JP7590772B2 - Grass cutting equipment - Google Patents

Description

The present invention relates to a grass cutting device that is attached to a traveling body of a tractor or the like. In particular, the present invention relates to a grass cutting device that is arranged at a distance to the side of the traveling body.

Patent Document 1 discloses an invention for a working machine in which a working unit is attached to a traveling body and this working unit is positioned at a remote location using a bending means consisting of multiple booms to perform work. In this invention, the grass cutting work state and the storage state are realized by bending the grass cutting machine body, which is the working unit, using multiple arms, which are the bending means. In addition, the working unit is attached to the bending means via a swinging mechanism provided at the tip of the arm, so that the working unit in the grass cutting work state follows the unevenness of the ground. When in the storage state, the mechanism locks the grass cutting machine body, which is the working unit, with a locking part provided on the arm.

JP 2010-200669 A

However, to lock the grass cutter body (working part) in the stored state, multiple arms must be rotated in the correct order, which can be difficult for operators to understand. In addition, because the working part is attached to the arm via a swinging mechanism, if the working part is not correctly locked to the locking part in the stored state, the working part may swing around during transportation.

Therefore, the present invention was made with the above problem in mind, and aims to provide a grass cutting device that is easy to operate and can regulate the swinging of the working part when stored.

The gist of one aspect of the present invention to achieve the objective is that it is a grass cutting device that includes a working unit that can be rotated by a fulcrum shaft, a rod that is connected between the vicinity of the fulcrum shaft and the working unit and is arranged so that it can move relative to a holding part provided on the working unit, and a regulating piece that is rotatably attached to the working unit and regulates the relative movement of the rod to the holding part by rotating it, thereby regulating the rotation of the working unit.

This invention provides a grass cutting device that is simple to operate and can regulate the swinging of the working part when stored.

FIG. 2 is a rear view of the grass mowing device according to the embodiment in an operational state, as viewed from the rear in the traveling direction. FIG. 2 is a side view of the working state of the grass mowing device according to the embodiment, viewed from the left side in the traveling direction toward the right side in the traveling direction. FIG. 2 is a plan view of the grass mowing device according to the embodiment in a working state, showing a state in which the working unit is located in a first working area. 1 is a rear view showing the grass mowing device according to the embodiment in the middle of transitioning from an operating state to a stored state. FIG. 11 is a rear view showing the grass mowing device according to the embodiment in a stored state with the working unit turned upside down. FIG. 1 shows an example of a grass cutting device attached to a boom device provided on a traveling body, and is a rear view showing the working state. 1 shows an example of a grass cutting device attached to a boom device provided on a traveling body, and is a rear view of the stored state.

An embodiment of the present invention will be described with reference to the drawings. In the description, the right side in Fig. 1 and Figs. 4 to 7 is expressed as the right side in the direction of travel, and the left side is expressed as the left side in the direction of travel. In addition, the left side in Figs. 2 and 3 is expressed as the forward side in the direction of travel, and the right side is expressed as the rear side in the direction of travel. In addition, unless otherwise specified in the description, the upward direction refers to the direction away from the ground side, which is the work surface, and the downward direction refers to the direction approaching the ground side along the direction of gravity. In the description of the drawings, the same or similar parts are given the same or similar symbols, and their description may be omitted. In addition, the drawings used in the description are schematic, and the relationship between the dimensions of each part may differ from the actual ones. In addition, the technical idea of the present invention can be variously modified within the technical scope defined by the claims described in the claims.

As shown in Fig. 6 and Fig. 7, the grass cutting device 1 is attached to a traveling machine body T consisting of a tractor or the like by a boom device A, which is an attachment frame consisting of a single or multiple booms A2, A3. Fig. 6 and Fig. 7 show an example in which the grass cutting device 1 is attached to a boom device A that can be freely extended or bent by a cylinder or the like of the boom device A attached to the rear of the traveling machine body T. As shown in Fig. 6, the booms A2, A3 of the boom device A can be rotated up and down around the boom rotation shaft as a fulcrum, so that the grass cutting device 1 can be placed in a working state in which it is positioned at any location away from the traveling machine body T, and work can be performed. Also, as shown in Fig. 7, the booms A2, A3 of the boom device A can be rotated around each boom rotation shaft as a fulcrum, so that the grass cutting device 1 and the boom device A can be folded and stored so that they are almost contained within the overall width of the traveling machine body T. When the grass cutting device 1 is stored, the working unit 51 can be turned upside down and placed on the boom device A, allowing it to be easily transported by the traveling body T without protruding from the side of the traveling body T.

