CN106493582B - A kind of three translation parallel lathe of big working space adding the sliding of two redundancies - Google Patents

Abstract

The invention discloses a three-translational parallel machine tool with two redundant slides and a large working space, which includes a machine frame, a longitudinal linear module, a horizontal two-linked linear module, a first branch chain group, a second branch chain group, a second branch chain group, and a Three branch chain groups, moving platform, and workbench; one end of the first branch chain group, the second branch chain group, and the third branch chain group are respectively connected with the fourth slider, the fifth slider, and the third slider, and the other end They are all connected to the moving platform, and each branch chain group is connected to the longitudinal linear module, the horizontal two-linkage linear module or the moving platform through the ball joints at both ends, forming a space parallel closed-loop structure; the horizontal two-linkage linear module and the vertical linear module Cross-mounted on the frame; through the three translational motions of the three branch chains, the vertical linear module, and the horizontal two-linkage linear module to drive the movement of the platform, the large processing range of the machine tool is realized; the invention provides a flexible movement and compact structure. , It is a three-translational parallel machine tool that can avoid singularities and has a large working space, especially suitable for processing large workpieces.

Description

A triple-translational parallel machine tool with large working space and two redundant slides

technical field

The invention belongs to the field of numerical control manufacturing equipment, in particular to a three-translation parallel machine tool with large working space and two redundant slides.

Background technique

In the field of grand manufacturing, traditional single-column boring and milling machines, large gantry milling machines and other types of machine tools are difficult to meet the processing requirements of today's large workpieces due to problems such as poor dynamic performance, low precision, large body and high cost. As a new concept machine tool, parallel machine tool has its unique advantages compared with traditional CNC machine tools, such as high rigidity, large bearing capacity, fast response speed, and strong environmental adaptability.

Chinese patent CN105818137A discloses a parallel mechanism with three-dimensional translation, including a moving platform, a fixed platform and three sets of branch chains. The mechanism uses three servo motors to synchronously drive a set of retractable branch chains. The disadvantage is that the working space of the mechanism is small , not suitable for large-scale work; Chinese patent CN103240729A discloses a three-translational parallel manipulator in space, including a fixed frame, a moving platform, and three branch chain groups symmetrically arranged between the fixed frame and the moving platform. The chain is divided into near frame rods and far frame rods to form a space-axisymmetric multi-link structure. The limitation is that the rigidity is poor and the working space is small; the Pegasus wood processing center launched by the German Reichenbacher company uses three sets of fixed rods that are long and The two ends of the rod system are equipped with universal hinges. The rod system is connected to the three mobile slides and the moving platform by means of the hinges. The disadvantage is that the working space is narrow and long, and the rigidity and precision cannot meet the requirements for the processing of large metal workpieces; the University of Stuttgart and the University of Stuttgart in Germany The Gantry-Tau parallel robot jointly researched by the University of Queensland in Australia, Agde College in Norway and ABB in Sweden adopts the layout of fixed-length rods and three sliding seats. One sliding seat has a set of parallel rods and one sliding seat. Three rods form two parallelograms, a rod is installed on the third sliding seat, and three horizontal guide rails are fixed on the frame. By planning the movement of the three sliding seats, the moving platform is converted from the left space to the right space, thus comparing Other parallel mechanisms have a larger working space. However, there are two problems with this mechanism: first, the length of the guide rail must be increased in order to obtain a larger working space, and the lateral working range of the mechanism is small; second, the trajectory planning of the moving platform in the left and right spaces is extremely complicated, and The available paths are limited. Zhang Chuanxu. Research on the overall technology of C-shaped gantry parallel machine tool [D]. Nanjing: Nanjing University of Science and Technology, 2013, Shen Xiaojian. Design and optimization of the frame structure of parallel C-shaped gantry milling machine [D]. Nanjing: Nanjing University of Science and Technology, 2015 respectively published A C-shaped gantry parallel machine tool is a large-space parallel machine tool formed by adding redundant linear sliding to the asymmetric three-translational 3-(2SPS) parallel mechanism. The upper branch chain seat and the lower branch chain seat are fixed, and the moving platform cannot reach the vicinity of the branch chain seat, that is, the top and bottom of the working space are narrow, and the entire working space is very irregular, which affects the processing adaptability of the machine tool to high or low workpieces , Machine tool performance optimization is also limited.

