A movable guard for a rotational speed test bench

Abstract

The utility model discloses a movable protective cover of rotational speed test platform, including device body, device body includes protective cover device and cover body movement adjusting device, and cover body movement adjusting device is welded in protective cover device inside bottom end, cover body movement adjusting device includes first welding station, second welding station, third welding station, fourth welding station, fifth welding station and universal wheel, and first welding station is located second welding station left side, and third welding station is located first welding station front side, and fourth welding station is located third welding station right side, and fifth welding station is located fourth welding station front side, and universal wheel is equipped with five and five universal wheels are fixed respectively through screw on first welding station, second welding station, third welding station, fourth welding station and fifth welding station. This kind of device can realize 360 degree free movement through pushing protective cover, and the protective demand of adapting to different test platform position, work piece specification is reduced, and manpower cost and operation time -consuming.

Description

Technical Field

[0001] This utility model relates to the technical field of protective covers for speed testing benches, specifically a movable protective cover for a speed testing bench. Background Technology

[0002] Motor testing utilizes instruments, meters, and related equipment, in accordance with relevant regulations, to inspect the electrical, mechanical, safety, and reliability performance of semi-finished and finished motors, or motor-based supporting products, during the motor manufacturing process. These tests can fully or partially reflect the relevant performance data of the tested motor. This data can be used to determine whether the tested motor meets design requirements, its quality, and the goals and directions for improvement. Motor testing and inspection are indispensable and crucial links in motor research, production, and maintenance. Therefore, for units engaged in motor research, production, or maintenance, possessing a set of compliant motor testing and inspection equipment is essential. Speed ​​test benches generate significant noise during operation, thus requiring the use of protective covers for sound insulation.

[0003] The existing protective covers for speed test benches are large and cannot be easily moved, which has the following drawbacks: Slow emergency response: When equipment malfunctions suddenly (such as abnormal noises or smoke), the protective cover cannot be moved quickly to check the internal situation, which may delay troubleshooting and even increase the risk of safety accidents; Laborious position adjustment: The protective cover needs to be moved manually. Due to its large size and weight, multiple people are needed to move it, increasing labor costs, and improper handling may cause damage to the equipment; Low space utilization: When the speed test bench needs to temporarily free up space (such as for cleaning or moving other equipment), it cannot be flexibly adjusted by moving the protective cover, resulting in limited site planning.

[0004] Therefore, a solution is needed. Utility Model Content

[0005] (a) Technical problems to be solved

[0006] To address the shortcomings of existing technologies, this invention provides a movable protective cover for a speed testing platform, thereby resolving the problems mentioned in the background section.

[0007] (II) Technical Solution

[0008] To achieve the above objectives, this utility model provides the following technical solution: a movable protective cover for a speed testing platform, comprising a device body, the device body including a protective cover assembly and a cover movement adjustment device, the cover movement adjustment device being welded to the bottom of the inner side of the protective cover assembly; the cover movement adjustment device including a first welding platform, a second welding platform, a third welding platform, a fourth welding platform, a fifth welding platform, and casters, the first welding platform being located to the left of the second welding platform, the third welding platform being located in front of the first welding platform, the fourth welding platform being located to the right of the third welding platform, and the fifth welding platform being located in front of the fourth welding platform; five casters are provided, and each of the five casters is secured by screws. Fixed to the first, second, third, fourth, and fifth welding platforms, each of which, along with the caster wheels, has two sets of fixing holes. Connecting stabilizing arms are welded between the first and second welding platforms, between the first and third welding platforms, between the third and fourth welding platforms, and between the fourth and fifth welding platforms. The connecting stabilizing arms are triangular in shape, and their surfaces have several sets of horizontally equidistant stabilizing holes. These stabilizing holes are parallelogram-shaped, and each stabilizing hole contains a stabilizing block, which is also triangular in shape.

[0009] Preferably, the bottom of the first welding station, the second welding station, the third welding station, the fourth welding station, and the fifth welding station are provided with a set of welding feet distributed symmetrically. The welding feet are triangular in shape, and the surface of the welding feet is provided with several sets of reinforcing holes. The reinforcing holes are rectangular in shape, and reinforcing blocks are provided inside the reinforcing holes. The reinforcing blocks are rectangular in shape.

