JP2009006454A - Method for installing wire feeder of welding robot, structure for installing wire feeder of welding robot, and welding robot - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for installing a wire feeder of a welding robot capable of reducing a deformed point of a torch cable arranged for each welding torch via an inner space of a rotary arm from the wire feeder, or reducing warps at a portion passing from the inner space to restrain bad influences on welding; an installation structure, and a welding robot. <P>SOLUTION: In this welding robot, a wire delivery outlet 24 of a wire feeder 22 is positioned below a rotary axis 14a of an upper arm 14 and directed diagonally upward relative to the rotary axis 14a. The wire feeder 22 is installed so that a torch cable 30 connected to the wire delivery outlet 24 crosses from downward to upward of the rotary axis 14a in the inner space SP. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for installing a wire feeding device in a welding robot, a structure for installing a wire feeding device in a robot arm, and a welding robot.

  Arc welding robots (hereinafter referred to as welding robots) generally have multiple joints. For example, the six joints from the first axis to the sixth axis are rotated or twisted to rotate and rotate the arms. The position or posture of the welding torch attached to the end effector such as the wrist is changed by swinging or tilting.

  The welding robot is equipped with a wire feeding device that feeds the welding wire. That is, 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 the axis while being tilted by the third shaft at the upper end of the lower arm in a standing posture.

The wire feeding device is composed of several rolls that compress the welding wire, and feeds the welding wire toward the welding torch by the frictional force thereof.
The cable from the wire reel to the wire feeding device and the wire feeding device to the welding torch are connected by cables. The former cable is a conduit pipe that guides the transition of the welding wire. The latter includes not only a conduit pipe that feeds a welding wire, but also a hose that forms a passage for shield gas that is fed along the outer circumference, a conductive wire that covers the outer circumference and supplies welding power, and It is a one-line power cable (torch cable) having a multiple structure consisting of an outer peripheral insulation coating.

  Conventionally, the torch cable has a high bending rigidity and is difficult to bend. Therefore, the torch cable is attached with a sufficient length in order to keep the welding torch small when moving. That is, the torch cable is arranged outside so as to be located in the outer space of the rotary arm from the wire feeding device to the welding torch in order to allow the torch cable to be deformed.

  However, if the torch cable is arranged outside, a trouble that the torch cable interferes with the workpiece or surrounding devices will occur and directly affect the work. Therefore, in recent years, the torch cable is placed in the internal space of the rotary arm. There has been proposed a welding robot having a configuration of being inserted and arranged (Patent Literature 1, Patent Literature 2).

  In the welding robots of Patent Literature 1 and Patent Literature 2, the outlet of the welding wire of the wire feeder and the torch cable attached to the outlet are both arranged in parallel to the rotation axis of the rotary arm, and the torch cable is provided on the end effector. Connected to the welding torch. The rotating arm is rotated around the rotation axis.

In FIG. 6, the shape of a torch cable K as an example of the prior art is indicated by a two-dot chain line, and the torch cable K is disposed in parallel to the rotation axis 14 a in the internal space SP of the rotating arm. As shown in the figure, in the internal space SP of the rotary arm, the torch cable K is arranged substantially linearly in parallel with the rotation axis 14a, and from the position where it exits the internal space SP, the straight line portion is directed upward. An inflection point H1 that is an arc is formed, and subsequently, an arc that is directed downward is formed and disposed up to a welding torch (not shown).
JP 2005-238428 A Japanese Patent Laid-Open No. 2003-200376

  In the arrangement state of the torch cable as described above, the inflection point H1 of the portion from the straight portion to the arc influences the feeding property of the welding wire, so that the feeding resistance of the welding wire increases. Since the feeding motor of the wire feeding device is normally controlled to have a constant speed by increasing or decreasing the torque, when the feeding resistance increases, that is, when the load fluctuates, The speed fluctuates from moment to moment, resulting in uneven speed. If this speed unevenness occurs, the welding is adversely affected.

  Therefore, the number of inflection points of the torch cable arranged from the wire feeding device to the welding torch through the internal space of the rotating arm is reduced, or the inflection at the portion of the torch cable passing through the internal space of the rotating arm. There is a demand for a method, structure, and welding robot that can reduce the warping of the points and suppress adverse effects on welding.

  The object of the present invention is to reduce the inflection point of the torch cable arranged from the wire feeding device to the welding torch through the internal space of the rotary arm, or to allow the portion passing from the internal space to be warped up. It is an object of the present invention to provide a method of installing a wire feeding device in a welding robot that can reduce the number of times and reduce adverse effects on welding.

  Another object of the present invention is to reduce the inflection point of the torch cable arranged from the wire feeding device to the welding torch through the internal space of the rotary arm, or warp of the portion passed from the internal space. It is an object of the present invention to provide an installation structure of a wire feeding device in a welding robot that can reduce as much as possible the rise and suppress adverse effects on welding.

  Another object of the present invention is to reduce the inflection point of the torch cable arranged from the wire feeding device to the welding torch through the internal space of the rotary arm, or warp of the portion passed from the internal space. It is an object of the present invention to provide a welding robot that can reduce the rise as much as possible and suppress adverse effects on welding.

