Autonomous lawn mower or service robot and steering roller therefor

Abstract

The utility model relates to an autonomous lawn mower or a service robot and a steering roller for the autonomous lawn mower or the service robot, the steering roller (12) is provided with a roller (50) with a surrounding peripheral surface (48), and the roller (50) is arranged to roll relative to a foundation (74), especially a lawn. It is proposed that the outer circumferential surface (48) has a cross-section comprising two straight sections (60), which are oriented relative to one another, in particular in an isosceles, obtuse angle manner, and a central arc-shaped section (40), which connects the straight sections in an arc-shaped manner, in particular formed by the sections.

Description

Technical Field

[0001] The utility model relates to a steering roller for an autonomous lawn mower. Background Art

[0002] A deflection roller for an autonomous lawn mower is known having the features of the preamble of claim 1. Reference is made, for example, to publication DE 10 2021 201 899 A1. Deflection rollers are known that have a straight, continuously curved or parabolic outer circumferential cross section of the roller. These deflection rollers can therefore have rollers that are cylindrical, spherical or double-bell shaped.

[0003] Steering rollers are suitable for autonomous lawn mowers, for which the chassis must be supported relative to the foundation or lawn, but must also be able to follow the steering pre-determination of the drive wheels of the autonomous lawn mower. However, the use of steering rollers on autonomous lawn mowers can lead to compaction of grass, especially compaction of grass that is pressed down before the harvesting system. For autonomous lawn mowers whose cutting width is greater than the spacing between steering rollers, this sometimes leads to the fact that the grass that was rolled over and compacted just before the prescribed cutting can only be cut inadequately. This will produce unwelcome wheel tracks on the lawn surface. At the same time, for soft foundations, such as after rainy weather or after irrigation, such as the lawn surface, the steering rollers will sink in so that unwelcome wheel tracks are produced, sometimes even wheel tracks that extend into the turf, and the lawn surface that has been rolled over is produced on the wheel tracks. These will also limit the maneuverability of the autonomous harvester. Utility Model Content

[0004] The utility model relates to a steering roller for a service robot or an autonomous lawn mower and a service robot or an autonomous lawn mower having the steering roller. Advantageous improvements are listed below. With such a steering roller, not only can the area of ​​the grass being pressed down be reduced to a minimum, but also the sinking of the steering roller into the soft foundation is reduced. In short, user satisfaction can be improved and / or reliability can be improved.

[0005] The utility model is based on a steering roller for an autonomous lawn mower or a service robot, in particular a non-driven steering roller, preferably a follower steering roller, which has a roller with a surrounding outer circumference and is arranged to roll relative to a foundation, in particular a lawn surface.

[0006] It is proposed that the outer circumference has a cross section which comprises two straight sections which are oriented in an obtuse angle relative to one another, in particular isosceles, and a central arcuate section which connects the straight sections in an arcuate manner, in particular the cross section being formed by these sections. In principle, the arcuate sections can be joined in the middle region, in particular in the region of the dividing seam, preferably in the roller halves during assembly of the roller, with short straight surfaces, in particular for reasons of production technology. These short straight surfaces, in particular corners for demoulding from the mold, etc., should remain unconsidered in the design of the arcuate sections.

[0007] The deflection roller is also called a caster roller or a caster wheel. It is used as a non-driven support wheel, which can be independently oriented relative to the current direction of movement. The deflection roller has a rotatable roller. The deflection roller has an additional rotation axis extending in the vertical direction. As a result, the deflection roller is a roller that can swing around a vertical axis and can rotate around the roller rotation axis. The roller rotation axis does not intersect the vertical rotation axis. More precisely, they are arranged at a certain distance relative to each other so that the roller can be dragged or has a follow-up property (follow-up deflection roller). The roller rotation axis and the vertical rotation axis are arranged skewed relative to each other. The outer circumference of the deflection roller surrounds the roller rotation axis. "The cross section of the outer circumference" should be understood as a cross section of the outer circumference in the direction of the roller rotation axis. It represents the outer circumference profile in the cross section of the deflection roller or cut along the roller rotation axis.

[0008] It is suggested that the arcuate section is partially circular. It has a bending radius. The bending radius is in particular 10 to 30 mm, preferably 15 to 20 mm, in particular about 18.5 mm. This allows the area or zone of grass that is pressed down when rolling over, in particular when rolling over hay, to be kept small.

