A method for improving the abnormal sound of a steering column

Abstract

The application discloses a method for improving abnormal sound of a steering column, and belongs to the technical field of steering systems. The method for improving abnormal sound of the steering column determines a first sensitive area prone to wear in an early stage and a second sensitive area prone to wear in a later stage of the steering column during long-time use through a durability test, processes the first sensitive area by using a laser to form a first micro-groove morphology, and processes the second sensitive area by using a laser to form a second micro-groove morphology. In other words, different laser micro-morphologies are designed for different sensitive areas, which can not only improve the tribological properties of different sensitive areas, but also improve the storage capacity of different sensitive areas for lubricants and the storage capacity of different sensitive areas for abrasive particles, so that the loose space abnormal sound of the worm and the worm gear caused by long-time wear is obviously improved. Compared with the prior art, other components do not need to be added, and the structural complexity of the steering system is not increased.

Description

Technical Field

[0001] This invention relates to the field of steering system technology, and in particular to a method for improving abnormal noise from the steering column. Background Technology

[0002] The reduction gear of the existing column-type electric power steering system is mainly composed of a worm gear mechanism. After long-term use, the worm gear and worm will wear down, resulting in an increase in the gap between the worm gear and worm. This causes a loose feel and abnormal noise when the vehicle is turned, affecting the driver's driving comfort and the reliability of the whole vehicle.

[0003] To eliminate the clearance that appears between the worm gear and worm after prolonged wear, previous studies have mostly adopted the method of adding a clearance compensation mechanism inside the housing to compensate for and adjust the clearance between the worm gear and worm. However, adding a clearance compensation mechanism inside the housing is not only structurally complex and costly, but if the clearance compensation mechanism fails, it will not only fail to compensate, but the parts between the mechanisms will also collide and rub against each other, and may even introduce new abnormal noises. Summary of the Invention

[0004] The purpose of this invention is to provide a method for improving steering column noise without increasing the complexity of the steering system structure.

[0005] To achieve the above objectives, the following technical solution is provided:

[0006] A method for improving abnormal noise from the steering column includes the following steps:

[0007] The steering column is subjected to n durability tests; n is a natural number greater than zero.

[0008] Based on the experimental results, the first sensitive area that needs improvement was identified;

[0009] The first sensitive area is processed using a laser to form a first micro-groove morphology;

[0010] The steering column that has undergone laser treatment once is subjected to m durability tests; m is a natural number greater than zero, and m > n;

[0011] Based on the test results, identify the second sensitive area that needs improvement;

[0012] The second sensitive area is processed using a laser to form a second microgroove morphology;

[0013] Add lubricant to the steering column that has undergone two laser treatments.

[0014] As an alternative method for improving steering column noise, the first microgroove morphology includes multiple microgrooves with a dot-like structure; and / or,

[0015] The second microgroove morphology includes multiple microgrooves with a linear structure.

[0016] As an alternative method to improve steering column noise,

[0017] Prior to conducting n durability tests on the steering column, the following is also included:

[0018] Measure the clearance of the reduction gear in the steering column.

[0019] As an alternative method to improve steering column noise,

[0020] After the n durability tests on the steering column, the following is also included:

[0021] Measure the clearance of the reduction gear in the steering column.

[0022] As an alternative method to improve steering column noise,

[0023] After the steering column has undergone m durability tests, the following is also included:

[0024] Measure the clearance of the reduction gear in the steering column.

[0025] As an alternative method to improve steering column noise,

[0026] Prior to conducting n durability tests on the steering column, the following is also included:

[0027] Measure the loudness of the deceleration mechanism in the steering column.

[0028] As an alternative method to improve steering column noise,

[0029] After the n durability tests on the steering column, the following is also included:

[0030] Measure the loudness of the deceleration mechanism in the steering column.

[0031] As an alternative method to improve steering column noise,

[0032] After the steering column has undergone m durability tests, the following is also included:

[0033] Measure the loudness of the deceleration mechanism in the steering column.

