Ion nitriding anti-seepage tool and method for elastic shaft

Abstract

The invention discloses an elastic shaft ion nitriding anti-seepage tool and method.The elastic shaft ion nitriding anti-seepage tool comprises an outer side lining, an upper end blind plate, a lower end lifting table and an annular support, the outer side lining can be arranged on the periphery of a shaft body in a sleeving mode, and two splines are exposed; the upper end blind plate blocks one end of the shaft hole; the lower end lifting table extends into the other end of the shaft hole; the annular supporting ring is arranged on the periphery of the lower end lifting table in a sleeving mode and supports the lower end lifting table. By the adoption of the ion nitriding anti-seepage tool for the elastic shaft, a nitriding layer meeting the technical requirement can be formed in the spline nitriding area of the elastic shaft, meanwhile, no nitriding layer is formed in the non-nitriding area of the shaft body, and therefore the ion nitriding requirements of different areas of the elastic shaft can be met.

Description

Technical Field

[0001] The present application relates to the field of thermochemical treatment technology, and in particular to an elastic shaft ion nitriding anti-seepage tool and method. Background Art

[0002] Ion nitriding is a heat treatment method that can strengthen the surface of materials. Through a DC pulse power supply, nitrogen or ammonia and other nitrogen-containing gases are ionized, so that the excited nitrogen-containing ions penetrate into the surface of the workpiece, thereby forming a hardened layer with a hardness of up to 1000HV.

[0003] The elastic shaft is a mechanical part that is mainly used to transmit the torque, energy, etc. generated by the engine. Specifically, the splines at both ends of the transmission shaft mesh with the corresponding spline pairs to transmit power to various parts of the equipment. Currently, elastic shafts are widely used in aircraft engine transmission systems. After the elastic shaft is ion nitrided, its surface wear resistance and fatigue resistance can be greatly enhanced. However, in order to reduce the difficulty of subsequent processing steps, the shaft body and inner wall of the elastic shaft cannot be ion nitrided and strengthened. Therefore, when the elastic shaft is ion nitrided, it is currently necessary to perform anti-seepage treatment on the shaft body and inner wall surface to reduce the impact of ion nitriding on subsequent processing.

[0004] Therefore, in order to meet the ion nitriding requirements of different areas of the elastic shaft and reduce the impact of the ion nitriding process on subsequent processes, it has become a technical problem that needs to be urgently solved by those skilled in the art. Summary of the invention

[0005] The present application proposes an ion nitriding anti-permeability tooling and method for an elastic shaft, so as to reduce the impact on subsequent processes while meeting the ion nitriding requirements of different areas of the elastic shaft.

[0006] In order to achieve the above objectives, this application discloses the following technical solutions: In a first aspect, the present application provides an elastic shaft ion nitriding anti-seepage tooling, which is used for ion nitriding anti-seepage of the elastic shaft. The elastic shaft includes a shaft body with a shaft hole and splines at both ends of the shaft body. The anti-seepage tooling includes an outer bushing, an upper blind plate, a lower lifting platform and an annular support, wherein: The outer bushing can be sleeved on the outer periphery of the shaft body and expose two splines; The upper blind plate is sealed at one end of the shaft hole; The lower end lifting platform extends to the other end of the shaft hole; The annular supporting ring is sleeved on the outer periphery of the lower end lifting platform and supports the lower end lifting platform.

[0007] In some embodiments, the upper blind plate includes a plate body and a positioning portion, wherein the positioning portion is located on the plate surface of the plate body and has a conical structure to be wedge-shapedly connected to one end of the shaft hole.

[0008] In some embodiments, the diameter of the plate body is 0.7 cm smaller than the bottom circle of the spline teeth of the corresponding spline.

[0009] In some embodiments, the outer bushing is formed by splicing two semicircular bushings and fixed by a throat clamp; the inner diameter of the outer bushing is 0.05-0.3 mm larger than the outer diameter of the shaft; The length of the outer bushing is 0.01~0.1mm shorter than the distance between the two splines; The outer circumference of the outer bushing is provided with a plurality of first ribs extending in the circumferential direction and a plurality of second ribs extending in the axial direction.

[0010] In some embodiments, the lower lifting platform includes a supporting portion, an embedded portion and a connecting portion, the connecting portion connects the supporting portion and the embedded portion, the embedded portion is embedded in the axial hole, the outer diameter of the supporting portion gradually decreases towards the connecting portion; the outer diameter of the connecting portion gradually decreases towards the embedded portion.

