JP3374207B2 - Hammer club drilling equipment for earth drills - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hammer drilling apparatus for use in an earth drilling method in which a concrete pile is cast in place after rotary drilling.

[0002]

2. Description of the Related Art Conventionally, the innermost kelly bar of an extendable kelly bar that is normally and reversely driven by a rotary table of a vehicle-mounted rotary machine.
An earth drill for rotating and drilling a pile hole with a drilling bucket attached to the lower end is known from, for example, Japanese Utility Model Publication No. 5-47819, but the construction method for casting a concrete pile in place using this earth drill is Compared to other Benot method and Reverse Circulation method, labor cost and machine price are cheaper, drilling speed is high, and the required construction distance from the boundary of the work site to the pile core is small, making it suitable for small work sites. It is widely used in urban areas because it is easy to install the earth drill.

However, even in the geological condition of sandstone or more, the drilling bucket is replaced with a chipping bucket, and the chipping bucket is returned to the drilling bucket by returning the bucket in a percussion type. Although it can be perforated by digging up, the grain size (size) 1
In a gravel layer with a diameter of 2 or more, drilling teeth at the bottom of the drilling bucket slide on the gravel layer, making it difficult to drill, and boulders and boulders (below the size of the drilling waste passage opening of the drilling bucket bottom plate) It is not possible to pierce the formation containing boulders).

This boulder formation should have been able to be pierced by the Hammaglab piercing device described in Japanese Utility Model Publication No. 34-18232. However, when gravel straddling the inside and outside of the hole wall to be pierced is buried in the ground, There is a case where the turning angle position of the Hammaglab cannot be adjusted so that the teeth of the Hammaglab come into contact with the boulder, which may make it impossible to perforate. This is because if you use a stabilizing solution to prevent collapse of the hole wall, you can not rotate the hammer mug according to the position of the boulder, and put a worker in the excavated hole and manually dig the lower part of the boulder. Therefore, it is not possible to use a method in which the boulders are rolled into the holes and then taken out by a hammer mag.

[0005]

The problem to be solved is to make a hammer plug which is difficult to adjust the turning angle position into a percussion type when the boulders at the bottom of the hole extending inside and outside the hole to be drilled cannot be visually observed. By simply dropping it again, the boulder protruding portion into the hole to be drilled cannot be crushed or broken, and the boulder cannot be taken out from the hole bottom.
This is the point where drilling is impossible.

[0006]

SUMMARY OF THE INVENTION The present invention relates to an engaging body attached to the lower end of the innermost kelly bar of a telescopic kelly bar that is rotatably supported by a crane suspension line of an earth drill, and is always urged to rotate to an open position. A pair of left and right bucket blades is pivoted on both sides of the lower end of a vertical cylindrical support casing, and a hook body and left and right bucket blades so that the hammer plate is closed by the gravity action at the time of lifting. A booster in a tubular support casing for interlocking connection between the suspension device and the suspension device; a suspension cylinder having the same axis as the upper end of the tubular support casing; Hammaglab retaining ring mounted coaxially with the rotary table on the lower side of the rotary machine of the earth drill so that the upper end of the cylinder can be selectively hung and removed,
An engaging claw that is always urged to rotate in the hanging cylinder is suspended in the hanging cylinder so as to prevent only the lifting of the engaging body with respect to the hanging cylinder when the hanging cylinder rises with respect to the cylindrical supporting case. A hammer drilling device for a ground drill, which comprises a one-way gripping device attached to the upper end of a tubular support casing so that the engaging body can be retracted upward with respect to the hanging cylinder when the lower cylinder descends. Removably fixed to the lower end of the inner kelly bar,
Moreover, the socket-shaped engaging element with the engaging element main body at the lower end,
Regardless of whether the hammer grip is open or closed, it is constructed so that it can be slidably fitted in the hanging cylinder at all times, and on the outer wall of the left and right bucket blades that form the vertical cylindrical portion when opened, the diameter of each Vertical boring teeth projecting downward from the elliptical lower edge of the bucket blade at both ends are fixed so that the lower ends of the both boring teeth are located on substantially the same horizontal plane, and when the hammer tab is closed, The main feature is that the two digging teeth are configured so as to be inconsistent with each other.