[0034] As an alternative method to improve steering column noise,

[0035] The first sensitive area that needs improvement based on experimental results also includes:

[0036] The steering column, having undergone n durability tests, is disassembled, and each component of the disassembled steering column is examined under a microscope to identify the first sensitive area requiring improvement; and / or,

[0037] The second sensitive area that needs improvement based on the test results also includes:

[0038] The steering column, which has undergone m durability tests, is disassembled, and each component of the disassembled steering column is observed under a microscope and weighed to determine the second sensitive area that needs improvement.

[0039] As an alternative method to improve steering column noise,

[0040] In the process of using a laser to process the first sensitive area and form the first microgroove morphology, the laser is a single-pulse laser; and / or,

[0041] In the process of using a laser to process the second sensitive area and form the second microgroove morphology, the laser used is a continuous pulse laser.

[0042] As an alternative method for improving steering column noise, in the process of using a laser to process the first sensitive area and form a first microgroove morphology, the power of the laser is P1 and the pulse width is W1.

[0043] In the process of using a laser to process the second sensitive area and form the second microgroove morphology, the power of the laser is P2 and the pulse width is W2.

[0044] Then P1 = P2, W1 = W2.

[0045] As an alternative method to improve steering column noise, in the n durability tests conducted on the steering column, the test conditions for the durability tests are: fixing the input end of the steering column, applying a sinusoidal load to the output end of the steering column, with a loading torque of ±30 N·m; and / or,

[0046] In the aforementioned durability test of the steering column after one laser treatment, the test conditions are as follows: the input end of the steering column is fixed, and the output end of the steering column is loaded with a sinusoidal load with a loading torque of ±30 N·m.

[0047] As an alternative method for improving steering column noise, the first sensitive area is the region from the pitch circle to the addendum circle of the worm gear teeth; and / or,

[0048] The second sensitive area is the region from the pitch circle to the root circle of the worm gear teeth.

[0049] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0050] The method for improving steering column noise of the present invention, through durability testing, identifies a first sensitive area of ​​the steering column that is prone to wear in the early stages and a second sensitive area that is prone to wear in the later stages during long-term use. The first sensitive area is treated with a laser to form a first micro-groove morphology, and the second sensitive area is treated with a laser to form a second micro-groove morphology. In other words, different laser micro-groove morphologies are designed for different sensitive areas, which not only improves the tribological properties of different sensitive areas but also enhances their lubricant retention capacity and their ability to retain abrasive particles. This significantly improves the loose noise caused by long-term wear of the worm gear. Furthermore, compared to existing technologies, this method does not require additional components and does not increase the structural complexity of the steering system. Attached Figure Description

[0051] Figure 1 This is a simplified flowchart of a method for improving abnormal noise from the steering column in an embodiment of the present invention;

[0052] Figure 2 This is a detailed flowchart of the method for improving abnormal noise from the steering column in an embodiment of the present invention;

[0053] Figure 3 The image shows line graphs of the clearance of the deceleration mechanism measured by the 20 steering columns in this embodiment of the invention before the durability test, after 30,000 durability tests, and after 70,000 durability tests.

[0054] Figure 4 The following is a line graph showing the loudness of the deceleration mechanism measured by 20 steering columns in this embodiment of the invention before the durability test, after 30,000 durability tests, and after 70,000 durability tests.

[0055] Figure 5 This is a schematic diagram of the worm gear structure in an embodiment of the present invention;

[0056] Figure 6 This is a line graph showing the clearance of the deceleration mechanism measured after endurance tests in control group 1 and control group 2 in this embodiment of the invention.

[0057] Figure 7 This is a line graph showing the loudness of the deceleration mechanism measured after durability testing in Control Group 1 and Control Group 2 in this embodiment of the invention.

[0058] Figure label:

[0059] 10. Worm gear; 11. Pitch circle; 12. Addendum circle; 13. Dedendum circle;

[0060] 100, First sensitive area; 200, Second sensitive area. Detailed Implementation

[0061] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0062] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0063] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0064] In the description of this invention, it should be noted that the terms "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0065] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0066] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0067] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0068] The reduction gear of the existing column-type electric power steering system is mainly composed of a worm gear mechanism. After long-term use, the worm gear and worm will wear down, resulting in an increase in the gap between the worm gear and worm. This causes a loose feel and abnormal noise when the vehicle is turned, affecting the driver's driving comfort and the reliability of the whole vehicle.

