阅读说明：本技术 一种适用大预紧力的紧固螺栓结构 (Fastening bolt structure suitable for large pretightening force ) 是由 李刚 刘恺 周恩民 王亚 滕文江 闫羽佳 于 2020-12-22 设计创作，主要内容包括：本发明公开了一种适用大预紧力的紧固螺栓结构,包括螺栓头和工具扳手头,所述螺栓头上均匀开设有四个卡接齿,每个卡接齿的底边为22.5°的圆弧,每个卡接齿的侧边为直线结构；所述工具扳手头的端部设有与所述卡接齿匹配的卡接突。本发明能够实现对于电机转子极靴板大预紧力的紧固。(The invention discloses a fastening bolt structure suitable for large pretightening force, which comprises a bolt head and a tool spanner head, wherein four clamping teeth are uniformly arranged on the bolt head, the bottom edge of each clamping tooth is a 22.5-degree circular arc, and the side edge of each clamping tooth is of a linear structure; the end part of the tool wrench head is provided with a clamping protrusion matched with the clamping teeth. The invention can realize the fastening of large pretightening force on the pole shoe plate of the motor rotor.)

1. The utility model provides a be suitable for fastening bolt structure of big pretightning force, includes bolt head and instrument spanner head, its characterized in that:

four clamping teeth are uniformly arranged on the bolt head, the bottom edge of each clamping tooth is a 22.5-degree arc, and the side edge of each clamping tooth is of a linear structure;

the end part of the tool wrench head is provided with a clamping protrusion matched with the clamping teeth.

2. The fastening bolt structure applicable to high pre-tightening force according to claim 1, wherein a fit clearance between the clamping protrusion and the clamping tooth is less than 0.5 mm.

Technical Field

The invention relates to a fastening bolt structure applicable to large pretightening force, which is used in the field of motor manufacturing.

Background

At present, a pole shoe plate of a motor rotor is fastened by a bolt structure, because a pole shoe plate hole is enlarged, a common hexagon head bolt cannot be adopted, and therefore a common bolt head is in a straight-line or cross structure. However, the bolt head structure cannot meet the fastening requirement of large pretightening force (more than 12000Nm) in both theory and fastening process.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a fastening bolt structure suitable for large pretightening force, which can realize the fastening of the large pretightening force on a pole shoe plate of a motor rotor.

One technical scheme for achieving the purpose is a fastening bolt structure suitable for large pretightening force, which comprises a bolt head and a tool spanner head;

four clamping teeth are uniformly arranged on the bolt head, the bottom edge of each clamping tooth is a 22.5-degree arc, and the side edge of each clamping tooth is of a linear structure;

the end part of the tool wrench head is provided with a clamping protrusion matched with the clamping teeth.

Furthermore, the fit clearance between the clamping protrusion and the clamping tooth is less than 0.5 mm.

According to the fastening bolt structure suitable for the large pre-tightening force, the four-claw bolt head structure is adopted, so that the stress bearing capacity of the four-claw bolt head structure is remarkably increased compared with that of the root area of other types of eight-claw bolt head structures, the reliability of the bolt is improved, and the fastening condition of the large pre-tightening force is provided. And after detection, selecting a square drive hydraulic torque wrench, applying 12000 N.m to fasten, then unscrewing, and carrying out magnetic powder inspection on the fastened four-claw bolt head and the tool fastening wrench head, wherein the magnetic powder inspection report shows that recordable defects are not found in both the four-claw bolt head and the tool fastening wrench head.

Drawings

FIG. 1 is a top view of a bolt head of a fastening bolt structure of the present invention, which is suitable for high pre-tightening force;

FIG. 2 is an oblique view of a bolt of the present invention adapted for a high pretension tightening bolt configuration;

fig. 3 is an oblique view of a tool head of a fastening bolt structure suitable for large pretightening force according to the present invention.

Detailed Description

In order to better understand the technical solution of the present invention, the following detailed description is made by specific examples:

referring to fig. 1 to 3, a fastening bolt structure suitable for large pre-tightening force includes a bolt head 1 and a tool wrench head 2.

Four clamping teeth 11 are uniformly arranged on the bolt head 1, the bottom edge of each clamping tooth is a 22.5-degree circular arc, and the side edge of each clamping tooth is of a linear structure. For the bolt head 1 with the radius of 45mm, the radius of the arc of the clamping tooth is 18mm, and the width of the card contact is 32.5 mm. The material of the bolt head is high-strength alloy material 40Cr2MoV, and the performance of the forging piece meets the material standard.

The end of the tool wrench head 2 is provided with a clamping protrusion 21 matched with the clamping teeth. The fit clearance between the clamping protrusion and the clamping tooth is less than 0.5 mm.

It should be understood by those skilled in the art that the above embodiments are only for illustrating the present invention and are not to be used as a limitation of the present invention, and that changes and modifications to the above described embodiments are within the scope of the claims of the present invention as long as they are within the spirit and scope of the present invention.