WO2008136624A2

WO2008136624A2 - Non-oscillatory rock cutting apparatus using hydraulic pressure and method of controlling hydraulic pressure thereof

Info

Publication number: WO2008136624A2
Application number: PCT/KR2008/002517
Authority: WO
Inventors: Sang-Hyu Lee; Tae-Ho Park; Sung-Tae Cho; Jin-Won Lee
Original assignee: Sang-Hyu Lee; Tae-Ho Park; Sung-Tae Cho; Jin-Won Lee
Priority date: 2007-05-08
Filing date: 2008-05-02
Publication date: 2008-11-13
Also published as: WO2008136624A3

Abstract

A non-oscillatory rock cutting apparatus using hydraulic pressure and a method of controlling hydraulic pressure of the same. At least one element producing expansion pressure from pressure of a fed fluid is installed in a hole drilled in rock such that the expansion pressure is applied to the drilled hole by the pressure of the fed fluid. The element includes an internal tube, which encloses the outer circumference of a hydraulic pressure supply pipe, an external tube, which is located around an outer circumference of the internal tube so as to cover at least part of the internal tube, and a fixing unit, which supports the external tube and the internal tube on the hydraulic pressure supply pipe toward opposite ends of the external tube. Thereby, the non- oscillatory rock cutting apparatus using hydraulic pressure expands the internal tube using the pressure of the fluid, thereby cutting the rock without oscillation.

Description

NON-OSCILLATORY ROCK CUTTING APPARATUS USING

HYDRAULIC PRESSURE AND METHOD OF CONTROLLING

HYDRAULIC PRESSURE THEREOF

Technical Field

[1] The present invention relates to a non-oscillatory rock cutting apparatus using hydraulic pressure, in which an internal tube is expanded to cut rock without oscillation when hydraulic pressure is supplied through an internal tube expanded by the hydraulic pressure.

[2] The present invention also relates to a method of controlling the hydraulic pressure of a non-oscillatory rock cutting apparatus, in which, when pressure is applied to one side of a piston by one fluid, another fluid present on the other side of the piston is continuously supplied to a cutter so as to expand an internal tube. Background Art

[3] As is generally known in the art, two methods are used to crush rock. One is conducted by forming at least one blasting hole, filling the blasting hole with a detonating explosive, and blasting the rock, and the other is conducted by manually crushing the rock using chisels according to the characteristics of the rock, such as the characteristics of the beds thereof.

[4] In the former case, in which the detonating explosive is used, a plurality of blasting holes is first drilled into the rock at suitable intervals, and then the detonating explosive is inserted into the blasting holes. The detonating explosive is exploded to crush the rock by means of pressure generated inside the blasting holes.

[5] However, the method of using the detonating explosive has an advantage in that it can easily crush large amounts of rock, but has drawbacks in which it generates a loud explosion noise, entails a high possibility of accidents affecting job safety, and may be conducted only by experts. As such, the method of using the detonating explosive entails various problems and restrictions from the viewpoint of the environment, safety and workability.

[6] Examples capable of overcoming this problem include a wedge type rock crushing machine, a cylinder type rock crushing machine (Korean Patent Application Publication No. 1995-0023831), a split wedge type rock crushing machine, and so on.

[7] In the case of the wedge type rock crushing machine, three wedges are formed as a set. The central wedge thereof is lowered using hydraulic pressure, and the others are pulled upwards. Thereby, force is applied to the rock, and the rock is crushed. Due to the characteristics thereof, in a separate process, oil must be injected in order to reduce the friction against each wedge, and furthermore, strong force must be applied to each wedge. As such, the wedge type rock crushing machine has a very complicated structure, and many operations must be conducted in order to crush the rock.

[8] In the case of the cylinder type rock crushing machine, a plurality of small-sized cylinders, installed on a body in a longitudinal direction, is operated to apply force to the rock. Despite the non-uniform strength of the rock, the cylinders are overstrained, and thus experience frequent damage. As a result, the cylinder type rock crushing machine fails to apply uniform force to the rock, and thus fails to efficiently crush the rock.

[9] Further, in the case of the split wedge type rock crushing machine, a body is divided into four equal segments, and is equipped with a rubber tube therein. The built-in rubber tube is supplied with hydraulic pressure and is thereby expanded. Thereby, the quartered body is pushed out to thus apply force to the rock, thereby crushing the rock. The force applied to the rock is not uniform, and each body segment has the potential to undergo deformation. Furthermore, the split wedge type rock crushing machine has a complicated structure, and thus frequently breaks down during operation.

[10] In order to solve this problem, a rock crushing machine is disclosed in Korean Utility

Model Application Publication No. 1998-20574. As illustrated in FIGS. 1 and 2, the rock crushing machine has a cylindrical shape on the whole, and includes a circular tube 99, forming a central axis, and an elastic tube 98, enclosing the circular tube and expanded by injected oil, wherein the circular tube 99 is screwed with a cap type nut 96, which prevents a cap ring 93 from escaping and has an oil hose connecting tap 95 at an upper end thereof, and has another cap type nut 96, which prevents another cap ring 93 from escaping, at a lower end thereof.

[11] The circular tube 99, forming the central axis, has a plurality of oil supply holes 91 therein and threads 97 at opposite ends thereof. Each oil supply hole 91 supplies oil, which flows from the outside into the circular tube 99, to the elastic tube. Each cap ring 93 includes a through-hole having the same outer diameter as the circular tube 99, and a corrugated part 98 on the inner circumference thereof. The elastic tube 92 is fixed to the circular tube 99 by the corrugated parts 98 of the cap rings, which are inserted through the through-holes thereof, above and below the circular tube 99.

[12] Further, each cap type nut 96 includes the oil hose connecting tap 95, connected with an external oil hose, and internal threads 97. Each cap type nut 96 is screwed with the circular tube 99, in the upper end of which the external threads 97 are formed, thereby supplying the oil from the outside to the circular tube 99, and preventing the corresponding cap ring 93 from escaping from the circular tube 99 when the elastic tube 92 is expanded.

[13] However, this rock crushing machine is configured such that the elastic tube 92 is supported only by a locking step formed on each cap ring 93. Thus, when the pressure is applied to the elastic tube 92, the connection between each cap ring and the elastic tube is easily separated, thus causing the pressure to leak out. As a result, the elastic tube 92 can be expanded. Further, when the diameter of the elastic tube is increased at the moment that the rock is cut, the diameter of each cap ring 93 is not changed, so that a gap occurs due to the difference in diameter between each cap ring and the elastic tube. This gap causes the pressure to be concentrated on the elastic tube 92, so that the elastic tube is easily damaged.

[14] After the rock crushing machine is inserted into the blasting hole of the rock A, the elastic tube 92 is expanded and exposed through a gap defined between the blasting hole and each cap ring 93, so that the pressure is not precisely transmitted to the inside of the blasting hole. In other words, when the elastic tube 92 is expanded, each cap ring is not simultaneously expanded, so that the elastic tube 92 is exposed through the gap defined between the blasting hole and each cap ring, and thus it is difficult to precisely transmit the pressure to the rock.

[15] Further, the elastic tube 92 is largely expanded through the gap, and thus is easily damaged. This deteriorates the reliability of the elastic tube 92.

[16] If the thickness of the elastic tube 92 is increased in order to solve this problem, the thickness of the corrugated part 98 is relatively reduced. Thus, the corrugated part is subjected to the concentration of pressure, thereby suffering an increase in fatigue of the part, thus leading to a decreased lifespan.

[17] Further, there has been proposed a non-oscillatory noiseless rock cutting method using hydraulic pressure. This rock cutting method is adapted to insert a hydraulic rock cutter into a hole drilled in the rock, supply working oil to the hydraulic rock cutter, and raise a piston to cut the rock.

[18] In conjunction with this technology, the rock cutter was disclosed in Korean Patent

No. 287989. As illustrated in FIGS. 3 and 4, the rock cutter includes: a housing 10, which has a plurality of cylinder chambers 11 in the upper surface thereof and first and second passages 14 and 15 in one end face thereof, these passages communicating with the cylinder chambers so as to allow oil to flow in and out; pistons 40, which are fitted in the cylinder chambers 11 of the housing 10 and move up and down according to the inflow and outflow of the oil; a cap 70, which is coupled to an upper portion of the housing 10 so as to be able to move up and down, and moves up and down along with the pistons 40, with an inner surface thereof contacting upper surfaces of the pistons 40; and telescopic members 30, each of which includes a fastening member 31 which is detachably fastened to the piston 40 in the corresponding cylinder chamber 11, and coupling members 32 and 33, which are telescopically coupled inside the fastening member 31 so as to be expanded upwards and contracted downwards and allow the oil to flow through gaps 30a between inner and outer diameters thereof.

