Lawnmower rear discharge guide

Abstract

A lawn mower (100) includes a first blade (BL1) having a first tip and a second blade (BL2) having a second tip, wherein the first blade (BL1) and the second blade (BL2) are arranged side by side and a direction of rotation of the first blade (BL1) differs from a direction of rotation of the second blade (BL2), wherein in a lateral direction of the lawn mower (100), a guide plate (PL1) is arranged between a center of rotation of the first blade (BL1) and a center of rotation of the second blade (BL2), and the guide plate (PL1) is arranged above the second blade (BL2), and the guide plate (PL1) extends toward a rear side of the lawn mower (100).

Description

BACKGROUND OF THE DISCLOSURETechnical Area

[0001] The disclosure relates to a lawn mower and in particular to a guide for a rear discharge of the lawn mower. State of the art

[0002] JP 2007-89 498 A describes a lawn mower with adjacent blades. The blades rotate in the same direction. Guide plates 35, 38 are arranged above the blades toward the rear of the mower.

[0003] A guide is needed to guide the grass cut by the lawnmower, whose blades are located next to each other and rotate in different directions.

[0004] US 6 038 840 A discloses a rear-discharge mower with a mower deck defining grass clipping flow paths for directing grass clippings rearward. The mower unit includes a power transmission mechanism for rotating a center blade and a second side blade in one direction and a first side blade in the other direction, a center deflector extending about a rotational axis of the center blade and defining a center flow path for supplying grass clippings to a grass clipping outlet, a first side deflector extending about a rotational axis of the first side blade, and a second side deflector extending about a rotational axis of the second side blade.

[0005] US 2013 / 0 212 995 A1 discloses a ride-on mower having two lateral mowing blades, a mowing deck, and two motors for rotating the mowing blades. The mowing blades are positioned side by side, and one of the two mowing blades is arranged diagonally in front of the other mowing blade. In plan view, the left mowing blade rotates clockwise and the right mowing blade rotates counterclockwise. A combined airflow is generated within the mowing deck, and the cut grass is expelled from the mowing deck along with the combined airflow.

[0006] JP 2015-084710 A discloses a mower. A pair of left and right blade bodies rotating in a substantially horizontal direction about a vertical axis are composed of a plurality of blade parts having the same length, and each blade part has an equal phase and corresponds to each other.

[0007] US 6,609,358 B1 discloses a mower with movable chamber flap elements that allow the mower to operate selectively in a discharge or mulching mode. The mower includes a control structure that actuates the flap elements. SUMMARY OF THE INVENTION

[0008] The present invention is provided by the appended claim 1. The dependent claims show advantageous embodiments of the invention. The following disclosure serves to facilitate understanding of the invention. According to one embodiment of the disclosure, a lawn mower includes a first blade having a first tip and a second blade having a second tip, wherein the first blade and the second blade are arranged side by side and a rotation direction of the first blade is different from a rotation direction of the second blade, wherein in a lateral direction of the lawn mower, a guide plate is arranged between a rotation center of the first blade and a rotation center of the second blade, the guide plate is arranged above the second blade, and the guide plate extends toward a rear of the lawn mower. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Embodiments will now be described by way of example only with reference to the accompanying drawings, which are intended to be illustrative and not restrictive, and in which like elements are numbered alike in several drawings. Fig. 1 is a schematic diagram showing a perspective view of a lawn mower according to an embodiment of the disclosure; Fig. 2 is a schematic diagram of a top view of the lawn mower of Fig. 1; Fig. 3 is a schematic diagram of a side view of the lawn mower of Fig. 1; Fig. 4 is a schematic diagram showing a bottom view of a grass cutting unit of the lawn mower and a rear discharge of cut grass from the lawn mower; Fig. 5 is a schematic diagram of a guide plate according to an embodiment of the disclosure; Fig. 6 is a schematic diagram showing a configuration of the guide plate with respect to adjacent knives rotating in different directions; Fig. Figure 7A is a schematic diagram showing a side view of the guide plate of Fig. 7A shows; Fig. Figure 7B is a schematic diagram showing how cut grass is caught on a guide plate; Fig. 8A shows a guide plate with a curved part according to another embodiment of the disclosure; Fig. 8B is a schematic diagram showing a side view of the bent part of Fig. 8A shows; Fig. 9 is a schematic diagram showing a second guide plate according to an embodiment of the disclosure; Fig. 10 is a schematic diagram of a third guide plate according to a comparative example; Fig. 11 is a schematic diagram showing a side view of an inclined plate according to an embodiment of the disclosure; DESCRIPTION OF THE EMBODIMENTS

