JP3398763B2 - 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 a grab bucket which is mainly hung on a crane such as a ship and used for loading and unloading bulk materials.

[0002]

2. Description of the Related Art Conventionally, a single rope type grab bucket operated by a crane or the like has been used for transferring loose materials such as wood chips, powdered ore and earth and sand.

As a conventional single rope type grab bucket of this type, for example, one having a structure shown in FIGS. 7 and 8 is known. This grab bucket comprises a pair of shells 2 and 2 that constitute a grab 1 and are opened and closed so as to face each other, and a lower frame 3 in which the pivot centers of the shells 2 and 2 are pivotally supported by shafts 2a and 2a. , An upper frame 5 located above the lower frame 3 and connected to the back surface of each shell 2, 2 via suspension arms 4, 4, ..., and between the upper and lower frames, a hydraulic cylinder 6 for the lower frame 3. The intermediate movable frame 7 connected through the intermediate movable frame 7, the lower end of which is fixed to the intermediate movable frame 7, and the suspension which is extended upward by being wound around pulleys provided in the intermediate movable frame 7 and the upper frame 5, respectively. A wire rope 8 for lowering and closing the grab, and a hydraulic cylinder control means for controlling the operation of the hydraulic cylinder 6 by opening and closing an oil passage communicating with the hydraulic cylinder 6. Equipped and are configured.

When the glove 1 is opened, the hydraulic cylinder control means is operated to set the hydraulic cylinder 6 in a free state so that the lower frame 3 is moved from the intermediate movable frame 7 by the weight of the shell and the lower frame 3. When the shell 2 is detached and lowered, the back surface of the shell 2 is suspended by the suspension arm 4, the position of the rotation center shaft 3a is lowered, and the glove is opened.

In the closing direction of the grab 1, the intermediate movable frame 7 is lowered by feeding the wire rope 8 downward from the open state while the hydraulic cylinder 6 is kept in the free state. Three
, The hydraulic cylinder 6 is made inextensible in this state, and the wire rope 8 is pulled up, whereby the intermediate movable frame 7 is pulled up so as to approach the upper frame 5, whereby both shells 2 and 2 close each other. It is designed to be operated in the direction.

[0006]

However, in the prior art as described above, when the intermediate movable frame is lowered while the grab is in contact with the ground during the closing operation, the ground to be ground is inclined. If this happens, the tension balance of the wire rope that suspends the intermediate movable frame will be lost, and the intermediate movable frame will rotate around the axis of the hydraulic cylinder, and will descend in the twisted state until it approaches the lower frame. Then, there is a problem that a part of the lower surface of the intermediate movable frame comes into contact with the antenna of the wireless device mounted on the lower frame and the oil supply port of the oil tank, and destroys them.

In view of the situation of the prior art as described above, the present invention is capable of suitably lowering the intermediate movable frame,
The purpose is to provide a highly safe grab bucket.

[0008]

The features of the present invention for solving the above-mentioned conventional problems and achieving the intended purpose are as follows.
A pair of shells that form a grab and are opened and closed to face each other, a lower frame that pivotally supports the rotation center of the shell, and a rear surface of each shell and a suspension arm that are located above the lower frame. And an intermediate movable frame that is between the upper and lower frames and that is connected to the lower frame via a hydraulic cylinder, and has a lower end fixed to the intermediate movable frame and the intermediate movable frame. Controlling the operation of the hydraulic cylinder by opening and closing a wire rope for hanging and grab closing, which is wound around a pulley around the frame and the upper frame and extends upward, and an oil passage communicating with the hydraulic cylinder And a lower end side of the hydraulic cylinder, the glove bucket including Rotational direction around the axis of the hydraulic cylinder is linked to a condition not to the frame,
A guide projection is provided on the outer circumference of the upper end side of the hydraulic cylinder, and a hollow portion is provided in the intermediate movable frame to allow the upper end side of the hydraulic cylinder to come in and out, and a lower side where the guide projection is guided is provided in the hollow portion. An expanded guide groove is provided, and the guide projection is relatively raised in the guide groove, so that the guide projection guides the guide projection, and when the movable frame approaches the lower frame, both of them are predetermined. It is that the angle is regulated.

It is preferable that the guide projection is formed in a U-shaped cross-section with a downward opening.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of a grab bucket according to the present invention will be described with reference to FIGS. The same parts as those in the above-mentioned conventional example are designated by the same reference numerals for description.

