Manipulator

Abstract

To realize a manipulator which makes a reaction force generated during use of a tool part less likely to be transmitted to a force sensor.SOLUTION: A manipulator includes: an arm (4); a force sensor (28) formed at the arm; a holding part (34) which is formed at the arm through the force sensor and holds a workpiece; and a tool part (36) which is formed at the arm through a member different from the force sensor and processes the workpiece held by the holding part.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a manipulator that grips a workpiece by a gripping portion formed on an arm.

Background Art

[0002] Patent Document 1 describes a support device for a component gripping device for gripping a door of an automobile in an automobile manufacturing line.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The support device for the component gripping device described in Patent Document 1 performs position control of the door by a mechanical 6-axis floating unit. As described above, a manipulator that grips a workpiece using a mechanical unit causes an increase in the number and weight of the units. In addition, since the manipulator needs to adjust the force applied to each unit one by one as the posture of the unit changes, the control content of the manipulator becomes complicated. Furthermore, for example, when a removal device such as a nut runner for removing a workpiece from another member is attached to the unit, the unit receives the reaction force generated by the use of the removal device, so the load-bearing capacity of the unit decreases and the position control of the unit becomes difficult.

[0005] Therefore, instead of a mechanical 6-axis floating unit, it is conceivable to install a force sensor on the door gripping member and allow the force or moment applied to the gripping member to be detected by the force sensor, thereby controlling it in accordance with the manipulator itself. However, in this case, the force sensor will receive the reaction force generated when using the aforementioned removal device, and considering the moment resistance force of the force sensor, the load-bearing capacity of the manipulator will decrease. [Means for solving the problem]

[0006] To solve the above problems, a manipulator according to one aspect of the present disclosure comprises an arm, a force sensor formed on the arm, a gripping portion formed on the arm via the force sensor for gripping a first workpiece, and a tool portion formed on the arm via a member different from the force sensor for machining the first workpiece gripped by the gripping portion. [Effects of the Invention]

[0007] According to one aspect of this disclosure, a manipulator is realized that has improved load-bearing capacity while enabling the detection of force or moment applied to the gripping portion by a force sensor. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram showing an enlarged view of the vicinity of the arm tip and the vicinity of the floating unit in a schematic perspective view of a manipulator according to the embodiment of this disclosure. [Figure 2] This is a schematic perspective view of a manipulator according to an embodiment of the present disclosure. [Figure 3] This is a perspective view illustrating the process of gripping a door and removing a door from a vehicle frame using a manipulator according to an embodiment of the present disclosure. [Figure 4] This is a schematic side view of a door gripped by a manipulator according to an embodiment of the present disclosure. [Figure 5]This is a cross-sectional view illustrating the process of controlling the alignment of the gripping pin to the door opening according to an embodiment of the present disclosure. [Modes for carrying out the invention]

[0009] [Embodiment] <Manipulator> Figure 2 is a schematic perspective view showing a manipulator according to this embodiment. As shown in Figure 2, the manipulator 2 according to this embodiment comprises an arm 4, a floating unit 6, a base 8, and a control unit 10.

[0010] Arm 4 is a flexible arm having multiple joints, and is formed at the end opposite the base 8, for moving the floating unit 6 (described in detail later) to various positions and supporting it in various orientations. Arm 4 includes, for example, as shown in Figure 2, a floating arm 12, a first arm 14, and a second arm 16, starting from the tip with the base 8 as the root. Arm 4 further includes a first joint 18, a second joint 20, and a third joint 22.

[0011] The first joint 18 connects the floating arm 12 to the first arm 14, the second joint 20 connects the first arm 14 to the second arm 16, and the third joint 22 connects the second arm 16 to the base 8. In particular, the floating arm 12 may be formed on the first joint 18 via the arm joint 24 shown in Figure 2. Each joint of the arm 4 may be driven by a power unit (not shown), and the position and orientation of the floating unit 6 can be changed by changing the relative angle of each arm connected to each joint.

