U.S. patent application number 17/033709 was filed with the patent office on 2021-04-01 for honing machine.
This patent application is currently assigned to KADIA Produktion GmbH + Co.. The applicant listed for this patent is KADIA Produktion GmbH + Co.. Invention is credited to Henning Klein, Uwe Moos, Roland Regler.
Application Number | 20210094140 17/033709 |
Document ID | / |
Family ID | 1000005130759 |
Filed Date | 2021-04-01 |
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United States Patent
Application |
20210094140 |
Kind Code |
A1 |
Klein; Henning ; et
al. |
April 1, 2021 |
HONING MACHINE
Abstract
A honing machine (100) for honing a bore in a workpiece
comprises a support structure (120) fixed to the machine, and at
least one honing unit (130) which is mounted on the support
structure. The honing unit has a main support (160) which can be
mounted fixedly with respect to the support structure and a spindle
unit (150) which is supported by the main support and in which a
spindle shaft is rotatably mounted, wherein the spindle shaft is
rotatable about a spindle axis by means of a rotary drive and, at a
tool-side end (153), has a device for the fastening of a honing
tool. Furthermore, a linear guide system which is arranged between
the main support (160) and the spindle unit (150) for guiding a
linear stroke movement of the spindle unit (150) relative to the
main support (160) and a stroke drive for generating the stroke
movement of the spindle unit (150) are provided. The main support
(160) is attached to the support structure (120) in such a manner
that a workpiece-close end (166) of the main support lies at a
distance above a spindle-facing limit of a workpiece height range.
The spindle unit (150) is attached with respect to the linear guide
system in such a manner that, in a workpiece-close end position of
a stroke movement, the tool-side end (153) of the spindle shaft
lies closer to the workpiece height range than the workpiece-near
end (166) of the main support (160).
Inventors: |
Klein; Henning; (Stuttgart,
DE) ; Moos; Uwe; (Dettingen an de Erms, DE) ;
Regler; Roland; (Georgensgmund, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KADIA Produktion GmbH + Co. |
Nurtingen |
|
DE |
|
|
Assignee: |
KADIA Produktion GmbH + Co.
Nurtingen
DE
|
Family ID: |
1000005130759 |
Appl. No.: |
17/033709 |
Filed: |
September 26, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B24B 33/105 20130101;
B24B 33/08 20130101; B24B 33/02 20130101 |
International
Class: |
B24B 33/02 20060101
B24B033/02; B24B 33/08 20060101 B24B033/08; B24B 33/10 20060101
B24B033/10 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 27, 2019 |
DE |
102019214869.7 |
Claims
1. Honing machine for honing a bore in a workpiece, comprising: a
support structure fixed to the machine; at least one honing unit
mounted on the support structure and which comprises: a main
support which can be mounted fixedly in relation to the support
structure, a spindle unit which is supported by the main support
and in which a spindle shaft is rotatably mounted, wherein the
spindle shaft is rotatable about a spindle axis by means of a
rotary drive and, at a tool-side end, comprises a device for the
fastening of a honing tool, a linear guide system arranged between
the main support and the spindle unit and which serves for guiding
a linear stroke movement of the spindle unit relative to the main
support; a stroke drive for generating the stroke movement of the
spindle unit; wherein an axial installation position of the main
support on the support structure, a usable length of the linear
guide system and the stroke drive define a stroke length and a
stroke position of the honing machine, wherein the stroke position
represents the entirety of all of the axial positions, which can be
reached by means of the stroke drive along the linear guide system,
of the tool-side end of the spindle shaft, and the stroke length
represents an axial distance between a possible workpiece-remote
and a possible workpiece-close axial end position of a stroke
movement of the tool-side end of the spindle shaft, wherein the
main support is attached to the support structure in such a manner
that a workpiece-close end of the main support lies at a distance
above a spindle-facing limit of a workpiece height range; and the
spindle unit is attached with respect to the linear guide system in
such a manner that, in a workpiece-close end position of a stroke
movement, the tool-side end of the spindle shaft lies closer to the
workpiece height range than the workpiece-close end of the main
support.
2. Honing machine according to claim 1, wherein the spindle unit is
mounted on a carriage which runs on guide rails of the linear guide
system, wherein the tool-side end of the spindle shaft projects
over a workpiece-side end of the carriage to the workpiece
side.
3. Honing machine according to claim 1, wherein the honing machine
is designed for use of honing tools of differing length of a honing
tool group in such a manner that, when a longest honing tool of the
honing tool group is used, a workpiece-close end of the honing tool
is retracted at least as far as the workpiece-close end of the main
support when the spindle unit is in a workpiece-remote end position
of the stroke movement.
4. Honing machine according to claim 1, wherein at least one of the
following conditions is met: (i) a structurally possible projecting
length of the tool-side end of the spindle shaft over the
workpiece-close end of the main support lies in the range from 20%
to 40% of the stroke length; (ii) the upper limit of the workpiece
height range is 50% to 75% of the stroke length; (iii) the stroke
length lies in the range from 70% to 90% of the length of the
spindle unit.
5. Honing machine according to claim 1, wherein the rotary drive is
integrated in the spindle unit by being arranged within a spindle
housing accommodating the spindle shaft.
6. Honing machine according to claim 1, wherein the stroke drive
comprises an electric linear motor with a primary part and a
secondary part which are movable relative to one another parallel
to the longitudinal direction of the longitudinal guide system.
7. Honing machine according to claim 6, wherein the primary part is
attached on the spindle unit side and a row of permanent magnets is
arranged within the main support.
8. Honing machine according to claim 1, further comprising an
expansion drive for expanding the honing tool, wherein the
expansion drive is coupled to an advancing rod running in the
interior of the spindle shaft, wherein the expansion drive is
designed as an electric direct drive.
9. Honing machine according to claim 8, wherein the electric direct
drive is a torque motor or a moving coil drive.
10. Honing machine according to claim 1, further comprising a
workpiece transport system comprising a plurality of workpiece
receptacles which are selectively movable into a machining position
in which a bore which is to be machined is arranged coaxially with
respect to the spindle axis.
11. Honing machine according to claim 10, wherein the workpiece
transport system comprises a rotary table rotatable about an axis
of rotation and comprising a table panel which, on a pitch circle
about the axis of rotation, comprises a plurality of workpiece
receptacles for holding a respective workpiece, which workpiece
receptacles are selectively movable by means of the rotary table
into a machining position in which a bore which is to be machined
is arranged coaxially with respect to the spindle axis.
12. Honing machine according to claim 1, wherein the spindle unit
comprises a spindle unit housing comprising a first housing portion
for accommodating the rotary drive and a second housing portion for
accommodating the expansion drive, wherein the rotary drive is
accommodated in an exchangeable first cartridge and the expansion
drive is accommodated in a second cartridge which is exchangeable
independently of the first cartridge, wherein the first cartridge
is configured to be introduced into the first housing portion and
the second cartridge is configured to be introduced into the second
housing portion.
13. Honing machine according to claim 1, further comprising an
alignment system for setting the alignment of the spindle axis with
respect to the support structure,
14. Honing machine according to claim 13, wherein the alignment
system is designed for continuously variably and reversibly setting
the alignment of the spindle axis with respect to the support
structure, wherein the alignment system is designed for
independently setting the position of the spindle axis along two
mutually perpendicular translation axes and for setting the
orientation of the spindle axis with respect to two mutually
perpendicular axes of rotation.
15. Honing machine according to claim 13, wherein the alignment
system comprises a first setting unit and a second setting unit
separate from the first setting unit and which is arranged with a
spacing to the first setting unit, wherein each of the setting
units comprises first setting elements for the continuously
variable adjustment of a spacing between the support structure and
the main support in a first direction and second setting elements
for the generation of a continuously variable relative movement of
the main support relative to the support structure in a second
direction which is perpendicular to the first direction.
