JP2011189352A - Welding apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a welding apparatus capable of reducing the robot operational track and shortening the space moving time when changing the attitude of a welding gun, and further shortening the setup working time. <P>SOLUTION: The welding apparatus includes an articulated robot 1, and a gun mounting arm 2 to be mounted via a wrist hinge part 1a at the tip end of the robot 1. A welding gun 3 for spot welding is pivotally attached to the gun mounting arm 2 freely rockably around the horizontal axis La. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a welding apparatus.

  A conventional welding apparatus attaches a gun mounting arm via a wrist joint at the tip of a robot, and fixes a welding gun for spot welding to the gun mounting arm (see, for example, Patent Document 1).

Japanese Patent No. 4218866

  However, in the conventional welding apparatus, it has been necessary to move the posture of the robot in a large and complex manner in order to change the approach of the welding gun in accordance with a plurality of positions to be welded on the workpiece. For this reason, the robot's space movement time (air cut time) and the motion trajectory (movement trajectory) become longer, and the time required to weld one workpiece (takt time) has been wasted. In addition, there is a problem that a great amount of time and labor are spent on teaching setting and operation confirmation in the setup work.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a welding apparatus capable of shortening the operation trajectory and space movement time of the robot and further shortening the setup work time when changing the attitude of the welding gun.

  In order to achieve the above object, a welding apparatus according to the present invention includes an articulated robot and a gun attachment arm attached via a wrist joint at the tip of the robot, and the gun attachment arm includes A welding gun for spot welding is pivotally mounted around a horizontal axis so as to be swingable.

  Further, a base part rotatable around a vertical axis, a first arm part pivotally attached to the base part around a first horizontal axis, and a second horizontal part on the first arm part. A second arm portion pivotably mounted around the axis, a wrist joint provided at the tip of the second arm, and a swing around the third horizontal axis by the wrist joint A gun attachment arm pivotally attached to the gun attachment arm, and a spot welding welding gun pivotally attached around the fourth horizontal axis.

  According to the welding apparatus of the present invention, it is possible to improve the degree of freedom of the posture change operation of the welding gun, simplify the posture change operation, and perform welding while minimizing the space movement time and the operation trajectory. It eliminates the waste of operation and can weld smoothly and efficiently, improving the production capacity. In addition, the setup work time for initial teaching setting and operation check can be greatly reduced. It is not necessary to rotate a jig device such as a turntable or a pallet device for changing the posture of the workpiece, so that the work can be performed quickly and efficiently, and the entire production equipment can be simplified. The welding range can be improved by bringing the welding gun closer to the workpiece from various directions. The degree of freedom of the posture (gun approaching posture) when approaching the workpiece is improved, and it is possible to deal with various shapes of workpieces and jig devices.

It is a side view of embodiment of the welding apparatus of this invention. It is an operation explanatory view. It is an operation explanatory view. It is an operation explanatory view. It is operation | movement explanatory drawing of a comparative example. It is operation | movement explanatory drawing of a comparative example.

Hereinafter, the present invention will be described in detail based on the illustrated embodiment.
In FIG. 1, a welding apparatus according to the present invention includes a base portion 10 that is rotatable about a vertical axis Lо, and a base end side of the base portion 10 that is pivotable about a first horizontal axis L1. The worn first arm portion 11, the second arm portion 12 pivotally attached to the distal end side of the first arm portion 11 about the second horizontal axis L2, and the distal end of the second arm portion 12 ( And an articulated industrial robot 1 having a wrist joint portion 1a provided on the side).

  And the gun attachment arm 2 attached via the wrist joint part 1a of the front-end | tip (side) of the robot 1 is provided. The gun mounting arm 2 is pivotally attached around the third horizontal axis L3 by the wrist joint 1a. That is, the wrist joint portion 1a of the robot 1 is pivotally attached to the wrist shaft 13 and the horizontal wrist shaft 13 that is driven to rotate around the third horizontal axis L3 on the distal end side of the second arm portion 12 (for attachment). ) Mounting portion 14. Then, by attaching the gun mounting arm 2 to the mounting portion 14, when the wrist shaft 13 is driven to rotate, the gun mounting arm 2 swings around the third horizontal axis L3.

