U.S. patent application number 15/730786 was filed with the patent office on 2018-05-10 for machine and method for machining workpieces of wood, plastic material and the like.
The applicant listed for this patent is Michael Weinig AG. Invention is credited to Christian Burger, Albrecht Dawidziak, Benjamin Frank.
Application Number | 20180126511 15/730786 |
Document ID | / |
Family ID | 60153031 |
Filed Date | 2018-05-10 |
United States Patent
Application |
20180126511 |
Kind Code |
A1 |
Dawidziak; Albrecht ; et
al. |
May 10, 2018 |
Machine and Method for Machining Workpieces of Wood, Plastic
Material and the Like
Abstract
With the machine, workpieces are machined as they pass through
the machine. At least one of the spindles of the machine is coupled
with an adjusting unit with which the spindle, for producing a
contour on the workpiece, can be adjusted transverse to the
throughfeed direction of the workpiece during workpiece
throughfeed. The adjustment of the adjusting unit is realized as a
function of the advancing speed of the workpiece and/or the
workpiece position upon throughfeed of the workpiece. The adjusting
unit has such a stiffness and/or low clearance and/or positioning
precision that the end products machined from the workpieces after
exiting from the machine can be used without further
post-machining. The end products have such a geometry precision and
surface quality that further post-machining is no longer
required.
Inventors: |
Dawidziak; Albrecht; (Gro
rinderfeld, DE) ; Frank; Benjamin; (Boxberg, DE)
; Burger; Christian; (Tauberbischofsheim, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Michael Weinig AG |
Tauberbischofsheim |
|
DE |
|
|
Family ID: |
60153031 |
Appl. No.: |
15/730786 |
Filed: |
October 12, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B24B 35/00 20130101;
B24B 19/24 20130101; B27C 1/005 20130101; B24B 9/20 20130101; B24B
41/04 20130101; B24B 9/002 20130101; B24B 49/006 20130101; B27C
1/00 20130101; B24B 9/18 20130101; B27M 1/08 20130101 |
International
Class: |
B24B 9/00 20060101
B24B009/00; B24B 9/18 20060101 B24B009/18; B24B 9/20 20060101
B24B009/20; B24B 19/24 20060101 B24B019/24; B24B 41/04 20060101
B24B041/04; B24B 49/00 20060101 B24B049/00; B24B 35/00 20060101
B24B035/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 4, 2016 |
DE |
10 2016 013 408.9 |
Claims
1. A machine for machining workpieces of wood, plastic material,
and the like, the machine comprising: at least one transport path
for workpieces on which the workpieces, during throughfeed of the
workpieces through the machine, are transported in a throughfeed
direction through the machine; tools fixedly seated on spindles and
configured to machine the workpieces during throughfeed of the
workpieces through the machine on the at least one transport path;
an adjusting unit having a first adjusting axis; wherein at least
one of the spindles is coupled with the adjusting unit; wherein the
adjusting unit is configured to perform an adjustment of the at
least one spindle, for producing a contour on the workpieces, in a
direction transverse to the throughfeed direction during
throughfeed of the workpieces through the machine, wherein the
adjustment is carried out as function of an advancing speed of the
workpieces and/or workpiece positions of the workpieces along the
at least one transport path during throughfeed; wherein the
adjusting unit has such a stiffness and/or low clearance and/or
positioning precision that end products machined from the
workpieces, when exiting from the machine, can be used without
further post-machining.
2. The machine according to claim 1, wherein a rotary speed of the
at least one spindle is adjustable at all times during throughfeed
of the workpieces through the machine as a function of the
advancing speed and the contour of the workpieces such that a knife
mark of the tool fixedly seated on the at least one spindle is
maintained constant.
3. The machine according to claim 1, wherein the adjusting unit is
free of clearance.
4. The machine according to claim 1, wherein the adjusting unit is
a linear drive.
5. The machine according to claim 1, wherein the adjusting unit is
a ball screw drive.
6. The machine according to claim 1, wherein the adjusting unit has
a second adjusting axis.
7. The machine according to claim 6, wherein the first and second
adjusting axes of the adjusting unit are positioned at a right
angle relative to each other.
8. The machine according to claim 1, further comprising at least
one measuring device configured to detect the workpiece positions
in the machine
9. The machine according to claim 8, wherein the at least one
measuring device comprises a measuring roller that is contacting a
side of the workpieces not to be machined with a contour.
10. The machine according to claim 9, further comprising a machine
control unit, wherein the at least one measuring device comprises a
rotary encoder that detects a rotation of the measuring roller and
sends corresponding detection signals to the machine control
unit.
11. The machine according to claim 10, wherein an adjusting speed
or an adjusting movement of the adjustment of the adjusting unit is
coupled by the machine control unit with the advancing speed of the
workpieces in the machine or the advancing travel of the workpieces
in the machine and thereby with the workpiece positions in the
machine during throughfeed of the workpieces.
12. The machine according to claim 1, wherein the adjusting unit is
a device connectable to the machine.
13. The machine according to claim 1, wherein the machine is a
moulder.
