CN114616974A - Mower and mowing blade - Google Patents

Abstract

The present invention provides a mowing blade rotatable about a first axis, comprising: a cutting part including a blade to perform cutting; extension, extension relative cutting part is close to first axis, and extension includes the main part, and the main part constitutes extension main part, and extension is set up to: there are at least three planes passing through the first axis, the cross-section of the body in the planes being substantially the same. The mower has long endurance time and high mowing performance, and the ineffective load generated by the mowing blade is reduced.

Description

Mower and mowing blade

Technical Field

The present invention relates to an electric tool, and more particularly to a lawnmower and a mowing blade.

Background

The lawn mower cuts vegetation through the mowing blade, the blade dead load is an important factor influencing the endurance time and the mowing performance of the lawn mower, however, the design requirement of the strength of the blade is difficult to reduce the blade dead load, and therefore the optimization of the whole performance of the lawn mower is not utilized.

Disclosure of Invention

To solve the problems of the prior art, an object of the present invention is to provide a lawnmower and a grass cutting blade, which have a long endurance time and high grass cutting performance, and which can reduce the dead load generated by the grass cutting blade.

To achieve the above primary object, the present invention provides a grass cutting blade rotatable about a first axis, comprising: a cutting part including a blade to perform cutting; extension, extension relative cutting part is close to first axis, and extension includes the main part, and the main part constitutes extension main part, and extension is set up to: there are at least three planes passing through the first axis, the cross-section of the body in the planes being substantially the same.

Optionally, the body comprises first and second sections disposed on either side of a centre line thereof, at least part of the first section being equidistant from the first axis at points on an inner edge of a cross-section perpendicular to the first axis and/or at least part of the second section being equidistant from the first axis at points on an edge of a cross-section perpendicular to the first axis.

Optionally, the main body includes a first section and a second section disposed on both sides of the center line, and a cutting surface formed by a section perpendicular to the first axis when the mowing blade rotates around the first axis is a revolution surface with the first axis as a rotation axis.

Optionally, the body comprises an upper surface and a lower surface, the upper surface being part of a side of a first cone with the first axis as the axis, and the lower surface being part of a side of a second cone with the first axis as the axis.

Optionally, the upper and lower surfaces are equally spaced in any radial direction along the first axis.

Optionally, when the mowing blade is driven to rotate, the main body has an equivalent load area on any cross section in the radial direction of the first axis, the main body is provided with at least one cross section in the radial direction of the first axis, and the ratio of the area of the cross section to the area of the equivalent load area of the cross section is set to be greater than or equal to 75%.

Optionally, the first or second section is arranged to have at least one cross-section radial to the first axis which coincides with the equivalent load area.

Optionally, the main body includes a light-load section, a ratio of an area of any one of the sections of the light-load section in a radial direction of the first axis to an area of an equivalent load region of the section is set to be greater than or equal to 75%, and a ratio of a length of the main body in a direction of a center line thereof to a length of the light-load section in a direction of a center line of the extension portion is greater than or equal to 1 and less than or equal to 3.

Optionally, the main body includes a light-load section, and any one section of the light-load section in the radial direction of the first axis coincides with an equivalent load area corresponding to the section.

Optionally, a lawn mower is provided, including a mowing blade, further including: the base is connected with the mowing blade; the motor is used for driving the mowing blade to rotate around the first axis; a power supply for supplying power to the motor; the driving wheel drives the base to walk.

Has the advantages that: according to the invention, by arranging the structure of the mowing blade, the form of the mowing blade is adjusted according to the theoretical equivalent load area of the cross section of the mowing blade when the mowing blade rotates, so that the invalid load of the blade is reduced, the mowing performance of a mower using the mowing blade is improved, and the endurance time of the mower is prolonged.

