JP4167944B2 - Portable power brush cutter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a portable power brush cutter that is used for cutting grasses such as weeds that grow on the ground surface from the vicinity of the root.
[0002]
[Prior art]
This type of portable power brush cutter has a rotating work body at the tip of the operation tube, transmits the rotation output of the power source to the rotating work body through a transmission shaft inserted in the operation tube, and rotates it. It is configured as follows. As the power source, for example, a small gasoline engine is adopted, and generally connected to the base end portion of the operation pipe. The operation tube may be equipped with a grip handle.
[0003]
As the rotary working body, for example, a rotary blade in which a blade such as a saw blade is provided on the outer periphery of a metal disk is employed. For example, as shown in Patent Document 1, normally, the rotation axis of the rotary blade intersects with the axis of the operation tube. This is for the purpose of making the rotary blade as parallel as possible to the ground surface to be trimmed during the work.
[0004]
The mowing operation is performed by the operator holding the machine body swinging the operation tube and moving the rotary blade along the ground surface.
[0005]
By the way, the ground surface to be trimmed is not always flat, and may have a toe-up or toe-down slope. In such a case, if the crossing angle of the rotary shaft of the rotary blade with respect to the axis of the control tube is fixed, the base end of the control tube is lifted high or low in order to make the rotary blade parallel to the ground surface. It is necessary to move the position, and the work becomes very difficult. Also, even when cutting the ground surface, a worker with a tall height keeps the base end of the control tube low, while a worker without a height has a high base end of the control tube. It must be lifted, making it difficult to work. When the engine is directly connected to the base end of the operation pipe, the weight of the engine is high, so that the difficulty of the operation as described above becomes even more so.
[0006]
Therefore, conventionally, as shown in, for example, Patent Document 2, the angle of the rotary shaft of the rotary blade with respect to the axis of the operation tube can be adjusted, depending on the inclination of the target ground surface or the operator Depending on the height, there is one in which the rotary blade can be made to take a posture parallel to the ground surface while the base end portion of the operation tube is held at an easy height for the operator.
[0007]
[Patent Document 1]
JP 63-56214 A [Patent Document 2]
Japanese Utility Model Publication No. 3-17619 [0008]
[Problems to be solved by the invention]
In the configuration shown in Patent Document 2, a support rod extending obliquely downward is provided at the tip of the operation tube, and a rotary blade is attached to the support rod so as to be able to swing back and forth. An angle of the rotary blade can be adjusted by using a shaft inserted through a flexible transmission shaft and moving the operation tube and the transmission shaft relative to each other by operating means.
[0009]
However, in the above configuration, since a relatively heavy rotary blade is supported at a position far away from the tip of the operation tube, the influence of inertia force is exerted when the operation tube is swung in the left-right direction. As a result, the operation tube rotates and there is a problem that the rotary blade swings left and right. That is, when the swing operation of the operation tube is performed, the rotary blade swings in an unstable manner, which leads to deterioration in workability.
[0010]
In the above configuration, since the dimension from the tip of the operation tube to the rotary blade is relatively large, it is very difficult to perform the brushing operation in a situation where an obstacle exists at a position away from the ground surface. There is also a problem of becoming.
[0011]
In addition, since the weight of the tip of the operation tube is increased, there is a problem that the swinging operation is difficult.
[0012]
Furthermore, the power transmission from the operation tube to the rotary blade employs a configuration in which a flexible transmission shaft is inserted into the flexible tube. Such a flexible tube is a member that inserts and holds a transmission shaft that rotates at a high speed, and is also a member that needs to withstand a predetermined pulling force and compression force. Is relatively large. Therefore, in the above configuration, the angle of the rotary blade is changed by forcibly bending and deforming the dual configuration of the flexible tube having such a large bending resistance and the transmission shaft. In order to change the angle of the blade, an operating force that resists the large bending resistance described above is required. Thus, in the portable brush cutter having the above-described configuration described in Patent Document 2, it cannot be said that the angle of the rotary blade can be changed easily.
[0013]
The present invention has been conceived under the circumstances described above, and the angle and orientation of the rotary blade with respect to the axis of the operation tube can be made more lightly and without increasing the weight or size of the tip of the operation tube. The challenge is to make it easy to change.
[0014]
DISCLOSURE OF THE INVENTION
In order to solve the above problems, the present invention employs the following technical means.
