Automatic mower

Abstract

An automatic mower comprises a housing provided with a bottom shell, a moving module, a cutting mechanism provided with a cutting element and a control module; the automatic mower further comprises a movable guard provided with a movable guard wall for safety protection, the movable guard wall is arranged outside the cutting mechanism in a horizontal direction, the movable guard wall has an initial distance from the ground in a free state without external force, the cutting mechanism is at an arbitrary cutting height, the initial distance is unchanged, and the initial distance is always less than M, wherein 38mm≤M≤40mm; under the action of external force, the movable guard can produce relative movement in the up-down direction compared with the bottom shell, so that the distance from the ground of the lower end of the movable guard wall can change.

Description

TECHNICAL FIELD

[0001] The present application relates to an automatic mower. BACKGROUND

[0002] With the continuous progress of computer technology and artificial intelligence technology, automatic mowers similar to intelligent robots have begun to slowly enter people's lives. Automatic mowers can automatically mow grass in the user's lawn, charge, and do not require user intervention. This automatic work system does not need to invest effort in management after being set up once, and liberates users from cleaning, lawn maintenance and other boring and time-consuming and laborious housework.

[0003] The automatic mower automatically walks and mows on the grass, which includes a cutting element for cutting. In order to avoid the cutting element of the automatic mower from injuring fingers or arms, etc., a protective member for blocking fingers or arms must be provided outside the cutting element. However, the protective member cannot be set too low to satisfy the passability of the automatic mower, because if the protective member is set too low from the ground, it will result in poor passability of the automatic mower. In order to satisfy the passability, the protective member cannot block the fingers and arms of children from extending into the automatic mower, which can easily cause children to be injured by the automatic mower.

[0004] Therefore, it is necessary to design an automatic mower with a new protective assembly to solve the above problems. SUMMARY

[0005] In order to overcome the above defects, the present application adopts the following technical solutions:

[0006] An automatic mower, comprising:

[0007] a housing provided with a bottom shell;

[0008] a moving module arranged below the housing for driving the automatic mower to move;

[0009] a cutting mechanism arranged in the housing to perform a cutting task of a predetermined cutting height, the cutting mechanism comprising a cutting element for cutting;

[0010] a control module for autonomously controlling the moving module to drive the automatic mower to move, and autonomously controlling the cutting mechanism to perform a cutting task;

[0011] The automatic mower further comprises a movable guard element provided with a movable guard wall for safety protection, the movable guard wall is arranged outside the cutting mechanism in the horizontal direction, in the free state without external force, the distance between the lower end of the movable guard wall and the ground is an initial distance, the cutting mechanism is at any cutting height, the initial distance is unchanged, and the initial distance is always less than M, wherein 38mm≤M≤40mm; under the action of external force, the movable guard element can move relatively to the bottom shell in the upward and downward directions, so that the distance between the lower end of the movable guard wall and the ground can be changed.

[0012] Further, in the process of adjusting the height of the cutting mechanism, the cutting mechanism can move relative to the movable guard wall.

[0013] Further, under the action of external force, the movable guard element can move upward as a whole relative to the bottom shell, so that the distance between all points on the lower surface of the movable guard wall and the ground is increased.

[0014] Further, under the action of external force, the lower end of the movable guard wall moves upward by a distance not less than 15mm.

[0015] Further, under the action of external force, the lower end of the movable guard wall can move in the upward and downward directions by a distance ranging from 15mm to 80mm, or from 20mm to 40mm.

[0016] Further, the cutting mechanism is at any cutting height, under the action of external force, the movable guard element can move upward relative to the bottom shell, so that the distance between the movable guard wall and the ground is increased; when the external force is eliminated, the movable guard element can move downward relative to the bottom shell, so that the distance between the lower end of the movable guard wall and the ground returns to the initial distance.

[0017] Further, the movable guard wall further comprises a vertical guard wall extending in the upward and downward directions, and a horizontal guard wall located below the vertical guard wall and extending in the horizontal direction, the outermost side of the horizontal guard wall protrudes beyond the outermost side of the vertical guard wall.

[0018] Further, the automatic mower further comprises a guard element upward guiding mechanism for connecting the shell and the movable guard element.

[0019] Further, the upward guiding mechanism comprises at least one of four connecting rods, two connecting rods, a single rod or a sliding groove.

[0020] Further, the initial distance ranges from 15mm to 35mm.

[0021] Further, the initial distance is less than or equal to M / 2.

[0022] Further, the movable protective wall comprises at least one of a front movable protective wall in front of the cutting mechanism, side movable protective walls on both sides of the cutting mechanism, and a rear movable protective wall behind the cutting mechanism.

[0023] Further, the movable protective wall comprises at least one of a front movable protective wall in front of the cutting mechanism, side movable protective walls on both sides of the cutting mechanism, and a rear movable protective wall behind the cutting mechanism.

[0024] Further, in the horizontal direction, the minimum distance X between the outermost edge of the movable protective wall and the cutting element is in the range of X≥58mm, or 63mm≤X≤75mm.

[0025] Further, the movable protective wall is arranged outside the housing, and / or arranged between the cutting mechanism and the housing, and / or connected to a part of the housing.

[0026] Further, the automatic mower further comprises a mechanism protective wall arranged between the movable protective wall and the cutting mechanism in the horizontal direction, the mechanism protective wall is relatively fixed with the cutting mechanism in the vertical direction, and the lower end of the mechanism protective wall is always lower than the lowest point of the cutting element.

[0027] Further, in at least one cutting height, the movable protective wall can relatively move with the cutting mechanism in the vertical direction under the action of an external force, and the automatic mower further comprises a limiting mechanism for limiting the degree of relative movement between the cutting mechanism and the movable protective wall in the vertical direction, and the lower end of the movable protective wall is always lower than the lowest point of the cutting element under the limitation of the limiting mechanism.

[0028] The beneficial effects of the present scheme are: by arranging the movable protective wall with an initial position always unchanged, the safety of children is ensured at any cutting height. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is a perspective view of an automatic mower according to an embodiment of the present application.

[0030] Figure 2 is Figure 1 is another angle view of the automatic mower shown.

[0031] Figure 3 is Figure 1 Another angle view of the automatic mower.

[0032] Figure 4 is a state diagram of a protection assembly of the automatic mower in an embodiment of the present application.

[0033] Figure 5 is a state diagram of a protection assembly of the automatic mower in an embodiment of the present application.

[0034] Figure 6 is a state diagram of a protection assembly of the automatic mower in an embodiment of the present application.

[0035] Figure 7 is a state diagram of a protection assembly of the automatic mower in an embodiment of the present application.

[0036] Figure 8 is a state diagram of a protection assembly of the automatic mower in an embodiment of the present application.

[0037] Figure 9 is a state diagram of a protection assembly of the automatic mower in an embodiment of the present application.

[0038] Figure 10 is a diagram of a cutting mechanism and a protection assembly of the automatic mower in an embodiment of the present application.

[0039] Figure 11 is a diagram of a cutting mechanism and a protection assembly of the automatic mower in an embodiment of the present application.

[0040] Figure 12 is a state diagram of a protection assembly of the automatic mower in an embodiment of the present application.

[0041] Figure 13 is a state diagram of a protection assembly of the automatic mower in an embodiment of the present application.

[0042] Figure 14 is a state diagram of a protection assembly of the automatic mower in an embodiment of the present application.

[0043] Figure 15 is a state diagram of a protection assembly of the automatic mower in an embodiment of the present application.

[0044] Figure 16 is a diagram of a protection assembly of the automatic mower in an embodiment of the present application.

[0045] Figure 17 is a diagram of a protection assembly of the automatic mower in an embodiment of the present application.

[0046] Figure 18 is a schematic view of a protective assembly of an automatic mower in an embodiment of the present application.

[0047] Figure 19 is a schematic view of a protective assembly of an automatic mower in an embodiment of the present application.

[0048] Figure 20 is a schematic view of a protective assembly of an automatic mower in an embodiment of the present application.

[0049] Figure 21 is a schematic view of a protective assembly of an automatic mower in an embodiment of the present application.

[0050] Figure 22 is Figure 21 is another angle view.

[0051] Figure 23 is a schematic view of the outermost edge of a movable protective element in an embodiment of the present application.

[0052] Figure 24 is a schematic view of an automatic mower in an embodiment of the present application.

[0053] is another angle view. Figure 24 is another angle view.

[0054] is another angle view. Figure 24 is another angle view.

[0055] Figure 27 is a schematic view of an automatic mower in an embodiment of the present application.

[0056] Figure 28 is another angle view. Figure 27 is another angle view.

[0057] Figure 29 is another angle view. Figure 27 is another angle view.

[0058] Figure 30 is a schematic view of an automatic mower in an embodiment of the present application.

[0059] Figure 31 is another angle view. Figure 30 is another angle view.

[0060] Figure 31 is another angle view. Figure 30 is another angle view.

[0061] Figure 32 is a schematic view of a movable protective element and a mechanism protective element in an embodiment of the present application.

[0062] Figure 33 Fig. 2 is a schematic diagram of the movable guard member shown in Fig. 1 under a non-vertically outward force. Figure 32 Fig. 3 is a schematic diagram of the movable guard member shown in Fig. 1 under a non-vertically outward force.

[0063] Figure 34 Fig. 4 is a schematic diagram of the movable guard member shown in Fig. 1 under a non-vertically outward force. Figure 32 Fig. 5 is a schematic diagram of the movable guard member shown in Fig. 1 under a non-vertically outward force.

[0064] Figure 35 Fig. 6 is a schematic diagram of the movable guard member shown in Fig. 1 under a non-vertically outward force.

[0065] Figure 36 Fig. 7 is a schematic diagram of the movable guard member shown in Fig. 1 under a non-vertically outward force. Figure 35 Fig. 8 is a schematic diagram of the movable guard member shown in Fig. 1 under a non-vertically outward force.

[0066] Figure 37 Fig. 9 is a schematic diagram of the movable guard member shown in Fig. 1 under a non-vertically outward force. Figure 35 Fig. 10 is a schematic diagram of the movable guard member shown in Fig. 1 under a non-vertically outward force.

[0067] Figure 38 Fig. 11 is a schematic diagram of the movable guard member shown in Fig. 1 under a non-vertically outward force. Figure 35 Fig. 12 is a schematic diagram of the movable guard member shown in Fig. 1 under a non-vertically outward force.

[0068] Figure 39 Fig. 13 is a schematic diagram of the movable guard member shown in Fig. 1 under a non-vertically outward force. Figure 35 Fig. 14 is a schematic diagram of the movable guard member shown in Fig. 1 under a non-vertically outward force.

[0069] Figure 40 Fig. 15 is a schematic diagram of the movable guard member shown in Fig. 1 under a non-vertically outward force.

[0070] Figures 41-43 Fig. 16 is a schematic diagram of the movable guard member shown in Fig. 1 under a non-vertically outward force. Figure 40 Fig. 17 is a schematic diagram of the movable guard member shown in Fig. 1 under a non-vertically outward force.

[0071] Figure 44 Fig. 18 is a schematic diagram of the movable guard member shown in Fig. 1 under a non-vertically outward force. Figure 40 Fig. 19 is a partial enlarged view of Fig. 18.

[0072] Figure 45 Fig. 20 is a schematic diagram of the movable guard member shown in Fig. 1 under a non-vertically outward force. DETAILED DESCRIPTION

[0073] In order to make the objectives, technical solutions, and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely intended to explain the present application and should not be used to limit the present application.

[0074] As shown in Fig. 1, the movable guard member 1 is connected to the mechanism guard member 2 through a connecting member 3. Figures 1-20As shown, the present application provides an automatic working system, which comprises an automatic mower 1 autonomously moving and working, and a charging station for charging the automatic mower 1. The automatic mower 1 comprises a housing 10 provided with a bottom shell 101, a moving module 20 arranged below the housing 10 and used to drive the automatic mower 1 to move, a cutting mechanism 3 used to perform a cutting task at a predetermined cutting height, a power module used to provide power, a control module used to automatically control the moving module to drive the automatic mower 1 to move and autonomously control the cutting mechanism to perform the cutting task, and an energy module 5 used to provide energy.

[0075] The cutting mechanism 3 is rotatably fixed below the housing 10, and comprises a cutter disc 31 rotatably fixed below the housing 10, a plurality of cutting elements 32 fixed on the cutter disc 31, and a fastener 33 used to fix the cutting elements 32 on the cutter disc 31. In this embodiment, the cutting mechanism 3 further comprises a rotating part 36 rotatably fixed below the housing 10, and the cutter disc 31 is fixed on the rotating part 36 and can rotate with the rotating part 36. The cutting elements 32 are cutting blades, which are uniformly fixed on the circumference of the cutter disc 31 to rotate with the cutter disc 31. In an embodiment, the cutting mechanism 3 comprises three cutting blades, and in other embodiments, the number of cutting blades can be determined according to actual conditions, for example, the cutting elements are two or more than three.

