CN104209821A - Constant-center-height grinding method of tapered roller centerless grinding machine - Google Patents

Abstract

The invention belongs to a constant-center-height grinding method of a tapered roller centerless grinding machine. A guide wheel drives a roller to be machined which is arranged among a grinding wheel, the guide wheel and a guide plate to rotate, and the roller to be machined is ground by the grinding wheel; during grinding, the center of the roller to be machined and the center of the grinding wheel are located on the same horizontal line. The constant-center-height grinding method of the tapered roller centerless grinding machine solves the problems that the machining errors are great, the operation is complex, the working efficiency is low and the like in the prior art, and has the advantages that the variation of an included angle between a connecting line of the center of the roller and the center of the grinding wheel and a connecting line of the center of the guide wheel and the center of the grinding wheel is less than 1/3 of that in the past grinding method, the operation is simple, the working efficiency is high and the like.

Description

Conical roller centerless grinding machine permanent center height method for grinding

Technical field

The invention belongs to method for grinding, refer to conical roller centerless grinding machine permanent center height method for grinding especially.

Background technology

At present, no matter be adopt through type or cut-in type processing method, the grinding of all rollers all adopts centreless grinding machine external to process, this processing mode primarily of emery wheel, guide wheel, guide plate (planker) tripartite in the face of institute process roller locate, roller is placed on the guide plate between emery wheel and guide wheel, and by guide wheel driven rotary.The onward impulse of roller is that the rib of guide wheel drives or guide wheel certain angle that tilts is carried out driven roller and travelled forward.After adjusting to the right place in the position of emery wheel, guide wheel, guide plate (planker) three aspect, the roller circularity of institute's grinding can be become better and better

The larger problem that above-mentioned method for grinding exists is the realization along with grinding process, emery wheel is due to finishing and self come off, diameter can reduce gradually, and guide wheel and guide plate are due to the reason of used material and grinding process, size changes hardly, thus cause roller grinding angle (angle that emery wheel center and the guide wheel line of centres and emery wheel center and roller centre line are formed) to have greatly changed, and then the circularity of institute's grinding roller there will be comparatively big error, if taper roller, its coning angle also can have greatly changed, cause being that processed roller does not reach corresponding standard, cause the generation of batch substandard product in industrial production.

Man-hour is added at normal roller; in order to avoid there is the underproof situation of this batch; abrasion of grinding wheel is to certain degree (general diameter consumes 30mm); operating personnel need shutdown to adjust the position of guide plate; that is the center to grinding roller (or title center is high) is needed to adjust; and adjust the position that the most effective way in roller centre position is adjustment guide plate, namely guide plate is up or down.The adjustment optimal position of guide plate is that the grinding angle of roller is adjusted to original grinding angle, but add man-hour actual, the position of adjustment, close to original position, is mainly determined with the quality of grinding roller, if process the circularity of roller and coning angle within the scope required.Therefore according to the requirement of processed roller, there is an adjustable less scope at the grinding angle of roller.Because aforesaid operations causes the technical problems such as complex operation in Grinding Process, inefficiency, parts adjustment difficulty be large.

Summary of the invention

The center height of roller to be processed in a kind of process is the object of the present invention is to provide not need adjustment, the simple conical roller centerless grinding machine of operating process permanent center height method for grinding.

According to the problem existing for common centerless grinder, key problems-solving of the present invention is exactly the grinding angle change for bringing due to the change of roller centre to be processed in grinding process during centerless grinding.The change at grinding angle is changed by the center (center is high) of roller and causes, and therefore, the problem solving center High variation just becomes the key of head it off.

Overall technology design of the present invention is:

Conical roller centerless grinding machine permanent center height method for grinding, is drive the roller to be processed be located between emery wheel, guide wheel, guide plate to rotate by guide wheel, and carries out grinding by emery wheel to roller to be processed; In grinding process, the center of roller to be processed and emery wheel are centrally located at same level line.

In process, the center (center is high) of roller does not change, or variable quantity is very small, and the variable quantity that the variable quantity of the circularity of the roller processed and angle etc. affect roller precision index is also just very little.

