JP2000176650A - Variable feature dimension tool and method of varying its feature dimension - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tool whose feature dimensions can be varied and a method for varying its feature dimensions. SOLUTION: The tool is provided with a fixed side member 20, a movable side member 10, and a position locking mechanism 30 which is installed for at least one each in the fixed side and movable side members, which allows movement at least in one direction of the axial and the rotary direction between the two members, and which is also capable of locking such movement. With the position locking mechanism unlocked, the feature dimension of the tool 1 is varied using a robot control device 41, and then the position locking mechanism is locked again.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool (for example, a spot welding gun, a sealant application gun, etc.) having variable characteristic dimensions (representative dimensions) and a method of changing the characteristic dimensions of the tool.

[0002]

2. Description of the Related Art When a tool is, for example, a welding gun supported by a robot, to change a characteristic dimension of the welding gun,
Conventionally, this has been achieved by replacing the welding gun with one having a different characteristic size. In addition, a normal C-type welding gun (C
End of a pipe-shaped work that cannot be welded with a welding gun that has a fixed-side welding tip attached to one end of a cylindrical frame and a movable-side welding tip attached to the other end, and that allows the movable-side welding tip to reciprocate linearly with respect to the fixed-side welding tip. In the case of performing spot welding of a part largely separated from the part, a rotary welding gun in which a welding tip capable of increasing the arm length moves on a circumference by a rotary actuator (Japanese Patent Application No. 8-285421).
Alternatively, a hybrid welding gun (Japanese Patent Application No. 10-109015) capable of selecting rotation or reciprocation has been used.

[0003]

However, the conventional measures for changing the tool feature dimensions have the following problems. In the case of replacing the tool, the work of the replacement and the time required for the replacement are required, and after the replacement, adjustment of the data of the tool, the reference point, and the like are required, and the work efficiency is reduced. Further, when a rotary welding gun or a hybrid welding gun is used, the workable area is enlarged as compared with the C-type gun, but the fixed tool characteristic dimensions cannot be changed. SUMMARY OF THE INVENTION An object of the present invention is to provide a feature size variable tool capable of changing a feature size by a tool itself and a feature size changing method of a feature size variable tool for changing a feature size of the tool.

[0004]

The present invention to achieve the above object is as follows. (1) A fixed side portion, a movable portion relatively movable with respect to the fixed side portion, and at least one movable portion provided at each of the fixed side portion and the movable side portion; A position locking mechanism that allows movement in at least one direction of rotation and locks the movement. (2) The feature dimension variable tool according to (1), wherein the feature dimension variable tool is a welding gun. (3) a fixed side portion, a movable portion relatively movable with respect to the fixed side portion, and at least one each of the fixed side portion and the movable side portion provided in the axial direction between the two members. A method for changing the characteristic dimension of a characteristic dimension variable tool, comprising: a position locking mechanism that allows movement in at least one direction of rotation and can lock the movement, wherein a step of unlocking the position locking mechanism; Changing the characteristic size of the tool to a desired size by using a control device of a robot that supports the tool while fixing the position and posture of the portion of the tool on the distal end side with respect to the position locking mechanism; Locking the locking mechanism to fix the adjusted characteristic dimension of the tool, and a method for changing the characteristic dimension of the characteristic dimension variable tool.

In the feature size changing tool of (1) and (2), and the feature size changing method of the feature size changing tool of (3), the position locking mechanism is unlocked and the fixed side portion and the movable side portion are unlocked. By changing the relative axial or rotational position of the two members in each case, and then locking the position lock mechanism, the characteristic dimensions of the tool can be changed. With this change, the tool working area can be enlarged. In addition, this change can be made without changing the tool and without removing the tool from the robot. And hardly increase the working time.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following description, a case where the tool is a welding gun will be described as an example. However, the tool may be other than a welding gun, for example, a sealant application gun. FIG. 1 shows a case in which the feature size variable tool of the embodiment of the present invention is applied to a C-type welding gun (Example 1), and FIGS. 2 to 5 show feature size variable tools applicable to any of the embodiments of the present invention. FIGS. 6 to 8 show various examples of a tool position locking mechanism. FIGS. 6 to 8 show another embodiment of a feature size variable tool according to the present invention, and a rotary type (rotary type) welding gun (second embodiment). ) And a composite welding gun (Example 3). FIG. 9 shows, in steps, a feature dimension changing method of a feature dimension variable tool applicable to any embodiment of the present invention. In the drawings, parts common or similar to any of the embodiments of the present invention are denoted by the same reference numerals throughout all the embodiments of the present invention.