In the figure, 1 is a grab, 3 is a lower frame, 4 is a suspension arm, 5 is an upper frame, 7 is an intermediate movable frame, and 8 is a wire rope.

This grab bucket comprises a pair of shells 2 and 2 that constitute the glove 1 and are opened and closed facing each other, and the center of rotation of each shell 2 and 2 is a shaft 3a, as in the above-mentioned conventional example. The lower frame 3 pivotally supported by 3a, the upper frame 5 located above the lower frame 3 and connected to the back surfaces of the shells 2 and 2 via the suspension arms 4, 4 ,. And an intermediate movable frame 7 connected to the lower frame 3 via a hydraulic cylinder 6, and a pulley having a lower end fixed to the intermediate movable frame 7 and provided on the intermediate movable frame 7 and the upper frame 5, respectively. The wire rope 8 for suspending and closing the grab, which is wound around the cable and extended upward, and the movement of the hydraulic cylinder 6 by opening and closing the oil flow path communicating with the hydraulic cylinder 6. It is constituted by a hydraulic cylinder controlling means for controlling.

The grab 1 has a shaft 3 with respect to the lower frame 3.
a and 3a are respectively rotatably supported by shells 2 and 2, and in the closed state where the openings are joined to each other, the bottom is closed and a gripping space 9 in which a loose item is stored is formed. To be formed.

Further, the lower end of the suspension arm 4 is pivotally supported by the back of each shell 2, and the upper end of the suspension arm 4 is pivotally supported by the upper frame 5, so that the shells 2 and 2 are supported by the upper frame 5. Are connected in a suspended state with respect to.

An oil tank 11 and a radio signal receiver 12 are attached to the lower frame 3. In the figure, reference numeral 13 is a fuel filler port provided on the upper portion of the oil tank 11, and 14 is a receiving antenna of the wireless signal receiver.

The hydraulic cylinder 6 includes a cylindrical cylinder portion 6a, a piston 6b which is reciprocally housed in the cylinder portion 6a, and a piston rod 6 which is connected to the piston 6b and protrudes freely from the upper end of the cylinder portion 6a.
and c.

The lower end of the cylinder portion 6a is connected to the lower frame 3, and the tip end portion of the piston rod 6c is connected to the top portion of the intermediate movable frame 7 by screwing or the like, respectively.
As a result, the lower frame 3 and the intermediate movable frame 7 are connected via the hydraulic cylinder 6.

A flow path 1 communicating with the piston 6b in the vertical direction.
8 is formed, and a check valve 19 for restricting the inflow of oil from the upper side to the lower side of the piston 6b is provided in the flow path 18 thereof.

A rod-shaped piston rod 6c is provided on the piston 6b so as to project upward.

As shown in FIG. 5, the hydraulic circuit for controlling the operation of the hydraulic cylinder 6 has one end of the conduit 20 connected to the upper end of the cylinder portion 6a of the hydraulic cylinder 6, and a throttle valve 21 and a pilot check valve 22. After that, the cylinder part 6
The other end of the conduit 20 is connected to the lower end of a. Further, the lower end of the cylinder portion 6 a is communicated with the oil tank 11 via the connecting conduit 23.

The throttle valve 21 is interposed between the upper end of the cylinder portion 6a and the pilot check valve 22, and the glove 1
When releasing the cylinder part 6a from the top
a The opening speed of the glove 1 is changed by adjusting the flow rate of the oil flowing to the lower end portion.

The pilot check valve 22 is a solenoid valve 24.
When the pilot check valve 22 is closed, the oil above the piston 6b in the cylinder portion 6a is dammed to stop the hydraulic cylinder 6 from descending, and the pilot check valve 2 is opened.
When 2 is opened, oil can flow into the hydraulic cylinder 6 below the piston 6b through the conduit 20 and the hydraulic cylinder 6 becomes free.

The intermediate movable frame 7 is formed in a shape having a hollow portion 25 inside, as shown in FIGS.

Sheave cases 26, 26 are fixedly installed on the lower right side of the front surface and the lower left side of the rear surface of the intermediate movable frame 7, and pulleys 27, 27 are provided therein.

In the hollow portion 25 of the intermediate movable frame 7, the hydraulic cylinder 6 can freely expand and contract, and along the hydraulic cylinder 6, a guide groove 28 that expands downward is provided. .

A guide projection 29 is provided on the outer peripheral surface of the upper end of the cylinder portion 6a so that the guide projection 29 extends and contracts as the hydraulic cylinder 6 expands and contracts.
It is supposed to be guided by.

