JP6043561B2 - Parallel link robot - Google Patents

Description

  The present invention relates to a parallel link robot configured by combining a plurality of actuators and a link mechanism, and used for operations such as processing and assembly of articles.

  The parallel link robot is provided with a link mechanism as an arm between a plurality of actuators supported by a fixed member serving as a base and an output member. A plurality of actuators are driven to control the position and posture of the output member connected to the tip of each link and the end effector attached to the output member.

  For example, a structure in which links constituting three arms driven by a driving mechanism (actuator) are connected to a manipulator (output member) using joint devices each having three degrees of freedom has been proposed (Patent Document 1). reference).

Japanese Patent No. 4901557

  However, in the case of the structure described in Patent Document 1 described above, since the manipulator is not constrained against rotation around the output shaft, the direction of the end effector attached to the manipulator changes depending on the movement position. That is, since the three arms are connected to the manipulator by the joint device having three degrees of freedom, the rotation of the manipulator is not restricted. For this reason, when the manipulator is moved using three arms, the rotation angle (direction) of the manipulator changes before and after the movement. If the direction of the manipulator changes depending on the movement position in this way, it is difficult to carry or position the workpiece as a robot operation.

  In view of such circumstances, the present invention has been invented to realize a structure capable of keeping the orientation of the output member constant regardless of the movement position of the output member.

The present invention includes an output member having an output shaft, first and second actuators for moving the output member in a direction orthogonal to the axial direction of the output shaft, and the output member in the axial direction of the output shaft. A third arm for moving the output member and the first actuator by a parallel link structure, and a first arm for connecting the output member and the second actuator by a parallel link structure. Two arms and a third arm that connects the output member and the third actuator by a parallel link structure, and each of the first arm and the second arm is parallel to the axial direction of the output shaft. It has a link shaft part that becomes a central shaft, and is connected to be rotatable about the axis of the link shaft part by the first joint parts provided at both ends of the link shaft part Is one, parallel robot, wherein the first directly to the output member by a second joint unit and a direction orthogonal to the rotation axis of the joint portions as a rotation axis, is rotatably connected, it It is in.

According to the present invention, the direction of the output member can be kept constant regardless of the movement position of the output member .

BRIEF DESCRIPTION OF THE DRAWINGS The schematic structure of the parallel link robot which concerns on the 1st Embodiment of this invention is shown, (a) is a front view, (b) is a side view. Similarly, (a) shows a schematic configuration of a parallel link robot, and (b) is an enlarged perspective view of a configuration around an output member. (A) is an enlarged perspective view of an example of a joint portion with two degrees of freedom, and (b) is a schematic diagram showing a state in which a bridge member is bridged over two links in a configuration using a joint portion with three degrees of freedom. . The block diagram which shows a part of control system of the parallel link robot which concerns on 1st Embodiment. The figure which shows an example of the pulse signal of the 2 phase excitation system output to a stepping motor in 1st Embodiment. The perspective view which shows schematic structure of the parallel link robot which concerns on the 2nd Embodiment of this invention. Similarly, the schematic structure of a parallel link robot is shown, (a) is a front view, (b) is a plan view. The structure of a rod end bearing is shown, (a) is a top view, (b) is sectional drawing. Sectional drawing for demonstrating the restriction | limiting of the inclination-angle of a rod end bearing. The perspective view which expands and shows the structure around the output member of 2nd Embodiment. The schematic structure of the parallel link robot which concerns on the 3rd Embodiment of this invention is shown, (a) is a front view, (b) is a side view. The perspective view of the parallel link robot which shows two examples of the state which moved the output member in 3rd Embodiment. The top view which cut | disconnects and shows a part of parallel link robot of 3rd Embodiment. The perspective view which expands and shows the structure around the output member of 3rd Embodiment.

<First Embodiment>
A first embodiment of the present invention will be described with reference to FIGS. As shown in FIGS. 1 and 2, the parallel link robot 100 includes a base member 100A as a fixed member, an output member 103, a plurality of motors 107, 108, 111, a plurality of arms 109, 110, 112, Have The first motor 107 corresponds to a first actuator, the second motor 108 corresponds to a second actuator, and the third motor 111 corresponds to a third actuator. 109 corresponds to the first arm, 110 corresponds to the second arm, and 112 corresponds to the third arm.

  The base member 100A includes a horizontal plate 101 arranged in a substantially horizontal direction and a vertical plate 102 provided in a substantially vertical direction from the horizontal plate 101, and supports the plurality of motors 107, 108, and 111 described above. The plurality of motors 107, 108, 111 are respectively fixed at predetermined positions on the vertical plate 102. In the present embodiment, the third motor 111 is located above the vertical center of the vertical plate 102 in the vertical direction, and the first motor 107 and the second motor 107 are respectively disposed on both sides of the vertical direction intermediate portion of the vertical plate 102 across the width direction center. A motor 108 is disposed. A workpiece or the like is disposed on the horizontal plate 101.

  The output member 103 is a manipulator for mounting an end effector 104 such as a robot hand that holds and moves a workpiece. A link mechanism constituting a plurality of arms, which will be described later, is coupled to the output member 103, and an output shaft (output shaft portion) 105 that supports the end effector 104 is provided coaxially.

  A connecting member 131 is fixed to the output shaft 105 with a knock pin or the like. Further, the connecting member 131 is separated from the axis of the output shaft 105 and is parallel to the output shaft 105. The second shaft 133 (second shaft portion) is fixed with a knock pin or the like. Thereby, the output shaft 105, the first shaft 132, and the second shaft 133 are always kept parallel with a predetermined interval (offset). The offset amounts (inter-axis distances) of the first shaft 132 and the second shaft 133 from the output shaft 105 are the same. In other words, the first shaft 132 and the second shaft 133 are arranged symmetrically about the output shaft 105.

  A third shaft (third shaft portion) 106 that intersects with the output shaft 105 is fixed to the connecting member 131 with a knock pin or the like. In the present embodiment, the third shaft 106 is disposed substantially parallel to the vertical plate 102 and is orthogonal to the output shaft 105. The output shaft 105, the first shaft 132, and the second shaft 133 are disposed in a substantially vertical direction, and the third shaft 106 is disposed in a substantially horizontal direction. Further, the upper end of the output shaft 105 in the vertical direction is coupled to the central portion in the horizontal direction of the third shaft 106 via the connecting member 131. The output shaft 105 and the third shaft 106 may be directly coupled. The output shaft 105 preferably has a shaft shape, but may not actually have a shaft shape, and may have a shape integrated with the connecting member 131.

