End effectors and manipulators

Abstract

To provide an end effector with improved operability, which is suitable for being down-sized.SOLUTION: An end effector of the present invention includes: a fixed member having a first communication part and a second communication part each communicating a proximal end side and a distal end side, in which the proximal end side is fixed to a tip of a manipulator; an elastic member that passes from the proximal end side to the distal end side through the first communication part; a wire that passes from the distal end side to the proximal end side through the second communication part; and a movable member having a guide part for disposing the elastic member and the wire at an acute angle, which is connected to the distal end side of the fixed member through the elastic member and the wire. The movable member rotates to a first rotation state by applying tensile force toward the proximal end side to the wire in the second communication part. In the first rotation state, the elastic member is bent at a predetermined position between the first communication part and the guide part. When the tensile force is released, the movable member rotates to a second rotation state by elastic force to the bending of the elastic member at a predetermined position.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to an end effector and a manipulator using the end effector.

Background Art

[0002] Retinal surgery is one of the difficult surgical procedures performed by surgeons who have acquired advanced surgical skills. In retinal surgery, it is necessary to work using instruments in a narrow and limited intraocular space. Therefore, in order to assist retinal surgery, many robotic forceps with various end effectors and tools attached to the tip of the shaft have been developed. General robotic forceps are designed to mount an end effector or tool at the tip of a straight and rigid shaft, and the work in the intraocular space is limited. Typical end effectors or tools used in retinal surgery include, for example, needles, light pipes, pipettes, and grippers.

[0003] In order to enable higher degrees of freedom in operability in the intraocular space, robotic forceps designed such that the tip portion of the shaft is curved have been researched and developed (Non-Patent Documents 1 to 3). According to these robotic forceps, when accessing the front part of the retina to perform surgery such as retinal detachment, it is possible to appropriately access the target on the retina from an appropriate direction.

Prior Art Documents

Non-Patent Documents

[0004]

Non-Patent Document 1

Non-Patent Document 2

[0005] Robotic forceps used in procedures such as retinal surgery require shafts with a diameter of less than 1 mm, making it difficult to realize end effectors on such a sub-millimeter scale. In particular, realizing grippers that grasp and release objects on such a sub-millimeter scale has been challenging. For example, the opening and closing mechanism of grippers in robotic forceps used in general laparoscopic surgery uses link mechanisms or wire-pulley mechanisms composed of multiple links and hinges. However, using such link mechanisms or wire-pulley mechanisms in sub-millimeter scale grippers is virtually impossible from the standpoint of strength and assembly.

[0006] A conventional type of gripper for ophthalmic forceps is the elastic deformable gripper. In a conventional elastic deformable gripper, as shown in Figure 9(a), the gripper is opened and closed by sliding the elastic member 902 that forms the gripper relative to the outer tube 901. However, this conventional gripper has the following problems. First, when sliding the elastic member 902 or the outer tube 901 to open and close the gripper, a relatively long straight stroke 903 or stroke 905 is required (Figures 9(b), (c)). Because a long stroke is required to open and close the gripper, the tip side of the bending mechanism becomes longer, reducing the operating range of the gripper within the eyeball and decreasing operability. Also, when opening and closing the gripper by moving the elastic member 902, a displacement 904 occurs in the gripper's gripping position (Figure 9(c)). When such a displacement occurs, it is not possible to accurately grasp the target object. Furthermore, because the jaw portion of the gripper is closed by elastic bending, the gripping force obtained is small. Furthermore, it is difficult to apply this to robotic forceps equipped with a bending mechanism, as proposed in Non-Patent Documents 1-3.

[0007] The present invention provides an end effector that is suitable for miniaturization and has improved operability. [Means for solving the problem]

[0008] An end effector according to one aspect of the present invention has the following configuration: An end effector that is attached to the tip of a manipulator, Each has a first and second communication portion that connects the proximal end and the distal end, and the proximal end is fixed to the tip of the manipulator as a fixing member, One or more elastic members passing through the first communication portion and extending from the proximal end to the distal end, A wire passing through the second communication section and exiting from the distal end to the proximal end, It has guide means for arranging the elastic member and the wire at an acute angle, and includes a movable member connected to the distal end side of the fixed member via the elastic member and the wire. The movable member rotates to a first rotation state by applying a tensile force toward the proximal end side to the wire in the second communication portion, and in the first rotation state, the elastic member is bent at a predetermined position between the first communication portion and the guide means. When the tensile force is released, the movable member rotates to a second rotation state by the elastic force against the bending of the elastic member at the predetermined position.

