GB2505321A

GB2505321A - A spraying device for a portable power tool

Info

Publication number: GB2505321A
Application number: GB1314835.8A
Authority: GB
Inventors: Endre Zador; Krisztian Sepsi
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2012-08-20
Filing date: 2013-08-19
Publication date: 2014-02-26
Anticipated expiration: 2033-08-19
Also published as: CN103621378A; GB201314835D0; DE102012214712A1; CN103621378B; GB2505321B; DE202012013680U1

Abstract

A spraying device 10 for a portable power tool 12 comprises a holding tank 14 for a fluid, a connecting unit 18 that includes a drive connecting element 20, and a pump unit (16, Fig 2). The pump unit (16, Fig 2) conveys fluid from the holding tank 14 and is coupled to an output element 22 of the power tool by the connecting element 20 so as to effect driving. The drive connecting element 20 may be a form-fit coupling which is connected to a fluid conveying element (26, Fig 2) of the pump unit (16, Fig 2). The device may comprise latching mean 34, 36, 38, 40 for attachment to a power tool and a coding element 44 for actuating a switch 46 on a power tool. A locking element 50 may prevent opening of a closure element 52 of the tank 14. Pump unit (16, Fig 2) may comprise an overpressure safety unit (54, Fig 2) and a prefilling unit (56, Fig 3). The pump unit (16, Fig 2) may be disposed in the holding tank 14. The device may be a garden-appliance spraying device.

Description

Spraying device*

Prior art

There are already known spraying devices for portable power tools, which have a medium holding tank, and have a pump unit for conveying a medium present in the medium holding 10. tank, in at least one state.

Disclosure of the invention -

The invention is based on a spraying device, in particular on a garden-appliance sprayiDg device, for a portable power tool, having at least one medium holding tank, and having at least one pump unit for conveying a medium present in the medium holding tank, in at least one state, in particular when the pump unit is in a driven state.

It is proposed that the spraying device have at least one connecting unit that, for the purpose of driving the pump unit, comprises at least one drive connecting element for coupling the pump unit to an output element of an output unit of the portable power tool so as to effect driving.

Particularly preferably, the spraying device is realized separately from an electrical drive unit for driving the pump unit. For the purpose of driving the pump unit, therefore, the spraying device, preferably when disposed on the portable power tool, uses a drive unit of the portable power tool that is connected to the output unit. The output element in this case cab be realized as an output spindle, as an output gearwheel, an output form-fit coupling element, etc. It is also conceivable, however, for the output element to be constituted by an output element disposed on an armature shaft of the drive unit.

The output unit can be realized as a transmission that is separate from the drive unit, or as a sub-assembly of the drive unit. The spraying device can preferably be used for wetting and/or watering plants or the like with a medium, in particular with water and/or with a fertilizer dissolved in water, etc. It is also conceivable, however, for the spraying device to be used for distributing paint on a workpiece. Further application possibilities, considered appropriate by persons skilled in the art, are likewise conceivable.

The term "medium holding tank" is intended here to define, in particular, a container for storing, transporting or holding a medium, in particular a liquid such as, in particular, water, the container being realized, in particular, so as to be liquid-tight. Particularly preferably, the medium holding tank is delimited by housing walls of a housing of the spraying device. The medium holding tank thereby preferably delimits a medium holding volume for storing and/or holding a medium, in particular water or a fertilizer dissolved in water, etc. A "pump unit" is to be understood here to mean, in particular, a unit, in particular a machine, provided to convey media, in particular liquids (non-compressible fluids) , by conversion of driving work into energy of motion. "Provided" is to be understood to mean, in particular, specially programmed, configured and/or designed. Preferably, the pump unit is realized as a positive-displacement pump unit. In this case, particularly preferably, the pump unit is realized as a gear pump, in particular as an internal gear pump. It is -a -also conceivable, however, for the rump unit to be of.

another design, considered appropriate by persons skilled in the art, such as, for example, being designed as a flow pump unit. The expression T!coflnecting unit" is intended here to define, in particular, a unit by means of which a housing of the spraying device can be fastened to a tool receiver of a portable power tool in a form-fitting and/or force-fitting manner. The housing of the spraying device preferably encloses at least the pump unit and the medium holding tank. "Coupling so as to effect driving" is intended here to define, in particular, connection of the drive connecting element to an output element such as, for example, a spindle, etc. of the portable power tool, for the purpose of transmitting drive forces of a drive unit of the portable power tool. The design of the spraying device according to the invention makes it possible, advantageously, to realize a compact spraying device that, in particular, is realized separately from the electrical drive unit. Advantageously, therefore, it is possible to realize savings of components and, advantageously, a low-weight spraying device can be achieved. In addition, advantageously, a portable power tool can be used to drive the pump unit, such that a high degree of application flexibility can be achieved.

