Robotic arm

Abstract

The present application provides a robot capable of suppressing manufacturing cost lower and not affected by the influence of the finger member flexure, and can always detect accurate holding force regardless of which part of the finger member clamps the workpiece. The robot is provided with: a plurality of finger members (first finger member, second finger member) that press and support the workpiece (6), and a pressing force detection mechanism (7) provided to the finger member (second finger member) for pressing force detection. The pressing force detection mechanism is provided with: a movable member (second contact member) supported to the finger member for pressing force detection in a manner movable in the direction of supporting the workpiece via a shaft member (56), a spring member (62) that applies force to the movable member in the direction of supporting the workpiece, a restriction structure (stop member) that restricts the movement of the movable member against the spring force of the spring member, and a sensor (41) whose value changes according to the amount of movement of the movable member.

Description

Technical Field

[0001] This invention relates to a robotic arm equipped with a sensor that detects the force on a workpiece supported by multiple finger components. Background Technology

[0002] As existing robotic arms, those described in Patent Documents 1-3 are known, for example. The robotic arm disclosed in Patent Document 1 includes a pair of finger members that move in a manner that allows them to approach or separate from each other, and employs a structure that uses the tip of the finger members to grasp a workpiece. The base of the finger members is supported on a drive device via a force sensor. The force sensor detects the force applied to the finger members when they grasp the workpiece.

[0003] Patent Document 2 discloses a robotic arm comprising: a pair of finger members, contact members elastically supported by spring members at portions of these finger members facing each other, and a sensor for detecting the displacement of the spring members. The contact members are members that contact the workpiece. The spring members are displaced by the force applied to the contact members when the workpiece is held by the pair of finger members.

[0004] The robotic arm disclosed in Patent Document 3 includes: a pair of finger components, and tactile sensors disposed at the locations where these finger components are opposite each other and in contact with the workpiece. The tactile sensors are composed of electrostatic capacitive pressure sensors.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent No. 5543539

[0008] Patent Document 2: Japanese Patent Application Publication No. 8-39474

[0009] Patent Document 3: Japanese Patent Application Publication No. 2012-127764 Summary of the Invention

[0010] The problem that the invention aims to solve

[0011] The finger member disclosed in Patent Document 1 is cantilevered and supported on the drive device. When gripping a workpiece, the front end may flex relative to the base end. If the finger member flexes, the force sensor's detection value becomes inaccurate.

[0012] The adverse conditions caused by the deflection of such finger components, as disclosed in Patent Document 2 or Patent Document 3, can be eliminated to some extent by setting a sensor in the part of the finger component that contacts the workpiece.

[0013] However, in the robotic arm shown in Patent Document 2, since the contact member is elastically supported by the spring member, the contact member may sometimes tilt relative to the finger member when the workpiece is pressed against the end of the contact member, for example. In such cases, a force component is generated in a direction different from the displacement direction of the spring member, causing the sensor's detection value to become inaccurate. That is, the sensor's detection value may differ depending on whether the workpiece is in contact with the end of the contact member or with the center of the contact member. Furthermore, in the robotic arm shown in Patent Document 3, the electrostatic capacitive pressure sensor constituting the tactile sensor is expensive, thus increasing manufacturing costs.

[0014] The purpose of this invention is to provide a robotic arm that can keep manufacturing costs low and is unaffected by finger component deflection, and can always detect accurate gripping force regardless of the position of contact with the workpiece.

[0015] Solution for solving the problem

[0016] To achieve this objective, the robotic arm of the present invention comprises: a plurality of finger members that press and support a workpiece by moving along workpiece support directions that are close to or separate from each other; and a pressure detection mechanism disposed on at least one of the plurality of finger members, namely, a pressure detection finger member, the pressure detection mechanism comprising: a movable member that is supported on the pressure detection finger member in a manner movable in the workpiece support direction via a shaft member extending in the workpiece support direction, and transmitting the pressing force when supporting the workpiece; a spring member that applies a force to the movable member in the direction of supporting the workpiece; a limiting structure that limits the movement of the movable member, which is subjected to the spring force of the spring member, in the workpiece support direction; and a sensor that detects a change in value based on the amount of movement of the movable member relative to the pressure detection finger member when it overcomes the spring force of the spring member.

[0017] Alternatively, in the present invention, the finger member of the manipulator is formed as a rod extending in a direction orthogonal to the workpiece support direction. The shaft members are respectively disposed at multiple positions in the finger member for pressure detection in a direction orthogonal to the workpiece support direction and pass through the finger member. The movable member is formed as a plate extending in the direction in which the multiple shaft members are arranged. When the side of the finger member for pressure detection opposite to the workpiece is arranged in the workpiece support direction, both ends in the direction in which the multiple shaft members are arranged are fixed to one end of the shaft member. The limiting structure includes a stop member, which is integrally movable and mounted to the other end of the shaft member, opposite the finger member for pressure detection. The spring member applies force to the portion between the multiple shaft members in the movable member.

[0018] In this invention, the spring member may also be configured to apply force to the central portion of the plurality of shaft members of the movable member in the direction of their arrangement.

[0019] Alternatively, in the present invention, a screw member is screwed onto the stop member in the manipulator, and the screw member contacts the other side of the pressure detection finger member located on the opposite side of the workpiece. The interval between the movable member and the pressure detection finger member is adjusted by changing the screw member's screwing depth.

[0020] Alternatively, in the present invention, the plurality of finger members are movably arranged in three radially extending moving paths such that the extending direction of each moving path is the workpiece support direction. One of the three finger members is the finger member for pressure detection. The three moving paths are equipped with a driving device that causes all finger members to move synchronously toward the center side or the outer side of the three moving paths.

[0021] Alternatively, in the present invention, the shaft member passes through the pressure-detecting finger member along the workpiece support direction in the manipulator, and the movable member has a pair of spring-bearing portions that clamp the pressure-detecting finger member from both sides in the workpiece support direction. The spring member includes: a first spring member disposed between the pressure-detecting finger member and one of the spring-bearing portions, applying force to one of the spring-bearing portions in a direction away from the finger member; and a second spring member disposed between the pressure-detecting finger member and the other spring-bearing portion, applying force to the other spring-bearing portion in a direction away from the finger member. The limiting structure is constructed using the pressure-detecting finger member, one of the spring-bearing portions, and the other spring-bearing portion.

[0022] Alternatively, in the present invention, the finger member in the manipulator is formed as a rod extending in a direction orthogonal to the workpiece support direction, and the two finger members are arranged to move parallel to each other in the workpiece support direction. One of the two finger members is the finger member for pressure detection. The spring bearing portion has a contact portion, which is provided at both ends of the movable member in the workpiece support direction and contacts the workpiece.

[0023] Alternatively, in the present invention, the finger member in the manipulator is formed as a rod extending in a direction orthogonal to the workpiece support direction, and the two finger members are arranged to move parallel to each other in the workpiece support direction. One of the two finger members is the finger member for pressure detection, and the movable member and the other finger member are respectively provided with claws that contact the workpiece.

[0024] Alternatively, in the present invention, the plurality of finger members are movably arranged in three radially extending moving paths such that the extending direction of each moving path is the workpiece support direction. One of the three finger members is the finger member for pressure detection. The spring bearing portion has a contact portion, which is provided at both ends of the movable member in the workpiece support direction and contacts the workpiece. The three moving paths are equipped with a driving device, which causes all finger members to move synchronously toward the center side or the outer side of the three moving paths.

[0025] Alternatively, in the present invention, the plurality of finger members are movably arranged in three radially extending moving paths such that the extending direction of each moving path is the workpiece support direction. One of the three finger members is the finger member for pressure detection. The movable member and the other finger members that are not the finger member for pressure detection are respectively provided with claws that contact the workpiece. The three moving paths are provided with a driving device that causes all finger members to move synchronously toward the center side or the outer side of the three moving paths.

