Handheld power tool, fanless power supply unit and tool system

A hand-held power tool, in particular a hammer drill or combination hammer, is disclosed. The power tool includes a tool housing which has a receiving recess designed to replaceably receive a storage battery or a power supply unit. The hand-held power tool further includes an electric drive motor having a cooling fan and a first vent portion which is located on the tool housing outside the receiving recess and through which a volume flow generated by the cooling fan can be guided. The tool housing has a second vent portion which is different from the first vent portion and which is located in the receiving recess and through which the volume flow generated by the cooling fan can be at least partially guided.

This application claims the priority of International Application No. PCT/EP2015/078015, filed Nov. 30, 2015, and European Patent Document No. 14195557.5, filed Dec. 1, 2014, the disclosures of which are expressly incorporated by reference herein.

BACKGROUND AND SUMMARY OF THE INVENTION

The present invention relates to a handheld power tool, particularly a hammer drill or combination hammer. The handheld power tool has a tool housing, which has a receiving recess designed for replaceably receiving a storage battery or a power supply unit. The handheld power tool also has an electric drive motor with a cooling fan and a first vent section arranged on the tool housing outside of the receiving recess. A volume flow generated by the cooling fan of the handheld power tool can be guided through the first vent section. In this way, the electric drive motor of the handheld power tool, which generates heat when operating, can be cooled.

Handheld power tools, particularly a hammer drill or combination hammer, can be supplied with electrical energy either by a storage battery or a power supply unit, when these are connected to the handheld power tool. To this end, the power supply unit has a power cable, which establishes a connection to a mains power supply source (also referred to as a power outlet).

The present invention also relates to a fanless power supply unit for a handheld power tool, wherein the fanless power supply unit is designed for the replaceable accommodation within a receiving recess of a handheld power tool.

Furthermore, the present invention relates to a tool system having a handheld power tool and a fanless power supply unit.

It is the object of the present invention to provide a handheld power tool, a power supply unit, as well as a tool system with improved cooling capacity.

In regard to the handheld power tool, the task is solved by the tool housing having a second vent section that differs from the first vent section, the second section being arranged within the receiving recess and through which the volume flow generated by the cooling fan can at least be partially guided.

Advantageously, a volume flow generated by the cooling fan of the handheld power tool can now be guided at least partially through the second vent section into the receiving section and be used there for cooling tasks.

In a preferred design, the second vent section is provided in such a manner that a storage battery with a closed surface (tool storage battery of the prior art) held in the receiving recess seals the second vent section. In this way, a closed-surface storage battery held in the receiving recess can be forced-cooled (by a volume flow generated by the cooling fan and flowing through the first vent and past the storage battery via the second vent section).

Preferably, the first and/or second vent section is/are open toward ambient air when the receiving recess is empty. In a particularly preferred manner, the receiving recess is designed for the tool-free replaceable receiving of a storage battery or power supply unit.

It has proven itself to be advantageous when the first vent section is arranged on the housing in such a manner that a volume flow portion generated by the ventilation fan and passing through the first vent section flows axially to a ventilation axis of the ventilation fan. Preferably, the second vent section is arranged on the housing in such a manner that a volume flow portion generated by the ventilation fan and flowing through the second vent section flows transversely to the ventilation axis of the cooling fan.

In a particularly advantageous enhancement, the handheld power tool has a flow control means that is designed to distribute, as a function of the storage battery or power supply unit held in the receiving recess, a volume flow generated by the cooling fan between the first and second ventilation sections. A higher volume flow portion through the first vent section can be assigned to storage battery operating mode and higher volume flow portion through the second vent section can be assigned to power supply unit operating mode of the handheld power tool.

Preferably, the flow control means is designed as an externally operated change-over gate. In a first switch position, the externally operated change-over gate can close off the first vent section. Preferably, in a second switch position, the flow control means designed as an externally operated change-over gate can close off the second vent section.

It has proven itself to be advantageous if the first vent section and the second vent section belong to vents that differ from each other. Alternatively, the first vent section and the second vent section can belong to the same vent. Preferably, the first vent section and the second vent section are arranged essentially perpendicular to each other.

