JP2011036136A - Protective cover unit and brush cutter equipped with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a protective cover unit that prevents reduction in number of revolutions of cutting blade and stop of rotation by avoiding winding of cut materials, etc., on an output shaft, consequently, promotes safety and efficiency improvement of brush clearing operation and a brush cutter equipped with the same. <P>SOLUTION: The protective cover unit is attached to the brush cutter that is equipped with an operation rod into which a drive shaft is inserted, a gear case that is arranged at the tip of the operation rod and stores a bevel gear unit connected to the drive shaft and the disk-like cutting blade disposed under the gear case and fixed to the output shaft of the bevel gear unit. The protective cover unit is equipped with a bottomed cylindrical inner cover to be attached to the output shaft and an outer cover that is fixed through a connection tool to the tip side of the operation rod so as to cover the gear case and the inner cover. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a protective cover unit and a brush cutter provided with the same, and more particularly to a protective cover unit capable of effectively preventing a cut object or the like from being wound around an output shaft and a brush cutter provided with the same. .

  Generally, a brush cutter is provided with an operating rod for inserting a drive shaft, a gear case attached to a tip of the operating rod and housing a bevel gear unit connected to the drive shaft, and disposed below the gear case. It mainly includes a disk-shaped cutting blade fixed to the output shaft of the unit, and an engine unit that is disposed at the rear end of the operating rod and configured to transmit power to the drive shaft. Many of these brush cutters are provided with a scattering prevention cover for preventing pebbles and the like from scattering to the operator.

  The brush cutter having the above-described structure is excellent in portability, and is suitably used as a device that can easily and efficiently cut plants and the like. On the other hand, since such a brush cutter can be easily used by anyone, high safety is required.

  However, in such a brush cutter, vegetation and the like cut by the rotation of the cutting blade (hereinafter abbreviated as “cutting object etc.”) are wound around the output shaft and become the rotational resistance of the cutting blade, and the rotational speed of the cutting blade is reduced. May decrease or stop rotation. In this case, in order to restore the rotation of the cutting blade, the operator needs to remove the cut matter wound around the output shaft.

  Regarding the removal of such cut objects, the worker needs to work in a state where the operation of the cutting blade is turned off in order to ensure safety. However, in a state where the rotation of the cutting blade is stopped, there is a risk of forgetting to turn off the operation of the cutting blade. If the cutting object is removed in a state where the operation of the cutting blade is not turned off, the cutting blade suddenly resumes rotation during the removal work, and the operator damages or cuts the fingers and the like. There is a fear.

  Further, when removing a cut object or the like, it may be necessary to remove the cutting blade with a special tool. In such a case, the work efficiency is extremely reduced. And, in the work in a place where vegetation is overgrown or in a place where there are many bushes and vines, the rotation of the cutting blade frequently stops, so the work efficiency is remarkably deteriorated.

  In order to solve such problems, various types of brush cutter protective equipment have been proposed today. For example, (1) an apparatus that prevents a long string-like object such as a cut object from being wrapped around the output shaft by providing a cutting tool around the output shaft (see Japanese Patent Application Laid-Open No. 2008-1113650), (2) A protective cover (Japanese Patent Laid-Open No. 2008-113640) having a flat bottomed cylindrical shape and a side wall warped outward has been developed.

  However, the apparatus (1) cannot effectively prevent a reduction in the number of rotations of the cutting blade and a stop of rotation because a cut object or the like cut by the cutting tool may be wound around the output shaft. Further, in order to keep the sharpness of the cutting tool in good condition, it is necessary to replace the cutting tool periodically, etc., so that care and labor are required.

  In the protective cover (2), there is a possibility that a cut object or the like may enter the output shaft beyond the side wall of the protective cover, and therefore it is impossible to effectively prevent a reduction in the number of rotations of the cutting blade and a stop of the rotation.

  Thus, the bush cover protective cover is desired to have a structure that can effectively prevent the rotation speed of the cutting blade from being lowered or stopped when a cut object or the like is wound around the output shaft. Yes. However, there is currently no protective cover for a brush cutter having such a structure.

JP 2008-1113650 A JP 2008-1113640 A

  The present invention has been made in view of these inconveniences, and effectively prevents a cut object or the like from being wound around the output shaft, thereby reducing the rotation speed of the cutting blade or stopping the rotation, and thus the work safety. It is an object of the present invention to provide a protective cover unit that can significantly improve efficiency and efficiency, and a brush cutter provided with the same.