[0011] In some embodiments, the wall thickness of the embedded portion is 7 to 10 mm; The distance between the upper end surface and the lower end surface of the support portion is 8 cm.

[0012] In some embodiments, the inner diameter of the annular support is 0.1-0.2 mm larger than the outer diameter of the lower lifting platform.

[0013] In some embodiments, the anti-seepage tooling is made of 22Cr17Ni12Mo2 austenitic stainless steel material or K418 cast high-temperature alloy material.

[0014] In a second aspect, the present application provides an elastic shaft ion nitriding anti-seepage method, the anti-seepage method uses any of the anti-seepage tooling as described above, and the anti-seepage method includes: Buckle the outer bushing onto the outer periphery of the elastic shaft; Lock the outer bushing and the shaft body; Put the annular support sleeve outside the lower end lifting platform; Insert the combination of the elastic shaft and the outer bushing into the lower end lifting platform; Cover the upper blind plate onto the upper end of the elastic shaft and the assembly is complete.

[0015] In some embodiments, the gap between the throat clamp and the outer bushing is filled with ion nitriding anti-permeability coating.

[0016] It can be seen from the above technical solution that the use of the above-mentioned elastic shaft ion nitriding anti-permeability tooling of the present application can form a nitriding layer that meets the technical requirements in the spline nitriding area of ​​the elastic shaft, while no nitriding layer is formed in the non-nitriding area of ​​the shaft body, thereby meeting the ion nitriding requirements of different areas of the elastic shaft. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some examples or embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without creative work, and the present application can also be applied to other similar scenarios based on the provided drawings. Unless it is obvious from the language environment or otherwise explained, the same reference numerals in the figures represent the same structure or operation.

[0018] Figure 1 An exploded view of an elastic shaft ion nitriding anti-permeability tooling provided in an embodiment of the present application; Figure 2 A partial diagram of an elastic shaft ion nitriding anti-seepage tooling provided in an embodiment of the present application; Figure 3 A partial diagram of an elastic shaft ion nitriding anti-seepage tooling provided in an embodiment of the present application; Figure 4 This is a magnified partial view of an elastic shaft provided in an embodiment of the present application under a high-power microscope; Figure 5 A flow chart of an elastic shaft ion nitriding anti-seepage method provided in an embodiment of the present application; Figure 6 A flow chart of an elastic shaft ion nitriding anti-seepage method provided in an embodiment of the present application; In the figure: 100-elastic shaft; 110-shaft body; 111-shaft hole; 120-spline; 200-anti-seepage tooling; 210-outer bushing; 211-first rib; 212-second rib; 220-upper blind plate; 221-plate body; 222-positioning part; 230-lower lifting platform; 231-supporting part; 232-embedded part; 233-connecting part; 240-annular support; 241-support ring; 242-positioning ring; 250-throat clamp. DETAILED DESCRIPTION

[0019] The present application will be further described in detail below in conjunction with the accompanying drawings and embodiments. It will be understood that the specific embodiments described herein are only used to explain the related application, rather than to limit the application. The described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application.

[0020] As described in the background technology, ion nitriding is a heat treatment method that can strengthen the surface of materials. Due to the high activity of nitrogen ions, it can effectively perform nitriding on various traditional difficult-to-nitrify materials such as stainless steel and titanium alloys with high alloy ratios. At the same time, after the ion nitriding process, the surface wear resistance and fatigue resistance of the material can be significantly improved.

[0021] 23Co14Ni12Cr3MoE is an ultra-high strength structural steel. After forging and a series of heat treatment processes, its tensile strength can reach 2000MPa, which is much higher than that of traditional structural steel. This type of steel is usually used in important structural parts in the aviation field, such as aircraft landing gear.

[0022] Ultra-high strength elastic shafts refer to those shafts with extremely high strength and good elasticity, which are widely used in key engineering structures.

[0023] Material selection: AerMet 100: This is an ultra-high strength steel with high chromium, nickel, cobalt and molybdenum content, with excellent strength and toughness; AF1410: Contains about 1.99% chromium, 10.05% nickel and 13.08% cobalt, and is an ultra-high strength steel; 4340 steel: This is a low-alloy ultra-high strength steel containing about 0.4% carbon, 0.62% manganese and 0.73% chromium, which can obtain ultra-high strength and appropriate toughness through heat treatment; 18Ni3Al4Mo: Contains 18% nickel, 4% aluminum and a small amount of molybdenum, and is a high-strength steel; Ferrium S53: Contains 10.0% chromium, 5.5% nickel and 14% molybdenum, as well as 1% tungsten and 0.3% vanadium, and is an ultra-high strength steel.

