Parallel link mechanism, robot mechanism, and braking method

Abstract

To provide a parallel link mechanism and a robot mechanism which can be more down-sized, and a braking method which enables the parallel link mechanism to be more down-sized.SOLUTION: A parallel link mechanism according to an embodiment comprises a proximal part, a movable part, a braking part, a plurality of motors, a plurality of links, and a changeover part. The movable part is distant from the proximal part in a first direction. The braking part is provided between the proximal part and the movable part, and includes a plurality of braking pads. The plurality of motors is provided around the braking part, and each includes a drive shaft along a direction crossing the first direction. The plurality of links is each coupled between the plurality of drive shafts and the plurality of movable parts. The changeover part is provided between the proximal part and the movable part. The changeover part moves the plurality of braking pads, thereby changing over a contact state that the plurality of braking pads contacts the plurality of drive shafts and a non-contact state that the plurality of braking pads is distant from the plurality of drive shafts.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] FIELD Embodiments of the present invention relate to a parallel link mechanism, a robot mechanism, and a braking method. [Background technology]

[0002] There is a parallel link mechanism that includes multiple motors and multiple links. There is a demand for technology that can further reduce the size of parallel link mechanisms. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2021-137939 Summary of the Invention [Problem to be solved by the invention]

[0004] The problem to be solved by the present invention is to provide a parallel link mechanism and a robot mechanism that can be made smaller, and a braking method that can make the parallel link mechanism smaller. [Means for solving the problem]

[0005] A parallel link mechanism according to an embodiment includes a base, a movable unit, a braking unit, multiple motors, multiple links, and a switching unit. The movable unit is spaced apart from the base in a first direction. The braking unit is provided between the base and the movable unit and includes multiple braking pads. The multiple motors are provided around the braking unit and each includes a drive shaft that extends in a direction intersecting the first direction. The multiple links are respectively connected between the multiple drive shafts and the movable unit. The switching unit is provided between the base and the movable unit. The switching unit moves the multiple brake pads to switch between a contact state in which the multiple brake pads are in contact with the multiple drive shafts and a non-contact state in which the multiple brake pads are spaced apart from the multiple drive shafts. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a perspective view illustrating a parallel link mechanism according to an embodiment. [Figure 2] FIG. 2 is a perspective cross-sectional view showing a part of the parallel link mechanism according to the embodiment. [Figure 3] FIG. 2 is a schematic plan view showing a part of the parallel link mechanism according to the embodiment. [Figure 4] FIG. 4 is a schematic cross-sectional view corresponding to the state shown in FIG. 3. [Figure 5] FIG. 2 is a schematic plan view showing a part of the parallel link mechanism according to the embodiment. [Figure 6] FIG. 6 is a schematic cross-sectional view corresponding to the state shown in FIG. 5. [Figure 7] FIG. 1 is a schematic diagram illustrating a configuration of a robot mechanism according to an embodiment. [Figure 8] 1A is a schematic diagram showing the movement of a robot mechanism according to a reference example, and FIG. 1B is a schematic diagram showing the movement of a robot mechanism according to an embodiment. [Figure 9] FIG. 4 is a schematic cross-sectional view showing a part of a parallel link mechanism according to a first modified example of the embodiment. [Figure 10] FIG. 4 is a schematic cross-sectional view showing a part of a parallel link mechanism according to a first modified example of the embodiment. [Figure 11] FIG. 10 is a schematic cross-sectional view showing a part of a parallel link mechanism according to a second modified example of the embodiment. [Figure 12] FIG. 10 is a schematic cross-sectional view showing a part of a parallel link mechanism according to a second modified example of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the size ratio between parts, etc. are not necessarily the same as those in reality. Even when the same part is shown, the dimensions and ratios may be different depending on the drawing. In the present specification and the drawings, elements similar to those already explained are given the same reference numerals and detailed explanations will be omitted as appropriate.

[0008] Fig. 1 is a perspective view illustrating a parallel link mechanism according to an embodiment, and Fig. 2 is a perspective cross-sectional view illustrating a part of the parallel link mechanism according to an embodiment. 1 and 2, the parallel link mechanism 100 according to the embodiment includes a base 110, a movable section 120, a motor 130, a braking section 140, a switching section 150, a rotating arm 160, a lower joint 170, a link 180, and an upper joint 190. Note that part of the motor 130, the braking section 140, and the switching section 150 are omitted from FIG.

[0009] For the sake of explanation, the direction from the base 110 toward the movable part 120 will be referred to as "up." The opposite direction of "up" will be referred to as "down." These directions are based on the relative positional relationship between the base 110 and the movable part 120 and are unrelated to the direction of gravity. The up-down direction will also be referred to as the "Z direction" (first direction).

