Fastening bolt and design method thereof

Abstract

The invention discloses a fastening bolt and a design method thereof, and belongs to the technical field of bolts, the fastening bolt comprises a bolt head, and the bolt head comprises a first bolt head, a connecting element and a second bolt head; one end of the rod part is connected with one of the first end of the first bolt head and the first end of the second bolt head, the fastening bolt is placed in the internal thread, a tool matched with the first bolt head is utilized to rotate and fasten the fastening bolt, and when the fastening torque reaches a target value, the fastening bolt can be rotated to be fastened. And when the connecting element reaches the stress limit, the connecting element is automatically broken, and the bolt fastening torque is a target value. Meanwhile, the first bolt head falls off, only the second bolt head is left for fastening, and the second bolt head is consistent with a common bolt in form, so that the function of the second bolt head is consistent with that of the common bolt during later disassembly and maintenance, the effect that the bolt is fastened by using a single tool and preset torque can be achieved is achieved, and a special tool is replaced.

Description

Technical Field

[0001] The invention discloses a fastening bolt and a design method thereof, belonging to the technical field of bolts. Background Art

[0002] Bolt tightening is used in many fields, such as automobile, aerospace, machinery and electrical, etc. Most bolt tightening has strict requirements on tightening torque.

[0003] Traditional bolt tightening requires the use of special tools, such as torque wrenches, to meet torque requirements. During the tightening process, it is often necessary to first tighten with an ordinary wrench, and then use a torque wrench to check the torque. The above work has the following disadvantages: 1. The operator's work experience is needed to determine the torque during the pre-tightening process, which may result in excessive torque, causing damage to the thread and inaccurate torque calibration; 2. When checking the torque, it is necessary to switch tools, such as torque wrenches, which increases the work procedures and working hours; 3. The torque wrench will have numerical deviations during long-term use; 4. When checking the torque with a torque wrench, visual observation is required, which is prone to torque deviations. Summary of the Invention

[0004] The purpose of the present invention is to solve the problem that in the existing tightening process, it is often necessary to first tighten with an ordinary wrench and then use a torque wrench to check the torque, and to propose a fastening bolt and a design method thereof.

[0005] The problem to be solved by the present invention is achieved by the following technical solutions:

[0006] A fastening bolt, comprising: a bolt head, the bolt head comprising a first bolt head, a connecting element, and a second bolt head, the first bolt head and the second bolt head being spaced apart, the first bolt head and the second bolt head being connected together via the connecting element, the first bolt head having an initial position in which the first bolt head is connected to the second bolt head via the connecting element, and the first bolt head having a separation position in which the first bolt head is separated from the second bolt head;

[0007] A rod portion, one end of which is connected to one of the first end of the first bolt head and the first end of the second bolt head.

[0008] Furthermore, a head groove is provided at the second end of at least one of the first bolt head and the second bolt head.

[0009] Furthermore, the head grooves include at least a slot, a cross slot and a hexagonal socket slot.

[0010] Furthermore, the connecting element includes a plurality of connecting elements, and the plurality of connecting elements are arranged in an array between the first bolt head and the second bolt head.

[0011] A method for designing a fastening bolt, applied to the above-mentioned fastening bolt, comprises:

[0012] Obtaining a preset yield strength, a preset applied torque, a preset number of connection elements, a preset bolt head size, and a preset bolt shank size;

[0013] determining a fracture cylindrical radius at a connection between any one of the plurality of connecting elements and the second bolt head based on the predetermined yield strength, the predetermined applied torque, and the predetermined number of connecting elements;

[0014] Based on the fracture cylinder radius, the preset bolt head size and the preset bolt shank size, computational structural mechanics simulation is used to adjust the limit sizes of the preset bolt head, the preset bolt shank and the connecting element respectively.

[0015] 3. The method for designing a fastening bolt according to claim 1, wherein, based on the preset yield strength, the preset applied torque, and the preset number of connecting elements, determining the fracture cylindrical radius at the connection between any one of the plurality of connecting elements and the second bolt head comprises:

[0016] The preset yield strength, the preset applied torque, and the preset number of connection elements are used to obtain the fracture cylindrical radius at the connection between any one of the plurality of connection elements and the second bolt head through the formula:

[0017]

[0018] Where: r is the radius of the fracture cylinder, T is the preset applied torque, σ is the preset yield strength, and n is the preset number of connection elements.