[0026] Alternatively, in the present invention, the sensor in the robotic arm may consist of a permanent magnet and a Hall element for detecting the magnetic field of the permanent magnet, with one component of the permanent magnet and the Hall element disposed on the finger component for pressure detection, and the other component disposed on a component that moves integrally with the movable component.

[0027] Alternatively, in the present invention, the sensor in the manipulator may consist of a permanent magnet and a Hall element for detecting the magnetic field of the permanent magnet. The stop member is a member that moves integrally with the movable member and has an extension extending along the outer surface of the finger member for pressing pressure detection in a direction orthogonal to the workpiece support direction. One of the permanent magnet and the Hall element is mounted on the outer surface of the finger member for pressing pressure detection, and the other is mounted on the extension of the stop member.

[0028] Invention Effects

[0029] According to the present invention, a robotic arm can be provided that can keep manufacturing costs low and is unaffected by finger component deflection, and can always detect accurate gripping force regardless of the position of contact with the workpiece. Attached Figure Description

[0030] Figure 1 This is a top view of the robotic arm according to the first embodiment of the present invention.

[0031] Figure 2 This is a side view of the robotic arm.

[0032] Figure 3 yes Figure 2 Sectional view along line III-III.

[0033] Figure 4 yes Figure 3 The three-dimensional sectional view along line IV-IV.

[0034] Figure 5 It is a cross-sectional view showing the main parts in an enlarged manner.

[0035] Figure 6 It refers to a three-dimensional drawing of a component.

[0036] Figure 7 yes Figure 1 Sectional view along line VII-VII.

[0037] Figure 8 This is a three-dimensional view showing the structure of the drive system.

[0038] Figure 9 It is a 3D diagram of the frame.

[0039] Figure 10 It is an exploded 3D view of the pressure testing mechanism.

[0040] Figure 11 This is a top view showing a second embodiment of the robotic arm.

[0041] Figure 12 This is a perspective view showing a third embodiment of the robotic arm.

[0042] Figure 13 This is a perspective view showing a third embodiment of the robotic arm.

[0043] Figure 14 This is a sectional view of the main part.

[0044] Figure 15 This is a sectional view of the main part.

[0045] Figure 16 This is a perspective view showing a fourth embodiment of the robotic arm.

[0046] Figure 17 This is a perspective view showing the fourth embodiment with the outer shell and claws of the robotic arm removed.

[0047] Figure 18 This is a sectional view of the main part.

[0048] Figure 19 This is a perspective view showing the fifth embodiment of the robotic arm.

[0049] Figure 20 This is a perspective view showing the state in the fifth embodiment where the cover and claws of the robotic arm's outer shell have been removed.

[0050] Figure 21 This is a cross-sectional view of a part of the robotic arm.

[0051] Figure 22 This is a sectional view of the main part.

[0052] Figure 23 This is a sectional view of the main part.

[0053] Figure 24 It is an exploded perspective view used to illustrate the structure of the drive system and movable components.

[0054] Figure 25 This is a perspective view showing the sixth embodiment of the robotic arm.

[0055] Figure 26 This is a perspective view showing the seventh embodiment of the robotic arm.

[0056] Explanation of reference numerals in the attached figures:

[0057] 1, 81, 100, 121, 200, 300, 400… robotic arms,

[0058] 3. 206… drive unit,

[0059] 4…First finger component 4,

[0060] 5…Second finger component 5 (one-sided finger component),

[0061] 6, 86…workpieces,

[0062] 7, 101, 122, 246… according to the pressure testing agency,

[0063] 41…sensor,

[0064] 54…Second contact member 54 (contact member),

[0065] 47…Second hand block,

[0066] Shaft components 56, 231…

[0067] 61…stopping component,

[0068] 62…Spring component,

[0069] 62A, 234… First spring component,

[0070] 62B, 235… Second spring component,

[0071] 65b…extension,

[0072] 66… Adjusting screw (screw component),

[0073] 68…permanent magnets,

[0074] 72…Hall element,

[0075] 104, 125, 202… movable components,

[0076] 103… Fourth contact component,

[0077] 107… one side of the spring bearing part,

[0078] 107a, 108a… contact parts,

[0079] 108…The other side's spring bearing part,

[0080] 111, 236… Restriction structure,

[0081] 123, 201...claw piece,

[0082] 202A…First half (one side of the spring bearing part),

[0083] 202B…Second half (the spring bearing part on the other side),

[0084] 205…mobile pathway. Detailed Implementation

[0085] (First Implementation)

[0086] The following is for reference Figures 1-10 One embodiment of the robotic arm of the present invention will be described in detail.

[0087] Figure 1 The robotic arm 1 shown is a robotic arm installed on an industrial robot (not shown) for use, and has a drive unit 3 housed in the housing 2 (see reference). Figure 3 ), and a pair of finger members 4 and 5 that are connected to the drive unit 3 and protrude from the housing 2.

[0088] These finger members 4 and 5 are driven by the driving device 3, thereby moving in a direction of mutual approach or separation. When the workpiece 6 is positioned between these finger members 4 and 5, the pair of finger members 4 and 5 approach each other, thereby clamping and holding (supporting) the workpiece 6. In this embodiment, the direction in which the pair of finger members 4 and 5 approach each other corresponds to the "workpiece support direction" in this invention.

[0089] In the following description of the robotic arm 1, for convenience, the direction in which the finger members 4 and 5 protrude from the outer shell 2 is defined as the front of the robotic arm 1, the opposite direction is defined as the rear, and the direction in which the pair of finger members 4 and 5 are arranged is defined as the left-right direction of the robotic arm 1. Figure 1 The side of the paper that is perpendicular to the front is set as the top, and the side closer to the front is set as the top. Figure 1 The inside of the paper is set to the bottom. Additionally, below, the pair of finger components 4 and 5, in... Figure 1The finger member 4 located on the left is referred to as the "first finger member 4", and the finger member 5 located on the right is referred to as the "second finger member 5". In this embodiment, the second finger member 5 is equivalent to "one of the finger members" in this invention. Details will be described later, but a pressure detection mechanism 7 is provided at the front end of the second finger member 5. The pressure detection mechanism 7 is used to detect the force exerted by the second finger member 5 on the workpiece 6.

[0090] (Description of the drive unit)

[0091] like Figure 3 As shown, the drive unit 3 is constructed by assembling functional components into a frame 11 that is rectangular when viewed from above. Figure 3 The cutting position is Figure 2 The position indicated by line III-III. (As shown) Figure 9 As shown, the frame 11 is composed of a pair of left and right side plates 12 and 13, an upper front plate 14 connecting the upper front ends of the side plates 12 and 13 to each other, a lower front plate 15 connecting the lower front ends of the side plates to each other, and a rear plate 16 connecting the rear ends of the side plates 12 and 13 to each other.

[0092] like Figure 3 As shown, the functional components assembled on the frame 11 include a drive motor 21 housed in the rear of the frame 11, a threaded shaft 22 that runs horizontally through the front of the frame 11 in the left-right direction of the robot arm 1, and a component that is rotatably supported on the frame 11. Figure 3 The intermediate gear 23 located on the left side plate 12, and the control unit 24 provided on the upper front plate 14 and rear plate 16 (see reference). Figure 4 ), and mounting accessories 25, etc., are provided on the rear panel 16.