[0010] The base 110 and the movable part 120 are spaced apart from each other in the Z direction. The base 110 and the movable part 120 are plate-like members provided along an XY plane (first plane) that intersects with the Z direction. The size of the movable part 120 in the XY plane is smaller than the size of the base 110 in the XY plane. The movable part 120 is movable relative to the base 110 by the motor 130, the rotating arm 160, the lower joint 170, the link 180, the upper joint 190, etc.

[0011] The base 110 has a lower surface 110a and an upper surface 110b that are parallel to the XY plane. The lower surface 110a is fixed to a member different from the parallel link mechanism 100. The upper surface 110b is on the opposite side of the lower surface 110a and faces the movable part 120. A plurality of motors 130 are attached to the upper surface 110b and are provided along the outer periphery (circumferential direction) of the base 110. A drive shaft 131 of each motor 130 extends in a direction that intersects with the Z direction.

[0012] The braking unit 140 and the switching unit 150 are provided between the base unit 110 and the movable unit 120. As shown in Fig. 2, a plurality of motors 130 are provided around the braking unit 140 along the XY plane.

[0013] Fig. 3 is a schematic plan view showing a part of the parallel link mechanism according to the embodiment, and Fig. 4 is a schematic cross-sectional view corresponding to the state shown in Fig. 3. As shown in Figures 2 to 4, the braking part 140 includes an upper plate 141a (first plate), a lower plate 141b (second plate), an upper braking pad 142a (first braking pad), a lower braking pad 142b (second braking pad), a support 143, a cylindrical body 144, and an elastic member 145.

[0014] The upper plate 141a and the lower plate 141b are plate-like members provided along the XY plane. The lower plate 141b is located between the base 110 and the upper plate 141a. The upper brake pad 142a is attached to the outer periphery of the lower surface of the upper plate 141a. The lower brake pad 142b is attached to the outer periphery of the upper surface of the lower plate 141b. The upper brake pad 142a and the lower brake pad 142b are made of a material with high friction, such as rubber.

[0015] The upper brake pad 142a and the lower brake pad 142b face each other in the Z direction. One end of the drive shaft 131 is located between the upper brake pad 142a and the lower brake pad 142b. In the illustrated example, a drum 132 is provided at one end of the drive shaft 131, and the drum 132 is located between the upper brake pad 142a and the lower brake pad 142b. The drum 132 is a cylindrical member that rotates together with the drive shaft 131. The diameter of the drum 132 is larger than the diameter of the drive shaft 131. The drum 132 may be made of metal or the like, or may be made of a high-friction material such as rubber, like the brake pads. The lower surface of the upper brake pad 142a and the upper surface of the lower brake pad 142b are curved to fit the surface of the drum 132. By providing the drum 132, the contact area between the drive shaft 131 and the upper brake pad 142a and the contact area between the drive shaft 131 and the lower brake pad 142b are increased. This increases the braking force of the upper brake pad 142a and the lower brake pad 142b. If the diameter of the drive shaft 131 is sufficiently large, the drum 132 may be omitted.

[0016] As shown in Fig. 4, the lower end of the support pillar 143 is fixed to the base 110. The support pillar 143 extends along the Z direction and penetrates the upper plate 141a and the lower plate 141b. The cylinder 144 is provided around the support pillar 143 and extends along the Z direction like the support pillar 143. The cylinder 144 is slidable relative to the support pillar 143. The upper end of the cylinder 144 is fixed to the upper plate 141a. On the other hand, the lower plate 141b is movable relative to the cylinder 144.

[0017] A stopper 144a that expands toward the side is provided at the lower end of the cylindrical body 144. The stopper 144a is located between the base 110 and the lower plate 141b. An elastic member 145 is provided between the stopper 144a and the lower plate 141b. The elastic member 145 is in a compressed state. Therefore, the elastic member 145 generates an elastic force in a direction that moves the stopper 144a and the lower plate 141b away from each other. The elastic force presses the lower plate 141b toward the upper plate 141a. The elastic force also presses the stopper 144a downward, and the upper plate 141a, which is connected to the cylindrical body 144, toward the lower plate 141b. In other words, the elastic member 145 urges the upper plate 141a and the lower plate 141b in a direction that moves these plates toward each other.

[0018] When braking the motor 130, the upper brake pad 142a and the lower brake pad 142b sandwich the drum 132. The motor 130 is braked by the frictional force between the drum 132 and the upper brake pad 142a and the frictional force between the drum 132 and the lower brake pad 142b. For example, the movement of the drive shaft 131 of the motor 130 comes to a complete halt.

