JPH047274Y2 - - Google Patents

Description

[Detailed description of the invention] "Industrial application field" This invention relates to an excavator that excavates by connecting drilling rods one after another.

``Prior art'' An excavation tower is erected on a skid, a rotating device is attached to the excavation tower so that it can move up and down, a swinging shaft is rotatably erected on the skid, and a rotating device is attached to the swinging shaft. a holding arm, a rotating shaft rotatably attached to the holding arm, and a rod attached to the rotating shaft and removably holding a plurality of drilling rods spaced apart at an angle about the rotating shaft. a holding mechanism; a rotation mechanism connected to the rod holding mechanism and the holding arm to rotate the rod holding mechanism about the rotation axis; and a rotating mechanism connected to the holding arm and the slit to rotate the rod holding mechanism; (2) A rocking mechanism that rotates around the rocking shaft in a horizontal plane, and the drilling rods are taken out one by one from the rod holding mechanism and pushed down while being rotated by the rotating device. 2. Description of the Related Art Excavators that perform excavation while connecting excavation rods one after another have been known for a long time, as seen in, for example, Japanese Patent Application Laid-open No. 144493/1983.

However, in the case of an excavating device in which the excavating rod take-out position at the excavating position of the rod holding mechanism as shown in FIG. Since the rod holding mechanism exists in front of the power swivel position, it is impossible to drill a hole close to the wall with the drilling rod.

On the other hand, as shown in FIG. 2 of this Japanese Patent Application Laid-open No. 61-144439, the excavated rod take-out position at the excavation position of the rod holding mechanism is the forward position of the rod holding mechanism, and the rod is swung by the swinging mechanism. It is known that drilling equipment configured such that the movement causes the rod retention mechanism to swing rearwardly is capable of drilling holes in close proximity to walls.

In addition, in these conventional devices, there is a structure in which a notch is formed in a part of the rod holding mechanism for putting in and taking out the excavating rod, but this structure It was structured so that it was fixed to a holding arm.

Further, in conventional excavating equipment, the rod is firmly fixed to the rod holding mechanism with a spring or the like, to prevent the drilling rod from tilting on the rod holding mechanism and becoming difficult to rotate when the rod holding mechanism rotates.

``Problems to be Solved by the Invention'' With such a drilling device in which the rod holding mechanism is located in front of the excavation position, it is impossible for the drilling rod to drill an excavation hole close to the wall.

Therefore, the excavating rod is configured such that the excavating rod take-out position at the excavation position of the rod holding mechanism is the forward position of the rod holding mechanism, and the swinging by the swinging mechanism causes the rod holding mechanism to swing rearward. It is desirable to do so.

On the other hand, when mud or the like gets on the drilling rods and problems occur in mutual connection, it becomes necessary to unload the drilling rods from the rod holding mechanism, and it becomes necessary to load the cleaned drilling rods or new drilling rods into the rod holding mechanism. arise. In other words, it becomes necessary to replace the drilling rod.

However, in the above-mentioned conventional device in which the excavation rod take-out position at the excavation position of the rod holding mechanism is set to the front position of the rod holding mechanism, a structure having a notch is fixed to the holding arm, and the notch is fixed to the holding arm. Since it was fixed in one direction, when attempting to replace the excavating rod with the rod holding mechanism in front (i.e. in the excavation position), a power swivel, which is a rotating device, was located above, and this power swivel was not attached. There is also a tower nearby, so if you try to hook the wire to the excavation rod and pull it up with a crane, there is a high risk of damaging the power swivel and the tower.

Moreover, if the excavation rod is to be replaced during excavation work at an excavation location close to a wall, it is necessary to move a crane to the front side. Therefore, it is necessary to retreat the excavator from the excavation position, replace the drilling rod, then return the excavator to the excavation position and reposition it accurately to the hole being drilled. , many work steps are required.

Therefore, even if you try to replace the excavating rod by swinging the rod holding mechanism and moving it backward, the notch in the structure fixed to the holding arm will be removed. Since the rod retaining mechanism is facing forward, the notch in the rod retaining mechanism is still close to the tower in this position, and there is a risk of damaging the power swivel and tower if you hook the excavating rod with a wire and try to pull it up with a crane. It was highly sexual.

Furthermore, in the conventional rod holding mechanism, the rod is firmly fixed to the rod holding mechanism with a spring or the like.
This prevents the drilling rod from tilting on the rod holding mechanism and making it difficult to rotate when the rod holding mechanism rotates, but a mechanism is not provided to change the spring force of the spring mechanism to take out the drilling rod at the digging position. I wasn't there. Therefore, when the drilling rod is connected to a power swivel, which is a rotating device, and the drilling rod is removed from the rod holding mechanism, the spring force acts as resistance, resulting in burrs that require unnecessary force to pull up the drilling rod. There was a high risk of shortening the life of the equipment.

Therefore, the purpose of this invention is to be able to perform the rod replacement work of the rod holding mechanism using a crane or the like from the rear of the equipment with extremely less risk of contact with the tower, etc. To provide an excavator having a rod holding mechanism capable of firmly holding a drilling rod and loosening the holding when taking out the drilling rod.

``Means for solving the problem'' The excavator of this invention has a digging tower set up on a skid, a rotating device attached to the digging tower so that it can move up and down, and the machine is set up on the skid so that it can rotate freely. A swinging shaft, a holding arm attached to the swinging shaft, a rotating shaft rotatably mounted to the holding arm, and a rotating shaft attached to the rotating shaft and angularly spaced apart from each other about the rotating shaft. a rod holding mechanism that removably holds a plurality of drilling rods; a rotation mechanism that is connected to the rod holding mechanism and the holding arm and rotates the rod holding mechanism about the rotation axis; a rocking mechanism connected to the slot and rotating the rod holding mechanism about the rocking shaft in a substantially horizontal plane; This is the forward position of the mechanism, and is configured such that the swinging by the swinging mechanism swings the rod holding mechanism backward, and the drilling rods are taken out one by one from the rod holding mechanism and excavated by the rotating device. In an excavator that excavates by pressing down the rod while rotating and connecting the rods one after another, the rod holding mechanism described above is provided on the top of the rod so that it can rotate independently of the rotation of the rotation shaft. a disk-shaped upper protection plate whose center is fitted into the rotation shaft; a disk-shaped fixed plate provided below the protection plate, whose center is fixed to the rotation shaft and can be rotated by rotation of the rotation shaft; A disk-shaped rotating plate is provided below the fixed plate and whose center is fitted into the rotating shaft so that it can rotate independently of the rotation of the rotating shaft; a support plate fixed to the shaft and on which the lower ends of the rods are positioned at equal angular intervals; It has a structure in which a notch is formed for putting in and taking out the excavation rod, the fixed plate has a structure in which claws are protruded diagonally with respect to the circumferential direction at the above-mentioned equiangular intervals, and the rotating plate has a structure in which the claws are protruded diagonally with respect to the circumferential direction at the above-mentioned equiangular intervals. The rotating plate is reciprocated at a fixed angle with respect to the fixed plate by a cylinder having one side fixed to the fixed plate and the other fixed to the rotating plate. , an excavator characterized in that it has a structure in which the rod can be clamped and released by one claw and one protrusion.

