A noise automatic detection device and method for a seat belt

Abstract

The application discloses a kind of automatic detection device and detection method of noise of safety belt.It includes detection table, the positioning seat for being positioned to retractor being provided on detection table and the vibration sensor for detecting vibration information, positioning seat is provided with the limiting pressure plate for limiting the mounting bracket of retractor, retractor is wound with webbing;Vibration sensor is fixedly installed at the bottom of detection table and is located below positioning seat, so as to obtain vibration information directly by vibration sensor when pulling webbing.The advantage is: noise detection can be carried out at the same time when product detection is carried out, not only improves production efficiency, but also simulates real application environment in the process, so that the accuracy of noise detection is more easily characterized, and the uncertainty of noise source is eliminated.

Description

Technical Field

[0001] This invention relates to a noise detection technology for seat belts, specifically an automatic noise detection device and method for seat belts. Background Technology

[0002] As a core component of a car's passive safety system, the noise issues (such as clicking, friction, or impact sounds) of the seat belt's internal retractor, buckle mechanism, and webbing during movement directly affect the user's sensory experience and the overall vehicle's quietness. Therefore, rigorous noise testing of seat belts during the manufacturing process is a key step in ensuring the quality of products leaving the factory.

[0003] Currently, noise detection in seat belt production typically relies on manual testing or simple acoustic testing devices. On one hand, manual testing is heavily influenced by operator subjectivity and ambient noise, resulting in poor consistency and low efficiency. On the other hand, acoustic testing devices often use air-conductive microphones for non-contact sound pickup; however, in the complex industrial environment of a production workshop, air-conductive testing is easily interfered with by external ambient noise (such as equipment operation noise and personnel conversations), leading to a low signal-to-noise ratio and difficulty in accurately capturing minute abnormal vibration signals inside the seat belt. Later, some researchers used simple vibration sensors for detection, but existing conventional vibration detection methods are highly susceptible to environmental influences, with vibration signals attenuating or distorting during transmission, failing to accurately reflect the noise characteristics of the product under specific operating conditions. Furthermore, noise detection is usually a subsequent process, typically performed after product inspection, resulting in low efficiency. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an automatic noise detection device and method for seat belts that can perform high-precision vibration signal acquisition, effectively eliminate environmental interference, and have high detection efficiency.

[0005] To solve the above-mentioned technical problems, the present invention provides an automatic noise detection device for seat belts, including a detection platform, a positioning seat on the detection platform for positioning a retractor, and a vibration sensor for detecting vibration information. The positioning seat is provided with a limiting pressure plate for limiting the mounting bracket of the retractor, and webbing is wound on the retractor. The vibration sensor is fixedly installed at the bottom of the detection platform and below the positioning seat, so that vibration information can be directly obtained through the vibration sensor when the webbing is pulled.

[0006] A cylinder is installed at the bottom of the testing platform. The telescopic end of the cylinder extends above the testing platform and presses against the horizontal side of the mounting bracket of the retractor.

[0007] The positioning base includes a base body and a pair of positioning blocks, namely a first positioning block and a second positioning block, which are disposed on the base body for positioning the winding box of the retractor and the mounting bracket of the retractor.

[0008] The first positioning block includes a first platform and a side stop block provided on the first platform. The second positioning block includes a second platform and a rear stop block provided on the second platform. One side wall of the retractor mounting bracket presses against the inner wall of the first platform. One side wall of the retractor's winding box presses against the inner wall of the side stop block. The other side wall of the retractor mounting bracket presses against the inner wall of the rear stop block. One side wall of the retractor's winding box is located above the second platform of the second positioning block.

[0009] The limiting pressure plate includes a U-shaped plate with a U-shaped structure and a notch on the bottom surface of the plate. The limiting pressure plate is fixedly installed on the detection table by fasteners and the notch can form an insertion groove for inserting into the rear end of the mounting bracket of the retractor.

[0010] The mounting bracket of the retractor has a through hole at its rear end, and the telescopic end of the cylinder is connected to a clamping nut through the U-shaped groove of the U-shaped plate.

