CA2980057A1

CA2980057A1 - Grinding machine

Info

Publication number: CA2980057A1
Application number: CA2980057A
Authority: CA
Inventors: Christoph Giese
Original assignee: Karl Heesemann Maschinenfabrik GmbH and Co KG
Current assignee: Karl Heesemann Maschinenfabrik GmbH and Co KG
Priority date: 2016-09-23
Filing date: 2017-09-22
Publication date: 2018-03-23
Also published as: CN107866734A; EP3332912A1; DE102016117992A1; US20180085893A1

Abstract

The present invention comprises a grinding machine for grinding a metallic surface of a workpiece, wherein the grinding machine has - at least one grinding apparatus, - at least one transport belt (2) for transporting the workpiece through the grinding machine, and - at least one suction device by means of which a workpiece lying on the transport belt (2) can be acted on with a negative pressure, wherein the suction device has an extraction chamber (14) which is arranged below the transport belt (2) and which has a base (16) which is inclined with respect to the horizontal.

Description

Gramm, Lins & Partner PATENT- UND RECHTSANWALTE
Karl Heesemann Attorney reference:
Maschinenfabrik GmbH & Co. KG 0359-098 DE-1 Reuterstralle 15 Date:
32547 Bad Oeynhausen 23 September 2016 Germany FR/sb-jho Grinding machine The invention relates to a grinding machine for grinding a metallic surface of a work-piece, wherein the grinding machine has at least one grinding apparatus and at least one transport belt for transporting the workpiece through the grinding machine.
Grinding machines of said type are nowadays known from the prior art and are used with a wide variety of grinding apparatuses for the machining and grinding of metallic surfaces. The grinding apparatus may have disk brushes or brush rollers or revolving grinding means, such as for example grinding belts or abrasive papers.
Oscillating grinders may also be used.
Grinding machines are used for example for rounding off and deburring punched or cut edges of metallic workpieces. They are however also used for refining and im-proving the appearance of metallic surfaces; for example, by means of grinding ma-chines are correspondingly used in the production of brushed steel surfaces or brushed aluminum surfaces. In particular if it is sought not only for the surface to be visually improved but also for significant abrasion of material from the workpiece to be realized by means of the grinding apparatus of the grinding machine, it is the ge-neric approach to use grinding machines which have a suction device. In order to make it possible for workpieces of different size and with different dimensions to be machined as quickly as possible one after the other on the same grinding machine, the transport belt is not equipped with fastening means for fixing the workpiece to be machined to the transport belt. Instead, the suction device is provided, by means of which a workpiece lying on the transport belt can be acted on with negative pressure and thus held fixed on the transport belt. This is advantageous in particular if a high pressure and a high force are exerted on the workpiece by the grinding apparatus, ,

- 2 -which can have the effect that the workpiece is displaced on the transport belt. To prevent this, the suction force is applied to the workpiece.
Often, a grinding machine is used for machining different workpieces which have me-tallic surfaces composed of different metals. This results in increased outlay for cleaning, because it is necessary to prevent mixing of grinding chips, and material abraded by grinding, composed of different metals.
The invention is therefore based on the object of further developing a grinding ma-chine such that even different metals can be machined using a single grinding ma-chine without great outlay.
The invention achieves the stated object by means of a generic grinding machine as per the preamble of claim 1, which is distinguished by the fact that the grinding ma-chine has an extraction chamber which is arranged below the transport belt and which has a base which is inclined relative to the horizontal.
The grinding machine preferably has a suction device by means of which a work-piece lying on the transport belt can be acted on with a negative pressure, wherein the extraction chamber is part of the suction device. The extraction chamber is gen-erally formed as part of the suction device, though in the context of the present inven-tion may also be used without the possibility of acting thereon with negative pressure.
The grinding chips to be discharged or the grinding dust are/is then, by means of the inclined base and the inherent weight of the chips or of the dust, led out of the grind-ing region of the grinding machine and collected, and can be easily removed.
An extraction chamber arranged below the transport belt is in this case arranged preferably only under that part of the transport belt on which the workpieces are transported through the grinding machine. The transport belt is generally an encir-cling endless belt which forms a closed contour. The extraction chamber is preferably arranged within said contour, as far as possible directly below the transport belt. For numerous embodiments, it is sufficient here for the extraction chamber to be ar-ranged only in a partial region below the transport belt. Said partial region advanta-

