CN204851925U - Tension control is high strength bolt for structure - Google Patents

Abstract

The utility model relates to a tension control is high strength bolt for structure, including screw rod and the screw thread of setting at the screw rod both ends, the screw thread has following specification: when screw thread big footpath was 30mm, the pitch of screw thread was 4.0mm, and the tooth form angle is 50, and the high 2.0mm that be of screw thread, lead angle be 2 36 /, the root of thread fillet radius is 0.6mm, and the crest fillet radius is 0.4mm, and the screw thread finishes up transition zone length and is 24mm, wherein, screw thread final phase of a project transition zone indicates to set up the transition zone in transition department of screw thread and screw rod, progressively carries out the transition to the screw thread path by pitch diameter on the transition zone. Through the settlement to fillet radius, tooth form angle, thread depth equidimension at the bottom of this bolt screw thread core diameter, the ditch, it has the technological requirement that has satisfied thread processing to have satisfied the bolt strength requirement to transition department at screw thread and screw rod sets up the transition zone, makes this bolt have higher intensity and can not the breaking occur under the stretching force condition.

Description

A kind of tension control structure high-strength bolt

Technical field

The utility model relates to a kind of high-strength bolt, and this bolt is applicable to the prestress anchoraging on wind-power generating tower basis, the stretch-draw of bridge, the stretch-draw of large-scale steel structure truss, the anchoring etc. of rock bank protection.

Background technique

the high-strength bolt of wind-power generating tower basis, bridge, large-scale steel structure truss according to requirements and structural requirement, the diameter large (Mt30 ~ Mt64) of high-strength bolt, the body of rod long (3m ~ 12m).Traditional bolt processing technic featuring and existing bolt standard can not meet the requirement of production technology, in order to meet the requirement of structure to the mechanical property of bolt, fracture toughness, fatigue behaviour, relaxation property, boost productivity, reduce cost of production, on the basis of existing bolt standard, with reference to ASTM standard design at the bottom of high, the tooth of the thread form angle of the high-strength bolt of wind-power generating tower basis, bridge, large-scale steel structure truss, pitch, tooth and the parameter such as radius of rounded crest.

this bolt called after tension control structure high-strength bolt, the sublimate making tension control structure high-strength bolt alloy material requires higher, the very long surface that is not easy to of the body of rod due to bolt goes pin to process (not peeling), therefore require very high, it is desirable that the bar of the good free of surface defects of dimensional accuracy to the smelting casting of steel, rolling technique.

because the body of rod of bolt is very long, if the amount of deformation carrying out quenching with Subsequent tempering so bolt to bolt by traditional heat treatment process is very large, particularly the tortuosity of bolt cannot ensure at all, and the intensity of whole support bolt is inconsistent, so adopt induction heating rapid thermal treatment tempering product line to realize the mechanical property requirements of bolt, within the scope of overall length, tortuosity can be controlled within 6 ‰.

the processing of screw thread adopts cold rolling forming technique, the fatigue life impact of surface roughness on bolt of screw thread is very large, rolled thread can improve the degree of finish of thread surface, the particularly degree of finish on screw thread dental groove surface, thus the raising of bolt fatigue strength is conducive to, rolled thread can produce working hardening layer and higher residual compressive stress, cuts much ice to stoping the germinating of fatigue crack and early stage expansion.

Model utility content

the purpose of this utility model is to provide a kind of tension control structure high-strength bolt, and this bolt, by the screw thread specification of particular design, material and processing method, makes this bolt have higher-strength and can not rupture under stretching force condition.

for solving the problems of the technologies described above, the technical solution of the utility model is as follows:

a kind of tension control structure high-strength bolt, comprise screw rod and the screw thread being arranged on screw rod two ends, described screw thread has following specification:

when Major Diam is 30mm, the pitch of screw thread is 4.0mm, and thread form angle is 50 °, and screw thread height is 2.0mm, and lead angle is 2 ° 36 ', and fillet radius at the bottom of tooth is 0.6mm, and crest radius is 0.4mm, and screw-thread ending transition zone length is 24mm;

when Major Diam is 36mm, the pitch of screw thread is 4.5mm, and thread form angle is 50 °, and screw thread height is 2.2mm, and lead angle is 2 ° 24 ', and fillet radius at the bottom of tooth is 0.8mm, and crest radius is 0.6mm, and screw-thread ending transition zone length is 27mm;

