CN117555106B - Large stroke and high precision micro-displacement actuator - Google Patents

Abstract

The invention relates to the field of aerospace remote sensing technology, and in particular to a large-stroke and high-precision micro-displacement actuator, which includes a first base assembly, a large-stroke mechanism, a micro-displacement actuator and a second base assembly; the large-stroke mechanism includes a ball wire rod, reduction box and gap-eliminating structure. The ball screw and the reduction box cooperate to make the reduction box move linearly along the ball screw; the micro-displacement actuating mechanism includes a linear motion component, a first-level amplification mechanism and a second-level amplification mechanism; linear motion The motion component is fixed vertically on the reduction box, the bottom end of the first-level amplification mechanism is fixed on the linear motion component, and the top of the first-level amplification mechanism is connected to the second-level amplification mechanism, so that the first-level amplification mechanism is driven by the linear motion component. It drives the secondary amplification mechanism to adjust movements in different directions, and jointly converts the adjustment movements into adjustments in the vertical direction. Through the multi-stage zoom mechanism, large strokes and nanometer-level movement accuracy can be achieved.

Description

Large stroke and high precision micro-displacement actuator

Technical Field

The invention relates to the field of aerospace remote sensing technology, and in particular to a large-stroke and high-precision micro-displacement actuator.

Background technique

With the development of technology, the requirements for the diameter of the main reflector of telescopes are getting larger and larger. Due to various factors, the single reflector cannot meet the requirements. On the one hand, the diameter of the space telescope is limited by the diameter of the launch vehicle; on the other hand, the diameter of the space telescope is limited by the diameter of the launch vehicle. , limited by current manufacturing capabilities; a spliced reflector composed of multiple sub-mirrors has been proposed to solve the above problems well. The spliced reflector can not only achieve the folding function to meet the space requirements of the launch vehicle, but also has a smaller sub-mirror diameter. The small size makes the preparation of mirrors less difficult. But the problem that comes with it is how to adjust the correct posture of the sub-mirror to ensure the optical performance of the mirror. Micro-displacement drive technology, as a key technology for spliced mirrors, can solve this problem. Generally, the posture of the sub-mirror is completed through a high-precision micro-displacement actuator. Adjustment. In order to achieve high-precision splicing of sub-mirrors, the micro-displacement actuator is generally required to achieve nanometer-level adjustment accuracy, and there is also a need for large-stroke adjustment.

Contents of the invention

In order to solve the above problems, the present invention provides a large-stroke and high-precision micro-displacement actuator device, which has the functions of large-stroke and high-precision movement at the same time. The multi-stage scaling mechanism can be used to achieve large strokes and nano-level motion accuracy, and the gap elimination structure is designed to eliminate the gaps in the large stroke mechanism.

The large-stroke and high-precision micro-displacement actuating device provided by the present invention includes a first base component, a large-stroke mechanism, a micro-displacement actuating mechanism and a second base component; the micro-displacement actuating mechanism is fixed on the large-stroke mechanism through screws. The large-stroke mechanism drives the micro-displacement actuating mechanism for micro-displacement adjustment; the first base component is fixed on the large-stroke mechanism at one end away from the micro-displacement actuating mechanism through screws; the second base component is fixed on the micro-displacement actuating mechanism through screws One end away from the large-stroke mechanism; where the large-stroke mechanism includes a ball screw, a reduction box and a backlash-eliminating structure; one end of the ball screw is connected to the first base component through the backlash-eliminating structure, and the other end of the ball screw is connected through a preload nut Fixed on the top of the reduction box set, the ball screw cooperates with the reduction box to make the reduction box move linearly along the ball screw; the micro-displacement actuating mechanism includes a linear motion component, a first-level amplification mechanism and a second-level amplification mechanism; the linear motion component is vertical Fixed on the reduction box, the second-level amplification mechanism is a symmetrical square door structure. The bottom end of the second-level amplification mechanism is connected to the gap-eliminating structure through screws. The second base component is fixed on the top of the second-level amplification mechanism through screws; the first-level amplification mechanism The mechanism is a symmetrical trapezoidal door structure. The bottom end of the first-level amplification mechanism is fixed on the linear motion component. The top of the first-level amplification mechanism is connected to the second-level amplification mechanism, so that the first-level amplification mechanism is driven by the linear motion component and drives the second-level amplification mechanism. The amplification mechanism completes micro-displacement adjustment.