- 3 -geously corresponds to the region in which the grinding apparatus is arranged above the transport belt. This is the region in which grinding chips and grinding dust are formed, which are to be discharged through the extraction chamber. The base of the extraction chamber advantageously encloses an angle of at least 50, preferably at least 10 , particularly preferably at least 15 , and at most 30 , preferably at most 25 , particularly preferably at most 20 , with the horizontal. It has proven to be particularly advantageous if the base of the extraction chamber is inclined perpendicular to the transport direction along which the workpiece can be transported by the transport belt. This means that the workpiece is transported along the transport direction, and the inclination extends to the right or to the left therefrom. Grinding dust and grinding chips that are formed as a result of the machining of the surface of the workpiece by means of the grinding apparatus can pass through holes or openings provided in the transport belt into the extraction chamber, from where they can be extracted.
This is further simplified, and made more efficient, by means of the inclined base of the ex-traction chamber. In this way, the remaining fouling of the grinding machine with grinding dust and grinding chips from a metal is considerably reduced, or ideally eliminated entirely.
The extraction chamber is advantageously connected or connectable, at the lower end of the base, to a suction device. Grinding dust and grinding chips can be suc-tioned out of the extraction chamber by means of said suction device. The base of the extraction chamber is consequently inclined toward said suction device.
The transport belt is advantageously coated with an anti-adhesion coating. The inner side of the extraction chamber, or at least the base of the extraction chamber, is par-ticularly advantageously coated with an anti-adhesion coating. A polymer or a mix-ture of multiple polymers has proven to be advantageous as material for the anti-adhesion coating. In this way, too, the residual contamination and fouling of the transport belt and of the suction device, in particular of the extraction chamber, are reduced, and thus the outlay for cleaning is also reduced.
The base of the extraction chamber may preferably also be mechanically animated, that is to say in particular caused to vibrate. This may involve regular vibrations, such ,

- 4 -as for example sound waves, or individual, regularly or irregularly repeating shocks.
In this way, chips or dust that have/has collected on the base of the extraction cham-ber can be moved, such that they/it collects and can be removed, for example ex-tracted.
The grinding machine advantageously has multiple transport belts and multiple suc-tion devices, wherein the suction devices each have an extraction chamber with an inclined base. If the grinding machine is equipped with multiple grinding apparatuses, which may be of different or identical design, it has proven to be advantageous for each of the apparatuses to be arranged in a grinding machine module, which can be exchanged or removed from the grinding machine separately, and in a manner sepa-rate from the other modules. For this purpose, it is advantageous if each of the mod-ules, which may for example have one or two grinding apparatuses, has a dedicated transport belt which is responsible only for transporting the workpiece within the grinding machine module. In this way, firstly, a situation is prevented in which grind-ing chips or grinding dust is carried through the entire grinding machine by an exces-sively long transport belt, and furthermore, it is made possible for the individual appa-ratuses and modules to be easily exchanged and dismounted, for example for the purposes of cleaning, maintenance or exchange.
The at least one transport belt is advantageously exchangeable without the grinding apparatus having to be removed. For this purpose, it is for example possible for a housing, which surrounds the grinding apparatuses, of the grinding machine to be opened. After any supports that may be present are removed, which supports hold the transport table, which has the transport belt, in position, have been removed, the transport belt can be removed. For this purpose, it is for example necessary for a tensioning device, which is responsible for imparting an adequate tension to the transport belt, to be released. The grinding belt can then be easily removed, without the need for dismantling the grinding machine entirely or for removing a grinding ap-paratus or a grinding module from the grinding machine.
The grinding machine preferably has a housing in which the grinding apparatus is arranged, wherein the transport belt is removable from the grinding machine, wherein

