Elastic lock bolt

Abstract

The invention provides an elastic lock bolt which comprises a body, the body comprises a bolt head and a screw rod which are sequentially connected, and a mounting part is arranged at the end, away from the screw rod, of the bolt head; the body is provided with a deep hole in the axial direction, the deep hole extends into the screw rod from the end face of the mounting part, and the tail end of the deep hole does not penetrate to the thread root of the screw rod; the bolt head comprises a conical disc section located below the installation part, and a wedge-shaped matching face used for making contact with a connected piece is formed on the peripheral face of the conical disc section. An inner hexagonal hole which is concave inwards is formed in the mounting part, the inner hexagonal hole is coaxially communicated with the deep hole, and the hole diameter of the inner hexagonal hole is larger than that of the deep hole; at least one pair of radial through holes are further formed in the mounting part; according to the elastic lock bolt, the problems that in the prior art, an elastic lock bolt is insufficient in lock stability and reliability, prone to fatigue failure and short in service life are solved.

Description

Technical Field

[0001] This invention relates to the technical field of anti-loosening bolts, and in particular to an elastic anti-loosening bolt. Background Technology

[0002] Elastic anti-loosening bolts are mechanical fasteners that use continuous axial tension generated by elastic deformation to resist dynamic loads such as vibration and impact, thereby preventing nuts or bolts from loosening.

[0003] Currently, existing elastic anti-loosening bolts have the following technical problems: 1. Insufficient anti-loosening stability and reliability: Under strong vibration, impact, or alternating loads, the restoring force of the elastic element in existing elastic anti-loosening bolts gradually weakens, leading to a decrease in preload and a significant reduction or even failure in anti-loosening effect. 2. Prone to fatigue failure and short service life: Some existing anti-loosening bolts are prone to fatigue failure under long-term cyclic loads or in areas with localized stress concentration, thereby reducing the bolt's service life. Summary of the Invention

[0004] In view of the shortcomings of the prior art described above, the technical problem to be solved by the present invention is to provide an elastic anti-loosening bolt, which solves the problems of insufficient anti-loosening stability and reliability, easy fatigue failure and short service life of the elastic anti-loosening bolt in the prior art.

[0005] To achieve the above objectives, the present invention provides an elastic anti-loosening bolt, comprising:

[0006] The body includes a bolt head and a screw connected in sequence. The bolt head has a mounting portion at one end away from the screw. The body has a deep hole along the axial direction. The deep hole extends from the end face of the mounting portion to the interior of the screw, and the end of the deep hole does not penetrate to the root of the screw thread.

[0007] The bolt head includes a tapered disc segment located below the mounting portion, the outer peripheral surface of which forms a wedge-shaped mating surface for contacting the connected component;

[0008] The mounting part is provided with an inwardly recessed hexagonal hole, which is coaxially connected with the deep hole, and the diameter of the hexagonal hole is larger than the diameter of the deep hole.

[0009] The mounting part is also provided with at least one pair of radial through holes. The two ends of the radial through holes are respectively connected to the inner wall of the internal hexagonal hole and the outer peripheral surface of the mounting part, and the central axes of at least one pair of radial through holes are located on the same straight line. When used in combination, the fasteners pass through the internal hexagonal hole and the radial through holes to connect with the external connectors to restrict the circumferential rotation of the body.

[0010] As a more preferred approach, the cone angle α of the conical disc segment ranges from 5° ≤ α ≤ 6°, and the outer diameter of the conical disc segment gradually increases from the side closer to the mounting part to the side farther away from the mounting part. Setting the cone angle α within the "self-locking angle" range of 5° ≤ α ≤ 6° ensures that when the bolt is tightened, the conical disc segment forms a tight wedge-shaped fit with the surface of the connected parts. This avoids stress concentration and slippage risks caused by excessively large angles, and also prevents loss of wedging effect due to excessively small angles, significantly improving the bolt's anti-loosening performance under dynamic loads. Furthermore, compared to traditional flat washer structures, the gradual cone angle of 5° to 6° significantly increases the actual contact area between the bolt head and the connected surface. This gradual contact method can more evenly distribute the enormous preload to the base material, preventing crushing, denting, or surface damage to soft materials (such as aluminum and composite materials) due to excessive local pressure, thereby ensuring the long-term stability of the connection. Furthermore, the outer diameter of the tapered disc section gradually increases from the mounting part outwards, forming a streamlined cross-sectional transition, which effectively eliminates stress concentration at right-angle turns. This smooth geometry prevents premature fatigue cracks at the root of the bolt when it is subjected to alternating loads or impact vibrations, thus extending the service life of the bolt body.