[0019] The present invention has the following beneficial effects compared with the prior art:

[0020] The present invention discloses a fastening bolt and a design method thereof. The fastening bolt is placed into an internal thread and rotated and tightened using a tool that matches the first bolt head. When the tightening torque reaches a target value, the connecting element reaches its stress limit and automatically breaks. At this point, the bolt tightening torque is the target value. Simultaneously, the first bolt head falls off, leaving only the second bolt head for tightening. Because the second bolt head is consistent in form with an ordinary bolt, it functions the same as an ordinary bolt during subsequent disassembly and maintenance. This achieves the effect of achieving a predetermined torque using a single tool for bolt tightening, thereby replacing the use of specialized tools. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is an isometric view of a first embodiment of a fastening bolt of the present invention.

[0022] Figure 2It is an isometric view of a second embodiment of a fastening bolt of the present invention.

[0023] Figure 3 The present invention is a fastening bolt Figure 2 Enlarged view of point A.

[0024] Among them, 10 is a bolt head, 101 is a first bolt head, 102 is a connecting element, 103 is a second bolt head, and 20 is a rod. DETAILED DESCRIPTION

[0025] The following is based on the attached Figure 1-3 The present invention will be further described:

[0026] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0027] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the present invention.

[0028] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0029] The first embodiment of the present invention provides a fastening bolt based on the existing technology, including:

[0030] The bolt head 10 and the shank 20, the bolt head 10 includes a first bolt head 101, a connecting element 102 and a second bolt head 103, the first bolt head 101 and the second bolt head 103 are arranged at intervals, the first bolt head 101 and the second bolt head 103 are connected together by the connecting element 102, the first bolt head 101 has an initial position connected to the second bolt head 103 by the connecting element 102, and the first bolt head 101 has a separation position separated from the second bolt head 103, one end of the shank 20 is connected to one of the first end of the first bolt head 101 and the first end of the second bolt head 103.

[0031] In this embodiment, a fastening bolt is inserted into the internal thread and, using a tool compatible with the first bolt head 101, the fastening bolt is rotated and tightened. When the tightening torque reaches the target value, the connecting element 102 reaches its stress limit and automatically breaks. At this point, the bolt tightening torque reaches the target value. Simultaneously, the first bolt head 101 falls off, leaving only the second bolt head 103 for tightening. Because the second bolt head 103 is similar in form to a common bolt, it functions like a common bolt during subsequent disassembly and repair. This allows the bolt to be tightened to the desired torque using a single tool, thus replacing the need for specialized tools.

[0032] Furthermore, a head groove is provided at the second end of at least one of the first bolt head 101 and the second bolt head 103. The head groove can be used as a "positioning and force transmission interface" of the tool (for example, it is designed as a hexagonal socket, a cross slot, a slotted slot or a special special-shaped slot) to ensure that the tool and the bolt head fit better during tightening or disassembly, thereby reducing the risk of slipping. Especially in the tightening stage of the first bolt head 101, the groove can stably transmit torque, avoid torque errors caused by tool slippage, ensure that the connecting element 102 breaks accurately under the preset torque, and improve the tightening accuracy. The integrity of the groove can be used as a "visual indicator" of the bolt status: if the groove of the second bolt head 103 is worn or deformed, it can be intuitively judged whether the bolt has been forcibly disassembled, which is convenient for maintenance personnel to quickly check whether the equipment has been tampered with.

[0033] Furthermore, the connecting element 102 includes a plurality of connecting elements 102, which are arranged in an array between the first bolt head 101 and the second bolt head 103. The arrangement of the connecting elements 102 in an array between the first bolt head 101 and the second bolt head 103 allows for uniform stress transfer between the two, ensuring synchronous fracture when the target torque is reached, thereby improving torque control accuracy. The redundant structure formed by the array design can maintain the connection when some elements fail unexpectedly, enhancing reliability. At the same time, this arrangement can flexibly adapt to different torque requirements by adjusting the number and distribution of elements. The residual part after fracture is smaller, reducing space occupation and structural interference, and facilitating standardized processing during mass production, further optimizing the performance and practicality of the bolt.

