JP5883638B2 - Delta parallel robot - Google Patents

Description

  The present invention relates to a delta parallel robot including a base, a bracket for attaching a tool, and three sets of arm mechanisms for connecting the base to the bracket.

  The delta-type parallel robot includes a base, a bracket for attaching a tool, and three sets of arm mechanisms that connect the bracket to the base, and each arm mechanism constitutes a parallel link. When the arm mechanism operates, the bracket and the tool attached thereto move without changing the posture with respect to the base. Taking advantage of this characteristic, the delta type parallel robot is suitably used for various operations such as picking operations in food factories.

  Patent Document 1 discloses a general conventional example of an arm mechanism. The conventional arm mechanism has one upper arm and two lower arms. The upper arm is rotatably connected to the base at the proximal end and extends from the base. Fixed to the upper arm are upper side links extending from the tip portion to opposite sides. The two lower arms extend parallel to each other between the distal end portion of the upper arm and the bracket, and are disposed so as to sandwich the distal end portion of the upper arm at the proximal end portion and sandwich the bracket at the distal end portion. Also fixed to the bracket are lower links extending in opposite directions. Each lower arm is rotatably connected to the end of the upper link via a ball joint at the base end, and is rotatably connected to the end of the lower link via a ball joint at the distal end. The upper side link, the lower side link, and the two lower arms are configured to maintain a parallelogram even when the upper arm rotates.

Special Table 2002-532269

  By the way, when a delta type parallel robot is put into practical use, it is necessary to periodically perform maintenance work and disassemble and reassemble the arm mechanism. For example, in the conventional arm mechanism, in order to cope with wear of the ball joint, it is necessary to replace the ball joint at an appropriate time, and it is necessary to remove the lower arm from the upper arm and the bracket.

  However, in the conventional arm mechanism, the upper arm is connected to the middle part of the upper link, the bracket is connected to the middle part of the lower link, and the parallelogram formed by the upper link, the lower link and the two lower arms is It is held on both sides of the upper arm and the bracket (hereinafter, for convenience of explanation, this structure mode is referred to as “both-end support structure”).

  According to this both-end support structure, when it is desired to remove only one set of arm mechanisms, the two lower arms must be removed, and the disassembling work becomes complicated. Moreover, the parallelogram always collapses when disassembling. For this reason, after that, it is necessary to reattach the two lower arms so as to form a parallelogram, and the reassembly work becomes complicated. In order to maintain the engagement of the ball joint, a spring may be bridged between the two lower arms. In this case, it becomes necessary to remove and reattach the spring, and the disassembling operation and the reassembling operation become more complicated.

  Accordingly, an object of the present invention is to make it possible to easily disassemble and reassemble the arm mechanism, and thereby to easily perform maintenance work of the delta type parallel robot.

The present invention has been made to achieve the above object. A delta-type parallel robot according to the present invention includes a base, a bracket for attaching a tool, and three sets of arm mechanisms that connect the base to the bracket, and each of the arm mechanisms is at a base end portion. An upper arm rotatably connected to the base; and a parallel link portion that connects a tip portion of the upper arm to the bracket. The parallel link portion includes an upper side link, a lower side link, and a parallelogram. A pair of lower arms, each of the pair of lower arms is rotatably connected to the upper side link at a base end portion and is rotatably connected to the lower side link at a distal end portion, and one end of the upper side link is The upper side link is rotatably connected to the distal end of the upper arm so that the rotational axis of the upper side link is orthogonal to the rotational axis of the base end of the pair of lower arms, End corresponding to one end of the link is rotatably connected to the bracket so that the rotation shaft of the lower side link is orthogonal to the axis of rotation of the tip portions of the pair of the lower arm, respectively corresponding to the three sets of arm mechanism The rotation axes of the base end portions of the three upper arms are assumed to intersect with each other in a regular triangle on a predetermined reference plane, and the rotation axis of each upper side link corresponds to the upper side link. The rotation axis of each upper side link is parallel to the rotation axis of the upper side link corresponding to the lower side link, and one end of the upper side link and the lower side link One end is detachably connected to the upper arm and the bracket, respectively.