when Major Diam is 42mm, the pitch of screw thread is 5.0mm, and thread form angle is 50 °, and screw thread height is 2.4mm, and lead angle is 2 ° 16 ', and fillet radius at the bottom of tooth is 1.0mm, and crest radius is 0.8mm, and screw-thread ending transition zone length is 30mm;

when Major Diam is 48mm, the pitch of screw thread is 5.5mm, and thread form angle is 50 °, and screw thread height is 2.6mm, and lead angle is 2 ° 13 ', and fillet radius at the bottom of tooth is 1.2mm, and crest radius is 1.0mm, and screw-thread ending transition zone length is 33mm;

when Major Diam is 56mm, the pitch of screw thread is 6.0mm, and thread form angle is 50 °, and screw thread height is 2.8mm, and lead angle is 2 ° 03 ', and fillet radius at the bottom of tooth is 1.4mm, and crest radius is 1.2mm, and screw-thread ending transition zone length is 36mm;

when Major Diam is 64mm, the pitch of screw thread is 6.5mm, and thread form angle is 50 °, and screw thread height is 3.0mm, and lead angle is 1 ° 58 ', and fillet radius at the bottom of tooth is 1.6mm, and crest radius is 1.4mm, and screw-thread ending transition zone length is 39mm;

wherein, described screw-thread ending transition zone refers to and arranges transition zone at the transition position of screw thread and screw rod, and transition zone is progressively transitioned into diameter of thread by effective diameter of thread.

the outstanding mechanical property of tension control structure high-strength bolt described in the utility model will lean on following guarantee: the cold rolling technique of screw thread, the design of threads geometrical parameters, ensure that the requirement of strength of bolt and the moulding process requirement of cold rolling, the tooth form of design is similar to trapezoidal, crest width is 2.46 times of regular screw threads crest width, ensure that the integrity of worm tooth in the ball blast technique before anticorrosion.

the technique effect that the utility model has:

the development of tension control structure high-strength bolt and the use in wind power foundation make the excavated volume of basic earthwork reduce 25%, and quick and easy for installation, cost of labor reduces, and construction period shortens.

tension control structure high-strength bolt heating efficiency when induction heating fast heat treatment device carries out quenching with Subsequent tempering is powerful can realize being rapidly heated energy saving.Accurately can control heat treatment temperature, reduce energy loss.Reduce ambient heat loss and reduce energy consumption.In induction heating rapid thermal treatment process, do not produce waste gas, waste water and waste residue, can not to environment.Induction heating rapid thermal treatment and prior heat treatment process ratio, can save the energy of about 40%, thus decrease atmospheric CO2 emissions, is environmental type heat treatment process.

Accompanying drawing explanation

below in conjunction with accompanying drawing, the utility model is described further

fig. 1 is the structural representation of high-strength bolt described in the utility model;

fig. 2 is the partial enlarged drawing of part A in Fig. 1;

embodiment.

embodiment 1

as shown in Figure 1, a kind of tension control structure high-strength bolt, comprise screw rod and the screw thread being arranged on screw rod two ends, the specification of bolt has 6 kinds, and the Major Diam Mt of requirement is 30mm, 36mm, 42mm, 48mm, 56mm, 64mm respectively, and length is 3m ~ 12m.Intensity rank has two kinds namely 8.8 grades and 10.9 grades, is 4.0mm, 4.5mm, 5.0mm, 5.5mm, 6.0mm, 6.5mm respectively to the pitch of its design of the threaded bolt in two end part; Thread form angle 50 °, screw thread height is 2.0mm, 2.2mm, 2.4mm, 2.6mm, 2.8mm, 3.0mm respectively, and other geometric parameters of bolt are in table one.

wherein,

major Diam Mt refers to the diameter of the ideal cylinder tangent with outside thread crest;

pitch P refers to adjacent two teeth on screw thread at middle axial distance on the bus of cylndrical surface between corresponding 2;

thread form angle α refers in screw thread axial cross section, the angle of thread profile dual-side;

screw thread height h refers to the perpendicular distance of tip of thread and root of thread;

lead angle γ refers to the tangent line of helix on central diameter cylinder and the interplanar angle perpendicular to the axis of thread;

screw-thread ending transition zone refers to and arranges transition zone at the transition position of screw thread and screw rod, is progressively transitioned into diameter of thread by effective diameter of thread d.

