robot

Abstract

To reduce weight while ensuring stiffness.SOLUTION: A robot is equipped with a base, a swiveling base, a lower arm, and an upper arm. The base is fixed to an installation surface. The swiveling base is supported on an upper surface side of the base on a base end side, and swivels around a first axis along a vertical direction. The lower arm includes a first extending portion, a second extending portion, and a hollow coupling portion. The first extending portion extends in a direction connecting a second axis and a third axis. The second extending portion opposes to the first extending portion at an interval and extends in the same direction as the first extending portion. The hollow coupling portion couples the first extending portion and the second extending portion between the second axis and the third axis. The coupling portion has a reinforcing portion in which a plurality of ribs connecting opposing inner walls of the coupling portion intersect in a view of the extending direction of the coupling portion.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The disclosed embodiments relate to robots.

Background Art

[0002] Conventionally, robots that drive and operate multiple joint parts respectively are known. An end effector suitable for applications such as welding and gripping is attached to the tip of such a robot, and various operations such as workpiece processing and movement are performed.

[0003] Also, a robot has been proposed that has an arm in which a plate-shaped main structure part and a plate-shaped auxiliary structure part having a smaller plate thickness than the main structure part face each other with a gap therebetween. Here, the main structure part and the auxiliary structure part are connected by a connecting part that extends so as to connect the two (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, from the viewpoint of achieving weight reduction while ensuring rigidity, there is room for improvement in the above-described arm.

[0006] One aspect of the embodiment aims to provide a robot having an arm that can achieve weight reduction while ensuring rigidity.

Means for Solving the Problems

[0007] A robot according to one embodiment comprises a base, a swivel base, a lower arm, and an upper arm. The base is fixed to the mounting surface. The swivel base is supported at its base end on the upper surface of the base and swivels around a first axis that is aligned vertically. The lower arm has a bifurcated shape at both its tip end and base end, with its base end supported so as to sandwich the tip end of the swivel base, and swivels around a second axis perpendicular to the first axis. The upper arm is supported at its base end so as to be sandwiched between the tip end of the lower arm, and swivels around a third axis parallel to the second axis. The lower arm includes a first extension, a second extension, and a hollow connecting portion. The first extension extends in a direction connecting the second axis and the third axis. The second extension faces the first extension at a distance and extends in the same direction as the first extension. The hollow connecting portion connects the first extended portion and the second extended portion between the second axis and the third axis. The connecting portion has a reinforcing portion in which a plurality of ribs intersect, connecting the opposing inner walls of the connecting portion when viewed in the direction of extension of the connecting portion. [Effects of the Invention]

[0008] According to one embodiment, it is possible to provide a robot having an arm that can be made lighter while ensuring rigidity. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a side view of the robot according to this embodiment. [Figure 2] Figure 2 is a rear view of the robot. [Figure 3] Figure 3 is a side view of the first extension. [Figure 4] Figure 4 is a front view of the first extension. [Figure 5] Figure 5 is a side view of the second extension. [Figure 6] Figure 6 is a front view of the second extension. [Figure 7] Figure 7 is a block diagram showing the configuration of the robot system. [Modes for carrying out the invention]

[0010] The embodiments of the robot disclosed herein will be described in detail below with reference to the attached drawings. However, the present invention is not limited to the embodiments described below.

[0011] Furthermore, in the embodiments described below, expressions such as "vertical," "orthogonal," or "vertical" are used, but it is not necessary to strictly satisfy these conditions. In other words, each of the above expressions allows for deviations in manufacturing accuracy, installation accuracy, processing accuracy, detection accuracy, etc.

[0012] First, the robot 10 according to the embodiment will be described using Figure 1. Figure 1 is a side view of the robot 10 according to the embodiment. In Figure 1, for the sake of clarity, a three-dimensional orthogonal coordinate system including the Z-axis with the vertically upward direction as the positive direction is shown. Such an orthogonal coordinate system may also be shown in other drawings used in the following description. Note that "orthogonal" means that they are both "perpendicular" to each other and "intersect".