[0012] The floating unit 6 is formed on the tip side of the arm 4, particularly on the floating arm 12. The various parts of the floating unit 6 will be described in detail later.

[0013] The control unit 10 is located, for example, inside the base 8 on which the arm 4 is formed, and controls the arm 4 and the floating unit 6. In this embodiment, the control unit 10 is not limited to this and may be formed outside the arm 4, the floating unit 6, and the base 8, and may control the arm 4 and the floating unit 6 by communication means (not shown). In this embodiment, for example, the control unit 10 may control the position and orientation of the floating unit 6 by controlling the power unit that drives each joint of the arm 4. The method of controlling the parts of the floating unit 6 by the control unit 10 will be described in detail later.

[0014] <Floating Unit> The floating unit 6 will be described in more detail with reference to Figure 1. Figure 1 is an enlarged view of area A shown in Figure 2, or in other words, a schematic diagram showing an enlarged view of the vicinity of the tip of the arm 4 and the vicinity of the floating unit 6. In Figure 1, schematic diagram A1 shows the various parts of the floating unit 6, while schematic diagram A2 omits the gripping part 34 and the nut runner unit 36, which will be described in detail later, in order to show the various parts of the floating unit 6 in more detail.

[0015] As shown in schematic diagram A2 of Figure 1, the floating unit 6 includes a buffer portion 26, a force sensor 28, a first joint portion 30, and a second joint portion 32. Furthermore, as shown in schematic diagram A1 of Figure 1, the floating unit 6 also includes a gripping portion 34 and a nut runner unit 36 ​​as a tool portion.

[0016] In this embodiment, the description assumes that arm 4 includes floating arm 12, but the embodiment is not limited to this. For example, floating unit 6 may include floating arm 12 as an arm, and may also include arm joint 24. In other words, in this embodiment, each member located on the tip side of arm 4 beyond the arm joint 24 that connects to the first joint 18 may be referred to as floating unit 6.

[0017] The buffer portion 26 is an elastic member formed on the floating arm 12, and is a mechanism that absorbs the received stress and reduces the stress propagated to the floating arm 12. The buffer portion 26 may be an elastic member including an elastic material such as rubber, for example, it may be a cushion rubber. For example, when the buffer portion 26 includes an elastic material such as rubber, the structure of the buffer portion 26 can be simplified and the cost can be reduced as compared with the case where the buffer portion 26 has a mechanism such as a spring.

[0018] The force sensor 28 is formed on the buffer portion 26, and the first joint portion 30 is formed on the force sensor 28. The force sensor 28 detects at least one of the force and moment applied to the gripping portion 34, which will be described in detail later. The force sensor 28 may be, for example, a six-axis force sensor. In other words, the force sensor 28 may detect the strength of the force along each of the three-axis directions and the strength of the moment with each of the three-axis directions as the rotation axis, at least applied to the gripping portion 34.

[0019] The data of the force or moment detected by the force sensor 28 may be recorded in a recording portion such as a memory (not shown). The control unit 10 may control each part of the arm 4 and the floating unit 6 based on the data recorded in the recording portion, in other words, according to the detection result of the force sensor 28. The specific control method of the arm 4 and the floating unit 6 using the detection result of the force sensor 28 will be described in detail later.

[0020] The first joint portion 30 is joined to the gripping portion 34 described later. Therefore, the gripping portion 34 is formed on the floating arm 12 via the first joint portion 30, the force sensor 28, and the buffer portion 26. Therefore, the force sensor 28 can measure at least the force or moment applied to the gripping portion 34 as described above.

[0021] On the other hand, the second joint 32 connects to the nut runner unit 36, which will be described later. Furthermore, the second joint 32 is directly formed on the buffer portion 26 without going through the force sensor 28. For this reason, the nut runner unit 36 ​​is formed on the floating arm 12 via the buffer portion 26, which is a different component from the force sensor 28. Also, the second joint 32 is located closer to the arm 4 than the force sensor 28. In other words, the force sensor 28 is formed closer to the tip of the arm 4 than the nut runner unit 36.