The invention made to solve the above problems is
An operating rod for inserting the drive shaft, a gear case attached to the tip of the operating rod and housing the bevel gear unit connected to the drive shaft, and disposed below the gear case and fixed to the output shaft of the bevel gear unit A protective cover unit to be attached to a brush cutter provided with a disk-shaped cutting blade,
A cylindrical inner cover with a bottom attached to the upper surface of the cutting blade in the output shaft of the bevel gear unit;
An outer cover in the form of a shoe upper disposed above the gear case so as to cover the gear case, the inner cover, and the tip of the operating rod;
A protective cover unit including a connecting tool for connecting the outer cover to the operating rod.

  The protective cover unit can prevent the cut object or the like from being wound around the output shaft by the inner cover and the outer cover. Therefore, the protective cover unit can remarkably reduce the possibility that the rotational speed of the cutting blade is reduced or the rotation is stopped when a cut object or the like is wound around the output shaft. As a result, the protective cover unit can dramatically improve the safety and efficiency of the brushing operation.

  A semi-cylindrical main body that covers the gear case, the inner cover, and the tip of the operating rod, a front wall that extends from the front edge of the main body and covers the front side of the gear case and the inner cover, and one side surface of the main body It is good to have a side wall that extends from the edge and covers the gear case, the inner cover, and the cutting blade rotation direction side of the tip of the operating rod. In the operation by the brush cutter, the cut object or the like moves to the rotation direction side of the cutting blade. Therefore, the protective cover unit can effectively block a cut object or the like by the front wall and the side wall of the outer cover. On the other hand, according to such a configuration, the outer cover can have a notch on the side opposite to the rotational direction side of the cutting blade. Thereby, the cut | disconnected thing etc. which passed between the outer cover and the cutting blade and entered into the output-axis direction can be discharged | emitted easily. As a result, the protective cover unit can easily create a state in which a cut object or the like does not exist around the output shaft during the brushing operation. Therefore, the protective cover unit can more effectively prevent a reduction in the number of rotations of the cutting blade and a stoppage of rotation due to a cut object or the like wound around the output shaft. Moreover, since the main body of the outer cover covers the upper part of the gear case and the inner cover, the protective cover unit can prevent vegetation and the like from entering the output shaft from above.

  As a means for engaging the outer cover and the connecting tool, a pair of engaging holes at the rear of the outer cover, a pair of engaging holes at both ends of the connecting tool, and bolts and nuts connected to and fixed to these engaging holes are provided. By configuring the pair of engaging holes of the outer cover in a substantially vertical slit shape and changing the bolt position in the pair of slit-shaped engaging holes, the height position of the outer cover can be variably configured. Good. Thereby, irrespective of the structure of the brush cutter, the distance between the outer cover and the cutting blade can be kept optimal. Therefore, the protective cover unit can effectively block cuts and the like entering the output shaft from below the outer cover.

  Therefore, an operating rod for inserting the drive shaft, a gear case attached to the tip of the operating rod and housing the bevel gear unit connected to the drive shaft, and disposed below the gear case and fixed to the output shaft of the bevel gear unit. A disc-shaped cutting blade, an engine portion arranged at the rear end of the operating rod and configured to transmit power to the drive shaft, and a bottomed surface attached to the upper surface of the cutting blade on the output shaft of the bevel gear unit A cylindrical inner cover, a shoe upper outer cover disposed above the gear case so as to cover the gear case, the inner cover, and the tip of the operating rod, and a connector for connecting the outer cover to the operating rod. The brush cutter provided with effectively prevents the rotation speed of the cutting blade from being reduced or the rotation from being stopped by cutting or the like being wound around the output shaft. Can, it can be promoted and thus the cutting 払作 industry safety and efficiency.

  In the present specification, “up” means the direction opposite to the ground side in the brushing work state, and “down” means the opposite direction. Further, “front” means the forward direction as viewed from the worker in the brushing work state, and “rear” means the opposite direction. “Right” means the right direction as viewed from the operator in the brushing work state, and “left” means the opposite direction.

  As described above, the protective cover unit of the present invention and the brush cutter provided with the same prevent the cutting blade from rotating and stopping the rotation by avoiding the cut object or the like from being wound around the output shaft. As a result, the safety and efficiency of the mowing work can be promoted.

It is a typical top view showing a brush cutter provided with a protection cover unit concerning one embodiment of the present invention. It is a right view which shows the mounting state of the protective cover unit of FIG. It is a left view which shows the mounting state of the protective cover unit of FIG. It is an enlarged plan view which shows the mounting state of the protective cover unit of FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.

  The brush cutter 1 shown in FIG. 1 mainly includes an operating rod 2, a gear case 3, a cutting blade 4, a protective cover unit 5, a connector 13, an engine unit 14, and a handle 15. The brush cutter 1 is configured such that the cutting blade 4 can be rotated counterclockwise to cut plants and the like.

