CN218934407U

CN218934407U - Drilling device

Info

Publication number: CN218934407U
Application number: CN202320067652.1U
Authority: CN
Inventors: 樊培贺; 魏迎雨
Original assignee: Sixth Geological Brigade Of Shandong Bureau Of Geology And Mineral Resources Exploration And Development
Current assignee: Sixth Geological Brigade Of Shandong Bureau Of Geology And Mineral Resources Exploration And Development
Priority date: 2023-01-10
Filing date: 2023-01-10
Publication date: 2023-04-28
Anticipated expiration: 2033-01-10

Abstract

The utility model provides a drilling device which solves the problems still existing in the use process of the prior art. Including the probing base plate, run through and threaded rotation is connected with the lift lead screw between the top surface of probing base plate and the bottom surface, run through and upper and lower slidable mounting has the lift slide bar between the top surface of probing base plate and the bottom of lift slide bar is connected with the lift ring that is located probing base plate below, the coaxial rotation in bottom of lifting plate is connected with the sampling tube of lateral surface installation auger and bottom open-ended, the middle part of probing base plate is run through there is the drilling rod, the bottom slip of drilling rod runs through the top of sampling tube and is connected with the drill bit that is located sampling tube opening part and inside hollow, it has a plurality of circumference evenly distributed's open and shut groove to run through on the lateral surface of drill bit, all be provided with fan-shaped drill bit board in every open and shut groove, the bottom of every drill bit board all rotates with the groove that opens and shuts to be connected that corresponds. The utility model can sample deep soil, and the soil sample can clearly reflect geological conditions.

Description

Drilling device

Technical Field

The utility model relates to the technical field of geological exploration, in particular to a drilling device.

Background

During geological prospecting, the drilling equipment is required to be used for drilling geology, the surface of the geology is drilled downwards, along with the continuous deepening of the drilling depth, the soil in the geology can be exposed, then the sampling device is used for sampling the soil in the drilled hole, the existing drilling device is generally provided with a drill bit capable of drilling the inside of the geology and discharging the soil in the geological layer to the ground, but the existing drilling device cannot directly sample the soil in the drilled hole in the use process, the drilling equipment is required to be taken out from the drilled hole after drilling is finished, the soil in the drilled hole is cleaned, and the sampling device can be used for sampling the soil in the depth below the drilled hole, for example: when a sample with a certain depth in the geological layer needs to be sampled (for example, when the sampling depth is 100 cm), drilling equipment is required to drill into the geological layer to drill out soil with a depth above a target depth (namely, soil with a depth above 100 cm), then the soil with the target depth can be sampled, the whole sampling process not only needs to carry a drilling device and a sampling device, but also needs to be replaced in the operation process, so that the drilling and sampling process of geological prospecting becomes complicated.

Currently, the market discloses the publication number: the Chinese patent of CN211692299U comprises a frame, wherein the frame comprises an annular base plate, four upright rods are fixedly arranged on the top of the annular base plate in an equidistant surrounding manner, a top plate is fixedly arranged on the top of each of the four upright rods, sliding blocks are connected to the four upright rods in a sliding manner, a fixed plate is fixedly arranged on the top of each of the four sliding blocks, the fixed plate is positioned between one side opposite to the annular base plate and the top plate, a drilling motor is fixedly arranged on the top of the fixed plate, an output shaft of the drilling motor is fixedly connected with a drilling shaft through a coupler, a drill bit is detachably fixed at the bottom of the drilling shaft, a lifting mechanism for driving the fixed plate to slide up and down along the four upright rods is arranged on the frame, and a sampling mechanism for sampling geological substances generated in the drilling process is arranged on the surface of the drilling shaft; above-mentioned structure can be through the rotation of drill bit to the geological formation is bored to smash the inside soil of drilling, then can collect the soil through pivoted auger blade and get into inside the sampling mechanism, thereby realize the effect of boring while sampling.

