U.S. patent application number 14/299824 was filed with the patent office on 2014-12-18 for hand-held power tool with an electromotive drive and at least a first housing part.
The applicant listed for this patent is Robert Bosch GmbH. Invention is credited to Daniel Barth, Cornelius Boeck, Florian Esenwein, Manfred Lutz, Joerg Maute, Joachim Schadow, Manfred Schuele, Helmut Wanek.
Application Number | 20140370791 14/299824 |
Document ID | / |
Family ID | 52009691 |
Filed Date | 2014-12-18 |
United States Patent
Application |
20140370791 |
Kind Code |
A1 |
Lutz; Manfred ; et
al. |
December 18, 2014 |
Hand-Held Power Tool with an Electromotive Drive and at least a
First Housing Part
Abstract
A hand-held power tool comprises an electromotive drive that is
configured to drive an output shaft and that is positioned in a
first housing part, wherein the electromotive drive and the output
shaft define a common first axis. The hand-held power tool further
comprises an electronic system that is configured to energize the
electromotive drive and that is positioned in a second housing
part. The second housing part is elongated and includes a grip that
is distal from the electromotive drive. The second housing part
defines a second axis that is at an angle to the first axis between
60.degree. and 120.degree..
Inventors: |
Lutz; Manfred; (Filderstadt,
DE) ; Esenwein; Florian; (Leinfelden-Echterdingen,
DE) ; Maute; Joerg; (Sindelfingen, DE) ;
Schadow; Joachim; (Stuttgart, DE) ; Barth;
Daniel; (Leinfelden-Echterdingen, DE) ; Boeck;
Cornelius; (Kirchheim, DE) ; Wanek; Helmut;
(Kirchheim/Neckar, DE) ; Schuele; Manfred;
(Sulzbach-Laufen, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Robert Bosch GmbH |
Stuttgart |
|
DE |
|
|
Family ID: |
52009691 |
Appl. No.: |
14/299824 |
Filed: |
June 9, 2014 |
Current U.S.
Class: |
451/359 ;
173/217 |
Current CPC
Class: |
B24B 23/02 20130101;
B25F 5/02 20130101; B24B 23/028 20130101; B24B 55/052 20130101 |
Class at
Publication: |
451/359 ;
173/217 |
International
Class: |
B24B 23/02 20060101
B24B023/02; B24B 55/05 20060101 B24B055/05 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 12, 2013 |
DE |
10 2013 210 962.8 |
Claims
1. A hand-held power tool, comprising: a first housing part; a
second housing part; an electromotive drive configured to drive an
output shaft and positioned in the first housing part, the
electromotive drive and the output shaft defining a common first
axis; and an electronic system configured to energize the
electromotive drive and positioned in the second housing part,
wherein the second housing part is elongated and includes a grip
that is distal in relation to the electromotive drive, and defines
a second axis that is positioned at an angle in relation to the
first axis; and wherein the angle is between 60.degree. and
120.degree..
2. The hand-held power tool according to claim 1, wherein the angle
is between 80.degree. and 110.degree..
3. The hand-held power tool according to claim 1, wherein the first
housing part has a height along the first axis between 60 mm and
150 mm.
4. The hand-held power tool claim 1, wherein the second housing
part is formed by one or a plurality of housing shells, and is
fastened to the first housing part.
5. The hand-held power tool according to claim 1, wherein the
second housing part is rotatably mounted to the first housing
part.
6. The hand-held power tool according to claim 1, wherein: the
electromotive drive is a modular electromotive drive; the first
housing part includes an inner flange; and the modular
electromotive drive is fastened to the inner flange.
7. The hand-held power tool according to claim 1, further
comprising an outer flange that outwardly closes off the first
housing part.
8. The hand-held power tool according to claim 7, further
comprising: a protective cover, wherein the outer flange includes a
collar; and wherein the protective cover is attached to the
collar.
9. The hand-held power tool according to claim 1, wherein the
electromotive drive is an electronically commutated electric
motor.
10. The hand-held power tool according to claim 1, wherein the
electromotive drive is a multi-pole electromotive drive having six
or more pairs of poles.
11. The hand-held power tool according to claim 9, further
comprising a tool spindle, wherein the electronically commutated
electric motor is configured to drive the tool spindle.
12. The hand-held power tool according to claim 1, wherein the
second housing part includes a fan configured to cool the
electronic system.
