JP3857252B2 - Drilling hole expansion bit structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a structure of a drilling hole expansion bit that expands a drilling hole larger than the diameter of a hammer bit that drills a drilling hole when developing groundwater or performing construction and civil engineering. This is an improvement of Korean Patent Registration No. 309297 previously registered by the applicant of the present application.
[0002]
[Prior art]
Due to its structural characteristics, the drilling hole expansion bit is generally configured such that the expansion bit is eccentric from the concentricity of the bit housing, and can be rotated by the bit housing. Similarly, concentricity is eccentric.
[0003]
By the way, a locking projection for rotating the extension bit is formed on the bottom surface of the bit housing of the previously registered patent, and a locking projection is also formed on the upper surface of the extension bit so that it can be hooked and rotated. Yes.
[0004]
However, the locking protrusions formed on the bit housing and the extension bit of the previously registered patent create a space between the bit housing and the extension bit, and the bit housing and the extension bit that operate deep in the ground. The problem is that impurities such as soil and stone powder get caught in between, and such a problem can interfere with the rotation operation of the expansion bit and take out the expensive hammer bit deep in the ground It raises the problem of not.
[0005]
Moreover, since the locking projections of the bit housing and the extension bit that are formed to project from the contact surface in the vertical direction are formed so as to project opposite to each other, the impact generated during excavation is very weak to the impact. This causes a problem that the locking projection breaks, and this problem causes the problem that the hammer bit cannot be taken out from the ground as described above, which extends the construction period and, in particular, civil engineering work due to such loss. There is a problem that the cost is greatly increased.
[0006]
Unlike the conventionally known hammer bit, the structure of a drill hole expansion bit that is generally practiced also has a feature that a steel pipe is buried in the drill hole at the same time as drilling. The expansion bit starts excavation work in a steel pipe buried underground, and the excavation hole expansion bit is expanded at the same time as it digs down the formation while being driven by the lower end of the steel pipe. The steel pipe enters the depth of the drilled bit at the same time, and after the excavation work in such a state is completed, the steel pipe is left as it is embedded in the drilling hole and only the extension bit is extracted. become.
[0007]
On the other hand, the reason for configuring the extension bit to be eccentric with respect to the concentricity of the bit housing is that the first is to dig a drilling hole larger than the PHI of a given steel pipe to facilitate the flow of the bit and the steel pipe, Secondly, after digging the drilling hole, the extension bit is configured to be eccentric so that it can be easily removed from the steel tube, and the extension bit configured in this way rotates the bit housing forward. Sometimes, the drill bit is expanded around the pilot bit, and after drilling, if the bit housing is reversely rotated, the steel pipe becomes smaller than the PHI of the steel pipe.
In other words, the eccentric extension bit was excavated in a state where it was expanded by the normal rotation of the bit housing during excavation, and after excavation, the bit housing was reversely rotated to squeeze smaller than the PHI of the steel tube, and the excavation was completed. Later, it is constructed eccentric so that it can be easily removed from the steel tube.
[0008]
However, in the above-mentioned pre-registered patent, impurities such as soil or stone powder are filled in the space formed as the respective locking projections between the bit housing drilled while rotating deep in the ground and the extension bit. When drilling must be reversed after drilling, the rotation bit cannot be concentric with the bit housing, so the diameter of the expansion bit that could not be reversed is out of concentricity. Therefore, it becomes larger than the diameter of the bit housing, and eventually it is caught in the lower part of the steel tube and cannot be pulled out.
[0009]
[Patent Document 1]
Korean Patent Registration No. 309297 [0010]
[Problems to be solved by the invention]
The present invention is a method for solving the problem of the previously registered patent, wherein the bit housing rotates the pilot bit and the pilot bit rotates the extension bit, and the extension bit is hooked on one side of the pilot bit. A guide functioning as a locking bracket to be rotated is formed, and guide grooves having locking projections on both sides at a constant depth and height are formed at about four-sevenths of a part of the inner peripheral surface of the extension bit. When the pilot bit rotates, the locking projection is caught by the guide so that the extension bit can be rotated, and the upper and lower surfaces of the extension bit are in close contact with the entire pilot bit end projection and the entire bottom surface. However, it is provided in order to completely solve the problem of bending or impurities being caught.
[0011]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the expansion bit of the present invention has several pin half grooves (106) formed vertically at equal intervals on the inner peripheral surface thereof, and the bottom surface (108) has no protruding structure. The flat bit housing (100) and the top surface (200a) are in close contact with the bottom surface (108) to rotate and the bottom surface (200b) is in close contact with the top surface of the end protrusion (309) to rotate. The expansion bit (200) is formed flat and has guide grooves (204) having locking projections (205a, 205b) on both sides of the inner peripheral surface, and a pin half groove (302) on the upper peripheral surface. A prevention pin locking groove (304) is formed on both lower surfaces thereof, and a control surface is formed on both surfaces of the upper pipe portion where the end projection (309) and the extension bit coupling portion (303) meet at right angles. Constant with (305a, 305b) The height of the guide (305), characterized by binding structure to form a.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described in detail as follows.