In order to cope with the loss of the digging teeth and the improvement of the drilling efficiency, the ellipse of the bucket blade is formed on the outer wall of the left and right bucket blades forming the vertical cylindrical portion at the opening at both ends on the diameter line. A plurality of vertical boring teeth projecting substantially constant length below the bottom edge of the shape, to form a boring tooth group for each of the left and right bucket blades, and to form the boring tooth group in the open position. It is preferable to configure the corresponding drilling teeth of the left and right bucket blades so that the corresponding drilling teeth of the left and right bucket blades are inconsistent with each other when the space between corresponding terminals is made larger than the length of each drilling tooth group when closing In the case, the outer walls of the left and right bucket blades that form the vertical cylindrical portion when opened are vertically dug down below the elliptical lower edge of the bucket blade at both ends on the diameter line. Fix a plurality of sets of teeth so that the lower ends of the sets of drilling teeth of the left and right bucket blades on the open position are located on the same horizontal plane so that the corresponding drilling teeth of both bucket blades do not conflict with each other when the hammer rack is closed. It can also be configured to. In either case, it is preferable that the leading edge and the lower edge of each of the drill teeth, which are detachably attached to the left and right bucket blades, in the direction of rotation of the hammer mug are V-shaped blades.

[0008]

EXAMPLE As shown in FIG. 3 and FIG.
A telescopic boom (may be a mast) 5 mounted on a swivel base 3 swivelly mounted on a crawler traveling device 2 by means of a delicate cylinder 4, and a winding cylinder device on the swivel base, and the boom tip is extended. Telescopic kelly bar 8 hung via a swivel joint 7 on a crane suspension line 6 via the pulley of
Innermost kelly bar 18, a guide member 12 which is connected to the base of the boom 5 via upper and lower link members 9 and 10 and is vertically held by a double-acting hydraulic cylinder 11, and is supported by the guide member only so as to be vertically movable. Being a telescopic Kelly bar 8
A rotary machine 13 for driving a rotary machine 13 and a collar 14a fixed to the middle of the cylinder are elastically supported by the guide member 12 via upper and lower compression springs 55 and 56 so as to be vertically displaceable, and a drilling bucket attached to the lower end of the kelly bar. And a vertical double-acting hydraulic cylinder 14 that frictionally pushes down and urges the rotary machine 13 at the time of rotary drilling by a tool (not shown).
When the boom 5 is a mast, it is obvious that the guide member 12 can be directly attached to the mast.

As shown in FIG. 4, the telescopic kelly bar 8 has an outermost kelly bar 15 having a square cross section and an intermediate kelly bar 16 and 17 having the same structure, and an innermost kelly bar 18 having a square bar shape, which are sequentially telescoped. Idling between a lower spring support 19 fitted and fixed near the lower end of the innermost kelly bar and an upper spring support 20 slidable with respect to the innermost kelly bar and receiving the lower ends of other kelly bars. However, a compression spring 21 is installed to absorb the shock caused by the fall of the kelly bar during expansion and contraction.
At the lower end of the innermost kelly bar 18 in which a is hung on the swivel joint 7, a removable pin 2 for mounting a drilling packet is attached.
A socket-shaped engaging element is removably fixed to each other by using 2.

For the convenience of processing, the socket-shaped engagement element is provided on a plate-shaped engagement element body 24 that cooperates with an engagement claw 23 of a one-way catching device described later, and a pair of left and right engagement claws are loosely fitted to the engagement element. The socket portion 25 having a square cross section, which is formed by cutting out a notch 25a (see FIG. 6) at the lower end, is integrally fixed, and the outer dimensions of the outer cross section of the socket-like engaging element (24, 25) are the same as those of the outermost kelly bar 15. Is almost equal to, and can always be slidably fitted in a suspension cylinder 46 described later to transmit the rotational force of the innermost kelly bar 18 to the suspension cylinder.

The hammag rack 26 is a vertical cylindrical support casing 27.
A pair of left and right bucket blades 29a and 29b pivotally supported by pivots 28 are provided on both sides of the lower end of each of the left and right bucket blades, and the inner ends of the left and right bucket blades are centered in the cylindrical support casing 27 via links 30a and 30b, respectively. Supporting plate 3 that is connected to the lower end of the pulley casing 31 disposed in the above-mentioned part and projects from the four corners of the pulley casing 31.
1a is the upper and lower mounting seats 3 fixed to the cylindrical support casing 27, respectively.
It is vertically movably supported by a vertical bolt-shaped rail 32 fixedly supported between 2a and 32b.

