CN107630664B - A kind of warm ice sheet drilling ice auger drill bit - Google Patents

Abstract

The invention discloses a kind of warm ice sheet drilling ice auger drill bits, include drill body, special-shaped cutting element and pad shoes, the bottom of wherein drill body offers several sinks, make to form a channel between the inner cavity of drill body and outer wall by the sink, several abnormal shape cutting elements and pad shoes are fixed on side by side on the bottom labial surface of drill body.The bottom surface of pad shoes is provided with the protrusion or pit of several micro/nano levels.Advantageous effect：Advantageously reduce the frictional heat of drill bit bottom.Therefore, ice auger drill bit proposed by the present invention can reduce cutting heat, be conducive to that drilling fluid is cooling and carry ice bits, can effectively prevent and avoid a large amount of adherency that ice considers to be worth doing, coalesce, can in ice sheet is warmed up in glacier safety, fast drilling.

Description

An ice drill bit for drilling into warm ice layers

technical field

The invention relates to an ice drill bit, in particular to an ice drill bit for drilling into warm ice layers.

Background technique

Currently, the polar ice caps account for about 10% of the global land area, and their natural environment is of great value to human beings. Polar ice caps and glaciers contain ancient ice layers that have accumulated in an orderly manner with snowflakes falling for millions of years. The dust particles, soluble chemicals and gases contained in ice are important for studying global climate change and predicting future climate and environmental changes. is of great significance. All countries in the world are competing to carry out polar deep ice core drilling projects in order to obtain high-quality ice cores with a long history. However, polar drilling practices have shown that there is a region of warm ice at the base of the ice sheet. Under the action of the base ground temperature and the pressure of the overlying ice layer, the temperature of the ice is relatively high and approaches or even reaches the pressure melting point of ice. When drilling with rotary cutting, the heat generated by the cutting of the drill bit can easily melt the ice chips or be in a melted state. These ice chips in a nearly melted state adhere and agglomerate, which is not only difficult to effectively discharge, but also easily adsorbed on the drill bit cutting tool or The local position of the drilling tool hinders the circulation of the drilling fluid and affects the drilling efficiency. These ice chips may even freeze again in some parts of the drilling tool, resulting in drill sticking accidents, which not only greatly increases the cost of polar drilling, but also is extremely complicated and difficult to deal with due to the constraints of the polar environment. Many deep ice core drilling projects, such as the Arctic Greenland ice sheet NorthGRIP project, Antarctic Dome C drilling project, etc., have to stop drilling because they cannot solve the above-mentioned technical problems of drilling in warm ice layers. Therefore, how to improve the drilling efficiency in warm ice layers and ensure safe and rapid drilling in warm ice layers has become an urgent technical problem to be solved in polar deep ice core drilling projects.

Contents of the invention

The object of the present invention is to provide an ice drill bit for drilling warm ice layers in order to improve the drilling efficiency of warm ice layers in the process of drilling ice cores in polar regions, ensure safe and fast drilling of warm ice layers.

The ice drill bit for drilling into warm ice layers provided by the present invention includes a drill body, a special-shaped cutting tool and a shoe pad, wherein the bottom of the drill body is provided with several water tanks, and a gap is formed between the inner cavity and the outer wall of the drill body through the water tanks. The channel, several special-shaped cutting tools and pad shoes are fixed side by side on the bottom lip surface of the drill body.

The bottom surface of the insole is provided with several micronano level protrusions or pits.

The special-shaped cutting tool is provided with two cutting edges. The rake faces of the two cutting edges correspond to the position of the water groove at the bottom of the drill body. The two cutting edges are arranged side by side or front and back or up and down. There is a through groove between them, and the through groove is cylindrical or rectangular. When the two cutting edges are arranged front and back, the outer diameter of the rear cutting edge is greater than the inner diameter of the front cutting edge; when the two cutting edges are arranged up and down, the outer diameter of the upper cutting edge larger than the inner diameter of the lower cutting edge.

The side wall of the drill body is also equipped with an ice core snap-off device, which is fixed on the side of the drill body by a pin shaft and an elastic retainer, and is used for snapping off and extracting the ice core.

