JP2003247247A - Clamshell having antiscattering mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a clamshell having an antiscattering mechanism capable of preventing sludge from dropping from an engaging part of a bucket by a simple configuration. <P>SOLUTION: This clamshell 1 is constituted in such a way that it has a hydraulic cylinder 2 and a hydraulic rod 3 arranged substantially vertically, a bracket 4 for pivotally supporting the bucket is provided in a lower end part of the hydraulic rod 3, a pair of bucket rotation shafts 5a, 5b are provided in the bracket 4 for pivotally supporting the bucket, and a pair of buckets 6a, 6b opened and closed to the right and left sides are suspended on the bucket rotation shafts 5a, 5b. A cover member 10 provided with an antiscattering cover 10a extended on an outer side of the buckets 6a, 6b and capable of wrapping a bucket engaging part internally in a tip part is rotatably attached to either of the bucket rotation shafts 5a, 5b. An eccentric weight 11 for aligning a position of a central part of the antiscattering cover 10a with a position of a substantially vertical lower part of the bucket engaging part when the cover member 10 is suspended on the bucket rotation shafts 5a, 5b is provided in the cover member 10. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clamshell which is an excavator type excavator for excavating by grasping soil or the like with a suspended bucket that opens to the left and right, and in particular, soil, sand, mud and the like are excavated in the bucket. The present invention relates to a clamshell having a scattering prevention mechanism that prevents scattering of soil or the like during transportation while grasping.

[0002]

2. Description of the Related Art A conventional clam shell is shown in FIG.

The clam shell 30 has a pair of suspended buckets 31a and 31b which are open to the left and right. The excavator claw 3 with the buckets 31a and 31b open
By pushing 2a, 32b against the ground at the bottom of the excavation pit, the weight of the clamshell body causes the excavation claw 32a,
32b cuts into the ground. Then, the buckets 31a, 31
By forcibly closing b, soil, mud, etc. are trapped in the bucket, and part of the ground is excavated.

Subsequently, the buckets 31a and 31b are completely closed, and the clamshell body is hoisted by a hoist while holding soil, sand, mud, etc. in the buckets 31a and 31b.
It is transported in the horizontal direction, the clam shell is positioned on a loading platform such as a dump truck, and the buckets 31a and 31b are opened to transfer the soil, mud and the like inside to the dump truck.

By repeating the above operation, the work of excavation and removal of excavated soil can be performed.

[0006]

However, in the conventional clamshell, when the bucket of the clamshell is closed, a slight gap is generated in the meshing portion of both buckets,
Soil, sand, mud, etc. may fall from this gap. In particular, in the case of sludge containing a large amount of water, the amount of falling is large.

With the bucket holding dirt, sand, mud, etc.,
When the clamshell is transported to the loading platform of the dump truck, the above-mentioned fall of soil, sand and mud continues. Therefore, soil, sludge, etc. are scattered at the work site of the clamshell transport route,
The cleanliness of the work site is significantly impaired.

Conventionally, in order to prevent the scattering of soil and sludge as described above, the work site has been manually cleaned at regular intervals, but this cleaning requires a great deal of time and labor. Further, although the work site could be cleaned by cleaning, the work site could not be contaminated until it was cleaned, which was not preferable in terms of the work environment.

On the other hand, in order to solve the problem of sludge dropping from the meshing portion of the bucket described above, it is conceivable to provide an openable cover on the outside of the bucket to prevent scattering. FIG. 9 shows a clamshell having a scattering prevention mechanism provided with this double-structured openable cover.

However, the double structure of the bucket requires the provision of a mechanism for driving the outer openable cover, which causes a problem that the entire apparatus becomes complicated and large. Further, even if the openable cover is provided, there remains a problem that sludge passes through the meshing part of the inner excavating bucket and drops from the meshing part of the outer openable cover.

Therefore, the problem to be solved by the present invention is to provide a clamshell having a scattering prevention mechanism capable of preventing the sludge and the like from dropping from the meshing portion of the bucket with a simple structure. is there.