[0009] It is proposed that the straight section is formed tangentially to the curved section. The straight section or the axis of the straight section is thus not intersected or exceeded by the curved section. The curved section is thus kept within an obtuse angle range. This makes it possible to prevent the deflection roller from sinking or digging into the foundation, especially in soft or irrigated foundations, etc. A linearly expanding bearing surface is provided depending on the degree of sinking.

[0010] It is proposed that the straight sections are at an angle of 115° to 140°, in particular 125° to 130°, preferably 127° to 128° relative to one another. This makes it possible to prevent the deflection roller from sinking or embedding into the ground, in particular in soft or irrigated ground, etc. The straight cross-sectional sections, which are formed obliquely relative to one another, or the truncated cone-shaped surrounding outer circumference, thus have a constant slope, in particular a constant opposite slope, relative to the roller rotation axis.

[0011] It is recommended that the ratio of roller diameter to bending radius is approximately 3 to 5, in particular approximately 4. In particular, the maximum roller diameter in the center of the roller in the direction of the roller axis of rotation is approximately 75 mm, for example. The bending radius is, for example, 18.5 mm. This makes it possible to achieve a surface pressure that reproducibly bends the grass stalks, in particular on relatively dry lawns.

[0012] It is recommended that the ratio of the angle of the straight section or the angle of the outer circumferential surface of the truncated cone opposite the bottom surface to the roller diameter is 1.5 to 2, in particular about 1.7. For example, the angle can be 125° to 130°. The roller diameter can be 71 mm, for example, in the transition zone to the curved area. The roller diameter can be 65 mm, for example, in the transition zone to the end face of the roller. The diameter of the roller decreases in the straight area or in the obtuse area towards the end face of the roller, in particular constantly or with a constant slope.

[0013] It is suggested that the ratio of the roller diameter to the width of the deflection roller is 1.5 to 2, in particular 1.8 to 1.9. The width of the roller can be 40 mm, for example. The maximum diameter of the outer circumference or the roller can be 75 mm, for example, and the minimum diameter of the roller can be 60 mm, for example.

[0014] The outer circumference of the roller can be said to be formed by two truncated cone-shaped outer circumferences oriented relative to each other, which are connected to each other by an arched or curved connecting surface, in particular an outwardly or convexly arched or curved connecting surface or a barrel-shaped outer circumference. In other words, the outer circumference of the deflecting roller has three circumferential sections along the rotation axis of the deflecting roller: two partial surface sections oriented relative to each other at an obtuse angle and a central partial surface section that is curved outwards and connects the two partial surface sections. It can also be said that the outer circumference is formed by two axially spaced, oppositely outwardly ending truncated cone surfaces, which are connected in the middle by an outwardly arched barrel-shaped outer circumference or annular surface.

[0015] The material of the deflection roller can in principle be a pneumatic rubber tire, a solid rubber tire, etc. However, the deflection roller is formed in particular from hard plastic. Under load, for example in applications with autonomous lawn mowers, the roller at least hardly deforms elastically. In particular, its surface deforms plastically only due to damage or scratches. The surface or rolling surface of the deflection roller is particularly smooth. The surface is particularly not structured or shaped, for example to improve traction relative to the foundation, etc.

[0016] In addition, a steering roller for an autonomous lawn mower or service robot is proposed, the steering roller having a circumferential outer surface which is provided for rolling relative to a foundation, in particular a lawn, wherein the outer surface is formed by two truncated cones or truncated cone outer surfaces which terminate at opposite acute angles, axially located on the outside, and a barrel or barrel-shaped surface which connects the two truncated cones or truncated cone outer surfaces. The truncated cones terminate at an acute angle relative to each other at the distal end, in particular in the axial direction. The cover surfaces of the truncated cones are in particular facing away from each other. The imaginary bottom surfaces of the truncated cones are in particular facing each other. The cover surfaces of the respective truncated cones in particular at least partially form the axial end faces of the roller. The cover surfaces are in particular not completely closed. The truncated cone outer surface in particular forms a rolling surface of the roller, in particular an extended or secondary rolling surface of the roller, which is preferably subjected to force on a soft foundation. The barrel-shaped surface in particular forms the basic rolling surface or primary rolling surface of the roller. The barrel-shaped surface or the convexly outwardly curved circumferential surface connects the truncated cone outer surfaces. The truncated cones are in particular designed to be mirror-symmetrical to one another. The truncated cones are designed to be obtuse-angled to one another. The barrel surface does not extend beyond the outer circumference axis of the truncated cones. The barrel surface is arranged tangentially to the outer circumference axis.