[0019] The switching unit 150 includes a rotating body 151, an actuator 152, a drive shaft 153, and a base 154. The rotating body 151 is located between the upper plate 141a and the lower plate 141b. The rotating body 151 is a plate-shaped member provided along the XY plane. The drive shaft 153 extends in the Z direction. The lower end of the drive shaft 153 is fixed to the center of the rotating body 151 in the XY plane. The upper end of the drive shaft 153 is connected to the actuator 152. When the actuator 152 rotates the drive shaft 153 around the Z direction, the rotating body 151 rotates around the Z direction relative to the motor 130, the braking unit 140, etc.

[0020] The pedestal 154 is provided between the upper plate 141a and the movable part 120. The actuator 152 is placed on the pedestal 154. As shown in Fig. 4, the pedestal 154 is fixed to the upper end of the support 143. The pedestal 154 is fixed to the base 110 via the support 143.

[0021] Fig. 5 is a schematic plan view showing a part of the parallel link mechanism according to the embodiment, and Fig. 6 is a schematic cross-sectional view corresponding to the state shown in Fig. 5. The distance from the rotation center (drive shaft 153) of the rotor 151 to the outer edge of the rotor 151 is not uniform. For example, as shown in FIGS. 3 and 5, the rotor 151 has a polygonal shape when viewed from the Z direction and has multiple corners. In the example shown, the rotor 151 has an equilateral triangular shape with a missing corner. Therefore, as shown in FIGS. 3 to 6, depending on the rotation angle of the rotor 151, there are states in which the rotor 151 contacts the upper plate 141a and the lower plate 141b and states in which the rotor 151 does not contact the upper plate 141a and the lower plate 141b.

[0022] As shown in the figure, the upper plate 141a may include an upper protrusion 146a that protrudes downward. The upper protrusion 146a is located on the inner periphery of the lower surface of the upper plate 141a. The lower plate 141b may include a lower protrusion 146b that protrudes upward. The lower protrusion 146b is located on the inner periphery of the upper surface of the lower plate 141b. The upper protrusion 146a and the lower protrusion 146b face each other in the Z direction. When the rotating body 151 rotates, the rotating body 151 comes into contact with the upper protrusion 146a and the lower protrusion 146b. For example, the inner periphery of the lower surface of the upper protrusion 146a, the inner periphery of the upper surface of the lower protrusion 146b, and the outer circumferential surface of the rotating body 151 are chamfered so that the rotating body 151 can smoothly contact the upper protrusion 146a and the lower protrusion 146b with little friction.

[0023] When the rotating body 151 is not in contact with the upper protrusion 146a and the lower protrusion 146b, the gap between the upper protrusion 146a and the lower protrusion 146b is smaller than the thickness of the rotating body 151. When the rotating body 151 is inserted between the upper protrusion 146a and the lower protrusion 146b, the upper plate 141a and the lower plate 141b move in directions away from each other. This causes the upper brake pad 142a and the lower brake pad 142b to move away from the drum 132. The frictional force between the upper brake pad 142a and the drum 132 and the frictional force between the lower brake pad 142b and the drum 132 decreases, allowing the drive shaft 131 to rotate.

[0024] When the rotating body 151 is removed from between the upper protrusion 146a and the lower protrusion 146b and moves away from the upper protrusion 146a and the lower protrusion 146b, the upper plate 141a and the lower plate 141b move toward each other due to the elastic force of the elastic member 145. This causes the upper brake pad 142a and the lower brake pad 142b to come into contact with the drum 132. The frictional force between each brake pad and the drum 132 increases, braking the drive shaft 131.

[0025] The actuator 152 rotates the rotating body 151 to switch between a contact state in which the upper brake pad 142a and the lower brake pad 142b are in contact with the drive shaft 131 and a non-contact state in which the upper brake pad 142a and the lower brake pad 142b are not in contact with the drive shaft 131.

[0026] In the illustrated example, six motors 130a to 130f are provided. Each motor 130 is adjacent to another motor 130. As shown in FIGS. 3 and 5, pairs P1 to P3 of three adjacent motors 130 are provided. Pair P1 includes motors 130a and 130b. Pair P2 includes motors 130c and 130d. Pair P3 includes motors 130e and 130f. Pairs P1 to P3 are provided at equal intervals around brake unit 140.

[0027] The drive shafts 131a to 131f of the motors 130a to 130f are parallel to the XY plane and extend in a direction from the center to the outer periphery of the base 110. In each pair, the drive shafts 131 of the motors 130 are parallel to each other, and the motors 130 are adjacent to each other in a direction perpendicular to the drive shafts 131.