However, the bottom of auger blade in above-mentioned structure is in the below of spacing urceolus all the time, consequently, when the auger blade begins to get into the moment of drilling, will collect soil and get into spacing urceolus inside, thereby make the sample after the end, the soil of spacing urceolus inside is earth's surface to the soil of sampling depth, and when spacing urceolus inside is full of soil, but when not reaching the sampling depth yet, still need take out spacing urceolus and clear up its inside soil and bore the inside sample of drilling again, and because the drill bit breaks up soil in the drilling process entirely, consequently the soil of being sampled in the spacing urceolus is the hack too, can not accurately reflect the soil condition of each degree of depth of geological layer, therefore, the effect of sampling while can be realized to above-mentioned sampling tool, nevertheless still exists in the use and can't once only accomplish the sample to the soil of great depth, and the soil of taking out is the hack form, it is difficult to reflect the distribution situation of geological soil in the geological layer accurately.

Based on the problems, the present utility model provides a drilling device to solve the problems.

Disclosure of Invention

Aiming at the situation, in order to overcome the defects of the prior art, the utility model provides the drilling device, which effectively solves the problem that the prior art still cannot sample the soil at a deeper position at one time in the use process, and the taken soil is in a crushed soil state, so that the distribution condition of the soil in a geological layer is difficult to accurately reflect.

The utility model provides a drilling device, includes circular shape probing base plate, the bottom edge rotation of probing base plate installs four circumference evenly distributed's supporting leg, run through and threaded rotation is connected with the lift lead screw between the top surface of probing base plate and the bottom surface, run through and upper and lower slidable mounting has the lift slide bar between the top surface of probing base plate and the bottom of lift slide bar, the bottom of lift lead screw and lift slide bar is connected with the lift ring that is located probing base plate below jointly, the coaxial rotation in bottom of lifting plate is connected with the auger of lateral surface installation heliciform and bottom open-ended sampling tube, the middle part of probing base plate runs through there is the boring bar, the bottom of boring bar slides and runs through the top of sampling tube and be connected with the drill bit that is located sampling tube opening part and inside hollow, it has a plurality of circumference evenly distributed's open-shut grooves to run through on the lateral surface of drill bit, every open-shut inslot all is provided with fan-shaped drill bit board, every the bottom of drill bit board all rotates with the groove that opens and shuts and is connected.

Preferably, the outer diameter of the drill bit is smaller than the inner diameter of the sampling tube, and a plurality of drilling cutting boards with evenly distributed circumferences are fixedly arranged at the bottom of the sampling tube.

Preferably, the top of lift lead screw and lift slide bar is connected with the roof jointly, the lift lead screw rotates with the roof to be connected, lift slide bar and roof fixed connection, fixed mounting has the elevator motor who is connected with the lift lead screw on the roof.

Preferably, the top of the drilling rod penetrates through the top plate and is fixedly connected with the handle, two positioning rings which are arranged up and down are arranged on the outer side face of the top end of the drilling rod, a positioning groove is formed in the top of the top plate, a positioning block matched with the positioning ring is slidably mounted in the positioning groove, and a spring piece is fixedly connected between the positioning block and the positioning groove.

Preferably, the top of the drilling base plate is rotatably provided with a rotary worm wheel coaxially surrounding the outer side of the drilling rod, the outer side surface of the drilling rod is provided with a rotary long groove along the axial direction of the drilling rod, the inner side surface of the rotary worm wheel is fixedly provided with a rotary key block positioned in the rotary long groove, the top of the drilling base plate is fixedly provided with a rotary motor, and the rotary shaft of the rotary motor is fixedly provided with a rotary worm meshed with the rotary worm wheel.

Preferably, the through hole has been run through in the bottom middle part of drill bit, coaxial slidable mounting has the pole that opens and shuts in the through hole, the one end fixed mounting that the pole that opens and shuts is located the drill bit is inside has the dish that opens and shuts, the top of dish that opens and shuts rotates and installs a plurality of circumference evenly distributed's the connecting rod that opens and shuts, every the other end of connecting rod that opens and shuts rotates between the side of one of them drill bit board orientation drill bit inside respectively, the one end that the pole that opens and shuts is located the drill bit outside is the cusp, the return spring of installing in the pole outside that opens and shuts is established to fixedly connected with cover between the bottommost of dish and drill bit medial surface.

Preferably, the bottom of each supporting leg is in threaded connection with a supporting threaded rod, and the bottom of each supporting threaded rod is pointed.

