Scara robot and robot system

Abstract

To provide a highly reliable SCARA robot and a robot system.SOLUTION: The robot includes a base, a first arm coupled to the base and rotating about a first shaft, a second arm 30 coupled to the first arm and rotating about a second shaft parallel to the first shaft, a first shaft 41 provided in the second arm 30 and movable along a third shaft J3 parallel to the second shaft and rotating about the third shaft J3, a second shaft 42 provided in the second arm 30 and extending along a ball screw shaft BS parallel to the third shaft J3, an upper coupling member 61 provided in the second shaft 42, rotatably supporting an upper end 41a of the first shaft 41, and movable along the ball screw shaft BS, and an inertial sensor 80 disposed in the upper coupling member 61 and detecting at least one of acceleration and angular speed.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a SCARA robot and a robot system. [Background technology]

[0002] Patent Document 1 discloses the configuration of a horizontal articulated robot having a first arm and a second arm. The second arm is equipped with an end effector having a slide shaft that holds a workpiece at its tip and moves up and down along the vertical direction. A gyro sensor module that detects horizontal vibrations of the second arm is installed at the bottom of the second arm. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-111665 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the configuration described in Patent Document 1 has a problem in that although it is possible to detect horizontal vibrations of the second arm, it is difficult to detect vertical vibrations of the slide shaft. [Means for solving the problem]

[0005] The SCARA robot comprises a base, a first arm connected to the base and rotating around a first axis, a second arm connected to the first arm and rotating around a second axis parallel to the first axis, a first shaft attached to the second arm and movable along a third axis parallel to the second axis and rotating around the third axis, a second shaft attached to the second arm and extending along a fourth axis parallel to the third axis, a connecting member attached to the second shaft and rotatably supporting an end of the first shaft and movable along the fourth axis, and an inertial sensor disposed on the connecting member for detecting at least one of acceleration and angular velocity.

[0006] The robot system includes the above-described SCARA robot and a control device that controls the SCARA robot and receives a signal from the inertial sensor to control the operating frequency of the SCARA robot. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a perspective view showing a configuration of a robot system. [Figure 2] FIG. 2 is a side view showing the configuration of a SCARA robot. [Figure 3] FIG. 2 is a perspective view showing the internal configuration of a SCARA robot. [Figure 4] FIG. 2 is a cross-sectional view showing the internal configuration of the SCARA robot. [Figure 5] FIG. 2 is a perspective view showing the internal configuration of a SCARA robot. [Figure 6] FIG. 2 is a perspective view showing the internal configuration of a SCARA robot. DETAILED DESCRIPTION OF THE INVENTION

[0008] The configurations of the SCARA robot 100 and the robot system 1000 will be described below with reference to the drawings. In the following drawings, three mutually orthogonal axes will be referred to as the X-axis, Y-axis, and Z-axis. The direction along the X-axis is referred to as the "X direction," the direction along the Y-axis as the "Y direction," and the direction along the Z-axis as the "Z direction." The direction of the arrow is the + direction, and the direction opposite to the + direction is referred to as the - direction. Note that a view from the +Z direction or the -Z direction is also referred to as a planar view or planar.

[0009] First, the configuration of a robot system 1000 will be described with reference to FIG.

[0010] As shown in FIG. 1, the robot system 1000 includes a SCARA robot 100 and a control device 200 that controls the driving of the SCARA robot 100.

[0011] The SCARA robot 100 is a horizontal articulated robot, and is used for various tasks such as holding, transporting, processing, assembling, and inspecting workpieces such as electronic components and mechanical components. The uses of the SCARA robot 100 are not particularly limited. The SCARA robot 100 may also be a so-called ceiling-suspended SCARA robot, which is installed by being suspended from the ceiling.

[0012] The SCARA robot 100 includes a base 10, a first arm 20 rotatably connected to the base 10, and a second arm 30 rotatably connected to the first arm 20.