Furthermore, it is proposedthat the drive connecting element be realized a.s a form-fit coupling element, which is connected to at least one medium conveying element of the pump unit. It is also conceivable, however, for the drive connecting element to be of another design, considered appropriate by petsons skilled in the art, such as, for example, being designed as a force-fit coupling element. Particularly preferably, the drive connecting element comprises at least one continuation and/or at least one recess, which continuation and/or recess can be connected in a form-fitting manner to an output element of an output unit of the portable power tool, which output element is realized to correspond to the drive connecting element. The output element therefore preferably comprises recesses and/or continuations that correspond to the continuation and/or the recess of the drive connecting element. The design accotding to the invention enables a connection to a drive of the pump unit to be realized by simple design means.

Further, it is proposed that, for the purpose of connection to at least the medium conveying element of the pump unit, the drive connecting element have at least one form-fit region, which is connected to the medium conveying element.

Particularly preferably, the firm-fit region of the drive connecting element engages in the medium conveying element.

The medium conveying element is preferably realized as a gearwheel or as an impeller. It is also conceivable, however, for the medium conveying element to be of another design, considered appropriate by persons skilled in the art, such as, for example, being designed as a membrane element, etc. The design according to the invention.

advantageously enables a secure connection to be realized, for reliable driving of the pump unit. IP addition, advantageously, a rotationally fixed connection to a drive of the pump unit can be achieved. . In addition, it is proposed that the spraying device comprise at least one -housing, disposed on which there is at least one latching element of the donnecting unit, for connection to a tool receiver of the portable power tool in 4. .. I -* a. form-fitting and/or force-flttihg manner. The latching element is preferably realized as a latching recess, in which at least *one counter-latching element of a fixing unit of the portable power tool engages, in at least one state, which counter-latching element is realized as a latching hook. It is also conceivable, however, for the latching element tc be of another design, considered appropriate by persons skilled in the art, such as, for example, being designed as a latching hook.

Advantageously, secure fastening of the spraying device to.

the pbrtable power tool can be realized.

Furthermore, it is proposed that the connecting unit comprise at least one coding element, which is provided to actuate a switch element of the portable power tool, in at least one state. The coding element is preferably realized as a pin or stud. The coding element in this case, preferably when disposed on the portable power tool, actuates a. micro-switch of the portable power tool that, via an electronics unit of the portable power tool, switches over the portable power tool to an operating mode suitable for driving the pump. In this case, a rotational speed, a direction of rotation of the output element and/or further characteristic values of the portable power tool are adapted to operation of the pump unit. Advantageously, overload and/or incorrect mountin of the spraying device can be avoided.

Furthermore, it is proposed that the spraying device have at least one locking unit, comprising at least one locking element that prevents opening of a closure element of the medium holding tank, in at least one state. The locking unit in this case is realized, in particular, as a form-fit locking unit, which, by means of a form-fit connection, when the housing is disposed on the portable power tool, prevents opening of the closure of the medium holding tank, by means of a combined action of the locking' element, realized as an edge region of the closure element. Thus, advantageously, opening of the closure element of the medium holding tank can be prevented when the housing is disposed on the portable power tool. This advantageously prevents electronic components of the portable power tool frcm becoming wet.

In addition, it is proposed that the pump unit comprise at least one overpressure safety unit, which is provided to be moved into a discharge position as a result of a critical pressure in the pump unit. Preferably, the overpressure safety unit comprises at least one overpressure valve, unit, which opens when a critical pressure is attained in the pump unit. The overpressure valve unit in this case can be operated mechanically and/or operated electrically. A * 20 "critical pressure" is to be understood here to mean, in particular, a pressure inside the pump unit that would result in damage to the pump unit. Advantageously, therefore, the design accordihg to the invention makes it possible to prevent damage to the pump unit resulting from * 25' a critical pressure inside the pump unit.

Furthermore, it is proposed that the pump unit have at least one prefilling unit that, in at least one state, enables a medium to flow into the pump unit, before the pump unit is put into operation. The design according to the invention advantageously makes it possible for wear on the pump unit, in the case of "dry starting", tobe kept to a lowlevel. In addition, advantageously, the pump unit can be made to operate at full capacity from the start.

