Large-stroke displacement table

Abstract

The invention discloses a large-stroke displacement table which comprises a base, a table body structure movably arranged on the base, a jacking block movably connected with the table body structure and a driving mechanism arranged opposite to the jacking block, and the jacking block is driven by the driving mechanism to push the table body structure to ascend or descend. According to the scheme, the motor is adopted to drive the precise ball screw movement system to achieve large-stroke movement of the platform body structure, the platform body structure adopts the precise grating ruler as feedback of the ball screw movement system, and it can be ensured that the large-stroke movement positioning precision of the platform body structure reaches the micron dimension. And meanwhile, a corresponding piezoelectric nano actuator is matched to carry out distance adjustment, so that nano-scale accurate positioning is realized. And the two motion systems can compensate each other to make up the shortages of each other, so that not only can the requirement of a large-stroke movement range be met, but also the nano-scale precision positioning requirement can be met.

Description

Technical Field

[0001] The present invention relates to the field of frustum structures, and more specifically, to a large-stroke displacement stage. Background Art

[0002] With the continuous progress of technology, precision nano-positioning technology has become an important foundation in many high-tech fields such as nano-processing, biomedicine, and materials science. This technology involves multiple basic disciplines such as microelectronics, optics, mechanics, control theory, information technology, and software engineering. With the continuous progress of science and technology, the requirements for the stroke range of nano-level positioning frustum structures are also constantly increasing.

[0003] Nano-level positioning frustum structures generally adopt piezoelectric ceramic drive technology to achieve micro-nano-level precise displacement using the piezoelectric effect. However, its shortcomings are extremely obvious. Piezoelectric ceramic drive technology can achieve extremely high displacement resolution, up to the nano-level. However, its maximum stroke is relatively small, generally in the sub-millimeter range, making it difficult to meet the usage scenarios that require large-stroke nano-level positioning. This shortcoming greatly limits the application scope of piezoelectric ceramic drive technology. Summary of the Invention

[0004] The purpose of the present invention is to provide a large-stroke displacement stage to solve the technical problems existing in the above background art.

[0005] The technical solution of the present invention provides a large-stroke displacement stage, including a base, a frustum structure movably arranged on the base, a lifting block movably connected to the frustum structure, and a driving mechanism oppositely arranged with the lifting block. The lifting block pushes the frustum structure to rise or fall under the drive of the driving mechanism;

[0006] The bottom of the frustum structure has a first wedge surface, and the top of the lifting block has a second wedge surface, and the first wedge surface and the second wedge surface are mutually attached;

[0007] The driving mechanism includes a first driving member and a second driving member arranged on the first driving member. The second driving member is opposite to the lifting block. The precision of the second driving member is higher than that of the first driving member, and the displacement of the first driving member is measured by a grating ranging component.

[0008] In a preferred embodiment, a lifting guide rail is arranged on one side of the base, and a wedge guide rail is arranged on the first wedge surface of the frustum structure. The frustum structure is slidably connected to the base and the lifting block through the lifting guide rail and the wedge guide rail respectively;

[0009] A lifting guide rail is also arranged on the base, and the lifting block is slidably connected to the base through the lifting guide rail.

[0010] In a preferred embodiment, pre-tightening springs are arranged on both sides of the table structure, and two ends of each pre-tightening spring are movably connected to the table structure and the base respectively.

[0011] In a preferred embodiment, the pre-tightening springs are arranged obliquely and in a stretched state.

[0012] In a preferred embodiment, the first driving member includes a driving motor, a ball screw connected to an output end of the driving motor, a screw nut adapted to the ball screw, and a moving seat connected to the screw nut. The driving motor is mounted on the base through a motor mounting seat.

[0013] In a preferred embodiment, the second driving member is mounted on the moving seat. A driving guide rail is arranged on the base, and the moving seat is slidably connected to the base through the driving guide rail.

[0014] In a preferred embodiment, the second driving member includes a piezoelectric actuator arranged on the moving seat, and a pushing head in contact with the jacking block is arranged at an output end of the piezoelectric actuator.

[0015] In a preferred embodiment, the grating ranging assembly includes a grating scale arranged on the base and a grating reading head arranged on the jacking block.

[0016] In a preferred embodiment, the feedback accuracy of the grating ranging assembly is 100 nm.

