JPH09163847A - Mower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mower capable of preventing mowing blades from breakage caused by the contact of mowing blades with each other. SOLUTION: This mower has a pair of mowing blades 48, 49 which are long and narrow plate-like blades installed as each one end thereof freely rotatable relatively to a blade stand 47 through a supporting shaft 88 installed vertically in the symmetrical positions of the blade stand 47, and rotate as one unit with the blade stand 47 accompanying with the rotation of the blade stand 47, and each free end side of which is arranged at an almost constant position in the vicinity of the peripheral part of the blade stand 47 by a centrifugal force generated by the rotation. Usually, both of the mowing blades are arranged at the positions having a constant distance from the bottom surface of the blade stand 47 and mow at an almost same height from the group surface. The mowing blades 48, 49 have a length capable of interacting each other at a free rotating position where the free end parts are opposed each other. A preventing mechanism of the blades from their contact by transferring one mowing blade 48 to a height for avoiding the contact with another mowing blade 49 where the one mowing blades 48 can freely rotate even in the opposing direction capable of interacting with another mowing blade 49, is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mower, and more particularly, to a grass cutter having a rotary structure having a plurality of cutting blades, which can prevent contact damage between the cutting blades and improve work efficiency at the same time. .

[0002]

2. Description of the Related Art Conventionally, various types of mowers are known. Of these, relatively large tall weeds spread over a wide area, such as riverbeds, wooded areas, and other wastelands, and large and small stones are scattered at the roots of the structure. Many types are used.

As such a structure, the following structure is conventionally known. That is, a support frame whose angle can be changed is provided on a vehicle body that moves along the ground via a raising / lowering arm or the like, and a slightly horizontal disc-shaped tool rest that supports movement along the ground is supported. The tool rest has a relatively large area, and is driven to rotate about the disk-shaped axis by a motor provided on a support frame, and a pair of cutting blades is provided on the bottom side of the tool rest.

Each cutting blade is in the shape of an elongated plate, and one end of each cutting blade can be idled with respect to the tool rest via a support shaft vertically provided at an axially symmetrical position of the tool rest. Further, each cutting blade rotates integrally with the turret with the rotation of the turret, and each free end side is fixed to a slightly fixed position near the peripheral portion of the turret by centrifugal force generated during the rotation. To be placed. Then, both mowing blades are always arranged so as to be separated from the bottom surface of the tool rest by a certain distance, and mowing is carried out at a slightly same height on the ground.

In the mower having such a structure, when there is a stone or the like on the ground, the cutting blade is supported so as to be freely rotatable with respect to the tool rest, so that even if the cutting blade collides with the stone or the like, Since the reciprocating operation is performed in the retreating direction from the rotation direction for cutting, the damage of the blade surface of the cutting blade is suppressed to the minimum.

By the way, if the above-mentioned pair of cutting blades are dimensioned so that their free ends do not interfere with each other when they rotate freely, problems such as damage due to contact between both blades do not particularly occur.

However, when weeding in a wide range is to be mowed, it is desirable to set the size of the mowing blade as large as possible in order to improve the work efficiency, and in that case, the range of the turret having a certain size. In order to set the size of the cutting blade for maximum efficiency, there is a desire to increase the length of the cutting blade to such a degree that it collides during idling.

[0008]

Under the circumstances described above, it is only necessary to provide strength that does not damage even when the cutting blades collide with each other, but it is difficult in practice, and the purpose of application as an actual machine has always been established. It was the reality.

On the other hand, the inventor has paid attention to the following points in the mower having the above-mentioned structure. In other words, in a configuration in which the cutting blade is an elongated plate, and one end of each of the blades can be freely idled with respect to the tool post via a spindle provided perpendicular to the axially symmetrical position of the tool post, the rotation of the tool post With the one that rotates integrally with the turret, the free end side is fixedly placed at a slightly fixed position near the peripheral edge of the turret due to the centrifugal force generated during the rotation, so that both cutting blades are Even if they are arranged at the same height, they do not cause any problem in a normal operating state.

This means that, for example, when one cutting blade comes in contact with a stone or the like and retreats and then moves in the forward direction by a reaction, the other cutting blade also comes in contact with the stone or the like and moves backward, so Since the interference occurs when the free ends of the cutting blades face each other, the contact may be avoided only when the cutting blades are located at the positions where they interfere with each other.

The present invention has been made by paying attention to such a point, and it is a structure that enables efficient mowing with a size configuration that is long enough to interfere with the mowing blade during free rotation. In normal mowing operation, nothing is done. You can work without problems,
At least one of the cutting blades can be retracted from the interference position only when the cutting blade comes to the interference position. Further, with this configuration, it is intended to prevent a damage due to contact between cutting blades and to provide a mower capable of extending its useful life.

[0012]

In order to achieve the above-mentioned object, the invention of claim 1 is a support frame movable along the ground, and a support frame supported by the support frame and rotationally driven around its axis. A slightly horizontal disc-shaped turret,
A pair of mowing blades arranged on the bottom side of the tool rest, each of these mowing blades, one end of each of the mowing blades to the tool rest through a spindle provided perpendicular to the axisymmetric position of the tool rest. It is an elongated plate provided so that it can freely rotate, and rotates integrally with the tool post as the tool post rotates, and each free end side is a peripheral edge of the tool post due to centrifugal force generated during the rotation. It is fixedly placed at a slightly fixed position near the part, and both mowing blades are always placed at a certain distance from the bottom of the turret so that mowing is performed at a slightly same height on the ground. In the mower
Each of the cutting blades has a length that interferes with each other at the idle position where their free ends face each other, and at least a position where at least one cutting blade idles in the facing direction where it interferes with the other cutting blade, A blade contact prevention mechanism for moving one of the cutting blades to a height position that avoids contact with the other cutting blade is provided.

