JP2023004257A - Grass mower - Google Patents

Abstract

To provide a grass mower capable of detecting undulation and solving inconvenience to an obstacle regardless of a work place.SOLUTION: A grass mower includes: a frame extending forward in a traveling direction at a tip part of a boom device; a work arm having one end side supported turnably in an almost horizontal direction by a fulcrum shaft disposed in the vicinity of a fulcrum cylinder disposed in the frame, and a work part capable of ground work at the other end side; a support shaft disposed coaxially with the fulcrum cylinder; a skid disposed so as to vertically move relatively to the fulcrum cylinder by the support shaft, and disposed in a lower end part of the support shaft so as to come into contact with a work surface; and a control part in which a switch capable of being operated via the support shaft vertically moving with the vertical motion of the skid is disposed, and the switch makes a boom turn upward when detecting the upward movement of the skid, and cancels turning operation of the boom when detecting the downward movement of the skid.SELECTED DRAWING: Figure 2

Description

TECHNICAL FIELD The present invention relates to a mower attached to a traveling body such as a tractor. In particular, the present invention relates to a mowing device capable of working along the undulations of the ground.

Japanese Laid-Open Patent Publication No. 2002-100001 discloses an example of a working machine having a working part provided at the front end of a boom or arm that can swing up and down. According to the present invention, a control device is provided that maintains a mowing device, which is a working part, within a set height range by means of a sensor, which is a detecting part for detecting a distance to the ground. As a result, the working part follows the undulations of the ground and is prevented from coming into contact with the ground.

Japanese Utility Model Laid-Open No. 58-194620

However, if the sensor is installed on the side plate of the mowing device as described in Patent Document 1, it may be damaged by scattered objects or obstacles passing by the side. It is preferable to install it in a difficult position.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a lawn mower capable of detecting undulations regardless of the work place and eliminating the inconvenience caused by obstacles.

One aspect of the present invention for achieving the above object is a boom device having at least one boom which can be turned up and down; One end side is supported by a frame extending forward and a fulcrum shaft provided in the vicinity of a fulcrum tube provided on the frame so as to be able to turn in a substantially horizontal direction. and a support shaft provided coaxially with the fulcrum tube. A switch that can be operated via a contactable skid and a support shaft that moves up and down along with the up and down movement of the skid. When the switch detects the upward movement of the skid, it rotates the boom upward. and a control unit that cancels the swinging motion of the boom when the downward movement of the skid is detected.

According to the present invention, it is possible to provide a lawn mower that can detect undulations regardless of the work place and can eliminate inconveniences caused by obstacles.

BRIEF DESCRIPTION OF THE DRAWINGS It is the front view seen from the advancing direction front of the mower which shows embodiment. It is a side view seen from the advancing direction left side of the grass cutting device which shows embodiment. Fig. 2 is a plan view of the mower showing the embodiment, showing a state where the working unit is positioned in the first working area; Fig. 2 is a bottom view of the mower showing the embodiment, showing a state where the working unit is positioned in the first working area; BRIEF DESCRIPTION OF THE DRAWINGS It is the side view which carried out the cross section of the principal part of the mower which shows embodiment. It is the side view which carried out the cross section of the principal part of the mowing device which shows embodiment, and the right side of illustration is the advancing direction front. An example of the mower attached to the boom device provided in the traveling machine body is shown, and a rear view is shown. 1 is a fluid circuit diagram of a mower showing an embodiment; FIG. It is a control block diagram of the mowing device showing the embodiment. It is a control flow diagram of the mowing device showing the embodiment.

An embodiment of the present invention will be described with reference to the drawings. In the description, the left side shown in FIG. 1 is expressed as the right side with respect to the direction of travel, the right side as the left side with respect to the direction of travel, the left side shown in FIG. 2 as the front side in the direction of travel, and the right side as the rear side in the direction of travel. The left side shown in FIGS. 3 to 5 is the forward side with respect to the traveling direction, and the right side shown in FIG. 6 is the forward side with respect to the traveling direction. 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 to approach the ground side. In the description of the drawings, the same or similar parts may be denoted by the same or similar reference numerals, and descriptions thereof may be omitted. In addition, the drawings used for explanation are schematic, and the relationship with the dimensions of each part may differ from the actual one. Moreover, the technical idea of the present invention can be modified in various ways within the technical scope defined by the claims.

As shown in FIG. 7, the mower 1 is attached to a traveling body T such as a tractor by a boom device A, which is an attachment frame made up of a single boom or a plurality of booms. FIG. 7 shows an example in which the mowing device 1 is attached to a boom device A which is configured by a plurality of boom devices A attached to the rear of the traveling body T and which can be telescopically or bent by a cylinder or the like. The mowing device 1 can be vertically moved with respect to the traveling body T by vertically turning the boom of the illustrated boom device A about the turning shaft.

