WO2012036524A2

WO2012036524A2 - Rock cutting apparatus using water jet and rock cutting method using the same

Info

Publication number: WO2012036524A2
Application number: PCT/KR2011/006886
Authority: WO
Inventors: Jeong-Gyu Kim; Jae-Joon Song; Young-Il Yoo
Original assignee: GUNWOO TECH CO LTD
Current assignee: GUNWOO TECH CO LTD
Priority date: 2010-09-17
Filing date: 2011-09-16
Publication date: 2012-03-22
Anticipated expiration: 2013-03-17
Also published as: WO2012036524A3; KR101056517B1

Abstract

A rock cutting apparatus includes a shaft having a hollow therein where high-pressure water is movable, the shaft being configured to be inserted into a hole, a moving unit for forcing the shaft to reciprocate, and a nozzle unit installed at a front end of the shaft to inject the high-pressure water moving through the shaft. The nozzle unit injects the high-pressure water to cut a rock around the hole so that the hole communicates with a neighboring hole. Therefore, a cut surface or line is formed before blasting, which reduces blasting vibration transferred to the outside and minimizes overbreak.

Description

ROCK CUTTING APPARATUS USING WATER JET AND ROCK CUTTING METHOD USING THE SAME

The present disclosure relates to a rock cutting apparatus and method, and more particularly, to a rock cutting apparatus and method which cuts a rock around holes formed therein by using water jet so that adjacent holes communicate with each other, and which forms a cut surface (or, a cut line) in advance before blasting to reduce blasting vibration transferred to the outside and minimize overbreak.

Cross-Reference to Related Application

This application claims priority to Korean Patent Application No. 10-2010-0091946 filed in the Republic of Korea on September 17, 2010, the entire contents of which are incorporated herein by reference.

In recent days, a blast method is widely used to dig a tunnel, construct an underground space or cut a slope. The blast method causes blasting vibration and noise since an explosive is used for digging a rock, which may damage neighboring buildings and result in civil complaint.

In order to reduce damage of neighboring buildings and civil complaints, various blast methods capable of reducing blasting vibration and noise have been developed, but any one of them does not give a competent result.

Meanwhile, the water jet technology forms a high-speed water stream by forcing high-pressure water discharged from an ultra-high pressure pump to flow through a nozzle, and the high-speed water stream is appropriately used for its purpose.

Such water jet has been used in a cutting and processing work for cutting or perforating various materials such as metal and plastic, a cleaning work for removing rust or attachments on a coating or metal surface, or the like. In recent days, the water jet is also used in medical fields for eyeball surgery, teeth cleaning or the like.

The present disclosure is designed to solve the problems of the prior art, and therefore the present disclosure is directed to provide a rock cutting apparatus and method, which may cut a rock around holes formed therein by using water jet so that adjacent holes communicate with each other.

The present disclosure is also directed to providing a rock cutting apparatus and method, which may form a cut surface (or, a cut line) in advance before blasting to reduce blasting vibration transferred to the outside, reduce the growth of cracks, minimize overbreak, minimize the danger of collapse due to the absence of relaxation of the rock caused by blasting, and reduce an amount of supporting and reinforcing material used for reinforcing the rock after blasting.

The present disclosure is also directed to providing a rock cutting apparatus and method, which may enable to blast a rock even though the rock is located near an important building or dwellings.

The present disclosure is also directed to providing a rock cutting apparatus and method, which may form various and safe driving sections in mechanical aspects.

In one aspect, a rock cutting apparatus according to an embodiment of the present disclosure includes a shaft having a hollow therein where high-pressure water is movable, the shaft being configured to be inserted into a hole; a moving unit for forcing the shaft to reciprocate; and a nozzle unit installed at a front end of the shaft to inject the high-pressure water moving through the shaft, wherein the nozzle unit injects the high-pressure water to cut a rock around the hole so that the hole communicates with a neighboring hole.

The nozzle unit may inject the high-pressure water to cut the rock while the shaft moves forwards or rearwards in the hole by the moving unit.

The rock cutting apparatus according to an embodiment of the present disclosure may further include a rotating unit for rotating the shaft, wherein the nozzle unit may include a body installed to connect to the shaft and rotate together with the shaft, the body having a path therein where the high-pressure water moves; and an injection hole formed in the body to communicate with the path and allowing the high-pressure water to be injected outwards, wherein, when the shaft is rotated by a predetermined angle by the rotating unit, the injecting direction of the high-pressure water injected from the injection hole changes by a predetermined angle to adjust a cutting direction.

Two injection holes may be formed in the body to have a predetermined angle.