In regard to the fanless power supply unit, the present task is solved in that the fanless power supply unit has an inner ventilation channel open to the environment. Via this ventilation channel, the fanless power supply unit, when it is held in a receiving recess, of a handheld power tool, designed for the replaceable accommodation of the power supply unit, can be forced-cooled by means of a volume flow generated by the ventilation fan of the handheld power tool.

Preferably, the inner ventilation channel runs between a front vent and a rear vent of the power supply unit. These can be arranged on opposite end faces of the power supply unit. In a particularly preferred manner, the front vent is arranged on the power supply unit in such a manner that when the power supply unit is held in the receiving recess, the front vent is essentially congruent with the second vent section.

The invention includes the knowledge that a volume flow generated by a cooling fan of a handheld power tool, particularly in the form of aspirated cooling air, can be used for cooling a power supply unit designed for the replaceable accommodation in a receiving recess having an inner ventilation channel open to the environment according to the invention. In this way, one can forego an additional cooling fan in the power supply unit, by means of which one can construct a power supply unit in a particularly compact and cost-effective manner. This also has the advantage that a power supply unit having the same external dimensions can be designed to be significantly more powerful.

In a particularly preferred enhancement, the fanless power supply unit has a closing element, which is designed to effect an at least partial closing of a first vent section arranged outside of the receiving recess of the handheld power tool, when the fanless power supply unit is held in the receiving recess. In this way, a larger portion of the volume flow generated by the ventilation fan can be directed through the second vent section and thereby be used for cooling.

The closing element may be designed as a projecting sealing plate, which covers the first vent section of the handheld power tool. In this way, a particularly simple and robust closing element can be provided. The closing element designed as a projecting sealing plate may have a rubber seal, which is arranged in such a manner that it surrounds and/or seals the first vent section when the fanless power supply unit is held in the receiving recess.

The closing element can be a sliding element, which is designed to switch over an externally operated change-over gate provided in the handheld power tool from a second switch position to a first one. Preferably, one can thereby open a second vent section arranged inside the receiving recess of the handheld power tool toward the inner ventilation channel of the fanless power supply unit so that the fanless power supply unit is forced-cooled via the second vent section. The closing element can be designed as a sliding rod or a sliding bar for example. Preferably, the sliding element is arranged on the power supply unit and designed in such a manner that it engages in the housing of the handheld power tool when the fanless power supply unit is held in the receiving recess. The tailless power supply unit can be designed for the tool-free replaceable accommodation in a receiving recess of a handheld power tool.

In regard to the tool system, the present task is solved by a tool system, which has a handheld power tool described above and a fanless power supply unit described above. Preferably, the tool system also has a storage battery, which is designed for the replaceable accommodation in a receiving recess of a handheld power tool.

Other advantages emerge from the following description of the drawings. The drawings depict various embodiments of the present invention. The drawings, the description, and the claims contain numerous features in combination. A person skilled in the art will appropriately consider the features individually and bring them together into other reasonable combinations.

In the drawings, identical and similar components are labeled with the same reference sign.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1depicts a storage battery200according to the prior art, which has a closed surface. Storage battery200is designed for the tool-free replaceable accommodation in a non-depicted receiving recess, wherein a depiction of the attachment means was intentionally omitted here.

A fanless power supply unit300is shown in perspective inFIG. 2and has an inner ventilation channel310, by means of which fanless power supply unit300can be forced-cooled. As one can see inFIG. 2, inner ventilation channel310runs between a front vent311and a rear vent312, which are arranged on opposite end faces of power supply unit300. When fanless power supply unit300is used as intended, a volume flow aspirated via a non-depicted cooling fan can flow through rear vent312into inner ventilation channel310to be guided out of fanless power supply unit300out of front vent311, which is arranged on the front side of fanless power supply unit300and intended to be in contact with a second vent section of a non-depicted handheld power tool.

A tool system500inFIG. 3has a handheld power tool100, in this case a hammer drill. Handheld power tool100has a tool housing90, which has a receiving recess80designed for the replaceable holding of a storage battery200. As one can see inFIG. 3, handheld power tool100has an electric drive motor70with a cooling fan60. On tool housing90, there is arranged outside of receiving recess80a first vent section50. A second vent section40is arranged on tool housing90in such a manner that closed-surface storage battery200held in receiving recess80seals second vent section40. In this case, first vent section50and second vent section40belong to different vents, which are arranged perpendicular to each other on tool housing90.

