Precise lifting platform

Abstract

The invention provides a precise lifting platform. The precise lifting platform comprises a platform base; the lifting component consists of a first wedge-shaped block, a first crossed roller guide rail, a second wedge-shaped block, a second crossed roller guide rail and at least one pair of linear guide mechanisms; the first wedge-shaped block is connected with one part of the first crossed roller guide rail, and the first wedge-shaped block can be guided to move in the first direction; the second wedge-shaped block is connected with the first wedge-shaped block through a second crossed roller guide rail and a linear guide mechanism, so that the second wedge-shaped block can move along with the movement of the first wedge-shaped block; the linear motor is connected with the first wedge-shaped block and can be used for driving the first wedge-shaped block to move; and the feedback device is arranged on the second wedge-shaped block and / or the platform base and can be used for acquiring position parameters of the second wedge-shaped block. The precise lifting platform has a long-term market prospect, the movement precision and the movement stability of the precise lifting platform are in the technical leading edge of an existing lifting platform, and certain social benefits can be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of lifting platforms, and in particular to a precision lifting platform. Background Art

[0002] More and more industries are beginning to deeply develop cutting-edge manufacturing technologies such as automation, high precision and ultra-high precision; among them, the growing prosperity of intelligent manufacturing, flexible manufacturing and extreme manufacturing has created an increasing demand for precision machinery and precision instruments, and micro-displacement technology is one of the key technologies for precision machinery and precision instruments, which has accelerated the research and development of micro-displacement technology.

[0003] Generally speaking, micro-displacement technology is widely used in microelectronics manufacturing, biomedical engineering, optical micro-assembly and ultra-precision machining, and the micro-displacement work platform, as the core functional component of micro-displacement technology, has become an important research direction in the field of micro-displacement technology.

[0004] Specifically, a micro-displacement work platform (eg, a precision lifting platform) requires a high-precision micro-motion drive mode under high-speed motion to achieve precise control of the platform within a short stroke.

[0005] Precision lifting platform is one of the important components of precision testing equipment, which can provide accurate movement for fields such as microlithography, CNC machining, biotechnology, integrated circuit packaging equipment, and nano-surface topography measurement. Precision lifting platform with high precision and high stability is of decisive significance to the development of advanced electronic manufacturing equipment. In advanced electronic manufacturing equipment (for example, lithography machine), due to the increasingly smaller size of the products manufactured, advanced electronic manufacturing equipment requires high precision and low friction of rolling bearings and the ability to work in extreme working environments; therefore, the manufacturing and detection of micro-electromechanical systems (MEMS), optical measurement and processing, ultra-precision machining, and aircraft engine measurement and manufacturing are inseparable from precision lifting technology, and lifting platforms with high rigidity and precision small displacement can be an ideal choice.

[0006] Under the guidance of my country's policy of vigorously developing the information industry, IC (Integrated Circuit) manufacturing has entered a new era of vigorous development. With the rapid development of chip lithography and packaging in IC manufacturing, device packaging and assembly in MEMS (Micro Electro Mechanical Systems) manufacturing, high-speed spotting and liquid transfer in biomedical engineering, high-speed precision machining and high-speed scanning detection, etc., extremely high requirements are placed on the motion range, speed, acceleration and motion accuracy of the execution system; therefore, lifting platforms with high-speed and high-precision characteristics have become a research hotspot in the field of advanced manufacturing technology.

[0008] The existing lifting platform still has some defects:

[0009] (1) Most traditional lifting platforms have low lifting accuracy and are difficult to achieve smooth lifting, which makes it impossible to use traditional lifting platforms in some environments that require high lifting accuracy (for example, the ultra-precision Z-axis used in semiconductor or optical platforms cannot achieve high-precision lifting).

[0010] (2) The traditional rotary motor drive method uses a rotary motor drive, and the transmission device uses gears, ball screws and guide rails to achieve linear motion. The advantages of this drive method are mature structure, easy control method, large thrust and low cost. However, the traditional rotary motor drive method needs to go through many intermediate transmission links before it can be converted into linear feed motion. The increase in transmission links will introduce error sources and increase the system inertia, which slows down the dynamic response and limits the improvement of motion acceleration. In addition, the stiffness of the ball screw is low, and its elastic deformation during the movement process limits the overall performance of the system, and it is easy to produce mechanical resonance, which will further deteriorate the motion performance. In addition, the gap and elastic deformation in the above-mentioned intermediate transmission links will introduce a series of nonlinear factors, making it difficult to further improve the control accuracy of the system. Finally, the dead zone and friction factors in the intermediate transmission link have a serious impact on the extremely small stroke motion during the lifting process, thereby limiting the resolution of the existing lifting platform. Due to the existence of the above-mentioned defects, the traditional rotary motor drive method is difficult to meet the increasingly high motion accuracy requirements, and also limits its use and development in precision lifting platforms. Summary of the invention

[0011] The precision lifting platform provided in the present application is intended to overcome at least some of the defects of existing lifting platforms.

