Lawn mower and method of mowing with it

Abstract

To enable prevention of grass mowed by a mowing blade from being entangled with a mowing shaft.SOLUTION: A mower includes: a body part; a drive part which is provided in the body part; a mowing blade shaft which penetrates a lower surface of the body part, extends downward from the lower surface, and rotates by a drive force of the drive part; a mowing blade disc which is connected to a lower end portion of the mowing blade shaft, and rotates around the mowing blade shaft, and to which a mowing blade for mowing grass is supported; and a shaft protection cover which covers an outer periphery of a lower side portion of the mowing blade shaft extending out and exposed from the lower surface of the body part.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present disclosure relates to a lawn mower for mowing grass and a grass mowing method thereof.

Background Art

[0002] A lawn mower including a main body portion, a drive portion provided in the main body portion, a cutting blade shaft that rotates by the driving force of the drive portion, and a cutting blade disk that is connected to the lower end portion of the cutting blade shaft and rotates about the cutting blade shaft and supports a cutting blade for mowing grass is known (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when the cutting blade shaft rotates and grass is cut by the cutting blade, there is a risk that the cut grass will get caught on the cutting blade shaft.

[0005] The present disclosure has been made to solve such problems, and a main object thereof is to provide a lawn mower and a grass mowing method thereof that can prevent the grass cut by the cutting blade from getting caught on the cutting blade shaft.

Means for Solving the Problems

[0006] One aspect of the present disclosure for achieving the above object is a main body portion, a drive portion provided in the main body portion, a cutting blade shaft that penetrates the lower surface of the main body portion and extends downward from the lower surface and rotates by the driving force of the drive portion, a cutting blade disk that is connected to the lower end portion of the cutting blade shaft and rotates about the cutting blade shaft and supports a cutting blade for mowing grass, A shaft protection cover covers the outer circumference of the lower portion of the cutting blade shaft that is exposed from the lower surface of the main body, Equipped with, It's a lawnmower. On this flight, A cylindrical housing fixed to the base plate on the lower surface of the main body, A bearing provided on the inner circumference of the housing supports the cutting blade shaft, A ring-shaped oil seal is provided on the inner circumference of the housing and below the bearing, Below the oil seal, a shaft flange is provided integrally with the outer circumference of the cutting blade shaft and connected to the cutting blade disc, Furthermore, The shaft protection cover may be fixed to the base plate by sandwiching the periphery of the through hole in the base plate and the periphery of the through hole in the shaft protection cover between a nut from above and the lower end of the housing from below. On this flight, The main body may be an autonomous, mobile device. One aspect of this disclosure for achieving the above objectives is: A grass cutting method for a grass cutter comprising: a main body; a drive unit provided on the main body; a cutting blade shaft that penetrates the lower surface of the main body and extends downward from the lower surface, and rotates by the driving force of the drive unit; and a cutting blade disc connected to the lower end of the cutting blade shaft, which rotates around the cutting blade shaft and supports a cutting blade for cutting grass, wherein This is a grass cutting method in which the outer circumference of the lower part of the cutting blade shaft that is exposed from the lower surface of the main body is covered with a shaft protection cover, and the grass is cut by rotating the cutting blade shaft and the cutting blade disc. [Effects of the Invention]

[0007] According to this disclosure, it is possible to provide a grass trimmer and a grass trimming method that can prevent grass cut by the cutting blade from becoming entangled in the grass trimming shaft. [Brief explanation of the drawing]

[0008] [Figure 1] This is a perspective view showing the external appearance of the lawnmower according to this embodiment. [Figure 2] This is a perspective view showing the lower exterior of the lawnmower according to this embodiment. [Figure 3] This is a top view showing the external appearance of the top surface of the lawnmower according to this embodiment. [Figure 4] This is a block diagram showing the schematic system configuration of the lawnmower according to this embodiment. [Figure 5] Figure 3 shows a cross-sectional view of the grass cutting device when it is cut vertically along line AA, illustrating the general configuration of the grass cutting device. [Modes for carrying out the invention]

[0009] This embodiment will be described below with reference to the drawings. Figure 1 is a perspective view showing the external appearance of the lawnmower according to this embodiment. Figure 2 is a perspective view showing the lower external appearance of the lawnmower according to this embodiment. Figure 3 is a top view showing the upper external appearance of the lawnmower according to this embodiment. Figure 4 is a block diagram showing the schematic system configuration of the lawnmower according to this embodiment.

[0010] The grass trimmer 1 according to this embodiment is designed to cut grass growing in a predetermined area, such as a garden, while traveling within that area. The grass trimmer 1 according to this embodiment comprises a mobile device 2, a grass cutting device 3 mounted on the mobile device 2 for performing grass cutting work, and a control device 4 for controlling the mobile device 2 and the grass cutting device 3.

[0011] Mobile device 2 is a specific example of the main body. Mobile device 2 is configured to be able to move autonomously based on, for example, GPS signals transmitted from GPS (Global Positioning System) satellites and sensor information from various sensors 5 installed on mobile device 2, such as cameras, ultrasonic sensors, radar sensors, and rotation sensors.

