CN104976210A - Double-bolt anti-loose method - Google Patents
Double-bolt anti-loose method Download PDFInfo
- Publication number
- CN104976210A CN104976210A CN201410152929.6A CN201410152929A CN104976210A CN 104976210 A CN104976210 A CN 104976210A CN 201410152929 A CN201410152929 A CN 201410152929A CN 104976210 A CN104976210 A CN 104976210A
- Authority
- CN
- China
- Prior art keywords
- bolt
- nut
- pretightening force
- clamping bolt
- clamping
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 52
- 230000008878 coupling Effects 0.000 claims description 76
- 238000010168 coupling process Methods 0.000 claims description 76
- 238000005859 coupling reaction Methods 0.000 claims description 76
- 238000007789 sealing Methods 0.000 claims description 17
- 230000014759 maintenance of location Effects 0.000 claims description 13
- 238000005553 drilling Methods 0.000 claims description 11
- 238000012545 processing Methods 0.000 claims description 11
- 238000003466 welding Methods 0.000 claims description 8
- 230000000694 effects Effects 0.000 abstract description 31
- 238000000205 computational method Methods 0.000 description 43
- 239000000463 material Substances 0.000 description 23
- 230000008569 process Effects 0.000 description 16
- 230000008859 change Effects 0.000 description 9
- 238000005516 engineering process Methods 0.000 description 9
- 230000001360 synchronised effect Effects 0.000 description 9
- 230000001276 controlling effect Effects 0.000 description 8
- 238000004519 manufacturing process Methods 0.000 description 7
- 238000005493 welding type Methods 0.000 description 7
- 102220305346 rs1555469504 Human genes 0.000 description 6
- 235000008331 Pinus X rigitaeda Nutrition 0.000 description 4
- 235000011613 Pinus brutia Nutrition 0.000 description 4
- 241000018646 Pinus brutia Species 0.000 description 4
- 238000004364 calculation method Methods 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 4
- 238000010008 shearing Methods 0.000 description 4
- 238000012360 testing method Methods 0.000 description 4
- 230000009471 action Effects 0.000 description 3
- 230000010354 integration Effects 0.000 description 3
- 238000010791 quenching Methods 0.000 description 3
- 230000000171 quenching effect Effects 0.000 description 3
- 125000004122 cyclic group Chemical group 0.000 description 2
- 230000007812 deficiency Effects 0.000 description 2
- 230000005489 elastic deformation Effects 0.000 description 2
- 230000005284 excitation Effects 0.000 description 2
- 230000003116 impacting effect Effects 0.000 description 2
- 238000007689 inspection Methods 0.000 description 2
- 230000007246 mechanism Effects 0.000 description 2
- 239000004033 plastic Substances 0.000 description 2
- 230000035939 shock Effects 0.000 description 2
- 229910000679 solder Inorganic materials 0.000 description 2
- 229920001169 thermoplastic Polymers 0.000 description 2
- 239000004416 thermosoftening plastic Substances 0.000 description 2
- 230000007306 turnover Effects 0.000 description 2
- 229910000975 Carbon steel Inorganic materials 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 230000033228 biological regulation Effects 0.000 description 1
- 239000010962 carbon steel Substances 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000002596 correlated effect Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 239000003814 drug Substances 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 238000011900 installation process Methods 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 238000004080 punching Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000003938 response to stress Effects 0.000 description 1
- 238000012163 sequencing technique Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 238000005303 weighing Methods 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
- F16B39/00—Locking of screws, bolts or nuts
- F16B39/02—Locking of screws, bolts or nuts in which the locking takes place after screwing down
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
- F16B39/00—Locking of screws, bolts or nuts
- F16B39/02—Locking of screws, bolts or nuts in which the locking takes place after screwing down
- F16B39/12—Locking of screws, bolts or nuts in which the locking takes place after screwing down by means of locknuts
- F16B39/16—Locking of screws, bolts or nuts in which the locking takes place after screwing down by means of locknuts in which the screw-thread of the locknut differs from that of the nut
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Connection Of Plates (AREA)
- Mutual Connection Of Rods And Tubes (AREA)
Abstract
The invention relates to a double-bolt anti-loose method. Screw holes or holes are machined in connecting parts, and a hole is formed in the center of a fastening bolt rod body; a locking bolt and a fastening bolt use external threads with different diameters and spiral directions; the locking bolt penetrates the central hole of the fastening bolt rod body, and the locking bolt and the fastening bolt are jointly connected with the screw holes or nuts or reverse-spiral nuts, so that the bolt anti-loose effect is achieved; and the bolt connection reliability is improved, standard parts can be adopted in part of bolt or nut, and the cost can be reduced.
Description
Technical field
This patent relates to a kind of two screw retention method, processing screw hole or drilling on coupling, lock bolt is different with the external thread diameter of clamping bolt and rotation direction is contrary, the center drilling of the clamping bolt body of rod, lock bolt is through the center hole of the clamping bolt body of rod, lock bolt and clamping bolt and screw or nut, " anti-turning nut " connect, and reach the effect of screw retention.
Background technique
Bolt looseness mechanism:
1, screw pair screws screw thread generation creep.According to the secondary lax creep test of connection, after fastening nuts, 24 hours inner bolt pretightening forces reduce close to 10%, and speed of losing thereafter slows down, and nut easily loosens.
2, supporting surface pressure fall into cause loosen.Because the supporting surface contact stress of bolt head or nut is large, the surface of coupling has thermoplastic cyclic pressure to fall into.If in use plastic deformation continues to occur (being called that supporting surface pressure falls into), bolt elongate amount (referring generally to elastic elongation amount) and pretightening force reduce, and nut easily loosens revolution.
3, radial force is the main cause of bolt connection loosening.Some scholars (particularly the G.Junker of former West Germany) apply radial excitation force respectively to Bolt Connection and axial exciting force has done a large amount of tests, result possible loosened by the Bolt Connection of responsive to axial force also may not loosen, but be certain to loosen when radial excitation force acquires a certain degree by the Bolt Connection of radial force effect.After Bolt Connection pretension, nut is in radial-expansion condition by under the effect of the nut radial expansion force produced in pretightening force, when extraneous radial force is imported into and is acquired a certain degree, the balance voluntarily of nut radial expansion force will be destroyed, impel nut radial-play, and then threaded engagement place is reduced or vanishing along the static friction coefficient of helix tangent direction, equivalent friction angle reduces or is zero, loosen moment of torsion close to zero or be negative value, nut will loosen revolution.
4, the impact in gap between internal thread and outside thread.Standard thread many employings single line regular screw threads, lead angle (1 ° 40 ' ~ 3 ° 30 ') is less than the equivalent friction angle (6.5 ° ~ 10.5 °) of screw pair, therefore connecting screw thread can self-locking conditions satisfied, under certain pretightening force effect, generally can not get loose.But screw pair is Spielpassung normally, for M30 × 2 fine thread: the effective diameter of thread of bolt is for 28.701mm, and the effective diameter of thread of nut is 28.701mm, and scyewed joint average gap values is 0.1315mm, maximal clearance value 0.244mm.Spielpassung is conducive to screw thread manufacture and installation, but affects anti-loosing effect.In addition; the microscopic detritus of thread surface and particulate can be mixed between inside and outside tooth gap; similar solid lubricant effect; under vibration, impact and alternate load effect; inevitably there is device for elimination of axial-and radial-play in scyewed joint pair, the surface friction drag between internal and external threads there will be instantaneous reduction and even disappears.This phenomenon repeatedly repeats, interaction effect, finally causes connection to get loose.
Now have following several by screw retention method:
1, double nut locking (pairs of anti-loose nut structure): after two nuts are tightened top, produce between them one additional to top power, larger nut radial expansion force is produced jointly to top power and pretightening force, and away from extraneous radial force, therefore nut not easily turns round, but it is noted that the top power competence exertion anti-loosing effect that must produce this and add between two nuts.
Pairs of anti-loose nut structure stressed comparatively suitable with P1=0.2P, P2=0.8P.Wherein P1 is the pulling force of screw rod to locking nut (nut on non-bearing surface is called locking nut), P2 is the pulling force of screw rod to tightening nut (nut on work supporting surface is called tightening nut), P is the given pretightening force of screw rod, so tightening nut should be thicker, locking nut should be thinner.
2, " inverse rotation direction double nut " (belonging to double nut): bolt is compounded on same section of thread section by left-handed and dextrorotation two kinds of helixes, and existing left-handed thread has right-handed thread again.Tightening nut and locking nut are the nuts of two kinds of different rotation directions, first by tightening nut pretension during use, then by locking nut pretension.When vibrating, impacting, tightening nut has the trend occurring to loosen, but moves back the tightening direction that direction is locking nut due to the pine of tightening nut, and tightening of locking nut prevents the pine of tightening nut to move back, and causes tightening nut to get loose.
3, " execute must jail " screw thread: the different conical surfaces being its core diameter of thread has one 30 ° of Spiralock nuts and standard nut, externally threaded crest is wedge people internal thread root of the tooth 30 ° of conical surfaces tightly, produce very large radial coupling mechanism force, make nut have the ability of very strong opposing transverse vibration, and this transverse vibration is the main cause causing thread looseness.
4, storing more elastic deformation energy realizes locking: (1) increases the length of bolt, elastic elongation amount after bolt loads is directly proportional to pretightening force and bolt length, be inversely proportional to the sectional area of bolt, the elastic elongation amount of bolt is larger, and anti-loosing effect better; (2) use Hydraulic stopping nut, utilize the pretightening force increasing Bolt Connection, make high-strength bolt axially resiliently deformable occur and keep extended state, nut compresses, to reach locking object by the internal stress relying on bolt resiliently deformable to produce.
Other also have spring washer, Tension Nut, self-locking nut, longitudinal grooved nut, it is locking to bond, punching point riveted joint etc.
When adopting plain nut, theory analysis and test prove, screw the number of turns more, the degree of load diatibution inequality is also more remarkable, and after 8th ~ 10 circles, screw thread is hardly by load.
The carbon steel material Young's modulus manufacturing bolt is generally 200 ~ 210 × 10
3mpa.
High-strength bolt refers to the higher bolt making the size of machinery or component and structure reduce or to simplify of intensity, tensile strength is generally at more than 700Mpa, steady quality, but the not easily through hardening in Quenching Treatment of the high-strength bolt of more than diameter 30mm, quality is unstable, should reduce working stress in use.Use during high-strength bolt and have following features:
1, coupling bears alternate load effect and produce vibration, surface of contact wants to obtain less bolt deformation rigidity, adopt the bolt of high-strength small as far as possible, as 10.9 grades and 8.8 grades (10.9 grades mean tensile strength 1000MPa, and yield strength σ s is 90% of tensile strength).
2, the reason causing alternating stress excessive is that pretightening force is less than normal, and residue pretightening force is large, and therefore bolt is loaded into the limit of elasticity of 90% by axial pre tightening force always.Or adopt the pretightening force of bolt to be less than 80% of the Materials Yield Limit of bolt, and get high value as far as possible.Yield limit is yield strength σ s, and the two meaning is identical.
3, in Bolt Connection, the material that bolt selects distortion larger, and connected compcnent selects the good material of rigidity, and the hook of bolt can be made so more flat, and the hook of connected compcnent is comparatively steep, the amplitude of stress diminishes.When the intensity of bolt is certain, the amplitude of power in bolt can be reduced, contribute to improving bolt life.
High strength exploitation must adopt larger pretightening force, and general pretightening force is 70% ~ 81.2% of this bolt material yield strength σ s.When transverse vibration anti-loosing effect tested by Britain SPS-peace cloth internal medicine transverse vibration testing machine, find when bolt axial pre tightening force is increased to 0.45 σ s by 0.25 σ s, anti-loosing effect improves 13.2 times.When pretightening force reaches 0.75 σ s, anti-loosing effect also will improve greatly.
The controlling method of bolt pretightening has:
1, pretightening force is controlled by screw-down torque.The torque value that shown by torque wrench controls the pretightening force of connected compcnent, simple to operate, directly perceived, and error is about ± and 25%.
2, by nut controlling angle pretightening force.Angle of swing when nut (or bolt) is tightened and bolt elongate amount and be tightened the roughly proportional relation of summation of part shake allowance, thus can adopt the method reaching predetermined pretightening force by regulation angle of swing.When tightening at first, first to determine torque limit, bolt (nut) is screwed to torque limit always, then turn over a predetermined angle.Measuring nut corner is the most simply zero line at quarter, measures nut corner by the side that turns of nut.The measuring accuracy of nut corner can be controlled in 10 ° ~ 15 °.In general, pretightening force error is greatly about ± 15%.
3, pretightening force is controlled by bolt elongate amount.Control pretightening force by the elongation of bolt and can obtain higher control accuracy, be widely used as the pretightening force controlling method of important events Bolted Flanged Connection.If measure correct, its pretightening force error is about ± and 5%.Bolt elongate amount calculated example:
For 8.8 grades of M30 × 2 scyewed joint, as entity diameter of bolt D=30mm, the effective tensile elongation L=65mm of screw rod, nut is tightened with 1450Nm moment, and during bolt pretightening P=269kN, the elongation Δ L of bolt is:
ΔL＝P×L/(E×S)＝P×L/[E×3.14×(D/2)
2]
＝269×10
3×65×10
-3/[210×10
9×3.14×(30×10
-3/2)
2]＝0.118mm
Wherein P-entity bolt pretightening, N
The effective tensile elongation of L-screw rod, m
(high-strength bolt gets 210 × 10 to the Young's modulus of E-bolt material
3mpa), N/m
2
S-bolt sectional area (i.e. the cross-section area of the bolt body of rod), m
2
The stress σ of bolt is: σ=P/S=269 × 10
3/ [3.14 × (30 × 10
-3/ 2)
2]=381Mpa
8.8 grade bolt yield strength σ s=800 × 0.8=640Mpa, σ/σ s=381/640=0.595 ≈ 0.6.
If the Young's modulus of bolt etc. remain unchanged, the effective tensile elongation or the stress that are bolt change, and elastic elongation amount can follow effective tensile elongation or stress direct proportional linear change (in the limit of elasticity of bolt material).
4, pretightening force is controlled by screw-down torque and nut angle relation.First impose certain moment to fastening piece, then make nut turn over several angle, check whether last moment and corner meet and should have relation, to avoid, pretension is not enough or pretension is excessive.This controlling method advantage is: utilize the information that screw-down torque and nut corner provide, can accurately control tools for bolts ' pretension process and pretightening force, and can find may to occur in installation process tighten deficiency or over-tightened phenomenon, this is used alone Torque Control or controlling angle all cannot realize.
