CN201925305U

CN201925305U - Prestressed indicating bolt

Info

Publication number: CN201925305U
Application number: CN2011200519867U
Authority: CN
Inventors: 林尚波
Original assignee: Dude Machinery Technology (shanghai) Co ltd
Current assignee: Dude Machinery Technology (shanghai) Co ltd
Priority date: 2011-03-02
Filing date: 2011-03-02
Publication date: 2011-08-10
Anticipated expiration: 2021-03-02

Abstract

The utility model discloses a prestressed indicating bolt, which comprises a bolt, a guide rod, a liquid bag and a gland. The bolt is a hexagonal-head bolt or stud bolt, and one end of the bolt is provided with a threaded hole and a stepped hole axially. The guide rod is in the shape of a screw with a semicircular end coated with marking color. The liquid bag is a disc-shaped closed bag filled with colored liquid. The gland is a boss-type transparent unit. The guide rod is arranged in the threaded hole of the bolt, an external thread is meshed with the threaded hole, the gland is arranged in the stepped hole of the bolt, the liquid bag is arranged in the stepped hole of the bolt and between the gland and the guide rod, and two sides of the closed bag are respectively bonded with the gland and the semicircular end of the guide rod. Change of color of the liquid in the liquid bag can be observed by the aid of the gland, and stress state of the bolt is determined by means of comparison of color variation, so that internal stress of the bolt during operation is controlled accurately.

Description

Pretension stress indication bolt

Technical field

The utility model relates to the bolt of technical field of fastening, especially a kind of pretension stress indication bolt.

Background technique

At present, the method for control bolt pretightening, the overwhelming majority is to control the pretightening force that produces on the bolt indirectly by the moment of torsion controlling tool, such as adopting manual torque spanner, Pneumatic immpacting spanner, automatic torsion termination instrument etc.Because the fastening piece of bolt, nut class, in the process fastening by control torque, the torsion of considerable part all is used to overcome friction, and this frictional force is subjected to Placement, the influence of the geometrical shape of fastening piece, material, surface hardness, surface finishment, degree of lubrication and far from each other, so, identical torsional interaction is on bolt and the true pretension stress that produces is not quite similar, in real work, with the method for moment of torsion, accurately controlling bolt pretightening is to be difficult to realize; In addition, for the bolt that is in the stress working state for a long time, owing to the fatigue of material produces distortion, perhaps mechanical shock etc. causes bolt looseness, this because distortion or the loosening change that causes the bolt internal stress, and very difficult quilt is in time found; Again it, in the structure for the connection of bolt group, the conformity of each bolt pretightening will be directly connected to the uniformity that the mating face contact pressure distributes, and then influence the connection reliability and the global stability of structure, the conformity of control bolt group pretightening force also is the difficult point of structural member construction.The significance of control bolt pretightening is self-evident, and problem is how to find simply effective, practicable method.

The model utility content

The purpose of this utility model is a kind of pretension stress indication bolt that provides at the deficiencies in the prior art, the utility model is by observing change in color in the gland, stress phase when utilizing the compared colour difference to determine the bolt carrying, thereby the accurate control of realization working bolt pretightening force.

The concrete technological scheme that realizes the utility model purpose is:

A kind of pretension stress indication bolt, its characteristics comprise bolt, guide rod, liquid capsule and gland, described bolt is hexagon head bolt or stud bolt, the one end is axially arranged with tapped hole and step hole, guide rod is that screw-like, its body of rod are provided with outside thread, the termination is provided with cup head, is coated with underlined look on the cup head, and the liquid capsule is the sealing bag of disk shape, bag is the transparent body, is provided with colored liquid in it that gland is the round table-like transparent body; Described guide rod places in the tapped hole of bolt, and outside thread and tapped hole engagement, and gland is located in the step hole of bolt, and the liquid capsule is located in the bolt step hole and between gland and guide rod, the two sides of bag is pasted with the cup head of gland and guide rod respectively.

The utility model is observed change in color in the liquid capsule by gland, utilizes the compared colour difference to determine the stress phase of bolt carrying, thereby realizes the accurate control of working bolt internal stress.

Description of drawings

Fig. 1 is a structural representation of the present utility model;

Fig. 2 is the A place structure for amplifying schematic representation of Fig. 1;

Fig. 3 is another structural representation of the present utility model;

Fig. 4 is an another structural representation of the present utility model;

Fig. 5 is a user mode schematic representation of the present utility model.