16. Honing machine for honing a bore in a workpiece, comprising: a
support structure fixed to the machine; at least one honing unit
mounted on the support structure and which comprises: a main
support which can be mounted fixedly in relation to the support
structure, a spindle unit which is supported by the main support
and in which a spindle shaft is rotatably mounted, wherein the
spindle shaft is rotatable about a spindle axis by means of a
rotary drive and, at a tool-side end, comprises a device for the
fastening of a honing tool, a linear guide system arranged between
the main support and the spindle unit and which serves for guiding
a linear stroke movement of the spindle unit relative to the main
support; a stroke drive for generating the stroke movement of the
spindle unit; wherein an axial installation position of the main
support on the support structure, a usable length of the linear
guide system and the stroke drive define a stroke length and a
stroke position of the honing machine, wherein the stroke position
represents the entirety of all of the axial positions, which can be
reached by means of the stroke drive along the linear guide system,
of the tool-side end of the spindle shaft, and the stroke length
represents an axial distance between a possible workpiece-remote
and a possible workpiece-close axial end position of a stroke
movement of the tool-side end of the spindle shaft, wherein the
main support is attached to the support structure in such a manner
that a workpiece-close end of the main support lies at a distance
above a spindle-facing limit of a workpiece height range; and the
spindle unit is attached with respect to the linear guide system in
such a manner that, in a workpiece-close end position of a stroke
movement, the tool-side end of the spindle shaft lies closer to the
workpiece height range than the workpiece-close end of the main
support, the honing machine being configured for use of honing
tools of differing length of a honing tool group in such a manner
that, when a longest honing tool of the honing tool group is used,
a workpiece-close end of the honing tool is retracted at least as
far as the workpiece-close end of the main support when the spindle
unit is in a workpiece-remote end position of the stroke movement,
and an axial length of the spindle unit is such that, even in the
stroke position most remote from the workpiece, an upper end of the
spindle unit does not project beyond the upper end of the main
support.
17. Honing machine according to claim 16, further comprising a
closed machine cladding surrounding the honing machine, the machine
cladding being closed upwards by a machine roof, wherein the
machine roof is attached directly above the upper end of the main
support.
18. Honing machine according to claim 16, wherein at least one of
the following conditions is met: (i) the stroke length lies in the
range from 70% to 90% of the length of the spindle unit and/or in
the range from 450 mm to 700 mm; (ii) an axial length of the
spindle unit is in the range from 500 mm to 900 mm; (iii) a
structurally possible projecting length of the tool-side end of the
spindle shaft over the workpiece-close end of the main support lies
in the range from 20% to 40% of the stroke length and/or at 10% or
more of the axial length of the spindle unit.
19. Honing machine according to claim 16, comprising only a single
linear guide system, wherein a usable length of the linear guide
system and the stroke drive are configured in such a manner that
different stroke positions within a stroke position range between a
workpiece-close stroke position limit and a workpiece-remote second
stroke position limit of a spindle nose and also different stroke
lengths of an oscillating stroke movement are possible in such a
way that the stroke drive and the linear guide system serve both
for setting the stroke position and for generating the oscillation
movement with a predeterminable oscillation length.
Description
FIELD OF APPLICATION AND PRIOR ART
[0001] This application claims priority to German Patent
Application DE 10 2019 214 869.7 filed Sep. 27, 2019, the entirety
of which is incorporated herein by reference.
[0002] The invention relates to a honing machine for honing a bore
in a workpiece.
[0003] Honing is a cutting machining method using geometrically
undefined cutting edges, in the case of which a honing tool
performs a cutting movement composed of two components and there is
constant areal contact between one or more cutting material bodies,
for example honing strips, of the honing tool and the bore inner
surface to be machined. The kinematics of a honing tool are
characterized by a superposition of a rotational movement and a
stroke movement running in an axial direction of the bore.
Normally, an optional expansion movement is also provided, which
leads to a variation of the effective diameter of the honing
tool.
[0004] A one-off stroke movement of the honing tool within the
bore, composed of an advancement into the bore and a subsequent
retraction out of the bore, is referred to as "bobbing". A repeated
stroke movement within the bore, that is to say an advancement into
the bore, followed by a cyclic reciprocating movement within the
bore, and a subsequent retraction out of the bore at the end, is
referred to as "oscillating".
[0005] In the case of oscillating honing processes, an expansion
movement is generally required, because the effective diameter of
the honing tool is actively varied during the oscillation.
Additionally, the wear of the cutting material bodies is generally
compensated by means of the expansion movement.
[0006] The kinematics of the honing tool generate a surface
structure with criss-crossing machining marks on the bore inner
surface. Surfaces finish-machined by honing can satisfy extremely
high demands with regard to dimensional and shape tolerances, and
in some cases have a special surface roughness and structure, such
as for example a plateau surface, which combines low wear owing to
a high material contact area with the capability of being able to
readily receive an oil film for lubrication. Therefore, many highly
loaded sliding surfaces in engines or engine components, for
example cylinder running surfaces in engine blocks or bore inner
surfaces in housings of injection pumps, are machined by
honing.
[0007] A honing machine is a machine tool suitable for the honing
of bores in workpieces. Said honing machine has at least one honing
unit which is mounted on a support structure fixed to the machine,
for example a stand, a column or a frame. A honing unit comprises a
spindle unit in which a spindle shaft is rotatably mounted. The
spindle shaft is rotatable about its spindle axis by means of a
rotary drive and, at a tool-side end, has a device for the
fastening of a honing tool. A linear guide system is arranged
between the main support and the spindle unit, which linear guide
system serves for guiding a linear stroke movement of the spindle
unit relative to the main support. To generate the stroke movement
of the spindle unit parallel to the spindle axis, a stroke drive is
provided. In general, an expansion drive for expanding the honing
tool is furthermore provided. The expansion drive may for example
be coupled to an advancing rod which runs in the interior of the
spindle shaft.
[0008] The areal contact of the cutting material bodies with the
bore inner surface generates a coaxial machining action, such that
the axis of the bore and the axis of the honing tool align with one
another. In general, the workpiece and/or the honing tool are
provided with movement degrees of freedom such that the bore and
the honing tool can align with one another.
[0009] A honing machine is intended generally to be usable flexibly
for different types of workpieces having different workpiece
heights and bore lengths.
[0010] In the case of tall workpieces or workpieces having long
bores, use is typically made of a honing unit which permits a large
stroke length since a long honing tool has to be used and the
latter has to oscillate for a long distance in the workpiece and
furthermore also has to retract out of the workpiece. The long main
body necessary for a large stroke length is expediently mounted
relatively far upwards on the support structure so that, when
required, the tall workpiece can be transported in the associated
large workpiece receptacle through to below the lower edge of the
main body. Depending on the design of the machine cladding, a
machine roof arranged at a relatively high point may be necessary.
A centre of gravity located at a relatively high point may also
arise for the arrangement, which can lead to instability during
operation.
[0011] In contrast thereto, for a low workpiece (i.e. for a
workpiece having a low workpiece height) with the short bore and
high requirements regarding the machining quality, use is
preferably made of a honing tool which is as short as possible in
order to be able to ensure as low a concentricity error as possible
at the honing tool. At the same time, the workpiece receptacle is
intended generally to be as small and light as possible so that
little mass and little mass moment of inertia result in low
resetting forces during the machining and thus in good workpiece
quality. Only a small stroke of the spindle unit is necessary, and
the spindle unit should be mounted close above the workpiece
receiving device so that the honing tool can reach the workpiece.
However, in said installation position of the main support close to
the workpiece, a large workpiece receiving device may possibly no
longer be able to be transported through below the main
support.
[0012] Depending on the workpiece to be machined in each case, on
the associated workpiece receptacle (rigid, floating, cardanic), on
the honing tool arrangement selected for this purpose (rigid honing
tool or articulated rod) and on the selected type of machine (for
example transfer machine with pallet circulation, single or two
spindle machine with geared table, rotary table machine with geared
table or NC table, special-purpose machine or the like), in each
case a vertical installation position, suitable specifically for
the workpiece to be machined, of the honing unit in the honing
machine or on the support structure thereof is conventionally
defined, which can be achieved precisely only to a limited extent,
for example by means of different grid layout in the machine
stands, honing units and optionally on a carriage plate supporting
the spindle unit. This workpiece-specific design of the honing
machine greatly restricts the possible variety of workpieces which
can be machined on the respective honing machine.
Problem and Solution
[0013] It is an object of the invention to provide a honing machine
of the type mentioned at the beginning which, without modification
to the honing unit, can machine a great spectrum of workpieces
having different workpiece heights.
[0014] To solve this problem, the invention provides a honing
machine having the features of claim 1. Advantageous refinements
are specified in the dependent claims. The wording of all the
claims is incorporated in the content of the description by
reference.
