CN105666468B - A kind of big swing angle planer-type five-axle linkage series-parallel machine tool - Google Patents

Abstract

The invention belongs to the technical field of mechanical manufacturing, and specifically relates to a gantry-type five-axis linkage hybrid machine tool with a large swing angle, which solves the problem of the limitation of the tool swing angle of the traditional numerical control machine tool and the existing parallel/hybrid machine tool and the problem of processing slender overall structures. There are disadvantages such as poor flexibility, low rigidity and low precision in parts. It includes a long straight guide rail and a parallel processing module; the parallel processing module forms a space parallel closed-loop mechanism; the parallel processing module realizes the two-dimensional movement of the moving platform in the XZ plane and the two-dimensional movement of the rotating shaft in the upper plane of the moving platform through four input drives. Rotation, the parallel processing module is added with an input drive in the Y- axis direction to make the parallel processing module slide along the Y- axis direction, so that the moving platform of the parallel processing module realizes five-axis linkage movement. The invention has the advantages of simple structure, large working space, good flexibility of the moving platform, high rigidity precision, small change of driving load in the Y- axis direction, good dynamic performance, strong reconfigurability and high modularization degree.

Description

A large swing angle gantry type five-axis linkage hybrid machine tool

technical field

The invention belongs to the technical field of mechanical manufacturing, and specifically relates to a large-swing angle gantry-type five-axis linkage hybrid machine tool, which is a multi-axis linkage that can be applied to the field of numerical control machining and can realize precision machining of slender integral structural parts with large swing angles device.

Background technique

The parallel mechanism is a closed-loop mechanism composed of multiple branch chains. Compared with the traditional series mechanism, the parallel mechanism has the following advantages: As a kind of manufacturing equipment with the parallel mechanism as the mechanical body, the parallel machine tool appeared in the late 1990s. With the deepening of theoretical research on parallel mechanisms and the continuous development of numerical control technology, automation technology and computer technology, parallel machine tools have gradually become an important new manufacturing equipment and are used in modern manufacturing. Compared with traditional tandem machine tools, parallel machine tools have a higher stiffness-to-weight ratio, faster response speed, and higher machining accuracy. Therefore, it is more suitable for processing under high speed, precision and heavy load. Moreover, it has a high degree of modularization, easy reconfiguration, and good flexibility, which makes it easier to reduce processing costs. However, the parallel machine tool has the disadvantages of relatively small working space and limited processing range, which limits its application field. In view of the dual relationship between the parallel mechanism and the series mechanism in configuration, people thought of combining the parallel mechanism and the series mechanism, thus proposing the configuration of the hybrid mechanism, and using the hybrid mechanism as the mechanical body of the CNC machine tool to produce a new type of hybrid online machine. The hybrid machine tool combines the advantages of parallel and serial machine tools, and at the same time avoids the respective shortcomings of parallel and serial configurations, and is more practical in modern manufacturing. Because of this, this kind of five-axis linkage hybrid machining center based on parallel mechanism or containing parallel modules has received extensive attention and research, and has gradually become the development trend of high-speed, high-precision, and high-flexibility CNC machine tools.

In recent years, more and more attention has been paid to the overall design principles of slender overall structural parts such as aircraft fuselage, wings, ribs, train carriages, etc., which are used in aerospace, railway transportation, national defense and military industries. The basic concept of the overall design is to remove metal from an integral blank to obtain an integral structural part with superior performance. Its advantage not only shortens the processing and assembly cycle and logistics chain, but also reduces the weight of structural parts. Most of these slender overall structural parts have a high part removal rate, and are complex in shape, porous, and thin in wall thickness. In order to complete this complex machining, a five-axis linkage CNC machine tool must be used, and the performance requirements of the machine tool are relatively high. Due to the disadvantages of traditional CNC machine tools in the processing of complex and slender integral structural parts, it is an urgent task to find new and efficient processing machine tools. In view of the advantages of hybrid machine tools for high-speed, high-precision, and heavy-duty processing, the development of new hybrid machine tools will become an effective solution.