Reference numeral 33 denotes an upper mounting seat 32a and a support plate 31, respectively.
A compression spring sandwiched between a and a is shown.
Always pushes down the pulley casing 31 by its elasticity, and when there is no external force, the left and right bucket blades 29a, 29b.
Is held open at the open position shown in FIG. 4 by abutting engagement between the boss portion 34 of the pivot 28 and the stopper portion 35 of the cylindrical support casing 27. In this open position, the left and right bucket blades 29a, 29b form a vertical cylindrical portion centered on the Kelly bar rotation axis 0 shown in FIG. 8, but the pulley casing 31 is pulled up against the elastic force of the compression spring 33. At this time, the elliptical lower edges of the left and right bucket blades abut as shown in FIG. 1 to hold the hammer plate 26 in the closed position.

A booster for pulling up the pulley casing 31 against the elastic force of the compression spring 33 is provided with a wire rope 37, one end of which is connected to the center lower end of the engaging body 24 of the socket-like engaging element. A plurality of sheaves 39 attached to a horizontal shaft 38 in the housing and a plurality of sheaves 41 attached to a fixed horizontal shaft 40 in the tubular support housing 27 above the sheaves 39 are sequentially hung so as to form an interlocking sheave mechanism, Attach the end of the wire rope to the pulley casing 3
It is fastened 42 to 1. Hammaglab 2 when moving up and down
The fixed horizontal shaft 40 provided above the center of gravity of the hammer grab 26 and the fixed horizontal shaft 43 in the tubular support casing 27 provided above the fixed horizontal shaft 40 so that the vertical axis of 6 is substantially aligned with the rotation axis 0 of the Kelly bar. , A guide pulley 44 for aligning the upper wire rope 37 introduced into the booster with the axis of rotation of the kelly bar,
45 is attached.

A reference numeral 46 designates a guide tube 47 having a square cross section which is coaxially fixed to the upper end portion of the cylindrical support housing 27, and is slidably fitted within a certain range T (see FIG. 5) only in a fixed range T (see FIG. 5). 1 and 2, a bowl-shaped Hammaglab retaining ring 48 having a bottom inner diameter that prevents passage of a pair of protrusions 46a, 46a projecting from the upper end of the suspension cylinder 46 on both sides as shown in FIGS.
Is fixed to the lower side of the rotary machine 13 coaxially with the rotary table 58, and a fixed angle (90 in FIG.
A pair of notches 48a, 48a which allow the protrusions 46a, 46a to pass therethrough at the time of rotation are recessed inside the Hammaglab retaining ring 48. Reference numeral 46b designates a diameter-increasing guide portion for increasing the distance between the protrusions 46a on both sides of the suspension cylinder, and 46c a stopper fixed to the middle of the suspension cylinder 46 facing the upper end of the guide cylinder 47.
Reference numeral 46d denotes a stopper fixed to the lower end of the hanging cylinder 46 so as to face the lower surfaces of the pair of left and right gripping device mounting housings 49 fixed to the upper end of the cylindrical support case 27.

The one-way clasping device that cooperates with the above-mentioned engaging body 24 is eccentrically pivoted in the mounting housing 49 by shafts 50, and is constantly urged to rotate in the direction A of FIG. 5 by the action of gravity. A pair of left and right engaging claws 23, a hole 51 at the lower end of the suspending cylinder 46 with which the inner end of the engaging claw 23 engages, and when the suspending cylinder is raised with respect to the tubular support case 27 shown in FIG. The cylindrical support shown in FIG. 5 including a stopper 49a provided in the mounting casing 49 so as to receive the lower surface of the outer end portion of the engaging claw 23 whose inner end abuts and engages with the upper surface of the engagement body 24. When the suspending cylinder 46 descends with respect to the housing 27, the top end of the hole 51 at the lower end of the suspending cylinder pushes down the inner end of the engaging claw 23 so that the engaging body 24 can be lifted. It consists of a structure that can be pulled outside.

Therefore, the stopper 46 is attached to the lower end of the hanging cylinder 46.
The inner collar 46e provided so as to fix d is a stopper for restricting the lowering limit of the socket-like engagement element (24, 25) with respect to the suspension cylinder, and in the state of FIG. The gap B between the collar 46e and the flange 46e is smaller than the gap C between the top wall of the notch 25a provided at the lower end of the socket portion 25 of the socket-like engaging element and the top surface of the inner end portion of the engaging claw 23.

