HYDRAULIC ACCUMULATOR-BASED CONTROLLABLE PRESSURE INJECTION DEVICE AND METHOD

Abstract

A hydraulic accumulator-based controllable pressure injection device includes a pressure storage system, a pressure maintaining system, a sealing system, and an injection system. The pressure storage system includes a pressure cylinder front half portion, an annular piston and a middle connecting body. The pressure maintaining system includes an accumulator, a pressure cylinder rear half portion and a rear end cover. The sealing system includes a hydraulic propulsion cylinder, a propulsion piston, a front end cover, a sealing tube, a thickened end portion, and an expansion rubber tube. The injection system includes a hydraulic valve body and an injection gun tube. The hydraulic accumulator-based controllable pressure injection device quickly applies pressure to the bottom of a borehole in a hydraulic manner, so that rock experiences tensile failure, and the hard rock excavation efficiency is improved.

Description

CROSS REFERENCES TO THE RELATED APPLICATIONS

This application is the national phase entry of International Application No. PCT/CN2018/106902, filed on Sep. 21, 2018, which is based upon and claims priority to Chinese Patent Application No. 201810378319.6, filed on Apr. 25, 2018, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to a device for cracking rock with high pressure liquid flow, and in particular, to a hydraulic accumulator-based controllable pressure injection device and method, belonging to the technical field of mining roadway excavation engineering.

BACKGROUND

The 21st century is a period of great development of tunnels and underground space. With the development of economy and the improvement of science and technology of China, there are more and more excavation means for the underground space, but with the increasing demand for the underground space and the increase of excavation depth, the development and construction of the underground space are confronted with new difficulties and challenges. As the most important energy source in the energy system of China, the development and utilization of coal are dependent on the excavation of underground roadways and the excavation of deep rock masses. With the development of China's economic construction, the demand for coal has increased steadily, and the excavation of underground deep hard rock has become a major technical difficulty to be solved, which seriously restricts the coordinated development of coal mine production.

At present, the domestic rock roadway excavation mainly adopts a borehole-blasting method and a fully-mechanized excavating method, but the two excavation processes both have many problems such as low level of footage and low degree of mechanization. Especially, in hard rock excavation, the excavation efficiency is significantly reduced.

SUMMARY

In order to overcome the above-mentioned defects in the prior art, the present invention provides a hydraulic accumulator-based controllable pressure injection device and method, which can convert the pressure of a high pressure fluid into a cracking force acting on the inside of rock, thereby effectively improving the hard rock excavation efficiency.

The present invention adopts the following technical solutions to solve the technical problem:

A hydraulic accumulator-based controllable pressure injection device, including a pressure storage system, a pressure maintaining system, a sealing system, and an injection system. The pressure storage system includes a pressure cylinder front half portion, an annular piston and a middle connecting body, which are mounted on the same axis, the annular piston is located between a pressure cylinder and a hydraulic adjusting tube and dynamically sealed, the pressure cylinder front half portion is fixedly connected to an end portion of the middle connecting body, and a high pressure fluid inlet flow passage having both ends respectively communicating with the outside and an inner chamber of the pressure cylinder front half portion is provided in the middle connecting body. The pressure maintaining system includes an accumulator, a pressure cylinder rear half portion and a rear end cover, the pressure cylinder rear half portion and a rear end of the hydraulic adjusting tube are detachably connected to the rear end cover, respectively, and sealed, an outer end of the rear end cover is provided with the accumulator, and the accumulator is communicated to an inner chamber of the pressure cylinder rear half portion. The sealing system includes a hydraulic propulsion cylinder, a propulsion piston, a front end cover, a sealing tube, a thickened end portion, and an expansion rubber tube, the sealing tube sequentially penetrates through the axes of the front end cover and the propulsion piston, a rear end of the sealing tube and the propulsion piston are fixedly connected into a whole, the expansion rubber tube and a front end of the sealing tube are butted and coaxially connected, the sealing tube and the front end cover are dynamically sealed, the propulsion piston and the hydraulic propulsion cylinder are dynamically sealed, a front end of the hydraulic propulsion cylinder is detachably connected to a rear end of the front end cover and sealed, a rear end of the hydraulic propulsion cylinder is fixedly connected to the middle connecting body, and an oil inlet and outlet port having both ends respectively communicating with the outside and an inner chamber of the hydraulic propulsion cylinder is also provided in the middle connecting body. The injection system includes a hydraulic valve body and an injection gun tube, the hydraulic valve body is coaxially mounted inside a front port of the hydraulic adjusting tube in the pressure storage system and the two are dynamically sealed at front ends, the injection gun tube is coaxially sleeved inside the sealing tube and penetrates through the propulsion piston, the thickened end portion is coaxially and detachably connected to a front end of the injection gun tube, a rear end of the injection gun tube is fixedly connected to the middle connecting body, and a front end of the hydraulic valve body has a cone area fitting a groove at a rear end of the injection gun tube.