The high-pressure water may be mixed with an abrasive.

In another aspect, a rock cutting method according to an embodiment of the present disclosure includes (a) forming a plurality of holes in a rock; (b) inserting a shaft into one of the holes; and (c) after the step (b), moving a nozzle unit forwards or rearwards while supplying high-pressure water through the shaft so that the high-pressure water is injected through the nozzle unit, thereby cutting the rock around the hole, wherein the cutting work of the step (c) makes the hole to communicate with a neighboring hole.

The high-pressure water may be mixed with an abrasive.

The rock cutting method according to an embodiment of the present disclosure may further include (d) rotating the shaft by a predetermined angle so that an injecting angle of the high-pressure water injected through the nozzle unit changes by a predetermined angle.

In the step (a), the plurality of holes may be formed along a rim portion of the rock to be blasted, and the holes in the rim portion may communicate with each other by the cutting work of the step (c), and, during blasting, blasting vibration transferred to outer portions of the rock to be blasted may be reduced as the holes in the rim portion communicate with each other.

The rock cutting apparatus and method according to the present disclosure give the following effects.

First, since a rock is cut around holes formed therein by using water jet, adjacent holes communicate with each other.

Second, since a cut surface (or a cut line) is formed in advance before blasting, it is possible to reduce blasting vibration transferred to the outside, reduce the growth of cracks, minimize overbreak, minimize the danger of collapse due to the absence of relaxation of the rock caused by blasting, and reduce an amount of supporting and reinforcing material used for reinforcing the rock after blasting.

Third, even though a rock is located near an important building or dwellings, the rock may be blasted.

Fourth, it is possible to form various and safe driving sections in mechanical aspects.

Other objects and aspects of the present disclosure will become apparent from the following descriptions of the embodiments with reference to the accompanying drawings in which:

Fig. 1 is a perspective view showing a rock cutting apparatus according to a preferred embodiment of the present disclosure;

Fig. 2 is a front view showing the rock cutting apparatus of Fig. 1;

Fig. 3 is an enlarged view showing a frame, a shaft, and a rotating unit provided to the rock cutting apparatus of Fig. 1;

Fig. 4 is a cross-sectional view showing a nozzle unit provided to the rock cutting apparatus of Fig. 1;

Fig. 5 is a cross-sectional view showing the rotating unit of Fig. 3;

Fig. 6 is a front view showing a hole formed in an end surface of a tunnel;

Figs. 7a and 7b are cross-sectional views for illustrating that the rock cutting apparatus of Fig. 1 is inserted into the hole and cuts the rock; and

Fig. 8 is a front view showing that the holes of Fig. 6 communicate with each other by using the rock cutting apparatus of Fig. 1.

Reference Symbols

20: shaft 30: nozzle unit

40: rotating unit 100: rock cutting apparatus

Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Prior to the description, it should be understood that the terms used in the specification and the appended claims should not be construed as limited to general and dictionary meanings, but interpreted based on the meanings and concepts corresponding to technical aspects of the present disclosure on the basis of the principle that the inventor is allowed to define terms appropriately for the best explanation. Therefore, the description proposed herein is just a preferable example for the purpose of illustrations only, not intended to limit the scope of the disclosure, so it should be understood that other equivalents and modifications could be made thereto without departing from the spirit and scope of the disclosure.

Fig. 1 is a perspective view showing a rock cutting apparatus according to a preferred embodiment of the present disclosure, and Fig. 2 is a front view showing the rock cutting apparatus.

Referring to Figs. 1 and 2, the rock cutting apparatus 100 includes a moving unit, a shaft 20 reciprocating by the moving unit, a nozzle unit 30 installed at the front end of the shaft 20 to inject high-pressure water to a rock, a rotating unit 40 rotating the shaft 20, and a high-pressure water supplying unit (not shown) supplying the high-pressure water to the shaft 20.

The moving unit forces the shaft 20 to reciprocate with respect to a hole H (see Figs. 6 to 8). The moving unit forces the shaft 20 to move forward and be inserted into the hole H, and after being inserted, the shaft 20 is moved rearward and forward so that the shaft 20 moves in the hole H, as described in detail later.

The moving unit may include a rail 11, a frame 13 installed to the rail 11 to reciprocate, and a driving means for giving a driving force so that the frame 13 may move.

As shown in Fig. 3, the rail 11 has protrusive lines 12 formed at both sides thereof along its length direction. The protrusive lines 12 are coupled to

protrusive portions

15 and 16 of a wheel 14 so that the wheel 14 may be stably moved.