[0012]

A clamshell having a scattering prevention mechanism according to a first aspect of the present invention has a hydraulic cylinder arranged substantially vertically and a hydraulic rod extending and contracting downward from the hydraulic cylinder. A bracket for pivoting the bucket is provided at the lower end of the rod, a pair of bucket rotating shafts for pivoting the bucket is provided on the bracket for supporting the bucket, and a pair of buckets that are opened and closed left and right are suspended on the bucket rotating shaft. In the clamshell, on one of the bucket rotation shafts, a scattering prevention cover that extends from the bucket rotation shaft to the outside of the bucket and that can enclose a meshing portion when both buckets are closed is provided at a tip portion of the cover. A cover member provided is rotatably attached to the cover member when the cover member is suspended on the bucket rotation shaft. It is characterized in that the central portion of the cover provided with the eccentric weight to be aligned substantially vertically below the engagement portion of the bucket.

According to the present invention, there is provided one cover member suspended from the bucket meshing portion on the bucket rotation shaft at a position eccentric to the bucket meshing portion, and the center portion of the scattering prevention cover is brought into contact with the bucket meshing portion by the action of the eccentric weight. Since it is located almost vertically below, it can catch sludge and the like falling from the bucket meshing portion.

A clamshell having a scattering prevention mechanism according to claim 2 of the present application is the clamshell according to claim 1, wherein a first pulley is provided on an upper end of the hydraulic cylinder or a member connected to the upper end of the hydraulic cylinder, and the bucket is provided. A wire, one end of which is connected to a part of a pivot bracket or a member in the vicinity thereof, is wound around the first pulley to connect the other end to a part of the cover member, and the cover is provided when the hydraulic rod extends. The member is configured to rotate around the bucket rotation shaft by a predetermined angle, and when the hydraulic rod contracts, the cover member is suspended from the bucket rotation shaft.

A clamshell having a scattering prevention mechanism according to claim 3 of the present application is the clamshell according to claim 1, wherein a first pulley is provided on an upper end portion of the hydraulic cylinder or a member connected to the upper end portion of the hydraulic cylinder, and the bucket is provided. A second pulley is provided on the pivot bracket or a member connected to the bracket.
A wire whose one end is connected to the upper end of the hydraulic cylinder or a part of the member in the vicinity thereof is wound around the second pulley and the first pulley to connect the other end to a part of the cover member, and the hydraulic rod is When the cover member is extended, the cover member is rotated about the bucket rotating shaft by a predetermined angle, and when the hydraulic rod is contracted, the cover member is suspended from the bucket rotating shaft. It is what

According to the above clam shell, the bucket and the cover member are opened and closed in conjunction with each other by the action of the pulley, so that the operator's operation load can be reduced.

A clamshell having a scattering prevention mechanism according to claim 4 of the present application is the clamshell according to claim 1, wherein an electric winch is provided on an upper end portion of the hydraulic cylinder or a member connected to the upper end portion of the hydraulic cylinder. A wire is connected to a part of the cover member by which a winch winds up and pays out.

According to a fifth aspect of the present invention, there is provided a clamshell having a scattering prevention mechanism, wherein the clamshell according to the fourth aspect is provided with a sensor for detecting an expansion / contraction distance of the hydraulic rod, in one of the hydraulic cylinder and the hydraulic rod. The winch has a management device that inputs a signal that detects that the hydraulic rod has extended from a certain distance or more from the sensor and outputs a command to wind up the wire so that the cover member has a predetermined rotation angle. It is characterized by that.

According to this clam shell, the sensor can detect the expansion and contraction of the hydraulic rod, detect the operation of opening the bucket largely, and wind the cover member accordingly.

According to a sixth aspect of the present invention, there is provided a clamshell according to the fifth aspect, in which the winch receives a signal from the sensor for detecting that the hydraulic rod has contracted for a certain distance or more. A management device that outputs a command to reel out the wire until the cover member wound up at the predetermined rotation angle is in a suspended state is provided.

According to this clamshell, the sensor can detect the expansion and contraction of the hydraulic rod, detect the operation of opening and closing the bucket greatly, and wind up the cover member accordingly,
Can be lowered.

A clamshell having a scattering prevention mechanism according to claim 7 of the present application is the clamshell according to claim 5, wherein the winch inputs an operation signal of a switch provided on an operation panel of an operator to perform the predetermined rotation. The wire is unrolled until the cover member wound up at an angle is in a suspended state.

According to this clam shell, the cover member can be held in the rolled-up state in a normal operation, and the cover member can be lowered by the switch operation of the operator only when the cover member is really needed. .

