Robot with parallel link

Abstract

To provide a robot with a parallel link allowing for easily detaching an end effector while ensuring accuracy of a mount position of the end effector.SOLUTION: A robot 1 with a parallel link comprises: a third mount part 73 on which a medical instrument 2 can be detachably mounted, in a manner of allowing the medical instrument 2 to move along a second reference axis SL2; and a positioning part 80 which is disposed on the third mount part 73, and positions the medical instrument 2 at a mount position Ps. The positioning part 80 comprises: a ball 82 being movable between a first position P1 where the ball is fit in a recess 2a4 provided in a faced surface 2a3 of the medical instrument 2 when the medical instrument 2 is positioned at the mount position Ps and a second position P2 where the ball is positioned outside the recess 2a4; and a spring 83 that biases the ball 82 from the second position P2 toward the first position P1. When the medical instrument 2 moves from the mount position Ps along the second reference axis SL2, the faced surface 2a3 presses the ball 82 from the first position P1 toward the second position P2.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a robot including a parallel link. [Background technology]

[0002] Patent Document 1 discloses, as an example of a robot, a robot including a parallel link with an end effector. For example, a treatment tool for ophthalmic surgery is attached to the end effector. The robot including the parallel link controls an actuator so as to move the end effector to a desired target position and posture. Furthermore, the robot of Patent Document 1 can be made smaller by including a parallel link. On the other hand, it is known that in a robot including a parallel link, the positioning accuracy of each axis greatly affects the positioning accuracy of the entire robot. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7088440 Summary of the Invention [Problem to be solved by the invention]

[0004] The end effector is replaceable depending on the application. Depending on the application of the end effector, the positional accuracy required for the end effector may be relatively high. Therefore, it is desirable that the accuracy of the mounting position of the end effector with respect to the robot including the parallel link is relatively high.

[0005] Furthermore, for example, if a power outage occurs during ophthalmic surgery using a robot including a parallel link, there is a demand for the end effector to be easily detached from the robot including a parallel link in order to reduce the impact of the end effector on the affected area.

[0006] An aspect of the present disclosure aims to provide a robot including a parallel link that allows an end effector to be easily attached and detached while ensuring the accuracy of the attachment position of the end effector. [Means for solving the problem]

[0007] In an aspect of the present disclosure, a robot including a parallel link includes a housing, a nut housed in the housing, a drive unit having a screw shaft that moves relative to the housing as the nut rotates, and a guide unit that guides an end effector that acts on an object along a reference axis, the guide unit including a slide member that moves integrally with the screw shaft along the reference axis, a mounting unit that is disposed on the slide member and to which the end effector is detachably attached such that the end effector is movable along the reference axis relative to the slide member, and a positioning unit that is disposed on the mounting unit and positions the end effector at an attachment position relative to the slide member. and a fitting portion, the mounting portion being parallel to the reference axis and having an opposing surface facing the end effector, the end effector having a recess in an opposed surface facing the opposing surface when attached to the mounting portion, the positioning portion comprising an engaging portion movable between a first position where the engaging portion fits into the recess while protruding from the opposing surface when the end effector is located at the mounting position and a second position where the engaging portion is disengaged from the recess, and a biasing portion which biases the engaging portion from the second position toward the first position, and when the end effector moves from the mounting position along the reference axis, the opposed surface presses the engaging portion from the first position toward the second position.

[0008] According to an aspect of the present disclosure, when the end effector is manually moved along the reference axis relative to the mounting portion from a state in which the end effector is located at the mounting position, the opposed surface presses the mating portion, and the mating portion comes out of the recess. Furthermore, by moving the end effector, the end effector is removed from the mounting portion. Meanwhile, when the end effector is manually attached to the mounting portion from a state in which the end effector is removed, and the end effector is moved along the reference axis relative to the mounting portion until the end effector is located at the mounting position, the mating portion fits into the recess, and the end effector is positioned. In this way, the end effector can be easily attached and detached while ensuring the accuracy of the mounting position of the end effector.

[0009] In addition, in an aspect of the present disclosure, the periphery of the recess in the opposed surface is circular, the fitting portion is spherical with a diameter larger than the diameter of the periphery of the recess, and the biasing portion is a coil spring.

[0010] According to an aspect of the present disclosure, the positioning portion is a ball plunger, and the accuracy of the mounting position of the end effector can be reliably ensured. Also, when the end effector is manually moved along the reference axis from the mounting position relative to the mounting portion, the periphery of the recess presses the fitting portion, so that the fitting portion can be easily moved from the first position to the second position and easily removed from the recess.

[0011] In addition, in an aspect of the present disclosure, the end effector is provided with a needle member that acts on the object, and the needle member is in a position extending along the reference axis when the end effector is located at the mounting position.

[0012] According to an aspect of the present disclosure, when the end effector is attached or detached, the end effector moves along the direction in which the needle member extends. Therefore, when the end effector is acting on an object, the direction in which the end effector is detached can be a direction away from the object, thereby ensuring the safety of the object.

[0013] In addition, in an aspect of the present disclosure, the guide portion further includes a stopper portion that prevents the end effector from approaching the target object from the attachment position when the end effector is attached to the attachment portion.

[0014] According to an aspect of the present disclosure, the stopper portion can further ensure the safety of the object.

[0015] In addition, in an aspect of the present disclosure, the device further includes an arm unit having two of the drive units and capable of tilting relative to the slide member, and the central axes of the two screw shafts of the arm unit are arranged so as to be parallel to each other.