  In order to solve the above-mentioned problems, the invention according to claim 1 is characterized in that a joint provided with a swing shaft for swinging the end effector is provided at the distal end, and a joint provided with a rotation shaft around the longitudinal axis is provided at the proximal end. A rotating arm provided in a section, a torch cable extending through the internal space of the rotating arm to a welding torch provided in the end effector and allowing a welding wire to pass therethrough, and a proximal end of the rotating arm In a method of installing a wire feeding device in a welding robot provided with a wire feeding device that is arranged on the part side and that feeds the welding wire, a wire outlet of the wire feeding device is connected to the rotating arm. The torch cable that is located below the longitudinal axis and that faces obliquely upward with respect to the longitudinal axis and that is connected to the wire outlet, in the internal space, It is an gist method of installing wire feeder in a welding robot, characterized in that the serial longitudinal axis from below installing wire feeder so as to intersect upward.

  According to a second aspect of the present invention, there is provided a rotary arm having a joint provided with a swing shaft for swinging an end effector at a distal end and a joint provided with a rotary shaft around a longitudinal axis at a base end, and the rotary arm A torch cable that passes through the internal space of the end effector and extends to a welding torch provided on the end effector, and is disposed on the base end side of the rotary arm, In the installation structure of the wire feeding device in the welding robot provided with the wire feeding device that applies feeding, the wire outlet of the wire feeding device is located below the longitudinal axis of the rotating arm, and The wire feeding device is installed on a support that rotatably supports the rotating arm around the longitudinal axis so as to be inclined obliquely upward with respect to the longitudinal axis, and the wire outlet The gist of the installation structure of the wire feeding device in the welding robot, wherein the torch cable to be connected is arranged in the internal space so as to cross the longitudinal axis from below to above. It is.

  According to a third aspect of the present invention, in the inner space of the rotating arm according to the second aspect, a rotating shaft body positioned at a proximal end portion of the rotating arm is provided as the rotating shaft, and a support member is provided on the rotating shaft body. The support member is provided with a through hole that allows the torch cable to pass therethrough and allows the torch cable to cross the longitudinal axis from below to above in the internal space. To do.

  The invention of claim 4 is the invention according to claim 3, wherein the through hole is a long hole formed so as to surround the longitudinal axis, and when the rotating arm rotates around the longitudinal axis, Movement around the longitudinal axis of the torch cable is allowed in the through hole.

According to a fifth aspect of the present invention, in the fourth aspect, the support member is supported so as to be freely rotatable within the rotating shaft.
A sixth aspect of the present invention is characterized in that, in the third or fourth aspect, the support member is provided on a guide cylinder that is supported so as to be freely rotatable in the rotary shaft body.

  The invention of claim 7 is the wire feeding device according to claim 5 or 6, wherein the wire feeding device follows the movement of the torch cable supported by the support member when the support member is idle. It is characterized by being swingably supported with respect to the support.

The invention of claim 8 is characterized in that, in any one of claims 2 to 7, the torch cable is a one-wire power cable.
A ninth aspect of the invention is a welding robot comprising the wire feeding device installation structure according to any one of the second to eighth aspects.

A tenth aspect of the present invention is the multi-joint arc welding robot according to the ninth aspect.
An eleventh aspect of the invention is characterized in that, in the tenth aspect, the rotation shaft and the swing shaft are a fourth axis and a fifth axis in a six-axis manipulator.

  According to the invention of the method of claim 1, the inflection point of the torch cable arranged from the wire feeding device to the welding torch through the internal space of the rotary arm can be reduced, or the warp from the support member can be reduced. It can be reduced as much as possible, and adverse effects on welding can be suppressed.

  According to the installation structure of the wire feeding device of claim 2, the inflection point of the torch cable arranged from the wire feeding device to the welding torch through the internal space of the rotary arm can be reduced, or from the support member. It is possible to reduce the warpage of the weld as much as possible and to suppress the adverse effect on the welding.

  According to the invention of claim 3, by passing the torch cable through the through hole of the support member, it is possible to allow the torch cable to cross the longitudinal axis from below to above and torch the cable in the internal space. Can be in a straight line state.

  According to a fourth aspect of the present invention, when the rotary arm rotates around the longitudinal axis, the longitudinal axis is moved downward by allowing movement around the longitudinal axis of the torch cable in the through hole. The state of crossing upward from is maintained. In addition, since the through hole is formed in an arc-shaped long hole so as to surround the longitudinal axis, the relative movement of the torch cable which is to be pulled by twisting when the rotating arm rotates is allowed. Therefore, the rotation of the rotary arm can be prevented from affecting the torch cable. As a result, stress accumulated in the torch cable can be reduced or released.

  According to the fifth aspect of the present invention, since the support member is free to rotate in the rotating shaft, the support member can be rotated relative to the rotary arm. In addition, when the rotating arm rotates around the longitudinal axis, the support member is rotated as described above even if the rotating arm rotates more than the limit of absorbing the displacement of the torch cable through the long hole. It is possible to maintain a state where the axis intersects from below to above.

  According to the sixth aspect of the present invention, since the support member is provided in the guide cylinder that rotates freely within the rotating shaft, the guide cylinder that rotates relative to the rotary arm prevents the torch cable from loosening and wobbling, and the torch Unnecessary deformation of the cable can be prevented. Further, since the support member rotates freely together with the guide cylinder, the relative rotation of the torch cable with respect to the rotating arm can be made smoother.

