WO2005025816A1

WO2005025816A1 - A robot with five-freedom mix couple structure

Info

Publication number: WO2005025816A1
Application number: PCT/CN2004/000479
Authority: WO
Inventors: Tian Huang; Meng Li; Zhanxian Li; Jiangping Mei; Xueman Zhao; Dawei Zhang
Original assignee: Tianjin University
Priority date: 2003-09-16
Filing date: 2004-05-14
Publication date: 2005-03-24
Also published as: CN100446940C; WO2005025816A8; CN1524662A

Abstract

A robot with five-freedom mix couple structure is disclosed, which comprises a fixed frame, a first setting adjustable in length, a second setting adjustable in length, a third setting adjustable in length, a positioning head, a movable table. Thereinto, a first hinge is provided in the middle of the fixed frame. The top of the first setting is mounted on the fixed frame via the first hinge and a shift pair that is formed by the first setting and the first hinge, the end of which connects the movable table. A second hinge and a third hinge are provided symmetrically on an end face of the fixed frame, the tops of them are mounted respectively and symmetrically on the end face of the fixed frame, and the ends connect apart with the movable table. The invention can be designed in modularization and used conveniently; the amount of moving components can be reduced, which can avoid the interference among moving components. The end performer can move with five-freedom and holds the performance of high speed, high precision, high rigidity and the trait of broad working space.

Description

5-DOF Hybrid Robot

The invention relates to a robot, in particular to a five-degree-of-freedom hybrid robot with an asymmetric structure.

Background technique

Existing spatial hybrid robots with positioning heads are known from patent applications GB2173472 (or EP0200369. US4790718) SE8502327 (or US4732525), EP0674969 (or US6336375), including at least three axially extendable or shortenable Adjusting device; one end of the adjusting device is connected to the fixing frame through a hinge so that it can rotate in various directions relative to the fixing frame, and the other end of the adjusting device is connected to the moving platform through a hinge; there is an additional driven branch chain in the structure; One end of the driven branch chain is fixedly connected to the moving platform, and the other end is connected to the fixed frame through a hinge to limit certain degrees of freedom of the moving platform. In the structure of this type of robot, there are passive sliding and / or rotating devices, the mechanism is complicated, and interference between components is easy to occur during the movement.

Summary of the invention

The technical problem to be solved by the present invention is to provide a reconfigurable and modular five-degree-of-freedom hybrid robot that can ensure the characteristics of high speed, high precision, high rigidity, and large working space, and can minimize the number of components. .

The technical solution adopted by the present invention is: a five-degree-of-freedom hybrid robot, which includes a fixed frame, a first length adjustment device, a second length adjustment device, a third length adjustment device, a positioning head, and a moving platform. The middle part of the fixed frame is provided with a first hinge, and the upper part of the first length adjusting device is provided on the fixed frame through the first hinge and the sliding pair formed with the first hinge, and the end is connected to the movable platform; Second and third hinges are symmetrically arranged on both sides of one end surface of the end, and the upper parts of the second and third length adjusting devices are symmetrically arranged on the fixing frame through the second and third hinges, respectively. On both sides of the end face, their ends are hinged to the moving platform, respectively; the positioning head is connected to the bottom of the moving platform.

The first length adjusting device includes: a tubular structure with a slotted hole on the back, a lead screw provided inside the tubular structure, and a lead screw nut forming a movement pair with the lead screw. The outer peripheral surface of the tubular structure is provided with two in the axial direction. guide.

The first hinge includes an inner ring and an outer ring. The inner ring and the outer ring are connected by two left and right co-rotational shafts. The outer ring is connected with the fixed frame by two front and back co-rotational shafts. Two sliding blocks are provided. The two sliding blocks and two guide rails outside the tubular structure in the first length adjusting device constitute the sliding pair.

The distribution of the two hinges on the moving platform is one of three forms, which are: (1) the centers of movement of the two hinges coincide; (2) the centers of movement of the two hinges are symmetrically located on the axis of symmetry of the moving platform (21c ) On both sides; (3) The movement centers of the two hinges (32, 42) are distributed in a triangle with respect to the axis of symmetry (21c) of the moving platform (5).

The driving form of the three length adjusting devices can be any one of a motor-lead screw / threaded spline shaft structure, a linear motor structure, a hydraulic structure or a pneumatic structure. '' Because the present invention has a modular design, it can be connected to a fixed gantry structure, a large-distance or large-angle feed mechanism, and a movable rack through a mechanical interface on the fixed frame. Several robots of the present invention can also be installed on the same fixed Structural joint operations.

