JP2002371585A - Swing device and hydraulic circuit of clamshell bucket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a swing device and a hydraulic circuit of a clamshell bucket capable of horizontally swinging a bucket suspended from the tip of an expansible boom. SOLUTION: This clamshell bucket capable of grasping sediment by a pair of laterally rotating buckets 43 and 44 comprises a swinging mechanism 35 having a suspended upper part and a lower part rotatable in circumferential direction, a mast 36 connected to the lower part of the swinging mechanism 35, the pair of buckets 43 and 44 pivotally supported on the lower part of the mast 36 so as to be rotated in lateral direction, and a pair of hydraulic cylinders installed between the upper part of the mast 36 and the buckets 43 and 44 to rotate the buckets 43 and 44. The swinging mechanism 35 comprises a suspended cylindrical fixed body 68 positioned at the upper part thereof and a cylindrical driven body 69 positioned at the lower part thereof and forming an opening. The fixed body 68 is inserted into the opening of the driven body 69 to fix it so as to be rotated in circumferential direction. A hydraulic motor 102 for rotating the fixed body 68 and the driven body 69 each other is installed between the fixed body and the driven body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to, for example, civil engineering,
For construction work, etc., a clamshell bucket used for drilling a hole whose depth is extremely deep compared to its diameter, and in particular, a clamshell bucket in which a bucket suspended at the end of a telescopic boom can be turned horizontally. The present invention relates to a swing device and a hydraulic circuit.

[0002]

2. Description of the Related Art Conventionally, in civil engineering work, construction work, and the like, there has been a work process of digging a deep hole with a depth that is smaller than a diameter. For example, holes for anchors for supporting towers, holes for burying septic tanks, foundation work for buildings, well excavation work and the like can be mentioned. In such a deep digging operation, an extremely deep hole having a depth of 15 to 20 meters has to be digged while the diameter of the hole is about 5 meters.

In such a deep digging operation, a telescopic boom is generally used in which a plurality of telescopic booms are assembled in a telescopic manner, and this telescopic boom is attached to the arm of an excavator, and a crumb is attached to the tip of the lowermost boom. Deep excavators with shell buckets suspended were used. Most of the structure of this deep excavator is constituted by an extendable arm attached to the end of the boom, and this arm extends the clamshell bucket deeply by two or more stages of telescopically combined arms. It was characterized by a structure that hung it to the bottom of the hole.

In a conventional deep excavator, an arm for supporting a telescopic boom is pivotally supported above a vehicle body so as to be able to swing up and down and to turn on a horizontal plane. However, the clamshell bucket was suspended so that it could not pivot on the horizontal plane with respect to the tip of the telescopic boom. That is, the distal end of the telescopic boom and the clamshell bucket are connected via the universal joint, and the clamshell bucket can hang down by its own weight. However, it is possible to swing freely with a pair of intersecting axes, but it is not possible to perform a horizontal swing motion.
In the case of a clamshell bucket, a pair of shell buckets always open and close in a fixed direction, so that the shape of the hole to be dug has been somewhat square. This is because the hole to be dug had to be square because of the mechanism for grasping the earth and sand with the right and left clamshell buckets.

[0005] However, the shape of the hole to be dug differs depending on the purpose of the hole. For example, there are many holes such as a hole for anchoring a steel tower, a hole for embedding a septic tank, a hole for foundation work of a building and a well excavation work. In many cases, the hole is very circular. When digging such a circular hole, the shape of the hole digged by the conventional clamshell bucket is only a little square, so the excavation position by the clamshell bucket is sequentially shifted sideways and a shape close to a circle. Is excavated, but a rectangular non-excavated portion remains at the periphery of the hole. For this reason, in the related art, it has been necessary for a worker who has fallen into the hole to manually excavate the earth and sand at the corner of the hole left in the square shape to form a round shape. For this reason, conventionally, when it is necessary to dig a circular hole, it takes a great deal of labor and the work becomes complicated, and the efficiency is reduced accordingly, but it is not always possible to dig a good circular hole. There was a problem.

Therefore, in order to dig a circular hole,
A mechanism has been proposed in which a clamshell bucket suspended at the tip of a telescopic boom can be turned horizontally. For example, Japanese Patent Application No. 325032 discloses a mechanism in which two hydraulic circuits are arranged in the direction of a clamshell bucket from the driver's seat side of an excavator. In this mechanism,
The opening and closing movement of the clamshell bucket can be operated by one hydraulic circuit, and the operation of turning the clamshell bucket in the horizontal direction can be performed by the other hydraulic circuit. This is because, in this configuration, the clamshell bucket can be turned in any horizontal direction, and the position of the bottom of the hole with which the clamshell bucket claw contacts can be changed. In this device, once the bottom of the hole is dug by the clamshell bucket, the clamshell bucket can be turned to slightly shift the angle to perform the next excavation work. By sequentially performing this operation, the position of the bottom of the hole with which the clamshell bucket comes into contact is gradually changed, and circular earth and sand can be dug.

However, in this configuration, a hydraulic motor is interposed between the telescopic boom and the clamshell bucket, and the rotational force of the hydraulic motor causes the clamshell bucket to pivot horizontally. Therefore, between the excavator body side and the clamshell bucket,
It was necessary to arrange two hydraulic circuits, a hydraulic cylinder for opening and closing the clamshell bucket and a hydraulic motor for rotating the clamshell bucket. If two hydraulic circuits are arranged on the telescopic boom, four hydraulic hoses must be provided inside the telescopic boom, which complicates the structure and forms a long hydraulic path. Maintenance and inspection were difficult.

