JPH11303564A - Clamp device and pit excavator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the reliability of a clamp device and a pit excavator by securely clamping a tubular member such as a casing tube in the pit excavator. SOLUTION: In a lower clamp device 14A, a plurality of clamp arms 33a, 33b, 33c, 33d of which inner peripheral faces form an arc shape are connected by connection shafts 34a, 34b, 34c so as to turn freely, and a clamp ring 32 forming a ring shape in which a casing tube can be inserted is constituted so as to expand and shrink by connecting the clamp arms 33c, 33d by a clamp cylinder 13. Lower parts of the connection shafts 34a, 34b, 34c are engaged with guide holes 36a, 36b, 36c formed in a receive plate 31 of a base frame 12 so that this clamp ring 32 operates using a central point of the casing tube as reference at the time of expansion and shrinkage operation of the clamp ring 32.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shaft excavator used for discharging earth and sand, rocks, and wood in shaft excavation and foundation pile formation.

[0002]

2. Description of the Related Art An all-casing excavator as a shaft excavator is used, for example, when excavating a shaft, and clamps a casing tube, and turns or swings the casing tube underground while excavating. , The ground is cut by the cutter bit at the lower end, and the crane is operated to excavate and discharge the earth and sand in the casing tube by the grab bucket to form a shaft.

FIG. 10 is a front view showing an operating state of a general all-casing excavator, FIG. 11 is a front view showing a casing tube extracting state of the all-casing excavator, and FIG. 12 is a conventional lower clamping device in the all-casing excavator. FIG.

In a general all-casing excavator, as shown in FIG. 10, a casing tube 10 has a first tube 1 having a cutter bit 10a at a lower portion.
A plurality of connecting tubes 10c are connected to the connecting tube 10b by lock pins 10d. On the other hand, at a predetermined position on the ground G, a gantry 11 having a rectangular top view is installed,
A base frame 12 is installed on the gantry 11. This base frame 12 has a casing tube 1
A lower clamp device 14 having a clamp cylinder 13 capable of clamping the outer peripheral portion of the “0” is mounted. An elevating frame 16 which can be moved up and down by an elevating cylinder 15 is connected to the base frame 12. An upper clamp device 18 having a clamp cylinder 17 capable of clamping the outer periphery of the casing tube 10 is mounted on the lifting frame 16, and the upper clamp device 18 is pivotally supported by a pivot device 20 having a pivot motor 19. Have been.

A crane (not shown) is provided above the crane. A crown 22 is connected to an end of a main winding wire rope 21 drawn from the crane.
The auxiliary wire rope 23 passes through the crown 22 and is lowered into the casing tube 10, and the excavating bucket 24 is connected thereto.

Accordingly, in order to perform shaft excavation using this all-casing excavator, the clamp cylinder 17 is contracted at a position where the lifting cylinder 15 is extended and the lifting frame 16 is raised, and the casing tube 10 is moved by the upper clamping device 18. Clamp. In this state, while the casing tube 10 is swung by the swivel device 20 by driving the swivel motor 19, the elevating cylinder 15 is contracted and the elevating frame 16 is lowered, whereby the casing tube 10 is pushed into the ground and the cutter 10a The ground G is cut by this. By operating the crane, the excavated soil in the casing tube 10 is discharged by the excavation bucket 24 to form a shaft. Thereafter, when the shaft reaches a predetermined depth, a steel cage (not shown) is put in the casing tube 10 and the casing tube 10 is gradually pulled out while injecting raw concrete to construct a foundation pile.

That is, as shown in FIG. 11, the casing tube 10 is clamped by the lower clamping device 14 at the position where the lifting cylinder 15 is extended and the lifting frame 16 is raised, while the casing tube 10 is clamped by the upper clamping device 18. Release the clamp. Then, the elevating cylinder 15 is contracted to lower the elevating frame 16, and the casing tube 10 is clamped by the upper clamp device 18, while the casing tube 10 is released from being clamped by the lower clamp device 14. When the elevating cylinder 15 is extended and the elevating frame 16 is raised, the casing tube 10 clamped by the upper clamp device 18 can be pulled out by a predetermined length.
By this repetitive operation, the entire casing tube 10 can be pulled out.

