JP2023174192A - Existing pile cutting device - Google Patents

Abstract

To provide an existing pile cutting device for cutting a part of an existing pile embedded in the ground, and pulling out the part.SOLUTION: A cutting device 38 which excavates a pull-out hole 16 by rotating a cylindrical casing 12 with an excavator 14 connected to a heavy machine 11, bores a projection hole 30 in the casing 12 in a cut place of an existing pile 19 embedded in a ground 10, and has a cutting bit 29 facing the projection hole 30 is provided on an outer periphery of the existing pile 19, a drive part 39 for advancing/retracting the cutting bit 29 to the inner part from the outer part of the projection hole 30 is provided in the casing 12 mounted with the cutting device 38, and the casing 12 is rotated while pressing the cutting bit 29 against the existing pile 19 from the projection hole 30, and the existing pile 19 is cut.SELECTED DRAWING: Figure 1

Description

The present invention relates to an existing pile cutting device for cutting and pulling out a part of an existing pile buried underground.

In order to construct a new structure, it has been assumed that all existing piles that are a nuisance and are buried underground must be pulled out from their roots.
In order to pull out such existing piles, a construction method as shown in FIG. 9(a) (cited document 1) and a construction method as shown in FIG. 9(b) (cited document 2) were known.

In the construction method shown in FIG. 9(a) (cited document 1), an excavator 14 is attached to a guide column 13 of a heavy machine 11 so as to be movable up and down, and the cylindrical casing 12 is rotated by the excavator 14. A pull-out hole 16 is excavated around the existing pile 19 using the excavating blade at the tip of the casing 12, and water or the like is injected to make the area around the existing pile 19 muddy soil 18, and the wire rope is tied to the tip of the casing 12 and introduced. 15 is wound around the tip of the existing pile 19, the casing 12 is pulled out first, and then the wire rope 15 is pulled up and the existing pile 19 is pulled out.

In the construction method shown in FIG. 9(b) (cited document 2), an excavator 14 is attached to a guide column 13 of a heavy machine 11 so as to be movable up and down, and the casing 12 is rotated by the excavator 14, and the lower end of the casing 12 is rotated by the excavator 14. The procedure is the same as in Cited Document 1 until the area around the existing pile 19 is turned into mud 18 by injecting water while drilling a pull-out hole 16 around the existing pile 19 with a cutting blade. In the case of cited document 2, when the casing 12 reaches the tip of the existing pile 19, the chuck claws 17 are protruded inward from the tip of the casing 12 so as to surround the tip of the existing pile 19, and the casing 12 is pulled out. This method also involves pulling out the existing piles 19 at the same time.

JP2019-206814A Japanese Patent Application Publication No. 2010-101109

According to the construction methods of Patent Documents 1 and 2, all of the buried existing piles 19 are pulled out from the roots, and are effective when the existing piles 19 are relatively short.
However, if the existing pile 19 is long, the casing 12 must be connected to a length that exceeds the existing pile 19 in order to pull it out all at once, making it difficult to excavate the extraction hole 16 and pull out the existing pile 19. Master.
In addition, when the existing piles 19 are long, there are cases where only a part of the upper end needs to be cut and removed in order to construct a new structure without having to pull out all the existing piles 19 from the root, or when the long existing piles 19 are When cutting and pulling out the pile in multiple stages, it is desirable to cut the existing pile 19 to a predetermined length and pull it out in sequence.

An object of the present invention is to provide an existing pile cutting device for cutting and pulling out a part of an existing pile buried underground.

The existing pile cutting device according to the present invention includes:
The existing pile 19 is removed by rotating a cylindrical casing 12 to excavate a pull-out hole 16 on the outer periphery of the existing pile 19 buried in the ground 10 using an excavator 14 connected to a heavy machine 11. In the cutting device of
A protrusion hole 30 is bored in the casing 12 at the cutting point of the existing pile 19, a cutting device 38 equipped with a cutting bit 29 is provided facing the protrusion hole 30, and the casing 12 is equipped with the cutting device 38. A drive unit 39 is provided for driving the cutting bit 29 forward and backward from the outside of the protruding hole 30 to the inside thereof, and the casing 12 is rotated while pressing the cutting bit 29 from the protruding hole 30 to the existing pile 19. The present invention is characterized in that the existing pile 19 is cut by cutting the existing pile 19.