[0011] As a preferred approach, the lower end face of the mounting portion and the upper end face of the conical disc segment are smoothly connected by a first transition arc. Firstly, by introducing the first transition arc, the right-angle or acute-angle transition at the connection between the lower end face of the mounting portion and the upper end face of the conical disc segment can be effectively eliminated, resulting in a smooth transition in the structure. When the bolt is subjected to tensile, bending, or vibration loads, the arc transition can evenly distribute concentrated stress, significantly reducing stress peaks and thus significantly improving the fatigue life of the bolt under alternating loads, preventing cracks or fractures due to excessive local stress. Secondly, the smooth connection avoids material weaknesses caused by abrupt changes in cross-section, allowing the load to be transferred more smoothly from the mounting portion to the conical disc segment. This helps optimize the force flow path within the material, reduces the stress concentration factor, and enables the bolt head to more evenly bear and transmit preload, ensuring the long-term stable operation of the connection structure.

[0012] As a more preferred approach, the top outer periphery of the conical disc segment is provided with a second transition arc, which is tangentially connected to the wedge-shaped mating surface of the conical disc segment. By introducing the second transition arc, especially the connection method tangential to the wedge-shaped mating surface, the formation of sharp edges at the top of the conical disc segment is avoided. This not only eliminates geometric stress concentration points but also reduces the risk of microcracks in the bolt under cyclic loading, thereby significantly extending the bolt's service life under harsh working conditions. Furthermore, when the bolt is tightened, if the edge of the conical disc segment is sharp, it may embed or even scratch the surface of the connected parts under high pressure, compromising their integrity; the second transition arc provides a smooth contact starting point, ensuring uniform pressure distribution, thereby protecting the surface quality of the connected parts and guaranteeing the sealing performance and long-term stability of the connection.

[0013] As a more preferred embodiment, the bolt head further includes a neck connecting the tapered disc segment and the screw. The connection between the neck and the screw has a third transition arc, which smoothly connects to the outer circumferential surface of the tapered disc segment. In bolt structures, the connection between the screw and the bolt head is a region of high stress concentration, particularly prone to cracking under alternating loads or vibrations. By introducing the neck and the third transition arc, sharp edges at this point can be eliminated, resulting in a smoother cross-sectional change and effectively dispersing concentrated stress, thereby improving the bolt's fatigue strength and service life under dynamic conditions. Furthermore, the neck structure, combined with the smooth arc transition, provides a longer force transmission path and a larger effective load-bearing cross-section between the bolt head and the screw. This helps to transmit the tensile or shear force from the bolt head to the screw more evenly and smoothly, avoiding premature yielding or failure due to stress concentration and ensuring the overall reliability of the connection structure.

[0014] As a preferred embodiment, the inlet edge of the hexagonal socket is provided with a guide chamfer. Firstly, the guide chamfer creates a "flared" inlet at the driving end of the bolt, providing clear alignment guidance for installation tools (such as hex wrenches or sockets). This allows the tool to be inserted into the hole quickly and accurately, especially in situations with limited operating space, effectively reducing slippage and wasted travel caused by misalignment, making the assembly process smoother and more efficient. Secondly, when the tool is inserted, the chamfer avoids hard contact and collision between the tool tip and the edge of the hole, preventing burrs, chipping, or deformation at the hole opening. Simultaneously, the guide chamfer protects the tool tip from unnecessary wear or damage, extending the tool's service life.

