JP2015082991A - Striking tool - Google Patents

Abstract

【Task】
Provided is a striking tool (weeding machine) that can efficiently perform weeding work by applying a striking force to a blade using a striking mechanism.
[Solution]
The battery 10, the motor 3 driven by the battery, the switch 108 for controlling the driving of the motor 10, the handle 120 gripped by the operator, the long handle 140 interposed between the handle and the motor, and the tip side An impact tool (weeding machine) 100 having a blade holding part 60 that holds a blade 90 having a taper in a reciprocating manner and an impact transmitting part 101 that applies the rotational force of the motor as an impact force to the blade is provided. The blade 90 is given a striking force as indicated by an arrow 165 by the striking transmission portion 101.
[Selection] FIG.

Description

  The present invention relates to a striking tool suitable for driving a blade or the like that cuts and cuts grass roots, and in particular, by operating an impact mechanism using a rechargeable battery, the reaction force can be reduced by using the impact on the blade. In addition, the working efficiency is improved by making it easier to feed the blade parallel to the ground.

  Weeds can grow either when they are taken or removed, and it is extremely difficult to remove weeds from gardens, flower beds, parks, grounds, farmland, golf courses, etc. in residential areas. Brush cutters and weeding sickles are often used in places other than where large weeders are used or where herbicide spraying is allowed. It is ideal to remove the entire roots of weeds, but it is often difficult to extract the roots of weeds because of the hard ground, deep roots and large roots. As a compromise for this, cutting off the stem part is performed. In this case, a mowing sickle or a brush cutter is used. Since the period until the weeds are regenerated is short, the work must be done frequently, and the appearance is not good.

  In addition to cutting off the stem part, the roots of weeds are also cut off at a depth of about 1 to 5 centimeters from the ground surface. In this work, weeding sickle is widely used. In this case, the period until the weeds regenerate is longer than when the stem portion is cut and the appearance is good. However, since the weeding work using the weeding sickle is a manual work, the body fatigue is large and the work for a long time is difficult. Therefore, in the prior art, as disclosed in Patent Document 1, there is known a technique for increasing the power of cutting by using a chip saw tip of a brush cutter that has been improved for cutting. .

  On the other hand, cordless type brush cutters and mowing machines that drive motors with electric energy stored in batteries have become widespread. These drive a brushless DC motor using a battery as disclosed in, for example, Patent Document 2. A brushless DC motor is a DC (direct current) motor without a brush (rectifying brush). A coil (winding) is used on the rotor side, a permanent magnet is used on the stator side, and the power driven by the inverter is supplied to a predetermined coil. The rotor is rotated by energizing sequentially. A brushless motor is more efficient than a motor with a brush, and a long working time can be secured while using a rechargeable secondary battery.

JP 2001-148920 A JP 2010-200673 A

  In the conventional brush cutter disclosed in Patent Document 1, a large reaction force is generated because the tip saw sinks into the ground. However, since there is no reaction force reduction mechanism, a large reaction force is transmitted to the operator's arm. Further, since the peripheral speed of the tip saw is high, there arises a problem that pebbles, soil and weeds are likely to be scattered. Furthermore, since weed collection work after weed cutting is difficult, how to reduce these problems has become a problem. In addition, when using the brush cutter of Patent Document 2, since it is a cordless electric type, handling is easy and workability is improved, but due to the duration of the battery, output, and the like, it becomes a mowing work on the ground. Therefore, there is a problem that the period until the weeds are regenerated is short.

The present invention has been made in view of the above background, and an object thereof is to provide a striking tool that is an electric cordless type and is suitable for scraping a weed root at a depth of about 1 to 5 centimeters from the ground surface. It is in.
Another object of the present invention is to provide a striking tool that reduces the reaction force caused by weeding and the like, and also eliminates scattering of pebbles, soil and weeds and facilitates the weed collecting work after weeding.
Still another object of the present invention is to provide a striking tool that can efficiently perform a grass cutting operation or the like by applying a striking force to a blade using a striking mechanism.

The characteristics of representative ones of the inventions disclosed in the present application will be described as follows.
According to one aspect of the present invention, a battery, a motor that drives the battery as a drive source, a switch that controls driving of the motor, a handle that is gripped by an operator, and a long handle that is interposed between the handle and the motor An impact tool having a portion, a blade holding portion that holds the blade so as to be able to reciprocate, and an impact transmission portion that applies the rotational force of the motor as an impact force to the blade. The handle is provided on one end side of the long handle portion, and the impact transmission portion and the blade holding portion are provided on the other end side of the long handle portion. A switch and a battery are provided on the handle, and a motor is provided on the other end side of the long handle.

  According to another feature of the present invention, the tip of the cutter has a linear shape, and the cutter holder holds the cutter in a non-rotatable state so that the linear shape of the tip of the cutter extends so as to be orthogonal to the axial direction of the long handle. did. It is desirable that the line connecting the blade tips of the blade and the axial direction of the long handle portion intersect each other. Further, the crossing angle between the reciprocating direction of the blade and the axial direction of the long handle portion was configured to be 90 degrees or less. Here, it is more preferable that the intersecting angle between the reciprocating direction of the blade and the axial direction of the long handle portion can be adjusted and fixed.

  According to still another feature of the present invention, the sub handle is provided on the long handle portion between the handle and the hitting transmission portion. The sub handle and the handle may be arranged on the axis of the long handle, and the sub handle is particularly preferably arranged on the handle side with respect to the center of gravity of the entire tool. It is preferable that the sub handle can be fixed at an arbitrary position of the long handle part and / or the long handle part can be expanded and contracted.

  According to still another feature of the present invention, biasing means for biasing the blade toward the tip side is provided, and the hammer transmitting portion strikes the blade while the blade is retracted against the biasing force of the biasing means. Transmit power. The impact transmission unit has a hammer portion that rotates by receiving the rotational force of the motor through elastic means and has a rotation axis that intersects the reciprocating direction of the blade. In addition, it is preferable that the blade holding part is detachable with no tool.

ADVANTAGE OF THE INVENTION According to this invention, the striking tool which enabled it to perform grass cutting work etc. efficiently by giving striking force to a blade using a striking mechanism can be provided.
The above and other objects and novel features of the present invention will become apparent from the following description and drawings.

It is a top view of the weeding machine which concerns on the Example of this invention. It is a longitudinal cross-sectional view which shows the whole structure of the weeding machine based on the Example of this invention, Comprising: It is sectional drawing of the AA part of FIG. It is a front view of the weeding machine which concerns on the Example of this invention. FIG. 3 is a partial cross-sectional view in the vicinity of the striking mechanism of FIG. 2. FIG. 2 is a partially enlarged view of the vicinity of a striker mechanism 50 in FIG. 1. It is a figure which shows the shape of the striking rod 51 of FIG. 1, (1) is a top view, (2) is a side view, (3) is a rear view. It is a figure for demonstrating the hit | damage operation | movement to the hit | damage rod 51 by the rotation hammer 34 of FIG. (1) is a top view of the blade holder 70 alone, and (2) is a partially enlarged view of portion B in FIG. It is a figure which shows the detailed shape of the braid | blade 90 of FIG. 1, (1) is a top view which shows the whole, (2) is sectional drawing of the DD section of (1). (3) is a partial top view which shows the shape of the blade edge of another form, (4) is sectional drawing of the EE part of (3). It is a figure for demonstrating the relationship between the shape of a braid | blade, and the blade angle | corner (beta). It is a figure for demonstrating the weeding operation | work using a weeding machine. It is a figure for demonstrating the relationship between the penetration angle by a braid | blade, and a clearance angle. It is a side view of the weeding machine 100 which concerns on the 2nd Example of this invention, and shows one part with sectional drawing. It is a top view of the weeding machine 100 which concerns on the 2nd Example of this invention. It is a side view of the weeding machine 200 which concerns on the 1st modification of the 2nd Example of this invention, and shows one part with sectional drawing. It is a side view of the weeding machine 300 which concerns on the 2nd modification of the 2nd Example of this invention, and shows one part with sectional drawing. It is a side view of the weeding machine 400 which concerns on the 3rd modification of the 2nd Example of this invention, and shows one part with sectional drawing. It is a side view of the weeding machine 500 concerning the 3rd example of the present invention, and a part is shown with a sectional view. It is a side view of the weeding machine 600 which concerns on the 4th Example of this invention, and shows one part with sectional drawing. It is an expanded sectional view of the main-body part 601 of FIG. It is a figure for demonstrating the engagement condition of the connecting rod 653 and eccentric cam 628 of FIG. It is a figure for demonstrating the kind of blade edge | tip used for the weeding machine which concerns on this invention.

  Embodiments of the present invention will be described below with reference to the drawings. In the following description, each direction is based on the direction when the operator grips the weeding machine and takes a working posture, and the up / down / left / right and front / rear directions are described as directions shown in the drawing. FIG. 1 is a top view of a weeding machine according to an embodiment of the present invention. In the present embodiment, the impact tool has a novel shape in which a blade holder 60 is attached to the tip of an electric tool (corresponding to the main body 1) widely used as a so-called impact driver, It can be used as a weeding machine by providing a blade for weeding.