[0076] The height of the cutting mechanism 3 relative to the ground can be adjusted so that the automatic mower 1 can cut grass at different heights. Specifically, there are various ways to adjust the height of the cutting mechanism 3. In an embodiment, the automatic mower 1 further comprises a height adjustment structure 6 for adjusting the height of the cutting mechanism. When the automatic mower 1 needs to adjust the cutting height, the height adjustment structure 6 is operated, and the cutting mechanism 3 can move up and down under the drive of the height adjustment structure 6 to adjust the height of the cutting mechanism 3 and achieve the adjustment of the cutting height. During the adjustment of the cutting height from the lowest gear to the highest gear, the cutting mechanism 3 can move relative to the movable guard in the up-down direction, for example, the cutting mechanism 3 moves relative to the housing 10 in the up-down direction, the cutting mechanism 3 moves relative to the ground in the up-down direction, and the movable guard 41 does not move relative to the ground in the up-down direction, that is, the initial distance between the lower end of the movable guard wall and the ground remains unchanged. The lowest state 411 of the movable guard 41 remains unchanged, so that the height adjustment does not affect the safety protection effect of the automatic mower 1. In this embodiment, the initial distance between the lower end of the movable guard wall and the ground remains unchanged during the adjustment of the cutting height from the lowest gear to the highest gear. In other embodiments, the initial distance between the lower end of the movable guard wall and the ground remains unchanged during the adjustment of some gears, and the initial distance between the lower end of the movable guard wall and the ground changes during the adjustment of some gears. In another embodiment, the automatic mower 1 can also adjust the distance between the cutting element 32 and the ground by reversing the cutting disc 31 or replacing the cutting disc 31 to achieve the purpose of adjusting the cutting height. In this embodiment, the cutting height is adjusted without changing the movable guard 41, that is, the position relationship between the movable guard 41 and the housing 10 remains unchanged, and the cutting disc 31 is directly replaced. Of course, in some embodiments, the height of the cutting mechanism 3 relative to the ground can also be fixed and cannot be adjusted.

[0077] In the non-height adjustment state, the cutting mechanism 3 can be fixed relative to the housing, or can be movable relative to the housing. For example, the cutting mechanism 3 can move relative to the housing in the up-down direction. When an external force acts on the lower part of the cutting mechanism 3, for example, when an upward external force is applied to the cutting mechanism 3 by an obstacle below the cutting mechanism 3, the cutting mechanism 3 can move upward relative to the housing to avoid the obstacle and avoid the collision between the obstacle and the blade, and improve the passability.

[0078] As Figure 2 and Figure 3As shown, the automatic mower 1 further comprises a guard assembly 4 for a guard wall 40 for safety protection, which is arranged outside the cutting mechanism 3 in the horizontal direction to prevent people from accidentally touching the cutting mechanism 3 from the outside and causing accidental injury to people. The guard assembly 4 at least comprises a movable guard piece 41 provided with a movable guard wall 414 for safety protection, and the movable guard wall 414 is arranged on the movable guard piece 41 and outside the cutting mechanism 3 in the horizontal direction. During the movement of the automatic mower 1, when the movable guard wall 414 is subjected to a proper external force, the distance between the lower end of the movable guard wall 414 and the ground in the vertical direction can be changed, so that when the automatic mower 1 encounters an obstacle 62, the movable guard wall 414 is subjected to a sufficient external force, and the distance between the lower end 417 of the movable guard wall of the movable guard piece 41 and the ground can be increased to quickly pass through the obstacle, thereby improving the passability of the automatic mower 1. The lower end of the movable guard wall 414 can also be referred to as the lower end 417 of the movable guard wall.

[0079] The maximum value M of the preset child arm diameter is always less than M, so as to prevent the child's arm from being able to stretch into the cutting mechanism 3 near the automatic mower 1 through the bottom of the movable guard piece 4, thereby causing the risk of being accidentally injured by the cutting mechanism 3. Generally, the maximum value M of the child arm diameter is in the range of 38mm-40mm (including 38mm and 40mm), i.e. 38mm≤ M≤ 40mm. The distance between the lower end of the guard assembly 4 and the ground can be correspondingly set to 15mm, 19mm, 25mm, 35mm, 37mm, 39mm, etc. Of course, in other embodiments, the range of M can be adjusted according to actual conditions, for example, in order to protect thinner arms, M is set to be smaller, or in order to protect thicker arms, M is set to be larger. Taking M=38mm as an example, i.e. the distance between the lower end of the guard assembly 4 and the ground is always less than 38mm, the free state of the above-mentioned guard assembly 4 refers to the state of the guard assembly 4 when the cutting mechanism 3 is at any cutting height and the automatic mower 1 is not subjected to any external force. When the guard assembly 4 is in the free state, when an arm with a diameter greater than M attempts to stretch into the automatic mower 1 from below the movable guard piece 41, it is blocked by the lower end of the guard assembly 4 and cannot stretch into the movable guard piece 41. In an embodiment, the distance between the lower end of the guard assembly 4 and the ground is in the range of 15-35mm, so that the distance between the lower end of the guard assembly 4 and the ground can prevent the child's arm from stretching in, and at the same time, the guard assembly 4 will not be too close to the ground to affect its normal walking on the lawn.

[0080] There are many ways to change the distance between the lower end 417 of the movable protective wall of the movable protective member 41 and the ground. For example, the movable protective member 41 can move in the up and down directions compared to the bottom shell to change the distance between the lower end of the movable protective wall and the ground; for example, the movable protective member 41 can move in the up and down directions as a whole compared to the bottom shell, so that the movable protective wall as a whole moves in the up and down directions compared to the ground; or, the movable protective member 4 only partially moves in the up and down directions compared to the bottom shell, so that the distance between the local movable protective wall and the ground can be changed; or, the distance between the upper end of the movable protective member 4 and the ground remains unchanged, while the distance between the lower end 417 of the movable protective wall and the ground can be changed. For example, the distance between the lower end 417 of the movable protective wall and the ground can be generated by rotation or deformation.

[0081] In one embodiment, if Figures 1-18 As shown, the bottom shell of the housing 10 does not move in the vertical direction relative to the ground, while the movable protective member 41 can move in the vertical direction relative to the bottom shell of the housing 10 to achieve its vertical movement relative to the ground. Figures 1-3 As shown, the movable protective member 41 is arranged between the housing 10 and the cutting mechanism 3, and is arranged independently of the housing 10. Figures 16-17 As shown, the movable protective member 41 is disposed outside the housing 10, and the movable protective member 41 can move in the up and down directions relative to the bottom shell of the housing 10. Figures 16-17 As shown, it is completely covered outside the shell 10 to form the upper cover of the automatic lawn mower 1, and can also be as shown in FIG. Figure 18 The movable protective member 41 is disposed on a portion of the housing 10 , for example, at the edges of the front, rear, and sides of the housing 10 .

[0082] In another embodiment, the movable protective member 41 may be fixed relative to the housing, and the distance of the housing 10 relative to the ground may be variable. For example, the connection between the mobile module and the housing 10 may be changed, so that the distance of the housing 10 relative to the ground may be changed. Figures 19-20 As shown, the distance between the upper end of the movable protective member 41 and the ground remains constant, while the distance between the lower end 417 of the movable protective wall and the ground changes by deforming the movable protective member 41 when it strikes an obstacle. In another embodiment, the distance between the upper end of the movable protective member 41 and the ground remains constant, and the upper end of the movable protective member 41 is fixed relative to the housing 10, while the distance between the lower end 417 of the movable protective wall and the ground changes by rotating the movable protective member 41 about its upper end. In other embodiments, the movable protective member 41 may also use other methods to achieve a variable distance between the lower end 417 of the movable protective wall and the ground, which are not listed here.

[0083] The cutting element 32 comprises a cutting element lowest point 30, which is located in the lowest position of the cutting element in the up-down direction. Regardless of the cutting height of the cutting mechanism 3, when the automatic mower 1 is moving, when it encounters a child's arm, for example Figure 8 a test arm 61 with a diameter M, at this time, the test arm 61 is equivalent to the obstacle 62, which exerts a force on the movable protective wall 414 sufficient to move the movable protective wall 414 upward. When the movable protective wall 414 is subjected to an external force and its lower end moves upward, if the lower end of the protective assembly 4 is able to be greater than or equal to M from the ground, for example, the distance between the lower end 417 of the movable protective wall and the ground is able to be greater than or equal to M, and the lower end of the protective assembly 4 moves to a height higher than the cutting element lowest point 30, then when the automatic mower 1 is moving, it encounters a child's arm, it will directly crush and the arm can directly enter the vicinity of the cutting mechanism 3 through the protective assembly 4 and be cut by the cutting element 32. In this embodiment, as shown in Figure 8 , Figure 11 the movable protective member 41 is in a free state and the lower end of the movable protective wall is lower than the cutting element lowest point, when the movable protective member 41 is subjected to an inward force and moves upward to the highest point of its movable range, the lower end of the blocking wall 40 of the protective assembly 4 is always lower than the cutting element lowest point 30, so that when the automatic mower 1 is moving, even if it encounters a child's arm (simulated by the test arm 61), the arm can enter the vicinity of the cutting mechanism 3 from the protective assembly 4, because the lower end of the blocking wall 40 of the protective assembly 4 is always lower than the cutting element lowest point 30, the test arm 61 can only be located below the cutting element 30 and cannot touch the cutting element 32, thereby avoiding being cut. Of course, in other embodiments, the lower end of the blocking wall 40 of the protective assembly 4 can be always lower than the cutting element lowest point 30 by limiting the distance between the lower end of the movable protective wall 417 and the ground regardless of the height of the cutting mechanism 3 or the arbitrary cutting height of the cutting mechanism 3, and the distance between the lower end of the blocking wall 40 of the protective assembly 4 and the ground is always less than M. Specifically, the distance between the lower end of the movable protective wall 417 and the ground can be always limited to be less than M to limit the arm from entering the cutting mechanism 3 from below the protective assembly 4 regardless of how it is.

[0084] because the lower end of the blocking wall 40 of the protective assembly 4 is always lower than the cutting element lowest point 30, the test arm 61 can only be located below the cutting element 30, as shown in Figure 8 a diagram showing that the cutting height is higher than the diameter of the child's arm, at this time, the height of the cutting mechanism 3 from the ground is greater than the diameter of the child's arm.

[0085] Specifically, there are various ways to ensure that the lower end of the barrier wall 40 of the protective assembly 4 is always below the lowest point 30 of the cutting element. For example, in one embodiment, when the movable protective member 41 is forced to move upward, its upward movement is restricted, ensuring that the lower end 417 of the movable protective wall is always located at the lowest point 30 of the cutting element. In another embodiment, the movable protective member 41 can be made to move synchronously with the cutting mechanism 3, so that the distance between the lower end 417 of the movable protective wall and the lowest point 30 of the cutting element remains constant, thereby ensuring that the lower end 417 of the movable protective wall is always located at the lowest point 30 of the cutting element. In another embodiment, a mechanical protective member 42 can be added, whose lower end is always below the lowest point 30 of the cutting element, to ensure that the lower end of the barrier wall 40 of the protective assembly 4 is always below the lowest point 30 of the cutting element, and so on.

[0086] The following describes a mechanism guard 42, whose lower end is always below the lowest point 30 of the cutting element, as an example. In this embodiment, the guard assembly 4 also includes a mechanism guard 42 having a mechanism guard wall 424. Horizontally, the mechanism guard wall 424 of the robotic lawn mower is positioned between the cutting mechanism 3 and the movable guard wall. The guard wall 40 includes the movable guard wall and the mechanism guard wall 424. The mechanism guard 42 is fixed relative to the cutting mechanism 3. The cutting mechanism 3 can move relative to the housing or remain stationary, depending on the situation. When the cutting mechanism 3 moves relative to the housing, the mechanism guard 42 moves with it. When the cutting mechanism 3 remains stationary relative to the housing, the mechanism guard 42 also remains stationary. In this embodiment, the mechanism guard 42 is completely fixed relative to the cutting mechanism 3 and cannot move relative to it in any direction. However, in other embodiments, the mechanism guard 42 can be fixed only in the vertical direction relative to the cutting mechanism 3, allowing the two to move relative to each other in directions other than the vertical direction. The mechanism guard 42 includes a mechanism protection wall 424 for protection. The cutting mechanism 3 includes a cutting element lowest point 30 at its lowest vertical position. The mechanism guard 42 is fixed relative to the cutting mechanism 3 in the vertical direction. That is, the relative position of the mechanism guard 42 and the cutting mechanism 3 remains unchanged in the vertical direction. The lower end of the mechanism protection wall 424 of the mechanism guard 42, namely the mechanism protection wall lower end 427, is always lower than the cutting element lowest point 30. This ensures that the lower end of the protection wall 40 is always lower than the cutting element lowest point 30, preventing children's arms from being crushed by the robotic lawn mower 1.

