[0001] The present invention relates to air introduction devices including air introduction
windows mainly used for introducing cooling air for hand-held electric tools such
as electric hammers.
[0002] Known electric tools, mainly hand-held electric tools, which include electric motors
as power sources, have various measures in order to cool the electric motors with
ambient air. In many cases, an air introduction window is provided, for example, at
a rear portion of a main body housing for introducing cooling air from outside into
a main body. The cooling air introduced into the main body is moved to a front side
of the main body housing by a cooling fan or the like to cool the electric motor and
is finally discharged to the outside from a front portion of the main body housing.
In this case, the air introduction window for introducing ambient air is required
to efficiently introduce the ambient air and at the same time, to prevent intrusion
of dust, etc. as far as possible. A technique relating an air introduction window
and for preventing the dust intrusion without causing reduction in flow rate of a
cooling air for a motor is disclosed in Japanese Laid-Open Patent Publication No.
7-266260. FIG. 7 shows a known air introduction window 70 as disclosed in Japanese Laid-Open
Patent Publication No.
7-266260. The air introduction window 70 includes air passages 72 of a main body housing 71
and air passages 76 of a cover 75, which is attached to a rear portion of the main
body housing 71. The air passages 72 and the air passages 76 are alternately arranged
so as to form flow paths having crank-shaped bent portions. The air passages 72 of
the main body housing 71 and the air passages 76 of the cover 75 are formed to be
straight without being bent.
[0003] According to the known air introduction window 70, the ambient air drawn into the
air passages 76 of the cover 75 flows straight through the air passages 76 and collide
against the main body housing 71. The direction of flow of the ambient air is then
changed in left and right directions and introduced into the main body housing 71
after flowing straight through the air passages 72 of the main body housing 71. Accordingly,
because the flow paths are bent in the course of flowing from the air passages 76
of the cover 75 to the air passages 72 of the main body housing 71, it is possible
to prevent intrusion of dust, etc. into the main body housing 71.
[0004] However, according to the above-described known technique, because the flow paths,
which extend into the main body housing 71, are bent only one time, the the dust intrusion
preventing function is insufficient in some cases. It is also possible to reduce the
intrusion of dust, etc., by reducing a cross sectional area of each air passage. However,
because sufficient flow rate cannot be ensured in this case, sufficient cooling of
the electric motor may not be achieved. Further, the intrusion of dust, etc., may
be prevented by providing an additional filter, such as a net, on an outer surface
of a cover. However, this structure may cause increase in the tool length.
[0006] Therefore, there is a need in the art to provide an electric tool having an improved
dustproof performance without accompanying degradation in air introduction performance
(cooling performance) and increase in the tool length.
[0007] This object can be achieved by providing an air introduction device according to
claim 1.
[0008] One aspect includes an electric tool with an air introduction device having at least
one air introduction window. The air introduction window includes a first air path,
a second air path and a third air path provided between the first and the second air
paths. The first air path may be provided on the side of a cover of a motor housing,
and the second pair path may be provided on the side of the motor housing. At least
two of the three air paths are bent. With this structure, it is possible to increase
the number of bent path portions than with a structure in which a single bent path
is provided by arranging straight air paths to be offset from each other. As a result,
by suitably setting the cross sectional area of each path dustproof performance can
be improved without accompanying degradation in air introduction performance.
[0009] In another aspect, each of the first air path, the second air path and the third
air path has at least one bent path portion. Because all three air paths have bent
path portions, dustproof performance can be further improved.
[0010] In a further aspect, each of the first air path, the second air path and the third
air path has only one bent path portion. Therefore, ambient air is introduced into
the motor housing through the bent path portions that are three in total, the dustproof
performance can be further improved.
[0011] In a still further aspect, a brush holder unit is mounted to a rear portion of the
motor housing, and the brush holder unit includes the cover. Because the air introduction
window can be constituted by using a cover of a conventional brush holder unit, dustproof
performance can be improved without accompanying substantial increase in cost and
tool length.
