JPH04312692A - Ground boring method and device therefor - Google Patents

Abstract

PURPOSE:To bore a hole into the ground while injecting bubbles in a method for boring the hole into the ground and a device thereof. CONSTITUTION:A boring drill 2 provided to the front end of a drill 1 is such that a plurality of relay rods 5 are connected to a shunk rod 3 connected to the drill 1 through a shaft and that a bit 6 is screwed and fixed to the front end of the relay rods of the foremost end. Distribution holes 3a and 5a are formed in the centers of the rods 3 and 5 and, at the same time, the peripheral, surface of the shunk rod 3 is connected to a junction equipment 14 connected to a compressed air supply equipment 11 and a foaming agent solution supply equipment 12 through a swivel joint 9. The bit 6 has a tapered boring blade 6a on the front end thereof as a unit, injection ports 6a and 6c connected to the distribution hole 5a straightly are formed inside the hole, and a plurality of foaming uneven grooves 6d are formed on the peripheral surface of the rear of the blade 6a.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for drilling holes in the ground while blowing out air bubbles.

0002

2. Description of the Related Art In mountain tunnel construction, etc., a hole is drilled through a ground made of hard rock, etc., and the inside of the hole is blasted to crush it while excavating, or rock bolts for fixing are embedded. Drilling work involves attaching a drilling drill with a bit attached to the rod end to a rock drilling machine, and transmitting rotation and percussion motion to the bit to drill into the ground by impact drilling. It is discharged from between the outer periphery of the drilling drill and the hole. Conventionally, air or water was injected in parallel with the drilling process to cool the drill, prevent dust, and promote sludge removal, but this had the following problems.

[0003] In other words, when water is used, there are problems such as sludge turning into mud and footing becoming muddy, and in sandstone, breccia, etc., the hole wall is blocked by the impact and flushing water during drilling.
The jamming caused the drilling drill to become jammed, resulting in a drop in work efficiency due to drill breakage and the inability to drill holes. Also,
Increasing the amount of air caused problems such as cooling and dust. In addition, rough holes in the perforated walls impair the loading of gunpowder, the effectiveness of blasting, and the anchorage of rock bolts.

[0004] Therefore, the use of air bubbles has been studied for the purpose of preventing the generation of dust, preventing siltation, and at the same time making the perforation wall self-supporting.
No. 84, Japanese Unexamined Patent Publication No. 2-232496 (International Classification: E21C 7/06), etc., disclose a method and an apparatus for drilling holes while turning the cutting powder into a slurry by ejecting air bubbles from the tip of the bit. However, these methods and devices have the following problems.

[0005]

[Problem to be Solved by the Invention] In other words, in all of these methods, air bubbles or a mixture of air bubbles and compressed air are forced into a long and narrow circulation hole in the bit, but when air bubbles become air bubbles, their viscosity increases extremely. Therefore, it becomes difficult to pass through the flow holes, and a considerably high pressure is required to supply the bubble-forming material. However, most air compressors operate at low pressure, and the amount of material supplied and discharge pressure for creating bubbles is low, resulting in insufficient bubble formation and no effective effect.

[0006] The present invention solves the above problems, and provides a ground drilling method and device that can supply a sufficient amount of air bubbles from near the tip of the bit even when the air is fed under low pressure. The purpose is to

[0007]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a ground drilling method in which a gas-liquid two-phase fluid of a foaming agent solution and compressed air is pumped to the tip of a bit of a drilling drill. By creating a turbulent flow by applying resistance to the ejection of the gas-liquid two-phase fluid at the outer periphery near the spout at the tip of the bit, the bubbles generated by the gas-liquid two-phase fluid are mixed into the excavated sludge. It is characterized by doing so.

[0008] The ground drilling device also includes a compressed air supply device and a foaming agent solution supply device connected to a flow hole formed inside the drilling drill via a confluencer, and a tip of the drilling drill. It is characterized by comprising a plurality of concavities and convexities that serve as resistors formed on the outer circumferential portion near the jet nozzle that is open to the periphery. The merging vessel may be constituted by a spiral tube to which the compressed air supply device and the foaming agent solution supply device are connected at one end side.

[0009]

[Operation] According to the above-described drilling method and device, the foaming agent solution and compressed air supplied through the confluencer into the hollow part of the drilling drill are fed under pressure as a gas-liquid two-phase fluid, and A turbulent flow is created due to the resistance encountered when passing between the unevenness of the groove and the randomly arranged soil particles of the cutting sludge, which causes extremely good foaming and the formation of bubbles. The cutting waste mixed with air bubbles becomes highly fluid and is easily discharged from the narrow perforation to the face side.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a punching device according to the present invention. In the figure, a drilling drill 2 installed at the tip of a rock drilling machine 1 connects a plurality of relay rods 5 via joints 4 to a shank rod 3 that is pivoted to the rock drilling machine 1. A bit 6 is screwed and fixed to the tip of the bit 5. The rock drilling machine 1 includes a motor 7 for driving the rotation of the shank rod 3 and a striking device 8 facing the rear end of the shank rod 3, and transmits rotation and percussion motion to the drilling drill 2.