Specific configuration examples of the above-mentioned constituent parts of the drilling equipment of this invention are shown in Figs. 1, 3, 4, and 5.
9, 10, 11, 12, etc., the position of the rod holding mechanism at the excavation position is 15.
Figures 9, 10, and 11 shown in the figures and described above.
The configuration of the specific example shown in FIG. 12 will be mainly explained in the section of the supply mechanism in the embodiments to be described later.

"Function" In this invention, the upper protection plate has a notch formed in a part of the protection plate for putting in and taking out the drilling rod.
Since the center is fitted into the rotating shaft so that it can rotate independently of the rotation of the rotating shaft of the rod holding mechanism, the rod holding mechanism can be swung by the swinging mechanism.
With the rod holding mechanism positioned at the rear, the notch can be turned backward by rotating only this upper protection plate.

Therefore, since the excavating rod can be replaced in this state, the excavating rod can be replaced safely and reliably without moving the position of the excavator itself during excavation.

Further, the excavator of the present invention includes a plate-shaped fixed plate provided below the protection plate, whose center is fixed to the rotating shaft and can be rotated by rotation of the rotating shaft, and a plate-shaped fixed plate provided below the fixed plate, It is equipped with a disk-shaped rotating plate whose center is fitted into the rotating shaft so that it can rotate independently of the rotation of the rotating shaft, and the fixed plate has a structure in which claws are protruded diagonally with respect to the circumferential direction. , the rotating plate has a structure with protrusions at equal angular intervals, and the rotating plate is fixed to the fixed plate by a cylinder having one side fixed to the fixed plate and the other side fixed to the rotating plate. Since it has a structure that allows it to rotate left and right at a certain angle,
By rotating the rotating plate left and right with respect to the fixed plate using this cylinder, it is possible to open or close the gap between the claw of the fixed plate and the protrusion of the rotating plate, and by opening and closing, the drilling rod is held in place. It has become possible to hold and release the hold.

Note that the excavating rod to be taken out is released from the firm hold of the rod holding mechanism at a location where there is a notch in the protection plate. At this time, the firm holding of all the drilling rods other than the one about to be taken out is also released. In such a state, the circumferential jaw provided at the periphery of the protection plate plays the role of preventing any drilling rods other than the one to be taken out from falling down from the rod holding mechanism.

Furthermore, when the fixed plate is rotated by the rotation of the rotating shaft while the excavating rod is held firmly, the rotary plate can be rotated accordingly. Therefore, since the rod holding mechanism can rotate with all the drilling rods firmly held in this way, the drilling rods will not fall down during rotation of the rod holding mechanism and will not impede the rotation.

The same thing can be said about the case where the protection plate is rotated independently of the rotation of the rotating shaft.

Furthermore, the excavating rod in the rod holding mechanism can be firmly held and released regardless of the position of the notch in the protection plate, so no matter where the notch in the protection mechanism is located, the Loading and unloading of the excavation rod at the notched position can be done easily.

"Example" Pile burying procedure Before explaining the excavation/pile burying machine according to this invention, the first step is to explain the procedure of digging a hole and burying a pile in the hole.
This will be explained with reference to the figures. First, as shown in Figure 1A, a hole 12 is dug in the surface soil using an auger 11.
Then, the casing 1 is attached to the periphery of the entrance of the hole 12.
3 to prevent the hole 12 from collapsing, and in this state, the hole 12 is dug down while rotating the drilling rod 16 with the pit 14 attached to the lower end. Drilling is performed using drilling fluid by spraying a mixture of thickeners and other substances under high pressure. As the excavation progresses, the drilling rods 1
While adding 6, excavate, suck up the excavated liquid from hole 12 and take out the excavated soil.
In addition, the inside of the hole 12 is filled with drilling fluid 17. When the hole 12 is excavated to a predetermined depth in this manner, the lowermost end of the hole 12 is expanded to form a bulbous portion 18. During a certain period of time at the beginning of recovery of the drilling rod, the pit 14 is raised and rotated, and the drilling fluid is injected to perform drilling.After forming the bulbous portion 18 with an enlarged hole diameter in this way, the drilling rod is removed. 16
are collected one after another. At this time, the bulb part 18 replaces the drilling fluid with the root hardening fluid, and the portion above it replaces the drilling fluid with the peripheral fixing fluid. After the drilling rod has been recovered as shown in FIG. 1C, the piles 19 are sequentially sunk into the hole 12 as shown in FIG. 1D. This pile 1
9 is, for example, a ready-made reinforced concrete pile. A bag 21 is placed around the outer periphery of this lowermost stake 19. Once the piles 19 have been immersed, cement is poured through the connected piles 19 in sequence as shown in FIG.

Outline The excavating and pile-burying machine of this invention is mounted on a movable body 31, as shown in FIG. The movable body 31 is a tracked vehicle, and a skid (frame) 32 is attached to the movable body 31.
The skit 32 can be held on the ground by outriggers 33.

An excavation tower 34 is erected on top of the skid 32, and a rotating device such as a power swivel 35 is attached to the excavation tower 34 so as to be able to move up and down. This power swivel 35 is driven up and down by a feeding device 36 attached to the upper end of the excavation tower 34. Further, the power swivel 35 can rotate its rotation axis. That is, a drilling rod is attached to the rotating shaft of the power swivel 35 to rotate the power swivel 35, and the power swivel 35 is pushed down by the feeding device 36 to excavate, or a pile is attached to the power swivel 35 and the pile is sunk into the hole.