Drawings

FIG. 1 is a schematic structural diagram of a lawn mower provided in accordance with an embodiment of the present invention;

FIG. 2 is a schematic perspective view of a grass cutting blade according to an embodiment of the present invention;

FIG. 3 is a schematic plan view of the grass cutting blade of FIG. 2 of the present invention;

FIG. 4 is a schematic plan view of another angle of the grass cutting blade of FIG. 2 of the present invention;

FIG. 5 is a cross-sectional view of an extension of the mowing blade of FIG. 2 of the present invention;

figure 6 is a schematic view, in cross-section and rotated, of the section of the extension of figure 5 according to the invention;

figure 7 is a schematic view of a section of the extension of figure 5 of the invention and of its equivalent load area;

FIGS. 8a and 8b are schematic views of a plane through a first axis provided by an embodiment of the present invention;

figure 8c is a schematic cross-section of the extension of the invention in the plane of figure 8 a;

figures 9a, 9b are schematic views of the perpendicular distance of a point on the edge of the section of the extension of figure 5 from the first axis according to the invention;

FIG. 10 is a schematic view of a first cone and a second cone of the mowing blade of FIG. 2 of the present invention;

FIG. 11 is a schematic view of a prior art second grass cutting blade;

FIG. 12 is a cross-sectional, rotated schematic view of a second extension of the second grass cutting blade of FIG. 11 in accordance with the present invention;

FIG. 13 is a comparison of the equivalent load areas of the first and second mowing blades;

FIG. 14 is a schematic view of an equivalent load ring as the cross-section of the grass cutting blade of FIG. 5 rotates;

FIG. 15 is a schematic view of an equivalent load ring as a section of a second mowing blade rotates;

FIG. 16 is a schematic view of a light-load portion of a grass cutting blade according to an embodiment of the present invention;

FIG. 17 is a schematic view of a grass cutting blade according to an embodiment of the present invention;

fig. 18 is a cross-sectional schematic view of the grass cutting blade of fig. 17.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

The technical scheme of the invention is further explained by the specific implementation mode in combination with the attached drawings.

Referring to fig. 1 and 2, the present invention provides a grass cutting blade 100 and a grass mower 200 using the grass cutting blade 100, wherein the grass mower 200 performs grass cutting work by the grass cutting blade 100. The mower 200 comprises a base 210, a motor, a power supply and a driving wheel 220, wherein the mowing blade 100 is connected to the base 210, the motor is arranged in the base 210, and the motor is connected with the blade and the base 210 and drives the mowing blade 100 to drive the mowing blade 100 to rotate. The mowing blade 100 is typically disposed within a chassis beneath the base 210 and is rotated to cut vegetation. A power source is provided connected to the base 210 for providing power to the motor. The drive wheel 220 is coupled to the base 210 to effect movement of the mower 200. Alternatively, the driving wheel 220 may be pushed to move by power provided by a user, or the driving wheel 220 may be powered by a motor, so as to realize self-walking of the driving wheel 220.

Referring to fig. 3 to 4, the mowing blade 100 includes a center portion 110, a cutting portion 120, and an extension portion 130, the center portion 110 for connection with a motor of the mower 200. The mower 200 includes an output shaft connected to a motor, to which the mowing blade 100 is detachably attached. The output shaft extends from the inside of the base 210 to the underside of the base 210 to drive the rotation of the mowing blade 100. The central portion 110 is connected to an output shaft through which the cutting blade is driven to rotate when the motor is operated. The center of rotation 101 of the mowing blade 100 is disposed on the center portion 110, and the mowing blade 100 is rotatable about a first axis 102 passing through the center of rotation 101. The output shaft is connected to the mowing blade 100 at a rotation center 101 of the mowing blade 100, and the motor and the output shaft extend along a first axis 102 to drive the mowing blade 100 to rotate around the first axis 102. Alternatively, the mowing blade 100 is symmetrical with respect to the rotation center 101, and the cutting portions 120 are provided on both sides of the rotation center 101. The extension 130 includes a centerline 103 passing through the center of the body, and optionally, the body is substantially symmetrical about the centerline 103. In one embodiment, the centerline is located substantially in the middle of the body. Referring to fig. 3, a projection of the extension 130 in the axial direction of the first axis 102 extends along the center line 103.