[0022] <Grip part> The gripping section 34 is a jig for gripping a workpiece, which will be described later. In this embodiment, the control unit 10 controls the position and orientation of the gripping section 34 and the workpiece it grips by controlling each joint of the arm 4 when the gripping section 34 is gripping a workpiece.

[0023] The gripping portion 34 includes, for example, a first joining plate 38, a support frame 40, a protruding portion 42, and a gripping mechanism 44, as shown in schematic diagram A1 of Figure 1. The gripping portion 34 is formed on the first joining portion 30 by joining the first joining plate 38 and the first joining portion 30 with bolts or the like. The protruding portion 42 and the gripping mechanism 44 are formed, for example, on a frame-shaped support frame 40.

[0024] The protruding portion 42 is, for example, a guide for positioning the gripping portion 34 relative to the workpiece, which will be described later. The positioning of the gripping portion 34 relative to the workpiece using the protruding portion 42 will be described in detail later.

[0025] The gripping mechanism 44 is, for example, a mechanism for gripping a workpiece, and may be a clamping mechanism including an air cylinder and a clamp that extends and retracts by the air cylinder. However, it is not limited to this, and depending on the workpiece that the gripping portion 34 grips, the gripping mechanism 44 may employ various conventionally known workpiece gripping members. In this embodiment, for example, by operating each gripping mechanism 44 after positioning the gripping portion 34 relative to the workpiece using the protruding portion 42, the gripping portion 34 can grip the workpiece more securely.

[0026] <Nut Runner Unit> The nut runner unit 36 ​​includes, for example, a second joining plate 46, a support plate 48, and two nut runners 50. The nut runner unit 36 ​​is formed at the second joining portion 32 by joining the second joining plate 46 and the second joining portion 32 with bolts or the like. Each of the two nut runners 50 is formed, for example, on the support plate 48 formed on the second joining plate 46.

[0027] The nut runner 50 may be an electric nut runner driven by, for example, a motor (not shown). The nut runner 50 has an engagement portion 52 at its tip, which includes, for example, a socket that engages with a fastener such as a bolt. The nut runner 50 may, for example, remove a bolt from the two workpieces by rotating the engagement portion 52 with a motor while the bolt connecting the two workpieces is engaged with the engagement portion 52. Each nut runner 50 may also be able to change its position and orientation relative to the support plate 48, and the control unit 10 may control the position and orientation of each nut runner 50 relative to the support plate 48 through the control of the motor described above.

[0028] <Examples of manipulator usage> An example of how to use the manipulator 2 will be explained using Figures 3 and 4. Figure 3 is a schematic perspective view of a vehicle W, including a door W1 which is a first workpiece gripped by the manipulator 2, and a frame W2 which is a second workpiece to which the door W1 is attached, together with the manipulator 2 in this embodiment. Figure 4 is a schematic side view showing the inside of the door W1 shown in Figure 3.

[0029] In this embodiment, the manipulator 2 is a manipulator for performing processing on a vehicle W being transported in a manufacturing line for a vehicle W, including an automobile. In particular, in this embodiment, the manipulator 2 is a manipulator for removing a door W1 that has been temporarily fixed to a frame W2 included in the vehicle W from the frame W2. The process of removing the door W1 from the frame W2 may be performed, for example, after the painting process on the vehicle W has been completed while the door W1 is attached to the frame W2, in order to attach parts to the door W1 and the frame W2.

[0030] As shown in Figure 4, the door W1 includes an opening WA on its inside. In this embodiment, the opening WA is a guide on the door W1 side for positioning the gripping portion 34 relative to the door W1, by which the protruding portion 42 is inserted by a method described later.

[0031] In this embodiment, the process of removing the door W1 from the frame W2 using the manipulator 2 is performed, for example, from the point when the transported vehicle W has been transported to a specific location, such as near the manipulator 2. In this removal process, first, as shown in Figure 3, the door W1 is gripped by the gripping part 34.

