JPH10299373A - Expansion cutting edge opening/closing device for excavating rod - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform enlarged excavation with expansion cutting edges by normal rotation of an excavating rod and omit combined use of a hollow pile. SOLUTION: Each of a plurality of expansion cutting edges 6 is supported to the lower end part of an excavating rod, oscillatingly on a vertical plane so as to be opened and enlarged being oscillated by earth pressure at the time of normal rotation of the excavating rod and to be closed and contracted into an overclosed-contracted position in the same direction via a vertical closed-contracted position being oscillated by earth pressure at the time of reverse rotation. An opening impeding stopper 9 for the expansion cutting edge 6 is provided in such a way as to be able to advance/retreat into a position of impeding opening oscillation of the expansion cutting edge 6 from the vertical closed-contracted position and a position of releasing the impediment of opening oscillation. A starting member 10 for starting advance/retreat of the stopper 9 is provided in such a way as to retreat being pushed by the oscillation of the expansion cutting edge 6 from the vertical closed-contracted position to the overclosed-contracted position and to springily advance being released from pushing by the oscillation of the expansion cutting edge 6 from the overclosed-contracted position. Drive mechanism for the stopper 9 for alternately driving the stopper 9 to advance into the position of impeding the opening oscillation of the expansion cutting edge 6 and to retreat into the position of releasing the impediment of opening oscillation of the expansion cutting edge 6 every retreat of the starting member 10 being pushed by the expansion cutting edge 6 is provided between the starting member 10 and the stopper 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an opening and closing device for an enlarged blade mounted on a tip of a drill rod such as an auger screw used for forming a cast-in-place pile having an enlarged bulb at a lower end.

[0002]

2. Description of the Related Art Conventionally, as an auger screw expanding blade opening / closing device, a pair of expanding blades at the tip of an auger screw are closed and contracted by earth pressure when the auger screw is normally rotated (during normal excavation) and reversely rotated. Sometimes it expands due to earth pressure,
Although it is known to pivotally open and close freely on a vertical plane, this conventional example requires the auger screw to be reversed when performing the expanded digging by expanding the expanding blade,
The excavated soil was pushed back into the enlarged hole excavated by the enlarging blade and accumulated densely, which was an obstacle to hindering the expected bulb formation during the next mortar injection.

Further, as another conventional example, a pair of enlarged blades are supported at the tip of an auger screw so as to be swingably openable and closable on a vertical surface while being constantly resilient in the expanding direction by a spring.
When inserting this auger screw in a hollow pile with its expanding blade closed, and when performing expanded digging,
It has been proposed that the expanding blade is extended from the lower end of the hollow pile by projecting from the lower end of the hollow pile by a spring, and automatically retracted by pulling up the expanding blade into the hollow pile after work. There is a disadvantage that it must be used in combination with a hollow pile and cannot be used for the so-called external digging method of building a hollow pile after excavation work.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides a new enlarged blade opening and closing method which enables reliable bulb formation by performing enlarged digging with an enlarged blade by forward rotation of a digging rod, and which can also be used for an external digging method. It is an object to provide a device.

[0005]

In order to solve the above-mentioned problems, a first invention of the present application is to expand a plurality of enlarged blades at the lower end of a drilling rod by swinging due to earth pressure at the time of forward rotation of the drilling rod. In the reverse rotation, the rocker is swingably supported on the vertical surface so as to swing by the earth pressure and to contract in the same direction through the vertical contraction position to the excessive contraction position. A movable member is provided at a position where the expanding blade is prevented from expanding and oscillating from the vertical closing position and a position where the expanding oscillating prevention is released, and an activation member that activates the stopper is configured to activate and retract. The expanding blade is pushed by the swing from the vertical contraction position to the excessively contracted position and retreats, and the pushing is released by the swing of the enlarged blade from the excessively contracted position to the vertical contraction position, so that the elasticity is elastic. And between the actuating member and the stopper, Each retraction of has been actuation member,
An enlarged blade opening / closing device for a drilling rod, provided with a stopper drive mechanism for alternately driving the advancement of the stopper to the enlarged blade widening rocking prevention position and the retraction to a position where the widening blade widening rocking inhibition is released. And propose

