JPS61158592A - Bottom expanding excavator for placing pile pit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a bottom-expanding excavator for cast-in-place pile holes for widening the bottom of the cast-in-place pile hole into a tapered shape.

(Prior art) In order to improve the earthquake resistance of cast-in-place piles, as shown in Fig. 7, the bottom of the cast-in-place pile hole 1 is widened into a tapered bottom part 2.
The diameter of the bottom of the cast-in-place pile is expanded.

Conventionally, a bottom-expanding excavator 3 for forming the bottom-expanding portion 2 of such a cast-in-place pile hole 1 has a link arm 5 that supports three rotary pits 4, as shown in FIGS. 8 and 9, for example.
In some cases, the revolution radius of the rotating bit 4 is gradually increased by gradually increasing the cutting radius to gradually increase the cutting radius to form the expanded bottom part 2, and in other cases, the cutting blade is expanded to match the hole shape to form the inner surface. It is known that it finishes.

(Problems to be Solved by the Invention) However, such a bottom-expanding excavator has the drawback that the bottom-expanding portion 2 is clogged with earth and sand excavated by the rotary pits 4 or cutting blades, making it difficult to excavate.

An object of the present invention is to provide a bottom-expanding excavator for cast-in-place pile holes that can easily perform bottom-expanding excavation and discharge of excavated soil at the time.

(Means for Solving the Problems) The structure of the present invention for achieving the above object will be explained with reference to FIGS. 1 to 6 corresponding to the embodiments. A bottom-expanding excavator for cast-in-place pile holes, which is equipped with a cylindrical frame 8 on which posture guides 9 and 11 are radially protruded along the direction, and a bottom-expanding excavation mechanism 22 provided at the bottom of the cylindrical frame 8. 6, the bottom-expanding excavation mechanism 22 includes a rotating frame 25 rotatably supported horizontally at the lower part of the cylindrical frame 8, a rotating means 26 for forcibly rotating the rotating frame 25, and a rotating frame 25. a vertically split excavation tube 29 whose upper portion is pivoted to open and close in a downward tapered manner; and the cylindrical frame 8.
and a diameter expanding means 3° which is suspended and supported within the vertically split excavation tube 29 and expands the diameter of the vertically split excavation tube 29 in a tapered shape.
This is characterized in that digging blades 32 and 34 are provided in each of the slit 31 along the longitudinal direction of the side plate 29A and the slit 33 facing in the radial direction of the bottom plate 29B.

(Function) Such a bottom-expanding excavator 6 expands the diameter of the vertically divided excavation tube 29 into a tapered shape using the diameter expanding means 30 while maintaining the posture of the cylindrical frame 8 using the posture guides 9 and 11. When the rotating means 26 rotates the excavation blades 32 and 34, the excavated soil is taken into the excavation cylinder 29 through each slit 31 and 33, and the expanded bottom part 2 is easily formed at the bottom of the excavation hole 1. is formed. The earth and sand taken into the excavation tube 29 are
By pulling up the bottom-expanding excavator 6, earth can be easily discharged onto the ground.

(Example) Examples of the present invention will be described in detail below with reference to FIGS. 1 to 6. As shown in the figure, the bottom-expanding excavator 6 for cast-in-place pile holes of this embodiment includes a vertically oriented cylindrical frame 8 that is suspended and supported by a crane via a tread 7, and the middle part of the cylindrical frame 8 is A fixed posture guide 9 is provided on the outer periphery of the
They are radially protruded through brackets 10 at intervals of 90' along the longitudinal direction of the cylindrical frame 8. Furthermore, movable posture guides 11 are provided on the outer periphery of both upper and lower ends of the cylindrical frame 8 to protrude radially at intervals of 90° along the longitudinal direction of the cylindrical frame 8 . Hydraulic guide drive mechanisms 12 are interposed between these movable posture guides 11 and the cylindrical frame 8, respectively, for varying the protrusion length of these posture guides 11. These hydraulic guide drive mechanisms 12 have a fixed stopper 13 that is intermittently protruded from the outer periphery of the cylindrical frame 8, and are fitted to the outer periphery of the cylindrical frame 8 and hit the stoppers 13, thereby allowing the hydraulic guide drive mechanism 12 to move within a vertical movement range. a pair of upper and lower movable stop rings 15.16 which are restricted and prevented from rotating by fitting the recess 14 into the stopper 13; and a guide support frame 17 supported by these movable stop rings 15.16. , a pair of upper and lower guides 11i18 supported laterally at the tip of the guide support frame 17, and upper and lower guides 11i18 that protrude inward from the inner surface of the posture guide 11 and are slidably fitted into each guide tube 18. A pair of guide rods 19 and a guide support frame 1
7 and a guide drive hydraulic cylinder 20 pivotally connected between the position guide 11 and the posture guide 11. A detent protrusion 21 is provided on the surface of each posture guide 11 in a direction along its longitudinal direction.