In the major scientific and technological project of "high-end CNC machine tools and basic manufacturing equipment" implemented in early 2009, the functional accessories of the parallel mechanism and the five-axis linkage machining center equipped with such functional components were taken as one of the subjects. It can be seen that the parallel module is the key to the development of this type of equipment. From the perspective of processing flexibility and processing efficiency, the parallel module should have a high degree of rotation flexibility, and the rotation ability of the moving platform can reach 90° is the best (in order to achieve vertical and horizontal conversion, five-sided processing), and this is exactly the traditional The limitation of the parallel mechanism lies in that the rotation capability of the most influential Sprint Z3 parallel spindle head is only 40° (it cannot realize five-sided machining in the strict sense). It can be seen that breaking through the limitation of the swing angle of the traditional parallel mechanism under the premise of ensuring high stiffness is a bottleneck problem that needs to be overcome urgently in the research and development process of this type of equipment.

Aiming at the disadvantages of traditional CNC machine tools and existing parallel/hybrid machine tools in processing slender overall structural parts, the present invention proposes a modular four-degree-of-freedom parallel mechanism as the main body supplemented by long straight guide rails to realize five-axis linkage processing hybrid machine tool. This machine tool is applied to the processing of slender overall structural parts with simple structure, large working space, good flexibility of moving platform, high rigidity precision, small change of driving load in Y- axis direction, good dynamic performance, strong reconfigurability and modularization degree Advanced advantages. It can realize five-axis simultaneous machining of complex and slender integral structural parts.

Contents of the invention

The invention belongs to the technical field of mechanical manufacturing, and specifically relates to a gantry-type five-axis linkage hybrid machine tool with a large swing angle, which solves the problem of the limitation of the tool swing angle of the traditional numerical control machine tool and the existing parallel/hybrid machine tool and the problem of processing slender overall structures. There are disadvantages such as poor flexibility, low rigidity and low precision in parts.

The present invention adopts following technical scheme to realize:

A large-swing angle gantry-type five-axis linkage hybrid machine tool, including: a long straight guide rail arranged along the Y- axis direction, a parallel processing module, a fixture and a workbench; the parallel processing module includes a basic platform, a moving platform, tools and Connect the first branch chain and the second branch chain between the basic platform and the moving platform, and each part forms a space parallel closed-loop mechanism; the parallel processing module realizes the two-dimensional movement of the moving platform in the XZ plane through four input drives With the two-dimensional rotation of the rotary shaft of the moving platform in its upper plane, the parallel processing module is installed on the long straight guide rail set along the Y- axis direction, and an input drive is added in the Y- axis direction to make the parallel processing module slide along the Y- axis direction , so that the moving platform of the parallel processing module realizes five-axis linkage movement.

The first branch chain of the parallel processing module is a (3-RPR)-R type mixed kinematic branch chain, P represents a moving pair, R represents a rotating pair, and the first branch chain includes a planar parallel closed-loop mechanism 3-RPR, a planar Parallel closed-loop mechanism 3-RPR includes: basic platform, upper link I, lower link I, upper link II, lower link II, upper link III, lower link III, connecting platform and each kinematic pair, the The kinematic pair includes: the revolving pair R connecting the base platform and the upper link I, the moving pair P connecting the upper link I and the lower link I, and the revolving pair connecting the lower link I and the connecting platform R, the revolving pair R connecting the base platform and the upper link II, the moving pair P connecting the upper link II and the lower link II, the revolving pair R connecting the lower link II and the connecting platform, connecting The revolving pair R between the base platform and the upper link III, the moving pair P connecting the upper link III and the lower link III, the revolving pair R connecting the lower link III and the connecting platform; the first branch chain It also includes the rotary pair R between the connecting platform and the moving platform; the axes of all the rotating pairs R of the planar parallel closed-loop mechanism are parallel to each other and perpendicular to the axes of the rotating pair R between the connecting platform and the moving platform; where the connecting rod I The movement pair P between the lower link I, the movement pair P connected between the upper link II and the lower link II, and the movement pair P connected between the upper link III and the lower link III are input drive movement pairs , the planar parallel closed-loop mechanism realizes the two-dimensional movement of the connecting platform in the XZ plane and the one-dimensional rotation of the connecting platform axis along the Y- axis direction.

