Work device

Abstract

A work device (1) comprises: a linear motion mechanism unit (60) which has a linear actuator with two orthogonal axes; a rotation mechanism unit (80) which has a rotation actuator (Ra); and an angle control mechanism unit (7) which has rotation actuators (10) for positioning a work body (E) at angles corresponding to two rotational degrees of freedom. The work device (1) further comprises a control unit (70) that determines the positions and angles of the linear motion mechanism unit (60), the rotation mechanism unit (80), and the angle control mechanism unit (7) and that gives, to each actuator, a movement command. According to the movement command from the control unit (70), work is performed so that the distance between the attachment position of the work body and the work position becomes a specified value. The rotation mechanism unit (80) and / or the angle control mechanism unit (7) is mounted on the linear motion mechanism unit (60) so that, while a certain angle is kept between the rotation axis (C1) of the rotation mechanism unit (80) and the base end-side center axis (QA) of the angle control mechanism unit (7), the relative position between the rotation mechanism unit (80) and the angle control mechanism unit (7) can be changed.

Description

Work equipment Related Applications

[0001] This application claims priority from Japanese Patent Application No. 2024-045262, filed March 21, 2024, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a compact working device that can be used in equipment that requires high speed, high precision, a wide operating range, and fine movements, such as medical equipment or industrial equipment.

[0003] Patent Documents 1 and 2 propose configurations for a working apparatus that performs work on a workpiece using a working body. The apparatus shown in Figure 1 of Patent Document 1 discloses a mechanism for moving a head in three mutually orthogonal axial directions, i.e., the X-axis, Y-axis, and Z-axis, and a technique in which a working body is attached to the tip of the head via a rotation mechanism. Patent Document 2 discloses a technique for inspecting an item using a vertical articulated robot.

[0004] JP 2013-64644 A JP 2017-26441 A

[0005] In the configuration described in Patent Document 1, when working on the entire periphery of the side of a workpiece supported on a surface plate, it is necessary to move the workpiece in all directions around the workpiece, which leads to problems such as a large device size, a complex structure with a large number of parts, and increased manufacturing costs.

[0006] In the configuration of a vertical articulated robot such as that described in Patent Document 2, the movement amount of the entire robot is large, and therefore there is a problem in that providing a safety fence or the like increases the size of the entire device.

[0007] An object of the present invention is to provide a working device that can be made more compact than conventional structures and that can be manufactured at reduced cost.

[0008] The working device of the present invention is a working device comprising: a linear motion mechanism having two linear motion actuators whose movement directions are perpendicular to each other; a rotation mechanism having a rotary actuator that rotates the workpiece around one rotation axis; an angle control mechanism having a rotary actuator that positions the workpiece at an angle with two rotational degrees of freedom; and a control unit that determines the positions and angles of the linear motion mechanism, the rotation mechanism and the angle control mechanism and issues movement commands to each actuator, wherein the workpiece is configured to perform work in accordance with the movement command from the control unit so that the distance between the attachment position of the workpiece that performs work and the work position where work is performed by the workpiece becomes a specified value, and at least one of the rotation mechanism and the angle control mechanism is mounted on the linear motion mechanism so that the relative positions of the rotation mechanism and the angle control mechanism can be changed while maintaining the angle between the rotation axis of the rotation mechanism and the base end central axis of the angle control mechanism.

[0009] With this configuration, the one degree of freedom of the linear motion mechanism can be compensated for by the relative positional relationship between the rotation mechanism and the angle control mechanism. Therefore, even with a two-degree-of-freedom linear motion mechanism, the workpiece can be operated from multiple directions, allowing the width and depth dimensions of the work device to be significantly more compact than conventional structures. By reducing the one degree of freedom of the linear motion mechanism, the number of parts can be reduced compared to conventional structures, simplifying the structure and reducing manufacturing costs. However, reducing one degree of freedom of the linear motion mechanism increases restrictions on the teaching work to operate at the desired position, which may make the teaching work difficult without a certain level of specialized knowledge. However, because the work device of the present invention has a control unit, the control unit can automatically perform complex coordinate transformations, allowing operators to easily perform teaching work even without specialized knowledge.

[0010] In the rotation mechanism, a virtual plane formed on an extension of the rotation axis when the rotation axis moves, or the rotation axis when the rotation axis does not move, and a virtual plane formed on an extension of the rotation axis when the base-side central axis moves, or the base-side central axis when the base-side central axis does not move, in the angle control mechanism, may be parallel or coplanar. By arranging the rotation axis movement plane or rotation axis of the rotation mechanism and the base-side central axis movement plane or base-side central axis of the angle control mechanism parallel, the movement direction of the linear motion mechanism and the base-side central axis of the angle control mechanism become parallel, facilitating teaching work. Furthermore, if the rotation mechanism and the angle control mechanism move on the same plane, unnecessary space is reduced, making the working device most compact in width and depth.

[0011] The control unit may have a rotation calculation unit that determines a command rotation angle to be sent to the rotation mechanism unit from the work position information and work direction of the workpiece, and a coordinate conversion unit that determines a command position to be sent to the linear actuator and a command angle to be sent to the angle control mechanism unit from the command rotation angle determined by the rotation calculation unit. This configuration makes it possible to easily perform coordinate conversion.

