JP3929792B2 - Clamshell with anti-scattering mechanism - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a clam shell that is an excavator excavator that excavates by holding a suspended bucket that opens to the left and right, and in particular, while carrying dirt, sand, mud, etc. while transporting the bucket. The present invention relates to a clamshell having a scattering prevention mechanism for preventing dirt and the like from scattering.
[0002]
[Prior art]
A conventional clamshell is shown in FIG.
[0003]
The clamshell 30 has a pair of suspended buckets 31a and 31b that open to the left and right. With the buckets 31a and 31b being opened, the excavation claws 32a and 32b are pushed into the ground on the bottom of the excavation mine, so that the excavation claws 32a and 32b bite into the ground due to the weight of the clamshell body. Subsequently, by forcibly closing the buckets 31a and 31b, soil, mud, and the like are confined in the bucket, and a part of the ground is excavated.
[0004]
Then, the buckets 31a and 31b are completely closed, and the clamshell body is hoisted by a hoist while holding the soil, sand, mud, etc. in the buckets 31a and 31b, transported in a horizontal direction, and crumbed on a loading platform such as a dump truck. The shell is positioned, and the buckets 31a and 31b are opened to transfer the soil, mud and the like inside the dump truck.
[0005]
By repeating the above operations, excavation and excavation work can be carried out.
[0006]
[Problems to be solved by the invention]
However, in the conventional clamshell, when the clamshell bucket is closed, a slight gap is formed in the meshing portion of both buckets, and soil, sand, mud, etc. may fall from this gap. In particular, in the case of sludge containing a lot of moisture, the amount of falling increases.
[0007]
When the clamshell is transported toward a dump truck bed or the like while the bucket is holding soil, sand, mud, etc., the fall of the soil, sand, mud, etc. continues. For this reason, dirt, sludge, etc. are scattered on the work site of the clamshell conveyance path, and the cleanliness of the work site is significantly impaired.
[0008]
Conventionally, for the scattering of soil and sludge as described above, the work site has been manually cleaned at regular time intervals, but this cleaning has taken a lot of time and labor. Further, although the work site could be cleaned by cleaning, it was not preferable from the viewpoint of the work environment because it was not possible to avoid contamination of the work site until cleaning.
[0009]
On the other hand, in order to solve the problem of sludge and the like falling from the meshing portion of the bucket described above, it is conceivable to provide an openable / closable cover for preventing scattering from the outside of the bucket. FIG. 9 shows a clamshell having a scattering prevention mechanism provided with this double-structured openable cover.
[0010]
However, the double structure of the bucket requires a mechanism for driving the outer opening / closing cover, and there is a problem that the entire apparatus becomes complicated and large. Even when the open / close cover is provided, there remains a problem that sludge passes through the meshing portion of the inner excavation bucket and falls from the meshing portion of the outer open / close cover.
[0011]
Then, the subject which this invention tends to solve is providing the clamshell which has a scattering prevention mechanism which can prevent that sludge etc. fall from the meshing part of a bucket with simple structure.
[0014]
[Means for Solving the Problems]
The clamshell having the scattering prevention mechanism according to the present invention is
A hydraulic cylinder disposed substantially vertically and a hydraulic rod extending and contracting downward from the hydraulic cylinder; a bracket for supporting the bucket pivot at a lower end of the hydraulic rod; and a pair of buckets on the bucket pivot bracket In a clamshell in which a bucket rotating shaft for pivot support is provided, and a pair of buckets that open and close to the bucket rotating shaft are suspended,
A cover member provided with any one of the bucket rotation shafts, including a scattering prevention cover that extends from the bucket rotation shaft to the outside of the bucket and includes a meshing portion when both buckets are closed at the front end portion thereof. An eccentric weight for aligning the center of the anti-scatter cover substantially vertically below the engagement portion of the bucket when the cover member is suspended from the bucket rotation shaft. Provided,
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 wire having one end connected to a part of the bracket for supporting the pivot of the bucket or the vicinity thereof is hung on the first pulley. Rotate to connect the other end to a part of the cover member, and when the hydraulic rod is extended, the cover member rotates a predetermined angle around the bucket rotation axis, and when the hydraulic rod contracts, the cover member Is configured to be suspended from the bucket rotation shaft.