[0015] As a preferred embodiment, a first stepped surface is formed at the junction of the bottom of the internal hexagonal hole and the top of the deep hole, and a transition chamfer is provided on the first stepped surface. The junction of the bottom of the internal hexagonal hole and the deep hole is a critical location with a sudden change in cross-section, which is prone to stress concentration. By setting the stepped surface and the transition chamfer, a smooth transition of the cross-section is achieved, effectively dispersing the stress at this point and avoiding the generation of micro-cracks caused by stress concentration. Secondly, during the machining process, the combination of the stepped surface and the chamfer can remove sharp burrs and machining marks from the bottom of the hole, preventing these defects from scratching tools (such as internal hexagonal wrenches) or affecting the smooth insertion of connecting parts (such as pins) during installation. At the same time, the chamfer also protects the edge of the bottom of the hole, avoiding chipping or deformation caused by stress concentration or assembly collisions, ensuring the accuracy and reliability of the assembly.

[0016] As a preferred approach, the multiple radial through holes are evenly distributed circumferentially along the mounting portion. When external fasteners (such as wire ropes) apply constraints to the bolts through the radial through holes, the evenly distributed through holes ensure that the constraint force is symmetrically distributed circumferentially. This avoids excessive local stress caused by load concentration, prevents deformation or breakage of the mounting portion, and thus ensures the overall stability and safety margin of the bolts under complex working conditions (such as under torque or vibration). Furthermore, by evenly arranging the through holes on the circumference, effective restriction on the circumferential rotation of the bolts can be achieved without significantly weakening the overall strength of the mounting portion. This layout makes the stress distribution more balanced, avoids weak points caused by excessive local openings, and fully utilizes the load-bearing capacity of the material. Moreover, the evenly distributed radial through holes provide a clear assembly reference for external connectors, allowing fasteners such as wire ropes to be inserted more smoothly and accurately, which helps improve assembly efficiency and reduces the risk of assembly jamming or misalignment due to hole position deviations.

[0017] As a preferred approach, the deep hole is end-featured with a tapered reaming section, the tapered surface of which converges towards the end of the screw. In traditional flat-bottomed deep holes, the bottom is typically a region of high stress concentration due to abrupt changes in cross-sectional shape and machining marks, making it highly susceptible to cracking under alternating loads. The tapered reaming section achieves a gradual transition in cross-section through a smooth tapered surface, avoiding sharp right angles or flat-bottomed structures. This disperses stress over a larger area, significantly reducing the stress concentration factor. For bolts subjected to cyclic loads (such as those in engines and transmission systems), this can significantly extend their service life. Furthermore, the converging tapered surface forms a smooth "buffer section" deep within the screw, rather than a weak flat-bottomed plane, helping to more evenly distribute the axial tensile force borne by the screw to the bolt head area, preventing localized yielding or premature fracture caused by abrupt changes in hole bottom shape. Simultaneously, this structure also provides a sealing support surface for potential internal pressures (such as hydraulic bolts), improving connection reliability.

[0018] As a more preferred approach, the depth of the hexagonal socket is greater than the axial distance between the radial through hole and the end face of the mounting portion, and the bottom of the hexagonal socket is located below the radial through hole. Because the bottom of the hexagonal socket is lower than the radial through hole, when a hexagonal tool is inserted for tightening or loosening, the effective working section of the tool is entirely below the radial through hole. This ensures that the meshing force area between the tool and the hole wall is spatially separated from the radial through hole area, avoiding hole wall deformation, extrusion damage, or stress concentration caused by the torque or radial force applied by the tool directly acting on the through hole wall, thereby guaranteeing the geometric accuracy and reliable fit of the radial through hole. Secondly, designing the bottom of the hexagonal socket to be deeper effectively avoids the problem of excessively thin local wall thickness caused by the hexagonal socket being too close to or connected to the radial through hole. This significantly improves the shear and extrusion resistance of the bolt head, especially under strong vibration or impact loads, preventing cracking or failure of the mounting portion.

[0019] As described above, the elastic anti-loosening bolt of the present invention has the following beneficial effects: When in use, the deep hole axially opened in the bolt body (extending from the end face of the mounting part to the interior of the bolt, and the end not penetrating the root of the thread) enables the bolt to have controllable elastic deformation capability when subjected to axial force. When the preload of the connecting parts decreases due to vibration, temperature fluctuations, or alternating loads, the elastic recovery of the deep hole area can automatically compensate for the loss of preload, fundamentally inhibiting bolt loosening, and is especially suitable for high vibration conditions such as engines.