Furthermore, a feeding mechanism 37 is provided on the skid 32, and the feeding mechanism 37 is capable of holding and moving a drilling rod or pile in a substantially horizontal plane, and its movement causes the drilling rod or pile to be swiveled 32.
It can be brought directly under 5. skit 3
An operation room 38 is provided above the vehicle 2 for an operator to operate the vehicle. Furthermore, a crane 39 is mounted on the skid 32, and by means of the crane 39, piles and drilling rods can be attached to and removed from the supply mechanism 37. Further, various control valves for controlling various cylinders and the like are housed in a valve accommodating portion 41 on the skid 32, and an oil tank 40 for controlling them is provided.

Excavation Position Alignment When excavating, it is necessary to correctly position the excavation rod at the excavation position, but it is difficult to align the excavation rod with high precision only by controlling the movement of the movable body 31. The position of the excavation tower 34 can be precisely controlled within the horizontal plane. Further, in order to perform the excavation correctly and vertically, it is necessary to hold the skit 32 accurately horizontally. First, a positioning means for accurately positioning the excavation tower 34 will be explained.

That is, in this excavating/pile burying machine, as shown in FIGS. 3 to 5, the skit 32 is composed of a lower skit 32a and an upper skit 32b disposed above it, and each of these skits 32a, 3
As shown in FIGS. 6 and 7, 2b has a substantially rectangular shape, and is made into a frame shape to reduce weight. An excavation tower 34 is attached to one end of the upper skid 32b, and the end of the upper skid 32b on the side where the excavation tower 34 is erected is the front side. Further, a semicircular notch 43 is formed at the front end of the upper skit 32b so that a digging rod or the like attached directly below the swivel 35 can pass therethrough.

At least one, in this example two, guide rods 44a, 44b are retained in the lower skid 32a as shown in FIGS. 4 and 7. These guide rods 44a, 44b extend in the front-rear direction, and their rear ends are pivotable about shaft pins 45a, 45b in a substantially horizontal plane. These guide rods 44a, 44b are disposed in holes 46a, 46b formed in the lower skid 32a, and are held in the lower skid 32a so that their front ends can pivot in the left-right direction in FIG. 4 within the holes.

The upper skid 32b is connected to these guide rods 44.
a, 44b and is movable along these guide rods. That is, the retaining rings 47a and 47b are passed over these guide rods 44a and 44b, respectively.
An upper skid 32b is fixed on top of a and 47b. A moving cylinder 49 is attached between a reinforcing piece 48 provided in the middle of the lower skid 32a in the longitudinal direction and the front part of the upper skit 32b, and by expanding and contracting the moving cylinder 49, the upper skit 32b is It can be moved on guide rods 44a, 44b relative to the skid 32a. In other words, the upper skit 32b can be moved in the front-back direction.

Further, a rotation cylinder 51 is connected between the front end of the lower skid 32a and the front end of one of the guide rods 44b, and by expanding and contracting the rotation cylinder 51, the guide rod 44b is pivoted in a horizontal plane. The upper skid 32b rotates about the pin 45b, so that the upper skid 32b rotates relative to the lower skid 32a, and in other words, the excavation tower 34 can be moved in the left-right direction in FIG.

Further, in this example, rings 52a, 52b (52a not shown) are inserted through guide rods 44a, 44b at the rear end of the upper skit 32b, and these rings 52a, 52b are attached to the rear end of the upper skit 32b. cylinder 53
a, 53b, these cylinders 53a,
By strongly pulling up the rod 53b, the positions of the guide rods 44a, 44b can be fixed.

With this configuration, by expanding and contracting the moving cylinder 49, the excavation tower 34 can be moved and adjusted in the front and rear directions, and by expanding and contracting the rotation cylinder 51, the position of the excavating tower 34 in the left and right direction can be adjusted. can be adjusted.

As shown in FIG. 3, the excavation tower 34 is configured so that it can be tilted backwards into a nearly horizontal state as indicated by a dotted line 34' by means of a cylinder 54. In this state, a pin 55 can be inserted to stably hold the upright state. The crane 39 can also be tilted forward in the figure by the cylinder 56, so that it can be tilted almost horizontally. Crane 3
9 can extend and contract its length and can rotate through 360 degrees. The operating chamber 38 is mounted on the upper skid 32b, and the crane 39 is mounted on the lower skid 32a. A structure for holding the skit 32 horizontally for vertically advancing the excavating rod will be described later.

Supply Mechanism A drilling rod or pile is brought under the rotating shaft 57 of the power swivel 35 and connected to it to perform excavation or sinking of the pile.The supply mechanism 37 supplies the drilling rod or pile to the position of the power swivel 35. Do it like this. The supply mechanism 37 can rotate the drilling rod or pile in a horizontal plane from a position below the power swivel 35, and at the appropriately rotated position, the drilling rod or pile can be removed from the supply mechanism by a crane. It is designed so that it can be attached to a mechanism. In this example, the supply mechanism 37 holds a plurality of drilling rods, and is capable of automatically sequentially feeding and recovering the drilling rods.

For this reason, the rod holding mechanism 58 is
As shown in the figure, it is provided on the upper skid 32b so as to be rotatable in a horizontal plane. For example, as shown in FIG. 4, the excavation tower 34 has two guide columns 34a, 3
4b is erected in parallel on the upper skit 32b,
Both ends thereof are connected by a connecting portion 34c, and a swing shaft 59 is rotatably held on one of the guide columns 34b substantially parallel to the guide column 34b as shown in FIG. Holding arms 61a and 61b are attached to the upper and lower ends of the swing shaft 59, respectively, and the rotating shaft 62 is rotatably held between the holding arms 61a and 61b. A circular support plate 63 is fixed to the lower end of the rotating shaft 62 with the rotating shaft 62 inserted through its center, and a protection plate 64 is inserted through the center of the upper end of the rotating shaft 62 to prevent rotation. freely held.

As shown in FIG. 10, the protection plate 64 has a cutout 65 formed in a part thereof for insertion and removal. A temporary fixing mechanism 66 is provided at an intermediate portion of this rotating shaft 62. As shown in FIG. 10, in the temporary fixing mechanism 66, a fixed plate 68 having a claw 67 projecting diagonally with respect to the circumferential direction is fixed to a rotating shaft 69, and a rotating plate 69 rotates in close opposition to the fixed plate 68. It is freely held on the rotating shaft 62. The rotating plate 69 has protrusions 71 at equal angular intervals as shown in FIG. As shown in FIGS. 9 and 11, a fixed plate 68 and a rotating plate 69
A cylinder 72 is installed between the cylinder 7 and
2, the rotating plate 69 can be rotated by a certain angle with respect to the fixed plate. Can be canceled.