A hydraulic accumulator-based controllable pressure injection method, including the following steps:

a, inserting an injection gun tube into a rock borehole, and pushing, by a propulsion piston, a sealing tube to push an expansion rubber tube to a thickened end portion such that an outer diameter of the injection gun tube is enlarged to fit an inner wall of the rock borehole to form a sealed space at the bottom of the rock borehole;

b, starting a hydraulic valve body to fit a groove at a rear end of the injection gun tube, and feeding a high pressure fluid medium via a high pressure fluid inlet flow passage to form a high pressure area in a front section of a pressure cylinder;

c, monitoring pressure changes of the pressure cylinder and an accumulator; and

d, after a pressure reaches a predetermined value, reducing the pressure in a hydraulic adjusting tube to 0 gradually, when a pressure generated by the high pressure area against a cone area at a front end of the hydraulic valve body is greater than an oil path pressure in the hydraulic adjusting tube at a rear end, allowing the hydraulic valve body to slide backwards to be separated from the groove at the rear end of the injection gun tube, and allowing the high pressure fluid medium to instantaneously surge into the sealed space at the bottom of the rock borehole under own pressure and the thrust of an annular piston, where the pressure generated is sufficient to cause the rock to break from the inside.

Compared with the prior art, the hydraulic accumulator-based controllable pressure injection device and method of the present invention can realize breaking of hard rock under a lower pressure with high rock-breaking efficiency, safety and environmental protection by utilizing the characteristic that the tensile strength of the rock is far lower than the compressive strength. The device may replace a conventional borehole-blasting excavation mode, is easy to be combined with excavation equipment such as a heading machine and a rock drill, can realize underground exploitation and excavation by no one or few people when connected to electromechanical control equipment, and has the advantages of small scale, easy control and the like.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be further described below with reference to the accompanying drawings and the embodiments.

FIG. 1 is a structural schematic diagram according to one embodiment of the present invention.

FIG. 2 is an enlarged view of part A in FIG. 1.

FIG. 3 is an enlarged view of part B in FIG. 1.

In the figures, 1, rear end cover; 2, accumulator; 3, hydraulic adjusting tube; 4, pressure cylinder; 5, annular piston; 6, hydraulic valve body; 6-1, cone area; 7, middle connecting body; 7-1, high pressure fluid inlet flow passage; 7-2, oil inlet and outlet port; 8, hydraulic propulsion cylinder; 9, propulsion piston; 10, front end cover; 11, injection gun tube; 11-1, groove; 12, sealing tube; 13, expansion rubber tube; 14, thickened end portion.

DETAILED DESCRIPTION OF THE EMBODIMENTS

In order to make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. It is apparent that the described embodiments are a part of the embodiments of the present invention, and not all embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in the present invention without creative efforts fall within the scope of protection of the present invention.

For the sake of clarity of description, it is specifically stated that a “front” end, a “front” half portion or a “front” side mentioned in the present embodiment refers to a downward direction in FIG. 1, and “rear” is in line with an “upward” direction.