A clamshell having a scattering prevention mechanism according to claim 8 of the present application is the clamshell according to claim 1, wherein the cover member is provided between the hydraulic rod and the cover member when the hydraulic rod extends. Power that rotates the expansion and contraction of the hydraulic rod in conjunction with the rotation of the cover member so that the cover member is suspended from the bucket rotation shaft when the hydraulic rod contracts by rotating the bucket rotation shaft by a predetermined angle. It is characterized in that a transmission mechanism is provided.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of a clam shell having a scattering prevention mechanism according to the present invention will be described below with reference to the drawings.

FIG. 1 shows a clamshell according to a first embodiment of the present invention.

As shown in FIG. 1, the clamshell 1 of this embodiment has a hydraulic cylinder 2 arranged substantially vertically and a hydraulic rod 3 extending and contracting downward from the hydraulic cylinder.

A bracket 4 for supporting the bucket is attached to the lower end of the hydraulic rod 3. The bucket pivot support bracket 4 is provided with a pair of bucket pivot shafts 5a and 5b for bucket pivot support. A pair of buckets 6a, which open and close to the left and right, are provided on both bucket rotating shafts 5a, 5b.
6b are rotatably attached.

Excavation claws 7a and 7b are attached to the ends of the buckets 6a and 6b which mesh with each other when the buckets 6a and 6b are opened and closed.

A bucket opening / closing support bracket 8 serving as a fulcrum for opening / closing the bucket is provided at a part of the upper end of the hydraulic cylinder 2. The bucket opening / closing support bracket 8 and the buckets 6a, 6b are composed of bucket opening / closing arms 9a, 9b.
Are linked by.

Further, the clamshell 1 of this embodiment is
One of the two bucket rotating shafts 5a and 5b (the bucket rotating shaft 5b) is provided with the bucket rotating shaft 5b to the bucket 6b.
Is rotatably attached to the tip of the cover member 10 having a shatterproof cover 10a capable of containing a meshing portion when both buckets are closed. In the present embodiment, the portion extending from the bucket rotation shaft 5b to the outside of the bucket 6b is the fan-shaped plate member 10b, but this portion may be a member of any shape in order to reduce the weight. it can.

The cover member 10 is provided with an eccentric weight 11 which will be described in more detail later.

A first pulley 13 is provided on the upper end 2a of the hydraulic cylinder 2 via a first connecting member 12. On the other hand, the bucket pivot bracket 4 includes a second connecting member 1
A second pulley 15 is provided via 4. Wire 16
And one end of the wire 16 is connected to the hydraulic cylinder upper end 2a or a member in the vicinity thereof, and is hung around the second pulley 15 and the first pulley 13, and the other end is connected to a part of the cover member 10. There is. The first connecting member 12 and the second connecting member 14 are
It works as described below, but if it is not necessary,
The first pulley 13 and the second pulley 15 can be directly attached to the upper end bucket pivot bracket 4 of the hydraulic cylinder 2, respectively.

With the above structure, when the hydraulic rod 3 extends downward from the hydraulic cylinder 2, as shown in FIG. 1, the buckets 6a, 6b and the bucket opening / closing arms 9a, 9 are formed.
Due to the connection relationship of b, the buckets 6a and 6b are opened to the left and right sides, and at the same time, the distance between the first pulley 13 and the second pulley 15 is increased, so that the cover member 10 is pulled up by the wire 16 and, as shown in FIG. It is kept at a high position where it does not interfere with excavation.

On the other hand, when the hydraulic rod 3 contracts inside the hydraulic cylinder 2, as shown in FIG. 2, the bucket pivot support bracket 4 rises to connect the buckets 6a, 6b and the bucket opening / closing arms 9a, 9b. Due to the relationship, the buckets 6a and 6b are closed, and the cover member 10 is suspended from the bucket rotation shaft 5b by the action of gravity.

The operation of the eccentric weight 11 when the cover member 10 is suspended from the bucket rotating shaft 5b will be described with reference to FIG.

