JP7492822B2 - Industrial Robots - Google Patents

Description

The present invention relates to an industrial robot with multiple connected arms.

As a conventional industrial robot of this type, Patent Document 1 proposes an industrial robot that includes a lower arm whose base end is pivotally attached to a base, an upper arm pivotally attached to the tip of the lower arm, and a support arm pivotally attached to the tip of the upper arm.

The upper arm has a cable arranged along the rotation axis along the longitudinal direction, and by arranging the cable so that it is parallel to the arm body of the upper arm, the cable is exposed from the upper arm. This makes it possible to attach the cable to the upper arm.

JP 2014-136280 A

However, in the industrial robot described in Patent Document 1, the arm body is positioned offset from the rotation axis of the upper arm to allow the cable to escape. Therefore, it is expected that the strength of the arm body cannot be sufficiently ensured.

Therefore, in the industrial robot of Patent Document 1, a cylindrical support part is provided on the base end side of the arm body, but when such a cylindrical support part is provided, the cable ends up being inserted into the cylindrical support part. This makes the cable arrangement work complicated, even though the cable is exposed from the upper arm.

The present invention was made in consideration of these points, and its purpose is to provide an industrial robot with a structure that ensures the strength of the upper arm while making it easy to place cables on the upper arm.

In view of the above problem, the industrial robot of the present invention is an industrial robot including a lower arm whose base end is pivotally attached to a base, an upper arm pivotally attached to the tip of the lower arm, a support arm pivotally attached to the tip of the upper arm, and at least a cable arranged on the upper arm, wherein the upper arm includes a joint portion pivotally attached to the tip of the lower arm and an arm portion attached to the joint portion so as to be rotatable about a rotation axis along the longitudinal direction of the upper arm, the cable is arranged along the longitudinal direction, a pivot motor that pivots the support arm relative to the upper arm is fixed to the arm portion at a position offset from the rotation axis, the arm portion is formed at the base end of the arm portion with an insertion portion through which the cable is inserted, and an arm body extending from the insertion portion so as to be arranged in parallel with the cable, and the arm portion is formed with a first reinforcing rib that protrudes from the arm body so as to surround the pivot motor at a position opposite to the cable across the pivot motor.

According to the present invention, the cable is arranged along the longitudinal direction of the upper arm, and the arm body extends so as to be arranged in parallel with the cable. Here, if the insertion portion through which the cable is inserted at the base end side of the arm body is, for example, ring-shaped, the cable can be exposed to the outside from the upper arm over a wider range.

According to the present invention, the arm portion is formed with a first reinforcing rib that surrounds the pivot motor on the opposite side of the cable, sandwiching the pivot motor, so that the first reinforcing rib protects the pivot motor and increases the rigidity of the arm portion. In addition, an open space that exposes the cable can be formed on the opposite side of the cable from the position where the first reinforcing rib is formed, so that a larger space can be secured for arranging the cable on the upper arm.

In a more preferred embodiment, the first reinforcing rib extends from the insertion portion toward the tip side of the arm body. According to this embodiment, the first reinforcing rib can suppress bending of the arm body along the longitudinal direction. In particular, when an end effector is attached to the support arm, a bending moment is likely to act on the base end of the arm body, but by providing the first reinforcing rib, the bending rigidity along the longitudinal direction of the arm portion can be increased, and the strength of the arm portion can be ensured.

In a more preferred embodiment, a second reinforcing rib is formed extending from the arm body so as to face the first reinforcing rib across the cable, at least on the insertion portion side of the position where the pivot motor is fixed.

According to this aspect, the second reinforcing rib and a part of the first reinforcing rib protrude from the arm body at least on the insertion part side of the position where the pivot motor is fixed. As a result, the shape of the arm part at least on the insertion part side of the position where the pivot motor is fixed is a shape like a peripheral wall of a cylindrical part being cut off. With this shape, the strength of the base end side of the arm part can be increased by the first reinforcing rib and the second reinforcing rib, and an open space for cable placement work can be secured between the first reinforcing rib and the second reinforcing rib. Furthermore, if the second reinforcing rib is not formed on the tip side of the arm body from the position where the pivot motor is fixed, not only is it easier to expose the cable, but it is also easier to layout other equipment on the tip side of the arm body.