[0024] Structural design: The design of ultra-high strength elastic shafts needs to consider the material's microstructure and strengthening / toughening mechanism to ensure that good toughness is maintained while achieving ultra-high strength.

[0025] Special treatments: These materials often require complex heat treatment processes, such as quenching and tempering, to obtain optimal mechanical properties.

[0026] Surface strengthening treatments such as shot peening and roller pressing, as well as chemical treatments such as carburizing, nitriding, and nitriding can further improve the strength and wear resistance of the shaft.

[0027] In order to meet the ion nitriding requirements of different regions of elastic shafts, especially ultra-high strength elastic shafts, the present application provides an elastic shaft ion nitriding anti-permeability tooling (hereinafter referred to as the anti-permeability tooling) to protect the regions that do not require ion nitriding during the ion nitriding process.

[0028] See also Figures 1 to 3In order to facilitate understanding of the technical solution of the present application, the structure of the elastic shaft 100 is briefly introduced. The elastic shaft 100 includes a shaft body 110 having a shaft hole 111 and splines 120 located at both ends of the shaft body 110. Among them, the inner and outer surfaces of the shaft body 110 are areas that do not require ion nitriding, while the splines 120 are areas that require ion nitriding. For this reason, the anti-seepage tooling 200 is used in the example of the present application to achieve the above technical effect.

[0029] The anti-seepage tooling 200 includes a bushing 210, an upper blind plate 220, a lower lifting platform 230 and an annular support 240, wherein: the bushing 210 can be sleeved on the outer periphery of the shaft body 110, and two splines 120 are exposed; the upper blind plate 220 is sealed at one end of the shaft hole 111; the lower lifting platform 230 extends to the other end of the shaft hole 111; the annular support 240 is sleeved on the outer periphery of the lower lifting platform 230 and supports the lower lifting platform 230.

[0030] By using the ion nitriding anti-permeability tooling 200 of the elastic shaft 100 described above, a nitriding layer that meets technical requirements can be formed in the nitriding area of ​​the spline 120 of the elastic shaft 100, while no nitriding layer is formed in the non-nitriding area of ​​the shaft body 110, thereby meeting the ion nitriding requirements of different areas of the elastic shaft 100.

[0031] The anti-seepage tooling 200 is made of 22Cr17Ni12Mo2 austenitic stainless steel material or K418 cast high-temperature alloy material.

[0032] The upper blind plate 220 blocks one end of the shaft hole 111 to reduce the entry of ion nitrogen into the shaft hole 111 . In some examples, the upper blind plate 220 includes a plate body 221 and a positioning portion 222 , and the positioning portion 222 is located on the plate surface of the plate body 221 .

[0033] In order to improve the connection strength between the upper blind plate 220 and the shaft hole 111 , the positioning portion 222 is of a conical structure so as to be wedge-connected to one end of the shaft hole 111 .

[0034] In some embodiments, the diameter of the plate body 221 is 0.5-1 cm smaller than the bottom circle of the spline 120 teeth of the corresponding spline 120 . Preferably, the diameter of the plate body 221 is 0.7 cm smaller than the bottom circle of the spline 120 teeth of the corresponding spline 120 .

[0035] In some embodiments, the bushing 210 is formed by splicing two semicircular bushings and fixed by a throat clamp 250. In some examples, the bushing 210 can also be spliced ​​by three, four, or five fan-shaped bushings. Since the shape and surface of the bushing 210 are relatively regular, the overall temperature distribution of the bushing 210 is uniform during the ion nitriding process and will not affect the normal ion nitriding process. In addition, since the bushing 210 has basically no gaps, the occurrence of arcing during the ion nitriding process can be reduced.

[0036] In order to improve the wrapping effect of the bushing 210 , the inner diameter of the bushing 210 is 0.05-0.3 mm larger than the outer diameter of the shaft body 110 ; the length of the bushing 210 is 0.01-0.1 mm shorter than the distance between the two splines 120 .

[0037] In order to optimize the above technical solution, the outer circumference of the bushing 210 is provided with a plurality of first ribs 211 extending in the circumferential direction and a plurality of second ribs 212 extending in the axial direction.