First, a part common or similar to the feature size variable tool of any embodiment of the present invention will be described with reference to, for example, FIGS. 1 to 5 or FIGS. As shown in FIG. 1, a feature dimension variable tool 1 according to an embodiment of the present invention
(Because the description takes a spot welding gun as an example, hereinafter, it is also referred to as a welding gun 1).
And at least one of each of the movable portion 10 and the fixed side portion 20 and the movable side portion 10 which is relatively movable with respect to the first portion, allows movement in at least one of the axial direction and the rotational direction between the two members. And a position lock mechanism 30 capable of locking the movement.

[0008] The welding gun 1 is supported by a robot 40. The robot 40 is, for example, a six-axis joint type welding robot. The welding gun 1 is attached to the wrist of the robot 40. The movement locus of the welding gun 1 is controlled by a robot control device 41 that controls the robot 40. The movable side 10 of the welding gun 1 is
1 and a movable arm 12 extending to the movable welding tip 11. The fixed side portion 20 has a fixed side welding tip 21 and has a fixed side arm 22 extending to the fixed side welding tip 21. The movable-side welding tip 11 can move forward and backward to the fixed-side welding tip 21, and is moved forward and backward by the actuator 13.

In the case of a C-type welding gun (shown in FIG. 1), the actuator 13 comprises a mechanism for converting the rotation of a servo motor 13a into a reciprocating linear motion by a ball screw 13b, or an air cylinder. In the case of a welding gun (shown in FIGS. 6 and 8) or in the case of a composite welding gun (shown in FIGS. 7 and 8), the stator 13 is used.
c and a mechanism having a rotor 13d. The actuator 13 has a welding tip 11,
21 or the position lock mechanism 30
May be on the robot 40 side. FIG. 1 shows that the actuator 13 has the welding tip 1
6 and 7 show the case where the actuator 13 is closer to the robot 40 than the position lock mechanism 30. FIG.

The position lock mechanism 30 is provided on the movable side 10 and the fixed side 20, respectively. It is desirable that the position where the position lock mechanism 30 is provided is in the middle of the movable arm 12 and the fixed arm 22. In the part where the position lock mechanism 30 is provided, the movable side part (of the movable side arm 12) is divided into two members 12a and 12b across the position lock mechanism 30, as shown in FIGS. The fixed side portion 20 (the fixed side arm 22 thereof) is also divided into two members 22a and 22b with the position lock mechanism 30 interposed therebetween.

Two members 12a, 12b and 22a,
22b is capable of relative movement in at least one of the axial direction and the rotation direction of the member. FIG. 2 shows one of the members 12a and 22a.
Indicates a case in which it is possible to slide in the axial direction and also in the rotational direction with respect to the other members 12b and 22b (the two-dot chain line indicates a state of sliding). The position lock mechanism 30 may be configured to allow only one of the axial direction and the rotational direction.

The position lock mechanism 30 includes two members 12.
a, 12b and a lock portion 31 for locking (fixing) the relative positions of 22a, 22b. The lock unit 31
The structure may be arbitrary as long as it can be releasably locked. For example, an electromagnetic brake as shown in FIGS. 2 and 3 may be used, or a lock hole and a lock hole as shown in FIGS. It may be composed of a pin that enters and exits, or may be composed of a keyway and a key that enters and exits the keyway (not shown).

