High-rigidity macro-micro two-stage lifting platform

Abstract

The invention discloses a high-rigidity macro-micro two-stage lifting platform, and relates to the field of precision machining and precision detection, and the high-rigidity macro-micro two-stage lifting platform is characterized in that a lower-layer moving table is located at the lower part and is fixedly connected with a first group of crossed roller guide rail modules through a lower-layer sliding plate; the upper-layer moving table is positioned at the upper part and is fixedly connected with the first group of crossed roller guide rail modules through an upper-layer sliding plate; the linear motor module comprises a linear motor magnetic track and a linear motor coil, the linear motor magnetic track is fixedly connected with the base, the linear motor coil is fixedly connected with the lower-layer sliding plate, and the lower-layer moving table is driven to achieve millimeter-level stroke lifting; the piezoelectric ceramic module is fixedly installed on the side face of the lower-layer sliding plate, the extension end of the piezoelectric ceramic module makes contact with the side face of the upper-layer sliding plate, and the piezoelectric ceramic module drives the upper-layer moving table to achieve lifting of a micron-order stroke. According to the invention, a macro-micro two-stage lifting mechanism is adopted, so that the lifting mechanism has nano-scale lifting precision, millimeter-scale movement stroke and relatively high bearing capacity, and a high-performance and low-cost lifting solution is provided.

Description

Technical Field

[0001] The invention relates to the field of precision machining and precision detection, and in particular to a high-rigidity macro-micro two-stage lifting platform. Background Art

[0002] In the technological wave of the 21st century, the field of civilian optics has experienced unprecedented development. With the continuous upgrading of smartphone cameras, the popularization of virtual reality technology and the innovation of medical imaging equipment, not only has the performance of optical products been improved, but also higher requirements have been placed on precision processing and testing technologies in the manufacturing process.

[0003] In the process of precision machining and precision testing, high-precision lifting platforms play a vital role. This type of lifting platform is used to achieve precise vertical movement of workpieces or tools. It must not only be able to make tiny displacements, but also ensure the accuracy and repeatability of these displacements to ensure the accuracy of the machining or testing process. Nowadays, the accuracy requirements for this type of lifting platform have gradually increased from micrometers to nanometers.

[0004] In order to achieve nanometer-level lifting accuracy, researchers have developed a micro-nano lifting platform driven by piezoelectric ceramics, which can achieve very fine displacement control by using the piezoelectric effect. However, this technology also has obvious limitations: the travel and load capacity of piezoelectric ceramics are very limited, and they are easily damaged when subjected to tangential forces. In short, there is currently no lifting platform that can maintain nanometer-level precision while having a millimeter-level range of motion and the ability to withstand various outward loads. Therefore, there is an urgent need to develop a new type of high-performance lifting platform that has micro-nano lifting accuracy, the travel of a mechanical lifting platform, and the ability to withstand external loads.

[0005] Therefore, technicians in this field are committed to developing a high-rigidity macro-micro two-stage lifting platform. Summary of the invention

[0006] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is that the existing lifting platform cannot take into account both the requirements of large stroke and micro-feed.

[0007] To achieve the above object, the present invention provides a high-rigidity macro-micro two-stage lifting platform, which includes a lower moving platform, an upper moving platform, a linear motor module, a piezoelectric ceramic module, and a first group of cross roller guide rail modules, wherein:

[0008] The lower movable platform is located at the lower part of the lifting platform, and comprises a base and a lower sliding plate, and the lower sliding plate is fixedly connected to the first group of cross roller guide rail modules;

[0009] The upper movable platform is located on the upper part of the lifting platform and comprises an upper sliding plate, and the upper sliding plate is fixedly connected to the first group of cross roller guide rail modules;

[0010] The linear motor module comprises a linear motor magnetic track and a linear motor coil, wherein the linear motor magnetic track is fixedly connected to the base, and the linear motor coil is fixedly connected to the lower sliding plate, and the linear motor module drives the lower moving platform to achieve lifting and lowering of a millimeter-level stroke;

[0011] The piezoelectric ceramic module includes piezoelectric ceramics and a piezoelectric ceramic sleeve. The piezoelectric ceramic sleeve is fixedly mounted on the side of the lower sliding plate, the piezoelectric ceramic is mounted inside the piezoelectric ceramic sleeve, the extended end of the piezoelectric ceramic is in contact with the side of the upper sliding plate, and the piezoelectric ceramic module drives the upper moving platform to achieve micron-level lifting and lowering.

[0012] Furthermore, the lower mobile platform further comprises: a second group of cross roller guide rail modules and a pneumatic brake module, wherein:

[0013] The second group of cross roller guide modules comprises a fifth cross roller guide, a sixth cross roller guide, a seventh cross roller guide, an eighth cross roller guide, a third guide rail retainer and a fourth guide rail retainer, wherein the fifth cross roller guide and the seventh cross roller guide are respectively fixedly connected to the base surface by screws, the sixth cross roller guide and the eighth cross roller guide are respectively fixedly connected to the lower sliding plate by screws, the fifth cross roller guide, the sixth cross roller guide and the third guide rail retainer are slidably connected, and the seventh cross roller guide, the eighth cross roller guide and the fourth guide rail retainer are slidably connected;

[0014] The pneumatic brake module includes a pneumatic brake and a brake seat. The pneumatic brake is fixedly mounted on both sides of the upper surface of the base through the brake seat. The groove of the pneumatic brake is opposite to the protrusions on both sides of the lower sliding plate. The number of the pneumatic brake and the brake seat is set to two pairs.