Contents of the invention

The technical problem to be solved by the present invention is to provide a three-translational parallel machine tool with flexible movement, compact structure, avoidance of singular configuration, large and regular working space, which is especially suitable for processing large workpieces.

The technical solution that realizes the object of the present invention is:

A three-translational parallel machine tool with two redundant slides and a large working space, including a frame, a vertical linear module, a horizontal two-linkage linear module, the first branch chain group, the second branch chain group, and the third branch chain group , a moving platform and a workbench; the frame includes an upper support, a main column, and a lower support; the longitudinal linear module includes a fifth guide rail and a fifth slider;

The upper end of the main column is installed with an upper support, the lower end of the mounting plate of the main column is equipped with a lower support, and the other end of the lower support is connected to the workbench; the longitudinal linear module is installed on the main column, and the fifth slider is along the The five guide rails slide parallel to the workbench horizontally; the horizontal two-linkage linear module includes a third slider, a fourth slider, a third guide rail, and a fourth guide rail; the third guide rail is fixedly connected to the lower support, and the second The three sliders slide along the third guide rail and slide up and down relative to the lower support; the fourth guide rail is fixedly connected with the upper support, and the fourth slider slides along the fourth guide rail and slides up and down relative to the upper support;

One end of the first branch chain group, the second branch chain group and the third branch chain group are respectively connected with the fourth slider, the fifth slider and the third slider, and the other ends are all connected with the moving platform.

Compared with the prior art, the present invention has significant advantages:

(1) The design of the open frame is conducive to the realization of a larger working space for the parallel machine tool;

(2) The parallel mechanism with few degrees of freedom is simple and compact in structure, easy to assemble, and the whole machine is light in weight and easy to control;

(3) According to the pose description and space coordinate transformation theory of the parallel machine tool, since the machine tool performs translation in three directions and has no rotational degree of freedom, the attitude matrix is a unit matrix, and the kinematics positive solution is relatively easy;

(4) The additional redundant linear modules are used to expand the range of motion of the moving platform, while the frame and workbench are fixed, thereby reducing the space occupied by the machine tool;

(5) The design of additional two redundant slides is beneficial to avoid singularities, improve the kinematic performance and stiffness of parallel machine tools, and is conducive to increasing the working space of parallel machine tools, so that the working space is regular and can meet the processing of large workpieces requirements.

Description of drawings

Fig. 1 is a schematic diagram of the three-dimensional structure of the machine tool of the present invention.

Fig. 2 is a schematic diagram of the frame structure of the present invention.

Fig. 3 is a schematic diagram of the horizontal two linkage linear modules of the present invention.

Fig. 4 is a schematic diagram of the mechanism of the machine tool of the present invention.

Fig. 5 is a schematic diagram of the three-dimensional structure of the moving platform of the present invention.

Fig. 6 is a schematic view of the structure of the Hooke hinge with additional rotating pair type spherical hinge according to the present invention.

Fig. 7 is a schematic diagram of the hooke hinge of the present invention with additional revolving pair type spherical hinge mechanism.

Detailed ways

Below in conjunction with Fig. 1 to Fig. 7, the present invention will be further described:

In combination with Fig. 1, a three-translational parallel machine tool with two redundant slides and a large working space in the present invention includes a frame 1, a longitudinal linear module 2, a horizontal two-linkage linear module 3, and a first branch chain group 4 , the second branch chain group 5, the third branch chain group 6, the moving platform 7 and the workbench 8;

The frame 1 includes an upper support 1-1, a main column 1-2, and a lower support 1-3; the longitudinal linear module 2 is a single-degree-of-freedom mobile pair, including a fifth guide rail 2-1 and a fifth guide rail 2-1. Five sliders 2-2; the upper end of the main column 1-2 is equipped with an upper support 1-1, the lower end of the mounting plate of the main column 1-2 is equipped with a lower support 1-3, and the other end of the lower support 1-3 Connected with the workbench 8; the longitudinal linear module 2 is installed in the middle of the main column 1-2, and the fifth slider 2-2 slides horizontally along the fifth guide rail 2-1 parallel to the workbench 8; the fifth slider 2-2 Two hinge holes for installing the second branch chain group 5 are arranged on the top;

