WO2022180795A1

WO2022180795A1 - Robot

Info

Publication number: WO2022180795A1
Application number: PCT/JP2021/007382
Authority: WO
Inventors: 宗石川
Original assignee: 株式会社Fuji
Priority date: 2021-02-26
Filing date: 2021-02-26
Publication date: 2022-09-01
Also published as: JPWO2022180795A1

Abstract

This robot comprises: a robot arm; a drive motor affixed to the robot arm; a bearing member outer ring affixed to the robot arm; a bearing member inner ring that rotates along the outer ring; a force sensor support part that is affixed to the inner ring and rotates due to the drive motor; a force sensor action part supported by the supporting part; and a load part that is linked to the action part and passes through the inner ring.

Description

robot

This specification discloses a robot.

Conventionally, a robot arm with a force sensor attached has been proposed (see Patent Document 1, for example).

Special table 2019-504680

When a force sensor is attached to the robot arm so as to be interposed between the load section (end effector) and the drive motor, depending on the arrangement of the bearing member and the load section, the interference between the inner ring of the bearing member and the load section may There is a risk that the force sensor will detect an undesired force.

The main purpose of the present disclosure is to prevent the force sensor from detecting unintended force due to interference between the inner ring of the bearing member and the load portion.

This disclosure has taken the following means to achieve the above-mentioned main objectives.

The robot of the present disclosure is
a robot arm;
a drive motor fixed to the robot arm;
an outer ring of a bearing member fixed to the robot arm;
an inner ring of the bearing member that rotates along the outer ring;
a support for a force sensor fixed to the inner ring and rotated by the drive motor;
an action portion of the force sensor supported by the support portion;
a load portion coupled to the action portion and inserted through the inner ring;
The gist is to provide

In the robot of the present disclosure, the supporting portion of the force sensor rotated by the drive motor is fixed to the inner ring of the bearing member, and the load portion is connected to the action portion of the force sensor by inserting it through the inner ring of the bearing member. Accordingly, it is possible to prevent the force sensor from detecting an unintended force due to interference between the inner ring of the bearing member and the load portion.

It is an external appearance perspective view of the robot of this embodiment. It is a side view of a robot main body. FIG. 2 is a schematic configuration diagram of the tip of the robot; It is a sectional view of a robot tip part. 1 is a schematic configuration diagram of a force sensor; FIG. FIG. 5 is a schematic configuration diagram of a robot tip portion according to another embodiment;

Next, a mode for carrying out the present disclosure will be described with reference to the drawings. FIG. 1 is an external perspective view of the robot. FIG. 2 is a side view of the robot body. FIG. 3 is a schematic configuration diagram of the tip of the robot. FIG. 4 is a cross-sectional view of the tip of the robot. In FIG. 1, the horizontal direction is the X-axis, the front-rear direction is the Y-axis, and the vertical direction is the Z-axis.

The robot 10 of this embodiment includes a robot body 20 and a force sensor 70, as shown in FIGS.

As shown in FIG. 2, the robot body 20 includes a first arm 21, a second arm 22, a base 25, a base 26, a first arm drive motor 35, a second arm drive motor 36, a posture It includes a holding device 37 , a lifting device 40 and a rotating three-axis mechanism 50 . Note that the first arm 21, the second arm 22, and the rotating three-axis mechanism 50 may be simply referred to as arms.

The base end of the first arm 21 is connected to the base 25 via a first joint shaft 31 extending in the vertical direction (Z-axis direction). A rotation shaft of the first arm drive motor 35 is connected to the first joint shaft 31 . The first arm drive motor 35 rotationally drives the first joint shaft 31 to rotate (rotate) the first arm 21 along the horizontal plane (XY plane) with the first joint shaft 31 as a fulcrum.

The proximal end of the second arm 22 is connected to the distal end of the first arm 21 via a second joint shaft 32 extending in the vertical direction (Z-axis direction). A rotation shaft of the second arm drive motor 36 is connected to the second joint shaft 32 . The second arm drive motor 36 rotates (revolves) the second arm 22 along the horizontal plane with the second joint shaft 32 as a fulcrum by rotationally driving the second joint shaft 32 .

The base 25 is provided so as to be able to move up and down with respect to the base 26 by an elevating device 40 installed on the base 26 . As shown in FIGS. 1 and 2, the lifting device 40 includes a slider 41 fixed to the base 25 and a guide member 42 fixed to the base 26 and extending vertically to guide the movement of the slider 41 . , a ball screw shaft 43 (elevating shaft) extending vertically and screwed into a ball screw nut (not shown) fixed to the slider 41; And prepare. The elevator device 40 moves the base 25 fixed to the slider 41 up and down along the guide member 42 by rotationally driving the ball screw shaft 43 by the elevator drive motor 44 .

