Anti-fatigue variable cross-section structure of high-temperature spring

Abstract

The utility model discloses an anti-fatigue variable cross-section structure of a high-temperature spring, which belongs to the technical field of high-temperature springs and comprises a thick diameter, a middle diameter is arranged at the top end of the thick diameter, a thin diameter is arranged at the top end of the middle diameter, slopes of the thick diameter, the middle diameter and the thin diameter are gradually reduced, and micro bosses are arranged at joints of two ends of the middle diameter and the thick diameter as well as the thin diameter. The conical spring is composed of the large diameter, the middle diameter and the small diameter, each section adopts a gradient curve with different slopes, stress is released in stages, in addition, the spring adopts a hollow structure design, the weight is reduced, meanwhile, the flexural rigidity is optimized by adjusting the wall thickness, and the service life is prolonged. Micro-bosses are machined in variable cross-section transition areas at the joints of the large diameter, the middle diameter and the small diameter, controllable micro-stress is introduced to inhibit crack initiation, in addition, radial micro-grooves are formed in the variable cross-section transition areas, airflow heat dissipation is promoted at high temperature, solid lubricating agents are arranged in the grooves in advance, transient thermal shock energy is absorbed, the temperature fluctuation amplitude is reduced, and thermal fatigue is inhibited.

Description

TECHNICAL FIELD

[0001] The utility model relates to a variable cross section structure, in particular to a high temperature spring anti -fatigue variable cross section structure belongs to high temperature spring technical field. BACKGROUND

[0002] The anti -fatigue design of high temperature spring is the key technical problem of industrial field, especially in aerospace, energy power, automobile engine etc. high temperature environment, spring needs to bear the alternating load and resists high temperature creep, oxidation and fatigue fracture, and the traditional circular / rectangular section moment of inertia is fixed, stress distribution is uneven, and the variable cross section structure improves stress distribution through optimizing geometric shape, which is an important means to improve the anti -fatigue performance of high temperature spring;

[0003] Therefore, a high temperature spring anti -fatigue variable cross section structure is designed to optimize the above problems. INVENTION CONTENTS

[0004] The main purpose of the utility model is to provide a kind of high temperature spring anti -fatigue variable cross section structure to solve the problems raised in the above background.

[0005] The purpose of the utility model can be achieved by adopting the following technical scheme:

[0006] A kind of high temperature spring anti -fatigue variable cross section structure, including thick diameter, the top of thick diameter is equipped with intermediate diameter, the top of intermediate diameter is equipped with thin diameter, the slope of thick diameter, intermediate diameter and thin diameter gradually decreases, micro boss is equipped at the connection of the both ends of intermediate diameter and thick diameter, thin diameter, the middle of thick diameter, intermediate diameter and thin diameter are all equipped with circular through slot, and the inner diameter of circular through slot gradually changes with the outer diameter.

[0007] Preferably, the outer side of thick diameter, intermediate diameter and thin diameter is equipped with radial micro groove, and the inside of radial micro groove is pre-placed with solid lubricant.

[0008] Preferably, radial micro groove is etched by laser, and the width is 100-200 μm.

[0009] Preferably, the height of micro boss is 0.1~0.3mm, and the width is 1~3mm.

[0010] Preferably, thick diameter is transitioned to intermediate diameter with a 15° taper angle, intermediate diameter is transitioned to thin diameter with a 10° taper angle, and thin diameter is transitioned to the end with a 5° taper angle.

[0011] Compared with the prior art, the utility model has the advantages that:

[0012] 1、The utility model discloses a tapered spring composed of thick diameter, intermediate diameter and thin diameter, each section adopts a gradually changing curve with different slope, and stress is released in stages, in addition, the spring adopts a hollow structure design, which reduces weight and optimizes bending stiffness by adjusting wall thickness.

[0013] 2, the utility model discloses a micro boss is processed to the variable cross section transition area at the connection of coarse diameter, intermediate diameter and fine diameter, and the crack initiation is inhibited by introducing controllable micro stress, and in addition, the radial micro groove is set in the variable cross section transition area, the airflow heat dissipation is promoted under high temperature, and the solid lubricant is preset in the groove, absorbs transient thermal shock energy, reduces temperature fluctuation amplitude and inhibits thermal fatigue. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 It is the front view of the utility model, and

[0015] Figure 2 It is the intermediate diameter section view of the utility model.

