CN109657381A - A kind of check method of screw thread tripping - Google Patents
A kind of check method of screw thread tripping Download PDFInfo
- Publication number
- CN109657381A CN109657381A CN201811596885.0A CN201811596885A CN109657381A CN 109657381 A CN109657381 A CN 109657381A CN 201811596885 A CN201811596885 A CN 201811596885A CN 109657381 A CN109657381 A CN 109657381A
- Authority
- CN
- China
- Prior art keywords
- screw thread
- internal
- length
- thread
- tripping
- 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.)
- Withdrawn
Links
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/10—Geometric CAD
- G06F30/17—Mechanical parametric or variational design
Landscapes
- Physics & Mathematics (AREA)
- Geometry (AREA)
- Engineering & Computer Science (AREA)
- Theoretical Computer Science (AREA)
- General Physics & Mathematics (AREA)
- Pure & Applied Mathematics (AREA)
- Mathematical Optimization (AREA)
- Mathematical Analysis (AREA)
- Computer Hardware Design (AREA)
- Evolutionary Computation (AREA)
- General Engineering & Computer Science (AREA)
- Computational Mathematics (AREA)
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
Abstract
The present invention provides a kind of check method of internal and external threads tripping, and the check to tripping is realized by the comparison to screw thread seat length and minimum length of action.Using this method, by measurement screw thread seat length and screw thread minimum length of action directly can be calculated, accurately obtain check result.To play more accurate directive function to design, bring loss of threading off because of screw thread is avoided.Any kind of thread connection in practical applications, if screw thread tripping can be determined according to this method by checking length of action.
Description
Technical field
The present invention relates to mechanical engineering technical field more particularly to a kind of check methods of screw thread class connection screw thread tripping.
Background technique
When the pulling force born when one group of internal and external threads connection is secondary is excessive, connection parts are it is possible that several failures below
Form:
External thread piece fracture --- such case generation is enough in length of thread engagement (LE), and the comparable feelings of internal and external threads intensity
Condition.
External screw thread tripping --- tripping refers to the excessive deformation of screw thread, and such case generation is inadequate in length of action, and interior spiral shell
The bigger situation of grain material intensity.
Internal screw thread tripping --- such case generation is inadequate in length of action, and the situation that external screw thread intensity is bigger.
The first failure mode: external screw thread fracture, is preferred failure mode, because this failure mode can be quick
The problem of identifying, being conducive to early stage identification, to be solved the problems, such as with the smallest time human cost.And latter two failure mode:
External screw thread tripping and internal screw thread tripping, are difficult to detect before factory, once there is the product export of this failure into client's hand,
There is a high likelihood that more serious failure occurs in the use process of client.Therefore, the design phase, to consider cannot be outside
There is the case where internal and external threads tripping before screw element fracture.
Currently, general main engine plants, which carry out the method that screw thread tripping is checked, is all based on empirical equation or coefficient figure, according to interior
Thread material and bolt grade approximate evaluation are difficult to ensure the validity and accuracy of specific or special connection situation assessment.
Summary of the invention
To solve the above problems, the present invention provides a kind of check method of internal and external threads tripping, by nibbling to screw thread is practical
Close check of the comparison realization of length and minimum length of action to tripping.Specifically comprise the following steps:
(1) measurement need to check the seat length L of screw thread1；
(2) according to thread parameter, internal and external threads relative intensity J is determinedmod；
(3) according to internal and external threads relative intensity, internal and external threads minimum length of action Le is obtained；
(4) the minimum length of action that the seat length and step (3) that comparison step (1) measurement obtains obtain, judgement
Check whether screw thread can thread off.
Further, the seat length is the length that internal and external threads completely engage, and does not include that external screw thread tail portion is fallen
The length of angle or internal screw thread countersunk head chamfering.
Further, internal and external threads relative intensity is obtained by following formula:
Wherein:
τb--- external screw thread shear strength；
τn--- internal screw thread shear strength；
ASS--- the minimum section of shear of one thread of external screw thread
d2min--- pitch diameter of external thread minimum value；
D1max--- internal screw thread path maximum value；
P --- screw pitch；
ASn--- the minimum section of shear of one thread of internal screw thread
dmin--- external screw thread major diameter minimum value；
D2max--- thread pitch diameter maximum value.
Further, the step (3) especially by following formula obtain:
Work as JmodWhen≤1, minimum length of action Le:
Work as JmodWhen > 1, minimum length of action Le:
Wherein:
Rm--- external screw thread tensile strength；
AS--- external screw thread nominal stress area
D --- external screw thread major diameter；
C --- internal and external threads expansion strength coefficient；
S --- the equivalent across flats of inner thread piece；
D --- internal screw thread major diameter.
Further, seat length L1Compared with carrying out as follows with minimum length of action Le, check result is obtained:
L1Screw thread tripping will not occur for >=Le；
L1< Le, it may occur that screw thread tripping.