[0012] Additional objects, features, and advantages, of the present invention will be readily
understood after reading the following detailed description together with the claims
and the accompanying drawings, in which:
FIG. 1 is a side view of an electric tool incorporating an air introduction device
according to a first embodiment, with an internal structure around air introduction
device shown in a vertical sectional view;
FIG. 2 is an enlarged vertical sectional view around the air introduction device according
to the first embodiment;
FIG 3 is a cross sectional view showing air paths of one of air introduction windows
of the air introduction device according to the first embodiment and schematically
showing the configurations of bent passage portions;
FIG. 4 is a cross sectional view showing air paths of one of air introduction windows
of an air introduction device according to a second embodiment;
FIG 5 is a cross sectional view showing air paths of one of air introduction windows
of an air introduction device according to a third embodiment;
FIG. 6,is a cross sectional view showing air paths of one of air introduction windows
of an air introduction device according to a fourth embodiment; and
FIG. 7 is a cross sectional view of a known air introduction window.
[0013] Each of the additional features and teachings disclosed above and below may be utilized
separately or in conjunction with other features and teachings to provide improved
air introduction devices for electric power tools. Representative examples of the
present invention, which examples utilize many of these additional features and teachings
both separately and in conjunction with one another, will now be described in detail
with reference to the attached drawings. This detailed description is merely intended
to teach a person of skill in the art further details for practicing preferred aspects
of the present teachings and is not intended to limit the scope of the invention.
Only the claims define the scope of the claimed invention. Therefore, combinations
of features and steps disclosed in the following detailed description may not be necessary
to practice the invention in the broadest sense, and are instead taught, merely to
particularly describe representative examples of the invention. Moreover, various
features of the representative examples and the dependent claims may be combined in
ways that are not specifically enumerated in order to provide additional useful embodiments
of the present teachings.
[0014] First to fourth embodiments will now be described with reference to FIGS. 1 to 6.
FIG. 1 shows an entire electric power tool 1 with an air introduction device according
to a first embodiment. In this embodiment, an electric hammer is illustrated as an
example of the electric power tool 1 that is used for a chipping operation, etc. The
electric power tool 1 has a main body 2 and a D-shaped handle portion 3. The main
body 2 includes a hammering element for hammering a bit 4 attached at a tip portion
of the main body 2, a piston reciprocally moved for imparting a hammering force to
the hammering element with compressed air, a crank mechanism for reciprocally moving
the piston, and an electric motor 10 as a power source for applying a rotational force
to the crank mechanism. All of these mechanisms and members except for the electric
motor 10 are accommodated within a cylindrical main body housing 2a. The bit 4 is
attached so as to protrude from the tip portion of the main body housing 2a. A motor
housing 10a for accommodating the electric motor 10 is integrally formed with a rear
portion of the main body 2 and a front portion of the handle portion 3 and extends
therebetween. With this embodiment, a rotational axis J of the electric motor 10 extends
perpendicular to a hammering direction of the bit 4 (i.e., the reciprocating direction
of the piston). Thus, the electric motor 10 is a vertically installed motor in this
embodiment. The basic constructions of the main body 2 with an L-shaped configuration
and the handle portion 3 are known in the prior art and thus the details will not
be described.
[0015] The electric motor 10 is an AC motor having a rotor 11 and a stator 12 and is started
by pulling a trigger switch lever (not shown) arranged on an inner peripheral side
of the handle 3. A rotor shaft 11a (output shaft) of the rotor 11 is rotatably supported
by a motor housing 10a via upper and lower bearings 13 (only the lower bearing 13
is shown in FIG. 1). A rotational axis of the rotor shaft 11a corresponds to the rotational
axis J of the electric motor 10. The lower bearing 13 is mounted to a lower portion
of the motor housing 10a.
[0016] A brush holder unit 20 is mounted on the lower portion of the motor housing 10a.
The brush holder unit 20 is an assembly in which a pair of left and right carbon brushes
(not shown) slidably contacting with a commutator 11b, and connector terminal portions
and necessary electrical wiring lines for the side of the stator 12 etc. are assembled
to a cover 21 for covering the lower portion of the motor housing 10a. An assembling
operation of the carbon brushes to the commutator 11b and a necessary wiring operation
for the stator 12 can be completed at one time when the brush holder unit 20 is mounted
to the lower portion of the motor housing 10a. The brush holder unit 20 is known in
the prior art and thus the details will not be described.
[0017] Because of the presence of the cover 21 for the brush holder unit 20, the lower portion
of the motor housing 10a has a double bottom structure (or a double wall structure).