[19] In addition to this configuration, the rock cutter includes cylinders 50, each of which is detachably mounted in the corresponding cylinder chamber 11 of the housing 10 in an air-tight state and allows the corresponding piston 40 to move up and down therein. Each telescopic member 30 includes an elastic member 20, which is in contact with the bottom of the corresponding piston 40 so as to provide an elastic supporting force. The fastening member 31 and the coupling members 32 and 33 have a step 31a and steps 32a, 32b and 33a in order to block the gaps 30a therebetween to interrupt the oil.

[20] The cap 70 is provided with guide slots 71 in opposite sidewalls thereof so as to be able to be displaced by the pistons 40. The housing is provided with guide pins 16 so as to be able to slide in the guide slots 71. Each cylinder 50 includes a groove 52 in the outer circumferential surface thereof, and a plurality of oil passages 53 formed in the groove 52 such that the oil supplied from the second passage 15 flows thereinto.

[21] This rock cutter is adapted so that, when the hydraulic pressure is applied inside the cylinder chambers 11 through the passage 14, the telescopic members 30 installed in the respective cylinder chambers 11 move up step by step to thus come into contact with the pistons in respective cylinders 50, and thus raise the pistons.

[22] At this time, the cap 70, which is supported on the pistons 40 and moves up and down along the guide slots 71, is raised to cut the rock.

[23] However, the rock cutter has drawbacks in that the operating members, such as the pistons, the cap, etc. must be made of special steel because they are designed to be operated by hydraulic pressure, thus increasing the cost of production, and in that the lengths of the operating members, such as the pistons, the cap, etc. cannot be changed, and thus the force for cutting the rock (i.e. rock cutting force) is lowered, leading to low working performance and poor economy.

[24] Meanwhile, a hydraulic fracturing apparatus capable of resolving the problems with the rock cutter using hydraulic pressure is disclosed in Korean Patent No. 646584. As illustrated in FIG. 5, the hydraulic fracturing apparatus includes: a hydraulic pressure supply 85, which has opposite closed ends, a hollow cylindrical shape, and a hydraulic nozzle 87 in the middle of the long axis thereof in order to supply fracturing pressure to rock at a desired depth in a borehole; hydraulic fracturing units, which are mounted to the opposite ends of the hydraulic pressure supply 85, have a tube shape, and include respective packers 86 with low-pressure holes 89, a transfer unit, which has a transfer winch 88 around which a transfer rope 88 A is wound in order to transfer the hydraulic fracturing units up to the desired depth in the borehole; a power supply, which receives power from the power output shaft of a vehicle in order to supply low pressure and high pressure to the hydraulic fracturing units, and supplies the received power to a low-pressure compression part 80B connected from a low-pressure line 84 to the packer 86 and to a high-pressure compression part 8OA connected from a high- pressure line 83 to the hydraulic pressure supply 85; and a pressure regulator, which connects high-pressure and low-pressure regulating valves to the high-pressure and low-pressure lines 83 and 84, respectively, using water, and regulates hydraulic pressure.

[25] This hydraulic fracturing apparatus is designed to fracture the rock by expanding the packer 86 to fix the hydraulic pressure supply 85 using the low-pressure compression part, and supplying water to collide with a surface of the rock using the high-pressure compression part.

[26] However, the water must be continuously supplied in order to operate the high- pressure and low-pressure compression parts. Thus, in the case in which a water source is located a long distance away, it is impossible to install the hydraulic fracturing apparatus.

Disclosure of Invention Technical Problem

[27] Accordingly, the present invention has been made in an effort to solve the problems occurring in the related art, and an object of the present invention is to provide a non- oscillatory rock cutting apparatus using hydraulic pressure, capable of supporting the external tube so as to prevent it from separating, rapidly expanding an external tube when pressure is applied to the external tube, preventing the external tube from being incompletely expanded by the expansion pressure of the internal tube, applying the pressure of the internal tube only to the drilled hole of rock, completely preventing the pressure from leaking out when the external tube is expanded, and preventing deformation caused by longitudinal expansion of the external tube.

[28] Another object of the present invention is to provide a non-oscillatory rock cutting apparatus using hydraulic pressure, in which rock is cut without oscillation by simultaneously expanding several internal tubes, which are connected so as to have a long length, using fluid at high pressure, thereby improving working performance to reduce construction expenses, reducing the costs of production of the equipment and the costs of maintenance, preventing problems of noise, vibration, dust, scattering, etc. caused by the explosion of explosives, and providing connection and separation according to the conditions of use to thus overcome restrictions imposed by the surrounding environment.

[29] Another object of the present invention is to provide a non-oscillatory rock cutting apparatus using hydraulic pressure, capable of preventing the pressure of a fluid from doing damage to an internal tube, providing firm rapid assembly, simultaneously expanding several internal tubes, which are connected so as to have a long length, using fluid at high pressure, so as to cut rock without oscillation, and improving working performance to reduce the expenses of construction.

[30] Another object of the present invention is to provide a non-oscillatory rock cutting apparatus using hydraulic pressure, in which the pressure of water is used for final output, thereby enabling the application of a rubber tube, which cannot be applied when hydraulic oil is used, preventing environmental pollution caused by leakage of the oil, securing safety by controlling the hydraulic pressure, and boosting the hydraulic pressure up to a predetermined level to eliminate the inconvenience in which pressure-generating equipment must always be monitored when in use, and in which each hydraulic pressure supply is individually operated, thereby eliminating the possibility of loss of overall pressure caused by damage to the hydraulic pressure supplies to thus permit the complete transmission of pressure. Technical Solution

[31] In order to achieve the above object, according to one aspect of the present invention, there is provided a non-oscillatory rock cutting apparatus using hydraulic pressure, in which at least one element inserted into a drilled hole of rock is adapted so that an internal tube, which can be expanded and contracted according to the pressure of a fluid, is supported with two or more faces thereof at opposite sides of a hydraulic pressure supply pipe through a fixing means to thereby define an air-tight space inside the internal tube, and is expanded to transmit expansion pressure to the inside of the drilled hole when the pressure of the fluid is supplied.

[32] According to one aspect of the present invention, the element includes an internal tube, which encloses the outer circumference of a hydraulic pressure supply pipe, an external tube, which is located around the outer circumference of the internal tube so as to cover at least part of the internal tube, and a fixing unit, which fixes constituent parts to the hydraulic pressure supply pipe such that the constituent parts are sequentially coupled toward opposite ends of the external tube.

[33] Further, according to one aspect of the present invention, caps for fixing the external tube are integrally formed with steps for mounting external tube caps on opposite ends of the external tube having a hollow shape. Each step is integrally formed with a first reinforcing member. The external tube caps, mounted on the steps of the external tube, enclose the steps so that they can be expanded in a diametrical direction.

[34] According to one aspect of the present invention, each external tube cap has an integrally assembled structure comprising: variable blocks, which are opposite each other when installed, and each include a first contact face corresponding to the outer diameter of the external tube at the center thereof, and linear slide faces extending from the first contact face; positioning blocks, which include contact faces cor- responding to the slide faces of the variable blocks, and second contact faces on the inner circumferences thereof so as to correspond to the outer diameter of the external tube, and are formed so as to have gaps between the ends of the opposite variable blocks; and a support member, which is formed so as to enclose at least part of the outer or inner circumferences of the variable blocks and the positioning blocks and to provide predetermined elasticity.

[35] According to another aspect of the present invention, there is provided a method of controlling the hydraulic pressure of a non-oscillatory rock cutting apparatus, which comprises the steps of: supplying pressure of one fluid, which is boosted by each unit pressure boosting unit, to one side of at least one operating cylinder, which is connected to the corresponding unit pressure boosting unit, to thereby operate a piston; feeding another fluid to another side of the piston, the stroke of which is adjusted, so as to have a volume corresponding to the amount of expansion of an internal tube by means of the other fluid; and continuously feeding the other fluid, present on the other side of the piston, to the non-oscillatory rock cutting apparatus when the pressure of one fluid is repeatedly applied to one side of the piston so as to expand an internal tube.