The mowing device 1 shown in FIGS. A frame 2 extending forward in the traveling direction is attached to the attachment portion 10 . A working arm 50 positioned below the frame 2 and capable of rotating in the horizontal direction has a working part 51 attached to the distal end of the rotating radial direction. The working unit 51 includes a plurality of cutting blades 511 that rotate horizontally, and mowing is performed by rotating the cutting blades 511 . Since the working part 51 can be turned horizontally by the working arm 50, it can pass through an obstacle relatively moving from the front side while turning. Since the working part 51 is arranged so as to protrude from the mounting part 10 by the frame 2, the work can be performed even in a place where there is an obstacle covering the upper part of the working part 51.例文帳に追加Below the front end of the frame 2, a skid 73 that contacts the ground, which is a working surface, is provided so that the working part 51 can be maintained at a constant height. Furthermore, the front of the working part 51 and the skid 73 are arranged to further improve the maintenance of the height of the working part 51 .

The mounting portion 10 can be integrally fixed with the boom device A by fitting it to the tip portion of the boom device A, and can be released from the boom device A by releasing this fixation. . That is, the mowing device 1 is detachable from the boom device A. As shown in FIG. Although the boom device A is fixed to the upper portion of the mounting portion 10 in the embodiment, the fixing position is not limited. Further, a rolling fulcrum A1, which is an axis directed in the direction of travel, is provided at the tip of the boom device A, so that the mowing device 1 can be turned left and right.

A rear end portion of the frame 2 is fixed to one end portion of the mounting portion 10 on the left side in the traveling direction. The frame 2 in the embodiment 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 that can turn horizontally with respect to the first frame 20. It is The first frame 20 is an elongated member, and is arranged so as to protrude forward in the longitudinal direction. A holder portion 22 is provided at the front end portion of the first frame 20, and a bending shaft 40, which is a vertical axis, is provided on the holder portion 22. As shown in FIG. A rear end portion of the second frame 30 is connected to the bending shaft 40 so as to be capable of turning in the horizontal direction.

The second frame 30 is a long member, and is arranged so as to protrude forward in the long direction. The second frame 30 in the embodiment is arranged with its longitudinal direction inclined with respect to the first frame 20 in plan view. Since the second frame 30 is rotatably provided with the bending shaft 40 as a fulcrum, when a load is applied to the second frame 30 due to collision with an obstacle or the like on the rear side of the traveling direction, the second frame 30 turns rearward, Damage to the frame 2 can be prevented. In the embodiment, the first frame 20 and the second frame 30 of the frame 2 are provided so as to be bendable, but they may be integrated and provided so as not to be bendable.

A 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 in the vicinity of an intermediate portion of a fulcrum cylinder 71 that protrudes downward from the front end portion 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, the skid 73 and the support shaft 72 will be described later.

The fulcrum shaft 31 is a vertical shaft and is provided below the front end side of the frame 2 . In the case of the embodiment, it is arranged behind the intermediate portion of the fulcrum tube 71 that hangs down from the front end portion of the frame 2 . One end of the working arm 50 is attached to the fulcrum shaft 31 . The working arm 50 is horizontally rotatable around the fulcrum shaft 31 .

A working portion 51 is provided on the other end of the working arm 50 which is radially away from the axis of the fulcrum shaft 31 . The working part 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 . A motor 512 is provided on the other end side of the working arm 50 to rotationally drive a cutting blade 511 arranged therebelow. A plurality of cutting blades 511 are provided, and are rotatable in the horizontal direction around a motor 512, and are rotated by receiving rotational power of the motor 511. The rotating cutting blade 511 can cut grass present on the work surface.

A cover member 513 is provided on the working arm 50 . The cover member 513 is a member that imitates a drop shape in a plan view, and the drop-shaped projection is arranged toward the fulcrum shaft 31 side. The cover member 513 is positioned above the cutting blade 511 and prevents objects such as grass clippings scattered by the cutting blade 511 from scattering upward. In the case of the embodiment, the other end of the working arm 50 is positioned rearward of the fulcrum shaft 31 in plan view, and the motor 512 serving as the rotary drive shaft of the cutting blade 511 is positioned laterally of the frame 2 .

The working arm 50 horizontally rotates around the fulcrum shaft 31, thereby dividing the working portion 51 shown in FIG. can be positioned in each of the second work areas C of the . The working part 51 indicated by solid lines in FIG. 3 indicates a state of being positioned in the first working area B, and the working part 51 indicated by a two-dot chain line indicates a state of being positioned in the second working area. Mowing work is performed by the working units 51 positioned in the respective regions.

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

The turning restricting body 52 is a rod-shaped member that is elongated in the vertical direction, is arranged near the fulcrum shaft 31 , and passes through the elongated hole 551 . Further, the turning restricting body 52 regulates the turning angle of the work frame 51 in the forward direction in each of the first work area B and the second work area C by coming into contact with the work frame 51 .

A rod-shaped guide rod 57 is rotatably arranged at the other end of the switching piece 55 . The guide rod 57 is arranged so as to span a guide rod fulcrum portion 571 provided at the other end of the switching piece 55 and a guide rod holding portion 572 provided at the other end of the work arm 50 . As shown in FIG. 3, when the working part 51 is positioned 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 portion 572 is located in the first work area B and holds the guide rod 57 so as to be slidable in the axial direction, so that the turning motion of the work arm 50 is not hindered.