According to a second aspect of the present invention, a plurality of sets of brackets projecting from the lower end of a drilling rod each support a supporting shaft, and each of the supporting shafts swings an enlarged blade by earth pressure when the drilling rod rotates forward. The support shaft axis so as to swing on a vertical plane so as to swing by the earth pressure at the time of reverse rotation and to contract in the same direction through the vertical contraction position to the excessive contraction position. The blade is slidably supported in the direction, and the expansion-preventing stopper of the expanding blade is used to prevent the expanding blade from expanding and oscillating from the vertical closing position when the one end of the support shaft slides. Intercept,
When the other end is slid, it is fixed at a position where the above-mentioned expansion rocking prevention is released, and the expansion blade is swung by the expansion blade on the engagement peripheral surface between the expansion blade and the support shaft. A cylindrical cam and a follower are slid to a position for receiving the expansion inhibition and a position for receiving the expansion inhibition release, and the cylindrical cam is moved by the cylindrical cam when the expanding blade is swung from the vertical closed position to the excessive closed position. When the expanding blade is slid to a position for receiving the release of the stopper expansion inhibition, and when the expansion blade swings from the excessively closed / contracted position, the expansion blade releases the stopper expansion inhibition release without operating the cylindrical cam. While the receiving position is maintained, the expanding blade is swung to the vertical closing position, and the expanding blade is slid to a position where the stopper prevents the stopper from being expanded by the cylindrical cam. Cam control mechanism Provided the propose expanding blade switchgear in drill rod.

The "digging rod" in the present invention includes an auger screw, a stirring rod, and various other drilling rods. Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0008]

1 to 8 show an embodiment in which the first invention of the present application is applied to an auger screw. The outer peripheral surface of the lower end of a hollow rod (3) in a drilling head (2) connected to the lower end of a screw rod (1) is shown in FIGS. The gearboxes (4) and (4) are mounted at mutually symmetrical positions in the diameter direction, and two side brackets (5) and (2) parallel to the axial direction of the rod (3) are provided on one side of each of the gearboxes. 5), and one end of each of the plate-shaped enlarged blades (6) and (6) bent in an outwardly-curved shape is attached to both brackets (5) and (5). (7) is pivotally supported on a vertical surface so that the shafts (7) and (7) of the enlarged blades (6) and (6) are hollowed out as shown in FIG. The rod (3) is arranged at a small interval parallel to the center line (d) of the cross section of the rod (3), so that the When the menu is rotated forward, the expanding blades (6) and (6) swing by the earth pressure to reach a horizontal expanding position of an imaginary line abutting on the regulating stopper (8) as shown in FIG. In this case, it is also swung in the opposite direction by the earth pressure and passes through the vertical contraction position shown by the solid line in FIG. 1 and further contacts the other gear box (4) as shown in FIG. It is designed to reach the position of excessive contraction of the line.

The structure inside the gearboxes (4), (4) is as follows. On one side of both boxes (4) and (4) where the expanding blades (6) and (6) are supported, a round bar-shaped expansion prevention stopper (9) and (9) can be moved out of the box. The stoppers (9), (9) are slidably supported as described above, and when the expanding blades (6), (6) are in the vertical contraction position or the excessive contraction position, the stoppers (9), (9) ) And (6) can be advanced on the trajectory, and when the oscillating blade is advanced, the expanding blades (6) and (6) are prevented from expanding and oscillating from the vertical closing position. The enlarged blade (6),
The positional relationship allows the swinging movement of (6).