[0011] The bottom of the testing platform is equipped with a protective cover for protecting the cylinder, and a connecting plate for connecting and fixing to the testing platform is provided on each of the two side walls of the protective cover.

[0012] The retractor has a pair of workpiece detection components on its left and right sides. The workpiece detection device includes a detection bracket and an optical fiber sensor fixedly installed inside the detection bracket. The side wall of the detection table is provided with a mounting groove for installing the detection bracket. The connecting plate has an ear plate covering the detection bracket.

[0013] A detection method based on the above-mentioned automatic noise detection device includes the following steps: A. Select at least three defective retractors as defect detection samples. After locating them using the automatic noise detection device, obtain the peak acceleration, effective acceleration, and peak velocity of the defect detection samples through vibration sensors, calculate their average values, and record each defect index. B. Select at least three qualified receivers as qualified test samples. After positioning them by the automatic noise detection device, obtain the peak acceleration, effective acceleration, and peak velocity of the qualified test samples by the vibration sensor in sequence, calculate their average values, and record each qualified index. C. Set thresholds based on defect and pass / fail indicators, position and install the product to be tested on the automatic noise detection device, start the test, and during the test, the noise detection period is from the start of the pull to the end of the pull and the three indicators are compared with the set thresholds. After accumulating a certain amount of product data, the detection thresholds can be adjusted according to the actual detection situation.

[0014] The threshold setting method is as follows: if the average value of defective sample data is A and the average value of qualified sample data is B, then the normal detection parameter K is set as follows: 1.2B < K < 0.8A.

[0015] The advantages of this invention are: (1) The positioning seat for positioning the retractor and the vibration sensor for detecting vibration information are set up so that noise detection can be performed at the same time as product inspection. This not only improves production efficiency, but also simulates the real application environment in the process, making it easier to characterize the accuracy of noise detection and eliminating the uncertainty of noise source.

[0016] (2) A cylinder is installed at the bottom of the test table, which is used to press the cylinder against the horizontal side of the mounting bracket of the retractor to ensure reliable pressing. This allows the vibration sensor to directly obtain the most accurate vibration information, avoiding the detection noise problem caused by the retractor not being securely fixed during the test.

[0017] (3) By setting a No. 1 positioning block with a No. 1 platform and a side stop block and a No. 2 positioning block with a No. 2 platform and a rear stop block on the positioning seat, the mounting bracket and winding box of the winding device are precisely positioned by the No. 1 platform, the side stop block, the No. 2 platform and the rear stop block, which further eliminates the problem of detection noise caused by the winding device not being securely fixed during the detection process.

[0018] (4) By setting a U-shaped plate with a U-shaped structure and a limiting pressure plate with a notch on the bottom surface of the plate, the limiting pressure plate can be fixed on the test table by fasteners. This can make the notch form an insertion slot for inserting the rear end of the mounting bracket of the retractor, further avoiding abnormal noise caused by vibration during the test, thereby greatly improving the accuracy of noise detection.

[0019] (5) By connecting the extension end of the cylinder to the clamping nut through the U-shaped groove of the U-shaped plate, the installation space is saved and the reliability of clamping is improved.

[0020] (6) This method cleverly sets thresholds based on defect indicators and qualified indicators, and then positions the product to be tested on the automatic noise detection device for noise detection. The detection method is reasonable, effectively detects real noise and does not affect the cycle time of the entire process. It can objectively reflect the product’s performance in terms of abnormal noise and significantly improve the product’s quality level in terms of comfort. Attached Figure Description

[0021] Figure 1 This is a three-dimensional structural diagram of the automatic noise detection device for seat belts of the present invention in use. Figure 2 This is a top view of the structure of the automatic noise detection device for seat belts of the present invention in use. Figure 3 This is an exploded view of the automatic noise detection device for seat belts of the present invention in its operational state. Figure 4 This is a three-dimensional structural diagram of the limiting pressure plate in this invention; Figure 5 This is a three-dimensional structural diagram of the positioning seat in this invention; Figure 6 This is a test data analysis chart of the first test of seat belt A in Embodiment 2 of the present invention; Figure 7 This is a test data analysis chart of the second test of seat belt A in Embodiment 2 of the present invention; Figure 8 This is a test data analysis chart of the first test of seat belt B in Embodiment 2 of the present invention; Figure 9 This is a test data analysis chart of the second test of seat belt B in Embodiment 2 of the present invention. Detailed Implementation