[0013] As shown in Figure 1, the robot 10 comprises a base 10b, a first arm 11, a second arm 12, a third arm 13, a fourth arm 14, a fifth arm 15, and a sixth arm 16. In the following description, the first arm 11 will be referred to as the swivel base 11, the second arm 12 as the lower arm 12, and the third arm 13 as the upper arm 13.

[0014] Here, Figure 1 shows the robot 10 in a position where the lower arm 12 is rotated vertically and the upper arm 13 is rotated horizontally. In the following description, in the position of the robot 10 shown in Figure 1, the positive Y-axis direction will be referred to as the back of the robot 10, and the negative Y-axis direction will be referred to as the front of the robot 10.

[0015] The base 10b is fixed to the installation surface IS. The swivel base 11 is supported at its proximal end on the upper surface side of the base 10b and pivots about the first axis A1 along the vertical direction. Here, "pivot" refers to an operation of changing the angle formed by adjacent arms. Also, "revolution" refers to an operation of rotating relatively torsionally without changing the angle formed by adjacent arms. Note that it can also be said that "pivot" refers to an operation of swinging an arm around a rotation axis, and "revolution" refers to an operation of rotating an arm around a rotation axis along the extending direction of the arm. In this embodiment, as described above, "pivot" and "revolution" are used properly. However, depending on the shape of the robot arm, the position and orientation of the joint axis, there are forms that can be called either "pivot" or "revolution". Therefore, the operations of the robot's rotary joints may be collectively referred to as "revolution".

[0016] The lower arm 12 is bifurcated at both the distal end side and the proximal end side, and the proximal end side is supported so as to sandwich the distal end side of the swivel base 11, and pivots about the second axis A2 perpendicular to the first axis A1. The upper arm 13 is supported at its proximal end so as to be sandwiched by the distal end side of the lower arm 12, and pivots about the third axis A3 parallel to the second axis A2.

[0017] The fourth arm 14 is supported at its proximal end on the distal end side of the upper arm 13 and rotates about the fourth axis A4 perpendicular to the third axis A3. The fifth arm 15 is supported at its proximal end on the distal end side of the fourth arm 14 and pivots about the fifth axis A5 orthogonal to the fourth axis A4. The sixth arm 16 is supported at its proximal end on the distal end side of the fifth arm 15 and rotates about the sixth axis A6 orthogonal to the fifth axis A5. Note that various end effectors can be attached to and detached from the distal end side of the sixth arm 16.

[0018] Here, the configuration of the lower arm 12 will be described in more detail using the enlarged view S1 shown in FIG. 1. The enlarged view S1 corresponds to a view of the lower arm 12 in the posture shown in FIG. 1 seen from the positive Y-axis direction shown in FIG. 1.

[0019] As shown in the enlarged view S1, the lower arm 12 includes a first extension portion 100, a second extension portion 200, and a connecting portion 300. The first extension portion 100 extends in the direction connecting the second axis A2 and the third axis A3, that is, in the direction along the Z axis. Further, the second extension portion 200 faces the first extension portion 100 with a gap therebetween and extends in the same direction as the first extension portion 100, that is, in the direction along the Z axis. That is, the second extension portion 200 faces the second axis A2 and the third axis A3 with a gap in the axial direction.

[0020] The connecting portion 300 has a hollow structure and connects the first extension portion 100 and the second extension portion 200 between the second axis A2 and the third axis A3. Here, the hollow connecting portion 300 has a reinforcing portion 312 where a plurality of ribs connecting the opposing inner walls of the hollow connecting portion 300 intersect in the direction of view along the extending direction of the connecting portion 300, that is, the X axis (see the side view of the robot 10 shown in FIG. 1). The detailed configuration of the reinforcing portion 312 will be described later using FIGS. 3 and 4.