The grass cutting device 1 shown in Figs. 1 to 3 is attached to the tip of the boom device A by the attachment part 10. A frame 2 extending forward in the direction of travel is attached to the attachment part 10. A work arm 50 is arranged below the frame 2, which can rotate horizontally and has a working part 51 attached to the tip of the rotating radial direction. The work arm 51 has multiple cutting blades 511 that rotate horizontally, and the grass on the work surface is cut by rotating the cutting blades 511. Since the work arm 50 can rotate horizontally, the work arm 50 can pass through an obstacle moving relatively from the front side while rotating backward in the horizontal direction. Since the work arm 50 is arranged so that the work arm 51 protrudes from the attachment part 10 by the frame 2, the boom device A can work in a complicated and intricate place where there is an obstacle covering the upper part of the work arm 51 without colliding with the obstacle above.

The mounting part 10 can be fixed integrally to the boom device A by fitting it to the tip of the boom device A, and can be released from the boom device A by releasing this fixation. In other words, the grass cutting device 1 can be freely attached and detached from the boom device A. In the embodiment, the tip of the boom device A is fixed to the top of the mounting part 10, but there is no limitation on the fixed position. In addition, a rolling fulcrum part A1, which is an axis facing forward and backward in the direction of travel, is provided at the tip of the boom device A, and the grass cutting device 1 can be rotated left and right. This rotation operation properly faces the cutting blade 511 of the working part 51 so that it faces the work surface that is inclined left and right. The working part can be formed into a working state with a proper posture. In addition, by rotating the grass cutting device 1 in reverse around the rolling fulcrum part A1 as an axis, the cutting blade 511 can be positioned in a direction that does not face the work surface.

The rear end of the frame 2 is fixed to one end of the mounting part 10, which is on the left side in the traveling direction. In this embodiment, the frame 2 is composed of a first frame 20 that is long forward, and a second frame 30 that is connected to the front end of the first frame 20 by a bending shaft 40 and can rotate horizontally relative to the first frame 20. The first frame 20 is a long member and is arranged so that its long dimension protrudes forward. A holder part 22 is provided at the front end of the first frame 20, and a bending shaft 40, which is a vertical axis, is provided on this holder part 22. The rear end of the second frame 30 is connected to this bending shaft 40 so that it can rotate horizontally.

The second frame 30 is a long member, and is arranged so that its long dimension protrudes forward. In the embodiment, the second frame 30 is arranged so that its long dimension is inclined relative to the first frame 20 in a plan view. By providing the second frame 30 with the ability to rotate around the bending axis 40 as a fulcrum, when a load is applied to the second frame 30 due to a collision with an obstacle or the like on the rear side in the traveling direction, the second frame 30 rotates rearward, preventing damage to the frame 2. Note that, in the embodiment, the frame 2 is provided with the first frame 20 and the second frame 30 bendable, but they may be integrated and unbendable. Furthermore, the second frame 30 does not need to be inclined relative to the first frame 20.

The fulcrum shaft 31 is provided below the front end of the second frame 30, which is the front end of the frame 2. The fulcrum shaft 31 is provided near the middle of the fulcrum tube 71, which protrudes downward from the front end of the second frame 30. The fulcrum tube 71 is a member for supporting the support shaft 72 of the skid 73. The fulcrum tube 71, skid 73, and support shaft 72 will be described later.

The fulcrum shaft 31 is a vertical shaft that is in the up-down direction, and is provided below the front end side of the frame 2. In the case of this embodiment, it is located behind the middle part of the fulcrum tube 71 that hangs down from the front end part of the frame 2. One end side of the working arm 50 is attached to the fulcrum shaft 31. The working arm 50 can freely rotate in the horizontal direction around the fulcrum shaft 31.

A working unit 51 is provided on the other end of the working arm 50, which is the side radially away from the axis of the fulcrum shaft 31. The working unit 51 is a working part capable of cutting grass growing on the ground. The working unit 51 includes a cutting blade 511, a motor 512, and a cover member 513. The motor 512 is provided on the other end of the working arm 50, and drives the cutting blade 511 disposed below it to rotate. There are multiple cutting blades 511, which are freely rotatable in the horizontal direction around the motor 512 as an axis and rotate by receiving the rotational power of the motor 511. The rotating cutting blades 511 can cut grass present on the work surface.

The working arm 50 is provided with a cover member 513. The cover member 513 is a teardrop-shaped member in a plan view, with the teardrop-shaped protrusion facing the fulcrum shaft 31. The cover member 513 is positioned above the cutting blade 511 to prevent objects such as grass clippings scattered by the cutting blade 511 from scattering upward. In the case of this embodiment, the other end of the working arm 50 is positioned rearward of the fulcrum shaft 31 in a plan view, and the motor 512 that serves as the rotation drive shaft for the cutting blade 511 is positioned to the side of the frame 2.

The working arm 50 rotates horizontally around the fulcrum shaft 31, so that the working unit 51 shown in FIG. 3 can be positioned in either a first working area B on the left side of the traveling direction, or a second working area C on the right side of the traveling direction, which are divided along the front-to-rear longitudinal direction passing through the fulcrum shaft 31. The working unit 51 shown by the solid line in FIG. 3 shows the state in which it is positioned in the first working area B, and the working unit 51 shown by the two-dot chain line shows the state in which it is positioned in the second working area C. Grass-cutting work is performed by the working unit 51 positioned in each area.

