JP2706046B2 - Hydraulic grab bucket - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil tank provided in a hydraulic grab bucket having a hydraulic cylinder for opening and closing a pair of bucket shells pivotally supported on a center frame suspended by wires or the like. It relates to a drain structure.

[0002]

2. Description of the Related Art Conventionally, in a hydraulic grab bucket having a hydraulic pressure generating device in a bucket, an oil tank for storing hydraulic oil is essential. The provision of the oil tank requires a drain structure for discharging moisture and dust mixed in the oil tank. In this type of hydraulic grab bucket, a drain plug is provided at the bottom of an oil tank to drain moisture or dust accumulated at the bottom.

[0003]

However, in such a conventional drain structure of a hydraulic grab bucket, when the size of the bucket is increased, the amount of oil used for the hydraulic cylinder becomes enormous and the capacity of the oil tank becomes enormous. For example, 300
Ton-grade hydraulic grab buckets use up to about 20,000 liters of oil. When removing water and dust mixed in from this large amount of oil, all the pressure heads in the oil tank formed at the bottom work, and a large amount of oil is discharged at once, which is very dangerous.

An object of the present invention is to provide a hydraulic grab bucket capable of safely discharging water and dust accumulated in an oil tank in view of such a conventional hydraulic grab bucket.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the gist of the present invention is to provide a pair of bucket shells supported by a center frame suspended by wires or the like so as to be openable and closable with a horizontal shaft. A hydraulic cylinder that opens and closes the bucket shell, a hydraulic device that generates a hydraulic pressure to be transmitted to the hydraulic cylinder, and a hydraulic grab bucket including a control mechanism that controls the expansion and contraction operation by transmitting the generated hydraulic pressure to the hydraulic cylinder. An oil tank for storing hydraulic oil for driving the hydraulic cylinder, a funnel-shaped drain pool formed at the bottom of the oil tank, one end of which opens into the drain pool, and the other end of which is outside the oil tank and above the oil level. And a stop valve provided at a portion of the drain pipe protruding from the oil tank.

[0006] Further, the inside of an oil tank provided in the hydraulic grab bucket may be pressurized. Further, a suction device is provided at the other end of the drain pipe opened to the outside of the oil tank.

[0007]

The hydraulic grab bucket according to the present invention has a drain pipe having one end opened in a funnel-shaped drain reservoir formed at the bottom of the oil tank and the other end opened above the oil level outside the oil tank. Therefore, when draining water or dust from the drain reservoir, the operation can be performed safely without the pressure head in the oil tank.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is an overall front view of a hydraulic grab bucket according to one embodiment of the present invention, FIG. 2 is a partially cutaway front view showing a hydraulic grab bucket according to one embodiment of the present invention, and FIG. It is a partially cutaway front view of a shell.

As shown in FIG. 1, the hydraulic grab bucket G is suspended by a hanging fitting 1 connected to a wire 9 from a crane boom. In addition, the bucket body 10
A center frame 20 having a watertightly closed chamber 30 therein and accommodating a hydraulic device 40, a pair of bucket shells 50 pivotally supported by the center frame 20 so as to be freely openable and closable, and mounted on top of each bucket shell 50. And a hydraulic cylinder 60 for opening and closing the bucket shell 50.

As shown in FIG. 2, the center frame 20 has a rigid steel structure, and has a wire 9 extending upward.
Mounting bracket 21 and bucket shell 5 at the four corners of the hem.
Shell mounting part 23 provided with a pivot 22 for pivoting
Is provided. A watertightly closed chamber 30 for housing the hydraulic device 40 is formed in the center of the frame.

The watertightly closed chamber 30 has a welded structure at its four circumferences and at the bottom, and is appropriately reinforced so that it can withstand high water pressure. However, only the upper part can be opened to be opened at the time of periodic inspection. The upper lid 31 is provided with a watertight means by a packing 32. The lower half of the watertightly closed chamber 30 constitutes an oil tank 41 of the hydraulic device 40 as it is, and the oil tank 41 and the upper space are sealed and partitioned by an oil tank upper plate 42 and an oil tank packing 43.

The bottom of the oil tank 41 is funnel-shaped toward the center, and a drain reservoir 46 is formed at the lowermost end. Also, one end opens into the drain reservoir 46,
A drain pipe 47 having the other end opened above the oil tank upper plate 42 of the oil tank 41 is provided.
The stop valve 48 is connected to a portion above the oil tank upper plate 42 of No. 7. Further, a suction device 49 is connected to a distal end of the drain pipe 47.

