Grass trimmer

Abstract

To provide a grass trimmer that reduces the labor burden on workers, allows for efficient and safe grass cutting, and can also operate on slopes. [Solution] The grass trimmer 1 is moved by a movable arm 91 provided on a hydraulic excavator, and comprises an attachment 40 attached to the tip of the movable arm 91, a main body 10 detachably attached to the attachment 40, a motor 30 supported by the main body 10, and a blade 35 that rotates by the driving force of the motor 30.

Description

Technical Field

[0001] The present invention relates to a grass cutting machine.

Background Art

[0002] Conventionally, a brush cutter has been used as a cutting machine for grass cutting. The brush cutter has a blade that rotates by the driving force of a prime mover at the tip of a long handle. An operator cuts grass by turning the handle while holding and moving the handle. The blade employs a nylon cutter made of a nylon string, a chip saw in which a plurality of alloy tips are embedded on the outer periphery of a disk, or a circular saw blade such as a circular saw. The prime mover employs an engine type or an electric type. In the brush cutter disclosed in Patent Document 1, the prime mover is electric.

[0003] However, since the brush cutter needs to be configured to be turned by a person holding it, the number of blades is limited to one and the length of the handle is also limited. Therefore, the area that can be cut by one turning operation is small and the efficiency is poor. In addition, when using a brush cutter, an operator needs to maintain a state in which the handle is lifted so that the blade is separated from the ground, which also has a drawback of a large labor burden. When the blade contacts a stone on the ground, there is a risk that the stone will fly and hit the operator. There is also a drawback that the work cannot be performed on a sloping ground where it is difficult for an operator to maintain a posture, such as a slope.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Therefore, in view of the above circumstances, the present invention aims to provide a grass cutting machine that can cut grass and trees efficiently and safely while reducing the labor burden on the worker, and that can also operate on slopes. [Means for solving the problem]

[0006] To solve the above problems, the grass trimmer according to the present invention is "A grass trimmer that moves using a movable arm equipped on the vehicle, An attachment to be attached to the tip of the movable arm, The main body is detachably attached to the aforementioned attachment, The motor is supported by the main body, The blade rotates due to the driving force of the motor and It is "equipped with."

[0007] In this configuration of brush cutter, the main body is attached to an attachment mounted on a movable arm of a vehicle. A motor supported by the main body rotates and drives the blade. The vehicle mentioned above is, for example, a hydraulic excavator, and the attachment is mounted in place of the bucket of the hydraulic excavator. As a result, the operator does not have to lift the handle with their own strength as with conventional brush cutters, but can cut grass and weeds using the blade of the main body by mechanically operating the movable arm while riding on the vehicle. Therefore, the burden of labor on the operator is reduced.

[0008] Furthermore, using mechanical power as in this configuration makes it easy to use relatively large blades that would be difficult to lift and maintain with human strength, and to use multiple such blades. As a result, compared to conventional brush cutters, the area that can be cut with a single rotation can be increased, allowing for more efficient cutting of vegetation.

[0009] Furthermore, since the operator operates the machine from the driver's seat of the vehicle equipped with a movable arm, away from the blade, the risk of flying stones hitting the operator is reduced, thus increasing safety. Also, even when mowing vegetation on slopes, the movable arm can be extended, allowing the vehicle itself to be positioned stably on flat ground while mowing the vegetation.

[0010] Here, "cutting plants and trees" includes not only "grass cutting" of grass growing on the ground, but also "pruning" of excess or dead branches, and "trimming" of hedges and other plants to maintain their shape.

[0011] For example, the blade can be made from a carbide-tipped saw blade, a circular saw blade, a blade cutter, or a nylon cutter. The motor may be a hydraulic motor or an electric motor. The hydraulic pressure and electricity required to operate the motor may be supplied from the vehicle.

[0012] The grass trimmer according to the present invention has the above configuration in addition to the above configuration, "A protruding portion having one end fixed to and protruding from either the attachment or the main body, An insertion portion is provided on the other side of the attachment and the main body, into which the protruding portion is inserted, An angle adjustment mechanism that varies the angle of the main body relative to the attachment by the rotation angle of the protruding portion around an axis parallel to the insertion direction of the insertion portion, It can be made to "further possess the following characteristics."

[0013] This configuration features an angle adjustment mechanism that allows the angle of the main body relative to the attachment to be varied by changing the rotation angle of the protruding part around an axis parallel to the insertion direction of the protruding part into the insertion part. This allows the angle of the main body relative to the attachment to be changed by rotating the protruding part around the axis and changing the rotation angle of the protruding part relative to the insertion part. As a result, the blade can be tilted to match the slope of the ground, making it easier to mow grass on slopes. In addition, the degree of freedom in the blade's position when performing pruning or branch trimming work is increased, making those tasks easier.

