DE2742630A1 - PROCEDURE FOR LAPPING WORKPIECES ON A FLAT LAEPP MACHINE AND MACHINE TOOL FOR PERFORMING THIS PROCESS - Google Patents

Description

27A2630

Koslcovskoe Vysshee Tokrmicheskoe Uchilischo imeni N. R. Baiunana

ZUM LAPPJttiu / OJN WEKKS'i'ÜüKhi »AUi 'ElflJiK FLüCHLÄPPr-'. MAoCHIM UWD 'AEKKZiiUGMAoCHINE FOR IMPLEMENTATION DILSi ^ S

VEKFAKEfci ©

The present invention relates to the technology of surface treatment of workpieces made from difficult-to-machine parts Materials and can be used in many branches of the economy when machining workpieces made of steel, ceramics, Carbide, c ^ uarz, ruby, silicon, sapphire, glass and other materials apply.

This invention also relates to a method of lapping workpieces with free abrasive on a flat lapping machine and a machine tool to implement this process.

Awake to a well-known process for lapping work pieces » ken, the lapping tools are kinematically dressed directly with the workpieces themselves during the lapping of the workpieces, what by special cyclical change of size

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and direction of the rotational speeds of the links of the position mechanism of the lapping machine comes about.

A disadvantage of this known method is that that a phenomenon of mutual "running-in" of the lapping tools occurs in continuous operation, which reduces the workload is significantly increased and the effectiveness of the kinematic dressing is reduced. The inlet phenomenon is characterized are distinguished by two characteristics.

Firstly, the profile of the lapping tool takes on a stationary shape that deviates from the original shape of the worn one Work surface on. The profiles of the upper and lower lapping tools in the case of the two-sided Lapping each other to mating profiles, i.e. they copy each other in mirror image.

The reason for the mentioned circumstance is the methodological one Error in the procedure according to which the choice of the speeds regardless of the pressure redistribution over the surfaces of the lapping tools when they are worn is hit.

Second, the surface layer of the lapping tools is at the expense of the redistribution of internal stresses and the formation of a dynamic equilibrium (for the given wear conditions in the effective operating state) between *. '■ <>: see the number of fracture microcracks that are formed and those to be removed with the wear products that are necessary for

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the intensity of the surface shaping process the workpieces and the lapping tool (the lapping tools) are responsible, highly wear-resistant.

This means that the lapping of the workpieces with the simultaneous kinematic dressing of the lapping tools the change in the kinematic operating state in accordance with the known method for lapping the workpieces becomes cumbersome. Its duration increases sharply, and the Lapping accuracy will therefore depend on the duration of the dressing transition period.

One of the methods of eliminating the phenomenon of shrinkage is to cyclically change the size of the External pressure with the aim of bringing the system out of equilibrium.

In practice, when the required quality of the surface layer of the machined workpieces is reached, the geometric shape accuracy can be stabilized over time in two fundamentally different directions: Maintaining the initial geometric shape of the working surface of the lapping toolf Searching for a complex of factors of the lapping process that are relevant at any point in time for the state in question the working surface of the lapping tool ensures the minimum deviations from the required surface shape of the workpiece and the dimensional accuracy to be maintained

Also known are lapping machines for lapping work pieces that are placed between the lapping tools in the pockets.

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nes workpiece cage are housed, which is on an eccentric Shaft that carries a planetary gear that is connected to the The sun gear of a planetary gear is engaged.

The mentioned construction of the machine offers no possibility of the size of the rotational eccentricity of the workpiece cage and thereby changing the path of movement of the workpiece on the lapping tools during the machining process, d. H. the Perform lapping with simultaneous kinematic dressing of the lapping tools

The invention according to the SU copyright certificate Ur. 483 229, Class B 24b 7/22 describes a flat lapping machine intended for grinding and polishing flat surfaces, which has a fe * » first lower and one rotatable upper lapping tool, one Contains magazine receiving box, which is mounted on a gear with the sun gear of a planetary gear with a carrier and a driver, which is attached to the carrier axis, on which a between the gear wheel of the Magazine receiving box and the sun gear arranged ^ two-way gear sits freely, is in a kinematic connection, and the gear wheel of the storage box is on an additional axis arranged, which goes through the driver, which rests on the carrier,

This machine is special in general, with the following disadvantages afflicted

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No possibility of changing the gear ratio of the carrier's rotational frequency to the rotational frequency of the gear of the Magafcinaufnähmekastens when changing the .Eccentricity.

No possibility of changing the eccentricity in the machining process. The eccentricity can only be changed periodically when the machine is switched off.

In addition, the following constructive solutions for the adjusting mechanisms of the lapping machines are known, which increase the efficiency increase their work and improve the quality of the machined workpieces.

It is the purpose of the present invention to address the disadvantages to eliminate the known methods and machines for lapping workpieces and a perfected Läp ^ process and to develop a flat lapping machine that effectively implements this process.

The invention is based on the technical problem, ··.: \ J to develop such a method for lapping workpieces on lapping machines and, accordingly, a machine structure, that it becomes possible, the surface wear of the lapping tool or the wear of the workpiece surface to be controlled according to the given amendment law.

