Note: Descriptions are shown in the official language in which they were submitted.
PNEUMATIC SELF-PROPELLED IMPACT ROCK BREAKING DEVICE
WITH THE ASSISTANCE OF ULTRA-HIGH-PRESSURE PULSED JET
FLOW
BACKGROUND OF THE INVENTION
Technical Field
The present invention relates to a pneumatic self-propelled impact rock
breaking
device with the assistance of an ultra-high-pressure pulsed jet flow, which
particularly
applies to drilling or breaking rock with a high Platts hardness coefficient.
Background
In 2015, the BP Statistical Yearbook of World Energy pointed out that China is
still
the world's largest energy consumer, which accounts for 23% of global
consumption and
61% of global net growth. Coal resource consumption accounts for 66.03% of
total
consumption. In the future for a long period of time, coal will have an
irreplaceable
position as China's primary energy source. Outline of China's National Plan
for Medium-
and Long-term Scientific and Technological Development (2006 to 2020) clearly
points
out that, there is an urgent need to strengthen the research on safe and
efficient mining
and utilization of coal resources, and it is explicitly required to focus on
ore mining
technologies for deep and complex strata.
At present, coal mining for deep and complex strata has gradually carried out.
Therefore, safe and efficient coal resource mining technology and equipment
for the deep
and complex strata are faced with high requirements and new challenges. As the
ground
stress increases, the elastic modulus, hardness and breaking strength of coal-
bearing rock
in the deep and complex strata also increase, and the uniaxial compressive
strength
reaches up to 150 MPa or above in most cases. Drilling of the coal-bearing
rock is a
prerequisite for efficient implementation of ore blasting, mining under
pressure relief,
roadway support, and other like projects. Problems such as low efficiency in
drilling of a
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hard coal-bearing rock and a large amount of dust directly constrain efficient
development of ore resources such as coal in the deep and complex strata.
Underground
drilling of the coal-bearing rock mainly adopts two manners: mechanical
cutting and a
mechanical impact. During rock breaking in the mechanical cutting manner, the
wear of a
cutting tool is serious and the consumption is high, and this manner is
usually used to cut
and break a coal-bearing rock with the Platts hardness coefficient f<8. Most
of the
coal-bearing rock can be broken in the mechanical impact manner, but this
manner has
such problems as severe wear and shedding of ball teeth, low efficiency in
rock breaking,
and a large amount of dust during operation in hard coal-bearing rock (f15),
greatly
reducing rock breaking ability and efficiency of the mechanical impact manner,
and
service life and reliability of the equipment. How to safely and efficiently
break the hard
coal-bearing rock has become the key issue and difficulty in the efficient
development of
ore resources such as coal in the deep and complex strata.
It has been proved that, the rock breaking ability of the cutting tool can be
enhanced
and its service life can be prolonged with the assistance of a high-pressure
water jet.
However, continuous high-pressure water jet consumes a lot of water, and a
large area of
stagnant water is produced in the workplace for mechanical breaking of the
coal-bearing
rock, making it difficult for the device to work normally. In the common rock
breaking
manner with the assistance of a continuous water jet, only a "water hammer
pressure" is
produced, which has a limited ability to impact on and break the rock. The
subsequent
"stagnation pressure" is low, such that it is difficult to aggravate internal
damage and
crack growth in the hard coal-bearing rock. Thus, the continuous water jet
fails to be
widely applied in breaking equipment for the hard coal-bearing rock. A pulsed
jet flow
has higher ability to impact on and break the coal-bearing rock than the
continuous water
jet. Due to a low-temperature impact and low water consumption of the pulsed
jet flow,
the wear rate and consumption of the ball teeth can be reduced, the service
life thereof
can be prolonged, and the working conditions of rock breaking depending on the
mechanical impact can be improved.
SUMMARY OF THE INVENTION
Invention objective: An objective of the present invention is to overcome the
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shortcomings in the prior art, and provide a pneumatic self-propelled impact
rock
breaking device with the assistance of an ultra-high-pressure pulsed jet flow.