[0015] According to the claimed invention, a honing machine of the
type mentioned at the beginning is optimized in respect of a
plurality of parameters necessitated by the machine design in such
a manner that a large spectrum of workpieces having different
workpiece heights can be machined without modification work to the
honing unit having to be undertaken. A plurality of properties of
the honing machine are expediently adapted to one another here in
order to achieve this aim. Firstly, the axial installation position
of the main support on the support structure is taken into account.
The term "axial installation position" refers here to the
installation position in a direction parallel to the spindle axis.
If the spindle axis, as in preferred embodiments, is oriented
vertically, the axial installation position of the main support
thus corresponds to the installation position with respect to the
height of the main support. Furthermore, the usable length of the
linear guide system and the properties of the stroke drive are
taken into consideration. These parameters together predetermine a
stroke length and a stroke position of the honing machine.
[0016] The term "stroke position" refers here to the entirety of
all of the axial positions, which can be reached by means of the
stroke drive along the linear guide system, of the tool-side end of
the spindle shaft. This is also referred to in this application as
"spindle nose" and refers to the location of the spindle unit
closest to the workpiece. In the case of a vertically oriented
spindle axis, the stroke position thus refers to the region between
the axial position, that is the highest reachable because of the
design, and the lowest reachable axial position, closest to the
workpiece, of the tool-side end of the spindle shaft. The stroke
position thus comprises the range of all of the axial positions
that can be covered by the oscillating reciprocating movement
during the machining of the workpiece and also that region which
can be used after the machining in order to retract the honing tool
from the workpiece, and also that region which, depending on the
size of the workpieces and tools, may possibly not be reached
without a mechanical collision of honing tool and honing
machine.
[0017] The term "stroke length" refers to the axial distance
between the structurally possible workpiece-remote axial end
position of the stroke movement of the tool-side end of the spindle
shaft and the structurally possible workpiece-close axial end
position of the stroke movement of the tool-side end of the spindle
shaft.
[0018] The stroke position differs conceptually and substantively
from the stroke length. While the stroke length describes which
distance lies between a highest and the lowest point which the
stroke axis (with stroke drive and linear guide system) can
dynamically reach within the honing machine, the stroke position
describes the absolute position of said two points, i.e. the static
installation position of the main support and of the units
supported by the latter on the honing machine.
[0019] The terms "stroke length" and "stroke position" therefore
relate to the mechanical construction of the honing machine. The
workpiece-specific machining programs have to move within said
mechanical limits. This applies, inter alia, to the length of the
stroke movement during an oscillating working movement of the
honing tool. This length is also referred to here as "oscillation
length". Furthermore, the travel distances of the spindle unit out
of the workpiece into a retracted basic position have to lie within
said mechanically defined limits. In the retracted basic position,
it has to be possible, for example, to move the workpiece further
perpendicularly to the axial direction of the spindle axis, or to
remove said workpiece.
[0020] According to the claimed invention, the main support is
attached to the support structure in such a manner that a
workpiece-close end of the main support lies at a distance above a
spindle-facing limit of a selected workpiece height range.
Furthermore, the spindle unit is attached with respect to the
linear guide system in such a manner that, in the structurally
possible workpiece-close end position of a stroke movement of the
spindle unit, the tool-side end of the spindle shaft lies closer to
the workpiece height range than the workpiece-near end of the main
support.
[0021] The spindle nose can thus be moved (in so far as the
workpiece height permits this) into an axial position which lies
closer to the workpiece than the workpiece-close end of the main
support. This workpiece-close end position that is possible because
of the design must not be reached during the set-up honing process.
Particularly in the case of relatively tall workpieces, the lower
(workpiece-close) reversing point of the oscillation movement of
the spindle nose actually reached during the honing process may be
located further away from the workpiece than the workpiece-close
end of the main support.
[0022] The workpiece connection or the device for fastening a
honing tool is located at the workpiece-close end of the spindle
shaft, i.e. at the "spindle nose". The term "workpiece height
range" characterizes the height spectrum of those workpieces of
differing height that are intended to be machined with the honing
machine without modification of the latter. The spindle-facing
limit of the workpiece height range is thus defined by the height
of the tallest workpiece to be machined together with the workpiece
receptacle provided for this purpose. As viewed in the axial
direction, i.e. as viewed in a direction parallel to the spindle
axis, the main support is therefore intended to be attached in an
axial position such that the tallest workpiece to be chucked cannot
collide with the workpiece-close end of the main support when the
workpiece is transported past the main support perpendicularly to
the spindle axis. At the same time, the spindle unit is intended to
be attached with respect to the linear guide system in such a
manner that, when required, the workpiece-side end of the spindle
shaft, i.e. the spindle nose, can be moved past the workpiece-close
end of the main support in the direction of the workpiece, i.e. can
be positioned in a position closer to the workpiece than the
workpiece-close end of the main support. When a spindle axis is
oriented vertically, the axial height of the lower edge of the main
support would thus be positioned higher than the axial position of
the spindle nose at the workpiece-close reversing point of a
possible stroke movement.
[0023] If a structural compromise is observed within the scope of
these specifications, workpieces from a large workpiece height
spectrum can be machined without modification of the honing machine
being required when changing between workpieces of differing
heights and without the overall construction of the honing machine
becoming unnecessarily large.
[0024] For a honing machine with a vertically oriented spindle
axis, it is possible, for example, by optimizing stroke length and
stroke position or stroke length and installation position of the
honing unit in the honing machine for a defined height of a machine
roof, to achieve the effect that, firstly, a workpiece receptacle
of maximum size (for a relatively tall workpiece), but, secondly,
also a very low workpiece receptacle for a low workpiece to be
precisely machined) can be machined equally in one and the same
installation position of the honing unit in the honing machine
without the workpiece receptacle being unnecessarily tall for the
small workpiece or the associated honing tool being unnecessarily
long. The honing machine thereby gains a high degree of
flexibility.
[0025] At the same time, a conventionally provided great variance
in linear guide systems of differing length can be reduced to a
single standard length, and therefore only one version of a linear
guide system has to be structurally maintained. This version can be
produced for this purpose in relatively large production batches
and thus more cost-effectively with consistently high quality. The
same currently applies to other assemblies, for example to long
carriage assemblies. The mutual coordination hitherto necessary in
conventional systems of workpiece receptacles and honing tools
prior to the installation of the honing machine can be omitted, and
therefore a honing machine can basically always be constructed
identically for a predetermined workpiece height spectrum. During
the operating time of the honing machine, new or differently
configured workpieces can be retrospectively introduced into the
machining process without having to carry out a time-consuming and
costly conversion.
[0026] In addition, the honing machine can be surrounded, when
required, with a closed machine cladding which can also be closed
upwards by a machine roof. This reduces the noise which can be
emitted by the machining into the respective factory building,
prevents the penetration of dirt from the surroundings into the
honing machine and into the machining medium used (for example
honing oil or cooling lubricant) and provides the possibility of
installing an extraction system which can remove the arising
atomization of the coolant to the outside from the machining
room.
[0027] A honing machine of the type under consideration here has
only a single linear guide system, wherein a usable length of the
linear guide system and the stroke drive are configured in such a
manner that different stroke positions within a stroke position
range between a workpiece-close stroke position limit
(workpiece-close axial end position) and a workpiece-remote second
stroke position limit (axial end position) of the spindle nose and
also different stroke lengths of an oscillating stroke movement are
possible. The stroke drive and the linear guide system serve here
both for setting the stroke position and for generating the
oscillation movement with a predeterminable oscillation length.
[0028] In some embodiments, the spindle unit is mounted on a
carriage which runs on guide rails of the linear guide system. The
spindle unit can be mounted there in such a manner that the
tool-side end of the spindle shaft (the spindle nose) projects over
a workpiece-side end of the carriage to the workpiece side. The
carriage can thus be moved as far as the end of the movement
distance permitted by the linear guide system, and the spindle nose
can be moved beyond said end and optionally beyond the
workpiece-close end of the main support in the direction of the
workpiece. This is of advantage particularly for the use of short
honing tools.
[0029] However, such a carriage is not compulsory. It is also
possible to fasten the guide shoes, which are guided on guide rails
of the linear guide system, to individual fastening surfaces of the
spindle unit without the interposition of a carriage plate common
to the guide shoes. This likewise provides the possibility of
mounting the carriage unit in such a manner that, at the tool-side
end of the linear guide system, the spindle nose can be brought up
very close to the workpiece.