The longitudinal linear module 2 is driven by a servo motor, thereby providing redundant linear sliding, which functions to avoid singularities and increase the working space of the machine tool;

The horizontal two-link linear module 3 includes a third slider 3-3, a fourth slider 3-4, a third guide rail 3-7, and a fourth guide rail 3-8;

The third guide rail 3-7 is fixedly connected with the lower support 1-3, and the third slider 3-3 slides up and down relative to the lower support 1-3 along the third guide rail 3-7; the fourth guide rail 3-8 is connected with the lower support 1-3. The upper support 1-1 is fixedly connected, and the fourth slider 3-4 slides up and down relative to the upper support 1-1 along the fourth guide rail 3-8; the third slider 3-3 and the fourth slider 3-4 are in the Sliding on the corresponding rail;

One end of the first branch chain group 4, the second branch chain group 5, and the third branch chain group 6 is respectively connected with the fourth slider 3-4, the fifth slider 2-2, and the third slider 3-3 , the other ends are all connected to the moving platform 7;

As a preferred embodiment, with reference to FIG. 2, the main column 1-2 is a cuboid cavity structure; the upper end is installed with an upper support 1-1, and the end of the main column 1-2 facing the workbench 8 is for installing a longitudinal linear module 2 and the mounting plate of the lower support 1-3, the lower end of the mounting plate is equipped with the lower support 1-3, and the other end of the lower support 1-3 is connected with the workbench 8; the upper support 1-1, the main column 1-2 Together with the lower support 1-3, it forms a C-shaped structure; the upper support 1-1 is a hexahedral cavity structure, and the lower end is connected with the upper end of the main column 1-2; the lower support 1-3 is a hexahedral cavity structure, and the opposite The main column 1-2 is symmetrical in the middle, and the symmetrical two ends are right-angled trapezoidal structures; the one connected to the main column 1-2 mounting plate is a larger rectangular structure, and the workbench 8 is installed as a smaller rectangular structure;

As a preferred embodiment, the angle between the upper support 1-1, the lower support 1-3 and the main column 1-2 in the working space is 120°; so that the third guide rail 3-7, the fourth guide rail 3 The included angle between -8 and the main column 1-2 in the vertical direction is 120°;

In some embodiments, referring to FIG. 3 , the horizontal two-link linear module 3 further includes a first slider 3-1, a second slider 3-2, a first guide rail 3-5, and a second guide rail 3-6 , push rod 3-9, first connecting rod 3-10, second connecting rod 3-11, rail connector 3-12;

The first guide rail 3-5 and the second guide rail 3-6 are all perpendicular to the workbench 8 and in the same vertical direction, the first guide rail 3-5 is fixedly connected with the main column 1-2, and the lower end extends into the lower support 1 -3; the second guide rail 3-6 is fixed on the guide rail connector 3-12, and the guide rail connector 3-12 is fixedly connected to the inside of the upper support 1-1; the first slider 3-1 and the second slider 3- 2 are connected by two push rods 3-9; the first slider 3-1 and the third slider 3-3 are provided with trunnion seats, which are used to hinge the first connecting rod 3-10, the first slider 3 -1. The third slider 3-3 is connected by the first connecting rod 3-10 to form a lower slider group; when the first slider 3-1 slides along the first guide rail 3-5, the first slider 3-1 1 The third slider 3-3 is driven to slide along the third guide rail 3-7 through the first connecting rod 3-10; the second slider 3-2 and the fourth slider 3-4 are provided with trunnion seats, and the As the second connecting rod 3-11 is hinged, the second sliding block 3-2 and the fourth sliding block 3-4 are connected by the second connecting rod 3-11 to form an upper sliding block group; when the second sliding block 3-2 moves along When the second guide rail 3-6 slides, the second slider 3-2 drives the fourth slider 3-4 to slide along the fourth guide rail 3-8 through the second connecting rod 3-11; Next, the upper slider group and the lower slider group form a linkage relationship, drive the first slider 3-1, and other sliders will move accordingly. The fourth slider 3-4 is provided with two hinge holes connecting the first branch chain group 4, and the third slider 3-3 is provided with two hinge holes connecting the third branch chain group 6;