[0021] Thus, the lower arm 12 has a hollow connecting portion 300 that connects the first extension portion 100 and the second extension portion 200. Further, the connecting portion 300 has a reinforcing portion 312 that connects the opposing inner walls in the hollow portion of the connecting portion 300 in the direction of view along the X axis.

[0022] Specifically, the reinforcing portion 312 includes a plurality of ribs connecting the opposing inner walls of the hollow connecting portion 300 in the direction of view along the X axis, and the plurality of ribs intersect while being integrated with each other.

[0023] Thus, by making the connecting portion 300 hollow and providing the connecting portion 300 with the reinforcing portion 312, it is possible to achieve weight reduction while ensuring the rigidity of the entire lower arm 12. Further, if such a lower arm 12 is used, it is possible to achieve weight reduction while ensuring the rigidity of the entire robot 10.

[0024] Next, the configuration of the robot 10 shown in Figure 1 will be explained in more detail using Figure 2. Figure 2 is a rear view of the robot 10. As shown in Figure 2, the lower arm 12 has a bifurcated shape at both its tip and base ends. The base end has a shape that grips the tip end of the slewing base 11, while the tip end has a shape that grips the base end of the upper arm 13.

[0025] Here, a drive unit M is built into the tip of the slewing base 11. Since this drive unit M drives the second axis A2, it will be denoted with the axis number, such as drive unit M2. The same notation will be applied to the drive units M for the other axes.

[0026] Furthermore, a power transmission mechanism T, such as a reduction gear, which transmits the driving force of the drive unit M2, is connected to the base end of the first extension portion 100 of the lower arm 12. Since this power transmission mechanism T transmits the driving force that drives the second shaft A2, it will be described as power transmission mechanism T2, with the shaft number added to its reference numeral. The same description will be applied to power transmission mechanisms T for other shafts.

[0027] Furthermore, a drive unit M3 is built into the base end of the upper arm 13. A power transmission mechanism T3, which transmits the driving force of the drive unit M3, is connected to the tip end of the first extension portion 100 of the lower arm 12.

[0028] Thus, the drive unit M and the power transmission mechanism T are connected to the first extension portion 100. On the other hand, the drive unit M and the power transmission mechanism T are not connected to the second extension portion 200. Therefore, in the robot 10 according to this embodiment, the material of the first extension portion 100 in the lower arm 12 is made of a material with a larger Young's modulus than the material of the second extension portion 200.

[0029] For example, the first stretched portion 100 can be made of cast iron, such as spheroidal graphite cast iron. The second stretched portion 200 can be made of aluminum die-cast using an aluminum alloy. If the Young's modulus of the first stretched portion 100 is greater than that of the second stretched portion 200, the combination of materials for each stretched portion may be any other combination of materials.

[0030] In this way, by using a material with a higher Young's modulus for the first extension portion 100 of the lower arm 12 than the material for the second extension portion 200, the rigidity of the first extension portion 100, to which the drive unit M and the power transmission mechanism T are connected, can be ensured. Furthermore, by making the first extension portion 100 the part that primarily contributes to the rigidity of the lower arm 12, while making the second extension portion 200 a part that contributes to rigidity in an auxiliary way, with an emphasis on being lighter than rigidity, the overall weight of the lower arm 12 can be reduced.

[0031] Furthermore, as shown in Figure 2, the connecting portion 300 comprises a hollow first connecting portion 310 integrated with the first extension portion 100, and a hollow second connecting portion 320 integrated with the second extension portion 200. In other words, the first connecting portion 310 is integrally molded from the same material as the first extension portion 100, and the second connecting portion 320 is integrally molded from the same material as the second extension portion 200.

[0032] In other words, the connecting portion 300 is a collective term for the hollow first connecting portion 310 integrated with the first extension portion 100 and the hollow second connecting portion 320 integrated with the second extension portion 200. The first connecting portion 310 and the second connecting portion 320 are connected so that their hollow portions are in communication with each other. The reinforcing portion 312 shown in Figure 1 is provided on the first connecting portion 310. Details of the reinforcing portion 312 will be described later using Figures 3 and 4.