To solve the technical problem mentioned, a method for lapping workpieces is assumed a flat lapping machine in which the workpieces are housed in the pockets of a workpiece cage

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and the workpiece cage together with the workpieces rotating around its own axis together with the runout of this axis of the workpiece cage around the axis of the drive shaft of the

according to the invention

machine to be moved. This method is ^ characterized by that the axis of the workpiece cage except those mentioned Rotations and at the same time rotated with these about a certain, with it inconsistent and parallel axis which is eccentric with respect to the axis of the drive shaft, the machining time (t) for the setpoint the total rotational eccentricity (e) of the axis of the workpiece cage around the axis of the drive shaft based on the condition of uniformity of wear on the whole Surface of the workpiece (of the lapping tool) is determined, whereby the wear size is calculated from the formula:

^s \ K (v, a, ρ, h, T) vdt - amount of wear, ^t I

and tp - temporal integration limits,

^r o » ^a o * ^p o» "ο * * ο

K (ν, ί , ρ, h, T °) _t »K ₀ (V ₀ , βξ , _Po , h ₀ , T °) +

(h _t - h ₀ ) + d ^g o (T ° - T °) - size of the 7th

H ₀ iT

wear intensity of the material of the lapping tool (of the work pieces), which mean:

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ν speed of the relative movement of workpiece and lapping tool within each cycle _, sections of the speed change in size and direction, a tangential acceleration of the relative movement of workpiece and lapping tool,

ρ pressure between the surfaces of the lapping tool and workpiece,
h Size of the grinding gap between the workpiece and the tool

(Lapping tool),
T ⁰ temperature in the processing zone *

This technical solution allows the process of lapping workpieces according to the machining quality in two directions to stabilize, i.e. to maintain the geometric shape of the working surface of the lapping tools over time or programmed machining of workpieces by changing the regularity of wear on the surfaces over time of lapping tool and workpiece.

According to a variant of the present invention, when

Lapping a

the following factors of the process - speed of the relative movement of workpiece and lapping tool,! tangential acceleration of this movement and pressure that is generated in the contact zone between workpiece and lapping tool - changed in stages «'J ■ In this way, the machining process is changed by changing the wear4 * fc * 4el $ & t des

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Material of workpiece and lapping tool with cyclical change in the factors of the lapping process as a result of the increased effectiveness the mechanism of the formation of fracture microcracks in the material of the workpiece and lapping tool by grade, Performance and cost of machining optimized. According to another variant of the JSrfinduog

the order of the mentioned changes of the processing intensities is alternated, whereby first the workpiece is roughed at the speed * speed, tangential acceleration and pressure against an average nominal value up to a certain maximum be gradually increased, after which one comes back to the nominal values mentioned, and then the finishing takes place, in which the speed is gradually increased and the tangential acceleration of the relative movement of the workpiece and lapping tool is proportionally reduced.

The technical solution mentioned above offers the possibility of by superimposing coarse and fine lapping of the workpieces in one operation without changing lapping tools and abrasives due to the selection of an order of changing the pressure in the zone of contact of the surfaces of workpiece edge lapping tool, speed And '■ Tangential acceleration the relative movement of the workpiece and the lapping tool to increase the performance and the quality of the

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improve the worked area,

A flat lapping machine for lapping workpieces is expediently used to carry out the process, which are accommodated between the lapping tools in the pockets of a workpiece cage, which is mounted on a Jaczenterachse the drive shaft is arranged and rotating around the M ^ en axis of the workpiece cage, which is to the axes of the drive shaft and the mentioned eccentric axis is parallel, is offset by means of a planetary gear, according to the invention the planetary gear of the said planetary gear is arranged on the mentioned eccentric axis of the drive shaft and its own additional, to the above Axes parallel and with these inconsistent i & center axis on which the mentioned workpiece cage seated for rotation with total eccentricity around the axis of the drive shaft.

The present technical solution allows the size the total eccentricity and the speed of rotation of the cage axis around the axis of the drive shaft during machining of the workpieces by rotating an intermediate planetary wheel, which has an eccentric axis on which the workpiece cage with the workpieces sits around the oot center axis to change the drive shaft.

This machine can be more beneficial * ·! ^ With an on

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attached to the planetary gear hub of the first mentioned planetary gear additional planetary gear and a cross-loop clutch provided aein, in which one of the coupling halves is the planetary gear of the additional planetary gear represents, while the second rotatably arranged on an additional eccentric axis and rigid with the workpiece cage connected is.

This technical solution allows the rotational speed of the workpiece cage around its own axis by kinematic Connection of the workpiece cage with an additional one Planetary belt via the cross-loop coupling, which is ner change in the center of the workpiece cage in relation to on the axis of the drive shaft ensures the transmission of the rotary motion to the workpiece cage.

According to a further embodiment variant, a machine is also used to carry out the method a chuck cage that mounts on a gear is that with the sun gear of a planetary gear with a carrier and a driver on the carrier axis is attached, on which an arranged between the gear of the workpiece cage and the sun gear intermediate wheel sits freely, is in positive connection, and the gear the workpiece cage is arranged on an additional axis

which goes through the driver, which is supported on the carrier, the machine according to the invention in addition with a disc with an additional axle attached to it,

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which is arranged coaxially with the carrier, and a differential gear ^ is seen, one axis with the carrier and the other is connected to the disc via intermediate gears, the additional axis in the driving groove and protrudes into a circular arc groove incorporated in the carrier.