  The weeding machine uses a rechargeable battery 10 as a power source, and an electric motor (described later) housed in the housing 2 as a drive source. The blade holder applies a striking force to the striking rod 51 and is movable in the front-rear direction. A striking force is applied to the blade 90 detachably attached to the tip of the 70. The blade 90 attached to the tip of the blade holder 70 has a blade formed at the tip, and is attached to the blade holder 70 with screws and nuts (76 to 79). The blade 90 having the blade tip formed obliquely is pressed against the grass root or the like, and the operator can cut the grass root or the like by pulling a trigger described later. The blade holder 70 and the blade 90 constitute the blade of the present invention. The housing 2 is a molded product made of a synthetic resin such as plastic and can be divided into two in the left-right direction, and has a so-called gun type shape, similar to a power tool widely used as an impact driver. The housing 2 is mounted with a substantially cylindrical body portion 2a for accommodating a motor and a striking mechanism, a grip portion 2b for an operator to hold with one hand, and a detachable battery 10 connected to the lower end of the grip portion 2b. It is mainly composed of three parts, a battery mounting part 2c for performing the above. A hammer case 41 is provided on the front end side in the axial direction of the body portion 2a (the lower end side when viewed in FIG. 1).

  The hammer case 41 is a metal case for accommodating a rotary hammer and a striking rod 51 described later, and functions as a fixing member for holding the blade holder 60. The hammer case 41 is preferably manufactured by metal integral molding, but may be manufactured by either metal or synthetic resin integral molding or separate molding. In this embodiment, the hammer case 41 is fixed to the housing 2 with four screws 47a to 47d. In addition, the fixing method of the hammer case 41 and the housing 2 is not limited to fixing with the screws 47a to 47d, but may be sandwiched between the left and right split type housings 2, or other known fixing methods may be used. good. The striking rod 51 applies a plurality of striking continuously in the direction of the arrow 65, and a hit portion 70 a that is hit by the striking element 52 of the striking rod 51 is formed at the rear end portion of the blade holder 70. The hit portion 70 a is formed by reducing the width in the left-right direction by matching the rear end portion of the plate-like blade holder 70 to the lateral width of the striker 52.

  The blade holder 70 is a rod-like member that is held so as to be movable by a predetermined distance in the front-rear direction as indicated by an arrow 66 with respect to the upper arm 80 and the lower arm 61, and has a blade holding portion at the tip thereof. 70d is formed. The blade holding portion 70d is an attachment base for fixing the blade 90 with two screws 76 and 78 and nuts 77 and 79, and has a predetermined width in the lateral direction (left and right direction) according to the shape of the blade 90. The blade 90 is held so that the cutting edge of the blade 90 is disposed obliquely at a predetermined angle with respect to the axial direction of the blade holder 70. The blade holder 70 is fixed to the upper arm 80 and the lower arm 61 by screws 82 and 85, and elongated holes 70b and 70c are formed in a portion of the blade holder 70 through which the screws 82 and 85 pass.

  FIG. 2 is a longitudinal sectional view showing the entire structure of the weeding machine according to the embodiment of the present invention, and is a sectional view taken along the line AA of FIG. The body portion 1 of the weeding machine has a striking direction by rotating a rotary hammer 34 with a reduced rotational force and a motor 3 as a drive source, a speed reduction mechanism (speed reduction portion) 20 for reducing the output of the motor 3 The impact mechanism 30 that strikes the drum and the striker mechanism 50 that is struck by the rotary hammer 34 are housed in the housing 2 and the hammer case 41. Here, the impact mechanism 30 and the striker mechanism 50 serve as an impact transmission unit that applies the rotational force of the motor 3 to the blade 90 as an impact force. The housing 2 has a grip portion 2b extending in a vertical direction from the substantially cylindrical body portion 2a. The battery mounting portion 2c at the front end (rear end in FIG. 2) of the grip portion 2b is in a pack form and is detachable. A battery 10 is provided. A secondary battery such as a nickel-cadmium battery or a lithium ion battery is used for the battery 10. By attaching the battery 10 to the battery mounting portion 2c, the battery electrode (not shown) comes into contact with the terminal 11 so that the electric power from the battery 10 can be supplied to the motor 3 side. A switch 8a for controlling the driving of the motor and a trigger 8 for operating the switch 8a are disposed in the upper part of the grip 2b extending integrally from the body 2a of the housing 2 at a substantially right angle. Mounted on or connected to. A control circuit board 9 having a function of controlling the speed of the motor 3 by the pulling operation of the trigger 8 is accommodated in the lower part in the grip portion 2 b. The control circuit board 9 is electrically connected to the battery 10 and the switch circuit board 7. Connected. The control circuit board 9 is connected to the inverter circuit board 6 through a signal line. Near the front upper side of the battery mounting portion 2c of the housing 2, there is provided an operation panel 12 in which a mode changeover switch for setting the impact strength, a switch for checking the battery remaining amount, LED display means and the like are arranged. .

  The blade holder 60 holds a blade holder 70 having a blade 90 attached to the tip thereof so as to be able to reciprocate. The blade holder 60 includes a lower arm 61 fixed to the hammer case, and an upper arm 80 fixed to the lower arm 61 by screws 82 and 85 and nuts 83 and 86. The upper arm 80 and the lower arm A blade holder 70 is sandwiched between 61. The upper arm 80 has a substantially U-shaped cross section perpendicular to the longitudinal direction, and the lower arm 61 is plate-shaped and is made of metal or synthetic resin, and is fixed to the hammer case 41 with screws 62 and 64. Is done. Slots 70b and 70c are formed in the blade holder 70 at the screwing locations of the upper arm 80 and the lower arm 61, and the upper arm 80 and the lower arm 61 are kept at a predetermined interval inside the elongated holes 70b and 70c. Thus, distance pieces 84 and 87 are interposed. The distance pieces 84 and 87 are cylindrical members having an axial length slightly longer than the plate thickness of the blade holder 70, whereby the upper arm 80 and the lower arm 61 are positioned so as to be spaced apart from each other. In between, the blade holder 70 can be slid well. The tip of the blade holder 70 serves as an attachment base for attaching the blade 90 having the attachment step 90d and the attachment surface 90c. By holding the blade holder 70 in this manner, the blade 90 can reciprocate in the range of the long holes 70 b and 70 c of the blade holder 70. In addition, the entire blade holding unit 60 can be easily disassembled and cleaned by connecting the lower arm 61 to the striking mechanism. Since the blade 90 can be removed from the blade holder 70, the blade 90 can be easily replaced or sharpened. Furthermore, it becomes easy to remove the entire blade holding part 60 from the main body part 1, wash the water and remove the adhering soil and apply the lubricant.

  FIG. 3 is a front view of the weeding machine according to the embodiment of the present invention. The housing 2 of the weeding machine is formed by dividing the housing 2 into two in the left-right direction. The hammer case 41 has four screws 47a to 47d (47c and 47d in FIG. Attached). The lower arm is fixed to the lower end side of the hammer case 41 by screws 62 and 64 (see FIG. 2 for 62), and the blade 90 is fixed to the tip of the lower arm 61 by two screws 76 and 78 and nuts 77 and 79. The Two screws 58 and 59 are further fixed to the lower end of the hammer case 41, and these screws are used for fixing a striker cover (not shown). Here, in the present embodiment, the spindle 31 is disposed so that the axial direction of the body portion 2a of the housing 2 and the axial direction of the motor 3 are the same direction, and the center position in the left-right direction of the axis extending the rotating shaft 3d of the motor 3 On the other hand, the axial position of the striking rod 51 is arranged so as to be offset to one side (right side) as shown. This is because the tangential direction of the rotation trajectory of the protrusion of the rotary hammer 34 (see FIG. 2) is arranged so that the axis of the striking rod 51 coincides. The impact mechanism 30 can also be arranged so that the offset amount in the left-right direction is zero. In this case, the rotation axis of the rotary hammer 34 is more than the center line in the left-right direction of the housing 2 (or the axis of the motor 3). They may be arranged so as to be shifted from each other, or may be arranged so that the rotation axis of the rotary hammer 34 is orthogonal to the axis of the motor 3 using gear means.