According to a second aspect of the present invention, in the mower according to the first aspect, the blade contact prevention mechanism has a position in which one of the cutting blades idles in a facing direction where it interferes with the other cutting blade,
It is a cam mechanism for moving one of the cutting blades to a position higher or lower than the other cutting blade.

According to a third aspect of the present invention, in the mowing machine according to the second aspect, one of the cutting blades and a vertical spindle supporting one end of the cutting blade on the tool rest are integrally formed, and these cutting blades and the spindle are provided. Is integrally rotatable and integrally lifted, and the cam mechanism includes a cam groove formed in a closed loop spiral shape on the outer peripheral surface of the support shaft, and an engagement pin fixed to the tool rest and engaged with the cam groove. The engaging pin and the cam groove of the support shaft are raised at a position where the one cutting blade idles in a facing direction in which the one cutting blade interferes with the other cutting blade. It is characterized in that the engagement relationship is set.

According to a fourth aspect of the present invention, in the mower according to the second aspect, one of the cutting blades is movably supported by a support shaft in a direction of coming into contact with and separating from the bottom surface of the tool rest, and the cam mechanism is provided with the cutting tool. It has a cam body that protrudes downward from the bottom surface of the stand and engages with the upper surface of the one cutting blade, and the position where the one cutting blade idles in the facing direction in which it interferes with the other cutting blade. The engagement relationship is such that the upper surface of one of the cutting blades is pushed down.

According to a fifth aspect of the present invention, in the mower according to the first to fourth aspects, instead of a pair of cutting blades, a plurality of pairs of cutting blades are provided, and a blade contact prevention mechanism is provided in any one of them. The feature is that the cutting blades are prevented from contacting each other.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 to 9 show an embodiment of a mower according to the present invention. FIG. 1 is a perspective view showing the configuration of the entire mower including the vehicle body, and FIG. 2 is an enlarged perspective view showing the essential configuration of the mower. FIG. 3 is FIG.
4 is a side view taken along arrow A of FIG. 4, FIG. 4 is a side view taken along arrow B of FIG. 2, and FIG. 5 is a sectional view taken along line CC of FIG. Further, FIG. 6 is an exploded perspective view showing a disassembled configuration of essential parts.
FIG. 7 is an enlarged perspective view showing a part of FIG. 6, and FIG. 8 is an enlarged sectional view for explaining the operation.

The mower of the present embodiment is basically an excavator, a support frame attached to the tip of an arm of the excavator so that the angle can be changed freely, and a support frame that can move in a crawling arrangement on the ground.
A slightly horizontal disc-shaped tool rest supported by this support frame and driven to rotate about its axis, a pair of cutting blades arranged on the bottom side of this tool rest, and a blade that avoids contact between the cutting blades. And a contact prevention mechanism.

FIG. 1 shows a state in which a turret is hung near the ground by an excavator and mowed. As shown in FIG. 1, the excavator has a structure in which crawlers 11 are respectively wound around the left and right sides of a vehicle body 10. The crawler 11 allows the vehicle body 10 to freely move back and forth and left and right. There is. A workbench 12 is installed on the upper surface of the vehicle body 10 so as to be capable of turning 360 degrees in the horizontal direction.
The upward / downward arm 13 bent in a letter shape is pivotally supported so as to be capable of swinging in the vertical direction. A hydraulic cylinder 14 for elevation control is interposed between the center of the elevation arm 13 and the front surface of the workbench 12.

At the tip of the elevation arm 13, an upper end portion of a vertically long swing arm 15 having a quadrangular cross section is connected by a bracket 16 and a support pin 17 so as to swing back and forth so as to be suspended. A hydraulic cylinder 18 is interposed between the center of the inner surface and the base end of the swing arm 15. By the expansion and contraction operation of this hydraulic cylinder 18,
The swing arm 15 swings in the front-back direction.

At the tip of the swing arm 15, a flat plate-shaped support frame 19 constituting the base of the mower body can be swung via a pair of left and right vertical brackets 20 and a connecting pin 21, that is, the angle can be changed vertically. It is attached in the state. A horizontal power transmission pin 22 for transmitting the vertical angle adjustment force of the support frame 19 is provided on the front side of the vertical bracket 20, and the lower ends of a pair of left and right vertically long power transmission arms 23 are connected to the power transmission pin 22. ing. The upper end of the power transmission arm 23 is connected to an angle adjusting hydraulic cylinder 24 provided on the front side of the swing arm 15 via a connecting pin 25. The connecting pin 25 attaches a support pin 26 to the swing arm 15. It is supported by a rotating arm 27 attached via the. As a result, the angle adjusting hydraulic cylinder 24 is held at the front position of the swing arm 15.