In a further preferred embodiment, the first reinforcing rib protrudes more than the second reinforcing rib. According to this embodiment, in the section along the longitudinal direction of the arm body, at the position where the pivot motor is fixed, the pivot motor is not present on the second reinforcing rib side of the cable, so it is easy to secure space for cable placement work from the second reinforcing cable side.

In a further preferred embodiment, the first reinforcing rib protrudes less from the arm body toward the tip of the arm body. According to this embodiment, it is possible to reduce the weight of the first reinforcing rib at the tip side of the arm body, while reducing the bending of the arm body along the longitudinal direction at the base end side of the arm body. Furthermore, at the tip side of the arm body, the cable is easily visible from the first reinforcing rib side, making it easy to perform cable placement work.

The present invention makes it possible to easily arrange cables on the upper arm while ensuring the strength of the upper arm.

1 is a perspective view of an industrial robot according to an embodiment of the present invention, as viewed from the front side. FIG. FIG. 2 is a perspective view of the industrial robot shown in FIG. 1 as viewed from the rear side. FIG. 2 is a perspective view of the industrial robot according to the embodiment of the present invention as viewed from the other side of FIG. 1 FIG. 4 is a side view of the upper arm shown in FIG. 3 . FIG. 5 is an enlarged perspective view of the upper arm shown in FIG. 4 . 6 is an enlarged perspective view of the upper arm shown in FIG. 5 as viewed from below. FIG. FIG. 6 is an enlarged perspective view of a main portion of the upper arm shown in FIG. 5 .

Below, an industrial robot 1 (hereinafter referred to as robot 1) according to an embodiment of the present invention will be described in detail with reference to Figures 1 to 7.

As shown in Figures 1 and 2, the robot 1 has an end effector, such as a gripping device or welding device, attached to its tip.

1. Overall Structure of Robot 1 The robot 1 is a manipulator. The robot 1 includes a control device (not shown) that controls each motor and the like, and the operation of the robot 1 is controlled by the control device.

The robot 1 has a base 11, which is installed on an installation surface. The base 11 has a fixed base 11a fixed to the installation surface, and a swivel base 11b that rotates around a first axis J1 along a direction perpendicular to the installation surface. The output shaft (not shown) of the first motor 40A is connected to the swivel base 11b. This allows the swivel base 11b to pivot around the first axis J1 relative to the fixed base 11a.

The robot 1 has a lower arm 12 whose base end is pivotally attached to a base 11, an upper arm 20 pivotally attached to the tip of the lower arm 12, and a support arm 30 pivotally attached to the tip of the upper arm 20. These arms are made of metal, for example, cast iron or aluminum alloy casting.

In the robot 1, a cable 50 is arranged from the base 11 along the lower arm 12, as shown by the two-dot chain imaginary line in FIG. 1. Furthermore, as shown in FIGS. 2 and 3, the cable 50 is arranged on the upper arm 20 and is connected to an end effector (not shown) via the support arm 30.

The lower arm 12 is attached to the base 11 so as to be pivotable (rotatable) on a second rotation axis J2 that is parallel to a direction perpendicular to the first axis J1, via a second motor 40B. The upper arm 20 is attached to the lower arm 12 so as to be pivotable (rotatable) on a third rotation axis J3 that is parallel to the second rotation axis J2, via a third motor 40C.

The upper arm 20 includes a joint portion 21 that is pivotally attached to the tip of the lower arm 12, and an arm portion 22 that is attached to the joint portion 21 so as to be rotatable about a fourth rotation axis J4 that runs along the longitudinal direction of the upper arm 20.