As shown in FIG. 9, positioning recesses 73 are formed on the support plate 63 at equal angular intervals, into which the lower end of the excavation rod 16 can be inserted and positioned. Further, a flange 74 is formed on the lower side of the periphery of the protection plate 64. Furthermore, a protective plate 64
A clutch cylinder 75 extending vertically is attached to the clutch cylinder 75, and the upper end of the rod of the clutch cylinder 75 can be inserted into a hole 76 formed in the holding arm 61a and engaged with the holding arm 61a. The lower end of the rod of the clutch cylinder 75 can be selectively inserted into equally spaced holes 78 in a clutch plate 77 fixed to the rotating shaft 62. In other words, when the rod of the clutch cylinder 75 is moved upward, the protection plate 64 is connected to the holding arm 61a, and is disconnected from the clutch plate 77, and vice versa.
When the rod 5 is moved downward, the clutch plate 77
The holding arm 61a is inserted into the hole 78 and connected to the clutch plate 77, and then disconnected from the holding arm 61a.

As shown in FIG. 12, the holding arm 61b and the rotating shaft 6
A rotating cylinder 79 is connected between 2 and 2. A rotating arm 80 is rotatably held on the rotating shaft 62, a cylinder 81 for moving the rod up and down is attached to the rotating arm 80, and a cylinder 82 for moving the rod up and down is attached to the holding arm 61b. The cylinders 81 and 82 have engaging holes 83 formed at equal angular intervals under the support plate 63, as shown in FIG.
can be selectively engaged with. The number of pawls 67, protrusions 71, positioning recesses 73, holes 78 in the clutch plate 77, engagement holes 83, etc. that can be held by the drilling rod, 12 in this example, are provided.

Insert the lower end of the excavating rod 16 into one of the positioning recesses 73 of the support plate 63 at the position of the insertion/removal notch 65, and then press the claw 6 of the temporary fixing mechanism 66.
7 and the protrusion 71. In this state, the cylinder 72 is controlled to hold the excavating rod 16 between the claw 67 and the protrusion 71. Next, the rod of the clutch cylinder 75 is moved upward and its upper end is connected to the hole 76 of the holding arm 61a, that is, the protection plate 6
4 is prevented from rotating, the rod of the cylinder 81 provided on the lower side is projected upward and inserted into the supply hole 83, and the rod of the cylinder 82 is retracted. In this state, when the rotating cylinder 79 is controlled, the rotation cylinder 79 is supported. Board 6
3. The rotating shaft 62 is rotated by a certain angle, for example, 30 degrees,
Since the protection plate 64 is fixed to the holding arm 61a as described above, the excavation rod 16 placed on the support plate 63 and held by the temporary fixing mechanism 66 rotates together with the rotating shaft 62. After that, the rod of the cylinder 81 is retracted, the rod of the cylinder 82 is raised and inserted into the engagement hole 83, and in this state, when the rotating cylinder 79 is reversely controlled, only the rotating arm 80 on the rotating shaft 62 returns. The previously rotated rotational position of the excavation rod 16 can be maintained. In this way, by controlling the cylinders 81 and 82 in the opposite direction and controlling the rotating cylinder 79, the drilling rod 16 disposed on the support plate 63 is rotated to the inside of the circumferential jaw 74 of the protection plate 64. let Even if the holding by the temporary fixing mechanism 66 is released in this state, the upper end of the excavating rod 16 will not fall down due to the presence of the periphery 74 of the protection plate 64.
The drilling rod 16 is held between the support plate 63 and the support plate 63. In this way, the drilling rod 16 is moved at an angle of, for example, 30°.
Twelve pieces can be held around the rotating shaft 62 at angular intervals.

A pile holder 84 is held at the intermediate portion of the rotating shaft 62, and by controlling a movable portion 84a of the pile holder 84 with a cylinder 85, the pile 19 can be held in place. With the lower end of the clutch cylinder 75 inserted into the hole 78 of the clutch plate 7 as shown in FIG.
1 and 82 and the cylinder 79, the entire rod holding mechanism 58 can be rotated about the rotation shaft 62. In other words, the angular position of the insertion/removal notch 65 can be arbitrarily set with respect to the holding arm 61a.

As shown in FIGS. 9 and 12, a swinging cylinder 86 is attached between the guide column 34b of the excavation tower and the end of the holding arm 61b, and by controlling the swinging cylinder 86, the rod is The entire holding mechanism 58 can be rotated around a swing shaft 59. In other words, the rod holding mechanism 58 can be rotated, for example, by about 90 degrees in a substantially horizontal plane.
As a result of this rotation, the rod holding mechanism 58 can be rotated to a position directly below the swivel 35 as shown in FIGS. 4 and 5, or to a position away from it, that is, toward the crane 39 side. I can do it. Therefore, the drilling rod 16 and the pile 19 can be held by the rod holding mechanism 58 from any position (direction), not only from the front end of this machine, that is, from the excavation position by the drilling rod or from the position where the pile is sunk. let me,
Further, a crane can be used to remove the pile from the rod holding mechanism 58 or to hold the stake in the rod holding mechanism.

Chucking Furthermore, in this machine, the digging rod 16 can be attached to or detached from the power swivel automatically or by remote control, and the stake 19 can also be attached to the power swivel 35.
As shown in FIGS. 3 and 4, a power swivel mount 88 is installed between the guide columns 34a and 34b so that it can be moved up and down while being guided by the guide columns 34a and 34b.
is installed. Below the power swivel mount 88, a tracking mount 89 is connected to the power swivel mount 8 by cylinders 91a and 91b.
It is installed so that it can be moved up and down relative to 8.
The tracking mount 89 also has guide columns 34a, 3
4b and is guided and held so as to be able to move up and down.

Chat King mount 89 and Chat King 91
is held, and the rod holding mechanism 58 is moved to the power swivel 3 as shown in FIGS. 15, 16, and 16A.
5, one drilling rod can be inserted through the chucking 91, and the drilling rod 16 can be gripped by the chucking 91.
The chucking mount 89 is a rod holding mechanism 58
It is located on the outer periphery so as not to get in the way.