Alternatively, the center line 103 is arranged perpendicular to the first axis 102, so that the extending direction of the cutting portion 120 is a radial direction of the first axis 102. The cutting part 120 includes a blade 121 to perform cutting. The extensions 130 connect the cutting portion 120 and the central portion 110, the extensions 130 are disposed at both sides of the rotation center 101, the extensions 130 are close to the first axis 102 with respect to the cutting portion 120 and extend outward in directions along the center line 103 toward both sides of the rotation center 101, and the extensions 130 are disposed between the central portion 110 and the cutting portion 120. The extension portion 130 extends downward in a direction away from the rotation center 101 along the center line 103 so that the cutting portion 120 has a height lower than that of the center portion 110 in the axial direction of the first axis 102, so that the cutting portion 120 can perform a cutting operation on vegetation at a low position and reduce collision of obstacles such as the ground against the center portion 110.

The extension 130 includes a main body 131 and a rib 132, and the rib 132 is provided on the main body 131 to reinforce the strength of the main body 131. The main body 131 constitutes a main part of the extending part 130, and the main body 131 referred to in the present invention should be regarded as a structure for removing the rib 132, such as removing the convex part of the rib 132, and filling the concave generated on the rib 132, so as to make the surface of the main body smooth. Additional structures such as protrusions on the surface of the extension 130 are not part of the body 131.

Optionally, the lateral ends of the extensions 130 are also provided with blades 121 for cutting vegetation.

When the mower 200 performs mowing operation, the working load of the mowing blade 100 mainly consists of cutting load generated by cutting vegetation and blade load generated by the mowing blade 100 when the blade rotates, so that the blade load is reduced, the cruising ability of the mower 200 can be effectively improved, and the actual cutting load ability of the blade is improved. In order to reduce the blade load, the extension 130 of the mowing blade 100 proposed by the present invention is designed to: when the mowing blade 100 is driven to rotate, the main body 131 is provided with an equivalent load area 1312 on any one first section 1311 in the radial direction of the first axis 102, the main body 131 is provided with at least one first section 1311 in the radial direction of the first axis 102, the ratio of the area of the first section 1311 to the area of the equivalent load area 1312 of the first section 1311 is set to be greater than or equal to 75%, and optionally, the ratio of the area of the first section 1311 to the area of the equivalent load area 1312 of the first section 1311 is set to be greater than or equal to 85%. Here, referring to fig. 6, the equivalent load region 1312 of the first cross section 1311 means that when the mowing blade 100 rotates about the first axis 102, the locus of the outermost edge of the first cross section 1311 of any one of the bodies 131 on the radial surface of the first axis 102 forms a circle centered on a point on the first axis 102, and defines the circle as the equivalent load circle 105. Referring to fig. 7, at any time, the segment of the equivalent load circle passing through the outermost edge of the first cross-section 1311 is the equivalent load region 1312 of the first cross-section 1311, and the area of the equivalent load region 1312 of the first cross-section 1311 affects the load of the first cross-section 1311 of the mowing blade 100 when the mowing blade 100 is in operation, i.e., the greater the area of the equivalent load region 1312, the greater the blade load generated by the mowing blade 100 when it is rotating. In order to ensure the strength of the mowing blade 100, the size of the mowing blade 100 cannot be excessively small. Therefore, by reducing the difference between the areas of the equivalent load regions 1312 corresponding to the first cross section 1311 and the first cross section 1311 of the mowing blade 100, the area of the equivalent load region 1312 is reduced to reduce the blade load when the mowing blade 100 rotates and effectively reduce the torque generated when the blade itself rotates, while ensuring the strength of the mowing blade 100. Here, blade loading is understood to be the load that the mower 200 generates when unloaded, carrying the mowing blade 100 along.

