CN209887586U

CN209887586U - (2PRU-PUR) -PP five-axis linkage hybrid robot

Info

Publication number: CN209887586U
Application number: CN201920275968.3U
Authority: CN
Inventors: 李翔毅; 于雅雯; 李秦川; 徐灵敏; 胡佳鑫; 张佳恒
Original assignee: Zhejiang University of Technology ZJUT
Current assignee: Zhejiang University of Technology ZJUT; Zhejiang Sci Tech University ZSTU; Zhejiang University of Science and Technology ZUST
Priority date: 2019-03-05
Filing date: 2019-03-05
Publication date: 2020-01-03
Anticipated expiration: 2029-03-05

Abstract

The utility model belongs to the technical field of the robot. The purpose is to provide a (2PRU-PUR) -PP five-axis hybrid robot which can process complex free-form surface parts and has the advantages of high rigidity precision, good flexibility, high processing speed, large working space, relatively simple kinematics and easiness in control. The technical scheme is as follows: a (2PRU-PUR) -PP five-axis linkage hybrid robot comprises a fixed frame, a workbench with a clamp and a horizontal moving pair which is supported by the fixed frame and drives the workbench to move horizontally; the method is characterized in that: the fixed frame can also vertically movably position a parallel mechanism; the parallel mechanism comprises a movable platform with an electric spindle, a shell-shaped base movably positioned on the fixed frame through a vertical moving pair, and a first branched chain, a second branched chain and a third branched chain which are connected between the shell-shaped base and the movable platform in parallel.

Description

(2PRU-PUR) -PP five-axis linkage hybrid robot

Technical Field

The utility model belongs to the technical field of the robot, concretely relates to can satisfy aerospace field large-scale structure complex curved surface free machining's novel (2PRU-PUR) -PP five-axis linkage series-parallel robot.

Background

The mechanical structure of the traditional numerical control machine tool mostly adopts a series connection mode, and the motion output end of the traditional numerical control machine tool is easy to generate accumulated errors, low in integral rigidity, large in motion inertia and poor in dynamic response characteristic due to the series connection structure mode. In comparison, the novel machine tool based on the parallel mechanism appeared in the last 90 th century has the advantages of compact structure, high rigidity, no error accumulation, small moving part quality, easiness in realizing high-speed movement, higher dynamic response characteristic and the like, makes up for the defects of the traditional numerical control machine tool to a certain extent, meets the requirement of the mechanical machining field on high-speed cutting, and further obtains wide attention and research. However, the parallel machine tool also has inherent limitations, and particularly, the six-degree-of-freedom full parallel machine tool has the defects of strong kinematic coupling, small working space, complex kinematics, complex numerical control programming and the like, so that the parallel machine tool is limited to be widely popularized and applied. With the application of parallel mechanisms and the continuous development and progress of parallel mechanism science, parallel mechanisms with less degrees of freedom are more and more appreciated and favored by researchers. Compared with a fully parallel six-degree-of-freedom mechanism, the less-degree-of-freedom parallel mechanism has the advantages of simple kinematics, weak coupling, easiness in modularization and the like, and some less-degree-of-freedom parallel mechanisms are successfully applied in the industrial field.

In the field of machining, with the increasingly complex design of modern mechanical parts, the spatial free-form surface type parts have been widely applied to various key fields, such as aerospace, automobiles and the like. Such applications place higher demands on modern machining processes and manufacturing equipment, and thus, hybrid machines combining the advantages of both series machines and parallel machines have gained relatively wide use in the industry. The hybrid robot has the advantages of large working space and flexible movement of the serial mechanism, large rigidity of the parallel mechanism, strong bearing capacity, no accumulated error and the like, breaks through the limitation of a simple serial mechanism and a simple parallel mechanism, is more suitable for high-speed cutting processing of space free-form surface parts, and is an important direction for the research and development of the robot in the future. The five-axis linkage hybrid robot composed of the three-degree-of-freedom parallel mechanism and the two-degree-of-freedom series mechanism has unique advantages, is critical manufacturing equipment urgently needed by each key industry, and receives more and more attention.