In the lower clamp device 14 of the above all-casing excavator, as shown in FIG. 12, a ring-shaped clamp ring 32 is disposed on a receiving plate 31 provided on the inner peripheral side of the base frame 12. It is configured. The clamp ring 32 includes four clamp arms 33a, 33b, 33c, and 33d each having an arcuate inner peripheral surface.
Are rotatably connected by three connecting shafts 34a, 34b, 34c, and the ends of the clamp arms 33c, 33d are connected by a clamp cylinder 13. The lower part of the connecting shaft 34a is a receiving plate of the base frame 12. 31 is supported. Therefore, the clamp cylinder 13
Is contracted, so that each clamp arm 33a, 33b,
While the casing tube 10 can be clamped by reducing the inner diameter of the clamp ring 32 composed of 33c and 33d, the inner diameter of the clamp ring 32 is increased by extending the clamp cylinder 13 to release the clamping of the casing tube 10. Can be.

[0009]

As described above, in the conventional lower clamp device 14 described above, the clamp ring 32 is formed by the clamp arms 33a, 33b, 33c, 33.
d is connected by connecting shafts 34 a, 34 b, 34 c and the clamp cylinder 13, and the connecting shaft 34 a is supported by the receiving plate 31 of the base frame 12. Then, the inner diameter of the clamp ring 32 expands and contracts as the clamp cylinder 13 expands and contracts. This expansion and contraction operation is performed with the connection shaft 34a as a fulcrum. Therefore, it is affected by the positional accuracy in manufacturing the lower clamp device 14, the roundness and straightness of the casing tube 10, or the shift or inclination of the installation position of the all-casing excavator.
As shown in FIG. 2, the center position of the clamp ring 32 and the center position of the casing tube 10 may be shifted.
In this case, even if the inner diameter of the clamp ring 32 is reduced by contracting the clamp cylinder 13, the casing tube 1
There is a problem that 0 may not be clamped and the reliability is not sufficient.

An object of the present invention is to solve such a problem, and an object of the present invention is to provide a clamp apparatus and a shaft excavator which improve reliability by securely clamping a tubular member such as a casing tube. And

[0011]

According to a first aspect of the present invention, there is provided a clamp device for clamping an outer peripheral portion of a tubular member. A hollow base frame having a receiving plate, a clamp ring having a ring shape through which the tubular member can be inserted by rotatably connecting a plurality of clamp arms having an arcuate inner peripheral surface by a connection shaft; A fluid cylinder capable of expanding and contracting the inner diameter of the clamp ring; and guide means for guiding the clamp ring on the receiving plate so that the clamp ring operates with a predetermined center point being substantially used as a reference during the operation of expanding and contracting the clamp ring. It is characterized by the following.

Further, in the clamp device according to the second aspect of the present invention, the guide means has the connecting shaft and a guide hole formed in the receiving plate and engaged with the connecting shaft.

According to a third aspect of the present invention, the guide means has a guide projection suspended from the clamp arm and an inner end surface of the receiving plate with which the guide projection engages. I have.

According to a fourth aspect of the present invention, there is provided a shaft excavator, comprising: a casing tube having a cutter at a lower part; a hollow base frame mounted on a gantry and having a receiving plate at an inner peripheral portion; A lower clamp device that is provided in the outer peripheral portion of the casing tube and that can clamp the outer peripheral portion of the casing tube;
A hollow elevating frame connected to the base frame so as to be able to elevate and lower, a turning means provided on the elevating frame, and an upper clamp device provided on the turning means and capable of clamping an outer peripheral portion of the casing tube; In the shaft excavator provided with the above, the lower clamp device is a ring-shaped clamp ring capable of inserting the casing tube by rotatably connecting a plurality of clamp arms each having an arcuate inner peripheral surface by a connection shaft. A hydraulic cylinder capable of expanding and contracting the inner diameter of the clamp ring, and guide means for guiding the clamp ring on the receiving plate so that the clamp ring operates based on a preset center point during the operation of expanding and contracting the clamp ring. It is characterized by having.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a plan view of a lower clamping device mounted on an all-casing excavator as a shaft excavator according to a first embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the line II-II of FIG. 1, and FIG. FIG. 4 shows a sectional view taken along the line III-III, FIG. 4 shows a sectional view taken along the line IV-IV of FIG. 1, FIG. 5 shows a plan view of the base frame, and FIG.