[0033] In the following, the first extension section 100 and the first connecting section 310 may be collectively referred to as the first extension section 100, and the second extension section 200 and the second connecting section 320 may be collectively referred to as the second extension section 200.

[0034] In this way, by providing the reinforcing portion 312 on the first connecting portion 310 which is integrated with the first extension portion 100, the natural frequencies of the first extension portion 100, which is the part that mainly bears the rigidity of the lower arm 12, can be increased for vibration modes such as bending in the X direction (first vibration mode) and bending in the Y direction (second vibration mode). Furthermore, the rigidity of the first extension portion 100 can be ensured, and consequently, the rigidity of the lower arm 12 as a whole can be ensured.

[0035] Here, if we define the amount of protrusion of the first connecting portion 310 protruding from the first extension portion 100 as "L1" and the amount of protrusion of the second connecting portion 320 protruding from the second extension portion 200 as "L2", then the relationship between the two is "L2 > L1".

[0036] In other words, the length of the first connecting portion 310 along the extension direction (length along the X-axis) is shorter than the length of the second connecting portion 320 along the extension direction (length along the X-axis). By doing this, the volume of the first extension portion 100 can be reduced compared to when the connecting portion 300 is equally divided along the extension direction. That is, the volume of the first extension portion 100, which often has a higher specific gravity because its Young's modulus is larger than that of the second connecting portion 320, can be reduced. Therefore, the overall weight of the lower arm 12 can be reduced.

[0037] Next, the first extension portion 100 shown in Figure 2 will be described in more detail using Figures 3 and 4. Figure 3 is a side view of the first extension portion 100, and Figure 4 is a front view of the first extension portion 100. Note that Figure 3 corresponds to a view from the same direction as Figure 2 (viewed from the positive Y-axis direction), and Figure 4 corresponds to a view from the side where the first connecting portion 310 protrudes, that is, a view from the side of the second extension portion 200 shown in Figure 2 (viewed from the positive X-axis direction).

[0038] As shown in Figure 3, the first extension portion 100 has a hollow portion 120 that communicates with the surface opposite to the surface facing the second extension portion 200 shown in Figure 2 (hereinafter sometimes referred to as the "inner surface") (hereinafter sometimes referred to as the "outer surface") at the tip side and the base end side, respectively.

[0039] In this way, by providing hollow sections 120 in the first extension section 100, the weight of the first extension section 100 can be reduced. Each hollow section 120 extends from the hollow first connecting section 310 side toward each end along the extension direction of the first extension section 100 and communicates with the outer surface of the first extension section 100. Although two hollow sections 120 are shown in Figure 3, the number of hollow sections 120 may be one or three or more. Through holes 101 are provided at the tip and base ends of the first extension section 100, penetrating in a direction along the X-axis. The through holes 101 are used for mounting the power transmission mechanism T (T2 and T3) shown in Figure 2.

[0040] Here, the first extension portion 100 is equipped with covers 150 that cover the outer surfaces of the tip end and the base end, respectively. Each cover 150 covers the through hole 101 and the communication opening to each hollow portion 120, respectively. By covering the above-mentioned communication openings with the covers 150, it is possible to prevent dust, water, etc. from entering the inside of the first extension portion 100 and to give the surface of the arm a smooth shape.

[0041] Furthermore, the material of the cover 150 may be the same as that of the first extended section 100, but it can also be made of a lightweight material such as resin. By using a lightweight cover 150, the overall weight of the first extended section 100 can be reduced.

[0042] Furthermore, ribs may be formed on the surface of the first extended portion 100 covered by the cover 150 by providing, for example, a convex or concave shape that extends in the direction of extension of the first extended portion 100. Also, the direction of extension of the ribs may be different from the direction of extension of the first extended portion 100, or multiple directions may be combined.

