A core bit for quickly obtaining cores in geological exploration

Abstract

The present invention belongs to the technical field of geological exploration, and discloses a core bit for quickly obtaining core in geological exploration. In order to solve the problem that the cutting teeth of the existing core bit always remain at an angle, resulting in low drilling efficiency. The present invention includes a joint and a bit body connected to each other. The joint is used to connect with the drill pipe. The bit body includes a matrix and a plurality of cutter wings uniformly arranged on the crown of the matrix. A number of cutting teeth are installed on the cutter wings. A core channel is formed in the middle of the bit body. The angular position of the cutter wings on the matrix is adjustable. The present invention can adjust the angle of the cutter wings according to the geological conditions to change the cutting area of the cutting teeth on the cutter wings, so as to drill for different geological structures, achieve the purpose of improving the drilling efficiency, and then quickly obtain the core.

Description

Technical Field

[0001] The present invention belongs to the technical field of geological exploration, and particularly relates to a core bit for quickly obtaining cores in geological exploration. Background Art

[0002] A core is a rock sample drilled out by lowering a core-taking tool into a well according to the stratigraphic horizons and designed depths obtained from exploration during geological exploration. The core is the most intuitive and practical data for understanding the underground oil reservoir and the characteristics of the contained fluids.

[0003] Currently, for obtaining cores, core bits are basically used for drilling. There are also many technical documents on core bits in the prior art. For example, the patent with the application number 201420762280.5 discloses a six-wing composite-set core bit for shale gas coring. Six wings are evenly arranged on the bit crown at the upper section of the bit body. The wing thickness is equal. The main cutting teeth arranged on the wings are mixedly arranged in the way that TSP teeth are in the front and PDC cutting teeth are in the back. The angle a between the flank face and the rake face on the wing is 28° - 32°.

[0004] Another example is the patent with the application number 201420162468, which discloses an under-size coring bit, including a bit body and a sub. The bit body is installed on the sub. The bit body is composed of wings and a gauge. Cutting teeth are brazed on the wings. The cutting teeth located on the side of the bit are side cutting teeth. The distance L1 from the outer surface of the gauge to the center of the bit is the gauge outer diameter. The distance L2 from the outer surface of the side cutting teeth to the center of the bit is the side cutting tooth outer diameter. The gauge outer diameter L1 is smaller than the side cutting tooth outer diameter L2, forming an outer diameter difference L3.

[0005] Another example is the patent with the application number 2019102415276, which discloses a PDC core bit while drilling, including a bit body and the space inside the bit body. Plastic core teeth are arranged in the middle of the bit body. A core-taking channel and a jet channel are arranged in the internal space. Micro cores are discharged through the core discharge holes at one end of the core-taking channel. The jet flow channel communicates with the internal flow channel of the bit and the core-taking channel. A jet nozzle is arranged at the jet outlet of the jet flow channel for spraying high-speed drilling fluid, so as to generate a suction effect in the core-taking channel. The jet nozzle is arranged side by side with the core-breaking teeth and the core holes. The core-taking channel starts from the core holes and extends to the core discharge holes at the root of the gauge end of the bit. The end of the core-taking channel is the core discharge hole, which is arranged on the chamfer surface at the end of the wing, that is, behind the cutting teeth.

[0006] For another example, the patent with the application number 202021903704.7 discloses a core bit for accelerating coring in plastic formations, including a bit body. Multiple cutter wings distributed circumferentially are provided at both ends of the bit body. Crown surface cutting teeth are provided in the top area of the cutter wings, and gauge cutting teeth are provided on both the inner and outer sides of the cutter wings. A core-taking joint is provided at the rear end of the bit body. The crown surface cutting teeth are concave cutting teeth with a concave end surface at the cutting end, and the gauge cutting teeth are flat cutting teeth with a flat end surface at the cutting end.

[0007] As for the existing core bit described above, since the entire cutting teeth are fixedly arranged, the cutting angle of the entire cutting teeth always remains in one state. However, during the actual drilling process of the core bit, along with the change of the formation structure, especially when the cutting teeth still remain in one state in soft formations, the drilling efficiency will be low. Summary of the Invention

[0008] The present invention aims to solve the problem that the cutting teeth of the existing core bit always remain at one angle, resulting in low drilling efficiency. A core bit for quickly obtaining rock cores in geological exploration is provided, which can change the angle of the cutting teeth according to different terrains. Especially when dealing with soft formations, by changing the angle of the cutting teeth, the cutting angle in soft formations can be increased, thereby achieving the purpose of improving the overall drilling efficiency.