In the embodiment shown in FIG. 1 to FIG. 3, a hydraulic accumulator-based controllable pressure injection device for applying a cracking force in a rock borehole to break rock from the inside of the hole includes a pressure storage system, a pressure maintaining system, a sealing system, and an injection system, where the pressure storage system includes a pressure cylinder front half portion 4-2, an annular piston 5 and a middle connecting body 7, which are mounted on the same axis, the annular piston 5 is located between a pressure cylinder 4 and a hydraulic adjusting tube 3 and dynamically sealed, the pressure cylinder front half portion 4-2 is fixedly connected to an end portion of the middle connecting body 7, a high pressure fluid inlet flow passage 7-1 having both ends respectively communicating with the outside and an inner chamber of the pressure cylinder front half portion 4-2 is provided in the middle connecting body 7, a high pressure fluid medium enters the pressure cylinder 4 through the high pressure fluid inlet flow passage 7-1, and the annular piston 5 is pushed to move backwards to store the high pressure fluid medium; the pressure maintaining system includes an accumulator 2, a pressure cylinder rear half portion 4-1 and a rear end cover 1, the pressure cylinder rear half portion 4-1 and a rear end of the hydraulic adjusting tube 3 are detachably connected to the rear end cover 1, respectively, and sealed, an outer end of the rear end cover 1 is provided with the accumulator 2, and the accumulator 2 is communicated to an inner chamber of the pressure cylinder rear half portion 4-1; the accumulator 2 absorbs high pressure oil from the pressure cylinder 4, when the high pressure fluid medium at a front end of the annular piston 5 is injected, the accumulator 2 releases stored hydraulic oil to maintain the pressure of the pressure cylinder 4 not to drop drastically within a short time; and as the pressure in the pressure cylinder 4 rises to a set pressure, an oil pressure in the hydraulic adjusting tube 3 is reduced, the hydraulic valve body 6 moves backwards under the pressure of the high pressure fluid medium, and the high pressure fluid medium is injected from an injection gun tube 11. The sealing system includes a hydraulic propulsion cylinder 8, a propulsion piston 9, a front end cover 10, a sealing tube 12, a thickened end portion 14, and an expansion rubber tube 13, the sealing tube 12 sequentially penetrates through the axes of the front end cover 10 and the propulsion piston 9, a rear end of the sealing tube 12 and the propulsion piston 9 are fixedly connected into a whole, the expansion rubber tube 13 and a front end of the sealing tube 12 are butted and coaxially connected, the sealing tube 12 and the front end cover 10 are dynamically sealed, the propulsion piston 9 and the hydraulic propulsion cylinder 8 are dynamically sealed, the expansion rubber tube 13 can move along the axis with the propulsion piston 9, a front end of the hydraulic propulsion cylinder 8 is detachably connected to a rear end of the front end cover 10 and sealed, a rear end of the hydraulic propulsion cylinder 8 is fixedly connected to the middle connecting body 7 by welding or the like, an oil inlet and outlet port 7-2 having both ends respectively communicating with the outside and an inner chamber of the hydraulic propulsion cylinder 8 is also provided in the middle connecting body 7, and a backward pressure from the high pressure fluid medium at the front end presses the hydraulic oil into the accumulator through the annular piston 5 for storing the pressure in the system. The injection system includes a hydraulic valve body 6 and an injection gun tube 11, the hydraulic valve body 6 is coaxially mounted inside the hydraulic adjusting tube 3 in the pressure storage system and the two are dynamically sealed at front ends, and finally, the hydraulic valve body 6 can only be translated in a groove at the front end of the hydraulic adjusting tube 3, and cannot be moved out; and the injection gun tube 11 is coaxially sleeved inside the sealing tube 12 and penetrates through the propulsion piston 9, the thickened end portion 14 is coaxially and detachably connected to a front end of the injection gun tube 11, a rear end of the injection gun tube 11 is fixedly connected to the middle connecting body 7 by welding or the like, and the front end of the hydraulic valve body 6 has a cone area 6-1 fitting a groove 11-1 at a rear end of the injection gun tube 11. The hydraulic valve body 6 is used to open and close a communication state between the pressure cylinder 4 and the injection gun tube 11, and the start and stop control of the injection system is realized by the hydraulic adjusting tube 3. Preferably, the cone area 6-1 at the front end of the hydraulic valve body 6 fits the groove 11-1 at the rear end of the injection gun tube 11, but there is still a part of the cone area exposed to a high pressure fluid, and a backward thrust is generated for the hydraulic valve body 6. The annular piston 5 is dynamically sealed with the pressure cylinder 4 and the hydraulic adjusting tube 3 through a guide strip and a Glyd ring, respectively, so that the annular piston 5 is slidable between the hydraulic adjusting tube 3 and the pressure cylinder 4.