The shaft 20 and the rotating unit 40 are loaded on the upper surface of the frame 13, and the frame 13 reciprocates along the rail 11 by the driving force provided from the driving means. The wheel 14 is installed to the lower portion of the frame 13.

A through hole 17 is formed in the frame 13 to penetrate the frame 13 in the length direction of the rail 11. A thread to be engaged with a thread formed on the outer circumference of a screw 18 is formed on the inner circumference of the through hole 17. Therefore, if the screw 18 rotates in a clockwise or counterclockwise direction, the frame 13 moves forward or rearward according to the rotating direction of the screw 18.

The wheel 14 is rotatably installed to the lower portion of the frame 13. An upper protrusive portion 15 and a lower protrusive portion 16 are formed at the circumference of the wheel 14, and a protrusive line 12 is inserted between the upper protrusive portion 15 and the lower protrusive portion 16 so that the wheel 14 may stably move along the protrusive line 12.

The driving means gives a driving force so that the frame 13 may move along the rail 11. The driving means may include a driving motor 19, and a screw 18 rotating in a clockwise or counterclockwise direction by the driving motor 19.

The driving motor 19 rotates in a clockwise or counterclockwise direction according to the signal input through a manipulation unit (not shown), and the screw 18 rotates in a clockwise or counterclockwise direction according to the rotating direction of the driving motor 19. The frame 13 moves forward or rearward according to the rotating direction of the screw 18. Here, for example, if the screw 18 moves in a clockwise direction, the frame 13 moves forward, and if the screw 18 rotates in a counterclockwise direction, the frame 13 moves rearwards.

Meanwhile, the driving means of the present disclosure may have a modified configuration (structure) if it may give a driving force to the frame 13 so that the frame 13 may reciprocate. For example, the driving means may have a motor directly installed to the wheel 14.

The shaft 20 is installed to the frame 13 and reciprocates together with the frame 13. As shown in Fig. 4, a hollow 21 in which high-pressure water may move is formed in the shaft 20 along the length direction of the shaft 20. A nozzle unit 30 is installed at the front end of the shaft 20, and a rotating unit 40 is installed to the rear end of the shaft 20.

Meanwhile, a guide member 23 is installed at the end of the rail 11 in order to support the shaft 20. A through hole through which the shaft 20 may pass is formed in the guide member 23, and the shaft 20 is guided and supported by the through hole to make forward or rearward movement or rotation.

The nozzle unit 30 includes a body 31 installed to connect to the shaft 20, and an injection hole 35 formed in the body 31 to inject the high-pressure water outwards.

The body 31 is installed to connect to the shaft 20 and rotates together with the shaft 20, and a path 32 along which the high-pressure water moves is formed therein. The path 32 communicates with the hollow 21.

The injection hole 35 is formed in the body 31 to communicate with the path 32. An orifice 36 and a plug 37 fixing the orifice 36 to the injection hole 35 are installed to the injection hole 35. The orifice 36 plays a role of injecting the high-pressure water at a high speed. The orifice 36 is preferably made of cemented carbide or the like so as to endure the high pressure of the high-pressure water. A thread is formed on the outer circumference of the plug 37, and the thread is screwed with the thread formed on the inner circumference of the injection hole 35 to fix the plug 37 to the injection hole 35.

The high-pressure water injected from the injection hole 35 cuts a rock. Therefore, the location and number of injection hole 35 may be determined depending on the cutting pattern. Preferably, two injection holes 35 are formed at a side of the body 31, and two injection holes 35 are formed at a side opposite to the side. In other words, two injection holes 35 are preferably formed to have an angle of 180 degrees based on the body 31, which allows the rock to be cut simultaneously at both sides of the hole H.

Meanwhile, a discharge hole 34 is formed at the connection portion of the shaft 20 and the body 31. The discharge hole 34 discharges the water leaking at the connection portion so that the leaking water does not have a high pressure.

The rotating unit 40 connects a hose 51 supplying the high-pressure water to the shaft 20, and selectively rotates the shaft 20. In other words, the rotating unit 40 connects the fixed hose 51 and the rotatable shaft 20 with each other not to cause leakage and selectively rotates the shaft 20.

The rotating unit 40 includes a first connector 41 to which the hose 51 is connected, a second connector 45 coupled with the first connector 41, a bearing 48 and

lip seals

49a and 49b installed at the circumference of the shaft 20, a first gear 57 installed at the circumference of the shaft 20, a second gear 58 installed to be engaged with the first gear 57, and a rotating motor 59 rotating the second gear 58.