[0012] The angle control mechanism is a link actuation device, and this link actuation device has a tip-side link hub connected to a base-side link hub via three or more link mechanisms so that its posture can be changed, and each of the link mechanisms has base-side and tip-side end link members, one end of which is rotatably connected to the base-side link hub and the tip-side link hub, respectively, and a central link member, both ends of which are rotatably connected to the other ends of the base-side and tip-side end link members, and two or more of the three or more link mechanisms may be provided with the rotation actuator, which is an attitude control actuator that arbitrarily controls the attitude of the tip-side link hub.

[0013] When the angle control mechanism is configured like a typical pan-tilt mechanism, even a small change in the tip's attitude causes the entire rotation mechanism to move significantly, resulting in slow operating speed. When the angle control mechanism is a link actuator, it can move linearly to the desired angle, allowing for high-speed angle control and shorter cycle times than pan-tilt mechanisms. Furthermore, cables can be routed through the internal space of the link actuator, preventing them from twisting even with repeated rotations, making wiring easier to manage.

[0014] The linear motion mechanism may further include other linear motion actuators having movement directions perpendicular to the movement directions of the two-axis linear motion actuators, and the other linear motion actuators may have a stroke that allows fine adjustment of coordinate conversion that converts the coordinates of the workpiece into machine coordinates. With this configuration, the working device can be made compact in the width direction or depth direction, while making it easy to perform the teaching work described above.

[0015] The working body may be a non-contact type that does not come into contact with the workpiece.

[0016] The workpiece may be an appearance inspection device including a camera for inspecting the workpiece. With this configuration, the process of inspecting the workpiece can be automated with a compact configuration.

[0017] Any combination of at least two features disclosed in the claims and / or the specification and / or the drawings is included in the present invention. In particular, any combination of two or more of the claims is included in the present invention.

[0018] The present invention will be more clearly understood from the following description of preferred embodiments with reference to the accompanying drawings. However, the embodiments and drawings are merely for illustration and explanation, and should not be used to define the scope of the present invention, which is defined by the appended claims. In the accompanying drawings, the same reference numerals in multiple drawings indicate the same or corresponding parts.

[0019] 12A or 12B. FIG. 12B is a perspective view of a working device according to a first embodiment of the present invention. FIG. 12C is a block diagram of a control unit of the working device. FIG. 12D is a perspective view of a link actuation device of the working device. FIG. 12E is a partial cross-sectional view taken along line IV-IV in FIG. 5. FIG. 12F is a front view of a simplified model in which two link mechanisms of the link actuation device have been omitted. FIG. 12G is a diagram in which one link mechanism of the link actuation device is represented by a straight line. FIG. 12H is a conceptual view of a work coordinate system of the working device. FIG. 12H is a conceptual view of coordinate transformation of the working device. FIG. 12I is a perspective view of a working device according to a third embodiment of the present invention. FIG. 12I is a perspective view of a working device according to a fourth embodiment of the present invention. FIG. 12I is a perspective view of a working device of a modified version in which the working device has been partially modified. FIG. 12I is a perspective view of a working device according to a fifth embodiment of the present invention. FIG. 12I is a perspective view of a working device according to a modified version in which the working device has been partially modified. FIG. 12I is a perspective view of the pan-tilt mechanism of FIG. 12A or 12B. FIG. 12I is a perspective view of a working device according to a sixth embodiment of the present invention. FIG. 12I is a perspective view of a working device according to a seventh embodiment of the present invention. FIG. 12I is a perspective view of a working device according to an eighth embodiment of the present invention. FIG. 12I is a plan view of the working device. FIG. 12I is a perspective view of a working device according to a ninth embodiment of the present invention. FIG. 12I is a plan view of the working device. FIG. 12I is a perspective view of a working device according to a tenth embodiment of the present invention.

[0020] [First Embodiment] A working apparatus according to an embodiment of the present invention will be described with reference to Figures 1 to 8. As shown in Figure 1, the working apparatus 1 includes a linear motion mechanism 60, a rotation mechanism 80, a link actuator 7 which is an angle control mechanism, and a control unit 70 (Figure 2). This working apparatus 1 is used in, for example, medical equipment or industrial equipment.

[0021] <General Structure of Working Device: Two Degrees of Freedom of Linear Motion, Three Degrees of Freedom of Rotation> A linear motion mechanism 60 having two linear motion actuators 61, 62 whose movement directions are perpendicular to each other is installed on a stand or the like (not shown). In this example, a rotation mechanism 80 is attached to one of the linear motion actuators 61, 62, the linear motion actuator 61, which moves back and forth in the X-axis direction. The rotation mechanism 80 has a rotation actuator Ra that rotates a workpiece W, such as a workpiece, about a single rotation axis C1 extending in the Z-axis direction. A link actuation device 7 is attached to the other linear motion actuator 62, which moves back and forth in the Z-axis direction. The link actuation device 7 has a rotation actuator 10 that positions a working body E, which will be described later, at an angle corresponding to the two degrees of freedom of rotation.

[0022] The working apparatus 1 performs work by positioning the working body E attached to the tip member 40 of the link actuation device 7 relative to the workpiece W supported by the rotation mechanism 80. The link actuation device 7, the linear motion mechanism 60, and the rotation mechanism 80 are connected to and synchronously controlled by the control unit 70. As shown in FIG. 8, the working apparatus 1 of FIG. 1 performs work in accordance with movement commands from the control unit 70 so that the distance Lw between the attachment position EP of the working body E performing work and the work position of the workpiece W where work is performed by the working body E becomes a specified value. Performing work so that the distance Lw becomes a specified value means performing work while maintaining an arbitrarily set distance Lw constant. With this configuration, work can be performed without changing the distance between the working body E and the work position of the workpiece W during work.

