Vacuum screw head

Abstract

The utility model discloses a vacuum screw head, relates to the field of drilling of soil layers or rocks, and solves the problem that when a single-pipe drilling tool is pulled out of a drill to extract a rock core, the suction effect in a drill hole reduces the rock core extraction rate. According to the technical scheme, the vacuum screw head comprises a connecting base and a sliding sleeve, the connecting base comprises a connecting shaft provided with a pipe cavity and a base fixed to one end of the connecting shaft, the other end of the connecting shaft is a connector used for being directly or indirectly connected with a drill rod, the connecting shaft is arranged in an inner hole of the sliding sleeve in a penetrating mode, and the sliding sleeve can slide along the connecting shaft. The outer side of the sliding sleeve is provided with an external thread which is used for being directly or indirectly connected with a single-pipe drilling tool. The connecting shaft is further provided with a first through hole and a second through hole, the first through hole and the second through hole are both communicated with a pipe cavity of the connecting shaft, the position of the sliding sleeve on the connecting shaft is automatically controlled through friction force between the sliding sleeve and the hole wall of the drill hole, opening and closing of the first through hole and the second through hole are correspondingly changed, and a flushing fluid conveying channel is correspondingly changed. The utility model can improve the core recovery rate.

Description

Technical Field

[0001] The utility model relates to the field of soil layer or rock drilling, in particular to a vacuum screw head used for connecting a single-tube drilling tool and a drill rod. Background Art

[0002] The drilling field of hydropower engineering is mainly divided into overburden drilling and bedrock drilling according to the formation conditions. Hydropower engineering exploration has high requirements for the core recovery rate of the borehole, with the core recovery rate of the overburden section reaching at least 85% and the core recovery rate of the bedrock section reaching at least 90%. The drilling techniques generally used in hydropower engineering are diamond drilling and rope coring drilling, among which the drilling tools of diamond drilling are mainly single-tube drilling tools and double-tube drilling tools.

[0003] Single-tube drill bits are used to collect cores and also need to be used as a transmission channel for flushing fluid. Core collection and flushing fluid flow in the same channel, so the flushing fluid will have a certain flushing effect on the core when it is sent into the borehole. At the same time, when the single-tube drill bit is pulled out of the drill hole to extract the core, it will be flushed by the flushing fluid and the suction in the borehole. The core is pulled downward and the core is easy to fall off in the core tube, which reduces the core recovery rate. This is also the main reason for the low core recovery rate of single-tube drill bits. Especially when drilling and coring loose formations, the core recovery rate is seriously affected, making it impossible for geologists to conduct formation identification. Due to the above reasons, the coring method using single-tube drill bits is generally suitable for intact, dense and less fractured formations, as well as formations with low requirements for coring quality. Single-tube drills have the advantages of simple structure, low cost, convenient operation and high drilling efficiency. How to effectively solve the influence of suction in the borehole on the core when the single-tube drill bit is pulled out of the drill hole to extract the core is the key to improving the core recovery rate of single-tube drill bits. Utility Model Content

[0004] The utility model provides a vacuum screw head, which solves the problem that the suction effect in the borehole reduces the core collection rate when the single-tube drilling tool is used to extract the core.

[0005] The technical scheme adopted by the utility model is: a vacuum screw head, comprising a connecting seat and a sliding sleeve, the connecting seat comprising a connecting shaft with a lumen arranged along the axial direction, and a base fixed to one end of the connecting shaft, the other end of the connecting shaft is a joint, the outer contour of the connecting shaft on its cross section is non-circular, the sliding sleeve is provided with an inner hole adapted to the connecting shaft, the connecting shaft is penetrated through the inner hole of the sliding sleeve, the sliding sleeve has two extreme positions when sliding along the connecting shaft, the first extreme position is that the sliding sleeve is located at the joint of the connecting shaft, and the second extreme position is that the sliding sleeve abuts against the base; an external thread is arranged on the outer side of the sliding sleeve, and the projection of the base on a plane perpendicular to the connecting shaft is located within the range of the projection of the outer contour of the sliding sleeve on a plane perpendicular to the connecting shaft; the connecting shaft is also provided with at least one first through hole and at least one second through hole, the first through hole and the second through hole are both connected to the lumen of the connecting shaft, and when the sliding sleeve is located at the first extreme position, the first through hole is located in the inner hole of the sliding sleeve, and the second through hole is located outside the inner hole of the sliding sleeve, and when the sliding sleeve is located at the second extreme position, the first through hole is located outside the inner hole of the sliding sleeve, and the second through hole is located in the inner hole of the sliding sleeve.