[0020] The outer circumferential surface of the tapered disc section of the bolt head forms a wedge-shaped mating surface, which increases the friction area between the bolt and the connected parts after pre-tightening, thereby increasing the contact area between the bottom surface of the bolt head and the surface of the connected parts, and thus improving the overall anti-loosening ability of the bolt. In contrast, after pre-tightening, the friction area between the bolt and the connected parts of traditional bolts decreases, which reduces the contact area between the bottom surface of the bolt head and the surface of the connected parts, resulting in a decrease in the overall anti-loosening ability of the bolt. Therefore, the anti-loosening effect of the bolt in this application is superior to that of traditional bolts.

[0021] The design of the first transition arc between the mounting section and the conical disc section, the second transition arc at the top of the conical disc section, and the third transition arc connecting the neck and the screw eliminates sharp edges and abrupt changes in cross-section at the joints of various structures, making the stress distribution smoother, significantly reducing the stress concentration factor, improving the fatigue resistance of the bolts under alternating loads, and extending their service life. Attached Figure Description

[0022] Figure 1 The diagram shows the overall structure of an elastic anti-loosening bolt according to the present invention.

[0023] Figure 2 The diagram shown is a cross-sectional view of an elastic anti-loosening bolt according to the present invention.

[0024] Figure 3 Displayed as Figure 2 A magnified view of a portion of point A in the middle;

[0025] Figure 4 The image shown is a top view schematic diagram of an elastic anti-loosening bolt according to the present invention.

[0026] Component designation explanation

[0027] 1 Ontology 11 Bolt head 111 Installation Department 1111 Hexagonal socket 1112 radial through hole 112 Conical disk segment 12 screw 13 deep hole 131 tapered expansion section 14 First transition arc 15 Second transition arc 16 Third transition arc Detailed Implementation

[0028] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0029] It should be understood that the structures, proportions, sizes, etc., illustrated in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and are not intended to limit the implementation of the invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of the invention, should still fall within the scope of the disclosed technical content. The following detailed description should not be considered restrictive, and the scope of the embodiments of this application is limited only by the claims of the published patents. The terminology used herein is for describing specific embodiments only and is not intended to limit the application. Spatial terms such as "upper," "lower," "left," "right," "below," "below," "lower part," "above," "upper part," etc., may be used in the text to illustrate the relationship between one element or feature shown in the figures and another element or feature.

[0030] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," "fixing," and "holding" 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; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0031] Furthermore, as used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context indicates otherwise. It should be further understood that the terms “comprising,” “including,” indicate the presence of the stated feature, operation, element, component, item, kind, and / or group, but do not preclude the presence, occurrence, or addition of one or more other features, operations, elements, components, items, kinds, and / or groups. The terms “or” and “and / or” as used herein are interpreted as inclusive, or mean any one or any combination thereof. Thus, “A, B, or C” or “A, B, and / or C” means “any one of: A; B; C; A and B; A and C; B and C; A, B, and C.” Exceptions to this definition arise only when combinations of elements, functions, or operations are inherently mutually exclusive in some manner.

[0032] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the invention.

[0033] like Figures 1 to 4 As shown, the present invention provides an elastic anti-loosening bolt, comprising:

[0034] The body 1 includes a bolt head 11 and a screw 12 connected in sequence. The bolt head 11 has a mounting portion 111 at one end away from the screw 12. The body 1 has a deep hole 13 along the axial direction. The deep hole 13 extends from the end face of the mounting portion 111 into the interior of the screw 12, and the end of the deep hole 13 does not penetrate to the root of the thread of the screw 12.

[0035] The bolt head 11 includes a tapered disc segment 112 located below the mounting portion 111, and the outer peripheral surface of the tapered disc segment 112 forms a wedge-shaped mating surface for contacting the connected component.

[0036] The mounting part 111 is provided with an inwardly recessed hexagonal hole 1111, which is coaxially connected with the deep hole 13, and the diameter of the hexagonal hole 1111 is larger than the diameter of the deep hole 13.