[0016] According to an aspect of the present disclosure, in a robot including a parallel link having an arm unit that constitutes a parallel link mechanism, the end effector can be easily attached and detached while ensuring the accuracy of the mounting position of the end effector as described above. Effect of the Invention

[0017] According to an aspect of the present disclosure, in a robot including a parallel link, the end effector can be easily attached and detached while ensuring the accuracy of the mounting position of the end effector. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a perspective view of a robot including a parallel link according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is a plan view of the robot including the parallel link shown in FIG. 1 as viewed from the +Z side. [Diagram 3] FIG. 3 is a side view of the robot including the parallel link shown in FIG. 1 as viewed from the -X side. [Figure 4] FIG. 4 is a perspective view of a first arm according to an embodiment of the present disclosure. [Diagram 5] FIG. 5 is a cross-sectional view of the first arm along the first reference axis. [Figure 6] FIG. 6 is a diagram showing a state in which the second arm unit is inclined with respect to the first arm unit from the reference state of the robot including the parallel link shown in FIG. [Figure 7] FIG. 7 is a side view of the robot including the parallel link shown in FIG. 1 as viewed from the -Y side. [Figure 8] FIG. 8 is a diagram showing a state in which the medical instrument has been moved by the third arm unit being driven from the reference state H of the robot including the parallel link shown in FIG. [Figure 9] FIG. 9 is an enlarged view of the robot and medical instrument including the parallel link shown in FIG. [Figure 10] FIG. 10 is a cross-sectional view of the robot including the parallel link and the medical instrument taken along line XX shown in FIG. [Figure 11] FIG. 11 is a diagram of the robot including a parallel link as viewed along the arrow XI shown in FIG. [Figure 12] FIG. 12 is a partially enlarged cross-sectional view showing a state in which the medical instrument shown in FIG. 10 has been moved to the +Z side from a state in which it is located at the attachment position. [Figure 13] FIG. 13 is a diagram illustrating a positioning unit of a robot including a parallel link according to a modified example of an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings, but the present disclosure is not limited thereto. The components of each embodiment and each modified example described below can be appropriately combined. In addition, some components may not be used.

[0020] A robot 1 including a parallel link according to an embodiment of the present disclosure will be described with reference to the drawings.

[0021] In the following description, the Z direction is the up-down direction, the direction perpendicular to the Z direction is the X direction, and the direction perpendicular to the Z direction and the X direction is the Y direction. Note that the X, Y, and Z directions are merely examples, and the present disclosure is not limited to these directions. Also, viewing the robot 1 including the parallel links along the Z direction from the +Z side or -Z side is referred to as a "planar view."

[0022] FIG. 1 is a perspective view of a robot 1 including a parallel link according to an embodiment of the present disclosure. The robot 1 including a parallel link is a medical robot arm used during surgery performed by a doctor. The robot 1 including a parallel link may also be an industrial robot arm used in the production of industrial products. The robot 1 including a parallel link is electrically connected to a control device (not shown) by wire or wirelessly. A doctor operates the control device to operate the robot 1 including a parallel link.

[0023] The robot 1 including a parallel link includes a first arm unit 10, a first joint unit 20a, a second arm unit 30, a second joint unit 20b, and a third arm unit 40. The second arm unit 30 corresponds to an "arm unit." A medical instrument 2 is detachably attached to the third arm unit 40 as an end effector that acts on an object (details will be described later).

[0024] The medical instrument 2 is an instrument used in treatment. The medical instrument 2 of this embodiment includes a columnar main body 2a and a needle-like needle member 2b that is attached to the main body 2a and acts on an object. A doctor performs treatment, for example, by inserting the needle member 2b from the tip of the needle member 2b into the object (e.g., an affected area of ​​a patient). Note that FIG. 1 shows the robot 1 including the parallel link in a reference state H in which the medical instrument 2 is located at an attachment position Ps described later, the tip of the needle member 2b faces the -Z side, and the needle member 2b of the medical instrument 2 extends along the Z direction.

[0025] Fig. 2 is a plan view of the robot 1 including the parallel link shown in Fig. 1 as seen from the +Z side. Fig. 3 is a side view of the robot 1 including the parallel link shown in Fig. 1 as seen from the -X side. Note that Fig. 3 omits the illustration of a counterweight 13, which will be described later.

[0026] 1, 2, and 3 includes a first arm unit 11, a second arm 12, and a counterweight 13. In a reference state H of the robot 1 including a parallel link, the first arm 11 and the second arm 12 are arranged in parallel along the Z direction in a posture extending along the Y direction.

[0027] Fig. 4 is a perspective view of the first arm 11 according to the embodiment of the present disclosure. Fig. 5 is a cross-sectional view of the first arm 11 along the first reference axis line SL1. The first reference axis line SL1 is a reference axis line of the first arm 11.

[0028] The first arm portion 11 includes a drive portion 50a and a first guide portion 60a.

[0029] The driving unit 50a includes a housing 51a, a motor 52a, a nut 53a, and a screw shaft 54a. The housing 51a has a hollow rectangular parallelepiped shape extending along the first reference axis line SL1.

[0030] The motor 52a is a stepping motor and includes a stator 52aa and a rotor 52ba. The stator 52aa is fixed inside the housing 51a. The rotor 52ba passes through the stator 52aa and is disposed in the housing 51a via a first bearing 55 so as to be rotatable relative to the housing 51a.

[0031] The nut 53a is accommodated in the housing 51a via a second bearing 56 so as to be rotatable relative to the housing 51a. The nut 53a is fixed to the rotor 52ba and rotates integrally with the rotor 52ba.

[0032] The nut 53a includes a plurality of balls (not shown). The inner circumferential surface of the nut 53a has a spiral groove (not shown) in which the plurality of balls can roll. When the nut 53a rotates, the plurality of balls circulate inside the nut 53a.

