pivotally supported around a third axis 13a which is a horizontal axis through a tilting table 15 as a support so as to be swingable in the vertical direction (C arrow direction). Yes. Further, the upper arm 14 rotates with respect to the tilting table 15 by a rotating shaft 16 as a rotating shaft provided so as to be rotatable around a rotating axis 14a as its own longitudinal axis as shown in FIG. The rotating shaft body 16 corresponds to a fourth axis.

  A torch support arm 17 is supported at the tip of the upper arm 14 by a swing shaft 18 as a fifth shaft so as to be tiltable or swingable. The swing shaft 18 functions as a mechanism for raising and lowering the welding torch 19 by tilting or swinging the torch support arm 17 at the tip of the upper arm 14. The torch support arm 17 corresponds to a wrist as an end effector. A welding torch 19 is attached to the tip of the torch support arm 17 so as to be pivotable on the sixth shaft 20 in the direction of arrow F in FIG.

Each joint having the first axis 11a to the sixth axis 20 is equipped with a motor via a reduction gear on the axis, and is driven in response to a command from a robot controller (not shown).
A mounting surface 15 a is formed on the upper surface of the tilting table 15. The mounting surface 15a is provided so as to be horizontal with respect to the upper arm 14 side in a state where the lower arm 13 is standing upright along the vertical direction (see FIG. 1).

  As shown in FIG. 2, a wire feeding device 22 for sending a welding wire (not shown) to the torch cable 30 is attached to the placement surface 15a. Further, as shown in FIG. 1, a conduit pipe 39 is connected to the wire feeding device 22, and a welding wire supplied from a wire reel (not shown) is guided.

  As shown in FIG. 2, a wire delivery port 24 as a wire exit is provided on the side surface of the upper side of the device main body case of the wire delivery device 22. The wire delivery port 24 is located in a space above the longitudinal axis of the upper arm 14. The reason why the wire delivery port 24 is offset upward from the rotational axis 14a in this way is that the welding wire is placed in an easy-to-straight state to keep the torch cable 30 along the longitudinal direction of the upper arm 14, and the degree of curvature is suppressed as much as possible. Because.

  Although not shown, the wire delivery port 24 is provided with a receiving mechanism to which a power cable that supplies power for welding and a gas hose that supplies shield gas are connected. The torch cable 30 is provided with a coil liner that guides its advancement and protects it from wrinkling at the center thereof. The coil liner functions as a conduit pipe. And the hose which covers the outer peripheral part is provided in the outer peripheral part of the coil liner, and the shield gas channel | path is formed between the hose and the coil liner outer peripheral part. Through the shield gas passage, the shield gas sent through the receiving mechanism flows and is guided to the welding torch. The outer circumference of the hose is covered with a conductive wire electrically connected to the power cable through a receiving mechanism. The entire torch cable 30 is provided with an insulating coating.

  Thus, the torch cable 30 is a one-wire power cable and has a multiple structure so that the welding wire, power, and shield gas can be supplied to the welding torch 19 simultaneously. For this reason, the torch cable 30 cannot be said to have high flexibility, and has sufficient rigidity to generate a force for twisting back when twisting acts. Therefore, although the torch cable 30 is arranged along the longitudinal direction of the upper arm 14, as shown by a two-dot chain line in FIG. 1, an initial bend is given against the restoring force. The torch cable 30 is provided in the welding robot 10 independently of a motor drive system cable (not shown).

Next, details of the upper arm 14 and its peripheral configuration will be described.
A bearing case 40 is provided at the upper end of the tilting table 15 as shown in FIGS. As shown in FIG. 3A, the rotating shaft body 16 of the upper arm 14 is rotatably supported in the support hole 40 a of the bearing case 40 via a plurality of bearings 41. As shown in FIG. 3A, the rotating shaft body 16 is fastened to the base end portion of the upper arm 14 by a bolt (not shown) and is integrally connected. In this way, the rotating shaft body 16 is supported by the bearing case 40 provided on the tilting table 15.

  The rotating shaft body 16 includes a speed reducer (not shown) provided on the output shaft of the motor 46 provided on the tilting table 15 shown in FIG. 1, a small pulley (not shown) provided on the output shaft of the speed reducer, and a rotating shaft body. It is driven via a transmission mechanism (not shown) comprising a large pulley (not shown) attached to the base end portion of 16 and a timing belt wound between the pulleys.