Specifically, the lower arm 12 and the joint portion 21 are pivotally attached via the third motor 40C described above. The arm portion 22 rotates around the fourth rotation axis J4 relative to the joint portion 21 by the power of the fourth motor 40D. This "fourth rotation axis J4" corresponds to the "rotation axis along the longitudinal direction of the upper arm" as referred to in this invention.

Furthermore, the tip of the upper arm 20 corresponds to the wrist of the robot 1, and has a support arm 30 attached thereto that supports an end effector (not shown). In this embodiment, a fifth motor 40E is fixed to the arm portion 22 of the upper arm 20, causing the support arm 30 to pivot relative to the arm portion 22. As shown in FIG. 4, the fifth motor 40E is fixed at a position offset from the fourth rotation axis J4 about which the arm portion 22 rotates. Here, the fifth motor 40E corresponds to the "pivot motor" as defined in the present invention.

The fifth motor 40E is connected to the support arm 30 via a power transmission belt or the like built into the arm body 22B. As a result, the power of the fifth motor 40E is transmitted to the power transmission belt (not shown) built into the arm body 22B, causing the support arm 30 to pivot (swing) at the fifth rotation axis J5 relative to the arm portion 22.

More specifically, the support arm 30 is supported by a cantilever on the upper arm 20, and includes a joint 31 attached to the upper arm 20, and a support body 32 attached to the joint 31. The joint 31 is pivotally attached to the arm 22 at the tip of the arm 22 of the upper arm 20 on one side so as to be pivotable about a fifth rotation axis J5. The support body 32 is attached to the joint 31 so as to be rotatable around the axis of the support arm 30 relative to the joint 31. Furthermore, a sixth motor 40F that rotates the support body 32 is fixed to the joint 31 around the axis of the support arm 30 (specifically, the sixth rotation axis J6).

As a result, the joint 31 pivots on the fifth rotation axis J5 together with the support body 32 relative to the arm 22 with the power of the fifth motor 40E. In addition, the support body 32 rotates on the sixth rotation axis J6 relative to the joint 31 with the power of the sixth motor 40F.

2. Structure of the arm section 22 of the upper arm 20 As shown in Fig. 5, the arm section 22 of the upper arm 20 is formed at its base end with a ring-shaped insertion section 22A through which the cable 50 is inserted, and an arm body 22B extending from the insertion section 22A so as to be arranged in parallel with the cable 50. A through hole 22a through which the cable 50 is inserted is fixed to the insertion section 22A. Note that the "ring-shaped" referred to here does not only mean a circular loop, but also includes an elliptical loop, a polygonal loop, and the like.

The arm body 22B is formed so as to be continuous with a part of the periphery of the ring-shaped insertion portion 22A. In the portion excluding the first reinforcing rib 23 and the second reinforcing rib 24 described below, the arm body 22B extends from around the ring-shaped insertion portion 22A toward the tip of the upper arm 20 at a certain angle, centered on the fourth rotation axis J4. This angle is preferably in the range of about 45° to 90°, for example.

A first reinforcing rib 23 is formed on the arm portion 22 at a position opposite the cable 50 across the fifth motor 40E, and protrudes from the arm body 22B so as to surround the fifth motor 40E. By providing the first reinforcing rib 23 so as to surround the fifth motor 40E, the fifth motor 40E is protected and the rigidity of the arm portion 22 can be increased.

In this embodiment, as shown in Figures 4 and 6, the first reinforcing rib 23 extends from the insertion portion 22A toward the tip side of the arm body 22B. This makes it possible to suppress bending of the arm body 22B along the longitudinal direction. When an end effector (not shown) is attached to the support arm 30, a bending moment is likely to act on the base end of the arm body 22B, but by providing the first reinforcing rib 23, the bending rigidity of the arm portion 22 can be increased and the strength of the arm portion 22 can be ensured.

Furthermore, in this embodiment, as shown in FIG. 6, the first reinforcing rib 23 protrudes less from the arm body 22B as it approaches the tip of the arm body 22B. In other words, the first reinforcing rib 23 protrudes less from the arm body 22B as it approaches the tip of the arm body 22B.