The all casing excavator of the present embodiment
The structure is substantially the same as that described with reference to FIGS. 10 and 11, and a casing tube 10 as a tubular member is formed by connecting a large number of connecting tubes 10c to a first tube 10b having a cutter bit 10a at a lower portion by lock pins 10d. It is configured by being connected. A base frame 12 is installed on the ground G via a gantry 11, and a lower clamp device 14 having a clamp cylinder 13 is mounted on the base frame 12. An elevating frame 16 that can be moved up and down by an elevating cylinder 15 is connected to the base frame 12.
An upper clamp device 18 having a clamp cylinder 17 is mounted on the lifting frame 16, and the upper clamp device 18 is pivotably supported by a pivot device 20 having a pivot motor 19.

In the all-casing excavator thus constructed, the lower clamp device 14 is different from the conventional one. That is, as shown in FIGS. 1 to 4, in the lower clamp device 14 </ b> A of the present embodiment, the base frame 12 has the receiving plate 31 formed at the lower portion on the inner peripheral side. The clamp ring 32 has four ends, each of which has four arc arms 33a, 33b, 33c, and 33d having an arcuate inner peripheral surface.
The two connecting shafts 34a, 34b, 34c are rotatably connected, and the connecting shafts 35a, 35b of the clamp cylinder 13 are connected to ends of the clamp arms 33c, 33d. On the other hand, as shown in detail in FIG. 5, guide holes 36a, 36b and 36c as guide means for the clamp ring 32 are formed in the receiving plate 31 of the base frame 12. The lower portion of each of the connecting shafts 34a, 34b, 34c of the clamp ring 32 corresponds to the corresponding one of the guide holes 3.
The nut 38 engages with the nuts 6 a, 36 b, and 36 c and is screwed through the washer 37.

Each of the guide holes 36a, 36b, 36c
Guides the clamp ring 32 so as to operate with respect to the center point of the casing tube 10 when the clamp ring 32 expands and contracts, and has a long hole along a predetermined direction. The shape takes into account the axial center deviation of ten. The lower surface of the clamp ring 32 is attached to the receiving plate 31 of the base frame 12.
It is placed on top and is in sliding contact.

Therefore, as shown in FIG. 6, by extending the clamp cylinder 13, each clamp arm 33a,
The clamp of the casing tube 10 can be released by increasing the inner diameter of the clamp ring 32 composed of 33b, 33c, 33d. At this time, each clamp arm 3
Connection shafts 34a, 34 of 3a, 33b, 33c, 33d
Since the b and 34c move outward along the guide holes 36a, 36b and 36c, the clamp ring 32 expands outward with respect to the center point of the casing tube 10, and the clamp ring 32 and the outer peripheral surface of the casing tube 10 are clamped. The distance from the inner peripheral surface of the ring 32 is uniform at any position in the circumferential direction.

After the casing tube 10 moves upward, the clamp cylinder 13 is extended, and when the inside diameter of the clamp ring 32 is reduced to clamp the casing tube 10, the connecting shafts 34a, 34b,
34c moves inward along the guide holes 36a, 36b, 36c, so that the clamp ring 32 is reduced in diameter with respect to the center point of the casing tube 10, and the inner peripheral surface of the clamp ring 32 is a casing tube. The casing tube 10 can be properly in close contact with the outer peripheral surface of the casing 10 and can be securely clamped. As a result, the clamping force of the casing tube 10 by the lower clamp device 14A increases, and the casing tube does not fall off during the shaft excavation operation, and the shaft excavation operation using the large-diameter and heavy casing tube can be performed. .

FIGS. 7 to 9 show a lower clamping device according to a second embodiment of the present invention. FIG. 7 is a sectional view of a main part corresponding to FIG. 2, and FIG. 8 is a main part corresponding to FIG. FIG. 9 shows a cross section of a main part corresponding to FIG. Note that members having the same functions as those described in the above-described embodiment are denoted by the same reference numerals, and redundant description will be omitted.

