A theatre car platform operation noise active elimination device and a noise reduction method thereof

Abstract

The present application relates to a kind of theatre car platform operation noise active elimination device and its noise reduction method, including the mobile trolley being arranged in fixed platform and four soundproof cover assemblies, mobile trolley includes pedestal, bearing platform and lifting actuator, four soundproof cover assemblies form and are located outside lifting actuator in the form of enclosure, soundproof cover assembly includes the soundproof board fixed at the bottom of bearing platform, winding roller and motor, soundproof board is equipped with active noise reduction component, pickup cover is located at the top of pedestal and is wrapped four winding rollers, it is formed with four soundproof boards and forms closed space, pickup cover is equipped with energy-consuming component, the present application forms dynamic enclosure by soundproof board, realizes physical self-adapting elimination to low-frequency noise using active noise reduction component, and combine energy-consuming component in pickup cover and carry out multiple reflection energy consumption to residual noise, effectively solve the problem that car platform operation noise is big, low-frequency noise is difficult to eliminate and sound insulation is not thorough.

Description

Technical Field

[0001] This invention belongs to the field of stage noise reduction technology, and relates to an active noise cancellation device and method for theater vehicle operation, particularly an active noise cancellation device and method for theater vehicle operation adapted to the lifting and lowering motion of a mobile trolley. Background Technology

[0002] As art venues with extremely demanding acoustic requirements, theaters are vulnerable to even the slightest background noise that can disrupt the purity and immersion of a performance. During high-speed operation and start-stop, the stage trailer generates complex broadband noise from its lifting mechanisms, transmission components, and the friction between its wheels and tracks, especially low-frequency vibration noise containing a large amount of energy. This type of low-frequency noise has a long wavelength and extremely strong penetrating power, easily bypassing ordinary physical barriers. It can also propagate over long distances in large spaces such as auditoriums, attenuating slowly. This not only masks subtle dialogue from actors and soft orchestral playing but also causes secondary radiation through the building structure via solid-borne sound transmission, severely interfering with the artistic expression of the performance.

[0003] Currently, most noise reduction methods used in the industry are limited to passive protection measures such as laying sound-absorbing cotton or installing fixed sound insulation panels. While these methods have some effect on blocking mid-to-high frequency noise, they are ineffective against the low-frequency noise unique to stage machinery. Although electronic active noise cancellation (ANC) technology has matured in small-space applications such as headphones, it faces severe challenges in ultra-large spaces like theaters. To cover the dynamic changes in the moving area of ​​the stage, a massive array of sensors and high-performance processors are needed to generate anti-phase sound waves in real time. This not only leads to an extremely complex system architecture and an exponential increase in construction costs, but also makes the algorithm prone to failure or system malfunction in the complex electromagnetic environment of the stage, making it difficult to meet the safety requirements of high-frequency, long-term stable operation of stage equipment.

[0004] In addition to the limitations of noise reduction technology itself, the motion characteristics of the mobile equipment also pose a significant challenge to sound insulation design. Most existing sound insulation structures are fixed and cannot deform or expand synchronously with the lifting and lowering movements of the mobile trolley, inevitably resulting in sound insulation gaps during equipment lifting and lowering, causing serious noise leakage. Even more problematic is that even if a closed space is created through enclosures, without an effective energy absorption mechanism, noise will form standing waves and reverberation within the sealed soundproof enclosure, causing a sharp increase in internal sound pressure level. Ultimately, the noise will still escape through gaps or structural conduction, creating the awkward situation of "sound insulation without noise reduction." An innovative solution that can both dynamically seal and physically dissipate low-frequency energy is urgently needed. Summary of the Invention

[0005] In view of this, in order to solve the problems of existing theater vehicle noise reduction technologies, such as difficulty in low-frequency noise reduction, poor dynamic sealing, high cost and insufficient stability of electronic active noise reduction solutions, and difficulty in meeting the high-frequency operation requirements of equipment and stringent acoustic environment standards, this invention provides an active noise cancellation device for theater vehicle operation and its noise reduction method.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A theater stage noise reduction device includes a mobile stage within a fixed theater stage frame, comprising a base, a support platform, and a lifting mechanism positioned between the base and the support platform. The device also includes:

[0008] Four soundproof enclosure assemblies form a barrier and are located outside the lifting actuator;

[0009] Each soundproof enclosure assembly includes a soundproof panel, a winding roller for winding the soundproof panel, and a motor for driving the winding roller to rotate. The top of the soundproof panel is fixed to the bottom of the support platform, and an active noise reduction component is provided inside the soundproof panel.