[0017] In addition, an autonomous lawnmower or service robot with the above-mentioned steering roller is proposed. "Service robot" is to be understood in particular as an at least partially automatic, movable device that at least partially actively performs work, preferably the processing of a surface, in particular the so-called processing surface. In particular, the robot should actively start work, actively end work and / or actively select and / or influence at least one parameter related to the processing of the processing surface. In addition, a device should be understood in particular, which actively moves and / or autonomously moves in a predetermined working range of the processing surface at least to perform this work, in particular to process the processing surface. Typical application areas of such robots include a variety of activities, such as sweeping, vacuuming, cleaning, mowing, collecting (gathering), sorting, irrigation, fertilizing, mapping, etc. Examples of this are in particular autonomous sweeping machines, autonomous cleaning robots, autonomous snow removal robots, autonomous vacuum cleaners, autonomous swimming pool cleaning machines, autonomous mopping robots, autonomous seeding machines, autonomous irrigation robots, autonomous fertilizing machines, autonomous mapping machines, autonomous lawnmowers, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Other advantages are derived from the following description of the drawings. An embodiment of the utility model is shown in the drawings. The drawings, the description and the claims contain a large number of features in combination. For those skilled in the art, it is also appropriate to observe the features individually and combine them into other meaningful combinations.

[0019] in:

[0020] Figure 1 An autonomous lawn mower having a steering roller according to the invention is shown;

[0021] Figure 2 The deflection roller according to the utility model is shown in a perspective view;

[0022] Figure 3 The deflection roller according to the utility model is shown in a side view;

[0023] Figure 4 The deflection roller according to the utility model is shown in the front view;

[0024] Figure 5 In accordance with Figure 4 The section AA of the utility model shows the deflection roller

[0025] sectional view of

[0026] Figure 6 An autonomous lawn mower with a steering roller according to the invention is shown in a front view. DETAILED DESCRIPTION

[0027] Figure 1 and 6 An autonomous lawn mower 10 or service robot according to the present invention is shown, which has one or two visible steering rollers 12 according to the present invention. The steering roller 12 is not driven and is configured as a follower roller. The steering roller 12 is arranged at the lower side of the autonomous lawn mower 10, in particular in the front area. The autonomous lawn mower 10 has a housing 14. The autonomous lawn mower has a chassis 16. The autonomous lawn mower 10 has a drive unit 18 for driving a drive wheel 20. The drive unit 18 drives the drive wheel 20 individually, in particular by means of an electric motor. The autonomous lawn mower 10 has an energy supply unit 22, such as a battery pack, in particular a replaceable battery pack for a handheld power tool. The energy supply unit 22 can be charged via a charging contact 58. The autonomous lawn mower 10 has a drive unit 24 for driving a cutting unit 26 or other service units. The cutting unit 26 includes a cutting knife received at a rotating disk. The autonomous lawn mower 10 or service robot has a control or regulating unit 28. The autonomous lawn mower can have sensors or sensor units (not shown). The autonomous lawn mower can have a navigation unit. The autonomous lawn mower can have many other features, which are known to those skilled in the art who are familiar with autonomous lawn mowers or lawn mowing robots or service robots. The autonomous lawn mower 10 or service robot is designed to independently perform service tasks in a working environment, in particular to independently mow a lawn surface.