Working principle of the present invention:

When the drill body rotates and cuts, the two cutting edges of the special-shaped cutting tool cut the ice layer respectively to generate ice chips, and the ice chips rise along the two cutting surfaces of the cutting tool respectively. Due to the design of double cutting edges, not only the single cutting The width of the blade effectively reduces the heat generated by rotary cutting, and the amount of ice chips generated by one revolution is greatly reduced. Drilling fluid descends from the annular gap between the drill body and the ice hole wall, and when flowing through the water tank at the bottom of the drill body, it cools the special-shaped cutting tool and carries ice chips back up through the inner cavity channel of the drill body. Due to the large flow space between the two cutting edges of the special-shaped cutting tool, the flow field near the cutting edges is effectively improved, which is more conducive to the cooling of the cutting edges by the drilling fluid and the carrying of ice chips. The pad shoe is directly installed on the bottom lip of the drill body through bolts to avoid direct contact with special-shaped cutting tools, and its structural size can be changed arbitrarily as needed to control the cutting depth of the cutting tool into the ice layer, thereby controlling the drilling speed and ice depth. Chip size. When the two cutting edges of the special-shaped cutting tool are not on the same level, the pad shoe mainly controls the cutting depth of the upper cutting edge. The micro-nano-level raised structure or pit structure designed on the bottom surface of the insole can effectively reduce the frictional resistance between it and the ice layer.

Beneficial effects of the present invention:

The double cutting edge design of the special-shaped cutting tool reduces the width of the cutting edge of a single cutting tool, which can greatly reduce the cutting heat generated by a single cutting edge, thereby reducing the temperature rise of the ice chips near it. At the same time, under the same conditions, the drill body rotates once, and the amount of ice debris generated by the cutting edge is greatly reduced, avoiding a large amount of ice debris accumulating on the cutting surface, which is beneficial to the drilling fluid ice debris carrying effect. In addition, the special-shaped cutting tool with double cutting edges and double cutting front and rear stepped or up and down stepped arrangement provides more space for drilling fluid circulation and is conducive to the cooling of cutting edges and ice chips by drilling fluid. When the double cutting edges of the special-shaped cutting tool are arranged side by side, there is a rectangular or other shaped channel in the middle, and the drilling fluid can circulate in the channel, which improves the cooling effect of the cutting edges. The design of the water groove on the drill body can reduce the circulation resistance of the drilling fluid, which is more conducive to the flow of the drilling fluid near the special-shaped cutting tool, so it is beneficial to cooling the cutting tool and carrying ice chips. The pad shoe is directly fixed on the bottom lip of the drill body by bolts, and does not contact the cutting tool. It is not only simple in structure and easy to replace, but also the heat of friction between it and the bottom ice layer is not directly transmitted to the cutting tool. The micro-nano-level protrusions or pits on the bottom surface form a non-smooth surface, which can reduce the friction between the pad shoe and the ice layer, and is beneficial to reduce the frictional heat at the bottom of the drill bit. Therefore, the ice drill bit proposed by the present invention can reduce cutting heat, facilitate the cooling of drilling fluid and carry ice chips, effectively prevent and avoid a large amount of adhesion and coalescence of ice chips, and can safely and quickly drill in warm ice layers of glaciers .

Description of drawings

Fig. 1 is a schematic diagram of the overall structure of the drill bit of the present invention.

Fig. 2 is a schematic diagram of the parallel arrangement of two cutting edges of the special-shaped cutting tool according to the present invention.

Fig. 3 is a schematic diagram of the front and rear arrangement of the two cutting edges of the special-shaped cutting tool according to the present invention.

Fig. 4 is a schematic diagram of the vertical arrangement of two cutting edges of the special-shaped cutting tool according to the present invention.

Fig. 5 is a schematic diagram of the structure of the insole according to the present invention.

1. Drill bit body 2. Special-shaped cutting tool 3. Pad shoe 4. Water tank 5. Ice core breaker 6. Pin shaft 7. Elastic retainer 8. Protrusion 9. Dimple 10. Through groove 11. Rear cutting edge 12. Front cutting edge 13, upper cutting edge 14, lower cutting edge.