The device
fundamentally integrates an ultra-high-pressure pulsed jet flow into a rock
breaking
process depending on a mechanical impact, thus solving the difficulty of
drilling and
breaking rock with a high Platts hardness coefficient.
To achieve the foregoing objective, the present invention adopts the following
technical solutions: A pneumatic self-propelled impact rock breaking device
with the
assistance of an ultra-high-pressure pulsed jet flow includes an air
compressor, an air tank,
a low-pressure water-feeding pump, an overflow valve, a pulsed solenoid valve,
a ball
valve, a water-air combined pipe, a water-air inlet connector, an impact
piston
acceleration chamber, a middle piston chamber, a front pressurized water
chamber, a
one-way valve, an impact drill bit, a spring, a stop collar, a middle piston,
an impact
piston, and an impact piston cushion, where
a front end of the front pressurized water chamber is provided with an end
cover, a
tail end of the front pressurized water chamber is connected to a front end of
the middle
piston chamber, a tail end of the middle piston chamber is connected to a
front end of the
impact piston acceleration chamber, and a tail end of the impact piston
acceleration
chamber is provided with the water-air inlet connector; a drill bit pilot hole
is opened in
the center of the end cover, several detritus filter notches are evenly
distributed around
the rim of the end cover, several alloy nozzle ball teeth and alloy ball teeth
are alternately
arranged on an external end face of the end cover, a pressurized water notch
is opened on
an internal end face of the end cover, and ultra-high pressure water channels
are opened
on the bottom of the pressurized water notch; the ultra-high pressure water
channel is
communicated with the alloy nozzle ball teeth, a connected water channel is
opened on a
side wall of the pressurized water notch, and an impact drill bit and a spring
are provided
in an inner cavity of the front pressurized water chamber; the head of the
impact drill bit
is fitted into the drill bit pilot hole, a middle portion of the impact drill
bit is fitted into the
inner cavity of the front pressurized water chamber, and the spring is
disposed on a tail
portion of the impact drill bit; a water channel IV is opened on the front
pressurized water
chamber, and is communicated with the connected water channel via the one-way
valve;
a groove I is provided on a front end of an inner cavity of the middle piston
chamber, and
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the stop collar is inserted into the groove I; the middle piston is provided
at the middle
portion of the inner cavity of the middle piston chamber, and a front end of
the middle
piston passes through the stop collar and contacts the spring; the stop collar
prevents the
middle piston from coming out of the middle piston chamber; a water channel
III is
opened on the middle piston chamber, and is communicated with the water
channel IV;
the impact piston is provided in an inner cavity of the impact piston
acceleration chamber,
and a water channel II is opened on the impact piston acceleration chamber and
is
communicated with the water channel III; a water inlet and an air inlet are
provided on an
external end face of the water-air inlet connector, a groove II is provided on
an internal
end face of the water-air inlet connector, and the impact piston cushion is
inserted into
the groove II; and a water channel I and an air channel are opened on the
water-air inlet
connector, wherein the water channel I is respectively communicated with the
water
channel II and the water inlet, and the air channel is respectively
communicated with the
inner cavity of the impact piston acceleration chamber and the air inlet; and
the water-air combined pipe comprises a high-pressure water pipe and an air
pipe;
the high-pressure water pipe is respectively communicated with the water inlet
and the
ball valve, and the ball valve is connected to the low-pressure water-feeding
pump via the
overflow valve; and the air pipe is communicated with the air inlet and the
pulsed
solenoid valve, and the pulsed solenoid valve is connected to the air
compressor via the
air tank.
Further, an alloy tip body is mounted on a front end of the head of the impact
drill
bit.
Further, a seal ring groove IV is opened on the periphery of the head of the
impact
drill bit, and a seal ring groove V is opened on the periphery of the middle
portion of the
impact drill bit.
Further, the end cover and the front pressurized water chamber are fixed
through
welding; and the front pressurized water chamber, the middle piston chamber,
the impact
piston acceleration chamber, and the water-air inlet connector are connected
with
magnetic bolts.