The electromagnetic brake whose principle is shown in FIGS.
The brake piece 32 divided in the circumferential direction is always pressed against the members 12a and 22a by the spring 33 to be locked, and when the electromagnet 34 is energized, the brake piece 32 is separated from the members 12a and 22a against the urging force of the spring 33. Release the lock to release it. The brake structure has an advantage that the positions of the two members 12a, 12b and 22a, 22b can be adjusted steplessly in both the axial direction and the rotational direction. However, when a load larger than the braking force is applied, the slip occurs. It must be used within a load range that does not cause it. 4 and 5 show the principle of the lock mechanism in the axial direction and the rotation direction, respectively.
a, 22a are provided with a plurality of grooves 35, while the other 12b,
A pin 36 rotatably provided on the member side of the member 22b is attached to a spring 37.
Urges the groove 35 into the groove 35 so that the pin 36 is always locked, and when the electromagnet 38 is energized, the pin 36 is attracted in a direction to be removed from the groove 35 to release the lock. . Control of locking and unlocking of the position lock mechanism 30 is performed by a clamper / brake controller 42. The clamper / brake controller 41 communicates with the robot controller 40, and preferably a part of the robot controller 41 is used.

The operation of the parts common or similar to the welding guns of the above embodiments is as follows. Since the position lock mechanism 30 is provided, the characteristic size of the welding gun 1 is variable, and after changing the characteristic size, the position and the posture can be locked. In this case, the characteristic dimensions of the welding gun 1 are such that the movable welding tip 11 in the welding pressurizing direction (the direction in which the movable welding tip 11 advances and retreats to the fixed welding tip 21) is farthest from the fixed welding tip 21. Welding tip 11 and fixed welding tip 21
Distance, movable side welding tip 11 and fixed side welding tip 2
1. Distance from the robot wrist, movable side welding tip 11
And the angle and posture of the fixed-side welding tip 21 with respect to the robot wrist. Accordingly, various required characteristic dimensions can be changed without removing and replacing the welding gun 1 from the robot 40, and the work area can be expanded without lowering work efficiency. When this is used for spot welding of an automobile body, the range that can be welded by one welding robot is widened, and the efficiency of welding work can be increased, and the number of welding robots can be reduced.

Next, the specific parts of the welding gun of each embodiment of the present invention will be described. In the welding gun according to the first embodiment of the present invention, as shown in FIG. 1, the welding gun 1 is a C-type gun (a frame having a C shape), and the movable frame 12 and the fixed frame 22 cooperate. It constitutes a C-shaped frame. The actuator 13 is of a linear motion reciprocating type and includes a servomotor 13a, a ball screw 13b or an air cylinder. A portion of the movable frame 12 extending parallel to the welding pressurizing direction (a direction in which the movable welding tip 11 is reciprocated by the actuator) and a portion of the movable frame 12 extending in a direction perpendicular to the welding pressurizing direction. , Each is provided with a position lock mechanism 30. Similarly, a portion of the fixed frame 22 extending parallel to the welding pressurizing direction (a direction in which the movable welding tip 11 is reciprocated by the actuator) and a portion of the fixed frame 22 perpendicular to the welding pressurizing direction. Each of the extending portions is provided with a position lock mechanism 30.

The position lock mechanism 30 may have a structure capable of at least one of sliding in the axial direction and sliding in the rotating direction (both can be performed in the illustrated example) and locking and unlocking at that position. And the electromagnetic brake type shown in FIG. Thus, the distance between the movable side welding tip 11 and the fixed side welding tip 12 when the movable side welding tip 11 is opened can be changed and enlarged, and the distance between the movable side welding tip 11 and the fixed side welding tip 12 from the robot wrist can be increased. You can change the distance, enlarge and expand. Thereby, the working area where the welding tip can approach can be expanded.

In the second embodiment of the present invention, as shown in FIGS. 6 and 8, the welding gun 1 is a rotary gun, and the actuator 13 is a rotary reciprocating type, and is fixed to the wrist of the robot 40. It has a stator 13c which is a member to be connected and a rotor 13d which rotates relatively to the stator 13c. 13e is a coil of a DD (direct drive) type servo motor, 13f is a transformer for welding current, 1
3g and 13h are current paths, and 13i is a transformer supporting bracket. A portion of the movable frame 12 extending in the axial direction of the actuator 30 includes a position lock mechanism 30.
The position lock mechanism 30 is also provided on a portion of the movable side frame 12 extending in the radial direction of the actuator 30 in some cases. Similarly, a position locking mechanism 30 is provided on a portion of the fixed side frame 22 extending in the axial direction of the actuator 30, and in some cases, on a portion of the fixed side frame 22 extending in the radial direction of the actuator 30. Also, a position lock mechanism 30 is provided.

