CN113115623A

CN113115623A - Cutting blade for mower and mower

Info

Publication number: CN113115623A
Application number: CN202010027123.XA
Authority: CN
Inventors: 刘天亮
Original assignee: Nanjing Deshuo Industrial Co Ltd
Current assignee: Nanjing Chervon Industry Co Ltd; Nanjing Deshuo Industrial Co Ltd
Priority date: 2020-01-10
Filing date: 2020-01-10
Publication date: 2021-07-16

Abstract

The invention discloses a cutting blade for a mower and the mower, belonging to the technical field of mowers, wherein the cutting blade is configured to rotate around a rotating shaft in a rotating plane and comprises a supporting part and a cutting part, and the supporting part is fixed on the rotating shaft; the front edge of the cutting part is provided with a cutting edge, the cutting part comprises a first cutting part and a second cutting part, one end of the second cutting part is connected with the supporting part, and the other end of the second cutting part is connected with the first cutting part; the first cutting portion is provided with N sections along the radial direction, each section is provided with a bending center, the sections are bent and twisted at the corresponding bending center, an attack angle is formed between a chord line of each section and the rotating plane, the attack angles are increased progressively from inside to outside along the radial direction, so that the suction force generated by the rotation of the cutting blade is improved, and the pneumatic performance of the blade is improved. The mower comprises the cutting blade, the cutting blade generates ascending air flow to drive the chopped grass to ascend and enter the grass collecting box of the mower, and the mowing efficiency is improved.

Description

Cutting blade for mower and mower

Technical Field

The invention relates to the technical field of mowers, in particular to a cutting blade for a mower and the mower.

Background

In the garden industry, lawn mowers are used as basic tools for lawn trimming, and simple, efficient and quality-guaranteed mowing operation is required. Most of the existing lawn mowers are rotary type lawn mowers, i.e., upper blades of grass are rotated at high speed by blades to cut grass stems or blades into shorter pieces and to convey the crushed grass or grass clippings to an outlet of the lawn mower. On the existing blade, the section shape of the cutting part has the same attack angle to the incoming airflow, and the aerodynamic performance of the blade is poor, so that the mowing efficiency is low.

Disclosure of Invention

The invention aims to provide a cutting blade for a mower and the mower, and aims to solve the technical problems of poor pneumatic performance and low mowing efficiency of the blade in the prior art.

As the conception, the technical scheme adopted by the invention is as follows:

a cutting blade for a lawn mower configured to rotate about a rotational axis in a plane of rotation, the cutting blade comprising:

a support part fixed on the rotating shaft;

a cutting part, the front edge of which is provided with a cutting edge, the cutting part comprises a first cutting part and a second cutting part, one end of the second cutting part is connected with the supporting part, and the other end of the second cutting part is connected with the first cutting part; the first cutting part is provided with N sections along the radial direction, each section is provided with a bending center, the sections are bent at the corresponding bending centers, the chord lines of the sections and the rotating plane form attack angles, the attack angles are increased from inside to outside along the radial direction, and the adjacent sections are connected smoothly; wherein N is greater than or equal to 2.

Wherein a ratio of a difference in the angles of attack of adjacent ones of the cross sections to a length of the first cutting portion between adjacent ones of the cross sections in a radial direction is 0.1 to 0.5 degrees/cm.

Wherein a trailing edge of the first cutting portion is raised relative to a leading edge of the first cutting portion, and a line segment between a point of the tip of the cutting edge and the trailing edge on each of the cross sections is the chord line.

Wherein, the point of the blade tip of the blade on each section is the center of the bending torsion.

The rotating plane and the rotating shaft are provided with an intersection point, and the projection of the intersection point on the cross section is the bending center.

The sections are divided at equal intervals along the radial length of the first cutting portion, the attack angles of the sections are increased in an equal difference mode from inside to outside in the radial direction.

The sections are divided at equal intervals along the radial length of the first cutting portion, the sections are radially from inside to outside, and the difference of the attack angles of the adjacent sections is in an increasing trend.