[0013] Head covers 31A and 31B that cover, for example, a shaft that holds a workpiece are disposed on the tip side of the second arm 30. The head covers 31A and 31B are made of, for example, resin or metal. A pipe 11 that connects the second arm 30 and the base 10 is provided on the first arm 20 side of the second arm 30.

[0014] The piping 11 accommodates power supply lines, signal lines, and the like that extend from the inside of the base 10 to the inside of the second arm 30. That is, these power supply lines, signal lines, and the like are configured as insulated cords or as a cable made up of bundled cords. The piping 11 is flexible, and therefore can adequately follow changes in the posture of the robot arm caused by the rotation of the first arm 20 and the second arm 30.

[0015] The base 10 is fixed to a floor surface parallel to a horizontal plane. The base 10 is connected to the control device 200 via wiring 210. The wiring 210 electrically connects the control device 200 to the drive unit of the base 10, the drive unit of the second arm 30, and the like. If the SCARA robot 100 is a ceiling-suspended type, the base 10 is fixed to, for example, a top plate located on the top of the base, the ceiling of a work room, a beam, column, brace, or other structure installed on or near the ceiling, a hoist rail, a wall of the base or work room, or the like.

[0016] The control device 200 is not limited to being arranged outside the SCARA robot 100, in other words, as a separate unit, but may be arranged inside the base 10 of the SCARA robot 100, for example.

[0017] The control device 200 controls the energization conditions for each motor via a motor driver (not shown) based on, for example, rotational position information of each motor received from an encoder (not shown). This causes the first arm 20, the second arm 30, the first shaft 41, the second shaft 42, etc. to operate, and the desired work can be performed according to a predetermined program. In addition, the control device 200 performs correction to suppress vibrations in the direction along the third axis J3 (see FIG. 3) based on data detected by the inertial sensor 80 (see FIGS. 3 and 4).

[0018] Next, a specific configuration of the SCARA robot 100 will be described with reference to FIGS.

[0019] As shown in FIG. 2, the SCARA robot 100 includes the base 10, the first arm 20, and the second arm 30, as described above.

[0020] The first arm 20 has a base end connected to the base 10 and rotates about a first axis J1 along the vertical direction. The second arm 30 has a base end connected to the first arm 20 and rotates about a second axis J2 that is parallel to the first axis J1 along the vertical direction.

[0021] The base 10 is provided with a drive motor 12 that drives the first arm 20. The base 10 is connected to the first arm 20 via a reducer 13 that is connected to the output shaft of the drive motor 12. The output side of the reducer 13 is fixed to the base end of the first arm 20. In other words, the first arm 20 rotates relative to the base 10 as the rotation of the drive motor 12 is reduced in speed and transmitted by the reducer 13.

[0022] A reducer 21 for driving the second arm 30 is provided at the rotating end of the first arm 20. The output side of the reducer 21 is fixed to the first arm 20, and the input side is connected to a drive motor 22 of the second arm 30. In other words, the rotation of the drive motor 22 is reduced by the reducer 21 and transmitted to the first arm 20, causing the second arm 30 to rotate around the drive motor 22 relative to the first arm 20.

[0023] 3, the SCARA robot 100 has a first shaft 41 and a second shaft 42 arranged on the second arm 30. The SCARA robot 100 also has an upper connecting member 61 as a connecting member, and an inertial sensor 80 is arranged on the upper surface of the upper connecting member 61.

[0024] In this way, since the inertial sensor 80 is disposed on the upper surface of the upper connecting member 61, it is possible to prevent the upper connecting member 61 from falling even when it repeatedly moves along the ball screw shaft BS. Note that the inertial sensor 80 only needs to be fixed to the upper connecting member 61, but when detecting gravity using the inertial sensor 80, it is preferable that the gravity detection axis of the inertial sensor 80 is disposed along a vertical line.