[0023] <Link Actuator> As shown in Fig. 3, the link actuator 7 includes a parallel link mechanism 9 and an attitude control actuator 10, which is a rotational actuator that actuates the parallel link mechanism 9. <Parallel Link Mechanism> The parallel link mechanism 9 connects a link hub 13 on the tip side to a link hub 12 on the base side via three sets of link mechanisms 14 so that the attitude can be changed. The number of sets of link mechanisms 14 may be four or more. In Fig. 5, only one set of link mechanisms 14 is shown, and the remaining two link mechanisms are omitted.

[0024] Each link mechanism 14 has a base-side end link member 15, a tip-side end link member 16, and a central link member 17, forming a four-bar link mechanism consisting of four revolute pairs. As shown in Figure 3, the base-side and tip-side end link members 15, 16 are generally L-shaped, and one end is rotatably connected to the base-side link hub 12 and the tip-side link hub 13, respectively. As shown in Figure 5, the other ends of the base-side and tip-side end link members 15, 16 are rotatably connected to both ends of the central link member 17, respectively.

[0025] The parallel link mechanism 9 has a structure in which two spherical link mechanisms are combined. The central axes of the revolute pairs between the base-end link hub 12 and the base-end end link member 15, and the revolute pairs between the base-end end link member 15 and the central link member 17, intersect at the base-end spherical link center PA. Similarly, the central axes of the revolute pairs between the tip-end link hub 13 and the tip-end end link member 16, and the revolute pairs between the tip-end end link member 16 and the central link member 17, intersect at the tip-end spherical link center PB.

[0026] The distance from the center of each revolute pair between the base end link hub 12 and each base end end link member 15 to the base end spherical link center PA is the same. The distance from the center of each revolute pair between each base end end link member 15 and each central link member 17 to the base end spherical link center PA is the same. Similarly, the distance from the center of each revolute pair between the tip end link hub 13 and each tip end link member 16 to the tip end spherical link center PB is the same. The distance from the center of each revolute pair between each tip end link member 16 and each central link member 17 to the tip end spherical link center PB is the same.

[0027] The central axes of the revolute pairs between the base-end and tip-end end link members 15, 16 and the central link member 17 may have a certain cross angle γ or may be parallel. The arm angle, which is the angle formed by the central axis of the revolute pairs between the base-end link hub 12 and the base-end end link member 15 and the central axis of the revolute pairs between the base-end end link member 15 and the central link member 17, is set to a predetermined angle.

[0028] The three sets of link mechanisms 14 have geometrically identical shapes. "Geometrically identical shapes" refers to a geometric model, as shown in FIG. 6 , in which each link member 15, 16, 17 is represented by a straight line. That is, a model represented by each rotation pair and the straight lines connecting these rotation pairs has a shape in which the base end portion and the tip end portion are symmetrical with respect to the center of the central link member 17, regardless of the posture of the model. FIG. 6 is a diagram showing one set of link mechanisms 14 represented by straight lines. The parallel link mechanism 9 of this embodiment is a rotationally symmetric type, and the positional relationship between the base end link hub 12 and the base end end link member 15 and the tip end link hub 13 and the tip end end link member 16 is rotationally symmetric with respect to the center line C of the central link member 17. The centers of each central link member 17 are located on a common orbital circle.

[0029] The base-end link hub 12, the tip-end link hub 13, and the three link mechanisms 14 constitute a two-degree-of-freedom mechanism in which the tip-end link hub 13 can rotate freely around two perpendicular axes relative to the base-end link hub 12. In other words, the tip-end link hub 13 can rotate with two degrees of freedom relative to the base-end link hub 12, allowing for free posture change. This two-degree-of-freedom mechanism is compact, yet allows a wide range of movement of the tip-end link hub 13 relative to the base-end link hub 12.

[0030] For example, if the central axes QA and QB of the base-end and tip-end link hubs 12 and 13 are defined as lines passing through the base-end and tip-end spherical link centers PA and PB and intersecting at right angles with the central axes O1 (FIG. 3) of the rotation pairs of the base-end and tip-end link hubs 12 and 13 and the base-end and tip-end end link members 15 and 16, respectively, the maximum bending angle θ between the central axis QA of the base-end link hub 12 (base-end central axis) and the central axis QB of the tip-end link hub 13 is ｍａｘcan be set to approximately 90°. The pivot angle φ of the tip-side link hub 13 relative to the base-side link hub 12 can be set in the range of 0° to 360°. The bending angle θ is the vertical angle at which the central axis QB of the tip-side link hub 13 is inclined relative to the central axis QA of the base-side link hub 12. On the other hand, the pivot angle φ is the horizontal angle at which the central axis QB of the tip-side link hub 13 is inclined relative to the central axis QA of the base-side link hub 12. The maximum bending angle θ ｍａｘ may be 90° or more.

[0031] The position of the distal link hub 13 relative to the proximal link hub 12 is changed around the intersection O of the central axis QA of the proximal link hub 12 and the central axis QB of the distal link hub 13. Figure 3 shows a state in which the central axis QB (Figure 5) of the distal link hub 13 forms a certain operating angle (bend angle) with respect to the central axis QA (Figure 5) of the proximal link hub 12. As shown in Figure 6, even if the position of the distal link hub 13 relative to the proximal link hub 12 changes, the distance L between the proximal and distal spherical link centers PA and PB does not change.