The present technical solution offers the possibility of determining the eccentricity size of the cage and lapping tool axis during the lapping of workpieces due to a Rotation of the gear wheel of the magazine receiving box including the driver around the carrier axis when acting on the To change the driver of the additional axis, which changes in the case of a phase change in the notation of the disc due to the rotation the housing of the differential, which connects the movement of the disc and the carrier, in the arched hat of the carrier moves.

In the following, the present invention will be explained in terms of one practical exemplary embodiment in the technical description below and through the accompanying explanatory drawings explained in more detail, it shows

1 and 2 are schematic views of the eccentric machine according to the invention, wherein; Pig. 1 one of the possible paths of relative movement shows the axis of the workpiece cage in be-BUg on the axis of the lapping tools, Fig.? a and b possible trajectories of the axis of the

Workpiece cages opposite that of the Läppwerkeeu-

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ge with the eccentric machine according to Pig. 1, 2,

Fig. 4- the structure of the eccentric machine according to the invention, which makes it possible to determine the size of the axis of the workpiece cage with respect to the To change the axis of the lapping tools in the work process (longitudinal section),

5 shows the structure of the eccentric machine according to the invention, which makes it possible to determine the size of the eccentricity of the axis of the workpiece cage with respect to the Change the axis of the lapping tools in the working process and the speed of rotation of the To control the workpiece cage around its own axis,

6 shows the construction of the cross-loop coupling used in the construction of the machine according to FIG the transfer of the rotary motion from an additional planetary gear to the workpiece cage guaranteed

7 shows the structure of the eccentric machine according to the invention, which makes it possible to determine the size of the eccentricity of the axis of the workpiece cage with respect to the Change the axis of the lapping tools in the working process and the speed of rotation of the Control workpiece cages around their own axis, FIG. 8 is a plan view of the actuating tool of the drive of the workpiece cage when building the machine

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according to FIG. 7.

By retrograde-oscillatory cyclical eccentric planetary motion the axis 1 (Fig. 1, 2) of a workpiece cage 2 with a simultaneous change in the size of the offset "e" in the machining process and by simultaneous rotation about axis 1 of workpiece cage 2 with workpieces 3 the workpieces move with variable or constant rotational speed during the lapping process, complicated paths in relation to the working surfaces of the Lapping unitBBUge.

1 shows one of the possible paths ABCD of the relative movement of the axis 1 of the workpiece cage 2 with the workpieces 3 in relation to the working surfaces of the lapping tools' 4th

In this case, the Bearneitungszone 5 is on the by-

/ tools fang the whole working surface of the lap ^ 4 located.

In Fig. 3 (a, b) different types of tracks a, .... a shown, on which the axis 1 of the workpiece cage 2 migrate (opposite the axis of the lapping tools 4) around which the workpiece cage 2 rotates.

The vibration amplitude of the workpieces 3 on the work surfaces of the lapping tools 4 and the machining time within each zone 5 of the working surface of the lapping tools »Ground based on the condition to be followed of the equality of the amount of wear of each surface element

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ment of the lapping tool 4 (the lapping tools) is determined.

The wear of each surface element of the Läppweri tools 4 is determined for each kinematic processing intensity in the time At = t ₂ - t ^ and from the formula t.

K (ν- ,, a ', ρ, h, Τ ^υ ) vdt (I)

calculated, whereby the size of the wear intensity of the mali o terials of the lapping tools K (v, a, p, h, T) is a function of the speed (v) of the relative movement of the workpiece on the surface of the lapping tools, tangential acceleration (a), specific pressure ( p) _ between workpiece and tool (lapping tool), size of the grinding gap between workpiece and tool (lapping tool), i.e. thickness (h) of the intermediate grinding layer, temperature (T) in the machining zone and dimension ju, m / mm or m / mm . t ^ and t ~ are integration limits in time.

The wear intensity (K) is the first approximation according to Taylor's formula

JC (v, a *, p, h, T ⁰ ) * K ₀ (v ₀ , a *, p _Qt h _Q , T °) +

a. O (Vi. - V) O (fii. - ^ n ^ O ^ Pf- "" Pn ^ "**

h ₀ ) ₊ -Ifo-CT «! - T ° _o ) (II)

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-y / 2 27A2630

% ο
calculated, where ν, a, ρ, T are corresponding values of

ν, a, ρ, h, T ⁰ at time tj and v _t , a ^., p _t , h ^, T °

rf O

are corresponding values of v, a, p, h, T at time t ~.

In order to increase the effectiveness of the kinematic dressing Then the zone processing is based on the equality of the wear size of the working surface of the lapping tools 4 guided in their individual zones 5 d. H.

V ₁ = V ₂ = % =. ··· V ₁ = ... = Tf _n du),

where i = 1, 2, 3 # .. η is the number of the zone within which the lapping is carried out either with their successive or different combination.

The present lapping process, which the evenness of the wear of the surfaces involved in the machining process can be used for the surface processing of the workpiece based on the equality of the material removal in the individual ring zones of the workpiece surfaces with one or two-sided »lapping by successive or continuous Modification of the mutual arrangement of the axes of the lapping tool and workpiece applied in the working process will.