Advantages of the Invention

[0009] According to the present invention, it is possible to provide an end effector suitable for miniaturization and having improved operability.

Brief Description of the Drawings

[0010] [Figure 1] It is a view showing the appearance of a robotic gripper according to an embodiment. [Figure 2] It is a view for explaining the bending mechanism of the robotic gripper. [Figure 3] It is a view for explaining the structure of the gripper portion of the robotic gripper. [Figure 4] It is a view for explaining the operation of the gripper portion. [Figure 5] It is a view showing an operating mechanism for driving the gripper portion. [Figure 6] It is a view showing another example of the operating mechanism for driving the gripper portion. [Figure 7] It is a view showing an example of constituting the gripper portion by two movable members. [Figure 8] It is a view showing a modified example of the end effector. [Figure 9] It is a view for explaining the gripper of a conventional ophthalmic forceps.

Modes for Carrying Out the Invention

[0011] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the invention according to the claims, and not all combinations of the features described in the embodiments are essential to the invention. Two or more of the features described in the embodiments may be arbitrarily combined. Also, the same or similar configurations are assigned the same reference numerals, and redundant descriptions are omitted.

[0012] FIG. 1 is a diagram showing an external appearance example of a robotic gripper according to this embodiment. The robotic gripper 10 is an example of a manipulator, and in this embodiment, it is composed of a working unit 11 and a hand unit 12. Further, a gripper unit 100, which is an example of an end effector, is attached to the tip of the working unit 11.

[0013] FIG. 1(a) shows a state where the working unit 11 and the hand unit 12 are separated, and FIG. 1(b) shows a state where the working unit 11 and the hand unit 12 are connected. The working unit 11 has a unit base 130, a shaft 140, a bending mechanism 120, and a gripper unit 100. The shaft 140 has a hollow structure, one end of which is connected to the unit base 130, and the other end is connected to the bending mechanism 120. Further, a gripper unit 100, which is an example of an end effector, is connected and fixed to the tip of the bending mechanism 120. The hand unit 12 has a main body 200 for the user to grip, and a ratchet lever 201 for connecting the hand unit 12 and the working unit 11 and maintaining that state is provided on the main body 200. When the ratchet lever 201 fits into the ratchet fitting portion 131 (FIGS. 5(a)(b)) of the working unit 11, the hand unit 12 and the working unit 11 are connected and that state is maintained.

[0014] Figure 2 shows an example of the external appearance and a detailed configuration of the bending mechanism 120. The bending mechanism 120 has a bending section 123 formed by stacking a plurality of disc members 124. A first bending wire 125 is passed through holes 127a and 127b of the stacked disc members 124. A second bending wire 126 is passed through holes 127c and 127d. By manipulating the first bending wire 125 and the second bending wire 126, the bending mechanism 120 can be bent in any direction. The hole 127e provided in the center of the disc member 124 is a hole through which a wire (described later) for driving the gripper section 100 to open and close is passed. The member (first end 121) provided on the distal end side of the bending section 123 has a protrusion for connecting the bending mechanism 120 and the gripper section 100 and for fitting into a recess 104 (described later in Figure 3) of the gripper section 100. Furthermore, the member (second end portion 122) provided on the proximal end side of the curved portion 123 has a protrusion for connecting the bending mechanism 120 and the shaft 140 and for fitting into the hollow portion of the shaft 140.