The chuck 91 can be rotated while gripping the excavation rod 16. That is, the cylindrical rod guides 90a, 90b are arranged vertically and coaxially and attached to the chucking mount 89, and the cylinder 92 and the engaging piece 94 are arranged vertically in the openings formed in the rod guides 90a, 90b. The cylinder 9 is held rotatably around the
2 is a rod guide 90a, 90b through the opening.
In other words, the rod guide 90a,
The excavating rod inserted through 90b can be held by the cylinder 92 against the engagement piece 94 and gripped. The engagement piece 94 protrudes forward and engages the movable cylinder 9.
It engages with a protrusion 96 fixed to the tube of No. 5. The movable cylinder 98 is held by a chucking mount 89 so as to be able to move left and right, and rods 95a and 95b on both sides thereof are fixed to the chucking mount 89. Therefore, if hydraulic pressure is supplied to the rod 95a side of the movable cylinder 95 in the figure, and the hydraulic pressure is reduced to the rod 95b side, the tube of the movable cylinder 95 moves to the right in the figure, and the excavating rod 16 gripped by the cylinder 92b moves to the right in the figure. It will rotate counterclockwise.
To rotate the excavating rod in the opposite direction, hydraulic pressure may be supplied to the rod 95b side of the cylinder 95.
Note that the tracking mount 89 has a hole 97 through which a chain, which will be described later, passes.

Therefore, one of the excavating rods 16 is positioned directly below the rotating shaft 57 of the swivel, and at that position, the insertion/removal notch 65 in the holding plate 64 of the rod holding mechanism is opposed to the chucking 91, and in this state, the cylinder 91a is , 91b to position the chucking mount 89 below the holding plate 64, and one drilling rod 16 held by the rod holding mechanism 58 is inserted into the hole 98 of the chucking 91. Thereafter, the cylinders 92a and 92b are controlled to grip the drilling rod 16, and in this state, the chucking mount 89 is moved to the cylinders 91a and 92b.
91b to bring it closer to the swivel mount 88, that is, bring one of the digging rods 16 gripped by the chucking 91 closer to the rotating shaft 57 of the swivel 35, and by rotating the swivel 35, the lower end of the swivel rotating shaft 57 A male thread 99 formed at the top of the drilling rod 16 is screwed into a female thread 101 (FIG. 17) formed at the upper end of the drilling rod 16 to connect the drilling rod 16 to the swivel rotation shaft 57. The rod holding mechanism 58 is rotated to remove anything other than the connected drilling rod from the position of the power swivel 35. Hereinafter, removing the rod holding mechanism 58 from directly below the power swivel will be referred to as a return operation. After that, lower the power swivel, bring the drilling rod connected to the power swivel close to the upper end of the drilling rod that is already in the ground, and rotate the power swivel 35 to remove the male screw formed at the lower end of the newly connected drilling rod. 102 (FIG. 17) is screwed and connected to the upper female thread 101 of the uppermost drilling rod that has already been inserted into the ground. In this case, in order to complete the connection, the excavation rod located underground is held by a rod clamp.

Rod Clamp As shown in FIGS. 3 and 4, the rod clamp 103 has cylinders 104a and 104b attached to the upper skid 32b on both sides of the notch 43 shown in FIG. 7 at the front end position of the upper skid 32b (see FIG. 18). , see FIG. 19), the rods of the cylinders 104a and 104b are equipped with a presser 105.
a, 105b are attached, and these pressers 105
The opposing surfaces of a and 105b form a substantially common cylindrical surface, and the axial direction of the cylindrical surface is the vertical direction of the swivel rotation axis. There is a guide piece 1 on the upper side of the pressers 105a and 105b.
06a and 106b are respectively fixed, and a drilling rod suspended from a swivel rotating shaft 57 is guided between these guide pieces 106a and 106b so that it can descend.

Further, each tube of the cylinders 104a, 104b is extended toward the pressers 105a, 105b, respectively, to form extensions 107a, 107b, and the pressers 105a, 105b are fitted into these extensions and guided thereto. In this case, the extension portions 107a and 107b facing the guide pieces 106a and 106b are provided with the grooves shown in FIG.
As shown in FIG. 18A and FIG. 19A, the notch 10
8 is formed. The guide pieces 106a and 106b are guided by the notch 108, and the cylinder 1
Even when the rods 04a and 104b are expanded and contracted, the rods do not rotate, and the guide pieces 106a and 106b always face each other and are located on the upper side. Presser 105
A drilling rod is located between a and 105b,
The drilling rod 16 is connected to the cylinders 104a, 104.
b can be held and fixed by controlling
In this fixed state, the swivel 35 can be rotated to connect the excavating rod connected to the swivel rotating shaft 57 above and the excavating rod held by the rod clamp 103 through a screw connection. At this time, the rod clamp 103 receives the rotational force, but the rotational force is applied to the holding tools 105a and 105.
b and the extensions 107a, 107b, and hardly reach the rods of the cylinders 104a, 104b, so there is no risk that the seals of the cylinders will be deteriorated by the rotational force. In this example, the fixed pieces 110a, 110b of the guide pieces 106a, 106b are located in the notch 108, and the rotation of the guide pieces is prevented.

As shown in FIGS. 3 and 19, an elastic ring 109 made of rubber is attached to the holding tool 1 directly below the holding tools 105a and 105b of the rod clamp 103.
11 is fitted and held. The elastic ring 10
9, a drilling rod held by a swivel 35 is positioned so as to be inserted therethrough in resilient contact. Therefore, when the drilling rod 16 is recovered, the drilling rod passes through the elastic ring 109, so the mud attached to the drilling rod 16 is removed, and the chuck 91 and the rod clamp 10 are removed.
3 can be reliably maintained.

The excavating rod is held by the rod clamp 103, and the swivel 35 is made freely rotatable, and the chuck 91 grasps the excavating rod connected to the swivel rotating shaft to control the movable cylinder explained in FIGS. 15 and 16. By doing so, the upper drilling rod can be rotated, ie the threaded connection between the upper drilling rod and the drilling rod held by the rod clamp 103 can be loosened. In the loosened state, the holding by the chuck 91 is also loosened, and by rotating the swivel 35 in the opposite direction, the excavating rod held by the rod clamp 103 and the swivel rotating shaft 5 are removed.
7, and then connect the excavating rod to the swivel rotation shaft 57 by performing the reverse operation of connecting the excavation rod from the rod holding mechanism 58 to the swivel rotation shaft 57. By holding the excavating rod in the rod holding mechanism 58, the excavating rod can be recovered.