[0087] like Figure 4 and Figure 6As shown, the mechanism guard 42 is located between the cutting mechanism 3 and the movable guard 41 in the horizontal direction, and the minimum distance between the movable guard 41 and the mechanism guard 42 is 2-30 mm, so that the movable guard 41 does not interfere with the mechanism guard 42 during upward movement. In an embodiment, the minimum distance between the movable guard 41 and the mechanism guard 42 is 2-8 mm, which not only ensures that the movable guard 41 does not interfere with the mechanism guard 42 during movement, but also reduces the distance between the movable guard 41 and the mechanism guard 42, making the overall structure of the automatic mower 1 more compact.

[0088] The mechanism guard 42 includes a mechanism guard wall 424 and a fixed connection wall 425 for connecting the mechanism guard wall 424 and the housing 10. In the vertical direction, the mechanism guard wall 424 is fixed relative to the cutter head 31, that is, the relative position of the mechanism guard wall 424 and the cutter head 31 in the vertical direction does not change. The mechanism guard wall 424 includes a plurality of fixed guard teeth 4246, a plurality of fixed grass inlets 4247 located between two adjacent fixed guard teeth 4246, and a connection portion 4248 for connecting adjacent fixed guard teeth 4246. The width of the fixed grass inlet 4247 is 1-M, and the width of the fixed guard tooth 4246 is 1-20 mm, which can allow grass to enter while preventing a child's arm from passing through the fixed grass inlet 4247 of the mechanism guard 42 to touch the cutting mechanism 3. If the fixed grass inlet 4247 is too wide, the effective length of the fixed guard tooth 4246 will be reduced. In an embodiment, the width of the fixed grass inlet 4247 is 10-25 mm, which not only ensures the effective length of the fixed guard tooth 4246, but also prevents a child's arm from passing through the mechanism guard 42 while allowing an appropriate amount of grass to enter the cutting mechanism 3 during movement of the automatic mower 1, thereby preventing the amount of entering grass from being too small, which can cause low work efficiency or grass blockage. The width of the fixed guard tooth 4246 is 4-10 mm, which not only improves the rigidity of the fixed guard tooth 4246, but also prevents the width of the fixed guard tooth 4246 from being too large, which can cause grass blockage. In an embodiment, the movable guard 41 also includes a plurality of movable guard teeth 4146, a plurality of fixed grass inlets 4147 located between two adjacent movable guard teeth 4146, and a connection portion 4148 for connecting adjacent movable guard teeth 4146. The fixed grass inlet 4247 and the movable grass inlet 4147 are arranged in front of and behind each other in the direction in which the automatic mower 1 moves forward, so that the grass can pass through the movable grass inlet 4147 and the fixed grass inlet 4247 in sequence along a straight line, thereby preventing grass from being stuck. The fixed guard teeth 4246 and the movable guard teeth 4146 are respectively distributed along the circumference outside the cutting mechanism 3 to form a safety guard outside the cutting mechanism 3.

[0089] As shown in Figure 21 and Figure 22 In the direction of the forward movement of the automatic mower 1, the mechanism guard wall 424 includes a front mechanism guard wall 4241 in front of the cutting mechanism 3, side mechanism guard walls 4243 on both sides of the cutting mechanism, and a rear mechanism guard wall 4242 behind the cutting mechanism. The lower ends 427 of the front mechanism guard wall 4241, the rear mechanism guard wall 4242, and the side mechanism guard wall 4243 are all lower than the lowest point 30 of the cutting element.

[0090] In this embodiment, to ensure that the child's arm cannot touch the cutting element 30 from any direction, the mechanism guard wall 424 is provided around the mechanism guard 42, that is, as shown in Figure 21 and Figure 22 In the direction of the forward movement of the automatic mower 1, the front mechanism guard wall 4241, the rear mechanism guard wall 4242, and the side mechanism guard wall 4243 together form a circumferentially closed mechanism guard wall. The lower ends of the front mechanism guard wall 4241, the rear mechanism guard wall 4242, and the side mechanism guard wall 4243 are all lower than the lowest point 30 of the cutting element. In this embodiment, the lowest part of the mechanism guard wall in the 360-degree circumferential direction is lower than the lowest point 30 of the cutting element. In another embodiment, the lowest part of the mechanism guard wall in the 360-degree circumferential direction can be at least partially higher than the lowest point of the cutting element, at least partially lower than the lowest point of the cutting element, and the length of the part continuously extending in the circumferential direction which is higher than the lowest point of the cutting element is less than M to avoid the child's arm from entering. In other embodiments, the mechanism guard wall 424 includes at least one of the front mechanism guard wall 4241 in front of the cutting mechanism 3, the side mechanism guard wall 4243 on both sides of the cutting mechanism, and the rear mechanism guard wall 4242 behind the cutting mechanism.

[0091] In an embodiment, as shown in Figure 1As shown, the mechanism protection wall 424 includes at least one of a front mechanism protection wall 4241 located in front of the cutting mechanism 3 and side mechanism protection walls 4243 located on either side of the cutting mechanism 3, thereby preventing a child's arms from being cut by extending into the vicinity of the cutting mechanism 3 from the front or rear. Since the direction of the external force applied to the movable protection wall from the rear of the automatic lawn mower 1 from the outside inward is opposite to the direction of movement of the obstacle 62 relative to the automatic lawn mower 1 when the automatic lawn mower 1 is moving forward (from the inside out), the external force can be separated from the obstacle 62. For example, the rear of the automatic lawn mower 1 can prevent a child's arm from being injured by limiting the resistance to the movable protection wall 414 when it moves upward from the outside inward, thereby preventing the lower end 417 of the movable protection wall from moving upward or preventing it from moving upward beyond the lowest point 30 of the cutting element. Since the direction of the force applied from outside to inside in the front of the automatic lawn mower 1 is the same as the direction of movement of the obstacle 62 relative to the automatic lawn mower 1, the direction of the force applied from outside to inside on both sides is not completely opposite to the direction of movement of the obstacle 62 relative to the automatic lawn mower 1, and it is impossible to distinguish the force applied from outside to inside from the obstacle 62. Therefore, in this embodiment, a front mechanism protective wall 4241 and / or a side mechanism protective wall 4243 can be added to the front and both sides of the automatic lawn mower 1.

[0092] like Figures 1-3 As shown, the shell 10 includes a high shell 49 located outside the cutting mechanism 3 in the horizontal direction. In the direction from the outside to the inside (in the horizontal direction), and in the range of M extending perpendicular to the direction from the outside to the inside, the distance between the high shell 49 and the ground is always higher than M. Therefore, at this time, a child's arm can pass from the bottom of the high shell 49 to the vicinity of the cutting element 32 and be cut. Therefore, in the horizontal direction, or in the inside and outside directions of the automatic lawn mower, at least part of the mechanism protection wall 424 is located between the high shell 49 and the cutting mechanism 3 to prevent the child's arm from reaching the vicinity of the cutting element 32 from the bottom of the high shell 49 and being cut.

[0093] In other embodiments, different implementations may be selected according to the movement of the movable protective member 41 to ensure that the lower end of the protective assembly 4 is always lower than the lowest point 30 of the cutting element.

[0094] The following is a specific description of the example in which the movable protective member 41 can move in the up and down directions relative to the bottom shell of the housing 10 under the action of an external force to change the distance between the lower end of the movable protective wall and the ground.

[0095] like Figures 1-3As shown, the movable protective member 41 includes a plurality of movable protective walls 414 for blocking a user's arms, fingers, or other foreign objects, and a movable connecting wall 415 for connecting the movable protective walls to the housing. The movable protective walls 414 include at least one of a front movable protective wall 4141 disposed in front of the cutting mechanism 3, side movable protective walls 4142 disposed on both sides of the cutting mechanism 3, and a rear movable protective wall 4143 disposed behind the cutting mechanism 3. In this embodiment, the movable protective wall 414 includes the front movable protective wall 4141, the side movable protective walls 4142, and the rear movable protective wall 4143 as an example. Among them, the front movable protective wall 4141, the side movable protective wall 4142 and the rear movable protective wall 4143 can be fully or partially connected to each other into one body, and then connected to the shell 10 through the movable connecting wall 415. The front movable protective wall 4141, the side movable protective wall 4142 and the rear movable protective wall 4143 can also not be connected to each other, but are respectively connected to the shell 10 through the movable connecting wall 415. The front movable protective wall 4141, the side movable protective wall 4142 and the rear movable protective wall 4143 can be directly extended from the movable connecting wall 415, or they can be formed separately and then assembled on the movable connecting wall 415. The movable protective wall 414 includes a plurality of movable protective teeth 4146 and a plurality of movable grass inlets 4147 located between two adjacent movable protective teeth 4146. As Figure 1As shown, in an embodiment, only the front movable protective wall 4141 is provided with a plurality of movable protective teeth 4146 and movable grass inlet openings 4147, so that when the automatic mower 1 moves forward, the grass can not be blocked by the movable protective teeth 4146 and enter the cutting mechanism 3 through the movable grass inlet openings 4147. In other embodiments, the rear movable protective wall 4143 and the side movable protective wall 4142 can also be correspondingly provided with a plurality of movable grass inlet openings 4147 to prevent grass from being crushed. The width of the movable grass inlet opening 4147 is 1- M, and the width of the movable protective tooth 4146 is 1-20 mm, so that the grass can enter while avoiding the child's arm from passing through the movable grass inlet opening 4147 to touch the cutting mechanism 3. If the movable grass inlet opening 4147 is too wide, the effective length of the movable protective tooth 4146 will be reduced. In an embodiment, the width of the movable grass inlet opening 4147 is 10-25 mm, which ensures the effective length of the movable protective tooth 4146 while avoiding the child's arm from passing through the movable grass inlet opening 4147 to touch the cutting mechanism 3, so that the amount of grass entering the cutting mechanism 3 through the movable grass inlet opening 4147 during the movement of the automatic mower 1 is appropriate, avoiding the phenomenon of too little grass entering, resulting in low work efficiency or grass blockage. The width of the movable protective tooth 4146 is 4-10 mm, which improves the rigidity of the movable protective tooth 4146 while avoiding the width of the movable protective tooth 4146 being too large, causing grass blockage.

[0096] In the up-down direction, the movable guard 41 is movable compared to the bottom shell 101 of the shell 10, and the movable guard wall 414 is also movable compared to the bottom shell of the shell 10, so that when the automatic mower 1 encounters an obstacle 62 within a certain range, the movable guard wall 414 of the movable guard 41 can move upward to avoid the obstacle 62, thereby ensuring better passability of the automatic mower. In this embodiment, under the action of external force applied by the obstacle and the like, the movable guard 41 can move upward as a whole compared to the bottom shell 101, so that the ground clearance of all points on the lower surface of the movable guard wall is increased, so that the automatic mower can pass through the obstacle quickly, greatly improving the passability of the automatic mower as a whole. The movable guard 41 has a lowest state 411 and a highest state 412 within the movable range, the lowest state 411 refers to the lowest position of the movable guard 41 in the up-down direction within the movable space of the movable guard 41 during the movement of the automatic mower, and the highest state 412 refers to the highest position of the movable guard 41 in the up-down direction within the movable space of the movable guard 41 during the movement of the automatic mower. It should be pointed out that the lowest position and the highest position both refer to the range of the movable guard 41 that can be moved by the natural external force or the external force in the same direction as the natural external force during the movement of the automatic mower, for example, the movable guard 41 is subjected to the external force applied by the obstacle or the buoyancy of the grass and the like; and does not include the downward external force applied to the movable guard 41 by human force, which causes the movable guard wall to move downward. As shown in Figure 4 Fig. 3 is a schematic view of the movable guard 41 in the lowest state 411 within the movable range, and Figure 5 Fig. 4 is a schematic view of the movable guard 41 in the highest state 412 within the movable range. When the movable guard 41 is in the lowest state 411, the distance between the lower end 417 of the movable guard wall and the ground is H1, and when the movable guard 41 is in the highest state 412, the distance between the lower end 417 of the movable guard wall and the ground is H2. When the automatic mower 1 moves on a flat lawn, or passes through a lawn whose height is less than or equal to H1, the movable guard 41 is in the lowest state 411. When passing through an obstacle 62 whose height is greater than H1 and less than H2, the movable guard 41 is subjected to the force applied by the obstacle 62, and moves upward to pass through the obstacle 62 quickly.