As shown in FIGS. 7 and 8, the left and right bucket blades 2 forming a vertical cylindrical portion in the open position.
The outer walls of 9a and 29b are drilling teeth 52a and 52b, which are located at both ends on the diameter line of the bucket blades and have a substantially constant protruding length below the elliptical lower edge of the bucket blade. 53a, 53b and the drill teeth 54a, 54b are detachably fixed vertically, and the protruding length of each drill tooth below the elliptical lower edge of each bucket blade configured as a blade is
It is preferable to set the boulder projecting portion into the hole to be drilled to about one-half to one-third of the target size of the boulder so that the hole bottom before and after the direction of rotation of the Hammaglab can be dug. The space S between the corresponding ends of the left and right bucket blades of the tooth group is greater than the length F of each of the tooth groups, and the space E between adjacent tooth of each bucket blade is When the hammer tab shown in FIG. 1 is closed, the corresponding digging teeth of the left and right bucket blades are set so as to be offset from each other. The bucket blade central angle θ between the adjacent boring teeth of each illustrated bucket blade is such that the two adjacent boring teeth can collide with boulders of a target size (for example, about 30 to 50 mm) at the same time. Is.

Therefore, each of the drill teeth is located on a circle M centered on the rotation axis 0 of the bucket blades 29a, 29b or the telescopic kelly bar 8 in the open position, and the hammer teeth in the rotational direction R of the hammer drill of the respective drill teeth. The leading edge and the lower edge are preferably V-shaped blades, respectively, as shown in FIGS. 8 and 4, so that boulders can be broken by a wedge action.

For the formation which can be drilled by a drilling bucket, the drilling is provided at the lower end of the telescopic kerry bar 8 which slidably passes through a rotary table 58 which can be driven by a plurality of hydraulic motors 57 in either forward or reverse directions. It is the same as in the prior art to attach a bucket and apply a punching thrust by using the frictional force between the rotary table 58 and the telescopic type kerry bar by pushing down the rotary machine 13 by the hydraulic cylinder 14 to punch a drilling bucket. There is a particle size of 12
When drilling a gravel layer or boulder layer that is more than pebbles, use a pin 2 at the lower end of the telescopic kelly bar instead of the drilling bucket.
The hammer grip 26 is attached to the lower end of the kelly bar via the socket-like engaging elements (24, 25) attached in 2.

As shown in FIG. 3, when the hammer mug 26 is being lifted from the hole D by a crane, the hammer mag is suspended and supported by the crane hanging rope 6 through the wire rope 37 and the innermost kelly bar 18 in order. The bucket blades 29a and 29b are closed by the output of the booster based on the pulling force of the wire rope 37. From this state, while the two protrusions 46a on the upper end of the hanging cylinder are pulled up into the retaining ring 48 through the notches 48a on both sides until reaching the position shown in FIG. 1, the retaining rack is used for transporting vehicles such as dump trucks and trucks. When the swivel base 3 is swung so as to be lifted above the loading platform, the rotary machine 13 rotates the kelly bar substantially at an angle position shown by a chain line in FIG. As shown, the bilateral projections abut and engage the bottom of the Hamma grab retaining ring 48.

Therefore, when the kelly bar 18 is further lowered by a crane, the hammer grab 26 is lowered by its own weight against the hanging cylinder 46 suspended by the hammer grip retaining ring 48,
Accordingly, since the suspension cylinder is relatively elevated with respect to the hammer grab, the engagement claw 23 is brought into contact with the upper surface of the engaging element body 24 as shown in FIG. Bottom hole 5
The engaging claw of which the outer end is received by the stopper 49a is rotated to the inside of the suspension tube through
Only the lifting of 4 is blocked, and the weight of the hammer plate 26 is received by the retaining ring 48.

Accordingly, as the kelly bar 18 descends, the input of the booster (tension of the wire rope 37) decreases, the elasticity of the compression spring 33 causes the pulley casing 31 to descend, and the link 30.
Left and right bucket blades 29a, 2 via a, 30b
As shown in FIG. 4, each of the 9b opens around the pivot 28, and the drilling scraps in the hammer drum are discharged onto a loading platform such as a dump truck.

