U.S. patent application number 15/710237 was filed with the patent office on 2018-03-29 for grinding machine.
The applicant listed for this patent is KARL HEESEMANN MASCHINENFABRIK GMBH & CO. KG. Invention is credited to Christoph GIESE.
Application Number | 20180085892 15/710237 |
Document ID | / |
Family ID | 59955483 |
Filed Date | 2018-03-29 |
United States Patent
Application |
20180085892 |
Kind Code |
A1 |
GIESE; Christoph |
March 29, 2018 |
Grinding machine
Abstract
The present invention relates to a grinding machine for grinding
a surface of a workpiece, having at least one transport device for
transporting a workpiece in a transport direction through the
grinding machine, and at least one grinding tool (2), wherein the
grinding tool (2) has at least one brush with grinding bristles,
wherein the grinding machine has a leveling unit.
Inventors: |
GIESE; Christoph; (Herford,
DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KARL HEESEMANN MASCHINENFABRIK GMBH & CO. KG |
Bad Oeynhausen |
|
DE |
|
|
Family ID: |
59955483 |
Appl. No.: |
15/710237 |
Filed: |
September 20, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B24B 49/186 20130101;
B24B 9/002 20130101; B24B 29/005 20130101; B24B 53/14 20130101;
B24B 53/005 20130101; B24B 53/04 20130101 |
International
Class: |
B24B 53/04 20060101
B24B053/04; B24B 9/00 20060101 B24B009/00; B24B 29/00 20060101
B24B029/00; B24B 53/00 20060101 B24B053/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 23, 2016 |
DE |
10 2016 117 994.9 |
Claims
1. A grinding machine for grinding a surface of a workpiece,
comprising: at least one transport device for transporting a
workpiece hi a transport direction through the grinding machine; at
least one grinding tool that has at least one brush with grinding
bristles; and a leveling unit.
2. The grinding machine according to claim 1, wherein the leveling
unit has at least one leveling tool for shortening at least some of
the grinding bristles.
3. The grinding machine according to claim 2, wherein the at least
one leveling tool is arranged so as to be displaceable in a
direction perpendicular to the transport direction.
4. The grinding machine according to claim 2 wherein at least one
of the at least one grinding tool and the at least one leveling
tool is arranged so as to be height-adjustable.
5. The grinding machine according to claim 2 further comprising a
multiplicity of disk brushes which revolve along a revolving
contour, and wherein the at least one leveling tool is arranged
adjacent to the at least one transport device.
6. The grinding machine according to claim 2 further comprising a
measuring device for measuring a length of at least some of the
grinding bristles.
7. The grinding machine according to claim 6, wherein the measuring
device is designed to measure the length of the grinding bristles
at different points of the at least one grinding tool, and further
comprising an electrical controller designed to bring the at least
one leveling tool into engagement with the grinding bristles if a
length difference between different bristles exceeds a
predetermined threshold value.
8. The grinding machine according to claim 7, wherein the
predetermined limit value is dependent on the length of the
grinding bristles.
9. The grinding machine according to claim 1 further comprising an
imbalance measuring device for measuring an imbalance of the at
least one grinding tool.
Description
[0001] The invention relates to a grinding machine for grinding a
surface of a workpiece, having at least one transport device for
transporting a workpiece in a transport direction through the
grinding machine, and having at least one grinding tool, wherein
the grinding tool has at least one brush with grinding
bristles.
[0002] Grinding machines of said type have long been known from the
prior art and are used for a wide variety of different surfaces.
For example, it is known for wood surfaces or metal surfaces to be
machined using such grinding tools, for example grinding brushes or
disk brushes, and thus, for example, for metallic components to be
deburred and rounded at the edges, or for visually appealing
surface effects to be generated in the surface of the workpiece. In
particular in the case of grinding brushes being used, these
normally extend over the entire width of the transport device,
which may for example be a conveyor belt. The workpieces to be
machined are normally not adapted to the width of the transport
device, but have an extent in said direction which is smaller than
that of the transport device and thus also smaller than the width
of the grinding brush. This inevitably means that, during the
grinding of the surface of a workpiece, not all of the grinding
bristles of the brush come into contact with the workpiece. In
particular, the grinding tool is normally more heavily loaded in
the central region over the width of the grinding tool than in the
edge regions.
[0003] From the prior art, efforts have been known to be made to
counteract this effect, which leads to more intense wear of the
grinding tool in the center, for example by virtue of the
workpieces to be ground being guided through the grinding machine
at different positions, such that grinding bristles of the brush
which are otherwise not heavily loaded can also come into contact
with a surface of the workpiece. Irregular wear of the grinding
tool, and in particular of the grinding brushes, nevertheless
occurs.