Further, the reduction box includes a reduction box body, a stepper motor, a worm gear, a worm, a bearing and a preload nut. Among them, the reduction box body is a hollow cylinder structure with a mounting platform. The bearings are embedded in the top and bottom plates of the reduction box, so that the ball screw passes through the reduction box through the bearings and is fixed in the top plate of the reduction box through the preload nut. The worm gear is embedded in the reduction box along the tangential direction and is located between the two bearings. The stepper motor is fixed on the outer wall of the reduction box, and the worm in the stepper motor passes through the side wall of the reduction box to mesh with the worm gear. The stepper motor drives the worm, so that the worm wheel and the worm cooperate to realize the deceleration adjustment of the reduction box.

Further, the first-level amplification mechanism includes a first-level amplification top plate and two first-level amplification support arms. The first-level amplification support arms support the first-level amplification top plate through flexible hinges. The first-level amplification support arm includes a first-level amplification side plate and a first-level amplification bottom. The first-level amplification side plate and the first-level amplification bottom plate are connected through a flexible hinge. The first-level amplification base plate is connected to the linear motion component through screws, so that the linear motion component drives the first-level amplification. The enlarging base plate moves linearly, and the first-level enlarging top plate is pulled by the flexible hinge to move longitudinally.

Further, the second-level amplification mechanism includes a second-level amplification top plate, a second-level amplification support arm, a second-level amplification connecting plate and a second-level amplification connecting arm; wherein, the number of the second-level amplifying support arms and the second-level amplifying connecting arms is two. , the secondary amplification support arm is connected to the secondary amplification top plate through a flexible hinge, so that the secondary amplification support arm supports the secondary amplification top plate;

The secondary amplification support arm includes a secondary amplification base, a secondary amplification lower arm, a secondary amplification connecting block and a secondary amplification upper arm; one end of the secondary amplification upper arm and the secondary amplification lower arm is connected to the secondary amplification connecting block through a flexible hinge , the other end of the upper arm of the second-level amplification is connected to the top plate of the second-level amplification through a flexible hinge; the other end of the lower arm of the second-level amplification is connected to the base of the second-level amplification through a flexible hinge; the base of the second-level amplification is fixed on the top plate of the reduction box through screws ;

One end of the secondary amplification connecting arm is connected to the secondary amplification connecting plate through a flexible hinge, and the other end of the secondary amplification connecting arm is connected to the secondary amplification connecting block on the same side through a screw, so that the secondary amplification connecting arm installs the secondary amplification connecting plate below the secondary amplification top plate;

The second-level amplification connecting plate is connected to the first-level amplifying top plate through screws, so that the first-level amplifying top plate drives the second-level amplifying connecting plate to move longitudinally, and then the second-level amplifying top plate is pulled by the flexible hinge to move longitudinally.

Furthermore, the gap eliminating structure is a symmetrical structure, including a fixed seat, a gap eliminating sheet, a gap eliminating support arm and a gap eliminating base plate; wherein, the number of the fixed seat and the gap eliminating support arm are two, and the fixed seat and one end of the gap eliminating support arm are connected by a flexible hinge, and the other end of the gap eliminating support arm is fixed on the gap eliminating base plate; the gap eliminating sheet is fixed at the center of the gap eliminating base plate; the fixed seat corresponds to the secondary amplifying base, and is fixed to the bottom of the top plate of the reduction gear box body by screws.

Further, the structures of the first base component and the second base component are consistent, and both include a base and a cross flexible hinge; wherein the cross flexible hinge is connected to the base through screws; the cross flexible hinge in the first base component is connected to the gap-eliminating sheet, The cross flexible hinge in the second base assembly is connected to the secondary amplification top plate through screws.

Compared with the existing technology, the present invention can achieve the following beneficial effects:

1) The present invention adopts a multi-level scaling mechanism to achieve large stroke and nanometer-level motion accuracy;

2) The different adjustment directions in the first-level amplification mechanism and the second-level amplification mechanism are jointly converted into vertical adjustment;

3) Design the clearance elimination structure to eliminate the clearance of the large stroke mechanism.