Wherein the angle of attack is between 2 and 30 degrees.

The two ends of the supporting part are provided with the cutting parts, and the two cutting parts are centrosymmetric relative to the rotating shaft.

A lawnmower comprising a cutting blade as described above, further comprising:

a chassis formed with an accommodating space accommodating the cutting blade;

a motor for driving the cutting blade to rotate around a rotating shaft;

a power supply for providing power to the motor.

The invention has the beneficial effects that:

the cutting blade for the mower is configured to rotate around a rotating shaft in a rotating plane, the front edge of the cutting part is provided with a cutting edge for realizing cutting operation, the cutting part comprises a first cutting part and a second cutting part, one end of the second cutting part is connected with the supporting part, and the other end of the second cutting part is connected with the first cutting part; the first cutting part is provided with N sections along the radial direction, each section is provided with a bending center, the sections are bent and twisted by the corresponding bending center, an attack angle is formed between a chord line of each section and a rotating plane, the attack angles are increased progressively from inside to outside along the radial direction, adjacent sections are connected smoothly, the suction force generated by rotation of the cutting blade is improved, the pneumatic performance of the blade is improved, ascending air flow can be generated to drive grass chippings to ascend and enter a grass collecting box of the mower when the cutter is used, and the mowing efficiency is improved.

Drawings

FIG. 1 is a first schematic structural diagram of a lawn mower according to an embodiment of the present invention;

FIG. 2 is a second schematic structural view of a lawn mower according to an embodiment of the present invention;

FIG. 3 is a schematic view of the structure of the chassis and cutting blade of the mower provided by the embodiment of the present invention;

FIG. 4 is a first schematic view of a cutting blade according to an embodiment of the present invention;

FIG. 5 is a second schematic structural view of a cutting blade according to an embodiment of the present invention;

FIG. 6 is a side view of a cutting insert provided by an embodiment of the present invention;

FIG. 7 is a front view of a cutting blade provided by an embodiment of the present invention;

FIG. 8 is a cross-sectional view taken along line A-A of FIG. 7;

FIG. 9 is a sectional view taken along line B-B of FIG. 7;

FIG. 10 is a cross-sectional view taken along line C-C of FIG. 7;

FIG. 11 is a cross-sectional view taken along line D-D of FIG. 7;

FIG. 12 is a cross-sectional view taken along line E-E of FIG. 7;

FIG. 13 is a sectional view taken along line F-F of FIG. 7;

FIG. 14 is a sectional view taken along line G-G of FIG. 7;

FIG. 15 is a sectional view taken along line H-H of FIG. 7;

FIG. 16 is a cross-sectional view taken along line I-I of FIG. 7;

fig. 17 is a sectional view taken along the direction J-J of fig. 7.

In the figure:

10. a cutting blade; 20. a hand-held portion; 30. a wheel; 40. a chassis; 401. a grass collecting port;

101. a support portion;

102. a cutting section; 1021. a first cutting portion; 1022. a second cutting part;

103. a blade.

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.

In the description of the present invention, unless expressly stated or limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, e.g., as meaning permanently connected, removably connected, or integral to one another; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

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

Embodiments of the present invention provide a lawnmower, and a motor-driven walk-behind lawnmower will be described as an example. Referring to fig. 1 to 3, the lawn mower includes a handheld portion 20, wheels 30, a chassis 40, a motor, a power source and a cutting blade 10 for the lawn mower, wherein the wheels 30 are connected with the chassis 40, the wheels 30 rotate by the thrust of the handheld portion 20 to realize walking of the lawn mower, a receiving space for receiving at least part of the cutting blade 10 is formed at the bottom of the chassis 40, the cutting blade 10 can rotate around a rotation axis as an axis under the driving of the motor to perform a cutting function of the lawn mower, the power source provides a power source for the motor, and the power source can be an alternating current power source or a direct current power source.