Further, non-ferrous casting, minimum length of action increase 2P on the basis of the above calculated result；For hair
Motivation couples key position, and minimum length of action increases 3P on the basis of the above calculated result.
It based on above-mentioned measurement, calculates and compares, by unique indication that length of thread engagement (LE) is threaded off as screw thread, determine special
Whether fixed connection structure can occur screw thread tripping.
The beneficial effects of the present invention are: compared with conventional method, applicability is wider, and check result is more acurrate, traditional coefficient
Figure or empirical value, often just for specific different materials, and actual conditions are that material category is various, and mechanics parameter difference is bright
It is aobvious, check result can only be obtained by approximate mode, using this method, can directly pass through input mechanics parameter and structure ginseng
Number, accurately obtains check result.To play more accurate directive function to design, bring damage of threading off because of screw thread is avoided
It loses.
Detailed description of the invention
Fig. 1 present invention checks flow chart.
Specific embodiment
Below in conjunction with attached drawing and specific embodiment, specific implementation method of the invention is described in detail.
The embodiment of the present invention is that certain vehicle motor bell housing couples with speed change box clutch shell, and wherein bell housing was
Hole, clutch housing are had internal screw thread, are coupled using hexagonal flange hook bolt with internal screw thread.Dimension of inner screw thread is M10x25-6H,
Clutch housing basis material is HT250, according to " 9439 gray iron casting of GB/T ", tensile strength sigman=250MPa.Bolt sizes
For M10x1.5x35-6g, material SCM435, performance rate is 10.9 grades, according to " 3098.1 fastener mechanical performance of GB/T
Bolt, screw and stud ", tensile strength Rm=1040MPa.
(1) measurement flywheel shell of engine thickness of shell is 12.7mm, and internal screw thread counterbore chamfering 2mm, bolt chamfering is 3mm.
Therefore practical internal and external threads length of action are as follows: 35-12.7-2-3=17.3mm.
(2) according to " GB/T 15756-2008 regular screw threads dimension limit ", by d2min=8.862mm, D1max=
8.676mm P=1.5mm is substituted into
It can obtain: ASS=23.37mm2
According to " GB/T 15756-2008 regular screw threads dimension limit ", by dmin=9.732mm, D2max=9.206mm, P
In=1.5mm substitution
It can obtain: ASn=32.22mm2
According to " system-computed of 2230 high-strength bolt of VDI " table 5.5/2: τb=0.62Rm
According to " system-computed of 2230 high-strength bolt of VDI " table 5.5/1: τn=1.4 σn
By ASS=23.37mm2, ASn=32.22mm2, Rm=1040MPa, σn=250MPa is substituted into
Above formula can obtain: Jmod=1.28 > 1
Jmod> 1, illustrate that occurring thread stripping at first is internal screw thread.
(3) gaging clutch shell and bell housing contact surface inscribed hexagon opposite side distance s=15mm, according to " GB/T
196 regular screw threads basic sizes ", D=10mm is substituted intoC=0.84 can be obtained.
According to " 196 regular screw threads basic size of GB/T ", d=10mm substitutes into following formula
: AS=57.99mm2
Again by AS=57.99mm2, ASn=32.22mm2, Rm=1040MPa, τn=1.4 σn=350MPa substitutes into formula:
: Le=9.55mm
(4) embodiment of the present invention, coupled position are engine key position, therefore on the basis of the above calculated result,
It is further added by 3P, as final minimum length of action:
Le'=Le+ 3P=9.55+3 × 1=12.55mm < 17.3mm
Design length of action is met the requirements, and screw thread tripping will not occur.
Any kind of thread connection in practical applications, if screw thread tripping can be according to this method by checking engagement
Length is determined.
Claims (6)
1. a kind of check method of screw thread tripping, characterized by the following steps:
(1) measurement need to check the seat length L of screw thread1；
(2) according to thread parameter, internal and external threads relative intensity J is determinedmod；
(3) according to internal and external threads relative intensity Jmod, obtain internal and external threads minimum length of action Le；
(4) the minimum length of action that the seat length and step (3) that comparison step (1) measurement obtains obtain, judges to check
Whether screw thread can thread off.
2. a kind of check method of screw thread tripping according to claim 1, it is characterised in that: the seat length is
The length that internal and external threads completely engage does not include the length of external screw thread tail portion chamfering or internal screw thread countersunk head chamfering.
3. a kind of check method of screw thread tripping according to claim 1, it is characterised in that: internal and external threads relative intensity,
It is obtained by following formula:
Wherein:
τb--- external screw thread shear strength；
τn--- internal screw thread shear strength；
ASS--- the minimum section of shear of one thread of external screw thread
d2min--- pitch diameter of external thread minimum value；
D1max--- internal screw thread path maximum value；
P --- screw pitch；
ASn--- the minimum section of shear of one thread of internal screw thread
dmin--- external screw thread major diameter minimum value；
D2max--- thread pitch diameter maximum value.