A biasing body 56 that biases the working arm 50 toward either the first working area B or the second working area C is arranged on the outer circumference of the guide rod 57 . In the embodiment, the biasing body 56 uses a compression spring. The guide rod 57 serves to guide the biasing member 56 so that it does not shift. A biasing body restricting 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 restricting portion 573 and the guide rod holding portion 572 . The biasing body 56 biases the working portion 51 and the working arm 50 forward in the traveling direction.

Here, the action of the switching piece 55 will be described. By rotating the switching piece 55 around the fulcrum shaft 31, the biasing direction of the biasing body 56 is changed, and the working arm 50 is pushed to either the first work area B or the second work area C side. The work arm 50 positioned in the first work area B or the second work area C is pushed by the biasing member 56 until the work arm 50 comes into contact with the turn restricting body 52 . Turning is restricted at the position where the contact is made.

FIG. 3 shows a state in which the working arm 50 and working portion 51 are positioned in the first working area B. As shown in FIG. Arrows extending in an arc shape shown in FIG. 3 indicate a first rotation direction D and a second turning direction E, which are rotation directions of the working arm 50, the working portion 51, and the switching piece 55 about the fulcrum shaft 31. As shown in FIG. When the working part 51 is positioned in the first working area B, the guide rod fulcrum part 571 of the switching piece 55 positioned behind the fulcrum shaft 31 and on the second working area C side is pushed by the biasing body 56 . As a result, the switching piece 55 is turned in the second turning direction E, which is the counterclockwise direction in plan view. The turning of the switching piece 55 in the second turning direction E is continued until the turning restricting body 52 comes into contact with one end of the long hole 551, after which the turning of the switching piece 55 is restricted. The biasing body 56 continues to bias the switching piece 55 whose turning is restricted in the second turning direction E, and pushes the guide rod holding portion 572 to rotate the working arm 50 in the clockwise rotation direction in plan view. The working arm 50 is rotated in one turning direction D until it contacts the turning restricting body 52 . That is, the working arm 50 and the working portion 51 are biased forward in the direction of movement in the first working area. In the first work area B, the position at which the work arm 50 contacts the turning restrictor 52 is called a return position in the first work area B. As shown in FIG.

In this manner, the working part 51 located in the first working area B is urged in the first turning direction D by the switching piece 55 and the urging body 56, and is deployed away from the side of the frame 2. can be positioned at the return position in the first work area B by pressing. Further, when the working part 51 and the working arm 50 are pushed rearward by an external force, they pivot in the second turning direction E according to the external force. At this time, the distance between the guide rod holding portion 572 and the biasing body restricting portion 573 is reduced, and the biasing body 56 is compressed. The compressed biasing body 56 is in a state of increasing the repulsive force. Since the guide rod fulcrum portion 571 is located on the second work area C side of the line connecting the fulcrum shaft 31 and the guide rod holding portion 572, when the external force is removed, the working arm 571 receives the urging force from the urging body 56. 50 returns to the return position in the first work area B; In this case, the external force in the actual work refers to an obstacle such as a pillar that is higher than the working section. Swirl backwards. When the external force is removed, the working arm 50 and working portion 51 return to their return positions.

The working arm 50 and the working portion 51 can switch the unfolded position from the first working area B to the second working area C by the switching piece 55 and the biasing member 56, as indicated by the two-dot chain line in FIG. When switching, the working arm 50 or the working portion 51 located in the first working area B is turned in the second turning direction E. As shown in FIG. As the working arm 50 continues to turn in the second turning direction E, the working arm 50 and the working portion 51 eventually come to the second working area C side. If the rotation is continued further, the fulcrum shaft 31, the guide rod fulcrum portion 571, and the guide rod holding portion 572 are arranged on a straight line in plan view. Further, if the rotation is continued, the guide rod fulcrum portion 571 will be positioned on the first work area B side from the virtual line segment connecting the fulcrum shaft 31 and the guide rod holding portion 572 , so that the switching piece 55 is moved by the biasing body 56 to the first position. 1 Turn in turning direction D. The switching piece 55 turns until the turning restricting body 52 contacts the other end of the long hole 551 , and then turning in the first turning direction D is restricted by the turning restricting body 52 . Then, the working arm 50 and the working portion 51 are positioned in the second working area C, and are urged forward in the traveling direction, which is the second turning direction E, by the urging body 56 . The urging body 56 continues to urge the switching piece 55 whose turning is restricted in the first turning direction D, and also rotates the working arm 50 in the second turning direction E, which is the counterclockwise rotation direction in a plan view. It is rotated until it contacts the rotation restricting body 52 . This position is called a return position in the second work area C. FIG.

