Articulated robot

Abstract

Fold the arms so that the links overlap. [Solution] The articulated robot 1 comprises a base 10 having a joint JT1 that rotates around a first axis Ax1, a first link 21 that rotates relative to the base 10 around a second axis Ax2, a second link 23 that rotates around a third axis Ax3, and a third link 22 that is located between the first link and the second link in the second direction to connect the first link and the second link, and that rotates relative to the first link around a fourth axis Ax4 at a first end 221 and rotates relative to the second link around the third axis at a second end 222.

Description

[Technical Field]

[0001] The technology disclosed herein relates to an articulated robot. [Background technology]

[0002] Patent Document 1 describes a conventional robot. The conventional robot is installed in a paint booth and paints the interior and exterior surfaces of a vehicle. The conventional robot is a multi-axis robot with six or seven axes. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2011-525418 Summary of the Invention [Problem to be solved by the invention]

[0004] An articulated robot that performs work on a workpiece is positioned to the side of the workpiece and extends its arm toward the workpiece. If the tip of the extended arm can be moved farther away from the robot's base, the robot's working range with respect to the workpiece will be wider. However, it is difficult to bring the tip of the arm close to the robot's base when a long arm is folded. A robot with a long arm will encounter interference between the arm and the workpiece unless the distance between the robot and the workpiece is increased. In order to ensure a wide distance between the robot and the workpiece, a large work booth is required. On the other hand, if the distance between the robot and the workpiece is wide, there is a risk that the tip of the arm will not reach the edge of the workpiece even when extended. [Means for solving the problem]

[0005] The technology disclosed herein relates to an articulated robot. a base having a joint that rotates around a first axis extending in a first direction; a first link supported by a bracket of the base and rotatable relative to the base about a second axis extending in a second direction intersecting the first direction; a second link that rotates about a third axis parallel to the second axis; and a third link located between the first link and the second link in the second direction to connect the first link and the second link, and rotating at a first end relative to the first link around a fourth axis parallel to the second axis and the third axis, and rotating at a second end relative to the second link around the third axis. [Effects of the Invention]

[0006] In the articulated robot, the first link, the third link, and the second link are aligned in this order in the second direction, so that the arm can be folded so that the first link and the third link overlap. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a side view of an articulated robot. [Figure 2] FIG. 2 is a plan view of the articulated robot. [Figure 3] The upper diagram in FIG. 3 is a plan view of the articulated robot with its arms folded, and the lower diagram is a side view of the articulated robot with its arms folded. [Figure 4] Figure 4 shows a work booth where an articulated robot works on a workpiece. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, an embodiment of an articulated robot will be described with reference to the drawings. The articulated robot described here is an example.

[0009] FIG. 1 shows a side view of the articulated robot 1. FIG. 2 shows a plan view of the articulated robot 1. The articulated robot 1 is a so-called vertical articulated robot. In the following description, for convenience, the X-axis, Y-axis, and Z-axis are defined as follows, based on the installation of the articulated robot 1. The Z-axis is an axis perpendicular to the installation surface of the articulated robot 1. The X-axis and Y-axis are axes along the installation surface of the articulated robot 1 and are perpendicular to the Z-axis. The Y-axis is a direction perpendicular to the plane of the paper in FIG. 1, and the X-axis is perpendicular to the Y-axis. The X-axis, Y-axis, and Z-axis are used only to describe the articulated robot 1 and are not used to limit the structure or shape of the articulated robot 1.

[0010] The articulated robot 1 includes a base 10. The base 10 is fixed so as not to move. The base 10 may be mounted on a movable object. The base 10 supports an arm 2 (described later) of the articulated robot 1. The base 10 includes a joint JT1. The joint JT1 rotates around a first axis Ax1 extending in a first direction, i.e., the Z-axis direction. In the example of FIG. 1, the first axis Ax1 is inclined with respect to the vertical direction. The first axis Ax1 may also be in the vertical direction. The joint JT1 is an example of a first joint.