  As shown in FIG. 4, the center part and the front-end | tip part extended from the base end part of the upper arm 14 are offset to the side from the rotating axis 14a. A swing shaft 18 is provided at the tip of the upper arm 14. Then, the torch support arm 17 is tilted by the swing shaft 18. A torch support base 70 is provided at the tip of the torch support arm 17.

  As shown in FIG. 4, the torch cable 30 is connected to a welding torch 19 (see FIG. 1) via a space 62 on one side of the upper arm 14 and a side space 61 on the swing shaft 18 (fifth axis). Are arranged so as to pass along the rotation axis 14a. The space 62 corresponds to a space adjacent to the upper arm 14.

  As shown in FIG. 3A, the rotary shaft body 16 is formed in a cylindrical shape, and a guide cylinder 50 is supported by the bearing means 51 so as to be freely rotatable around the rotary axis 14a. Examples of the bearing means 51 include a roller bearing or a metal liner.

  The guide cylinder 50 includes a first guide cylinder 52 and a second guide cylinder 53. The second guide cylinder 53 is formed in a cylindrical shape from an insulating synthetic resin, and is supported so as to be free to rotate around the rotation axis 14 a with respect to the rotation shaft 16 via the bearing means 51. A plurality of connection holes 53 a are formed in the peripheral portion of the distal end portion of the second guide cylinder 53.

  The first guide cylinder 52 shown in FIG. 5 is formed of an insulating synthetic resin, and has a cylindrical cylinder part 55 formed so as to form a circular cross section from a substantially center to a base end part, and a cylinder part 55. And a support cylinder portion 56 formed integrally therewith. In addition, the material of the 1st guide cylinder 52 and the 2nd guide cylinder 53 is not limited to a synthetic resin, If it is a material which has insulation, it will not be limited.

  The base end portion of the first guide cylinder 52 is formed to have a size that fits in the distal end portion of the second guide cylinder 53, and a plurality of couplings corresponding to the coupling holes 53a are formed on the peripheral surface thereof. A claw piece 54 is formed. A claw portion 54a protrudes from the outer surface of the distal end of the connecting claw piece 54 and can be engaged with the connecting hole 53a. And the 1st guide cylinder 52 is connected by elastically engaging the nail | claw part 54a of the connection nail | claw piece 54 in the connection hole 53a in the state fitted inside with respect to the 2nd guide cylinder 53. ing. Further, in a state where the first guide cylinder 52 and the second guide cylinder 53 are connected, the connection claw piece 54 engaged with the connection hole 53a is disengaged against its elasticity, The first guide cylinder 52 is detachable from the second guide cylinder 53, that is, can be removed.

  As shown in FIG. 7A, when the front end surface of the support cylinder portion 56 is viewed from the front end as shown in FIG. 7A, more than half of the front end surface of the support cylinder portion 56 is blocked and the remaining portion is inserted. Opened as a hole 58. That is, the entire opening of the insertion hole 58 is offset from the rotation axis 14a.

  As shown in FIGS. 3A, 5, and 6, the support wall 57 has a curved surface because its inner surface is formed in an arc shape when viewed in cross-section along the axis of the support cylinder portion 56. have. Note that the axis of the support tube portion 56 coincides with the rotation axis 14a. And the end part inner surface (namely, curved surface) of the support wall 57 close | similar to the axial center of the support cylinder part 56 is the torch cable support surface 57a. The torch cable support surface 57a is formed in a circular arc shape in cross section.

  The support wall 57 having the torch cable support surface 57a corresponds to a support portion. The torch cable support surface 57a is located at a position offset from the rotation axis 14a as shown in FIGS. 7A and 8, and in this embodiment, when viewed from the front, the torch cable support surface 57a is orthogonal to the rotation axis 14a. It is formed to look like a straight line.

  As shown in FIG. 3 (a), the inner surface of the support wall 57 located below the torch cable support surface 57a in the state where the insertion hole 58 is disposed above the rotation axis 14a is an insertion guide surface as an insertion guide portion. 57b. The insertion guide surface 57b has a curved surface continuous with the torch cable support surface 57a.

  Here, the torch cable support surface 57a is a surface that mainly functions to support the torch cable 30 after the cable is attached or replaced. The insertion guide surface 57b (insertion guide portion) is connected to the torch cable support surface 57a when the torch cable 30 is inserted from the proximal end side of the guide tube 50 when the cable is attached or replaced. 30 is a surface that guides 30 to the insertion hole 58.

