End effector

Abstract

To provide an end effector that detects an inclination of a work-piece while suppressing influence of deformation of the work-piece caused by application of pressure.SOLUTION: An end effector (1) comprises a base member (2), a processing element (3), a pressurizing member (5) that pressurizes a work-piece, and an angle detecting mechanism (11) that detects an inclination angle of a surface of the work-piece. The angle detecting mechanism (11) has: a contact probe (12) that contacts the surface of the work-piece; a support structure (13) that supports the contact probe (12) so that an angle thereof can be changed with respect to the base member (2) and supports the probe so that the probe can move back and forth in a predetermined direction (D) with respect to the pressurizing member (5); and an angle detection sensor (14) that detects an inclination angle of the contact probe (12) with respect to the predetermined direction (D). A contact part (12a) of the contact probe (12) protrudes in a drill-tip direction (D1) which is a direction in which the part gets away from the base member (2), of a drill-shaft direction (D) that is the predetermined direction, with respect to the pressurizing member (5).SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to an end effector that is mounted on a robot or a processing machine and processes a workpiece. [Background technology]

[0002] One example of an end effector is the robot drilling unit described in Patent Document 1. Specifically, Patent Document 1 discloses a drilling unit that includes a cylinder that rotatably supports a drill, a pressure foot that is fixed to the underside of the cylinder and presses down on the workpiece, and an angle detection mechanism that detects the angle between the cylinder and the workpiece.

[0003] The pressure foot has a nosepiece, which is a cylindrical member that surrounds the drill, and a compliance device that supports the nosepiece. The compliance device is made of an elastic material.

[0004] The angle detection mechanism has three sensing probes that come into contact with the workpiece and three displacement detection sensors that individually detect the displacement of the sensing probes. Each sensing probe is located outside the nosepiece. The height of the bottom end of each sensing probe is the same as the height of the bottom end of the nosepiece.

[0005] In the drilling unit described above, when detecting the tilt angle of the workpiece surface relative to the drill axis, the pressure foot nosepiece and three sensing probes are simultaneously pressed against the workpiece surface. In this state, the tilt angle of the workpiece surface is detected by detecting the displacement of the three sensing probes with three displacement detection sensors. Based on the detected tilt angle, the drilling unit's angle is adjusted by the robot arm so that the drill axis coincides with the normal to the workpiece surface. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Publication number 6-45286 Summary of the Invention [Problem to be solved by the invention]

[0007] In the drilling unit of Patent Document 1, the lower end positions of the three sensing probes coincide with the lower end position of the nosepiece, and when detecting the angle, the nosepiece and the three sensing probes are pressed against the surface of the workpiece simultaneously.

[0008] With this structure, if the workpiece surface is inclined relative to the drill axis, the angle of the drilling unit is corrected with the nosepiece pressed against the workpiece at an angle. At this time, a large load is continuously applied from the drilling unit to the workpiece in order to maintain the nosepiece and three sensing probes pressed against the workpiece.

[0009] This is not a problem if the workpiece has a relatively high rigidity, but if the workpiece is thin and has low rigidity, there is a concern that the workpiece may be deformed if the drilling angle is corrected while the drilling unit is pressed against the workpiece.If the workpiece is deformed by applying pressure, additional work will be required, such as correction to return the workpiece to its original shape and re-performing the angle detection operation after the correction.

[0010] The present disclosure has been made in consideration of the above circumstances, and aims to provide an end effector that detects the inclination of a workpiece while suppressing the influence of deformation of the workpiece due to pressure. [Means for solving the problem]

[0011] In order to solve the above problem, an end effector according to one aspect of the present disclosure is an end effector mounted on a robot or processing machine for processing a workpiece, and comprises: a base member attached to the robot or processing machine; a processing element for processing the workpiece; a pressure member supported on the base member and applying pressure to the workpiece when processing by the processing element; and an angle detection mechanism for detecting the inclination angle of the surface of the workpiece with respect to a predetermined direction with respect to the base member, wherein the angle detection mechanism is a contact probe having a contact portion that comes into contact with the surface of the workpiece, the contact portion protruding from the pressure member in a direction away from the base member within the predetermined direction; a support structure that supports the contact probe so that its angle can be changed with respect to the base member and so that it can move forward and backward in the predetermined direction with respect to the pressure member; and an angle detection sensor that detects the inclination angle of the contact probe with respect to the predetermined direction. [Effects of the Invention]