[0012] The embodiment of the present invention provides a precision lifting platform. The precision lifting platform comprises: a platform base. The precision lifting platform also comprises:

[0013] A lifting component; the lifting component comprises: a first wedge block, a first cross roller guide, a second wedge block, a second cross roller guide and at least one pair of linear guide mechanisms;

[0014] The first wedge block has a horizontal mounting portion and an oblique mounting portion, and the oblique mounting portion is inclined relative to the horizontal mounting portion; a portion of the first cross roller guide is fixedly mounted on the platform base, and another portion is fixedly connected to the horizontal mounting portion to guide the first wedge block to reciprocate in a first direction;

[0015] The second wedge block has a bearing portion and a mounting portion, and the mounting portion is inclined to the bearing portion; a portion of the second cross roller guide is fixedly mounted on the inclined mounting portion, and another portion is fixedly connected to the mounting portion; a portion of each of the linear guide mechanisms is fixedly mounted on the platform base, and another portion is fixedly connected to the second wedge block;

[0016] The second wedge block can move along a second direction following the movement of the first wedge block in the first direction under the cooperation of the second cross roller guide and the linear guide mechanism, and the second direction and the first direction are orthogonal to each other;

[0017] A linear motor; a portion of the linear motor is fixedly mounted on the platform base, and another portion of the linear motor is fixedly connected to the first wedge block to drive the first wedge block to reciprocate in the first direction;

[0018] Feedback device; the feedback device is installed on the second wedge block and / or the platform base, and is used to obtain the position parameters of the second wedge block.

[0019] In some embodiments, a first angle is formed between the oblique mounting portion and the horizontal mounting portion, a second angle is formed between the assembly portion and the bearing portion, and the first angle is equal to the second angle.

[0020] In some embodiments, the platform base comprises:

[0021] A substrate and a pair of support plates; the pair of support plates are arranged on two sides of the substrate away from each other in the first direction and protrude from the surface of the substrate along the second direction;

[0022] The surface of the substrate and the surfaces of the pair of support plates enclose a receiving space, and the lifting component and the linear motor are both accommodated in the receiving space.

[0023] In some embodiments, the first cross roller guides are arranged in pairs on the surface of the substrate and extend along a first direction;

[0024] The second cross roller guides are arranged in pairs between the first wedge block and the second wedge block and extend along the third direction;

[0025] The third direction is inclined to the first direction or the second direction, and a preset angle between the third direction and the first direction is equal to the first angle or the second angle.

[0026] In some embodiments, the first wedge block is provided with a motor mounting slot, and the horizontal mounting portion and the oblique mounting portion are both located outside the motor mounting slot.

[0027] In some embodiments, the linear motor comprises at least:

[0028] A stator component and a mover component; the stator component is fixedly mounted on the substrate, the mover component is fixedly connected to the first wedge block, and both the stator component and the mover component are located inside the motor mounting slot;

[0029] Wherein, the movable component can move relative to the stator component to drive the first wedge block to reciprocate in the first direction.

[0030] In some embodiments, at least one pair of the linear guide mechanisms is disposed on two sides of the second wedge block that are away from each other in the first direction.

[0031] In some embodiments, the linear guide mechanism comprises:

[0032] A linear guide rail and a slider, one of which is fixedly mounted on the second wedge block, and the other is fixedly connected to the support plate;

[0033] Wherein, the linear guide rail extends along the second direction; the slider is sleeved on the linear guide rail, so that the slider can reciprocate along the second direction on the linear guide rail.

[0034] In some embodiments, the feedback device comprises at least:

[0035] Grating ruler and grating reading head; the grating ruler is attached to the second wedge block, and the grating reading head is connected to the substrate through a reading head fixing block;

[0036] The grating ruler can move relative to the grating reading head following the movement of the second wedge block in the second direction;

[0037] The grating reading head can cover at least a portion of the grating ruler; when the grating ruler moves relative to the grating reading head, the position parameters of the second wedge block can be obtained in real time;

[0038] Wherein, the reading head fixing block has multiple adjustable degrees of freedom.

[0039] In some embodiments, the precision lifting platform further includes:

[0040] A first photoelectric switch, a second photoelectric switch and a shielding plate;

[0041] The first photoelectric switch and the second photoelectric switch are fixed on the substrate, and the first photoelectric switch and the second photoelectric switch are away from each other along the first direction;

[0042] The first photoelectric switch is spaced apart from one end of the substrate in the first direction by a preset distance; the second photoelectric switch is spaced apart from the other end of the substrate in the first direction by a preset distance;

[0043] The shielding plate is fixed on the first wedge-shaped block so that the shielding plate can move following the movement of the first wedge-shaped block.

[0044] In some embodiments, both the first photoelectric switch and the second photoelectric switch may be connected to the movable component via cables, and cooperate with the shielding plate to limit the travel range of the first wedge block moving in the first direction.

[0045] In some embodiments, the precision lifting platform further includes:

[0046] A plurality of anti-collision blocks; the plurality of anti-collision blocks are fixedly mounted on the base plate and are arranged in pairs at both ends of the first wedge-shaped block in the first direction;

[0047] Wherein, when the shielding plate is located at the position of the first photoelectric switch or the second photoelectric switch, the anti-collision block can produce a buffering effect on the first wedge-shaped block.

[0048] At least one advantageous aspect of the precision lifting platform provided by the embodiment of the present invention is that the precision lifting platform adds a first wedge block, a second wedge block, a first cross roller guide, a second cross roller guide and a feedback device, so that the wedge-shaped lifting component, the miniature cross roller guide and the feedback device for obtaining position parameters are combined with each other to form a specific structural design; through the above-mentioned specific structural design and the use of linear motors to replace traditional rotary motors, motion error compensation can be achieved, thereby improving the movement speed and motion accuracy of the lifting platform, and even achieving micron-level motion accuracy, thereby meeting the accuracy and speed requirements of the precision lifting platform, and making the precision lifting platform have the advantage of a more compact structure. The cross roller guide added to the precision lifting platform has the advantages of large contact area and small elastic deformation, so it can achieve high rigidity and high load movement. The precision lifting platform has a long-term market prospect, and its motion accuracy and motion stability are at the forefront of the technology of existing lifting platforms, with great development opportunities and the ability to achieve certain social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] One or more embodiments are exemplarily described by corresponding drawings, which do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and the figures in the drawings do not constitute proportional limitations unless otherwise stated.