The utility model discloses a patent (like CN 103240614B, CN 105666468B, CN 105690361B) of current series-parallel robot utility model, the inside articulated shaft of mechanism is virtual mostly, is unfavorable for realizing closed-loop control, and the hinge is in large quantity in the mechanism, influences the machining precision. Therefore, it is necessary to provide a five-axis linkage hybrid robot with high precision, high speed, high rigidity and easy control.

SUMMERY OF THE UTILITY MODEL

The utility model overcomes not enough among the above-mentioned background art, provided a can process the five series-parallel robot of (2PRU-PUR) -PP that the rigidity precision of complicated free-form surface class part is high, the flexibility is good, the process velocity is fast, workspace is big, the kinematics is simple relatively, control is easy.

The utility model provides a technical scheme is:

a (2PRU-PUR) -PP five-axis linkage hybrid robot comprises a fixed frame, a workbench with a clamp and a horizontal moving pair which is supported by the fixed frame and drives the workbench to move horizontally; the method is characterized in that: the fixed frame can also vertically movably position a parallel mechanism; the parallel mechanism comprises a movable platform with an electric spindle, a shell-shaped base movably positioned on the fixed frame through a vertical moving pair, and a first branched chain, a second branched chain and a third branched chain which are connected in parallel between the shell-shaped base and the movable platform;

the first branched chain and the second branched chain have the same structure and respectively comprise a moving pair, a rotating pair and a hook hinge which are sequentially connected between the shell-shaped base and the movable platform; in each branched chain, the rotation axis of the revolute pair is vertical to the axis of the revolute pair, and the first rotation axis of the Hooke's joint is parallel to the rotation axis of the revolute pair; in the first branched chain and the second branched chain, the first rotating axes of the two hook joints are coaxial, and the rotating axes of the two revolute pairs are parallel to each other;

the third branched chain sequentially comprises a third moving pair, a third hook hinge and a third rotating pair which are connected with the mounting base and the moving platform; and the rotation axis of the third revolute pair is parallel to one rotation axis of the third hook joint.

The axes of the three branched-chain sliding pairs P are parallel to each other and are horizontally arranged, and the axes of the three branched-chain sliding pairs P are also vertical to the axis of the horizontal sliding pair.

The axes of the guide rods of the sliding pairs in the three branched chains also form a cylinder with an isosceles right triangle cross section.

In the first branched chain and the second branched chain, the moving pair is an active driving pair; in the third branched chain, the third moving pair is an active driving pair.

The horizontal moving pair and the vertical moving pair are also active driving pairs.

The input drive of the active drive pair is realized by driving a ball screw to drive a moving pair by a servo motor.

Compared with the prior art, the beneficial effects of the utility model are that: the parallel mechanism adopted by the hybrid robot realizes the design of the minimum number of hinges at present, meets the five-axis linkage numerical control machining requirement of complex free-form surface parts, and has the advantages of high rigidity precision, good flexibility, high machining speed, large working space, relatively simple kinematics, easiness in control and the like.

Drawings

Fig. 1 is a schematic perspective view of an embodiment of the present invention.

Fig. 2 is a schematic perspective view of the parallel mechanism in fig. 1.

Fig. 3 is a schematic perspective view of the first branched chain in the parallel mechanism shown in fig. 2.

Fig. 4 is a schematic perspective view of a second branched chain in the parallel mechanism shown in fig. 2.

Fig. 5 is a schematic perspective view of a second branched chain in the parallel mechanism shown in fig. 2.

