WO2023124380A1 - 刀片及割草机 - Google Patents

刀片及割草机 Download PDF

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Publication number
WO2023124380A1
WO2023124380A1 PCT/CN2022/124824 CN2022124824W WO2023124380A1 WO 2023124380 A1 WO2023124380 A1 WO 2023124380A1 CN 2022124824 W CN2022124824 W CN 2022124824W WO 2023124380 A1 WO2023124380 A1 WO 2023124380A1
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WIPO (PCT)
Prior art keywords
blade
raised portion
radial direction
rate
change
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PCT/CN2022/124824
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English (en)
French (fr)
Inventor
张宇浩
杨青松
许海深
Original Assignee
南京泉峰科技有限公司
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Application filed by 南京泉峰科技有限公司 filed Critical 南京泉峰科技有限公司
Publication of WO2023124380A1 publication Critical patent/WO2023124380A1/zh

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    • A—HUMAN NECESSITIES
    • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
    • A01D—HARVESTING; MOWING
    • A01D34/00—Mowers; Mowing apparatus of harvesters
    • A—HUMAN NECESSITIES
    • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
    • A01D—HARVESTING; MOWING
    • A01D34/00—Mowers; Mowing apparatus of harvesters
    • A01D34/01—Mowers; Mowing apparatus of harvesters characterised by features relating to the type of cutting apparatus
    • A01D34/412—Mowers; Mowing apparatus of harvesters characterised by features relating to the type of cutting apparatus having rotating cutters
    • A01D34/63—Mowers; Mowing apparatus of harvesters characterised by features relating to the type of cutting apparatus having rotating cutters having cutters rotating about a vertical axis
    • A01D34/73—Cutting apparatus

Definitions

  • the present application relates to the technical field of mowing equipment, for example, to a blade and a lawnmower.
  • a lawn mower is a mechanical tool used to trim lawns, vegetation, etc., and is also called a weeder, lawnmower, or lawn trimmer.
  • Lawn mowers in the related art mostly use rotating blades to rotate and cut the grass.
  • Some users use the lawn mower together with a grass collection bag, so that the cut grass can be absorbed into the grass collection bag of the lawn mower.
  • Centralized storage is carried out in order to realize the centralized treatment in the later stage; some users also allow the cut grass clippings to scatter freely as an organic fertilizer to provide nutrients for the lawn.
  • the present application provides a blade applicable to a lawnmower and the lawnmower, which optimize the aerodynamic performance of the blade without increasing the rotational speed of the blade, thereby improving the grass-cutting performance of the blade.
  • a blade suitable for a mower comprising: a base extending radially of the blade, the blade is configured to rotate around a first axis on the base when driven by the mower;
  • the part is formed by extending outward from the base;
  • the raised part includes the connected first raised part and the second raised part, and the first raised part is farther away from the first axis than the second raised part;
  • the raised part The angle formed between the tangent line at any point on the first edge line of the upper surface of the upper surface and the first plane perpendicular to the first axis is the exit angle, and in the radial direction along the blade, the second tilt
  • the rate of change of the exit angle on the portion is greater than the rate of change of the exit angle on the first raised portion.
  • the exit angle varies continuously along the radial direction of the blade.
  • the length of the second raised portion is greater than the length of the first raised portion.
  • the rate of change of the cocked length of the second cocked portion is greater than the rate of change of the cocked length of the first cocked portion.
  • the first boundary line of the raised portion is projected on the first plane to form a first curve, and the absolute value of the slope at any point of the second raised portion on the first curve is greater than that at the first curved line. The absolute value of the slope at any point on the lift.
  • the path formed when starting from the root of the raised portion and transitioning to the first edge line is a curved curve.
  • the raised portion further includes a transition portion connected to the second raised portion and closer to the base than the second raised portion, the exit angle of the second raised portion changes along the radial direction of the blade The rate is greater than the rate of change of the exit angle of the transition along the radial direction of the blade.
  • the exit angle of the first tilting portion is between 30° and 40°; the exit angle of the second tilting portion is between 20° and 35°;
  • the present application also provides a lawnmower, which includes the above-mentioned blade.
  • the lawn mower includes an additional second blade in addition to the blade.
  • Fig. 1 is the schematic diagram of mower
  • Fig. 2 is a schematic diagram of the lawn mower from a perspective where the blade can be seen;
  • Fig. 3 is a three-dimensional schematic diagram of a blade suitable for the above-mentioned lawnmower
  • Fig. 4 is the schematic diagram of above-mentioned blade under another angle of view
  • Fig. 5 is the front view of the blade shown in Fig. 3;
  • Figure 6 is a top view of the blade shown in Figure 3;
  • Figure 7 is a schematic illustration of a portion of the blade shown in Figure 3.
  • Figure 8 is a right side view of the blade shown in Figure 3;
  • Fig. 9 is a partially enlarged view of the raised portion in the right view in Fig. 8;
  • Fig. 10 is a partially enlarged view of the front view shown in Fig. 5;
  • Fig. 11 is a partially enlarged view of the top view shown in Fig. 6;
  • Fig. 18 is a partial enlarged view of the raised portion in the right view in Fig. 8;
  • Fig. 19 is a schematic diagram of force analysis of the blade shown in Fig. 7;
  • Figure 20 is a schematic diagram of an embodiment of the blade shown in Figure 7;
  • FIG. 21 is a schematic view of another embodiment of the blade shown in FIG. 7 .
  • the blades involved in this application are usually used in lawnmowers, and a hand-pushable lawnmower 10 will be taken as an example below. It will be appreciated that the lawn mower may also be a riding lawn mower.
  • the blade of a lawn mower is usually designed to include a cutting part and a tilting part that forms a certain angle with the cutting part.
  • the cutting part is responsible for cutting off the grass that needs to be cut.