This reduces the weight of the first reinforcing rib 23 at the tip side of the arm body 22B, while reducing the bending along the longitudinal direction of the arm section 22 at the base end side of the arm body 22B. Furthermore, in the section from the position where the fifth motor 40E is fixed to the tip side of the arm body 22B, the overhang of the first reinforcing rib 23 decreases as it moves toward the tip side, so the cable 50 can be seen from the first reinforcing rib 23 side.

4 and 6, the first reinforcing rib 23 protrudes from the longitudinal edge of the side surface 22b of the arm body 22B facing the cable 50 (fourth rotation axis J4). More specifically, the first reinforcing rib 23 protrudes along a direction going around the fourth rotation axis J4 (i.e., along the circumference of the ring-shaped insertion portion 22A) on the side of the insertion portion 22A from the fifth motor 40E. Furthermore, the first reinforcing rib 23 protrudes along a direction intersecting with the side surface 22b in a portion extending from the portion facing the fifth motor 40E to the tip side of the arm portion 22 (i.e., the arm body 22B).

Furthermore, in this embodiment, the arm portion 22 is formed with a second reinforcing rib 24 that protrudes from the arm body 22B so as to sandwich the cable 50 and face the first reinforcing rib 23. This allows the first reinforcing rib 23 and the second reinforcing rib 24 to increase the strength of the arm body 22B.

More specifically, the second reinforcing rib 24 is formed on the insertion portion 22A side of the position where the fifth motor 40E is fixed. More specifically, the second reinforcing rib 24 is formed from the insertion portion 22A to near the center of the arm body 22B in the longitudinal direction. The second reinforcing rib 24 is not formed in the section from near the center of the arm body 22B in the longitudinal direction to the tip of the arm portion 22. This makes it easier to wire the cable 50 when looking at the fourth rotation axis J2 from the second reinforcing rib 24 side, since the cable 50 can be seen together with the clamp portion 25 described below.

Here, the second reinforcing rib 24 protrudes from the arm body 22B in a direction that goes around the fourth rotation axis J4 (i.e., around the edge of the ring-shaped insertion portion 22A). As a result, the second reinforcing rib 24 and a part of the first reinforcing rib 23 protrude from the arm body 22B in a direction that goes around the fourth rotation axis J4 on the insertion portion 22A side of the fifth motor 40E, so that the shape of the arm portion 22 on the insertion portion 22A side of the fifth motor 40E is a shape that resembles a cylindrical portion with the peripheral wall cut away.

By making it in this shape, not only can the cable 50 be exposed from the arm portion 22 on the side of the insertion portion 22A from the position where the fifth motor 40E is fixed, but the through hole 22a of the insertion portion 22A through which the cable 50 is inserted can be visually confirmed.

Like the first reinforcing rib 23, the second reinforcing rib 24 protrudes less from the arm body 22B toward the tip of the arm body 22B. In this embodiment, the second reinforcing rib 24 is formed from the insertion portion 22A to near the center of the arm body 22B in the longitudinal direction. In addition, as shown in FIG. 5, the first reinforcing rib 23 protrudes more on the insertion portion 22A side of the arm portion 22 than the second reinforcing rib 24. In other words, the amount of protrusion of the first reinforcing rib 23 is greater than the amount of protrusion of the second reinforcing rib 24 on the insertion portion 22A side of the arm portion 22.

As described above, the arm body 22B extends parallel to the cable 50, and at the base end side of the arm body 22B, the insertion portion 22A through which the cable 50 is inserted is ring-shaped, so that the cable 50 can be exposed over a wider range from the upper arm 20.

Furthermore, as described above, the first reinforcing rib 23 protrudes more than the second reinforcing rib 24 on the insertion portion 22A side of the position where the fifth motor 40E is fixed. Therefore, in the section along the longitudinal direction of the arm portion 22, on the insertion portion 22A side of the position where the fifth motor 40E is fixed, an open space for performing the work of arranging the cable 50 can be secured on the second reinforcing rib 24 side.