- 5 -the grinding apparatus and/or the grinding table do not have to be removed from the grinding machine.
Conventionally, the transport belt is not subjected to unduly heavy loads, such that a change of the transport belt during the operation of a grinding machine is a service action that has to be performed only seldom. Conventionally, the grinding table and possibly additionally the grinding apparatus, that is to say the grinding means itself, must be removed from the housing of the grinding machine. The grinding table must subsequently be dismantled to such an extent that the transport belt is made acces-sible.
By means of this embodiment of the grinding machine, it is now made possible for the transport belt to be exchanged and removed from the grinding machine without the grinding apparatus and/or the grinding table being removed from the grinding machine. The exchange of the transport belt is thereby greatly simplified. If, for ex-ample, it is the intention for metallic surfaces composed of different metals to be ground one after the other, it is now possible, rather than the often cumbersome and time-consuming cleaning of a transport belt, to simply exchange the respective grind-ing belt, such that it is no longer necessary to remove particles of the grinding dust or the grinding chips adhering to the grinding belt. It is thus for example possible for dif-ferent transport belts to be provided for different metals, which transport belts can be inserted into the grinding machine in accordance with the desired metal type to be ground. As an alternative to this, it is self-evidently also possible for a removed transport belt to be cleaned with the required care in order to be made ready for sub-sequent use with a different metal type. With the embodiment of the grinding ma-chine according to the invention, this no longer has the result that it is no longer pos-sible to grind workpieces during said period of cleaning of the transport belt. Rather, one of the transport belts can be cleaned while another transport belt is used in the grinding machine.
The housing preferably has an opening flap which can be placed into an open state and into a closed state, wherein the transport belt is accessible when the opening flap is situated in the open state. The opening flap is advantageously a door or a , ,

- 6 -double door which is arranged such that the housing can be easily opened. When the housing is open, that is to say when the opening flap is situated in the open state, the transport belt can be easily removed from the grinding machine. The grinding table is advantageously fastened to at least one detachably installed support. In particular in the case of relatively large grinding machines or grinding modules, which possibly have more than one grinding apparatus, it is advantageous for the grinding table to be secured by means of at least one support on both sides of the transport belt. On the side on which the transport belt is accessible for example after the opening of the opening flap, it is advantageous if the support can be detached in as simple a man-ner as possible. This may be achieved for example by means of simple screw con-nections, which are released for the purposes of exchanging the transport belt. The number, positioning and type of fastenings and the installation of the detachably in-stalled support are in this case dependent on the size of the grinding machine, on the number of grinding apparatuses used, and on the nature of the grinding process, be-cause these significantly co-determine the intensity of the pressure exerted by the grinding apparatuses on the workpiece and thus also on the transport belt.
The grinding machine advantageously has a suction device by means of which a workpiece lying on the transport belt can be acted on with a negative pressure. In this way, firstly, a holding force on the workpiece is increased, such that, even in the case of relatively high forces being exerted on the workpiece by the grinding apparatus, the workpiece cannot slip or move along the transport belt. Secondly, it is achieved that grinding chips or grinding dust can be extracted by the suction device, and thus the contamination and fouling of the interior space of the grinding machine with grind-ing dust or grinding chips is reduced.
The grinding machine preferably has multiple grinding modules which each have at least one grinding apparatus and one transport belt. Here, it is advantageously the case that each grinding module can be removed from the grinding machine, and for example replaced with another module, separately. In a preferred embodiment, each module has at least one opening flap, particularly preferably a door, by means of which a part of the housing belonging to the module can be opened, whereby the transport belt is made accessible.