Referring to fig. 5, in a direction radial to the center line 103 and away from the center line 103, the extending portion 130 tends to extend downward (in the drawing, a direction perpendicular to the plane of the drawing and extending rearward of the plane is taken as downward), and in practice, the downward direction refers to a position of the driving wheel relative to the base, and the grass cutting portion is relatively located below the center portion. Referring to fig. 8a, 8b and 8c, there are at least three planes 106 passing through the first axis 102, and the cross-sections of the main body 131 in the planes 106 are substantially the same, where the same cross-section means the same shape and size of the cross-section, and the substantially same cross-section means that the extended shape of the cross-section is substantially uniform, and the difference in area of the cross-sections is less than 10% of the area. The difference in cross section caused by the deformation of the rib or the blade surface is the case where the cross sections are substantially the same. In the conventional grass cutting blade, the two planes with small included angles are basically the same in section, which is not the 'basically same' proposed by the invention. Optionally, there are at least three planes 106 passing through the first axis 102, and the included angle between each two planes 106 is greater than or equal to 2 degrees, and the cross section of the main body 131 in the planes 106 is substantially the same, and the cross section is defined as the second cross section 107, so that the difference between the areas of the equivalent load regions 1312 corresponding to the first cross section 1311 and the first cross section 1311 of the mowing blade 100 can be effectively reduced. Here, a plane 106 passing through the first axis 102 means that the first axis 102 is located within the plane 106, and the first axis 102 is an intersection of the three planes 106. The body 131 proposed by the present invention should be understood as a main part of the extension 130, and the addition or deletion of the deformation of the surface of the extension 130, or other structures, should not be considered as a body of the extension proposed by the present invention.

Optionally, the extension 130 and the cutting portion 120 are defined with a connecting line 108, the extension 130 and the cutting portion 120 are connected at the connecting line 108, either passing through the first axis 102 and cutting the plane of the connecting line 108, the cross-section of the body in the above plane being the same.

Referring to fig. 9a and 9b, the main body 131 includes a first segment 133 and a second segment 134 disposed on both sides of the tendon 132, and optionally, the tendon 132 passes through the centerline 103, and the first segment 133 and the second segment 134 are symmetrical with respect to the centerline 103. Each point of at least a portion of the first section 133 on an inner edge 1313 of the first cross-section 1311 perpendicular to the first axis 102 is equal to the vertical distance L1 of the first axis 102, and/or each point of at least a portion of the second section 134 on an edge of the first cross-section 1311 perpendicular to the first axis 102 is equal to the vertical distance L1 of the first axis 102. Here, the inner edge 1313 of the first section 1311 refers to the edge line of the first segment 133 near the rotation center 101, and the first section 1311 includes the outer edge line away from the rotation center 101, and the vertical distance between each point on the outer edge line and the first axis 102 is equal. The perpendicular distance between each point on the inner edge 1313 of the first cross-section 1311 and the first axis 102 is the perpendicular to the first axis from each point on the inner edge 1313 of the first cross-section 1311, and the length of the perpendicular. The structure of the body 131 is adapted to the rotational movement of the cutting blade such that the edge of the first cross-section 1311 of the body 131 coincides with the overall circular trajectory of the first cross-section 1311 as the mower 200 rotates, thereby taking full advantage of the space of the equivalent load zone 1312 corresponding to the first cross-section 1311 and reducing the blade load of the mowing blade 100 without reducing the overall strength of the mowing blade 100.

When the vertical distances between each point on the edge of the first section 1311 perpendicular to the first axis 102 and the first axis 102 are equal, the cut surface formed by the first section 1311 perpendicular to the first axis 102 of the at least part of the first section 133 when the mowing blade 100 rotates around the first axis 102 is a revolution surface with the first axis 102 as the rotation axis, so that when the mowing blade 100 rotates around the first axis 102, the cut surface formed by the first section 133 on the first section 1311 perpendicular to the first axis 102 is a circular ring surface.

