A torque test method for checking the reasons for the relaxation of locomotive wheel tires

Abstract

The present invention relates to a torque test method for inspecting the cause of locomotive wheel tyre relaxation, including the steps of developing and configuring a torque test device, assembling the torque test device, a torque test process, and analyzing test data. The present invention establishes a precedent for finding the root cause of wheel tyre relaxation accidents from the source of wheel manufacturing, and fills the technical gap of torque testing for inspecting the cause of wheel tyre relaxation; the development of the technical solution of the present invention solves the problem that there is no direct detection method for wheel tyre relaxation prevention in the production and manufacturing process of locomotive wheels, and no quality certification in this regard is performed, and the quality of wheel products cannot be guaranteed; the application of the technical solution of the present invention completely changes the production bad habit of not promptly handling the anti-rust oil of the inner ring of the wheel tyre and the outer ring of the wheel core during the wheel assembly process, clarifies the reduction of torque transmission between the wheel core and the wheel tyre and the cause of wheel tyre relaxation, and improves the product quality and service life of locomotive wheels.

Description

Technical Field

[0001] The present invention relates to the technical field of wheel tyre relaxation testing, and particularly to a torque test method for checking the reasons for the relaxation of locomotive wheel tyres. Background Art

[0002] When a locomotive wheel is a structure composed of a wheel core and a wheel tyre, the interference fit between the wheel core and the wheel tyre is assembled together by means of hot fitting. At present, there is no detection means to certify whether the quality of preventing relaxation (radial misalignment) between the wheel core and the wheel tyre after assembly is qualified before the actual operation of the wheel. If the wheel core and the wheel tyre of the wheel show a relaxation phenomenon during the operation of the locomotive, it will directly affect the operation safety of the locomotive. Therefore, how to find out the accident reasons from the manufacturing source before the problem of wheel tyre relaxation occurs in the locomotive wheel, timely change the production process, ensure the product quality of the wheel in operation, and fill the technical gap in testing the reasons for wheel tyre relaxation is a key problem to be solved urgently.

[0003] At present, during the hot fitting production process of the wheel core and the wheel tyre of the wheel, due to the lack of any detection means for quality assurance in preventing wheel tyre relaxation, it is a serious technical gap. If mistakes occur during manufacturing, it will directly affect the operation safety of the locomotive and even cause serious loss accidents. The current technical solutions that can be adopted are only to draw obvious relaxation lines at the mating surface of the wheel core and the wheel tyre of the wheel (as Figure 1 shown), which is convenient for observing and judging whether there is a relaxation phenomenon of radial misalignment in the drawn lines between the wheel core and the wheel tyre during operation. If it is found that the drawn lines have radial misalignment after the wheel runs, it means that the locomotive wheel has a wheel tyre relaxation phenomenon, which belongs to a serious wheel assembly quality problem and must be dealt with emergently; if the position of the drawn lines remains unchanged after the wheel runs, it indicates that the assembly quality of the wheel core and the wheel tyre of the wheel is qualified and reliable, which belongs to the normal condition of the wheel product. With the continuous development of the output of locomotive products, continuously strengthening the analysis of the reasons for locomotive accidents, improving the quality of locomotive products, and ensuring the operation safety of locomotives are important topics and tasks that we must face and complete.

[0004] In summary, in the existing manufacturing process, there is no direct detection method for preventing the relaxation of the wheel tyre, nor is it possible to conduct quality certification in this regard. In particular, there is a technological process that cannot be ignored in the assembly of the wheel tyre. That is, after the processing of the wheel tyre and the wheel core is completed, a layer of metal protective agent is usually applied to the processed surfaces of the inner ring of the wheel tyre and the outer ring of the wheel core to prevent rusting between the wheel core and the wheel tyre before assembly, resulting in a situation where assembly cannot be carried out. If the anti-rust oil on the inner ring of the wheel tyre and the outer ring of the wheel core cannot be cleaned in time during the process of hot assembling the wheel tyre, or if there are rust impurities on the inner and outer rings of the wheel core and the wheel tyre: Will it affect the change in the interference fit between the two, thereby weakening the assembly strength of the wheel? Will it affect the torque transmission between the wheel core and the wheel tyre, thereby causing the relaxation phenomenon of the radial misalignment of the wheel tyre? These uncertain quality factors are the biggest defects that cannot guarantee the quality of the wheel product due to the lack of prior experimental certification means and no pre-production test verification. Therefore, it is of great significance to develop a torque test method for detecting the cause of wheel tyre relaxation of locomotive wheels. Summary of the Invention

[0005] In view of the above problems, the purpose of the present invention is to provide a torque test method for detecting the cause of wheel tyre relaxation of locomotive wheels, establishing a precedent for finding the root cause of wheel tyre relaxation from the source of wheel manufacturing, and filling the technical gap in torque testing for detecting the cause of wheel tyre relaxation.

