A flushing-proof single-acting double-tube coring drill

Abstract

The application provides a flushing-resistant single-acting double-tube coring drill, which comprises an outer drill bit and an inner drill bit, the inner drill bit is detachably arranged in the inner part of the outer drill bit, a gap is left between the outer wall of the inner drill bit and the inner wall of the outer drill bit to form an annular flushing liquid channel, and a plurality of lateral holes which are communicated with the annular flushing liquid channel are arranged on the side wall of the drilling end of the outer drill bit. The device can change the flow direction of the flushing liquid by arranging the lateral holes, so that the flushing liquid does not directly flush the rock core, thereby effectively protecting the rock core and improving the drilling and coring efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of coring drilling tools, in particular to a single-acting double-tube coring drilling tool. BACKGROUND

[0002] The existing single-acting double-tube drilling tool has defects in the structure of the drilling tool, especially the layout of the inner and outer drill bits. The flushing liquid directly flushes the rock coal core through the gap between the inner and outer drill bits, causing damage to the rock coal core. At the same time, the inner and outer drill bits are not easy to adjust. If the gap between the two is too small, the contact between the two will affect the single-acting; if the gap is too large, it will seriously flush the rock coal core. In addition to the defects such as poor return flow of the flushing liquid, the drilling efficiency is seriously affected. SUMMARY

[0003] In order to solve the problems in the background art, the present application provides a single-acting double-tube coring drilling tool that can change the flow direction of the flushing liquid, so that the flushing liquid does not directly flush the rock core, thereby effectively protecting the rock core and improving the drilling and coring efficiency.

[0004] To achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0005] A single-acting double-tube coring drilling tool, comprising an outer drill bit and an inner drill bit, the inner drill bit being detachably arranged inside the outer drill bit, a gap being left between the outer wall of the inner drill bit and the inner wall of the outer drill bit to form an annular flushing liquid passage, a plurality of lateral holes being formed in the side wall of the drilling end of the outer drill bit, the lateral holes being communicated with the annular flushing liquid passage.

[0006] A positioning ring is arranged inside the drilling end of the outer drill bit, a plug-in groove communicated with the lateral holes being formed between the outer wall of the positioning ring and the inner wall of the outer drill bit, one end of the inner drill bit being provided with an inner drill bit plug-in ring, the inner drill bit plug-in ring being inserted into the plug-in groove to realize the detachable connection between the inner drill bit and the outer drill bit.

[0007] The lateral holes are obtained by recessing from the drilling end face of the outer drill bit to the other end.

[0008] The height of the positioning ring is greater than or equal to the depth of the lateral holes, and after the positioning ring is fixed in the inner cavity of the outer drill bit, the side wall of the positioning ring blocks one side of the lateral holes inside the outer drill bit.

[0009] The inner diameter of the inner drill bit plug-in ring is greater than the inner diameter of the inner cavity of the inner drill bit.

[0010] The outer wall of the inner drill bit plug-in ring is flush with the outer wall of the inner drill bit.

[0011] The outer drill bit and the inner drill bit are both provided with a threaded connection part at the end opposite to the drilling end, and the outer drill bit and the inner drill bit are connected with the outer drill rod and the inner drill rod respectively through the threaded connection part.

[0012] After the outer drill rod and the inner drill rod are connected with the outer drill bit and the inner drill bit respectively, the inner wall of the outer drill rod is flush with the inner wall of the outer drill bit, and the outer wall of the inner drill rod is flush with the outer wall of the inner drill bit.

[0013] A plurality of drill teeth for drilling are uniformly distributed on the drilling end of the outer drill bit along the circumferences of the end face, and the lateral holes are arranged between adjacent drill teeth.

[0014] The positioning ring is fixed in the inner cavity of the outer drill bit through the drill teeth.

[0015] The present application has the technical effects:

[0016] 1) By arranging the lateral holes on the side wall of the outer drill bit, the flow direction of the flushing liquid is changed, and the flushing liquid is prevented from directly washing the core, so that the core is effectively protected;

[0017] 2) The inner drill bit is sleeved on the positioning ring in the inner part of the outer drill bit in a plug-in manner, which is more easy to adjust, the concentricity of the inner and outer drill bits is more consistent, and the double-tube single-action is more easily formed.