  According to the said structure, the parallel link part which has the upper side link which comprises a parallelogram, a lower side link, and a pair of lower arm is cantilevered by an upper arm and a bracket. For this reason, if one end of the upper link and one end of the lower link are removed from the upper arm and the bracket, the entire parallel link portion can be removed from the robot without breaking the parallelogram. Then, the robot can be replaced with a new parallel link in a short time at the installation site of the robot, and the maintenance work of the arm mechanism can be performed efficiently. In addition, after disassembling the parallel link portion, maintenance work can be performed at a location away from the installation site of the robot, and the parallel link portion can be reassembled so that a parallelogram is formed. Also, reassembly of the robot can be completed simply by connecting one end of the upper link and one end of the lower link of the assembled parallel link portion to the upper arm and the bracket. As described above, since the parallel link portion is cantilevered, the arm mechanism can be easily disassembled and reassembled compared to the double-supported structure, and the maintenance work of the robot is simplified.

  Each of the pair of lower arms may be connected to the upper side link via a cylindrical pair, and may be connected to the lower side link via a cylindrical pair.

  Since the degree of freedom of rotation required for the parallel link part is shared by the connecting part to the upper arm of the upper link and the connecting part to the bracket of the lower link, the connecting part to the upper link of the base end of the lower arm In addition, the degree of rotational freedom required for the connecting portion to the lower side link at the tip of the lower arm is lowered. Then, it is not necessary to apply a spherical pair such as a ball joint to these connecting portions, and it is also possible to apply a cylindrical pair. Then, it is possible to simply provide a structure capable of suppressing the lower arm from falling off the upper side link or the lower side link without providing a coupling member such as a spring in the connecting portion.

Of the pair of lower arms, the lower arm disposed distally from the upper arm may have lower strength than the lower arm disposed proximal to the upper arm.

  According to the above configuration, the lower arm disposed distally from the upper arm has a smaller load such as torsion and bending acting during the operation of the arm mechanism than the lower arm disposed proximally. For this reason, it is possible to select a shape that is easy to machine and inexpensive materials for the lower arm placed distally, even if the strength is not so high, and it is possible to reduce the manufacturing cost of the delta type parallel robot become.

  Of the pair of lower arms, the lower arm disposed proximal to the upper arm has a notch formed on a side surface of the base end portion near the upper arm so as to move away from the upper arm. You may have a recessed part.

  According to the said structure, the possibility that the lower arm arrange | positioned proximally to an arm may interfere with an upper arm can be reduced. Then, the movable range of the upper arm and the pair of lower arms can be expanded while bringing the pair of lower arms as close as possible to the upper arm and the bracket to make the parallel link portion compact, and consequently the movable range of the bracket and the tool is made as wide as possible. be able to.

  According to the present invention, the arm mechanism can be easily disassembled and reassembled, whereby the maintenance work of the delta parallel robot can be easily performed.

  The above and other objects, features and advantages of the present invention will become apparent from the following detailed description of the preferred embodiments with reference to the accompanying drawings.

It is a top view which shows the delta type | mold parallel robot which concerns on embodiment of this invention. It is a bottom view which shows the delta type | mold parallel robot shown in FIG. It is a conceptual diagram which shows the parallel link part of the delta type | mold parallel robot shown in FIG. FIG. 4A is a front view showing the delta type parallel robot shown in FIG. FIG. 4B is a front view showing the delta parallel robot with the parallel link portion removed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that, throughout all the drawings, the same or corresponding elements are denoted by the same reference numerals, and detailed description thereof is omitted.

  FIG. 1 is a plan view showing a delta parallel robot 1 according to an embodiment of the present invention. FIG. 2 is a bottom view showing the delta parallel robot 1 shown in FIG. A delta type parallel robot 1 (hereinafter simply referred to as “robot 1”) shown in FIG. 1 and FIG. 2 is installed at a work site in a production factory for food, medicine, cosmetics, small electronic parts, etc. It is suitably used as a robot that performs various operations such as operations and component assembly operations.

  As shown in FIGS. 1 and 2, the robot 1 includes a base 2, a bracket 3 for attaching a tool (not shown) for various operations, and three sets of arm mechanisms 4 that connect the base 2 to the bracket 3. And. In general, in a state where the robot 1 is installed at the work site, the base 2 is placed on the top and the bracket 3 is placed on the bottom. The tool is detachably attached to the lower surface side of the bracket 3. A tool actuator 5 for rotationally driving the tool is provided on the upper surface side of the bracket 3 as necessary. Of course, it goes without saying that the robot 1 can be installed at a work site in an arbitrary posture.

