KR102015668B1

KR102015668B1 - Pressurized fluid flow system for a reverse circulation down-the-hole hammer and hammer thereof

Info

Publication number: KR102015668B1
Application number: KR1020130073660A
Authority: KR
Inventors: 하이메 안드레스 아로스
Original assignee: 드릴코 툴즈 에스. 에이.
Priority date: 2013-06-26
Filing date: 2013-06-26
Publication date: 2019-08-28
Also published as: KR20150001052A

Abstract

The pressurized fluid flow system for the reverse circulating perforated hammer includes a cylindrical and cylindrical control tube disposed coaxially between the outer casing and the piston of the hammer and between the piston and the sample tube, respectively. The two chambers help to supply and discharge the pressurized fluid, respectively, into and out of the front and rear chambers exerting a work on the piston, wherein the two chambers are formed by central grooves in the inner surface portions of the piston. And an ejection chamber formed by one or more grooves in the inner chamber and the inner surface portion of the outer casing that are permanently connected to the source portion of the pressurized fluid and in permanent communication with the bottom of the hole. The flow of pressurized fluid into the work chambers is respectively controlled by the overlap of some of the outer surface portions of the sample tube and some of the outer surface portions of the control tube with the other portions of each inner sliding surface portion of the piston, while The flow of pressurized fluid discharged from the chambers is controlled by the overlap or relative position of the outer sliding surface portions of the piston with the inner surface portion of the cylinder. The hammer provided with such a system has one or more end discharge ports connected to respective longitudinal discharge channels formed on the outer surface portion of the front end of the outer casing.

Description

PRESSURIZED FLUID FLOW SYSTEM FOR A REVERSE CIRCULATION DOWN-THE-HOLE HAMMER AND HAMMER THEREOF}

The present invention generally includes a pressurized fluid flow system for impact devices operating with pressurized fluids, specifically down-the-hole (DTH) hammers and more specifically for reverse-circulating DTH hammers and the above systems. One is about DTH hammer.

DTH hammers actuated by pressurized fluid are formed in the cylindrical outer casing, the rear sub for connecting the hammer to the source portion of the pressurized fluid, the drill bit located at the foremost end to perform the drilling function and the inside of the hammer and at both ends of the piston Characterized by including a piston which generates a reciprocating motion due to a change in the pressure of the pressurized fluid contained in the two main work chambers, the front chamber and the rear chamber located in the field. The reciprocating motion of allows to transfer energy from the pressurized fluid to the rock with each impact of the piston on the drill bit.

The thermodynamic cycle of the hammer develops according to the reciprocating motion of the piston from the point of the stroke where the piston is in contact with the drill bit (known as the impact position) to the rearmost point of the stroke as the hammer operates. Thus, as the piston moves, the front and rear chambers are supplied with alternating and periodic pressurized fluid, the same is discharged, or undergoes an expansion or compression process according to the direction of the piston movement, where the chamber is firmly The closure causes the volume enclosed inside the chamber to increase or decrease respectively. The transition from one state to the other is independent of each chamber and is controlled by the position of the piston relative to the other parts of the hammer in such a way that the piston itself functions as a valve as well as an impact member.

In reverse circulation drilling, a double walled rod formed by two concentric pipes of an inner pipe or a sampling tube and an outer pipe is used. The extension of the sampling tube drill bit along the center of the hammer to form a continuous central passageway along the center of the hammer to enable to collect rock cuts and soil samples and move them to the ground surface through the center of the drill string. To the rear sub.

The hammer can be operated in two modes. In the first mode or drilling mode, pressurized fluid is supplied to the hammer to generate reciprocation of the piston, where the piston impacts the drill bit at the end of each cycle, so that the front end of the drill bit drills the rock. The rock cuttings are discharged to the ground by the pressurized fluid discharged to the bottom of the hole. In the second mode or flushing mode, the drill string and hammer are lifted by the drill rig such that the drill bit is out of contact with the rock and all the pressurized fluid does not pass through the hammer cycle, ie the reciprocation of the piston. It is released through the hammer directly to the bottom of the hole for cleaning purposes without interrupting movement.