Advantageous Effects

[36] According to the present invention, the non-oscillatory rock cutting apparatus using hydraulic pressure can support the external tube so as not to be separated, rapidly expand an external tube when pressure is applied to the external tube, prevent the external tube from being incompletely expanded by the expansion pressure of the internal tube, apply the pressure of the internal tube only to the drilled hole of rock, completely prevent the pressure from leaking out when the external tube is expanded, and prevent deformation caused by longitudinal expansion of the external tube.

[37] Further, the non-oscillatory rock cutting apparatus using hydraulic pressure cuts the rock without oscillation by simultaneously expanding several internal tubes, which are connected so as to have a long length, using fluid at high pressure, so that it can improve working performance to reduce the expenses of construction, reduce the cost of production of the equipment and the cost of maintenance, remove problems of noise, vibration, dust, scattering, etc. caused by the explosion of explosives, and provide connection and separation according to the conditions of use to minimize the impact of restrictions of the surrounding environment.

[38] In addition, the non-oscillatory rock cutting apparatus using hydraulic pressure makes use of water pressure for final output, so that it can provide the application of a rubber tube, which cannot be applied when hydraulic oil is used, preventing environmental pollution caused by the leakage of oil, secure safety by controlling the hydraulic pressure, and boost the hydraulic pressure up to a predetermined level to eliminate the inconvenience in which pressure-generating equipment must always be monitored when in use. In the non-oscillatory rock cutting apparatus using hydraulic pressure, each hydraulic pressure supply is individually operated, so that it can eliminate the possibility of loss of overall pressure caused by damage to the individual hydraulic pressure supplies to thus permit the accurate transmission of pressure. Brief Description of the Drawings

[39] FIGS. 1 and 2 are an exploded view and an operational view illustrating a conventional rock crushing machine, respectively;

[40] FIG. 3 and 4 are cross-sectional views illustrating a conventional non-oscillatory noiseless rock cutter;

[41] FIG. 5 illustrates the operation of a conventional rock crushing machine;

[42] FIG. 6 is a perspective view illustrating a non-oscillatory rock cutting apparatus using hydraulic pressure according to the present invention;

[43] FIG. 7 is a cross-sectional view illustrating a non-oscillatory rock cutting apparatus using hydraulic pressure according to the present invention;

[44] FIG. 8 is an exploded cross-sectional view illustrating a non-oscillatory rock cutting apparatus using hydraulic pressure according to the present invention;

[45] FIG. 9 is a projection view illustrating a non-oscillatory rock cutting apparatus using hydraulic pressure according to the present invention;

[46] FIGS. 10 through 12 are cross-sectional views illustrating the application of a non- oscillatory rock cutting apparatus using hydraulic pressure according to the present invention;

[47] FIG. 13 is a perspective view illustrating a non-oscillatory rock cutting apparatus using hydraulic pressure according to another embodiment of the present invention;

[48] FIGS. 14 and 15 are an exploded perspective view and an exploded cross-sectional view of FIG. 13;

[49] FIG. 16 is an assembled cross-sectional view of FIG. 13;

[50] FIG. 17 is a perspective view illustrating an external tube applied to a non-oscillatory rock cutting apparatus according to the present invention;

[51] FIG. 18 is a perspective view illustrating an external tube according to another embodiment of the present invention;

[52] FIGS. 19 through 22 are cross-sectional views illustrating examples of an external tube cap mounted on an external tube;

[53] FIGS. 23 and 24 are exploded views illustrating an external tube gap applied to an external tube according to another embodiment of the present invention;

[54] FIG. 25 is a cross-sectional view illustrating the state in which an external tube gap is mounted on an external tube according to another embodiment of the present invention;

[55] FIGS. 26 and 27 are cross-sectional views illustrating an external tube gap according to another embodiment of the present invention;

[56] FIG. 28 is a cross-sectional view illustrating the operation of an external tube gap according to another embodiment of the present invention;

[57] FIGS. 29 and 30 are a circuit diagram and a detailed connection diagram illustrating an apparatus for controlling hydraulic pressure according to an embodiment of the present invention;

[58] FIGS. 31 and 32 are detailed cross-sectional views illustrating an operating cylinder applied to an apparatus for controlling hydraulic pressure according to an embodiment of the present invention;

[59] FIGS. 33 and 34 are a circuit diagram and a detailed connection diagram illustrating an apparatus for controlling hydraulic pressure according to another embodiment of the present invention;

[60] FIG. 35 is a connection diagram illustrating an apparatus for controlling hydraulic pressure according to another embodiment of the present invention; and

[61] FIG. 36 is a detailed cross-sectional view illustrating an operating cylinder applied to an apparatus for controlling hydraulic pressure according to another embodiment of the present invention. Best Mode for Carrying Out the Invention

[62] Reference will now be made in greater detail to an exemplary embodiment of the invention, an example of which is illustrated in the accompanying drawings.

[63] FIG. 6 is a perspective view illustrating a non-oscillatory rock cutting apparatus using hydraulic pressure according to the present invention. FIG. 7 is a cross-sectional view illustrating a non-oscillatory rock cutting apparatus using hydraulic pressure according to the present invention. FIG. 8 is an exploded cross-sectional view illustrating a non-oscillatory rock cutting apparatus using hydraulic pressure according to the present invention. FIG. 9 is a projection view illustrating a non-oscillatory rock cutting apparatus using hydraulic pressure according to the present invention. FIGS. 10 through 12 are cross-sectional views illustrating the application of a non-oscillatory rock cutting apparatus using hydraulic pressure according to the present invention.

[64] An element 100 used for the non-oscillatory rock cutting apparatus using hydraulic pressure according to the present invention comprises a hydraulic pressure supply pipe 110, which is constituted of a main line 111 and a plurality of branch lines 113 branching off from the main line 111, an internal tube 130 fitted around the outer circumference of the hydraulic pressure supply pipe 110, and fixing means 150 supporting either end of the internal tube 130 with two or more faces thereof to define an air-tight space inside the internal tube.

[65] Each of the fixing means 150 includes a connecting rod 151, which is connected to the hydraulic pressure supply pipe 110 and geometrically brings either end of the internal tube into close contact with the two or more faces thereof, a first fixing unit 153-1, which is provided on the outer circumference of the connecting rod so as to cause frictional force against one face of the connecting rod, and a second fixing unit 155-1, which is installed so as to cause frictional force against the other face of the connecting rod.

[66] At this time, the first fixing unit 153-1 and the second fixing unit 155-1 respectively come into close contact with first and second close contact faces A and B of the connecting rod when first and second actuating units 153 and 155, screwed to the connecting rod, are turned, so as to adjust the closeness of contact thereof.

[67] In addition, the first fixing unit 153-1 is connected with an external tube 170, which can be expanded beyond predetermined strength.

[68] Meanwhile, the element 100 is constructed so that the hydraulic pressure supply pipe

110 having a predetermined length is enclosed by the internal tube 130, and is provided with the fixing means 150 on the opposite sides thereof.

[69] Continuously, the element 100 is coupled with another identical element 100 through a connecting joint 200. The connecting joint 200 is provided with screw threads having different turning directions so as to fasten the hydraulic pressure supply pipes 110 on opposite sides thereof when turned, and includes a valve opener 210 on the inner diameter side thereof so as to open a check valve 180 provided to the hydraulic pressure supply pipe 110.

[70] The hydraulic pressure supply pipe 110 is provided with sealing bolts 353 at opposite ends thereof so as to prevent the pressure from leaking out, and a front cap 351 and a rear cap 355 for protecting the sealing bolt 353 and the second actuating unit 153. The element 100 additionally includes a handle 357 coupled to the rear cap 355 for the purpose of movement (to another place).

[71] Further, the elements 100 are coaxially interconnected by length extension units 300, each of which is provided with the connecting rods 151 at respective opposite ends thereof, and on which first and second fixing units and actuating units are connected to the first and second fixing units.

[72] Now, the operation of the element, which is configured as described above and is used for the non-oscillatory rock cutting apparatus of the present invention, will be described.