  FIG. 4 is a partial cross-sectional view of the vicinity of the striking mechanism of FIG. The motor 3 is a brushless DC motor housed in a cylindrical body 2a of the housing 2, and has a rotor 3a in which two sets of magnets 3c are arranged on the inner peripheral side, and is wound around six slots on the outer peripheral side. A stator 3b around which a wire is wound is disposed, which is a so-called 4-pole 6-slot motor. The types of motors used are not limited to motors with four poles and six slots, but may be motors with other pole numbers and other slot numbers. The rotating shaft 3d of the motor 3 is rotatably held by a bearing 19a provided near the center of the body 2a of the housing 2 and a bearing 19b on the rear end side, and coaxially with the rotating shaft 3d in front of the motor 3. A cooling fan 14 that is attached and rotates in synchronization with the motor 3 is provided. By the air flow generated by the cooling fan 14, the outside air is taken into the housing 2 from the air intake ports 17a and 17b and other air intake ports (not shown), and flows mainly between the rotor 3a and the stator 3b. After that, the air is discharged out of the housing 2 through an air discharge port (not shown). Behind the motor 3 is disposed an inverter circuit board 6 on which an inverter circuit for driving the motor 3 and converting a direct current into a predetermined alternating current is converted. The inverter circuit board 6 is a substantially circular double-sided board that is substantially the same as the outer shape of the motor 3, and a plurality of switching elements 13 such as field effect transistors (FETs) and a position detection element 15 such as a Hall IC are provided on the board. Installed.

  The rotation shaft 3d of the motor 3 is provided with a speed reduction mechanism 20 using a planetary gear. The speed reduction mechanism 20 includes a sun gear 21 attached to the rotating shaft 3d, a ring gear 24 disposed on the outer peripheral side, and a plurality of planetary gears 22 rotating between them. The rotating shaft 23 of the planetary gear 22 is held by a spindle 31 that also serves as a planet carrier. The impact mechanism 30 serves as a livestock force means provided on the output side of the speed reduction mechanism 20, and receives and rotates the rotational force of the motor 3 via an elastic means (hammer spring 33), and rotates to intersect the reciprocating direction of the blade. A hammer portion (rotating hammer 34) having an axis is provided. A rear end of the impact mechanism 30 is rotatably held by the bearing 18 and a front end of the impact mechanism 30 is rotatably held by the bearing 37. The spindle 31 and the rotary hammer 34 are connected by a cam mechanism. The cam mechanism is formed on the spindle cam groove 31a formed in the outer peripheral surface of the spindle 31 in a side view and the inner peripheral surface of the rotary hammer 34. The formed hammer cam groove 34a has a substantially convex shape in a side view, and the spindle cam groove 31a and the steel ball 32 engaged with the hammer cam groove 34a. The rotary hammer 34 is always urged forward by a hammer spring 33. When the rotary hammer 34 is stationary, the rotary hammer 34 is positioned on the lower side by the engagement of the steel ball 32 with the spindle cam groove 31a and the hammer cam groove 34a. Projections 35 projecting in the axial direction are formed at two positions separated by about 180 degrees in the rotational direction on the front end surface (the lower side surface in the drawing) of the rotary hammer 34. The projection 35 is a hammer claw for striking that protrudes in the axial direction and on the opposite side of the motor from the front end surface (lower end surface in FIG. 4) of the substantially cylindrical rotary hammer 34, and this projection 35 collides with the striking rod 51. Thus, the rotational impact force of the motor 3 can be converted into the impact force. When the hitting rod 51 is not pressed during the rotation of the rotary hammer 34, the rotary hammer 34, the protrusion 35, and the end of the hitting rod 51 are in a positional relationship. Protrusions 35 are preferably provided at two locations that are rotationally symmetric, since it is easy to balance the rotation of the rotary hammer 34. However, it is also possible to increase the impact torque by providing it at only one location.

  When the striking rod 51 is struck by the rotary hammer 34, it moves in the direction of the arrow 65, that is, in the direction perpendicular to the rotation shaft 3d of the motor 3. At this time, if the blade holder 70 is pressed against the striker 52, a strong striking force is transmitted to the blade holder 70. FIG. 4 illustrates a state in which the blade holder 70 is pressed against the striker 52, and the striker 52 and the rear end portion (struck portion 70a) of the blade holder 70 are in contact with each other. When the reaction force (pressing force) from the blade holder 70 does not act in this way, the end of the striking rod 51 is held at a position where it does not come into contact with the protrusion of the rotary hammer 34 by the action of the rod spring 43. When the pressing force is applied, that is, when the striking rod 51 is pressed rearward and the rod spring 43 contracts, the positional relationship is such that the projection 35 of the rotary hammer 34 and the striking rod 51 come into contact with each other. The rod spring 43 urges the blade holder 70 toward the distal end side via the striking rod 51, and the rod spring 43 is an urging means for urging the cutter in the present invention toward the distal end side.

  When the trigger 8 is pulled and the motor 3 is activated, the rotational force is decelerated by the speed reduction mechanism 20 and transmitted to the spindle 31, and the spindle 31 starts to rotate at a predetermined speed. When the operator grips the weeding machine and presses the blade 90 against earth or sand or weeds, the blade 90 is pushed back, so that the blade holder 70 moves backward (in a direction approaching the striking rod 51). The reaction force from the striking rod 51 is determined by how much force the operator presses against the object to cut the weeding machine. When the reaction force from the striking rod 51 is greater than or equal to a predetermined strength, the rotation of the projection 35 is blocked by the striking rod 51, and therefore the rotation of the rotary hammer 34 is rapidly decelerated when they come into contact with each other. At the same time, when the rotating hammer 34 engaged by the steel ball 32 moves following the cam grooves 31a, 34a, the hammer spring 33 contracts, and the rotating hammer 34 retracts in the direction of the rotation axis (in FIG. 2, upward). Moving. This backward movement fulfills a so-called animal power action. When the amount of backward movement reaches a certain level, the contact state between the one projection 35 and the rear end portion of the striking rod 51 is released, and the rotary hammer 34 rotates the rotational force of the spindle 31. In addition to the elastic energy accumulated in the hammer spring 33 and the cam mechanism, it is rapidly accelerated in the rotational direction and the forward direction (downward in FIG. 2), and moved forward by the urging force of the hammer spring 33. When one projection 35 strikes the rear end portion of the striking rod 51 strongly, a powerful striking force for moving the striking rod 51 forward (blade 90 side) is given. Since the striker 52 strikes the hit portion 70 a of the blade holder 91 by this impact, the impacted rod holder indirectly moves with respect to the blade 90 by instantaneously moving the impacted blade holder 70 in the direction of the arrow 65. The striking force of 51 is transmitted, and the blade 90 can effectively cut grass roots and stems. Thereafter, the same operation is repeated, and the striking force is transmitted from the striking rod 51 to the blade 90 via the blade holder 70. This striking operation is performed, for example, about 50 to 500 times / second when the striking rod 51 is always located on the rear side of FIG.

  The gear case 27 is an envelope that accommodates a part of the speed reduction mechanism 20 and the impact mechanism 30, and is manufactured by metal integral molding, to which a hammer case 41 is connected. The central axis of the gear case 27 and the hammer case 41 are orthogonal to each other with a distance corresponding to the radius of the rotary hammer 34. The hammer case 41 accommodates most of the striking rod 51 and a part of the rotary hammer 34 therein, and a cylindrical holding portion for holding a bearing 37 such as metal inside the hammer case 41. 41a is formed, and the tip shaft 31b of the spindle 31 is pivotally supported via a bearing 37 that is inserted into the holding portion 41a. Furthermore, a bearing 42 made of metal or the like that holds the striking rod 51 in a reciprocating manner is attached to a through hole 41b formed in the hammer case 41 and extending in the radial direction of the cylindrical body portion 2a. The hammer case 41 is preferably manufactured from a molded product of aluminum or iron-based metal from the viewpoint of strength. An elongated hole 50e is provided at an intermediate point in the axial direction (corresponding to the front-rear direction in this case) of the striking rod 51 so that the striking rod 51 does not fall out while allowing the striking rod 51 to reciprocate. The tip of the load stopper 44a tightened from the outside is positioned. The front end portion of the striking rod 51 has a large diameter, and a striking member 52 having a striking surface on the front side is formed. The diameter of the portion of the striker 52 is increased in order to receive one end of the rod spring 43. In the present embodiment, the striking rod 51 and the striking element 52 are manufactured as an integrated product of an iron-based alloy, but the configuration is not limited to the integrated product, and these may be configured by assembling a plurality of parts. Near the center of the direction of movement of the striking rod 51, a ring holding groove 51f is provided, and an oil seal 46 is interposed therein, so that when the striking rod 51 is reciprocated, the space from which the rotary hammer 34 is accommodated to the outside. The lubricant is prevented from flowing out, and the earth and sand that are scattered and floated by the weeding of the weeds are prevented from entering the housing 2.

  A blade holder 70 is held on the front side of the striking rod 51 so as to be movable in the front-rear direction as indicated by an arrow 66. The lower arm 61 is screwed to the hammer case 41 with a plurality of screws 62 and 64, and the blade holder 70 is held so as to be sandwiched between the lower arm 61 and the upper arm 80. The lower arm 61 and the upper arm 80 are immovable members with respect to the housing 2, and are movable members with which the blade holder 70 can move relative to the housing 2. The lower arm 61 and the upper arm 80 are fixed by screws 82 and nuts 83, and a cylindrical distance piece 84 is disposed in order to keep the distance between the lower arm 61 and the upper arm 80 constant. The blade holder 70 itself can move relative to the lower arm 61 and the upper arm 80 within the range of the elongated hole 70c (see FIG. 1), but is not restricted by movement by a spring or the like. In this embodiment, for the sake of explanation, an example in which the rear end of the striker 52 and the blade holder 70 is exposed is shown. However, in an actual product, this portion is covered with a cover (batterer cover). It is preferable that the rear end portions of the cover striker 52 and the blade holder 70 are not touched by branches.