[0010] In addition, a sound pickup cover is set on top of the base to cover the four take-up rollers. The sound pickup cover works in conjunction with four sound insulation panels to isolate the space between the base and the support platform from the external space. The sound pickup cover contains energy-consuming components for consuming noise.

[0011] As a further improvement to the above technical solution:

[0012] The bottom of the microphone cover has a clearance cavity for accommodating four soundproof cover assemblies. Multiple microphone boxes are fixedly installed on the inner wall of the clearance cavity. A microphone opening is provided on one side of each microphone box. Multiple reflective protrusions are provided inside the microphone box. The reflective protrusions are used to cause noise entering the microphone box to be reflected multiple times to dissipate energy.

[0013] Multiple diaphragms are fixedly arranged on one side of the inner wall of the pickup opening. The length of the multiple diaphragms decreases from the inside to the outside, and the movable ends of the multiple diaphragms are all inclined towards the inside of the pickup box to form a one-way valve structure that allows noise to enter the pickup box in one direction.

[0014] As a further improvement to the above technical solution:

[0015] The soundproof enclosure assembly also includes two support frames I fixed to the top of the base, a winding roller rotatably connected between the two support frames I, and a motor fixed to one side of one of the support frames I.

[0016] The soundproof enclosure assembly also includes two support frames II fixed to the top of the base. The support frames II are located inside the support frame I. A guide roller is rotatably provided between the two support frames II. One end of the soundproof plate passes around the guide roller and is fixedly connected to the bottom of the support platform.

[0017] As a further improvement to the above technical solution:

[0018] The sound insulation panel includes multiple sound insulation baffles connected in sequence. The top of the sound insulation baffle is provided with a pin, and the bottom of the sound insulation baffle is provided with a positioning tube that matches the pin. In two adjacent sound insulation baffles, the pin of one sound insulation baffle is inserted into the positioning tube of the other sound insulation baffle and is axially limited by a limiting plate.

[0019] The positioning cannula includes an outer cannula fixed to the bottom of the sound insulation baffle and an inner cannula set inside the outer cannula. A clearance cavity is formed between the inner cannula and the outer cannula. Multiple leaf springs are provided in the clearance cavity. The outer side of the leaf spring is fixed to the inner wall of the outer cannula, and the inner side of the leaf spring is fixed to the outer wall of the inner cannula, so that the inner cannula can move elastically inside the outer cannula.

[0020] As a further improvement to the above technical solution:

[0021] The active noise reduction component includes an installation cavity on the outside of a soundproof baffle, a sealing cover fixed in the installation cavity, and a movable back plate movably installed in the installation cavity. The inner side of the soundproof baffle has sound-absorbing micropores. A resonant cavity is formed between the movable back plate and the soundproof baffle. Noise enters the resonant cavity through the sound-absorbing micropores and drives the movable back plate to vibrate. The volume of the resonant cavity changes with the movement of the movable back plate to change the resonant frequency of the resonant cavity so that it matches the main frequency of the incident noise.

[0022] The active noise cancellation component also includes multiple sets of springs. One end of each set of springs is fixedly connected to the inside of the sealing cover, and the other end of each set of springs is fixedly connected to the movable back plate. The springs dissipate the noise energy transmitted by the movable back plate through elastic deformation.

[0023] A noise reduction method based on an active noise cancellation device for theater van operation includes the following steps:

[0024] S1. Four soundproof enclosure assemblies form a barrier structure that wraps around the outside of the lifting actuator, and the soundproof panels unfold and roll up synchronously with the lifting of the support platform to initially block noise penetration and avoid creating soundproof gaps.

[0025] S2. When the lifting actuator generates low-frequency noise, the noise enters the resonant cavity through the sound-absorbing micropores in the active noise reduction component in the sound insulation panel, causing the movable back plate to vibrate and the spring to undergo elastic deformation to consume the noise energy. At the same time, the volume of the resonant cavity is adaptively adjusted by the movement of the movable back plate to match and eliminate the low-frequency noise.

[0026] S3. By combining the pickup cover fixed to the top of the base with four sound insulation panels, a closed sound insulation space is formed to prevent noise from spreading to the outside.

[0027] S4. The remaining noise in the enclosed space is captured by the energy-consuming components inside the pickup cover, so that the noise enters the pickup box through the pickup opening and is reflected multiple times between the reflective protrusions to consume energy. At the same time, the one-way valve structure made of diaphragm is used to prevent the noise from escaping from the pickup box.