[Positioning of output member]
First, a configuration for positioning the output member 103 by the parallel link robot 100 will be described with reference to FIGS. 1 to 3. The first arm 109 and the second arm 110 are disposed between the output member 103 and the first motor 107 and between the output member 103 and the second motor 108, respectively. The first arm 109 and the second arm 110 hold the output member 103 from both sides. The output member 103 is moved in a direction (substantially horizontal direction) intersecting the output shaft 105 by driving the first motor 107 and the second motor 108. Strictly speaking, when the third motor 111 is stopped, the output member 103 is moved on a virtual spherical surface by the first motor 107 and the second motor 108.

  The third arm 112 is provided between the output member 103 and the third motor 111. The third arm 112 holds the output member 103 from above in the vertical direction. Then, the output member 103 is moved in a direction substantially parallel to the output shaft 105 by driving the third motor 111. Strictly speaking, when the first motor 107 and the second motor 108 are stopped, the output member 103 moves on a virtual arc by driving the third motor 111. The output member 103 can be positioned in a predetermined space by driving the first motor 107, the second motor 108, and the third motor 111. The first arm 109, the second arm 110, and the third arm 112 constitute a holding unit that holds the posture of the output member 103. Further, the holding means and the output member 103 constitute a parallel link structure. More specific description will be given below.

  The first motor 107 as a first actuator is a rotary actuator that positions the first link shaft 107b by rotating the first rotating arm 107a in a substantially horizontal direction. The second motor 108 as a second actuator is a rotary actuator that positions the second link shaft 108b by rotating the second rotary arm 108a in a substantially horizontal direction. In this embodiment, the length of the 1st rotation arm 107a and the length of the 2nd rotation arm 108a are made the same. The positions of the first rotating arm 107a and the second rotating arm 108a in the direction parallel to the output shaft 105 are also the same.

  The first link shaft 107b and the second link shaft 108b are substantially parallel to the rotation shaft of the first motor 107 and the rotation shaft of the second motor 108, respectively, and cannot be tilted. It is provided at the tip of the two-rotating arm 108a. In the present embodiment, since the rotation shafts of the first motor 107 and the second motor 108 are arranged substantially parallel to the output shaft 105, the first link shaft 107b and the second link shaft 108b are also substantially the same as the output shaft 105. Arranged in parallel.

  The first arm 109 includes a plurality of first links 109 a that are spaced apart in a direction parallel to the output shaft 105 and arranged in parallel with each other. In the present embodiment, the first arm 109 is constituted by two first links 109a having the same length. Such a first arm 109 has one end rotated with respect to the output member 103 around the axis parallel to the output shaft 105 (first shaft 132), and the first shaft 132 and the first arm 109. They are connected in a state having two degrees of freedom that allows rotation about an axis orthogonal to the arrangement direction. Further, the other end is connected to a first link shaft 107 b provided in a non-tiltable manner on a first rotating arm 107 a serving as a drive unit of the first motor 107. Thereby, the 1st arm 109 comprises the parallel link mechanism.

  Specifically, each of the two first links 109a has one end connected to a first shaft 132 parallel to the output shaft 105 that supports the end effector 104 with a joint portion 109b having two degrees of freedom, and the other end connected to the first shaft 109a. It is connected to one link shaft 107b by a joint portion 109c with two degrees of freedom. Here, the joint portion 109c can be rotated around the first link shaft 107b, and can be rotated around an axis orthogonal to the arrangement direction of the first link shaft 107b and the first link 109a. is there. That is, both ends of the two first links 109a are connected to the first shaft 132 and the first link shaft 107b with two degrees of freedom, respectively. The first shaft 132, the first link shaft 107b, and the two first links 109a constitute a parallel link mechanism.

  The second arm 110 is composed of a plurality of second links 110 a that are spaced apart in a direction parallel to the output shaft 105 and arranged in parallel to each other. In the present embodiment, the second arm 110 is constituted by two second links 110a having the same length. The length of the two second links 110a is the same as the length of the two first links 109a of the first arm 109. In such a second arm 110, one end of the second arm 110 rotates around the axis (second axis 133) parallel to the output shaft 105 with respect to the output member 103, and the second axis 133 and the second arm 110 They are connected in a state having two degrees of freedom that allows rotation about an axis orthogonal to the arrangement direction. Further, the other end is connected to a second link shaft 108b provided in a non-tiltable manner on a second rotating arm 108a as a drive unit of the second motor 108.

  Specifically, each of the two second links 110a has one end connected to a second shaft 133 parallel to the output shaft 105 that supports the end effector 104 by a joint portion 110b having two degrees of freedom, and the other end connected to the second link 110a. The two link shafts 108b are connected by a joint part 110c having two degrees of freedom. Here, the joint portion 110c can rotate around the second link shaft 108b and can rotate around an axis orthogonal to the direction in which the second link shaft 108b and the second link 110a are disposed. is there. That is, the two second links 110a have both ends connected to the second shaft 133 and the second link shaft 108b with two degrees of freedom, respectively. The second shaft 133, the second link shaft 108b, and the two second links 110a constitute a parallel link mechanism. In addition, the joint portion 110b that connects the two second links 110a to the second shaft 133 includes the joint portion 109b that connects the two first links 109a of the first arm 109 to the first shaft 132, and the output shaft 105. Are arranged at the same position in the direction parallel to the.

  With this configuration, the output shaft 105 that supports the end effector 104 and the first link shaft 107b and the second link shaft 108b that are provided so as not to tilt are always kept parallel. The posture (inclination) of the end effector 104 is held constant (substantially in the vertical direction) regardless of the position of the first rotating arm 107a and the second rotating arm 108a.

  The third motor 111 as the third actuator is a rotary actuator that positions the third link shaft 111b by rotating the third rotating arm 111a in a substantially vertical direction. The third link shaft 111b is provided at the tip of the third rotating arm 111a so as to be substantially parallel to the rotating shaft of the third motor 111 and not tiltable. In the present embodiment, since the rotation shaft of the third motor 111 is disposed substantially parallel to the third shaft 106, the third link shaft 111 b is also disposed substantially parallel to the third shaft 106.

  The third arm 112 includes a plurality of third links 112a that are spaced apart from each other in a direction parallel to the third shaft 106 and arranged in parallel with each other. In the present embodiment, the third arm 112 is constituted by two third links 112a having the same length. Such a third arm 112 has one end pivoted around the third shaft 106 with respect to the output member 103 and an axis orthogonal to the arrangement direction of the third shaft 106 and the third arm 112. It is connected in a state having two degrees of freedom that allows rotation around the center. Further, the other end is connected to a third link shaft 111 b provided in a non-tiltable manner on a third rotating arm 111 a as a drive unit of the third motor 111. Thereby, the 3rd arm 112 comprises the parallel link mechanism.