[0008]

SUMMARY OF THE INVENTION In view of such circumstances, the present invention provides a hydraulic motor provided between a clamshell bucket and a telescopic boom and a hydraulic oil supplied to a hydraulic cylinder for opening and closing the clamshell bucket. An object of the present invention is to provide a turning device and a hydraulic circuit for a clamshell bucket in which a flow path is shared by a single hydraulic circuit. In this configuration, the hydraulic motor for rotating the clamshell bucket and the pressure oil for operating the hydraulic cylinder for opening and closing the clamshell bucket can be shared by a single hydraulic circuit. One of the hydraulic circuits required for the system can be omitted.

[0009]

The invention according to claim 1 of the present application is used by being suspended vertically, having a pair of buckets rotating left and right at the lower part thereof, and sediment can be grasped by the buckets. In a clamshell bucket,
A turning drive mechanism in which the upper and lower parts can rotate in the circumferential direction and the upper part is suspended, a mast connected to the lower part of the turning drive mechanism, and a pair of rotatably supported left and right sides of the lower part of the mast, respectively. A bucket, a pair of hydraulic cylinders interposed between the upper part of the mast and the respective buckets and rotating the bucket, the turning drive mechanism is a columnar fixed body located at the upper part and suspended, It is composed of a cylindrical follower with an opening formed at the lower part, and is connected so that it can rotate in the circumferential direction by inserting the fixed body into the opening of the follower, and between the fixed body and the follower. An object of the present invention is to provide a revolving device for a clamshell bucket, in which a hydraulic motor for rotating the both is interposed.

According to a second aspect of the present invention, there is provided a clamshell bucket which is used by being suspended vertically and has a pair of buckets which are rotatable left and right at a lower portion thereof, and which can grab earth and sand by the bucket. A turning drive mechanism in which the lower part and the lower part can rotate in the circumferential direction and the upper part is suspended,
A mast connected to the lower portion of the turning drive mechanism, a pair of buckets rotatably supported on the left and right of the lower portion of the mast, and a bucket interposed between the upper portion of the mast and each bucket to rotate the bucket. The turning drive mechanism is composed of a pair of hydraulic cylinders, and the turning drive mechanism is composed of a cylindrical fixed body that is suspended at the upper part and a cylindrical driven body that is located at the lower part and has an opening. The body is inserted so that it can rotate in the circumferential direction by being inserted into the opening of the driven body, and a hydraulic motor for rotating the two parts mutually is interposed between the fixed body and the driven body. A swivel groove is formed, and each swivel groove communicates with the lower end of an independent cylinder oil passage extending inside the fixed body and extending to the top, and the inner periphery of the driven body is independent of the swivel groove. Communicate Forming a communicating oil passage, each communicating oil passage is to provide a turning device of the clamshell bucket, characterized in that connecting the supply outlet port of the hydraulic cylinder.

According to a third aspect of the present invention, there is provided a clamshell bucket which is used by being suspended vertically and has a pair of buckets which are rotatable left and right at a lower portion thereof and which can seize earth and sand by the bucket. A turning drive mechanism in which the lower part and the lower part can rotate in the circumferential direction and the upper part is suspended,
A mast connected to the lower portion of the turning drive mechanism, a pair of buckets rotatably supported on the left and right of the lower portion of the mast, and a bucket interposed between the upper portion of the mast and each bucket to rotate the bucket. The turning drive mechanism is composed of a pair of hydraulic cylinders, and the turning drive mechanism is composed of a cylindrical fixed body that is suspended at the upper part and a cylindrical driven body that is located at the lower part and has an opening. The body is inserted so that it can rotate in the circumferential direction by being inserted into the opening of the driven body, and a hydraulic motor for rotating the two parts mutually is interposed between the fixed body and the driven body. A pair of cylinder oil passages and a pair of motor oil passages are formed in the vertical direction inside the fixed body, and the lower ends of the cylinder oil passages are connected to the respective swivel grooves. -The lower end of the oil passage communicates with the hydraulic motor, and on the inner periphery of the driven body, there are formed communication oil passages that communicate independently with the swivel grooves, and each communication oil passage is connected to the supply / discharge port of the hydraulic cylinder. , One motor oil passage is connected to a cylinder oil passage on the side that opens the bucket via a pressure control valve that opens when the pressure becomes equal to or higher than a predetermined pressure, and this cylinder oil passage is connected to a pressure oil supply / discharge mechanism, The other motor oil passage is connected to the cylinder oil passage on the side that closes the bucket via a check valve that allows the flow of pressure oil in one direction, and this cylinder oil passage is connected to a pressure oil supply / discharge mechanism. And a hydraulic circuit for the clamshell bucket.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In this embodiment, an example in which the present invention is applied to a deep excavator that digs a deep hole vertically from the ground to the ground for use in foundation work and burial work of a structure will be described.

FIG. 1 is a perspective view of a deep excavator showing a state in which a clamshell bucket is suspended from a telescopic boom. Crawlers 11 and 11 are wound around the left and right sides of the body 10 of the deep excavator, respectively.
The vehicle body 10 can be freely moved forward, backward, left and right by the use of the wheels 1 and 11. A work table 12 provided with an operator's seat is mounted on the upper part of the vehicle body 10, and the work table 12 can be turned in a range of 360 degrees in a horizontal direction with respect to the vehicle body 10. On the upper front surface of the worktable 12, the lower end of an arm 13 bent in a slightly "U" shape is pivotally supported so as to be able to swing up and down. Hydraulic cylinders 14, 14 for elevation control are interposed between both sides of the center of the arm 13 and the front surface of the work table 12. An elongated outer boom 15 having a hollow rectangular cross section is connected to the tip of the arm 13 by a connecting piece 16 and a support pin 17 so as to be vertically swingable. A hydraulic cylinder 18 is interposed between the center of the back surface of the arm 13 and the connecting piece 16.