The mower further comprises a rotating shaft for driving the cutting blade 10 to rotate, and the motor is connected to the rotating shaft. The motor comprises a motor shaft, and the rotating shaft can be a motor shaft or other shaft bodies which are not the motor shaft. When the axis of rotation is the motor axis, the motor directly drives the cutting blade 10. When the rotating shaft is not a motor shaft, a transmission mechanism is arranged between the motor and the cutting blade 10 for transmission. The motor and the rotating shaft form coaxial rotation or non-coaxial rotation. The mower also includes a fan connected to the rotatable shaft, the fan rotating about an axis parallel to or coincident with the rotatable shaft.

The lawn mower also comprises a grass collecting box, wherein a grass collecting opening 401 is formed in the chassis 40, the grass collecting opening 401 is communicated with the grass collecting box, and when the cutting blade 10 rotates, the air flow which rises can be generated to drive the broken grass to rise through the grass collecting opening 401 to enter the grass collecting box.

Referring to fig. 4 to 17, the cutting blade 10 is configured to rotate about a rotation axis and form a rotation plane, and the cutting blade 10 includes a supporting portion 101 and a cutting portion 102, and the supporting portion 101 is fixed to the rotation axis, that is, an axis of the supporting portion 101 coincides with an axis of the rotation axis. The cutting part 102 is connected with the supporting part 101, the front edge of the cutting part 102 is provided with a blade 103 for realizing cutting operation, the cutting part 102 comprises a first cutting part 1021 and a second cutting part 1022, one end of the second cutting part 1022 is connected with the supporting part 101, and the other end is connected with the first cutting part 1021; the first cutting part 1021 is provided with N sections along the radial direction, each section is provided with a bending center, the sections are bent and twisted at the corresponding bending center, an attack angle is formed between a chord line of each section and a rotating plane, the attack angles are increased progressively from inside to outside along the radial direction, and adjacent sections are connected smoothly; wherein N is greater than or equal to 2. The angle of attack increases progressively and can promote the rotatory produced suction of cutting blade 10, improves the aerodynamic performance of cutting blade 10 for cutting blade 10 can produce the updraft and drive the garrulous grass and rise and get into the grass-collecting box of lawn mower when using, improves mowing efficiency.

Equivalently, the flat first cut part 1021 has N sections in the radial direction, each section having a bending center, and the flat section is bent with respect to the bending center such that the chord line of the section forms an angle of attack with the rotation plane. In fig. 5, the arrow indicates the rotation direction of the cutting blade 10, and in fig. 6, S indicates the rotation plane and T indicates the rotation axis.

The sectional twisting causes the trailing edge of the first cutting part 1021 to be raised with respect to the leading edge of the first cutting part 1021, and a line segment between the point of the blade tip and the trailing edge of the blade edge 103 in each section is a chord line.

The selection of the bending center on each section is not limited, as long as the smooth connection between adjacent sections is ensured after the sections are bent and twisted, and the attack angles are increased progressively from inside to outside along the radial direction.

The point of the blade edge 103 on each cross section may be the center of the kink. The rotation plane and the rotation axis may have an intersection point, and a projection of the intersection point on the cross section may be a bending center. The intersection of the plane of rotation and the axis of rotation is denoted by O in fig. 6.

Only the first cutting portion 1021 is bent, not the whole cutting portion 102, which has the following advantages: if the whole cutting part 102 is twisted, in order to adjust a large attack angle, the tail end of the cutting part 102 is warped seriously and easily collides with the chassis 40 of the mower, and the first cutting part 1021 is only a part of the whole cutting part 102, so that even if the attack angle is adjusted to be large, the tail end of the first cutting part 1021 is warped and cannot collide with the chassis 40, the adjustable area of the cutting blade 10 is reduced, and the production is facilitated.

During operation, the blade 103 firstly cuts the grass cover, the curved surface of the cutting part 102 sweeps the grass, and the lift force is formed to send the grass into the grass collecting opening 401 of the chassis 40 of the mower.

The attack angle is 2-30 degrees, so that the airflow flows smoothly, the phenomenon that the airflow is blocked by too steep surface of the cutting part 102 is avoided, the airflow smoothly flows upwards along the cutting part 102, and the broken grass is driven to rise.