[0010] Fig. 1 is a schematic diagram showing a perspective view of a lawn mower according to an embodiment of the disclosure. Fig. 2 is a schematic diagram of a top view of the lawn mower of Fig. 1. Fig. 3 is a schematic diagram showing a side view of the lawn mower of Fig. 1 shows. With reference to Fig. 1~ Fig. 3, a lawn mower 100 is provided. In the present embodiment, the lawn mower 100 includes a grass cutting unit 10, a control console 20, a battery 30, a plurality of motors 40A, 40B, 40C, and a plurality of motor drivers 50A, 50B, 50C. The lawn mower 100 also includes a standing platform 60 and a cushion 70. The plurality of motors 40A, 40B, 40C include a first motor 40A, a second motor 40B, and a third motor 40C. The plurality of motors 40A, 40B, 40C are arranged on the grass cutting unit 10. The second motor 40B is arranged between the first motor 40A and the third motor 40C.

[0011] The control console 20 may include controls that allow an operator to control the lawn mower 100, such as driving, steering, turning on the grass cutting unit 10, and the like. The plurality of motor drivers 50A, 50B, 50C respectively drive the plurality of motors 40A, 40B, 40C. The standing platform 60 is configured for the operator to stand upon, and the operator may lean on or against the cushion 70 for comfort. In another embodiment of the disclosure, the lawn mower 100 may include a seat on which the operator may sit to operate the lawn mower 100. In another embodiment of the disclosure, the lawn mower 100 may be a robot that operates without the operator on board the lawn mower 100. The type of lawn mower is not intended to limit the disclosure.

[0012] Fig. Figure 4 is a schematic diagram showing a bottom view of a grass cutting unit of the lawn mower and a rear discharge of cut grass from the lawn mower. As shown in Fig. As shown in Figure 4, a first blade BL1 is connected to a first shaft SFT1 of the first motor 40A. A second blade BL2 is connected to a second shaft SFT2 of the second motor 40B. A third blade BL3 is connected to a third shaft SFT3 of the third motor 40C. The first blade BL1 and the second blade BL2 are arranged side by side.

[0013] If you look at the grass cutting unit 10 from below, as in Fig. As shown in Figure 4, the first blade BL1 is rotated counterclockwise (CCW1) by the first motor 40A via the first shaft SFT1. The second blade BL2 is rotated clockwise (CW2) by the second motor 40B via the second shaft SFT2. The third blade BL3 is rotated clockwise (CW3) by the third motor 40C via the third shaft SFT3.

[0014] The counterclockwise CCW1 rotation direction of the first blade BL1 is different from the clockwise CW2 rotation direction of the second blade BL2. This means that the rotation direction of the first blade BL1 is different from the rotation direction of the second blade BL2. Furthermore, the counterclockwise CCW1 rotation direction of the first blade BL1 is different from the clockwise CW3 rotation direction of the third blade BL3. This means that the rotation direction of the first blade BL1 is different from the rotation direction of the third blade BL3.

[0015] In the present embodiment, the counterclockwise direction CCW1 is a direction substantially opposite to the clockwise direction CW2, and the counterclockwise direction CCW1 is a direction substantially opposite to the clockwise direction CW3. In the present embodiment, the clockwise direction CW2 is a direction substantially consistent with the clockwise direction CW3.