[0006] In order to facilitate the connection of the vacuum screw head to the drill rod, the vacuum screw head further includes an adapter, which is a straight tubular structure, and joints are respectively provided at both ends of the adapter, and one joint of the adapter is adapted and connected to the joint of the connecting shaft. For example, internal threads are respectively provided at both ends of the adapter, and an end of the connecting shaft away from the base is provided with an adapted external thread.

[0007] In order to make both ends of the adapter universal, further, the internal threads at both ends of the adapter are the same.

[0008] In order for the adapter to limit the sliding stroke of the sleeve, further: the outer contour of the adapter exceeds the outer contour of the connecting shaft.

[0009] In order to better transmit torque between the connecting shaft and the sliding sleeve, specifically: the outer contour of the connecting shaft is rectangular in its cross section, and the lumen of the connecting shaft is cylindrical.

[0010] The external thread on the outer side of the sleeve is used to connect the single-tube drilling tool. In order to ensure that the single-tube drilling tool can be firmly connected to the sleeve, further: a section of the sleeve away from the joint of the connecting shaft is a reduced diameter section, and the external thread of the sleeve is arranged in the reduced diameter section.

[0011] In order to prevent the first through hole and the second through hole from being cut off by the sliding sleeve at the same time, further: the minimum distance between the first through hole and the second through hole is smaller than the dimension of the sliding sleeve along the sliding direction.

[0012] In order to facilitate the flushing liquid to flow out smoothly from the tube cavity of the connecting shaft through the first through hole or the second through hole, further: four circular through holes are evenly arranged at the positions of 1 / 4 and 3 / 4 of the length of the connecting shaft.

[0013] The utility model has the following beneficial effects: the joint of the connecting shaft is used to directly or indirectly connect the drill rod, and the external thread on the outer side of the sliding sleeve is used to directly or indirectly connect the single-tube drilling tool. The friction between the outer side of the sliding sleeve and the wall of the borehole is used to automatically control the sliding sleeve to the first limit position and the second limit position, and change the flushing liquid delivery channel accordingly. When the single-tube drill tool is drilling downward, the downward force of the drill rod will cause the sleeve to be located at the first extreme position. At this time, the first through hole is cut off by the sleeve, and the second through hole is unobstructed. The flushing fluid can flow out from the tube cavity of the connecting shaft through the second through hole and enter the single-tube drill tool, and the sleeve does not affect the flushing fluid from entering the space below the sleeve; when the single-tube drill tool is lifted upward, the upward force of the drill rod will cause the sleeve to be located at the second extreme position. At this time, the second through hole is cut off by the sleeve, and the first through hole is unobstructed. The sleeve and the hole wall of the borehole are closed, and the sleeve blocks the flushing fluid from entering the space below the sleeve. The entire area between the sleeve and the bottom of the hole becomes a negative pressure area, which prevents the flushing fluid in the single-tube drill tool from scouring the core. More importantly, it can prevent the core from falling off due to the suction effect, thereby improving the core recovery rate of the single-tube drill tool. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The utility model is a schematic structural diagram of a vacuum screw head according to an embodiment of the present invention.

[0015] Reference numerals: connecting seat 1 , connecting shaft 11 , base 12 , first through hole 13 , second through hole 14 , sliding sleeve 2 , reduced diameter section 21 , adapter 3 . DETAILED DESCRIPTION

[0016] The utility model will be further described below in conjunction with the accompanying drawings.

[0017] like Figure 1 As shown, the utility model is a vacuum screw head, including a connecting seat 1 and a sliding sleeve 2. The connecting seat 1 includes a connecting shaft 11 and a base 12 fixed to one end of the connecting shaft 11. The connecting shaft 11 and the base 12 can be a whole, or one end of the connecting shaft 11 is fixedly connected to the base 12, for example, one end of the connecting shaft 11 is welded to the base 12. The connecting shaft 11 is provided with a lumen along the axial direction, and the lumen is columnar, generally cylindrical. The end of the connecting shaft 11 away from the base 12 is a joint, and the joint is used to directly or indirectly connect to a drill pipe. For example, a joint adapted to the drill pipe is provided at the end of the connecting shaft 11 away from the base 12; or refer to Figure 1 The vacuum screw head also includes an adapter 3, and the two ends of the adapter 3 are respectively provided with joints. One joint of the adapter 3 is adapted and connected to the joint of the connecting shaft 11, and the other joint of the adapter 3 is used to connect the drill rod. The adapter 3 is a straight tubular structure. After the two ends of the adapter 3 are connected to the connecting shaft 11 and the drill rod, the inner cavity of the drill rod, the tube cavity of the adapter 3 and the tube cavity of the connecting shaft 11 are connected. In order to facilitate connection, threads are respectively provided at the two ends of the adapter 3, for example, see Figure 1, the two ends of the adapter 3 are respectively provided with internal threads, and the end of the connecting shaft 11 away from the base 12 is provided with an adaptable external thread. In order to make the two ends of the adapter 3 universal, the internal threads at the two ends of the adapter 3 are the same.