[0015]
That is, the portable power brush cutter provided by the present invention is supported via the operation tube, the transmission shaft inserted through the operation tube, and the rotary blade support member provided at the tip of the operation tube. and a rotary blade, the rotational output of the power source via the transmission shaft is transmitted to the rotating blade, with which the rotary blade is configured to rotate, the rotary blade supporting member, of the transmission shaft An input shaft to which the tip is connected, and a rotary blade mounting shaft that is linked to the input shaft via a bevel gear mechanism, and at the tip of the operation tube, about a lateral axis that is substantially orthogonal to the axis of the operation tube. The portable power brush cutter is supported by the operation tube so as to be rotatable, and the transmission shaft is flexible at least in a region from the tip of the operation tube to the rotary blade support member. On the other hand, the operation tube A first connecting member is provided at the end, and a second connecting member is provided on the rotary blade support member. The first connecting member and the second connecting member are connected to the lateral axis. The transmission shaft is inserted through the connection first member and the connection second member in a penetrating manner, and the vertical width generally increases as the horizontal axis is approached. And the rotation blade support member is rotated around the horizontal axis by rotating the operation lever provided on the proximal end side of the operation tube. And a braking means capable of selecting a state in which the rotation can be performed almost freely and a state in which the rotation is prevented by the braking force.
[0016]
In the portable power brush cutter having the above-described configuration, the rotary blade support member is supported so as to be rotatable about a lateral axis substantially orthogonal to the axis of the operation tube with respect to the operation tube. Therefore, when the rotary blade support member is rotated with respect to the operation tube, the rotation and resistance of the rotary blade support member with respect to the operation tube can be made relatively small because compression and tension on the transmission shaft do not act greatly. Therefore, in a state where the braking by the braking means is released, the rotary blade support member can rotate with a relatively low resistance. In actual use, by applying an appropriate position of the rotary blade to the ground, etc., by determining the angular orientation of the rotary blade with respect to the operation tube as desired, the brake means is operated as described above. The determined angular attitude of the rotary blade is maintained. Thus, the portable power brush cutter having the above-described configuration can change the angular posture of the rotary blade lightly and easily.
[0017]
The transmission shaft is more preferably in a bare state. As a result, the transmission shaft is less likely to act as a rotation resistance of the rotary blade support member, and therefore the rotation of the rotary blade support member relative to the operation tube can be performed with a lower resistance.
[0020]
According to the above configuration, the connecting first member and the connecting second member can be suitably rotated with each other, and the transmission shaft is inserted between the connecting first member and the connecting second member in a bare state. It will be convenient to do.
[0022]
Further according to the above configuration, the transmission shaft insertion holes formed in the first connecting member and the second connecting member are tapered so that the vertical width generally increases as they approach the lateral axis . When the coupling second member is rotated with respect to the coupling first member, the transmission shaft is gently curved, and it is convenient for the transmission shaft to inadvertently contact the inner wall of the transmission shaft insertion hole. Can be avoided well. As a result, it is possible to further prevent the transmission shaft from resisting and inhibiting the rotation of the connection second member with respect to the connection first member, and it is possible to conveniently avoid damage to the transmission shaft.
[0023]
In a preferred embodiment, one of the first connecting member and the second connecting member is formed with a pair of first connecting walls facing each other with the transmission shaft interposed therebetween, and the first connecting member. A pair of second connection walls that are in contact with the outer surfaces of the pair of first connection walls are formed on the other of the connection second members, and each of the first connection walls and the second connection located between the transmission shafts. The walls are connected to each other by screw members that are connected in the thickness direction and that correspond to the lateral axis.
[0024]
By comprising in this way, a connection 2nd member can be connected with a connection 1st member so that mutual rotation is possible with a simpler structure as mentioned above.
[0025]
In a preferred embodiment, the braking means includes a winding drum portion having the same axial center as the transverse axis on the second connecting member, while connecting an appropriate portion to the first connecting member, and the winding drum. The end of the band member wound around the part is displaced by the operating means.
[0026]
The braking means according to this configuration is in the form of a so-called band brake. Since the band brake has a large contact area between the band member and the winding drum portion during a braking operation, a large braking force can be generated with a small operating force. As a result, since the rotary blade rotates at a high speed during operation, a relatively large vibration is generated in the entire apparatus. Regardless of such vibration, the connected second member or the rotary blade support member is brought into the adjusted angular posture. It can be held stably and safety is ensured.