The fulcrum shaft 31 is provided with a switching piece 55 that is separate from the working arm 50 and can rotate around the same axis as the working arm 50. The switching piece 55 is provided separately from the working arm 50 and rotates around the fulcrum shaft 31 independently of the working arm 50. An arc-shaped long hole 551 is provided at one end of the switching piece 55. In the embodiment, the long hole 551 is provided on the first working area B side, which is the one end side. The rotation restricting body 52 is passed through the long hole 551. The center of the arc of the arc-shaped long hole 551 is provided coaxially with the fulcrum shaft 31, so the switching piece 55 can freely rotate within the long hole 551.

The rotation restricting body 52 is a rod-shaped member that is long in the vertical direction and is placed near the fulcrum shaft 31 and passes through the long hole 551. The rotation restricting body 52 is fixed in position relative to the fulcrum shaft 31. Furthermore, the rotation restricting body 52 comes into contact with the work frame 51, thereby restricting the rotation angle of the work frame 51 in the forward direction in each of the first work area B and the second work area C.

A rod-shaped guide rod 57 is rotatably arranged at the other end of the switching piece 55. The guide rod 57 is arranged to span between a guide rod fulcrum 571 provided at the other end of the switching piece 55 and a guide rod holding part 572, which is a holding part provided on the other end side of the working arm 50 and the upper part of the cover member 513. The guide rod 57 spans the vicinity of the fulcrum shaft 31 and the upper part of the cover member 513 arranged on the working part 51. The axial direction of the guide rod 57 in plan view is slightly inclined with respect to the longitudinal direction of the working arm 50. The guide rod 57 is arranged to be able to move relative to the guide rod holding part 572 by sliding inside the guide rod holding part 572, which is a holding part.

A biasing body 56 is arranged on the outer periphery of the guide rod 57 to bias the working arm 50 towards either the first working area B or the second working area C. In this embodiment, a compression spring is used as the biasing body 56. The guide rod 57 serves to guide the biasing body 56 so that it does not shift. A biasing body regulating portion 573 is fixed to the guide rod fulcrum portion 571 side of the guide rod 57. The biasing body 56 biases the working arm 50 by expanding and contracting between the biasing body regulating portion 573 and the guide rod holding portion 572. The biasing body 56 biases the working unit 51 and the working arm 50 forward in the direction of travel.

The action of the switching piece 55 will now be described. The switching piece 55 rotates around the fulcrum shaft 31, changing the biasing direction of the biasing body 56 and pushing the working arm 50 towards either the first working area B or the second working area C. The working arm 50 located in the first working area B or the second working area C is pushed by the biasing body 56 and rotates until the working arm 50 comes into contact with the rotation restricting body 52, and the rotation is restricted at the position where the working arm 50 comes into contact with the rotation restricting body 52.

3 shows the state in which the working arm 50 and working unit 51 are located in the first working area B with solid lines. The arrow extending in an arc in FIG. 3 indicates the first rotation direction D and the second pivot direction E, which are the rotation directions of the working arm 50, working unit 51, and switching piece 55 around the fulcrum shaft 31. When the working unit 51 is located in the first working area B, the guide rod fulcrum part 571 of the switching piece 55, which is located behind the fulcrum shaft 31 and on the second working area C side, is pushed by the biasing body 56 to rotate the switching piece 55 in the second pivot direction E, which is a left rotation direction in a plan view. The switching piece 55 rotates in the second pivot direction E until the pivot restricting body 52 contacts one end of the long hole 551, and after the contact, the pivoting of the switching piece 55 is restricted. The biasing body 56 continues to bias the switching piece 55, whose rotation is restricted, in the second rotation direction E, and by pressing the guide rod holding portion 572, rotates the working arm 50 in the first rotation direction D, which is a right rotation direction in a plan view, until the working arm 50 contacts the rotation restricting body 52. In other words, the working arm 50 and the working unit 51 are biased forward in the direction of travel in the first working area B. In the first working area B, the position where the working arm 50 contacts the rotation restricting body 52 is called the return position in the first working area B.

In this way, the working unit 51 located in the first working area B can be deployed away from the side of the frame 2 by being biased in the first pivot direction D by the switching piece 55 and the biasing body 56, and can be positioned at the return position in the first working area B. Also, when the working unit 51 and the working arm 50 are pushed backward by an external force, they pivot in the second pivot direction E in accordance with the external force. At this time, the distance between the guide rod holding part 572 and the biasing body regulating part 573 is shortened, and the biasing body 56 is compressed. The compressed biasing body 56 is in a state in which the repulsive force is increased. Since the guide rod fulcrum part 571 is located on the second working area C side of the line segment connecting the fulcrum shaft 31 and the guide rod holding part 572, when the external force is removed, the working arm 50, which has been biased by the biasing body 56, returns to the return position in the first working area B. In this case, the external force in actual work refers to a pressing force from an obstacle such as a pillar that is higher than the working unit, and when this obstacle collides with the working unit, the working arm 50 and the working unit 51 rotate backward within the first working area B. Then, when the external force is removed, the working arm 50 and the working unit 51 return to their return positions.