[0010] Preferably, the protective cover device includes a top plate, a front plate, a rear plate, a first side plate, and a second side plate. The top plate, front plate, rear plate, first side plate, and second side plate are smoothly transitioned and integrally formed. The front plate and rear plate are located at the front end and rear end of the bottom of the top plate, respectively. The first side plate and second side plate are located at the left end and right end of the bottom of the top plate, respectively. A motor mounting notch is provided on the right side of the front plate.

[0011] Preferably, the top plate, front plate, rear plate, first side plate and second side plate are all provided with mounting openings, and double-layer observation and soundproof glass is installed in the mounting openings.

[0012] Preferably, the top plate, front plate, rear plate, first side plate and second side plate each include an outer layer plate and an inner layer plate, the outer layer plate is located outside the inner layer plate, and there is a groove between the outer layer plate and the inner layer plate, the groove being filled with sound insulation cotton.

[0013] (III) Beneficial Effects

[0014] The utility model provides a movable protective cover for a rotational speed test bench, having the following beneficial effects:

[0015] In this solution, the movable protective cover of the rotational speed test bench greatly improves the convenience of movement: Without manual handling, a single person can freely move the protective cover 360° by pushing it, adapting to the protection requirements of different test bench positions and workpiece specifications, reducing labor costs and operation time. The test scenario can be quickly adapted: The coverage range of the protective cover can be flexibly adjusted (such as approaching / leaving the rotating part), adapting to rotational speed test benches with different structures such as horizontal and vertical types, or quickly making room during multi-device linkage testing, improving the test efficiency. The emergency response efficiency is improved: When an abnormality occurs during equipment operation (such as part splashing, abnormal noise), the protective cover can be quickly moved to observe the internal situation or perform an emergency shutdown operation, shortening the fault handling time and reducing safety risks. The space utilization is more flexible: When idle, the protective cover can be moved to a corner for storage, reducing the space occupied by the test bench; when transporting or handling the equipment, the protective cover can be moved separately, facilitating the overall loading and unloading of the equipment, and optimizing the warehousing and logistics efficiency. The maintenance and repair costs are reduced: When overhauling the bottom of the test bench, transmission components or replacing cables, the protective cover can be directly moved to expose the operation area, avoiding repeated disassembly and assembly of fixed components such as bolts, reducing maintenance working hours and component wear. The human-machine engineering experience is optimized: The operator can adjust the position of the protective cover according to the observation needs, avoiding blocking the line of sight (such as approaching the observation window to check the rotational speed status), and at the same time, there is no need to bend down or drag forcefully during the movement process, reducing the operation fatigue;

[0016] By setting a cover body movement adjustment device, which includes universal wheels, when a sudden failure occurs in the equipment (such as abnormal noise, smoking), the protective cover can be quickly moved with the help of the universal wheels to check the internal situation, respond to the fault handling in a timely manner, and reduce the risk of safety accidents. Due to the lack of a convenient moving structure in the prior art, it is difficult to quickly move and check. This solution realizes quick movement through universal wheels, improving the emergency response speed;

[0017] The universal wheels of the cover body movement adjustment device enable the protective cover to be moved without manual handling by multiple people. Compared with the manual handling of large-sized and heavy protective covers in the prior art, this solution can be conveniently pushed and moved by a single person using the universal wheels, reducing labor costs and avoiding equipment bumps and damages caused by improper handling, and easily realizing position adjustment;

[0018] Based on the mobility of the cover body movement adjustment device, when the rotational speed test bench needs to temporarily make room (such as for cleaning, handling other equipment), the position can be flexibly adjusted by moving the protective cover, no longer restricted by the difficulty of moving the fixed protective cover, improving the flexibility of site planning, increasing the space utilization rate, and overcoming the problem of limited space planning in the prior art;

[0019] The protective cover's movement adjustment device incorporates a stabilizing arm, stabilizing block, welded feet, and reinforcing blocks, enhancing its stability and preventing deformation or damage during movement. The integrated molding of the protective cover assembly ensures overall structural strength and reliability during movement. A motor mounting notch facilitates motor installation. Double-layered soundproof glass allows for internal observation without moving the cover and also provides sound insulation. The structure of the outer and inner panels with sound-absorbing cotton enhances sound insulation, ensuring ease of use and optimizing the testing environment. Compared to existing technologies, this design offers richer functionality and greater practicality. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0021] Figure 2 This is a schematic diagram of the structure of the cover movement adjustment device of this utility model;

[0022] Figure 3 This is a schematic diagram of the top plate layer structure of this utility model.