[0032] Here, in order to grip the door W1 with the gripping portion 34, the control unit 10 controls the arm 4 to position the gripping portion 34 relative to the door W1. Positioning the gripping portion 34 relative to the door W1 is achieved, for example, by the control unit 10 controlling the arm 4 according to a preset program and moving the floating unit 6 on which the gripping portion 34 is formed.

[0033] The floating unit 6 may further include a door opening mechanism for opening the door W1 of the transported vehicle W from a closed state. Opening the door W1 using this door opening mechanism may be achieved, for example, by the control unit 10 controlling the arm 4 according to a preset program, moving the floating unit 6 on which the gripping portion 34 is formed, and operating the door opening mechanism.

[0034] <Protrusions and openings> The method for positioning the gripping portion 34 relative to the door W1 will be explained in more detail with reference to Figure 5. Figure 5 is a cross-sectional view showing the process of inserting the protruding portion 42 into the opening WA when positioning the gripping portion 34 relative to the door W1. Figure 5 shows, for example, a cross-section of the protruding portion 42 and the inner wall of the door W1 in a plane passing through the protruding portion 42 and the opening WA.

[0035] For example, as shown in each figure of Figure 5, the projection 42 includes a cylindrical portion 42A that engages with the opening WA, and a tapered portion 42B formed on the cylindrical portion 42A, the tapered portion having a smaller diameter towards the tip of the projection 42. For example, the tip of the projection 42 of the tapered portion 42B is located at a position that coincides with the center line 42C passing through the radial center of the cylindrical portion 42A.

[0036] For example, when the protruding portion 42 is inserted into the opening WA and the cylindrical portion 42A engages with the opening WA, the position of the gripping portion 34 relative to the door W1 is fixed. In particular, when the cylindrical portion 42A engages with the opening WA, the center line WC passing through the radial center of the opening WA coincides with the center line 42C.

[0037] Here, the opening WA is formed such that when the protrusion 42 is inserted, the gripping portion 34 is positioned appropriately relative to the door W1 for gripping the door W1. Furthermore, if multiple protrusions 42 are formed on the gripping portion 34, an opening WA corresponding to each protrusion 42 is formed on the inside of the door W1. Therefore, by inserting the protrusion 42 into the opening WA and engaging the cylindrical portion 42A with the opening WA, the gripping portion 34 is positioned relative to the door W1.

[0038] <Training control> In the positioning step of the gripping portion 34 relative to the door W1, the control unit 10 controls the arm 4, and as shown in step S2 of Figure 5, the floating unit 6 moves until the protruding portion 42 is located near the opening WA. In particular, in this embodiment, the control unit 10 moves the floating unit 6 through the control of the arm 4 until the center line 42C passes inside the opening WA.

[0039] Next, the control unit 10 moves the arm 4 in a first direction D1, which is the direction from the cylindrical portion 42A to the tip of the tapered portion 42B, as shown in step S2 of Figure 5. As a result, the protrusion 42 is inserted into the opening WA.

[0040] As described above, the removal of the door W1 from the frame W2 according to this embodiment is performed, for example, when the vehicle W has been transported to a certain position. In this case, the relative position of the manipulator 2 and the vehicle body W is ideally always the same during the removal process. Furthermore, during the removal process, the degree to which the door W1 is opened relative to the frame W2 can be kept constant, and the angle of the door W1 relative to the frame W2 can be kept constant. This makes it possible to ideally keep the relative position of the manipulator 2 and the door W1 constant during the removal process.

[0041] In this embodiment, for example, the control content of the arm 4 by the control unit 10 in positioning the gripping portion 34 relative to the door W1 can be determined by assuming that the center line 42C and the center line WC coincide when the protruding portion 42 is inserted into the opening WA. Therefore, if the control unit 10 controls the arm 4 as assumed, ideally, engagement between the opening WA and the cylindrical portion 42A can be achieved simply by moving the protruding portion 42 in the first direction D1 after the center line 42C and the center line WC coincide.