Compared with the prior art, the five-degree-of-freedom hybrid robot of the present invention reduces one driven branch chain, and its beneficial effects are:

(1) Reduce the number of moving components, reduce the complexity of the mechanism, and reduce the interference of its components during the movement;

(2) It has the characteristics of high speed, high precision, high rigidity and large working space. In some cases, it can be used as a CNC machine tool or machining center;

(3) Modular design, which can be connected or combined with other mechanisms through the fixed frame, that is, Plug and play

(4) The modular design makes it not only possible to use it alone, but also several units to work together to form rebuilt manufacturing or assembly units and systems.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of the overall structure of the present invention;

Figure 2 is a front view of Figure 1;

Figure 3 is a side view of Figure 1;

4 is a schematic structural diagram of a fixing frame and a hinge connected thereto in an embodiment of the present invention; FIG. 5 is a schematic structural diagram of a first length adjusting device in an embodiment of the present invention; FIG. 6 is a positioning head of two Schematic diagram of the rotation degree of freedom sub-module. among them:

1: fixed frame 2: first length adjusting device

3: second length adjusting device 4: third length adjusting device

5: Moving platform 6: Positioning head

21: First hinge 22: Inner ring

23: outer ring 24: slider

25: Rail 26: Tubular structure

27: Lead screw 28: Lead screw nut

31: second hinge 33, 43: outer sleeve

34, 44: inner sleeve 32, 42: hinge

41: Third hinge 61: First frame

62: The second frame

21a, 21b, 21c, 31a, 41a, 31b, 41b, 6a: axes

detailed description

The present invention is described in detail below with reference to the drawings and specific embodiments. As shown in FIG. 1, FIG. 2, and FIG. 4, the five-degree-of-freedom hybrid robot of the present invention includes a fixed frame 1, a first length adjustment device 2, a second length adjustment device 3, a third length adjustment device 4, and a moving platform. 5 和 locating head 6. The upper part of the first length adjusting device 2 is arranged in the middle of the fixing frame 1 through a first hinge 21, and its end is rigidly connected to the movable platform 5. The upper parts of the second length adjusting device 3 and the third length adjusting device 4 are respectively symmetrically provided. The second hinge 31 and the third hinge 41 on both sides of the front side of the fixed frame 1 are connected to the fixed frame 1, and their ends are respectively connected to the moving platform 5 through hinges 32 and 42 having three degrees of freedom of rotation; the bottom of the moving platform 5 Connected to positioning head 6.

In this mechanism, the first, second, and third length adjusting devices 2, 3, and 4 can be extended or shortened in the axial direction, and the first, second, and third hinges 21, 31, and 41 each have at least two Rotation degree of freedom, so that each length adjusting device can be rotated in all directions relative to the fixed frame 1. The end of the first length adjusting device 2 is rigidly connected to the moving platform 5, so that when the moving platform 5 undergoes spatial displacement, its mechanism The space attitude also changes at the same time; the positioning head 6 with two rotational degrees of freedom can adjust the attitude change caused by the position change of the moving platform 5 at any time during the movement, and various actuators such as cutters, powerful Gun, holding device, etc.

The structure of the three length adjusting devices can be set in two ways, namely:

(1) the second length adjusting device 3, the third length adjusting device 4 and the first length adjusting device 2 have the same structure;

(2) The second length adjusting device 3 and the third length adjusting device 4 have the same structure, and the structure of the first length adjusting device 2 is different from the two.

In this embodiment, since the first length adjusting device 2 is rigidly connected to the moving platform 5, the second length adjusting device 3 and the third length adjusting device 4 are hinged to the moving platform 5 through the three-degree-of-freedom hinges 32, 42, thus acting Most of the external forces and external moments on the positioning head 6 or the moving platform 5, especially the torsional moment, will be directly transmitted to the first length adjusting device 2, so that the first length adjusting device 2 and the second and third length adjusting devices 3, 4 requires a higher torsional stiffness. therefore, If the first setting method is adopted, so that the three length adjusting devices have the same structure, it cannot guarantee that the torsional torque is effectively transmitted to the mechanical structure connected to the fixed frame 1. Therefore, although this setting method can simplify the design and manufacturing of the robot, it is not desirable from the perspective of improving the rigidity of the whole machine. In order to improve the rigidity of the whole machine, this embodiment adopts a second setting mode, that is, the first length adjustment device 2 rigidly connected to the moving platform 5 and the other two length adjustment devices 3 and 4 have different mechanical structures. It can be seen from FIG. 1 that the first length adjustment device 2 has a larger radial dimension than the second and third length adjustment devices 3 and 4. At the same time, the first length adjustment device 2 is axially opposed to the entire length adjustment device 2. The fixed frame 1 and the first hinge 21 slide in the form of a rigid arm to achieve length adjustment. This arrangement can make the first length adjusting device 2 have sufficient rigidity to bear its own weight, and transmit the torsional moment to the fixed frame 1 through the guide rail 25 and the first hinge 21.