[0097] In the embodiment, the movable guard 41 includes a free state, which refers to a state of the movable guard 41 when the automatic mower 1 is not subjected to external force at the corresponding cutting height. The free state of the movable guard 41 can be the same at different cutting heights, that is, adjusting the height of the cutting mechanism 3 does not affect the free state of the movable guard 41. Of course, in other embodiments, the free state of the movable guard 41 can also be affected by the height adjustment. However, in order to prevent the child's arm from extending from below the movable guard 41 in the state that the automatic mower 1 is stationary, it is necessary to ensure that the initial distance H0 between the lower end 417 of the movable guard wall and the ground in the free state of the movable guard 41 is always less than M at any cutting height. In the above embodiment, M is set to 38 mm, that is, the initial distance between the lower end 417 of the movable guard wall and the ground is always less than 38 mm. Of course, the above initial distance between the lower end 417 of the movable guard wall and the ground is always less than 38 mm is a preferred value, and in other embodiments, M can also be between 38 mm and 40 mm (including 38 mm and 40 mm), and correspondingly, the distance between the lower end 417 of the movable guard wall and the ground only needs to be always less than M, for example, when M is 40 mm, the distance between the lower end 417 of the movable guard wall and the ground is always less than 40 mm. In the following embodiments, the initial distance between the lower end 417 of the movable guard wall and the ground is always less than 38 mm.

[0098] In an embodiment, the initial distance between the lower end 417 of the movable guard wall and the ground is in the range of 15 mm to 35 mm, so that the distance between the movable guard 41 and the ground can avoid the child's arm from extending, and also will not affect the normal walking of the movable guard wall 414 on the grass due to the too close distance between the movable guard wall 414 and the ground. The distance between the lower end 417 of the movable guard wall and the ground can be further limited to the range of 19 mm to 30 mm. On the one hand, limiting the distance from the ground to be greater than 19 mm increases the distance from the ground to the lower end 417 of the movable guard wall, and improves the passability. On the other hand, limiting the distance from the ground to be less than 30 mm makes the difference between the distance from the ground and the diameter of the child's arm greater than a certain value, leaving a certain safety margin, so that the child's fingers cannot extend in the special working conditions such as the inclination of the automatic mower. Of course, the distance between the lower end 417 of the movable guard wall and the ground can also be set to other ranges, for example, in the range of 15 mm to 25 mm, etc.

[0099] In another embodiment, the initial distance between the lower end 417 of the movable guard wall and the ground is always less than 19 mm, that is, always less than the radius of the child's arm, so that the child's fingers are not easy to extend from below the lower end 417 of the movable guard wall to the cutting mechanism 3.

[0100] Specifically, a safety distance value can be preset, and the safety distance value is less than or equal to M. For example, the safety distance value is 40mm, 38mm, or 19mm, 15-35mm, or 19-30mm or 15-25mm, etc. Regardless of the cutting height of the cutting mechanism 3, or in other words, the cutting mechanism 3 is at any cutting height, the movable protective member 41 is in a free state, and the initial distance H0 of the lower end 417 of the movable protective wall from the ground is always less than the safety distance value. In this embodiment, when the cutting height of the cutting mechanism 3 is adjusted, the cutting mechanism 3 can move relative to the movable protective member 41, so that the initial distance H0 of the lower end 417 of the movable protective wall from the ground is always less than the safety distance value when the movable protective member 41 is in a free state.

[0101] like Figure 4 As shown, when the movable protective element 41 is in its lowest state 411, the distance H1 between the lower end 417 of the movable protective wall and the ground is less than M, so as to prevent the child's arm from extending from the bottom of the movable protective element 41 into the interior of the cutting mechanism 3 and causing accidental injury by the cutting mechanism 3. Figure 4 As shown, when the movable guard 41 is in a free state, that is, when the automatic lawn mower 1 is not subject to external forces, the movable guard 41 is in its lowest position 411. Regardless of the cutting height of the cutting mechanism 3, the movable guard 41 is always in its lowest position 411 when in the free state. That is, when the movable guard 41 is in the free state, the distance H0 between the lower end 417 of the movable guard wall and the ground is the same as the distance H1 between the lower end 417 of the movable guard wall and the ground when the movable guard 41 is in its lowest position 411. For example, when the automatic lawn mower 1 is stationary, moving on grass without resistance, or passing over an obstacle 62 with a height less than or equal to H1, the movable guard 41 is in its lowest position 411. In the lowest position 411, the distance H1 between the lower end 417 of the movable protective wall and the ground is less than M. When an arm with a diameter greater than or equal to M attempts to reach into the automatic lawn mower 1 from under the movable protective element 41, it is blocked by the movable protective wall 414 and cannot reach into the movable protective element 41. In one embodiment, the distance H1 between the lower end 417 of the movable protective wall and the ground is within the range of 15 to 25 mm. This distance from the ground below the movable protective element 41 is sufficient to prevent a child's arm from reaching into the ground while also preventing the movable protective wall 414 from being too close to the ground and hindering their normal walking on the grass. In another embodiment, the distance between the lower end 417 of the movable protective wall and the ground is always less than 19 mm, preventing a child's fingers from reaching into the cutting mechanism 3 from under the lower end 417 of the movable protective wall.

[0102] The movable distance of the movable guard 41 in the up-down direction under the action of the external force is not less than 15 mm, and the specific movable distance can be 15-80 mm, so that the movable guard 41 can avoid most obstacles 62. After the lower end of the movable guard wall moves upward, the distance of the lower end from the ground can be greater than M, so as to avoid limiting the passability of the movable guard wall for blocking the arms of children. In an embodiment, as shown in Figures 4-6 The automatic mower 1 includes an upward guiding mechanism connected with the housing 10 and the movable guard 41, such as a parallel four-bar linkage structure, and the like, which guides the movable guard 41 to move in the up-down direction when the movable guard 41 is acted on by the external force from the outside to the inside. The upward guiding mechanism connected with the movable guard 41 can also be referred to as a guard upward guiding mechanism 45. When the cutting mechanism 3 is at any cutting height, the movable guard 41 can move upward relative to the bottom shell 101 under the action of the external force, so as to increase the distance of the movable guard wall from the ground. When the external force is removed, the movable guard 41 can move downward relative to the bottom shell 101, so as to return the distance of the lower end of the movable guard wall from the ground to the initial distance. Specifically, the movable guard 41 can automatically return to the position in the free state by gravity, or can return to the position in the free state by adding a return mechanism, such as a spring, and the like. Since the guard upward guiding mechanism 45 can drive the movable guard 41 to move in the up-down direction and also drive the movable guard 41 to move in the horizontal direction during rotation, if the displacement in the horizontal direction is too large, the movable guard 41 can interfere with the housing 10 or other components in the horizontal direction, which can reduce the movement of the movable guard 41 in the horizontal direction. In the embodiment, the up-down movable distance of the movable guard 41 is limited to 20-40 mm, so that the guard upward guiding mechanism 45 is selected to rotate near the horizontal direction, so as to reduce the movement range of the movable guard 41 in the horizontal direction. In other embodiments, the movable guard 41 can be connected with the housing 10 by other structures, so as to realize the movement in the up-down direction, such as a four-bar linkage, a two-bar linkage, a single rod, a sliding groove, and the like.

[0103] In the horizontal direction, the minimum distance X between the outermost edge of the movable protective wall 414 and the closest part of the cutting mechanism 3 is greater than 58 mm, and generally, the minimum distance X between the outermost edge of the movable protective wall 414 and the closest part of the cutting mechanism 3 is the minimum distance between the outermost edge of the movable protective wall 414 and the cutting element 30 during the rotation of the cutting element 30 driven by the cutter head. In this embodiment, the minimum distance X is 58-200 mm. Since the fingers are small, the fingers can still be inserted from the bottom of the movable protective member 41 to touch the cutting mechanism 3. In this embodiment, by setting the minimum distance X between the outermost edge of the movable protective wall 414 and the closest part of the cutting mechanism 3 to 58-200 mm, since the length of the fingers of most children is within the range of 58 mm, this embodiment can effectively prevent the fingers of most children from being inserted from the bottom of the movable protective member 41 into the cutting mechanism 3 and being injured by the cutting mechanism 3. In an embodiment, the minimum distance X between the outermost edge of the movable protective wall 414 and the closest part of the cutting mechanism 3 is 63-75 mm, so as to limit the horizontal distance between the movable protective member 41 and the cutting mechanism 3, improve the compactness of the overall structure of the automatic mower 1, and realize the miniaturization and light weight of the automatic mower 1. The outermost edge 413 of the movable protective wall refers to the outermost part of the movable protective wall 414 that can be touched by the user's arm or finger, as shown in Figure 1 The outermost edge 413 of the movable protective wall includes a front outermost edge 4131 located at the front edge of the front movable protective wall 4141, a side outermost edge 4132 located at the outer edge of the side movable protective wall 4142, and a rear outermost edge 4133 located at the rear edge of the rear movable protective wall 4143. The outermost edge 413 of the movable protective wall can be a plane, a curved surface, or an irregular surface, etc.

[0104] As shown in Figure 1 , Figure 4 , Figure 6 and Figure 23 The outermost edge of the movable protective wall 414, i.e., the outermost edge 413 of the movable protective wall, includes an obstacle passing area 4135, and the obstacle passing area 4135 includes an inclined surface extending downward and inward, and the obstacle passing area 4135 is high on the outside and low on the inside. When an obstacle 62 collides with the outermost edge 4131 of the movable protective wall from the outside to the inside, the obstacle 62 generates a force perpendicular to the outermost edge 4131 of the movable protective wall, i.e., an inclined upward force, which generates an upward component force, so as to move the movable protective member 41 upward to quickly pass through the obstacle 62.

[0105] The front outermost edge 4131 of the movable protective wall 414 includes the above-mentioned obstacle passing area 4135, which includes an inclined surface extending downward and outward (from front to back), and in the direction of the automatic mower's advance, the inclined front outermost edge 4131 is higher in front and lower in back. When the automatic mower 1 is automatically walking and encounters an obstacle 62, the movable protective member 41 collides with the obstacle 62, and the obstacle 62 generates a force perpendicular to the front outermost edge 4131 of the movable protective member 41, that is, an inclined upward force, which generates an upward component force, thereby causing the movable protective member 41 to move upward as shown in FIG. 5 to avoid the obstacle 62, thereby improving the passability of the automatic mower 1 while avoiding the child's fingers or arms from touching the cutting mechanism 3. The front outermost edge 4131 can be an inclined plane or a curved surface, etc.

[0106] As shown in FIG. Figure 12 In an embodiment, the rear outermost edge 4133 of the movable protective wall 414 extends downward and outward (from back to front). In the direction of the automatic mower's advance, the inclined rear outermost edge 4133 is lower in front and higher in back. When the automatic mower 1 is retreating and collides with an obstacle 62, the obstacle 62 generates a force perpendicular to the rear outermost edge 4133 of the movable protective member 41, that is, an inclined upward force, which generates an upward component force, thereby causing the movable protective member 41 to move upward to avoid the obstacle 62, thereby improving the passability of the automatic mower 1 while retreating and avoiding the child's fingers or arms from touching the cutting mechanism 3. The rear outermost edge 4133 can be an inclined plane or a curved surface, etc. Similarly, the side outermost edges 4132 of the movable protective wall 414 can also be inclined outward and upward to extend, so that when the automatic mower 1 is turning to the two sides, it quickly passes through the obstacles and improves the passability when turning.