As shown in FIGS. 7 to 9, in the lower clamping device 14B of this embodiment, the base frame 12
A receiving plate 31 is formed in the lower portion on the inner peripheral side of the clamp ring 32. The clamp ring 32 includes four clamp arms 33a and 33.
b, 33c, 33d have three connecting shafts 34a, 3
4b and 34c, and the ends of the clamp arms 33c and 33d are connected by the clamp cylinder 13. A guide hole 36 a is formed in the receiving plate 31 of the base frame 12, and the connection shaft 36 a is engaged with the guide hole 36 a and a nut 38 is screwed through a washer 37.

A plurality of guide projections 41 are suspended from the outer periphery of the clamp ring 32 (clamp arms 33a, 33b, 33c, 33d). On the other hand, the inner diameter hole 42 of the receiving plate 31 of the base frame 12 is
2 and the casing tube 10 are concentric circles,
The guide projection 41 is engaged with the end face of the inner diameter hole 42. That is, the guide projection 41 and the inner diameter hole 42 guide the clamp ring 32 to operate based on the center point of the casing tube 10 when the clamp ring 32 expands and contracts.

Therefore, by extending the clamp cylinder 13, the inner diameter of the clamp ring 32 can be increased and the clamp of the casing tube 10 can be released.
At this time, each of the clamp arms 33a, 33b, 33c,
Since the connecting shaft 34a of 33d moves outward along the guide hole 36a and the guide projection 41 comes into contact with the inner diameter hole 42, the clamp ring 32 is
And the distance between the outer peripheral surface of the casing tube 10 and the inner peripheral surface of the clamp ring 32 becomes uniform at any position in the circumferential direction.

After the casing tube 10 moves upward, the clamp cylinder 13 is extended, and when the inner diameter of the clamp ring 32 is reduced to clamp the casing tube 10, the clamp ring 32 is moved to the center of the casing tube 10. Since the diameter is reduced inward with respect to the point, the inner peripheral surface of the clamp ring 32 is properly adhered to the outer peripheral surface of the casing tube 10, and the casing tube 10 can be securely clamped.

In each of the above embodiments, the clamp ring 32 is connected to the four clamp arms 33a, 33b, 3
Although 3c and 33d are connected by connecting shafts 34a, 34b and 34c, the number of clamp arms is not limited to four, but may be two or five or more. Also, the first
By adding the configuration of the lower clamp device 14B of the second embodiment to the lower clamp device 14A of the embodiment, it is possible to further improve the reliability.

[0028]

As described in detail in the above embodiment, according to the clamp device of the first aspect of the present invention, a plurality of clamps whose inner peripheral surfaces are formed in an arc on the receiving plate on the inner peripheral portion of the base frame. A ring-shaped clamp ring is provided so that the tubular member can be inserted by rotatably connecting the arm with a connection shaft and a fluid cylinder. Since the guide means for guiding the clamp ring to operate on the receiving plate is provided, the clamp ring moves at a uniform distance at any position in the circumferential direction with respect to the tubular member, and the inner peripheral surface of the clamp ring has a tubular shape. The tubular member can be properly adhered to the outer peripheral surface of the member, and the tubular member can be reliably clamped, and the reliability of the device can be improved.

According to the second aspect of the present invention, since the guide means is constituted by the connecting shaft and the guide hole formed in the receiving plate and engaged with the connecting shaft, the clamp ring can be formed with a simple structure. The tubular member can be reliably clamped.

According to the third aspect of the present invention, the guide means is constituted by the guide projections suspended from the clamp arm and the inner diameter end face of the receiving plate with which the guide projections engage. Thus, the clamp ring can securely clamp the tubular member.