[0043] In this way, by forming ribs in the direction and parts where rigidity is to be maintained according to the specific shape of the first extension portion 100, while reducing the thickness of other parts, it is possible to reduce the weight of the first extension portion 100 while maintaining its rigidity. In addition, by covering the surface irregularities with the cover 150, the outer shape of the first extension portion 100 can be made smoother.

[0044] Furthermore, as shown in Figure 3, the hollow first connecting portion 310 is provided with an outer wall 311 that protrudes from the inner surface of the first extension portion 100 so as to surround the hollow portion. In addition, the bottom surface 110 of the hollow portion of the first connecting portion 310 is closer to the outer surface than the inner surface of the first extension portion 100 excluding the first connecting portion 310.

[0045] In this way, the first extended portion 100 can be made thinner, and the weight of the first extended portion 100 can be reduced. The position of the bottom surface 110 may be aligned with the position of the inner surface of the first extended portion 100, or it may be positioned to protrude from the inner surface of the first extended portion 100.

[0046] Furthermore, as shown in Figure 3, the first connecting portion 310 includes a reinforcing portion 312 that protrudes from the inner wall of the outer wall 311 and connects the inner walls of the outer wall 311 together. Here, the reinforcing portion 312 is provided in a position closer to the second connecting portion 320 shown in Figure 2 than to the inner surface of the first extension portion 100.

[0047] In this way, by positioning the reinforcing portion 312 at a location shifted from the extending portion of the first extending portion 100 in the direction of extension (along the Z-axis) to the front side (positive X-axis side), the natural frequency of the bending (first vibration mode) in the X direction of the first extending portion 100 can be increased.

[0048] Here, the configuration of the reinforcing section 312 will be explained in more detail using Figure 4. As shown in Figure 4, when the first extension section 100 is viewed from the side of the second extension section 200 shown in Figure 2, the shape of the first connecting section 310 is a hollow rectangle. From the inner wall of the rectangularly connected outer wall 311, ribs protrude, connecting the diagonals of the rectangle, and the parts where each rib intersects with each other are integrated. In addition, from the viewpoint of suppressing interference with other arms, at least one corner of the rectangularly connected outer wall 311 may be rounded (R-shaped).

[0049] As shown in Figure 4, the bottom surface 110 shown in Figure 3 can be seen through the ribs. In other words, the reinforcing portion 312 has cavities between each rib that connect the hollow portion near the bottom surface 110 to the outside. By making the reinforcing portion 312 a rib shape with intersecting ribs and creating cavities between the ribs, it becomes possible to discharge sand molds and other materials used during casting through these cavities. Therefore, the first connecting portion 310 and the first extension portion 100 are shaped to facilitate integral casting. In the state before the installation of the power transmission mechanism T (T2 and T3) shown in Figure 2, the inner surface of the cover 150 shown in Figure 3 can be seen through the through hole 101.

[0050] Furthermore, in the view shown in Figure 4, the shape of the reinforcing portion 312 may be different from the shape shown in Figure 4, provided that the above-mentioned cavity is present. For example, the ribs connecting the midpoints of the opposing inner walls in the hollow, rectangular first connecting portion 310 may be combined with ribs connecting the diagonals, or they may be used instead of ribs connecting the diagonals. Note that the arrangement and number of ribs described above are just examples and do not limit the arrangement or number of each rib.

[0051] Furthermore, regarding the extension direction of the first connecting portion 310, multiple reinforcing portions 312 may be provided at intervals from one another. Also, when multiple reinforcing portions 312 are provided, the shape of each reinforcing portion 312 may be different.