- 7 -The grinding machine advantageously has a grinding tool or grinding apparatus, with at least one brush with grinding bristles, and a leveling unit. A leveling unit is a func-tional unit within the grinding machine which, for example in a special operating mode of the grinding machine, serves to restore the concentricity and the straight-ness of the grinding tool, in particular of a brush roller. This special operating mode may be present for example in the form of a predetermined program stored in an electronic data memory, which program can be accessed and executed by an elec-tronic controller of the grinding machine. Therefore, with a grinding machine accord-ing to the invention, it is only seldom necessary for the grinding tool itself, in particu-lar the brush roller, to be removed from the grinding machine. This is necessary only when the brush roller has to be fully exchanged. If it is identified that the contact pressure of the grinding tool is no longer constant over the width of the brush roller or over the spatial extent of individual disk brushes, the special operating mode of the grinding machine is for example initiated manually. In this case, the concentricity and the straightness of the brush roller are restored by means of the leveling unit. This can be performed within a few minutes, such that, after the end of this time period, when the program stored for example in the electronic data memory has been fully executed, the grinding machine is again fully ready for use and provides virtually op-timum grinding results.
The leveling unit advantageously has at least one leveling tool for shortening at least some of the grinding bristles.
During grinding using the grinding machine, individual grinding bristles of the grinding tool are more heavily loaded than others, and in particular wear more intensely, such that they have for example a shorter length than grinding bristles arranged for exam-ple at the edge of the grinding tool. To be able to ensure an optimum grinding result, it is now advantageously the case that all grinding bristles of the grinding brush, in particular of the brush roller, are shortened to one length, in order that a homogene-ous grinding result is achieved. It is self-evidently also possible for a non-homogeneous length of the individual grinding bristles relative to one another to be set by means of the leveling unit, by virtue of grinding bristles in different regions of

- 8 -the grinding tool being shortened to different lengths, if this is desired and advanta-geous.
The leveling tool may for example be composed of a multiplicity of cutting elements which are for example arranged over the width of the grinding tool and which can thus shorten the grinding bristles of the grinding means simultaneously over the en-tire width. Here, the leveling tool may be formed as one large cutting element, for ex-ample a blade or shear which extends over the entire width, or may be composed of a multiplicity of different individual elements arranged adjacent to one another, by means of which it is then possible for different lengths of the grinding bristles to be set at different points of the grinding tool.
As an alternative to this, it has proven to be advantageous for the leveling tool to be arranged so as to be displaceable in a direction perpendicular to the transport direc-tion. The leveling tool itself can then be of spatially small form, and thus formed with a relatively low inherent weight, such that the outlay in terms of apparatus required for the leveling unit in a grinding machine of said type is considerably reduced. In particular in the case of a brush roller, it is advantageous if the leveling unit is mov-able in a direction perpendicular to the transport direction, that is to say from left to right and vice versa in a grinding machine, and can thus move to any point over the width of the brush roller. Since the brush roller can be set in rotation in any case, it is possible in this way for all of the bristles of the brush roller to be shortened to the de-sired length.
The at least one grinding tool and/or the leveling tool are preferably arranged so as to be height-adjustable. In numerous known grinding machines, the grinding tool is height-adjustable in any case in order to be able to make the spacing between the grinding tool and the transport device variable and thus adjustable to different thick-nesses of workpieces to be machined. In this case, it is advantageous if the leveling tool is formed so as not to be height-adjustable relative to the transport device, such that a height adjustment of the grinding tool simultaneously results in a change in the spacing between the grinding tool and the leveling tool. It is self-evidently neverthe-less also possible for the leveling tool to be designed to be height-adjustable, as long

