SE2150298A1

SE2150298A1 - A robotic lawnmower with water spray nozzles

Info

Publication number: SE2150298A1
Application number: SE2150298A
Authority: SE
Inventors: Christian Knecht
Original assignee: Husqvarna Ab
Priority date: 2021-03-17
Filing date: 2021-03-17
Publication date: 2022-09-18
Also published as: DE102022104750A1

Abstract

The present disclosure relates to a robotic lawnmower (100) comprising a main body part (140), a plurality of wheels (130), a control unit (110) and at least one electric motor (150. At least one wheel (130) is drivably connected to at least one electric motor (150), and the robotic lawnmower (100) further comprises a grass cutting device in the form of a rotatable disc (160) that is driven by a cutter motor (165). The robotic lawnmower (100) comprises a water inlet (119), at least two water spray nozzles (120a, 120b, 120c, 120d, 120e; 121a, 121b, 121c, 121d, 121e) and a water channel arrangement (122, 123) that is adapted to distribute water from the water inlet (119) to the water spray nozzles (120a, 120b, 120c, 120d, 120e; 121a, 121b, 121c, 121 d, 121 e). At least one water spray nozzles (120a, 120b, 120c, 120d, 120e; 121a, 121 b, 121c, 121d, 121e) is adapted to distribute water in a direction away from the rotatable disc (160).

Description

The present disclosure relates to a robotic Iawnmower comprising a main body part, a plurality of wheels, a control unit and at least one electric motor, where at least one wheel is drivably connected to at least one electric motor. The robotic Iawnmower further comprises a grass cutting device in the form of a rotatable disc that is driven by a cutter motor.

BACKGROUND Robotic work tools such as for example robotic lawnmowers are becoming increasingly more popular. ln a typical deployment a work area, such as a garden, the work area is enclosed by a boundary wire with the purpose of keeping the robotic Iawnmower inside the work area. An electric control signal may be transmitted through the boundary wire thereby generating an (electro-) magnetic field emanating from the boundary wire. The robotic Iawnmower is typically arranged with one or more sensors adapted to sense the control signal.

Alternatively, or as a supplement, the robotic Iawnmower can be equipped with a navigation system that is adapted for satellite navigation as well as navigation by means of a local base station.

The robotic Iawnmower is adapted to cut grass on a user's lawn automatically and can be charged automatically without intervention of the user, and does not need to be manually managed after being set once.

The robotic Iawnmower comprises a cutting device that is housed within a body, where the robotic Iawnmower comprises an underneath that is open towards the ground during operations such that the cutting device can reach the grass to be cut. A semi- enclosed space is thus formed within which the cutting device is comprised. During cutting, the robotic Iawnmower may attract pieces of cut grass and other debris that may accumulate within the semi-enclosed space, both at inner walls and at parts associated with the cutting device. Especially under wet conditions, this builds up around the wheels and other parts of the robotic lawnmower. lt is desirable to remove most such accumulated debris, and normally this is done by a user spraying the underside of the lower side of the robotic lawnmower with a garden hose. lt is a lot of manual work for the user to lift/turn the mower and clean it. This may also result in uncontrolled spraying where loosened debris may be displaced in an uncontrolled manner and for example end up on the user. lt is therefore desired to provide means for uncomplicated and quickly managed cleaning of a robotic lawnmower where debris is loosened in a controlled manner.

SUMMARY The object of the present disclosure is to provide means for uncomplicated and quickly managed cleaning of a robotic lawnmower where debris is loosened in a controlled manner.

This object is achieved by means of robotic lawnmower comprising a main body part, a plurality of wheels, a control unit and at least one electric motor, where at least one wheel is drivably connected to at least one electric motor. The robotic lawnmower further comprises a grass cutting device in the form of a rotatable disc that is driven by a cutter motor. The robotic lawnmower comprises a water inlet, at least two water spray nozzles and a water channel arrangement that is adapted to distribute water from the water inlet to the water spray nozzles. At least one water spray nozzle is adapted to distribute water in a direction away from the rotatable disc.

This means that a user is relieved of the manual work of lifting/turning the robotic mower for cleaning, and that uncontrolled spraying, where loosened debris may be displaced in an uncontrolled manner and for example end up on the user, is prevented.

Since at least some of the water is distributed in other directions than towards the rotatable disc, the rotatable disc is not needed for distributing water for cleaning the underneath and for cleaning the wheels, and the rotatable disc does not have to be moving during cleaning. This way, the robotic lawnmower can be tilted during cleaning in order to facilitate that water and debris flows off the underneath without risk of injury from the rotatable disc, since the rotatable disc does not need to rotate but can be motionless.