Bit housing 100;
In the bit housing 100, a pilot coupling hole 102 formed in the body 101 is formed so as to be eccentric, and the pin half groove 106 and the horizontal pin holes 105, 105 ′ are perpendicular to the inner peripheral surface of the body 101 at equal intervals. And are formed.
In addition, the pilot coupling hole 102 includes a rotation prevention pin 400 described below, and a separation prevention pin 500 is fitted to couple the pilot bit 300, and between the pilot bit 300 and the bit housing 100, The expansion bit 200 is combined to form a virtual hammer bit.
[0013]
Extension bit 200;
The expansion bit 200 is a driving body that substantially expands a drilling hole by the bit housing 100 and the pilot bit 300, and performs expansion drilling while rotating so as to be eccentric from the concentricity of the pilot bit 300.
The extension bit 200 is formed such that the through hole into which the extension bit coupling portion 303 is fitted is eccentric, and a portion corresponding to about 4/7 of the inner peripheral surface has a certain depth and height. Thus, guide grooves 204 having locking projections 205a and 205b are formed on both sides thereof, and an extended excavation surface 203 into which several carbide bits 700 are driven is formed on one side of the bottom surface.
[0014]
Pilot bit 300;
The pilot bit 300 is formed as a three-stage eccentricity in which the center of the excavation surface 308 and the centers of the extension bit coupling portion 303 and the bit housing coupling portion 301 do not coincide with each other. The pin half groove 302 is formed, and horizontal prevention pin locking grooves 304 are formed on both sides of the lower portion of the pin half groove 302, particularly on the upper pipe line portion that meets the end protrusion 309 on the back surface of one side of the extension bit coupling portion 303. Is formed with a guide 305 of constant thickness, width and height having control surfaces 305a, 305b on both sides.
[0015]
Anti-rotation pin 400;
The anti-rotation pin 400 is a function of a control key that prevents the pilot bit 300 from spinning around in the bit housing 100 by being engaged with and fitted into each of the pin half grooves 106 and 302 formed as half grooves. Fulfill.
[0016]
Anti-separation pin 500;
As shown in FIGS. 1 and 2, the separation preventing pin 500 is fitted in the bearing half grooves 104 and 304 between the bit housing 100 and the pilot bit 300 to couple the pilot bit 300 and the bit housing 100 together.
In other words, the extension bit 200 is first coupled to the outside of the extension bit coupling unit 303 from the top to the bottom of the pilot bit 300. At this time, the extension bit 200 coupled to the pilot bit 300 is guided on the inner peripheral surface. The pilot bit 300 is inserted into the groove 204 so that the guide 305 of the pilot bit 300 flows into the groove 204 and is extrapolated to the extension bit coupling portion 301.
[0017]
Next, the upper surface of the extension bit 200 coupled to the outer peripheral surface of the bit housing coupling part 301 is coupled to the outside so that the body 101 of the bit housing 100 is covered. At this time, the pilot bit of the coupled bit housing 100 is coupled. In the state where the rotation preventing pin 400 is fitted in the pin half groove 302 formed on the outer peripheral surface of the bit housing connecting portion 301 on the upper part of the pilot bit 300 in the connecting hole 102, the inner peripheral edge of the pilot bit connecting hole 102 there. The pin half grooves 106 on the surface are aligned, so that both prevention pin locking grooves 304 of the bit housing coupling portion 303 are aligned with the pin holes 105, 105 ′ horizontally penetrating on both sides of the body 101 of the bit housing 100. Thus, the joining work is completed by sandwiching the separation preventing pin 500 in the state of being coincident with each other. Is done.
[0018]
According to the present invention, when the excavation surface 308 comes into contact with the ground while the bit housing 100 is rotating forward, the ground is dug down by friction of the excavation surface 308, and in this process, the position of the end projection 309 of the pilot bit 300 is reached. At that time, the bottom extended excavation surface 203 of the expansion bit 200 comes into contact with the ground, and at the same time, the expansion bit 200 stops when the expansion excavation surface 203 comes into contact with the ground. Since the bit 300 continues to rotate, the guide 305 eventually rotates while receiving the guidance of the guide groove 204 while the vertical control surface 305b on one side is in close contact with the locking projection 205a, and controls on the other side. The surface 305a moves toward the opposite locking projection 205a, and The guide 305 which has been rotated and moved is sometimes brought into close contact with the ground at the moment when its control surface 305a comes into close contact with the locking projection 205a, and the extended extension bit 200 which has been stopped is eccentric from the concentric state while being rotated by the rotating pilot bit 300. The circle is expanded to the state, and a drilling hole wider than the drilling surface 308 can be drilled.
