DE102014212595B4 - Hand-operated machine tool with air cooling - Google Patents

Abstract

The invention relates to an arrangement of a component module (11) with one or more electrical and / or electronic components in a handheld machine tool (1) comprising: - a fan device (7) with an air guide disc (72), which has a first housing region (21) of a Housing (2), which is a suction chamber with respect to the fan device (7), from a second housing portion (22) of a housing (2), which is a pressure chamber relative to the fan device (7), separated, wherein the fan device (7) is formed to cause air flow through the first housing portion (21) into the second housing portion (22) during operation of the assembly; and - an electric drive (3) arranged in the first housing region (21); wherein the component module (11) is arranged in the first housing region (21).

Description

Technical area

The invention relates to a hand-held machine tool with an electric drive, in particular measures for providing a cooling of electronic components in a hand-held machine tool.

State of the art

Hand-held machine tools, especially with electric drives, are increasingly being equipped with intelligent controls. Furthermore, the electric drives can be used as electronically commutated electrical machines such. B. synchronous machines or DC machines may be formed. In both cases, electronic components are required to operate these electrical machines.

In particular, in electronically commutated electrical machines, the electronic components include power transistors and the like, which must be cooled due to their power loss during operation of the electrical machine. Other electronic components, such. As rectifier components and capacitors, such as those required in DC machines, are often arranged on the electric machine that they are exposed to the heat of the electric machine and therefore also must be actively cooled.

In principle, it is necessary to arrange the electronic components of a hand-held machine tool as compact as possible on the electric drive. In this case, the electronic components are exposed to the heat development of the electric drive, and it must be ensured that the electronic components and the electric drive can be sufficiently cooled. For this purpose, it is often provided to generate an air flow and to guide this through the electric drive. Electronic components are often passively cooled and, for this purpose, connected to a heat sink or the like.

To provide an air flow through the electric drive of a hand-held machine tool, a fan wheel is mounted on the shaft of the electric drive, so that during operation an air flow is generated by the electric drive and optionally by a downstream gear or percussion. The fan is usually coupled to a Luftleitscheibe to a suction chamber, the z. B. inside the electric drive can be separated from a pressure chamber, which is located on the side of an output shaft or between the electric drive and the transmission.

From the DE 10 2006 000 084 A1 is a hand tool with a component module with one or more electrical and / or electronic components and with a fan device, wherein a first housing portion of a housing of the power tool as a suction chamber and a second housing portion of the housing are formed as a pressure chamber which separates from a Luftleitscheibe become. The fan device causes an air flow through the first housing portion in the second housing portion, wherein an electric drive is arranged in the first housing portion.

In the US 2008/0106159 A1 a hand tool machine is disclosed, in which the dividing wall acting as Lufleitscheibe is integrally connected to the housing of the power tool.

The in the DE 698 16 512 T2 Hand tool shown has a radiator plate mounted thereon, electronic components, which are arranged in the air flow direction behind the outlet openings of a receiving housing of the power tool.

In the WO 2009/145205 A1 the cooling of power electronics and electric drive by a special arrangement of the components and the air inlet and outlet in the housing of the electric power tool in conjunction with the air flow generated by a fan device.

It is an object of the present invention to arrange electronic components in a hand-held machine tool space-saving and to provide a way to cool the electronic components as efficiently as possible.

Disclosure of the invention

This object is achieved by an arrangement of an electronic component in an electric drive of a hand-held machine tool according to claim 1 and by the hand-held machine tool according to the independent claim 7.

Further embodiments are specified in the dependent claims.

• – eine Lüftereinrichtung mit einer Luftleitscheibe, die einen ersten Gehäusebereich eines Gehäuses, der ein Saugraum bezüglich der Lüftereinrichtung darstellt, von einem zweiten Gehäusebereich eines Gehäuses, der einen Druckraum bezüglich der Lüftereinrichtung darstellt, separiert, wobei die Lüftereinrichtung ausgebildet ist, um im Betrieb der Anordnung einen Luftstrom durch den ersten Gehäusebereich in den zweiten Gehäusebereich zu bewirken; und
• – einen in dem ersten Gehäusebereich angeordneten Elektroantrieb.