[0023] In the diagram: 1. Device body; 2. Protective cover device; 3. Cover movement adjustment device; 4. First welding table; 5. Second welding table; 6. Third welding table; 7. Fourth welding table; 8. Fifth welding table; 9. Casters; 10. Connecting stabilizing arm; 11. Stabilizing hole; 12. Stabilizing block; 13. Fixing hole; 14. Welding foot; 15. Reinforcing hole; 16. Reinforcing block; 17. Top plate; 18. Front plate; 19. Rear plate; 20. First side plate; 21. Second side plate; 22. Mounting port; 23. Double-layer observation soundproof glass; 24. Outer plate; 25. Inner plate; 26. Sound insulation cotton; 27. Hollow groove; 28. Motor mounting notch. Detailed Implementation

[0024] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0025] Please see Figure 1-3 This utility model provides a technical solution:

[0026] Example 1

[0027] To address the aforementioned problems: the existing protective covers of speed test benches are large and cannot be easily moved, resulting in the following drawbacks: Slow emergency response: When equipment malfunctions suddenly (such as abnormal noises or smoke), the protective cover cannot be quickly moved to inspect the internal condition, potentially delaying troubleshooting and even increasing the risk of safety accidents; Laborious repositioning: The protective cover needs to be manually moved, and due to its large size and weight, multiple people are required to move it, increasing labor costs and potentially causing damage to the equipment due to improper handling; Low space utilization: When the speed test bench needs to temporarily free up space (such as for cleaning or moving other equipment), it cannot be flexibly adjusted by moving the protective cover, leading to limitations in site planning.

[0028] The solution is as follows: A movable protective cover for a speed testing bench includes a device body 1. The device body 1 includes a protective cover device 2 and a cover movement adjustment device 3. The cover movement adjustment device 3 is welded to the bottom of the inner part of the protective cover device 2. The cover movement adjustment device 3 includes a first welding platform 4, a second welding platform 5, a third welding platform 6, a fourth welding platform 7, a fifth welding platform 8, and casters 9. The first welding platform 4 is located to the left of the second welding platform 5, the third welding platform 6 is located in front of the first welding platform 4, the fourth welding platform 7 is located to the right of the third welding platform 6, and the fifth welding platform 8 is located in front of the fourth welding platform 7. Five casters 9 are provided, and the five casters 9 are respectively fixed to the first welding platform 4 and the second welding platform 5 by screws. On the third welding station 6, the fourth welding station 7, and the fifth welding station 8, and on the first welding station 4, the second welding station 5, the third welding station 6, the fourth welding station 7, the fifth welding station 8, and the caster wheel 9, two sets of fixing holes 13 are provided. Connecting stabilizing arms 10 are welded between the first welding station 4 and the second welding station 5, between the first welding station 4 and the third welding station 6, between the third welding station 6 and the fourth welding station 7, and between the fourth welding station 7 and the fifth welding station 8. The connecting stabilizing arms 10 have a triangular shape. Several sets of stabilizing holes 11 are distributed laterally at equal intervals on the surface of the connecting stabilizing arms 10. The stabilizing holes 11 have a parallelogram shape. Stabilizing blocks 12 are provided inside the stabilizing holes 11. The stabilizing blocks 12 have a triangular shape.

[0029] Analysis of the above content: Based on five welding stations (first welding station 4, second welding station 5, third welding station 6, fourth welding station 7, and fifth welding station 8) as the basic support unit, casters 9 are fixed on them with screws to form a movable base; the connecting stabilizing arm 10 utilizes the mechanical properties of triangular stability to rigidly connect adjacent welding stations, reducing structural deformation; the triangular stabilizing block 12 in the stabilizing hole 11 (parallelogram) further disperses stress, while the fixing hole 13 realizes the switching between movement and fixation. When moving: the fixing parts in the fixing hole 13 are loosened, and the device body 1 is pushed to move by the 360° rotation of the casters 9.

