A vibration reduction and noise reduction technology evaluation and R&D system platform for rail transit

Abstract

This invention discloses a system platform for evaluating and developing vibration and noise reduction technologies for rail transit. It includes a semi-anechoic chamber, a tunnel, a simulated track, and a scaled-down train running on the simulated track. The tunnel is enclosed by sound-absorbing panels. A doorway is provided in the side wall of the semi-anechoic chamber, and the exit of the tunnel connects to the doorway. The entrance of the tunnel is located at the end of the tunnel furthest from the semi-anechoic chamber. The simulated track extends continuously from the outside of the tunnel through the entrance, exit, and doorway into the semi-anechoic chamber. This invention combines the simulated track and the semi-anechoic chamber, providing a semi-free field environment for testing wheel-rail radiated noise of the scaled-down train in operation, while isolating it from external vibrations and noise. It can accurately measure the actual magnitude of wheel-rail vibration and rolling radiated noise of the scaled-down train-track model during operation, thus providing a platform for evaluating and developing vibration and noise reduction technologies for rail transit.

Description

Technical Field

[0001] This invention relates to the field of rail transit technology, and in particular to a rail transit vibration reduction and noise reduction technology evaluation and R&D system platform. Background Technology

[0002] Rail transit refers to a type of transportation or system where vehicles operate on specific tracks. The most typical rail transit system is the railway system, composed of traditional trains and standard railway lines. With rapid socio-economic development, people's demands for railway transportation have increased beyond just higher speeds; they also require greater passenger comfort. Simultaneously, as railway mileage continues to increase, the environmental impact of railway transportation is also growing, with the most prominent issues being the environmental vibration and noise generated during railway operation. Therefore, the evaluation and development of vibration and noise reduction technologies have become increasingly urgent needs in order to improve passenger comfort and reduce environmental vibration and noise generated during train operation.

[0003] One existing method for evaluating vibration and noise reduction technology involves on-site measurement of a test track section after vibration and noise reduction measures have been implemented. This method requires constructing the track structure on-site before and after the implementation of vibration and noise reduction measures. When a train passes through this section, the amount of vibration and noise reduction achieved through on-site measurements is evaluated. However, because this method requires constructing the track structure on-site before and after the implementation of vibration and noise reduction measures, it is not only time-consuming but also prohibitively expensive. Furthermore, once the track structure is determined, it is difficult to change, significantly increasing the difficulty of the experiment.

[0004] Another existing method for evaluating vibration and noise reduction technologies is the scaled-down model experiment. This method involves constructing a scaled-down version of the train and track structure and comparing the track structure before and after the train passes through where vibration and noise reduction measures were implemented. The effect of vibration and noise reduction on the scaled-down model is evaluated, and finally, the amount of vibration and noise reduction achieved on the actual track structure is assessed using a conversion method based on a certain ratio. While this method overcomes the drawbacks of high cost and difficulty in changing track structure in rail transit test sections, the scaled-down design places higher demands on external environmental vibration and noise isolation, making it more susceptible to external influences during testing. The main disadvantage of the scaled-down model experiment is that it cannot provide the semi-free field environment required for testing wheel-rail radiated noise during operation, and therefore cannot fully measure the actual magnitude of wheel-rail vibration and rolling radiated noise, resulting in significant errors in the test results.

[0005] Existing anechoic chambers are mainly used for acoustic experiments and noise testing. They can isolate the effects of external noise and vibration, thus accurately testing the noise levels of products such as automobiles, audio equipment, electronic products, and musical instruments. For example, Chinese patent application publication number CN110469148A discloses an acoustic laboratory for testing the vibration and noise of vehicle powertrain systems, but this is limited to testing the vehicle powertrain system within the acoustic laboratory. Similarly, Chinese patent authorization publication number CN104453288B discloses a micro-vibration test chamber for spacecraft interference sources, which is also limited to testing spacecraft within the test chamber. It is evident that existing technologies do not yet include the integration of anechoic chambers with rail transit lines and trains. Summary of the Invention

[0006] The purpose of this invention is to provide a system platform for evaluating and developing vibration and noise reduction technologies for rail transit, in order to solve the problems existing in the prior art. By connecting a semi-anechoic chamber to a tunnel and setting up a simulated track for a scaled-down train inside, it can provide a semi-free field environment for testing wheel-rail radiated noise of a scaled-down train in operation, and isolate the influence of external vibration and noise. It can accurately test the actual magnitude of wheel-rail radiated noise, thereby providing a platform for evaluating and developing vibration and noise reduction technologies for rail transit.