[0009] To solve the technical problems, the technical solution adopted by the present invention is as follows:

[0010] A core bit for quickly obtaining rock cores in geological exploration, including a joint and a bit body connected to each other. The joint is used to connect with the drill pipe. The bit body includes a matrix and multiple cutter wings evenly arranged on the crown of the matrix. A number of cutting teeth are installed on the cutter wings. A core channel is formed in the middle of the bit body. The characteristic is that the angular position of the cutter wings on the matrix is adjustable.

[0011] In some embodiments, a support seat is provided on the matrix. The cutter wing is installed on the support seat through a spindle. An adjustment mechanism for driving the cutter wing to rotate on the support seat is installed on the cutter wing. The adjustment mechanism includes a cavity opened along the length direction of the matrix. A plunger that is hermetically sealed with the inner wall of the cavity and can slide in the cavity is arranged in the cavity. One end of the plunger passes through the cavity and is connected to the cutter wing. A first channel and a second channel are also provided on the matrix. The first channel and the second channel are respectively communicated with the cavity on both sides of the plunger. The first channel and the second channel are communicated with an external hydraulic system through pipelines; the center of gravity position of the cutter wing is closer to the joint than the rotation axis of the cutter wing; a torsion spring for providing a pre-tightening force in the direction of the joint to the cutter wing is sleeved on the rotation axis.

[0012] In some embodiments, the first channel and the second channel are respectively provided with cocks. An installation cavity communicating with the first channel and the second channel is arranged on the matrix. One end of the cock passes through the installation cavity and is adapted to the first channel or the second channel. The other end of the cock is adapted to a cooling channel arranged in the matrix and used for inputting drilling fluid. A spring sleeved around the periphery of the cock is arranged in the installation cavity. When there is no drilling fluid in the cooling channel, the spring makes one end of the cock located in the cooling channel, and the other end of the cock flush with the inner wall of the first channel and / or the second channel. When drilling fluid is input into the cooling channel, one end of the cock extends into the first channel and / or the second channel, and the other end of the cock is flush with the inner wall of the cooling channel.

[0013] In some embodiments, an impact surface is arranged at one end of the cock close to the cooling channel. When drilling fluid enters the cooling channel, the drilling fluid impacts the impact surface of the cock, so that the cock overcomes the resistance of the spring and extends into the first channel and / or the second channel.

[0014] In some embodiments, sealing rings for sealing the installation cavity are arranged at both ends of the cock.

[0015] In some embodiments, two jet channels communicating with the cooling channel are formed on the matrix corresponding to each blade. The two jet channels spray out along both sides of the rotation direction of the blade respectively.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] During the use of the core drill bit for quickly obtaining core in geological exploration of the present invention, when encountering a soft formation, hydraulic oil is injected into the cavity through the first channel, and then the plunger is pushed to move towards the blade. Under the action of the plunger, the blade rotates along the rotating shaft on the matrix (that is, when the plunger pushes the blade outwards), so as to adjust the angle of the whole blade, so that more cutting surfaces of the cutting teeth on the blade are used for cutting, thereby improving the cutting efficiency of the cutting teeth on the blade and further improving the drilling speed (mainly for when the geology becomes soft); when the blade does not need to rotate, the external hydraulic system controls the plunger to move in the reverse direction (that is, the plunger moves along the direction towards the joint), and together with the reset action of the torsion spring, the blade is driven to rotate along the direction towards the joint, so that the cutting teeth on the blade are in the original state (that is, the cutting surface area for cutting on the cutting teeth is the smallest) to cut hard formations (such as rocks). In summary, the core drill bit for quickly obtaining core in geological exploration of the present invention can adjust the angle of the blade according to the geological conditions to change the cutting area of the cutting teeth on the blade, so as to drill for different geological structures, achieve the purpose of improving the drilling efficiency, and further quickly obtain the core.

[0018] During the use of the present invention, due to the rotation of the cutter blade, the cutting teeth are driven to rotate as well, so that different positions on the cutting teeth perform cutting. While improving the cutting efficiency, it can also delay the wear of the cutting teeth, increase the service life of the cutting teeth, reduce the frequency of replacing the coring bit, and thus achieve the purpose of improving the drilling efficiency.