  As shown in FIG. 2, the operation rod 2 has a tip connected to the mounting cylinder portion of the gear case 3. The operating rod 2 has an engine unit 14 at the rear end. The operating rod 2 has a U-shaped handle 15 near the center. The operation rod 2 has a scattering prevention cover 17 near the tip. The scattering prevention cover 17 is disposed so as to cover the rear side of the cutting blade 4. The operating rod 2 has a drive shaft (not shown) inserted therein. The tip of this drive shaft is connected to a drive side bevel gear of a bevel gear unit described later.

  As shown in FIG. 2, the gear case 3 has a bottomed cylindrical base tube portion and a mounting tube portion projecting obliquely upward from the base tube portion. The gear case 3 accommodates a bevel gear unit (not shown) inside. The bevel gear unit is connected to the drive shaft and rotates integrally therewith, a driven bevel gear disposed in mesh with the drive bevel gear, and the driven bevel gear fitted to the driven bevel gear. And an output shaft extending in the vertical direction.

  The cutting blade 4 is formed in a disk shape. The cutting blade 4 is attached to the lower end side of the output shaft, and is configured to be rotatable integrally with the output shaft. On the outer peripheral edge of the cutting blade 4, a plurality of blade portions are formed that are shaped like sawtooth teeth. The size of the cutting blade 4 is not particularly limited, but generally the diameter is about 230 mm to 260 mm and the thickness is about 1.0 to 1.5 mm.

  As shown in FIG. 2, the protective cover unit 5 includes an inner cover 6 and an outer cover 9.

  The inner cover 6 is formed in a bottomed cylindrical shape by the bottom wall 7 and the side wall 8. The inner cover 6 is attached to the upper surface of the cutting blade 4 on the output shaft of the bevel gear unit. The inner cover 6 is configured to be rotatable integrally with the output shaft. Although it does not specifically limit as the height of the side wall 8, It is preferable that it is 5 mm or more, and it is more preferable that it is 10 mm or more. If the height of the side wall 8 is smaller than the above range, there is a possibility that a cut object or the like entering between the cutting blade 4 and the outer cover 9 cannot be effectively blocked.

  The material for forming the inner cover 6 is not particularly limited, but generally, a synthetic resin or a metal can be used alone or in combination. Examples of the synthetic resin forming the inner cover 6 include polyethylene terephthalate, polyethylene naphthalate, acrylic resin, polycarbonate, polystyrene, polyolefin, cellulose acetate, weather resistant vinyl chloride, and the like. Moreover, as a metal which forms the inner cover 6, aluminum metal, a copper alloy, iron, steel, brass etc. can be mentioned, for example. The inner cover 6 can be reduced in weight by using a synthetic resin, while the rigidity can be kept high by using a metal.

  The outer cover 9 is formed in the shape of a shoe upper. The outer cover 9 is a semi-cylindrical main body 10 that covers the top of the gear case 3, the inner cover 6, and the front end of the operation rod 2, and extends from the front end edge of the main body 10 before the front side of the gear case 3 and the inner cover 6 is covered. A wall 11 and a side wall 12 extending from one side edge of the main body 10 and covering the gear case 3, the inner cover 6, and the cutting blade rotation direction side (left side in the present embodiment) of the tip of the operation rod 2 are provided. Yes. The lower end of the side wall 12 is fixed so as to be substantially parallel to the upper surface of the cutting blade 4. The outer cover 9 has a notch in a region opposite to the cutting blade rotation direction side (right side in the present embodiment). The outer cover 9 is disposed on the distal end side of the operation rod 2 via the connector 13. As a material for forming the outer cover 9, the same material as the inner cover 6 can be used.

  The connector 13 is attached to the distal end portion of the operating rod 2 by a pair of fixing screws. The connector 13 is fixed in a state substantially parallel to the upper surface of the cutting blade 4.

  As shown in FIGS. 2 and 3, the outer cover 9 and the connecting tool 13 include a pair of engaging holes at the rear of the outer cover 9 and a pair of engaging holes at both ends of the connecting tool 13. It is fixed by communication. The engagement hole of the outer cover 9 is formed in a substantially vertical slit shape.

  The protective cover unit 5 can adjust the height position of the outer cover 9 by changing the fixing position of the bolt in the engagement hole of the outer cover 9 formed in a slit shape. Thereby, regardless of the structure of the brush cutter 1, the protective cover unit 5 can keep the distance between the outer cover 9 and the cutting blade 4 optimal. Therefore, the protective cover unit 5 can effectively block cuts and the like entering the output shaft direction from below the outer cover 9.