[0025] As described above, the first shaft 41 is provided on the second arm 30 and is movable along the third axis J3 parallel to the second axis J2, and rotates about the third axis J3. The second shaft 42 is provided on the second arm 30 and extends along the ball screw axis BS, which is the fourth axis parallel to the third axis J3.

[0026] The upper connecting member 61 is provided on the second shaft 42, rotatably supports the upper end 41a (see FIG. 4) of the first shaft 41, and is movable along the ball screw axis BS. The inertial sensor 80 detects at least one of acceleration and angular velocity. The inertial sensor 80 is, for example, a one-axis acceleration sensor that detects acceleration in a direction along the third axis J3, i.e., the Z axis.

[0027] The inertial sensor 80 may be an acceleration sensor that further detects at least one of the X-axis and Y-axis, a gyro sensor that detects angular velocity, or an IMU (Inertial Measurement Unit) that detects both acceleration and angular velocity.

[0028] In addition, a first drive motor 71 and a second drive motor 72 are arranged on the second arm 30.

[0029] The first drive motor 71 is connected to a first drive belt 71A, and is connected to the first shaft 41 via the first drive belt 71A (see FIG. 4). When the first drive motor 71 rotates, the first shaft 41 can rotate around the third axis J3.

[0030] The second drive motor 72 is connected to a second drive belt 72A, and is connected to the second shaft 42 via the second drive belt 72A (see FIG. 4). When the second drive motor 72 rotates, the second shaft 42 enables the upper connecting member 61 to move in the vertical direction.

[0031] Next, the configuration around the first shaft 41, the second shaft 42, and the upper connecting member 61 will be described with reference to FIGS.

[0032] As shown in FIG. 4, head covers 31A and 31B are arranged to surround second arm 30, first shaft 41 and second shaft 42 protruding upward from second arm 30, upper connecting member 61, and the like.

[0033] As described above, the first shaft 41 is connected to the first drive motor 71 via a pulley (not shown) and a first drive belt 71A. The second shaft 42 is connected to the second drive motor 72 via a pulley (not shown) and a second drive belt 72A.

[0034] The first shaft 41 is connected to the first drive belt 71A via a reducer (not shown) that rotatably supports the outer periphery of the first shaft 41. The upper end 41a of the first shaft 41 is rotatably supported by a bearing 41A provided on the upper connecting member 61. Specifically, the upper end 41a of the first shaft 41 is attached in a state in which the position of the upper part is regulated by the bearing 41A.

[0035] The first shaft 41 is supported by the second arm 30 via a ball spline nut (not shown) so as to be rotatable and movable up and down. The first shaft 41 is supported by the lower connecting member 62 so as to be rotatable.

[0036] The outer periphery of the second shaft 42 is a ball screw, and an upper end 42a is fixed to a ball screw nut 42A. A lower end 42b of the second shaft 42 is rotatably supported by a bearing 42B. The second shaft 42 is rotatably supported by the upper connecting member 61.

[0037] That is, the upper connecting member 61 rotatably supports the upper end portion 41a of the first shaft 41 and also rotatably supports the second shaft 42. When the second shaft 42 rotates, the upper connecting member 61 and the first shaft 41 can move up and down along the ball screw axis BS.

[0038] In this way, the inertial sensor 80 is disposed on the upper connecting member 61, which is movable along the ball screw shaft BS, and therefore can detect vibrations in the direction along the third axis J3, which slides vertically. In addition, by detecting horizontal vibrations of the second arm 30, a more reliable SCARA robot 100 can be provided.

[0039] A support member 90 (see FIGS. 5 and 6) is erected on the second arm 30. The support member 90 is wall-shaped and is disposed inside the head cover 31B. Because the support member 90 is disposed inside the head cover 31B in this manner, it is possible to prevent lubricating oil adhering to the support member 90 from adhering to the exterior head cover 31B.