Further, according to the shaft excavator of the present invention, the casing tube, the base frame having the receiving plate on the inner peripheral portion, and the outer peripheral portion of the casing tube provided in the base frame can be clamped. A lower clamp device, an elevating frame connected to be able to ascend and descend above the base frame, and a turning means provided on the elevating frame,
An upper clamp device provided on the turning means and capable of clamping the outer peripheral portion of the casing tube, wherein the lower clamp device is mounted on a receiving plate on the inner peripheral portion of the base frame, and a plurality of clamp arms having an inner peripheral surface in an arc shape. Is connected by a connecting shaft and a fluid cylinder so as to be rotatable, and a ring-shaped clamp ring is provided through which the tubular member can be inserted. Since the guide means is provided on the receiving plate so that the ring operates, the clamp ring moves at a uniform distance at any position in the circumferential direction with the casing tube, and the inner peripheral surface of the clamp ring is The casing tube can be properly adhered to the outer peripheral surface, and the casing tube can be securely clamped. It is possible to improve the-reliability. As a result, the clamping force increases, and the casing tube can be excavated with a large-diameter and heavy-weight casing tube without falling off the casing tube during the shaft excavation operation.

[Brief description of the drawings]

FIG. 1 is a plan view of a lower clamp device mounted on an all-casing excavator as a shaft excavator according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a sectional view taken along the line III-III of FIG. 1;

FIG. 4 is a sectional view taken along line IV-IV of FIG. 1;

FIG. 5 is a plan view of a base frame.

FIG. 6 is a plan view illustrating an operation state of a lower lower clamp device.

FIG. 7 is a longitudinal sectional view of a main part of a lower clamp device according to a second embodiment of the present invention.

FIG. 8 is a longitudinal sectional view of a main part of the lower clamp device.

FIG. 9 is a longitudinal sectional view of a main part of the lower clamp device.

FIG. 10 is a front view illustrating an operation state of a general all-casing excavator.

FIG. 11 is a front view illustrating a state where a casing tube is removed by an all-casing excavator.

FIG. 12 is a plan view showing a conventional lower clamping device in an all-casing excavator.

[Explanation of symbols]

 Reference Signs List 10 casing tube 11 gantry 12 base frame 14A, 14B lower clamp device 16 elevating frame 18 upper clamp device 20 turning device 31 receiving plate 32 clamp ring 33a, 33b, 33c, 33d clamp arm 34a, 34b, 34c connecting shaft (guide means) 35a, 35b Connecting shaft 36a, 36b, 36c Guide hole (guide means) 41 Guide protrusion (guide means) 42 Inner diameter hole (guide means)

Claims (4)

[Claims] 1. A clamping device capable of clamping an outer peripheral portion of a tubular member, comprising: a hollow base frame mounted on a gantry and having a receiving plate on an inner peripheral portion; and a plurality of clamp arms having an inner peripheral surface in an arc shape. A ring-shaped clamp ring that allows the tubular member to be inserted by being rotatably connected by a connection shaft, a fluid cylinder that can expand and contract the inner diameter of the clamp ring, and a preset cylinder ring when the clamp ring is expanded and contracted. And a guide means for guiding the clamp ring on the receiving plate so that the clamp ring operates on the basis of the center point. 2. The clamping device according to claim 1, wherein
The said guide means has the said connection shaft and the guide hole formed in the said receiving plate and the said connection shaft engages, The clamp apparatus characterized by the above-mentioned. 3. The clamping device according to claim 1, wherein
The said guide means has the guide protrusion suspended from the said clamp arm, and the inner diameter end surface of the said receiving plate with which this guide protrusion engages, The clamp apparatus characterized by the above-mentioned. 4. A casing tube having a cutter at a lower portion, a hollow base frame mounted on a gantry and having a receiving plate at an inner peripheral portion, and an outer peripheral portion of the casing tube provided in the base frame. A lower clamp device capable of being clamped, a hollow elevating frame connected to the base frame so as to be able to elevate and lower, a turning means provided on the elevating frame, and an outer peripheral portion of the casing tube provided on the turning means An upper clamp device capable of clamping the casing tube, wherein the lower clamp device penetrates the casing tube by rotatably connecting a plurality of clamp arms having an arcuate inner peripheral surface by a connection shaft. A clamp ring having a ring shape, a hydraulic cylinder capable of expanding and contracting the inner diameter of the clamp ring, And a guide means for guiding the clamp ring on the receiving plate such that the clamp ring operates based on a preset center point at the time of enlarging / reducing operation of the shaft.