[0032] In this parallel link mechanism 9, when all of the following conditions 1 to 5 are satisfied, due to geometric symmetry, the base-end link hub 12 and base-end end link member 15 move in the same way as the tip-end link hub 13 and tip-end end link member 16. Therefore, when transmitting rotation from the base end to the tip end, the parallel link mechanism 9 functions as a constant velocity universal joint in which the base end and tip end sides rotate at a constant speed with the same rotation angle.

[0033] Condition 1: As shown in Figures 4 and 6, the angles α of the central axes O1, O2 of the rotation pairs of the base-end and tip-end link hubs 12, 13 and the base-end and tip-end end link members 15, 16 in each link mechanism 14, and the lengths from the base-end and tip-end spherical link centers PA, PB are equal to each other.

[0034] Condition 2: The central axes of the rotation pairs between the base end and tip end link hubs 12, 13 of each link mechanism 14 and the base end and tip end link members 15, 16, and the central axes of the rotation pairs between the base end and tip end link members 15, 16 and the central link member 17 intersect with the base end and tip end spherical link centers PA, PB at the base end and tip end.

[0035] Condition 3: The geometric shapes of the base-side end link member 15 and the tip-side end link member 16 are the same. Condition 4: The geometric shapes of the base-side portion and the tip-side portion of the central link member 17 are the same. Condition 5: The angular positional relationship between the central link member 17 and the base-side and tip-side end link members 15, 16 with respect to the plane of symmetry of the central link member 17 is the same on the base-side and tip-side.

[0036] As shown in Figure 3, the base-side link hub 12 has a flat base member 6 and three rotary shaft connecting members 21 that are integral with the base member 6. The base member 6 has a circular through-hole 6a in its central portion, and three rotary shaft connecting members 21 are arranged around the through-hole 6a at equal intervals in the circumferential direction. The center of the through-hole 6a is located on the central axis QA of the base-side link hub 12, as shown in Figure 5. Each rotary shaft connecting member 21 is rotatably connected to a rotary shaft 22, as shown in Figure 4, whose axis intersects with the central axis QA of the base-side link hub 12. One end of the base-side end link member 15 is connected to this rotary shaft 22.

[0037] As shown in Figure 3, the tip-side link hub 13 has a flat tip member 40 and three rotary shaft connecting members 41 arranged at equal intervals in the circumferential direction on the bottom surface of the tip member 40. The center of the circumference on which each rotary shaft connecting member 41 is arranged is located on the central axis QB (Figure 5) of the tip-side link hub 13. A rotary shaft 43 whose axis intersects with the central axis QB (Figure 5) of the tip-side link hub 13 is rotatably connected to each rotary shaft connecting member 41. One end of the tip-side end link member 16 is connected to this rotary shaft 43. The other end of the tip-side end link member 16 is connected to a rotary shaft 45 that is rotatably connected to the other end of the central link member 17.

[0038] <Attitude Control Actuator> The attitude control actuator 10 is a rotary actuator equipped with a speed reduction mechanism 52, and is installed coaxially with the rotation shaft 22 (FIG. 4) on one plane of the base end member 6 of the base end side link hub 12. The attitude control actuator 10 and the speed reduction mechanism 52 are provided integrally, and the speed reduction mechanism 52 is fixed to the base end member 6 by a motor fixing member 53. Note that the attitude control actuator 10 may be equipped with a brake.

[0039] In this example, all three link mechanisms 14 are provided with attitude control actuators 10, but if attitude control actuators 10 are provided in at least two of the three link mechanisms 14, the attitude of the distal link hub 13 relative to the proximal link hub 12 can be determined. The three attitude control actuators 10 are arranged so that their rotation axes 22 (FIG. 4) are perpendicular to the central axis QA (FIG. 5) of the proximal link hub 12, and the central position, which is the intersection of the rotation axes 22 (FIG. 4) of these attitude control actuators 10, is on the central axis QA (FIG. 5) of the proximal link hub 12.

[0040] The link actuation device 7 rotates and drives each attitude control actuator 10, thereby actuating the parallel link mechanism 9. More specifically, when an attitude control actuator 10 is rotated, the rotation is reduced in speed via a reduction mechanism 52 and transmitted to the rotation shaft 22 (FIG. 4). This changes the angle of the base-end end link member 15 relative to the base-end link hub 12, and the attitude of the tip-end link hub 13 relative to the base-end link hub 12 can be changed as desired.

[0041] <Working Body> A working body E is attached to the tip member 40 of the tip-side link hub 13, and the tip portion of the working body E serves as the point of application. Examples of the working body E include a hand including a gripper, a cleaning nozzle, a dispenser, a welding torch, and an image processing device Eg (FIG. 18) including a camera, which will be described later. That is, the working body E can be of a contact type that comes into contact with the workpiece W, or a non-contact type that does not. When the working body E is of the contact type, work is performed by bringing the point of application of the working body E into contact with the workpiece W, and when the working body E is of the non-contact type, work is performed without bringing the point of application of the working body E into contact with the workpiece W.