The outer boom 15 has a hollow elongated shape formed by bending a thin steel plate to have a rectangular cross section, and a hollow middle boom 19 is slidably inserted into the lower end opening. . The middle boom 19 has a hollow elongated shape formed by bending a thin steel plate into a rectangular cross section, and an inner boom 20 having a hollow inside is slidably inserted into the lower end opening. The inner boom 20 has an elongated shape with a hollow inside formed by bending a thin steel plate to have a rectangular cross section. The outer boom 15, the middle boom 19, and the inner boom 2
The telescopic boom 21 is assembled in a telescopic shape that can be extended and retracted in three stages by 0.

At the end of the inner boom 20, a bracket 2 is provided.
5, a universal joint 26 is connected to the front surface of the bracket 25, and a bucket 27 is connected to the universal joint 26. This universal joint 26
Are arranged and connected so that a pair of pins intersect at the top and bottom, and the direction in which each pin rotates is a two-dimensional direction. Therefore, the angle of the bucket 27 with respect to the inner boom 20 can be freely changed in the left, right, front and rear directions, and the bucket 27 is hung so as to be always vertical by the two degrees of freedom of the universal joint 26. Has been lowered. The structure of this suspension is generally used conventionally.

FIG. 2 is a perspective view showing the entirety of the bucket section 27 described above. The universal joint 26 is connected to the upper part of the bucket part 27, the upper pin 31 is inserted in the upper part of the universal joint 26 in the horizontal direction, and the lower pin 32 is horizontally inserted in the lower part of the universal joint 26. It is inserted in the direction. Upper pin 31
The lower pin 32 and the lower pin 32 are disposed so as to be perpendicular to each other, and the lower pin 32 is connected to an upper part of a turning drive mechanism 35 provided in the bucket 27. The universal joint 26
Is a well-known structure and will not be described here. A mast 36 is vertically connected to a lower portion of the turning drive mechanism 35, and the mast 36 is connected to the turning drive mechanism 35.
Are combined so as to be rotatable in the horizontal direction. At the lower end of the mast 36, a rectangular support plate 37 cut from a thin steel plate is fixed so as to be horizontal. Parallel brackets 38 and 39 are fixedly attached to the lower surface of the support plate 37 on the left and right with a space therebetween, and the pair of parallel brackets 38 and 39 are arranged so as to be parallel. The mast 36, the support plate 37, and the parallel brackets 38 and 39 form a skeleton of the bucket portion 27.

A pair of bracket shafts 41 and 42 are rotatably supported on the left and right lower portions of the parallel brackets 38 and 39, and the two parallel brackets 38 and 39 are arranged so as to be parallel at an interval. It is. Next, bucket 4
3, 44 are for digging earth and sand,
Each of the side plates 3 and 44 has a fan shape, and a bottom plate is provided between the arc-shaped sides of the both plates, and a claw is projected from the bottom plate. The shape of the buckets 43, 44 is conventionally known. Both ends of the bracket shaft 41 are fixed to the fan-shaped essential positions of both side plates of the bucket 43, and both ends of the bracket shaft 42 are fixed to the fan-shaped essential positions of the both side plates of the bucket 44. With this configuration, the bucket 43 can rotate together with the bracket shaft 41, and the bucket 44 can rotate together with the bracket shaft 42.
By this operation, the lower portions of the buckets 43 and 44 can be opened and closed, and at this time, the respective claws can be engaged and separated. And
An opening / closing arm 45 is fixed to the center of the bracket shaft 41 located between the parallel brackets 38 and 39, and the opening / closing arm 45 is disposed so as to protrude rearward (to the far left in FIG. 2). An opening / closing arm 46 is provided at the center of the bracket shaft 42 located between the parallel brackets 38 and 39.
The opening / closing arm 46 is disposed so as to protrude forward (to the front right in FIG. 2). With this configuration, the opening / closing arm 45 is arranged to extend to the internal space of the bucket 43, and the opening / closing arm 46 is arranged to extend to the internal space of the bucket 44. The bracket shaft 41, the bucket 43, and the opening / closing arm 45 rotate integrally with the parallel brackets 38, 39, and the bracket shaft 42, the bucket 44, and the opening / closing arm 46 integrally with the parallel brackets 38, 39. Can rotate.

Next, cylinder support plates 49 and 50 are fixed to the left and right side surfaces of the upper portion of the mast 36, respectively, and each of the cylinder support plates 49 and 50 has a pair of flat plates arranged in parallel. The upper end of the hydraulic cylinder 51 is rotatably connected between the cylinder support plates 49 by pins 53, and the upper end of the hydraulic cylinder 52 is rotatably connected between the cylinder support plates 50 by pins 54. It is. A cylinder rod 57 can extend and contract from the lower end opening of the hydraulic cylinder 51, and the tip of the opening / closing arm 45 is connected to the lower end of the cylinder rod 57 by a pin 59. Similarly, a cylinder rod 58 can extend and contract from the lower end opening of the hydraulic cylinder 52, and the tip of the opening / closing arm 46 is connected to the lower end of the cylinder rod 58 by a pin 60.