A bottom-expanding excavation mechanism 22 is provided at the bottom of the cylindrical frame 8. This bottom-expanding excavation mechanism 22 includes a support disk 23 fixed to the lower part of a cylindrical frame 8, a rotating frame 25 horizontally rotatably supported on the outer periphery of the support disk 23 via a bearing 24, and a rotating frame 25 that is rotatable horizontally. A vertically split type excavator whose upper part is pivoted by a pivot shaft 28 to a rotating means 26 that forcibly rotates the frame 25 and a bracket 27 that projects diagonally downward from the outer periphery of the rotating frame 25, and which opens and closes downward. From the cylinder 29 and the cylinder frame 8, this vertically divided excavation cylinder 2 is removed.
9 and a diameter expanding means 30 for expanding the diameter of the vertically divided excavation cylinder 29 in a tapered shape. The rotating means 26 includes a motor 26A installed on the bottom plate 8A in the cylindrical frame 8, and a motor 2 that passes through the bottom plate 8A.
A gear 26B fixed to the output shaft of 6A, and this gear 26
It is composed of a gear 26G that meshes with the gear 26G, and an internal gear 26D that is carved on the inner periphery of the rotating frame 25 and meshes with the gear 26G. In this embodiment, the vertically split excavation cylinder 29 has a two-part structure, and the side plate 29A is provided with slits 31 along the longitudinal direction, and each slit 3
A digging blade 32 is attached to one side edge of each. A slit 33 is provided in the radial direction in the bottom plate 29B of the vertically divided excavation tube 29, and an excavation blade 34 is attached to one edge of each slit 33, respectively. Diameter expansion means 3
0 is a guide column 30A hanging from the support disk 23;
A conical three-dimensional cam 30B is fitted to the lower part of this guide column 30A so as to be slidable up and down, and a pair of cam lifting hydraulic cylinders 300 that suspend this three-dimensional cam 30B below the support disk 23 and raise and lower it. , a roller 30E rotatably supported by a bracket 30D protruding from the inner surface of both sides of the split surface 29C of the vertically split excavation tube 29 and in contact with the conical cam surface of the three-dimensional cam 30B; It is composed of springs 30F that bias both sides of the cut surface 29G of the split excavation cylinder 29 in a direction to close them.

Inside the cylindrical frame 8 is a guide drive hydraulic cylinder 20.
A hydraulic unit 35 that drives a cam lifting hydraulic cylinder 30G and a cam lifting hydraulic cylinder 30G is incorporated.

Such a bottom-expanding excavator 6 is lowered from a crane to a cast-in-place pile hole 1 in the ground with a rope 7, and is lowered into a vertically split excavation cylinder 2.
With the bottom plate 29B of 9 reaching the bottom of the pile hole 1, each posture guide 11 is pushed outward by the action of the guide drive hydraulic cylinder 20 of the hydraulic guide drive mechanism 12, and is inserted into the inner surface of the cast-in-place pile hole 1. The cylindrical frame 8 is stopped from rotating by abutting against it and causing the anti-rotation protrusion 21 to bite into the soil. In this state, the motor 26A of the rotation means 26 is driven to forcibly rotate the vertically divided excavation cylinder 29 via the rotation frame 25. At this time, a moment in the opposite direction to the rotation is applied to the cylindrical frame 8, but since the protrusions of the posture guide 11 are biting into the soil, only the divided excavation cylinder 29 is rotated.

Further, when the cam elevating hydraulic cylinder 30G of the diameter expanding means 3o is gradually contracted and the three-dimensional cam 30B is gradually raised, the roller 30E on the side of the vertically split excavation cylinder 29 comes into contact with the conical cam surface of the three-dimensional cam 30B. Therefore, as the three-dimensional cam 30B rises, the vertically split excavation tube 29 opens downward in a tapered shape at the split surface 29G.