[0052] In Figure 4, the width of the first connecting portion 310 in the direction along the Y-axis is shown to be the same as the width of the extended portion of the first extension portion 100. However, the width of the first connecting portion 310 may be made smaller than the width of the first extension portion 100. Also, as shown by the dashed line in Figure 4, ribs for attaching the cover 150 are formed on the outer surface of the first extension portion 100 so as to surround the through hole 101 and protrude toward the cover 150 along the outer shape of the first extension portion 100. Here, in the side view shown in Figure 3, the through hole 101 and the hollow portion 120 are not directly connected (they are indirectly connected via the space inside the cover 150). However, the through hole 101 and the hollow portion 120 may be directly connected in the direction of extension of the first extension portion 100.

[0053] Next, the second extension portion 200 shown in Figure 2 will be described in more detail using Figures 5 and 6. Figure 5 is a side view of the second extension portion 200, and Figure 6 is a front view of the second extension portion 200. Note that Figure 5 corresponds to a view from the same direction as Figure 2 (viewed from the positive Y-axis direction), and Figure 6 corresponds to the surface from which the second connecting portion 320 protrudes, that is, a view from the first extension portion 100 side shown in Figure 2 (viewed from the negative X-axis direction).

[0054] As shown in Figure 5, the second extension portion 200 is provided with a cover 250 that covers the surface opposite to the surface facing the first extension portion 100 shown in Figure 2 (hereinafter sometimes referred to as the "inner surface") (hereinafter sometimes referred to as the "outer surface"). In Figure 5, a cover 250 that covers the entire outer surface of the second extension portion 200 is shown, but the cover 250 may cover at least a part of the outer surface, or multiple covers 250 that cover the outer surface may be provided.

[0055] Here, the cover 250 has a shape that forms a space between it and the outer surface of the second extension 200. Therefore, a wire such as a cable or hose can be routed in this space. In other words, a wire such as a cable can be routed inside the second extension 200.

[0056] Furthermore, the material of the cover 250 may be the same as that of the second extension section 200, but it can also be made of a lightweight material such as resin. By using a lightweight material for the cover 250, the overall weight of the second extension section 200 can be reduced.

[0057] Furthermore, as shown in Figure 5, the hollow second connecting portion 320 is provided with an outer wall 321 that protrudes from the inner surface of the second extension portion 200 so as to surround the hollow portion. The hollow portion of the second connecting portion 320 penetrates in a direction along the X axis, and the outer surface of the second extension portion 200 is covered by the cover 250.

[0058] Here, the space covered by the cover 250 in the extended portion of the second extension 200 is in communication with the hollow portion of the second connecting portion 320. Furthermore, through holes 201 are provided at the tip and base ends of the second extension 200, extending in a direction along the X-axis. Therefore, by passing through these through holes 201, a wire such as a cable, which passes through the swivel base 11 and upper arm 13 shown in Figure 2, can be routed into the space within the second extension 200.

[0059] Next, the shape of the second connecting portion 320 will be described. As shown in Figure 6, when the second extension portion 200 is viewed from the side of the first extension portion 100 shown in Figure 2, the shape of the second connecting portion 320 is a hollow rectangle. In other words, the second extension portion 200 has an outer wall 321 that is connected in a rectangular shape. The inner surface of the cover 250 shown in Figure 5 can be seen from the hollow portion and through hole 201 of the second extension portion 200. As shown by the dashed line in Figure 6, a rib for attaching the cover 250 is formed on the outer surface of the second extension portion 200, projecting toward the cover 250 along the outer circumference of the second extension portion 200.

[0060] Here, as shown in Figure 6, the thickness of the outer wall 321 differs between the side of the second extension 200 in the direction of extension (along the Z-axis) and the side that intersects with this extension direction. Specifically, if the thickness of the side that intersects with the extension direction is "T2" and the thickness of the side along the extension direction is "T1", then the relative size of the two is "T2 <T1」である。

[0061] In this way, the thickness of the outer wall 321 in the part that is less likely to affect the reduction in the natural frequency of the natural vibration mode of the lower arm 12 as a whole is made thinner than the thickness of the outer wall 321 in the part that is more likely to affect it. Therefore, it is possible to reduce the weight of the second extension part 200 while suppressing the reduction in the natural frequency of the natural vibration mode.