[0012] According to the present disclosure, it is possible to provide an end effector that detects the inclination of a workpiece while suppressing the influence of deformation of the workpiece due to pressure. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a right side view illustrating an overall configuration of an end effector attached to a robot arm according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a perspective view of a main part of the end effector of FIG. 1. [Figure 3] FIG. 3 is a front view of the end effector of FIG. 2. [Figure 4] FIG. 3 is a right side view of the end effector of FIG. 2. [Figure 5] FIG. 3 is a bottom view of the end effector of FIG. 2. [Figure 6] 3 is a perspective view of the end effector of FIG. 2 with the drill and the drive unit removed, viewed from diagonally above left. FIG. [Figure 7]3 is a perspective view of the end effector of FIG. 2 with the drill and the drive unit removed, viewed from diagonally below right. FIG. [Figure 8] 3 is an explanatory cross-sectional view showing the contact probe of FIG. 2 stopped at a position concentric with the pressure foot when the contact probe is not in contact with the workpiece. FIG. [Figure 9] 3 is an explanatory cross-sectional view showing that the contact probe in FIG. 2 comes into contact with the inclined workpiece surface, causing the contact probe to come into contact with the underside of the pressure foot at an inclined position relative to the pressure foot. FIG. [Figure 10] 3 is a side view showing that the contact probe in FIG. 2 comes into contact with an inclined workpiece, causing the contact probe to come into contact with the underside of the pressure foot at an inclined position relative to the pressure foot. FIG. [Figure 11] FIG. 3 is a perspective view of the pressure foot of FIG. 2. [Figure 12] FIG. 3 is a vertical cross-sectional view of the pressure foot of FIG. 2. [Figure 13] FIG. 3 is a perspective view of the contact probe of FIG. 2. [Figure 14] FIG. 10 is a perspective view of a cylindrical pressure foot having a plurality of slits formed on the side surface, as a modified example of the end effector of the present disclosure. [Figure 15] FIG. 10 is a perspective view of a pressure foot having multiple cylinders as a modified example of the end effector of the present disclosure. [Figure 16] FIG. 10 is a perspective view of a modified contact probe as a modified end effector of the present disclosure, the contact probe having a cylindrical base with multiple slits formed on the side surface. [Figure 17] FIG. 10 is a perspective view of a contact probe having a base including multiple cylinders, as a variation of the end effector of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0014] A preferred embodiment of the end effector of the present disclosure will be described in detail below with reference to the drawings. As shown in Fig. 1, the end effector 1 of the present disclosure is attached to a robot arm RA or a processing machine to process a workpiece W. The robot arm RA movably supports the end effector 1 so that the end effector 1 can approach any processing position on the workpiece W. The robot arm RA can be of any type as long as it has the above-mentioned functions, but an articulated robot, for example, is preferred.

[0015] 1 is attached to a robot arm RA of an articulated robot. The robot arm RA has a flange surface FS at its tip for attaching the end effector 1.

[0016] 2 to 7 show the main configuration of the end effector 1. The end effector 1 includes a base member 2, a drill 3 as a processing element for machining the workpiece W, a pressure foot 5 as a pressure member for applying pressure to the workpiece W, a pressing mechanism 6, and an angle detection mechanism 11. The pressure foot 5 applies pressure to the workpiece W by the pressing force from the pressing mechanism 6.

[0017] The angle detection mechanism 11 detects the inclination angle of the surface W1 of the workpiece W with respect to the drill axis direction D, with the base member 2 as a reference. That is, in this embodiment, the predetermined direction is the drill axis direction D, which is the axial direction of the drill 3. Note that the predetermined direction is not limited to the drill axis direction D, and may be any direction with the base member 2 as a reference.

[0018] In this embodiment, the drill 3 is illustrated as an example of a processing element of the present disclosure, but the processing element of the present disclosure is not limited to this. The processing element of the present disclosure may be any element that can process the workpiece W, and in addition to the drill 3, tools for friction spot joining (FSJ) and the like are also included in the processing elements of the present disclosure.

[0019] The end effector 1 further includes a drill rotation motor 7 and an advance / retract motor 4. The drill rotation motor 7 rotates the drill 3. The advance / retract motor 4 advances and retracts the drill 3 and the drill rotation motor 7 in a drill tip direction D1, which is the front side of the drill axial direction D, and in a drill base direction D2, which is the rear side. The advance / retract direction of the drill 3 driven by the advance / retract motor 4 coincides with the drill axial direction D. When the tip of the drill 3 is facing directly downward, the drill axial direction D coincides with the up-and-down direction Z.

[0020] The base member 2 is attached to the flange surface FS of the robot arm RA. The base member 2 has a robot arm connecting portion 2a and a support portion 2b. The robot arm connecting portion 2a is fixed to the flange surface FS of the robot arm RA with bolts or the like. The support portion 2b supports the pressing mechanism 6 and the angle detection mechanism 11.

[0021] The pressure foot 5 is supported by the base member 2 via a pressing mechanism 6. The pressure foot 5 is a pressing member that applies pressure to the workpiece W by the pressing force received from the pressing mechanism 6 during machining by the drill 3.

[0022] As shown in Figs. 1 to 7, the pressure foot 5 is a cylindrical member extending in the drill axial direction D. The pressure foot 5 of this embodiment has a cylindrical shape extending in the drill axial direction D. The pressure foot 5 is disposed in a position concentric with the drill 3. An upper portion of the pressure foot 5 is fixed to a support plate 33 of the pressing mechanism 6, which will be described later.

[0023] 8-9 and 11-12, the pressure foot 5 of this embodiment has a spherical lower surface 5a and an inner surface 5b. The lower surface 5a is the end surface of the pressure foot 5 that protrudes downward in Fig. 8, i.e., in the drill tip direction D1. The inner surface 5b is inclined such that the inner diameter increases downward in Fig. 8, i.e., toward the drill tip direction D1.

[0024] 1 to 7, the pressing mechanism 6 has two air cylinders 31 each having a shaft 31a, two load cells 32 for measuring the pressing force, a support plate 33 for supporting the pressure foot 5, and two air clampers 34. The two air cylinders 31, the two load cells 32, and the two air clampers 34 are arranged on both sides of the drill 3 at a distance from each other.

[0025] 8, a circular through-hole 33a is formed in the support plate 33. A cylindrical pressure foot 5 is fitted into the through-hole 33a. The drill 3 moves through the inside of the pressure foot 5 to the surface of the workpiece W.

[0026] As shown in Figure 7, each of the two air cylinders 31 has a shaft 31a that can move back and forth in the drill axial direction D. Each shaft 31a is connected to a support plate 33 via a load cell 32. As the shaft 31a advances in the drill tip direction D1, the air cylinder 31 presses the pressure foot 5 in the drill tip direction D1 via the support plate 33. The air clamper 34 fixes, or clamps, the shaft 31a being pressed at its current position.