Erfindungsgemäß ist das Komponentenmodul in dem ersten Gehäusebereich angeordnet, ring- oder ringsegmentförmig ausgebildet und umgibt eine Statoranordnung des Elektroantriebs ganz oder teilweise. Weiterhin weist das Komponentenmodul eine ringförmige oder zylinderförmige Leiterplatte auf, die die Statoranordnung des Elektroantriebs umgibt und als die Luftleitscheibe ausgebildet ist.According to a first aspect, an arrangement of a component module with one or more electrical and / or electronic components is provided in a hand-held machine tool, comprising:

• - A fan device with a Luftleitscheibe, which separates a first housing portion of a housing, which is a suction chamber with respect to the fan device, from a second housing portion of a housing, which forms a pressure chamber with respect to the fan means, wherein the fan means is adapted to the operation of the arrangement to cause an air flow through the first housing portion in the second housing portion; and
• - An arranged in the first housing portion electric drive.

According to the invention, the component module is arranged in the first housing region, ring-shaped or ring-segment-shaped and surrounds a stator arrangement of the electric drive completely or partially. Furthermore, the component module has an annular or cylindrical printed circuit board which surrounds the stator arrangement of the electric drive and is designed as the air guide disk.

One idea of the above arrangement is to arrange one or more electronic components to be cooled upstream of the fan wheel, in particular in the suction chamber of an electric drive of a machine tool, such that they can be cooled by the air flowing through the electric drive. Such an arrangement of the electronic components to be cooled, the electronic components can be compactly arranged on the electric machine, without being exposed to a high temperature, either due to own heat generation or due to passive heating by the electric drive.

Furthermore, the component module can be arranged in a cooling air channel between an inner wall of the housing and the electron drive.

Furthermore, the air deflector may be formed of a thermally conductive material, in particular of a metallic material.

It can be provided that the one or more electrical and / or electronic components are arranged in the direction of the first housing region on the Lieterplatte.

The one or more electrical and / or electronic components may be disposed in a cooling air passage between an inner wall of the housing and the electron drive.

Furthermore, a fan may be arranged on a shaft of the electric drive axially on the air guide disc.

• – ein Gehäuse; und
• – die obige Anordnung.

According to one aspect, a hand-held machine tool is provided, comprising:

• A housing; and
• - the above arrangement.

Furthermore, a shaft of the electric drive may be connected to a transmission, which is provided in the second housing portion.

Brief description of the drawings

Embodiments are explained below with reference to the accompanying drawings. Show it:

1 a schematic sectional view of a machine tool with a fan assembly, in which an electronic component module is arranged with electronic components in the suction chamber of the electric machine;

2 a schematic representation of a machine tool, in which an electrical component module is arranged on the air deflector for the separation between the suction chamber and the pressure chamber; and

3 a schematic representation of an electric machine tool, wherein the air deflector is formed as a circuit board with applied thereto electrical components.

Description of embodiments

1 shows a schematic representation of an open machine tool 1 with a housing 2 , The machine tool 1 For example, it can be designed as a drill, but the arrangements described below can also be applied in a simple manner to rotary hammers, cordless screwdrivers and the like.

The machine tool 1 has an electric drive 3 which is used to drive a rotor shaft 4 is trained. The rotor shaft 4 stands with a gearbox 5 in connection, about the one with the machine tool 1 connected (not shown) tool can be operated in a suitable manner.

The electric drive 3 may correspond to a brush-commutated DC motor or an electronically commutated electrical machine. Both types of electric drives require electronic components for a desired operation, especially with variable load. In an electronically commutated electric machine as electric drive 3 is an electronic component module 11 as a power electronics with electronic components provided to a To provide control for energizing stator windings. Brush-commutated DC machines can be equipped with an electronic component module 11 , in particular with rectifier components and suppression components, such. As capacitors may be formed.

