CN1093457C - Two parallel-rods virtual shaft multifunctional machine tool - Google Patents

Abstract

A double-parallel link virtual axis multifunctional machine tool, including a bed, a motion platform, a slider, a spindle box, a spindle, a chuck device, a servo motor, and a working platform. The working platform has a detachable column and its Servo motor, motor and grinding wheel. The machine tool also includes two parallel rod branch chains, rolling guide rails, T-shaped carriages, etc. This machine tool can be used for grinding drills with helical surface drill points, and can also be used as a multi-axis CNC drilling machine or Compared with the six-bar and three-bar parallel virtual axis machine tools, the machine tool involved in the present invention also has the advantages of high rigidity, high precision, and high weight/external force bearing ratio, and the mechanical structure is simpler, and the manufacturing cost is low. There is kinematic coupling, the working space is large, and it is easy to realize plane and straight line processing.

Description

Two-parallel link virtual axis multifunctional machine tool

The invention belongs to the technical field of machine tools, and in particular relates to a multifunctional numerically controlled machine tool with two parallel links and virtual axes.

The new structure of the parallel rod virtual axis (without the X, Y, Z axes of the traditional machine tool) machine tool based on the joint parallel Stewart platform is a new concept machine tool introduced in recent years. Taking the virtual axis machine tool with six parallel rods as an example, this machine tool uses six retractable rods to support and connect the moving platform (with the spindle head) and the fixed platform (with the workbench). Each rod is driven by its own servo motor and ball screw. The six rods can be stretched and extended to make the motion platform equipped with the spindle head move on six coordinate axes, thereby changing the relative spatial position of the spindle and the workpiece to meet the requirements of the tool movement trajectory during processing. For complex curved surfaces that require multiple positioning of the workpiece to be processed by traditional machine tools, this virtual axis machine tool can complete the machining in one operation. However, the six-bar virtual-axis machine tool based on the Stewart platform also has the following shortcomings: the geometric interference between the six bars makes the working space narrow, the real-time calculation of forward and reverse solutions is difficult, and the error compensation modeling is complicated, which increases the difficulty of programming control programs, especially The coupling of motion also requires high-precision moving parts and control systems, which are expensive and difficult to achieve industrialization at present. In order to solve the above-mentioned problems, scientific research institutions and companies in many countries are developing prototypes of three-parallel-link six-degree-of-freedom and three-parallel-link three-degree-of-freedom virtual axis machine tools, and have made some progress. For example, compared with the six-parallel-connected virtual-axis machine tool, the three-parallel-connected virtual-axis machine tool has a simpler mechanical structure, lower manufacturing cost, and increased work space. At the same time, the coupling of motion, the complexity of control calculation and error modeling are all somewhat different. improve. However, the disadvantages of the small working space of the parallel rod virtual axis machine tool, complex control calculation and difficult real-time control caused by the kinematic coupling between the rods have not been fundamentally solved.

Spiral drill point is a very popular drill type in the international metal cutting tool market. Because the chisel edge is S-shaped, it has the characteristics of good centering, stable cutting, small drilling axial force, strong chip removal ability and good drilling quality. The sharpening of helical drill points is realized abroad by automatic drill point sharpening machine tools, CNC drill point sharpening machines, and some universal CNC tool grinders. The automatic drill point sharpening machine uses the motor to drive the spindle holding the drill bit to rotate, and the other two movements are driven by the motor through the cam structure to drive the grinding wheel or the spindle frame holding the drill bit to achieve sharpening of the helical drill point; CNC drill point The grinding machine uses the numerical control program to realize the sharpening of the helical drill tip by controlling three stepping motors (or servo motors) related to the three movements for three-axis linkage.

The purpose of the present invention is to introduce a kind of simple structure, easy real-time control, high performance-price ratio, can grind the drill bit with helical surface drill point, can be used as multi-axis numerical control drilling machine or milling machine, can realize industrialization completely Parallel link virtual axis multifunction machine tool.