The cutting device 38 includes a cutting arm 27 having the cutting bit 29 attached to one end thereof, a guide frame 28 for guiding the cutting arm 27 to the protruding hole 30, and a bendable member at the other end of the cutting arm 27. It is equipped with a connected and slidable crank rod 26.

The cutting arm 27 has an arcuate shape, the guide frame 28 is an arcuate frame 28a, and the cutting bit 29 at one end of the cutting arm 27 is guided by the arcuate frame 28a to advance and retreat into the protrusion hole 30. It is characterized by being configured as follows.

The drive unit 39 includes a hydraulic jack 20 and a slidable push rod 23 whose one end is connected to the piston rod 22 of the hydraulic jack 20 and whose other end is connected to the crank rod 26. It is characterized by

The casing 12 has a top casing 12a attached to the excavator 14 and located on the ground, a tip casing 12c at the cutting position of the existing pile 19, and an intermediate casing 12b connecting these. The tip casing 12c is provided with the cutting device 38 and the drive unit 39, the top casing 12a is provided with a stroke instruction cylinder 21 that controls the hydraulic jack 20, and the hydraulic jack 20 and stroke instruction cylinder 21 are connected to each other with oil. It is characterized by being connected by a feed pipe.

The drive unit 39 includes a motor 40, a threaded rod 44 connected to the rotating shaft of the motor 40, a movable nut 45 that converts the rotation of the threaded rod 44 into reciprocating motion, and one end connected to the movable nut 45. and a connecting arm 46 whose other end is connected to the crank rod 26.

The cutting device 38 is provided with a slider 47 that slides within a guide frame 50 provided in the longitudinal direction of the casing 12 on the outside of the casing 12 including the protruding hole 30, and a slanted groove 48 formed in the slider 47 , a pin 49 provided on the cutting bit 29 is engaged, the slider 47 is connected to the driving part 39, and the cutting bit 29 is provided so as to be able to move forward and backward into the protrusion hole 30 by reciprocating the slider 47; It is characterized by

The cutting device 38 is characterized in that a plurality of cutting devices 38 are provided on the outer periphery of the casing 12 with substantially the same central angle.

According to the invention described in claim 1,
An existing pile cutting device that rotates a cylindrical casing to excavate a pull-out hole on the outer periphery of an existing pile buried in the ground using an excavator connected to heavy equipment, and pulls out and removes the existing pile,
A protruding hole is drilled in the casing at the cutting point of the existing pile, a cutting device equipped with a cutting bit is provided facing the protruding hole, and the cutting bit is inserted into the casing to which the cutting device is attached. A drive unit that moves inward from the outside of the hole is provided, and the casing is rotated while pressing the cutting bit from the protruding hole to the existing pile to cut the existing pile. have an effect.
(1) If the existing piles are long, it is possible to cut and remove only the part that gets in the way of the top end, without having to pull out all the existing piles from the base in order to construct a new structure.
(2) Even long existing piles can be cut to a predetermined length and pulled out one after another, resulting in excellent pulling workability.

According to the invention as claimed in claim 2,
The cutting device includes a cutting arm having the cutting bit attached to one end thereof, a guide frame for guiding the cutting arm to the protrusion hole, and a slidable member that is bendably connected to the other end of the cutting arm. Since the cutting bit is provided with a crank rod, the cutting bit can be moved forward and backward from the protruding hole in a narrow space outside the casing.

According to the invention recited in claim 3,
The cutting arm has an arcuate shape, the guide frame is an arcuate frame, and the cutting bit at one end of the cutting arm is guided by the arcuate frame to move forward and backward into the protruding hole. The reciprocating motion of the arm on the outer periphery of the casing can be converted into the forward and backward motion of the cutting bit into the protruding hole.