Further, it is proposed that the pump unit be disposed in the medium holding tank. In this case, a housing of the pump unit is disposed inside the medium holding tank: In particular, more than 80%, preferably more than 85%, and particularly preferably more than 90% of all components of the pump unit are disposed inside the medium holding tank.

Advantageously, therefore, a compact spraying device dan be achieved.

In addition, the invention is based on a power tool system having at least one portable power tool and having at least one spraying device according to the invention. A "portablepower tool" is to be understood here to mean, in particular, a power tool for performing work on workpieces and/or plants, in particular garden plants, which power tbol can be transported by an operator without the use of a transport machine. The portable power tool has, in particular, a mass of less than 40 kg, preferably less than kg, and particularly preferably less than 5 kg.

Particularly preferably, the portable power tool is realized as a garden appliance that can be operated electrically. It is also conceivable, however, for the portable power tool to be of another design, considered appropriate by persons skilled in the art, such as, for example, being de.signed as a nultifunction power tool, as a drill, etc. Advantageously, the design according to the invention enables a high degree of operating comfort to be achieved. In addition, a wide range of application can be achieved for the portable power tool.

*The spraying device adcording to the invention, and/or the: power tool system according to the invention, in this case are/is not intended to be limited to the application and embodiment described above. In particular, the spraying device according to the invention and/or the power tool system according to the invention, for the purpose of implementing a mode of functioning described herein, can have a number of individual elements, components and units that differs from a number stated herein.

* Drawing 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.

In the drawing: Fig. 1 shows a power tool system according to the invention, having a portable power tool according to the invention, and having a spraying device according to the invention, in a schematic representation, Fig. 2 shows a detail view of the spraying device according to the invention, in a schematic representation, * Fig. 3 shows a detail view of a pump unit of the spraying device according to the invention, in a schematic representation, * + Fig.4 shows a detail viewof an overpressure Eafety unit of the spraying device according to the invention, in a schematic representation, Fig. 5 shows a detail view of a prefilling unit of the spraying device according to the invention, in a schematic representation, and Fig. 6 shows a detail view of the prefilling unit of the spraying device according to the invention, in a schematic representation. -

Description of' the exemplary embodiment

Figure shows a power tool system 60 having at least one portabld power tool 12 and having at least one spraying device 0. The portable power tool 12 is realized as a garden ppliance that can be operated electrically. In this case-, the portable power tool 12 has a power tool housing 62. The powertool housing 62 encloses a drive unit 64 nd an output unit 24 of the portable power tool 12. The drive unit 64 is realized as an erectric motor unit. T'he output unit 24 is realized as a transmission unit, wh1ich is provided to gear-up arid/or gear-down a drive torque and/or a drive rotational speed of the drive unit 64. It is also conceivable, however, for the portable power tol 12 to be realized separately from the output unit 24, or for the output unit 24 to transmit a drive torque ahd/or a drive rotational speed of the drive unit 64 without gearing-up and/or gearing-down. The output unit 24 compriseà at least one output spindle 66, and an output element 2 disposed in a rotationally fixed manner on the output sind1e 66. The output element 22 is realized as a form-fit coupling element. In this case, the output element 22 comprises continuations, which extend at least -10 ± substantially parallelwise in relation to a rotation axis of the output spindle 66.

The spraying device 10 for the portable power tool 12 has at least one medium holding tank 14, and at least one pump unit 16 for conveying a medium present in the medium holding tank 14, in at least one state. Moreover, the spraying device 10 has at least one connecting unit 18, which, for the purpose of driving the pump unit 16, comprises at least one drive connecting element 20 for coupling the pump unit 16 to the output element 22 of the output unit 24 of the portable power tool 12 so as to effect driving. When a housing 32 of the spraying device is disposed on a tool receiver 42 of the portable power tool 12, therefore, the pump unit 16 is driven by means of the drive connecting element 20. In addition, the spraying device 10, or the housing 32 of the spraying device 10, can be fastened to the portable power tool 12 by means of the connecting unit 18. For this purpose, the spraying device lOcomprises at least the housing 32, on which there is disposed at least one latching element 34, 36, 38, 40 of the connecting unit 18, for connection to the tool receiver 42 cf the portable power tool 12 in a form-fitting and/or force-fitting manner. In total, the connecting unit 18 has four latching elements 34, 36, 38, 40 disposed on the housing 32. It is also conceivable, however, for the connecting unit 18 to have a number of latching elements 34, 36, 38, 40 other than four. The latching elements 34, 36, 38, 40 are realized as latching recesses, which act in combination with counter-latching elements 68, 70 of a fixing unit 72 of the portable power tool 12 (in Figure 1, only two counter-latching elements 68, 70 are represented) for the purpose of fastening the housing 32 to the tool

