U.S. patent application number 13/818933 was filed with the patent office on 2013-06-20 for hand-held machine tool.
This patent application is currently assigned to Endress + Hauser GmbH + Co. KG. The applicant listed for this patent is Rudolf Fuchs. Invention is credited to Rudolf Fuchs.
Application Number | 20130153255 13/818933 |
Document ID | / |
Family ID | 44503826 |
Filed Date | 2013-06-20 |
United States Patent
Application |
20130153255 |
Kind Code |
A1 |
Fuchs; Rudolf |
June 20, 2013 |
Hand-Held Machine Tool
Abstract
The disclosure relates to a hand-held machine tool, comprising a
drive unit, a gearbox unit, which comprises at least one input
shaft and at least one output shaft operatively connected to the
input shaft, and a tool holder, which is configured to be driven
via the output shaft of the gearbox unit in an oscillating manner
about an axis of rotational symmetry of the output shaft. A
vibration compensating unit is proposed, which comprises at least
one compensating mass which, in order to compensate for a
vibration, is driven in at least one operating state against a
direction of movement of the tool holder.
Inventors: |
Fuchs; Rudolf; (Neuhausen,
DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Fuchs; Rudolf |
Neuhausen |
|
DE |
|
|
Assignee: |
Endress + Hauser GmbH + Co.
KG
Maulburg
DE
|
Family ID: |
44503826 |
Appl. No.: |
13/818933 |
Filed: |
July 28, 2011 |
PCT Filed: |
July 28, 2011 |
PCT NO: |
PCT/EP11/63037 |
371 Date: |
February 25, 2013 |
Current U.S.
Class: |
173/162.2 |
Current CPC
Class: |
G01N 9/002 20130101;
G01N 29/022 20130101; G01N 29/40 20130101; G01N 11/16 20130101;
G01N 29/036 20130101; G01N 2291/02818 20130101; G01F 23/2965
20130101; G01N 2291/0427 20130101; G01F 23/2966 20130101; G01F
23/2967 20130101; B25F 5/006 20130101 |
Class at
Publication: |
173/162.2 |
International
Class: |
B25F 5/00 20060101
B25F005/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 3, 2010 |
DE |
10 2010 040 219.2 |
Claims
1. A hand power tool comprising: a drive unit; a transmission unit
including (i) at least one input shaft and (ii) at least one output
shaft operatively connected to the input shaft; a tool receiver
configured to be driven in an oscillating manner, via the output
shaft of the transmission unit, about a rotational symmetry axis of
the output shaft; and a vibration compensating unit including at
least one compensating mass that, in at least one operating state,
is configured to be driven contrary to a direction of motion of the
tool receiver, wherein the vibration compensation unit is
configured to compensate a vibration.
2. The hand power tool as claimed in claim 1, wherein the
transmission unit includes (i) at least one first cam mechanism
configured to drive the tool receiver, and (ii) at least one second
cam mechanism configured to drive the compensating mass.
3. The hand power tool as claimed in claim 2, wherein the first cam
mechanism and the second cam mechanism are operatively coupled to
the drive unit.
4. The hand power tool as claimed in claim 3, wherein: the first
cam mechanism includes a first eccentric element disposed on the
input shaft, and the second cam mechanism includes a second
eccentric element disposed on the input shaft.
5. The hand power tool as claimed in claim 4, wherein the first
eccentric element and the second eccentric element are offset in
relation to each other by at least substantially 180.degree..
6. The hand power tool as claimed in claim 2, further comprising:
an angled motion converter configured to operatively connect the
compensating mass of the vibration compensating unit to the second
cam mechanism.
7. The hand power tool as claimed in claim 6, wherein the
compensating mass of the vibration compensating unit and the angled
motion converter are realized in an at least partially integral
manner.
8. The hand power tool as claimed in claim 1, wherein the
compensating mass of the vibration compensating unit is rotatably
mounted on the output shaft.
Description
PRIOR ART
[0001] The invention is based on a hand power tool according to the
preamble of claim 1.