The two horizontal linkage linear modules 3 are driven by a servo motor-screw nut, the screw nut drives the first slider 3-1 to slide, and the push rod 3-9 pushes the second slider 3-2 to move, so that the third slider The block 3-3 and the fourth slider 3-4 move accordingly; under the angular relationship of the guide rails, the trunnion on the first slider 3-1 is set to be between the third guide rail 3-7 and the first guide rail 3- 5. The intersection point is the initial position. When the first slider 3-1 and the second slider 3-2 slide upward from the initial position, the third slider 3-3 moves significantly, while the fourth slider 3-4 moves The distance is very small, on the contrary, when the first slide block 3-1 and the second slide block 3-2 slide down from the initial position, the fourth slide block 3-4 moves significantly, while the third slide block 3-3 moves a distance Very small, just because the driving of the first slider 3-1 causes the differential linkage of the third slider 3-3 and the fourth slider 3-4, this motion characteristic is used to fill the blind area of the machine tool, which is beneficial to increase The working space of the parallel machine tool makes the working space regular and can meet the requirements for processing large workpieces;

The fifth guide rail 2-1 of the vertical linear module 2 and the first guide rail 3-5 of the horizontal two linkage linear module 3 are vertically installed on the main column 1-2; the vertical linear module 2, the horizontal two linkage linear modules Group 3, where the longitudinal and transverse directions of the machine tool are defined by its coordinate system. In the horizontal direction, the machining range of the machine tool is large, which is defined as the longitudinal direction, and the vertical direction is correspondingly defined as the transverse direction;

As a preferred embodiment, with reference to Fig. 4, Fig. 6 and Fig. 7, the first branch chain group 4, the second branch chain group 5, and the third branch chain group 6 have the same structure, and each group of branch chain groups consists of two It consists of telescopic rods with the same structure; both ends of the telescopic rods are spherical hinges; the inside of the telescopic rods is driven by ball screws, and the two telescopic rods of each group of branch chains are always kept parallel and equal in length when the machine tool is working. The branch chain uses a servo motor to synchronously drive two telescopic rods;

In some embodiments, each group of branch chains uses two servo motors to drive two telescopic rods respectively;

As a further improvement to the above-mentioned embodiment, the spherical joint is an improved Hooke hinge. By adding a rotating pair to the base of the traditional Hooke hinge to replace the ordinary spherical joint, the rotation range can reach -70°— 70°;

One end of the two telescopic rods of the first branch chain group 4 is connected with the fourth slider 3-4 through a ball joint, and the other end is connected with the moving platform 7 through a ball joint; the two telescopic rods of the second branch chain group 5 One end of the telescopic rod is connected to the fifth slider 2-2 through a ball joint, and the other end is connected to the moving platform 7 through a ball joint; one end of the two telescopic rods of the third branch chain group 6 is connected to the The third slider 3-3 is connected, and the other end is connected with the moving platform 7 through a spherical joint, thereby forming a space parallel closed-loop structure;

As a preferred embodiment, in conjunction with Fig. 5, the moving platform 7 is a pentahedral cavity structure, and the connecting ends of the moving platform 7 and the first branch chain group 4 and the third branch chain group 6 are quadrilateral structures, and the two ends intersect And the included angle is 60°; the connecting end of the moving platform 7 and the first branch chain group 4 is provided with a first hinge hole 7-1 and a second hinge hole 7-2 for connecting the two telescopic rods of the first branch chain group 4 , the connecting line of the hole centers of the two holes is parallel to the connecting line of the hole centers connecting the two hinge holes of the first branch chain group 4 on the fourth slider 3-4 and the hole spacing is equal;

The connecting end of the moving platform 7 and the third branch chain group 6 is provided with the fifth hinge hole 7-5 and the sixth hinge hole 7-6 for connecting the two telescopic rods of the third branch chain group 6. The connection lines between the centers of the two hinge holes on the third slider 3-3 are parallel and the hole distances are equal;