[0022] The automatic noise detection device for seat belts and the detection method based on the automatic noise detection device of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Example 1

[0023] As shown in the figure, this embodiment provides an automatic noise detection device for seat belts, including a detection platform 1, a positioning seat 3 on the detection platform for positioning a retractor 2, and a vibration sensor 4 for detecting vibration information. In this embodiment, the vibration sensor used is model VSA001. The retractor 2 mainly includes a U-shaped mounting bracket 11, a retractor box 9 supported by the U-shaped mounting bracket 11, and webbing 8 wound on the retractor box 9. Figure 3As can be seen, the mounting bracket 11 is mainly a U-shaped frame with a U-shaped cross-section, consisting of a base plate as the horizontal side and side plates formed by bending the base plate on both sides. The positioning seat 3 is equipped with a limiting pressure plate 5 for limiting the mounting bracket 11 of the retractor. The bottom of the test table 1 is equipped with a cylinder 10. The telescopic end of the cylinder 10 extends above the test table, passes through the positioning seat 3, and presses against the horizontal side formed by the base plate of the mounting bracket 11 of the retractor 2. That is to say, the cylinder 10 completely tightens and fixes the mounting bracket 11, the positioning seat 3, and the test table 1 into one unit, thereby achieving the purpose of completely fixing the retractor on the test table, so that the most accurate vibration information can be obtained directly. The bottom of the test table 1 is equipped with a protective cover 2 for protecting the cylinder. 3. A connecting plate 24 is provided on each of the two side walls of the protective cover for connecting and fixing to the testing platform. The protective cover can be fixedly installed at the bottom of the testing platform through the connecting plate 24. The positioning seat 3 includes a seat body 12, a first positioning block 13 and a second positioning block 14 provided on the seat body. The first positioning block 13 and the second positioning block 14 can be used to position the winding box of the retractor and the mounting bracket of the retractor. The vibration sensor 4 is fixedly installed at the bottom of the testing platform 1 and below the positioning seat 3, thereby realizing the fixed installation of the vibration sensor 4 and the testing platform. As shown in the figure, the vibration sensor 4 is fixedly installed on the side of the cylinder, so that the most accurate vibration information can be directly obtained through the vibration sensor when the webbing is pulled.

[0024] Furthermore, the first positioning block 13 includes a first platform 15 and a side stop 16 provided on the first platform, and the second positioning block 14 includes a second platform 17 and a rear stop 18 provided on the second platform. One side wall of the retractor mounting bracket 11 presses against the inner wall of the first platform 15, one side wall of the retractor's take-up box presses against the inner wall of the side stop 16, and the other side wall of the retractor mounting bracket presses against the inner wall of the rear stop 18. One side wall of the retractor's take-up box is located above the second platform of the second positioning block 14. By designing the structure of the first positioning block 13 and the second positioning block 14, the retractor can be positioned in different directions, meeting the requirements of precise positioning and providing a reliable foundation for testing.

[0025] Furthermore, the limiting pressure plate 5 includes a U-shaped plate 19 with a U-shaped structure and a notch 20 on the bottom surface of the plate. The U-shaped plate has a U-shaped groove. The limiting pressure plate 5 is fixedly installed on the positioning seat on the detection table 1 by fasteners and the notch can form an insertion groove for inserting the rear end of the mounting bracket of the retractor. At the same time, a through hole located in the U-shaped groove is provided on the seat 12 of the positioning seat. The rear end of the mounting bracket of the retractor 2 has a through hole 21 that corresponds to the position of the through hole. The telescopic end of the cylinder 10 passes through the through hole provided on the seat 12 and the U-shaped groove of the U-shaped plate in sequence and is connected to a clamping nut 22.