[0027] (Specific configuration of angle detection mechanism 11) 1 to 4, the angle detection mechanism 11 has a contact probe 12, a support structure 13 that supports the contact probe 12, and four displacement sensor main parts 14 that constitute the angle detection sensor. Strictly speaking, the displacement sensor of this embodiment is composed of the displacement sensor main parts 14 and a rod-shaped member 22. Hereinafter, the displacement sensor main parts 14 may be referred to as displacement sensors 14.

[0028] <Contact Probe 12> 8 to 10 and 13, the contact probe 12 has a contact portion 12a that comes into contact with the surface W1 of the workpiece W, and a cylindrical base portion 12b. In this embodiment, the base portion 12b is disposed inside the cylindrical pressure foot 5.

[0029] The contact portion 12a in this embodiment has a plate shape. That is, the contact portion 12a includes a plate-shaped contact plate. Specifically, the contact portion 12a has a disk shape with a hole.

[0030] The contact portion 12a protrudes relative to the pressure foot 5 in a drill tip direction D1, which is a direction away from the support portion 2b of the base member 2 in the drill axial direction D. In other words, the contact portion 12a protrudes relative to the pressure foot 5 on the side closer to the workpiece W when machining the workpiece W.

[0031] Specifically, the contact portion 12a is provided at the end of the base portion 12b in the drill tip direction D1.

[0032] The contact portion 12a protrudes in a direction away from the axis C2 of the cylindrical base portion 12b, in other words, the contact portion 12a protrudes in a direction facing radially outward from the base portion 12b.

[0033] 1 to 10, the contact portion 12a protrudes outward from the outer peripheral surface of the pressure foot 5. As a result, the pressure foot 5 is disposed within a range overlapping the contact portion 12a when viewed from the drill axial direction D.

[0034] 8-9 and 13, the contact portion 12a has an upper surface 12a1. The upper surface 12a1 faces the pressure foot 5 and has a spherical surface that is concave downward in FIG. 8, i.e., in the drill tip direction D1. The spherical upper surface 12a1 faces the spherical lower surface 5a of the pressure foot 5 shown in FIGS. 11-12.

[0035] When the workpiece W is machined, the lower surface 5a of the pressure foot 5 is pressed against the upper surface 12a1 of the contact portion 12a, whereby the pressure foot 5 presses the workpiece W with a predetermined pressing force via the contact portion 12a.

[0036] Furthermore, the lower surface 12a2 of the contact portion 12a is basically configured as a flat surface, but may have at least one groove 12a3 formed therein. In Fig. 5, four grooves 12a3 are arranged at 90 degree intervals from each other.

[0037] The base portion 12b in this embodiment has a cylindrical shape, but a cylindrical shape allows the drill 3 to pass through. The cylindrical shape also includes, for example, a cylindrical shape with a rectangular cross section.

[0038] 8, when the pressure foot 5 is not applying pressure to the workpiece W, the base 12b extends in the drill axial direction D and is arranged concentrically with the drill 3 and the pressure foot 5. Here, C1 shown in FIGS. 8 and 9 is the axial center of the pressure foot 5 and the drill 3, and C2 is the axial center of the base 12b.

[0039] As shown in Figure 9, when the contact portion 12a of the contact probe 12 abuts against the inclined work surface W1, the axis C2 of the base 12b rotates relative to the axis C1 of the pressure foot 5 so as to face in the normal direction of the work surface W1, with the center of rotation O as the center of rotation.

[0040] As shown in FIG. 8, the pressure foot 5 and the base 12b have a difference S between the inner diameter of the pressure foot 5 and the outer diameter of the base 12b that gradually increases in the drill tip direction D1.

[0041] In this embodiment, to achieve a structure in which the difference S increases, the base 12b has a cylindrical shape with a constant outer diameter, and the inner surface 5b of the pressure foot 5 has a tapered shape in which the inner diameter increases toward the drill tip direction D1. Note that the outer surface of the base 12b may have a shape in which the outer diameter decreases toward the drill tip direction D1, i.e., an inverse tapered shape, and the inner surface 5b of the pressure foot 5 may have a cylindrical shape with a constant inner diameter. Alternatively, as a combination of the above two shapes, the inner surface 5b of the pressure foot 5 may have a tapered shape and the outer surface of the base 12b may have an inverse tapered shape.

[0042] <Support structure 13> 1 to 9, the support structure 13 is configured to support the contact probe 12 so that its angle can be changed relative to the base member 2 and so that it can move forward and backward in the drill axial direction D relative to the pressure foot 5. Specifically, the support structure 13 has a support body 21, four rod-shaped members 22, four pressure springs that are biasing members that press each rod-shaped member 22 in the drill tip direction D1, and six attitude maintaining springs 24 that maintain the attitude of the base 12b of the contact probe 12. In this embodiment, the pressure springs that press each rod-shaped member 22 in the drill tip direction D1 are built into the displacement sensor main part 14. It is sufficient that the support structure 13 has three or more rod-shaped members 22.

[0043] The support 21 has a ring-shaped central portion 21a and four arm portions 21b. The arm portions 21b extend radially, i.e., in an X-shape, spaced apart from one another, from the outer circumferential surface of the central portion 21a. A cylindrical base portion 12b of the contact probe 12 is fitted into the central portion 21a. The tip portion 21b1 of each arm portion 21b is disc-shaped. However, the shape of the tip portion 21b1 is not limited to a disc shape.

[0044] The four rod-shaped members 22 extend along the drill axial direction D and are arranged at positions spaced apart from one another in the circumferential direction of the contact probe 12.