As shown in FIG. 5, the first length adjusting device 2 includes a tubular structure 26 with a slotted hole on the back, a lead screw 27 located inside the tubular structure 26, and a movement pair that forms a movement pair with the lead screw 27 and communicates with the first hinge 21. A screw nut 28 rigidly connected to the inner ring 22 is provided with two guide rails 25 along the axial direction on the outside of the tubular structure 26. Driven by a motor, the tubular structure 26, together with the motor and the screw 27, moves axially relative to the screw nut 28. In addition, in order to make the first length adjusting device 2 have sufficient rigidity to withstand the torsional moment as before, in addition to making the outer diameter of the first length adjusting device 2 larger than that of the second and third length adjusting devices 3 and 4, The two ends of the slotted hole in the tubular structure 26 are closed, and a reinforcing rib is provided on the inner wall of the tubular structure 26.

As shown in FIG. 4, the first hinge 21 provided between the first length adjusting device 2 and the fixing frame 1 is composed of two inner and outer concentric rings 22 and 23. The outer diameter of the first length adjusting device 2 (or the tubular structure 26) is slightly smaller than the inner diameter of the inner ring 22. The inner wall of the inner ring 22 is provided with two sliders 24 symmetrically. The two sliders 24 and the first length adjusting device 2 The two guide rails 25 provided on the outer diameter of the outer ring constitute a sliding pair, so that the length adjusting device 2 can slide in the axial direction relative to the inner ring 22; One length adjustment device 2 and inner ring 22 The outer ring 23 can be rotated around the axis 21a relative to the outer ring 23 at the same time; the outer ring 23 is movably connected to the fixed frame 1 through two collinear front and rear rotating shafts, so that the first length adjusting device 2 and the inner and outer rings 22 and 23 can be simultaneously fixed relative to the fixed frame 1 Rotate around the axis 21b. Therefore, the first length adjusting device 2 can be rotated in various directions relative to the fixed frame 1 and slide along the axial direction to achieve length adjustment.

The structures of the second length adjusting device 3 and the third length adjusting device 4 are the same. As shown in FIG. 3, they include outer sleeves 33, 43, inner sleeves 34, 44, and a lead screw located inside the sleeve and a wire. The rod constitutes a lead screw nut of the movement pair and is connected to the inner sleeves 34 and 44. Driven by a motor, the screw nut and the inner sleeve 34, 44 can move axially relative to the outer sleeves 33, 43.

As shown in FIG. 4, a second hinge 31 and a third hinge 41 are symmetrically provided on both sides of one end surface of the fixing frame 1, and both are fork-shaped structures, and the outer tube of the second length adjusting device 3 and the third length adjusting device 4. 33 and 43 are connected to the second hinge 31 and the third hinge 41 through the rotating shafts on the second hinge 31 and the third hinge 41, respectively, so that the second length adjusting device 3 and the third length adjusting device 4 can be opposite to the second hinge, respectively. 31. The third hinge 41 rotates about the axes 31a and 41a; the second hinge 31 and the third hinge 41 are connected to the fixing frame 1 through a rotating shaft, so that the second length adjusting device 3 and the third length adjusting device 4 can be connected to the second length adjusting device 3 again. The hinge 31 and the third hinge 41 are simultaneously rotated around the axes 31 b and 41 b with respect to the fixed frame 1. Therefore, the second length adjusting device 3 and the third length adjusting device 4 can be rotated in various directions relative to the fixed frame 1.

In this embodiment, the three length adjusting devices adopt a motor-screw driving structure. In some cases, any one of the motor's threaded spline shaft structure, linear motor structure, hydraulic structure or pneumatic structure can be used as its driving mode.

The center of movement of the two hinges 32, 42 between the moving platform 5 and the second and third length adjusting devices 3, 4 is relative to the axis of symmetry of the moving platform 5 (also the axis of symmetry 21c of the first length adjusting device 2) Has three distribution forms:

(1) The centers of motion of the two hinges 32, 42 coincide;

(2) The centers of movement of the two hinges 32, 42 are located symmetrically on both sides of the axis of symmetry 21c, respectively; (3) The movement centers of the two hinges 32, 42 are located at other positions.

When the distribution form is (3), the centers of movement of the two hinges 32, 42 are triangularly distributed with respect to the symmetry axis 21c of the moving platform 5. This distribution form ensures that the present invention has a high rigidity in all directions, so that it can be applied to practical operation in any form.