  Specifically, one end of each of the two third links 112a is connected to the third shaft 106 by a two-degree-of-freedom joint portion 112b, and the other end is connected to the third link shaft 111b by a two-degree-of-freedom joint portion 112c. Connected with. Here, the joint portion 112c can rotate around the third link shaft 111b, and can rotate around an axis orthogonal to the direction in which the third link shaft 111b and the third link 112a are disposed. is there. The pair of third links 112a of the third arm 112 are connected at symmetrical positions in the horizontal direction from the portion where the output shaft 105 of the third shaft 106 is joined.

  That is, the two third links 112a have both ends connected to the third shaft 106 and the third link shaft 111b with two degrees of freedom. The third shaft 106, the third link shaft 111b, and the two third links 112a constitute a parallel link mechanism. As a result, the third shaft 106 that supports the end effector 104 and the third link shaft 111b provided so as not to tilt are always kept parallel. Then, no matter which position the third rotating arm 111a rotates, the rotation of the end effector 104 around the output shaft 105 is constrained and the orientation is kept constant.

  The two-degree-of-freedom joint portions 109b, 109c, 110b, 110c, 112b, and 112c illustrated as circular joints in FIGS. 1 and 2 preferably have the structure illustrated in FIG. In the joint portion of FIG. 3 (a), the degree of freedom of rotation about one or more rotations around the support shaft indicated by arrow A and rotation within a predetermined angle range indicated by arrow B with the axis perpendicular to the support shaft as the rotation axis. Has the freedom to move. These joint portions have no functional problem as long as they have at least two degrees of freedom, but joints having three degrees of freedom such as a ball joint and a rod end joint may be used. Thereby, it is possible to make the joint part itself compact. However, in this case, as shown in FIG. 3B, bridge members 201 and 202 are required as restricting members for restricting rotation around the axis of the link in order to prevent twisting of the parallel link mechanism. .

  The bridge members 201 and 202 are disposed near both ends of the two links 203 and 204 so as to be spanned by the two links 203 and 204, respectively. Such bridge members 201 and 202 have axes orthogonal to the links 203 and 204, respectively, and are connected to the links 203 and 204 by rotatably supporting the links 203 and 204 on the axes. This prevents rotation of the link around its axis and allows the two links to move relative to each other in the arrangement direction. And even if two links are connected by a joint part with three degrees of freedom, the degree of freedom around the link axis is constrained, and as a result, an arm composed of two links is connected with two degrees of freedom. can do. Since the two links are relatively movable in the arrangement direction, the two links are maintained in a parallel state and are orthogonal to the axis to which the two links are connected and the arrangement direction of the links. Rotation around the axis is possible.

  For example, each of the two third links 112a constituting the third arm 112 can rotate about the axis of the third link 112a with respect to the output member 103 in addition to the two degrees of freedom described above. Connect with a degree of freedom. In this case, the two third links 112a can be moved relative to each other in the direction in which the third arm 112 is disposed, and the rotation of the respective third links around the axis is made impossible. The members 201 and 202 are spanned. Accordingly, the third arm 112 is connected to the output member 103 and the third link shaft 111b with two degrees of freedom. The same applies to the first arm 109 and the second arm 110.

  In the present embodiment, the angle formed between the output shaft 105 and the third shaft 106 is 90 degrees and is orthogonal to each other, but may be three-dimensionally orthogonal or limited to 90 degrees. Instead, they may be arranged at a predetermined angle.

  Thus, in this embodiment, the end effector 104 attached to the output member 103 is formed by the parallel link mechanism formed by the first arm 109 and the second arm 110 and the parallel link mechanism formed by the third arm 112. It is supported to maintain both a constant posture (tilt) and orientation.

  In the case of this embodiment configured as described above, the output member 103 is substantially horizontal by driving the first rotating arm 107a by the first motor 107 and driving the second rotating arm 108a by the second motor 108. Move in the direction. Further, when the output member 103 is moved in the vertical direction by driving the third rotating arm 111a by the third motor 111, the first arm 109 and the second arm 110 are displaced from the horizontal. For this reason, the position of the output member 103 in the three-dimensional space (predetermined space) is determined by considering the inclination of the first arm 109 and the second arm 110 and the driving amount of the first, second, and third rotary arms Can be calculated geometrically from Further, it is possible to calculate the driving amounts of the first, second, and third motors from the spatial position coordinates of the output member 103 by calculation of inverse kinematics.

[Stepping motor]
In the present embodiment, the above-described first motor 107 (first actuator), second motor 108 (second actuator), and third motor 111 (third actuator) are stepping motors. That is, all actuators that drive the output member 103 are stepping motors. In the stepping motor of this embodiment, the rotor is formed from a permanent magnet, and the stator is formed from a winding. And a rotor is rotated by applying an electric current to a winding with a predetermined pulse.

  Such a stepping motor of this embodiment will be described with reference to FIGS. In FIG. 4, reference numeral 11 denotes a stepping motor for driving the output member 103 of the parallel link robot, and corresponds to the first motor 107, the second motor 108, and the third motor 111. A control device 12 outputs an operation command to the stepping motor 11 and is connected to the stepping motor 11 via the motor driver 13. The motor driver 13 includes a power transistor 15 for driving the stepping motor 11 and a signal output port 14 that receives a command from the control device 12 and outputs a pulse signal at a predetermined timing.

  When the stepping motor 11 outputs the pulse signals p1 to p4 shown in FIG. 5 from the signal output port 14 in response to a command from the control device 12, the stepping motor 11 sets the step angle by the power transistor 15 receiving the pulse signals p1 to p4. It is driven to rotate as a unit. The stepping motor 11 driven in this manner does not hunt when the rotation amount is lowered, and can maintain the position with a high holding torque when stopped.

  A more specific description will be given with reference to FIGS. 1 and 2. The parallel link robot 100 may control the rotation amounts of the first motor 107, the second motor 108, and the third motor 111 in cooperation in order to translate the output member 103.