  FIG. 5 is a partially enlarged view of the vicinity of the striker mechanism 50 of FIG. 1 and shows a part of the strike rod 51 in a cross-sectional view. The hammer case 41 has a function of covering the front side in the axial direction of the rotary hammer 34, a function of supporting the tip shaft 31 b of the spindle 31, a function of supporting the striking rod 51 so as to reciprocate, and mounting of the lower arm 61. A function as a base and a function as an attachment base of a cover (not shown) for covering the contact portion between the striker 52 and the blade holder 70 are provided. The shape of the bearing 42 is a cylindrical shape, but a flange portion 42a formed so as to spread outward in the radial direction is formed at the front end portion. A rod spring 43 is inserted between the striking rod 51 and the flange portion 42a of the bearing 42 to urge the striking rod 51 forward (blade 90 side). Grooves 51d and 51e are formed on the left and right sides near the middle when viewed in the axial direction of the striking rod 51. The groove portions 51d and 51e are used to prevent the striking rod 51 from coming off and prevent rotation, and a rod stopper 44a that passes through the screw hole 42b of the bearing 42 and is fixed to the screw hole 41c provided in the hammer case 41 enters the groove portion 51e. A rod stopper 44b, which is similarly provided on the side facing the stopper 44a, is structured to enter the groove 51d. Screws can be used as the rod stoppers 44a and 44b, and the tip portions of the rod stoppers 44a and 44b are located inside the groove portions 51d and 51e, so that the axial movement of the striking rod 51 can be restricted. The striking rod 51 can reciprocate within the range of the axial length of the groove 51d. In a state where no force is applied to the striking rod 51 from the outside, that is, in a state where the striking rod 51 is not pushed by the blade holder 70, the striking rod 51 is held at the stop position located on the front side. The blade holder 70 is a movable member that can move relative to the non-moving members such as the lower arm 61 and the upper arm 80 in the front-rear direction (longitudinal direction), and is formed in a convex shape on the rear end side as viewed from above. The hit portion 70a thus formed is formed. In FIG. 5, unlike the state of FIG. 1, the blade holder 70 has moved forward, so that the collision surface is not in contact even when the striking rod 51 is in the foremost position. In this way, the striker 52 of the striking rod 51 and the hit portion 70a of the blade holder 70 are held so as to be separable, so that a force pressing the blade holder 70 rearward is applied to push the striking rod 51 rearward. When the hitting rod 51 is hit by the rotary hammer 34, an effective hitting force can be applied to the blade holder 70.

  6 is a view showing the shape of the striking rod 51 of FIG. 1, wherein (1) is a top view, (2) is a side view, and (3) is a rear view. The striking rod 51 is a substantially columnar member that is manufactured integrally with the striking element 52 by metal cutting or the like, and its rear end side (the end portion closer to the axis of the rotating shaft 3d of the motor 3) is A hammer striking surface 51a that is substantially perpendicular to the axis of the striking rod 51 is formed, and a relief surface 51b and a sliding surface 51c are formed adjacent to the hammer striking surface 51a. The relief surface 51b is not subjected to external force on the striking rod 51, and does not come into contact with the protrusion 35 of the rotary hammer 34 when being held at the stop position located on the front side. 34 is provided so that it can idle, and the corner portion of the end face of the striking rod 51 is cut off obliquely. This oblique cut-off angle θ is preferably set to an angle along the outer edge of the rotation locus of the protrusion 35 of the rotary hammer 34. The sliding surface 51c is formed so that the rotating hammer 34 can continue to rotate by rubbing the sliding surface 51c of the striking rod 51 when the rotating hammer 34 retreats while compressing the hammer spring 33. It is a stepped surface. The sliding surface 51 c is a stepped surface formed so that the rotating hammer 34 can continue to rotate by rubbing the sliding surface 51 c of the striking rod 51. The size d of the step may be appropriately set according to the tip position of the rotation locus of the rotary hammer 34 and the attachment position of the striking rod 51. The groove portions 51d and 51e are grooves formed from the left-right direction of the striking rod 51 to the inside in the radial direction, and are formed to have a predetermined length in the axial direction. The O-ring holding groove 51f is a circumferentially continuous groove formed to hold an oil seal 46 (see FIG. 4) such as an O-ring. In the vicinity of the connection portion between the striking rod 51 and the striking element 52, a relief groove 51g having a diameter reduced in the circumferential direction is formed. The relief groove 51g is formed to facilitate machining of a lathe or the like, and is not necessarily required, so it may not be formed.

  Next, with reference to FIG. 7, the striking operation on the striking rod 51 by the rotary hammer 34 will be described for each phase. FIG. 7A is a development view of the spindle cam groove 31a and the hammer cam groove 34a, and FIG. 7B is a bottom view of the rotary hammer 34 and the striking rod 51. (3)-(5) is a figure for demonstrating the hit | damage operation | movement to the hitting rod 51 by the rotation hammer 34 for every phase. The upper left diagram in FIG. 7A is a diagram in which the circumferential direction 180 degrees of the spindle cam groove 31a formed on the outer circumferential surface of the spindle 31 is developed on a plane, and the lower right diagram shows the inside of the rotary hammer 34. It is the figure which expand | deployed the part for 180 degree | times of the circumferential direction of the hammer cam groove 34a formed in a surrounding wall on the plane. The spindle cam groove 31a is formed in a V shape having a front end connected thereto. The hammer cam groove 34a is a groove portion (a portion having an increased inner diameter) formed in a substantially pentagonal shape (or a substantially triangular shape) that is opened on the front side and narrowed on the rear side.

  FIG. 7 (2) is a bottom view of the rotary hammer 34 and the striking rod 51. The state (2) indicates a state in which, for example, the striker 52 and the blade holder 70 are not in contact with each other and no external force is applied to the striker 52 of the striker rod 51. In this state, the striking element 52 is positioned at the foremost side by the action of the rod spring 43 (frontmost end position), and even if the projection 35 of the rotary hammer 34 comes close to the striking rod 51, A sufficient gap is formed between the protrusion 35 of the rotary hammer 34 as indicated by an arrow a1. Even if the operator pulls the trigger 8 and rotates the motor 3 in this state, the rotary hammer 34 is idle (non-blowing state).

  FIG. 7 (3) shows a state in which the operator presses the blade 90 against the grass root or the like that cuts the blade 90, that is, a state in which a pressing force as indicated by an arrow 55 a is applied to the striking rod 51 via the blade holder 70. The striking rod 51 moves backward while the rod spring 43 is compressed by the pressing force (external force) as indicated by the arrow 55a. The rearward movement amount is limited by the action of the rod stoppers 44a and 44b and the grooves 51d and 51e shown in FIG. When the rotary hammer 34 rotates in a state where the striking rod 51 has moved to the rearmost position, the projection 35 formed on the rotary hammer 34 collides with the hammer striking surface 51a of the striking rod 51. In the state immediately before the collision (striking state), as shown on the left side of FIG. 7 (3), the spindle 31 and the rotary hammer 34 are caused to have a bottom of the V-shaped valley of each cam groove 31a, 34a by the pressing force of the hammer spring 33 ( The steel ball 32 is engaged via a steel ball 32 located at a position indicated by an arrow b1. When the pressing force 55a to the striking rod 51 is weak in this first collision, the rotating hammer 34 continues to rotate while moving the striking rod 51 in the direction of the arrow 56a by the rotational force of the spindle 31, thereby causing the striking rod 51 to move. The protrusion 35 passes through the rear end portion and continues to rotate. On the other hand, when the striking rod 51 cannot move forward, that is, when the striking force 56a caused by the collision is sufficiently smaller than the pressing force 55a from the outside, the rotary hammer 34 cannot further rotate from the rotational position (3). Thus, the rotation of the rotary hammer 34 stops and only the spindle 31 rotates.

  When the rotation of the rotary hammer 34 stops and only the spindle 31 rotates, the steel ball 32 follows the cam groove 31a (3) from the position of the arrow b1 in the left figure and (4) in the arrow b2 of the left figure. The rotary hammer 34 also moves to the motor 3 side while compressing the hammer spring 33 (moves upward in the figure). (4) shows the state during the retreat. In this state, it can be understood that the rotary hammer 34 is retracted as indicated by an arrow 57a in the state shown in (4) center view as compared with (3) the rotary hammer 34 shown in the center view. Thus, when the rotary hammer 34 retreats and the projection 35 moves further to the motor 3 side than the striking rod 51 as indicated by an arrow a3, the projection 35 gets over the stepped portion of the sliding surface 51c of the striking rod 51. The rotary hammer 34 that has been prevented from rotating can be rapidly rotated taking into account the urging force of the hammer spring 33. The rotation hammer 34 rotates about 180 degrees while moving forward from the state (4) to the state (5) by the start of this rotation.

