CN102773808B - Optimization method for topography of soldering diamond-impregnated grinding wheel of high-speed railway track plate - Google Patents

Abstract

The invention belongs to the field of manufacturing a high-speed railway track plate grinding wheel, in particular to an optimization method for topography of a soldering diamond-impregnated grinding wheel of a high-speed railway track plate. The optimization method comprises the steps: according to the mechanism of removing materials by the diamond of the revolving grinding wheel, carrying out mathematical analysis on the grinding process of single-layer diamond-soldered grinding wheel by combining grinding parameters so as to determine the optimal abrasive topography on the surface of the grinding wheel; adopting segmental distribution to the abrasive on the surface of the grinding wheel, wherein the optimal number of segments is larger than or equal to 65, the width of a chip groove of each segment is larger than 7.2mm, and the optimal area of the included angle between the each segment material distribution area and the vertical plane ranges from 55 degrees to 65 degrees. The optimization method determines the optimal topography of the soldering diamond-impregnated grinding wheel of the high-speed railway track plate, thereby playing optimal grinding performance of the soldering diamond-impregnated grinding wheel.

Description

High-speed rail plate braze welding diamond emery wheel landforms optimization method

Technical field

The invention belongs to high-speed rail plate emery wheel and manufacture field, relate to a kind of high-speed rail plate braze welding diamond emery wheel landforms optimization method, be applicable to abrasive material arrangement and the optimization of single layer soldering super hard abrasive rotary type instrument.

Background technology

China greatly develops high-speed railway at present, and current speed per hour has reached 350 kilometers.For ensureing the ride comfort of track circuit, stability and security, the rail of China Express Railway is not be laid on common sleeper, but is laid on the track plates-rich lattice plate of accurately polishing through lathe.Rich lattice plate is invented by German Bo Ge company, and China Express Railway technology all adopts this ballastless track structure type to win lattice plate.It is a block length 6.45 meters, high 20 centimetres, weigh high strength, the high-compactness concrete track of 9.6 tons.Rail place accepted by rich lattice plate needs grinding, comprises two grooves of two sides tilted, bottom surface, bottom surface and two sides boundary, forms a complicated shaped face, grinding allowance 2 ~ 3mm, grinding accuracy 0.1mm.

Before 2006, German Bo Ge company is only had to have numerically control grinder and the emery wheel of this track plates of can polishing in the world.For realizing the production domesticization of high-speed railway key technology, the Ministry of Railways proposes grinding machine equipment and emery wheel and to domesticize requirement.At present, the rich lattice plate numerically control grinder that East China numerical control (Weihai) is developed has reached high-speed railway instructions for use, and by by the end of February, 2010, East China numerical control delivered is to Ministry of Railways high-speed rail construction enterprise more than 50 Tai Boge plate numerically control grinder (price about 1,440 ten thousand yuan/platform).The supporting diamond-impregnated wheel of lattice slab grinder is won with East China numerical control, originally all from the import of German Bo Ge company, electroplating technology makes, for ensureing the surface accuracy after the grinding of rich lattice plate, emery wheel working face is all mono-layer diamond abrasive material, and emery wheel surface accuracy is ensured by steel matrix.Strong plating diamond tool manufacturing enterprise of several families such as Tianjin Jia Qi diamond tool factories of China in 2008 develops this electroplated diamond grinding wheel, and emery wheel appearance and size is (maximum outside diameter) (installation aperture) × 200mm(width), diamond abrasive by electric deposition nickel be fixed on by taper seat, radius be the arc convex surface of 8.5mm, radius be the circular arc concave surface of 6mm and the face of cylinder form super large, on compromise face.