4. a kind of check method of screw thread tripping according to claim 3, it is characterised in that: the step (3) it is specific
It is obtained by following formula:
Work as JmodWhen≤1, minimum length of action Le:
Work as JmodWhen > 1, minimum length of action Le:
Wherein:
Rm--- external screw thread tensile strength；
AS--- external screw thread nominal stress area
D --- external screw thread major diameter；
C --- internal and external threads expansion strength coefficient；
S --- the equivalent across flats of inner thread piece；
D --- internal screw thread major diameter.
5. a kind of check method of screw thread tripping according to claim 4, it is characterised in that: seat length L1With most
Small length of action Le is compared as follows, obtains check result:
L1Screw thread tripping will not occur for >=Le；
L1< Le, it may occur that screw thread tripping.
6. a kind of check method of screw thread tripping according to claim 4, it is characterised in that: non-ferrous casting, it is minimum
Length of action increases 2P on the basis of the above calculated result；For engine couple key position, minimum length of action with
Increase 3P on the basis of upper calculated result.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811596885.0A CN109657381A (en) | 2018-12-26 | 2018-12-26 | A kind of check method of screw thread tripping |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811596885.0A CN109657381A (en) | 2018-12-26 | 2018-12-26 | A kind of check method of screw thread tripping |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN109657381A true CN109657381A (en) | 2019-04-19 |
Family
ID=66115178
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811596885.0A Withdrawn CN109657381A (en) | 2018-12-26 | 2018-12-26 | A kind of check method of screw thread tripping |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109657381A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116955894A (en) * | 2023-09-20 | 2023-10-27 | 肇庆星诺奇传动科技有限公司 | Online self-adaptive thread length information calibration method and system |
-
2018
- 2018-12-26 CN CN201811596885.0A patent/CN109657381A/en not_active Withdrawn
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116955894A (en) * | 2023-09-20 | 2023-10-27 | 肇庆星诺奇传动科技有限公司 | Online self-adaptive thread length information calibration method and system |
| CN116955894B (en) * | 2023-09-20 | 2024-01-09 | 肇庆星诺奇传动科技有限公司 | Online self-adaptive thread length information calibration method and system |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Ham et al. | Forming limit curves in single point incremental forming | |
| WO2007089760A3 (en) | Thread forming fasteners for ultrasonic load measurement and control | |
| US6851167B2 (en) | Method for installing blind threaded inserts | |
| Roy et al. | Multiaxial fatigue behaviour of A356‐T6 | |
| WO2005123344A1 (en) | System and method for automated execution of bolted joints | |
| US20140335345A1 (en) | Corrosion-resistant screw, use of a screw of this type in a corrosive environment, and method for the fabrication of a screw of this type | |
| CN109657381A (en) | A kind of check method of screw thread tripping | |
| EP2638989A1 (en) | Process for manufacture of fastening component made from aluminum-based alloy, and fastening component made from aluminum-based alloy | |
| CN107110191A (en) | Method for installing the firm fastener of self-locking | |
| Wagner et al. | Experimental analysis of damage propagation in riveted CFRP-steel structures by thermal loads | |
| Zeng et al. | Influence of initial fit tolerance and squeeze force on the residual stress in a riveted lap joint | |
| Ebert et al. | Behaviour of lockbolts in slip‐resistant connections for steel structures | |
| WO2018193937A1 (en) | Rivet nut and manufacturing method therefor | |
| CN100404891C (en) | Connection rod for internal combustion engine | |
| CN105378303A (en) | Screw component | |
| Neely | Correlation of stress intensity range with deviation of the crack front from the primary crack plane in both hand and die forged aluminum 7085-T7452 | |
| Aktas et al. | Effects of thread rolling processing parameters on mechanical properties and microstructures of high-strength bolts | |
| Zhuang et al. | Analysis of sheet metal extrusion process using finite element method | |
| JP5396089B2 (en) | Hot forged stainless nut | |
| Haris et al. | Analysis of crack deffect at Nut M 14 cold forging process with FTA methode | |
| JP6025653B2 (en) | Bolt for tightening characteristic evaluation and manufacturing method thereof | |
| LU504608B1 (en) | A method for determining the tightness of high-strength bolts in wind turbines | |
| Crane | Aviation mechanic handbook | |
| CN212410259U (en) | Clamp assembly for bolt failure torque measurement | |
| CN101915257A (en) | Safety evaluation method for preventing delayed fracture of high strength bolt below M100mm |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WW01 | Invention patent application withdrawn after publication | ||
| WW01 | Invention patent application withdrawn after publication |
Application publication date: 20190419 |