阅读说明：本技术 一种单相压电驱动的可变光阑装置 (Single-phase piezoelectric driven iris diaphragm device ) 是由 曹腾 李新顺 吴大伟 李晓牛 王伯权 温智益 刘瑞轩 于 2021-07-28 设计创作，主要内容包括：本发明公开了一种单相压电驱动的可变光阑装置,装置包括压电作动器、动圈、遮光片、基座。压电作动器包括压电定子、滚柱、左右固定板、上下导热片、弹簧片、弹簧块；压电定子由单相正弦电压直接驱动,驱动足与动圈滑槽直接接触,通过摩擦效应将驱动足的椭圆运动转换为动圈的转动运动；压电定子侧壁与滚柱直接接触,滚柱、左右固定板、弹簧片、弹簧块对压电定子起到了变形限位作用；动圈与遮光片铰接连接,通过动圈的转动带动遮光片周向转动,从而实现通光孔径的扩大或者收缩；基座上装有两个轴承,起到限位作用；电机端盖与基座通过螺栓连接；本发明减小了光阑的体积,具有结构紧凑、控制简单、响应快、精度高的特点。(The invention discloses a single-phase piezoelectric driven iris diaphragm device which comprises a piezoelectric actuator, a moving coil, a shading sheet and a base. The piezoelectric actuator comprises a piezoelectric stator, a roller, a left fixing plate, a right fixing plate, an upper heat conducting fin, a lower heat conducting fin, a spring piece and a spring block; the piezoelectric stator is directly driven by single-phase sinusoidal voltage, the driving foot is directly contacted with the moving coil chute, and the elliptic motion of the driving foot is converted into the rotating motion of the moving coil through the friction effect; the side wall of the piezoelectric stator is in direct contact with the roller, and the roller, the left and right fixing plates, the spring piece and the spring block play a role in deformation limiting on the piezoelectric stator; the movable coil is hinged with the shading sheet, and the shading sheet is driven to rotate circumferentially by the rotation of the movable coil, so that the light aperture is expanded or contracted; two bearings are arranged on the base to play a role in limiting; the motor end cover is connected with the base through a bolt; the invention reduces the volume of the diaphragm and has the characteristics of compact structure, simple control, quick response and high precision.)

1. The single-phase piezoelectric driven iris diaphragm device is characterized by comprising a base (1), a shading sheet (14), a moving coil (13) and a piezoelectric actuator;

the piezoelectric actuator comprises a piezoelectric stator (7);

the center of the top of the piezoelectric stator (7) is provided with a driving foot (701);

the base (1) comprises an upper half part and a lower half part;

the upper half part of the base (1) is in a ring shape, a circular light through hole is formed in the middle of the base, an annular boss (105) is arranged on the inner ring of the ring, and guide sliding grooves (106) are uniformly distributed on the annular boss (105) and used for limiting the movement of the shading sheet (14); a groove (103) is arranged at the outer ring of the bearing and used for placing the bearing (12), and a vertical shaft (104) is arranged in the middle of the groove (103) and used for fixing the bearing (12); the bearing (12) in the groove (103) and the piezoelectric stator driving foot (701) jointly limit the freedom degree of the moving coil (13); the vertical shaft (104) and the bearing (12) are in interference fit;

the lower half part of the base (1) is provided with a piezoelectric actuator fixing groove (102); the piezoelectric actuator fixing groove (102) is used for placing a piezoelectric stator (7);

the movable coil (13) is annular, and the middle of the movable coil is provided with a light through hole which is coaxial with the light through hole of the base (1); through holes (1302) are uniformly formed in the circumferential direction of the upper end face of the moving coil (13);

the side wall of the moving coil (13) is circumferentially provided with a U-shaped ring groove (1303), the bottom surface of the U-shaped ring groove (1303) is tightly contacted with the bearing (12), the bearing (12) slides freely in the U-shaped ring groove (1303), and the bearing and the piezoelectric stator driving foot (701) play a limiting role on the moving coil together, so that the moving coil (13) only keeps the rotational freedom degree;

the driving feet (701) are in close contact with the bottom surface of the U-shaped ring groove (1303) of the moving coil, so that driving and positioning effects are achieved;

the shading sheet (14) is of an annular fan-shaped sheet structure, a hinged cylinder (1402) is arranged on the upper end face of one end of the shading sheet, and a sliding block cylinder (1401) is arranged on the lower end face of the other end of the shading sheet; the hinged cylinder (1402) on the upper end surface of the light shielding sheet (14) is hinged with the corresponding through hole (1302) on the moving coil (13), and the sliding block cylinder (1401) on the lower end surface is matched with the corresponding guide sliding groove (106) of the base (1), so that the light shielding sheet (14) can rotate in the circumferential direction.