[0030] The honing machine is preferably designed for use of honing
tools of differing length of a honing tool group in such a manner
that, when the longest honing tool of the honing tool group is
used, a workpiece-close end of the honing tool is retracted at
least as far as the workpiece-close end of the main support when
the spindle unit is in a workpiece-remote end position of the
stroke movement. As a result, a collision-free workpiece transport
perpendicular to the spindle axis is ensured even when the longest
honing tools of the honing tool group are used.
[0031] According to the inventors' experiences, an advantageous
effect on the variability of the honing machine with simultaneously
good stability can be provided if one or more of the following
conditions are met. For example, a structurally possible projecting
length of the tool-side end of the spindle shaft over the
workpiece-close end of the main support can lie in the range from
20% to 40% of the stroke length. Alternatively or additionally, the
upper limit of the workpiece height range can be 50% to 75% of the
stroke length. Alternatively or additionally, the stroke length may
be in the range of from 70% to 90% of the length of the spindle
unit. Deviations from said dimensioning conditions may be provided
and may be expedient.
[0032] In order to be able to realize as large a stroke length as
possible with as small a length of the main support as possible,
the moving parts of the honing unit, i.e. in particular the spindle
unit and a carriage possibly provided for supporting the spindle
unit, are intended to be designed to be as short as possible in the
axial direction. It can thus be provided, for example, to design
the rotary drive and the expansion drive to be as short as possible
axially, for example by the use of direct drives which can be fully
integrated in a spindle housing. For example, the rotary drive can
be integrated in the spindle unit, i.e. can be arranged within a
spindle housing accommodating the spindle shaft. A stator of the
rotary drive can be connected to the spindle housing for rotation
therewith, while a rotor is connected to the spindle shaft for
rotation therewith.
[0033] An expansion drive for expanding the honing tool is
preferably provided, wherein the expansion drive is coupled to an
advancing rod which runs in the interior of the spindle shaft. The
expansion drive is preferably designed as an electric direct drive,
in particular as a torque motor or as a moving coil drive. An
electric direct drive can be realized in an axially short
design.
[0034] In order to be able to realize as large a stroke length as
possible with a compact design, in preferred embodiments the stroke
drive is designed as an electric linear motor with a primary part
and a secondary part which are movable relative to one another
parallel to the longitudinal direction of the longitudinal guide
system (nominally parallel to the spindle axis). The primary part
is preferably attached on the spindle unit side. A row of permanent
magnets can be arranged within the main support in order, without
an interconnected transmission or the like, to achieve a linear
movement of the primary part in relation to the secondary part,
which is provided with permanent magnets.
[0035] In preferred embodiments, the honing machine has a workpiece
transport system with a plurality of workpiece receptacles which
are selectively movable into a machining position in which a bore
which is to be machined in a held workpiece is arranged coaxially
with respect to the spindle axis. A plurality of workpieces
transportable by the workpiece transport system can thus be
machined successively at one and the same honing unit. The
transport direction preferably runs exclusively perpendicularly to
the spindle axis, and therefore the workpiece transport system does
not require a dedicated stroke axis. Owing to the favourable
geometrical design of the honing machine, workpieces of differing
heights can be transported from the workpiece height range by means
of the workpiece transport system without a collision between
workpiece and main support of the honing unit being able to
occur.
[0036] In preferred embodiments, the workpiece transport system
comprises a rotary table which is rotatable about an axis of
rotation and has a table panel which, on a partial circle about the
axis of rotation, has a plurality of workpiece receptacles for
holding a respective workpiece, which workpiece receptacles are
selectively movable by means of the rotary table into a machining
position in which a bore which is to be machined is arranged
coaxially with respect to the spindle axis. A particularly compact
design of the honing unit in the transverse direction with a large
number of workpiece receptacles which can be simultaneously
occupied can be realized with the aid of the rotary table
transfer.
[0037] In some embodiments, the spindle unit has a spindle unit
housing which has a first housing portion for accommodating the
rotary drive and a second housing portion for accommodating the
expansion drive. The spindle unit housing may be composed of a
plurality of housing parts, but is preferably a single-piece
component, which can be advantageous, inter alia, for reasons of
stability and the precise alignment of the components of the
spindle unit. Preferably, the rotary drive is accommodated in an
exchangeable first cartridge and the expansion drive is
accommodated in a second cartridge which is exchangeable
independently of the first cartridge, wherein the first cartridge
can be introduced into the first housing portion and the second
cartridge can be introduced into the second housing portion. The
two cartridges can be introducible into the spindle unit housing
from opposite sides. The movability of the spindle unit housing
within the stroke range facilitates the installation and the
exchange of cartridges.
[0038] If a honing machine according to the claimed invention is
designed for different workpiece heights from a workpiece height
spectrum of interest, then by determination of the ideal position
of the honing unit in the honing machine, a continuous
standardization is possible, permitting a significantly greater
diversity of workpieces with different workpiece heights to be
machined by means of the honing machine and at the same time
enabling the honing machine to always be constructed identically.
Furthermore, a uniformly dimensioned machine cladding can generally
be used since the machine roof thereof is not too high.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] Further advantages and aspects of the invention will emerge
from the claims and from the following description of preferred
exemplary embodiments of the invention, which are explained below
on the basis of the figures:
[0040] FIG. 1 shows an oblique perspective view of a honing machine
according to an exemplary embodiment;
[0041] FIG. 2 shows a vertical section through a honing unit
arranged on the support structure of the honing machine and
components of a rotary table transport system;
[0042] FIG. 3 shows a section along the y-z plane through a setting
unit of an alignment system according to an exemplary
embodiment;
[0043] FIG. 4 shows a section parallel to the x-y plane through the
setting unit from FIG. 3;
[0044] FIG. 5 shows an exploded illustration of the setting unit of
FIGS. 3 and 4;
[0045] FIG. 6 shows the replacement of components of an expansion
system in which the expansion drive is arranged in an exchangeable
cartridge;
[0046] FIG. 7 shows the replacement of the spindle shaft and of
other components of the spindle unit, wherein the rotary drive is
arranged in an exchangeable cartridge;
[0047] FIG. 8 shows an oblique perspective view of the cartridge
containing the rotary drive, which cartridge, on its top side, has
plug connectors for plug-type connections for the electrical and
fluidic connection of components of the cartridge; and
[0048] FIGS. 9A to 9D show special features of the available stroke
length and stroke positions of the embodiment.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
[0049] FIG. 1 shows an oblique perspective view of a honing machine
100 according to an exemplary embodiment. FIG. 2 shows a vertical
section through a honing unit arranged on the support structure of
the honing machine and components of a rotary table transport
system. In the configuration shown, the honing machine has only a
single honing unit. A second support structure with a second honing
unit for machining the same workpieces may be provided.
[0050] The honing machine 100 has a substantially rectangular
machine base 110 with a frame and a base plate which is or should
be oriented horizontally in the case of a fully set-up honing
machine. The rectangular base plate is somewhat longer in the first
direction (longitudinal direction) running parallel to the y axis
of the machine coordinate system MKS than in the second direction
(transverse direction) which is perpendicular thereto and which
runs parallel to the x axis of the machine coordinate system. Close
to the rear side 114 of the machine base, in the vicinity of one of
the longitudinal edges, there is arranged a vertical stand 120,
which is fixedly screwed to the machine base. The vertical stand
serves as a support structure 120 for a honing unit 130, which is
mounted on the support structure in the region of the front side of
the latter.
[0051] A major constituent part of the honing unit is a spindle
unit 150 in which a spindle shaft 152 is rotatably mounted. To
drive the spindle shaft, there is integrated a rotary drive or
spindle motor which is integrated into the spindle unit and which
can drive the spindle shaft about the spindle axis 155, that is to
say about the axis of rotation of the spindle shaft 152, with a
predefined rotational speed profile. The spindle shaft 152 has, at
a tool-side end 153, which is also referred to as spindle nose, a
device (tool receptacle) for the fastening of a honing tool
190.
