Electric transmission vertical shaft drilling machine and automatic bit feeding method

Abstract

The invention relates to the technical field of geological drilling, in particular to an electric transmission vertical shaft drilling machine and an automatic bit feeding method. The electric transmission vertical shaft drilling machine comprises a base, a main motor driving unit, a vertical shaft rotating device, a winding device and a motor auxiliary driving unit, wherein the main motor driving unit, the vertical shaft rotating device, the winding device and the motor auxiliary driving unit are integrated on the base. The main motor driving unit drives a vertical shaft in the vertical shaft rotating device to rotate or drives a winding drum in the winding device to rotate. When pressure reduction drilling is carried out, the main motor driving unit drives a vertical shaft in the vertical shaft rotating device to rotate, and the motor auxiliary driving unit drives a winding drum in the winding device to rotate so as to lift a drill rod in the vertical shaft to offset part of gravity of the drill rod, so that the actual drilling pressure of the drill rod to a stratum reaches a preset value; and the operation interruption caused by stroke limitation is completely eliminated, so that the drill rod can continuously rotate and be lowered, and the drilling efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of geological drilling technology, and in particular to an electric drive vertical shaft drilling rig and an automatic drilling method. Background Technology

[0002] In the fields of geological drilling, mineral exploration and engineering survey, vertical shaft drilling rigs have become the core equipment for drilling specific depths (hundreds to thousands of meters) and specific diameter holes in strata due to their advantages of stable torque transmission and adaptability to drilling in medium-hard strata. Their operating efficiency and drilling stability directly determine the quality of exploration data acquisition and the progress of engineering construction.

[0003] The core transmission system of existing vertical spindle drilling rigs typically includes a power drive unit, a vertical spindle slewing device, and a winch device. The power drive unit can be selectively connected to either the vertical spindle slewing device or the winch device, driving the vertical spindle in the slewing device to rotate the drill rod synchronously; or it can drive the drum to rotate forward and backward to wind up and down the wire rope, thereby rapidly raising and lowering the drill rod to complete the drilling or hoisting actions. However, at greater drilling depths, the total weight of the drill string increases significantly with the number of drill rods. If drilling is carried out directly by the weight of the drill string, excessive drilling pressure can easily lead to drill bit overload and wear, drill rod bending and deformation, and even the risk of borehole collapse. Therefore, a decompression drilling mode is required.

[0004] In current decompression drilling processes, the drill pipe is typically first radially clamped to the outer wall of the drill pipe using a chuck to fix its axial position. Then, a hydraulic cylinder pushes the drill pipe, applying an upward lifting force to counteract some of the drill string's weight, thus controlling the actual drilling pressure on the formation within a preset range. During decompression drilling, the drill pipe needs to be continuously lowered. However, due to the stroke limitation of the hydraulic cylinder, when the moving end of the hydraulic cylinder reaches its stroke limit, the drill pipe rotation must be paused. The chuck must be controlled to release the drill pipe, the moving end of the hydraulic cylinder must return to its initial position, the chuck must re-clamp the drill pipe, and the cylinder must apply the lifting force again. This process needs to be repeated, significantly reducing overall drilling efficiency. Furthermore, during this process, the drill pipe is prone to axial movement or slight radial offset. This not only disturbs the already formed hole wall but also increases the coaxiality deviation between the drill pipe and the vertical shaft, further exacerbating vibration during drill pipe rotation and reducing the stability and safety of the drilling operation. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides an electric drive vertical shaft drilling rig and an automatic drilling method, which solves the technical problem of low drilling efficiency due to pressure reduction.

[0007] (II) Technical Solution

[0008] To achieve the above objectives, the main technical solutions adopted by the present invention include:

[0009] This invention provides an electrically driven vertical shaft drilling rig, including a base and a main motor drive unit, a vertical shaft rotation device, and a winch device integrated on the base, as well as a motor auxiliary drive unit. The main motor drive unit drives the vertical shaft in the vertical shaft rotation device to rotate or drives the drum in the winch device to rotate. When tripping, the main motor drive unit drives the drum in the winch device to rotate in a first direction. When drilling down, the main motor drive unit drives the drum in the winch device to rotate in a second direction. When decompression drilling is performed, the main motor drive unit drives the vertical shaft in the vertical shaft rotation device to rotate, and the motor auxiliary drive unit drives the drum in the winch device to rotate, so as to lift the drill rod in the vertical shaft to offset part of its weight, thereby making the actual drilling pressure of the drill rod on the formation reach a preset value.