Communication holes 3a and 5a are formed at the center of the shank rod 3 and each relay rod 5, and a swivel joint 9 is arranged on the outer periphery of the shank rod 3. This swivel joint 9 has
A hose 10 is connected, and a confluencer 14 is connected to the base side of the hose 10. Then, in the merger 14,
An air compressor 11 (compressed air supply device) is connected through a flow rate adjustment valve TA, and a foaming agent solution tank 12 (foaming agent solution supply device) is connected through a flow rate adjustment valve TB and a pump P.

The foaming agent solution tank 12 stores a foaming agent solution which is made by adding a small amount of thickener to a 1 to 3% aqueous solution of a foaming agent such as a surfactant to increase the viscosity. There is. Details of the merger 14 are shown in FIG. 2. The confluencer 14 shown in the same figure is composed of a joint part 14a to which the flow rate adjustment valves TA and TB are connected, and a spiral tube 14b, and it converts the foaming agent solution and compressed air into a gas-liquid two-phase fluid. It has a structure that prevents compressed air from leading when pumping. In this case, in order to more reliably prevent the compressed air from leading, the foaming agent solution and the compressed air can be alternately merged by controlling the air compressor 11, the pump P, or the flow rate adjustment valves TA and TB. It is only necessary to send it to the device 14.

The foaming agent solution and compressed air are converted into a gas-liquid two-phase fluid in a confluencer 14, and pass through a hose 10 and a swivel joint 9 to flow holes 3a and 5a formed in each rod 3 and 5. is supplied to the bit 6 side in a state where it is easy to foam.

As shown in FIG. 3, the bit 6 has a tapered hole-drilling tool 6a integrally provided at its tip. A spout 6b and a plurality of spout ports 6c branching diagonally outward from the cutter 6a are formed, and a plurality of uneven grooves 6d for foaming are formed on the rear outer periphery of the cutter 6a.

In the above configuration, as shown in FIG.
When the gas-liquid two-phase fluid is ejected from the ejection port 6c, the ejected fluid passes through the gap between the hole wall of the perforation E1 and the randomly arranged soil particle group E2 of the cutting sludge, and then enters the groove portion 6.
d and tries to escape to the face side due to the ejection pressure,
Sudden resistance is encountered in these gaps, and the turbulent state caused by this resistance causes efficient foaming and generation of bubbles.

In this case, even if a thickener is added, the viscosity of the foaming agent solution is extremely low at 10 to several hundred centipoise in the non-foamed state, but it is viscous at several thousand to 10,000 centipoise in the foamed state. It becomes bubbles, and a sufficient amount of bubbles can be discharged depending on the source pressure at the time of supply. The air bubbles thus generated mix with the drilling sludge and are discharged to the face side through the perforation E1 due to the excess air pressure ejected when the air bubbles are formed. The discharged mixture of air bubbles and sludge loses almost all fluidity by adding an antifoaming agent or allowing the air bubbles to disappear naturally, and is disposed of as normal sludge.

[0017]

Effects of the Invention As explained in detail through the embodiments above, in the ground drilling method and device according to the present invention, the foaming agent solution and the compressed Air is pumped as a gas-liquid two-phase fluid, ejects from the tip of the bit, and when it passes through the unevenness of the groove and the randomly arranged groups of soil particles in the cutting sludge, a turbulent flow state occurs and foaming occurs. Air bubbles are generated, and the generated air bubbles and cutting waste are mixed during drilling with the bit, increasing fluidity and making it easier to be discharged to the face side. For this reason,
Even if the pumping pressure is low, a sufficient amount of air bubbles can be discharged onto the perforation surface, which is suitable for preventing the generation of dust and siltation, and at the same time making the perforation wall self-supporting.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an outline of a ground drilling device according to the present invention.

FIG. 2 is an enlarged explanatory diagram of the merger in FIG. 1;

FIG. 3 is an enlarged sectional view of the bit portion of FIG. 1;

FIG. 4 is an enlarged cross-sectional view in a drilling state.

[Explanation of symbols]

1. Jackhammer 2 Drill for drilling holes 3 Shank rod 5 Relay rod 3a, 5a, circulation hole 6 bits 6a Cutting tool 6b, 6c spout 9 Swivel joint 11 Air compressor 12 Foaming agent solution tank 14 Combiner E1 Drilling E2 Soil particles from excavation waste

Claims (3)

[Claims] 1. A gas-liquid two-phase fluid of a foaming agent solution and compressed air is fed under pressure to the tip of a bit of a drilling drill, and the gas-liquid two-phase fluid is jetted out at the outer circumference near the spout at the tip of the bit. A ground drilling method, characterized in that the air bubbles formed by foaming the gas-liquid two-phase fluid are mixed into the excavated waste by applying resistance to the air and creating turbulent flow. 2. A compressed air supply device and a foaming agent solution supply device connected to a communication hole formed inside a drilling drill via a confluencer, and a jetting port opened at the tip of the drilling drill. 1. A ground drilling device comprising: a plurality of projections and depressions serving as a resistor formed on an outer circumferential portion in the vicinity of the ground drilling device. 3. The ground drilling apparatus according to claim 2, wherein the confluencer is constituted by a spiral tube to which the compressed air supply device and the foaming agent solution supply device are connected at one end side.