JPS6145033B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for cleaving rocks, according to which a hole is drilled in a rock, a radially expandable cleaving rod is inserted into the hole, and the cleaving rod is connected to a power plant. This causes the rock to expand, creating a pressure on the wall of the hole that exceeds the breaking strength of the rock.

Incidentally, the term "rock" primarily relates to the rock material itself or to cement concrete or other similar materials, and the method according to the invention includes not only the cleavage of separated stones and rock masses, but also rock excavation.

In order to avoid the drawbacks associated with cleavage and excavation carried out by blasting, many methods and tools have been developed that are based on the destruction of rocks by mechanical means operated by pressurized fluids.

From West German Patent Publication No. 1294305, a cutting rod operated by compressed air and inserted into a hole drilled in the rock is connected at one end to a compressed air accumulator and tensioned in the closed position by a safety pin at the other end. Devices are already known which include flexible tubes equipped with valves. As the pressure in the flexible tube increases,
The tube expands radially outwards, so that it is pressed against the perforation wall, simultaneously sealing the hole and exerting pressure on the rock. When the pressure reaches a sufficiently high height, the safety cap of the valve ruptures and an instantaneous jet of air is injected into the borehole through the radial bore of the valve, whereby the pressure impulse created by the air jet and the pressure rupture rocks.

However, such a cleavage method causes a cleavage comparable to an explosion due to the sudden pressure shock generated, whereby rock fragments are easily thrown into the surroundings, and the cleavage is not carried out in a well-controlled manner.

A hydraulically actuated mechanical wedge is already known from Swedish Patent Publication No. 401,706, which comprises a wedge in which the cleaving rod moves between two wedge-shaped jaws. A hydraulic cylinder forces the wedge between the jaws and the pressure created by the jaws breaks the rock.

Such a cleavage method has the disadvantage that when the walls of the drill hole are uneven, a peak concentration of force occurs between the integral jaw and the wall of the hole, which causes the rock to burst uncontrollably.

The object of the invention is to eliminate the above-mentioned drawbacks and to provide a method that allows precise control of the cleavage.
This object is achieved in a method according to the invention, characterized in that the cleaving rod expands radially by axially compressing a pressure member of elastic material into the hole.

According to the invention, a cleaving method is provided in which the pressure member of the elastic member is able to adapt to the irregularities of the wall of the borehole, so that an evenly distributed pressure effect is produced on the borehole despite the irregularities. Since the pressure effect results from the radial expansion of the elastic pressure member as it becomes increasingly compressed axially in the hole, the pressure effect can be steadily increased until the rock ruptures. Therefore, a sudden explosion of too great a force occurs, as a result of which pieces of rock are thrown around,
Cleavage does not become uncontrollable.

The invention also relates to a tool for carrying out the above method,
This tool is characterized by being limited to claim 3.

The tool according to the invention is simple in construction and easy to process automatically.

The invention will now be described in more detail with reference to the accompanying drawings.

The cleaving tool shown in FIGS. 1 and 2 mainly includes a cleaving rod 1 and a hydraulic cylinder 2 fixed thereto. Instead of hydraulic cylinders, other commonly known power means may be used.

The cleaving rod 1 has a cylindrical bar 3 with a head 4 wider than the rod at one end, a tube 5 through which the bar 3 extends slidably with a slight gap, and the head 4 and the tube 5. a sleeve-like pressure member 6 located between and through which the bar 3 extends;
Contains. The head 4 forms an annular support surface 4a in contact with one end face of the pressure member, and the tube 5 forms a support surface 5a in contact with the other end face of the pressure member.Head 4, tube 5 and member 6 are in their inactive positions. A cylindrical surface with a diameter slightly smaller than the diameter of the hole 8 drilled in the rock 7 to be ruptured is formed.

The hydraulic cylinder 2 includes, for example, a housing 9 integrally fixed to the tube 5 and a piston 10 integrally fixed to the bar 3. Cylinder space 11 is pipe 1
2 through a conventional actuated valve 13 to a hydraulic fluid source 1
It is connected to 4.

