Horizontal multi-joint robot

Abstract

This invention provides a highly versatile horizontal multi-joint robot. A horizontal multi-joint robot is characterized by comprising: a base; 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 third arm connected to the second arm and moving along a third axis parallel to the second axis; a limiting member for limiting the rotation of the third arm about the third axis; a drive unit for moving the third arm along the third axis; and a mounting part for mounting the drive unit that rotates the third arm about the third axis, wherein the horizontal multi-joint robot does not have a drive unit for rotating the third arm about the third axis.

Description

[0001] This application is a divisional application based on the patent application filed on March 5, 2020, with application number 202010148105.7 and invention title "Horizontal Multi-Joint Robot". Technical Field

[0002] This invention relates to horizontal multi-joint robots. Background Technology

[0003] In recent years, due to rising labor costs and labor shortages, factories have accelerated the automation of tasks previously performed manually through various robots and their peripheral equipment. Among these robots, horizontal articulated robots, such as the SCARA robot shown in Patent Document 1, are widely used in simple conveying and screw-tightening processes.

[0004] The SCARA robot described in Patent Document 1 has a first arm that rotates about a first axis, a second arm that rotates about a second axis, and a third arm that rotates about a third axis and moves in the third axis. Furthermore, the third axis is driven using a ball screw spline to achieve movement in both directions.

[0005] Patent Document 1: Japanese Patent Application Publication No. 2009-257458

[0006] However, in some tasks performed with SCARA robots, it is not necessary to rotate the third arm around a third axis. But in the prior art, users cannot restrict the rotation of the SCARA robot relative to a specific axis of rotation according to the task. Summary of the Invention

[0007] This invention is made to solve at least a part of the above-mentioned technical problems, and can be achieved in the following ways.

[0008] The horizontal joint robot of this application example is characterized by comprising: a base; 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 third arm connected to the second arm and moving along a third axis parallel to the second axis; a limiting member for limiting the rotation of the third arm about the third axis; a drive unit for moving the third arm along the third axis; and a mounting unit for mounting the drive unit that rotates the third arm about the third axis, wherein the horizontal joint robot does not have a drive unit for rotating the third arm about the third axis. Attached Figure Description

[0009] Figure 1 This is a side view illustrating an embodiment of the horizontal multi-joint robot of the present invention.

[0010] Figure 2 yes Figure 1 The diagram shows a block diagram of the robot system.

[0011] Figure 3 It is shown Figure 1 The image shows an internal side view of the second arm of a horizontal multi-jointed robot.

[0012] Figure 4 It is shown Figure 1 The image shows an internal side view of the second arm of a horizontal multi-jointed robot.

[0013] Figure 5 yes Figure 4 An enlarged sectional view of the area indicated by the dashed line.

[0014] Figure 6 yes Figure 4 The top view of the limiting component shown.

[0015] Explanation of reference numerals in the attached figures

[0016] 1…Control device; 2…Robot; 3…Thread limit gauge; 5…Limiting component; 7…End effector; 11…Robot control unit; 12…Motor control unit; 13…Display control unit; 14…Storage unit; 15…Receiver; 16…Decision unit; 20…Robot arm; 21…Base; 22…First arm; 23…Second arm; 24…Third arm; 25…Drive unit; 26…Drive unit; 27…U drive unit; 28…Z drive unit; 29…Angular velocity sensor; 31…Holding part; 32…Go end gauge; 33…No end gauge; 41…Display device; 42…Input device; 51…Through hole; 52…Screw hole; 53…Screw hole; 61…Screw; 62…Screw; 71…Mounting part; 72…Motor; 100…Robot system; 200…Cable; 220…Shell Body; 230…shell; 231…bottom plate; 232…top plate; 233…side wall; 234…inclined part; 241…shaft part; 242…rotary support component; 243…ball screw nut; 244…spline nut; 245…outer cylinder; 246…rotating body; 248…screw hole; 249…cylinder component; 251…motor; 252…reducer; 253…position sensor; 261…motor; 262…reducer; 263…position sensor; 270…carrying part; 271…motor; 272…reducer; 273…position sensor; 274…belt; 275…pulley; 281…motor; 282…reducer; 283…position sensor; 284…belt; 285…pulley; 290…force detection part; O1…first shaft; O2…second shaft; O3…third shaft. Detailed Implementation

[0017] The horizontal multi-joint robot of the present invention will now be described in detail based on the preferred embodiments shown in the accompanying drawings.