Description of drawings

FIG1 is a front view of a large-stroke and high-precision micro-displacement actuating device according to an embodiment of the present invention;

Figure 2 is a cross-sectional view of a large-stroke, high-precision micro-displacement actuator provided according to an embodiment of the present invention;

Figure 3 is a cross-sectional structural view of a reduction gearbox provided according to an embodiment of the present invention;

Figure 4 is an external structural diagram of a reduction gearbox provided according to an embodiment of the present invention;

FIG5 is a schematic structural diagram of a primary amplification mechanism provided according to an embodiment of the present invention;

Figure 6 is a schematic structural diagram of a two-stage amplification mechanism provided according to an embodiment of the present invention;

FIG7 is a schematic structural diagram of a gap elimination structure provided according to an embodiment of the present invention;

FIG. 8 is a schematic diagram of the principle of a large-stroke and high-precision micro-displacement actuator provided according to an embodiment of the present invention.

Reference signs: base 1, cross flexible hinge 2, ball screw 3, reduction box 4, stepper motor 5, worm gear 6, worm 7, bearing 8, preload nut 9, linear motion component 10, first-level amplification mechanism 11. The first-level amplification top plate 11_1, the first-level amplification side plate 11_2, the first-level amplification bottom plate 11_3, the second-level amplification mechanism 12, the second-level amplification top plate 12_1, the second-level amplification connection plate 12_2, the second-level amplification upper arm 12_3, and the second-level amplification connection Block 12_4, secondary amplification lower arm 12_5, secondary amplification base 12_6, secondary amplification connecting arm 12_7, gap elimination structure 13, fixed seat 13_1, gap elimination support arm 13_2, gap elimination sheet 13_3, gap elimination bottom plate 13_4, flexible hinge 14. Turn hinge 15.

Detailed ways

In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention and do not constitute limitations of the present invention.

The large-stroke and high-precision micro-displacement actuator provided by the present invention has the functions of large-stroke and high-precision motion. The device adopts a multi-stage zoom mechanism to convert the adjustment in different directions into a longitudinal single-direction adjustment, which can achieve a large stroke and nanometer-level motion accuracy, and a clearance elimination structure is designed to eliminate the clearance of the large-stroke mechanism.

Figures 1 and 2 respectively show the front structure and cross-sectional structure of a large-stroke, high-precision micro-displacement actuator provided according to an embodiment of the present invention.

As shown in Figures 1 and 2, the large-stroke and high-precision micro-displacement actuating device provided by the embodiment of the present invention includes a first base component, a large-stroke mechanism, a micro-displacement actuating mechanism and a second base component. The micro-displacement actuating mechanism is fixed on the large-stroke mechanism through screws, so that the large-stroke mechanism drives the micro-displacement actuating mechanism for micro-displacement adjustment; the first base component is fixed on the large-stroke mechanism through screws at one end away from the micro-displacement actuating mechanism; The second base assembly is fixed on an end of the micro-displacement actuating mechanism away from the large-stroke mechanism through screws.

Among them, the first base component and the second base component have the same structure, and both include a base 1 and a cross flexible hinge 2 .

The long-stroke mechanism includes a ball screw 3, a reduction box and a clearance elimination structure 13. One end of the ball screw 3 is connected to the first base assembly through the clearance elimination structure 13, and the other end of the ball screw 3 is fixed to the top of the reduction box set through a pre-tightening nut 9. The ball screw 3 cooperates with the reduction box to make the reduction box move linearly along the ball screw 3.

Figures 3 and 4 respectively show the cross-sectional structure and external structure of the reduction gearbox provided according to the embodiment of the present invention.

As shown in Figure 3, the reduction box includes a reduction box body 4, a stepper motor 5, a worm gear 6, a worm 7, a bearing 8 and a preload nut 9. Among them, the deceleration box 4 is a hollow cylindrical structure with a mounting platform. The bearing 8 is embedded in the top and bottom plates of the reduction box 4 so that the ball screw 3 passes through the reduction box 4 through the bearing 8 and is fixed in the top plate of the reduction box 4 through the preload nut 9 . The worm gear 6 is embedded in the reduction box 4 along the tangential direction and is located between the two bearings 8 .