The position lock mechanism 30 may have any structure that can perform at least one of axial slide and rotational slide (both can be performed in the illustrated example) and can lock and unlock at that position. And the electromagnetic brake type shown in FIG. Thereby, the distance between the movable-side welding tip 11 and the fixed-side welding tip 21 when the movable-side welding tip 11 is opened can be changed and enlarged, and the distance between the movable-side welding tip 11 and the fixed-side welding tip 21 from the robot wrist can be increased. You can change the distance, enlarge and expand. Thereby, the working area where the welding tip can approach can be expanded.

In a third embodiment of the present invention, as shown in FIGS. 7 and 8, a welding gun 1 is a composite type gun (a rotary welding gun according to the second embodiment, and an arm in a direction perpendicular to the axial direction of the actuator). (Combined with a long extending X-type welding gun). The actuator 13 is a rotary reciprocating type (Embodiment 2)
And a stator 13c, which is a member fixedly connected to the wrist of the robot 40, and a rotor 13d which rotates relatively to the stator 13c. A position locking mechanism 30 is provided on a portion of the movable frame 12 that extends toward the rotary welding gun in the axial direction of the actuator 30, and in some cases, the position lock mechanism 30 is provided in the radial direction of the actuator 30 of the movable frame 12. The position lock mechanism 30 is also provided at the portion extending to the position. Similarly, a position locking mechanism 30 is provided on a portion of the fixed side frame 22 extending in the axial direction of the actuator 30, and in some cases, on a portion of the fixed side frame 22 extending in the radial direction of the actuator 30. Also, a position lock mechanism 30 is provided. The movable frame 12 'of the X-type welding gun is moved to the actuator 3 from the distal end of the portion of the movable frame 12 of the rotary welding gun that extends in the radial direction of the actuator 30.
The movable frame 12 ′ is provided with a position lock mechanism 30.
Similarly, from the tip of the portion of the fixed side frame 22 of the rotary welding gun that extends in the radial direction of the actuator 30, the direction of the fixed side frame 22 ′ of the X-type welding gun is perpendicular to the axial direction of the actuator 30. The position locking mechanism 30 is provided on the fixed side frame 22 ′.

The position lock mechanism 30 may have any structure that can perform at least one of axial slide and rotational slide (both can be performed in the illustrated example) and can lock and unlock at that position. And the electromagnetic brake type shown in FIG. Thus, the distance between the movable welding tip 11 and the fixed welding tip 12 when the movable welding tip 11 is opened can be changed and enlarged for both the rotary welding gun and the X-type welding gun. The distance between the tip 11 and the fixed-side welding tip 12 from the wrist of the robot can be changed and enlarged. Thereby, the working area where the welding tip can approach can be expanded.

Next, a method for changing the characteristic dimension of the characteristic dimension variable tool (for example, the welding gun 1) according to the embodiment of the present invention will be described with reference to FIGS. 1, 6, 7, and 9, for example.
The feature size changing method of the feature size variable tool 1 according to the embodiment of the present invention includes a fixed side portion 20, a movable portion 10 movable relatively to the fixed side portion 20, and a fixed side portion 20 and a movable side portion 10. A position locking mechanism 30 provided at least one in each case and capable of locking movement in at least one direction in the axial direction and the rotation direction between the two members and locking the movement; This is a method for changing dimensions. As shown in FIG. 9, the characteristic dimension changing method of the characteristic dimension variable tool 1 according to the embodiment of the present invention includes a step 101 for unlocking the position lock mechanism 30 and a position lock mechanism 3 of the tool 1.
A step 102 of adjusting and changing the characteristic size of the tool 1 to a desired size by using the control device 41 of the robot 40 supporting the tool 1 while fixing a portion closer to the tip side than 0, and the position lock mechanism 30 Locking 103 to fix the tool 1 and fix the characteristic dimensions after the change.