[0050] Figure 1 A schematic diagram of the structure of a precision lifting platform provided in an embodiment of the present invention (I);

[0051] Figure 2 A schematic diagram of the structure of a precision lifting platform provided in an embodiment of the present invention (II);

[0052] Figure 3 A three-dimensional exploded view of a precision lifting platform provided in an embodiment of the present invention;

[0053] Figure 4 A schematic structural diagram of a first wedge block provided in an embodiment of the present invention;

[0054] Figure 5 A schematic diagram of the structure of a second wedge block provided in an embodiment of the present invention;

[0055] Figure 6 A front cross-sectional view of the precision lifting platform provided in an embodiment of the present invention.

[0056] Figure numerals: 100, precision lifting platform; 1001, first direction; 1002, second direction; 1, platform base; 11, substrate; 12, support plate; 2, lifting component; 21, first wedge block; 22, first cross roller guide; 23, second wedge block; 24, second cross roller guide; 25, linear guide mechanism; 210, motor mounting groove; 211, horizontal mounting portion; 212, oblique mounting portion; 231, bearing portion; 232, assembly portion; 251, linear guide; 252, slider; 3, linear motor; 31, stator component; 32, mover component; 4, feedback device; 41, grating reading head; 411, reading head fixing block; 5, first photoelectric switch; 6, second photoelectric switch; 7, shielding plate; 8, anti-collision block. DETAILED DESCRIPTION

[0057] The present invention is described in detail below in conjunction with specific embodiments. It should be emphasized that the following description is merely illustrative and is not intended to limit the scope of the present invention and its application.

[0058] It should be noted that, unless otherwise clearly specified and limited, the terms "first direction", "second direction", "third direction", "mutually divergent" and the like used in this specification to indicate orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. The terms such as "installation", "fitting", "connection" and "fixation" should be understood in a broad sense. For example, "connection" can be a fixed connection or a detachable connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; "fixation" can be bolted, snap-fitted or glued; the terms "first", "second" and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated; thus, the features defined as "first", "second" and "third" may explicitly or implicitly include one or more of the features; "multiple" or "several" means two or more; in addition, "and / or" includes any and all combinations of one or more related listed items; for ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0059] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0060] In the embodiments of the present application, the specific shape, structure, size, etc. of the "precision lifting platform" are not limited, and those skilled in the art can selectively use any suitable implementation method according to actual needs.

[0061] Figure 1 A schematic structural diagram of a precision lifting platform provided in an embodiment of the present invention (I). Figure 2 A schematic structural diagram of a precision lifting platform provided in an embodiment of the present invention (II). Figure 3 A three-dimensional exploded view of the precision lifting platform provided in an embodiment of the present invention. Figure 4 A schematic structural diagram of a first wedge block provided in an embodiment of the present invention. Figure 5 A schematic structural diagram of a second wedge block provided in an embodiment of the present invention.

[0062] See also Figure 1-Figure 5 The precision lifting platform 100 includes: a platform base 1. The precision lifting platform 100 also includes: a lifting component 2, a linear motor 3 and a feedback device 4.

[0063] The lifting component 2 includes: a first wedge block 21 , a first cross roller guide 22 , a second wedge block 23 , a second cross roller guide 24 and at least one pair of linear guide mechanisms 25 .

[0064] In addition, the first wedge block 21 has a horizontal mounting portion 211 and an oblique mounting portion 212, and the oblique mounting portion 212 is inclined relative to the horizontal mounting portion 211; one part of the first cross roller guide 22 is fixedly mounted on the platform base 1, and the other part is fixedly connected to the horizontal mounting portion 211 to guide the first wedge block 21 to reciprocate in the first direction 1001.

[0065] In addition, the second wedge block 23 has a bearing portion 231 and an assembly portion 232, and the assembly portion 232 is inclined to the bearing portion 231; one part of the second cross roller guide 24 is fixedly mounted on the inclined mounting portion 212, and the other part is fixedly connected to the assembly portion 232; one part of each linear guide mechanism 25 is fixedly mounted on the platform base 1, and the other part is fixedly connected to the second wedge block 23.

[0066] Moreover, under the cooperation of the second cross roller guide 24 and the linear guide mechanism 25, the second wedge block 23 can move along the second direction 1002 following the movement of the first wedge block 21 in the first direction 1001, and the second direction 1002 and the first direction 1001 are orthogonal to each other.

[0067] It should be noted that one part of the linear motor 3 is fixedly mounted on the platform base 1 , and the other part is fixedly connected to the first wedge block 21 to drive the first wedge block 21 to reciprocate in the first direction 1001 .

[0068] It can be understood that the feedback device 4 is installed on the second wedge block 23 and / or the platform base 1 , and is used to obtain the position parameters of the second wedge block 23 .

[0069] In the embodiment of the present application, the precision lifting platform 100 adds a first wedge block 21, a second wedge block 23, a first cross roller guide 22, a second cross roller guide 24 and a feedback device 4 to form a specific structural design; through the above-mentioned specific structural design and the use of a linear motor 3 to replace the traditional rotary motor, compensation of motion errors can be achieved, thereby improving the movement speed and motion accuracy of the lifting platform, and even achieving micron-level motion accuracy, thereby meeting the accuracy and speed requirements of the precision lifting platform.

[0070] Specifically, the crossed roller guide is a guiding mechanism with high precision, high rigidity, low friction and high repeatability, and can be widely used in high-precision machine tools, industrial robots, semiconductor equipment, aerospace and other fields. The crossed roller guide is composed of a guide frame, guide tracks, rollers and retaining frames, and its characteristic is that the rollers are arranged in an alternating orthogonal manner, and a special retainer and V-shaped track are combined to achieve high-precision linear motion.