As shown by the two-dot chain line in FIG. 3, the working arm 50 and the working unit 51 can be switched from the first working area B to the second working area C by the switching piece 55 and the biasing body 56. When switching, the working arm 50 or the working unit 51 located in the first working area B is rotated toward the second rotation direction E. If the working arm 50 continues to rotate in the second rotation direction E, the working arm 50 and the working unit 51 will eventually be located on the second working area C side. If the working arm 50 continues to rotate further, the fulcrum shaft 31, the guide rod fulcrum part 571, and the guide rod holding part 572 will be arranged on a straight line in a plan view. If the working arm 50 continues to rotate further, the guide rod fulcrum part 571 will be located on the first working area B side of the virtual line segment connecting the fulcrum shaft 31 and the guide rod holding part 572, so that the switching piece 55 will rotate in the first rotation direction D by the biasing body 56.

The switching piece 55 rotates until the rotation restricting body 52 contacts the other end of the long hole 551, and then the rotation in the first rotation direction D is restricted by the rotation restricting body 52. The working arm 50 and working part 51 are then positioned in the second working area C, and are urged by the biasing body 56 toward the forward direction of travel, which is the second rotation direction E. The biasing body 56 continues to urge the switching piece 55, whose rotation is restricted, in the first rotation direction D, and rotates the working arm 50 in the second rotation direction E, which is a left rotation direction in a plan view, until the working arm 50 contacts the rotation restricting body 52. This position is called the return position in the second working area C.

The working unit 51 located in the second working area C can be urged in the second pivot direction E by the switching piece 55 and the biasing body 56, and deployed away from the side of the frame 2 to be located in a return position in the second working area C. Furthermore, when the working unit 51 and working arm 50 are pushed backward by an external force such as an obstacle, they pivot in the first pivot direction D in accordance with the external force, but return to their return position in the second working area C when the external force is removed. The procedure for moving the working unit 51 located in the second working area C to the first working area B is similar to that described above, so a description of this will be omitted.

By using the switching piece 55, one working unit 51 can be deployed to either the first working area B or the second working area C, and the direction of the biasing force of the biasing body 56 can be changed so that it faces the return position corresponding to each deployment position.

The working unit 51 shown by solid lines in FIG. 3 is located in the first working area B and in the return position. In this return position, the guide rod 57 protrudes rearward minimally from the guide rod holding part 572. As shown in FIG. 3, when the working unit 51 is located in the first working area B, the guide rod fulcrum part 571 is provided on the second working area C side. The guide rod holding part 572 is located in the first working area B and holds the guide rod 57 slidably in the axial direction, and does not impede the rotational movement of the working arm 50. Similarly, when the working unit 51 is located in the second working area C and in the return position, the guide rod 57 protrudes rearward minimally from the guide rod holding part 572.

As the working arm 50 and working unit 51, which are in the return position in the first working area B or the second working area C, gradually rotate backward, the end 57a of the guide rod 57 increases the amount of protrusion backward relative to the guide rod holding part 572. In other words, the guide rod 57 slides and moves relative to the guide rod holding part 572 as the working arm 50 and working unit 51 rotate. The amount of protrusion of the end 57a of the guide rod 57 relative to the guide rod holding part 572 is maximum when the working unit 51 reaches the rearmost end as it rotates.

A restricting piece 61 is provided above the cover member 513 and behind the guide rod holding portion 572. The restricting piece 61 is a rectangular plate member that can be rotated up and down by a restricting piece pivot shaft 62, which is a horizontal shaft provided on one end. The restricting piece pivot shaft 62 is provided parallel to the working arm 50, and the guide rod 57, which moves axially relative to the guide rod holding portion 572, is provided so that it can enter the pivot area of the restricting piece 61.

The regulating piece pivot shaft 62 is supported by the holder part 63. The holder part 63 is a member bent into a U-shape, with the open side of the U-shape facing downward, and is located at the top of the working arm 50 and at the tip in the radial direction centered on the fulcrum shaft 31. The holder part 63 regulates the upward rotation of the regulating piece 61 in the working state by a locking surface 63a provided on the top of the holder part 63. The downward rotation of the regulating piece 61 is regulated by abutting against the working arm 50 or the cover member 513. In other words, the regulating piece 61 is freely rotatable between the locking surface 63a of the holder part 63 and the working arm 50 or the cover member 513.