Since the rod clamp 103 becomes an obstacle when burying the pile, the rod clamp 103 is designed to be able to be removed from the above-mentioned position. That is, as shown in FIG. 18, FIG. 18A, and FIG. 19, the rod clamp 103 (cylinder 104a,
104b) is mounted on the movable plate 301, and the movable plate 301 has guide rails 302a, 3 on both sides.
02b and is held so that it can move back and forth on the upper skid 32b, and the movable plate 301
By controlling the cylinder 303 connected between the upper skid 32b and the upper skit 32b, the movable plate 301 can be retracted to the dotted line position in FIG.
An elastic ring 109 is also attached to the movable plate 301.

As shown in FIG. 19, a flange 16a is formed in the middle of the pitted excavation rod, and the excavation rod is attached to a power swivel with an elastic ring 109 passed through it.
is positioned at the height of the holder 111, move the rod clamp 103 forward, and
An elastic ring 109 can be fitted within 1. Moreover, when the excavation rod is recovered, the elastic ring 109 can also be recovered by performing the reverse operation.

As shown in FIGS. 3 to 5, the excavation tower 34
A feeding device 36 is attached above, that is, on the connecting portion 34c, and the feeding device 36 has, for example, a sprocket 114 attached to the rotating shaft of a hydraulic motor 113, and the sprocket 114 is a large sprocket attached to a drive shaft 115. The drive shaft 115 is connected to the sprocket 116 by a chain 117 to reduce the speed, and the sprocket 1 is attached to both ends of the drive shaft 115.
Chains 119a and 119b are attached to these sprockets 118a and 118b, respectively, to further reduce the speed. One end of each of the chains 119a, 119b is fixed to the swivel mount 118, and the other end goes around the sprockets 121a, 121b attached to the lower ends of the guide columns 34a, 34b, respectively, and further extends through the hole 97 of the tracking mount 89. through which it is fixed to a swivel mount 88. Therefore, the hydraulic motor 113 of the feeding device 36
is rotated in one direction to lower the swivel mount 88, and rotated in the opposite direction to raise the swivel mount 88. In this way, the swivel 35 can be moved up and down. A rotary encoder 122 is mounted, for example, on the rotation shaft of the hydraulic motor 113 in order to measure the vertical amount of the swivel 35 and to measure the depth of excavation by the excavation rod.

The power swivel swivel 35 has a hydraulic motor 124 mounted on a swivel mount 88, and a gear 125 mounted on its rotating shaft as shown in FIG.
The gear 125 is meshed with a large gear 126, and the rotating shaft on the large gear 126 is a swivel rotating shaft 57.
is connected to. Therefore, the rotation of the hydraulic motor 124 causes the swivel rotation shaft 57 to rotate at a reduced speed. The rotation amount and rotation speed at this time can be measured by a rotary encoder 128 connected to the gear 125.

Further, in this machine, excavation is performed by rotating the pit 14 (FIG. 1B) and at the same time by injecting a high pressure drilling fluid. For that purpose, the swivel rotation axis 5
7 is a double tube as shown in FIG. 20, and an inner tube 129 with a hole in the center passes through it.
A cylindrical passage 132 is formed between the outer tube 131 and the outer tube 131, and the outer tube 131 protrudes above the case 133 of the large gear 126, and a joint portion 134 is rotatably covered over the protruding end thereof. . Passage 13
A high pressure pipe connection part 135a is provided at the upper end of the joint part 134 and a low pressure pipe connection part 135 is provided at the side of the joint part 134 in order to supply liquid from the outside into each of the joint parts 134 and 2.
b are provided respectively.

A high-pressure drilling fluid is supplied into the inner pipe 129, and a large amount of peripheral fixing fluid, cement milk, etc. is supplied to the cylindrical passage 132 at low pressure. High-pressure drilling fluid and cylindrical passage 13 from inside the inner pipe 129 of the swivel rotating shaft inside
Drilling rod 16 is also connected to the first
As shown in Figure 7, it is a double pipe.

Pile Connection Jig In order to connect the pile to the power swivel 35, a pile connection jig is connected to the power swivel 35. The pile connection jig 137 has a substantially cylindrical shape as shown in FIG.
39, and a connecting female screw 141 is fixed at the center of the upper plate 139.
1 allows the male thread 99 of the rotating shaft of the power swivel or the lower end male thread 102 of the drilling rod to be screwed together. Furthermore, in this example, this jig 1
37 can also be used to connect the final pile and the power swivel, and a cylindrical female screw 142 is removably attached to the inner peripheral surface of the cylindrical body 138 by a screw 143. The cylindrical female thread 14
2 can be screwed to the male thread 144 at the upper end of the pile 19. In other words, as shown in FIG. 22, the pile 19 has a male thread 144 formed at its upper end, a female thread 145 that can be screwed together with this male thread 144 at its lower end, and the pile 19 has a central hole through it.

On the other hand, the final pile, that is, the pile to be buried at the top, has a cylindrical protrusion 146 having a smaller diameter than the outer circumferential diameter protruding from its upper end, as shown in FIG. 21B, for example. A pair of pins 147 are protruded and fixed 180° apart from the side surfaces of. In the pile connection jig 137, an inner cylinder 148 is attached concentrically to the inside of a cylindrical body 138.
As shown in FIG. ) can be inserted and coupled with the pin 147 of the final pile 19.

Pile Clamp As shown in FIGS. 3, 4, and 23, a pile clamp 151 is provided below the rod clamp 103. This pile clamp 151 is provided with a rotating arm 153 that is rotatable around a shaft 152.
One end of the arm 153 is connected to a cylinder 154, and a pile presser 155 is attached to the other end of the arm 153. The pile presser 155 is shaped to follow the circumferential surface of the pile 19. Such a rotating arm 15
3. A pair of cylinders 154 and pile pressers 155 are provided facing each other. Both cylinders 154
By controlling this, the stake 19 can be held between both sides.

When connecting the pile 19 to the swivel rotation shaft 57 in the same way as when connecting the excavation rod 16 to the swivel rotation shaft 57, attach the pile connection jig 13 to the rotation shaft 57 in advance.
7 is connected, and in this state, the pile 19 is held by the pile presser 84 of the rod holding mechanism 58, and in this state, the pile connecting jig 137 is rotated and held by the rotation of the swivel 35. Connect by screwing together. Thereafter, the lower pile is held by the pile clamp 151, and in this state, the swivel is lowered and rotated, and the upper pile connected to the swivel is screwed to the lower pile.