According to the invention described in claim 4,
The drive unit includes a hydraulic jack and a slidable push rod whose one end is connected to the piston rod of the hydraulic jack and the other end is connected to the crank rod, so that the reciprocating motion of the hydraulic jack is can be smoothly transmitted to the cutting bit.

According to the invention described in claim 5,
The casing includes a top casing attached to the excavator and located on the ground, a tip casing at a cutting position of the existing pile, and an intermediate casing connecting these, and the tip casing has a top casing located on the ground. The device and the drive section are provided, a stroke instruction cylinder for controlling the hydraulic jack is provided in the top casing, and the hydraulic jack and stroke instruction cylinder are connected by an oil pipe, so that the cutter is driven underground. The movement of the device and the drive unit can be visually confirmed with a stroke indicating cylinder on the ground.

According to the invention described in claim 6,
The drive unit includes a motor, a threaded rod connected to a rotating shaft of the motor, a moving nut that converts the rotation of the threaded rod into reciprocating motion, one end of which is connected to the moving nut, and the other end of which is connected to the moving nut. Since it consists of a connecting arm connected to the crank rod, the stroke of the cutting bit, etc. of the cutting device can be controlled by the rotation of the motor.

According to the invention described in claim 7,
The cutting device is provided with a slider that slides within a guide frame provided in the longitudinal direction of the casing on the outside of the casing including the protruding hole, and a pin provided on the cutting bit is inserted into an inclined groove formed in the slider. The slider is connected to the driving part, and the cutting bit is moved forward and backward into the protruding hole by the reciprocating movement of the slider, so that the cutting bit is pressed perpendicularly to the surface of the existing pile to cut it. can.

According to the invention described in claim 8,
A plurality of cutting devices are provided around the outer periphery of the casing with substantially the same center angle, so even if the existing pile is deviated from the center of the casing, the plurality of cutting bits are pressed approximately equally, and the existing pile is aligned with the center of the casing. Existing piles can be cut efficiently by adjusting the position.

1 is a front view showing a first embodiment of an existing pile cutting device according to the present invention. (a) is a side view of the tip casing 12c in FIG. 1, (b) is a front view of the tip casing 12c in FIG. 1, and (c) is a bottom view of the tip casing 12c in FIG. 1. FIG. 2 is a perspective view of the tip casing 12c in FIG. 1. FIG. (a) is a cross-sectional view of the existing pile 19 cut by the cutting device 38 of the present invention, and (b) is a bottom view of (a). 3A and 3B are explanatory diagrams of a cutting bit 29 and a bit holder 35 used in an existing pile cutting device 38 according to the present invention, in which (a) is a side view of the cutting bit 29, (b) is a plan view of the cutting bit 29, and (c) ) is a front view of the cutting bit 29, and (d) is a perspective view of the bit holder 35. It is a perspective view of the cut surface 36 which cut the existing pile 19 with the existing pile cutting device 38 of this invention. Embodiment 2 shows a second embodiment of the existing pile cutting device 38 of the present invention, in which (a) is an overall front view, and (b) is an enlarged front view of the main part of (a). It is a sectional view of Example 3 of cutting device 38 of an existing pile of the present invention. (a) is an explanatory diagram described in cited document 1, and (b) is an explanatory diagram described in cited document 2.

The existing pile cutting device according to the present invention includes:
The existing pile 19 is removed by rotating a cylindrical casing 12 to excavate a pull-out hole 16 on the outer periphery of the existing pile 19 buried in the ground 10 using an excavator 14 connected to a heavy machine 11. In the cutting device of
A protrusion hole 30 is bored in the casing 12 at the cutting point of the existing pile 19, a cutting device 38 equipped with a cutting bit 29 is provided facing the protrusion hole 30, and the casing 12 is equipped with the cutting device 38. A drive unit 39 is provided for driving the cutting bit 29 forward and backward from the outside of the protruding hole 30 to the inside thereof, and the casing 12 is rotated while pressing the cutting bit 29 from the protruding hole 30 to the existing pile 19. Then, the existing pile 19 is cut.

