CN110800450A

CN110800450A - Brush cutter

Info

Publication number: CN110800450A
Application number: CN201810880842.9A
Authority: CN
Inventors: 杨宏军
Original assignee: Individual
Current assignee: Individual
Priority date: 2018-08-04
Filing date: 2018-08-04
Publication date: 2020-02-18

Abstract

The invention provides a brush cutter for preventing cut pieces of a cutting wire from flying towards a user. The brush cutter (10) comprises: an operating lever (12); a wire holder (50) that is driven to rotate at the distal end (12a) of the operating lever (12); a string-shaped cutting line (60) held by the line holder (50); an upper cover (64) that covers at least a part of the range in which the cutting wire (60) rotates from above and from the side; a delivery button (52) provided to the thread holder (50); a trimming blade (80) for cutting off the tip of the cutting line (60); and a reflecting wall (66) for reflecting the cut-off piece of the cutting line (60) cut off by the trimming blade (80) toward the side opposite to the user. In the brush cutter (10), a reflection wall (66) is arranged inside an upper cover (64).

Description

Brush cutter

Technical Field

The present invention relates to a brush cutter for trimming vegetation, and more particularly, to a line brush cutter using a string-like cutting line as a cutter.

Background

Patent document 1 discloses a line type brush cutter. This brush cutter includes: an operating lever; a wire holder that is driven to rotate at a front end of the operation lever; a cutting wire held by the wire holder; an upper cover that covers at least a part of a range in which the cutting wire extending from the wire holder rotates from above and from the side; a thread feeding button provided to the thread holder and configured to feed the cutting thread by pressing the thread feeding button; a trimming knife (trim cutter) for cutting a tip end of the cutting wire fed out from the wire holder; a reflecting wall for reflecting a cut-off piece of the cutting line cut off by the finishing blade toward a side opposite to the user. Patent document 1: specification of us patent No. 4,651,422. In the brush cutter of patent document 1, the cut pieces of the cutting lines are reflected by the reflecting wall, and the cut pieces are prevented from scattering toward the user. However, since the reflecting wall is provided outside the upper cover, the cut piece of the dicing line is expected to be reflected in an unexpected direction.

Disclosure of Invention

The present invention aims to provide a technique for preventing a cut piece of a dicing line from scattering toward a user.

The brush cutter of the invention comprises: an operating lever; a wire holder that is driven to rotate at a front end of the operation lever; a string-like cutting line held by the line holder and having a tip protruding from the line holder; an upper cover that covers at least a part of a range in which the cutting wire extending from the wire holder rotates from above and from the side; a thread feeding button provided to the thread holder and configured to feed the cutting thread by pressing the thread feeding button; a trimming blade for cutting off a tip end of the cutting wire fed out from the wire holder; and a reflecting wall for reflecting the cut-off piece of the cutting line cut off by the trimming blade toward a side opposite to the user. In the brush cutter, the reflecting wall is disposed inside the upper cover.

In the brush cutter, the reflecting wall is disposed inside the upper cover, and therefore, not only the cut pieces of the dicing lines but also the cut pieces of the dicing lines can be reflected by the inner surface of the upper cover. This can more reliably prevent the cut pieces of the dicing line from scattering toward the user.

Preferably, the reflective wall is integrally formed on an inner surface of the upper cover. With this configuration, the gap between the inner surface of the upper cover and the reflective wall can be eliminated, and the cut pieces of the dicing line can be more reliably prevented from scattering toward the user.

Preferably, the reflecting wall is perpendicular to a plane parallel to the central axis of the operation lever and the rotation axis of the wire holder. With this structure, the cut pieces of the dicing line can be prevented from scattering toward the user.

Here, "upper", "lower", and "side" in the present specification are based on the posture of the user when the user normally uses the brush cutter, and specifically refer to "upper", "lower", and "side" when the user grips the operating lever or the handle fixed to the operating lever, directs the wire holder and the cutting wire toward the ground, and the rotation axis of the wire holder and the cutting wire is vertical.

The invention can more reliably prevent the cutting piece of the cutting line from flying towards the user.