[0027]
Also in the preferred embodiment, one end of the cable is connected to the proper portion of the upper Kimisao operation lever, the other end of this cable is connected to the end of the band member in one direction the control lever When the rotation operation is performed, the band member tightens the winding body portion by the displacement of the end portion of the band member via the cable.
[0028]
Since the braking means is in the form of a band brake as described above, a large braking force can be obtained even with a small operating force. Therefore, even if a cable is used as the member for transmitting the operation force, the operation by the relatively small operation lever can be effectively transmitted to the band brake, and reliable braking can be performed.
[0029]
In a preferred embodiment, the operation lever further includes a latch mechanism that prevents return rotation when the control lever is rotated by a predetermined amount in one direction, and a release mechanism that releases the latch mechanism.
[0030]
With this configuration, when adopting an operating force transmission structure between the operating lever and the band brake via a cable capable of transmitting only the pulling force, it is possible to conveniently hold and release the braking force on the operating lever side. it can.
[0032]
Further, in the above arrangement, the operation lever, for example, by kick set in the vicinity of the operation grip normally provided in operating tube, without significantly changing the working position of the mowing, the angle of the rotary blade conveniently described above A posture changing operation can be performed.
[0033]
Other features and advantages of the present invention will become more apparent from the detailed description given below with reference to the drawings.
[0034]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a preferred embodiment of the present invention will be specifically described with reference to the drawings.
[0035]
1 to 8 show a portable power brush cutter 1 according to an embodiment of the present invention. As shown in FIG. 1, the brush cutter 1 includes an operation tube 10, a small engine 20 connected to the proximal end of the operation tube 10, and a rotary blade 31 supported by a distal end portion of the operation tube 10. The rotational output of the small engine 20 is transmitted to the rotary blade 31 via the transmission shaft 40 inserted into the operation tube 10.
[0036]
The operation tube 10 is formed of a lightweight metal pipe such as aluminum, and a clutch housing 11 is integrally attached to a base end portion thereof as shown in FIG. The clutch housing 11 is connected to the main body of the engine 20, whereby the base end portion of the operation tube 10 is connected to the engine 20. A clutch drum 12 is rotatably supported inside the clutch housing 11, and a base end of a transmission shaft 40 is connected to the shaft 13 of the clutch drum 12. The clutch drum 12 forms a centrifugal clutch in cooperation with a clutch shoe (not shown) on the engine side. When the rotational speed of the engine 20 is increased by operating a throttle lever (not shown), the centrifugal clutch transmits the rotational output of the engine 20 to the clutch drum 12 and rotates the transmission shaft 40.
[0037]
A rotary blade support member 30 is provided at the distal end of the operation tube 10. As shown in FIG. 3, the rotary blade support member 30 is linked to the input shaft 32 to which the distal end portion of the transmission shaft 40 is coupled, and the input shaft 32 via a bevel gear mechanism. The rotary blade mounting shaft 33 is provided in a housing 35. That is, the input shaft 32 includes a first bevel gear 34 at the tip thereof and is rotatably supported through a bearing 36 in the proximal end side cylindrical portion 35A of the housing 35, while the rotary blade mounting shaft 33 includes a second bevel gear 37 that meshes with the first bevel gear 34 on the base end side thereof, and is rotatably supported via a bearing 38 in the distal end side cylindrical portion 35 </ b> B of the housing 35. That is, in the rotary blade support member 30, the direction of the rotational power transmission shaft is changed so that the input shaft 32 and the rotary blade mounting shaft 33 intersect at an angle of about 120 degrees. A rotary blade 31 is attached to the tip of the rotary blade attachment shaft 33. As the rotary blade 31, for example, a blade in which a saw blade is directly formed on the outer periphery of a metal disk or a blade having a super steel tip blade attached thereto is suitably used.
[0038]
A grip handle 17 extending in the lateral direction is attached to the proximal end of the operation tube 10 via a suitable bracket 18. In addition, a throttle lever (not shown) for controlling the rotational speed of the engine 20 is attached to an appropriate position of the operation tube 10.