In this case, the tool (the lapping tool) comes into contact with the workpiece after the individual zones of the workpiece, thereby controlling the shaping process the surface of the lapping tool and workpiece is guaranteed.

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The amount of wear of the working surface of the lapping tool (workpiece) is fundamentally influenced by such factors of the process like

ν Speed of the relative movement of the workpiece on the surface of the lapping tool (the lapping tool on the workpiece),

a Size of the '^ angentia! acceleration during the relative movement the workpiece on the surface of the lapping tool (the lapping tool on the workpiece), ρ Size of the specific pressure in the processing zone between tool and workpiece,

h size of the soleplate gap between workpiece and tool,

T ^{0 influences the} temperature in the processing zone »

The change in the size of individual as well as several factors at the same time leads to a change in the wear intensity of the material of the sample workpiece (the lapping mandrel), the dependencies of the change in the wear intensity of the material of the sample (K ₀ ) and the lapping tool (K _d ) on the speed value the relative movement (v) of the workpiece on the lapping tool, the tangential acceleration (a) and the level of the contact pressure (p) are determined experimentally by specifying the values

from K and K ^ for the materials silicon and ceramic be-ο

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confirms.

Bs is also found that the temperature on the Properties of the non-abrasive part of the paste exerts influence and the heat condition of the processing, which the Ver *; Intensity of wear (K) of the material influences, regulates.

The physical basis of the present method is: Establishing a state of equilibrium stress in the material of the workpiece and the lapping tool during zone lapping, which is due to the uniformity of the distribution of the contact pressure in the workpiece-lapping tool contact zone while all workpieces dwell at the same time is achieved in a certain zone within a kinematic operating state of the cycle, union the zone lapping in a constant kinematic operating state with the lapping of the workpieces by means of the whole Working surface of the lapping tools with a change in the kinematic Operating states within the cycle. When lapping the workpieces with the entire surface of the lapping tools thus takes place the transition from a kinematic operating state on the other hand within a processing sequence.

In this pail the equilibrium state of tension will be found of the material determined by the level of stresses and density of the microcracks when the kinematic changes Operating conditions is evaluated, change periodically.

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A lapping process can have two or more kinematic operating states include, the characteristic of which is the transmission ratio ipb (see P. N. Orlov "Diamantschleifläppen of workpieces "/" Almazno-abrazivnaya dovodka detalei "/ Publishing house of the Research Institute for Mechanical Engineering / NII MASh / I972I.

The transition from zone lapping to lapping the workpieces with the entire surface of the lapping tools also take place automatically with the help of an eccentric mechanism (Fig. 4), in its construction a composite! eccentric shaft is provided, which consists of a driving eccentric shaft 6, on whose eccentric axis 7 a planetary intermediate wheel 8 sits, which is in engagement with the shaft 9 of a planetary gear and an additional eccentric axis having the axis 1 of the workpiece cage 2 with the Workpieces 3 »which are machined with the lapping tools 4, represents. The additional eccentric axis is also used denoted by 1.

The above-mentioned construction of the composite eccentric shaft enables the eccentricity "e" of the arrangement of the pivot point of the workpiece retainer with the workpieces with respect to the pivot point of the lapping tools during machining of the workpieces from wull to

To change the maximum value "e_ · '.
Max

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During the machining process, the workpieces can be concentric Movements with respect to the center of the working surfaces of the lapping tools, periodically associated with movements on epi-, hypo- and pericycloid tracks in the eccentric device Run the machine (see P. N. Orlov "Diamond grinding lapping of work pieces "/" Almazno-abrazivnaya dovodka detalei "/ Publishing house of the Research Institute of Mechanical Engineering / Nil MASh / 1972).

With changing speeds, the quality of the surface layer becomes lower, and therefore the finishing must be carried out with a constant speed ( ^v _cons t) of the movement of the workpiece on the surface of the lapping tool, i.e. the movement must be on a circular path, while the roughing with variable Velocities (V _r ) and variable sizes of the tangential acceleration (a) is to be carried out,

This lapping process with periodic or continuous Changing the vibration amplitude of the workpiece on the surface of the lapping tool will allow the Lapping process in the machining accuracy of the workpiece by maintaining the profile shape of the lapping tool in required range of deviations from flatness, spherical shape (for flat, spherical lapping tool), etc. to stabilize.

Due to this procedure, the process f, i- can also:

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the processing of tier vverstucke based on the application of the given zone processing methods can be realized, d. H. the processing of the work piece according to its individual zones (zone processing dei * workpiece surface) using the same Wear printouts and ratios to determine the sequence the decrease in material from the height of the workpiece whose individual zones are realized.

The invention consists in a lapping process that a cyclical and periodic change in the angular or multiple speeds the links of the actuating mechanism of the machine According to the law of wear and tear on the work surfaces of the lap tools according to the distribution of the mechanical work, the following applies:

^{A = K} g JV ^ eifc + r ^^ 'fi ^^'Wbc'cos ^ -ni ^ Jt at (IV)

worm mean:

K factor that influences the dynamics of the la ^ p process

taken into account,
R and r ^ K-oiuponenten of the vector calculation sschemas der

Determination of the orbit of the relative movement of a surface point of the lappv.ex 'tool on the workpiece, c * ^ _b AinKelgeschwindigKeit of

with regard to the workpiece cage,

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vr

CO angular velocity of the lapping tool with respect to

"C

the package cage,

t. and t start and dead time of point tJarführung d, es ¹ 2

Lapping tool with the workpiece.