There are many other types of reversed DTH hammers available for drilling and sample recovery. In general, three methods are used to control the supply of pressurized fluid to the front and rear chambers: 1) the use of a fluid passage formed between the outer surface of the cylinder and the inner surface of the outer casing, wherein the cylinder The part is mounted inside the outer casing which is coaxial with the piston; 2) the use of a feed chamber formed inside the outer casing which interacts with the grooves in the outer sliding surface portions of the piston and the passages in the outer casing as the piston reciprocates; And 3) use of a feed tube to form a feed chamber inside the piston, where the feed tube interacts with grooves in the inner or center hole side surfaces of the piston as the piston reciprocates. On the other hand, the ejection of the pressurized fluid from the front chamber is generally controlled by a smaller diameter piston front that interacts with a foot valve or piston guide mounted to the drill bit. Likewise, the discharge of pressurized fluid from the rear chamber is generally controlled by the air guide portion or the front end of the feed tube disposed on the rear portion of the rear chamber.

Generally, in order to convey the pressurized fluid from the rear end of the drill bit to its front end, the sprinkling on the inner surface of the driver sub and the ring or sleeve acting cooperatively with the sealing member act as pressurized A few channels are formed in the outer surface of the drill bit that form enclosed passages to release fluid to the periphery of the front end of the drill bit. The pressurized fluid may also escape from the intermediate point in the drill bit through a hole in the driver sub through a passage formed between the outer surface of the driver sub and the inner surface of the sealing ring. Alternatively, the pressurized fluid may deviate from the intermediate point through longitudinal holes formed on the head portion of the drill bit.

One type of reverse circulation DTH hammer is proposed in US Pat. No. 7,921,941 (B2) which proposes a new method of controlling the supply of pressurized fluid to the front and rear chambers and releasing the pressurized fluid from them. Specifically, the cylindrical portion is disposed coaxially between the outer casing and the piston and the feed chamber is disposed longitudinally in series with the discharge chamber, wherein all these chambers are each grooves in the inner surface portion of the outer casing. It is formed by the parts, internally delimited by the outer surface portion of the cylinder, and separated by the partitioning wall. The supply chamber is permanently connected to the source portion of the pressurized fluid to supply pressurized fluid to the front and rear chambers of the hammer, while the discharge chamber is connected to the bottom of the hole to discharge the pressurized fluid from the front and rear chambers. Permanently communicate. A set of fluid conducting means is provided to the piston to direct the flow of pressurized fluid from the supply chamber to the front and rear chambers and out of the chambers. In a second embodiment of the '941 patent, an inner chamber is provided between the piston and the sampling tube for more efficient filling of the chambers. The inner chamber is formed by a groove in the inner surface portion of the piston and is permanently connected to the supply chamber.

In the same patent above, end discharge ports are provided in the front end portion of the outer casing to discharge the pressurized fluid from the discharge chamber and to carry it to the peripheral region of the front end of the drill bit. These end release ports are aligned side by side with respective longitudinal channels formed along the outer surface of the outer casing. In addition, both the end release ports and the longitudinal channels are covered by a shroud or outer sealing sleeve.

That is, the control of the flow of pressurized fluid in and out of the front and rear chambers is simplified and the thrust regions in the piston allow for better thrust of energy to the rock thanks to the use of "blind" passages in the piston. Maximized for transmission, thus improving the hammer's deep drilling capacity. In addition, a simpler and more robust bit design is provided in contrast to other known reverse circulation DTH hammers where the release of the pressurized fluid to the barracks is achieved by a more centrally located fluid guide means.

Notwithstanding the advantages of the '941 patent mentioned above, it may be desirable to integrate these with the following improvements:

Providing a structurally simpler pressurized fluid flow system and hammer to reduce manufacturing costs; And

To provide a firmer piston for the hammer to operate at higher pressures and to deliver higher energy to the rock without the risk of catastrophic failure of the piston.