The cutting device 38 includes a cutting arm 27 having the cutting bit 29 attached to one end thereof, a guide frame 28 for guiding the cutting arm 27 to the protruding hole 30, and a bendable member at the other end of the cutting arm 27. The crank rod 26 is connected to a slidable crank rod 26.

The cutting arm 27 has an arcuate shape, the guide frame 28 is an arcuate frame 28a, and the cutting bit 29 at one end of the cutting arm 27 is guided by the arcuate frame 28a to advance and retreat into the protrusion hole 30. Configure it as follows.

The drive unit 39 includes a hydraulic jack 20 and a slidable push rod 23 whose one end is connected to the piston rod 22 of the hydraulic jack 20 and whose other end is connected to the crank rod 26. There is.

The casing 12 has a top casing 12a attached to the excavator 14 and located on the ground, a tip casing 12c at the cutting position of the existing pile 19, and an intermediate casing 12b connecting these. The tip casing 12c is provided with the cutting device 38 and the drive unit 39, the top casing 12a is provided with a stroke instruction cylinder 21 that controls the hydraulic jack 20, and the hydraulic jack 20 and stroke instruction cylinder 21 are connected to each other with oil. Connect with feed pipe.

The drive unit 39 includes a motor 40, a threaded rod 44 connected to the rotating shaft of the motor 40, a movable nut 45 that converts the rotation of the threaded rod 44 into reciprocating motion, and one end connected to the movable nut 45. and a connecting arm 46 whose other end is connected to the crank rod 26.

The cutting device 38 is provided with a slider 47 that slides within a guide frame 50 provided in the longitudinal direction of the casing 12 on the outside of the casing 12 including the protruding hole 30, and a slanted groove 48 formed in the slider 47 , a pin 49 provided on the cutting bit 29 is engaged to connect the slider 47 to the driving part 39, and the cutting bit 29 is provided in the protrusion hole 30 so as to be freely movable forward and backward by the reciprocating movement of the slider 47.

A plurality of the cutting devices 38 are provided on the outer periphery of the casing 12 with substantially the same central angle.

Embodiment 1 A first embodiment of an existing pile cutting device according to the present invention will be described based on FIGS. 1 to 3.
Note that the same parts as in the conventional example are given the same reference numerals.
In FIG. 1, 14 is an excavator supported by the guide column 13 of the heavy equipment 11 similar to that in FIG. A casing 12 for excavating a pullout hole 16 around an existing pile 19 buried in the ground 10 is rotatably attached to this excavator 14. A plurality of casings 12 are connected according to the depth of the extraction hole 16, and are composed of a top casing 12a at the upper end, a tip casing 12c at the lower end, and an intermediate casing 12b therebetween.

The tip casing 12c is provided at its tip with a drilling blade 31 for digging the extraction hole 16, and is also provided with a nozzle (not shown) for spraying filling liquid or water.
The tip casing 12c is also provided with a cutting device 38 at its tip, and a drive section 39 for driving the cutting device 38 is provided above the cutting device 38. In the first embodiment, this drive unit 39 is mainly configured with the hydraulic jack 20. A stroke instruction cylinder 21 that controls the hydraulic jack 20 of the drive section 39 is attached to the top casing 12a, and the oil ports between the stroke instruction cylinder 21 and the hydraulic jack 20 are A port, B port, and C port. connected by ports. Specifically, an A port oil feed pipe is connected to the pressure oil port 52 of the stroke instruction cylinder 21, and a C port is connected between the pressure oil port 53 of the stroke instruction cylinder 21 and the pressure oil port 54 of the hydraulic jack 20. is connected, and the B port is connected to the pressure oil port 55 of the hydraulic jack 20. 51 is a sequence valve.
As shown in FIG. 2(b), the cutting device 38 and the drive unit 39 are protected by a cover 37 to protect them from damage, mud, etc. during excavation of the extraction hole 16.