FIG. 3 shows a state in which the cover member 10 is suspended from the bucket rotating shaft 5b. Cover member 10
Is suspended from the bucket rotating shaft 5b,
Since the eccentric weight 11 is provided at the right corner of the cover member 10 in the drawing, the cover member 10 swings to the left in FIG. 3 from the vertical line c passing through the center of the bucket rotation shaft 5b due to the weight of the eccentric weight 11. . The cover member 10 stands still when the weight f1 on the right side of the vertical line c passing through the center of the bucket rotating shaft 5b and the weight f2 on the left side thereof are balanced. The eccentric weight 11 is such that when the cover member 10 is in a stationary state and the center portion M of the scattering prevention cover 10a is the bucket 6
The position and weight of the a and 6b are adjusted and designed so as to be aligned substantially vertically below the meshing part.

The eccentric weight 11 may be attached at any position, and may be integrated with a part of the cover member 10 or thicken a part of the plate member.

As a result, even if the suspension position (bucket rotating shaft 5b) of the cover member 10 is located on the right side of FIG. 3 from the meshing portion of the buckets 6a and 6b, that is, a position eccentric from the bucket meshing portion. Even if it is suspended, the center portion of the scattering prevention cover 10a can be positioned directly below the bucket meshing portion in a freely suspended state. By doing so, the scattering prevention cover 1
The central part of 0a is made of an integral structural member and does not have an opening / closing part of the cover itself as in the case where a pair of double opening / closing covers is provided on the bucket, so scattering of sludge and the like from the opening / closing part is prevented. Can be completely prevented. In addition, it is preferable that the scattering prevention cover 10a has a sufficient capacity to prevent scattering of sludge or the like from the meshing portion of the bucket while the clamshell 1 is transported in the horizontal direction.

Next, the operation and effect of the clamshell 1 of this embodiment will be described by sequentially explaining the excavation work by the clamshell 1 of this embodiment.

FIG. 4A shows a state when the clamshell 1 starts excavation. As explained in FIG.
In the clamshell 1 at this time, the hydraulic rod 3 extends downward from the hydraulic cylinder 2, the buckets 6a and 6b open to the left and right sides, and the cover member 10 includes the first pulley 13 and the second pulley 1.
By the action of 5 and the wire 16, the wire is pulled up to a high position where it does not hinder the excavation.

With the buckets 6a and 6b opened in this manner, the clamshell 1 is lowered almost vertically onto the excavated ground. Clamshell 1 with buckets 6a and 6b open
When is removed to the excavation ground, the excavation claws 7a and 7b bite vertically into the ground due to the weight of the main body of the clamshell 1.

Next, as shown in FIG. 4B, the excavation claw 7
After a and 7b bite into the ground vertically, the locked state of the hydraulic cylinder 2 is released, and the hydraulic cylinder 2 is contracted by the weight of the clamshell 1. Hydraulic cylinder 2
Contracts, the buckets 6a and 6b are forcibly closed due to the connection relationship between the bucket opening / closing arms 9a and 9ba and the buckets 6a and 6b, and at this time, the excavation claws 7a and 7ba excavate the ground.

When the hydraulic cylinder 2 contracts, the distance between the first pulley 13 and the second pulley 15 shortens, the wire 16 loosens, and the cover member 10 tries to descend. However, since the radius of the cover member 10 from the bucket rotating shaft 5b is longer than that of the bucket 6b, the end of the cover member 10 hangs on the edge of the excavation hole (see FIG. 4 (b)), which hinders excavation. Never becomes.

The distance between the first pulley 13 and the second pulley 15 is gradually shortened, and the wire 16 is further loosened.
As shown in FIG. 4 (b), the second connecting member 14 that supports the sloping sideways extends the distance between the first pulley 13 and the second pulley 15 to loosen the wire 16. ,
It is possible to prevent the wire 16 from falling off.

By closing the buckets 6a and 6b,
Soil, sludge, etc. are trapped inside the buckets 6a, 6b. Next, the clamshell 1 is pulled up by a crane or the like with the buckets 6a and 6b kept closed.

FIG. 4C shows a state in which the clamshell 1 is pulled up by a crane or the like.

As shown in FIG. 4 (c), the clam shell 1
Is pulled up by a crane or the like, the cover member 10 is separated from the edge of the excavation hole, and the cover member 10 is freely suspended from the bucket rotating shaft 5b by the action of gravity. At this time, due to the action of the eccentric weight 11, the scattering prevention cover 1
The central portion of 0a is located almost directly below the meshing portion of the bucket, and it is possible to catch sludge and the like leaking from the meshing portion of the bucket and prevent it from scattering outside.