[0038] In some embodiments, the lower end lifting platform 230 is used to support the elastic shaft 100 so that the supporting shaft is away from the electrode disk. In the figure, the lower end lifting platform 230 includes a supporting portion 231, an embedded portion 232 and a connecting portion 233, wherein the connecting portion 233 connects the supporting portion 231 and the embedded portion 232, and the embedded portion 232 is embedded in the shaft hole 111.

[0039] In order to reduce the occupied area, the outer diameter of the support part 231 gradually decreases towards the connecting part 233; the outer diameter of the connecting part 233 gradually decreases towards the embedding part 232; the distance between the upper end surface and the lower end surface of the support part 231 is 7~10cm.

[0040] In order to improve the matching stability between the embedding portion 232 and the shaft hole 111 , the outer diameter of the embedding portion 232 is slightly smaller than the hole diameter of the shaft hole 111 .

[0041] In some examples, the end of the embedding portion 232 is provided with a chamfer, and the chamfer makes it easier for the embedding portion 232 to be embedded in the shaft hole 111. The wall thickness of the embedding portion 232 is 7-10 mm; The annular support 240 includes a support ring 241 and a positioning ring 242. The shape of the inner hole of the positioning ring 242 matches the outer shape of the support portion 231. For example, the outer peripheral surface of the support portion 231 is a conical surface, and the hole wall of the inner hole of the positioning ring 242 is also a conical surface.

[0042] In order to facilitate the combination of the annular support 240 and the lower lifting platform 230 , the inner diameter of the annular support 240 is 0.1-0.2 mm larger than the outer diameter of the lower lifting platform 230 .

[0043] See also Figure 4 , Figure 4 The figure shows a partial magnified image of the elastic shaft under a microscope after the anti-seepage tooling 200 is used in the ion nitriding process, wherein part A corresponds to the nitriding area, and part B corresponds to the area not requiring nitriding. Before the ion nitriding process, part B of the elastic shaft is protected by the anti-seepage tooling, and a nitriding layer is obviously formed on part A, while no nitriding layer is formed on part B. It can be seen that the anti-seepage tooling 200 of the present application can achieve a good protective effect.

[0044] See also Figure 5and Figure 6 The present application provides an elastic shaft ion nitriding anti-seepage method, the anti-seepage method uses any of the anti-seepage tooling 200 described above, and the anti-seepage method includes: Step S1 involves the anti-seepage tooling 200 of the elastic shaft 100. Specifically, the anti-seepage tooling 200 includes a bushing 210, an upper blind plate 220, a lower lifting platform 230 and an annular support 240, wherein: the bushing 210 can be sleeved on the outer periphery of the shaft body 110, and two splines 120 are exposed; the upper blind plate 220 is sealed at one end of the shaft hole 111; the lower lifting platform 230 extends into the other end of the shaft hole 111; the annular support 240 is sleeved on the outer periphery of the lower lifting platform 230 and supports the lower lifting platform 230.

[0045] The upper blind plate 220, the bushing 210, the lower lifting platform 230 and the annular support 240 are made of 22Cr17Ni12Mo2 austenitic stainless steel.

[0046] The upper blind plate 220 of the anti-seepage tooling 200 is made of stainless steel plate, the bushing 210 is made of stainless steel plate and seamless steel pipe, and the lower lifting platform 230 and the annular support 240 are made of stainless steel forgings.

[0047] The diameter of the upper blind plate 220 in the anti-seepage tooling 200 is 0.7 cm smaller than the tooth bottom circle of the spline 120 .

[0048] The bushing 210 consists of two semicircular bushings; the inner diameter of the bushing 210 is 0.2 mm larger than the outer diameter of the elastic shaft 100; the length of the bushing 210 is 0.05 mm shorter than the distance between the upper and lower splines 120; there are 5 first ribs 211 and 3 second ribs 212 on the outside of the cover bushing 210, and the direction is perpendicular to the axial direction of the elastic shaft 100.

[0049] The wall thickness of the lower lifting platform 230 is 7-10 mm. In this example, the upper plane of the lower lifting platform 230 is 8 cm away from the cathode disk.

[0050] The inner surface of the annular support 240 is 0.2 mm larger than the diameter of the lifting platform 230 .

[0051] Step S2: making the anti-seepage tooling 200 of the elastic shaft 100. The anti-seepage tooling 200 is processed according to the above structure and material.