[0033] The screw shaft 54a is disposed with a first end portion disposed within the housing 51a and a second end portion exposed from the housing 51a. The central axis CL1 of the screw shaft 54a is aligned so as to be parallel to the first reference axis SL1.

[0034] The screw shaft 54a passes through the rotor 52ba and the nut 53a. The outer circumferential surface of the screw shaft 54a has a spiral groove (not shown) into which a plurality of balls provided in the nut 53a are rollably fitted. The screw shaft 54a moves relative to the housing 51a as the nut 53a rotates.

[0035] The first guide portion 60a guides the screw shaft 54a along the first reference axis SL1. The first guide portion 60a includes a support 61a, a slide member 62a, two guide rails 63aa, 63ba, four linear guides 64aa, 64ba, 64ca, 64da, and a linear encoder 65a.

[0036] The support body 61a has a cylindrical shape that is rectangular in cross section and extends along the first reference axis line SL1, and is fixed to the housing 51a.

[0037] The slide member 62a is L-shaped and integrally includes a fixed portion 62aa and a rectangular parallelepiped portion 62ba. A second end of the screw shaft 54a is fixed to the fixed portion 62aa. Therefore, the slide member 62a moves integrally with the screw shaft 54a relative to the housing 51a. The rectangular parallelepiped portion 62ba penetrates the support body 61a along the first reference axis SL1.

[0038] The two guide rails 63aa, 63ba extend along the first reference axis SL1, and are fixed at positions opposite to each other on the rectangular parallelepiped portion 62ba of the slide member 62a.

[0039] The four linear guides 64aa, 64ba, 64ca, and 64da are fixed inside the support 61a and guide the two guide rails 63aa and 63ba along the first reference axis SL1. Specifically, the two linear guides 64aa and 64ba are disposed apart from each other in the direction along the first reference axis SL1 and guide the guide rail 63aa. The two linear guides 64ca and 64da are disposed apart from each other in the direction along the first reference axis SL1 and guide the guide rail 63ba.

[0040] As described above, the support 61a is fixed to the housing 51a, and the guide rails 63aa, 63ba are disposed on the slide member 62a. Therefore, the slide member 62a can move along the first reference axis SL1 relative to the housing 51a by the linear guides 64aa, 64ba, 64ca, 64da. As described above, the slide member 62a moves integrally with the screw shaft 54a. Therefore, the first guide portion 60a guides the screw shaft 54a along the first reference axis SL1.

[0041] The linear encoder 65a includes a scale 65aa and a head 65ba. The scale 65aa is disposed on the slide member 62a along the first reference axis SL1. Therefore, the scale 65aa moves integrally with the screw shaft 54a relative to the housing 51a. The head 65ba is disposed on a support 61a fixed to the housing 51a. In other words, the linear encoder 65a detects the amount of movement of the screw shaft 54a relative to the housing 51a.

[0042] When a voltage is applied to the motor 52a, the rotor 52ba rotates, and the nut 53a rotates. As a result, the screw shaft 54a moves relative to the housing 51a. The screw shaft 54a moves along the first reference axis SL1 by being guided by the first guide portion 60a.

[0043] The second arm 12 shown in Fig. 3 has the same configuration as the first arm 11 described above, and a description of the configuration of the second arm 12 will be omitted. However, the reference numerals of the components of the second arm 12 are the same as those of the components of the first arm 11 corresponding to the components of the second arm 12, except that the suffix "a" is changed to "b". For example, the second arm 12 includes a drive unit 50b and a first guide unit 60b.

[0044] The first arm 11 and the second arm 12 are arranged so that the first reference axis SL1 are parallel to each other. In addition, the alignment is adjusted so that the central axis CL1 of the screw shafts 54a, 54b and the first reference axis SL1 are parallel to each other. Therefore, the first arm 11 and the second arm 12 are arranged so that the central axis CL1 of the screw shafts 54a, 54b are parallel to each other. In the reference state H of the robot 1 including the parallel link, the central axis CL1 of the screw shafts 54a, 54b of the first arm unit 10 and the first reference axis SL1 are aligned along the Y direction. The counterweight 13 is attached to the slide member 62a of the first arm 11 (see FIG. 2).

[0045] 2 and 3 connects the first arm unit 10 and the second arm unit 30 so that the second arm unit 30 can be tilted relative to the first arm unit 10. The first joint unit 20a includes a first link 21a, a second link 22a, a cylindrical first shaft member 23a, a third link 24a, a fourth link 25a, and a cylindrical second shaft member 26a.

[0046] The first link 21a is fixed to a slide member 62a of the first arm portion 11. The second link 22a is connected to a planar first mounting surface 30b of the first mounting portion 30a of the second arm unit 30 via a linear guide 27a and a guide rail 30c. As a result, the second link 22a is connected to the first mounting surface 30b so as to be movable along the first mounting surface 30b.

[0047] The first link 21a and the second link 22a are connected via a first shaft member 23a so as to be relatively tiltable about a central axis CL2a of the first shaft member 23a. In a reference state H of the robot 1 including the parallel links, the central axis CL2a of the first shaft member 23a is aligned along the X direction.

[0048] A first end of the third link 24a is fixed to the slide member 62b of the second arm portion 12. The fourth link 25a is fixed to the first mounting surface 30b.

[0049] The third link 24a and the fourth link 25a are connected via a second shaft member 26a so as to be relatively tiltable about a central axis CL3a of the second shaft member 26a. The central axis CL3a of the second shaft member 26a is parallel to the central axis CL2a of the first shaft member 23a.