[0026] Furthermore, a pair of workpiece detection components are provided on the left and right sides of the retractor. The workpiece detection device includes a detection bracket 6 and an optical fiber sensor 7 fixedly installed inside the detection bracket. The side wall of the detection table 1 is provided with a mounting groove 25 for installing the detection bracket 6. The detection bracket 6 is fixedly installed in the mounting groove 25 of the detection table 1. The connecting plate 24 has an ear plate 26 covering the outside of the detection bracket 6, so that after the detection bracket is fixedly installed, the ear plate 26 on the connecting plate 24 covers the outside of the detection bracket 6. Example 2

[0027] This embodiment provides a detection method based on the automatic noise detection device described in Embodiment 1, including the following steps: A. Select three defective retractors 2 as defect detection samples. After positioning them by the automatic noise detection device, the peak acceleration, effective acceleration, and peak velocity of the defect detection samples are obtained by the vibration sensor 7 in sequence. The average value is calculated and each defect index is recorded as A1 / B1 / C1. B. Select three qualified receivers 2 as qualified test samples. After positioning them by the automatic noise detection device, the peak acceleration, effective acceleration, and peak velocity of the qualified test samples are obtained by the vibration sensor 7 in sequence. The average value is calculated and each qualified index is recorded. C. Set thresholds based on defect and pass / fail indicators, position the product to be tested on the automatic noise detection device, and start the test. During the test, according to the national standard test requirements: when testing the feel of the seat belt, pull out the entire webbing and wrap it back 300mm. The noise detection period is from the start of pulling to the end of pulling. Detect three indicators and compare them with the set thresholds. After accumulating a certain amount of product data, the detection thresholds can be adjusted according to the actual test results.

[0028] The threshold setting method is as follows: if the average value of defective sample data is A and the average value of qualified sample data is B, then the normal detection parameter K setting method is: 1.2B < K < 0.8A.

[0029] Additionally, it should be noted that regardless of whether it is during the defect detection sample acquisition process, the qualified test sample acquisition process, or the formal testing process, when positioning the retractor, the retractor product is placed on the positioning seat 3 of the testing table 1 and positioned by the first positioning block 13 and the second positioning block 14 set on the positioning seat 3. The first positioning block 13 and the second positioning block 14 are used to position the retractor product's winding box and the side wall of the retractor's mounting bracket. At the same time, the positioning plate 5 is used to position the rear side of the mounting bracket of the product under test. After positioning and installation, the vibration sensor 7 is used to acquire the corresponding required data.

[0030] The following uses seat belt A and seat belt B as examples to verify their effectiveness: During the first test of seat belt A: during withdrawal, its peak acceleration (a-peak) was approximately 523.88 mg; effective acceleration (a-rms) was approximately 155.64 mg; and effective velocity (v-rms) was approximately 1.81 mm / s.

[0031] During the second test of seat belt A: during withdrawal, its peak acceleration (a-peak) was approximately 663.42 mg; effective acceleration (a-rms) was approximately 162.41 mg; and effective velocity (v-rms) was approximately 2.08 mm / s.

[0032] During the first test of seat belt B: during withdrawal, its peak acceleration (a-peak) was approximately 176.26 mg; effective acceleration (a-rms) was approximately 42.82 mg; and effective velocity (v-rms) was approximately 0.41 mm / s.

[0033] During the second test of seat belt B: during withdrawal, its peak acceleration (a-peak) was approximately 181.15 mg; effective acceleration (a-rms) was approximately 41.70 mg; and effective velocity (v-rms) was approximately 0.35 mm / s.

[0034] The test results are shown in the table below:

[0035] By analyzing the test data, some simple conclusions can be drawn: During the seatbelt test, significant differences were observed in vibration data (test range: the section where the webbing is fully extended); the peak acceleration (a-peak), effective acceleration (a-rms), and effective velocity (v-rms) all showed significant differences. Therefore, this invention, through its automatic noise detection device and method, achieves the most reliable fixation method based on the device's installation structure, avoiding the intervention of abnormal factors. It obtains the most accurate data through vibration sensors and, based on the normal setting method of the detection parameter K (1.2B < K < 0.8A), controls it within a reasonable range, determining an appropriate threshold to obtain optimal results. Corresponding vibration data can be obtained during the test, demonstrating outstanding performance.