14. A method for machining workpieces of wood, plastic material,
and the like, with a machine according to claim 1, the method
comprising: generating an NC program for a machine control unit of
the machine based on a desired and freely selectable geometry or
contour; executing the NC program during throughfeed of the
workpieces through the machine and repeating the NC program for
each one of the workpieces; detecting a travel or a position of the
workpieces during throughfeed of the workpieces through the
machine; moving at least one contour producing tool transverse to a
throughfeed direction of the workpieces through the machine with at
least one adjusting unit as a function of a desired contour of the
workpieces, of tool data, and of the workpiece positions; wherein
the adjusting unit has such a stiffness and/or low clearance and/or
positioning precision that the finish machined workpieces, when
exiting from the machine, have such a geometry precision and
surface quality that the finish machined workpieces can be used
without further post-machining.
Description
BACKGROUND OF THE INVENTION
[0001] The invention concerns a machine as well as a method for
machining workpieces of wood, plastic material, and the like,
wherein the machine has at least one transport path for the
workpieces on which the workpieces are transported through the
machine, and has tools that are fixedly seated on spindles with
which the workpieces are machined as they pass through the
machine.
[0002] It is known to manufacture end products from workpieces in
several steps on stationary machining centers. Such end products
are used, for example, in the furniture industry, for example, as
arm rests, legs of furniture, cabinet parts, and the like. The
manufacture of such end products is very machine-intensive and
time-intensive. Each workpiece must be clamped on the machining
center so that it can be machined by the corresponding tool. The
machining quality, in particular the surface quality, is generally
low so that post-machining is still required.
[0003] The invention has the object to configure the machine of the
aforementioned kind and the method of the aforementioned kind in
such a way that workpieces can be machined to end products in a
simple way at high efficiency but still with high precision, in
particular with high surface quality.
SUMMARY OF THE INVENTION
[0004] This object is solved for the machine of the aforementioned
kind in accordance with the invention in that at least one of the
spindles is coupled with an adjusting unit having at least one
adjusting axis, wherein the spindle, for producing a contour on the
workpiece, is adjustable by the adjusting unit transverse to the
throughfeed direction of the workpiece during the workpiece
throughfeed as a function of the advancing speed of the workpiece
and/or the workpiece position as the workpiece passes through the
machine, and wherein the adjusting unit has such a stiffness and/or
low clearance and/or positioning precision that the end products
machined from the workpieces, when exiting from the machine, can be
used without further post-machining.
[0005] The object is solved for the method of the aforementioned
kind in accordance with the invention in that, based on a desired
and freely selectable geometry or contour, an NC (numerical
control) program for the machine control unit is generated that
upon throughfeed of the workpieces is executed and repeated for
each workpiece, in that the travel or the position of the
workpieces through the machine is detected, in that at least one
contour producing tool is moved transverse to the transport
direction of the workpieces by means of at least one adjusting unit
as a function of the desired contour, of tool data, and of the
workpiece position, and in that the adjusting unit has such a
stiffness and/or low clearance and/or positioning precision that
the finish machined workpieces, when exiting from the machine, have
such a geometry precision (trueness) and surface quality that they
can be used without further post-machining.
[0006] With the machine according to the invention, it is possible
to machine the workpieces in a throughfeed method with high
precision and in particular with high surface quality so that the
end products can be used immediately for their intended purpose.
Post-machining of the workpiece after exiting from the machine is
not required. The machine comprises at least one spindle which is
coupled with an adjusting unit so that the spindle with the tool
seated thereon, as the workpiece travels through the machine, can
be adjusted transverse to the travel direction of the workpiece in
accordance with the contour to be produced. As an adjusting unit, a
device is employed that is distinguished by a high positioning
precision and/or stiffness and/or low clearance. A surface quality
can be achieved which at least corresponds to the finish quality of
the conventional surface machining of workpieces. Finish quality is
to be understood as such a machining quality that post-machining of
the end products is not required.
[0007] During milling of the workpiece with the rotating tool, a
corrugation pattern is produced on the surface of the workpiece.
The spacing of the corrugations results from the chip removal in
cycloidal sections during circumferential face milling or profile
milling and is referred to as knife mark or planing mark. The
shorter this knife mark, the smoother and finer the workpiece
surface. The length of the knife mark depends on the advancing
speed v.sub.f of the workpiece, on the rotary speed n of the
spindle, and on the number z of the surface-generating knives of
the tool. When all cutting edges work on the same cutting circle,
the knife impacts correspond to the pitch f.sub.z according to
f.sub.z=v.sub.f/(nz). Without special precautionary measures, even
for multi-knife tools only one cutting edge is impressed on the
machined surface due to the tolerances. In this so-called
single-knife finish, z=1 is applied for calculating the knife
impact with the equation for the pitch. Therefore, by adjusting
these three parameters as the workpiece travels through the
machine, an extremely small knife mark can be achieved which leads
to the high surface quality of the end product. A good quality and
a high quality surface result for planing/knife marks between 1 mm
and 2 mm. The uniformity of the knife marks or of the corrugation
pattern is also decisive for a high surface quality. Non-uniform
knife marks can be the result of, for example, tool or workpiece
vibrations, fluctuations of the advancing speed or rotary speed of
the tool, and clearance-exhibiting adjusting movements of the tool
and can lead to the workpieces not being useable or having to be
post-machined. The rotary speed of the spindle and thus of the tool
is adjusted to the advancing speed of the workpiece such that the
desired high surface quality, i.e., uniformity of the knife mark
and identical knife mark length, can be achieved on the end
product.
