CN112762077A

CN112762077A - Shear bolt

Info

Publication number: CN112762077A
Application number: CN202110096662.3A
Authority: CN
Inventors: 易书云; 易仕桂; 陆照俊; 周越华; 殷科
Original assignee: WUXI GUANGCAI MACHINERY MANUFACTURING CO LTD
Current assignee: WUXI GUANGCAI MACHINERY MANUFACTURING CO LTD
Priority date: 2021-01-25
Filing date: 2021-01-25
Publication date: 2021-05-07

Abstract

The invention discloses a shear-resisting bolt, comprising a screw rod and a bolt head. The screw rod is divided into a blade section, an extruded thread section, a screw expansion fitting section and a blade section in turn from the end far away from the bolt head and along the length direction of the screw rod. It is tapered and formed with a cutting edge; the thread expansion and tightening section is cylindrical, and the surface is provided with an external thread that matches the screw hole; the surface of the extruded thread section is a conical surface, which is provided with a thread bottom that matches the external thread. The extruded thread with the same diameter and the same pitch, and the outer diameter of the extruded thread gradually narrows from the thread expansion and tightening section to the blade section, and the outer diameter gradually decreases. The above shear bolts make the bolts in the process of screwing, first cut off the misaligned parts between the holes to form two concentric holes, and then extrude and expand the hole wall to form threads through the action of the extruding thread segment, so that the bolts are assembled with the holes. There is no gap and there is a certain expansion force between them, which improves the matching effect of the two and provides a new design idea for the bolt connection method.

Description

Shear bolt

Technical Field

The invention relates to a connecting piece for a building, in particular to a shear bolt.

Background

In building construction, two parts are often required to be connected, at the moment, holes are formed in the two parts, and the two parts are fastened through bolts to realize connection. However, in practice it has been found that on the one hand, there may be deviations in the apertures in the two parts, as shown in fig. 8; on the other hand, there may be a deviation in the concentricity of the holes on the two parts, as shown in FIG. 9. Above-mentioned two kinds of circumstances, under the general condition, general aperture will be greater than the bolt and just can realize the assembly, and if bolt and hole were gapped, the effect that shears can greatly reduced and the atress is uneven, cause each to break easily, lead to the bolt to twist into the difficulty or have the drunkenness clearance between bolt and the screw, appear connecting not hard up condition, influence the assembly effect, and lead to bearing very big shearing force on local position or the direction on the bolt, influence bolt life, can't satisfy the connection requirement.

Disclosure of Invention

The invention aims to provide a shear bolt, which optimizes the structure of the existing connecting bolt, improves the assembly effect and the shear resistance and meets the connecting requirement.

In order to achieve the purpose, the invention adopts the following technical scheme:

a shear bolt comprises a screw rod and a bolt head, wherein the screw rod is sequentially divided into a blade section, a thread extruding section and a thread expansion matching section along the length direction of the screw rod from the end part far away from the bolt head, and the blade section is in a conical tip shape and is formed with a cutting blade; the thread expansion fit section is cylindrical, and the surface of the thread expansion fit section is provided with an external thread matched with the screw hole; the surface of the thread extruding section is a conical surface, the thread extruding section is provided with extruding threads which are consistent with the thread bottom diameter and the thread pitch of the external threads, and the thread groove width of the extruding threads is gradually narrowed from the thread expansion matching section to the cutting edge section and the external diameter is gradually reduced.

Particularly, a guide section is connected between the blade section and the thread extruding section, and the guide section is a smooth cylindrical surface.

Particularly, the taper angle of the conical surface of the thread extruding section is 2-8 degrees.

In particular, the profile angles of the external thread and the extruded thread are both 60 °.

In particular, a thread-free section is left between the thread expansion fit section and the bolt head.

Compared with the prior art, the shear bolt has the advantages that the shear bolt optimally designs the structure of a common screw to form a blade section, a guide section, a thread extruding section and the like, so that in the screwing process of the bolt, the unaligned parts between holes are firstly cut off to form two concentric holes with good position degree and consistent size, and then the hole wall is extruded and expanded to form threads under the action of the thread extruding section, so that the bolt and the holes are in gapless fit after being assembled and have certain expansion force between the bolt and the holes, the matching effect of the bolt and the hole is improved, all the assembling bolts can bear more uniform and larger shearing force, and a new design thought is provided for a bolt connecting mode.