[0015] Further, the fifth cross roller guide and the seventh cross roller guide, the sixth cross roller guide and the eighth cross roller guide are symmetrically distributed with respect to the symmetric center plane of the lifting platform, and the bottom surfaces of the fifth cross roller guide, the sixth cross roller guide, the seventh cross roller guide and the eighth cross roller guide are in the same plane;

[0016] The third guide rail retainer and the fourth guide rail retainer are symmetrically distributed relative to the symmetrical center plane of the lifting platform, and respectively slide in a rectangular space formed by the overlapping parts of the inner surfaces of the second group of cross roller guide rail modules.

[0017] Furthermore, the upper movable platform further comprises: a third group of cross roller guide rail modules, a work surface base and a work surface, wherein:

[0018] The third group of cross roller guide modules includes a ninth cross roller guide, a tenth cross roller guide, an eleventh cross roller guide, a twelfth cross roller guide, a fifth guide retainer and a sixth guide retainer, wherein the ninth cross roller guide and the eleventh cross roller guide are respectively fixedly connected to the surface of the upper sliding plate by screws, the tenth cross roller guide and the twelfth cross roller guide are respectively fixedly connected to the work table base by screws, the ninth cross roller guide, the tenth cross roller guide and the fifth guide retainer are slidably connected, and the eleventh cross roller guide, the twelfth cross roller guide and the sixth guide retainer are slidably connected;

[0019] The work surface is fixedly connected to the upper surface of the work surface base by screws.

[0020] Further, the ninth cross roller guide and the eleventh cross roller guide, the tenth cross roller guide and the twelfth cross roller guide are symmetrically distributed with respect to the symmetric center plane of the lifting platform, and the bottom surfaces of the ninth cross roller guide, the tenth cross roller guide, the eleventh cross roller guide and the twelfth cross roller guide are in the same plane;

[0021] The fifth guide rail retainer and the sixth guide rail retainer are symmetrically distributed relative to the symmetric center plane of the lifting platform, and respectively slide in the rectangular space formed by the overlapping parts of the inner surfaces of the third group of cross roller guide rail modules.

[0022] Furthermore, the top surface of the upper sliding plate and the bottom surface of the work surface base are configured as a group of wedge-shaped surfaces, and when the upper sliding plate and the work surface base move relative to each other in the horizontal direction, the work surface base will rise or fall.

[0023] Further, the first group of cross roller guide modules includes a first cross roller guide, a second cross roller guide, a third cross roller guide, a fourth cross roller guide, a first guide retainer and a second guide retainer, wherein:

[0024] The first cross roller guide and the second cross roller guide are fixedly connected to the upper surface of the lower sliding plate by screws, and the third cross roller guide and the fourth cross roller guide are fixedly connected to the upper sliding plate by screws; the first cross roller guide and the second cross roller guide are slidably connected by a first guide holder, and the third cross roller guide and the fourth cross roller guide are slidably connected by a second guide holder;

[0025] The first cross roller guide and the third cross roller guide, the second cross roller guide and the fourth cross roller guide are symmetrically distributed with respect to the symmetrical center plane of the lifting platform; the bottom surfaces of the first cross roller guide, the second cross roller guide, the third cross roller guide and the fourth cross roller guide are in the same plane; the first guide rail retainer and the second guide rail retainer are symmetrically distributed with respect to the symmetrical center plane of the lifting platform, and respectively slide in the rectangular space formed by the overlapping parts of the inner surfaces of the first group of cross roller guide modules.

[0026] Furthermore, the piezoelectric ceramic sleeve includes a lower half of the piezoelectric ceramic sleeve and an upper half of the piezoelectric ceramic sleeve, the upper surface of the lower half of the piezoelectric ceramic sleeve and the lower surface of the upper half of the piezoelectric ceramic sleeve are both set as semi-cylindrical surfaces, the lower half of the piezoelectric ceramic sleeve is fixedly mounted on the side of the lower sliding plate, the lower half of the piezoelectric ceramic sleeve and the upper half of the piezoelectric ceramic sleeve are fixed by screws, and the lower half of the piezoelectric ceramic sleeve and the upper half of the piezoelectric ceramic sleeve jointly clamp the cylindrical outer surface of the piezoelectric ceramic.

[0027] Furthermore, a pair of tension springs are arranged on both sides of the piezoelectric ceramic, the first end of the tension spring is fixed to the lower half of the piezoelectric ceramic sleeve through a spring pull pin, and the second end of the tension spring is fixed to the upper sliding plate through a spring pull rod, and the tension spring is used to keep the extended end of the piezoelectric ceramic always in contact with the side of the upper sliding plate to prevent the piezoelectric ceramic from colliding with the upper sliding plate after separation.