[0002] There are already known hand power tools comprising a drive
unit, a transmission unit, which has at least one input shaft and
at least one output shaft that is operatively connected to the
input shaft, and comprising a tool receiver, which can be driven in
an oscillating manner, via the output shaft of the transmission
unit, about a rotational symmetry axis of the output shaft.
DISCLOSURE OF THE INVENTION
[0003] The invention is based on a hand power tool comprising a
drive unit, a transmission unit, which has at least one input shaft
and at least one output shaft that is operatively connected to the
input shaft, and comprising a tool receiver, which can be driven in
an oscillating manner, via the output shaft, about a rotational
symmetry axis of the output shaft.
[0004] It is proposed that the hand power tool has a vibration
compensating unit, which has at least one compensating mass that,
for the purpose of compensating a vibration, in at least one
operating state, is driven contrary to a direction of motion of the
tool receiver. A "compensating mass" is to be understood to mean a
component provided to compensate vibrations, at least partially,
preferably fully, in an operating state. "Vibrations" are to be
understood to mean, in particular, unwanted motions of the hand
power tool that are caused, in particular, by moments of inertia
produced by an oscillating motion. The compensating mass according
to the invention enables vibrations to be reduced, preferably
reduced to zero, when the hand power tool is in an operating state.
As a result, advantageously, comfort in operation of the hand power
tool can be increased for a user. In addition, noises resulting
from unwanted vibrations when the hand power tool is in an
operating state can be advantageously reduced, such that,
particularly advantageously, the operating comfort can be increased
for the user. In addition, the reduction of the vibrations, in
particular the reduction of the vibrations to zero, makes it
possible to achieve an advantageously precise working result when
the hand power tool is in an operating state.
[0005] Further, it is proposed that the transmission unit has at
least one first cam mechanism, which is provided to drive the tool
receiver, and has at least one second cam mechanism, which is
provided to drive the compensating mass. A "cam mechanism" is to be
understood to mean, in particular, a mechanism by which a shape of
a moving curve is picked up by a feeler and transmitted to a
further transmission element such as, for example, to the output
shaft. Particularly preferably, the cam mechanism has at least one
eccentric element. In this context, an "eccentric element" is to be
understood to mean a component, in particular a disk-shaped
component, whose center point, and preferably also whose center of
gravity are disposed so as to be spaced apart from a rotation axis
of the component. A "disk-shaped component" is to be understood to
mean, in particular, a component whose material extent in the
radial direction is at least 10% of a diameter of the component, an
axial extent of the component preferably being less than 10% of the
diameter.
[0006] Owing to the first and the second cam mechanism, a rotary
motion of the drive unit can be easily converted into an
oscillating motion. In addition, advantageously, the transmission
unit according to the invention can be designed in an inexpensive
and particularly robust manner.
[0007] If the first cam mechanism and the second cam mechanism are
operatively coupled to the drive unit, the drive unit can drive the
first and the second cam mechanism. Consequently, only one drive
unit is required to generate two motions, in particular two
mutually opposing motions, of two components that differ from each
other. Advantageously, it is thereby possible to save structural
space, with the result that the hand power tool can be designed,
particularly advantageously, to be small and easy to
manipulate.
[0008] In addition, it is proposed that a first eccentric element
of the first cam mechanism and a second eccentric element of the
second cam mechanism are disposed on the input shaft. Since the
first eccentric element of the first cam mechanism and the second
eccentric element of the second cam mechanism are disposed on the
input shaft, an advantageously compact structural design can be
achieved. Also conceivable, however, as alternatives or in addition
to the cam mechanisms constituted by eccentric elements, are other
cam mechanisms, considered appropriate by persons skilled in the
art, for converting a rotary motion into an oscillating swivel
motion.