[0019] In the present invention, a plug is arranged in the first channel and the second channel, and the movement of the plug is affected by the working state of the drilling fluid. When the drilling fluid is introduced into the cooling channel, the drilling fluid pushes the plug to move towards the first channel and the second channel, thereby closing and locking the first channel and the second channel, and further fixing the position of the plunger, preventing the cutter blade and the cutting teeth on the cutter blade from rotating along the rotating shaft during the cutting process, and ensuring the locking of the position of the cutting teeth after adjustment. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic structural diagram of an embodiment of the present invention;

[0021] Figure 2 is a schematic structural diagram of a partial cross-sectional view of the present invention;

[0022] Figure 3 is Figure 2 a schematic diagram of a partial enlarged view at A in

[0023] Figure 4 is Figure 2 a schematic diagram of a partial enlarged view at B in, in which the plug extends into the cooling channel, and there is no drilling fluid introduced into the cooling channel;

[0024] Figure 5 is a schematic structural diagram of the plug of the present invention extending into the first channel and / or the second channel, in which the arrow in the diagram represents the flow direction of the drilling fluid;

[0025] Figure 6 is Figure 2 a schematic diagram of a partial enlarged view at C in

[0026] Reference numerals in the figures: 1, sub - adapter; 2, bit body; 3, matrix; 4, cutter blade; 41, movable gap; 5, cutting teeth; 6, rotating shaft; 7, gauge protection teeth; 8, chip groove; 9, support seat; 10, cavity; 11, plunger; 12, first channel; 13, second channel; 14, cooling channel; 41, first jet channel; 42, second jet channel; 15, plug; 16, plug head; 17, coring channel; 18, sealing cover; 19, spring; 20, mounting plate; 21, mounting cavity. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] The present invention will be further described below in conjunction with embodiments. The described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

[0028] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention; the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance; in addition, unless otherwise clearly defined and limited, the terms "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection; it can be directly connected, or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in combination with specific situations.

[0029] Combined with the attached Figure 1 to the attached Figure 6 The core bit for quickly obtaining core samples in geological exploration of the present invention includes a joint 1 and a bit body 2 that are connected to each other. The joint 2 is used to connect to the drill pipe. The bit body 2 includes a matrix 3 and a plurality of cutter wings 4 uniformly arranged on the crown of the matrix 3. A number of cutting teeth 5 are installed on the cutter wings 4. A core channel 17 is formed in the middle of the bit body 2. The angular position of the cutter wings 4 on the matrix 3 is adjustable. Among them, the cutting teeth are PDC cutting teeth, and the cutting teeth are inlaid on the cutter wings; the matrix 3 has two major categories: cemented carbide matrix and steel body, which can be understood and comprehended by those skilled in the art and will not be elaborated here.

[0030] Among them, the cutter wings 4 are arranged at intervals on the crown of the matrix 3. Chip grooves 8 are provided on the matrix 3 between adjacent cutter wings 4, and the chip grooves 8 are used to discharge the debris during drilling.

[0031] Preferably, multiple rows of gauge protection teeth 7 are provided on the bit body 2 above the cutter wings 4, and chip grooves 8 are also provided between two adjacent rows of gauge protection teeth 7 to facilitate the discharge of debris.

[0032] Combined with the attached Figure 1 and the attached Figure 2, in some embodiments, a support base 9 is provided on the matrix body 3, and the cutter blade 4 is mounted on the support base 9 via a spindle 6. Among them, an activity gap 41 is formed between the matrix body 3 and the cutter blade 4 to facilitate the movement of the cutter blade 4. An adjustment mechanism for driving the cutter blade 4 to rotate on the support base 9 is mounted on the cutter blade 4. The adjustment mechanism includes a cavity 10 opened along the length direction of the matrix body 3. A plunger 11 that is hermetically sealed with the inner wall of the cavity 10 and can slide in the cavity 10 is arranged in the cavity 10. One end of the plunger 11 passes out of the cavity 10 and is connected to the cutter blade 4. A first channel 12 and a second channel 13 are further provided on the matrix body 3. The first channel 12 and the second channel 13 are respectively communicated with the cavity 10 on both sides of the plunger 11. The first channel 12 and the second channel 13 are communicated with an external hydraulic system via pipelines; the center of gravity position of the cutter blade 4 is closer to the joint 1 than the rotation axis 6 of the cutter blade 4; a torsion spring (the structure of the torsion spring, as well as the function and function of providing the pre-tightening force belong to the prior art, and those skilled in the art can understand and comprehend, so it is not shown in the drawings) for providing a pre-tightening force in the direction of the joint 1 to the cutter blade is sleeved on the rotation axis 6. Through the design of the center of gravity of the cutter blade 4 in the present invention, the center of gravity of the cutter blade 4 is closer to the joint 1 than the rotation axis 6. On the one hand, through the pre-tightening force of the torsion spring and relying on the center of gravity of the cutter blade 4, the cutter blade 4 is maintained in the initial state without the action of the plunger 11 (that is, in this state, the cutter blade 4 does not rotate, and at this time, the contact area between the cutting teeth 5 and the rock and soil body is the smallest for cutting hard rock masses); on the other hand, when the angle of the cutter blade 4 rotates under the action of the plunger 11, the pre-tightening force of the torsion spring and the setting relying on the center of gravity of the cutter blade 4 can improve the stability of the state maintenance of the cutter blade 4 and prevent the cutting teeth from rotating during the cutting process, so that the cutting teeth can maintain the cutting of the formation according to the adjusted angle.