[0039]
The rotary blade support member 30 is coupled to the distal end portion of the operation tube 10 so as to be rotatable around the lateral axis 14. In the present invention, the lateral axis 14 is set substantially perpendicular to the axis of the operation tube 10. In other words, the lateral axis 14 intersects the axis of the operation tube 10 or is not so far away from the axis of the operation tube 10 in the vertical direction.
[0040]
More specifically, the connection first member 6 is integrally attached to the distal end portion of the operation tube 10, while the connection second member 7 is connected to the proximal end side cylindrical portion 35 </ b> A of the housing 35 of the rotary blade support member 30. The connecting first member 6 and the connecting second member 7 are connected to each other so as to be rotatable around the lateral axis 14.
[0041]
As shown in FIGS. 3 to 7, the connecting first member 6 has a cylindrical portion 61 fitted into the operation tube 10, and extends to the distal end side of the cylindrical portion 61, and has a substantially circular shape in side view. The left and right paired first connection walls 62, 62 and a mantle portion 63 fitted on the operation tube are provided. The pair of first connection walls 62, 62 are opposed to each other with a sufficient interval between the transmission shafts 40 disposed therebetween. The upper and lower portions of the pair of first connection walls 62, 62 are connected to each other by a bridge portion 64 connected to the outer cover portion 63. Therefore, the interval between the pair of first connection walls 62, 62 is inadvertent. It will not be reduced. A conductive shaft insertion hole 61 a is formed through the cylindrical portion 61 of the connection first member 6 in the axial direction, and the vertical width of the conductive shaft insertion hole 61 a increases toward the distal end side of the cylindrical portion 61. The taper is enlarged. A stopper portion 63 a for defining a rotation range of the second connecting member 7 around the lateral axis 14 is formed at the distal end of the outer cover 63 so as to come into contact with an appropriate portion of the second connecting member 7 to be described later. ing.
[0042]
As shown in FIGS. 3 to 8, the connecting second member 7 has a cylindrical portion 71 fitted into the proximal end side cylindrical portion 35 </ b> A of the rotary blade support member 30. A pair of left and right second connection walls 72, 72 that are in contact with the outer surfaces of the pair of first connection walls 62, 62 of the connection first member 6 and have a substantially circular shape in a side view are formed on the end-side extending portion 71 b. ing. The extending portion 71b also extends along the outer periphery of the pair of second connecting walls 72, 72, and cooperates with the stopper portion 63a of the connecting first member 6 to rotate the connecting second member 7. The stopper portion 73a and the pair of second connecting walls 72, 72 are separated from each other. A transmission shaft insertion hole 71a is formed in the cylindrical portion 71 through the extension portion 71b of the second connecting member 7 so as to penetrate in the axial direction. The taper shape expands toward the member 6 side.
[0043]
As clearly shown in FIGS. 5 to 7, the connecting first member 6 and the connecting second member 7 are respectively connected to the first connecting walls 62 and 62 and the second connecting wall on both sides of the transmission shaft 40. By fastening the screws 72 and 72 with the screw members 8 extending in the thickness direction, the screw members 8 corresponding to the lateral shaft 14 are connected to each other so as to be rotatable relative to each other. More specifically, a screw hole 62a is formed in each first connection wall 62, 62, and a hole 72a having a diameter larger than that of the screw hole 62a is formed in each second connection wall 72, 72. On the other hand, the screw member 8 includes a shaft portion 8a fitted into the hole 72a, a male screw portion 8b formed on the distal end side of the shaft portion 8a, and a head formed on the proximal end side of the shaft portion 8a. The male screw portion 8b is screwed into the screw hole 62a until the tip of the cylindrical portion 71 comes into contact with the outer surfaces of the first connecting walls 62, 62. Thereby, the connection 2nd member 7 becomes rotatable with respect to the connection 1st member 6 centering on the axial center of each screw member 8, ie, the said horizontal direction axis | shaft 14, and.
[0044]
The transmission shaft 40 is at least a portion extending from the distal end portion of the operation tube 10 to the proximal end side cylindrical portion 35A of the rotary blade support member 30, in other words, the transmission shaft insertion of the connection first member 6 and the connection second member 7. The hole 61a, 71a or the portion that passes between the pair of first connection walls 62, 62 of the connection first member 6 needs to have flexibility. In the embodiment shown in the figure, the transmission shaft 40 can employ a so-called flexible shaft member. This flexible shaft has, for example, a structure in which fine metal wires are wound densely and in multiple layers around a thin metal core, and can bend relatively freely while effectively transmitting rotational torque. It is something that can be done.