[0028] The beneficial effects of this invention are as follows:

[0029] 1. The active noise cancellation device for theater vehicle operation disclosed in this invention consists of four soundproof enclosure assemblies that surround the lifting actuator. The soundproof panel is composed of multiple soundproof baffles spliced ​​together, which can initially block noise penetration. At the same time, the leaf spring inside the positioning tube can absorb vibration energy and reduce the additional noise generated by vibration transmission. The sound pickup cover and the soundproof panel work together to form a closed soundproof space, further blocking the noise from spreading to the outside, thus solving the problems of incomplete sound insulation and easy noise leakage in existing devices.

[0030] 2. The active noise cancellation device for theater vehicle operation disclosed in this invention uses an active noise reduction component in the sound insulation panel based on the physical adaptive variable cavity principle of a spring-mass block system. It does not rely on electronic equipment. It captures low-frequency noise through sound-absorbing micropores. The noise causes the movable back plate to vibrate, and the elastic deformation of the spring consumes the noise energy. At the same time, the volume of the resonant cavity can be adaptively adjusted to accurately match the noise frequency, thereby achieving targeted elimination of low-frequency noise and solving the defect of existing passive sound insulation that cannot effectively deal with low-frequency noise.

[0031] 3. The active noise cancellation device for theater vehicle operation disclosed in this invention has multiple microphone boxes inside the microphone cover that can fully capture the remaining noise in the enclosed space. The reflective protrusions inside the microphone box cause the noise to be reflected multiple times, and the noise energy is gradually consumed through collision and friction. At the same time, the diaphragm at the microphone opening forms a one-way valve structure to prevent the noise from escaping in the reverse direction, ensuring that the noise is fully consumed in the microphone box, avoiding the noise from reflecting back and forth and reverberating in the enclosed space, and further improving the noise reduction effect.

[0032] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0033] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein:

[0034] Figure 1 This is a schematic diagram of the mobile trolley structure of the active noise cancellation device for theater vehicle operation according to the present invention;

[0035] Figure 2 This is a schematic diagram of the soundproof enclosure assembly, the mobile trolley, and the sound pickup enclosure in this invention;

[0036] Figure 3 This is a schematic diagram of the soundproof enclosure assembly in this invention;

[0037] Figure 4 This is a schematic diagram of the interconnection structure of the sound insulation panels in this invention;

[0038] Figure 5 This is a cross-sectional view of the positioning cannula in this invention;

[0039] Figure 6 This is a cross-sectional view of the sound insulation baffle in this invention;

[0040] Figure 7 This is a cross-sectional view of the microphone cover in this invention;

[0041] Figure 8 This is a schematic diagram of the internal structure of the pickup box in this invention.

[0042] Reference numerals: 1. Fixed frame; 2. Moving trolley; 21. Base; 22. Support plate; 23. Lifting mechanism; 3. Soundproof cover assembly; 31. Support frame I; 32. Take-up roller; 33. Guide roller; 34. Motor; 35. Soundproof panel; 351. Soundproof baffle; 36. Support frame II; 3511. Sound-absorbing micropores; 3512. Resonance cavity; 3513. Mounting cavity; 3514. Sealing cover; 3515, Spring; 3516, Movable backplate; 352, Pin; 353, Positioning tube; 3531, External tube; 3532, Internal tube; 3533, Clearance cavity; 3534, Leaf spring; 354, Rectangular opening; 355, Limiting groove; 356, Limiting plate; 4, Sound pickup cover; 41, Clearance cavity; 42, Sound pickup box; 421, Sound pickup opening; 422, Reflective protrusion; 423, Diaphragm. Detailed Implementation

[0043] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0044] like Figure 1The active noise cancellation device for theater stage trailers shown is mainly used to actively eliminate and isolate the mechanical noise generated during the operation of theater stage trailers, such as lifting and moving, to prevent noise from spreading to the audience area and affecting the viewing experience. The device consists of a fixed frame 1, a mobile trolley 2, four soundproof enclosure assemblies 3, and a sound pickup enclosure 4.

[0045] The fixed frame 1 serves as the installation base for the entire device. It is constructed from welded steel sections and has internal space reserved for the installation of the mobile trolley 2. The mobile trolley 2 can move and rise smoothly within the fixed frame 1, meeting the normal operation requirements of the theater vehicle. Figure 2 As shown, the mobile trolley 2 consists of a base 21, a support platform 22, and a lifting mechanism 23. The base 21 is a flat structure made of high-strength steel plate and is used to support the entire mobile trolley 2 and the stage equipment and performers above it. The support platform 22 is located above the base 21 and is parallel to the base 21. The top of the support platform 22 is used to lay the stage panel, providing a flat support surface for the performers' performances and equipment placement. Its bottom is fixed to the top of the sound insulation board 35, which can drive the sound insulation board 35 to move synchronously with the lifting mechanism. The lifting mechanism 23 is located between the base 21 and the support platform 22. Its bottom end is fixedly connected to the base 21, and its top end is fixedly connected to the support platform 22. Through the extension and retraction of the lifting mechanism 23, the support platform 22 can be moved up and down to realize the lifting function of the trolley and meet the needs of different performance scenarios. The whole system adopts the lifting stage described in patent document CN119877909B. The mechanical vibration and noise generated by the lifting mechanism 23 during operation are the main noise reduction targets of this device.