Further, an end face of the tail end of the impact piston acceleration chamber
is
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provided with a seal ring groove I, an end face of the tail end of the middle
piston
chamber is provided with a seal ring groove II, and an end face of the tail
end of the front
pressurized water chamber is provided with a seal ring groove III.
Further, a deep hole is provided in the impact piston, so as to reduce the
weight of
the impact piston, and the impact piston is made from aluminum alloy or
copper.
Further, a steel wire pipe is used as the air pipe, and the number of steel
wire layers
of the air pipe is not less than 2; and elastic rubber sleeves are wrapped
around the
high-pressure water pipe and the air pipe.
Beneficial effects: The present invention adopts a pneumatic driving manner;
has a
small overall size and a simple and compact structure; can be easily assembled
or
disassembled; produces large power; and achieves simple and reliable high-
pressure
water sealing. A mechanical impact with the assistance of an ultra-high-
pressure pulsed
jet flow can implement drilling or breaking of rock with a high Plats hardness
coefficient.
The ultra-high-pressure pulsed jet flow can greatly damage rock in advance,
reduce the
rock strength, and minimize the crush resistance of hard rock, thus reducing
the degree of
difficulty in breaking hard rock through a mechanical impact, and improving
the ability
and efficiency of the impact rock breaking device in drilling hard rock. The
ultra-high-pressure pulsed jet flow not only can suppress generation of dust
during rock
breaking, but also can enable mechanical ball teeth to break hard rock,
prolonging the
service life of the mechanical ball teeth and improving safe and efficient
development of
energy resources. Thus, the present invention has important social
significance for the
sustainable development of mines in China.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of a pneumatic self-propelled impact rock
breaking
device with the assistance of an ultra-high-pressure pulsed jet flow according
to the
present invention;
FIG. 2 is a front view of a front pressurized water chamber according to the
present
invention;
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FIG. 3 is a left view of the front pressurized water chamber according to the
present
invention;
FIG. 4 is a cross-sectional view of an impact drill bit according to the
present
invention;
FIG. 5 is a cross-sectional view of a middle piston chamber according to the
present
invention;
FIG. 6 is a cross-sectional view of an impact piston acceleration chamber
according
to the present invention;
FIG. 7 is a cross-sectional view of a water-air inlet connector according to
the
present invention; and
FIG. 8 is a front view of a water-air combined pipe according to the present
invention.
Description of reference numerals in the drawings: 1. Air compressor, 2. Air
tank, 3.
Low-pressure water-feeding pump, 4. Overflow valve, 5. Pulsed solenoid valve,
6. Ball
valve, 7. Water-air combined pipe, 8. Water-air inlet connector, 9. Impact
piston
acceleration chamber, 10. Middle piston chamber, 11. Front pressurized water
chamber,
12. One-way valve, 13. Impact drill bit, 14. Spring, 15. Stop collar, 16.
Middle piston, 17.
Magnetic bolt, 18. Impact piston, 19. Impact piston cushion, 7-1. High-
pressure water
pipe, 7-2. Elastic rubber sleeve, 7-3. Air pipe, 8-1. Water inlet, 8-2. Air
inlet, 8-3. Water
channel I, 8-4. Groove II, 8-5. Air channel, 8-6. Threaded hole I, 9-1. Seal
ring groove I,
9-2. Water channel II, 9-3. Threaded hole II, 10-1. Seal ring groove II, 10-2.
Water
channel III, 10-3. Groove I, 10-4. Threaded hole III, 11-1. Seal ring groove
III, 11-2.
Water channel IV, 11-3. Hole slot, 11-4. Connected water channel, 11-5.
Threaded hole
IV, 11-6. Ultra-high pressure water channel, 11-7. Alloy nozzle ball teeth, 11-
8. Alloy
ball teeth, 11-9. Detritus filter notch, 11-10. End cover, 11-11. Pressurized
water notch,
11-12. Drill bit pilot hole, 13-1. Alloy tip body, 13-2. Drill bar, 13-3. Seal
ring groove IV,
13-4. Seal ring groove V, and 18-1. Deep hole
DETAILED DESCRIPTION OF THE INVENTION
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The present invention is further explained below with reference to the
accompanying
drawings.