[0018] 3) The lateral hole of the outer drill bit has a large opening, the reflux of the flushing liquid is more smooth, and the powder discharge effect is better. BRIEF DESCRIPTION OF DRAWINGS

[0019] The present application will be further described below in conjunction with the drawings, and the drawings of the present application only schematically illustrate and explain the present application and do not limit the scope of the present application.

[0020] Figure 1 It is a three-dimensional structure schematic view of the outer drill bit of the single-action double-tube core drilling tool.

[0021] Figure 2 It is Figure 1 It is an end face schematic view of the outer drill bit.

[0022] Figure 3 It is Figure 1 It is a cross-sectional structure schematic view of the outer drill bit.

[0023] Figure 4 It is a cross-sectional structure schematic view of the inner drill bit of the single-action double-tube core drilling tool.

[0024] Figure 5 It is a cross-sectional structure schematic view of the single-action double-tube core drilling tool after the inner drill bit and the outer drill bit are assembled together.

[0025] Among them:

[0026] 100-outer drill bit; 101-lateral hole; 102-outer drill bit threaded connection part;

[0027] 110-positioning ring; 120-plug-in slot; 130-drill tooth;

[0028] 200 - inner drill bit; 201 - inner drill bit spigot ring; 202 - inner drill bit threaded connection;

[0029] 210 - annular flushing channel;

[0030] 300 - inner drill rod; 400 - outer drill rod. DETAILED DESCRIPTION

[0031] The application will be described in detail below with specific examples, but the scope of protection of the application is not limited by the specific embodiments.

[0032] The application provides a flushing-preventing single-acting double-tube coring drill, which comprises an outer drill bit 100 and an inner drill bit 200.

[0033] The structure of the outer drill bit 100 is shown in Figures 1-3 , Figure 1 A three-dimensional structure diagram of the outer drill bit 100 is given, one end of the outer drill bit 100 is a drilling end, and the other end is a connecting end, the drilling end of the outer drill bit 100 is used for drilling downward, and the connecting end of the outer drill bit 100 has an outer drill bit threaded connection 102, and the outer drill bit 100 is connected with the outer drill rod 400 through the outer drill bit threaded connection 102. A plurality of drill teeth 130 for drilling are uniformly distributed on the end face circumference of the drilling end of the outer drill bit 100, and a lateral hole 101 is arranged between adjacent drill teeth 130, and the lateral hole 101 is obtained by recessing from the drilling end face of the outer drill bit 100 to the other end.

[0034] A positioning ring 110 is arranged in the cavity of the drilling end of the outer drill bit 100, and the outer diameter of the side wall of the positioning ring 110 is smaller than the inner diameter of the cavity of the outer drill bit 100, so that an insertion groove 120 for connecting the inner drill bit 200 is formed between the outer wall of the positioning ring 110 and the inner wall of the outer drill bit 100. Since the lateral hole 101 is arranged on the side wall of the outer drill bit 100, obviously, the insertion groove 120 communicates with the lateral hole 101. The height of the positioning ring 110 is greater than the depth of the lateral hole 101, so that the lateral hole 101 can be blocked towards the side of the inner part of the outer drill bit 100.

[0035] The structure of the inner drill bit is shown in Figure 4 , Figure 4A cross-sectional structural diagram of the internal drill bit 200 is provided. One end of the internal drill bit 200 is provided with an internal drill bit insertion ring 201, which is located on the end face of one end of the internal drill bit 200. The inner diameter of the internal drill bit insertion ring 201 is larger than the inner diameter of the cavity of the internal drill bit 200, and the outer wall of the internal drill bit insertion ring 201 is flush with the outer wall of the internal drill bit 200. The other end of the internal drill bit 200 is provided with an internal drill bit threaded connection part 202. The insertion ring 201 is used to insert into the insertion groove 120 in the external drill bit 100 to achieve connection with the external drill bit 100. The internal drill bit threaded connection part 202 is used to connect with the internal drill rod 300. After the internal drill rod 300 is connected to the internal drill bit threaded connection part 202, the outer wall of the internal drill rod 300 is flush with the outer wall of the internal drill bit 200.