[0045] The rod-shaped member 22 advances and retreats in the drill axis direction D relative to the support portion 2b of the base member 2. More specifically, the displacement sensor main portion 14 is supported by the support portion 2b of the base member 2, and an intermediate portion 22a of the rod-shaped member 22 is held by the displacement sensor main portion 14 so as to be able to advance and retreat. A lower end portion 22b, which is the end portion of the rod-shaped member 22 in the drill tip direction D1, is constantly abutting against the support portion 21. Therefore, the lower end portion 22b advances and retreats in the drill axis direction D in accordance with the inclination of the support portion 21. The portion of the rod-shaped member 22 opposite the lower end portion 22b with respect to the intermediate portion 22a, i.e., the upper portion of the rod-shaped member 22, is inserted inside the displacement sensor main portion 14. As a result, the amount of advancement and retreat of the rod-shaped member 22 is measured by the displacement sensor main portion 14.

[0046] In this embodiment, the lower end 22b of the rod-shaped member 22 is pressed against the tip end 21b1 of the arm portion 21b of the support body 21 in the direction from the drill axial direction D to the drill tip direction D1, thereby coming into contact with the tip end 21b1. Each rod-shaped member 22 is biased in the drill tip direction D1 by a compression spring built into the displacement sensor main portion 14. The lower end 22b of the rod-shaped member 22 has a hemispherical shape that protrudes in the drill tip direction D1. As a result, the lower end 22b maintains contact with the tip end 21b1 of the arm portion 21b regardless of the angle at which the tip end 21b1 is tilted.

[0047] 8 and 9, when the contact portion 12a of the contact probe 12 comes into contact with the surface W1 of the workpiece W, which is inclined with respect to the axis C1 of the pressure foot 5, the contact probe 12 and the support body 21 that supports the contact probe 12 are tilted in accordance with the angle of inclination of the surface W1. At this time, the rod-shaped members 22 pressed against the tip portions 21b1 of the four arms 21b of the support body 21 shown in FIG. 2 are displaced in the drill axial direction D in accordance with the displacement of each tip portion 21b1 in the drill axial direction D due to the inclination of the support body 21.

[0048] Therefore, the inclination angle of the surface W1 of the workpiece W is converted into the amount of displacement of the four rod-shaped members 22 in the drill axial direction D via the contact probe 12 and the support body 21. For this reason, the inclination angles of the surface W1 in the front-to-back and left-to-right directions relative to the axis C1 of the pressure foot 5 and the drill 3 can be derived from the amount of displacement of the four rod-shaped members 22.

[0049] 2, 8, and 9, the six position maintaining springs 24 are arranged at positions spaced apart from one another in the circumferential direction of the contact probe 12. Each position maintaining spring 24 is attached under tension between the central portion 21a of the support body 21 and the support plate 33 of the pressing mechanism 6. As a result, the six position maintaining springs 24 bias the base 12b of the contact probe 12 fixed to the central portion 21a, as shown in FIG. 8, and hold the base 12b in a position concentric with the pressure foot 5 when the pressure foot 5 is not pressing the workpiece W.

[0050] <Displacement sensor main part 14> The four displacement sensor main parts 14 constitute an angle detection sensor that detects the inclination angle of the contact probe 12 with respect to the drill axial direction D.

[0051] The four displacement sensor main parts 14 are each fixed to the support part 2b of the base member 2. The four displacement sensor main parts 14 measure the amount of advance and retreat of the four rod-shaped members 22 in the drill axis direction D. The combination of the displacement sensor main parts 14 and the rod-shaped members 22 functions as an advance and retreat sensor.

[0052] When the contact probe 12 comes into contact with the workpiece surface W1, the contact probe 12 and the support 21 tilt, causing the four rod-shaped members 22 to displace in the drill axial direction D. The four displacement sensor main parts 14 measure the amount of advance and retreat of each rod-shaped member 22, making it possible to detect the tilt angle of the contact probe 12.

[0053] (Features of this embodiment) The end effector 1 configured as described above is mounted on the tip of a robot arm RA and is capable of detecting the inclination angle of the surface W1 of a workpiece W to be machined, such as drilled.

[0054] The end effector 1 of this embodiment has a cylindrical pressure foot 5 and an angle detection mechanism 11 that detects the inclination of the workpiece surface W1 relative to the end effector 1. The angle detection mechanism 11 can detect the inclination angle of the workpiece surface W1 independently of the pressure foot 5 using a contact probe 12, and can also detect the inclination angle of the workpiece surface W1 near the tip of the pressure foot 5.

[0055] Specifically, the cylindrical contact probe 12 of the angle detection mechanism 11 is connected via a support 21 and four rod-shaped members 22 of the support structure 13 to four displacement sensor main parts 14 that detect the inclination of the contact probe 12 at a position away from the drill 3. The pressure foot 5 and contact probe 12 have cylindrical axes C1 and C2 that coincide with the axis of the drill 3, and are arranged in the order of contact probe 12, then pressure foot 5, from the inside, surrounding the drill 3. Furthermore, the contact portion 12a at the tip of the contact probe 12 protrudes toward the drill tip side D1 beyond the undersurface 5a, which is the tip of the pressure foot 5 in Figure 8. In addition, the contact probe 12 has a disk-shaped contact portion 12a at the end of the cylindrical base 12b on the drill tip side D1. The contact portion 12a and the pressure foot 5 are designed to mesh together when the end effector 1 is pressed against the workpiece W, and the upper surface 12a1 and the lower surface 5a of the contact portion 12a that come into contact with each other are spherical. This allows the contact portion 12a to come into contact with the workpiece surface W1 without coming into partial contact with the pressure foot 5 even when the contact probe 12 is tilted to some extent.

[0056] In the configuration of the end effector 1 described above, the angle detection mechanism 11 has the contact probe 12, the support structure 13, and four displacement sensor main parts 14 constituting the angle detection sensor in order to detect the inclination angle of the work surface W1 relative to the drill axis direction D, which is a predetermined direction based on the base member 2.