The rotating 3-axis mechanism 50 is connected to the distal end of the second arm 22 via a posture holding shaft 33 extending in the vertical direction. The rotating three-axis mechanism 50 includes a first rotating shaft 51, a second rotating shaft 52, and a third rotating shaft (tip shaft 53) that are orthogonal to each other, a first rotating shaft drive motor 55 that rotates the first rotating shaft 51, A second rotary shaft drive motor 56 that rotates the second rotary shaft 52 and a tip shaft drive device 60 that drives the tip shaft 53 are provided. The first rotating shaft 51 is supported in a posture perpendicular to the posture holding shaft 33 . The second rotating shaft 52 is supported in an orthogonal posture with respect to the first rotating shaft 51 . The third rotating shaft (tip shaft 53 ) is supported in a posture orthogonal to the second rotating shaft 52 . The tip shaft 53 holds an end effector EF as a load portion so as to be coaxial with the tip shaft 53a.

In this embodiment, the robot main body 20 performs translational motion in three directions of the X-axis direction, the Y-axis direction, and the Z-axis direction by the first arm drive motor 35, the second arm drive motor 36, and the lifting device 40, and rotates in three directions. In combination with rotational motion in three directions around the X-axis (pitching), around the Y-axis (rolling), and around the Z-axis (yawing) by the shaft mechanism 50, the tip shaft 53, that is, the end effector EF can be moved in any posture and in any desired position. position can be moved.

The posture holding device 37 holds the posture of the rotating three-axis mechanism 50 (orientation of the first rotating shaft 51) in a constant direction regardless of the postures of the first arm 21 and the second arm 22. The posture holding device 37 maintains the posture based on the rotation angle of the first joint shaft 31 and the rotation angle of the second joint shaft 32 so that the axial direction of the first rotating shaft 51 is always in the left-right direction (X-axis direction). It controls the rotation angle of the holding shaft 33 . As a result, control of translational motion in three directions and control of rotational motion in three directions can be performed independently of each other, facilitating control.

The distal end shaft driving device 60 includes a frame 61, a driving motor 62, a power transmission mechanism 63, a connecting shaft 65, a bearing member 67, a gripping member 69, and a force sensor 70, as shown in FIGS.

The frame 61 is a rectangular frame fixed to the second rotating shaft 52 and rotates integrally with the second rotating shaft 52 when the second rotating shaft 52 is driven. The drive motor 62 is fixed to the frame 61 so that its rotating shaft 62 a is parallel to the axial direction of the second rotating shaft 52 . The connecting shaft 65 is supported by the frame 61 so as to extend vertically. That is, the connecting shaft 65 extends in a direction orthogonal to the rotation shaft 62 a of the drive motor 62 and the second rotation shaft 52 .

The power transmission mechanism 63 has a bevel gear 63a attached to the rotating shaft 62a of the drive motor 62, and a bevel gear 63b attached to the connecting shaft 65 and meshing with the bevel gear 63a. The power transmission mechanism 63 connects the rotating shaft 62a of the drive motor 62 and the connecting shaft 65, which are perpendicular to each other, to transmit power from the driving motor 62 to the connecting shaft 65. As shown in FIG.

The force sensor 70 detects force components acting in the directions of the X-, Y-, and Z-axes as external forces, and torque components acting around the respective axes. As shown in FIG. 5 , the force sensor 70 includes an action portion 71 to which force acts, an annular support portion 72 that supports the action portion 71 on the inner peripheral side, and a force between the action portion 71 and the support portion 72 . and a detection portion 73 that is arranged at a predetermined interval in the circumferential direction and detects a force acting on the action portion 71 . As shown in FIG. 4 , the upper surface of the support portion 72 is superimposed on and connected to the lower surface of the flange portion 65 a formed at the lower end of the connecting shaft 65 . In addition, the lower surface of the support portion 72 is superimposed and connected to the upper surface of the flange portion 66a formed at the upper end of the cylindrical fixing member 66. As shown in FIG. A tubular outer peripheral surface of the fixing member 66 is fixed to an inner peripheral surface of an inner ring 67 a of the bearing member 67 . That is, the support portion 72 is fixed to the inner ring 67 a of the bearing member 67 via the fixing member 66 . An outer ring 67 b of the bearing member 67 is fixed to the frame 61 . Thereby, the connecting shaft 65 and the support portion 72 of the force sensor 70 are rotatably supported by the frame 61 via the bearing member 67 .

