CN211728955U

CN211728955U - Sleeve for preventing fatigue damage of hexagonal head of bolt

Info

Publication number: CN211728955U
Application number: CN201922254281.4U
Authority: CN
Inventors: 李华栋; 谢文恺; 张振平; 严军辉; 徐峰
Original assignee: Avic Shaanxi Dongfang Aviation Instrument Co ltd
Current assignee: Avic Shaanxi Dongfang Aviation Instrument Co ltd
Priority date: 2019-12-16
Filing date: 2019-12-16
Publication date: 2020-10-23
Anticipated expiration: 2029-12-16

Abstract

The utility model discloses a prevent sleeve that six square heads of bolt tired decreases, including bolted connection portion and spanner head switching portion, there are six working planes of screwing up that are on a parallel with sleeve axis and adjacent plane contained angle be 120 in bolted connection portion's the inner chamber, the inner chamber of switching portion and the square tenon adaptation of spanner head, there is convex recess interval between six working planes of screwing up in the bolted connection portion inner chamber. When the hexagonal bolt is used, the stress part of the bolt is arranged in the middle of each side face of the hexagonal head, and the six longitudinal edges of the hexagonal head are arranged in the grooves in the corresponding positions, so that the phenomenon that the six edges bear torque and are extruded to cause fatigue damage is avoided.

Description

Sleeve for preventing fatigue damage of hexagonal head of bolt

Technical Field

The utility model belongs to the technical field of mechanical assembly tool, what relate to is a match in the sleeve of box spanner tightening bolt.

Background

The sleeve technology and the product which can realize the screwing of the hexagon bolt are applied to a plurality of applications, and according to the national standard, a gap of 0.3-0.5 mm exists between the sleeve and the external dimension of the hexagon head of the hexagon bolt with the same specification. This clearance is originally as the clearance that sleeve and hex bolts cup jointed, but at the bolt tightening in-process, six working faces in the sleeve die cavity can not laminate completely with six sides of hex bolts hexagonal respectively, and only six edges of six hexagonal heads of bolt are separately with telescopic corresponding working face contact atress, just so lead to the six edges of hex bolts to tired the loss easily, will appear sleeve "skidding" phenomenon during the serious, can't accomplish the dismouting work of bolt. On the other hand, six 60-degree edges exist in the sleeve, the six edges cannot be machined on a common machine tool, special equipment such as wire cutting equipment is needed, machining efficiency is low, and product cost is high.

Disclosure of Invention

The utility model aims to overcome current sleeve and cause the defect that six square heads of bolt are tired to decrease easily, provide a can effectively prevent the sleeve that six square heads of bolt are tired to decrease.

The technical scheme for realizing the purpose is as follows: the utility model provides a prevent sleeve that six square heads of bolt tired decrease, includes bolted connection portion and spanner head switching portion, has six working planes of screwing up that be on a parallel with sleeve axis and adjacent plane contained angle be 120 in bolted connection portion's the inner chamber, the inner chamber of switching portion and the square tenon adaptation of spanner head, its characterized in that, there is the interval between six working planes of screwing up in the bolted connection portion inner chamber, the interval is a convex recess that is on a parallel with the sleeve axis.

Further, in the inner cavity of the bolt connecting part, the distance between the bottoms of two circular arc grooves on a diagonal is 1.2 times that between the hexagonal head of the bolt to be screwed and the vertex of the diagonal.

Further, in the inner cavity of the connecting part, the length of each tightening working plane is 0.3 times of the length of one side of the hexagonal head of the tightened hexagonal bolt.

The utility model has the advantages that: when using the utility model discloses during the tightening bolt, the atress position of bolt is at the middle part of every side of hexagonal head, and six vertical arriss of hexagonal head are but in the recess that corresponds the position, and the ability that every side middle part of bolt hexagonal head can bear the weight of the moment of torsion is far greater than six edges to avoided six edges to bear the weight of the moment of torsion extrusion and tired phenomenon of losing takes place. Additionally, the utility model discloses when processing the preparation, select suitable vertical milling cutter to carry out milling process to six recesses earlier, then just can process out six working planes on ordinary lathe, reduced manufacturing cost naturally.

