JP2010052021A - Buffer forming mechanism for wire, wire feeding device and welding/thermal spraying robot - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a buffer forming mechanism for a wire which provides a sufficient wire slack amount, and can be installed even in the vicinity of a torch for welding/thermal spraying in an articulated arm welding robot or the like. <P>SOLUTION: The buffer forming mechanism a2 includes: a wire tube 2 in which wire w introduced from a wire introduction edge 21 and passed through the inside is fed-out from a feeding-out edge 22; and a support base 1. The wire introduction edge 21 is fixed to the support base 1, the wire feeding-out edge 22 is supported relatively movably in the axial direction with respect o the support base 1, and the wire tube 2 forms a loop in such a manner that the wire introduction edge 21 and the wire feeding-out edge 22 face directions reverse to each other. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a wire buffer forming mechanism, a wire supply device, and a welding / spraying robot, and in the welding / spraying robot or the like, the welding / spraying wire fed out from a wire reel is responsive to a welding / spraying torch tip. It relates to technology to supply well.

  In general, a welding / spraying apparatus in which a wire is used as a welding material or a spraying material is configured to supply a wire fed from a wire reel wound with a large amount of wire to the tip of the torch via the wire supply device.

  The wire supply device includes a push roller that pushes a wire fed from a wire reel toward the tip, a pull roller that sends the wire toward the tip in the vicinity of the torch, and a buffer disposed between the push roller and the pull roller. And a forming part. The buffer forming unit forms a slack in the wire between the push roller and the pull roller. Both the push roller and the pull roller are driven and controlled by the control means. However, when the wire feeding amount by the push roller is larger than the wire feeding amount by the pull roller, the amount of slackness of the wire in the buffer forming portion increases and vice versa. In addition, when the wire feed amount by the pull roller is larger than the wire feed amount by the push roller, the slack amount of the wire in the buffer forming portion decreases. The pull roller controls the supply and stop of the wire to the welding / spraying region in the vicinity of the torch. However, since the wire is slack in the buffer forming portion as described above, the push roller is temporarily stopped. However, by reducing the amount of looseness of the wire, it is possible to supply a wire with good response without slipping even when the driving force of the pull roller is small. The amount of slack of the wire in the buffer forming unit is constantly monitored, and when the amount of slack of the wire falls below a predetermined value, the push roller is driven to control the amount of slack of the wire in the buffer forming unit to be constant. The

  As a device having a function equivalent to that of the above-described wire buffer forming portion, a welding wire storage device disclosed in Patent Document 1 is conventionally known. As shown in FIG. 7 of the present application, the welding wire storage device is configured so that the direction of the wire introduction portion 91 and the direction of the wire delivery portion 92 are substantially perpendicular to each other, and a housing having a crescent-shaped internal space. The wire from the wire introduction part 91 to the wire delivery part 92 lies in a curved shape with a slack in the internal space. Even in such a configuration, as long as the wire does not contact the inner wall of the crescent-shaped internal space, the wire can be sent from the wire sending unit 92 with a small driving force by reducing the amount of slack. . In the welding wire storage device shown in the same document 1, the amount of wire slack in the housing is detected, and the wire is introduced from the wire introducing portion 91 so that the amount of wire slack is constant.

  However, the welding wire storage device disclosed in Patent Document 1 has the following problems.

  First, since the slack of the wire is formed only within the range allowed by the width of the crescent-shaped space in the housing, it is difficult to ensure a certain amount of slack of the wire. Therefore, it becomes difficult to cope with the case where the wire must be supplied from the torch at a high speed.

  Secondly, since the directions of the wire introduction part 91 and the wire delivery part 92 are converted to make a right angle, the welding wire storage device is mounted on a movable arm in the vicinity of the torch in the welding robot, for example. It becomes difficult to arrange in the vicinity. That is, when the direction of the wire delivery portion 92 is directed to the direction of the torch, the direction of the wire introduction portion 91 is directed to the lateral direction at a right angle. A wire fed from a wire reel is introduced into the wire introducing portion 91. However, in the case of an articulated arm type robot, it is difficult to route the wire along the arm. For this reason, the welding wire storage device must be installed on a fixed member other than the movable arm. If it does so, the distance from the wire sending part 92 to a welding torch will become long, and it will become difficult to supply a wire with sufficient responsiveness from a torch.