In the present embodiment, the pressure cylinder front half portion 4-2 and the end portion of the middle connecting body 7 are welded together. The pressure cylinder rear half portion 4-1 and the rear end cover 1 are connected by threads, and an O ring is provided therebetween for sealing. The hydraulic propulsion cylinder 8 is connected to the rear end of the front end cover 10 by threads, and an O ring is provided therebetween to ensure sealing of hydraulic oil. A guide strip and a step seal are provided between the front end cover 10 and the sealing tube 12 to ensure sealing of the hydraulic oil. The thickened end portion 14 is connected to the injection gun tube 11 by threads, and the hydraulic valve body 6 and the hydraulic adjusting tube 3 are dynamically sealed through a guide sleeve and a Glyd ring, so that the hydraulic valve body 6 is pushed by hydraulic oil in the tube to move forwards, and the cone area 6-1 at the front end of the hydraulic valve body 6 fits the groove 11-1 at the rear end of the injection gun tube 11 to form a sealed space in the pressure cylinder 4.

In order to buffer the annular piston 5, a raised circular ring is provided on an end face of the middle connecting body 7 facing the pressure cylinder 4, the raised circular ring is located in an inner chamber of the pressure cylinder 4, and the height of the raised circular ring can be 1 cm.

Preferably, the groove 11-1 at the rear end of the injection gun tube 11 and the cone area 6-1 at the front end of the hydraulic valve body 6 are both chamfers of 45 degrees. Furthermore, the groove 11-1 is a 1×1 mm chamfer, and the cone area (6-1) is an 8×8 mm chamfer.

A hydraulic accumulator-based controllable pressure injection method according to an embodiment of the present invention includes the following steps:

a, inserting an injection gun tube 11 into a rock borehole, pushing, by a propulsion piston 9, a sealing tube 12 to push an expansion rubber tube 13 to a thickened end portion 14 such that an outer diameter of the injection gun tube 11 is enlarged to fit an inner wall of the rock borehole to form a sealed space at the bottom of the rock borehole;

b, starting a hydraulic valve body 6 to fit a groove 11-1 at a rear end of the injection gun tube 11, and feeding a high pressure fluid medium via a high pressure fluid inlet flow passage 7-1 to form a high pressure area in a front section of a pressure cylinder 4;

c, monitoring pressure changes of the pressure cylinder 4 and an accumulator 2; and

d, after a pressure reaches a predetermined value, reducing the pressure in a hydraulic adjusting tube 3 to 0 gradually, when a pressure generated by the high pressure area against a cone area 6-1 at a front end of the hydraulic valve body 6 is greater than an oil path pressure in the hydraulic adjusting tube 3 at a rear end, allowing the hydraulic valve body 6 to slide backwards to be separated from the groove 11-1 at the rear end of the injection gun tube, and allowing the high pressure fluid medium to instantaneously surge into the sealed space at the bottom of the rock borehole under own pressure and the thrust of an annular piston 5, where the pressure generated is sufficient to cause the rock to break from the inside.

The high pressure fluid medium may be high pressure foam or high pressure water.