[0008] Since the adjusting unit is embodied to at least have low
clearance, advantageously however to be free of clearance, the
change of the moving direction of the adjusting unit has no
negative effect on the surface quality and the uniformity of the
planing mark in workpiece machining. The great stiffness of the
adjusting unit also contributes to this.
[0009] For a uniform advancing speed, depending on the contour and
the feed speed of the tool, the relative advancing speed and thus
the pitch of the tool changes. For a uniform pitch, i.e., uniform
knife mark, upon increasing the relative advancing speed the rotary
speed of the tool is to be increased. The travel speed or advancing
speed of the workpiece through the machine and the feed speed of
the tool is thus coupled to the rotary speed of the spindle in such
a way that a very high surface quality results on the end product.
For this reason, the rotary speed of the spindle supporting the
tool is advantageously at all times adjustable during throughfeed
action as a function of the travel speed or advancing speed and the
contour of the workpiece such that the knife mark is kept constant.
The rotary speed adjustment can be performed by a control unit or
feedback control.
[0010] Advantageously, the adjusting unit is designed to be free of
clearance which is especially advantageous for a high surface
quality.
[0011] Advantageously, the adjusting unit is a linear drive. With
it, it is possible to adjust the spindle with high precision and
within a very short time relative to the workpiece such that the
desired contour on the workpiece is produced with the desired high
surface quality. Since the linear drive has no clearance and a high
stiffness, the tool can be very precisely adjusted to the position
that is required for contour milling.
[0012] The adjusting unit can also be embodied by a ball screw
drive. With it, it is also possible to adjust the tool with great
precision, free of clearance, and within a very short time to the
desired working position in relation to the workpiece passing
through. A ball screw drive can also be embodied free of clearance
and with high stiffness so that a great positional precision of the
spindle or of the tool seated thereon results.
[0013] The spindle with the tool is adjusted transverse to the
advancing direction of the workpiece through the machine.
Advantageously, there exists the possibility to provide the
adjusting unit with at least one further adjusting axis. In this
way, be means of the adjusting unit, the spindle or the tool can be
adjusted within the plane that is defined by the two adjusting
axes.
[0014] Advantageously, the adjusting axes of the adjusting unit in
this case are positioned at a right angle to each other. This can
be achieved very simply in that the adjusting unit is embodied in
the form of a compound slide carriage whose two carriage parts
independent of each other can be adjusted at a right angle to each
other.
[0015] In order for the position of the workpiece in the machine to
be precisely known as it passes through, the workpiece position is
detected by at least one measuring device. In this way, the
adjusting speed or adjusting movement as well as the rotary speed
of the spindle can be adjusted optimally to the advancing movement
of the workpiece as it is fed through the machine in order to
obtain the desired contour with high contour trueness and surface
quality.
[0016] In an advantageous embodiment, the measuring device has a
measuring roller which is contacting a side of the workpiece that
is not to be machined. The measuring roller is advantageously
forced under pressure against the workpiece side so that, as the
workpiece passes through, no slip between the workpiece and the
measuring roller occurs. In this way, the workpiece position in the
machine can be determined with high precision.
[0017] The measuring roller is seated advantageously on a shaft
whose rotation is detected by a rotary encoder. The rotary encoder
provides accordingly signals to the machine control unit that, in
accordance with the rotary encoder signals, adjusts the moving
speed or the moving travel of the adjusting unit as well as the
rotary speed of the spindle with respect to high contour trueness
and surface quality. The advancing speed or advancing movement of
the workpiece in the machine is advantageously coupled by means of
the machine control unit with the adjusting speed or adjusting
movement of the adjusting unit, advantageously also with the rotary
speed of the spindle.
[0018] The adjusting unit is preferably a device that can be simply
connected to the machine. In this way, there is the possibility of
retrofitting machines that are already at hand at the customer with
such a device so that these machines are provided with an
additional machining possibility for the workpieces.
[0019] It is preferred that the machine is a moulder. It enables
machining of all four longitudinal sides of the workpiece as the
workpiece passes through. In this context, the moulder can be
adjusted such that, for example, only at one of the longitudinal
sides of the workpiece a contour is produced while the remaining
workpiece sides are not machined. However, it is also possible to
combine contour milling with a straight planing process and/or
profiling of at least one additional longitudinal side of the
workpiece in the moulder. In this way, the workpiece can be
machined at its different longitudinal sides in different ways in a
single pass through the machine.