Embodiment

Consult Fig. 1, Fig. 2, the utility model comprises bolt 1, guide rod 2, liquid capsule 3 and gland 4, described bolt 1 is hexagon head bolt or stud bolt, the one end is axially arranged with tapped hole 11 and step hole 12, guide rod 2 is for screw-like, its body of rod are provided with outside thread, the termination is provided with cup head 21, is coated with underlined look on the cup head 21, and liquid capsule 3 is the sealing bag of disk shape, bag is the transparent body, is provided with colored liquid in it that gland 4 is the round table-like transparent body; Described guide rod 2 places in the tapped hole 11 of bolt 1, and outside thread and tapped hole 11 engagements, gland 4 is located in the step hole 12 of bolt 1, and liquid capsule 3 is located in bolt 1 step hole 12 and between gland 4 and guide rod 2, the two sides of bag is pasted with the cup head of gland 4 and guide rod 2 respectively.

The utility model is to use like this:

Consult Fig. 1, Fig. 2, Fig. 5, installation of the present utility model, guide rod 2 is placed in the tapped hole 11 of bolt 1, and outside thread and tapped hole 11 engagements will be injected black liquor in liquid capsule 3 bags, and liquid capsule 3 is located in bolt 1 step hole 12, gland 4 is located in the step hole 12 of bolt 1, the one side of liquid capsule 3 bags is pasted with the cup head of guide rod 2, and the another side and the gland 4 of liquid capsule 3 bags are pasted, and the cup head that makes guide rod 2 is near gland 4; At last bolt 1 is penetrated structural member, the band upper cap nut is given bolt 1 application of force;

When not when bolt 1 applies axial pre tightening force, very close to each other between the cup head of guide rod 2 and the gland 4, black liquor in liquid capsule 3 bags is squeezed to periphery by the cup head of guide rod 2, at this moment, observes directly the mark look that scribbles on the cup head 21 by transparent gland 4, liquid capsule 3;

When bolt 1 applies certain axial pre tightening force, bolt 1 tension force deformation also produces axial strain, this strain is passed to guide rod 2, make guide rod 2 with respect to hexagon head generation displacement left, produce the gap between the cup head of guide rod 2 and the gland 4, black liquor in the liquid capsule 3 is permeated to the centre by periphery, at this moment, observes the mark look blackening gradually that scribbles on the cup head 21 by transparent gland 4, liquid capsule 3;

When continuing when bolt 1 applies axial pre tightening force, the strain value of bolt 1 tension force deformation increases, this strain is passed to guide rod 2, guide rod 2 is increased with respect to the displacement that hexagon head produces left, gap between the cup head of guide rod 2 and the gland 4 is further strengthened, black liquor in the liquid capsule 3 at this moment, is observed the mark look complete blackening that scribbles on the cup head 21 in the middle of being flowed to by periphery by transparent gland 4, liquid capsule 3.

Compare by marker color and the Standard colour board that changes, promptly determine the size of the pretightening force that bolt 1 is born by the strain value of bolt 1.

Consult Fig. 3, the utility model guide rod 2 places the structural representation of the screw rod end of bolt 1.

Consult Fig. 4, the utility model guide rod 2 places bolt 1 to be the structural representation of stud bolt.

Claims

1. a pretension stress is indicated bolt, it is characterized in that it comprises bolt (1), guide rod (2), liquid capsule (3) and gland (4), described bolt (1) is hexagon head bolt or stud bolt, the one end is axially arranged with tapped hole (11) and step hole (12), guide rod (2) is that screw-like, its body of rod are provided with outside thread, the termination is provided with cup head (21), cup head is coated with underlined look on (21), liquid capsule (3) is the sealing bag of disk shape, bag is the transparent body, is provided with colored liquid in it that gland (4) is the round table-like transparent body; Described guide rod (2) places in the tapped hole (11) of bolt (1), and outside thread and tapped hole (11) engagement, gland (4) is located in the step hole (12) of bolt (1), liquid capsule (3) is located in bolt (1) step hole (12) and is positioned between gland (4) and the guide rod (2), and the two sides of bag is pasted with the cup head of gland (4) and guide rod (2) respectively.