Referring to FIG. 10, the body 131 includes an upper surface 135 and a lower surface 136, the upper surface 135 being the portion of the side of the first cone 104 that is centered on the first axis 102, and the lower surface 136 being the portion of the side of the second cone 105 that is centered on the first axis 102. Thus, the edges of the first section 133 in the first cross-section 1311 in the radial direction of the first axis 102 should be a line segment on the upper surface 135 and a line segment on the lower surface 136, respectively, the edges of the first cross-section 1311 being arcs of a circle centered at a point on the first axis 102. Similarly, the edges of the first section 1311 of the second section 134 in the radial direction of the first axis 102 should be a line segment on the upper surface 135 and a line segment on the lower surface 136, respectively, the edges of the first section 1311 being arcs of a circle centered at a point on the first axis 102. Optionally, the upper surface 135 and the lower surface 136 are equally spaced in any radial direction along the first axis 102, and the upper and lower edges of the first segment 133 are parallel arcs, thereby improving the balance of the cutting blade.

Optionally, the body 131 is configured to have at least a first cross-section 1311 radially of the first axis 102, the first cross-section 1311 coinciding with the equivalent load zone 1312 to reduce a blade load of the mowing blade 100. Alternatively, the body 131 is configured to have only a small area where any one of the first cross-sections 1311 in a radial direction of the first axis 102 coincides with its equivalent load area 1312, thereby improving the performance of the mower 200. Optionally, the mowing blade 100 is configured such that a first cross-section 1311 of any one of its extensions 130 in a radial direction of the first axis 102 coincides with its equivalent load area 1312.

Referring to fig. 11, the principle of the grass cutting blade 100 of the present invention to reduce the blade load will now be described in conjunction with the existing grass cutting blade 100 structure. The mowing blade 100 according to the present invention is classified as a first mowing blade, and the conventional mowing blade is classified as a second mowing blade 100 a. Referring to fig. 12 and 13, in the second extension of the second mowing blade 100a, in the radial direction of the first axis, the first cross section 1311a of the second extension is substantially rectangular or irregular (without the rib structure), and taking the rectangular shape as an example, the equivalent load area 1312a corresponding to the first cross section 1311a is a circular arc segment passing through four points of the outermost edge of the first cross section 1311a, that is, in the second mowing blade 100a, the area of the first cross section 1311a is smaller than the area of the corresponding equivalent load area 1312 a. At this time, since the insert is generally of a symmetrical design about the center line, the insert has at most two planes passing through the first axis, and the cross-sections of the body in the planes are the same. Referring to fig. 14 and 15, the area of the equivalent load ring 105a when the second cutting blade operates is larger than the area of the equivalent load ring 105 when the first cutting blade operates. Thus, the blade load of the second mowing blade 100a when operating is greater than the blade load of the first mowing blade when operating. According to experimental tests, the first mowing blade provided by the invention can reduce the blade load by 5% to 20% compared with the conventional second mowing blade, so that the endurance time of the mower can be prolonged, and the mowing performance of the mower can be improved.

The main body 131 extends along the center line 103 to both sides of the rotation center 101, and referring to fig. 16, the main body 131 includes a light-load section 137, the light-load section 137 has any one first section 1311 in the radial direction of the first axis 102, the ratio of the area of the first section 1311 to the area of the equivalent load region 1312 of the first section 1311 is set to be greater than or equal to 75%, and optionally, the ratio of the area of the first section 1311 to the area of the equivalent load region 1312 of the first section 1311 is set to be greater than or equal to 85%. The ratio of the length of the main body 131 in the direction of the center line 103 to the length of the light-load section 137 in the direction of the center line 103 is greater than or equal to 1 and less than or equal to 3, so as to improve the cruising of the mower 200 and improve the cutting performance of the mower 200.

Optionally, any one of the first cross-sections 1311 of the light-load section 137 in the radial direction of the first axis 102, the first cross-section 1311 coinciding with the equivalent load area 1312 corresponding to the first cross-section 1311.

Optionally, when the mowing blade 100 is driven to rotate, the cutting portion 120 has an equivalent load area 1312 on any one first section 1311 in the radial direction of the first axis 102, and the cutting portion 120 is configured to have at least one section in the radial direction of the first axis 102, and the ratio of the area of the section to the area of the equivalent load area of the section is set to be greater than or equal to 75%.