[0020] With the method according to the invention, the geometries
or contours can be produced on workpieces with high precision and
high surface quality. First, based on a desired and freely
selectable geometry or contour, an NC (numerical control) program
for the machine control unit is generated. Upon throughfeed of the
workpieces through the machine, this NC program is then executed
and repeated for each workpiece. The path or the position of the
workpieces through the machine is detected. In this context, also
the advancing speed can be determined with which the workpiece is
transported through the machine. At least one contour-producing
tool is moved transverse to the transport direction of the
workpiece through the machine by means of at least one adjusting
unit as a function of the desired geometry or contour, of tool data
such as the tool diameter, and of the workpiece position. The
adjusting unit exhibits in this context such a stiffness and/or low
clearance and/or positioning precision that the finish machined
workpieces (end products) when exiting from the machine have such a
geometry precision (trueness) and surface quality that they can be
used without further post-machining. After exiting from the
machine, the finish machined workpieces have, aside from the high
geometry precision, a high surface quality which at least
corresponds to the finish quality of conventional surface machining
of workpieces. Therefore, the end products which are exiting from
the machine can be immediately applied to their intended use. Since
the workpiece position, i.e., the leading end of the workpiece and
the advancing speed or the advance of the workpieces, is detected
in the machine, the high geometry precision and surface quality for
machining the workpiece are ensured in a simple way.
[0021] With the method according to the invention, the workpieces
can be machined such that the uniformity of the planer marks of the
tool on the end products after exiting from the machine is not
visibly impaired. In particular, at the reversing points of the
adjusting unit or at the reversing areas of the contour, taking
into account the high stiffness and/or minimal clearance, a high
surface quality of the end products can be achieved. The high
positioning precision of the adjusting unit moreover leads to a
geometry precision of the contour and thus of the end product.
[0022] The subject matter of the invention results not only from
the subject matter of the individual claims but also from the
specifications and features disclosed in the drawings and in the
description. Even if they are not subject matter of the claims,
they are claimed as being important to the invention inasmuch as
they are novel, individually or in combination, relative to the
prior art.
[0023] Further features of the invention result from the further
claims, the description, and the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The invention will be explained in more detail with the aid
of two embodiments illustrated in the drawings.
[0025] FIG. 1 shows in front view a machine of the invention in the
form of a moulder.
[0026] FIG. 2 shows in enlarged illustration a part of the spindle
arrangement of the machine according to FIG. 1.
[0027] FIG. 3 shows the detail III of FIG. 1 in an enlarged
illustration.
[0028] FIG. 4 shows in an illustration corresponding to FIG. 2 a
second embodiment of a machine according to the invention.
[0029] FIG. 5 shows a workpiece that has been produced on the
machine according to FIG. 1 or FIG. 4.
[0030] FIG. 6 is a schematic of the machine control unit
interaction with devices of the machine.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0031] With the moulder described in the following, workpieces of
wood, plastic material, and the like are machined by contour
milling. End products provided with the desired contour can be
produced from the workpieces. Such contour-milled workpieces can be
used, for example, in furniture production, for example, as a leg
for a chair or table, as arm rests, and the like. The contours of
the milled workpieces can have any desired shape and can be freely
defined. The contour of the workpieces is produced as the workpiece
passes through the machine. The machine has a CNC (computerized
numerical control) control unit as well as CNC (computerized
numerical control) controlled tool axes.
[0032] The moulder is a milling machine with which the workpieces 1
can be machined in a throughfeed process on all four longitudinal
sides. Depending on the desired shape of the end product, the
workpieces 1 can be machined only on one side but also on several
or also on all sides. The workpieces 1 are elongate workpieces
which in general have a quadrangular cross section.
[0033] For transport of the workpieces 1 through the machine,
advancing and transporting rollers 2 are provided which are resting
on the workpieces.
[0034] In the infeed area of the moulder, there is a straightening
table 3 on which the workpieces 1 are supplied to the machine. On
the right side of the straightening table 3 in the infeed
direction, an edge jointing fence 4 is provided on which the
workpiece 1 with its right longitudinal side in transport direction
is resting during transport through the machine. The edge jointing
fence 4 is adjustable transverse to the transport direction of the
workpiece 1 in order to adjust the size of the chip removal on the
right longitudinal side of the workpiece 1. The straightening table
3 can be adjusted in vertical direction so that the size of the
chip removal at the bottom side of the workpiece 1 can be
adjusted.
[0035] By means of an infeed opening 5, the workpiece 1 enters a
machine chamber of the machine. In the machine chamber, a
horizontal bottom planing spindle is provided on which a
schematically illustrated planing tool 6 is fixedly seated. It
machines by chip removal the bottom side of the workpiece 1 passing
through the machine, preferably by planing. In transport direction
of the workpiece 1 downstream of the planing tool 6, a vertical
right spindle is provided on which a tool 7 is seated. It can
machine the right longitudinal side of the workpiece 1 in transport
direction. In the embodiment, the right longitudinal side is planed
straight with the tool 7. In this case, the tool 7 is a planer head
with straight knives. The tool 7 can however also be a profiling
tool with which on the right workpiece side a profile is produced.
In transport direction of the workpiece 1 downstream of the
vertical right spindle, a vertical left spindle is provided on
which a tool 8 is seated. It machines the left longitudinal side of
the workpiece 1 in transport direction.
[0036] When passing through the machine, the workpieces 1 are
resting on a machine table 9 which forms a transport path on which
the workpieces 1 are transported through the machine by resting
thereon. The machine table 9 is fixed on the machine and forms a
horizontal support plane and reference plane for the workpieces
1.