2. The single-phase piezoelectric-driven iris apparatus according to claim 1, wherein the piezoelectric actuator further includes a left fixed plate (2) and a right fixed plate (8);

the left fixing plate (2) is placed in the piezoelectric actuator fixing groove (102) and is arranged on the left side of the piezoelectric stator (7); the right fixing plate (8) is placed in the piezoelectric actuator fixing groove (102) and is arranged on the right side of the piezoelectric stator (7); the left fixing plate (2) and the right fixing plate (8) are used for limiting the position of the piezoelectric stator (7).

3. The single-phase piezoelectric-driven iris apparatus according to claim 2, wherein the left fixing plate (2) is provided with a left roller groove (201), and the right fixing plate (8) is provided with a right roller groove (801); the rollers (5) are fixed in the left roller groove (201) and the right roller groove (801), the side wall of the piezoelectric stator (7) is tightly contacted with the outer circular surface of the roller (5), and the piezoelectric stator (7) generates micro displacement and generates relative sliding with the roller (5).

4. The single-phase piezoelectric-driven iris apparatus according to claim 3, wherein the piezoelectric actuator further comprises a spring plate (4), the spring plate (4) is placed between the left side wall of the piezoelectric actuator fixing groove (102) and the left fixing plate (2) for applying a lateral pre-pressure;

the bottom plane of the spring piece (4) is tightly adhered to the left side wall of the piezoelectric actuator fixing groove (102), and the left fixing plate (2) is tightly contacted with the top curved surface of the spring piece (4).

5. The single-phase piezoelectric-driven iris apparatus according to claim 4, wherein the right fixing plate (8) is closely adhered to a right groove sidewall of the piezoelectric actuator fixing groove (102).

6. The single-phase piezoelectric driven iris apparatus according to claim 5, wherein the piezoelectric actuator further comprises a spring block (6), a bottom surface of the spring block (6) is closely adhered to a bottom surface of the piezoelectric actuator fixing groove (102), and a top surface is closely contacted to a bottom surface of the piezoelectric stator (7).

7. The single-phase piezoelectrically actuated iris apparatus of claim 1, wherein said piezoelectric stator (7) is rectangular.

8. The single-phase piezoelectric driven iris diaphragm device according to claim 1, further comprising a motor end cap (10), wherein the lower half of the base (1) is provided with a first threaded hole (101) around for fixing the motor end cap (10);

the motor end cover (10) is provided with a second bolt hole (1001) corresponding to the fixing bolt (11) and connected with the first bolt hole (101) of the base (1) through the fixing bolt (11).

9. The single-phase piezoelectric driven iris diaphragm device according to claim 8, wherein the bottom of the motor end cover (10) is provided with a protrusion (1002) for fixing the piezoelectric actuator.

10. The single-phase piezoelectric-driven iris apparatus according to claim 1, wherein the piezoelectric actuator further includes an upper heat-conductive plate (3) and a lower heat-conductive plate (9);

the upper heat conducting fin (3) is arranged on the upper end face of the piezoelectric stator (7), and the lower heat conducting fin (9) is arranged on the lower end face of the piezoelectric stator (7) so as to facilitate heat dissipation of the piezoelectric stator (7);

the piezoelectric stator (7), the upper heat conducting fin (3) and the lower heat conducting fin (9) are tightly pasted together by resin, and the lower end face of the lower heat conducting fin (9) is tightly pasted with the end face of the piezoelectric actuator fixing groove (102).

Technical Field

The invention belongs to the field of aerospace optical instruments, and particularly relates to a single-phase piezoelectric-driven iris diaphragm device.