Further, a welding gun 3 for spot welding is pivotally attached to the gun mounting arm 2 so as to be swingable around a fourth horizontal axis La.
The welding gun 3 is attached (fixed) to a support shaft 5 whose both ends are rotatably supported by the gun mounting arm 2, and swings when the support shaft 5 is driven to rotate around the fourth horizontal axis La. It is provided to do. Alternatively, the support shaft 5 is fixed to the gun mounting arm 2, the welding gun 3 is pivotally attached to the support shaft 5, and is rotated around the fourth horizontal axis La (support shaft 5) with a feeding device such as a gear. Alternatively, the welding gun 3 may be swingably provided.

  The welding gun 3 is controlled by a control unit (not shown) via a rotation positioning mechanism that can be stopped at a desired rotation position (rotation angle). That is, the welding gun 3 is provided to be swingable and fixed around the fourth horizontal axis La. Moreover, it has a pair of 1st electrode 3a and 2nd electrode 3b which are arrange | positioned facing each other at the front-end | tip side of the welding gun 3. As shown in FIG. The first support member 30 has the first electrode 3a attached to the tip at a substantially right angle, and the second support member 31 has the second electrode 3b attached to the tip at a substantially right angle. The first support member 30 and the second support member 31 are provided in parallel, and are opened and closed in a reciprocating (opening and closing) operation direction N that causes the pair of first electrodes 3a and second electrodes 3b to approach and separate from each other.

The fourth horizontal axis La is disposed on a plane perpendicular to the reciprocating (opening / closing) operation direction N (welding axis Le) in which the pair of first electrodes 3a and second electrodes 3b approach and separate. It is arranged in parallel with the third horizontal axis L3.
In FIG. 1, the fourth horizontal axis La, the first horizontal axis L1, the second horizontal axis L2, and the third horizontal axis L3 are parallel to each other.

  The operations on the robot 1 side such as the rotation of the base 10, the swing of the first arm 11, the swing of the second arm 12, and the swing of the gun mounting arm 2 and the swing of the welding gun 3 are as follows: The control unit is provided so as to be able to perform synchronous (simultaneous) drive control, and is controlled so as to operate on an optimal trajectory by a combination or selection of drive (operation) around each axis.

Next, the method of use (action) of the welding apparatus according to the embodiment of the present invention will be described in comparison with the welding apparatus of the comparative example.
First, in the present invention, as shown in FIG. 2, the welding gun 3 moves from the vertical welding position in which the horizontal plane portion of the workpiece W is sandwiched, and the welding gun 3 moves the vertical plane portion of the workpiece W as shown in FIG. 3. A case where the posture is changed to the sandwiched horizontal welding posture will be described. In the present invention, longitudinal welding refers to an operation in which the welding surface is horizontal and the welding axis Le is vertical. Further, lateral welding refers to an operation in which the welding surface is vertical and the welding axis Le is horizontal. In FIG. 2, the first support member 30 and the second support member 31 are horizontally arranged, and the horizontal support is formed by the first support member 30 and the second support member 31 approaching and separating from each other. Welding is possible so that the welding surface is sandwiched between the first electrode 3a and the second electrode 3b (shown in FIG. 1). Such a posture of the welding gun 3 is also referred to as a horizontal welding spot posture. Further, in FIG. 3, the first support member 30 and the second support member 31 are arranged in a vertical shape, and the vertical surface-like weld surface is connected to the first electrode 3a and the second electrode (shown in FIG. 1). Welding is possible so as to be sandwiched between the electrodes 3b. This posture of the welding gun 3 is also referred to as a vertical welding spot posture.

In the present invention, the welding gun 3 is swung around the fourth horizontal axis La so that the welding axis Le changes from the vertical state to the horizontal state from the vertical welding posture (see FIG. 2), and the second arm The part 12 and the gun mounting arm 2 are swung upward, and the first arm part 11 is swung forward, so that a horizontal welding posture (see FIG. 3) is obtained.
That is, the posture can be easily and quickly changed by operating the first arm portion 11, the second arm portion 12, the gun mounting arm 2 and the welding gun 3 only once in one direction (one operation). . In other words, in FIG. 3, the welding gun 3 can be moved up in the arrow Z direction. In the present invention, “front” refers to the direction of the arrow X from the base 10 toward the workpiece W.