Drawings

Fig. 1 is a view showing the entire brush cutter according to the embodiment.

Fig. 2 is a view of the front end portion of the operating lever as viewed obliquely from above.

Fig. 3 is a view of the tip end portion of the operating lever as viewed obliquely from below.

Fig. 4 is a sectional view IV-IV of fig. 1.

Fig. 5 is a view showing the inside of the motor case after opening.

Fig. 6 is a modification of the lower cover, and is a view showing the lower cover having a cutout.

Fig. 7 is a view showing a modification of the cross-sectional shape of the lower cover.

Fig. 8 is a view showing a modification of the cross-sectional shape of the lower cover.

Fig. 9 is a view showing the entire bobbin.

Fig. 10 is a sectional view showing a structure of the base end locking portion of the bobbin.

Detailed Description

The brush cutter 10 of the embodiment is explained with reference to the drawings. The brush cutter 10 is a power tool for gardening, and is used for trimming vegetation. As shown in fig. 1, the brush cutter 10 includes an operating lever 12. A handle 14 and a grip portion 16 are provided at the rear end 12b of the operating lever 12. Typically, the user uses the brush cutter 10 by gripping the handle 14 and the grip 16, respectively. The grip portion 16 is provided with a trigger switch 18 as an activation switch. Further, a battery mounting portion 20 for detachably housing a battery pack 22 is provided below the grip portion 16. The brush cutter 10 of the present embodiment is a cordless brush cutter having a rechargeable battery pack 22 as a power source.

As shown in fig. 1, 2, and 3, a motor housing 30 is provided at the front end 12a of the operating lever 12. The motor case 30 is formed of a resin material. The motor housing 30 is connected to the operation lever 12 via a joint mechanism 32 and is swingable with respect to the operation lever 12. The user can adjust the angle of the motor housing 30 according to his or her height and the inclination of the ground. An unlock button 34 is provided on the joint mechanism 32. When the unlock button 34 is pressed, the joint mechanism 32 can be swung, and when the unlock button 34 is restored, the joint mechanism 32 is fixed.

A wire holder 50 is provided at a lower portion of the motor housing 30. The wire holder 50 is rotatably supported and is driven to rotate by the motor 40 (see fig. 5) in the motor housing 30. The string holding member 50 is used to hold the string-shaped string 60. The tip of the cutting wire 60 protrudes from the wire holder 50 and rotates together with the wire holder 50. The brush cutter 10 of the present embodiment uses the string-like cutting line 60 as a cutter, and cuts vegetation with the cutting line 60 rotating at high speed. For example, the cut line 60 of the present embodiment is a nylon line.

The thread holder 50 is provided with a thread feeding button 52. The thread sending button 52 protrudes downward. When the thread sending-out button 52 is pressed, the cutting thread 60 is sent out from the thread holder 50. The cutting line 60 is easily damaged and is also frequently cut. At this time, the user only needs to press the thread feeding button 52 to the ground without stopping the operation to replace the cutting thread 60. A new cutting wire 60 can be fed out from the wire holder 50 and the user can continue the operation.

An upper cover 64 is provided at the front end 12a of the operating lever 12. The upper cover 64 is mainly formed of a resin material. The upper cover 64 of the present embodiment is attached to the motor housing 30. However, the upper cover 64 may be directly attached to the operating lever 12. The upper cover 64 covers a range in which the cutting wire 60 rotates from above and from the side. The upper cover 64 is substantially fan-shaped in plan view, and the upper cover 64 is provided only in a part (user-side part) of the range in which the string 60 rotates. The upper cover 64 is positioned between the cutting line 60 and the user to prevent objects such as vegetation and stones from being scattered toward the user.