[0019]
On the other hand, after the operation of digging the excavation hole is completed, the bit housing 100 is rotated in the reverse direction. When the bit housing 100 is rotated, the pilot bit 300 and the extension bit 200 are guided in the reverse order as described above. , While being guided by the guide groove 204, the expansion bit 200 that has been excavated from the eccentric state to the concentric state is rotated in the reverse direction.
On the other hand, when the above action occurs, the upper surface 200a of the extension bit 200 is in close contact with the bottom surface 108 of the body 101 without a gap, and the bottom surface 200b is in close contact with the entire surface of the end projection 309. Therefore, even if a rotary excavation operation is performed in a deep place in the ground, a smooth operation is possible without being affected by impurities such as soil and stone powder.
[0020]
【The invention's effect】
As described above, according to the present invention, in the structure in which the locking projections formed in the up-down direction on the extension bit 200 and the bit housing 100 can be engaged with each other to rotate, the protruding locking projections can be removed. In addition, a guide groove 204 having locking projections 205 a and 205 b on both sides is formed on the inner peripheral surface of the extension bit 200, a guide 305 is formed on the pilot bit 300, and the guide 305 guides in the guide groove 204. Since it has been improved so that it can rotate while being received, the problem that the rotation operation is hindered due to impurities such as soil or stone powder is solved, and at the same time, the guide 305 is formed on one side of the pilot bit 300 and the inside of the extension bit 200 Since the guide groove 204 on the peripheral surface rotates while receiving guidance over a large area, the loss due to breakage is maximized. It is a very useful invention that would provide the proof can effectively.
[Brief description of the drawings]
FIG. 1 is a perspective view of a disassembled and coupled state for explaining the structure of the present invention.
2 is a cross-sectional view illustrating the coupled state of FIG. 1;
FIG. 3 is an exemplary view of a bottom surface of an extension bit in the present invention.
4 is an exemplary view of a cross-sectional view taken along line AA in FIG. 3;
[Explanation of symbols]
100 Bit housing 101 Body 102 Pilot bit coupling hole 105, 105 ′ Pin hole 106, 302 Pin half groove 107, 202 Tip discharge groove 200 Expansion bit 203 Expansion excavation surface 204 Guide groove 205 Locking protrusion 300 Pilot bit 301 Bit housing coupling part 303 Extension Bit Coupling Section 304 Prevention Pin Locking Groove 305 Guide 306 Pneumatic Hole 307 Pneumatic Groove 308 Excavation Surface 400 Anti-Rotation Pin 500 Separation Prevention Pin

Claims (2)

A fuselage, and a pilot coupling hole formed from a bottom surface of the fuselage , and
A first pin half groove formed on the inner peripheral surface of the pilot coupling hole
A bit housing having,
A bit housing coupling part fitted into the pilot coupling hole;
An extension bit coupling portion provided in a direction opposite to the bit housing from the bit housing coupling portion,
A guide formed on a side surface of the extension bit coupling portion ;
The bit housing coupling portion and the end impact force provided on the opposite direction from the extension bit coupling portion, and
Second pin half groove formed on the outer peripheral surface of the bit housing coupling portion
And a pilot bit having a,
A driving body that rotates and operates with an upper surface closely contacting the bottom surface of the body of the bit housing and a lower surface closely contacting the upper surface of the end protrusion,
A through hole formed from the lower surface to the upper surface of the driving body and fitted with the extension bit coupling portion;
A guide groove formed on an inner peripheral surface of the through hole and guiding the guide; and formed in the guide groove and transmitting the rotation of the pilot bit to the drive body when the guide comes into close contact with the drive body. An extension bit having a locking projection for rotating
A rotation preventing pin that is half-engaged with the first pin half groove and the second pin half groove to prevent idle rotation of the pilot bit and the bit housing;
Borehole extension bit comprising a.   The bit housing is
  A pin hole formed in the body in a direction perpendicular to the first pin half groove
Further comprising
  The pilot bit is
  Preventing pin locking groove formed in the direction perpendicular to the second pin half groove on the outer peripheral surface of the bit housing coupling portion
Further comprising
  The drilling hole expansion bit is
  An anti-separation pin that is fitted in the pin hole and the prevention pin lock and connects the pilot bit and the bit housing.
The drilling hole expansion bit according to claim 1, further comprising:

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