[0018] The outer contour of the connecting shaft 11 on its cross section is non-circular. The outer contour of the connecting shaft 11 on its cross section is generally polygonal. For example, the outer contour of the connecting shaft 11 on its cross section is rectangular. At this time, the outer contour of the connecting shaft 11 is in the shape of a quadrangular prism. The sliding sleeve 2 is provided with an inner hole adapted to the connecting shaft 11. The connecting shaft 11 is inserted into the inner hole of the sliding sleeve 2. The sliding sleeve 2 can slide along the axial direction of the connecting shaft 11. Since the outer contour of the connecting shaft 11 on its cross section is non-circular, the sliding sleeve 2 cannot rotate around the connecting shaft 11. The sliding sleeve 2 has two extreme positions when sliding along the connecting shaft 11. The first extreme position is that the sliding sleeve 2 is located at the joint of the connecting shaft 11, and the second extreme position is that the sliding sleeve 2 is in contact with the base 12. The outer side of the connecting shaft 11 may be provided with a limiting structure corresponding to the first limit position, or after the joint of the connecting shaft 11 is connected to the drill rod, the drill rod naturally forms a limiting structure corresponding to the first limit position, or the joint of the connecting shaft 11 is connected to the adapter 3, the outer contour of the adapter 3 exceeds the outer contour of the connecting shaft 11, the adapter 3 limits the sliding stroke of the sliding sleeve 2, and the adapter 3 forms a limiting structure corresponding to the first limit position, such as Figure 1 The base 12 serves to seal one end of the connecting shaft 11 and also serves to limit the sliding travel of the sliding sleeve 2. The base 12 naturally becomes a limiting structure corresponding to the second extreme position.

[0019] The connecting shaft 11 is also provided with at least one first through hole 13 and at least one second through hole 14, and the first through hole 13 and the second through hole 14 are both connected to the lumen of the connecting shaft 11. The first through hole 13 and the second through hole 14 are both used for flushing liquid to flow out of the lumen of the connecting shaft 11. When the sliding sleeve 2 is located at the first extreme position, the first through hole 13 is located in the inner hole of the sliding sleeve 2, and the first through hole 13 is cut off by the sliding sleeve 2, and the second through hole 14 is located outside the inner hole of the sliding sleeve 2, and the second through hole 14 will not be cut off by the sliding sleeve 2; when the sliding sleeve 2 is located at the second extreme position, see Figure 1 , the first through hole 13 is located outside the inner hole of the sliding sleeve 2, and the first through hole 13 will not be cut off by the sliding sleeve 2, and the second through hole 14 is located inside the inner hole of the sliding sleeve 2, and the second through hole 14 is cut off by the sliding sleeve 2. In order to facilitate the flushing liquid to flow out smoothly from the lumen of the connecting shaft 11 through the first through hole 13 or the second through hole 14, both the first through hole 13 and the second through hole 14 are multiple. For example, the outer contour of the connecting shaft 11 is in the shape of a quadrangular prism, and the connecting shaft 11 is evenly provided with four circular through holes at 1 / 4 and 3 / 4 of its length, that is, a circular through hole is respectively provided on the four sides of the quadrangular prism at 1 / 4 and 3 / 4 of its length.

[0020] In order to avoid the phenomenon that the flushing liquid cannot flow out of the lumen of the connecting shaft 11 from the first through hole 13 or the second through hole 14 during the sliding of the sliding sleeve 2 along the connecting shaft 11, the minimum spacing between the first through hole 13 and the second through hole 14 is smaller than the dimension of the sliding sleeve 2 along the sliding direction, that is, no matter how the sliding sleeve 2 slides along the connecting shaft 11, the first through hole 13 and the second through hole 14 will not be cut off by the sliding sleeve 2 at the same time.