According to this embodiment, the air introduction device includes a plurality of
air introduction windows 30 as an air inlet for introducing cooling air (ambient air)
that mainly serves to cool the electric motor 10. The air introduction device is provided
by utilizing this double bottom structure. The cooling air introduced into the motor
housing 10a via the air introduction windows 30 flows upwardly in order to cool the
electric motor 10 and then is exhausted in an ambient environment via an exhaust port
(not shown) that is provided adjacent to a rear portion of the main body housing 2a.
[0018] The details of each of the air introduction windows 30 of the air introduction device
according to this embodiment are shown in FIG. 2. In this embodiment, two groups of
three air introduction windows 30 are arranged symmetrically on the left and right
sides as viewed from the lower side in FIG. 2, in the double bottom structure formed
by the motor housing 10a and the cover 21 of the brush holder unit 20, which is attached
to the rear portion of the motor housing 10a. The number of introduction windows 30
can be increased or decreased as occasion demands. The air introduction windows 30
have the same configuration and only one air introduction window 30 will be described
in detail. The air introduction window 30 has a first air path 31 on the side of the
cover 21 and a second air path 32 on the side of the motor housing 10a. A clearance
for flow communication is formed between the cover 21 and the motor housing 10a and
serves as a third air path 33.
[0019] The first air path 31 has a first crank-shaped bent path portion. More specifically,
the first air path 31 includes inlet ports 31a (lower side ports) and outlet ports
31b (upper side ports) connected to the inlet ports 31a via crank-shaped bent passages,
which communicate with each other and jointly define the first crank-shaped bent path
portion. Similarly, the second air path 32 has a second crank-shaped bent path portion.
More specifically, the second air path 32 includes inlet ports 32a (lower side ports)
and outlet ports 32b (upper side ports) connected to the inlet ports 32a via crank-shaped
bent passages, which communicate with each other and jointly define the second crank-shaped
bent path portion. Each of the inlet ports 31a and the outlet ports 31b of the first
air path 31 as well as each of the inlet ports 32a and the outlet ports 32b of the
second air path 32 have a rectangular configuration elongated in a direction perpendicular
to the sheet of FIGS. 2 and 3.
[0020] Further, the third air path 33 has a third crank-shaped bent path portion. More specifically,
the third air path 33 is defined between the inlet ports 31b of the first air path
31 and the outlet ports 32a of the second air path 32 via crank-shaped bent passages
that define the third crank-shaped bent path portion. These features are best shown
in FIG. 3. In FIG. 3, a lower side of the cover 21 is an atmospheric side and an upper
side of the motor housing 10a is an inner side of the motor housing 10a. The motor
cooling air flows from the upper side to the lower side in FIG. 3. In this specification,
the term "crank-shaped bent path portion" or "crank-shaped bent passage" is used to
mean a path portion or a passage formed as a result of an offset (in left and right
directions in FIG. 3) between an inlet port(s) and an outlet port(s) of an air path,
so that an impinging portion(s) of air is(are) provided in the midway of the air path.
Conversely, a term "straight path" used in this specification means a path or a passage,
in which an inlet and an outlet are not offset from each other in a direction perpendicular
to the direction of flow of air into the inlet.
[0021] In this embodiment, the width (in right and left directions in FIG. 3) of each of
the inlet ports 31 a of the first air path 31 is set to be the same as the width (in
right and left directions in FIG. 3) of the outlet ports 31b. In addition, the distance
between the inlet ports 31 a of the first air path 31 is set to be the same as the
width of each of the inlet ports 31 a. Similarly, the distance between the outlet
pons 31b is set to be the same as the width of each of the outlet ports 31b. Further,
the width (in right and left directions in FIG. 3) of each of the inlet ports 32a
of the second air path 32 is set to be the same as the width (in right and left directions
in FIG. 3) of the outlet ports 32b. The distance between two adjacent inlet ports
32a of the second air path 32 is set to be the same as the width of each of the inlet
ports 32a. Similarly, the distance between the outlet ports 32b is set to be the same
as the width of each of the outlet ports 32b. Furthermore, the width of each of the
inlet ports 31a and the outlet ports 31b is the same as the width of each of the inlet
ports 32a and the outlet ports 32b. In this connection, the inlet ports 22a of the
second air path 32 are offset in right and left directions from the outlet ports 31b
of the first path 31 by a distance equal to the width of the inlet and outlet ports
31a, 31b, 32a and 32b.
