CN1959340A - Method for measuring median diameter of tap with odd slots by using length measuring instrument - Google Patents

Abstract

A method for measuring pitch diameter of odd slot tap by length meter includes calibrating instrument by standard bar, selecting measurement needle being placed in alveolus of odd slot tap, moving measurement rod to let measurement cap contact with measurement needle, rotating odd slot tap and fetching maximum value N on digital display box then obtaining pitch diameter of tap by calculation.

Description

Measure the method in footpath in the tap with odd slots with horizontal metroscope

Technical field

Type of the present invention relates to a kind of surveying instrument, is specifically related to a kind of method of measuring footpath in the tap with odd slots with horizontal metroscope.

Background technology

Therefore the pitch diameter of thread often needs to measure footpath in the screw tap, to guarantee the thread quality and the precision of product to be processed as the important parameter of screw tap product in commercial production.Usually measure and directly adopt horizontal length measuring machine in the cylindrical thread screw tap.Horizontal length measuring machine is a kind of length-measuring instrument that is combined by precision optical machinery, optical system and electric part, is mainly used in the measurement, cylindrical external thread of measurement, hole measuring, the cylindrical component of measurement, the bulb of parallel plane part that the footpath is measured, the footpath is measured etc. in the internal thread.It is measured, and the footpath measuring method is in the cylindrical external thread: referring to Fig. 5, two thimbles 3 of tested screw tap horizontal length measuring machine are fixed on the worktable, with surveying cap 43 metering pins 1 are abutted against in the groove on the form of thread,, calculate the pitch diameter of thread with formula again by digital display case sense data.The advantage of horizontal metroscope is the measuring accuracy height, is to measure the gauging instrument that the footpath is the most frequently used in the cylindrical external thread, precision is higher at present.Ginseng Fig. 6 and since each land of tap with odd slots pairing be groove, adopt said method metering pin can not be abutted against in the groove on the screw tap form of thread, with horizontal survey long only not in the energy measurement tap with odd slots directly.

Measure the method in footpath in the tap with odd slots at present, have following two kinds: 1. with three ditch screw tap somascopes measure footpath in the tap with odd slots (referring to Heilongjiang Province's standard metering management board and Harbin Institute of Technology write " the length metering handbook), this method is a comparative measurement method, promptly use with tested tap with odd slots in the footpath, the identical size with the thread form angle of pitch is also adjusted this measurement mechanism by footpath in the reality of standard screw thread gauge of calibrating, and then tap with odd slots compared measurement, measuring accuracy is low, is applicable in enormous quantities, the low tap with odd slots of accuracy requirement is measured; 2. utilizing thimble, measurement cutter and the combination of optics index sleeve to measure footpath in the tap with odd slots on universal tool-measuring microscope (publish referring to China Machine Press, " the universal tool-measuring microscope modus operandi " that Xu Xiaoen writes), in measuring process, screw tap workpiece of every measurement, in data handling procedure, must consider screw tap rotation θ angle, the compensation of the groove error of division and the data such as compensation of helix angle, therefore this measuring method is loaded down with trivial details, complicated, efficient is low, and the tap with odd slots that is only applicable to short run is measured.Therefore how measuring the middle footpath of tap with odd slots quickly and accurately, is a current problem that needs solution.

Summary of the invention

The purpose of this invention is to provide and a kind ofly measure the method in footpath in the tap with odd slots, adopt conventional horizontal length measuring machine, can measure footpath in the tap with odd slots of all size, and have measurement result accurate, measure fast, the simple advantage of method of operating with horizontal metroscope.

The object of the present invention is achieved like this:

Master bar is placed on the thimble support of horizontal metroscope, clamps with two thimbles, metering pin 1 is suspended on the measuring staff support that is connected to, and moves and surveys seat and measuring staff, and the survey cap is contacted with master bar, adjusts four and adjusts screw, and floating work bench is fixed;

Adjusting the survey cap makes it parallel with master bar;

Half of the value Φ of master bar calibrating is defined as initial value, and instrument is adjusted;

Metering pin is selected in system of selection with the metering pin of routine;

Tap with odd slots is installed on the thimble support and clamps with two thimbles, and a metering pin 1 of choosing is placed in the alveolus of tap with odd slots mobile measuring staff, the survey cap is contacted with metering pin, rotate tap with odd slots, on the digital display case, read maximal value N, calculate footpath in the screw tap by following formula

$d_2=2N-d_0(1+\frac{1}{\sin \mathrm{\α}/2})+\frac{p}{2}\mathrm{ctg}\frac{\mathrm{\α}}{2}$

In the formula: d ₂Be footpath in the tap with odd slots, N is the measured value that shows on the digital display case, d ₀Be the metering pin diameter, α is a tap with odd slots thread form angle, and P is a screw tap pitch;

Measure in several directions respectively with said method, calculate mean value at last and be defined as footpath in this screw tap.