[0093] The drive motor 21 serves as the power source for gripping the workpiece 6 using the first finger member 4 and the second finger member 5, and employs a component capable of forward and reverse rotation. The drive motor 21 is fixed to the frame 11 with its axial direction pointing left to right, and its output shaft 26 protrudes from the left end. A power cable 27 for power supply or control is connected to the right end of the drive motor 21. The cable 27 passes through a connector 28 mounted on the housing 2 (see reference). Figure 1 , Figure 2 It connects to the controller of an industrial robot (not shown).

[0094] The output shaft 26 protrudes to the left of the frame 11 through a through hole 12a formed in the side plate 12 on the left side of the frame 11, and is connected to the threaded shaft 22 via a gear transmission mechanism 31. Figure 8As shown, the gear transmission mechanism 31 consists of a drive gear 32 mounted on the output shaft 26, a driven gear 33 mounted on the threaded shaft 22, and an intermediate gear 23 that meshes with the drive gear 32 and the driven gear 33.

[0095] Threaded shaft 22 Figure 3 As shown, the first and second finger members 4 and 5 are pierced through each other and supported rotatably on the side plates 12 and 13 via bearings 34 and 35 at their respective ends. A first external thread 36 is formed on the left side of the threaded shaft 22, and a second external thread 37 is formed on the right side of the threaded shaft 22. On the other hand, a first internal thread 38 is formed in the portion through which the threaded shaft 22 of the first finger member 4 passes, for engaging with the first external thread 36, and a second internal thread 39 is formed in the portion through which the threaded shaft 22 of the second finger member 5 passes, for engaging with the second external thread 37. The first external thread 36 and the first internal thread 38 are formed in the opposite direction to the second external thread 37 and the second internal thread 39.

[0096] The control unit 24 controls the rotation, stopping, rotation direction, and drive torque of the drive motor 21 based on control signals from the controller of the industrial robot (not shown) and the detection values ​​from the sensor 41. The gripping force when the workpiece 6 is gripped using the first and second finger members 4 and 5 is based on the sensor 41 (see reference 7) equipped with the pressing pressure detection mechanism described later. Figure 1 The output of the control unit 24 or the controller of the industrial robot is calculated by the calculation.

[0097] Mounting accessory 25 includes a mounting member 25a that can be attached to and detached from the frame 11. The front end of the mounting member 25a is fixed to a mounting base for an industrial robot (not shown).

[0098] (Referring to the description of the components)

[0099] like Figure 8 As shown, the first and second finger components 4 and 5 have first and second sliding blocks 42 and 43 through which the threaded shaft 22 passes, and mounting bolts 44 and 45 (see reference). Figure 3 The first and second hand blocks 46 and 47, etc., are installed on these first and second sliding blocks 42 and 43. The aforementioned first and second internal threads 38 and 39 are formed on the first and second sliding blocks 42 and 43.

[0100] like Figure 4 As shown, multiple cylindrical rollers 48 are mounted rotatably at the upper and lower ends of the first and second sliding blocks 42 and 43 via bolts 49. Figure 4 The cutting position is Figure 3The position is indicated by line IV-IV. In this embodiment, the rollers 48 are each made of ball bearings and are arranged in the same position in the front-back direction of the robot 1 along the left-right direction. They rotate relative to the first and second sliding blocks 42 and 43 with their respective axes in the up-down direction as the center.

[0101] Rollers 48, located at the upper ends of the first and second sliding blocks 42 and 43, are inserted into the first elongated hole 51 formed in the upper front plate 14 of the frame 11 (see reference). Figure 9 Rollers 48, located at the lower ends of the first and second sliding blocks 42 and 43, are inserted into second elongated holes 52 formed in the lower front plate 15 of the frame 11. The first and second elongated holes 51 and 52 are formed such that they extend from the left end to the right end of the frame 11 at the same position in the longitudinal direction of the robot 1. The opening width (width in the longitudinal direction) of the first and second elongated holes 51 and 52 is such that a small gap is formed between the hole wall and the outer peripheral surface of the roller 48.

[0102] By inserting roller 48 into the first and second elongated holes 51 and 52, the rotation of the first and second finger members 4 and 5 is restricted when the threaded shaft 22 rotates. Therefore, by rotating the threaded shaft 22, a propulsive force is exerted on the first and second internal threads 38 and 39 in the axial direction of the threaded shaft 22, and the first and second finger members 4 and 5 move parallel to each other in the left-right direction of the manipulator 1. The first external thread 36 of the threaded shaft 22 and the first internal thread 38 of the first finger member 4 are formed in a manner opposite to the direction of the second external thread 37 and the second internal thread 39. Therefore, for example, when the threaded shaft 22 rotates clockwise, the first and second finger members 4 and 5 move, for example, in a direction approaching each other; when the threaded shaft 22 rotates counterclockwise, the first and second finger members 4 and 5 move in a direction separating each other. At this time, roller 48 contacts and rolls against the hole walls of the first and second elongated holes 51 and 52.

[0103] The first and second hand blocks 46 and 47 are respectively formed into prism shapes, such as Figure 3 As shown, the first and second sliding blocks 42 and 43 are mounted to their front ends with bolts 44 and 45 in a position where the long side points in the forward / backward direction of the robot 1. First and second contact members 53 and 54 are provided on the opposing portions of the first and second hand blocks 46 and 47, in other words, on the sides 46a and 47a opposite to the workpiece 6. The first and second contact members 53 and 54 are plate-shaped, extending along the long side of the first and second finger members 4 and 5, and are shaped to substantially cover the opposing sides of the first and second hand blocks 46 and 47.

[0104] like Figure 3As shown, the first contact member 53, which is provided on the first hand block 46, is fixed to the first hand block 46 at both ends in the front-rear direction by screws 55.

[0105] The second contact member 54, which is provided on the second hand block 47, constitutes part of the pressure detection mechanism 7. The second contact member 54 is supported on the second hand block 47 in a manner that allows it to move freely in the left and right direction by means of two shaft members 56, which will be described later, when the side portion 47a of the second hand block 47 opposite to the workpiece 6 is arranged in the left and right direction (workpiece support direction) of the robot arm 1.

[0106] (As per the pressure testing agency's instructions)

[0107] like Figures 5-7 as well as Figure 10 As shown, the pressure detection mechanism 7 consists of two shaft members 56 that pass through the second hand block 47 along the left-right direction of the robot arm 1, a second contact member 54 installed at one end of the shaft member 56, a stop member 61 installed at the other end of the shaft member 56, a spring member 62 that applies force to the portion between the multiple shaft members 56 in the second contact member 54, and a sensor 41 (see reference). Figure 7 It is composed of, etc. In this embodiment, the spring member 62 is provided in the central part of the long side (front-back direction) of one side part 47a of the second hand block 47 in such a way that it is optimal when force is applied to the second contact member 54.

[0108] The shaft member 56 is movably fitted into the cylindrical bearing member 63 fixed to the second hand block 47. In this embodiment, the shaft member 56 and the bearing member 63 are disposed together at multiple locations separated along the long side direction (orthogonal to the workpiece support direction) of the second hand block 47. In this embodiment, the shaft member 56 is located at both ends along the long side direction of one side portion 47a of the second hand block 47. The two ends of the second contact member 54 along the long side direction are fixed to one end of the shaft member 56 with screws 64. In this embodiment, the second contact member 54 corresponds to the "movable member" in this invention.

[0109] like Figure 10As shown, the stop member 61 consists of an adjustment plate 65 formed by bending a sheet of metal into a predetermined shape, and an adjustment screw 66 mounted on the adjustment plate 65. In this embodiment, the stop member 61 corresponds to the "restriction structure" in this invention. The adjustment plate 65 has a flat stop portion 65a that is fixed to the other end of the shaft member 56 by a fixing screw 67, and an extension portion 65b that extends upward from the stop portion 65a and along the upper surface 47b (the outer surface in the direction orthogonal to the workpiece support direction) of the second hand block 47. A permanent magnet 68, which constitutes part of the sensor 41, is mounted on the extension portion 65b. In this embodiment, the stop member 61 corresponds to the "member that moves integrally with the movable member" in this invention.