According to some aspects, the rotatable disc comprises pivoting knives.

According to some aspects, the robotic Iawnmower comprises an underneath that comprises inner walls and is adapted to mainly face the ground when the robotic Iawnmower is running. The water spray nozzles are provided in the underneath and are adapted to provide a distribution of water in the underneath.

This means the robotic Iawnmower can be cleaned in its normal working position, the underneath facing the ground.

According to some aspects, at least one water spray nozzle is adapted to distribute water in a direction at an angle relative a plane that is parallel to an ideal horizontal ground level during normal running, where the angle differs from zero.

This way, the directions in which water is distributed can be chosen such that areas where debris normally builds up are subject to a sufficient stream of distributed water.

According to some aspects, the water inlet is adapted to be connected to a water source, such as a garden hose. According to some further aspects, the water inlet is of such a type that it admits connection of a standard garden hose connector attached to the water source.

This way, a quick and uncomplicated connection to a water source is enabled.

According to some aspects, the water channel arrangement and/or the water spray nozzles are separate parts that are mounted to the main body part and/or to a chassis of the robotic Iawnmower. Alternatively, the water channel arrangement and/or the water spray nozzles are integrated into the design of the main body part and/or the chassis of the robotic Iawnmower.

This means that the water channel arrangement and/or the water spray nozzles can be formed in different ways, and either be added to an existing design, or be integrated into a new design.

According to some aspects, the water channel arrangement may be constituted by one or more channel branches, each channel branch comprising one or more water spray nozzles.

This way, the water channel arrangement can be designed in the most favorable manner for a certain robotic lawnmower design.

BRIEF DESCRIPTION OF THE DRAWINGS The present disclosure will now be described more in detail with reference to the appended drawings, where: Figure 1A shows a perspective side view of a robotic lawnmower; Figure 1B shows a schematic overview of the robotic lawnmower; Figure 2 schematically illustrates a perspective bottom view of the robotic lawnmower; and Figure 3 schematically illustrates a side view of the robotic lawnmower.

DETAILED DESCRIPTION Aspects of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings. The different devices, systems, computer programs and methods disclosed herein can, however, be realized in many different forms and should not be construed as being limited to the aspects set forth herein. Like numbers in the drawings refer to like elements throughout.

The terminology used herein is for describing aspects of the disclosure only and is not intended to limit the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

Figure 1A shows a perspective view of a robotic lawnmower 100 and Figure 1B shows a schematic overview of the robotic lawnmower 100. The robotic lawnmower 100 is adapted for a forward trave||ing direction D, has a body 140 and a p|ura|ity of wheels 130; in this example the robotic lawnmower 100 has four wheels 130, two front wheels and two rear wheels. The robotic lawnmower 100 comprises a control unit 110 and at least one electric motor 150, where at least some of the wheels 130 are drivably connected to at least one electric motor 150. lt should be noted that even if the description herein is focused on electric motors, combustion engines may alternatively be used in combination with an electric motor arrangement. The robotic lawnmower 100 may be a multi-chassis type or a mono-chassis type. A multi-chassis type comprises more than one body parts that are movable with respect to one another. A mono-chassis type comprises only one main body part. ln this example embodiment, the robotic lawnmower 100 is of a mono-chassis type, having a main body part 140. The main body part 140 substantially houses all components of the robotic lawnmower 100. The robotic lawnmower 100 comprises an underneath 193 that comprises inner walls 190, 191, and is adapted to mainly face the ground when the roboticlawnmower100 is running. An aperture 192 of the underneath 193 is adapted to face the ground when the robotic lawnmower 100 is running. The wheels 130 extend from the underneath 193 towards the ground when the robotic lawnmower 100 is running. ln this context, the term running means normal running of the robotic lawnmower 100 on the ground, in Figure 3 indicated with an ideal horizontal ground level 180. ln reality, the ground of course normally follows a more or less changing form with different inclinations.

The robotic lawnmower 100 also comprises a grass cutting device in the form of a rotatable disc 160 that is driven by a cutter motor 165. According to some aspects, the rotatable disc 160 comprises pivoting knives 161, 162, 163, the pivoting knives 161, 162, 163 for example being in the form of a p|ura|ity of separate rotating blades 161, 162, 163. The grass cutting device 160 is positioned in the underneath 193 and is adapted to reach the grass to be cut via the aperture 192.

The robotic Iawnmower 100 also has at least one rechargeable electric power source such as a battery 155 for providing power to the electric motor arrangement 150 and/or the cutter motor 165. Such a battery can be charged via charging skids 156 at a charging station in a well-known manner.