  In the state of FIG. 7 (5), after the protrusion of the rotary hammer 34 has passed over the sliding surface 51 c (see FIG. 6), the rotary hammer 34 is engaged with the steel ball 32 by the repulsive force of the hammer spring 33. It moves toward the V-shaped valley bottom (position shown by arrow b3) of the spindle cam groove 31a of the spindle 31. The spindle 31 is rotated at a high speed by the repulsive force of the hammer spring 33 in addition to the rotation of the motor 3, and the projection 35 of the rotary hammer 34 is formed on the striking rod 51 as shown by an arrow a4 as shown in the right figure of (5). The rear end surface, that is, the hammer striking surface 51a (see FIG. 6) collides. The direction of the striking force generated by this collision is an arrow 56b, but the rotating hammer 34 collides after a running period of 180 degrees using the force of the hammer spring 33, so that a strong striking force is obtained. be able to. In addition, since the state shown in (5) is the same as (3), the rotating hammer 34 continuously hits the hitting rod 51 a plurality of times by repeating the states shown in (3) to (5). be able to. In this way, a plurality of hits are continuously applied to the blade 90. The reaction force received from the blade 90 on the operator who operates the weaver is affected by the hitting rod 51, the protrusion 35, and the rotary hammer 34. Is transmitted to the hammer spring 33, and the hammer spring 33 is compressed to reduce the reaction force. That is, despite the striking of the striking rod 51 with a large striking force, the reaction force received by the operator is minimal, and an easy-to-use weeding machine with less operator fatigue can be realized.

  Next, the single shape of the blade holder 70 and its holding structure will be described with reference to FIG. FIG. 8 (1) is a top view of a blade holder 70 that holds a blade (blade 90 and blade holder 70) having a tip on the tip side in a reciprocable manner, and (2) is a portion B in FIG. FIG. As shown in FIG. 8A, the blade holder 70 includes two main parts, a sliding part 71 and a mounting part 72, when viewed in the longitudinal direction (front-rear direction or sliding direction). The blade holder 70 is a plate-like member made of a highly rigid metal material, synthetic resin, composite fiber, or the like, and the sliding portion 71 is a portion sandwiched between the upper arm 80 and the lower arm 61. Long holes 70b and 70c for penetrating screws 82 and 85 (see FIG. 1) are formed at two locations of the sliding portion 71. Further, the hit portion 70a is formed on the rear side in the axial direction. The attachment portion 72 is formed with a blade holding portion 70d having a shape suitable for attaching the blade 90. The blade holding portion 70d has an optimum shape in consideration of the lateral width, inclination angle, attachment hole position, etc. of the blade 90 to be attached. Is done. The sliding portion 71 and the mounting portion 72 are preferable in terms of strength if they are integrally formed from the same material, but they can be separated so that various shapes of the mounting portion 72 can be attached to the tip of the sliding portion 71. It may be configured. Further, a mounting angle variable mechanism (not shown) may be provided so that the crossing angle α of the mounting portion 72 is variable.

  FIG. 8B is a partially enlarged view of part B in FIG. The lower arm 61 and the upper arm 80 are fixed by a screw 85 and a nut 86 via a cylindrical distance piece 87. The distance piece 87 and the long hole 70c have a sufficient clearance in the longitudinal direction (front-rear direction), and the positional relationship is such that a clearance δ is secured between the blade holder 70 and the upper arm 80 and the lower arm 61. Become. Actually, the axial direction of the distance piece 87 is the plate thickness (vertical distance) + 2δ of the blade holder 70, and it is determined whether there is a gap on the upper side or a gap on the lower side according to the attitude of the weeding machine. The equally spaced gaps are not always equal. The length in the longitudinal direction (front-rear direction) of the long hole 70 c limits the distance that the blade holder 70 can move in the longitudinal direction, but the range distance may be slightly longer than the movable stroke of the striking rod 51. It ’s fine.

  FIG. 9 (1) is a diagram showing the detailed shape of the blade 90 of FIG. The blade 90 has a mounting surface 90 c formed on the rear side of the stepped portion 90 d and is fixed to the blade holding portion 70 d of the blade holder 70 by screws 76 and 78 and nuts 77 and 79. In this fixing, a wing nut may be used instead of the nuts 77 and 79 so that the blade can be attached and detached without using a tool, or the blade 90 can be easily attached to the blade holding portion 70d using a known one-touch attachment / detachment mechanism. It may be possible to install it. The blade 90 has a mounting surface 90c formed on the rear side, and a blade portion 90a formed so that the thickness gradually decreases on the front side of the stepped portion 90d. The blade edge 90b, which is the tip of the blade portion 90a, is fixed by the blade holding portion 70d of the blade holder 70 so as to be at an oblique angle ζ of the blade center line (lateral center line) with respect to the striking direction of the striking rod 51. . Thus, since the blade 90 is attached by the blade holder 70 so as to have an oblique angle with respect to the weeding direction, an operation of pulling the blade edge of the blade horizontally with respect to the root of the weed is added, and the blade edge angle ξ is further reduced and increased. Can break roots with destructive power. An imaginary line connecting the tips of the cutting edge 90b (line connecting the cutting edges) is in a positional relationship such that an intersecting angle (cutting edge angle ξ) with respect to the blade holder center line, and a contour connecting the tip portions (cutting edges) of the cutting edge 90b. The positional relationship is such that the line (virtual line) 95 is inclined with respect to the striking direction 96. The crossing angle (cutting edge angle ξ) between the line connecting the cutting edges and the longitudinal direction of the blade holder 70 (horizontal direction center line) may be adjustable and fixed at an arbitrary angle. This crossing angle is preferably less than 90 degrees, particularly preferably about 60 to 90 degrees. In the example of FIG. 9 (1), the blade edge 90b is a so-called wave-shaped blade formed in a wave shape, and the thickness decreases from one side to the other side in the thickness direction of the blade 90 as shown in the cross section of (2). It is attached to the tip of the part by cutting with a different slope from the others. The wavy blade has an effect that the trouble of removing the root is reduced because the root is not easily entangled with the blade edge. In addition, when the blade 90 cuts the weed root at the skew angle ζ, the blade edge is wavy, so that the root of the weed is not easy to escape. Since the movement of pulling the blade 90 in the lateral direction is added, the cutting performance is good and the root cutting can be performed efficiently.

  FIG. 9 (3) is a view showing a blade edge of a blade having a shape different from that of (1), in which the blade edge 93b formed at the tip of the blade portion 93a is a serrated blade. The serrated blade has a great ability to catch roots, so it is easy to cut hard roots. Also in this form, the imaginary line 94 that connects the tips of the saw-toothed cutting edge 93b is linear (straight) here. This blade edge 93b is V-shaped when viewed from above, and the angle of the blade attachment is as shown in the EE cross-sectional view of (4). It will be understood that the inclination of the cutting edge in the thickness direction is tighter than the inclination of FIG. 9 (2).

Next, the relationship between the shape of the blade and the cutting edge angle β in the thickness direction will be described with reference to FIG. (1) is a cross-sectional view of the blade 191 having a large blade thickness t ₁ and a cutting edge angle β in the thickness direction (the cross-sectional position is the position of the line DD in FIG. 9A). Because of increased blade thickness t ₁ in the blade 191, it can be relatively large secure the length of the blade table 191a, and may be made larger the included angle beta. However, in order to large cutting edge angle β becomes large blade thickness t _1, the result becomes heavy blade thick blade 191 as. In order to prevent this increase in weight, it is possible to sufficiently secure the length of the blade surface 192a by bending only the tip portion using a thin blade 192 as in (2). With such a blade 192, a blade having a blade thickness t ₁ and a cutting edge angle β in the thickness direction can be substantially realized even with a blade thickness t ₂ thinner than (1), and the length of the blade table 192a can be reduced. It is possible to ensure approximately the same length as the blade surface 191a. Note that in the weeding machine of the present invention, it is optional to use the blade in any one of the shapes shown in FIGS. 10 (1) and (2), and blades having various shapes can be used depending on the type of grass to be cut and soil and other factors. Can be used.

  FIG. 11 is a diagram for explaining a weeding operation using a weeding machine. The operator grasps the main body 1 and installs it near the weeds with a smaller angle of penetration of the blade 90 with respect to the ground as shown in (1). Next, the trigger 8 is pulled to drive the motor 3 and then a thrust is applied to the striking rod 51 to press the blade tip of the blade 90 against the ground. When the blade 90 is pushed, the blade holder 70 moves backward and comes into contact with the striking element 52, and the striking force is transmitted to the blade 90 by the rotation of the rotary hammer 34, so that the blade portion 90 a faces downward and the blade 90 dives into the ground. Moving. Next, when the blade 90 has advanced to a desired depth, the operator moves the main body 1 to increase the penetration angle and applies a thrust so that the blade 90 advances substantially parallel to the ground. As a result, since the reaction force of earth and sand becomes upward, the blade 90 can be returned to the ground surface.