[0015]
In addition, the clamshell having a scattering prevention mechanism according to the present invention,
A hydraulic cylinder disposed substantially vertically and a hydraulic rod extending and contracting downward from the hydraulic cylinder; a bracket for supporting the bucket pivot at a lower end of the hydraulic rod; and a pair of buckets on the bucket pivot bracket In a clamshell in which a bucket rotating shaft for pivot support is provided, and a pair of buckets that open and close to the bucket rotating shaft are suspended,
A cover member provided with any one of the bucket rotation shafts, including a scattering prevention cover that extends from the bucket rotation shaft to the outside of the bucket and includes a meshing portion when both buckets are closed at the front end portion thereof. An eccentric weight for aligning the center of the anti-scatter cover substantially vertically below the engagement portion of the bucket when the cover member is suspended from the bucket rotation shaft. Provided,
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, a second pulley is provided on the bucket pivot bracket or a member connected thereto, and the upper end of the hydraulic cylinder or the vicinity thereof A wire having one end connected to a part of the member is hung around the second pulley and the first pulley, the other end is connected to a part of the cover member, and when the hydraulic rod is extended, the cover member is The cover member is configured to rotate about a predetermined angle around the bucket rotation shaft so that the cover member is suspended from the bucket rotation shaft when the hydraulic rod contracts.
[0016]
According to the present invention, it has one cover member suspended from the bucket rotation shaft at a position eccentric from the bucket meshing portion, and the center of the anti-scattering cover is made substantially vertical to the bucket meshing portion by the action of the eccentric weight. It can be located below and can receive sludge and the like falling from the bucket meshing portion.
Further, according to the clamshell, the bucket and the cover member are opened and closed in conjunction with each other by the action of the pulley, so that the burden on the operator's operation can be reduced.
[0017]
In addition, the clamshell having a scattering prevention mechanism according to the present invention,
A hydraulic cylinder disposed substantially vertically and a hydraulic rod extending and contracting downward from the hydraulic cylinder; a bracket for supporting the bucket pivot at a lower end of the hydraulic rod; and a pair of buckets on the bucket pivot bracket In a clamshell in which a bucket rotating shaft for pivot support is provided, and a pair of buckets that open and close to the bucket rotating shaft are suspended,
A cover member provided with any one of the bucket rotation shafts, including a scattering prevention cover that extends from the bucket rotation shaft to the outside of the bucket and includes a meshing portion when both buckets are closed at the front end portion thereof. An eccentric weight for aligning the center of the anti-scatter cover substantially vertically below the engagement portion of the bucket when the cover member is suspended from the bucket rotation shaft. Provided,
An electric winch is provided on the upper end of the hydraulic cylinder or a member connected to the upper end of the hydraulic cylinder, and the electric winch is wound up and connected to a part of the cover member.
[0018]
A sensor for detecting the expansion / contraction distance of the hydraulic rod is provided in one of the hydraulic cylinder and the hydraulic rod, and the winch inputs a signal from the sensor that the hydraulic rod has been extended a certain distance or more, and a cover member It is possible to have a management device that outputs a command to wind up the wire so that the angle becomes a predetermined rotation angle.
[0019]
According to this clamshell, the sensor can detect the expansion and contraction of the hydraulic rod, detect the operation of opening the bucket wide, and wind up the cover member accordingly.
[0020]
The winch receives a signal from the sensor that the hydraulic rod has contracted more than a certain distance, and outputs a command to feed the wire until the cover member wound up to the predetermined rotation angle is suspended. A management device can be provided.
[0021]
According to this clamshell, the sensor can detect the expansion and contraction of the hydraulic rod, and can detect the operation of opening and closing the bucket to a large extent, and the cover member can be rolled up and down accordingly.