FIG. 2 is an enlarged view of the outer appearance of the support frame 19 shown in FIG. 1 when viewed obliquely from above. The support frame 19 is formed in a polygonal flat plate shape, and a plurality of reinforcing ribs 35 are provided at a constant height in a radial shape and an edge ring shape along the upper surface thereof. One support plate 36 is fixed on the reinforcing ribs from the central portion of the support frame 19 to the rear side, and the vertical bracket 20 is fixed to the rear end portion of the support plate 36. The front end of the support plate 36 is located at the center of the support frame 19, and a motor for driving a cutting blade, which will be described later, is provided at this portion.
For example, a hydraulic motor 37 is attached. In addition,
This motor may be an electric motor. Below the peripheral edge of the support frame 19, there is provided a shatterproof frame 38 for preventing shattering stones and grass to be shattered by the cutting blade arrangement. The shatterproof frame 38 is composed of, for example, a large number of chains, and these chains are attached in a dense arrangement so as to hang down from the periphery of the support frame 19.

FIG. 3 is a side view showing a state where only the main part of the mower is viewed from the side (direction of arrow A) in FIG. 2, in which the shatterproof frame 38 is omitted. FIG. 4 is a side view showing a state as viewed from the rear side (direction of the arrow) of FIG. As shown in FIGS. 3 and 4, a laterally long ground plate 41 is provided at the rear end of the support frame 19 so as to project downward. The ground plate 41 includes a wide vertical plate portion 42 and L extending outward from the lower edge and both ends of the vertical plate portion 42.
The projecting piece portion 43 is bent in a shape, and the left and right ends of the projecting piece portion 43 are inclined in a “reverse C” shape when viewed from the rear. In addition, a plurality of grounding legs 44, which have a projection length slightly the same as that of the grounding plate 41, are provided on the peripheral edge portion of the support frame 19 excluding the rear portion thereof so as to project downward at intervals. These grounding legs 44 are composed of a vertically long pillar portion 45 and a hemispherical grounding end portion 46 connected to the lower end of the vertically long pillar portion 45. The grounding end portion 46 has a larger diameter than that of the vertically long pillar portion 45 to enable stable grounding. It is like this. Thus, the support frame 19 can be held at a constant height position on the ground by the ground plate 41 and the ground legs 44. A slightly horizontal disc-shaped tool rest 47 is provided in the center of the lower surface of the support frame 19 so as to be surrounded by the ground plate 41 and the ground legs 44, and the pair of cutting blades 4 is attached to the tool rest 47.
8 and 49 are attached.

FIG. 5 shows a tool rest 47 and a cutting blade 48,
It is a longitudinal cross-sectional view which expanded and showed the detailed structure of 49, a rotation mechanism, etc., and FIG. 6 is an exploded perspective view of those components. As shown in these FIG. 5 and FIG.
Is a thin dish container-like structure in which a peripheral portion 56 of a thin metal disk 55 is bent upward on a cylinder.
A thick shaft support member 57 is provided at the center position of the upper surface of the disk 55.
Are integrally provided, welded, or fastened.

The shaft support member 57 is a pedestal portion 58, which is arranged at the center of the upper surface of the disk 55 and has a cylindrical shape with a constant height.
And the vertically long rotor shaft 5 protruding above the base 58.
9, short connecting rod portions 60 and 61 projecting from the lower part of the peripheral surface of the pedestal portion 58 to both sides, and meat that is connected to the tip of the one connecting rod portion 60 and is located on the peripheral portion of the disk 55. The relatively thick bearing tube portion 62 and the other connecting rod portion 61
And a bearing cylinder portion 63 having a relatively small wall thickness, which is continuously provided at the tip of the disk 55 and is located at the peripheral portion of the disk 55.

A square hole 70 is formed in the center of the upper end surface of the rotor shaft 59, and an output shaft 71 having a square cross section protruding downward of the hydraulic motor 37 is inserted into and connected to the square hole 70. Thus, the rotor shaft 59 is rotationally driven around the vertical axis. That is, the hydraulic motor 37 is fixedly supported above the center of the support frame 19 via the motor support member 72. The motor supporting member 72 includes upper and lower two-tiered support plates 73 and 74 that are spaced apart from each other and have a slightly rectangular shape.
4. A vertically long bearing tube 7 fixed so as to penetrate through the central part of 4
5, and these support plates 73,
74 and the bearing sleeve 75 are reinforced by vertical ribs 76 and 77. The upper end surface of the bearing cylinder 75 has a height matching the upper surface of the upper support plate 73, and the lower part of the bearing cylinder 75 penetrates the lower support plate 74 and extends downward.

The lower support plate 74 is attached to the support frame 19
It is mounted and fixed on a support plate 36 provided in the central portion of the bearing, and the lower part of the bearing cylinder 75 penetrates the lower surface of the support frame 19 and projects downward. The hydraulic motor 18 is mounted on the upper support plate 73 and is fixed by bolts 78. Bearings 7 are provided inside the upper and lower ends of the bearing cylinder 75, respectively.
9 and 80 are provided, and the rotor shaft 59 is rotatably supported by these bearings 79 and 80. That is, the output shaft 71 of the hydraulic motor 18 is the rotor shaft 5
The rotor shaft 59 is rotated around the vertical axis through the square hole 70 of the ninth shaft, and the rotation of the rotor shaft 59 causes the pedestal portion 58 to rotate and the tool rest 47 to rotate.

Next, the structure of the pair of cutting blades 48 and 49 will be described. These cutting blades 48, 49 are mounted on a base 58.
Bearing cylindrical portion 6 which is continuously provided to the shaft through connecting rod portions 60 and 61
2 and 63 are provided so as to be respectively idle. As the tool rest 47 rotates, it rotates integrally with the tool rest 47, and each free end side is fixedly arranged at a slightly fixed position near the peripheral edge of the tool rest 47 by centrifugal force generated during the rotation. It is a thing.