Drawings

Fig. 1 is a cross-sectional view of an embodiment of the present invention along an axis.

Fig. 2 is a left side view of the embodiment shown in fig. 1.

Fig. 3 is a schematic view of the socket state of the hexagonal nut of the present invention.

Fig. 4 is a schematic view of the state of the hexagonal nut of the present invention when it is tightened.

In the figure: 1. bolt connection portion, 2, spanner head switching portion, 3A, 3B, 3C, 3D, 3E, 3F, recess, 4A, 4B, 4C, 4D, 4E, 4F, screw up working plane, 5, hexagonal head, H, interval, L, length, H, interval, M, length.

Detailed Description

The present invention will be further explained with reference to the accompanying drawings.

As shown in fig. 1 and 2, the utility model discloses a bolted connection portion 1 and wrench end switching portion 2 have in bolted connection portion 1's the inner chamber to be on a parallel with sleeve axis and adjacent plane contained angle be 120 six working planes of screwing up, the square tenon adaptation of switching portion 2's inner chamber and wrench end, the technical characterized in that, six working planes of screwing up 4A, 4B, 4C, 4D, 4E and 4F in bolted connection portion 1 inner chamber are each discontinuous, have the interval between two working planes each other, and this interval is the convex recess that is on a parallel with the sleeve axis, recess 3A, 3B, 3C, 3D, 3E and 3F promptly.

As shown in fig. 2 and 3, in the present embodiment, in the inner cavity of the bolt connecting portion 1, the groove bottom spacing H (shown in fig. 2) of two diagonal grooves, that is, two grooves farthest away, for example, the groove 3C and the groove 3F, is 1.2 times the hexagonal-to-diagonal vertex spacing H (shown in fig. 3) of the bolt to be tightened; the length L (shown in fig. 2) of each tightening work plane, for example, the tightening work plane 4F is 0.3 times the length M (shown in fig. 3) of the hexagonal head 5 to be tightened.

As shown in fig. 3 and 4, the

tightening surfaces

4A, 4B, 4C, 4D, 4E, and 4F form a regular hexagonal cavity corresponding to the outer dimensions of the hexagonal head of the hexagonal bolt of the same specification, and the

grooves

3A, 3B, 3C, 3D, 3E, and 3F form the free rotation allowance positions of the six longitudinal edges of the hexagonal head of the hexagonal bolt.

As shown in fig. 4, when the bolt is tightened according to the present invention, the

tightening surfaces

4A, 4B, 4C, 4D, 4E and 4F respectively abut against the middle portion of each side of the hexagonal head 5, that is, the force receiving portion of the bolt is the middle portion of each side of the hexagonal head 5, and the six longitudinal edges of the hexagonal head 5 are in the grooves corresponding to the positions. Because the torque bearing capacity of the middle part of each side surface of the six square heads 5 is far larger than that of the six edges, the phenomenon that the six edges bear torque and are stressed and damaged due to extrusion is avoided.

Claims

1. The utility model provides a prevent that six square heads of bolt are tired sleeve that decreases, includes bolted connection portion and spanner head switching portion, has in bolted connection portion's the inner chamber to be on a parallel with sleeve axis and adjacent plane contained angle and be 120 six working plane of screwing up, the inner chamber of switching portion and the square tenon adaptation of spanner head, its characterized in that: six screwing working planes in the inner cavity of the bolt connecting part are provided with intervals, and each interval is an arc-shaped groove parallel to the axis of the sleeve.

2. The bushing for preventing hexagonal head fatigue damage of a bolt of claim 1, wherein: in the inner cavity of the bolt connecting part, the distance between the bottoms of two arc-shaped grooves on a diagonal is 1.2 times that between the hexagonal head of the screwed bolt and the vertex of the diagonal.

3. The bushing for preventing hexagonal head fatigue damage of a bolt of claim 1, wherein: in the inner cavity of the connecting part, the length of each tightening working plane is 0.3 time of the length of one side of the hexagonal head of the tightened hexagonal bolt.