  Each arm mechanism 4 includes an upper arm 6 that is rotatably connected to the base 2 at the base end portion 7, and a parallel link portion 10 that connects the distal end portion 8 of the upper arm 6 to the bracket 3. The parallel link unit 10 includes an upper side link 11, a lower side link 12, and a pair of lower arms 13 and 14.

  The base end portion 7 of the upper arm 6 is connected to the base 2 so as to be rotatable around the rotation axis A1. Three arm actuators 9 are attached to the base 2, and the three arm actuators 9 correspond to the three upper arms 6, respectively. The upper side link 11 is connected to the distal end portion 8 of the upper arm 6. The lower link 12 is connected to the bracket 3 and extends in parallel with the upper link 11. The pair of lower arms 13 and 14 is rotatably connected to the upper side link 11 at the base end portions 15 and 17 and is rotatably connected to the lower side link 12 at the front end portions 16 and 18. The pair of lower arms 13 and 14 extend in parallel to each other. Thus, the upper side link 11, the lower side link 12, and the pair of lower arms 13 and 14 are connected so as to form a parallelogram, and constitute a parallel link mechanism.

  The robot 1 assumes (sets) a total of three rotation axes A1 and is provided with a total of three lower links 12. The three rotation axes A1 are assumed (set) to be 120-degree rotationally symmetric on a certain reference plane. Since the upper arm 6 is connected to the base 2, the position and posture of the reference plane are constant if the position and posture of the base 2 are determined. The three lower side links 12 are arranged so as to be 120-degree rotationally symmetric on a plane parallel to the reference plane. In general, in a state where the robot 1 is installed at a work site, the base 2 is arranged on the upper side, the bracket 3 is arranged on the lower side, and the reference plane is arranged horizontally as described above.

  The bracket 3 is connected to three lower side links 12. When any one of the arm actuators 9 is actuated, the corresponding upper arm 6 rotates about the rotation axis A1. At this time, all the parallel link parts 10 operate | move so that the upper side link 11, the lower side link 12, and a pair of lower arms 13 and 14 may maintain the state which comprises a parallelogram. For this reason, the plane in which the three lower side links 12 are arranged is maintained in parallel with the reference plane, and as a result, the bracket 3 moves within the work site without changing the posture with respect to the base 2.

  FIG. 3 is a conceptual diagram showing the parallel link unit 10 shown in FIG. In order to maintain the posture of the bracket 3 without breaking the parallelogram of the parallel link portion 10 regardless of the operation of the upper arm 6, the proximal end portion 15 of the first lower arm 13 and the proximal end of the second lower arm 14 are maintained. The portion 17 has a degree of freedom of rotation about two axes with respect to the upper arm 6, and the distal end portion 16 of the first lower arm 13 and the distal end portion 18 of the second lower arm 14 are 2 with respect to the bracket 3. It is required to have a degree of freedom of rotation around the axis.

  In response to this requirement, in a conventional general robot, a pair of lower arms is rotatably connected to the upper link via a spherical pair at the base end, and can be rotated via a spherical pair to the lower link at the distal end. Connected to Speaking of the spherical pair between the upper link and the base ends of the pair of lower arms, a spherical pair element (ball element or socket element) is attached to the end of the upper link to simplify the structure. Is the mainstream. Then, the upper side link must be connected to the upper arm 6 at the intermediate portion. The same applies to the spherical pair between the lower link and the tip of the pair of lower arms. In this manner, a “both-end supported structure” in which the parallelogram of the parallel link portion is held on both sides of the upper arm and the bracket is applied to a conventional general robot.

  On the other hand, in the present embodiment, the parallel link portion 10 protrudes to one side when viewed from the upper arm 6 and the bracket 3. The parallelogram of the parallel link portion 10 is held on one side as viewed from the upper arm 6 and the bracket 3 (hereinafter, for convenience of explanation, this structure is referred to as “cantilever structure”).

  In the present embodiment to which the cantilever structure is applied, the upper side link 11 is connected to the distal end portion of the upper arm 6 at one end portion 19 instead of the intermediate portion. The lower link 12 is also connected to the bracket 3 at one end 20 corresponding to one end of the upper link 11. Thereby, the upper side link 11 protrudes in a cantilever shape from the distal end portion 8 of the upper arm 6, and the lower side link 12 protrudes in a cantilever shape from the bracket 3.