The working part 51 located in the second working area C is urged in the second turning direction E by the switching piece 55 and the urging body 56, and is expanded away from the side of the frame 2 to move to the second working area. It can be located in the return position at C. In addition, when the working part 51 and the working arm 50 are pushed rearward by an external force such as an obstacle, they pivot in the first turning direction D according to the external force. Return to the return position. Since the procedure for moving the working part 51 positioned in the second working area C to the first working area B is similar to the procedure described above, the description thereof will be omitted.

By using the switching piece 55, one working part 51 is deployed to either the first working area B or the second working area C, and is biased so as to face the return position corresponding to each deployed position. The direction of the biasing force of body 56 can be changed.

A working part skid 58 , which is a skid, is provided on the radial side of the rotating cutting blade 511 . The working part skids 58 are rod-shaped sled members formed of rod-shaped members, and a plurality of them are provided around the side of the cutting blade 511 . The working part skids 58 in the case of the embodiment to be described are provided at two locations around the cutting blade 511 laterally symmetrically with respect to the longitudinal direction of the working arm 50 . In the description, one working section skid 58 is called a first working section skid 58a, and the other is called a second working section skid 58b.

In plan view and bottom view, the working part skid 58 is curved along the rotation circumferential direction of the cutting blade 511 . In addition, the working part skid 58 in a side view includes an inclined part 581 connected to the lower part of the cover member 513 and inclined backward as it goes downward, a grounding part 582 extending horizontally from the lower end of the inclined part 581, A rising portion 583 rising from the rear end of the grounding portion 582 and connecting the upper portion to the lower portion of the cover member 513 is provided. Although the illustrated work part skid 58 is formed of a rod-shaped member, it is not limited to this, and may be formed of a plate-shaped member or the like, and may be installed at two or more locations.

The first working part skid 58a, which is one of the working part skids 58 in the first working area B, will be described. In the first work area B, the first work part skid 58a is arranged at the furthest position in the width direction of the traveling direction with respect to the fulcrum shaft 31 . The inclined portion 581a of the first working portion skid 58a extends from the front side of the cutting blade 511 to the rear while curving along the rotation direction of the cutting blade 511 in plan view. The ground contact portion 582a of the first working portion skid 58a, which follows the inclined portion 581a, is elongated, and the elongated direction faces the traveling direction. A rising portion 583 a is arranged from the rear end portion of the ground portion 582 a and connected to the cover member 513 .

The inclined portion 581a of the first working portion skid 58a guides the undulations of the ground, which is the working surface, relatively displaced from the front as the mowing operation progresses forward, to the ground contact portion 582a at the rear. At the time of guidance, the mowing device 1 is gradually raised with a rolling motion around the rolling fulcrum A1 at the tip of the boom device A by the inclination of the inclined portion 581a. That is, the cutting blade 511 is also lifted along the undulations of the ground. Due to the undulations of the ground, the ground contact portion 582a contacts the ground and then slides on the ground along the longitudinal direction, thereby maintaining the relative height between the cutting blade 511 and the undulating ground.

When the undulation of the ground reaches the rising portion 583a, which is the rear end portion of the grounding portion 582a, there is nothing to support the working portion 51, so the working portion 51 rolls along the undulation of the ground again around the rolling fulcrum A1. descend. By configuring in this way, it is possible to prevent contact with the rotating cutting blade 511 due to undulations of the ground. The inclined portion 581a and the ground portion 582a are arranged at positions farthest from the rolling fulcrum portion A1 and the fulcrum shaft 31 in plan view. The first working part skid 58a guides the undulations of the ground at the outermost working width of the cutting blade 511, thereby securing the cutting height of the cutting blade 511 and protecting the cutting blade 511 from contact with the ground. can be done. Further, since the grounding portion 581a is arranged at the outermost part of the working width, the grounding portion 582a can be separated from the rolling fulcrum portion A1, and the rolling operation of the working portion 51 can be performed more reliably. That is, the force required for the turning motion by the rolling fulcrum A1 is reduced to allow smooth turning. Further, it is possible to prevent the inclined portion 581a and the ground portion 582a from digging into the ground.

As described above, the working part 51 may move up and down by bending a plurality of booms of the boom device without moving the rolling fulcrum A1 up and down.

The second working part skid 58b, which is the other working part skid 58 in the first working area B, will be described. The inclined portion 581b of the second working portion skid 58b is located on the fulcrum shaft 31 side in the width direction of the traveling direction and slightly behind the inclined portion 581a of the first working portion skid 58a. The sloped portion 581b with respect to the sloped portion 581a does not interfere with the rolling motion caused by the undulations of the sloped portion 581a and the ground portion 582a, which are skids on one side, and does not get caught on the ground.

The grounding portion 582b following the inclined portion 581b is located on the rear side of the cutting blade 511, and is arranged so that the longitudinal direction intersects with the advancing direction. That is, the longitudinal direction of the ground contact portion 582b of the second working portion skid 58b and the longitudinal direction of the ground contact portion 582a of the first working portion skid 58a are arranged in a direction that intersects with each other. Also, the grounding portion 582b is positioned at the rear end portion of the working portion 51. As shown in FIG. By arranging in this way, the first working part skid 58a receives the undulation relatively moving to the working part 51 from the front before the second working part skid 58b. In other words, the second working section skid 58b in the first working area B does not interfere with the rolling motion of the working section 51 .