- 9 -as the grinding tool and leveling tool are height-adjustable independently of one an-other. Only in this way can the spacing be changed and thus the length to which the grinding bristles can be shortened by the leveling tool adjusted.
The grinding tool preferably has a multiplicity of disk brushes which run in encircling fashion along an encircling contour, wherein the at least one leveling tool is arranged adjacent to the transport device. If the grinding tool has a brush roller, the arrange-ment of the leveling tool above said brush roller has proven to be advantageous be-cause the bristles point in said direction in any case when the brush rotates.
How-ever, if disk brushes are used, the situation is different. In the case of a disk brush, it is generally the case that all of the grinding bristles are directed toward the work-piece, and the axis of rotation about which the disk brush rotates or is pivoted is per-pendicular to the transport plane of the transport device. In this embodiment, too, it is possible for the leveling tool to be arranged above the disk brushes. In this case, it would be necessary, if the special operating mode of leveling is implemented, for the orientation of the disk brushes to be changed, and for the grinding bristles of the disk brushes to be oriented in the direction of the leveling tool. Although this is possible, it results in increased outlay in terms of apparatus and technical equipment.
A structurally more simple solution is possible if the disk brushes, which in addition to the rotation about their axis of rotation also revolve on a revolving contour, are in this case also moved in a region adjacent to the transport device, such that there are sec-tions of the revolving contour in which the disk brushes and the grinding bristles of the disk brushes cannot come into contact with a workpiece situated on the transport device. The at least one leveling tool can be arranged in a particularly straightforward and space-saving and thus technically cumbersome manner in said regions, in which for example reversal points and curves of the revolving contour are situated.
In this case, it is advantageous for multiple leveling tools to be arranged on both sides of the transport device.
In a preferred embodiment, the grinding machine has a measuring device for meas-uring the length of the grinding bristles. This may be performed for example contact-lessly, in particular by means of light barriers, or by means of pressure or contact

- 10 -sensors, which measure whether particular points still come into contact with the re-volving grinding bristles. Here, too, it has proven to be advantageous for the measur-ing device to be designed to measure the length of the grinding bristles at different points of the grinding tool. This means in particular that the length of the grinding bristles can be measured at different positions over the width of the grinding tool. The grinding machine furthermore has an electrical controller which is designed to bring the leveling tool into engagement with the grinding bristles and thereby shorten the bristles if a length difference between different bristles exceeds a predetermined threshold value. If, on the basis of the measurement results from the measuring de-vice, the electrical controller identifies for example that a length difference between the length of the bristles in the central region of the grinding brushes and the bristles in the outer region of the grinding brush exceeds a predetermined threshold value, the electrical controller can automatically activate or initiate the operating mode of leveling, and thus ensure that the leveling tool is brought into engagement with the respective grinding bristles, such that the length difference between the individual bristles is reduced or adjusted to the desired dimension. As an alternative to this, the electrical controller may also trigger a display or alarm device such that an operator of the grinding machine recognizes that shortening of the grinding bristles is neces-sary.
The predetermined threshold value is advantageously dependent on the length of the grinding brushes. If the grinding brushes are already relatively short, for example be-cause they have been shortened several times, it may be expedient for the prede-termined threshold value to be selected to be relatively low, in order to achieve that a relative change in length remains as small as possible. However, if the length of the brushes is still relatively large, for example in the case of a brush roller which has been newly inserted into the grinding machine, larger length differences are by all means tolerable.
The grinding machine preferably has a device for determining a radius of a contour of an object with an at least circular-segment-shaped cross section, which device has two abutment surfaces for the abutment of the object and at least one measuring slide, wherein the abutment surfaces are arranged at right angles with respect to one

-11 -another and the measuring slide is arranged so as to be displaceable along an angle bisector of said right angle, such that the measuring slide is displaceable by virtue of the object being placed against the two abutment surfaces.
The device advantageously has a measuring device for measuring the distance by which the measuring slide is displaced when the object is placed against the two abutment surfaces. In a particularly advantageous embodiment, the device has an electrical controller which is designed to determine the radius from the measured dis-tance. The device preferably has a display device which is designed to display the radius and/or the distance by which the measuring slide has been displaced.
This embodiment is based on the realization that an object with a circular-segment-shaped or circular cross section which is arranged with the contour of said cross sec-tion against the two abutment surfaces arranged at right angles with respect to one another displaces the measuring slide. The circular-segment-shaped or circular cross section may in this case at least notionally be approximated by a circle with a radius which is to be determined by the device. Here, said circle forms the inscribed circle or inner circle with respect to a square, one corner of which is formed by the point at which the two abutment surfaces bear against one another. Said square may notion-ally be circumscribed by a circumscribed circle or outer circle, the central point of which is consequently situated at the central point of the inscribed circle and which runs through the contact point, that is to say the "corner", of the two abutment sur-faces. Here, the statements relating to circles, squares or points relate in each case to the cross section through the object which is inserted into the device according to an exemplary embodiment of the present invention.
The difference between the radius of the inscribed circle or inner circle and the radius of the circumscribed circle or outer circle corresponds in this case exactly to the dis-tance by which the measuring slide still stands out from the corner formed by the two abutment surfaces. If it is known how far the measuring slide stands out from said corner without an inserted object, it is easily possible to calculate the size of the dif-ference between the radius of the inner circle and the radius of the outer circle. In this