[0007] To achieve the above objectives, the present invention provides the following solution:

[0008] This invention provides a system platform for evaluating and developing vibration and noise reduction technology for rail transit, including a semi-anechoic chamber, a tunnel, a simulated track, and a scaled-down train running on the simulated track. The tunnel is enclosed by sound-absorbing panels. The side wall of the semi-anechoic chamber has a doorway, and the exit of the tunnel is connected to the doorway. The entrance of the tunnel is located at the end of the tunnel away from the semi-anechoic chamber. The simulated track extends continuously from the outside of the tunnel through the entrance, the exit, and the doorway into the semi-anechoic chamber. The semi-anechoic chamber has a simulated semi-free space for testing the vibration and noise of the scaled-down train passing through the simulated semi-free space.

[0009] Preferably, both the semi-anechoic chamber and the passage tunnel are rectangular structures. The passage tunnel is located on the short side of the corner of the semi-anechoic chamber, and the simulated track is arranged along the diagonal direction of the semi-anechoic chamber. Alternatively, the passage tunnel is located on the short side of the semi-anechoic chamber, and the simulated track is arranged along the long side of the semi-anechoic chamber.

[0010] Preferably, the length, width, and height dimensions of the tunnel are all smaller than those of the semi-anechoic chamber.

[0011] Preferably, a detachable wall is provided at the doorway, the detachable wall has the same structure as the original wall of the semi-anechoic chamber, wheels are provided at the bottom of the detachable wall, and the simulated track at the doorway adopts a detachable structure. By disassembling the simulated track and installing the detachable wall, the semi-anechoic chamber restores its original function.

[0012] Preferably, the semi-anechoic chamber includes an inner suite and an outer suite without rigid connection, and a rubber vibration isolator is provided between the inner suite and the outer suite. The rubber vibration isolator is located under the floor of the inner suite and is used to support the inner suite.

[0013] Preferably, the inner suite is constructed from spliced ​​metal sound insulation and sound absorption modules, which constitute a self-supporting structure of the inner suite. Each metal sound insulation and sound absorption module includes a first wedge and a connecting structure connecting the first wedge. The outer suite is constructed from spliced ​​low-frequency sound-absorbing and sound-insulating panels.

[0014] Preferably, a soundproof door is provided on the side of the semi-anechoic chamber, and the soundproof door is away from the doorway and close to the end of the simulated track.

[0015] Preferably, the soundproof door includes an outer fireproof soundproof door and an inner soundproof and sound-absorbing door. The fireproof soundproof door opens from the inside out, and the soundproof and sound-absorbing door opens from the outside in. A second wedge is provided on the inner surface of the soundproof and sound-absorbing door. The cavity between the second wedge and the soundproof and sound-absorbing door is decorated with a frame and a sound-absorbing panel to form an integrated soundproof and sound-absorbing door.

[0016] Preferably, the soundproof and sound-absorbing door is provided with a bushing at the door hinge, the bushing is rotatably mounted on the bushing bracket, the top end of the bushing bracket is fixed to the wall by a cantilever, the bottom end of the bushing bracket is fixed to the ground, the second wedge has the same shape as the first wedge, and when the soundproof and sound-absorbing door is closed, the second wedge and the first wedge are flush and do not interfere with each other.

[0017] Preferably, the system includes an air conditioning ventilation module, which is equipped with a two-stage silencer, including a primary silencer installed in the air-conditioned room and a secondary silencer installed at the location where the air duct enters the silencer chamber.

[0018] The present invention achieves the following technical effects compared to the prior art:

[0019] (1) By connecting the semi-anechoic chamber to the tunnel and setting up a simulated track for a scaled train inside it, the present invention can combine the simulated track with the semi-anechoic chamber, provide a semi-free field environment for testing wheel-rail radiated noise of the scaled train in operation, and isolate the influence of external vibration and noise, so as to completely and accurately test the actual magnitude of wheel-rail vibration and rolling radiated noise of the scaled train-track model in operation, thereby providing a platform for the evaluation and research and development of vibration reduction and noise reduction technology for rail transit.

[0020] (2) The present invention sets the simulated track along the diagonal direction of the semi-anechoic chamber, which can maximize the use of the internal space of the semi-anechoic chamber, extend the laying length of the simulated track, and ensure the maximum space utilization rate within a limited space.

[0021] (3) The present invention has a detachable wall at the doorway connecting the semi-anechoic chamber and the tunnel. At the same time, the simulated track at the doorway adopts a detachable structure. The detachable wall can be used to open or close the doorway. When conducting rail transit-related experiments, the doorway can be opened to facilitate the passage of scaled-down trains. When conducting experiments inside the semi-anechoic chamber, the doorway can be closed without affecting the sound absorption and sound insulation of the semi-anechoic chamber. In addition, wheels are provided at the bottom of the detachable wall to facilitate movement and thus facilitate the opening and closing of the doorway.