Next, after returning the hanger mug or the innermost kelly bar 18 to the hole D, the kelly bar is slightly wound up and the both side projections 46a at the upper end of the hanging cylinder are hooked with the hanger mug retaining ring 48.
Of the outermost kelly bar 1 by lowering the crane rope 6 by rotating the kelly bar 18 in a reverse direction by a rotary machine so that the both protrusions face the notches 48a on both sides.
After engaging the upper end flange of No. 5 with the rotary table 58,
While extending the Hamma grab by the telescopic kelly bar, the socket-like engaging element (2
4, 25) and the hammer mug 26 suspended and supported via the wire rope 37 are dropped by its own weight so that the bucket blades 29a and 29b and the drilling teeth bite into the hole bottom.

When the hammer tab is thus supported on the bottom of the hole, the weight of the hammer tab acting on the innermost kelly bar 18 is lost, and the hanging tube 46 is lowered by its own weight with respect to the cylindrical support box 27 of the hammer tab so that the hanging tube 46 is suspended. The top end of the hole 51 at the lower end of the lower cylinder pushes down the inner end side of the engagement claw 23, and the inner end of the engagement claw is retracted from the inside of the suspension cylinder as shown in FIG. The main body 24 can be raised.

Next, when the innermost kelly bar 18 is hoisted by hoisting the crane hoisting line 6, the engaging element main body 24 ascends in the hanging tube 46, and the tension of the wire rope 37 based on the weight of the hammer grip 26 is doubled. It is remarkably increased by the force device to close both the bucket blades 29a and 29b against the resilience of the compression spring 33 and the hole bottom excavation resistance of the left and right bucket blades with the drilling teeth, and the crane suspension line 6 thereafter. By winding up, the retractable kelly bar 8 is contracted, and the hammer mug is hung up as shown in FIG.

When piercing this operation in reverse, the Hammaglab which is vertically guided by the telescopic kelly bar is shown in FIG.
Boulder K that straddles the inside and outside of the hole D to be drilled like
a, Kb, etc., the lower edge of one of the ordinary drilling teeth, or the lower edge of the non-digging tooth portion of both bucket blades abuts perpendicularly to the upper surface of the boulder, Since the above-mentioned drilling of the bottom of the hole is prevented, it is possible to detect that the boulder was encountered due to the reduction in the amount of drilling chips discharged from the hoisted Hamagrab. Therefore, when the telescopic kelly bar is rotated to a small angle, for example, to the bucket blade center angle θ (see FIG. 8) between adjacent drilling teeth, the hammer blade opened by the bucket blade is dropped by its own weight. If you perform the above-mentioned drilling operation to lift and repeat this drilling operation in a place with a large amount of drilling waste discharged,
Since the space S between the corresponding terminals of the tooth groups of the left and right bucket blades is larger than the length F of each tooth group, some of the boulders are crushed by the tooth and the bottom of the hole is cut by the hammer block. In addition to being dug down as shown by the solid line in the schematic diagram 9, it is dug to some extent below the bottom of the hole by the staggering motion of the drilling teeth when both bucket blades are closed, and the supporting earth pressure in the lower part of the boulder is reduced. Decrease.

If the bottom of the hole is dug down as shown in FIG. 9, it is detected that there is almost no drilling scrap, and after the hammer blade with the bucket blade opened is lowered to the vicinity of the bottom of the hole by the crane, the telescopic kelly bar is removed. While rotating the hammer grab in one direction (for example, the R direction) by the rotary machine 13 while gradually lowering the kelly bar 18 by the crane, the kelly bar 18 is projected by a substantially constant length from the elliptical lower edges of the left and right bucket blades. Of the drill teeth, at least one of the drill teeth 53a, 53b at the lowermost end is rotationally abutted against at least one of the boulders Ka, Kb, etc.-which causes an abnormal noise or a slight impact. If the driving of the rotary machine 13 and the descent of the hammer mug are stopped immediately when a sound or an impact is generated, the crane suspension line 6 remains tense due to the weight of the hammer mag 26 or the like. Because, the engaging element body 24 as shown in FIG. 6
The engaging claw 23 engaged with the
Prevent the descent of 6 due to its own weight.