As shown in Figures 3 and 4, the stepper motor 5 is fixed on the outer wall of the reduction box 4, and the worm 7 in the stepper motor 5 passes through the side wall of the reduction box 4 to engage with the worm gear 6. The stepper motor 5 drives the worm 7 so that the worm gear 6 and the worm 7 cooperate to realize the deceleration adjustment of the reduction box.

As shown in Figure 2, the micro-displacement actuator mechanism includes a linear motion component 10, a first-level amplification mechanism 11 and a second-level amplification mechanism 12; the linear motion component 10 is vertically fixed on the installation platform of the deceleration box 4, and the second-level amplification mechanism 12 It is a symmetrical square door structure. The bottom end of the secondary amplifier mechanism 12 is connected to the gap elimination structure 13 through screws. The second base assembly is fixed on the top of the secondary amplifier mechanism 12 through screws. The primary amplifier 11 is structured as a symmetrical trapezoid. Door structure, the bottom end of the first-level amplification mechanism 11 is fixed on the linear motion assembly 10, and the top end of the first-level amplification mechanism 11 is connected to the second-level amplification mechanism 12, so that the first-level amplification mechanism 11 is driven by the linear motion assembly 10 to drive the second-level amplification mechanism 11. The stage amplification mechanism 12 completes micro-displacement adjustment.

FIG. 5 shows the structure of a first-stage amplification mechanism provided according to an embodiment of the present invention.

As shown in FIG. 5 , the first-level amplification mechanism 11 includes a first-level amplification top plate 11_1 and two first-level amplification support arms. The first-level amplification support arms support the first-level amplification top plate 11_1 through a flexible hinge 14 .

The first-level amplification support arm includes a first-level amplification side plate 11_2 and a first-level amplification bottom plate 11_3. The first-level amplification side plate 11_2 and the first-level amplification bottom plate 11_3 are connected through a flexible hinge 14. The first-level amplification bottom plate 11_3 is connected to the linear motion assembly 10 through screws. , so that the linear motion assembly 10 drives the first-level amplification base plate 11_3 to make linear motion, and the first-level amplification top plate 11_1 is pulled by the flexible hinge 14 to move longitudinally.

Figure 6 shows the structure of a two-stage amplification mechanism provided according to an embodiment of the present invention.

As shown in Figure 6, the secondary amplification mechanism 12 includes a secondary amplification top plate 12_1, a secondary amplification support arm, a secondary amplification connecting plate 12_2 and a secondary amplification connecting arm 12_7. Among them, the number of the second-level amplification support arm and the second-level amplification connecting arm 12_7 is two. The second-level amplification support arm is connected to the second-level amplification top plate 12_1 through a flexible hinge 14, so that the second-level amplification support arm connects the second-level amplification top plate 12_1 support.

The second-level amplification support arm includes a second-level amplification upper arm 12_3, a second-level amplification connecting block 12_4, a second-level amplification lower arm 12_5 and a second-level amplification base 12_6; one end of the second-level amplification upper arm 12_3 and the second-level amplification lower arm 12_5 passes through a flexible hinge 14 Connected to the secondary amplification connection block 12_4, the other end of the secondary amplification upper arm 12_3 is connected to the secondary amplification top plate 12_1 through a flexible hinge 14; the other end of the secondary amplification lower arm 12_5 is connected to the secondary amplification base 12_6 through a flexible hinge 14; The secondary amplification base 12_6 is fixed on the top plate of the reduction box 4 through screws.

One end of the secondary amplification connection arm 12_7 is connected to the secondary amplification connection plate 12_2 through a flexible hinge 14, and the other end of the secondary amplification connection arm 12_7 is connected to the secondary amplification connection block 12_4 on the same side through a screw, so that the secondary amplification connection arm 12_7 Install the secondary amplification connecting plate 12_2 under the secondary amplification top plate 12_1.

The second-level amplification connecting plate 12_2 is connected to the first-level amplifying top plate 11_1 through screws, so that the first-level amplifying top plate 11_1 drives the second-level amplifying connecting plate 12_2 to move longitudinally, and then the second-level amplifying top plate 12_1 is pulled by the flexible hinge 14 to move longitudinally.

Figure 7 shows the structure of a gap elimination structure provided according to an embodiment of the present invention.