[0069] To eliminate the clearance that appears between the worm gear and worm after prolonged wear, previous studies have mostly adopted the method of adding a clearance compensation mechanism inside the housing to compensate for and adjust the clearance between the worm gear and worm. However, adding a clearance compensation mechanism inside the housing is not only structurally complex and costly, but may also introduce new abnormal noises.

[0070] To solve the above problems, such as Figure 1-7 As shown, this embodiment provides a method for improving abnormal noise from the steering column, including the following steps:

[0071] S1. Conduct n durability tests on the steering column; n is a natural number greater than zero;

[0072] Performing n durability tests on the steering column is equivalent to simulating the wear and tear that occurs in the early stages of normal use of the steering column.

[0073] Understandably, a torsion test bench can be used to conduct durability tests on the steering column. The torsion test bench is existing technology and can be purchased commercially.

[0074] It should be noted that this embodiment uses a torsion test bench to conduct a reverse torsion durability test on the steering column. The so-called reverse torsion durability test means fixing the input end of the steering column and loading the output end of the steering column, which is equivalent to conducting a torsion durability test on the steering column under load. This can more realistically simulate the actual working state of the steering column when it is assembled into the vehicle.

[0075] S2. Based on the experimental results, determine the first sensitive area 100 that needs improvement;

[0076] Furthermore, the first sensitive region 100 that needs improvement based on experimental results also includes:

[0077] The steering column, which has undergone n durability tests, is disassembled, and the individual components of the disassembled steering column are examined under a microscope to determine the first sensitive area 100 that needs improvement.

[0078] It should be noted that by disassembling the steering column after n durability tests and conducting microscopic observation of each component of the disassembled steering column, it is possible to identify whether each component is worn and the specific location of the wear. The worn area is then identified as the first sensitive area 100 that needs improvement.

[0079] Understandably, during prolonged use, the steering column experiences minimal wear in the early stages, resulting in no weight reduction. Therefore, after the initial durability test, the first sensitive area 100 can be determined solely through microscopic observation. The method of determining the sensitive area of ​​wear on a workpiece through microscopic observation is existing technology and will not be elaborated upon here.

[0080] Optionally, before conducting n durability tests on the steering column, the following steps are also included:

[0081] Measure the clearance of the reduction gear in the steering column.

[0082] Furthermore, after conducting n durability tests on the steering column, the following steps are also included:

[0083] Measure the clearance of the reduction gear in the steering column.

[0084] By comparing the clearance changes of the deceleration mechanism of the steering column before and after n durability tests, it can be more intuitively determined that in the early stage of normal use, wear of the steering column components will lead to changes in the clearance of the deceleration mechanism. This further confirms that the wear-prone areas identified by microscopic observation can be regarded as the first sensitive areas that need to be improved.

[0085] Optionally, before conducting n durability tests on the steering column, the following steps are also included:

[0086] Measure the loudness of the deceleration mechanism in the steering column.

[0087] Furthermore, after conducting n durability tests on the steering column, the following is also included:

[0088] Measure the loudness of the deceleration mechanism in the steering column.

[0089] By comparing the loudness changes of the deceleration mechanism of the steering column before and after n durability tests, it can be more intuitively determined that in the early stage of normal use, wear of steering column components will lead to changes in the loudness of the deceleration mechanism. This further confirms that the wear-prone areas identified by microscopic observation can be regarded as the first sensitive areas that need to be improved.

[0090] It should be noted that before conducting n durability tests on the steering column, it is sufficient to measure the clearance and loudness of the reduction gear mechanism. The clearance can be measured first, followed by the loudness; or the loudness can be measured first, followed by the clearance of the testing mechanism. Similarly, after conducting n durability tests on the steering column, it is sufficient to measure the clearance and loudness of the reduction gear mechanism. The clearance can be measured first, followed by the loudness; or the loudness can be measured first, followed by the clearance of the testing mechanism.

[0091] It is understood that the clearance of the reduction mechanism is the clearance between the worm wheel and the worm. For example, the clearance of the reduction mechanism can be measured by fixing the worm, rotating the worm wheel, and using a scaler to detect the clearance between the worm wheel and the worm. Using a scaler to detect the clearance between the worm wheel and the worm is a commonly used technique in the prior art, and will not be elaborated upon here.