[0045]
In the embodiment shown in the figure, inside the operation tube 10, the flexible transmission shaft 40 is arranged in a manner inserted through a holding tube 50 formed of resin, for example. The tube 50 rotates stably without causing a shake. The holding tube 50 has a proximal end side substantially fixed to the inner wall of the proximal end portion of the operation tube 10, and a distal end portion fixed to the proximal end side of the cylindrical portion 61 of the connection first member 6. ing. Therefore, the flexible transmission shaft 40 is in a bare state at a portion where the transmission shaft insertion holes 61a and 71a of the connection first member 6 and the connection second member 7 are inserted.
[0046]
Note that, as described above, the transmission shaft 40 has a base end connected to the shaft 13 of the clutch drum 12 and a tip connected to the input shaft 32 of the rotary blade support member 30, respectively. It means that it is connected so that force is transmitted. Therefore, for example, the end portion of the transmission shaft 40 is formed into a square shaft shape or a spline shape, and the shaft shaft 13 of the clutch drum 12 or the input shaft 32 is provided on the end surface of the square shaft or spline shape. It is preferable to form a square hole or a spline hole for receiving the end of the transmission shaft 40 so that the transmission shaft 40 can be slightly idled in the axial direction.
[0047]
Now, in the portable power brush cutter 1 according to the present invention, the rotary blade support member 30 can rotate freely about the lateral axis 14 and the rotation is prevented by the braking force. The braking means 9 that can be selected is provided, and in the embodiment shown in the figure, this is configured as follows.
[0048]
As shown in FIGS. 5 to 8, among the pair of second connection walls 72 of the connection second member 7, the thickness of the second connection wall 72 on the right side is increased and the outer peripheral surface of the second connection wall 72 is increased. Is used as a winding drum portion 74 for a band brake, while a band member 91 having one end connected to an appropriate portion of the connecting first member 6 is wound around the winding drum portion 74, and the other end of the band member 91 is It is made to displace by operation via the cable 93. That is, in the embodiment shown in the figure, the braking means 9 is in the form of a band brake that can be operated via the cable 93. This will be described in detail below.
[0049]
A bulging portion 65 extending rightward and upward with respect to the operation tube 10 is provided on the outer cover portion 63 of the connecting first member 6, and on the front surface of the bulging portion 65, the winding drum portion is provided. A band support surface 66 having a substantially semicylindrical inner surface facing the rear side surface of the outer periphery of 74 is formed. The band member 91 is a metal member having a predetermined width, and has a form in which the abutting end portions 91A and 91B are erected so as to face each other at both ends thereof. Reinforcing ribs 92 for maintaining the standing state with respect to the band middle part are formed on both side edges of the front end 91A. As shown in FIG. 8, the band support surface 66 is formed in a form that can be supported so as to cover the rear half of the band member 91 and one abutting end 91 </ b> B connected to the upper part thereof. The band member 91 is fixed to the band support surface 66 by screwing a screw 91d passed through the through hole 91c formed in the band member 91 into an appropriate portion of the band support surface 66.
[0050]
Corresponding cable see-through holes 91a and 91b are respectively provided in the pair of abutting end portions 91A and 91B of the band member 91, and the bulging portion 65 corresponds to the cable see-through holes 91a and 91b. A through-hole 65a is formed in the front-rear direction. The cable 93 has the nipple 93a at the end thereof positioned on the outer surface of the front end 91A, and the cable through-holes 91a and 91b of the end 91A and 91B and the bulge 65 It is inserted into the through hole 65a. In this embodiment, a compression coil spring 91C is interposed between the pair of abutting end portions 91A and 91B so as to be inserted into the cable 93, whereby the pair of abutting end portions 91A. , 91B are always urged in the expanding direction. This means that the cable 93 is always elastically biased forward. The compression coil spring 91C can be omitted when the band member 91 has a spring property.
[0051]
The cable 93 employs a so-called Bowden cable into which the outer cylinder 94 is inserted, and one end portion 94a of the outer cylinder 94 expands the rear end of the cable through hole 65a in the bulging portion 65. The outer receiver 65b is held.
[0052]
For example, the cable 93 is routed along the operation tube 10 and is connected to an operation lever 95 attached to an appropriate portion of the operation tube 10.