Domestic electroplated diamond grinding wheel in use exposes some allows the intolerable common fault of Bo Ge plate manufacturing enterprise, outstanding behaviours exists: (1) wheel life is low, the average life span of domestic emery wheel only has 1/3 of German electroplated diamond grinding wheel, and poor stability, main cause is that Domestic Plating technique does not pass a test, the diamond abrasive of circular arc concave surface is fixing loosely very easily to come off, and also often occurs that electrodeposited coating is peeled off in flakes and causes processing the phenomenon that cannot carry out; (2) working (machining) efficiency is low, and be about 1/2 of the rich lattice Company grinding wheel efficiency of Germany, domestic emery wheel is too close because electroplating technology defect makes diamond abrasive arrange, and chip space is little, and emery wheel easily blocks skidding, has to reduce rich lattice plate feed speed; (3) rich lattice plate percent defective is high, and the ratio causing rich lattice blackboard newspaper useless because emery wheel is unstable is up to 8%, and the ratio of German Bo Ge company is then lower than 0.5%.At present, the rich lattice plate emery wheel still dependence on import of 90%.Fundamentally solve domestic rich lattice plate emery wheel Problems existing, realize production domesticization, substituting import one, very urgent.

Win the shortcoming of lattice plate emery wheel based on above electroplated diamond, domestic many producers start the rich lattice plate emery wheel of research and development a new generation.Traditional diamond tool mostly is plating, sintering makes.Wherein, plating diamond tool only by coating machinery embedding mosaic diamond abrasive material, diamond and plating interface does not have bond strength; Sintered diamond tool metal dust mixes with diamond abrasive grains to damage by pressure to sinter to be made, and is that the sintering force produced by metal dust alloying holds diamond, to diamond without infiltrating also without bond strength.The diamond abrasive of these two kinds of instruments all can come off because of hold not and too early when heavy load operation, and abrasive material utilization rate is low, and life tools are short.Braze welding diamond technology is noted because the advantage of its uniqueness starts studied person.Braze welding diamond technology utilizes high temperature melting solder diamond and matrix to be welded together, owing to being enhanced primary treatment between diamond and solder, therefore bond strength is high, therefore compared to electroplated product, braze welding diamond abrasive grain can exposure more than 70%, therefore brazed diamond tool chip space is large, and use sharp, the life-span is long.If braze welding diamond technology to be successfully applied to the making of rich lattice plate emery wheel, will significantly improve emery wheel efficiency and life-span.

The relevant manufacturers that is representative with Danyang Hua Chang Tools Co., ltd in 2010 starts to manufacture experimently out and utilizes the mode of braze welding diamond to prepare rich lattice plate emery wheel.Its manufacture craft and electroplated grinding wheel different, be by diamond and the abrasive material of arranging on abrasive wheel substrate, then carry out vacuum brazing or laser braze welding.Due to its have that high bond strength, the reasonable exposure of abrasive material, abrasive material are good without additional heat damage, bonding agent anti-wear performance, steel matrix without distortion, emery wheel, once on probation, just achieves good effect.

No matter be that electroplated diamond wins lattice plate emery wheel or braze welding diamond wins lattice plate emery wheel, both are basically identical in appearance and size, all normally can realize grinding and win the function that surplus removed by lattice plate.But for the diamond cloth landforms of rich lattice plate grinding wheel surface, market there is not the standard appearance that is unified, also do not have relevant to rich lattice plate emery wheel landforms research report.Described landforms refer at the arrangement pattern of super hard abrasive on the whole working profile surface of emery wheel.

The people such as Nanjing Aero-Space University professor Xu Hongjun refer to the landforms optimization method to mono-layer diamond tool abrasive material in patent " having the process of the single layer soldering diamond concretion abrasive instrument optimizing landforms " (patent No.: ZL 200310106070.7).Its landforms optimization method proposed comprises physical modeling method and empirical modeling method.These two kinds of methods have certain directive significance for relevant parameter such as dynamic active grain spacing, chip space, the wear particle size etc. analyzing mono-layer diamond tool.Wherein empirical modeling method is only calculate dynamic Effective grains' number or the dynamic effective spacing of abrasive particle by modeling under determining condition of work shortly, not yet studies for instrument macroscopic view cloth landforms and research method such as the design parameters such as width of chip space, area of cloth segmentation, segmentation inclination angle.

Not yet have at present and report for the abrasive material landforms optimization method of rich lattice plate emery wheel and correlative study.On market, existing producer produces rich lattice plate emery wheel and mostly is segmented, but segmentation number, width of chip space and inclination angle, Mei Tiao cloth district and incline direction all different, even this also result in rich lattice plate emery wheel same manufacture craft also the grinding performance be not quite similar, mostly manufacturer is according to making experience and uses information feed back to carry out limited improvement, not systematic theoretical system instructs, therefore quite limited to the performance boost of emery wheel.

