DE3013204A1 - POLISHING METHOD AND DEVICE - Google Patents

Description

The invention relates to a polishing method and device for polishing hard stones such as marble or Granite in a sequence of work steps.

In general, known polishing machines have a polishing head which is slidably arranged on a bridge is, which bridges a work table for the stones to be polished and transversely to the movements of the head can be moved with respect to the table by means of two longitudinally arranged guide rails. Such an arrangement enables the polishing head to clear the limited surface area between the two Can paint over guide rails. This polishing head essentially has a tool shaft or -Spindle that is rotatably driven to the abrasive tool, which is carried by the spindle, a to enable rotating working movement, by means of which the roughness elevations, which are on the surface of the stone to be polished are located, can be removed. To obtain a modulation of the abrasion force, the tool is often designed to be movable along an axis perpendicular to the work table, and a return spring corrects the displacements of the tool in this axis depending on the more or less large amplitude of the roughness elevations to be removed.

The invention is based on the object of an improved To provide polishing methods and an improved polishing apparatus, with an automatic and continuous sequence of the various work

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steps achieved when polishing hard stones such as marble or granite and thereby a uniform and should be made possible to produce glossy surface of these workpieces. In particular, a successive Use of different tools are made possible, the tool grain size of which is different is to enable a perfect oiling of the surface to be processed.

Furthermore, with the method according to the invention a Correction of the vertical buffing tool movements can be made to make these movements less random to make than the movements generated by a return spring, and to benefit such movements of the tool to the surfaces to be processed and consequently to shorten the working time for polishing.

To solve this problem is according to a method the invention provided that

- a reference level between an invariable horizontal plane and that with the one to be polished Stone in contact with the polishing wheel surface is fixed;

- In compliance with the specified reference level, deviations in level on the surface of the stone to be treated are scanned and the feed speed of the

Polishing wheel is changed immediately in order to correct the mentioned level deviations;

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and

- an automatic tool change depending on the wear of the polishing tool or due to a new episode

of work steps to be carried out will.

Such a method enables all polishing operations to be carried out without human intervention during machining and at the same time to limit the movement of the tool with respect to the stone, because the correction of level deviations due to the fact that the secondary reaction for correcting the level deviations is a modification of the feed speed of the polishing tool If, for example, a roughness elevation causes a level deviation Ad, the feed speed V of the polishing tool is reduced to a feed speed V in such a way that this reduced feed speed V corresponds to the amplitude of the level deviation or that AV = V - V = k .Ad.

This feature of the invention is of particular interest because it enables work to be carried out under constant pressure and, in contrast to the known polishing devices, avoids machining at a point on the stone which is at a distance from the desired polishing surface.
30th

According to a particularly advantageous development of the method according to the invention, the strength or height the wear of the polishing tool measured. If the wear strength Ah of the polishing wheel of the work

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tool is detected, the reference level between an invariable horizontal plane and the surface of the polishing tool, which is in contact with the machined stone is no longer complied with, i _n which it labeled E reference level E to E ¹ = E-Ah is. To find the height E again, it is sufficient to lower the polishing tool by the amount Ah.

In order to achieve perfect polishing, two rotations are expediently impressed on the polishing tool, whereby one of these rotations is eccentric about the axis of the tool.

The invention also relates to a polishing device for carrying out the method described above. Such a polishing device is characterized in that the carriage support

- means for rotating the polishing tool,

- Means for mechanically gripping and releasing the polishing tool,

- Means for straight vertical drive

of the polishing tool,

- Means for measuring a presence on the surface of the stones to be treated Level deviation,

and means for measuring the wear of the polishing tool

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includes and that the table

- Encoder, preferably electronic, which are adjustable on the table for classifying the stones to be processed,

and

- A storage magazine for polishing tools to supply the polishing device

includes.

All these means taken together make one possible automatic sequence of all polishing operations and thus help to the highest degree human Avoid interventions.