[0034] The second embodiment of the present application provides a design method of a fastening bolt on the basis of the first embodiment, applied to the fastening bolt described above, comprising:

[0035] Step S10, obtaining a preset yield strength, a preset torque, a preset number of connecting elements, a preset bolt head size and a preset bolt rod size;

[0036] Step S20, determining the fracture cylindrical radius of the connection between any one of the plurality of connecting elements and the second bolt head based on the preset yield strength, the preset torque and the preset number of connecting elements;

[0037] Wherein, the fracture cylindrical radius of the connection between any one of the plurality of connecting elements and the second bolt head is obtained by formula 1 through the preset yield strength, the preset torque and the preset number of connecting elements:

[0038]

[0039] Wherein: r is the fracture cylindrical radius, T is the preset torque, σ is the preset yield strength, and n is the preset number of connecting elements.

[0040] Step S30, based on the fracture cylindrical radius, the preset bolt head size and the preset bolt rod size, adjusting the limit size of the preset bolt head, the preset bolt rod and the connecting element respectively by using computational structural mechanics simulation.

[0041] By formula 1, the yield strength, torque and connecting element size are associated in the application, the fracture radius calculation is more accurate, the bolt can be reliably fractured under the target torque, and the torque control accuracy is improved. The preset number of connecting elements as a variable supports rapid adjustment of bolt specifications, improves design flexibility and production efficiency. Combined with computational structural mechanics simulation, the bolt head and rod size are further optimized under the premise of meeting the fracture performance, material redundancy is reduced, and lightweight design is realized. The simulation adjustment process can expose stress concentration points in advance, avoid weak links in traditional experience design, and improve the fatigue resistance of the bolt. The parameterized formula and simulation process can be integrated into the CAD system to support automatic generation of customized bolt models, shorten the research and development cycle, and are especially suitable for fields such as aerospace and new energy vehicles that have strict performance requirements for fasteners.

[0042] Although the embodiments of the present application have been disclosed as above, they are not limited to the applications listed in the specification and embodiments. It can be fully applied to various fields suitable for the present application. Additional modifications can be easily made by those skilled in the art. Therefore, the present application is not limited to specific details and examples shown and described herein without departing from the general concept defined by the claims and their equivalent scope.

Claims

1. A fastening bolt, characterized in that: include: A bolt head (10), the bolt head (10) comprising a first bolt head (101), a connecting element (102) and a second bolt head (103), the first bolt head (101) and the second bolt head (103) being spaced apart, the first bolt head (101) and the second bolt head (103) being connected together via the connecting element (102), the first bolt head (101) having an initial position in which it is connected to the second bolt head (103) via the connecting element (102), and the first bolt head (101) having a separation position in which it is separated from the second bolt head (103); A rod portion (20), one end of which is connected to one of the first end of the first bolt head (101) and the first end of the second bolt head (103).

2. The fastening bolt according to claim 1, characterized in that A head groove is provided at the second end of at least one of the first bolt head (101) and the second bolt head (103).

3. The fastening bolt according to claim 2, characterized in that: The head grooves include at least a slot, a cross slot and a hexagonal slot.

4. The fastening bolt according to any one of claims 1 to 3, characterized in that: The connecting element (102) includes a plurality of connecting elements (102), and the plurality of connecting elements (102) are arranged in an array between the first bolt head (101) and the second bolt head (103).

5. A method for designing a fastening bolt, applied to the fastening bolt according to any one of claims 1 to 4, characterized in that: include: Obtaining a preset yield strength, a preset applied torque, a preset number of connection elements, a preset bolt head size, and a preset bolt shank size; determining a fracture cylindrical radius at a connection between any one of the plurality of connecting elements and the second bolt head based on the predetermined yield strength, the predetermined applied torque, and the predetermined number of connecting elements; Based on the fracture cylinder radius, the preset bolt head size and the preset bolt shank size, computational structural mechanics simulation is used to adjust the limit sizes of the preset bolt head, the preset bolt shank and the connecting element respectively.

6. The method for designing a fastening bolt according to claim 5, characterized in that: Determining the fracture cylindrical radius at a connection between any one of the plurality of connecting elements and the second bolt head based on the preset yield strength, the preset applied torque, and the preset number of connecting elements includes: The preset yield strength, the preset applied torque and the preset number of connection elements are used to obtain the fracture cylindrical radius at the connection between any one of the plurality of connection elements and the second bolt head through formula (1): Where: r is the radius of the fracture cylinder, T is the preset applied torque, σ is the preset yield strength, and n is the preset number of connection elements.

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