As shown in FIG. 1, a pneumatic self-propelled impact rock breaking device
with the
assistance of an ultra-high-pressure pulsed jet flow of the present invention
includes: an
air compressor 1, an air tank 2, a low-pressure water-feeding pump 3, an
overflow valve
4, a pulsed solenoid valve 5, a ball valve 6, a water-air combined pipe 7, a
water-air inlet
connector 8, an impact piston acceleration chamber 9, a middle piston chamber
10, a
front pressurized water chamber 11, a one-way valve 12, an impact drill bit
13, a spring
14, a stop collar 15, a middle piston 16, an impact piston 18, and an impact
piston
cushion 19. A front end of the front pressurized water chamber 11 is provided
with an
end cover 11-10, a tail end of the front pressurized water chamber 11 is
connected to a
front end of the middle piston chamber 10, a tail end of the middle piston
chamber 10 is
connected to a front end of the impact piston acceleration chamber 9, and a
tail end of the
impact piston acceleration chamber 9 is provided with the water-air inlet
connector 8.
As shown in FIGs. 1, 2, 5, 6, and 7, the end cover 11-10 and the front
pressurized
water chamber 11 are fixed through welding. A threaded hole IV 11-5 is opened
on an
end face of the tail end of the front pressurized water chamber 11, threaded
holes III 10-4
are opened respectively on end faces of the front end and the tail end of the
middle piston
chamber 10, threaded holes II 9-3 are opened respectively on end faces of the
front end
and the tail end of the impact piston acceleration chamber 9, and a threaded
hole I 8-6 is
opened on an end face of the front end of the water-air inlet connector 8, to
fixedly
connect the front pressurized water chamber 11, the middle piston chamber 10,
the
impact piston acceleration chamber 9, and the water-air inlet connector 8 with
magnetic
bolts 17. To ensure the impermeability at joints between the front pressurized
water
chamber 11, the middle piston chamber 10, the impact piston acceleration
chamber 9, and
the water-air inlet connector 8, the end face of the tail end of the impact
piston
acceleration chamber 9 is provided with a seal ring groove I 9-1, the end face
of the tail
end of the middle piston chamber 10 is provided with a seal ring groove 11 10-
1, and the
end face of the tail end of the front pressurized water chamber 11 is provided
with a seal
ring groove III 11-1. Seal rings are mounted in the foregoing seal ring
grooves
respectively.
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As shown in FIG. 1 to FIG. 4, a drill bit pilot hole 11-12 is opened in the
center of
the end cover 11-10, several detritus filter notches 11-9 are evenly
distributed around the
rim of the end cover 11-10, several alloy nozzle ball teeth 11-7 and alloy
ball teeth 11-8
are alternately arranged on an external end face of the end cover 11-10, a
pressurized
water notch 11-11 is opened on an internal end face of the end cover 11-10,
and
ultra-high pressure water channels 11-6 are opened on the bottom of the
pressurized
water notch 11-11. The ultra-high pressure water channel 11-6 is communicated
with the
alloy nozzle ball teeth 11-7. A connected water channel 11-4 is opened on a
side wall of
the pressurized water notch 11-11, and an impact drill bit 13 and a spring 14
are provided
in an inner cavity of the front pressurized water chamber 11. The head of the
impact drill
bit 13 is fitted into the drill bit pilot hole 11-12. An alloy tip body 13-1
is mounted on a
front end of the head of the impact drill bit 13, a middle portion of the
impact drill bit 13
is fitted into the inner cavity of the front pressurized water chamber 11, and
the spring 14
is disposed on a tail portion of the impact drill bit 13. To ensure the
impermeability at
joints between the impact drill bit 13, the end cover 11-10, and the front
pressurized
water chamber 11, a seal ring groove IV 13-3 is opened on the periphery of the
head of
the impact drill bit 13, a seal ring groove V 13-4 is opened on the periphery
of the middle
portion of the impact drill bit 13, and seal rings are mounted in the
foregoing seal ring
grooves respectively. A water channel IV 11-2 is opened on the front
pressurized water
chamber 11, and is communicated with the connected water channel 11-4 via the
one-way valve 12. The one-way valve 12 is mounted in a hole slot 11-3 on the
terminal
of the water channel IV 11-2, and is used to prevent backflow of water in the
front
pressurized water chamber 11.