[0028] Furthermore, the lifting platform is provided with a guide rod assembly, and the guide rod assembly is provided in two groups, and the two groups of guide rod assemblies are symmetrically distributed relative to the symmetric center plane of the lifting platform;

[0029] The guide rod assembly includes a guide rod, a guide rod sleeve and a rod sleeve seat. The guide rod, the guide rod sleeve and the rod sleeve seat are coaxially installed. The guide rod is fixedly connected to the bottom surface of the work table by screws, and the guide rod sleeve is fixedly installed on the upper surface of the base through the rod sleeve seat.

[0030] In a preferred embodiment of the present invention, compared with the prior art, the present invention has the following beneficial effects:

[0031] 1. The present invention adopts a macro-micro two-stage lifting mechanism. The linear motor drives the lower moving platform to achieve long-stroke lifting, and the piezoelectric ceramic micro-drives the upper moving platform to achieve nano-level lifting. The two are used together to meet the requirements of long stroke and micro-feed, solving the problem that the lifting platform cannot meet the requirements of long stroke and micro-feed, and providing a new solution for high-precision lifting in the field of processing and detection;

[0032] 2. The present invention adopts a combined structure of a wedge-shaped slider and a linear guide rail to convert the external force on the work surface into a positive pressure on the piezoelectric ceramics, thereby improving the load-bearing and rigidity of the mechanism, solving the problem that the lifting structure driven by piezoelectric ceramics cannot withstand tangential forces, and providing a compact structural solution for the lifting platform;

[0033] 3. The present invention adopts double pneumatic brakes to fix the lower mobile platform, so that the lifting platform can withstand greater external force, solving the problem of small-sized lifting platforms being limited in their ability to withstand external force.

[0034] The concept, specific structure and technical effects of the present invention will be further described below in conjunction with the accompanying drawings to fully understand the purpose, characteristics and effects of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 2. It is a schematic front view of a high-rigidity macro-micro two-stage lifting platform according to an embodiment of the present invention;

[0036] Figure 2 2 is a schematic diagram of a rear view of a high-rigidity macro-micro two-stage lifting platform according to an embodiment of the present invention;

[0037] Figure 3 2 is a schematic side view of a high-rigidity macro-micro two-stage lifting platform according to an embodiment of the present invention;

[0038] Figure 4 is a schematic diagram of an axonometric view of a high-rigidity macro-micro two-stage lifting platform according to an embodiment of the present invention;

[0039] Figure 5 is an exploded view of the relative positions of the cross roller guide rails of an embodiment of the present invention;

[0040] Figure 6 1 is a diagram showing the installation position of piezoelectric ceramics according to an embodiment of the present invention.

[0041] The descriptions of the symbols in the figure are as follows:

[0042] 1-base, 2-1-fifth cross roller guide, 2-2-sixth cross roller guide, 2-3-third guide holder, 3-1-seventh cross roller guide, 3-2-eighth cross roller guide, 3-3-fourth guide holder, 4-lower sliding plate, 5-1-linear motor magnetic track, 5-2-linear motor coil, 6-1-first pneumatic brake, 6-2-second pneumatic brake, 7-1-first brake seat, 7-2-second brake seat, 8-upper sliding plate, 9-1-ninth cross roller guide, 9-2-tenth cross roller guide, 9-3-fifth guide holder, 10-1-eleventh cross roller guide, 10-2-twelfth cross roller guide, 10-3-sixth guide holder, 11-work table base, 12-work table, 13- 1-first cross roller guide, 13-2-second cross roller guide, 13-3-first guide rail retainer, 14-1-third cross roller guide, 14-2-fourth cross roller guide, 14-3-second guide rail retainer, 15-1-lower half of piezoelectric ceramic sleeve, 15-2-upper half of piezoelectric ceramic sleeve, 16-piezoelectric ceramic, 16-1-extended end of piezoelectric ceramic, 17-1-first guide rod, 17-2-second guide rod, 18-1-first guide rod sleeve, 18-2-second guide rod sleeve, 19-1-first rod sleeve seat, 19-2-second rod sleeve seat, 20-linear grating scale, 21-grating scale reading head, 22-reading head seat, 23-1-first tension spring, 24-1-first spring rivet, 25-spring pull rod, 26-center plane of symmetry. DETAILED DESCRIPTION

[0043] The following describes several preferred embodiments of the present invention with reference to the drawings in the specification, so that the technical content is clearer and easier to understand. The present invention can be embodied in many different forms of embodiments, and the protection scope of the present invention is not limited to the embodiments mentioned in the text.

[0044] In the drawings, components with the same structure are indicated by the same numerical reference numerals, and components with similar structures or functions are indicated by similar numerical reference numerals. The size and thickness of each component shown in the drawings are arbitrarily shown, and the present invention does not limit the size and thickness of each component. In order to make the illustration clearer, the thickness of the components is appropriately exaggerated in some places in the drawings.

