Fastening bolt for cylinder cover
By setting the first thread section and the second thread section on the bolt, it is ensured that the bolt is preferred to break from the first thread section when it is subjected to gas pressure, which solves the problem of easy breakage of the bolt, and achieves the effect of convenient maintenance and cost reduction.
Patent Information
- Application Number
- CN202422226354.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-11
- Publication Date
- 2025-07-04
- Estimated Expiration
- 2034-09-11
AI Technical Summary
Existing cylinder head bolts are prone to break when subjected to gas pressure, which leads to difficult maintenance and high cost, and is difficult to remove at the fractured area.
A fastening bolt is designed, and the first thread section and the second thread section are provided on the screw. The effective cross-sectional area of the first thread section is smaller than the second thread section. The bolt is more likely to break from the first thread section when it is subjected to gas pressure, and the second thread section remains connected, making it easier to remove the broken screw.
Reduces the impact of bolt breakage, simplifies the maintenance process, reduces maintenance costs, and improves maintenance efficiency.
Smart Images
Figure CN223062865U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of bolts, and particularly relates to a fastening bolt for a cylinder head. Background Art
[0002] Currently, the existing cylinder head and cylinder are usually fastened and connected by bolts. When the cylinder head bears gas pressure, the threads on the outer wall of the bolt and the threads in the cylinder bolt hole provide the holding force. Since the gas pressure borne by the cylinder head is usually large, the front end of the bolt is subjected to the greatest force and often breaks. The fracture failure of the bolt causes the fastening force of the cylinder or valve to redistribute. In the light case, it accelerates the life loss of other surrounding bolts, and in the heavy case, it affects the use of the cylinder head and even causes the engine to be scrapped. Moreover, the fracture of the bolt usually occurs at the front end and is not easy to remove. The maintenance not only consumes labor but also has a high maintenance cost. Content of the Utility Model
[0003] In summary, to overcome the deficiencies of the prior art, the utility model provides a locking bolt that is safe and convenient to use, has a more reasonable and simple structure, and a lower cost.
[0004] To achieve the above object, the utility model provides the following technical solution: a fastening bolt for a cylinder head, including a nut and a screw rod. The screw rod is provided with a first thread section, a connecting section, and a second thread section. The first thread section is arranged at one end of the connecting section corresponding to the nut, and the second thread section is arranged at the other end of the connecting section relative to the first thread section. The effective cross-sectional area of the first thread section is smaller than that of the second thread section.
[0005] By adopting the above technical solution, since the effective cross-sectional area of the first thread section is smaller than that of the second thread section, when the bolt bears gas pressure, it is more likely to break from the first thread section rather than from the second thread section. Therefore, after the second thread section and the connecting section break, they still play a role in threaded connection, reducing the impact of bolt fracture. At the same time, since the first thread is close to the nut end and has a longer length, part of it is arranged outside the cylinder head, so it is convenient to use tools to remove the broken screw rod, making the maintenance and replacement more labor-saving.
[0006] The utility model is further arranged as follows: the pitch of the first thread section is n times that of the second thread section, where 1.8 ≤ n ≤ 2.2.
[0007] By adopting the above technical solution, when the pitch of the first thread section is n times that of the second thread section, it is ensured that when the bolt bears gas pressure, it is more likely to break from the first thread section rather than from the second thread section.
[0008] The present utility model is further configured as follows: the major diameter of the first thread section is D1, the pitch diameter of the first thread section is D, the minor diameter of the first thread section is D2, and 108% D ≤ D1 ≤ 113% D, 92% D ≤ D2 ≤ 94% D.
[0009] The present utility model is further configured as follows: the major diameter of the second thread section is d1, the pitch diameter of the second thread section is d, the minor diameter of the second thread section is d2, and 109% d ≤ d1 ≤ 114% d, 84% d ≤ d2 ≤ 88% d.
[0010] By adopting the above technical solution, the major diameter and minor diameter of the thread directly affect the strength and stiffness of the thread. When the major diameter and minor diameter of the first thread section are within this range, the rigidity and torque-bearing capacity of the thread are relatively high, while the strength of the thread will decrease. Therefore, when the bolt bears gas pressure, it is more likely to break at the first thread section. When the major diameter and minor diameter of the second thread section are within this range, the bearing capacity and use effect of the thread are ensured, and its connection performance and sealing performance are guaranteed.
[0011] The present utility model is further configured as follows: the length of the screw rod is L, the length of the first thread section is L1, and 31% L ≤ L1 ≤ 36% L.
[0012] The present utility model is further configured as follows: the length of the screw rod is L, the length of the connecting section is L2, and 28% L ≤ L2 ≤ 35% L.
[0013] The present utility model is further configured as follows: the length of the screw rod is L, the length of the second thread section is L3, and 26% L ≤ L3 ≤ 29% L.
[0014] By adopting the above technical solution, through the calculation of the lever arm, when the distribution lengths of the first thread section, the connecting section, and the second thread section are respectively within this range, on the premise of ensuring that the bolt is more likely to break at the first thread section when bearing gas pressure, the strength of the overall bolt is optimal.
