JPH04183317A - Portable bush cutter furnished with over-load protection device - Google Patents
Portable bush cutter furnished with over-load protection deviceInfo
- Publication number
- JPH04183317A JPH04183317A JP31142390A JP31142390A JPH04183317A JP H04183317 A JPH04183317 A JP H04183317A JP 31142390 A JP31142390 A JP 31142390A JP 31142390 A JP31142390 A JP 31142390A JP H04183317 A JPH04183317 A JP H04183317A
- Authority
- JP
- Japan
- Prior art keywords
- rotary blade
- blade
- bevel gear
- power
- shaft
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 230000005540 biological transmission Effects 0.000 claims abstract description 24
- 238000003825 pressing Methods 0.000 abstract description 2
- 230000002265 prevention Effects 0.000 description 7
- 230000006378 damage Effects 0.000 description 6
- 238000005520 cutting process Methods 0.000 description 5
- 230000035939 shock Effects 0.000 description 5
- 239000002184 metal Substances 0.000 description 4
- 229910000831 Steel Inorganic materials 0.000 description 3
- 239000010959 steel Substances 0.000 description 3
- 208000027418 Wounds and injury Diseases 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 208000014674 injury Diseases 0.000 description 2
- 239000002689 soil Substances 0.000 description 2
- 241000196324 Embryophyta Species 0.000 description 1
- JOYRKODLDBILNP-UHFFFAOYSA-N Ethyl urethane Chemical compound CCOC(N)=O JOYRKODLDBILNP-UHFFFAOYSA-N 0.000 description 1
- 229910000677 High-carbon steel Inorganic materials 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000009499 grossing Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000009987 spinning Methods 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Landscapes
- Harvester Elements (AREA)
Abstract
Description
【発明の詳細な説明】 〔産業上の利用分野〕 この発明は、可搬式刈払機に関するものである。[Detailed description of the invention] [Industrial application field] The present invention relates to a portable brush cutter.
雑草や雑木などを刈払い処理する可搬式刈払機は。 A portable brush cutter is used to cut down weeds and shrubs.
整然とした場所ばかりでなく、むしろ荒地や料地なとて
使用される場合か多く、運転中、回転刃が木の根や土中
などに食い込んだりして、高速回転している回転刃か、
強制的にその回転を停止させられてしまうケースが頻繁
に発生している。It is often used not only in tidy areas, but also on waste land or farmland, and during operation, the rotary blade may dig into tree roots or soil, causing the rotary blade to rotate at high speed.
There are many cases where the rotation is forced to stop.
この急激にかかる過＠伺は、なんのクツションもなく刈
払機そのものに強大なねじり衝撃力を与え、動力を伝達
する各部品が、これによって破損したり寿命を縮めるこ
とが良くあった。これら急激にかかる過負荷から各動力
伝達機構部品を保護するため、現実的な対策としては、
各機構部品の材質や強度を上げ、これらの急激な衝撃が
、１千回以上作用しても破損しないような耐久性を付与
して設計せざるを得ず、このことが刈払機の軽量化を阻
んでいるばかりでなく、コストアップの最大の要因にも
なり過剰品質を招いて来たのである。This rapid overload applies a huge torsional impact force to the brush cutter itself without any cushioning, which often damages the parts that transmit power or shortens the life of the brush cutter. In order to protect each power transmission mechanism component from these sudden overloads, practical measures include:
We had to increase the material and strength of each mechanical part and design it so that it would not be damaged even if these sudden impacts were applied over 1,000 times, and this made the brush cutter lighter. This has not only hindered production, but has also become the biggest factor in increasing costs, leading to excessive quality.
この問題を解決しようとする方法として、例えば昭５９
−１０２．３２１号公報（先行例）のように背負式の刈
払機において一定以上のトルクが作用した際に第１伝動
軸１４とクラッチドラム１３との間にすべりが生じるよ
うにし、このすべりによって衝撃を吸収するするように
したものが示されている。As a way to try to solve this problem, for example,
- As in Publication No. 102.321 (preceding example), when a torque above a certain level is applied to a backpack-type brush cutter, slipping occurs between the first transmission shaft 14 and the clutch drum 13, and this slipping causes A device designed to absorb shock is shown.