The following description refers to electronically commutated electrical machines, but is analogously applicable to other types of electric drives.

The electric drive 3 is in a first housing area 21 of the housing 2 arranged and with a stator assembly 31 provided with (not shown) stator windings. The stator arrangement 31 is formed in the shape of a cylinder, in the interior of a circular cylindrical rotor assembly 32 is arranged. The rotor arrangement 32 typically has rotor poles that are magnetized using permanent magnets or the like to provide a field magnetic field. The rotor shaft 4 is about suitable bearings 6 in the case 2 stored.

It is a fan device 7 directly on the rotor shaft 4 intended. The fan device 7 has a fan 71 and an air deflector 72 on. The air deflector 72 is transverse to the rotor shaft 4 arranged and essentially separates the first housing portion 21 of the housing 2 from a second housing area 22 of the housing 2 from.

The first housing area 21 in which the electric motor 3 is arranged, corresponds to a suction chamber of the fan device 7 , The second housing area 22 , the pressure chamber of the fan device 7 corresponds essentially to the downstream of the air deflector 72 arranged volume, in which the sucked air is conveyed. The second housing area 22 can continue with the gearbox 5 communicating so that the air flowing through the pressure space for cooling the transmission 5 can be used.

During operation of the electric machine sucks the fan device 7 from the suction chamber, in which the electric motor 3 is arranged, through inlet openings 23 in the case 2 Air from the environment and transported through the first housing area 21 or the suction chamber in the second housing area 22 or the pressure chamber in the direction of the transmission 5 , The air is from there via outlet openings 24 out of the case 2 omitted.

In essence, the inlet openings 23 of the housing 2 the air deflector 72 concerning the electric drive 3 arranged opposite. Furthermore, between the stator assembly 31 and an inner wall 25 of the housing 2 a distance provided to a cooling air duct 10 for the air sucked in for cooling.

The essentially annular air deflector 72 essentially separates the first housing area 21 , ie the suction space, from the second housing area 22 , ie the pressure chamber, from. However, the air deflector has 72 a center opening 73 on, through which the rotor shaft 4 runs. Between the outer circumference of the rotor shaft 4 and an inner periphery of the annular air guide disk 72 There is an air path through the air from the suction gram into the pressure area 22 can be promoted.

For clarity, the distance between the fan 71 and the air deflector 72 shown relatively large. The fan wheel 71 and the air deflector 72 However, as a rule, have a very small axial distance, z. B. from 0.1 to 1 mm, so that the fan 71 in operation very close to the air deflector 72 rotates. Due to the small distance between the fan 71 and the air deflector 72 only a small part of the air flows out of the second housing area 22 or the pressure chamber back through the space between the fan 71 and the air deflector 72 in the first housing area 21 or the suction chamber. Furthermore, the distance between the air deflector 72 and an end face of the stator assembly 31 or an end face of the rotor assembly 32 low, ie in the range between 0.5 mm to 5 mm.

In the cooling air duct 10 can be an electronic component module to be cooled 11 be arranged with one or more electrical or electronic components. The electronic component module 11 can thus simultaneously with the electric drive 3 through the through the fan device 7 caused airflow to be cooled. As the heat sensitivity of electrical or electronic components of the component module 11 usually higher than the thermal sensitivity of components of the electron drive 3 , such as B. the stator windings of the electric drive 3 , the arrangement is upstream of the air deflector 72 makes sense, because there the temperature of the sucked cooling air is much lower than downstream of the air deflector 72 ,

The cooling air duct 10 can the stator assembly 31 of the electric drive 3 apart from brackets for fixing the stator assembly 31 surrounded in a substantially cylindrical shape. The component module 11 can be formed corresponding annular or cylindrical and in the cooling air passage 10 be used without closing it in the axial direction. The component module 11 However, it can also be formed in another way and at a peripheral portion in the cooling air passage 10 be arranged. In particular, the component module 11 be formed ring segment, z. B. with a radially extending annular circuit board or as a cylindrical or cylindrical segment curved printed circuit board, which is completely or partially around the electric drive 3 extends. The electronic component module 11 may be provided with (not shown) heat sinks in the air flow through the cooling air duct 10 include protruding cooling elements.