[0092] For example, the method for measuring the loudness of the deceleration mechanism is as follows: rotate the input end of the steering column at a preset speed, such as 40r / min-50r / min, wait for a preset time, such as 2min, to allow the steering column to run stably, and then use a decibel meter to collect noise data at the center of gravity of the steering wheel. The value measured by the decibel meter is the loudness of the deceleration mechanism.

[0093] S3. The first sensitive area 100 is processed by laser to form the first micro-groove morphology;

[0094] Specifically, the first microgroove morphology includes multiple microgrooves with a dot-like structure.

[0095] Multiple microgrooves are etched in the first sensitive area 100 by laser to improve the surface lubrication properties of the first sensitive area 100. At the same time, the microgrooves can also store lubricant, which can further improve the wear problem of the first sensitive area 100.

[0096] It should be noted that during long-term use, the steering column will not produce abrasive particles or will produce very few abrasive particles in the early stages of wear. Therefore, the microgrooves of the first sensitive area 100 are set as dot-shaped structures, which can store both lubricant and a small number of abrasive particles, thereby improving the wear problem of the first sensitive area 100.

[0097] Furthermore, in the process of using a laser to process the first sensitive area 100 and form the first microgroove morphology, a single-pulse laser is used in order to control the microgroove of the first sensitive area 100 to have a dotted structure.

[0098] Specifically, in this embodiment, when processing the first sensitive area 100 with a laser to form the first microgroove morphology, the laser power is P1 and the pulse width is W1. Exemplarily, the value of P1 is in the range of 70W-100W; P1 can be any value between 70W and 100W, such as 70W, 75W, 80W, 85W, 90W, 95W, 100W, etc. The value of W1 is in the range of 12000μs-18000μs. W1 can be any value between 12000μs and 18000μs, such as 12000μs, 13000μs, 14000μs, 15000μs, 16000μs, 17000μs, 18000μs, etc.

[0099] S4. Perform m durability tests on the steering column that has undergone one laser treatment; m is a natural number greater than zero, and m > n;

[0100] After n durability tests, the steering column is subjected to m durability tests, which is equivalent to simulating the wear and tear that occurs in the later stages of normal use of the steering column.

[0101] S5. Based on the test results, determine the second sensitive area 200 that needs improvement;

[0102] Furthermore, the second sensitive area 200, which needs improvement based on the test results, also includes:

[0103] The steering column, which has undergone m durability tests, is disassembled, and each component of the disassembled steering column is observed under a microscope and weighed to determine the second sensitive area 200 that needs improvement.

[0104] During long-term use, the steering column will experience greater wear in the later stages. Not only will wear marks appear at the wear points of the workpiece, but abrasive particles will also be generated, resulting in a reduction in the weight of the workpiece. Therefore, after the second durability test, microscopic observation and weighing can be combined to accurately determine the sensitive areas of wear on the workpiece.

[0105] Specifically, before conducting the durability test, the steering column is disassembled and each component of the disassembled steering column is weighed. Then, after m durability tests, the steering column is disassembled again and each component of the disassembled steering column is weighed. By comparing the two weighing results, it can be determined whether the weight of the component has decreased. Combined with microscopic observation, the specific location of wear on the component can be determined. The location of wear on the component with the largest weight reduction is the second sensitive area 200 that needs to be improved.

[0106] Optionally, after performing m durability tests on the steering column, the following steps are also included:

[0107] Measure the clearance of the reduction gear in the steering column.

[0108] By comparing the clearance changes of the steering column's reduction mechanism before durability testing, after n durability tests, and after m durability tests following laser treatment, it can be more intuitively determined that in the later stages of normal use, wear on the steering column components will further lead to changes in the clearance of the reduction mechanism. This further confirms that the wear-prone areas identified through microscopic observation and weighing can be designated as the second sensitive area 200 requiring improvement.

[0109] Optionally, after performing m durability tests on the steering column, the following steps are also included:

[0110] Measure the loudness of the deceleration mechanism in the steering column.