A first inner hollow formed through the first connector 41 is formed in the first connector 41, and the high-pressure water introduced from the hose 51 moves to the shaft 20 through the first inner hollow. An adaptor 42 for coupling the hose 51 is installed at one end of the first connector 41, and a spring 43 and a first connection tube 44a are installed at the other end of the first connector 41.

The adaptor 42 is commonly used for connecting a hose or the like and easily available from the market, and therefore it is not described in detail here.

The spring 43 is supported by a projection 43a formed in the first inner hollow to play a role of pushing (or, biasing) the first connection tube 44a toward the second connection tube 44b so that the first connection tube 44a and the second connection tube 44b are closely adhered to each other. An O-ring 46a for preventing leakage of the high-pressure water may be installed at the outer circumference of the first connection tube 44a.

A second inner hollow is formed in the second connector 45 in the length direction thereof. The first connector 41 is inserted and coupled in one side of the second inner hollow, and the shaft 20 is inserted into the other side of the second inner hollow to be rotatable.

A second connection tube 44b is installed at the rear end of the shaft 20 to communicate with the first connection tube 44a. The high-pressure water moves through the inside of the first and

second connection tubes

44a and 44b. The first connection tube 44a and the second connection tube 44b contact each other, and since the spring 43 pushes the first connection tube 44a toward the second connection tube 44b, the first and

second connection tubes

44a and 44b may be closely adhered to each other, thereby minimizing the leakage of the high-pressure water. An O-ring 46b for preventing leakage may be installed to the outer circumference of the second connection tube 44b.

The second connection tube 44b rotates in a state where the first and

second connection tubes

44a and 44b contact each other, which may easily cause abrasion. For this reason the first and

second connection tubes

44a and 44b are preferably made of cemented carbide or the like with excellent abrasion resistance.

The bearing 48 and the lip seals 49a and 49b are installed to the outer circumference of the shaft 20 and fixed to the second connector 45 so that the shaft 20 may rotate. The bearing 48 may adopt a ball bearing. The lip seal 49a is installed to be fixed to the first connector 41 at the upper portion of the bearing 48, and the lip seal 49b is installed to be fixed to the second connector 45 at the lower portion of the bearing 48. The lip seals 49a and 49b are closely adhered to the outer circumference of the shaft 20 to prevent leakage and allow the shaft 20 to be rotatable. The

lip seal

49a and 49b are widely used for preventing leakage of a fluid and easily available from the market, and therefore their structure is not described in detail here.

The first gear 57 is installed to the outer circumference of the shaft 20. The first gear 57 is rotated by a driving force transmitted from the second gear 58 so that the shaft 20 rotates. The second gear 58 is rotated by the rotating motor 59. Though it is depicted in the figures that the first gear shaft (namely, the shaft 20) and the second gear shaft are perpendicular to each other so that the first gear 57 adopts a worm wheel gear and the second gear 58 adopts a worm gear, the configuration for transmitting the rotating force of the rotating motor 59 to the shaft 20 may be realized in various ways, as easily understood from the present disclosure by those having ordinary skill in the art.

The rotating motor 59 may adopt various kinds of motors, and a hydraulic motor is preferred. In the figures, the reference symbol 52 represents a hose for supplying oil to the rotating motor 59, and the reference symbol 53 represents a hose for discharging oil from the rotating motor 59.

The high-pressure water supplying unit (not shown) gives high pressure to water by using a pump (not shown) and supplies the high-pressure water to the shaft 20 through the hose 51. The high-pressure water has a high pressure capable of cutting a rock, for example 2,000 bar, and the pump supplies a flow rate capable of cutting a rock, for example 9.7 liter/min or 26.8 liter/min.

Though the high-pressure water is composed of only water, an abrasive may be included therein in order to enhance a cutting efficiency. The abrasive may adopt Garnet 0.15~0.30 or the like.

Now, a rock cutting method using the rock cutting apparatus 100 will be described.

First, as shown in Fig. 6, holes H are formed along a rim of a rock R which will be blasted.

Subsequently, the driving motor 19 is operated to move the frame 13 toward the holes H and inserts the nozzle unit 30 to the bottom of the hole H. After the insertion, as shown in Fig. 7a, the high-pressure water is supplied so that the high-pressure water injected from the nozzle unit 30 cuts the rock, and simultaneously the driving motor 19 is operated reversely to move the frame 13 rearwards. The frame 13 preferably moves rearwards till the entrance of the hole H, and accordingly the rock is cut from the bottom to the entrance of the hole. In Fig. 6, the region indicated by C represents a region cut by the high-pressure water, and W represents the high-pressure water injected from the nozzle unit 30.