[0040] The support member 90 rotatably supports the end of the second shaft 42. In this way, since the second shaft 42 is supported by the support member 90, it is possible to suppress vibrations of the upper connecting member 61 that connects the second shaft 42 and the first shaft 41, and the detection accuracy of the inertial sensor 80 can be improved.

[0041] Additionally, the upper connecting member 61 is connected to the third shaft 43 (see FIGS. 5 and 6). Specifically, the third shaft 43 is slidably supported by the second arm 30. As shown in FIG. 6, the third shaft 43 has a third shaft 43A disposed in the +Y direction and a third shaft 43B disposed in the -Y direction.

[0042] The two third shafts 43A, 43B have upper end portions 43Aa, 43Ba fixed to the upper connecting member 61. Specifically, the first shaft 41 to the third shafts 43A, 43B are arranged approximately evenly spaced apart on all four sides so as to surround the center of the upper connecting member 61, as shown in FIGS.

[0043] In this way, since the upper connecting member 61 is connected to three or more shafts, it is possible to stably support the upper connecting member 61 and suppress vibration of the upper connecting member 61. Therefore, the detection accuracy of the inertial sensor 80 can be improved.

[0044] Wiring (not shown) connecting the inertial sensor 80 and the control device 200 is attached to, for example, the support member 90. Because the wiring is attached to the support member 90 in this way, it is possible to suppress the wiring from shaking compared to when the wiring is not attached anywhere, and it is possible to suppress vibration of the inertial sensor 80 connected to the wiring. Therefore, it is possible to suppress deterioration in the detection accuracy of the inertial sensor 80.

[0045] The two third shafts 43A, 43B have their lower ends 43Ab, 43Bb fixed to the lower connecting member 62. The two third shafts 43A, 43B are slidably supported by the second arm 30. Therefore, the upper connecting member 61 and the lower connecting member 62 move together when the first shaft 41 moves up and down along the third axis J3.

[0046] In this way, the inertial sensor 80 is disposed on the upper connecting member 61, which is movable along the ball screw shaft BS, and can detect vibrations along the third axis J3, which slides vertically. This suppresses vertical vibrations, enabling efficient transport of batteries, such as automotive lithium-ion batteries, which are heavy due to their large capacity and contain liquids such as electrolytes. While it was possible to indirectly detect vibrations along the third axis J3 in the past, direct detection was not possible, resulting in poor detection accuracy. Furthermore, if the inertial sensor 80 were disposed directly on the first shaft 41, the inertial sensor 80 would rotate and its axis would become unstable, making it difficult to detect vibrations.

[0047] As described above, the SCARA robot 100 of this embodiment comprises a base 10, a first arm 20 connected to the base 10 and rotating around a first axis J1, a second arm 30 connected to the first arm 20 and rotating around a second axis J2 parallel to the first axis J1, a first shaft 41 attached to the second arm 30, movable along a third axis J3 parallel to the second axis J2, and rotating around the third axis J3, a second shaft 42 attached to the second arm 30 and extending along a ball screw axis BS parallel to the third axis J3, an upper connecting member 61 attached to the second shaft 42, rotatably supporting an upper end 41a of the first shaft 41 and movable along the ball screw axis BS, and an inertial sensor 80 arranged on the upper connecting member 61 for detecting at least one of acceleration and angular velocity.

[0048] With this configuration, the inertial sensor 80 is disposed on the upper connecting member 61, which is movable along the ball screw shaft BS, and therefore can detect vibrations along the third axis J3, which slides in the vertical direction. Therefore, in addition to detecting vibrations in the vertical direction, it is possible to detect vibrations in the horizontal direction of the second arm 30, for example, thereby providing a more reliable SCARA robot 100.

[0049] Furthermore, the upper connecting member 61 is a metal part that is thick and highly rigid, which means that noise is less likely to be picked up when detected by the inertial sensor 80. As a result, it is possible to obtain accurate data regarding vertical movement that can be used for feedback to improve positional accuracy and suppress vibrations.