5, adopt resistance strain gage to measure the method for stress, mainly contain dynamometry bolt and ring washer two kinds of metering systems.Dynamometry bolt directly replaces existing bolt, and can measure the sensor of bolt pretightening, can be as accurate as kilogram.Ring washer metering system is the pressure at ring washer sensor (weighing sensor) the indirect inspection nut place by increasing at bolt head, obtains the pretightening force of bolt.Strain gauge can be puted up at bolt without screw thread place in addition, use resistance strain gage to measure and control pulling force suffered by bolt, pretightening force error can be controlled in ± 1% within.
Plain bolt refers to the bolt that tensile strength is lower, and as 3.6 grades and 5.6 grades etc., its pretightening force is each variant by the impact of physical condition, now illustrates, finds out the high value of pretightening force as a reference:
3.6 grades of M16 bolt pretightenings are generally 20400N, and stress σ is:
σ＝P/S＝20.4×10
3/[3.14×(16×10
-3/2)
2]＝101.5Mpa
3.6 grade bolt yield strength σ s=300 × 0.6=180Mpa, σ/σ s=101.5/180=0.564 ≈ 0.56.
3.6 grades of M30 bolt pretightenings are generally 73500N, and stress σ is:
σ＝P/S＝73.5×10
3/[3.14×(30×10
-3/2)
2]＝104.0Mpa
σ/σs＝104.0/180＝0.578≈0.58
5.6 grades of M16 bolt pretightenings are generally 34000N, and stress σ is:
σ＝P/S＝34×10
3/[3.14×(16×10
-3/2)
2]＝169.2Mpa
5.6 grade bolt yield strength σ s=500 × 0.6=300Mpa, σ/σ s=169.2/300=0.564 ≈ 0.56.
5.6 grades of M30 bolt pretightenings are generally 122000N, and stress σ is:
σ＝P/S＝122×10
3/[3.14×(30×10
-3/2)
2]＝172.7Mpa
σ/σs＝172.7/300＝0.576≈0.58
So the normal pretightening force of plain bolt or pre-tight stress are generally no more than 0.58 σ s (calculating for this specification).
When the pretightening force of plain bolt reaches 0.78 σ s, the externally threaded bottom of trench of bolt starts to destroy, therefore can using the reference value of 0.78 σ s as maximum pretightening force or maximum pre-tight stress.
Bolt Connection is under impact loading, and the stress response of bolt changes along with the change of pretightening force, and the pre-tight stress of receive shearing bolt is about 40% of Materials Yield Limit time, and intensity is maximum; The intensity of tension bolt can be thinning weak along with the increase of pretightening force; Be subject to the bolt of shearing and stretching action, pre-tight stress is about 40% of Materials Yield Limit time, and intensity is maximum simultaneously.
Be now that extruding produces plastic deformation because screw thread is subject to excessive external force by bolt generation inefficacy major part, can assert what screw-down torque excessive (pretightening force is excessive) caused.
China Patent No. is " manufacture method of high strength nut " (announcement on June 15th, 1994) of CN1087848, disclose a kind of manufacture method of high strength nut, main technical schemes is: the preceding apparatus of cold header is Medium Frequency Induction Heating Furnace, and production process is: (1) warms; (2) upsetting shape; (3) tap; (4) heat treatment.
Metric thread is divided into coarse thread (60 °) and closely-pitched (60 °), and the externally threaded pitch of coarse thread M30 bolt is 3.50mm, and the degree of depth of screw thread is 1.75mm, and root diameter (i.e. the diameter of thread bottom is called for short footpath, the end) is 26.50mm.
CNS (GB/T923-2009) " hexagonal acorn nut ", is applicable to the nut of side hemisphere hole sealing structure.
CNS (GB/T6171-2000) " 1 type hexagon nut closely-pitched ", M30 × 2 hexagon nut thickness Mmax=25.6mm, Mmin=24.3mm.
CNS (GB/T6176-2000) " 2 type hexagon nut closely-pitched ", M30 × 2 hexagon nut thickness Mmax=28.6mm, Mmin=27.3mm.
CNS (GB/T5785-2000) " hexagon head bolt closely-pitched ", M30 × 2 hexagon bolt head nominal height K=18.7mm.
There is safety coefficient allowable during Bolt Connection, be generally 1.5 ~ 2.5 times (calculating by stress amplitude).
Summary of the invention
In order to the phenomenon easily occurring loosening when overcoming existing Bolt Connection, this patent deal with problems adopted technological scheme be adopt " two screw retention method ", specifically describe as follows:
1, coupling same center of circle longitudinal center line is processed with two different-diameters screw contrary with thread rotary orientation, be called fastening screw and locking screw holes, the center drilling of the clamping bolt body of rod, clamping bolt and fastening screw connect, lock bolt passes center hole and the locking screw holes connection of the clamping bolt body of rod, jointly carries out fastening to coupling;
2, drilling on coupling, locking nut is different with the internal thread diameter of tightening nut and rotation direction contrary, and clamping bolt and tightening nut connect, and lock bolt passes center hole and the locking nut connection of the clamping bolt body of rod, jointly carries out fastening to coupling;
3, pad and locking nut and tightening nut carry out welding or being made of one becoming " anti-turning nut ", " anti-turning nut " arranges the different and internal thread that rotation direction is contrary of two groups of diameters, clamping bolt and " anti-turning nut " connect, lock bolt connects with " anti-turning nut " through the center hole of the clamping bolt body of rod, jointly carries out fastening to coupling;
The technological points of two screw retention method is clamping bolt and lock bolt is two independently bolts, external thread diameter and the rotation direction of clamping bolt and lock bolt are different, internal thread diameter and the rotation direction of locking nut and tightening nut are different, the center hole of the clamping bolt body of rod is the service of assembling lock bolt, the appearance of " anti-turning nut ", makes the integration of locking nut and tightening nut become possibility.Locking nut in background technique and tightening nut integration have 3 kinds of situations later:
1, be equivalent to a nut, do not have locking effect, such as double nut (rotation direction of two nut threads is identical);
2, use and cannot dismantle after welding, can only single use, such as " inverse rotation direction double nut " (rotation direction of two nut threads be contrary);
3, cannot use after integration, such as " inverse rotation direction double nut ".
Lock bolt and clamping bolt can select material, processing technology and suitable pretightening force as required, because two groups of derotations have " interlocking " effect to screw thread, so nut or bolt can not turn round, reach locking effect, be also applicable to require that coupling can do the occasion etc. of fixed-axis rotation around clamping bolt.
The beneficial effect of this patent is the reliability that can improve Bolt Connection, and can use when lower pretightening force, and extend bolt life, part can adopt standard piece, can be applicable to the connection that multiple occasion is especially important.
Accompanying drawing explanation
Below in conjunction with accompanying drawing, this patent is described further.
Fig. 1 is the section of structure of bolt and coupling.The longitudinal center line in the same center of circle of Left-wing Federation's fitting is processed with the screw that two different-diameters are contrary with thread rotary orientation, major diameter screw is called fastening screw, small-diameter screw-hole is called locking screw holes, right coupling drilling (boring or fraising), the body of rod center drilling (through-hole structure) of clamping bolt.Clamping bolt nose shape is for outer-hexagonal, and within lock bolt nose shape, hexagonal is example.Clamping bolt connects fastening screw distich fitting and carries out fastening, and lock bolt connects through the center hole of the clamping bolt body of rod and locking screw holes, and lock bolt head compresses clamping bolt head.Effective tensile elongation of lock bolt screw rod is B, and effective tensile elongation of clamping bolt screw rod is right coupling thickness.If the less thick of Left-wing Federation's fitting, then become through hole structure.
Fig. 2 is the right elevation (omitting coupling) of Fig. 1.
Fig. 3 is bolt, nut and coupling the 1st kind of section of structure.Two couplings are boring, use clamping bolt, lock bolt, tightening nut, locking nut and plain cushion (one of pad) to connect, and clamping bolt and tightening nut compress coupling, and locking nut compresses tightening nut by plain cushion.This kind of similar is in " the inverse rotation direction double nut " that installed plain cushion additional.The shape of tightening nut and locking nut is for outer-hexagonal.All the other are identical with Fig. 1.
Fig. 4 is the left view (omitting coupling) of Fig. 3.The circumcircle of locking nut outer-hexagonal equals the incircle of tightening nut outer-hexagonal, and the external diameter of plain cushion equals the incircle of tightening nut outer-hexagonal.
Fig. 5 is bolt, nut and coupling the 2nd kind of section of structure.Plain cushion and locking nut and tightening nut are welded into one (for preventing excessive deformation, can peripherally spot welding).All the other are identical with Fig. 3.
Fig. 6 is bolt, nut and coupling the 3rd kind of section of structure.After locking nut and plain cushion are made of one, and tightening nut welds.Also after tightening nut and plain cushion can being made of one, and locking nut welds.All the other are identical with Fig. 3.
The left view of Fig. 6 is identical with Fig. 4 (removing solder joint).
Fig. 7 is CNS (GB/T923-2009) " hexagonal acorn nut " sectional drawing.G1 is tool withdrawal groove length, and M24 × 2 hexagonal acorn nut G1max is 10.7mm in First Series, is 7.3mm in second series.
If the shape at outer-hexagonal place becomes circle and (such as becomes the circumcircle or incircle etc. of outer-hexagonal, but the minimum incircle that should be not less than outer-hexagonal of diameter), be referred to as " dome-shaped nut ", also can be changed into other outer polyhedral angles, therefore can be divided into dome-shaped nut and outer polyhedral angle acorn nut (comprising hexagonal acorn nut), be referred to as in this manual " acorn nut ".
Fig. 8 is the left view of Fig. 7.
Fig. 9 is locking nut, plain cushion and tightening nut be made of one after section of structure, be referred to as " anti-turning nut ".
In " anti-turning nut ", the screw thread at locking nut place is called locking screw (left side minor diameter screw thread), and the screw thread at tightening nut place is called binding thread (right side large-diameter thread).Inside clearance between locking screw and binding thread is worth from desirable G1max=10.7mm as reference.
Figure 10 is bolt, nut and coupling the 4th kind of section of structure." anti-turning nut " and coupling, bolt connect, and " anti-turning nut " left side is through hole structure.All the other are identical with Fig. 3.
Figure 11 is the left view (omitting coupling) of Figure 10.The profile at locking nut place becomes circle and (such as becomes the circumcircle or incircle etc. of locking nut outer-hexagonal, but the minimum incircle that should be not less than outer-hexagonal of diameter), its diameter equals the circumcircle of locking nut outer-hexagonal, the outer-hexagonal shape invariance at tightening nut place, is called single outer-hexagonal " anti-turning nut ".
If the profile at tightening nut place becomes circle, the outer-hexagonal shape invariance at locking nut place, also referred to as single outer-hexagonal " anti-turning nut ", so single outer-hexagonal " anti-turning nut " is divided into again large hexagonal " anti-turning nut " and little hexagonal " anti-turning nut ".Large hexagonal " anti-turning nut " the i.e. profile at locking nut place is circular, the outer-hexagonal shape invariance at tightening nut place; Little hexagonal " anti-turning nut " the i.e. profile at tightening nut place is circular, the outer-hexagonal shape invariance at locking nut place.If tightening nut place and tightening nut place profile all become circle, be then called circle " anti-turning nut ".If the outer-hexagonal shape at tightening nut place and tightening nut place is all constant, be then called two outer-hexagonal " anti-turning nut ", left view is identical with Fig. 4.
Figure 12 is bolt, nut and coupling the 5th kind of section of structure." anti-turning nut " left side is hemisphere hole sealing structure, is called hole-sealing " anti-turning nut ".Every make nut not expose screw be referred to as hole sealing structure.
Figure 13 is bolt, nut and coupling the 6th kind of section of structure.Locking nut compresses tightening nut by " bowl-type " pad (another kind of pad), and similar is in " the inverse rotation direction double nut " that installed " bowl-type " pad additional.Lock bolt head, locking nut and tightening nut adopt outer-hexagonal.All the other are identical with Fig. 3.
" bowl-type " pad is identical with the purposes of plain cushion, is referred to as pad.
Figure 14 is bolt, nut and coupling the 7th kind of section of structure.Locking nut, " bowl-type " pad and tightening nut are made of one becomes two outer-hexagonal " anti-turning nut ", and the inside clearance between locking screw and binding thread is worth from desirable G1max=10.7mm as reference.All the other are identical with Figure 13.
If use hole-sealing " anti-turning nut ", substantially identical with Figure 12.
Figure 15 is the left view (omitting coupling) of Figure 14.The profile at " anti-turning nut " locking nut place becomes circle, becomes large hexagonal " anti-turning nut ".If when the profile at tightening nut place becomes circle, the outer-hexagonal shape invariance at locking nut place, then become little hexagonal " anti-turning nut ".
Figure 16 is bolt, nut and coupling the 8th kind of section of structure.Lock bolt and clamping bolt use stud bolt, use rigid sleeve to carry out spacing between two couplings.All the other are identical with Figure 13.
Tu1Zhong 1. Left-wing Federation fitting, 2. right coupling, 3. clamping bolt, 4. lock bolt
5. locking nuts, 6. plain cushion, 7. tightening nut in Fig. 3
8. solder joints in Fig. 5
9. anti-turning nuts in Fig. 9
10. " bowl-type " pad in Figure 13
11. rigid sleeves in Figure 16
Embodiment
In Fig. 1 embodiment, after the screw of Left-wing Federation's fitting (1) and the boring of right coupling (2) are aimed at, clamping bolt (3) connects through the boring of right coupling (2) and the fastening screw of Left-wing Federation's fitting (1), tightens clamping bolt (3) and meets the requirements of pretightening force.Lock bolt (4) penetrates the center hole of clamping bolt (3), connect with the locking screw holes of Left-wing Federation's fitting (1), tighten lock bolt (4) and meet the requirements of pretightening force, the head of lock bolt (4) compresses the head of clamping bolt (3).The body of rod length of clamping bolt (3) and lock bolt (4) will strictly control, and prevents the bottom being screwed into screw.Because locking screw holes and fastening screw adopt derotation to screw thread, because " interlocking " effect is so Left-wing Federation's fitting (1) can not turn round, and to become that pair to organize screw thread stressed compared with single bolt with using, the linking intensity of screw thread can also be improved.Locking principle describe: Left-wing Federation's fitting (1) because of derotation to screw thread " interlocking " act on can not turn round, when vibrating, impacting, the trend that clamping bolt (3) can loosen, but the pine due to clamping bolt (3) moves back the tightening direction that direction is lock bolt (4), tightening of lock bolt (4) prevents the pine of clamping bolt (3) to move back, and causes clamping bolt (3) to get loose.As long as the screw threads of component etc. meet the requirements, can repeated disassembled and assembled, do not affect coupling performance simulating.If expose circular hole or internal thread after Left-wing Federation's fitting (1) less thick, become through hole structure, do not affect coupling performance simulating.