Summary of the invention

For above problem, the invention provides a kind of braze welding diamond and win lattice plate emery wheel abrasive material arrangement landforms optimization method, the mechanism of material is removed according to jatharapanvartanasana emery wheel diamond, in conjunction with grinding parameter and grinding condition, mathematics geometrical analysis is carried out to single layer soldering diamond-impregnated wheel grinding process and determines best grinding wheel surface abrasive material landforms with this.

Concrete landforms optimization method is as follows:

1, rich lattice plate emery wheel grinding is arranged on specialized nc machine tool by emery wheel, and under specific rotation speeds, feed speed control, lattice plate is won in grinding.When lattice plate is won in grinding, feed speed, grinding allowance and emery wheel rotating speed are all fixing, and for weighing the size that the parameter of emery wheel grinding performance quality is grinding load, the size operating current of grinding load reflects.Therefore, under above preset parameter, how raising emery wheel efficiency and the method in life-span mainly reduce emery wheel load.

Because grinding allowance when lattice plate is won in emery wheel grinding is comparatively large, if emery wheel not have the chip space of being correlated with, just can cause in grinding area local temperature too high, even if still certain grinding burn can be caused when there being cooling water.Therefore, grinding wheel surface grinding area is advisable with segmentation arrangement, and anticipate as shown in Fig. 5,6, the space between adjacent two sections can be used as chip area, discharges chip, and takes away part grinding heat.

There is a reasonably interval in the segments of grinding area.Due to when grinding, the diamond of actual participation grinding is along length of cloth region every in emery wheel direction of rotation diamond foremost.Therefore, in a certain period, the dynamic Effective grains' number N of emery wheel grinding is consistent with grinding segments N1.So segments is more, and Effective grains' number is more, when feed speed and grinding allowance certain, the load of sharing single abrasive particle is less.

Dynamic Effective grains' number N and the grinding segments N1 of emery wheel grinding try to achieve by formula (I);

$N1=N=\frac{F_N}{F_X}$ Formula (I)

F in formula (I) _nfor with the emery wheel grinding total load on emery wheel gyroaxis vertical cross-section, determined by parameters such as the special grinding machine power of rich lattice plate and emery wheel rotating speed, the amount of feeding, and a fixed value can be seen as, F _xfor the maximum load of single diamond abrasive grain, determined by the granularity of abrasive particle and grade, (the adamantine manufacturer applied is different, corresponding numerical value can difference to some extent, but all can find corresponding numerical value, and its index expressed mainly contains two, one is isostatic pressing strength, one is impact strength, is reflected the performance of its abrasive particle by this two indices, namely its maximum load capability);

Calculate the dynamic Effective grains' number N of lattice plate emery wheel is won for braze welding diamond must not lower than 65, namely segments N1 must not be less than 65 sections.If N1 is less than 65 sections, then the load that single abrasive particle is subject to is greater than its maximum, and the even Fragmentation Phenomena that weares and teares just appears in abrasive particle, affects the grinding life-span.

2, emery wheel area of cloth is divided into some sections, and the distance between adjacent two sections is the width of chip space of chip space.Width of chip space is also confirmable.Fixing because stock removal h is 2mm, and be that a grinding is removed, relative to abrasive wheel substrate surface, the extreme higher position h1 of abrasive particle grinding is about 0.95mm (being determined by diamond grit and welding effect), the amount of debris that then grinding is got off is huge relative to wear particle size, being discharged by chip is a very crucial step, otherwise it is too fast that grinding temperature can be caused to rise.Therefore, according to Fig. 1, the width of chip area at least can allow chip be taken out of from chip area, its chip area minimum vertical height equals stock removal h and removes last segmentation abrasive particle maximum grinding height h1 and a rear segmentation abrasive particle maximum grinding height h1 sum, according to geometrical relationship in figure, then there is following calculating:

$\mathrm{\α}=\arcsin \frac{\sqrt{R^2-{[R-(h-2h1)]}^2}}{R}$ Formula (II)

In formula (II), α is emery wheel segmentation sub-multiple angle, and h1 is the extreme higher position of abrasive particle grinding, and h is stock removal, and R is the radius of emery wheel;

$L=\frac{\mathrm{\πD\α}}{360}$ Formula (III)

In formula (III), D is emery wheel diameter, and obtain α according to formula (II), can calculate the minimum arc length L=7.22 of chip area according to formula (III), namely width of chip space is at least at more than 7.2mm.