[0036] Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. An automatic noise detection device for seat belts, characterized in that: The device includes a testing platform (1), a positioning seat (3) on the testing platform for positioning the retractor (2), and a vibration sensor (4) for detecting vibration information. The positioning seat (3) is provided with a limiting pressure plate (5) for limiting the mounting bracket (11) of the retractor. The retractor (2) is wound with webbing (8). The vibration sensor (4) is fixedly installed at the bottom of the testing platform (1) and located below the positioning seat (3), so that vibration information can be directly obtained through the vibration sensor when the webbing is pulled.

2. The automatic noise detection device according to claim 1, characterized in that: A cylinder (10) is provided at the bottom of the testing platform (1). The telescopic end of the cylinder (10) extends above the testing platform and presses against the horizontal side of the mounting bracket (11) of the retractor (2).

3. The automatic noise detection device according to claim 1 or 2, characterized in that: The positioning base (3) includes a base body (12) and a pair of positioning blocks (13) and (14) provided on the base body for positioning the winding box of the winding machine and the mounting bracket of the winding machine.

4. The automatic noise detection device according to claim 3, characterized in that: The first positioning block (13) includes a first platform (15) and a side stop (16) provided on the first platform. The second positioning block (14) includes a second platform (17) and a rear stop (18) provided on the second platform. One side wall of the mounting bracket (11) of the retractor is pressed against the inner wall of the first platform (15). One side wall of the retractor's winding box is pressed against the inner wall of the side stop (16). The other side wall of the mounting bracket of the retractor is pressed against the inner wall of the rear stop (18). One side wall of the retractor's winding box is located above the second platform of the second positioning block (14).

5. The automatic noise detection device according to claim 1, 2 or 4, characterized in that: The limiting pressure plate (5) includes a U-shaped plate (19) with a U-shaped structure and a notch (20) provided on the bottom surface of the plate. The limiting pressure plate (5) is fixedly installed on the detection table (1) by fasteners and the notch can form an insertion groove for inserting into the rear end of the mounting bracket of the retractor.

6. The automatic noise detection device according to claim 5, characterized in that: The rear end of the mounting bracket of the retractor (2) has a through hole (21), and the telescopic end of the cylinder (10) is connected to a clamping nut (22) through the U-shaped groove of the U-shaped plate.

7. The automatic noise detection device according to claim 2, characterized in that: The bottom of the testing platform (1) is provided with a protective cover (23) for protecting the cylinder, and a connecting plate (24) for connecting and fixing to the testing platform is provided on each of the two side walls of the protective cover.

8. The automatic noise detection device according to claim 7, characterized in that: The retractor is provided with a pair of workpiece detection components on the left and right sides. The workpiece detection device includes a detection bracket (6) and an optical fiber sensor (7) fixedly installed inside the detection bracket. The side wall of the detection table (1) is provided with a mounting groove (25) for installing the detection bracket (6). The connecting plate (24) has an ear plate (26) covering the detection bracket (6).

9. A detection method based on the automatic noise detection device according to any one of claims 1-8, characterized in that, Includes the following steps: A. Select at least three defective retractors (2) as defect detection samples. After positioning them by the automatic noise detection device, obtain the peak acceleration, effective acceleration, and peak velocity of the defect detection samples by the vibration sensor (4) in sequence, calculate their average values, and record each defect index. B. Select at least three qualified receivers (2) as qualified test samples, locate them by the noise automatic detection device, and obtain the peak acceleration, effective acceleration, and peak velocity of the qualified test samples by the vibration sensor (7) in sequence, calculate their average values, and record each qualified index. C. Set thresholds based on defect and pass / fail indicators, position and install the product to be tested on the automatic noise detection device, start the test, and during the test, the noise detection period is from the start of the pull to the end of the pull and the three indicators are compared with the set thresholds. After accumulating a certain amount of product data, the detection thresholds can be adjusted according to the actual detection situation.

10. The detection method based on the automatic noise detection device according to claim 9, characterized in that: The threshold setting method is as follows: if the average value of defective sample data is A and the average value of qualified sample data is B, then the normal detection parameter K is set as follows: 1.2B < K < 0.8A.

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