  For example, in the operation of moving the position of the output member 103 from the current position Xn to the target position Xn + 1, if the first, second, and third motors 107, 108, and 111 are driven by a necessary amount, the first, second, and second The three arms 109, 110, and 112 move the position of the output member 103 in cooperation. The operation cannot be performed unless the driving amounts of the first, second, and third motors 107, 108, and 111 become zero at the same time as the position of the output member 103 reaches the target position Xn + 1. Accordingly, by using the first motor 107, the second motor 108, and the third motor 111 as stepping motors, the hunting is not performed when the rotation amount is lowered, and the driving amounts of the first, second, and third motors 107, 108, and 111 are increased. Without being affected, the position of the output member can be settled on demand. Therefore, in the parallel link robot, there is an effect of improving the reliability of precise work including a minute operation that changes the posture while holding the position of the output member.

  As described above, in the present embodiment, the first motor 107, the second motor 108, and the third motor 111 that drive the output member 103 are stepping motors. The stepping motor does not hunt when the rotation amount is lowered, and can maintain the position with a high holding torque when stopped. For this reason, the position and posture of the output member 103 can be settled as required without being affected by the driving amount of the motor, and the minute operation and posture for changing the posture while holding the position can be held. Thus, it is possible to provide a parallel link robot including a minute operation for moving the position while improving the reliability of precise work.

  In the above description, the control system of the parallel link robot has been described as open loop control. However, the control system may be realized by appropriately combining semi-closed or closed loop control. The pulse signal is not limited to the two-phase excitation method.

  In the case of the present embodiment, the third motor 111 that moves the output member 103 in the vertical direction is a stepping motor whose rotor is constituted by a permanent magnet. For this reason, even if the power supply to the third motor 111 is interrupted, the output member 103 can be prevented from dropping by cogging. That is, even when the power supply to the third motor 111 is interrupted, cogging occurs due to the magnetic force acting between the permanent magnets constituting the rotor and the stator, and at least the speed at which the output member 103 falls is slowed down. Or it can be prevented from falling. As a result, it is possible to prevent the output member 103 from dropping suddenly without providing an electromagnetic brake, and it is possible to prevent the work held by the output member 103 from colliding with the stage or the like and being damaged. In this embodiment, it is not necessary to provide an electromagnetic brake as described above, and since an inexpensive stepping motor is used, the cost of the parallel link robot can be reduced.

  In the present embodiment, all the motors that drive the output member 103 are stepping motors, but at least the third motor 111 is stepped in order to suppress the drop of the output member 103 when the energization is interrupted. Any motor can be used. Further, when the arrangement or the like of each motor is changed and the output member is moved in the vertical direction by a plurality of motors, these plurality of motors are set as stepping motors. In short, a stepping motor is a motor that can support the vertical movement of the output member by stopping driving.

  In the case of this embodiment configured as described above, the posture and orientation of the output member 103 can be kept constant regardless of the movement position of the output member 103 as described above. In other words, by performing positioning control of the output member 103 with the above-described configuration, the end effector 104 can be moved while maintaining the posture (tilt) and orientation of the end effector 104 attached to the output member 103.

  In the case of this embodiment, since the two parallel link mechanisms formed by the first arm 109 and the second arm 110 are connected to the output member 103 at a position off the axis of the output shaft 105, the output member 103 is compact. Can be realized. In particular, in the present embodiment, the joint portion 109b that connects the two first links 109a to the first shaft 132 and the joint portion 110b that connects the two second links 110a to the second shaft 133 are the output shaft 105. Are arranged at the same position in the direction parallel to the. For this reason, the dimension of the direction parallel to the output shaft 105 can be shortened, and the output member 103 can be made compact.

  That is, when the two parallel link mechanisms formed by the first arm 109 and the second arm 110 are connected on the axis of the output shaft 105, the respective joint portions need to be shifted in the axial direction. turn into. As a result, the robot body including the end effector attached to the output member 103 is enlarged, and the workability of the robot by the end effector is also reduced.

  On the other hand, in the case of this embodiment, the first arm 109 and the second arm 110 are connected to the first shaft 132 and the second shaft 133 that are off the axis of the output shaft 105, respectively, so that the output member 103 is made compact. Can be planned. And the workability | operativity of a robot can be improved and a compact parallel link robot can be provided.

  Further, in the present embodiment, the first shaft 132 and the second shaft 133 are arranged symmetrically about the output shaft 105, and the length of the first rotating arm 107a and the length of the second rotating arm 108a are the same. The length of the two second links 110a and the length of the two first links 109a of the first arm 109 are the same. For this reason, driving can be transmitted from the first motor 107 and the second motor 108 to the output member 103 in a balanced manner, and the positioning accuracy can be further improved.

<Second Embodiment>
A second embodiment of the present invention will be described with reference to FIGS. The difference from the first embodiment described above is the configuration of the joint portion between each arm 109, 110, 112 and the output member 103. For this reason, the same code | symbol is attached | subjected to the component which is common in 1st Embodiment, the description is abbreviate | omitted or simplified, and it demonstrates below centering on a different part from 1st Embodiment.

  The output member 103 is coaxially provided with an output shaft 105a that supports the end effector. Joint shafts 134 and 135 as a plurality of first projecting portions and joint shafts 136 and 137 as a plurality of second projecting portions are mounted and fixed at predetermined positions of the output shaft 105a of the output member 103 by press fitting or the like. ing. The joint shafts 134, 135, 136, and 137 may be formed integrally with the output shaft 105a.

  The joint shafts 134 and 135 as the two first projecting portions are provided so as to project in parallel from each other in the direction orthogonal to the output shaft 105a from the output shaft 105a. The joint shafts 134 and 135 have the same length and project in the same direction. The joint shafts 136 and 137 as two second projecting portions are provided so as to project from the output shaft 105a perpendicular to the output shaft 105a, in a direction different from the joint shafts 134 and 135, and in parallel with each other. ing. The joint shafts 136 and 137 have the same length and project in the same direction. Further, the joint shafts 134 and 135 and the joint shafts 136 and 137 have the same length, and the same position with respect to the axial direction of the output shaft 105a, and the phase around the axis of the output shaft 105a is shifted by 90 ° from each other. Is arranged.

  Further, in the case of the present embodiment, the first motor 107 as the first actuator, the second one on the one surface side (the upper side in FIG. 7B) of the virtual plane α parallel to the output shaft 105a and including the output shaft 105a. A second motor 108 as an actuator and a third motor 111 as a third actuator are arranged. On the other hand, the joint shafts 134, 135, 136, and 137 project to the other surface side (the lower side of FIG. 7B) of the virtual plane α.