[0028] The upper plate 141a and the lower plate 141b each have sides S1 to S3 along the direction connecting the pairs of drive shafts 131, and have the shape of an equilateral triangle with a missing corner when viewed from the Z direction. An upper braking pad 142a and a lower braking pad 142b are provided at the positions of the sides S1 to S3, respectively. One pair of drive shafts 131 is sandwiched between one pair of upper braking pads 142a and one pair of lower braking pads 142b. Three sets of support posts 143 and cylinders 144 are provided at the corner positions of the upper plate 141a and the lower plate 141b, respectively.

[0029] As described above, the rotating body 151 has an equilateral triangular shape and has sides S4 to S6. As shown in Fig. 3, in one state of the rotating body 151, sides S4 to S6 are parallel to sides S1 to S3, respectively. Sides S4 to S6 face each pair of drive shafts 131 in the XY plane.

[0030] On the opposite side from the drum 132, a part (first part 161) of the rotating arm 160 is fixed to the drive shaft 131. The rotating arm 160 is driven around the drive shaft 131 by the motor 130. A lower joint 170 is attached to another part (second part 162) of the rotating arm 160. The direction from the first part 161 to the second part 162 intersects with the direction of the drive shaft 131. A bent part 163 is provided between the first part 161 and the second part 162 of the rotating arm 160. The second part 162 is located on the movable part 120 side relative to the first part 161.

[0031] One end of the link 180 is connected to the second portion 162 of the rotating arm 160 via a lower joint 170. The lower joint 170 is, for example, a universal joint having two degrees of freedom. The lower joint 170 includes joints 171 and 172. The joint 171 is fixed to the second portion 162 of the rotating arm 160. The joint 172 is fixed to one end of the link 180. The joint 172 is rotatable relative to the joint 171.

[0032] The other end of the link 180 is connected to the movable part 120 via an upper joint 190. The upper joint 190 is attached to a side surface 120a of the movable part 120. The side surface 120a is inclined with respect to the Z direction and faces upward. The upper joint 190 is, for example, a ball joint having three degrees of freedom. The upper joint 190 includes a ball 191 and a socket 192. The axis of the socket 192 is fixed to the other end of the link 180 and is in spherical contact with the ball 191. The ball 191 is fixed to the side surface 120a. To avoid interference between the socket 192 and the movable part 120 when the angle of the socket 192 changes, the ball 191 is spaced apart from the side surface 120a.

[0033] The multiple links 180 are connected in parallel between the multiple drive shafts 131 and the movable part 120. An end effector is attached to the upper surface 120b of the movable part 120. The side surface 120a is connected to the upper surface 120b. When the drive shaft 131 rotates, the second part 162 of the rotating arm 160 rotates relative to the first part 161. This changes the position and posture of the movable part 120, which is connected to the second part 162 via the links 180.

[0034] As shown in FIG. 1 , a hole 111 may be provided in the base 110. The hole 111 penetrates the base 110 in the Z direction. The hole 111 is used for positioning when fixing the base 110 to another member or for passing wires through. Similarly, a hole 121 may be provided in the movable part 120 for passing wires of the end effector through. The hole 121 penetrates the movable part 120 in the Z direction.

[0035] In the illustrated example, six sets of motors 130, rotating arms 160, lower joints 170, links 180, and upper joints 190 are provided. The pair of rotating arms 160a and 160b are connected to the pair of motors 130a and 130b, respectively, so that their second portions 162 face in opposite directions. Similarly, the pair of rotating arms 160c and 160d are connected to the pair of motors 130c and 130d, respectively, so that their second portions 162 face in opposite directions. The same applies to the other two rotating arms 160.

[0036] A link 180 connected to one of a pair of rotating arms 160 and a link 180 connected to one of another pair of rotating arms 160 are connected to the same side surface 120a. For example, a link 180b connected to rotating arm 160b and a link 180c connected to rotating arm 160c are connected to the same side surface 120a. A link 180a connected to rotating arm 160a and a link 180d connected to rotating arm 160d are each connected to a different side surface 120a. The rotation angles of the six drive shafts 131a to 131f are independently controlled, so that the movable part 120 has six degrees of freedom relative to the base part 110.

[0037] By providing the bent portion 163, the deflection angle of the lower joint 170 can be reduced when the movable portion 120 is in the standard position. By tilting the side surface 120a with respect to the Z direction, the deflection angle of the upper joint 190 can be reduced. For example, the angle of the bent portion 163 is set so that the deflection angle of the lower joint 170 is 0 degrees when the movable portion 120 is in the standard position.