Optionally, the light-load section is configured as a segment on the mowing blade, and may be a segment in the extension direction of the center line, and the extension portion has a portion which is not the light-load section along the extension direction of the center line. Optionally, the light-load section is configured as a segment on the mowing blade, which may be a segment in a radial direction of the center line, and the extension has the light-load section and also has a non-light-load section in the radial direction of the center line, so that at least part of the upper surface of the main body is a portion of a side of a first cone with the first axis as an axis, and at least part of the lower surface of the main body is a portion of a side of a second cone with the first axis as an axis.

Alternatively, referring to fig. 17 and 18, the extension 130b includes only the main body 131b without a rib, and the structure of the main body 131b is also adapted to the description in the above embodiment.

Optionally, the extension further comprises a rib having at least three planes passing through the first axis, the rib body having the same cross-section in the planes, i.e. the rib is configured similarly to the body, to reduce blade loading of the rib when the blade is rotated.

The foregoing embodiments are merely illustrative of the principles and features of this invention, which is not limited to the above-described embodiments, but rather is susceptible to various changes and modifications without departing from the spirit and scope of the invention, which changes and modifications are within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims (10)

1. A grass cutting blade rotatable about a first axis, comprising:

a cutting part including a blade to perform cutting;

an extension portion that is close to the first axis with respect to the cutting portion, the extension portion including a main body that constitutes a main portion of the extension portion,

characterized in that the extension is arranged to:

there are at least three planes passing through the first axis, the cross-section of the body in the planes being substantially the same.

2. The grass cutting blade of claim 1, wherein:

the body comprises a first section and a second section which are arranged on two sides of the center line of the body, the vertical distance between each point of at least part of the first section on the inner edge of the cross section perpendicular to the first axis and the first axis is equal, and/or the vertical distance between each point of at least part of the second section on the edge of the cross section perpendicular to the first axis and the first axis is equal.

3. The grass cutting blade as claimed in claim 2, wherein:

the main body comprises a first section and a second section which are arranged on two sides of the center line, and a cutting surface which is formed when the mowing blade rotates around the first axis on at least part of the section of the first section which is perpendicular to the first axis is a revolution surface taking the first axis as a rotation axis.

4. The grass cutting blade as claimed in claim 1,

the body includes an upper surface that is part of a side of a first cone with the first axis as an axis and a lower surface that is part of a side of a second cone with the first axis as an axis.

5. The grass cutting blade as claimed in claim 4, wherein:

the upper surface and the lower surface are equally spaced in any radial direction along the first axis.

6. The grass cutting blade of claim 1, wherein: when the mowing blade is driven to rotate, the main body has an equivalent load area on any cross section in the radial direction of the first axis, the main body is provided with at least one cross section in the radial direction of the first axis, and the ratio of the area of the cross section to the area of the equivalent load area is set to be greater than or equal to 75%.

7. The grass cutting blade as claimed in claim 6, wherein: the first or second section is configured to have at least one cross-section radial to the first axis that coincides with the equivalent load area.

8. The grass cutting blade as claimed in claim 6, wherein:

the main body comprises a light-load section, the ratio of the area of any one section of the light-load section in the radial direction of the first axis to the area of an equivalent load area of the section is set to be greater than or equal to 75%, and the ratio of the length of the main body in the direction of the center line of the main body to the length of the light-load section in the direction of the center line of the main body is greater than or equal to 1 and less than or equal to 3.

9. The grass cutting blade as claimed in claim 6, wherein:

the main body comprises a light-load section, and any one section of the light-load section in the radial direction of the first axis is overlapped with the equivalent load area corresponding to the section.

10. A lawnmower comprising the grass cutting blade of any one of claims 1 to 9, and further comprising:

a base connected to the mowing blade;

a motor for driving the mowing blade to rotate around the first axis;

a power supply for supplying power to the motor;

and the driving wheel drives the base to walk.

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