[0111] By comparing the loudness changes of the steering column's deceleration mechanism before durability testing, after n durability tests, and after a laser-treated steering column undergoing m durability tests, it can be more intuitively determined that in the later stages of normal use, wear on the steering column components will further lead to changes in the loudness of the deceleration mechanism. This further confirms that the worn areas identified through microscopic observation and weighing can be designated as the second sensitive area 200 requiring improvement.

[0112] It should be noted that after performing m durability tests on the steering column that has undergone laser treatment once, it is only necessary to measure the clearance and loudness of the deceleration mechanism. The clearance of the deceleration mechanism can be measured first, followed by the loudness; or the loudness of the deceleration mechanism can be measured first, followed by the clearance of the detection mechanism.

[0113] S6. Use a laser to process the second sensitive area 200 and form a second micro-groove morphology;

[0114] Specifically, the second microgroove morphology includes multiple microgrooves with a linear structure.

[0115] Multiple microgrooves are etched into the second sensitive area 200 by laser, thereby improving the surface lubrication characteristics of the second sensitive area 200. At the same time, the microgrooves can also store lubricant, which can further improve the wear problem of the second sensitive area 200.

[0116] It should be noted that during long-term use, the steering column will generate slightly more abrasive particles due to wear in the later stages. Therefore, the microgrooves of the second sensitive area 200 are designed with a linear structure. Compared with microgrooves with a dotted structure, the linear structure of the microgrooves can store more abrasive particles, which helps to further improve the wear problem of the second sensitive area 200.

[0117] Furthermore, in processing the second sensitive region 200 with a laser to form the second microgroove morphology, a continuous pulse laser is used to control the microgroove of the second sensitive region 200 to have a linear structure.

[0118] Specifically, in this embodiment, when processing the second sensitive region 200 with a laser to form the second microgroove morphology, the laser power is P2 and the pulse width is W2; therefore, P1 = P2 and W1 = W2. In other words, after processing the first sensitive region 100 with a laser, it is only necessary to change the single-pulse laser to a continuous-pulse laser to start processing the second sensitive region 200. The processing steps are simple and easy to operate.

[0119] For example, the value of P2 is always between 70W and 100W; P2 can be any value between 70W and 100W, such as 70W, 75W, 80W, 85W, 90W, 95W, 100W, etc. The value of W2 is always between 12000μs and 18000μs. W2 can be any value between 12000μs and 18000μs, such as 12000μs, 13000μs, 14000μs, 15000μs, 16000μs, 17000μs, 18000μs, etc.

[0120] S7. Add lubricant to the steering column that has undergone two laser treatments.

[0121] Optionally, the amount of lubricant added is 10g-15g. For example, the amount of lubricant added can be any value between 10g and 15g, such as 10g, 11g, 12g, 13g, 14g, 15g, etc. By limiting the amount of lubricant added, excessive or insufficient lubricant is avoided, ensuring the lubrication effect.

[0122] The method for improving steering column noise provided in this embodiment, through durability testing, identifies a first sensitive area 100 and a second sensitive area 200 of the steering column that are prone to wear in the early stages and later stages of use during long-term use. The first sensitive area 100 is treated with a laser to form a first micro-groove morphology, and the second sensitive area 200 is treated with a laser to form a second micro-groove morphology. In other words, different laser micro-groove morphologies are designed for different sensitive areas, which not only improves the tribological properties of different sensitive areas but also enhances their lubricant and abrasive grain storage capabilities. This significantly improves the loose noise caused by long-term wear of the worm gear. Furthermore, compared to existing technologies, this method does not require additional components and does not increase the structural complexity of the steering system.

[0123] Figure 2 This is a detailed flowchart of the method for improving steering column noise provided in this embodiment. The following example uses 20 steering columns and combines... Figure 2 The above methods for improving abnormal noise from the steering column are described in detail.

[0124] S100, Measure the clearance and loudness of the reduction gear mechanism of 20 steering columns;

[0125] S110. Conduct 30,000 durability tests on 20 steering columns;

[0126] Under normal temperature conditions, reverse torsional durability tests were conducted on 20 steering columns using a torsional durability testing bench. The test conditions were as follows: the input end of the steering column was fixed, and a sinusoidal load was applied to the output end of the steering column with a loading torque of ±30 N·m. Specifically, the sinusoidal load was provided by a motor of the torsional durability testing bench controlled by a computer.