In a first aspect of the invention, a pressurized fluid flow system has been developed for a reverse circulating DTH hammer, which hammer is a cylindrical outer casing, a rear sub, which is attached to the rear end of the casing and connected to the sove of the pressurized fluid, A center through piston slidably and coaxially disposed inside the outer casing, a drill bit slidably mounted to the front end of the hammer on the driver sub, and coaxially disposed inside the outer casing and passing through the center hole of the piston A sample tube extending from the rear sub to the drill bit,

The pressurized fluid flow system

A cylindrical portion disposed coaxially between the outer casing and the piston and extending from the rear sub to the drill bit guide portion;

A cylindrical control tube disposed coaxially between the piston and the sample tube, extending forwardly from the rear sub and coupled to the rear sub and having pressurized fluid inlet means connected to an annular passage formed between the control tube and the sample tube; And

Two chambers to help supply and discharge the pressurized fluid, respectively, into and out of the work chambers: one in the inner chamber and the inner surface of the outer casing formed by a central groove in the inner surface of the piston The above grooves preferably comprise a discharge chamber formed by one annular groove.

These components have the following configuration:

The outer surface portions of the sample tube comprise grooved front and rear portions, and a central control portion between them;

The cylindrical control tube includes a front end control outer surface portion and a grooved rear end outer surface portion;

The discharge chamber is delimited by the outer surface portion of the cylinder and the inner surface portion of the outer casing; And

The inner chamber is ranged on one side by the outer surface portions of the sample tube or by the outer surface portions of the control tube and on the other side by the inner surface portions of the piston depending on the position of the piston during operation of the hammer. It is decided.

The present invention provides a source of fluid in which the pressurized fluid is permanently filled and the inner chamber is pressurized through an annular passage formed between the control tube and the sample tube to supply pressurized fluid to the front and rear chambers of the hammer. It is characterized by being permanently connected to wealth. To this end, the pressurized fluid flow system of the present invention has a front annular supply passage formed in an overlap portion between the front inner sliding surface portion of the piston and the grooved front end outer surface portion of the sample tube, and the rear annular supply passage is formed of the piston. Each is configured to be formed in an overlapping portion between the rear inner sliding surface portion and the grooved rear end outer surface portion of the control tube.

On the other hand, the discharge chamber is in permanent communication with the bottom of the hole drilled by the hammer to discharge pressurized fluid from the front and rear chambers of the hammer into the hole.

During the step of supplying pressurized fluid to the front chamber, the inflow of the pressurized fluid is controlled by the overlap of the central control outer surface of the sample tube with the front inner sliding surface of the piston. Likewise, during the step of supplying pressurized fluid to the rear chamber, the inflow of the pressurized fluid is controlled by the overlap of the front end control outer surface portion of the control tube with the rear inner sliding surface portion of the piston. Using this form of inflow control into the front and rear chambers, more efficient filling of the front and rear chambers is achieved every cycle of the hammer and the size of the passive volume in both chambers is reduced.

In addition, the flow of pressurized fluid discharged from the front and rear chambers is controlled only by the overlap or relative position of the outer sliding surface portions of the piston with the inner surface portion of the cylinder. There is a front set of pressurized fluid discharge pass ports for discharging the pressurized fluid from the front chamber to the discharge chamber and a rear set of pressurized fluid discharge pass ports for discharge the pressurized fluid from the rear chamber to the discharge chamber. Is in the cylinder. On the other hand, in order to channel the pressurized fluid from the inner chamber to the front and rear chambers of the hammer and from these front and rear chambers to the discharge chamber, no conduits or passages are processed in the piston, thus further adding the piston. Makes it stronger and makes hammers cheaper

Furthermore, as the pressurized fluid flow system of the present invention has a discharge chamber adjacent to the inner surface portion of the outer casing, the pressurized fluid flow is diverted out of the outer casing through one or more end discharge ports perforated in the casing wall and This makes it possible to discharge the pressurized fluid to the peripheral area of the front end of the drill bit.

In a second aspect of the invention, the above-mentioned end release out of the outer casing by having the improved pressurized fluid flow system described above and with pressurized fluid from the discharge chamber along the sides of the front end portion of the outer casing A reverse circulation DTH hammer is provided which is characterized by ejecting through the ports.