[0037] In transport direction of the workpieces 1 downstream of the
right tool 7, the workpiece 1 is further guided on a fence (not
illustrated) through the machine. The workpiece 1 is contacting
with its right machined longitudinal side this fence which is fixed
on the machine and which forms the vertical contact plane and
reference plane.
[0038] In transport direction downstream of the left vertical
spindle, the machine is provided with a horizontal top spindle on
which the tool 10 is seated. The top side of the workpiece 1 is
machined by it as the workpiece 1 passes through the machine.
[0039] In the embodiment according to FIG. 1, a second top tool 11
is provided at a spacing downstream of the top tool 10 and is
driven in rotation about a horizontal axis.
[0040] At a spacing downstream of the horizontal top tool 11 a
horizontal bottom spindle is provided on which a tool 12 is fixedly
seated with which the bottom side of the workpiece 1 can be
machined.
[0041] The workpiece 1 after its machining exits through outlet
opening 13 from the machine.
[0042] During machining of the workpieces 1, the machine chamber is
closed by a machine cover 14.
[0043] In the illustrated exemplary moulder, in the area between
the two top tools 10, 11 a horizontal bottom table roller 15 is
provided. A further horizontal bottom table roller 16 is provided
at the level of the outlet opening 13. The machine table 9 is
interrupted for the two parallel oriented horizontal rollers 15, 16
as well as the bottom tools 6, 12 so that machining of the
workpiece bottom side by means of the tools is possible.
[0044] Based on the illustrated embodiment, in the following it
will be described how a contour is milled on the longitudinal side
of the workpiece 1 to the left in transport direction. For this
purpose, it is required that the position of the workpiece 1 in the
machine can be detected at all times. For this purpose, in the
transport direction of the workpiece 1 upstream of the left tool 8
a first measuring roller 17 is provided (FIG. 3) which is freely
rotatably supported about vertical axis 18. The measuring roller 17
is located at the lower end of the vertical measuring roller
support 19 which is received in a holder 20. The holder 20 is
located at the free end of a support arm 21 which is supported so
as to be slidable in its longitudinal direction in a holder tube
22. The latter is arranged in a suitable way fixedly on the
machine. The support arm 21 is axially loaded by an axial force so
that the measuring roller 17 is forced against the longitudinal
side 23 of the workpiece 1 to the left in the transport direction.
The support arm 21 can be subjected to a spring force or to
pneumatic/hydraulic pressure. In this way, it is ensured that the
measuring roller 17 is pressed reliably against the longitudinal
side 23 of the workpiece 1. Upon movement of the workpiece 1, the
measuring roller 17 is reliably rotated by the workpiece so that
the position of the workpiece 1 is reliably detected.
[0045] A rotary encoder 24 is fixedly connected to the measuring
roller 17 and is provided at the upper end of the measuring roller
support 19 and supplies rotary encoder signals to the machine
control unit by means of a data line 25.
[0046] Since with the left vertical tool 8 the contour is generated
on the left longitudinal side 23 of the workpiece 1 and since the
measuring roller 17 in transport direction is upstream of the tool
8, the position of the workpiece 1 can be properly detected.
[0047] In order to detect the leading end of the workpiece 1 and
thus its exact position in the machine, a light barrier 26 is
provided in transport direction upstream of the left vertical tool
8. It is located in the area between the tool 8 and the measuring
roller 17. When the light barrier 26 is interrupted by the leading
end of the workpiece 1, the sensor of the light barrier 26 sends a
signal to the machine control unit. This represents the starting
point of the positional measurement by means of the measuring
roller 17.
[0048] The sensor for detecting the leading end of the workpiece is
not limited to a light barrier 26 but can be any type of sensing
means capable of detecting the leading end of the workpiece, in
particular of a workpiece of wood, with the required precision and
speed upon its transport through the machine.
[0049] The first measuring roller 17 and the light barrier 26 can
also be arranged in transport direction of the workpiece 1 upstream
of the right tool 7 or even upstream of the top tool 10 or 11,
depending on which tool or tools are to be used for machining a
contour on the workpiece. Then also, as soon as the leading end of
the workpiece has interrupted the light barrier 26, a start signal
is generated for the position measurement by means of the measuring
roller 17.
[0050] FIGS. 1 and 2 show the possibility that a further measuring
roller 17 is not contacting the longitudinal side 23 of the
workpiece 1 that is to be contoured but is contacting its top side
27. Since in the embodiment the workpiece top side 27 is not to be
provided with a contour, the position of the workpiece 1 in the
machine can be precisely detected also by means of the measuring
roller 17. The measuring roller 17 in this case is freely rotatable
about a horizontal axis. It is forced by means of the force-loaded
support arm 21 in the described way strongly against the workpiece
top side 27. The configuration of the measuring arrangement
corresponds to the described embodiment with the measuring roller
17 rotatable about the vertical axis 18.
[0051] For travel detection by means of measuring rollers, a
measuring roller 17 must always contact the workpiece 1. First,
this is done upstream of the tool 8 because a measuring roller
downstream of the tool 8 can not yet detect the workpiece 1 and
therefore no travel measurement is possible. Once the workpiece 1
has left the measuring roller 17 upstream of the tool 8, this
measuring roller can no longer provide signals and the travel
detection must be realized by means of the measuring roller 17
downstream of the tool 8.