[0045] like Figure 1 As shown, the embodiment of the present invention provides a high-rigidity macro-micro two-stage lifting platform to meet the lifting needs of high precision, long stroke and large load in the field of precision machining and precision detection. The lifting platform not only has nanometer-level lifting accuracy and millimeter-level movement stroke, but also has a large load-bearing capacity, providing a high-performance, low-cost lifting solution for the field of precision machining and precision detection.

[0046] Specifically, the high-rigidity macro-micro two-stage lifting platform provided in this embodiment includes a lower moving platform, an upper moving platform, a linear motor module, a piezoelectric ceramic module, and a first group of cross roller guide rail modules, wherein:

[0047] The lower mobile platform is located at the lower part of the lifting platform, and comprises a base 1 and a lower sliding plate 4, wherein the lower sliding plate 4 is fixedly connected to the first set of cross roller guide rail modules;

[0048] The upper movable platform is located on the upper part of the lifting platform and is provided with an upper sliding plate 8, and the upper sliding plate 8 is fixedly connected to the first set of cross roller guide rail modules;

[0049] The linear motor module includes a linear motor magnetic track 5-1 and a linear motor coil 5-2. The linear motor magnetic track 5-1 is fixedly connected to the base 1, and the linear motor coil 5-2 is fixedly connected to the lower sliding plate 4. The linear motor module drives the lower moving platform to achieve millimeter-level lifting and lowering.

[0050] The piezoelectric ceramic module includes a piezoelectric ceramic 16 and a piezoelectric ceramic sleeve. The piezoelectric ceramic sleeve is fixedly mounted on the side of the lower sliding plate 4. The piezoelectric ceramic 16 is mounted inside the piezoelectric ceramic sleeve. The piezoelectric ceramic extension end 16-1 contacts the side of the upper sliding plate 8. The piezoelectric ceramic module drives the upper moving platform to achieve micron-level lifting and lowering.

[0051] The first group of cross roller guide modules includes a first cross roller guide 13-1, a second cross roller guide 13-2, a third cross roller guide 14-1, a fourth cross roller guide 14-2, a first guide retainer 13-3 and a second guide retainer 14-3, wherein:

[0052] The first cross roller guide 13-1 and the second cross roller guide 13-2 are fixedly connected to the upper surface of the lower sliding plate 4 by screws, and the third cross roller guide 14-1 and the fourth cross roller guide 14-2 are fixedly connected to the upper sliding plate 8 by screws; the first cross roller guide 13-1 and the second cross roller guide 13-2 are slidingly connected by the first guide retainer 13-3, and the third cross roller guide 14-1 and the fourth cross roller guide 14-2 are slidingly connected by the second guide retainer 14-3. The first cross roller guide 13-1 and the third cross roller guide 14-1, the second cross roller guide 13-2 and the fourth cross roller guide 14-2 are symmetrically distributed with respect to the symmetry center plane 26 of the lifting platform; the bottom surfaces of the first cross roller guide 13-1, the second cross roller guide 13-2, the third cross roller guide 14-1 and the fourth cross roller guide 14-2 are in the same plane; the first guide retainer 13-3 and the second guide retainer 14-3 are symmetrically distributed with respect to the symmetry center plane of the lifting platform, and slide respectively in the rectangular space formed by the overlapping parts of the inner surfaces of the first group of cross roller guide modules.

[0053] like Figure 1 and Figure 5 As shown, the lower mobile platform also includes: a second group of cross roller guide modules and a pneumatic brake module, wherein:

[0054] The second group of cross roller guide modules includes a fifth cross roller guide 2-1, a sixth cross roller guide 2-2, a seventh cross roller guide 3-1, an eighth cross roller guide 3-2, a third guide retainer 2-3 and a fourth guide retainer 3-3. The fifth cross roller guide 2-1 and the seventh cross roller guide 3-1 are fixedly connected to the surface of the base 1 by screws, respectively. The sixth cross roller guide 2-2 and the eighth cross roller guide 3-2 are fixedly connected to the lower sliding plate 4 by screws, respectively. The fifth cross roller guide 2-1, the sixth cross roller guide 2-2 and the third guide retainer 2-3 are slidably connected. The seventh cross roller guide 3-1, the eighth cross roller guide 3-2 and the fourth guide retainer 3-3 are slidably connected.

[0055] In this embodiment, the fifth cross roller guide 2-1 and the seventh cross roller guide 3-1, the sixth cross roller guide 2-2 and the eighth cross roller guide 3-2 are symmetrically distributed with respect to the symmetric center plane 26 of the lifting platform, and the bottom surfaces of the fifth cross roller guide 2-1, the sixth cross roller guide 2-2, the seventh cross roller guide 3-1 and the eighth cross roller guide 3-2 are in the same plane. The third guide holder 2-3 and the fourth guide holder 3-3 are symmetrically distributed with respect to the symmetric center plane 26 of the lifting platform, and slide in the rectangular space formed by the overlapping parts of the inner surfaces of the second group of cross roller guide modules respectively.

[0056] The pneumatic brake module includes a pneumatic brake and a brake seat. The pneumatic brake is fixedly mounted on both sides of the upper surface of the base 1 through the brake seat. The groove of the pneumatic brake is opposite to the protrusions on both sides of the lower sliding plate 4.