[0028] The deflection roller 12 is also called a castor roller or castor wheel. It serves as a non-driven support wheel which can be oriented independently with respect to the current direction of movement. The deflection roller 12 has a rotatable roller 50. This roller 50 rotates around a roller rotation axis 46. The deflection roller 12 has an additional rotation axis or steering axis 30 extending in the vertical direction. The deflection roller 12 is thus a roller 50 which can be swiveled around a vertical axis or steering axis 30 and can be rotated around the roller rotation axis 46. The roller rotation axis 46 does not intersect the steering axis 30. Rather, they are spaced apart from each other at a certain distance 44 (cf. Figure 3) so that the roller 50 can be dragged or has followability (hence it is also called a follower roller). The roller rotation axis 46 and the vertical rotation axis or steering axis 30 are thus arranged tilted relative to each other. The deflection roller 12 is designed as a non-driven deflection roller 12. The deflection roller 12 has a surrounding outer circumference 48. The roller 50 or the outer circumference 48 of the roller 50 is provided for rolling relative to a foundation (not shown here), in particular a lawn surface. The outer circumference 48 has the following cross section (see Figure 5 The section AA, but also can be Figure 4 The cross section is formed by two straight sections 60 oriented at an obtuse angle to each other. These straight sections 60 oriented at an obtuse angle to each other are isosceles. The straight sections 60 oriented at an obtuse angle to each other in the cross section are connected by a central peripheral surface section. This central peripheral surface section is arc-shaped. The roller 50 has a rolling surface or peripheral surface 48 that is constructed mirror-symmetrically with respect to a center plane 62 of the roller 50, in particular a center plane 62 normal to the roller rotation axis 46. The outer peripheral surface 48 of the deflection roller 12 or the roller 50 completely, so to speak, surrounds the roller rotation axis 46 by 360° or without interruption. The "cross section of the outer peripheral surface 48" should be understood as a cross section of the outer peripheral surface 48 in the direction of the roller rotation axis 46. It represents the outer peripheral surface contour that can be said to be cut in the cross section of the deflection roller 12 or along the roller rotation axis 46.

[0029] The circumferential outer surface 48 of the roller 50 can be said to be formed by two spaced-apart truncated cone-shaped surfaces 64 oriented relative to one another, which surfaces 64 are connected to one another by an arched or curved connecting surface 66, in particular an outwardly or convexly arched or curved connecting surface 66. In other words, the outer surface 48 of the deflecting roller 12 has three sections along the roller rotation axis 46 of the deflecting roller 12: two outer partial surface sections 38 oriented relative to one another at an obtuse angle and a spherically curved middle partial surface section connecting the two outer partial surface sections 38. It can also be said that the outer surface 48 is formed in the middle by a radially outwardly arched annular outer surface or a barrel-shaped outer surface, which connects two truncated cone outer surfaces that terminate axially outward in opposite directions. The radially outwardly arched annular outer surface or the cylindrical or barrel-shaped outer surface (Fass-oder ) has a radius 68. The bending radius is in particular 10-30 mm, preferably 15-20 mm, here about 18.5 mm. The straight section 60 is formed tangentially to the curved section 40. The axis 70 of the straight section 60 or the obtuse-angled section in the cross section is thus not intersected or exceeded by the curved section 40. The curved section 40 is thus kept within the angular range of the obtuse angle.

[0030] It is proposed that the angle 72 of the straight sections 60 relative to one another is 115° to 140°, in particular 125° to 130°, here approximately 127° to 128°. The sections 60 which are straight in cross section or the surrounding surfaces 64 which are formed obliquely relative to one another thus have a constant slope, in particular a constant opposite slope, relative to the roller axis of rotation 46. The straight sections 60 are formed isosceles. The angle 84 of each of these straight sections 60 relative to the horizontal plane 74 or to the foundation is in particular 20° to 32.5°, here approximately 26° to 27°.

[0031] The ratio of the roller diameter 76 to the bending radius 68 is approximately 3 to 5, in particular approximately 4. The largest roller diameter 76, in particular in the center or the midplane 62 of the roller 50, is, for example, approximately 75 mm here. The bending radius 68 of the arc-shaped section 40 is, for example, 18.5 mm. The ratio of the angle 72 of the straight section 60 to the deflection roller diameter or the roller diameter 76 is approximately 1.5-2, in particular approximately 1.7 here. The deflection roller diameter 78 in the transition zone from the straight area to the curved area can be, for example, 71 mm. The deflection roller diameter 80 in the transition zone to the end face 82 of the roller 50 can be, for example, 60 mm. The diameters 76, 78, 80 of the roller 50 decrease in the straight section 60 or in the obtuse-angled area toward the end face 82 of the roller 50, in particular constantly or with a constant slope (cf. Figure 4 The angle in 84).