[0011] The base 10 has a bracket 11. The bracket 11 rotates around a first axis Ax1. The bracket 11 supports a link 21, which will be described later. As shown in FIG. 1, the bracket 11 protrudes from the base 10 in the positive direction of the X-axis. As shown in FIG. 2, the bracket 11 is also located at the end of the base 10 in the positive direction of the Y-axis. The position of the bracket 11 is offset in the direction of the Y-axis from the position of the first axis Ax1.

[0012] The articulated robot 1 includes a link 21. The link 21 is an example of a first link. The link 21 is supported by the base 10. More specifically, the link 21 is supported by a bracket 11 of the base 10. As shown in FIG. 2, a first end of the link 21 is supported by the bracket 11 on the opposite side of the bracket 11 from the position of the first axis Ax1 in the Y-axis direction. The first end of the link 21 is the left end of the link 21 in FIG. 2. An empty space 12 is provided on the side of the bracket 11 in the negative direction of the Y-axis and on the side of the base 10 in the positive direction of the X-axis, as surrounded by a dashed line in FIG. 1 or 2. The articulated robot 1 has the empty space 12. As shown in FIG. 2, when the articulated robot 1 is viewed from above, the first axis Ax1 overlaps with the empty space 12 in the Y-axis direction.

[0013] The link 21 rotates relative to the base 10 around the second axis Ax2. That is, a joint JT2 connects a first end of the link 21 to the bracket 11 of the base 10. The second axis Ax2 is an axis extending in the direction of the Y axis. The direction of the Y axis corresponds to the second direction. The direction of the second axis Ax2 is a direction intersecting the direction of the first axis Ax1. More precisely, the direction of the Y axis related to the second axis Ax2 is perpendicular to the direction of the Z axis related to the first axis Ax1, as shown in FIG. 2.

[0014] The articulated robot 1 includes a link 22. The link 22 is an example of a third link. The link 22 has a first end 221 and a second end 222. The first end 221 of the link 22 is the left end of the link 22 in FIG. 2. The second end 222 of the link 22 is the end opposite to the first end 221 and is the right end of the link 22 in FIG. 2. The first end 221 of the link 22 is connected to the second end of the link 21 via a joint JT4. The second end of the link 21 is the end opposite to the first end and is the right end of the link 21 in FIG. 2. The joint JT4 rotates around a fourth axis Ax4. The fourth axis Ax4 is an axis parallel to the second axis Ax2. The link 22 rotates at the first end 221 relative to the link 21 around the fourth axis Ax4.

[0015] 2, the link 22 is located in the negative direction of the Y axis relative to the link 21. The link 22 is located at a position corresponding to the bracket 11 of the base 10 in the direction of the Y axis.

[0016] The articulated robot 1 includes a link 23. The link 23 is an example of a second link. A first end of the link 23 is connected to a second end 222 of the link 22 via a joint JT3. The first end of the link 23 is the left end of the link 23 in FIG. 2. The joint JT3 rotates around a third axis Ax3. The third axis Ax3 is an axis parallel to the second axis Ax2 and the fourth axis Ax4. The link 23 rotates relative to the link 22 around the third axis Ax3. In other words, the link 22 rotates at the second end 222 relative to the link 23 around the third axis Ax3.

[0017] As shown in FIG. 2, link 23 is located in the negative direction of the Y axis relative to link 22. Link 22 is located between links 21 and 23 in the direction of the Y axis. Link 23 is located further in the negative direction of the Y axis than bracket 11 of base 10. Link 23 is located at a position overlapping with first axis Ax1 in the direction of the Y axis. Link 23 is also located at a position corresponding to empty space 12 in the direction of the Y axis.

[0018] The link 23 has a joint JT5. The joint JT5 rotates the second member 232 of the link 23 relative to the first member 231 about the fifth axis Ax5. The first member 231 is located on the base end side of the link 23, and the second member 232 is located on the tip end side of the link 23, with the first member 231 and the second member 232 being adjacent to each other. The fifth axis Ax5 is an axis perpendicular to the fourth axis Ax4.

[0019] The articulated robot 1 includes a link 24. The link 24 is the wrist of the articulated robot 1. A first end of the link 24 is connected to a second end of the link 23 via a joint JT6. The first end of the link 24 is the left end of the link 24 in FIG. 1 or 2. The second end of the link 23 is the end opposite to the first end, and is the right end of the link 23 in FIG. 1 or 2. The joint JT6 rotates around a sixth axis Ax6. The sixth axis Ax6 is an axis that has a predetermined angle with respect to the fifth axis Ax5. The link 24 rotates relative to the link 23 around the sixth axis Ax6.