3, because emery wheel grinding is the grinding of circular motion, then for ensureing grinding accuracy, the vibration of emery wheel vertical direction should be reduced as far as possible, for area of cloth, then need to ensure any time, be fixing along dynamic Effective grains' number axis cross section being born load, and can optimal value be reached.Ensure that active grain is continuous uniform distribution on the grinding cross section of vertical axis again.

If β is every length of cloth region and emery wheel lower end horizontal plane angle, when β=90 °, although dynamically Effective grains' number is maximum, the continuous of active grain on horizontal grinding cross section cannot be ensured.When β=0 °, emery wheel cannot normally grinding.Therefore, the actual minimum β of β is supposed ₁, maximum β ₂.

At calculating β ₁time, there are two kinds of limiting cases, namely emery wheel can realize the minimum angles β ' of normal grinding ₁and there is not minimum angles β when intersecting in emery wheel upper end in every length of cloth region " ₁.First β ' ₁determine according to the physical dimension (emery wheel diameter D, emery wheel height overall H) of width of chip space and emery wheel, obtain according to the geometrical relationship in Fig. 2:

${\mathrm{\β}}_1^{\′}=\arctan \frac{7.2}{\mathrm{\πD}}$ Formula (IV)

In formula, D is emery wheel diameter, and 7.2 is width of chip space.β ' as calculated ₁it is 0.3 °;

Know that again emery wheel outer surface is special-shaped curved, according to the physical dimension relation of emery wheel, can not intersect between the area of cloth of grinding wheel surface segmentation if ensure, according to formula (V) then to there is not when intersecting minimum angles β ＂ in emery wheel upper end in every length of cloth region ₁, as shown in Figure 7,

${{\mathrm{\β}}_1}^{\′\′}=\arctan \frac{H}{D-\frac{h^3}{{\tan \mathrm{\θ}}_1}}$ Formula (V)

In formula (V), h3 is inclined-plane, emery wheel upper end vertical projection height, and H is emery wheel height overall, and D is emery wheel diameter, and θ 1 is inclined-plane, emery wheel upper end and horizontal plane angle (Fig. 7), obtains β ＂ as calculated ₁=23 °;

β ₁above-mentioned two conditions need be met simultaneously, both ensured the normal grinding of emery wheel, require that again emery wheel can normal cloth and area of cloth is not intersected, compare β ' ₁, β ＂ ₁size, obtains β ₁=β ＂ ₁=23 °;

β 2=87.9 ° is obtained according to formula (VI);

$\mathrm{\β}2=\arctan \frac{H}{7.2}$ Formula (VI)

In formula (VI), H is emery wheel height overall;

To sum up analyze the scope of β is 23 ° ~ 87.9 °.

4, the grinding of high-speed rail plate emery wheel comprises emery wheel revolution and at the uniform velocity to advance two processes with emery wheel, is the compound movement united two into one by two motions.Formula (I) calculates the minimum Effective grains' number with gyroaxis vertical cross-section according to emery wheel revolution load and relevant parameter, but requires to need through type (VI) to calculate for the grinding on gyroaxis cross section, as shown in Figure 8.

When the spacing of the width of segmentation bar and segmentation bar is fixing, emery wheel participates in the effective length h2 of grinding and every length of cloth region and emery wheel lower end horizontal plane angle β following relation:

$h2=\frac{2W}{\sin 2\mathrm{\β}}$ Formula (VII)

In formula (VII), the every length of cloth peak width of W, h2 is the effective length of interior participation grinding.