Horizontal Control Next, control for holding the skit 32 horizontally will be explained. For example, as shown in FIG. 24, the outriggers holding the skit 32 are the front outriggers 33a, 33b and the rear outriggers 3.
Let us take as an example the case where it is held by four outriggers 3c and 33d. An inclinometer is provided at the intersection of two intersecting straight lines, but in this example, the inclinometer 1 is installed on the line 161 connecting the outriggers 33a and 33d.
62 is provided, and the straight line 16 is determined by the inclinometer 162.
1 to detect the inclination angle with respect to the horizontal plane,
Further, the inclination of a line 163 perpendicular to this line 161 with respect to the horizontal plane is detected by an inclinometer 162. Inclinometer 16
The support section 2 is provided within the operation chamber 38 in FIG. 3, for example.

The outriggers 33a and 33d are controlled to be horizontal by the inclinometer 162 in accordance with the detected inclination angle of the straight line 161 with respect to the horizontal plane. Then, by controlling one of the outriggers 33a and 33d such that, for example, one of the outriggers 33a and 33d is raised and the other is lowered using the ratio a:d, the straight line 161 is made horizontal with a small amount of control. In addition, in order to correct the inclination of the straight line 163 with respect to the horizontal plane, a line connecting the outriggers 33b and 33c is drawn as a straight line 163.
Outriggers 33b, 33c when projected on 63
Similarly, the outriggers 33b and 33c are controlled in opposite directions corresponding to the distances b and c between the inclinometer 163 and the inclinometer 163. In other words, the intersection between the line connecting the outriggers 33b and 33c and the straight line 161 and the outriggers 33b, 3
The inclination of the straight line 163 with respect to the horizontal plane may be corrected according to the distances b' and c' between the lines 3c.

Control of these outriggers 33a to 33d is performed at high speed when the outriggers are first extended, and correction control for slight deviations for maintaining the horizontal position is performed little by little with high precision. From this point of view, the drive cylinder 164a is connected to the outriggers 33a to 33d by 164d (FIG. 25).
Switching valves 165a to 165d for raising and lowering the outriggers are provided in hydraulic passages for each cylinder, respectively, and a high-speed control valve 166 is inserted in a hydraulic passage common to these vertical switching valves 165a to 165d. A low speed control valve 167 is provided in parallel with this valve 166. Furthermore, high-speed control valve 1
A pressure switch 168 that detects the oil pressure in the oil pressure passage on the side of the switching valves 165a to 165d of 66
is provided. The pressure switch 168 switches from control by the valve 166 to control by the valve 167 when the detected hydraulic pressure exceeds a predetermined value.

"Effects of the invention" As described above, according to the excavator according to this invention, the position for taking out the excavating rod at the excavation position of the rod holding mechanism 58 is set to the front position of the rod holding mechanism 58, and the rocking mechanism 58 swings the excavating rod. Although this is an excavator that takes advantage of the characteristic effect of being able to drill an excavation hole in a position close to a wall, which conventional excavators have which is configured so that the rod holding mechanism 58 swings backward when the rod is moved. , the protection plate 6 in which a notch 65 for taking in and out the excavation rod is formed in a part thereof;
Since the center of the rod holding mechanism 58 is fitted into the rotating shaft 62 so that it can rotate independently of the rotation of the rotating shaft 62 of the rod holding mechanism 58, the rod holding mechanism 58 can be swung by a swinging mechanism, for example, 90 degrees. Then, with the rod holding mechanism 58 positioned at the rear, only the upper protection plate 64 can be rotated, for example, by about 120 degrees to 150 degrees, so that the notch 65 faces toward the rear.

Therefore, since the drilling rod 16 can be replaced in this state, there is no need to move the position of the excavator itself during the excavation work, and even if a crane is used during the replacement work of the drilling rod 16, the excavator rod 16 can be lifted by the crane. There is little risk of the drilling rod hitting the tower 34, etc., and the drilling rod 16 can be replaced safely and reliably.

In this way, the replacement work of the drilling rod 16 can be carried out from the rear side, so that when the drilling rod is connected during excavation work, mud etc. will get on the threaded connection part of the drilling rod and it will be necessary to replace the drilling rod. Also, since a new drilling rod can be loaded into the rod holding mechanism 58 and replaced with an old drilling rod without moving the excavator, the efficiency of drilling a drilling hole is higher than that of conventional equipment.

Further, in the excavator of the present invention, the protection plate 64
A disk-shaped fixed plate 68 is provided at a lower portion, the center is fixed to the rotating shaft 62, and can be rotated by the rotation of the rotating shaft 62; It is equipped with a disc-shaped rotating plate 69 whose center is fitted into the rotating shaft 62 so as to be able to rotate independently, and the fixed plate 68 has a structure in which a claw 67 is protruded diagonally with respect to the circumferential direction. The rotary plate 69 has a structure in which the rotary plate 69 has protrusions 71 at equal angular intervals, and the rotary plate 69 is rotated by a cylinder 72 whose one side is fixed to the fixed plate 68 and the other side is fixed to the rotary plate 69. The above fixed plate 68
This cylinder 72
By rotating the rotating plate 69 left and right with respect to the fixed plate 68, the distance between the claw 67 of the fixed plate 68 and the protrusion 71 of the rotating plate 69 can be opened or closed. It is possible to firmly hold the drilling rod 16 in the holding mechanism 58 and to release it.

Therefore, the drilling rod 1 is removed from the rod holding mechanism 58.
6, for example, by connecting the drilling rod 16 to the power swivel 35, which is a rotating device, and taking out the drilling rod 16 from the rod holding mechanism 58, this holding state can be released and the work can be carried out.
During this work, no excessive force is applied to the rod holding mechanism 58, and no excessive force is applied to the power swivel 35 side, which is a rotating device, so all parts attached to the excavation equipment will not be damaged. Extends equipment life.

Also, the drilling rod 16 is inserted into the rod holding mechanism 58.
For example, when recovering the excavating rod 16 after the excavation work is completed, the excavating rod 16 is connected to the power swivel 35, which is a rotating device, and is separated from the lower excavating rod, and then removed from the inside of the rod holding mechanism 17. When inserting the rod into the rod holding mechanism 17, the work can be done with the claw 67 of the fixed plate 68 and the protrusion 71 of the rotary plate 69 in the rod holding mechanism 17 open. Therefore, since no excessive force is applied during this operation, all parts attached to the excavation equipment will not be damaged, and the life of the equipment will be extended.

In addition, when replacing the excavating rod 16 like this, the excavating rod 16 to be taken out must be removed from the protective plate 6.
It is carried out at a place where there is a notch 65 of No. 4, and is carried out in a state where it is released from the firm holding of the rod holding mechanism 58. Therefore, at this time, the firm holding of all the drilling rods other than the one about to be taken out is also released. In such a state, the peripheral jaws provided at the periphery of the protection plate 64 play a role in preventing any drilling rods other than the one to be taken out from falling down from the rod holding mechanism 58.