  The pair of lower arms 13 and 14 connect the upper side link 11 to the lower side link 12 and are arranged in the extending direction of the upper side link 11 or the extending direction of the lower side link 12. In the following description, the lower arm disposed on the side closer to the upper arm 6 in the extending direction of the upper side link 11 is referred to as “first lower arm 13”, and the lower arm disposed on the side far from the upper arm 6 is referred to. This is referred to as “second lower arm 14”.

  One end 19 of the upper link 11 is connected to the tip 8 of the upper arm 6 so as to be capable of rotating about the rotation axis A2. Then, the degree of freedom of rotation required for the base end portion 15 of the first lower arm 13 is shared by the rotation of the upper side link 11. Therefore, the base end portion 15 of the first lower arm 13 may be connected to the upper side link 11 so as to be rotatable around one axis. The same applies to the base end portion 17 of the second lower arm 14. Therefore, in the present embodiment, the base end portion 15 of the first lower arm 13 is connected to the upper side link 11 via the cylindrical pair 21 so as to be rotatable around the rotation axis A3, and the base end portion 17 of the second lower arm 13 is also configured. The upper link 11 is coupled to the upper link 11 via a cylindrical pair 22 so as to be rotatable around a rotation axis A4.

  The same applies to the lower link 12, the distal end portion 16 of the first lower arm 13, and the distal end portion 18 of the second lower arm 14. One end 20 of the lower link 12 is connected to the bracket 3 so as to be capable of rotating about the rotation axis A5. The distal end portion 16 of the first lower arm 13 is connected to the lower side link 12 via a cylindrical pair 23 so as to be rotatable around the rotation axis A6, and the distal end portion 18 of the second lower arm 14 is connected to the lower side link 12 with a cylindrical pair 24. Is connected to be rotatable around a rotation axis A7.

  The rotation axes A3 and A4 are parallel to each other and orthogonal to the rotation axis A2. The rotation axes A6 and A7 are parallel to each other and orthogonal to the rotation axis A6. The rotation axes A2 and A6 are parallel to each other, and the rotation axes A3, A4, A6 and A7 are parallel to each other. The rotation axes A2 and A6 are parallel to the rotation axis A1 (see FIGS. 1 and 2). By arranging the axes in this way, when the upper arm 6 is moved, the bracket 3 is moved while maintaining the posture of the bracket 3 without breaking the parallelogram of the parallel link portion 10 regardless of the operation. Can do.

  The cylinder pair includes a cylindrical element having a circular cross section and a columnar element that is rotatably fitted in the cylindrical element. Unlike ball and socket elements, both cylindrical and cylindrical elements provide the required rotational motion for the links 11 and 12 and the lower arms 13 and 14, while at the middle of the links 11 and 12. Easy to install. Therefore, even if the cantilever structure is adopted, the two parts that connect the upper link 11 to the lower arms 13 and 14 and the two parts that connect the lower link 12 to the lower arms 13 and 14 are increased in size. And not complicated. In addition, regarding the cylindrical pair 21 between the upper side link 11 and the first lower arm 13, the cylindrical element may be provided on either the upper side link 11 or the first lower arm 13. The same applies to the other cylindrical pairs 22-24. In this embodiment, as an example, cylindrical elements are provided on the upper side link 11 and the lower side link 12, and columnar elements are provided on the pair of lower arms 13 and 14.

  In a conventional general robot, a spring spanned between a pair of lower arms is provided to prevent the ball element from falling off the socket element. This spring urges the pair of lower arms toward each other, thereby pressing the ball element against the socket element. Without this spring, the pair of lower arms can undesirably disengage from the upper arms or brackets and scatter in the work site.

  On the other hand, in the cylindrical pair 21-24 employ | adopted by this embodiment, it is possible to incorporate the structure for preventing a column element from dropping from a cylindrical element in each cylindrical pair 21-24. For example, it is possible to prevent the columnar element from falling off the cylindrical element only by providing the columnar element with a configuration such as a collar or a nut that forms a stepped cylinder together with the columnar element. That is, according to the robot 1 according to the present embodiment, it is possible to prevent the pair of lower arms 13 and 14 from being detached from the upper arm 11 or the bracket 2 while omitting the spring for preventing the dropout that has been provided. .