[0057] The contact portion 12a of the contact probe 12 protrudes relative to the pressure foot 5 in the drill tip direction D1, which is a direction away from the support portion 2b of the base member 2 in the drill axial direction D. In other words, the contact portion 12a protrudes closer to the workpiece W during machining of the workpiece W. Therefore, when the end effector 1 approaches the workpiece W using the robot arm RA, only the contact portion 12a of the contact probe 12 first contacts the surface W1 of the workpiece W before the pressure foot 5 applies pressure to the workpiece W with a predetermined pressure during machining of the workpiece W. At this time, the four displacement sensor main portions 14 detect the tilt angle of the contact probe 12 with respect to the drill axial direction D, thereby detecting the tilt angle of the surface W1 of the workpiece W with respect to the drill axial direction D, i.e., the inclination of the workpiece W. This makes it possible to detect the inclination of the workpiece W while suppressing the effects of deformation of the workpiece W due to the pressure of the pressure foot 5.

[0058] Based on the detected tilt angle, the end effector 1 can smoothly process the workpiece W as follows: That is, if the tilt of the workpiece W is within the tolerance, the processing operation can begin immediately, or if the tolerance is exceeded, the angle of the entire end effector 1 is corrected by the operation of the robot arm RA. After that, the robot arm RA operates the end effector 1 again so that the pressure foot 5 of the end effector 1 contacts the workpiece W, pressing down the workpiece W, and then the processing operation can begin.

[0059] In the configuration of the end effector 1 described above, the pressure foot 5 has a tubular shape extending in the drill axial direction D, specifically a cylindrical shape. The pressure foot 5 is disposed in a position concentric with the drill 3. The contact probe 12 has a tubular base 12b. The base 12b is specifically cylindrical. The contact portion 12a is provided at the end of the base 12b on the drill tip side D1.

[0060] As shown in Figure 8, when the pressure foot 5 is not applying pressure to the workpiece W, the base 12b of the contact probe 12 is arranged concentrically with the drill 3 and the pressure foot 5. As a result, as shown in Figure 9, when the end effector 1 is brought close to the workpiece W and the contact portion 12a of the contact probe 12 comes into contact with the surface W1 of the workpiece W, the contact probe 12 can be tilted with precision so that the angle is the same as the angle of inclination of the portion of the workpiece W that is being machined by the drill 3. Moreover, because pressure can be applied to the workpiece W coaxially with the drill 3 with precision, the angle of the workpiece W relative to the drill 3 can also be detected with precision. This makes it possible to improve the accuracy of angle detection of the workpiece W.

[0061] Furthermore, in the above configuration, the contact probe 12 tilts at the same angle as the inclination angle of the surface W1 of the workpiece W. Therefore, in the above configuration, when the workpiece W has a shape that has three-dimensional curvature, for example, even when the shape of the workpiece W has a cylindrical or spherical surface, it is possible to perform angle detection with high accuracy.

[0062] In the configuration of the end effector 1 described above, the contact portion 12a includes a plate-shaped contact plate. Specifically, the contact plate is disk-shaped. The pressure foot 5 is disposed within a range overlapping the contact portion 12a when viewed from the drill axis direction D.

[0063] As a result, when the end effector 1 presses down on the workpiece W, the tip of the pressure foot 5 comes into contact with the contact plate of the contact portion 12a of the contact probe 12, and the pressing load from the pressure foot 5 is transmitted via the contact plate to the workpiece W. As a result, when the end effector 1 presses down on the workpiece W during machining, even if the workpiece W is tilted, the pressing load from the cylindrical pressure foot 5 can be uniformly distributed around the machining portion of the workpiece W via the plate-shaped contact plate.

[0064] The above-mentioned "during machining of the workpiece W, etc." need only include at least the time when the workpiece W is machined, and may include both the time when the workpiece is machined and the time when the angle is detected. During angle detection, the pressure foot 5 does not need to come into contact with the contact portion 12a, or may come into contact with the contact portion 12a with a load smaller than the load during workpiece machining.

[0065] Furthermore, the above-mentioned disk-shaped contact plate is a disk that extends the same distance from the axis C2 of the base 12b, and can efficiently hold the workpiece W. The projected shape of the contact plate may be changed depending on various conditions such as the purpose of workpiece processing, for example, the purpose of drilling, or the shape of the workpiece.

[0066] In the above-described configuration of the end effector 1, the base 12b is disposed inside the cylindrical pressure foot 5. The contact plate 12a protrudes in a direction away from the axis C2 of the cylindrical base 12b. Therefore, the protrusion width of the contact portion 12a contact plate from the base 12b is greater than when the base 12b of the contact probe 12 is disposed outside the pressure foot 5. This allows the area of ​​the contact plate to be increased, enabling the workpiece W to be stably pressed down by the contact plate.

[0067] It should be noted that even in a configuration in which the base portion 12b is disposed outside the pressure foot 5, the above-described angle detection operation can be performed.

[0068] In the above-described configuration of the end effector 1, the upper surface 12a1 of the contact plate that faces the pressure foot 5 has a concave spherical surface. Therefore, even if the pressure foot 5 is tilted relative to the contact probe 12, the entire circumference of the tip of the pressure foot 5 can come into contact with the contact plate of the contact portion 12a. This ensures a wide contact area between the pressure foot 5 and the contact plate, making it possible to transmit the pressing load from the pressure foot 5 to the contact plate while distributing it evenly.

[0069] Furthermore, since the lower surface 5a, which is the tip of the pressure foot 5, is a convex spherical surface, a wide contact area with the upper surface 12a1 can be ensured.