[0022]
The winch can input an operation signal of a switch provided on an operation panel of an operator and feed the wire until the cover member wound up at the predetermined rotation angle is in a suspended state.
[0023]
According to this clamshell, in a normal operation, the cover member can be held in a rolled-up state, and the cover member can be lowered by an operator's switch operation only when the cover member is truly needed.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of a clamshell having a scattering prevention mechanism according to the present invention will be described below with reference to the drawings.
[0026]
FIG. 1 shows a clamshell according to a first embodiment of the present invention.
[0027]
As shown in FIG. 1, the clamshell 1 of the present embodiment has a hydraulic cylinder 2 disposed substantially vertically and a hydraulic rod 3 extending and contracting downward from the hydraulic cylinder.
[0028]
A bracket 4 for supporting the bucket is attached to the lower end of the hydraulic rod 3. The bucket pivot bracket 4 is provided with a pair of bucket rotation shafts 5a and 5b for bucket pivot support. A pair of buckets 6a and 6b that open and close to the left and right are rotatably attached to both bucket rotation shafts 5a and 5b.
[0029]
Excavation claws 7a and 7b are attached to ends engaged with each other when the buckets 6a and 6b are opened and closed.
[0030]
A bucket opening / closing support bracket 8 serving as a fulcrum for opening / closing the bucket is provided at a part from the upper end of the hydraulic cylinder 2. The bucket opening / closing support bracket 8 and the buckets 6a, 6b are connected by bucket opening / closing arms 9a, 9b.
[0031]
Furthermore, the clamshell 1 of the present embodiment extends to one of the two bucket rotation shafts 5a and 5b (bucket rotation shaft 5b) from the bucket rotation shaft 5b to the outside of the bucket 6b, and has both buckets at its tip. The cover member 10 provided with the anti-scattering cover 10a capable of including the meshing portion when the is closed is rotatably attached. In the present embodiment, the portion extending from the bucket rotating shaft 5b to the outside of the bucket 6b is composed of a fan-shaped plate member 10b. However, this portion may be a member having an arbitrary shape for weight reduction. it can.
[0032]
The cover member 10 is provided with an eccentric weight 11 which will be described in more detail later.
[0033]
A first pulley 13 is provided on the upper end 2 a of the hydraulic cylinder 2 via a first connecting member 12. On the other hand, the bucket pivot support bracket 4 is provided with a second pulley 15 via a second connecting member 14. It has a wire 16, one end of the wire 16 is connected to the hydraulic cylinder upper end 2 a or a member in the vicinity thereof, is wound around the second pulley 15 and the first pulley 13, and the other end is connected to a part of the cover member 10. is doing. The first connecting member 12 and the second connecting member 14 have an action as described later. If not necessary, the first pulley 13 and the second pulley 15 are respectively used for pivotal support of the upper end bucket of the hydraulic cylinder 2. It can be attached directly to the bracket 4.
[0034]
With the above configuration, when the hydraulic rod 3 extends downward from the hydraulic cylinder 2, as shown in FIG. 1, the buckets 6a and 6b open to the left and right sides due to the connection relationship between the buckets 6a and 6b and the bucket open / close arms 9a and 9b. At the same time, as the distance between the first pulley 13 and the second pulley 15 becomes longer, the cover member 10 is pulled up by the wire 16 and is held at a high position where there is no hindrance to excavation as shown in FIG.
[0035]
On the other hand, when the hydraulic rod 3 contracts into the hydraulic cylinder 2, as shown in FIG. 2, the bucket pivot bracket 4 is raised, and the bucket 6a, 6b and the bucket opening / closing arms 9a, 9b are connected by the connection relationship. 6a and 6b are closed, and the cover member 10 is suspended from the bucket rotating shaft 5b by the action of gravity.
[0036]
Here, 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.