Details of the cutting device 38 and the drive section 39 will be explained with reference to FIGS. 2 and 3.
The hydraulic jack 20 of the drive section 39 is fixedly attached to the upper end of the tip casing 12c. The piston rod 22 of the hydraulic jack 20 is connected to a push rod 23 that moves forward and backward within a rod guide 24 fixedly attached to the side surface of the tip casing 12c.
A guide frame 28 is fixedly attached to the cutting device 38 at the lower end of the tip casing 12c. The guide frame 28 consists of an arcuate frame 28a and a straight frame 28b. The arcuate frame 28a has an arcuate groove 32a on which the pin 33a slides, and the straight frame 28b has a straight line on which the pin 33b slides. A groove 32b is formed.
One end of the crank rod 26 is loosely fitted between the two frame frames 25 attached to the tip of the push rod 23, and the two frames 25 are connected to each other by the pin 33b so as to be flexible. Further, the other end of the crank rod 26 is loosely fitted into a groove 57 at one end of the arc-shaped cutting arm 27 and is connected to the crank rod 26 so as to be bendable by the pin 33a.

A cutting bit 29 is attached to the other end of the cutting arm 27, and the cutting bit 29 is provided so as to be freely retractable from a protruding hole 30 formed in the tip casing 12c.
As shown in FIGS. 4 and 5, this cutting bit 29 has a carbide tip 34 embedded in the tip of a pedestal 56, and this pedestal 56 is removably assembled into a bit holder 35 with a screw or the like, and the cutting arm 27 Insert and secure it into the tip of the The angle of the tip of the carbide tip 34 is determined by the material of the existing pile 19 to be cut. For example, if the existing pile 19 is a single metal member such as a steel pipe, one with an acute tip angle is used. In the case of a mixture of reinforcing bars such as PC piles and concrete, chipping of the carbide tip 34 can be reduced by making the tip angle slightly obtuse. The existing pile 19 is cut at an angle X of 10 to 40 degrees with respect to the vertical line a of the existing pile 19, as shown in FIG. 4(a). This angle X is adjusted by the guide groove angle of the arcuate frame 28a. The rotational speed of the tip casing 12c when cutting the existing pile 19 is set depending on the material of the existing pile 19 and the torque when drilling the extraction hole 16, but is approximately 5 to 20 rpm/min.

In the first embodiment, the cutting device 38 is provided at two locations on the outside of the tip casing 12c with the cutting bit 29 directed toward the center of the existing pile 19 at an interval of 180 degrees. However, this cutting device 38 may be provided at three or more locations around the existing pile 19 at equal intervals, or this cutting device 38 may be provided at one location.

The operation of cutting with the above configuration will be explained.
A heavy machine 11 is installed near an existing pile 19 to be cut and pulled out, and a pull-out hole 16 is excavated with an excavator blade 31 while a casing 12 suspended from a guide column 13 is rotated by an excavator 14.
The pull-out hole 16 is excavated to the cutting position of the existing pile 19 while sequentially connecting a plurality of intermediate casings 12b between the top casing 12a and the tip casing 12c according to the depth of the pull-out hole 16.
At this time, the stroke instruction cylinder 21 attached to the top casing 12a is placed in a position exposed above the ground.