[0053]
As shown in FIGS. 9 to 12, the operation lever 95 includes a base member 96 fixed to the operation tube 10, and a lever arm 97 that is rotatably supported about the shaft 98 with respect to the base member 96. With. The cable 93 is connected to the lever arm 97 by engaging and holding a nipple 93b at an end of the cable 93 in a nipple holding hole 97a provided in an appropriate portion of the lever arm 97. The outer cylinder 94 is held by an outer receiver 96 a formed integrally with the base member 96. In this embodiment, by rotating the lever arm 97 in the direction of arrow P in FIG. 9, the cable 93 can be pulled relative to the outer cylinder 94, and the lever arm 97 can be pulled in the direction indicated by the arrow Q in FIG. When turning back in the direction, the cable 93 is fed out relative to the outer cylinder 94. The lever arm 97 is rotated in the direction of the arrow P by an operator's operation, and the return rotation in the direction of the arrow Q is interposed between the pair of abutting end portions 91A and 91B of the band member 91 described above. This is performed by the elasticity of the compression coil spring 91C.
[0054]
In this embodiment, the operating lever 95 releases the latched state by the latch mechanism 9A that can hold the turning state of the lever arm 97 when the lever arm 97 is turned by a predetermined amount in the direction of arrow P. A device provided with a release mechanism 9B is employed.
[0055]
As shown in FIG. 10, the base member 96 is formed with a pair of side walls 96b covering both sides of the base end side of the lever arm 97, and one side wall 96b is always outward by a spring 96c. The pin member 96d urged by is held while the travel stroke is restricted to a certain range. A notch 96e having a predetermined axial width is formed on the inner side surface of the pin member 96d. On the other hand, the lever arm 97 has a thickness that interferes with the pin member 96d and has a thickness corresponding to the width of the notch 96e of the pin member 96d in a fixed rotation angle range α in a side view. 97b is provided.
[0056]
When the lever arm 97 is rotated in the direction of the arrow P by a predetermined amount, the pin member 96d does not interfere with the lever arm 97 in a side view as shown by an imaginary line in FIG. At this time, when the pin member 96d is pushed against the elasticity of the spring 96c to release the operating force on the lever arm 97, the lever arm 97 is automatically moved in the direction of the arrow Q by the return biasing force via the cable 93. Returning, as shown in FIGS. 11 and 12, the locking portion 97b engages with the notch 96e of the pin member 96d, thereby preventing further return rotation in the arrow Q direction. Since the pin member 96d is engaged with the notch 96e of the locking portion 97b of the lever arm 97, the pin member 96d is held in the pushed state and does not return. In this way, the latch mechanism 9A is configured that is held in a state where the lever arm 97 is rotated by a predetermined amount in the direction of arrow P.
[0057]
On the other hand, when the lever arm 97 is slightly forcibly rotated in the direction of arrow P from the above latched state, the engaged state between the locking portion 97b of the lever arm 97 and the notch 96e of the pin member 96d is released. Therefore, the pin member 96d automatically returns to the state before being pushed in by the elasticity of the spring 96c. At this time, since there is no member that obstructs the return rotation of the lever arm 97 in the arrow Q direction, the lever arm 97 automatically returns in the arrow Q direction by releasing the operating force. Thus, the release mechanism 9B that releases the latch mechanism 9A is configured.
[0058]
The latch mechanism 9A and the release mechanism 9B are not limited to the above-described configuration. For example, the latch mechanism 9A and the release mechanism 9B are automatically latched when the lever arm 97 is rotated by a predetermined amount in the arrow P direction. 9A may be released.
[0059]
In the above configuration, in a state where the lever arm 97 of the operation lever 95 is rotated by a predetermined amount P direction and latched, the band member 91 tightens the winding drum portion 74 to rotate the winding drum portion 74. Since the braking force is applied to the connecting first member 6, the position of the connecting second member 7 around the lateral axis 14 does not change. Since the contact area between the band member 91 and the winding drum portion 74 at this time is relatively wide, a large braking force can be obtained, and the posture holding of the connected second member 7 or the rotary blade support member 30 is stable. Become.
[0060]
On the other hand, when the latch of the lever arm 97 of the operation lever 95 is released and the lever arm 97 is returned in the direction of the arrow Q, the tightening force, that is, the braking force, of the band member 91 to the winding drum portion 74 is released, so The two members 7 or the rotary blade support member 30 are in a state of being able to rotate almost freely around the lateral axis 14.
