High-strength fastening bolt structure

Abstract

The utility model discloses a high-strength fastening bolt structure which comprises a main bolt and a locking nut matched with the main bolt to achieve fastening connection of a plurality of components, the locking nut is provided with a plurality of threaded through holes in the axial circumference of the locking nut, and puller bolts are arranged in the threaded through holes in a penetrating mode and connected with the threaded through holes in a threaded mode. The screw rod end of each puller bolt abuts against the opposite end face of the head end component, and the puller bolts are hexagon socket screws. According to the structure, the hexagon socket screw is adopted to bear larger torque, and the high-strength grade of the hexagon socket screw can be better matched with the high-strength grade of the main bolt. And through the design of the concave arc part of the main bolt, collision-free tool retracting is achieved, and the thread machining precision is improved. In addition, the main bolt and the puller bolt both adopt coarse thread design, so that mounting and dismounting are convenient, and the bolt is particularly suitable for narrow space high-load scenes.

Description

Technical Field

[0001] This utility model relates to the field of mechanical connection components, and in particular to a high-strength fastening bolt structure. Background Technology

[0002] In numerous fields of mechanical equipment, engineering structures, and industrial manufacturing, reliable fastening connections between components are crucial. In traditional main bolt and lock nut connections, the preload is concentrated on the threaded contact surface between the lock nut and the main bolt, easily leading to uneven stress distribution, especially under vibration or alternating loads, which can cause loosening. Furthermore, the lock nut is in direct contact with the component, making it susceptible to plastic deformation due to localized pressure; preload adjustment relies on the tightening angle or torque of a single lock nut, making precise control difficult. To address these issues, existing technologies typically use lock nuts with top-tightening bolts, with several bolts evenly distributed along the axial circumference of the lock nut. However, these top-tightening bolts are all external hexagonal bolts, whose strength grade is limited and cannot withstand higher torques. Moreover, the main bolts are usually straight bolts, which are prone to impact after machining and retraction, affecting thread accuracy. Additionally, existing designs often use fine threads for both the main bolts and top-tightening bolts, which are prone to stripping, have poor wear resistance, low tensile strength, and are difficult to disassemble and assemble. Utility Model Content

[0003] To solve the above-mentioned technical problems, this utility model provides a high-strength fastening bolt structure, which is particularly suitable for fastening the oil chamber parts of punch presses in narrow installation spaces, and enables quick disassembly and installation at low cost.

[0004] The technical solution of this utility model is as follows: it includes a main bolt and a locking nut that cooperates with the main bolt to fasten multiple components. The locking nut has several threaded through holes along its axial circumference. A tightening bolt is threaded through and connected to the threaded through hole. The screw end of each tightening bolt abuts against the opposite end face of the first end component. The tightening bolt is an internal hex bolt.

[0005] A further technical solution is that a hardening washer is provided between the locking nut and the component, and the screw end of each locking nut abuts against the hardening washer.

[0006] A further technical solution is that the main bolt includes a concave arc portion with a different outer diameter, and the concave arc portion is concave arc-shaped.

[0007] A further technical solution is that the main bolt also includes a top and a bottom respectively provided with external threads, and the top and bottom are connected by a concave arc portion.

[0008] A further technical solution is that the top of the main bolt is threadedly connected to the locking nut, and after passing through multiple components at the bottom, its external thread engages with the preset internal thread on the end component.

[0009] A further technical solution is that the external thread at the bottom of the main bolt adopts coarse thread.

[0010] A further technical solution is that the tightening bolt uses coarse threads.

[0011] A further technical solution is that the main bolt uses coarse threads.

[0012] The further technical solution is that the main bolts are M48 with a strength grade of 12.9, and the internal hex bolts are also of a strength grade of 12.9.

[0013] The beneficial technical effects of this utility model are:

[0014] 1) By using hex socket head cap screws to withstand greater torque, and the high strength grade of the hex socket head cap screws can better match the high strength grade of the main bolts.

[0015] 2) The concave arc design of the main bolt enables collision-free tool retraction, improves the accuracy and efficiency of thread machining, reduces tool wear, and the concave arc provides significant machining advantages.