[0057] In this embodiment, the number of pneumatic brakes and brake seats is set to two pairs, and the first pneumatic brake 6-1 and the second pneumatic brake 6-2 are fixedly installed on both sides of the upper surface of the base 1 by holding the first brake seat 7-1 and the second brake seat 7-2 respectively, and the grooves of the first pneumatic brake 6-1 and the second pneumatic brake 6-2 are opposite to the protrusions on both sides of the lower sliding plate 4.

[0058] like Figure 1 and Figure 5 As shown, the upper mobile platform also includes: a third group of cross roller guide rail modules, a work surface base and a work surface, wherein:

[0059] The work surface is fixedly connected to the upper surface of the work surface base by screws.

[0060] The third group of cross roller guide modules includes a ninth cross roller guide 9-1, a tenth cross roller guide 9-2, an eleventh cross roller guide 10-1, a twelfth cross roller guide 10-2, a fifth guide retainer 9-3 and a sixth guide retainer 10-3. The ninth cross roller guide 9-1 and the eleventh cross roller guide 10-1 are fixedly connected to the surface of the upper sliding plate 8 by screws, respectively. The tenth cross roller guide 9-2 and the twelfth cross roller guide 10-2 are fixedly connected to the work table base 11 by screws, respectively. The ninth cross roller guide 9-1, the tenth cross roller guide 9-2 and the fifth guide retainer 9-3 are slidably connected. The eleventh cross roller guide 10-1, the twelfth cross roller guide 10-2 and the sixth guide retainer 10-3 are slidably connected.

[0061] The ninth cross roller guide 9-1 and the eleventh cross roller guide 10-1, the tenth cross roller guide 9-2 and the twelfth cross roller guide 10-2 are symmetrically distributed with respect to the symmetric center plane 26 of the lifting platform, and the bottom surfaces of the ninth cross roller guide 9-1, the tenth cross roller guide 9-2, the eleventh cross roller guide 10-1 and the twelfth cross roller guide 10-2 are in the same plane. The fifth guide retainer 9-3 and the sixth guide retainer 10-3 are also symmetrically distributed with respect to the symmetric center plane 26 of the lifting platform, and slide in the rectangular space formed by the overlapping parts of the inner surfaces of the third group of cross roller guide modules respectively.

[0062] like Figure 6 As shown, in this embodiment, the piezoelectric ceramic 16 is set to a cylindrical shape and installed in the piezoelectric ceramic sleeve. The piezoelectric ceramic sleeve includes a piezoelectric ceramic sleeve lower half 15-1 and a piezoelectric ceramic sleeve upper half 15-2. The upper surface of the piezoelectric ceramic sleeve lower half 15-1 and the lower surface of the piezoelectric ceramic sleeve upper half 15-2 are both set to a semi-cylindrical surface. The piezoelectric ceramic sleeve lower half 15-1 is fixedly installed on the side of the lower sliding plate 4. The piezoelectric ceramic sleeve lower half 15-1 and the piezoelectric ceramic sleeve upper half 15-2 are fixed by screws. The piezoelectric ceramic sleeve lower half 15-1 and the piezoelectric ceramic sleeve upper half 15-2 jointly clamp the cylindrical outer surface of the piezoelectric ceramic 16.

[0063] In order to eliminate the tension of the piezoelectric ceramics transmitted during the vertical movement of the lifting platform, the present invention sets a pair of tension springs on both sides of the piezoelectric ceramics 16. One end of the tension spring is fixed to the lower half 15-1 of the piezoelectric ceramic sleeve by a spring rivet, and the other end of the tension spring is fixed to the upper sliding plate 8 by a spring pull rod 25. The tension spring is used to keep the extended end 16-1 of the piezoelectric ceramics always in contact with the side of the upper sliding plate 8 to prevent the piezoelectric ceramics 16 from colliding with the upper sliding plate 8 after separation. The pair of tension springs can almost eliminate the effect of positive tension. Figure 6In the figure, one end of the first tension spring 23-1 is fixed to the lower half 15-1 of the piezoelectric ceramic sleeve through the first spring rivet 24-1, and the other end of the tension spring is fixed to the upper sliding plate 8 through the spring pull rod 25. The tension spring is used to keep the piezoelectric ceramic extended end 16-1 always in contact with the side of the upper sliding plate 8.

[0064] like Figure 3 As shown, the lifting platform provided in this embodiment is also provided with a guide rod assembly, which is arranged in two groups, and the two groups of guide rod assemblies are symmetrically distributed relative to the symmetry center plane 26 of the lifting platform; the guide rod assembly includes a guide rod, a guide rod sleeve and a rod sleeve seat, the guide rod, the guide rod sleeve and the rod sleeve seat are coaxially installed, the guide rod is fixedly connected to the bottom surface of the work table 12 by screws, and the guide rod sleeve is fixedly installed on the upper surface of the base 1 through the rod sleeve seat. In a preferred embodiment of the present invention, the first guide rod 17-1, the first guide rod sleeve 18-1 and the first rod sleeve seat 19-1 are coaxially installed, and the second guide rod 17-2, the second guide rod sleeve 18-2 and the second rod sleeve seat 19-2 are coaxially installed, wherein the first guide rod sleeve 18-1 and the second guide rod sleeve 18-2 are fixedly installed on the upper surface of the base 1 through the first rod sleeve seat 19-1 and the second rod sleeve seat 19-2, respectively.