Fixed-axis rotation can be done around clamping bolt (3) to ask right coupling (2), then gap must be established between two couplings or between the head of right coupling (2) and clamping bolt (3), clamping bolt (3) need grasp the degree of depth being screwed into fastening screw, reserve suitable gap, then be screwed into lock bolt (4) and pretension, anti-loosing effect is better than using wall scroll bolt.
In Fig. 3 embodiment, after the boring aligning of Left-wing Federation's fitting (1) and right coupling (2), clamping bolt (3) connects through boring and tightening nut (7) and carries out fastening to coupling after pretension, lock bolt (4) penetrates the center hole of clamping bolt (3), install plain cushion (6) additional to connect with locking nut (5) afterwards, locking nut (5) compresses tightening nut (7), locking nut (5) and tightening nut (7) can be considered realization " interlocking ", and locking principle is identical with " inverse rotation direction double nut " in background technique.Clamping bolt (3) body of rod length will strictly control, and prevents the body of rod left end from withstanding locking nut (5), makes locking nut (5) cannot compress tightening nut (7).The boundary dimension of locking nut (5) should match with tightening nut (7) and plain cushion (6), locking nut (5) boundary dimension can be slightly less than tightening nut (7), and preferably the circumcircle of locking nut (5) outer-hexagonal equals the incircle of tightening nut (7) outer-hexagonal.Plain cushion (6) internal diameter should slightly larger than the diameter of clamping bolt (3), external diameter can equal the incircle of tightening nut (7) outer-hexagonal, thickness is greater than clamping bolt (3) exposed length and reserves appropriate gap, and exposed length is the thickness sum that clamping bolt (3) body of rod length deducts two couplings and tightening nut (7).Locking nut (5) can use the nut (such as acorn nut) of band hole sealing structure to replace.All the other are identical with Fig. 1 embodiment.
If clamping bolt and lock bolt use stud bolt, clamping bolt is identical with the structure that left end nut connects with the right-hand member head construction of lock bolt, uses screw bolt and nut jointly to carry out fastening to coupling.
In Fig. 5 embodiment, locking nut (5), plain cushion (6) and tightening nut (7) integrally welded (can peripherally spot welding), nut can not turn round, and is conducive to locking, does not also affect dismounting.All the other are identical with Fig. 3 embodiment.
In Fig. 6 embodiment, after locking nut (5) and plain cushion (6) are made of one, with tightening nut (7) welding, or after tightening nut (7) and plain cushion (6) be made of one, and locking nut (5) welds.If replace locking nut (5) with acorn nut, after being made of one with plain cushion (6), weld with tightening nut (7), or after tightening nut (7) and plain cushion (6) are made of one, weld with acorn nut, all be conducive to preventing nut loosening, also do not affect dismounting.All the other are identical with Fig. 5 embodiment.
In Figure 10 embodiment, anti-turning nut (9) is two outer-hexagonal structures, clamping bolt (3) and lock bolt (4) are all screwed into anti-turning nut (9), carry out fastening to coupling, so long as not artificial dismounting, anti-turning nut (9) can not turn round loosening.All the other are identical with Fig. 3 embodiment.
Fixed-axis rotation can be done around clamping bolt (3) to ask coupling, then gap must be established between two couplings or between the head of right coupling (2) and clamping bolt (3), between Left-wing Federation's fitting (1) and anti-turning nut (9), clamping bolt (3) need grasp the degree of depth being screwed into anti-turning nut (9), reserve appropriate gap, lock bolt (4) is screwed into anti-turning nut (9) and pretension, and anti-loosing effect is better than using wall scroll bolt and double nut.
In Figure 12 embodiment, use the anti-turning nut (9) of hemisphere hole sealing structure, can prevent sleet dust etc. from entering internal thread, play the effect of protection screw thread, can working life be increased under comparatively harsh natural condition.All the other are identical with Figure 10 embodiment.
In Figure 13 embodiment, locking nut (5) compresses tightening nut (7) by " bowl-type " pad (10), the Main Function of " bowl-type " pad (10) ensures that the locking nut (5) that boundary dimension is less can compress the relatively large tightening nut of boundary dimension (7), " bowl-type " pad (10) will have enough rigidity, otherwise can affect coupling performance simulating.To appropriate gap be reserved between the left end of " bowl-type " pad (10) and clamping bolt (3) body of rod, prevent clamping bolt (3) body of rod left end from withstanding " bowl-type " pad (10).The head of lock bolt (4) and afterbody use capable of reversing, can use locking nut (5) to compress the head of clamping bolt (3).All the other are identical with Fig. 3 embodiment.
Locking nut (5), " bowl-type " pad (10) and tightening nut (7) can be welded into one and use, identical with Fig. 5 embodiment; Locking nut (5) and " bowl-type " pad (10) are made of one, weld with tightening nut (7), or tightening nut (7) and " bowl-type " pad (10) are made of one, with locking nut (5) welding, identical with Fig. 6 embodiment.
In Figure 14 embodiment, locking nut (5), " bowl-type " pad (10) and tightening nut (7) are made of one becomes anti-turning nut (9) use, and all the other are identical with Figure 13 embodiment.
To ask coupling can do fixed-axis rotation around clamping bolt (3), identical with the using method that Figure 10 embodiment is correlated with.If anti-turning nut (9) is hole-sealing structure, identical with Figure 12 embodiment.
In Figure 16 embodiment, use rigid sleeve (11) to carry out spacing between two couplings, clamping bolt (3) and lock bolt (4) use stud bolt, and bolt length increases, store more elastic deformation energy, anti-loosing effect can be more better.All the other are identical with Figure 13 embodiment.
After clamping bolt (3) pretension, clamping bolt (3) and tightening nut (7) or anti-turning nut (9) is pinned with instrument when tightening lock bolt (4) or locking nut (5), prevent from, because clamping bolt (3) or tightening nut (7) reversion cause pretightening force to decline, affecting fastening effect.
If when coupling does fixed-axis rotation around clamping bolt (3), after connecting, clamping bolt (3) bears compressive stress, lock bolt (4) bears tensile stress, should note not bearing excessive stress time pretension lock bolt (4).
During dismounting coupling, first can dismantle lock bolt (4) or locking nut (5), then pull down clamping bolt (3) or the component such as tightening nut (7), anti-turning nut (9).
When dismantling circular anti-turning nut (9) or dome-shaped nut, the instruments such as pipe wrench can be used to pin circular anti-turning nut (9) or dome-shaped nut, first pull down lock bolt (4), pull down clamping bolt (3) again, take out circular anti-turning nut (9); Or first pull down dome-shaped nut, take out lock bolt (4), then pull down tightening nut (7), take out clamping bolt (3).
After anti-turning nut (9) makes two outer-hexagonals or little hexagonal configuration, use the more shallow interior Hexagonal jacket of the degree of depth just can pin anti-turning nut (9) and carry out dismounting lock bolt (4) and clamping bolt (3).In fact, just the welded pair of anti-turning nut of outer-hexagonal (9) is become after plain cushion (6) or " bowl-type " pad (10) and locking nut (5) and tightening nut (7) welding; In like manner, after locking nut (5) and plain cushion (6) or " bowl-type " pad (10) are made of one, weld with tightening nut (7), or tightening nut (7) and plain cushion (6) or " bowl-type " pad (10) are made of one, weld with locking nut (5), also become the welded pair of anti-turning nut of outer-hexagonal (9).If locking nut (5) and plain cushion (6) or " bowl-type " pad (10) all do circular one, and tightening nut (7) welds, and just becomes the anti-turning nut of welded large hexagonal (9); Tightening nut (7) and plain cushion (6) or " bowl-type " pad (10) all do circular one, and locking nut (5) welds, and just becomes the anti-turning nut of welded little hexagonal (9).If the profile of tightening nut (7) and locking nut (5) is all circular, and plain cushion (6) or " bowl-type " pad (10) weld, then become the anti-turning nut of welded circle (9); If replace locking nut (5) with acorn nut, just become the anti-turning nut of welded hole-sealing (9).Therefore anti-turning nut (9) can be divided into following several:
1, the anti-turning nut of welding type (9)
2, Integral back turning nut (9)
3, the anti-turning nut of single outer-hexagonal (9)
4, the anti-turning nut of two outer-hexagonal (9)
5, circular anti-turning nut (9)
6, the anti-turning nut of thru hole type (9)
7, the anti-turning nut of hole-sealing (9)
Each anti-turning nut (9) can be divided into different profiles and structure again:
The anti-turning nut of welding type (9) can be divided into thru hole type, hole-sealing, large hexagonal, little hexagonal and circle, " 3 the close 1 " structure also having locking nut (5), plain cushion (6) or " bowl-type " pad (10) and tightening nut (7) to weld in addition; After locking nut (5) and plain cushion (6) or " bowl-type " pad (10) are made of one, with " 2-in-1 1 " structure that tightening nut (7) welds, " 2-in-1 1 " structure also comprises tightening nut (7) and plain cushion (6) or " bowl-type " pad (10) and is made of one, and the form that locking nut (5) welds.
Integral back turning nut (9) can be divided into thru hole type, hole-sealing, large hexagonal, little hexagonal and circle.
The single anti-turning nut of outer-hexagonal (9) can be divided into thru hole type, hole-sealing, welding type, integrated type, large hexagonal and little hexagonal.
The anti-turning nut of two outer-hexagonal (9) can be divided into thru hole type, hole-sealing, welding type and integrated type.
Circular anti-turning nut (9) can be divided into thru hole type, hole-sealing, welding type and integrated type.
The anti-turning nut of thru hole type (9) can be divided into welding type, integrated type, large hexagonal, little hexagonal and circle.
The anti-turning nut of hole-sealing (9) can be divided into welding type, integrated type, large hexagonal, little hexagonal and circle.
The single anti-turning nut of outer-hexagonal (9) also can be other outer polyhedral angles, is referred to as " single outer polyhedral angle " anti-turning nut (9).
The anti-turning nut of two outer-hexagonal (9) also can be other outer polyhedral angles, is referred to as " two outer polyhedral angle " anti-turning nut (9).
After entity bolt becomes clamping bolt (3) and lock bolt (4) uses, because lock bolt (4) and clamping bolt (3) mainly rely on derotation to carry out locking to " interlocking " effect of screw thread, can not turn round loosening under the double action of " interlocking " and pretightening force, the Main Function of pretightening force becomes " connection ", overcoming some existing bolt relies on merely increase pretightening force to carry out locking deficiency, and lock bolt (4) and clamping bolt (3) can no longer need too large pretightening force, in addition according in background technique " when bolt axial pre tightening force is increased to 0.45 σ s by 0.25 σ s, anti-loosing effect improves 13.2 times ", draw " when bolt axial pre tightening force is increased to 0.4 σ s by 0.25 σ s, anti-loosing effect improves about 10 times ", no matter be therefore high-strength bolt or plain bolt, if the pretightening force of clamping bolt (3) and lock bolt (4) controls at 0.4 σ s, working life can be improved and ensure maximum strength (when withstanding shocks load), add the double action of derotation to screw thread " interlocking ", pretension and locking requirement can be met.Under special circumstances, the pretightening force of clamping bolt (3) or lock bolt (4) can lower than 0.4 σ s, total pretightening force due to clamping bolt (3) and lock bolt (4) equals the two pretightening force sum, total pretightening force is equivalent to act on the pretightening force on entity bolt, if entity bolt pretightening is not less than 0.4 σ s, pretension and locking requirement also can be met.
The selection of lock bolt (4) and clamping bolt (3) diameter and the Distribution Calculation of pretightening force:
1st kind of computational methods. the diameter selecting lock bolt (4) is calculated according to " pairs of anti-loose nut structure stress is comparatively suitable with P1=0.2P, P2=0.8P " in background technique.
8.8 grades of M30 × 2 scyewed joint are used for coupling in Figure 10, entity diameter of bolt D=30mm, the effective tensile elongation L=65mm of screw rod (equaling two coupling thickness sums), nut is tightened with 1450Nm moment, during entity bolt pretightening P=269kN, bolt elastic elongation amount Δ L=0.118mm, bolt stress σ=381Mpa, yield strength σ s=640Mpa, σ/σ s=0.6 (computational process is shown in background technique " bolt elongate amount calculated example ").Entity bolt becomes clamping bolt (3) and lock bolt (4) carries out fastening to coupling afterwards together with anti-turning nut (9), the diameter (external diameter) of clamping bolt (3), material, processing technology, Young's modulus, screw thread and effectively tensile elongation is identical with entity bolt.
The pretightening force F1=P1=0.2P of lock bolt (4), the pretightening force F2=P2=0.8P of clamping bolt (3), total pretightening force F=F1+F2=0.2P+0.8P=P of clamping bolt (3) and lock bolt (4).
The length of anti-turning nut (9) binding thread is that 25.6mm (gets 1 type M30 × 2 hexagon nut thickness Mmax=25.6mm, also other numerical value desirable), inside clearance between locking screw and binding thread (gets M24 × 2 hexagonal acorn nut G1max First Series value 10.7mm from for 10.7mm, also desirable second series value 7.3mm or other appropriate value), the height of head of clamping bolt (3) gets nominal height K=18.7mm, so effective tensile elongation L1=120mm (L1=65+25.6+10.7+18.7=120mm) of lock bolt (4).Effective tensile elongation L2=L=65mm of clamping bolt (3).
If the material, processing technology, Young's modulus, stress etc. of lock bolt (4) are identical with entity bolt, just the effective tensile elongation L1 of lock bolt (4) compares with entity bolt and is increased to 120mm, therefore its elastic elongation amount Δ L1 should be increased to 0.218mm (Δ L1=Δ L × 120/L=0.118 × 120/65=0.218mm) by direct proportaion.