[0012] The control device 4 controls the driving of the Caterpillar (registered trademark) 7 based on the above GPS signals and sensor information of various sensors 5, thereby performing forward and backward running and left and right turning running of the mobile device 2. Note that the mobile device 2 may perform forward and backward running, left and right turning running, etc. by, for example, rotationally driving wheels.

[0013] The drive unit 6 of the grass cutting device 3 performs rotational driving of the cutting blade shaft 31 as described below in response to a control signal from the control device 4.

[0014] Note that the control device 4 has a hardware configuration of a normal computer including, for example, a processor such as a CPU (Central Processing Unit) or GPU (Graphics Processing Unit), an internal memory such as a RAM (Random Access Memory) or ROM (Read Only Memory), a storage device such as an HDD (Hard Disk Drive) or SDD (Solid State Drive), an input / output I / F for connecting peripheral devices such as a display, and a communication I / F for communicating with devices outside the device.

[0015] FIG. 5 is a cross-sectional view when the grass cutting device is cut in the vertical direction along the line A-A shown in FIG. 3, and is a cross-sectional view showing a schematic configuration of the grass cutting device. As shown in FIG. 5, the grass cutting device 3 includes a cutting blade shaft 31, a cutting blade disk 32 connected to the cutting blade shaft 31, and a shaft protection cover 33 covering the outer peripheral portion of the cutting blade shaft 31.

[0016] A plate-shaped base plate 22 is connected to the lower surface 21 of the mobile device 2 by bolts 23 or the like. The lower end of the cutting blade shaft 31 penetrates the lower surface 21 and the base plate 22, extends outward from the lower surface 21 and the base plate 22, and extends downward. A shaft flange 34 is provided integrally with the cutting blade shaft 31 on the outer periphery of the cutting blade shaft 31. The cutting blade shaft 31 and the shaft flange constitute a rotating shaft integrally.

[0017] A cylindrical housing 35 extending upward is erected on the base plate 22. Bearings 36 are provided below and on the inner circumference of the housing 35. The bearings 36 rotatably support the cutting blade shaft 31 within the housing 35.

[0018] Furthermore, a ring-shaped oil seal 37 is provided on the inner circumference of the housing 35 and below the bearing 36. The oil seal 37 prevents oil from the bearing 36 from leaking to the outside and prevents foreign matter from adhering to the bearing 36 from the outside.

[0019] The cutting blade shaft 31 is connected to the drive shaft of the drive unit 6, such as a motor, via a reduction gear or the like. As a result, the cutting blade shaft 31 and the shaft flange 34 rotate due to the driving force of the drive unit 6.

[0020] The cutting blade disc 32 is a disc-shaped component. The cutting blade disc 32 is positioned parallel to the base plate 22 at a predetermined distance from the base plate 22. The cutting blade disc 32 is connected to the lower ends of the cutting blade shaft 31 and shaft flange 34 via bolts 38, 39, etc. Therefore, when the cutting blade shaft 31 and shaft flange 34 rotate, the cutting blade disc 32 also rotates around the cutting blade shaft 31.

[0021] Multiple cutting blades 40 are rotatably supported on the cutting disc 32. For example, as shown in Figure 2, three pairs of upper and lower cutting blades 40 for cutting grass are supported at equal intervals along the outer periphery of the upper and lower surfaces of the cutting disc 32.

[0022] As shown in Figure 5, the cutting blade support shaft 41 passes through the cutting blade disc 32 and the pair of upper and lower cutting blades 40 from below, and a nut 42 is screwed onto the tip of the cutting blade support shaft 41 from above. As a result, the pair of upper and lower cutting blades 40 are rotatably supported with respect to the cutting blade support shaft 41 fixed to the cutting blade disc 32. When the cutting blade disc 32 rotates around the cutting blade shaft 31, the centrifugal force causes the cutting blades 40 to rotate simultaneously around the cutting blade support shaft 41.

[0023] The number, position, support method, and shape of the cutting blades 40 provided on the cutting disc 32 may be appropriately changed depending on the type and density of grass to be cut.

[0024] As the cutting blade shaft 31 rotates due to the driving force of the drive unit 6, the cutting blade disc 32 rotates, and at the same time, the cutting blade 40 of the cutting blade disc 32 also rotates, and when the cutting blade 40 hits the grass, the grass can be cut.

[0025] Incidentally, in the past, when the cutting blade shaft rotated and cut dense grass with the cutting blade, there was a risk that the cut grass would get entangled in the cutting blade shaft. For example, grass longer than the circumference of the cutting blade shaft would get entangled in the cutting blade shaft, causing problems such as excessive load on the drive unit 6.

[0026] In contrast, in this embodiment, the shaft protection cover 33 covers the outer circumference of the cutting blade shaft 31 and shaft flange 34 that are exposed from the base plate 22. This prevents grass cut by the cutting blade 40 from becoming entangled in the cutting blade shaft 31 and shaft flange 34.