specific to bolt connecting body, the screw thread ditch of mechanics factor bolt is the centrostigma of bolt stress under external force, root of thread diameter is more close to round steel diameter during rolling screw-threads, the bearing capacity of bolt is larger, also rolling screw-threads is beneficial to shaping, but thread depth affects not again the intensity of worm tooth, the basis of GB GB/T196-2003 regular screw threads base dimension increases the thread pitch 0.5mm of equivalent specifications, consider the process characteristic of rolling screw-threads processing, by to tooth form Strength co-mputation, to the Strength co-mputation of bolt minimum diameter (bottom of trench), scientific and reasonable test, accurate analog determination root of thread diameter, bottom of trench fillet radius, thread form angle, thread depth equidimension, the requirement of strength that should meet bolt meets the technological requirement of screw thread process again.

except screw thread ditch, the another weak part affecting the end bolt intensity particularly fatigue strength of bolt is the transition position in screw thread and bar portion, due to the sudden change in cross section, there is higher stress to concentrate, the for a change sudden change in cross section, screw-thread ending position devises the transition zone of about 20 ~ 40mm when designing, be progressively transitioned into diameter of thread, eliminate the abrupt change of cross-section by roll extrusion central diameter d, avoid the generation of stress concentration point, improve the working strength of bolt.Accompanying drawing one is seen at its shape and position

at the bottom of screw thread dental groove shape and tooth, the fatigue behaviour of fillet radius size to bolt also has a certain impact, when bolt bears stretching force, screw thread dental groove place will produce stress and concentrate, its value depends on the shape of dental groove to a great extent, the groove of bolt is more level and smooth, stress is concentrated less, and fatigue strength is higher.Design fillet radius size at the bottom of the corresponding tooth of the bolt design of different size during dental groove shape, make the groove of screw thread smooth-out, reduce stress and concentrate.

it will be recognized by those skilled in the art; under the prerequisite not departing from protection domain of the present utility model; various amendment, change and combination can be carried out to above-mentioned mode of execution, and think that this amendment, change and combination are within the scope of originality thought.

Claims (1)

1. a tension control structure high-strength bolt, comprise screw rod and the screw thread being arranged on screw rod two ends, it is characterized in that, described screw thread has following specification:

When Major Diam is 30mm, the pitch of screw thread is 4.0mm, and thread form angle is 50 °, and screw thread height is 2.0mm, and lead angle is 2 ° 36 ', and fillet radius at the bottom of tooth is 0.6mm, and crest radius is 0.4mm, and screw-thread ending transition zone length is 24mm;

When Major Diam is 36mm, the pitch of screw thread is 4.5mm, and thread form angle is 50 °, and screw thread height is 2.2mm, and lead angle is 2 ° 24 ', and fillet radius at the bottom of tooth is 0.8mm, and crest radius is 0.6mm, and screw-thread ending transition zone length is 27mm;

When Major Diam is 42mm, the pitch of screw thread is 5.0mm, and thread form angle is 50 °, and screw thread height is 2.4mm, and lead angle is 2 ° 16 ', and fillet radius at the bottom of tooth is 1.0mm, and crest radius is 0.8mm, and screw-thread ending transition zone length is 30mm;

When Major Diam is 48mm, the pitch of screw thread is 5.5mm, and thread form angle is 50 °, and screw thread height is 2.6mm, and lead angle is 2 ° 13 ', and fillet radius at the bottom of tooth is 1.2mm, and crest radius is 1.0mm, and screw-thread ending transition zone length is 33mm;

When Major Diam is 56mm, the pitch of screw thread is 6.0mm, and thread form angle is 50 °, and screw thread height is 2.8mm, and lead angle is 2 ° 03 ', and fillet radius at the bottom of tooth is 1.4mm, and crest radius is 1.2mm, and screw-thread ending transition zone length is 36mm;

When Major Diam is 64mm, the pitch of screw thread is 6.5mm, and thread form angle is 50 °, and screw thread height is 3.0mm, and lead angle is 1 ° 58 ', and fillet radius at the bottom of tooth is 1.6mm, and crest radius is 1.4mm, and screw-thread ending transition zone length is 39mm;

Wherein, described screw-thread ending transition zone refers to and arranges transition zone at the transition position of screw thread and screw rod, and transition zone is progressively transitioned into diameter of thread by effective diameter of thread.