The second branch chain of the parallel processing module is an RRPS type motion branch chain, S represents a spherical joint, and the second branch chain includes: upper link IV, connecting frame, lower link IV and each kinematic pair, the described kinematic The pairs include: the revolving pair R connecting the base platform and the connecting frame, the revolving pair R connecting the connecting frame and the upper link IV, the moving pair P connecting the upper link IV and the lower link IV, and connecting the lower link IV The spherical joint pair S between the connecting rod IV and the moving platform; the moving pair P connecting the upper connecting rod IV and the lower connecting rod IV is an input-driven kinematic pair, connecting the rotating pair R and the connection between the basic platform and the connecting frame The axes of the rotating pairs R between the connecting frame and the upper link IV are perpendicular to each other, and the two rotating pairs R can be replaced by a Hooke hinge U.

The axis of the revolving pair R connecting the base platform and the connecting frame in the second branch chain is coaxial with the axis of the revolving pair R connecting the base platform and the upper link II in the first branch chain.

The parallel processing module is connected to the long straight guide rail through the moving pair P between the basic platform and the long straight guide rail. The moving pair P is an input-driven motion pair to realize the Y- axis movement of the parallel processing module.

In the first branch chain of the parallel processing module, the distance from the center of the rotating pair R between the basic platform and the upper connecting rod I to the center of the rotating pair R between the basic platform and the upper connecting rod II is the same as that between the basic platform and the upper connecting rod The distance from the center of the rotary joint R between III to the center of the rotary joint R between the base platform and the upper link II is not equal.

According to the relationship between mechanism constraints and motion, it can be deduced that in the parallel processing module, there is a structural constraint that the moving platform moves along the Y axis relative to the base platform, so it is impossible to realize the movement of the moving platform along the Y axis relative to the base platform, and there is a parallel movement of the moving platform along the Y axis. Due to the constraint force couple in the direction of the tool axis, the rotation in the direction parallel to the tool axis cannot be realized. The rotation ability of the moving platform along the hinge shaft of the first branch chain and the moving platform can reach 115° (–25°~90°), and the rotation ability along the direction parallel to the Y axis can reach 100° (-50°~50°). Solved the problem of limited swing angle of the parallel mechanism, installed the parallel processing module on the long straight guide rail along the Y- axis direction, and added an input drive in the Y- axis direction to make the parallel processing module slide along the Y- axis direction, and realized parallel processing The large-range movement of the module in the Y- axis direction solves the problem of the small working space of the traditional parallel mechanism, thereby realizing the large-scale swing angle and large-scale five-axis linkage movement of the moving platform of the parallel processing module.

The invention combines the advantages of traditional serial machine tools and parallel machine tools, and has the advantages of simple structure, large working space, good flexibility of the moving platform, high rigidity precision, small change of driving load in the Y- axis direction, good dynamic performance, strong reconfigurability and modularity. Advantages of high degree of transformation. It can realize five-axis simultaneous machining of complex and slender integral structural parts.

Description of drawings

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

FIG. 2 is a structural schematic diagram of a parallel processing module in the machine tool structure shown in FIG. 1 .

FIG. 3 is a schematic structural diagram of the first branch chain in the parallel processing module shown in FIG. 2 .

FIG. 4 is a schematic structural diagram of the second branch in the parallel processing module shown in FIG. 2 .

In the figure: 1. Long straight guide rail, 2. Parallel processing module, 21. Basic platform, 22. Moving platform, 23. Tool, 24. First branch chain, 241. Upper link , 242, lower connecting rod , 243, upper link , 244, lower link , 245, upper link , 246, lower connecting rod , 247, connecting platform, 25, second branch chain, 251, upper link , 252, connecting frame, 253, lower link , 3. Fixture, 4. Workbench, 5. Sample workpiece.

Detailed ways

The specific embodiment of the present invention will be further described in conjunction with the accompanying drawings.