  • the grass clippings cut by the cutting part move upward when subjected to the lift force, so that when the grass clippings fall down, they can be cut again by the blade.
  • the advantage of this is that grass clippings that have been cut twice are usually finer than grass clippings that have only been cut once.
  • some blades are set to rotate at a relatively high speed, which on the one hand increases the lift formed when the blade rotates, so that the grass clippings cut for the first time are lifted to a higher height;
  • the cutting frequency of the blade to the grass cuttings is improved, and the grass cuttings falling from a high place can be cut by the rotating blade again.
  • running the blades at a higher RPM can make the blades use too much energy, requiring the mower to recharge more frequently, or affecting the amount of grass that can be cut with the same amount of power or oil.
  • the higher blade rotation speed makes the blade rotation generate more noise, which affects the user experience instead.
  • the applicant tries to improve the lift formed on the surface of the blade while keeping the blade at a reasonable rotational speed, so that the grass clippings that have been cut once can stay in the air for a longer time before falling to the ground, so as to improve the rate of being cut again. probability, so the following technical solutions are produced.
  • lawnmower 10 comprises handle 60, chassis 20, wheel 40 and blade 30, lawnmower 10 can also comprise power source and transmission mechanism etc., power source cooperates with transmission mechanism, drives wheel 40 Rotate and drive the blade 30 to rotate.
  • the blade 30 is located in the accommodation space formed by the chassis 20 to illustrate that the first rotation direction R rotates around the rotation center 110 .
  • the lawn mower involved in the figure also includes a grass bag 50 installed on the lawn mower 10 , and the grass cut by the blade 30 enters the grass bag 50 through the grass discharge channel 21 on the chassis 20 .
  • the grass collecting bag 50 is not a necessity of the lawnmower 10.
  • the blade 30 includes a base portion 200 , a cutting portion 300 and a lift portion 400 .
  • the base portion 200 extends to both sides along the radial direction of the blade 30 , and extends to the cutting portion 300 .
  • the upper surface of the base 200 includes a front boundary 201 and a rear boundary 202, and in this embodiment, both the front boundary 201 and the rear boundary 202 are substantially parallel to the radial direction of the blade.
  • the cutting part 300 is the main working part for realizing the cutting function when the blade 30 performs the cutting operation, and most of the objects to be cut are cut by the cutting part 300 shown in FIG. 3 .
  • the blade 30 further includes at least one tilting portion 400 , the tilting portion 400 is located at the end of the blade 30 , and the tilting direction of the tilting portion 400 faces away from the cutting portion 300 .
  • the shape of the raised portion 400 can be seen more clearly from another perspective.
  • Fig. 5 and Fig. 6 are respectively the schematic view obtained when the blade 30 is viewed from the front side and directly above the direction coordinates specified in Fig.
  • the blade 30 rotates around the first axis 101 passing through the center of rotation 110, the cutting portion 300 of the blade 30 is divided into a first cutting portion 310 and a second cutting portion 320, and the first cutting portion 310 is closer to the second cutting portion 320 than the second cutting portion 320. Therefore, when the blade 30 rotates, the first cutting part 310 can cut lower grass than the second cutting part 320 .
  • the first cutting portion 310 is substantially parallel to the base portion 200
  • the second cutting portion 320 has a certain arc, and smoothly transitions from the base portion 200 to the first cutting portion 310 .
  • the front boundary 201 and the rear boundary 202 of the base 200 are not necessarily a single straight line, but may also be a combination of multiple straight lines such as arcs or tooth shapes.
  • the shape of the base 200 is not the core of this application , the discussion is continued here in the form of a common base 200 in the related art, that is, the front boundary 201 and the rear boundary 202 of the base 200 of the blade 30 are substantially parallel to the radial direction of the blade 30 .
  • a first straight line 211 extending along the radial direction of the blade 30 is defined.
  • the first straight line 211 passes through the rotation center 110 of the blade 30 and is located on the upper surface of the blade.
  • a second straight line 212 substantially perpendicular to the radial direction of the blade 30 is defined, the second straight line 212 passes through the center of rotation 110 of the blade 30 and is located on the upper surface of the blade.
  • the first straight line 211 is substantially perpendicular to the second straight line 212 .
  • the blade 30 has a length direction and a width direction
  • the base 200 is substantially symmetrical about the first straight line 211, and is also substantially symmetrical about the second straight line 212
  • the direction of the first straight line 211 is parallel to the length direction of the blade 30
  • the second straight line 212 is parallel to the width direction of the blade 30 .
  • the raised portion 400 comprises a first raised portion 410 connected to a second raised portion 420 , the first raised portion 410 being farther away from the first axis 101 than the second raised portion 420 .
  • the boundary line between the first raised portion 410 and the second raised portion 420 basically extends along the boundary line between the first cutting portion 310 and the second cutting portion 320.
  • the dotted lines are artificially added schematic lines to better show the various parts of the raised portion 400 , and are not actual lines in the blade 30 . In an actual product, each part of the raised portion 400 transitions smoothly, and no clear outline can be formed to distinguish the boundary of each part.
  • the length of the second raised portion 420 is greater than the length of the first raised portion 410.
  • the raised portion 400 may further include a transition portion 430 for transitioning from the second raised portion 420 to the base portion 200 .
  • a first plane 240 is defined, which is perpendicular to the first axis 101 and passes through the center point of the center of rotation 110 of the blade 30 .
  • the upper surface of the base part 200 is located on the first plane 240
  • the first cutting part 310 of the cutting part 300 is substantially parallel to the first plane 240 .
  • FIG. 9 is a partially enlarged view of the raised portion 400 in FIG. 8 .
  • the raised portion 400 forms two boundary lines on the upper surface of the blade, which are respectively a first boundary line 441 and a second boundary line 442 shown in FIG. 8 .