[0016] 3) By evenly distributing multiple sets of tightening bolts around the circumference, fine-tuning and uniform force distribution are achieved, avoiding local deformation.

[0017] 4) Both the main bolts and the top bolts adopt a coarse thread design, which is anti-slip, easy to install and disassemble, and can generate a large preload when pre-tightened, resulting in high connection reliability. Moreover, the coarse thread design has a lower cost.

[0018] This structure is particularly suitable for high-load scenarios in confined spaces. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0020] Figure 2 This is a schematic diagram of the specific structure of the main bolt of this utility model;

[0021] Figure 3 This is a cross-sectional schematic diagram of the present invention in use;

[0022] The components are: 1. Main bolt; 11. Top; 12. Bottom; 13. Concave arc part; 2. Lock nut; 3. Component; 4. Threaded through hole; 5. Tightening bolt; 6. Hardened washer. Detailed Implementation

[0023] In order to better understand the technical means of this utility model and to implement it in accordance with the contents of the specification, the specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit the scope of this utility model.

[0024] like Figure 1 and Figure 3 As shown, the high-strength fastening bolt structure of this utility model includes a main bolt 1 and a locking nut 2 threadedly connected to the main bolt 1.

[0025] In this embodiment, as Figure 2 This bolt structure is used to connect multiple components 3. The main bolt 1 includes a top 11 and a bottom 12 respectively provided with external threads, and a concave arc portion 13 for connecting the top 11 and the bottom 12. The concave arc portion 13 is concave arc-shaped, that is, the outer diameter of the concave arc portion is different. After the cutting tool completes the thread turning of the external threads, it can use the space provided by the concave arc portion 13 to retract the tool, which has obvious processing advantages. Since the concave arc portion 13 is an arc surface structure that is concave radially along the circumference, from the cross-sectional angle of the main bolt 1, the concave arc portion 13 is an arc shape that is concave axially along the circumference; from the longitudinal section angle of the main bolt 1, the concave arc portion 13 is connected to the top 11 and the bottom 12 through a smooth transition arc surface. During retraction, the tool moves radially to the recessed area of ​​the concave arc portion 13, and then gradually withdraws along the tangent direction of the arc surface. This avoids direct contact and collision between the tool and the machined threads, greatly improving the safety and convenience of retraction. This helps ensure the machining quality and accuracy of the main bolt 1, while also improving machining efficiency and reducing tool wear and damage. The depth and width of the concave arc portion 13 are determined according to the specific dimensions and design requirements of the main bolt 1, ensuring smooth tool retraction while maintaining the overall strength of the main bolt 1.

[0026] The internal thread of the locking nut 2 engages with the external thread of the top 11 of the main bolt 1. After the bottom 12 passes through each component 3 in sequence, its external thread engages with the preset internal thread on the end component 3.

[0027] The locking nut 2 has several threaded through holes 4 along its axial circumference. A tightening bolt 5 passes through and is threadedly connected to each threaded through hole 4. A hardening washer 6 is provided between the locking nut 2 and the end face of the first component 3. The hardening washer 6 protects the component 3 and distributes pressure evenly. During pre-tightening, the screw end of the tightening bolt 5 abuts against the hardening washer 6, generating a tightening force. This tightening force is transmitted to each component 3 through the hardening washer 6. The tightening force causes the main bolt 1 to undergo elastic deformation and be stretched, thereby generating a reverse tensile force. This reverse tensile force, together with the tightening force, forms a clamping force, locking each component 3 tightly together.

[0028] By adjusting the tightening degree of each tightening bolt 5, the position of the locking nut 2 can be finely adjusted, making the relative position and gap between each component 3 more precise. At the same time, the multiple threaded through holes 4 and tightening bolts 5 arranged along the axial circumference of the locking nut 2 can make the locking force evenly distributed on the circumference of the locking nut 2, avoiding excessive local force that could cause deformation or damage to the connection.