Furthermore, an additional stages change of ^ eüchwindigkeit, tangential acceleration, the Belativbewe _ö ung of the workpiece introduced to the lapping tool, and pressure in the workpiece-lap-contact zone with alternating order of change, wherein first the Schrupw pen of the workpieces, wherein the speed Tangentialbe * ,. acceleration and pressure are increased cyclically with respect to a nominal value, and then the finishing takes place, in which the speed is increased cyclically and the tangential acceleration is reduced proportionally.

Taking into account the change in the mentioned factors of the lapping process and their temporal interaction offers the possibility of creating a controlled lapping process for both one-sided and two-sided machining. If the performance of the process is made the optimization criterion, the interaction of the factors v _t a and ρ must ensure the greatest possible amount of material decrease (the wear intensity) of the workpiece. If the quality of the surface layer of the workpiece is made the optimization criterion for the lapping process, the interaction of the factors v, a ^L and ρ must ensure that the required

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Secure the size (depth) of the disturbed layer and the degree of disturbance in this.

The physical basis of the influence of the load dynamics of the iaystems "workpiece ^ grinding interlayer lapping tool" on the characteristic values of the lapping process forms the change in the physical-mechanical properties of the surface layers of the workpiece and the lapping tool at different ratios of pressure p, speed ν and acceleration a.

Fig. 1 shows a path of the relative movement of the workpiece on the lapping tool, the type of which is determined by the transmission ratio ± 2)} - ^ / ^ b C ratio of the speed n ~ of the workpiece cage to the speed n. Of the conventional l'ra ** 'gers) given is·

The proportional change in the speeds up and n »caused a change in the mean speed level and the acceleration of the relative movement of the workpiece 3 on the lapping tool 4 without changing the type of trajectory changes.

One and the same type of trajectory a, aj-, a ~ ... a of the relative movement of the workpiece 3 on the lapping tool 4 in epicycloidal form can exist for two absolute values of ν and sr at any point in time (Fig. 3a and b), ie the workpiece moves on the same path with different ones
nen absolute amounts of ν and a.

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The absolute values of the speed ν uad of the tangential acceleration a ^{L of} the relative movement of the workpiece 3 on the lapping tool M- are given by the values of the angles Ige * :. . ¹ ^ speeds of the links of the adjusting mechanism of the lapping machine and can be calculated according to the well-known formulas of theoretical mechanics.

Different sensitivity of the material of the workpiece and lapping tool against the action and interaction of the factors v, a and p, which mainly result in the change the structure (structure) of the layer disturbed by the processing and the depth (otickness) of the zone with microcracks as well as the zone with elastic and plastic deformation, occurs depending on the properties of the system "Wt-rkbtück-grinding interlayer lapping tool" and in particular the degree of solidification or embrittlement of the surface layer determines the material of the workpiece and the lapping tool revealed.

By cyclical change of speed v, acceleration a and pressure ρ according to periodic or aperiodic A tense state of imbalance can be created in the surface layer and a change in the law Distribution law of storage disturbances and other errors both according to the depth of the individual zones and according to the entire depth of the surface layer.

The propagation of the fracture microcracks of the individual faults

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The depth will depend on the (amplitude frequency) characteristics of the effective alternating voltage in the upper layer, which changes the character and the speed of propagation of the fracture microcracks. The changes in the factors v, B? and ρ cause a change in the amount of mechanical work that is expended for the wear of the materials of the lapping tool and work piece. and finish lapping in one operation without changing the lapping tool and changing the abrasive grain size, as has been the case up to now, and due to a special sequence of changing speed v, acceleration a and pressure ρ with their various alternations. Bs is for this purpose in rough lapping with cyclical change in the speed v, which is carried out in accordance with the known method for lapping the workpieces, proposed to change the acceleration a and the pressure ρ at the same time such that each speed increase a

<r

corresponds to a proportional increase in the acceleration a and a one and a half to two-fold decrease in the pressure ρ and vice versa, with finish lapping the acceleration ar is proportionally reduced when the speed ν increases and the pressure φ is maintained at the same level. In special cases, no change in one of the

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goals are made.

i) the order in which the speed v, loading

T T II

acceleration a and pressure p, ie ν - * ■ ρ - * ■ a ^u or v — a ^ - · - »p odir ν -» p- * v- * a ^t etc. or a - · ■ ρ - »" ν or ρ-— ν— »ar or ρ—» a - *> p or a - »· ρ -» - ν as well as the change in their level (vj—>Vp—> pj— »Pp— ψ a or Pj - * Pp - * · vj- -> · Vp— ^ v, etc.) allows the malleability and brittleness, size and law of stress changes in the surface layer of workpiece and lapping tool depending on the properties of the system "workpiece-grinding interlayer-lapping tool "to control.