The lower surface of the action portion 71 is connected to the upper end of the tip shaft 53, and the lower end of the tip shaft 53 is attached with an end effector EF as a load portion via a holding portion (not shown). Further, the upper surface of the action portion 71 is connected to the proximal end portion of the gripping member 69 as the second load portion. The gripping member 69 is provided so as to extend radially outward from the connecting shaft 65 . As described above, in the present embodiment, the end effector EF is connected to the lower surface of the acting portion 71 of the force sensor 70 via the tip shaft 53, and the gripping member 69 is directly connected to the upper surface of the acting portion 71. It is configured such that force acts on the action portion 71 from both the upper surface and the lower surface. Thereby, the force received from the end effector EF and the force received from the grasping member 69 can be detected by the single force sensor 70 .

The tip shaft 53 is inserted through the inner ring 67a of the bearing member 67, as shown in FIG. In this embodiment, the cylindrical outer peripheral surface of the fixed member 66 connected to the support portion 72 of the force sensor 70 is fixed to the inner peripheral surface of the inner ring 67a, and the distal end shaft 53 extends from the inner peripheral surface of the fixed member 66. is inserted into the As shown in FIG. 4, a predetermined radial gap is provided between the cylindrical inner peripheral surface of the fixing member 66 and the outer peripheral surface of the tip shaft 53 . As a result, the distal end shaft 53 connected to the acting portion 71 of the force sensor 70 and the fixed member 66 (inner ring 67a) fixed to the support portion 72 of the force sensor 70 are prevented from interfering with each other, and the force sense is generated by the interference. It is possible to prevent the sensor 70 from detecting an unintended force.

Further, by interposing the power transmission mechanism 63 between the rotating shaft 62a of the drive motor 62 and the distal end shaft 53, the rotating shaft 62a of the driving motor 62 is arranged on a different shaft from the distal end shaft 53, and the end effector EF can be operated. can be attached coaxially with the tip shaft 53 . As a result, the shaft length can be further shortened compared to a configuration in which the rotation shaft 62a of the drive motor 62, the distal end shaft 53, and the end effector EF are arranged coaxially.

Furthermore, a grasping member 69 is connected to the upper surface of the acting portion 71 of the force sensor 70 . Therefore, when the operator manually moves the robot body 20 and performs direct teaching to record the motion of the robot body 20, the operator can directly move the arm by gripping the grip member 69, which facilitates the operation. . Further, at this time, the force sensor 70 can detect the external force applied from the gripping member 69, so that the motion of the robot body 20 can be recorded more accurately. Of course, direct teaching can also be performed by gripping the end effector EF and moving the robot body 20 . In this case, the gripping member 69 may be omitted.

Here, the correspondence between the main elements of the embodiment and the main elements of the present disclosure described in the claims will be described. That is, the first arm 21, the second arm 22, and the rotating three-axis mechanism 50 of the present embodiment correspond to the robot arm of the present disclosure, the inner ring 67a of the bearing member 67 corresponds to the inner ring of the bearing member, and the bearing member 67 corresponds to the outer ring of the bearing member, the supporting portion 72 of the force sensor 70 corresponds to the supporting portion of the force sensor, the acting portion 71 of the force sensor 70 corresponds to the acting portion of the force sensor, The tip shaft 53 and the end effector EF correspond to the load section. Also, the gripping member 69 corresponds to the second load section. Further, the connecting shaft 65 corresponds to a connecting member, the frame 61 corresponds to a frame, and the power transmission mechanism 63 corresponds to a power transmission member. Also, the

bevel gears

63a and 63b correspond to bevel gears.

It goes without saying that the present disclosure is by no means limited to the above-described embodiments, and can be implemented in various forms as long as they fall within the technical scope of the present disclosure.

For example, in the above-described embodiment, the distal end shaft driving device 60 includes a driving motor 62 having a rotation shaft 62a arranged so as to be orthogonal to a connecting shaft 65 coaxial with the distal end shaft 53, and

bevel gears

63a, 63a. A power transmission mechanism 63 that connects the rotating shaft 62 a and the connecting shaft 65 to transmit the power from the drive motor 62 to the connecting shaft 65 is provided. On the other hand, as shown in FIG. 6, a distal end shaft driving device 160 according to another embodiment includes a driving motor 162 arranged such that a rotating shaft 162a is parallel to a connecting shaft 165, and a belt 163a. A power transmission mechanism 163 that connects the parallel rotating shaft 162 and the connecting shaft 165 to transmit power from the driving motor 162 to the connecting shaft 165 may be provided.