If lock bolt (4) pretightening force F1=P1=0.2P=0.2 × 269=53.8kN, the sectional area S1 of lock bolt (4) is:
S1＝F1×L1/(E×ΔL1)＝53.8×10
3×120×10
-3/(210×10
9×0.218×10
-3)＝141.0mm
2
The diameter d of lock bolt (4) is:
d＝(4×S1/3.14)
1/2＝(4×141.0/3.14)
1/2＝13.4mm
Get d=14mm, select 8.8 grades of M14 bolts as lock bolt (4), the sectional area S1 of lock bolt (4) is:
S1＝3.14×d
2/4＝3.14×14
2×10
-6/4＝153.9mm
2
The sectional area S of entity bolt is:
S＝3.14×D
2/4＝3.14×30
2×10
-6/4＝706.5mm
2
Because the internal diameter difference of lock bolt (4) diameter and fastening screw (3) body of rod center hole is very little, can ignore in gap, so the sectional area S2 of 8.8 grades of clamping bolts (3) is:
S2＝S-S1＝706.5-153.9＝552.6mm
2
Clamping bolt (3) and lock bolt (4) are under pretightening force effect, and elastic elongation amount generally can not be identical, but when bearing work loads, elastic elongation amount is identical.Optimal cases is: clamping bolt (3) and lock bolt (4) under the effect of pretightening force and maximum working load common close to or arrive yield strength, reach the maximum load-carrying capacity (resistance to tension) of opposing load, i.e. " elastic elongation amount when requiring clamping bolt (3) and lock bolt (4) to be loaded into yield strength from pretightening force is identical ", referred to as " requirement that elastic elongation amount is identical ".
Calculate pretightening force and the bolt maximum load-carrying capacity of lock bolt (4) and clamping bolt (3):
According to " high strength exploitation must adopt larger pretightening force, and general pretightening force should be 70% ~ 81.2% of this bolt material yield strength " in background technique, the therefore desirable 0.8 σ s of high-strength bolt pretightening force.The error of reference nut (bolt) controlling angle pretightening force, greatly about ± 15%, is considered the impact of pretightening force operate miss, prevent pretightening force higher than 0.8 σ s, therefore pretightening force is got 0.68 σ s (0.8 × 0.85=0.68).If pretightening force reaches the upper limit 115%, then actual pretightening force is 0.78 σ s (0.68 × 1.15=0.78 < 0.8), meet the requirement " adopting the pretightening force of bolt to be less than 80% of the Materials Yield Limit of bolt, and get high value as far as possible " in background technique.
If 1.1 lock bolts (4) pretightening force F1 gets 0.68 σ s (i.e. pre-tight stress σ 1=0.68 σ s), according to " requirement that elastic elongation amount is identical ", calculate above-mentioned " using 8.8 grades of M30 × 2 scyewed joint for coupling in Figure 10 " (the 1st kind of computational methods related content) clamping bolt (3) pretightening force F2 and bolt maximum load-carrying capacity.
When lock bolt (4) is loaded into yield strength from zero, elastic elongation amount is Δ L1q, when being loaded into pretightening force F1 from zero, elastic elongation amount is Δ L1, when being loaded into yield strength from pretightening force F1, elastic elongation amount is Δ L1z, therefore Δ L1z=Δ L1q-Δ L1.
The pretightening force F1 of lock bolt (4) is:
F1＝σ1×S1＝0.68×σs×3.14×d
2/4＝0.68×640×10
6×3.14×(14×10
-3)
2/4
＝66960N≈67KN
Tensile force f 1q when lock bolt (4) is loaded into yield strength from zero is:
F1q＝σs×S1＝σs×3.14×d
2/4＝640×10
6×3.14×14
2×10
-6/4＝98470N≈98.5KN
When lock bolt (4) is loaded into yield strength from zero, elastic elongation amount Δ L1q is:
ΔL1q＝F1q×L1/(E×S1)＝σs×L1/E＝640×10
6×120×10
-3/(210×10
9)＝0.366mm
When lock bolt (4) is loaded into pretightening force F1 from zero, elastic elongation amount Δ L1 is:
ΔL1＝F1×L1/(E×S1)＝σ1×L1/E＝0.68×σs×L1/E
＝0.68×640×10
3×120×10
-3/(210×10
9)＝0.249mm
When lock bolt (4) is loaded into yield strength from pretightening force F1, elastic elongation amount Δ L1z is:
ΔL1z＝ΔL2z＝ΔL1q-ΔL1＝0.366-0.249＝0.117mm
The determination of clamping bolt (3) pretightening force:
When clamping bolt (3) is loaded into yield strength from zero, elastic elongation amount is Δ L2q, and when being loaded into yield strength from pretightening force, elastic elongation amount is Δ L2z, according to " requirement that elastic elongation amount is identical ", and Δ L2z=Δ L1z; When clamping bolt (3) is loaded into pretightening force from zero, elastic elongation amount is Δ L2, because Δ L2=Δ L2q-Δ L2z=Δ L2q-Δ L1z, therefore is the pretightening force F2 of clamping bolt (3) from zero pulling force be loaded into needed for Δ L2.
Tensile force f 2q when clamping bolt (3) is loaded into yield strength from zero is:
F2q＝σs×S2＝σs×(3.14×D
2/4-3.14×d
2/4)
＝640×10
6×3.14×[(30×10
-3)
2/4-(14×10
-3)
2/4]＝353689N≈353.7KN
When clamping bolt (3) is loaded into yield strength from zero, elastic elongation amount Δ L2q is:
ΔL2q＝F2q×L2/(E×S2)＝σs×L2/E＝640×10
6×65×10
-3/(210×10
9)＝0.198mm
According to " requirement that elastic elongation amount is identical ", when clamping bolt (3) is loaded into pretightening force F2 from zero, elastic elongation amount Δ L2 is:
ΔL2＝ΔL2q-ΔL1z＝0.198-0.117＝0.081mm
When clamping bolt (3) is loaded into Δ L2=0.081mm from zero, required pulling force and pretightening force F2 are:
F2＝ΔL2×E×S2/L2＝ΔL2×E×3.14×[(D×10
-3/2)
2-(d×10
-3/2)
2]/L2
＝0.081×10
-3×210×10
9×3.14×[(30×10
-3/2)
2-(14×10
-3/2)
2]/(65×10
-3)
＝144621N≈144.6KN
The stress σ 2 (pre-tight stress) of clamping bolt (3) when pretightening force is F2 is:
σ2＝F2/S2＝F2/(3.14×D
2/4-3.14×d
2/4)
＝144.6×10
3/(3.14×30
2×10
-6/4-3.14×14
2×10
-6/4)＝262Mpa
σ 2/ σ s=262/640=0.41 > 0.4 (meeting the requirements)
Total pretightening force F=F1+F2=67+144.6=211.6kN of lock bolt (4) and clamping bolt (3).
As 8. ε level M30 × 2 entity bolt pretightening P=F=211.6kN, stress σ is:
σ＝P/S＝F/(3.14×D
2/4)＝211.6×10
3/(3.14×30
2×10
-6/4)＝300Mpa
σ/σ s=300/640=0.47 > 0.4 (meeting the requirements)
When the pretightening force F1 of lock bolt (4) gets 0.68 σ s, the pretightening force F2 of clamping bolt (3) is 0.41 σ s, and being equivalent to 8.8 grades of M30 × 2 entity bolt pretightenings is 0.47 σ s, higher than 0.4 σ s, can meet pretension and locking requirement.
The maximum load-carrying capacity of lock bolt (4) and clamping bolt (3) is:
F1q+F2q＝98.5+353.7＝452.2KN≈450KN
When the pretightening force of lock bolt (4) is 0.68 σ s, the pretightening force of clamping bolt (3) is 0.41 σ s, just prove that lock bolt (4) and clamping bolt (3) are under the effect of work loads from theory calculate, during synchronous arrival yield strength, elastic elongation amount is 0.117mm.There is safety coefficient during Bolt Connection, generally can not reach yield strength when Selection and Design, bolt more can not be made to transship.
The impact of 1.2 consideration pretightening force operate miss ± 15%, if the pretightening force of lock bolt (4) and clamping bolt (3) all cappings 115%, according to 1.1 correlation calculation result, lock bolt (4) pretightening force F1 is 0.78 σ s (0.68 × 1.15=0.78), i.e. pre-tight stress σ 1=0.78 σ s; Clamping bolt (3) pretightening force F2 is 0.47 σ s (0.41 × 1.15=0.47), i.e. pre-tight stress σ 2=0.47 σ s, calculates total pretightening force F and the maximum load-carrying capacity of bolt.
The pretightening force F1 of lock bolt (4) is:
F1＝σ1×S1＝0.78×σs×3.14×d
2/4＝0.78×640×10
6×3.14×(14×10
-3)
2/4
＝76807N≈76.8KN
The pretightening force F2 of clamping bolt (3) is:
F2＝σ2×S2＝0.47×σs×3.14×[(D×10
-3/2)
2-(d×10
-3/2)
2]
＝0.47×640×3.14×[(30×10
-3/2)
2-(14×10
-3/2)
2]＝166234N≈166.2KN
Total pretightening force F=F1+F2=76.8+166.2=243kN of lock bolt (4) and clamping bolt (3).
If 8.8 grades of M30 × 2 entity bolt pretightening P=F=243kN, stress σ is:
σ＝P/S＝F/(3.14×D
2/4)＝243×10
3/(3.14×30
2×10
-6/4)＝344Mpa
σ/σ s=344/640=0.54 > 0.4 (meeting the requirements)
When lock bolt (4) pretightening force is 0.78 σ s, when clamping bolt (3) pretightening force is 0.47 σ s, being equivalent to 8.8 grades of M30 × 2 entity bolt pretightenings is 0.54 σ s, higher than 0.4 σ s, can meet locking requirement.
Tensile force f 1q=98.5KN when lock bolt (4) is loaded into yield strength from zero:
F1q=σ s × S1=98470N ≈ 98.5KN (computational process is shown in 1.1 computational methods)
When lock bolt (4) is loaded into yield strength from zero, elastic elongation amount Δ L1q=0.366mm:
Δ L1q=F1q × L1/ (E × S1)=0.366mm (computational process is shown in 1.1 computational methods)
When lock bolt (4) is loaded into pretightening force F1 from zero, elastic elongation amount Δ L1 is:
ΔL1＝F1×L1/(E×S1)＝σ1×L1/E＝0.78×σs×L1/E
＝0.78×640×10
3×120×10
-3/(210×10
9)＝0.285mm
When lock bolt (4) is loaded into yield strength from pretightening force F1, elastic elongation amount Δ L1z is:
ΔL1z＝ΔL2z＝ΔL1q-ΔL1＝0.366-0.285＝0.081mm
When clamping bolt (3) is loaded into yield strength from zero, elastic elongation amount Δ L2q=0.198mm:
Δ L2q=F2q × L2/ (E × S2)=0.198mm (computational process is shown in 1.1 computational methods)
When clamping bolt (3) is loaded into pretightening force F2 from zero, elastic elongation amount Δ L2 is:
ΔL2＝F2×L2/(E×S2)＝σ2×L2/E＝0.47×σs×L2/E
＝0.47×640×10
3×65×10
-3/(210×10
9)＝0.093mm
When clamping bolt (3) is loaded into yield strength from pretightening force F2, elastic elongation amount Δ L2z is:
ΔL2z＝ΔL2q-ΔL2＝0.198-0.093＝0.105mm＞ΔL1z＝0.081mm
Illustrate that lock bolt (4) reaches yield strength in advance than clamping bolt (3), the two synchronous elastic elongation amount increased is Δ L1z=0.08mm, clamping bolt (3) from Δ L2=0.093mm synchronous with lock bolt (4) when increasing Δ L1z=0.081mm required tensile force f j be:
Fj＝(ΔL2+ΔL1z)×E×S2/L2＝(ΔL2+ΔL1z)×E×3.14×[(D×10
-3/2)
2-(d×10
-3/2
2)]/L2
＝(0.093+0.081)×210×10
9×3.14×[(30×10
-3/2)
2-(14×10
-3/2)
2]/(65×10
-3)
＝310669N≈310.7KN
Clamping bolt (3) reaches (not yet reaching Δ L2q=0.198mm) when tensile force f j and elastic elongation amount are Δ L2+ Δ L1z=0.093+0.081=0.174mm, and lock bolt (4) has arrived yield strength (Δ L1q reaches 0.366mm).
Lock bolt (4) reaches maximum load-carrying capacity when arriving yield strength together with clamping bolt (3), and its value is:
F1q+Fj＝98.5+310.7＝409.2KN≈410KN
The impact of 1.3 consideration pretightening force operate miss ± 15%, if the pretightening force of lock bolt (4) and clamping bolt (3) all removes the limit 85%, according to 1.1 correlation calculation result, lock bolt (4) pretightening force F1 is 0.58 σ s (0.68 × 0.85=0.58), i.e. pre-tight stress σ 1=0.58 σ s; Clamping bolt (3) pretightening force F2 is 0.35 σ s (0.41 × 0.85=0.35), i.e. pre-tight stress σ 2=0.35 σ s, calculates total pretightening force F and the maximum load-carrying capacity of bolt.
The pretightening force F1 of lock bolt (4) is:
F1＝σ1×S1＝0.58×σs×3.14×d
2/4＝0.58×640×10
6×3.14×(14×10
-3)
2/4
＝57113N≈57.1KN
The pretightening force F2 of clamping bolt (3) is:
F2＝σ2×S2＝0.35×σs×3.14×[(D×10
-3/2)
2-(d×10
-3/2)
2]
＝0.35×640×3.14×[(30×10
-3/2)
2-(14×10
-3/2)
2]＝123791N≈123.8KN
Total pretightening force F=F1+F2=57.1+123.8=180.9kN of lock bolt (4) and clamping bolt (3).
As 8.8 grades of M30 × 2 entity bolt pretightening P=F=180.9kN, stress σ is:
σ＝P/S＝F/(3.14×D
2/4)＝180.9×10
3/(3.14×30
2×10
-6/4)＝256Mpa
σ/σ s=256/640=0.4 (meeting the requirements)
Be 0.58 σ s in lock bolt (4) pretightening force, when clamping bolt (3) pretightening force is 0.35 σ s, being equivalent to 8.8 grades of M30 × 2 entity bolt pretightenings is 0.4 σ s, can be used for the occasion that ask for something suitably reduces pretightening force, can meet locking requirement.
Tensile force f 1q=98.5KN when lock bolt (4) is loaded into yield strength from zero:
F1q=σ s × S1=98470N ≈ 98.5KN (computational process is shown in 1.1 computational methods)
When lock bolt (4) is loaded into yield strength from zero, elastic elongation amount Δ L1q=0.366mm.