The other second working part skid 58b in the first working area B is arranged so that the longitudinal direction of the grounding part 582b intersects with the traveling direction. That is, the longitudinal direction of the grounding portion 582b is in a state in which the working portion 51 rotates about the fulcrum shaft 31 substantially. Therefore, the second working part skid 58b does not hinder the horizontal turning motion of the working part 51 caused by the turning of the working arm 50 around the fulcrum shaft 31 .

The grass cutting device 1 is configured such that the working portion 51 can be protruded from the fulcrum shaft 31 in either the left or right direction in the direction of travel to perform work. In other words, the working part 51 can be positioned in the second working area C to perform the work. When the working part 51 is positioned in the second working area C, the second working part skid 58b is arranged at the farthest position from the rolling fulcrum A1 and the fulcrum shaft 31 in plan view. The first working part skid 58a, which is one of the working part skids 58 in the second working area C, has the inclined part 581a with respect to the inclined part 581b of the second working part skid 58b. It is positioned on the side of 31 and slightly rearward.

The actions and effects of the first working part skid 58a and the second working part skid 58b in the second working area C are different from those of the first working part skid 58a and the second working part skid 58b in the first working area B. The opposite is true. This description is omitted because it is similar to the above description.

When the working part 51 is positioned in the first working area B, the contact part 582a of the first working part skid 58a faces the traveling direction, and when the working part 51 is positioned in the second working area C, the second working part The contact portion 582b of the skid 58b faces the traveling direction. That is, the longitudinal direction of at least one ground contact portion 582 among the plurality of ground contact portions 582 of the work portion skids 58 positioned the work portion 51 in either the first work area B or the second work area C. In the case it faces the direction of travel. By adopting such a configuration, the working unit 51 can smoothly move up and down by the rolling operation to follow the ground, and the mowing device 1 can be horizontally turned around the fulcrum shaft 31 of the working unit 51 . It is possible to avoid obstacles that collide with the working part 51 by relatively moving from the front.

Although the illustrated working part skids 58 are arranged at two positions along the rotation circumferential direction of the cutting blade 511, they may be arranged at three or more positions. In this case, the longitudinal direction of the ground contacting portion 582 of at least one working portion skid 58 should be directed in the traveling direction.

A portion surrounded by the cover member 513, the inclined portion 581, the ground portion 582, and the rising portion 583 forms a passage space S through which an object can pass. Since the passage space S does not block the course of the object, which is grass clippings, scattered laterally from the cutting blade 511 , the object does not accumulate between the working part skid 58 and the cutting blade 511 . In other words, since the cutting blade 511 can work without being in contact with foreign matter, the cutting blade 511 and the motor 512 that rotates it are not loaded, and the cutting object that moves relatively from the front in the traveling direction is removed. You can mow the grass that is a thing.

A bowl-shaped ground body 59 is provided in the lower portion of the working portion 51 . The bowl-shaped ground body 59 is provided coaxially with the rotating shaft of the cutting blade 511 . Since the bowl-shaped grounding member 59 is rotatably mounted independently of the rotation of the cutting blade, the bowl-shaped grounding member 59 maintains a stationary state even when the bowl-shaped grounding member touches the ground, and cuts according to the undulations of the ground. Prevent blade contact.

The lowermost grounding point s1 of the bowl-shaped grounding body is located above the grounding point 582s below the grounding portion 582 of the working part skid 58. As shown in FIG. In the lower part of the working part 51, the part that can come into contact with the ground is composed of a two-tier structure of a working part skid 58 and a bowl-shaped grounding body 59. As shown in FIG.

By guiding the majority of rough undulations with the working part skid 58, the working part 51 is moved up and down, while the bowl-shaped grounding body 59 catches the ground undulations that could not be guided by the working part skid 58, The working part 51 is moved up and down. When there is an undulation of the ground approaching the lower side of the cutting blade 511 as the mower advances, the bowl-shaped grounding body 59 contacts the undulation of the ground to push up the mower 1 via the working portion 51 . Then, the mowing device 1 moves up and down at the rolling fulcrum A1 and the boom device A near the mounting portion 10 .

A vertically long support shaft 72 for supporting a skid 73 is coaxially inserted into a fulcrum tube 71 arranged downward from the front end of the frame 2 . The support shaft 72 is provided so as to be vertically movable with respect to the fulcrum tube 71 . Also, a skid 73 is fixed to the lower portion of the support shaft 72 . That is, the skid 73 is provided so as to be vertically movable.