[0022] The above arrangement enables to easily mold the cover 21 and the motor housing 10a
having the first path and the second path, respectively, from resin, rubber or any
other suitable material. For example, in the case that the cover 21 or the motor housing
10a is molded from resin by an injection molding process, dies having pins and movable
relative to each other are used. As the dies are separated from each other after the
molding process, the pins may form the inlet and outlet ports as well as the bent
passage portions in the molded product.
[0023] According to the air introduction window 30 as shown in FIG. 3, the ambient air,
which is introduced from the inlet ports 31a of the first air path 31, changes its
flow direction for a first time in the first air path 31 (the first bent path portion).
The ambient air exhausted from the outlet ports 31b of the first air path 31 changes
its flow direction for a second time in the third air path 33 (the second bent path
portion) communicating with the inlet ports 32a, Thereafter, the ambient air changes
its direction for a third time in the second air path 32 and is introduced into the
motor housing 10a via the outlet ports 32b and then flows upwardly to cool the electric
motor 10. Accordingly, the flow of air is bent at three points as the air flows along
the air paths from the atmospheric side of the cover 21 into the motor housing 10a
via the air introduction window 30, and therefore, the intrusion of dust can be more
efficiently prevented than in the known device. In addition, the total flow area of
the air paths 31, 32, 33 can be set to be enough, and therefore, the flow rate of
air flowing through the air introduction window 30 can be also ensured enough.
[0024] According to the above-mentioned air introduction window 30, the bent path portions
that are three in total (i.e., three layers of bent paths) are provided in the double
bottom structure formed by the motor housing 10a and the cover 21. Therefore, by setting
the flow area of each of the air paths (or air path layers) to be enough, it is possible
to obtain more improve dustproof performance without accompanying degradation in air
introduction performance.
[0025] Further, according to this embodiment, three layered bent path portions are provided
in the double bottom structure formed by the motor housing 10a and the cover 21 of
the brush holder unit 20, which is attached to the rear portion of the motor housing
10a. Because members that are normally provided in this kind of power tool can be
used for this structure, it is not necessary to incorporate additional members, such
as a filter, and therefore, it is possible to achieve the above-mentioned effect without
increase in the cost and a tool length.
[0026] Various modifications can be made to the above-described embodiment. For example,
the present invention can be incorporated by another configuration into the double
bottom structure formed by the motor housing 10a and the cover 21 of the brush holder
unit 20 as shown in FIGS. 4 to 6.
[0027] One of air introduction windows 40 of an air introduction device according to a second
embodiment is shown in FIG. 4. The air introduction window 40 is different from the
air introduction window 30 in that a third air path 41 extending between the motor
housing 10a and the cover 21 is not formed to have a bent path portion but is formed
as a straight path. The other structures are the same as the first embodiment, and
therefore, an explanation of these structures is omitted by affixing the same reference
numerals in FIG. 4 for the same or similar components of the first embodiment. Because
the third air path 41 is formed as a straight path, the outlet ports 31b of the first
air path 31 and the inlet ports 32a of the second air path 32 are not offset from
each other so that the outlet ports 31b and the inlet ports 32a are aligned with each
other with respect to left and right conditions. Therefore, the ambient air introduced
from the inlet windows 31a changes its direction of flow for one time in the first
air path 31 before the ambient air flows out of the outlet ports 31b. Afterwards,
the ambient air flows straight into the inlet ports 32a of the second air path 32
through the third air path 41 without changing the direction of flow in the third
air path 41. The ambient air introduced into the second air path 32 via the inlet
ports 32a once more changes its direction of flow in the second air path 32 and then
flows out of the outlet ports 32b into the motor housing 10a.
[0028] As described above, according to the air introduction device having the air introduction
windows 40 of the second embodiment, each introduction window 40 provides three layered
flow paths including the first, second and third air paths 31, 32, 41 in the double
bottom structure formed by the motor housing 10a and the cover 21 of the brush holder
unit 20. Two layers of the first and the second air paths 31, 32 have the crank-shaped
bent path portions. Therefore, it is possible to improve the dustproof performance
than in the known device having only one bent path portion in a single layer with
respect to the introducing direction of the ambient air.