[0015] The present utility model is further configured as follows: the first thread section includes a first tooth tip, and a groove is provided at the tip of the first tooth tip.
[0016] By adopting the above technical solution, the effective cross-sectional area of the first thread section is further reduced, making it more likely to break.
[0017] The embodiments describe the specific implementation manners of the present utility model. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 is a perspective view of an embodiment of the present utility model;
[0019] Figure 2 is a front view of an embodiment of the present utility model;
[0020] Figure 3 is Figure 2 an enlarged view of part A
[0021] Reference numerals: 1. nut, 2. screw rod, 21. first thread section, 211. first tooth tip, 2111. groove, 22. connecting section, 23. second thread section Detailed implementation mode
[0022] This specific embodiment is only an interpretation of the present invention, and it is not a limitation of the present invention. Those skilled in the art can make modifications to this embodiment without creative contributions according to needs after reading this specification, but as long as it is within the scope of the claims of the present invention, it is protected by the Patent Law
[0023] See the attached Figures 1-3 , a fastening bolt for a cylinder head, comprising a nut 1 and a screw rod 2. The screw rod 2 is provided with a first thread section 21, a connecting section 22 and a second thread section 23. The first thread section 21 is arranged at one end of the connecting section 22 corresponding to the nut 1, and the second thread section 23 is arranged at the other end of the connecting section 22 opposite to the first thread section 21. The effective cross-sectional area of the first thread section 21 is smaller than that of the second thread section 23
[0024] This embodiment is further provided that: the pitch of the first thread section 21 is n times that of the second thread section 23, and 1.8 ≤ n ≤ 2.2
[0025] This embodiment is further provided that: the major diameter of the first thread section 21 is D1, the middle diameter of the first thread section 21 is D, and the minor diameter of the first thread section 21 is D2, and 108% D ≤ D1 ≤ 113% D, 92% D ≤ D2 ≤ 94% D
[0026] This embodiment is further provided that: the major diameter of the second thread section 23 is d1, the middle diameter of the second thread section 23 is d, and the minor diameter of the second thread section 23 is d2, and 109% d ≤ d1 ≤ 114% d, 84% d ≤ d2 ≤ 88% d
[0027] This embodiment is further provided that: the length of the screw rod 2 is L, and the length of the first thread section 21 is L1, and 31% L ≤ L1 ≤ 36% L
[0028] This embodiment is further provided that: the length of the screw rod 2 is L, and the length of the connecting section 22 is L2, and 28% L ≤ L2 ≤ 35% L
[0029] This embodiment is further provided that: the length of the screw rod 2 is L, and the length of the second thread section 23 is L3, and 26% L ≤ L3 ≤ 29% L
[0030] In this embodiment, it is further provided that: the first threaded section 21 includes a first tooth tip 211, and a groove 2111 is provided at the tip of the first tooth tip 211.
[0031] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by terms such as "middle", "tip", "front end", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention. The above "between" not only refers to the between of orientation and position, but also includes the meaning of the interaction between different parts.
[0032] Although terms such as nut 1, screw 2, first threaded section 21, first tooth tip 211, groove 2111, connecting section 22, second threaded section 23, etc. are used more in this article, the possibility of using other terms is not excluded. Using these terms is only for more conveniently describing and explaining the essence of the present invention; interpreting them as any additional limitation is contrary to the spirit of the present invention.
Claims
1. A fastening bolt for a cylinder head, characterized in that: It includes a nut and a screw rod. A first thread section, a connecting section and a second thread section are provided on the screw rod. The first thread section is arranged at one end of the connecting section corresponding to the nut, and the second thread section is arranged at the other end of the connecting section relative to the first thread section. The effective cross-sectional area of the first thread section is smaller than that of the second thread section, and the pitch of the first thread section is n times that of the second thread section, where 1.8 ≤ n ≤ 2.
2.
2. The fastening bolt for a cylinder head according to claim 1, characterized in that: The major diameter of the first thread section is D1, the middle diameter of the first thread section is D, and the minor diameter of the first thread section is D2. 108% D ≤ D1 ≤ 113% D, 92% D ≤ D2 ≤ 94% D.
3. The fastening bolt for a cylinder head according to claim 1, characterized in that: The major diameter of the second thread section is d1, the middle diameter of the second thread section is d, and the minor diameter of the second thread section is d2. 109% d ≤ d1 ≤ 114% d, 84% d ≤ d2 ≤ 88% d.
4. A fastening bolt for a cylinder head according to claim 1, characterized in that: The length of the screw rod is L, and the length of the first thread section is L1. 31% L ≤ L1 ≤ 36% L.
5. A fastening bolt for a cylinder head according to claim 1, characterized in that: The length of the screw rod is L, and the length of the connecting section is L2. 28% L ≤ L2 ≤ 35% L.
6. The fastening bolt for a cylinder head according to claim 1, characterized in that: The length of the screw rod is L, and the length of the second thread section is L3. 26% L ≤ L3 ≤ 29% L.
7. A fastening bolt for a cylinder head according to claim 1, characterized in that: The first thread section includes a first tooth tip, and a groove is provided at the tip of the first tooth tip.