- 12 -way, it is also possible to determine the radius of the inner circle, which corresponds to the radius to be determined.
The device is advantageously arranged so as to determine the radius of an edge of the workpiece. This is advantageously performed after the workpiece has run along the grinding tool itself and interacted therewith, that is to say after the grinding proc-ess. By means of the very simple device for measuring the radius, it is possible in a particularly simple and nevertheless reliable and reproducible manner to determine whether the desired grinding result has been achieved, and the radius of the edge of the workpiece meets the legal or other requirements. For this purpose, it is merely necessary for that edge of the workpiece whose radius is to be measured to be placed against the two abutment surfaces of the device. The radius of the edge can be determined in a particularly simple manner from the distance by which the meas-uring slide is displaced in the presence of said abutment.
The grinding machine preferably has an actuator which moves the device against the desired edge of the workpiece. This is advantageously performed fully automatically, such that an intervention by operating personnel is not necessary. For this purpose, it may be advantageous if the grinding machine has a position detection device and/or an orientation detection device, by means of which the position and/or orientation of the workpiece on a transport device of the grinding machine can be identified.
In this way, an electrical controller of the grinding machine can ensure that the actuator, which may for example be a robot arm, particularly preferably a multiply articulated robot arm, moves the device accurately toward, and places the device accurately against, the desired point of the workpiece to be inspected and the required edge.
A radius determined by means of the device is advantageously used as a control pa-rameter or regulation variable in the electrical controller of the grinding machine. In particular if the determined radius does not satisfy the legal or other regulations, or has an excessively large deviation from a predetermined setpoint value, the work-piece can for example be passed through the grinding machine once again, or can be labeled as a reject or as a workpiece for reprocessing. It is furthermore possible, in particular if the determined radius is too small, that is to say the abrasion effected

- 13 -by the grinding machine is not sufficient to achieve the desired setpoint value, for the contact pressure of the grinding tool against the surface of the workpiece to be in-creased, and thus for increased grinding abrasion, and thus a larger radius of the edge, to be achieved in the case of subsequent workpieces. This is expedient in par-ticular if multiple workpieces, in particular a large number of workpieces, which have a surface composed of the same material are to be machined and ground in succes-sion.
It has proven to be advantageous for the grinding machine to have multiple such de-vices. In this way, different edges with possibly different setpoint radii can be meas-ured simultaneously, and in this way the quality control process can be accelerated.
The grinding machine advantageously has an imbalance measuring device for measuring an imbalance of the grinding tool. In this way, too, it can be identified whether some or all of the grinding bristles have to be shortened.
An exemplary embodiment of the present invention will be discussed in more detail below on the basis of the appended drawings. In the drawings:
Figure 1 - shows a schematic illustration of a transport table for a grinding ma-chine, Figure 2 - shows a schematic view of an extraction chamber, and Figure 3 - shows a further schematic view of an extraction chamber.
Figure 1 shows a transport table 1 for a grinding machine according to a first exem-plary embodiment of the present invention. The figure shows a transport belt 2 which is guided over diverting rollers 4 and a tensioning device 6. The transport belt is driven by a motor (not illustrated in Figure 1) and can move a workpiece (not illus-trated) which is situated on the transport belt 2 along a transport direction T.