[0009] In a further design of the invention, it is proposed that
the eccentric elements are offset in relation to each other by at
least substantially 180.degree.. In this context, "at least
substantially 180.degree." is to be understood to mean that a first
straight line through the center point of the first eccentric
element and through the rotation axis of the input shaft, which
straight line runs perpendicularly in relation to a rotation axis
of the input shaft, and a second straight line through the center
point of the second eccentric element and through the rotation axis
of the input shaft, which straight line runs perpendicularly in
relation to the rotation axis of the input shaft, enclose an angle
that, in particular, is less than 20.degree., preferably less than
10.degree., particularly preferably less than 5.degree., the center
points of the first and the second eccentric elements being
disposed, in a radial direction of the input shaft, on mutually at
least substantially opposite sides of the input shaft. In a
particularly advantageous design, the first and the second straight
line are disposed parallelwise in relation to each other, the
center points of the first and the second eccentric element being
disposed, in the radial direction of the input shaft, on mutually
opposite sides of the input shaft. The disposition, according to
the invention, of the first and the second eccentric element
enables an imbalance of the first and the second eccentric element
to be compensated in an advantageously simple manner.
[0010] It is proposed that the hand power tool has an angled motion
converter, via which the compensating mass of the vibration
compensating unit is operatively connected to the second cam
mechanism. In this context, a "motion converter" is to be
understood to mean a component provided to convert a rotary motion
of the drive unit into an oscillating motion of the compensating
mass about the rotational symmetry axis of the output shaft.
"Angled" is to be understood to mean, in particular, a change in
the direction of extent of between 45.degree. and 135.degree.,
preferably of between 70.degree. and 110.degree., and particularly
preferably of 90.degree.. The design, according to the invention,
of the angled motion converter enables the motion converter to be
realized, advantageously, in a space-saving manner and,
consequently, an advantageously compact structural design of the
transmission unit can be achieved.
[0011] It is proposed that the compensating mass of the vibration
compensating unit and the angled motion converter are realized in
an at least partially integral manner. "Integral" is to be
understood to mean, in particular, connected by material bonding
such as, for example, by a welding process and/or adhesive bonding
process, etc. and, particularly advantageously, formed-on, such as
being produced from a casting and/or being produced by a
single-component or multi-component injection molding method.
Preferably, owing to the integral design of the motion converter
and of the compensating unit, savings in components can be made,
and as a result, advantageously, an assembly process can be
simplified.
[0012] It is further proposed that the compensating mass of the
vibration compensating unit is rotatably mounted on the output
shaft. This makes it possible to achieve a reduction in vibrations
in an advantageously effective and, at the same time, simple
manner, in particular the reduction of vibrations to zero, when the
hand power tool is in an operating state, thereby advantageously
enabling the operating comfort for the user to be increased.
DRAWING
[0013] Further advantages are given by the following description of
the drawing. The drawing shows an exemplary embodiment of the
invention. The drawing, the description and the claims contain
numerous features in combination. Persons skilled in the art will
also expediently consider the features individually and combine
them to create appropriate further combinations.
[0014] In the drawing:
[0015] FIG. 1 shows a perspective side view of a hand power tool
according to the invention,
[0016] FIG. 2 shows a schematic sectional representation of a
partial region of the hand power tool with a transmission unit
according to the invention and with a portion of a drive unit,
[0017] FIG. 3 shows a schematic sectional representation of the
transmission unit of the hand power tool according to the
invention, along the line III-III, and
[0018] FIG. 4 shows a schematic sectional representation of the
transmission unit of the hand power tool according to the
invention, along the line IV-IV.
DESCRIPTION OF THE EXEMPLARY EMBODIMENT
[0019] FIG. 1 shows a hand power tool, which can be driven in an
oscillating manner and which has a switch 38, for switching the
hand power tool on and off, integrated into a housing 36 of the
hand power tool that serves as a handle. Disposed in a front region
of the hand power tool is a tool receiver 18, with an insert tool
40 held therein. In addition, the hand power tool comprises a drive
unit 10, constituted by an electric motor, not represented in
greater detail, and a transmission unit 12. In a region that faces
away from the tool receiver 18 in a direction of main extent 42 of
the hand power tool, the hand power tool has an electric power
cable 44 for supplying electric power to the drive unit 10.