FIG. 3 is an enlarged view of the vicinity of the upper portion of the bucket 27 in FIG. 3, the universal joint 26 in FIG. 2 is omitted. FIG. 4 shows a state in which the turning drive mechanism 35 is pulled upward from the mast 36. The configuration near the upper portion of the mast 36 and the external shape of the turning drive mechanism 35 will be described with reference to FIGS.

At the top of the mast 36, a flange 61 whose plane is expanded horizontally is fixed, and the inside diameter of this flange 61 is the same as the inside diameter of the mast 36. By connecting the flange 61 to the mast 36, the upper portion of the mast 36 has a shape which is flattened outward. A plurality of openings 62 are formed vertically around the flange 61, and the openings 62 are arranged at equal intervals in the circumferential direction.
In the present embodiment, six locations are opened around the flange 61. The left and right side surfaces of the upper part of the mast 36 are opened through rectangular window holes 63 and 64.
Reference numerals 3 and 64 are formed at positions perpendicular to the cylinder support plates 49 and 50.

FIG. 4 shows the external appearance of the turning drive mechanism 35, but the entire turning drive mechanism 35 is inserted into the mast 36 from the upper end opening thereof and assembled. The configuration of the turning drive mechanism 35 is largely divided into an upper fixed body 68 and a lower driven body 69, and the fixed body 68 and the driven body 69 are configured to be relatively rotatable (this rotatable configuration). Will be described later in detail). The upper surface of the fixed body 68 has a flat disk shape, and a pair of hanging pieces 70 and 71 are vertically fixed at an interval on the upper surface. The hanging pieces 70 and 71 are for connecting to the universal joint 26 described above. In addition, the follower 69
A mounting ring portion 72 that is enlarged in the horizontal direction is formed at the upper portion, and a plurality of openings 73 are formed around the mounting ring portion 72 in the vertical direction. They are arranged at equal intervals, and in this embodiment, six locations are opened around the mounting ring 72. This follower 6
9 has a cylindrical shape, and the entire driven body 69 can be inserted from the upper end opening of the mast 36.

In order to connect the fixed body 68 and the driven body 69, a bolt 74 is inserted into the openings 62 and 73, and a nut 75 is screwed from the lower end of the bolt 74, so that both can be fixed. The left and right sides of the upper side surface of the driven body 69 are cut flat to form flat port surfaces 77 and 78 (the port surface 78 is not shown in FIG. 4 because it is the back side). Therefore, when the follower 69 is inserted into the mast 36, the port surface 77 matches the position of the window hole 63, and the port surface 78 matches the position of the window hole 64. In this state, the block-like manifold 79 is inserted through the window hole 63, and the manifold 79 is screwed and fixed to the port surface 77. Similarly, a block-shaped manifold 80 is inserted through the window hole 64 and the port surface 78 is inserted.
The manifold 80 is fixed with screws. Each of the manifolds 79 and 80 has an L-shaped block shape having an oil passage formed therein, and has a bent portion positioned upward and fixed downward so as to hang down.

Next, FIG. 5 is an exploded view showing members constituting the turning drive mechanism 35 shown in FIG. As described above, the turning drive mechanism 35 is roughly divided into two members, that is, a driven member 69 and a fixed member 68.
A follower 69 is rotatably inserted through the upper opening. The main part of the follower 69 is a cylindrical body 8
At 3, the upper part of the trunk body 83 is connected to a mounting ring portion 72 which is expanded horizontally toward the outside, and both are integrally formed in a table shape with a flat upper surface. An insertion hole 84 that penetrates up and down is formed at the center of the body 83 from the center of the upper surface of the mounting ring 72. Also,
The main part of the fixed body 68 is a shaft body 87 having a slightly thick outer diameter.
A disk-shaped port portion 88 is mounted on the top of the shaft body 87, and a thin disk-shaped table 89 is mounted on the upper surface of the port portion 88. And the shaft body 87
The lower end of the rotor male part 90 is connected to a cylindrical rotor male part 90, and the lower end of the rotor male part 90 is connected and extended with a small-diameter suspension part 91. Has a threaded portion 92 formed by cutting. These shaft bodies 8
7, port section 88, table 89, rotor male section 90,
The hanging portion 91 and the screw portion 92 are integrally formed by cutting one material.

As shown in FIG. 5, a port 9 for connection to a joint of a hydraulic hose is provided around the port 88.
5, 96, 97, 98 are installed so as to protrude,
Each port 95, 96, 97, 98 is a shaft body 87
It communicates with the oil passage drilled inside. In FIG. 5, the ring-shaped rotor female portion 101 has a ring shape. The rotor female portion 101 is fitted to the rotor male portion 90 described above. The inner diameter of the rotor female portion 101 is substantially the same as the outer diameter of the rotor male portion 90, and an impeller is formed on the inner peripheral surface of the rotor female portion 101 and the outer peripheral surface of the rotor male portion 90, respectively. When the part 101 is inserted into the rotor male part 90, the respective impellers are arranged so as to face each other. A hydraulic motor 102 is formed by the combination of the rotor male part 90 and the rotor female part 101, and the rotor female part 10 is supplied by supplying pressure oil.
1 is driven with respect to the rotor male part 90. A key groove 103 is cut on the outer periphery of the rotor female portion 101 in the axial direction, and a key 104 having a plate shape can be fitted into the key groove 103.