[0065] like Figure 3 As shown, this embodiment also provides a linear grating ruler 20 , which is fixed on the right side of the worktable base 11 , and the grating ruler reading head 21 is fixed on the upper surface of the base 1 through the reading head seat 22 , and is installed opposite to the linear grating ruler 20 .

[0066] In view of the problem that the piezoelectric ceramic-driven nano-lifting platform in the prior art can only withstand positive pressure and a small amount of positive tension, but cannot withstand tangential force, in this embodiment, a combined structure of a wedge-shaped slider and a linear guide rail is used to convert the external force into positive pressure on the piezoelectric ceramic, thereby improving the load-bearing capacity and rigidity of the mechanism. Figure 3 As shown, the top surface of the upper sliding plate 8 and the bottom surface of the work surface base 11 are set as a set of wedge-shaped surfaces. When the upper sliding plate 8 and the work surface base 11 move relative to each other in the horizontal direction, the work surface base 11 will rise or fall. Through the combined structure of the wedge-shaped slider plus the linear guide rail and the guide rod assembly, the degree of freedom of the lifting platform can be limited to movement in the up and down directions only, and the external force transmitted to the piezoelectric ceramic 16 is only positive pressure and tension. In combination with a pair of tension springs, the effect of positive tension can be almost eliminated, thereby solving the problem that the lifting structure driven by piezoelectric ceramics cannot withstand tangential forces, and at the same time providing a compact structural solution for the lifting platform.

[0067] Take the lifting platform as an example to explain the movement of each part. Figure 3As shown, when the linear motor is powered on to generate driving force, the linear motor coil 5-2 drives the lower sliding plate 4 to move to the right, and at the same time drives the piezoelectric ceramic 16 to push the upper sliding plate 8 to move to the right. Finally, under the action of the wedge structure and the constraint of the guide rod assembly, the worktable base 11 moves vertically upward to achieve a large stroke rise of the lifting platform. When the lifting platform slightly rises, the pneumatic brake fixes the lower sliding plate 4 through the clamping force. At this time, the piezoelectric ceramic 16 extends through the piezoelectric ceramic extension end 16-1, pushing the upper sliding plate 8 to move slightly to the right. Finally, under the action of the wedge structure, the worktable base 11 moves vertically upward slightly to achieve a slight rise of the lifting platform.

[0068] The external force on the lifting platform is explained as follows: Since the work surface 12 and the work surface base 11 have only one degree of freedom to move up and down, any external force not in this direction will eventually be transmitted to the base 1 step by step through the first guide rod 17-1, the second guide rod 17-2, the first guide rod sleeve 18-1, the second guide rod sleeve 18-2, and the first rod sleeve seat 19-1 and the second rod sleeve seat 19-2. When the work surface 12 is subjected to downward pressure, the pressure will be converted into downward pressure and leftward thrust on the upper sliding plate 8 through the wedge structure. Similarly, when the work surface 12 is subjected to upward tension, it will be converted into upward and rightward tension on the upper sliding plate 8 through the wedge structure. When the tension is less than the tension of the tension spring, the piezoelectric ceramic extension end 16-1 of the piezoelectric ceramic 16 is still in contact with the upper sliding plate 8 and bears the pressure of the upper sliding plate 8. Therefore, the piezoelectric ceramic 16 is always subjected to positive pressure. When the pneumatic brake is fixed to the lower sliding plate 4 by the clamping force, the pressure on the piezoelectric ceramic 16 will be transmitted to the base 1 step by step through the piezoelectric ceramic sleeve, the lower sliding plate 4, the pneumatic brake, and the brake seat. At this time, no external force is transmitted to the linear motor. Because the clamping force of the pneumatic brake is much greater than the driving force of the linear motor, the lifting platform of the present invention can withstand a larger external load.

[0069] Therefore, in this embodiment, the freedom of the lifting platform can be limited to movement in the up and down directions only through the combined structure of the wedge-shaped slider plus the linear guide rail and the guide rod assembly, and the external force transmitted to the piezoelectric ceramic 16 is only positive pressure and tension. By setting up a pair of tension springs, the effect of the positive tension can be almost eliminated, which solves the problem that the lifting structure driven by the piezoelectric ceramic cannot withstand the tangential force, and at the same time provides a compact structural solution for the lifting platform.

[0070] Compared with the prior art, the high-rigidity macro-micro two-stage lifting platform provided by the embodiment of the present invention has the following beneficial effects:

[0071] 1. The existing lifting platform cannot take into account both the requirements of large stroke and micro-feed. The present invention adopts a macro-micro two-level lifting mechanism: the linear motor drives the lower moving platform to achieve large stroke lifting; the piezoelectric ceramic micro-drives the upper moving platform to achieve nanometer-level lifting. The stroke of the linear motor is usually at the millimeter level and the accuracy is at the micron level. The stroke of the piezoelectric ceramic is usually at the micron level and the accuracy is at the nanometer level. The two are used together to take into account both the requirements of large stroke and micro-feed, solving the problem that the lifting platform cannot take into account both large stroke and micro-feed, and providing a new solution for high-precision lifting in the fields of processing and detection.