[0052] The spindle unit 150 is mounted on the top side or front
side of a carriage plate 165. The carriage plate is supported by a
carriage box 160 which serves as the main support of the honing
unit. Between the main support 160, which is formed by the carriage
box, and the carriage plate 165 or the spindle unit supported
thereby, there is provided a linear guide system (not visible in
the illustrations) for guiding a linear stroke movement of the
spindle unit 150 relative to the main support 160. In the example,
the stroke drive has an electric linear motor with a primary part
and a secondary part which are movable relative to one another
parallel to the longitudinal direction of the longitudinal guide
system (ideally also parallel to the spindle axis 155).
[0053] In the example, the primary part, which is operated with an
electrical current, is attached to the carriage plate, or to the
spindle unit 150 which is likewise operated with current, while a
series of permanent magnets is arranged within the main support
160. A reversed arrangement is also possible.
[0054] The linear guide system has guide rails which are attached
to the main support 160. The corresponding guide shoes are arranged
on the bottom side of the carriage plate 165. There are also
embodiments in which the guide shoes, which slide on the guide
rails, are fastened to individual fastening surfaces of the spindle
unit, without the interposition of a carriage plate which is common
to the guide shoes.
[0055] The honing machine 100 is equipped with a workpiece
transport system 180 which has a rotary table or a rotary indexing
table. In the case of the illustrated rotary table transport
system, a horizontally oriented table panel 184 is provided which,
by means of a rotary drive arranged under the table panel, can be
rotated in predefined angular steps about an axis of rotation 185
which is oriented nominally vertically (parallel to the z direction
of the machine coordinate system). On a pitch circle about the axis
of rotation 185, there are provided multiple (in the example, six)
workpiece receptacles 182 for receiving one workpiece W each.
During transportation, the table panel rotates through a particular
angle (in this case 60.degree.) about the axis of rotation 185,
which is positioned fixedly in space, in order to successively
arrange in steps in each case one workpiece W in a machining
position under the honing unit 130 such that the spindle axis 155
corresponds as closely as possible to the bore axis in the
workpiece W. Ideally, all workpiece receptacles are mounted so as
to be as far as possible equally spaced apart from the axis of
rotation 185 and as far as possible with a uniform circumferential
spacing to one another. If multiple honing units or multiple honing
stations are served by the rotary table transport system 180, then
all honing units must be as far as possible aligned such that, in
any transport position, there is as small as possible a spacing
between the actual axis of rotation of the spindle motor and the
bore axis in the workpiece. This means that all honing units must
be correspondingly aligned in the honing machine.
[0056] The honing unit 130 is fastened by means of two fastening
units 210-1, 210-2 to the front side of the stand or of the support
structure 120. Here, the fastening units constitute a mechanical
connection between the stand 120 (support structure 120), which is
fixed with respect to the machine, and the main support 160 of the
honing unit 130. The vertical spacing 212, measured in the z
direction, between the effective centres of the fastening units
210-1, 210-2 amounts, in the example, to more than 30%, in
particular more than 40% and/or less than 90% or less than 80% of
the length, measured in the vertical direction, of the main support
160. The fastening units are not arranged at the outer ends of the
main support 160 but rather are offset inwards. What is
particularly advantageous is an arrangement such that the fastening
units are positioned such that the guide shoes, which are situated
on the carriage plate which supports the spindle unit, have as
small a spacing as possible to the fastening units when the spindle
unit is situated in a stroke position intended for the machining
process. Then, it is possible in particular for the dynamic forces
that arise during an oscillating stroke movement to be particularly
readily accommodated.
[0057] The fastening units 210-1 and 210-2 simultaneously function
as first setting unit 210-1 and second setting unit 210-2 of an
alignment system 200, the components of which are arranged at least
partially between the support structure 120 and the main support
160. By means of the alignment system 200, it is possible both for
the position of the spindle axis 155 to be adjusted in continuously
variable and reversible fashion along two mutually perpendicular
axes of translation, and for the setting of the orientation
(angular position) of the spindle axes to be adjusted in
continuously variable and reversible fashion in relation to two
mutually perpendicular axes of rotation. In this way, it is
possible for the spindle unit as a whole to be aligned such that
its axis (spindle axis 155) is aligned as closely as possible with
the axis of the bore to be machined.
[0058] Each of the setting units 210-1, 210-2 offers exactly two
translational setting degrees of freedom. In the case of a first
setting degree of freedom, the structural height, measured parallel
to the first direction (y direction), of the setting unit can be
varied in continuously variable and reversible fashion within
certain limits, such that the spacing 214, measured parallel to the
first direction, between the support structure 120 and the main
support 160 of the honing unit at the location of the fastening
unit can be varied. First setting elements are provided for this
purpose. In the case of the second setting degree of freedom, it is
possible for those components of the setting unit which are fixedly
connected to the main support 160 of the honing unit 130 to be
displaced in continuously variable and reversible fashion, parallel
to the second direction (x direction), relative to those components
which are fixedly connected to the support structure 120. Second
setting elements are provided for this purpose. There are
components which belong both to the first and to the second setting
elements and which thus have a dual function (for example a wedge
element discussed in more detail further below).
[0059] These two translational setting degrees of freedom, together
with the fact that the two setting units 210-1, 210-2 are arranged
with a vertical spacing 212 to one another (measured along the z
direction or the third direction), make it possible for the
position of the spindle axis 155 to be set along two mutually
perpendicular axes of translation (parallel to the first direction
and parallel to the second direction) and, independently of this,
also for the orientation of the spindle axis 155 in relation to two
mutually perpendicular axes of rotation (in each case parallel to
the first direction and to the second direction) to be set in
continuously variable and reversible fashion.
[0060] If, for example, both setting units 210-1, 210-2 are
adjusted in terms of their effective structural height such that
the spacing 214, measured parallel to the first direction, between
support structure 120 and main support 160 is changed by the same
magnitude, the result is a change in the position of the spindle
axis 155 by parallel displacement in a y-z plane, or a translation
of the spindle axis 155 in the first direction. This corresponds to
purely a change in position without a change in the
orientation.
[0061] If no change in spacing, or a different change in spacing
than that at the second setting unit 210-2, is set at the first
setting unit 210-1, this results in a change in inclination of the
spindle axis 155 within the y-z plane, which leads to a rotation of
the spindle axis about a virtual axis of rotation which runs
parallel to the second direction (x direction) perpendicular to the
y-z plane. The result is thus a change in the orientation.
[0062] If a displacement parallel to the second direction (x
direction) by the same displacement travel is set at the first
setting unit 210-1 and at the second setting unit 210-2, the result
is a parallel displacement of the spindle axis in an x-z plane or a
translation of the spindle axis 155 in the second direction. This
corresponds to purely a change in position without a change in the
orientation.
[0063] If displacement travels of unequal length are set at the
first setting unit 210-1 and at the second setting unit 210-2, this
results in an adjustment of the inclination of the spindle axis in
an x-z plane, which corresponds to a rotation about a virtual axis
of rotation which runs parallel to the first direction.
[0064] The spatial position of the virtual axes of rotation that
possibly arise is not fixed but rather varies in a manner dependent
on the ratios of the variations performed at the two setting
units.
[0065] Details of the construction of the first setting unit 210-1
or of the first fastening unit 210-1 of the alignment system 200
will now be discussed in more detail below with additional
reference to FIGS. 3 to 5. Here, FIG. 3 shows a section along the
y-z plane through the setting unit, FIG. 4 shows a section parallel
to the x-y plane, and FIG. 5 shows an exploded illustration of the
first setting unit 210-1. The second setting unit 210-2 may be of
identical or virtually identical construction.
[0066] The setting unit 210-1 comprises a base element 220 which is
composed of multiple components and which is designed for being
mounted fixedly on the support structure 120 of the honing machine
or on an adapter unit which is connected fixedly to the support
structure. Furthermore, a wedge element 230 is provided which has a
planar first wedge surface 231 facing towards the base element 220
and has a planar second wedge surface 232 which, in the assembled
state, faces towards the main support 160. The wedge surfaces 231,
232 of the relatively flat wedge enclose a wedge angle 233 of
approximately 5.degree. to 6.degree.. In the assembled state, the
planar first wedge surface 231 lies a really against a planar
sliding surface 221, facing towards said first wedge surface, of
the base element 220. A relative displacement of the wedge element
230 relative to said sliding surface 221 of the base element along
a displacement direction 238 running parallel to the x direction
(second direction) is provided by the construction, whereas
relative movements in other directions are prevented by the
construction. The actuating devices which are provided for
activating this relative displacement and which serve for
displacing the wedge element 230 in the displacement direction and
for positioning the wedge element in a target position will be
discussed in more detail further below.