[0037]
FIG. 3 shows a state where the cover member 10 is suspended from the bucket rotation shaft 5b. When the cover member 10 is suspended from the bucket rotating shaft 5b, the eccentric weight 11 is provided at the right corner of the cover member 10 in the figure, and therefore the cover member 10 is It swings to the left in FIG. 3 from a vertical line c passing through the center of the rotating shaft 5b. The cover member 10 stops at a position where the weight f1 on the right side and the weight f2 on the left side of the vertical line c passing through the center of the bucket rotating shaft 5b are balanced. The eccentric weight 11 has its position and weight adjusted so that the stationary state of the cover member 10 is aligned with the center portion M of the anti-scatter cover 10a substantially vertically below the meshing portions of the buckets 6a and 6b. Designing.
[0038]
The eccentric weight 11 can be attached at any position, and includes a case where the eccentric weight 11 is integrated with a part of the cover member 10 or a part of the plate is thickened.
[0039]
Thereby, 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, it is suspended from the position eccentric from the bucket meshing portion. Even in this case, the center portion of the anti-scattering cover 10a can be positioned directly below the bucket meshing portion in a freely suspended state. By doing so, the center part of the anti-scattering cover 10a 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 opening / closing covers are provided on the bucket in a double manner. Scattering of sludge and the like from the opening / closing portion can be completely prevented. In addition, it is preferable that the scattering prevention cover 10a has a capacity | capacitance sufficient to prevent scattering of the sludge etc. from the meshing part of a bucket, while conveying the clam shell 1 in a horizontal direction.
[0040]
Next, the operation and effect of the clamshell 1 of the present embodiment will be described by describing the excavation work by the clamshell 1 of the present embodiment over time.
[0041]
FIG. 4A shows a state when the clamshell 1 starts excavation. As described with reference to FIG. 1, the clamshell 1 at this time has the hydraulic rod 3 extending downward from the hydraulic cylinder 2, the buckets 6a and 6b open to the left and right sides, and the cover member 10 being the first pulley 13 and the second pulley. By the action of 15 and the wire 16, it is pulled up to a high position where there is no hindrance to excavation.
[0042]
With the buckets 6a and 6b thus opened, the clamshell 1 is lowered almost vertically onto the excavation ground. When the clamshell 1 is lowered to the excavation ground with the buckets 6a and 6b opened, the excavation claws 7a and 7b bite into the ground vertically due to the weight of the clamshell 1 main body.
[0043]
Next, as shown in FIG. 4B, after the excavation claws 7 a and 7 b bite into the ground vertically, the hydraulic cylinder 2 is unlocked, and the hydraulic cylinder 2 is contracted by the weight of the clamshell 1. When the hydraulic cylinder 2 contracts, the buckets 6a and 6b are forcibly closed due to the connection relationship between the bucket open / close arms 9a and 9ba and the buckets 6a and 6b, and the excavation claws 7a and 7ba excavate the ground.
[0044]
When the hydraulic cylinder 2 contracts, the distance between the first pulley 13 and the second pulley 15 is shortened, the wire 16 is loosened, and the cover member 10 is about to descend. However, since the radius of the cover member 10 from the bucket rotation shaft 5b is longer than that of the bucket 6b, the end of the cover member 10 is hooked on the edge of the excavation hole (see FIG. 4B), which hinders excavation. It will never be.
[0045]
The distance between the first pulley 13 and the second pulley 15 is gradually shortened, and the wire 16 is further loosened, but the second connecting member 14 that supports the second pulley 15 is laterally moved as shown in FIG. By falling, the distance between the first pulley 13 and the second pulley 15 can be increased, the wire 16 can be loosened, and the wire 16 can be prevented from falling off.
[0046]
By closing the buckets 6a and 6b, soil, sludge and the like are confined in the buckets 6a and 6b. Next, the clamshell 1 is pulled up with a crane or the like while the buckets 6a and 6b are closed.
[0047]
FIG. 4C shows a state where the clamshell 1 is lifted by a crane or the like.