  According to the seventh aspect of the present invention, when the support member swings, when the support member moves to the torch cable supported by the support member, the wire feeding device follows the movement of the support member. Since it swings, accumulation of stress on the torch cable can be suppressed.

  According to the invention of claim 8, if the torch cable is a one-line power cable in which a welding wire fed from a wire feeding device advances in the center, arc welding of a welding wire, welding power, and welding shielding gas is used. Indispensable to the welding torch can be supplied via a single cable.

  According to the invention of claim 9, the effects of claims 2 to 9 are more remarkably exhibited as a welding robot by providing the welding robot with the installation structure of the wire feeding device of claims to 9. Is done.

  According to the invention of claim 10, when the welding robot is an articulated arc welding robot, the effects of claims 2 to 9 are more remarkably exhibited in the articulated arc welding robot.

  According to the eleventh aspect of the present invention, if the wire feeding device installation structure is applied between the fourth axis and the fifth axis in the six-axis manipulator, the bending of the fifth axis and the repetition of the bending operation are reduced. Minimize the impact on the upstream torch cable leading to the four axes. In addition, the operating range of the welding torch is expanded and the operating speed is increased, and the welding wire feedability is enhanced to achieve high quality welding, and the durability of the conduit pipe connected to the wire feeding device is improved. Figured.

(First embodiment)
A wire feed device installation method, a wire feed device installation structure, and an arc welding robot according to a first embodiment of the present invention will be described with reference to 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. 3A, and each of them rotates or twists to form an arm. Rotate, turn, swing or tilt.

  Specifically, the base 11 is provided with a turning base 12 that can turn around the first axis 11a (in the direction of arrow A in FIG. 3A). A lower arm 13 is pivotally supported on the swivel base 12 so as to be swingable around a second axis 12a which is a horizontal axis (in the direction of arrow B in FIG. 3A).

  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 is rotated by a rotating shaft body 16 as a rotating shaft provided so as to be rotatable around a rotating axis 14 a as its own longitudinal axis with respect to the tilting table 15. 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 directed obliquely upward 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. 3A). A wire feeding device 22 for sending the welding wire 31 to the torch cable 30 is attached to the placement surface 15a. In this embodiment, the mounting surface 15a is used. However, instead of the mounting surface 15a, a mounting table is provided on the tilting table 15, and the surface on which the wire feeding device 22 of the mounting table is mounted is mounted. Similarly to the surface 15a, the upper arm 14 may be provided so as to go obliquely upward.

Further, as shown in FIG. 3A, 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. 1, a wire delivery port 24 as a wire exit is provided on the side surface of the upper arm side of the device main body case 23 of the wire delivery device 22. The wire delivery port 24 is located below the longitudinal axis of the upper arm 14 and is disposed such that its central axis 24a intersects the rotational axis 14a of the upper arm 14. That is, the wire delivery port 24 is located below the rotation axis 14a (longitudinal axis) of the upper arm 14 and is disposed obliquely upward with respect to the rotation axis 14a.

  The reason why the wire delivery port 24 intersects the rotation axis 14 a from the lower side to the upper side in this way is that the welding wire 31 is easily moved straight when the torch cable 30 connected to the wire delivery port 24 runs along the longitudinal direction of the upper arm 14. In other words, the number of inflection points is eliminated or the curvature of the inflection points (that is, warping) is reduced.

  As shown in FIG. 1, the torch cable 30 is connected to the wire delivery port 24 via a welding power and shield gas receiving mechanism 25. Since the receiving mechanism 25 is well known, the description of its internal structure is omitted, but the receiving mechanism 25 is supplied with a power cable 26 for supplying power for welding and a shielding gas 33 (see FIG. 5A). A gas hose 27 is connected.

  As shown in FIG. 5 (a), a coil liner 32 is provided at the center of the torch cable 30 so that the welding wire 31 passes through it and guides its advancement and protects against wrinkles. The coil liner 32 functions as a conduit pipe. A hose 34 is provided so as to cover the outer periphery of the coil liner 32 and to form a shield gas passage between the outer periphery of the coil liner 32, and the shield gas 33 flows through the shield gas passage and is led to the welding torch. It is made to be. The outer periphery of the hose 34 is covered with a conductive wire 35, and the entire torch cable 30 is provided with an insulating coating 36. Further, as shown in FIG. 1, an insulating cover member 38 is covered on the base end portion of the torch cable 30. Examples of the cover member 38 include an insulating rubber boot or a plastic boot.

  Thus, the torch cable 30 is a one-wire power cable, and has a multiple structure so that the welding wire 31, power, and shielding gas 33 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 in FIG. 2B, an initial bend is given against the restoring force. The torch cable 30 is provided in the welding robot 10 independently of the motor drive system.

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 FIG. An outer race 42 of a roller bearing 41 is attached and fixed to the bearing case 40. The rotary shaft body 16 is configured by integrating an inner race 43 of a roller bearing 41 and a large-diameter pulley 44 with a bolt 45 at the base end of an arm member 29 of an upper arm 14. In this way, the rotating shaft body 16 is supported by the bearing case 40 provided on the tilting table 15.