[0022] (4) The semi-anechoic chamber of the present invention includes an inner chamber and an outer chamber without rigid connection, and is supported under the floor of the inner chamber by rubber vibration isolators, which can effectively isolate external solid sound transmission and further improve the accuracy of the test.

[0023] (5) The present invention has a soundproof door on the side of the semi-anechoic chamber, which can be opened when needed for convenient passage and closed during the test to effectively isolate noise. At the same time, the soundproof door is located far away from the doorway and close to the end of the simulated track, which can minimize the impact of opening the soundproof door on the test process. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a top view of the overall structure of the present invention;

[0026] Figure 2 for Figure 1 Schematic diagram of each track structure;

[0027] Figure 3 for Figure 1 Schematic diagram of PP structure;

[0028] Figure 4 for Figure 1 Schematic diagram of the NN structure;

[0029] Figure 5 for Figure 1 Schematic diagram of the MM structure;

[0030] Figure 6 for Figure 1 Schematic diagram of the structure at point Q;

[0031] Figure 7 for Figure 1 Arrangement diagram of the first wedge on the AB side;

[0032] Figure 8 for Figure 1 Arrangement diagram of the first wedge on the BC surface;

[0033] Figure 9 for Figure 1 Arrangement diagram of the first wedge on the CD surface;

[0034] Figure 10 for Figure 1 Arrangement diagram of the first wedge on the DA surface;

[0035] Figure 11 This is a diagram showing the arrangement of the first wedge on the top surface of the semi-anechoic chamber of the present invention;

[0036] Among them, 1. Semi-anechoic chamber; 11. Outer suite; 12. Inner suite; 121. First wedge; 13. Soundproof door; 131. Fireproof soundproof door; 132. Soundproof and sound-absorbing door; 133. Bushing support; 14. Demountable wall; 141. Second wedge; 15. Doorway; 16. Light box; 2. Passing tunnel; 3. Simulated track; 31. Rail; 32. Scaled-down train; 33. Support; 4. Curved track; 5. Straight track. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] The purpose of this invention is to provide a system platform for evaluating and developing vibration and noise reduction technologies for rail transit, in order to solve the problems existing in the prior art. By connecting a semi-anechoic chamber to a tunnel and setting up a simulated track for a scaled-down train inside, it can provide a semi-free field environment for testing wheel-rail radiated noise of a scaled-down train in operation, and isolate the influence of external vibration and noise. It can completely and accurately test the actual magnitude of wheel-rail radiated noise, thereby providing a platform for evaluating and developing vibration and noise reduction technologies for rail transit.

[0039] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0040] like Figures 1-11As shown, this invention provides a system platform for evaluating and developing vibration and noise reduction technology for rail transit, including a semi-anechoic chamber 1, a tunnel 2, and a simulated track 3. The semi-anechoic chamber 1 can be constructed using existing technology, and is equipped with sound-insulating and sound-absorbing materials except for the ground surface; it is an anechoic chamber with the floor as the reflective surface. The tunnel 2 is enclosed by sound-insulating and sound-absorbing panels; the specific materials can be selected according to actual needs. Its main function is sound insulation and noise reduction, acting as a large silencer to reduce external ventilation noise and provide space for the scaled-down train 32 to pass through. A doorway 15 is provided on the side wall of the semi-anechoic chamber 1, and the exit of the tunnel 2 connects to the doorway 15. The entrance of the tunnel 2 is located at the end of the tunnel 2 furthest from the semi-anechoic chamber 1, meaning the tunnel 2 and the semi-anechoic chamber 1 are connected through the doorway 15. The simulated track 3 extends from the outside of the tunnel 2, through the entrance and exit of the tunnel 2, and through the doorway 15 into the semi-anechoic chamber 1. The simulated track 3 is used to run the scaled-down train 32. The simulated track 3 can also have other deformable structures. For example, the curvature of the simulated track 3 can be changed to form another curved track 4, or a straight track 5 can be set as needed. Of course, the straight track 5 can lead into the semi-anechoic chamber 1 or not. Thus, the scaled-down train 32 can start and accelerate on the outer part of the simulated track 3, reach the set speed after entering the semi-anechoic chamber 1 to conduct relevant tests, and then decelerate and stop inside the semi-anechoic chamber 1. By connecting the through tunnel 2 at the doorway 15 of the semi-anechoic chamber 1, the weakening of the sound insulation and noise reduction effect of the semi-anechoic chamber 1 caused by directly opening the doorway 15 on the semi-anechoic chamber 1 can be avoided, thus preventing the acquisition of accurate test data. Therefore, this invention connects a semi-anechoic chamber 1 to a tunnel 2 and sets up a simulated track 3 for a scaled-down train 32 inside the tunnel. The simulated track 3 passes through a simulated semi-free space within the semi-anechoic chamber 1, allowing for testing of the vibration and noise of the scaled-down train 32 as it passes through the simulated semi-free space. The simulated semi-free space refers to the presence of sound wave reflection at the boundary of the semi-anechoic chamber 1. A semi-ellipsoidal space with the center of the semi-anechoic chamber 1 as the origin can be considered a standard semi-free field, providing the semi-free field environment required for testing the wheel-rail radiated noise of the running scaled-down train 32. If this range is exceeded, there will be a problem of superposition of reflected waves, leading to distorted results. Therefore, by forming a semi-free field environment, the influence of external vibration and noise can be isolated, enabling a completely accurate test of the actual magnitude of wheel-rail vibration and rolling radiated noise of the scaled-down train-track model under operating conditions. This provides a platform for the evaluation and research and development of vibration reduction and noise reduction technologies for rail transit.