Furthermore, in the section where the fifth motor 40E is fixed, the arm section 22 is formed with a first reinforcing rib 23 that protrudes from the arm body so as to surround the fifth motor 40E at a position opposite the cable 50 across the fifth motor 40E. Therefore, on the opposite side of the fifth motor 40E from the position where the first reinforcing rib 23 is formed, an open space is formed so that the cable 50 is exposed. This makes it possible to secure space for performing the work of arranging the cable 50.

3. Mounting Structure of Cable 50 The mounting structure of the cable 50 will be described below. The cable 50 is attached to the robot 1 as shown by the imaginary lines in Figs. 1 to 7. There are a plurality of cables 50, and the imaginary lines shown indicate the range through which the plurality of cables pass. As shown in Fig. 1, the cable 50 is disposed along the base 11 and the lower arm 12. As shown in Figs. 2 and 3, the cable 50 is disposed on the upper arm 20, and is connected to an end effector (not shown) via the support arm 30. As described above, the end effector is attached to the support arm 30 and supported by the support arm 30. Note that a part of the cable 50 may be connected to the fifth motor 40E and the sixth motor 40F.

The cable 50 is arranged in the upper arm 20 along the longitudinal direction of the arm portion 22. Note that in the drawings, the cable 50 is shown as being arranged on the fourth rotation axis J4 for convenience, but it is arranged in the arm portion 22 with some slack so that the cable 50 is not subjected to a large tension due to the pivoting and rotation of the support arm 30. Therefore, in the present invention, "the cable is arranged along the longitudinal direction of the upper arm" also includes such a state.

In this embodiment, a through hole 22a is formed in the insertion portion 22A of the arm portion 22, and a through hole 30a is also formed in the support arm 30. Therefore, the cable 50 is inserted through the through hole 22a of the arm portion 22, arranged along the longitudinal direction of the arm portion 22, inserted through the through hole 30a of the support arm 30, and connected to an end effector (not shown).

In this embodiment, the fifth motor 40E is fixed to the arm main body 22B at a position offset from the fourth rotation axis J4. Specifically, the fifth motor 40E is disposed closer to the first reinforcing rib 23 than the fourth rotation axis J4. Furthermore, the sixth motor 40F is fixed to the joint portion 31 of the support arm 30 at a position offset from the fourth rotation axis J4. Specifically, the sixth motor 40F is disposed at a position such that the fourth rotation axis J4 is sandwiched between the sixth motor 40F and the arm portion 22.

By arranging the fifth motor 40E and the sixth motor 40F in such a position, a space through which the cable 50 passes can be formed on the fourth rotation axis J4. Furthermore, since the fifth motor 40E and the sixth motor 40F are exposed from the arm portion 22, heat generated when these motors are driven can be easily dissipated to the outside.

Arranged on the arm portion 22 are wirings (not shown), such as a supply line that supplies power to the fifth motor 40E, a signal line (not shown) for a control signal that controls the rotation of the fifth motor 40E, and a detection line (not shown) for a detection signal such as the rotation position detected by the fifth motor 40E. In this embodiment, these wirings are arranged on a route different from that of the cable 50, and the arm portion 22 is provided with a connection portion 41E where these wirings are connected to the fifth motor 40E. The connection portion 41E is arranged in a position along the longitudinal direction between the clamp portion 25 and the guide portion 26, which will be described later.

In this embodiment, as shown in Figs. 6 and 7, the connection part 41E is composed of these wires (not shown) and a wiring box that houses these wires, but for example, these wires may be tied together with a cable tie or the like. Similarly, a connection part 41F is provided to which wires (not shown) such as supply lines, signal lines, and detection lines are connected to the sixth motor 40F. As shown in Fig. 4, in a side view of the arm part 22, the connection part 41F is provided on the opposite side of the sixth motor 40F from the cable 50.

