Patent Application
20120006140
1. Field of the Invention
The present invention relates to a positioning platform and machine tool, and more particularly to a three-link toggle type positioning platform and machine tool.
2. Description of the Related Art
Machines establish the groundwork of manufacturing industry, due to all products are produced by machines. Furthermore, machine tools establish the groundwork of mechanical industry due to all manufacturing processes require machine tool. Therefore, with the development in industry and the advancement in technology, the machine tool industry will be progressed as well. Because bio-medical industry, telecommunication industry and optoelectronical industry ramp recently, current related products have developed to be more miniaturized, for example, micro optical components of high-speed signal transmission, micro-sensors, micro holes of optical fibers and photolithography. Accordingly, the micro/meso-scale manufacturing technology is the key point in the oncoming fabrication technology.
In industrial applications, precise machining is based on high precision positioning technology. Therefore, how to enhance precise positioning is an important index in promotion of industry. The difficulties of the precise positioning technology resulted from too many uncertain factors. Generally, the factors, which are not concerned in large-scale positioning, should be concerned in micro/nano scale positioning.
The wet etching, plasma etching, LIGA process, electron beam, ion beams and so on are used in nano-scaled machining, thus resulting in the development of micro-electro mechanical system (MEMS). Generally speaking, MEMS technology is applied in the fabrication of about 2D to 2.5D geometry, and the relative precision of fabrication is limited to about 10−1 to 10−2 millimeter. However, for many 3-D miniaturized products having requirements of higher precision and complex shape, the MEMS technology is not able to meet the requirements. Besides, another bottleneck of the MEMS technology is that it can not be applied to metallic material or other diversified materials. Furthermore, scanning tunneling microscope (STM) or atomic force microscope need to be used in nano-scaled fabrication, but the operation speed is lower and the technique is not mature yet.
Currently, machine tools of multi-axles are serial connected mechanism. This serial connected mechanism, which is similar to cantilever beams, has a larger working area, but it may deform or have displacement due to external loading or its weight. Therefore, only the conventional servo system of serial connected mechanism of higher precision may achieve the precision of sub-micron or even nano-meter scaled. However, the requirements of the related control technique are very strict, and the cost of the whole equipment is effectively increased. Besides, machines features the piezoelectric actuators also have the problems of smaller stroke and hysteresis.
Generally, platforms of meso-scale machine tools, such as milling machines, are being directly placed on ballscrews and then driven by motors to move. Intrinsic or extrinsic vibration will affect machine tools operation and precision at the same time. Refer to
To achieve the aforesaid object and industrial demands, the present invention discloses a three-link toggle type positioning platform which comprises a first platform, a first motor, a first ballscrew, a second platform, a first linkage, a second linkage and a third linkage. The first motor is disposed on the first platform. The first ballscrew is disposed on the first platform and coupled to the first motor, wherein the first motor is suitable for driving the first ballscrew to rotate. The second platform is disposed on the first platform, wherein the second platform is suitable for moving back and fourth alternately along a first predetermined path, wherein a first angle is existed between an extended direction of the first predetermined path and the first ballscrew. The second linkage is fixed on a first base, and is parallel to the first ballscrew and the second platform. The first linkage is disposed between the first ballscrew and the second linkage for connection, wherein a second angle is existed between the first ballscrew and the first linkage. The third linkage is disposed between the second linkage and the second platform, wherein a third angle is existed between the second linkage and the third linkage. Moreover, the first linkage, the second linkage and the third linkage are driven simultaneously by the rotation of the first ballscrew, such that the second platform is driven to move along the first predetermined path.
According to the present invention, the first angle of the three-link toggle type positioning platform is about 90°.
According to the present invention, the second angle of the three-link toggle type positioning platform is between about 0° to 90°.
According to the present invention, the third angle of the three-link toggle type positioning platform is between about 0° to 90°.
According to the present invention, the three-link toggle type positioning platform comprises two first linear bearings penetrate a first slide rail respectively, wherein the two first linear bearings are disposed on bilateral sides of the second platform and between the second platform and the first platform.
According to the present invention, the two first linear bearings of the three-link toggle type positioning platform are perpendicular to the first ballscrew.
According to the present invention, the two opposite ends of the first linkage of the three-link toggle type positioning platform are connected to the first ballscrew and the second linkage by a ball bearing and a bolt.
According to the present invention, the two opposite ends of the second linkage of the three-link toggle type positioning platform are connected to the first linkage and the first base by the ball bearing and the bolt.