[0042] <Linear Motion Mechanism> As shown in Figure 1, the linear motion mechanism 60 employs an XZ stage that moves forward and backward in two orthogonal axis directions. The linear motion mechanism 60 has first and second linear motion actuators 61, 62 for driving movement. The first linear motion actuator 61 moves forward and backward in the X-axis direction, which is the width direction. The second linear motion actuator 62 moves forward and backward in the Z-axis direction, which is the up-down direction perpendicular to the X-axis direction. The Y-axis direction is perpendicular to both the X-axis direction and the Z-axis direction.

[0043] The first and second linear actuators 61, 62 are driven by motors 61a, 62a, respectively, and each includes a conversion mechanism (not shown), such as a ball screw, that converts the rotation of the motors 61a, 62a into linear reciprocating motion. Each linear actuator 61, 62 has a guide 61b, 62b extending along the corresponding axial direction and moves along the guide 61b, 62b. Each linear actuator 61, 62 includes a slide table 61c, 62c, and a motor 61a, 62a. In this example, a rotation mechanism 80 is attached to the slide table 61c, which serves as the output section of the first linear actuator 61. A base-side link hub 12 of the link actuator 7 is attached to the slide table 62c, which serves as the output section of the second linear actuator 62. The base-side link hub 12 is installed on the second linear actuator 62 so that the central axis QA (base-side central axis in FIG. 3 ) of the link actuator 7 extends in the X-axis direction.

[0044] <Rotation Mechanism, etc.> The rotation mechanism 80 has an actuator body of the rotation actuator Ra fixed to the slide table 61c, and a rotary table 80a that rotates around a rotation axis C1 in the Z-axis direction above the actuator body. A workpiece W is supported on the upper surface of the rotary table 80a.

[0045] In particular, the working device 1 of this embodiment has both the rotation mechanism 80 and the angle control mechanism 7 mounted on the linear motion mechanism 60 so that the relative positions of the rotation mechanism 80 and the angle control mechanism 7 can be changed while maintaining a constant angle between the rotation axis C1 of the rotation mechanism 80 and the central axis QA ( FIG. 3 ), which is the central axis of the base end of the link actuation device 7. Furthermore, in the rotation mechanism 80, the plane in which the rotation axis C1 moves and the plane in which the central axis QA, which is the central axis of the base end of the link actuation device 7, move are parallel to or on the same plane.

[0046] <Control Unit> The control unit 70 determines the positions and angles of the linear motion mechanism 60, the rotation mechanism 80, and the link actuation device 7, which is an angle control mechanism, and issues movement commands to the actuators 61, 62, Ra, and 10. As shown in FIG. 2, the control unit 70 has a rotation calculation unit 70a and a coordinate conversion unit 70b. As shown in FIGS. 1 and 2, the rotation calculation unit 70a determines a command rotation angle to be sent to the rotation mechanism 80 based on information about the work position and work direction of the workpiece W. The coordinate conversion unit 70b determines a command position to be sent to the linear motion actuators 61 and 62 and a command angle to be sent to the link actuation device 7, which is an angle control mechanism, based on the command rotation angle determined by the rotation calculation unit 70a.

[0047] The function of the control unit 70 is to calculate and set the amount of rotation of the rotation mechanism unit 80 based on the teaching data created in work coordinates, i.e., the work position information (represented as Wx, Wy, Wz) of the workpiece W and the five degrees of freedom (Wx, Wy, Wz, θ', φ') of the work direction (represented as θ', φ'), taking into account the device configuration in the rotation calculation unit 70a so that the mechanical unit's attitude can be expressed as five degrees of freedom (two linear degrees of freedom: θ, φ, R).The coordinate conversion unit 70b converts the value including the amount of rotation into machine coordinates.The rotation calculation unit 70a and the coordinate conversion unit 70b may be combined into one unit.The control unit 70 converts the work coordinates into machine coordinates using the above flow and issues movement commands to each of the actuators 61, 62, Ra, and 10.

[0048] <Image of workpiece coordinate system> The control unit 70 determines a reference point (0,0,0) of the workpiece W, as shown in Figure 7. This reference point (0,0,0) can be any position, and in Figure 7 it is the center point of the bottom surface of the cylindrical workpiece. The control unit 70 (Figure 1) teaches the work position (Wx,Wy,Wz) of the workpiece W considered from the reference point, the angle it forms with the Wx-Wy plane, and the work direction (θ',φ') in terms of the angle it forms with Wx when viewed from the Wz direction.

[0049] <Coordinate Transformation Image> As shown in Fig. 8, the control unit 70 (Fig. 1) transforms the work position (Wx, Wy, Wz) and work direction (θ', φ') of the workpiece W, which are specified by the work coordinate teaching data, into the machine coordinate system. The control unit 70 (Fig. 1) performs the transformation into the machine coordinate system so that the distance Lw between the attachment position EP of the workpiece E and the work position of the workpiece W where work is performed by the workpiece E becomes a specified value. This configuration of the control unit 70 (Fig. 1) makes it possible to easily perform coordinate transformation. In other embodiments described later, the control unit 70 (Fig. 1) is omitted.