[0048]
As shown in FIG. 4C, when the clam shell 1 is pulled up with 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 rotation shaft 5b by the action of gravity. It becomes a state. At this time, due to the action of the eccentric weight 11, the central portion of the anti-scattering cover 10a is located almost directly below the engaging portion of the bucket, and the sludge that leaks from the engaging portion of the bucket is received and prevented from scattering outside. can do.
[0049]
Although not shown, in such a state, the clamshell 1 is transported above the dump truck bed and the hydraulic rod 3 is extended again to open the buckets 6a and 6b, thereby transferring the sludge and the like inside the dump truck. Can be listed. When the buckets 6a and 6b are opened, the cover member 10 is also lifted at the same time, and sludge and the like accumulated in the scattering prevention cover 10a can be transferred to the dump truck.
[0050]
Thus, according to the clamshell 1 of the present embodiment, the cover member 10 is interlocked with the opening and closing of the buckets 6a and 6b, does not place a burden on the operator, and does not hinder work such as excavation, Sludge etc. can be received in the state suspended freely. As described above, according to the present embodiment, the structure and the drive mechanism are simplified and sludge is not required as compared with the case where the bucket has a double structure and an openable cover is provided. Can be prevented from leaking outside through the meshing portion of the bucket and the meshing portion of the openable cover.
[0051]
In addition, although the clamshell 1 of this embodiment uses the 1st pulley 13 and the 2nd pulley 15 as an interlocking mechanism which interlocks opening and closing of the buckets 6a and 6b and the cover member 10, as such an interlocking mechanism, Any interlocking mechanism used by those skilled in the art can be used. For example, the second pulley 15 is omitted and only the first pulley 13 is used. The first pulley 13 is attached to the upper end 2a of the hydraulic cylinder 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 hung around the first pulley 13 to connect the other end to a part of the cover member 10 (see FIG. 5).
[0052]
Further, the interlocking mechanism can use not only a pulley but also a gear mechanism, or a combination of a pulley and a gear.
[0053]
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 FIG. 6, the same parts as those in FIG.
[0054]
The clamshell 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. A sensor 22 for detecting and measuring the extension / contraction distance of the hydraulic rod 3 is provided at a portion where the hydraulic cylinder 2 and the hydraulic rod 3 slide relative to each other.
[0055]
The winch 21 inputs a signal from the sensor 22 that detects when the hydraulic rod 3 has extended 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. A control device that inputs a signal that detects when the hydraulic rod 3 has contracted more than a certain distance from the shaft and outputs a command to unwind the wire 16 so that the cover member 10 wound up to the predetermined rotation angle is suspended. (CPU 23).
[0056]
The sensor 22 can be, for example, a magnetic sensor that detects the magnetism of a plurality of magnetic elements embedded in the hydraulic rod 3. The sensor 22 can detect and measure the expansion / contraction distance of the hydraulic rod 3 based on the number of passing magnetic elements.
[0057]
According to the clamshell 20 of the present embodiment, in order to open the bucket rotation shafts 5a and 5b to the left and right sides, when the hydraulic rod 3 is elongated, the sensor 22 detects the extension of the hydraulic rod 3, and the CPU 23 detects the sensor. If the detection signal from 22 is input and if it is equal to or greater than a predetermined value (threshold value), a command for causing the winch 21 to wind up the cover member 10 to a predetermined rotation angle (height) is output. By this command, the winch 21 automatically winds and holds the cover member 10 to a predetermined rotation angle.
[0058]
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 the CPU 23 inputs a detection signal from the sensor 22. If the contraction is equal to or greater than a predetermined value (threshold value), a command for feeding the wire 16 is output to the winch 21 until the cover member 10 is suspended. By this command, the winch 21 automatically feeds the wire 16 of the cover member 10.