[0029] One of air introduction windows 50 of an air introduction device according to a third
embodiment is shown in FIG. 5. The air introduction window 50 is different from the
air introduction window 30 of the first embodiment in that a first air path 51 is
not formed to have a bent path portion but is formed as a straight path. This straight
first air path 51 is formed within the cover 21 of the brush holder unit 20. The ambient
air introduced from inlet ports 51a of the first air path 51 flows straight and is
exhausted out of outlet ports 51b. The ambient air exhausted from the outlet ports
51b changes in direction of flow in two path layers (the third air path 33 and the
second air path 32) and then flows into the motor housing 10a.
[0030] As described above, according to the air introduction window 50 of the third embodiment,
because the direction of flow of air is changed at the third and the second air paths
33, 32, it is possible to obtain more improved dustproof performance than in the known
device.
[0031] One of air introduction windows 60 of an air introduction device according to a fourth
embodiment is shown in FIG. 6. The air introduction window 60 is different from the
air introduction window 30 of the first embodiment in that the second air path 61
is not formed to have a bent path portion but is formed as a straight path. According
to the air introduction window 60, the ambient air introduced into the inlet ports
31a of the first air path 31 changes for a first time in the first air path 31 and
is exhausted out of the outlet ports 31b. The ambient air exhausted from the outlet
ports 31b changes its direction of flow again at the third air path 33 and flows into
inlet ports 61a of second air path 61. The ambient air introduced into the inlet ports
61a flows straight through the second air path 61 without changing its direction of
flow and thereafter flows into the motor housing 10a via outlet ports 61b.
[0032] As described above, according to the air introduction window 60 of the fourth embodiment,
the direction of flow of air changes at two path layers of the first and third air
paths 31, 33 out of the first, second and third air paths 31, 61, 33. Therefore, the
dust intrusion can be considerably reduced compared with the case where ambient air
is introduced into the motor housing 10a after changing its direction of flow for
only one time. As a result, the air introduction window 60 is improved in the dustproof
performance.
[0033] According to the air introduction windows 40, 50, 60 of the above described second
to fourth embodiments, two air paths out of the first to third air paths 31, 32, 33;
41, 51, 61 provided in the double bottom structure formed by the motor housing 10a
and the cover 21 of the brush holder unit 20 have bent path portions. Therefore, the
intrusion of dust etc., can be more securely reduced than with a structure shown in
FIG. 7 having a single bent path portion provided between straight air paths of the
main body housing 71 and the cover 75 by shifting them to be offset in a direction
perpendicular to the flow of air entering the passages 76.
[0034] Further, because additional members, such as a mesh filter, are not necessary by
the use of the brush holder unit 20 and the cover 21, which are normally provided
in this kind of power tool, it is possible to improve a dustproof property without
increasing the cost and a tool length.
1. An air introduction device comprising at least one air introduction window (30; 40;
50; 60) for introducing air into a motor housing (10a) of a power tool (1),
characterized in that the at least one air introduction window (30; 40; 50; 60) comprises:
a first air path (31; 51) including first inlet ports (31a; 51a) and first outlet
ports (31b; 51b) connected to the first inlet ports (31a; 51a);
a second air path (32; 61) including second inlet ports (32a; 61a) and second outlet
ports (32b; 61b) connected to the second inlet ports (32a; 61a); and
a third air path (33; 41) defined between the first outlet ports (31b; 5 1b) of the
first air path (31; 51) and the second inlet ports (32a; 61a) of the second air path
(32; 61); wherein
at least two of the first to third air paths (31, 32, 41; 51, 32, 33; 31, 61, 33)
have bent path portions.
2. The air introduction device as in claim 1, wherein the motor housing (10a) has an
electric motor (10) accommodated therein and the at least one air introduction window
(30;40;50;60) is provided in a double wall structure formed by the motor housing (10a)
and a cover (21).
3. The air introduction device as in claim 1 or 2, wherein each of the first air path
(331), the second air path (32) and the third air path (33) has at least one bent
path portion.
4. The air introduction device as in claim 3, wherein each of the first air path (31),
the second air path (32) and the third air path (33) has only one bent path portion.
5. The air introduction device as in any one of claims 2 to 4, wherein :
a brush holder unit (20) is mounted to a rear portion of the motor housing (10a),
and
the brush holder unit (20) includes the cover (21).
6. The air introduction device as in claim 1, wherein:
the first air path (31; 51) includes a plurality of passages formed in a first member
(21; 22), and the second path (32; 61) includes a plurality of passages formed in
a second member (10a).