[0017] The beneficial effects of the technical solution of the present invention are as follows:

[0018] As a whole, this solution adopts a motor-driven precision ball screw motion system to realize the large-stroke movement of the table structure. The table structure uses a precision grating scale as the feedback of the ball screw motion system, which can ensure that the motion positioning accuracy of the table structure with a large stroke reaches the micron level. At the same time, a corresponding piezoelectric nano-actuator is configured for distance adjustment to achieve nanometer-level precise positioning. The two motion systems can compensate for each other to make up for each other's shortcomings, which can not only meet the requirements of a large stroke movement range but also take into account the precise positioning requirements at the nanometer level. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic diagram of the overall structure of the present invention,

[0020] Figure 2 is a schematic diagram of the overall structure of the present invention from a top view perspective,

[0021] Figure 3 is a schematic diagram of the overall structure of the present invention from a side view perspective,

[0022] Figure 4This is the control block diagram of the hardware system of the present invention.

[0023] Figure 5 This is the application flow chart of the present invention.

[0024] Description of reference numerals: 1 base, 2 table body structure, 3 lifting block, 4 lifting guide rail, 5 wedge guide rail, 6 lifting guide rail, 7 pre-tightening spring, 8 driving motor, 9 mounting seat, 10 ball screw, 11 moving seat, 12 driving guide rail, 13 piezoelectric actuator, 14 pushing head, 15 grating scale, 16 grating reading head. Detailed implementation manners

[0025] The present invention will be further described in detail below. The embodiments of the present invention are given for the convenience of illustration and description, and are not exhaustive or limited to the disclosed form. Many modifications and variations are obvious to those of ordinary skill in the art. The embodiments are selected and described to better illustrate the principles and practical applications of the present invention, and enable those of ordinary skill in the art to understand the present invention and thus design various embodiments with various modifications suitable for specific purposes.

[0026] As Figures 1 - 3 shown, the technical solution of the present invention provides a large-stroke displacement stage 2, including a base 1, a table body structure 2 movably arranged on the base 1, a lifting block 3 movably connected to the table body structure 2, and a driving mechanism oppositely arranged with the lifting block 3. The lifting block 3 drives the table body structure 2 to rise or fall under the drive of the driving mechanism. In use, corresponding devices and components are installed on the table body structure 2, and the lifting block 3 and the driving mechanism cooperate with each other to enable the table body structure 2 to achieve high-precision displacement.

[0027] The bottom of the table body structure 2 has a first wedge surface, and the top of the lifting block 3 has a second wedge surface, and the first wedge surface and the second wedge surface are mutually attached. One side of the base 1 is provided with a lifting guide rail 4, and a wedge guide rail 5 is provided on the first wedge surface of the table body structure 2. The table body structure 2 is respectively slidably connected to the base 1 and the lifting block 3 through the lifting guide rail 4 and the wedge guide rail 5; a lifting guide rail 6 is further provided on the base 1, and the lifting block 3 is slidably connected to the base 1 through the lifting guide rail 6.

[0028] In the above solution, the lifting block 3 is located below the table structure 2. When performing the ascending movement, the driving mechanism drives the lifting block 3 to move at the bottom of the table structure 2. Since the connecting surfaces of the two are wedge-shaped surfaces and are connected by a wedge-shaped guide rail 5, the lifting block 3 will lift the table structure 2. At the same time, it is limited by the lifting guide rail 4, and the table structure 2 can rise in a straight line. The movement of the lifting block 3 is limited by the lifting guide rail 6. The existence of multiple limiting guide rails ensures the transmission of power from the lifting block 3 to the table structure 2, enabling the table structure 2 to rise stably and ensuring the stable operation of the relevant equipment and components installed on the tabletop of the table structure 2.

[0029] Pre-tightening springs 7 are arranged on both sides of the table structure 2. Both ends of the pre-tightening spring 7 are movably connected to the table structure 2 and the base 1 respectively. The pre-tightening spring 7 is inclined and is in a stretched state. The pre-tightening spring 7 adopts a tension spring structure. When the table structure 2 is not lifted, the pre-tightening spring 7 is in a stretched state. When the driving mechanism cancels the driving of the lifting block 3, the pre-tightening spring 7 can pull the table structure 2 to move downward, and the lifting block 3 moves synchronously. The descent of the table structure 2 is realized by setting the pre-tightening spring 7. The mechanical structure transmission is adopted, which is simple in structure, does not require the aid of electric equipment, and reduces costs.