[0067] The base element 220 includes a spherical socket 222, which
serves as a basis for the fastening unit and is provided for being
fixedly screwed to the support structure of the honing machine at
the fastening position provided for it. In some embodiments, an
adapter unit with suitable assembly interfaces is also interposed
between the spherical socket and the support structure. A
cylindrical pin may be used for the orientation of the spherical
socket 222 in terms of position on the support structure 120 or on
an adapter provided for connecting to the support structure. Said
cylindrical pin can define the rotative position of the spherical
socket in a fitting bore of the support structure or of an
adapter.
[0068] On the side facing towards the wedge element, there is
formed a spherically curved sliding surface 223. In the assembled
state, a spherical disc 224 lies in the spherical socket 222. Said
spherical disc has, on the side facing towards the spherical
socket, a convex spherical sliding surface 225 corresponding with
the sliding surface 223, and has, on the side facing towards the
wedge element, the planar sliding surface 221. A free rotation of
the spherical disc 224 in the spherical socket 222 is prevented by
virtue of the spherical socket having two cylindrical pins 228
which run in a groove in the spherical disc 224. Thus, only a
limited rotation about an axis of rotation running parallel to the
second direction is possible.
[0069] During the assembly process, the wedge element 230 is placed
onto the spherical disc 224. Said wedge element may be displaced
laterally in the displacement direction (parallel to the x
direction) in order to be able to set the structural height,
measured parallel to the y direction, of the setting element in
continuously variable and reversible fashion. Firstly, the angle of
the wedge element 230 should be shallow enough that it moves in the
range of self-locking. Here, this means that a change in load on
the wedge element should not trigger any lateral displacement of
the wedge element. Secondly, however, the angle of the wedge
element should also be steep enough that a sufficient range of
adjustment in the height of the wedge element is present with the
available lateral displacement travel of the wedge element 230. In
the exemplary embodiment, the wedge angle 223 is dimensioned such
that there is an integer ratio between a lateral displacement of
the wedge element and the resulting change in height of the
fastening unit or of the setting unit. A wedge with a corresponding
ratio of 1:10 has proven highly suitable, such that a displacement
by 1 mm causes a change in height by 0.1 mm.
[0070] Two tension anchors 229 are provided for facilitating the
handling of the components during the assembly process. These each
exert a slight pressure on the wedge element 230 via a helical
spring, such that said wedge element is supported on the spherical
disc 224 and thus prevents the wedge element from lifting off the
spherical disc during the assembly process.
[0071] In the fixedly installed spherical socket 222, there is
fixedly installed a substantially cuboidal holding block 226. In
the holding block, there is seated a bearing bolt 227 on which the
main support 160 can be supported during the mounting of the honing
unit 130 onto the fastening unit 210-1, in order, during the
assembly process, to compensate for the mass of the honing unit
with respect to the Earth's gravitational force. The bearing bolt
227 has a circular outer contour at its side facing towards the
honing unit. The main support 160 has, on its side facing towards
the fastening unit, a rectangular pocket or recess 162 for
receiving the bearing bolt, which in the received state ideally
forms linear contact (or, in the case of relatively great angles of
inclination, punctiform contact) with the rectangular pocket, such
that no constraint is imparted even in the event of inclination of
the honing unit.
[0072] On the upper fastening unit 210-1, the bearing bolt 227 is
fitted relatively tightly in said pocket on the main support 160,
in order already to fix the position of the honing unit in the
honing machine relatively accurately during the assembly process.
On the lower fastening unit 210-2, the pocket on the main support
160 of the honing unit is somewhat larger, such that no constraint
is imparted to the honing unit here either.
[0073] In the wedge element 230, on opposite sides of the polygonal
cutout provided for the passage of the holding block 226, there are
provided threaded bores which are oriented substantially parallel
to the second direction. Into the threaded bores, there are screwed
setting screws 240-1, 240-2 which serve as actuating elements of an
actuating device for displacing the wedge element 230 in the
displacement device 238. By means of these setting screws, the
wedge element can be displaced against the holding block 226 (which
is attached fixedly with respect to the machine) in the
displacement direction 238. The height adjustment of the fastening
element and thus the spacing adjustment (in the y direction)
between support structure and main support of the honing unit at
the location of the setting unit is effected by displacement of the
wedge element. When the desired target position has been attained,
the wedge element automatically holds this position owing to
self-locking. The wedge element can however be additionally fixed
in this position by tightening of the setting screws which act
against one another.
[0074] On the main body 160, at the location provided for the
attachment of the fastening unit or setting unit 210-1, there is
formed a planar oblique surface 164 which in the assembled state
interacts, as a sliding surface, with the second wedge surface 232.
In the main support 160 of the honing unit, there are furthermore
formed threaded bores which run parallel to the x direction and in
which setting screws 250-1, 250-2 are seated. Said setting screws
are likewise supported on the holding block 226 (which is installed
fixedly with respect to the machine). A displacement of the main
support 160 of the honing unit relative to the support structure
120, which is fixed with respect to the machine, parallel to the
displacement direction 238 is possible by actuation of the setting
screws 250-1, 250-2. Here, the planar second wedge surface 232 and
the oppositely situated planar oblique surface 164 on the main
support slide on one another. Since this is associated with a
minimal change in spacing in the y direction, the setting screws
240-1, 240-2 should also be adjusted to the same extent for the
purposes of compensation.
[0075] A configuration such that each rotation of the setting screw
results in a fixed extent of the displacement is advantageous. For
example, in the case of a thread pitch of 1 mm, one full rotation
of the setting screw 250-2 results in a displacement of 1 mm. By
re-measuring the positions of the parts with respect to one
another, the respectively set position can be read off, and the
adjustment travel that is still required can be estimated.
[0076] The basic setting of the fastening units 210-1, 210-2 is the
theoretical centre, such that, in this position, in the absence of
all manufacturing tolerances of the honing machine, the axis of the
spindle motor, that is to say the spindle axis 155, would run
exactly in alignment with the bore axis in the workpiece.
Proceeding from this central position, both the height of the
setting units parallel to the first direction (y direction) and
also the lateral offset by relative displacement parallel to the
second direction (x direction) can be reversibly set independently
of one another by means of the setting screws 240-1, 240-2 and
250-1, 250-2 respectively. A lateral displacement parallel to the x
direction arises here from the setting screws 250-1, 250-2 in the
main support. The setting of the height of the fastening unit in
the y direction arises from the setting screws or forcing-off
screws 240-1, 240-2 in the wedge element 230.
[0077] In order to vary the position of the honing unit relative to
the bore axis in the workpiece, the upper setting unit 210-1 and
the lower setting unit 210-2 are adjusted in each case in the same
direction by the same setting travel. In order to adjust the
angular position of the unit, the upper setting unit and the lower
setting unit are adjusted in opposite directions and/or to
different extents. In the case of the fastening units being set in
opposite directions and/or to different extents, an angular offset
between those wedge surfaces of the wedge elements which lie on the
spherical segments can occur owing to the different heights of the
two setting units. This angular offset can be compensated by means
of small compensation movements of the spherical discs in the
spherical sockets. Thus, the spherical bearings which are
integrated into the fastening units 210-1, 210-2 and which have the
complementary curved sliding surfaces serve as an angle
compensation device for automatically compensating angular offsets,
and stresses possibly caused as a result, in the case of adverse
setting conditions of the setting units. In the example, the radius
of curvature of the spherical sliding surfaces 223, 225 is selected
such that (in the case of the wedge element being set into its
central position) the sphere central point lies on the axis of
rotation of the spindle motor, that is to say on the spindle axis
155. Thus, possible compensation movements do not have an effect on
the position and orientation of the spindle axis.
[0078] A method for setting the machine geometry with alignment of
the spindle axis in relation to the bore axis of the bore that is
to be honed may for example progress as follows.
[0079] Firstly, the fastening units 210-1, 210-2 which serve as
setting units are fastened at their intended positions to the front
side of the support structure by means of screws. Here, the wedge
elements and the spherical discs are each brought into a central
position.
[0080] The honing unit is subsequently fitted by being mounted at
the top and bottom on the bearing bolts 227. The main support 160
of the honing unit 130 is then brought into a central position.