More specifically, one cutting blade 48 is shown in FIG.
As shown by arranging on the left side of FIG. 6, it is a thin blade having an elongated rectangular shape as a whole and is arranged slightly horizontally, and is inclined in the thickness direction (upward) once near one end side thereof. After being bent, it is bent again in parallel. That is, the long part on the lower part side is the blade part 85, and the short part on the high part side via the step part 86 is the mounting part 87. Then, a vertical support shaft 88 is mounted on the mounting portion 87.
Are integrally projected. The support shaft 88 includes a shaft main body 90 having a large-diameter flange 89 on the lower end side, and a male screw portion 91 integrally formed on the upper end of the shaft main body 90 so as to project. On the other hand, a mounting hole 96 penetrating in the vertical direction is bored in the mounting portion 87 of the cutting blade 48, and the shaft body 90 and the male screw portion 91 are inserted into the mounting hole 96 from below, and the large diameter flange 89 is mounted. It is welded and fixed while being in contact with the lower surface of the portion 87. The shaft main body 90 and the male screw portion 91 of the support shaft 88 are inserted from below into an insertion hole 92 formed in the disk 55 of the tool rest 47, and then inserted into the shaft hole 93 of the one bearing cylinder portion 62 having a large wall thickness. Then, a nut 95 is screwed onto the male screw portion 91 protruding upward at the upper side of the bearing tubular portion 62 via a washer 94, whereby the cutting blade 48 is attached to the tool rest 47 so as to be free to rotate. As shown in detail in FIG. 5, the lower part of the shaft main body 90 of the support shaft 88 is in a state of protruding from the lower surface of the tool rest 47, whereby the cutting blade 48 moves.
It can be moved upward with a certain distance from the lower surface of the. Note that this point is an element for configuring the blade contact prevention mechanism, and will be described in detail later.

The other shaving blade 49 is a thin blade having an elongated rectangular shape as a whole and is arranged slightly horizontally as shown on the right side of FIGS. 5 and 6.
After being bent obliquely in the thickness direction (upward) near one end side, it is bent again in parallel. That is, the long portion on the lower portion side is the blade portion 105, and the short portion on the higher portion side via the step portion 106 is the attachment portion 107. A vertical support shaft 108 integrally projects above the mounting portion 107. The support shaft 108 has a large-diameter brim 1 on the lower end side.
And a male screw portion 111 integrally formed on the upper end of the shaft body 110. On the other hand, a mounting hole 116 penetrating in the up-down direction is formed in the mounting portion 107 of the mowing blade 49, and the shaft body 110 and the male screw portion 11 are provided in the mounting hole 116.
1 is inserted from below, and the large-diameter flange 109 is attached to the mounting portion 10.
It is welded and fixed while being in contact with the lower surface of 7. The shaft main body 110 and the male screw portion 111 of the support shaft 108 are inserted from below into an insertion hole 112 formed in the disk 55 of the tool rest 47, and then inserted into the shaft hole 113 of the other bearing cylindrical portion 63 having a small thickness. Then, the nut 115 is screwed onto the male screw portion 111 projecting upward through the washer 114 on the upper side of the bearing tubular portion 63, whereby the cutting blade 49 is attached to the tool rest 47 so as to be freely rotatable. In addition,
As shown in detail in FIG. 5, the lower portion of the shaft body 110 of the support shaft 108 does not project from the lower surface of the tool rest 47, and is in a state of not moving in the vertical direction. That is, the other cutting blade 49 rotates at a constant height position below the tool rest 47.

FIG. 7 is an exploded perspective view showing in detail the structure of the mounting portion 87 and the support shaft 88 of the one cutting blade 48 and the structure of the blade contact prevention mechanism 121 described above in an enlarged manner, and FIG. FIG. 3 is a cross-sectional view showing in detail an assembled state of the same portion. Blade contact prevention mechanism 1 in the present embodiment
21 is a cam mechanism for moving one of the cutting blades 48 to a position higher than that of the other cutting blade 49 at a position where the one cutting blade 48 freely rotates in a facing direction where it interferes with the other cutting blade 49. There is.

That is, as shown in FIGS. 7 and 8,
One of the cutting blades 48 and a vertical support shaft 88 that supports one end of the cutting blade 48 on the tool rest are integrally configured, and the cutting blades 4 are
8 and the support shaft 88 can rotate integrally and can move up and down integrally. The cutting blade 48 is shown in FIGS.
In the normal mowing position, the turret 4 is
It can be moved upward with a certain distance from the lower surface of 7.

In this structure, a cam groove 122 having a closed-loop spiral shape, that is, a bidirectional spiral shape and a substantially elliptical shape is formed on the outer peripheral surface of the support shaft 88. In this embodiment, the top portion 123 of the cam groove 122, which has a higher position, faces the blade portion 85 side of the cutting blade 48, that is, the end portion opposite to the end portion on which the support shaft 90 is provided. Also, the cam groove 122
The bottom portion 124 of the is oriented toward the end side where the support shaft 90 is provided. On the other hand, on the side of the tool rest 47, an engagement pin 125 that engages with the cam groove 122 is fixed to the bearing cylinder portion 62 having a large wall thickness that is inserted through the support shaft 90. That is, the bearing tube portion 6
2, a pin insertion hole 126 is formed from the peripheral side of the tool rest 47 so as to be orthogonal to the shaft hole 93, and an engagement pin 125 with a large diameter head 187 is inserted into the pin insertion hole 126 from the outside. It is inserted and inserted into the engagement groove 122 of the support shaft 90 and engaged therewith. Then, as shown by the solid line in FIGS. 5 and 8, when the blade portion 85 side of the cutting blade 48, that is, the free end side is directed to the outside of the tool rest 47, the engagement pin 125 causes the top portion 123 of the cam groove 122. The cutting blade 48
Is in a state of being pushed down by the engagement pin 125 via the support shaft 90. Further, as shown by imaginary lines in FIGS. 5 and 8, when the side free end side of the cutting blade 48 faces the center side of the tool rest 47, that is, when facing the other cutting blade 49 side, the engagement pin 125. Engage with the bottom portion 124 side of the cam groove 122, so that the cutting blade 48 is pushed up by the engagement pin 125 via the support shaft 90.