  Since the second lower arm 14 is disposed distally from the upper arm 6 and the bracket 3, the second lower arm 14 is compared with the first lower arm 13 and is twisted or bent that acts during operation of the arm mechanism 4. Etc. The load is small. For this reason, the strength of the second lower arm 14 may be lower than that of the first lower arm 13. Therefore, the necessity for emphasizing strength in designing the second lower arm 14 is relatively low, and the shape and material options of the second lower arm 14 are increased. For example, a material having a small specific gravity, a shape that can be easily processed, and an inexpensive material can be positively selected, thereby reducing the weight of the robot 1, simplifying the manufacturing process, and reducing the manufacturing cost.

  As an example, a steel circular tube is applied to the first lower arm 13 in view of securing rigidity, while an aluminum alloy flat plate is applied to the second lower arm 14 in view of weight reduction, processability and cost. You may apply.

  Returning to FIGS. 1 and 2, when a circular tube is applied to the first lower arm 13, a fixing bracket 31 may be provided at the base end portion of the first lower arm 13. The fixing bracket 31 may be formed in a clevis shape. That is, one end of the fixing bracket 31 is formed in a cylindrical shape that is fitted into a circular tube, while the other end of the fixing bracket 31 may have a pair of flat plates that are divided into two. Thus, when the fixing bracket 31 is clevis-shaped, the upper side link 11 may be sandwiched between a pair of flat plates of the fixing bracket 31. If it does in this way, the connection strength with respect to the upper link 11 of the 1st lower arm 13 will improve, and the 1st lower arm 13 will endure load well. Further, if the rigidity of the fixing bracket 31 is high, it is not necessary to increase the rigidity of the circular pipe. Therefore, the degree of freedom in selecting the material, outer diameter, and plate thickness of the circular tube is improved. If the same fixing bracket 32 is also provided at the tip of the first lower arm 13, such an action and effect are further improved.

  The first lower arm 13 is a notch formed in a direction away from the upper arm 6 (in other words, a direction approaching the second lower arm 14) on a side portion facing the upper arm 6 at the base end portion. A recess 33 is provided. The first lower arm 13 also has a notch recess 34 that is cut away in a direction away from the bracket 3 on the side that faces the bracket 3 at the tip. When the cutout recesses 33 and 34 are provided, the first lower arm 13 is disposed closer to the upper arm 6 and the bracket 3 than the second lower arm 14, even though the first lower arm 13 is disposed closer to the upper arm 6 and the bracket 3. The possibility of interference with the upper arm 6 or the bracket 3 can be reduced. Then, the first lower arm 13 can be brought as close to the upper arm 6 and the bracket 3 as possible, and the second lower arm 14 can be brought closer to the upper arm 6 and the bracket 3 as much as possible. Thereby, in this embodiment which employ | adopted the cantilever structure, expanding the movable range of the upper arm 6 and the parallel link part 10 as much as possible, suppressing that the parallel link part 10 protrudes largely from the upper arm 6 and the bracket 3. FIG. As a result, the movable range of the bracket 3 and the tool can be expanded as much as possible.

  In this embodiment, a notch recess 33 at the base end is provided in the fixing bracket 31 at the base end, and a notch recess 34 at the tip is provided in the fixing bracket 32 at the tip. . Therefore, the cutout recesses 33 and 34 can be provided in the first lower arm 13 without special processing of the circular tube. As described above, when the fixing brackets 31 and 32 having the cutout recesses 33 and 34 are attached to the ends of the circular tube, both the improvement of the strength of the first lower arm 13 as a whole and the improvement of the design freedom of the circular tube are achieved. Is achieved, and at the same time, the compactness of the parallel link portion 10 and the expansion of the movable range of the tool are also achieved, which is beneficial.

  4A is a front view showing the delta-type parallel robot 1 shown in FIG. 1, and FIG. 4B is a front view showing the delta-type parallel robot 1 with the parallel link portion 10 removed. 4A and 4B, one end 19 of the upper link 11 and one end 20 of the lower link 12 are detachably connected to the upper arm 6 and the bracket 3, respectively. .