Drawings

Fig. 1 is a schematic structural view of a shear bolt provided in an embodiment of the present invention;

fig. 2 to 3 are schematic views illustrating the screwing of the shear bolt provided in the embodiment of the present invention;

FIGS. 4-5 are schematic views illustrating the assembly of shear bolts provided in accordance with embodiments of the present invention;

FIG. 6 is another structural schematic view of a shear bolt provided in an embodiment of the present invention;

FIG. 7 is an end view of FIG. 6;

fig. 8-9 are schematic views showing two cases where there is a deviation in the fitting holes of the two members.

Detailed Description

The technical scheme of the invention is further explained by the specific implementation mode in combination with the attached drawings.

Referring to fig. 1, the shear bolt according to the present embodiment includes a screw rod and a bolt head 1, wherein the screw rod is sequentially divided into a blade section 2, a guide section 3, a thread extruding section 4, and a thread expansion fitting section 5 along a length direction of the screw rod from an end portion far away from the bolt head 1.

The blade section 2 is in a conical tip shape and is formed with a cutting edge, the cutting edge can cut off the eccentric bulge in the bolt feeding process, the shadow part shown in figures 2 and 3 is the bulge to be cut, and the size requirement of the assembly hole is met and the position degree is improved.

The guide section 3 is a smooth cylindrical surface and is used for positioning and guiding bolt feeding.

The surface of the thread extruding section 4 is a conical surface, and the slope delta of the conical surface is preferably 2-8 degrees. The thread extruding section 4 is provided with an extruding thread 6 which is consistent with the thread bottom diameter d of the external thread 7 and the thread pitch, and the thread groove width of the extruding thread 6 is gradually narrowed from the thread expansion matching section 5 to the cutting edge section 2 and the external diameter is gradually reduced. Along with the deepening of the thread extruding section 4, internal threads can be formed on the inner wall of the cut assembly hole, and a screw hole with higher matching degree and certain expansion force is formed.

The thread expansion matching section 5 is cylindrical, the surface of the thread expansion matching section is provided with an external thread 7 matched with a screw hole formed by extruding and expanding, and the tooth form angles of the external thread 7 and the extruding thread 6 are both 60 degrees. The assembly thus performed, as shown in fig. 4 and 5, can significantly improve the assembly problems caused by the difference or decentration of the apertures.

A small unthreaded section 8 is also left between the thread expansion fit section 5 and the bolt head 1.

As shown in fig. 6 and 7, on the basis of the above, a structure of the shear bolt is provided, wherein the bolt head is small and square, and is suitable for special installation occasions.

In conclusion, the shear bolt optimally designs the structure of a common screw to form a blade section, a guide section, a thread extrusion section and the like, so that the bolt firstly cuts off the unaligned parts between holes in the screwing-in process to form two concentric holes with good position degree and consistent size, and then extrudes and expands the hole wall to form threads under the action of the thread extrusion section, thereby ensuring that the bolt is in gapless fit with the assembled holes and has certain expansion force between the bolt and the assembled holes, improving the matching effect of the bolt and the assembled holes, ensuring that all the assembled bolts can simultaneously bear more uniform and larger shearing force, and providing a new design idea for the bolt connection mode.

The foregoing embodiments are merely illustrative of the principles and features of this invention, which is not limited to the above-described embodiments, but is capable of various modifications and changes without departing from the spirit and scope of the invention, which are intended to be within the scope of the appended claims. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. A shear bolt, characterized in that it comprises a screw rod and a bolt head, and the screw rod is divided into a blade segment, an extruded thread segment, and a thread expansion fit in turn from the end away from the bolt head and along the length direction of the screw rod. part,

The blade segment is in the shape of a conical tip and is formed with a cutting edge;

The thread expansion and tight fitting section is cylindrical, and the surface is provided with an external thread matched with the screw hole;

The surface of the extruding thread segment is a conical surface, and an extruding thread having the same bottom diameter and pitch as the thread of the external thread is arranged on it, and the width of the thread groove of the extruding thread extends from the thread expansion and tightening section to the cutting edge. The segment becomes narrower and the outer diameter becomes smaller.

2 . The shear bolt according to claim 1 , wherein a guide section is connected between the cutting edge section and the extruding thread section, and the guide section is a smooth cylindrical surface. 3 .

3 . The shear bolt according to claim 1 , wherein the taper slope of the extruded thread segment is 2° to 8°. 4 .

4 . The shear bolt according to claim 1 , wherein the profile angles of the external thread and the extruded thread are both 60°. 5 .

5 . The shear bolt according to claim 1 , wherein a non-threaded section is left between the threaded expansion fitting section and the bolt head. 6 .