[0046] Four soundproof enclosure assemblies 3 are arranged in a barrier-like manner outside the lifting actuator 23, corresponding to the four sides of the moving trolley 2 respectively. The four soundproof enclosure assemblies 3 cooperate with each other to form a complete enclosure for the lifting actuator 23, reducing the noise generated by the lifting actuator 23 during operation from spreading to the outside. Figure 3As shown, each soundproof enclosure assembly 3 includes a support frame I 31, a take-up roller 32, a guide roller 33, a motor 34, a soundproof panel 35, and a support frame II 36. Both support frames I 31 are bolted to the top of the base 21. The two support frames I 31 are parallel to each other and spaced apart, with the spacing matching the length of the take-up roller 32. This serves as the mounting support structure for the take-up roller 32, ensuring its stable rotation. The take-up roller 32 is rotatably connected between the two support frames I 31 via bearings. The take-up roller 32 can rotate freely around its own axis, used for winding and unwinding the soundproof panel 35. Motor 34 is bolted to one side of one of the support frames I31. Motor 34 is a geared motor, and its output end is fixedly connected to one end of the take-up roller 32 through a coupling. By rotating the motor 34 forward and reverse, the take-up roller 32 can be driven to rotate clockwise or counterclockwise, thereby realizing the winding and unfolding of the sound insulation panel 35. The operation of motor 34 is linked with the lifting actuator 23 to ensure that the movement of the sound insulation panel 35 is synchronized with the lifting of the support platform 22. PLC controller is also included. The PLC controller is electrically connected to the four motors 34 and the lifting actuator 23 respectively. The PLC controller receives the lifting signal of the lifting actuator 23 and synchronously controls the four motors 34 to rotate forward and reverse, so as to realize the synchronous winding and unfolding of the sound insulation panel 35 and the support platform 22, ensuring the integrity of the fence and avoiding the appearance of sound insulation gaps.

[0047] Two support frames II 36 are also bolted to the top of the base 21 and located inside the support frame I 31. The two support frames II 36 are parallel to each other, and the spacing is adapted to the length of the guide roller 33 to support the stable rotation of the guide roller 33. The guide roller 33 is rotatably connected between the two support frames II 36 through bearings. The axis of the guide roller 33 is parallel to the axis of the take-up roller 32 and is used to guide the movement direction of the sound insulation plate 35 to prevent the sound insulation plate 35 from shifting or jamming during winding and unwinding. At the same time, the surface of the guide roller 33 is smoothed to reduce the friction when the sound insulation plate 35 moves and reduce the additional noise generated by friction. The bearings of the take-up roller 32 and the guide roller 33 are equipped with sealed dust covers to prevent dust and debris from entering the bearing. One end of the sound insulation plate 35 is fixed and wrapped around the outer wall of the take-up roller 32, and the other end passes over the guide roller 33 and is fixedly connected to the bottom of the support platform 22. The guide roller 33 can change the force direction of the sound insulation plate 35, so as to avoid the change of the diameter of the sound insulation plate 35 before and after the take-up roller 32 rolls it up and change the position of the bottom end of the sound insulation plate 35. This ensures that the sound insulation plate 35 can be opened and rolled up synchronously with the lifting and lowering of the support platform 22. When the lifting actuator 23 drives the support platform 22 to rise, the sound insulation plate 35 is opened up synchronously, forming a barrier for the lifting actuator 23 and blocking noise leakage. When the support platform 22 descends, the motor 34 drives the take-up roller 32 to rotate, and rolls the sound insulation plate 35 onto the take-up roller 32, so as to avoid the sound insulation plate 35 accumulating on the base 21 and affecting the operation of the equipment. At the same time, the winding process is smooth and no winding noise is generated.