[0021] An external thread is arranged on the outer side of the sleeve 2, and the external thread is used to directly or indirectly connect the single-tube drill tool. In order to prevent the base 12 from affecting the connection between the single-tube drill tool and the sleeve 2, the projection of the base 12 on the plane perpendicular to the connecting shaft 11 is located within the range of the projection of the outer contour of the sleeve 2 on the plane perpendicular to the connecting shaft 11. For example, on the plane perpendicular to the connecting shaft 11, the projection of the outer contour of the base 12 and the projection of the outer contour of the sleeve 2 are both circular, and the diameter of the circle corresponding to the outer contour of the base 12 is smaller than the diameter of the circle corresponding to the outer contour of the sleeve 2. In order for the single-tube drill tool to be stably connected to the sleeve 2, a section of the sleeve 2 away from the joint of the connecting shaft 11 is a reduced diameter section 21, and the external thread of the sleeve 2 is arranged in the reduced diameter section 21, such as Figure 1 The single-tube drill is connected to the reduced diameter section 21, and the outer diameter of the single-tube drill is consistent with the outer diameter of a section of the sleeve 2 without external threads, which is beneficial to improve the sealing effect between the sleeve 2 and the wall of the borehole.

Claims

1. A vacuum screw head, characterized in that: The invention comprises a connecting seat (1) and a sliding sleeve (2), wherein the connecting seat (1) comprises a connecting shaft (11) having a tubular cavity arranged along the axial direction, and a base (12) fixed to one end of the connecting shaft (11), the other end of the connecting shaft (11) being a joint, the outer contour of the connecting shaft (11) on its cross section being non-circular, the sliding sleeve (2) being provided with an inner hole adapted to the connecting shaft (11), the connecting shaft (11) being passed through the inner hole of the sliding sleeve (2), the sliding sleeve (2) sliding along the connecting shaft (11) having two extreme positions, the first extreme position being the sliding sleeve (2) being located at the joint of the connecting shaft (11), and the second extreme position being the sliding sleeve (2) being in contact with the base (12); the outer side of the sliding sleeve (2) being provided with an external thread, the base (12) being provided with an external thread at the outer side of the connecting shaft (11), and the outer side of the sliding sleeve (2) being provided with an external thread at the outer side of the connecting shaft (11). The projection on a plane perpendicular to the connecting shaft (11) is located within the range of the projection of the outer contour of the sliding sleeve (2) on the plane perpendicular to the connecting shaft (11); the connecting shaft (11) is also provided with at least one first through hole (13) and at least one second through hole (14); both the first through hole (13) and the second through hole (14) are connected to the tubular cavity of the connecting shaft (11); and when the sliding sleeve (2) is located at a first extreme position, the first through hole (13) is located inside the inner hole of the sliding sleeve (2), and the second through hole (14) is located outside the inner hole of the sliding sleeve (2); and when the sliding sleeve (2) is located at a second extreme position, the first through hole (13) is located outside the inner hole of the sliding sleeve (2), and the second through hole (14) is located inside the inner hole of the sliding sleeve (2).

2. A vacuum screw head according to claim 1, characterized in that: It also includes an adapter (3), which is a straight tubular structure. Joints are respectively arranged at both ends of the adapter (3), and one joint of the adapter (3) is adapted to and connected with a joint of the connecting shaft (11).

3. A vacuum screw head according to claim 2, characterized in that: Internal threads are respectively arranged at both ends of the adapter (3), and a matching external thread is arranged at one end of the connecting shaft (11) away from the base (12).

4. A vacuum screw head according to claim 3, characterized in that: The internal threads at both ends of the adapter (3) are identical.

5. A vacuum screw head according to claim 2, characterized in that: The outer contour of the adapter (3) exceeds the outer contour of the connecting shaft (11).

6. A vacuum screw head according to any one of claims 1 to 5, characterized in that: The outer contour of the connecting shaft (11) is rectangular in its cross section, and the lumen of the connecting shaft (11) is cylindrical.

7. A vacuum screw head according to any one of claims 1 to 5, characterized in that: A section of the sliding sleeve (2) away from the joint of the connecting shaft (11) is a reduced diameter section (21), and the external thread of the sliding sleeve (2) is arranged on the reduced diameter section (21).

8. A vacuum screw head according to any one of claims 1 to 5, characterized in that: The minimum distance between the first through hole (13) and the second through hole (14) is smaller than the dimension of the sliding sleeve (2) along the sliding direction.

9. A vacuum screw head according to any one of claims 1 to 5, characterized in that: The connecting shaft (11) is evenly provided with four circular through holes at positions of 1 / 4 and 3 / 4 of its length.

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