[0070] In the above-described configuration of the end effector 1, as shown in FIG. 8, the pressure foot 5 and the base 12b are cylindrical. The base 12b is disposed inside the pressure foot 5. The difference S between the inner diameter of the pressure foot 5 and the outer diameter of the base 12b gradually increases toward the tip direction D1 of the drill 3. With this configuration, even if the pressure foot 5 has a small outer diameter, interference between the pressure foot 5 and the base 12b of the contact probe 12 can be prevented when the contact probe 12 tilts in accordance with the tilt of the workpiece W. This makes it possible to miniaturize the tip portion, including the pressure foot 5, of the end effector 1.

[0071] In the configuration of the end effector 1 described above, the support structure 13 supporting the contact probe 12 includes an attitude-maintaining spring 24 that biases the base 12b to maintain the base 12b in a position concentric with the pressure foot 5 when the pressure foot 5 is not applying pressure to the workpiece W.

[0072] In this configuration, the holding force applied to the base 12b of the contact probe 12 from the posture holding spring 24 of the support structure 13 makes it possible to hold the base 12b of the contact probe 12 in a position concentric with the pressure foot 5 when the pressure foot 5 is not applying pressure to the workpiece W. This makes it possible to prevent the contact probe 12 from wobbling before it comes into contact with the workpiece W.

[0073] In the configuration of the end effector 1 described above, the support structure 13 includes a support 21 that supports the contact probe 12, and three or more, for example four, rod-shaped members 22 that are arranged at positions spaced apart from one another in the circumferential direction of the contact probe 12 and extend in the drill axial direction D. An intermediate portion 22a of each of the three or more rod-shaped members 22 is supported on the base member 2 so as to be able to advance and retreat in the drill axial direction D, and a lower end portion 22b abuts against the support 21 so as to advance and retreat in the drill axial direction D in accordance with the inclination of the support 21.

[0074] The four displacement sensor main parts 14 that make up the angle detection sensor are each fixed to the base member 2. The four displacement sensor main parts 14 are advance / retract sensors that measure the amount of advance / retraction of the four rod-shaped members 22 in the drill axis direction D. The four displacement sensor main parts 14 detect the tilt angle of the contact probe 12 from the amount of advance / retraction of the four rod-shaped members 22.

[0075] In this configuration, the support structure 13 has a simple structure comprising four rod-shaped members 22 and is able to support the contact probe 12 so that the angle can be changed and so that the contact probe 12 can be advanced and retreated in the drill axial direction D. The four displacement sensor main parts 14 that make up the angle detection sensor have a simple structure comprising three or more advance and retreat sensors, and it becomes possible to detect the tilt angle of the contact probe 12 from the amount of advance and retreat of the four rod-shaped members 22.

[0076] It should be noted that the above-described effects can be achieved if there are three or more rod-shaped members 22 and displacement sensor main parts 14, which are advance / retract sensors that measure the amount of advance / retraction.

[0077] Furthermore, with the above configuration, when machining a workpiece, a transition is made from a state in which only the contact probe 12 is in contact with the workpiece surface W1, i.e., a soft-touch state, to a state in which the workpiece W is being held down by the pressure foot 5. During the transition from this soft-touch state to the state in which the workpiece W is being held down, the four displacement sensor main parts 14 can continuously confirm that the end effector 1 is approaching the workpiece W perpendicularly.

[0078] In the configuration of the end effector 1 described above, the lower end 22b of the rod-shaped member 22 is pressed against the tip 21b1 of the arm 21b of the support body 21 in the drill axial direction D by the biasing force of a compression spring built into the displacement sensor main part 14. Therefore, before the contact probe 12 comes into contact with the workpiece W, the pressing forces from the three or more rod-shaped members 22 to the support body 21 make it possible to maintain the support body 21 and the contact probe 12 supported thereby in a neutral position.

[0079] In the above embodiment, the lower end 22b of the rod-shaped member 22 is pressed against the tip 21b1 of the arm 21b of the support body 21 to abut against it, but for example, the lower end 22b of the rod-shaped member 22 may be connected to the tip 21b1 of the arm 21b by a ball joint.

[0080] (Variation) Although the pressure foot 5 of the end effector 1 and the side surface of the base 12b of the contact probe 12 in the above embodiment are both closed cylindrical surfaces, the end effector of the present disclosure is not limited to this.

[0081] 14 to 17, at least one of the pressure feet 45, 55 and the bases 42b, 52b of the contact probes 42, 52 may include a cylindrical opening on one side. This configuration allows the weight of the pressure feet 45, 55 and / or the bases 42b, 52b to be reduced while maintaining the accuracy of angle detection of the workpiece surface.

[0082] 14 has a plurality of trapezoidal openings 45a extending upward from the lower end on the side circumferential surface. The openings 45a are arranged at equal intervals around the circumference of the pressure foot 45. This allows the pressure foot 45 to press the workpiece W at the portions between the openings 45a.

[0083] 15 has a plurality of cylinders 55a spaced apart from one another in the circumferential direction of the pressure foot 55. The plurality of cylinders 55a form a cylindrical shape with an opening that opens to the side.

[0084] 16 has a contact portion 42a including a contact plate and a cylindrical base portion 42b. The base portion 42b has a plurality of rectangular openings 42c on its circumferential surface. The openings 42c are arranged at equal intervals around the circumference of the contact probe 42.

[0085] 17 has a contact portion 52a including a contact plate and a base portion 52b. The base portion 52b has a plurality of cylinders 52c spaced apart in the circumferential direction of the contact probe 52, an upper ring-shaped portion 52d connecting the upper ends of the plurality of cylinders 52c, and a lower ring-shaped portion 52e connecting the lower ends of the plurality of cylinders 52c. The plurality of cylinders 52c form a cylindrical shape with an opening on the side.