[0015] Figure 3 shows an example of the external appearance of the gripper section 100 when disassembled into its individual components. The gripper section 100 shown in Figure 3 consists of a fixed member 101, a movable member 102, and a wire 103. The wire 103 is an elastic wire with elasticity against bending, and for example, a nitinol wire with superelastic properties (memory material in a straight state) can be used. In the prototype of this embodiment, a 0.125 mm diameter Ni-Ti alloy (KIOKALLOY-R) available from Daido Steel Co., Ltd. was used to accommodate the size required for a manipulator for ophthalmic surgery (for example, a shaft 140 with a diameter of 0.9 mm is used). However, this is merely an example, and it goes without saying that the size and properties of the wire 103 are not limited. For example, a nitinol wire with a diameter of about 0.08 to 0.18 mm can be suitably used. The fixing member 101 has a recess 104 into which the protrusion of the first end 121 of the bending mechanism 120 is fitted, and a jaw portion 105a that functions as one of the jaws of the gripper. The fixing member 101 also has a first communication portion 111 and a second communication portion 112 that connect the distal end and the proximal end. The wire 103 is arranged to pass through the first communication portion 111 from the proximal end to the distal end of the fixing member 101, and then return through the second communication portion 112 from the distal end to the proximal end of the fixing member 101.

[0016] The movable member 102 has a jaw portion 105b that functions as the other jaw of the gripper. By rotating the movable member 102, the jaw portion 105a of the fixed member 101 and the jaw portion 105b of the movable member 102 open and close. The movable member 102 has wire passages 113 to 114 for passing the wire 103. The wire passages 113 to 114 function as guide portions that guide the wire 103 toward the first communication portion 111 and the second communication portion 112 by bending the wire 103 at an acute angle at the distal end of the fixed member 101 (as will be described later with reference to Figure 4). In the prototype, as described above, a wire 103 with a diameter of 0.125 mm was used, and the holes (first communication section 111, second communication section 112, wire passages 113-114) provided in the fixed member 101 and movable member 102 for the wire 103 to pass through were set to a diameter of 0.15 mm. Of course, these dimensions are not limited to these, but when applied to sub-millimeter to millimeter-order manipulators for microsurgery, for example, it is desirable that the wire diameter be in the range of 0.125 mm ± 0.055 mm (0.08-0.18 mm) and the hole diameter be in the range of 0.09-0.22 mm.

[0017] The first end 121 of the bending mechanism 120 is fitted into a recess 104 formed in the fixing member 101, thereby fixing the bending mechanism 120 and the fixing member 101. The first end 121 is provided with a groove 128, and when the first end 121 is fitted into the recess 104, the groove 128 and the inner surface of the recess 104 form a cylindrical hole that connects to the first communication portion 111. One end of the wire 103 is fixed to this cylindrical hole. With the first end 121 fixed to the fixing member 101, the groove 128 and the first communication portion 111 are aligned coaxially, and the wire 103, whose end is fixed in the groove 128, passes through the first communication portion 111 and exits to the distal end side of the fixing member 101. The wire 103 is bent at an acute angle by the guide section having wire passages 113-114, and then exits through the second communication section 112 to the proximal end of the fixing member 101. With the first end 121 fixed to the fixing member 101, the wire passage 129 of the first end 121 and the second communication section 112 are coaxially aligned, and the wire 103 that has exited the second communication section 112 exits through the hole 127e of the bending mechanism 120 to the hollow part of the shaft 140.

[0018] By attaching the recess 104 (cylindrical hole) of the fixing member 101 to the side surface (cylindrical surface) of the first end portion 121, the gripper portion 100 gains resistance to the action of bending moment 302. Furthermore, by inserting the end of the wire 103 into the cylindrical hole formed by the groove 128 of the first end portion 121 and the inner surface of the recess 104, the gripper portion 100 gains resistance to the action of torsional moment 301.

[0019] Figure 4 is a cross-sectional view of a gripper section 100 as an example of an end effector. In the gripper section 100, a movable member 102 is rotatably connected to a fixed member 101 via a wire 103, and the opening and closing of the gripper jaws is achieved by the rotation of the movable member 102. As shown in Figure 4(a), one end of the wire 103 is fixed at a fixed position 401. Possible fixing methods include crimping, bonding, and welding. However, because the wire 103 is bent at an acute angle by the folded portion 402, no force is applied to the wire 103 in the direction of pulling it out of the first communication portion 111. Therefore, even without actively fixing the wire 103, it is possible to maintain the gripper function by simply inserting it into the cylindrical hole formed by the inner surface of the groove portion 128 and the recess 104. The wire 103, having passed through the first communication section 111 to the distal end of the fixing member 101, is bent at an acute angle at the return section 402 by the guide section formed by the wire passage 113 and the wire passage 114. The wire 103, bent at an acute angle at the return section 402, passes through the wire passage 114 towards the second communication section 112, and returns to the proximal end of the fixing member 101 by passing through the second communication section 112.