[0042] However, in the actual manufacturing process of the vehicle W, when the vehicle W is moved onto a conveyor or the like to transport it during the manufacturing process, positional and angular displacements of the vehicle W, or errors in the angle of the door W1 relative to the frame W2, may occur. As a result, a discrepancy may occur in the relative position of the manipulator 2 and the door W1. Therefore, even if the control unit 10 controls the arm 4 as assumed above, an error may occur in the position of the protrusion 42 relative to the opening WA.

[0043] For example, as shown in step S2 of Figure 5, the center line 42C and the center line WC may not overlap. Also, depending on the manufacturing tolerances, the directions of the center line 42C and the center line WC may not be parallel. The diameter of the opening WA may be set such that, for example, even if there is an error in the position of the protrusion 42 relative to the opening WA as described above, the center line 42C always passes through the inside of the opening WA.

[0044] If the center line 42C and the center line WC do not coincide, the projection 42 moves in the first direction D1, causing the tapered portion 42B of the projection 42 to come into contact with the inner circumferential surface of the opening WA, as shown in step S4 of Figure 5. In this state, if the projection 42 attempts to move further in the first direction D1, the force and moment generated by the tapered portion 42B being pressed against the inner circumferential surface of the opening WA are applied to the gripping portion 34.

[0045] Here, the force sensor 28 detects the force and moment applied to the gripping portion 34, for example, when the tapered portion 42B is pressed against the inner circumferential surface of the opening WA described above. Note that the force sensor 28 may detect only one of the force or moment applied to the gripping portion 34.

[0046] Next, the control unit 10 modifies the control of the arm 4 based on the force and moment detected by the force sensor 28 on the gripping portion 34, and moves the protruding portion 42 in a direction that reduces the displacement of the protruding portion 42 with respect to the opening WA. For example, as shown in step S6 of Figure 5, through the control of the arm 4 by the control unit 10, the protruding portion 42 moves not only in the first direction D1 but also in the second direction D2, which is the direction that reduces the displacement of the protruding portion 42 with respect to the opening WA. The control unit 10 may also modify the control of the arm 4 to reduce not only the positional displacement between the center line 42C and the center line WC, but also the directional displacement between the center line 42C and the center line WC.

[0047] In other words, the control unit 10 positions the gripping portion 34 relative to the door W1 by performing tracking control of the protruding portion 42 relative to the opening WA based on the force and moment applied to the gripping portion 34 from the opening WA. This allows the control unit 10 to further improve the accuracy of positioning the gripping portion 34 relative to the door W1. Since the control unit 10 can modify the control content of the arm 4 by tracking control using the force sensor 28, the manipulator 2 does not need to have a separate mechanism in the floating unit 6 for controlling the position and orientation of the gripping portion 34.

[0048] As a result, the gripping portion 34 is positioned relative to the door W1 by being inserted into the opening WA from the protruding portion 42 and the cylindrical portion 42A engaging with the opening WA. In this state, the control unit 10 controls the gripping mechanism 44 of the gripping portion 34 so that the gripping portion 34 grips the door W1.

[0049] Here, during the positioning of the gripping portion 34 relative to the door W1 and the gripping portion 34 gripping the door W1, the gripping portion 34 is subjected to forces and moments, for example, caused by the protrusion 42 being pressed against the opening WA as described above. However, since the gripping portion 34 is formed on the floating arm 12 via a buffer portion 26, the forces and moments acting on the gripping portion 34 are absorbed by the buffer portion 26. As a result, the buffer portion 26 reduces the transmission of forces and moments acting on the gripping portion 34 to the arm 4, thereby improving the accuracy of the control of the arm 4 by the control unit 10. Furthermore, with the above configuration, even if an unintended external force is applied to the arm 4, the transmission of that force to the force sensor 28 is reduced, protecting the force sensor 28.

[0050] <Door Removal> Following the gripping of the door W1 by the gripping unit 34, the control unit 10 controls the nut runner unit 36 ​​to perform processing on the door W1. The processing on the door W1 by the nut runner unit 36 ​​is, for example, to remove the door W1 from the frame W2 by removing the bolts, which are joining members that connect the door W1 and the frame W2.