[0020] The transmission unit 12 of the hand power tool is
represented in greater detail in FIG. 2. The transmission unit 12
has an input shaft 14, which can be driven in rotation by means of
the drive unit 10 and which is operatively connected to a first and
a second cam mechanism 30, 32. The first cam mechanism 30 has a
first eccentric element 31, which is pressed on to a free end of
the input shaft 14. The second cam mechanism 32 has a second
eccentric element 33, which likewise is pressed on to the input
shaft 14. The eccentric elements 31, 33 are identical in their
structural design and are disposed with an offset of 180.degree.,
such that a center of gravity S.sub.1 of the first eccentric
element 31, corresponding to a center point of the first eccentric
element 31, and a center of gravity S.sub.2 of the second eccentric
element 33, corresponding to a center point of the second eccentric
element 33, are disposed in series in a radial direction 46 of the
input shaft 14. The first eccentric element 31 is operatively
connected to an output shaft 16 of the transmission unit 12 via a
first motion converter 48 configured in a level manner. "Configured
in a level manner" is to be understood to mean, in particular, that
the first motion converter 48 extends, at least substantially, in a
plane disposed parallelwise in relation to the input shaft 14 of
the drive unit 10 and perpendicularly in relation to the output
shaft 16 of the transmission unit 12. "At least substantially" in
this case is to be understood to mean, in particular, that the
first motion converter 48, with the plane, encloses an angle that,
in particular, is less than 15.degree., particularly preferably is
less than 5.degree.. In this exemplary embodiment, the first motion
converter 48 is parallel to the plane.
[0021] The first motion converter 48 has a first region 50 that
faces toward the insert tool 40 in the direction of main extent 42
of the hand power tool and that has a circular recess 52, into
which the output shaft 16 is pressed. Furthermore, the first motion
converter 48 has a second region 54, which extends, from an end of
the first region 50 that faces away from the insert tool 40, in the
direction of main extent 42, to the drive unit 10. The second
region 54 of the first motion converter 48 has two arms 56. Ends of
the arms 56 of the second region 54 of the first motion converter
48 that face toward the drive unit 10 engage, on opposing sides of
the first eccentric element 31, on a circumferential surface
58.
[0022] The output shaft 16 of the transmission unit 12 extends,
perpendicularly in relation to the direction of main extent 42 of
the hand power tool, as viewed from the first motion converter 48,
toward the tool receiver 18. The output shaft 16 is mounted by two
bearings 62, 64 so as to be rotatable relative to the housing 36 of
the hand power tool. The tool receiver 18 is disposed on an end of
the output shaft 16 that faces away from the first motion converter
48. The tool receiver 18 comprises a seating flange 66, which is
pressed on to the output shaft 16 and on which the insert tool 40
is seated when in a mounted state. In addition, the tool receiver
18 comprises a fastening screw 68, which, extending through the
insert tool 40, is screwed into a threaded bore, not represented in
greater detail, in the output shaft 16. When in a mounted state, a
screw head 70 of the fastening screw 68 is supported, in respect of
the insert tool 40, on a washer 72. When in a mounted state, the
insert tool 40 fixes positively relative to the output shaft
16.
[0023] A second motion converter 34, which has an angled
configuration, engages on the second eccentric element 33. The
second motion converter 34 is configured with a 90.degree. angle,
and comprises a first region 74 and a second region 76. The first
region 74 of the second motion converter 34 is disposed
parallelwise in relation to the input shaft 14 and is connected to
a vibration compensating unit 20. The second region 76 of the
second motion converter 34 adjoins an end of the first region 74
that faces away from the output shaft 16, and extends, parallelwise
in relation to the output shaft 16, in an axial direction 60 of the
output shaft, toward the input shaft 14. The second region 76 of
the second motion converter 34 has two arms 78, the free ends of
which, facing toward the input shaft 14, engage on opposing sides
of a circumferential surface 80 of the second eccentric element
33.
[0024] The vibration compensating unit 20 is constituted by a
compensating mass 22 that is realized so as to be integral with the
second motion converter 34 and disposed so as to be rotatable about
the output shaft 16. A center of gravity S.sub.3 of the
compensating mass 22 is disposed on a side of the output shaft 16
that faces toward the drive unit 10, in a radial direction 82 of
the output shaft. A center of gravity S.sub.4 of the insert tool 40
is disposed on the side of the output shaft 16 that is opposite the
center of gravity S.sub.3 of the compensating mass 22, in the
radial direction 82 of the output shaft 16.