  The protective cover unit 5 loosens the bolts and nuts, thereby moving the outer cover 9 from the base position (the lowest position as shown in FIGS. 2 and 3) with the axis of the bolt as the central axis. It can be easily rotated upward. The protective cover unit 5 can be easily re-fixed by returning the outer cover 9 to the base position and tightening the bolt and nut again. In this way, the protective cover unit 5 can relatively easily rotate the outer cover 9 about the axis of the bolt as the central axis and return it to the original state. Therefore, the protective cover unit 5 can easily perform maintenance, removal of cut objects, and the like in the cover.

Perpendicular distance _{d 2} from to the cutting blade 4 (the lower end of the front wall 11 and side walls 12) the lower end of the outer cover 9 is preferably 1mm or more 5mm or less, and more preferably 1mm or more 3mm or less. By adopting such a configuration, the protective cover unit 5 can greatly reduce the amount of cuts and the like that enter between the outer cover 9 and the cutting blade 4 and enter the output shaft direction. It is possible to reduce a risk that a cut object or the like is wound around the output shaft.

  The engine unit 14 is disposed at the rear end of the operation rod 2. The engine unit 14 is configured to be able to transmit power to the drive shaft.

  The handle 15 is disposed near the center of the operation rod 2. The handle 15 is formed in a U shape and has a pair of grips at both ends. The handle 15 has an operation lever 16 on the right grip. The operation lever 16 is configured to be able to adjust the power driven by the engine unit 14.

  The protective cover unit 5 can prevent the cut matter or the like from being wound around the output shaft by the inner cover 6 and the outer cover 9 in a double manner. Therefore, the protective cover unit 5 can remarkably reduce a possibility that the rotational speed of the cutting blade 4 is lowered or the rotation is stopped when a cut object or the like is wound around the output shaft. As a result, the protective cover unit 5 can dramatically improve the safety and efficiency of the brushing work. Moreover, since the outer cover 9 covers the upper part of the gear case 3 and the inner cover 6 in the protective cover unit 5, it is possible to prevent vegetation and the like from entering the output shaft from above.

  Next, the brushing operation and effects of the brush cutter 1 will be described. The brush cutter 1 operates the operation lever 16 provided on the handle 15 so that the power from the engine unit 14 is transmitted to the output shaft through the drive shaft, the driving side bevel gear, and the driven side bevel gear. And the cutting blade 4 connected with the output shaft also rotates with rotation of an output shaft. On the other hand, in the brush cutting work by the brush cutter 1, the vegetation or the like is usually cut by a blade portion of the cutting blade 4 positioned in front of the brush cutter 1. Therefore, most of the cut objects move toward the cutting blade rotation direction.

  In the protective cover unit 5, as shown in FIG. 2, the outer cover 9 has a notch on the side opposite to the cutting blade rotation direction side. However, as described above, most of the cut objects and the like move toward the cutting blade rotation direction. Therefore, even if the notch portion is formed on the side opposite to the cutting blade rotation direction side, there is almost no possibility that a cut object or the like enters from the notch portion and winds around the output shaft. Therefore, the protective cover unit 5 can effectively cut off a cut object or the like by the front wall 11 or the side wall 12 of the outer cover 9. On the other hand, the protective cover unit 5 can easily discharge cuts and the like that have passed between the outer cover 9 and the cutting blade 4 and have entered the output shaft direction by forming such a notch. it can. As a result, the protective cover unit 5 can easily create a state in which a cut object or the like does not exist around the output shaft during the mowing operation, and the rotational speed of the cutting blade 4 by winding the cut object or the like around the output shaft. It is possible to more effectively prevent the decrease in rotation and the stop of rotation.

  In addition, as shown in FIGS. 2 to 4, in the protective cover unit 5, the side wall 12 of the outer cover 9 is formed substantially linearly on the cutting blade rotation direction side, and the front wall 11 and the side wall 12 of the outer cover 9 are formed. The outer periphery is configured to be smaller than the outer periphery of the cutting blade 4. Therefore, according to the protective cover unit 5, a cut object or the like cut by the cutting blade 4 and loaded on the upper surface of the cutting blade 4 is smoothly discharged to the ground or the like without being obstructed by the external cover 9. The As a result, the protective cover unit 5 can prevent the cut material and the like from excessively staying in the cutting blade rotation direction side and pass between the outer cover 9 and the cutting blade 4 in the output shaft direction. It is possible to reduce the number of cuttings that enter.