Special table 2007-518568 gazette

  The present invention has been conceived under the circumstances described above, and can obtain a sufficient amount of wire slack, and is also installed near a welding / spraying torch in an articulated arm type welding robot or the like. It is a main object to provide a wire buffer forming mechanism that can be used.

  The wire buffer forming mechanism provided by the first aspect of the present invention has a wire introduction end and a wire delivery end, and the wire introduced from the wire introduction end and passed through the wire introduction end is connected to the wire delivery end. A tube-shaped wire guide to be delivered; and a support base for supporting the wire guide. The wire introduction end is fixed to the support base, and the wire delivery end is fixed to the support base. The wire guide is supported so as to be relatively movable in the axial direction, and the wire guide is looped so that the wire introduction end and the wire delivery end face in opposite directions.

  In a preferred embodiment, when viewed from the direction perpendicular to the plane including the loop, the angle between the axes of the wire introduction end and the wire delivery end is in the range of 160 ° to 200 °.

  In a more preferred embodiment, the wire introduction end and the wire delivery end are positioned on the same straight line when viewed from a direction perpendicular to the plane including the loop.

  In a preferred embodiment, the apparatus further includes detection means for detecting a relative position of the wire delivery end with respect to the support base.

  In a preferred embodiment, the detection means further includes an arm that rotates with the tip engaged with the wire guide in the vicinity of the wire delivery end, and a rotary encoder that detects the rotation of the arm.

  The wire supply device provided by the second aspect of the present invention is a wire supply device including a wire buffer forming mechanism according to the first aspect, and a wire from which a wire introduced into the wire introduction end is drawn out. A reel, a wire push means for pushing the wire fed out from the wire reel toward the wire introduction end, a wire pull means for pulling the wire delivered from the wire delivery end, and a control means, further comprising: The control means controls the pushing of the wire by the wire push means so that the position of the wire delivery end detected by the detection means becomes a reference position.

  The welding / spraying robot provided by the third aspect of the present invention is equipped with the wire supply device according to the second aspect, and the welding / spraying torch is supported on the base via an articulated arm. A welding / spraying robot for performing welding or spraying by supplying a wire fed from a wire reel from the welding / spraying torch, wherein the wire buffer forming mechanism is mounted on any one of the articulated arms. The wire delivered from the wire delivery end is supplied to the welding / spraying torch.

  Any aspect of the present invention includes a wire buffering mechanism. The wire guide in the wire buffer forming mechanism forms a loop so that the wire introduction end and the wire delivery end face in opposite directions. Therefore, this loop forms a substantially closed circle, and the amount of slackness of the wire to be formed can be sufficient.

  Furthermore, since the wire introduction end and the wire delivery end of the wire guide are opposite to each other, the wire buffer forming mechanism arranges the axis of the wire introduction end and the axis of the wire delivery end on substantially the same straight line. can do. This means that the wire extending to the wire introduction end and the wire extending from the wire delivery end to the torch can be arranged in a direction having a series without being bent. Therefore, even when this wire buffer forming mechanism is installed on an arm near the torch in an articulated arm type welding robot, the wire reaching the wire introduction end and the wire sent from the wire delivery end are Can be handled without any inconvenience.

  Then, the amount of wire from the wire buffer forming mechanism to the torch is reduced, and the friction between the wire guide member and the member that guides the wire between them is reduced, and the wire supply from the torch by the wire pull means is performed without slipping and with good responsiveness. Is possible.

  Other features and advantages of the present invention will become more apparent from the detailed description given below with reference to the drawings.

  Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.

  FIG. 1 is a schematic view of a welding robot R according to the first embodiment of the present invention. This welding robot R is an articulated arm type welding robot, and is connected to a first arm r1 rotatably connected to the base r0 and to the first arm r1. The second arm r2 and the torch support member r3 rotatably connected to the second arm r2 are provided. Regarding the configuration of the articulated arm and the support mechanism of the torch support member r3, Not limited to this. The multi-joint welding robot R can guide the welding torch t in a predetermined direction and posture along a three-dimensional welding path.

  A welding torch t is supported on the torch support member r3. The welding torch t includes a torch body t1 and a wire delivery nozzle t2, and a pull roller p2 for delivering the wire toward the wire delivery nozzle t2 is provided inside the torch body t1. The pull roller p2 corresponds to an example of a wire pull unit in the present invention. Although not shown, this welding torch t incorporates a known mechanism for injecting an inert gas so as to surround the welding site and supplying a welding current to the wire.