[0016] Referring to Fig. 4, it was discovered through the inventor's research that in a lawn mower 100 in which the first blade BL1 and the second blade BL2 are arranged side by side and a rotation direction CCW1 of the first blade BL1 differs from a rotation direction CW2 of the second blade BL2, the grass cut by the first blade BL1 may be combined with the grass cut by the second blade BL2 to form a clump. The clump of cut grass discharged toward the rear of the lawn mower 100 would appear as clumped grass clumped toward a certain side in a lateral direction of the lawn mower 100. The clumped grass was discharged toward the third blade BL3 in the lateral direction of the lawn mower 100. In the present embodiment, the lateral direction is a direction substantially perpendicular to a moving / traveling direction of the lawn mower 100.

[0017] With further reference to Fig. 4, the grass cut by the first blade BL1 is ejected in a first direction D1 toward a rear of the lawn mower 100. The grass cut by the second blade BL2 is ejected in a second direction D2 toward the rear of the lawn mower 100. The grass cut by the third blade BL3 is ejected in a third direction D3 toward the rear of the lawn mower 100. The first direction D1 is a direction substantially parallel to the second direction D2. The first direction D1 and the second direction D2 intersect with the third direction D3. The first direction D1 and the second direction D2 include a directional component in the lateral direction of the lawn mower 100 toward the third blade BL3.Since the cut grass CG ejected to the rear of the lawn mower 100 would clump in the lateral direction of the lawn mower 100 toward the side of the third blade BL3, the mowed lawn would appear uneven and / or disordered (see, for example, the example shown in . Fig. 4 shown cut grass CG).

[0018] Fig. 5 is a schematic diagram showing a guide plate according to an embodiment of the disclosure. Referring to Fig. 5, a guide plate PL1 is arranged between a rotation center of the first blade BL1 and a rotation center of the second blade BL2 in the lateral direction of the lawn mower 100. In the present embodiment, the guide plate PL1 has a rectangular shape, but the disclosure is not limited thereto. The guide plate PL1 may be attached directly or indirectly to a housing of the grass cutting unit 10. The guide plate PL1 may be fixed to the housing of the grass cutting unit 10, for example, by a fastener, an adhesive, welding, and / or the like. The guide plate PL1 has a plate shape, and the guide plate PL1 extends toward a rear side of the lawn mower 100. A material of the guide plate PL1 may be, for example, aluminum, plastic, metal, or the like.However, the disclosure is not limited thereto, and the material of the guide plate PL1 can be determined according to requirements. The guide plate PL1 can prevent the grass cut by the first blade BL1 from merging with the grass cut by the second blade BL2. In this way, the guide plate PL1 can contribute to ejecting the cut grass more evenly across the lateral direction of the lawn mower 100, so that accumulation or clumping of the cut grass can be prevented.

[0019] Referring to Fig. 5, the front end of the guide plate PL1 is positioned closer to the rotation center of the second blade BL2 than to the rotation center of the first blade BL1. That is, a distance between the front end of the guide plate PL1 and the rotation center of the second blade BL2 is smaller than a distance between the front end of the guide plate PL1 and the rotation center of the first blade BL1. This prevents the cut grass from accumulating on the back of the second blade BL2.

[0020] Fig. Figure 6 is a schematic diagram showing a configuration of the guide plate with respect to adjacent blades rotating in different directions. Referring to Fig. 6, a first line L1 is represented by an imaginary line passing through the pivot point of the first blade BL1 and the pivot point of the second blade BL2. A front end of the guide plate PL1 is located in front of the first line L1 in a front-to-rear direction of the lawn mower. The front-to-rear direction is a direction perpendicular to the lateral direction of the lawn mower 100. That is, the front-to-rear direction is a direction substantially parallel to the moving / traveling direction of the lawn mower 100. The cut grass can be better guided by installing the guide plate PL1 at a position in front of the position where the grass cut by the first blade BL1 and the grass cut by the second blade BL2 are joined.