A lower cover 70 is provided at the front end 12a of the operating lever 12. The lower cover 70 includes a disc-shaped cover main body 72 and two

support portions

74a and 74b provided on an outer peripheral edge 72a of the cover main body 72. The lower cover 70 is made of a metal material, and the lower cover 70 is manufactured by bending a metal plate. The two

support portions

74a, 74b of the lower cover 70 are fixed to the upper cover 64. The cover main body 72 of the lower cover 70 is positioned below the cutting wire 60 extending from the wire holder 50, and covers a range in which the cutting wire 60 rotates from below. The diameter of the cover main body 72 is smaller than the diameter of the range in which the cutting wire 60 protruding from the wire holder 50 rotates. Thus, the cover main body 72 covers only the root portion of the dicing line 60, and the tip portion of the dicing line 60 is exposed when viewed from below. In the present embodiment, the lower cover 70 is fixed to the upper cover 64, but the lower cover 70 may be attached to the wire holder 50 via a bearing, for example.

The rotation of the root portion of the cutting line 60 is slow, and therefore, the vegetation cannot be cut substantially. Therefore, it is preferable to cover a range in which the root portion of the cutting line 60 rotates by the lower cover 70. This can inhibit the root portion of the cutting line 60 from making useless contact with vegetation. Since the load applied to the dicing line 60 is reduced, the rotational speed of the dicing line 60 is increased, and the cutting ability of the tip portion of the dicing line 60 is improved. Further, since the energy loss is reduced, the power consumption of the brush cutter 10 can be suppressed, and the operating time of the battery pack 22 can be extended.

An opening 76 is formed in the cover main body 72. The opening 76 is formed in the center of the cover main body 72, and exposes the thread holder 50 and the thread dispensing button 52 downward. The thread sending button 52 protrudes below the cover main body 72 through the opening 76. Thus, even in a state where the lower cover 70 is attached, the string feeding button 52 can be pressed against the ground surface to feed the string 60 from the string holder 50.

As shown in fig. 6, lower cover 70 may have a cutout 78 in a portion of cover main body 72 in the circumferential direction, and lower cover 70 may have a substantially fan-shape in plan view. In this case, notch 78 preferably extends from outer peripheral edge 72a of cover main body 72 to central opening 76. With this configuration, the user can easily perform the operation without being disturbed by the lower cover 70 when attaching the string 60 to the string holder 50. Here, the notch 78 is preferably located below the operation lever 12. This is because, in general, in the range below the operating lever 12 (i.e., the range on the user side with respect to the string holder 50), the vegetation is trimmed, and therefore, even if the cutout portion 78 is provided in the cover main body 72 in this range, the vegetation is less likely to contact the root portion of the cutting string 60.

Alternatively, a movable cover may be provided to the notch 78 of the cover main body 72. With this structure, it is possible to inhibit the vegetation from contacting the root portion of the cut line 60 by closing the cover in advance at normal times. On the other hand, when the user attaches the string 60 to the string holder 50, the user can easily perform the work by opening the cover without being interfered by the lower cover 70.

Next, the cross-sectional shape of the lower cover 70 will be described. As shown in fig. 4, the cover main body 72 of the lower cover 70 is not completely planar, but is three-dimensionally curved. In particular, the outer peripheral edge 72a of the cover main body 72 is bent upward. Thus, when the outer peripheral edge 72a of the cover main body 72 is bent or bent upward, the outer peripheral edge 72a can be prevented from catching on vegetation or the ground. Thereby, the operator can smoothly operate the brush cutter 10 along the ground. Further, the cover main body 72 of the present embodiment is gently curved upward from the opening 76 toward the outer peripheral edge 72 a. Thus, when the cover main body 72 is curved convexly downward as a whole, the user can operate the brush cutter 10 more smoothly.

Further, a projection 76a projecting upward (toward the dicing line 60) is provided at the peripheral edge of the opening 76 of the cover main body 72. With this configuration, the cutting wire 60 can be prevented from entering the gap between the opening portion 76 and the wire holder 50. Thereby, the cutting line 60 can be prevented from being entangled or cut. Although the projection 76a of the present embodiment surrounds the entire periphery of the opening 76, the opening 76a may be formed intermittently along the periphery of the opening 76 in other embodiments.