As shown in Figure 7, the gap-eliminating structure 13 is a symmetrical structure, including a fixed base 13_1, a gap-eliminating support arm 13_2, a gap-eliminating sheet 13_3 and a gap-eliminating base plate 13_4; among which, the number of the fixed base 13_1 and the gap-eliminating support arm 13_2 is Two, and one end of the fixed seat 13_1 and the gap-eliminating support arm 13_2 is connected through a flexible hinge 14, and the other end of the gap-eliminating support arm 13_2 is fixed on the gap-eliminating base plate 13_4; the gap-eliminating sheet 13_3 is fixed on the center of the gap-eliminating base plate 13_4 ; The fixed base 13_1 corresponds to the secondary amplification base 12_6 and is fixed below the top plate of the deceleration box 4 through screws.

The cross flexible hinge 2 is connected to the base 1 through screws; the cross flexible hinge 2 in the first base assembly is connected to the gap elimination sheet 13_3, and the cross flexible hinge 2 in the second base assembly is connected to the secondary amplification top plate 12_1 through screws.

FIG8 shows the principle of a large-stroke, high-precision micro-displacement actuator according to an embodiment of the present invention, wherein FIG8 (a) is a vertical projection of FIG8 (b), and the movement direction of the primary amplifying bottom plate 11_3 is perpendicular to the movement direction of the secondary amplifying top plate 12_1. As shown in FIG8 (a), when the primary amplifying bottom plate 11_3 drives the primary amplifying side plate 11_2 to move from an angle of 11.1 to 11.1 with respect to the central axis, the primary amplifying bottom plate 11_3 moves to the secondary amplifying top plate 12_1. When the position of the first-stage amplifying top plate 11_1 moves toward the center, the second-stage amplifying connecting plate 12_2 moves upward. As shown in FIG8(b), the second-stage amplifying connecting plate 12_2 drives the second-stage amplifying connecting arm 12_7 to move upward. The secondary enlarged connecting block 12_4 is extended outward, so that the secondary enlarged upper arm 12_3 drives the secondary enlarged top plate 12_1 to move downward, and the opening angle of the secondary enlarged upper arm 12_3 is / > Finally, the total scaling ratio of the primary amplification mechanism 11 and the secondary amplification mechanism 12 is .

In the embodiment of the present invention, the step angle of the stepper motor 5 is 1.8°, the reduction ratio of the worm gear 6 and the worm 7 is 1/25, the lead of the ball screw 3 is 2 mm, and the repeat positioning accuracy can reach 2 μm, which enables a large stroke The motion resolution can reach 0.4μm, and the repeated positioning accuracy can reach 2μm.

The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (6)