[0020] The link 24 has a joint JT7. The articulated robot 1 is a seven-axis robot. The joint JT7 rotates around the seventh axis Ax7. The seventh axis Ax7 is an axis that has a predetermined angle with respect to the sixth axis Ax6. The end effector 13 is connected to the link 24. The joint JT7 rotates the end effector 13 around the seventh axis Ax7 relative to the link 24.

[0021] The end effector 13 in the illustration is a spray gun. Note that the articulated robot 1 is not limited to a robot that paints a workpiece. An end effector suitable for the work that the articulated robot 1 performs on the workpiece is connected to the link 24.

[0022] It should be noted that the wrist structure of the articulated robot 1 is not limited to the above structure. The sixth axis Ax6 of the joint JT6 of the articulated robot 1 may be an axis parallel to the third axis Ax3.

[0023] (extending and folding arms) Link 21, link 22, link 23, and link 24 constitute arm 2 of articulated robot 1. Figures 1 and 2 show arm 2 in an extended state. When link 21, link 22, link 23, and link 24 are each oriented to extend along the X-axis, arm 2 is extended long (see L2). Because arm 2 includes four links 21, 22, 23, and 24, articulated robot 1 can position end effector 13 at a position far away from base 10.

[0024] Here, in a conventional multi-joint robot in which the arm extends long, even when the arm is folded, due to interference between links or between a link and the base, the end effector cannot be positioned near the base.

[0025] The multi-joint robot 1 disclosed herein can position the end effector 13 near the base 10 when the arm 2 is folded. FIG. 3 shows an example of a state where the arm 2 is folded. The upper figure in FIG. 3 is a plan view of the multi-joint robot 1, and the lower figure is a side view of the multi-joint robot 1.

[0026] The link 22 is positioned between the link 21 and the link 23 in the direction of the Y-axis. The link 21 and the link 23 are displaced in the direction of the Y-axis. When the arm 2 is folded, the link 21 and the link 23 do not interfere with each other. As shown in FIG. 3, the arm 2 is folded so that the link 21 and the link 23 overlap each other.

[0027] Also, the total length of the link 22 is relatively short. More specifically, as shown in FIG. 1 or 2, in the link 22, the length L from the fourth axis Ax4 to the outermost edge of the second end portion 222 is shorter than the length L0 between the fourth axis Ax4 and the second axis Ax2. More precisely, the length L is shorter than the length L1 from the fourth axis Ax4 to the edge of the bracket 11. As is clear from FIG. 1, L1 < L0. The circle Tr shown by the broken line in FIG. 1 indicates the locus through which the edge of the second end portion 222 of the link 22 passes when it is assumed that the link 22 rotates 360° about the fourth axis Ax4. Since L < L0, the total length of the link 22 is shorter than the total length of the link 21. Also, since L < L1, the link 22 does not interfere with the bracket 11.

[0028] Because link 22 and bracket 11 do not interfere with each other, link 22 approaches base 10 to a position where link 21 and link 22 overlap, as shown in FIG. 3. As indicated by dashed line CL in the lower diagram of FIG. 3, link 22 is displaced to a position where the first center line and second center line overlap when viewed along the Y-axis. The first center line is a line connecting the second axis Ax2 and fourth axis Ax4 of link 21. The second center line is a line connecting the third axis Ax3 and fourth axis Ax4 of link 22. In other words, the second axis Ax2, third axis Ax3, and fourth axis Ax4 are all located on dashed line CL. At this time, the third axis Ax3 is closer to the first axis Ax1 than the second axis Ax2.

[0029] Since the link 22 can be moved closer to the base 10, the end effector 13 is positioned closer to the base 10 as shown by the solid line in the lower diagram of FIG.