[0010] Preferably, a steel wire rope is wound on the drum, and one end of the steel wire rope is connected to the drill rod through a power faucet to drive the drill rod to rise and fall.

[0011] Preferably, it also includes a hydraulic unit; the hydraulic unit is used to drive the chuck in the vertical spindle rotation device to clamp or release the drill rod inside the vertical spindle.

[0012] Preferably, the winch includes a braking unit; the braking unit is used to brake the drum in the winch.

[0013] Preferably, the winch further includes an input shaft, a drum, and two support seats; the drum is sleeved on the input shaft and rotates relative to the input shaft, the input shaft is connected to the first end of the drum through a planetary gear unit, and the two ends of the input shaft are rotatably mounted on the base through the two support seats respectively; the motor auxiliary drive unit includes an auxiliary motor, an auxiliary gear disposed at the output end of the auxiliary motor, and a first internal gear ring disposed in the second end of the drum, the auxiliary gear and the first internal gear ring selectively mesh; when performing decompression drilling, the auxiliary motor drives the auxiliary gear to rotate so that the first internal gear ring drives the drum to rotate in a first direction.

[0014] Preferably, it further includes a switching unit; the switching unit includes a shift fork, a bearing, and a telescopic drive; the inner ring of the bearing is sleeved on the connecting part of the auxiliary gear, the auxiliary gear is sleeved on the output end of the auxiliary motor, and the auxiliary gear can move along the axis of the output end of the auxiliary motor; the shift fork is connected to the outer ring of the bearing; the fixed end of the telescopic drive is connected to the support base, and the moving end of the telescopic drive is connected to one end of the shift fork; the telescopic drive drives the auxiliary gear to move along the axis of the output end of the auxiliary motor through the shift fork, so that the auxiliary gear meshes or disengages with the first internal gear ring.

[0015] Preferably, the planetary gear unit includes a sun gear, a second internal gear ring, a planet carrier, and multiple planetary gears, with the multiple planetary gears connected to one side of the planet carrier; the sun gear is sleeved on the input shaft, the second internal gear ring is disposed at the first end of the drum, the sun gear meshes with the multiple planetary gears, and the multiple planetary gears drive the second internal gear ring to rotate.

[0016] Preferably, the planetary gear unit further includes a lifting clamp; the lifting clamp is opposite to the outer edge of the planet carrier and is used to clamp or release the planet carrier.

[0017] Preferably, the auxiliary motor is a 5.5KW variable frequency motor.

[0018] The present invention also provides an automatic drill feeding method, which uses the above-mentioned electric drive vertical spindle drilling machine to feed the drill through the following steps;

[0019] S1. The main motor drive unit drives the drum in the winch to rotate in the first direction to drive the drill rod to start drilling.

[0020] S2. The hoisting device stops the drum from rotating;

[0021] S3. The main motor drive unit drives the drum in the winch to rotate in the second direction to drive the drill rod to drill down.

[0022] S4. The hoisting device stops the drum from rotating;

[0023] S5. The main motor drive unit drives the vertical shaft in the vertical shaft rotation device to rotate. At the same time, the motor auxiliary drive unit drives the drum in the winch device to rotate, so as to offset part of the weight of the drill rod by lifting it, so that the actual drilling pressure reaches the preset value and pressure reduction drilling is carried out.

[0024] (III) Beneficial Effects

[0025] The beneficial effects of this invention are:

[0026] The electric drive vertical spindle drilling rig provided by this invention uses a main motor drive unit to drive the vertical spindle in the vertical spindle rotation device to rotate or to drive the drum in the winch device to rotate. When starting the drill string, the main motor drive unit drives the drum in the winch device to rotate in a first direction; when starting the drill string, the main motor drive unit drives the drum in the winch device to rotate in a second direction. Due to the large frequency conversion power of the main motor drive unit, rapid starting and stopping of the drill string is possible. During decompression drilling, the main motor drive unit drives the vertical spindle in the vertical spindle rotation device to rotate, and the motor auxiliary drive unit drives the drum in the winch device to rotate, thereby lifting the drill rod in the vertical spindle to offset part of its weight, thus ensuring that the actual drilling pressure of the drill rod on the formation reaches a preset value. During decompression drilling, this invention completely eliminates the hydraulic cylinder pushing method, providing a continuous upward lifting force through the winch device. Because the effective stroke of the wire rope in the winch device is extremely long, it completely eliminates work interruptions caused by stroke limitations, allowing the drill rod to rotate and be lowered continuously, improving drilling efficiency. At the same time, it avoids axial movement and radial displacement of the drill rod caused by frequent clamping, loosening and cylinder reset, thus ensuring good coaxiality between the drill rod and the vertical shaft, reducing vibration, protecting not only the drill rod and drill bit, but also effectively maintaining the stability of the hole wall, and greatly improving operational safety.