The controllable pressure injection of the device is characterized in that the hydraulic adjusting tube 3 is supplied with oil by a controllable hydraulic pumping station, and the magnitude of a pressure for injecting a fluid medium is controlled by setting different oil supplies.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention in any form. Any simple modifications and equivalent changes made to the above embodiments in accordance with the technical essence of the present invention fall into the scope of protection of the present invention.

Claims

1. A hydraulic accumulator-based controllable pressure injection device, comprising a pressure storage system, a pressure maintaining system, a sealing system, and an injection system, wherein

the pressure storage system comprises a pressure cylinder front half portion, an annular piston and a middle connecting body, which are mounted on a same axis, the annular piston is located between a pressure cylinder and a hydraulic adjusting tube and dynamically sealed, the pressure cylinder front half portion is fixedly connected to an end portion of the middle connecting body, and a high pressure fluid inlet flow passage having both ends respectively communicating with an outside and an inner chamber of the pressure cylinder front half portion is provided in the middle connecting body;

the pressure maintaining system comprises an accumulator, a pressure cylinder rear half portion and a rear end cover, the pressure cylinder rear half portion and a rear end of the hydraulic adjusting tube are detachably connected to the rear end cover, respectively, and sealed, an outer end of the rear end cover is provided with the accumulator, and the accumulator is communicated to an inner chamber of the pressure cylinder rear half portion;

the sealing system comprises a hydraulic propulsion cylinder, a propulsion piston, a front end cover, a sealing tube, a thickened end portion, and an expansion rubber tube, the sealing tube sequentially penetrates through a plurality of axes of the front end cover and the propulsion piston, a rear end of the sealing tube and the propulsion piston are fixedly connected into a whole, the expansion rubber tube and a front end of the sealing tube are butted and coaxially connected, the sealing tube and the front end cover are dynamically sealed, the propulsion piston and the hydraulic propulsion cylinder are dynamically sealed, a front end of the hydraulic propulsion cylinder is detachably connected to a rear end of the front end cover and sealed, a rear end of the hydraulic propulsion cylinder is fixedly connected to the middle connecting body, and an oil inlet and outlet port having both ends respectively communicating with the outside and an inner chamber of the hydraulic propulsion cylinder is also provided in the middle connecting body; and

the injection system comprises a hydraulic valve body and an injection gun tube, the hydraulic valve body is coaxially mounted inside the hydraulic adjusting tube in the pressure storage system and the hydraulic valve body and the hydraulic adjusting tube are dynamically sealed at front ends, the injection gun tube is coaxially sleeved inside the sealing tube and penetrates through the propulsion piston, the thickened end portion is coaxially and detachably connected to a front end of the injection gun tube, a rear end of the injection gun tube is fixedly connected to the middle connecting body, and a front end of the hydraulic valve body has a cone area fitting a groove at the rear end of the injection gun tube.

2. The hydraulic accumulator-based controllable pressure injection device according to claim 1, wherein the annular piston is dynamically sealed with the pressure cylinder and the hydraulic adjusting tube through a guide strip and a Glyd ring, respectively, so that the annular piston is slidable between the hydraulic adjusting tube and the pressure cylinder.

3. The hydraulic accumulator-based controllable pressure injection device according to claim 1, wherein the pressure cylinder front half portion and the end portion of the middle connecting body are welded together, the pressure cylinder rear half portion and the rear end cover are connected by a plurality of threads, and a plurality of O rings are provided therebetween respectively for sealing.

4. The hydraulic accumulator-based controllable pressure injection device according to claim 1, wherein a raised circular ring is provided on an end face of the middle connecting body facing the pressure cylinder, the raised circular ring being located in an inner chamber of the pressure cylinder.

5. The hydraulic accumulator-based controllable pressure injection device according to claim 1, wherein the hydraulic propulsion cylinder is connected to the rear end of the front end cover by a plurality of threads, an O ring is provided therebetween to ensure sealing of a hydraulic oil, and a guide strip and a step seal are provided between the front end cover and the sealing tube to ensure sealing of the hydraulic oil.