[0030] Furthermore, an empty space 12 is formed on the side of the bracket 11. The link 23 is located at a position corresponding to the empty space 12 in the Y-axis direction. Therefore, as shown by the two-dot chain line in the lower diagram of FIG. 3, by rotating the link 23 downward, a portion of the link 23 is positioned within the empty space 12. The end effector 13 is positioned even closer to the base 10 (see L3).

[0031] Furthermore, while the total length of the link 22 of the articulated robot 1 is relatively short, the total length L23 of the link 23 is longer than the total length L22 of the link 22, as can be seen from FIG. 1. Here, the total length of the link is the length from the edge of the first end of the link to the edge of the second end. Since the total length L23 of the link 23 is long, the length of the extended arm 2 is long. Note that the fact that the total length L23 of the link 23 is longer than the total length L22 of the link 22 can also be rephrased as the center-to-center distance of the link 23 being longer than the center-to-center distance of the link 22.

[0032] FIG. 4 shows how articulated robot 1 performs work on workpiece 9. Multiple articulated robots 1A and 1B are positioned on the right and left sides of workpiece 9. Articulated robots 1A and 1B paint workpiece 9. Because arm 2 can be extended, articulated robot 1A can position spray gun 13 at a location on the opposite side of workpiece 9 from the robot. On the other hand, because arm 2 can be folded, articulated robot 1B can position spray gun 13 at a location on the side of workpiece 9 closer to the robot. Note that, in FIG. 4, articulated robot 1B has link 22 closer to base 10 than the position where links 21 and 22 overlap. More specifically, link 22 can be displaced to a position where third axis Ax3 is closer to first axis Ax1 than a first center line CL connecting second axis Ax2 and fourth axis Ax4. That is, in the articulated robot 1, the position where the link 21 and the link 22 overlap is not the limit of the folding of the arm 2.

[0033] The articulated robot 1 can widen the working range for the workpiece 9. The articulated robot 1 improves work efficiency. Furthermore, because the movable range of the arm 2 is wide, the articulated robot 1 can easily avoid interference between the arm 2 and the workpiece 9. The articulated robot 1 can make teaching work smoother.

[0034] The workpiece 9 that the articulated robot 1 targets is not limited to a specific workpiece. The articulated robot 1 can be used in the manufacture of various industrial products, such as home appliances, electronic devices, industrial machinery, medical equipment, automobiles, aircraft, or railway vehicles. The articulated robot 1 has a wide range of operations for the workpiece 9, making it particularly effective for the manufacture of large industrial products.

[0035] Furthermore, the work performed by the articulated robot 1 on the workpiece 9 is not limited to a specific work. The articulated robot 1 can perform various tasks, such as assembly, welding, or painting.

[0036] (Action and effect) Link 21, link 22, and link 23 are arranged in this order in the direction of the Y axis. Because link 21 and link 23 do not interfere with each other, the articulated robot 1 can fold the arm 2 so that link 21 and link 22 overlap, as shown in Figure 3. Furthermore, the articulated robot 1 can fold the arm 2 until it approaches the base 10.

[0037] Since the length L from the fourth axis Ax4 to the outermost edge of the second end 222 of the link 22 is shorter than the length L0 between the fourth axis Ax4 and the second axis Ax2, interference between the link 22 and the base 10 is avoided when the arm 2 is folded.

[0038] Furthermore, since the length L of the link 22 is shorter than the length L1 from the fourth axis Ax4 to the edge of the bracket 11, interference between the link 22 and the bracket 11 is avoided when the arm 2 is folded.

[0039] While the overall length L22 of the link 22 is short, the overall length L23 of the link 23 is long, so that the articulated robot 1 can have an arm 2 with a long overall length.

[0040] Since the link 21 is supported by the bracket 11 on the opposite side of the bracket 11 from the position of the first axis Ax1 in the Y-axis direction, the link 21 is located outside the base 10, as shown in Figure 2 or 3. Positioning the link 21 outside the base 10 is advantageous in avoiding interference between the arm 2 and the base 10.

[0041] Furthermore, in a plan view of the articulated robot 1, the end effector 13 is positioned near the rotation axis of the base 10, i.e., the first axis Ax1. This is because the link 23, which is the link on the tip side of the arm 2, is positioned so as to overlap with the first axis Ax1. Positioning the end effector 13 near the first axis Ax1 is advantageous for the operation of the articulated robot 1.