[0027] The automatic drilling method provided by this invention completely eliminates the hydraulic cylinder pushing scheme when performing decompression drilling. Instead, it provides a continuous upward lifting force through a winch device. Since the effective stroke of the wire rope in the winch device is extremely long, it completely eliminates the interruption of operation caused by stroke limitation, allowing the drill rod to rotate and be lowered continuously, thereby improving drilling efficiency. Attached Figure Description

[0028] Figure 1 This is a first-view structural schematic diagram of the electric drive vertical shaft drilling rig of the present invention;

[0029] Figure 2 This is a structural schematic diagram of the electric drive vertical shaft drilling rig of the present invention from a second perspective;

[0030] Figure 3 for Figure 1 A partial structural diagram of the auxiliary drive unit and winch device (auxiliary motor not shown).

[0031] Figure 4 This is a schematic diagram of the switching unit.

[0032] Figure 5 This is a schematic diagram of the planetary gear unit.

[0033] Figure 6 This is a longitudinal sectional view of the hoisting device.

[0034] [Explanation of Labels in the Attached Image]

[0035] 1: Base;

[0036] 2: Main motor drive unit;

[0037] 3: Switching unit; 31: Shift fork; 32: Bearing; 33: Telescopic drive component;

[0038] 4: Vertical shaft rotation device; 41: Vertical shaft; 42: Chuck;

[0039] 5: Hoisting device; 51: Input shaft; 52: Drum; 53: Support base; 54: Braking unit;

[0040] 6: Motor auxiliary drive unit; 61: Auxiliary motor; 62: Auxiliary gear; 63: First internal gear ring;

[0041] 7: Planetary gear unit; 71: Sun gear; 72: Second internal gear ring; 73: Planet carrier; 74: Planetary gear; 75: Lifting clamp;

[0042] 8: Hydraulic unit. Detailed Implementation

[0043] To better explain and facilitate understanding of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0044] Example 1

[0045] like Figure 1 and Figure 2 As shown in the figure, an embodiment of the present invention provides an electric drive vertical spindle drilling rig, which includes a base 1 and a main motor drive unit 2, a hydraulic unit 8, a vertical spindle rotation device 4, a winch device 5, and a motor auxiliary drive unit 6 integrated on the base 1. A steel wire rope is wound on the drum 52 of the winch device 5, and one end of the steel wire rope is connected to the drill rod via a power swivel to drive the drill rod to rise and fall. The hydraulic unit 8 is used to drive the chuck 42 in the vertical spindle rotation device 4 to clamp or release the drill rod inside the vertical spindle 41. It should be noted that in this embodiment, the chuck 42 is only used for pressurized drilling in the initial stage of drilling; it is not used during depressurized drilling.

[0046] The main motor drive unit 2 includes a main motor, a gearbox, a universal joint, and a transfer case. The power of the main motor enters the transfer case sequentially through the gearbox and the universal joint. The power is transmitted to the vertical shaft rotation device 4 through the transmission between gears in the transfer case, driving the vertical shaft 41 in the vertical shaft rotation device 4 to rotate. Alternatively, the power is transmitted to the input shaft 51 in the hoisting device 5 through the transmission between gears in the transfer case, thereby driving the drum 52 in the hoisting device 5 to rotate.

[0047] When drilling operations are initiated, the main motor drive unit 2 drives the drum 52 in the winch 5 to rotate in a first direction, thereby lifting the drill pipe. When drilling is initiated, the main motor drive unit 2 drives the drum 52 in the winch 5 to rotate in a second direction opposite to the first direction. Since electric drive vertical spindle drilling rigs are typically used for drilling operations at depths of hundreds to thousands of meters, the main motor drive unit 2, with its high-power frequency conversion output capability, can provide sufficient power for the rotation of the drum 52, thus significantly improving the speed of both initiation and descent, ultimately effectively improving overall drilling efficiency.