[0062] In Figure 6, the width of the second connecting portion 320 in the direction along the Y-axis is shown to be the same as the width of the extended portion of the second extension portion 200. However, the width of the second connecting portion 320 may be made smaller than the width of the second extension portion 200.

[0063] Next, the configuration of the robot system 1 will be explained using Figure 7. Figure 7 is a block diagram showing the configuration of the robot system 1. As shown in Figure 7, the robot system 1 comprises a robot 10 and a controller 500. The robot 10 is connected to the controller 500.

[0064] First, the robot 10 has already been explained using Figure 1, etc., so its explanation will be omitted here. The controller 500 comprises a control unit 510 and a storage unit 520. The control unit 510 comprises an motion control unit 511. The storage unit 520 stores the teaching information 521.

[0065] Here, the controller 500 includes, for example, a computer and various circuits having a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), HDD (Hard Disk Drive), input / output ports, etc.

[0066] The computer's CPU functions as the operation control unit 511 of the control unit 510, for example, by reading and executing a program stored in ROM. The operation control unit 511 can also be configured using hardware such as an ASIC (Application Specific Integrated Circuit) or FPGA (Field Programmable Gate Array).

[0067] Furthermore, the storage unit 520 can be, for example, RAM or HDD. RAM or HDD can store the teaching information 521. The controller 500 may also acquire the above-mentioned programs and various information via other computers or portable recording media connected by a wired or wireless network. In addition, the controller 500 may be configured as multiple devices that can communicate with each other, or as a hierarchical device that can communicate with higher or lower level devices.

[0068] The control unit 510 controls the movement of the robot 10. If the controller 500 consists of multiple units, the control unit 510 also performs synchronization between the controllers 500. The motion control unit 511 operates the robot 10 based on the teaching information 521. The motion control unit 511 improves the accuracy of the robot 10's movement by performing feedback control using encoder values ​​from actuators (not shown), which are the power sources of the robot 10.

[0069] The teaching information 521 is created during the teaching phase in which the robot 10 is taught an action, and includes information that defines the robot 10's movement path, known as a "job". Although Figure 7 shows one robot 10 and one controller 500, it is also possible to use multiple robots 10 or multiple controllers 500.

[0070] As described above, the robot 10 according to one embodiment comprises a base 10b, a swivel base 11, a lower arm 12, and an upper arm 13. The base 10b is fixed to the mounting surface IS. The swivel base 11 is supported at its base end on the upper surface of the base 10b and swivels around a first axis A1 that is aligned vertically. The lower arm 12 has a bifurcated shape at both its tip end and base end, and its base end is supported so as to sandwich the tip end of the swivel base 11, and it swivels around a second axis A2 that is perpendicular to the first axis A1. The upper arm 13 is supported at its base end so as to be sandwiched between the tip end of the lower arm 12, and it swivels around a third axis A3 that is parallel to the second axis A2.

[0071] The lower arm 12 includes a first extension portion 100, a second extension portion 200, and a hollow connecting portion 300. The first extension portion 100 extends in a direction connecting the second axis A2 and the third axis A3. The second extension portion 200 faces the first extension portion 100 at a distance and extends in the same direction as the first extension portion 100. The hollow connecting portion 300 connects the first extension portion 100 and the second extension portion 200 between the second axis A2 and the third axis A3. The connecting portion 300 has a reinforcing portion 312 in which a plurality of ribs connecting the opposing inner walls of the connecting portion 300 intersect when viewed in the direction of extension of the connecting portion 300.

[0072] Thus, the lower arm 12 of the robot 10 has a hollow connecting portion 300 that connects the first extension portion 100 and the second extension portion 200, and a reinforcing portion 312 where multiple ribs intersect to connect the opposing inner walls of the connecting portion 300. Therefore, the rigidity of the lower arm 12 can be ensured while reducing its weight. Consequently, the robot 10 equipped with such a lower arm 12 can be made lighter while ensuring its rigidity.