1 and 2, when the cutting blade 511 of the working unit 51 is positioned to face the ground and the working unit 51 is in the return position, the restricting piece 61 is in a state of being rotated downward by its own weight. The downward rotation of the restricting piece 61 is restricted by the working arm 50 or the cover member 513. At this time, the guide rod 57 is in a state where it can enter the rotation area of the restricting piece 61. In the case of the embodiment, the guide rod 57 is movable above the guide rod 57 whose downward rotation is restricted. Therefore, the guide rod 57 can move relative to the holder part 63 in the axial direction of the guide rod 57 in conjunction with the working unit 51 which rotates around the fulcrum shaft 31. Therefore, the working unit 51 can rotate backward from the return position, and the grass cutting work involving rotation around the fulcrum shaft 31 is not hindered.

The regulating piece pivot shaft 62 is located between the guide rod 57 and the working arm 50. Alternatively, it can be said that the regulating piece pivot shaft 62 is located between the guide rod 57 and the cover member 513. FIG. 4 shows the working section 51 rotated by the rolling fulcrum part A1 provided on the boom device A in the working state, and standing so that the rotation axis of the cutting blade 511 is horizontal. At this time, the regulating piece 61 rotates by itself by its own weight around the regulating piece pivot shaft 62 as a fulcrum and hangs down, and the other end 61a side of the regulating piece 61 moves away from the working arm 50 or the cover member 513. As shown in FIG. 4, the other end 61a side of the regulating piece 61 is located directly below the regulating piece pivot shaft 62.

In this state, the guide rod 57 is positioned symmetrically to the cover member 513 with respect to the regulating piece pivot axis 62. Therefore, the guide rod 57 can slide freely relative to the guide rod holding portion 572, and the end portion 57a of the guide rod 57 can protrude from the guide rod holding portion 572 toward the regulating piece 61. In other words, even when the working unit 51 is erected as shown in FIG. 4, the guide rod 57 can enter the pivot area of the regulating piece 61, and the working unit 51 can pivot around the fulcrum axis 31.

Applied to actual mowing work, the mowing surface may be inclined left and right relative to the direction of travel. In such locations, the mowing device 1 is rotated by the rolling fulcrum part A1 so that the cutting blade 511 can be properly aligned with the mowing surface. Even if an obstacle such as a support pole is present in a location with such left and right inclination, the working unit 51 can rotate around the fulcrum shaft 31 when the obstacle collides with it. At this time, the fulcrum shaft 31 is inclined by the rolling fulcrum part A1, so the working unit 51 rotates in a direction that follows the inclination of the work surface.

When the working section 51 is rotated from the state shown in FIG. 4 around the rolling fulcrum A1 and the boom of the boom device A is rotated, the cutting blade 511 is further inverted so as to face upward, resulting in the state shown in FIG. 5. The other end 61a of the regulating piece 61 rotates by itself by its own weight, with the regulating piece pivot shaft 62 as the fulcrum, until it is engaged with the engaging surface 61a of the holder section 61. The other end 61a of the regulating piece 61 engaged with the engaging surface 61a shown in FIG. 5 is further away from the working arm 50 or the cover member 513 compared to the position of the regulating piece 61 shown in FIG. 4. As shown in FIG. 5, the other end 61a of the regulating piece 61 is positioned below the regulating piece pivot shaft 62. The boom device shown in FIG. 5 shows the booms A2 and A3 in a folded, stored state.

As shown in FIG. 5, when the working unit 51 is turned upside down, the guide rod 57 is located below the regulating piece pivot axis 62 and above the other end 61a of the regulating piece 61. Therefore, the regulating piece 61 is located on the trajectory of the guide rod 57 sliding on the guide rod holding part 572, and the guide rod 57 cannot enter the rotation area of the regulating piece 61. Even if the end 57a of the guide rod 57, which is the rod end, moves relative to the guide rod holding part 572 and tries to protrude from the guide rod holding part 572, the movement is restricted by the side part 61b of the regulating piece 61 on the guide rod 57 side. Therefore, even if the working unit 51 and the working arm 50 try to rotate from the return position around the fulcrum axis 31, the movement of the guide rod 57 is restricted by the regulating piece 61, and the rotation position of the working unit 51 is fixed in the return position.

When the working unit 51 of the grass cutting device 1 is inverted, the rotation position of the working unit 51 is fixed in the return position, so the relative positional relationship with the frame 2 and the mounting unit 10 does not change. Therefore, the positional relationship of the working unit 51 with the boom device A is also fixed. In the inverted state, the working unit 51 cannot rotate around the rotation axis 31 due to the restricting piece 61, so the working unit 51 will not swing unexpectedly.

In addition, simply by performing the operation of inverting the working unit 51, the restricting piece 61 naturally fixes the rotation of the working unit 51 and the working arm 50 around the fulcrum axis 31. Therefore, the operator does not need to perform any special manual operation to fix the rotation of the working unit 51 and the working arm 50. In addition, since the grass cutting device 1 is inevitably inverted to put it into the stored state, the operator will not forget to fix the working unit 51 and the working arm 50. This allows the operator to concentrate on operating the boom device A, making work easier.