Therefore, even if the hammer mug is hoisted again by hoisting the crane hoisting rope, the bucket blades 29a, 2
9b maintains an open state, and the rotational angle position of the hammer tab is at least the drilling teeth 53 when it falls by its own weight.
Since the a or 53b is guided by the telescopic Kelly bar 8 so as to collide with boulders, at least one of the vertical drilling teeth will become the weight of the Hammaglab if the Hammaglab is lifted to the required height and then dropped. It is possible to break the boulder (for example, Ka) by the large vertical impact force P based on it, or to gradually roll the boulder toward the center of the hole bottom as shown by the dotted line in FIG. Therefore, the detection of the boulder position due to the above-mentioned abnormal noise and impact, and the weight drop of the Hammaglab against the detected boulder are repeated to crush or break the boulder protruding portion into the hole to be drilled, or the boulder bottom It can be rolled down towards the center and discharged to the ground by a hammer mag.

In order to cope with the loss of the vertical drilling teeth that receive the vertical impact force and the rotational impact force in the horizontal plane as described above, a plurality of sets of excavator units detachably attached to the left and right bucket blades corresponding to each other. When the lower ends of the teeth are located on horizontal planes different in arrangement from the axis of rotation 0 of the Hammaglab and the bottommost drilling teeth 53a and 53b are missing, the drilling teeth on the upper side crush the boulder protruding portion or Although the embodiment configured to break is described, prior to the above-described crushing or breaking operation of the boulder projecting portion, when the bottom of the hole is dug down with a hammer mug as shown by the solid line in FIG. 9, the left and right buckets are used. The present invention also includes this case because it is more effective depending on the geology that only a pair of drill teeth 53a and 53b are attached to the blade.

Further, when the boulders at the bottom of the hole are remarkably large, the teeth 53a, 5 to be dug on the left and right bucket blades 29a, 29b.
While rotating the hammer mub 26 to which 3b is replaceably attached is gradually lowered, the outer peripheral portion of the hole bottom is circularly dug with the boring teeth, and the remaining hole bottom is dug up with the left and right bucket blades, It is possible to pierce by simply lifting the hammer mug and discharging the shavings, but in order to deal with wear and loss of the drilling teeth, the outer walls of the left and right bucket blades that form the vertical cylindrical part when opened are respectively A plurality of vertical drill teeth protruding downward from the elliptical lower edge of the bucket blade at both ends on its diameter line are fixed by exchanging a plurality of sets, and a plurality of drill teeth of the left and right bucket blades when opened. The lower end of the telescopic Kelly bar is prevented from bending or eccentricity by positioning the lower end of the same on the same horizontal plane (H in Fig. 7, for example) to reduce the difference in cutting resistance and rupture resistance between sand gravel and boulder at the hole bottom. Rutotomoni, it is preferable measure to prevent wear and loss of excavation teeth. In this case, since the hammered glove being pierced is supported by the hole bottom through the drilling teeth, the engaging claw 23 and the hanging cylinder 46 of the one-way holding device are switched to the state of FIG. Although the main body 24 can be raised, the left and right bucket blades 29a and 29b are held in the open position in FIG. 4 by the weight of the hammer mug and the elasticity of the spring 33.

In this embodiment, if the leading edge and the lower edge of each removable removable tooth in the direction of rotation of the hanger grab are formed into V-shaped blades, the weight of the hanger grab will cause the gravel layer at the bottom of the hole and the boulder to reach the gravel layer. Although biting can be facilitated and boulder cutting efficiency can be improved, even in the above-described embodiment, if each boring tooth has the same configuration, rotation of the boring tooth in the R direction with respect to the projecting portion of the boulder into the hole to be drilled. Not only assists the fracture of the boulder projecting portion, but also increases the biting force of the boring tooth to the boulder projecting portion by the vertical impact force P to facilitate the fracture of the boulder by the wedge action. It is clear that

[0032]

The boring device of the present invention is coaxially hung and supported at the lower end of the innermost kelly bar of the earth drill through the detachable socket-like engaging elements and the boosters for closing the left and right bucket blades. One or a plurality of diggings configured so that the hammer mug is rotatably driven by the kelly bar, and on the outer walls of the left and right bucket blades that form a vertical cylindrical portion when opened, each vertically protruding below the elliptical lower edge. Since the teeth are fixed by interlocking each other so as to close the hammer mug, the rotary drilling action by the drilling teeth preceding the rotary hammer mag in the open position, which is gradually lowered, and the conventional drilling action by the hammer maglab Join
Even if you can not visually see the boulders that extend inside and outside the hole to be drilled, you can drill while removing the boulder protruding portion into the hole, eliminating the drawbacks of conventional ground drills,
It has the effect of expanding its drilling ability to a stratum with many boulders.