According to the utility model, the geological layer can be drilled through the drill bits, the soil is smashed through the drill bit plates, meanwhile, the drill bits can drive the sampling tube to drill into the geological layer together, the smashed soil can be discharged out of the drill hole through the auger on the outer side of the drill bit, at the moment, the soil does not enter the sampling tube, so that the drill bit and the sampling tube can drill into deeper parts of the geological layer for sampling, when the drill bit reaches the sampling depth, the drill bits can be moved upwards to the top of the sampling tube to open the bottom of the sampling tube, and can continue to drill into the soil below the drill hole, so that the columnar soil enters the sampling tube, after sampling is completed, the columnar soil is taken out from the sampling tube, the device not only can realize the effect of drilling while sampling, but also can sample the soil in deeper layers, and the taken soil sample keeps a complete columnar shape, and can clearly reflect the distribution condition of the soil in the geological layer.

Drawings

Fig. 1 is a schematic perspective view of the present utility model.

Fig. 2 is a schematic front view of the present utility model.

Fig. 3 is a schematic perspective view of the present utility model.

FIG. 4 is a schematic perspective view of a drill bit of the present utility model positioned inside a sampling tube.

Fig. 5 is an enlarged view of the utility model at a in fig. 1.

Fig. 6 is an enlarged view of the present utility model at B in fig. 1.

Fig. 7 is an enlarged view of the present utility model at C in fig. 3.

Fig. 8 is an enlarged view of the utility model at D in fig. 4.

Detailed Description

The foregoing and other features, aspects and advantages of the present utility model will become more apparent from the following detailed description of embodiments of the present utility model when taken in conjunction with the accompanying drawings, wherein like reference characters refer to the same parts throughout the different views.

Exemplary embodiments of the present utility model will be described below with reference to the accompanying drawings.

The first embodiment of the utility model is a drilling device, which comprises a circular drilling basal disc 1, four supporting legs 2 with evenly distributed circumference are rotatably arranged at the edge of the bottom of the drilling basal disc 1, the drilling basal disc 1 can be placed above a position to be drilled through the supporting legs 2, a lifting screw rod 3 penetrates through and is in threaded rotation connection with the top surface and the bottom surface of the drilling basal disc 1, a threaded hole is arranged on the left side of the axis of the drilling basal disc 1, the lifting screw rod 3 is in threaded fit with the threaded hole, the lifting screw rod 3 can vertically move on the drilling basal disc 1 when rotating, a lifting slide rod 4 penetrates through and is vertically and slidably arranged between the top surface and the bottom surface of the drilling basal disc 1, a slide hole is arranged on the right side of the axis of the drilling basal disc 1, the lifting slide rod 4 is in vertical sliding fit with the slide hole, a lifting ring 5 positioned below the drilling basal disc 1 is commonly connected with the bottom ends of the lifting screw rod 3 and the lifting slide rod 4, the lifting screw rod 3 is rotationally connected with the top of the lifting ring 5, the lifting slide rod 4 is fixedly connected with the top of the lifting ring 5, the lifting ring 5 can be driven to move up and down through the rotation time screw rod 3, meanwhile, the lifting slide rod 4 can also slide up and down in a slide hole, the bottom of the lifting disk 5 is coaxially rotationally connected with a sampling cylinder 6 with a spiral auger arranged on the outer side surface and an opening at the bottom, the sampling cylinder 6 can rotate at the bottom of the lifting disk 5, the lifting disk 5 can drive the sampling cylinder 6 to move up and down, the middle part of the drilling basal disk 1 is penetrated with a drilling rod 7, the middle part of the drilling basal disk 1 is provided with a through hole, the drilling rod 7 can move freely in the through hole, namely can rotate and also move up and down, the bottom of the drilling rod 7 slides through the top of the sampling cylinder 6 and is connected with a drill bit 8 which is positioned at the opening of the sampling cylinder 6 and hollow inside, the drill rod 7 is in sliding connection with the top of the sampling tube 6, namely the drill rod 7 can drive the sampling tube 6 to synchronously rotate with the drill bit 8 when rotating, the drill rod 7 can slide up and down in the middle of the sampling tube 6 when moving up and down, and drives the drill bit 8 to move up to the inside of the sampling tube 6, a plurality of circumferentially uniformly distributed open and close grooves 9 penetrate through the outer side face of the drill bit 8, each open and close groove 9 is internally provided with a fan-shaped drill bit plate 10, the tip of the drill bit plate 10 is located at the bottom of the open and close groove 9, and each bottom of the drill bit plate 10 is rotationally connected with the corresponding open and close groove 9, so that the top of the drill bit plate 10 can outwards stretch out or retract into the drill bit 8 in the open and close groove 9.