[0014] The grass trimmer according to the present invention has the above configuration in addition to the above configuration, "When the end of the main body closest to the attachment is referred to as the base end, and the end opposite to the base end is referred to as the tip, the main body may further be provided with a horizontal bar for collecting grass that is supported by the main body and extends in the front-rear direction from the base end to the tip."

[0015] In conventional brush cutters, the cut grass remains in place, requiring manual collection, which is a labor-intensive task. In contrast, this configuration features a horizontal grass-collecting bar supported by the main body, extending in the front-to-back direction. As a result, while the movable arm is rotating in one direction, the cut grass is pushed and moved by the horizontal grass-collecting bar. When the rotation direction of the movable arm is changed from one direction to the other, the grass pushed by the horizontal grass-collecting bar is placed on the ground at the point of the change in rotation direction. Therefore, the cut grass can be gathered at both ends of the movable arm's rotation direction while cutting, significantly reducing the need for manual collection and further alleviating the labor burden. [Effects of the Invention]

[0016] As described above, the present invention provides a grass cutting machine that can cut grass and trees efficiently and safely while reducing the labor burden on the worker, and can also be used on slopes. [Brief explanation of the drawing]

[0017] [Figure 1] This is a perspective view of a brush cutter, which is one embodiment of the present invention. [Figure 2] Figure 1 is an exploded perspective view of the grass trimmer. [Figure 3] Figure 1 is a side view of the grass trimmer. [Figure 4]The figure of the connection part and attachment of FIG. 1, where (a) is an exploded perspective view in the horizontal cutting state, (b) is an exploded perspective view in the diagonal cutting state, and (c) is an exploded perspective view in the vertical cutting state. [Figure 5] A perspective view showing the state where the grass cutter of FIG. 1 is attached to the movable arm of a hydraulic excavator, and it is a view showing the horizontal cutting state. [Figure 6] A perspective view showing the state where the grass cutter of FIG. 1, with the horizontal bar for collecting grass, the anti - toppling horizontal bar, and the vertical bar removed, is attached to the movable arm of a hydraulic excavator, and it is a view showing the diagonal cutting state.

Mode for Carrying Out the Invention

[0018] Hereinafter, the grass cutter 1 which is an embodiment of the present invention will be described with reference to FIGS. 1 to 6. The grass cutter 1 is a cutting machine equipped with a rotary blade for cutting grass, and is used in a hydraulic excavator which is one of the "vehicles equipped with a movable arm". The hydraulic excavator includes a lower traveling body and an upper revolving body that revolves with respect to the lower traveling body (not shown). A movable arm 91 is attached to the upper revolving body (see FIGS. 5 and 6).

[0019] The movable arm 91 has the same structure as that of a known hydraulic excavator. Specifically, the movable arm 91 includes an arm portion 92 extending from the revolving center side of the upper revolving body, a link mechanism 93 attached to the arm portion 92, and a hydraulic cylinder 98 having a cylinder rod 99 connected to the link mechanism 93. The link mechanism 93 is a four - link mechanism having links 94a, 94b, 94c, 94d and joints 95a, 95b, 95c, 95d, and is provided on both sides of a portion near the tip of the arm portion 92. The two link mechanisms 93 are configured to interlock by using common joints 95a, 95b, 95c, 95d.

[0020] To explain each link mechanism 93 in detail, one end of link 94a is rotatably supported by a joint 95a at the tip of the arm portion 92. One end of link 94b is rotatably supported by a joint 95b at a position slightly away from the tip of the arm portion 92. As a result, the portion of the arm portion 92 between joints 95a and 95b constitutes link 94c. The other end of link 94a is rotatably supported by a joint 95c at one end of link 94d, and the other end of link 94b is rotatably supported by a joint 95d at the other end of link 94d. The tip of the cylinder rod 99 is fixed to a sleeve 99b that is rotatable around the axis of joint 95d by inserting it through joint 95d. With this configuration, when the hydraulic cylinder 98 drives the cylinder rod 99 forward and backward, link 94a rotates around the axes of joints 95a and 95c, and link 94b rotates around the axes of joints 95b and 95d, while link 94d moves together with the cylinder rod 99.

[0021] First, let's describe the configuration of the grass trimmer 1. The grass trimmer 1 comprises a main body 10, a motor 30, a blade 35, an attachment 40, a connecting part 50, vertical bars 60 and 65, a horizontal bar for collecting grass 70, a horizontal bar for preventing tipping over 75, and a downward extension part 80. Note that the attachment 40 is not shown in Figures 1 to 3.