FIG. 5 is an enlarged view of the skid 73 as seen from the left side in the traveling direction, and is a cross-sectional view of the fulcrum tube 71 and the support shaft 72 . Also, the skid 73 is shown moved upward. As shown in FIG. 5 , a regulating pin 74 is provided on the lower end side of the fulcrum tube 71 in a direction crossing the axial direction of the fulcrum tube 71 . Both ends of the regulating pin 74 are prevented from coming off, and the position is fixed so as not to come off from the fulcrum tube 71 . In the embodiment, the regulating pin 74 is composed of the shaft of the bolt, and the retainer 741 is composed of the head of the bolt and the nut. Of course, the form of the regulation pin 74 is not limited to the illustrated one.

A regulation hole 75 is provided in the lower part of the support shaft 72 inserted into the fulcrum tube 71 . The regulation hole 75 has a diameter larger than the outer diameter of the regulation pin 74 , and the regulation pin 74 is provided so as to be located on the inner diameter side of the regulation hole 75 . The vertical movement of the support shaft 72 is restricted by a restriction pin 74 located on the inner diameter side of the restriction hole 75 . Specifically, when the support shaft 72 moves upward, the regulation pin 74 comes into contact with the inner lower portion of the regulation hole 75, and the support shaft 72 is regulated so that it cannot move upward any more. Conversely, when the support shaft 72 moves downward, the regulation pin 74 comes into contact with the inner upper portion of the regulation hole 75, and the support shaft 72 is regulated so as not to move downward. That is, the support shaft 72 can move up and down within the range in which the regulation pin 74 can move within the regulation hole 75 .

When the lower portion of the regulation hole 75 comes into contact with the regulation pin 74 , even if the skid 73 is pushed upward by the working surface, the upward movement is regulated by the regulation hole 75 . Therefore, since the relative height between the skid 73 and the working portion 51 fluctuates only within the range between the regulating pin 74 and the regulating hole 75, the ground height of the cutting blade 511 of the working portion 51 can be ensured. Damage to the cutting blade 511 due to contact with the ground can be prevented. Although the restriction hole 75 in the embodiment is shown as a round hole, the shape is not limited, and may be a long hole shape or other shapes.

As shown in FIG. 6, a skid biasing member 76 is provided on the upper portion of the support shaft 72 to bias the skid 73 downward. The skid biasing body 76 in the embodiment uses a compression spring. The skid urging body 76 is positioned between the upper end side inside of the fulcrum tube 71 and the stepped portion 721 on the upper part of the support shaft, and urges the support shaft 72 downward. Therefore, the force for moving the support shaft 72 upward exceeds the biasing force of the skid biasing member 76 , thereby moving the skid 73 upward with respect to the fulcrum tube 71 .

A skid 73 fixed to the lower portion of the support shaft 72 is positioned below the working arm 50 and is a sled-like member having a curved portion 731 that is in contact with the ground, which is a working surface. The skid 73 is provided so that the longitudinal direction always faces the traveling direction. The skid 73 prevents the cutting blade 511 of the working portion 51 from coming too close to the work surface by having the curved portion 731 contact the work surface and slide on the work surface.

The curved portion 731 is provided larger than the radius of rotation of the cutting blade 511 . In this embodiment, the bending radius of the bending portion 731 is 350 mm, and the turning radius of the cutting blade 511 is 260 mm. That is, by setting the bending radius of the curved portion 731 to be 1.35 times as large as the turning radius of the cutting blade 511, the skid 73 can be fitted into a small recess existing on the work surface. prevent. Since the skid 73 does not move up and down sensitively to small depressions, the working part 51 does not move up and down sensitively to the work surface. That is, the cutting blade 511 is prevented from coming into contact with small dents or the like, and the working portion 51 is prevented from being damaged.

The curved portion 731 slides while being in contact with the work surface, and moves up and down with respect to the fulcrum tube 71 within a range in which the regulation pin 74 can move through the regulation hole 75 according to the undulations of the work surface. When the skid 73 is separated from the working surface, the skid 73 is lowered by the skid urging member 76 until the curved portion 731 touches the ground or until the regulation pin 74 is regulated by the regulation hole 75 .

Since the skid 73 is located on the front end side of the grass cutting device 1, the skid 73 can reach first before the working part 51, which works as it advances, reaches unevenness or the like. Therefore, the working part 51 moving forward is not damaged by abrupt contact with undulations. In other words, it is possible to detect the undulations of the ground before the working unit 51. Further, since the radius of curvature of the curved portion 731 is set larger than the radius of rotation of the cutting blade 511, it is possible to prevent the lower portion of the working portion 51 from coming into contact with the working surface without sensitively reacting to small undulations. Since the bending radius of the curved portion 731 is large, the working portion 51 does not fit into a recess smaller than the radius of rotation of the cutting blade 511, so that mowing work can be stably continued.