[0081] For an alignment operation, as long as possible a
cylindrical geometry with reference to the workpiece receptacle or
to the transport system should be provided on the workpiece
receptacle. For example, a master cylinder may be installed as an
alignment aid at the location of a workpiece receptacle of the
rotary table transport system. The cylindrical bore in the master
cylinder thus represents the bore axis in the workpiece and
produces the reference to the transport system. This step may be
performed before or after the fitting of the honing unit on the
support structure.
[0082] Thereafter, the parallelism of the axis of rotation of the
spindle motor, that is to say the parallelism of the spindle axis
with respect to the central longitudinal axis of the master
cylinder, can be set for example by setting of the setting units in
opposite directions and/or to different extents. Here, it is
preferably firstly the case that the lateral setting (parallel to
the displacement direction) is performed by means of the setting
screws in the main support, and then the frontal setting is
performed by displacement of the wedge elements.
[0083] Thereafter, the master cylinder can be dismounted, in order
to measure a possible position offset of the spindle axis with
respect to the setpoint position directly at those bores of the
transport system in which the workpiece receptacles will later be
installed.
[0084] If these measurements yield that a position offset is still
required, then the position of the axis of rotation of the spindle
motor with respect to the bore axis of the workpiece is set by
adjustment of the setting elements in opposite directions to equal
extents. Here, too, it is preferably the case that firstly the
lateral position (position in the x direction) is set and
subsequently the frontal position (position along the first
direction or y direction) is set.
[0085] When the desired target position and target orientation have
been attained with sufficient accuracy, then the setting screws of
the setting units are tightened without further displacement of the
components thereby actuated, in order to fix the relative positions
assumed.
[0086] The support structure may, as shown, be for example a
vertical stand, which possibly supports only a single honing unit.
A honing machine may have two or more such stands. The support
structure may also be a column, on the periphery of which multiple
honing units are mounted in a circumferentially offset manner (cf.
DE 20 2011 003 069 U1). Instead of the direct mounting of the
fastening units on the support structure, as illustrated, an
indirect fastening by means of an adapter provided for connecting
to the support structure is also possible.
[0087] Special features of the construction of a spindle unit 300
which is provided in some embodiments will now be described on the
basis of FIGS. 6 to 8. The spindle unit 150 of the exemplary
embodiments described above may be of identical construction to the
spindle unit 300 described below. It is however also possible for
the spindle unit 150 to have a different construction than the
spindle unit 300 described here. Aside from the spindle unit, the
illustrated components are denoted by the same reference
designations as in the preceding examples.
[0088] The spindle unit 300 has a modular construction. The spindle
unit housing 310 is constructed as a single-piece component and is
also referred to here as a monocoque housing. The substantially
tubular component, which is open at both sides, has a first housing
portion 310-1, which accommodates the rotary drive 450, and a
second housing portion 310-2, which is formed in one piece with
said first housing portion and which has a smaller inner diameter
than the first housing portion 310-1 and which is provided for
accommodating the expansion drive 550.
[0089] The rotary drive 450 is arranged in an exchangeable first
cartridge 400 and is mounted on the interior of the substantially
rotationally symmetrical cartridge sleeve 410 of the first
cartridge 400. The expansion drive 550 is arranged in a second
cartridge 500 and is mounted within the cartridge housing 510 of
the second cartridge.
[0090] The first cartridge 400 can be introduced into the first
housing portion 310-1 from below. Independently of this, the second
cartridge 500 with the expansion drive can be introduced into the
second housing portion 310-2 from above. The expansion drive is
coupled to an axially movable advancing rod 460 which, during the
assembly of the spindle unit, is introduced into an inner passage
bore of the spindle shaft 152 and, during the operation of the
honing machine, acts on an axially displaceable expansion cone
which is arranged in the interior of the honing tool.
[0091] FIG. 6 shows a configuration in which the first cartridge
400 (with rotary drive 450) has been installed into the spindle
unit housing 310 so as to be ready for operation, whereas the
second cartridge 500 with the expansion drive 550 has been removed
in an upwards direction. FIG. 7 shows a configuration in which the
second cartridge 500 with expansion drive 550 has been introduced
into its associated second housing portion 310-2, whereas the first
cartridge 400 with the rotary drive 450 has been removed from the
spindle unit housing in a downward direction.
[0092] The comparison of FIGS. 6 and 7 shows that the removal of
the two cartridges or the installation thereof is possible at
opposite sides without a large structural space requirement at the
sides, because, for the removal or for the installation of the
second cartridge 500, the carriage 165 which is displaceable on the
main support 160 can be moved downwards, whereas, for the removal
or for the installation of the first cartridge 400, the carriage
165 with the spindle unit housing 310 can move upwards, such that,
in a downward direction, there remains sufficient free space for
the removal of the first cartridge 400 without the risk of a
collision with the transport system or with workpiece holding
devices.
[0093] The single-piece spindle unit housing 310, which may be
produced for example from a torsionally resistant aluminium alloy
or from a fibre composite material, serves as a mechanical
reference for the mutual coaxial alignment of the two cartridges
400, 500 and of the components contained therein and also as a
mechanical reference for establishing the correct alignment of said
components of the spindle unit 300 in relation to the linear guide
system of the stroke drive.
[0094] To ensure that each of the cartridges is installed in the
correct alignment and in the correct axial position in relation to
the associated housing portion of the spindle unit housing,
corresponding fitting surfaces are formed on the outer sides of the
respective cartridges and the inner sides of the associated housing
portions. In FIG. 7, the centring fitting surfaces of the first
housing portion 310-1 for receiving the first cartridge 400 can be
clearly seen. Directly adjoining the bottom end side 315 of the
spindle unit housing 310, a rotationally symmetrical lower fitting
surface 312 is formed on the inner side of said spindle unit
housing. A rotationally symmetrical upper fitting surface 313 is
formed with a spacing in an upwards direction, that is to say in
the interior of the first housing portion 310-1.
[0095] An outwardly projecting flange 415 is formed in the lower
third on the cartridge housing 410 of the first cartridge 400. The
upwardly pointing flange surface of said flange serves as an axial
stop surface for the abutment against the end side 315 of the
spindle unit housing and thus defines the axial position of the
installed cartridge. Directly above the flange 415, there is
situated a wide rotationally symmetrical fitting surface 416 which
fits with the fitting surface 312. Above this, with a spacing,
there is situated a further fitting surface 417, which fits with
the upper fitting surface 313. The internally situated fit between
the fitting surfaces 313 and 417 is formed with a smaller diameter
than the external fit with the fitting surfaces 416 and 312 in the
vicinity of the flange 415. It can thus be achieved that, during
the assembly process, the respective fitting surfaces come into
contact with one another only when the first cartridge 400 has been
almost fully inserted into the spindle unit housing or the
associated housing portion, and not already at the start of the
insertion into the spindle unit housing.
[0096] A corresponding solution is also provided for the
installation of the second cartridge 500 in the second housing
portion 310-2. There, too, there are two fitting surface pairs,
which are situated so as to be spaced apart from one another, and,
on the widened head of the second cartridge 500, a stop surface 515
which, during the axial insertion of the second cartridge 500,
abuts against the upper end side 316 of the spindle unit housing
310 and thus defines the axial position of the second cartridge 500
in the spindle unit housing. Thus, the correct alignment and axial
position of the cartridges is set without further alignment work
once the insertion of the cartridges has been completed during the
mounting on the spindle unit housing.
[0097] One particular challenge consists in providing, in the
spindle unit 300, suitable electrical and fluidic connections of
the components installed in the first cartridge 400. Whereas the
components of the second cartridge 500 which accommodates the
expansion drive 550 can be contacted relatively easily directly
from above by means of suitable connectors, contacting of the
components (for example rotary drive) provided in the first
cartridge 400 from below, that is to say from the side at which the
honing tool is coupled on, is not possible or is possible only with
restrictions.
[0098] In the exemplary embodiment, connection problems for the
internal components of the first cartridge 400 are resolved by
virtue of connecting elements of suitable plug-type connections
being attached to the upper side of the first cartridge 400, that
is to say to the inner side which is to face towards the second
cartridge 500. Said connecting elements cooperate with
corresponding connecting elements of a plug-type connection on a
housing portion 318 of the spindle unit housing 310 at the stepped
transition from the relatively large diameter in the first housing
portion 310-1 to the relatively small diameter at the second
housing portion 310-2.