[0021] With further reference to Fig. 6, the first blade BL1 is arranged at a position behind the second blade BL2 in the front-to-rear direction of the lawn mower 100. That is, the rotation center of the first blade BL1 is arranged at a position behind the rotation center of the second blade BL2 in the front-to-rear direction of the lawn mower 100. In other words, the rotation center of the second blade BL2 is arranged at a position forward of the rotation center of the first blade BL1 in the front-to-rear direction of the lawn mower 100. In this way, the second blade BL2 overlaps with the first blade BL1 and the third blade BL3 in the lateral direction of the lawn mower 100 to reduce the possibility of uncut grass.

[0022] Referring to Fig. 6, a second line L2 is represented by an imaginary line perpendicular to the first line L1. The second line L2 is located between a rotational circumference of the first blade BL1 and a rotational circumference of the second blade BL2. The rotational circumference of the first blade BL1 and the rotational circumference of the second blade BL2 are each represented by dotted circles. The rotational circumferences are virtual rotational circumferences for explanatory purposes. The second line L2 is generally tangent to the rotational circumference of the first blade BL1 and the rotational circumference of the second blade BL2.

[0023] It should be noted that a small gap (space) may be formed between the rotation circumference of the first knife BL1 and the rotation circumference of the second knife BL2 so that the first knife BL1 and the second knife BL2 do not collide with each other.

[0024] Referring to Fig. 6, a third line L3 is represented by an imaginary line, which is an extension of the guide plate PL1. More specifically, the third line L3 is an extension of the guide plate PL1 toward the rear of the lawn mower 100. The third line L3 and the second line L2 intersect at an acute angle α at a position rearward of the first line L1 in the front-rear direction of the lawn mower 100. In other words, the third line L3 intersects the second line L2 to form the acute angle α at a position rearward of the first line L1 in the front-rear direction. In this way, the cut grass can be prevented from accumulating in the rear direction of the first line L1, so that the cut grass can be ejected more evenly.

[0025] Fig. Figure 7A is a schematic diagram showing a side view of the guide plate of Fig. 7A shows. More specifically, the side view is a view of the guide plate seen in the lateral direction of the lawn mower 100. With reference to Fig. 7A, the second blade BL2 has tips located at one end thereof. The tips of the second blade BL2 are portions of the second blade BL2 that cut grass during rotation of the second blade BL2. A portion of the second blade BL2 that is away from the tips and toward a rotation center of the second blade BL2 does not cut grass as well as the tips of the second blade BL2. The tips of the second blade BL2 are inclined upward at an angle with respect to a body portion of the second blade BL2. The tips of the second blade BL2 create a negative pressure during rotation, and the grass is lifted due to the negative pressure. The second blade BL2 can cut grass more easily when the grass is lifted by the negative pressure created by the inclined tip of the second blade BL2. The first blade BL1 and the third blade BL3 may have similarly inclined tips.

[0026] Referring to Fig. 7A, the guide plate PL1 is arranged above the second blade BL2 in a vertical direction of the lawn mower 100. The vertical direction is a direction perpendicular to the lateral direction and perpendicular to the front-rear direction. Specifically, a distance between the housing H(H1) of the grass cutting unit 10 and the guide plate PL1 is smaller than a distance between the housing H1 and the second blade BL2. That is, the guide plate PL1 protrudes from the housing of the grass cutting unit 10, while the second shaft SFT2 protrudes more from the housing of the grass cutting unit 10 than the guide plate PL1.

[0027] Referring to Fig. 7A, the grass cutting unit 10 may include the housing H2 and the housing H3 in addition to the housing H1. The housing H2 extends from the housing H1, and the housing H3 extends from the housing H1. The grass to be cut may be pressed down by the housing H2 and the housing H3, but the grass pressed down by the housing H2 and the housing H3 may be lifted (to stand up) by the airflow generated by the rotating blades. The grass can be cut more easily by the rotating blades after being lifted by the airflow. The housing H2 and the housing H3 may or may not be included depending on the need.