The first cutting portion 1021 has a radially inner side and a radially outer side, the radially inner side being connected to the second cutting portion 1022, and the radially outer side having the largest angle of attack. Since the linear velocity of the outer peripheral surface of the first cutting section 1021 is maximized, the suction force generated by the rotation of the cutting blade 10 can be greatly increased. In fig. 10, the angle of attack is denoted by a.

The angle of attack grow makes the lift that corresponding cutting portion 102 obtained grow, when using, because the position of cutting blade 10 is unchangeable, on the contrary the effort grow of cutting blade 10 to the air current, the vertical upward flow speed of air current below cutting portion 102 accelerates, and the air current static pressure reduces, and the suction to leaf or grass grow to produce the air current that rises and drive the garrulous grass rising.

The first cutting portion 1021 may be divided into N sections in the radial direction, and N may be 2 or more. In this embodiment, N is equal to 5 as an example. The progressive bending among the plurality of sections which are arranged in sequence can adjust the bending coefficient of each section according to the lifting force requirement, particularly the attack angle of the outer peripheral surface is greatly adjusted, so as to improve the suction force generated by the rotation of the cutting blade 10.

Since the angle of attack is gradually increased from the inside to the outside in the radial direction of the first cutting portion 1021, a difference necessarily exists between the angles of attack of two adjacent sections. The ratio of the difference of the angles of attack of the adjacent sections to the length of the first cutting part 1021 in the radial direction between the adjacent sections is 0.1-0.5 degrees/cm, so that the bending and twisting of the first cutting part 1021 are uniform, and the generated lift force is uniform.

On one cutting blade 10, the ratio of the difference in the angle of attack of the adjacent sections of the first cutting part 1021 to the length of the first cutting part 1021 in the radial direction between the adjacent sections may be a fixed value, for example, 0.2 degrees/cm, that is, the ratio of the difference in the angle of attack between the nth section and the (n + 1) th section to the length of the first cutting part 1021 in the radial direction between the nth section and the (n + 1) th section is 0.2 degrees/cm, n being 1.

It is also possible that, on one cutting blade 10, a ratio of a difference in an angle of attack of adjacent sections of the first cutting part 1021 to a length of the first cutting part 1021 in the radial direction between the adjacent sections is not constant, for example, a ratio of a difference in an angle of attack between an nth section and an n +1 th section to a length of the first cutting part 1021 in the radial direction between the nth section and the n +1 th section is 0.2 degrees/cm, a ratio of a difference in an angle of attack between an n +1 th section and an n +2 th section to a length of the first cutting part 1021 in the radial direction between the n +1 th section and the n +2 th section is 0.3 degrees/cm, and n is 1.

If the ratio of the difference in the angle of attack between the adjacent sections to the length of the first cut part 1021 in the radial direction between the adjacent sections is 0.1 degrees/cm, when the respective sections are divided at equal intervals along the length of the first cut part 1021 in the radial direction, for example, one section is divided at intervals of 1 cm, the difference in the angle of attack between the adjacent two sections is 0.1 degrees. If a section is divided every 2 cm apart, the difference in angle of attack between two adjacent sections is 0.2 degrees.

If the ratio of the difference in the angle of attack between the adjacent sections to the length of the first cutting portion 1021 in the radial direction between the adjacent sections is 0.1 degrees/cm, when the respective sections are not divided at equal intervals in the radial length of the first cutting portion 1021, for example, the length of the first cutting portion 1021 in the radial direction between the 1 st section and the 2 nd section is 1 cm, and the length of the first cutting portion 1021 in the radial direction between the 2 nd section and the 3 rd section is 2 cm, the difference in the angle of attack between the 1 st section and the 2 nd section is 0.1 degrees, and the difference in the angle of attack between the 2 nd section and the 3 rd section is 0.2 degrees.