Detailed ways

Please refer to Figure 1 to Figure 5:

The ice drill bit for drilling into warm ice layers provided by the present invention includes a drill body 1, a special-shaped cutting tool 2 and a shoe pad 3, wherein the bottom of the drill body 1 is provided with several water tanks 4, through which the water tank 4 makes the inside of the drill body 1 A channel is formed between the cavity and the outer wall, and several special-shaped cutting tools 2 and pad shoes 3 are fixed side by side on the bottom lip surface of the drill body 1 .

The side wall of the drill body 1 is also equipped with an ice core snap-off device 5, which is fixed on the side of the drill bit body 1 by a pin shaft 6 and an elastic retainer 7 for snapping off and extracting the ice core.

The bottom surface of the insole 3 is provided with several micronanoscale protrusions 8 or pits 9 .

The special-shaped cutting tool 2 is provided with two cutting edges, the rake faces of the two cutting edges correspond to the position of the water tank 4 at the bottom of the drill body 1, and the two cutting edges are arranged side by side or front and rear or up and down. The specific examples are as follows:

Embodiment one:

When the two cutting edges of the special-shaped cutting tool 2 are arranged side by side, a through groove 10 is arranged between the two cutting edges, and the through groove 10 is cylindrical or rectangular.

Embodiment two:

When the two cutting edges of the special-shaped cutting tool 2 are arranged front and back, the outer diameter of the rear cutting edge 11 is greater than the inner diameter of the front cutting edge 12 .

Embodiment three:

When the two cutting edges of the special-shaped cutting tool 2 are arranged up and down, the outer diameter of the upper cutting edge 13 is greater than the inner diameter of the lower cutting edge 14 .

Working principle of the present invention:

When the drill body 1 rotates and cuts, the two cutting edges of the special-shaped cutter 2 cut the ice layer respectively to generate ice chips, and the ice chips rise along the two cutting surfaces of the special-shaped cutter 2 respectively. Due to the design of the double cutting edges, it not only reduces The width of a single cutting edge is reduced to effectively reduce the heat generated by rotary cutting, and the amount of ice chips generated by one revolution is greatly reduced. Drilling fluid descends from the annular gap between the drill body 1 and the ice hole wall, and when it flows through the water tank 4 at the bottom of the drill body 1, it cools the special-shaped cutting tool 2 and carries ice chips back through the inner cavity channel of the drill body 1. Since there is a large flow space between the two cutting edges of the special-shaped cutting tool 2, the flow field near the cutting edges is effectively improved, which is more conducive to the cooling of the cutting edges by the drilling fluid and the carrying of ice chips. The pad shoe 3 is directly installed on the bottom lip surface of the drill body 1 through bolts to avoid direct contact with the special-shaped cutting tool 2, and its structural size can be changed arbitrarily according to needs, and is used to control the depth of the special-shaped cutting tool 2 cutting into the ice layer, thereby Control penetration rate and chip size. When the two cutting edges of the special-shaped cutting tool 2 are not on the same level, the pad shoe mainly controls the cutting depth of the upper cutting edge 13 . The micro-nano scale protrusion 8 structure or pit 9 structure designed on the bottom surface of the insole 3 can effectively reduce the frictional resistance between it and the ice layer.

Claims (1)

1. a kind of warm ice sheet drilling ice auger drill bit, include drill body, special-shaped cutting element and pad shoes, wherein drill body Bottom offers several sinks, makes to form a channel between the inner cavity of drill body and outer wall by the sink, several abnormal shapes are cut It cuts tool and pad shoes is fixed on side by side on the bottom labial surface of drill body, it is characterised in that：There are two the special-shaped cutting element settings The rake face of cutting edge, two cutting edges is corresponding to the position of drill body bottom sink, two cutting edges it is arranged side by side or front and back or It is setting up and down, when two cutting edges are set up in parallel, it is provided with straight slot between two cutting edges, straight slot is cylindrical or rectangle, two Before and after a cutting edge when setting, the outer diameter of rear cutting edge is more than the internal diameter of preceding cutting edge；When two cutting edges are setting up and down, above cut The outer diameter for cutting sword is more than the internal diameter of lower cutting edge.