As shown in FIG. 6, the positioning head 6 is a sub-module design, and is composed of a first frame 61 and a second frame 62. The first frame 61 is connected to the moving platform 5 through a rotating shaft, and can rotate relative to the moving platform 5 about the axis 21 c. The two frames 62 and the first frame 61 are connected through a rotating shaft, and can rotate relative to the first frame 61 about an axis 6a, and the axis 6a is perpendicular to the axis 21c. In this embodiment, an electric spindle is installed at the end of the positioning head 6.

In summary, the five-degree-of-freedom hybrid robot of the present invention has a modular design and includes three length adjustment devices that can be extended or shortened in the axial direction. The upper part of the first length adjustment device 2 passes through the two-degree-of-freedom hinge 21 The sliding pair composed of the hinge inner ring 22 and the guide rail 25 on the outer wall of the first length adjusting device 2 is connected to the fixing frame 1, and the lower end of the first length adjusting device 2 is fixedly connected to the moving platform 5. The upper parts of the second and third length adjusting devices are respectively connected to the fixing frame 1 through two-degree-of-freedom hinges 31 and 41, and the lower ends are hinged to the movable platform 5 through three-degree-of-freedom hinges 32 and 42 respectively. In this manner, the first length adjusting device 2 can be rotated in various directions relative to the fixing frame 1 and slide in the axial direction, and the second length adjusting device 3 and the third length adjusting device 4 are also relative to the fixing frame 1 Realize rotation in all directions, and extend or shorten in the axial direction. Since the positioning head 6 with two rotational degrees of freedom is mounted on the moving platform 5, the end effector can achieve five degrees of freedom.

Due to the modular design of the present invention, it can be connected to a fixed gantry structure, a large-distance or large-angle feed mechanism, and a movable rack through a mechanical interface on the fixed frame 1. It is also possible to install several robots of the present invention on the same fixed structure On joint operations.

The above description of the present invention and its embodiments is schematic and not restrictive. What is shown in the drawings is only one of the embodiments of the present invention, and the actual structure is not limited to this. and so, If a person of ordinary skill in the art is inspired by it, without departing from the purpose of the present invention, the embodiments made by using other structures such as the layout of the fixing frame, the length adjustment device, the hinge, and the positioning head should all belong to the present invention. The scope of protection of the invention.

Claims

Claim

1. A five-degree-of-freedom hybrid robot, comprising a fixed frame (1), a first length adjusting device (2), a second length adjusting device (3), a third length adjusting device (4), and a positioning head (6) ); Characterized in that: a moving platform (5) is further provided, wherein a middle portion of the fixing frame (1) is provided with a first hinge (21), and an upper portion of the first length adjusting device (2) passes through the first hinge (21) ) And the sliding pair formed with the first hinge are arranged on the fixed frame (1), and the end is connected with the movable platform (5); the second and third sides of one end surface of the fixed frame (1) are symmetrically arranged The hinge (31, 41), the second and third length adjustment devices. The upper part of (3, 4) is symmetrically arranged on the two sides of the end face of the fixed frame (1) through the second and third hinges (31, 41), respectively. Their ends are hinged to the moving platform (5) respectively; the positioning head (6) is connected to the bottom of the moving platform (5).

2. The five-degree-of-freedom hybrid robot according to claim 1, characterized in that: said first length adjusting device (2) comprises: a tubular structure (26) with a slotted hole on the back, and a tubular structure (26) The internal lead screw (27) and the lead screw nut (28) forming a movement pair with the lead screw (27) are formed. The outer peripheral surface of the tubular structure (26) is provided with two guide rails (25) in the axial direction.

3. The five-degree-of-freedom hybrid robot according to claim 1, wherein: the first hinge (21) comprises an inner ring (22) and an outer ring (23), and the inner ring (22) and The outer ring (23) is connected by its two left and right collinear rotating shafts, the outer ring (23) is connected with the fixed frame (1) by two front and rear collinear rotating shafts, and the inner wall of the inner ring (22) is symmetrically provided with two left and right sides. The two sliding blocks (24), two sliding blocks (24), and two guide rails (25) outside the tubular structure (26) in the first length adjusting device (2) constitute the sliding pair.

The five-degree-of-freedom hybrid robot according to claim 1, characterized in that: the distribution of the two hinges (32, 42) on the moving platform (5) is one of three forms, the three of which are: This form is:

(1) The motion centers of the two hinges (32, 42) coincide; (2) The centers of movement of the two hinges (32, 42) are symmetrically located on both sides of the axis of symmetry (21c) of the moving platform (5);

(3) The centers of motion of the two hinges (32, 42) are distributed in a triangle with respect to the axis of symmetry (21c) of the moving platform (5).

5. The five-degree-of-freedom hybrid robot according to claim 1, characterized in that: the driving method of the three length adjustment devices (2, 3, 4) can adopt a motor-lead screw / threaded spline shaft structure , Linear motor structure, hydraulic structure or pneumatic structure.