Background

In order to obtain a clear image, it is necessary to make the optical system achieve optimal exposure under the condition of adapting to the variation of the scene illumination, and the light modulation mechanism is an indispensable component in the optical system and has a close relation with the imaging quality. The iris is a commonly used light modulation device for controlling the illumination of the image plane. At present, an iris diaphragm mainly comprises a light shielding sheet, a diaphragm moving coil and a diaphragm fixed coil, wherein the light shielding sheet is hinged with the moving coil, and the light shielding sheet is driven to rotate through the relative rotation of the moving coil and an annular boss, so that the aperture size of the diaphragm is adjusted, the luminous flux entering a lens is adjusted, and an image plane obtains proper illumination intensity.

In the prior art, two driving methods of electromagnetic motor driving and ultrasonic motor driving are mainly used for adjusting the iris diaphragm. The electromagnetic motor is used as a driving source, and the size of the clear aperture is controlled by adopting worm and gear transmission or gear transmission, so that the whole structure is complex, the transmission precision is low, the service life is short, electromagnetic interference exists, and the electromagnetic motor cannot be applied to a working environment with a strong electromagnetic field. The other type is that an ultrasonic motor is used as a driving source, and the problems that the device is large in size, many in connecting parts, incapable of achieving precise control and the like exist.

The piezoelectric actuator is a novel actuator, applies voltage to piezoelectric materials, and because the stator generates elliptical motion due to the inverse piezoelectric effect, the elliptical vibration of the stator is converted into friction driving force through the direct contact of the stator and the rotor, and the rotor is driven to rotate. The piezoelectric actuator has the unique advantages of compact structure, simple control, light weight, quick response, high precision and the like, and has great application value on optical systems in the fields of medicine, aerospace and the like. However, most of the single-phase piezoelectric actuators can only operate in a single direction, and are difficult to apply to occasions needing to change the operation direction.

Disclosure of Invention

The invention aims to provide a single-phase piezoelectric driven iris diaphragm device, which aims to solve the technical problems of large size and low precision of the traditional iris diaphragm device.

In order to solve the technical problems, the specific technical scheme of the invention is as follows:

a single-phase piezoelectricity driven iris diaphragm device comprises a base, a shading sheet, a moving coil and a piezoelectric actuator;

the piezoelectric actuator comprises a piezoelectric stator;

the center of the top of the piezoelectric stator is provided with a driving foot;

the base comprises an upper half part and a lower half part;

the upper half part of the base is in a ring shape, a circular light through hole is formed in the middle of the base, an annular boss is arranged on the inner ring of the ring, and guide sliding grooves are uniformly distributed on the annular boss and used for limiting the movement of the shading sheet; a groove is arranged at the outer ring of the bearing and used for placing a bearing, and a vertical shaft is arranged in the middle of the groove and used for fixing the bearing; the bearing in the groove and the piezoelectric stator driving foot jointly limit the freedom degree of the moving coil; the vertical shaft and the bearing are in interference fit;

the lower half part of the base is provided with a piezoelectric actuator fixing groove; the piezoelectric actuator fixing groove is used for placing a piezoelectric stator;

the movable coil is annular, and the middle of the movable coil is provided with a light through hole which is coaxial with the light through hole of the base; through holes are uniformly formed in the circumferential direction of the upper end face of the moving coil;

the side wall of the moving coil is circumferentially provided with a U-shaped annular groove, the bottom surface of the U-shaped annular groove is tightly contacted with the bearing, the bearing slides freely in the U-shaped annular groove relatively, and the bearing and the piezoelectric stator driving foot play a limiting role on the moving coil together, so that the moving coil only keeps the rotational freedom degree;

the driving foot is in close contact with the bottom surface of the U-shaped circular groove of the moving coil, so that the driving and positioning effects are achieved;

the shading sheet is of an annular fan-shaped sheet structure, a hinged cylinder is arranged on the upper end face of one end of the shading sheet, and a sliding block cylinder is arranged on the lower end face of the other end of the shading sheet; the hinged cylinder of the upper end face of the shading sheet is hinged with the corresponding through hole on the moving coil, and the slider cylinder of the lower end face of the shading sheet is matched with the corresponding guide sliding groove of the base, so that the shading sheet can rotate in the circumferential direction.