[0022] The main body 10 is the main structure that performs the cutting action in the grass trimmer 1, and is detachably attached to the attachment 40 via the connecting part 50. Hereinafter, the end of the main body 10 closest to the attachment 40 will be referred to as the "base end," and the end opposite the base end will be referred to as the "tip end." Also, the tip side relative to the base end will be referred to as the "front," and the opposite side as the "rear." In this embodiment, the main body 10 comprises a pair of shaft parts 11, a base end connecting part 12, a tip connecting part 13, a plurality of motor fixing plates 14 (three are shown as examples here), a base end plate 15, and a tip plate 16. Each shaft part 11 is a hollow shaft extending in the front-rear direction. The pair of shaft parts 11 are arranged parallel to each other with a gap in between in a direction perpendicular to the front-rear direction (hereinafter referred to as the "width direction").

[0023] The base end connecting portion 12 has a U-shaped cross-section that opens forward and holds the base ends (rear ends) of the pair of shaft portions 11 within its opening. The tip connecting portion 13 has a U-shaped cross-section that opens rearward and holds the tip ends (front ends) of the pair of shaft portions 11 within its opening. Thus, the pair of shaft portions 11, the base end connecting portion 12, and the tip connecting portion 13 constitute a frame-like structure.

[0024] The base end connecting portion 12 has a cylindrical first connecting cylindrical portion 21 that protrudes upward in a direction perpendicular to the front-rear direction and the width direction (hereinafter referred to as the "up-down direction") (see Figure 2). The tip connecting portion 13 has a cylindrical second connecting cylindrical portion 22 that protrudes upward in the up-down direction (see Figure 2).

[0025] Multiple motor fixing plates 14 are arranged with a gap in the front-rear direction between the base end connecting portion 12 and the tip connecting portion 13, and are fixed to a pair of shaft portions 11. Two motor fixing plates 14 that are adjacent in the front-rear direction are arranged so that their positions in the vertical direction are different (see Figure 3). In this embodiment, of the three motor fixing plates 14, the middle motor fixing plate 14 is fixed to the vertical center of the shaft portion 11. On the other hand, the motor fixing plates 14 on both sides in the front-rear direction are fixed to the lower end of the shaft portion 11.

[0026] There are as many motors 30 as there are motor mounting plates 14, and each motor 30 is supported by a separate motor mounting plate 14. The output shaft 31 of each motor 30 passes through the motor mounting plate 14 and protrudes downward in the vertical direction relative to the main body 10 (see Figure 3). The motors 30 are hydraulic motors and are operated by hydraulic pressure supplied from the hydraulic circuit of the hydraulic excavator via hydraulic hoses (not shown).

[0027] The blade 35 rotates due to the driving force of the motor 30. In this embodiment, the blade 35 is made of a circular saw blade. The same number of blades 35 as there are motors 30, and each blade 35 is attached to the tip of the output shaft 31 of another motor 30. Two adjacent blades 35 in the front-to-back direction are arranged so as to partially overlap when viewed from directly above. As described above, the motor fixing plate 14 is positioned so that adjacent blades 35 are in different positions in the vertical direction, thus preventing them from interfering with each other.

[0028] In this embodiment, each of the multiple motors 30 is supported by a separate motor mounting plate 14, and the multiple motor mounting plates 14 are spaced apart in the front-rear direction in order to reduce the weight of the structure for supporting the multiple motors 30. Multiple motors may be supported by a single motor mounting plate, but in that case, the protrusion length from the motor mounting plate of the output shafts of adjacent motors is adjusted to avoid interference between adjacent blades.

[0029] The base plate 15 is a flat plate-shaped member extending rearward from the base connecting portion 12. The base plate 15 has a cylindrical third connecting cylindrical portion 23 that protrudes upward in the vertical direction (see Figures 2 and 4). The third connecting cylindrical portion 23 is sized to accommodate the first connecting cylindrical portion 21 of the base connecting portion 12. The first connecting cylindrical portion 21 is inserted into the interior of the third connecting cylindrical portion 23 by passing through a through hole (not shown in the drawings) in the base plate 15 that communicates with the internal space of the third connecting cylindrical portion 23. The first connecting cylindrical portion 21 and the third connecting cylindrical portion 23 are then fixed together by bolts or pins (not shown) that pass through them. As a result, the base plate 15 is integrated with the main body portion 10 via the base connecting portion 12.

[0030] The tip plate 16 is a flat plate-shaped member extending forward from the tip connecting portion 13. The tip plate 16 is provided with a cylindrical fourth connecting cylindrical portion 24, a fifth connecting cylindrical portion 25, and a sixth connecting cylindrical portion 26 that protrude upward in the vertical direction, in order from rear to front (see Figure 2). The fourth connecting cylindrical portion 24 is sized to accommodate the second connecting cylindrical portion 22 of the tip connecting portion 13. The second connecting cylindrical portion 22 is inserted into the interior of the fourth connecting cylindrical portion 24 by passing through a through hole (not shown in the drawing) in the tip plate 16 that communicates with the internal space of the fourth connecting cylindrical portion 24. The second connecting cylindrical portion 22 and the fourth connecting cylindrical portion 24 are then fixed together by a bolt or pin (not shown) that passes through them. As a result, the tip plate 16 is integrated with the main body portion 10 via the tip connecting portion 13.