[0018] Implementation

[0019] Figure 1 This is a side view illustrating an embodiment of the horizontal multi-joint robot of the present invention. Figure 2 yes Figure 1 The diagram shows a block diagram of the robot system. Figure 3 It is shown Figure 1 The image shows an internal side view of the second arm of a horizontal multi-jointed robot. Figure 4 It is shown Figure 1 The image shows an internal side view of the second arm of a horizontal multi-jointed robot. Figure 5 yes Figure 4 An enlarged sectional view of the area indicated by the dashed line. Figure 6 yes Figure 4 The top view of the limiting component shown.

[0020] In addition, Figure 1 , Figure 3 , Figure 4 For ease of explanation, the diagram illustrates three mutually orthogonal axes: the x-axis, y-axis, and z-axis. Furthermore, the direction parallel to the x-axis will be referred to as the "x-axis direction," the direction parallel to the y-axis as the "y-axis direction," and the direction parallel to the z-axis as the "z-axis direction." Additionally, the front end of each arrow in the diagram will be referred to as "+" (positive), the base end as "-" (negative), the direction parallel to the +x-axis direction as the "+x-axis direction," the direction parallel to the -x-axis direction as the "-x-axis direction," the direction parallel to the +y-axis direction as the "+y-axis direction," the direction parallel to the -y-axis direction as the "-y-axis direction," the direction parallel to the +z-axis direction as the "+z-axis direction," and the direction parallel to the -z-axis direction as the "-z-axis direction." Furthermore, the direction around the z-axis and the direction around an axis parallel to the z-axis will be referred to as the "u-axis direction."

[0021] In addition, for ease of explanation, the following will also... Figure 1 In this context, the +z axis direction, i.e., the upper side, is referred to as "up," and the -z axis direction, i.e., the lower side, is referred to as "down." Additionally, for robotic arm 20, it will also... Figure 1 The side of the base 21 is called the "base end", and the opposite side, the end effector 7 side, is called the "front end". Additionally, Figure 1 In this context, the z-axis direction (vertical direction) is set as the "vertical direction," and the x-axis and y-axis directions (horizontal direction) are set as the "horizontal direction."

[0022] Figure 1 as well as Figure 2The robot system 100 shown is, for example, a device used in operations such as holding, transporting, assembling, and inspecting workpieces (objects) such as electronic components and electronic devices. The robot system 100 includes a control device 1, a robot 2, an end effector 7, a display device 41, and an input device 42.

[0023] In addition, in the structure shown in the figure, the control device 1 is located on the outside of the robot 2, but it is not limited to this and can also be built into the robot 2.

[0024] Furthermore, in the illustrated structure, robot 2 and control device 1 are electrically connected via cable 200 (hereinafter also referred to as "connection"), but this is not a limitation; cable 200 can also be omitted and communication can be conducted wirelessly. That is, robot 2 and control device 1 can be connected via wired communication, or they can be connected via wireless communication.

[0025] robot

[0026] Robot 2 is a horizontal multi-joint robot, namely a SCARA robot.

[0027] like Figure 1 , Figure 3 as well as Figure 4 As shown, robot 2 includes a base 21, a first arm 22, a second arm 23, a third arm 24 serving as a working head, and a limiting component 5. The robotic arm 20 is composed of the first arm 22, the second arm 23, and the third arm 24.

[0028] In addition, the robot 2 includes a drive unit 25 for rotating the first arm 22 relative to the base 21, a drive unit 26 for rotating the second arm 23 relative to the first arm 22, a u-drive unit 27 for rotating the shaft portion 241 of the third arm 24 relative to the second arm 23, a z-drive unit 28 for moving the shaft portion 241 relative to the second arm 23 in the z-axis direction, and an angular velocity sensor 29.