The first arm 109 is composed of two first links 109a forming a parallel link mechanism, and one end is connected to the joint shafts 134 and 135 via a joint portion 109B (second joint portion) , and the other end is a first link. The link shaft 107b (link shaft portion) is connected via a joint portion 109C (first joint portion) . That is, the first arm 109 extends from one surface side of the virtual plane α toward the output shaft 105a, and is a joint as a protruding portion that protrudes to the other surface side of the output shaft 105 of the output member 103 from the virtual plane α. It is connected to shafts 134 and 135 . The two joint portions 109B connect the joint shafts 134 and 135 and the two first links 109a on a virtual axis (on the virtual axis β) parallel to the output shaft 105a.

The second arm 110 includes two second links 110a forming a parallel link mechanism, one end of which is connected to the joint shafts 136 and 137 via a joint portion 110B (second joint portion) , and the other end is a second link. The link shaft 108b (link shaft portion) is connected via a joint portion 110C (first joint portion) . That is, the second arm 110 extends from one surface side of the virtual plane α toward the output shaft 105a, and is a joint as a protruding portion that protrudes to the other surface side from the virtual plane α of the output shaft 105a of the output member 103. The shafts 136 and 137 are connected. That is, the output shaft 105a is disposed with a gap between the distal ends of the first arm 109 and the second arm 110, and is connected from both radial sides of the output shaft 105a at one radial side surface of the output shaft. In other words, the first arm 109 and the second arm 110 are extended from one radial side of the output shaft 105a toward one end surface on the other side (the lower side in FIG. 7B) . The two joint portions 110B connect the joint shafts 136 and 137 to the two second links 110a on a virtual axis (on the virtual axis γ) parallel to the output shaft 105a.

  Further, the two first links 109a constituting the first arm 109 and the two second links 110a constituting the second arm 110 are respectively bridged as in FIG. 3B. Members 201a, 202a, 201b, 202b are provided. That is, the bridge members 201a and 202a as the first bridge members are capable of relatively moving the two first links in the arrangement direction of the first arm 109 and preventing the first link 109a from rotating around the axis. As shown, the two first links 109a are spanned. In addition, the bridge members 201b and 202b as the second bridge members allow the two second links to move relative to each other in the arrangement direction of the second arm 110, and prevent rotation of the second link 110a around the axis. As described above, the two second links 110a are spanned.

  In the case of this embodiment, joint shafts 138 and 139 corresponding to a third axis orthogonal to the output shaft 105a are formed integrally with the output shaft 105a at the upper end portion of the output shaft 105a. The joint shafts 138 and 139 as separate members may be attached and fixed to the output shaft 105a by press fitting or the like. The joint shafts 138 and 139 are formed so as to protrude from the upper end portion of the output shaft 105a in the opposite directions and coaxially, and correspond to the third shaft of the first embodiment.

  The third arm 112 includes two third links 112a forming a parallel link mechanism. One end is connected to the joint shafts 138 and 139 via the joint portion 112B, and the other end is connected to the third link shaft 111b. 112C is connected. Similarly to the first arm 109 and the second arm 110, the two third links 112a constituting the third arm 112 are provided with bridge members 201c and 202c. That is, the bridge members 201c and 202c are arranged so that the two third links 112a can move relative to each other in the direction in which the third arm 112 is disposed, and the third link 112a is prevented from rotating around the axis. It is stretched over the third link 112a of the book.

  As shown in FIGS. 8 and 9, each of the joint portions described above is configured by a rod end bearing 210 having three degrees of freedom. The rod end bearing 210 has a structure in which a ring ball 211 having a hole for passing each joint shaft and a housing holder 212 are in contact with each other on a spherical surface.

  That is, the outer peripheral surface of the ring ball 211 is formed on a partial spherical surface, the housing holder 212 is rotatably fitted on the ring ball 211, and the inner peripheral surface that is in sliding contact with the outer peripheral surface of the ring ball 211 is a partial spherical surface. It is formed in a shape. The housing holder 212 is formed with a screw portion 212a and is screwed into a screw hole provided at the tip of each link of each arm, whereby the housing holder 212 is fixed to each link. As shown in FIG. 9, such a rod end bearing 210 has a structure in which the tilt angle θ is limited by the interference between the shaft 213 (corresponding to each joint shaft) inserted into the ring ball 211 and the housing holder 212. Exists.

Each joint part is demonstrated using FIG.6, FIG7 and FIG.10 . The joint portion 109B fixes the ring ball 211 to the ends of the joint shafts 134 and 135, and fixes the housing holder 212 to one end of the first link 109a. By this joint portion 109B, each first link 109a is rotated about a virtual axis β as an axis parallel to the output shaft 105a, and an axis orthogonal to the virtual axis β and the arrangement direction of the first arm 109 ( It is connected to the output shaft 105a with three degrees of freedom of rotation about the joint shafts 134 and 135) and rotation around the axis of the first link 109a.

The joint portion 109C has the ring balls 211 fitted and fixed to both ends of the first link shaft 107b, and the housing holder 212 is fixed to the other end of the first link 109a. By this joint portion 109C, each first link 109a rotates about the first link shaft 107b, and rotates about an axis orthogonal to the arrangement direction of the first link shaft 107b and the first arm 109. And the first link shaft 107b is connected to the first link shaft 107b with three degrees of freedom of rotation about the axis of the first link 109a.

  However, as described above, the bridge members 201a and 202a are stretched over the two first links 109a. Therefore, the first arm 109 including the two first links 109a has two degrees of freedom of rotation about the virtual axis β and rotation about the joint shafts 134 and 135 with respect to the output shaft 105a. Will be connected. The first arm 109 rotates about the first link shaft 107b with respect to the first link shaft 107b and is centered on an axis perpendicular to the arrangement direction of the first link shaft 107b and the first arm 109. Are connected with two degrees of freedom of rotation around the rotation.

The joint portion 110B has the ring balls 211 fitted and fixed to the tips of the joint shafts 136 and 137, respectively, and the housing holder 212 is fixed to one end of the second link 110a. By this joint portion 110B, each second link 110a is rotated about a virtual axis γ as an axis parallel to the output shaft 105a, and an axis (the axis orthogonal to the virtual axis γ and the arrangement direction of the second arm 110). It is connected to the output shaft 105a with three degrees of freedom of rotation around the joint shafts 136 and 137) and rotation around the axis of the second link 110a.

The joint portion 110C has the ring balls 211 fitted and fixed to both ends of the second link shaft 108b, and the housing holder 212 is fixed to the other end of the second link 110a. By this joint portion 110C, each second link 110a rotates about the second link shaft 108b, and rotates about an axis orthogonal to the direction in which the second link shaft 108b and the second arm 109 are disposed. , And connected to the second link shaft 108b with three degrees of freedom of rotation around the axis of the second link 110a.