[0071] To further explain, the cross roller guide is equipped with high-precision balls and therefore has a smaller friction coefficient, which enables the cross roller guide to achieve high-precision linear motion, thereby meeting the needs of precision machining and positioning; in addition, the cross roller guide increases the effective contact length of the roller body through a unique roller retention mechanism, thereby improving the rigidity of the system (the system can be understood as a precision lifting platform 100 with the above-mentioned cross roller guide), thereby ensuring that the system can maintain a stable motion state under high speed or heavy load conditions; moreover, the cross roller guide has a smaller friction coefficient, which can help reduce energy loss, thereby improving the operating efficiency of the system; finally, during multiple movements or positioning processes, the system can maintain extremely high precision consistency, so the cross roller guide is suitable for occasions that require frequent positioning or repeated processing.

[0072] Generally speaking, the working principle of the cross roller guide is based on the rolling motion of the rollers on the V-shaped raceway surface; specifically, the cylindrical rollers arranged crosswise with each other reciprocate on the precision-ground V-shaped raceway surface, and linear motion is achieved through the contact and rolling of the rollers and the raceway surface; and because the rollers are arranged in an alternating orthogonal manner and are fixed and supported by retainers, the stability and accuracy of the rollers during the rolling process can be ensured.

[0073] Specifically, the cross-roller guide can withstand loads in all directions and transfer the load to the guide frame through the rolling motion of the rollers, thereby achieving stable linear motion; at the same time, due to the large contact area and small elastic deformation between the rollers and the raceway surface, friction and wear can be reduced, thereby improving the service life and stability of the system.

[0074] In summary, the cross roller guide has the advantages of small rolling friction, good stability, large contact area, small elastic deformation, many effective moving bodies, easy to achieve high rigidity, high load movement, flexible structural design, easy installation and use, low mechanical energy consumption, high precision, high speed, large load capacity and long life.

[0075] In the embodiment of the present application, the wedge-shaped lifting component 2, the miniature cross-roller guide (that is, the first cross-roller guide 22 and the second cross-roller guide 24) and the feedback device 4 for obtaining position parameters are combined with each other to form a specific structural design; and, through the above-mentioned specific structural design and the use of a linear motor 3 instead of a traditional rotary motor, compensation for motion errors can be achieved, thereby improving the movement speed and motion accuracy of the lifting platform, and even achieving micron-level motion accuracy, thereby meeting the accuracy and speed requirements of the precision lifting platform 100, and making the precision lifting platform 100 have the advantage of a more compact structure.

[0076] In other words, the precision lifting platform 100 is based on a wedge-propelled lifting platform, which converts the large stroke displacement of the first wedge block 21 in the horizontal direction (that is, the first direction 1001) into a small stroke displacement of the second wedge block 23 in the vertical direction (that is, the second direction 1002) through inclined surface matching, thereby significantly improving the movement accuracy of the small stroke displacement of the second wedge block 23 in the vertical direction (that is, the second direction 1002).

[0077] Combination Figure 1-Figure 5 It can be seen that the first wedge block 21 and the second wedge block 23 in the precision lifting platform 100 use wedge-shaped inclined surfaces to cooperate with each other, so that the table height of the precision lifting platform 100 is relatively low, and further the precision lifting platform 100 can be adjusted with high precision and high stability; and, the precision lifting platform 100 uses a linear motor 3 (for example, a precision linear motor or a high-precision linear motor), which has good movement stability; then, the precision lifting platform 100 uses a linear guide mechanism 25 (for example, a bidirectional high-precision linear guide rail), so that the precision lifting platform 100 has the characteristics of small jitter and small flatness change during the lifting movement in the vertical direction (that is, the second direction 1002); and, the wedge-shaped inclined surfaces cooperate with each other to obtain continuous thrust, thereby realizing the lifting of heavy objects and the smooth operation of larger objects.

[0078] To further explain, the precision lifting platform 100 may also be provided with a load plate (not shown in the figure) installed on the bearing portion 231 , so that the load to be lifted can be placed or installed on the second wedge block 23 .

[0079] In some embodiments, Figure 3-5 As shown, a first angle is formed between the oblique mounting portion 212 and the horizontal mounting portion 211, a second angle is formed between the assembly portion 232 and the bearing portion 231, and the first angle is equal to the second angle; in other words, when the first wedge block 21 and the second wedge block 23 cooperate with each other, the bearing portion 231 and the horizontal mounting portion 211 are parallel to each other.

[0080] In some embodiments, reference Figure 1-Figure 3 It can be known that the platform base 1 includes: a substrate 11 and a pair of support plates 12 .

[0081] It should be noted that the pair of support plates 12 are disposed on two sides of the substrate 11 that are away from each other in the first direction 1001 , and protrude from the surface of the substrate 11 along the second direction 1002 .

[0082] It can be understood that the surface of the base plate 11 and the surfaces of the pair of support plates 12 enclose a receiving space, and the lifting component 2 and the linear motor 3 are both accommodated in the receiving space.

[0083] In some embodiments, according to Figure 1-Figure 3 It can be seen that the first cross roller guides 22 are arranged in pairs on the surface of the substrate 11 and extend along the first direction 1001 .

[0084] Specifically, the second cross roller guide rails 24 are arranged in pairs between the first wedge block 21 and the second wedge block 23 and extend along the third direction.

[0085] In the embodiment of the present application, the third direction is inclined to the first direction 1001 or the second direction 1002, and a preset angle between the third direction and the first direction 1001 is equal to the first angle or the second angle.