[0006] The technical solution adopted by the present invention is as follows:

[0007] A torque test method for detecting the cause of wheel tyre relaxation of locomotive wheels proposed by the present invention includes the following steps:

[0008] S1. Develop and prepare four groups of identical torque test devices for simulating the wheel core and the wheel tyre of the wheel; the torque test device is composed of five components: an outer ring, an inner ring, an inner core hexagon head, a hydraulic torque wrench, and a reaction arm block; among them, the outer ring is used to simulate the wheel tyre, and the inner ring is used to simulate the wheel core; a reaction arm block is provided at the edge of the outer ring; the inner core hexagon head is arranged at the center of the inner ring;

[0009] S2. The assembly conditions of the torque test device are: the outer ring and the inner ring simulate the wheel tyre and the wheel core and are processed with an interference fit of 0.140 mm - 0.145 mm; any medium is applied to the surfaces of the inner and outer rings of two groups of torque test devices, and there is no medium on the surfaces of the inner and outer rings of the other two groups of torque test devices; the four groups of torque test devices simulate the assembly process of the wheel product and are assembled together by heating the outer ring respectively.

[0010] S3. Use a hydraulic torque wrench to twist the inner core hexagon head at the center of the inner ring, and apply the reaction moment point on the reaction force arm block at the edge of the outer ring, so that the test piece has a tendency to rotate relative to each other, and respectively test the load-bearing torque capacity of the torque test device under two working conditions, and record the torque value of the hydraulic torque wrench when the relative rotation critical point of the two workpieces occurs;

[0011] S4. By comparing the four groups of test data, judge the influence of the medium smeared on the surface of the tyre on the torque value, so as to test whether the medium on the surface of the tyre is the cause of tyre relaxation.

[0012] The present invention has the following beneficial effects compared with the prior art:

[0013] 1. The present invention has established a precedent for finding the root cause of tyre relaxation accidents from the source of wheel manufacturing, filling the technical gap in torque testing for checking the cause of tyre relaxation of wheels.

[0014] 2. The research and development of the technical solution of the present invention solves the problem that there is no direct detection means for preventing tyre relaxation of locomotive wheels during the production and manufacturing process, no quality certification in this regard, and the product quality of wheels cannot be guaranteed.

[0015] 3. The application of the technical solution of the present invention has completely changed the production habit of not cleaning the rust preventive oil on the inner ring of the tyre and the outer ring of the wheel core in time during the wheel assembly process, clarified the reasons for the reduction of torque transmission between the wheel core and the tyre and the occurrence of tyre relaxation, and improved the product quality and service life of locomotive wheels.

[0016] 4. Practice has proved that the research and development of the technical solution of the present invention has a novel design concept, is effective and practical in operation, effectively improves the production quality and use effect of wheel products, is a very practical innovative technology, plays its due role in the manufacture of locomotive wheels, and can be well applied in practice. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic structural diagram of an existing locomotive wheel;

[0018] Figure 2 It is a schematic structural diagram of the torque test device used in the method of the present invention.

[0019] Among them, the reference numerals: 1 - tyre; 2 - wheel core; 3 - relaxation line; 4 - axle; 5 - outer ring; 6 - inner ring; 7 - inner core hexagon head; 8 - hydraulic torque wrench; 9 - reaction force arm block. DETAILED DESCRIPTION OF THE INVENTION

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0021] It should be noted that in the description of the present invention, the orientation or positional relationship indicated by the terms "upper", "lower", "top", "bottom", "one side", "the other side", "left", "right", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating that the device or component must have a specific orientation, be constructed and operated in a specific orientation.

[0022] A torque test method for detecting the reasons for the relaxation of locomotive wheel tires proposed by the present invention includes the following steps:

[0023] S1. In order to compare the torque bearing capacities of the simulated wheel cores and tire ring mating surfaces with and without metal protective agents, four identical torque test devices for simulating wheel cores and tire rings are developed and prepared. As Figure 2 shown, the torque test device consists of five components: an outer ring 5, an inner ring 6, an inner core hexagon head 7, a hydraulic torque wrench 8, and a reaction arm block 9. Existing locomotive wheels are as Figure 1 shown, where the outer ring 5 simulates the tire ring 1, the inner ring 6 simulates the wheel core 2, a reaction arm block 9 is provided at the edge of the outer ring 5, and an inner core hexagon head 7 is arranged at the center of the inner ring 6;

[0024] S2. The assembly conditions of the torque test device are as follows: The outer ring 5 and the inner ring 6 simulate the tire ring 1 and the wheel core 2 and are processed with an interference amount of 0.140 mm - 0.145 mm; Any protective medium is applied to the surfaces of the inner and outer rings of two of the torque test devices, and there is no medium on the surfaces of the inner and outer rings of the other two torque test devices; The four torque test devices simulate the assembly process of the wheel products and are assembled together by heating the outer ring 5 respectively;

[0025] S3. Test principle: Use the hydraulic torque wrench 8 to twist the inner core hexagon head 7 at the center of the inner ring 6, and apply the reaction moment point to the reaction arm block 9 at the edge of the outer ring 5 to make the test piece have a tendency to rotate relative to each other. Respectively test the torque bearing capacities of the torque test device under two working conditions, and record the torque values of the hydraulic torque wrench 8 at the critical point of relative rotation of the workpiece under the two working conditions;

[0026] S4. By comparing the four groups of test data, judge the influence of the surface protective medium on the torque value, so as to test whether the surface protective medium is the reason for the relaxation of the tire ring.