As shown in Figures 1 to 4, a large-swing angle gantry-type five-axis linkage hybrid machine tool includes: a long straight guide rail 1 along the Y- axis direction, a parallel processing module 2, a fixture 3, a workbench 4, and an example workpiece 5; Parallel processing module 2 comprises basic platform 21, moving platform 22, cutting tool 23 and the first branch chain 24, the second branch chain 25 connecting between basic platform 21 and moving platform 22, each part forms a space parallel closed-loop mechanism; The parallel processing module 2 realizes the two-dimensional movement of the moving platform 22 in the XZ plane and the two-dimensional rotation of the rotating shaft in the upper plane of the moving platform 22 through four input drives, and the parallel processing module 2 is installed on the long axis along the Y axis direction On the straight guide rail 1, and add an input drive in the Y- axis direction to slide the parallel processing module 2 along the Y -axis direction, so that the moving platform 22 of the parallel processing module 2 can realize five-axis linkage movement.

As shown in Figures 2 and 3, the first branch chain 24 of the parallel processing module 2 is a (3-RPR)-R type mixed kinematic branch chain (P represents a moving pair, and R represents a rotating pair), which includes a plane The parallel closed-loop mechanism 3-RPR and the rotary pair R between the connecting platform 247 and the moving platform 22, this planar parallel closed-loop mechanism can realize the two-dimensional movement of the connecting platform 247 on the XZ plane and the one-dimensional movement of the connecting platform 247 axis along the Y- axis direction Rotation; planar parallel closed-loop mechanism 3-RPR includes: base platform 21, upper link I241, lower link I 242, upper link II 243, lower link II 244, upper link III 245, lower link III 246, Connect the platform 247 and each kinematic pair, and the kinematic pair includes: the rotary pair R connected between the base platform 21 and the upper link I 241, the mobile pair P connected between the upper link I 241 and the lower link I 242 , connecting the revolving pair R between the lower connecting rod I 242 and the connecting platform 247, connecting the revolving pair R between the base platform 21 and the upper connecting rod II 243, connecting the movement between the upper connecting rod II 243 and the lower connecting rod II244 P, connecting the rotating pair R between the lower connecting rod II 244 and the connecting platform 247, connecting the rotating pair R between the base platform 21 and the upper connecting rod III 245, connecting the upper connecting rod III 245 and the lower connecting rod III 246 Between the moving pair P, connecting the rotating pair R between the lower link III 246 and the connecting platform 247; The axes are perpendicular to each other; the mobile pair P between the upper link I 241 and the lower link I 242 is connected, the mobile pair P between the upper link II 243 and the lower link II 244 is connected, and the upper link III 245 is connected The moving pair P between the lower link III 246 is an input driven moving pair.

As shown in Figure 4, the second branch chain 25 of the parallel processing module 2 is a UPS type motion branch chain (U represents a Hooke hinge, S represents a ball joint) and can also be regarded as a RRPS type motion branch chain, in which two The axes of the rotating pair R are perpendicular to each other. This branch chain 25 includes: an upper link IV 251, a connecting frame 252, a lower link IV 253 and each kinematic pair. The revolving pair R, the revolving pair R connecting the connecting frame 252 and the upper link IV 251, the moving pair P connecting the upper link IV 251 and the lower link IV 253, connecting the lower link IV 253 and the moving platform 22 between the ball joint pair S; wherein the mobile pair P connected between the upper link IV 251 and the lower link IV 253 is an input drive motion pair.

As shown in Figure 1, the parallel processing module 2 is connected to the long straight guide rail 1 through the moving pair P between the basic platform 21 and the long straight guide rail 1. The moving pair P is an input drive motion pair, realizing the parallel processing module 2 Y axis movement.

As shown in Figure 2, in the first branch chain 24 of the parallel processing module 2, the center of the rotating pair R between the base platform 21 and the upper connecting rod I 241 is to the center of the rotating pair R between the basic platform 21 and the upper connecting rod II 243 The distance between the base platform 21 and the center of the revolving joint R between the upper link III 245 and the center of the revolving joint R between the base platform 21 and the upper link II 243 is not equal, which is to overcome a singular position. The axis of the revolving pair R connecting the base platform 21 and the connecting frame 252 in the second branch chain 25 is coaxial with the axis of the revolving pair R connecting the base platform 21 and the upper link II 243 in the first branch chain 24 .