Further, in the above-described embodiment, the distal end shaft driving device 60 has the load portions connected to both upper and lower surfaces of the action portion 71 of the force sensor 70, but the load portion is connected to only one of the surfaces. may be

Also, in the above-described embodiment, the robot 10 is configured as a seven-axis articulated robot capable of translational motion in three directions and rotational motion in three directions. However, the number of axes can be any number. Also, the robot 10 may be configured by a so-called vertical articulated robot, a horizontal articulated robot, or the like.

As described above, in the robot according to the present disclosure, the support portion of the force sensor rotated by the drive motor is fixed to the inner ring of the bearing member, and the load portion is inserted through the inner ring of the bearing member to act on the force sensor acting portion. concatenate Accordingly, it is possible to prevent the force sensor from detecting an unintended force due to interference between the inner ring of the bearing member and the load portion.

Further, the robot of the present disclosure may further include a second load section connected to a surface of the action section opposite to the surface to which the load section is connected. With this configuration, the force sensor can detect the force applied from the load section and the second load section.

Further, in the robot according to the present disclosure, a connecting member that connects the rotation shaft of the drive motor and the support portion is provided, and the force sensor has an annular shape that supports the action portion on which a force acts on an inner peripheral side. The outer ring is fixed to the frame of the robot arm, and the connecting member is connected to the rotation shaft of the drive motor via a power transmission member, and is driven by power from the drive motor. It may be connected to the support so as to rotate coaxially with the load. By providing a connection member and connecting the rotation shaft of the drive motor to the connection member via the power transmission member, the rotation shaft of the connection member (the drive shaft of the robot) is arranged coaxially with the load section, and the drive motor and the force are connected. It is possible to ensure the degree of freedom in arranging the sensor. As a result, it is possible to shorten the shaft length and make the device (tip driving device) more compact.

The power transmission member is a bevel gear, and the rotation shaft of the drive motor is perpendicular to the axial direction of the connection member. and connected to the connecting member via the bevel gear. Alternatively, the power transmission member may be a belt, and the rotating shaft of the drive motor may be arranged parallel to the axial direction of the connecting member and connected to the connecting member via the belt.

The present disclosure can be used in the robot manufacturing industry and the like.

10 Robot, 20 Robot body, 21 First arm, 22 Second arm, 25 Base, 26 Base, 31 First joint axis, 32 Second joint axis, 33 Posture holding axis, 35 First arm drive motor, 36 2nd arm drive motor, 37 posture holding device, 40 lifting device, 41 slider, 42 guide member, 43 ball screw shaft, 44 lifting drive motor, 50 rotating 3-axis mechanism, 51 first rotating shaft, 52 second rotating shaft , 53 third rotary shaft (tip shaft), 55 first rotary shaft drive motor, 56 second rotary shaft drive motor, 60, 160 tip shaft drive device, 61, 161 frame, 62, 162 drive motor, 62a, 162a rotation Shaft, 63, 163 power transmission mechanism, 63a, 63b bevel gear, 65, 165 connecting shaft, 66 fixing member, 66a flange portion, 67 bearing member, 67a inner ring, 67b outer ring, 69 gripping member, 163a belt, 70 force sensor , 71 working part, 72 supporting part, 73 detecting part, EF end effector.

Claims

a robot arm;
a drive motor fixed to the robot arm;
an outer ring of a bearing member fixed to the robot arm;
an inner ring of the bearing member that rotates along the outer ring;
a support for a force sensor fixed to the inner ring and rotated by the drive motor;
an action portion of the force sensor supported by the support portion;
a load portion coupled to the action portion and inserted through the inner ring;
A robot with
The robot according to claim 1,
A second load portion connected to a surface of the action portion opposite to the surface to which the load portion is connected,
robot.
The robot according to claim 1 or 2,
A connecting member that connects the rotation shaft of the drive motor and the support portion,
The force sensor has an annular support portion that supports the action portion on which the force acts on the inner peripheral side,
The outer ring is fixed to the frame of the robot arm,
The connecting member is connected to the rotating shaft of the drive motor via a power transmission member, and is connected to the support portion so as to rotate coaxially with the load portion by power from the drive motor.
robot.
The robot according to claim 3,
The power transmission member is a bevel gear,
A rotating shaft of the drive motor is arranged perpendicular to the axial direction of the connecting member, and is connected to the connecting member via the bevel gear.
robot.
The robot according to claim 3,
The power transmission member is a belt,
A rotating shaft of the drive motor is arranged parallel to the axial direction of the connecting member and connected to the connecting member via the belt.
robot.