[73] As illustrated in FIGS. 6 through 12, the present invention is designed so that, when the pressure of a fluid, increased up to a predetermined level by a hydraulic pressure controller O, which well be described below, is transmitted through the hydraulic pressure supply pipe 110, the pressure of the fluid flowing along the main line 111 is transmitted to the bypass lines 113.

[74] The pressure of the fluid transmitted to the bypass lines 113 is applied to the internal tube 130, which encloses the outer circumference of the hydraulic pressure supply pipe 110 and is in close contact with the fixing means 150 at the opposite ends thereof, thereby expanding the internal tube.

[75] At this time, the internal tube, expanded in this way, is expanded while being inserted in a drilled hole IOOA of the rock, so that the pressure of the fluid is transmitted to the rock, thereby cutting the rock.

[76] Here, it does not matter that the entire internal tube 130 is expanded. However, since the internal tube 130 is mounted in the separate external tubes 170, which are supported by the fixing means 150, it concentrates the expansion pressure, and minimizes damage caused by the hole drilled in the rock.

[77] Further, the element 100 may have either a plurality of internal tubes 130 or only a single internal tube 130, which encloses the hydraulic pressure supply pipe 110 having a predetermined length.

[78] In addition, the element 100 may be used simultaneously together with the other identical elements 100 connected via the connecting joints 200.

[79] Meanwhile, the connecting joint 200 is provided with the valve opener 210 on the inner diameter side thereof, and is adapted to open the check valves 180 on inner diameter sides of the opposite ends of each element 100 when it is turned and connected with each element 100. Thus, when the connecting joints are connected with the respective elements, the pressure of the fluid is uniformly supplied from one of the elements 100 to the other.

[80] Each of the fixing means 150 has a structure in which the connecting rod 151, having opposite close-contact faces, the first fixing unit 153-1, producing frictional force against one of the close-contact faces of the connecting rod, and the second fixing unit 155-1, producing frictional force against the other close-contact face of the connecting rod, are coupled to each other. Thus, each of the fixing means 150 is adapted to cause the first and second fixing units to bring the internal tube 130 into close contact with respective close-contact faces of the connecting rod, thereby preventing the pressure of the fluid from leaking out when the pressure of the fluid is applied.

[81] Further, the first and second fixing units function to move the first and second actuating units 153 and 155, connected at the front thereof, in forward and backward directions, and prevent the internal tube from being rotated while directly coming into close contact with the internal tube. Thereby, the first and second actuating units prevent damage to the internal tube attributable to compressive rotation. [82] In addition, when the hydraulic pressure supply pipes 110, on which the internal tubes 130 are mounted, are interconnected by length extension units 300, each of which is provided with the connecting rods 151 at respective opposite ends thereof, the elements 100 are coaxially interconnected so as to be simultaneously expanded by means of the operation of first and second fixing units provided to each length extension unit and by means of the operation of actuating units connected to the first and second fixing units, thereby simultaneously cutting the drilled hole having a predetermined length on the whole.

[83] FIG. 13 is a perspective view illustrating a non-oscillatory rock cutting apparatus using hydraulic pressure according to another embodiment of the present invention. FIGS. 14 and 15 are an exploded perspective view and an exploded cross-sectional view of FIG. 13. FIG. 16 is an assembled cross-sectional view of FIG. 13.

[84] According to the present invention, in order to make it possible to bring an external tube 170 into close contact with first and second close-contact faces A and B formed on each connecting rod 151 when the external tube is sequentially assembled with a hydraulic pressure supply pipe 110 and the connecting rod 151, a first fixing unit 153-1 and a second fixing unit 155-1 are sequentially connected around opposite ends of the hydraulic pressure supply pipe 110.

[85] At this time, the second fixing unit 155-1 is supported by a second actuating unit

155, which is screwed to the outer circumference of the connecting rod 151. The first fixing unit 153-1 is provided with a first actuating unit 153 so as to bring the external tube 170 into close contact with the inside thereof.

[86] Meanwhile, the external tube 170 further includes external tube caps 180 on opposite sides thereof, particularly between the opposite sides thereof and the first fixing units 153-1, connected on opposite sides thereof, so as to control the direction in which the external tube is expanded.

[87] Further, when the hydraulic pressure supply pipes 110, on which the internal tubes

130 are mounted, are interconnected by length extension units 300, each of which is provided with the connecting rods 151 at respective opposite ends thereof, the elements 100 are coaxially interconnected so as to be simultaneously expanded by means of the operation of first and second fixing units provided to each length extension unit and by means of the operation of actuating units connected to the first and second fixing units.

[88] Also, the second fixing unit 155-1 is provided with a plurality of longitudinally oriented support slots 155- Ia in the inner circumference thereof. The connecting rod 151 is provided with a plurality of projections 151a so as to correspond to the support slots. Thus, the protrusions 151a are engaged with the support slots 155-la so as to prevent relative rotation. [89] In detail, the second actuating unit 155 is prevented from being rotated by the protrusions 151a of the connecting rod 151 so as to avoid additional forward movement.

[90] The first fixing unit 153-1 uniformly adjusts the close-contact force acting on one of the close-contact faces of the connecting rod when a support step 153- Ia, formed on one side thereof, comes into close contact with the end of the second fixing unit 155-1.

[91] The operation of the element of the present invention, which has the above- mentioned configuration, will be described.

[92] As illustrated in FIGS. 13 through 16, the fixing means 150 of the element are installed on respective opposite ends of the hydraulic pressure supply pipe 110. Thus, the constituent parts of each fixing means are sequentially connected in a longitudinal direction, thereby facilitating assembly.

[93] At this time, each of the fixing means 150 has a structure in which the connecting rod

151, having the opposite close-contact faces, the first fixing unit 153-1, producing frictional force against one of the close-contact faces of the connecting rod 151, and the second fixing unit 155-1, producing frictional force against the other close-contact face of the connecting rod 151, are coupled to each other. The second fixing unit 155-1 is screwed to the first fixing unit 153-1, to which the external tube 170 is coupled, and then when the second actuating unit 155, supporting the second fixing unit 155-1, is fastened, the opposite ends of the internal tube 130 are supported by the respective close-contact faces of the connecting rod 151.

[94] Referring to the fixing means 150 in detail, when the second actuating unit 155 is fastened to one side of the second fixing unit 155-1, the second fixing unit 155-1 is coupled while pulling the first fixing unit 153-1, and the second fixing unit 155-1 moves relative to the connecting rod 151. As a result, the opposite ends of the internal tube 130 are supported on the respective close-contact faces.

[95] At this time, the first actuating unit 155, which is detachably installed in front of the first fixing unit 153-1, comes into close contact with the first close-contact face A.

[96] Further, part of the connecting rod 151 is exposed to the outside in the state in which it is inserted into the second fixing unit 155-1. Thus, when the second actuating unit 155, engaged with the connecting rod 151, is rotated, the connecting rod 151 is firmly fixed to the second fixing unit 155-1, and the second fixing unit 155-1 comes into close contact with the second close-contact face B on the inner side thereof.

[97] Further, when coming into close contact with the first and second close-contact faces

A and B of the connecting rod 151, respectively, the first and second fixing units are not rotated but move linearly, thereby preventing the internal tube from being ruptured by the rotation.

[98] A positioning nut is prevented from coming loose by a cotter nut (not shown) on one side of the second actuating unit 155, so that the close-contact force of the tube is prevented from being reduced.

[99] Further, the second fixing unit 155-1 is provided with a plurality of longitudinally oriented support slots 155- Ia in the inner circumference thereof, thus preventing relative rotation using the protrusions 151a of the connecting rod 151, which are engaged with the support slots. This leads to a phenomenon in which at least two workers are required to prevent the rotation of the connecting rod 151 when the fixing means are coupled on opposite sides of the hydraulic pressure supply pipe 110.

[100] The second actuating unit 155 is prevented from additionally moving forwards due to the protrusions 151a on the connecting rod 151, and thus transmits only a coupling force to the tube. This prevents the internal tube from being damaged by compression resulting from the increase in the coupling force.

[101] Further, the first fixing unit 153-1 is prevented from additionally moving forwards when the support step 153- Ia, provided on one side thereof, comes into close contact with the end of the second fixing unit 155-1, and thus transmits only coupling force to the tube. This prevents the internal tube from being damaged by the increase in the coupling force.