[0025] When the hand power tool is in an operating state, the input
shaft 14, and the eccentric elements 31, 33 disposed on the input
shaft 14, are driven in rotation by the drive unit 10. The
eccentric motion of the first eccentric element 31 is taken up by
the first motion converter 48 in a plane in which a rotational
symmetry axis of the input shaft 14 is located, and which is
perpendicular to the output shaft 16. The eccentric motion of the
second eccentric element 33 is taken up by the second motion
converter 34 in a plane that extends parallelwise in relation to
the direction of main extent 42 of the hand power tool and that is
perpendicular to the output shaft 16. Produced as a result is an
oscillating motion 28 of the first and the second motion converter
34, 48 about an axis that corresponds to a rotational symmetry axis
84 of the output shaft 16.
[0026] The oscillating motion 28 of the first motion converter 48
is transmitted, via the output shaft 16, to the tool receiver 18
and to the insert tool 40 held therein. The oscillating motion 28
of the second motion converter 34 is transmitted to the
compensating mass 22, which is integrally connected to the second
motion converter 34 and rotatably mounted on the output shaft 16 of
the transmission unit 12.
[0027] Owing to the phase displacement of the oscillating motions
28 of the first and the second motion converter 34, 48, or of the
tool receiver 18 and the compensating mass 22, vibrations that are
caused by moments of inertia produced by an oscillating motion 28
of the insert tool 40 when the hand power tool is in an operating
state are compensated by the compensating mass.
[0028] FIG. 3 shows a sectional view along the line III-III. The
centers of gravity S.sub.1 and S.sub.2 of the eccentric elements
31, 33, when in the position shown, lie on a straight line that is
perpendicular to the direction of main extent 42 and parallel to
the axial direction 60. The arms 56 of the first motion converter
48 bear against opposing sides of a circumferential surface 58 of
the first eccentric element 31 in the radial direction 46 of the
input shaft 14. The arms 78 of the second motion converter 34 bear
against the circumferential surface 80 of the second eccentric
element 33 in the radial direction 46 of the input shaft 14.
[0029] FIG. 4 shows a portion of the hand power tool, in a section
along the line IV-IV. The first motion converter 48 comprises the
first region 50 having the recess 52, and comprises the second
region 54 having the two arms 56. The ends of the arms 56 engage on
the circumferential surface 58 of the first eccentric element 31,
which is represented in section. The ends of the arms 78 of the
second motion converter 34 engage on the circumferential surface 80
of the second eccentric element 33, which is likewise represented
in section.
[0030] When the hand power tool is in an operating state, a rotary
motion 26 of the drive unit 10 and of the input shaft 14 driven by
the drive unit 10 is transmitted to the first and the second
eccentric element 31, 33 that are pressed on to the input shaft 14.
The first and the second eccentric element 31, 33 in this case
describe an orbit, which is other than a circle, about a rotational
symmetry axis 86 of the input shaft 14. The ends of the arms 56, 78
of the first and the second motion converter 34, 48 each
respectively take up a component of the non-circular motion of the
first and the second eccentric element 31, 33 in a direction that
is perpendicular to the direction of main extent 42 of the hand
power tool and perpendicular to the axial direction 60 of the
output shaft 16. In this context, "non-circular" is to be
understood to mean, in particular, being at least substantially
different from a circle. This component of the non-circular motion
of the eccentric elements 31, 33 causes an opposing oscillating
motion 28 of the first and the second motion converter 34, 48 about
the rotational symmetry axis 84 of the output shaft 16.
[0031] The oscillating motion 28 of the first motion converter 48
is transmitted to the output shaft 16 pressed into the recess 52,
and to the insert tool 40 that is fastened to the output shaft via
the tool receiver 18. The oscillating motion 28 of the second
motion converter 34 is transmitted to the compensating mass 22 of
the vibration compensating unit 20 that is integrally formed on to
the second motion converter 34.
* * * * *