[0038] The advantages of the embodiment will be described. If the power supply is cut off due to a power outage or the like and the control system of the parallel link mechanism 100 stops operating, the parallel link mechanism 100 may move uncontrollably due to inertia, the weight of the end effector, and the like. For safety reasons, in an emergency such as when the power is cut off, it is desirable to stop the movement of the moving part 120. In other words, it is desirable to brake the motor 130. Generally, an emergency brake is provided on the drive shaft to brake the motor in an emergency. The emergency brake includes a braking mechanism and an actuator for operating the braking mechanism, and is provided on each drive shaft.

[0039] Parallel link mechanisms are often miniaturized to allow work in smaller spaces or to avoid interference with other devices. To achieve this, it is desirable to miniaturize the motors and position them closer to each other. However, providing an emergency brake to each motor increases the size of the motor, which in turn increases the size of the parallel link mechanism.

[0040] To address this issue, the parallel link mechanism 100 according to the embodiment includes a brake unit 140 and a switching unit 150. The brake unit 140 is provided inside the multiple motors 130 and includes multiple upper brake pads 142a and multiple lower brake pads 142b that face the multiple drive shafts 131. The switching unit 150 moves the multiple upper brake pads 142a and the multiple lower brake pads 142b collectively by operating an actuator 152. The movement of the multiple upper brake pads 142a and the multiple lower brake pads 142b switches between a contact state in which the brake pads are in contact with the multiple drive shafts 131 and a non-contact state in which the brake pads are separated from the multiple drive shafts 131. The operation of the switching unit 150 allows the multiple drive shafts 131 to be braked collectively. According to the embodiment, there is no need to provide an actuator for driving the brake pads for each motor 130. Therefore, the parallel link mechanism 100 can be made smaller than when an emergency brake is provided for each motor 130.

[0041] In particular, in the parallel link mechanism 100, each drive shaft 131 is provided along a direction from the center of the base 110 toward the outer periphery. One end of each drive shaft 131 is located between the center of the base 110 and the movable part 120. By providing one end of each drive shaft 131 close to each other, the brake pads can also be provided close to each other. This allows the size of the brake part 140 to be reduced. As a result, the parallel link mechanism 100 can be further reduced in size.

[0042] Preferably, the braking unit 140 sandwiches the drive shaft 131 between a pair of brake pads (upper brake pad 142a and lower brake pad 142b) in a direction intersecting the drive shaft 131. By sandwiching the drive shaft 131, it is possible to suppress displacement of the drive shaft 131 when the brake pads come into contact with the drive shaft 131. By suppressing the displacement of the drive shaft 131, the frictional force between the drive shaft 131 and the brake pads is increased, and the drive shaft 131 can be stopped more reliably and more quickly. In addition, it is possible to reduce the load applied to the drive shaft 131, making it less likely that the motor 130 will be damaged.

[0043] The actuator 152 maintains the rotation angle of the rotor 151 so that the non-contact state is maintained during operation of the parallel link mechanism 100. When power is no longer supplied to the actuator 152, the rotor 151 rotates, transitioning from a non-contact state to a contact state. The multiple drive shafts 131 are braked, and operation of the parallel link mechanism 100 stops. For example, the actuator 152 is a rotary actuator. When air is supplied to the actuator 152 through the tube 152a, the drive shaft 153 and rotor 151 rotate to a preset angle, transitioning from a contact state to a non-contact state. When the air supply to the actuator 152 is stopped, the drive shaft 153 and rotor 151 rotate to an initial angle, transitioning from a non-contact state to a contact state.

[0044] FIG. 7 is a schematic diagram showing the configuration of a robot mechanism according to the embodiment. The robot mechanism 1 according to the embodiment includes a parallel link mechanism 100, a manipulator 200, an end effector 300, and a control device 400.

[0045] In the illustrated example, the manipulator 200 is a vertical articulated robot and includes a plurality of links 210 and a plurality of rotary shafts 220 connected in series. One ends of the links 210 are connected to each other by the rotary shafts 220. When the rotary shafts 220 are driven by a motor, one link 210 rotates relative to the other link 210. The manipulator 200 may also be a horizontal articulated robot or a linear motion robot.

[0046] The parallel link mechanism 100 is attached to the tip of the manipulator 200. Specifically, the parallel link mechanism 100 is attached to any part of one end link 210 of the multiple links 210. The other end link 210 of the multiple links 210 is connected to a base 230. The base 230 is fixed to an installation location such as a floor, a wall, or another mechanism. The base 230 houses driving components such as electrical components and motors. As shown in the figure, the control device 400 may be housed in the base 230, or may be provided separately from the base 230.

[0047] The manipulator 200 preferably has four or more degrees of freedom. For example, the manipulator 200 is a vertical articulated robot and has six degrees of freedom. The parallel link mechanism 100 further has six degrees of freedom at the tip of the manipulator 200.