Adopted such scheme, when footpath in the tap with odd slots was measured, the left and right end margin of floating work bench laid respectively in the breach of baffle plate, screws with the adjustment screw, and floating work bench can not left and rightly be floated and rotation.The thimble support is fixed on the floating work bench top by the spiral shell inspection, and two thimbles clamp tap with odd slots.Method with footpath in the horizontal length measuring machine measurement cylindrical external thread during measurement combines with the single needle mensuration, do not need standard screw thread gauge just can measure to footpath in the tap with odd slots, can measure footpath in the tap with odd slots with a metering pin, therefore, measuring method is simple, can be used for tap with odd slots in enormous quantities and measure, and the accuracy of detection height.

The present invention can be used for measuring the middle footpath of the tap with odd slots of all size.

Cost of the present invention is low, high efficiency, and measuring in the tap with odd slots footpath only needs 0.5 minute, and uncertainty of measurement is 0.0024mm, can satisfy the measurement to all size, in enormous quantities, tap with odd slots that accuracy requirement is high.

The present invention can be used for the horizontal length measuring machine of various models, all can reach effect of the present invention.

The invention will be further described below in conjunction with the drawings and the specific embodiments.

Description of drawings

Fig. 1 is a structural representation of the present invention;

Fig. 2 is the A portion cutaway view Amplified image of Fig. 1;

Fig. 3 is that the B of Fig. 1 is to view;

Fig. 4 is for measuring the synoptic diagram in footpath in the tap with odd slots;

Fig. 5 is a footpath instrumentation plan in the cylindrical external thread;

Fig. 6 is the structure diagram of tap with odd slots.

In the accompanying drawing: 1 is metering pin, and 2 is tap with odd slots, and 3 is thimble, and 4 for surveying cap, and 5 is master bar, and 6 is baffle plate, 7 for adjusting screw, and 8 is floating work bench, and 9 is the thimble support, and 10 is worktable, and 11 is screw, 12 is base, and 13 for surveying seat, and 14 is the digital display case, and 15 is measuring staff, and 16 is breach.

Embodiment

With reference to Fig. 1, survey seat 13 in the horizontal length measuring machine and be slidingly fitted on the guide rail of base 12, and be positioned at any position on the guide rail by revolving hand.Measuring staff 15 clearance fit are in surveying seat 13, and the grating chi is fixed in the measuring staff 15, and the stroke value of measuring staff axially-movable transfers signals in the digital display case 14 by the sensor-based system of grating chi, carry out electronic fine-grained, counting and show numerical value with charactron.Survey cap 4 usefulness bolt tightenings and cooperate the end that is installed in measuring staff 15, the bracket clamp that hangs metering pin is connected on the front end of measuring staff 15, and metering pin 1 is suspended on the place ahead of surveying cap by support.

Worktable 10 cooperations of horizontal length measuring machine are installed on the base 12, with revolving any position that hand is positioned at base, according to the method adjustment in the instrument operation instructions, make worktable can do 0～105mm lifting.Left and right two end faces at worktable 10 are fixed (referring to Fig. 2) with screw 11 and baffle plate 6 respectively, the top of baffle plate is provided with breach 16, described indentation, there is provided with screw, the screw of the breach on two baffle plate tops is two, perhaps the screw of the breach on one of them baffle plate top is two, and the screw of the breach on another baffle plate top is one.Floating work bench 8 is movably connected in the upper surface of worktable 10, and its relative worktable can be done moving horizontally of positive and negative 5mm, and rotates positive and negative 4 ° around table axis.The left and right end margin of floating work bench 8 lays respectively in the breach of baffle plate, between floating work bench edge and the baffle plate breach spacing distance that is not less than 3mm is arranged.4 or 3 adjust on the threaded hole that screw 7 is installed in baffle plate 6 breach and screw, and floating work bench can not left and rightly be floated and rotation.Thimble support 9 is by being bolted to floating work bench 8 tops, and two thimbles 3 that are provided with in opposite directions on the thimble support 9 are positioned on the same axial line, and two thimbles clamp tap with odd slots 2.

With reference to Fig. 1,3 and Fig. 4, the present invention measures the process in footpath in the tap with odd slots:

Master bar is a right cylinder, and its two ends are respectively arranged with centre hole, and described centre hole matches with thimble on the horizontal metroscope.Master bar is made of high-quality tool steel, and quenching hardness is HRC56～62.The master bar surface roughness Ra is 0.1, and the right alignment of the relative centre hole of master bar cylindrical is 0.001, and cylindricity is 0.002, and the diameter of master bar is identified with the above gauge block of the fourth class.The effect of master bar is to determine the initial value of horizontal metroscope and determine to measure axis and measured axis normal.