The pressure member 6 is made of a stretchable material that is deformable and whose volume remains substantially uncompressed when the member is compressed by an external force. Suitable materials are, for example, various rubbers and polyurethanes.

The cleaving tool operates as follows.

The cleavage rod 1 is inserted into a hole drilled in the rock to be cleaved so that the pressure member 6 is completely located within the hole. Hydraulic pressure is then applied to the cylinder space 11, which causes the piston to move upwards relative to the housing and the bar 3 in the corresponding direction relative to the tube 5. This causes an axial compression of the pressure member between the support surfaces 4a and 5a, which causes it to expand radially outwards correspondingly and to be pressed sealingly against the wall of the borehole with its entire envelope surface. Ru.
As the hydraulic cylinder pulls the bar upwards, the pressure exerted by the radial expanding pressure on the rock increases. When the pressure exceeds the breaking strength of the rock, the rock is cleaved. Pressure is then released from the cylinder space, whereby the bar returns to its original position under the pressing action of the elastic pressure member, ready for the cleaving rod to be inserted into the next drilling hole.

The cleavage tool is very simple in construction and operation and, thanks to the elastic member, the pressure exerted on the rock by the cleavage tool is evenly distributed over the entire wall surface of the borehole, even if it is uneven. The force used to cleave the rock is no greater than required for the fracture strength of the rock, so that explosion-like destruction is not produced and the cleavage is precisely controlled.

According to FIG. 3, when using pressure fluids, multiple cleaving rods can be connected to the same pressure source to break apart, for example, lumps of a certain shape. Furthermore, a flow control valve 15 may be attached to each tool 1,2. Without a flow control valve, when the rock ruptures, the tool expands slightly more at the point where the rupture begins, simultaneously causing a momentary pressure drop in other tools. When using a flow control valve, cleaving is performed with greater force since the pressure reduction does not affect other tools, but their pushing force remains the same.

The drawings and descriptions herein are merely intended to illustrate the concepts of the invention. In details, the method according to the invention and the tools for carrying out the method may vary within the scope of the claims.

[Brief explanation of the drawing]

Figures 1 and 2 show an embodiment of the cleavage tool according to the present invention, in which it is installed in a drilled hole, and is a partial vertical sectional view showing the state before and after cleaving, respectively, and Figure 3 shows an embodiment of the cleavage tool according to the present invention. FIG. 3 shows several cleavage tools connected together; 1: Cleavage rod, 2: Hydraulic cylinder (power means), 3: Cylindrical bar, 4: Head (pressure member support), 5: Pipe (pressure member support), 6: Pressure member,
7: Rock, 8: Perforation, 9: Hydraulic cylinder housing, 10: Piston (cylinder operating member).

Claims (1)

[Claims] 1. A cleavage device in which a hole 8 is bored in a rock 7 and an elastic pressure member 6 is fitted between the head 4 of a cylindrical bar 3 inserted into a tube 5 and the tube 5. Insert the rod 1 into the hole, connect the tube to the housing 9 of the hydraulic cylinder 2 and connect the cylindrical bar to the piston 10 of the hydraulic cylinder, and connect the tube of the hydraulic cylinder to the head. A rock cleavage method comprising cleaving a rock by compressing the pressure member in the axial direction and expanding it in the radial direction using a directional pressing force. 2. In the method described in claim 1,
A rock cleavage method comprising connecting a large number of cleavage rods 1 to a common power source 14 and simultaneously expanding the cleavage rods. 3. A cylindrical bar 3 inserted into a tube 5, a head 4 fixed to one end of the cylindrical bar, a sleeve-shaped elastic pressure member 6 fitted between the head and the tube, and a cylindrical bar 3 inserted into the tube. A rock cleavage tool comprising a hydraulic cylinder having a housing 9 connected thereto and a piston 10 connected to the other end of said bar. 4. In the tool described in claim 3,
A rock cleavage tool in which the pressure member is made of a deformable material that is hardly compressible in volume. 5. A rock cleavage tool according to claim 3 or 4, wherein the hydraulic cylinder is provided with a flow control valve 15 for maintaining compressive force against the pressure member.