  • the first boundary line 441 is located on the other side opposite to the cutting portion 300 of the blade 30, that is, the rear side in the direction coordinates specified in FIG. .
  • the tangent line formed at a certain point on the first boundary line 441 of the upper surface of the raised portion 400 is the same as the first boundary line 441.
  • the angle between one plane 240 is the exit angle ⁇ . Since the first cutting portion 310 is substantially parallel to the first plane 240, the tangent line formed at a certain point on the first boundary line 441 of the upper surface of the raised portion 400 shown in FIG.
  • the angle between the planes is equal to the outlet angle ⁇ defined here, and a series of different outlet angles ⁇ are formed starting from different points on the first boundary line 441 .
  • the outlet angle ⁇ needs to be located on the surface where the raised portion 400 bends toward the cutting portion 300 , in this embodiment, that is, the upper surface of the blade 30 .
  • FIG. 9 also shows the uplifting distance L of the uplifting portion 400 , which is the distance from the root of the uplifting portion 400 to the first boundary line 441 .
  • the uplifted root refers to the "boundary line” that passes when transitioning from the cutting part 300 to the uplifted part 400 .
  • the lift distance L refers to the surface where the lift portion 400 deflects toward the cutting portion 300 , that is, the upper surface of the blade 30 .
  • Fig. 10 and Fig. 11 enlarge one end of the front view and the top view of the blade 30 shown in Fig. 5 and Fig. 6 respectively , and randomly search for a series of points on the first boundary line 441 of the raised part 400, respectively: the first point 401 and the second point 402 on the first raised part 410, the first point 402 on the second raised part 420 The third point 403 and the fourth point 404 , and the fifth point 405 and sixth point 406 on the transition 430 .
  • the characteristic of this series of points is that the distance between the two points on each part of the raised portion 400 along the radial direction of the blade 30 is equal, that is, the distance along the direction of the first straight line 211 is equal. That is to say, along the direction of the first straight line 211, the distance between the first point 401 and the second point 402 is equal to the distance between the third point 403 and the fourth point 404, and also equal to the distance between the fifth point 405 and the sixth point 405. The distance between points 406 .
  • FIG. 12 is a cross-sectional view taken along A-A at the first point 401, and the first point 401 forms a first tilting distance L1 and a first exit angle ⁇ 1.
  • FIG. 13 is a cross-sectional view obtained by cutting the second point 402 along B-B. The second point 402 forms a second tilting distance L2 and a second exit angle ⁇ 2.
  • FIG. 14 is a cross-sectional view taken along C-C at the third point 403, where the third point 403 forms a third lift distance L3 and a third exit angle ⁇ 3.
  • FIG. 15 is a cross-sectional view of the fourth point 404 cut along D-D, and the fourth point 404 forms a fourth tilting distance L4 and a fourth exit angle ⁇ 4.
  • FIG. 16 is a cross-sectional view of the fifth point 405 taken along E-E.
  • the fifth point 405 forms a fifth tilting distance L5 and a fifth exit angle ⁇ 5.
  • Fig. 17 is a cross-sectional view taken along F-F of the sixth point 406, and the sixth point 406 forms a sixth tilting distance L6 and a sixth exit angle ⁇ 6.
  • the difference between the first exit angle ⁇ 1 and the second exit angle ⁇ 2 formed by the two points located on the first raised portion 410 is about 3°
  • the difference between the two points located on the second raised portion 420 is about 3°
  • the difference between the third exit angle ⁇ 3 and the fourth exit angle ⁇ 4 formed by the two points on the transition portion 430 is about 6°
  • the difference between the fifth exit angle ⁇ 5 and the sixth exit angle ⁇ 6 formed by the two points on the transition portion 430 is approximately 2°.
  • the rate of change of the exit angle ⁇ formed by the third point 403 and the fourth point 404 is greater than that of the first point 401 and the rate of change of the exit angle ⁇ formed by the second point 402, meanwhile, the change rate of the exit angle ⁇ formed by the third point 403 and the fourth point 404 is greater than that of the exit angle ⁇ formed by the fifth point 405 and the sixth point 406 rate of change.
  • the outlet angle located at the outermost side of the first raised portion 410 of the blade 30 is between 33° and 38°.
  • the exit angle of the first raised portion 410 is between 30° and 40°; the exit angle of the second raised portion 420 is between 20° and 35°.
  • the six points selected above are just arbitrarily selected for explaining the characteristics of the raised portion 400 of the blade 30 .
  • the following rules are met: in the radial direction along the blade 30, the exit angle ⁇ of the second raised portion 420 The rate of change of is greater than the rate of change of the outlet angle ⁇ of the first tilting portion 410 .
  • the tilting distance L follows a similar rule, that is, in the radial direction along the blade 30, the rate of change of the tilting length L of the second tilting portion 420 is greater than that of the first tilting portion 420.
  • the rate of change of the lift length L of the portion 410 is, in the radial direction along the blade 30, the rate of change of the tilting length L of the second tilting portion 420 is greater than that of the first tilting portion 420.
  • the second The rate of change of the exit angle ⁇ and the rate of change of the lift length L formed by the tilting portion 420 are both greater than the rate of change of the exit angle ⁇ and the rate of change of the lift length L formed by the first lift portion 410 and the transition portion 430 .
  • the outlet angle ⁇ formed by it is only for the airflow outlet orientation shown in FIG. 18 .
  • the upper surface of the tilting portion 400 of the blade 30 forms different angles based on the base portion 200 , such as ⁇ and ⁇ in FIG. 18 .
  • the different angles formed by the upper surface of the raised portion 400 of the blade 30 are continuously changed. That is to say, along the radial direction perpendicular to the blade 30 , the path formed when starting from the root of the raised portion 400 and transitioning to the first edge line 441 is a curved curve.
  • FIG. 11 also shows the shape of the first boundary line 441 of the raised portion 400 when viewed from directly above the blade 30.