[0051] More specifically, the control unit 10 controls the position of each nut runner 50 relative to the support plate 48 to engage the bolts that connect the door W1 and the frame W2 with the engaging portion 52 of each nut runner 50. In this state, the control unit 10 controls the rotational drive of the engaging portion 52 of each nut runner 50 to remove the bolts from the door W1 and the frame W2. This allows the door W1 to be removed from the frame W2 using the nut runner unit 36.

[0052] Furthermore, since the gripping portion 34 and the nut runner unit 36 ​​are formed on the same floating arm 12, the position of the nut runner unit 36 ​​relative to the gripping portion 34 is unlikely to shift. Also, when the gripping portion 34 grips the door W1, the position of the gripping portion 34 relative to the door W1 is adjusted. Therefore, while the gripping portion 34 is gripping the door W1, the positional relationship of the nut runner unit 36 ​​relative to the door W1 can be known, and any displacement of the nut runner unit 36 ​​relative to the door W1 can be kept sufficiently small.

[0053] Therefore, in this embodiment, even when the control unit 10 controls the position of the nut runner unit 36 ​​according to a preset program, misalignment between the nut runner unit 36 ​​and the door W1 is unlikely to occur. Thus, the control unit 10 can control the nut runner unit 36 ​​with sufficient accuracy without using the detection results of the force sensor 28.

[0054] Furthermore, since the nut runner unit 36 ​​is formed on the floating arm 12 via a buffer portion 26, the force and moment acting on the nut runner unit 36 ​​are absorbed by the buffer portion 26. As a result, the buffer portion 26 reduces the transmission of the force and moment acting on the nut runner unit 36 ​​to the arm 4, improving the accuracy of the control of the arm 4 by the control unit 10, and also reducing damage to the arm 4.

[0055] Generally, when a tool section includes a rotationally driven component such as a nut runner 50, a relatively large reaction force is applied to the tool section when it is used. However, the reaction force applied to the nut runner unit 36 ​​is absorbed by the buffer section 26 and is therefore less likely to be transmitted to the arm 4, and also less likely to be transmitted to the force sensor 28, which does not have a nut runner unit 36. Therefore, the manipulator 2 can efficiently reduce the transmission of the reaction force generated when using the nut runner 50 to both the arm 4 and the force sensor 28.

[0056] In this embodiment, the nut runner unit 36, which is the tool part of the manipulator 2, is a device for removing the door W1 from the frame W2 by removing the bolts that connect the door W1 and the frame W2 from both, but it is not limited to this. In this embodiment, the tool part may also be a device for releasing the connection between the door W1 and the frame W2, and in particular, the tool part may be a device for removing at least a part of the connecting member that connects the door W1 and the frame W2.

[0057] For example, the door W1 may be attached to the frame W2 via a pin that connects the two, in which case the manipulator 2 may have an arm as a tool for removing the pin from the door W1 and the frame W2. In addition, the member that connects the door W1 and the frame W2, and the tool part of the manipulator 2 for releasing the connection between the door W1 and the frame W2, can each be made of conventionally known materials.

[0058] With the above steps completed, the process of removing the door W1 from the frame W2 using the manipulator 2 is finished. Following the removal of the door W1 from the frame W2 by the nut runner unit 36, the control unit 10 may move the position of the floating unit 6 while the door W1 is being gripped by the gripping unit 34, by controlling the arm 4. In this way, the control unit 10 may move the door W1 that has been removed from the frame W2.

[0059] After the removal process described above, in this embodiment, the door W1 may be reattached to the frame W2 after assembling the components to the door W1 and the frame W2, respectively. The attachment of the door W1 to the frame W2 may be performed by a conventionally known manipulator, for example, using the manipulator 2 according to this embodiment. In this case, the control unit 10 may attach the door W1 to the frame W2 by inserting bolts into the door W1 and the frame W2 through the control of the arm 4, the gripping part 34, and the nut runner unit 36.