From the point of view of the fracture mechanics of brittle materials In the lapping process, every elementary act of forming and removing particles (chips) of the material from the workpiece is retained and lapping tool with a single abrasive grain all the main features of the breaking process, namely: Reinforcement the effect of the brittle fracture mechanism of the residual body when it is increased the stress dynamics, in the lapping process the stress dynamics increase of the surface layers of the material to be lapped -with the increase in tangential acceleration a * der Relative movement of the workpiece on the lapping tool to «

In order to increase the materia! ^ Decrease must therefore be non-monotonous Stress conditions are created. It is therefore suggested to increase the performance of rough lapping, to increase both the speed and the acceleration of the relative movement.

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The change in pressure must go in the direction of its decrease with the increase of ν and a. The elimination of all sorts of non-stationary states in the micro-cutting process contributes to a reduction in the degree of destruction of the surface layer and to a decrease in the depth of the defective layer with a high degree of inhomogeneity of the stress state and the fracture microcracks. When finishing lapping brittle materials, when a high-quality surface layer has to be produced, it is therefore proposed that every cyclical change in speed ν according to the known lapping process be accompanied by a declining change in acceleration & r while the pressure ρ remains constant. By constantly controlling the speed, acceleration and pressure in the lapping process using the kinematic dressing of the lapping tools or the workpiece surface to be machined, it appears possible to carry out both the rough and the final lapping of the workpieces in one operation, thereby increasing the productivity of the process high quality of the lapped surfaces is increased.

The use of the proposed lapping process in the manufacture of ceramic supports allowed the shape accuracy to be improved to increase the spherical surfaces and to increase the wear resistance of a lot of ceramic supports by 1.5 to 2 times «

Fig. 4 shows the scheme of the construct according to the invention

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tion of the machine for lapping workpieces with free,. Abrasive according to the method mentioned above.

The machine consists of a driving eccentric shaft 6 on which an eccentric axis 7 with an eccentricity size "e / p" with respect to the center axis 0-0 is arranged is. On this axis 7, a planetary intermediate wheel 8 is movably mounted by means of bearings 10, the external gear ring 12 with the internal ring gear 13 of the shaft 9 of the planetary gear is engaged.

Is located on the rlanetenzwischenrad 8 with eccentricity "e j *" i ⁿ tfezug on its axis an additional eccentric shaft 1, which is the axis of a workpiece cage.

Workpieces 3 are housed in the workpiece cage 2, which are located between lapping tools 4-.

The rotary drives for driving eccentric shaft G ₉ shaft 9 and lapping tools 4- are not shown.

The workpieces 3 to be machined are placed in the workpiece cage 2 and placed between the lapping tools 4 machined, whereby they are complicated by eccentric movement and rotation about the additional eccentric axis 1 on paths Kind of wandering.

Due to the compound used in the construction of the machine Eccentric shaft, which consists of the driving Jäxzenterwelle 6, the planetary intermediate wheel 8 and the additional Eccentric axis 1 exists, the

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Change the size of the total eccentricity "e" between the center point of the workpiece cage 2 and the pivot point of the lapping tools 4 from wull (O) to the maximum value (β ™ ο _χ ).

The machine works as follows.

If the speeds of the driving eccentric shaft 6 and the shaft 9 of the planetary gear are equal, the intermediate planet wheel 8 does not rotate about the axis 7> and the axis CT-O consequently rotates about the axis 0-0 with constant total eccentricity "e", the size of which in Depending on the initial position of the additional eccentric axis 1 can be from zero to its maximum value.

When the shaft speeds do not match 6 and 9, the planetary intermediate wheel 8 is set in rotation about the axis 7, which changes the size of the planet over time Total eccentricity of the additional eccentric axis I with respect to the central axis 0-0 causes.

At the time when the position of the additional over-center axis 1 coincides with that of the center axis 0-0 (the turning radii of the axis 7 around the center axis 0-0 and the additional eccentric axis 1 around the axis 7 are ^{equal to each other and Me} _max / 2 "), the angular speeds of rotation of shafts 6 and 9 will be the same, and the workpieces will move in the workpiece cage on circular paths over the surfaces of the lapping tools

By varying the speeds of the driving

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27A2630

Eccentric shaft 6 and the shaft 9 and the speeds of the lapping tools 4 different movement paths of the workpieces can be obtained on the lapping tools, i. H. it can the case of zone machining of the workpieces (machining of the workpieces within a certain zone of the lapping tools with the possibility of expanding the exercise zone ',;. · and the transition to machining on the entire surface of the lapping tools) can be achieved, whereby the intensive

tools The kinematic dressing of the lapping is ensured by the workpieces themselves.

Fig. 5 shows the scheme of a further embodiment variant te of the machine for lapping workpieces, Fig. 6 illustrates elements of the cross-loop coupling in this Machine.

The machine consists of a driving eccentric shaft 14 on which _{an eccentric axis 15 is located with an eccentricity size e m} / p with respect to the center axis 0-0. A planetary gear 17 with a hub, the external gear ring 18 of which meshes with the sun gear 19 of a hollow shaft 20, is movably placed on this axis 15 by means of bearings 16.