[0036] Figure 5 A cross-sectional schematic diagram of a single-action double-tube coring drill bit, after the inner and outer drill bits are assembled together, is given, as follows: Figure 5 As shown, the outer diameter of the inner drill bit 200 is smaller than the inner diameter of the outer drill bit 100. In this way, after the insertion ring 201 is inserted into the insertion groove 120, an annular flushing fluid channel 210 is formed between the outer wall of the inner drill bit 200 and the inner wall of the outer drill bit 100. The annular flushing fluid channel 210 is connected to the insertion groove 120 and also to the side hole 101.

[0037] During drilling, the flushing fluid flows along the flushing fluid channel 210 to the bottom of the borehole. When it reaches the bottom of the outer drill bit 100, due to the blocking effect of the positioning ring 110, the flushing fluid flows out from the side of the outer drill bit 100 through the side hole 101 at the bottom of the outer drill bit 100, thereby changing the flow direction of the flushing fluid. This can prevent the flushing fluid from directly scouring the rock core, effectively protect the rock core, and improve the recovery rate of soft rock coal core.

[0038] The above description is merely a preferred embodiment of the present invention and is illustrative rather than restrictive. Those skilled in the art will understand that many changes, modifications, and even equivalents can be made within the spirit and scope defined by the claims, all of which will fall within the protection scope of the present invention.

Claims

1. A washover single-acting double tube coring drill assembly comprising an outer bit and an inner bit, characterized in that, The inner drill bit is detachably arranged in the inner part of the outer drill bit, and a gap is left between the outer wall of the inner drill bit and the inner wall of the outer drill bit to form an annular flushing liquid channel, a plurality of lateral holes are arranged on the side wall of the drilling end of the outer drill bit, and the lateral holes are communicated with the annular flushing liquid channel; A positioning ring is arranged in the inner part of the drilling end of the outer drill bit, an insertion slot communicated with the lateral holes is formed between the outer wall of the positioning ring and the inner wall of the outer drill bit, one end of the inner drill bit is provided with an inner drill bit insertion ring, the inner drill bit insertion ring is inserted into the insertion slot to realize the detachable connection between the inner drill bit and the outer drill bit; The lateral hole is obtained by recessing from the drilling end surface of the outer drill bit to the other end; The height of the positioning ring is greater than or equal to the depth of the lateral hole, and after the positioning ring is fixed in the inner cavity of the outer drill bit, the side wall of the positioning ring blocks the side of the lateral hole located in the inner part of the outer drill bit; A plurality of drill teeth for drilling are uniformly distributed on the drilling end of the outer drill bit along the circumference of the end surface, and the lateral hole is arranged between adjacent drill teeth.

2. A backwash-proof single-acting double-tube coring drill as claimed in claim 1, characterized in that The inner diameter of the inner drill bit insertion ring is greater than the inner diameter of the cavity of the inner drill bit.

3. A backwash-proof single-acting double-barrel coring drill as defined in claim 2, characterized in that The outer wall of the inner drill bit insertion ring is flush with the outer wall of the inner drill bit.

4. An anti-washout single acting double tube coring drill tool as claimed in any one of claims 1 to 3 wherein, Threaded connection parts are arranged on the ends opposite to the drilling ends of the outer drill bit and the inner drill bit, and the outer drill bit and the inner drill bit are respectively connected with an outer drill rod and an inner drill rod through the threaded connection parts.

5. A backflushing single acting double tube coring drill as claimed in claim 4 wherein, After the outer drill rod and the inner drill rod are respectively connected with the outer drill bit and the inner drill bit, the inner wall of the outer drill rod is flush with the inner wall of the outer drill bit, and the outer wall of the inner drill rod is flush with the outer wall of the inner drill bit.

6. A backwash-proof single-acting double tube coring drill as defined in claim 1, characterized in that, The positioning ring is fixed in the inner cavity of the outer drill bit through the drill teeth.

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