  As shown in FIG. 3A, the insertion hole 58 is located above the torch cable support surface 57a in the state where the tip of the torch cable support surface 57a is disposed upward from the rotation axis 14a at the tip of the support cylinder portion 56. The portion located at is formed by cutting out a slanted shape with respect to the rotation axis 14a.

  By forming the insertion hole 58 in this way, the entire torch cable support surface 57 a is exposed by the insertion hole 58. In the present embodiment, the insertion hole 58 is exposed through the insertion hole 58 so that the insertion guide surface 57b can be seen from the outside as shown in FIGS.

  Such an insertion hole 58 can be obtained by, for example, cutting it obliquely with respect to the rotation axis 14a (that is, the axis of the support cylinder portion 56) as a reference line. As shown in FIG. 3 (a), the opening angle of the insertion hole 58 can be increased as the skew angle [theta] lies with respect to the rotation axis 14a, that is, the smaller the angle [theta] becomes an acute angle.

Here, the angle θ will be described.
In FIG. 3 (a), P denotes the tip edge 57c of the torch cable support surface 57a and the support cylinder portion 56 positioned in the direction in which the torch cable support surface 57a is offset from the rotation axis 14a (see the arrow in FIG. 7). The plane containing the outer peripheral part 56a is represented.

  The angle θ is an angle formed with the rotation axis 14a when the plane P is a cut surface. In the present embodiment, the insertion hole 58 is formed by cutting the tip of the support cylinder portion 56 so as to be substantially along the plane P. And in this embodiment, as shown to Fig.3 (a), the outer shape line 58a of the penetration hole 58 is further formed so that it may curve below in the arc form rather than what was cut by the plane P. As shown in FIG.

  In order to form the insertion hole 58, it is not necessary to be curved in an arc as described above, and it may be cut along the plane P. Alternatively, in FIG. You may make it cut and curve upwards. Further, the outline 58a is not limited to a straight line or an arc shape in FIG. 3A, and the entire torch cable support surface 57a or at least one of the entire torch cable support surface 57a and the insertion guide surface 57b. What is necessary is just to be cut so that a part may be exposed by the penetration hole 58. FIG.

  The shape of the insertion hole 58 may be a shape that allows the relative movement of the guide tube 50 relative to the torch cable 30 when the guide tube 50 rotates around the rotation axis 14a. Since the insertion hole 58 is formed in this manner, the stress accumulated in the torch cable 30 can be reduced even if the upper arm 14 and the support wall 57 as the support portion rotate or do not rotate relative to each other.

  Further, since the insertion hole 58 is configured as described above, the insertion hole is arranged along the surface cut in the diameter direction of the support cylinder portion 56 and is compared with a case where the insertion hole 58 is offset from the rotation axis 14a. Thus, the opening area of the insertion hole 58 formed by cutting in an oblique shape can be widened.

  The reason for this will be explained. As shown in FIGS. 3A and 3B, the opening area of the insertion hole 58 formed by cutting the support cylinder 56 obliquely by the plane P is S1, and the support cylinder part 56 is cut in the diameter direction. The opening area of the insertion hole 106 formed along the plane P1, that is, the plane P1 orthogonal to the rotation axis 14a is defined as S2. In this case, the opening area S2 of the insertion hole 106 corresponds to an area (projected area) obtained by projecting the opening area S1 of the insertion hole 58 included in the plane P. Here, the opening area S2 corresponds to the opening area of the insertion hole 106 having a conventional configuration. Therefore, as shown in FIG. 3B, S1> S2.

  Thus, in the present embodiment, the entire opening area of the insertion hole 58 is offset from the rotation axis 14a, but the opening area S1 has a wider area than that of the conventional configuration. become. Therefore, when the torch cable 30 is inserted from the insertion hole 58 at the distal end of the guide tube 50 toward the proximal end of the guide tube 50, the torch cable 30 can be easily inserted.

  The torch cable 30 is inserted substantially linearly into the insertion hole 58 from the end connected to the wire delivery port 24, and is supported by the torch cable support surface 57a. As shown in FIG. 2, the torch cable 30 extends upward and curves downward from the portion supported by the torch cable support surface 57a as shown by the solid line in FIG. 2 and the two-dot chain line in FIG. To do. The torch cable 30 extends downward from the curved portion (that is, the inflection point Q) and is connected to the welding torch 19. Due to the insertion hole 58, the torch cable 30 is kept offset from the rotation axis 14a.