[0041] like Figure 3As shown, the simulated track 3 may include supports 33, which are continuously arranged as a support structure. Parallel steel rails 13 are laid on the supports 33, and the scaled-down train 32 runs on the steel rails 13. To facilitate adjustment of the direction of the steel rails 13 or to facilitate installation and removal of certain parts, the supports 33 may be fixed to the ground in a detachable manner.

[0042] like Figure 1 , Figures 4-5 As shown, for ease of construction and application, both the semi-anechoic chamber 1 and the through tunnel 2 can be designed as rectangular structures. The semi-anechoic chamber 1 is combined with the simulated track 3 (a scaled-down model of the track) through the rectangular through tunnel 2, achieving the purpose of providing a semi-free field environment for the simulated track 3 and its scaled-down train 32 within the semi-anechoic chamber 1. The through tunnel 2 can be located at a corner of the semi-anechoic chamber 1, fitting snugly against its shorter side. In this case, when setting up the simulated track 3, it can be positioned along the diagonal of the semi-anechoic chamber 1, thereby maximizing the utilization of the internal space of the semi-anechoic chamber 1 and extending the laying length of the simulated track 3 under the same conditions, ensuring maximum space utilization within a limited space. Alternatively, if space permits, the through tunnel 2 can be located at any position on the shorter side of the semi-anechoic chamber 1, with the simulated track 3 positioned along the longer side of the semi-anechoic chamber 1. As can be seen from the above, when arranged along the long side, the maximum braking distance is half the length of the long side of the semi-anechoic chamber 1, that is, it decelerates immediately after passing the midpoint; when arranged along the diagonal, the maximum braking distance is half the length of the diagonal, which is longer than the long side. Therefore, the corresponding maximum speed is also higher, so vibration and noise at higher speeds can be measured.

[0043] The length, width, and height of the tunnel 2 are all smaller than those of the semi-anechoic chamber 1. In other words, the tunnel 2 is a relatively small space structure built outside and connected to the semi-anechoic chamber 1. The size of the doorway 15 should be minimized to ensure that the scaled-down train 32 and the simulated track 3 can pass through smoothly. This can minimize the impact of the size of the doorway 15 on the test data and also save on construction costs.

[0044] A removable wall 14 can be installed at doorway 15, and the simulated track 3 at doorway 15 also adopts a removable structure. The removable simulated track 3 can be set up as follows: each track slab is 6 meters long, 2.8 meters wide, and approximately 0.3 to 0.5 meters thick. To eliminate boundary effects, three track slabs are typically laid continuously in the semi-anechoic chamber 1, with steel rails 31 placed on top and fasteners installed for assembly. Excitation is applied by manually striking the steel rails 31 with a hammer. Generally, the amplitude and spectrum of the excitation force generated by the hammer are relatively stable and can be considered a standard excitation load. Thus, by testing the vibration and noise levels of different track structures under the standard load generated by the hammer, the vibration reduction and noise reduction effects of different track structures can be evaluated. The removable wall 14 has the same structure as the original wall of the semi-anechoic chamber 1. The removable wall 14 allows the doorway 15 to be opened or closed. During rail transit-related experiments (such as vibration and noise testing of a scaled-down model), the doorway 15 can be opened to allow the scaled-down train 32 to pass through. When only tests are conducted inside the semi-anechoic chamber 1 (such as full-scale tests of some track structures), the doorway 15 can be closed without affecting the sound absorption and insulation of the semi-anechoic chamber 1. Furthermore, wheels can be installed at the bottom of the removable wall 14 to facilitate overall repositioning, which also facilitates the opening and closing of the doorway 15.