As shown in FIG. 3, the bucket shell 50 includes a pair of shell bodies 51 made of steel and a scooping section 52 made of cast steel for scooping earth and sand. Pin 53 for coupling with 60
Is provided with a cylinder coupling portion 54 provided with a.
Below the cylinder coupling portion 54, a bearing portion 55 for receiving the pivot 22 of the center frame 20 is provided.
Further, the shell main body 51 is provided with an equalizer 56 such that the open / close degree of both shell main bodies 51 is the same angle on the left and right. Further, a plurality of claws 57 for scraping earth and sand are alternately mounted on the tip of each scooping section 52.

The electric pump 45 is driven by a motor 44 to supply hydraulic pressure to each hydraulic cylinder 60. In the present embodiment, the electric pump 45 is of a piston type that generates a high pressure force.

The hydraulic cylinder 60 includes a cylinder cylinder 6
1, a clevis 64 having a bearing fitted to the pin 53 of the bucket shell 50 is provided at the tail of the cylinder body 61, and the tip of the bucket shell 50 is provided at the tip of the piston rod 63. A coupling member 65 having a bearing coupled to another pin 53 is attached.

Next, the draining operation of the hydraulic grab bucket configured as described above will be described. Now, when water or dust accumulates in the oil tank 41, a stop valve 48 connected to the drain pipe 47 in the watertightly closed chamber 30 is used.
Is opened, and the suction device 49 connected to the tip is operated.
Then, moisture and dust having a higher specific gravity than the oil are sucked from the drain pipe 47 together with the surrounding oil. At this time, a large amount of oil head does not reach the exit, and the oil is safe. That is,
If the drain outlet is provided at the lower end of the oil tank as in the related art, the oil is discharged at a stretch, which is dangerous. However, in such a configuration, the pressure at the outlet of the drain pipe 47 is substantially zero, and the outlet can be discharged only by the suction force of the suction device 49.

If the oil tank 41 is pressurized, the drain can be naturally discharged by opening the stop valve 48 without using the suction device 49.

[0018]

As described above, the present invention relates to a pair of bucket shells which are supported by a center frame suspended by wires or the like so as to be openable and closable with a horizontal shaft, and a hydraulic cylinder which drives the opening and closing of the bucket shells. In a hydraulic grab bucket equipped with a hydraulic device for generating hydraulic pressure to be sent to the hydraulic cylinder and a control mechanism for controlling the expansion and contraction operation by sending the generated hydraulic pressure to the hydraulic cylinder, hydraulic oil for driving the hydraulic cylinder is stored. An oil tank, a funnel-shaped drain reservoir formed at the bottom of the oil reservoir, a drain pipe having one end opened into the drain reservoir, and the other end opened above the oil level outside the oil reservoir, and A stop valve is provided at the part protruding from the oil tank, so it is safe to remove mixed water from hydraulic oil stored in a large oil tank. It is possible that.

In other words, the drain can be drained in a state where the pressure is almost zero without the head in the oil tank being applied to the head, and the operation can be performed safely.

[Brief description of the drawings]

FIG. 1 is an overall front view of a hydraulic grab bucket according to an embodiment of the present invention.

FIG. 2 is a partially cutaway front view showing a hydraulic grab bucket according to one embodiment of the present invention.

FIG. 3 is a partially cutaway front view of the bucket shell.

[Explanation of symbols]

 G Hydraulic grab bucket 9 Wire 10 Bucket body 20 Center frame 21 Mounting bracket 22 Axis 23 Shell mounting part 30 Watertightly closed 31 Upper lid 32 Packing 40 Hydraulic device 41 Oil tank 42 Oil tank upper plate 43 Oil tank packing 46 Drain reservoir 47 Drain pipe 48 Stop valve 49 Suction device 50 Bucket shell 60 Hydraulic cylinder

Claims (3)

(57) [Claims] 1. A pair of bucket shells supported by a center frame suspended by wires or the like so as to be openable and closable with a horizontal shaft, a hydraulic cylinder for driving the bucket shell to open and close, and a hydraulic pressure to be sent to the hydraulic cylinder. In a hydraulic grab bucket provided with a hydraulic device and a control mechanism for controlling the expansion and contraction operation by sending generated hydraulic pressure to the hydraulic cylinder, an oil tank for storing hydraulic oil for driving the hydraulic cylinder and a bottom formed in the oil tank Funnel-shaped drain pool and one end open into the drain pool,
A hydraulic grab bucket comprising: a drain pipe having the other end opened above the oil surface outside the oil tank; and a stop valve provided at a portion of the drain pipe protruding from the oil tank. 2. The hydraulic grab bucket according to claim 1, wherein an inside of an oil tank disposed in the hydraulic grab bucket is pressurized. 3. The hydraulic grab bucket according to claim 1, wherein a suction device is provided at the other end of the drain pipe opened to the outside of the oil tank.