[0050] <Operation and Effect> According to the working apparatus 1 shown in FIG. 1 described above, both the rotation mechanism 80 and the angle control mechanism 7 are mounted on the linear motion mechanism 60 so that the relative positions of the rotation mechanism 80 and the angle control mechanism 7 can be changed while maintaining a constant angle between the rotation axis C1 of the rotation mechanism 80 and the central axis QA, which is the central axis of the base end of the link actuation device 7. As a result, the one degree of freedom of the linear motion mechanism 60 can be compensated for by the relative positional relationship between the rotation mechanism 80 and the angle control mechanism 7. Therefore, even though the linear motion mechanism 60 has two degrees of freedom, it is possible to work on the working body E from multiple directions of the workpiece W, and the dimensions of the working apparatus 1 in the width direction and depth direction can be made significantly more compact than with conventional structures. By reducing the one degree of freedom of the linear motion mechanism 60, the number of parts can be reduced and the structure can be simplified compared to conventional structures, thereby reducing manufacturing costs.

[0051] However, by reducing one degree of freedom of the linear motion mechanism 60, restrictions are placed on the teaching work to operate at the desired position, and there is a concern that the teaching work may become difficult without a certain level of specialized knowledge. However, because the working device 1 has a control unit 70, complex coordinate transformations can be performed automatically by the control unit 70, and the worker can easily perform the teaching work even if he or she does not have specialized knowledge.

[0052] In the rotation mechanism 80, a virtual plane (referred to as the "rotation axis movement plane") formed on an extension of the rotation axis when the rotation axis C1 moves and a virtual plane (referred to as the "base-side central axis movement plane") formed on an extension of the rotation axis when the central axis QA, which is the base-side central axis of the link actuation device 7, moves are parallel to or coplanar. When the rotation axis movement plane and the base-side central axis movement plane are arranged parallel to or coplanar with each other, the movement direction of the linear motion mechanism 60, i.e., the rotation axis movement plane and the base-side central axis movement plane, are parallel to the base-side central axis QA of the angle control mechanism 7, or at least one of the rotation axis movement plane and the base-side central axis movement plane includes the base-side central axis QA of the angle control mechanism 7, making teaching easier. Furthermore, when the rotation mechanism 80 and the angle control mechanism 7 are configured to move on the same plane, unnecessary space is reduced, and the working device 1 can be made most compact in width and depth directions.

[0053] When the angle control mechanism is the link actuator 7, it can move linearly to the desired angle, allowing for high-speed angle control and shortening the tact time compared to configurations such as pan-tilt mechanisms. In addition, a cable can be passed through the internal space of the link actuator 7, and the cable will not be twisted even when the rotation is repeated, making it easier to manage the wiring.

[0054] <Regarding Other Embodiments> In the following description, parts corresponding to matters previously described in each embodiment are assigned the same reference numerals, and duplicated description will be omitted. When only part of the configuration is described, the other parts of the configuration are the same as those in the previously described embodiment unless otherwise specified. The same configuration produces the same effects. It is possible to combine not only the parts specifically described in each embodiment, but also parts of the embodiments together, provided that there is no particular problem with the combination.

[0055] 9 , the rotation mechanism 80 may be fixed to a mount or the like (not shown), and the link actuation device 7, which is the angle control mechanism, may be moved by two linear actuators 61, 62. In this example, a guide 61b of the linear actuator 61, which moves back and forth in the X-axis direction, is attached to a slide table 62c of the linear actuator 62, which moves back and forth in the Z-axis direction. The link hub 12 on the base end side of the link actuation device 7 is attached to the slide table 61c, which serves as the output part of the linear actuator 61, which moves back and forth in the X-axis direction. In this way, either the rotation mechanism 80 or the angle control mechanism 7 (the angle control mechanism 7 in this example) is mounted on the linear actuation mechanism 60.

[0056] Furthermore, the plane PQ when the base end central axis QA of the link actuator 7 moves and the rotation axis C1 when the rotation axis C1 does not move are on the same plane (the plane PQ includes the rotation axis C1) or are parallel to each other. In Figure 9, the base end central axis movement plane PQ and the rotation axis C1 are on the same plane. Even with this configuration, the dimensions of the working device 1A in the width direction or depth direction can be made significantly more compact than with conventional structures. In Figure 9, the dimension of the working device 1A in the Y-axis direction can be made more compact. Furthermore, manufacturing costs can be reduced compared to conventional structures.

[0057] 10 , the link actuator 7, which is the angle control mechanism, may be fixed, and the rotation mechanism 80 may be moved by two linear actuators 61, 62. In this example, a guide 61b of the linear actuator 61, which moves back and forth in the X-axis direction, is attached to a slide table 62c of the linear actuator 62, which moves back and forth in the Z-axis direction. The actuator body of the rotation mechanism 80 is fixed to the slide table 61c, which serves as the output section of the linear actuator 61, which moves back and forth in the X-axis direction. In this way, either the rotation mechanism 80 or the angle control mechanism 7 (the rotation mechanism 80 in this example) is mounted on the linear mechanism 60.

[0058] Furthermore, in the rotation mechanism 80, the plane PR when the rotation axis C1 moves and the base-side central axis QA when the base-side central axis QA does not move are on the same plane (the plane PR includes the base-side central axis QA) or are parallel to each other. In FIG. 10, the rotation axis movement plane PR and the base-side central axis QA are on the same plane. Even with this configuration, the dimensions of the working device 1B in the width direction or depth direction can be significantly reduced compared to conventional structures. In FIG. 10, the dimension of the working device 1B in the Y-axis direction can be reduced. Furthermore, manufacturing costs can be reduced compared to conventional structures.