  The supply of the wire to the welding torch t is performed by the wire supply device A1 that supplies the wire fed from the wire reel a1. The wire supply device A1 loosens the wire reel a1, the push roller p1 that pushes and feeds the wire fed out from the wire reel a1, and the wire between the push roller p1 and the pull roller p2 in the torch body t1. And a wire buffer forming mechanism a2 for forming. Even if the position of the welding torch t with respect to the wire reel a1 changes variously, from push roller p1 to pull roller p2 in order to realize wire push feed by push roller p1 and wire pull feed by pull roller p2. The wire between the wires is inserted into a wire guide tube a3 that basically does not expand and contract and is at least partially flexible. The push roller p1 corresponds to an example of a wire push means in the present invention.

  FIG. 2 is a side view of the main part of the buffer forming mechanism a2. FIG. 3 is a top view of the main part of the buffer forming mechanism a2. The buffer forming mechanism a2 includes a support base 1 and a tube-shaped wire guide wg supported by the support base 1. The wire guide wg includes a wire introduction end 21 to which the wire w is introduced and a wire delivery end 22 to which the wire is delivered. In this embodiment, the wire tube 2 having flexibility and the delivery end 22 side are provided. And a pipe member 3 connected to the wire tube 2. The wire tube 2 is inserted in a fixed manner into an attachment tube 51 penetrating and held in an appropriate portion of the support base 1 on the wire introduction end 21 side. On the other hand, the pipe member 3 is inserted into a cylindrical guide member 52 that is penetrated and held in an appropriate portion of the support base 1 so as to be relatively movable in the axial direction. A wire guide tube a3 is inserted into the mounting cylinder 51 and inserted through the wire w fed from the wire reel a1 and fed out by the push roller p1, and the wire w reaching the pull roller p2 of the welding torch t is connected to the cylindrical guide member 52. The wire guide tube a3 which penetrates is connected. In this way, the wire w is inserted into the wire guide tube a3 on the push roller p1 side, the tube-shaped wire guide wg in the buffer forming mechanism a2, or the wire guide tube a3 on the pull roller p2 side in series and fed. .

  As clearly shown in FIG. 2, the tube-shaped wire guide wg is routed so that the intermediate portion of the flexible wire tube 2 forms a circular loop of one round. In this embodiment, as clearly shown in FIG. 2, the wire introduction end 21 of the tubular wire guide wg and the wire delivery end 22 are directed in opposite directions, and the axis of the wire introduction end 21 is That is, the axis of the mounting cylinder 51 and the axis of the wire delivery end 22, that is, the axis of the cylindrical guide member 52 or the pipe member 3 lie on the same straight line when viewed from the direction perpendicular to the plane including the loop. Has been made.

  In the above configuration, when the pipe member 3 is moving in the Xa direction in FIG. 2, compared to the state in which the pipe member 3 is moving in the Xb direction in FIG. In the state where the length of the wire w inserted through to 52 is shortened and the pipe member 3 is moving in the Xb direction of FIG. 2, the pipe member 3 is moving in the Xa direction of FIG. Compared to the state, the length of the wire w inserted between the attachment cylinder 51 and the cylindrical guide member 52 becomes longer. This is because the change in the buffer amount (slack amount) of the wire w formed in the buffer forming mechanism a2 is a change in the position in the Xa-Xb direction of the pipe member 3 located at the wire delivery end 22 of the tubular wire guide wg. Means that

  The support base 1 is also provided with detection means 6 for detecting a change in the position of the pipe member 3 in the Xa-Xb direction. In the present embodiment, the detection means 6 includes a rotary encoder (not shown) for detecting the rotation amount of the shaft 61, a proximal end attached to the shaft 61, extending in the radial direction of the shaft 61, and a distal end attached to the pipe member 3. And an engaging detection arm 62. The distal end 62a of the detection arm 62 has a bifurcated fork shape as shown in FIG. 4, and the distal end 62a is engaged with a small-diameter engaging portion 33 formed on the outer periphery of the pipe member 3. Match. Thereby, the position change of the pipe member 3 in the Xa-Xb direction is detected as the rotation amount of the shaft 61 of the rotary encoder, and the detected information is output to the control means (not shown).