On the other side of the boxes (4) and (4), rack teeth (11) are provided on the side surface and round bar-shaped starting pins (10) and (1) each having a retaining flange at the base end.
0) is slidably supported so as to be able to advance and retreat out of the box, and is always resilient in the advance direction by springs (12) and (12).
(10) Enlarged blades (6) and (6) for the other box
Is in the vertical closing position, the closing blades of the expanding blades (6), (6) are elastically advanced to a position where the tip of the pin abuts or approaches the side surface, and the expanding blade (6). ), (6)
When the enlarged blades (6), (6) are swung in the expanding direction from the excessively contracted position by being pushed and retracted by the swing from the vertical contraction position to the excessively contracted position, the expansion blade is pushed. And is elastically returned to the original advanced state.

A stopper driving mechanism for moving the stoppers (9) and (9) by moving the starting pins (10) and (10) forward and backward is as follows. Referring to one drive mechanism, in FIGS. 3 and 7, a pinion (13) meshing with the rack teeth (11) of the starting pin (10) has a shaft (14) rotatably supported at both ends by a box (4). ) And a large gear (16) supported on the shaft (14) via a wedge one-way clutch (15), and a small gear (17) meshing with the large gear (16) is fixed to a box (4). Is fixed to a shaft (18) that is rotatably supported, and one of the two crank disks (19) is attached to the square shaft portion at the tip of the shaft (18) and the other circle to the other. The single plate is non-rotatably fitted to the square shaft portion of the shaft (20) rotatably supported at one end by the box (4), and one end of the connecting rod (21) is interposed between the two single disks. Connect with the crank pin (22) between The other end portion (21) are connected by a pin (23) to the rear end of the stopper (9).

When the shaft (14) rotates clockwise in FIG. 3 by the rotation of the pinion (13) when the starting pin (10) is retracted, the one-way clutch (15)
The clutch is closed to rotate the large gear (16) in the same direction, but the shaft (14) is rotated counterclockwise in FIG. 3 by the rotation of the pinion (13) when the retracted starting pin (10) is advanced by the spring (12). When it rotates in the direction, the clutch is opened to keep the gear (16) in a stopped state.
0) only when the crank disc (19)
Of the connecting rod (2
The stopper (9) moves forward and backward via 1).

In this case, the rotation of the crank disk (19) caused by the retreat of the starting pin (10) is controlled by the rotation of the crank pin (2).
2) 180 ° rotation from one thought point (position in FIG. 3) overlapping the center line of the connecting rod (21) to the other thought point overlapping the extension of the center line of the connecting rod (21); The rotation of the crank disc alternately moves the stopper (9) back and forth between the longest advance position and the shortest retreat position. Become.

The operation of the above example will now be described. Figures 1, 2, 3
With the expanding blades (6) and (6) in the vertically closed position as described above, the auger screw is rotated forward to start excavating a vertical hole in the ground. The expanding blades (6) and (6) try to expand by the earth pressure, but are prevented from expanding by the stoppers (9) and (9) and stay at the vertical closed position.

When the depth reaches a predetermined depth, the auger screw is switched from normal rotation to reverse rotation. By this reversal, the expansion blade (6),
(6) swings to the over-closed position by the earth pressure as shown in FIG. 4, and the swinging causes the starting pins (10) and (10) to move the springs (12) on the side surfaces of the enlarged blades (6) and (6). ), (1)
2), the retraction of the starting pin is caused by the rack teeth (11), (11), pinions (13), (13), shafts (14), (14), one-way clutch (15),
(15), large gear (16), (16), small gear (1
7) and (17) through the crank disks (19) and (1)
9) is rotated counterclockwise by 180 degrees, and this is connected to the stoppers (9), (9) via the connecting rods (21), (21).
Is retracted so that the expanding blade can be expanded.

Then, when the auger screw is rotated forward, the enlarged blades (6) and (6) expand as shown in FIG. By the expansion of the expanding blade, the pushing of the starting pins (10) and (10) is released, and the starting pins are released from the springs (12) and (1).
2), but the pinion (1
3), (13) and the counterclockwise rotation of the shafts (14), (14) are not transmitted to the large gears (16), (16) due to the opening of the one-way clutches (15), (15). The crank disks (19), (19) continue to stop at the rotational position of FIG. 4 and keep the stoppers (9), (9) in the retracted position.