13. The hand-held power tool according to claim 1, wherein the
first housing part includes at least one sensor configured to
detect a rotational position of the electromotive drive.
14. The hand-held power tool according to claim 1, wherein the
hand-held power tool is an angle grinder.
Description
[0001] This application claims priority under 35 U.S.C. .sctn. 119
to patent application no. DE 10 2013 210 962.8, filed on Jun. 12,
2013 in Germany, the disclosure of which is incorporated herein by
reference in its entirety.
[0002] The disclosure relates to a hand-held power tool with an
electromotive drive and at least a first housing part.
BACKGROUND
[0003] A hand-held power tool with an electronically commutated
electric motor, a motor directly driving a tool spindle, is known
from DE 10 2006 054 267. This hand-held power tool is difficult to
handle from an ergonomic point of view, particularly when there are
relatively high forces. Moreover, there is insufficient space
available for the components required for a higher motor
output.
SUMMARY
[0004] A hand-held power tool according to the disclosure, by
contrast, the advantage of good usability on the one hand and
additional space on the other. It is proposed that the hand-held
power tool should be equipped with an electromotive drive acting on
an output shaft. The output shaft and the electromotive drive are
arranged in a first housing part of the hand-held power tool. The
electromotive drive and the output shaft define a common first
axis. An electronic system for energizing the electromotive drive
is accommodated by a second housing part of the hand-held power
tool. The second housing part is advantageously configured as an
elongated housing which defines a second axis. The second axis
penetrates the electronic system and advantageously extends along
the second housing part in an axial direction of the second housing
part during this. In so doing, it crosses the first axis at a point
which lies on a motor shaft.
[0005] "Elongated" should be understood to mean that a particularly
axial extension of the second housing part is greater than a
length, in particular a height h of the first housing part. The
second housing part is advantageously configured as a handle. The
term "handle" should be understood to mean a component about which
at least one of a user's hands can be placed, in order to guide a
hand-held power tool. In order to achieve great flexibility in the
intended use of the hand-held power tool, the angle a enclosed by
the first axis and the second axis is advantageously between
60.degree. and 120.degree..
[0006] By means of the features indicated in the disclosure,
advantageous developments of the hand-held power tool are possible.
In this way, the handling properties are improved, particularly
when greater forces act in the region of the output shaft, when the
angle a is between 80.degree. and 110.degree., but preferably
90.degree.. The angle specification contains deviations which are
not possible and which may be caused by production tolerances.
[0007] A height h is defined as an extension of the first housing
part of the hand-held power tool in the direction of the first
axis. The height h advantageously lies between 60 mm and 150 mm,
particularly between 70 mm and 130 mm, but preferably between 80 mm
and 110 mm.
[0008] Installation space in the hand-held power tool suitable for
accommodating electric motors is thereby created, said motors being
suitable for releasing high torques and therefore being able to
work as a direct drive without the need for a gear.
[0009] If the second housing part is constructed from one or a
plurality of housing shells, good producibility is guaranteed. The
second housing part advantageously encloses the first housing part
at least in part, by overlapping said part at least partially in a
radial and/or axial direction.
[0010] The second housing part is advantageously fastened, for
example screwed, to the first housing part, so that a hand-held
power tool optimized in terms of its handling properties and
ergonomics is thereby created.
[0011] The second housing part may advantageously be rotatably
mounted in respect of the first housing part. The hand-held power
tool can therefore be used for more than one application. If the
hand-held power tool is configured as an angle grinder, for
example, it may be used through the rotatable mounting of the two
housing parts in respect of one another both for grinding and also
for cutting.
[0012] It is advantageous for the electromotive drive to be modular
in design. In this way, the drive can preferably be easily varied
in its performance design with otherwise similar conditions.
[0013] An outer flange advantageously closes off the first housing
outwardly and can easily be removed if necessary.
[0014] The outer flange advantageously exhibits a collar. In this
way, additional components of the hand-held power tool such as a
protective cover, for example, can be mounted on the outer flange
very easily.
[0015] The electromotive drive is advantageously realized by an
electronically commutated electric motor. In this way, a high
service life can be achieved for the electromotive drive. If the
electronically commutated electric motor is an external rotor
motor, the electromotive drive is robustly designed and is able to
deliver high torques from a standing position. A drive of this kind
is therefore particularly suitable for applications in which high
torques are required.