[0048] The control device 400 transmits drive signals to the motors 130, actuators 152, and the like of the parallel link mechanism 100. Each motor 130 is driven in accordance with the drive signal, and the rotation angle of the rotation shaft of each motor 130 is controlled. This controls the position and attitude of the movable part 120 relative to the base part 110. Similarly, the control device 400 transmits drive signals to each motor of the manipulator 200. Each motor is driven in accordance with the drive signal, and the rotation angle of each rotation shaft 220 is controlled. This controls the attitude of the tip of the manipulator 200.

[0049] The control device 400 is connected to the parallel link mechanism 100 and the manipulator 200 via wired communication, wireless communication, or a network. The control device 400 may include multiple control units. For example, there may be provided another control unit (another robot controller) that controls the parallel link mechanism 100, another control unit (robot controller) that controls the manipulator 200, and yet another control unit that transmits and receives data to and from these control units. These control units are connected to each other via wired communication, wireless communication, or a network.

[0050] The control device 400 also controls the end effector 300 in accordance with the functions of the end effector 300. For example, the end effector 300 includes a welding device for performing spot resistance welding. Alternatively, the end effector 300 may include an ultrasonic transmitter / receiver (transducer) for inspecting welded portions obtained by spot resistance welding.

[0051] Fig. 8(a) is a schematic diagram showing the movement of a robot mechanism according to a reference example, and Fig. 8(b) is a schematic diagram showing the movement of a robot mechanism according to an embodiment. In a robot mechanism 1r according to a reference example shown in FIG. 8(a), an end effector 300 is directly attached to the tip of a manipulator 200. When the robot mechanism 1r is in operation, the posture of the end effector 300 can be finely adjusted. For example, as shown in FIG. 8(a), the manipulator 200 moves from the state indicated by the solid line to the state indicated by the dashed line. In this case, the movement of the portion enclosed by the dotted circle is particularly large, so there is a possibility that the robot mechanism 1r will interfere with other members.

[0052] On the other hand, in the robot mechanism 1 according to the embodiment shown in FIG. 8(b), an end effector 300 is attached to the tip of a manipulator 200 via a parallel link mechanism 100. When the posture of the end effector 300 is adjusted, the parallel link mechanism 100 operates to adjust the posture of the end effector 300. By operating the parallel link mechanism 100, or by combining the operations of the manipulator 200 and the parallel link mechanism 100, the movement of the manipulator 200 can be reduced, as shown in FIG. 8(b). This reduces the possibility of the robot mechanism 1 interfering with other members.

[0053] According to the embodiment, the movement of the manipulator 200 can be reduced, so that the robot mechanism 1 can operate more safely even in an environment where other devices are installed nearby or where multiple robot mechanisms 1 are arranged side by side. In this way, the parallel link mechanism 100 according to the embodiment is particularly suitable for combination with the manipulator 200.

[0054] (First Modification) 9 and 10 are schematic cross-sectional views showing a part of a parallel link mechanism according to a first modified example of the embodiment. 9 and 10, a switching unit 150a is provided instead of the switching unit 150. The switching unit 150a includes a base 154, an actuator 155, a link 156, a link 157, and an intermediate plate 158.

[0055] The actuator 155 is, for example, an air cylinder. The actuator 155 includes a cylinder 155a and a piston 155b. The piston 155b slides in the Z direction in response to the pressure inside the cylinder 155a. The upper plate 141a is fixed to the piston 155b.

[0056] One end 156a of link 156 is rotatably connected to upper plate 141a. The position of one end 156a relative to upper plate 141a is fixed. The other end 156b of link 156 is slidably connected to lower plate 141b along the XY plane. One end 157a of link 157 is rotatably connected to lower plate 141b. The position of one end 157a relative to lower plate 141b is fixed. The other end 157b of link 157 is slidably connected to upper plate 141a along the XY plane.

[0057] The intermediate plate 158 is provided between the upper plate 141a and the lower plate 141b. The position of the intermediate plate 158 in the Z direction is the same as the position of the drive shaft 131 in the Z direction. The links 156 and 157 are connected to each other in an X-shape. Specifically, the center of the link 156 and the center of the link 157 are rotatably connected to each other by the shaft 158a. The intermediate plate 158 is also provided with a hole 158b extending along the XY plane. The shaft 158a is passed through the hole 158b. This fixes the position of the shaft 158a in the Z direction. The shaft 158a is also slidable within the hole 158b along the XY plane. The intermediate plate 158 is fixed to the base 110 by a support 158c. Even when the actuator 155 operates, the intermediate plate 158 does not move, and the position of the shaft 158a in the Z direction does not change.