[0030] Example 2:

[0031] Please see Figure 1-3 Based on Embodiment 1, this utility model provides a technical solution: the bottom of the first welding station 4, the second welding station 5, the third welding station 6, the fourth welding station 7, and the fifth welding station 8 are all provided with a set of welding feet 14 distributed symmetrically. The welding feet 14 are triangular in shape, and the surface of the welding feet 14 is provided with a plurality of reinforcing holes 15. The reinforcing holes 15 are rectangular in shape, and the reinforcing holes 15 are provided with reinforcing blocks 16 inside. The reinforcing blocks 16 are rectangular in shape.

[0032] Analysis of the above: The triangular welding foot 14 increases the contact area between the first welding platform 4 to the fifth welding platform 8 and the bottom, reducing local stress by dispersing pressure; the rectangular reinforcing block 16 in the rectangular reinforcing hole 15 fills the gap, improving the shear strength of the welding foot 14 and preventing long-term load deformation. In the initial stage of installation: check the welding firmness between the welding foot 14 and the welding platform to ensure that the reinforcing block 16 is fully embedded in the reinforcing hole 15. In long-term use: if the protective cover shakes, check whether the welding foot 14 is deformed, replace the reinforcing block 16 or repair it by welding. In heavy-load scenarios: add a high-strength gasket in the reinforcing hole 15 to enhance the load-bearing capacity of the first welding platform 4 to the fifth welding platform 8. The combination of the triangular welding foot 14 and the rectangular reinforcing block 16 achieves high load-bearing capacity under lightweight design.

[0033] Example 3:

[0034] Please see Figure 1-3 This utility model provides a technical solution based on Embodiment 1: The protective cover device 2 includes a top plate 17, a front plate 18, a rear plate 19, a first side plate 20, and a second side plate 21. The top plate 17, the front plate 18, the rear plate 19, the first side plate 20, and the second side plate 21 are smoothly transitioned and integrally formed. The front plate 18 and the rear plate 19 are located at the bottom front end and the bottom rear end of the top plate 17, respectively. The first side plate 20 and the second side plate 21 are located at the bottom left end and the bottom right end of the top plate 17, respectively. A motor mounting notch 28 is provided on the right side of the front plate 18.

[0035] Analysis of the above content: The top plate 17, front plate 18, rear plate 19, first side plate 20, and second side plate 21 are integrally formed to achieve seamless sealing, reducing noise leakage and dust ingress; the motor mounting notch 28 of the front plate 18 is adapted to the position of the test bench motor to avoid the motor protruding and damaging the seal.

[0036] Example 4:

[0037] Please see Figure 1-3Based on Embodiment 1, this utility model provides a technical solution: the top plate 17, the front plate 18, the rear plate 19, the first side plate 20 and the second side plate 21 are all provided with mounting openings 22, and double-layer observation and soundproof glass 23 is installed in the mounting openings 22.

[0038] Analysis of the above content: The double-layer observation soundproof glass 23 inside the mounting port 22 blocks the transmission of sound waves through a double air layer, while ensuring that the test personnel can observe the internal equipment in real time; the double-layer design improves the impact resistance and sound insulation effect compared with the single layer. During observation: the speed and vibration of the equipment are monitored through the double-layer observation soundproof glass 23 without opening the protective cover device 2. During cleaning: the glass surface is wiped with a special cleaning agent to avoid dust affecting the observation. In case of damage: the double-layer observation soundproof glass 23 inside the mounting port 22 is replaced separately without affecting other structures.

[0039] Example 5:

[0040] Please see Figure 1-3 Based on Embodiment 1, this utility model provides a technical solution: the top plate 17, front plate 18, rear plate 19, first side plate 20 and second side plate 21 each include an outer layer plate 24 and an inner layer plate 25. The outer layer plate 24 is located outside the inner layer plate 25. There is a slot 27 between the outer layer plate 24 and the inner layer plate 25. The slot 27 is filled with sound insulation cotton 26.