Next, the spacer 107 is inserted from the lower end of the hanging portion 91, and the inner diameter thereof is
And has an outer diameter that is the same as the inner diameter of the insertion hole 84. The spacer 107 is pushed up from below so that the rotor female part 101 does not move up and down. The holding cup 108 has a cylindrical shape whose outer diameter is substantially the same as the outer diameter of the body 83, and has a recess 112 at the center of the upper surface thereof, and further has an opening 113 at the center of the recess 112. It is penetrated.
The inner diameter of the concave portion 112 of the holding cup 108 is the spacer 1
07 is set almost the same as the outer diameter. The washer 109 is in close contact with the lower surface of the holding cup 108, and the nut 110 that is disposed on the lower surface of the washer 109 is a nut 110 that connects the fixed body 68 and the driven body 69 so as not to come off. The female screw formed on the inner peripheral surface of the nut 110 matches the pitch of the screw portion 92.

In order to assemble the plurality of members shown in FIG. 5, the rotor female portion 101 is inserted into the rotor male portion 90, and the rotor female portion 101 is wrapped around the rotor male portion 90.
Are fitted so that they can rotate freely. At this time, the key 104 is engaged with the key groove 103 formed on the inner wall surface of the key groove 103 and the insertion hole 84, and the rotor female portion 101 is engaged.
And the body 83 are connected so as not to rotate in the circumferential direction. Then, the spacer 107 is inserted into the hanging portion 91, and in this state, the shaft main body 87 is inserted from the upper opening of the insertion hole 84. Then, the suspending portion 9 is pulled from the lower surface of the trunk main body 83.
1 and the screw portion 92 are exposed, and the opening 113 of the holding cup 108 is inserted into the exposed hanging portion 91. Thereafter, the washer 109 is inserted into the hanging portion 91, and the nut 110 is screwed into the screw portion 92. Then
The spacer 107 is fitted in the recess 112, and the fixed body 68 and the driven body 69 are assembled. FIG. 6 is a sectional view of the assembled state.
Indicated by

FIG. 6 is a sectional view taken along the line AA in the state of FIG. 3 in which the turning drive mechanism 35 in FIG. 5 is assembled and the turning drive mechanism 35 is fitted to the mast 36. FIG. 6 illustrates a connection state with an oil passage formed inside the port portion 88 and the main body shaft portion 87.

Inside the port portion 88 and the main body shaft portion 87, cylinder oil passages 115, 118,
The motor oil passages 116 and 117 are bored independently. The upper ends of the cylinder oil passages 115 and 118 and the motor oil passages 116 and 117 communicate with ports 95, 96, 97 and 98 formed on the side surface of the port portion 88, respectively. That is, the upper end of the cylinder oil passage 115 is connected to the port 9
5, the upper end of the motor oil passage 116 communicates with the port 96, the upper end of the motor oil passage 117 communicates with the port 97, and the upper end of the cylinder oil passage 118 communicates with the port 98 independently. Swivel grooves 119 and 120 are formed on the outer periphery of the main body shaft portion 87 so as to make a circuit around the peripheral surface, and the lower end of the cylinder oil passage 115 is connected to the swivel groove 1.
19, the lower end of the cylinder oil passage 118 has a swivel groove 12
0 is connected to each. Also, the motor oil passage 116
The lower ends of the and 117 are opened at positions opposite to the left and right in the rotor male part 90.

In FIGS. 4 and 5 described above, a flat port surface 77 is formed on the side surface of the follower 69, but a communication oil passage 121 penetrates through the center of the port surface 77 as shown in FIG. The opening inside the communication oil passage 121 is opposed to the swivel groove 119. Similarly, although not shown in FIGS. 4 and 5, a flat port surface 78 is formed on the side surface on the opposite side of the driven body 69, but as shown in FIG. The communication oil passage 122 penetrates, and the opening inside the communication oil passage 122 is
0. Further, an L-shaped block-shaped manifold 79 is in close contact with the port surface 77, and an L-shaped oil passage 12 is provided inside the manifold 79.
3 is bored, and the upper end opening of the oil passage 123 is
1 and an opening at the lower end of the oil passage 123 is formed with a port 125 for connecting a hydraulic hose. Similarly, an L-shaped block-shaped manifold 80 is in close contact with the port surface 78, and an L-shaped oil passage 124 is bored inside the manifold 80.
The upper end opening of the oil passage 12 is connected to the communication oil passage 122,
4 has a port 12 for connecting a hydraulic hose.
6 are formed.

Next, FIG. 7 schematically shows a configuration of a hydraulic circuit according to an embodiment of the present invention. As described above, the cylinder oil passage 115,
The motor oil passages 116 and 117 are bored in the vertical direction. The lower ends of the motor oil passages 116 and 117 serve as pressure oil supply passages to the hydraulic motor 102 composed of the rotor male part 90 and the rotor female part 101. Connected. One end of a hydraulic hose 141 is connected to a port 125 formed in the manifold 79, and the space on the extension side of the hydraulic cylinders 51 and 52 is connected to the other end of the hydraulic hose 141. Also, the port 12 formed in the manifold 80
One end of a hydraulic hose 142 is connected to 6, and the other end of the hydraulic hose 142 is connected to a space on the reduction side of the hydraulic cylinders 51 and 52. When pressure oil is supplied from the hydraulic hose 141 by this piping, the hydraulic cylinder 51,
Pressure oil is injected into the space on the extension side of 52, and the cylinder rods 57 and 58 are respectively extruded. When pressure oil is supplied to the hydraulic hose 142, the hydraulic cylinder 5
Pressure oil is injected into the space on the reduction side of the hydraulic cylinders 1 and 52, and the cylinder rods 57 and 58
Drawn inside.