It is expediently provided for the automation of the polishing device that an electronic computer with a Memory is provided, which constantly updates its program by the means for measuring a level deviation and adapts information obtained from the means for measuring the wear of the polishing tool, and that said electronic encoder for coordinating the rotary drives of the straight vertical Serve movement and the gripping movement of the polishing tool with the movements of the slide support.

The invention and advantageous details of the invention are shown schematically below with reference to Drawings of an exemplary embodiment explained in more detail with further details. Show it:

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FIG. 1 shows a schematic section through the head of a polishing device according to the invention;

Figure 2 is a perspective, partially broken away View of the head according to Figure 1 and

Figure 3 is a plan view of the head.

As mentioned above, Figures 1, 2 and 3 show schematically the polishing head of a classically designed polishing machine, as mentioned at the beginning. The head is formed by a carriage support 1, the is designed in the form of a double T and by means of a suitable drive on two rails 2a and 2b (in the direction of arrow C in Figure 3) can slide, these rails being parallel above the work area extend in which the stones to be processed are arranged. The ends of the rails are open two supports, not shown, are arranged, the feet of which are movable on two longitudinal guides on the two sides a work table are arranged. Rollers 3 are designed to reduce the frictional forces when moving the To reduce carriage 1 along rails 2a and 2b,

The carriage 1 is equipped on the inside with an extenter sleeve 4 which is rotatable in bearings 5 and is connected to a gear wheel 6 which cooperates with a worm or screw 7 driven by a motor 8. This gear wheel (shown only in FIG. 2) impresses the eccentric sleeve 4 with a movement indicated by the arrow R ₁ in FIG. A cylindrical guide 9 is received in the eccentric sleeve, which enables a straight vertical movement of another cylindrical part 10 in the direction of arrow V (Figures

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1 and 2). To compensate for the eccentricity caused by the rotation of the eccentric sleeve, the Guide 9 can be freely rotated therein by means of the bearings 5 ′ arranged in the inner bore of the sleeve. Furthermore are Slideways 11 provided inside the guide 9 to the rectilinear movement of the cylindrical part in the following way.

A transducer 12, which is on a with the cylindrical Guide 9 supports fixed platform 9a, detected by the linear displacement of the part 10 in the Changes in position caused inside the guide 9 and actuated as a function of these changes in position a pressure medium cylinder 13, the head of which is attached to a plate 10a belonging to part 10 and its lower part are attached to the platform 9a. The extension of the pressure medium cylinder therefore leads to a vertical displacement of the part 10 in the guide 9. To support the pressure cylinder 13 on the platform 9a and to control the rotation of this platform is a crankshaft mechanism 14 provided between the platform 9a and the carriage support. This mechanism enables the Simulation of the circular movement which is impressed on the guide 9 by rotating the eccentric sleeve 4.

To accomplish the actual polishing processes by means of a polishing wheel M on at least one stone P, a power transmission spindle 15 is arranged in part 10, which thus plays the role of power transmission. The plate 10a on the part 10 carries a motor 16, the output shaft of which carries a belt pulley 17, which drives another belt pulley 19 on the spindle 15 via a belt 18 and thus sets it ^{in rotation about its axis XX 1} ", like this

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is indicated by the arrow R ^ (Figures 1, 2 and 3).

According to an advantageous feature of the invention, the spindle has a gripping mechanism for gripping of the polishing wheel carrier or tool 20. This mechanism is formed by a pair of pliers 21 in Is movable in the longitudinal direction in a bore in the spindle 15. The lower end of the pliers 21 is with Jaws 22a and 22b are provided, which sit in correspondingly shaped receptacles 23a, 23b. When the pliers is operated in the direction indicated by arrow F, the jaws 22a, 22b move into the cavities 23a and 23b, thus releasing the polishing wheel carrier which, due to the force of gravity, is released from the spindle 15 is released. To hold the tool in the spindle 15, it is sufficient to reverse the process described above ·

To the displacements of the pliers 21 in the spindle 15 to control, a pressure cylinder 24 is provided, which at the upper end of the spindle on the pliers 21 in the direction indicated by the arrow F, while a spring 24 acts on the pliers in the opposite direction Senses to the arrow F acts. The pad carrier's mechanical gripping device is only shown and described in their basic structure, with the necessary accessories such as guide rings, which must be carefully adjusted by a specialist are left aside. The same applies the unit that carries the polishing head.