[0020] When an axial tensile force (force in the direction of arrow 421) acts on the portion of the wire 103 passing through the second communication portion 112, the movable member 102 rotates relative to the fixed member 101 in the direction of arrow 422, resulting in the state shown in Figure 4(b) (hereinafter referred to as the first rotation state). In this first rotation state, the wire passage 114 and the second communication portion 112 are aligned coaxially, and the wire 103 is in a nearly straight line. In this embodiment, the axis of the second communication portion 112 is positioned to coincide with the central axis of the shaft 140, but it is not limited to this. The axis of the second communication portion 112 and the central axis of the shaft 140 may be misaligned.

[0021] As the wire 103 is pulled in the direction of arrow 421 by the tensile force, the jaws 105a and 105b of the gripper part 100 remain closed while the movable member 102 is in the first rotational state. The gripping force of the gripper part 100 at this time can be calculated from the balance of moments around the predetermined position 403, and it has been found that a gripping force roughly proportional to the tensile force of the wire 103 can be obtained. The fixed member 101 and the movable member 102 are configured such that the wire 103 bends at one point (predetermined position 403) between the first communication part 111 and the entrance of the guide part (entrance of the wire passage 113) in the first rotational state. As described above, the wire passage 114 and the second communication part 112 are arranged coaxially when the movable member 102 is in the first rotational state, and the wire 103 extends in a straight line. The portion of the wire 103 at the predetermined position 403 functions as a hinge that rotates the movable member 102 relative to the fixed member 101, and the movable member 102 rotates about an axis perpendicular to the longitudinal direction of the wire 103. The bending of the wire 103 at the predetermined position 403 is within the elastic limit of the wire 103. Alternatively, if the wire 103 is a superelastic wire, it is within the superelastic limit that returns it to its initial state due to its superelastic properties when the load is released. Therefore, in the first rotation state, the movable member 102 is biased by the elastic force of the wire 103 in the direction that the wire 103 extends linearly.

[0022] When the wire 103 is released from the tensile force (force in the direction of arrow 421), the elastic force against bending of the wire 103 causes the portion of the wire 103 at the predetermined position 403 to extend in a straight line. As a result, the movable member 102 rotates to the state shown in Figure 4(a) (hereinafter referred to as the second rotation state). In the second rotation state, the first communication section and the wire passage 113 are aligned coaxially, the wire 103 extends in a straight line at the predetermined position 403, and the jaws 105a and 105b of the gripper section 100 are open. Note that the magnitude of the bend of the wire 103 at the predetermined position 403 in the first rotation state is greater than the magnitude of the bend of the wire 103 between the folded section 402 and the second communication section 112 (between position 404 and position 405) in the second rotation state. This allows the movable member 102a to rotate sufficiently due to the elastic force of the wire 103 at the predetermined position 403, and a sufficient gripper opening angle can be obtained. Alternatively, a superelastic wire 103 may be used that is deformed to bend near position 404 in the initial state without tension, as shown in Figure 4(a), or deformed to bend outward near position 403 in the initial state. By using such a wire 103, the opening angle of the movable member 102 (gripper) shown in Figure 4(a), or a larger opening angle, can be more reliably obtained when there is no tension in the direction of arrow 421. Furthermore, if the device is equipped with a function to push the wire 103 from the base end (a function to apply force to the wire 103 in the opposite direction to arrow 421), and if the wire 103 is fixed to the fixed member 101 near position 401 to prevent the movable member 102 (gripper) from coming off, then the opening angle of the movable member 102 (gripper) as shown in Figure 4(a), or a larger opening angle, can be obtained more reliably.