[0045] The semi-anechoic chamber 1 may include an inner chamber 12 and an outer chamber 11 without rigid connection. A rubber vibration isolator is provided between the inner chamber 12 and the outer chamber 11. The rubber vibration isolator is located under the floor of the inner chamber 12 and is used to support the inner chamber 12. The above arrangement can effectively isolate external solid-borne sound and further improve the accuracy of the test.

[0046] Combination Figures 7-11 As shown, the inner suite 12 can be constructed from assembled metal sound-insulating and sound-absorbing modules (including four walls and a ceiling panel, with a light box 16 installed on the ceiling panel). These metal sound-insulating and sound-absorbing modules form a self-supporting structure for the inner suite 12, eliminating the need for a separate, complex steel frame support system. Each metal sound-insulating and sound-absorbing module can include a first wedge 121 and a connecting structure connecting the first wedge 121. It is installed and fixed using guide rails and keel supports. It should be noted that the installation structure and method can utilize existing technology, following... Figures 7-11 The installation is carried out according to the layout shown in the diagram, and will not be described in detail here. The outer suite 11 can be constructed by splicing low-frequency sound-absorbing and sound-insulating panels (including the four walls and the ceiling). Low-frequency sound-absorbing and sound-insulating panels can be moved easily without affecting the acoustic characteristics. Furthermore, low-frequency sound-absorbing and sound-insulating panels combine low-frequency sound absorption and sound insulation, and have a sound insulation capacity comparable to some brick walls, but are lighter and do not require complex foundation design.

[0047] like Figure 1 and Figure 6As shown, a soundproof door 13 can be installed on the side of the semi-anechoic chamber 1. This door can be opened when needed for easy passage and closed during the test to effectively isolate noise. Furthermore, the soundproof door 13 is positioned away from the doorway 15 and close to the end of the simulation track 3 to minimize the impact of opening the soundproof door 13 on the test process. Depending on the access equipment or personnel, the soundproof door 13 can be configured as a single door or a double door. For example, ... Figure 1 The soundproof door 13 has double doors on sides A and B, and single doors on sides B and C. The soundproof door 13 opens and closes easily and can stop at any angle. The soundproof door 13 has no threshold (the ground is completely flush with both indoor and outdoor floors), enabling barrier-free passage and facilitating the entry and exit of personnel and equipment.

[0048] The soundproof door 13 may include an outer fireproof soundproof door 131 and an inner soundproof and sound-absorbing door 132. The fireproof soundproof door 131 opens from the inside out, while the soundproof and sound-absorbing door 132 opens from the outside in. A second wedge 141 may be provided on the inner surface of the soundproof and sound-absorbing door 132. The cavity between the second wedge 141 and the soundproof and sound-absorbing door 132 is decorated with a frame and sound-absorbing panels to form an integrated soundproof and sound-absorbing door 132. A floor support and a bridge floor are installed on the ground between the two doors (the outer fireproof soundproof door 131 and the inner soundproof and sound-absorbing door 132), and metal sound-absorbing panels are installed on both sides and the top to form a sound-absorbing sound lock.

[0049] Regarding the specific installation method of the soundproof and sound-absorbing door 132, a bushing can be provided at the hinge of the soundproof and sound-absorbing door 132. The bushing is rotatably mounted on the bushing bracket 133, allowing the soundproof and sound-absorbing door 132 to rotate freely around the bushing bracket 133. The top end of the bushing bracket 133 is fixed to the wall via a cantilever, and the bottom end of the bushing bracket 133 is fixed to the ground, forming a vertical rotation support shaft that can support the entire soundproof and sound-absorbing door 132. The second wedge 141 can have the same shape as the first wedge 121. When the soundproof and sound-absorbing door 132 is closed, the second wedge 141 and the first wedge 121 are flush and do not interfere with each other. Furthermore, when the soundproof and sound-absorbing door 132 is open, it does not occupy the doorway space.

[0050] It includes an air conditioning ventilation module, which is equipped with two-stage silencers: a primary silencer installed in the air-conditioned room and a secondary silencer installed at the entrance of the air duct into the silencer chamber.

[0051] The present invention also provides a specific embodiment of a rail transit vibration reduction and noise reduction technology evaluation and R&D system platform, as follows:

[0052] The system platform includes: a semi-anechoic chamber 1, a soundproof door 13, a passage tunnel 2, an air conditioning and ventilation module, a lighting module, and a system monitoring module.

[0053] The semi-anechoic chamber 1 has external dimensions of 22m * 12.5m * 6m (length * width * height), making it the largest semi-anechoic chamber 1 currently used in China for testing and evaluating vibration reduction and noise reduction performance in rail engineering. To meet the system platform's requirements for the free field, the anechoic module uses metal sound-absorbing wedges (first wedge 121 and second wedge 141) with the longest lifespan and best acoustic performance. The platform is designed, manufactured, and installed based on a prefabricated concept. After installation, the clear dimensions of the first wedge 121 from tip to tip are 20m * 10.4m * 5m (length * width * height), the free field radius can reach approximately 8 meters along the major axis and is not less than 3 meters along the minor axis, and the cutoff frequency of semi-anechoic chamber 1 is no higher than 63Hz.