[0052] By a sensor 38 on the measuring roller 17 it is detected
when the measuring roller 17 is contacting the workpiece 1 because,
when the measuring roller 17 contacts the workpiece 1, the support
arm 21 in the holding tube 22 is axially adjusted and thereby the
sensor 38 is actuated.
[0053] For travel detection, a measuring roller 17 which is
contacting the workpiece 1 is thus always utilized, wherein by
means of the control unit it is determined when which one of
measuring rollers 17 is to be used for the travel detection.
Therefore, essentially a cascading utilization of the measuring
rollers 17 occurs wherein however the travel measurement of the
downstream measuring roller 17 is based on that of the preceding
one, respectively.
[0054] In the embodiment according to FIG. 1, the further measuring
roller 17 in transport direction of the workpiece 1 is arranged
downstream of the top tool 10. The arrangement of the measuring
roller 17 depends on the machining tasks and on which tools are to
be used for this purpose. In this context, it is necessary to
flexibly bring into action and evaluate the measuring rollers 17
depending on the machining task.
[0055] In the illustrated example, the two measuring rollers 17
upstream and downstream of the tool 8 are used.
[0056] The travel detection of the workpieces 1 can of course be
performed also by other known measures. For example, the travel
detection of the workpiece 1 can be realized directly by means of
the advancing drive of the machine. In this context, the rotary
speed of the drive, of the drive shaft, or of the transport rollers
is detected, based on the effective diameter of the transport
rollers, is converted to the travel of the workpiece 1 through the
machine.
[0057] Moreover, a travel detection is also possible by optical
sensors which operate contactless and are used instead of the
measuring rollers 17 and can be arranged in the same way as the
latter in the machine.
[0058] The path of the workpieces 1 through the machine can also be
detected by cameras in the machine chamber. The camera sends
corresponding signals to the machine control unit which evaluates
the camera signals and utilizes them for position detection of the
workpieces.
[0059] The travel detection can also be realized by means of a
distance measurement by means of laser on the end face of the
workpiece 1.
[0060] Furthermore, for example, the use of a linear scale on
magnetic basis parallel to the advancing direction is possible for
the travel detection. In this case, in the workpiece 1 to be
machined magnets are provided. Also, the use of transponders in the
workpieces is possible. Also, a linear scale as an incremental
scale with correlated transducer in the workpiece or the like can
be employed.
[0061] A further possibility of travel detection resides in that
the workpieces 1 are transported by means of chains. The use of
chains has the advantage that no or hardly any slip between the
workpiece 1 and the chain occurs. In this way, the chain travel or
the chain speed is used for determining the position of the
workpiece 1 in the machine.
[0062] Finally, it is also possible to transport the workpieces,
for example, by means of chains, bands, belts, or linear units that
have projecting fingers with which the workpieces are held with
form fit or pushed with form fit through the machine. In this case,
the travel of the fingers can be detected and can be utilized for
positional determination of the workpiece 1 in the machine.
[0063] In the illustrated example, the workpiece 1 at its
longitudinal side 23 is provided with a contour 28, as it is
illustrated in FIG. 4. This contour 28 is produced by the tool 8
that is arranged on the vertical left spindle of the moulder. The
top side 27, the bottom side 29, and the two end faces 30, 31 of
the workpiece 1 remain free of contours. During throughfeed of the
workpiece 1 through the machine, the workpiece is contacting with
its longitudinal side 32 to the right in the transport direction
the edge jointing fence 4, or the fence which is not
illustrated.
[0064] The spindle supporting the tool 8 is adjustable in Y
direction (FIG. 2) and thus perpendicular to the X direction. The X
direction is the throughfeed direction (transport direction) of the
workpiece 1 through the machine.
[0065] The spindle of the right tool 8 is connected with an
adjusting unit 33 which is only schematically illustrated. The
adjusting unit 33 is designed such that it can quickly and
position-precisely adjust the tool 8 in Y direction into the
position required for contour milling. Preferably, the adjusting
unit 33 is embodied as a linear motor which is suitable
particularly to move the tool 8 quickly and with high positioning
precision into the desired position. The clearance-free design and
high stiffness that distinguishes the linear motor contributes to
this. It is therefore possible to adjust the tool 8 exactly into
the position required for contour milling of the workpiece 1.
[0066] As an adjusting unit 33, also a ball screw drive is
conceivable. The latter can also adjust the tool 8 with high
precision and quickly into the desired position in Y direction.
[0067] In principle, all drive systems are conceivable that are at
least low clearance, advantageously are free of clearance, and have
such a stiffness that in particular for movement reversal of the
adjusting unit the required precision and surface quality can be
achieved. In this context, in particular also the dynamics and the
masses to be moved of adjusting unit, spindle receptacle, spindle,
and tool are to be taken into account. For the geometry precision
or geometry trueness, the positioning precision of the adjusting
unit 33 is decisive in essence. For the uniformity of the planer
mark of the tool, the stiffness and the clearance of the adjusting
unit are decisive. The stiffness influences in particular the
hysteresis at the reversing points of the adjusting unit. The
stiffness as well as low clearance or clearance-free design of the
adjusting unit 33 are so good that the uniformity of the planing
marks on the end product is not visibly impaired in particular at
the reversing points or reversing areas of the adjusting unit 33.