Δ L1q=F1q × L1/ (E × S1)=0.366mm (computational process is shown in 1.1 computational methods)
When lock bolt (4) is loaded into pretightening force F1 from zero, elastic elongation amount Δ L1 is:
ΔL1＝F1×L1/(E×S1)＝σ1×L1/E＝0.58×σs×L1/E＝0.58×640×10
3×120×10
-3/(210×10
9)＝0.212mm
When lock bolt (4) is loaded into yield strength from pretightening force F1, elastic elongation amount Δ L1z is:
ΔL1z＝ΔL2z＝ΔL1q-ΔL1＝0.366-0.212＝0.154mm
When clamping bolt (3) is loaded into yield strength from zero, elastic elongation amount Δ L2q=0.198mm:
Δ L2q=F2q × L2/ (E × S2)=0.198mm (computational process is shown in 1.1 computational methods)
When clamping bolt (3) is loaded into pretightening force F2 from zero, elastic elongation amount Δ L2 is:
ΔL2＝F2×L2/(E×S2)＝σ2×L2/E＝0.35×σs×L2/E
＝0.35×640×10
3×65×10
-3/(210×10
9)＝0.069mm
When clamping bolt (3) is loaded into yield strength from pretightening force F2, elastic elongation amount Δ L2z is:
ΔL2z＝ΔL2q-ΔL2＝0.198-0.069＝0.129mm＜ΔL1z＝0.154mm
Illustrate that clamping bolt (3) reaches yield strength in advance than lock bolt (4), the two synchronous elastic elongation amount increased is Δ L2z=0.129mm, lock bolt (4) from Δ L1=0.212mm synchronous with clamping bolt (3) when increasing Δ L2z=0.129mm required tensile force f s be:
Fs＝(ΔL1+ΔL2z)×E×S1/L1＝(ΔL1+ΔL2z)×E×3.14×(d×10
-3/2)
2/L1
＝(0.212+0.129)×210×10
9×3.14×(14×10
-3/2)
2/(120×10
-3)
＝91816N≈91.8KN
Lock bolt (4) reaches (not yet reaching Δ L1q=0.366mm) when tensile force f s and elastic elongation amount are Δ L1+ Δ L2z=0.212+0.129=0.341mm, and clamping bolt (3) has arrived yield strength (Δ L2q reaches 0.198mm).
Clamping bolt (3) reaches maximum load-carrying capacity when arriving yield strength together with lock bolt (4), and its value is:
F2q+Fs＝353.7+91.8＝445.5KN≈450KN
If 1.4 lock bolts (4) pretightening force F1 gets 0.68 σ s (i.e. pre-tight stress σ 1=0.68 σ s), do not adopt the computational methods of " requirement that elastic elongation amount is identical ", it is P-F1 that clamping bolt (3) pretightening force F2 directly gets the remaining pretightening force of entity bolt, calculate the maximum load-carrying capacity of bolt, computational methods that the method is called " residue pretightening force ".
" residue pretightening force " computational methods are adopted to calculate the bolt maximum load-carrying capacity of above-mentioned " using 8.8 grades of M30 × 2 scyewed joint for coupling in Figure 10 " (the 1st kind of computational methods related content).
The F1=67KN when the pretightening force of lock bolt (4) gets 0.68 σ s:
F1=σ 1 × S1=66960N ≈ 67KN (computational process is shown in 1.1 computational methods)
Tensile force f 1q=98.5KN when lock bolt (4) is loaded into yield strength from zero:
F1q=σ s × S1=98470N ≈ 98.5KN (computational process is shown in 1.1 computational methods)
When lock bolt (4) is loaded into yield strength from zero, elastic elongation amount Δ L1q=0.366mm:
Δ L1q=F1q × L1/ (E × S1)=0.366mm (computational process is shown in 1.1 computational methods)
When lock bolt (4) is loaded into pretightening force F1 from zero, elastic elongation amount Δ L1=0.249mm:
Δ L1=F1 × L1/ (E × S1)=0.249mm (computational process is shown in 1.1 computational methods)
When lock bolt (4) is loaded into yield strength from pretightening force F1, elastic elongation amount Δ L1z is:
ΔL1z＝ΔL1q-ΔL1＝0.366-0.249＝0.117mm
Pretightening force F2 and the stress σ 2 of clamping bolt (3) are:
F2＝P-F1＝269-67＝202KN
σ2＝F2/S2＝F2/(3.14×D
2/4-3.14×d
2/4)
＝202×10
3/[3.14×(30×10
-3)
2/4-3.14×(14×10
-3)
2/4]＝366Mpa
σ 2/ σ s=366/640=0.57 > 0.4 (meeting the requirements)
When clamping bolt (3) is loaded into pretightening force F2 from zero, elastic elongation amount Δ L2 is:
ΔL2＝F2×L2/(E×S2)＝σ2×L2/E＝0.57×σs×L2/E
＝0.57×640×10
3×65×10
-3/(210×10
9)＝0.113mm
When clamping bolt (3) is loaded into yield strength from zero, elastic elongation amount Δ L2q=0.198mm:
Δ L2q=F2q × L2/ (E × S2)=0.198mm (computational process is shown in 1.1 computational methods)
When clamping bolt (3) is loaded into yield strength from pretightening force F2, elastic elongation amount Δ L2z is:
ΔL2z＝ΔL2q-ΔL2＝0.198-0.113＝0.085mm＜ΔL1z＝0.117mm
Illustrate that clamping bolt (3) reaches yield strength in advance than lock bolt (4), the two synchronous elastic elongation amount increased is Δ L2z=0.085mm, lock bolt (4) from Δ L1=0.249mm synchronous with clamping bolt (3) when increasing Δ L2z=0.085mm required tensile force f s be:
Fs＝(ΔL1+ΔL2z)×E×S1/L1＝(ΔL1+ΔL2z)×E×3.14×(d×10
-3/2)
2/L1
＝(0.249+0.085)×210×10
9×3.14×(14×10
-3/2)
2/(120×10
-3)
＝89931N≈89.9KN
Lock bolt (4) reaches (not yet reaching Δ L1q=0.366mm) when tensile force f s and elastic elongation amount are Δ L1+ Δ L2z=0.249+0.085=0.334mm, and clamping bolt (3) has arrived yield strength (Δ L2q reaches 0.198mm).
Clamping bolt (3) reaches maximum load-carrying capacity when arriving yield strength together with lock bolt (4), and its value is:
F2q+Fs＝353.7+89.9＝443.6KN≈440KN
When using high-strength bolt, if consider the impact of pretightening force operate miss ± 15%, the desirable 0.68 σ s (0.8 × 0.85=0.68) of pretightening force high value of lock bolt (4) and clamping bolt (3), the desirable 0.47 σ s (0.4/0.85=0.471 ≈ 0.47) of lower value, the mean value 0.58 σ s (0.68/2+0.47/2=0.575 ≈ 0.58) of the desirable high value of intermediate value and lower value.If the pretightening force of lock bolt (4) and clamping bolt (3) all gets high value 0.68 σ s, consider the pretightening force upper limit 115%, pretightening force is 0.78 σ s (0.68 × 1.15=0.78), is also no more than 0.8 σ s; If all get lower value 0.47 σ s, consider pretightening force lower limit 85%, pretightening force is 0.4 σ s (0.47 × 0.85=0.3995 ≈ 0.4), also can meet the demands.
Due to the impact of pretightening force operate miss, realize " requirement that elastic elongation amount is identical " (i.e. 1.1 computational methods) more difficult, 1.1 computational methods provide reference when needed, therefore, after entity bolt pretightening is determined, 1.4 computational methods can be adopted to carry out calculating the pretightening force of clamping bolt (3) and lock bolt (4).1.2 is that lock bolt (4) is different with the sequencing that clamping bolt (3) reaches yield strength with the difference of 1.3 computational methods.
2nd kind of computational methods. according to " high strength exploitation must adopt larger pretightening force; general pretightening force should be 70% ~ 81.2% of this bolt material yield strength " in background technique, select the diameter of lock bolt (4) by pre-tight stress σ 1=0.8 σ s and pretightening force P1=0.2P.
" using 8.8 grades of M30 × 2 entity Bolt Connection for coupling in Figure 10 " of the same 1st kind of computational methods, 8.8 grade bolt yield strength σ s are 640Mpa, and the stress σ 1 of lock bolt (4) is:
σ1＝0.8σs＝0.8×640＝512Mpa
During lock bolt (4) pretightening force F1=P1=0.2P=0.2 × 269=53.8kN, the sectional area S1 of lock bolt (4) is:
S1＝F1/σ1＝53.8×10
3/(512×10
6)＝105.08mm
2
The diameter d of lock bolt (4) is:
d＝(4×S1/3.14)
1/2＝(4×105.08/3.14)
1/2＝11.57mm
The ratio of lock bolt (4) diameter d and entity diameter of bolt D is:
d/D＝11.57/30＝0.39≈0.4
Therefore 8.8 grades of lock bolts (4) are when σ 1/ σ s=0.8, pretightening force F1=0.2P, and the diameter d of lock bolt (4) equals 0.4 times of entity bolt or clamping bolt (3) diameter D, i.e. d=0.4D.
Can using the diameter d=0.4D of lock bolt (4) as lower limit, because lock bolt (4) stress σ 1 reaches the limit of, but clamping bolt (3) and lock bolt (4) are if use different materials, the yield strength of lock bolt (4) is relatively high, the sectional area of lock bolt (4) still can continue to diminish, and the diameter of lock bolt (4) can reduce again.
If the diameter d of lock bolt (4) gets 12mm, 8.8 grades of M12 bolts can be selected as lock bolt (4).
The pretightening force calculating etc. of lock bolt (4) and clamping bolt (3) can refer to 1.4 related contents in the 1st kind of computational methods.
3rd kind of computational methods. calculate so that clamping bolt (3) is equal with lock bolt (4) sectional area the diameter selecting lock bolt (4).
The sectional area S of entity bolt is:
S＝3.14×(D/2)
2＝3.14×D
2/4
After entity bolt becomes clamping bolt (3) and lock bolt (4), the sectional area S1 of lock bolt (4) is:
S1＝3.14×(d/2)
2＝3.14×d
2/4
The sectional area S2 of clamping bolt (3) is:
S2＝S-S1＝3.14×(D/2)
2-3.14×(d/2)
2＝3.14×D
2/4-3.14×d
2/4
To ask the sectional area of lock bolt (4) and clamping bolt (3) equal, then:
S1＝S2＝3.14×D
2/4-3.14×d
2/4＝3.14×d
2/4
Calculate: d=(D/2)
1/2
The ratio of lock bolt (4) diameter d and entity diameter of bolt D is:
d/D＝(1/2)
1/2＝1/1.414＝0.707
Can using d=0.707D as the upper limit, lock bolt (4) maximum diameter is 0.707D, the desirable integer being slightly less than 0.707D of lock bolt (4) diameter, when bolt material is identical with processing technology, lock bolt (4) sectional area can not be greater than clamping bolt (3) sectional area, otherwise can affect the intensity of clamping bolt (3).But clamping bolt (3) and lock bolt (4) are if use different materials or processing technology, clamping bolt (3) yield strength is relatively high, when lock bolt (4) sectional area is greater than clamping bolt (3) sectional area, clamping bolt (3) bearing capacity is still relatively large, then lock bolt (4) diameter can increase again.
The pretightening force calculating etc. of lock bolt (4) and clamping bolt (3) can refer to 1.4 related contents in the 1st kind of computational methods equally.
4th kind of computational methods. according to " high strength exploitation must adopt larger pretightening force; general pretightening force should be 70% ~ 81.2% of this bolt material yield strength " in background technique, equal entity bolt pretightening P with clamping bolt (3) maximum pretightening force Fmax and carry out selection lock bolt (4) diameter, and require that clamping bolt (3) pretightening force F2 is not more than 0.8 σ s.
Because entity bolt pretightening P equals the pretightening force sum of clamping bolt (3) and lock bolt (4), i.e. total pretightening force F, but tighten lock bolt (4) afterwards clamping bolt (3) pretightening force F2 will reduce, the amplitude reduced equals the pretightening force F1 of lock bolt (4), to ask clamping bolt (3) also can reach required pretightening force after tightening lock bolt (4), so maximum pretightening force Fmax should equal entity bolt pretightening P during assembling clamping bolt (3).This kind of situation is equally applicable to the 1st kind, the 2nd kind and the 3rd kind of computational methods.
" using 8.8 grades of M30 × 2 entity Bolt Connection for coupling in Figure 10 " of the same 1st kind of computational methods, select 8.8 grades of M14 bolts as lock bolt (4), the pretightening force of lock bolt (4) is F1=67KN, and the pretightening force of clamping bolt (3) is F2=202KN (result that 1.4 computational methods draw).The maximum pretightening force Fmax=P=F=F1+F2=67+202=269KN of clamping bolt (3), after lock bolt (4) loading pretightening force (F1=67KN), clamping bolt (3) actual pretightening force is F2=Fmax-F1=269-67=202KN, but after dismounting lock bolt (4), the pretightening force F2 of clamping bolt (3) rebounds again and is reduced into Fmax, i.e. F2=Fmax=269KN.
The sectional area S of entity bolt is:
S＝3.14×(D/2)
2＝3.14×D
2/4
The sectional area S1 of lock bolt (4) is:
S1＝3.14×(d/2)
2＝3.14×d
2/4
The sectional area S2 of clamping bolt (3) is:
S2＝S-S1＝3.14×(D/2)
2-3.14×(d/2)
2＝3.14×(D
2-d
2)/4
Pulling force when entity bolt reaches λ times of yield strength and pretightening force P are:
P＝λ×σs×S＝λ×σs×3.14×D
2/4
If pulling force when clamping bolt (3) reaches 0.8 σ s equals Fmax, then:
Fmax＝0.8×σs×S2＝0.8×σs×3.14×(D
2-d
2)/4
To ask P=Fmax, then:
P＝Fmax＝λ×σs×3.14×D
2/4＝0.8×σs×3.14×(D
2-d
2)/4
Simplify: λ × D
2=0.8 × (D
2-d
2)
Calculate: d=[(1-λ/0.8)]
1/2× D
When λ=0.672: d=[(1-0.672/0.8)]
1/2× D=0.4D
During i.e. λ=σ/σ s≤0.672, d >=0.4D;
When λ=0.6: d=[(1-λ/0.8)]
1/2× D=[(1-0.6/0.8)]
1/2× D=0.5D
During i.e. λ=σ/σ s=0.6, d=0.5D;
As d=(D/2)
1/2time: λ=0.8 × (D
2-d
2)/D
2=0.8 × (1-d
2/ D
2)=0.8 (1-1/2)=0.4
During i.e. λ=σ/σ s >=0.4, d≤0.707D.
So when 0.4≤λ≤0.672,0.707D >=d >=0.4D is closed interval.
The stress σ 2 checking clamping bolt (3) is carried out with " clamping bolt (3) maximum pretightening force Fmax equals entity bolt pretightening P ":
The same 1st kind of computational methods " use 8.8 grades of M30 × 2 entity Bolt Connection for coupling in Figure 10 ", select 8.8 grades of M14 bolts as lock bolt (4), as clamping bolt (3) maximum pretightening force Fmax=P=269KN, stress σ 2 is:
σ2＝Fmax/S2＝P/(3.14×D
2/4-3.14×d
2/4)
＝269×10
3/[3.14×(30×10
-3)
2/4-3.14×(14×10
-3)
2/4)]＝487Mpa
8.8 grade bolt yield strength σ s=640Mpa, σ 2/ σ s=487/640=0.76 < 0.8 (meeting the requirements).