The aforementioned port 96 has a check valve 132
Is connected to the port 95 and the check valve 132.
Is connected to one end of the cut-off valve 134. The check valve 132 does not prevent the flow of the pressure oil from the port 96 to the switching valve 134, but prevents the flow in the reverse direction. Further, one end of a pressure control valve 131 is connected to the port 97, and the other end of the pressure control valve 131 and the port 98 are connected to the other end of the switching valve 134. Pressure control valve 131
The oil passage is closed at a normal pressure value, but is self-opened when the pressure value becomes equal to or higher than a set pressure value, so that the port 97 and the cut-off valve 134 are communicated. Further, the cut-off valve 134
Is connected to a discharge side of a hydraulic pump 135, a suction side of the hydraulic pump 135 is connected to an oil tank 136, and an oil tank 136 is connected to a discharge side of the cut-off valve 134.
Is connected.

Next, the operation of the embodiment of the present invention will be described.

The excavation operation of earth and sand is performed in the state shown in FIG. 1 in which the bucket 27 is suspended on the telescopic boom 21 of the excavator. In this operation, the excavator operates by operating a hydraulic pressure generating device (not shown) housed inside the vehicle body 10 to generate pressure oil and supplying the pressure oil to each part of the excavator. In the operation of moving the excavator, the crawler 11 is driven by a hydraulic motor operated by pressure oil, and the entire excavator can be freely moved in the front, rear, left, and right directions.
Further, by supplying the pressure oil to the hydraulic cylinders 14 and 15, the arm 13 and the telescopic boom 21 can be swung up and down. By supplying pressure oil to a hydraulic cylinder (not shown) housed inside the telescopic boom 21, the middle boom 19 and the inner boom 20 can be expanded and contracted from the outer boom 15. By a combination of these operations, the bucket portion 27 can be moved to a position to be excavated, and the bucket portion 27 can be hung in a deep hole to excavate earth and sand.

In the operation of excavating earth and sand by the bucket portion 27, the left and right buckets 43 in the bucket portion 27 are moved.
And 44 are opened and closed by hydraulic cylinders 51 and 52. That is, the switching valve 134 is switched to the positive side to supply the pressure oil in the oil tank 136 sucked by the hydraulic pump 135 to the port 98. At this time, since the pressure value of the pressure oil is not high, the pressure control valve 131 is closed and is not supplied to the port 97. The pressure oil flowing into the port 98 passes through the cylinder oil passage 118, the swivel groove 120, the communication oil passage 122, and the oil passage 124, and is discharged from the port 126. Next, pressure oil is injected into the space on the reduced side of both hydraulic cylinders 51 and 52 via the hydraulic hose 142,
Cylinder rods 57 and 58 are hydraulic cylinders 51 and 5
2 is drawn inside. As shown in FIG. 2, the interval between the hydraulic cylinder 51 and the cylinder rod 57 is reduced, and the opening / closing arm 45 is raised to move the bucket shaft 41.
Is rotated rightward in the drawing, and the bucket 43 is also rotated in the same direction. Similarly, the interval between the hydraulic cylinder 52 and the cylinder rod 58 is reduced, the opening / closing arm 46 is pulled up, the bucket shaft 42 is rotated leftward in the drawing, and the bucket 44 is also rotated in the same direction. Thus, the left and right buckets 43 and 44 rotate rightward and leftward, respectively, so that both ends of the buckets 43 and 44 are separated from each other and open greatly downward. If the bucket is dropped to the bottom of the hole in this state, the claws of the buckets 43 and 44 are inserted into the bottom.

Next, in order to grasp the earth and sand at the bottom of the hole, the switching valve 134 is switched to the opposite side, and the pressure oil in the oil tank 136 sucked by the hydraulic pump 135 is supplied to the port 95. At this time, pressure oil does not flow into the port 96 because the check valve 132 is in the opposite direction. The pressure oil flowing into the port 95 is supplied to the cylinder oil passage 115, the swivel groove 119,
The oil passes through the communication oil passage 121 and the oil passage 123 and is discharged from the port 125. Next, pressure oil is injected into the space on the extension side of the two hydraulic cylinders 51 and 52 via the hydraulic hose 141, and the cylinder rods 57 and 58 are
Extruded from 1, 52. When the distance between the hydraulic cylinder 51 and the cylinder rod 57 becomes longer, the opening / closing arm 45 is pushed down as shown in FIG. 2, the bucket shaft 41 is rotated leftward in the figure, and the bucket 43 is also rotated in the same direction. Similarly, when the interval between the hydraulic cylinder 52 and the cylinder rod 58 increases, the opening / closing arm 46 is pushed down, the bucket shaft 43 is rotated rightward in the drawing, and the bucket 44 is also rotated in the same direction. In this manner, both ends of the left and right buckets 43 and 44 rotate so as to approach each other, and the claws of the buckets 43 and 44 grasp the earth and sand.
Take in the internal space of 4. Then, when the total length of the telescopic boom 21 is reduced, the bucket 27
The whole can be lifted from the hole to the ground. By repeating this operation, it becomes possible to excavate earth and sand from the bottom of the hole to be excavated. This operation is the same as the operation of a conventionally known deep excavator.

As described above, in the operation of excavating earth and sand from the bottom of a deep hole, if the direction of the buckets 43 and 44 is always constant, the position of contact with the bottom of the hole will always be the same, and the buckets 43 and 44 will always be in the same position. It becomes a square hole due to the shape of. In order to excavate as a circular hole, it is necessary to deflect the directions of the buckets 43 and 44 in the excavation operation. To change the horizontal position of the buckets 43, 44, the operator at the work table 12 can remotely operate the buckets 43, 44, and this change operation is performed in conjunction with the operation of opening the buckets 43, 44. Can be.