[0060] Furthermore, when attaching the frame W2 to the door W1 using the manipulator 2, the gripping portion 34 may be replaced with a jig equipped with a gripping mechanism suitable for attaching the door W1. For example, when attaching the frame W2 to the door W1, interior fittings such as covers are often attached to the inside of the door W1. Therefore, when attaching the frame W2 to the door W1 using the manipulator 2, the gripping portion 34 may be replaced with a jig capable of gripping the door W1 with the interior fittings attached.

[0061] <Summary> The manipulator 2 according to this embodiment comprises an arm 4, a gripping portion 34 for gripping the workpiece, which is a door W1, and a nut runner unit 36 ​​as a tool for machining the door W1. Here, the gripping portion 34 is formed on the arm 4 via a force sensor 28, and the nut runner unit 36 ​​is formed on the arm 4 via a member different from the force sensor 28, which includes a buffer portion 26.

[0062] Therefore, the manipulator 2 according to this embodiment can reduce the transmission of force and moment applied to the nut runner unit 36 ​​to the force sensor 28. Consequently, the need to consider the force and moment generated by the use of the nut runner unit 36 ​​when determining the load capacity of the manipulator 2, taking into account the moment resistance of the force sensor 28, is reduced. Thus, the manipulator 2 can improve its load capacity while allowing at least one of the force and moment applied to the gripping portion 34 to be detected by the force sensor 28.

[0063] Furthermore, in the manipulator 2 according to this embodiment, the nut runner unit 36 ​​is formed on the arm 4 without going through the force sensor 28. As a result, since the nut runner unit 36 ​​is not formed on the force sensor 28, the distance between the force sensor 28 and the gripping part 34 can be brought closer, and consequently, the distance between the force sensor 28 and the workpiece gripped by the gripping part 34 can be brought closer. This reduces the transmission of force and moment generated when the arm 4 is operated while the gripping part 34 is gripping a workpiece to the force sensor 28.

[0064] Furthermore, in this embodiment, the force sensor 28 is formed on the tip side of the arm 4 rather than the nut runner unit 36. As a result, the manipulator 2 can more efficiently reduce the transmission of force and moment applied to the nut runner unit 36 ​​to the force sensor 28, thereby improving the load-bearing capacity of the manipulator 2.

[0065] Furthermore, the manipulator 2 includes a control unit 10 that controls the position of the gripping portion 34 and the machining of the door W1 by the nut runner unit 36. In particular, the control unit 10 controls the position of the gripping portion 34 according to the force and moment detected by the force sensor 28. As a result, the manipulator 2 can position the gripping portion 34 relative to the door W1 with greater precision.

[0066] For example, the positioning of the gripping portion 34 relative to the door W1 is achieved by the control unit 10's control of the protruding portion 42 of the gripping portion 34 relative to the opening WA of the door W1. In this case, even if there is a misalignment in the position of the door W1 relative to the manipulator 2, the control unit 10 can accurately position the gripping portion 34 relative to the door W1.

[0067] In this embodiment, the force sensor 28 may be a 6-axis force sensor. Generally, 6-axis force sensors can detect force and moment more precisely than 1-axis force sensors that detect force in only one specific direction, but they often have lower moment resistance due to their more complex mechanism. Therefore, when the force sensor 28 is a 6-axis force sensor, the effect of the manipulator 2 in this embodiment in reducing the transmission of force and moment from the nut runner unit 36 ​​to the force sensor 28 is more pronounced. Furthermore, when the force sensor 28 is a 6-axis force sensor, the effect of reducing the transmission of force and moment to the force sensor 28 when the arm 4 is moved while the gripping part 34 is gripping a workpiece is also more pronounced.

[0068] In this embodiment, the manipulator 2 includes a nut runner unit 36 ​​as a tool section, which includes a nut runner 50 for removing the door W1 gripped by the gripping section 34 from the frame W2. In particular, the nut runner 50 engages the bolts joining the door W1 and the frame W2 with the engaging section 52, and then rotates the bolts by the rotational drive of the engaging section 52 to remove them from the door W1 and the frame W2.