[0127] S120. Measure the clearance and loudness of the reduction gear mechanism of 20 steering columns;

[0128] S210. Based on the experimental results, determine the first sensitive area 100 that needs improvement;

[0129] Specifically, the steering column that had undergone 30,000 durability tests was disassembled, and the various components of the disassembled steering column were observed under a microscope to determine the first sensitive area 100 that needed improvement; it was found that the first sensitive area 100 was the area from the pitch circle 11 to the tip circle 12 of the worm gear 10 teeth.

[0130] S310. The first sensitive area 100 is processed by laser to form a first micro-groove morphology;

[0131] The laser used is a single-pulse laser with a power of 80W and a pulse width of 15000μs. The first microgroove morphology includes multiple microgrooves with a dot-like structure.

[0132] Understandably, after treating the first sensitive area 100, the steering column needs to be reassembled in order to continue the durability test.

[0133] S410. Conduct 70,000 durability tests on 20 steering columns that have undergone laser treatment once;

[0134] Under normal temperature conditions, reverse torsion durability tests were conducted on 20 steering columns using a reverse torsion durability test bench. The test conditions were as follows: the input end of the steering column was fixed, and a sinusoidal load was applied to the output end of the steering column with a loading torque of ±30 N·m.

[0135] S420, Measure the clearance and loudness of the reduction gear mechanism of 20 steering columns;

[0136] It should be noted that, Figure 3 The clearances of the reduction gears, measured in steps S100, S120, and S420 respectively, for the 20 steering columns. Figure 4 The loudness of the deceleration mechanism measured in steps S100, S120, and S420 for each of the 20 steering columns is determined by... Figure 3 and Figure 4 It can be seen that as the number of durability tests increases, the clearance of the deceleration mechanism of the steering column gradually increases, and the loudness of the deceleration mechanism also gradually increases.

[0137] S510. Based on the test results, determine the second sensitive area 200 that needs improvement;

[0138] Specifically, the steering column, which had undergone m durability tests, was disassembled, and each component of the disassembled steering column was microscopically observed and weighed to determine the second sensitive area 200 that needed improvement. It was found that the second sensitive area 200 was the region from the pitch circle 11 to the root circle 13 of the worm gear 10 teeth, as detailed in [link to details]. Figure 5 .

[0139] S610. The second sensitive area 200 is processed by laser to form a second micro-groove morphology;

[0140] The laser used is a continuous pulse laser with a power of 80W and a pulse width of 15000μs. The second microgroove morphology includes multiple microgrooves with a linear structure.

[0141] S710, Add lubricant to the steering column that has undergone two laser treatments.

[0142] After treating the second sensitive area 200, the steering column is reassembled and 10g of lubricant, such as lubricating grease, is added. This completes the processing steps of this method.

[0143] The five steering columns treated using the above method are designated as a, b, c, d, and e, respectively, serving as control group one. The five steering columns that were not treated with laser micro-shaping are designated as a1, b1, c1, d1, and e1, respectively, serving as control group two.

[0144] Reverse torsional durability tests were conducted on control group 1 and control group 2 respectively. The test conditions were as follows: the input end of the steering column was fixed, and the output end of the steering column was loaded with a sinusoidal load with a loading torque of ±30 N·m. The number of tests was 100,000.

[0145] After the experiment, the clearance of the reduction mechanism in control group 1 and control group 2 was measured respectively, and the results are as follows. Figure 6 As shown, the loudness of the deceleration mechanism in control group 1 and control group 2 was measured, and the results are as follows. Figure 7 As shown.

[0146] like Figure 6 As shown, after 100,000 reverse torsional durability tests, the clearance value of the reduction mechanism in control group two was approximately the same, fluctuating around 19'. After 100,000 reverse torsional durability tests, the clearance value of the reduction mechanism in control group one was also approximately the same, fluctuating around 13'.

[0147] like Figure 7 As shown, after 100,000 reverse torsional durability tests, the loudness decibel value of the reduction mechanism in control group two was approximately the same, around 57 dB. After 100,000 reverse torsional durability tests, the loudness decibel value of the reduction mechanism in control group one was also approximately the same, around 48 dB.