[0072] 2. In view of the problem that the existing piezoelectric ceramic driven nano-lifting platform can only withstand positive pressure and a small amount of positive tension, but cannot withstand tangential force, the present invention adopts a combination structure of a wedge-shaped slider and a linear guide rail to convert the external force on the work surface into positive pressure on the piezoelectric ceramic, thereby improving the load-bearing and rigidity of the mechanism. Through the combination structure of a wedge-shaped slider, a linear guide rail and a guide rod assembly, the degree of freedom of the lifting platform can be limited to movement in the up and down directions only, and the external force transmitted to the piezoelectric ceramic is only positive pressure and tension. In combination with a pair of tension springs, the positive tension can be almost eliminated, solving the problem that the piezoelectric ceramic driven lifting structure cannot withstand tangential force, and at the same time providing a compact structural solution for the lifting platform.

[0073] 3. In view of the problem that the existing small-sized lifting platforms are unable to withstand large external loads due to the driving force of the motor, the present invention fixes the lower mobile platform with a double pneumatic brake, so that the lifting platform can withstand greater external forces. Considering that in practical applications, when the lifting platform is slightly lifted or lowered, the linear motor is in a non-working state, and the guide rail is usually driven by piezoelectric ceramics for micro-feeding, a double brake structure is adopted to lock the lower mobile platform when it is working. The locking force is much greater than the driving force of the motor, so the lifting platform can withstand greater external forces, solving the problem of small-sized lifting platforms being limited in their ability to withstand external forces.

[0074] The present invention provides a high-rigidity macro-micro two-stage lifting platform for the lifting requirements of high precision, long stroke, and large load in the field of precision machining and precision detection, filling the technical gap in this field. The lifting platform not only has nanometer-level lifting accuracy and millimeter-level motion stroke, but also has a large load-bearing capacity, providing a high-performance, low-cost lifting solution for the field of precision machining and precision detection, and can be widely used in the tool holder and workpiece height adjustment of precision machine tools, and the sample height adjustment of precision detection instruments, and has broad application prospects.

[0075] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A high-rigidity macro-micro two-stage lifting platform, characterized in that: The lifting platform includes a lower moving platform, an upper moving platform, a linear motor module, a piezoelectric ceramic module, and a first group of cross roller guide rail modules, wherein: The lower movable platform is located at the lower part of the lifting platform, and comprises a base and a lower sliding plate, and the lower sliding plate is fixedly connected to the first group of cross roller guide rail modules; The upper movable platform is located on the upper part of the lifting platform and comprises an upper sliding plate, and the upper sliding plate is fixedly connected to the first group of cross roller guide rail modules; The linear motor module comprises a linear motor magnetic track and a linear motor coil, wherein the linear motor magnetic track is fixedly connected to the base, and the linear motor coil is fixedly connected to the lower sliding plate, and the linear motor module drives the lower moving platform to achieve lifting and lowering of a millimeter-level stroke; The piezoelectric ceramic module includes piezoelectric ceramics and a piezoelectric ceramic sleeve. The piezoelectric ceramic sleeve is fixedly mounted on the side of the lower sliding plate, the piezoelectric ceramic is mounted inside the piezoelectric ceramic sleeve, the extended end of the piezoelectric ceramic is in contact with the side of the upper sliding plate, and the piezoelectric ceramic module drives the upper moving platform to achieve micron-level lifting and lowering.

2. The lifting platform according to claim 1, characterized in that: The lower mobile platform also includes: a second group of cross roller guide modules and a pneumatic brake module, wherein: The second group of cross roller guide modules comprises a fifth cross roller guide, a sixth cross roller guide, a seventh cross roller guide, an eighth cross roller guide, a third guide rail retainer and a fourth guide rail retainer, wherein the fifth cross roller guide and the seventh cross roller guide are respectively fixedly connected to the base surface by screws, the sixth cross roller guide and the eighth cross roller guide are respectively fixedly connected to the lower sliding plate by screws, the fifth cross roller guide, the sixth cross roller guide and the third guide rail retainer are slidably connected, and the seventh cross roller guide, the eighth cross roller guide and the fourth guide rail retainer are slidably connected; The pneumatic brake module includes a pneumatic brake and a brake seat. The pneumatic brake is fixedly mounted on both sides of the upper surface of the base through the brake seat. The groove of the pneumatic brake is opposite to the protrusions on both sides of the lower sliding plate. The number of the pneumatic brake and the brake seat is set to two pairs.

3. The lifting platform according to claim 2, characterized in that: The fifth cross roller guide, the seventh cross roller guide, the sixth cross roller guide and the eighth cross roller guide are symmetrically distributed with respect to the symmetric center plane of the lifting platform, and the bottom surfaces of the fifth cross roller guide, the sixth cross roller guide, the seventh cross roller guide and the eighth cross roller guide are in the same plane; The third guide rail retainer and the fourth guide rail retainer are symmetrically distributed relative to the symmetrical center plane of the lifting platform, and respectively slide in a rectangular space formed by the overlapping parts of the inner surfaces of the second group of cross roller guide rail modules.