As shown in FIG. 1 and FIG. 5, a groove I 10-3 is provided on a front end of
an inner
cavity of the middle piston chamber 10, and the stop collar 15 is inserted
into the groove I
10-3. The middle piston 16 is provided at a middle portion of the inner cavity
of the
middle piston chamber 10, and a front end of the middle piston 16 passes
through the
stop collar 15 and contacts the spring 14. The stop collar 15 prevents the
middle piston 16
from coming out of the middle piston chamber 10. A water channel III 10-2 is
opened on
the middle piston chamber 10, and is communicated with the water channel IV 11-
2. In
this embodiment, the section of the groove I 10-3 is a non-circular shape. In
this way,
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interference between the stop collar 15 and the water channel III 10-2 can be
prevented,
the stop collar 15 can be easily mounted, and the number of water channel
sealing
elements can be decreased.
As shown in FIG. 1 and FIG. 6, the impact piston 18 is provided in an inner
cavity of
the impact piston acceleration chamber 9. A deep hole 18-1 is provided in the
impact
piston 18, so as to reduce the weight of the impact piston 18. The impact
piston 18 is
made from aluminum alloy or copper. A water channel II 9-2 is opened on the
impact
piston acceleration chamber 9, and is respectively communicated with the water
channel
III 10-2 and water channel I 8-3.
As shown in FIG. 1 and FIG. 7, a water inlet 8-1 and an air inlet 8-2 are
provided on
an external end face of the water-air inlet connector 8, a groove II 8-4 is
provided on an
internal end face of the water-air inlet connector 8, and the impact piston
cushion 19 is
inserted into the groove II 8-4. A water channel I 8-3 and an air channel 8-5
are opened
on the water-air inlet connector 8, where the water channel I 8-3 is
respectively
communicated with the water channel II 9-2 and the water inlet 8-1, and the
air channel
8-5 is respectively communicated with the inner cavity of the impact piston
acceleration
chamber 9 and the air inlet 8-2.
As shown in FIG. 1 and FIG. 8, the water-air combined pipe 7 includes a
high-pressure water pipe 7-1 and an air pipe 7-3. The high-pressure water pipe
7-1 is
respectively communicated with the water inlet 8-1 and the ball valve 6. The
ball valve 6
is connected to the low-pressure water-feeding pump 3 via the overflow valve
4. The air
pipe 7-3 is communicated with the air inlet 8-2 and the pulsed solenoid valve
5, and the
pulsed solenoid valve 5 is connected to the air compressor 1 via the air tank
2. In this
embodiment, a steel wire pipe is used as the air pipe 7-3, where the number of
steel wire
layers of the air pipe 7-3 is not less than 2. An elastic rubber sleeve 7-2 is
wrapped
around the high-pressure water pipe 7-1 and the air pipe 7-3.