[0029] like Figure 1 as well as Figure 2 As shown, the drive unit 25 is built into the housing 220 of the first arm 22, and has a motor 251 that generates driving force, a reducer 252 that reduces the driving force of the motor 251, and a position sensor 253 that detects the rotation angle of the rotating shaft of the motor 251 or the reducer 252.

[0030] The drive unit 26 is built into the housing 230 of the second arm 23 and has a motor 261 that generates driving force, a reducer 262 that reduces the driving force of the motor 261, and a position sensor 263 that detects the rotation angle of the rotating shaft of the motor 261 or the reducer 262.

[0031] The drive unit 27 is built into the housing 230 of the second arm 23 and includes a motor 271 that generates driving force, a reducer 272 that reduces the driving force of the motor 271, and a position sensor 273 that detects the rotation angle of the rotating shaft of the motor 271 or the reducer 272.

[0032] The z-drive unit 28 is built into the housing 230 of the second arm 23 and has a motor 281 that generates driving force, a reducer 282 (not shown) that reduces the driving force of the motor 281, and a position sensor 283 that detects the rotation angle of the rotation axis of the motor 281 or the reducer 282.

[0033] Motors 251, 261, 271, and 281 can be servo motors such as AC servo motors and DC servo motors.

[0034] Furthermore, the speed reducers 252, 262, 272, and 282 can be, for example, planetary gear type speed reducers, wave gear devices, etc. Additionally, the position sensors 253, 263, 273, and 283 can be, for example, angle sensors.

[0035] Drive units 25, 26, u-drive unit 27, and z-drive unit 28 are each connected to a corresponding motor driver (not shown), and are controlled by the robot control unit 11 of the control device 1 via the motor driver. It should be noted that each reducer can also be omitted.

[0036] Furthermore, the angular velocity sensor 29 is built into the second arm 23. Therefore, the angular velocity of the second arm 23 can be detected. Based on the detected angular velocity information, the control device 1 controls the robot 2. In addition, the angular velocity sensor 29 is located on the -y axis side further than the drive units 26-28, that is, on the side farther from the base 21 than the drive units 26-28.

[0037] The base 21 is fixed to the ground (not shown) for example by bolts. A first arm 22 is connected to the upper end of the base 21. The first arm 22 is rotatable relative to the base 21 about a first axis O1 along the vertical direction. When driven by the drive unit 25 that rotates the first arm 22, the first arm 22 rotates relative to the base 21 about the first axis O1 in the horizontal plane. In addition, the drive (rotation amount) of the first arm 22 relative to the base 21 can be detected by the position sensor 253.

[0038] Furthermore, a second arm 23 is connected to the front end of the first arm 22. The second arm 23 is rotatable relative to the first arm 22 about a second axis O2 along the vertical direction. The axial direction of the first axis O1 is the same as the axial direction of the second axis O2. That is, the second axis O2 is parallel to the first axis O1. If the drive unit 26 that rotates the second arm 23 is driven, the second arm 23 rotates relative to the first arm 22 about the second axis O2 in the horizontal plane. In addition, the drive of the second arm 23 relative to the first arm 22, specifically the amount of rotation, can be detected by the position sensor 263.

[0039] Additionally, the second arm 23 has a housing 230, which has a bottom plate 231, a top plate 232, and sidewalls 233 connecting them. Inside the housing 230, on the bottom plate 231, a drive unit 26, a u drive unit 27, a z drive unit 28, and an angular velocity sensor 29 are arranged sequentially from the +y axis side.

[0040] Additionally, the housing 230 has an inclined portion 234 located between the top plate 232 and the side wall 233. This inclined portion 234 is provided on the -y axis side of the top plate 232. Furthermore, this inclined portion 234 is configured to be inclined relative to the z axis.

[0041] In addition, such as Figure 3 as well as Figure 4 As shown, a third arm 24 is provided at the front end of the second arm 23. The third arm 24 has a shaft portion 241 and a rotatable support member 242 that supports the shaft portion 241 so that it can rotate.