The normal rotation is continued in the above-described enlarged blade expanding state, and a predetermined enlarged digging is performed to form a bulb.

After the work is completed, when the auger screw is reversed again, the expanding blades (6) and (6) swing to the vertical contraction position and then to the excessive contraction position by the earth pressure, and the starting pin (10) , (10) as shown in FIG. 6, and by retreating the starting pin, the crank disk (19) is rotated 180 degrees counterclockwise to stop the stoppers (9) and (9) from enlarging the expansion blade. Advance to position. In this state, the auger screw is pulled out to the ground while rotating forward, but even if the expanding blades (6) and (6) try to expand by the earth pressure during the pulling, the stoppers (9) and (9) move to the vertical closed position. Will be retained.

Next, an example in which the second invention of the present application is applied to an auger screw will be described. 8 and 9, the outer peripheral surface of the lower end of the hollow rod (3a) of the drilling head (2a) connected to the lower end of the screw rod is parallel to the axial direction of the rod (3a) at mutually symmetrical positions in the diameter direction. 2
The brackets (5a) and (5a) having a single-sheet construction are protruded, and the support shafts (7a) and (7
a) a plate-shaped enlarged blade (6a) bent in an outwardly-curved shape;
Each end of (6a) is supported so as to be swingable on a vertical plane and slidable in the axial direction by a required distance.
Similarly to the enlarged blade 3, when the auger screw is rotated forward in the direction of the arrow in FIG. 9, the enlarged blades (6 a) and (6 a) oscillate due to the earth pressure, and the regulating stopper (8 a) as shown in FIG.
When the imaginary line abutting on (8a) reaches the horizontal widening position, and when it reverses, it also oscillates in the opposite direction due to earth pressure and further oscillates by 45 degrees from the vertical contraction position shown by the solid line to excavation head (2a ), The imaginary line contacting the blade is brought to the excessively contracted position.

[0020] Both brackets (5a) of the two-sheet configuration described above,
The expansion blades (6a), (6a), and the expansion prevention stoppers (9a), (9a) which partially protrude into the swinging orbit of the (6a) are fixed to one of the brackets in (5a). The positional relationship between the stopper and the enlarging blade is such that the enlarging blades (6a) and (6a) correspond to the stoppers (9a) and (9).
When the bracket alone having a) slides on the side, the enlarged blades (6a) and (6a) are moved by the stoppers (9a) and (9).
a) prevents the swinging movement from the vertical closing position, and when the bracket without the stoppers (9a) and (9a) slides, the expanding blades (6a) and (6)
a) is disengaged from the stoppers (9a) and (9a) and is allowed to swing from the vertical closing position.

A description will now be given of a cam mechanism for sliding the enlarged blades (6a) and (6a) and a cam control mechanism for controlling the cam. Looking at the mechanism of one of the enlarged blades (6a), the support shaft (7a) is disposed on the outer peripheral surface of the engagement with the enlarged blade (6a) at intervals of 180 degrees as shown in a developed view of FIG. 60-degree wide chevron lift grooves (26a), (26
a) and a 120 degree stop groove (27) connecting them.
a) and (27a) are provided with two cylindrical groove cams (25a), and two engagingly slidably engaging inside the cylindrical groove cams (25a) on the engaging inner peripheral surface of the enlarged blade (6a). The driven projections (28a) and (28a) are projected at intervals of 180 degrees. In this case, the lift amount of the cylindrical cam (25a) is
This corresponds to a sliding distance at which the enlarged blade (6a) slides from the position where the enlarged bracket (6a) comes into contact with the bracket with the stopper (9a) and the other bracket alone slides away from the expansion prevention of the stopper (9a).