[0023] Next, we will explain the magnitude of the stroke of the wire 103 required to close the gripper portion 100. As shown in Figures 4(a) and 4(b), the amount of rotation of the movable member 102 required to transition from the second rotation state to the first rotation state is an angle θ. G This means that the movable member 102 is at an angle θ. GWhen rotated by only this much, the length of the wire 103 from the second connecting portion 112 to the folded portion 402 is as shown in Figure 4(a) L w (Distance between position 404 and position 405) is shown in Figure 4(b) wi It changes to the length L. That is, the wire 103 is changed to length L. N =L w -L wi By moving it by only that much, the movable member 102 is moved to an angle θ G It can be rotated. Therefore, it can be seen that the gripper can be opened and closed with a very small amount of movement (stroke).

[0024] An example of an operating mechanism that utilizes the characteristic described above, which allows the gripper portion 100 to be opened and closed with a small amount of manipulation on the wire 103, is provided.

[0025] Figure 5 illustrates an example of an operating mechanism for opening and closing the gripper portion 100 by the robotic forceps 10 of the embodiment. As described in Figure 1, the hand unit 12 and the work unit 11 are connected by a ratchet mechanism having a ratchet lever 201 and a ratchet fitting portion 131. The mechanism for driving the first bending wire 125 and the second bending wire 126 for bending the bending mechanism 120 at the tip of the shaft 140 is as described in Non-Patent Documents 1 to 3, for example, and a detailed explanation and illustration are omitted. In Figure 5, a cross-sectional view shows the state in which the hand unit 12 and the work unit 11 are connected by the ratchet mechanism. The ratchet lever 201 is biased by a spring 212a to maintain the state in which the work unit 11 and the hand unit 12 are connected. The work unit 11 has a rod member 215 having a hole 217 for passing a wire 103 and a wire fixing portion 216 for fixing the wire 103 to the unit base 130. The rod member 215 is connected to a link member 214 which has a recess formed to accommodate the tip of the operating lever 211.

[0026] With the work unit 11 and the hand unit 12 connected by a ratchet mechanism, as shown in Figure 5(a), one end (first end) of the operating lever 211 provided on the hand unit 12 engages with a recess in the link member 214. The other end (second end) of the operating lever 211 is pushed upward in the figure by a spring 212b, providing an operating part for the user to operate. In the state shown in Figure 5(a), the hole 217 provided in the rod member 215, the hollow portion of the shaft 140, and the wire fixing portion 216 are aligned coaxially, and the wire 103 extends in a straight line.

[0027] When the user pushes down the second end (operating part) of the operating lever 211 against the biasing force of the spring 212b, the operating lever 211 rotates around the pivot point 213. As a result, as shown in Figure 5(b), the first end of the operating lever 211 moves upward in the figure, causing the link member 214 and the rod member 215 connected thereto to move upward. The movement of the rod member 215 causes the hole 217 to move from its coaxial position with the shaft 140 and the wire fixing part 216, applying an upward pulling force to a portion of the linearly extending wire 103. As a result, a force in the direction of arrow 501 (i.e., a tensile force at the second communication part 112) is applied to the wire 103, and the gripper part 100 closes. When the pressure on the second end of the operating lever 211 is removed, the biasing force of the spring 212b causes the operating lever 211 to return to the state shown in Figure 5(a). In other words, the hole 217, the hollow portion of the shaft 140, and the wire fixing portion 216 are aligned coaxially, the tensile force applied to the wire 103 in the direction of arrow 501 disappears, and the gripper portion 100 opens (Figure 5(a)). As described above, since the gripper portion 100 can be opened and closed with a small stroke of the wire 103, the gripper can be opened and closed by an operating mechanism that moves a part of the wire 103 away from the axial direction. As a result, a gripper that opens and closes quickly in response to user operation can be provided. In addition, by adding a ratchet function to the operating lever 211, it becomes easier to maintain the gripper in the closed state, improving operability depending on the work and technique. Furthermore, in this embodiment, the gripper is normally in the open state, but by arranging the spring 212 and the pressing portion distal to the fulcrum 213, it is also possible to keep the gripper in the closed state under normal circumstances.