[0030] The driving mechanism includes a first driving part and a second driving part arranged on the first driving part. The second driving part faces the lifting block 3, and the precision of the second driving part is higher than that of the first driving part. The first driving part can realize the movement of the table structure 2 with a large stroke. After the first driving part drives with a relatively large stroke, the second driving part can perform a more refined distance adjustment, making the displacement of the table structure 2 more accurate.

[0031] The first driving part includes a driving motor 8, a ball screw 10 connected to an output end of the driving motor 8, a screw nut adapted to the ball screw 10, and a moving seat 11 connected to the screw nut. The driving motor 8 is installed on the base 1 through a motor mounting seat 9. The second driving part is installed on the moving seat 11. A driving guide rail 12 is arranged on the base 1, and the moving seat 11 is slidably connected to the base 1 through the driving guide rail 12.

[0032] In the above solution, when the driving motor 8 operates, it drives the ball screw 10 to rotate, and then the moving seat 11 moves on the base 1. The first driving member is installed on the moving seat 11, and thus can drive the second driving member to move synchronously. The second driving member faces the lifting block 3, and thus can push the lifting block 3 to move synchronously, realizing the lifting of the table structure 2. The displacement of the first driving member is measured by the grating ranging component. The grating ranging component includes a grating scale 15 arranged on the base 1 and a grating reading head 16 arranged on the lifting block 3. The feedback accuracy of the grating ranging component is 100 nm. During the process of the lifting block 3 being driven to move, the grating reading head 16 arranged on the side of the lifting block 3 reads the position of the grating scale 15 to achieve positioning, ensuring that the motion positioning accuracy of the table structure 2 with a large stroke reaches the micron level.

[0033] The second driving member includes a piezoelectric actuator 13 arranged on the moving seat 11, and a pushing head 14 in contact with the lifting block 3 is arranged at the output end of the piezoelectric actuator 13. After the driving with a large stroke is completed, the system needs to perform a more precise positioning motion. At this time, the piezoelectric actuator 13 is used to drive the lifting block 3 to adjust the distance, realizing precise positioning at the nanometer level. The piezoelectric actuator 13 itself is equipped with a capacitive nanometer displacement sensor, and its resolution is at the nanometer level, which can ensure accurate micro-nano motion positioning.

[0034] As Figure 4 shown, during the driving processes of the first driving member and the second driving member, the control system adopts corresponding execution steps. The AC power supply supplies power to the motion controller of the piezoelectric actuator 13 and the motor controller of the ball screw 10 of the table structure 2 through a filter and a 24V DC power supply module. After the control computer issues corresponding motion commands to the communication module through the control software, the communication module will send them to the corresponding motion controller according to the requirements of the commands.

[0035] If it is necessary to control the motion of the piezoelectric actuator 13, the motion controller of the piezoelectric actuator 13 will convert the corresponding commands into corresponding digital signals, convert them into analog signals through the D / A conversion module, and then give them to the piezoelectric actuator 13 through the signal filtering and signal comparison and amplification modules to indirectly drive the table structure 2 to move. After the motion is completed, the capacitive nanometer displacement sensor of the system will give a feedback analog signal. This analog signal is transmitted to the motion controller of the piezoelectric actuator 13 after passing through the A / D conversion and signal comparison and amplification modules. The controller can analyze the actual displacement of the table structure 2 through this feedback signal, and then perform comparison and compensation correction, so as to achieve the corresponding closed-loop control.

[0036] If it is necessary to control the movement of the ball screw 10 motor, the control system will be relatively simple. The ball screw 10 motor controller will convert the corresponding instructions into corresponding signals to drive the motor 8 to rotate and drive the ball screw 10 to move in a straight line. After the movement is completed, the grating reader 16 will read the feedback signal of the grating scale 15, and the signal will be fed back to the ball screw 10 motor controller. The controller can analyze the actual displacement of the platform structure 2 through the feedback signal. After comparison, the controller will perform displacement compensation correction to achieve corresponding closed-loop control.