The cylindrical cam (25a) and the driven projections (28a) and (28a) are provided with the driven projections (28) when the expanding blade (6a) is in the vertical closing position (the state shown in FIG. 9).
a) and (28a) are located at the top of the lift grooves (26a) and (26a).

As the cam control mechanism, the support shaft (7a)
The one-way clutches (15a) and (15a) are interposed on the engaging peripheral surface between both ends of the bracket and the single body of the bracket (5a), and the clutches (15a) and (15a)
When a) swings in the expanding direction, the clutch is opened by allowing the support shaft (7a) to rotate in the same direction, thereby allowing the rotation. The clutch is closed with respect to the support shaft (7a) which is about to rotate in the same direction to prevent rotation.

Further, the enlarged blade (6a) and the support shaft (7)
A friction material (29a) such as a nonwoven fabric or a brushed cloth is interposed on the engaging peripheral surface of (a), and the enlarged blade (6a) when the clutches (15a) and (15a) are opened by the friction material. When the clutches (15a) and (15a) are closed, the support shaft (7a) rotates even when the enlarged blade (6a) swings. Does not rotate.

The operation of the above example will now be described. When the vertical hole is excavated in a state where the enlarged blades (6a) and (6a) shown in FIGS. 8 and 9 are in the vertical contraction position, and when a predetermined depth is reached, the auger screw is switched from normal rotation to reverse rotation. (6a),
(6a) swings 45 degrees from the vertical contraction position to the excessive contraction position by the earth pressure, and at this time, a one-way clutch (15a) ...
Is closed and the support shafts (7a) and (7a) are in a stationary state, so that the driven protrusion (28a) of the enlarged blade is a lift groove (26a).
11 slides 45 degrees from the position (a) in FIG. 11 to reach the position (b) of the stop groove (27a)..., And the enlarged blades (6a) and (6a) become the other bracket alone by the lifting action. It slides on the alligator and separates from the stoppers (9a) and (9a). When the auger screw is rotated forward in this state, the expanding blades (6a) and (6a) swing in the expanding direction due to earth pressure, and at this time, the one-way clutch (15a)
Are opened and the support shafts (7a) and (7a) are
a) and (6a), the driven projection (2)
8a) remain at the position (b) in FIG. 11 and the enlarged blades (6a) and (6a) are connected to the stopper (9a),
(9a) is kept at a position where it is detached from, so that the expanding blades (6a) and (6a) expand to the horizontal expanding position via the vertical closing and contracting positions (the state of FIG. 10).

The normal rotation is continued in the above-described enlarged blade expanding state, and a predetermined enlarged excavation is performed to form a bulb.

After the work is completed, when the auger screw is rotated again, the expanding blades (6a) and (6a) swing from the horizontal expanding position to the vertical closing position by 90 degrees, and then further to the excessive closing position by 45 degrees. At this time, since the clutches (15a)... Are closed and the support shafts (7a) and (7a) are in a stationary state, the driven protrusion (28) at the position (b) in FIG.
a) moves 90 degrees to the position (c), then 4
It moves 5 degrees to reach the position of (d) of the lift groove (26a)... The lift action causes the enlarged blades (6a) and (6a) to slide on the bracket with stopper and the stopper (9a). The position reaches the position where the expansion is prevented in (9a).
When the auger screw is pulled up to the ground while rotating forward in this state, the expanding blades (6a) and (6a) return to the vertical closed position at the time of forward rotation, and the expansion is prevented by the stoppers (9a) and (9a). You. The driven projections (28a)... Remain at the position (d) in FIG.

[0028]

According to the expansion blade opening / closing device for the drill rod of the first invention of the present application, if an appropriate reverse rotation operation of the drill rod is performed before the expansion digging, the expansion blade is expanded by the forward rotation of the drill rod. It is possible to perform the expanded excavation in this way, and it is possible to reliably excavate the desired enlarged hole, and since there is no need to use a hollow pile together, there is also an advantage that it can be used for various enlarged excavation methods. It is done.