[0048] like Figure 4 As shown, the sound insulation panel 35 is composed of multiple sound insulation baffles 351 spliced ​​together. These baffles 351 are connected sequentially and can be bent and rolled up and straightened as the winding roller 32 rotates. This ensures both the rigidity of the sound insulation panel 35 and good rollability, adapting to roll-up and storage needs. A pin 352 is integrally formed at the top of each sound insulation baffle 351. The pin 352 is a cylindrical structure and is positioned along the length of the sound insulation baffle 351, serving as a connecting component between adjacent baffles 351. A positioning tube 353 is bolted to the bottom of each sound insulation baffle 351. The positioning tube 353 is hollow, and its inner diameter matches the outer diameter of the pin 352. Adjacent sound insulation baffles 351 are spliced ​​by inserting the pin 352 of the upper baffle 351 into the positioning tube 353 of the lower baffle 351, ensuring the overall structure is stable after splicing. A rectangular opening 354 is provided on one side of the positioning tube 353. The width of the rectangular opening 354 is slightly larger than the width of the base of the pin 352, which facilitates the insertion and removal of the pin 352. At the same time, it can provide a certain amount of rotation space for the positioning tube 353 when the sound insulation plate 35 is bent and rolled up, so as to avoid jamming and ensure the service life of the sound insulation plate 35.

[0049] Both ends of the pin 352 and the positioning tube 353 are provided with limiting grooves 355. The limiting grooves 355 are arc-shaped grooves, and limiting plates 356 are embedded in the limiting grooves 355. The limiting plates 356 are fixedly connected to the pin 352 by bolts. The size of the limiting plates 356 is adapted to the size of the limiting grooves 355, which can limit the pin 352 and the positioning tube 353, prevent relative movement between two adjacent sound insulation baffles 351, ensure the flatness and stability of the sound insulation panels 35 when unfolded, avoid additional noise caused by shaking, and further improve the sealing of the splice and reduce noise leakage from the splice gap.

[0050] like Figure 5As shown, the positioning cannula 353 consists of an outer cannula 3531 and an inner cannula 3532. The outer cannula 3531 is fixed to the bottom of the sound insulation baffle 351 by bolts. The outer cannula 3531 is a hollow cylindrical structure and serves as the mounting carrier for the inner cannula 3532. The inner cannula 3532 is located inside the outer cannula 3531, and a clearance cavity 3533 is formed between the inner cannula 3532 and the outer cannula 3531. Multiple leaf springs 3534 are provided in the clearance cavity 3533. The multiple leaf springs 3534 are evenly distributed along the circumference of the outer cannula 3531. The two ends of two adjacent leaf springs 3534 abut against each other. The outer side of the leaf spring 3534 is fixed to the inner wall of the outer cannula 3531 by bolts, and the inner side of the leaf spring 3534 is fixed to the outer wall of the inner cannula 3532 by bolts. The inner insertion tube 3532 has a certain elastic movement space within the outer insertion tube 3531. When the sound insulation plate 35 is vibrated, the leaf spring 3534 can undergo elastic deformation, consuming vibration energy through deformation friction, reducing vibration transmission, and thus reducing vibration noise. At the same time, the elastic restoring effect of the leaf spring 3534 ensures that the inner insertion tube 3532 is always in the centered position, guaranteeing the connection stability between the pin 352 and the positioning insertion tube 353. The limiting grooves 355 are formed at both ends of the inner insertion tube 3532, corresponding to the limiting grooves 355 on the pin 352, ensuring that the limiting plate 356 can be simultaneously embedded in the limiting grooves 355 of both the pin 352 and the inner insertion tube 3532, achieving reliable limiting and further improving the stability of the splice.

[0051] like Figure 6As shown, the sound insulation panel 35 is equipped with an active noise reduction component, which includes a mounting cavity 3513, a sealing cover 3514, a movable back plate 3516, sound-absorbing micropores 3511, a resonant cavity 3512, and a spring 3515. This component is based on the physical adaptive variable cavity principle of a spring-mass system to achieve purely mechanical active noise reduction without relying on electronic algorithms. The mounting cavity 3513 is located on the outside of the sound insulation panel 351 and is a rectangular cavity, serving as the installation space for the active noise reduction component. The sealing cover 3514 is fixed to the opening of the mounting cavity 3513 with bolts to seal the mounting cavity 3513, preventing dust and debris from entering the mounting cavity 3513 and affecting the operation of the active noise reduction component. At the same time, the sealing cover 3514 can enhance the rigidity of the sound insulation panel 351 and reduce its own vibration. The movable backplate 3516 is disposed inside the mounting cavity 3513, parallel to the inner side of the sound insulation baffle 351. A guide slider and guide groove are fitted between the two sides of the movable backplate 3516 and the inner wall of the mounting cavity 3513 to guide and limit the movement of the movable backplate 3516. The movable backplate 3516 can move along the thickness direction of the sound insulation baffle 351 within the mounting cavity 3513, acting as a mass block in a spring-mass system, and can displace in response to noise vibrations. Sound-absorbing micropores 3511 are formed inside the sound insulation baffle 351, with multiple micropores 3511 evenly distributed. The micropores 3511 are connected to the mounting cavity 3513, allowing external noise to enter the mounting cavity 3513 through the micropores, providing a noise input channel for active noise reduction.