[0041] Analysis of the above content: The outer layer plate 24 and the inner layer plate 25 form a double shell. The sound insulation cotton 26 filled in the middle slot 27 absorbs sound waves through multiple layers of insulation, reducing noise transmission. The slot 27 also reduces the rigid connection between the inner and outer layers, reduces resonance, and has a heat insulation effect. The combination of double layer plate and sound insulation cotton 26 has a better sound insulation effect than a single layer structure, making it suitable for high-speed equipment.

[0042] Specifically, a comparison of relevant test data and practical application data for this solution.

[0043] Technical indicators Existing technology (mean) This utility model solution (mean value) Increase Number of people required for the move (in persons) 2.5 1 60.0％ Emergency response time (seconds) 7.2 5.8 19.4％ Space occupancy rate (%) 78.5 71.2 9.3％ Maintenance time per session (minutes) 28.6 24.3 15.0％ Sound insulation effect (decibels) 22.3 20.5 8.1％

[0044] Data Description

[0045] Number of people required for movement: Through simulated test scenarios, existing technologies, due to the lack of a moving structure, require an average of 2-3 people to work together to move the object; this solution, with the help of casters, can be pushed by a single person. The difference is calculated by taking the average value.

[0046] Emergency response time: The time taken from the time the equipment alarms abnormally to the time it takes to open the protective cover for inspection. Existing technology requires the removal of the fixing parts first, while this solution can be directly pushed. The average time is taken from multiple tests.

[0047] Space occupancy rate: In a standard test workshop (10m×8m), the ratio of the idle area to the total area of ​​the workshop was measured for both schemes, and the average value was taken after three repetitions.

[0048] Single maintenance time: The time required to remove and install the protective cover using existing technology and the time required to move the protective cover using this solution when replacing test bench cables, including tool preparation and finishing steps.

[0049] Sound insulation effect: Under the same noise source (running noise of the speed test bench is 85 decibels), the sound level meter was used to measure at a distance of 1 meter outside the protective cover. Each set of data was recorded 5 times and the average value was taken.

[0050] Data Validity Statement

[0051] Consistency of test conditions: All data were collected under the same test bench (power 5.5kW), the same ambient temperature (25±2℃), and the same operators (3 skilled technicians rotating), to reduce interference from variables.

[0052] Sample size rationality: Each indicator is tested ≥5 times, and the mean is taken after removing extreme values ​​(data with a deviation exceeding 15% of the mean), which conforms to the statistical law of small samples.

[0053] Measurement tool accuracy: Time measurement uses a stopwatch (accuracy 0.1 seconds), noise measurement uses a professional sound level meter (accuracy ±0.5 dB), and spatial measurement uses a laser rangefinder (accuracy ±1 mm).

[0054] The present invention comprises: 1. a device body; 2. a protective cover device; 3. a cover movement adjustment device; 4. a first welding table; 5. a second welding table; 6. a third welding table; 7. a fourth welding table; 8. a fifth welding table; 9. a caster wheel; 10. a connecting stabilizing arm; 11. a stabilizing hole; 12. a stabilizing block; 13. a fixing hole; 14. a welding foot; 15. a reinforcing hole; 16. a reinforcing block; 17. a top plate; 18. a front plate; 19. a rear plate; 20. a first side plate; 21. a second side plate; 22. a mounting port; 23. double-layer observation soundproof glass; 24. an outer layer plate; 25. an inner layer plate; 26. sound insulation cotton; 27. a slot; and 28. a motor mounting notch. All components are general standard parts or parts known to those skilled in the art. Their structure and principles can be learned by those skilled in the art through technical manuals or conventional experimental methods. The present invention solves the problem of… The problem is that the existing protective covers of speed testing benches are large and cannot be easily moved, resulting in the following drawbacks: slow emergency response: when equipment malfunctions suddenly (such as abnormal noises or smoke), the protective cover cannot be moved quickly to check the internal situation, which may delay fault handling or even increase the risk of safety accidents; laborious position adjustment: the protective cover needs to be moved manually. Due to its large size and weight, multiple people are needed to move it, increasing labor costs, and improper handling may cause damage to the equipment; low space utilization: when the speed testing bench needs to temporarily free up space (such as for cleaning or moving other equipment), it cannot be flexibly adjusted by moving the protective cover, resulting in limited site planning. This utility model, through the combination of the above components, can achieve 360° free movement by pushing the protective cover, adapting to the protection needs of different test bench positions and workpiece specifications, reducing labor costs and operation time.

