DD200721A1 - PROCESS NUMBERING TREATMENT OF SPROEDHARTEN SURFACES - Google Patents

Abstract

The invention relates to a method for processing sproedhaft surfaces, in particular for grinding optical surfaces. When grinding such surfaces the effectiveness should be increased. For this reason, a time-effective method was to provide, in which the required roughness depth is largely independent of the grain size of the grinding tool variable and in particular finely adjustable. According to the invention, the tangential movement between the workpiece and the tool is additionally superimposed by a preferably normally directed component of motion whose frequency and amplitude of movement can be adjusted. figure

Description

Title of the invention

Method for processing brittle surfaces.

Field of application of the invention

The invention relates to a method for grinding brittle surfaces, in particular optical surfaces, with a tangential relative movement between the surface to be treated and a tool with bonded grain.

Characteristic of the known technical solutions

Thus, methods are known (e.g., DE-OS 2 651 293) for grinding surfaces with a bonded core tool. This results in a tangential relative movement between the tool and the workpiece, regardless of whether the tool is moved linearly or, for example, circular with respect to the workpiece with the surface to be treated. The grain of the tool exerts on the surface of a removing effect in the direction of movement of the tool. The clearing action on the particles removed from the surface likewise takes place in the direction of the relative movement taking place between the tool and the workpiece.

In these grinding processes, the minimum achievable surface roughness of the surface is dependent, inter alia, on the particle size of the tool,

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i.e. If the surface roughness is to be reduced to certain very small words, the surface must be filled with tools of a smaller grain size. As a result, the lateral and operating costs due to the tool change are relatively high and the effectiveness of the grinding or polishing process low,

The Abtragsprczeß in the machining of workpieces is significantly influenced by the removal of abgespanten material from the place of action »The chip-forming and the transporting Richtungskofflponente are substantially equal and directed tangentially to the workpiece surface, i. The Diaraantkcrn outstanding from the binding pushes a constantly expanding glasspan in front of it, which leads very quickly to blockage of the chip space and thus to the separation of the workpiece and the tool, especially with small diamond core sizes. This creates the impression of a "blunt" tool. If there is insufficient rinsing and cooling, overheating of the effective gap occurs very quickly and thus destruction or damage to the tool and workpiece. The use of tools of smaller grain size for fine machining also leads due to the small grain gaps easily to blockages, so that the replacement or cleaning clogged tools affects the effectiveness of manufacturing each.

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Object of the invention

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The aim of the invention is to increase the effectiveness, in particular the reduction of the time and effort technical effort.

Explanation of the essence of the invention; The invention has for its object to provide a side-effective method for surface treatment, in which the required surface roughness is highly independent of the grain size of the grinding tool feasible and in particular finely adjustable. ,

This object is achieved in a method for processing brittle-hard surfaces, in particular optical surfaces, with a tangential relative movement between the surface to be treated and a grinding tool with bound and tangentially acting grain with respect to the present invention, that the tangential relative movement between the • surface and deta grain of the grinding tool in addition a component of motion substantially normal to the surface is impressed with preferably continuously or in steps adjustable amplitude and / or movement amplitude.

According to the invention executes the W _e rkzeugkorn of preferably directed normal vibrations applied destructive to the workpiece surface and knock out from this surface splitter, which are transported away by the tangential Bewegungskompcnente "By influencing the characteristics of this particle vibrations, the out striking effect of the grain can be controlled.

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With the invention are thus the active components of the tool with respect. Separation and removal of workpiece particles both temporally and directionally separable, ie, in contrast to the known prior art, the chipping and transporting 'effect of the diamond grain depending on the choice of the mentioned characteristics and cutting parameters more or less in a laterally and directionally separate effect of Stcßanteil (fragmentation) and Räumanteil (removal).

The ventilation of the effective gap, which takes place during the respective divergent movement, prevents excessive accumulation of chipped material in the chip space, promotes rinsing and coolant ingress (additional material transport), the formation of longer scratches (grinding marks) largely avoided, which are more or less inclined in direction The normal directed butting component of the bonded grain acts just like the working edge of a rolling loose core.

With the choice of the frequency and the amplitude and the other cutting parameters, both the depth of action and the impact density of the impacting grain can be influenced within wide limits, with emphasis on high through the appropriate choice of certain ratios of immersion depth, free lift and impact density of the oscillating grain Abtrag or good smoothing set or both can be optimized to each other.

By the possible choice of the immersion depth of the impacting grain, the effect of the bonded grain on the material surface is largely independent of the Absclutgröße the diamond used for processing kcrngröße.

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With a relatively coarse-grained tool used in the interest of time-saving pre-machining, both rough machining (maximum chip removal rate) and fine machining (maximum smoothness, minimum roughness) possible,

embodiment

The method according to the invention will be explained in more detail below with reference to an exemplary embodiment shown in the drawing:

The surface 1 of an optical lens 2 is to be coarsely and finely machined in a grinding process. The grinding process is carried out with a grinding tool 3 with bound > grain 4 », wherein the grain 4 has a translatory relative movement to the surface 1 (movement of the grain 4 in xy-3. Ich.tung) and a vibration movement in the normal direction on the surface 1 (z-direction) performs. The translational relative movement may be linear, pendular or circular. Due to the movement component of the grain 4 in the normal direction with a suitable amplitude and frequency of motion, surfaces 5 are knocked out of the surface 1, which particles are transported away in the inter-particle space 6 with the translational movement component. The mentioned Hub- and IPrequenzkenn-. values of the normal component of motion thereby determine. the degree of processing of the grinding process. Thus, with respectively suitable movement characteristic values with the same tool or grain 4, both a high machinability for the rough grinding process and a small removal (small roughness depth) for the fine processing are possible.

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Here, not only the machining time factor plays a role, but also the fact that with a relatively coarse-grained tool a low roughness depth can be achieved because a coarse-grained tool surface by the large Kornzwischenräutne not so quickly clogged and thus account for maintenance and downtime of the machine. Moreover, the certain necessary speed to be realized for the state of the art for optimum chip generation and removal can be substantially reduced because of the inventively reduced active component of the tangential movement component (groove portion) in favor of the service life of moving bearings.

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Claims (1)

-γ- 232242 jSrfir.d nri ^ s.srtgsr For processing hard surfaces, in particular optical surfaces, with a relative movement between the surface to be treated and a grinding tool with bound and tangentially acting grain, characterized in that the relative movement between the surface and the grain of the grinding tool in addition a movement component is impressed substantially normal to the surface with preferably continuously or in steps adjustable movement amplitude and / or frequency » To this 1 Sa! Ta drawings 3806