[0048] During decompression drilling, the main motor drive unit 2 drives the vertical shaft 41 in the vertical shaft rotation device 4 to rotate, and the motor auxiliary drive unit 6 drives the drum 52 in the winch device 5 to rotate, thereby lifting the drill rod in the vertical shaft 41 to offset part of its weight, thus ensuring that the actual drilling pressure of the drill rod on the formation reaches the preset value. In this embodiment, the hydraulic cylinder pushing scheme is completely abandoned during decompression drilling; instead, the winch device 5 provides a continuous upward lifting force. Because the effective stroke of the wire rope in the winch device 5 is extremely long, operation interruptions caused by stroke limitations are completely eliminated, allowing the drill rod to rotate and lower continuously, improving drilling efficiency. Simultaneously, it avoids axial movement and radial displacement of the drill rod caused by frequent clamping, loosening, and cylinder resetting, thus ensuring good coaxiality between the drill rod and the vertical shaft 41, reducing vibration, protecting not only the drill rod and drill bit but also effectively maintaining the stability of the borehole wall, and significantly improving operational safety.

[0049] like Figure 3 and Figure 6 As shown, the winch device 5 includes a braking unit 54, an input shaft 51, a drum 52, and two support seats 53. The braking unit 54 is used to brake the drum 52 in the winch device 5.

[0050] The two ends of the input shaft 51 are rotatably mounted on the base 1 via two support seats 53. The drum 52 is sleeved on the input shaft 51 and rotates relative to the input shaft 51. The input shaft 51 is connected to the first end of the drum 52 via the planetary gear unit 7, thereby transmitting the power of the input shaft 51 to the first end of the drum 52 through the planetary gear unit 7.

[0051] like Figure 5As shown, the planetary gear unit 7 includes a lifting clamp 75, a sun gear 71, a second internal gear ring 72, a planet carrier 73, and multiple planetary gears 74. The multiple planetary gears 74 are connected to one side of the planet carrier 73. The sun gear 71 is mounted on the input shaft 51. The second internal gear ring 72 is located inside the first end of the drum 52. The sun gear 71 meshes with the multiple planetary gears 74, and the multiple planetary gears 74 drive the second internal gear ring 72 to rotate. The lifting clamp 75 is opposite to the outer edge of the planet carrier 73 and is used to clamp or release the planet carrier 73. When the main motor drive unit 2 transmits power to the input shaft 51, and the lifting clamp 75 clamps the outer edge of the planet carrier 73, the sun gear 71 on the input shaft 51 rotates, the second internal gear ring 72 rotates, and thus the drum 52 rotates. When the lifting clamp 75 releases the planet carrier 73, the sun gear 71 does not drive the second internal gear ring 72 to rotate, and thus there is no power input to the first end of the drum 52.

[0052] like Figure 4 As shown, the motor-assisted drive unit 6 includes an auxiliary motor 61, an auxiliary gear 62, and a first internal gear ring 63. The auxiliary gear 62 is located at the output end of the auxiliary motor 61, and the first internal gear ring 63 is located inside the second end of the drum 52 and is detachably connected to the second end of the drum 52. The auxiliary gear 62 and the first internal gear ring 63 can be selectively engaged. When performing decompression drilling, the auxiliary gear 62 engages with the first internal gear ring 63, and the auxiliary motor 61 drives the auxiliary gear 62 to rotate, which in turn causes the first internal gear ring 63 to drive the drum 52 to rotate in a first direction.

[0053] The electric drive vertical spindle drilling rig also includes a switching unit 3, which includes a shift fork 31, a bearing 32, and a telescopic drive component 33. An auxiliary gear 62 is sleeved on the output end of an auxiliary motor 61, and the auxiliary gear 62 can only move along the axis of the output end of the auxiliary motor 61. The inner ring of the bearing 32 is fixedly sleeved on the connecting part of the auxiliary gear 62. The shift fork 31 is connected to the outer ring of the bearing 32. The fixed end of the telescopic drive component 33 is connected to the support base 53, and the moving end of the telescopic drive component 33 is connected to one end of the shift fork 31. The telescopic drive component 33 drives the auxiliary gear 62 to move along the axis of the output end of the auxiliary motor 61 through the shift fork 31, so that the auxiliary gear 62 meshes with or disengages from the first internal gear ring 63. It should be noted that in this embodiment, the auxiliary motor 61 is a 5.5KW variable frequency motor. Compared to high-power motors, low-power auxiliary motors 61 consume less energy during decompression drilling phases other than tripping and descent, significantly reducing overall energy consumption. In addition, low-power motors are smaller and lighter, taking up less space in the overall layout of the drilling rig and reducing the load on the support structure.