[0054] The semi-anechoic chamber 1 is constructed using CA-specific sound insulation modules, including an inner suite 12 and an outer suite 11. The inner suite 12 includes a metal sound insulation and sound absorption module and a soundproof door 13, which effectively isolates external solid-borne sound.

[0055] In the inner suite 12 structure, the metal sound insulation and absorption modules and special connectors constitute the self-supporting structure of the inner suite 12, eliminating the need for a separate complex steel frame support system. The entire inner suite 12 is supported by rubber vibration isolators arranged under the floor of the inner suite 12. The inner suite 12 is not rigidly connected to the outer suite 11, effectively isolating external solid-borne sound. The metal sound insulation and absorption modules include: a 900mm long CAMW900 first wedge 121 (metal wedge), a 50mm cavity, a low-frequency sound-absorbing and sound-insulating panel, CA special mounting rails, and a keel support. It can achieve a 63Hz free field radius of ≥8m in the major axis direction and ≥3m in the minor axis direction in the semi-anechoic chamber 1. The first wedge 121 installation node uses 40 brackets, channel steel, 40 angle steel, and M6×10 spiral. CA special installation guide rails are installed on the keel support. The first wedge 121 is locked in the guide rail slot with locking bolt assembly at the bottom. The bottom of the first wedge 121 adopts an anti-slip design to prevent the first wedge 121 on the roof from falling out of the guide rail.

[0056] In the structure of the outer suite 11, the outer suite 11 consists of four walls and a ceiling. The material is made of CAIA45-L low-frequency sound-absorbing and sound-insulating board, which can be moved to a different location without affecting the acoustic characteristics. The low-frequency sound-absorbing and sound-insulating board takes into account both low-frequency sound absorption and sound insulation, and has the same sound insulation capacity as some brick walls, but is lighter and does not require complex foundation design.

[0057] The soundproof door 13 is a double-layered, sound-lock type, rotating steel soundproof door. A second wedge 141 is installed on the inner surface of the soundproof door 13. The clearance dimensions for equipment passage are: width × height = 2500mm × 2600mm, and the clearance dimensions for personnel passage are: width × height = 800mm × 1000mm. The outer layer of the soundproof door 13 is fitted with a CAAD43 steel fireproof soundproof door 131, opening from the inside out, with a sound insulation of 43dB. The inner layer is fitted with a CAAD40 steel sound-absorbing door 132, opening from the outside in, with a sound insulation of 40dB. The soundproof door 13 opens and closes easily and can stop at any angle. The soundproof door 13 has no threshold (no protrusions on the ground, completely flush with the indoor and outdoor ground), enabling unobstructed passage and facilitating personnel access. A floor support frame and a bridge floor are installed between the double doors, and metal sound-absorbing panels are installed on both sides and the top to form a sound-absorbing sound lock.

[0058] The door hinge of the soundproof and sound-absorbing door 132 is mounted on a bushing bracket 133 (instead of on the wall). The upper end of the bushing bracket 133 is fixed to the wall, and the lower end is fixed to the ground via foot anchors. The central axis of the bushing bracket 133 is connected to the door hinge via a rolling bearing. The cavity between the soundproof door 13 and the second wedge 141 is decorated with a frame and sound-absorbing panels to form an integrated soundproof and sound-absorbing door 132. The second wedge 141 is flush with the first wedge 121 when the soundproof door 13 is closed, and has the same shape as the first wedge 121. The opening trajectory and rotation radius of the soundproof door 13 do not interfere with each other. The soundproof door 13 is designed in three dimensions and rotates 180° or 90° after opening, without occupying doorway space.

[0059] The tunnel 2 acts as a large silencer, reducing external ventilation noise and providing space for the scaled-down train 32. A removable wall 14 is installed at the doorway 15. When the scaled-down train 32 needs to pass through, this removable wall 14 and its second wedge 141 are removed to facilitate passage. When passage is not required, the removable wall 14 and its second wedge 141 are restored without affecting the sound absorption and insulation of the semi-anechoic chamber 1. The tunnel 2 measures 5.25m * 5.8m * 3m and has a sound insulation of approximately 40dB. Through the tunnel 2, the semi-anechoic chamber 1 is combined with the simulated track 3, achieving the purpose of providing a free-field boundary for the scaled-down model.