[0086] In some embodiments, Figure 3-Figure 5 It can be seen that the first wedge block 21 is provided with a motor mounting slot 210 , and the horizontal mounting portion 211 and the oblique mounting portion 212 are both located outside the motor mounting slot 210 .

[0087] Figure 6 A front cross-sectional view of the precision lifting platform provided in an embodiment of the present invention.

[0088] In some embodiments, please refer to Figure 3 and Figure 6 The linear motor 3 at least includes: a stator component 31 and a mover component 32 .

[0089] The stator component 31 is fixedly mounted on the substrate 11 , the mover component 32 is fixedly connected to the first wedge block 21 , and both the stator component 31 and the mover component 32 are located inside the motor mounting slot 210 .

[0090] In addition, the movable component 32 can move relative to the stator component 31 to drive the first wedge block 21 to reciprocate in the first direction 1001 .

[0091] Generally speaking, a linear motor is a mechanical energy that directly converts electrical energy into linear motion. That is, the linear motion formed by the linear motor does not require any intermediate transmission links. Therefore, the linear motor has the advantages of no wear, no backlash, easy maintenance, high speed, high acceleration and deceleration, high precision, unlimited stroke, high dynamic characteristics, stable speed and multiple movers.

[0092] Specifically, the selection of a linear motor is very different from that of a traditional rotary motor, because a linear motor does not require any intermediate transmission link, so the linear motor can directly push the first wedge block 21 to move in a straight line; therefore, when selecting a linear motor, the following parameters should be given priority: maximum acceleration, maximum speed, rated thrust at constant speed, maximum thrust, etc.

[0093] To further explain, the selection of linear motors includes but is not limited to the following steps:

[0094] (1) Preliminarily select the structural form of the linear motor according to the mechanism form, and calculate the holding force required for constant speed operation according to the load mass, the planned stroke, the movement speed and the movement acceleration;

[0095] (2) Calculate the maximum acceleration force and maximum deceleration force of the linear motor based on the technical data of the linear motor, and then obtain the average continuous output force to preliminarily select a certain model of linear motor;

[0096] (3) Considering the influence of the quality of the moving coil part of the selected linear motor, repeatedly calculate the peak force and average continuous output force of the linear motor to check whether the selected linear motor meets the requirements, and calculate the temperature of the linear motor to check whether the temperature rise of the linear motor meets the requirements.

[0097] Generally speaking, linear motors can be based on Frms ＝ The continuous thrust of the linear motor is calculated by (ML+MP)×g×μ+Ff; then, the peak thrust of the linear motor is calculated according to Famax=(ML+MP)×amax+Frms; finally, the peak thrust and continuous thrust can be obtained by referring to the relevant technical parameters of the mover and stator components.

[0098] Among them, Frms is the continuous force, Famax is the peak force, ML is the mass of the load, MP is the mass of the linear motor's rotor, g is the acceleration due to gravity, μ is the friction coefficient, Ff is other external resistance (for example, air resistance), and amax is the maximum acceleration.

[0099] Specifically, there are three control methods for linear motors: pulse, analog, and communication control. In different application scenarios, linear motors should choose different control methods.

[0100] In some embodiments, see Figure 1-Figure 3 At least one pair of linear guide mechanisms 25 is disposed on two sides of the second wedge block 23 that are away from each other in the first direction 1001 .

[0101] In some embodiments, Figure 1-Figure 3 As shown, the linear guide mechanism 25 includes: a linear guide rail 251 and a slider 252. One of the linear guide rail 251 and the slider 252 is fixedly mounted on the second wedge block 23, and the other is fixedly connected to the support plate 12.

[0102] Specifically, the linear guide rail 251 extends along the second direction 1002 ; the slider 252 is sleeved on the linear guide rail 251 , so that the slider 252 can reciprocate along the second direction 1002 on the linear guide rail 251 .

[0103] In some embodiments, according to Figure 2 and Figure 3 It can be known that the feedback device 4 at least includes: a grating scale (not shown in the figure) and a grating reading head 41.

[0104] It should be noted that the grating scale is attached to the second wedge block 23 , and the grating reading head 41 is connected to the substrate 11 via the reading head fixing block 411 .

[0105] It can be understood that the grating scale can move relative to the grating reading head 41 following the movement of the second wedge block 23 in the second direction 1002.

[0106] Specifically, the grating reading head 41 can cover at least a portion of the grating scale; when the grating scale moves relative to the grating reading head 41, the position parameters of the second wedge block 23 can be obtained in real time.

[0107] In the embodiment of the present application, the reading head fixing block 411 has multiple adjustable degrees of freedom, which can conveniently and quickly adjust the grating reading head 41 and the grating scale to the optimal spatial position to reduce the measurement error caused by the measuring instrument.

[0108] In some embodiments, in combination Figure 1 and Figure 3 It can be seen that the precision lifting platform 100 further includes: a first photoelectric switch 5 , a second photoelectric switch 6 and a shielding plate 7 .

[0109] The first photoelectric switch 5 and the second photoelectric switch 6 are fixed on the substrate 11 , and the first photoelectric switch 5 and the second photoelectric switch 6 are away from each other along the first direction 1001 .

[0110] In addition, the first photoelectric switch 5 is spaced apart from one end of the substrate 11 in the first direction 1001 by a preset distance; the second photoelectric switch 6 is spaced apart from the other end of the substrate 11 in the first direction 1001 by a preset distance.

[0111] In addition, the shielding plate 7 is fixed on the first wedge-shaped block 21 so that the shielding plate 7 can move following the movement of the first wedge-shaped block 21 .

[0112] In some embodiments, Figure 1 and Figure 3 As shown, the first photoelectric switch 5 and the second photoelectric switch 6 can be connected to the movable component 32 via cables, and cooperate with the baffle plate 7 to limit the travel range of the first wedge block 21 in the first direction 1001, thereby preventing the first wedge block 21 from detaching from the first cross roller guide 22.