  As shown in FIG. 2 (a), the rotary shaft body 16 is driven by a motor 46 provided on the tilting table 15, with a reduction gear 47, a small-diameter pulley 48 attached to its output shaft, and a timing belt 49 (FIG. 4 (a). )) And a large-diameter pulley 44 shown in FIG.

  In addition, the drive mechanism of the rotating shaft body 16 is not restricted to the said structure, For example, you may make it rotate the upper arm 14 in a well-known way via a hollow structure harmonic reducer (brand name).

  As shown in FIG. 2 (a), the arm member 29 is offset laterally from the rotation axis 14a, and a swing shaft 18 is provided at the tip thereof. As shown in FIG. 2 (b), the swing shaft 18 is provided. As a result, the torch support arm 17 is tilted. A torch support base 60 is provided at the tip of the torch support arm 17. Thus, the torch support base 60 has a cantilever support structure with respect to the torch support arm 17.

  The torch cable 30 passes through the side space 61 of the swing shaft 18 (fifth axis) along the rotation axis 14a from the upper arm 14 to the welding torch 19 (see FIG. 2B). Is arranged.

  As shown in FIG. 7C, when the elevation angle of the torch support arm 17 is large, the degree of curvature at the inflection point P of the torch cable 30 increases, and when the elevation angle of the torch support arm 17 decreases, FIG. As shown in b) and (c), the direction decreases. 2A, the swing shaft 18 includes a motor 62 provided on the arm member 29, an output shaft of the motor 62, pulleys 63 and 64 provided on the swing shaft 18, and both pulleys 63 and 64. It is driven via a belt 65 wound between them.

  The arm material 29 of the upper arm 14 is composed of one member formed to be shifted laterally from the rotation axis 14a as described above, but although not shown, for example, the arm material is composed of two parallel members. The torch cable 30 may be arranged in the opposite space. Further, the upper arm itself may be formed in a cylindrical shape so as to be transmitted through the inside thereof. In these cases, the torch support base 60 can have a double-sided structure. However, in this case, the torch cable 30 passes through the space above or below the swing shaft 18 (fifth shaft) and extends to the welding torch 19, so that the torch cable 18 (fifth shaft) and Considering this interference, a cantilever structure is desirable.

  As shown in FIG. 1, a guide cylinder 50 is supported by bearing means 51 so as to be free to rotate around the rotation axis 14a in the internal space SP of the rotary shaft body 16. Examples of the bearing means 51 include a roller bearing or a metal liner.

  A support member 52 is integrally provided at the inner peripheral tip of the guide tube 50. As shown in FIG. 1, the support member 52 is arranged so as to be perpendicular to the rotation axis 14a. The support member 52 is formed with an insertion hole 53 as a through hole through which the torch cable 30 passes through the rotation axis 14a so as to cross upward from below in the internal space SP. The entire opening of the insertion hole 53 is offset from the rotational axis 14 a of the upper arm 14. The insertion hole 53 is formed in a long hole so that the cross-sectional shape surrounds the rotation axis 14a, and when the guide cylinder 50 rotates around the rotation axis 14a, the torch cable 30 and the guide cylinder 50 are The torch cable 30 to be inserted is supported by the support member 52. The shape of the insertion hole 53 is not limited to the long hole. For example, if the diameter of the torch cable 30 is larger than that of the torch cable 30 and is formed in a fool hole, the cross-sectional shape may be circular or angular (for example, square). In short, the shape of the insertion hole 53 may be a size 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 53 is formed in this way, the stress accumulated in the torch cable 30 can be reduced even if the upper arm 14 and the support member 52 rotate relative to each other or do not rotate relative to each other.

  The torch cable 30 is linearly inserted into the insertion hole 53 from the end connected to the receiving mechanism 25, and in this state, as shown by a solid line in FIG. The torch cable 30 extends downward from the curved portion (that is, the inflection point P) and is connected to the welding torch 19. The insertion hole 53 allows the torch cable 30 to cross the rotation axis 14a from below to above in the internal space SP.

  As described above, the insertion hole 53 is formed so as to penetrate the torch cable 30 in the internal space SP so as to pass the rotation axis 14a so as to cross from below to above. Therefore, as shown in FIGS. 2B and 6, the inflection of the torch cable 30 starting from the support member 52 in a state where the torch cable 30 is bent downward by, for example, 90 degrees at the position of the swing shaft 18. Points can be eliminated, or warping is reduced as much as possible, and the burden on the torch cable 30 is reduced. This is clearly shown in FIG. It can be seen that the bend of the torch cable 30 is gentle when compared with the bend of the torch cable K passed through the rotation axis 14 a at the position of the support member 52.

  FIG. 6 shows a torch cable K indicated by a two-dot chain line as a conventional example. In the conventional example, the wire delivery port S of the wire feeding device and the base end side portion of the torch cable K are arranged in parallel to the rotation axis 14a. Then, the torch cable K that has passed through the support member extends upward (ie, warps) through the inflection point H1 of the curved portion, and extends downward through the inflection point H2 to connect to the welding torch 19. Is done.