[0016] A high torque is achieved by means of a multi-pole
electromotive drive design with at least six or more pairs of
poles.
[0017] The electromotive drive advantageously works as a direct
drive. A "direct drive" should be understood to mean that the
electronically commutated motor is connected to a tool spindle
without a gear being inserted in between.
[0018] If the second housing accommodates a fan, the electronic
system can be effectively cooled. The risk of overheating is
thereby reduced.
[0019] If a sensor for detecting the rotational position of the
electromotive drive is accommodated by the first housing, the
sensor is protected from mechanical vibrations and loads, as they
are coupled via the output shaft, for example.
[0020] A series of advantages emerges if the hand-held power tool
is configured as an angle grinder without an angular gear. Hence,
for example, high electromotive drive performance coupled with low
wear and good hand-held power tool handling properties are
guaranteed.
[0021] Exemplary embodiments of a hand-held power tool according to
the disclosure are illustrated in the drawings and explained in
greater detail in the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] In the drawings:
[0023] FIG. 1 shows a first hand-held power tool according to the
disclosure as a schematic representation,
[0024] FIG. 2 shows a partial view of an electronically commutated
electric motor for a hand-held power tool according to the
disclosure as a schematic representation,
[0025] FIG. 3 shows a second exemplary embodiment of the hand-held
power tool according to the disclosure as a schematic overview
representation,
[0026] FIG. 4 shows a second partial view of the electronically
commutated electric motor for the hand-held power tool according to
the disclosure as a schematic representation.
DETAILED DESCRIPTION
[0027] The same reference numbers are used for the same components
occurring in the different exemplary embodiments.
[0028] FIG. 1 shows a first embodiment of a hand-held power tool 10
according to the disclosure with an electromotive drive 14 acting
on an output drive 12. The electromotive drive 14 is accommodated
in the exemplary embodiment in FIG. 1 by a first housing part 16 of
the hand-held power tool 10. An electronic system 18 for energizing
the electromotive drive 14 is received by a second housing part 20
of the hand-held power tool 10. The electromotive drive 14 and the
output drive 12 form a common first axis 22. The first axis 22
penetrates the output shaft 12. The second housing part 20 is
configured as an elongated housing which forms a grip 24 that is
distal from the electromotive drive 14. The second housing part 20
defines a second axis 26 which is at an angle a to the first axis
22. The second axis 26 penetrates the electronic system 18 and in
so doing advantageously extends along the second housing part 20 in
an axial direction of the second housing part 20. As can be seen
from FIG. 1, the angle a lies between 60.degree. and 120.degree.,
but particularly between 80.degree. and 110.degree.. The
realization of the angle a is theoretically depicted in FIG. 1. The
origin of the angle a lies at the point of intersection between the
two axes 22, 26. In practical terms, the realization of a would
take place via a hinge which is located on the second axis 26,
particularly in the region between the electronic system 18 and the
electromotive drive 14. The origin of the angle a then lies at the
center of the hinge.
[0029] The electromotive drive 14 comprises an electronically
commutated electric motor 28 which drives the output shaft 12. The
output shaft 12 continues with a tool spindle 32. The tool spindle
32 supports a machining tool 34. In the exemplary embodiment 1 the
hand-held power tool 10 is configured as an angle grinder. The
machining tool 34 of an angle grinder is a grinding, cutting or
roughing disk, for example.
[0030] A geometric extension of the first housing part 16 is
defined by a height h. The height h extends along the first axis 22
between 60 mm and 150 mm, particularly between 70 mm and 130 mm,
but preferably between 80 mm and 110 mm. Within the height h lies a
length l of a rotor 36 belonging to the electromotive drive 14. The
electromotive drive 14 is configured as a so-called external rotor
motor in which the length l of the rotor 36, among other things,
but also the diameter d of the rotor 36 determine the torque that
can be transmitted to the output shaft 12 by the electromotive
drive 14.
[0031] The second housing part 20 is constructed from at least one
housing shell 38. The housing shell 38 is joined to a further
housing shell not shown in the FIG. 1, for the purposes of
providing an overview, to form the handle 24. The dividing plane
between both housing shells lies in the image plane of an observer
in this case. The second housing part 20 partially encloses the
first housing part 16, in which a first wall 40 belonging to the
second housing part 20 is pushed via a second wall 42 belonging to
the first housing part 16 and fastened thereto. The first wall 40
runs flush to the second wall 42. The connection of both housing
parts 16, 20 usually takes place by screwing. It is also
conceivable, however, that both housing parts 16, 20 are connected
by other joining methods such as riveting, welding or adhesion.