  • the shape of the first boundary line 441 of the raised portion 400 projected on the first plane 240 is A curve 443 .
  • the absolute value of the slope of the first curve 443 at the second raised portion 420 is greater than the absolute value of the slope of the first raised portion 410 . If the raised portion 400 also includes a transition portion 430 , then on the upper surface of the blade 30 , the absolute value of the slope of the first curve 443 is greater at the second raised portion 420 than at the first raised portion 410 or the transitional portion 430 .
  • FIG. 19 shows the general direction of the lift force provided by the first tilting portion 410 and the second tilting portion 420 when the blade 30 rotates.
  • FIG. 20 is only a schematic diagram of force acting on the blade 30 , and does not indicate the exact magnitude and direction.
  • the lift force F2 formed by the second tilting portion 420 is greater than the lift force F3 formed by the third tilting portion 430 .
  • the advantage of this design is: on the one hand, the lifting force formed by the tilting part 400 from the first tilting part 410 to the second tilting part 420 and the third tilting part 430 gradually weakens, preventing the entire tilting
  • the excessive lifting force of the cutting part 400 causes the cuttings of grass to be deflected too much toward the base of the blade 30 when it is lifted, so that part of the cuttings of grass cannot touch the cutting part 300 here after falling;
  • the cutting part 310 goes deeper into the grass to be cut.
  • the cutting ability of the cutting part 300 is mainly concentrated on the first cutting part 310.
  • the airflows generated by each cutting portion of the blade 30 will affect each other when the blade 30 rotates.
  • a series of variables such as the length L are regulated, and ultimately the entire blade 30 exhibits a more suitable cutting effect.
  • the more broken grass clippings that are cut through multiple cuts are more likely to cover the entire grass bag, reducing the frequency of replacement of the grass bag by the user.
  • better aerodynamic performance can be achieved without running the blade 30 at a higher rotational speed.
  • the user charges, replaces the battery, or refuels the engine; on the other hand, the noise caused by the rotation of the blade 30 is also reduced, which further enhances the user experience.
  • the raised portion 400 has a slit 443 at both ends or one end of the blade 30b, so that the surface of the rightmost edge of the first raised portion 410b is in the same shape as the second straight line 212. certain angle.
  • This embodiment advantageously reduces the amount of grass clippings that become lodged in the mower chassis 20 .
  • the edge of the cutting portion 300c of the blade 30c forms a certain angle with the radial direction of the blade 30c. It can be considered that the cutting portion 300c of the blade 30c has a certain “twist”, but this does not mean that The characteristics of the raised portion 400c in the present application will not be changed.