  As shown in FIG. 4 (b), the upper side link 11, the lower side link 12, and the pair of lower arms 13, 14 are simply removed from the upper arm 6 and the lower side link 12 is removed from the bracket 3. The entire parallel link portion 10 is removed from the robot 1 without breaking the parallelogram formed by the above. Then, if a spare for the parallel link unit 10 is prepared, it can be replaced with a new parallel link unit 10 in a short time at the installation site of the robot 1. Even if there is no spare, after performing the maintenance work at a place away from the installation site of the robot 1 after disassembling the ballerel link portion 10, the upper link 11, the lower link 12, and the pair of lower arms 13, 14 are parallel four sides. The parallel link portion 10 can be reassembled to form a shape. Thus, the maintenance work of the arm mechanism 4 can be performed efficiently. Then, the reassembly operation of the robot 1 is completed by simply connecting the one end 19 of the upper link 11 and the one end 20 of the lower link 12 to the bracket 3. As described above, since the robot 1 adopts the cantilever structure, the arm mechanism 4 can be easily disassembled and reassembled compared to the case where the both-end support structure is adopted, and the maintenance work of the robot 1 can be performed easily. Can do. It is not particularly limited how the one end 19 of the upper side link 11 is detachably and rotatably connected to the upper arm 6. The same applies to the one end 20 of the lower link 12 and the bracket 3.

  From the foregoing description, many modifications and other embodiments of the present invention are obvious to one skilled in the art. Accordingly, the foregoing description should be construed as illustrative only and is provided for the purpose of teaching those skilled in the art the best mode of carrying out the invention. The details of the structure and / or function may be substantially changed without departing from the spirit of the invention.

  The present invention makes it possible to easily disassemble and reassemble the arm mechanism, thereby providing an operational effect that maintenance work of the delta parallel robot can be easily performed, and a delta parallel robot having a parallel link portion. It is beneficial to apply to.

DESCRIPTION OF SYMBOLS 1 Delta type parallel robot 2 Base 3 Bracket 4 Arm mechanism 6 Upper arm 10 Parallel link part 11 Upper side link 12 Lower side link 13 First lower arm 14 Second lower arm 21-24 Cylindrical pair 33, 34 Notch recessed part A1 Upper arm Axis of rotation A2 for the upper link A3 for the upper arm of the upper link Rotation axis A4 for the upper link of the first lower arm Rotation axis A5 of the upper link of the second lower arm A6 Axis of rotation of the lower link bracket A6 Lower side of the first lower arm Rotation axis for the link A7 Rotation axis for the lower link of the second lower arm

Claims (4)

A base, a bracket for attaching a tool, and three sets of arm mechanisms for connecting the base to the bracket;
Each of the arm mechanisms has an upper arm that is rotatably connected to the base at a base end portion, and a parallel link portion that connects a distal end portion of the upper arm to the bracket. An upper link, a lower link and a pair of lower arms forming a parallelogram;
Each pair of the lower arms is rotatably connected to the upper side link at a base end portion and is rotatably connected to the lower side link at a distal end portion, and one end of the upper side link has a rotation axis of the upper side link. One end corresponding to one end of the upper side link of the lower side link is rotatably connected to the distal end portion of the upper arm so as to be orthogonal to the rotation axis of the base end portion of the pair of lower arms. The shaft is rotatably connected to the bracket so as to be orthogonal to the rotation axis of the tip portion of the pair of lower arms,
The rotation axes of the base end portions of the three upper arms respectively corresponding to the three sets of arm mechanisms are assumed to intersect with each other in a regular triangle on a predetermined reference plane,
The rotation axis of each upper side link is parallel to the rotation axis of the base end portion of the upper arm corresponding to the upper side link,
The rotation axis of each lower side link is parallel to the rotation axis of the upper side link corresponding to the lower side link,
A delta type parallel robot, wherein one end of the upper side link and one end of the lower side link are detachably connected to the upper arm and the bracket, respectively.   2. The delta parallel robot according to claim 1, wherein each pair of the lower arms is connected to the upper side link via a cylindrical pair, and is connected to the lower side link via a cylindrical pair. 3. The delta according to claim 1, wherein, of the pair of lower arms, a lower arm disposed distally from the upper arm has lower strength than a lower arm disposed proximal to the upper arm. Type parallel robot.   Of the pair of lower arms, the lower arm disposed proximally to the upper arm has a notch recess that is removed in a direction away from the upper arm on a side surface of the base end near the lower arm. The delta type parallel robot according to any one of claims 1 to 3, further comprising:

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