The present invention further provides a three-link toggle type machine tool which comprises a first three-link toggle type positioning platform and a second three-link toggle type positioning platform. The first three-link toggle type positioning platform comprises a first platform, a first motor, a first ballscrew, a second platform, a first linkage, a second linkage, and a third linkage. The first motor is disposed on the first platform. The first ballscrew is disposed on the first platform and coupled to the first motor, wherein the first motor is suitable for driving the first ballscrew to rotate. The second platform is disposed on the first platform, wherein the second platform is suitable for moving back and fourth alternately along a first predetermined path, wherein a first angle is existed between an extended direction of the first predetermined path and the first ballscrew. The second linkage is fixed on a first base, wherein the second linkage is parallel to the first ballscrew and the second platform. The first linkage is disposed between the first ballscrew and the second linkage, wherein a second angle is existed between the first balscrew and the firstlinkage. The third linkage is disposed between the second linkage and the second platform, wherein a third angle is existed between the second linkage and the third linkage. Moreover, the first linkage, the second linkage and the third linkage are driven simultaneously by the rotation of the first ballscrew, such that the second platform is driven to move along the first predetermined path.
The second three-link toggle type positioning platform is disposed on the first three-link toggle type positioning platform, wherein the second three-link toggle type positioning platform comprises a second motor, a second ballscrew, a third platform, a fourth linkage, a fifth linkage, and a sixth linkage. The second motor is disposed on the second platform. The second ballscrew is disposed on the second platform and coupled to a second motor, wherein the second motor is suitable for driving the second ballscrew to rotate. The third platform is disposed on the second platform, wherein the third platform is suitable for moving back and fourth alternately along a second predetermined path, wherein a fourth angle is existed between an extended direction of the second predetermined path and the second ballscrew. The fourth linkage is disposed between the second ballscrew and the fifth linkage, wherein a fifth angle is existed between the second ballscrew and the fourth linkage. The fifth linkage is fixed on a second base, and is parallel to the second ballscrew and the third platform. The sixth linkage is disposed between the fifth linkage and the third platform, wherein a sixth angle is existed between the fifth linkage and the sixth linkage. Moreover, the fourth linkage, the fifth linkage and the sixth linkage are driven simultaneously by the rotation of the second ballscrew, such that the third platform is driven to move along the second predetermined path.
According to the present invention, the first angle of the three-link toggle type machine tool is about 90°.
According to the present invention, the second angle of the three-link toggle type machine tool is between about 0° to 90°.
According to the present invention, the third angle of the three-link toggle type machine tool is between about 0° to 90°.
According to the present invention, the fourth angle of the three-link toggle type machine tool is about 90°.
According to the present invention, the fifth angle of the three-link toggle type machine tool is between about 0° to 90°.
According to the present invention, the sixth angle of the three-link toggle type machine tool is between about 0° to 90°.
According to the present invention, the three-link toggle type machine tool further comprises two first linear bearings penetrate a first slide rail respectively, wherein the two first linear bearings are disposed on the bilateral sides of the second platform and between the first platform and the second platform.
According to the present invention, the three-link toggle type machine tool further comprises two second linear bearings penetrate a second slide rail respectively, wherein the two second linear bearings are disposed on the bilateral sides of the third platform and between the second platform and the third platform.
According to the present invention, the two first linear bearings are perpendicular to the first ballscrew.
According to the present invention, the two second linear bearings are perpendicular to the second ballscrew.
According to the present invention, the two opposite ends of the first linkage are connected to the first ballscrew and the second linkage by the ball bearing and the bolt.
According to the present invention, the two opposite ends of the second linkage are connected to the first linkage and the first base by ball the bearing and the bolt.
According to the present invention, the two opposite ends of the third linkage are connected to the second linkage and the second platform by the ball bearing and the bolt.
According to the present invention, the two opposite ends of the fourth linkage are connected to the second ballscrew and the fifth linkage by the ball bearing and the bolt.
According to the present invention, the two opposite ends of the sixth linkage are connected to the fifth linkage and the third platform by the ball bearing and the bolt.
The invention will be described according to the appended drawings in which:
The present invention provides a three-link toggle type positioning platform. For complete understanding of the present invention, the following description will describe in detail the method steps and the components. The present invention is not limited by the specified particulars of the radiation emitting semiconductor devices that are familiar to persons skilled in the art. In addition, well-known components or method steps are not described in detail so as to avoid any additional limitation. The preferable embodiments of the present invention are described in detail. In addition to the detailed descriptions, the present invention also can be applied to other embodiments. Therefore, the scope of the present invention is not limited, and is dependent on the following claims.