[0031] As described above, the multiple blades 35 are arranged in a front-to-back direction, but even the blade 35 located furthest forward is positioned behind the front end of the tip plate 16. In other words, the tip plate 16 extends further forward than the furthest forward blade 35.

[0032] The attachment 40 is a connector for connecting and holding the main body 10 to the movable arm 91, and is detachably attached to the tip of the movable arm 91. The attachment 40 can be attached in place of other attachments used in hydraulic excavators, such as buckets or grapples. In this embodiment, the attachment 40 has a flat base portion 41, a pair of flange portions 42 erected perpendicularly from the base portion 41 at the rear end of the base portion 41, and another pair of flange portions 44 erected perpendicularly from the base portion 41 at a position slightly forward from the flange portions 42. Each flange portion 42 has a through hole 43 through which the joint 95a of the link mechanism 93 is inserted. Each flange portion 44 has a through hole 45 through which the joint 95c is inserted. This allows the attachment 40 to rotate around the axis of the joint 95a via the joint 95d by moving the cylinder rod 99 of the hydraulic cylinder 98 forward and backward to raise and lower the joint 95d. In other words, the angle of the attachment 40 with respect to the horizontal plane can be changed by moving the cylinder rod 99 of the hydraulic cylinder 98 forward and backward. Also, when the movable arm 91 is rotated, the attachment 40 rotates together with the movable arm 91.

[0033] The connecting portion 50 is the part for connecting the main body portion 10 to the attachment 40. Specifically, the connecting portion 50 includes a protruding portion 51, one end of which is fixed to the main body portion 10 and protruding from the main body portion 10; an insertion portion 53 provided on the attachment 40 into which the protruding portion 51 is inserted; and an angle adjustment mechanism 57 that makes the rotation angle of the protruding portion 51 relative to the insertion portion 53 variable.

[0034] In this embodiment, the projection 51 is a cylindrical member extending in the front-rear direction. The front end of the projection 51 is fixed to the base plate 15 by a joint 54. The insertion part 53 is a cylindrical member fixed to the base part 41 by a joint 55. The inner diameter of the insertion part 53 is slightly larger than the outer diameter of the projection 51. The rear end of the projection 51 protrudes rearward from the base plate 15 and is inserted into the insertion part 53. The angle adjustment mechanism 57 consists of a through hole 56 provided in the joint 55, a through hole (not shown in the drawing) provided in the insertion part 53 so as to communicate with the through hole 56, a through hole 52 provided in the projection 51, a bolt 58 inserted through the through holes 52 and 56, and a nut 59 screwed onto the bolt 58. Multiple through holes 52 are provided on a spiral line around the central axis P of the projection 51. The central axis P is the central axis of the cylindrical projection 51 and is parallel to the direction in which the projection 51 is inserted into the insertion portion 53.

[0035] The main body 10 can be attached to the attachment 40 by inserting the protruding portion 51 into the insertion portion 53, aligning one of the through holes 52 with the through hole 56, passing a bolt 58 through both, and fastening it with a nut 59. Furthermore, the angle adjustment mechanism 57 allows the angle of the main body 10 relative to the attachment 40 to be changed by changing the angle of the protruding portion 51 relative to the insertion portion 53. Specifically, with the bolt 58 and nut 59 unscrewed, the angle of the protruding portion 51 relative to the insertion portion 53 can be changed by rotating it around the central axis P, thereby changing the angle of the protruding portion 51 relative to the insertion portion 53, and thus changing the angle of the main body 10 relative to the attachment 40. In this embodiment, the cutting position can be changed to a horizontal cutting position where the attachment 40 and the main body 10 are parallel (see Figure 4(a)), an oblique cutting position where the main body 10 is rotated 45° relative to the attachment 40 from the horizontal cutting position (see Figure 4(b)), and a vertical cutting position where the main body 10 is rotated 90° relative to the attachment 40 from the horizontal cutting position (see Figure 4(c)). By varying the angular spacing around the central axis P for the multiple through holes 52 provided on the spiral line around the central axis P, the angular unit in which the angle of the main body 10 relative to the attachment 40 can be adjusted can be changed.

[0036] The vertical bars 60 and 65 are elongated rods and both protrude upward from the main body 10. In this embodiment, the lower ends of the vertical bars 60 and 65 are detachably attached to the main body 10. Vertical bar 60 is attached to the base end of the main body 10, and vertical bar 65 is attached to the tip end of the main body 10. In the vertical direction, the vertical bars 60 and 65 are provided on the side of the main body 10 opposite to the blade 35.