[0059]
During excavation, the buckets 6a and 6b may open and close small. In such a small opening / closing, the expansion / contraction distance of the hydraulic rod 3 is small, and the CPU 23 does not command the winch 21 to open / close the cover member 10. On the other hand, when the operator opens / closes the buckets 6a and 6b, the expansion / contraction distance of the hydraulic rod 3 is large. In this case, the CPU 23 instructs the winch 21 to open / close the cover member 10 and automatically covers the cover member 10. Roll up and down.
[0060]
According to the present embodiment, it is not necessary for the operator to operate opening and closing of the cover member 10, and it is possible to concentrate on excavation work.
[0061]
Next, a modification of the clamshell 20 of the second embodiment will be described.
FIG. 7 shows a configuration of a clamshell 20 ′, which is a modification of the second embodiment.
[0062]
The clamshell 20 'differs from the clamshell 20 in that it has a switch 24 for unlocking the winch 21, and the sensor 22 and the CPU 23 are used when the hydraulic rod 3 extends more than a predetermined distance. It is the same as the clamshell 20 except that only the detection is performed.
[0063]
The switch 24 is preferably provided in the vicinity of the operator's operation panel.
[0064]
According to the clamshell 20 ', when the buckets 6a and 6b are opened, the extension of the hydraulic rod 3 is detected by the sensor 22, and the winch 21 winds and fixes the cover member 10 to a predetermined rotation angle.
[0065]
When excavation is completed, the buckets 6a and 6b are closed, and the clamshell 20 'is lifted to transport sludge and the like, the operator operates the switch 24, and the winch 21 releases the lock by the operation signal, and the wire 16 is It extends and lowers the cover member 10 to the state of free suspension.
[0066]
In this modification, the operator's operation is increased by one, but normally the cover member 10 can be fixed at a high position, and the cover member 10 can be lowered only to prevent the sludge from splashing. it can.
[0067]
Of course, only the winch 21 is provided in the clamshells 20 and 20 ′, and the sensor 22, CPU 23 and switch 24 are omitted, and the operation of the winch 21 can be completely left to the operator.
[0068]
【The invention's effect】
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 bucket rotating shaft eccentric from the meshing part of the bucket, and by 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 engagement portion.
[0069]
According to the present invention, it is possible to completely prevent sludge from scattering from the clamshell with a simple configuration. In particular, compared with a clam shell having a double structure by providing a pair of openable openable / closable covers on the outside of the bucket, the engagement portion of the bucket and the cover does not have a special sealing mechanism at the openable / closable portion of the cover. Sludge etc. can be prevented from falling through.
[0070]
Further, according to the clamshell of the present invention having an interlocking mechanism for interlocking the opening and closing of the bucket and the cover member, the cover member is rolled up or down in conjunction with the opening and closing of the cover. It is possible to automatically prevent the sludge from scattering.
[Brief description of the 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 state in which the clamshell is closed according to the first embodiment of the present invention.
FIG. 3 is an explanatory diagram for explaining the operation of an eccentric weight according to the present invention.