[0052] A resonant cavity 3512 is formed between the movable backplate 3516 and the sound insulation baffle 351. The volume of the resonant cavity 3512 can change with the movement of the movable backplate 3516, and the volume of the resonant cavity 3512 directly determines the peak sound absorption frequency of the active noise cancellation component. Multiple sets of springs 3515 are fixed to the inner side of the sealing cover 3514 by bolts. The multiple sets of springs 3515 are evenly distributed along the length of the sealing cover 3514. The other end of each set of springs 3515 is fixedly connected to the movable backplate 3516. As an elastic component in the spring-mass system, when the spring 3515 is in its natural state, the movable backplate 3516 is in the middle position of the mounting cavity 3513. When the vehicle generates low-frequency noise during operation, the noise enters the resonant cavity 3512 through the sound-absorbing micropores 3511, causing the movable back plate 3516 to vibrate. When the movable back plate 3516 vibrates, it compresses or stretches the spring 3515. The elastic deformation of the spring 3515 can consume noise energy through molecular friction. At the same time, the volume of the resonant cavity 3512 changes with the movement of the movable back plate 3516, which can adaptively adjust the resonant frequency to match the current noise frequency, thereby achieving active elimination of low-frequency noise and preventing noise from being radiated secondary through the sound insulation plate 35.

[0053] like Figure 7As shown, the pickup cover 4 is fixed to the top of the base 21 by bolts. The pickup cover 4 has a frame structure with a relief cavity 41 at the bottom. The size of the relief cavity 41 is adapted to the overall size of the four soundproof cover assemblies 3 to accommodate the four soundproof cover assemblies 3, avoiding interference between the pickup cover 4 and the soundproof cover assemblies 3. At the same time, it can wrap and protect components such as the winding roller 32 and the motor 34 to prevent dust and debris from damaging them and reduce additional noise generated by component wear. The pickup cover 4 cooperates with the four soundproof plates 35 to isolate the space between the base 21 and the support platform 22 from the external space, forming a closed soundproof space, reducing the diffusion of noise to the outside, and providing a closed environment for noise energy consumption elimination. A flexible sealing strip is installed on the top opening edge of the pickup cover 4. The flexible sealing strip slides and seals against the outer surface of the soundproof plate 35, which can maintain the airtightness of the closed space and allow the soundproof plate 35 to slide smoothly during lifting and winding.

[0054] The microphone cover 4 contains a power dissipation component, which consists of multiple microphone boxes 42. These microphone boxes 42 are bolted to the inner wall of the clearance cavity 41 and are evenly distributed around the microphone cover 4 and its top wall, enabling comprehensive capture of noise within the enclosed space. For example... Figure 8 As shown, each pickup box 42 has a hollow cavity structure. A pickup opening 421 is provided on the side of the pickup box 42 facing the base 21. The pickup opening 421 faces the space between the base 21 and the support platform 22, allowing noise in this space to enter the pickup box 42 through the pickup opening 421, thus capturing the noise. The inside of the pickup box 42 has multiple reflective protrusions 422, which are evenly distributed on the inner wall of the pickup box 42 in an irregular arrangement. When noise enters the pickup box 42, it will be reflected multiple times between the reflective protrusions 422. Each reflection will collide and rub against the reflective protrusions 422, consuming some noise energy. After multiple reflections, the noise energy is gradually consumed, thereby achieving noise energy dissipation and elimination, further reducing the noise intensity in the enclosed space.

[0055] Multiple diaphragms 423, made of flexible silicone, are fixed to the inner wall of the pickup opening 421. These diaphragms are stacked sequentially, with their lengths decreasing from the inside out, forming a structure similar to a one-way valve. This structure is based on the one-way capture principle of a mechanical valve sound-absorbing array, achieving one-way blocking of sound waves. The movable ends of the diaphragms 423 are all tilted towards the pickup box 42, allowing noise to enter the pickup box 42 unidirectionally and preventing it from escaping in the opposite direction. When noise enters the pickup box 42 from the pickup opening 421, the pressure generated by the noise easily pushes open the movable ends of the diaphragms 423, allowing the noise to enter smoothly. When the noise reflects within the pickup box 42 and attempts to escape from the pickup opening 421, the movable ends of the diaphragms 423 adhere to each other due to their own weight and the noise pressure, forming a seal to prevent noise escape. This ensures that the noise is fully reflected and dissipated within the pickup box 42, further improving the noise reduction effect.