[0028] Figure 6 illustrates another example of a mechanism for opening and closing the gripper portion 100 according to an embodiment. The robotic forceps 10a comprises a hand unit 12a and a work unit 11a. In the work unit 11a, the gripper portion 100 and the shaft 140 are connected via a connecting member 640, and the shaft 140 is connected to the unit base 130a. In the robotic forceps 10a shown in Figure 6, the connecting member 640 is used instead of the bending mechanism 120 described above. In addition, the robotic forceps 10a has a first base 601 that is rotatable relative to the second base 602, and the gripper portion 100 can be rotated by rotating the first base 601 (described later). The proximal end of the connecting member 640 has a cylindrical shape with a diameter that fits into the hollow portion of the shaft 140. The distal end of the connecting member 640 is similar to the portion that fits into the recess 104 of the first end portion 121.

[0029] The unit base 130a has a first base 601 and a second base 602 that are rotatably connected. At the point where the first base 601 and the second base 602 are connected, the first base 601 has a cylindrical recess and the second base 602 has a cylindrical protrusion. Bearings 611a and 611b are positioned between the inner surface of the recess of the first base 601 and the side surface of the second base 602, with a spacer 621 positioned between them. The first base 601 is supported by press-fitting or the like to prevent it from coming out of the second base 602, and the first base 601 is rotatably connected to the second base 602. The second base 602 is connected to the main body 200a of the hand unit 12a. As a result, the distal end components connected to the first base 601 (shaft 140, connecting member 640, gripper portion 100) can rotate around the axis of the shaft 140 relative to the second base 602 (and the main body 200a). For example, a user can rotate the gripper portion 100 by rotating the first base 601 with their index finger while gripping the main body 200a. In this example, the axis of the shaft 140 and the axis of rotation of the first base 601 are coaxial. Furthermore, the method of supporting the gripper portion 100 so that it can rotate relative to the main body 200a is not limited to the above configuration. In addition, the above configuration, which enables the rotation of the gripper portion 100 by the first base 601, can also be applied when a bending mechanism 120 is provided between the shaft 140 and the gripper portion 100.

[0030] The second base 602 is provided with a rod member 622 that is slidable in the direction of arrow 631. The rod member 622 has a hole 623 for passing the wire 103 through, and the portion exposed from the second base provides an operating part for user operation. After passing through the hole 623, the wire 103 passes through a hole 624 provided at the bottom of the second base 602 and is fixed to a retaining member 625 to prevent it from coming out of the hole 624. By pushing the rod member 622 in the direction of arrow 632, the position of the hole 623 changes, and as shown in Figure 6(b), an operating force is applied to the wire 103 in the direction of arrow 632. As a result, a force is applied to the wire 103 in the direction of arrow 633, and the gripper portion 100 closes.

[0031] When the rod member 622 is released from the compressed state, the wire 103 returns to a straight shape due to its elastic force, acting to return the space between holes 623 and 624 to a straight line. As a result, the rod member 622 moves in the opposite direction to arrow 632, returning to the state shown in Figure 6(a) where the hollow portion of the shaft 140, holes 623 and 624 are coaxially aligned. Also, the force (tensile force) in the direction of arrow 633 disappears, and the gripper portion 100 becomes open. Note that the rod member 622 is returned by the elastic force of the wire 103, but this is not the only configuration. For example, the rod member 622 may be biased in the opposite direction to arrow 632 by a spring or the like. Also, when no force is applied in the direction of arrow 632, the shaft 140, the rotation axis of the first base 601, the hole 623 of the rod member 622, and the hole 624 at the bottom of the second base 602 are coaxially aligned. Furthermore, the stopper member 625 that secures the wire 103 is not fixed to the second base 602. Therefore, in the state shown in Figure 6(a) where the rod member 622 is not being pressed, the user can rotate the first base 601 relative to the second base 602. Since the stopper member 625 is not fixed to the second base 602, the wire 103 does not twist even when the first base 601 is rotated relative to the second base 602. By making the first base 601 rotatable relative to the second base 602 in this way, the gripper portion 100 and the shaft 140 can be rotated around the main body 200a with the longitudinal axis as the axis, improving usability. If the length of the wire 103 can be sufficiently secured and twisting of the wire 103 is tolerable, the wire 103 may be fixed to the base end of the second base 602, etc. This reduces the number of parts and improves ease of assembly.