[0037] In this embodiment, the vertical bars 60 and 65 are divisible so that their vertical length can be changed in multiple stages. Specifically, the vertical bars 60 and 65 are provided with multiple vertical bar sections 61 made of hollow or solid elongated rod-shaped members (three are given as examples here). In vertical bar 60, the lowest vertical bar section 61 is connected to a cylindrical seventh connecting cylindrical section 27, and the lower end of the seventh connecting cylindrical section 27 is connected to the third connecting cylindrical section 23 described above. In vertical bar 65, the lowest vertical bar section 61 is connected to a cylindrical seventh connecting cylindrical section 27, and the lower end of the seventh connecting cylindrical section 27 is connected to the fifth connecting cylindrical section 25 described above. In each of the vertical bars 60 and 65, the upper end of each vertical bar section 61 is connected to a cylindrical eighth connecting cylindrical section 28, and if there is a vertical bar section 61 above the eighth connecting cylindrical section 28, the upper vertical bar section 61 and the lower vertical bar section 61 are connected by the eighth connecting cylindrical section 28.

[0038] The third connecting cylindrical portion 23 and the fourth connecting cylindrical portion 24 are sized to fit into the seventh connecting cylindrical portion 27, and are fixed together by bolts or pins (not shown) that pass through them while inserted into the seventh connecting cylindrical portion 27. The vertical bar portion 61 is sized to fit into the seventh connecting cylindrical portion 27 and the eighth connecting cylindrical portion 28, and the upper or lower end of the vertical bar portion 61 is fixed together by bolts or pins (not shown) that pass through them while inserted into the seventh connecting cylindrical portion 27 or the eighth connecting cylindrical portion 28, respectively.

[0039] The vertical lengths of the vertical bars 60 and 65 can be changed in multiple stages by increasing or decreasing the number of vertical bar sections 61 to which they are connected.

[0040] From the eighth connecting cylindrical portion 28 of the vertical bar 60, a cylindrical ninth connecting cylindrical portion 29 protrudes toward the vertical bar 65 (towards the front). On the other hand, from the eighth connecting cylindrical portion 28 of the vertical bar 65, a cylindrical ninth connecting cylindrical portion 29 protrudes toward the vertical bar 60 (towards the rear).

[0041] The grass-collecting horizontal bar 70 is a long, rod-shaped, hollow or solid member that extends in the front-to-back direction, positioned above the main body 10 to bridge the vertical bars 60 and 65. In this embodiment, both ends of the grass-collecting horizontal bar 70 are inserted into the ninth connecting cylindrical section 29, which is provided at the same height on each of the vertical bars 60 and 65, and are fixed together by bolts or pins (not shown) that pass through both. The front-to-back direction in which the grass-collecting horizontal bar 70 extends intersects with the rotation direction of the movable arm 91. As the movable arm 91 rotates, the cut grass is pushed by the grass-collecting horizontal bar 70 and collected.

[0042] The anti-tipping horizontal bar 75 is for preventing the grass pushed by the grass-collecting horizontal bar 70 from falling over in the front-to-back direction, and is a long rod-shaped member that extends from the vertical bars 60 and 65 on both sides in the width direction (i.e., the tangential direction in the rotation of the movable arm 91). In this embodiment, the anti-tipping horizontal bar 75 is fixed to the eighth connecting cylindrical portion 28 and the seventh connecting cylindrical portion 27 of the vertical bars 60 and 65, respectively.

[0043] The downward extension 80 is for preventing the blade 35 from contacting the ground, and is detachably attached to the tip of the main body 10, extending below the blade 35. In this embodiment, the downward extension 80 comprises a long, rod-shaped, hollow or solid support member 81 extending in the vertical direction, and a skid 82 attached to the lower end of the support member 81. The skid 82 is a flat plate-shaped member that is long in the width direction, and both ends in the width direction are formed to curve upward. The support member 81 is inserted into the cylindrical sixth connecting cylinder 26 and fixed by bolts or pins (not shown) that pass through both of them. By changing the fixing position of the support member 81 to the sixth connecting cylinder 26, the protrusion height of the skid 82 from the main body 10 can be changed. The skid 82 can be replaced with a swivel tire 83. By having the skid 82 or swivel tire 83 at the lower end of the support member 81, the blade 35, which is held at a height that does not contact the ground, can be moved stably along the ground.

[0044] Next, we will explain how to use the grass trimmer 1. Before starting the grass trimming work, first decide whether or not to attach the vertical bars 60, 65, the grass collection horizontal bar 70, the fall prevention horizontal bar 75, and the downward extension 80 to the grass trimmer 1. When trimming grass and collecting it at the same time, attach the vertical bars 60, 65, the grass collection horizontal bar 70, and the fall prevention horizontal bar 75. Also, when trimming grass, attach the downward extension 80 to prevent the blade 35 from touching the ground. When trimming grass and not using the grass collection horizontal bar 70, etc., remove the vertical bars 60, 65, the grass collection horizontal bar 70, the fall prevention horizontal bar 75, and the downward extension 80, such as when pruning branches or hedges. It is also possible to perform grass trimming using only the main body 10 attached to the attachment 40 without using these parts.