[0113] In an embodiment of the present application, the first photoelectric switch 5 can be composed of two parallel photoelectric switches. Such a layout can expand the detection range on the side where the first photoelectric switch 5 is located to form a redundant design to increase the safety, stability and reliability of the system, and can also effectively expand the detection area to further cover more potential targets; and the second photoelectric switch 6 can be composed of only one photoelectric switch. Such a layout can reduce the detection cost while ensuring the detection accuracy.

[0114] In some embodiments, please refer to Figure 1-Figure 3 The precision lifting platform 100 also includes: a plurality of anti-collision blocks 8.

[0115] Specifically, a plurality of anti-collision blocks 8 are fixedly mounted on the base plate 11 , and are arranged in pairs at two ends of the first wedge block 21 in the first direction 1001 .

[0116] In the embodiment of the present application, when the shielding plate 7 is located at the position of the first photoelectric switch 5 or the second photoelectric switch 6 , the anti-collision block 8 can produce a buffering effect on the first wedge block 21 .

[0117] Combination Figure 1-Figure 6, the movement principle of the precision lifting platform 100 is described in detail: first, the moving component 32 of the linear motor 3 drives the first wedge block 21 to move in the first direction 1001; then, the first wedge block 21 makes the second wedge block 23 move in the second direction 1002 through the inclined surface cooperation, thereby completing the lifting and lowering movement of the second wedge block 23 well.

[0118] It should be noted that the precision lifting platform 100 adopts the inclined plane cooperation between the second wedge block 23 and the first wedge block 21 to convert the large stroke displacement of the first wedge block 21 in the first direction 1001 into a small stroke displacement of the second wedge block 23 in the second direction 1002; wherein, the large stroke displacement is subdivided into multiples, which can effectively improve the movement accuracy of the second wedge block 23 in the second direction 1002, while also shortening the movement stroke; in addition, the inclined plane cooperation method is adopted to enable the second wedge block 23 to perform the lifting movement in the second direction 1002, which also increases the second wedge block 23 in the second direction The load area in the second direction 1002 increases the load capacity of the second wedge block 23; not only that, the precision lifting platform 100 guides the second wedge block 23 to move in the second direction 1002 through the cooperation between the linear guide mechanism 25 and the second cross roller guide 24, which can constrain the freedom of movement of the first wedge block 21 and the second wedge block 23, thereby ensuring the smooth operation of the precision lifting platform 100, further improving the movement accuracy of the precision lifting platform 100, and reducing the dimensional margin in the second direction 1002, making the structure more compact.

[0119] It is understandable that the detection accuracy of precision detection equipment is often related to the motion accuracy of the precision lifting platform 100. The motion accuracy of the precision lifting platform 100 is not only affected by the manufacturing accuracy and installation accuracy, but also by the component accuracy of each part of the precision lifting platform 100 (for example, the precision lifting platform 100 is also affected by the processing accuracy and assembly error of the cross roller guide mounting surface); moreover, force deformation will also have a great influence on the motion accuracy of the precision lifting platform 100, so it is necessary to analyze and optimize the force deformation of the precision lifting platform 100 in combination with theoretical calculations and the actual working environment of the precision lifting platform 100.

[0120] Generally speaking, motion control algorithm refers to the algorithm of how to control the motion trajectory of a target. The control algorithm is usually built into the motion control system. In actual application, it is necessary to send commands to the motion control system to complete the coordinated motion between the components (for example, controlling the XYZ three-dimensional fixed-point motion). Among them, the common motion control algorithms include interpolation motion and trajectory look-ahead. In addition, the two most common methods of interpolation motion are linear interpolation and circular interpolation. Moreover, interpolation motion requires at least two axes to participate. When performing interpolation motion, the planned axis needs to be mapped to the corresponding machine coordinate system, and then the motion controller controls the motion of each axis according to the coordinate mapping relationship to achieve the preset motion trajectory. Not only that, the interpolation motion instructions will be stored in the motion buffer, and then the instructions will be taken out of the motion buffer in turn for execution until the interpolation motion is completed. In addition, in the actual operation process, continuous interpolation will be enabled in pursuit of operation efficiency, and the motion trajectory If there is no deceleration at the corner, when the corner is large, it will cause a greater impact on the machine tool, thus affecting the running accuracy; in the actual operation process, if the continuous interpolation is turned off and the deceleration at the corner is zero, although the machine is protected, the running efficiency is greatly affected. Therefore, a look-ahead instruction is provided to automatically determine whether to reduce the corner speed to a reasonable value at the corner, which will not affect the running accuracy and can improve the running speed. This is the role of trajectory look-ahead; specifically, the trajectory look-ahead of the motion controller can automatically calculate a smooth speed plan based on the user's motion path, reduce the impact of the machine, and thus improve the running accuracy; generally speaking, it automatically analyzes the turning point that will appear in the instruction trajectory in the motion buffer, and automatically calculates the motion speed at the corner according to the corner conditions set by the user. It also calculates the speed plan according to the maximum acceleration value set by the user, so that the acceleration and deceleration in any acceleration and deceleration process does not exceed ACCEL (Acce The values ​​of acceleration (L) and deceleration (Decelerate) are used to prevent damaging impact forces on mechanical parts. Further explanation: motion control algorithm is an algorithm that uses machine controllers and computer programs to achieve precise control of mechanical systems. It is usually used to control the movement of mechanical systems to obtain the desired performance. In summary, motion control algorithms can make the movement of mechanical systems more accurate, stable, fast, and reliable, and can achieve automatic control. Motion control algorithms can be divided into two categories: motion control and position control.