In the case of the embodiment, as shown in FIG. 4, the working unit 51 is configured to be able to rotate around the fulcrum axis 31 even when it is held almost vertically. From this state, the reversal operation is further advanced to restrict the rotation of the working unit 51 around the fulcrum axis 31. Not limited to the above configuration, the angle of the working unit 51 that restricts the movement of the guide rod 57 at the restricting piece 61 can be determined arbitrarily. By adjusting the shape of the restricting piece 61, the position of the restricting piece pivot axis 62, the position of the guide rod 57, etc., the rotation angle of the grass cutting device 1 around the rolling fulcrum A1 at which the restricting piece 61 starts restricting the rotation of the working unit 51 around the fulcrum axis 31 can be adjusted.

In the embodiment, the working unit 51 is provided so as to be horizontally rotatable in two areas, the first working area B and the second working area C, with the fulcrum shaft 31 as the boundary, and is provided so as to be rotatable so as to return to a return position within each area. In addition, in the return position within each area, the amount of protrusion of the end 57a of the guide rod 57 relative to the guide rod holding portion 572 is minimized. In this return position, the restricting piece 61 restricts the protrusion of the guide rod 57 relative to the guide rod holding portion 572, thereby restricting the rotation of the working unit 51 and the working arm 50 and fixing the rotation operation. In the embodiment, the working unit 51 is provided so as to be able to work in two areas, the first working area B and the second working area C, but even in a configuration that has only one of the working areas, the restricting piece 61 can restrict the rotation of the working unit 51 and the working arm 50.

A skid, called a working skid 58, is provided on the radial side of the rotating cutting blade 511. The working skid 58 is a rod-shaped sled member formed from a rod-shaped member, and multiple working skids 58 are provided around the side of the cutting blade 511. In the embodiment described, the working skids 58 are provided at two locations around the side of the cutting blade 511, symmetrical with respect to the longitudinal direction of the working arm 50. In the description, one working skid 58 is referred to as the first working skid 58a, and the other as the second working skid 58b.

The first working section skid 58a and the second working section skid 58b slide along the ground, thereby maintaining the relative height between the cutting blade 511 and the ground. In other words, even if the ground, which is the working surface that moves relatively from the front as the grass cutting work progresses, is uneven, the cutting blade 511 is prevented from coming into contact with the ground.

A bowl-shaped grounding body 59 is provided under the working unit 51. The bowl-shaped grounding body 59 is provided coaxially with the rotation axis of the cutting blade 511. The bowl-shaped grounding body 59 is attached so that it can rotate freely independent of the rotation of the cutting blade, so that even when the bowl-shaped grounding body touches the ground, it remains stationary and prevents the cutting blade 511 from coming into contact with undulating ground surfaces, etc.

The working part skid 58 guides the majority of rough undulations, causing the working part 51 to move up and down, while the bowl-shaped ground contact body 59 captures ground undulations that the working part skid 58 cannot fully guide, causing the working part 51 to move up and down. If there are undulations in the ground approaching below the cutting blade 511 as the mower advances, the bowl-shaped ground contact body 59 comes into contact with the undulations in the ground, pushing up the grass cutting device 1 via the working part 51. The grass cutting device 1 then moves up and down at the rolling fulcrum A1 near the mounting part 10 and the boom device A.

A skid 73 is provided on the lower part of the fulcrum tube 71 that is disposed downward from the front end of the frame 2. The skid 73 is located below the working arm 50 and is a sled-shaped member that is long from front to back and has a curved portion 731 that comes into contact with the ground, which is the working surface. The skid 73 is provided so that its longitudinal direction always faces the direction of travel. The curved portion 731 of the skid 73 makes contact with the working surface and glides across the working surface, preventing the cutting blade 511 of the working part 51 from getting too close to the working surface.

The curved portion 731 is set to be larger than the radius of rotation of the cutting blade 511. In this embodiment, the radius of curvature of the curved portion 731 is 350 mm, and the radius of rotation of the cutting blade 511 is 260 mm. In other words, by setting the dimensional relationship such that the radius of curvature of the curved portion 731 is 1.35 times larger than the radius of rotation of the cutting blade 511, the skid 73 is prevented from getting stuck in small depressions that exist on the work surface. Since the skid 73 does not move up and down sensitively to small depressions, the working part 51 also does not move up and down sensitively on the work surface. In other words, the cutting blade 511 is prevented from coming into contact with small depressions, etc., and damage to the working part 51 is prevented.