  • the blade 30 involved in the present application can also be applied to the situation where two blades or even multiple blades are superimposed.
  • the second boundary line 442 of the transition part 430 may also be deflected to a certain extent, or the boundary of the transition part 430 is designed as a notch 411, etc., instead of the smooth transition shown in the embodiment, but the first warp
  • the raised portion 410 and the second raised portion 420 are less affected, and still satisfy the aforementioned characteristics.
  • lawn mower 10 includes blade 30 and also includes a second blade (not shown).
  • the second blade is an additional blade different from the blade 30 , and the second blade may have the same structural features as the blade 30 , or may have different structural features from the blade 30 .
  • the second blade can be arranged separately from the blade 30 to generate two cutting areas respectively, or can be arranged one above the other with the blade 30 , which is not limited here.

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Abstract

一种刀片及应用该种刀片的割草机，该刀片（30）包括：沿刀片（30）径向延伸的基部（200），该刀片（30）绕基部（200）上的第一轴线（101）旋转；切割部（300），由基部（200）向外延伸形成；翘起部（400），包含相连的第一翘起部（410）和第二翘起部（420），第一翘起部（410）比第二翘起部（420）距第一轴线（101）更远；翘起部（400）的上表面的第一边缘线（441）上的任意一点处的切线与垂直于第一轴线（101）的第一平面之间形成的夹角为出口角，在沿刀片（30）的径向方向上，第二翘起部（420）上的出口角的变化率大于第一翘起部（410）上的出口角的变化率。

Description

刀片及割草机
本申请要求在2021年12月27日提交中国专利局、申请号为202111611845.0的中国专利申请的优先权，该申请的全部内容通过引用结合在本申请中。
技术领域
本申请涉及割草设备技术领域，例如涉及一种刀片及割草机。
背景技术
割草机是一种用于修整草坪、植被等的机械工具，其又被称为除草机、剪草机或者草坪修剪机等。相关技术中的割草机多采用旋转的刀片对草进行旋转切割，有些使用者将割草机搭配集草袋一起使用，使得切下的草屑可被吸附至割草机的集草袋中进行集中收纳，以便实现后期的集中处理；也有些使用者任切下的草屑自由散落，作为一种有机肥料为草坪提供养料。
发明内容
本申请提供一种可适用于割草机的刀片及割草机，在不提高刀片转速的情况下，优化刀片的气动性能，从而提高刀片的碎草性能。
本申请采用如下的技术方案：一种适用于割草机的刀片，包括：基部，沿刀片的径向延伸，刀片设置为在被割草机驱动时能绕基部上的第一轴线旋转；切割部，由基部向外延伸形成；翘起部，包含相连的第一翘起部和第二翘起部，第一翘起部比第二翘起部距第一轴线更远；其中：翘起部的上表面的第一边缘线上的任意一点处的切线与垂直于第一轴线的第一平面之间形成的夹角为出口角，且在沿刀片的径向方向上，第二翘起部上的出口角的变化率大于第一翘起部上的出口角的变化率。
在一种实施例中，出口角在沿刀片的径向方向上连续变化。
在一种实施例中，在沿刀片的径向方向上，第二翘起部的长度大于第一翘起部的长度。
在一种实施例中，在沿刀片的径向方向上，第二翘起部的翘起长度的变化率大于第一翘起部的翘起长度的变化率。
在一种实施例中，翘起部的第一边界线投射在第一平面上形成第一曲线，第一曲线上在第二翘起部的任意一点处的斜率的绝对值处大于在第一翘起部的任意一点处的斜率的绝对值。
在一种实施例中，在沿垂直于刀片的径向方向上，从翘起部的根部出发过渡到第一边缘线时形成的路径为有弧度的曲线。
在一种实施例中，翘起部还包含与第二翘起部相连、且比第二翘起部更靠近基部的过渡部，第二翘起部的出口角沿刀片的径向方向的变化率大于过渡部的出口角沿刀片的径向方向的变化率。
在一种实施例中，第一翘起部的出口角介于30°和40°之间；第二翘起部的出口角介于20°和35°之间；
另外，本申请还提供一种割草机，该割草机包含如上所述的刀片。
在一种实施例中，除刀片外，割草机还包括额外的第二刀片。
附图说明
图1是割草机的示意图；
图2是割草机在一个可看到刀片的视角下的示意图；
图3是适用于上述割草机的刀片的立体示意图；
图4是上述刀片在另一视角下的示意图；
图5是图3所示的刀片的主视图；
图6是图3所示的刀片的俯视图；
图7是图3中所示的刀片的一部分的示意图；
图8是图3中所示的刀片的右视图；
图9是图8中右视图中的翘起部的局部放大图；
图10是图5所示的主视图的局部放大图；
图11是图6所示的俯视图的局部放大图；
图12至图17是在图10中六个剖切位置的侧面剖视图；
图18是图8中右视图中的翘起部的局部放大图；
图19是图7所示刀片的受力分析示意图；
图20是图7所示刀片的一种实施方式的示意图；
图21是图7所示刀片的另一种实施方式的示意图。
具体实施方式
下面将结合附图对本申请实施例的技术方案作进一步的详细描述，所描述的实施例仅是本申请一部分实施例，而不是全部的实施例。
在本申请的描述中，需要说明的是，术语“中心”、“上”、“下”、“左”、“右”、“前”、“后”等指示的方位或位置关系为基于附图所示的方位或位置关系，仅是为了便于描述本申请和简化描述，而不是指示或暗示所指的装置或元件必须具有特定的方位、以特定的方位构造和操作，因此不能理解为对本申请的限制。此外，术语“第一”、“第二”等仅用于描述目的，或者用于区分不同结构或部件，而不能理解为指示或暗示相对重要性。