- 14 -The transport table 1 shown in Figure 1 stands on supports 8 which also support a grinding apparatus (not shown). For this purpose, feet 10 are provided which stand on suspension means 12 and on which a grinding apparatus frame with a grinding apparatus is arranged.
Situated below the transport belt 2 is an extraction chamber 14 which has an inclined base 16, the inclination of which runs perpendicular to the transport direction T. In the exemplary embodiment shown, the base 16 is formed so as to be inclined along a direction perpendicular to the plane of the drawing. In the context of the present in-vention, the extraction chamber 14 is situated below the transport belt 2, even if a return section 18 of the transport belt 2 is situated below the extraction chamber 14.
Figure 2 shows a schematic view of the extraction chamber 14. It is possible to see the inclined base 16, whose inclination, in Figure 2, runs from left to right, and thus perpendicular to the transport direction T. A top side 20 of the extraction chamber 14 is advantageously of open form in order that a negative pressure to be built up within the extraction chamber 14 can be transmitted to the transport belt 2 running there-above, and thus to a workpiece situated on said transport belt.
Figure 3 shows another view of an extraction chamber 14 with the inclined base 16. It can be seen that a height of the extraction chamber 14 is greatest in the central re-gion, and decreases in edge regions 22. Altogether, however, the base 16 is inclined rearward in Figure 3.
Situated within the extraction chamber 14 are strut arrangements 24, which are ad-vantageous in particular in the case of large extraction chambers 14 for the purposes of preventing the transport belt 2 from being sucked into the extraction chamber 14.
In a rear wall 26 of the extraction chamber 14 there is situated an extraction opening 28 to which an extraction device, for example a pump, can be connected, in order to act on the extraction chamber 14, and thus on the transport belt 2 running there-above, with a negative pressure.

- 15 -Figure 1 illustrates load-bearing elements 30 which hold the extraction chamber 14 in position. If the transport belt 2 is to be exchanged, said load-bearing elements 30 must be removed. After the tensioning device 6 has been detached, the transport belt 2 can then be easily removed, without further rearrangement or dismounting of other components of the grinding machine.

- 16 -List of reference designations T Transport direction 1 Transport table 2 Transport belt 4 Diverting roller 6 Tensioning device 8 Support 10 Foot 12 Suspension means 14 Extraction chamber 16 Base 18 Return section 20 Top side 22 Edge region 24 Strut arrangement 26 Rear wall 28 Extraction opening 30 Load-bearing element

Claims

Patent Claims

1. Grinding machine for grinding a metallic surface of a workpiece, wherein the grinding machine has - at least one grinding apparatus and - at least one transport belt (2) for transporting the workpiece through the grinding machine, characterized in that the grinding machine has, below the transport belt, an extraction chamber (14) which has a base (16) which is inclined with respect to the horizontal.

2. Grinding machine according to Claim 1, characterized in that the grinding ma-chine has at least one suction device by means of which a workpiece lying on the transport belt (2) can be acted on with a negative pressure, wherein the ex-traction chamber is part of the suction device.

3. Grinding machine according to Claim 1 or 2, characterized in that the base (16) of the extraction chamber (14) encloses an angle of 5°, preferably at least 100, particularly preferably at least 15°, and at most 30°, preferably at most 25°, particularly preferably at most 20°, with the horizontal.

4. Grinding machine according to Claim 1, 2 or 3, characterized in that the base (16) of the extraction chamber (14) is inclined in a direction perpendicular to a transport direction (T) along which the workpiece can be transported by the transport belt (2).

5. Grinding machine according to one of the preceding claims, characterized in that the extraction chamber (14) is connectable, at the lower end of the base (16), to a suction device.

6. Grinding machine according to one of the preceding claims, characterized in that the transport belt (2) is coated with an anti-adhesion coating.

7. Grinding machine according to one of the preceding claims, characterized in that an inner side, or at least the base (16) of the extraction chamber (14), is coated with an anti-adhesion coating.

8. Grinding machine according to Claim 6 or 7, characterized in that the anti-adhesion coating is composed of a polymer or of a mixture of multiple polymers.

9. Grinding machine according to one of the preceding claims, characterized in that the grinding machine has multiple transport belts (2) and multiple suction devices, wherein the suction devices each have an extraction chamber (14) with an inclined base (16).

10. Grinding machine according to one of the preceding claims, characterized in that the at least one transport belt (2) is exchangeable without the need for the grinding apparatus to be removed.