上記のごとく、急激にかかる衝撃を吸収しようとする先
行例において、しかしながら回転刃に受けた衝撃は、次
の動力伝達機構の従動傘歯車軸から従動傘歯車及び駆動
傘歯車を介し伝動軸に伝わり、更に機構を直角に変える
ための従動傘歯車及び駆動傘歯車を介して第１伝動軸に
伝わり、ここでようやくこの衝撃を第１伝動軸とクラッ
チトラムとの間にすべりが生ずるようにして、エンジン
側のクラッチドラムに伝えないようにしたものである。As mentioned above, in the previous example of trying to absorb a sudden impact, the impact received by the rotating blade is transmitted from the driven bevel gear shaft of the next power transmission mechanism to the transmission shaft via the driven bevel gear and the driving bevel gear. , and is further transmitted to the first transmission shaft via a driven bevel gear and a driving bevel gear for changing the mechanism at right angles, and only then is this impact caused to cause slippage between the first transmission shaft and the clutch tram, This prevents the signal from being transmitted to the clutch drum on the engine side.
この方法では、第１に、機構上極めて複雑であり形状的
にも大きくなるばかりでなく、部品点数が増えそれに伴
って機構全体が重くなり、コストか大幅に上昇するとい
う欠点かあ、た。また第２に、急激にかかる衝撃を吸収
する目的は回転刃以降の従動傘歯車軸や、従動・駆動傘
歯車そして伝動軸なとの動力伝達機構部品を摩耗や破損
から保護するものでなければならす、その意味からも一
瞬にかかるこれらの衝撃はこれを直接受ける回転刃か、
その付近で吸収されるのが最も望ましい。First, this method has the disadvantage that it is not only mechanically complex and large in size, but also increases in the number of parts, which increases the weight of the entire mechanism, resulting in a significant increase in cost. Secondly, the purpose of absorbing sudden shocks must be to protect the power transmission mechanism parts such as the driven bevel gear shaft after the rotary blade, the driven and driving bevel gears, and the transmission shaft from wear and damage. From the meaning of "smoothing", these instantaneous shocks are probably due to the rotating blade receiving them directly.
It is most desirable that it be absorbed near that point.
しかしながら、先行例に於いては衝撃がほとんとこれら
の部品に作用した後エンジンに直結されたクラッチトラ
ムでこれを吸収するようになっており、動力伝達機構の
各部品を摩耗や破損から保護するという目的が十分果せ
なかった。従ってこの回転刃に急激にかかる強力な過負
荷を機構上極めて簡単で従来形状を変えることなく、安
価な方法でしかも衝撃を受ける回転刃に直接これを吸収
する機構を持たせることで、後の動力伝達機構各部品を
摩耗や破損から保護することができる過負荷防止機能を
持った刈払機の開発が切望されていた。However, in previous models, most of the impact is applied to these parts and then absorbed by the clutch tram, which is directly connected to the engine, protecting each part of the power transmission mechanism from wear and damage. The purpose was not fully achieved. Therefore, by providing a mechanism that directly absorbs the strong overload that is suddenly applied to the rotary blade in an extremely simple and inexpensive way without changing the conventional shape, the rotary blade that receives the impact can be directly absorbed. There has been a strong desire to develop a brush cutter with an overload prevention function that can protect each part of the power transmission mechanism from wear and damage.
又、従来急激に回転刃にかかる衝撃を吸収するように構
成されていないため・回転刃が木などに当ってハネ返る
キックバックなる現象が度々発生し、作業者や周囲の人
が大怪我をするような事故か増えておりこのような安全
面で致命的とも思えるキックバックを防止する有効な対
策が待たれていた。Additionally, because conventional blades are not designed to absorb sudden shocks, kickbacks, where the blades bounce back when they hit trees, often occur, resulting in serious injuries to workers and other people nearby. The number of such accidents is increasing, and effective measures to prevent kickbacks, which can be considered fatal from a safety perspective, have been awaited.