  In addition, since the support wall 57 is integrally provided with respect to the guide tube 50, the guide tube 50 that rotates relative to the upper arm 14 prevents the torch cable 30 from being loosened and wobbled, and the torch cable 30 is useless. Deformation is prevented. If the material of the guide tube 50 is an insulating synthetic resin molded product, the torch cable 30 can be insulated. Further, since the support wall 57 rotates freely together with the guide tube 50, the relative rotation of the torch cable 30 with respect to the upper arm 14 becomes smoother.

  Further, as shown in FIGS. 1 to 4 and FIGS. 8 to 10, the upper arm 14 is provided with a flange 60 at a portion corresponding to the insertion hole 58 of the guide tube 50. The flange 60 is provided so as to be separated from the torch cable 30 so as not to interfere with a portion of the torch cable 30 that goes out from the insertion hole 58. That is, the flange 60 is formed in the upper arm 14 so as to sandwich a space allowing the arrangement of the torch cable 30 that goes out of the guide tube 50 from the insertion hole 58 of the guide tube 50.

  When the guide tube 50 is located in a part of the rotation range in which the guide tube 50 rotates with respect to the rotating shaft body 16, the insertion hole 58 is connected to the outside of the guide tube 50. It is made to cover with the ridge 60 through the space which permits arrangement | positioning of 30. FIG.

  When the rotation position of the guide tube 50 is positioned so as to face the insertion hole 58 and the flange 60, the flange 60 prevents dust, dust, spatter during arc welding, and welding fume from entering the insertion hole 58. Stop. For example, when the rotation position of the guide tube 50 is positioned so that the insertion hole 58 faces upward as shown in FIG. 2 and the flange 60 is positioned above the insertion hole 58 so as to face the insertion hole 58, The rod 60 prevents dust, dirt, spatter during arc welding and welding fume from entering the insertion hole 58 from above the upper arm 14.

(Operation of the embodiment)
In the welding robot 10 configured as described above, when the torch cable 30 is inserted into the guide tube 50 attached to the rotary shaft body 16, the surrounding environment of the robot at the time of cable attachment or cable replacement, work sequence, etc. Depending on various work conditions, there are a case where the guide tube 50 is inserted from the proximal end side and a case where the guide tube 50 is inserted from the distal end side.

  When the torch cable 30 is inserted from the proximal end side of the guide cylinder 50, the distal end portion of the torch cable 30 is inserted from the proximal end side of the guide cylinder 50 in a state where the wire feeding device 22 is not attached to the placement surface 15a. insert. In this case, when the tip of the torch cable 30 inserted into the guide tube 50 hits the insertion guide surface 57b of the guide tube 50, it is guided to the insertion hole 58 by the insertion guide surface 57b. As a result, the torch cable 30 can be easily taken out from the insertion hole 58 to the tip of the guide tube 50.

  On the other hand, when the torch cable 30 is inserted from the distal end side of the guide tube 50, the proximal end of the torch cable 30 is inserted into the insertion hole 58. In this case, the entire opening area of the insertion hole 58 of the present embodiment is offset from the rotation axis 14a, but the opening area S1 has a larger area than that of the conventional configuration. For this reason, when the torch cable 30 is inserted from the insertion hole 58 at the distal end of the guide tube 50 toward the proximal end of the guide tube 50, the torch cable 30 can be easily inserted. The torch cable support surface 57a can guide the insertion of the torch cable 30.

Now, according to the welding robot 10 of this embodiment, there exist the following characteristics.
(1) The welding robot 10 of the present embodiment includes an upper arm 14 (rotating arm) in which the swing shaft 18 is provided at the distal end and the rotary shaft 16 around the rotational axis 14a (longitudinal axis) is provided at the proximal end. Prepare. Also, in the upper arm 14 or in the adjacent space, the torch cable 30 is connected to the upper arm in order to suppress an increase in bending or twisting of the torch cable 30 extending from the proximal end portion toward the distal end portion accompanying the operation of each joint. 14 along the longitudinal direction. A guide cylinder 50 is provided in the rotary shaft 16 so as to be freely supported and extend in the longitudinal direction. A support wall 57 (support portion) for supporting the torch cable 30 and an insertion hole 58 for passing the torch cable 30 along the upper arm 14 are formed at the distal end portion of the guide tube 50, and the opening of the insertion hole 58 is formed. The entire surface is located at a position offset from the rotation axis 14 a of the upper arm 14 in the rotation shaft body 16. The support wall 57 is formed with an insertion guide surface 57b (insertion guide portion) capable of guiding the torch cable 30 into the insertion hole 58 when the torch cable 30 is inserted from the proximal end portion of the guide tube 50. Yes.