Therefore 8.8 grades of M14 bolts are selected to meet the requirements as lock bolt (4).In like manner select 8.8 grades of M12 bolts larger as clamping bolt (3) sectional area time lock bolt (4), σ 2/ σ s is also less than 0.8, so also meet the requirements.
5th kind of computational methods. when clamping bolt (3) maximum pretightening force Fmax equals entity bolt pretightening P, consider the impact of pretightening force operate miss ± 15%, if clamping bolt (3) maximum pretightening force Fmax gets 0.68 σ s, entity bolt pretightening P gets 0.47 σ s (i.e. pre-tight stress σ=0.47 σ s), calculates the diameter of lock bolt (4).
Become lock bolt (4) and clamping bolt (3) for 8.8 grades of M30 × 2 entity bolts, when entity bolt pretightening gets 0.47 σ s, pretightening force P is:
P＝σ×S＝0.47×σs×3.14×D
2/4＝0.47×640×10
6×3.14×(30×10
-3)
2/4
＝212515N≈212.5KN
The sectional area S of 8.8 grades of entity bolts is:
S＝3.14×D
2/4＝3.14×D
2/4＝3.14×30
2×10
-6/4＝706.5mm
2
If 8.8 grades of maximum pretightening force Fmax of clamping bolt (3) are 0.68 σ s, equal entity bolt pretightening P, the sectional area S2 of clamping bolt (3) is:
S2＝Fmax/(0.68×σs)＝P/(0.68×σs)＝212.5×10
3/(0.68×640×10
6)＝488.3mm
2
The sectional area S1 of 8.8 grades of lock bolts (4) is:
S1＝S-S2＝706.5-488.3＝218.2mm
2
The diameter d of lock bolt (4) is:
d＝(4×S1/3.14)
1/2＝(4×218.2/3.14)
1/2＝16.67mm
Therefore the desirable 16mm of diameter d of 8.8 grades of lock bolts (4).
The pretightening force calculating etc. of lock bolt (4) and clamping bolt (3) can refer to the 1st kind of computational methods 1.4 related content.
If entity bolt, clamping bolt (3) and lock bolt (4) are high-strength bolt, when yield strength is identical, there is following characteristics:
1. entity bolt pretightening requires 0.4 σ s≤P≤0.8 σ s;
2. lock bolt (4) pretightening force requires 0.4 σ s≤F1≤0.8 σ s;
3. clamping bolt (3) pretightening force requires 0.4 σ s≤F2≤0.8 σ s;
4., when clamping bolt (3) maximum pretightening force Fmax equals entity bolt pretightening P, require σ 2≤0.8 σ s;
5. λ=σ/inversely proportional the relation of σ s of lock bolt (4) diameter d and entity bolt.
During regular screw threads connect, the maximum pretightening force of entity bolt or maximum pre-tight stress are 0.78 σ s, if consider the impact of pretightening force operate miss ± 15%, become lock bolt (4) and clamping bolt (3) the desirable 0.66 σ s (0.78 × 0.85=0.663 ≈ 0.66) of pretightening force high value afterwards, the desirable 0.47 σ s (0.4/0.85=0.471 ≈ 0.47) of lower value, the mean value 0.57 σ s (0.663/2+0.471/2=0.567 ≈ 0.57) of the desirable high value of intermediate value and lower value.If the pretightening force of lock bolt (4) and clamping bolt (3) all gets high value 0.66 σ s, consider the pretightening force upper limit 115%, pretightening force is 0.76 σ s (0.66 × 1.15=0.759 ≈ 0.76), is also no more than 0.78 σ s; If all get lower value 0.47 σ s, consider pretightening force lower limit 85%, pretightening force is 0.4 σ s (0.47 × 0.85=0.3995 ≈ 0.4), also can meet the demands.
6th kind of computational methods. select lock bolt (4) diameter by clamping bolt (3) maximum pretightening force and maximum pre-tight stress, and consider the impact of pretightening force operate miss ± 15%, calculate bolt maximum load-carrying capacity and clamping bolt (3) pretightening force.
Use 5.6 grades of M30 × 2 scyewed joint for coupling in Figure 10, entity diameter of bolt D=30mm, the effective tensile elongation L=65mm of screw rod, yield strength σ s=500 × 0.6=300Mpa, require σ/σ s=0.58.Entity bolt becomes clamping bolt (3) and lock bolt (4) carries out fastening to coupling afterwards together with anti-turning nut (9).
Clamping bolt (3) diameter (external diameter), screw thread, effectively tensile elongation, material and processing technology are identical with entity bolt, and material and the processing technology of lock bolt (4) are identical with entity bolt.The length of anti-turning nut (9) binding thread gets 25.6mm, inside clearance between locking screw and binding thread is from getting 10.7mm, the height of head of clamping bolt (3) gets 18.7mm, therefore the effective tensile elongation L1 of lock bolt (4) is 120mm (with reference to the 1st kind of computational methods related content).Clamping bolt (3) is tensile elongation L2=L=65mm effectively.
The pretightening force P of 5.6 grades of M30 × 2 entity bolts is:
P＝σ×S＝0.58×σs×3.14×D
2/4＝0.58×300×10
6×3.14×(30×10
-3)
2/4
＝122931N≈122.9KN
The sectional area S of 5.6 grades of M30 × 2 entity bolts is:
S＝3.14×D
2/4＝3.14×(30×10
-3)
2/4＝706.5mm
2
As σ/σ s=0.78, the maximum pretightening force Pmax of 5.6 grades of M30 × 2 entity bolts is:
Pmax＝σ×S＝0.78×σs×3.14×D
2/4＝0.78×300×10
6×3.14×(30×10
-3)
2/4
＝165321N≈165.3KN
When illustrating that the pretightening force of 5.6 grades of M30 × 2 entity bolts or clamping bolt (3) reaches Pmax=165.3KN, outside thread bottom of trench starts to destroy, and when pretightening force is less than Pmax, outside thread answers no problem.
As 5.6 grades of maximum pretightening force Fmax=P=122.9KN of clamping bolt (3), when maximum pre-tight stress is 0.78 σ s=0.78 × 300=234Mpa, the sectional area S2 that clamping bolt (3) at least needs is:
S2＝Fmax/(0.78×σs)＝P/(0.78×σs)＝122.9×10
3/(234×10
-6)＝525.2mm
2
The sectional area S1 of lock bolt (4) is:
S1＝S-S2＝706.5-525.2＝181.3mm
2
The diameter d of lock bolt (4) is:
d＝(4×S1/3.14)
1/2＝(4×181.3/3.14)
1/2＝15.2mm
The desirable numerical value being not more than 15.2mm of diameter d of lock bolt (4), if be greater than 15.2mm, can make the sectional area S2 of clamping bolt (3) not enough.
If the diameter of lock bolt (4) gets d=14mm, 5.6 grades of M14 bolts can be selected as lock bolt (4).
When the pretightening force F1 of 5.6 grades of M14 lock bolts (4) gets 0.66 σ s (i.e. pre-tight stress σ 1=0.66 σ s), when the residue pretightening force that clamping bolt (3) pretightening force F2 gets entity bolt is P-F1, calculate the maximum load-carrying capacity of bolt:
The pretightening force F1 of lock bolt (4) is:
F1＝σ1×S1＝0.66σs×S1＝0.66×300×10
6×3.14×(14×10
-3)
2/4＝30464N≈30.5KN
Pretightening force F2 and the stress σ 2 of clamping bolt (3) are:
F2＝P-F1＝122.9-30.5＝92.4KN
σ2＝F2/S2＝F2/(3.14×D
2/4-3.14×d
2/4)
＝92.4×10
3/(3.14×30
2×10
-6/4-3.14×14
2×10
-6/4)＝167Mpa
Because of 5.6 grade bolt yield strength σ s=300Mpa, σ 2/ σ s=167/300=0.56 < 0.78 (meeting the requirements), namely the pretightening force F2 of clamping bolt (3) is 0.56 σ s.
As clamping bolt (3) maximum pretightening force Fmax=P=122.9KN, stress σ 2 is:
σ2＝Fmax/S2＝P/(3.14×D
2/4-3.14×d
2/4)
＝122.9×10
3/(3.14×30
2×10
-6/4-3.14×14
2×10
-6/4)＝222Mpa
σ 2/ σ s=222/300=0.74 < 0.78 (meeting the requirements)
When lock bolt (4) is loaded into pretightening force F1 from zero, elastic elongation amount Δ L1 is:
ΔL1＝F1×L1/(E×S1)＝σ1×L1/E＝0.66×σs×L1/E
＝0.66×300×10
6×120×10
-3/(200×10
9)＝0.119mm
Because 5.6 grade bolts are plain bolt, elastic modulus E gets 200 × 10
3mpa.
When lock bolt (4) is loaded into yield strength from zero, elastic elongation amount Δ L1q is:
ΔL1q＝F1q×L1/(E×S1)＝σs×L1/E＝300×10
6×120×10
-3/(200×10
9)＝0.180mm
When lock bolt (4) is loaded into yield strength from pretightening force F1, elastic elongation amount Δ L1z is:
ΔL1z＝ΔL1q-ΔL1＝0.180-0.119＝0.061mm
Tensile force f 2q when clamping bolt (3) is loaded into yield strength from zero is:
F2q＝σs×S2＝σs×(3.14×D
2/4-3.14×d
2/4)
＝300×10
6×3.14×[(30×10
-3)
2/4-(14×10
-3)
2/4]＝165792N≈165.8KN
When clamping bolt (3) is loaded into pretightening force F2 from zero, elastic elongation amount Δ L2 is:
ΔL2＝F2×L2/(E×S2)＝σ2×L2/E＝0.56×σs×L2/E
＝0.56×300×10
6×65×10
-3/(200×10
9)＝0.055mm
When clamping bolt (3) is loaded into yield strength from zero, elastic elongation amount Δ L2q is:
ΔL2q＝F2q×L2/(E×S2)＝σs×L2/E＝300×10
6×65×10
-3/(200×10
9)＝0.096mm
When clamping bolt (3) is loaded into yield strength from pretightening force F2, elastic elongation amount Δ L2z is:
ΔL2z＝ΔL2q-ΔL2＝0.096-0.055＝0.041mm＜ΔL1z＝0.061mm
Illustrate that clamping bolt (3) reaches yield strength in advance than lock bolt (4), the two synchronous elastic elongation amount increased is Δ L2z=0.041mm, lock bolt (4) from Δ L1=0.119mm synchronous with clamping bolt (3) when increasing Δ L2z=0.041mm required tensile force f s be:
Fs＝(ΔL1+ΔL2z)×E×S1/L1＝(ΔL1+ΔL2z)×E×3.14×(d×10
-3/2)
2/L1
＝(0.119+0.041)×200×10
9×3.14×(14×10
-3/2)
2/(120×10
-3)＝41029N≈41KN
Lock bolt (4) pulling force is Fs and elastic elongation amount when arriving Δ L1+ Δ L2z=0.119+0.041=0.160mm (not yet reaching Δ L1q=0.180mm), and clamping bolt (3) has reached yield strength (Δ L2q=0.096mm).
When 5.6 grades of M30 × 2 entity bolts reach yield strength, maximum load-carrying capacity is:
σs×S＝σs×3.14×D
2/4＝300×10
6×3.14×(30×10
-3)
2/4＝211950N≈212KN
Clamping bolt (3) reaches maximum load-carrying capacity when arriving yield strength together with lock bolt (4), and its value is:
F2q+Fs=165.8+41=206.8KN ≈ 207KN (being slightly less than 212KN)
Consider the impact of pretightening force operate miss ± 15%, upper limit Fmax1 and the lower limit Fmax2 of clamping bolt (3) maximum pretightening force are:
Fmax1＝1.15×Fmax＝1.15×122.9＝141.3KN
Fmax2＝0.85×Fmax＝0.85×122.9＝104.5KN
Consider the impact of pretightening force operate miss ± 15%, upper limit F11 and the lower limit F12 of lock bolt (4) pretightening force are:
F11＝1.15×σ1×S1＝1.15×0.66×σs×S1＝0.76×σs×3.14×d
2/4
＝0.76×300×10
6×3.14×(14×10
-3)
2/4＝35080N≈35.1KN
F12＝0.85×σ1×S1＝1.15×0.66×σs×S1＝0.56×σs×3.14×d
2/4
＝0.56×300×10
6×3.14×(14×10
-3)
2/4＝25848N≈25.8KN
When the pretightening force of lock bolt (4) is upper limit F11=35.1KN or lower limit F12=25.8KN, maximum pretightening force Fmax and the stress σ 2 of clamping bolt (3) are:
1, when clamping bolt (3) maximum pretightening force is upper limit Fmax1=141.3KN, when lock bolt (4) pretightening force is lower limit F12=25.8KN, maximum pretightening force Fmax and the stress σ 2 of clamping bolt (3) are:
Fmax＝Fmax1-F12＝141.3-25.8＝115.5KN
σ2＝Fmax/S2＝Fmax/(3.14×D
2/4-3.14×d
2/4)
＝115.5×10
3/(3.14×30
2×10
-6/4-3.14×14
2×10
-6/4)＝209Mpa
σ 2/ σ s=209/300 ≈ 0.7 < 0.78 (meeting the requirements)
2, when clamping bolt (3) maximum pretightening force is lower limit Fmax2=104.5KN, when lock bolt (4) pretightening force is upper limit F11=35.1KN, maximum pretightening force Fmax and the stress σ 2 of clamping bolt (3) are:
Fmax＝Fmax2-F11＝104.5-35.1＝69.4KN
σ2＝Fmax/S2＝Fmax/(3.14×D
2/4-3.14×d
2/4)
＝69.4×10
3/(3.14×30
2×10
-6/4-3.14×14
2×10
-6/4)＝126Mpa
σ 2/ σ s=126/300=0.42 > 0.4 (meeting the requirements)
When clamping bolt (3) maximum pretightening force is within the scope of upper and lower bound, when lock bolt (4) pretightening force is in lower limit and upper range, clamping bolt (3) pretightening force is 0.7 σ s >=F2 >=0.42 σ s.Illustrate anyway clamping bolt (3) maximum pretightening force and lock bolt (4) pretightening force change between respective upper and lower bound, clamping bolt (3) pretightening force, all the time between 0.42 σ s ~ 0.7 σ s, can meet pretension and the requirement such as locking.