[0059] 11A , the axes of the two linear actuators 61, 62 are offset in the Y-axis direction and are not on the same plane, but the rotation axis movement plane PR and the base end side central axis movement plane PQ are on the same plane (coincident). The axes of the two linear actuators 61, 62 are offset by a predetermined length OF in the Y-axis direction depending on, for example, the layout of the work space, peripheral equipment, etc.

[0060] The base-side link hub 12 is mounted on the second linear actuator 62 so that the central axis QA (base-side central axis) of the link actuator 7 is tilted downward in the Z-axis direction by an angle θa as it moves in one direction in the X-axis direction. Specifically, the link actuator 7 is mounted on a slide table 62c of the linear actuator 62, which moves back and forth in the Z-axis direction, by a mounting member 63 having a sloped trapezoidal shape, with the link actuator 7 tilted at an angle θa with respect to the X-axis direction. The tip of the mounting member 63 is provided with an inclined surface that is inclined at a predetermined angle with respect to the XY plane. The base member 6 of the base-side link hub 12 is fixed to this inclined surface with bolts or the like. In this case, the axes of the two linear actuators 61, 62 are offset, which hinders compactness, but the working device 1C can be made more compact than the conventional structure and manufacturing costs can be reduced.

[0061] <Modification: Inclination of Both Axes> As shown in Figure 11B, a working apparatus 1D may be configured in which the central axis QA of the link actuation device 7 is inclined and the rotation axis C1 of the rotation mechanism unit 80 is inclined. The rotation mechanism unit 80 is installed on a slide table 61c of a linear actuator 61 that moves back and forth in the X-axis direction by a mounting member 64, with the rotation mechanism unit 80 inclined at an angle θb with respect to the Z-axis direction. An inclined surface that is inclined at a predetermined angle with respect to the XY plane is provided at the tip of the mounting member 64. The actuator main body is fixed to this inclined surface with bolts or the like.

[0062] [Fifth Embodiment: Pan-Tilt Mechanism] As shown in Figures 12A and 12B, working apparatuses 1E and 1F may be configured to use a pan-tilt mechanism 7A as an angle control mechanism with two rotational degrees of freedom. Figure 12A shows a configuration in which the link actuator 7 in Figure 1 is replaced with a general pan-tilt mechanism 7A as shown in Figure 13, and Figure 12B shows a configuration in which the link actuator 7 in Figure 11A is replaced with the pan-tilt mechanism 7A shown in Figure 13.

[0063] 14 , a working apparatus 1G may be provided with a third linear actuator 65 moving in a direction (in this example, the Y-axis direction) perpendicular to the directions of movement of the linear actuators 61, 62 of the linear motion mechanism 60, thereby providing a total of six degrees of freedom. This linear actuator 65 has a stroke that allows fine adjustment of deviations in coordinate transformation that converts the coordinates of the workpiece W ( FIG. 7 ) into machine coordinates. In this embodiment, the third linear actuator 65 is not taken into account during coordinate transformation, and the third linear actuator 65 is used for fine adjustments by JOG operation.

[0064] This configuration enables intuitive operation with JOG motion during teaching. Furthermore, the three linear actuators 61, 62, and 65 enable fine adjustments to be made to minute deviations in coordinate conversion (workpiece coordinates → machine coordinates) due to assembly errors of the working device 1G, etc. The third linear actuator 65 only needs a stroke sufficient for fine adjustments. Therefore, the stroke of the third linear actuator 65 can be made sufficiently shorter than the axes of the other linear actuators 61 and 62. Specifically, the stroke of the third linear actuator 65 is less than half the stroke of the other linear actuators 61 and 62. This configuration facilitates the aforementioned teaching operation while maintaining a compact configuration for the working device 1G in the width and depth directions.

[0065] [Seventh Embodiment: Six Degrees of Freedom, Addition of Roll Axis] As shown in FIG. 15 , a roll axis Cr may be added to the tip of the link actuator 7, which is the angle control mechanism, to provide a working apparatus 1H with two degrees of freedom in linear motion and four degrees of freedom in rotation, for a total of six degrees of freedom. In this example, a working body E is attached to the tip member 40 of the link hub 13 on the tip side via a rotation actuator 66. The rotation actuator 66 has an actuator main body and a rotating member. The actuator main body is attached to the tip surface of the tip member 40. The rotating member is attached to the tip of this actuator main body so that it can rotate freely around a rotation axis perpendicular to the tip surface. This configuration makes it possible to control rotation of the working direction axis, which cannot be controlled with five degrees of freedom, and enables work similar to that of a conventional six-degrees-of-freedom configuration to be performed with a compact device configuration.

[0066] 16A and 16B , a working apparatus 1J may be configured in which the central axis QA (base end central axis) of the link actuator 7, which is the angle control mechanism, is offset parallel to the rotation axis movement plane PR. In this case, some teaching restrictions are imposed. For example, there are coordinates where work cannot be performed near the bottom of the angle control mechanism. However, by offsetting the angle control mechanism as described above, it becomes possible to perform desired work with a compact device configuration, depending on the layout of the work space, peripheral equipment, etc.

[0067] 17A and 17B , a working apparatus 1K may be configured in which the central axis QA (base end central axis) of the link actuator 7, which is the angle control mechanism, is not on the same plane as the rotation axis movement plane PR but is freely arranged. In this case, some teaching restrictions are imposed. For example, the range of motion of the angle control mechanism is likely to be restricted. However, by freely arranging the angle control mechanism as described above, it becomes possible to perform desired work with a compact device configuration according to, for example, the layout of the work space, peripheral equipment, etc.