[102] Meanwhile, when the hydraulic pressure supply pipes 110, on which the internal tubes 130 are mounted, are interconnected by length extension units 300, each of which is provided with connecting rods 151 at respective opposite ends thereof, the elements 100 are coaxially interconnected so as to be simultaneously expanded by means of the operation of first and second fixing units provided to each length extension unit and by means of the operation of actuating units connected to the first and second fixing units.

[103] FIG. 17 is a perspective view illustrating an external tube applied to a non-oscillatory rock cutting apparatus according to the present invention. FIG. 18 is a perspective view illustrating an external tube according to another embodiment of the present invention. FIGS. 19 through 22 are cross-sectional views illustrating examples of an external tube cap mounted on an external tube.

[104] The external tube 170 of the present invention is configured so that steps 177 are integrally formed with opposite ends of a hollow external tube body 171, which is made of elastic material such as rubber or urethane, having predetermined elasticity. The opposite ends of the hollow external tube body 171 are coupled with external tube caps 180. Each step 177 is integrally formed with a coupler 176, which is coupled with the first fixing unit 153-1.

[105] Further, the external tube body 171 and at least part of each step 177, extending from the external tube body, are integrally formed with a first reinforcing member 172 on outer circumferences thereof. [106] The first reinforcing member 172 is made of a natural or artificial fabric layer having high elasticity.

[107] The fabric layer may have a cylindrical integral structure disposed on the outer circumferences of the external tube body and each step, or a multi-layered structure in which pieces of woven fabric having predetermined strength are alternately stacked on the outer circumferences with a predetermined width and thickness.

[108] Further, the external tube body 171 is selectively provided with a locking step and an inclined face on a line connected with each step 177.

[109] The external tube cap 180 is substantially in contact with the outer circumference of the step 177, is expanded in a radial direction when expanded, and is formed to withstand the longitudinal stress of the external tube 170.

[110] The external tube cap 180 includes a hollow cap body 182, made of elastic material such as rubber or urethane, having predetermined elasticity, and a support segment assembly 181 assembled by a plurality of metal support segments 181a radially disposed on the outer circumference of the external tube 170 so as to be expanded and contracted.

[I l l] Further, the support segment assembly 181 is configured so that the support segments are radially disposed on the circumference of the external tube 170.

[112] In addition, the support segment assembly 181 is configured so that the support segments are radially disposed on the circumference of the external tube 170 and are alternately stacked in a longitudinal direction.

[113] The cap body 182 has a support face, which corresponds to the inclined face or the locking step of the external tube and is integrally formed on the inner circumference of one end thereof.

[114] The support segment assembly 181 and the cap body 182 are detachably installed.

[115] Further, the support segment assembly 181 may be completely separated from the cap body 182, or may be fitted around the outer circumference of the cap body 182, particularly of a mounting step 182a formed on one side of the cap body 182.

[116] Further, the support segment assembly 181 is configured so that metal support blocks 183 having a predetermined thickness are radially disposed on the outer circumference of the external tube on one side thereof.

[117] The operations of the external tube and the external tube cap, mounted on the external tube, having the above-mentioned configuration, both of which constitute the element used for the non-oscillatory rock cutting apparatus of the present invention, will be described.

[118] As illustrated in FIGS. 17 through 22, the external tube 170 of the present invention is prevented from being exposed by a gap between the external tube cap 180 and the drilled hole IOOA when the internal tube 130, installed inside the external tube, is expanded, and thus the pressure is transmitted from the inside to the outside of a blasting hole.

[119] At this time, the step 177, on which the external tube cap 180 is mounted, is adapted so that the pieces of woven fabric are integrally connected to form a conical shape on the outer circumference of the step, or so that the woven fiber having a predetermined area is alternately stacked on the outer circumference of the step. Thus, the step is expanded when the external tube is expanded, thereby preventing the external tube 170 from being ruptured.

[120] Further, the external tube 170 further includes a second reinforcing member 173 made of metal on the outer circumference thereof. When the external tube 170 is expanded, the second reinforcing member 173 installed on the external tube 170 is located in the gap (between the external tube cap 180 and the drilled hole 100A), thereby preventing the external tube from being expanded between the external tube cap 180 and the blasting hole.

[121] At this time, the external tube body 171 is made of elastic material such as rubber or urethane having predetermined elasticity, and thus can be restored after the expansion and contraction thereof.

[122] The external tube cap 180, which is inserted into the step 177 of the external tube

170, is expanded as soon as the external tube 170 is expanded, thereby preventing the external tube 170 from being expanded in a longitudinal direction.

[123] Further, the external tube body 171 is selectively provided with a locking step and an inclined face on a line connected with each step 177, thereby bringing the external tube cap 180, having its corresponding shape, into close contact with the outer circumference thereof.

[124] Meanwhile, the external tube cap 180, mounted on the external tube 170, is in close contact with the outer circumference of the step 177, and is expanded in a radial direction when the external tube is expanded, thereby minimizing the distance from the blasting hole, and thus withstands the longitudinal stress of the external tube 170.

[125] The external tube cap 180 has the cap body 182 in which elastic material, such as rubber or urethane having predetermined elasticity, is placed between the plurality of metal support segments 181a, which are radially disposed on the outer circumference of the external tube 170 so as to be expanded and contracted. Thereby, the support segment assembly 181 maintains a predetermined shape.

[126] At this time, the support segment assembly 181 is formed as an integral structure in which the plurality of support segments 181a is disposed in a mold, and then the elastic material is injected between the support segments, thereby maintaining a uniform shape at all times.

[127] Further, the support segment assembly 181 is configured so that the support segments are radially disposed on the circumference of the external tube 170. When the support segments are expanded, the intervals between the support segments disposed on the circumference of the external tube are increased, so that the support segments firmly support the external tube 170.

[128] In addition, the support segment assembly 181 is configured so that the support segments having predetermined strength are radially spaced apart from each other on the outer circumference of the external tube and are alternately stacked in a longitudinal direction. Thus, even when the support segments are expanded such that the diameter of the support segment assembly is increased in a radial direction, the support segments firmly support the external tube 170.

[129] The support segment assembly 181 may be separated from the cap body 182. This configuration has the same effect as the above-mentioned configuration. In this manner, only the support segment assembly 181, which is easily damaged by repeated expansion and contraction, is separately formed, so that the cost of production can be reduced.

[130] Further, the support segment assembly 181 further includes the support blocks 183, having a predetermined thickness, on one side thereof, thereby preventing the pressure from leaking out through joints of the support segments, and thus preventing durability thereof from being reduced by deformation.

[131] FIGS. 23 and 24 are exploded views illustrating an external tube gap applied to an external tube according to another embodiment of the present invention. FIG. 25 is a cross-sectional view illustrating the state in which an external tube gap is mounted on an external tube according to another embodiment of the present invention. FIGS. 26 and 27 are cross-sectional views illustrating an external tube gap according to another embodiment of the present invention. FIG. 28 is a cross-sectional view illustrating the operation of an external tube gap according to another embodiment of the present invention.

[132] The external tube 170 according to another embodiment of the present invention is configured so that steps 177 are integrally formed with opposite ends of a hollow external tube body 171, which is made of elastic material, such as rubber or urethane having predetermined elasticity. The opposite ends of the hollow external tube body 171 are coupled with external tube caps 180.

[133] Each of the external tube caps 180 mounted on the steps 177 of the external tube 170 has a structure in which variable blocks 186, positioning blocks 185, and a support member 187, supporting these blocks, are assembled with each other.

[134] The variable blocks 186 are opposite each other when installed, and each include a first contact face 186c in the middle thereof so as to correspond to the outer diameter of the external tube 170, and linear slide faces 186d at opposite ends thereof. [135] At this time, each variable block 186 further includes at least one slot 186b having an arcuate shape in the outer circumference thereof.

[136] Further, each variable block 186 further includes a linear support face 186a on at least one end thereof.

[137] In addition, the inner circumference of each variable block 186, including the first contact face, further includes at least one slot 186c-l having an arcuate shape.

[138] Each positioning block 185 is provided with contact faces 185b corresponding to the slide faces 186d of each variable block 186 and a second contact face 185a on the inner circumference thereof, which corresponds to the outer diameter of the external tube 170 and is formed so as to have a gap D between the ends of the opposite variable blocks.