When the cutting device 38 provided on the tip casing 12c reaches the cutting position of the existing pile 19, pressure oil is sent from the A port to the pressure oil port 52 of the stroke instruction cylinder 21 on the ground, and then through the pressure oil port 53 of the stroke instruction cylinder 21. Pressure oil is sent to the pressure oil port 54 of the hydraulic jack 20, the piston rod 22 is made to protrude, the push rod 23, the crank rod 26, and the cutting arm 27 are pushed out, and the two cutting bits 29 are made to protrude from the protrusion hole 30. At this time, since the existing pile 19 is not necessarily located at the center of the tip casing 12c, the casing 12 is rotated by the excavator 14 so that the cutting bits 29 at two locations contact the existing pile 19 with approximately the same load. At the same time, pressure oil is sent from two stroke instruction cylinders 21 to two hydraulic jacks 20, and the pressure is adjusted by two sequence valves 51.
After adjusting so that approximately the same load is applied to the two cutting bits 29, the two cutting bits 29 are rotated as shown in FIG. 4(a) while rotating the casing 12 at 5 to 20 rpm/min in the direction shown in FIG. 4(b). Cut the existing pile 19 by extruding it as shown in the figure. In FIG. 4(a), one cutting bit 29 has reached the existing pile 19, and the other cutting bit 29 has not reached the existing pile 19, but this description is used to explain the movement of the cutting bit 29. However, when cutting the existing pile 19, both cutting bits 29 come into contact with the same force. The same applies to other drawings.
Due to the rotation of the casing 12, the existing pile 19 is cut. As the cutaway diagram is shown in FIG. 6, the cut surface 36 shows that the concrete and reinforcing bars that constitute the existing pile 19 have been cut.

The cut existing pile 19 is pulled out from the pull-out hole 16 and removed.
The extraction is performed by the method shown in FIG. 9(a) (cited document 1), the method shown in FIG. 9(b) (cited document 2), or other known methods.

Embodiment 2 of the present invention is an example in which the drive unit 39 is configured with a motor 40 in FIGS. 7(a) and 7(b). The motor 40 is fixedly attached to any one of the casings 12, including the top casing 12a, the intermediate casing 12b, and the tip casing 12c. The rotating shaft of this motor 40 is connected to a threaded rod 44 at the tip casing 12c with an extension rod 41 and a fixed flange 42 interposed as appropriate. A movable nut 45 that moves forward and backward by forward and reverse rotation of the threaded rod 44 is screwed onto this threaded rod 44, and a connecting arm 46 is connected to this moving nut 45. The crank rod 26 is bendably connected by a pin 33b. The structure of the cutting device 38 beyond the crank rod 26 is the same as in the first embodiment.

In such a configuration, when the motor 40 rotates forward, the connecting arm 46 advances together with the movable nut 45 that is screwed onto the threaded rod 44, and the cutting bit 29 of the cutting device 38 projects from the protruding hole 30 of the tip casing 12c and cuts into the existing pile. Cut 19. After cutting the existing pile 19, the cutting bit 29 of the cutting device 38 exits from the tip casing 12c by the reverse rotation of the motor 40.

Embodiment 3 of the present invention, as shown in FIG. 8, is configured such that the cutting device 38 moves forward and backward relative to the existing pile 19 at right angles to the axial direction of the existing pile 19, so that the protrusion of the tip casing 12c A cutting bit 29 is arranged outside the hole 30 so as to move forward and backward at right angles to the axial direction of the existing pile 19. Two pins 49 are fixed to the base 56 of the cutting bit 29, and the pins 49 are fitted into the inclined grooves 48 of the slider 47. The slider 47 is covered with a guide frame 50 so as to slide on the outer surface of the tip casing 12c. A push rod 23 is connected to the slider 47, and the push rod 23 is connected to the piston rod 22 of the hydraulic jack 20.

In such a configuration, when the push rod 23 is reciprocated by the hydraulic jack 20, the slider 47 connected to the push rod 23 is also reciprocated. Then, since the pin 49 is fitted into the inclined groove 48 of the slider 47, the cutting bit 29 moves forward and backward toward the existing pile 19 from the protrusion hole 30 of the tip casing 12c. As the cutting bit 29 advances and the casing 12 rotates, the existing pile 19 is cut by the cutting bit 29. The cut existing pile 19 is pulled out and removed by the method shown in FIG. 9(a), FIG. 9(b), or by other methods.
When the slider 47 is pushed out, the cutting bit 29 is pulled out from the projection hole 30.