[0050] In this manner, the first attachment portion 30a of the second arm unit 30 and the first arm unit 10 are connected via the first joint portion 20a, so that the first arm unit 10, the first joint portion 20a, and the first attachment portion 30a form a so-called parallel link mechanism. As a result, the second arm unit 30 inclines and moves in translation relative to the first arm unit 10, as will be described next.

[0051] Fig. 6 is a diagram showing a state in which the second arm unit 30 is inclined with respect to the first arm unit 10 from the reference state H of the robot 1 including the parallel link shown in Fig. 3. When the screw shaft 54a in the first arm 11 moves from the reference state H of the robot 1 including the parallel link shown in Fig. 3 to the side where it protrudes from the housing 51a, as shown in Fig. 6, the second link 22a inclines with respect to the first link 21a and the fourth link 25a inclines with respect to the third link 24a in the counterclockwise direction in Fig. 6, so that the second arm unit 30 inclines with respect to the first arm unit 10.

[0052] In addition, when the screw shaft 54b in the second arm 12 moves from the reference state H of the robot 1 including the parallel link shown in Figure 3 toward the side where it protrudes from the housing 51b, the second link 22a tilts clockwise in Figure 6 relative to the first link 21a, and the fourth link 25a tilts relative to the third link 24a, causing the second arm unit 30 to tilt relative to the first arm unit 10.

[0053] Furthermore, from the reference state H of the robot 1 including the parallel link shown in Figure 3, when the screw shafts 54a, 54b in the first arm 11 and the second arm 12, respectively, move at equal speeds toward the sides protruding from the housings 51a, 51b, the second arm unit 30 moves translationally toward the +Y side relative to the first arm unit 10.

[0054] As shown in FIGS. 1, 2 and 3, the second arm unit 30 includes a first attachment portion 30a, a third arm portion 31 and a fourth arm portion 32.

[0055] As described above, the first attachment portion 30a has a first attachment surface 30b to which the second link 22a and the fourth link 25a of the first joint portion 20a are connected.

[0056] The third arm 31 and the fourth arm 32 are arranged in parallel along the Z direction in a posture extending along the X direction in a reference state H of the robot 1 including a parallel link.

[0057] The third arm 31 and the fourth arm 32 have the same configuration as the first arm 11, and the description of the configuration of the third arm 31 and the fourth arm 32 will be omitted. However, the reference numerals of the components of the third arm 31 are the same as those of the components of the first arm 11 corresponding to the components of the third arm 31, except that the suffixes of the reference numerals are changed from "a" to "c". For example, the third arm 31 includes a drive unit 50c and a first guide unit 60c. Also, the reference numerals of the components of the fourth arm 32 are the same as those of the components of the first arm 11 corresponding to the components of the fourth arm 32, except that the suffixes of the reference numerals are changed from "a" to "d". For example, the fourth arm 32 includes a drive unit 50d and a first guide unit 60d.

[0058] The third arm 31 and the fourth arm 32 are arranged so that the first reference axis SL1 are parallel to each other. The alignment is adjusted so that the central axis CL1 of the screw shafts 54c and 54d and the first reference axis SL1 are parallel to each other. Therefore, the third arm 31 and the fourth arm 32 are arranged so that the central axis CL1 of the screw shafts 54c and 54d are parallel to each other. In the reference state H of the robot 1 including the parallel link, the central axis CL1 of the screw shafts 54c and 54d of the second arm unit 30 and the first reference axis SL1 are aligned along the X direction.

[0059] The second joint section 20b connects the second arm unit 30 and the third arm unit 40 so that the third arm unit 40 can be tilted relative to the second arm unit 30. The second joint section 20b has the same configuration as the first joint section 20a, and the description of the second joint section 20b is omitted. However, the reference numerals of the components of the second joint section 20b are the same as those of the components of the first joint section 20a corresponding to the components of the second joint section 20b, except that the suffix of the reference numerals is changed from "a" to "b". The second joint section 20b connects the second arm unit 30 and the third arm unit 40 in the same manner as the connection between the first arm unit 10 and the second arm unit 30 by the first joint section 20a.

[0060] As shown in FIG. 2, in the second joint portion 20b, the second link 22b is connected to a second mounting surface 40b of a second mounting portion 40a (described later) of the third arm unit 40 via a linear guide 27b and a guide rail 40c. As a result, the second link 22b is connected to the second mounting surface 40b so as to be movable along the second mounting surface 40b. In addition, in the reference state H of the robot 1 including the parallel link, the first shaft member 23b is disposed so that the central axis CL2b of the first shaft member 23b is aligned along the Y direction. The fourth link 25b shown in FIG. 1 is fixed to the second mounting surface 40b.

[0061] In this way, the second attachment portion 40a of the third arm unit 40 and the second arm unit 30 are connected via the second joint portion 20b, so that the second arm unit 30, the second joint portion 20b, and the second attachment portion 40a form a so-called parallel link mechanism. Therefore, the third arm unit 40 inclines clockwise and counterclockwise relative to the second arm unit 30 in Fig. 14 described later and translates along the X direction, similar to the inclination and translation of the second arm unit 30 relative to the first arm unit 10 described above. In addition, a slide member 71, which will be described later, is disposed on the second attachment portion 40a. That is, the second arm unit 30 is tiltable with respect to the slide member 71.

[0062] 7 is a side view of the robot 1 including the parallel link shown in FIG. 1, as viewed from the -Y side. As shown in FIGS. 2 and 7, in the reference state H of the robot 1 including the parallel link, the second reference axis SL2 of the third arm unit 40 extends along the Z direction. The second reference axis SL2 is the reference axis of the third arm unit 40. The second reference axis SL2 corresponds to the "reference axis." The third arm unit 40 includes a drive unit 50e and a second guide unit 70.