On the other hand, in the present embodiment, unlike the conventional example, the number of inflection points can be reduced, or the warpage from the support member 52 can be reduced as much as possible.
Further, since the support member 52 is provided integrally with the guide tube 50, the guide tube 50 that rotates relative to the upper arm 14 prevents the torch cable 30 from being loosened or wobbled, and unnecessary deformation thereof is prevented. If the material of the guide tube 50 is a plastic molded product, the torch cable 30 can be insulated even though the insulating cover member 38 is covered. Further, since the support member 52 rotates freely together with the guide cylinder 50, the relative rotation of the torch cable 30 with respect to the upper arm 14 becomes even smoother.

  In addition to the insertion hole 53, the support member 52 is formed with insertion holes 54 and 55 at positions where the entire opening is offset from the rotation axis 14a of the upper arm 14, as shown in FIG. . The insertion holes 54 and 55 are defined by partitions 52a, 52b and 52c in which the guide cylinder 37 is arranged radially. A cooling hose 56 and a control cable 57 are inserted through the insertion holes 54 and 55. The cooling hose 56 is for supplying cooling water that absorbs welding heat. The control cable 57 is for giving a control signal to the motor 62 and the like for driving the joint.

(Operation of the embodiment)
Now, the installation method of the wire feeding device in the robot arm configured as described above, the installation structure of the wire feeding device, and the operation of the welding robot 10 will be described.

  FIGS. 7A to 7C show a state in which the lower arm 13 is standing in a vertical direction (see FIG. 3A) and the upper arm 14 is in a horizontal state, and the torch support arm 17 is in a horizontal state. The curved state of the torch cable 30 when the elevation angle is changed is shown. As shown in the figure, the degree of curvature at the inflection point P of the torch cable 30 is generally large in the state shown in FIG. 7C, and decreases as the elevation angle of the torch support arm 17 becomes smaller (FIG. 7A). ), See FIG. 7 (b)).

  In any of these states, the wire delivery port 24 is positioned below the rotation axis 14 a and is inclined obliquely upward with respect to the rotation axis 14 a, so that the wire feeding device 22 is connected to the tilting table 15. Is installed. And the torch cable 30 connected to the wire delivery port 24 is arrange | positioned so that it may cross | intersect the rotating shaft line 14a from the downward direction in the internal space SP of the rotating shaft body 16. FIG.

  As a result, unlike the conventional torch cable K shown by the two-dot chain line in FIG. 6, the torch cable 30 that has passed through the internal space SP does not have the inflection point H1 or warps from the support member 52. The rise can be reduced as much as possible. As a result, the feeding resistance of the welding wire 31 can be suppressed.

  8 (a) and 8 (c), the upper arm 14 swings up and down (in the direction of arrow C) around the third shaft 13a from the state of FIG. 8 (b) (same as FIG. 3 (b)). The state of the conduit pipe 39 when it is done is shown. In general, the wire reel 69 is often placed at a position below the wire feeder 22 as shown in FIG. Alternatively, the conduit pipe 39 connected to a wire reel (not shown) may be connected to the wire feeding device 22 in a state of being supported by being suspended as indicated by a one-dot chain line in FIG. In this case, the conduit pipe 39 is bent downwardly before the wire feeding device 22 is connected so as to have a margin so as not to interfere with the operation of the welding robot 10.

  As shown in FIG. 8B, in the present embodiment, the wire feeding device 22 is attached and fixed to a mounting surface 15a that is provided obliquely upward with respect to the upper arm 14 side. For this reason, even if the upper arm 14 is swung around the third shaft 13a (see FIG. 3A), the radius of curvature of the curved portion W of the conduit pipe 39 can be made larger than before.

  Here, the conventional case will be described. Conventionally, the wire feeding device 22 is not the mounting surface 15a provided so as to be obliquely upward with respect to the upper arm 14 side, but the state shown in FIG. 3A (the lower arm 13 stands along the vertical direction). In the standing state), it was provided on the horizontal mounting surface. For this reason, in the conventional wire feeder 22a, if the wire reel 69 is disposed at the same position as the present embodiment (a position below the wire feeder 22), the conventional wire feeder 22a The radius of curvature of the connected conduit pipe 39a is reduced (see FIGS. 8A and 8C). 8A to 8C, the state of the conventional conduit pipe 39a is indicated by a two-dot chain line. FIG. 9B shows a case where the lower arm 13 is tilted forward by the second shaft 12a from the state of FIG. 9A.

  In FIG. 9B, when the wire reel 69 is placed at a position below the wire feeding device 22, the conduit pipe 39 of this embodiment is shown by a solid line, and the conventional conduit pipe 39a is It is indicated by a two-dot chain line.

  In FIG. 9B, when the conduit pipe 39 connected to a wire reel (not shown) is suspended and supported, the conduit pipe 39 of the present embodiment is shown by a one-dot chain line. 39b is indicated by a dotted line.

  In both cases where the wire reel 69 is placed at a position below the wire feeding device 22 and the conduit pipe 39 is supported in a suspended state, the bending portion W of the conduit pipe 39 The radius of curvature can be made larger than before. Thus, since this embodiment can secure a larger radius of curvature of the curved portion W of the conduit pipe 39, the feeding resistance of the welding wire 31 can be reduced and stable welding wire feeding can be achieved. For this reason, welding quality can be improved. Now, according to the first embodiment, there are the following features.