[0037] The mounting portion 111 is also provided with at least one pair of radial through holes 1112. The two ends of the radial through holes 1112 are respectively connected to the inner wall of the internal hexagonal hole 1111 and the outer peripheral surface of the mounting portion 111, and the central axes of at least one pair of radial through holes 1112 are located on the same straight line. When used in combination, the fasteners pass through the internal hexagonal hole 1111 and the radial through holes 1112 to connect with the external connector to restrict the circumferential rotation of the body 1.

[0038] In some embodiments of the present invention, such as Figures 1 to 3 As shown, the cone angle α of the conical disc segment 112 ranges from 5° ≤ α ≤ 6°, and the outer diameter of the conical disc segment 112 gradually increases from the side closer to the mounting portion 111 to the side farther away from the mounting portion 111. By setting the cone angle α within the "self-locking angle" range of 5° ≤ α ≤ 6°, when the bolt is tightened, the conical disc segment 112 forms a tight wedge-shaped fit with the surface of the connected part. This avoids stress concentration and slippage risks caused by excessively large angles, and also prevents loss of wedging effect due to excessively small angles, significantly improving the bolt's anti-loosening performance under dynamic loads. Furthermore, compared to traditional flat washer structures, the 5° to 6° gradual cone angle significantly increases the actual contact area between the bolt head 11 and the connected surface. This gradual contact method allows the enormous preload to be distributed more evenly across the base material, preventing crushing, denting, or surface damage to soft materials (such as aluminum and composite materials) due to excessive local pressure, thus ensuring the long-term stability of the connection. Furthermore, the outer diameter of the tapered disc section 112 gradually increases outward from the mounting portion 111, forming a streamlined cross-sectional transition. This effectively eliminates stress concentration at right-angle bends. This smooth geometry prevents premature fatigue cracking at the bolt root when subjected to alternating loads or impact vibrations, extending the service life of the bolt body 1.

[0039] In some embodiments of the present invention, such as Figures 2 to 3 As shown, the lower end face of the mounting portion 111 and the upper end face of the conical disc segment 112 are smoothly connected by a first transition arc 14. Firstly, by introducing the first transition arc 14, the right-angle or acute-angle transition at the connection between the lower end face of the mounting portion 111 and the upper end face of the conical disc segment 112 can be effectively eliminated, allowing for a smooth transition in the structure. When the bolt is subjected to tensile, bending, or vibration loads, the arc transition can evenly distribute the concentrated stress, significantly reducing the stress peak value, thereby significantly improving the fatigue life of the bolt under alternating loads and preventing cracks or fractures due to excessive local stress. Secondly, the smooth connection method avoids material weaknesses caused by abrupt changes in cross-section, allowing the load to be transferred more smoothly from the mounting portion 111 to the conical disc segment 112. This helps optimize the force flow path within the material, reduces the stress concentration coefficient, and allows the bolt head 11 to more evenly bear and transmit the preload, ensuring the long-term stable operation of the connection structure.

[0040] In some embodiments of the present invention, such as Figure 3As shown, the top outer peripheral edge of the conical disc segment 112 is provided with a second transition arc 15, which is tangentially connected to the wedge-shaped mating surface of the conical disc segment 112. By introducing the second transition arc 15, especially the connection method tangential to the wedge-shaped mating surface, the formation of sharp edges at the top of the conical disc segment 112 is avoided. This not only eliminates geometric stress concentration points but also reduces the risk of microcracks in the bolt under cyclic loading, thereby significantly extending the bolt's service life under harsh working conditions. Furthermore, when the bolt is tightened, if the edge of the conical disc segment 112 is sharp, it may embed or even scratch the surface of the connected parts under high pressure, compromising their integrity, especially for soft materials, such as aluminum and plastic substrates. The second transition arc 15 provides a smooth contact starting point, ensuring uniform pressure distribution, thereby protecting the surface quality of the connected parts and ensuring the sealing and long-term stability of the connection.