[0058] As shown in FIG. 9, when the actuator 155 operates and the piston 155b moves downward, the upper plate 141a moves downward. When the upper plate 141a approaches the intermediate plate 158, the links 156 and 157 rotate relative to the upper plate 141a, and the lower plate 141b also approaches the intermediate plate 158. That is, the lower plate 141b moves in conjunction with the upper plate 141a. As the upper plate 141a and the lower plate 141b move, the upper brake pad 142a and the lower brake pad 142b come into contact with the drum 132, braking the motor 130. Furthermore, the elastic member 145 pushes up the lower plate 141b, thereby pressing the upper brake pad 142a and the lower brake pad 142b against the drum 132 with greater force. This increases the braking force.

[0059] 10, when actuator 155 operates and piston 155b moves upward, upper plate 141a moves upward. When upper plate 141a moves in a direction away from intermediate plate 158, links 156 and 157 rotate relative to upper plate 141a, and lower plate 141b also moves in a direction away from intermediate plate 158. As a result, upper brake pad 142a and lower brake pad 142b move away from drum 132, and drive shaft 131 becomes rotatable.

[0060] (Second Modification) 11 and 12 are schematic cross-sectional views showing a part of a parallel link mechanism according to a second modified example of the embodiment. 11 and 12, a switching unit 150b is provided instead of the switching unit 150. The switching unit 150b includes a base 154, an upper pressure-receiving surface 159a, a lower pressure-receiving surface 159b, a fixing ring 159c, an expandable member 159d, a tube 159e, and a support 159f.

[0061] The upper pressure receiving surface 159a, the lower pressure receiving surface 159b, the fixing ring 159c, and the expandable member 159d are provided between the upper plate 141a and the lower plate 141b. The upper pressure receiving surface 159a and the lower pressure receiving surface 159b are plate-shaped members extending along the XY plane. The upper pressure receiving surface 159a contacts the upper plate 141a. The upper pressure receiving surface 159a may be fixed to the upper plate 141a. The lower pressure receiving surface 159b contacts the lower plate 141b. The lower pressure receiving surface 159b may be fixed to the lower plate 141b. The fixing ring 159c is located between the upper pressure receiving surface 159a and the lower pressure receiving surface 159b. The fixing ring 159c is an annular member provided along the XY plane.

[0062] The elastic member 159d is provided between the upper pressure-receiving surface 159a and the fixed ring 159c and between the lower pressure-receiving surface 159b and the fixed ring 159c. The elastic member 159d is expandable and contractible along the Z direction. In the illustrated example, the elastic member 159d has a bellows structure. The elastic member 159d may be made of elastic rubber or the like. The internal space surrounded by the upper pressure-receiving surface 159a, the lower pressure-receiving surface 159b, the fixed ring 159c, and the elastic member 159d is airtight. The tube 159e is connected to the internal space.

[0063] The fixing ring 159c is fixed to the base 154 via a support 159f. The position of the fixing ring 159c in the Z direction is the same as the position of the drive shaft 131 in the Z direction. The upper pressure-receiving surface 159a and the lower pressure-receiving surface 159b move in the Z direction depending on the pressure in the internal space. The expandable member 159d deforms in accordance with the movement of the upper pressure-receiving surface 159a and the lower pressure-receiving surface 159b. When the internal space is decompressed through the tube 159e, as shown in FIG. 11, the elastic force of the elastic member 145 causes the upper plate 141a to move upward and the lower plate 141b to move downward. The upper brake pad 142a and the lower brake pad 142b come into contact with the drum 132, braking the motor 130.

[0064] When the internal space is pressurized through the tube 159e, the upper pressure-receiving surface 159a moves upward and the lower pressure-receiving surface 159b moves downward, as shown in Fig. 12. The upper pressure-receiving surface 159a pushes up the upper plate 141a, and the lower pressure-receiving surface 159b pushes down the lower plate 141b. This causes the upper brake pad 142a and the lower brake pad 142b to separate from the drum 132, allowing the drive shaft 131 to rotate.

[0065] As described above, the specific configuration for moving the upper brake pad 142a and the lower brake pad 142b can be changed as appropriate. In any configuration, there is no need to provide an actuator for driving the brake pad for each motor 130, and the parallel link mechanism can be made smaller. Furthermore, in the robot mechanism 1 shown in FIG. 7, parallel link mechanism 100a or 100b may be provided instead of parallel link mechanism 100. Even in this case, the movement of the manipulator 200 can be reduced, allowing the robot mechanism 1 to operate more safely.

[0066] When further miniaturization is the goal, the parallel link mechanism 100 is particularly preferable to the parallel link mechanisms 100a and 100b. In the parallel link mechanism 100, the upper braking pad 142a and the lower braking pad 142b can be moved simply by rotating the rotor 151. The parallel link mechanism 100 can have a simpler structure and be smaller in size than the link mechanism of the parallel link mechanism 100b and the balloon mechanism of the parallel link mechanism 100c.