  (1) The installation method of the present embodiment is such that the wire delivery port 24 of the wire feeding device 22 is positioned below the rotation axis 14a of the upper arm 14 so that the wire feed port 22 faces obliquely upward with respect to the rotation axis 14a. In the internal space SP of the torch cable 30 connected to the outlet 24, the wire feeder 22 is installed so as to cross the rotation axis 14a from below to above.

  For this reason, the inflection point of the torch cable arranged from the wire feeder 22 to the welding torch 19 through the internal space SP of the upper arm 14 can be reduced, or the warpage from the support member can be minimized. It is possible to reduce the feeding resistance of the welding wire 31 and suppress adverse effects on welding.

  In either case where the wire reel 69 is placed at a position below the wire feeding device 22 or the conduit pipe 39 is suspended and supported, the curved portion W of the conduit pipe 39 is provided. The radius of curvature can be made larger than before. For this reason, since the curvature radius of the curved part W of the conduit pipe 39 can be ensured large, the feeding resistance of the welding wire 31 can be reduced, the stable welding wire can be fed, and the welding quality can be improved.

  (2) The installation structure of this embodiment is such that the wire delivery port 24 of the wire feeding device 22 is positioned below the rotation axis 14a of the upper arm 14 and is directed obliquely upward with respect to the rotation axis 14a. A wire feeding device 22 is installed on a tilting table 15 that supports the shaft 14 so as to be rotatable around a rotation axis 14a. And the torch cable 30 connected to the wire delivery port 24 is arrange | positioned so that it may cross | intersect the rotating shaft line 14a from the downward direction in the interior space SP. For this reason, according to this installation structure, the inflection point of the torch cable 30 arranged from the wire feeding device 22 to the welding torch 19 through the internal space SP of the upper arm 14 can be reduced, or from the support member. It is possible to reduce the warping as much as possible, reduce the feeding resistance of the welding wire 31, and suppress adverse effects on welding.

  (3) In the installation structure of this embodiment, in the internal space SP of the upper arm 14, a support member 52 is provided on the rotary shaft body 16 positioned at the base end portion of the upper arm 14, and the torch cable 30 is provided on the support member 52. An insertion hole 53 that allows the torch cable 30 to cross the rotation axis 14a from below to above in the internal space SP is formed. As a result, by passing the torch cable 30 through the insertion hole 53 of the support member 52, the torch cable 30 can be allowed to cross the rotation axis 14a from below to above, and the torch cable 30 can be allowed to pass through the internal space SP. It can be in a straight line state.

  (4) In the installation structure of the present embodiment, the support member 52 is provided in the guide cylinder 50 that is supported so as to be freely rotatable in the rotary shaft body 16. For this reason, the guide tube 50 that rotates relative to the upper arm 14 prevents the torch cable 30 from loosening and wobbling, so that unnecessary deformation of the torch cable 30 can be prevented. Further, since the support member 52 rotates together with the guide tube 50, the relative rotation of the torch cable 30 with respect to the upper arm 14 can be made smoother.

  (5) In the installation structure of the present embodiment, the torch cable 30 is composed of a one-wire power cable. For this reason, what is essential for arc welding, such as welding wire 31, welding power, and welding shield gas, can be supplied to the welding torch via a single cable.

  (6) The welding robot 10 of this embodiment is provided with the installation structure of the wire feeder as described in said (1)-(5). As a result, the welding robot 10 of the present embodiment exhibits the effects (1) to (5) more remarkably as a welding robot.

  (7) The welding robot 10 of this embodiment is configured as an articulated arc welding robot. As a result, the effects (1) to (5) are more remarkably exhibited in the articulated arc welding robot.

  (8) In the welding robot 10 of this embodiment, the rotating shaft body 16 (rotating shaft) and the swing shaft 18 are the fourth axis and the fifth axis in the six-axis manipulator. As a result, the influence of the continued bending of the torch cable 30 on the swing shaft 18 (fifth axis) and the repeated bending operation on the torch cable 30 on the upstream side reaching the rotating shaft body 16 (fourth axis) is as much as possible. To less. Further, the operation range of the welding torch 19 is increased and the operation speed is increased, and the feedability of the welding wire 31 is enhanced to achieve high quality welding, and the conduit pipe 39 connected to the wire feeding device 22 is provided. Durability can also be improved.

(Second Embodiment)
Next, a second embodiment will be described with reference to FIG. Note that the same components as those in the first embodiment are denoted by the same reference numerals, description thereof will be omitted, and components different from those in the first embodiment will be mainly described.

  In the second embodiment, a flange 50a is formed in the guide tube 50 instead of omitting the bearing means 51 in the configuration of the first embodiment, and the inner race 43 and pulley 44 of the roller bearing 41 are formed at the base end of the arm member 29. The flange 50a is integrated with the bolt 45 so that the guide tube 50 is fixed to the rotary shaft body 16.

  And this embodiment differs from 1st Embodiment that the partition 52c between the insertion holes 54 and 55 of 1st Embodiment is abbreviate | omitted, and the insertion hole 58 is formed (FIG.14 (c)). )reference).

  14A and 14B, the elongated hole shape of the insertion hole 53 may be an inverted U-shape or a horseshoe shape, and the torch cable 30 can move relatively in the direction of the arrow. It only has to be like this. In FIGS. 14A and 14B, the insertion holes 54 and 55 are omitted for convenience of explanation.