In summary, it should be noted that the polishing wheel M, its abrasive grains in direct contact with the stone P to be worked on, to the following

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Movements is capable of:

- to a rotary movement R ₁ about the axis X ₁ X ^1. , of the gear wheel 6,

- to a rotary movement R_ about the axis X "X", where this rotary movement is transmitted through the spindle 15,

- and to a vertical translational movement V, which is caused by the periodic movements of the Part 10 in the interior of the guide 9 are defined.

These three movements are also superimposed on the back and forth movement of the slide support 1 and the associated one Polishing pad M.

The lower part of the power transmission 19 comprises a horizontal plate 10b which has a sensor or scale to measure the amount or thickness of wear of the polishing wheel M carries. To this end, the probe includes a movable organ, which is indicated by the arrow A and is supported on the stone P. if the polishing wheel M is worn away by a certain amount of wear, the movable organ reports this to the Example of an electronic computer that causes the tool 20 to be replaced.

This tool change is carried out in the following way 0:

In a first step, the slide support 1 becomes a storage magazine for polishing tools 27 proceed, with this storage magazine in the area of the

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/ is.

Work table is arranged, whereupon the polishing wheel carrier 20 via an empty receptacle 27a of the Storage magazine is positioned.

In a second step, the part or housing 10 lowers the polishing tool 20 into the aforementioned receptacle, and the pressure medium cylinder 24 is actuated to release the tool into the receptacle 27a.

In a third step, the part or housing 10 is lifted again, and the carriage 1 over a another receptacle 27b is positioned in which a not yet used polishing tool that is identical to the first-mentioned polishing tool is included.

In a fourth step, the part 10 is in the receptacle 27b is lowered and the pressure medium cylinder 24 is no longer actuated, in such a way that the spring 25 relaxes and the jaws 22a and 22b of the pliers 21 the new polishing tool 20 in the spindle 15 to grab.

In a fifth and final step, the part is raised again and the slide support 1 is attached to it Return to the starting point where the wear of the polishing wheel of the first polishing tool was determined had been.

As explained at the beginning, the coordination of the movement of the polishing machine described above is carried out by one controlled by a memory equipped electronic computer, the program of which adapts itself as follows:

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a reference level E is fixed between the surface of the polishing pad M, which is in contact with the stone P, and an invariable horizontal plane, for example the platform 9a _f. This reference level E is maintained during all polishing operations. If during the revolutions of the polishing wheel M, the sensor 26 detects a wear strength Ah of the polishing wheel that does not yet require replacement, the pressure cylinder 13 is actuated in such a way that the part 10 is lowered by a height Ah to the reference level E between the surface of the To restore the grinding wheel M in contact with the stone P and the platform 9a.

If during the revolutions of the polishing wheel M a level deviation Ah, for example a roughness, is found on the surface of the stone P, part 10 experiences the same displacement Ad, which is registered at the measuring transducer 12. The latter informs the computer, which on the one hand the deviation Ad corrected by actuating the pressure medium cylinder in which it lowers the part 10 by the amount Ad and thus restores the reference level E and, on the other hand, the feed rate V des Slide 1 reduced so that the new speed V is slow enough to remove the roughness, which caused the level deviation Ad.

The periodic movements of the carriage 1, which generated by the electronic encoders placed on the work table, and the various Sequences of work steps are not described because they do not contribute anything to an understanding of the invention.