Therefore, as the tapered excavation pipe 29 rotates, the excavation blades 32 and 34 can easily excavate the tapered bottom portion 2 that widens toward the end. The earth and sand excavated by the excavation blades 32.34 enters the excavation cylinder 29 through the slits 31.33. Soil can be removed by extending the cam elevating hydraulic cylinder 30C, lowering the three-dimensional cam 30B, and raising the expanded bottom excavation 16 with the excavation tube 29 closed by the force of the spring 30F. Depending on the method of excavation, it is necessary to lower the excavation tube 29 while rotating it, but in this case, even when the posture guide 11 is protruded by the hydraulic guide drive mechanism 12, the cylindrical frame 8 is moved vertically by the movable stop ring 15. 16
By loosening the cable 7, the cylindrical frame 8, ie, the excavation cylinder 29, can be lowered until the stopper 13 hits the movable stop ring 16.

Conversely, by winding up the cable 7, the stopper 1
3 hits the movable stop ring 15.
That is, the excavation cylinder 29 can be raised.

(Effects of the Invention) As explained above, the bottom-expanding excavator for cast-in-place pile holes according to the present invention uses a vertically split type excavation tube, and the excavation blade is provided in the slit provided in the longitudinal direction of the side plate of this excavation tube. In addition, an excavation blade is provided in the radial slit in the bottom plate of this excavation tube, and the excavation tube is forcibly rotated with the split surface tapered open, so that the excavated earth and sand can be transferred from the slit into the excavation tube. This has the advantage that excavated soil does not interfere with excavation. In addition, earth removal work can be easily performed by closing the excavation tube and lifting the entire excavation tube. Therefore, according to the present invention, it is possible to easily and efficiently form the bottom enlarged portion of the excavation hole.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view of a main part of an embodiment of a bottom-breaking excavator according to the present invention, Fig. 2 is an enlarged longitudinal cross-sectional view of the hydraulic guide drive mechanism portion of the posture guide shown in Fig. Main part cross-sectional view showing the relationship between the stopper and stop ring of the mechanism, No. 4
The figure is an enlarged sectional view of the excavation means on the side plate of the excavation tube used in this example, FIG. 5 is a cross-sectional view of the excavation tube, and FIG. 6 is an enlarged sectional view of the excavation means on the bottom plate of the excavation tube. FIG. 7 is a longitudinal cross-sectional view of the bottom enlarged portion of the excavation hole, and FIGS. 8 and 9 are a side view and a bottom view of an example of a conventional bottom enlargement excavator. 1...Pile hole cast in place, 2...Expanded bottom part,
6... Bottom expanding excavator, 8... Cylindrical frame, 9, 11... Posture guide, 12...-
・Hydraulic guide drive mechanism, 22... Expanding sugar agent mechanism, 23... Support disk, 25... Rotating frame, 26... Rotating means, 29・・・・・・
・Vertical split excavation tube, 30...Diameter expansion means, 3
1...Slit, 32...-Drilling blade, 3
3...Slit, 34...Drilling blade, 3
5... Hydraulic unit. Patent applicant Masago Kogyo Co., Ltd. Figure 8 Figure 7

Claims (1)

[Claims] A bottom-expanding excavator for cast-in-place pile holes, which includes a cylindrical frame in which posture guides radially protrude along the longitudinal direction from the outer periphery, and a bottom-expanding excavation mechanism provided at the bottom of the cylindrical frame, The bottom-expanding excavation mechanism includes a rotating frame horizontally and rotatably supported by the lower part of the cylindrical frame, a rotating means for forcibly rotating the rotating frame, and an upper part of the rotating frame is pivotably supported so as to be downwardly oriented. a vertically split excavation tube that opens and closes in a tapered shape; and a diameter expanding means that is suspended from the cylindrical body frame into the vertically divided excavation tube and expands the diameter of the vertically divided excavation tube in a tapered shape. and a cast-in-place pile, characterized in that the vertically divided excavation cylinder has excavation blades provided in each of a slit along the longitudinal direction of the side plate and a slit oriented in the radial direction of the bottom plate. Bottom-expanding drilling machine for holes.