  Thus, in this embodiment, when the upper arm 14 rotates around the rotation axis 14 a, relative movement around the rotation axis 14 a of the torch cable 30 is allowed in the insertion hole 53.

The features of the second embodiment are as follows.
(1) In the present embodiment, the insertion hole 53 is formed in a long hole formed so as to surround the rotation axis 14 a, and when the upper arm 14 rotates around the rotation axis 14 a, the torch is inserted in the insertion hole 53. The cable 30 is allowed to move around the rotation axis 14a.

  As a result, when the upper arm 14 rotates around the rotation axis 14 a, the guide tube 50 and the support member 52 are rotated together, and relative movement around the rotation axis 14 a of the torch cable 30 is allowed in the insertion hole 53. Thus, the torch cable 30 maintains a state where it intersects the rotation axis 14a from below to above. Further, since the insertion hole 53 is formed in an arc-shaped long hole so as to surround the rotation axis 14a, the relative movement of the torch cable 30 which is to be pulled by twisting when the upper arm 14 is rotated. Allow as close to free state as possible. For this reason, the influence of the rotation of the upper arm 14 can be prevented from affecting the torch cable 30. As a result, the stress accumulated in the torch cable 30 can be reduced or released.

In addition, embodiment of this invention is not limited to said each embodiment, It can also be comprised as follows.
As shown in FIG. 5B, the insertion hole 58 of the support member 52 is formed between the partitions 52 a and 52 b, the control cable 57 is inserted, and the cooling hose 56 is inserted into the insertion hole 53. You may let them.

  In each of the embodiments, the support member 52 is brought closer to one end of the guide tube 50, and the thickness of the support member 52 is drawn to be shorter than the length of the guide tube 50 in the longitudinal direction. For example, the guide tube 50 may extend over the entire length. In that case, the torch cable 30 and the control cable 57 can be electrically and reliably isolated at least in the guide tube 50. Even if the torch cable 30 is damaged, the noise generated from the torch cable 30 can be prevented from reaching the control cable 57 at least in the guide tube.

  Further, for example, the support member 52 may be provided not at the full length of the guide tube 50 but at the central portion in the longitudinal direction of the guide tube 50 or at a position closer to the wire delivery port 24 side than the central portion in the longitudinal direction. In this case, the position of the insertion hole 53 is provided in the internal space SP so as not to prevent the torch cable 30 from obliquely upward with respect to the rotation axis 14a and crossing the rotation axis 14a from below to above. Just do it.

  In the second embodiment, the guide cylinder 50 is fixed with respect to the rotary shaft body 16, but in the configuration of the second embodiment, the guide cylinder is omitted and the support member 52 is free from the rotary shaft body 16. It cannot be rolled, that is, it may be fixed.

  Further, when the support member 52 and the guide cylinder 50 are not idle, the rotary shaft body 16 does not need to be cylindrical. For example, as shown in FIG. 11, the rotary shaft 16 may have a semi-cylindrical shape, and the support member 52 may be integrated at the front end thereof. Alternatively, the rotary shaft body 16 itself may be a disk that also serves as the support member 52. Any one of the actions described above may be realized.

  The support member 52 having the insertion hole 53 (not shown) may be supported so as to be freely rotatable with respect to the rotating shaft body 16 without using the guide tube described above. Even in this case, the torch cable 30 can be kept insensitive to the rotation of the upper arm 14.

  In the configuration of the first embodiment, the support member 52 may be supported so as to be freely rotatable with respect to the guide tube 50. Since the guide tube 50 is free to rotate with respect to the rotating shaft body 16 and the support member 52 is free to rotate with respect to the guide tube 50, the torch cable is not affected by the rotation of the upper arm 14 even in this case. 30 can be left insensitive.

  In the configuration of the first embodiment, instead of fixing the wire feeding device 22 to the mounting surface 15 a of the tilting table 15, the wire feeding device 22 may be rotatably attached to the mounting surface 15 a. For example, in the illustration of FIG. 12, the rotation shaft 68 protruding from the lower surface of the apparatus main body case 23 of the wire feeding device 22 is rotatable by a bearing 67 provided below the placement surface 15a.

  In this case, the insertion hole 53 has a long hole shape as shown in FIGS. With this configuration, when the upper arm 14 rotates around the rotation axis 14 a, the movement of the torch cable 30 around the rotation axis 14 a is permitted in the insertion hole 53. The torch cable 30 may move by friction following the movement. At this time, even if the torch cable 30 is displaced, the apparatus main body case 23 is rotated according to the displacement. FIG. 13 shows an example in which the wire feeding device 22 is rotated by an angle θ about the rotation shaft 68. For this reason, the influence of the rotation of the upper arm 14 can be prevented from affecting the torch cable 30. As a result, the stress accumulated in the torch cable 30 can be reduced or released.

  In addition, if the wire feeding device 22 is provided on the mounting surface 15a so as to be rotatable by the rotation shaft 68, the mounting accuracy becomes stricter, unlike the case where the wire feeding device 22 is fixed to the mounting surface 15a of the device body case 23. There is no need, and the wire feeder 22 can be easily attached to the mounting surface 15a.