Claims (6)

1. A large swing angle gantry type five-axis linkage mixed machine tool is characterized in that it includes: a long straight guide rail, a parallel processing module, a fixture and a workbench arranged along the Y -axis direction; the parallel processing module includes a base platform, The first branch chain, the second branch chain and the connection platform between the moving platform, the tool and the connecting base platform and the moving platform, each part forms a space parallel closed-loop mechanism, and the first branch chain of the parallel processing module is (3 -RPR)-R type mixed motion branch chain, the first branch chain includes the rotating pair R between the connection platform and the moving platform, the second branch chain of the parallel processing module is the RRPS type motion branch chain; the parallel processing module The two-dimensional movement of the moving platform in the XZ plane and the two-dimensional rotation of the rotating shaft of the moving platform in the upper plane are realized through four input drives. The direction is added with an input drive that makes the parallel processing module slide along the Y- axis direction, so that the moving platform of the parallel processing module realizes five-axis linkage motion. 2. The large swing angle gantry-type five-axis linkage hybrid machine tool according to claim 1, characterized in that: the first branch chain includes a planar parallel closed-loop mechanism 3-RPR, and the planar parallel closed-loop mechanism 3-RPR includes: The basic platform, the upper link I, the lower link I, the upper link II, the lower link II, the upper link III, the lower link III, the connecting platform and each kinematic pair. The kinematic pair includes: connecting the basic platform The rotary pair R between the upper link I and the upper link I, the mobile pair P connected between the upper link I and the lower link I, the rotary pair R connected between the lower link I and the connecting platform, and the connecting base platform and the upper link The rotating pair R between the rods II, the moving pair P connecting the upper connecting rod II and the lower connecting rod II, the rotating pair R connecting the lower connecting rod II and the connecting platform, and connecting the base platform and the upper connecting rod III The rotating pair R between the connecting rod III and the lower connecting rod III, the moving pair P connecting the lower connecting rod III and the connecting platform; the first branch chain also includes the connecting platform and the moving platform The revolving pair R between them; the axes of all revolving pairs R in the planar parallel closed-loop mechanism are parallel to each other and perpendicular to the axes of the revolving pair R between the connecting platform and the moving platform; among them, the connection between the upper link I and the lower link I The moving pair P, the moving pair P connected between the upper link II and the lower link II, and the moving pair P connected between the upper link III and the lower link III are input-driven kinematic pairs, and the planar parallel closed-loop mechanism 3-RPR Realize the two-dimensional movement of the connecting platform on the XZ plane and the one-dimensional rotation of the connecting platform axis along the Y- axis direction. 3. The large swing angle gantry type five-axis linkage hybrid machine tool as claimed in claim 1, characterized in that: the second branch chain includes: upper link IV, connecting frame, lower link IV and each kinematic pair , the kinematic pair includes: connecting the rotating pair R between the base platform and the connecting frame, connecting the rotating pair R between the connecting frame and the upper link IV, connecting the movement between the upper link IV and the lower link IV The pair P and the ball joint pair S connecting the lower connecting rod IV and the moving platform; the moving pair P connecting the upper connecting rod IV and the lower connecting rod IV is an input drive kinematic pair, connecting the basic platform and the connecting frame The revolving pair R and the axis of the revolving pair R between the connecting frame and the upper link IV are perpendicular to each other, and the two revolving pairs R can be replaced by a Hooke hinge U. 4. The large-swing-angle gantry-type five-axis linkage hybrid machine tool as claimed in claim 1, 2 or 3, characterized in that: in the second branch chain, the revolving pair R connecting the base platform and the connecting frame The axis is coaxial with the axis of the revolving pair R connecting the basic platform and the upper link II in the first branch chain. 5. The large-swing angle gantry-type five-axis linkage hybrid machine tool as claimed in claim 4, characterized in that: the parallel processing module is connected to the long straight guide rail through the moving pair P between the basic platform and the long straight guide rail, The moving pair P is an input-driven motion pair, which realizes the Y- axis movement of the parallel processing module. 6. The large swing angle gantry type five-axis linkage hybrid machine tool as claimed in claim 5, characterized in that: in the first branch chain of the parallel processing module, the rotating pair R between the basic platform and the upper link I The distance from the center to the R center of the rotary joint R between the base platform and the upper link II and the distance from the R center of the rotary joint R between the base platform and the upper link III to the R center of the rotary joint R between the base platform and the upper link II not equal.