CN202203249U

CN202203249U - Bolt

Info

Publication number: CN202203249U
Application number: CN2011202889479U
Authority: CN
Inventors: 燕存露
Original assignee: Autocraft Industrial (Shanghai) Ltd
Current assignee: SHANGHAI AUTOCRAFT CO., LTD.
Priority date: 2011-08-10
Filing date: 2011-08-10
Publication date: 2012-04-25
Anticipated expiration: 2021-08-10

Abstract

The utility model discloses a bolt, which comprises a nut and screw. The peripheral surface of the screw is provided with threads matched with the nut, the tail ends of the threads are provided with teeth meshed with the nut, and the cross sections of the teeth are arc. The teeth with the arc structures can remarkably improve combination strength of an assembly structure after thread connection between the screw and the nut and enable mechanical stresses including pulling stress, shearing force and the like at the positions of the teeth to be distributed more evenly during use so as to correspondingly improve the whole anti-pulling strength of the bolt and correspondingly prolong whole fatigue service life of the bolt.

Description

A kind of bolt

Technical field

The utility model relates to the machanical fastener technical field, particularly a kind of bolt.

Background technique

Bolt is widely used in the every aspect of machine building industry and mechanical industry as a kind of common fastening piece.And along with the improving constantly of working strength, people also have higher requirement for the usability of bolt.

Present existing bolt, its screw portion is processed with the screw thread that matches with nut, to satisfy the connection needs between bolts and nuts in the assembly process.After assembling was accomplished, nut and bolt be relative fixed and closely interlock at the ending place of the screw tip of this bolt.

Yet; Though existing bolt can satisfy basic fastening needs, because the ending place of its screw tip is merely common worm structure, tensile strength is relatively poor; In the using process after the fastening completion of bolts and nuts; Fatigue damage even fracture very easily appear in the ending place of screw tip, cause the whole usability of bolt relatively poor, and fatigue life is shorter.

Therefore, how to improve the tensile strength of bolt, and to prolong its fatigue life be the important technological problems that those skilled in the art need solve at present.

The model utility content

The purpose of the utility model provides a kind of bolt, and the tensile strength of this bolt is higher, and fatigue life is longer.

For solving the problems of the technologies described above, the utility model provides a kind of bolt, comprises nut and screw rod, has the screw thread that matches with nut on the outer circumferential face of said screw rod; The end of said screw thread has and nut age of a draught animal of interlock mutually, and the cross section of the said age of a draught animal is a circular arc.

Preferably, said nut has the under head fillet that matches with joint outer part with the junction of said screw rod.

Preferably, the radius of said under head fillet is got its maximum value.

Preferably, have annular knurl on the outer circumferential face of said nut, and said annular knurl protrudes from the outer circumferential face of said nut.

Preferably, the bearing of trend of the axis of the bearing of trend of said annular knurl and said nut is consistent.

Preferably, said bolt is specially hexagon socket head cap screw.

Above-mentioned background is technological relatively, and the bolt that the utility model provided comprises nut and screw rod, has the screw thread that matches with nut on the outer circumferential face of said screw rod; The end of said screw thread has and nut age of a draught animal of interlock mutually, and the cross section of the said age of a draught animal is a circular arc.The age of a draught animal with this kind arc-shaped structure; Can significantly improve the adhesive strength of the back assembly structure that is threaded between the said bolts and nuts; And make in the using process; Mechanical stress more even distribution such as the tensile stress that said age of a draught animal place receives, shearing force, thus the corresponding raising of whole tensile strength of said bolt made, and make the integral fatigue life of said bolt be able to corresponding prolongation.

In another preferred version of the utility model, said nut has the under head fillet that matches with joint outer part with the junction of said screw rod.Adhesive strength between the bolt with this under head fillet structure, itself and joint outer part is higher, and the mechanical stress of assembling after accomplishing be evenly distributed, and said bolt is difficult for producing fracture and distortion, is able to further raising its fatigue life thereby make.

Description of drawings

In order to be illustrated more clearly in the utility model embodiment or technological scheme of the prior art; To do to introduce simply to the accompanying drawing of required use in embodiment or the description of the Prior Art below; Obviously, the accompanying drawing in describing below only is some embodiments of the utility model, for those of ordinary skills; Under the prerequisite of not paying creative work, can also obtain other accompanying drawing according to these accompanying drawings.

The broken section structural representation of the bolt that Fig. 1 is provided for a kind of embodiment of the utility model;

Fig. 2 is the structure enlarged view of A part among Fig. 1;

Fig. 3 is the structure enlarged view of B part among Fig. 1.