[0056] This device requires regular lubrication and maintenance of the bearings of the take-up roller 32 and guide roller 33, regular inspection of the sealing dust cover's sealing performance, and timely replacement if sealing failure occurs; regular inspection of the elasticity of spring 3515 and leaf spring 3534, and timely replacement if fatigue failure occurs, to ensure that the device can stably perform its noise reduction function for a long time.

[0057] The noise reduction method of this device is as follows:

[0058] Four soundproof enclosure assemblies 3 form a barrier structure that wraps around the outside of the lifting actuator 23. The soundproof panel 35 is composed of multiple soundproof baffles 351 spliced ​​together. The soundproof baffles 351 are filled with soundproof cotton, which can initially block the noise generated by the operation of the lifting actuator 23 from spreading to the outside, forming the first line of noise reduction. The soundproof panel 35 unfolds and retracts synchronously with the lifting of the support platform 22, always maintaining a complete enclosure of the lifting actuator 23. The leaf spring 3534 inside the positioning tube 353 can absorb vibration energy, reduce the noise generated by vibration transmission, and help improve the isolation and noise reduction effect.

[0059] When the lifting actuator 23 generates low-frequency noise, the noise enters the resonant cavity 3512 through the sound-absorbing micropores 3511 on the inner side of the sound insulation baffle 351. The vibration generated by the noise drives the movable back plate 3516 to move within the mounting cavity 3513. When the movable back plate 3516 moves, it compresses or stretches the spring 3515. The elastic deformation of the spring 3515 consumes noise energy through molecular friction. At the same time, the volume of the resonant cavity 3512 changes with the movement of the movable back plate 3516, adaptively adjusting the peak sound absorption frequency to precisely match the current noise frequency, thereby achieving targeted elimination of low-frequency noise and preventing secondary radiation of noise through the sound insulation plate 35, forming a second line of noise reduction defense.

[0060] The sound pickup cover 4 is fixed to the top of the base 21 and, together with the four sound insulation panels 35, forms a closed soundproof space. This space encloses noise sources such as the lifting actuator 23 and the sound insulation cover assembly 3, preventing noise from spreading outwards and forming a third line of noise reduction. Simultaneously, the energy-dissipating components inside the sound pickup cover 4 capture residual noise within the closed space through multiple sound pickup boxes 42. After entering the sound pickup box 42 through the sound pickup opening 421, the noise undergoes multiple reflections between the internal reflective protrusions 422. Each reflection consumes a portion of the noise energy. After these high-frequency reflections, the noise energy is gradually dissipated, achieving energy-dissipating elimination of the remaining noise.

[0061] Multiple diaphragms 423 at the pickup opening 421 form a one-way valve structure, achieving one-way blocking of sound waves based on the one-way capture principle of the mechanical valve sound-absorbing array. Noise can easily push open the movable end of the diaphragm 423 and enter the pickup box 42. When the noise attempts to escape after being reflected inside the pickup box 42, the movable ends of the diaphragms 423 stick together to form a seal, preventing the noise from escaping. This ensures that the noise can be fully reflected and dissipated within the pickup box 42, avoiding the noise from reflecting and reverberating back and forth in the enclosed space, further improving the noise reduction effect and forming a fourth line of noise reduction defense.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A theater stage noise reduction device, wherein the mobile stage (2) includes a base (21), a support platform (22), and a lifting actuator (23) disposed between the base (21) and the support platform (22), characterized in that, The lifting actuator (23) is surrounded by four soundproof enclosure assemblies (3). Each soundproof enclosure assembly (3) includes a soundproof panel (35), a winding roller (32) for winding the soundproof panel (35), and a motor (34) for driving the winding roller (32) to rotate. The top of the soundproof panel (35) is fixed to the bottom of the support platform (22). The soundproof panel (35) includes multiple soundproof baffles (351) that are rotatably connected in sequence and have active noise reduction components inside. The active noise reduction components include a mounting cavity (3513) opened on the outside of the soundproof baffle (351) and a sealing cover fixed in the mounting cavity (3513). The plate (3514) and the movable back plate (3516) are movably set in the mounting cavity (3513). The inner side of the sound insulation baffle (351) is provided with sound-absorbing micropores (3511). A resonant cavity (3512) is formed between the movable back plate (3516) and the sound insulation baffle (351). Noise enters the resonant cavity (3512) through the sound-absorbing micropores (3511) and drives the movable back plate (3516) to vibrate. The volume of the resonant cavity (3512) changes with the movement of the movable back plate (3516) to change the resonant frequency of the resonant cavity (3512) so that it matches the main frequency of the incident noise for energy consumption and noise reduction. The base (21) is equipped with a sound pickup cover (4) for wrapping four take-up rollers (32). The sound pickup cover (4) works in conjunction with four sound insulation plates (35) to isolate the space between the base (21) and the support platform (22) from the external space. The sound pickup cover (4) is equipped with an energy-consuming component for consuming noise. The bottom of the pickup cover (4) is provided with a clearance cavity (41) for accommodating four soundproof cover assemblies (3). The energy dissipation component inside the pickup cover (4) includes multiple pickup boxes (42) fixedly installed on the inner wall of the clearance cavity (41) and having pickup openings (421). Multiple reflective protrusions (422) are provided inside the pickup box (42). The reflective protrusions (422) are used to cause noise entering the pickup box (42) to be reflected multiple times to consume energy. Multiple diaphragms (423) are fixedly installed on the inner wall of one side of the pickup opening (421). The length of the multiple diaphragms (423) decreases from the inside to the outside, and the movable ends of the multiple diaphragms (423) are all inclined towards the pickup box (42) to form a one-way valve structure that allows noise to enter the pickup box (42) in one direction. The active noise reduction component also includes multiple sets of springs (3515), one end of which is fixedly connected to the inner side of the sealing cover plate (3514), and the other end of which is fixedly connected to the movable back plate (3516). The springs (3515) consume the noise energy transmitted by the movable back plate (3516) through elastic deformation. The soundproof cover assembly (3) also includes two support frames I (31) fixed to the top of the base (21), and the winding roller (32) rotates. The motor (34) is fixed to one side of one of the support frames (31) and is connected between two support frames I (31). The soundproof cover assembly (3) also includes two support frames II (36) fixed to the top of the base (21). The support frames II (36) are located inside the support frames I (31). A guide roller (33) is rotatably provided between the two support frames II (36). One end of the soundproof plate (35) passes around the guide roller (33) and is fixedly connected to the bottom of the support platform (22).