[0050] Furthermore, in the SCARA robot 100 of this embodiment, the second arm 30 is provided with a support member 90, which preferably supports the end of the second shaft 42. With this configuration, since the end of the second shaft 42 is supported by the support member 90, it is possible to suppress vibrations of the upper connecting member 61 that connects the second shaft 42 and the first shaft 41, and it is possible to improve detection accuracy.

[0051] Furthermore, in the SCARA robot 100 of this embodiment, the support member 90 is preferably wall-shaped and disposed inside the head cover 31B made of resin, metal, etc. With this configuration, the support member 90 is disposed inside the head cover 31B, so that, for example, lubricating oil adhering to the support member 90 can be prevented from adhering to the exterior head cover 31B.

[0052] Furthermore, in the SCARA robot 100 of this embodiment, it is preferable that the upper connecting member 61 is connected to the third shafts 43A and 43B supported by the second arm 30. With this configuration, the upper connecting member 61 is connected to the third shafts 43A and 43B in addition to the first shaft 41 and the second shaft 42, and is therefore connected to three or more components. This makes it possible to suppress vibrations of the first shaft 41, the second shaft 42, the third shafts 43A and 43B, and the upper connecting member 61, and improves the detection accuracy of the inertial sensor 80.

[0053] Furthermore, in the SCARA robot 100 of this embodiment, the inertial sensor 80 is preferably disposed on the upper surface of the upper connecting member 61. With this configuration, the inertial sensor 80 is disposed on the upper surface of the upper connecting member 61, and therefore, even when the upper connecting member 61 repeatedly moves along the ball screw shaft BS, it is possible to prevent the inertial sensor 80 from falling. Furthermore, compared to when the inertial sensor 80 is disposed on the lower surface of the upper connecting member 61, it is possible to prevent the wiring connected to the inertial sensor 80 from coming into contact with other components.

[0054] Furthermore, in the SCARA robot 100 of this embodiment, the inertial sensor 80 is connected to the outside via a wire, and the wire is preferably attached to the support member 90. With this configuration, since the wire is attached to the support member 90, it is possible to suppress the wire from shaking compared to when the wire is not attached anywhere, and it is possible to suppress vibration of the inertial sensor 80 connected to the wire. Therefore, it is possible to suppress deterioration in the detection accuracy of the inertial sensor 80.

[0055] A modification of the above embodiment will now be described.

[0056] As described above, the control device 200 is not limited to making corrections in the direction along the third axis J3 based on the data detected by the inertial sensor 80, but may also make at least one of corrections in the direction of rotation around the first axis J1, corrections in the direction of rotation around the second axis J2, and corrections in the direction of rotation around the third axis J3 in addition to the above-mentioned corrections, and may also make the following processing in addition to the above-mentioned corrections.

[0057] The control device 200 includes, for example, a filter processor (not shown). The filter processor receives a signal from the inertial sensor 80 and controls the operating frequency of the SCARA robot 100. Specifically, for multiple movements included in a single task, the filter processor switches the operating frequency component to be removed from the torque control signal based on the vibration data obtained from the inertial sensor 80. For example, after removing operating frequency component A from a certain movement, the filter processor removes operating frequency component B from the next movement. By performing such processing, when a single task includes multiple movements, resonance in the posture at the end of each movement can be reduced. This prevents torque disturbances and abnormal noise. Furthermore, the next movement can be started in a shorter time than when the vibration of the SCARA robot 100 is waited for to converge to a predetermined value or below before starting the next movement.

[0058] As described above, it is preferable that the robot system 1000 of the modified example includes the above-described SCARA robot 100 and a control device 200 that controls the SCARA robot 100 and also controls the operating frequency of the SCARA robot 100 by receiving a signal from the inertial sensor 80. With this configuration, since the above-described SCARA robot 100 and control device 200 are included, it is possible to detect vibrations, and a highly reliable robot system 1000 can be provided.