[0042] The shaft 241 is rotatable relative to the second arm 23 about a third axis O3 along the vertical direction and is movable in the vertical direction (lifting). The shaft 241 is the third arm of the robotic arm 20 and is the foremost arm of the robotic arm 20.

[0043] Additionally, a ball screw nut 243 and a spline nut 244 are fixed midway along the long side of the shaft 241. These ball screw nuts 243 and spline nuts 244 are arranged separately in this order, starting from the +z axis side.

[0044] Additionally, a swivel support member 242 is provided on the -z axis side of the spline nut 244. This swivel support member 242 has an outer cylinder 245 and a rotating body 246 disposed inside the outer cylinder 245. The outer cylinder 245 is fixed to a base plate 231 within the housing 230 of the second arm 23. On the other hand, the rotating body 246 is fixed to the shaft portion 241 and supported by the outer cylinder 245 so that it can rotate together with the shaft portion 241 about the u-axis.

[0045] If driven by the u-drive unit 27 that rotates the shaft 241, the shaft 241 will rotate in both directions around the z-axis. Furthermore, the amount of rotation of the shaft 241 relative to the second arm 23 can be detected by the position sensor 273.

[0046] Furthermore, if the z-drive unit 28, which moves the shaft 241 in the z-axis direction, is driven, the shaft 241 moves in the vertical direction, i.e., the z-axis direction. Additionally, the amount of movement of the shaft 241 relative to the second arm 23 in the z-axis direction can be detected by the position sensor 283.

[0047] Furthermore, various end effectors are detachably connected to the front end of the shaft 241. The end effector is not particularly limited; examples include end effectors for holding conveyed objects, end effectors for machining processed objects, and end effectors for inspection. In this embodiment, end effector 7 is detachably connected. End effector 7 will be described in detail later.

[0048] It should be noted that in this embodiment, the end effector 7 is not a component of the robot 2, but some or all of the end effector 7 may be components of the robot 2. Similarly, in this embodiment, the end effector 7 is not a component of the robotic arm 20, but some or all of the end effector 7 may be components of the robotic arm 20.

[0049] End effector

[0050] like Figure 1 As shown, the end effector 7 includes a force detection unit 290, a mounting portion 71 mounted on the force detection unit 290, a motor 72 provided on the mounting portion 71, and a thread limit gauge 3 detachably and concentrically mounted on the rotating shaft of the motor 72. In this end effector 7, the force detection unit 290 is detachably connected to the front end of the shaft portion 241, either directly or via a connecting member (not shown). Furthermore, the central axis of the shaft portion 241, i.e., the third shaft O3, the rotating shaft of the motor 72, and the central axis of the thread limit gauge 3 are aligned. That is, when viewed axially from the third shaft O3, the third shaft O3, the motor 72, and the thread limit gauge 3 overlap.

[0051] Furthermore, the thread limit gauge 3 is an example of a thread gauge, which has a columnar gripping part 31, a go gauge 32 with an external thread at one end of the gripping part 31, and a no-go gauge 33 with an external thread at the other end of the gripping part 31. Regarding this thread limit gauge 3, when using the go gauge 32, the end of the gripping part 31 with the no-go gauge 33 is mounted to the rotating shaft of the motor 72, and the go gauge 32 is positioned at the front end. Similarly, when using the no-go gauge 33, the end of the gripping part 31 with the go gauge 32 is mounted to the rotating shaft of the motor 72, and the no-go gauge 33 is positioned at the front end.

[0052] In addition, the motor 72 is not particularly limited, and for example, servo motors such as AC servo motors, DC servo motors, and stepper motors can be used.

[0053] Additionally, the end effector 7 has an angle sensor (not shown) that detects the rotation angle of the rotating shaft of the motor 72, and the rotation angle of the rotating shaft of the motor 72 can be detected by this position sensor.

[0054] Furthermore, the force detection unit 290 may be composed of, for example, a force sensor that detects the force applied to the thread limit gauge 3. It should be noted that in this embodiment, the force detection unit 290 is a component of the end effector 7, but it is not limited thereto; it may also be a component of the robot 2 or the robotic arm 20.