Furthermore, the piezoelectric actuator also comprises a left fixing plate and a right fixing plate;

the left fixing plate is placed in the piezoelectric actuator fixing groove and arranged on the left side of the piezoelectric stator; the right fixing plate is placed in the piezoelectric actuator fixing groove and arranged on the right side of the piezoelectric stator; the left fixing plate and the right fixing plate are used for limiting the position of the piezoelectric stator.

Furthermore, the left fixing plate is provided with a left roller groove, and the right fixing plate is provided with a right roller groove; the rollers are fixed in the left roller groove and the right roller groove, the side wall of the piezoelectric stator is in close contact with the outer circular surface of the roller, and the piezoelectric stator generates micro-displacement and slides relative to the roller.

Furthermore, the piezoelectric actuator also comprises a spring piece, and the spring piece is placed between the left side wall of the piezoelectric actuator fixing groove and the left fixing plate and is used for applying lateral pre-pressure;

the plane of the bottom of the spring piece is tightly pasted with the left side wall of the piezoelectric actuator fixing groove, and the left fixing plate is tightly contacted with the curved surface of the top of the spring piece.

Furthermore, the right fixing plate is tightly adhered to the side wall of the right groove of the piezoelectric actuator fixing groove.

Furthermore, piezoelectric actuator still includes the spring block, the spring block bottom surface closely pastes with piezoelectric actuator fixed slot bottom surface, top surface and piezoelectricity stator bottom surface in close contact with.

Further, the piezoelectric stator is rectangular.

The motor end cover is further included, and first threaded holes are formed in the periphery of the lower half portion of the base and used for fixing the motor end cover;

the motor end cover is provided with a second bolt hole corresponding to the fixing bolt and connected with the first bolt hole of the base through the fixing bolt.

Furthermore, the bottom of the motor end cover is provided with a bulge, so that the piezoelectric actuator is fixed.

Furthermore, the piezoelectric actuator also comprises an upper heat conducting fin and a lower heat conducting fin;

the upper heat conducting fin is arranged on the upper end face of the piezoelectric stator, and the lower heat conducting fin is arranged on the lower end face of the piezoelectric stator so as to facilitate heat dissipation of the piezoelectric stator;

the piezoelectric stator, the upper heat conducting fin and the lower heat conducting fin are tightly pasted together by resin, and the lower end face of the lower heat conducting fin is tightly pasted with the end face of the piezoelectric actuator fixing groove.

The single-phase piezoelectric driven iris diaphragm device has the following advantages:

(1) the invention has simple structure, does not adopt transmission mechanisms such as worm gears or gears, and the like, but directly drives the moving coil to drive the shading sheet to rotate, changes the size of the clear aperture, and reduces the quality of the device, therefore, the invention has the characteristics of small volume, light weight, and the like.

(2) The invention adopts the inverse piezoelectric effect of the piezoelectric material, amplifies the micro deformation resonance of the material by the friction coupling transmission between the driving foot and the moving coil, and converts the micro deformation resonance into the rotation motion of the moving coil. The friction transmission of the driving foot and the moving coil has larger holding torque, can realize power-off self-locking, and has good electromagnetic compatibility, so the invention has higher reliability.

(3) The diaphragm device adopts the inverse piezoelectric effect of the piezoelectric material, the response time of the piezoelectric actuator is in millisecond level, and the piezoelectric actuator does not have inertia during reciprocating motion, so the diaphragm device can achieve millisecond level response speed and nanoscale accurate positioning, and has a larger dynamic range.

(4) The invention only needs single-phase alternating current drive, and can realize forward drive or reverse drive of the motor by selecting a clockwise signal or a counterclockwise signal, thereby realizing the amplification and contraction of the clear aperture.