Although not shown, in this state, the clamshell 1 is transported to above the loading platform of the dump truck, and the hydraulic rod 3 is extended again there, whereby the buckets 6a and 6b are opened to remove sludge and the like inside. It can be transferred to a dump truck. When the buckets 6a and 6b are opened, the cover member 10 is also pulled up at the same time, and the scattering prevention cover 10
The sludge accumulated in the inside of a can be transferred to the dump truck.

As described above, according to the clamshell 1 of this embodiment, the cover member 10 interlocks with the opening and closing of the buckets 6a and 6b, does not impose a burden on the operator, and does not hinder the work such as excavation. Instead, it can catch sludge and the like while suspended freely. As described above, according to the present embodiment, the structure and the driving mechanism are simplified as compared with the case where the bucket has the double structure and the opening / closing type cover is provided, and the sludge is not required without any special sealing mechanism. It is possible to eliminate the problem that the oil leaks to the outside through the meshing part with the bucket and the meshing part of the openable cover.

The clamshell 1 of this embodiment uses the first pulley 13 and the second pulley 15 as an interlocking mechanism for interlocking the opening and closing of the buckets 6a, 6b and the cover member 10. The interlocking mechanism may be any interlocking mechanism used by those skilled in the art. For example, the second pulley 15 is omitted and only the first pulley 13 is used. The first pulley 13 is attached to the hydraulic cylinder upper end portion 2a or a member (first connecting member 12) connected thereto, and one end of the wire 16 is attached to the bucket. It may be connected to a part of the pivot support bracket 4 or a member in the vicinity thereof, and may be hung around the first pulley 13 to connect the other end to a part of the cover member 10 (see FIG. 5).

The interlocking mechanism is not limited to the pulley and may be a gear mechanism, or may be a combination of a pulley and a gear.

Next, another embodiment of the present invention will be described. FIG. 6 schematically shows the configuration of the clamshell 20 according to the second embodiment of the present invention. In addition, in FIG.
The same parts as those in FIG. 1 are designated by the same reference numerals, and duplicated description will be omitted.

The clam shell 20 according to the second embodiment.
Has a winch 21 instead of the first pulley 13 and the second pulley 15 of the first embodiment. In the portion where the hydraulic cylinder 2 and the hydraulic rod 3 slide relative to each other, the hydraulic rod 3
A sensor 22 is provided for detecting and measuring the expansion / contraction distance.

The winch 21 inputs from the sensor 22 a signal that detects when the hydraulic rod 3 extends a certain distance or more and outputs a command to wind the wire 16 so that the cover member 10 has a predetermined rotation angle. , Sensor 2
A control for inputting a signal that detects when the hydraulic rod 3 contracts a predetermined distance or more from 2 and outputs a wire 16 so that the cover member 10 wound up at the predetermined rotation angle is in a suspended state. Device (CPU23)
have.

The sensor 22 is, for example, the hydraulic rod 3
The magnetic sensor can detect the magnetism of a plurality of magnetic elements embedded in the magnetic sensor. The sensor 22 can detect and measure the expansion / contraction distance of the hydraulic rod 3 based on the number of passing magnetic elements.

According to the clamshell 20 of this embodiment,
In order to open the bucket rotation shafts 5a and 5b to the left and right sides, when the hydraulic rod 3 is extended long, the sensor 22 detects the extension of the hydraulic rod 3 and the CPU 23 detects the sensor 22.
When the detection signal from the above is input and is equal to or larger than a predetermined value (threshold value), the winch 21 outputs a command to wind up the cover member 10 up to a predetermined rotation angle (height). In response to this command, the winch 21 automatically winds up and holds the cover member 10 up to a predetermined rotation angle.

Next, when the clamshell 20 is lowered to the excavation ground and the hydraulic rod 3 is contracted for a long distance for excavation, the sensor 22 detects the contraction of the hydraulic rod 3 and CP
When U23 receives the detection signal from the sensor 22 and contracts more than a predetermined value (threshold value), the winch 21 outputs a command to pay out the wire 16 until the cover member 10 is suspended. In response to this command, the winch 21 automatically pays out the wire 16 of the cover member 10.