7. The air introduction device as in claim 6, wherein:
the passages of each of the first and third air pahs (31, 41) have bent passage portions
jointly defining the bent path portion.
8. The air introduction device as in claim 6, wherein the passages of one of the first
and third air paths (31, 41) have bent passage portions jointly defining the bent
path portion.
9. The air introduction device as in claim 1, wherein:
the power tool (1) further includes a cover (21) for covering the motor housing (10a);
the first air path (31; 51) is formed in the cover (21);
the third air path (33; 41) is formed in the motor housing (10a); and
the second air path (32; 61) extends across a space defined between the cover (21)
and the motor housing (10a).
10. The air introduction device as in claim 9, wherein the cover (21) is assembled with
brushes of the motor (10).
1. Luftzuführungsvorrichtung, die zumindest ein Luftzuführungsfenster (30; 40; 50; 60)
zum Zuführen von Luft in ein Motorgehäuse (10a) eines Kraftwerkzeuges (1) aufweist,
dadurch gekennzeichnet, dass
das zumindest eine Luftzuführungsfenster (30; 40; 50; 60)
einen ersten Luftpfad (31; 51), der erste Einlassöffnungen (31a; 51a) und erste Auslassöffnungen
(31b; 51 b), die mit den ersten Einlassöffnungen (31a; 51a) verbunden sind, enthält,
einen zweiten Luftpfad (32; 61), der zweite Einlassöffnungen (32a; 61a) und zweite
Auslassöffnungen (32b; 61b), die mit den zweiten Einlassöffnungen (32a; 61a) verbunden
sind, enthält, und
einen dritten Luftpfad (33; 41) aufweist, der zwischen den ersten Auslassöffnungen
(31b; 51b) des ersten Luftpfades (31; 51) und den zweiten Einlassöffnungen (32a; 61a)
des zweiten Luftpfades (32; 61) definiert ist, bei der
zumindest zwei von dem ersten bis dritten Luftpfad (31, 32, 41; 51, 32, 33; 31, 61,
33) gekrümmte Pfadbereiche aufweisen.
2. Luftzuführungsvorrichtung nach Anspruch 1, bei der das Motorgehäuse (10a) einen darin
aufgenommenen elektrischen Motor (10) aufweist und das zumindest eine Luftzuführungsfenster
(30; 40; 40; 60) in einer Doppelwandstruktur vorgesehen ist, die durch das Motorgehäuse
(10a) und eine Abdeckung (21) ausgebildet wird.
3. Luftzuführungsvorrichtung nach Anspruch 1 oder 2, bei dem jeder von dem ersten Luftpfad
(31), dem zweiten Luftpfad (32) und dem dritten Luftpfad (33) zumindest einen gekrümmten
Pfadbereich aufweist.
4. Luftzuführungsvorrichtung nach Anspruch 3, bei der jeder von dem ersten Luftpfad (31),
dem zweiten Luftpfad (32) und dem dritten Luftpfad (33) nur einen gekrümmten Pfadbereich
aufweist.
5. Luftzuführungsvorrichtung nach einem der Ansprüche 2 bis 4, bei der
eine Bürstenhaltereinheit (20) an einen hinteren Teil des Motorgehäuses (10a) montiert
ist, und
die Bürstenhaltereinheit (20) die Abdeckung (21) enthält.
6. Luftzuführungsvorrichtung nach Anspruch 1, bei der
der erste Luftpfad (31; 51) eine Mehrzahl von Passagen enthält, die in einem ersten
Bauteil (21; 22) ausgebildet sind, und der zweite Luftpfad (32; 61) eine Mehrzahl
von Passagen enthält, die in einem zweiten Bauteil (10a) ausgebildet sind.
7. Luftzuführungsvorrichtung nach Anspruch 6, bei der
die Passagen von jedem des ersten und dritten Luftpfades (31, 41) gekrümmte Passagenbereiche
aufweisen, die zusammen den gekrümmten Pfadbereich definieren.
8. Luftzuführungsvorrichtung nach Anspruch 6, bei der
die Passagen von einer von dem ersten und dritten Luftpfaden (31, 41) gekrümmte Passagenbereiche
aufweisen, die zusammen den gekrümmten Pfadbereich definieren.