[0110] Adjusting screw 66 is equivalent to the "screw member" in this invention, and is screwed into the threaded hole 69 formed in the center of the stop portion 65a (see reference). Figure 5 The adjusting screw 66 is secured in the screwed-in position by the locking nut 70. The front end of the adjusting screw 66 abuts against the other side 47c of the second hand block 47, located opposite to the workpiece 6. Because the front end of the adjusting screw 66 abuts against the other side 47c of the second hand block 47, the movement of the shaft member 56 to the left (towards the workpiece 6) is restricted. The movement of the shaft member 56 to the right (away from the workpiece 6) is restricted because the second contact member 54 abuts against one side 47a of the second hand block 47. Therefore, the shaft member 56 can move axially between the position where the second contact member 54 abuts against one side 47a of the second hand block 47 and the position where the adjusting screw 66 abuts against the other side 47c of the second hand block 47. The travel of the shaft member 56 is defined by the adjusting screw 66 and can be adjusted by changing the amount of screwing the adjusting screw 66 relative to the stop 65a. In addition, the distance between the second contact member 54 and the second hand block 47 can be adjusted by changing the amount of screwing in the adjusting screw 66.

[0111] Spring component 62 is composed of a compression helical spring, such as Figure 5 As shown, it is held in a state where it is housed in the recess 71 formed in the second hand block 47 and compressed between the bottom 71a of the recess 71 and the second contact member 54. The spring force of the spring member 62 is applied to the second contact member 54, thereby causing the assembly consisting of the second contact member 54, the shaft member 56, and the stop member 61 to advance to the left of the robot 1 (towards the workpiece 6) relative to the second hand block 47. This advance continues until the adjusting screw 66 abuts against the other side 47c of the second hand block 47.

[0112] like Figure 6 (A), (B) and Figure 7As shown in (A) and (B), the sensor 41 includes a Hall element 72 mounted on the upper surface 47b of the second hand block 47 and a permanent magnet 68 mounted on the extension 65b of the stop member 61, and is configured to detect a change in value based on the amount of movement of the second contact member 54 when it approaches the second hand block 47. Figure 6 (A) and Figure 7 (A) shows the state when the robot arm 1 is not holding the workpiece 6. Figure 6 (B) and Figure 7 (B) shows the state when the robot arm 1 holds the workpiece 6. It should be noted that the positions for mounting the permanent magnet 68 and the Hall element 72 are not limited to the positions described above. That is, the permanent magnet 68 can be mounted on the upper surface 47b of the second hand block 47, and the Hall element 72 can be mounted on the extension 65b of the stop member 61.

[0113] Hall element 72 is connected by a lead 73 extending along the second hand block 47 and the second sliding block 43 (see reference). Figure 1 It is connected to the control unit 24 and sends the magnetic field strength as detection data to the control unit 24.

[0114] The permanent magnet 68 is mounted on the extension 65b of the stop member 61 and is located near and above the Hall element 72. The strength of the magnetic field of the permanent magnet 68 detected by the Hall element 72 is... Figure 6 (A) and Figure 7 The initial position where the second contact member 54 is not in contact with the workpiece 6, as shown in (A), is the maximum state.

[0115] When the first and second finger components 4 and 5 are clamped from the workpiece 6 by the first contact component 53 and the second contact component 54, the state is as follows: Figure 6 When moving closer to each other as shown in (B), as Figure 7 As shown in (B), the second contact member 54 approaches the second hand block 47 while compressing the spring member 62. Thus, by moving the second contact member 54, the permanent magnet 68 moves in the same direction by the same amount as the second contact member 54, causing a phase shift between the permanent magnet 68 and the Hall element 72, and weakening the magnetic field detected by the Hall element 72. In other words, the sensor 41 is configured to detect a change in value based on the amount of movement of the second contact member 54 as it approaches the second hand block 47.

[0116] The control unit 24 calculates the movement of the permanent magnet 68 (second contact member 54) based on the change in the strength of the magnetic field. Furthermore, the control unit 24 calculates, for example, the force exerted by the second contact member 54 on the workpiece 6, i.e., the holding force, based on the spring constant of the spring member 62 and the movement, and controls the rotation of the motor 21 in a manner that makes the holding force a target value.

[0117] (Explanation of the effects of the first embodiment)

[0118] In the robot 1 of this embodiment, the following structure is adopted: the second contact member 54, which contacts the workpiece 6, is movably supported on the second hand block 47 (finger member) via the shaft member 56. The amount of movement of the second contact member 54 when it approaches the second hand block 47 against the spring force of the spring member 62 is detected by the sensor 41. Therefore, a robot can be provided that can detect accurate gripping force without being affected by the deflection of the first and second finger members 4 and 5 when gripping the workpiece, and, due to its simple structure, the manufacturing cost can be kept low.

[0119] In this embodiment, the shaft members 56 are respectively disposed at multiple positions separated along the long side of the second hand block 47. The second contact member 54 is formed as a plate extending along the long side of the second hand block 47, and its two ends along the long side are fixed to the shaft members 56. In addition, the spring member 62 applies force to the portion between the multiple shaft members 56 in the second contact member 54.

[0120] Therefore, when the workpiece 6 is held, the second contact member 54 moves parallel to the second hand block 47. Therefore, no matter which part of the second contact member 54 is used to clamp the workpiece 6, no extra component force will be generated that acts in a direction other than the holding direction. Therefore, the accurate holding force can always be detected regardless of the position of the workpiece 6 in contact with the second contact member 54.

[0121] In this embodiment, the spring member 62 has a structure that applies force to the central portion of the second contact member 54 in the long side direction. Therefore, the spring force of the spring member 62 can apply force to the second contact member 54 in a manner that does not impede the parallel movement of the second contact member 54.

[0122] In this embodiment, the stop member 61 is screwed with an adjusting screw 66 that contacts the other side 47c of the second hand block 47 located on the opposite side of the workpiece 6. The distance between the second contact member 54 and the second hand block 47 is adjusted by changing the amount of screwing in the adjusting screw 66.

[0123] Therefore, the initial load applied from the spring member 62 to the second contact member 54 can be easily adjusted by changing the amount of screwing in the adjusting screw 66.

[0124] The sensor 41 in this embodiment consists of a Hall element 72 disposed on the second hand block 47 and a permanent magnet 68 disposed on the stop member 61 in such a way that the Hall element 72 detects a magnetic field.

[0125] Therefore, when detecting the amount of movement of the second contact member 54 in a non-contact manner, it is possible to achieve this at a lower cost, for example, compared to using a sensor for optical detection.

[0126] In this embodiment, the Hall element 72 is mounted on the outer surface, i.e., the upper surface 47b, of the second hand block 47 in a direction orthogonal to the workpiece support direction. The permanent magnet 68 is mounted on the extension 65b of the stop member 61, which extends along the upper surface 47b of the second hand block 47. Therefore, the permanent magnet 68 and the Hall element 72 can be separated from the workpiece 6 by the second contact member 54, making it difficult for moisture or oil adhering to the workpiece 6 to reach the permanent magnet 68 or the Hall element 72 even if it is scattered during workpiece handling. Therefore, there is no need for special waterproof or anti-fouling structures for the permanent magnet 68 or the Hall element 72, thus providing a robotic arm with further reduced manufacturing costs.