The present invention is based on a three-link theorem which is shown by a schematic diagram of a three-link structure in
4a×sin(θ2)−b×cos(θ3)=73.87+c (1)
b×sin(θ3)−4a×cos(θ2)=d (2)
The expression in Equation (1) can be converted as:
cos(θ3)=(4a×sin(θ2)−(c+73.87))/b
Then by applying Pythagorean Theorem, the above equation can be converted as:
b×sin(θ3)=(b2−(4a×sin(θ2)−c)2)1/2
By substituting the above equation into Equation (2), the following equation can be obtained.
(b2−(4a×sin(θ2)−c)2)0.5−4a×cos(θ2)−d=0 (3)
a×sin(θ2)+B×cos(θ4)=C (4)
a×cos(θ2)−B×cos(θ4)=D (5)
The expression in Equation (4) can be converted as:
sin(θ4)=(C−a×sin(θ2))/B
Then by applying Pythagorean Theorem, the above equation can be converted as:
B×cos(θ4)=(B2−(C−a×sin(θ2)2)1/2)
By substituting the above equation into Equation (5), the following equation can be obtained.
a×cos(θ2)−(B2−(C−a×sin(θ2)2)1/2)−(D+106.9445)=0 (6)
(22500−(200×sin(θ2)−(c+73.87))2)0.5−200×cos(θ2)−90=0 (7)
(50×cosd(θ2)+(14400−(100−50×sind(θ2))2)0.5)−(D+106.93)=0 (8)
Then utilizing a software called MATLAB to calculate Equation (7) and (8). Since the known angel θ2 is 90°, according to
Further,
The connecting structure for three-link linkage is to connect two opposite ends of the first linkage 34 with the first ballscrew 32 and the second linkage 36, and a second angle 24 is existed between the first ballscrew 32 and the fisrdt linkage 34. One opposite end of the second linkage 36 is fixed on the first base 48, wherein the first base 48 can support the second linkage 36. One end of the third linkage 38 connects to the second linkage 36 where near the first base 48. Moreover, one opposite end of the third linkage 38 connects the second platform, wherein a third angle 26 is existed between the second linkage 36 and the third linkage 38.
Due to one end of the second linkage 36 is connected to the first base 48 by a ball bearing and a bolt so as to function as a fixed axle, the second linkage 36 can only move left and right. When the first ballscrew 32 is driven by the first motor 46 to rotate, the first linkage 34, the second linkage 36 and the third linkage 38 are driven simultaneously by the first ballscrew 32 and cause the second angle 24 and the third angle 26 changing along with their movement. Since the second linkage 36 is fixed on the first base 48, the third linkage is non-movable. Moreover, in order to connect three linkages with the second base 14 and the first ballscrew 32 on a same horizontal plane, the three linkages have a supporting frame 50 which supports the three linkages having the same height as the second base 14 and the first ballscrew 32. In that way, the suspended three linkages can apply force properly.
Additionally, the second linkage 36 is connected to the first linkage 34 and the third linkage 38. When the first ballscrew 32 is driven by the first motor 46 to rotate, the three linkages are driven simultaneously by the rotation of the first ballscrew 32. The second angle 24 and the third angle 26 would change due to the movements of the three linkages, such that the second platform 14 is driven to move along the first predetermined path 54.
In the present invention, the first angle is existed between the extended directions of the second platform 14 and the first ballscrew 32, wherein the first angle is about 90°. The second angle is existed between the first linkage 34 and the third linkage 38, wherein the second angle is between about 0° to 90°. Further, the third angle is existed between the second linkage 36 and the third linkage 38, wherein the third angle is between about 0° to 90°.
The first ballscrew 32, the first linkage 34, the second linkage 36, the third linkage 38, the second platform 14 and the first base 48 are connected by the ball bearing and the bolt in order to decrease frictions therebetween and to decrease the load of the first motor 46.