The positional relationship between the inner cover 6 and the outer cover 9 will be described with reference to FIGS. The inner cover 6 and the outer cover 9 (base position) are such that the normal distance d ₁ from the upper end of the inner cover 6 to the cutting blade 4 is greater than the normal distance d ₂ from the lower end of the outer cover 9 to the cutting blade 4. It is configured to be large. Therefore, the protective cover unit 5 can effectively block the cut matter or the like that has entered the output shaft direction through the space between the outer cover 9 and the cutting blade 4 by the side wall 8 of the inner cover 6. Moreover, as a relationship between d ₁ and d ₂ , it is more preferable that d ₁ > 2d ₂ . In this way, the normal distance d ₁ from the upper end of the inner cover 6 to the cutting blade 4 is set to be twice or more the normal distance d ₂ from the lower end of the outer cover 9 to the cutting blade 4, so that the protective cover unit 5 can more effectively block a cut object or the like that has passed between the outer cover 9 and the cutting blade 4 by the side wall 8 of the inner cover 6.

  In addition, the protective cover unit of this invention and the brush cutter provided with this can be implemented in the aspect which gave various change and improvement other than the said aspect. For example, in the above aspect, the brush cutter that cuts plants and the like when the cutting blade rotates counterclockwise has been described. However, with respect to the brush cutter that cuts the plants and the like when the cutting blade rotates clockwise, the above aspect and the horizontal direction are described. The reverse mode can be adopted. Further, the operation lever may be disposed on the left grip for a left-handed person. The outer cover and the connector need not be fixed by bolts and nuts, and may be fixed from both side surfaces by a pair of screws.

  As described above, the protective cover unit of the present invention and the brush cutter provided with the same prevent the cutting blade and the like from being wound around the output shaft, thereby preventing the rotation speed of the cutting blade from decreasing and stopping the rotation. Therefore, it is suitable for promoting the safety and efficiency of the mowing work. Therefore, the protective cover unit and the brush cutter provided with the protective cover unit can be widely used for home use and business use.

1 Brush cutter 2 Operation rod
DESCRIPTION OF SYMBOLS 3 Gear case 4 Cutting blade 5 Protective cover unit 6 Internal cover 7 Bottom wall 8 Side wall 9 External cover 10 Main body 11 Front wall 12 Side wall 13 Connecting tool 14 Engine part 15 Handle 16 Operation lever 17 Scatter prevention cover d ₁ Cutting from upper end of internal cover Normal distance to the blade d ₂ Normal distance from the lower end of the outer cover to the cutting blade

Claims (4)

An operating rod for inserting the drive shaft, a gear case attached to the tip of the operating rod and housing the bevel gear unit connected to the drive shaft, and disposed below the gear case and fixed to the output shaft of the bevel gear unit A protective cover unit to be attached to a brush cutter provided with a disk-shaped cutting blade,
A cylindrical inner cover with a bottom attached to the upper surface of the cutting blade in the output shaft of the bevel gear unit;
An outer cover in the form of a shoe upper disposed above the gear case so as to cover the gear case, the inner cover, and the tip of the operating rod;
A protective cover unit comprising: a connecting tool for connecting the outer cover to the operating rod. The outer cover is
A semi-cylindrical body that covers the top of the gear case, the inner cover, and the tip of the operation rod;
A front wall extending from the front edge of the main body and covering the front side of the gear case and the inner cover;
The protective cover unit according to claim 1, further comprising: a side wall extending from one side edge of the main body and covering a gear blade, an inner cover, and a cutting blade rotation direction side of a tip portion of the operation rod. As a means for engaging the outer cover and the connecting tool, a pair of engaging holes at the rear of the outer cover, a pair of engaging holes at both ends of the connecting tool, and bolts and nuts connected to and fixed to these engaging holes are provided. ,
A pair of engagement holes of the outer cover are configured in a substantially vertical slit shape,
The protective cover unit according to claim 1 or 2, wherein a height position of the outer cover is configured to be variable by changing a bolt position in the pair of slit-like engagement holes. An operating rod to interpolate the drive shaft;
A gear case that is attached to the tip of the operating rod and houses a bevel gear unit connected to the drive shaft;
A disc-shaped cutting blade disposed below the gear case and fixed to the output shaft of the bevel gear unit;
An engine unit arranged at the rear end of the operating rod and configured to transmit power to the drive shaft;
A bottomed cylindrical inner cover attached to the upper surface of the cutting blade in the output shaft of the bevel gear unit;
An outer cover in the shape of a shoe upper disposed above the gear case so as to cover the gear case, the inner cover, and the tip of the operating rod;
A brush cutter comprising: a connecting tool for connecting the outer cover to the operating rod.

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