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receiver 42. The bounter-latching elements 68, 70 are realized as spring-biased latching hooks, which engage in the latching elements 34, 36, 38, 40 realized as latching recesses, when the housing 32 is disposed on the. tool receiver 42. For the purpose of undoing a connection of the latching elements 34, 36, 38, 40 and the counter-latching elements. 68, 70, the fixing unit 72 comprises an operating element 74. The spring-biased counter-latching elements 68, 70 can thereby he moved out of the latching elements 34, 36, 38, 40 realized as latching recesses, contrary to a spring force, in a manner already known to persons skilled in the art.

The drive connecting element 20 is realized as a form-fit coupling element, which is connected to at least one medium conveying element 26 of the pump unit 16 (Figure 2) . In this case, the drive connecting element 20 is realized so as to correspond to the output element 22. The drive connecting element 20 comprises gable-roof type connecting teeth that, when the housing 32 is disposed on the portable power tool 12, engage in recesses of the output element 22 that are realized so as to correspond to the connecting teeth of the drive connecting element 20. When the housing 32 is disposed on the tool receiver 42, and fixed to the tool receiver 42 by means of the connecting unit 18, the output element 22 is connected to the drive connecting element 20 in a form-fitting manner along a direction of rotation of the output element 22. Therefore, when the housing 32 is disposed on the tool receiver 42, and fixed to the tool receiver 42 by means of the connecting unit 18, the output element 22 and the drive connecting element 20 are connected to each other in a rotationally fixed manner.

-12 -Further, for the purpose of connection to at least the medium conveying element 26 of the pump unit 16,. the drive oonnecting element 20 has at least one fotm-fit region 30, which is connected to the medium conveying element 26. The form-fit region 30 is realized as a toothed shaft region of the drive connecting element 20. The medium conveying element 26 is realized as a gearwheel. The pump unit 16 is thus realized as a gear pump unit. The form-fit region 30 in this case engages in an inner toothing of the medium conveying element 26 that is realized so as to correspond to the form-fit region 30 (Figure 2). The pump unit 16has a further medium conveying element 28, which acts in combination with the medium conveying element 26 for the purpose of conveying a medium. The further medium conveying element 28 is likewise realizedas a gearwheel.

By means of driving of the medium conveying element 26, when the drive connecting element 20 is connected to the output element 22, the further medium conveying element 28 is driven as a result of engagement of teeth of the medium conveying element 26 and of the further medium conveying element 28. A medium is thereby conveyed as a result of displacement, or is compressed in a pressure region 58 in a manner already known to persons skilled in the art (Figures 2 and 3) . The pump unit 16 additionally has a suction intake region 76. The suction intake region 76 is connected to the medium holding tank 14., by means of a suction intake line 78 of the pump unit 16, so as to effect flow. The pressure region 58 of the pump unit 16 is connected to a spraying head 82 of the spraying device 10, by means. of a pressure line 80, for the purpose of spraying a medium present in the medium holding tank 14. The spraying head 82 in this case is of a design, already known to persons skilled in the art, for atomizing medium and/or

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for spraying medium in the form of a jet. The spraying head 82 in this case is disposed on an outer wall of the housing 32, at least one channel of the spraying head 82 extendihg in the direction of the medium holding tank 14.

and being connected to the pressure line 80. The pressure region 8, as viewed along a direction of flow of a medium inside he pump unit 16, is preferably disposed on a side that fa?es away from the suction intake region 76 of the pump unit 16.

The pump unit lGis disposed in the medium holding tank 14 (Figure'2). In this case, a pump housing 84 that carries the medium conveying element 26 and the further medium conveying element 28 is disposed inside the medium holding tank 14J The suction intake line 78 and the pressure line likewise go through the medium holding tank 14. The suctionintake line 78 in this case is connected, by one end, to ithe suction intake region 76 of the pump unit 16 and, by a further end, the suction intake line 78 i_s connected to a suction intake connection piece 86 integrally formed on to an inner wall of the housing 32.

The pressure line 80 is connected, by one end, to the pressur region 58 and, by a further end, the pressure line is cdnnected tc the spraying head 82. The suction intake line 78 and the pressure line 80 are each realized as a hose, In this case, the suction intake line 78 -and the pressure line 80 are each realized as a rubber hose.