The present invention further provides a three-link toggle type machine tool, as shown in
Please refer to
Referring to
The aforesaid third platform 70 can move back and fourth along the second predetermined path 94 with the help of a second linear bearing 88 and a second slide rail 86. The present invention comprises a second linear bearing 88 penetrates a second slide rail 86, wherein two opposite ends of the second slide rail 86 are fixed on repective supporting frames 50. The length of the second slide rail 86 is equal to that of the second predetermined path 94. The moving direction of the second linear bearing 88 and the second slide rail 86 is perpendicular to the second ballscrew 78 and the first predetermined path 54. Furthermore, the second linear bearing 88 and the second slide rail 86 are disposed between the second platform 14 and the third platform 70 and fixed on the bilateral sides of the third platform 70. Due to the second linear bearing 88 is a long-shaped cylindrical tube, which is made of iron or other materials, the third platform 70 can not being fixed on it. In the present embodiment, the second linear bearing 88 is fixed in a stable long-shaped quadrate tube in order to form a flat surface, which is disposed between the second platform 14 and the third platform 70 to avoid rotation. The second platform 14 may have a guide groove and the third platform 70 is suitable for moving along the guide groove. The guide groove has a cross-section of V-shape, U-shape, or other shapes. Besides, the present embodiment further comprises a ball bearing. The ball bearing is disposed on the second platform 14 and is between the second platform 14 and the third platform 70, and therefore the third platform 70 may move along the second predetermined path 94. In brief, the ball bearing may move along the guide groove (not shown).
The connecting structure for three-link linkage is to connect two opposite ends of the fourth linkage 80 with the second ballscrew 78 and the fifth linkage 82, wherein a fifth angle 74 is existed between the second ballscrew 78 and the fourth linkage 80. One opposite end of the fifth linkage 82 is fixed on the second base 92, wherein the second base 92 can support the fifth linkage 82. One end of the sixth linkage 84 connects to the fifth linkage 52 where near the second base 92. Moreover, one opposite end of the sixth linkage 84 connects the third platform 70, wherein a sixth angle 76 is existed between the fifth linkage 82 and the sixth linkage 84.
Due to one end of the fifth linkage 82 is connected to the second base 92 by a ball bearing and a bolt 52 so as to function as a fixed axle, the fifth linkage 82 can only move left and right. When the second ballscrew 78 is driven by the second motor 90 to rotate, the fourth linkage 80, the fifth linkage 82 and the sixth linkage 84 are driven simultaneously by the second ballscrew 78 and cause the fifth angle 74 and the sixth angle 76 changing along with their movement. Since the fifth linkage 82 is fixed on the second base 92, the third linkage is non-movable. Moreover, in order to connect three linkages with the third base 70 and the second ballscrew 78 on a same horizontal plane, the three linkages have a supporting frame 50 which supports the three linkages having the same height as the third base 70 and the second ballscrew 78. In that way, the suspended three linkages can apply force properly.
Additionally, the fifth linkage 82 is connected to the fourth linkage 80 and the sixth linkage 84. When the second ballscrew 78 is driven by the second motor 90 to rotate, the three linkages are driven simultaneously by the rotation of the second ballscrew 78. The fifth angle 74 and the sixth angle 76 would change due to the movements of the three linkages, such that the third platform 70 is driven to move along the second predetermined path 94.
In the present invention, the fourth angle is existed between the extended directions of the third platform 70 and the second ballscrew 78, wherein the fourth angle is about 90°. The fifth angle is existed between the fourth linkage 80 and the fifth linkage 82, wherein the fifth angle is between about 0° to 90°. Further, the sixth angle is existed between the fifth linkage 82 and the sixth linkage 84, wherein the sixth angle is between about 0° to 90°.
The second ballscrew 78, the fourth linkage 80, the fifth linkage 82, the sixth linkage 84, the third platform 70 and the second base 92 are connected by the ball bearing and the bolt 52 in order to decrease frictions therebetween and to decrease the load of the second motor 90.
Then, a LASER meter is being used to measure the amount of movement of the second platform 14 of the first three-link toggle type positioning platform 10. Placing a beam splitter in front of the LASER meter and a reflecting mirror on the second platform and then aligned for reflecting LASER beam. A measuring method is as follows. The beam splitter is used for splitting the LASER beam into a reference beam and a beam to be measured when it enters. The beam to be measured is then reflected back on the same path by the reflecting minor and meets the reference beam. After analyzed by a computer, the displacement of the second platform can be known.
The relationship between number of turns of motor and amount of movement of platform can be calculated according to the data shown in
The present invention provides a positioning platform with a toggle-type mechanism to improve its positioning precision. Moreover, the present invention provides a positioning platform with a three-link toggle type mechanism which makes it move faster than a single-link toggle type mechanism
The above-described embodiment of the present invention is intended to be illustrative only. Numerous alternative embodiments may be devised by persons skilled in the art without departing from the scope of the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 098114892 | May 2009 | TW | national |