Drawings

FIG. 1 is a schematic diagram of a partial cross-sectional view of a single-phase piezoelectrically actuated iris apparatus of the present invention;

FIG. 2 is an exploded view of a single phase piezoelectrically actuated iris apparatus of the present invention;

FIG. 3 is a schematic view of the structure of the base of the present invention;

FIG. 4 is a schematic structural view of a left fixing plate according to the present invention;

FIG. 5 is a schematic view of the structure of a piezoelectric stator in the present invention;

FIG. 6 is a schematic illustration of a piezoelectric stator excitation method of the present invention;

FIG. 7 is a schematic structural view of a right fixing plate according to the present invention;

FIG. 8 is a schematic structural view of a motor end cap according to the present invention;

FIG. 9 is a schematic view of the structure of the moving coil of the present invention;

fig. 10 is a schematic structural view of the light-shielding sheet of the present invention.

The notation in the figure is: 1. a base; 2. a left fixing plate; 3. an upper heat-conducting fin; 4. a spring plate; 5. a roller; 6. a spring block; 7. a piezoelectric stator; 8. a right fixing plate; 9. a lower thermally conductive sheet; 10. a motor end cover; 11. fixing the bolt; 12. a bearing; 13. moving coils; 14. a shading sheet; 15. a clockwise signal; 16. a counter-clockwise signal; 101. a first bolt hole; 102. a piezoelectric actuator fixing groove; 103. a groove; 104. a vertical shaft; 105. an annular boss; 106. a guide chute; 201. a left roller groove; 701. a drive foot; 801. a right roller groove; 1001. a second bolt hole; 1002. the bottom of the motor end cover is raised; 1301. the lower end surface of the moving coil; 1302. a through hole; 1303. a U-shaped ring groove; 1401. a slider cylinder; 1402. a hinged cylinder.

Detailed Description

For better understanding of the objects, structure and functions of the present invention, a single-phase piezoelectric-driven iris diaphragm device of the present invention will be described in further detail with reference to the accompanying drawings.

As shown in fig. 1 and 2, the invention discloses a single-phase piezoelectric driven iris diaphragm device, which comprises a base 1, a piezoelectric actuator, a moving coil 13, a light shielding sheet 14 and a motor end cover 10.

The piezoelectric actuator comprises a piezoelectric stator 7, a left fixing plate 2, a right fixing plate 8, an upper heat conducting strip 3, a lower heat conducting strip 9, a roller 5, a spring block 6 and a spring piece 4.

As shown in fig. 3, the lower half of the base 1 is a piezoelectric actuator fixing groove 102. The middle groove of the piezoelectric actuator fixing groove 102 is used for placing the lower heat conducting strip 9, the piezoelectric stator 7 and the upper heat conducting strip 3; a left fixing plate 2 is placed in a left groove of the piezoelectric actuator fixing groove 102, a right fixing plate 8 is placed in a right groove of the piezoelectric actuator fixing groove 102, the left fixing plate 2 and the right fixing plate 8 are used for limiting the position of a piezoelectric stator 7, and a spring piece 4 is placed between the side wall of the left groove of the piezoelectric actuator fixing groove 102 and the left fixing plate 2 and used for applying lateral pre-pressure; a first threaded hole 101 is formed in the periphery of the lower half portion of the base 1 and used for fixing a motor end cover 10;

the upper half part of the base 1 is in a ring shape, a circular light through hole is formed in the middle of the base, an annular boss 105 is arranged on the inner ring of the ring, and a plurality of guide sliding grooves 106 are uniformly distributed on the annular boss 105 and used for limiting the movement of the light shielding sheet 14; two grooves 103 are arranged at the outer ring of the bearing, and are used for placing the bearing 12, and a vertical shaft 104 is arranged in the middle of each groove 103 and is used for fixing the bearing 12; the two grooves 103 are arranged at a certain angle, and the bearings 12 in the two grooves 103 and the piezoelectric stator driving feet 701 jointly limit the freedom degree of the moving coil 13; the vertical shaft 104 and the bearing 12 are in interference fit;

as shown in fig. 9, the moving coil 13 is circular, and has a light through hole in the middle and is coaxial with the light through hole of the base 1; a plurality of through holes 1302 are uniformly formed in the upper end face of the moving coil 13 in the circumferential direction, and the through holes 1302 correspond to the light shading sheet hinged cylinders 1402 one to one;