  As a result, when the torch cable 30 is inserted from the proximal end of the guide tube 50 at the time of cable assembly or cable replacement, the insertion guide surface 57b guides the torch cable 30 to the insertion hole 58. When assembling or exchanging cables, the insertion work can be easily performed with respect to the guide tube 50 provided in the rotary shaft body 16.

  (2) In the present embodiment, the torch cable support surface 57a and the insertion guide surface 57b (insertion guide portion) of the support wall 57 facing the insertion hole 58 are formed continuously on the support wall 57 (support portion) with a curved surface. ing. An insertion hole 58 is formed so that at least the torch cable support surface 57a is exposed to the outside of the torch cable support surface 57a and the insertion guide surface 57b.

  As a result, the insertion hole 58 exposes the torch cable support surface 57 a at least to the outside, so that the torch cable 30 is inserted toward the base end of the guide cylinder 50 from the support wall 57 (support portion) side at the distal end of the guide cylinder 50. In some cases, the torch cable support surface 57 a can guide the insertion of the torch cable 30, and the insertion work can be easily performed with respect to the guide tube 50. Moreover, in the operation of the torch cable 30, the torch cable can be easily inserted into the guide tube from either the front end or the base end of the guide tube according to various work conditions.

  Further, since the torch cable support surface 57a of the support wall 57 is continuously formed by the insertion guide surface 57b and the curved surface, the joint of the welding robot 10 is operated, the torch cable 30 is operated, and the guide cylinder 50 is operated. Even if the position to be supported is changed, it can be supported not only on the torch cable support surface 57a but also on the insertion guide surface 57b. If the insertion guide surface 57b (insertion guide portion) and the torch cable support surface 57a are not continuous due to a curved surface, the support surface is supported by the edge of the torch cable support surface 57a. A load is applied to the contact portion 57a, and damage to the torch cable 30 is accelerated. According to this embodiment, such damage of the torch cable 30 can be suppressed.

  (3) In the welding robot 10 of the present embodiment, the torch cable support surface 57a is formed in a cross-sectional arc shape. As a result, since the torch cable 30 is formed in a circular arc shape and has no sharp corners, it is possible to prevent an excessive load from being partially applied to a portion where the torch cable 30 is supported. It will be supported smoothly, and the operation of feeding the welding wire that is inserted into the torch cable 30 and travels can be smoothly, that is, stabilized. As a result, the welding quality can be improved.

  (4) In the welding robot 10 of the present embodiment, the insertion hole 58 is formed by cutting out the tip of the guide tube 50, whereby the insertion hole 58 described in (2) can be easily formed. The effect (2) can be easily realized.

  (5) In the welding robot 10 of the present embodiment, the guide cylinder 50 includes a first guide cylinder 52 including a support wall 57 (support part) and an insertion guide surface 57b (insertion guide part), and a first guide cylinder 52. And a second guide cylinder 53 supported so as to be freely rotatable with respect to the rotary shaft body 16. As a result, since the first guide cylinder 52 and the second guide cylinder 53 are separable, when the first guide cylinder 52 is worn by rubbing with the torch cable 30, the second guide cylinder 52 and the second guide cylinder 53 are separated. The worn first guide cylinder 52 can be removed and replaced with a new first guide cylinder 52 without removing the guide cylinder 53 from the rotary shaft body 16.

  (6) In the welding robot 10 of the present embodiment, the upper arm 14 (rotating arm) is disposed so as to sandwich a space allowing the torch cable 30 to be disposed outside the guide tube 50 from the insertion hole 58 of the guide tube 50. In addition, a flange 60 formed so as to cover the insertion hole 58 is provided. And when the guide cylinder 50 is located in a part of rotation range among the rotation ranges in which the guide cylinder 50 rotates with respect to the rotating shaft body 16, the insertion hole 58 is covered with the flange 60. .

  As a result, according to the present embodiment, since the insertion hole 58 can be covered with the flange 60, it is possible to prevent spatter generated during arc welding from entering the insertion hole 58. Also, depending on the welding position during arc welding, the torch cable may bend greatly toward the space above the rotary arm, but even if it is bent, the torch cable acts as a wall that suppresses the torch cable from protruding, so the torch cable Can be prevented from protruding greatly from the space above the rotary arm and interfering with external devices or the like. Further, when the arc welding is stopped when the rod 60 is positioned above the insertion hole 58, the rod 60 can prevent dust and dust from entering the insertion hole 58 from above.