On the iMabe of the planet wheel 17 is coaxial with this an additional planet wheel 22, the upper end face 23 of which represents a coupling half of the cross-loop coupling, arranged by means of bearings 21.

The external gear 24 of the additional planetary gear 22 is located with the Inneneahnrfetd 25 of a spindle 26 in one

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griffι with the driving eccentric shaft 14 and the Hollow shaft 20 is arranged coaxially.

An additional eccentric axis 27, which forms the axis of the workpiece cage 28, is arranged on the rotating wheel 17 with an eccentric size e _max / 2 * ^{n Zug on its axis.}

On the additional eccentric axis 27, the upper disk (coupling half) 30 of the loop coupling is arranged by means of bearings 29, which is in a rigid 7-way bond with the workpiece cage 28. The lower end face of the disc 30 has ^r ..ι a rage 31, in which the projection of the washer protrudes 32 of the clutch. On the opposite side, the intermediate disk 32 also has a projection which protrudes into the joint of the lower disk of the loop clutch.

Workpieces 33, which are located between lapping tools y \ and 55, are accommodated in the workpiece cage 28.

The rotary drives for center shaft 14 _t > i * elle 20, spindle 26 and lapping tools 34 »35 are not shown.

The machine works as follows. The workpieces 33 to be machined are introduced into the workpiece cage 28 and machined between lapping tools 34 and 35, wherein they move by eccentric movement and rotation about the eccentric 14 on a complicated path.

The size of the total eccentricity can change from zero to the maximum value during operation.

If the speeds of the driving Ex-

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Zenterwelle 14 and the shaft 20, the planet gear 17 does not rotate about the axis 15, and the additional iixzenterachse 27 therefore rotates around the center axis 0-0 with a constant Total eccentricity, which depends on the starting position of the additional eccentric axis from zero to Maximum value can be.

In the event of a mismatch in the speeds of the driving Eccentric shaft 14 and the shaft 20, the planet gear 17 is set in rotation about the axis 15, which is a temporal Change in the total eccentricity of the additional eccentric axis 27 with respect to the center axis 0-0 causes.

At the time when the position of the additional eccentric * » se 27 coincides with that of the center axis 0-0, the angular speeds of rotation of shafts 14 and 20 are compensated, and the workpieces 33 move in the workpiece cage 28 on circular paths over the surfaces of the lapping mandrels 34 and 35

The rotary movement is carried out by the spindle 26 via the planetary gear transferred to the lower disk of the loop clutch, to which the intermediate disk 32 and the upper Disk 30 belong to the one with the free on the additional Eccentric axis 27 arranged workpiece cage 28 rigidly connected is·

If the speeds of the HobUrelle 20 and the spindle 26 is the additional planetary gear 22 in besug on the planet gear 17 and consequently the workpiece cage 28 around

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in

the additional eccentric axis 27 not ^ additional inevitable Offset.

If the speeds of the shaft and the spindle 26 do not match, the workpiece cage 28 is additionally rotated the additional eccentric shaft 27 is driven.

By varying the rotational speeds of the driving eccentric shaft 14, hollow shaft 20, spindle 26 and lapping tools 34, 35 can have different trajectories: of the workpieces 33 on the lapping tools, i.e. the cases of zone machining of the workpieces (machining of the workpieces within a certain zone of the lapping mandrel) with the possibility of expanding the machining zone and the transition for processing on, the entire surface of the lapping tools can be achieved, thereby increasing the intensity of the kinematic dressing of the surface of the lapping tools by the workpieces itself is guaranteed.

Fig. 7 shows the scheme of a next construction of the machine, in Fig. 8 the drive is the magazine receiving box shown «

The machine contains a magazine receiving box 36 with work pieces 37 in pockets between the two lapping tools 38 and 39 arranged and mounted on the gear 40 of the magazine receiving box 36, which with an intermediate gear 41 combs. The '! Axis A-A of the gear 40 of the magazine receiving box 36 is with a driver 42 in 7th

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bond that is freely placed on the axis G-C of the intermediate wheel 41 is.

The intermediate gear 41 is engaged with a sun gear 43 and freely placed on the axis CG, which is attached to a carrier 44 . The axis AA rests on the ^f ..? Carrier 44 and can rotate together with the driver 42 with respect to the axis CC.

An additional shaft 45 has a disk 46 with an additional axis BB attached to it, which goes through the circular arc groove of the carrier 44 and protrudes into a groove incorporated in the driver 42, thereby forming a link mechanism between the additional shaft 45 and the driver 42. The movement is transmitted from a drive 47 to the carrier 44 and the additional shaft 45 via gear drives 48 and 49 and a bevel gear differential 50. The housing of the bevel gear equalizer 50 can be pivoted about the vertical axis with the aid of a handle 51. The eccentricity of the arrangement of the axes of rotation of the gearwheel of the magazine receiving box and of the sunwheel is due to the angle of rotation of the additional shaft 45 with respect to. given the carrier 44.

