U.S. patent application number 16/764395 was filed with the patent office on 2020-11-12 for hydraulic accumulator-based controllable pressure injection device and method.
This patent application is currently assigned to CHINA UNIVERSITY OF MINING AND TECHNOLOGY. The applicant listed for this patent is CHINA UNIVERSITY OF MINING AND TECHNOLOGY, XUZHOU ZHIRUN MINING EQUIPMENT SCIENCE AND TECHNOLOGY CO.,LTD. Invention is credited to Xinxia CUI, Hongxiang JIANG, Hongsheng LI, Wei LI, Songyong LIU, Gang SHEN, Haodong WANG, Xin ZHANG, Zhencai ZHU.
Application Number | 20200355031 16/764395 |
Document ID | / |
Family ID | 1000005004012 |
Filed Date | 2020-11-12 |
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United States Patent
Application |
20200355031 |
Kind Code |
A1 |
LIU; Songyong ; et
al. |
November 12, 2020 |
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.
Inventors: |
LIU; Songyong; (Xuzhou,
CN) ; ZHU; Zhencai; (Xuzhou, CN) ; WANG;
Haodong; (Xuzhou, CN) ; SHEN; Gang; (Xuzhou,
CN) ; JIANG; Hongxiang; (Xuzhou, CN) ; CUI;
Xinxia; (Xuzhou, CN) ; LI; Hongsheng; (Xuzhou,
CN) ; LI; Wei; (Xuzhou, CN) ; ZHANG; Xin;
(Xuzhou, CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CHINA UNIVERSITY OF MINING AND TECHNOLOGY
XUZHOU ZHIRUN MINING EQUIPMENT SCIENCE AND TECHNOLOGY
CO.,LTD |
Xuzhou
Xuzhou |
|
CN
CN |
|
|
Assignee: |
CHINA UNIVERSITY OF MINING AND
TECHNOLOGY
Xuzhou
CN
XUZHOU ZHIRUN MINING EQUIPMENT SCIENCE AND TECHNOLOGY
CO.,LTD
Xuzhou
CN
|
Family ID: |
1000005004012 |
Appl. No.: |
16/764395 |
Filed: |
September 21, 2018 |
PCT Filed: |
September 21, 2018 |
PCT NO: |
PCT/CN2018/106902 |
371 Date: |
May 15, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E21B 7/18 20130101 |
International
Class: |
E21B 7/18 20060101
E21B007/18 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 25, 2018 |
CN |
201810378319.6 |
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.times.1 mm chamfer, and the cone area is an 8.times.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.
Description
CROSS REFERENCES TO THE RELATED APPLICATIONS
[0001] 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
[0002] 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
[0003] 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.
[0004] 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
[0005] 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.
[0006] The present invention adopts the following technical
solutions to solve the technical problem:
[0007] 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.
[0008] A hydraulic accumulator-based controllable pressure
injection method, including the following steps:
[0009] 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;
[0010] 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;
[0011] c, monitoring pressure changes of the pressure cylinder and
an accumulator; and
[0012] 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.
[0013] 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
[0014] The present invention will be further described below with
reference to the accompanying drawings and the embodiments.
[0015] FIG. 1 is a structural schematic diagram according to one
embodiment of the present invention.
[0016] FIG. 2 is an enlarged view of part A in FIG. 1.
[0017] FIG. 3 is an enlarged view of part B in FIG. 1.
[0018] 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
[0019] 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.
[0020] 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.
[0021] 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.
[0022] 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.
[0023] 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.
[0024] 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.times.1 mm chamfer, and the cone area (6-1) is
an 8.times.8 mm chamfer.
[0025] A hydraulic accumulator-based controllable pressure
injection method according to an embodiment of the present
invention includes the following steps:
[0026] 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;
[0027] 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;
[0028] c, monitoring pressure changes of the pressure cylinder 4
and an accumulator 2; and
[0029] 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.
[0030] The high pressure fluid medium may be high pressure foam or
high pressure water.
[0031] 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.
[0032] 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.
* * * * *