[0127] (Second Implementation)

[0128] In the above embodiments, an example is shown of applying the invention to a robotic arm with a structure that uses a pair of finger members to grip a workpiece. However, as Figure 11 As shown, the present invention can also be applied to a robotic arm 81 that inserts a pair of finger components into holes in a workpiece to maintain the workpiece's structure. Figure 11 In the middle, for the passage Figures 1-10 For components that are identical or equivalent to those described, use the same reference numerals and omit detailed descriptions where appropriate.

[0129] Figure 11 The first and second finger members 4 and 5 of the shown manipulator 81 are designed for insertion into the hole 86a of the workpiece 86. These first and second finger members 4 and 5 are pressed against the hole wall of the hole 86a by moving in a mutually separating direction to support the workpiece 86. The first and second contact members 53 and 54 of the first and second finger members 4 and 5 are located at positions facing the hole wall of the hole 86a.

[0130] By adopting this embodiment, it is also possible to provide a robotic arm that can detect accurate gripping force without being affected by the deflection of the first and second finger components 4 and 5 when supporting the workpiece, and, due to its simple structure, can keep manufacturing costs low.

[0131] (Third Implementation)

[0132] According to the pressure testing agency 101, it can be as follows: Figures 12-15 It is constructed as shown. In Figures 12-15 In, for those through the above Figures 1 to 11 For components that are identical or equivalent to those described, the same reference numerals shall be used and detailed descriptions shall be omitted.

[0133] Similar to the first and second embodiments described above, the first finger member 4 and the second finger member 5 of the robot arm 100 in this embodiment are formed along the workpiece support direction (in... Figure 12 , 13 The first and second finger members 4 and 5 are rod-shaped and extend in an orthogonal direction (left and right). They are designed to move parallel to each other along the workpiece support direction. A pressing force detection mechanism 101 is provided on the second finger member 5 to detect the force of the second finger member 5 pressing on the workpieces 6A and 6B.

[0134] The pressure detection mechanism 101 of this embodiment is configured to be capable of employing Figure 12 The usage patterns shown and Figure 13 The usage pattern shown. Figure 12 The usage configuration shown is one in which a pair of finger members 4 and 5 move in a direction that brings them closer together, thereby supporting the workpiece 6A from the outside. Figure 13 The illustrated usage configuration involves inserting a pair of finger members 4 and 5 into the interior of workpiece 6B and moving them in a direction of separation, thereby supporting workpiece 6B from the inside using the pair of finger members 4 and 5. Workpiece 6A is formed in a cylindrical shape, and workpiece 6B is formed in a cross-section that is approximately door-shaped.

[0135] To enable these two usage configurations, in addition to the first contact member 53, a third contact member 102 is provided in the first hand block 46 of the first finger member 4. The third contact member 102 is fixed in the first hand block 46 in the workpiece support direction (in... Figure 12 The end of the second finger member 5 (in the left-right direction) is opposite to the first contact member 53. In addition, a fourth contact member 103 is provided in the second hand block 47 of the second finger member 5, besides the second contact member 54. The fourth contact member 103 is positioned in the second hand block 47 on the side opposite to the second contact member 54 in the workpiece support direction, and together with the second contact member 54, forms part of the pressing pressure detection mechanism 101 described later.

[0136] The pressure detection mechanism 101 of this embodiment includes a movable member 104 comprising a second contact member 54 and a fourth contact member 103.

[0137] like Figure 14 As shown, the second contact member 54 and the fourth contact member 103 are joined together via two shaft members 56. Similar to the first embodiment, these shaft members 56, arranged in the front-to-back direction, penetrate the second hand block 47 along the workpiece support direction. Figure 14 It is to utilize Figure 12The figure shows a cross-sectional view of the pressure detection mechanism 101 cut through by an imaginary plane and viewed from above, indicated by reference numeral A.

[0138] The second contact member 54 is fixed to one end of the shaft member 56 by screws 64. The fourth contact member 103 is fixed to the other end of the shaft member 56 by screws 105. The fourth contact member 103 has the same structure as the second contact member 54. Figure 12 As shown, the second contact member 54 and the fourth contact member 103 are connected to each other by a connecting member 106 extending along the workpiece support direction.

[0139] like Figure 14 As shown, the pressure detection mechanism 101 of this embodiment is configured by setting the spring member 62 in two parts. Specifically, the spring member 62 of this embodiment is configured in a compressed state between the second contact member 54 and the second hand block 47 and between the fourth contact member 103 and the second hand block 47, respectively. In this case, the second contact member 54 and the fourth contact member 103 function as spring bearing portions 107 and 108 that bear the spring force of the spring member 62, respectively. That is, the movable member 104 has a pair of spring bearing portions 107 and 108 that clamp the second hand block 47 from both sides in the workpiece support direction. On the outer side of the spring bearing portion 107 formed by the second contact member 54, that is, the side opposite to the second hand block 47 (left side), a contact portion 107a formed by a flat surface that contacts the workpiece 6A is formed (see reference). Figure 14 Additionally, a contact portion 108a, which is a flat surface that contacts the workpiece 6B, is formed on the outer side of the spring bearing portion 108, which is the side opposite to the second hand block 47, formed by the fourth contact member 103.

[0140] Two spring members 62 are housed in two recesses 109 formed in the second hand block 47. Hereinafter, the spring member 62 disposed between the second contact member 54 (the spring receiving portion 107 of one side) and the second hand block 47 will be referred to as the first spring member 62A, and the spring member 62 disposed between the fourth contact member 103 (the spring receiving portion 108 of the other side) and the second hand block 47 will be referred to as the second spring member 62B. The first spring member 62A applies force to the second contact member 54 in a direction away from the second hand block 47. The second spring member 62B applies force to the fourth contact member 103 in a direction away from the second hand block 47.

[0141] The movable member 104 is held in place by the spring force of the first spring member 62A and the spring force of the second spring member 62B, preventing it from moving toward the second hand block 47 in the workpiece support direction. The structure in which the first spring member 62A exerts a force on one of the second contact members 54 (one of the spring bearing portions 107) and the second spring member 62B exerts a force on the fourth contact member 103 (the other spring bearing portion 108) constitutes a restriction structure 111 that limits the movement of the movable member 104, which is subjected to the spring forces of these spring members 62, in the workpiece support direction.

[0142] like Figure 15 As shown, the connecting member 106 that connects the second contact member 54 and the fourth contact member 103 is located opposite to the upper surface of the second hand block 47 where the recess 47d is formed. Figure 15 It is to utilize Figure 12 The figure shows a cross-sectional view of the pressure detection mechanism 101 cut by an imaginary plane, indicated by reference numeral B.

[0143] A permanent magnet 68, constituting part of the sensor 41, is provided on the surface of the connecting member 106 opposite to the second hand block 47. Additionally, a Hall element 72, constituting the sensor 41 together with the permanent magnet 68, is provided on the upper surface of the portion of the second hand block 47 where the recess 47d is formed. The Hall element 72 is provided on a substrate 112 fixed to the upper surface of the second hand block 47. It should be noted that the positions of the permanent magnet 68 and the Hall element 72 are not limited to those shown in this embodiment. For example, the Hall element 72 can be provided on the connecting member 106, and the permanent magnet 68 can be provided on the second hand block 47.

[0144] According to the pressure detection mechanism 101 configured in this way, when the first finger member 4 and the second finger member 5 operate to support workpiece 6A or workpiece 6B, one of the second contact member 54 and the fourth contact member 103 contacts workpiece 6A or workpiece 6B, and the pressing pressure when supporting workpieces 6A and 6B is transmitted to workpieces 6A and 6B via the movable member 104. At this time, the movable member 104 moves parallel to the workpiece in a state where the direction of movement is limited by the two shaft members 56 to only the workpiece support direction. Furthermore, by... Figure 14 The neutral position shown overcomes the spring force of the first spring member 62A or the second spring member 62B and moves towards the workpiece support direction (in Figure 14 The movement (left or right) of the movable member 104 causes the sensor 41 to detect a change in value based on the amount of movement. Therefore, according to this embodiment, it is possible to... Figure 12 The pair of finger components 4 and 5 shown are close to each other and hold the workpiece 6A from the outside. Figure 13The shape of the pair of finger components 4 and 5, as shown, being separated from each other and holding the workpiece 6B from the inside, is used to detect the pressing pressure applied to the workpieces 6A and 6B.