[0121] Specifically, motion control refers to controlling the speed, acceleration and torque of a mechanical system to achieve the desired goal; while position control refers to controlling the position of a mechanical system to achieve the desired accuracy requirements; in addition, among various motion control algorithms, the most commonly used motion control algorithms include PID (Proportional-Integral-Differential) control and fuzzy control, neural network control, sliding mode control, etc.; among them, PID control is the most commonly used motion control algorithm, which uses feedback signals to control the speed and position of a mechanical system; in addition, fuzzy control uses fuzzy logic to achieve the control of a mechanical system, which can effectively suppress the influence of noise; moreover, neural network control uses neural network technology to achieve the control of a mechanical system, which has strong robustness and adaptability; and sliding mode control uses sliding mode theory to achieve the control of a mechanical control system with strong robustness (Robustness refers to the ability of a system to maintain its performance and functional stability when facing changes in its internal structure and external environment; specifically, a robust system can still operate normally and maintain good performance under the influence of various adverse factors such as interference, noise, and failures).

[0122] Motion control algorithms play an important role in engineering practice. They can effectively control the motion of mechanical systems, thereby improving the performance of mechanical systems and reducing the energy consumption of mechanical systems, and achieving precise control. At the same time, motion control algorithms can also achieve intelligent control of mechanical systems, so that mechanical systems can complete tasks more independently and intelligently.

[0123] Specifically, the control system requires the function of expanding the I / O port (I nput / Output) to control the precision lifting platform 100. At the same time, it can also be driven by position comparison differential output pulses and connected to an electronic subdivision feedback device (that is, a grating scale and a grating reading head) to improve movement accuracy.

[0124] In the embodiment of the present application, the PID algorithm is required to improve the overall efficiency and control accuracy of the precision lifting platform 100; wherein, the PID controller is composed of a proportional unit, an integral unit, and a differential unit; in addition, although it is difficult to achieve motion performance indicators by relying solely on the PID controller in a high-precision and high-acceleration motion system, the performance of the PID controller can be significantly improved by adding targeted compensation, correction and other links, including improving the response speed, motion accuracy, tracking error, etc. of the PID controller.

[0125] It can be understood that the comprehensive control strategy of the PID algorithm combined with the feedforward compensation method is: adding speed feedforward and acceleration feedforward to the control link can better achieve high-precision control.

[0126] It should be noted that during the movement of the precision lifting platform 100, changes in load and changes in vibration, temperature, etc. in the environment will cause disturbances to it, and the control system needs to have strong anti-interference capabilities to ensure that the precision lifting platform 100 can maintain its movement performance under a certain degree of interference; among them, for ultra-precision measuring equipment, the environment itself has strict requirements. The precision lifting platform 100 can be combined with the existing air-floating vibration isolation table to block the vibration of a certain frequency environment, thereby effectively reducing the vibration generated by the outside world to the precision lifting platform 100; in addition, by adding precise natural granite to the shock absorber, the precision lifting platform 100 can eliminate external interference vibrations when running on the shock absorber; then, an adjustable mechanical device is added to the shock absorber, which can meet the requirements of the precision lifting platform 100 when running on the isolation table. Its flatness can be adjusted by the above-mentioned mechanical device, so that the precision lifting platform 100 can operate normally.

[0127] Generally speaking, when measuring the positioning accuracy and axial data of the precision lifting platform 100, it is necessary to obtain multiple parameters including the x-axis (i.e., the coordinate axis that is orthogonal to the y-axis and the z-axis), the y-axis (i.e., the coordinate axis parallel to the first direction 1001), the z-axis (i.e., the coordinate axis parallel to the second direction 1002), the pitch angle, the yaw angle, and the roll angle (for example, speed, acceleration, parallelism, verticality, and flatness errors, etc.); among them, the detection equipment for performing relevant measurements on the precision lifting platform 100 needs to have but is not limited to the following features:

[0128] (1) It has the function of geometric accuracy detection, which can be used to detect straightness, verticality, pitch and yaw, flatness, parallelism, etc.;

[0129] (2) It has the function of detecting position accuracy and its automatic compensation, and can detect the positioning accuracy, repeat positioning accuracy, micro-displacement accuracy, etc. of CNC machine tools; that is, the detection equipment can not only automatically measure the error of the machine, but also automatically compensate its linear error through the interface, and at the same time, it can maximize the number of compensation points on the measured axis to achieve the best accuracy of the platform;

[0130] (3) It can automatically measure any angle position and any angle interval, and provide statistical results processed according to relevant standards;

[0131] (4) Linear errors can be compensated;

[0132] (5) It has dynamic performance detection function, which can realize the dynamic characteristics analysis of linear motor, response characteristics analysis of servo drive system and dynamic characteristics (low-speed creeping) analysis of guide rail, etc.

[0133] (6) It can simultaneously measure linear positioning error, straightness error, yaw angle, pitch angle and roll angle, as well as parameters such as speed, acceleration, vibration, and evaluate the dynamic characteristics of the precision lifting platform 100.

[0134] In summary, the precision lifting platform provided by the embodiment of the present invention adds a first wedge block, a second wedge block, a first cross roller guide, a second cross roller guide and a feedback device to combine the wedge-shaped lifting components, the miniature cross roller guide and the feedback device for obtaining position parameters to form a specific structural design; through the above-mentioned specific structural design and the use of linear motors to replace traditional rotary motors, the compensation of motion errors can be achieved, thereby improving the movement speed and motion accuracy of the lifting platform, and even achieving micron-level motion accuracy, thereby meeting the accuracy and speed requirements of the precision lifting platform, and making the precision lifting platform have the advantage of a more compact structure. The cross roller guide added to the precision lifting platform has the advantages of large contact area and small elastic deformation, so it can achieve high rigidity and high load movement. The precision lifting platform has a long-term market prospect, and its motion accuracy and motion stability are at the forefront of the technology of existing lifting platforms, with great development opportunities and can achieve certain social benefits. Therefore, the precision lifting platform provided by the embodiment of the present invention has a certain novelty compared with the traditional lifting platform.