[0063] The driving unit 50e of the third arm unit 40 has the same configuration as the driving unit 50a of the first arm unit 10 described above, and therefore a description of the configuration of the driving unit 50e of the third arm unit 40 will be omitted. However, the reference numerals of the components of the driving unit 50e of the third arm unit 40 are the same as those of the components of the driving unit 50a of the first arm unit 10 that correspond to the components of the driving unit 50e of the third arm unit 40, except that the suffix of the reference numerals has been changed from "a" to "e."

[0064] The second guide portion 70 guides the medical instrument 2. The second guide portion 70 corresponds to the “guide portion.” The second guide portion 70 includes the second attachment portion 40a, a slide member 71, and a linear encoder 72.

[0065] 2, a driving unit 50e is fixed to the second mounting portion 40a. The second mounting portion 40a has a second mounting surface 40b to which the second joint portion 20b is connected, and a guide surface 40d. As described above, the second link 22b and the fourth link 25b of the second joint portion 20b are connected to the second mounting surface 40b.

[0066] The guide surface 40d is parallel to the second mounting surface 40b. A slide member 71 is attached to the guide surface 40d so as to be movable relative to the second mounting portion 40a. Specifically, a linear guide 71a is fixed to the slide member 71, and a guide rail 40e that fits with the linear guide 71a is fixed to the guide surface 40d. The guide rail 40e extends along the second reference axis SL2. Therefore, the slide member 71 moves along the second reference axis SL2 relative to the second mounting portion 40a.

[0067] As shown in FIG. 7, the slide member 71 is fixed to the second end of the screw shaft 54e of the driving unit 50e. The medical instrument 2 is attached to the slide member 71. That is, when the screw shaft 54e of the driving unit 50e moves, the slide member 71 and the medical instrument 2 move together along the second reference axis line SL2 with respect to the second mounting portion 40a. That is, the second guide portion 70 guides the medical instrument 2 along the second reference axis line SL2. The second guide portion 70 also guides the screw shaft 54e along the second reference axis line SL2. The central axis line CL1 of the screw shaft 54e of the driving unit 50e is aligned with the second reference axis line SL2.

[0068] The linear encoder 72 has a configuration similar to that of the linear encoder 25. The linear encoder 72 includes a scale 72a and a head 72b.

[0069] The scale 72a is disposed on the second mounting portion 40a along the second reference axis SL2. The head 72b is disposed on a slide member 71 that moves integrally with the screw shaft 54e of the drive portion 50e in a state facing the scale 72a.

[0070] The linear encoder 72 detects the amount of movement of the head 72b in the direction along the second reference axis SL2. The housing 51e of the drive unit 50e is fixed to the second mounting portion 40a on which the scale 72a is disposed. The head 72b moves integrally with the screw shaft 54e relative to the housing 51e of the drive unit 50e. Thus, the linear encoder 72 detects the amount of movement of the screw shaft 54e of the drive unit 50e in the direction along the second reference axis SL2.

[0071] Fig. 8 is a diagram showing a state in which the medical instrument 2 is moved by driving the third arm unit 40 from the reference state H of the robot 1 including the parallel link shown in Fig. 7. When the screw shaft 54e of the drive unit 50e moves from the reference state H of the robot 1 including the parallel link shown in Fig. 7 to the side where it protrudes from the housing 51e, the medical instrument 2 moves along the second reference axis line SL2 to the -Z side as shown in Fig. 8. On the other hand, when the screw shaft 54e of the drive unit 50e moves from the state of the robot 1 including the parallel link shown in Fig. 8 toward the side where it fits into the housing 51e, the medical instrument 2 moves along the second reference axis line SL2 to the +Z side as shown in Fig. 7.

[0072] In the robot 1 including the parallel link configured as described above, a doctor inputs the operation amount (movement direction and movement amount) of the medical instrument 2 to the control device. The control device adjusts the movement amount of each of the screw shafts 54a, 54b, 54c, 54d, 54e corresponding to the input operation amount of the medical instrument 2 based on the detection values ​​of each of the linear encoders 65a, 65b, 65c, 65d, 72. As described above, each of the screw shafts 54a, 54b, 54c, 54d, 54e is guided by the slide members 62a, 62b, 62c, 62d, 71, and moves with high precision along the reference axes SL1, SL2.

[0073] This allows for precise adjustment of the attitude and position of the second arm unit 30 and the third arm unit 40 relative to the first arm unit 10. Furthermore, the attitude and position of the medical instrument 2 is precisely adjusted, and the medical instrument 2 moves precisely.

[0074] Fig. 9 is an enlarged view of the robot 1 and medical instrument 2 including the parallel link shown in Fig. 2. Fig. 10 is a cross-sectional view of the robot 1 and medical instrument 2 including the parallel link taken along line XX shown in Fig. 9. Fig. 11 is an arrow view of the robot 1 including the parallel link as viewed along arrow XI shown in Fig. 10. Note that in the medical instrument 2 shown in Fig. 11, only an attachment portion 2a1, which will be described later, is indicated by a dashed line.

[0075] The main body 2a of the medical device 2 has an integral attachment portion 2a1. The attachment portion 2a1 has a pair of protrusions 2a2 and an opposed surface 2a3.

[0076] When the medical instrument 2 is attached to the slide member 71, the pair of protruding portions 2a2 are plate-shaped and protrude in a direction perpendicular to the second reference axis SL2 and extend along the second reference axis SL2.