[0145] Therefore, even when employing the present invention, a robotic arm can be provided that is unaffected by the deflection of the finger members and can detect accurate gripping force regardless of the contact position with the workpiece. Furthermore, due to its simple structure, manufacturing costs can be kept low. In addition, a sensor 41 can be used to detect the gripping force in both the direction in which the pair of finger members 4 and 5 approach each other and the direction in which they separate.

[0146] (Fourth Implementation)

[0147] According to the pressure testing agency, it can be like Figures 16-18 It is constructed as shown. In Figures 16-18 In China, for those who pass Figures 1 to 15 For components that are identical or equivalent to those described, use the same reference numerals and omit detailed descriptions where appropriate.

[0148] Similarly, as in the third embodiment, Figure 16 The robotic arm 121 shown utilizes a first finger component 4 formed in a rod shape (see reference). Figure 17 The second finger component 5 holds the workpieces 6A and 6B from the outside or inside (refer to...). Figure 12 as well as Figure 13 In this embodiment, a pressure detection mechanism 122 is also provided in the second finger member 5.

[0149] The pressure detection mechanism 122 of this embodiment includes a claw 123 that contacts workpieces 6A and 6B (not shown). The claw 123 has a contacting jaw along the workpiece support direction (in... Figure 16 A plate-shaped workpiece contact portion 123a extending in a direction orthogonal to the left and right directions is mounted to the movable member 125 of the pressure detection mechanism 122 by mounting screws 124. The claw 123 is also mounted to the first hand block 46, which is not equipped with the pressure detection mechanism 122, by mounting screws 124. In this embodiment, the outer shell 2 of the robot 121 is formed to house all of the first and second finger members 4 and 5 and to allow the two claws 123 to protrude. It should be noted that the shape of the workpiece contact portion 123a of the claw 123 is not limited to a plate shape and can be appropriately modified.

[0150] like Figure 17 as well as Figure 18 As shown, unlike the first to third embodiments described above, the pressure detection mechanism 122 in this embodiment has a movable member 125 that is longer in the vertical direction. For example... Figure 18As shown, in this embodiment, the pressure detection mechanism 122 is located on the two shaft members 56 in the vertical direction, which is orthogonal to the workpiece support direction. Figure 18 It is set in the second hand block 47 in the state of being arranged in the vertical direction (also in the middle). Figure 18 It is to utilize Figure 17 The figure shows a cross-sectional view of the pressure detection mechanism 122 cut by an imaginary plane, indicated by reference numeral C.

[0151] A first half 125A of a movable member 125 is fixed to one end (right end) of the two shaft members 56 using a fixing screw 126. A second half 125B of the movable member 125 is fixed to the other end (left end) of the two shaft members 56 using a fixing screw 127. The first half 125A and the second half 125B are respectively formed as plates extending in the vertical and horizontal directions and the front-back direction. A first spring member 62A is provided between the first half 125A and the second hand block 47, applying force to the first half 125A in a rightward direction, away from the second hand block 47. A second spring member 62B is provided between the second half 125B and the second hand block 47, applying force to the second half 125B in a leftward direction, away from the second hand block 47. In this embodiment, the first half 125A constitutes one spring receiving portion 107, and the second half 125B constitutes the other spring receiving portion 108. In addition, in this embodiment, the structure in which the first spring member 62A applies force to the first half 125A and the second spring member 62B applies force to the second half 125B becomes a restriction structure 111 that restricts the movement of the movable member 125, which is subjected to the spring forces of the first and second spring members 62A and 62B, in the workpiece support direction.

[0152] For the first half 125A and the second half 125B, the front ends are connected to each other by a front connecting member 131, and the upper ends are connected to each other by an upper connecting member 132. The aforementioned claw 123 is installed on the front connecting member 131.

[0153] like Figure 18 As shown, a Hall element 72, which forms part of the sensor 41, is provided on the upper connecting member 132. On the other hand, a permanent magnet 68, which together with the Hall element 72 forms the sensor 41, is provided on the upper surface of the second hand block 47, which is opposite to the upper connecting member 132.

[0154] According to the pressure detection mechanism 122 configured in this way, when the first finger member 4 and the second finger member 5 operate to support workpieces 6A and 6B, the claw 123 of the first finger member 4 and the claw 123 of the movable member 125 contact the workpieces 6A and 6B. Furthermore, the pressing force when supporting workpieces 6A and 6B is transmitted to workpieces 6A and 6B via the movable member 125. By pressing workpieces 6A and 6B through the claw 123 of the movable member 125, the movable member 125... Figure 18 The neutral position shown overcomes the spring force of the first spring member 62A or the second spring member 62B and moves towards the workpiece support direction (in). Figure 18 The sensor 41 detects a change in the amount of movement of the movable member 125 as the member moves (either to the left or right). Therefore, the pressure applied to the workpieces 6A and 6B can be detected in both the form in which the pair of claws 123 are close to each other and hold the workpiece 6A from the outside, and in the form in which the pair of claws 123 are separated and hold the workpiece 6B from the inside.

[0155] Therefore, even when employing the present invention, a robotic arm can be provided that is unaffected by the deflection of the finger members and can detect accurate gripping force regardless of the contact position with the workpiece. Furthermore, due to its simple structure, manufacturing costs can be kept low. In addition, a sensor 41 can be used to detect the gripping force in both the direction in which the pair of finger members 4 and 5 approach each other and the direction in which they separate.

[0156] (Fifth Implementation)

[0157] The robotic arm of this invention can, as Figures 19-24 It is constructed as shown. In Figures 19-24 In China, for those who pass Figures 1 to 18 For components that are identical or equivalent to those described, use the same reference numerals and omit detailed descriptions where appropriate.

[0158] Figure 19 The robot arm 200 shown uses three grippers 201 to support the workpiece 6A (see reference). Figure 12 The structure of the robot 200 is as follows: it can hold a workpiece 6A from the outside by moving the three claws 201 toward each other, and it can also hold a cylindrical workpiece (not shown) from the inside by moving the three claws 201 toward each other.

[0159] Three claw plates 201 are installed at Figure 20 The claw plates of the three movable members 202 shown are mounted on the mounting base 203 and move integrally with these movable members 202. For example... Figure 21As shown, in this embodiment, the movable members 202 are movably disposed on the three movement paths 205 formed on the outer casing 204. Figure 19 As shown, the outer shell 204 is formed by a main body 204a and a cover 204b. Figure 21 It is to utilize Figure 20 A partial cross-sectional view of the imaginary plane cutting the robot arm 200, indicated by reference numeral D in the accompanying drawings.

[0160] The three movement paths 205 are arranged to extend radially. In order for the movable member 202 to move along the movement paths 205, the extension direction of each movement path 205 becomes the workpiece support direction. The detailed structure will be described later. The movable member 202 is driven by the drive device 206 provided in the main body 204a of the housing 204 to reciprocate along the movement paths 205.

[0161] like Figure 21 as well as Figure 24 As shown, the drive unit 206 includes a gear housing 210 mounted on one end of the main body 204a, a drive motor 211 mounted on the gear housing 210, first to third rotating shafts 212 to 214 housed in three movement paths 205 and rotatably supported on the main body 204a, and a gear mechanism 215 that connects these first to third rotating shafts 212 to 214 to each other in a linkage manner. The first rotating shaft 212, which is closest to the gear housing 210 among the first to third rotating shafts 212 to 214, protrudes from the main body 204a and extends into the gear housing 210. This first rotating shaft 212 and the output shaft 216 of the drive motor 211 are connected in a linkage manner via first to fifth gears 217 to 221 housed in the gear housing 210.