Both ends of the connection between the moving platform 7 and the first branch chain group 4 and the third branch chain group 6 are provided with a convex table surface connected to the second branch chain group 5, and the two convex table surfaces are on the same plane, and are respectively provided with a second branch chain group. Three hinge holes 7-3 and the fourth hinge hole 7-4, the connection line of the center of the holes of the two holes is parallel to the connection line of the center of the holes of the two hinge holes on the fifth slider 2-2 and the hole spacing is equal; the opposite end parallel to the boss surface is Rectangular planar structure, and there is a mounting hole for installing the electric spindle of the working device in the middle; the other two end faces of the moving platform 7 are isosceles trapezoidal structures, which intersect with the convex table surface and the rectangular structure respectively;

The end face of the first branch chain group 4 installed on the moving platform 7 is kept parallel to the end face of the fourth slider 3-4, and the end face of the third branch chain group 6 is installed on the moving platform 7 and the end face of the third slider 3-3 Keep parallel, the end face of the second branch chain group 5 installed on the moving platform 7 is kept parallel to the end face of the fifth slider 2-2;

The main column 1-2, the lower support 1-3, and the workbench 8 of the frame 1 are all provided with anchor bolt mounting holes, and when the machine tool is installed, they are fixed by the anchor bolts to increase the overall stability of the machine tool; and the frame 1 and workbench 8 will not perform large-scale relative movement like traditional machine tools, which saves the occupied space of the machine tool and reduces the overall weight of the machine tool;

In the present invention, the angle between the upper support 1-1, the lower support 1-3 and the main column 1-2 in the working space can be properly adjusted; the moving platform 7 and the first branch chain group 4 and the third branch The angle between the two end faces of the chain group 6 is guaranteed: the end face of the first branch chain group 4 installed on the moving platform 7 is kept parallel to the end face of the fourth slider 3-4, and the third branch chain is installed on the moving platform 7 The end face of group 6 is kept parallel to the end face of the third slider 3-3, and the end face of the second branch chain group 5 installed on the moving platform 7 is kept parallel to the end face of the fifth slider 2-2, and the angle can be adjusted ;

Since the dynamic platform 7 of the parallel machine tool in the present invention has no attitude change, according to the pose description of the parallel machine tool and the theory of spatial coordinate transformation, since the machine tool performs translation in three directions and has no degree of freedom of rotation, the attitude matrix is a unit matrix, and the kinematics positive solution is also relatively easy;

Those skilled in the art of the present invention can make various changes and modifications without departing from the spirit and scope of the present invention. Under the condition of not departing from the gist of the present invention, relevant deformations made all belong to the scope of protection of the invention.

Claims (9)