[0059] As described above, the support member 90 is not limited to being disposed inside the head cover 31B, and may be configured to form part of the exterior of the head cover 31B, etc. Specifically, the head cover 31B is not covered with the support member 90 and is simply disposed in the +X direction or +Z direction.

[0060] As described above, in the modified SCARA robot 100, it is preferable that the support member 90 is wall-shaped and becomes part of the exterior together with the head cover 31B made of resin, metal, etc. With this configuration, since the support member 90 becomes part of the exterior, there is no need to provide a separate head cover 31B, and the number of parts can be reduced.

[0061] As described above, the wiring drawn from the inertial sensor 80 is not limited to being attached to the support member 90, and may be arranged, for example, so as to pass through the second shaft 42. Specifically, a hollow through-hole is formed inside the second shaft 42. A tubular member is placed inside the through-hole, and the wiring is placed inside the tubular member. The tubular member is a protective member that prevents the wiring from rotating together with the second shaft 42 as it rotates.

[0062] As described above, in the modified SCARA robot 100, the second shaft 42 is hollow and has a tubular member disposed therein, and the inertial sensor 80 is connected to the outside via a wiring, which is preferably disposed within the tubular member. With this configuration, the wiring passes through the tubular member and is supported within the second shaft 42. This prevents the wiring from coming into contact with components other than the tubular member, even when the second shaft 42 moves along the ball screw axis BS, thereby preventing the wiring from vibrating. Furthermore, the wiring is prevented from interfering with the movement of the first shaft 41 and the third shafts 43A and 43B. [Explanation of symbols]

[0063] 10...base, 11...piping, 12...drive motor, 13...reduction gear, 20...first arm, 21...reduction gear, 22...drive motor, 30...second arm, 31A, 31B...head cover, 41...first shaft, 41a...upper end, 42...second shaft, 42a...upper end, 42A...ball screw nut, 42b...lower end, 43, 43A, 43B...third shaft, 43Aa, 43Ba...upper end, 43Ab, 43Bb...lower end, 61...upper connecting member as connecting member, 62...lower connecting member, 71...first drive motor, 71A...first drive belt, 72...second drive motor, 72A...second drive belt, 80...inertia sensor, 90...support member, 100...SCARA robot, 200...control device, 210...wiring, 1000...robot system.

Claims

1. The base and a first arm connected to the base and rotating about a first axis; a second arm connected to the first arm and rotating about a second axis parallel to the first axis; a first shaft provided on the second arm, movable along a third axis parallel to the second axis, and rotatable about the third axis; a second shaft provided on the second arm and extending along a fourth axis parallel to the third axis; a connecting member provided on the second shaft, rotatably supporting an end of the first shaft, and movable along the fourth axis; an inertial sensor disposed on the connecting member and configured to detect at least one of acceleration and angular velocity; A SCARA robot comprising:

2. 2. The SCARA robot according to claim 1, The second arm is provided with a support member, The support member supports an end of the second shaft.

3. 3. The SCARA robot according to claim 2, The support member is wall-shaped and forms part of the exterior together with a resin cover or a metal cover.

4. 3. The SCARA robot according to claim 2, The support member is a wall-shaped member disposed inside a resin cover or a metal cover.

5. 2. The SCARA robot according to claim 1, The coupling member is connected to a third shaft supported by the second arm.

6. 2. The SCARA robot according to claim 1, The inertial sensor is disposed on an upper surface of the connecting member.

7. 3. The SCARA robot according to claim 2, the inertial sensor is connected to an external device via a wire; The wiring is attached to the support member.

8. 2. The SCARA robot according to claim 1, The second shaft is hollow and has a tube member disposed therein. the inertial sensor is connected to an external device via a wire; The wiring is disposed within the pipe member.

9. The SCARA robot according to any one of claims 1 to 8, a control device that controls the SCARA robot and receives a signal from the inertial sensor to control an operating frequency of the SCARA robot; A robot system comprising:

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