10... Ground, 11... Heavy equipment, 12... Casing, 13... Guide column, 14... Excavator, 15... Wire rope, 16... Pulling hole, 17... Chuck claw, 18... Mud, 19... Existing pile, 20... Hydraulic jack , 21... Stroke instruction cylinder, 22... Piston rod, 23... Push rod, 24... Rod guide, 25... Original frame, 26... Crank rod, 27... Cutting arm, 28... Guide frame, 29... Cutting bit, 30... Projection hole, 31...Drilling blade, 32a...Arc-shaped groove, 32b...Straight groove, 33a...Pin, 33b...Pin, 34...Carbide tip, 35...Bit holder, 36...Cut surface, 37...Cover, 38...Cutting device , 39... Drive unit, 40... Motor, 41... Extension rod, 42... Fixed flange, 43... Flexible joint, 44... Threaded rod, 45... Moving nut, 46... Connection arm, 47... Slider, 48... Inclined groove, 49 ...Pin, 50...Guide frame, 51...Sequence valve, 52...Pressure oil port, 53...Pressure oil port, 54...Pressure oil port, 55...Pressure oil port, 56...Pedestal, 57...Groove.

According to the invention described in claim 1,
An existing pile cutting device that rotates a cylindrical casing to excavate a pull-out hole on the outer periphery of an existing pile buried in the ground using an excavator connected to heavy equipment, and pulls out and removes the existing pile,
A protruding hole is drilled in the casing at the cutting point of the existing pile, a cutting device equipped with a cutting bit is provided facing the protruding hole, and the cutting bit is inserted into the casing to which the cutting device is attached. A drive unit that moves forward and backward from the outside of the hole to the inside is provided, and the cutting bit is pressed from the protruding hole to the existing pile while rotating the casing to cut the existing pile,
The cutting device includes a cutting arm having the cutting bit attached to one end thereof, a guide frame for guiding the cutting arm to the protrusion hole, and a slidable member that is bendably connected to the other end of the cutting arm. Equipped with a crank rod,
The cutting arm has an arcuate shape, the guiding frame is an arcuate frame, and the cutting bit at one end of the cutting arm is guided by the arcuate frame to advance and retreat into the protrusion hole. A cutting device for existing piles.
Therefore, it has the following effects.
(1) If the existing piles are long, it is possible to cut and remove only the part that gets in the way of the top end, without having to pull out all the existing piles from the base in order to construct a new structure.
(2) Even long existing piles can be cut to a predetermined length and pulled out one after another, resulting in excellent pulling workability.
(3) The cutting bit can be moved forward and backward from the protrusion hole in a narrow space outside the casing.
(4) The reciprocating motion of the cutting arm on the outer periphery of the casing can be converted into the forward and backward motion of the cutting bit into the protruding hole.

According to the invention as claimed in claim 2 ,
The drive unit includes a hydraulic jack and a slidable push rod whose one end is connected to the piston rod of the hydraulic jack and the other end is connected to the crank rod, so that the reciprocating motion of the hydraulic jack is can be smoothly transmitted to the cutting bit.

According to the invention recited in claim 3 ,
The casing includes a top casing attached to the excavator and located on the ground, a tip casing at a cutting position of the existing pile, and an intermediate casing connecting these, and the tip casing has a top casing located on the ground. The device and the drive section are provided, a stroke instruction cylinder for controlling the hydraulic jack is provided in the top casing, and the hydraulic jack and stroke instruction cylinder are connected by an oil pipe, so that the cutter is driven underground. The movement of the device and the drive unit can be visually confirmed with a stroke indicating cylinder on the ground.

According to the invention described in claim 4 ,
The drive unit includes a motor, a threaded rod connected to a rotating shaft of the motor, a moving nut that converts the rotation of the threaded rod into reciprocating motion, one end of which is connected to the moving nut, and the other end of which is connected to the moving nut. Since it consists of a connecting arm connected to the crank rod, the stroke of the cutting bit, etc. of the cutting device can be controlled by the rotation of the motor.