[0054] During the tripping or descent phases of drilling, the shift fork 31 in the switching unit 3 drives the auxiliary gear 62 to move along the axis of the output end of the auxiliary motor 61, so that the auxiliary gear 62 remains separated from the first internal gear ring 63. In this state, the power of the motor auxiliary drive unit 6 cannot be transmitted to the drum 52, ensuring that the drum 52 is driven solely by the main motor drive unit 2, in order to meet the stable power output requirements during the tripping and descent phases.

[0055] Example 2

[0056] This embodiment provides an automatic drill feeding method, which uses the electric drive vertical spindle drilling machine in Embodiment 1 and feeds the drill through the following steps;

[0057] S1. The main motor drive unit 2 drives the drum 52 in the winch device 5 to rotate in the first direction to drive the drill rod to start drilling.

[0058] During this process, the switching unit 3 keeps the auxiliary gear 62 in the motor auxiliary drive unit 6 separated from the first internal gear ring 63, ensuring that the motor auxiliary drive unit 6 does not input power to the drum 52, and the drum 52 is driven only by the main motor drive unit 2 to stably drive the drill rod to complete the drilling action.

[0059] S2. When the drill rod is raised to the preset position, the braking unit 54 in the winch 5 is activated, so that the drum 52 stops rotating and the drill rod is kept at the current raising position to prepare for the subsequent drilling steps.

[0060] S3. After the braking unit 54 of the winch device 5 releases the brake on the drum 52, the main motor drive unit 2 drives the drum 52 in the winch device 5 to rotate in a second direction opposite to the first direction so as to drive the drill rod to drill down.

[0061] During this process, the switching unit 3 keeps the auxiliary gear 62 in the motor auxiliary drive unit 6 separated from the first internal gear ring 63, ensuring that the motor auxiliary drive unit 6 does not input power to the drum 52, and the drum 52 is driven only by the main motor drive unit 2 to stably drive the drill rod to complete the drilling action.

[0062] S4. When the drill rod is lowered to the preset position of the stratum to be drilled, the braking unit 54 in the winch device 5 is activated, so that the drum 52 stops rotating and the drill rod is suspended at the drilling height.

[0063] S5. During decompression drilling, the lifting clamp 75 of the planetary gear unit 7 releases the planetary carrier 73, resulting in no power input to the first end of the drum 52. The main motor drive unit 2 drives the vertical shaft 41 in the vertical shaft rotation device 4 to rotate. At the same time, the switching unit 3 keeps the auxiliary gear 62 in the motor auxiliary drive unit 6 meshing with the first internal gear ring 63 located at the second end of the drum 52. The motor auxiliary drive unit 6 drives the drum 52 in the hoisting device 5 to rotate, thereby lifting the drill rod to offset part of its weight, so that the actual drilling pressure reaches the preset value and decompression drilling is performed.

[0064] The automatic drilling method provided in this embodiment completely abandons the hydraulic cylinder pushing scheme when performing decompression drilling. Instead, it provides a continuous upward lifting force through the winch device 5. Since the effective stroke of the wire rope in the winch device 5 is extremely long, it completely eliminates the interruption of operation caused by stroke limitation, allowing the drill rod to rotate and be lowered continuously, thereby improving drilling efficiency.

[0065] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0066] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0067] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that they are in indirect contact through an intermediate medium. Furthermore, "above," "over," or "on top" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," or "beneath" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0068] In the description of this specification, the terms "one embodiment," "some embodiments," "embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0069] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make modifications, alterations, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. An electric drive vertical spindle drilling rig, comprising a base (1) and a main motor drive unit (2), a vertical spindle rotation device (4), and a hoisting device (5) integrated on the base (1), characterized in that, It also includes a motor auxiliary drive unit (6); The main motor drive unit (2) drives the vertical shaft (41) in the vertical shaft rotation device (4) to rotate or drives the drum (52) in the hoisting device (5) to rotate; When the drilling is started, the main motor drive unit (2) drives the drum (52) in the winch device (5) to rotate in the first direction; When drilling, the main motor drive unit (2) drives the drum (52) in the hoisting device (5) to rotate in the second direction; When pressure-reducing drilling is performed, the main motor drive unit (2) drives the vertical shaft (41) in the vertical shaft rotation device (4) to rotate, and the motor auxiliary drive unit (6) drives the drum (52) in the hoisting device (5) to rotate, so as to lift the drill rod in the vertical shaft (41) to offset part of its weight, thereby making the actual drilling pressure of the drill rod on the formation reach the preset value.