[0029] Preferably, the tightening bolt 5 is an internal hex bolt. Compared with the traditional external hex bolt, the internal hex bolt can withstand greater torque and is more suitable for occasions with high strength requirements.

[0030] In this embodiment, both the main bolt 1 and the tightening bolt 5 use coarse threads. That is, when the main bolt 1 is M48, it uses coarse threads with a pitch of 5mm; when the tightening bolt 5 is M12, it uses coarse threads with a pitch of 1.75mm.

[0031] To better distribute the tightening torque of the main bolt 1, especially when the tightening torque of the main bolt 1 is large, it is necessary to appropriately increase the number of threaded through holes 4 and tightening bolts 5 to ensure the reliability of the connection. Typically, the number of threaded through holes 4 and tightening bolts 5, as well as the target torque of each tightening screw, are determined based on the material of component 3, the stress conditions, and the tightening torque of the main bolt 1. In this embodiment, when the main bolt 1 is an M48 bolt with a strength grade of 12.9, several sets of hexagon socket head cap screws with a strength grade of 12.9 are used. These sets of threaded through holes 4 and tightening bolts 5 are evenly distributed on the axial circumference of the locking nut 2.

[0032] During connection, the bottom 12 of the main bolt 1 passes through each component 3 and is threaded to the end component 3. Then, the hardened washer 6 is inserted from the top 11 of the main bolt 1. Next, the lock nut 2 is screwed onto the main bolt 1. Then, several sets of tightening bolts 5 are symmetrically inserted into the corresponding threaded through holes 4 of the lock nut 2. The tightening bolts 5 are manually pre-tightened to ensure that the thread ends of all tightening bolts 5 are evenly in contact with the hardened washer 6. Then, the pre-tightening force is applied symmetrically in stages to ensure that all tightening bolts 5 reach the target torque. After the tightening bolts 5 are loaded, the lock nut 2 is manually tightened as needed.

[0033] This bolt structure is particularly suitable for connecting parts in the narrow space of a punch press oil chamber. Both the main bolt 1 and the top bolt 5 use coarse threads, which are not easy to strip, making them easy to install and disassemble. Moreover, they can generate a large preload force when preloaded, resulting in high connection reliability and low cost.

[0034] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A high-strength fastening bolt structure, characterized in that: Includes a main bolt (1) and a locking nut (2) that cooperates with the main bolt (1) to fasten multiple components (3). The locking nut (2) has several threaded through holes (4) along its axial circumference. A tightening bolt (5) is threaded through and connected to the threaded through hole (4). The screw end of each tightening bolt (5) abuts against the opposite end face of the first end component (3). The tightening bolt (5) is an internal hex bolt.

2. The high-strength fastening bolt structure according to claim 1, characterized in that: A hardening washer (6) is also provided between the locking nut (2) and the component (3), and the screw end of each locking nut (2) abuts against the hardening washer (6).

3. The high-strength fastening bolt structure according to claim 1, characterized in that: The main bolt (1) includes a concave arc portion (13) with a different outer diameter, and the concave arc portion (13) is concave arc-shaped.

4. The high-strength fastening bolt structure according to claim 3, characterized in that: The main bolt (1) also includes a top (11) and a bottom (12) respectively provided with external threads, and the top (11) and the bottom (12) are connected by a concave arc portion (13).

5. The high-strength fastening bolt structure according to claim 4, characterized in that: The top (11) of the main bolt (1) is threadedly connected to the locking nut (2), and the bottom (12) passes through multiple components (3), and its external thread engages with the preset internal thread on the end component (3).

6. The high-strength fastening bolt structure according to claim 5, characterized in that: The external thread of the main bolt (1) located at the bottom (12) is coarse thread.

7. The high-strength fastening bolt structure according to claim 1, characterized in that: The tightening bolt (5) has coarse threads.

8. The high-strength fastening bolt structure according to claim 1, characterized in that: The main bolt (1) has coarse threads.

9. The high-strength fastening bolt structure according to claim 1, characterized in that: The main bolt (1) is an M48 bolt with a strength grade of 12.9, and the internal hex bolt is also of a strength grade of 12.9.

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