4. The lifting platform according to claim 3, characterized in that: The upper mobile platform also includes: a third group of cross roller guide rail modules, a work surface base and a work surface, wherein: The third group of cross roller guide modules includes a ninth cross roller guide, a tenth cross roller guide, an eleventh cross roller guide, a twelfth cross roller guide, a fifth guide retainer and a sixth guide retainer, wherein the ninth cross roller guide and the eleventh cross roller guide are respectively fixedly connected to the surface of the upper sliding plate by screws, the tenth cross roller guide and the twelfth cross roller guide are respectively fixedly connected to the work table base by screws, the ninth cross roller guide, the tenth cross roller guide and the fifth guide retainer are slidably connected, and the eleventh cross roller guide, the twelfth cross roller guide and the sixth guide retainer are slidably connected; The work surface is fixedly connected to the upper surface of the work surface base by screws.

5. The lifting platform according to claim 4, characterized in that: The ninth cross roller guide, the eleventh cross roller guide, the tenth cross roller guide and the twelfth cross roller guide are symmetrically distributed with respect to the symmetric center plane of the lifting platform, and the bottom surfaces of the ninth cross roller guide, the tenth cross roller guide, the eleventh cross roller guide and the twelfth cross roller guide are in the same plane; The fifth guide rail retainer and the sixth guide rail retainer are symmetrically distributed relative to the symmetric center plane of the lifting platform, and respectively slide in the rectangular space formed by the overlapping parts of the inner surfaces of the third group of cross roller guide rail modules.

6. The lifting platform according to claim 5, characterized in that: The top surface of the upper sliding plate and the bottom surface of the work surface base are arranged as a group of wedge-shaped surfaces. When the upper sliding plate and the work surface base move relative to each other in the horizontal direction, the work surface base will rise or fall.

7. The lifting platform according to claim 6, characterized in that: The first group of cross roller guide modules includes a first cross roller guide, a second cross roller guide, a third cross roller guide, a fourth cross roller guide, a first guide retainer and a second guide retainer, wherein: The first cross roller guide and the second cross roller guide are fixedly connected to the upper surface of the lower sliding plate by screws, and the third cross roller guide and the fourth cross roller guide are fixedly connected to the upper sliding plate by screws; the first cross roller guide and the second cross roller guide are slidably connected by a first guide holder, and the third cross roller guide and the fourth cross roller guide are slidably connected by a second guide holder; The first cross roller guide and the third cross roller guide, the second cross roller guide and the fourth cross roller guide are symmetrically distributed with respect to the symmetrical center plane of the lifting platform; the bottom surfaces of the first cross roller guide, the second cross roller guide, the third cross roller guide and the fourth cross roller guide are in the same plane; the first guide rail retainer and the second guide rail retainer are symmetrically distributed with respect to the symmetrical center plane of the lifting platform, and respectively slide in the rectangular space formed by the overlapping parts of the inner surfaces of the first group of cross roller guide modules.

8. The lifting platform according to claim 7, characterized in that: The piezoelectric ceramic sleeve comprises a lower half of the piezoelectric ceramic sleeve and an upper half of the piezoelectric ceramic sleeve, the upper surface of the lower half of the piezoelectric ceramic sleeve and the lower surface of the upper half of the piezoelectric ceramic sleeve are both set as semi-cylindrical surfaces, the lower half of the piezoelectric ceramic sleeve is fixedly mounted on the side of the lower sliding plate, the lower half of the piezoelectric ceramic sleeve and the upper half of the piezoelectric ceramic sleeve are fixed by screws, and the lower half of the piezoelectric ceramic sleeve and the upper half of the piezoelectric ceramic sleeve jointly clamp the cylindrical outer surface of the piezoelectric ceramic.

9. The lifting platform according to claim 8, characterized in that: A pair of tension springs are arranged on both sides of the piezoelectric ceramic, the first end of the tension spring is fixed to the lower half of the piezoelectric ceramic sleeve through a spring pull pin, and the second end of the tension spring is fixed to the upper sliding plate through a spring pull rod, and the tension spring is used to keep the extended end of the piezoelectric ceramic always in contact with the side of the upper sliding plate to prevent the piezoelectric ceramic from colliding with the upper sliding plate after separation.

10. The lifting platform according to claim 9, characterized in that: The lifting platform is provided with a guide rod assembly, and the guide rod assembly is provided in two groups, and the two groups of guide rod assemblies are symmetrically distributed relative to the symmetric center plane of the lifting platform; The guide rod assembly includes a guide rod, a guide rod sleeve and a rod sleeve seat. The guide rod, the guide rod sleeve and the rod sleeve seat are coaxially installed. The guide rod is fixedly connected to the bottom surface of the work table by screws, and the guide rod sleeve is fixedly installed on the upper surface of the base through the rod sleeve seat.

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