[0041] In some embodiments of the present invention, such as Figures 2 to 3 As shown, the bolt head 11 also includes a neck connecting the conical disc segment 112 and the screw 12. A third transition arc 16 is provided at the connection between the neck and the screw 12, and the third transition arc 16 smoothly contacts the outer circumferential surface of the conical disc segment 112. In the bolt structure, the connection between the screw 12 and the bolt head 11 is a region of high stress concentration, especially prone to cracking under alternating loads or vibrations. By introducing the neck and the third transition arc 16, sharp edges at this location can be eliminated, making the cross-sectional change more gradual, thereby effectively dispersing the concentrated stress and improving the fatigue strength and service life of the bolt under dynamic conditions. Furthermore, the neck structure, combined with the smooth arc transition, provides a longer force transmission path and a larger effective load-bearing cross-section between the bolt head 11 and the screw 12. This helps to transmit the tensile or shear force from the bolt head 11 to the screw 12 more evenly and smoothly, avoiding premature yielding or failure due to stress concentration and ensuring the overall reliability of the connection structure.

[0042] In some embodiments of the present invention, such as Figure 1 and Figure 4As shown, the inlet edge of the hexagonal socket 1111 is provided with a guide chamfer. Firstly, the guide chamfer forms a "flared" inlet at the driving end of the bolt, providing clear alignment guidance for installation tools (such as hexagonal wrenches or sockets). This allows the tool to be inserted into the hole quickly and accurately, especially in situations with limited operating space, effectively reducing slippage and idle travel caused by misalignment, making the assembly process smoother and more efficient. Secondly, when the tool is inserted, the chamfer avoids hard contact and collision between the tool tip and the edge of the hole, preventing burrs, chipping, or deformation at the hole opening. Simultaneously, the guide chamfer protects the tool tip from unnecessary wear or damage, extending the tool's service life.

[0043] In some embodiments of the present invention, such as Figures 1 to 2 As shown, a first stepped surface is formed at the connection between the bottom of the internal hexagonal hole 1111 and the top of the deep hole 13, and a transition chamfer is provided on the first stepped surface. The connection between the bottom of the internal hexagonal hole 1111 and the deep hole 13 is a critical location with a sudden change in cross-section, which is prone to stress concentration. By setting the stepped surface and the transition chamfer, a smooth transition of the cross-section is achieved, effectively dispersing the stress at this point and avoiding the generation of micro-cracks caused by stress concentration. Secondly, during the machining process, the combination of the stepped surface and the chamfer can remove sharp burrs and machining marks from the bottom of the hole, preventing these defects from scratching tools (such as internal hexagonal wrenches) or affecting the smooth insertion of connecting parts (such as pins) during installation. At the same time, the chamfer also protects the edge of the bottom of the hole, avoiding chipping or deformation caused by stress concentration or assembly collision, ensuring the accuracy and reliability of the assembly.

[0044] In some embodiments of the present invention, such as Figures 1 to 2 As shown, multiple radial through holes 1112 are evenly distributed circumferentially along the mounting portion 111. When external fasteners (such as wire ropes) apply constraints to the bolts through the radial through holes 1112, the evenly distributed through holes ensure that the constraint force is symmetrically distributed circumferentially. This avoids excessive local stress caused by load concentration, prevents deformation or breakage of the mounting portion 111, and thus ensures the overall stability and safety margin of the bolts under complex working conditions (such as under torque or vibration). Furthermore, by evenly arranging through holes on the circumference, effective restriction on the circumferential rotation of the bolts can be achieved without significantly weakening the overall strength of the mounting portion 111. This layout makes the stress distribution more balanced, avoids weak points caused by excessive local openings, and fully utilizes the load-bearing capacity of the material. Furthermore, the evenly distributed radial through holes 1112 provide a clear assembly reference for external connectors, allowing fasteners such as wire ropes to be inserted more smoothly and accurately, which helps improve assembly efficiency and reduces the risk of assembly jamming or misalignment caused by hole position deviations.