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Claims (11)

PATENT LAWYERS DR KADOR & DR. KLUNKER K 12928 / 7h Establishments
BERNAT-SAULIERE, SA
74, Rue du Rey, 81100 CASTRES, France Polishing method and apparatus Claims (1 .y 'polishing method for polishing hard stones like Marble or granite in a sequence of work steps, characterized in that - a reference level between an invariable horizontal plane and the polishing wheel surface in contact with the stone to be polished is permanently set; - in compliance with the specified reference ni veaus level deviations on the surface of the stone to be treated are scanned and the speed of advance of the polishing pad is changed instantaneously to the above To correct deviations in level; and - an automatic tool change depending on 030043/0801
ORIGINAL INSPECTED 301320 - y- • S from wear of the polishing tool or due to a new sequence of tasks to be carried out Work steps is carried out. 2. The method according to claim 1, characterized in that the wear strength of the polishing tool is measured and that the position of the polishing tool with respect to the reference level as a function is corrected by the degree of wear. 10 3. The method according to claim 1 or 2, characterized g e mark e rejects that polishing tool at the same time two rotary movements are impressed, one of which is an eccentric rotation around the axis of symmetry of the polishing tool is. 4. Polishing device for performing the method according to one of claims 1 to 3 with a carriage support which is slidable on a bridge that is displaceable in the direction transverse to the movement of the carriage is movable, and with a work table on which the stones to be polished are arranged are, characterized in that the slide support - Means (15-19) for rotating the polishing unit tool (20), - Means (21, 22,24,25) for mechanical gripping and releasing the polishing tool (20), - Means (13) for the rectilinear vertical drive of the polishing tool (20), - Means (26) for measuring a pre- 020043/0801 existing level deviation, - and means (26) for measuring the wear the polishing tool (20), 5 includes and that the table - Encoder preferably electronic type, which can be regulated on the table to classify the stones to be processed are arranged, and - A storage magazine (27) for polishing tools (20) for supplying the polishing device includes. 5. Polishing device according to claim 4, characterized in that the means for rotationally driving the polishing tool (20) comprise a spindle (15) which is rotatably driven by a motor _{about its vertical axis (X 2} X ¹ _2). 6. Polishing device according to claim 4 or 5, characterized in that the means for Mechanical gripping of the polishing tool in a longitudinal bore through the rotationally driven spindle (15) have extending pliers (21) / at their lower End of jaws (22a and 22b) for gripping the polishing tool (20) and a pressure cylinder at the upper end (24) or the like. Is arranged which, against the action of a spring (25), exerts pressure on the pliers down can exercise. 7. polishing device according to one of claims 4 to 6, 030043/0801 characterized in that the means for driving the polishing tool vertically in a straight line (20) one along a vertical axis in a cylindrical one carried by the carriage support Have guide (9) movable power transmission (10). 8. polishing device according to one of claims 4 to 7, characterized in that the means for sensing a level deviation in the surface a stone to be treated comprise a sensor (12), the linear displacements between the Power transmission (10) and its guide (9) detected. 9. polishing device according to one of claims 4 to 8, characterized in that the means for correcting a level deviation in the surface of a stone have a pressure medium cylinder (13) which between a fixed horizontal plate (10a) of the power transmission (10) and one with the guide (9) connected horizontal plate (9a) is arranged. 10.Polishing device according to one of claims 4 to 8, characterized in that the means for measuring the wear of the polishing tool (20) comprise a measuring scale (26) which is connected to the lower part (10b) of the power transmission (10) and in Is in contact with the surface of the stone to be polished. 11. Polishing device according to one of claims 4 to 10, characterized in that the means 030043/0801 to drive the spindle (15) comprise an eccentric sleeve (4), which are arranged between the guide (9) and the slide support (1) and are Helical gear (6,7) can be driven. 5 ^. Polishing device according to one of claims 4 to 11, characterized in that an electronic computer is provided with a memory is that his program is constantly being updated by the means (12) for measuring a level deviation and from the Adapts means (26) for measuring the wear of the polishing tool (20) received information, and that said electronic encoder for coordinating the rotary drives (4,15) of the straight vertical movement and serve for the gripping movement of the polishing tool (20) with the movements of the carriage support (1). 030043/0801