Next, the operation of the mower according to the present embodiment having the above structure will be described.

When weeding, as shown in FIG.
With the swing arm 15 provided on the body 1 of the excavator facing downward, the support frame 19 is set at a predetermined height position on the ground to be mowed, and the support frame 19 is mowed by operating the hydraulic cylinder 24 for angle suspension. Place it parallel to the ground to be moved and move it along the ground. Then, when the hydraulic motor 37 is activated to rotate the tool rest 47, the tool rest 4
A pair of mowing blades 48 and 49 are rotated by the rotation of 7
7, and the free ends of the mowing blades 48, 49 are rotated by the centrifugal force generated at the time of rotation so that the tool rest 4 is
It is fixedly arranged at a slightly fixed position near the peripheral portion of 7. In this state, the mowing blades 48 and 49 are shown by solid lines in FIGS. 5 and 8, and the mowing blades 48 and 49 rotate at a large radius. At this time, since the engaging pin 125 is engaged with the top portion 123 of the cam groove 122 of the support shaft 90, one of the mowing blades 48 is pushed down and the other mowing blade is shown as shown by the solid line in FIG. The placement is as low as the blade 48. State Both cutting blades 4 in this state
Both 8 and 49 are always arranged at a certain distance from the bottom surface of the tool rest 47, and mow the grass at a slightly same height on the ground.

Then, it is assumed that a stone or the like is present during mowing and the cutting blade collides with it. Then, as shown by phantom lines in FIG. 5, for example, one of the cutting blades 48 comes into contact with a stone or the like and retreats and then moves in the forward direction by a reaction, while the other preceding cutting blade 49 also comes into contact with the stone or the like. Then, the blades rotate in the backward direction, and the free ends of both the cutting blades 48 and 49 face each other. At this time, in the conventional configuration, since the height positions where the cutting blades 48 and 49 interfere with each other do not change, there is a risk that they may contact and be damaged.

However, in the configuration of the present embodiment, when the cutting blades 48, 49 are in the idle position where their free ends face each other, as shown by the phantom line in FIG. The pin 125 is the bottom portion 123 of the cam groove 122 of the support shaft 90.
, And one of the cutting blades 48 is positioned above the other cutting blade 49, and rotates at a level with different vertical heights. Therefore, although the cutting blades 48 and 49 have such a length that they interfere with each other at the normally separated positions, contact is avoided by the action of the cam mechanism that is the blade contact prevention mechanism 121, and there is no risk of contact damage. It does not occur.

Therefore, in the mowing machine according to the present embodiment, in a normal mowing operation without losing the advantage that the mowing blades 48 and 49 have a structure long enough to interfere with each other during idling and efficient mowing is possible. It is possible to work without any problems, and one of the cutting blades 48 can be retracted from the interference position only when the cutting blades 48 and 49 come to the interference position, thereby preventing damage due to contact between the cutting blades and extending the service life for that long. The effect is that it can be realized.

Although the position of one of the cutting blades 48 is raised at the interference position in the above embodiment, it may be lowered. Further, in the above embodiment, the cam mechanism is provided only on one of the cutting blades 48 in order to achieve the most efficient configuration, but both cutting blades 48 may be provided with a cam mechanism if necessary.

It is also possible to replace the pair of cutting blades with one or more pairs of cutting blades, and to provide a blade contact prevention mechanism in any one of them to prevent the cutting blades from contacting each other. is there.

Furthermore, in the above-mentioned embodiment, the type which is attached to a large vehicle body has been described, but the present invention is not limited to this, but can be applied to various types of configurations such as a small type and a push type. .

9 and 10 show another embodiment of the mower according to the present invention, and FIG. 9 is an enlarged vertical sectional view showing the detailed structure of the tool rest and the cutting blade, the rotating mechanism and the like. FIG. 10 is an exploded perspective view of those parts.

The mower of the present embodiment is basically the same as that of the above-mentioned one embodiment, and the excavator and the arm of the excavator are attached to the tip of the excavator so as to be able to change the angle and move in a position to crawl on the ground. Support frame, a slightly horizontal disk-shaped turret supported by this support frame and driven to rotate about its axis, a pair of cutting blades arranged on the bottom side of the turret, and a cutting blade. There is no difference in the point that it is equipped with a blade contact prevention mechanism that avoids contact with.

In this embodiment, only the blade contact prevention mechanism is different from the one embodiment. Therefore, FIGS.
4 will also be referred to the description of the present embodiment, and the same members as those shown in these figures will be denoted by the same reference numerals to describe the present embodiment.

In the present embodiment, as shown in FIGS. 9 and 10, the tool rest 47 has a thin dish container-like configuration in which the peripheral portion 56 of the thin-walled metal disk 55 is bent upward on the cylinder. belongs to. A thick shaft support member 57 is provided at the center position of the upper surface of the disk 55 integrally, by welding, fixing, fastening or the like.