In the comparative example, as shown in FIG. 5, a welding gun 3 ′ is directly fixed to a gun mounting arm 2 ′ attached via a wrist joint 1 a ′ at the tip of the robot 1 ′. is there.
From the vertical welding posture of FIG. 5A, as shown in FIG. 5B, the first arm portion 11 ′ and the second arm portion 12 ′ are swung rearward (in the direction of the arrow Y), and the welding gun 3 'Is greatly separated (retreated) from the workpiece W.
Next, as shown in FIGS. 5 (c) and 5 (d), the gun mounting arm 2 'and the welding gun 3' are connected to a rotation axis (reverse axis) Lβ perpendicular to the third horizontal axis L3 '. Rotate 180 degrees around. Moreover, in order to prevent the welding gun 3 'from coming into contact with the workpiece W or the base 10' during reversal, the second arm 12 'and the gun mounting arm 2' are swung upward to weld the gun 3 It is necessary to escape 'in advance.
Next, as shown in FIG. 5E, while swinging the gun mounting arm 2 'further upward, the second arm 12' is swung downward and the first arm 11 'is swung forward. The welding gun 3 ′ is moved closer to the workpiece W. And it is set as the horizontal welding attitude | position shown in FIG.5 (f).
That is, in the comparative example, as shown in FIG. 5, the first arm portion 11 ′ performs two operations (reciprocating operation) that swings forward after retreating. It can be seen that the second arm portion 12 ′ performs three actions of swinging upward after retreating and then swinging downward. The gun mounting arm 2 ′ performs two operations (reciprocating operation) that swings downward after swinging upward. Further, it is necessary that the joint 1a ′ not only swings the welding gun 3 about the third horizontal axis L3 via the gun mounting arm 2 ′ but also performs a reversing operation for rotating 180 degrees about the reversing axis Lβ. is there.

  That is, according to the present invention, since the welding gun 3 can be swung around the fourth horizontal axis La, it is not necessary to rotate 180 degrees around the axis perpendicular to the third horizontal axis L3. This eliminates the need for a large escape to prevent interference with the jig device and the base 10 and the need for re-approaching from the escaped position (need to reciprocate). Simplification, space movement time and operation trajectory are shortened (simplification), and the posture of the welding gun 3 can be easily and quickly changed.

  Further, according to the present invention, as shown in FIG. 4, the gun mounting arm 2 can be moved so as to pass over the workpiece W so that the welding gun 3 wraps around the back side Wb of the workpiece W. The front side Wa of the workpiece W is the side facing the base 10 of the robot 1, and the opposite side is called the back side Wb.

  In the comparative example, as shown in FIG. 6, the welding gun 3 ′ is fixed to the gun mounting arm 2 ′. Therefore, the welding gun 3 ′ can be disposed only up to the upper part of the work W, and the back side Wb of the work W It is difficult to weld. Therefore, in order to weld the back side Wb of the work W, a jig device such as a turntable (pallet) is controlled to rotate (reverse) the work W 180 degrees around the vertical axis, or the back side of the work W It is necessary to arrange another welding apparatus for Wb.

  In other words, in the present invention, the weldable range is widened (the back side Wb of the workpiece W can be welded), and the time for reversing the workpiece W with the jig device is omitted. In addition, in order to prevent the welding gun 3 from coming into contact with the workpiece W to be reversed, an operation for largely releasing the welding gun 3 is not required, and the production time can be shortened. Alternatively, it is not necessary to provide another welding device in a face-to-face manner with the workpiece W interposed therebetween, and the equipment in the welding process can be simplified.

  In addition, the welding gun 3 can be easily changed to various welding postures, and when performing welding, it is possible to shorten the operation time (space movement time) for performing only the posture change, and to approach the workpiece W. At this time, it is difficult to be influenced by the shape of the workpiece W (the complicated workpiece W and the protruding portion of the jig device are easily dodged).

  The design of the present invention can be changed, and the welding gun 3 may have a shape other than that shown in the figure. That is, it may be used for spot welding that has a pair of first and second electrodes 3a and 3b facing each other and the first electrode 3a and the second electrode 3b approach and separate from each other. Further, the robot 1 may be such that the attachment portion 14 of the wrist joint portion 1a can swing around the third horizontal axis L3 by a feeding device such as a gear.