[0033] In the present invention, the matrix body 3 can adopt a modular structure. First, the cavity 10, the first channel 12, the second channel 13, the cooling channel 14 (the first jet channel 141 and the second jet channel 142), and the installation cavity 21 are opened, and then welding and assembly are carried out. In some embodiments, when opening the cavity 10, the first channel 12, the second channel 13, the cooling channel 14 (the first jet channel 141 and the second jet channel 142), and the installation cavity 21, through holes can be opened on the matrix body according to the layout structure, and then some of the through holes are closed and welded by plugs 16 to form the corresponding channels and / or cavities.

[0034] Combined with the attached Figure 2 and the attached Figure 3, the plunger 11 is in the shape of a stepped shaft with one end larger and the other end smaller. The large-diameter end of the plunger 11 is used to fit with the inner wall of the cavity 10, and the small-diameter end of the plunger 11 is used to pass through the cavity 10 and connect with the cutter blade 4. Preferably, a plurality of sealing rings are arranged around the large-diameter end of the plunger, and the sealing rings are used to achieve the mutual sealing fit with the inner wall of the cavity 10. A sealing cover 18 is installed at the lower end of the matrix 3 above the cutter blade 4. A through hole for the small-diameter end of the plunger 11 to pass through is opened in the middle of the sealing cover 18, and a sealing ring for mutually sealing with the small-diameter end of the plunger 11 is arranged on the inner wall of the through hole of the sealing cover 18.

[0035] Combined with the attached Figure 3 , the small-diameter end of the plunger 11 and the cutter blade 4 are connected by a pin shaft, so that the cutter blade 4 can rotate within a small range in the movement gap 41 when the plunger 11 moves up and down.

[0036] Preferably, the rotation angle range of the cutter blade 4 at the crown of the matrix 3 is between 0-8°, which can not only change the cutting angle of the cutting teeth 5 on the cutter blade 4 (or the contact area between the cutting teeth and the rock and soil mass), but also maintain the cutting sharpness of the cutting teeth on the rock and soil mass.

[0037] Combined with the attached Figure 2 , the attached Figure 4 and the attached Figure 5, in some embodiments, the first channel 12 and the second channel 13 are respectively provided with a plug 15. An installation cavity 21 is provided on the carcass 3 and is in communication with the first channel 12 and the second channel 13 respectively. One end of the plug 15 passes through the installation cavity 21 and is adapted to the first channel 12 or the second channel 13. The other end of the plug 15 is adapted to a cooling channel 14 provided in the carcass and used for inputting drilling fluid. A spring 19 sleeved around the plug 15 is provided in the installation cavity 21. When there is no drilling fluid in the cooling channel 14, the spring 19 makes one end of the plug 15 located in the cooling channel 14, and the other end of the plug 15 is flush with the inner wall of the first channel 12 and / or the second channel 13. When drilling fluid is input into the cooling channel 14, one end of the plug 15 extends into the first channel 12 and / or the second channel 13, and the other end of the plug 15 is flush with the inner wall of the cooling channel 14. Thus, the movement of the plug 15 is directly controlled by the drilling fluid in the cooling channel 14. That is to say, during the use of the present invention, when the angle of the cutter blade 4 is adjusted, no drilling fluid is introduced into the cooling channel 14, so that the first channel 12 and the second channel 13 for adjusting the movement position of the plunger 11 are unblocked. After the angular position of the cutter blade 4 is adjusted, drilling fluid is first input into the cooling channel 14. Under the action of the drilling fluid with a certain pressure, the plug 15 is driven to move towards the first channel 12 and the second channel 13, and then the first channel 12 and the second channel 13 are locked, so as to keep the hydraulic oil in the cavities 10 on both sides of the plunger 11 stable, thereby maintaining the stability of the cutter blade state.