この発明は、このような刈払機に於いて早急に解決しな
ければならない極めて重要な問題を、簡単な機構を取り
付けることで一挙に解決できるものであって、その特徴
とするところは、エンジン等の動力がクラッチドラムか
ら直接伝動軸に伝わり、歯車室の駆動・従動の傘歯車を
介して回転刃に伝わる機構を持った刈払機に於いて、急
激に、一定以上のトルク荷重が回転刃にかかった場合、
回転刃か歯車室にクラッチ機構を設け、回転刃に相対的
なすべりか生じるようにし、このすへりによってこの衝
撃を吸収しようとするものである。This invention can solve the extremely important problems that must be solved immediately in brush cutters by installing a simple mechanism, and its characteristics are as follows: In a brush cutter that has a mechanism in which the power is transmitted directly from the clutch drum to the transmission shaft and then to the rotary blade via the driving/driven bevel gear in the gear chamber, a torque load exceeding a certain level is suddenly applied to the rotary blade. If it takes,
A clutch mechanism is provided in either the rotary blade or the gear chamber to create a relative slip between the rotary blades, and the impact is absorbed by this slippage.
このように、回転刃そのものが過負荷防止機構を持った
刈払機は、通常の刈払い運転中は、従来の性能を低下す
る事なく作業でき、−瞬、回転刃が木の根や土中などの
異物に食い込み、回転不能に陥ったりしたときは、この
回転刃が空転するために、その衝撃は回転刃以降の動力
伝達機構の各部品に伝わらないようになる。また、刈払
い作業時に於ける高速運転中、回転刃が硬い異物などに
当たった際に、尚もそのまま回転しようとするため、刈
払機が弾き飛ばされるキックバック現象も、この過負荷
防止装置によってその衝撃が吸収されることから、大幅
に起こりにくくなるのである。In this way, a brush cutter whose rotary blade itself has an overload prevention mechanism can work without deteriorating its performance during normal brush cutting operation, and in an instant, the rotary blade can cut through tree roots, underground, etc. If a foreign object bites into the rotary blade and it becomes unable to rotate, the rotary blade will idle, and the impact will not be transmitted to the parts of the power transmission mechanism after the rotary blade. This overload prevention device also prevents the kickback phenomenon in which when the rotary blade hits a hard foreign object during brush cutting work, it continues to rotate, causing the brush cutter to be blown away. Because the shock is absorbed, it becomes much less likely to occur.
〔実施例コ
次に、この発明の内容を、その最良の実施例を示す図面
に基すいて説明する。[Embodiments] Next, the contents of the present invention will be explained based on the drawings showing the best embodiments thereof.
第１図は、本発明が適用される過負荷防止装置付きの刈
払機に於ける動力伝達機構を示しており、エンジンの動
力が、遠心クラッチ１ａから長尺な伝動軸１ｂを経て、
歯車室内の駆動傘歯車１ｃと従動傘歯車１ｄを介して、
従動傘歯車軸１ｅに回転トルクを伝え、これによってこ
の従動傘歯車軸１ｅに取り付けられた、刈刃受は金具１
ｆと鋸刃押え金具１ｇとにより挟着、固定された回転刃
１ｈが回転するようになっている。FIG. 1 shows a power transmission mechanism in a brush cutter equipped with an overload prevention device to which the present invention is applied, in which engine power is transmitted from a centrifugal clutch 1a through a long transmission shaft 1b.
Via the driving bevel gear 1c and the driven bevel gear 1d in the gear chamber,
Rotational torque is transmitted to the driven bevel gear shaft 1e, and thereby the cutting blade holder attached to the driven bevel gear shaft 1e is connected to the metal fitting 1.
The rotary blade 1h, which is clamped and fixed by the saw blade holding member 1g, rotates.
ここでは、回転刃１ｈが上記、動力伝達機構に於ける従
動傘歯車軸１ｅに対して、ある一定の抵抗を有して回転
可能となるように構成されている。Here, the rotary blade 1h is configured to be rotatable with a certain resistance with respect to the driven bevel gear shaft 1e in the power transmission mechanism.
第２図は、本発明による過荷重防止機構を取り付けた刈
払機の第１図に於ける歯車室の詳細を示す拡大図である
。これを構成する各部品は、はとんど、従来部品をその
まま使って本機構を構成するため、従動傘歯車軸１ｅを
従来寸法より５ミリ程度長くする。この数ミリ長くされ
た、従動傘歯車軸１ｅに刈刃受は金具１ｆ、回転刃１ｈ
、受は座金１１それに皿バネ１ｊと鋸刃押え金具１ｇを
順次嵌挿し、これらを座付ナツト１にで締め付ける。FIG. 2 is an enlarged view showing details of the gear chamber in FIG. 1 of the brush cutter equipped with the overload prevention mechanism according to the present invention. Since this mechanism is constructed using conventional parts as they are, the driven bevel gear shaft 1e is made approximately 5 mm longer than the conventional dimensions. The driven bevel gear shaft 1e, which has been lengthened by several millimeters, has a cutting blade holder with a metal fitting 1f and a rotary blade 1h.