[0045] In some embodiments of the present invention, such as Figure 2As shown, the deep hole 13 has a tapered expanding section 131 at its end, with the tapered surface of the tapered expanding section 131 converging towards the end of the screw 12. In a conventional flat-bottomed deep hole 13, the bottom is typically a region of high stress concentration due to abrupt changes in cross-sectional shape and machining marks, making it prone to cracking under alternating loads. The tapered expanding section 131 achieves a gradual transition of the cross-section through its smooth tapered surface, avoiding sharp right angles or flat-bottomed structures, thereby dispersing stress over a larger area and significantly reducing the stress concentration factor. For bolts subjected to cyclic loads (such as those in engines and transmission systems), this significantly extends their service life. Furthermore, the converging tapered surface forms a smooth "buffer section" deep within the screw 12, rather than a weak flat-bottomed plane, helping to more evenly transmit the axial tensile force borne by the screw 12 to the bolt head 11 area, preventing localized yielding or premature fracture caused by abrupt changes in the hole bottom shape. Simultaneously, this structure also provides a sealing support surface for potential internal pressures (such as hydraulic bolts), improving the reliability of the connection.

[0046] In some embodiments of the present invention, such as Figures 1 to 2 As shown, the depth of the internal hexagonal hole 1111 is greater than the axial distance between the radial through hole 1112 and the end face of the mounting part 111, and the bottom of the internal hexagonal hole 1111 is located below the radial through hole 1112. Because the bottom of the internal hexagonal hole 1111 is lower than the radial through hole 1112, when an internal hexagonal tool is inserted for tightening or loosening, the effective working section of the tool is completely below the radial through hole 1112. This ensures that the meshing force area between the tool and the hole wall is spatially separated from the area of ​​the radial through hole 1112, avoiding hole wall deformation, extrusion damage, or stress concentration caused by the torque or radial force applied by the tool directly acting on the through hole wall, thereby ensuring the geometric accuracy and reliable fit of the radial through hole 1112. Secondly, designing the bottom of the internal hexagonal hole 1111 to be deeper effectively avoids the problem of excessively thin local wall thickness caused by the internal hexagonal hole 1111 being too close to or connected to the radial through hole 1112. This significantly improves the shear and crush resistance of the bolt head 11, especially when subjected to strong vibration or impact loads, preventing the mounting part 111 from cracking or failing.

[0047] As described above, the elastic anti-loosening bolt of the present invention has the following beneficial effects: When the elastic anti-loosening bolt of the present invention is used, the deep hole 13 axially opened in the body 1 (extending from the end face of the mounting part 111 to the interior of the screw 12, and the end does not penetrate the root of the thread) enables the bolt to have controllable elastic deformation capability when subjected to axial force. When the preload of the connecting part decreases due to vibration, temperature fluctuation or alternating load, the elastic recovery of the deep hole 13 area can automatically compensate for the loss of preload, fundamentally suppressing bolt loosening, and is especially suitable for high vibration conditions such as engines.

[0048] The outer circumferential surface of the tapered disc segment 112 of the bolt head 11 forms a wedge-shaped mating surface, which increases the friction area between the bolt and the connected parts after pre-tightening, thereby increasing the contact area between the bottom surface of the bolt head 11 and the surface of the connected parts, and thus improving the overall anti-loosening ability of the bolt. In contrast, after pre-tightening, the friction area between the bolt and the connected parts of a traditional bolt decreases, which reduces the contact area between the bottom surface of the bolt head 11 and the surface of the connected parts, resulting in a decrease in the overall anti-loosening ability of the bolt. Therefore, the anti-loosening effect of the bolt in this application is better than that of traditional bolts.

[0049] The design of the first transition arc 14 between the mounting part 111 and the conical disc section 112, the second transition arc 15 at the top of the conical disc section 112, and the third transition arc 16 connecting the neck and the screw 12 eliminates sharp edges and abrupt changes in cross-section at the joints of various structures, making the stress distribution smoother, significantly reducing the stress concentration factor, improving the fatigue resistance of the bolt under alternating loads, and extending its service life.

[0050] In summary, the elastic anti-loosening bolt of the present invention has the following advantages:

[0051] 1. Long service life:

[0052] The design of the first transition arc 14 between the mounting part 111 and the conical disc section 112, the second transition arc 15 at the top of the conical disc section 112, and the third transition arc 16 connecting the neck to the screw 12 eliminates sharp edges and abrupt changes in cross-section at the joints of various structures, making the stress distribution smoother, improving the fatigue resistance of the bolt under alternating loads, and extending the service life of the bolt.