The cross-sectional shape of the lower cover 70 can be variously changed. Fig. 7 and 8 show examples of the cross-sectional shape of the lower cover 70. In the lower cover 70 shown in fig. 7 and 8, the outer peripheral edge 72a of the cover main body 72 is also bent upward, and the outer peripheral edge 72a is prevented from catching on vegetation or the ground. Further, a projection 76a projecting upward is provided at the periphery of the opening 76, and the projection 76a prevents the cutting line 60 from being entangled or cut. Further, since the entire cover main body 72 is curved downward in a convex shape, the user can smoothly operate the brush cutter 10. In the lower cover 70 shown in fig. 7, the radially intermediate position 72b of the cover main body 72 protrudes most downward.

As shown in fig. 2 and 3, a trimming blade 80 is integrally provided on the lower cover 70. The finishing blade 80 is formed at the edge of the support portion 74a of the lower cover 70. The trimming blade 80 is used to cut off the tip of the cutting wire 60 excessively fed from the wire holder 50 and trim the cutting wire 60 protruding from the wire holder 50 to an appropriate length.

A reflecting wall 66 is formed in the vicinity of the dressing blade 80. The reflecting wall 66 is located on the outer side (the side opposite to the wire holder 50) of the trimming blade 80 for reflecting the cut piece of the cutting wire 60 cut by the trimming blade 80 toward the side opposite to the user. In the brush cutter 10 of the present embodiment, the reflecting wall 66 is disposed inside the upper cover 64. With this configuration, not only the cut piece of the dicing line 60 can be reflected by the reflecting wall 66, but also the cut piece of the dicing line 60 can be reflected by the inner surface 64a of the upper cover 64. This can more reliably prevent the cut pieces of the dicing line 60 from scattering toward the user. In addition, the reflecting wall 66 can be prevented from being damaged by contact with an external object.

The reflecting wall 66 of the present embodiment is integrally formed on the inner surface 64a of the upper cover 64. With this configuration, the gap between the inner surface 64a of the upper cover 64 and the reflecting wall 66 can be eliminated, and the cut pieces of the dicing line 60 can be more reliably prevented from scattering toward the user.

The position where the reflecting wall 66 is formed and the orientation of the reflecting wall 66 can be appropriately designed. However, according to the experiments of the present inventors, when the reflecting wall 66 is designed to be perpendicular to the plane parallel to the central axis of the operating lever 12 and the rotational axis of the string holder 50, the cut pieces of the cutting string 60 can be most prevented from scattering toward the user.

Next, the internal structure of the motor case 30 will be described with reference to fig. 4 and 5. The motor housing 30 houses an electric motor 40 as a prime mover of the brush cutter 10. The motor 40 is electrically connected to the battery pack 22 (see fig. 1), and operates by electric power supplied from the battery pack 22. Further, a pinion gear 42 fixed to the motor 40, a driven gear 44 engaged with the pinion gear 42, and a main shaft 46 to which the driven gear 44 is fixed are accommodated in the motor housing 30. The main shaft 46 is supported to be rotatable with respect to the motor case 30. A wire holder 50 is fixed to a lower end of the driven gear 44. With the above configuration, the wire holder 50 is mechanically connected to the motor 40, and the wire holder 50 is driven by the motor 40 to rotate.

The internal structure of the joint mechanism 32 will be described with reference to fig. 5. The unlock button 34 of the joint mechanism 32 has a flange portion 36. The flange portion 36 has a substantially hexagonal outer shape, and the unlock button 34 is supported so as not to be rotatable with respect to the operation lever 12. A plurality of ribs 38 arranged in the circumferential direction are formed at the flange portion 36 of the unlock button 34. A plurality of ribs (not shown) corresponding to the ribs 38 are also formed on the inner surface of the motor housing 30. Normally, the unlock button 34 is biased toward the motor housing 30, and the rib 38 of the unlock button 34 is engaged with the rib of the motor housing 30. In this case, the motor case 30 is prohibited from swinging with respect to the operation lever 12. On the other hand, when the unlock button 34 is pressed, the engagement of the rib 38 is released, and the motor case 30 is allowed to swing with respect to the operation lever 12. Since the unlock button 34 is disposed on the rotation axis of the joint mechanism 32, the user can easily adjust the angle of the motor housing 30 while pressing the unlock button 34.