2. The electric drive vertical spindle drilling rig as described in claim 1, characterized in that: A steel wire rope is wound on the drum (52), and one end of the steel wire rope is connected to the drill rod through a power water tap to drive the drill rod to rise and fall.

3. The electrically driven vertical spindle drilling rig as described in claim 1, characterized in that: It also includes a hydraulic unit (8); The hydraulic unit (8) is used to drive the chuck (42) in the vertical shaft rotation device (4) to clamp or release the drill rod in the vertical shaft (41).

4. The electrically driven vertical shaft drilling rig as described in claim 1, characterized in that: The hoisting device (5) includes a braking unit (54); The braking unit (54) is used to brake the drum (52) in the hoisting device (5).

5. The electrically driven vertical spindle drilling rig as described in claim 4, characterized in that: The hoisting device (5) also includes an input shaft (51), the drum (52) and two support seats (53). The drum (52) is sleeved on the input shaft (51) and rotates relative to the input shaft (51). The input shaft (51) is connected to the first end of the drum (52) through the planetary gear unit (7), and the two ends of the input shaft (51) are rotatably mounted on the base (1) through the two support seats (53). The motor auxiliary drive unit (6) includes an auxiliary motor (61), an auxiliary gear (62) disposed at the output end of the auxiliary motor (61), and a first internal gear ring (63) disposed in the second end of the drum (52). The auxiliary gear (62) and the first internal gear ring (63) can be selectively meshed. When pressure relief drilling is performed, the auxiliary motor (61) drives the auxiliary gear (62) to rotate so that the first internal gear ring (63) drives the drum (52) to rotate in the first direction.

6. The electrically driven vertical spindle drilling rig as described in claim 5, characterized in that: It also includes a switching unit (3); The switching unit (3) includes a shift fork (31), a bearing (32), and a telescopic drive (33). The inner ring of the bearing (32) is fitted onto the connecting part of the auxiliary gear (62), the auxiliary gear (62) is fitted onto the output end of the auxiliary motor (61), and the auxiliary gear (62) can move along the axis of the output end of the auxiliary motor (61). The shift fork (31) is connected to the outer ring of the bearing (32); The fixed end of the telescopic drive member (33) is connected to the support base (53), and the moving end of the telescopic drive member (33) is connected to one end of the fork (31). The telescopic drive (33) drives the auxiliary gear (62) to move along the axis of the output end of the auxiliary motor (61) through the shift fork (31), so that the auxiliary gear (62) meshes with or disengages from the first internal gear ring (63).

7. The electrically driven vertical spindle drilling rig as described in claim 5, characterized in that: The planetary gear unit (7) includes a sun gear (71), a second internal gear ring (72), a planet carrier (73), and a plurality of planetary gears (74), wherein the plurality of planetary gears (74) are connected to one side of the planet carrier (73); The sun gear (71) is sleeved on the input shaft (51), and the second internal gear ring (72) is disposed at the first end of the drum (52). The sun gear (71) meshes with a plurality of planetary gears (74), and the plurality of planetary gears (74) drive the second internal gear ring (72) to rotate.

8. The electrically driven vertical spindle drilling rig as described in claim 7, characterized in that: The planetary gear unit (7) also includes a lifting clamp (75); The lifting clamp (75) is opposite to the outer edge of the planet carrier (73) and is used to clamp or release the planet carrier (73).

9. The electrically driven vertical spindle drilling rig as described in claim 5, characterized in that: The auxiliary motor (61) is a 5.5KW variable frequency motor.

10. An automatic drill bit feeding method, characterized in that: The electric drive vertical spindle drilling rig according to any one of claims 1-9 is used to feed the drill bit through the following steps; S1. The main motor drive unit (2) drives the drum (52) in the hoisting device (5) to rotate in the first direction to drive the drill rod to start drilling; S2, the hoisting device (5) stops the drum (52) from rotating; S3. The main motor drive unit (2) drives the drum (52) in the hoisting device (5) to rotate in the second direction to drive the drill rod to drill down; S4. The hoisting device (5) stops the drum (52) from rotating; S5. The main motor drive unit (2) drives the vertical shaft (41) in the vertical shaft rotation device (4) to rotate. At the same time, the motor auxiliary drive unit (6) drives the drum (52) in the hoisting device (5) to rotate, so as to offset part of the weight of the drill rod by lifting it, so that the actual drilling pressure reaches the preset value and pressure reduction drilling is carried out.

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