[0055] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. It will be apparent to those skilled in the art that this utility model is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or basic characteristics of this utility model. Therefore, the embodiments should be considered exemplary and non-limiting in all respects. The scope of this utility model is defined by the appended claims rather than the foregoing description, and thus all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this utility model. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0056] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A movable protective cover for a speed testing bench, characterized in that: The device includes a main body (1), which includes a protective cover device (2) and a cover movement adjustment device (3), wherein the cover movement adjustment device (3) is welded to the bottom of the inside of the protective cover device (2); The cover movement adjustment device (3) includes a first welding platform (4), a second welding platform (5), a third welding platform (6), a fourth welding platform (7), a fifth welding platform (8), and casters (9). The first welding platform (4) is located to the left of the second welding platform (5), the third welding platform (6) is located in front of the first welding platform (4), the fourth welding platform (7) is located to the right of the third welding platform (6), and the fifth welding platform (8) is located in front of the fourth welding platform (7). There are five casters (9), and the five casters (9) are respectively fixed to the first welding platform (4), the second welding platform (5), the third welding platform (6), the fourth welding platform (7), and the fifth welding platform (8) by screws. The first welding platform (4) and the second welding platform (5) Two sets of fixing holes (13) are provided on the third welding station (6), the fourth welding station (7), the fifth welding station (8) and the caster wheel (9). Connecting stabilizing arms (10) are welded between the first welding station (4) and the second welding station (5), between the first welding station (4) and the third welding station (6), between the third welding station (6) and the fourth welding station (7), and between the fourth welding station (7) and the fifth welding station (8). The connecting stabilizing arms (10) are triangular in shape. Several sets of stabilizing holes (11) are provided on the surface of the connecting stabilizing arms (10) in a horizontally equidistant manner. The stabilizing holes (11) are parallelogram-shaped. Stabilizing blocks (12) are provided inside the stabilizing holes (11). The stabilizing blocks (12) are triangular in shape.

2. The movable protective cover for a speed testing bench according to claim 1, characterized in that: The bottom of the first welding station (4), the second welding station (5), the third welding station (6), the fourth welding station (7), and the fifth welding station (8) are provided with a set of welding feet (14) distributed symmetrically. The welding feet (14) are triangular in shape. Several sets of reinforcing holes (15) are opened on the surface of the welding feet (14). The reinforcing holes (15) are rectangular in shape. Reinforcing blocks (16) are provided inside the reinforcing holes (15). The reinforcing blocks (16) are rectangular in shape.

3. The movable protective cover for a speed testing bench according to claim 1, characterized in that: The protective cover device (2) includes a top plate (17), a front plate (18), a rear plate (19), a first side plate (20), and a second side plate (21). The top plate (17), the front plate (18), the rear plate (19), the first side plate (20), and the second side plate (21) are smoothly transitioned and integrally formed. The front plate (18) and the rear plate (19) are located at the front end and rear end of the bottom of the top plate (17), respectively. The first side plate (20) and the second side plate (21) are located at the left end and right end of the bottom of the top plate (17), respectively. A motor mounting notch (28) is provided on the right side of the front plate (18).

4. The movable protective cover for a speed testing bench according to claim 3, characterized in that: The top plate (17), front plate (18), rear plate (19), first side plate (20) and second side plate (21) are all provided with mounting openings (22), and double-layer observation soundproof glass (23) is installed in the mounting openings (22).

5. A movable protective cover for a speed testing bench according to claim 3, characterized in that: The top plate (17), front plate (18), rear plate (19), first side plate (20) and second side plate (21) each include an outer plate (24) and an inner plate (25). The outer plate (24) is located outside the inner plate (25). There is a slot (27) between the outer plate (24) and the inner plate (25). The slot (27) is filled with sound insulation cotton (26).

Images