The guide groove 28 is a pair of groove plate members 30, 30.
Are formed in parallel with each other from the inside of the front surface and the inside of the rear surface, respectively.

The groove plate member 30 includes a straight portion 30a,
Triangular piece 30 inclined from the bottom to the center of the straight part
and b are integrally formed.

The length of the straight portion 30a is determined by the oil filler port 13
It is formed to be slightly longer than the height of objects that may come into contact with the intermediate movable frame 7, such as the antenna 14 and the antenna 14.

The guide projection 29 is formed in a substantially U-shape with its cross section opened downward, and its lateral width is substantially the same as the width of the straight portion 28a of the guide groove.

The end portion of the guide projection 29 on the cylinder side is shaped so as to be cut off in accordance with the outer peripheral surface of the cylinder portion 6a of the hydraulic cylinder 6, and a bolt hole for fixing is opened in accordance with the position of the hydraulic cylinder. The cylinder 6a is bolted to the cylinder 6a.

With this structure, when the cylinder portion 6a moves relative to the intermediate movable frame 7 and the guide projection 29 enters the straight portion 28a, both sides thereof are guided by the groove plate member 30. The rotation of the hydraulic cylinder 6 about its axis is restricted.

The upper frame 5 is formed in such a shape that the upper part of the intermediate movable frame 7 is fitted in the central portion of the upper frame 5, and pulleys 31, 31, ... Are rotatably provided on the front and rear portions of the upper frame 5, respectively.

The intermediate movable frame 7 is hung relative to the upper frame 5 by operating the wire rope 8. That is, as shown in FIG. 6, the wire rope 8 is provided on both sides of the intermediate movable frame 7.
For fixing the lower end of the wire rope 8 and winding the wire rope 8 around the pulleys 27, 27 via the pulleys 31, 31 of the upper frame 5 and extending it upward to suspend the upper end on a crane or the like. It is fixed at 32.

Next, the opening / closing operation of the grab 1 of the grab bucket and the operation of the guide projection 29 will be described.

In the initial state of the grab bucket, the grab 1 is placed with the upper, lower and intermediate movable frames in close proximity to each other.
Is closed and suspended from a crane.

At this time, the guide projection 29 is guided by the straight portion 28a of the guide groove 28, and the rotation of the hydraulic cylinder 6 in the direction around the shaft center is restricted.

When opening the glove 1, first, the radio signal receiver 12 is caused to receive a signal for opening the glove, so that an operating current flows through the solenoid valve (solenoid valve) 24, and the solenoid valve is operated only during the energization. 24 is operated to the pilot check valve opening side.

When the solenoid valve 24 operates, the pilot check valve 22 opens, and the cylinder portion 6a passes through the conduit 20.
The oil flows from the upper part to the lower part of the cylinder, and the hydraulic cylinder 6 becomes free.

As a result, the lower frame 3 has the shell 2,
2 and the lower frame 3 are separated from the intermediate movable frame 7 by the weight of the lower frame 3 and are lowered, and in the state where the back portion of the shell 2 is suspended by the suspension arm 4, the position of the rotation center shaft 3a is lowered and the glove 1 is opened. ing.

At this time, the cylinder portion 6a of the hydraulic cylinder 6 descends relatively to the guide groove 28, and the guide projection 29 also descends relative to it. And
The guide projection 29 is disengaged from the straight portion 28a and can be rotated in the direction around the axis of the hydraulic cylinder 6 by the width of the guide groove 28.

Next, the glove 1 is landed on the object with the above-mentioned open state.

In the closing direction of the grab 1, the intermediate movable frame 7 is lowered by lowering the intermediate movable frame 7 by unwinding the wire rope 8 while the hydraulic cylinder 6 is in the free state from the landing state. The hydraulic cylinder 6 is made inextensible in this state by approaching the frame 3, and then the wire rope 8 is raised so that the intermediate movable frame 7 is raised so as to approach the upper frame 5, whereby the rotation center shaft 2a, 2a rises and both shells 2 and 2 are operated so as to close each other.

At this time, the cylinder portion 6a of the hydraulic cylinder 6 moves up relative to the guide groove 28, and the guide projection 29 also moves up accordingly. Then, as the intermediate movable frame 7 approaches the upper frame 5, the guide projection 29 is guided by the portion of the triangular piece 30b of the groove plate 30 to regulate the angle, and when it reaches a predetermined position, is guided to the straight portion 28a. To be done.