[0055] In this end effector 7, compared with the case where the power transmission mechanism such as gears or belts is located between the rotating shaft of the motor 72 and the thread limit gauge 3, the decrease in rotational accuracy due to backlash can be suppressed.

[0056] It should be noted that the thread limit gauge 3 is not limited to such a structure. For example, it can also be a thread limit gauge that is used with only a go gauge and a thread limit gauge that is only a no-go gauge.

[0057] In addition, in this embodiment, the end effector 7 is detachable from the robotic arm 20, but it is not limited to this. For example, the end effector 7 may not be detachable from the robotic arm 20, or the force detection unit 290 may not be detachable from the robotic arm 20.

[0058] Control device

[0059] like Figure 2 As shown, the control device 1 includes a robot control unit 11, a motor control unit 12 (end-effector control unit), a display control unit 13, a storage unit 14, a receiving unit 15, and a determination unit 16, which respectively control the drive of each part of the robot system 100, such as the robot 2, the motor 72 of the end-effector 7, and the display device 41.

[0060] Furthermore, the control device 1 is configured to enable communication between the robot control unit 11, the motor control unit 12, the display control unit 13, the storage unit 14, the receiving unit 15, and the determination unit 16. That is, the robot control unit 11, the motor control unit 12, the display control unit 13, the storage unit 14, the receiving unit 15, and the determination unit 16 are connected to each other via wired or wireless communication.

[0061] In addition, the robot 2, display device 41, input device 42 and end effector 7 are respectively connected to the control device 1 via wired or wireless communication.

[0062] Robot Control Department

[0063] The robot control unit 11 controls the drive of the robot 2, such as the robotic arm 20. The robot control unit 11 is a computer with an operating system or similar programs installed. This robot control unit 11 includes, for example, a CPU as a processor, RAM, and ROM storing programs. Furthermore, the functions of the robot control unit 11 can be achieved, for example, by executing various programs through the CPU.

[0064] Motor control unit

[0065] The motor control unit 12 controls the drive of the motor 72. The motor control unit 12 is a computer with an operating system or similar programs installed. This motor control unit 12 includes, for example, a CPU as a processor, RAM, and ROM storing programs. Furthermore, the functions of the motor control unit 12 can be implemented, for example, by executing various programs through the CPU.

[0066] Display Control Unit

[0067] The display control unit 13 has the function of causing the display device 41 to display various screens, characters, etc. That is, the display control unit 13 controls the driving of the display device 41. The function of the display control unit 13 can be implemented, for example, through a GPU.

[0068] Storage Department

[0069] Storage unit 14 has the function of storing various information (including data, programs, etc.). Storage unit 14 stores control programs, etc. The functions of storage unit 14 can be implemented through external storage devices (not shown), such as ROM.

[0070] Receiving Department

[0071] The receiving unit 15 has the function of receiving input from the input device 42. This function of the receiving unit 15 can be implemented, for example, through an interface circuit. It should be noted that, for example, when using a touch panel, the receiving unit 15 functions as an input detection unit that detects the contact between the user's finger and the touch panel.

[0072] Display device

[0073] The display device 41 includes a monitor (not shown) consisting of, for example, a liquid crystal display or an EL display, and has functions such as displaying various images (including windows and other screens), characters, etc.

[0074] Input device

[0075] The input device 42 may be, for example, a mouse or a keyboard. Thus, by operating the input device 42, the user can give instructions to the control device 1 for various processing tasks.

[0076] Specifically, users can instruct the control device 1 by clicking on various screens (windows, etc.) displayed on the display device 41 using the mouse of the input device 42, or by inputting characters, numbers, etc. using the keyboard of the input device 42.

[0077] It should be noted that, in this embodiment, a display input device that combines both display device 41 and input device 42 can be provided instead of display device 41 and input device 42. As a display input device, for example, an electrostatic touch panel, a pressure-sensitive touch panel, or a similar touch panel can be used. Alternatively, the input device 42 can also be a structure that recognizes voice or other sounds.