Preferably, the end release ports are connected to respective longitudinal discharge channels formed on the outer surface portion of the front end portion of the outer casing. End discharge ports and longitudinal discharge channels are both covered by a sealing member, such as a shroud or outer sealing sleeve, to direct pressurized fluid to the peripheral region of the front end of the drill bit and to form rock cuts along the center of the hammer. Create a pressurized fluid flow across the front face of the drill bit to draw towards the interior of the continuous central passage.

In the following, to facilitate understanding of the foregoing ideas, the present invention will be described with reference to the accompanying drawings.

According to the present invention, it is possible to provide a structurally simpler pressurized fluid flow system and hammer to reduce the manufacturing cost, the hammer operates at higher pressure and higher energy risk of catastrophic failure of the piston It can provide a more robust piston for delivery to rock.

In the drawings:
Figure 1 shows a longitudinal cross-sectional view of the reverse circulation DTH hammer of the present invention, in detail the outer casing when the pressurized fluid is supplied to the front chamber and the rear chamber is discharging the pressurized fluid to the bottom of the hole, The placement of the piston relative to the cylinder, drill bit, control tube and sample tube is shown.
Figure 2 shows a longitudinal cross-sectional view of the reverse circulation DTH hammer of the present invention, in detail the outer casing when the pressurized fluid is supplied to the rear chamber and the front chamber is discharging the pressurized fluid to the bottom of the hole, The placement of the piston relative to the cylinder, drill bit, control tube and sample tube is shown.
Figure 3 shows a longitudinal cross-sectional view of the reverse-circulation DTH hammer of the present invention, specifically showing the arrangement of piston and drill bits for the outer casing, cylinder, control tube and sample tube when the hammer is in flushing mode. Indicates.
Figure 4 shows an isometric view of the reverse-circulation DTH hammer of the present invention with a cut outer casing, where the pressurized fluid is supplied to the front chamber and the rear chamber is discharging the pressurized fluid to the bottom of the hole. It shows the arrangement of the internal parts of the.
In these figures, the hammer's flow system provides for the pressurized fluid in all possible modes and states, including the discharge of pressurized fluid to the peripheral area of the drill bit front end for flushing rock cuts, in the front chamber and in the rear. A solution designed under the present invention for transporting into the chamber and from the bottom of the hole is shown. The direction of the pressurized fluid is indicated through the arrows.

1 to 4, the reverse circulation DTH hammer is shown to include the following main components:

Cylindrical outer casing 1;

A rear sub 20 attached to the rear end of the outer casing 1 for connecting the hammer to the sove of the pressurized fluid;

A front chamber 240 slidably coaxially disposed inside the outer casing 1 and located at both ends of the piston 60 having outer sliding surface portions 63 and inner surface portions 64; A centrally-bored piston 60 capable of reciprocating due to a change in pressure of the pressurized fluid received inside the rear chamber 230;

The outer casing is slidably mounted on the front end of the hammer on the driver sub 110 mounted at the front end of the outer casing 1 and is disposed by the drill bit guide portion 150 disposed inside the outer casing 1. Drill bit aligned with (1) and restricted sliding movement by the drill bit retainer 210 and the drill bit supporting face 111 of the driver sub 110 90; And

A sample tube 130, disposed coaxially inside the outer casing 1, extending from the drill bit 90 to the rear sub 20.

According to the pressurized fluid flow system of the present invention, the center through piston has an outer sliding surface portion 63, a front inner sliding surface portion 64a at the inner surface portions 64 of the piston 60, a rear inner sliding. Having a surface portion 64b and a central groove portion 64c; And the sample tube 130 has a center control outer surface portion 131c for interacting with the front inner sliding surface portion 64a of the piston.