[0061]
At this time, for example, the angle of the rotary blade 31 with respect to the operation tube 10 is adjusted as desired by applying an appropriate portion of the rotary blade 31 to the ground, and the lever arm 97 of the operation lever 95 is moved to an arrow. Rotate in P direction and latch. Thereby, the connection 2nd member 7 thru | or the rotary blade support member 30 are hold | maintained in the state after the angle adjustment of the surroundings of the horizontal direction axis | shaft 14 as mentioned above.
[0062]
As a result, for example, when performing a brushing operation such as a slope with a raised toe, a slope with a lowered toe, or a slope on the bank, the operation tube is used to make the rotary blade 31 take an appropriate posture with respect to these slopes. The operation of changing the angular posture of the rotary blade 31 with respect to 10 can be performed quickly and easily.
[0063]
In the embodiment shown in the figure, the transmission shaft 40 is in a bare state at the portion inserted through the connection first member 6 or the connection second member 7, so that the transmission shaft 40 is as described above. The rotation of the connection second member 7 relative to the connection first member 6 is not hindered more than necessary. Further, the transmission shaft insertion holes 61a and 71a provided in the respective cylindrical portions 61 and 71 of the connection first member 6 and the connection second member 7 are tapered so that the vertical width increases as the vicinity of the lateral axis 14 is approached. Therefore, as shown in FIG. 3, even if the connecting first member 6 and the connecting second member 7 change from a state in which the connecting first member 6 and the connecting second member 7 extend linearly to a bent state around the lateral axis 14, the transmission shaft 40 The inside of the transmission shaft insertion holes 61a and 71a can be gently curved. Therefore, there is no unreasonable burden on the transmission shaft 40, and it is possible to prevent the transmission shaft 40 from rotating and being damaged in an inadvertent contact with the first connecting member 6 or the second connecting member 7. Can do.
[0064]
Further, the portable power brush cutter 1 having the above-described configuration is positioned such that the rotation center (lateral axis 14) of the rotary blade support member 30 with respect to the distal end portion of the operation tube 10 substantially intersects the axis of the operation tube 10. Therefore, even when the rotary blade support member 30 is rotated around the lateral axis 14, the center of gravity of the rotary blade support member 30 is not greatly separated from the axis of the operation tube 10. Therefore, when the operation tube 10 is swung left and right as described above in the brushing operation, the operation tube 10 rotates due to the influence of the inertial force, so that the rotary blade 31 swings left and right. It is possible to continue the brush cutter operation stably.
[0065]
Of course, the scope of the present invention is not limited to the above-described embodiments, and all modifications within the scope of the matters described in each claim are included in the scope of the present invention.
[0066]
The configuration for supporting the rotary blade support member 30 so as to be rotatable about the lateral axis 14 with respect to the distal end portion of the operation tube 10 is not limited. For example, in the present embodiment, the pair of second connection walls 72, 72 provided on the connection second member 7 are arranged outside the pair of first connection walls 62, 62 provided on the connection first member 6. On the contrary, even if the pair of first connection walls 62, 62 are arranged outside the pair of second connection walls 72, 72, the first connection wall 62 and the second connection wall are similarly arranged. Between 72, it can be set as the structure which can mutually rotate using the screw member 8 grade | etc.,.
[0067]
Various specific configurations can also be adopted for the braking means or the band brake as one aspect thereof.
[0068]
Furthermore, in the embodiment, the engine is directly connected to the base end of the operation tube, but the base end of the operation tube and the backpack engine are connected by a flexible tube and a flexible transmission shaft inserted through the flexible tube. Of course, this is also included in the scope of the present invention.
[Brief description of the drawings]
FIG. 1 is an overall perspective view of a first embodiment of a portable power brush cutter according to the present invention.
2 is a cross-sectional view taken along the line II-II in FIG.
3 is a cross-sectional view taken along line III-III in FIG.
4 is a view in the direction of arrows IV in FIG. 1, partially shown in cross section.
5 is a cross-sectional view taken along line VV in FIG.
6 is a partial side sectional view taken along line VI-VI in FIG. 5;
7 is a cross-sectional view taken along line VII-VII in FIGS. 3 and 5. FIG.
8 is a cross-sectional view taken along line VIII-VIII in FIG.