[0078] Next, the interior of the second arm 23 will be described.

[0079] In robot 2, a first state and a second state can be adopted. In the first state, such as... Figure 3 As shown, within the housing 230 of the second arm 23, there are a u-drive unit 27 for rotating the third arm 24 about the z-axis, a z-drive unit 28 for moving the third arm 24 in the z-axis direction, a belt 274, and a belt 284. In the second state, as... Figure 4 As shown, a z-drive unit 28 and a band 284 are provided, while a u-drive unit 27 and a band 274 are omitted.

[0080] like Figure 3 As shown, in addition to the aforementioned motor 271, reducer 272, and position sensor 273, the u-drive unit 27 also has a pulley 275. They are arranged in the following order from the +z axis side: position sensor 273, motor 271, reducer 272, and pulley 275. The pulley 275 is fixed to the core of the reducer 272, and the rotational force of the motor 271 is reduced by the reducer 272 and transmitted to the pulley 275.

[0081] Furthermore, pulley 275 is connected to spline nut 244 located on shaft 241 via belt 274. Belt 274 is an annular belt wound around pulley 275 and spline nut 244, and has teeth (not shown) on its inner side, i.e., on the sides of pulley 275 and spline nut 244. The teeth of belt 274 mesh with the teeth (not shown) of pulley 275 and spline nut 244, respectively.

[0082] In this u-drive unit 27, the rotational force of the motor 271 is transmitted to the belt 274 via the reducer 272 and pulley 275, causing the belt 274 to rotate. Through the rotation of the belt 274, its rotational force is transmitted to the shaft 241 via the spline nut 244. This rotational force is transmitted to the shaft 241 via the spline groove, causing the shaft 241 to move in the u-axis direction, i.e., to rotate.

[0083] Furthermore, the u-drive unit 27 is disposed in the mounting portion 270. The mounting portion 270 refers to the space in which the u-drive unit 27 is disposed. For example, when the u-drive unit 27 is disposed at the bottom of the housing 230, it refers to the space from the bottom to the height at which the u-drive unit 27 is disposed. Alternatively, when the u-drive unit 27 is fixed to the inner wall of the housing 230 by a fixing member (not shown) and is separated from the bottom of the housing 230, it refers to the space within the housing 230 in which the u-drive unit 27 is actually disposed. Thus, the space within the housing 230 in which the u-drive unit 27 can be disposed is referred to as the mounting portion 270.

[0084] like Figure 3 As shown, in addition to the aforementioned motor 281, reducer 282, and position sensor 283, the z-drive unit 28 also has a pulley 285. They are arranged in the following order from the +z axis side: position sensor 283, motor 281, pulley 285, and reducer 282. The pulley 285 is fixed to the core of the reducer 282, and the rotational force of the motor 281 is reduced by the reducer 282 and transmitted to the pulley 285.

[0085] Furthermore, pulley 285 is connected to ball screw nut 243 located on shaft 241 via belt 284. Belt 284 is an annular belt wound around pulley 285 and ball screw nut 243, and has teeth (not shown) on its inner side, i.e., on the side of pulley 285 and ball screw nut 243. The teeth of belt 284 mesh with the teeth (not shown) of pulley 285 and ball screw nut 243, respectively.

[0086] In this z-drive unit 28, the rotational force of the motor 281 is transmitted to the belt 284 via the reducer 282 and pulley 285, causing the belt 284 to rotate. Through the rotation of the belt 284, its rotational force is transmitted to the shaft 241 via the ball screw nut 243. This rotational force is redirected by the ball screw groove of the shaft 241, thereby allowing the shaft 241 to move in the z-axis direction, i.e., to move up and down.

[0087] like Figure 4 As shown, the second state is a state in which the aforementioned z-drive unit 28 is provided, but the u-drive unit 27 of the mounting portion 270 is omitted, and the belt 274 and spline nut 244 are also omitted. In addition, in the second state, a limiting member 5 is provided, which limits the rotation of the shaft portion 241 of the third arm 24 around the third axis O3, that is, limits the rotation of the shaft portion 241 of the third arm 24 in the u-axis direction.