As shown in FIG. 6, an operating piece 78 is fixed to the upper portion of the support shaft 72 . FIG. 6 is an enlarged view of the operating piece 78 and its surroundings, showing a partial cross-section of the fulcrum tube 71 . The right side in the figure is the front in the traveling direction. In addition, the operation piece 78 is raised together with the support shaft 72 , and the switch 79 provided on the operation piece 78 is in contact with the lower surface of the second frame 30 . The operation piece 78 is a plate-like member that is hung from the upper portion of the support shaft 72 while being bent downward, and moves up and down together with the support shaft 72 . A mounting portion 781 for mounting the switch 79, which is formed by bending the lower end portion of the operation piece 78 downward of the second frame 30 and backward of the fulcrum tube 71 in the traveling direction, is positioned. The switch 79 attached to the attachment portion 70 moves up and down as the support shaft 72 and the operating piece 78 move up and down.

The switch 79 is positioned below the second frame 30 and behind the fulcrum tube 71 in the traveling direction. Since the switch 79 is arranged below the second frame 30 , the switch 79 is protected by the second frame 30 in a situation where an obstacle or the like is positioned above the second frame 30 . Further, since the switch 79 is arranged behind the fulcrum tube 71 , the switch 79 is protected by the fulcrum tube 71 even if there is an obstacle or the like relatively moving from the front of the fulcrum tube 71 . That is, since the switch 79 is arranged in a position behind the obstacles existing on the front side and the upper side of the frame 2, damage during the work can be prevented. Furthermore, a cover that covers the upper portion of the operating piece 78 and the upper portion of the support shaft 72 may be provided. This cover protects the operation piece 78 and the upper part of the support shaft 72, and can further prevent the operation of the switch 79 from being hindered by an obstacle or the like.

The switch 79 is connected to the control unit 8 installed separately from the mowing device 1 . Although not shown in the embodiment, it is arranged around the boom device A. When the vertically moving switch 79 reaches near the top dead center, it can emit a detection signal by contacting the lower surface of the second frame 30 . That is, a detection signal is issued to detect that the skid 73 has moved upward. On the other hand, when the switch 79 moves downward from near the top dead center, the switch 79 moves away from the bottom surface of the second frame 30 . Then, a signal is emitted to inform that the switch 79 has left the lower surface of the second frame 30 . That is, a detection signal is issued to detect that the skid 73 has moved downward.

The control unit 8 can detect the operation state of the switch 79 by receiving the signal of the switch 79 . In other words, the controller 8 is provided with the switch 79 so as to be able to identify either the state in which the skid 73 is moving upward or the state in which it is moving upward. The switch 79 in the embodiment uses a limit switch that is a mechanical switch, but the form of the switch 79 is not limited to this. For example, the switch 79 may be optical, sonic, or the like. Further, the switch 79 may detect the amount of displacement or change caused by the vertical movement of the skid 73 or the support shaft 72, and may be a displacement sensor for detecting this.

As shown in FIG. 9, the controller 8 is connected to the switch 79 and the directional control valve H. As shown in FIG. The directional control valve H shown in FIG. 8 sends the fluid pressure generated by the hydraulic pump P to the cylinder J provided in the boom device A in accordance with a command from the control unit 8 to operate the boom device A. As shown in FIG. By the operation of the boom device A, the mowing device 1 can move in the vertical direction. In the embodiment, a plurality of directional control valves H are provided like directional control valves H1, H2, H3 and H4, and a plurality of cylinders J are provided like cylinders 1J, J2, J3 and J4. At least one directional control valve H is operated by the control unit 8 to extend and retract at least one cylinder J, and the boom device A is operated.

The control unit 8 receives the detection signal from the switch 79, and issues an operation instruction to the direction control valve H based on this detection signal, thereby operating the direction control valve H and switching the delivery direction of the fluid pressure. . The cylinder J that receives the fluid pressure expands and contracts to operate the boom device A, and as a result, the mowing device 1 can move in the vertical direction.

Operation control of the mower 1 by the switch 79 and the control unit 8 will be described with reference to FIG.

First, when the control is started, in step S1, the controller 8 determines whether the skid 73 is raised. That is, it is determined whether the switch 79 is raised with respect to the fulcrum tube 71 and is in contact with the second frame 30 . When the control unit 8 determines that the switch 79 has not risen relative to the fulcrum tube 71 and is not in contact with the second frame 30, that is, if it determines that the skid 73 has not risen, the control unit 8 repeats the determination of step 1 again.

When the switch 79 rises with respect to the fulcrum tube 71 and contacts the second frame 30, the switch 79 issues a detection signal, which is a signal indicating that the rise has been detected, to the controller 8. FIG. The control unit 8 determines that the second frame 30 has been contacted by receiving this detection signal. That is, the controller 8 can determine that the skid 73 has risen. When it is determined that the skid 73 has risen, the process proceeds to the next step S2.

In step S2, the control unit 8 operates the direction control valve H to expand and contract the cylinder provided in the boom device to raise the boom device. Along with this, the mowing device 1, which is connected to the boom device by the mounting portion 10, also rises.