[0052] Step S3 is to assemble the elastic shaft 100 and the anti-seepage tool 200. Specifically, it includes: Step S31: buckle the bushing 210 onto the outer periphery of the shaft body 110 of the elastic shaft 100; Step S32: locking the bushing 210 and the shaft body 110; Step S33: Cover the annular support 240 outside the lower end lifting platform 230; Step S34: inserting the assembly of the elastic shaft 100 and the bushing 210 onto the lower end lifting platform 230; Step S35: Cover the upper end blind plate 220 onto the upper end of the elastic shaft 100, and the assembly is completed.

[0053] Step S4 is to perform ion nitriding.

[0054] In order to further improve the anti-seepage effect, the gap between the throat clamp 250 and the bushing 210 is filled with ion nitriding anti-seepage coating.

[0055] In the above, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0056] In the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B; "and / or" in this article is merely a way to describe the association relationship of associated objects, indicating that three relationships may exist, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone.

[0057] It should be noted that, for the convenience of description, only the parts related to the relevant application are shown in the drawings. In the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other.

[0058] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used, and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. The scope of application involved in the present application is not limited to the technical solution formed by a specific combination of the above-mentioned technical features, but should also cover other technical solutions formed by any combination of the above-mentioned technical features or their equivalent features without departing from the above-mentioned application concept. For example, the above-mentioned features are replaced with the technical features with similar functions disclosed in this application (but not limited to) to form a technical solution.

Claims

1. An elastic shaft ion nitriding anti-permeability tool, used for ion nitriding anti-permeability of an elastic shaft, the elastic shaft comprises a shaft body with a shaft hole and splines at both ends of the shaft body, characterized in that: The anti-seepage tooling includes an outer liner, an upper blind plate, a lower lifting platform and an annular support, wherein: The outer bushing can be sleeved on the outer periphery of the shaft body and expose the two splines; The upper end blind plate is sealed at one end of the shaft hole; The lower end lifting platform extends into the other end of the shaft hole; The annular support ring is sleeved on the outer periphery of the lower end lifting platform and supports the lower end lifting platform.

2. The anti-seepage tooling according to claim 1, characterized in that: The upper blind plate includes a plate body and a positioning portion, wherein the positioning portion is located on the plate surface of the plate body and has a conical structure to be wedge-shapedly connected to one end of the shaft hole.

3. The anti-seepage tooling according to claim 2, characterized in that: The diameter of the plate body is 0.7 cm smaller than the bottom circle of the spline teeth corresponding to the spline.

4. The anti-seepage tooling according to claim 1, characterized in that: The outer bushing is formed by splicing two semicircular bushings and fixed by a throat clamp; the inner diameter of the outer bushing is 0.05-0.3 mm larger than the outer diameter of the shaft; The length of the outer bushing is 0.01-0.1 mm shorter than the distance between the two splines; The outer circumference of the outer bushing is provided with a plurality of first ribs extending in the circumferential direction and a plurality of second ribs extending in the axial direction.

5. The anti-seepage tooling according to claim 1, characterized in that: The lower end lifting platform includes a supporting part, an embedded part and a connecting part, the connecting part connects the supporting part and the embedded part, the embedded part is embedded in the axial hole, the outer diameter of the supporting part gradually decreases towards the connecting part; the outer diameter of the connecting part gradually decreases towards the embedded part.

6. The anti-seepage tooling according to claim 1, characterized in that: The wall thickness of the embedded part is 7-10 mm; The distance between the upper end surface and the lower end surface of the support portion is 8 cm.

7. The anti-seepage tooling according to claim 1, characterized in that: The inner diameter of the annular support is 0.1-0.2 mm larger than the outer diameter of the lower lifting platform.

8. The anti-seepage tooling according to claim 1, characterized in that: The anti-seepage tooling is made of 22Cr17Ni12Mo2 austenitic stainless steel material or K418 cast high-temperature alloy material.

9. An elastic shaft ion nitriding anti-seepage method, characterized in that: The anti-seepage method uses the anti-seepage tooling as described in any one of claims 1 to 8, and the anti-seepage method includes: Buckle the outer bushing onto the outer periphery of the elastic shaft; Lock the outer bushing and the shaft body; Put the annular support sleeve outside the lower end lifting platform; Insert the combination of the elastic shaft and the outer bushing into the lower end lifting platform; Cover the upper blind plate onto the upper end of the elastic shaft and the assembly is complete.

10. The anti-seepage method according to claim 9, characterized in that: The gap between the throat hoop and the outer bushing is filled with ion nitriding anti-seepage coating.

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