Embodiment

The core of the utility model provides a kind of bolt, and the tensile strength of this bolt is higher, and fatigue life is longer.

In order to make those skilled in the art person understand the utility model scheme better, the utility model is done further to specify below in conjunction with accompanying drawing and embodiment.

Please refer to Fig. 1, Fig. 2 and Fig. 3, the broken section structural representation of the bolt that Fig. 1 is provided for a kind of embodiment of the utility model; Fig. 2 is the structure enlarged view of A part among Fig. 1; Fig. 3 is the structure enlarged view of B part among Fig. 1.

In embodiment, the bolt that the utility model provided comprises nut 11 and screw rod 12, has the screw thread 13 that matches with nut on the outer circumferential face of screw rod 12; The end of screw thread 13 has and nut age of a draught animal 131 of interlock mutually, and the cross section of the age of a draught animal 131 is a circular arc.The age of a draught animal 131 with this kind arc-shaped structure; Can significantly improve the adhesive strength of the back assembly structure that is threaded between the said bolts and nuts; And make in the using process; Mechanical stress more even distribution such as the tensile stress that the ages of a draught animal 131 place receives, shearing force, thus the corresponding raising of whole tensile strength of said bolt made, and make the integral fatigue life of said bolt be able to corresponding prolongation.

Further, nut 11 has the under head fillet 121 that matches with joint outer part with the junction of screw rod 12.Adhesive strength between the bolt with these under head fillet 121 structures, itself and joint outer part is higher, and the mechanical stress of assembling after accomplishing be evenly distributed, and said bolt is difficult for producing fracture and distortion, is able to further raising its fatigue life thereby make.

Particularly, the radius of under head fillet 121 is got its maximum value.Under head fillet 121 with this kind maximum radius structure can further improve the structural strength of the junction of 12 of nut 11 and screw rods, thereby the tensile strength of the said bolt after making assembling accomplish is able to corresponding raising, and its fatigue life of corresponding prolongation.

On the other hand, have annular knurl 111 on the outer circumferential face of nut 11, and annular knurl 111 protrudes from the outer circumferential face of nut 11.This annular knurl 111 can enlarge markedly the frictional force of nut 11 outer circumferential faces, so that the user is to the dismounting and the assembling of said bolt.

More specifically, the bearing of trend of the axis of the bearing of trend of annular knurl 111 and nut 11 is consistent.Annular knurl 111 with this kind arrangement mode can make the dismounting of said bolt and assembly process more convenient.

In addition, said bolt is specially hexagon socket head cap screw.Certainly, said bolt is not limited to the hexagon socket head cap screw shown in the figure, all can so long as can satisfy actual use needs.

Can know that to sum up the bolt that provides in the utility model comprises nut and screw rod, have the screw thread that matches with nut on the outer circumferential face of said screw rod; The end of said screw thread has and nut age of a draught animal of interlock mutually, and the cross section of the said age of a draught animal is a circular arc.The age of a draught animal with this kind arc-shaped structure; Can significantly improve the adhesive strength of the back assembly structure that is threaded between the said bolts and nuts; And make in the using process; Mechanical stress more even distribution such as the tensile stress that said age of a draught animal place receives, shearing force, thus the corresponding raising of whole tensile strength of said bolt made, and make the integral fatigue life of said bolt be able to corresponding prolongation.

More than the bolt that the utility model provided has been carried out detailed introduction.Used concrete example among this paper the principle and the mode of execution of the utility model are set forth, above embodiment's explanation just is used to help to understand the method and the core concept thereof of the utility model.Should be understood that; For those skilled in the art; Under the prerequisite that does not break away from the utility model principle, can also carry out some improvement and modification to the utility model, these improvement and modification also fall in the protection domain of the utility model claim.

Claims

1. a bolt comprises nut and screw rod, has the screw thread that matches with nut on the outer circumferential face of said screw rod; It is characterized in that: the end of said screw thread has and nut age of a draught animal of interlock mutually, and the cross section of the said age of a draught animal is a circular arc.

2. bolt as claimed in claim 1 is characterized in that: said nut has the under head fillet that matches with joint outer part with the junction of said screw rod.

3. bolt as claimed in claim 2 is characterized in that: the radius of said under head fillet is got its maximum value.

4. like each described bolt in the claim 1 to 3, it is characterized in that: have annular knurl on the outer circumferential face of said nut, and said annular knurl protrudes from the outer circumferential face of said nut.

5. bolt as claimed in claim 4 is characterized in that: the bearing of trend of the bearing of trend of said annular knurl and the axis of said nut is consistent.

6. bolt as claimed in claim 5 is characterized in that: said bolt is specially hexagon socket head cap screw.