FIG. 12 illustrates the relationship between the entry angle and the clearance angle by the blade in the weeding operation of FIG. Here, the case where the blade 192 is used will be described. When clearance angle alpha ₁ of the blade 192 with respect to the ground strikes to reduce the penetration angle theta ₁ with respect to the ground surface such that positive, ground-facing so that the sum of the reaction force of the sand is shown in FIG respect striking direction become. Therefore, by pulling the trigger 8 and hitting it, the advancing direction of the blade tip of the blade 90 automatically turns to the underground direction. On the other hand, as shown in (2), when the blade 191 is struck by increasing the penetration angle θ ₂ with respect to the ground so that the clearance angle α ₂ becomes negative with respect to the ground, the reaction force of the earth and sand with respect to the striking direction is reduced. The total is for the ground. In this way, the blade tip traveling direction can be made parallel to the ground or facing the ground by increasing the penetration angle θ, and by pulling the trigger 8 and hitting, the blade tip of the blade 90 is earth and sand relative to the hitting direction. The total reaction force becomes ground-oriented. Since the blade 90 has a structure in which the clearance angle of the cutting edge with respect to the weeding direction becomes negative when the penetration angle θ ₂ with respect to the ground is large, even if earth and sand flows into the reciprocating portion, the reciprocation is inhibited by the gap. Can be minimized. When the worker strikes with the clearance angle α being positive with respect to the ground at the initial stage of root cutting and then increasing the penetration angle θ ₂ with respect to the ground, the total reaction force of earth and sand with respect to the striking direction is equal to the ground. Because it faces upward, the cutting edge can be returned to the ground.

  As described above, according to the present embodiment, in the motorized weeding machine, the main body portion 1 having the striking mechanism is provided with the blade holding portion 60 suitable for the striking drive, and the root of the weed is cut by striking the blade. Therefore, the reaction force of the ground when the blade is pushed into the ground and the reaction force when cutting the root of the weed can be reduced. In addition, since there is no scattering of pebbles, soil and weeds, weeding after root cutting is easy. In addition, since the blade is attached to the blade holder at an oblique angle with respect to the weeding direction, the blade edge of the blade is pulled sideways with respect to the root of the weed, and the edge angle is further reduced to cut the root with a large destructive force. it can. Furthermore, since unnecessary hitting in a so-called no-load state where the blade is not pushed from the outside can be eliminated, noise can be reduced and the life of the reciprocating part can be extended. Furthermore, when the blade has a large penetration angle with respect to the ground, the blade has a negative clearance angle with respect to the weeding direction, so the reaction force when pushing the earth and sand away by striking can be directed toward the ground surface. It is possible to advance the blade parallel to the ground or in the direction of the ground surface.

  Next, second and third embodiments of the present invention will be described with reference to FIGS. Here, the same reference numerals are assigned to the same components as those in the first embodiment, and repeated description is omitted. FIG. 13 is a side view of a weeding machine 100 according to a second embodiment of the invention, and a part thereof is shown in a cross-sectional view. In the second embodiment, the shape of the grip portion 2b and the battery mounting portion 2c of the first embodiment is changed, the handle formed with the grip portion gripped by the operator, and the main body portion in which the motor is accommodated are the long handle portion. It was arranged at a position away via. That is, the handle 120 is provided on one end side of the long handle portion (long handle 140), and the main body portion 101 having the impact transmitting portion, the blade holding portion, and the motor is provided on the other end side of the long handle portion. As described above, the handle 120 is provided at a position away from the main body 101 by the long handle 140, so that the operator can work in an easy posture while holding the handle 120. In addition, the battery 10 is mounted not on the vicinity of the main body 101 but on the handle 120 that is separated from the main body. The main body 101 is different from the first embodiment only in the shape of the housing 102, and other parts are the same as those in the first embodiment. The housing 102 includes a body portion 102a and a long handle fixing portion 102b, and a long handle 140 made of a hollow pipe is fixed to the long handle fixing portion 102b by two screws 141. A wiring 155 described later is inserted into the long handle 140. Here, an aluminum hollow pipe is used as the long handle 140 in terms of weight reduction, strength, and wiring. However, the long pipe 140 is not necessarily limited to a hollow pipe, and may be a solid rod-like member. Further, the material may not be made of aluminum but may be realized by using other metal or non-metal materials such as synthetic resin or carbon fiber. The axial direction of the long handle 140 and the direction in which the blade holder 70 reciprocates intersect each other, and the tip end side of the blade holder 70 is positioned about 30 degrees above the axial direction of the long handle 140. Thereby, the blade 90 does not become difficult to visually recognize by the main body 101, and the weeding work can be easily performed while standing. The intersection angle can be set as appropriate, but is preferably 90 degrees or less.

  The housing 122 of the handle 120 has a substantially D-shape when viewed from the side, and is fixed to the long handle 140 by two screws 142. A grip portion 122b for an operator to hold with one hand is provided in a part of the housing 122, and the battery 10 is attached to the lower side of the rear end. The battery 10 can be easily removed from the handle 120 by moving it backward while pressing the release button 10a. A trigger 108 constituting a switch is provided on the front side of the grip portion 122b, and an operator can control the operation of the main body 101 from the handle 120 side. The housing 122 is made of, for example, two molded parts made of synthetic resin and can be divided in the left-right direction. The control circuit board 109 is accommodated inside the housing 122 near the upper part of the battery 10, and a switch circuit is located above the trigger 108. A substrate 107 is mounted. A signal line from the control circuit board 109, a power line from the switch circuit board 107, and the like are transmitted to the main body 101 via a wiring 155 that passes through the internal space of the long handle 140. Near the center of the long handle 140 in the longitudinal direction, a loop-like sub handle 145 is provided so as to extend upward with respect to the long handle 140 via an attachment member 146. The operator can work by holding the sub handle 145 with the left hand and holding the grip portion 122b of the handle 120 with the right hand. At this time, if the sub handle 145 is disposed closer to the handle 120 than the center of gravity 148 of the entire weeding machine 100 (the entire tool), the main body 101 is lowered when gripping and transporting only the sub handle 145. Therefore, the transition to work can be performed smoothly and workability is improved.

  FIG. 14 is a top view of the weeding machine 100 according to the second embodiment of the present invention. The configuration on the front side from the main body 101 is the same as that in the first embodiment, including the blade holder 60. From this figure, it can be understood that the shape of the sub handle 145 formed in a loop shape and the sub handle are provided between the handle 120 and the main body portion 101 having the impact transmission portion. The sub handle 145 and the handle 120 are disposed on the axis of the long handle 140. The attachment position in the longitudinal direction (front-rear direction) of the sub handle 145 can be fixed at an arbitrary position by loosening and moving a screw (not shown) of the attachment member 146. 145 can be positioned. According to the second embodiment, since the extension member (long handle 140) extending from the main body portion is provided and the handle 120 is provided at a position away from the main body portion 101, the operator bends when performing the weeding operation. Since the work can be performed in an upright and natural state, fatigue due to long-time work can be greatly reduced. Furthermore, in the second embodiment, the motor 3, the speed reduction mechanism 20, the impact mechanism 30, and the striker mechanism 50 can be configured with the same parts as the main body 1 used in the first embodiment. By changing, the second embodiment can be realized at low cost.

  Next, a first modification of the second embodiment of the present invention will be described with reference to FIG. In the first modification, the shape of the handle is different from that in FIG. The handle 220 is configured by a cylindrical housing 222, one end of which is fixed to the long handle 140 by two screws 142, and a battery mounting portion 222 b is configured on the other end side to hold the battery 10. Near the center of the housing 222 is a grip part 222a for the operator to hold, and a trigger 208 is provided in the vicinity of the grip part 222a where the fingertip of the index finger hits when the operator holds it. A switch circuit board 207 is accommodated in the vicinity of the trigger 208. A control circuit board 209 is accommodated in the vicinity of the battery 10. In the first modification as well, the housing 222 is divided into left and right parts and is manufactured from a molded product of synthetic resin.

  Next, a second modification of the second embodiment of the present invention will be described with reference to FIG. The difference between the second modification and the second embodiment described with reference to FIG. 13 is that the long handle 140 is fixed so that it can be rotated by a predetermined angle in the direction of the arrow 360 with respect to the main body 301 in a vertical plane. is there. That is, the crossing angle between the axial direction of the long handle 140 and the reciprocating direction of the blade holder 70 can be adjusted and fixed. Therefore, a rotating shaft 351 is provided on the housing 302 of the main body 301, and the fixing member 350 of the long handle 140 is rotatably held. When the housing 302 and the fixing member 350 are rotated, the lock lever 353 is rotated around the fixed shaft 352 in the direction of the arrow 361, and after the fixing position is determined, the lock lever 353 is returned to the position shown in FIG. As a result, the relative position of the housing 302 and the fixing member 350 is fixed. According to the second modification, the main body 301 and the blade holder 60 can be adjusted to an angle that is easy to use with respect to the long handle 140, so that an easy-to-use weeding machine according to the operator and the work situation can be realized.