[139] Further, each positioning block 185 is provided with at least one slot 185a-l having an arcuate shape in the second contact face 185, and a flat pressure face 185b-l opposite the second contact face 185.

[140] The pressure face 185b-l is provided with at least one slot (not shown) having an arcuate shape.

[141] The support member 187 is made of elastic material such as rubber or urethane having predetermined elasticity so as to enclose at least part of the outer or inner circumferences of the variable blocks and the positioning blocks.

[142] Further, the external tube cap 180 further includes a separate external tube sub-cap 180A on at least one side thereof.

[143] The external tube sub-cap 180A is configured so that elastic material 180A-2, such as rubber or urethane having predetermined elasticity, is placed between the plurality of metal support segments 18 IA-I, which are radially disposed on the outer circumference of the external tube 170 so as to be expanded and contracted.

[144] Further, the external tube sub-cap 180A is configured so that, when the support segments 180A-1 having predetermined strength are radially spaced apart from each other on the outer circumference of the external tube and are alternately stacked in a longitudinal direction, the elastic material 180A-2, such as rubber or urethane having predetermined elasticity, is filled between the support segments 180A-1.

[145] Now, the operation of the external tube cap, configured as described above, mounted on the external tube, will be described.

[146] As illustrated in FIGS. 23 through 28, the external tube cap 180 is adapted to assemble the variable blocks 186 with the positioning blocks 185 located inside the variable blocks, and then to install the support member 187 on the outer or inner circumference of the assembled blocks. Thus, the external tube cap is inserted into the step 177 of the external tube 170 through the inner circumference thereof, and thereby, the variable blocks and the positioning blocks are formed in a predetermined shape by the support member. As a result, the external tube cap maintains a predetermined ring shape.

[147] In other words, the external tube 170 is enclosed by the first contact surfaces 186c of the variable blocks 186 and the second contact faces 185a of the positioning blocks 185 on the outer circumference thereof.

[148] At this time, the external tube cap 180 is adapted to be expanded by external force or be restored while the variable blocks 186 and the positioning blocks 185, which are in close contact with each other, are formed and supported in a predetermined shape by the support member 187 made of elastic material such as rubber or urethane having predetermined elasticity.

[149] As described above, the external tube cap 180 is adapted so that, when the external tube 170 is expanded, the expansion pressure is transmitted to the first and second contact faces 186c and 185a.

[150] The pressure transmitted to the second contact faces 185a is applied to the slide faces 186d of the variable blocks 186 and the pressure faces 185b-l of the positioning blocks 185, thereby pushing the variable blocks 186 in a radial outward direction so as to increase the inner diameter of the external tube cap 180.

[151] At this time, in the case of the external tube cap 180, the support member 187, covering the outer or inner circumference of the variable blocks 186, is expanded, and thus the diameter of the external tube cap is changed in response to a change in the diameter of the support member.

[152] When mounted on the inner circumferences of the variable blocks 186, the positioning blocks 185 are installed so as to have a predetermined gap D between the ends of the opposite variable blocks 186. Thus, when the pressure is applied to the tube, the positioning blocks 185 are easily displaced through the gap, and thus the variable blocks 186 can be expanded in opposite directions.

[153] Further, each variable block 186 has the linear support faces 186a on opposite ends thereof, so that it can increase the contact area with the support member 187 to thereby increase the contact force therewith. When the support member 187 is displaced depending on the expansion of the positioning blocks 185, the variable blocks 186 absorb part of the support member, so that they can be easily displaced.

[154] The slots, which are selectively formed in the inner circumferences of the variable blocks 186 or in the inner and outer circumferences of the positioning blocks 185, have an arcuate shape, and thus increase the contact area of the support member 187 so as to be firmly supported.

[155] Meanwhile, the external tube cap further includes the separate external tube sub-cap 180A on at least one side thereof so as to easily cope with diametrical expansion or longitudinal expansion thereof. [156] At this time, the external tube sub-cap 180A is configured so that the elastic material, such as rubber or urethane having predetermined elasticity, is filled between the plurality of support segments, which are radially disposed on the outer circumference of the external tube so as to be expanded and contracted, or which are radially spaced apart from each other on the outer circumference of the external tube and are alternately stacked in a longitudinal direction. Thus, when the external tube is expanded, the external tube sub-cap is simultaneously expanded, and supports the external tube to prevent the loss of pressure.

[157] The external tube 170, to which the external tube cap 180 is applied, is prevented from being damaged in a manner such that a plurality of support rings 400, enclosing the outer circumference of the external tube, is supported by at least one elastic band 410 disposed around each support ring.

[158] FIGS. 29 and 30 are a circuit diagram and a detailed connection diagram illustrating an apparatus for controlling hydraulic pressure according to an embodiment of the present invention. FIGS. 31 and 32 are detailed cross-sectional views illustrating an operating cylinder applied to an apparatus for controlling hydraulic pressure according to an embodiment of the present invention. FIGS. 33 and 34 are a circuit diagram and a detailed connection diagram illustrating an apparatus for controlling hydraulic pressure according to another embodiment of the present invention. FIG. 35 is a connection diagram illustrating an apparatus for controlling hydraulic pressure according to yet another embodiment of the present invention. FIG. 36 is a detailed cross-sectional view illustrating an operating cylinder applied to an apparatus for controlling hydraulic pressure according to another embodiment of the present invention.

[159] The hydraulic pressure controlling apparatus O is installed so as to expand and contract the element 100 of a non-oscillatory rock cutting apparatus using hydraulic pressure according to another embodiment of the present invention, which uses hydraulic pressure. The hydraulic pressure controlling apparatus O comprises a fluid feed and return section A, a pressure control section C connected to the fluid feed and return section A, a pressure boosting section B having a plurality of unit pressure boosting units B-I, operating cylinders 570 transmitting the pressure of one fluid fed from the pressure boosting section to the element 100 of the non-oscillatory rock cutting apparatus using the pressure of another fluid.

[160] The fluid feed and return section A is installed so as to drive a pump 508, which is installed on a fluid tank 502 having an oil level gauge and an inlet port, using a drive motor 510.

[161] At this time, the pump 508 is connected to a line filter 506 via a first check valve 507 installed in a hydraulic line, and filters dust, foreign materials, etc. present in a fluid. The line filter comprises a switch, a filter, and a check valve. [162] The fluid passing through the line filter 506 is fed to the pressure control section C.

[163] Further, a return filter 503 is additionally installed inside the fluid tank 502 via a cooler 505, and is connected on return sides of the pressure boosting units B-I.

[164] The pressure control section C includes a needle valve 564, which is connected to the line filter 506 and has a pressure gauge 563, and a one-way diverter valve 561 installed via a relief valve 562.

[165] The pressure boosting section B includes a plurality of two-way diverter valves 565, which simultaneously supply fluid pressure supplied through the one-way diverter valve 561, and boosters 540, which continuously compress the fluid connected to and fed from the two-way diverter valves 565 and boost the fluid up to a predetermined pressure.

[166] At this time, a flow control valve 560 is additionally connected to the feed side of each two-way diverter valve 565.

[167] An input side of at least one operating cylinder 570 is connected to an output side of each booster 540. Each operating cylinder 570 is connected to the element 100 of the non-oscillatory rock cutting apparatus inserted into the hole IOOA drilled in the rock G.

[168] At this time, one of output sides of each operating cylinder 570 is connected with a fluid pump 590, which is mounted in a tank in which another fluid is stored, via a second check valve 580.

[169] Further, each operating cylinder 570 is provided therein with a piston 571. The piston 571 is provided with sealing members 575 and 573. When the piston 571 is completely displaced in either direction, the sealing members 575 and 573 function to interrupt the inflow of the fluid through an inlet port 574 connected with the fluid pump 590, and a fluid port 576 connected to the booster 540 of each pressure boosting unit B-I and allowing a working fluid to be introduced.

[170] Meanwhile, each operating cylinder 570 is provided therein with a piston 571. The piston 571 is provided with sealing members 575 and 573, and a recess 576 in the middle thereof so as to communicate with a discharge hole 577 formed therein. The discharge hole 577 is connected with a connecting pipe 579 extending through the cylinder.

[171] The operation of the hydraulic pressure controlling apparatus, configured as described above, installed to supply the hydraulic pressure to the element 100 of the present invention, will be described.