[0086] 14 and 15 and the contact probes 42 and 52 shown in FIGS. 16 and 17, each having an opening on its side, may be combined so that chips and powder generated during machining of the workpiece W can be discharged to the outside of the pressure feet 45 and 55 through these side openings. Discharge of chips and powder generated during machining of the workpiece W may be performed by a suction mechanism provided in the space between the support portion 21a and the drill 3. Furthermore, the operator can visually check the state of the machining element, such as the drill 3, from outside the pressure feet 45 and 55 through the side opening.

[0087] The displacement sensor in this embodiment is a contact-type sensor composed of the displacement sensor main portion 14 and the rod-shaped member 22, but is not limited to this. For example, the angular displacement of the contact probe 52 may be measured by measuring the displacement in the vertical direction Z of the tip end 21b1 of each arm portion 21b of the support body 21 using a laser displacement meter.

[0088] (summary) The above-described embodiments and their modifications include the following disclosures.

[0089] An end effector according to a first aspect of the present disclosure is an end effector mounted on a robot or processing machine to process a workpiece, and comprises: a base member attached to the robot or processing machine; a processing element that processes the workpiece; a pressure member supported on the base member and that pressurizes the workpiece when processing by the processing element; and an angle detection mechanism that detects the inclination angle of the surface of the workpiece with respect to a predetermined direction with respect to the base member, wherein the angle detection mechanism comprises a contact probe having a contact portion that contacts the surface of the workpiece, the contact portion protruding from the pressure member in a direction away from the base member within the predetermined direction; a support structure that supports the contact probe so that its angle can be changed with respect to the base member and so that it can move forward and backward in the predetermined direction with respect to the pressure member; and an angle detection sensor that detects the inclination angle of the contact probe with respect to the predetermined direction.

[0090] According to a first aspect, the angle detection mechanism has the above-described contact probe, a support structure, and an angle detection sensor to detect the tilt angle of the workpiece surface relative to a predetermined direction with the base member as a reference.

[0091] Because the contact portion of the contact probe protrudes away from the base member relative to the pressure member, when the end effector of a robot or processing machine approaches the workpiece, only the contact portion of the contact probe first comes into contact with the surface of the workpiece before the pressure member applies a predetermined pressure to the workpiece during workpiece processing. At this time, the angle detection sensor detects the tilt angle of the contact probe relative to the predetermined direction, thereby detecting the tilt angle of the workpiece surface relative to the predetermined direction, i.e., the inclination of the workpiece. This makes it possible to detect the inclination of the workpiece while suppressing the effects of workpiece deformation due to pressure from the pressure member.

[0092] In the end effector according to the second aspect of the present disclosure, the pressure applying member is cylindrical and extends in the predetermined direction and is positioned concentrically with the workpiece, the contact probe has a cylindrical base and the contact portion is provided at the end of the base on the tip side of the workpiece, and the base extends in the predetermined direction and is positioned concentrically with the workpiece and the pressure applying member when the pressure applying member is not applying pressure to the workpiece.

[0093] According to the second aspect, when the pressure member is not applying pressure to the workpiece, the base of the contact probe is arranged concentrically with the workpiece element and the pressure member. As a result, when the end effector is brought close to the workpiece and the contact portion of the contact probe comes into contact with the surface of the workpiece, the contact probe can be tilted with precision to match the inclination angle of the portion of the workpiece being machined by the workpiece element. Furthermore, since pressure can be applied to the workpiece coaxially with the workpiece element with precision, the angle of the workpiece relative to the workpiece element can also be detected with precision. This improves the accuracy of workpiece angle detection. Furthermore, with the above configuration, since the contact probe tilts at the same angle as the inclination angle of the workpiece surface, precise angle detection is possible even when the workpiece has a three-dimensional curvature, for example, a workpiece shape having a cylindrical or spherical surface.

[0094] In the end effector according to the third aspect of the present disclosure, at least one of the pressure member and the base portion includes a cylindrical opening that opens laterally.

[0095] According to the third aspect, it is possible to reduce the weight of the pressure member and / or the base of the contact probe while maintaining the accuracy of angle detection.

[0096] In an end effector according to a fourth aspect of the present disclosure, the contact portion includes a plate-shaped contact plate, and the pressure member is disposed within a range overlapping the contact plate when viewed from the predetermined direction.

[0097] According to the fourth aspect, when the end effector presses down on the workpiece, the tip of the pressure member comes into contact with the contact plate of the contact probe, and the pressing load from the pressure member can be transmitted to the workpiece via the contact plate. As a result, when the end effector presses down on the workpiece during machining, even if the workpiece is tilted, the pressing load from the cylindrical pressure member can be uniformly distributed around the machining portion of the workpiece via the plate-shaped contact plate.

[0098] In the end effector according to a fifth aspect of the present disclosure, the base is disposed inside the cylindrical pressing member, and the contact plate protrudes in a direction away from the axis of the cylindrical base.

[0099] According to the fifth aspect, the protruding width of the contact plate from the base is greater than when the base of the contact probe is positioned outside the pressure member, so the area of ​​the contact plate can be increased, and the workpiece can be stably pressed down by the contact plate.

[0100] In the end effector according to a sixth aspect of the present disclosure, the surface of the contact plate facing the pressure member has a concave spherical surface.

[0101] According to the sixth aspect, even when the pressure member is tilted relative to the contact probe, the entire circumference of the tip of the pressure member can contact the contact plate, thereby ensuring a wide contact area between the pressure member and the contact plate and enabling the pressing load to be transmitted from the pressure member to the contact plate while being uniformly distributed.

[0102] In an end effector according to a seventh aspect of the present disclosure, the pressure applying member and the base are cylindrical in shape, the base is disposed inside the pressure applying member, and the difference between the inner diameter of the pressure applying member and the outer diameter of the base gradually increases toward the tip of the workpiece.