However, the shaft support member 57 is a columnar pedestal portion 5 arranged at the center of the upper surface of the disk 55 and having a constant height.
8 and a rotor shaft 59 protruding upward from the upper end of the pedestal portion 58.

A square hole 70 is formed at the center of the upper end surface of the rotor shaft 59, and an output shaft 71 having a square cross section protruding downward of the hydraulic motor 37 is inserted and connected to the square hole 70. Thus, the rotor shaft 59 is rotationally driven around the vertical axis. That is, the hydraulic motor 37 is fixedly supported above the center of the support frame 19 via the motor support member 72. The motor support member 72 includes slightly quadrangular upper and lower two-stage support plates 73 and 74 arranged at intervals and these support plates 73 and 74.
Long bearing cylinder 75 fixed so as to penetrate through the center of the
And the supporting plates 73, 7
4 and the bearing sleeve 75 are reinforced by vertical ribs 76 and 77. The upper end surface of the bearing cylinder 75 has a height matching the upper surface of the upper support plate 73, and the lower part of the bearing cylinder 75 penetrates the lower support plate 74 and extends downward.

The lower support plate 74 is attached to the support frame 19
It is mounted and fixed on a support plate 36 provided in the central portion of the bearing, and the lower part of the bearing cylinder 75 penetrates the lower surface of the support frame 19 and projects downward. The hydraulic motor 18 is mounted on the upper support plate 73 and is fixed by bolts 78. Bearings 7 are provided inside the upper and lower ends of the bearing cylinder 75, respectively.
9 and 80 are provided, and the rotor shaft 59 is rotatably supported by these bearings 79 and 80. That is, the output shaft 71 of the hydraulic motor 18 is the rotor shaft 5
The rotor shaft 59 is rotated around the vertical axis through the square hole 70 of the ninth shaft, and the rotation of the rotor shaft 59 causes the pedestal portion 58 to rotate and the tool rest 47 to rotate.

The cutting blades 48, 49 are provided so as to be inserted into the through holes 145, 155 formed in the disk 55 so as to be freely rotatable, and rotate integrally with the tool rest 47 as the tool rest 47 rotates. At the same time, each free end side is fixedly arranged at a slightly fixed position near the peripheral portion of the tool rest 47 by centrifugal force generated during the rotation.

One of the cutting blades 48 is shown in FIG. 9 and FIG.
As shown by arranging it on the left side of the figure, it is a thin blade with a slender rectangular shape as a whole and is arranged slightly horizontally, and it is bent obliquely in the thickness direction (upward) near one end side. After that, it is bent again in parallel. That is, the long part on the lower part side is the blade part 85, and the short part on the high part side via the step part 86 is the mounting part 87. A vertical support shaft 141 is integrally projected on the mounting portion 87. The support shaft 141 has a large-diameter collar 14 on the lower end side.
The shaft main body 143 having the number 2 and the male screw portion 144 integrally formed on the upper end of the shaft main body 143 to project.
On the other hand, a mounting hole 96 penetrating in the vertical direction is formed in the mounting portion 87 of the cutting blade 48, and the shaft body 143 and the male screw portion 144 are inserted from below into the mounting hole 96 so that the mounting body 96 can slide in the vertical direction. Has become. A compression coil spring 148 is interposed between the large-diameter flange 142 of the support shaft 141 and the lower surface of the mounting portion 87 of the cutting blade 48. The shaft body 142 and the male screw portion 144 of the support shaft 141 are inserted into the insertion hole 145 formed in the disk 55 of the tool rest 47 from below with the washer 149 interposed therebetween, and then the male screw portion 144 protruding upward. A nut 147 is mounted on the upper side of the disc 55 via a washer 146.
Are screwed together, whereby the cutting blade 48 is attached to the tool rest 47 so as to be free to rotate.

The other cutting blade 49 is shown in FIG. 9 and FIG.
As shown by arranging it on the right side of the figure, it is a thin blade with a slender rectangular shape as a whole and is arranged slightly horizontally, and it is bent obliquely in the thickness direction (upward) near one end side. After that, it is bent again in parallel. That is, the long portion on the lower portion side is the blade portion 105, and the short portion on the higher portion side via the step portion 106 is the attachment portion 107.
Then, a vertical support shaft 151 is provided on the mounting portion 107.
Are integrally projected. The support shaft 151 includes a shaft main body 153 having a large diameter flange 152 on the lower end side, and a male screw portion 154 integrally formed on the upper end of the shaft main body 153 so as to project. On the other hand, a mounting hole 96 penetrating in the vertical direction is bored in the mounting portion 87 of the cutting blade 49, and the shaft body 153 and the male screw portion 154 are inserted from below into the mounting hole 96. The large-diameter flange 152 of the support shaft 151 is in contact with the lower surface of the mounting portion 87 of the mowing blade 49. The shaft body 153 and the male screw portion 154 of the support shaft 151 are inserted into a through hole 155 formed in the disk 55 of the tool rest 47 from below with a washer 159 interposed therebetween, and then the male screw portion 154 protruding upward. Disk 5
A nut 157 is screwed on the upper side of 5 via a washer 156, whereby the cutting blade 48 is attached to the tool rest 47 so as to be free to rotate. As shown in detail in FIG. 9, the lower portion of the shaft body 153 of the support shaft 151 does not project from the lower surface of the tool rest 47, and is in a state of not moving in the vertical direction. That is, the other cutting blade 49
Rotates at a constant height position below the tool rest 47.