[0069] Thus, generally, a device for releasing the joint between two members requires applying a relatively strong force or moment to each member in order to release the joint. In particular, a device for removing at least a portion of a joining member that connects two members often requires not only gripping the joining member but also applying force to the joining member to detach it from the two members. Therefore, if the above-described device is adopted as the tool part of the manipulator 2 according to this embodiment, the reaction force generated when using the tool part can be transmitted to the arm 4 and the force sensor 28 more efficiently.

[0070] In this embodiment, for example, the manipulator 2 may be equipped with various conventionally known processing devices as tool parts, in addition to the nut runner unit 36, for processing the door W1 gripped by the gripping part 34. Even in this case, since the tool part is formed on the arm 4 without going through the force sensor 28, the manipulator 2 reduces the transmission of reaction force applied to the tool part to the force sensor 28.

[0071] Furthermore, while this embodiment describes an example where the manipulator 2 is used in a vehicle manufacturing line W, it is not limited to this. For example, the manipulator 2 may be used as various conventional manipulators for gripping and processing a workpiece being transported.

[0072] However, generally speaking, when using a manipulator to remove a vehicle door from its frame, a certain degree of precision is required in positioning the manipulator's gripping portion relative to the door. Furthermore, due to the weight of the door, the manipulator used to remove the door from the frame must have a certain load-bearing capacity.

[0073] The manipulator 2 according to this embodiment can position the gripping portion 34 with respect to the workpiece with greater precision and can also improve the load-bearing capacity of the manipulator 2. Therefore, by adopting the manipulator 2 according to this embodiment as a manipulator in the manufacturing line of the vehicle W, the yield of the vehicle W can be efficiently improved and damage or wear of the manipulator 2 can be efficiently reduced.

[0074] This disclosure is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the different technical means disclosed in each embodiment are also included in the technical scope of this disclosure. [Explanation of symbols]

[0075] 2 Manipulators 4 Arms 10 Control Unit 26 Buffer section 28 Force Sensor 34 Gripping part 36. Nut Runner Unit (Tool Section) 42 Protrusion 50 Nut Runner W Vehicle W1 Door W2 Frame WA opening

Claims

1. An arm and, A force sensor formed on the aforementioned arm, A gripping portion is formed on the arm via the force sensor and grips the first workpiece, A tool portion formed on the arm via a member different from the force sensor, the tool portion performing machining on the first workpiece while it is being gripped by the gripping portion, A manipulator comprising a control unit that controls the position of the gripping portion according to the detection result from the force sensor.

2. The gripping portion includes a protruding portion, The first workpiece includes an opening, The manipulator according to claim 1, wherein the control unit positions the gripping portion with respect to the first workpiece by tracking control, which moves the protruding portion in a direction that reduces the displacement of the protruding portion relative to the opening based on the force and moment applied to the gripping portion from the opening, thereby engaging the protruding portion with the opening.

3. The manipulator according to claim 1 or 2, wherein the force sensor is a 6-axis force sensor.

4. The manipulator according to any one of claims 1 to 3, wherein the force sensor is formed on the tip side of the arm rather than the tool portion.

5. It also has a cushioning section, The manipulator according to any one of claims 1 to 4, wherein at least one of the force sensor and the tool portion is formed on the arm via the buffer portion.

6. The manipulator according to claim 5, wherein the buffer portion is an elastic member containing an elastic material.

7. The manipulator according to any one of claims 1 to 6, wherein the tool portion is a device for releasing the joint between the first workpiece and a second workpiece different from the first workpiece.

8. The manipulator according to claim 7, wherein the tool portion is a device for removing at least a portion of a joining member that joins the first workpiece and the second workpiece.

9. The manipulator according to claim 7 or 8, wherein the tool portion includes a nut runner.

10. The manipulator according to any one of claims 8 to 9, wherein the first workpiece is a vehicle door and the second workpiece is the frame of the vehicle.

Images