Consider the upper limit and the lower limit of clamping bolt (3) maximum pretightening force and lock bolt (4) pretightening force, bolt maximum load-carrying capacity (in reference the 1st kind of computational methods 1.2 or 1.3) should be calculated respectively by following four kinds of conditions, use minimum value checking computations safety coefficient:
1, lock bolt (4) pretightening force is the upper limit 0.76 σ s, and clamping bolt (3) pretightening force is the upper limit 0.7 σ s;
2, lock bolt (4) pretightening force is lower limit 0.56 σ s, and clamping bolt (3) pretightening force is lower limit 0.42 σ s;
3, lock bolt (4) pretightening force is the upper limit 0.76 σ s, and clamping bolt (3) pretightening force is lower limit 0.42 σ s;
4, lock bolt (4) pretightening force is lower limit 0.56 σ s, and clamping bolt (3) pretightening force is the upper limit 0.7 σ s.
When clamping bolt (3) maximum pretightening force is upper limit Fmax1=141.3KN, stress σ 2 is:
σ2＝Fmax/S2＝Fmax/(3.14×D
2/4-3.14×d
2/4)
＝141.3×10
3/(3.14×30
2×10
-6/4-3.14×14
2×10
-6/4)＝256Mpa
σ2/σs＝256/300＝0.85
Clamping bolt (3) stress σ 2 is 0.85 σ s, belongs to " exceeding standard " temporarily, because lock bolt (4) pretightening force is when lower limit 0.56 σ s, σ 2 is only 0.7 σ s, meets the requirements.The maximum pretightening force upper limit Fmax1 of clamping bolt (3) is 141.3KN, is less than Pmax (165.3KN), illustrates that the outside thread of clamping bolt (3) answers no problem.
When entity bolt, lock bolt (4) or clamping bolt (3) are plain bolt, when yield strength is identical, pretightening force should meet the following requirements:
1. entity bolt pretightening General Requirements 0.4 σ s≤P≤0.58 σ s;
2. lock bolt (4) pretightening force requires 0.4 σ s≤F1≤0.78 σ s;
3. clamping bolt (3) pretightening force requires 0.4 σ s≤F2≤0.78 σ s;
4., when clamping bolt (3) maximum pretightening force Fmax equals entity bolt pretightening P, require σ 2≤0.78 σ s.
Stress σ 2 with the related content of the 6th kind of computational methods checking computations " using 8.8 grades of M30 × 2 scyewed joint for coupling in Figure 10 " (the 1st kind of computational methods related content) clamping bolt (3):
Consider the impact of pretightening force operate miss ± 15%, upper limit Fmax1 and the lower limit Fmax2 of clamping bolt (3) maximum pretightening force are:
Fmax1＝1.15×Fmax＝1.15×269＝309.2KN
Fmax2＝0.85×Fmax＝0.85×269＝228.7KN
Consider the impact of pretightening force operate miss ± 15%, upper limit F11 and the lower limit F12 of lock bolt (4) pretightening force are:
F11＝1.15×σ1×S1＝1.15×0.68×σs×S1＝0.78×σs×3.14×d
2/4
＝0.78×640×10
6×3.14×(14×10
-3)
2/4＝76807N≈76.8KN
F12＝0.85×σ1×S1＝1.15×0.58×σs×S1＝0.58×σs×3.14×d
2/4
＝0.58×640×10
6×3.14×(14×10
-3)
2/4＝57113N≈57.1KN
When the pretightening force of lock bolt (4) is upper limit F11=76.8KN or lower limit F12=57.1KN, maximum pretightening force Fmax and the stress σ 2 of clamping bolt (3) are:
1, when clamping bolt (3) maximum pretightening force is upper limit Fmax1=309.2KN, when lock bolt (4) pretightening force is lower limit F12=57.1KN, clamping bolt (3) maximum pretightening force Fmax and stress σ 2 is:
Fmax＝Fmax1-F12＝309.2-57.1＝252.1KN
σ2＝Fmax/S2＝Fmax/(3.14×D
2/4-3.14×d
2/4)
＝252.1×10
3/(3.14×30
2×10
-6/4-3.14×14
2×10
-6/4)＝456Mpa
σ 2/ σ s=456/640=0.71 < 0.78 (meeting the requirements)
2, when clamping bolt (3) maximum pretightening force is lower limit Fmax2=228.7KN, when lock bolt (4) pretightening force is upper limit F11=76.8KN, maximum pretightening force Fmax and the stress σ 2 of clamping bolt (3) are:
Fmax＝Fmax2-F11＝228.7-76.8＝151.9KN
σ2＝Fmax/S2＝Fmax/(3.14×D
2/4-3.14×d
2/4)
＝151.9×10
3/(3.14×30
2×10
-6/4-3.14×14
2×10
-6/4)＝275Mpa
σ 2/ σ s=275/640=0.43 > 0.4 (meeting the requirements)
When clamping bolt (3) maximum pretightening force is within the scope of upper and lower bound, when lock bolt (4) pretightening force is in lower limit and upper range, clamping bolt (3) pretightening force is 0.71 σ s >=F2 >=0.43 σ s.Illustrate anyway clamping bolt (3) maximum pretightening force and lock bolt (4) pretightening force change between respective upper and lower bound, clamping bolt (3) pretightening force, all the time between 0.43 σ s ~ 0.71 σ s, can meet pretension and the requirement such as locking.
Consider the upper limit and the lower limit of clamping bolt (3) maximum pretightening force and lock bolt (4) pretightening force, bolt maximum load-carrying capacity (in reference the 1st kind of computational methods 1.2 or 1.3) should be calculated respectively by following four kinds of conditions, use minimum value checking computations safety coefficient:
1, lock bolt (4) pretightening force is the upper limit 0.78 σ s, and clamping bolt (3) pretightening force is the upper limit 0.71 σ s;
2, lock bolt (4) pretightening force is lower limit 0.58 σ s, and clamping bolt (3) pretightening force is lower limit 0.43 σ s;
3, lock bolt (4) pretightening force is the upper limit 0.78 σ s, and clamping bolt (3) pretightening force is lower limit 0.43 σ s;
4, lock bolt (4) pretightening force is lower limit 0.58 σ s, and clamping bolt (3) pretightening force is the upper limit 0.71 σ s.
When clamping bolt (3) maximum pretightening force is upper limit Fmax1=309.2KN, stress σ 2 is:
σ2＝Fmax/S2＝Fmax/(3.14×D
2/4-3.14×d
2/4)
＝309.2×10
3/(3.14×30
2×10
-6/4-3.14×14
2×10
-6/4)＝559Mpa
σ2/σs＝559/640＝0.87
The stress σ 2 of clamping bolt (3) is 0.87 σ s, belongs to " exceeding standard " temporarily, because lock bolt (4) pretightening force is when lower limit 0.58 σ s, σ 2 is only 0.71 σ s, meets the requirements.
As σ/σ s=0.8,8.8 grades of M30 × 2 maximum pretightening force Pmax of entity bolt are:
Pmax＝σ×S＝0.8×σs×3.14×D
2/4＝0.8×640×10
6×3.14×(30×10
-3)
2/4
＝361728N≈361.7KN
8.8 grades of maximum pretightening force Pmax=361.7KN of M30 × 2 entity bolt, are greater than the maximum pretightening force upper limit Fmax1 (309.2KN) of clamping bolt (3), illustrate that the outside thread of clamping bolt (3) answers no problem.
The load if Bolt Connection withstands shocks, the pretightening force of lock bolt (4) and clamping bolt (3) all can get 0.4 σ s.
The diameter of clamping bolt (3) and lock bolt (4) and pretightening force calculate selects flow process:
1. determine the pretightening force P of entity bolt;
2. with the diameter d of the 1st kind, the 2nd kind, the 3rd kind, the 4th kind, the 5th kind or the 6th kind computational methods selection lock bolt (4);
3. determine the pretightening force F1 of lock bolt (4), be generally 0.68 σ s (high-strength bolt) or 0.66 σ s (plain bolt), the residue pretightening force that the pretightening force F2 of clamping bolt (3) gets entity bolt is P-F1;
4. equal with the maximum pretightening force Fmax of clamping bolt (3) the stress σ 2 that entity bolt pretightening P checks clamping bolt (3), require that σ 2 is not more than 0.8 σ s (high-strength bolt) or 0.78 σ s (plain bolt);
5. by clamping bolt (3) and lock bolt (4) pretightening force simultaneously capping, remove the limit and to intersect four kinds of conditions of value with upper and lower and calculate bolt maximum load-carrying capacity respectively simultaneously, get minimum value checking computations safety coefficient;
6. upper limit Fmax1 and the lower limit Fmax2 of clamping bolt (3) maximum pretightening force is calculated by pretightening force operate miss ± 15%;
7. upper limit F11 and the lower limit F12 of lock bolt (4) pretightening force is calculated by pretightening force operate miss ± 15%;
8. deduct the force value of lock bolt (4) pretightening force lower limit F12 for Fmax with the upper limit Fmax1 of clamping bolt (3) maximum pretightening force, calculate the stress σ 2 of clamping bolt (3), require that σ 2 is not more than 0.8 σ s (high-strength bolt) or 0.78 σ s (plain bolt);
9. deduct the force value of lock bolt (4) pretightening force upper limit F11 for Fmax with the lower limit Fmax2 of clamping bolt (3) maximum pretightening force, calculate the stress σ 2 of clamping bolt (3), require that σ 2 is not less than 0.4 σ s (high-strength bolt or plain bolt).
If there is undesirable phenomenon in calculation process, the method process reducing lock bolt (4) diameter or use high-yield strength clamping bolt (3) again can be adopted.
Entity bolt as object of reference, is described technological scheme of the present invention and computational methods in above-mentioned calculating.
Lock bolt (4) effectively tensile elongation L1=B in Fig. 1 embodiment, clamping bolt (3) effectively tensile elongation is Left-wing Federation's fitting (1) thickness.In Fig. 3 embodiment, the effective tensile elongation of lock bolt (4) is the thickness sum of clamping bolt (3) height of head and tightening nut (7), plain cushion (6) and two couplings, and clamping bolt (3) effectively tensile elongation is two coupling thickness sums.The effective tensile elongation of Fig. 5 with Fig. 6 embodiment bolt is identical with Fig. 3 embodiment.The effective tensile elongation of Figure 12 embodiment bolt is identical with Figure 10 embodiment.In Figure 13 embodiment, the effective tensile elongation of lock bolt (4) is the thickness sum of clamping bolt (3) height of head and tightening nut (7), " bowl-type " pad (10) and two couplings, and clamping bolt (3) effectively tensile elongation is two coupling thickness sums.The effective tensile elongation of Figure 14 embodiment bolt is identical with Figure 10 embodiment.In Figure 16 embodiment, the effective tensile elongation of lock bolt (4) is the thickness sum that rigid sleeve (11) length adds tightening nut (7), " bowl-type " pad (10) and two couplings, and clamping bolt (3) effectively tensile elongation is rigid sleeve (11) length and two coupling thickness sums.In Figure 17 embodiment, the effective tensile elongation of lock bolt (4) is the thickness sum of clamping bolt (3) height of head and plain cushion (6) and two couplings, and clamping bolt (3) effectively tensile elongation is right coupling (2) thickness.
Above computational methods are applicable to Fig. 1, Fig. 3, Fig. 5, Fig. 6, Figure 10, Figure 12, Figure 13, Figure 14 and Figure 16 embodiment, if the yield strength of lock bolt (4) or clamping bolt (3) or effectively tensile elongation etc. change, lock bolt (4) diameter range of choice or bolt maximum load-carrying capacity etc. also can change.
If coarse thread selected by clamping bolt (3) or entity bolt, when computing nodes amasss, consider the impact that the degree of depth pair cross-section of screw thread is long-pending, thus the diameter of clamping bolt (3) or entity bolt adopt the footpath, the end of screw thread carry out calculating comparatively reasonable.Because lock bolt (4) diameter is relatively little, the degree of depth of screw thread is less, and the center not drilling of the bolt body of rod, and sectional area does not change, and generally adopts nominal diameter to calculate.
Pretightening force is controlled by screw-down torque, error is about ± and 25%; By nut (or bolt) controlling angle pretightening force, error is about ± and 15%; Pretightening force is controlled by screw-down torque and nut angle relation, accurately higher than press separately screw-down torque or passing through the method for nut (or bolt) controlling angle pretightening force, pretightening force error should be less than ± and 15%.If clamping bolt (3) sticks strain gauge (position is in the scope of the effective tensile elongation of the body of rod) at the inwall of center hole, use resistance strain gage to measure and control pulling force and pretightening force suffered by bolt, after pretightening force needed for arrival, to remove strain gauge and be screwed into lock bolt (4) again, the pretightening force error of clamping bolt (3) is less than ± and 1%.For lock bolt (4), according to measurement extension value inspection pretightening force, pretightening force error is about ± 5%, if direct use dynamometry bolt, pretightening force can be as accurate as kilogram.If clamping bolt (3) or lock bolt (4) use ring washer sensor to control pretightening force, pretightening force error should be less than ± and 15%.If pretightening force error selects ± 15% to carry out calculating and calculated value meets the requirements, the actual error value of bolt pretightening can be controlled in ± 15% within, illustrate that the actual pretightening force of bolt meets the requirements certainly.
If lock bolt (4) the pretightening force F1 that sectional area is less, length is longer gets lower value, comparatively large, that length is shorter clamping bolt (3) the pretightening force F2 of sectional area gets high value, and the maximum pretightening force Fmax of clamping bolt (3) equals pretension total pulling force P.When lock bolt (4) pretightening force F1 increases progressively gradually from lower value to high value, the pretightening force F2 of clamping bolt (3) follows and declines gradually, so lock bolt (4) can regulate clamping bolt (3) pretightening force F2 at any time according to actual conditions, prevent clamping bolt (3) from transshipping, and lock bolt (4) elastic elongation amount is relatively large, be not easy overload.
After the center drilling of clamping bolt (3) body of rod, solve the larger diameter high-strength bolt problem that permeability is poor when heat treatment, bolt is easy through hardening when Quenching Treatment, improve bolt heat treatment effect, energy stabilised quality, be applicable to producing in enormous quantities, and in use without the need to reducing working stress.If diameter 30mm high-strength bolt selected by lock bolt (4), the wall thickness of clamping bolt (3) body of rod gets 30mm, the internal diameter of clamping bolt (3) body of rod center hole gets 31mm, then theoretical maximum diameter (external diameter) Dmax of clamping bolt (3) is 91mm (Dmax=30 × 2+31=91mm), and also can through hardening when Quenching Treatment, steady quality, can use as high-strength bolt, with lock bolt (4) with the use of rear, special occasions can be met and use the high strength needs of larger diameter bolt and locking requirement, compared with use plain bolt, diameter, volume and weight is relatively little, size and the structure of machinery or component can be reduced or be simplified, there is the stronger market competitiveness.