In the present embodiment, FIG. 9 and FIG.
As shown in detail in FIG. 0, the lower part of the shaft body 143 of the support shaft 141 of the one cutting blade 48 is made to project from the lower surface of the cutting blade 48 by the elastic force of the compression coil spring 148. Although the cutting blade 48 is in contact with the lower surface of the tool rest 47, it can be moved downward by a certain distance when a large pressing force acts against the elastic force of the compression coil spring 148. This point is an element for configuring the blade contact prevention mechanism in the present embodiment.

Blade contact prevention mechanism 12 in the present embodiment
1 is a cam mechanism for moving one of the cutting blades 48 to a position lower than that of the other cutting blade 49 at a position where the one cutting blade 48 freely rotates in a facing direction in which it interferes with the other cutting blade 49. There is.

That is, as shown in FIGS. 9 and 10, one of the cutting blades 48 and the vertical support shaft 141 which supports one end of the cutting blades 48 on the tool rest are movable in a direction in which they approach and separate from the bottom surface of the tool rest 47. While being supported, the cam mechanism is a turret 4.
7 has a cam body 161 which projects downward from the bottom surface and engages with the upper surface of one of the cutting blades 48. The cam body 161 has, for example, a circular arc plate shape, and has a downward top portion 162 that largely projects downward and a bottom portion 163 that has a small degree of protrusion. Then, at a position where one of the cutting blades 48 freely rotates in a facing direction where it interferes with the other cutting blade 49, an engagement relationship of pushing down the upper surface of the one cutting blade 48 is set.

The operation of the mower according to another embodiment having such a configuration will be described.

In the mowing operation, the swinging arm 15 provided on the body 1 of the excavator is directed downward and the support frame 19 is set at a predetermined height position on the ground to be mowed, as in the case of the above-described embodiment. , Hydraulic cylinder for angle suspension 2
By the operation of 4, the support frame 19 is arranged parallel to the ground to be mowed and moved along the ground. Then, when the hydraulic motor 37 is activated to rotate the tool rest 47,
A pair of mowing blades 48 and 49 rotate integrally with the tool rest 47 as the tool rest 47 rotates, and the free ends of the mowing blades 48 and 49 are peripheral portions of the tool rest 47 due to centrifugal force generated during the rotation. It is fixedly placed in a slightly fixed position in the vicinity.

In this state, the mowing blades 48 and 49 are shown by solid lines in FIG. 9, and the mowing blades 48 and 49 rotate with a large radius. At this time, one of the mowing blades 4
Since 8 is located at a position displaced from the downwardly facing top portion 162 of the cam body 161, one of the mowing blades 48 is pushed up by the compression coil spring 148 and is the same as the other mowing blade 48 as indicated by the solid line in FIG. The placement is high. In this state, both mowing blades 48, 49 are always arranged at a certain distance from the bottom surface of the tool rest 47, and mow the grass at a slightly same height above the ground.

Then, it is assumed that a stone or the like is present during mowing and the cutting blade collides with it. Then, as shown by the phantom line in FIG. 9, for example, one of the cutting blades 48 comes into contact with a stone or the like and retreats and then moves in the forward direction by a reaction, while the other preceding cutting blade 49 also comes into contact with the stone or the like. Then, the blades rotate in the backward direction, and the free ends of both the cutting blades 48 and 49 face each other.

At this time, in the configuration of the present embodiment, one of the cutting blades 48 has the downwardly facing top portion 162 of the cam body 161.
, And one of the cutting blades 48 is positioned below the other cutting blade 49, and the upper and lower heights are rotated at different levels. Therefore, although the cutting blades 48 and 49 have such a length that they interfere with each other at the normally separated positions, contact is avoided by the action of the cam mechanism that is the blade contact prevention mechanism 121, and there is no risk of contact damage. It does not occur.

Therefore, also in the mower of the present embodiment, as in the case of the above-mentioned one embodiment, there is an advantage in that the grass cutting blades 48 and 49 are long in size so as to interfere with each other during idling and can be effectively mowed. You can work without any problems in normal mowing operation without losing, and the cutting blade 4
When one of the cutting blades 8 and 49 comes to the interference position, one of the cutting blades 48 can be retracted from the interference position, thereby preventing damage due to contact between the cutting blades and prolonging the useful life. Is.

Although the position of one of the cutting blades 48 is lowered at the interference position in the other embodiments described above, for example, a cam body is provided on the disc 55 and the grass cutting blade 48 is inserted through the engaging body. You may make it raise a position. Also,
Although only one of the cutting blades 48 is provided with the cam mechanism, both cutting blades 48 may be provided with the cam mechanism if necessary.

It is also possible to replace the pair of cutting blades with a plurality of pairs of cutting blades, and to provide a blade contact prevention mechanism in any one of them to prevent the cutting blades from contacting each other. is there.

[0063]

As described in detail above, according to the present invention, the grass cutting blade is configured to be able to efficiently cut grass with a size configuration long enough to interfere with the grass cutting blade during free rotation, and there is no problem in normal grass cutting operation. It is possible to work without it, and at least one cutting blade can be retracted from the interference position only when the cutting blade comes to the interference position, thereby preventing damage due to contact between the cutting blades and prolonging its useful life. And so on.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the overall configuration of an embodiment of a mower according to the present invention.

FIG. 2 is an enlarged perspective view showing a support frame that constitutes a main part according to an embodiment of a mower according to the present invention.