[0016] In the drawing: 1, coarse diameter, 2, intermediate diameter, 3, fine diameter, 4, micro boss, 5, circular through groove, 6, radial micro groove. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical scheme and advantage of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be described clearly and completely in conjunction with the drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all the embodiments.

[0018] Therefore, the following detailed description of the embodiments of the utility model is not intended to limit the scope of the claimed utility model, but only represents some embodiments of the utility model. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the utility model.

[0019] It should be noted that the embodiments in the utility model and the features and technical solutions in the embodiments can be combined with each other without conflict.

[0020] It should be noted that: similar signs and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0021] In the description of the utility model, it needs to explain, the terms "upper", "lower" and other indicated position or location relationship is based on the position or location relationship shown in the drawing, or is the position or location relationship of the invention product when using the usual place, or is the position or location relationship that the person skilled in the art usually understands, these terms are only for the convenience of describing the utility model and simplifying the description, and not indicate or imply that the device or element indicated must have a particular orientation, construct and operate with a particular orientation, therefore, it can not be understood as the limitation of the utility model.In addition, the terms "first", "second" and the like are only used for distinguishing description, and can not be understood as indicating or implying relative importance.

[0022] Embodiment 1

[0023] As Figure 1 , Figure 2 shown, the present embodiment proposes a high-temperature spring fatigue-resistant variable cross-section structure, the top end of the coarse diameter 1 is provided with the intermediate diameter 2, the top end of the intermediate diameter 2 is provided with the fine diameter 3, and the slopes of the coarse diameter 1, the intermediate diameter 2 and the fine diameter 3 gradually decrease;

[0024] The bottom end diameter D1 of the coarse diameter 1 is 10~20mm, the axial length L1 is 20~50mm, the top end diameter D2 corresponding to the taper angle 15° is D1×cos15° (8.66~17.32mm), the bottom end diameter D2 of the intermediate diameter 2 is consistent with the top end of the coarse diameter 1, the top end diameter D3 is D2×cos10° (8.53~17.02mm), the axial length L2 is 15~30mm, the bottom end diameter D3 of the fine diameter 3, the top end diameter D4 is D3×cos5° (8.47~16.89mm), and the axial length L3 is 10~20mm;

[0025] According to the elasticity mechanics, the stress concentration coefficient Kt of the variable cross-section spring is related to the cross-section change rate, the cross-section change rate of the coarse diameter 1 to the intermediate diameter 2 (15° taper angle) is relatively large, preferentially bears the main load and releases part of the stress, the intermediate diameter 2 to the fine diameter 3 (10° taper angle) further disperses the remaining stress, and the fine diameter 3 end (5° taper angle) gently transitions, so that the stress gradient is reduced to the minimum, and through the segmented slope decreasing design, the maximum stress concentration coefficient can be reduced by 30%~50% compared with the traditional equal cross-section spring;

[0026] The connection places of the two ends of the intermediate diameter 2 with the coarse diameter 1 and the fine diameter 3 are all provided with micro bosses 4;

[0027] The micro boss 4 introduces a compressive stress layer (depth 0.05~0.1mm) through local plastic deformation, according to the fracture mechanics, the compressive stress can inhibit crack initiation and propagation, and when the alternating load acts, the micro stress field of the boss 4 region can improve the crack propagation threshold ΔKth;

[0028] A circular through groove 5 is arranged at the middle of the coarse diameter 1, the intermediate diameter 2 and the fine diameter 3, and the inner diameter of the circular through groove 5 gradually changes with the outer diameter.

[0029] The inner diameter d1 of the coarse diameter section of the circular through groove 5 is D1 / 2~2D1 / 3, the inner diameter d2 of the intermediate diameter section is d1×(D2 / D1), and the inner diameter d3 of the fine diameter section is d2×(D3 / D2), so as to ensure that the inner diameter and the outer diameter gradually change by the same proportion.