[0045] Next, the grass trimmer 1 is attached to the movable arm 91. Furthermore, the rotation angle of the protruding part 51 of the connection part 50 relative to the insertion part 53 of the attachment 40 is adjusted. For example, when performing grass cutting work on horizontal ground, and the blade 35 is to be parallel to the horizontal plane, the angle is adjusted as shown in Figure 4(a) to achieve a horizontal cutting state as shown in Figure 5. Also, when performing grass cutting work on a slope, and the blade 35 is to be tilted 45° relative to the horizontal plane, the angle is adjusted as shown in Figure 4(b) to achieve a diagonal cutting state as shown in Figure 6. Alternatively, when performing branch trimming or pruning work, and the blade 35 is to be parallel to the vertical plane, the angle is adjusted as shown in Figure 4(c) to achieve a vertical cutting state. The procedure for attaching and detaching the grass collection horizontal bar 70, etc., and the procedure for attaching the grass trimmer 1 to the movable arm 91 may be reversed.

[0046] Next, we move on to the actual work. Here, we will describe grass cutting work performed on level ground in a horizontal cutting state as shown in Figure 5. In this case, vertical bars 60, 65, a horizontal bar for collecting grass 70, a horizontal bar for preventing tipping over 75, and a downward extension 80 are attached to the main body 10. The number of vertical bar sections 61 that make up each of the vertical bars 60, 65 is set according to the height of the grass to be cut. In this state, first, the worker gets on the hydraulic excavator and moves the cylinder rod 99 of the hydraulic cylinder 98 back and forth, so that the attachment 40 and the main body 10 are both rotated around the axis of the joint 95a of the link mechanism 93, so that the blade 35 is parallel to the horizontal plane. Next, the movable arm 91 is mechanically operated to bring the sled 82 into contact with the ground or move it close to the ground. Then, the movable arm 91 is rotated to cut the grass growing on the ground with multiple blades 35. At this time, the horizontal grass-collecting bars 70, positioned according to the height of the grass, catch the cut grass without letting it fall to the ground and push it in the direction of rotation. In addition, the anti-falling horizontal bars 75 catch the grass being pushed by the horizontal grass-collecting bars 70 so that it does not fall in the front-back direction. Then, the rotation direction of the movable arm 91 is changed from one direction to another. At this time, the grass that has been pushed by the horizontal grass-collecting bars 70 is placed on the ground at the point where the rotation direction is changed. By repeating these "rotation" and "change of rotation direction" operations while moving the hydraulic excavator back and forth and left and right as appropriate, grass cutting is performed. The cut grass is then collected at the point where the rotation direction of the movable arm 91 is changed, that is, at both ends in the rotation direction.

[0047] The above describes grass cutting work on level ground. In this embodiment, grass cutting work can be performed not only on level ground but also on sloped surfaces. There are two ways to tilt the angle of the blade 35 with respect to the horizontal plane. The first method is to use the link mechanism 93. In this method, by moving the cylinder rod 99 forward and backward to operate the link mechanism 93, the attachment 40 and the main body 10 are rotated together around the axis of the joint 95a, thereby tilting the angle of the blade 35 with respect to the horizontal plane. This method is effective when the ground to be cut is sloped in the front-to-back direction as viewed from the driver's seat of the hydraulic excavator.

[0048] The second method involves using the angle adjustment mechanism 57. In this method, by changing the angle of the protruding part 51 relative to the insertion part 53, the angle of the main body part 10 relative to the attachment 40 can be changed, and the angle of the blade 35 relative to the horizontal plane can be tilted by 45° as shown in Figure 6. This method is effective when the ground to be mowed is sloped to the left or right relative to the ground on which the hydraulic excavator is positioned.

[0049] As described above, in the brush cutter 1 of this embodiment, the main body 10 is attached to an attachment 40 which is mounted on the movable arm 91 of a hydraulic excavator. A motor 30 supported by the main body 10 rotates the blade 35. As a result, the operator does not have to lift the handle with their own strength to operate it as with a conventional brush cutter, but can cut grass and trees by riding on the hydraulic excavator and mechanically operating the movable arm 91 using the blade 35. Therefore, the burden of labor on the operator is reduced.

[0050] Furthermore, using mechanical power as in this configuration makes it easy to use relatively large blades 35 that would be difficult to lift and maintain with human strength, and to use multiple such blades 35. As a result, compared to conventional brush cutters, the area that can be cut with a single rotation can be increased, allowing for more efficient cutting of grass and trees.