When the drilling device is used, firstly, the drilling basal disc 1 is fixed at a position where drilling sampling is required, then the lifting ring 5 is downwards placed and moved by the rotating time screw rod 3, meanwhile, the drill rod 7 is rotated and simultaneously drives the drill bit 8 and the sampling tube 6 to rotate, so that the drill bit 8 and the sampling tube 6 can drill into the geological formation, the drill bit 8 can break the soil in the geological formation through the plurality of drill bit plates 10, the auger on the outer side of the sampling tube 6 can discharge the broken soil to the ground, when the depth of the required sampling is reached, the drill rod 7 can be upwards moved, the drill bit 8 is driven to upwards move to the inside of the sampling tube 6, the plurality of drill bit plates 10 on the outer side of the drill bit 8 can inwards contract under the driving of a follow-up structure, the drill bit 8 cannot enter the sampling tube 6, when the drill bit 8 moves to the topmost end of the inside of the sampling tube 6, the drill rod 7 is continuously rotated, the cylindrical sampling tube 6 can downwards drill, the soil can enter the inside of the sampling tube 6, the soil is enabled to be in the cylindrical sampling tube 6, the soil is in the soil to be in the soil, the inside the sampling tube 6 is in the soil to be in the depth of the soil to be sampled, and the soil is clearly distributed in the geological formation, and the soil is clearly distributed in the soil is taken out, and the soil is in the soil to be clearly.

In the second embodiment, on the basis of the first embodiment, the outer diameter of the drill bit 8 is smaller than the inner diameter of the sampling tube 6, the maximum diameter end of the drill bit 8 can be attached to the inner side surface of the sampling tube 6 and move up and down in the sampling tube 6, a plurality of drilling blades 28 with evenly distributed circumferences are fixedly mounted at the bottom of the sampling tube 6, and after the drill bit 8 enters the sampling tube 6, the sampling tube 6 can continue to drill downwards through the plurality of drilling blades 28.

The third embodiment is that, on the basis of the first embodiment, the top of the lifting screw rod 3 and the top of the lifting slide rod 4 are connected with a top plate 11 together, the lifting screw rod 3 is rotationally connected with the top plate 11, the lifting slide rod 4 is fixedly connected with the top plate 11, a lifting motor 12 connected with the lifting screw rod 3 is fixedly installed on the top plate 11, the lifting motor 12 is connected with a storage battery, and the lifting screw rod 3 can be driven to rotate when the lifting motor is powered by a portable power supply, so that the lifting ring 5 is driven to move up and down.

In the fourth embodiment, on the basis of the third embodiment, the top of the drilling rod 7 penetrates through the top plate 11 and is fixedly connected with the handle 13, the drilling rod 7 can freely move in the top plate 11, not only can rotate, but also can move up and down, two positioning rings 14 which are arranged up and down are arranged on the outer side surface of the top end of the drilling rod 7, the distance between the two positioning rings 14 is equal to the distance that the drill bit 8 moves from the bottom of the sampling tube 6 to the top of the sampling tube, a positioning groove 15 is arranged at the top of the top plate 11, a positioning block 16 matched with the positioning ring 14 is slidably mounted in the positioning groove 15, a spring piece 17 is fixedly connected between the positioning block 16 and the positioning groove 15, when the drill bit 8 is positioned at the bottom opening of the sampling tube 6, the positioning block 16 can be matched with the positioning ring 14 positioned above, the locating piece 16 inserts in the holding ring 14 under the elasticity of spring leaf 17 for drilling rod 7 can not reciprocate, but drilling rod 7 can rotate this moment, and locating piece 16 then rotates with holding ring 14 relatively during the rotation, and drill bit 8 and sampling tube 6 can simultaneously down carry out the probing, when reaching the sample degree of depth, can pull locating piece 16 makes its separation with holding ring 14, can upwards remove drilling rod 17 this moment, and can drive drill bit 8 into sampling tube 6 inside, when drill bit 8 moves to the inside topmost of sampling tube 6 (refer to the position of fig. 4, 8), the holding ring 14 of locating below then is in the height of locating piece 16, and locating piece 16 then can insert in this holding ring 14, thereby carry out the spacing of upper and lower direction to drilling rod 7, drilling rod 7 can continue to rotate and drive sampling tube 6 rotation and bore the sample can at this moment.