In addition, the cylinder 40 and the cylindrical control tube 170 are provided to be disposed coaxially between the outer casing 1 and the piston 60 and between the piston 60 and the sample tube 130, respectively. The sample tube then includes a recessed rear end outer surface portion 131b such that an annular passageway 175 is formed between the sample tube 130 and the control tube 170. A portion of the inner surface portion 5 of the outer casing 1, the drill bit guide portion 150 and the rear sub while the cylindrical control tube 170 is supported on the front inner guide surface portions 21 of the rear sub 20. 20 provides support for the cylindrical portion 40. The cylindrical control tube 170 has an inner surface portion 178, a front end control outer surface portion 171a and a rear end grooved outer surface portion 171b. Cylindrical portion 40 extends from rear sub 20 to drill bit guide 150, control tube 170 is coupled to rear sub 20 by engagement 174 and inner surface portions 178. And an outer surface portion 171 extending forward from the rear sub 20.

Accordingly, the rear chamber 230 of the hammer is delimited by the rear sub 20, the cylindrical portion 40, the control tube 170 and the rear thrust surface portion 62b of the piston 60. . The front chamber 240 of the hammer is then driven by the drill bit 90, the cylindrical portion 40, the drill bit guide portion 150, the sample tube 130 and the front thrust surface portion 62a of the piston 60. The range is determined. The volume of these chambers 230, 240 is variable depending on the position of the piston 60.

The pressurized fluid flow system of the present invention further comprises a discharge chamber 2, which discharges pressurized fluid from the front chamber 240 and the rear chamber 230 in front of the hammer when the hammer is in operation. And in permanent fluid communication with the bottom of the hole drilled by the hammer to release from and to the bottom of the hole. In the exemplary embodiment shown in the figures, the discharge chamber 2 has discharge passages 2b, 2c extending from each end of the central annular space 2a and the central annular space 2a in the middle. ), Wherein both the annular space 2a and the passages 2b, 2c are formed by grooves in the inner surface portions 5 of the outer casing 1 and by the cylindrical portion 40. It is internally scoped. It is to be understood that the discharge chamber 2 may have other configurations, such as formed by one annular groove in the inner surface portion 5 of the outer casing 1.

The front set 42 of pressurized fluid discharge pass ports and the rear set 41 of pressurized fluid discharge pass ports respectively channel pressurized fluid out of the front and rear chambers 240 and 230 and into the discharge chamber 2. Is provided to the cylindrical portion 40 to send along, so that the flow of pressurized fluid discharged from the front and rear chambers is controlled only by the overlap or relative position of the outer sliding surface portions of the piston with the inner surface portion of the cylindrical portion. .

The pressurized fluid flow system of the present invention also includes an inner chamber 68 for supplying pressurized fluid to the front chamber 240 and the rear chamber 230. In the embodiment shown in the figures, the inner chamber 68 is formed by a central groove 64c in the inner surface portions 64 of the piston 60, which is externally formed by the central groove 64c. The outer surface portions 131 of the sample tube 130 only (see FIG. 1) or with the outer surface portions 171 of the control tube 170, depending on the position of the piston during operation of the hammer. It is internally bounded by the outer surface portions 131 of the sample tube 130 (see FIG. 2).

According to a preferred embodiment of the present invention as shown in the figures, the control tube 170 has a set of inlet ports 177 at its rear end, the set of inlet ports for which pressurized fluid is applied to the control tube 170. Flowing from the rear sub 20 to the inner chamber 68 through an annular passage 175 formed between the inner surface portion 178 of the inner surface portion 178 and the grooved rear end outer surface portion 131b of the sample tube 130. Make it possible.

When the hammer is in the operating state, the inner chamber 68 is in permanent fluid communication with the source portion of the pressurized fluid and is filled with the pressurized fluid. As the piston 60 reciprocates, the front annular feed passage 67a is between the front inner sliding surface portion 64a of the piston 60 and the grooved front end outer surface portion 131a of the sample tube 130. And a rear annular supply passage 67b is formed between the rear inner sliding surface portion 64b of the piston 60 and the grooved rear end outer surface portion 171b of the control tube 170, respectively, to pressurize the fluid. To the front and rear chambers 240 and 230 of the hammer. Thus, the inflow of pressurized fluid into the front and rear chambers 240, 230 overlaps the front inner sliding surface portion 64a of the piston 60 with the central control outer surface portion 131c of the sample tube 130. And by the overlap of the rear inner sliding surface portion 64b of the piston 60 with the front end control outer surface portion 171a of the cylindrical control tube 170, respectively.