If clamping bolt (3) head sizes is identical with entity bolt, when the material of clamping bolt (3), lock bolt (4) and processing technology etc. are identical with entity bolt, the shear strength of clamping bolt (3) body of rod and head junction should be able to meet the demands.If the material of lock bolt (4) or processing technology are compared with clamping bolt (3) and be there occurs change, when lock bolt (4) yield strength increases or clamping bolt (3) uses larger-diameter high-strength bolt, clamping bolt (3) head thickness and external diameter should suitably increase, ensure that the shear strength of clamping bolt (3) body of rod and head junction is not less than the shearing stress produced when clamping bolt (3) reaches tensile strength, clamping bolt (3) head outer diameter increase is the supporting surface contact stress in order to control clamping bolt (3) head, thermoplastic cyclic pressure falls into prevent the surface of coupling from occurring.
The shear strength of anti-turning nut (9) locking screw and binding thread joint should be not less than clamping bolt (3) and reach produced shearing stress that maximum pretightening force prescribes a time limit, and the compressive strength of locking screw and binding thread joint should be not less than the stress produced when lock bolt (4) reaches tensile strength.
The screw thread of clamping bolt (3) and lock bolt (4) can make by relevant criterion, no matter left-handed or dextrorotation, screw thread does not have cut-off point, does not destroy the intensity of screw thread, is conducive to improving pretightening force and linking intensity.
Above-described embodiment and computational methods are just described technological scheme of the present invention, are not limited to the present invention, every in the scope of technical solution of the present invention, are all shielded right contents.
" two screw retention method " of the present invention is a kind of new method preventing bolt looseness, structure is simple, convenient and practical, anti-turning nut (9) is with now to use the manufacturing process of nut substantially identical, the operation of clamping bolt (3) one body of rod center drilling more than existing bolt, manufacture cost is comparatively cheap, the application area expanding high-strength bolt (mainly refers to there has been stay-in-grade larger diameter high-strength bolt, the existing high-strength bolt of strength ratio is higher, the demand of some special occasions can be met), and there is application repeatability, so the prospect of industrial applicibility is comparatively wide.
Claims (6)
1. this patent relates to a kind of two screw retention method, relate to coupling, bolt, nut, it is characterized in that: processing screw hole or drilling on coupling, lock bolt is different with the external thread diameter of clamping bolt and rotation direction is contrary, the body of rod center drilling of clamping bolt, clamping bolt and fastening screw or tightening nut connect, and lock bolt connects through the center hole of the clamping bolt body of rod and locking screw holes or locking nut, jointly carries out fastening to coupling; Structure that pad and locking nut, tightening nut are welded into " 3 close 1 ", or pad and locking nut are made of one and are welded into " 2-in-1 1 " structure with tightening nut, also handlebar pad and tightening nut are made of one another kind " 2-in-1 1 " structure with locking nut welding, locking nut is different with the internal thread diameter of tightening nut and rotation direction is contrary, clamping bolt connects tightening nut, lock bolt, through the center hole connecting lock jack panel of the clamping bolt body of rod, carries out fastening to coupling jointly; " anti-turning nut " arranges the different and internal thread that rotation direction is contrary of two groups of diameters, and clamping bolt connects " anti-turning nut ", and lock bolt connects " anti-turning nut " through the center hole of the clamping bolt body of rod, jointly carries out fastening to coupling.
2. the two screw retention method of one according to claim 1, is characterized in that: coupling same center of circle longitudinal center line is processed with the different screw contrary with thread rotary orientation of two diameters.
3. the two screw retention method of one according to claim 1, is characterized in that: " anti-turning nut " is thru hole type or hole-sealing structure.
4. the two screw retention method of one according to claim 1, is characterized in that: " anti-turning nut " is " single outer polyhedral angle ", " two outer polyhedral angle " or circle.
5. the two screw retention method of one according to claim 1, is characterized in that: the head of lock bolt or locking nut compress the head of clamping bolt.
6. the two screw retention method of one according to claim 1, it is characterized in that: when bearing work loads, clamping bolt is identical with the elastic elongation amount of lock bolt.
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410152929.6A CN104976210A (en) | 2014-04-11 | 2014-04-11 | Double-bolt anti-loose method |
| PCT/CN2015/074549 WO2015154614A1 (en) | 2014-04-11 | 2015-03-19 | Double-bolt loose proof method |
| CN201580000686.7A CN105452686B (en) | 2014-04-11 | 2015-03-19 | Double screw retention methods |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410152929.6A CN104976210A (en) | 2014-04-11 | 2014-04-11 | Double-bolt anti-loose method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN104976210A true CN104976210A (en) | 2015-10-14 |
Family
ID=54273037
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410152929.6A Pending CN104976210A (en) | 2014-04-11 | 2014-04-11 | Double-bolt anti-loose method |
| CN201580000686.7A Active CN105452686B (en) | 2014-04-11 | 2015-03-19 | Double screw retention methods |
Family Applications After (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201580000686.7A Active CN105452686B (en) | 2014-04-11 | 2015-03-19 | Double screw retention methods |
Country Status (2)
| Country | Link |
|---|---|
| CN (2) | CN104976210A (en) |
| WO (1) | WO2015154614A1 (en) |
Cited By (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107630907A (en) * | 2017-10-25 | 2018-01-26 | 北京临近空间飞行器系统工程研究所 | A kind of derotation self-locking loose-proof thread fastener and its application method |
| CN107725566A (en) * | 2017-11-30 | 2018-02-23 | 张小龙 | Check bolt nut structure assembly |
| CN107939804A (en) * | 2018-01-02 | 2018-04-20 | 福建泉州市金正机械有限公司 | A kind of double rod bolt |
| CN108644215A (en) * | 2018-07-24 | 2018-10-12 | 合肥仨力机械制造有限公司 | A kind of Multifunctional bolt |
| CN108644212A (en) * | 2018-07-24 | 2018-10-12 | 合肥仨力机械制造有限公司 | A kind of screw rod fastener with backing stop structure |
| CN108730307A (en) * | 2018-06-26 | 2018-11-02 | 周焱春 | A kind of bolt connection piece for the connection of house steel plate |
| CN108869502A (en) * | 2018-08-24 | 2018-11-23 | 上海纳特汽车标准件有限公司 | Spot welding is grounded Nut column |
| CN108895080A (en) * | 2018-09-14 | 2018-11-27 | 管铭 | One kind is from torsion stop nut and processing, application method |
| CN109469677A (en) * | 2018-01-29 | 2019-03-15 | 王卫国 | A kind of allosome reducing derotation bolt fastening component of never becoming loose |
| CN109963511A (en) * | 2016-10-25 | 2019-07-02 | 李志强 | The artificial dental implant system of mechanism is locked and fetched with positive pillar screw |
| CN110107575A (en) * | 2019-05-30 | 2019-08-09 | 河北鑫泰轴承锻造有限公司 | A kind of primary and secondary setscrew component |
| CN111536131A (en) * | 2020-05-12 | 2020-08-14 | 三一重机有限公司 | Bolt locking structure |
| CN113297711A (en) * | 2021-07-28 | 2021-08-24 | 广东电网有限责任公司中山供电局 | Structure optimization method and device for passive loosening early warning bolt |
| CN114321137A (en) * | 2021-11-20 | 2022-04-12 | 杨富云 | Method for improving anti-loosening performance of thread pair and auxiliary spring pad thereof |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107356179B (en) * | 2017-08-21 | 2023-07-11 | 贵州航太精密制造有限公司 | Three-needle measurement fixing device |
| CN112699499B (en) * | 2020-11-09 | 2022-09-20 | 东风汽车集团有限公司 | Gasoline engine flywheel bolt type selection and check method |
| CN112528394B (en) * | 2020-11-09 | 2022-04-15 | 东风汽车集团有限公司 | Automobile engine connecting rod bolt type selection and checking method |
| CN113021260B (en) * | 2021-03-18 | 2022-10-28 | 上汽大众汽车有限公司 | Device for dismounting bolt by vehicle broach block |
| CN114909382B (en) * | 2022-04-27 | 2024-04-12 | 江苏联储能源科技有限公司 | Nut anti-loosening structure for high-temperature molten salt pump and installation method of nut anti-loosening structure |
| CN115076205A (en) * | 2022-06-22 | 2022-09-20 | 东方电气风电股份有限公司 | Novel bolt anti-loosening method applied to oil immersion environment of wind generating set |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US904956A (en) * | 1907-08-30 | 1908-11-24 | Don J Higginbotham | Nut-lock. |
| US2066402A (en) * | 1935-06-01 | 1937-01-05 | Daniel W Hinkel | Electrical system |
| US3772503A (en) * | 1972-11-22 | 1973-11-13 | Laitram Corp | Course difference logic for use with digital magnetic compass |
| JPS501769U (en) * | 1973-05-04 | 1975-01-09 | ||
| JP2767683B2 (en) * | 1994-02-16 | 1998-06-18 | 吉之助 長塩 | Vibration resistant screw |
| CN2893281Y (en) * | 2005-12-15 | 2007-04-25 | 董金 | Double-thread self-locking screwbolt and nut |
| WO2012070272A1 (en) * | 2010-11-25 | 2012-05-31 | 株式会社ハマ・システム | Bolt |
| TW201239210A (en) * | 2011-03-31 | 2012-10-01 | Hon Hai Prec Ind Co Ltd | Screwing connection assembly |
| CN102506048A (en) * | 2011-08-05 | 2012-06-20 | 王大俊 | Anti-loosing clamping bolt set |
| CN202338550U (en) * | 2011-11-17 | 2012-07-18 | 中铁十五局集团有限公司 | Pull type self-locking bolt |
-
2014
- 2014-04-11 CN CN201410152929.6A patent/CN104976210A/en active Pending
-
2015
- 2015-03-19 CN CN201580000686.7A patent/CN105452686B/en active Active
- 2015-03-19 WO PCT/CN2015/074549 patent/WO2015154614A1/en active Application Filing
Cited By (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109963511A (en) * | 2016-10-25 | 2019-07-02 | 李志强 | The artificial dental implant system of mechanism is locked and fetched with positive pillar screw |
| CN107630907A (en) * | 2017-10-25 | 2018-01-26 | 北京临近空间飞行器系统工程研究所 | A kind of derotation self-locking loose-proof thread fastener and its application method |
| CN107725566A (en) * | 2017-11-30 | 2018-02-23 | 张小龙 | Check bolt nut structure assembly |
| CN107939804A (en) * | 2018-01-02 | 2018-04-20 | 福建泉州市金正机械有限公司 | A kind of double rod bolt |
| CN109469677A (en) * | 2018-01-29 | 2019-03-15 | 王卫国 | A kind of allosome reducing derotation bolt fastening component of never becoming loose |
| CN108730307B (en) * | 2018-06-26 | 2019-12-10 | 广州总力金属制品有限公司 | Bolt connecting piece for connecting house steel plates |
| CN108730307A (en) * | 2018-06-26 | 2018-11-02 | 周焱春 | A kind of bolt connection piece for the connection of house steel plate |
| CN108644215A (en) * | 2018-07-24 | 2018-10-12 | 合肥仨力机械制造有限公司 | A kind of Multifunctional bolt |
| CN108644212A (en) * | 2018-07-24 | 2018-10-12 | 合肥仨力机械制造有限公司 | A kind of screw rod fastener with backing stop structure |
| CN108869502A (en) * | 2018-08-24 | 2018-11-23 | 上海纳特汽车标准件有限公司 | Spot welding is grounded Nut column |
| CN108895080A (en) * | 2018-09-14 | 2018-11-27 | 管铭 | One kind is from torsion stop nut and processing, application method |
| CN110107575A (en) * | 2019-05-30 | 2019-08-09 | 河北鑫泰轴承锻造有限公司 | A kind of primary and secondary setscrew component |
| CN111536131A (en) * | 2020-05-12 | 2020-08-14 | 三一重机有限公司 | Bolt locking structure |
| CN113297711A (en) * | 2021-07-28 | 2021-08-24 | 广东电网有限责任公司中山供电局 | Structure optimization method and device for passive loosening early warning bolt |
| CN114321137A (en) * | 2021-11-20 | 2022-04-12 | 杨富云 | Method for improving anti-loosening performance of thread pair and auxiliary spring pad thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2015154614A1 (en) | 2015-10-15 |
| CN105452686A (en) | 2016-03-30 |
| CN105452686B (en) | 2018-06-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104976210A (en) | Double-bolt anti-loose method | |
| CN101915261B (en) | Advanced nut and bolt | |
| US4603889A (en) | Differential pitch threaded fastener, and assembly | |
| US4346920A (en) | Threaded connection using variable lead threads | |
| US7735879B2 (en) | Sucker rod connection with improved fatigue resistance, formed by applying diametrical interference to reduce axial interference | |
| CN108457960A (en) | Tapered importing for Interference-fit fasteners | |
| CN104963927A (en) | Flanging and riveting self-locking nut and machining method thereof | |
| US20170321826A1 (en) | Single lead wedgethread connection | |
| JP2011012784A (en) | Method for manufacturing fastener, bolt and nut, and method for fastening fastener | |
| CN209800516U (en) | Accurate moment control type locknut | |
| US20200032832A1 (en) | Improvements in or Relating to Screwbolts | |
| EP1886031A2 (en) | Fastener and method for reducing stress failure in an engine component | |
| CN201836190U (en) | High-strength hexagon-flange-faced self-lubricating torsional bolt connection set | |
| CN101463830A (en) | Shaft coupling structure of impeller pump | |
| EP2688713B1 (en) | Torque-angle structural fastening system | |
| US20220016750A1 (en) | Torque-angle structural fastening system | |
| CN210565657U (en) | Anti-loose fastening device for nut | |
| NO20150217A1 (en) | Threaded connector | |
| CN109944326B (en) | Connecting node of self-compaction wedge-shaped split type pressure-bearing high-strength bolt | |
| CN219597678U (en) | Composite roller device | |
| CN113216522B (en) | Steel bar connecting method | |
| CN2846715Y (en) | Screw joint for downhole tool external tube part of petroleum drill well | |
| CN202624362U (en) | Novel steering pull rod connecting device | |
| CN209838895U (en) | Concrete bolt | |
| CN107090917A (en) | A kind of assembled space nodes applied to aluminium alloy aperture structure |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20151014 |
|
| WD01 | Invention patent application deemed withdrawn after publication |