[0028] Fig. Figure 7B is a schematic diagram showing how the cut grass is caught or caught on a guide plate. Fig. 7B shows the guide plate PL1 as seen from the bottom of the grass cutting unit 10. With reference to Fig. 7B, the cut grass CG can be caught at the front end of the guide plate PL1. The cut grass CG caught at the guide plate PL1 can accumulate and fall off, resulting in clumped grass on the mowed lawn.

[0029] Fig. 8A shows a guide plate with a curved or bent part according to an embodiment of the disclosure. Referring to Fig. 8A, in another embodiment of the disclosure, the guide plate PL1 may include a bent part PLO disposed at a front portion of the guide plate. In the present embodiment, the bent part PLO extends from the front end of the guide plate PL1. However, the disclosure is not limited thereto. The bent part PLO can prevent the cut grass CG from being caught on the front end of the guide plate PL1 and falling off as a clump of grass. Furthermore, the bent part PLO can increase the rigidity of the guide plate PL1. In another embodiment of the disclosure, a gap (space) may be formed between the bent part PLO and the front end of the guide plate PL1.

[0030] Referring to Fig. 8A, in the present embodiment, the curved part PLO is a circular part concentric with the rotation center of the second blade BL2. In this way, the curved part PLO can prevent the cut grass CG from being caught at the front end of the guide plate PL1 without disturbing an airflow generated by the rotation of the blade. In the present embodiment, the guide plate PL1 is arranged so as to be tangent to the circular part. In the present embodiment, the circular part PLO is formed by enclosing the entire circumference of the second shaft SFT2. However, the disclosure is not limited to this. In another embodiment, the curved part PLO may not surround the entire circumference of the second shaft SFT2. For example, the curved part PLO may surround a portion of the circumference of the second shaft SFT2.In addition, there may be a plurality of parts (curved parts and / or non-curved parts (substantially straight parts)) surrounding a portion or the entirety of the second shaft SFT2.

[0031] Fig. 8B is a schematic diagram showing a side view of the bent part of Fig. 8A. More specifically, the side view is a view of the guide plate in the lateral direction of the lawn mower 100. The housing H2 and the housing H3 are in Fig. 8B is not shown. The circular part PLO is located closer to a rotation center of the second blade BL2 compared to a cutting portion of the second blade used for cutting. That is, the circular part PLO is arranged closer to the second shaft SFT2 than the tip of the second blade BL2 used for cutting. In other words, the distance between the second shaft SFT2 and the circular part PLO is smaller than the distance between the second shaft SFT2 and the tip of the second blade BL2. In this way, the circular part PLO is provided at a position that does not hinder the cutting of grass (for example, by pushing down the grass to be cut).

[0032] As in Fig. As shown in Figure 8B, the round part PLO may be directly or indirectly attached to a housing of the grass cutting unit 10. The circular plate PLO may be attached to the housing of the grass cutting unit 10, for example, by a fastener, adhesive, welding, and / or the like. In another embodiment, the round plate PLO may be attached to the guide plate PL1. In another embodiment, the circular plate PLO may be integrally formed with the guide plate PL1.

[0033] Fig. 9 is a schematic diagram of a second guide plate according to an embodiment of the disclosure. In an embodiment of the disclosure, the grass cutting unit 10 may further include a second guide plate PL2 disposed on the housing H1 of the grass cutting unit 10. More specifically, the second guide plate PL2 is disposed in front of the first blade BL1 and the second blade BL2 in the front-rear direction of the lawn mower 100. The second guide plate PL2 is disposed around the rotational circumference of the first blade BL1 and the rotational circumference of the second blade BL2. The second guide plate BL2 includes a first arc portion ARC1 around the first blade BL1, a second arc portion ARC2 around the second blade BL2, and an orientation part OP oriented from the first arc portion ARC1 toward the rotational circumference of the second blade.