  However, as described above, the bridge members 201b and 202b are stretched over the two second links 110a. For this reason, the second arm 110 including the two second links 110a has two degrees of freedom of rotation about the virtual axis γ and rotation about the joint shafts 136 and 137 with respect to the output shaft 105a. Will be connected. Further, the second arm 110 is centered on an axis perpendicular to the rotation of the second link shaft 108b and the arrangement direction of the second link shaft 108b and the second arm 110 with respect to the second link shaft 108b. Are connected with two degrees of freedom of rotation around the rotation.

  The joint portion 112B has the ring balls 211 fitted and fixed to the tips of the joint shafts 138 and 139, respectively, and the housing holder 212 is fixed to one end of the third link 112a. By this joint portion 112B, each third link 112a is rotated about an axis (joint shaft 138, 139) orthogonal to the output shaft 105a, and in the arrangement direction of the joint shaft 138, 139 and the third arm 110. It is connected to the output shaft 105a with three degrees of freedom of rotation about an orthogonal axis and rotation around the axis of the third link 112a.

  The joint portion 112C has the ring balls 211 fitted and fixed to both ends of the third link shaft 111b, respectively, and the housing holder 212 is fixed to the other end of the third link 112a. By this joint portion 112C, each third link 112a rotates about the third link shaft 111b, and rotates about an axis orthogonal to the arrangement direction of the third link shaft 111b and the third arm 112. And the third link 112a is connected to the third link shaft 111b with three degrees of freedom of rotation around the axis of the third link 112a.

  However, as described above, the bridge members 201c and 202c are stretched over the two third links 112a. For this reason, the third arm 112 composed of the two third links 112 a is rotated around the joint shafts 138 and 139 with respect to the output shaft 105 a and the joint shafts 138 and 139 and the third arm 110 are disposed. They are connected with two degrees of freedom of rotation about an axis orthogonal to the direction. The third arm 112 is centered on an axis orthogonal to the third link shaft 111b and the rotation direction of the third link shaft 111b and the arrangement direction of the third link shaft 111b and the third arm 112 with respect to the third link shaft 111b. Are connected with two degrees of freedom of rotation around the rotation.

  By the way, as shown in FIG. 9, the rod end bearing 210 constituting each joint part has a limitation of the inclination angle θ. Therefore, it is necessary to consider the arrangement of the joint portions (rod end bearings) so that the manipulator can move within the necessary movable range within the limit of the inclination angle θ.

  For this reason, in the two parallel links of the first arm 109, the joint portion (rod end bearing) 109B connected to the joint shafts 134 and 135 becomes the joint portion (rod end bearing) 109B connected to the first link shaft 107b. On the other hand, the phase angle of the housing holder is 90 degrees different. The same applies to the second arm 110.

  That is, the direction of the rotation center of the ring ball 211 of the joint portion 109B (the axial direction of the joint shafts 134 and 135) and the direction of the rotation center of the ring ball 211 of the joint portion 109C (the axial direction of the first link shaft 107b) The phase differs by 90 degrees with respect to the rotation direction around the first link 109a. The direction of the rotation center of the ring ball 211 of the joint part 110B (axial direction of the joint shafts 136 and 137) and the direction of the rotation center of the ring ball 211 of the joint part 110C (axial direction of the second link shaft 108b) The phase differs by 90 degrees with respect to the rotation direction around the second link 110a. Thereby, it is possible to eliminate the influence of the angle limit of the rod end bearing as much as possible, and to obtain a wider movement range in the vertical direction and the horizontal direction of the end effector.

  The direction of the rotation center of the ring ball 211 of the joint portion 112B (the axial direction of the joint shafts 138 and 139) and the direction of the rotation center of the ring ball 211 of the joint portion 112C (the axial direction of the third link shaft 111b) The third link 112a and the third link 112a are parallel to each other. However, these phases may be 90 degrees out of phase with respect to the rotation direction about the third link 112a.

  In the case of this embodiment configured as described above, as in the first embodiment described above, the two parallel link mechanisms formed by the first arm 109 and the second arm 110 and the parallel formed by the third arm 112. The end effector attached to the output member 103 is supported by the link mechanism so as to maintain a certain posture (both tilt and orientation).

  Moreover, since each joint part is a rod end bearing, the joint part can be reduced in size. As a result, the output member 103 can be configured more compactly, the workability of the robot can be improved, and a compact parallel link robot can be provided.

  Further, in the case of the present embodiment, the first motor 107, the second motor 108, and the third motor 111 are arranged on one side of the virtual plane α (the upper side in FIG. 7B), and the joint shafts 134, 135, 136 and 137 are projected to the other side of the virtual plane α (the lower side of FIG. 7B). The first arm 109 and the second arm 110 are arranged from one side of the virtual plane α toward the output shaft 105a, and are connected to the joint shafts 134, 135, 136, and 137 protruding to the other side of the virtual plane of the output shaft 105a. Connected. Therefore, the output member 103 can be supported by increasing the angle formed by the first arm 109 and the second arm 110, and the stability of the support of the output member 103 and the end effector can be improved. Specifically, even if the output member 103 moves to a position far from the first motor 107 and the second motor 108, the angle formed by the first arm 109 and the second arm 110 can be increased, and the output member 103 can be stably provided. And the end effector can be supported. That is, when the joint shafts 134 to 137 are arranged on the same side as the motors 107 and 108 with respect to the virtual plane α (the first arm 109 and the second arm 110 are connected on one side of the virtual plane α of the output shaft 105a. When the output member 103 moves to a position far from the first motor 107 and the second motor 108, the angle between the first arm 109 and the second arm 110 becomes narrow. When the angle formed by the first arm 109 and the second arm 110 becomes narrow, the output member 103 tends to become unstable. For this reason, in this embodiment, the joint shafts 134 to 137 are arranged on the opposite side of the motors 107 and 108 with respect to the virtual plane α so as to stably support the output member 103.

  The third motor 111 may be provided on the same side as the joint shafts 134 to 137 with respect to the virtual plane α. However, in order to reduce the overall size of the apparatus, the third motor 111 is the first motor 107. It is preferable to provide the same side as the second motor 108. Further, the joint portions 112B and 112C in the two parallel links of the third arm 112 may not be rod end bearings but may be joints with two degrees of freedom shown in FIG. Other configurations and operations are the same as those in the first embodiment.