As described above, in order for the operator to open the buckets 43 and 44 from the closed state, the cut valve 1 is required.
34 is switched to the positive side, and the pressure oil from the hydraulic pump 135 is output to the pressure control valve 131. If the pressure of the pressure oil applied to the pressure control valve 131 is a normal pressure value, the pressure control valve 1
Numeral 31 is closed, and the pressure oil is not supplied to the port 97 but supplied only to the port 98 (when the pressure is lower than the operating value set in the pressure control valve 131). Therefore, the pressure oil flows in a direction to reduce the hydraulic cylinders 51 and 52 via the hydraulic hose 142 as described above. Then, when the cylinder rods 57, 58 are housed inside the hydraulic cylinders 51, 52 and move to a position where they cannot be further reduced, and the cut-off valve 134 is still held on the positive side, the cylinder rod 57, 58 is supplied from the hydraulic pump 135. Pressure oil pressure increases. Then, the pressure control valve 131 is opened because the pressure value becomes higher than the preset pressure value, and the pressure oil flows into the port 97 through the pressure control valve 131 (the pressure oil is set to the pressure control valve 131). When a pressure higher than the operating value is applied).

The pressure oil flowing from the port 97 flows through the motor oil passage 117 to the rotor male part 90 and the rotor female part 1.
01, the rotor female part 101 is rotated around the rotor male part 90 by the action of the impellers provided on both sides. The inflowing pressure oil is collected from the opposite side of the rotor male part 90 and the rotor female part 101 and discharged from the port 96 through the motor oil passage 116.
The discharged pressure oil passes through the check valve 132 in the forward direction, and is collected in the oil tank 136 by the cut-off valve 134.

As described above, when the pressure control valve 131 is opened by the rise of the pressure oil, the pressure oil is released from the hydraulic motor 1.
02, whereby the rotor female part 101 is rotated in the circumferential direction with respect to the rotor male part 90. When the rotor female portion 101 is driven, its rotational force is transmitted to the trunk main body 83 by the key 104, and the trunk main body 83 is rotated around the shaft main body 87. That is, the driven body 69 and the fixed body 68 are mutually rotated in the circumferential direction.
8 is connected and fixed to the inner boom 20 by the universal joint 26, so that only the follower 69 is swung in the horizontal direction. Since the flange 61 of the mast 36 is connected to the mounting ring 72 of the driven body 69,
As the 3 rotates, the entire suspended mast 36 is also swung in the same direction. Then, the bucket 4 in which the cylinder supporting plates 49 and 50 are also swung and suspended.
3 and 44 are turned to change the directions of the buckets 43 and 44. When the buckets 43 and 44 are swung horizontally and turned to a target position, the turning operation must be stopped at that position. Stop of turning is the cut-off valve 13
Perform by returning 4 to neutral. When the supply of the pressure oil from the cut-off valve 134 is stopped, the pressure control valve 131 closes to stop the flow of the pressure oil.
2 stops the operation. When the operation of the hydraulic motor 102 is stopped, the buckets 43 and 44 are kept stopped at that position.

By rotating the buckets 43 and 44 in the circumferential direction as described above and repeating this operation, the bucket 4
The positions of the buckets 43 and 44 can be changed by changing the directions of the buckets 3 and 44. By repeating this operation, the positions of the bottoms of the holes that the buckets 43 and 44 grasp can be changed, and the bottoms of the deep holes can be dug in a circular shape.

[0041]

According to the present invention, the clamshell bucket suspended by the telescopic arm or the like can be held so as to be pivotable in the horizontal direction, and the pair of buckets is pivoted while suspended. Can be done. In the case of digging a deep hole using the clamshell bucket, the bucket does not face only in a certain direction, but can be turned in the circumferential direction to excavate earth and sand uniformly. For this reason, the bottom of the hole is not dug out in a square shape, but can be dug out in a circular shape, and the efficiency of the excavating operation is increased. Since the hydraulic motor of the drive source for turning the bucket is housed inside the mast, the volume is not increased and the bucket can be reduced.

In the invention of the present application, the turning drive mechanism for suspending the entire clamshell bucket is composed of a fixed body and a driven body, and both are rotatable with each other. It can be fixed to the follower and turned. A plurality of oil passages are bored inside the fixed body, and one pair of oil passages communicates with the hydraulic motor, while the other pair of oil passages communicates with a swivel groove formed around the fixed body. It is. A communication oil passage connected to a hydraulic cylinder for opening and closing the bucket is formed in the driven body, and the swivel groove and the communication oil passage are opposed to each other. With this configuration, even if the fixed body and the driven body turn relative to each other, the pressure oil can be reliably supplied to and discharged from the hydraulic cylinder. The hydraulic motor interposed between the fixed body and the driven body can be similarly supplied and discharged through the oil passage.

The oil passage communicating with the hydraulic motor among the oil passages formed in the fixed body is connected to a pressure oil supply via a pressure regulating valve and a check valve, and is connected in parallel to the pressure oil supply. An oil passage communicating with the hydraulic cylinder is connected. For this reason, pressure oil is not supplied to the hydraulic motor at normal pressure, but if the internal pressure increases with the bucket fully open, the pressure regulating valve opens and pressure oil is supplied to the hydraulic motor, causing the clamshell bucket to open. Can be turned.
For this reason, even if the distance to the clamshell bucket is long, the hydraulic path for supplying and discharging the pressure oil to the hydraulic cylinder and hydraulic motor can be shared by two hydraulic hoses of one system, etc. Can be omitted.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a state in which a clamshell bucket according to an embodiment of the present invention is suspended from a deep excavator.