本申请涉及的刀片通常应用于割草机，下面以一种可手推的割草机10为例说明。可以理解的是，割草机也可以是骑乘式割草机。
割草机的刀片通常被设计为包含切割部和与切割部形成一定角度的翘起部，切割部负责将需要切割的草切断，翘起部负责在旋转的刀片表面形成一定的升力，使得由切割部切下的草屑受到升力作用时向上运动，从而当草屑掉落时能够被刀片二次切割。这样做的好处是，与只被切割一次的草屑相比，经过二次切割的草屑通常被切的更碎。我们知道，当体积较大的草屑进入集草袋中时，集草袋容易较快地被集满，但当草屑被切割地更碎时，细碎的草屑能更充分的进入集草袋的空间中，从而延长了集草袋的使用时间，降低了割草机的集草袋需要被倾倒或更换频率，更碎的草屑作为肥料也更易分解或处理。所以无论操作者是否使用集草袋，设计者们都在追求让割草机的刀片切出更短、更碎的草屑。
为了实现以上目标，有些刀片被设置为以较大的转速旋转，这样一方面提升了刀片旋转时形成的升力，使得第一次切下的草屑被抬升至更高的高度；另一方面加快了刀片切向草屑的频率，进一步保证由高处掉下的草屑可再次被旋转的刀片切到。然而，让刀片在较高的转速下运转会使得刀片的耗能过大，割草机需要进行更加频繁的能源补给，或者影响同样电量或油量可以切割的草的数量。同时，更高的刀片旋转速度使得刀片转动产生更大的噪音，反而影响用户的使用体验。
所以，申请人试图在保持刀片具有合理转速的情况下，设法提高刀片表面形成的升力，让被切割过一次的草屑在下落到地面之前在空中停留更长的时间，提高被再次切到的几率，于是产生以下技术方案。
如图1和图2所示，割草机10包括把手60、底盘20、车轮40和刀片30，割草机10还可以包括动力源和传动机构等，动力源与传动机构配合，驱动车轮40转动，并驱动刀片30旋转。如图2所示，刀片30位于底盘20形成的容纳空间内，以图示第一旋转方向R绕旋转中心110转动。图中涉及的割草机还包括一个安装在割草机10上的集草袋50，被刀片30切割下来的草等通过底盘20上的排草通道21，进入集草袋50中。集草袋50并非割草机10的必需品，有些用户允许切割下来的草直接洒落在草面上，将割下的草作为肥料再次利用，这 样的操作习惯并不影响本申请中刀片实现的技术效果。
如图3所示，刀片30包含基部200、切割部300和翘起部400。基部200沿刀片30的径向向两侧延伸，一直延伸至切割部300。基部200的上表面包含一个前边界201和后边界202，在本实施例中，前边界201与后边界202均与刀片的径向方向基本平行。切割部300为刀片30进行切割作业时实现切割功能的主要作业部位，大部分的被切割物由图3所示的切割部300进行切割。刀片30还包含至少一个翘起部400，翘起部400位于刀片30的端部，翘起部400的翘起方向朝向远离切割部300的方向。图4从另一视角下可以更清晰的看到翘起部400的形状。
图5和图6分别为刀片30在图3中指定的方向坐标中的正前侧和正上方观察刀片30时得到的示意图，即图5为刀片30的主视图，图6为刀片30的俯视图。刀片30绕贯穿旋转中心110的第一轴线101旋转，刀片30的切割部300被分为第一切割部310和第二切割部320，第一切割部310相比第二切割部320更靠近被切割物的切割表面，所以当刀片30旋转时，第一切割部310相比第二切割部320可以切到更加低矮的草。在本实施例中，第一切割部310与基部200基本平行，第二切割部320呈一定弧度，并由基部200平滑过渡到第一切割部310。
在一些实施方式中，基部200的前边界201和后边界202不一定为单条直线，也可能为弧形等曲线条或者齿形等多条直线的组合，基部200的形状并不是本申请的核心，此处以相关技术中的常见的基部200的形式来继续讨论，即刀片30的基部200的前边界201和后边界202与刀片30的径向基本平行。
如图3至图6所示，定义一条沿刀片30的径向方向延伸的第一直线211，该第一直线211经过刀片30的旋转中心110，且位于刀片的上表面上。定义一条与刀片30的径向方向基本垂直的第二直线212，该第二直线212经过刀片30的旋转中心110，且位于刀片的上表面上。在这里，第一直线211与第二直线212基本垂直。可以理解的是，刀片30具有一个长度方向和宽度方向，基部200基本关于第一直线211对称，且也基本关于第二直线212对称，第一直线211方向与刀片30的长度方向平行，第二直线212与刀片30的宽度方向平行。
下面以图7所示的刀片30的一部分为例进行说明。翘起部400包含相连的第一翘起部410和第二翘起部420，第一翘起部410比第二翘起部420距第一轴线101更远。第一翘起部410和第二翘起部420的边界线基本上沿第一切割部310与第二切割部320的边界线延伸而来，需要注意的是，附图中关于翘起部400的虚线均是人为添加的示意线，以更好的显示翘起部400的各个部分，并非刀片30中实际存在的线条。在实际产品中，翘起部400的各部分平滑过渡，并未产生可以区分各部分边界的清晰的轮廓。在沿刀片30的径向方向上，第二翘 起部420的长度大于第一翘起部410的长度。翘起部400还可包含过渡部430，用于由第二翘起部420向基部200方向进行过渡。
定义一个第一平面240，该第一平面垂直于第一轴线101，且穿过刀片30的旋转中心110的中心点。在本实施方式中，基部200的上表面位于第一平面240上，切割部300的第一切割部310与第一平面240基本平行。
当我们按照图7指定的方向坐标中的右侧观察刀片30时，得到如图8所示的刀片30的右视图，图9为图8中的翘起部400的局部放大图。翘起部400在刀片的上表面形成两条边界线，分别为图8所示的第一边界线441和第二边界线442。第一边界线441位于与刀片30的切割部300相对的另一侧，即图7指定的方向坐标中的后侧，而第二边界线442位于与切割部300大致垂直的刀片30最外部边缘。
如图9所示，在沿与刀片200的径向基本垂直(即沿第二直线212)方向上，翘起部400的上表面的第一边界线441上的某一点处形成的切线与第一平面240之间的夹角为出口角α。由于第一切割部310与第一平面240基本平行，故以图9中所示的翘起部400的上表面的第一边界线441上的某一点处形成的切线与第一切割部310所在的平面之间的角度来等同于此处定义的出口角α，并且从第一边界线441上的不同点出发形成一系列不同的出口角α。需要强调的是，出口角α需位于翘起部400朝向切割部300弯折的表面，在本实施例中，即刀片30的上表面。
图9还示出了翘起部400的翘起距离L，翘起距离L为从翘起部400的根部出发，一直到第一边界线441之间的距离。翘起根部是指从切割部300向翘起部400过渡时经过的“分界线”。需要注意的是，翘起距离L是指在翘起部400向切割部300偏折靠近的表面上，即刀片30的上表面。