[0034] With reference to Fig. 9, the first arc part ARC1 has a curved shape, and the second arc part ARC2 has a curved shape. The alignment part OP is arranged between the first arc part ARC1 and the second arc part ARC2. The alignment part OP connects the first arc part ARC1 and the second arc part ARC2. The alignment part OP has a substantially straight shape. By providing the substantially straight alignment part OP, an air flow AF1 generated by the first blade BL1 can be divided into a plurality of directions. Furthermore, by including the substantially straight alignment part OP, an air flow AF2 generated by the second blade BL2 can be divided into a plurality of directions. By dividing the air flow AF1 and the air flow AF2 due to the action of the alignment part OP, the air flow AF1 can flow in the first direction D1 and the air flow AF2 in the second direction D2 (see Fig. 4). In addition, the alignment part OP can also prevent the cut grass from being ejected from the front of the lawn mower 100 by blocking the cut grass from being ejected from the front of the lawn mower 100.

[0035] Fig. 10 is a schematic diagram showing a third guide plate according to a comparative example. Referring to Fig. 10 there is a difference between the configuration of Fig. 9 and Fig. 10 in that the alignment part OP in the configuration of Fig. 10 is omitted from the third guide plate PL3. As in Fig. As shown in Figure 10, the first arc part ARC1 is directly connected to the second arc part ARC2 without a substantially straight section (without the alignment part OP). If the alignment part OP is omitted, the air flow AF1 cannot split into a plurality of directions and the air flow AF2 cannot split into a plurality of directions. Since the air flow AF1 and the air flow AF2 cannot split into a plurality of directions, the air flow AF1 is in the first direction D1 and the air flow AF2 is in the second direction D2 (see Fig. 4) compared to the configuration of Fig. 9 increased with the alignment part OP.

[0036] Fig. 11 is a schematic diagram showing a side view of an inclined plate according to an embodiment of the disclosure. Specifically, the side view is a view of the inclined plate as seen from the lateral direction of the lawn mower 100 (note that the guide plate PL1 and the curved part PLO are shown in Fig. 11 are omitted). With reference to Fig. 11, an inclined plate 35 is arranged on the housing H1 of the grass cutting unit 10. The inclined plate 35 can be attached directly or indirectly to the housing H1 of the grass cutting unit 10. The inclined plate 35 can be secured to the housing H1 of the grass cutting unit 10, for example, by a fastener, an adhesive, welding, and / or the like.

[0037] With reference to Fig.11, the inclined plate 35 is arranged at the rear of the first blade BL1 and the second blade BL2 in the front-to-rear direction of the lawn mower 100. A distance between an inclined surface of the inclined plate 35 and the housing H1 gradually changes in the front-to-rear direction of the lawn mower 100. A distance between the inclined surface of the inclined plate 35 and the housing H1 at the rear of the lawn mower 100 is greater than a distance between the inclined surface of the inclined plate 35 and the housing H1 at the front of the lawn mower 100. The inclined plate 35 assists in discharging the cut grass toward the rear bottom of the lawn mower 100. Discharging the cut grass rearward is called "rear discharge." In comparison, discharging the cut grass sideways (in the lateral direction) is called "side discharge."The inclined plate 35 is mainly used on lawn mowers 100 with rear discharge.

[0038] Although embodiments of the lawn mower and guide plates according to the disclosure have been described above by way of some examples, the disclosure is not limited thereto.

[0039] It will be apparent to those skilled in the art that various modifications and variations may be made to the disclosed embodiments without departing from the scope or spirit of the disclosure. In view of the foregoing, the disclosure is intended to cover modifications and variations provided they fall within the scope of the following claims and their equivalents.