[0148] In summary, after treating the steering column using this method, the increase in clearance of the deceleration mechanism can be slowed down as the steering column is used for a longer period of time, and the noise of the deceleration mechanism can also be reduced. Compared with the steering column without this treatment, the clearance of the deceleration mechanism can be reduced by about 31.5%, and the noise of the deceleration mechanism can be reduced by about 15.8%, effectively improving the problem of looseness and abnormal noise in the steering column.

[0149] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A method for improving abnormal noise from the steering column, characterized in that, Includes the following steps: The steering column is subjected to n durability tests; n is a natural number greater than zero. Based on the experimental results, the first sensitive area that needs improvement was identified; The first sensitive area is processed using a laser to form a first micro-groove morphology; The steering column that has undergone laser treatment once is subjected to m durability tests; m is a natural number greater than zero, and m > n; Based on the test results, identify the second sensitive area that needs improvement; The second sensitive area is processed using a laser to form a second microgroove morphology; Add lubricant to the steering column that has undergone two laser treatments; The first microgroove morphology includes multiple microgrooves with a dot-like structure; the second microgroove morphology includes multiple microgrooves with a line-like structure. The first sensitive region is the area from the pitch circle to the addendum circle of the worm gear teeth; the second sensitive region is the area from the pitch circle to the root circle of the worm gear teeth.

2. The method for improving steering column noise according to claim 1, characterized in that, Prior to conducting n durability tests on the steering column, the following is also included: Measure the clearance of the reduction gear in the steering column.

3. The method for improving abnormal noise from the steering column according to claim 2, characterized in that, After the n durability tests on the steering column, the following is also included: Measure the clearance of the reduction gear in the steering column.

4. The method for improving steering column noise according to claim 3, characterized in that, After m durability tests on the steering column, the following is also included: Measure the clearance of the reduction gear in the steering column.

5. The method for improving abnormal noise from the steering column according to claim 1, characterized in that, Prior to conducting n durability tests on the steering column, the following is also included: Measure the loudness of the deceleration mechanism in the steering column.

6. The method for improving steering column noise according to claim 5, characterized in that, After the n durability tests on the steering column, the following is also included: Measure the loudness of the deceleration mechanism in the steering column.

7. The method for improving steering column noise according to claim 6, characterized in that, After m durability tests on the steering column, the following is also included: Measure the loudness of the deceleration mechanism in the steering column.

8. The method for improving abnormal noise from the steering column according to claim 1, characterized in that, The first sensitive area that needs improvement based on experimental results also includes: The steering column, having undergone n durability tests, is disassembled, and each component of the disassembled steering column is examined under a microscope to identify the first sensitive area requiring improvement; and / or, The second sensitive area that needs improvement based on the test results also includes: The steering column, which has undergone m durability tests, is disassembled, and each component of the disassembled steering column is observed under a microscope and weighed to determine the second sensitive area that needs improvement.

9. The method for improving abnormal noise from the steering column according to claim 1, characterized in that, In the process of using a laser to process the first sensitive area and form the first microgroove morphology, the laser is a single-pulse laser; and / or, In the process of using a laser to process the second sensitive area and form the second microgroove morphology, the laser used is a continuous pulse laser.

10. The method for improving abnormal noise from the steering column according to claim 9, characterized in that, In the process of using a laser to process the first sensitive area and form the first micro-groove morphology, the power of the laser is P1 and the pulse width is W1. In the process of using a laser to process the second sensitive area and form the second microgroove morphology, the power of the laser is P2 and the pulse width is W2. Then P1 = P2, W1 = W2.

11. The method for improving abnormal noise from the steering column according to claim 1, characterized in that, In the aforementioned n durability tests on the steering column, the test conditions are as follows: the input end of the steering column is fixed, and a sinusoidal load is applied to the output end of the steering column with a loading torque of ±30 N·m; and / or, In the aforementioned durability test of the steering column after one laser treatment, the test conditions are as follows: the input end of the steering column is fixed, and the output end of the steering column is loaded with a sinusoidal load with a loading torque of ±30 N·m.

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