When it is assumed that the depth of the planer marks is within a
single-digit micrometer range and a knife impact depth on the end
product becomes noticeable from approximately 10 .mu.m on, the
hysteresis and the clearance of the adjusting unit 33 amount also
to only a few micrometers.
[0068] The respective drive is linked by means of the machine
control unit in such a way to the transport speed of the workpiece
1 through the machine that the adjustment of the adjusting unit 33
in Y direction is coupled to the advancing speed of the workpiece 1
through the machine or its advancing travel. Through the data line
25, the measuring rollers 17 provide the corresponding travel
signals to the control unit of the machine where the signals are
processed/evaluated.
[0069] The adjusting unit 33 can be used as an auxiliary attachment
device with which it is possible to retrofit moulders with an
adjusting unit so that contour milling of the workpieces is also
possible with the moulders.
[0070] Since by means of the tool 8 the contour 28 is provided on
the longitudinal side 23 of the workpiece 1 to the left in the
throughfeed direction through the machine, the adjusting unit 33 is
provided on the moulder such that the tool 8 can be adjusted in Y
direction relative to the workpiece 1.
[0071] Depending on which side of the workpiece 1 is to be provided
with the contour, the adjusting unit 33 can be arranged on the
moulder such that the contour can be provided not only on the left
longitudinal side 23 but also on the right longitudinal side 32 of
the workpiece 1. It is even possible to provide at the same time
both longitudinal sides 23, 32 of the workpiece 1 with a contour by
means of the tools 7 and 8. In this case, the spindles of the two
tools 7, 8 are coupled with one adjusting unit 33 each,
respectively.
[0072] The contours on the workpiece can be provided not only at
one or at both longitudinal sides 23, 32 of the workpiece 1 but
also, for example, on its top side 27 and/or its bottom side 29. In
this case, for example, the horizontal top tool 10 and the
downstream horizontal bottom tool 15 are adjusted in Z direction by
means of the adjusting unit 33. In this case, the Z adjustment is
also coupled to the advance of the workpiece 1 in X direction so
that the contour at the top side and/or bottom side of the
workpiece 1 can be manufactured with the required high
precision.
[0073] In this alternative embodiment, the measuring rollers 17 are
always contacting the workpiece side that is not to be provided
with a contour.
[0074] The adjusting unit 33 can also be designed such that it not
only can adjust the corresponding tool in a linear direction but
also within a plane. Thus, it is possible in the illustrated
embodiment to design the adjusting unit 33 such that the tool 8 is
adjustable in the X-Y plane. This can be achieved, for example, by
designing the adjusting unit 33 in the form of a compound slide
carriage whose two carriage parts independent of each other can be
adjusted in X direction and in Y direction. With the two carriage
parts, it is then possible to adjust the tool 8 within the X-Y
plane in any desired direction.
[0075] Accordingly, the desired contours can be milled also on the
end faces 30, 31 of the workpiece 1 with the tool 8. The adjusting
speed can be synchronized in X direction with the advance wherein
then, upon adjusting the tool 8 in Y direction, an end face
machining at a right angle to the longitudinal side 23 is carried
out. Other angle positions and end face contours are possible by a
corresponding control of the X movement and Y movement of the tool
8 by means of the adjusting unit 33.
[0076] FIG. 4 shows a machine in which instead of the horizontal
tool 10 a device 34 is provided. It has a vertical tool 35 with
which bores 36 (FIG. 5) or slotted holes 37 can be produced in the
workpiece 1. The device 34 is moved along during production of the
bores 36 or the slotted holes 37 in X direction with the workpiece
1 at the same advancing speed. In other respects, the machine is of
the same configuration as the preceding embodiment.
[0077] When producing the bore 36, the device 34 moves relative to
the workpiece 1 in Z direction. When the slotted hole 37 is
produced, the device 34 moves in addition also in X direction or Y
direction relative to the workpiece 1. Since the slotted hole 37 in
the embodiment is positioned at a slant to the X direction, the
device 34, after feeding in Z direction, is moved within the X-Y
plane.
[0078] The tool 35 of the device 34 can be a drill or an end mill
tool. The device 34, for example, is a milling device that is
acting from above on the workpiece 1. The device 34 can also be
arranged in transport direction (X direction) on the left or right
side. Then, the bores 36 and/or the slotted holes 37 not only can
be provided at the top side 27 but also in the left and/or right
longitudinal side of the workpiece 1.
[0079] As shown in FIG. 4, it is advantageously provided that the
device 34 is also movable about the X axis and/or about the Y axis.
Therefore, the slotted holes 37 as well as the bores 36 can be
introduced at different angles into the workpiece 1.
[0080] It is furthermore possible to provide and arrange the
adjusting unit 33 such that the corresponding tool is adjustable by
it in an X-Z plane or in a Y-Z plane.
[0081] It is finally possible to designed the adjusting unit 33
such that the corresponding tool within the X-Y-Z space can be
adjusted at will. In this case, the adjusting unit 33 also has an
adjusting component in the Z direction.