Concrete technical conceive of the present invention also has:

Preferred embodiment, by adjustment guide wheel, the center of roller to be processed and emery wheel is made to be centrally located at same level line.

Through applicant, repetition test is carried out to the method in the present invention, for same roller, emery wheel uses the minimum limit of size from being mounted to, and the change of the roller machining accuracy caused by the variable quantity that roller centre is high, completely within the scope required by roller.And in process, the position of guide plate does not need to carry out any adjustment.The operator that this method is processed for roller, operating process becomes very simple, and the precision (index such as circularity, coning angle) of the roller processed meets the requirements completely.

Processing method in the present invention is called the permanent center height filing of roller by applicant, and namely in process, the center height of roller does not need to adjust, and the roller precision of processing meets the requirements.

Mathematical Modeling of the present invention is as follows:

The derivation of equation is proved:

Parameter declaration:

H: roller centre is apart from the height at guide wheel center;

R: radius of roller;

G: guide wheel radius;

R: grinding wheel radius;

N: roller centre is to guide wheel centre distance;

A, B: be in two kinds of method for grinding respectively, the angle of roller centre and the emery wheel line of centres and guide wheel center and the emery wheel line of centres;

Suppose: the wearing and tearing of guide plate (steel high rigidity), guide wheel (steel high rigidity) are ignored, workpiece mill amount is ignored, and H, r, G, n are constant, R is variable (from large to small), are positive number.

According to theoretical H=(0.15-0.25) r of centerless grinding, and the centerless grinder parameters of existing specification, as: XF004,3MZ6025 etc., each constant value obtains scope as following table:

r	2.5-60	α,β	1-10°
				H	1-24	R	250-190
n	152-208	G	150

Method for grinding in the past:

$\sin A=\frac{H}{R+r};A=\arcsin \frac{H}{R+r}$

Method for grinding in the present invention:

$\tan B=\frac{H}{R+r+n};B=\arctan \frac{H}{R+r+n}$

Wherein $n=\sqrt{{(G+r)}^2-H^2}$

The derivation of equation:

$\frac{\mathrm{dA}}{\mathrm{dR}}=\frac{1}{\sqrt{1-{\left(\frac{H}{R+r}\right)}^2}}\·\frac{-H}{{(R+r)}^2}=\frac{-H}{\sqrt{{(R+r)}^2-H^2}}=\frac{-1}{\sqrt{{\left(\frac{R+r}{H}\right)}^2-1}}$

$\frac{\mathrm{dB}}{\mathrm{dR}}=\frac{1}{\sqrt{1+{\left(\frac{H}{R+r+n}\right)}^2}}\·\frac{-H}{{\left(R\right|r\left|n\right)}^2}=\frac{-H}{\sqrt{{(R+r+n)}^2+H^2}}=\frac{-1}{\sqrt{{\left(\frac{R+r+n}{H}\right)}^2+1}}$

Sum up: $\frac{\mathrm{dA}}{\mathrm{dR}}=\frac{-1}{\sqrt{{\left(\frac{R+r}{H}\right)}^2-1}};\frac{\mathrm{dB}}{\mathrm{dR}}=\frac{-1}{{\left(\frac{R+r+n}{H}\right)}^2+1}$

Compare the speed that A and B changes with R, only need to compare with .

Further, only need to compare with size.

Rate of change $P_1=\left|\frac{\mathrm{dA}}{\mathrm{dR}}\right|=\frac{1}{\sqrt{{\left(\frac{R+r}{H}\right)}^2-1}};P_2=\left|\frac{\mathrm{dB}}{\mathrm{dR}}\right|=\frac{1}{\sqrt{{\left(\frac{R+r+n}{H}\right)}^2+1}}$

Work as P ₁> P ₂shi You ${\left(\frac{R+r}{H}\right)}^2-1<{\left(\frac{R+r+n}{H}\right)}^2+1$

Abbreviation solution, $-n^2-2\mathrm{Rn}-2\mathrm{rn}-{2H}^2<0$

$R>-(\frac{H^2}{n}+\frac{n}{2}+r)$

Due to $n=\sqrt{{(G+r)}^2-H^2}$

$R>-\left\{\frac{1}{2}\right[\frac{2{(G+r)}^2}{n}-n]+r\}$

So will obtain maximum also need to solve minimum.