现在将注意力放到图10和图11上，为了更好的说明本申请的技术特点，图10和图11分别将图5和图6所示的刀片30的主视图和俯视图的一端进行放大，并在翘起部400的第一边界线441上随机寻找一系列点，分别为：第一翘起部410上的第一点401和第二点402，第二翘起部420上的第三点403和第四点404，以及过渡部430上的第五点405和第六点406。这一系列点的特点为翘起部400上每一部分上的两点之间在沿刀片30的径向方向上的距离相等，即沿第一直线211方向上的距离相等。也就是说，沿第一直线211方向上，第一点401与第二点402之间的距离等于第三点403与第四点404之间的距离，也等于第五点405与第六点406之间的距离。现在沿垂直于刀片30的径向方向，即第二直线212方向上“剖切”以上随机选出的六个点，分别形成如图12至图17所示的沿A-A、B-B、C-C、D-D、E-E和F-F 六个不同剖切面的六张剖视图。
图12为第一点401沿A-A剖切得到的剖视图，第一点401形成第一翘起距离L1和第一出口角α1。图13为第二点402沿B-B剖切得到的剖视图，第二点402形成第二翘起距离L2和第二出口角α2。图14为第三点403沿C-C剖切得到的剖视图，第三点403形成第三翘起距离L3和第三出口角α3。图15为第四点404沿D-D剖切得到的剖视图，第四点404形成第四翘起距离L4和第四出口角α4。图16为第五点405沿E-E剖切得到的剖视图，第五点405形成第五翘起距离L5和第五出口角α5。图17为第六点406沿F-F剖切得到的剖视图，第六点406形成第六翘起距离L6和第六出口角α6。
对于随机挑选的这六个点，位于第一翘起部410上的两个点形成的第一出口角α1和第二出口角α2的差值约为3°，位于第二翘起部420上的两个点形成的第三出口角α3和第四出口角α4之差约为6°，位于过渡部430上的两个点形成的第五出口角α5和第六出口角α6之差约为2°。由于每一部分上的两个点在沿刀片30的径向方向的距离相等，所以针对这六个点而言，第三点403和第四点404形成的出口角α的变化率大于第一点401和第二点402形成的出口角α的变化率，同时，第三点403和第四点404形成的出口角α的变化率大于第五点405和第六点406形成的出口角α的变化率。
具体地，在本实施例中，位于刀片30的第一翘起部410的最外侧的出口角介于33°和38°之间。一般来讲，第一翘起部410的出口角介于30°和40°之间；第二翘起部420的出口角介于20°和35°之间。
然而，以上选出的六个点只是为了解释刀片30的翘起部400的特点而随意选取的。对于本申请涉及的刀片来说，对于位于第一边界线441上的任意选取的点，都符合以下规律，即：在沿刀片30的径向方向上，第二翘起部420的出口角α的变化率大于第一翘起部410的出口角α的变化率。与上述出口角α类似的是，翘起距离L也为类似的规律，即：在沿刀片30的径向方向上，第二翘起部420的翘起长度L的变化率大于第一翘起部410的翘起长度L的变化率。
在实际观测刀片30时，第一切割部310与第二切割部320的边界线并不明晰，第一翘起部410与第二翘起部420的边界线同样也不明晰，但整体的变化规律复合上述描述。所以在实际测量出口角α的变化率时，我们采用在第一翘起部410和第二翘起部420上任意选取一段沿刀片30的径向距离相同的片段，通过测量其出口角α的差值的大小来对比出口角α的变化率的大小。在选取片段时需留意，尽量避开那些十分接近第一翘起部410和第二翘起部420、第二翘起部420和过渡部430之间的虚拟边界线(即图中翘起部400上的虚线)的点，而是 选择类似于图11中那些能被清晰看出所在的区域的点。
需要指出的是，出口角α的变化率及翘起长度L的变化率在第一翘起部410和过渡部430之间并无固定的大小关系，对于整个翘起部400而言，第二翘起部420形成的出口角α的变化率及翘起长度L的变化率均大于第一翘起部410和过渡部430形成的出口角α的变化率及翘起长度L的变化率。
如图18所示，在本实施例中，对于刀片30上的第一边界线441上的每一个点而言，其形成的出口角α仅是针对于图18中所示的气流出口方位，而在翘起长度L的根部出发一直过渡到出口角α时，基于基部200，刀片30的翘起部400的上表面形成不同的角度，例如图18中的β和γ。在一些实施方式中，刀片30的翘起部400的上表面形成不同的角度是连续变化的。也就是说，在沿垂直于刀片30的径向方向上，从翘起部400的根部出发过渡到第一边缘线441时形成的路径为有弧度的曲线。
图11还显示了从刀片30的正上方向下观察时，翘起部400的第一边界线441的形状，翘起部400的第一边界线441投射在第一平面240上的形状为第一曲线443。第一曲线443在第二翘起部420的斜率的绝对值处大于在第一翘起部410的斜率的绝对值。若翘起部400还包含过渡部430，那么在刀片30的上表面上，第一曲线443斜率的绝对值在第二翘起部420处大于在第一翘起部410或过渡部430处。
基于以上描述的刀片30的翘起部400的特殊构造，实现了一系列技术效果。图19示出了当刀片30旋转时，第一翘起部410和第二翘起部420提供的升力的大致方向。需要注意的是，图20仅为刀片30受力的示意图，不表示确切大小和方向。当刀片30旋转时，若只考虑翘起部400的每一部分单独做功，不考虑其中某一部分对另两部分造成的影响，第一翘起部410形成的升力F1大于第二翘起部420形成的升力F2，第二翘起部420形成的升力F2又大于第三翘起部430形成的升力F3。这样设计的有益之处是：一方面，翘起部400从第一翘起部410开始，向第二翘起部420和第三翘起部430处形成的升力逐渐减弱，防止了整个翘起部400的升力过大造成草屑被升起时向刀片30的基部方向偏转太多，而导致部分草屑无法在下落后在此接触到切割部300；另一方面，由于切割部300的第一切割部310更加深入被切割草，在首次切割时，切割部300的切割能力主要集中在第一切割部310，若刀片30靠外侧的端部的升力过小，易造成大量的草屑无法被抬起，或者草屑向底盘20边缘飞去，造成卡草或堵草等现象。
然而，由于第一翘起部410、第二翘起部420和过渡部430彼此相连，刀片30在旋转时各切割部产生的气流会相互影响，使用通过前文提到的出口角α及翘起长度L等一系列变量 进行调控，最终使得整个刀片30表现出较为合适的切割功效。通过被多次切割而被切的更碎的草屑更容易铺满整个集草袋，降低了用户更换集草袋的频率。并且，在运行本申请涉及的刀片30时，无需将刀片30运行在较高的转速下，即可实现较好的气动性能，这样一方面减少了刀片30在相同工作时间消耗的能量，减少了用户充电、更换电池、或者给引擎加油的频率；另一方面由刀片30旋转带来的噪音也被减弱，也进一步增强了用户体验。
如图20所示，在一种实施方式中，翘起部400在刀片30b的两端或一端处开一个切口443，使得第一翘起部410b的最右边缘的表面与第二直线212呈一定角度。此种实施方式有利于减少被卡在割草机底盘20里的草屑的数量。
如图21所示，在一种实施方式中，刀片30c的切割部300c的边缘与刀片30c的径向呈一定角度，可以认为刀片30c的切割部300c发生了一定的“扭转”，但这并不会造成本申请中翘起部400c的特性的改变。