[0082] The spindle for the tool 8 for milling the contour can also
be pivotable about an axis B which is positioned in the X direction
(FIG. 2). This corresponds to the function of a universal spindle
of a conventional moulder. It is then possible to mill on the
workpieces 1 contours that are not rectangular but are positioned
at a slant to the top or bottom sides 27, 29 of the workpiece 1. In
particular, in such a case a slant of the tool 8 can be changed as
the workpiece 1 passes through the machine so that the angular
position of the contour changes across the length of the
workpiece.
[0083] Due to the adjustment of the tool 8 in radial direction (Y
direction) and axial direction (Z direction) and pivoting about the
X axis in combination with the advancing movement of the workpiece
1 (X direction), a four-axis machining in throughfeed is possible
in a moulder for the first time.
[0084] In these variants, the adjusting unit 33 is also always
embodied such that the corresponding tool can be adjusted quickly
and with precise positioning in the required position relative to
the workpiece 1.
[0085] In the described variants, it is also possible to provide
more than one adjusting unit 33 so that the workpiece 1 can be
processed at several sides.
[0086] With the respective adjusting unit 33, the corresponding
tool can be adjusted into any position upon throughfeed of the
workpiece 1. In this way, freely programmable contours can be
provided on the workpiece. These contours can be provided on all
sides of the workpiece 1. For this purpose, the corresponding tools
are adjustable with an adjusting unit 33, respectively. Since the
workpieces 1 are machined by a throughfeed process and the
adjusting unit 33 enables a quick but still position-precise
adjustment of the tool, very high productivity rates are realized.
For contour milling of the workpieces 1 only one machine is
required with which the workpieces 1 can be machined in different
ways.
[0087] For example, the top and bottom sides 27, 29 and the
longitudinal side 32 can be planed straight and the longitudinal
side 23 can be provided with the contour 28. Furthermore it is
possible to provide, for example, the longitudinal side 23 with the
contour 28 and to introduce on at least one other side a profile
into the workpiece 1. Accordingly, profiling tools are provided on
the corresponding spindles. The contour as well as the profiles are
then produced on the workpiece 1 in one pass through the machine.
Therefore, a plurality of working processes are combined in a
machine which enables very short throughfeed times. The space
requirement is also minimal because it is not necessary to provide
different processing machines for the different types of workpiece
machining. Storage for intermediately storing workpieces between
the individual machining steps is eliminated. Also, transport
damages which can result from intermediate storage and removal and
feeding of the workpieces to different processing machines are
avoided.
[0088] With the adjustable tools with which the contour on the
workpiece 1 is generated, high surface qualities can be achieved.
With the machine, a surface in furniture quality, i.e., with
so-called finish quality, is produced on the workpiece. In this
way, post-machining of the contoured end products is not required.
The machined end products which are leaving the machine can
therefore be immediately applied to their intended use. With the
adjusting units 33, the tools can be highly precisely adjusted in
the described way so that on the finish machined workpiece a high
geometry precision with high surface quality is ensured.
[0089] The workpieces can be positioned end-to-end, i.e.,
contacting each other in longitudinal direction, or can be conveyed
individually through the machine and machined. In end-to-end
machining, a sensor is advantageously employed which detects the
respective leading end of the workpiece.
[0090] Not only workpieces 1 of wood but also workpieces of other
materials can be machined. For example, the workpieces can be
comprised of plastic material, aluminum, and the like.
[0091] With the machine it is possible for the first time to
provide workpieces 1 with any contour in a throughfeed-operated
profiling machine with the adjusting unit 33. In particular the use
of a linear motor as an adjusting unit 33 makes it possible to mill
with high precision the desired contours on the workpiece 1. The
machine enables the user to produce such contoured workpieces with
high surface quality in finish quality and high precision. Also,
the machine enables a high efficiency. With the machine it is
possible for the customer to optionally only plane straight the
workpieces 1 on all four sides, wherein an adjustment of at least
one of the tools during throughfeed is not performed. Furthermore,
at least on one side of the workpiece 1, a contour can be milled
while at least on one additional side only planing straight and/or
profiling is performed.
[0092] For producing a contour on a workpiece, an NC program is
first generated, based on a workpiece drawing with the desired
contouring. The geometry of this contour can be freely programmed.
The NC program generation or the NC code generation is
advantageously performed in an automated process. The NC program is
then transferred to the machine control unit of the machine and is
executed when machining the workpieces 1, advantageously in a
process that is repeated for each workpiece. The machine is a
throughfeed machine in the form of a moulder which is provided with
the auxiliary device in the form of the adjusting unit 33. The
latter is provided for those spindles with which the contours 28 on
the workpiece 1 are to be generated. The machine has also a
detection system in order to detect the position of the workpieces
1 as the workpieces pass through the machine. Depending on the
contour 28 to be produced, the machine has special guiding and
holding elements in order to convey the workpieces 1 exactly,
vibration-free, and free of clearance through the machine.
[0093] The specification incorporates by reference the entire
disclosure of German priority document 10 2016 013 408.9 having a
filing date of 4 Nov. 2016.
[0094] While specific embodiments of the invention have been shown
and described in detail to illustrate the inventive principles, it
will be understood that the invention may be embodied otherwise
without departing from such principles.
* * * * *