[0032] Other Embodiments In the above example, the fixed member 101 functions as one jaw of the gripper and the movable member 102 functions as the other jaw of the gripper, but this is not the only example. Multiple movable members 102 may be provided. For example, as shown in Figure 7, two sets of movable members 102 and wires 103 may be used to configure the two jaws of the gripper section 100a with two movable members 102a and 102b. In this case, the fixed member 101a is provided with two sets of first connecting parts 111 and second connecting parts 112 corresponding to the two wires 103a and 103b. When force is applied to wires 103a and 103b in the directions of arrows 421a and 421b, the movable members 102a and 102b enter a first rotational state, and the gripper section 100a closes (Figure 7(b)). When the forces indicated by arrows 421a and 421b are released, the elastic forces of wires 103a and 103b cause the movable members 102a and 102b to enter a second rotational state, and the gripper portion 100a opens (Figure 7(a)). Although a second communication portion is provided individually for each of wires 103a and 103b, the second communication portion may be shared by wires 103a and 103b.

[0033] As described above, the end effector (gripper) of the above embodiment allows the movable part to be moved with a small amount of operation, improving operability. In addition, the end effector of the above embodiment closes due to the force of pulling the wire 103, so sufficient gripping force can be obtained. Furthermore, the end effector of the above embodiment can be realized with a small number of parts, namely a fixed member 101 and a movable member 102, making it excellent for miniaturization. In addition, with the manipulator of the above embodiment, the user's operating direction for opening and closing the gripper is substantially perpendicular to the axial direction of the shaft 140. Thus, compared to the operation described in Figure 9, the operating direction is closer to the opening and closing direction of the gripper, enabling more intuitive operation. Furthermore, since the tip position of the gripper does not move when the gripper is opened and closed, operability is improved. In addition, the wire 103 that drives the movable member 102 of the end effector of this embodiment does not need to be moved back and forth in the hollow part of the shaft 140, making it suitable for mounting on a manipulator equipped with a bending mechanism 120. In the above embodiment, a gripper was used as an example of an end effector, but it is not limited to a gripper; any end effector with opening / closing or bending functions, such as scissors or clip applicators, is acceptable.

[0034] Furthermore, in the above embodiment, the gripper drive mechanism was described as a mechanism for an operator to directly operate the manipulator, but it is not limited to this. For example, it is clear that the end effector of the present invention can also be applied to remotely operated manipulators and automated manipulators. For example, when applying the work unit 11 shown in Figure 1 to a remotely operated manipulator, a drive mechanism for motor-driving the bending mechanism 120 and a drive mechanism for motor-driving the gripper section 100 are mounted on the main body 200. The drive mechanism for the bending mechanism 120 drives the first bending wire 125 and the second bending wire 126, and the drive mechanism for the gripper section 100 drives the wire 103. In this case, the wire fixing section 216 shown in Figure 5 functions as a communication section through which the wire 103 passes to the main body 200 and is connected to the drive mechanism.

[0035] Furthermore, although the above embodiment shows a configuration where the wire 103 is a single continuous wire, it is not necessarily required to be continuous. For example, as shown in Figures 8(a) and (b), the wire 103 may be composed of at least one first wire 103a arranged to pass through the first connecting portion 111 of the fixing member 101 and exit from the proximal end to the distal end, and a second wire 103b arranged to pass through the second connecting portion 112 and return from the distal end to the proximal end. In this case, the first wire is fixed in the wire passage 113, and the second wire is fixed in the wire passage 114. The wire passages 113 and 114 also function as guides to position the first wire 103a and the second wire 103b at an acute angle. The first wire 103a and the second wire 103b may have different elastic properties. Alternatively, a plate-shaped elastic member may be used instead of the first wire 103a. Furthermore, as shown in Figure 9(c), multiple first connecting portions 111 and wire passages 113 may be arranged substantially perpendicular to the rotation surface of the movable member 102, and multiple first wires may be provided. Or, in a configuration using a single wire 103 as described in Figure 4, the return force against bending of the hinge portion may be reinforced by providing extra first connecting portions 111 and wire passages 113 and arranging the first wire 103a.

