Anti-loose combined bolt and assembling structure

Abstract

The utility model discloses a kind of anti-loosening combined bolt and assembly structure, anti-loosening combined bolt includes bolt body and metal spring for connecting first assembly body and second assembly body, the bolt body integrally formed with nut part, light rod part, limiting portion and screw thread part, the metal spring is sleeved in light rod part, and metal spring is between nut part and limiting portion;The utility model aims at in the thread rolling forming process of bolt body, metal spring is previously sleeved in light rod part, then rolls and forms limiting portion and screw thread part, so that the structure of bolt body is more compact, and metal spring is not easy to fall off, improves combined bolt structure stability and service life.

Description

Technical Field

[0001] This utility model relates to the technical field of bolt assembly, and in particular to a combination bolt and assembly structure for preventing loosening. Background Technology

[0002] In the field of mechanical assembly, especially in high-vibration and high-load conditions such as automobiles and rail transportation, the anti-loosening performance of bolt connections is crucial. Traditional bolt tightening methods mainly rely on the self-locking friction between the thread pairs to achieve anti-loosening. However, under long-term vibration, impact or temperature cycling, problems such as preload decay, thread pair slippage or even bolt loosening are prone to occur, which seriously affect the reliability and safety of the assembly structure.

[0003] To improve the anti-loosening performance of bolts, existing technologies often employ additional elastic elements to enhance the anti-loosening effect. For example, patent number CN202321878220.5 discloses a fastener and assembly structure. The fastener includes a screw, a head, and a spring. The screw includes a shank and a threaded portion, with the shank positioned between the head and the threaded portion. The spring is sleeved on the shank. When the two end faces of the two assemblies are about to fit tightly together, continued tightening compresses the spring at the end of the head and the countersunk hole. The spring generates a certain pressure, thereby increasing the friction between the two assemblies to ensure that the assemblies remain relatively stationary and achieve a tight fit.

[0004] The above-mentioned fastener structure is implemented in two ways depending on the selected spring type: a detachable limiting ring structure is used for screw steel springs, and a cold-forged integral limiting part structure is used for rubber springs. Since screw steel springs cannot deform radially, a detachable limiting ring structure is often used to meet the installation requirements of screw steel springs. This also means that the inner diameter of the screw steel spring must be larger than the outer diameter of the threaded part, resulting in the fastener head and shank, as well as the countersunk hole of the first assembly being too large, which is not conducive to achieving the requirements of lightweight and high-density assembly. In addition, the detachable limiting ring structure has the risk of loosening under long-term vibration conditions. Utility Model Content

[0005] To overcome the shortcomings of the prior art, the technical solution adopted by this utility model is: a combination bolt for preventing loosening, comprising a bolt body and a metal spring for connecting a first assembly and a second assembly. The bolt body is integrally formed with a nut portion, a smooth rod portion, a limiting portion and a threaded portion. The metal spring is sleeved on the smooth rod portion and is disposed between the nut portion and the limiting portion.

[0006] The present invention is further configured such that the inner diameter of the metal spring is smaller than the outer diameter of the limiting part.

[0007] The present invention is further configured such that the inner diameter of the metal spring is smaller than the outer diameter of the threaded portion.

[0008] The present invention is further configured such that the inner side of the nut portion is provided with a conical surface, and the metal spring abuts against the conical surface.

[0009] The present invention is further configured such that the metal spring is a cylindrical spring.

[0010] The present invention is further configured such that the metal spring is a disc spring.

[0011] This application also provides an assembly structure, which includes a first assembly and a second assembly, as well as a bolt body and a metal spring. Both the first assembly and the second assembly are provided with through holes through which the bolt body passes, and the first assembly is provided with countersunk holes for accommodating the metal spring.

[0012] The present invention is further configured such that, in the assembled state of the first assembly and the second assembly, the end of the nut portion and the countersunk hole compresses the metal spring.

[0013] Compared with the prior art, the beneficial effects of this utility model are: 1. During the production of the bolt body, a metal spring is pre-fitted onto the smooth rod, then a limiting part is rolled out, and finally a threaded part is rolled out, so that the metal spring is permanently fitted onto the smooth rod. By changing the production process, the metal spring is less likely to fall off, thus improving structural stability and service life.

[0014] 2. The bolt body has a more compact structure, mainly because the inner diameter of the metal spring can be smaller than the outer diameter of the threaded part, so that the outer diameter of the nut and the countersunk hole size of the first assembly will not increase by superposition, which helps to save installation space and is suitable for compact assembly occasions such as automobiles where space layout requirements are high.

[0015] The embodiments of this utility model will be further described below with reference to the accompanying drawings. Attached Figure Description

[0016] Figure 1 This is the front view of this utility model; Figure 2 This is the utility model Figure 1 A partial sectional view of the A-direction view; Figure 3 This is a schematic diagram of the combined bolt of this utility model during production; Figure 4 This is a structural diagram of the combined bolt of this utility model during assembly; Wherein: 1-bolt body, 2-metal spring, 3-nut part, 4-polished rod part, 5-limiting part, 6-threaded part, 7-conical surface, 100-first assembly, 200-second assembly, 101-through hole, 102-countersunk hole. Detailed Implementation

[0017] The embodiments of this utility model will now be described with reference to the accompanying drawings. In this process, to ensure clarity and convenience, we may exaggerate the width of lines or the size of constituent elements in the drawings.