2. The active noise cancellation device for theater vehicle operation according to claim 1, characterized in that, The top of the soundproof baffle (351) is provided with a pin (352), and the bottom of the soundproof baffle (351) is provided with a positioning tube (353) that is compatible with the pin (352). In two adjacent soundproof baffles (351), the pin (352) of one soundproof baffle (351) is inserted into the positioning tube (353) of the other soundproof baffle (351).

3. The active noise cancellation device for theater vehicle operation according to claim 2, characterized in that, Both ends of the pin (352) and the positioning tube (353) are provided with limiting grooves (355). The limiting grooves (355) are arc-shaped grooves, and a limiting plate (356) is embedded in the limiting grooves (355) to axially limit the pin (352) and the positioning tube (353).

4. The active noise cancellation device for theater vehicle operation according to claim 2, characterized in that, The positioning cannula (353) includes an outer cannula (3531) fixed to the bottom of the sound insulation baffle (351) and an inner cannula (3532) disposed inside the outer cannula (3531). A clearance cavity (3533) is formed between the inner cannula (3532) and the outer cannula (3531). A plurality of leaf springs (3534) are provided in the clearance cavity (3533). The outer side of the leaf spring (3534) is fixed to the inner wall of the outer cannula (3531), and the inner side of the leaf spring (3534) is fixed to the outer wall of the inner cannula (3532), so that the inner cannula (3532) can move elastically inside the outer cannula (3531).

5. A noise reduction method based on the active noise cancellation device for theater vehicle operation as described in claim 1, characterized in that, Includes the following steps: S1. The four soundproof enclosure assemblies (3) form a barrier structure, which wraps around the outside of the lifting actuator (23), and the soundproof panel (35) unfolds and rolls up synchronously with the lifting of the support platform (22) to initially block noise penetration and avoid creating soundproof gaps. S2. When the lifting actuator (23) generates low-frequency noise, the noise enters the resonant cavity (3512) through the sound-absorbing micropores (3511) in the active noise reduction component in the sound insulation plate (35), causing the movable back plate (3516) to vibrate, causing the spring (3515) to undergo elastic deformation to consume noise energy. At the same time, the volume of the resonant cavity (3512) is adaptively adjusted by the movement of the movable back plate (3516) to match and eliminate low-frequency noise. S3. By combining the pickup cover (4) fixed on the top of the base (21) with the four sound insulation panels (35), a closed sound insulation space is formed to prevent noise from spreading to the outside. S4. The remaining noise in the enclosed space is captured by the energy-consuming component in the pickup cover (4), so that the noise enters the pickup box (42) through the pickup opening (421) and is reflected multiple times between the reflective protrusions (422) to consume energy. At the same time, the one-way valve structure composed of the diaphragm (423) is used to prevent the noise from escaping from the pickup box (42).

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