  As described above, the welding apparatus of the present invention includes the articulated robot 1 and the gun mounting arm 2 attached via the wrist joint 1 a at the tip of the robot 1. Since the welding gun 3 for spot welding is pivotally mounted around the horizontal axis La, the degree of freedom of posture changing operation of the welding gun 3 can be improved, the posture changing operation can be simplified, the space movement time, It can be welded with a minimum (shortest) motion trajectory. It eliminates waste of operation and can perform welding smoothly and efficiently, improving production capacity. In addition, the setup work time for initial teaching setting and operation check can be greatly reduced. By making the welding gun 3 approach the workpiece W from various directions, the weldable range can be improved. That is, the degree of freedom of the posture (gun approaching posture) when approaching the workpiece W can be improved, and various shapes of the workpiece W can be dealt with. The welding gun 3 can be disposed so as to wrap around the back side Wb of the workpiece W, and there is no need to rotate a jig device such as a turntable or a pallet device for changing the posture of the workpiece W. It is possible to work and simplify the entire production facility. The posture of the welding gun 3 can be easily changed without causing the robot 1 to perform a complicated posture changing operation.

  Further, a base portion 10 that is rotatable around the vertical axis Lо, a first arm portion 11 that is pivotally attached to the base portion 10 around a first horizontal axis L 1, and a first arm portion 11. The second arm portion 12 pivotably mounted around the second horizontal axis L2 at the second arm portion 12, the wrist joint portion 1a provided at the tip of the second arm portion 12, and the wrist joint portion 1a, the third horizontal axis. A gun mounting arm 2 pivotably mounted around the center L3, and a spot welding welding gun 3 pivotally mounted around the fourth horizontal axis La on the gun mounting arm 2. Therefore, the degree of freedom of the posture changing operation of the welding gun 3 can be improved, the posture changing operation can be simplified, and welding can be performed while minimizing the space movement time and the operation trajectory. It eliminates waste of operation and can perform welding smoothly and efficiently, improving production capacity. In addition, the setup work time for initial teaching setting and operation check can be greatly reduced. By making the welding gun 3 approach the workpiece W from various directions, the weldable range can be improved. That is, it is possible to improve the degree of freedom of posture when approaching the workpiece W, and to cope with various shapes of the workpiece W. The welding gun 3 can be disposed so as to wrap around the back side Wb of the workpiece W, and there is no need to rotate a jig device such as a turntable or a pallet device for changing the posture of the workpiece W. It is possible to work and simplify the entire production facility. Even in the robot 1 having the wrist joint portion 1a that cannot rotate around the rotation (reversal) axis Lβ orthogonal to the horizontal axis L3, the switching operation between the vertical welding and the horizontal welding can be performed quickly and easily. It can be carried out. The posture of the welding gun 3 can be easily changed without causing the robot 1 to perform a complicated posture changing operation.

1 Robot 1a Wrist joint 2 Gun mounting arm 3 Welding gun
10 base
11 First arm
12 Second arm Lо Vertical axis L1 First horizontal axis L2 Second horizontal axis L3 Third horizontal axis La (Fourth) horizontal axis

Claims (2)

An articulated robot (1), and a gun mounting arm (2) attached via a wrist joint (1a) at the tip of the robot (1),
A welding apparatus characterized in that a welding gun (3) for spot welding is pivotally mounted around the horizontal axis (La) to the gun mounting arm (2). A base portion (10) rotatable around a vertical axis (Lо), and a first arm portion pivotably attached to the base portion (10) around a first horizontal axis (L1) ( 11), a second arm portion (12) pivotably attached to the first arm portion (11) about a second horizontal axis (L2), and a tip of the second arm portion (12) A wrist joint portion (1a) provided on the gun, and a gun mounting arm (2) pivotably mounted around the third horizontal axis (L3) by the wrist joint portion (1a),
A welding apparatus characterized in that a welding gun (3) for spot welding is pivotally attached to the gun mounting arm (2) so as to be swingable around a fourth horizontal axis (La).

Images