  FIG. 5 is a flowchart showing the processing procedure of the means for controlling the wire feed by the push roller p1. In this control means, processing is performed in the following procedure.

  First, it is determined whether or not a signal for turning off the control means is input (S101). When the signal for turning off the control means is input (S101: Yes), the flow of the control means is ended. When the signal for turning off the control means is not input (S101: No), the control means determines the position of the wire delivery end 22 from the predetermined reference position in the Xa direction of FIG. 2 with respect to the reference position. It is determined whether or not the displacement is 0 (S102). When this displacement is 0 (S102: Yes), the control means does not output a signal for increasing or decreasing the wire feeding speed to the push roller p1 (S103).

  On the other hand, when the displacement is not 0 (S102: No), the control means determines whether or not the displacement is positive (a state displaced in the Xa direction in FIG. 2 with respect to the reference position) ( S104). If this displacement is positive (S104: Yes), the control means outputs a signal for increasing the wire feed speed to the push roller p1 (S105). That is, when it is determined that the slack amount of the wire w in the buffer forming mechanism a2 is smaller than the predetermined amount, the wire w feeding speed by the push roller p1 is increased. Thereby, the amount of looseness of the wire w in the buffer forming mechanism a2 is increased. On the other hand, if the displacement is negative (displaced in the Xb direction of FIG. 2 with respect to the reference position) (S104: No), the control means decreases the wire feed speed to the push roller p1. A signal for output is output (S106). That is, when it is determined that the amount of slack of the wire w in the buffer forming mechanism a2 is larger than a predetermined amount, processing for reducing the wire w feeding speed by the push roller p1 is performed. As a result, the slack amount of the wire w in the buffer forming mechanism a2 is reduced. Thereafter, the control means repeats the same process.

  Through the above processing, it is possible to always maintain a certain amount of wire slack in the buffer forming mechanism a2. As a result, the wire feeding in the welding robot R shown in FIG. 1 is performed smoothly.

  Next, the operation of the wire buffer forming mechanism a2, the wire supply device A2, and the welding robot R according to the present embodiment will be described.

  In the present embodiment, the wire tube 2 forms a loop so that the wire introduction end 21 and the wire delivery end 22 face in opposite directions. Therefore, this loop forms a substantially closed circle, and the amount of slackness of the wire w to be formed can be sufficient.

  Further, in the buffer forming mechanism a2, the wire introduction end 21 and the wire delivery end 22 are opposite to each other, so that the axis of the wire introduction end 21 and the axis of the wire delivery end 22 are substantially on the same straight line. Can be arranged. This means that the wire w extending to the wire introduction end 21 and the wire w extending from the wire delivery end 22 to the welding torch t can be arranged in a direction having a series without being bent. Therefore, even if the buffer forming mechanism a2 is equipped on the second arm r2 in the vicinity of the welding torch t, the wire w reaching the wire introduction end 21 and the wire w delivered from the wire delivery end 21 are second It can be handled without any inconvenience as it is along the arm r2.

  Then, the amount of the wire w from the wire buffer forming mechanism a2 to the welding torch t is reduced, and the friction with the guide tube a3 that guides the wire w during this period is also reduced. Wire supply can be performed with good responsiveness without slipping.

  In this embodiment, the slack amount of the wire w in the buffer forming mechanism a2 is detected as the displacement of the wire sending end 22 with respect to a predetermined reference position. This displacement is in the Xa-Xb direction. Therefore, the amount of slackness of the wire can be measured more accurately as compared with the case where the amount of slackness of the wire w is measured by measuring the loop diameter of the wire tube 2.

  FIG. 6 shows a schematic diagram of a welding robot R according to the second embodiment of the present invention. In this figure, elements that are the same as or similar to those in the above embodiment are given the same reference numerals as in the above embodiment.

  Here, in the wire supply device A2, the push roller p1 and the buffer forming mechanism a4 are connected while being close to each other. While the push roller p1 is mounted on the second arm r2, the position of the tubular wire guide wg in the buffer forming mechanism a4 is made closer to the welding torch t by changing the form of the support base 1. A mechanism in which the push roller p1 and the buffer forming mechanism a4 are connected is mounted on the second arm r2. Also in the present embodiment, in the buffer forming mechanism a4, the wire introduction end 21 and the wire delivery end 22 face in opposite directions. The angle formed by the axes of the wire introduction end 21 and the wire delivery end 22 is about 160 °. According to such a configuration, the wire length between the welding torch t and the buffer forming mechanism a4 is shorter. Therefore, the friction between the wire guide tube a3 and the wire w is reduced. As a result, the wire w can be fed with higher responsiveness.