[0162] The gear mechanism 215 consists of first to third bevel gears 222 to 224 disposed at the shaft ends of the first to third rotating shafts 212 to 214, and a fourth bevel gear 225 meshing with and rotating with these first to third bevel gears 222 to 224. Details are not shown in the figures. The fourth bevel gear 225 is rotatably supported on the cover 204b of the housing 204.

[0163] In this drive device 206, the rotation of the output shaft 216 of the drive motor 211 is transmitted to the first rotating shaft 212 via the first to fifth gears 217 to 221, and the rotation of the first rotating shaft 212 is transmitted to the second rotating shaft 213 and the third rotating shaft 214 via the gear mechanism 215.

[0164] External threads 226 are formed on the outer periphery of the first to third rotating shafts 212 to 214. Figure 24 The external thread 226 shown is drawn with the thread teeth omitted. Figure 22As shown, an internal thread member 227 is screwed into the external thread 226. The internal thread member 227 corresponds to the "finger member" in this invention. In this embodiment, the internal thread member 227 screwed into the first rotating shaft 212 of the three internal thread members 227 corresponds to the finger member for pressure detection.

[0165] Three internally threaded components 227 are respectively connected to the movable component 202 via two shaft components 231. Details will be described later. The shaft components 231 are positioned along the workpiece support direction (in... Figure 22 The state of extension (in the left and right directions) is set on the movable component 202.

[0166] The movable member 202 in this embodiment includes a first half 202A located at the center of the three movement paths 205, and a second half 202B located on the outer side of the three movement paths 205. For example... Figure 23 As shown, the first half 202A and the second half 202B are connected by means of the workpiece support direction (in Figure 23 The bolts 232 extend from the center (in the left and right directions) and are connected to each other. Figure 23 It is to utilize Figure 20 The figure shows a cross-sectional view of the imaginary plane cutting the robot arm 200, indicated by reference numeral E.

[0167] The bolts 232 and the two shaft members 231 described above are combined and positioned in each movable member 202, sandwiching the first to third rotating shafts 212 to 214 and distributed to one side and the other. For example... Figure 22 As shown, for one of the two shaft members 231 (in Figure 22 Regarding the shaft member 231 (located on the lower side), one end is fixed to the first half 202A, and the other end is movably engaged with the bearing member 233 of the internal thread member 227. Regarding the other shaft member 231, one end is fixed to the second half 202B, and the other end is movably engaged with the bearing member 233 of the internal thread member 227.

[0168] A first spring member 234 and a second spring member 235 are provided in the portion where the shaft member 231 is located. One shaft member 231 and the other shaft member 231 pass through the hollow portions of the first spring member 234 and the second spring member 235, respectively. The first spring member 234 is disposed around the one shaft member 231 and the other shaft member 231 and is located between the first half 202A and the internal thread member 227, applying force to the first half 202A in a direction away from the internal thread member 227 (towards the center of the three movement paths 205).

[0169] The second spring member 235 is disposed around one shaft member 231 and the other shaft member 231 and is located between the second half 202B and the internal thread member 227, applying force to the second half 202B in a direction away from the internal thread member 227 (towards the outside of the three movement paths 205). In this embodiment, the first half 202A serves as the spring receiving part of one party, and the second half 202B serves as the spring receiving part of the other party.

[0170] The structure in which the first spring member 234 applies force to the first half 202A and the second spring member 235 applies force to the second half 202B becomes a restriction structure 236 that restricts the movement of the movable member 202, which is subjected to the spring forces of these spring members 234 and 235, in the workpiece support direction.

[0171] like Figure 20 As shown, the movable member 202 is provided with two shaft-shaped rollers 241 extending in a direction orthogonal to the extending direction of the moving passage 205. These shaft-shaped rollers 241 are connected by bearings 242 (see reference). Figure 23 The roller 241 is rotatably supported on the first half 202A and the second half 202B. Furthermore, the roller 241 passes through the movable member 202 and protrudes laterally from the movable member 202, contacting the rolling surface 243 formed on the main body 204a. The rolling surface 243 extends in the same direction as the extension direction of the movement path 205, allowing the roller 241 to roll. In this way, through the contact between the roller 241 and the rolling surface 243, the rotation of the internally threaded member 227 is restricted when the first to third rotation axes 212 to 214 rotate, and the rotation of the first to third rotation axes 212 to 214 is converted into linear motion and transmitted from the internally threaded member 227 to the movable member 202. As a result, the three movable members 202 move synchronously towards the center or outer side of the three movement paths 205.

[0172] like Figure 23 As shown, the movable member 202 that moves on the moving passage 205 provided with the first rotating shaft 212 is provided with a Hall element 72 that constitutes part of the sensor 41.

[0173] In this embodiment, the Hall element 72 is disposed on a substrate 245 that is mounted to the first half 202A and the second half 202B by mounting screws 244. The substrate 245 is a component that moves integrally with the movable member 202. A permanent magnet 68, which together with the Hall element 72 constitutes the sensor 41, is disposed at a position in the internally threaded member 227 opposite to the Hall element 72. It should be noted that the positions of the Hall element 72 and the permanent magnet 68 are not limited to the positions in this embodiment. For example, the Hall element 72 can be disposed on the internally threaded member 227, and the permanent magnet 68 can be disposed on a component that moves integrally with the movable member 202.

[0174] In this embodiment, the pressure detection mechanism 246 is composed of a movable component 202 driven by the first rotating shaft 212, an internal thread component 227, a shaft component 231, first and second spring components 234 and 235, and a sensor 41.

[0175] In the robot arm 200 of this embodiment, by moving the three movable members 202 in a manner close to each other, the three claws 201 can grasp the workpiece 6A from the outside. Alternatively, by moving the three movable members 202 in a direction separating them, the three claws 201 can grasp a cylindrical workpiece (not shown) by pressing from the inside out. When grasping the workpiece 6A or the cylindrical workpiece, the pressing force used to support the workpiece 6A or the cylindrical workpiece is transmitted to the workpiece 6A or the cylindrical workpiece via the movable members 202. Furthermore, at this time, the movable members 202 move relative to the internal thread member 227 against the spring force of the first spring member 234 or the second spring member 235, and the detection value of the sensor 41 changes according to the amount of movement of the movable members 202.

[0176] Therefore, the pressing pressure applied to the workpiece 6A and the cylindrical workpiece can be detected in both the form in which a set of claws 201 approach each other and hold the workpiece 6A from the outside, and in the form in which a set of claws 201 separate from each other and hold the cylindrical workpiece from the inside.

[0177] Therefore, even when employing the present invention, a robotic arm can be provided that is unaffected by the deflection of the finger components and can detect accurate gripping force regardless of the contact position with the workpiece. Furthermore, due to its simple structure, manufacturing costs can be kept low. Additionally, a single sensor 41 can be used to detect the gripping force in both the direction in which the set of claws 201 approach each other and the direction in which they separate.

[0178] (Sixth and Seventh Implementation Methods)

[0179] The robotic arm of this invention can, as Figure 25 as well as Figure 26 It is constructed as shown. In Figure 25 as well as Figure 26 In China, for those who pass Figures 1 to 24 For components that are identical or equivalent to those described, use the same reference numerals and omit detailed descriptions where appropriate.