[0036] The invention is not limited to the embodiments described above, and various modifications and changes are possible within the scope of the gist of the invention. [Explanation of Symbols]

[0037] 10: Manipulator, 11: Work unit, 12: Hand unit, 100: Gripper section, 120: Bending mechanism, 130: Unit base, 140: Shaft, 101: Fixing member, 102: Movable member, 103: Wire, 111: First communication section, 112: Second communication section, 113, 114: Wire passage

Claims

1. An end effector that is attached to the tip of a manipulator, Each has a first and second communication portion that connects the proximal end and the distal end, and the proximal end is fixed to the tip of the manipulator as a fixing member, One or more elastic members passing through the first communication portion and extending from the proximal end to the distal end, A wire passing through the second communication section and exiting from the distal end to the proximal end, The system includes a guide means that positions the elastic member and the wire at an acute angle, and a movable member that is connected to the distal end of the fixed member via the elastic member and the wire, The movable member rotates to a first rotational state by applying a tensile force toward the proximal end to the wire at the second communication portion, and in the first rotational state, the elastic member is bent at a predetermined position between the first communication portion and the guide means. The end effector is characterized in that when the tensile force is released, the movable member rotates to a second rotational state due to the elastic force against bending of the elastic member at the predetermined position.

2. The end effector according to claim 1, characterized in that one of the elastic members and the wire is composed of one wire, and the one wire is bent at an acute angle by the guide means.

3. The end effector according to claim 1 or 2, characterized in that the movable member rotates about an axis perpendicular to the longitudinal direction of the elastic member at the predetermined position.

4. The end effector according to claim 1 or 2, characterized in that the fixed member functions as the first jaw of the gripper, and the movable member functions as the second jaw of the gripper.

5. The end effector according to claim 4, characterized in that the first rotation state is a state in which the first jaw portion and the second jaw portion are closed, and the second rotation state is a state in which the first jaw portion and the second jaw portion are open.

6. The end effector according to claim 1 or 2, characterized in that the magnitude of the bending of the elastic member at the predetermined position in the first rotation state is within the range of the elastic limit or hyperelastic limit of the elastic member.

7. The end effector according to claim 1 or 2, characterized in that the magnitude of the bend of the elastic member at the predetermined position in the first rotation state is greater than the magnitude of the bend of the wire occurring between the guide means and the second communication portion.

8. The end effector according to claim 1 or 2, characterized in that the fixed member has a plurality of sets of the first communication portion and the second communication portion, and a plurality of the movable members are connected to the fixed member.

9. An end effector as described in claim 1 or 2, A shaft having one end connected to the fixing member, the shaft being connected to the fixing member such that the wire passes through the second communication portion and the hollow portion of the shaft, A manipulator characterized by comprising: a unit base connected to the other end of the shaft, and having an operating mechanism that applies an operating force to the portion of the wire that has passed through the hollow portion of the wire, for applying the tensile force to the wire.

10. The manipulator according to claim 9, characterized in that the operating mechanism applies an operating force in the part that displaces the wire from the axial direction of the shaft.

11. The operating mechanism has a member having a communication portion through which the wire passes, The manipulator according to claim 10, characterized in that, when no operating force is applied, the hollow portion of the shaft, the wire, and the communication portion of the member are coaxially aligned.

12. It comprises a main body that connects to the base of the unit, The main body has an operating section that is operated by the user, The manipulator according to claim 9, characterized in that, while the main body and the unit base are connected, they are linked to transmit user operations performed on the operating section to the operating mechanism.

13. The aforementioned unit base is, The first base to which the shaft is fixed, The manipulator according to claim 9, further comprising a first base connected to a second base having the operating mechanism, the second base being connected to the first base so as to be able to rotate about the longitudinal direction of the shaft.

14. The manipulator according to claim 9, characterized in that the end effector is connected to the shaft via a bending mechanism.

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