[0135] The above contents are further detailed descriptions of the present invention in combination with specific / preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention.

Claims

1. A precision lifting platform, comprising: The platform base is characterized in that it also includes: A lifting component; the lifting component comprises: a first wedge block, a first cross roller guide, a second wedge block, a second cross roller guide and at least one pair of linear guide mechanisms; The first wedge block has a horizontal mounting portion and an oblique mounting portion, and the oblique mounting portion is inclined relative to the horizontal mounting portion; a portion of the first cross roller guide is fixedly mounted on the platform base, and another portion is fixedly connected to the horizontal mounting portion to guide the first wedge block to reciprocate in a first direction; The second wedge block has a bearing portion and a mounting portion, and the mounting portion is inclined to the bearing portion; a portion of the second cross roller guide is fixedly mounted on the inclined mounting portion, and another portion is fixedly connected to the mounting portion; a portion of each of the linear guide mechanisms is fixedly mounted on the platform base, and another portion is fixedly connected to the second wedge block; The second wedge block can move along a second direction following the movement of the first wedge block in the first direction under the cooperation of the second cross roller guide and the linear guide mechanism, and the second direction and the first direction are orthogonal to each other; A linear motor; a portion of the linear motor is fixedly mounted on the platform base, and another portion of the linear motor is fixedly connected to the first wedge block to drive the first wedge block to reciprocate in the first direction; Feedback device; the feedback device is installed on the second wedge block and / or the platform base, and is used to obtain the position parameters of the second wedge block.

2. The precision lifting platform according to claim 1, characterized in that: A first angle is formed between the oblique mounting portion and the horizontal mounting portion, a second angle is formed between the assembly portion and the bearing portion, and the first angle is equal to the second angle.

3. The precision lifting platform according to claim 2, characterized in that: The platform base comprises: A substrate and a pair of support plates; the pair of support plates are arranged on two sides of the substrate away from each other in the first direction and protrude from the surface of the substrate along the second direction; The surface of the substrate and the surfaces of the pair of support plates enclose a receiving space, and the lifting component and the linear motor are both accommodated in the receiving space.

4. The precision lifting platform according to claim 3, characterized in that: The first cross roller guides are arranged in pairs on the surface of the substrate and extend along a first direction; The second cross roller guides are arranged in pairs between the first wedge block and the second wedge block and extend along the third direction; The third direction is inclined to the first direction or the second direction, and a preset angle between the third direction and the first direction is equal to the first angle or the second angle.

5. The precision lifting platform according to claim 3, wherein the first wedge block is provided with a motor mounting slot, and the horizontal mounting portion and the oblique mounting portion are both located outside the motor mounting slot; characterized in that: The linear motor at least comprises: A stator component and a mover component; the stator component is fixedly mounted on the substrate, the mover component is fixedly connected to the first wedge block, and both the stator component and the mover component are located inside the motor mounting slot; Wherein, the movable component can move relative to the stator component to drive the first wedge block to reciprocate in the first direction.

6. The precision lifting platform according to claim 3, wherein at least one pair of the linear guide mechanisms are arranged on two sides of the second wedge block that are away from each other in the first direction; characterized in that: The linear guide mechanism comprises: A linear guide rail and a slider, one of which is fixedly mounted on the second wedge block, and the other is fixedly connected to the support plate; Wherein, the linear guide rail extends along the second direction; the slider is sleeved on the linear guide rail, so that the slider can reciprocate along the second direction on the linear guide rail.

7. The precision lifting platform according to claim 3, characterized in that: The feedback device at least comprises: Grating ruler and grating reading head; the grating ruler is attached to the second wedge block, and the grating reading head is connected to the substrate through a reading head fixing block; The grating ruler can move relative to the grating reading head following the movement of the second wedge block in the second direction; The grating reading head can cover at least a portion of the grating ruler; when the grating ruler moves relative to the grating reading head, the position parameters of the second wedge block can be obtained in real time; Wherein, the reading head fixing block has multiple adjustable degrees of freedom.

8. The precision lifting platform according to claim 5, characterized in that: Also includes: A first photoelectric switch, a second photoelectric switch and a shielding plate; The first photoelectric switch and the second photoelectric switch are fixed on the substrate, and the first photoelectric switch and the second photoelectric switch are away from each other along the first direction; The first photoelectric switch is spaced apart from one end of the substrate in the first direction by a preset distance; the second photoelectric switch is spaced apart from the other end of the substrate in the first direction by a preset distance; The shielding plate is fixed on the first wedge-shaped block so that the shielding plate can move following the movement of the first wedge-shaped block.

9. The precision lifting platform according to claim 8, characterized in that: The first photoelectric switch and the second photoelectric switch can be connected to the movable component via cables, and cooperate with the shielding plate to limit the travel range of the first wedge block moving in the first direction.

10. The precision lifting platform according to claim 8, characterized in that: Also includes: A plurality of anti-collision blocks; the plurality of anti-collision blocks are fixedly mounted on the base plate and are arranged in pairs at both ends of the first wedge-shaped block in the first direction; Wherein, when the shielding plate is located at the position of the first photoelectric switch or the second photoelectric switch, the anti-collision block can produce a buffering effect on the first wedge-shaped block.

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