1. A long-stroke and high-precision micro-displacement actuating device, characterized in that it comprises a first base assembly, a long-stroke mechanism, a micro-displacement actuating mechanism, and a second base assembly; the micro-displacement actuating mechanism is fixed to the long-stroke mechanism by screws, so that the long-stroke mechanism drives the micro-displacement actuating mechanism to perform micro-displacement adjustment; the first base assembly is fixed to the long-stroke mechanism by screws at one end away from the micro-displacement actuating mechanism; the second base assembly is fixed to the micro-displacement actuating mechanism by screws at one end away from the long-stroke mechanism; wherein, The long-stroke mechanism includes a ball screw, a reduction box and a clearance elimination structure; one end of the ball screw is connected to the first base assembly through the clearance elimination structure, and the other end of the ball screw is fixed to the top of the reduction box set through a pre-tightening nut, and the ball screw cooperates with the reduction box to make the reduction box move linearly along the ball screw; The micro-displacement actuating mechanism includes a linear motion component, a first-level amplification mechanism and a second-level amplification mechanism; the linear motion component is vertically fixed on the reduction box, and the second-level amplification mechanism is a symmetrical square door structure, so The bottom end of the second-level amplification mechanism is connected to the gap-eliminating structure through screws, and the second base assembly is fixed on the top of the second-level amplification mechanism through screws; the first-level amplification mechanism is a symmetrical trapezoidal door structure, The bottom end of the first-level amplification mechanism is fixed on the linear motion component, and the top end of the first-level amplification mechanism is connected to the second-level amplification mechanism, so that the first-level amplification mechanism is driven by the linear motion component. The secondary amplification mechanism completes micro-displacement adjustment. 2. The large-stroke and high-precision micro-displacement actuator device according to claim 1, characterized in that the reduction box includes a reduction box, a stepper motor, a worm gear, a worm, a bearing and a preload nut; wherein, The deceleration box is a hollow cylindrical structure with a mounting platform. The bearings are embedded in the top and bottom plates of the deceleration box, so that the ball screw passes through the deceleration box through the bearings and passes through the deceleration box. The preload nut is fixed in the top plate of the reduction box; the worm gear is embedded in the reduction box along the tangential direction and is located between the two bearings; the stepper motor is fixed on the reduction box on the outer wall, and the worm in the stepper motor passes through the side wall of the reduction box to engage with the worm gear. The stepper motor drives the worm, so that the worm gear and the worm cooperate to achieve the desired effect. Describe the deceleration adjustment of the reduction gearbox. 3. The large-stroke and high-precision micro-displacement actuating device according to claim 1 is characterized in that the first-stage amplification mechanism includes a first-stage amplification top plate and two first-stage amplification support arms, and the first-stage amplification support arms support the first-stage amplification top plate through a flexible hinge; the first-stage amplification support arms include a first-stage amplification side plate and a first-stage amplification bottom plate, and the first-stage amplification side plate and the first-stage amplification bottom plate are connected to each other through a flexible hinge, and the first-stage amplification bottom plate is connected to the linear motion component through a screw, so that the linear motion component drives the first-stage amplification bottom plate to perform linear motion, so that the first-stage amplification top plate is pulled by the flexible hinge to perform longitudinal motion. 4. The large-stroke and high-precision micro-displacement actuator device according to claim 3, characterized in that the secondary amplification mechanism includes a secondary amplification top plate, a secondary amplification support arm, a secondary amplification connecting plate and a secondary amplification connecting plate. Amplification connecting arm; wherein, the number of the second-level amplification support arm and the second-level amplification connecting arm is two, and the second-level amplification support arm is connected to the second-level amplification top plate through a flexible hinge, so that the second-level amplification support arm is The secondary amplification support arm supports the secondary amplification top plate; The secondary amplification support arm includes a secondary amplification base, a secondary amplification lower arm, a secondary amplification connecting block and a secondary amplification upper arm; one end of the secondary amplification upper arm and the secondary amplification lower arm is connected to the secondary amplification through a flexible hinge. The secondary amplification connection block is connected, the other end of the secondary amplification upper arm is connected to the secondary amplification top plate through a flexible hinge; the other end of the secondary amplification lower arm is connected to the secondary amplification base through a flexible hinge; The secondary amplification base is fixed on the top plate of the reduction box through screws; One end of the secondary amplifying connecting arm is connected to the secondary amplifying connecting plate through a flexible hinge, and the other end of the secondary amplifying connecting arm is connected to the secondary amplifying connecting block on the same side through a screw, so that the secondary amplifying connecting arm mounts the secondary amplifying connecting plate below the secondary amplifying top plate; The second-level amplification connecting plate is connected to the first-level amplifying top plate through screws, so that the first-level amplifying top plate drives the second-level amplifying connecting plate to move longitudinally, and then the second-level amplifying top plate is supported by the flexible hinge. Traction for longitudinal movement. 5. The large-stroke and high-precision micro-displacement actuator device according to claim 4, characterized in that the gap-eliminating structure is a symmetrical structure, including a fixed seat, a gap-eliminating sheet, a gap-eliminating support arm and a gap-eliminating base plate; Wherein, the number of the fixed seat and the gap-eliminating support arm is two, and one end of the fixed seat and the gap-eliminating support arm is connected through a flexible hinge, and the other end of the gap-eliminating support arm is fixed on On the gap-eliminating bottom plate; the gap-eliminating sheet is fixed at the center of the gap-eliminating bottom plate; the fixing seat corresponds to the secondary amplification base and is fixed below the top plate of the deceleration box through screws. 6. The large-stroke and high-precision micro-displacement actuator device according to claim 5, characterized in that the first base component and the second base component have the same structure, and both include a base and a cross flexible hinge; wherein , the cross flexible hinge is connected to the base through screws; the cross flexible hinge in the first base assembly is connected to the gap elimination sheet, and the cross flexible hinge in the second base assembly is connected to the secondary amplification through screws The top panels are connected.