6. The hydraulic accumulator-based controllable pressure injection device according to claim 1, wherein the thickened end portion is connected to the injection gun tube by a plurality of threads, and the hydraulic valve body and the hydraulic adjusting tube are dynamically sealed through a guide sleeve and a Glyd ring.

7. The hydraulic accumulator-based controllable pressure injection device according to claim 1, wherein the groove at the rear end of the injection gun tube and the cone area at the front end of the hydraulic valve body are both chamfers of 45 degrees, and the groove is a 1×1 mm chamfer, and the cone area is an 8×8 mm chamfer.

8. The hydraulic accumulator-based controllable pressure injection device according to claim 1, wherein the rear end of the hydraulic propulsion cylinder is welded to the middle connecting body, and the rear end of the injection gun tube is fixed to the middle connecting body by welding.

9. A hydraulic accumulator-based controllable pressure injection method, comprising the following steps:

a, inserting an injection gun tube into a rock borehole, and pushing, by a propulsion piston, a sealing tube to push an expansion rubber tube to a thickened end portion such that an outer diameter of the injection gun tube is enlarged to fit an inner wall of the rock borehole to form a sealed space at a bottom of the rock borehole;

b, starting a hydraulic valve body to fit a groove at a rear end of the injection gun tube, and feeding a high pressure fluid medium via a high pressure fluid inlet flow passage to form a high pressure area in a front section of a pressure cylinder;

c, monitoring pressure changes of the pressure cylinder and an accumulator; and

d, after a pressure reaches a predetermined value, reducing the pressure in a hydraulic adjusting tube to 0 gradually, when a pressure generated by the high pressure area against a cone area at a front end of the hydraulic valve body is greater than an oil path pressure in the hydraulic adjusting tube at a rear end, allowing the hydraulic valve body to slide backwards to be separated from the groove at the rear end of the injection gun tube, and allowing the high pressure fluid medium to instantaneously surge into the sealed space at the bottom of the rock borehole under own pressure and a thrust of an annular piston, wherein the pressure generated is sufficient to cause a rock to break from an inside.

10. The hydraulic accumulator-based controllable pressure injection method according to claim 9, wherein the high pressure fluid medium is a high pressure foam or a high pressure water.

11. The hydraulic accumulator-based controllable pressure injection device according to claim 3, wherein the annular piston is dynamically sealed with the pressure cylinder and the hydraulic adjusting tube through a guide strip and a Glyd ring, respectively, so that the annular piston is slidable between the hydraulic adjusting tube and the pressure cylinder.

12. The hydraulic accumulator-based controllable pressure injection device according to claim 4, wherein the annular piston is dynamically sealed with the pressure cylinder and the hydraulic adjusting tube through a guide strip and a Glyd ring, respectively, so that the annular piston is slidable between the hydraulic adjusting tube and the pressure cylinder.

13. The hydraulic accumulator-based controllable pressure injection device according to claim 5, wherein the annular piston is dynamically sealed with the pressure cylinder and the hydraulic adjusting tube through a guide strip and a Glyd ring, respectively, so that the annular piston is slidable between the hydraulic adjusting tube and the pressure cylinder.

14. The hydraulic accumulator-based controllable pressure injection device according to claim 6, wherein the annular piston is dynamically sealed with the pressure cylinder and the hydraulic adjusting tube through a guide strip and a Glyd ring, respectively, so that the annular piston is slidable between the hydraulic adjusting tube and the pressure cylinder.

15. The hydraulic accumulator-based controllable pressure injection device according to claim 7, wherein the annular piston is dynamically sealed with the pressure cylinder and the hydraulic adjusting tube through a guide strip and a Glyd ring, respectively, so that the annular piston is slidable between the hydraulic adjusting tube and the pressure cylinder.

16. The hydraulic accumulator-based controllable pressure injection device according to claim 8, wherein the annular piston is dynamically sealed with the pressure cylinder and the hydraulic adjusting tube through a guide strip and a Glyd ring, respectively, so that the annular piston is slidable between the hydraulic adjusting tube and the pressure cylinder.