In addition, the outer casing 1 of the pressurized fluid flow system of the present invention has one or more end discharge ports 3 connected to respective longitudinal discharge channels 4 machined on the outer surface portion of the front end portion of the outer casing. ) At its front end portion, wherein both the end discharge port 3 and the longitudinal discharge channel 4 carry the flow of pressurized fluid contained within the discharge chamber 2 in the front and rear chambers 240, 230 of the hammer. ) And transfers out of the outer casing 1 and from there to the peripheral region of the front end of the drill bit 90. The end release port 3 and the longitudinal release channel 4 are covered with a sealing member, such as a shroud or cylindrical outer sealing sleeve 190.

State control of the front chamber 240

In the hammer cycle, when the impact surface 61 of the piston 60 is in contact with the impact surface 95 of the drill bit 90 and the drill bit 90 is at the rearmost point of its stroke, ie When the hammer is in the impact position (see FIG. 1), the front chamber 240 is between the front inner sliding surface portion 64a of the piston 60 and the grooved front end outer surface portion 131a of the sample tube 130. Fluidly with the internal chamber 68 through the front annular feed passage 67a formed at and through a set of flow enhancement passages 99 machined on the impact surface 95 of the drill bit 90. Communicating. In this way, the pressurized fluid can flow from the inner chamber 68 toward the front chamber 240 to begin the movement of the piston 60 back.

The inflow of pressurized fluid into the front chamber 240 reaches the point where the pressurized fluid supply edge 66a in front of the piston 60 reaches the pressurized fluid supply edge 133 in front of the sample tube 130. It will stop when the piston 60 moves from the front end toward the rear end of the stroke. As the piston 60 movement continues further from the front end toward the rear end of the stroke, the pressurized fluid discharge edge 65a in front of the piston 60 is forward of the pressurized fluid discharge pass ports of the cylinder 40. The point that matches the front limit of the set 42 will be reached. As the piston 60 movement continues further, the hammer's front chamber 240 is in fluid communication with the discharge chamber 2 through the front set 42 of pressurized fluid discharge passage ports of the cylinder 40. Will be (see FIG. 2). In this way, the pressurized fluid contained in the front chamber 240 will be released into the discharge chamber 2 and it is possible to flow freely out of the outer casing 1 from the discharge chamber 2. According to the exemplary embodiment shown in the figures, pressurized fluid from the discharge chamber 2 is pressurized fluid discharge passages 151, discharge grooves 152 and discharge of the drill bit guide 150. Through and through the ports 153 is discharged to the end discharge ports 3 of the outer casing 1. The pressurized fluid from the ports 3 is then guided through the longitudinal discharge channels 4 of the outer casing 1 to the peripheral region of the front end of the drill bit 90. These ports 3 and channels 4 are covered by a shroud or outer sealing sleeve 190.

State control of the rear chamber 230

In the hammer cycle, when the impact surface 61 of the piston 60 is in contact with the impact surface 95 of the drill bit 90 and the drill bit 90 is at the rearmost point of its stroke, ie When the hammer is in the impact position (see FIG. 1), the rear chamber 230 is in direct fluid communication with the discharge chamber 2 through the rear set 41 of pressurized fluid discharge pass ports of the cylindrical portion 40. have. In this way, the pressurized fluid contained in the rear chamber 230 is free to flow into the discharge chamber 2, and pressurized fluid discharge passages of the drill bit guide portion 150 from the discharge chamber 2. 151, through the discharge grooves 152 and the discharge ports 153 and through the end discharge ports 3 of the outer casing 1, it is possible to flow freely out of the outer casing 1. From the lead through the longitudinal discharge channels 4 of the outer casing 1 to the peripheral region of the front end of the drill bit 90. These ports 3 and channels 4 are covered by a shroud or outer sealing sleeve 190.