1. A three-translational parallel machine tool with two redundant slides, characterized in that it includes a frame (1), a longitudinal linear module (2), a horizontal two-linkage linear module (3), a first chain group (4), the second branch chain group (5), the third branch chain group (6), the moving platform (7) and the workbench (8); the frame (1) includes the upper support (1- 1), the main column (1-2), the lower support (1-3); the longitudinal linear module (2) includes a fifth guide rail (2-1) and a fifth slider (2-2); The upper end of the main column (1-2) is equipped with an upper support (1-1), the lower end of the mounting plate of the main column (1-2) is equipped with a lower support (1-3), and the lower support (1-3) The other end of the workbench (8) is connected; the longitudinal linear module (2) is installed on the main column (1-2), and the fifth slider (2-2) is parallel to the fifth guide rail (2-1) The workbench (8) slides horizontally; the horizontal two-link linear module (3) includes a third slider (3-3), a fourth slider (3-4), a third guide rail (3-7), a Four guide rails (3-8); the third guide rail (3-7) is fixedly connected with the lower support (1-3), and the third slider (3-3) is relatively lower along the third guide rail (3-7) The support (1-3) slides up and down; the fourth guide rail (3-8) is fixedly connected with the upper support (1-1), and the fourth slider (3-4) faces up along the fourth guide rail (3-8) The support (1-1) slides up and down; One end of the first branch chain group (4), the second branch chain group (5), and the third branch chain group (6) is respectively connected to the fourth slider (3-4), the fifth slider (2-2 ), the third slide block (3-3) links to each other, and the other end links to each other with the moving platform (7). 2. A large working space three-translation parallel machine tool with two additional redundant slides according to claim 1, characterized in that the horizontal two-linkage linear module (3) also includes a first slider (3-1 ), the second slider (3-2), the first guide rail (3-5), the second guide rail (3-6), the push rod (3-9), the first connecting rod (3-10), the second Connecting rod (3-11), guide rail connector (3-12); The first guide rail (3-5) and the second guide rail (3-6) are all perpendicular to the worktable (8) and in the same vertical direction, the first guide rail (3-5) and the main column (1-2) Fixed connection, the lower end extends into the lower support (1-3); the second guide rail (3-6) is fixed on the guide rail connector (3-12), and the guide rail connector (3-12) and the upper support (1- 1) internal fixed connection; the first slider (3-1) and the second slider (3-2) are connected by a push rod (3-9); the first slider (3-1), the third slider ( 3-3) connected through the first connecting rod (3-10); the second sliding block (3-2) and the fourth sliding block (3-4) are connected through the second connecting rod (3-11). 3. A three-translational parallel machine tool with two redundant slides and large working space as claimed in claim 1, characterized in that the upper support (1-1), the lower support (1-3) and the main support The columns (1-2) form a C-shaped structure together, and the included angles between the upper support (1-1), the lower support (1-3) and the main column (1-2) in the working space are all 120° . 4. A large working space three-translational parallel machine tool with two additional redundant slides as claimed in claim 1, characterized in that the first branch chain group (4), the second branch chain group (5), the first branch chain group The three branch chain groups (6) have the same structure, and each group of branch chain groups is composed of two telescopic rods with the same structure; The two telescopic rods of the chain are always guaranteed to be parallel and equal in length when the machine tool is working, and each group of branch chains uses a servo motor to drive the two telescopic rods synchronously. 5. A three-translational parallel machine tool with two redundant slides and a large working space as claimed in claim 4, characterized in that the spherical joint is an improved Hooke hinge, through the traditional Hooke hinge A rotating pair is added to the base to replace the ordinary spherical joint, and the rotation range can reach -70°-70°. 6. A three-translational parallel machine tool with large working space and two redundant slides as claimed in claim 4, characterized in that each set of branch chains uses two servo motors to drive two telescopic rods respectively. 7. A three-translational parallel machine tool with two redundant slides and a large working space as claimed in claim 1, characterized in that the moving platform (7) is a pentahedral cavity structure, and the moving platform (7) and the second The two ends connected by a chain group (4) and the third branch chain group (6) intersect; the moving platform (7) and the first branch chain group (4) and the third branch chain group (6) Both ends are provided with convex table surfaces connected with the second branch chain group (4), and the two convex table surfaces are on the same plane. 8. A three-translational parallel machine tool with two redundant slides and a large working space as claimed in claim 7, characterized in that the end of the moving platform (7) connected to the first branch chain group (4) is provided with The first hinge hole (7-1) and the second hinge hole (7-2), the connection line of the hole center of the two holes is parallel to the connection line of the hole center of the two hinge holes on the fourth slider (3-4) and the hole distance is equal; The fifth hinge hole (7-5) and the sixth hinge hole (7-6) are arranged on the connecting end of the platform (7) and the third branch chain group (6). -3) The connecting lines of the hole centers of the upper two hinge holes are parallel and the hole spacing is equal; the two boss surfaces are respectively provided with the third hinge hole (7-3) and the fourth hinge hole (7-4), and the hole centers of the two holes are connected. The line is parallel to the line connecting the centers of the two hinge holes on the fifth slide block (2-2) and the hole spacing is equal. 9. A large working space three-translation parallel machine tool with two additional redundant slides as claimed in claim 1, characterized in that the end face of the first branch chain group (4) and the second The end faces of the four sliders (3-4) are kept parallel, the end face of the third branch chain group (6) is installed on the moving platform (7) and the end face of the third slider (3-3) is kept parallel, and the moving platform (7) is installed The end face of the second branch chain group (5) is kept parallel to the end face of the fifth sliding block (2-2).