[0037] like Figure 5 As shown, in actual application, after the process starts, the system software sends a large stroke positioning instruction to the ball screw motor controller, and the motor controller converts it into a corresponding control signal to control the drive motor 8 to rotate. Under the restriction of the drive guide rail 12, the ball screw 10 drives the piezoelectric actuator 13 to move linearly through the moving seat 11. At this time, the piezoelectric actuator 13 drives the lifting block 3 to move linearly at the same time. Under the restriction of the lifting guide rail 4 and the wedge guide rail 5, the table structure 2 performs the corresponding lifting action. At the same time, the position of the grating ruler 15 is read by the grating reader 16 to provide the controller with a corresponding feedback signal. Through signal analysis, a closed-loop position compensation value is provided, which can achieve micron-level positioning accuracy.

[0038] After the large stroke positioning is completed, the system software issues a nano positioning instruction, which is received by the piezoelectric nano actuator and converted into a corresponding control signal. Through a series of signal processing, it is sent to the piezoelectric actuator 13 to perform the corresponding telescopic linear motion. Similarly, the piezoelectric actuator 13 drives the wedge-shaped driving member through the front push head 14 to perform linear motion at the same time. Under the restrictions of the lifting guide rail 4 and the wedge-shaped guide rail 5, the table structure 2 performs the corresponding lifting action. At the same time, the capacitive nano displacement sensor of the piezoelectric actuator 13 will provide the corresponding displacement feedback information to the controller, and through signal analysis, it will provide a closed-loop position compensation value to achieve nano-level positioning requirements.

[0039] Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field and related fields without creative work should fall within the scope of protection of the present invention. The structures, devices and operating methods not specifically described and explained in the present invention are implemented according to the conventional means in the field unless otherwise specified and limited.

Claims

1. A long-stroke translation stage, characterized in that: It comprises a base, a platform structure movably arranged on the base, a lifting block movably connected to the platform structure, and a driving mechanism arranged opposite to the lifting block, wherein the lifting block drives the platform structure to rise or fall under the drive of the driving mechanism; The bottom of the platform structure has a wedge-shaped surface 1, and the top of the lifting block has a wedge-shaped surface 2, and the wedge-shaped surface 1 and the wedge-shaped surface 2 are in contact with each other; The driving mechanism includes a driving member 1 and a driving member 2 arranged on the driving member 1, the driving member 2 is opposite to the lifting block, the accuracy of the driving member 2 is higher than the accuracy of the driving member 1, and the displacement of the driving member 1 is measured by a grating distance measurement component.

2. A long-stroke translation stage according to claim 1, characterized in that: A lifting guide rail is provided on one side of the base, a wedge-shaped guide rail is provided on one wedge-shaped surface of the platform structure, and the platform structure is slidably connected with the base and the lifting block through the lifting guide rail and the wedge-shaped guide rail respectively; The base is also provided with a lifting guide rail, and the lifting block is slidably connected with the base via the lifting guide rail.

3. The long-stroke translation stage according to claim 1, characterized in that: Preload springs are arranged on both sides of the platform structure, and two ends of the preload springs are movably connected to the platform structure and the base respectively.

4. A long-stroke translation stage according to claim 3, characterized in that: The preload spring is arranged obliquely and is in a stretched state.

5. The long-stroke translation stage according to claim 1, characterized in that: The driving component 1 includes a driving motor, a ball screw connected to the output end of the driving motor 1, a screw nut adapted to the ball screw and a moving seat connected to the screw nut. The driving motor is installed on the base through a motor mounting seat.

6. The long-stroke translation stage according to claim 5, characterized in that: The second driving member is installed on the moving seat, a driving guide rail is arranged on the base, and the moving seat is slidably connected with the base through the driving guide rail.

7. The long-stroke translation stage according to claim 5, characterized in that: The second driving member comprises a piezoelectric actuator arranged on the moving seat, and the output end of the piezoelectric actuator is provided with a pushing head in contact with the lifting block.

8. The long-stroke translation stage according to claim 1, characterized in that: The grating distance measuring component is provided with a grating ruler on the base and a grating reader on the lifting block.

9. The long-stroke translation stage according to claim 8, characterized in that: The feedback accuracy of the grating distance measurement component is 100nm.

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