Master bar 5 is placed on the thimble support and clamps with two thimbles.Metering pin 1 is suspended on the support that is connected to measuring staff, move and survey seat 13 and measuring staff 15, survey cap 4 is contacted with master bar 5, adjust four and adjust screw 7, look for " turning point " according to the method in the horizontal metroscope operation instructions, make survey cap 4 parallel with master bar 5, because surveying cap 4 is mounted on the end face of measuring staff 15, and with measuring staff 15 motions, survey cap 4 and measuring staff 15 and inner grating chi composition slotted line, so when the axis normal of surveying cap 4 and master bar 5 explanation measurement axis X and master bar 5 when parallel, then measure the axis normal of axis X and master bar 5, it is vertical with measured axis Y promptly to measure axis X.Half determines initial value to get it according to the certified value Φ (being assumed to be Φ 20.003mm) of master bar 5 then, and promptly the numerical value that shows of digital display case 14 equals the master bar certified value

(being assumed to be 10.0015mm).

After instrument is adjusted, select metering pin 1 according to metering pin computing formula (1) earlier.

$d_0=\frac{p}{2\cos \mathrm{\α}/2}---\left(1\right)$

In the formula: d ₀For metering pin diameter P is the thread form angle for pitch α

Tap with odd slots is installed on the thimble support and clamps with two thimbles, a metering pin 1 of choosing is placed in the alveolus of tap with odd slots 2, mobile measuring staff 15, survey cap 4 is contacted with metering pin 1, rotate tap with odd slots 2, on digital display case 14, read maximal value N, calculate footpath in the screw tap by formula (2).

$d_2=2N-d_0(1+\frac{1}{\sin \mathrm{\α}/2})+\frac{p}{2}\mathrm{ctg}\frac{\mathrm{\α}}{2}---\left(2\right)$

In the formula: d ₂Be footpath in the tap with odd slots; N is the measured value that shows on the digital display case, and promptly N is the distance of tap with odd slots axial line to metering pin; d ₀Be the metering pin diameter; α is a tap with odd slots thread form angle; P is a screw tap pitch.

In order to improve measuring accuracy, measure in several directions respectively, to eliminate the morpheme error of product, calculate mean value at last and be defined as footpath in this screw tap.

Several grooves are arranged usually, then should measure, should measure at three cutting edge places, calculate mean value then, calculate footpath in the tap with odd slots by formula (2) as the three-flute screw tap at several cutting edges place of screw tap.

Example: be that the footpath is measured in the tap with odd slots of M 3.5 * 0.35-6H to specification.Technical requirement is: pitch P=0.35 ± 0.008, thread form half-angle α/2=30 ° ± 25 ', middle footpath d ₂=3.32 _-0.014

At first instrument is adjusted, made measured axial connecting line and measure axis normal.

Aligning of initial value makes the numerical value in the reading microscope equal 1/2 of master bar certified value, and the master bar certified value is 20.003mm, and then the numerical value in the reading microscope is 10.0015mm.

According to formula $d_0=\frac{p}{2\cos (\mathrm{\α}/2)}$ (P: pitch, α: the thread form angle), the best metering pin of selection is 0.201mm, the numerical value in the reading microscope is N ₁=1.808, N ₂=1.807, N ₃=1.809, mean value N=1.808mm.

According to formula $d_2=2N-d_0(1+\frac{1}{\sin \mathrm{\α}/2})+\frac{p}{2}\mathrm{ctg}\frac{\mathrm{\α}}{2},$ Obtain the middle footpath value d of three-flute screw tap ₂=3.316mm.The middle footpath value of the three-flute screw tap that records is d ₂=3.316mm meets footpath d in the three-flute screw tap of WC4101 product ₂=3.32 _-0.014Error requirements, therefore the footpath is qualified in the tested three-flute screw tap.

Claims (1)

1. measure the method in footpath in the tap with odd slots with horizontal metroscope for one kind, it is characterized in that may further comprise the steps:

Master bar is placed on the thimble support of horizontal metroscope, clamps with two thimbles, metering pin 1 is suspended on the measuring staff support that is connected to, and moves and surveys seat and measuring staff, and the survey cap is contacted with master bar, adjusts four and adjusts screw, and floating work bench is fixed;

Adjusting the survey cap makes it parallel with master bar;

Half of the value Φ of master bar calibrating is defined as initial value, and instrument is adjusted;

Metering pin is selected in metering pin system of selection with routine;

Tap with odd slots is installed on the thimble support and clamps with two thimbles, and a metering pin 1 of choosing is placed in the alveolus of tap with odd slots mobile measuring staff, the survey cap is contacted with metering pin, rotate tap with odd slots, on the digital display case, read maximal value N, calculate footpath in the screw tap by following formula

$d_2=2N-d_0(1+\frac{1}{\sin \mathrm{\α}/2})+\frac{p}{2}\mathrm{ctg}\frac{\mathrm{\α}}{2}$

In the formula: d ₂Be footpath in the tap with odd slots, N is the measured value that shows on the digital display case, d ₀Be the metering pin diameter, α is a tap with odd slots thread form angle, and P is a screw tap pitch.

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