[0107] As shown in FIG. Figure 13 The rear movable protective wall 4143 of the movable protective wall 414 is assembled on the movable connecting wall 415. The automatic mower 1 includes a limiting structure 418 and a restoring structure 416. In this embodiment, the restoring structure 416 is a resilient member, such as a torsional spring, for connecting the movable connecting wall 415 and the rear movable protective wall 4143, and the limiting structure 418 is a limiting portion 4181. In other embodiments, the limiting structure 418 and the restoring structure 416 can be in other forms. In the case of normal movement of the automatic mower 1, the rear movable protective wall 4143 is subjected to the elastic force of the resilient member and the action of the limiting portion 4181, so that it is maintained in the Figure 13 As shown in FIG. Figure 13As shown, when the rear outermost edge 4133 of the rear movable guard wall 4143 collides with the obstacle 62 as the automatic mower 1 moves backward, the rear movable guard wall 4143 is subjected to an upward force and moves upward to a position as shown in Figure 14 As shown, the rear movable guard wall 4143 collides with the housing 10 above, the rear movable guard wall 4143 is subjected to a downward force and rotates clockwise downward, as shown in Figure 15 As shown, the obstacle 62 is pushed forward and quickly passed through to continue moving backward. After the rear movable guard wall 4143 rotates clockwise for a certain distance, it is subjected to a reverse force by the reset structure 416, for example, the restoring force of a torsional spring, and returns counterclockwise to a position as shown in Figure 13 In this embodiment, by designing the rear movable guard wall 4143 to be flip-up type and assembled on the movable connecting wall 415, the rear movable guard wall 4143 is flipped down to avoid the obstacle 62, which reduces the upward movable distance of the rear movable guard wall 4143, reserves more space above the rear movable guard wall 4143 for the housing 10, and makes the overall structure of the automatic mower 1 more compact.

[0108] As shown in Figure 23 As shown in

[0109] F*L1*sin(a+b)=G*L1*cos(a)

[0110] F=G*cos(a) / sin(a+b)

[0111] Wherein, F is the horizontal pushing force of the child arm, L1 is the length of the connecting rod, L2 is the distance that the guard piece is allowed to float upward, G is the gravity of the guard piece, and b is the angle of inclination inward from the vertical plane where the outermost end is located. In this embodiment, the movable guard piece 41 is 30mm from the ground and is allowed to move upward by 20mm, i.e., the lower end 417 of the movable guard piece is between 30mm and 50mm from the ground. In this example, the length of the four connecting rods is selected to be 110mm. When the movable guard piece 41 is in the highest state 412, the four connecting rods remain in a horizontal state. In this embodiment, when F is the test force of the child arm 5N and G=0.93N, the weight of the movable guard piece is greater than 93g, and the test force of the child arm cannot lift the guard piece.

[0112] From the above calculation, it can be found that the smaller b is, i.e., the closer the region where the outermost edge 413 of the movable guard piece contacts the test arm 61 is to the vertical, the longer the four connecting rods are, the heavier the movable guard piece 41 is, the smaller the distance that the lower end 417 of the movable guard wall moves upward is, and the more difficult the movable guard piece 41 is to be lifted.

[0113] In this embodiment, asFigure 23 As shown, the outermost edge 413 of the movable protective wall also includes a safety locking area 4136 for preventing the child's arm from lifting the movable protective wall 414. A safety external force value F1 is preset, and the safety external force value is not less than the test force 5N of the child's arm. When the force from the outside to the inside acts on the safety locking area, the movable protective wall 414 cannot move upward. The safety locking area 4136 is set in the area where the outermost edge 413 of the movable protective part contacts the test arm 61 to prevent the lower end 417 of the movable protective part from moving upward under the action of the child's arm test force. The lower end of the safety locking area is less than M from the ground. Even if the movable protective part is forced to move upward, because the lower end of the safety locking area is less than M from the ground, at the highest position where the child's arm can lift the movable protective part, there must be a section of the safety locking area that is against the child's arm to ensure that the child's arm cannot extend into the cutting mechanism. Since the area where the outermost edge 413 of the movable protective part contacts the test arm 61 is generally within the range of M (including M) between the movable protective wall 414 and the ground, a safety locking area 4136 is set at least within the range of M between the movable protective wall 414 and the ground. Of course, depending on the situation, the above-mentioned safety locking area 41 may also be set where the distance between the movable protective wall 414 and the ground exceeds M to prevent the child's arm from tilting and contacting the above-mentioned movable protective wall 414.

[0114] like Figure 23As shown, safety lock zone 4136 is located outside of the downward extension of the obstacle passage zone on the same radial direction. Safety lock zone 4136 includes an inclined surface and / or a vertical surface. Specifically, safety lock zone 4136 includes an inclined surface and / or a vertical surface extending downward from the outside to the inside and / or an inclined surface extending upward from the outside to the inside. These inclined surfaces and vertical surfaces may be flat, curved, irregular, or the like. When safety lock zone 4136 is an inclined surface extending downward from the outside to the inside, the angle of inclination of the inclined surface of safety lock zone 4136 from the vertical plane at its outermost end may be less than 15 degrees. In one embodiment, the angle of inclination of the inclined surface of safety lock zone 4136 from the vertical plane at its outermost end may be less than 3 degrees. When the safety locking zone 4136 is an inclined surface that tilts downward from the outside to the inside, the angle at which the inclined surface of the safety locking zone 4136 tilts inward from the vertical plane where its outermost end is located is smaller than the angle at which the inclined surface of the obstacle passing zone 4135 tilts inward from the vertical plane where its outermost end is located. The smaller the angle at which the inclined surface of the safety locking zone 4136 tilts inward from the vertical plane where its outermost end is located, the less likely the movable protective wall will move upward when a preset safety external force value acts on the safety locking zone 4136. In one embodiment, the safety locking zone 4136 can be selected as a vertical surface, and only the demolding angle is retained. The greater the angle at which the inclined surface of the obstacle passing zone 4135 tilts inward from the vertical plane where its outermost end is located, the easier it is for the movable protective wall 414 to be lifted when the obstacle 62 hits the movable protective wall 414, and thus the easier it is to avoid obstacles. In one embodiment, as Figure 32 As shown, in the up and down directions of the automatic lawn mower 1, the movable protective wall 414 includes a main movable part 401 located at its upper end and a locking part 402 formed by the autonomous movable part 401 extending downward. The outermost edge of the main movable part 401 is provided with an obstacle passing area 4135, and the outermost edge of the locking part 402 is provided with a safety locking area 4136. In this embodiment, the movable protective wall having both the obstacle passing area 4135 and the safety locking area 4136 is taken as an example. In other embodiments, the movable protective wall may also have only one of the obstacle passing area 4135 and the safety locking area 4136. In order to achieve better passability, the distance from the lower end of the locking part 402 to the ground is preferably in the range of M / 2 to M, where M is between 38mm-40mm. For example, when the distance from the locking part 402 to the ground is 19mm-40mm, at this time, the distance from the lower end of the locking part 402 to the ground is greater than the radius of the test arm 61. If Figure 32 As shown, when the outermost edge of the locking portion 402 is a continuous surface or a section of a long continuous surface, when the test arm 61 strikes the locking portion 402 in a non-linear direction, Figure 32 When the lower end of the movable protective wall 414 is Figure 33 and Figure 34As shown, the transition surface between the front end surface of the test arm 61 and its side surface abuts against the lower end of the continuous surface of the outermost edge of the locking portion 402. At this time, the force-bearing surface is the transition surface, and as shown in FIG. Figure 34 As shown, the force point on the test arm 61 is located above the horizontal plane where the center line of the test arm is located, and the test wall 61 and the movable protective wall 414 are in contact with each other to produce the following Figure 34 The force F shown can be decomposed into a vertical component F1 and a horizontal component F2. The vertical component F1 will push the floating protective wall upward, causing the movable protective wall to increase its distance from the ground. When the distance is greater than the diameter of the test arm 61, the test arm 61 can extend into the interior of the movable protective wall 414, and then extend into the cutting mechanism and be accidentally injured.

[0115] In order to avoid the risk of the test arm 61 hitting the movable protective wall 414 along the non-linear direction, in one embodiment, Figure 35 As shown, the locking portion 402 at the lower end of the movable protective wall 41 includes a plurality of blocking protrusions 4021 circumferentially spaced apart at the bottom of the movable protective wall 414 and a transition wall 4022 for connecting the main movable portion 401 and the blocking protrusion 4021, wherein the outermost edges of the blocking protrusion 4021 and the transition portion 4022 are provided with a safety locking area 4136 to prevent the movable protective wall from being lifted when a child's arm is extended from the locking portion 402. In some embodiments, if the highest point of the blocking protrusion 4021 is sufficiently far from the ground, the transition portion may not be provided. For example, since the diameter of a general child's arm does not exceed M, when the highest point of the blocking protrusion 4021 is not less than M from the ground, the transition portion may not be provided, that is, the blocking protrusion 4021 is directly extended downward from the bottom of the main movable portion 401. As shown in FIG. Figure 35 As shown, the transition portion 4022 connected to the top of the blocking protrusion 4021 can be called an upper blocking portion. When there is no transition portion 4022 above the blocking protrusion 4021 and the main movable portion 401 is directly connected to the top of the blocking protrusion 4021, the main movable portion 401 can also be called an upper blocking portion.

[0116] like Figures 35-45 As shown, when the distance between the lower end of the locking portion 402 and the ground is within the range of M / 2 to M, that is, when the distance between the lower end of the blocking protrusion 4021 and the ground is greater than M / 2, for example, when the distance between the blocking protrusion 4021 and the ground is 19-40 mm, or when the distance between the lower end of the locking portion 402 and the ground is greater than the radius of the test arm 61, when the test arm 61 strikes the test arm 61 in the non-normal direction, Figure 35 When the lower end of the movable protective wall 414 is shown, the front end surface of the test arm 61 abuts against the blocking protrusion 4021, and the force applied thereto is as follows: Figure 37 As shown, the force-bearing surface is always the front end surface of the test arm 61, which only produces Figure 37The force F' on the horizontal plane shown does not generate an upward force, which can prevent the movable protective wall 414 from moving upward when subjected to the force applied by the test arm 61 in the non-normal direction, causing the test arm 61 to extend into the cutting mechanism and thus cause danger.

[0117] In order to ensure that when the test arm 61 strikes the lower end of the movable protective wall 414 in any normal direction, the force-bearing surface is the front end of the test arm 61, thereby avoiding the generation of an upward force component, the distance S between any two adjacent blocking protrusions 4021 and the height h of the blocking protrusions 4021 must be greater than zero. However, to prevent the test arm 61 from extending into the gap between two adjacent blocking protrusions 4021 in the normal direction, the distance S is ≤ the test arm diameter. Since the test arm diameter is less than or equal to 40 mm, in this embodiment, the range of S is limited to: 0 <S≤40mm;优选的,S范围为:3≤S≤25mm,以避免两相邻的阻挡凸起4021之间间隙过小,导致测试臂沿非法线方向侵入产生向上的力,或者间隙过大,测试臂61能伸入间隙内。同时,如果阻挡凸起4021过大,则会导致通过性不佳,因此,阻挡凸起4021的高度h限定为0<h≤80mm,优选,3≤h ≤20mm。

[0118] At the same time, in order to prevent the test arm 61 from hitting in the non-linear direction, the transition surface of the test arm 61 abuts against the outermost edge of the blocking protrusion 4021, and the width M of the blocking protrusion 4021 is limited to 0 <M≤40mm,优选0<M ≤20mm,阻挡凸起4021的最外缘与上阻挡部的最外缘不重叠,也即,阻挡凸起4021的最外缘与过渡部4022的最外缘不重叠,阻挡凸起4021不与上阻挡部最外缘重叠的部分,位于上阻挡部最外缘对应部分的内侧,也即,如 Figure 35 As shown, the portion of the outermost edge of the blocking protrusion 4021 that does not overlap with the outermost edge of the transition portion 4022 is located inside the portion corresponding to the outermost edge of the transition portion 4022. For example, when the outermost edges of the upper blocking portion, i.e., the transition portion 4022, and the blocking protrusion 4021 are both curved surfaces, the curvature of the blocking protrusion 4021 is greater than the curvature of the upper blocking portion at its corresponding position, i.e., the curvature of the transition portion 4022 at its corresponding position is greater. The curvature radius R of the blocking protrusion 4021 can be set to 0. <R≤20mm,优选0<R≤10mm。本实施例中,阻挡凸起4021的最外缘为半圆弧面,在其实施例中,阻挡凸起4021的最外缘也可为其他圆弧面,或者为宽度比较小的直面等等。

[0119] In this embodiment, the ground clearance of the lower end of the locking portion 402, that is, the lower end of the blocking protrusion 4021, is set to be within the range of M / 2 to M, for example, the ground clearance of the lower end of the locking portion 402 is 19mm-40mm, thereby enhancing the passability of the automatic lawn mower. At the same time, the blocking protrusion 4021 is provided to prevent children's arms from entering the movable protective wall in a non-illegal direction, thereby ensuring the safety of children while improving the passability.