[0060] The air conditioning and ventilation module includes a chiller / heater unit, an air cooler unit, an electric heater unit, a control system, temperature sensors, air ducts and vents, and a ventilation silencer; indoor ventilation is designed for a ventilation volume of 6 cycles per hour, with a net indoor volume of 1000 m³. 3 Maximum circulating air volume 6000m³ 3 / h, depending on the season, turn on cooling or heating, adjust the indoor temperature (20~26)℃, relative humidity (30~90)%, and the number of fresh air exchanges is not less than 5 times / hour.

[0061] The air conditioning ventilation module operates as follows: 1) When there is no heat generated by equipment operation inside the semi-anechoic chamber 1, it operates in closed-loop mode with a small amount of fresh air added to meet the measurement requirements and preparation stage environment. 2) When the outdoor temperature is between 20 and 25°C, it operates in 100% fresh air mode, with both cooling and heating units shut down, using outdoor air to regulate the indoor temperature. 3) When the outdoor temperature is above 25°C, the cooling unit is turned on, primarily using recirculated air to regulate the indoor temperature; fresh air and exhaust air can be turned on as needed. 4) When the outdoor temperature is below 20°C, the electric heating unit is turned on, primarily using recirculated air to regulate the indoor temperature; fresh air and exhaust air can be turned on as needed. The above operating states are automatically achieved through the control system and temperature sensors. The control system automatically controls the airflow and cooling (heating) capacity based on the indoor temperature to achieve energy-saving temperature control. All operations are performed through a touchscreen with animated displays, enabling human-machine interaction. The air conditioning unit consists of a mixing section, a cooling coil section, and a fan section.

[0062] The ventilation silencer is equipped with two stages of silencers in the supply and return air ducts: a first-stage silencer, model CAVS, with dimensions of 800mm×800mm×2000mm, is installed in the air-conditioned room; and a second-stage silencer, model CAVSF, with dimensions of 800mm×800mm×2000mm, is installed at the point where the air duct enters the semi-anechoic chamber 1.

[0063] The lighting module includes lamps, an emergency alarm system and emergency lighting, and an integrated power distribution interface.

[0064] The lighting fixtures use low-noise, high-brightness, energy-saving LED lights, mounted on dedicated sound-absorbing brackets. The LED tubes are installed on the ceiling of the semi-anechoic chamber 1 in a distributed arrangement of 6 rows x 3 columns. With all indoor lights on, the indoor illuminance is no less than 500 lux (measured at a distance of 1.0m from the ground grid). The lighting fixtures are configured with two groups: high-brightness and standard brightness, controlled by these groups. The lifespan of the LED lights is no less than 5000 hours.

[0065] The luminaires are small in size, with a diameter of 30mm, minimizing interference with the free field and producing low noise. After installation, the semi-anechoic chamber 1 still meets the free field accuracy and background noise requirements specified in ISO 3745. An emergency alarm system and a lighting system with emergency power supply are installed above the access door of the semi-anechoic chamber 1. These systems can operate normally and continuously for at least one hour in the event of a power outage or other malfunction that cuts off the overall power supply to the semi-anechoic chamber 1. Safety indicator lights are installed outside the access door to indicate the working status inside the semi-anechoic chamber 1. All lighting fixtures do not affect the free sound field characteristics of the semi-anechoic chamber 1 and do not generate noise.

[0066] All power distribution interfaces within the semi-anechoic chamber 1 are integrated onto a single component (variable frequency power input, with both three-phase and single-phase interfaces), and a mains power interface is also provided; all power cable entry holes are soundproofed. In addition to a single-phase 30kVA instrument and lighting power supply, a sample junction box is provided inside, including two 10A three-prong sockets and two 10A two-prong sockets. The sockets are floor-mounted, with conduits pre-buried during flooring installation and all grounded. Two 110V, 220V, and 380V main sockets are also provided. A distribution box and circuit breaker are installed in the control room. Lightning protection complies with GB50057, and internal metal cable trays, pipes, and metal structures are equipotentially bonded and grounded.

[0067] The system monitoring module includes a fire alarm system and a monitoring system.

[0068] The fire alarm system is equipped with both heat and smoke detectors, and is linked to the fire suppression system. The automatic fire alarm system includes two Honeywell smoke detectors. The Honeywell XLS smoke detectors have five selectable sensitivity settings, with a minimum protection radius of 4.55m when ceiling-mounted. The room's fire suppression system includes two portable dry powder extinguishers, specifically the MF ABC4 ammonium phosphate dry powder extinguisher, each weighing 23kg, with a maximum protection distance of 20m, located at the room entrance.