  Next, a third modification of the second embodiment of the present invention will be described with reference to FIG. A different point from the shape used in the third modified example and FIG. 13 is that the long handle portion is made to be extendable and contractible. As the long handle portion, a large-diameter pipe 241 and a small-diameter pipe 242 are fixed at the joint portion 450. The inner diameter of the large diameter pipe 241 is configured to be slightly larger than the outer diameter of the small diameter pipe 242. A handle 120 is connected to the rear end side of the large diameter pipe 241 by two screws 142, and a sub handle 145 is attached to the front side of the large diameter pipe 241 via an attachment member 146. The joint portion 450 is fixed at an arbitrary position after the small diameter pipe 242 is expanded and contracted in the direction of the arrow 454 of the large diameter pipe 241 by rotating the lock lever 452 around the fixed shaft 451 in the direction of the arrow 453. Configured to be possible. The joint portion 450 can be manufactured by a plastic molded product. Inside the large-diameter pipe 241 and the small-diameter pipe 242, a power line or the like from the switch circuit board 107 is wired. However, since the distance between the main body 101 and the handle 120 changes, part or all of the wiring is curled. 447 is preferable. The curl line 447 is preferably configured to include both a power line for supplying driving power to the motor 3 and a control signal line for transmitting a control signal to the inverter circuit board 6. According to this modification, the overall length of the long handle can be adjusted in accordance with the height of the worker, etc., so that an easy-to-use weeding machine can be realized. In addition, since the long handle can be expanded and contracted, it is possible to save space for transportation and storage by reducing the length during transportation and storage.

  Next, a third embodiment of the present invention will be described with reference to FIG. Although the third embodiment has a shape similar to that of the second embodiment, the battery 10 shown in FIG. 13 is mounted not on the handle 120 but on the main body 501 side. The configuration of the main part in the main body 501 is not changed from that of the first embodiment, but the shape of the housing 502 is changed in order to mount the battery 10. The housing 502 is formed with a body portion 502 a, an attachment portion 502 b for attaching the long handle 140, and a battery attachment portion 502 c for attaching the battery 10. A control circuit board 509 is accommodated inside the housing 502 and in the vicinity of the battery 10.

  In the third embodiment, since the battery 10 is not attached to the handle side, the housing 522 of the handle 520 is simply provided with a grip 522b and a trigger 508. The handle 520 is constituted by a split housing 522 made of synthetic resin, and a switch circuit board 507 is accommodated in the housing 522. According to the third embodiment, since the battery 10 is mounted on the main body 501, the position of the center of gravity is on the front side and the lower side, so that the work performed while pressing the blade 90 against the ground is very easy to perform.

  Next, a fourth embodiment of the present invention will be described with reference to FIGS. In the weeding machine 600 according to the fourth embodiment, the speed reduction mechanism and the impact mechanism are realized differently from the main body of the first to third embodiments. However, the principle that a striking force is applied to the blade 90 via the blade holder 70 by striking the striking rod a plurality of times is the same as in the first embodiment.

  20 is a partial cross-sectional view of the vicinity of the striking mechanism of FIG. The motor 603 is a DC motor with a brush and is accommodated in the body 602 a of the housing 602. A pinion gear 621 is attached to the rotation shaft 603 a of the motor 603, and the pinion gear 621 meshes with the first gear 622 that is supported by the first rotation shaft 623. A gear 624 is formed coaxially on the lower portion of the first gear 622, and the gear 624 meshes with the second gear 625. The second gear 625 is pivotally supported on the second rotating shaft 627 together with the eccentric cam 628. As described above, by using a speed reduction mechanism using a plurality of gears, the rotation of the motor 603 is decelerated at a predetermined reduction ratio, and the eccentric cam 628 is rotated. The second gear 625 and the eccentric cam 628 are fixed by two power transmission pins 626 so that they rotate synchronously about the second rotation shaft 627. Since the connecting rod 653 connected to the striking rod 651 abuts on the front side of the eccentric cam 628, the rotational motion of the eccentric cam 628 is converted into the movement of the striking rod 651 in the axial direction (front-rear direction). The striking rod 651 and the connecting rod 653 are fixed. When the connecting rod 653 moves back and forth, the striking rod 651 moves forward, so that the striking element 652 provided in front of the striking rod 651 strikes the blade holder 70. can do. The lower end of the second rotating shaft 627 is fixed by a fixed plate 629, and the lower side of the speed reduction mechanism is covered by a gear cover 633.

  The hammer case 641 is a member that holds the striking rod 651 so as to be able to reciprocate, and also fixes the blade holder 60 by fixing the lower arm 61. A through hole 641b is formed inside the hammer case 641, and the striking rod 651 is held in a reciprocating manner through a bearing 642 made of metal or the like. The hammer case 641 is preferably manufactured from a molded product of aluminum or iron metal from the viewpoint of strength. An elongated hole 650e is provided at a midpoint in the axial direction (corresponding to the front-rear direction here) of the striking rod 651 in a side view so as to prevent the striking rod 651 from falling off while allowing the striking rod 651 to reciprocate. A load stopper 644 is provided from the left and right outside of the case 641. The tip of the load stopper 644 is positioned inside the elongated hole 650e. The shape of the portion accommodated in the striking element 652 and the bearing 642 of the striking rod 651 is substantially the same as that of the striking rod 51 described in the first embodiment, and the operation thereof is also the same.

  A blade holder 70 is held on the front side of the striking rod 651 so as to be movable in the front-rear direction as indicated by an arrow 666. The lower arm 61 is screwed to the hammer case 641 by a plurality of screws 62 and 64, and the blade holder 60 including the lower arm 61 and the upper arm 80 is the same as the parts used in the first embodiment. Things can be used. When the trigger 108 is pulled and the motor 603 is activated, the rotational force is reduced by the reduction mechanism (621 to 625) and transmitted to the eccentric cam 628 arranged coaxially with the second gear 625. The second gear 625 and the eccentric cam 628 are connected by the two power transmission pins 626 and rotate in synchronization with the second rotation shaft 627 as a center. A connecting rod 653 extending from the rear end of the striking rod 651 is disposed in contact with the front side of the eccentric cam 628. Here, the state of engagement between the connecting rod 653 and the eccentric cam 628 will be described with reference to FIG. In FIG. 21, two annular portions 653a and 653b spreading in a semicircular shape are formed at the end (rear end side) of the parallel arm portion of the connecting rod 653. The eccentric cam 628 has a circular outer diameter, but its rotational axis is not at the center position of the circle, but is provided at an eccentric position. Here, as shown in the figure, the second rotation shaft 627 is provided at a position that coincides with the longitudinal center line (axis line) of the striking rod 651 and the connecting rod 653. The inner sides of the two annular portions 653a and 653b are configured to be sufficiently larger than the outer diameter of the eccentric cam 628. As a result, when the eccentric cam 628 rotates about the second rotation shaft 627, the contact position (the position of the arrow c1) between the outer edge of the eccentric cam 628 and the annular portions 653a and 653b reciprocates in the left-right direction, and the connecting rod 653 Is reciprocated in the direction of arrow 667. Here, since the spring 643 is interposed in the striking rod 651 as shown in FIG. 20, the striking rod 651 moves forward when there is no urging force from the blade holder 70. Here, since the striking rod 651 and the connecting rod 653 are formed as an integrated product, when the striking rod 651 is located at the foremost position, the connecting rod 653 is also moved forward, and the striking rod 651 is not in contact with the striking rod 651. . Thus, the reciprocating mechanism of the striking rod 651 can be realized by using the eccentric cam 628 as in this embodiment without using the impact mechanism 30 as in the first to third embodiments. In FIG. 21, the annular portions 653a and 653b are shaped so that only half of the oval annular member is used. However, one round of the oval annular member is formed so that the eccentric cam 628 is placed inside the annular member. It is good also as a form which accommodates.

  When the operator grasps the weeding machine 600 and presses the blade 90 against earth or sand or weeds, the blade 90 is pushed back, so that the blade holder 70 moves backward (in the direction approaching the hitting rod 651) and the hitting rod 651 is also moved. Similarly, it moves rearward, and one of the two annular portions 653 a and 653 b of the connecting rod 653 comes into contact with the eccentric cam 628. When the motor 603 rotates in this state, a force for pushing the striking rod 651 forward is applied, so that a striking force is given forward to the blade holder 70, and the blade 90 can cut off grass roots and the like. It becomes.

  As described above, in the weeding machine 600 according to the fourth embodiment, the mechanism that moves the striking rod 651 forward without using the impact mechanism 30 is realized, so that the efficiency is the same as in the first to third embodiments. Weeding work can be performed well. The mechanism for pushing the striking rod 651 forward is not limited to the configuration shown in the fourth embodiment, and any other power transmission mechanism can be used as long as it is a power conversion mechanism that can convert the rotational motion of the motor into linear motion. You may do it.