the side wall of the moving coil 13 is circumferentially provided with a U-shaped ring groove 1303, the bottom surface of the U-shaped ring groove 1303 is tightly contacted with the two bearings 12, the bearings 12 relatively freely slide in the U-shaped ring groove 1303, and together with the piezoelectric stator driving feet 701, the bearing and the moving coil 13 play a limiting role, so that the moving coil 13 only retains the rotational degree of freedom;

as shown in fig. 10, the light shielding sheet 14 is a ring-shaped fan-shaped sheet structure, and a hinge cylinder 1402 is disposed on an upper end surface of one end thereof, and a slider cylinder 1401 is disposed on a lower end surface of the other end thereof; the hinged cylinder 1402 on the upper end surface of the light-shielding sheets 14 is hinged with the corresponding through hole 1302 on the moving coil 13, and the sliding block cylinder 1401 on the lower end surface is matched with the corresponding guide sliding chute 106 of the base 1, so that the light-shielding sheets 14 can rotate in the circumferential direction, and the expansion or contraction of the light-transmitting aperture is further realized;

as shown in fig. 5, the piezoelectric stator 7 is rectangular, a driving foot 701 is arranged at the center of the top of the piezoelectric stator, and the driving foot 701 is in close contact with the bottom surface of the U-shaped annular groove 1303 of the moving coil to perform driving and positioning functions;

as shown in fig. 4 and 7, the left fixing plate 2 is provided with a plurality of left roller grooves 201, the right fixing plate 8 is provided with a plurality of right roller grooves 801, a plurality of rollers 5 are arranged between the fixing plate 2 and the side wall of the piezoelectric stator 7, the rollers 5 are fixed in the corresponding roller grooves, and the side wall of the piezoelectric stator 7 is in close contact with the outer circular surface of the rollers 5, so that the piezoelectric stator 7 generates micro displacement and will generate relative sliding with the rollers 5;

the bottom plane of the spring piece 4 is tightly adhered to the side wall of the left groove of the piezoelectric actuator fixing groove 102, the left fixing plate 2 is tightly contacted with the curved surface of the top of the spring piece 4, the right fixing plate 8 is tightly adhered to the side wall of the right groove of the piezoelectric actuator fixing groove 102, the bottom surface of the spring block 6 is tightly adhered to the bottom surface of the fixing groove, and the top surface of the spring block is tightly contacted with the bottom surface of the piezoelectric stator 7;

the left fixing plate 2, the right fixing plate 8, the roller 5, the spring piece 4 and the spring block 6 jointly limit the piezoelectric stator 7;

as shown in fig. 8, the motor end cover 10 is provided with a plurality of second bolt holes 1001 corresponding to the fixing bolts 11 one by one, and connected with the first bolt holes 101 of the base 1 through the fixing bolts, and a protrusion 1002 at the bottom of the motor end cover 10 is in close contact with the upper heat conducting strip 3, so as to fix the piezoelectric stator 7;

the upper end face of the piezoelectric stator 7 is provided with an upper heat conducting fin 3, and the lower end face of the piezoelectric stator 7 is provided with a lower heat conducting fin 9, so that the piezoelectric stator 7 can dissipate heat;

the piezoelectric stator 7, the upper heat conducting strip 3 and the lower heat conducting strip 9 are tightly pasted together by resin, and the lower end surface of the lower heat conducting strip 9 is tightly pasted with the end surface of the middle groove of the piezoelectric actuator fixing groove 102;

as shown in fig. 6, the control method of the present invention is as follows: the piezoelectric stator adopts a single-phase electric excitation mode, the piezoelectric stator 7 drives the foot to generate standing wave motion through an inverse piezoelectric effect, the moving coil 13 is driven to rotate, and the moving coil 13 drives one end of the shading sheet 14 to rotate so as to change the size of the light-transmitting aperture; by selecting the clockwise signal 15 or the counterclockwise signal 16, the forward driving or the reverse driving of the motor can be realized, and the amplification and the contraction of the clear aperture can be realized.

It is to be understood that the present invention has been described with reference to certain embodiments, and that various changes in the features and embodiments, or equivalent substitutions may be made therein by those skilled in the art without departing from the spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.