A rubber pin 39 is also provided at the joint mechanism 32. The rubber pin 39 is a pin member formed of a rubber material. The rubber pin 39 is fixed to the motor housing 30 and contacts the front end 12a of the operating lever 12 that swings relative to the motor housing 30. When the user swings the motor housing 30 relative to the operating lever 12, the rubber pin 39 slides relative to the distal end 12a of the operating lever 12, and generates an appropriate frictional force. As a result, the user feels a moderate feeling of collision, and the angle of the motor housing 30 is easily adjusted.

The internal configuration of the wire holder 50 is explained with reference to fig. 4. The wire holder 50 houses a spool 54. A cutting line 60 is wound on the spool 54. The above-described thread feeding button 52 is fixed to the spool 54. The wire feeding button 52 and the spool 54 are biased downward by the spring 58, and normally, the wire feeding button 52 and the spool 54 cannot rotate with respect to the wire holder 50. When the thread sending-out button 52 is pressed in a state where the thread holder 50 is rotated, the bobbin 54 is separated from the thread holder 50, and the bobbin 54 can be rotated with respect to the thread holder 50. At this time, the cutting wire 60 wound around the spool 54 is fed out by centrifugal force acting on the cutting wire 60 protruding from the wire holder 50.

The structure of the bobbin 54 is explained with reference to fig. 9 and 10. As described above, the wire feed button 52 is fixed to the spool 54. A base end locking portion 56 is provided on the flange 54a of the bobbin 54. The base end locking portion 56 is a portion that locks the base end of the cutting wire 60 in advance when the cutting wire 60 is wound around the spool 54. Since the base end locking portion 56 is formed on the outer surface of the flange 54a, the wire passing hole 54b through which the cutting wire 60 passes is formed in the flange 54a of the spool 54.

Fig. 10 is a cross-sectional view of the bobbin 54 cut by the cylindrical surface passing through the base end locking portion 56, and shows the inside of the base end locking portion 56. As shown in fig. 10, the base end locking portion 56 includes a locking hole 56a, a holding groove 56b, and a guide slope 56 c. The locking hole 56a is a hole into which the base end of the cutting wire 60 is inserted. Since the locking hole 56a opens in the axial direction of the wire shaft 54, the user can easily insert the base end of the cutting wire 60 into the locking hole 56 a. The cutting wire 60, the base end of which has been inserted into the click hole 56a, is guided into the wire passing hole 54b formed in the flange 54a by the holding groove 56b and the guide slope 56 c. Here, the guide slope 56c connected to the wire passing hole 54b is inclined in the circumferential direction. Thus, the cutting line 60 is smoothly guided without being excessively bent, and the user easily winds the cutting line 60 into the spool 54.

The embodiments of the present invention have been described in detail, but these are merely examples and are not intended to limit the claims. The specific examples described above are intended to be encompassed by the technology described in the claims, with various modifications and changes made thereto.

The technical features described in the present specification or drawings are effective in terms of technology alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. The technique exemplified in the present specification or the drawings is for achieving a plurality of objects at the same time, and a technique for achieving one of the objects itself has technical usefulness.

Claims

1. A brush cutter is characterized in that: this brush cutter includes: an operating lever; a wire holder that is driven to rotate at a front end of the operation lever; a string-like cutting line held by the line holder and having a tip protruding from the line holder; an upper cover that covers at least a part of a range in which the cutting wire extending from the wire holder rotates from above and from the side; a feed button provided to the wire holder and configured to feed the cutting wire by pressing the wire feed button; a trimming blade for cutting off a tip end of the cutting wire fed out from the wire holder; and a reflecting wall for reflecting the cut-off piece of the cutting line cut off by the trimming blade toward a side opposite to the user; the reflecting wall is disposed inside the upper cover.

2. The brush cutter according to claim 1, wherein: the reflecting wall is integrally formed on the inner surface of the upper cover.

3. The brush cutter according to claim 1 or 2, characterized in that: the reflecting wall is perpendicular to a plane parallel to the center axis of the operation lever and the rotation axis of the wire holder.