During operation of the air compressor 1, the air compressor 1 produces
compressed
air and injects the compressed air into the air tank 2 to form stable-pressure
compressed
air. The stable-pressure compressed air is turned into intermittent compressed
air through
the pulsed solenoid valve 5; and the intermittent compressed air is introduced
into the air
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pipe 7-3 of the water-air combined pipe 7 and the air channel 8-5 of the water-
air inlet
connector 8, and then injected into the impact piston acceleration chamber 9
to act upon
the impact piston 18. The impact piston 18 is driven by the compressed air to
impact on
the middle piston 16. The middle piston 16 impacts on the spring 14 and the
impact drill
bit 13, to propel the impact drill bit 13 to break rock. During operation of
the
low-pressure water-feeding pump 3, water with a certain pressure is introduced
into the
overflow valve 4, the ball valve 6, the high-pressure water pipe 7-1 of the
water-air
combined pipe 7, the water channel I 8-3 of the water-air inlet connector 8,
the water
channel II 9-2 of the impact piston acceleration chamber 9, the water channel
III 10-2 of
the middle piston chamber 10, the water channel IV 11-2 of the front
pressurized water
chamber 11, the one-way valve 12, and the connected water channel 11-4
successively,
and then enters the pressurized water notch 11-11 of the end cover 11-10. When
the air
compressor 1 and the low-pressure water-feeding pump 3 operate at the same
time, under
the impact, the impact drill bit 13 instantaneously increases the pressure of
the water in
the pressurized water notch 11-11, and an ultra-high-pressure pulsed jet flow
is then
formed via the alloy nozzle ball teeth 11-7 to impact on and break the rock.
While the
pressure of the water in the pressurized water notch 11-11 is instantaneously
increased,
the mutually connected end cover 11-10, front pressurized water chamber 11,
middle
piston chamber 10, and impact piston acceleration chamber 9 are subjected to a
forward
force to produce a feed speed, to propel the alloy nozzle ball teeth 11-7 and
the alloy ball
teeth 11-8 that are mounted on the end cover 11-10 to impact on and break the
rock.
During rock drilling by use of the pneumatic self-propelled impact rock
breaking
device with the assistance of an ultra-high-pressure pulsed jet flow of the
present
invention, the impact piston 18 instantaneously accelerates under the effect
of the
compressed air to produce a linear speed, and then impacts on the middle
piston 16 to
endow the middle piston with the impact and speed of certain magnitude. The
middle
piston 16 impacts on the spring 14 and the impact drill bit 13, to propel the
impact drill
bit 13 to break the rock. The low-pressure water-feeding pump 3 produces water
with a
certain pressure. The water is then introduced into the pressurized water
notch 11-11 of
the end cover 11-10 through the high-pressure water pipe 7-1 of the water-air
combined
pipe 7, the water channel I 8-3 of the water-air inlet connector 8, the water
channel II 9-2
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of the impact piston acceleration chamber 9, the water channel III 10-2 of the
middle
piston chamber 10, the water channel IV 11-2 of the front pressurized water
chamber 11,
and the one-way valve 12. During rock breaking by means of a mechanical
impact, while
the middle piston 16 impacts on the spring 14 and the impact drill bit 13, the
impact drill
bit 13 instantaneously increases the pressure of the water in the pressurized
water notch
11-11 under the impact, and then the water is urged to pass through the ultra-
high
pressure water channel 11-6, to form an instantaneous ultra-high-pressure
pulsed jet flow
via the alloy nozzle ball teeth 11-7. The ultra-high-pressure pulsed jet flow
can break in
advance the rock beyond an action range of the impact drill bit 13. While the
impact drill
bit 13 instantaneously increases the pressure of the water which is in the
pressurized
water notch 11-11, the mutually connected end cover 11-10, front pressurized
water
chamber 11, middle piston chamber 10, and impact piston acceleration chamber 9
are
subjected to a forward force, to propel the alloy nozzle ball teeth 11-7 and
the alloy ball
teeth 11-8 to impact on and break the rock.
The spring 14 is used to release a compressed elastic potential to reversely
act on the
middle piston 16 and the impact piston 18. After the pulsed solenoid valve 5
cuts off
supply of the compressed air, the impact piston 18 moves in a reverse
direction. When
the pulsed solenoid valve 5 recovers the supply of the compressed air, the
impact piston
18 makes a forward impact motion again, that to implement impact rock breaking
by the
impact drill bit 13, the alloy nozzle ball teeth 11-7, and the alloy ball
teeth 11-8 with the
assistance of a continuous ultra-high-pressure pulsed jet flow.
The above merely describes preferred embodiments of the present invention. It
should be noted that, several improvements and modifications may be made by
persons
of ordinary skill in the art without departing from the principle of the
present invention,
and these improvements and modifications should also be considered within the
protection scope of the present invention.
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