According to some aspects, the robotic lawnmower 100 may further comprise at least one navigation sensor arrangement 175 and/or at least one environment detection device 170 such as a radar transceiver, a Lidar transceiver, an ultrasonic transceiver and/or a camera device.

The robotic lawnmower 100 comprises a water inlet 119, at least two water spray nozzles 120a, 120b, 120c, 120d, 120e; 121a, 121b, 121c, 121d, 121e and a water channel arrangement 122, 123 that is adapted to distribute water from the water inlet 119 to the water spray nozzles120a,120b,120c,120d,120e;121a,121b,121c,121d, 121e. According to some aspects, the water inlet 119 is adapted to be connected to a water source, such as a garden hose 124. The water inlet can be of such a type that it admits connection of a standard garden hose connector 125 attached to the garden hose 124.

According to the present disclosure, at least one water spray nozzles 120a, 120b, 120c, 120d, 120e; 121a, 121b, 121c, 121d, 121e is adapted to distribute water in a direction away from the rotatable disc 160.

According to some aspects, the water spray nozzles 120a, 120b, 120c, 120d, 120e; 121a, 121b, 121c, 121d, 121e are provided in the underneath 193 and are adapted to provide a distribution of water in the underneath 193, where the distributed water enables an efficient cleaning of items in the underneath 193, for example of exposed parts of the inner walls 190, 191. The distributed water also enables an efficient cleaning of items that can be at least partly outside the underneath 193, such as parts of the wheels 130 that are exposed to the distributed water.

This means the robotic Iawnmower 100 can be cleaned in its normal working position, the aperture 192 facing the ground. This results in that a user is relieved of the manual work of lifting/turning the robotic mower for Cleaning, and that uncontrolled spraying, where Ioosened debris may be displaced in an uncontrolled manner and for example end up on the user, is prevented.

Since at least some of the water is distributed in other directions than towards the rotatable disc 160, the rotatable disc 160 is not needed for distributing water for cleaning the underneath 193 and for cleaning the wheels 130, and the rotatable disc 160 does not have to be moving during cleaning. This means that the robotic lawnmower 100 can be tilted during cleaning in order to facilitate that water and debris flows off the underneath 193 without risk of injury from the rotatable disc 160, since the rotatable disc 160 does not need to rotate but can be motionless. The rotatable disc 160 is in this example shown to comprise pivoting knives 161, 162, 163, but other cutting means are of course conceivable.

Each water spray nozzle120a,120b,120c,120d,120e;121a,121b,121c,121d,121e can be adapted to distribute water in one or more directions. According to some aspects, as indicated in Figure 2 with arrows A1, A2, A3, A4 (only a few indicated for reasons of clarity), each water spray nozzle120a, 120b, 120c, 120d, 120e; 121 a, 121 b, 121c, 121d, 121e can be adapted to distribute water in four different directions. According to some aspects, these directions can differ from water spray nozzle to water spray nozzle, and can be directed at different angles in a plane P that is parallel to an ideal horizontal ground level during normal running, and at different angles relative the plane P.

According to some aspects, as illustrated for a first water spray nozzle 120a in Figure 3, at least one water spray nozzle 120a is adapted to distribute water in a direction A1 at an angle ß relative the plane P that is parallel to an ideal horizontal ground level 180 during normal running, where the angle ß differs from zero. The directions in which water is distributed should according to some aspects be chosen such that areas where debris normally builds up are subject to a sufficient stream of distributed water.

Each stream of distributed water can have a certain suitable composition such as for example jet or mist depending on the intended target area. This is enabled by a certain design of the water spray nozzles 120a, 120b, 120c, 120d, 120e; 121a, 121b, 121c, 121d, 121e, which furthermore are designed to utilize normal water pressure.

The water channel arrangement 122, 123 is in this example illustrated as having a first channel branch 122 and a second channel branch 123, where the first channel branch 122 is connected to five water spray nozzles 120a, 120b, 120c, 120d, 120e, and where the second channel branch 123 is connected to five other water spray nozzles 121a, 121b, 121c, 121d, 121e. Each channel branch 122, 123 is constituted by a water channel that is adapted to route supplied water to the corresponding water spray nozzle120a,120b,120c,120d,120e;121a,121b,121c,121d,121e.

The present disclosure is not limited to the examples provided above, but may vary within the scope of the appended claims. For example, the water channel arrangement 122, 123 and/or the water spray nozzles 120a, 120b, 120c, 120d, 120e; 121a, 121b, 121c, 121d, 121e can be separate parts that are mounted to the main body part 140 and/or to a chassis 194 (only schematically indicted in Figure 2) of the robotic lawnmower 100. The water channel arrangement 122, 123 can for example by mounted by means of snap-fit.