[0068] [Tenth Embodiment: Visual Inspection Apparatus] As shown in FIG. 18 , the workpiece may be an image processing device Eg (non-contact type that does not contact the workpiece W) including a camera Cm, and the work apparatus may be a visual inspection apparatus 1L that inspects the workpiece W. The image processing device Eg includes, for example, a camera Cm that captures an image of the workpiece and a lighting fixture Le that illuminates the workpiece. In the visual inspection apparatus 1L, the camera Cm is electrically connected to a camera control system (not shown) via wiring, and the camera control system performs various controls during image capture. In the case of a non-contact workpiece (image processing device Eg) as described above, work is performed so that the distance Lw2 between the attachment position EP of the workpiece and the work position of the workpiece W where work is performed by the workpiece is a specified value. Performing work so that the distance Lw2 is a specified value means performing work while maintaining a constant distance Lw2 that has been arbitrarily set. This configuration allows work to be performed without changing the distance between the image processing device Eg and the work position of the workpiece W during work. This configuration allows the process of inspecting the workpiece W to be automated with a compact configuration. Furthermore, even if there is no degree of freedom of rotation around the work direction, the inspection object can be judged as long as it is within the field of view of the camera Cm. Therefore, this configuration is suitable for this application, where device space is often limited.

[0069] 9, when one rotation axis C1 when not moving is included in the other imaginary plane PQ formed on an extension line of the rotation axis when the base-side central axis QA moves, the one rotation axis C1 and the other imaginary plane PQ are also included in parallel. In this case, too, the dimensions of the working device 1A in the width direction or depth direction can be made significantly more compact than in the conventional structure.

[0070] As described above, the preferred embodiment has been described with reference to the drawings, but various additions, modifications, and deletions can be made without departing from the spirit of the present invention. Therefore, such additions, modifications, and deletions are also included in the scope of the present invention.

[0071] DESCRIPTION OF SYMBOLS 1 to 1K...Working device 1L...Appearance inspection device 7...Link operating device (angle control mechanism) 7A...Pan / tilt mechanism (angle control mechanism) 10...Attitude control actuator (rotational actuator) 12...Base end link hub 13...Tip end link hub 14...Link mechanism 15...Base end end link member 16...Tip end end link member 17...Central link member 60...Linear motion mechanism 61, 62...Linear motion actuator 65...Linear motion actuator 70...Control unit 70a...Rotation calculation unit 70b...Coordinate conversion unit 80...Rotational mechanism Cm...Camera E...Working body Ra...Rotational actuator W...Worked body

Claims

1. A working device comprising: a linear motion mechanism having two linear actuators with mutually orthogonal movement directions; a rotation mechanism having a rotary actuator that rotates the workpiece around one rotation axis; an angle control mechanism having a rotary actuator that positions the workpiece at an angle with two degrees of freedom of rotation; and a control unit that determines the positions and angles of the linear motion mechanism, the rotation mechanism, and the angle control mechanism and issues movement commands to each actuator, wherein the workpiece is configured to perform work in accordance with the movement command from the control unit so that the distance between the attachment position of the workpiece where work is performed and the work position where work is performed by the workpiece becomes a specified value; and at least one of the rotation mechanism and the angle control mechanism is mounted on the linear motion mechanism so that the relative positions of the rotation mechanism and the angle control mechanism can be changed while maintaining the angle between the rotation axis of the rotation mechanism and the base end central axis of the angle control mechanism.

2. A working device as described in claim 1, wherein the imaginary plane formed on an extension of the rotation axis when the rotation axis moves in the rotation mechanism section, or the rotation axis when the rotation axis does not move, and the imaginary plane formed on an extension of the rotation axis when the base-end central axis moves in the angle control mechanism section, or the base-end central axis when the base-end central axis does not move, are parallel to or on the same plane.

3. A work device according to claim 1 or claim 2, wherein the control unit has a rotation calculation unit that determines a command rotation angle to be sent to the rotation mechanism unit from the work position information and work direction of the work object, and a coordinate conversion unit that determines a command position to be sent to the linear actuator and a command angle to be sent to the angle control mechanism unit from the command rotation angle determined by the rotation calculation unit.

4. In the working device of claim 1 or 2, the angle control mechanism is a link actuation device, and in this link actuation device, a tip-side link hub is connected to a base-side link hub via three or more link mechanisms so that its posture can be changed, and each of the link mechanisms has base-side and tip-side end link members, one end of which is rotatably connected to the base-side link hub and the tip-side link hub, respectively, and a central link member, both ends of which are rotatably connected to the other ends of the base-side and tip-side end link members, and the working device is equipped with the rotary actuator, which is an attitude control actuator that arbitrarily controls the attitude of the tip-side link hub, in two or more of the three or more link mechanisms.

5. A working device according to claim 1 or claim 2, further comprising other linear actuators with movement directions perpendicular to the movement directions of the two-axis linear actuators of the linear motion mechanism, the other linear actuators having a stroke that allows fine adjustment of the coordinate transformation that converts the coordinates of the workpiece into machine coordinates.

6. A working device according to claim 1 or 2, wherein the working body is a non-contact type that does not come into contact with the workpiece.

7. A work device according to claim 6, wherein the work body includes a camera and is an appearance inspection device for inspecting the workpiece.

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