[0027] As shown in Figure 5, the shaft protection cover 33 is, for example, a substantially cylindrical member with a through hole 331 formed on its upper end surface and an open lower end. Note that the shape of the shaft protection cover 33 shown in Figure 5 is just one example, and it may be any shape as long as it can cover the outer circumference of the cutting blade shaft 31 and shaft flange 34 that are exposed from the lower surface 21 and the base plate 22.

[0028] A male thread is formed on the lower outer circumference of the housing 35, and as described later, a nut 44 is screwed onto this male thread from above via a spacer 43 to fix the shaft protection cover 33 to the base plate 22.

[0029] In other words, the lower end 351 of the housing 35 passes through the through hole 221 of the base plate 22 and the through hole 331 of the shaft protection cover 33. The shaft protection cover 33 is fixed to the base plate 22 by sandwiching the periphery of the through hole 221 of the base plate 22 and the periphery of the through hole 331 of the shaft protection cover 33 between the nut 44 from above and the lower end 351 of the housing 35 from below.

[0030] As described above, according to the grass cutting method of the grass cutter of this embodiment, when the cutting blade shaft 31 rotates due to the driving force of the drive unit 6 and the cutting blade disc 32 rotates, the cutting blade 40 of the cutting blade disc 32 also rotates at the same time. When this rotating cutting blade 40 comes into contact with the grass, the grass can be cut.

[0031] At this time, the cutting blade shaft 31 and shaft flange 34, which are exposed after emerging from the housing 35, are covered on their outer circumference by the shaft protection cover 33. As a result, even if grass cut by the cutting blade 40 is scattered towards the cutting blade shaft 31 and shaft flange 34, the shaft protection cover 33 reliably prevents the scattered grass from becoming entangled in the cutting blade shaft 31 and shaft flange 34.

[0032] Furthermore, the labyrinth structure formed between the shaft protection cover 33, the cutting blade shaft 31, the shaft flange 34, and the housing 35 and the oil seal 37 prevents foreign matter such as grass and soil scattered during grass cutting from coming into contact with the oil seal 37. This also leads to an improvement in the replacement life and reliability of the oil seal 37.

[0033] While several embodiments of this disclosure have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims and their equivalents. [Explanation of Symbols]

[0034] 1. Grass trimmer, 2. Mobile device, 3. Grass cutting device, 4. Control device, 5. Sensor, 6. Drive unit, 7. Caterpillar, 21. Underside, 22. Base plate, 23. Bolt, 31. Cutting blade shaft, 32. Cutting blade disc, 33. Shaft protection cover, 34. Shaft flange, 35. Housing, 36. Bearing, 37. Oil seal, 38. Bolt, 40. Cutting blade, 41. Cutting blade support shaft, 42. Nut, 43. Spacer, 44. Nut, 221. Through hole, 331. Through hole, 351. Lower end

Claims

1. The main body and The drive unit provided in the main body, The cutting blade shaft penetrates the lower surface of the main body and extends downward from the lower surface, and rotates by the driving force of the drive unit, A cutting blade disc is connected to the lower end of the cutting blade shaft and rotates around the cutting blade shaft, and a cutting blade for cutting grass is supported on the cutting blade disc, A shaft protection cover covers the outer circumference of the lower portion of the cutting blade shaft that is exposed from the lower surface of the main body, A cylindrical housing fixed to the base plate on the lower surface of the main body, A bearing provided on the inner circumference of the housing supports the cutting blade shaft, A ring-shaped oil seal is provided on the inner circumference of the housing and below the bearing, Below the oil seal, a shaft flange is provided integrally with the outer circumference of the cutting blade shaft and connected to the cutting blade disc, Equipped with, The shaft protection cover is fixed to the base plate by sandwiching the periphery of the through hole in the base plate and the periphery of the through hole in the shaft protection cover between a nut from above and the lower end of the housing from below. Lawn mower.

2. A grass trimmer according to claim 1, The main body is an autonomous, mobile device. Lawn mower.

3. A grass cutting method for a grass cutter, comprising: a main body; a drive unit provided on the main body; a cutting blade shaft that penetrates the lower surface of the main body and extends downward from the lower surface and rotates by the driving force of the drive unit; a cutting blade disc connected to the lower end of the cutting blade shaft and rotating around the cutting blade shaft, on which a cutting blade for cutting grass is supported; a cylindrical housing fixed to a base plate on the lower surface of the main body; a bearing provided on the inner circumference of the housing to pivotally support the cutting blade shaft; a ring-shaped oil seal provided on the inner circumference of the housing and below the bearing; and a shaft flange provided integrally with the cutting blade shaft on the outer circumference of the cutting blade shaft below the oil seal and connected to the cutting blade disc, wherein the shaft protection cover is fixed to the base plate by clamping the periphery of the through hole in the base plate and the periphery of the through hole in the shaft protection cover from above with a nut and from below with the lower end of the housing, A grass cutting method comprising rotating the cutting blade shaft and the cutting blade disc while covering the outer circumference of the lower portion of the cutting blade shaft that is exposed from the lower surface of the main body with the shaft protection cover, thereby cutting grass with the cutting blade.

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