During excavation, the buckets 6a and 6b may be opened and closed small. In the case of such a small opening / closing, the expansion / contraction distance of the hydraulic rod 3 is small, and the CPU 23 does not instruct the winch 21 to open / close the cover member 10. On the other hand, when the operator operates the buckets 6a, 6b
When the opening / closing operation is performed, the expansion / contraction distance of the hydraulic rod 3 is large, and in this case, the CPU 23 commands the winch 21 to open / close the cover member 10 and automatically winds up / down the cover member 10.

According to this embodiment, the operator does not need to open and close the cover member 10 and can concentrate on excavation work.

Next, a modified example of the clamshell 20 of the second embodiment will be described. FIG. 7 shows a configuration of a clamshell 20 ′ which is a modified example of the second embodiment.

The clamshell 20 'is different from the clamshell 20 in that it has a switch 24 for unlocking the winch 21, and the sensor 22 and the CPU 23 indicate that the hydraulic rod 3 has a predetermined distance or more. It is the same as the clamshell 20 except that it detects only when it is extended.

The switch 24 is preferably provided near the operator's control panel.

According to the clam shell 20 ', when the buckets 6a and 6b are opened, the sensor 22 detects the extension of the hydraulic rod 3, and the winch 21 is moved by the winch 21.
Roll up to a specified rotation angle and fix.

After excavation, the buckets 6a and 6b are closed, and when the clam shell 20 'is pulled up to carry sludge or the like, the operator operates the switch 24, and the winch 21 unlocks by the operation signal, The wire 16 is paid out, and the cover member 10 is lowered to the state of free suspension.

In this modification, the number of operations by the operator increases by one, but normally the cover member 10 can be fixed at a high position, and the cover member 10 can be removed only when the scattering of sludge or the like is truly prevented. Can be lowered.

Of course, in the clamshells 20 and 20 ', only the winch 21 is provided, and the sensor 22 is also the CPU2.
It is also possible to omit the switch 3 and the switch 24 and completely entrust the operation of the winch 21 to the operator.

[0068]

As is clear from the above description, according to the clamshell having the scattering prevention mechanism of the present invention, it has one cover member suspended from the meshing portion of the bucket to the eccentric bucket rotating shaft. Due to the eccentric weight, when the cover member is freely suspended, the center portion of the scattering prevention cover is aligned substantially vertically below the bucket meshing portion.

According to the present invention, it is possible to completely prevent the sludge from scattering from the clam shell with a simple structure. In particular, compared to a clamshell with a double structure by providing a pair of openable and closable covers on the outside of the bucket,
Without having a special sealing mechanism on the opening and closing part of the cover,
It is possible to prevent sludge and the like from dropping through the meshing portions of the bucket and the cover.

Further, according to the clamshell of the present invention having the interlocking mechanism for interlocking the opening and closing of the bucket and the cover member, the cover member is rolled up or lowered in conjunction with the opening and closing of the cover, and depending on the working situation, It is possible to automatically prevent scattering of sludge and the like when necessary.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a clamshell according to a first embodiment of the present invention.

FIG. 2 is an explanatory view showing a closed state of the clam shell according to the first embodiment of the present invention.

FIG. 3 is an explanatory view for explaining the action of an eccentric weight according to the present invention.

FIG. 4 is a diagram showing a clamshell excavation work according to the first embodiment of the present invention in time series.

FIG. 5 is a schematic configuration diagram of a clamshell according to a modified example of the first embodiment of the present invention.

FIG. 6 is a schematic configuration diagram of a clamshell according to a second embodiment of the present invention.

FIG. 7 is a schematic configuration diagram of a clamshell according to a modified example of the second embodiment of the present invention.

FIG. 8 is a schematic configuration diagram of a conventional clamshell.

FIG. 9 is a schematic configuration diagram of a clamshell having a scattering prevention mechanism having a double structure in which an openable cover is provided on the outside of the bucket.