Volume flow V aspirated through cooling fan60now flows only through first vent section50, since second vent section40is sealed by replaceable closed-surface storage battery200held in receiving recess80. Advantageously, sealed second vent section40already results in forced cooling of storage battery200by means of portions of volume flow V, which flow along second vent section40past storage battery200, but do not flow through storage battery200.

InFIG. 4, a tool system500according to the invention has a handheld power tool100, which corresponds to handheld power tool100described in reference toFIG. 3.

FIG. 4depicts a fanless power supply unit300according to the invention, which is already located in the proximity of a receiving recess80, yet is not completely held in the recess. Fanless power supply unit300ofFIG. 4has a sealing element designed as a projecting sealing plate320, which is intended to cover first vent section50of machine tool100. As one can see inFIG. 4, inner ventilation channel310runs between front vent311and rear vent312of fanless power supply unit300. As one can also see inFIG. 4, front vent opening311of power supply unit300is arranged on power supply unit300in such a manner that when power supply unit300is held in receiving recess80, front vent311is congruent with second vent section40.

FIG. 5depicts tool system500fromFIG. 4, wherein fanless power supply unit300is now completely held in receiving recess80. The sealing element, designed as a projecting sealing plate320, of fanless power supply unit300, now completely covers first vent section50of tool housing90so that a volume flow V, which is generated by cooling vent60driven by means of electric drive motor70, cannot pass through the first vent section. Instead, volume flow V flows entirely through second vent section40, wherein aspiration via rear vent312of power supply unit300occurs.

As indicated inFIG. 5by arrows in the region of power supply unit300, the aspirated volume flow flows through inner ventilation channel310of power supply unit300to cool the latter. Subsequently, volume flow V flows through second vent section40into tool housing90of the handheld power tool to also be simultaneously used for cooling electric drive motor70. The subsequent course of volume flow V is not further depicted for the sake of simplicity. Typically, there is provided on tool housing90in the upper region of the chuck an additional vent through which volume flow V can escape from the housing.

FIG. 6depicts another embodiment of a tool system500according to the invention. Handheld power tool100has a flow control means designed as an externally operated change-over gate20. The flow control means designed as an externally operated change-over gate20is designed to distribute, as a function of power supply unit300being held in receiving recess80, a volume flow V generated by cooling fan60between first vent section50and second vent section40. In second switch position20N of externally operated change-over gate20, second vent section40is essentially fully closed.

As one can also see inFIG. 6, fanless power supply unit300has a sealing element designed in this case as a sliding element330, which is designed to effect a sealing of first vent section50arranged outside of receiving recess80of handheld power tool100, when fanless power supply unit300is held in receiving recess80. Since fanless power supply unit300inFIG. 6is not held in receiving recess80, first vent section50is not sealed. Sliding element330of fanless power supply unit300is designed to engage in tool housing90through second vent section40when fanless power supply unit300is inserted into receiving recess80and to thereby move externally operated change-over gate20out of its depicted second switch position20N.

FIG. 7now shows how sliding element330acts on externally operated change-over gate20. By moving further along in the direction of the arrow, externally operated change-over gate20is slid toward first vent section50to ultimately seal it, as depicted inFIG. 8.

InFIG. 8, fanless power supply unit300is now completely held in receiving recess80. The sealing element designed as a sliding element330has switched over externally operated change-over gate20entirely into a first switch position20A, so that first vent section50is completely sealed and second vent section40is completely open. A volume flow V aspirated by cooling fan60can now flow through rear vent312of power supply unit300into inner ventilation channel310of fanless power supply unit300to cool the latter. Subsequently, volume flow V flows through front vent311and second vent section40aligned with it into tool housing90. As long as fanless power supply unit300is arranged in receiving recess80, the sealing element designed as sliding element330will retain externally operated change-over gate20in first switch position20A depicted inFIG. 8.

LIST OF REFERENCE SIGNS