Next, in step S3, it is determined again whether or not the skid 73 has risen relative to the fulcrum cylinder 71. When the switch 79 rises with respect to the fulcrum tube 71 and remains in contact with the second frame 30 , the switch 79 continues to send a detection signal, which is a signal indicating that the rise has been detected, to the control section 8 . The control section 8, which has received the increased detection signal, repeats the determination of step 3 again. When the switch 79 descends with respect to the fulcrum tube 71 and separates from the second frame 30, the switch 79 issues a detection signal, which is a signal indicating that the descending has been detected, to the controller 8. FIG. The control unit 8 that has received the lowered detection signal performs the operation of the next step 4 .

In step 4, the control unit 8 operates the directional control valve H so as to stop the expansion and contraction of the cylinder provided in the boom device, thereby stopping the lifting of the boom device. That is, the upward movement of the mowing device 1 is stopped. Returning to step 1 again, the series of control steps described above is repeated.

By detecting the vertical movement of the skid 73 with respect to the fulcrum tube 71, the control section can detect undulations of the work surface on which the mower 1 advances before the working section 51 reaches it. When the controller 8 detects that the skid 73 has moved upward, that is, that there is a projecting portion such as an undulation or an obstacle on the work surface, the controller 8 can operate the boom device A to raise the work portion 51 . can. When the skid 73 moves downward, that is, when it is detected that there is no protrusion such as a depression or an obstacle on the working surface, the boom device A is stopped and the vertical position of the working portion 51 is maintained. In other words, even if there is no projection of the working surface by the skid 73, the working part 51 maintains the current vertical position, so that even if another obstacle is hidden by the grass or the like, the working part 51 can clear the obstacle. There is no risk of accidental damage. Also, the working unit 51 is not damaged by obstacles. In the case of lowering, the working part 51 is lowered by operating the direction control valve H by the operator to expand and contract the cylinder J to operate the boom device A. As shown in FIG. That is, since the worker can lower the working unit after confirming that there is no obstacle, the obstacle and the working unit 51 can be damaged by each other.

Due to the curved portion 731 of the skid 73, even if there is a small uneven surface, the skid 73 does not fit into this uneven surface. Since the boom device A does not move excessively up and down, the boom device A does not operate excessively due to frequent transmission of the detection signal by the switch 79. - 特許庁

Although the boom device in the embodiment has a plurality of booms or arms, it is sufficient that the mowing device 1 can be vertically moved. It is sufficient if there is a suitable boom or arm.

Since the skid 73 is vertically moved by the support shaft 72, the size of the unevenness of the working surface is directly reflected on the skid 73, and the support shaft 72 can be moved up and down. As a result, the frequency of operation of the switch 79 can be set appropriately for the undulating height of the ground, and the boom device A does not operate excessively. In addition, the skid biasing member 76 arranged on the support shaft 72 always biases the skid 73 downward, thereby preventing the skid 73 from moving upward even when there is no foreign matter on the lower surface of the skid. , a factor that hinders the detection operation by the switch 79 can be eliminated.

Although the present invention has been described by the above embodiments and examples, the statements and drawings forming part of this disclosure should not be understood to limit the present invention. Modifications of the embodiments, examples, and operational techniques based on this disclosure are possible within the scope of the claims.

1 mowing device 2 frame 31 fulcrum shaft 50 working arm 51 working part 511 cutting blade 512 motor 513 cover member 58 working part skid 581 inclined part 582 grounding part 582s grounding point 59 bowl-shaped grounding member 71 fulcrum tube 72 supporting shaft 73 skid 731 curved Part 76 Skid biasing body 78 Operation piece 79 Switch A Boom device S Passage space

Claims (6)

a boom device having at least one boom, the boom being rotatable up and down;
a frame provided at the tip of the boom device and extending forward in the traveling direction from the tip of the boom device;
a working arm whose one end side is supported by a fulcrum shaft provided in the vicinity of the fulcrum tube provided on the frame so as to be able to pivot in a substantially horizontal direction, and which has a working portion capable of performing ground work on the other end side;
It has a support shaft provided coaxially with the fulcrum tube, is provided to be vertically movable relative to the fulcrum tube by the support shaft, is provided at the lower end of the support shaft, and is free from contact with the work surface. possible skids and
a switch that can be operated via the support shaft that moves up and down as the skid moves up and down;
a control unit that rotates the boom upward when the switch detects an upward movement of the skid, and cancels the rotating movement of the boom when the switch detects a downward movement of the skid;
A lawn mower comprising: an operation piece connected to the upper end of the support shaft, the switch being capable of moving up and down in synchronism with the vertical movement of the support shaft and capable of operating the switch;
The mower according to claim 1, characterized by comprising: The switch is positioned near the fulcrum tube and behind the fulcrum tube in the traveling direction,
The lawn mower according to claim 1 or 2, characterized in that: the switch is located below the upper end of the support shaft and below the frame;
The lawn mower according to any one of claims 1 to 3, characterized in that: The skid has a curved portion that is provided in an arc shape so as to curve the front end upward,
the radius of the curved portion is greater than the turning radius of the cutting blade of the working portion;
The lawn mower according to any one of claims 1 to 4, characterized in that: the support shaft includes a biasing body that normally biases the skid downward;
The lawn mower according to any one of claims 1 to 5, characterized by comprising:

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