此外，本申请涉及的刀片30还可被应用于两个刀片甚至多个刀片叠加使用的情况。对于有些刀片30，其过渡部430的第二边界线442也有可能发生一定的偏转，或者过渡部430的边界处设计为缺口411等，而非实施例中所示的平滑过渡，但第一翘起部410和第二翘起部420受到的影响较小，依然满足前文中所述的特性。
经过实验验证，本申请涉及的刀片与其它具有相似长度的刀片相比，本申请涉及的刀片具有更高的切割效率，在相同转速下消耗的能量更少，具有明显的优势。
在一种实施例中，割草机10包括刀片30，还包括第二刀片(图中未示出)。第二刀片是区别于刀片30的额外的刀片，第二刀片可以与刀片30具有相同的结构特征，也可与刀片30具有不同于的结构特征。第二刀片可以与刀片30分开排布，分别产生两个切割区域，也可与刀片30上下叠放排布，在此不做限制。

Claims (10)

  1. 一种适用于割草机的刀片，包括：
    基部，沿所述刀片的径向延伸，所述刀片设置为在被所述割草机驱动时能绕所述基部上的第一轴线旋转；
    切割部，由所述基部向外延伸形成；
    翘起部，包含相连的第一翘起部和第二翘起部，所述第一翘起部比所述第二翘起部距所述第一轴线更远；
    其中：
    所述翘起部的上表面的第一边缘线上的任意一点处的切线与垂直于所述第一轴线的第一平面之间形成的夹角为出口角，在沿所述刀片的径向方向上，所述第二翘起部上的所述出口角的变化率大于所述第一翘起部上的所述出口角的变化率。
  2. 根据权利要求1所述的刀片，其中：
    所述出口角在沿所述刀片的径向方向上连续变化。
  3. 根据权利要求1所述的刀片，其中：
    在沿所述刀片的径向方向上，所述第二翘起部的长度大于所述第一翘起部的长度。
  4. 根据权利要求1所述的刀片，其中：
    在沿所述刀片的径向方向上，所述第二翘起部的翘起长度的变化率大于所述第一翘起部的所述翘起长度的变化率。
  5. 根据权利要求1所述的刀片，其中：
    所述翘起部的所述第一边界线投射在所述第一平面上形成第一曲线，所述第一曲线上在所述第二翘起部的任意一点处的斜率的绝对值处大于在所述第一翘起部的任意一点处的斜率的绝对值。
  6. 根据权利要求1所述的刀片，其中：
    在沿垂直于所述刀片的径向方向上，从所述翘起部的根部出发过渡到所述第一边缘线时形成的路径为有弧度的曲线。
  7. 根据权利要求1所述的刀片，其中：
    所述翘起部还包含与所述第二翘起部相连、且比所述第二翘起部更靠近所述基部的过渡部，所述第二翘起部的所述出口角沿所述刀片的径向方向的变化率大于所述过渡部的所述出口角沿所述刀片的径向方向的变化率。
  8. 根据权利要求1所述的刀片，其中：
    所述第一翘起部的所述出口角介于30°和40°之间；
    所述第二翘起部的所述出口角介于20°和35°之间。
  9. 一种割草机，包括权利要求1至权利要求8中任一项所述的刀片。
  10. 根据权利要求9所述的割草机，其中：除所述刀片外，所述割草机还包括第二刀片。
PCT/CN2022/124824 2021-12-27 2022-10-12 刀片及割草机 WO2023124380A1 (zh)

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Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1381164A (zh) * 2001-04-19 2002-11-27 本田技研工业株式会社 用于割草机上的刀片
US6487840B1 (en) * 2000-07-20 2002-12-03 Fisher Barton, Inc. Combined mulching and shredding blade
CN1406461A (zh) * 2001-09-06 2003-04-02 美瑞股份有限公司 旋转式割草机刀片
CN102972144A (zh) * 2012-12-19 2013-03-20 长铃集团有限公司 一种环保型割草机刀片
CN105075497A (zh) * 2014-04-21 2015-11-25 苏州宝时得电动工具有限公司 割草机切割刀片
CN209151589U (zh) * 2018-11-26 2019-07-26 黑龙江省农业科学院草业研究所 用于割草机的刀片、割草机
CN110113932A (zh) * 2016-12-27 2019-08-09 本田技研工业株式会社 切割刀片及割草机
CN110121257A (zh) * 2016-12-27 2019-08-13 本田技研工业株式会社 切割刀片及割草机
CN211353108U (zh) * 2019-10-15 2020-08-28 格力博(江苏)股份有限公司 刀片及割草机
CN113115623A (zh) * 2020-01-10 2021-07-16 南京德朔实业有限公司 一种用于割草机的切割刀片及割草机
CN214902208U (zh) * 2021-06-15 2021-11-30 山东禀正智慧科技有限公司 一种割草机刀盘及割草机

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6487840B1 (en) * 2000-07-20 2002-12-03 Fisher Barton, Inc. Combined mulching and shredding blade
CN1381164A (zh) * 2001-04-19 2002-11-27 本田技研工业株式会社 用于割草机上的刀片
CN1406461A (zh) * 2001-09-06 2003-04-02 美瑞股份有限公司 旋转式割草机刀片
CN102972144A (zh) * 2012-12-19 2013-03-20 长铃集团有限公司 一种环保型割草机刀片
CN105075497A (zh) * 2014-04-21 2015-11-25 苏州宝时得电动工具有限公司 割草机切割刀片
CN110113932A (zh) * 2016-12-27 2019-08-09 本田技研工业株式会社 切割刀片及割草机
CN110121257A (zh) * 2016-12-27 2019-08-13 本田技研工业株式会社 切割刀片及割草机
CN209151589U (zh) * 2018-11-26 2019-07-26 黑龙江省农业科学院草业研究所 用于割草机的刀片、割草机
CN211353108U (zh) * 2019-10-15 2020-08-28 格力博(江苏)股份有限公司 刀片及割草机
CN113115623A (zh) * 2020-01-10 2021-07-16 南京德朔实业有限公司 一种用于割草机的切割刀片及割草机
CN214902208U (zh) * 2021-06-15 2021-11-30 山东禀正智慧科技有限公司 一种割草机刀盘及割草机

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