<Third Embodiment>
A third embodiment of the present invention will be described with reference to FIGS. The difference from the second embodiment described above is that the first, second, and third actuators are respectively changed to linear motion linear actuators, and the first arm 109 and the second arm 110 on the actuator side. It is in the point which changed the composition of the joint part. For this reason, the same code | symbol is attached | subjected to the component which is common in 2nd Embodiment, the description is abbreviate | omitted or simplified, and it demonstrates below centering on a different part from 2nd Embodiment.

  The first linear actuator 141 and the second linear actuator 142, which are the first actuator and the second actuator, are examples of direct acting actuators that serve as driving sources for moving the output member 103 within a predetermined space. . In the first linear actuator 141 and the second linear actuator 142, rails (stator) 141a and 142a are arranged in a direction (vertical direction) substantially parallel to the output shaft 105a, respectively. As shown in FIG. 11, the rails 141a and 142a are respectively fixed to the middle portion or the lower end of the vertical plate 102 of the base member 100A. Then, as shown in FIG. 12, the first moving element 141b as a driving unit is provided on the rail 141a of the first linear actuator 141, and the second moving element 142b as a driving unit is provided on the rail 142a of the second linear actuator 142, respectively. It is arranged so as to be movable along the rail.

  Arm support members 143 and 144 are fixed to the first moving element 141b and the second moving element 142b, respectively. As shown in FIG. 13, joint shafts 145 and 146 and joint shafts 147 and 148 are mounted and fixed to the first arm support member 143 and the second arm support member 144, respectively, by press fitting or the like. That is, the joint shafts 145 and 146 are provided on the first moving element 141b as a drive unit via the first arm support member 143, and the joint shafts 147 and 148 are used as the drive unit via the second arm support member 144. The second moving element 142b is provided. The joint shaft 145 and the joint shaft 146, and the joint shaft 147 and the joint shaft 148 are provided in parallel, respectively. Further, the joint shafts 145 and 146 have the same length and are formed in parallel with the joint shafts 134 and 135, and the joint shafts 147 and 148 have the same length and are formed in parallel with the joint shafts 136 and 137. Yes.

  As shown in FIG. 14, the output member 103 is provided with an output shaft 105a that supports the end effector 104 on the same axis. Similarly to the second embodiment described above, joint shafts 134 and 135 serving as a plurality of first projecting portions and joint shafts serving as a plurality of second projecting portions are provided at predetermined positions of the output shaft 105a of the output member 103, respectively. 136 and 137 are mounted and fixed by press-fitting or the like.

The first arm 109 includes two first links 109 a forming a parallel link mechanism, one end is connected to the joint shafts 134 and 135 via the joint portion 109 </ b> B, and the other end is a joint of the first arm support member 143. The shafts 145 and 146 are connected via a joint portion 109C . The two joint portions 109B connect the joint shafts 134 and 135 and the two first links 109a on a virtual axis parallel to the output shaft 105a, respectively . The two joint portions 109C connect the joint shafts 145 and 146 and the two first links 109a on a virtual axis parallel to the output shaft 105a, respectively. In the present embodiment, the virtual axis on which the two joint portions 109C are arranged corresponds to the first link axis.

The second arm 110 includes two second links 110a forming a parallel link mechanism, one end of which is connected to the joint shafts 136 and 137 via the joint portion 110B, and the other end is a joint of the second arm support member 144. The shafts 147 and 148 are connected via a joint portion 110C . The two joint portions 110B connect the joint shafts 136 and 137 to the two second links 110a on a virtual axis parallel to the output shaft 105a . The two joint portions 110C connect the joint shafts 147 and 148 and the two second links 110a, respectively, on a virtual axis parallel to the output shaft 105a. In the present embodiment, the virtual axis on which the two joint portions 110C are arranged corresponds to the second link axis.

  The third linear actuator 149, which is the third actuator, is an example of a direct acting actuator that serves as a drive source for moving the output member 103 in a direction substantially parallel to the output shaft 105a in a predetermined space. Similarly to the first linear actuator 141 and the second linear actuator 142, the third linear actuator 149 also has a rail (stator) 149a arranged in a direction (vertical direction) substantially parallel to the output shaft 105a. The rail 149a is fixed between the rail 141a and the rail 142a in the horizontal direction near the vertical middle portion or upper end of the vertical plate 102. A third moving element 149b as a drive unit is arranged on the rail 149a of the third linear actuator 149 so as to be movable along the rail.

  A third arm support member 150 is fixed to the third moving element 149b. As shown in FIG. 13, the third arm support member 150 has a joint shaft 151 fixed by a knock pin or the like. That is, the joint shaft 151 is provided on the third moving element 149 b as a driving unit via the third arm support member 150. The joint shafts 138 and 139 are formed so as to protrude from the upper end portion of the output shaft 105a in the opposite directions and coaxially, and correspond to the third shaft of the first embodiment. The joint shaft 151 is disposed in parallel with the joint shafts 138 and 139.

  As shown in FIG. 14, joint shafts 138 and 139 disposed in the direction orthogonal to the output shaft 105a are formed integrally with the output shaft 105a at the upper end portion of the output shaft 105a. In the present embodiment, the joint shafts 138 and 139 are arranged at positions deviating from the same plane as the output shaft 105a. Specifically, the joint shafts 138 and 139 and the output shaft 105a are configured to be three-dimensionally orthogonal with two planes offset at the front and rear (left and right direction in FIG. 11B) (at the position of twist). .

  The third arm 112 includes two third links 112 a forming a parallel link mechanism, one end of which is connected to the joint shafts 138 and 139 via the joint portion 112 </ b> B, and the other end is a joint of the third arm support member 150. The shaft 151 is connected to the shaft 151 via the joint portion 112C. The two joint portions 112B connect the joint shafts 138 and 139 and the two third links 112a on a third axis orthogonal to the output shaft 105a. The two joint portions 112C connect both ends of the joint shaft 151 parallel to the third axis and the two third links 112a, respectively. In the present embodiment, the joint shaft 151 on which the two joint portions 112C are arranged corresponds to the third link shaft.

  In the case of this embodiment as well, although not shown in the figure, the two first links 109a constituting the first arm 109 and the two second links 110a constituting the second arm 110 are divided into a third Each of the two third links 112a constituting the arm 112 is provided with a bridge member as in the above-described FIG.

  Also in the present embodiment, each joint portion described above is configured by a rod end bearing 210 having three degrees of freedom, as in the second embodiment. However, the phase of the housing holders of the joint portion 109C and the joint portion 110C, in which the other ends of the two first links 109a and the two second links 110a are connected to the joint shafts 145 and 146 and the joint shafts 147 and 148, respectively. The angle is different from that of the second embodiment.