It is aiiso conceivable, however, for the the suction intake line 78 and the pressure line 80 each to be integrally..

formed o to an inner wall of the housing 32 of the spraying device 10 that delimits the medium holding tank 14.

-4 -. -- -14 -Furthermore, the connecting unit 18 comprises at least one coding element 44, which is provided to actuate a switch element 46 of the portable power tool 12, in at least one state. The coding element 44 is realized as a coding pin, which is disposed on a side of the housing 32 that faces away from the spraying head 82 of the spraying device 10.

The coding element 44 in this case is disposed in a connection region of the housing 32. When the housing 32 is disposed on the portable power tool 12, the coding element 44 actuates the switch element 46 disposed in the region of the tool receiver 42. The switch element 46 is realized as a microswitch. As a result of an actuation of the switch element 46, the portable power tool 12 is switched to a spraying-device operating mode, by means of an electronic unit (not represented in greater detail here) of the portable power tool 12. In this case, a direction 61 rotation, a rotational speed and further characteristic values cf the portable power tool 12, considered appropriate by persons skilled in the art, are set by means of the output element 22.

The spraying device 10 additionally comprises at least one locking unit 48, which comprises at least one locking element 50 that, *in at least one state, prevents opening of -a closure element 52 of the medium holding tank 14. The locking element 50 is realized as a flattened edge region of the closure element 52. It is also conceivable, however, for the locking element 50 to be of another design, considered appropriate by persons skilled in the art, such as, for example, being designed as a 1cc-king hoop, as a locking latching element, etc., by means of which opening of the closure element 52 of the medium holding tank 14 can be prevented, at least in one state.

-15 -For the purpose of preventing opening of the closure element 52, when the housing 32 is disposed on the portable power tool 12, the locking element 50 abts in combination with a form-fit element 88 of the portable power tool 12.

The form-fit element 88 is disposed in the region of the tool receiver 42. The form-fit element 88 in this case is realized as a web that delimits a connecting region of the portable power tool 12.

The pump unit 16 furthermore comprises at least one overpressure safety unit 54, which is provided to be moved into a discharge position (Figures 2 and 4) as a result of a critical pressure in the pump unit 16. The overpressure safety unit 54 is realized as an overpressure valve unit.

The overpressure safety unit 54 in this case comprises at least one sealing element 90, a spring element 92 and a movably mounted valve element 94. The sealing element 90 is realized as an 0-ring, which is disposed in a groove on the valve element 94. The valve element 94 is movably mounted on a guide continuation 96 of the pump housing 84.

In this case, the region between the valve element 94 and the guide continuation 96 is sealed off by means of a further sealing element (not represented in greater detail -here) of the overpressure safety unit 54. The spring element 92 is supported, by one end, on the valve element 94 and, by a further end, the spring element 92 is supported on a disc element 98 fastened to the guide continuation 96. The overpressure safety unit 54 is disposed in the pressure region 58 of the pump unit 16.

Upon attainment of a critical pressure, the valve element 94 is moved, by a medium compressed by means of the pump unit 16, contrary to a spring force of the spring element 92. As a result of this, a channel is opened between the -16 -pressure region 58 and the medium holding tank 14, and the medium can flow out of the pressure region 58 and back into the medium holding tank 14. This results in a drop in pressure inside the pressute region 58 of the pUmp unit 16.

S

The pump unit 16 additionally has at least one prefilling unit 56, which, in at least one state enables a medium to flow into the pump unit 16, before the pump unit 16 is put into operation (Figures 5 and6). The prefilling unit 58 in this case comprises at least one prefilling sealing element 100, a prefilling spring element 102 and a prefilling valve element 1Q4. The prefilling unit 56 in this case is provided to allow air to escape from the pump unit 16 and/or from the medium holding tank 14, in at least one state, to enable medium to flow into the pump unit 16 before the pump unit 16 is put into operation, in at least one state. The prefilling unit 56 is disposed in the connecting region of the housing 32. Consequently, as a result of the housing 32 being disposed on the portable power tool 12, the prefi.lling valve element 104. is moved contrary to a spring force of the prefilling spring element 102. As a result of this, an air opening is closed by means of the prefilling sealing element 100 disposed on the prefillingspring element 102. Inside the. pump unit 16, therefore, a pressure for conveying a medium present in the medium holding tank 14 can be generated inside the pump unit 16, after the housing 32 has been disposed on the portable power tool 12 and as a result of driving of the pump unit 16 by connection of the drive connecting element 20 and the output element 22.