The embodiment of the 2 shows an embodiment of the 1 Essentially identical machine tool 1 , where the component module 11 with the electrical or electronic components to be cooled on the side of the suction area 21 at the air deflector 72 is arranged. In particular, the component module 11 in an area on the air deflector 72 be arranged radially outward further than the stator assembly 31 lies.

The air deflector 72 can be generally made of plastic. The air deflector 72 However, it can also be made of a thermally more conductive material, such as a metal material, for. B. be formed in the form of a cooling plate. The component module 11 can do this with cooling surfaces directly on the air deflector 72 , in particular by means of a thermal paste or the like, are placed, so that the at the air deflector 72 passing air cooling the component module 11 over the air deflector 72 allows.

The embodiment of the 3 differs from the embodiment of the 2 in that the air deflector 72 itself is designed as a printed circuit board for carrying the electrical or electronic components and thereby the component module 11 itself contributes or is integrated into this. This allows a dual use of the circuit board both as Luftleitscheibe 72 as well as a carrier element of the electrical or electronic components of the component module 11 serve, thereby increasing the number of components for the machine tool 1 and thus the effort in the assembly of the machine tool 1 reduced.

Claims (8)

Arrangement of a component module ( 11 ) with one or more electrical and / or electronic components in a hand-held machine tool ( 1 ) comprising: - a fan device ( 7 ) with an air guide disc ( 72 ), which has a first housing area ( 21 ) of a housing ( 2 ), which a suction chamber with respect to the fan device ( 7 ), from a second housing area ( 22 ) of a housing ( 2 ), a pressure space with respect to the fan device ( 7 ), wherein the fan device ( 7 ) is formed in order during operation of the arrangement an air flow through the first housing portion ( 21 ) in the second housing area ( 22 ) to effect; and - one in the first housing area ( 21 ) arranged electric drive ( 3 ); characterized in that the component module ( 11 ) in the first housing area ( 21 ) is arranged, ring-shaped or ring-segment-shaped and a stator assembly ( 31 ) of the electric drive ( 3 ) completely or partially surrounds, wherein the component module ( 31 ) has an annular or cylindrical printed circuit board which the stator assembly ( 31 ) of the electric drive ( 3 ) and as the air deflector ( 72 ) is trained. Arrangement according to claim 1, wherein the component module ( 11 ) in a cooling air channel ( 10 ) between a ( 25 ) Inner wall of the housing ( 2 ) and the electron drive is arranged. Arrangement according to claim 1, wherein the air guide disc ( 72 ) is formed of a thermally conductive material, in particular of a metallic material. Arrangement according to claim 1, wherein on the circuit board, the one or more electrical and / or electronic components in the direction of the first housing portion ( 21 ) are arranged. Arrangement according to claim 1 or 4, wherein the one or more electrical and / or electronic components in a cooling air duct ( 10 ) between an inner wall ( 25 ) of the housing ( 2 ) and the electric drive ( 3 ) are arranged. Arrangement according to one of claims 1 to 5, wherein a fan wheel ( 71 ) on a rotor shaft ( 4 ) of the electric drive ( 3 ) axially on the air guide disc ( 72 ) is arranged. Hand-operated machine tool ( 1 ) comprising: - a housing ( 2 ); and - an arrangement according to one of claims 1 to 6. Hand-operated machine tool ( 1 ) according to claim 7, wherein a rotor shaft ( 4 ) of the electric drive ( 3 ) with a transmission ( 5 ) connected in the second housing region ( 22 ) is provided.

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