FIG. 3 is a structural diagram of an upper arm portion showing an installation structure of a wire feeding device in the robot arm according to the first embodiment embodying the present invention. (A) And (b) is the top view and front view in the upper half part of an articulated arc welding robot. (A) And (b) is the whole figure of an articulated type arc welding robot, and the front view drawn by omitting the welding torch. (A) And (b) is the rear view and top view which mainly represented the upper arm. (A) And (b) is an expansion perspective view of the supporting member which supports a cable etc. FIG. The comparison figure of the bending shape which will be given to a torch cable. (A)-(c) is explanatory drawing of the bending shape given to a torch cable. (A)-(c) is explanatory drawing of the bending shape given to the conduit cable connected to the wire feeder. (A), (b) is a schematic explanatory drawing of the shape of the conduit pipe connected to the wire reel. The structure diagram of the upper arm part showing the installation structure of the wire feeding apparatus in the robot arm which concerns on other embodiment. The perspective view of an upper arm when a rotating shaft body is not cylindrical. The structure diagram of the upper arm part showing the installation structure of the wire feeding apparatus in the robot arm which concerns on other embodiment. The schematic plan view of the state which the wire feeder in the robot arm which concerns on other embodiment rotated. (A)-(c) is explanatory drawing of the shape of the penetration hole 53. FIG.

Explanation of symbols

10 ... Welding robot, 13 ... Lower arm, 13a ... Third axis,
14 ... Upper arm (rotating arm), 14a ... Rotating axis (longitudinal axis),
15 ... tilting table (support), 15a ... placement surface, 16 ... rotating shaft (fourth axis),
17 ... torch support arm (end effector), 18 ... swing axis (fifth axis),
DESCRIPTION OF SYMBOLS 19 ... Welding torch, 22 ... Wire feeder, 23 ... Apparatus main body case 24 ... Wire delivery port (wire exit), 24a ... Center axis line,
30 ... Torch cable, 31 ... Welding wire, 39 ... Conduit pipe,
50 ... guide tube, 52 ... support member, 53 ... insertion hole (through hole),
SP ... internal space, P ... inflection point.

Claims (11)

A rotary arm provided with a joint provided with a rocking shaft for rocking the end effector at the distal end and a joint provided with a rotation shaft around the longitudinal axis at the proximal end;
A torch cable that passes through the internal space of the rotary arm and extends to a welding torch provided in a welding torch provided in the end effector, and allows a welding wire to pass through;
In the method of installing the wire feeding device in the welding robot, which is disposed on the base end side of the rotating arm and includes a wire feeding device that applies feeding to the welding wire.
The torch cable connected to the wire outlet so that the wire outlet of the wire feeder is located below the longitudinal axis of the rotating arm and is obliquely upward with respect to the longitudinal axis. However, in the internal space, the wire feeding device is installed so as to cross the longitudinal axis from below to above. A rotary arm provided with a joint provided with a rocking shaft for rocking the end effector at the distal end and a joint provided with a rotation shaft around the longitudinal axis at the proximal end;
A torch cable that passes through the internal space of the rotating arm and extends to a welding torch provided in the end effector, and allows a welding wire to pass through;
In the installation structure of the wire feeding device in the welding robot, which is disposed on the base end side of the rotating arm and includes a wire feeding device that applies feeding to the welding wire,
The wire arm of the wire feeder is positioned below the longitudinal axis of the rotary arm and is rotated about the longitudinal axis so that the wire outlet is obliquely upward with respect to the longitudinal axis. The wire feeding device is installed on a support that is movably supported,
An installation structure of a wire feeding device in a welding robot, wherein the torch cable connected to the wire outlet is arranged in the internal space so as to cross the longitudinal axis from below to above.   In the internal space of the rotating arm, a rotating shaft body positioned at the base end of the rotating arm is provided as the rotating shaft and a supporting member is provided on the rotating shaft body, and the torch cable is provided on the supporting member. 3. The wire feed in the welding robot according to claim 2, wherein a through-hole is formed in the inner space so as to allow the torch cable to cross the longitudinal axis from below to above in the internal space. Feeder installation structure. The through hole is a long hole formed around the longitudinal axis,
The wire feeding device according to claim 3, wherein when the rotating arm rotates around the longitudinal axis, movement of the torch cable around the longitudinal axis within the through hole is allowed. Installation structure.   The installation structure of the wire feeding device in the welding robot according to claim 4, wherein the support member is supported so as to be freely rotatable in the rotating shaft.   The installation structure of the wire feeding device in the welding robot according to claim 3 or 4, wherein the support member is provided on a guide cylinder supported so as to be freely rotatable in the rotary shaft.   The wire feeding device is swingably supported with respect to the support body so as to follow the movement of the torch cable supported by the support member when the support member is idle. The installation structure of the wire feeding device in the welding robot according to claim 5 or 6,   The installation structure of the wire feeding device in the welding robot according to claim 2, wherein the torch cable is a one-wire power cable.   A welding robot comprising the installation structure of the wire feeding device according to any one of claims 2 to 8.   The welding robot according to claim 9, wherein the welding robot is an articulated arc welding robot.   The welding robot according to claim 10, wherein the rotation axis and the swing axis are a fourth axis and a fifth axis in a six-axis manipulator.

Images