[0004] To be able to grind the desired pattern into the surface of
a workpiece, or in order to specifically avoid particular grinding
patterns and produce a surface which is formed with the least
possible grinding patterns, it is however advantageous, or even
necessary, for the grinding pressure with which the grinding
bristles come into contact with the surface to be temporally and
spatially constant. Otherwise, loading of the surface of the
workpiece with varying intensity would have the effect that it is
not possible to generate homogeneous grinding marks on said
surface. The deburring or rounding of edges of metallic workpieces,
for example, also necessitates that the contact pressure of the
grinding tool on the surface of the workpiece be not only known and
reproducible but in particular temporally and spatially constant.
Therefore, grinding tools in the form of grinding brushes or disk
brushes are nowadays removed from the grinding machine after a
certain operating duration and are either exchanged or for example
sent to the manufacturer of the grinding tools. There, less heavily
worn grinding bristles are shortened in order to ensure that a
homogeneous grinding bristle length is again present on the
grinding brush or disk brush, and thus a homogeneous contact
pressure is again ensured. This is time-consuming and expensive and
leads to relatively long time periods in which the grinding machine
cannot be used. This is the case even if, during the time in which
a grinding tool is dismounted and for example sent away, another
grinding tool is present in the grinding machine.
[0005] The invention is therefore based on the object of further
developing a grinding machine such that it can be used more
efficiently and can be operated with less downtime, and at the same
time the grinding tool can be used for as long as possible.
[0006] The invention achieves the stated object by means of a
grinding machine as per the preamble of claim 1, which is
characterized in that it has a leveling unit.
[0007] A leveling unit is a functional unit within the grinding
machine which, for example in a special operating mode of the
grinding machine, serves to restore the concentricity and the
straightness 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 electronic
controller of the grinding machine. Therefore, with a grinding
machine according to the invention, it is only seldom necessary for
the grinding tool itself, in particular 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 optimum grinding results.
[0008] The leveling unit advantageously has at least one leveling
tool for shortening at least some of the grinding bristles.
[0009] 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
example 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, such that a homogeneous
grinding re-suit 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 the grinding
tool being shortened to different lengths, if this is desired and
advantageous.
[0010] 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
entire width. Here, the leveling tool may be formed as one large
cutting element, for example 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.
[0011] 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 direction. The leveling
tool itself can then be of spatially small form, in particular 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 movable 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 desired length.
[0012] The at least one grinding tool and/or the leveling tool is
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 thicknesses of work-pieces 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 nevertheless also possible for the
leveling tool to be designed to be height-adjustable, as long as
the grinding tool and leveling tool are height-adjustable
independently of one another. 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.
[0013] 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 arrangement of the leveling tool above said brush
roller has proven to be advantageous because the bristles point in
said direction in any case when the brush rotates. However, 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 workpiece, and the axis of rotation about
which the disk brush rotates or is pivoted is perpendicular 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.
[0014] 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 sections 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.
[0015] In a preferred embodiment, the grinding machine has a
measuring device for measuring the length of the grinding bristles.
This may be performed for example contactlessly, in particular by
means of light barriers, or by means of pressure or contact
sensors, which measure whether particular points still come into
contact with the revolving grinding bristles. Here, too, it has
proven to be advantageous for the measuring device to be designed
to measure the length of the grinding brushes 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 device, 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 necessary.
[0016] The predetermined threshold value is advantageously
dependent on the length of the grinding brushes. If the grinding
brushes are already relatively short, for example because they have
been shortened several times, it may be expedient for the
predetermined 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.
[0017] 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.
[0018] 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 the grinding apparatus
and/or the grinding table do not have to be removed from the
grinding machine.
[0019] As is conventional, 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 seldomly. As is conventional, 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
accessible.
[0020] 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 having to be removed from the grinding
machine. The exchange of the transport belt is thereby greatly
simplified. If, for example, 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 grinding belt, such that it is no longer necessary to
remove particles of grinding dust or grinding chips adhering to the
grinding belt. It is thus for example possible for different
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 subsequent use with a different metal
type. With the embodiment of the grinding machine according to the
invention, this no longer has the result that it is no longer
possible 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.
[0021] 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
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 manner
as possible. This may be achieved for example by means of simple
screw connections, which are released for the purposes of
exchanging the transport belt. The number, positioning and type of
fastenings and the installation of the detachably installed
supports 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, because these significantly
co-determine the intensity of the pressure exerted by the grinding
apparatuses on the workpiece and thus also on the transport
belt.
[0022] 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 suctioned away by the suction device, and thus
the contamination and fouling of the interior space of the grinding
machine with grinding dust or grinding chips is reduced.
[0023] 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
refinement, 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.