The figure shows that: 2. the parallel mechanism comprises a parallel mechanism, 3, a workbench, 4, a fixed frame, 11, an X-guide rail, 12, a Z-guide rail, 21, a shell-shaped base, 22, a movable platform, 23, an electric spindle, 24, a first branched chain, 25, a second branched chain, 26, a third branched chain, 241, a first sliding block, 242, a first connecting rod, 243, a first moving pair, 244, a first rotating pair, 245, a first Hooke hinge, 251, a second sliding block, 252, a second connecting rod, 253, a second moving pair, 254, a second rotating pair, 255, a second Hooke hinge, 261, a third sliding block, 262, a third connecting rod, 263, a third moving pair, 264, a third Hooke hinge, 265 and a third rotating pair.

Detailed Description

The invention will be further explained with reference to the following embodiments shown in the drawings.

The (2PRU-PUR) -PP five-axis linkage hybrid robot shown in fig. 1 (wherein P represents a kinematic pair, R represents a revolute pair, U represents a hooke joint, and P represents that the kinematic pair is an active driving pair) includes: a fixed frame 4, a worktable 3 with a clamp, a horizontal moving pair supported by the fixed frame and driving the worktable to move horizontally (to move parallel to the X-axis direction), and a parallel mechanism 2 positioned on the fixed frame in a vertically movable manner (to move parallel to the Z-axis direction) through the vertical moving pair. The horizontal moving pair comprises an X-direction guide rail 11 and an X-direction slider matched with the X-direction guide rail in a sliding manner, and the vertical moving pair comprises a Z-direction guide rail 12 and a Z-direction slider matched with the Z-direction guide rail in a sliding manner; the horizontal moving pair and the vertical moving pair are both driving pairs. The horizontal moving pair and the vertical moving pair form a series mechanism.

As shown in fig. 2, the parallel mechanism includes a shell-shaped base 21 (in the figure, the shell-shaped base is simplified into three rod-shaped bases connected into a whole for convenience of illustration), a movable platform 22 with an electric spindle 23, and a first branch chain 24, a second branch chain 25 and a third branch chain 26 connected between the shell-shaped base 21 and the movable platform 22; the one-dimensional movement of the movable stage 22 in the Y-axis direction (horizontal direction) can be achieved by input drive in three branched chains. The shell-shaped base 21 is connected to a Z-direction slider engaged with the Z-direction rail 12 (the Z-direction rail 12 and the Z-direction slider engaged therewith form a vertical moving pair), and a drive (the vertical moving pair includes the drive, which is omitted in the drawing) for sliding the parallel mechanism 2 in the Z-axis direction is added in the Z-axis direction.

As shown in fig. 2, 3 and 4, the first branched chain 24 and the second branched chain 25 have the same structure and are symmetrically distributed in spatial position, and respectively include

sliders

241 and 251, connecting

rods

242 and 252 having the same structure, and kinematic pairs having the same structure; three kinematic pairs are provided for each branched chain, taking the first branched chain 24 as an example (the second branched chain has the same structure), one is a first kinematic pair 243 (including a first guide rod fixed on the mounting base and a first sliding block 241 slidably engaged with the guide rod) connected between the mounting base 21 and the first rotary pair 244, one is the first rotary pair 244 connected between the first sliding block 241 and the first connecting rod 242, and one is a first hooke hinge 245 connected between the first connecting rod 242 and the movable platform 22, and the branched chain is a PRU branched chain; the rotation axis of the first rotating pair 244 is perpendicular to the axis of the first moving pair 243; the first rotation axis of the first hooke joint 245 is parallel to the rotation axis of the first rotation pair 244; in the two PRU branched chains, one rotating axis of two Hooke joints is coaxial, and the rotating axes of two rotating pairs are parallel to each other.

As shown in fig. 2 and 5, the third branched chain 26 includes a third slider 261, a third link 262 and a kinematic pair; the number of the kinematic pairs is three, one is a third kinematic pair 263 (including a third guide rod and a third slider 261 slidably engaged with the third guide rod) connected between the mounting base 21 and the third hooke joint 264, the other is the third hooke joint 264 connected between the third slider 261 and the third link 262, and the other is a third revolute pair 265 connected between the third link 262 and the movable platform 22, the branched chain is a PUR branched chain, wherein the kinematic pair connected between the mounting base 21 and the third hooke joint 264 is an active driving pair; the rotation axis of the third revolute pair 265 is parallel to one of the rotation axes of the third hooke's joint 264.