The size of the angle of attack of each section can be set according to actual needs. Each section may be divided at equal intervals along the radial length of the first cutting portion 1021, and the values of the angles of attack of the sections increase in an equal difference from inside to outside in the radial direction, and the angles of attack of the sections increase uniformly. For example, if the angle of attack of the 1 st cross section is 3 degrees and the angle of attack of the 2 nd cross section is 5 degrees, the angle of attack of the 3 rd cross section is 7 degrees.

Alternatively, each section may be divided at equal intervals along the radial length of the first cutting portion 1021, and the difference between the angles of attack of adjacent sections may increase from inside to outside in the radial direction. For example, the angle of attack of the 1 st cross section is 3 degrees, the angle of attack of the 2 nd cross section is 5 degrees, the angle of attack of the 3 rd cross section is 8 degrees, the difference between the angle of attack of the 1 st cross section and the angle of attack of the 2 nd cross section is 2 degrees, the difference between the angle of attack of the 2 nd cross section and the angle of attack of the 3 rd cross section is 3 degrees, and so on, the trend is increased.

No matter how the size of the attack angle of each cross section is set, it is only required to ensure that the attack angle gradually increases from inside to outside along the radial direction of the first cutting portion 1021, and the included angle between the chord at the outermost periphery of the first cutting portion 1021 and the rotation plane is the largest.

Both ends of supporting part 101 all are provided with cutting portion 102, and two cutting portions 102 are central symmetry for the axis of rotation for cutting blade 10 is central symmetry structure, and the atress is balanced when being rotatory for cutting blade 10. The cutting area can be increased by the arrangement of the two cutting parts 102, and the cutting efficiency is further improved.

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

1. A cutting blade for a lawn mower configured to rotate about a rotational axis in a plane of rotation, the cutting blade comprising:

a support part (101) fixed to the rotating shaft;

a cutting part (102) having a blade (103) at a front edge thereof, the cutting part (102) including a first cutting part (1021) and a second cutting part (1022), one end of the second cutting part (1022) being connected to the support part (101), and the other end thereof being connected to the first cutting part (1021);

the first cutting part (1021) is provided with N sections along the radial direction, each section is provided with a bending center, the sections are bent and twisted at the corresponding bending center, the chord lines of the sections and the rotating plane form attack angles, the attack angles are increased from inside to outside along the radial direction, and the adjacent sections are connected smoothly; wherein N is greater than or equal to 2.

2. A cutting blade for a lawn mower according to claim 1, wherein a ratio of a difference in the angle of attack of adjacent said sections to a length of said first cutting portion (1021) between adjacent said sections in a radial direction is 0.1-0.5 degrees/cm.

3. A cutting blade for a lawn mower as claimed in claim 2, wherein a trailing edge of the first cutting portion (1021) is raised with respect to a leading edge of the first cutting portion (1021), and a line segment between a nose point of the cutting edge (103) and the trailing edge on each of the sections is the chord line.

4. A cutting blade for a lawn mower according to claim 2, wherein a point of a tip of said cutting edge (103) on each of said cross sections is said center of kink.

5. The cutting blade for a lawnmower according to claim 2, wherein the plane of rotation has an intersection point with the axis of rotation, the projection of the intersection point on the cross section being the center of the kink.

6. A cutting blade for a lawn mower according to claim 2, wherein each of said sections is divided at equal intervals along a radial length of said first cutting portion (1021), and said angle of attack increases in value with equal difference from radially inside to radially outside.

7. A cutting blade for a lawn mower as claimed in claim 2, wherein each of said sections is divided at equal intervals along a radial length of said first cutting portion (1021), and a difference between adjacent ones of said angles of attack increases from inside to outside in a radial direction.

8. A cutting blade for a lawn mower as claimed in any one of claims 1 to 7, wherein said angle of attack is between 2 degrees and 30 degrees.

9. A cutting blade for a lawn mower according to any one of claims 1-7, wherein both ends of the support portion (101) are provided with said cutting portions (102), and both said cutting portions (102) are centrosymmetric with respect to the rotational axis.

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

a chassis formed with an accommodating space accommodating the cutting blade;

a motor for driving the cutting blade to rotate around a rotating shaft;

a power supply for providing power to the motor.