From formula (VII), when β is 45 °, h2 gets minimum of a value.When β is less than 45 °, although h2 increases gradually, the length participating in grinding in the unit interval does not increase, and therefore gives up the interval being less than 45 °.When β is greater than 45 °, h2 increases gradually, and the length participating in grinding in the unit interval also increases gradually.Therefore, the scope 45 ° ~ 87.9 ° of β is good.This interval left side is minimum for vibrating, and abrasive particle load is maximum, and the vibration of interval right side is maximum, abrasive particle least-loaded.Because emery wheel grinding is the grinding of circular motion, then for ensureing grinding accuracy, the vibration of emery wheel direction of feed should be reduced as far as possible, for area of cloth, then need to ensure any time, be fixing along dynamic Effective grains' number axis cross section being born load, and can optimal value be reached.In conjunction with the vibration caused by emery wheel load to the affecting laws of grinding, through test of many times optimization, show that every length of cloth region and emery wheel lower end horizontal plane angle best region are 55 ° ~ 65 °, as shown in Figure 4.

Pass through said method, the present invention solves high-speed rail plate braze welding diamond emery wheel abrasive material preferably and to arrange the determination problem of optimum landforms, that is: grinding wheel surface grinding area segmentation arrangement, space between adjacent phase section is as chip area, segments must not be less than 65 sections, width of chip space is at least at more than 7.2mm, and the angle region of every length of cloth region and emery wheel lower end horizontal plane is 45 ° ~ 87.9 °, is 55 ° ~ 65 ° between optimal zone.Have grinding efficiency with the rail slab grinding wheel that the landforms that the method optimization draws are made high, speed is fast, the advantage that the grinding life-span is long.

Accompanying drawing explanation

Fig. 1 wins lattice plate emery wheel abrasive particle grinding schematic diagram;

Fig. 2 emery wheel can realize the minimum angles β ' of normal grinding ₁;

Fig. 3 area of cloth and emery wheel lower end horizontal plane angle maximum β ₂;

The best landforms of Fig. 4 high-speed rail plate braze welding diamond emery wheel area of cloth;

Fig. 5 high-speed rail plate braze welding diamond emery wheel side;

Fig. 6 high-speed rail plate braze welding diamond emery wheel front;

Minimum angles β ＂ when intersecting is there is not in the every length of cloth region of Fig. 7 in emery wheel upper end ₁;

Effective grinding length in Fig. 8 gyroaxis cross-sectional unit time;

The explanation of main mark in accompanying drawing: 1-diamond-impregnated wheel, 2-diamond abrasive grain, 3-win lattice plate.

Specific embodiments

Make high-speed rail plate braze welding diamond emery wheel, its concrete preparation method is:

(1) abrasive wheel substrate cleared up, polish totally, ensure that surface is without grease, stain, rusty stain etc.

(2) utilize special fixture, abrasive wheel substrate is fixed on scroll chuck.On this fixture, emery wheel can realize rotating vertically and the axially action such as inclination.

(3) carry out arrangement abrasive material on abrasive wheel substrate surface according to designed landforms prioritization scheme, arrangement abrasive material region first carries out calibration with calibration adhesive tape by best cloth segments 89 sections, and angle of inclination is 55 degree.Region occupied by adhesive tape is width of chip space; Then carry out adhesive coated at adhesive tape interval, certain viscosity is provided; Again by diamond with mechanical oscillation screen cloth uniform distribution in grinding wheel surface, grinding wheel axle level, first cloth spills the face of cylinder, then the cloth fixture that tilts, and cloth spills inclined-plane and special-shaped curved.After cloth completes, in diamond gap, cloth spills granularity is that (copper-based solder composition is as follows: copper-Xi-titanium for 80 object copper-base alloy tin solders, percentage composition is: copper 60% ~ 65%, tin 20% ~ 27%, titanium 16% ~ 26%), due to the effect of the binding agent between diamond gap, copper-based particles solder is adhered to, just obtain being furnished with solder and adamantine emery wheel semi-finished product, and then by under pasted calibration adhesive tape lifting, just can obtain the braze welding diamond of arranging by landforms optimization and solder landforms.Concrete landforms optimization arrangement effect is as follows:

1. area of cloth is divided into 89 sections; 2. width of chip space 8mm; 3. every area of cloth inclination angle is 55 degree; (4), after optimizing cloth, around diamond abrasive grain, be furnished with brazing alloy powder fill.