FIG. 4 is a diagram showing the crumb shell 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 modification 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 modification 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 clam shell having an anti-scattering mechanism in which an openable cover is provided on the outside of the bucket to form a double structure.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Clamshell 2 Hydraulic cylinder 3 Hydraulic rod 4 Bucket pivot bracket 5 Bucket rotating shaft 6 Bucket 7 Excavation claw 8 Bucket opening / closing support bracket 9 Bucket opening / closing arm 10 Cover member 11 Eccentric weight 12 First connecting member 13 First pulley 14 First 2 connecting member 15 second pulley 16 wire 20 clamshell 21 winch 22 sensor 23 CPU
24 switch

Claims (6)

A hydraulic cylinder disposed substantially vertically and a hydraulic rod extending and contracting downward from the hydraulic cylinder; a bracket for supporting the bucket pivot at a lower end of the hydraulic rod; and a pair of buckets on the bucket pivot bracket In a clamshell in which a bucket rotating shaft for pivot support is provided, and a pair of buckets that open and close to the bucket rotating shaft are suspended,
A cover member provided with any one of the bucket rotation shafts, including a scattering prevention cover that extends from the bucket rotation shaft to the outside of the bucket and includes a meshing portion when both buckets are closed at the front end portion thereof. An eccentric weight for aligning the center of the anti-scatter cover substantially vertically below the engagement portion of the bucket when the cover member is suspended from the bucket rotation shaft. Provided,
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 wire having one end connected to a part of the bracket for supporting the pivot of the bucket or the vicinity thereof is hung on the first pulley. Rotate to connect the other end to a part of the cover member, and when the hydraulic rod is extended, the cover member rotates a predetermined angle around the bucket rotation axis, and when the hydraulic rod contracts, the cover member A clamshell having a scattering prevention mechanism, characterized in that is configured to be suspended from the bucket rotation shaft. A hydraulic cylinder disposed substantially vertically and a hydraulic rod extending and contracting downward from the hydraulic cylinder; a bracket for supporting the bucket pivot at a lower end of the hydraulic rod; and a pair of buckets on the bucket pivot bracket In a clamshell in which a bucket rotating shaft for pivot support is provided, and a pair of buckets that open and close to the bucket rotating shaft are suspended,
A cover member provided with any one of the bucket rotation shafts, including a scattering prevention cover that extends from the bucket rotation shaft to the outside of the bucket and includes a meshing portion when both buckets are closed at the front end portion thereof. An eccentric weight for aligning the center of the anti-scatter cover substantially vertically below the engagement portion of the bucket when the cover member is suspended from the bucket rotation shaft. Provided,
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, a second pulley is provided on the bucket pivot bracket or a member connected thereto, and the upper end of the hydraulic cylinder or the vicinity thereof A wire having one end connected to a part of the member is hung around the second pulley and the first pulley, the other end is connected to a part of the cover member, and when the hydraulic rod is extended, the cover member is A crumb having an anti-scattering mechanism configured to rotate about a predetermined angle about the bucket rotation shaft and to be in a state where the cover member is suspended from the bucket rotation shaft when the hydraulic rod contracts shell. A hydraulic cylinder disposed substantially vertically and a hydraulic rod extending and contracting downward from the hydraulic cylinder; a bracket for supporting the bucket pivot at a lower end of the hydraulic rod; and a pair of buckets on the bucket pivot bracket In a clamshell in which a bucket rotating shaft for pivot support is provided, and a pair of buckets that open and close to the bucket rotating shaft are suspended,
A cover member provided with any one of the bucket rotation shafts, including a scattering prevention cover that extends from the bucket rotation shaft to the outside of the bucket and includes a meshing portion when both buckets are closed at the front end portion thereof. An eccentric weight for aligning the center of the anti-scatter cover substantially vertically below the engagement portion of the bucket when the cover member is suspended from the bucket rotation shaft. Provided,
An electric winch is provided on a member connected to the upper end portion of the hydraulic cylinder or the upper end portion of the hydraulic cylinder, and a scattering prevention mechanism is provided in which the electric winch is wound up and connected to a part of the cover member. Clamshell.   A sensor for detecting the expansion / contraction distance of the hydraulic rod is provided in one of the hydraulic cylinder and the hydraulic rod, and the winch inputs a signal from the sensor that the hydraulic rod has been extended a certain distance or more, and a cover member The clamshell having a scattering prevention mechanism according to claim 3, further comprising: a management device that outputs a command to wind the wire so that a predetermined rotation angle is obtained.   The winch receives a signal from the sensor that the hydraulic rod has contracted more than a certain distance, and outputs a command to feed the wire until the cover member wound up to the predetermined rotation angle is suspended. The clamshell having a scattering prevention mechanism according to claim 4, further comprising a management device.   5. The winch receives an operation signal of a switch provided on an operation panel of an operator, and feeds the wire until the cover member wound up at the predetermined rotation angle is in a suspended state. A clamshell having the scattering prevention mechanism described above.

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