[0042] Furthermore, by positioning the link 21 outside the base 10, an empty space 12 is formed on the side of the bracket 11. Since the link 23 can be positioned in the empty space 12, the articulated robot 1 can position the arm 2 closer to the base 10, as shown in FIG.

[0043] (Variation) In the articulated robot 1 shown in the figure, the links 21, 22, and 23 are positioned in order along the Y axis, from a position farther away from the first axis Ax1 to a position closer to the first axis Ax1. The links 21, 22, and 23 may also be positioned in order along the Y axis, from a position closer to the first axis Ax1 to a position farther away from the first axis Ax1. In other words, in the articulated robot 1, it is not essential that the link 23 be positioned at a position overlapping the first axis Ax1 along the Y axis.

[0044] Furthermore, the first end of the link 21 may be supported by the bracket 11 on the first axis Ax1 side across the bracket 11 in the Y-axis direction.

[0045] The articulated robot disclosed herein is not limited to a seven-axis robot, and may be, for example, an eight-axis robot.

[0046] (Aspect) The above-described embodiments are examples of the following aspects.

[0047] (Aspect 1) a base (10) having a joint (JT1) that rotates around a first axis (Ax1) extending in a first direction; a first link (21) supported by a bracket (11) of the base (10) and rotatable relative to the base (10) about a second axis (Ax2) extending in a second direction intersecting the first direction; a second link (23) that rotates around a third axis (Ax3) parallel to the second axis (Ax2); a third link (22) that is located between the first link (21) and the second link (23) in the second direction to connect the first link (21) and the second link (23), and that rotates at a first end (221) relative to the first link (21) around a fourth axis (Ax4) parallel to the second axis (Ax2) and the third axis (Ax3), and that rotates at a second end (222) relative to the second link (23) around the third axis (Ax3), Articulated robot (1).

[0048] The first link 21, the third link 22, and the second link 23 are arranged in this order in the second direction. The articulated robot 1 can fold the arm 2 so that the first link 21 and the third link 22 overlap.

[0049] (Aspect 2) The length L from the fourth axis (Ax4) of the third link (22) to the outermost edge of the second end (222) is shorter than the length L0 between the fourth axis (Ax4) and the second axis (Ax2). The articulated robot (1) according to embodiment 1.

[0050] Since the third link (22) is relatively short, interference between the third link (22) and the base (10) can be avoided when the arm (2) is folded.

[0051] (Aspect 3) The length L is shorter than the length L1 from the fourth axis (Ax4) to the edge of the bracket (11). The articulated robot (1) according to aspect 2.

[0052] Since the length L of the third link (22) is short, interference between the third link (22) and the bracket (11) is avoided.

[0053] (Aspect 4) the first link (21) is supported by the bracket (11) on the opposite side of the bracket (11) from the position of the first axis (Ax1) in the second direction; The articulated robot (1) according to any one of aspects 1 to 3.

[0054] Since the first link (21) is located outside the base (10), it is advantageous to avoid interference between the arm (2) and the base (10).

[0055] (Aspect 5) The second link (23) is positioned so as to overlap with the first axis (Ax1) in the second direction. The articulated robot (1) according to any one of aspects 1 to 4.

[0056] Since the second link (23), which is the link at the tip of the arm (2), is positioned so as to overlap with the first axis (Ax1), the end effector (13) of the articulated robot (1) is positioned close to the rotation axis of the base (10).

[0057] (Aspect 6) When the arm (2) including the first link (21), the second link (23), and the third link (22) is folded, the second link (23) is located in an empty space (12) on the side of the bracket (11) in the second direction. The articulated robot (1) according to any one of aspects 1 to 5.

[0058] Since the second link (23) can be positioned in the empty space (12), the articulated robot (1) can position the arm (2) at a position closer to the base (10).

[0059] (Aspect 7) When viewed along the second direction, the third link (22) is displaced to a position where a second center line (CL) connecting the third axis (Ax3) and the fourth axis (Ax4) of the third link (22) overlaps with a first center line (CL) connecting the second axis (Ax2) and the fourth axis (Ax4) of the first link (21). An articulated robot (1) according to any one of aspects 1 to 6.