9. Luftzuführungsvorrichtung nach Anspruch 1, bei der
das Kraftwerkzeug (1) weiter eine Abdeckung (21) zum Abdecken des Motorgehäuses (10a)
enthält,
der erste Luftpfad (31; 51) in der Abdeckung (21) ausgebildet ist,
der dritte Luftpfad (33; 41) in dem Motorgehäuse (10a) ausgebildet ist, und
der zweite Luftpfad (32; 61) sich quer über einen Raum erstreckt, der zwischen der
Abdeckung (21) und dem Motorgehäuse (10a) definiert ist.
10. Luftzuführungsvorrichtung nach Anspruch 9, bei dem die Abdeckung (21) mit Bürsten
des Motors (10) eingebaut wird.
1. Un dispositif d'introduction d'air comprenant au moins une fenêtre d'introduction
(30 ; 40 ; 50; 60) pour introduire de l'air dans un compartiment moteur (10a) d'un
appareil électrique (1)
caractérisé en ce que l'une au moins des fenêtres d'introduction (30; 40; 50; 60) comprend :
un premier circuit d'air (31; 51) incluant des ouvertures de première admission (31a;
51a) et des ouvertures de première sortie (31b; 51b) connectées aux ouvertures de
première d'admission (31a; 51a);
un second circuit d'air (32 ; 61) incluant des ouvertures de seconde admission (32a
; 61a) et des ouvertures de seconde sortie (32b ; 61b) connectées aux ouvertures de
seconde admission (32a ; 61a) ; et
un troisième circuit d'air (33 ; 41) défini entre les ouvertures de première admission
(31b ; 51b) du premier circuit d'air (31 ; 51) et les ouvertures de seconde admission
(32a ; 61a) du second circuit d'air (32 ; 61) ; dans lequel
au moins deux des circuits d'air du premier au troisième (31, 32, 41 ; 51, 32, 33;
31, 61, 33) ont des portions de circuit courbées.
2. Le dispositif d'introduction d'air selon la revendication 1, dans lequel le compartiment
moteur (10a) a un moteur électrique (10) agencé à cet endroit et l'une au moins des
fenêtres d'introduction d'air (30; 40; 50; 60) est fournie dans une structure à double
paroi formée par le compartiment moteur (10a) et une enveloppe (21).
3. Le dispositif d'introduction d'air selon l'une quelconque des revendications 1 ou
2, dans lequel chacun parmi le premier circuit d'air (31), le second circuit d'air
(32) et le troisième circuit d'air (33) a au moins une portion de circuit courbée.
4. Le dispositif d'introduction d'air selon la revendication 3, dans lequel chacun parmi
le premier circuit d'air (31), le deuxième circuit d'air (32) et le troisième circuit
d'air (33) a seulement une portion de circuit courbée.
5. Le dispositif d'introduction d'air selon l'une quelconque des revendications 2 à 4,
dans lequel :
un élément porte brosse (20) est monté sur la portion arrière du compartiment moteur
(10a), et l'élément porte brosse (20) inclut l'enveloppe (21).
6. Le dispositif d'introduction d'air selon la revendication 1, dans lequel :
le premier circuit d'air (31 ; 51) inclut une pluralité de passages formés dans un
premier élément (21 ; 22), et un second circuit (32 ; 61) inclut une pluralité de
passages formés dans un second élément (10a).
7. Le dispositif d'introduction d'air selon la revendication 6, dans lequel :
les passages de chacun du premier au troisième circuit d'air (31, 41) ont des portions
de passage courbées définissant conjointement la portion courbée de circuit.
8. Le dispositif d'introduction d'air selon la revendication 6, dans lequel les passages
de l'un parmi le premier et le troisième circuit d'air (31 ; 41) ont des portions
de passage courbées définissant conjointement la portion courbée de circuit.
9. Le dispositif d'introduction d'air selon la revendication 1, dans lequel :
l'appareil électrique (1) inclut en outre une enveloppe (21) pour couvrir le compartiment
moteur (10a);
le premier circuit d'air (31 ; 51) est formé dans l'enveloppe (21) ;
le troisième circuit d'air (33 ; 41) est formé dans le compartiment moteur (10a) ;
et
le second circuit d'air (32 ; 61) s'étend à travers un espace défini entre l'enveloppe
(21) et l'enveloppe moteur (10a).
10. Le dispositif d'introduction d'air selon la revendication 9, dans lequel l'enveloppe
(21) est assemblée avec des brosses du moteur (10).