For the receiver, fit the washer 11, the disc spring 1j, and the saw blade holding fitting 1g in sequence, and tighten these onto the seat nut 1.
このようにして、回転刃１ｈは、刈刃受は金具１ｆと受
は座金１１との間に弾性的に挟着、固定され従動傘歯車
軸１ｅとは一定の抵抗を有して回転可能になるのである
。この皿バネの弾力を調整することで、回転刃１ｈにか
かる抵抗の大きさを変えることができ、エンジンの容量
や、使用目的あるいは安全対策等によって選択できるの
である。In this way, the rotary blade 1h is elastically clamped and fixed between the cutting blade receiver metal fitting 1f and the receiver washer 11, and is rotatable with a certain resistance against the driven bevel gear shaft 1e. It will become. By adjusting the elasticity of this disk spring, the magnitude of the resistance applied to the rotary blade 1h can be changed, and can be selected depending on the engine capacity, purpose of use, safety measures, etc.
また、第３図は、本発明の他の実施例を示す。Further, FIG. 3 shows another embodiment of the present invention.
刈払機の歯車室内に於いて、クラッチケース３ａを設け
るとともに、エンジンの動力を回転刃に伝える従動傘歯
車軸を、それぞれ端部にフランジ部を設けた駆動軸３ｂ
と、従動軸３Ｃとに分割し、この駆動軸のフランジ部と
従動軸のフランジ部の突き合わせ面には、鋼球３ｄが入
るような凹部を形成し、この凹部に鋼球を嵌挿し、これ
をクラッチケース３ａと駆動軸３ｂとの間に入れたスプ
リング３ｅの弾力で挟着、固定することによって、駆動
軸３ｂの回転トルクは、一定の抵抗を有して、従動軸３
ｃを回転可能にするのである。また、回転刃が木などに
食い込み、一定以上のトルクが作用した場合には、駆動
軸３ｂと従動軸３Ｃのフランジ面に嵌挿されたスプリン
グ３ｅの弾力による押圧力でこれら二つの部品に挟着さ
れた鋼球が、駆動軸３ｂを押し上げ、そこにすべりが生
じて空転し、この衝撃を吸収するのである。In the gear chamber of the brush cutter, a clutch case 3a is provided, and a driven bevel gear shaft that transmits engine power to the rotary blade is provided with a drive shaft 3b each having a flange portion at its end.
and a driven shaft 3C, a recess into which the steel ball 3d can be inserted is formed on the abutting surfaces of the flange of the drive shaft and the flange of the driven shaft, and the steel ball is inserted into this recess. By clamping and fixing the spring 3e between the clutch case 3a and the drive shaft 3b, the rotational torque of the drive shaft 3b is applied to the driven shaft 3 with a certain resistance.
This makes it possible to rotate c. In addition, if the rotary blade bites into a tree or the like and a torque above a certain level is applied, the pressing force due to the elasticity of the spring 3e fitted into the flange surfaces of the drive shaft 3b and the driven shaft 3C will cause the blade to be pinched between these two parts. The attached steel balls push up the drive shaft 3b, causing slippage and spinning, absorbing this impact.
この金属製のスプリングの代わりにウレタンなどの弾性
ゴムを使用しても良い。Elastic rubber such as urethane may be used instead of this metal spring.
また、他の実施例として、従動傘歯車軸を駆動軸４ａと
従動軸４ｂとに分割し、その内径を非円形状のパイプ形
状に形成し、その中に同形状で嵌合でき、切り欠き部４
ｃｌを設けた、高炭素鋼を熱処理して成るシェアピン４
Ｃを挿入し、−瞬かかる衝撃をこのシェアピンの破損で
止めるようにすることもできる。要するに、本発明は刈
払機に於いて、回転刃にかかる過負荷を回転刃か歯車室
にクラッチ機構を設け、これを吸収し、後の動力伝達機
構の各部品に伝えないようにすれば良いのであって、具
体的な構成は、上記のものに限定されるものではない。In addition, as another embodiment, the driven bevel gear shaft is divided into a driving shaft 4a and a driven shaft 4b, and the inner diameter of the shaft is formed into a non-circular pipe shape, which can be fitted in the same shape, and a notch is formed. Part 4
Shear pin 4 made of heat-treated high carbon steel with cl
C can be inserted so that the instantaneous impact is stopped by the breakage of this shear pin. In short, in the present invention, in a brush cutter, a clutch mechanism is provided in the rotary blade or the gear chamber to absorb the overload applied to the rotary blade and prevent it from being transmitted to the later parts of the power transmission mechanism. However, the specific configuration is not limited to the above.