[0077] When the medical instrument 2 is attached to the slide member 71, the opposed surface 2a3 faces an opposed surface 73a of a third attachment portion 73 described below. Furthermore, the medical instrument 2 has a recess 2a4 on the opposed surface 2a3 (FIGS. 10 and 11). The recess 2a4 is a depression recessed from the opposed surface 2a3 toward the inside of the attachment portion 2a1. The periphery of the recess 2a4 on the opposed surface 2a3 is circular.

[0078] The second guide portion 70 further includes a third attachment portion 73, a positioning portion 80, and a stopper portion 90. The third attachment portion 73 corresponds to the "attachment portion".

[0079] The third attachment portion 73 is disposed on the slide member 71, and the medical instrument 2 is detachably attached to the slide member 71 so that the medical instrument 2 is movable along the second reference axis line SL2 relative to the slide member 71. The third attachment portion 73 includes an opposing surface 73a and a pair of guide portions 73b.

[0080] The facing surface 73a is parallel to the second reference axis line SL2 and faces the medical instrument 2.

[0081] The pair of guide portions 73b guide the pair of protrusions 2a2 along the second reference axis SL2. The pair of guide portions 73b have a U-shaped cross section into which the pair of protrusions 2a2 are fitted so as to be movable along the second reference axis SL2.

[0082] 10 and 11 is disposed on the third mounting portion 73 and positions the medical instrument 2 at a mounting position Ps with respect to the slide member 71. The medical instrument 2 shown in Fig. 10 is located at the mounting position Ps. When the medical instrument 2 is located at the mounting position Ps, the needle member 2b is in a position extending along the second reference axis line SL2.

[0083] The positioning part 80 is a so-called ball plunger. The positioning part 80 includes a casing 81, a ball 82, and a spring 83. In this embodiment, the ball 82 corresponds to the "fitting part", and the spring 83 corresponds to the "urging part".

[0084] The casing 81 is tubular with one end open, and is disposed on the third attachment portion 73 without protruding from the opposing surface 73a.

[0085] The ball 82 is held in the casing 81 so as to be movable along a central axis CL4 of the casing 81. The ball 82 is spherical and has a diameter larger than the diameter of the periphery of the recess 2a4.

[0086] The spring 83 is a coil spring. The spring 83 is housed in the casing 81 in a state in which the spring 83 extends along a central axis CL4 of the casing 81. The spring 83 biases the ball 82 toward the outside of the casing 81.

[0087] When the ball 82 is pressed by an external force, it moves toward the inside of the casing 81 and the spring 83 contracts. When the external force is removed, the spring 83 expands, and the ball 82 is held by the casing 81 in a state in which it protrudes from the opposing surface 73a.

[0088] Furthermore, when the medical device 2 is located at the attachment position Ps, the ball 82 fits into the recess 2a4 in a state where it protrudes from the opposing surface 73a. At this time, with the center of the ball 82 located outside the recess 2a4, the outer surface of the ball 82 comes into contact with the periphery of the recess 2a4. Also, at this time, the ball 82 is pressed toward the recess 2a4 by the spring 83. This prevents the medical device 2 from shifting from the attachment position Ps. Therefore, the positioning unit 80 can ensure the accuracy of the attachment position Ps of the medical device 2.

[0089] The stopper portion 90 prevents the medical instrument 2 from approaching the target object from the attachment position Ps when the medical instrument 2 is attached to the third attachment portion 73. The stopper portion 90 is integral with the third attachment portion 73. Note that the stopper portion 90 may be separate from the third attachment portion 73.

[0090] When the medical instrument 2 is located at the attachment position Ps, the stopper portion 90 is located on the -Z side of the attached portion 2a1, and the gap between the attached portion 2a1 and the stopper portion 90 is extremely small. Therefore, in Fig. 10, when the medical instrument 2 moves from the attachment position Ps to the -Z side with respect to the third attachment portion 73, the attached portion 2a1 comes into contact with the stopper portion 90, and the medical instrument 2 stops. Therefore, for example, when the needle member 2b acts on the target object, even if the medical instrument 2 moves from the attachment position Ps toward the target object with respect to the third attachment portion 73, the attached portion 2a1 comes into contact with the stopper portion 90, and the medical instrument 2 can be prevented from approaching the target object.

[0091] Next, the operation of the robot 1 including the parallel links when the medical instrument 2 is removed from the state in which the medical instrument 2 is located at the attachment position Ps will be described with reference to Figures 10 and 12. Hereinafter, when the medical instrument 2 shown in Figure 10 is located at the attachment position Ps, the position of the ball 82 fitted in the recess 2a4 is defined as a first position P1 of the ball 82.

[0092] Fig. 12 is a partially enlarged cross-sectional view showing a state in which the medical instrument 2 shown in Fig. 10 has moved to the +Z side from a state in which it is located at the attachment position Ps. The attachment and detachment of the medical instrument 2 is performed manually.

[0093] 10, when the medical instrument 2 is removed from the mounting position Ps, the medical instrument 2 is slid toward the +Z side. The direction in which the medical instrument 2 slides toward the +Z side is the direction in which the medical instrument 2 moves away from the object when the medical instrument 2 acts on the object. The pair of protrusions 2a2 are guided by the pair of guide portions 73b, and the medical instrument 2 moves toward the +Z side along the second reference axis SL2.

[0094] At this time, the periphery of the recess 2a4 in the opposed surface 2a3 presses the ball 82, causing the ball 82 to move toward the inside of the casing 81. When the medical instrument 2 moves further toward the +Z side, the ball 82 comes out of the recess 2a4, as shown in Fig. 12. At this time, the spring 83 biases the ball 82 toward the attachment portion 2a1, causing the ball 82 to come into contact with the opposed surface 2a3, and the opposed surface 2a3 presses the ball 82. The position of the ball 82 where it comes into contact with the opposed surface 2a3 is defined as the second position P2 of the ball 82.