Because, function successively decrease.Function f (r)=2 (G+r) ², G is constant, and f (r) increases progressively in the span of r.

Function f (n) and function f (r) is independent of each other.

Therefore n get maximum 208, r get minimum of a value 2.5 time, obtain minimum.So minimum of a value be 10.31;

Therefore inequality-n ²-2Rn-2rn-2H ²when < 0 sets up,

The scope that R separates is R >-10.31.

Conclusion:

When R changes in R >-10.31 scope, A is faster than B change.

When R changes in R <-10.31 scope, B is faster than A change.

The span considering R is 190-250, is greater than-10.31, therefore A is faster than B change.

For grinding r=50 workpiece:

H＝20；

R＝50；

G＝150；

Rmax＝250；

Rmin＝190；

$n=\sqrt{{(G+r)}^2-H^2}=199$

In the past under method for grinding emery wheel maximum case:

In the past under method for grinding emery wheel minimum:

A ₂-A ₁＝0.94°

In the present invention, method for grinding is under emery wheel maximum case:

In the present invention, method for grinding is under emery wheel minimum:

B2-B1＝0.3°

Substantive distinguishing features acquired by the present invention and significant technological progress are:

Method medium plain emery wheel of the present invention consumption changes the angle of workpiece centre and the emery wheel line of centres and emery wheel center and the guide wheel line of centres hardly, and without the need to adjusting guide plate height in grinding process, angles of product is stablized.As can be seen from result of the test and mathematics model analysis, in method disclosed by the invention, the variable angle of roller centre and the emery wheel line of centres and guide wheel center and the emery wheel line of centres is less than 1/3 of method for grinding in the past, emery wheel is from maximum consumption to minimum, the angle of roller centre and the emery wheel line of centres and guide wheel center and the emery wheel line of centres only creates the change of 0.3 °, completely in workpiece angle tolerance controlled range.

Accompanying drawing explanation

Fig. 1 is the grinding structure schematic diagram of the present invention under emery wheel maximum case.

Fig. 2 is the grinding structure schematic diagram of the present invention under emery wheel minimum.

Fig. 3 is the grinding structure schematic diagram under existing method for grinding medium plain emery wheel maximum case.

Fig. 4 is the grinding structure schematic diagram under existing method for grinding medium plain emery wheel minimum.

Reference numeral in accompanying drawing is as follows:

1, emery wheel; 2, roller to be processed; 3, guide wheel; 4, guide plate.

Detailed description of the invention

Below in conjunction with embodiment, the present invention is described further; but it is not as a limitation of the invention; the content that protection scope of the present invention is recorded with claim is as the criterion, and any equivalent technical elements made according to description is replaced, and does not all depart from protection scope of the present invention.

The overall structure of the present embodiment is as diagram, and conical roller centerless grinding machine permanent center height method for grinding, is drive the roller to be processed 2 be located between emery wheel 1, guide wheel 3, guide plate 4 to rotate by guide wheel 3, and carries out grinding by emery wheel 1 to roller 2 to be processed; In grinding process, the center of roller 2 to be processed and emery wheel 1 are centrally located at same level line.

In process, the center (center is high) of roller does not change, or variable quantity is very small, and the variable quantity that the variable quantity of the circularity of the roller processed and angle etc. affect roller precision index is also just very little.

By adjustment guide wheel 3, the center of roller 2 to be processed and emery wheel 1 is made to be centrally located at same level line.

Claims (2)

1. conical roller centerless grinding machine permanent center height method for grinding, be drive the roller to be processed (2) be located between emery wheel (1), guide wheel (3), guide plate (4) to rotate by guide wheel (3), and by emery wheel (1), grinding carried out to roller to be processed (2); It is characterized in that center and the emery wheel (1) of roller to be processed (2) are centrally located at same level line.

2. conical roller centerless grinding machine according to claim 1 permanent center height method for grinding, is characterized in that, by adjustment guide wheel (3), making the center of roller to be processed (2) and emery wheel (1) be centrally located at same level line.