The dual-parallel-connection-rod virtual axis multifunctional machine tool involved in the present invention includes a bed, a two-parallel-connection rod branch chain, a motion platform, a rolling guide rail, a slider, a T-shaped carriage, a servo motor, a spindle box, a main shaft, a drill bit (or a milling cutter) ) Chuck device, working platform with detachable column and servo motor, motor and grinding wheel on the working platform. There are two linear rolling guide rails on the upper part of the bed, and a T-shaped carriage is arranged on the linear rolling guide rails, and a ball screw connecting the servo motor with the T-shaped carriage is installed between the linear rolling guide rails; the T-shaped carriage Two linear motors driving two sliders are installed on the board, and the two parallel link branch chains connect the motion platform with the two sliders through a ball joint. Each rod branch chain is composed of four parallel fixed-length rods, or three parallel fixed-length rods can be used to form each rod branch chain; the motion platform is sequentially equipped with a servo motor and a headstock with a main shaft 1. The chuck device equipped with a drill bit (or milling cutter) is connected to the main shaft; the linear motor drives two sliders to change the distance between the two sliders, so as to push the motion platform in XYZ Cartesian coordinates by means of two parallel rod branch chains Carry out arc curve translation in the YZ plane of the system, and then realize the required curve motion of the drill bit (or milling cutter); There is no Y, Z axis of the traditional machine tool, but the direction and speed of the two sliders are controlled by the drive of the linear motor, so that the main shaft can realize the movement of the Y axis or the Z axis alone.

Compared with the six-parallel-connected-rod virtual axis and the three-parallel-connected-rod virtual axis with telescopic rods, the double-parallel-connected branch chain of the present invention is composed of parallel and fixed-length rods, so simple rods can be used, and there is no built-in heat source to avoid affected by heat. Therefore, in addition to the advantages of high rigidity of the parallel-bar virtual axis machine tool, rapid space curve processing capability, and high weight/external force bearing ratio, the present invention has a simpler mechanical structure and higher precision than six-bar and three-bar parallel virtual-axis machine tools. High, low manufacturing cost, and at the same time, there is no coupling of motion, closed forward and reverse solution control calculations can be performed, and real-time control is easy. In addition, the present invention also has some characteristics of ordinary machine tools, such as large working space and easy realization of plane and straight line processing. Especially when grinding the helical drill point, the present invention can be realized only by 2-axis linkage, while the traditional drill point sharpening machine needs 3-axis linkage. Therefore, the present invention has broad application prospects.

The present invention will be further described below in conjunction with drawings and embodiments.

Fig. 1 is a structural representation of the present invention;

Fig. 2 is the top view of Fig. 1;

FIG. 3 is a side view of FIG. 1 .

Example 1:

As shown in Figures 1, 2, and 3, the key for the drill point sharpening machine to sharpen the helical drill tip is to realize the three movements required for sharpening the helical drill tip at the same time. 1 in the figure is the bed. Before sharpening, the drill bit 4 is clamped on the headstock 14 on which the main shaft is installed through the chuck device 5. The servo motor 23 drives the ball screw in the dust cover 18 to rotate, and then passes through the screw nut seat. Drive the T-shaped carriage 16 to move longitudinally (X direction) along the linear rolling guide rail 17 and the linear rolling guide rail 19, thereby realizing the adjustment of the longitudinal (X direction) positions of the drill bit 4 and the emery wheel 15. Two linear motors are installed on the T-type carriage 16 to respectively drive the slider 10 and the slider 12 to make a horizontal (Y direction) linear reciprocating motion on the linear guide rail on the T-type carriage. The motion platform 6 is pushed to make a horizontal (Y direction) linear motion, thereby realizing the adjustment of the lateral (Y direction) positions of the drill bit 4 and the grinding wheel 15 . Detachable column 22 is housed on the working platform 2, and the servomotor 21 on the column can drive motor 3 to rotate left and right along M direction, thereby can adjust the axis of the emery wheel 15 that is installed on the motor 3 and the angle of drill bit 4 axis, namely determine the angle of the drill bit 4 axis. Sharpen the tip angle of the drill bit 4. When sharpening the drill point, the servo motor 11 drives the drill bit 4 to rotate by the main shaft in the headstock 14, while the slide block 12 does not move, and the linear motor drives the slide block 10 to translate along the A direction (or the slide block 10 does not move, and the linear motor drives The slider 12 translates along the B direction), and the motion platform 6 is pushed by two parallel rod branch chains 8 and 13 to generate a curved translation motion in the vertical plane (YZ plane), thereby driving the main shaft in the headstock to sharpen the helical drill point the other two movements. Servo motor 11 drives the main shaft to rotate from 0 ° to 180 ° to realize sharpening of a flank of the drill bit, and then slider 10 (or slider 12) returns to the initial position; servo motor 11 drives the main shaft to rotate from 180 ° to 360 °, and at the same time The slider 10 then translates along the A direction (or the slider 12 translates along the B direction) so as to realize the sharpening of the other flank of the drill bit. After such a cycle, the sharpening of the helicoid drill point is finally realized. Meanwhile, the servo motor 20 drives the movement of the working platform 2 in the vertical direction (Z direction) to adjust the grinding amount of the flank of the sharpened drill point.

Example 2:

As shown in Figures 1, 2, and 3, the detachable column 22 and its servo motor 21, motor 3 and emery wheel 15 are removed, and the present invention becomes a two-parallel-connection bar virtual axis drilling machine. 1 in the figure is the bed. Before drilling, the workpiece to be drilled is clamped on the work platform 2; the drill bit 4 is clamped on the spindle headstock 14 by the chuck device 5, and the servo motor 23 drives the dustproof The ball screw in the cover 18 rotates, and then drives the T-shaped carriage 16 to move longitudinally (X direction) along the linear rolling guide rail 17 and linear rolling guide rail 19 through the screw nut seat, so as to realize the longitudinal (X direction) position of the drill bit 4 and the workpiece. adjustment. Two linear motors are installed on the T-type carriage 16 to respectively drive the slider 10 and the slider 12 to make a horizontal (Y direction) linear reciprocating motion on the linear guide rail on the T-type carriage. Push the motion platform 6 to make a horizontal (Y direction) linear motion, and then realize the adjustment of the position of the drill bit 4 and the workpiece in the lateral direction (Y direction). During drilling, the servo motor 11 drives the drill bit 4 to rotate itself through the main shaft in the headstock 14, and at the same time, the two linear motors respectively drive the slider 10 and the slider 12 to move at the same speed along the A and B directions at the same time. The branch chains 8 and 13 push the motion platform 6 to generate the drilling feed motion in the vertical direction (Z direction), thereby completing the drilling of the workpiece; , and the servo motor 20 drives the movement of the working platform 2 in the vertical direction (Z direction) to realize the drilling feed movement, and also complete the drilling of the workpiece.

Example 3:

As shown in Figures 1, 2, and 3, the detachable column 22 and its servo motor 21, motor 3 and emery wheel 15 are removed, and the drill bit 4 is changed into an end mill or a ball end mill, and the present invention becomes A virtual axis milling machine with two parallel bars. 1 in Fig. 1 is the bed. Before milling, the workpiece to be milled is clamped on the work platform 2; the milling cutter is clamped on the headstock 14 on which the main shaft is installed through the chuck device 5, and the servo motor 23 drives the dustproof The ball screw in the cover 18 rotates, and then drives the T-shaped carriage 16 to move longitudinally (X direction) along the linear rolling guide rail 17 and linear rolling guide rail 19 through the screw nut seat, so as to realize the longitudinal (X direction) position of the milling cutter and the workpiece. adjustment. Two linear motors are installed on the T-type carriage 16 to respectively drive the slider 10 and the slider 12 to make a horizontal (Y direction) linear reciprocating motion on the linear guide rail on the T-type carriage and change the distance between the slider 10 and the slider 12. distance, so that the two parallel rod branch chains 8 and 13 are used to push the motion platform 6 to do horizontal (Y direction) and vertical (Z direction) translational motions, thereby realizing the horizontal (Y direction) and vertical (Z direction) direction (Z direction) between the milling cutter and the workpiece. ) position adjustment. During milling, the servo motor 11 drives the milling cutter to rotate through the main shaft in the headstock 14, and at the same time, the servo motor 23 drives the ball screw in the dust cover 18 to rotate, and then drives the T-shaped carriage 16 to roll along the guide rail in a straight line through the screw nut seat 17 and the linear rolling guide rail 19 move longitudinally (X direction), so the sliders 10 and 12 are driven, and the motion platform 6 is pushed through two parallel rod branch chains 8 and 13 to realize the movement of the milling cutter along the longitudinal direction (X direction) of the workpiece, while Two linear motors respectively drive the slider 10 and the slider 12 to move at the same speed along the A direction (or the B direction) at the same time, and push the motion platform 6 with the help of two parallel rod branch chains 8 and 13 to realize the milling cutter moving along the transverse direction of the workpiece (Y direction). ), so as to complete the milling of the workpiece in the horizontal plane (XY plane); in addition, during the above operation, if the two linear motors respectively drive the slider 10 and the slider 12 at different speeds along the A direction (or B direction) Simultaneous movement, or driving slider 10 (or slider 12) moves and slider 12 (or driving slider 10) does not move, then changes the distance between slider 10 and slider 12, by means of two parallel rods The chains 8 and 13 push the motion platform 6 to realize the curved movement of the milling cutter in the vertical plane (YZ plane), and then the curved surface milling of the workpiece in the space (XYZ coordinate system space) can be completed.

Claims (6)

1. A two-parallel linkage virtual axis multifunctional machine tool, including a bed, a motion platform, a slider, a spindle box, a spindle, a chuck device, a servo motor, a working platform, and a detachable column and its The servo motor, motor and grinding wheel on the machine tool are characterized in that the machine tool also includes two parallel rod branch chains, rolling guide rails, and T-shaped carriages. T-type carriage, a ball screw connecting the servo motor with the T-type carriage is installed between the linear rolling guide rails, and the T-type carriage is equipped with two linear motors driving two sliders, and the two parallel rod branch chains pass through The ball joint connects the motion platform with the two sliders, and the motion platform is sequentially equipped with a servo motor, a headstock with a main shaft, and a collet device connected with the main shaft. 2. The dual-parallel-connected-rod virtual-axis multifunctional machine tool according to claim 1, characterized in that each branch chain of said two-parallel-connected rod branch chain is four parallel fixed-length rods. 3. The dual-parallel-connected-rod virtual-axis multifunction machine tool according to claim 1, wherein each branch chain of said two-parallel-connected rod branch chain is three parallel and fixed-length rods. 4. The double-parallel-connected-rod virtual axis multifunctional machine tool according to claim 1, wherein when the machine tool is a double-parallel-connected rod virtual-axis drilling machine, the detachable column and the servo motor, motor and grinding wheel on it are unloaded. Go, load the drill on the chuck unit. 5. The double-parallel-link virtual axis multi-function machine tool according to claim 1, wherein when the machine tool is a double-parallel-link virtual-axis milling machine, the detachable column and the servo motor, motor and grinding wheel on it are unloaded. Go, load the end mill on the collet assembly. 6. The multifunctional machine tool with two parallel rods and virtual axes as claimed in claim 1, wherein when the machine tool is a milling machine with two parallel rods and virtual axes, the detachable column and the servo motor, motor and grinding wheel on it are unloaded. Go, install the ball end mill on the collet unit.

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