  The scope of the present invention is not limited to the embodiment described above. The specific configuration of each part of the wire buffer forming mechanism, the wire supply device, and the welding robot according to the present invention can be varied in design in various ways.

  The angle formed by the axis of the wire introduction end 21 and the wire delivery end 22 of the tubular wire guide wg is 180 ° in the first embodiment (FIGS. 1 to 3) (the axes are located on the same straight line). On the other hand, in the second embodiment (FIG. 6), it is about 160 °, but if it is within the range of 160 ° to 200 °, the wire introduction end 21 and the wire delivery end 22 face in opposite directions. The advantage by this can be fully exhibited.

  Moreover, although the present invention is applied to the welding robot in the above-described embodiment, it is needless to say that the present invention can also be applied to a thermal spray robot using a wire as a thermal spray material.

It is the schematic of the welding robot concerning 1st Embodiment. It is a principal part side view of the buffer formation mechanism concerning 1st Embodiment. FIG. 3 is a top view of the main part of the buffer forming mechanism described in FIG. 2. FIG. 4 is a cross-sectional view of a pipe material taken along line IV-IV in FIG. 2. It is a flowchart in the control means which controls the wire feed of the push roller concerning 1st Embodiment. It is the schematic of the welding robot concerning 2nd Embodiment. It is a principal part side view of the conventional welding wire storage apparatus (buffer formation mechanism).

Explanation of symbols

R welding robot r0 base r1, r2 arm r3 torch support member t welding torch t1 torch body t2 wire feed nozzle p1 push roller p2 pull roller A1, A2 wire supply device a1, wire reel a2, a4 buffer forming mechanism a3 tube 1 support base wg wire Guide 2 Wire tube 21 Introducing end 22 Sending end 3 Pipe member 33 Engaging portion 51 Mounting cylinder 52 Cylindrical guide member 6 Detection means 61 Axis 62 Detection arms Xa, Xb Direction w Wire

Claims (7)

A tube-shaped wire guide having a wire introduction end and a wire delivery end, in which a wire introduced from the wire introduction end and passed through the inside is delivered from the wire delivery end, and a support base for supporting the wire guide And
The wire introduction end is fixed to the support base, and the wire delivery end is supported so as to be movable relative to the support base in the axial direction.
A wire buffer forming mechanism, wherein the wire guide has a loop so that the wire introduction end and the wire delivery end face in opposite directions.   The angle formed by the axes of the wire introduction end and the wire delivery end when viewed from a direction perpendicular to the plane including the loop is in a range of 160 ° to 200 °. Wire buffer formation mechanism.   The wire buffer forming mechanism according to claim 2, wherein the wire introduction end and the wire delivery end are positioned on the same straight line when viewed from a direction perpendicular to the plane including the loop.   The wire buffer forming mechanism according to claim 1, further comprising detection means for detecting a relative position of the wire delivery end with respect to the support base.   5. The wire buffer according to claim 4, wherein the detection means includes an arm that rotates by engaging a tip of the wire guide in the vicinity of the wire delivery end, and a rotary encoder that detects the rotation of the arm. Formation mechanism. A wire supply apparatus comprising the wire buffer forming mechanism according to claim 4,
A wire reel through which a wire introduced into the wire introduction end is drawn out;
Wire push means for pushing the wire fed from the wire reel toward the wire introduction end;
Wire pulling means for pulling the wire delivered from the wire delivery end;
And a control means,
The wire feeding device, wherein the control means controls the pushing of the wire by the wire push means so that the position of the wire delivery end detected by the detection means becomes a reference position. A wire supply device according to claim 6 is provided, and a welding / spraying torch is supported via a multi-joint arm with respect to the base, and the wire fed from the wire reel is supplied from the welding / spraying torch and welded. Or a welding / spraying robot that performs thermal spraying,
The wire buffer forming mechanism is mounted on any of the articulated arms,
A welding / spraying robot in which a wire fed from the wire feed end is supplied to the welding / spraying torch.

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