[172] As illustrated in FIGS. 29 through 36, the hydraulic pressure controlling apparatus of the present invention is designed so that, when the fluid pump 508, housed in the fluid tank 502, is operated by a switch or an external radio signal, one fluid, such as oil, is fed from the fluid pump to the line filter 506.

[173] At this time, the first check valve 507 is installed on a feed line for the line filter 506, and thus prevents the return of the fluid. The fluid tank is provided with the oil level gauge and a tank cap. Thus, the fluid is supplied through periodical observation, and is thereby stored in the tank at a predetermined level.

[174] The line filter 506 includes the switch, the filter and the check valve, and eliminates dust and foreign materials present in the fluid to thus prevent the pipe or the valve from being blocked by the fluid.

[175] The fluid passing through the line filter 506 is fed to the relief valve 562 through the feed line, and returns the fluid until the pressure in the circuit reaches setting pressure, thereby adjusting the pressure of the fed fluid, and then feeding the adjusted fluid to the one-way diverter valve 561.

[176] Here, before the fluid is fed to the relief valve 562, the flow rate of the fluid passing through a needle valve 564 having the pressure gauge 563 is controlled.

[177] Further, the one-way diverter valve 561 braches off the pressure of the fluid, and feeds the branched pressure to the plurality of two-way diverter valves 565. A recirculation port R in each two-way diverter valve 565 is connected to a feed line of the needle valve 564.

[178] The feed line for the two-way diverter valves 565 is connected with a return line for returning the fluid to the fluid tank. Thus, the return line returns the fluid when the pressure is sufficiently raised by the pressure boosting units B-I. The pressure boosting units B-I can produce the fluid having sufficiently high pressure through a process in which the boosters 540 continuously repeat feed and compression (strike) of the fluid.

[179] At this time, the return line is also provided with the cooler 505 and the return filter 503. Thus, the return line cools the fluid, the temperature of which is raised by continuous compression when the pressure is boosted, eliminates foreign materials in the fluid, and returns the fluid to the fluid tank.

[180] Further, the fluid fed to the two-way diverter valves 565 is fed to the respective boosters 540 connected to the two-way diverter valves, and thus is boosted up to a setting pressure.

[181] The feed line for each booster 540 is provided with the flow control valve 560, which feeds the fluid to each booster at a constant flow rate without a change in pressure caused by back pressure or negative pressure. Thus, the state in which the pressure is raised by the booster can be uniformly maintained.

[182] Further, each booster 540 is configured to have a dump valve DV in which the flow control valve is connected with a piston OP having a low-pressure piston and a high- pressure piston. When the fluid is fed to the recirculation port R, the high-pressure piston is operated to compress the fluid fed to the low-pressure piston through check valves KVl and KV2 and the dump valve. Then, when the high-pressure piston reaches setting pressure, the check valve KVl and the dump valve DV are blocked, and the fluid, compressed at high pressure, is fed to the operating cylinder 570 through an inlet port IN.

[183] The fluid, fed to the operating cylinder 570, is adapted to be raised only up to predetermined pressure through the pressure gauge 563.

[184] The operating cylinder 570 is designed so that the boosted fluid described above is present on one side of the piston 571, and another fluid is present on the other side of the piston. Thus, the pressure of one fluid acts on the other fluid, thereby producing pressure.

[185] In this embodiment, the other fluid present on the other side of the piston 571 is water. The water is fed by the fluid pump 590 housed in the fluid tank so as to maintain predetermined pressure, and is repeatedly compressed through the piston 571 operated by one fluid, so that desired pressure of the fluid can be obtained.

[186] Further, the fluid fed by the fluid pump is prevented from being returned through the second check valve 580, and is continuously fed in a required amount.

[187] Further, at least one operating cylinder 570 can be connected to the booster 540 of each pressure boosting unit B-I when used.

[188] The operating cylinders 570 are installed so as to correspond to the elements 100 of the non-oscillatory rock cutting apparatus inserted into the hole IOOA drilled into the rock G in a one-to?one manner. It does not matter whether a plurality of operating cylinders 570 is connected to one element 100, as long as they perform the compression and return of the fluid.

[189] As described above, the elements 100 for the non-oscillatory rock cutting apparatus of the present invention are connected to the operating cylinders, to which power is transmitted by the boosters of the individual pressure boosting units, and thus are individually operated. As such, when one of the elements is damaged to thus suffer the leakage of the fluid, the other elements are operated regardless of the damaged element, so that it is possible to eliminate the phenomenon in which the rock cannot be cut due to the pressure loss.

[190] Further, each operating cylinder 570 is designed so that the stroke of the piston 571 is adjusted so as to produce pressure corresponding to the expansion of the rubber tube of the non-oscillatory rock cutting apparatus, and so that, when compressive force created by one fluid is transmitted, the pressure is transmitted to the other fluid on the other side of the piston. Thus, only the necessary pressure is transmitted from the other fluid, the non-oscillatory rock cutting apparatus is prevented from being damaged by overloading, and accidents caused by the rupture of the tube are prevented.

[191] At this time, when the piston 571 of each operating cylinder 570 completely moves forward, the inflow of the other fluid through the fluid inflow port 574 is interrupted, and when the tube is ruptured, the fluid is no longer fed. When the piston 571 is returned, vacuum pressure is produced to open the second check valve 580, and thus the other fluid, fed to the tube, flows back to the water tank.

[192] Meanwhile, each operating cylinder 570 prevents leakage through the sealing members 575 and 573 installed on the outer circumference of the piston 571, and removes the fluid from the wall of the cylinder. The removed fluid is discharged to the outside through the recess 576 and the discharge hole 577, so that malfunctions occurring due to the mixture of one fluid with the other fluid are preemptively prevented.

[193] Next, the other fluid fed by the fluid pump is prevented from being returned through the second check valve 580, and is continuously fed in a required amount. When a pressure difference occurs at the pressure gauge 563, it is determined that the fluid leaks out, and thus the operation of the fluid pump 590 is stopped.

Claims

[1] A non-oscillatory rock cutting apparatus using hydraulic pressure, in which: at least one element is inserted into a drilled hole so as to produce expansion pressure by means of pressure of a fed fluid, and is expanded in the drilled hole by the pressure of the fluid; and the element supports opposite ends of an internal tube, which is fitted around an outer circumference of a hydraulic pressure supply pipe having a main line and branch lines passing through the main line in a direction of intersecting the main line, through fixing means which support the opposite ends of the internal tube with two or more faces thereof, to define an air-tight space outside the hydraulic pressure supply pipe, and expands the internal tube by the pressure of the fluid supplied to the hydraulic pressure supply pipe.

[2] The non-oscillatory rock cutting apparatus as set forth in claim 1, wherein each of the fixing means includes: a connecting rod, which has a plurality of close-contact faces and is screwed to the hydraulic pressure supply pipe; a first fixing unit, which is supported outside the connecting rod so as to produce a close-contact force corresponding to one of the close-contact faces of the connecting rod; and a second fixing unit, which is supported outside the connecting rod so as to produce a close-contact force corresponding to the other close-contact face of the connecting rod.

[3] The non-oscillatory rock cutting apparatus as set forth in claim 2, wherein the first fixing unit is coupled to the connecting rod by rotation, freely moves in front of the connecting rod when moving, and cooperates with a first actuating unit having a contact face corresponding to one of the close-contact faces so as to transmit only a compressive force.

[4] The non-oscillatory rock cutting apparatus as set forth in claim 2, wherein the second fixing unit is coupled to the connecting rod by rotation, freely moves in front of the connecting rod when moving, and cooperates with a first actuating unit having a contact face corresponding to the other close-contact face so as to transmit only a compressive force.

[5] The non-oscillatory rock cutting apparatus as set forth in claim 1, wherein each of the fixing means includes: a connecting rod, which has a plurality of close-contact faces and is coupled to the hydraulic pressure supply pipe on an inner circumference thereof; a first fixing unit, which produces a close-contact force corresponding to one of the close-contact faces of the connecting rod; and a second fixing unit, which is coupled to an outer circumference of another end of the first fixing unit so as to hold the connecting rod, is supported by a positioning nut coupled to the connecting rod, and produces a close-contact force corresponding to the other close-contact face of the connecting rod.

[6] The non-oscillatory rock cutting apparatus as set forth in claim 5, wherein the first fixing unit is separated from the first actuating unit, which is formed so as to correspond to the close-contact face, so as to transmit only a compressive force.