The water channel arrangement 122, 123 and/or the water spray nozzles 120a, 120b, 120c,120d,120e;121a,121b,121c,121d,121e can also be more or less integrated into the design of the main body part 140 and/or the chassis 194 of the robotic lawnmower 200.

According to some aspects, the water channel arrangement 122, 123 can run on either side of an inner wall 190, or on both sides of an inner wall 190.

The water channel arrangement may be constituted by one or more channel branches, each channel branch comprising one or more water spray nozzles.

According to some aspects, the water channel arrangement 122, 123 and the water spray nozzles120a,120b,120c,120d,120e;121a,121b,121c,121d,121e constitute a robotic lawnmower cleaning arrangement.

With reference to Figure 2 and Figure 3, the underneath 193 comprises a first inner wall 190 that is not a part of the main body part 140, and a second inner wall 191 that is comprised in the main body part 140. These inner wall 190, 191 can have other forms and extension, and the underneath 193 can comprise further inner walls that for example cover components of the robotic Iawnmower 100. The underneath 193 can according to some aspects be regarded as a semi-enclosed inner space. The underneath 193 can according to some aspects comprise one or more other items, such as for example chassis parts.

The aperture 192 can have different shapes, and can, as shown in Figure 3, for example follow the shape of wheel housings in the main body part 140.

Claims

1. A robotic Iawnmower (100) comprising a main body part (140), a plurality of wheels (130), a control unit (110) and at least one electric motor (150), where at least one wheel (130) is drivably connected to at least one electric motor (150), where the robotic Iawnmower (100) further comprises a grass cutting device in the form of a rotatable disc (160) that is driven by a cutter motor (165), where the robotic Iawnmower (100) comprises a water inlet (119), at least two water spray nozzles (120a, 120b, 120c, 120d, 120e; 121a, 121b, 121c, 121d, 121e) and a water channel arrangement (122, 123) that is adapted to distribute water from the water inlet (119) to the water spray nozzles (120a, 120b,120c,120d, 120e;121a,121b, 121c, 121d,121e),wherein at least one water spray nozzle (120a, 120b, 120c, 120d, 120e; 121a, 121b, 121c, 121d, 121e) is adapted to distribute water in a direction away from the rotatable disc (160).

2. The robotic Iawnmower (100) according to claim 1, wherein the rotatable disc (160) comprises pivoting knives (161, 162, 163).

3. The robotic Iawnmower (100) according to any one of the claims 1 or 2, wherein the robotic Iawnmower (100) comprises an underneath (193) that comprises inner walls (190, 191) and is adapted to mainly face the ground when the robotic Iawnmower (100) is running, where the water spray nozzles (120a, 120b, 120c, 120d, 120e; 121a, 121b, 121c, 121d, 121e) are provided in the underneath (193) and are adapted to provide a distribution of water in the underneath (193).

4. The robotic Iawnmower (100) according to any one of the previous claims, wherein at least one water spray nozzle (120a) is adapted to distribute water in a direction (A1) at an angle (ß) relative a plane (P) that is parallel to an ideal horizontal ground level (180) during normal running, where the angle (ß) differs from zero.

5. The robotic Iawnmower (100) according to any one of the previous claims, wherein the water inlet (119) is adapted to be connected to a water source (124), such as a garden hose (124).

6. The robotic Iawnmower (100) according to claim 5, wherein the water inlet (119) is of such a type that it admits connection of a standard garden hose connector (125) attached to the water source (124).

7. The robotic Iawnmower (100) according to any one of the previous claims, wherein the water channel arrangement (122, 123) and/or the water spray nozzles (120a,120b,120c,120d, 120e; 121a,121b,121c,121d,121e)are separate parts that are mounted to the main body part (140) and/or to a chassis (194) of the robotic Iawnmower (100).

8. The robotic Iawnmower (100) according to any one of the claims 1-7, wherein the water channel arrangement (122, 123) and/or the water spray nozzles (120a, 120b, 120c, 120d, 120e; 121a, 121b, 121c, 121d, 121e) are integrated into the design of the main body part (140) and/or the chassis (194) of the robotic Iawnmower (100).

9. The robotic Iawnmower (100) according to any one of the previous claims, wherein the water channel arrangement (122, 123) is constituted by one or more channel branches (122, 123), each channel branch (122, 123) comprising one or more water spray nozzles(120a,120b,120c,120d,120e;121a,121b,121c,121d,121e).