[0032] The ratio of the diameter of the deflecting roller 12 or roller diameter 76 to the width 86 of the deflecting roller 12 is, for example, 1.5 to 2, in particular here 1.8 to 1.9. The width 86 of the deflecting roller 12 or roller 50 of the deflecting roller 12 can be, for example, 40 mm. The maximum diameter of the outer circumference or roller 50 can be, for example, 75 mm, the minimum diameter of the roller can be, for example, 60 mm. The width 88 of the curved region or connecting surface or the middle or arcuate section 40 in the direction of the roller rotation axis 46 is, in particular, 15 to 20 mm, in particular here about 16 to 17 mm.

[0033] In addition to the above-described design of the outer circumference 48, the deflection roller 12 is at least in principle and in particular Figure 2 8, 9 and 10 of DE 102021201899 A1 and the associated description of the figures, in particular paragraphs 31 to 50, are constructed similarly and can be seen from the alternative design according to DE 102021201899 A1. In particular, the bearing structure of the roller 50, the design of the deflection roller bearing unit 32a, for example the anti-lock unit with the cover element 46a are essentially the same. In this regard, reference is made to the application DE 102021201899 A1, the content of which is hereby incorporated into the present application.

Claims

1. A steering roller (12) for an autonomous lawn mower (10) or a service robot, comprising a roller (50) with a circumferential outer surface (48), the roller (50) being arranged to roll relative to a base (74), characterized in that: The outer circumferential surface (48) has a cross section comprising two straight sections (60) oriented at an obtuse angle to one another and a central arcuate section (40) connecting the straight sections in an arcuate manner.

2. The deflection roller (12) according to claim 1, characterized in that: The arc-shaped section (40) is designed in the form of a partial circle and has a curvature radius (68).

3. The deflection roller (12) according to claim 1 or 2, characterized in that: The straight section (60) is formed tangentially to the arcuate section (40).

4. The deflection roller (12) according to claim 1 or 2, characterized in that: The angle (72) of the straight sections (60) relative to one another is between 115° and 140°.

5. The deflection roller (12) according to claim 1 or 2, characterized in that: The ratio of the maximum roller diameter (76) to the bending radius (68) is 3 to 5.

6. The deflection roller (12) according to claim 1 or 2, characterized in that: The ratio of the angle (72) of the straight section (60) to the roller diameter (76) is 1.5 to 2.

7. The deflection roller (12) according to claim 1 or 2, characterized in that: The ratio of the roller diameter (76) to the width (86) of the roller (50) is 1.5 to 2.

8. The deflection roller (12) according to claim 1, characterized in that: The roller (50) is configured to roll relative to the lawn.

9. The deflection roller (12) according to claim 1, characterized in that: The two straight sections (60) are oriented isosceles at an obtuse angle relative to one another.

10. The deflection roller (12) according to claim 1, characterized in that The outer circumferential surface (48) has a cross section formed by two straight sections (60) oriented at an obtuse angle to one another and an arcuate section (40) connecting the straight sections in an arcuate manner.

11. The deflection roller (12) according to claim 2, characterized in that: The bending radius (68) is 10 to 30 mm.

12. The deflection roller (12) according to claim 2, characterized in that The bending radius (68) is 15 to 20 mm.

13. The deflection roller (12) according to claim 2, characterized in that: The bending radius (68) is 18.5 mm.

14. The deflection roller (12) according to claim 4, characterized in that The angle (72) of the straight sections (60) relative to one another is 125° to 130°.

15. The deflection roller (12) according to claim 4, characterized in that The angle (72) of the straight sections (60) relative to one another is 127° to 128°.

16. The deflection roller (12) according to claim 5, characterized in that The ratio of the maximum roller diameter (76) to the bending radius (68) is 4.

17. The deflection roller (12) according to claim 6, characterized in that The ratio of the angle (72) of the straight section (60) to the roller diameter (76) is 1.

7.

18. The deflection roller (12) according to claim 7, characterized in that The ratio of the roller diameter (76) to the width (86) of the roller (50) is 1.8 to 1.

9.

19. A steering roller (12) for an autonomous lawn mower (10) or a service robot, comprising a roller (50) with a circumferential outer surface (48), the roller (50) being configured to roll relative to a base (74), characterized in that: The outer peripheral surface (48) is formed by two truncated cone surfaces which terminate at opposite acute angles and are located axially outward, and a barrel surface connecting the two truncated cone surfaces.

20. An autonomous lawn mower (10) or service robot, characterized in that The autonomous lawn mower (10) or the service robot has a steering roller (12) according to any one of claims 1 to 19.

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