[0067] Although several embodiments of the present invention have been described above, these embodiments are presented by way of example only and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, modifications, etc. can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, as well as within the scope of the invention and its equivalents as set forth in the claims. Furthermore, the above-described embodiments can be implemented in combination with each other. [Explanation of symbols]

[0068] 1, 1r: robot mechanism, 100, 100a to 100c: parallel link mechanism, 110: base, 110a: lower surface, 110b: upper surface, 111: hole, 120: moving part, 120a: side surface, 120b: upper surface, 121: hole, 130, 130a to 130f: motor, 131, 131a to 131f: drive shaft, 132: drum, 140: braking part, 141a: upper plate, 141b: lower plate, 142a: upper braking pad, 142b: lower braking pad, 143: support, 144: cylinder, 144a: stopper, 145: elastic member, 146a: upper protrusion, 146b: lower protrusion, 150: switching part, 151: Rotating body, 152: Actuator, 153: Drive shaft, 154: Base, 155: Actuator, 155a: Cylinder, 155b: Piston, 156: Link, 156a: One end, 156b: Other end, 157: Link, 157a: One end, 157b: Other end, 158: Intermediate plate, 158a: Shaft, 158b: Hole, 158c: Support, 159a: Upper pressure receiving surface, 159b: Lower pressure receiving surface, 159c: Fixing ring, 159d: Expandable member, 159e: Tube, 159f: Support, 160, 160a to 160d: Rotating arm, 161: First part, 162: Second part, 163: Bending portion, 170: Lower joint, 171: joint, 172: joint, 180, 180a to 180d: link, 190: upper joint, 191: ball, 192: socket, 200: manipulator, 210: link, 220: rotation axis, 230: base, 300: end effector, 400: control device, P1 to P3: pair, S1 to S6: side

Claims

1. A base and a movable portion spaced apart from the base portion in a first direction; a braking section provided between the base section and the movable section and including a plurality of braking pads; a plurality of motors provided around the braking unit, each of the motors including a drive shaft extending along a direction intersecting the first direction; a plurality of links respectively connected between the plurality of drive shafts and the movable portion; a switching unit provided between the base unit and the movable unit, which switches between a contact state in which the brake pads are in contact with the drive shafts and a non-contact state in which the brake pads are separated from the drive shafts by moving the brake pads collectively; A parallel link mechanism equipped with

2. The plurality of brake pads include: a plurality of first brake pads; a plurality of second brake pads respectively facing the plurality of first brake pads in the first direction; Including, 2. The parallel link mechanism according to claim 1, wherein in the contact state, the plurality of drive shafts are sandwiched between the plurality of first brake pads and the plurality of second brake pads, respectively.

3. The braking portion is a first plate extending along a first plane intersecting the first direction; a second plate extending along the first surface and positioned between the base and the first plate; Including, the plurality of first brake pads and the plurality of second brake pads are located between the first plate and the second plate; the plurality of first brake pads are attached to the first plate; The parallel link mechanism according to claim 2 , wherein the plurality of second brake pads are attached to the second plate.

4. The parallel link mechanism according to claim 3 , wherein the switching unit switches between the contact state and the non-contact state by changing a distance between the first plate and the second plate.

5. the switching portion includes a rotor located between the first plate and the second plate and rotating around the first direction, the rotating body is inserted between a portion of the first plate and a portion of the second plate, and the first plate and the second plate move in directions away from each other, thereby transitioning from the contact state to the non-contact state; 5. The parallel link mechanism according to claim 3, wherein the rotating body is removed from between the portion of the first plate and the portion of the second plate, and the first plate and the second plate move in directions toward each other, thereby transitioning from the non-contact state to the contact state.

6. 6. The parallel link mechanism according to claim 1, wherein each of the plurality of drive shafts is provided along a direction from a center of the base portion toward an outer periphery thereof.

7. 7. The parallel link mechanism according to claim 1, wherein when no power is supplied to the switching unit, the plurality of brake pads are in the non-contact state.

8. The parallel link mechanism according to any one of claims 1 to 7, wherein the base is attached to a tip of a manipulator.

9. A manipulator, The parallel link mechanism according to any one of claims 1 to 7, wherein the base is attached to a tip of the manipulator; A robot mechanism equipped with

10. 10. The robotic mechanism of claim 9, further comprising an end effector attached to the moving part.

11. A braking method for a parallel link mechanism in which the drive shafts of multiple motors arranged circumferentially are clamped between multiple braking pads on a pair of plates provided inside the multiple motors, thereby braking the multiple motors collectively.

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