[0038] Combined with the attached Figure 4 and the attached Figure 5 , in some embodiments, an impact surface is provided at one end of the plug 15 close to the cooling channel 14. The impact surface is used for when the drilling fluid enters the cooling channel, the drilling fluid impacts the impact surface of the plug 14, so that the plug 15 overcomes the resistance of the spring 19 and extends into the first channel 12 and / or the second channel 13.

[0039] In some embodiments, sealing rings for sealing with the installation cavity 21 are provided at both ends of the plug 15, so as to prevent the drilling fluid in the cooling channel 14 from being mixed and contaminated with the hydraulic oil in the first channel 12 and the second channel 13 due to the movement of the plug 15.

[0040] Combined with the attached Figure 4 and the attached Figure 5, preferably, the plug 15 is in a "dumbbell" shape with a smaller middle part and larger ends, and the spring 19 is installed at the middle region of the plug 15. During the specific implementation process, the spring 19 is provided with a mounting plate 20. Elastic pins are installed on the side wall of the mounting plate 20, and locking pin holes adapted to the elastic pins are provided on the inner wall of the installation cavity 21. The mounting plate 20 is fixed in the installation cavity 21 through the cooperation of the elastic pins and the locking pin holes; and a through hole through which the plug 15 passes is provided in the middle of the mounting plate 20, so that the fixed mounting plate 20 does not affect the movement of the plug 15.

[0041] During the specific implementation process, the plug 15 is composed of two upper and lower parts. After sleeving the mounting plate 20 and the spring on the middle region of the plug 15, the two parts of the plug can be assembled together.

[0042] Combined with the attached Figure 2 - attached Figure 5 , preferably, the drilling fluid in the cooling channel 14 first controls the opening and closing of the first channel 12 through the plug and then controls the opening and closing of the second channel through another plug, so that after the drilling fluid is introduced into the cooling channel 14, the drilling fluid can control the plugs provided for the first channel 12 and the plugs provided for the second channel in sequence, realizing the control of the first channel and the second channel. When the cutter blade is adjusted in the direction away from the joint 1, since when the plug is squeezed into the first channel 12, it will bring a certain additional pressure to the cavity 10 above the plunger 11, and when this squeezing force is transmitted to the plunger 11, it will drive the plunger 11 to make a fine adjustment, and then unload the hydraulic oil below the plunger through the unloading effect of the second channel, so as to ensure the pressure balance between the upper cavity 10 and the lower cavity of the plunger. When the cutter blade is adjusted in the direction towards the joint 1, the principle of action is similar, and it can ensure the pressure balance in the cavities 10 on both the upper and lower sides of the plunger, and will not cause the problem of pressure imbalance due to the action of the plug 15.

[0043] Combined with the attached Figure 6 , in some embodiments, two jet channels communicating with the cooling channel 14 are opened on the matrix 3 corresponding to each cutter blade 4, and the two jet channels spray out along both sides of the rotation direction of the cutter blade 4. Among them, the jet channels include a first jet channel 141 and a second jet channel 142. The first jet channel 141 sprays towards the upper side of the movable gap 41 between the cutter blade 4 and the matrix 3, and the second jet channel 142 sprays towards the side surface of the movable gap 1. On the one hand, spraying is carried out from two directions through the first jet channel and the second jet channel to ensure that all the cutting teeth 5 on the cutter blade 4 can be covered and cooled by the drilling fluid, and at the same time, it also avoids debris during the drilling process from entering the movable gap 41, thereby ensuring the position adjustability of the cutter blade 4.