In the fifth embodiment, on the basis of the fourth embodiment, a rotary worm wheel 18 coaxially surrounding the outside of the drilling rod 7 is rotatably installed at the top of the drilling base plate 1, the inner diameter of the rotary worm wheel 18 is larger than the outer diameter of the drilling rod 7, the rotary worm wheel 18 can rotate outside the drilling rod 7, a rotary long groove 19 is formed in the outer side surface of the drilling rod 7 along the axial direction of the rotary worm wheel, a rotary key block 20 located in the rotary long groove 19 is fixedly installed on the inner side surface of the rotary worm wheel 18, when the rotary worm wheel 18 rotates, the rotary worm wheel 20 and the rotary long groove 19 can drive the drilling rod 7 to rotate through the cooperation of the rotary key block 20 and the rotary long groove 19, and when the drilling rod 7 moves up and down, the rotary long groove 19 and the rotary key block 20 relatively slide, so that the rotary worm wheel 18 can always drive the drilling rod 7 to rotate, a rotary motor 21 is fixedly installed at the top of the base plate 1, a portable power supply is connected to the rotary worm 21, a rotary worm 22 meshed with the rotary shaft 18 is fixedly installed on the outer side surface of the rotary motor 21, the rotary worm 21 can drive the rotary worm 22 to rotate, and when the rotary worm 22 rotates, the rotary worm wheel 22 and the rotary worm wheel 22 drives the rotary worm wheel 18 to rotate, the rotary worm 21 can drive the rotary worm wheel 21 to rotate along with the rotary worm 18 to rotate along with the rotary worm wheel 8, and the rotary worm wheel 7, and the rotary worm 8 when the rotary worm 21 rotates down and the rotary worm 7.

In the sixth embodiment, on the basis of the first embodiment, a through hole is formed in the middle of the bottom end of the drill bit, an opening and closing rod 24 is coaxially slidably mounted in the through hole, the opening and closing rod 24 can move up and down in the through hole, an opening and closing disc 25 is fixedly mounted at one end of the opening and closing rod 24 located in the drill bit 8, the opening and closing disc 25 can be driven to move up and down in the drill bit 8 when the opening and closing rod 24 moves up and down, a plurality of opening and closing connecting rods 26 with evenly distributed circumferences are rotatably mounted at the top of the opening and closing disc 25, the other end of each opening and closing connecting rod 26 is rotatably connected with the side surface of one of the drill bit plates 10 facing the inside of the drill bit 8, when the opening and closing rod 24 moves towards the inside of the drill bit 8, the plurality of drill bit plates 10 can be pushed outwards through the opening and closing connecting rods 26, so that the plurality of drill bit plates 10 can extend out of the plurality of opening and closing grooves 9 respectively when the opening and closing rod 24 moves down, the plurality of drill bit plates 10 can be pulled to move into the drill bit 8 through the plurality of opening and closing connecting rods 26, one end of the opening and closing rod 24 positioned outside the drill bit 8 is pointed, a reset tension spring 27 sleeved and installed outside the opening and closing rod 24 is fixedly connected between the opening and closing plate 25 and the bottommost part of the inner side surface of the drill bit 8, under the action of the reset tension spring 27, the bottom end of the opening and closing rod 24 is positioned far away from the bottom of the drill bit 8, at the moment, the plurality of drill bit plates 10 are positioned inside the drill bit 8, when the drill bit 8 moves downwards and comes into contact with the ground, the opening and closing rod 24 can be pressed and prolonged to the inside of the drill bit 8 by the reset tension spring 27, so that the opening and closing plate 25 moves upwards and drives the plurality of drill bit plates 10 to extend outwards, the drill bit 8 can break soil through the plurality of drill bit plates 10 when rotating, and the lifting screw rod 3 always provides downward pressure for the drill bit 8, so that the opening and closing rod 24 is positioned inside the drill bit 8 all the time, when reaching the sampling depth, when the drill bit 8 is moved upwards through the drilling rod 7 to enter the sampling tube 6, the opening and closing rod 24 at the bottom of the drill bit 8 loses downward pressure, and moves downwards to reset under the elasticity of the reset spring 27, so that the opening and closing disc 25 drives the drill bit plates 10 to reset towards the inside of the drill bit 8 through the plurality of opening and closing connecting rods 26, and the drill bit 8 can smoothly enter the sampling tube 6 and cannot be blocked by the plurality of drill bit plates 10.