[0095] 12, when the medical device 2 moves to the +Z side and the attached portion 2a1 is positioned on the +Z side of the ball 82, the ball 82 comes off the opposed surface 2a3 and is held by the casing 81 while being biased by the spring 83. When the medical device 2 further moves to the +Z side, the pair of protrusions 2a2 comes off the pair of guide portions 73b. This completes the removal of the medical device 2.

[0096] Next, the operation of the robot 1 including the parallel link when the medical instrument 2 is attached will be described. The pair of protrusions 2a2 are inserted into the pair of guide parts 73b from the +Z side of the third attachment part 73, and the medical instrument 2 is moved to the -Z side along the second reference axis line SL2. When the attached part 2a1 comes into contact with the ball 82 and the medical instrument 2 moves further to the -Z side, the opposed surface 2a3 presses the ball 82 as shown in FIG. 12, and the ball 82 is located at the second position P2.

[0097] When the medical instrument 2 moves further to the -Z side and reaches the attachment position Ps, the ball 82 moves from the second position P2 to the first position P1 and fits into the recess 2a4. This positions the medical instrument 2 and completes the attachment of the medical instrument 2.

[0098] In this way, the medical instrument 2 can be easily attached and detached manually. The ball 82 is movable between the first position P1 and the second position P2. The spring 83 biases the ball 82 from the second position P2 toward the first position P1. When the medical instrument 2 moves from the mounting position Ps along the second reference axis SL2, the opposed surface 2a3 presses the ball 82 from the first position P1 toward the second position P2.

[0099] As described above, according to this embodiment, the robot 1 including the parallel link includes the housing 51e, the nut 53e housed in the housing 51e, the drive unit 50e having the screw shaft 54e that moves relative to the housing 51e as the nut 53e rotates, and the second guide unit 70 that guides the medical instrument 2 acting on the target object along the second reference axis SL2. The second guide unit 70 includes a slide member 71 that moves together with the screw shaft 54e along the second reference axis SL2, a third attachment unit 73 that is disposed on the slide member 71 and to which the medical instrument 2 is detachably attached so that the medical instrument 2 can move along the second reference axis SL2 relative to the slide member 71, and a positioning unit 80 that is disposed on the third attachment unit 73 and positions the medical instrument 2 at an attachment position Ps relative to the slide member 71. The third attachment unit 73 has an opposing surface 73a that is parallel to the second reference axis SL2 and faces the medical instrument 2. The medical instrument 2 has a recess 2a4 on an opposed surface 2a3 opposed to the opposing surface 73a when attached to the third attachment portion 73. The positioning portion 80 includes a ball 82 movable between a first position P1 where the ball 82 fits into the recess 2a4 while protruding from the opposing surface 73a when the medical instrument 2 is located at the attachment position Ps and a second position P2 where the ball 82 is removed from the recess 2a4, and a spring 83 that biases the ball 82 from the second position P2 toward the first position P1. When the medical instrument 2 moves from the attachment position Ps along the second reference axis SL2, the opposed surface 2a3 presses the ball 82 from the first position P1 toward the second position P2. According to this, when the medical instrument 2 is manually moved from the state where the medical instrument 2 is located at the attachment position Ps to the third attachment section 73 along the second reference axis line SL2, the opposed surface 2a3 presses the ball 82, and the ball 82 comes out of the recess 2a4. Furthermore, by moving the medical instrument 2, the medical instrument 2 is removed from the third attachment section 73. On the other hand, when the medical instrument 2 is manually attached to the third attachment section 73 from the state where the medical instrument 2 is removed, and the medical instrument 2 is moved from the state where the medical instrument 2 is removed to the third attachment section 73 along the second reference axis line SL2, and the medical instrument 2 is located at the attachment position Ps, the ball 82 fits into the recess 2a4, and the medical instrument 2 is positioned. In this way, the medical instrument 2 can be easily attached and detached while ensuring the accuracy of the attachment position Ps of the medical instrument 2.

[0100] The periphery of the recess 2a4 in the opposed surface 2a3 is circular. The ball 82 is spherical and has a diameter larger than the diameter of the periphery of the recess 2a4. The spring 83 is a coil spring. According to this, the positioning portion 80 is a ball plunger, and it is possible to reliably ensure the accuracy of the mounting position Ps of the medical instrument 2. Furthermore, when the medical instrument 2 is manually moved along the second reference axis line SL2 relative to the third mounting portion 73 from a state in which the medical instrument 2 is located at the mounting position Ps, the periphery of the recess 2a4 presses the ball 82, so that the ball 82 can easily move from the first position P1 to the second position P2 and can easily come out of the recess 2a4.

[0101] The medical instrument 2 also includes a needle member 2b that acts on an object. The needle member 2b is in a position extending along the second reference axis line SL2 when the medical instrument 2 is located at the attachment position Ps. According to this, when attaching or detaching the medical instrument 2, the medical instrument 2 moves along the direction in which the needle member 2b extends. Therefore, when the medical instrument 2 acts on an object, the direction in which the medical instrument 2 is detached can be a direction away from the object. Therefore, the safety of the object can be ensured. For example, even if the robot 1 including the parallel link stops while maintaining its posture due to a power outage or the like while the needle member 2b is acting on the target object, the safety of the target object can be reliably ensured by setting the direction in which the medical instrument 2 is removed to be away from the target object.

[0102] Moreover, the second guide portion 70 further includes a stopper portion 90 that prevents the medical instrument 2 from approaching the target object side from the attachment position Ps when the medical instrument 2 is attached to the third attachment portion 73. According to this, the stopper portion 90 can further ensure the safety of the object.