[0053] 2. It has a good anti-loosening effect:

[0054] The outer circumferential surface of the tapered disc section 112 of the bolt head 11 forms a wedge-shaped mating surface. Unlike traditional bolts, which reduce the friction area between the bolt and the connected parts after pre-tightening, resulting in a smaller contact area between the bottom surface of the bolt head 11 and the surface of the connected parts and lower bolt anti-loosening ability, the bolt of this application increases the friction area between the bolt and the connected parts after pre-tightening, thereby increasing the contact area between the bottom surface of the bolt head 11 and the surface of the connected parts, and thus significantly improving the overall anti-loosening ability of the bolt.

[0055] 3. Excellent elasticity and anti-loosening ability:

[0056] The deep hole 13 axially opened in the body 1 enables the bolt to have controllable elastic deformation capability when subjected to axial force. When the preload of the connection decreases due to vibration, temperature fluctuation or alternating load, the elastic recovery of the deep hole 13 area can automatically compensate for the loss of preload, fundamentally inhibiting bolt loosening.

[0057] In summary, this invention effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0058] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A resilient anti-loosening bolt, characterized in that, include: The body includes a bolt head and a screw connected in sequence. The bolt head has a mounting portion at one end away from the screw. The body has a deep hole along the axial direction. The deep hole extends from the end face of the mounting portion to the interior of the screw, and the end of the deep hole does not penetrate to the root of the screw thread. The bolt head includes a tapered disc segment located below the mounting portion, the outer peripheral surface of which forms a wedge-shaped mating surface for contacting the connected component; The mounting part is provided with an inwardly recessed hexagonal hole, which is coaxially connected with the deep hole, and the diameter of the hexagonal hole is larger than the diameter of the deep hole. The mounting part is also provided with at least one pair of radial through holes. The two ends of the radial through holes are respectively connected to the inner wall of the internal hexagonal hole and the outer peripheral surface of the mounting part, and the central axes of at least one pair of radial through holes are located on the same straight line. When used in combination, the fasteners pass through the internal hexagonal hole and the radial through holes to connect with the external connectors to restrict the circumferential rotation of the body.

2. The elastic anti-loosening bolt according to claim 1, characterized in that: The cone angle α of the conical disk segment is in the range of 5°≤α≤6°, and the outer diameter of the conical disk segment gradually increases from the side closer to the mounting part to the side farther away from the mounting part.

3. The elastic anti-loosening bolt according to claim 1, characterized in that: The lower end face of the mounting part and the upper end face of the conical disc segment are smoothly connected by a first transition arc.

4. The elastic anti-loosening bolt according to claim 1, characterized in that: The top outer periphery of the conical disk segment is provided with a second transition arc, which is tangentially connected to the wedge-shaped mating surface of the conical disk segment.

5. The elastic anti-loosening bolt according to claim 1, characterized in that: The bolt head also includes a neck connecting the conical disc segment and the screw. A third transition arc is provided at the connection between the neck and the screw, and the third transition arc smoothly connects with the outer circumferential surface of the conical disc segment.

6. The elastic anti-loosening bolt according to claim 1, characterized in that: The inlet edge of the internal hexagonal hole is provided with a guide chamfer.

7. The elastic anti-loosening bolt according to claim 1, characterized in that: A first stepped surface is formed at the connection between the bottom of the internal hexagonal hole and the top of the deep hole, and a transition chamfer is provided on the first stepped surface.

8. The elastic anti-loosening bolt according to claim 1, characterized in that: The plurality of radial through holes are evenly distributed along the circumference of the mounting portion.

9. The elastic anti-loosening bolt according to claim 1, characterized in that: The deep hole has a tapered expansion section at its end, and the tapered surface of the tapered expansion section converges toward the end of the screw.

10. The elastic anti-loosening bolt according to claim 1, characterized in that: The depth of the internal hexagonal hole is greater than the axial distance between the radial through hole and the end face of the mounting part, and the bottom of the internal hexagonal hole is located below the radial through hole.

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