[0018] Furthermore, the terms used below are defined based on the functions of this utility model and may vary depending on the intentions or conventions of the user or operator. Therefore, these terms are defined based on the entire contents of this specification.

[0019] like Figure 1 As shown, this utility model provides a combination bolt for preventing loosening, including a bolt body 1 for connecting a first assembly and a second assembly and a metal spring 2. The bolt body 1 is integrally formed with a nut part 3, a smooth rod part 4, a limiting part 5 and a threaded part 6. The metal spring 2 is sleeved on the smooth rod part 4 and is located between the nut part 3 and the limiting part 5.

[0020] Combination Figure 2 As shown, in this embodiment, the inner diameter of the metal spring 2 is smaller than the outer diameter of the limiting part 5, and the inner diameter of the metal spring 2 is smaller than the outer diameter of the threaded part 6. Taking an M14 bolt as an example, the length of the threaded part 6 is 29mm, the length of the smooth part 4 is 20mm and the outer diameter is 12.8mm, the inner diameter of the metal spring 2 is 13mm, and the outer diameter of the limiting part 5 is 15mm, so that the metal spring 2 will not detach from the bolt body 1. The inner side of the nut part 3 is provided with a conical surface 7, and the metal spring 2 abuts against the conical surface 7. The conical surface 7 plays an automatic centering role for the spring, ensuring that the spring keeps its axis aligned when compressed. The metal spring 2 is a cylindrical spring or a butterfly spring.

[0021] Combination Figure 3 As shown, the processing flow of the bolt body 1 of this utility model is as follows: the rod-shaped raw material is processed sequentially through a cold heading die to form the bottom circle of the nut, the outer hexagon of the nut, and the conical surface 7 of the nut. After the metal spring 2 is fitted, after heat treatment, the limiting part 5 is extruded through a thread rolling die, and the threaded part 6 is formed by thread rolling. Subsequent processes such as surface treatment can then be completed. By changing the processing flow, the metal spring 2 cannot naturally detach from the bolt body 1, thereby improving the stability of the structure.

[0022] Combination Figure 4 As shown, this application also provides an assembly structure, which includes a first assembly 100 and a second assembly 200, as well as a bolt body 1 and a metal spring 2. Both the first assembly 100 and the second assembly 200 are provided with through holes 101 through which the bolt body 1 passes. The first assembly 100 is provided with countersunk holes 102 for accommodating the metal spring 2. In the assembled state of the first assembly 100 and the second assembly 200, the nut portion 3 and the end of the countersunk hole 102 compress the metal spring 2.

[0023] In this invention, by setting a countersunk hole 102 to accommodate the metal spring 2, a phased and controllable assembly pre-tightening process is achieved. In the initial tightening stage, the metal spring 2 is in a free or slightly compressed state, allowing the operator to initially align and fit the first assembly 100 and the second assembly 200 with a small torque. After the assemblies are basically fitted, the bolt body 1 is tightened and the spring is compressed, so that it generates a continuously increasing axial pre-tightening force, thereby increasing the static friction between the first assembly 100 and the second assembly 200, ensuring that the two assemblies remain relatively stationary in the final tightening stage, eliminating false axial force, and improving the connection rigidity and anti-loosening performance of the bolt.

[0024] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A combination bolt designed to prevent loosening, comprising a bolt body (1) for connecting a first assembly and a second assembly, and a metal spring (2), characterized in that, The bolt body (1) is integrally formed with a nut part (3), a smooth rod part (4), a limiting part (5) and a threaded part (6). The metal spring (2) is sleeved on the smooth rod part (4) and is located between the nut part (3) and the limiting part (5).

2. The anti-loosening combination bolt according to claim 1, characterized in that: The inner diameter of the metal spring (2) is smaller than the outer diameter of the limiting part (5).

3. The anti-loosening combination bolt according to claim 2, characterized in that: The inner diameter of the metal spring (2) is smaller than the outer diameter of the threaded portion (6).

4. A combination bolt for preventing loosening according to claim 2 or 3, characterized in that: The inner side of the nut part (3) is provided with a conical surface (7), and the metal spring (2) abuts against the conical surface (7).

5. The anti-loosening combination bolt according to claim 1, characterized in that: The metal spring (2) is a cylindrical spring or a disc spring.

6. An assembly structure, characterized in that: The assembly structure includes a first assembly (100) and a second assembly (200), as well as a bolt body (1) and a metal spring (2) as described in any one of claims 1-5. The first assembly (100) and the second assembly (200) are both provided with a through hole (101) through which the bolt body (1) passes, and the first assembly (100) is provided with a countersunk hole (102) for accommodating the metal spring (2).

7. An assembly structure according to claim 6, characterized in that: When the first assembly (100) and the second assembly (200) are assembled, the nut (3) and the end of the countersunk hole (102) compress the metal spring (2).

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