Further, when the excavating rod 16 is returned to the firmly held state and the fixed plate 68 is rotated by the rotation of the rotating shaft 62, the rotating plate 69 can be rotated accordingly. Therefore, since the rod holding mechanism 58 can rotate with all the excavating rods 16 firmly held, the excavating rods 16 will not fall down during the rotation of the rod holding mechanism 58 and will not impede the rotation.

The same thing can be said about the case where the protection plate 64 is rotated independently of the rotation of the rotating shaft 62.

Furthermore, since the drilling rod 16 in the rod holding mechanism 58 can be held firmly or in an open state regardless of the position of the notch 65 of the upper protective plate 64, the notch 65 of the upper protective plate 64 can be positioned at any position. However, loading and unloading of the drilling rod 16 at the notch position,
Loading work can be done easily.

As described above, in the excavator of the present invention, the excavation rod take-out position of the rod holding mechanism 58 at the excavation position is
It is possible to drill an excavation hole in a position close to the wall of a conventional drilling rig, which is positioned in front of the rod holding mechanism 58 and is configured such that the swinging by the swinging mechanism causes the rod holding mechanism 58 to swing rearward. Although this is an excavator that takes advantage of the characteristic effect that it is possible to replace the excavating rod 16 of the rod holding mechanism 58 using a crane or the like, it is possible to carry out the work of replacing the excavating rod 16 of the rod holding mechanism 58 with extremely reducing the risk of contact with the tower etc. It has the advantage of being able to perform drilling from the rear of the equipment, and even if the drilling rod connection fails for some reason, the drilling rod can be replaced without moving the excavator, making it easier to drill holes than with conventional equipment. It also has the effect of improving efficiency.

Moreover, the drilling rod can be firmly held when the rod holding mechanism is rotated, and the holding can be loosened when taking out the drilling rod, so there is less risk of damaging the equipment during these operations, and the rod holding mechanism 58 is rotated. All of the excavating rods 16 can be firmly held inside, etc., and there is also the excellent effect that there is little risk of damage to the equipment during rotation work or the like.

[Brief explanation of the drawing]

Figure 1 is a sectional view to explain the excavation and pile burying process, Figure 2 is a perspective view showing the external appearance of the excavation and pile burying machine according to this invention, and Figure 3 is a side view of the excavation and pile burying machine. , FIG. 4 is a right side view of FIG. 3, FIG. 5 is a plan view of FIG. 3, FIG. 6 is a side view showing the connection state of the lower and upper skits, and FIG. Plan view, Figure 8 is a sectional view taken along line AA in Figure 6,
FIG. 9 is a longitudinal cross-sectional view showing an example of the supply mechanism, and FIG.
The figure is a plan view of Fig. 9, Fig. 11 is a sectional view taken along the BB line of Fig. 9, Fig. 12 is a sectional view taken along the CC line of Fig. 9, and Fig. 11 is a sectional view taken along the line CC of Fig. 9.
Figure 3 is a sectional view taken along the DD line in Figure 9, and Figure 14 is a cross-sectional view of Figure 13.
15 is a plan view of the chucking 91, FIG. 16 is a front view of the chucking 91, FIG. 16A is a sectional view taken along the line PP of the chucking 91, FIG. Figure 18 shows rod clamp 1
Figure 18A is a cross-sectional view of the right half of Figure 18, Figure 19 is a front view of Figure 18, with a portion of Figure 18 as a cross-section, Figure 19A is a cross-sectional view of Figure 19. FF line sectional view, FIG. 20 is a front view with half of the power swivel 35 in cross section, FIG. 21 is a sectional view showing the pile joining jig 137, and FIG. Figure B shows the state of connection with the final pile, and Figure C shows the state in which Figure B is rotated by 90 degrees.
FIG. 22 is a front view showing the intermediate pile, FIG. 23 is a plan view showing a part of the pile clamp 151, FIG. 24 is a plan view showing the relationship between the outrigger and the inclinometer, and FIG.
The figure is a diagram showing the relationship between the drive cylinder and the switching valve with respect to the outrigger.

Claims (1)

[Scope of Claim for Utility Model Registration] An excavation tower is erected on a skid, a rotating device is attached to the excavation tower so that it can move up and down, a swing shaft that is rotatably erected on the skid, and its swing. A holding arm attached to a shaft, a rotating shaft rotatably attached to the holding arm, and a plurality of drilling rods attached to the rotating shaft and detachable at an angular distance about the rotating shaft. a rotating mechanism connected to the rod holding mechanism and the holding arm to rotate the rod holding mechanism about the rotation axis; and a rotation mechanism connected to the holding arm and the squitt to hold the rod. a rocking mechanism that rotates the mechanism about the rocking shaft in a substantially horizontal plane, and the digging rod take-out position at the digging position of the rod holding mechanism is a forward position of the rod holding mechanism; The rocking mechanism is configured so that the rocking mechanism swings the rod holding mechanism backward, and the drilling rods are taken out one by one from the rod holding mechanism, and the rotating device pushes down the digging rods while rotating. In an excavator that excavates while connecting drilling rods one after another, the above-mentioned rod holding mechanism is provided at the top, and the center is fitted into the rotating shaft so that it can rotate independently of the rotation of the rotating shaft. a disk-shaped upper protection plate provided below the protection plate, the center of which is fixed to the rotation shaft, and which can be rotated by rotation of the rotation shaft; a disk-shaped fixed plate provided below the fixed plate, A disc-shaped rotating plate whose center is fitted into the rotating shaft so that it can rotate independently of the rotation of the rotating shaft; a support plate on which the lower end of the rod is positioned and mounted, and the upper protection plate has a circumferential jaw formed on the lower side of its periphery, and a part of the protection plate has a notch for putting in and taking out the excavation rod. The fixed plate has a structure in which claws are protruded diagonally with respect to the circumferential direction at the above-mentioned equal angular intervals, and the above-mentioned rotating plate has a structure in which protrusions are formed at the above-mentioned equal angular intervals. With a cylinder, one of which is fixed to the fixed plate and the other to the rotating plate, the rotating plate is reciprocated at a certain angle with respect to the fixed plate, so that one pawl and one An excavator characterized in that the excavator is equipped with a structure that allows the rod to be clamped and released by the protrusion.