[0027] The method of the present invention will be further described below through a specific example:

[0028] S1. Develop and prepare four identical torque test devices for simulating the wheel hub and tire. As shown in the figure, the torque test device consists of five components: an outer ring 5, an inner ring 6, an inner core hexagon head 7, a hydraulic torque wrench 8, and a reaction arm block 9. The existing locomotive wheels are as shown in the figure, where the outer ring 5 simulates the tire 1, the inner ring 6 simulates the wheel hub 2, a reaction arm block 9 is provided at the edge of the outer ring 5, and an inner core hexagon head 7 is arranged at the center of the inner ring 6; Figure 2 As shown in the figure, the outer ring 5 simulates the tire 1, the inner ring 6 simulates the wheel hub 2, a reaction arm block 9 is provided at the edge of the outer ring 5, and an inner core hexagon head 7 is arranged at the center of the inner ring 6; Figure 1 As shown in the figure, the outer ring 5 simulates the tire 1, the inner ring 6 simulates the wheel hub 2, a reaction arm block 9 is provided at the edge of the outer ring 5, and an inner core hexagon head 7 is arranged at the center of the inner ring 6;

[0029] S2. First, for the torque test devices with an interference of 0.140 mm - 0.145 mm, apply an antirust agent to the surfaces of the inner and outer rings of two of the groups, and there is no medium on the surfaces of the inner and outer rings of the other two groups. According to the assembly process of the wheel hub and tire, use the hot-fitting method of heating the outer ring 5 to assemble the torque test devices together;

[0030] S3. For each group of torque test devices, use the hydraulic torque wrench 8 to twist the inner core hexagon head 6 at the center of the inner ring 6, and apply the reaction force at the reaction arm block 9 at the edge of the outer ring 5, so that the torque test device has a tendency to rotate relative to each other, and record the torque value of the hydraulic torque wrench 8 when the relative rotation critical point of each group of torque test devices occurs;

[0031] The specific test operation is as follows: Before the test starts, set the torque value of the hydraulic torque wrench 8, start the hydraulic torque wrench 8, and keep it for more than 5 seconds. Observe whether the relaxation line is misaligned. If it is misaligned, stop the test of this group and record the torque value; if it is not misaligned, continue to increase the torque value until misalignment occurs or the limit value of the hydraulic torque wrench 8, 4200 N·m, is reached.

[0032] The test results are recorded as follows:

[0033]

[0034] S4. Test conclusion: Through the analysis of the above test results, for the two groups of torque test devices with no medium on the surface, they did not rotate when the torsional moment reached the limit value of the hydraulic wrench, 4200 N·m. For the two groups of torque test devices with a metal protective agent applied to the surface, they rotated when the torsional moment was between 3500 N·m and 3800 N·m.

[0035] The test results show that the torque values of the two groups with the metal protective agent medium are significantly smaller than those of the two groups with no medium; it can be concluded that the presence or absence of the metal protective agent medium directly affects the change in torque values; thus, it can be concluded that before hot-fitting the tire, it is necessary to clean the antirust medium on the inner surface of the tire, otherwise, it will affect the problem of tire relaxation during the operation of the wheel.

[0036] When there is a metal protectant on the mating surface, the friction coefficient decreases, resulting in a decrease in torque-bearing capacity and a great risk of wheel tyre relaxation.

[0037] Matters not detailed in the present invention are well-known technologies.

[0038] The embodiments described above are only descriptions of the preferred embodiments of the present invention and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A torque test method for inspecting the reasons for the relaxation of locomotive wheel tires, characterized in that, The steps include the following: S1. Develop and prepare four identical torque test devices for simulating the wheel core and tyre; The torque test device consists of five components: an outer ring, an inner ring, an inner core hexagon head, a hydraulic torque wrench and a reaction arm block. Among them, the outer ring is used to simulate the tyre, and the inner ring is used to simulate the wheel core. A reaction arm block is provided at the edge of the outer ring. The inner core hexagon head is arranged at the center of the inner ring; S2. The assembly conditions of the torque test device are as follows: the outer ring and the inner ring simulate the tyre and the wheel core and are machined with an interference amount of 0.140 mm - 0.145 mm. Any medium is applied to the surfaces of the inner and outer rings of two of the torque test devices, and no medium is applied to the surfaces of the inner and outer rings of the other two torque test devices. The four torque test devices simulate the assembly process of the wheel product and are assembled together by heating the outer ring respectively; S3. Use the hydraulic torque wrench to twist the inner core hexagon head at the center of the inner ring, and apply the reaction moment point to the reaction arm block at the edge of the outer ring to make the test pieces tend to rotate relative to each other. Test the load-bearing torque capacity of the torque test device under two working conditions respectively, and record the torque value of the hydraulic torque wrench at the critical point when the two workpieces rotate relatively; S4. By comparing the four groups of test data, judge the influence of the medium applied to the tyre surface on the torque value, so as to test whether the medium on the tyre surface is the cause of tyre relaxation.

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