[0120] In another embodiment, the distance from the lower end of the locking portion 402 to the ground can be limited to within the radius of the child's arm to avoid the upward force generated when the child's arm collides with the locking portion 402 in a non-illegal direction. Specifically, when the cutting mechanism is at any cutting height, the initial distance of the movable protective wall 41 from the ground is always less than or equal to M / 2, that is, the initial distance from the lower end of the locking portion 402 to the ground can be limited to less than or equal to M / 2, for example, the distance from the lower end of the locking portion 402 to the ground is less than or equal to 19 mm. At this time, as shown in FIG38, when the test arm 61 collides with the locking portion 402 in a non-illegal direction, the lower end of the locking portion 402 can be limited to less than or equal to M / 2. Figure 32 When the lower end of the movable protective wall 414 is shown, Figure 39 As shown, the force point on the test arm 61 is always on the horizontal plane where the center line of the test wall 61 is located. At this time, only the force F'' on the horizontal plane is generated, and no upward component force is generated. Therefore, at this time, the child's arm can be prevented from extending into the movable protective wall 414 along the illegal direction.

[0121] With Figure 35 When the automatic lawn mower with the locking portion 402 shown encounters dense grass, the blocking protrusion 4021 will be inserted into the grass. Because the grass is overlapped, as the automatic lawn mower moves forward, the blocking protrusion 4021 will pull the grass apart. In addition, the overlapping grass will bring resistance to the forward movement of the automatic lawn mower, reducing the passability of the automatic lawn mower.

[0122] In order to further improve the passability of dense grass, in one embodiment, Figure 40 As shown, the locking portion 402 at the lower end of the movable protective wall 41 further includes a connecting protrusion 4023 extending in the vertical direction for connecting at least two adjacent blocking protrusions 4021. The connecting protrusion 4023 is partially recessed inward so that the connecting protrusion 4023 and the two adjacent blocking protrusions 4021 connected thereto form a structure with an outer space and an inner closed structure. Figures 41-43 As shown, when the automatic lawn mower encounters grass while moving forward, the blocking protrusion 4021 is inserted into the grass, but as the automatic lawn mower moves forward, as shown in FIG. Figure 42 As shown, the grass is pressed down by the connecting protrusion 4023, and as the automatic lawn mower moves further forward, as shown in FIG. Figure 43The crushed grass stands up again and enters the cutting area, and is then cut by the cutting mechanism. In this embodiment, the connection protrusion 4023 is arranged to effectively prevent the blocking protrusion from being inserted into the grass, thereby increasing the running resistance, and even breaking or damaging the grass. The circumferentially continuous structure formed by the connection protrusion and the blocking protrusion together can also be referred to as the grass crushing end face 406. In other embodiments, a circumferentially continuous grass crushing end face 406 can also be arranged directly at the lower end of the movable protective wall or the lower end of the mechanism protective wall. The grass crushing end face 406 only needs to ensure that the lower end of the movable protective wall has no opening in the inner-outer direction, and it can be, for example Figure 40 The sawtooth-shaped structure shown can also be Figure 45 The structure shown can also be Figure 32 The structure shown, the grass crushing end face 406 directly crushes the grass, thereby avoiding large running resistance, and even breaking or damaging the grass.

[0123] As shown in Figure 44 In order to ensure safety protection and achieve better passability, in the direction from outside to inside, the distance d between the outermost side of the blocking protrusion 4021 and the innermost side of the connection protrusion 4023, the height h of the blocking protrusion 4021, the distance S between two adjacent blocking protrusions 4021, and the width M of the blocking protrusion 4021, cannot be too large or too small; if d is too large, or h is too large, or S is too large, the more the amount of grass inserted into the gap between the two blocking protrusions or the movement distance of the grass in the gap, the larger the running resistance, and the more likely the grass is damaged; if d is too small, or h is too small, or S is too small, or M is too large, the child's arm is more likely to stretch into the movable protective wall 414, which brings safety risks; M also cannot be too small, and if M is too small, the strength of the blocking protrusion 4021 will also be reduced. For the above reasons, in this embodiment, 1mm≤d≤100mm, preferably 3mm≤d≤20mm; 0mm<h≤80mm, preferably 3mm≤h≤20mm; 0<S≤40mm, preferably 3≤S≤25mm; 0<m≤40mm, preferably 0<m≤20mm, so as to ensure that the child's arm cannot stretch into the movable protective wall, and improve the passability of the automatic mower.

[0124] As shown in Figure 40 In this embodiment, the connection protrusion 4023 is a V-shaped structure connecting two adjacent blocking protrusions 4021, and the connection protrusion 4023 and the blocking protrusion 4021 are connected in a sawtooth shape. This design can reduce the volume of the groove formed by the connection protrusion 4023 and the blocking protrusion 4021 towards the outside of the automatic mower, reduce the amount of grass inserted into the groove, reduce the running resistance, and reduce the risk of grass being damaged, while ensuring the distance S between the two adjacent blocking protrusions 4021, the distance d between the outermost side of the blocking protrusion 4021 and the innermost side of the connection protrusion 4023, the height h of the blocking protrusion 4021, and the width M of the blocking protrusion 4021.

[0125] Of course, in other embodiments, the connecting protrusion 4023 can also be arc-shaped structure close to V-shaped, the connecting protrusion 4023 and the blocking protrusion 4021 are connected in a wave shape, or as shown in FIG. 45, the connecting protrusion 4023 can also be N-shaped structure, the connecting protrusion 4023 and the blocking protrusion 4021 are connected in a continuous N-shaped structure, etc. In the embodiment, in order to avoid the child's arm being cut by the cutting element 32 when the arm is accidentally rolled by the automatic mower 1. It is necessary to ensure that the lower end of the protection assembly 4 is always lower than the cutting element 30 during the movement of the movable protection piece 41, that is, the movable protection wall lower end 417 moves in the up-down direction. In order to achieve the above purpose, the lower end of the protection assembly 4 can be always lower than the lowest point of the cutting element 30 by increasing the above-mentioned mechanism protection piece 42. The relative position relationship between the movable protection piece 41 and the cutting mechanism 3 during the movement of the movable protection piece 41 can also be limited, so that the movable protection wall lower end 417 is always lower than the lowest point of the cutting element 30 during the movement of the movable protection wall lower end 417 in the up-down direction under the action of external force.

[0126] Taking the case of increasing the aforementioned mechanism protection piece 42 to achieve the lower end of the protection assembly 4 being always lower than the lowest point of the cutting element 30 in the presence of the movable protection piece 41. The protection assembly 4 includes the movable protection piece 41 and the mechanism protection piece 42, wherein the mechanism protection piece 42 is fixed relative to the cutting mechanism 3, for example, when the cutting mechanism 3 moves relative to the shell, the mechanism protection piece 42 moves together, when the cutting mechanism 2 does not move relative to the shell, the mechanism protection piece 42 also does not move together. In the non-height adjustment state, the cutting mechanism 3 can be arranged to be able to move relative to the shell, or can be arranged to be unable to move relative to the shell. Regardless of how the cutting mechanism 2 and the movable protection piece 41 move, or how they move relative to each other, because the mechanism protection piece 42 is always fixed relative to the cutting mechanism 2, and the lower end of the mechanism protection piece 42 is always lower than the lowest point of the cutting element 30, therefore, even if the test arm 61 passes through the movable protection piece 41, it will be blocked by the mechanism protection piece 42; even if the lower end of the mechanism protection piece 42 is higher than the test arm 61, the test arm 61 can only be located below the cutting element 30, and cannot touch the cutting element 30. Therefore, the safety of the child's arm can be ensured. In the embodiment, any of the aforementioned or subsequent embodiments with the mechanism protection piece 42 can be directly quoted, in which the structure is no longer described in detail. Hereinafter, taking the case of limiting the relative position relationship between the movable protection piece 41 and the cutting mechanism 3 during the movement of the movable protection piece 41 to achieve the lower end of the protection assembly 4 being always lower than the cutting element 30 in the presence of the movable protection piece 41.

[0127] For example, the lower end of the movable guard 41 can always be lower than the lowest point 30 of the cutting element during the whole movement by limiting the movable guard 41 to be in the two extreme states of the lowest state 411 and the highest state 412, in which the lower end of the movable guard is always lower than the lowest point 30 of the cutting element.

[0128] When the cutting height of the automatic mower 2 is adjusted to the lowest position, and the movable guard 41 is in the lowest state 411, the lower end 417 of the movable guard wall of the movable guard 41 is lower than the lowest point 30 of the cutting element in the up-down direction, so that the lower end 417 of the movable guard wall of the movable guard 41 is always lower than the lowest point 30 of the cutting element when the movable guard 41 is in the lowest state, regardless of the adjustment of the cutting height of the automatic mower 2, to prevent the arms of children from being crushed by the automatic mower 1. Specifically, the distance between the lower end 417 of the movable guard wall and the lowest point 30 of the cutting element is 2-30 mm, to ensure that the fingers and arms of children cannot touch the cutting mechanism 3 around the movable guard.

[0129] When the cutting mechanism is at any cutting height, during the movement of the automatic mower 1, when the movable guard 41 is in the highest state 412, i.e. the movable guard wall is moved upward to the highest point of its movable range by external force, the lower end 417 of the movable guard wall is lower than the lowest point 30 of the cutting element, so that the lower end 417 of the movable guard wall of the movable guard 41 is always lower than the lowest point 30 of the cutting element when the movable guard 41 is subjected to an inward force from the outside. To achieve the above purpose, the following technical solutions can be used.

[0130] In one embodiment, at at least one cutting height, during the movement of the automatic lawn mower 1, when the movable guard 41 is moved vertically by an external force, the cutting mechanism 3 moves synchronously with the movable guard 41 in the vertical direction, ensuring that the lower end 417 of the movable guard wall remains below the lowest point 30 of the cutting element. The movable guard 41 is interconnected with the cutting mechanism 3. During the movement of the automatic lawn mower 1, when the movable guard 41 is forced to move upward, the cutting mechanism 3 moves upward with it. When the movable guard 41 moves downward, the cutting mechanism 3 also moves downward with it. In this embodiment, the interconnection between the cutting mechanism 3 and the movable guard 41 ensures that the vertical movement of the movable guard 41 drives the cutting mechanism 3 to move synchronously with it. During the vertical movement of the cutting mechanism 3 with the movable guard 41, the cutting mechanism 3 can be fixed relative to the movable guard 41 or can undergo a certain relative movement. For example, in one embodiment, during the movement of the automatic lawn mower 1, the cutting mechanism 3 and the movable guard 41 are relatively fixed in the vertical direction, that is, their relative positions in the vertical direction do not change. Because the cutting mechanism 3 moves along with the movable guard 41, their relative positions in the vertical direction do not change. As long as the lower end 417 of the movable guard wall is lower than the lowest point 30 of the cutting element when the movable guard 41 is in its lowest position, the lower end 417 of the movable guard wall remains lower than the lowest point 30 of the cutting element throughout the entire movement of the movable guard 41. In another embodiment, in the up and down directions, the cutting mechanism 3 moves together with the movable protective member 41, and the cutting mechanism 3 can also move relative to the movable protective member 41. The automatic lawn mower 1 also includes a movable adjustment mechanism (not shown) for adjusting the movement of the cutting mechanism 3 compared to the movable protective member 41. For example, the movable adjustment mechanism is an adjustment mechanism that automatically adjusts the cutting mechanism 3 to move upward. For example, when the movable protective member 41 is moved upward by 20 mm by an external force, and the movable adjustment mechanism controls the cutting mechanism 3 to move upward by 10 mm compared to the movable protective member 41, then during the whole process, the movable protective member 41 moves upward by 20 mm compared to the shell 10, and the cutting mechanism 3 moves upward by 30 mm compared to the shell 10.

[0131] In the process of adjusting the height of the cutting mechanism 3, the cutting mechanism 3 and the movable guard 41 are relatively movable in the up-down direction, so that the lower end 417 of the movable guard wall does not increase indefinitely with the increase of the cutting mechanism 3, thereby ensuring that the distance H0 between the lower end 417 of the movable guard wall and the ground is always less than the preset safety distance value, for example, always less than 38mm. In the embodiment, the cutting mechanism 3 and the movable guard 41 are relatively movable in the up-down direction by moving the cutting mechanism 3 in the up-down direction relative to the ground, and the movable guard 41 is not moved in the up-down direction relative to the ground. Of course, in other embodiments, the cutting mechanism 3 and the movable guard 41 can also be moved in the up-down direction, but the two are not moved synchronously when they are raised, for example, the movable guard 41 moves a distance less than the distance moved by the cutting mechanism 3.