The skid 73 is located on the front side of the grass cutting device 1, so it can reach the unevenness before the working part 51, which works as it moves forward, reaches the unevenness. This prevents the working part 51 moving forward from suddenly coming into contact with the unevenness and being damaged. In other words, it is possible to catch the unevenness of the ground before the working part 51. In addition, since the curved radius of the curved part 731 is set to be larger than the rotation radius of the cutting blade 511, it does not react sensitively to small unevenness and can prevent the lower part of the working part 51 from contacting the working surface. Because the curved radius of the curved part 731 is large, the working part 51 does not get stuck in a depression smaller than the rotation radius of the cutting blade 511, so grass cutting work can be continued stably.

The operation of putting the grass cutting device 1 configured as described above into the working state and the stored state using the boom device A will be described with reference to Figures 6 and 7. The grass cutting device 1 attached to the boom device A is placed in a working state by rotating each of the multiple booms A2, A3 around each boom rotation shaft. In the example shown in Figure 6, the grass cutting device 1 is located on the left side of the traveling direction of the traveling body T, and the working unit 51 is located in the first working area B. In this working state, the grass cutting device 1 places the cutting blade 511 facing the working surface and performs grass cutting work as the traveling body T moves forward.

When mowing in an operating state, the ground surface, which is the work surface, may contain pillar-shaped obstacles such as telegraph poles or guardrail posts. Even if an obstacle collides with the front of the working unit 51, the obstacle can be passed relatively to the rear of the mowing device 1 without operating the boom device A by rotating horizontally around the fulcrum shaft 31. After the obstacle has passed, the working unit 51 returns to its return position in the same working area. In conjunction with the rotation of the working unit 51, the end 57a of the guide rod 57 supported by the guide rod fulcrum part 571 slides along the guide rod holding part 572. It is returned to its return position by the biasing body 56 arranged between the guide rod fulcrum part 571 and the guide rod holding part 572.

When changing from the working state shown in FIG. 6 to the stored state shown in FIG. 7, the boom device A is rotated so as to be folded, and the mowing device 1 is rotated around the rolling fulcrum part A1 of the boom device A as a fulcrum. The booms A2 and A3 of the boom device A are folded, and the boom device A is positioned behind the traveling body T. Furthermore, the mowing device 1 is rotated around the rolling fulcrum part A1 as a fulcrum so that the blade part 511 faces upward.

When changing from the working state to the stored state, the working part 51 of the grass cutting device 1 is not in contact with an obstacle and is therefore in the return position. That is, the end 57a of the guide rod 57 is not protruding from the guide rod holding part 572, and the regulating piece 61 can freely rotate up and down with the regulating piece pivot shaft 62 as the fulcrum. When the grass cutting device 1 is inverted from a state in which the cutting blade 511 faces the working surface to a state in which the cutting blade 511 faces upward with the rolling fulcrum part A1 as the fulcrum, the working part 51 rotates until the regulating piece 61 is engaged with the engagement surface 63a. Then, the side part 61b of the regulating piece 61 is located within the movement trajectory of the guide rod 57 sliding so as to protrude from the guide rod holding part 572. The end part 57a of the guide rod 57, which operates in conjunction with the working part 51 that pivots around the fulcrum shaft 31, abuts against the side part 61b of the regulating piece 61. This restricts the relative movement of the guide rod 57 with respect to the guide rod holding portion 572, restricting the rotation of the working portion 51.

Even when the work unit 51 is in the process of being changed from the working state to the stored state as shown in FIG. 4, the side of the restricting piece 61 does not restrict the protrusion of the guide rod 57 due to the restricting piece 61 rotating in the direction of gravity. In other words, in actual work, when working on a place where the work surface is inclined to the left and right of the traveling direction, including the vertical direction, the working unit 51 can rotate around the fulcrum axis 31 even if it is inclined to the left and right of the traveling direction.

When the grass cutting device 1 is in the stored state, the working unit 51 is always inverted. The other end 61a of the restricting piece 61 is also always lowered downward by gravity, that is, maintained away from the cover member 513 or the working arm 50. The grass cutting device 1 in the stored state is fixed integrally with the boom device A with its rotational movement around the fulcrum shaft 31 always restricted. In this way, the swinging of the working unit 51 caused by the rotational movement around the fulcrum shaft 31 is fixed.

In the stored state where the grass cutting device 1 and the boom device A are stored so as to fit within the overall width of the traveling body T, the working unit 51 does not swing due to the pivot shaft 31 when rotating. This allows the grass cutting device 1 to be fixed integrally with the boom device A without the working unit 51 swinging relative to the boom device A, making it easy to transport using the traveling body T. In addition, when changing the position from the working state to the stored state, the operator does not need to perform any work or operation to fix the working unit 51 from rotating around the pivot shaft 31, which prevents the working unit 51 from being fixed due to an operator's incorrect operation. The swinging working unit 51 can be restricted by the rotational movement of the restricting piece 61 alone, without the operator having to manually operate the working unit 51.