The characteristic size of the tool 1 is adjusted to a desired size,
In the changing step 102, the position and posture of the portion of the tool 1 on the tip side of the position lock mechanism 30 is fixed by clamping with the clamper 104 or engaging with the engaging tool 105. Thereafter, the control device 41 of the robot 40 supporting the tool 1 is used to control the position and orientation of the tip of the robot 40, and the characteristic dimensions of the tool 1 are adjusted and changed to desired dimensions. It is not necessary to replace the tool 1 from the robot 40, and the position and the posture are adjusted with high accuracy by the robot controller 41. Tool 1
Since there is no replacement from the robot 40, the reference point adjustment,
No data reading is required. The clamp and release of the clamp by the clamper 104 are performed by the clamp / brake controller 42.

[0023]

According to the feature size changing tool of the first and second aspects and the feature size changing method of the feature size changing tool of the third aspect, since the position lock mechanism is provided, the lock of the position lock mechanism is released. Then, by changing the relative axial direction or the rotational direction position of the two members on each of the fixed side portion and the movable side portion, and then locking the position locking mechanism, the characteristic dimensions of the tool can be changed. With this change, the tool working area can be enlarged. In addition, this change can be made without changing the tool and without removing the tool from the robot. And hardly increase the working time.

[Brief description of the drawings]

FIG. 1 is a schematic side view of a feature size variable tool (for example, a welding gun) of a first embodiment of the present invention, a robot equipped with the tool, and a system thereof.

FIG. 2 is a perspective view of a position lock mechanism applicable to any embodiment of the present invention.

FIG. 3 is a sectional view of the position lock mechanism of FIG. 2;

FIG. 4 is a side view showing a locking principle of an axial locking mechanism of another type of position locking mechanism different from FIG. 2;

5 is a front view showing a locking principle of a rotation direction locking mechanism of a position locking mechanism of another type different from FIG.

FIG. 6 is a schematic perspective view of a feature dimension variable tool according to a second embodiment of the present invention and a robot to which the tool is attached.

FIG. 7 is a schematic perspective view of a feature size variable tool according to a third embodiment of the present invention and a robot to which the tool is attached.

FIG. 8 is a sectional view of an actuator of a feature size variable tool according to Examples 2 and 3 of the present invention.

FIG. 9 is a process diagram of a method for changing a characteristic dimension of a characteristic dimension variable tool (for example, a welding gun) according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Welding gun 10 Movable side part 11 Movable side welding tip 12 Movable side arm 12a, 12b Two members of movable side arm 13 Actuator 20 Fixed side part 21 Fixed side welding tip 22 Fixed side arm 22a, 22b Two members of fixed side arm 30 Position lock mechanism 31 Lock section 40 Robot 41 Robot controller 42 Clamper / brake controller

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B25J 15/08 B25J 15/08 C

Claims (3)

[Claims] A fixed side portion, a movable portion relatively movable with respect to the fixed side portion, at least one of each of the fixed side portion and the movable side portion.
One after another, allowing movement in at least one of the axial and rotational directions between the two members and locking the movement,
And a position locking mechanism. 2. The feature size variable tool according to claim 1, wherein the feature size variable tool is a welding gun. 3. A fixed side portion, a movable portion relatively movable with respect to the fixed side portion, and at least one each of the fixed side portion and the movable side portion, the shaft being provided between two members. A feature size changing method for a feature size variable tool, comprising: a position locking mechanism that allows movement in at least one direction of the rotation direction and the rotation direction and locks the movement, wherein the position locking mechanism is unlocked. Changing the characteristic dimensions of the tool to desired dimensions by using a robot controller that supports the tool by fixing the position and orientation of a portion of the tool closer to the tip end than the position lock mechanism; Locking the position lock mechanism to fix the adjusted characteristic dimension of the tool.