[0132] In another embodiment, at least one cutting height, when the movable guard wall 414 is moved in the up-down direction by an external force, the lower end of the movable guard wall 414 can be moved in the up-down direction relative to the cutting mechanism 3. As shown in FIG. 6, the movable guard wall 414 is connected to the cutting mechanism 3 by a connecting rod 412, and the connecting rod 412 is connected to the cutting mechanism 3 by a connecting rod 413. When the cutting mechanism 3 is raised, the connecting rod 413 is also raised, and the connecting rod 412 is also raised, so that the movable guard wall 414 is also raised. When the cutting mechanism 3 is lowered, the connecting rod 413 is also lowered, and the connecting rod 412 is also lowered, so that the movable guard wall 414 is also lowered. Figure 11As shown, the automatic mower 1 comprises a limiting mechanism 9 for limiting the relative position of the movable guard 4 and the cutting mechanism 3, which is used to limit the relative movement degree of the movable guard 4 and the cutting mechanism 3 in the up-down direction. The limiting mechanism 9 comprises a cutting limiting part 39 and a guard limiting part 419 which can limit each other, the cutting limiting part 39 is fixed relative to the cutting mechanism 3 in the up-down direction, the guard limiting part 419 is fixed relative to the movable guard 41 in the up-down direction, and when the cutting limiting part 39 and the movable guard 41 limit each other, the cutting limiting part 39 is above the guard limiting part 419. Specifically, the limiting mechanism 9 comprises the guard limiting part 419 arranged on the movable guard 4 and the cutting limiting part 39 arranged on the cutting mechanism 3. The cutting limiting part 39 is above the guard limiting part 419, and when the movable guard wall 414 moves upward under the action of external force, the movable guard wall 414 can move relative to the cutting mechanism 3 in the up-down direction. When the movable guard wall 414 moves upward, the guard limiting part 419 moves upward, and when the guard limiting part 419 moves to abut against the cutting limiting part 39, it is blocked by the cutting limiting part 39. The upward movement of the movable guard 4 is limited by the cutting mechanism 3, and the movable guard 4 cannot continue to move upward relative to the cutting mechanism 3, thereby limiting the range of upward movement of the movable guard 4 relative to the cutting mechanism 3, so that the lower end 417 of the movable guard wall is always lower than the lowest point 30 of the cutting element during the upward movement of the movable guard 4. When the movable guard 4 is in the lowest state and the cutting mechanism 3 is adjusted to the lowest cutting height, the distance between the lower end 417 of the movable guard wall and the lowest point 30 of the cutting element in the up-down direction is greater than the distance between the guard limiting part 419 and the cutting limiting part 39, so that when the movable guard 4 moves to the highest state, the lower end 417 of the movable guard wall is still lower than the lowest point 30 of the cutting element, and during the entire movable process, the lower end 417 of the movable guard wall is always lower than the lowest point 30 of the cutting element. When the cutting mechanism 3 is adjusted upward, as the cutting mechanism 3 is adjusted upward, the distance between the guard limiting part 419 and the cutting limiting part 39 is increased synchronously with the distance between the lower end 417 of the movable guard wall and the lowest point 30 of the cutting element when the movable guard 4 is in the lowest state, so no matter how high the cutting mechanism 3 is adjusted, the lower end 417 of the movable guard wall is always lower than the lowest point 30 of the cutting element in the up-down direction. In other embodiments, the lower end 417 of the movable guard wall can always be lower than the lowest point 30 of the cutting element during the movement of the movable guard 4 can also be achieved by other means, which will not be repeated in this application. In this embodiment, the above-mentioned implementation of the preset grass safety lifting height can also be used to avoid the situation that when the automatic mower 1 is stationary on the grass, the movable guard wall 414 is lifted to the grass safety lifting height by the grass, and the arm is inserted into the cutting mechanism 3 from below the movable guard wall 414. The details of this embodiment will not be repeated.

[0133] In one embodiment of the present embodiment, the cutting mechanism 3 is immovable in the up-down direction relative to the ground, and when the movable guard 4 is upwardly moved and is limited by the cutting mechanism 3, the movable guard 4 cannot be upwardly moved any more because the cutting mechanism 3 cannot be upwardly moved.

[0134] In another embodiment of the present embodiment, as shown in FIG. 6, the cutting mechanism 3 can also be movable in the up-down direction relative to the ground, and the cutting mechanism 3 and the movable guard 41 can be relatively independently movable in the up-down direction. The automatic mower 1 comprises a guard upward guiding mechanism 45 for connecting the movable guard 41 and the housing 10, and a cutting upward guiding mechanism 35 for connecting the cutting mechanism 3 and the housing 10, and the guard upward guiding mechanism 45 is independent of the cutting upward guiding mechanism 35, so that the cutting mechanism 3 and the movable guard 41 can be relatively independently movable in the up-down direction. Figures 24-2 As shown in FIG. 5, in the non-height-adjusting state, when the cutting mechanism is subjected to an external force, the cutting mechanism can be movable in the up-down direction relative to the ground, and in at least one cutting height, the lower end of the movable guard wall 414 can be movable in the up-down direction relative to the cutting mechanism 3 during the process that the movable guard wall 414 is subjected to an external force and is moved in the up-down direction. In the present embodiment, the movable guard wall 414 can be movable in the up-down direction relative to the cutting mechanism 3 in any cutting height, and in other embodiments, the movable guard wall 414 and the cutting mechanism 3 can be relatively movable only in some gears. In the present embodiment, the movable guard wall 414 is first upwardly moved alone until it is limited by the cutting mechanism 3, and then the movable guard wall 414 and the cutting mechanism 3 are upwardly moved together as shown in FIGS. 25 and 26. The resistance of the movable guard wall 414 when it is upwardly moved alone is smaller than the resistance when the movable guard wall 414 and the cutting mechanism 3 are upwardly moved together.

[0135] Figures 24-2 As shown in FIG. 5, in the non-height-adjusting state, when the cutting mechanism is subjected to an external force, the cutting mechanism can be movable in the up-down direction relative to the ground, and in at least one cutting height, the lower end of the movable guard wall 414 can be movable in the up-down direction relative to the cutting mechanism 3 during the process that the movable guard wall 414 is subjected to an external force and is moved in the up-down direction. In the present embodiment, the movable guard wall 414 can be movable in the up-down direction relative to the cutting mechanism 3 in any cutting height, and in other embodiments, the movable guard wall 414 and the cutting mechanism 3 can be relatively movable only in some gears. In the present embodiment, the movable guard wall 414 is first upwardly moved alone until it is limited by the cutting mechanism 3, and then the movable guard wall 414 and the cutting mechanism 3 are upwardly moved together as shown in FIGS. 25 and 26. The resistance of the movable guard wall 414 when it is upwardly moved alone is smaller than the resistance when the movable guard wall 414 and the cutting mechanism 3 are upwardly moved together. Figures 24-2 ​5, during the forward movement of the automatic mower 1, the movable guard wall 414 is subjected to the upward grass lifting force of the grass, which is greater than the resistance of the upward movement of the movable guard wall 414 alone, and the movable guard wall 414 can move upward. However, the grass lifting force is less than the resistance of the upward movement of the movable guard wall 414 together with the cutting mechanism 3 after being limited by the cutting mechanism 3, so when the movable guard wall 414 moves upward to be limited by the cutting mechanism 3, the grass lifting force of the grass on the movable guard wall 414 cannot lift the movable guard wall 414 upward together with the cutting mechanism 3, at this time, the movable guard wall 414 maintains the state to perform the cutting task, so that the distance between the lower end 417 of the movable guard wall and the lowest point 30 of the cutting element is maintained within a certain range during cutting, avoiding the situation that the distance between the lower end 417 of the movable guard wall and the ground is too close, and the distance between the lower end 417 of the movable guard wall and the lowest point 30 of the cutting element is too far, and the grass pressed by the lower end 417 of the movable guard wall cannot be cut. In this embodiment, by ensuring the distance between the lower end 417 of the movable guard wall and the lowest point 30 of the cutting element, on the one hand, the distance between the lower end 417 of the movable guard wall and the ground is increased, and the possibility of pressing the grass is reduced, and on the other hand, even if the lower end 417 of the movable guard wall presses the grass, the distance between the lower end 417 of the movable guard wall and the lowest point 30 of the cutting element is reduced, and the grass pressed by the lower end 417 of the movable guard wall can still be cut, thereby greatly improving the cutting quality.

[0136] As shown in FIG. 25, when the automatic mower 1 encounters an obstacle 62 during movement, the upward obstacle lifting force generated by the external force of the obstacle 62 on the movable guard wall 414 is greater than the resistance of the upward movement of the movable guard wall 414 together with the cutting mechanism 3 after being limited by the cutting mechanism 3, so when the movable guard wall 414 moves upward to be limited by the cutting mechanism 3, under the action of the obstacle 62, as shown in FIG. 26, the movable guard wall 414 moves upward together with the cutting mechanism 3 to pass through the obstacle 62.

[0137] In the above embodiment, when the movable guard wall 414 is subjected to the upward force from below, the lower end of the movable guard wall 414 moves upward compared to the bottom shell. When the automatic mower moves on the lawn, the movable guard wall 414 is subjected to the upward buoyant force of the grass on it, and the movable guard wall 414 can move upward, and the lower end of the movable guard wall 414 generates upward displacement to reduce the movement resistance of the grass on it and improve the grass passing property. In the above embodiment, the movable guard wall 414 is in the form of moving in the up-down direction as a whole compared to the bottom shell, and in other embodiments, the movable guard wall 414 can also be in a compressible structure as shown in FIG. 27, so that the lower end of the movable guard wall 414 can move upward when subjected to the upward force from below to improve the grass passing property. Of course, in other embodiments, the movable guard member can also be in other forms, which will not be listed one by one. Figures 19-20 ​

[0138] In another embodiment of the present embodiment, as shown in Figures 27-29 The movable guard 41 includes an upper guard 43 and a lower guard 44, which can be moved in the up-down direction by the lower guard 44 compared to the upper guard 43, so that the distance between the lower end of the lower guard 43 and the ground changes, and the lower end of the lower guard 43 is movable in the up-down direction compared to the cutting mechanism 3. The upper guard 43 and the lower guard 44 respectively include an upper guard wall 434 and a lower guard wall 444, which together form a movable guard wall 414. The lower end of the lower guard wall 444 is the lower end of the movable guard wall 417. The lowest state 411 of the movable guard 41 is that the lower guard 44 is in the lowest position in the space movable in the up-down direction, and the highest state 412 is that the lower guard 44 is in the highest position in the space movable in the up-down direction. The guard limiting portion 419 on the movable guard 41 is provided on the lower guard 44, and the cutting mechanism 3 is provided with a cutting limiting portion 39 for limiting the guard limiting portion 419.

[0139] When adjusting the cutting height of the cutting mechanism 3, the lower guard wall 444 and the cutting mechanism 3 can move relative to each other in the up-down direction, so that the distance between the lower end of the lower guard wall 444, i.e. the lower end of the movable guard wall 417, and the ground is always less than M. For example, the lower guard wall 444 and the cutting mechanism 3 can move relative to each other in the up-down direction by moving the upper guard wall 434 and the cutting mechanism 3 relative to each other in the up-down direction, while the lower guard wall 444 and the upper guard wall 434 do not move relative to each other in the up-down direction. When the movable guard 41 is moved upward by an external force, the lower guard wall 444 moves upward relative to the ground, and at the same time, the lower guard wall 444 moves upward relative to the upper guard wall 434, first moves to be limited by the cutting mechanism 3, and then moves upward together with the upper guard wall 434 and the cutting mechanism 3.

[0140] The resistance of the lower guard wall 444 moving upward alone is less than the resistance of the lower guard wall 444, the upper guard wall 434 and the cutting mechanism 3 moving upward together after being limited by each other.

[0141] As shown in Figure 28 and Figure 29 When the automatic mower 1 encounters an obstacle 62 during movement, the upward obstacle lifting force generated by the external force of the obstacle 62 on the lower guard wall 444 is greater than the resistance of the lower guard wall 444, the upper guard wall 434 and the cutting mechanism 3 moving upward together after being limited by each other, so when the lower guard wall 444 moves upward to be limited by the upper guard wall 434 and the cutting mechanism 3, under the action of the obstacle 62, as shown in Figure 29As shown, the lower guard wall 444 moves upward together with the upper guard wall 434 and the cutting mechanism 3 to pass the obstacle 62.