In a seventh embodiment, on the basis of the first embodiment, the bottom of each supporting leg 2 is threaded and connected with a supporting threaded rod 29, the bottom of each supporting threaded rod 29 is pointed, and by rotating four supporting threaded rods 29, the respective heights of the four supporting legs 2 can be adjusted, so that the drilling base plate 1 can be placed on a flat or hollow ground for use.

Claims

1. The utility model provides a drilling device, includes circular shape probing base (1), four circumference evenly distributed's supporting leg (2) are installed in the bottom edge rotation of probing base (1), a serial communication port, run through and threaded rotation is connected with lift lead screw (3) between the top surface and the bottom surface of probing base (1), run through and slidable mounting has lift slide bar (4) from top to bottom between the top surface and the bottom surface of probing base (1), the bottom of lift lead screw (3) and lift slide bar (4) is connected with lift ring (5) that are located probing base (1) below jointly, the bottom coaxial rotation of lift ring (5) is connected with auger and bottom open-ended sampling tube (6) of lateral surface installation heliciform, the middle part of probing base (1) runs through and has drilling rod (7), the bottom slip of drilling rod (7) runs through the top of sampling tube (6) and is connected with and is located sampling tube (6) opening and inside hollow drill bit (8), run through a plurality of circumference evenly distributed's lift groove (9) on the lateral surface of drill bit (8), every fan-shaped groove (9) that opens and shuts corresponds in every setting up and down the fan-shaped groove (10) and every rotates the groove (10).

2. Drilling device according to claim 1, wherein the outer diameter of the drill bit (8) is smaller than the inner diameter of the sampling tube (6), and a plurality of drilling blades (28) uniformly distributed on the circumference are fixedly arranged at the bottom of the sampling tube (6).

3. Drilling device according to claim 1, characterized in that the top of the lifting screw rod (3) and the top of the lifting slide rod (4) are jointly connected with a top plate (11), the lifting screw rod (3) is rotationally connected with the top plate (11), the lifting slide rod (4) is fixedly connected with the top plate (11), and the top plate (11) is fixedly provided with a lifting motor (12) connected with the lifting screw rod (3).

4. A drilling device according to claim 3, characterized in that the top of the drilling rod (7) penetrates through the top plate (11) and is fixedly connected with the handle (13), two positioning rings (14) which are arranged up and down are arranged on the outer side surface of the top end of the drilling rod (7), a positioning groove (15) is arranged on the top of the top plate (11), a positioning block (16) matched with the positioning ring (14) is slidably arranged in the positioning groove (15), and a spring piece (17) is fixedly connected between the positioning block (16) and the positioning groove (15).

5. Drilling device according to claim 4, characterized in that the top of the drilling base plate (1) is rotatably provided with a rotary worm wheel (18) coaxially surrounding the outside of the drilling rod (7), the outside surface of the drilling rod (7) is provided with a rotary long groove (19) along the axial direction, the inside surface of the rotary worm wheel (18) is fixedly provided with a rotary key block (20) positioned in the rotary long groove (19), the top of the drilling base plate (1) is fixedly provided with a rotary motor (21), and the rotary shaft of the rotary motor (21) is fixedly provided with a rotary worm (22) meshed with the rotary worm wheel (18).

6. Drilling device according to claim 1, characterized in that the middle part of the bottom end of the drill bit is penetrated with a through hole, an opening and closing rod (24) is coaxially and slidably arranged in the through hole, one end of the opening and closing rod (24) positioned in the drill bit (8) is fixedly provided with an opening and closing disc (25), the top of the opening and closing disc (25) is rotatably provided with a plurality of opening and closing connecting rods (26) with evenly distributed circumferences, the other end of each opening and closing connecting rod (26) is respectively rotatably connected with the side surface of one drill bit plate (10) facing the inside of the drill bit (8), one end of the opening and closing rod (24) positioned at the outside of the drill bit (8) is pointed, and a reset tension spring (27) arranged at the outer side of the opening and closing rod (24) is fixedly connected between the opening and closing disc (25) and the bottommost part of the inner side surface of the drill bit (8).

7. A drilling device according to claim 1, wherein the bottom of each support leg (2) is threaded with a support threaded rod (29), the bottom of each support threaded rod (29) being pointed.