In addition, you may change embodiment of this invention as follows.
In the embodiment, the welding robot 10 is of a type in which the base 11 is fixed to the floor surface, but may be embodied as a welding robot that supports the base 11 on the ceiling.

  -In the said embodiment, as shown to Fig.7 (a), the torch cable support surface 57a is formed so that it may look linearly so that it may orthogonally intersect with the rotating shaft line 14a when it looks front. Instead of making it look like this straight line, the left and right ends of the torch cable support surface 57a in FIG. 7B may be curved so as to be positioned below the center. Alternatively, in FIG. 7B, the left and right ends of the torch cable support surface 57a may be curved so as to be positioned above the center.

  In the above embodiment, the torch cable support surface 57a and the insertion guide surface 57b are continuously formed with curved surfaces, but the torch cable support surface 57a and the insertion guide surface 57b may be separated. For example, a step or groove may be provided between the torch cable support surface 57a and the insertion guide surface 57b. In this case, it is preferable that the edge part which divides the torch cable support surface 57a and a groove | channel or a step part forms round.

  In the above embodiment, the tip surface of the guide tube 50 is formed so as to block all the portions other than the insertion hole 58. However, under the condition that the guide function of the insertion guide surface 57b is not lost on the inner surface of the support wall 57, A part may open to the outside.

  In the embodiment, the guide cylinder 50 is formed by the first guide cylinder 52 and the second guide cylinder 53 and can be separated from each other. However, after the assembly, the guide cylinder 50 may be connected so as not to be separated. . For example, the connecting portions between the first guide cylinder 52 and the second guide cylinder 53 may be bonded with an adhesive.

  In the above embodiment, the guide cylinder 50 is configured by two members, the first guide cylinder 52 and the second guide cylinder 53, but the entire guide cylinder 50 may be configured by one member.

14 ... Upper arm (rotating arm), 14a ... Rotating axis, 16 ... Rotating shaft,
18 ... oscillating shaft, 10 ... welding robot, 30 ... torch cable,
50 ... guide cylinder, 52 ... first guide cylinder, 53 ... second guide cylinder,
57 ... support wall (support part), 57a ... torch cable support surface,
57b ... Insertion guide surface (insertion guide part), 58 ... Insertion hole, 60 ... Spear.

Claims (6)

The pivot shaft is located at the distal end, and the rotary shaft having a rotational axis around the longitudinal axis is located at the proximal end of the rotary arm or in the adjacent space. In order to suppress an increase in bending and twisting of the torch cable extending toward the tip, a cable arrangement structure for an arc welding robot in which the torch cable is arranged along the longitudinal direction of the rotary arm, Is provided with a guide cylinder that is rotatably supported and extends in the longitudinal direction, and a support part for supporting the torch cable and a torch cable extending along the rotary arm at a tip part of the guide cylinder. In the cable arrangement structure of the arc welding robot, the insertion hole to be passed is formed, and the entire opening of the insertion hole is located at a position offset from the rotation axis of the rotary arm in the rotary shaft.
An arc welding robot, wherein the support portion is formed with an insertion guide portion capable of guiding the torch cable into the insertion hole when the torch cable is inserted from a proximal end portion of the guide tube. Cable arrangement structure. In the support part, the torch cable support surface of the support part facing the insertion hole and the insertion guide part are continuously formed by a curved surface,
2. The cable for an arc welding robot according to claim 1, wherein the insertion hole is formed so that at least the torch cable support surface of the torch cable support surface and the insertion guide portion is exposed to the outside. Arrangement structure.   The cable arrangement structure for an arc welding robot according to claim 2, wherein the torch cable support surface is formed in a circular arc shape in cross section.   The cable insertion structure for an arc welding robot according to claim 2 or 3, wherein the insertion hole is formed by cutting out a tip of the guide tube.   The guide tube detachably connects the first guide tube body including the support portion and the insertion guide portion, and the first guide tube body, and is supported so as to be freely rotatable with respect to the rotating shaft body. The cable arrangement structure for an arc welding robot according to any one of claims 1 to 4, further comprising a second guide cylinder. The rotary arm is provided with a flange that is arranged so as to sandwich a space allowing the arrangement of the torch cable that goes out of the guide cylinder from the insertion hole of the guide cylinder and covers the insertion hole. ,
2. The insertion hole is covered with the flange when the guide tube is positioned in a part of the rotation range of the rotation range in which the guide tube is free to rotate with respect to the rotating shaft body. The cable installation structure of the arc welding robot according to any one of claims 5 to 5.

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