Finally, the types of blades used in the weeding machine according to the present invention will be described with reference to FIG. The blade 910 in FIG. 22 (1) is arranged so that a virtual line 915 connecting the tips of the blade edge 911 is a straight line, and basically has a shape close to the blade edge of the blade in FIG. 9 (3). is there. The blade edge 911 has a tapered shape in the thickness direction, as can be seen from the HH sectional view.
The blade 920 of (2) has an arcuate cutting edge as the cutting edge 921, and is arranged so that an imaginary line 925 connecting the tips of the cutting edge portions is a curved line. As can be seen from the II cross-sectional view, the blade edge 921 has a tapered shape in the thickness direction.
The blade 930 of (3) has a cutting edge 931 formed continuously, and the tip line 935 of the cutting edge is curved, but the center of the rotation radius is opposite to the blade 920 of (2). become. As can be seen from the JJ cross-sectional view, the blade edge 931 has a tapered shape in the thickness direction.
The blade 940 in (4) has a V-shaped cutting edge viewed from above, and the tip lines 945 and 946 of the cutting edges 941 and 942 are straight lines, respectively, and have a predetermined angle. Configured to intersect. As can be seen from the KK cross-sectional view, the blade edge 941 has a tapered shape in the thickness direction.
As described above, the cutting edge used in the weeding machine according to the present invention can be used in various shapes, in particular, the tip is tapered in the thickness direction, and the contour line viewed from above the tip is linear ( (Straight line, curved line).

  As mentioned above, although this invention was demonstrated based on the Example, this invention is not limited to the above-mentioned Example, A various change is possible within the range which does not deviate from the meaning. For example, in the above-described embodiment, the description has been made using the example of the impact tool (weeding machine) driven by the battery, but the present invention is not limited to the cordless type tool, and may be an impact tool using a commercial power source. . The example of the blade of the present invention has been described with the blade holder and the blade attached to the tip thereof. However, the blade is not divided, that is, the blade itself is held so as to be able to reciprocate, and the hammer is directly hit by the hit transmission unit. It may be configured.

  In the above-described embodiment, an example in which a striking force is used for a weeding machine that scrapes the roots of weeds has been described. However, a tool for cutting a tree branch with a blade in a similar configuration, a tool for cutting a stem or the like to harvest fruits It can also be used as a tool for removing gums or adhesives bonded to asphalt or floor. Even in this case, as described above, the configuration is such that the striking force is transmitted to the blade only when the blade is moving to the striking transmission portion side, and the main body including the motor / striking transmission portion and It is preferable to have a long handle portion between the handle for gripping the tool.

DESCRIPTION OF SYMBOLS 1 Main-body part 2 Housing 2a Body part 2b Grip part 2c Battery attachment part 3 Motor 3a Rotor 3b Stator 3c Magnet 3d Rotating shaft 6 Inverter circuit board 7 Switch circuit board 8 Trigger 8a Switch 9 Control circuit board 10 Battery 10a Release button 11 Terminal 12 Operation panel 13 Switching element 14 Cooling fan 15 Position detection element 17a, 17b Air intake 18 Bearing 19a, 19b Bearing 20 Reduction mechanism 21 Sun gear 22 Planetary gear 23 Rotating shaft 24 Ring gear 27 Gear case 30 Impact mechanism 31 Spindle 31a Spindle cam groove 31b Tip shaft 32 Steel ball 33 Hammer spring 34 Rotating hammer 34a Hammer cam groove 35 Projection 36 Stopper ring 37 Bearing 39 Buffer material 41 Hammer case 4 a Holding part 41b Through hole 41c Screw hole 42 Bearing 42a Flange part 42b Screw hole 43 Rod spring 44a, 44b Rod stopper 46 Oil seal 47a-47d Screw 50 Strike element mechanism 50e Long hole 51 Strike rod 51a Hammer striking face 51b Relief face 51c Sliding surfaces 51d, 51e Groove 51f Ring retaining groove 52 Impactor 55a Pressing force 56a Impact force 58, 59 Screw 60 Blade holding part 61 Lower arm 62, 64 Screw 70 Blade holder 70a Impacted part 70b, 70c Slotted hole 70d Blade holding Part 71 Sliding part 72 Mounting part 76, 78 Screw 77, 79 Nut 80 Upper arm 82, 85 Screw 83, 86 Nut 84, 87 Distance piece 90 Blade 90a Blade part 90b Cutting edge 90c Mounting surface 90d Step part 91 Blade holder 9 3a Blade portion 93b Blade edge 94 Virtual line 100 Weeding machine 101 Main body portion 102 Housing 102a Body portion 102b Long handle fixing portion 107 Switch circuit board 108 Trigger 109 Control circuit board 120 Handle 122 Housing 122b Grip portion 140 Long handle 141, 142 Screw 145 Sub handle 146 Mounting member 148 Center of gravity position 155 Wiring 191 and 192 Blade 191a and 192a Blade surface 191b and 192b Blade back 200 Weeding machine 202 Housing 202b Long handle fixing part 207 Switch circuit board 208 Trigger 209 Control circuit board 220 Handle 222 Housing 222a Grip part 222b Battery mounting Portion 241 Large diameter pipe 242 Small diameter pipe 300 Weeding machine 301 Main body 302 Housing 350 Fixing member 351 Rotating shaft 352 Fixed shaft 353 Lock lever 360 Arrow 361 Arrow 400 Weeding machine 401 Main body part 447 Curled wire 450 Joining part 451 Fixed shaft 452 Lock lever 500 Weeding machine 501 Main body part 502 Housing 502a Body part 502b Mounting part 502c Battery mounting part 507 Switch circuit board 508 Trigger 509 Control circuit board 520 Handle 522 Housing 522b Grip part 600 Weeding machine 601 Main body part 602 Housing 602a Body part 602b Long handle fixing part 603 Motor 603a Rotating shaft 621 Pinion gear 622 First gear 623 First rotating shaft 624 Gear 625 Second gear 626 Power transmission pin 627 Second rotating shaft 628 Eccentric cam 629 Fixed plate 633 Gear cover 641 Hammer case 641b Through hole 642 Bearing 643 Spring 644 Load stopper 650e slot 651 striking rod 652 striker 653 connecting rods 653a, 653b annular portion 910,920,930,940 blade 911,921,931,941,942 edge 915, 925 virtual line
935, 945 Tip line

Claims (16)

Battery,
A motor that drives the battery as a drive source;
A switch for controlling the driving of the motor;
A handle gripped by the operator,
A long handle interposed between the handle and the motor;
A blade holder for holding the blade so as to be reciprocally movable;
A striking tool having a striking transmission unit that applies a rotational force of the motor as a striking force to the blade.   The striking tool according to claim 1, wherein the handle is provided on one end side of the long handle portion, and the hit transmission portion and the blade holding portion are provided on the other end side of the long handle portion.   The impact tool according to claim 2, wherein the switch and the battery are provided on the handle.   The impact tool according to claim 2, wherein the motor is provided on the other end side of the long handle portion.   The tip of the cutter has a linear shape, and the cutter holding portion holds the cutter in a non-rotatable state in a state where the linear shape of the cutter extends so as to be orthogonal to the axial direction of the long handle portion. The impact tool according to any one of claims 1 to 4.   The striking tool according to any one of claims 1 to 5, wherein the reciprocating direction of the cutter and the axial direction of the long handle portion intersect each other.   The striking tool according to claim 6, wherein an intersection angle between the reciprocating direction of the blade and the axial direction of the long handle is 90 degrees or less.   The striking tool according to claim 7, wherein an intersecting angle between the reciprocating direction of the blade and the axial direction of the long handle portion can be adjusted and fixed.   The striking tool according to any one of claims 2 to 8, wherein a sub handle is provided between the handle and the striking transmission portion and on the long handle portion. The impact tool according to claim 9, wherein the sub handle and the handle are disposed on an axis of the long handle portion.
  The impact tool according to claim 9 or 10, wherein the sub handle is disposed closer to the handle than the center of gravity of the entire tool.   The striking tool according to any one of claims 9 to 11, wherein the sub handle is fixable at an arbitrary position of the long handle portion.   The striking tool according to claim 1, wherein the long handle part is extendable and contractible.   An urging means for urging the blade toward the tip side is provided, and the hammer transmission unit transmits the hammering force to the blade in a state where the blade is retracted against the urging force of the biasing means. The striking tool according to claim 1, wherein the striking tool is characterized in that   15. The hammer transmission portion according to claim 1, further comprising a hammer portion having a rotation axis that rotates by receiving a rotational force of the motor through elastic means and intersects a reciprocating direction of the blade. The striking tool according to any one of claims.   The impact tool according to any one of claims 1 to 15, wherein the blade holding part is detachable with no tool.

Images