[0142] In the embodiment, the movable guard 4 and the cutting mechanism 3 can be independently moved in the up-down direction. In the embodiment, the movable guard 4 and the cutting mechanism 3 are provided with the limiting mechanism 9 for limiting each other. The preset grass safety lifting height is implemented by the following method. When the lower end of the lower guard wall 444 is away from the ground by a distance greater than the preset grass safety lifting height during the upward movement of the lower guard wall 444 under the external force, the resistance of the upward movement of the lower guard wall 444 is greater than that when the distance between the lower end of the lower guard wall 444 and the ground is not greater than the preset grass safety lifting height. When the distance between the lower end of the lower guard wall 444 and the ground is greater than the preset grass safety lifting height and the lower guard wall 444 has not been limited by the cutting mechanism 3, the resistance of the upward movement of the lower guard wall 444 is greater than that when the distance between the lower end of the lower guard wall 444 and the ground is not greater than the preset grass safety lifting height and the lower guard wall 444 has not been limited by the cutting mechanism 3, and is less than that when the lower guard wall 444, the upper guard wall 434 and the cutting mechanism 3 are limited and move upward together.

[0143] In another embodiment, the movable guard 4 and the cutting mechanism 3 can also be automatically movable. The automatic mower 1 further comprises a detection module for detecting whether the movable guard 4 and the cutting mechanism 3 need to be movable, and a movable control module for automatically controlling the movable guard 4 and the cutting mechanism 3 to be movable according to the detection result of the detection module. The detection module can be a visual sensor, an ultrasonic sensor, an infrared sensor, etc. The front obstacle and the size of the obstacle are detected by visual, ultrasonic, infrared, etc. When there is an obstacle in front of the automatic mower 1, the movable control module controls the movable guard 4 and the cutting mechanism 3 to move automatically to avoid the obstacle, and adjusts the movement distance of the movable guard 4 and the cutting mechanism 3 according to the size of the obstacle. When adjusting the movement distance of the movable guard 4 and the cutting mechanism 3, the movable guard 4 can be controlled to move the same distance as the cutting mechanism 3 synchronously, or the movable guard 4 can be controlled to move a different distance from the cutting mechanism 3 asynchronously. When there is no obstacle in front of the automatic mower 1, the movable control module controls the movable guard 4 and the cutting mechanism 3 to return to the original state. When there is an obstacle in front of the automatic mower 1, but the obstacle is too large, the movable control module controls the movable guard 4 and the cutting mechanism 3 not to move, and controls the automatic mower 1 to stop or turn to avoid colliding with the obstacle according to the actual situation.

[0144] In the above embodiments, the cutting mechanism 3 can be arranged near the center axis in the advancing direction of the automatic mower 1, or arranged on one side of the center axis to achieve cutting to the edge. The movable guard 41 and / or the mechanism guard 42 in the corresponding embodiments are also arranged on one side of the center axis in the advancing direction of the automatic mower 1 to prevent the fingers or arms of children from extending into the cutting mechanism 3 and causing injury while achieving cutting to the edge. As shown in Figure 30 For example, in the embodiment where the movable guard 41 and the cutting mechanism 3 are arranged on one side of the center axis, the lower end 417 of the movable guard wall can move relative to the ground. As shown in Figure 31 When the user lifts the automatic mower 1, his hands are on both sides of the automatic mower 1, and the fingers exert an upward pushing force on the movable guard 41, causing the movable guard wall 414 to move upward. The user's hands cannot lift the automatic mower 1 by exerting force on the movable guard 41, but only by exerting force on the outer side guard wall 14 of the housing 10. At this time, although the hands cannot directly hold the movable guard wall 417, when holding the outer side guard wall 14, the fingers can still extend below the movable guard 41, so the movable guard 41 also includes a lower movable guard wall 4149 arranged below the cutting element 32 to prevent the user's fingers from extending below the movable guard 41 near the cutting element 32.

[0145] Because the movable guard wall 417 is arranged between the outer side guard wall 14 and the cutting mechanism 3, the outer side guard wall 14 is farther from the cutting element 32 than the movable guard wall 417. When the user's fingers extend from the outer side guard wall 14 into the cutting mechanism 3, the fingers can touch below the movable guard 41 by a distance less than the length of the fingers, so the width of the lower movable guard wall 4149 in the direction of finger extension is less than the length of the fingers. However, as the distance between the outer side guard wall 14 and the movable guard wall 417 increases, the width of the lower movable guard wall 4149 in the direction of finger extension, i.e., in the horizontal direction perpendicular to the advancing direction of the automatic mower 1, can be arranged to be shorter, or even unnecessary, thereby greatly improving the passability of the automatic mower 1 while ensuring the safety of the user lifting the automatic mower 1.

[0146] As shown in Figure 30 and 31 The movable guard wall includes a vertical guard wall extending in the vertical direction and a horizontal guard wall below the vertical guard wall and extending in the horizontal direction. At least one side of the horizontal guard wall protrudes from the corresponding side of the vertical guard wall, so that when the movable guard wall is subjected to the buoyancy of the grass, it has a larger force receiving surface and can be subjected to a larger lifting force of the grass, thereby enhancing the passability. As shown in Figure 30As shown, the inner side of the horizontal protective wall can protrude from the inner side of the vertical protective wall, the outer side of the horizontal protective wall can protrude from the outer side of the vertical protective wall, or the inner and outer sides of the horizontal protective wall can protrude from the inner and outer sides of the vertical protective wall. Specifically, the width of the horizontal protective wall in the inner-outer direction is 5-50 mm.

[0147] The shell 10 further comprises an outer protective wall 14 outside the movable protective member 41, and the lower end of the outer protective wall 14 is spaced apart from the ground by a distance less than 75 mm to prevent the arms of an adult from reaching into the inside of the cutting mechanism 3. In an embodiment, the lower end of the outer protective wall 14 is spaced apart from the ground by a distance of 35-55 mm, which prevents the arms of an adult from reaching into the cutting mechanism 3 while limiting the angle of inclination of the arms of a child when reaching into the shell 10 from below the outer protective wall 14, thereby reducing the risk of the arms of a child touching the cutting mechanism 3 when reaching upwardly.

[0148] The automatic working system further comprises a guide line, and the automatic mower 1 further comprises a guide line detection module (not shown) comprising at least one guide line detection sensor for detecting the positional relationship between the automatic mower and the guide line. The positional relationship between the automatic mower and the guide line includes that the automatic mower is located on one side of the guide line or the distance between the automatic mower and the guide line. In the embodiment, the guide line comprises a boundary line for defining the working area of the automatic mower. In other embodiments, the guide line can also be a guide line arranged in the working area and leading from the location of the docking station for guiding the automatic mower to move towards the docking station. Of course, the guide line can also be a physical boundary formed by a fence or a physical boundary formed between a lawn and a non-lawn. Correspondingly, the guide line detection sensor can be a camera, a capacitive sensor, etc. In other embodiments, there can be no guide line, and the working area of the automatic mower can be controlled directly by a capacitive sensor or a GPS positioning method.

[0149] A threshold value is preset, and when the electric energy in the energy module is lower than the threshold value, the control module 50 controls the automatic mower 1 to move along the boundary line towards the docking station to return the automatic mower 1 to the charging station to supplement the electric energy of the energy module. During the process of controlling the automatic mower 1 to move along the boundary line towards the docking station, the control module 50 controls the automatic mower 1 to change the distance between the automatic mower 1 and the boundary line, and then controls the automatic mower 1 to move in a direction parallel to the boundary line by at least a first preset distance, and repeats the above steps to realize the control of the control module 50 to return the automatic mower 1 to the charging station. In other embodiments, the automatic mower 1 can also return to the charging station by other methods. In other embodiments, the automatic mower 1 can also return to the charging station to supplement the electric energy by a preset time or other parameters when the specified time or other parameters are reached.

[0150] Any combination of the technical features in the above-described embodiments can be made, and for the sake of brevity, not all possible combinations are described, however, as long as the combination of the technical features does not exist in contradiction, it shall be considered within the scope of the present disclosure.

[0151] The above-described embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it shall not be understood as a limitation on the patent scope of the present application. It shall be pointed out that, for ordinary skilled persons in the art, several modifications and improvements can be made without departing from the concept of the present application, and these shall be within the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.

Claims

1. An automatic lawn mower comprising: A housing, provided with a bottom shell; A moving module, disposed below the housing, for driving the automatic lawn mower to move; a cutting mechanism, disposed on the housing to perform a cutting task at a predetermined cutting height, the cutting mechanism comprising a cutting element for cutting; The control module is used to autonomously control the movement module to drive the automatic lawn mower to move, and autonomously control the cutting mechanism to perform the cutting task; its characteristics are: The automatic lawn mower also includes a movable protective part with a movable protective wall for safety protection. In the horizontal direction, the movable protective wall is arranged on the outside of the cutting mechanism. When the movable protective part is in a free state without being subjected to external force, the lower end of the movable protective wall is at an initial distance from the ground. When the cutting mechanism is at any cutting height, the initial distance remains unchanged and is always less than M, where 38mm≤M≤40mm; under the action of external force, the movable protective part can move upward as a whole compared to the bottom shell, so that the ground distance of all points on the lower surface of the movable protective wall is increased.

2. The automatic lawn mower according to claim 1, wherein: During the process of adjusting the height of the cutting mechanism, the cutting mechanism may move relative to the movable protective wall.

3. The automatic lawn mower according to claim 1, wherein: When an external force is applied, the lower end of the movable protective wall moves upwards by no less than 15 mm.

4. The automatic lawn mower according to claim 3, wherein: Under the action of external force, the lower end of the movable protective wall can move in the vertical direction by a distance ranging from 15 to 80 mm, or from 20 to 40 mm.

5. The automatic lawn mower according to any one of claims 1 to 3, characterized in that: When the cutting mechanism is at any cutting height, the movable protective member can move upward compared to the bottom shell under the action of external force, so that the distance of the movable protective wall from the ground is increased; when the external force is eliminated, the movable protective member can move downward compared to the bottom shell, so that the distance of the lower end of the movable protective wall from the ground returns to the initial distance.

6. The automatic lawn mower according to any one of claims 1 to 3, characterized in that: The movable protective wall further includes a vertical protective wall extending in the up-down direction and a horizontal protective wall located below the vertical protective wall and extending in the horizontal direction, wherein the outermost side of the horizontal protective wall protrudes from the outermost side of the vertical protective wall.

7. The automatic lawn mower according to any one of claims 1 to 3, characterized in that: The automatic lawn mower further includes a guard upward guiding mechanism for connecting the housing and the movable guard.

8. The automatic lawn mower according to claim 7, wherein: The upward guiding mechanism includes at least one of a four-link mechanism, a two-link mechanism, a single link mechanism or a sliding groove.

9. The automatic lawn mower according to any one of claims 1 to 3, characterized in that: The initial distance ranges from 15 to 35 mm.

10. The automatic lawn mower according to any one of claims 1 to 3, characterized in that: The initial distance is less than or equal to M / 2.

11. The automatic lawn mower according to any one of claims 1 to 3, characterized in that: The movable protective wall includes at least one of a front movable protective wall located in front of the cutting mechanism, side movable protective walls located on both sides of the cutting mechanism, and a rear movable protective wall located behind the cutting mechanism.

12. The automatic lawn mower according to claim 11, wherein: The movable protective wall includes at least a front movable protective wall arranged in front of the cutting mechanism and side movable protective walls arranged on both sides of the cutting mechanism. The front movable protective wall and the rear movable protective wall are connected to each other so that the front movable protective wall and the two side movable protective walls can move synchronously in the up and down directions under the action of external force.

13. The automatic lawn mower according to any one of claims 1 to 3, characterized in that: In the horizontal direction, the minimum distance X between the outermost edge of the movable protective wall and the cutting element is in the range of X≥58 mm, or 63 mm≤X≤75 mm.

14. The automatic lawn mower according to any one of claims 1 to 3, characterized in that: The movable protective member is arranged on the outside of the shell, and / or is arranged between the cutting mechanism and the shell, and / or is connected to a part of the shell.

15. The automatic lawn mower according to any one of claims 1 to 3, characterized in that: The automatic lawn mower also includes a mechanism guard provided with a mechanism guard wall. In the horizontal direction, the mechanism guard wall is arranged between the movable guard wall and the cutting mechanism. The mechanism guard and the cutting mechanism are relatively fixed in the upper and lower directions, and the lower end of the mechanism guard is always lower than the lowest point of the cutting element.

16. The automatic lawn mower according to any one of claims 1 to 3, characterized in that: At at least one cutting height, the movable guard can move relative to the cutting mechanism in the up and down directions under the action of external force. The automatic lawn mower also includes a limiting mechanism for limiting the degree of relative movement between the cutting mechanism and the movable guard in the up and down directions. When the movable guard is restricted by the limiting mechanism, the lower end of the movable guard wall is always lower than the lowest point of the cutting element.

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