Claims

[1] Lawn mower (100), comprising: a first knife (BL1) with a first tip; and a second knife (BL2) with a second tip, wherein the first knife (BL1) and the second knife (BL2) are arranged next to each other and a direction of rotation (CCW1) of the first knife (BL1) differs from a direction of rotation (CW2) of the second knife (BL2), wherein in a lateral direction of the lawn mower (100) which is substantially perpendicular to a front-rear direction of the lawn mower (100), a guide plate (PL1) is arranged between a rotation center of the first blade (BL1) and a rotation center of the second blade (BL2), and the guide plate (PL1) is arranged above the second blade (BL2), and the guide plate (PL1) extends in the front-rear direction of the lawn mower (100) to a rear side of the lawn mower (100), wherein the guide plate (PL1) prevents grass cut by the first blade (BL1) and grass cut by the second blade (BL2) from merging in order to eject cut grass more evenly across the lateral direction of the lawn mower (100), wherein, when a first line (L1) is represented by an imaginary line passing through the center of rotation of the first blade (BL1) and the center of rotation of the second blade (BL2), a front end of the guide plate (PL1) is located in front of the first line (L1) in the front-rear direction of the lawn mower (100), and wherein a second line (L2) is represented by an imaginary line perpendicular to the first line (L1), and the second line (L2) is located between a rotational circumference of the first blade (BL1) and a rotational circumference of the second blade (BL2), and a third line (L3) is represented by an imaginary line which is an extension of the guide plate (PL1), the third line (L3) and the second line (L2) cross each other at an acute angle (α) at ​​a position behind the first line (L1) in the front-rear direction of the lawn mower (100). [2] The lawn mower (100) according to claim 1, wherein the first blade (BL1) is arranged at a position rearward of the second blade (BL2) in the front-rear direction of the lawn mower (100), and the front end of the guide plate (PL1) is arranged closer to the rotation center of the second blade (BL2) relative to the rotation center of the first blade (BL1). [3] The lawn mower (100) according to claim 1, wherein the guide plate (PL1) has a bent part (PLO) at a front portion of the guide plate (PL1). [4] The lawn mower (100) according to claim 2, wherein the guide plate (PL1) has a bent part (PLO) at a front portion of the guide plate (PL1). [5] A lawn mower (100) according to claim 3, wherein the curved part (PLO) is a circular part concentric with the center of rotation of the second blade (BL2). [6] A lawn mower (100) according to claim 4, wherein the curved part (PLO) is a circular part concentric with the center of rotation of the second blade (BL2). [7] The lawn mower (100) according to claim 5, wherein the circular part (PLO) is located closer to a rotation center of the second blade (BL2) than a cutting portion of the second blade (BL2) used for cutting. [8] The lawn mower (100) according to claim 6, wherein the circular part (PLO) is located closer to a rotation center of the second blade (BL2) than a cutting portion of the second blade (BL2) used for cutting. [9] Lawn mower (100) according to claim 2, further comprising: a front guide arranged around the rotational circumference of the first blade (BL1) and the rotational circumference of the second blade (BL2), the front guide comprising: a first arc section (ARC1) around the first knife (BL1); a second arc section (ARC2) around the second knife (BL2); an alignment part (OP) which is aligned from the first arc part (ARC1) to the rotation circumference of the second knife (BL2). [10] Lawn mower (100) according to claim 4, further comprising: a front guide arranged around the rotational circumference of the first blade (BL1) and the rotational circumference of the second blade (BL2), the front guide comprising: a first arc section (ARC1) around the first knife (BL1); a second arc section (ARC2) around the second knife (BL2); an alignment part (OP) which is aligned from the first arc part (ARC1) to the rotation circumference of the second knife (BL2). [11] Lawn mower (100) according to claim 6, further comprising: a front guide arranged around the rotational circumference of the first blade (BL1) and the rotational circumference of the second blade (BL2), the front guide comprising: a first arc section (ARC1) around the first knife (BL1); a second arc section (ARC2) around the second knife (BL2); an alignment part (OP) which is aligned from the first arc part (ARC1) to the rotation circumference of the second knife (BL2). [12] Lawn mower (100) according to claim 8, further comprising: a front guide arranged around the rotational circumference of the first blade (BL1) and the rotational circumference of the second blade (BL2), the front guide comprising: a first arc section (ARC1) around the first knife (BL1); a second arc section (ARC2) around the second knife (BL2); an alignment part (OP) which is aligned from the first arc part (ARC1) to the rotation circumference of the second knife (BL2).

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