[0051] Furthermore, since the worker performs the work in the driver's seat of the vehicle equipped with the movable arm 91, which is away from the blade 35, the risk of flying stones hitting the worker is reduced, thus increasing safety. Also, even when mowing vegetation on a slope, by extending the movable arm 91, the vehicle itself can be positioned stably on flat ground while mowing the vegetation.

[0052] In this embodiment, the main body 10 and the attachment 40 are connected by a connecting part 50. The connecting part 50 includes a protruding part 51, one end of which is fixed to the main body 10 and protruding from the main body 10; an insertion part 53 provided on the attachment 40 into which the protruding part 51 is inserted; and an angle adjustment mechanism 57 for adjusting the rotation angle of the protruding part 51 relative to the insertion part 53. By rotating the protruding part 51 around the central axis P and changing the rotation angle of the protruding part 51 relative to the insertion part 53, the angle of the main body 10 relative to the attachment 40 can be changed. Therefore, by tilting the blade 35 to match the slope of the ground, grass cutting work on slopes becomes easier. In addition, the degree of freedom of the posture of the blade 35 when performing pruning or branch trimming work is increased, making those tasks easier.

[0053] Furthermore, in this embodiment, by moving the cylinder rod 99 of the hydraulic cylinder 98 forward and backward, the attachment 40 and the main body 10 are rotated together around the axis of the joint 95a of the link mechanism 93, thereby tilting the angle of the blade 35 with respect to the horizontal plane. As a result, by tilting the blade 35 with respect to the horizontal plane to match the slope of the ground, grass cutting work on slopes becomes easier.

[0054] Furthermore, in this embodiment, a horizontal bar 70 for collecting grass, extending in a direction intersecting the rotation direction of the movable arm 91 (front-to-back direction), is attached to the main body 10. As a result, while the movable arm 91 is rotating in one direction, the cut grass is pushed and moved by the horizontal bar 70. When the rotation direction of the movable arm 91 is changed from one direction to the other, the grass that has been pushed by the horizontal bar 70 is placed on the ground at the point where the rotation direction is changed. Therefore, since the cut grass can be gathered at both ends in the rotation direction of the movable arm 91 while cutting the grass, the amount of manual grass collection work can be greatly reduced, and the labor burden is further reduced.

[0055] In this embodiment, long, rod-shaped vertical bars 60 and 65 are attached to the main body 10. Each of the vertical bars 60 and 65 is a segmented type consisting of multiple vertical bar sections 61, allowing its vertical length to be changed in multiple stages. The grass-collecting horizontal bar 70 is attached to a connecting section (eighth connecting cylinder section 28) for connecting each vertical bar section 61 vertically, via a ninth connecting cylinder section 29. This allows the grass-collecting horizontal bar 70 to be positioned at a height corresponding to the height of the grass.

[0056] Furthermore, in this embodiment, elongated rod-shaped anti-tipping horizontal bars 75 are provided, extending from the vertical bars 60 and 65 to both sides in the width direction. This prevents the grass, which is pushed in the rotational direction by the grass-collecting horizontal bar 70, from falling over in the front-to-back direction, thanks to the anti-tipping horizontal bars 75.

[0057] Furthermore, in this embodiment, the vertical bars 60 and 65, the grass-collecting horizontal bar 70, and the anti-tipping horizontal bar 75 are detachable from the main body 10. The vertical bars 60 and 65 are divisible. This allows these parts to be removed from the main body 10 when they are not needed. Also, by removing these parts, the entire grass trimmer 1 can be transported and stored in a less bulky manner.

[0058] Furthermore, in this embodiment, a tip plate 16 is provided at the tip of the main body 10, extending forward of the blade 35. This ensures that even if there is an obstacle such as a wall in front of the brush cutter 1, the tip plate 16 will come into contact with the obstacle before the blade 35 does. Therefore, it is possible to prevent the blade 35 from coming into contact with the obstacle in front and damaging the obstacle or the blade 35 itself.

[0059] Furthermore, in this embodiment, a downward extension portion 80 is provided that extends downward from the main body 10, below the blade 35. As a result, the downward extension portion 80 contacts the ground before the blade 35 contacts the ground. Therefore, it is possible to prevent the blade 35 from contacting the ground. In addition, it is possible to prevent flying stones caused by the blade 35 contacting stones on the ground. Moreover, by rotating the movable arm 91 while keeping the downward extension portion 80 in contact with the ground and performing grass cutting, the grass cutting height can be made uniform.

[0060] Furthermore, in this embodiment, the protrusion height of the downward extension portion 80 from the main body portion 10 can be changed. This allows the height of the blade 35 from the ground to be appropriately adjusted according to the size of obstacles such as stones on the ground, so that the blade 35 does not come into contact with the obstacle.