As shown in fig. 2, the movable platform 22 is an isosceles right triangle ABC, in which ═ BAC is 90 ° and AB is AC. The axes of the moving pairs of the three branched chains are always parallel to each other and are horizontally arranged (arranged parallel to the Y axis). The axes of the guide rods of the sliding pairs in the three branched chains also form a cylinder (imaginary) with the cross section of an isosceles right triangle; namely: any plane perpendicular to the axes of the moving pair in the three branched chains and three intersection points of the axes of the guide rods in the moving pair form an isosceles right triangle; in the isosceles right triangle, the intersection point on the third guide rod is the vertex of a right angle in the right triangle, and the two intersection points on the first guide rod and the second guide rod are the vertexes of two acute angles of the right triangle respectively; the line connecting the vertices of the two acute angles is also arranged horizontally.

In the utility model, all the sliding pairs are driving pairs, and the driving pairs are driven by a ball screw mechanism driven by a servo motor; when the moving pair moves, the relative motion effect of five-axis linkage between the moving platform 22 of the parallel mechanism 2 and the workbench 4 can be realized; the fixture on the workbench is used for clamping a workpiece to be machined, and the electric spindle is provided with a cutter for machining, so that a complete machining chain is formed.

Claims

1. A (2PRU-PUR) -PP five-axis linkage hybrid robot comprises a fixed frame (4), a workbench (3) with a clamp and a horizontal moving pair which is supported by the fixed frame and drives the workbench to move horizontally; the method is characterized in that: the fixed frame can also vertically movably position a parallel mechanism (2); the parallel mechanism comprises a movable platform (22) with an electric spindle (23), a shell-shaped base (21) movably positioned on the fixed frame through a vertical moving pair, and a first branched chain (24), a second branched chain (25) and a third branched chain (26) which are connected between the shell-shaped base and the movable platform in parallel;

the first branched chain and the second branched chain have the same structure and sequentially comprise a moving pair, a rotating pair and a hook hinge which are connected between the shell-shaped base and the movable platform; in each branched chain, the rotation axis of the revolute pair is vertical to the axis of the revolute pair, and the first rotation axis of the Hooke's joint is parallel to the rotation axis of the revolute pair; in the first branched chain and the second branched chain, the first rotating axes of the two hook joints are coaxial, and the rotating axes of the two revolute pairs are parallel to each other;

the third branched chain comprises a third moving pair (263), a third hook joint (264) and a third rotating pair (265) which are connected with the mounting base and the moving platform in sequence, and the rotating axis of the third rotating pair is parallel to one rotating axis of the third hook joint.

2. The (2PRU-PUR) -PP five-axis linkage hybrid robot according to claim 1, wherein: the axes of the three branched chain moving pairs are parallel to each other and are horizontally arranged, and the axes of the three branched chain moving pairs are also vertical to the axis of the horizontal moving pair.

3. The (2PRU-PUR) -PP five-axis linkage hybrid robot according to claim 2, wherein: the axes of the guide rods of the sliding pairs in the three branched chains also form a cylinder with an isosceles right triangle cross section.

4. The (2PRU-PUR) -PP five-axis linkage hybrid robot according to claim 3, wherein: in the first branched chain and the second branched chain, the moving pair is an active driving pair; in the third branched chain, the third moving pair is an active driving pair.

5. The (2PRU-PUR) -PP five-axis linkage hybrid robot according to claim 3, wherein: the horizontal moving pair and the vertical moving pair are also active driving pairs.

6. The (2PRU-PUR) -PP five-axis linkage hybrid robot according to claim 4 or 5, wherein: the input drive of the active drive pair is realized by driving a ball screw to drive a moving pair by a servo motor.