According to the enlarged blade opening and closing device for the excavating rod of the second invention of the present application, in addition to the effect of the first invention, there is obtained an advantage that the opening and closing device can be downsized.

[Brief description of the drawings]

FIG. 1 is a front view of a cutting head portion of an auger screw.

FIG. 2 is a side view of the same.

FIG. 3 is an enlarged sectional view taken along line III-III of FIG. 1;

FIG. 4 is a partially cutaway view of the state in which the expanding blade in FIG. 3 is swung to an over-closed position.

FIG. 5 is a sectional view of the same as above in a state where the expanding blade in FIG. 4 is swung to a horizontal expanding position.

FIG. 6 is a sectional view of the same as above in a state where the expanding blade in FIG. 5 is swung to an over-closed position.

FIG. 7 is an enlarged sectional view taken along line VII-VII of FIG. 3;

FIG. 8 is a front view of a digging head portion provided with another enlarged blade opening / closing device.

FIG. 9 is an enlarged sectional view taken along line IX-IX of FIG. 8;

10 is a partially cutaway view of the state in which the expanding blade in FIG. 9 is swung from the excessively closed position to the horizontal expanded position.

FIG. 11 is an enlarged development view of a cylindrical groove cam.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Screw rod 2, 2a Excavation head 5, 5a Bracket 6, 6a Enlarged blade 7, 7a Support shaft 9, 9a Expansion prevention stopper 10 Starting pin 12 Spring 25a Cylindrical groove cam 28a Follower projection

Claims (2)

[Claims] At the lower end of a drilling rod, a plurality of expanding blades are swung by the earth pressure when the drilling rod rotates forward, and expanded, and are swung by the earth pressure when the drilling rod rotates backward to set the vertical closing position. Respectively, and swingably supported on a vertical plane so as to close and contract to the excessively contracted position in the same direction. A movement member for movably and advancing and retracting the stopper from the vertical closing position to the excessive closing position; Is pushed back and is provided so that the pushing is released by the swinging of the expanding blade from the excessively contracted position to the vertical closed position to resiliently advance, and between the activation member and the stopper, Each time the starting member is retracted by being pushed by the expanding blade, the stopper An enlarged blade opening / closing device for a drilling rod, further comprising a stopper drive mechanism for alternately driving advancement to an enlarged blade expansion rocking prevention position and retraction to a position for canceling the expansion blade expansion rocking inhibition. 2. A support shaft is supported by a plurality of sets of brackets protruding from a lower end of a drilling rod, and an expanding blade is swung on each support shaft by earth pressure when the drilling rod rotates forward to expand. Open and swing by the earth pressure at the time of reverse rotation and swing in the same direction via the vertical contraction position and close in the same direction to the excessive contraction position. Freely supporting the expansion-prevention stopper of the expanding blade, preventing the expansion blade from swinging from the vertical closing position when the expanding blade slides at one end of the support shaft; When the end slides, it is fixed at a position where the above-described expansion swing inhibition is released, and the expansion blade is swung on the engagement peripheral surface between the expansion blade and the support shaft by the expansion blade so that the stopper is expanded. Providing a cylindrical cam and a follower to be slid to a position to receive the opening prevention and a position to receive the expansion prevention release, When the expanding blade is swung from the vertical closing position to the excessive closing position, the expanding blade is slid by the cylindrical cam to a position where the stopper is prevented from being expanded, and the expanding blade is expanded from the excessive closing position. When the open and swing operation is performed, the expansion blade is expanded while the cylindrical cam is not operated, while maintaining the position where the stopper expansion release inhibition is released, and the expanded expansion blade is swung to the over-closed contraction position. An expanding blade opening / closing device for a drilling rod, further comprising a cam control mechanism for causing the expanding blade to slide to a position where the stopper prevents expansion of the stopper by the cylindrical cam.