The outflow of pressurized fluid from the rear chamber 230 is such that the pressurized fluid discharge edge 65b at the rear of the piston 60 restricts the rear of the rear set 41 of the pressurized fluid discharge passage ports of the cylinder 40. The piston 60 will stop when it moves in the direction of the rear end of the stroke from the front end until it reaches the part. As the piston 60 motion continues further from the front end toward the rear end of the stroke, the pressurized fluid supply edge 66b at the rear of the piston 60 is followed by the pressurized fluid supply edge at the rear of the control tube 170. 172) will be reached. As the piston 60 movement continues further, the rear chamber 230 of the hammer has a rear inner sliding surface 64b of the piston 60 and a grooved rear end outer surface 171b of the control tube 170. It is in fluid communication with the internal chamber 68 of the piston 60 via a rear annular feed passage 67b formed therebetween (see FIG. 2). In this way, the rear chamber 230 will be filled with pressurized fluid coming from the inner chamber 68.

Flushing Mode Operation

In the flushing mode of the hammer shown by FIG. 3, ie when the impact of the hammer has stopped, the impact surface 61 of the piston 60 rests on the impact surface 95 of the drill bit 90, and The pressurized fluid enters the rear chamber 230, through the rear sub 20, through the set of pressurized fluid inlet ports 177 of the control tube 170, as follows: the inner surface of the control tube 170. Through the annular passage 175 formed between the portion 178 and the grooved rear end outer surface portion 131b of the sample tube 130 to the rear chamber 230; And directly to the peripheral region of the front end of the drill bit 90 through the path to the discharge chamber 2 through the rear set 41 of the pressurized fluid discharge passage ports of the cylindrical portion 40 from the rear chamber 230. do. The pressurized fluid from the discharge chamber 2 passes through the pressurized fluid discharge passages 151, the discharge grooves 152 and the discharge ports 153 of the drill bit guide 150 and of the outer casing 1. It is possible to flow freely out of the outer casing 1 via the end discharge ports 3, from here on through the longitudinal discharge channels 4 of the outer casing 1 of the front end of the drill bit 90. Guided to the surrounding area. These ports 3 and channels 4 are covered by a shroud or outer sealing sleeve 190.

Then, the pressurized fluid flowing from the internal chamber 68 of the piston 60 into the front chamber 240 is pressurized fluid discharge grooves 152 and discharge ports 153 of the drill bit guide 150. It is carried out of the outer casing 1 through and through the set of end release ports 3 of the outer casing 1.

1 ... outer casing 2 ... discharge chamber
20 ... rear sub 40 ... cylindrical part
60 ... piston 90 ... drill bit
130 ... sample tube 170 ... control tube
230, 240 ... rear and front chambers