FIG. 9 is a side view for explaining the operating means, partially shown in cross section.
10 is a cross-sectional view taken along line XX of FIG.
FIG. 11 is a side view for explaining the operating means, partially shown in cross section.
12 is a cross-sectional view taken along line XII-XII in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Brush cutter 6 Connection 1st member 7 Connection 2nd member 8 Screw member 8a Shaft part 8b Male screw part 8c Head part 9 Braking means 9A Latch mechanism 9B Release mechanism 10 Operation pipe 11 Clutch housing 12 Clutch drum 14 Lateral axis 17 Grip handle 18 Bracket 20 Engine 30 Rotating blade support member 31 Rotating blade 32 Input shaft 33 Rotating blade mounting shaft 35 Housing 35A Base end side cylinder portion 35B End end side cylinder portion 40 Transmission shaft 50 Holding tube 61 Tube portion 61a Transmission shaft insertion hole 62 First Connection wall 62a Screw hole 63 Mantle portion 63a Stopper portion 64 Bridge portion 65 Swelling portion 66 Band support surface 71 Tube portion 71a Transmission shaft insertion hole 71b Extension portion 72 Second connection wall 72a Hole 73a Stopper portion 74 Winding trunk portion 91 Band members 91A, 91B Abutting end portions 91a, 91b Through hole 91C Compression coil spring 91c Through hole 9 d screw 92 reinforcing ribs 93 cable 93a, 93 b nipple 94 outer tubular 94a one end portion 95 a lever device 96 base member 96a outer receiving 96b sidewall 96c spring 96d pin member 96e notched 97 lever arms 97a nipple holding hole 97b engagement part 98 axis

Claims (5)

An operation tube, a transmission shaft inserted through the operation tube, and a rotary blade supported via a rotary blade support member provided at the tip of the operation tube, the rotational output of the power source is transmitted to the transmission shaft The rotary blade is transmitted to the rotary blade, and the rotary blade is rotated . The rotary blade support member includes an input shaft to which a tip of the transmission shaft is coupled, and the input shaft and the bevel gear mechanism. A rotary blade mounting shaft that is linked to the operation tube, and is supported by the operation tube so that the tip of the operation tube can rotate about a lateral axis that is substantially orthogonal to the axis of the operation tube. A portable power brush cutter,
The transmission shaft has flexibility at least at a portion from the distal end portion of the operation tube to the rotary blade support member,
A first connecting member is provided at the tip of the operation tube, and a second connecting member is provided on the rotary blade support member. The first connecting member and the second connecting member are The transmission shaft is inserted through the connection first member and the connection second member in a penetrating manner, and generally the closer to the horizontal axis, the rotation is connected around the horizontal axis. A conductive shaft insertion hole having a tapered shape with an increasing vertical width is formed, and
By rotating the operation lever provided on the proximal end side of the operation tube, the rotation blade support member can be rotated almost freely around the lateral axis and the rotation is prevented by the braking force. A portable power brush cutter comprising braking means capable of selecting a state to be operated. One of the first connecting member and the second connecting member is formed with a pair of first connecting walls facing each other with the transmission shaft interposed therebetween, and the other of the first connecting member and the second connecting member. Are formed with a pair of second connection walls in contact with the outer surfaces of the pair of first connection walls, and each of the first connection walls and the second connection walls located across the transmission shaft are in the thickness direction thereof. The portable power brush cutter according to claim 1, wherein the portable power brush cutter is connected to each other by a screw member corresponding to the lateral axis. The braking means is a band in which a winding drum portion having the same axis as the lateral axis is provided on the second connecting member, a suitable portion is connected to the first connecting member, and the band is wound around the winding drum portion. the end of the member is configured to displace by the rotation operation of the operation lever, portable power brush cutter according to claim 1 or 2. One end of the cable is connected to the proper portion of the upper Kimisao operation lever, the other end of this cable is connected to the end of the band member, when operated to rotate the operation lever in one direction, the cable The portable power brush cutter according to claim 3 , wherein the band member fastens the winding body portion by displacement of an end portion of the band member via a gap. The portable power cutting device according to claim 4 , wherein the operating lever includes a latch mechanism that prevents return rotation when the control lever is rotated by a predetermined amount in one direction, and a release mechanism that releases the latch mechanism. Payment machine.

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