[7] The non-oscillatory rock cutting apparatus as set forth in claim 5, wherein the first fixing unit includes a plurality of support slots in an inner circumference thereof, and the connecting rod includes protrusions corresponding to the support slots so as to prevent relative rotation.

[8] The non-oscillatory rock cutting apparatus as set forth in claim 5, wherein the second fixing unit is prevented from additionally moving forward by the protrusions of the connecting rod so as to adjust close-contact force.

[9] The non-oscillatory rock cutting apparatus as set forth in claim 5, wherein the second fixing unit uniformly adjusts a close-contact force applied to one of the close-contact faces of the connecting rod when a support step formed on one side thereof comes into close contact with an end of the first fixing unit.

[10] The non-oscillatory rock cutting apparatus as set forth in any one of claims 1 through 9, wherein one of the elements is connected to another element so as to expand the respective tubes through a connecting joint, which has valve openers so as to open check valves provided at opposite ends of the hydraulic pressure supply pipe.

[11] The non-oscillatory rock cutting apparatus as set forth in any one of claims 1 through 9, wherein, when the hydraulic pressure supply pipes, on which the tubes are mounted, are interconnected by a plurality of length extension units, each of which includes the connecting rods at respective opposite ends thereof, the elements are coaxially interconnected so as to be simultaneously expanded by means of operation of first and second fixing units provided to each length extension unit and actuating units connected to the first and second fixing units.

[12] The non-oscillatory rock cutting apparatus as set forth in claim 1, wherein the internal tube further includes an external tube, which is supported by the fixing means, on an outer circumference thereof.

[13] The non-oscillatory rock cutting apparatus as set forth in claim 12, wherein the external tube includes a first reinforcing member on an inner circumference thereof such that external tube caps are mounted on opposite ends of a hollow external tube body.

[14] The non-oscillatory rock cutting apparatus as set forth in claim 13, wherein: the first reinforcing member is made of one of natural and artificial fabric layers having high elasticity; and the fabric layer is integrally formed with the external tube body made of elastic material in any one selected from a cylindrical structure in which one layer is integrally connected on a circumference and a layered structure in which layers are alternately stacked on a circumference.

[15] The non-oscillatory rock cutting apparatus as set forth in claim 13, wherein the external tube includes a second metal reinforcing member on one side of the first reinforcing member of the external tube body.

[16] The non-oscillatory rock cutting apparatus as set forth in any one of claims 12 through 15, wherein the external tube further includes a step in an end thereof, and additionally has the external tube cap mounted thereto.

[17] The non-oscillatory rock cutting apparatus as set forth in claim 16, wherein: each external tube cap has a structure in which variable blocks, positioning blocks, and a support member supporting these blocks are assembled with each other; the variable blocks are opposite to each other when installed, and each include a first contact face corresponding to an outer diameter of the external tube, and linear slide faces extending from the first contact face; the positioning blocks include contact faces corresponding to the slide faces of the variable blocks, and second contact faces on inner circumferences thereof so as to correspond to the outer diameter of the external tube, and are formed so as to have gaps between ends of the opposite variable blocks; and the support member is formed so as to enclose at least part of outer or inner circumferences of the variable blocks and the positioning blocks.

[18] The non-oscillatory rock cutting apparatus as set forth in claim 17, wherein each variable block further includes at least one slot having an arcuate shape in an ou ter circumference thereof.

[19] The non-oscillatory rock cutting apparatus as set forth in claim 17, wherein each variable block further includes a linear support face on at least one end thereof.

[20] The non-oscillatory rock cutting apparatus as set forth in claim 17, wherein each variable block further includes at least one slots having an arcuate shape in the first contact face.

[21] The non-oscillatory rock cutting apparatus as set forth in claim 17, wherein each positioning block includes at least one slot having an arcuate shape in the second contact face, and a flat pressure face opposite the second contact face.

[22] The non-oscillatory rock cutting apparatus as set forth in claim 16, wherein the external tube cap further includes an external tube sub-cap on at least one side thereof.

[23] The non-oscillatory rock cutting apparatus as set forth in claim 22, wherein the external tube sub-cap includes a plurality of metal support segments, which are radially disposed on the outer circumference of the external tube so as to be expanded and contracted, and between which elastic material, such as rubber or urethane having predetermined elasticity, is placed.

[24] The non-oscillatory rock cutting apparatus as set forth in claim 22, wherein the external tube sub-cap includes support segments having predetermined strength, between which elastic material, such as rubber or urethane having predetermined elasticity, is filled when the support segments are radially spaced apart from each other on the outer circumference of the external tube and are alternately stacked in a longitudinal direction.

[25] The non-oscillatory rock cutting apparatus as set forth in claim 16, wherein the external tube cap includes a cap body made of elastic material selected from among rubber and urethane, and a support segment assembly radially disposed on the outer circumference of the external tube so as to be expanded and contracted, the cap body and the support segment assembly being integrally formed with each other.

[26] The non-oscillatory rock cutting apparatus as set forth in claim 25, wherein the support segment assembly includes support segments radially disposed on the circumference of the external tube.

[27] The non-oscillatory rock cutting apparatus as set forth in claim 25, wherein the support segment assembly has the support segments having predetermined strength which are radially disposed on the outer circumference of the external tube and are alternately stacked in a longitudinal direction.

[28] The non-oscillatory rock cutting apparatus as set forth in claim 26 or 27, wherein the support segment assembly and the cap body are detachably installed.

[29] The non-oscillatory rock cutting apparatus as set forth in claim 26 or 27, wherein the support segment assembly further includes at least one support block having a predetermined thickness on one side thereof.

[30] A method of controlling hydraulic pressure of a non-oscillatory rock cutting apparatus, comprising the steps of: supplying pressure of one fluid, which is boosted by unit pressure boosting units, to one side of at least one operating cylinder, which is connected to the corresponding unit pressure boosting unit, so as to be applied to one side of a piston of the operating cylinder; continuously feeding another fluid to another side of the piston using a fluid pump so as to have a volume corresponding to that of an expanding external tube; and continuously feeding the other fluid on the other side of the piston to the non- oscillatory rock cutting apparatus when the pressure of the one fluid is repeatedly applied to one side of the piston so as to expand an internal tube.

[31] The method as set forth in claim 30, wherein: each pressure boosting unit maintains one fluid in a fluid tank at static pressure by a relief valve when the fluid in the fluid tank is fed to a one-way diverter valve by the fluid pump; the relief valve includes a needle value installed on a feed line thereof so as to constantly regulate a flow rate of the fluid, returns the fluid, which is fed from the one-way diverter valve, to the fluid tank while the returned fluid is cooled and filtered by a cooler and a return filter installed on a return line; and each pressure boosting unit includes a two-way diverter valve branching off from and connected to the one-way diverter valve, and a flow control valve and a booster connected to the two-way diverter valve, boosts the constantly fed fluid up to a setting pressure, and feeds the boosted fluid to the corresponding operating cylinder.

[32] The method as set forth in claim 30 or 31, wherein the booster includes a dump valve in which the flow control valve is incorporated with a piston in which a low-pressure piston is integrated with a high-pressure piston, and allows the fluid to be fed to a recirculation port, to be compressed up to the setting pressure, and to be fed to the operating cylinder through an inlet port.

[33] The method as set forth in claim 31, wherein the operating cylinder blocks the other fluid from being fed through a hydraulic pump when the piston completes forward movement by means of the pressure of one fluid, and returns the other fluid to the fluid tank by means of a pressure difference when the piston moves backward.

[34] The method as set forth in claim 31, wherein the booster is connected with a pressure gauge in an outlet port side thereof so as to stop operation of the fluid pump when loss of pressure occurs.

[35] The method as set forth in claim 31, wherein the operating cylinders are connected to one non-oscillatory rock cutting apparatus, and feed pressure of the fluid to the non-oscillatory rock cutting apparatus such that the non-oscillatory rock cutting apparatus is contracted and expanded in a hole drilled in rock.

[36] The method as set forth in claim 31, wherein the operating cylinder prevents leakage of the fluid and removes the fluid adhered to a wall thereof through at least one sealing member installed on an outer circumference of the piston, and discharges the removed fluid using a discharge hole connected to a recess.