[0060] The arm (2) can be folded until the first link (21) and the third link (22) overlap each other.

[0061] (Aspect 8) When viewed along the second direction, the third link (22) is displaced to an attitude in which the third axis (Ax3) is closer to the first axis (Ax1) than the first center line (CL). An articulated robot (1) according to embodiment 7.

[0062] Since the third link (22) moves even closer to the base (10), the articulated robot (1) can position the arm (2) at a position closer to the base (10).

[0063] (Aspect 9) When viewed along the second direction, the third link (22) is displaced to a position in which the third axis (Ax3) is closer to the first axis (Ax1) than the second axis (Ax2). An articulated robot (1) according to any one of aspects 1 to 8.

[0064] The articulated robot 1 can fold the arm (2) until the arm (2) approaches the base (10).

[0065] (Aspect 10) The total length (L23) of the second link (23) is longer than the total length (L22) of the third link (22). An articulated robot (1) according to any one of aspects 1 to 9.

[0066] Since the second link (23) is long, the articulated robot (1) can have an arm (2) with a long overall length.

[0067] (Aspect 11) Performing work on the workpiece (9); The articulated robot (1) according to any one of aspects 1 to 10.

[0068] The articulated robot (1) can perform tasks on a variety of workpieces (9).

[0069] (Aspect 12) It is a seven-axis robot. An articulated robot (1) according to any one of aspects 1 to 11.

[0070] The seven-axis articulated robot (1) can extend the arm (2) to position the tip of the arm (2) far away, and the seven-axis articulated robot (1) can fold the arm (2) to position the tip of the arm (2) close to the base (10). [Explanation of symbols]

[0071] 1. Articulated robot 10 base 11 Bracket 12 Free Space 2 Arms 21 Link (1st link) 22 Link (3rd Link) 221 First end 222 Second end 23 Link (2nd Link) 9 Work Ax1 1st axis Ax2 2nd axis Ax3 3rd axis Ax4 4th axis JT1 First joint CL 1st center line, 2nd center line

Claims

1. a base having a joint that rotates around a first axis extending in a first direction; a first link supported by a bracket of the base and rotatable relative to the base about a second axis extending in a second direction intersecting the first direction; a second link that rotates about a third axis parallel to the second axis; a third link located between the first link and the second link in the second direction to connect the first link and the second link, and rotatable at a first end relative to the first link around a fourth axis parallel to the second axis and the third axis, and rotatable at a second end relative to the second link around the third axis, Articulated robot.

2. The articulated robot according to claim 1, a length L from the fourth axis to the outermost edge of the second end of the third link is shorter than a length L0 between the fourth axis and the second axis; Articulated robot.

3. The articulated robot according to claim 2, The length L is shorter than the length L1 from the fourth axis to the edge of the bracket. Articulated robot.

4. The articulated robot according to any one of claims 1 to 3, the first link is supported by the bracket on a side opposite to the position of the first axis across the bracket in the second direction; Articulated robot.

5. The articulated robot according to any one of claims 1 to 3, the second link is positioned at a position overlapping with the first axis in the second direction; Articulated robot.

6. The articulated robot according to any one of claims 1 to 3, When an arm including the first link, the second link, and the third link is folded, the second link is located in an empty space on a side of the bracket in the second direction. Articulated robot.

7. The articulated robot according to any one of claims 1 to 3, the third link is displaced to a position where, when viewed along the second direction, a second center line connecting the third axis and the fourth axis of the third link overlaps with a first center line connecting the second axis and the fourth axis of the first link. Articulated robot.

8. The articulated robot according to claim 7, the third link is displaced to a position in which the third axis is closer to the first axis than the first center line when viewed along the second direction; Articulated robot.

9. The articulated robot according to claim 1, the third link is displaced to a position in which the third axis is closer to the first axis than the second axis when viewed along the second direction; Articulated robot.

10. The articulated robot according to claim 1, The total length of the second link is longer than the total length of the third link. Articulated robot.

11. The articulated robot according to claim 1, Performing work on the workpiece, Articulated robot.

12. The articulated robot according to claim 1, It is a seven-axis robot. Articulated robot.

Images