At this time, since the injection holes 35 of the nozzle unit 30 are formed at opposite sides of the body 31, the water injected through the injection holes 35 cuts the rock at both sides of the hole H.

After the hole H is completely cut, as shown in Fig. 7b, the nozzle unit 30 is inserted into a neighboring hole and the above process is repeated. If the rock around the hole H is cut, the hole H becomes communicating with a neighboring hole H. Fig. 8 shows that neighboring holes H communicate with each other by repeating the above process.

In the above cutting process, the shaft 20 is rotated by a predetermined angle according to the angle formed by neighboring holes H. For example, in a case where neighboring holes H are parallel to each other, the shaft 20 is rotated by a predetermined angle so that two injection holes 35 become parallel to each other. In a case where neighboring holes H are perpendicular to each other, the shaft 20 is rotated by a predetermined angle so that two injection holes 35 become perpendicular to each other. The shaft 20 is rotated by the rotating unit 40.

Meanwhile, though it has been described that the rock is cut while the nozzle unit 30 moves rearwards from the bottom of the hole H to the entrance, it is also possible that the rock is cut while the nozzle unit 30 moves forwards from the entrance of the hole H to the bottom. This will not be described in detail here since it may be easily understood from the present disclosure by those having ordinary skill in the art.

If the rock is completely cut, the rock R is blasted. At this time, since the holes H formed along the rim of the rock R to be blasted communicate with each other to form a cut surface (a cut line) in advance, it is possible to reduce blasting vibration transferred to outer portions of the rock, reduce the growth of cracks, reduce the influence on neighboring buildings, and reduce civil complaints.

In addition, since the cut surface (cut line) formed by the rock cutting apparatus 100 is smooth, it is possible to substantially eliminate overbreak and reduce relaxation of the rock, which allows an amount of supporting and reinforcing material to be reduced. Though an existing pre-splitting method uses blasting to form the cut surface (cut line), the rock cutting apparatus 100 and method according to the present disclosure may obtain more smooth cut surface since water jet is used.

In addition, various driving sections, which may not be obtained by existing methods, may be formed by forming the injection holes 35 at various locations and rotating the shaft 20 to adjust the direction of the high-pressure water injected from the injection holes.

Claims

A rock cutting apparatus, comprising:

a shaft having a hollow therein where high-pressure water is movable, the shaft being configured to be inserted into a hole;

a moving unit for forcing the shaft to reciprocate; and

a nozzle unit installed at a front end of the shaft to inject the high-pressure water moving through the shaft,

wherein the nozzle unit injects the high-pressure water to cut a rock around the hole so that the hole communicates with a neighboring hole.
The rock cutting apparatus according to claim 1, wherein the nozzle unit injects the high-pressure water to cut the rock while the shaft moves forwards or rearwards in the hole by the moving unit.
The rock cutting apparatus according to claim 1, further comprising a rotating unit for rotating the shaft,

wherein the nozzle unit includes:

a body installed to connect to the shaft and rotate together with the shaft, the body having a path therein where the high-pressure water moves; and

an injection hole formed in the body to communicate with the path and allowing the high-pressure water to be injected outwards,

wherein, when the shaft is rotated by a predetermined angle by the rotating unit, the injecting direction of the high-pressure water injected from the injection hole changes by a predetermined angle to adjust a cutting direction.
The rock cutting apparatus according to claim 3, wherein two injection holes are formed in the body to have a predetermined angle.
The rock cutting apparatus according to any one of claims 1 to 4, wherein the high-pressure water is mixed with an abrasive.
A rock cutting method, comprising:

(a) forming a plurality of holes in a rock;

(b) inserting a shaft into one of the holes; and

(c) after the step (b), moving the shaft forwards or rearwards while supplying high-pressure water through the shaft so that the high-pressure water is injected through a nozzle unit, thereby cutting the rock around the hole,

wherein the cutting work of the step (c) makes the hole to communicate with a neighboring hole.
The rock cutting method according to claim 6, wherein the high-pressure water is mixed with an abrasive.
The rock cutting method according to claim 6, further comprising:

(d) rotating the shaft by a predetermined angle so that an injecting angle of the high-pressure water injected through the nozzle unit changes by a predetermined angle.
The rock cutting method according to any one of claims 6 to 8,

wherein, in the step (a), the plurality of holes are formed along a rim portion of the rock to be blasted, and the holes in the rim portion communicate with each other by the cutting work of the step (c), and

wherein, during blasting, blasting vibration transferred to outer portions of the rock to be blasted is reduced as the holes in the rim portion communicate with each other.