[Brief description of drawings]

FIG. 1 is a vertical side view of the present invention-embodiment.

FIG. 2 is an enlarged cross-sectional view corresponding to the XX cross section of FIG.

FIG. 3 is a side view of an earth drill to which the device of the present invention is attached.

FIG. 4 is a front view in vertical section when the grab bucket is opened.

FIG. 5 is a detailed view of a main part of FIG.

FIG. 6 is a detailed view of a main part of FIG.

FIG. 7 is a view on arrow Z in FIG.

8 is a cross-sectional view taken along line YY of FIG.

FIG. 9 is a vertical sectional front view of a hole bottom portion.

[Explanation of symbols]

1 earth drill 6 crane suspension lines 8 Telescopic Kelly bar 13 Rotary machine 18 Innermost Kelly Bar 23 Engaging claw 24 Engagement body 25 Socket 26 Hammag Love 27 Cylindrical support 29a, 29b bucket blades 46 hanging cylinder 46a protrusion 48 Hammag Love Retaining Ring 48a notch 52a, 52b drilling teeth 53a, 53b drilling teeth 54a, 54b drilling teeth 58 rotary table

Claims (4)

(57) [Claims] 1. An engaging body attached to a lower end of an innermost kelly bar of an extendable kelly bar rotatably supported by a crane rope of an earth drill, and a pair of left and right buckets which are always urged to rotate in an open position. Hammer grabs in which blades are pivoted on both sides of the lower end of a vertical cylindrical support housing, and interlocking connection is made between the engaging element body and left and right bucket blades so that the hammer grabs are closed by gravity action during lifting. A booster in the tubular support casing, a suspension cylinder attached to the upper end of the tubular support casing so that it can slide only within a certain range with the same axis, and the upper end of the suspension cylinder is selectively hung. In order to be able to remove it, only the hammer ring holding ring mounted coaxially with the rotary table on the lower side of the rotary machine of the earth drill, and only the lifting of the engagement body with respect to the hanging cylinder when the hanging cylinder is lifted with respect to the tubular support housing. Always to stop The upper end portion of the tubular support casing is such that the engaging claws that are rotationally biased into the suspension casing can be retracted so that the engaging element main body can be lifted up relative to the suspension pipe when the suspension pipe is lowered relative to the tubular support casing. A Hammaglab punching device for a ground drill, which is equipped with a one-way gripping device attached to a socket-shaped engaging element that is detachably fixed to the lower end of the innermost kelly bar and has an engaging element body provided at the lower end. Regardless of whether it is opened or closed, it is constructed so that it can be slidably fitted in the hanging cylinder at all times, and on the outer wall of the left and right bucket blades that form the vertical cylindrical portion when opened, at both ends on its diameter line, respectively. Vertical boring teeth projecting downward from the elliptical lower edge of the bucket blade are fixed so that the lower ends of the both boring teeth are located on substantially the same horizontal plane, and when the hammer mubs are closed. The teeth are biting each other Hanmagurabu drilling device for earth drilling which is characterized by being configured to. 2. A vertical wall projecting from the outer wall of each of the left and right bucket blades forming a vertical cylindrical portion when opened at a substantially constant length below the elliptical lower edge of the bucket blade at both ends on its diameter line. A plurality of sets of drilling teeth are fixed to form a group of drilling teeth for each of the left and right bucket blades, and the space between the corresponding terminals of the two groups of drilling teeth in the open position is set to be the length of each group of drilling teeth. The hammer drilling device for earth drills according to claim 1, wherein the corresponding drilling teeth of the left and right bucket blades are configured to be inconsistent with each other when the hammer grilles of a larger size are closed. 3. Vertical drilling teeth projecting downward from the elliptical lower edge of the bucket blade at both ends on the diameter line of the outer wall of the left and right bucket blades forming the vertical cylindrical portion when opened. By fixing a plurality of sets, the lower ends of the plurality of sets of drilling teeth of the left and right bucket blades when opened are located on the same horizontal plane, and the corresponding drilling teeth of both bucket blades are inconsistent with each other when the hammer rack is closed. The hammer mag drilling device for an earth drill according to claim 1, wherein 4. A front edge and a lower edge in the direction of rotation of the hammers of each of the drill teeth detachably attached to the left and right bucket blades are V-shaped blades, respectively. A hammer drilling device for a ground drill according to claim 2 or claim 3.