In this embodiment, as shown in FIG. 5, the clamp portion 25 and the guide portion 26 are fixed to the side surface 22b of the arm body 22B via the base plate 27. At the position where the clamp portion 25 and the guide portion 26 are arranged, there is almost no protrusion due to the second reinforcing rib 24 described above, so an open space is formed near the attachment position of the clamp portion 25 and the guide portion 26. Therefore, when wiring the cable 50, the cable 50 can be easily arranged in an appropriate position together with the clamp portion 25 and the guide portion 26.

When attaching the clamp portion 25 and the guide portion 26 to the arm body 22B, they can first be attached to the base plate 27, and then the base plate 27 can be fixed to the arm body 22B. This allows the relative positions of the clamp portion 25 and the guide portion 26 to be adjusted before attachment to the arm body 22B. This allows the clamp portion 25 and the guide portion 26 to be accurately fixed to the arm body 22B, ensuring the optimal route for the cable 50.

In this embodiment, a base plate 27 is provided, but the clamp portion 25 and the guide portion 26 may be directly fixed to the arm body 22B with a fastener such as a bolt, as long as the clamp portion 25 and the guide portion 26 can be positioned at an appropriate position on the arm body 22B together with the cable 50.

The clamp unit 25 is a part that holds the cable 50 to the arm body 22B at a position facing the fifth motor 40E. As shown in FIG. 7, the clamp unit 25 includes a support bracket 25a that is attached to the base plate 27 via a fastener such as a bolt or a screw, and a U-shaped fastener 25b that is attached to the support bracket 25a.

The support bracket 25a is erected on the base plate 27 so as to extend on the opposite side of the arm body 22B from the base plate 27, and supports the cable 50 together with the fastener 25b. With the fastener 25b attached to the support bracket 25a, the clamp section 25 is formed with a holding hole 25A through which the cable 50 is inserted and held.

In this embodiment, the cable 50 passes through the fourth rotation axis J4, and therefore the retaining hole 25A that holds the cable 50 is formed at a position where the fourth rotation axis J4 passes. Therefore, the cable 50 inserted through the retaining hole 25A of the clamp portion 25 is held in a suspended state along the fourth rotation axis J4.

The holding hole 25A may be of any size so long as the clamp portion 25 can hold the cable 50, and may hold the cable 50 so that the cable 50 can move in a direction along the fourth rotation axis J4 by pivoting and rotating the support arm 30. Furthermore, as shown in FIG. 2, the support arm 30 may further be provided with a clamp portion 28 that holds the cable 50.

The guide portion 26 is a portion that guides the cable 50 movably around the fourth rotation axis J4 on the tip side of the arm portion 22, closer to the clamp portion 25 and the fifth motor 40E. In this embodiment, the guide portion 26 is a frame that is erected on the arm portion 22 via the base plate 27, and has a guide hole 26A that guides the cable 50.

Specifically, the guide section 26 includes a pair of first brackets 26a, 26a attached to the base plate 27 via fasteners such as bolts or screws, and a second bracket 26c attached to the pair of first brackets 26a, 26a so as to bridge the pair of first brackets 26a, 26a. The first bracket 26a and the second bracket 26c are members formed from a metal plate.

The pair of first brackets 26a, 26a are spaced apart from each other and stand upright on the base plate 27, sandwiching the fourth rotation axis J4. With the second bracket 26c attached to the pair of first brackets 26a, 26a, a guide hole 26A is formed in the guide section 26. The guide hole 26A has a rectangular shape in a cross section perpendicular to the fourth rotation axis J4, and the opening area of the guide hole 26A is larger than the opening area of the retaining hole 25A. This forms a space in the guide section 26 that allows the cable 50 to move freely around the fourth rotation axis J4.