According to the invention described in claim 5 ,
An existing pile cutting device that rotates a cylindrical casing to excavate a pull-out hole on the outer periphery of an existing pile buried in the ground using an excavator connected to heavy equipment, and pulls out and removes the existing pile,
A protruding hole is drilled in the casing at the cutting point of the existing pile, a cutting device equipped with a cutting bit is provided facing the protruding hole, and the cutting bit is inserted into the casing to which the cutting device is attached. A drive unit that moves forward and backward from the outside of the hole to the inside is provided, and the cutting bit is pressed from the protruding hole to the existing pile while rotating the casing to cut the existing pile,
The cutting device is provided with a slider that slides within a guide frame provided in the longitudinal direction of the casing on the outside of the casing including the protruding hole, and a pin provided on the cutting bit is inserted into an inclined groove formed in the slider. , the slider is connected to the drive section, and the cutting bit is provided in the protruding hole so as to be movable forward and backward by the reciprocating movement of the slider .
Therefore, the cutting bit can be pressed perpendicularly to the surface of the existing pile to cut it.

According to the invention described in claim 6 ,
A plurality of cutting devices are provided around the outer periphery of the casing with substantially the same center angle, so even if the existing pile is deviated from the center of the casing, the plurality of cutting bits are pressed approximately equally, and the existing pile is aligned with the center of the casing. Existing piles can be cut efficiently by adjusting the position.

According to the invention described in claim 7 ,
A plurality of cutting devices are provided around the outer periphery of the casing with substantially the same center angle, so even if the existing pile is deviated from the center of the casing, the plurality of cutting bits are pressed approximately equally, and the existing pile is aligned with the center of the casing. Existing piles can be cut efficiently by adjusting the position.

Claims (8)

An existing pile cutting device that rotates a cylindrical casing to excavate a pull-out hole on the outer periphery of an existing pile buried in the ground using an excavator connected to heavy equipment, and pulls out and removes the existing pile,
A protruding hole is drilled in the casing at the cutting point of the existing pile, a cutting device equipped with a cutting bit is provided facing the protruding hole, and the cutting bit is inserted into the casing to which the cutting device is attached. The method is characterized in that a drive unit is provided that moves forward and backward from the outside of the hole to the inside, and the cutting bit is pressed from the protruding hole to the existing pile while rotating the casing to cut the existing pile. A cutting device for existing piles. The cutting device includes a cutting arm having the cutting bit attached to one end thereof, a guide frame for guiding the cutting arm to the protrusion hole, and a slidable member that is bendably connected to the other end of the cutting arm. The existing pile cutting device according to claim 1, further comprising a crank rod. The cutting arm has an arcuate shape, the guiding frame is an arcuate frame, and the cutting bit at one end of the cutting arm is guided by the arcuate frame to advance and retreat into the protrusion hole. 3. The existing pile cutting device according to claim 2. 2. The drive unit includes a hydraulic jack and a slidable push rod having one end connected to the piston rod of the hydraulic jack and the other end connected to the crank rod. Existing pile cutting device according to 2 or 3. The casing includes a top casing attached to the excavator and located on the ground, a tip casing at a cutting position of the existing pile, and an intermediate casing connecting these, and the tip casing has a top casing located on the ground. 5. The oil pump according to claim 4, further comprising: a device and the drive unit; a stroke instruction cylinder for controlling the hydraulic jack; provided in the top casing; and an oil feed pipe connecting the hydraulic jack and the stroke instruction cylinder. equipment for cutting existing piles. The drive unit includes a motor, a threaded rod connected to a rotating shaft of the motor, a moving nut that converts the rotation of the threaded rod into reciprocating motion, one end of which is connected to the moving nut, and the other end of which is connected to the moving nut. The existing pile cutting device according to claim 2, further comprising a connecting arm connected to the crank rod. The cutting device is provided with a slider that slides within a guide frame provided in the longitudinal direction of the casing on the outside of the casing including the protruding hole, and a pin provided on the cutting bit is inserted into an inclined groove formed in the slider. 2. The cutting device for an existing pile according to claim 1, wherein the slider is connected to the drive unit, and the cutting bit is provided in the protruding hole so as to be movable forward and backward by the reciprocating movement of the slider. 2. The existing pile cutting device according to claim 1, wherein a plurality of said cutting devices are provided on the outer periphery of said casing with substantially the same central angle.

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