The machine works as follows. The drive shaft 47, 48, 49, 50 set the shaft 45 with the disk 46 and the carrier 44 in rotation, the axis of the carrier 44 forcing the idler gear 41 to roll on the sun gear 43 and drive the gear 40 of the magazine receiving box $ 6. the

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Workpieces 37 arranged in the openings of the magazine receiving box 36 are machined between the upper lapping tool 39 and the lower lapping tool 38. The seals dei angular velocities Cü_ and LO _ of the carrier 44 and the gear 40 from the magazine receiving box 36 are the same. The angle o ( between the additional shaft 45 with the disk 46 and the carrier 44 is given by the transmission ratio of the intermediate gears 48 and 49 and by the pivoting angle ε of the housing of the bevel gear differential 50 : 1) is the angle of the angle B is the same when changing the angle ^ 50 is rotated and the angle o (and the eccentricity e during the machining of the workpieces 37 to change so the driver 42 by pivoting of the housing of the bevel differential gear..

This offers the possibility of automating the technological lapping process of the workpieces and improving their quality Au, because the control of the lapping parameters is possible directly during the machining of the workpieces using the present machine .

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L ee side -S9-

Claims (1)

LJ method for lapping workpieces on a flat lapping machine, in which the workpieces are accommodated in the pockets of a workpiece cage and the workpiece cage and the workpieces are offset in rotation about their own axis together with the out-of-roundness of this axis of the workpiece cage around the axis of the drive shaft of the machine, characterized in that the axis (1) of the workpiece cage (2) is rotated in addition to the mentioned rotations and simultaneously with them about a certain, inconsistent and parallel axis which is eccentric with respect to the axis of the drive shaft, the machining time st) for the nominal size of the total rotational eccentricity (e) of the axis of the workpiece cage (2) around the axis of the drive shaft based on the condition of uniformity of wear on the entire surface of the workpiece (3) (of the lapping tool), the amount of wear being determined from calculated using the formula i = fc Ϊ (V, a, ρ, h, T ⁰ ) vdt - wear eating size, ^fe I tj and t ₂ - temporal limits of integration, I (v, J , p, h, T ⁰ ) * K ₀ (V ₀ , a ^r , p ₀ , h ₀ , T ⁰ ) + v _t - v ₀ ) ₊ 1 * 0. (a * - a *) ♦ ifo (p _t - p _Q ) ₊ • 0M11 / HI ORIGiNAL INSPECTED h) '+ * ^Κ ο (ϊ ° - τ °) - size of wear intensity of the material of the lapping tool (the workpiece), where mean: ν speed of the relative movement of workpiece and lapping tool within each cycle section of the speed change in size and direction, a ^u tangential acceleration of the relative movement of workpiece and lapping tool, ρ pressure between tool (lapping tool) and workpiece, h size of the grinding gap between workpiece and tool (lapping tool),
T ⁰ temperature in "the processing zone. 2, process for lapping on the Flachläppmaschine according to claim 1, characterized in that the following factors of the process - speed b of the ■ relative movement of the workpiece and lap, I'angential eschleunigung this movement and .Druck that in the contact zone of workpiece O) and Lapping tool (4) is generated, - can be changed in stages during the lapping process. 3. A method for lapping workpieces according to claim 2, characterized in that the order of the mentioned changes in the machining intensities is alternated, whereby zueret the roughing of the work « • 0M13 / 0I00 Occasionally, the speed, tangential acceleration and pressure are gradually increased compared to an average nominal value up to a certain maximum, after which one comes back to the mentioned if values, and then the ierti _c processing takes place, in which the speed increases gradually and the tangential acceleration of the. Relative movement of workpiece and lapping tool is proportionally reduced β 4. Flat lapping machine for lapping workpieces that are accommodated between the lapping tools in the pockets of a workpiece cage, which is arranged on the drive shaft and around the axis of the workpiece cage, which is parallel to the axes of the drive shaft and the eccentric axis mentioned, by means of the Planetary drive is set in rotation, according to the method according to claim 1, characterized in that the planetary gear (8) of the said planetary gear (9) is arranged on the said eccentric axis (7) of the drive shaft (6) and its own _t to the above-mentioned Axes parallel and with these inconsistent additional eccentric axis (1) on which the mentioned workpiece cage (2) sits for rotation with total eccentricity around the axis of the drive shaft (6). 5. Flat lapping machine for lapping workpieces according to claim. 4, characterized in that it is connected to one on the hub de «Ualaufradee of the first • 0M1J / 0I00 Planetary gear attached additional planetary gear and a cross lead clutch is provided, in which one of the coupling halves the planetary gear (22) of the additional Represents planetary gear, while the second is rotatably arranged on an additional eccentric axis (27) and with is rigidly connected to the workpiece cage " 6, flat lapping machine to carry out the process according to claim 1, including a workpiece cage mounted on a gear to be connected to the sun gear of a tarpaulin tengetriebes with a carrier and a driver which is attached to the hunter axis on which a between the Gear of the workpiece cage and the sun gear arranged Intermediate wheel sits freely, is in kinematic connection, and the gear wheel of the workpiece cage is on an additional axis arranged, which goes through the driver, which is supported on the carrier, characterized in, that the machine is additionally equipped with a disk (46) with an additional axis attached to it, which is coaxial is arranged with the carrier (44), and a differential gear is provided, one axis of which with the carrier (44) and the other is connected to the disc (46) via intermediate gears (41), the additional axis being in the hat of Mitneb **. mers (42) and into a circular arc groove worked into the carrier (44) » 109813/0100