[Explanation of symbols]

1 clam shell 2 hydraulic cylinder 3 hydraulic rod Bracket for 4 bucket pivots 5 bucket rotation axis 6 buckets 7 drilling claw 8 Bucket open / close support bracket 9 Bucket open / close arm 10 Cover member 11 Eccentric weight 12 First connection member 13 first pulley 14 Second connection member 15 Second pulley 16 wires 20 clamshell 21 winch 22 sensors 23 CPU 24 switches

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Noshinari Noda             Ando Construction, 3-12-8 Shibaura, Minato-ku, Tokyo             Within the corporation (72) Inventor Mikio Tomita             Ando Construction, 3-12-8 Shibaura, Minato-ku, Tokyo             Within the corporation (72) Inventor Masahiro Kamiwa             Ando Construction, 3-12-8 Shibaura, Minato-ku, Tokyo             Within the corporation (72) Inventor Taki Sawa Tetsuro             Ando Construction, 3-12-8 Shibaura, Minato-ku, Tokyo             Within the corporation (72) Inventor Chikusa Shinsho             Ando Construction, 3-12-8 Shibaura, Minato-ku, Tokyo             Within the corporation F term (reference) 3F004 EA36 NA08 PA06 PB06 PC30                 3F204 AA09 BA09 CA07 GA01

Claims (8)

[Claims] 1. A bucket pivot support bracket is provided at a lower end of the hydraulic rod, the bracket having a hydraulic cylinder arranged substantially vertically and a hydraulic rod extending and contracting downward from the hydraulic cylinder. In a clamshell in which a pair of bucket pivot shafts for pivoting a bucket are provided on a bracket, and a pair of buckets that open and close to the left and right are suspended from the bucket rotation shaft, one of the bucket rotation shafts is A cover member that extends to the outside of the bucket and is rotatably attached to a tip end of the cover member is provided with a scattering prevention cover that can include a meshing portion when both buckets are closed. When suspended on the bucket rotating shaft, the central portion of the scattering prevention cover is aligned substantially vertically below the meshing portion of the bucket. Clam shell having a scattering prevention mechanism, characterized in that a eccentric weight to. 2. A first pulley is provided on an upper end portion of the hydraulic cylinder or a member connected to the upper end portion of the hydraulic cylinder, and a wire whose one end is connected to a portion of the bucket pivot support bracket or a member in the vicinity thereof is provided. The other end is connected to a part of the cover member by being wound around the first pulley, and when the hydraulic rod is extended, the cover member is rotated about the bucket rotation axis by a predetermined angle, and the hydraulic rod is contracted. The cover member is sometimes configured to be suspended from the bucket rotating shaft.
A clam shell having a scattering prevention mechanism described in 1. 3. A first pulley is provided on the upper end of the hydraulic cylinder or a member connected to the upper end of the hydraulic cylinder, and a second pulley is provided on the bucket pivot support bracket or a member connected thereto. When a wire having one end connected to an upper end portion or a part of a member in the vicinity thereof is wound around the second pulley and the first pulley to connect the other end to a part of the cover member and the hydraulic rod extends. The cover member is rotated about the bucket rotation shaft by a predetermined angle, and the cover member is suspended from the bucket rotation shaft when the hydraulic rod contracts. A clamshell having the scattering prevention mechanism according to Item 1. 4. An electric winch is provided on an upper end of the hydraulic cylinder or a member connected to the upper end of the hydraulic cylinder, and a wire wound by the electric winch and fed out is connected to a part of the cover member. A clamshell having the shatterproof mechanism according to claim 1. 5. A sensor for detecting the expansion / contraction distance of the hydraulic rod is provided on either one of the hydraulic cylinder and the hydraulic rod, and the winch outputs a signal from the sensor that the extension of the hydraulic rod is detected for a certain distance or more. Input,
The clamshell having a scattering prevention mechanism according to claim 4, further comprising a management device that outputs a command to wind up the wire so that the cover member has a predetermined rotation angle. 6. The winch receives a signal from the sensor, which detects that the hydraulic rod has contracted for a certain distance or more, and holds the wire until the cover member wound up at the predetermined rotation angle is in a suspended state. 6. A management device that outputs a command to send out is provided.
A clam shell having a scattering prevention mechanism described in 1. 7. The winch inputs an operation signal of a switch provided on an operation panel of an operator, and pays out the wire until the cover member wound up at the predetermined rotation angle is in a suspended state. Claim 5
A clam shell having a scattering prevention mechanism described in 1. 8. Between the hydraulic rod and the cover member,
When the hydraulic rod extends, the cover member rotates a predetermined angle about the bucket rotation shaft, and when the hydraulic rod contracts, the cover member is suspended from the bucket rotation shaft. The clamshell having a scattering prevention mechanism according to claim 1, further comprising a power transmission mechanism that links expansion and contraction of the hydraulic rod with rotation of the cover member.