[0061] Furthermore, in this embodiment, the motor fixing plate 14 on which the motor 30 is mounted and through which the output shaft 31 passes is divided and provided for each motor 30. Therefore, the main body 10 can be made lighter.

[0062] Although preferred embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various improvements and design changes are possible without departing from the spirit of the present invention, as shown below.

[0063] For example, in the above embodiment, the grass trimmer 1 is shown attached to the movable arm 91 of a hydraulic excavator (hydraulic excavator), but it may also be attached to the movable arm of an electric excavator, or to a movable arm of another vehicle such as a truck. Also, in the above embodiment, the projection 51 is shown fixed to the main body 10 and the insertion part 53 is provided on the attachment 40, but the projection may be fixed to the attachment and the insertion part may be provided on the main body. Furthermore, in the above embodiment, the projection 51 was a cylindrical member, but it may also be a columnar member with a polygonal outer shape in the cross-section perpendicular to the central axis, with the insertion direction into the insertion part 53 as the central axis.

[0064] Furthermore, in the above embodiment, the grass-collecting horizontal bar 70 and the anti-tipping horizontal bar 75 were fixed to connecting parts (eighth connecting cylindrical part 28, seventh connecting cylindrical part 27) that connect multiple vertical bar parts 61, but they may also be fixed directly to the vertical bar parts 61. Also, in the above embodiment, two vertically adjacent vertical bar parts 61 were shown as being joined by inserting the ends of each vertical bar part 61 into a cylindrical connecting part (eighth connecting cylindrical part 28) and then joining them with a bolt or pin that passes through both, but male threads may be formed on both vertical bar parts 61 and connected with nuts, or a male thread formed on one may be screwed into a female thread formed on the other for connection. Also, in the above embodiment, the vertical bars 60 and 65 were of a segmented type consisting of multiple vertical bar parts 61, but they may also be composed of a single long rod-shaped member. Furthermore, in the above embodiments, examples were given of fixing the connecting cylinders together (first connecting cylinder 21 and third connecting cylinder 23, second connecting cylinder 22 and fourth connecting cylinder 24, third connecting cylinder 23 and seventh connecting cylinder 27, fifth connecting cylinder 25 and seventh connecting cylinder 27) by inserting one connecting cylinder into the other and then fixing them together with a bolt or pin that passes through both. Also, examples were given of fixing the connecting cylinders to the long rod-shaped members (seventh connecting cylinder 27 and vertical bar 61, eighth connecting cylinder 28 and vertical bar 61, ninth connecting cylinder 29 and grass-collecting horizontal bar 70) by inserting the long rod-shaped members into the connecting cylinders and then fixing them together with a bolt or pin that passes through both. However, the invention is not limited to these examples, and when one member is inserted into the interior of the other member, a projection such as a claw provided on one of them may engage with a recess or the like provided on the other, thereby fixing the two together.

[0065] Furthermore, in the above embodiment, the multiple blades 35 are arranged such that adjacent blades 35 partially overlap when viewed from directly above, and in order to avoid interference between them, the vertical positions of adjacent blades 35 are made different. However, the invention is not limited to this, and the multiple blades may be arranged so that adjacent blades do not overlap when viewed from directly above, and the vertical positions of these blades may be the same.

[0066] Furthermore, the above embodiment illustrates a case where a hydraulic hose is connected to each of the multiple motors 30, and multiple blades 35 are rotationally driven by separate motors 30. However, it is not limited to this, and a configuration may be used in which power is supplied to only one motor, the blade is rotated by its output shaft, and that rotation is transmitted to the rotation shafts of the other blades via a transmission mechanism such as a pulley and a belt to drive them. [Explanation of symbols]

[0067] 1. Grass trimmer 10 Main body 30 motors 35 blades 40 Attachments 51 Protrusion 53 Insertion part 57 Angle adjustment mechanism 70 horizontal bar for grass collection 91 Movable Arm

Claims

1. A grass trimmer that is moved by a movable arm attached to the vehicle, An attachment to be attached to the tip of the movable arm, The main body is detachably attached to the aforementioned attachment, The motor is supported by the main body, The blade rotates due to the driving force of the motor and A grass trimmer characterized by being equipped with the following.

2. A protruding portion having one end fixed to and protruding from either the attachment or the main body, An insertion portion is provided on the other side of the attachment and the main body, into which the protruding portion is inserted, An angle adjustment mechanism that varies the angle of the main body relative to the attachment by the rotation angle of the protruding part around an axis parallel to the insertion direction of the insertion part, It further comprises The grass trimmer according to feature 1.

3. In the main body, the end closest to the attachment is referred to as the base end, and the end opposite to the base end is referred to as the tip. The main body further comprises a horizontal bar for collecting grass, which is supported by the main body and extends in the front-rear direction from the base end to the tip. A grass trimmer according to claim 1 or 2.

Images