この発明は以上説明した通りのものであって、本発明に
よる刈払機は、運転中、回転刃が木の根や土中に食い込
んだりした際の、強大なねじり衝撃力を、回転刃か、あ
るいはその周辺の歯車室において、これを吸収すること
が可能となり、これによって、回転刃以降の各動力伝達
機構部品を、強い衝撃による摩耗や破壊から、効果的に
保護することができるだけでなく、これらの部品の過剰
品質を改善することにより軽量化とコストダウンが図ら
れることになるのである。The present invention is as explained above, and the brush cutter according to the present invention is capable of absorbing a strong torsional impact force from the rotary blade or its blade when the rotary blade digs into tree roots or soil during operation. This can be absorbed in the surrounding gear chamber, and this not only effectively protects the power transmission mechanism parts after the rotary blade from wear and tear caused by strong impacts, but also By improving the excessive quality of parts, weight and cost reductions can be achieved.
また、作業中の危険なキックパックの発生を大幅に軽減
でき、作業者を怪我から守るなど安全面に於いても、計
り知れない利点を有するものである。Furthermore, the occurrence of dangerous kick packs during work can be greatly reduced, and it has immeasurable advantages in terms of safety, such as protecting workers from injury.
第１図は、この発明の第一実施例を示す過負荷防止装置
付きの刈払機について、その動力伝達機構を示した、斜
視図。
第２図は、第１図の拡大、斜視図。
第３図は、及び第４図は本発明の過負荷防止装置の他の
実施例を示す略図である・FIG. 1 is a perspective view showing a power transmission mechanism of a brush cutter equipped with an overload prevention device according to a first embodiment of the present invention. FIG. 2 is an enlarged perspective view of FIG. 1. 3 and 4 are schematic diagrams showing other embodiments of the overload prevention device of the present invention.
Claims (1)
歯車などの動力伝達機構を通じて回転刃を回転させる可
搬式刈払機において、運転中、回転刃に作用する過負荷
を防止する方法として、回転刃か歯車室周辺にクラッチ
機構を設け、ある一定以上の負荷がこの回転刃に作用す
る時はこれを吸収し、衝撃を回転刃以降の動力伝達機構
に伝えないようにしたことを特徴とする可搬式刈払機。In a portable brush cutter that uses a power source such as an engine to rotate the rotary blade through a power transmission mechanism such as a centrifugal clutch, transmission shaft, or bevel gear, the rotation A clutch mechanism is provided around the blade or the gear chamber, and when a load above a certain level is applied to the rotary blade, it is absorbed and the impact is not transmitted to the power transmission mechanism after the rotary blade. Portable brush cutter.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31142390A JPH04183317A (en) | 1990-11-19 | 1990-11-19 | Portable bush cutter furnished with over-load protection device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31142390A JPH04183317A (en) | 1990-11-19 | 1990-11-19 | Portable bush cutter furnished with over-load protection device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04183317A true JPH04183317A (en) | 1992-06-30 |
Family
ID=18017027
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP31142390A Pending JPH04183317A (en) | 1990-11-19 | 1990-11-19 | Portable bush cutter furnished with over-load protection device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04183317A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009296936A (en) * | 2008-06-13 | 2009-12-24 | Nikkari Co Ltd | Cutting blade shaft structure of mower |
| CN106827026A (en) * | 2017-04-11 | 2017-06-13 | 广州元凛建筑工程技术开发有限公司 | A kind of plate cutting device |
-
1990
- 1990-11-19 JP JP31142390A patent/JPH04183317A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009296936A (en) * | 2008-06-13 | 2009-12-24 | Nikkari Co Ltd | Cutting blade shaft structure of mower |
| CN106827026A (en) * | 2017-04-11 | 2017-06-13 | 广州元凛建筑工程技术开发有限公司 | A kind of plate cutting device |
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