  That is, the direction of the rotation center of the ring ball of the joint portion 109C is the direction of the rotation center of the ring ball of the joint portion 109B that connects one end of the two first links 109a to the joint shafts 134 and 135. Are parallel to each other in a direction orthogonal to Similarly, the direction of the rotation center of the ring ball 211 of the joint portion 110C is the direction of the rotation center of the ring ball of the joint portion 110B that connects one end of the two second links 110a to the joint shafts 136 and 137. They are parallel to each other in the direction orthogonal to the axis 105a.

  As described above, the end effector attached to the output member 103 is fixed in a certain posture (by the two parallel link mechanisms formed by the first arm 109 and the second arm 110 and the parallel link mechanism formed by the third arm 112). It is supported to maintain both (tilt) and orientation. The first, second, and third linear actuators 141, 142, and 149 maintain this posture regardless of the vertical position of the first, second, and third arm support members 143, 144, and 150, respectively. Is done.

  In FIG. 12, the first, second, and third linear actuators 141, 142, and 149 are driven to move the first, second, and third arm support members 143, 144, and 150, so that the output member 103 is moved. It shows a state in which it is moved in a predetermined direction within the same plane. The position of the output member 103 in the two-dimensional plane can be geometrically calculated from the movement amounts of the first, second, and third arm support members in consideration of the length and inclination of each arm. Further, by calculation of inverse kinematics, the amount of movement of the first, second, and third arm support members 143, 144, and 150 and the amount of drive of the first, second, and third actuators from the plane position center coordinates of the output member 103 Can be calculated.

  Furthermore, the vertical movement of the output member 103 can be easily performed by moving the first, second, and third arm support members 143, 144, and 150 by the same amount. As described above, the movement position of the output member 103 in the three-dimensional space can be controlled.

  In the present embodiment configured as described above, the first, second, and third linear actuators include a ball screw that includes a moving guide member of a moving element, and a rotary motor that rotates the ball screw. This is a linear motion mechanism that converts the rotational motion of the motor into linear motion. However, the linear motion mechanism is not limited to this, and a linear motion mechanism using a belt or a wire or an actuator such as a linear motor may be used.

  In this embodiment, each joint portion is a rod end bearing having three degrees of freedom. However, these joint portions have no functional problem as long as they have at least two degrees of freedom, and are shown in FIG. Such a joint having a structure having two degrees of freedom may be used.

  In the present embodiment, the joint shafts 138 and 139 that are orthogonal to the output shaft 105a are not three-dimensionally orthogonal to each other but two planes that are offset in the front-rear direction. It is possible to prevent interference with the arm 112 as much as possible. Other structures and operations are the same as those in the second embodiment.

<Other embodiments>
Note that the above-described embodiments can be implemented in combination as appropriate. For example, in the first embodiment, each motor may be a linear actuator as in the third embodiment.

100 Parallel link robot 103 Output member (manipulator)
104 End effector 105, 105a Output shaft 106 Third shaft 107 First motor (first actuator)
107a 1st rotation arm (drive part)
107b First link shaft (link shaft)
108 Second motor (second actuator)
108a Second rotating arm (drive unit)
108b Second link shaft (link shaft)
109 First arm 109a First link 109b, 109c Joint portion 109B Joint portion ( second joint portion)
109C Joint part ( first joint part)
110 2nd arm 110a 2nd link 110b, 110c Joint part 110B Joint part (2nd joint part)
110C Joint part ( first joint part)
111 Third motor (third actuator)
111a 3rd rotation arm (drive part)
111b Third link shaft 112 Third arm 112a Third link 112b, 112c, 112B, 112C Joint portion 131 Connecting member 132 First shaft 133 Second shaft 134, 135 Joint shaft (first projecting portion)
136, 137 Joint shaft (second protrusion)
138, 139 Joint axis (third axis)
141 First linear actuator (first actuator)
141b First mover (drive unit)
142 Second linear actuator (second actuator)
142b Second mover (drive unit)
149 Third linear actuator (third actuator)
149b Second mover (drive unit)
151 Joint shaft (third link shaft)
201a, 202a Bridge member (first bridge member)
201b, 202b Bridge member (second bridge member)
201c, 202c Bridge member 210 Rod end bearing 211 Ring ball 212 Housing holder

Claims (5)

An output member having an output shaft;
A first actuator and a second actuator for moving the output member in a direction orthogonal to the axial direction of the output shaft;
A third actuator for moving the output member in the axial direction of the output shaft;
A first arm connecting the output member and the first actuator by a parallel link mechanism;
A second arm for connecting the output member and the second actuator by a parallel link mechanism;
A third arm for connecting the output member and the third actuator by a parallel link mechanism,
Each of the first arm and the second arm has a link shaft portion that is an axis parallel to the axial direction of the output shaft, and the link shaft is a first joint portion provided at both ends of the link shaft portion. While being connected to be rotatable about the axis of the part, it is connected to the output member so as to be directly rotatable by a second joint part having a rotation axis in a direction orthogonal to the rotation axis direction of the first joint part. Was
A parallel link robot characterized by that. An output member having an output shaft whose vertical direction is the axial direction, and holding means for holding the posture of the output member by a plurality of arms,
The holding means includes a first arm and a second arm that hold the output shaft of the output member from both sides thereof, and a third arm that is formed of a parallel link mechanism that holds the output member from above in the vertical direction. Have
The first arm and the second arm extending from one side of a virtual plane including the output shaft and parallel to the output shaft toward the output shaft are different from the virtual plane of the output member. Connected to the direction side,
A parallel link structure characterized by that. An output member in which the vertical upper end of the output shaft with the axial direction as the vertical direction is coupled to the horizontal central portion of the third axis with the axial direction as the horizontal direction, and the posture of the output member is held by a plurality of arms Holding means,
The holding means includes a first arm and a second arm that hold the output shaft of the output member from both sides thereof, and a third arm that holds the output member from above in the vertical direction,
The third arm is formed of a parallel link mechanism, and a pair of links forming the parallel link mechanism at a symmetrical position in a horizontal direction are connected to the output member from a portion where the output shaft of the third shaft is joined. Is held from above in the vertical direction,
The first arm and the second arm extending from one side of a virtual plane including the output shaft and parallel to the output shaft toward the output shaft are different from the virtual plane of the output member. Connected to the direction side,
  A parallel link structure characterized by that. The output shaft is disposed between tip portions of the first arm and the second arm, and is connected from both radial sides of the output shaft at one radial side surface portion of the output shaft. The parallel link structure according to claim 2 or 3. A parallel link robot having the parallel link structure according to any one of claims 2 to 4.

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