[0088] like Figure 4 as well as Figure 5 As shown, the limiting member 5 is detachable from the rotational support member 242 of the third arm 24 by means of screws 61 and 62. The limiting member 5 is a plate member having a through hole 51 and a screw hole 52. The through hole 51 is a through portion that passes through the axial direction of the third shaft O3 and through which the third arm 24 is inserted. The screw hole 52 is for the screw 61, which is used to fix the limiting member 5 to the rotational support member 242, to be inserted. The through hole 51, screw hole 52, and screw hole 53 are each formed by through holes that pass through the thickness direction of the limiting member 5. With this limiting member 5, the shaft portion 241 can be inserted through the through hole 51 while being threaded and fixed as described later.

[0089] The insertion hole 51 is open to the side of the limiting member 5. That is, when viewed axially from the third shaft O3, the insertion hole 51, which is the insertion part, is a notch. Therefore, when assembling and disassembling the limiting member 5 relative to the shaft portion 241, it can be installed on the shaft portion 241 through the side-open portion of the insertion hole 51. In other words, the limiting member 5 can be provided from the side of the shaft portion 241. Therefore, when assembling and disassembling the limiting member 5, the cumbersome operation of pulling the shaft portion 241 out of the second arm 23 and assembling it is eliminated, and the assembly and disassembly of the limiting member 5 can be performed simply.

[0090] Additionally, the screw hole 52 is the part for inserting a screw 61 for threaded fixation. The screw 61, inserted into the screw hole 52 from the +z axis side, is fixed to the rotating body 246 of the rotary support component 242.

[0091] In addition, such as Figure 6As shown, there are four screw holes 52 in the illustrated structure, each consisting of an elongated hole. Each screw hole 52 is an arc-shaped bend along the circumference of the through hole 51. Therefore, when installing the limiting member 5, the shaft 241 can be rotated relative to the limiting member 5 to adjust its position around the u-axis, even with the screw 61 inserted but not tightened. Thus, the screw holes 52 are elongated holes and function as an adjustment mechanism for adjusting the position of the third arm 24 around the third axis O3.

[0092] The screw hole 53 is the part for threaded fastening by inserting a screw 62. The screw 62 is inserted from the -z axis side through the screw hole 248 formed in the outer cylinder 245 of the rotary support member 242 and the cylinder member 249 and is fixed in the screw hole 53. In addition, in the structure shown in the figure, the screw hole 53 is provided in two places, separated by the insertion hole 51.

[0093] Such a limiting member 5 is fixed to the rotary support member 242. That is, since the limiting member 5 is fixed to the outer cylinder 245 and the rotating body 246 of the rotary support member 242, the relative rotation of the outer cylinder 245 and the rotating body 246 is limited. As mentioned above, since the rotating body 246 is fixed to the shaft portion 241 and the outer cylinder 245 is fixed to the housing 230, by installing the limiting member 5, the rotation of the shaft portion 241 relative to the housing 230 is limited.

[0094] In the illustrated structure, robot 2 is equipped with an end effector 7 for threaded fastening. In this case, the shaft 241 rotates around the u-axis by driving the u-drive unit 27. In contrast, although not shown, in cases where the end effector, for example, uses suction to hold and transport a workpiece, driving the u-drive unit 27 is unnecessary. That is, the operation can be performed even without the u-drive unit 27. Furthermore, although driving the u-drive unit 27 is unnecessary, its inclusion reduces the overall load-bearing capacity of robot 2. Thus, in the prior art, it is impossible to select the optimal configuration based on the task.

[0095] In contrast, as mentioned earlier, robot 2 can take on a first state and a second state. In the first state, such as... Figure 3 As shown, both the u-drive unit 27 and the z-drive unit 28 are equipped with a second state, as follows: Figure 4 As shown, the u-drive unit 27 is omitted. Therefore, the required state can be selected according to the task, that is, the required configuration can be selected, thus solving the aforementioned technical problems. In other words, robot 2 has excellent versatility.