When changing from the stored state shown in FIG. 7 to the working state shown in FIG. 6, the above-mentioned operation procedure from the working state to the stored state is performed in reverse. The booms A2 and A3 of the boom device A are rotated to position the grass cutting device 1 on the left and right sides of the traveling direction of the traveling body T. Then, the grass cutting device 1 is rotated around the rolling fulcrum part A1 so that the cutting blade 511 faces the working surface. As a result, the other end 61a of the regulating piece 61 rotates around the regulating piece rotation shaft 62 until it comes into contact with the working arm 50 or the cover member 513 due to its own weight. Then, the side part 61b of the regulating piece 61 is located outside the range of the movement locus where the guide rod 57 slides against the guide rod holding part 572. The end part 57a of the guide rod 57 cannot abut against the side part 61b of the regulating piece 61. As a result, the restriction on the relative movement of the guide rod 57 is released, and the working part 51 can freely rotate around the fulcrum shaft 31.

When the grass cutting device 1 transitions from the stored state to the working state, the rocking motion of the working unit 51 around the fulcrum shaft 31 is automatically released as the grass cutting device 1 rotates around the rolling fulcrum part A1. Even when changing the position from the stored state to the working state, the operator does not need to operate the restricting piece 61, so malfunctions of the working unit 51 around the fulcrum shaft 31 caused by incorrect operation can be prevented. In other words, the restriction on the rocking motion of the working unit 51 can be released with a simple operation without direct manual operation by the operator, and the working unit 51 can be made to be in a state in which it can be rotated.

When the grass cutting device 1 is in the working state, the guide rod 57 can enter the rotation area of the restricting piece 61, which can rotate freely under its own weight. In other words, when the grass cutting device 1 is in the working state, the rotation around the fulcrum shaft 31 is not restricted. Therefore, the working part 51 can rotate around the fulcrum shaft 31 by colliding with an obstacle, and pass through the obstacle.

The procedure for transitioning the mower 1 from a stored state to a working state, or from a working state to a stored state, is shown as a procedure for rotating the mower 1 at the rolling fulcrum part A1 after operating the boom device A. However, it is not necessary to operate in the order described above. Even if the mower 1 is rotated at the rolling fulcrum part A1 first and then the boom device A is operated, as shown in the example, the result is that the working unit 51 in the working state will be in an upside-down position, so that the restriction of the swinging of the working unit 51 by the restricting piece 61 and the release of the restriction can be restricted.

In the embodiment, the boom device A has been described as being arranged with the grass cutting device 1 on the left side of the traveling direction by rotating the booms A2 and A3, but the present invention can be implemented even if they are arranged on the right side of the traveling direction. Also, the grass cutting device 1 and the boom device A have been described as being arranged behind the traveling body T, but the present invention can be implemented even if they are arranged in front of the traveling direction or to the side of the traveling direction. Also, the obstacle has been exemplified as being pillar-shaped, but it may have a shape other than pillar-shaped. Also, the working unit 51 has been exemplified as being capable of being selectively positioned in either the first working area B or the second working area C, but the present invention can be implemented even if it is capable of being positioned in only one of them.

The present invention has been described by the above embodiments and examples, but the descriptions and drawings that form part of this disclosure should not be understood as limiting the present invention. Modifications of the embodiments, examples, and operating techniques based on this disclosure are possible within the scope described in the claims.

REFERENCE SIGNS LIST 1 Grass cutting device 2 Frame 31 Pivot shaft 50 Work arm 51 Work unit 511 Cutting blade 513 Cover member 56 Pressurizing body 57 Guide rod 57a Guide rod end 571 Guide rod fulcrum portion 572 Guide rod holding portion 573 Pressurizing body regulating portion 58 Work unit skid 61 Regulating piece 61a Other end 61b Side portion 62 Regulating piece pivot shaft 63 Holder portion 63a Engagement surface A Boom device A1 Rolling fulcrum portion A2 Boom A3 Boom T Traveling machine body

Claims (4)

A working unit that can be rotated by a fulcrum axis;
a rod that is bridged between the vicinity of the fulcrum shaft and the working unit and is provided so as to be movable relative to a holding unit provided on the working unit;
a restricting piece that is rotatably provided on the working portion and restricts the relative movement of the rod with respect to the holding portion by the rotation of the working portion, thereby restricting the rotation of the working portion;
Equipped with
When the working unit is inverted from a position in a working state to a position in a stored state, the restricting piece restricts the relative movement of the rod by rotating due to its own weight.
A grass cutting device characterized by the above . The restricting piece restricts the rotation of the working unit when the working unit rotates in a direction away from a cover member provided on the working unit.
2. The grass cutting device according to claim 1. The restricting piece restricts the relative movement of the rod with respect to the holding portion by contacting the end of the rod.
3. The grass cutting device according to claim 1 or 2 . The control piece pivot axis, which is the pivot point of the control piece, is located at the middle part between the rod and the upper surface of the working part.
4. A grass cutting device according to claim 1, wherein the grass cutting device is a brush cutter .

Images