[0103] Moreover, the robot 1 including the parallel link further includes a second arm unit 30 that has two drive units 50c, 50d and is tiltable with respect to the slide member 71. The central axes CL1 of the two screw shafts 54c, 54d of the second arm unit 30 are arranged so as to be parallel to each other. According to this, in the robot 1 including a parallel link equipped with the second arm unit 30 constituting a parallel link mechanism, the medical instrument 2 can be easily attached and detached while ensuring the accuracy of the mounting position Ps of the medical instrument 2 as described above.

[0104] Next, a robot 1 including a parallel link according to a modified example of the embodiment of the present disclosure will be described.

[0105] FIG. 13 is a diagram showing a positioning unit 180 of a robot 1 including a parallel link according to a modification of the embodiment of the present disclosure. In the robot 1 including a parallel link according to this modification, the positioning unit 180 is a hook and is integrated with the third attachment unit 73. The positioning unit 180 also has an engagement unit 182 and a biasing unit 183 integrated therewith. The outer surface of the engagement unit 182 is a curved surface that fits into the recess 2a4 when the medical instrument 2 is located at the attachment position Ps. The position of the engagement unit 182 shown by the solid line in FIG. 13 is a first position P1 where the engagement unit 182 fits into the recess 2a4. The position of the engagement unit 182 shown by the dashed line in FIG. 13 is a second position P2 where the engagement unit 182 is removed from the recess 2a4.

[0106] When the medical instrument 2 moves from the mounting position Ps along the second reference axis line SL2, the opposed surface 2a3 presses the fitting portion 182. This causes the biasing portion 183 to elastically deform, and the fitting portion 182 moves in the direction of the arrow shown in Fig. 13 and is located at the second position P2 where it comes into contact with the opposed surface 2a3.

[0107] On the other hand, when the medical instrument 2 is located at the attachment position Ps from a state in which the fitting portion 182 is disengaged from the recess 2a4, the biasing portion 183 is restored to its original state, and the fitting portion 182 moves from the second position P2 to the first position P1 and fits into the recess 2a4. This positions the medical instrument 2.

[0108] Also, the first arm unit 10, the first joint portion 20a, and the first attachment portion 30a do not have to configure a parallel link mechanism. In this case, for example, the first arm unit 10 does not include the first arm portion 11. Also, in this case, the first joint portion 20a does not include the first link 21a, the second link 22a, and the first shaft member 23a that connect the first arm portion 11 and the first attachment portion 30a of the second arm unit 30, and includes a motor that tilts the second arm unit 30 around the central axis line CL3a relative to the first arm unit 10.

[0109] Also, the second arm unit 30, the second joint portion 20b, and the second attachment portion 40a do not have to configure a parallel link mechanism. In this case, for example, the second arm unit 30 does not include the third arm portion 31. Also, in this case, the second joint portion 20b does not include the first link 21b, the second link 22b, and the first shaft member 23b that connect the third arm portion 31 and the second attachment portion 40a of the third arm unit 40, and includes a motor that tilts the third arm unit 40 around the central axis line CL3b relative to the second arm unit 30. [Explanation of symbols]

[0110] 1 Robot with parallel links 2 Medical instruments (end effectors) 2a3 Opposed surface 2a4 Recess 2b Needle member 30 Second Arm Unit (Arm Unit) 50c Drive unit 50d Drive unit 50e Drive unit 51e Housing 53e Nut 70 Second guide part (guide part) 71 Slide member 73 Third mounting part (mounting part) 73a Opposite side 80 Positioning part 82 Ball (fitting part) 83 Spring (biasing part) 90 Stopper part 180 Positioning part 182 Fitting part 183 Pressurizing part CL1 Central axis of the screw shaft P1 1st position P2 2nd position Ps Mounting position SL2 2nd reference axis (reference axis)

Claims

1. a housing, a nut housed in the housing, and a drive unit having a screw shaft that moves relative to the housing as the nut rotates; A guide portion that guides an end effector that acts on an object along a reference axis, The guide portion is A slide member that moves integrally with the screw shaft along the reference axis; a mounting portion disposed on the slide member, to which the end effector is detachably attached so that the end effector is movable along the reference axis relative to the slide member; a positioning portion disposed on the mounting portion and configured to position the end effector at a mounting position relative to the slide member; the mounting portion is parallel to the reference axis and has an opposing surface facing the end effector; the end effector has a recess in an opposed surface that faces the opposing surface when the end effector is attached to the attachment portion, The positioning portion is a fitting portion movable between a first position where the fitting portion fits into the recess in a state where the fitting portion protrudes from the opposing surface when the end effector is located at the attachment position, and a second position where the fitting portion is disengaged from the recess; a biasing portion that biases the fitting portion from the second position toward the first position, When the end effector moves from the mounting position along the reference axis, the opposed surface presses the fitting portion from the first position toward the second position. A robot that includes a parallel link.

2. The periphery of the recess in the opposed surface is circular, the fitting portion is spherical and has a diameter larger than a diameter of a periphery of the recess; The biasing portion is a coil spring. A robot comprising the parallel link according to claim 1.

3. The end effector includes a needle member that acts on the object, the needle member is in a position extending along the reference axis when the end effector is located at the mounting position; A robot comprising the parallel link according to claim 1.

4. the guide portion further includes a stopper portion that prevents the end effector from approaching the target object from the attachment position when the end effector is attached to the attachment portion. A robot comprising the parallel link according to claim 1.

5. an arm unit having two of the drive units and tiltable with respect to the slide member; The central axes of the two screw shafts of the arm unit are arranged to be parallel to each other. A robot comprising the parallel link according to claim 1.

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