FIG. 2 is a perspective view showing the entire configuration of the clamshell bucket of the present invention.

FIG. 3 is an enlarged perspective view showing the vicinity of a drive turning mechanism in an upper portion of the clamshell bucket according to the present invention.

FIG. 4 is an exploded perspective view showing a member of the clamshell bucket according to the present invention, in which a drive turning mechanism at an upper portion is removed from a mast.

FIG. 5 is an exploded perspective view showing members constituting a drive turning mechanism in an upper part of the clamshell bucket of the present invention, which are vertically separated.

FIG. 6 is a view showing a state in which a drive swing mechanism at an upper portion of a clamshell bucket according to the present invention is cut vertically,
FIG. 3 is a cross-sectional view as viewed in the direction of arrow A.

FIG. 7 is a hydraulic circuit showing a configuration for opening and closing and simultaneously turning a clamshell bucket according to the present invention. 27 Bucket part 35 Rotation drive mechanism 36 Mast 43 Bucket 44 Bucket 51 Hydraulic cylinder 52 Hydraulic cylinder 68 Fixed body 69 Follower 102 Hydraulic motor 115 Cylinder oil passage 116 Motor oil passage 117 Motor oil passage 118 Cylinder oil passage 119 Swivel groove 120 Swivel groove 112 Connection oil passage 113 Connection oil passage 131 Pressure control valve 132 Check valve

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F16L 39/04 F16L 39/04 F-term (Reference) 2D003 AA01 AB02 AB04 BB03 CA02 DA02 3F004 EA36 NA08 PA06 PB06 PC30 3J106 AA01 AB01 BA02 BB01 BC04 BC09 BD01 BE29 CA06 EA03 EC02 EC07 ED50 EE01 EF05

Claims (3)

[Claims] 1. A clamshell bucket which is used by being suspended vertically and has a pair of buckets which are rotatable left and right at a lower part thereof, and wherein the bucket is capable of gripping earth and sand, wherein an upper part and a lower part are circumferentially arranged. A swivel drive mechanism that can be rotated and the upper part is hung, a mast connected to the lower part of the swivel drive mechanism, a pair of buckets rotatably supported on the left and right of the lower part of the mast, and an upper part of the mast, respectively And a pair of hydraulic cylinders interposed between the buckets for rotating the buckets. The turning drive mechanism forms a columnar fixed body that is suspended at the upper part and an opening located at the lower part. The fixed body is inserted into the opening of the driven body so that it can rotate in the circumferential direction, and the fixed body and the driven body are mutually rotated. Swivel clamshell bucket, characterized in that the hydraulic motor is interposed for. 2. A clamshell bucket which is used by being suspended vertically and has a pair of buckets rotating left and right at its lower part, wherein the bucket can grasp earth and sand. A swivel drive mechanism that can be rotated and the upper part is hung, a mast connected to the lower part of the swivel drive mechanism, a pair of buckets rotatably supported on the left and right of the lower part of the mast, and an upper part of the mast, respectively And a pair of hydraulic cylinders interposed between the buckets for rotating the buckets. The turning drive mechanism forms a columnar fixed body that is suspended at the upper part and an opening located at the lower part. The fixed body is inserted into the opening of the driven body so that it can rotate in the circumferential direction, and the fixed body and the driven body are mutually rotated. A plurality of swivel grooves are formed around the fixed body, and each swivel groove communicates with the lower end of an independent cylinder oil passage that penetrates inside the fixed body and extends to the top. The inner circumference of the driven body is formed with a communication oil passage that communicates independently with the swivel groove, and a supply / discharge port of a hydraulic cylinder is connected to each communication oil passage. apparatus. 3. A clamshell bucket which is used by being suspended vertically and has a pair of buckets which are rotatable left and right at a lower part thereof, and wherein the bucket is capable of gripping earth and sand, wherein the upper part and the lower part are circumferentially arranged. A swivel drive mechanism that can be rotated and the upper part is hung, a mast connected to the lower part of the swivel drive mechanism, a pair of buckets rotatably supported on the left and right of the lower part of the mast, and an upper part of the mast, respectively And a pair of hydraulic cylinders interposed between the buckets for rotating the buckets. The turning drive mechanism forms a columnar fixed body that is suspended at the upper part and an opening located at the lower part. The fixed body is inserted into the opening of the driven body so that it can rotate in the circumferential direction, and the fixed body and the driven body are mutually rotated. A plurality of swivel grooves are formed around the fixed body, and a pair of cylinder oil passages and a pair of motor oil passages are drilled in the vertical direction inside the fixed body. Communicates with the lower end of the cylinder oil passage, the lower end of each motor oil passage communicates with the hydraulic motor, and the inner periphery of the driven body forms a communication oil passage that communicates independently with the swivel groove. The communication oil passage is connected to the supply / discharge port of the hydraulic cylinder, and one motor oil passage is connected to the cylinder oil passage on the side that opens the bucket via a pressure control valve that opens when the pressure exceeds a predetermined pressure. This cylinder oil passage is connected to the pressure oil supply / discharge mechanism, and the other motor oil passage is connected to the cylinder oil passage on the side that closes the bucket via a check valve that allows the flow of pressure oil in one direction. Hydraulic circuit of clamshell bucket, characterized in that connecting the cylinder oil passage to the pressure oil supply and discharge mechanism.