[0024] The grinding machine advantageously has an extraction
chamber which is arranged below the transport belt and which has a
base which is inclined with respect to the horizontal.
[0025] The grinding machine preferably has a suction device by
means of which a workpiece 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 generally formed
as part of the suction device, though 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 grinding region of the grinding machine and
collected, and can be easily removed.
[0026] 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 encircling
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 arranged only in a
partial region below the transport belt. Said partial region
advantageously 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
5.degree., preferably at least 10.degree., particularly preferably
at least 15.degree., and at most 30.degree., preferably at most
25.degree., 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 extraction 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.
[0027] 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 suctioned out of the
extraction chamber by means of said suction device. The base of the
extraction chamber is consequently inclined toward said suction
device.
[0028] 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 particularly
advantageously coated with an anti-adhesion coating. A polymer or a
mixture 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.
[0029] 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 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 chamber can be moved, such that they/it can
be collected and removed, for example extracted.
[0030] The grinding machine advantageously has multiple transport
belts and multiple suction 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 separate from the
other modules. For this purpose, it is advantageous if each of the
modules, 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
grinding chips or grinding dust is carried through the entire
grinding machine by an excessively long transport belt, and
furthermore, it is made possible for the individual assemblies and
modules to be easily exchanged and dismounted, for example for the
purposes of cleaning, maintenance or exchange.
[0031] 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 apparatus or a grinding
module from the grinding machine.
[0032] 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 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.
[0033] 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 refinement, the device has an electrical
controller which is designed to determine the radius from the
measured distance. 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.
[0034] 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 section 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 notionally 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 surfaces. 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.
[0035] 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 distance 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 difference between the
radius of the inner circle and the radius of the outer circle. In
this way, it is also possible to determine the radius of the inner
circle, which corresponds to the radius to be determined.
[0036] 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
process. 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 measuring slide is displaced in the presence of said
abutment.
[0037] 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.
[0038] A radius determined by means of the device is advantageously
used as a control parameter 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 workpiece 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 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 increased, 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 particular 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 succession.
[0039] It has proven to be advantageous for the grinding machine to
have multiple such devices. In this way, different edges with
possibly different setpoint radii can be measured simultaneously,
and in this way the quality control process can be accelerated.
[0040] 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.
[0041] An exemplary embodiment of the present invention will be
discussed in more detail below on the basis of the appended
drawing. In the drawing:
[0042] FIG. 1--shows a schematic illustration of a part of a
grinding machine according to a first exemplary embodiment of the
present invention.
[0043] FIG. 1 shows a detail of a grinding machine according to an
exemplary embodiment of the present invention. The FIGURE shows the
grinding tool 2, which in this case is in the form of a brush
roller. It has, on its shell surface 4, a multiplicity of grinding
bristles (not illustrated).
[0044] The grinding tool 2 is mounted on two mountings 6, and is
driven by means of a motor 8 and a power transmission belt 10. Said
grinding tool is rotatable about a longitudinal axis which runs
through the mountings 6.
[0045] Above the grinding tool 2, there is situated a leveling tool
12 which, in this case, is a small rotating disk with a relatively
sharp edge. Said leveling tool is arranged on a holder 14, in which
a drive 16 for the leveling tool 12 is also situated. In the
exemplary embodiment shown, the leveling tool 12 is, with the
holder 14, movable to the left and to the right along a linear
guide 18. In this way, said leveling tool can reach every point
along the width of the grinding tool 2.
[0046] In the exemplary embodiment shown, the grinding tool 2 and
the mountings 6 are mounted in displaceable fashion by a height
adjustment means 20. In this way, a spacing between the shell
surface 4 of the grinding tool 2 and the leveling tool 12 can be
adjusted in continuously variable fashion. An adjustment motor 22
is provided for the height adjustment means 20.
[0047] If the height adjustment means 20 is activated and, for
example in the illustration shown, the grinding tool 2 is raised
relative to the leveling tool 12, and the leveling tool 12 is moved
to the right and to the left by means of the linear guide 18, the
leveling tool 12 comes into contact with the grinding bristles (not
illustrated) situated on the shell surface 4 of the grinding tool 2
and shortens said bristles to the desired length. Owing to the
centrifugal force of the rotating grinding tool, it is ensured
that, in the embodiment shown, all of the grinding bristles are
shortened to the same length.
LIST OF REFERENCE DESIGNATIONS
[0048] 2 Grinding tool [0049] 4 Shell surface [0050] 6 Mounting
[0051] 8 Motor [0052] 10 Power transmission belt [0053] 12 Leveling
tool [0054] 14 Holder [0055] 16 Drive [0056] 18 Linear guide [0057]
20 Height adjustment means [0058] 22 Adjustment motor
* * * * *