[0032] The second housing part 20 is mounted rotatably with respect
to the first housing part 16. A 0.degree. position between the two
housing parts 16, 20 is depicted in FIG. 1. A 90.degree. position
is achieved by turning the first housing part 16 or the second
housing part 20 through 90.degree. in or against the line of vision
of an observer by loosening or tightening a fixing device not shown
in greater detail.
[0033] The electromotive motor 14 is, as can be seen from FIG. 1,
modular in design. It contains a stator 50 with windings 52 and the
rotor 36 with permanent magnets 48. As shown in FIGS. 1 and 3, stop
elements are configured as so-called screw bosses 58 on a first
wall 56 in the first housing part 16. The first wall 56 is part of
the first housing part 16 on the side facing away from the
machining tool 34. An inner flange 62 is accommodated by the first
housing part 16, in which it is arranged on the screw bosses 58 and
fastened. The inner flange 62 exhibits through-holes 64 for
fastening, through which fastening means are inserted. The
fastening means are usually screws, so that the inner flange 62 is
screwed onto the first housing part 16.
[0034] An outer flange 66 closes the first housing part 16
outwardly at the output end. The output end in this case should be
understood to mean the end of the output shaft 12 on which the
machining tool 34 is mounted.
[0035] The outer flange 66 has a collar 68, to which a protective
cover 70 can be attached.
[0036] The electromotive drive 14 is realized by an electronically
commutated electric motor 28. FIG. 2 shows a section through an
external rotor motor. In motors of this kind, the magnetic field is
generated by permanent magnets 48 which are arranged in the rotor
36. A stator packet 50 supports the windings 52. When commutating
is necessary, the angle position of the permanent magnet 48 is
detected in the rotor 36 via one or a plurality of sensors 54 and
evaluated by the electronic system 18. Using the angle setting of
the rotor 36 and the desired direction of rotation, the
corresponding windings 52 are energized by the electronic system
18, in order to generate the required torque. It is also
conceivable, however, that the commutating takes place in a
sensorless manner through the detection of a counter-voltage
triggered in the stator windings.
[0037] The electronically commutated electric motor 28 drives the
spindles 32 directly. "Directly" should be understood to mean that
the electronically commutated electric motor 28 is connected to the
tool spindle 32 without the insertion of a gear.
[0038] In a further exemplary embodiment of the hand-held power
tool 10 according to the disclosure which is shown in FIG. 3, the
spindle 32 forms a separate component to the motor shaft 30. The
spindle 32 is connected to the motor shaft via a coupling part 31.
In order to transfer the torque from the motor shaft 30 to the tool
spindle 32, the coupling part 31 has internal toothing 33 on the
inside which engages with the external toothing 37 on the motor
shaft.
[0039] The electronically commutated electric motor 28 is, as shown
in detail in FIG. 4, of multi-pole design and may exhibit six or
more pairs of poles. The number of pairs of poles is the number of
magnetic poles 74. A pair of poles is formed from two poles 74. The
number of pairs of poles determines, as does the frequency, the
speed and torque of the electric motor 28. The torque to be
achieved increases to a disproportionately small degree up to a
certain limit with the number of pole pairs. This should be
particularly observed in relation to the design of electric motors
28.
[0040] In the second housing part 20, as shown in FIG. 1, a fan 72
for cooling the electronic system 18 is accommodated between the
electronic system 18 and the first housing part 16. The fan 72 may
have its own drive which drives the fan 72. Since the electronic
system 18 is more powerful in the case of hand-held power tools 10
with electronically commutated electric motors 28 and is of larger
design, both in terms of size and volume, than in the case of brush
motors, the cooling of the electronic system 18 plays an
increasingly important part.
[0041] As shown in FIG. 4, the first housing part has a sensor 54
for detecting the rotational position of the rotor 36. The sensor
54 measures the angle position of the rotor 36. The electronic
system 18 evaluates the signals and energizes the stator windings
52 according to the result.
[0042] The hand-held power tool 10 is configured as an angle
grinder without an angular gear in the exemplary embodiment. It is
also conceivable for other applications, such as orbital sanders or
similar, to be used.
* * * * *