[0099] In the exemplary embodiment of FIG. 8, there are
automatically sealing male plug connector components of fluid
connecting elements 470 for the introduction or discharge of liquid
or gaseous fluids. Two of the fluid plug connectors serve for the
feed and discharge of cooling liquid for the cooling of the
components arranged within the first cartridge 400, in particular
of the rotary drive. These plug connectors are connected to coolant
channels 472 which run in the interior of the wall of the cartridge
housing 410 of the first cartridge and which are indicated here
merely by dashed lines. Coolant channels may for example run in
helical fashion within the cartridge housing. It is also possible
to construct a channel network with partially axially running
coolant channel portions and transverse connections. Two further
fluid connecting elements may serve for the feed and removal of
cooling lubricant to the honing tool and from the honing tool.
Gaseous fluids may also be connected. For example, a connector may
be provided for conducting sealing air through the cartridge
housing 410 of the first cartridge 400 to an outlet on the tool
side of the first cartridge.
[0100] The electrical plug contacts 475 serve for the supply of
electrical power to the rotary drive 450 and the transmission of
information relating to the rotary drive, for example from
temperature sensors. The electrical connections 480 serve for the
transmission of signals from encoders installed in the first
cartridge 400, for example of a rotary encoder of the rotary drive,
for the purposes of controlling the honing machine. The rotary
encoder may be composed of a static and a rotating part, wherein
the static part functions as a measuring head 485.
[0101] The associated plug sockets are attached to the downwardly
pointing side of the housing portion 318 at the stepped transition
between the relatively large inner diameter of the first housing
portion 310-1 and the relatively small inner diameter of the second
housing portion 310-2. The electrical and fluid connections are
automatically produced in the final phase of the insertion, when
the first cartridge 400 is inserted, in the correct rotational
position, into the associated first housing portion 310-1. To
ensure that the first cartridge can be introduced, and inserted as
far as the stop, only in a single rotational position, a
corresponding structure is provided.
[0102] Further special features of the machine concept of the
exemplary embodiment will now be discussed in conjunction with
FIGS. 9A to 9D. The honing machine may be used for the honing of
workpieces of very different workpiece heights and bore lengths
without the need for the honing machine to be modified for this
purpose. FIGS. 9A and 9B show the machining of a workpiece W1, the
workpiece height of which corresponds to the maximum height WHO of
a workpiece height range taken into consideration in the design.
The honing machine can thus machine workpieces up to this workpiece
height.
[0103] FIGS. 9C and 9D show the machining of workpieces W2 which
have a smaller workpiece height and which have only a relatively
short bore for machining.
[0104] A relatively long honing tool 190-1 is accordingly required
for the machining of the tall workpiece W1, whereas a relatively
short honing tool 190-2 can be used for the machining of the short
bore in the relatively short workpiece W2, which makes it possible
to realize small concentricity errors and thus high levels of
machining quality.
[0105] In the design of the honing unit 130, attention is paid
inter alia to an optimum axial mounting position of the main
support 160 or of the carriage box 160 on the support structure
120. Here, the main support 160 is attached to the support
structure 120 such that an end 166 close to the workpiece, that is
to say the bottom edge 166 of the carriage box or of the main
support 160, lies with a spacing above the upper boundary WHO,
facing towards the spindle unit, of the workpiece height range.
[0106] It is thus possible, during rotation of the rotary table or
of the table panel 184 thereof about the rotary table axis 185, for
even the tallest workpieces W1 to move through below the main
support 160 without collision, if the spindle unit 150 has been
retracted sufficiently far upwards. In this regard, FIG. 9A shows a
situation in which the spindle unit 150 has been moved into its
upper end position. In the example, said spindle unit is designed
such that, even in the case of the longest honing tool 190-1 being
used, the tip thereof, which faces towards the workpiece, extends
at most as far as the level (illustrated by means of a dashed line)
of the lower edge 166 of the main support, but not further in the
direction of the workpiece. In this way, firstly, free transport of
the workpieces is ensured in the case of a retracted spindle unit
(FIG. 9A), and secondly, the stroke length of the linear movement
of the spindle unit is so great that, when the spindle unit has
been moved down, the long honing tool 190-1 can machine the bore
over its entire length with an oscillating stroke. In this regard,
FIG. 9B shows the spindle unit at its bottom dead centre, close to
the workpiece, of the oscillating stroke movement.
[0107] It is important here that the spindle unit 150 can also be
moved further downwards in the direction of the workpiece if
required, as will be discussed in more detail on the basis of FIG.
9D.
[0108] It can be seen from FIG. 9C that the workpiece-facing end,
or the bottom edge 166, of the main support is arranged far above
the movement path of the relatively short workpieces W2, such that
the workpieces can be transported around the rotary table axis 185
into their respective machining position below the spindle unit
without colliding with the main support.
[0109] In the case of a short honing tool 190-2 being used for
machining the short bore of a short workpiece, the spindle unit 150
must be moved relatively far downwards or in the direction of the
workpieces. Here, FIG. 9D shows a position of the spindle unit
close to the bottom dead centre of the oscillation movement of the
honing tool 190-2 in the bore of the short workpiece W2. It can be
clearly seen in this illustration that, in this workpiece-close
position of the stroke movement of the spindle unit 150, the
tool-side end 153 of the spindle shaft 152, that is to say the
spindle nose 153 with the device for receiving the tool, is moved
downwards beyond the lower end 166 of the main support and thus
lies closer to the workpiece height range than the workpiece-close
end 166 of the main support. In the working position of FIG. 9D, it
can also be clearly seen that the tool-side end 153 of the spindle
shaft projects in a downwards direction, or in the direction of the
workpieces, beyond the workpiece-side end of the carriage plate 165
to the workpiece side. The projecting length 167, that is to say
the length by which the spindle nose 153 projects beyond the
workpiece-side end of the main support 160, may for example amount
to 10% or more or 25% or more of the total length of the spindle
unit between spindle nose and upper end of the expansion
device.
[0110] Furthermore, owing to the use of electric direct drives for
the rotary drive and the expansion drive, the spindle unit 150 is
so short in an axial direction, that is to say parallel to the
spindle axis, that, even in the stroke position most remote from
the workpiece (FIG. 9A), the upper end of the spindle unit 150 does
not project beyond the upper end of the main support 160. The
machine roof 105 can thus be attached directly above the upper end
of the main support 160, whereby an enclosure of the honing machine
which is compact even in a height direction is made possible.
[0111] Tests performed by the inventors with regard to favourable
dimensioning proportions have found that, for many practically
relevant applications or workpieces, the workpiece height range may
lie in the range from 250 mm to 500 mm, in particular in the range
from 250 mm to 400 mm. The upper boundary WHO of the workpiece
height range may thus lie for example 250 mm to 500 mm above a
reference plane, wherein the reference plane is that plane on which
the workpiece holding devices are mounted (that is to say for
example the top side of the table panel). The bottom edge 166 of
the main support may lie one or a few mm above this upper boundary.
Expedient stroke lengths may lie for example in the range from 450
mm to 700 mm, in particular in the range from 500 mm to 650 mm.
Expedient stroke positions may lie for example in the range from
150 mm to 900 mm, in particular in the range from 180 mm to 850 mm
(likewise in relation to the reference plane mentioned above).
Expedient lengths of the main support may lie for example in the
range from 1000 mm to 1500 mm, in particular in the range from 1100
mm to 1400 mm. Expedient axial lengths of the spindle unit
(measured from the spindle nose to the top side of the spindle unit
housing) may lie for example in the range from 500 mm to 900 mm, in
particular in the range from 600 mm to 800 mm. Typical tool lengths
may lie for example in the tool length range from 100 mm to 150 mm
(for the relatively short honing tools) up to 350 to 600 mm (for
the relatively long honing tools).
[0112] Considering the structurally possible projecting length 167
of the spindle nose beyond the bottom edge 166 of the main support,
this may lie for example in the range from 20% to 40% of the stroke
length, in particular in the range from 25% to 35% of the stroke
length. The upper boundary of the workpiece height range may for
example amount to 50% to 75% of the stroke length, in particular
60% to 70%. The stroke length may for example lie in the range from
70% to 90% of the length of the spindle unit. Deviations from these
dimensions and dimension proportions are self-evidently possible
and may be expedient in particular cases.
* * * * *