[0180] Figure 25The robot arm 300 shown in the sixth embodiment replaces the claw 201 of the robot arm 200 in the fifth embodiment and has the first and second finger members 4 and 5 shown in the first or second embodiment. The robot arm 300 has two first finger members 4 and one second finger member 5 (finger member for pressure detection) with a pressure detection mechanism 7.

[0181] Figure 26 The robotic arm 400 shown in the seventh embodiment replaces the claw 201 of the robotic arm 200 in the fifth embodiment and has the first and second finger members 4 and 5 shown in the third embodiment. The robotic arm 300 has two first finger members 4 and one second finger member 5 (a finger member for pressure detection) with a pressure detection mechanism 101.

[0182] Similar to the robot 200 of the fifth embodiment, the first and second finger members 4 and 5 of the robot 300 and robot 400 are movably arranged in three radially extending movement paths 205 such that the extension direction of each movement path 205 is the workpiece support direction. These three movement paths 205 are equipped with a drive device 206 that synchronously moves all finger members 4 and 5 toward the center or outer side of the three movement paths 205.

[0183] Figure 25 The first and second finger members 4 and 5 of the robot 300 shown are mounted such that the direction toward the center of the three movement paths 205 is the workpiece support direction. Furthermore, the robot 300 is configured to change the mounting direction of the first and second finger members 4 and 5 such that the direction toward the outer side of the three movement paths 205 is the workpiece support direction.

[0184] In the sixth and seventh embodiments, a robotic arm can also be provided that is unaffected by the deflection of the finger members and can detect accurate gripping force regardless of the contact position with the workpiece. Furthermore, due to its simple structure, manufacturing costs can be kept low. In addition, a sensor 41 can be used to detect the gripping force in both the direction in which the two first finger members 4 and the second finger member 5 approach each other and the direction in which they separate.

Claims

1. A robotic arm, characterized in that, The robotic arm has the following features: Multiple finger components that press and support the workpiece by moving along the workpiece support direction that allows them to approach or separate from each other; and According to the pressure detection mechanism, at least one of the plurality of finger components is the finger component used for pressure detection. The pressure detection mechanism includes: A movable member is supported on the finger member for pressing pressure detection via a shaft member extending in the workpiece support direction, and transmits the pressing pressure when supporting the workpiece. A spring member that applies a force to the movable member in the direction supporting the workpiece; A limiting structure that restricts the movement of the movable member, which is subjected to the spring force of the spring member, in the direction of supporting the workpiece. as well as The sensor detects a change in value based on the amount of movement of the movable member relative to the pressure-detecting finger member as it overcomes the spring force of the spring member. The finger member is formed as a rod extending in a direction orthogonal to the workpiece support direction. The shaft members are respectively disposed at multiple positions in the finger members used for pressure detection, in a direction orthogonal to the workpiece support direction, and respectively penetrate the finger members. The movable member is formed as a plate extending along the direction in which the plurality of shaft members are arranged, and in a state where the movable member is arranged along the workpiece support direction on the side opposite to the finger member for pressure detection, both ends of the movable member in the direction in which the plurality of shaft members are arranged are fixed to one end of the shaft member. The limiting structure includes a stop member that is integrally and movably mounted to the other end of the shaft member and is positioned opposite the finger member used for pressure detection. The spring member applies force to the portion between the plurality of shaft members in the movable member.

2. The robotic arm according to claim 1, characterized in that, The spring member has a structure that applies force to the central portion of the plurality of shaft members of the movable member in the direction of their arrangement.

3. The robotic arm according to claim 1, characterized in that, A screw component is screwed onto the stop member, and the screw component contacts the other side of the pressure detection finger component located on the opposite side of the workpiece. The distance between the movable member and the finger member used for pressure detection is adjusted by changing the screw depth of the screw member.

4. The robotic arm according to claim 1, characterized in that, The plurality of finger components are movably arranged in three radially extending moving paths such that the extending direction of each moving path is the workpiece support direction. One of the three finger components is the finger component used for pressure detection. The three moving paths are equipped with driving devices, which cause all finger components to move synchronously toward the center or the outside of the three moving paths.

5. The robotic arm according to claim 1, characterized in that, The sensor consists of a permanent magnet and a Hall element for detecting the magnetic field of the permanent magnet. The stop member is a component that moves integrally with the movable member, and has an extension extending along the outer surface of the finger member used for pressing pressure detection in a direction orthogonal to the workpiece support direction. A component of one of the permanent magnet and the Hall element is mounted on the outer surface of the finger component for pressure detection, and a component of the other is mounted on the extension of the stop component.

6. A robotic arm, characterized in that, The robotic arm has the following features: Multiple finger components that press and support the workpiece by moving along the workpiece support direction that allows them to approach or separate from each other; and According to the pressure detection mechanism, at least one of the plurality of finger components is the finger component used for pressure detection. The pressure detection mechanism includes: A movable member is supported on the finger member for pressing pressure detection via a shaft member extending in the workpiece support direction, and transmits the pressing pressure when supporting the workpiece. A spring member that applies a force to the movable member in the direction supporting the workpiece; A limiting structure that restricts the movement of the movable member, which is subjected to the spring force of the spring member, in the direction of supporting the workpiece. as well as The sensor detects a change in value based on the amount of movement of the movable member relative to the pressure-detecting finger member as it overcomes the spring force of the spring member. The shaft member passes through the finger member used for pressing pressure detection along the workpiece support direction. The movable member has a pair of spring-supporting parts that clamp the pressure-detecting finger member from both sides in the workpiece support direction. The spring component includes: A first spring member is disposed between the finger member for pressing pressure detection and one of the spring receiving portions, and applies force to the spring receiving portion of one of the springs in a direction away from the finger member; as well as A second spring member is disposed between the pressure detection finger member and the other spring receiving part, and applies force to the other spring receiving part in a direction away from the finger member. The limiting structure is constructed using the pressure detection finger member, one of the spring bearing parts, and the other of the spring bearing parts.

7. The robotic arm according to claim 6, characterized in that, The finger member is formed as a rod extending in a direction orthogonal to the workpiece support direction. The two finger components are designed to move parallel to each other along the workpiece support direction. One of the two finger components is the finger component used for pressure detection. The spring bearing portion has a contact portion, which is disposed at both ends of the movable member in the workpiece support direction and contacts the workpiece.

8. The robotic arm according to claim 6, characterized in that, The finger member is formed as a rod extending in a direction orthogonal to the workpiece support direction. The two finger components are designed to move parallel to each other along the workpiece support direction. One of the two finger components is the finger component used for pressure detection. The movable member and the other finger member of the two finger members are respectively provided with claws that contact the workpiece.

9. The robotic arm according to claim 6, characterized in that, The plurality of finger components are movably arranged in three radially extending moving paths such that the extending direction of each moving path is the workpiece support direction. One of the three finger components is the finger component used for pressure detection. The spring bearing portion has a contact portion, which is disposed at both ends of the movable member in the workpiece support direction and contacts the workpiece. The three moving paths are equipped with driving devices, which cause all finger components to move synchronously toward the center or the outside of the three moving paths.

10. The robotic arm according to claim 6, characterized in that, The plurality of finger components are movably arranged in three radially extending moving paths such that the extending direction of each moving path is the workpiece support direction. One of the three finger components is the finger component used for pressure detection. The movable member and other finger members (not the one used for pressure detection) are respectively provided with claws that contact the workpiece. The three moving paths are equipped with driving devices, which cause all finger components to move synchronously toward the center or the outside of the three moving paths.

11. The robotic arm according to any one of claims 1 to 10, characterized in that, The sensor consists of a permanent magnet and a Hall element for detecting the magnetic field of the permanent magnet. A component of one of the permanent magnet and the Hall element is disposed on the finger component for pressure detection, and a component of the other is disposed on a component that moves integrally with the movable component.

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