[0069] The monitoring system is equipped with four cameras. Two of these cameras are equipped with pan-tilt units and automatic zoom lenses, with motorized optical zoom lenses offering magnification of 10× to 50×. The other two cameras are equipped with wide-angle lenses or manual zoom lenses, suitable for low-light environments. The pan-tilt units can achieve 270-degree planar rotation and vertical viewing angle adjustment. An outdoor LCD monitor and a controller are installed to switch between multiple camera feeds and store video data via the controller's CD burner. A two-way intercom system connects the semi-anechoic chamber 1 to the control room, enabling communication between the two spaces. The system includes internal and external communication facilities, comprehensive video surveillance, and a distress alarm system.

[0070] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A system platform for evaluating and developing vibration reduction and noise reduction technologies for rail transit, characterized in that: The semi-anechoic chamber, the passing tunnel, the simulation track and the scaled train running on the simulation track, the passing tunnel is surrounded by sound insulation and absorption board, the side wall of the semi-anechoic chamber is provided with a door hole, the outlet of the passing tunnel is communicated with the door hole, the inlet of the passing tunnel is arranged at the end of the passing tunnel away from the semi-anechoic chamber, the simulation track is arranged from the outside of the passing tunnel through the inlet, the outlet, the door hole to the semi-anechoic chamber, the semi-anechoic chamber has a simulated semi-free space, the vibration and noise of the scaled train passing through the simulated semi-free space are tested. The semi-anechoic chamber and the passing tunnel are rectangular structures, the passing tunnel is arranged on the short side of the corner of the semi-anechoic chamber, or the passing tunnel is arranged on the short side of the semi-anechoic chamber, and the simulation track is arranged along the diagonal direction of the semi-anechoic chamber. The semi-anechoic chamber comprises an inner sleeve room and an outer sleeve room without rigid connection, and the material constituting the outer sleeve room comprises low-frequency sound absorption and insulation board.

2. The rail transit vibration and noise reduction technology evaluation and research and development system platform of claim 1, wherein: The length, width and height of the passing tunnel are smaller than the length, width and height of the semi-anechoic chamber.

3. The rail transit vibration and noise reduction technology evaluation and research and development system platform of claim 2, wherein: A detachable wall is arranged at the door hole, the detachable wall has the same structure as the original wall of the semi-anechoic chamber, the bottom of the detachable wall is provided with a wheel, and the simulation track at the door hole adopts a detachable structure, so that the semi-anechoic chamber restores the original function by detaching the simulation track and installing the detachable wall.

4. The rail transit vibration and noise reduction technology evaluation and research and development system platform according to any one of claims 1-3, characterized in that: A rubber vibration isolator is arranged between the inner sleeve room and the outer sleeve room, and the rubber vibration isolator is located below the floor of the inner sleeve room and used for supporting the inner sleeve room.

5. The rail transit vibration and noise reduction technology evaluation and research and development system platform of claim 4, wherein: The inner sleeve room is spliced by metal sound insulation and absorption modules, the metal sound insulation and absorption modules constitute a self-supporting structure of the inner sleeve room, the metal sound insulation and absorption modules comprise a first wedge and a connecting structure connected with the first wedge, and the outer sleeve room is spliced by low-frequency sound absorption and insulation boards.

6. The rail transit vibration and noise reduction technology evaluation and research and development system platform of claim 5, wherein: A sound insulation door is arranged on the side of the semi-anechoic chamber, the sound insulation door is away from the door hole and close to the end of the simulation track.

7. The rail transit vibration and noise reduction technology evaluation and research and development system platform of claim 6, wherein: The sound insulation door comprises an outer fireproof sound insulation door and an inner sound insulation and absorption door, the fireproof sound insulation door is opened from inside to outside, the sound insulation and absorption door is opened from outside to inside, a second wedge is arranged on the inner surface of the sound insulation and absorption door, and the cavity between the second wedge and the sound insulation and absorption door is decorated by a framework and sound absorption board to form an integrated sound insulation and absorption door.

8. The rail transit vibration and noise reduction technology evaluation and research and development system platform of claim 7, wherein: A shaft sleeve is arranged at the door shaft of the sound insulation and absorption door, the shaft sleeve is rotationally arranged on a shaft sleeve support, the top end of the shaft sleeve support is fixed to the wall through a cantilever, the bottom end of the shaft sleeve support is fixed to the ground, the second wedge has the same shape as the first wedge, and the second wedge is flush with the first wedge when the sound insulation and absorption door is closed, and the second wedge does not interfere with the first wedge.

9. The rail transit vibration and noise reduction technology evaluation and research and development system platform of claim 1, wherein: The air conditioning and ventilation module is provided with two-stage silencers, comprising a first-stage silencer installed in an air conditioner indoor and a second-stage silencer installed at the position where the air pipe enters the anechoic chamber.

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