(5) after high-speed rail plate braze welding diamond emery wheel semi-finished product prepare, emery wheel is unloaded from fixture, be placed in vacuum brazing furnace and carry out vacuum brazing.The emery wheel of preparation as shown in Figure 5, Figure 6.Through reality test, it is high that its serviceability more conventional high-speed rail plate emery wheel has grinding efficiency, and speed is fast, the advantage that the grinding life-span is long.In addition, because the grinding life-span improves greatly, eliminate a large amount of handling emery wheel working time (every a pair emery wheel clamping with unload all need cost 2 ~ 3 hours), drastically increase production efficiency.

Claims (1)

1. a high-speed rail plate braze welding diamond emery wheel landforms optimization method, it is characterized in that the mechanism removing concrete material according to jatharapanvartanasana emery wheel diamond, in conjunction with grinding parameter, mathematical analysis is carried out to single layer soldering diamond-impregnated wheel grinding process, and determines best grinding wheel surface abrasive material arrangement landforms with this:

(1) under the prerequisite that the feed speed of lattice plate, grinding allowance and emery wheel rotating speed all fix is won in grinding, the segmentation of grinding wheel surface grinding area is arranged, space between adjacent two sections is as chip area, and obtaining dynamic Effective grains' number according to formula (I) is N, grinding segments N1:

$N1=N=\frac{F_N}{F_X}$ Formula (I)

F in formula (I) _nfor emery wheel grinding total load on the cross section vertical with emery wheel gyroaxis, Fx is the maximum load of single diamond abrasive grain, is determined by the granularity of abrasive particle and grade;

(2) the minimum arc length L of chip area is obtained, i.e. width of chip space according to formula (II), (III);

$\mathrm{\α}=\arcsin \frac{\sqrt{R^2-[R-(h-2h1)}{]}^2}{R}$ Formula (II)

In formula (II), α is emery wheel segmentation sub-multiple angle, and h1 is the extreme higher position of abrasive particle grinding, and h is stock removal; R is the radius of emery wheel;

$L=\frac{\mathrm{\πD\α}}{360}$ Formula (III)

In formula (III), D is emery wheel diameter;

(3) set β as every length of cloth region and emery wheel lower end horizontal plane angle, suppose that the minimum of a value of β is β 1, maximum is β 2, and when calculating β 1, there are two kinds of limiting cases, namely emery wheel can realize the minimum angles β ' of normal grinding ₁and there is not minimum angles β when intersecting in emery wheel upper end in every length of cloth region " ₁:

${\mathrm{\β}}_1^{\′}=\arctan \frac{L}{\mathrm{\πD}}$ Formula (IV)

In formula (IV), D is emery wheel diameter, and L is width of chip space;

${{\mathrm{\β}}_1}^{\′\′}=\arctan \frac{H}{D-\frac{h3}{\tan {\mathrm{\θ}}_1}}$

Formula (V)

In formula (V), h3 is inclined-plane, emery wheel upper end vertical projection height, and D is emery wheel diameter, and θ 1 is inclined-plane, emery wheel upper end and horizontal plane angle;

β 1 need meet above-mentioned two conditions simultaneously, has both ensured the normal grinding of emery wheel, requires that again emery wheel can normal cloth and area of cloth is not intersected, compares β ' ₁, β " ₁size, gets β ' ₁, β " ₁middle higher value is as the value of β 1;

$\mathrm{\β}2=\arctan \frac{H}{L}$ Formula (VI)

In formula (V, VI), H is emery wheel height overall;

(4) in emery wheel advance, the grinding length of effective grinding in the upper unit interval, is participated in conjunction with emery wheel gripper path analysis every length of cloth region, the i.e. change of abrasive particle quantity, when every length of cloth sector width and width of chip space are fixed, the effective length h2 of emery wheel participation grinding and β relation are such as formula (VII):

$h2=\frac{2W}{\sin 2\mathrm{\β}}$ Formula (VII)

In formula, W is every length of cloth sector width;

From formula (VII), when β is 45 °, h2 gets minimum of a value; When β is greater than 45 °, h2 increases gradually, and the length participating in grinding in the unit interval also increases gradually; When β is less than 45 °, although h2 increases gradually, the length participating in grinding in the unit interval does not increase, and therefore gives up the interval being less than 45 °, obtains the optimal angle scope of β.