[0073] In the embodiment described above, a so-called 6-axis robot 10 was shown, but the number of axes of the robot may be 5 axes or less, or 7 axes or more. Also, in the embodiment described above, the lower arm 12, which is the second arm of the robot 10, was shown to have a configuration comprising a first extension portion 100, a second extension portion 200, and a hollow connecting portion 300, but other configurations for the arms may also be applied.

[0074] Further effects and modifications can be readily derived by those skilled in the art. Therefore, broader embodiments of the present invention are not limited to the specific details and representative examples expressed and described above. Accordingly, various modifications are possible without departing from the spirit or scope of the overall concept of the invention as defined by the appended claims and their equivalents. [Explanation of Symbols]

[0075] 1. Robot System 10 Robots 10b Base 11. Swivel base (first arm) 12. Lower arm (2nd arm) 13. Upper arm (3rd arm) 14. Fourth Arm 15. Fifth Arm 16. Arm 6 100 1st stretching section 101 Through hole 110 Base 120 Hollow part 150 Cover 200 2nd stretching section 201 Through hole 250 Cover 300 Connection section 310 1st connection part 311 Exterior Wall 312 Reinforcement section 320 2nd connection part 321 Exterior Wall 500 Controllers 510 Control Unit 511 Operation Control Unit 520 Storage section 521 Instructional Information A1 First Axis A2 2nd axis A3 3rd axis A4 4th axis A5 5th axis A6 6th axis M Drive Unit T Power Transmission Mechanism

Claims

1. A base that is fixed to the mounting surface, The base end is supported on the upper surface of the aforementioned base, and the pivot base rotates around a first axis aligned vertically, The lower arm has a bifurcated shape at both the tip and base ends, with the base end supporting the tip end of the pivot base, and pivots around a second axis perpendicular to the first axis. The base end of the upper arm is supported so as to be sandwiched between the tip end of the lower arm, and the upper arm rotates around a third axis parallel to the second axis. Equipped with, The aforementioned lower arm is A first extension portion extending in the direction connecting the second axis and the third axis, A second extension portion is positioned opposite the first extension portion at a distance from it and extends in the same direction as the first extension portion. A hollow connecting portion that connects the first extended portion and the second extended portion between the second shaft and the third shaft. Includes, The aforementioned connecting portion is In a view of the connecting portion in the direction of extension, the connecting portion has a reinforcing portion where multiple ribs intersect to connect the opposing inner walls of the connecting portion. A robot characterized by the following.

2. The first extension is, The drive unit and power transmission mechanism are connected, and the material has a higher Young's modulus than the material of the second extension unit. The robot according to claim 1, characterized in that

3. The aforementioned connecting portion is A hollow first connecting portion integrated with the first extension portion, A hollow second connecting portion integrated with the second extension portion and Equipped with, The first connecting portion is, Connected to the aforementioned second connecting portion, The aforementioned reinforcing portion is To be provided in the first connecting portion The robot according to claim 2, characterized in that

4. The first connecting portion is, The length of the connecting portion along the extending direction is shorter than that of the second connecting portion. The robot according to claim 3, characterized by the following:

5. The aforementioned reinforcing portion is The first extension portion is provided in a position closer to the second connecting portion than to the surface facing the second extension portion. The robot according to claim 3, characterized by the following:

6. The second connecting portion is, The thickness of the outer wall intersecting the extension direction of the second extension is smaller than the thickness of the outer wall along the extension direction. The robot according to claim 3, characterized by the following:

7. The first extension is, The second extension portion has a hollow portion in a location other than the first connecting portion that communicates with the surface opposite to the surface facing the second extension portion. The robot according to claim 3, characterized by the following:

8. The second extension portion is, The cover comprises a cover that covers at least a portion of the surface opposite to the surface facing the first extension, The aforementioned cover is To form a space between the opposite surface. The robot according to claim 3, characterized by the following:

Images