[0096] Furthermore, in the second state, since the rotation of the shaft 241 is restricted by the limiting member 5, it is possible to prevent the shaft 241 from rotating accidentally in the second state and thus hindering the operation.

[0097] The mounting portion 270 is located further away from the third arm 24 than the z-drive unit 28, which serves as the second drive unit. That is, when viewed from above along the axial direction of the third axis O3, the distance from the mounting portion 270 to the third arm 24 is greater than the distance from the z-drive unit 28, which serves as the second drive unit, to the third arm 24. This allows for easier assembly and disassembly of the u-drive unit 27.

[0098] As described above, robot 2 includes: a base 21; a first arm 22 connected to the base 21 and rotating about a first axis O1; a second arm 23 connected to the first arm 22 and rotating about a second axis O2 parallel to the first axis O1; a third arm 24 connected to the second arm 23 and moving along a third axis O3 parallel to the second axis O2; a limiting member 5 that limits the rotation of the third arm 24 about the third axis O3; and a mounting part 270 provided on the second arm 23, which mounts a u-drive unit 27, which serves as a first drive unit, for rotating the third arm 24. Furthermore, the limiting member 5 is detachably mounted on the third arm 24. Thus, robot 2 can limit the rotation of the third arm 24 about the third axis O3. Therefore, the required state can be selected according to the task, i.e., the required configuration can be selected, resulting in excellent versatility. Additionally, by mounting the limiting member 5 on the third arm 24 to limit the rotation of the third arm 24, the u-drive unit 27 can be omitted, which helps to increase the load-bearing capacity of robot 2. Furthermore, if the limiting member 5 is disengaged from the third arm 24 and the rotation of the third arm 24 is not restricted by the limiting member 5, the u-drive unit 27 can be placed on the mounting portion 270, and the third arm 24 can be rotated and driven.

[0099] The horizontal jointed robot of the present invention has been described above based on the illustrated embodiments, but the present invention is not limited thereto, and the structure of each part can be replaced with any structure having the same function. In addition, other arbitrary structures can be added.

[0100] Furthermore, in the aforementioned embodiment, the number of rotation axes of the robotic arm is three, but this is not a limitation in the present invention; the number of rotation axes of the robotic arm may, for example, be two or four or more. That is, in the aforementioned embodiment, the number of arms is three, but this is not a limitation in the present invention; the number of arms may, for example, be two or four or more.

Claims

1. A horizontal multi-joint robot, characterized in that, have: Base; The first arm is connected to the base and rotates about the first axis; The second arm is connected to the first arm and rotates about a second axis parallel to the first axis; The third arm is connected to the second arm and moves along a third axis parallel to the second axis; A limiting component restricts the third arm from rotating about the third axis; The first drive unit causes the third arm to move along the third axis; as well as The mounting section is capable of mounting the second drive unit that rotates the third arm about the third axis. The horizontal multi-joint robot can take on a first state and a second state. The first state is a state in which the limiting component is not set and the second drive unit is placed on the placement unit and the third arm can be rotated around the third axis. The second state is a state in which the second drive unit is not placed on the placement unit and the limiting component is set and the rotational drive of the third arm around the third axis is restricted.

2. The horizontal multi-joint robot according to claim 1, characterized in that, The third arm has a shaft and a rotary support component, the rotary support component supporting the shaft so that it can rotate. The limiting component is fixed to the rotating support component in a detachable manner.

3. The horizontal multi-joint robot according to claim 2, characterized in that, The limiting component is a plate component with a through portion and a screw hole. The through portion passes through the axial direction of the third shaft and through which the third arm is inserted. The screw hole is for inserting a screw to fix the limiting component to the rotary support component.

4. The horizontal multi-joint robot according to claim 3, characterized in that, The screw hole is an elongated hole.

5. The horizontal multi-joint robot according to claim 3 or 4, characterized in that, When viewed from the axial direction of the third axis, the insertion portion is a notch.

6. The horizontal multi-joint robot according to claim 1, characterized in that, When viewed from above along the axial direction of the third axis, the distance from the mounting portion to the third arm is greater than the distance from the first drive portion that moves the third arm along the third axis to the third arm.

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