Therefore, when the intermediate movable frame 7 approaches the lower frame 3, both are restricted to a predetermined angle, and the antenna 14 for the wireless device or the oil supply port 15 of the oil tank and the lower surface of the intermediate movable frame 7 come into contact with each other. It is designed to prevent it.

[0046]

EFFECTS OF THE INVENTION A pair of shells that constitute a glove and are opened and closed to face each other, a lower frame that pivotally supports the rotation center of the shell, and a lower frame that is located above the lower frame. An upper frame connected to the back via a suspension arm, an intermediate movable frame between the upper and lower frames and connected to the lower frame via a hydraulic cylinder, and a lower end fixed to the intermediate movable frame. By opening and closing the wire rope for hanging and grab closing, which is wound around the intermediate movable frame and the upper frame and extended upward by the pulley, respectively, and the oil flow path leading to the inside of the hydraulic cylinder. A grab bucket comprising a hydraulic cylinder control means for controlling the operation of the hydraulic cylinder, wherein the hydraulic cylinder The lower end side is connected to the lower frame in a state in which it cannot rotate in the direction around the shaft center of the hydraulic cylinder, and a guide projection is provided on the outer periphery of the upper end side of the hydraulic cylinder so as to project. The movable frame is provided with a hollow portion through which the upper end side of the hydraulic cylinder goes in and out, and a guide groove is formed in the hollow portion, the lower side of which is expanded to guide the guide projection, and the guide projection is provided in the guide groove. By the relative movement, the guide projections are guided by the guide groove so that when the movable frame approaches the lower frame, both are regulated to a predetermined angle. When moving relatively close to the antenna, the antennas for radio equipment and the lower surface of the intermediate movable frame do not come into contact with each other, and the antennas are destroyed. Rukoto can smoothly relative vertical movement without safety is improved.

[Brief description of drawings]

FIG. 1 is a front view showing an operating state of a grab bucket according to the present invention.

FIG. 2 is a vertical sectional view showing an intermediate movable frame in FIG.

3 is a cross-sectional view taken along the line AA in FIG.

FIG. 4 is a sectional view taken along line BB in FIG.

5 is a schematic diagram showing a hydraulic circuit for controlling the hydraulic cylinder in FIG. 1. FIG.

6 is a perspective view showing a state in which the pulley and the wire rope in FIG. 1 are wound around each other.

FIG. 7 is a front view showing a conventional grab bucket.

FIG. 8 is a side view of the above.

[Explanation of symbols]

1 grab 2 shell 3 Lower frame 4 hanging arms 5 Upper frame 6 hydraulic cylinder 6a Cylinder part 6b piston 6c piston rod 7 Intermediate movable frame 8 wire rope 9 Grasping space 11 oil tank 12 Radio signal receiver 13 Filling port 14 Receiving antenna 20 conduits 21 Throttle valve 22 Pilot check valve 23 Connection conduit 24 Solenoid valve 25 Hollow part 26 sheave cases 27 pulley 28 Guide groove 28a Straight part 29 Guide projection 30 Groove plate 30a Straight part 30b triangular piece 31 Pulley 32 suspenders

Claims (2)

(57) [Claims] 1. A pair of shells that constitute a grab and are opened and closed so as to face each other, a lower frame that pivotally supports the center of rotation of the shell, and a lower frame that is located above the lower frame. An upper frame connected to the back via a suspension arm, an intermediate movable frame between the upper and lower frames and connected to the lower frame via a hydraulic cylinder, and a lower end fixed to the intermediate movable frame. By opening and closing the wire rope for hanging and grab closing, which is wound around the intermediate movable frame and the upper frame and extended upward by the pulley, respectively, and the oil flow path leading to the inside of the hydraulic cylinder. In a grab bucket comprising a hydraulic cylinder control means for controlling the operation of the hydraulic cylinder, The lower end side is connected to the lower frame in a state in which it cannot rotate in the direction around the shaft center of the hydraulic cylinder, and a guide projection is provided on the outer periphery of the upper end side of the hydraulic cylinder so as to project. The movable frame is provided with a hollow portion through which the upper end side of the hydraulic cylinder goes in and out, and a guide groove is formed in the hollow portion, the lower side of which is expanded to guide the guide projection, and the guide projection is provided in the guide groove. A glove bucket characterized in that the guide projection is guided by the guide groove by being relatively raised so that both are restricted to a predetermined angle when the movable frame approaches the lower frame. 2. The glove bucket according to claim 1, wherein the rotation restricting piece is formed in a U-shaped cross section that opens downward.