In this embodiment, the periphery of the guide portion 26, which is the frame, is bent toward the outside of the guide hole 26A formed in the guide portion 26 through which the cable 50 passes. Specifically, the periphery portions 26b, 26d on both sides of the guide hole 26A formed by the pair of first brackets 26a, 26a and the second bracket 26c are bent toward the outside of the guide hole 26A. Therefore, in this embodiment, the openings on both sides of the guide hole 26A are widened toward the outside. By providing such a guide hole 26A, even if the cable 50 swings around inside the guide portion 26, the cable 50 comes into contact with the edges of the periphery portions 26b, 26d that form the guide hole of the guide portion 26, and the cable 50 is prevented from being damaged.

In this embodiment, the arm body 22B is provided with a clamp portion 25 that holds the cable 50 at a position facing the fifth motor 40E, so that the cable 50 can be prevented from coming into contact with the fifth motor 40E due to the cable 50 swinging. Furthermore, by providing a guide portion 26 that movably guides the cable 50 at the tip side of the arm portion 22, the range in which the cable 50 swings can be limited, and the cable 50 can be prevented from coming into contact with the fifth motor 40E.

In this embodiment, as described above, the clamp portion 25 and the guide portion 26 are disposed in the center of the arm body 22B along the fourth rotation axis J4. As a result, while the cable 50 is likely to swing around in the center of the arm body 22B along the fourth rotation axis J4, by providing the clamp portion 25 and the guide portion 26 in the center of the arm body 22B, it is possible to suppress the swinging of the cable 50.

Furthermore, by limiting the swinging of the cable 50 in this manner, the connection part 41E, to which the wiring of the fifth motor 40E is connected, can be disposed between the clamp part 25 and the guide part 26. This makes it possible to reduce the size of the arm part 22 while suppressing contact of the cable 50 with the connection part 41E.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-mentioned embodiments, and various design changes can be made without departing from the spirit of the present invention as described in the claims.

1: robot (industrial robot), 11: base, 12: lower arm, 20: upper arm, 21: joint portion, 22: arm portion, 22A: insertion portion, 22B: arm body, 23: first reinforcing rib, 24: second reinforcing rib, 25: clamp portion, 26: guide portion, 40E: fifth motor (pivot motor), 30: support arm, 50: cable, J4: fourth rotating shaft (rotating shaft)

Claims (3)

a lower arm having a base end pivotally connected to a base;
an upper arm pivotally connected to a tip end of the lower arm;
A support arm pivotally attached to a tip of the upper arm;
and a cable disposed on at least the upper arm.
the upper arm includes a joint portion pivotally attached to a tip end of the lower arm, and an arm portion attached to the joint portion so as to be rotatable about a rotation axis along a longitudinal direction of the upper arm,
The cable is arranged along the longitudinal direction,
a pivot motor for pivoting the support arm relative to the upper arm is fixed to the arm portion at a position offset from the rotation shaft,
the arm portion is formed at a base end thereof with a ring-shaped insertion portion through which the cable is inserted, and an arm body extending from the insertion portion so as to be juxtaposed to the cable,
a power transmission belt that transmits the power of the pivot motor to the support arm is built into the arm body;
a first reinforcing rib is formed on the arm portion so as to surround the pivot motor at a position opposite to the cable with the pivot motor sandwiched therebetween, the first reinforcing rib extending from the arm body;
The first reinforcing rib extends from the insertion portion to a tip of the arm body,
the first reinforcing rib protrudes less from the arm body toward the tip of the arm body,
a second reinforcing rib is formed protruding from the arm body on the insertion portion side of a position where the pivot motor is fixed, so as to face the first reinforcing rib with the cable in between,
a clamp portion that holds the cable on the arm body at a position facing the pivot motor so as to wrap around the cable;
a guide portion that movably guides the cable is provided at a position closer to a tip end of the arm portion than the clamp portion and the pivot motor,
2. An industrial robot according to claim 1, wherein the clamp portion, the guide portion and the pivot motor are disposed at a center of the arm body along the longitudinal direction. The industrial robot according to claim 1, characterized in that the first reinforcing rib protrudes more than the second reinforcing rib. 2. The industrial robot according to claim 1 , wherein the clamp portion and the guide portion are fixed to the arm body via a base plate.

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