FIG. 3 is a view of the mower shown in FIG. 2 as seen from the direction of arrow A.

4 is a view on arrow B of the mower shown in FIG. 2. FIG.

FIG. 5 is an enlarged sectional view showing a main part according to an embodiment of a mower according to the present invention.

6 is an exploded perspective view showing the parts of the mower shown in FIG. 5 in an exploded manner.

FIG. 7 is an exploded perspective view showing the cam mechanism portion of the parts of the mower shown in FIG. 6 in an exploded manner.

FIG. 8 is an enlarged cross-sectional view for explaining the operation of the embodiment of the mower according to the present invention.

FIG. 9 is an enlarged cross-sectional view showing the main parts of another embodiment of the mower according to the present invention.

FIG. 10 is an exploded perspective view showing the cam mechanism portion of the parts according to another embodiment of the mower according to the present invention in an exploded manner.

[Explanation of symbols]

 10 Vehicle Body 13 Elevation Arm 15 Swing Arm 19 Support Frame 20 Vertical Bracket 24 Angle Adjusting Hydraulic Cylinder 35 Reinforcing Rib 36 Support Plate 37 Hydraulic Motor 38 Scattering Prevention Frame 41 Ground Plate 42 Vertical Plate Part 43 Projecting Piece 44 Grounding Leg 47 Cutlery Base 48 Cutting blade 49 Cutting blade 55 Disc 56 Peripheral part 57 Shaft support member 58 Pedestal part 59 Rotor shaft 60 Connecting rod part 61 Connecting rod part 62 Bearing cylinder part 63 Bearing cylinder part 70 Square hole 71 Output shaft 72 Motor support member 73 Top Support plate 74 Lower support plate 75 Bearing tube 76 Vertical rib 77 Vertical rib 78 Bolt 79 Bearing 80 Bearing 85 Blade portion 86 Stepped portion 87 Attachment portion 88 Spindle 89 Large diameter flange 90 Shaft body 91 Male screw portion 92 Insert hole 93 Shaft hole 94 Washer 95 Nut 96 Mounting hole 10 Blade portion 106 Step portion 107 Mounting portion 108 Support shaft 109 Large diameter flange 110 Shaft body 111 Male screw portion 112 Insertion hole 113 Shaft hole 114 Washer 115 Nut 116 Mounting hole 121 Blade contact prevention mechanism 122 Cam groove 123 Top portion 124 Bottom portion 125 Engagement Dowel pin 126 Pin insertion hole 127 Large diameter head 141 Support shaft 142 Large diameter flange 143 Shaft body 144 Male screw part 145 Insertion hole 146 Washer 147 Nut 148 Compression coil spring 151 Spindle 152 Large diameter flange 153 Shaft body 154 Male screw part 155 insertion Hole 156 Washer 157 Nut 161 Cam body 162 Downward top part 163 Bottom part

Claims (5)

[Claims] 1. A support frame movable along the ground, a slightly horizontal disk-shaped tool rest supported by the support frame and rotationally driven about its axis, and a bottom face side of the tool rest. And a pair of mowing blades, each of which is provided such that one end thereof can be freely idled with respect to the tool post via a support shaft vertically provided at an axially symmetrical position of the tool post. In the shape of a slender plate that rotates integrally with the turret as the turret rotates,
Each free end side is fixedly arranged at a slightly fixed position near the peripheral edge of the tool post by centrifugal force generated during its rotation, and both cutting blades are always separated from the bottom surface of the tool post by a certain distance. In the mower, which is arranged to perform mowing at a slightly same height on the ground, each of the cutting blades has a length that interferes with each other at the idle position where their free ends face each other. A blade contact prevention mechanism that moves one of the cutting blades to a height position that avoids contact with the other cutting blade is provided at a position where at least one cutting blade freely rotates in the facing direction where it interferes with the other cutting blade. A mower characterized by that. 2. The mowing machine according to claim 1, wherein the blade contact prevention mechanism is arranged such that one cutting blade freely rotates in a facing direction in which the other cutting blade interferes with the other cutting blade, and the one cutting blade moves to the other cutting blade. A mower characterized by a cam mechanism for moving it to a higher or lower position. 3. The mower according to claim 2, wherein one of the mowing blades and a vertical spindle supporting one end of the mowing blade on the tool rest are integrally formed, and the mowing blades and the spindle are integrally rotated and integrally formed. The cam mechanism includes a cam groove formed in a closed loop spiral shape on the outer peripheral surface of the support shaft, and an engagement pin fixed to the tool rest and engaged with the cam groove. The engagement pin and the cam groove of the support shaft are set in an engagement relationship in which the one cutting blade rises at a position where the one cutting blade freely rotates in a facing direction in which the other cutting blade interferes with the other cutting blade. A mower characterized by being used. 4. The mower according to claim 2, wherein one of the cutting blades is supported movably in a direction of approaching and separating from a bottom surface of the tool rest via a support shaft, and the cam mechanism is downward from the bottom surface of the tool rest. Has a cam body that protrudes to engage with the upper surface of the one cutting blade, and one of the cutting blades idles in a facing direction where the cutting blade interferes with the other cutting blade. A mower characterized by being set to have an engagement relationship in which the upper surface of the blade is pushed down. 5. The mower according to claim 1,
A mowing machine characterized in that a plurality of pairs of cutting blades are provided instead of a pair of cutting blades, and a blade contact prevention mechanism is provided in any one of them to prevent contact between the respective cutting blades.