[0103] According to the seventh aspect, even if the pressure member has a small outer diameter, it is possible to prevent interference between the pressure member and the base of the contact probe when the contact probe tilts in accordance with the tilt of the workpiece, thereby making it possible to miniaturize the tip of the end effector, including the pressure member.

[0104] In an end effector according to an eighth aspect of the present disclosure, the support structure includes a biasing member that biases the base and holds the base in a position concentric with the pressure member when the pressure member is not pressing against the workpiece.

[0105] According to the eighth aspect, the holding force applied to the base of the contact probe from the biasing member of the support structure makes it possible to hold the base of the contact probe in a position concentric with the pressure member when the pressure member is not pressing the workpiece, thereby preventing the contact probe from wobbling before it comes into contact with the workpiece.

[0106] In an end effector according to a ninth aspect of the present disclosure, the support structure includes a support body that supports the contact probe, and three or more rod-shaped members that are arranged at positions spaced apart circumferentially of the contact probe and extend in the predetermined direction, each of the three or more rod-shaped members being supported on the base member so that they can move back and forth in the predetermined direction, and the ends of the rod-shaped members abut or are connected to the support body so as to move back and forth in the predetermined direction depending on the inclination of the support body, and the angle detection sensor includes three or more advance / retract sensors that are each fixed to the base member and measure the amount of advance / retraction of the three or more rod-shaped members in the predetermined direction, and the inclination angle of the contact probe is detected from the amount of advance / retraction of the three or more rod-shaped members.

[0107] According to the ninth aspect, the support structure has a simple structure including three or more rod-shaped members, and can realize the function of supporting the contact probe so that the angle can be changed and the contact probe can be moved forward and backward in a predetermined direction. Moreover, the angle detection sensor has a simple structure including three or more advance / retract sensors, and can detect the tilt angle of the contact probe from the amount of advance / retraction of the three or more rod-shaped members.

[0108] In the end effector according to a tenth aspect of the present disclosure, the end of the rod-shaped member is pressed against the support body from the predetermined direction and thereby comes into contact with the support body.

[0109] According to the tenth aspect, the ends of the three or more rod-shaped members are pressed against the support from a predetermined direction, thereby abutting against the support. Therefore, before the contact probe comes into contact with the workpiece, the pressing force from the three or more rod-shaped members to the support makes it possible to maintain the support and the contact probe supported by it in a neutral position. [Explanation of symbols]

[0110] 1 End Effector 2 Base material 3 Drill (machining element) 4. Advance / retreat motor 5 Pressure foot (pressure member) 6 Pressing mechanism 7 Drill rotation motor 11 Angle detection mechanism 12 Contact Probes 12a Contact part (contact plate) 13 Support structure 14 Displacement sensor (angle detection sensor) 21 Support 22 Rod-shaped member 24 Posture maintaining spring (biasing member) D Drill axis direction (specified direction) D1 Drill tip direction

Claims

1. An end effector mounted on a robot or a processing machine to process a workpiece, a base member attached to the robot or processing machine; A processing element that processes the workpiece; a pressure member supported by the base member and pressing the workpiece when the workpiece is machined by the machining element; an angle detection mechanism that detects an inclination angle of the surface of the workpiece relative to a predetermined direction using the base member as a reference; The angle detection mechanism a contact probe having a contact portion that comes into contact with a surface of the workpiece, the contact portion protruding from the pressure member in a direction away from the base member in the predetermined direction; a support structure that supports the contact probe so that the angle of the contact probe can be changed relative to the base member and that supports the contact probe so that the contact probe can move forward and backward in the predetermined direction relative to the pressure member; an angle detection sensor that detects an inclination angle of the contact probe relative to the predetermined direction.

2. The end effector of claim 1 , the pressing member has a cylindrical shape extending in the predetermined direction and is disposed at a position concentric with the processing element, The contact probe has a cylindrical base, the contact portion is provided at an end portion of the base portion on a tip side of the processing element, The base portion extends in the predetermined direction and is arranged concentrically with the processing element and the pressure member when the pressure member is not pressing the workpiece.

3. The end effector according to claim 2, At least one of the pressure member and the base includes a cylindrical opening that opens laterally.

4. The end effector according to claim 2, the contact portion includes a plate-shaped contact plate, The pressure member is disposed within a range overlapping the contact plate when viewed from the predetermined direction.

5. The end effector according to claim 4, the base portion is disposed inside the cylindrical pressing member, The contact plate protrudes in a direction away from the axis of the cylindrical base portion. End effector.

6. The end effector according to claim 5, An end effector, wherein a surface of the contact plate facing the pressure member has a concave spherical surface.

7. The end effector according to claim 2, the pressure member and the base are cylindrical; the base is disposed inside the pressure member, The pressure member and the base portion have a difference between an inner diameter of the pressure member and an outer diameter of the base portion that gradually increases toward the tip of the processing element.

8. The end effector according to claim 2, The support structure includes a biasing member that biases the base to hold the base in a position concentric with the pressure member when the pressure member is not pressing the workpiece.

9. The end effector according to any one of claims 1 to 8, the support structure includes a support body that supports the contact probe, and three or more rod-shaped members that are arranged at positions spaced apart from one another in a circumferential direction of the contact probe and extend in the predetermined direction, each of the three or more rod-shaped members is supported on the base member so as to be able to advance and retreat in the predetermined direction, and an end of each of the rod-shaped members is in contact with or connected to the support member so as to advance and retreat in the predetermined direction in accordance with an inclination of the support member; The angle detection sensor includes three or more advance / retract sensors that are each fixed to the base member and measure the amount of advance / retraction of the three or more rod-shaped members in the specified direction, and detects the inclination angle of the contact probe from the amount of advance / retraction of the three or more rod-shaped members.

10. The end effector of claim 9, The end of the rod-shaped member is pressed against the support from the predetermined direction to come into contact with the support.

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