[0030] The spring is made of GH4169 (nickel-based high-temperature alloy, temperature resistance 650℃, tensile strength ≥1220MPa) or Inconel718, which meets the requirements of anti-creep and anti-oxidation at high temperature, and the surface is treated by nitriding (nitriding layer thickness 0.05~0.1mm, surface hardness ≥1000HV), which improves the surface fatigue resistance.

[0031] Embodiment 2

[0032] The scheme in embodiment 1 will be further introduced in combination with a specific working mode, which is described in detail as follows:

[0033] As shown in Figure 2 , as a preferred embodiment, on the basis of the above-mentioned mode, further, the outer side of the coarse diameter 1, the intermediate diameter 2 and the fine diameter 3 is provided with a radial micro groove 6, the inside of the radial micro groove 6 is pre-installed with a solid lubricant, the solid lubricant is molybdenum disulfide, which is filled in the radial micro groove 6, and has a high temperature resistance of up to 400℃, a friction coefficient of 0.03~0.06, and can form a lubricating film at high temperature, thereby reducing the contact stress and wear. At high temperature, the radial micro groove 6 can increase the surface heat dissipation area, and the airflow in the groove can reduce the local temperature through heat convection. The solid lubricant softens under thermal shock, fills the micro gap of the contact interface, absorbs impact energy, and reduces the amplitude of contact stress fluctuation.

[0034] As shown in Figure 2 , as a preferred embodiment, on the basis of the above-mentioned mode, further, the radial micro groove 6 is laser etched, with a width of 100-200μm, a groove depth of 0.05~0.1mm, and a groove spacing of 0.5~1mm.

[0035] As shown in Figure 1 , as a preferred embodiment, on the basis of the above-mentioned mode, further, the height of the micro boss 4 is 0.1~0.3mm, the width is 1~3mm, and the cross section of the micro boss 4 is half-elliptical.

[0036] As shown in Figure 1 , as a preferred embodiment, on the basis of the above-mentioned mode, further, the coarse diameter 1 is transitioned to the intermediate diameter 2 at a taper angle of 15°, the intermediate diameter 2 is transitioned to the fine diameter 3 at a taper angle of 10°, and the fine diameter 3 is transitioned to the end at a taper angle of 5°.

[0037] The above merely illustrates the further embodiments of the present application, but the protection scope of the present application is not limited thereto, any skilled person in the art can make equivalent replacement or change according to the technical scheme and concept of the present application within the disclosed scope, which all falls into the protection scope of the present application.

Claims

1. A high-temperature spring fatigue-resistant variable cross-section structure comprising a thick diameter (1), characterized in that: The top end of the thick diameter (1) is provided with an intermediate diameter (2), the top end of the intermediate diameter (2) is provided with a thin diameter (3), the slopes of the thick diameter (1), the intermediate diameter (2) and the thin diameter (3) gradually decrease, the two ends of the intermediate diameter (2) are provided with micro bosses (4) at the connecting positions of the thick diameter (1) and the thin diameter (3), the middle positions of the thick diameter (1), the intermediate diameter (2) and the thin diameter (3) are all provided with circular through grooves (5), and the inner diameters of the circular through grooves (5) gradually change synchronously with the outer diameters.

2. A high-temperature spring with fatigue-resistant variable cross-section according to claim 1, characterized in that: The outer sides of the thick diameter (1), the intermediate diameter (2) and the thin diameter (3) are all provided with radial micro grooves (6), and the interiors of the radial micro grooves (6) are all pre-installed with solid lubricants.

3. A high-temperature spring with fatigue-resistant variable cross-section according to claim 2, characterized in that: The radial micro grooves (6) are laser etched, and the width is 100-200 μm.

4. The high-temperature spring with fatigue-resistant variable cross-section according to claim 1, characterized in that: The height of the micro boss (4) is 0.1-0.3 mm, and the width is 1-3 mm.

5. The high-temperature spring with fatigue-resistant variable cross-section according to claim 1, characterized in that: The thick diameter (1) is transitioned to the intermediate diameter (2) at a 15° taper angle, the intermediate diameter (2) is transitioned to the thin diameter (3) at a 10° taper angle, and the thin diameter (3) is transitioned to the end at a 5° taper angle.

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