[0044] During the use of the core bit for rapid core acquisition in geological exploration of the present invention, when encountering a soft formation, hydraulic oil is injected into the cavity through the first channel, and then the plunger is pushed to move towards the cutter blade. Under the action of the plunger, the cutter blade rotates along the rotating shaft on the matrix (i.e., when the plunger pushes the cutter blade outwards), so as to adjust the angle of the whole cutter blade, enabling more cutting surfaces of the cutting teeth on the cutter blade to be used for cutting, thereby improving the cutting efficiency of the cutting teeth on the cutter blade and further increasing the drilling speed (mainly when the geology becomes soft); when the rotation of the cutter blade is not required, the external hydraulic system controls the reverse movement of the plunger (i.e., the plunger moves along the direction towards the joint), and together with the resetting action of the torsion spring, the cutter blade is driven to rotate along the direction towards the joint, making the cutting teeth on the cutter blade in the original state (i.e., the cutting surface area for cutting on the cutting teeth is the smallest) for cutting hard formations (such as rocks). In summary, the core bit for rapid core acquisition in geological exploration of the present invention can adjust the angle of the cutter blade according to the geological conditions to change the cutting area of the cutting teeth on the cutter blade, so as to drill for different geological structures, achieve the purpose of improving the drilling efficiency, and further rapidly acquire the core.

[0045] Meanwhile, during the use of the present invention, due to the rotation of the cutter blade driving the cutting teeth to rotate as well, different positions on the cutting teeth are used for cutting. While improving the cutting efficiency, it can also delay the wear of the cutting teeth, increase the service life of the cutting teeth, reduce the frequency of replacing the core bit, and further achieve the purpose of improving the drilling efficiency.

[0046] The present invention is provided with cocks in the first channel and the second channel, and the movement of the cocks is affected by the working state of the drilling fluid. When the drilling fluid is introduced into the cooling channel, the drilling fluid pushes the cocks to move towards the first channel and the second channel, thereby closing and locking the first channel and the second channel, and further fixing the position of the plunger, preventing the cutter blade and the cutting teeth on the cutter blade from rotating along the rotating shaft during the cutting process, and ensuring the locking of the position of the cutting teeth after adjustment.

Claims

1. A core bit for quickly obtaining cores in geological exploration, comprising a sub and a bit body connected to each other. The sub is used to connect with a drill pipe. The bit body includes a matrix and a plurality of cutter wings evenly arranged on the crown of the matrix. A number of cutting teeth are installed on the cutter wings. A core channel is formed in the middle of the bit body, and it is characterized in that, The angular position of the cutter blade on the matrix is adjustable; A support base is provided on the matrix. The cutter blade is mounted on the support base via a spindle. An adjusting mechanism for driving the cutter blade to rotate on the support base is mounted on the cutter blade. The adjusting mechanism includes a cavity opened along the length direction of the matrix. A plunger that is hermetically sealed with the inner wall of the cavity and can slide in the cavity is arranged in the cavity. One end of the plunger passes through the cavity and is connected to the cutter blade. A first channel and a second channel are further provided on the matrix. The first channel and the second channel are respectively communicated with the cavity on both sides of the plunger. The first channel and the second channel are communicated with an external hydraulic system via pipelines; the center of gravity position of the cutter blade is closer to the joint than the rotation axis of the cutter blade; a torsion spring for providing a pre-tightening force in the direction of the joint to the cutter blade is sleeved on the rotation axis; Cocks are respectively arranged in the first channel and the second channel. An installation cavity communicated with the first channel and the second channel respectively is provided on the matrix. One end of the cock passes through the installation cavity and is adapted to the first channel or the second channel. The other end of the cock is adapted to a cooling channel arranged in the matrix and used for inputting drilling fluid. A spring sleeved on the periphery of the cock is arranged in the installation cavity; when there is no drilling fluid in the cooling channel, the spring makes one end of the cock located in the cooling channel, and the other end of the cock flush with the inner wall of the first channel and / or the second channel; when the drilling fluid is input into the cooling channel, one end of the cock extends into the first channel and / or the second channel, and the other end of the cock is flush with the inner wall of the cooling channel.

2. The core bit for quickly obtaining cores in geological exploration according to claim 1, wherein An impact surface is arranged at one end of the cock close to the cooling channel. The impact surface is used for when the drilling fluid enters the cooling channel, the drilling fluid impacts the impact surface of the cock, so that the cock overcomes the resistance of the spring and extends into the first channel and / or the second channel.

3. The core bit for rapidly obtaining core samples in geological exploration according to claim 1 or 2, characterized in that, Sealing rings for hermetically sealing the installation cavity are respectively arranged at both ends of the cock.

4. The core bit for quickly obtaining cores in geological exploration according to claim 1, characterized in that, Two jet channels communicated with the cooling channel are opened on the matrix corresponding to each cutter blade, and the two jet channels spray out along both sides of the rotation direction of the cutter blade.

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