Claims

A pressurized fluid flow system for a reverse circulating drill hammer,
Hammer is:
A cylindrical outer casing 1 having a front end and a rear end;
A rear sub 20 attached to the rear end of the outer casing 1 for connecting the hammer to the sove of the pressurized fluid;
A front chamber 240 slidably coaxially disposed inside the outer casing 1 and located at both ends of the piston 60 having outer sliding surface portions 63 and inner surface portions 64; A center through piston 60 capable of reciprocating due to a change in pressure of the pressurized fluid received inside the rear chamber 230;
A drill bit 90 slidably mounted to the front end of the hammer on a driver sub 110 mounted to the front end of the outer casing; And
Disposed coaxially inside the outer casing 1 and extending from the drill bit 90 to the rear sub 20 while passing through the center hole of the piston 60, the inner surface portions 136 and the outer surface; Comprises a sample tube 130 as major components, with parts 131,
Pressurized fluid flow systems are:
Disposed coaxially between the outer casing 1 and the piston 60, extending from the rear sub 20 to the drill bit guide portion 150, having an inner surface portion 43 and an outer surface portion 44. , Cylindrical portion 40;
Disposed coaxially between the piston 60 and the sample tube 130, extending forwardly from the rear sub 20 joined by the coupling 174, the inner surface portions 178 and the outer surface portions 171. A cylindrical control tube 170, with;
It is formed by one or more grooves in the inner surface of the outer casing 1 and is internally delimited by the cylindrical portion 40 and discharges pressurized fluid from the front and rear chambers 240, 230. A discharge chamber 2 in permanent fluid communication with the bottom of the hole for the purpose of; And
Formed in the central groove 64c made in the inner surface portions 64 of the piston 60, and according to the position of the piston during operation of the hammer only with the outer surface portions 131 of the sample tube 130 or the control tube ( Bounded by the outer surface portions 171 of 170 and in permanent fluid communication with the source portion of the pressurized fluid to supply the pressurized fluid to the front and rear chambers 240, 230. Which includes an internal chamber 68,
Cylindrical portion 40 is a pressurized fluid and a front set 42 of pressurized fluid discharge pass ports for directing pressurized fluid out of the front and rear chambers 240, 230 and into the discharge chamber 2, respectively. Has a rear set 41 of discharge pass ports;
The control tube 170 is pressurized connected to the annular passage 175 formed between the control tube 170 and the sample tube 130 to allow pressurized fluid to flow from the rear sub 20 to the inner chamber 68. Has a fluid inlet means 177 at the coupling portion 174;
The sample tube 130 is outside the grooved front end forming the front annular feed passage 67a and the inner surface portions 64 of the piston 60 to direct the flow of pressurized fluid along the channel into the front chamber 240. A surface portion 131a;
The control tube 170 is configured to direct the flow of pressurized fluid along the channel into the rear chamber 230 and the inner surface portions 64 of the piston 60 and the grooved rear end outer surface portion 171b of the control tube 170. Including a grooved rear end outer surface portion 171b for forming a rear annular feed passage 67b between
The flow of pressurized fluid discharged from the front and rear chambers 240, 230 is only at the overlap or relative position of the outer sliding surface portions 63 of the piston 60 with the inner surface portion 43 of the cylindrical portion 40. The inflow of the controlled, pressurized fluid into the front and rear chambers 240, 230 is characterized by a piston with the outer surface portions 171 of the cylindrical control tube 170 and the outer surface portions 131 of the sample tube 130. 60. A pressurized fluid flow system controlled by the overlap of the inner surface portions 64 of 60).

The method of claim 1,
The inner surface portions 64 of the piston 60 are divided into a front inner sliding surface portion 64a and a rear inner sliding surface portion 64b separated by a central groove portion 64c;
The sample tube 130 is located in front of the control tube 170 and the front inner sliding of the piston 60 in allowing or blocking the flow of pressurized fluid into the front chamber 240 during operation of the hammer. And a central control outer surface portion (131c) extending to the grooved front end outer surface portion (131a) to interact with the surface portion (64a).

The method of claim 2,
The sample tube 130 extends from the pressurized fluid inlet means 177 of the control tube 170 to the central control outer surface portion 131c with the inner surface portions 178 of the cylindrical control tube 170. And further comprising a grooved rear outer surface portion (131b) forming an annular passageway (175).

The method of claim 1,
The control tube 170 is a front end for interacting with the rear inner sliding surface 64b of the piston 60 in allowing or blocking the flow of pressurized fluid into the rear chamber 230 during operation of the hammer. Pressurized fluid flow system further comprising a control outer surface portion (171a).

The method according to claim 1 or 2,
A pressurized fluid flow system in which the set of pressurized fluid inlet means (177) of the control tube (170) connected with the annular passage (175) formed between the control tube (170) and the sample tube consists of a set of inlet ports.

The pressurized fluid flow system of claim 1; And
One or more end discharge ports 3 connected to respective longitudinal discharge channels 4 formed on the outer surface portion of the front end of the outer casing,
Both the end discharge port 3 and the longitudinal discharge channel 4 direct the flow of pressurized fluid from and along the sides of the front end of the outer casing 1 out of the outer casing 1 from the discharge chamber 2. Reverse circulating DTH hammer with the function of transporting to the peripheral region of the front end of the drill bit 90.

The method of claim 6,
End discharge ports 3 and longitudinal discharge channels 4 direct the pressurized fluid to the peripheral region of the front end of the drill bit and draw rock cuts toward the sample tube 130. Reverse circulating DTH hammer covered by a sealing member, such as a shroud or cylindrical outer sealing sleeve 190 to create a pressurized fluid flow across the front face.