Pneumatic handheld drilling machine

Abstract

The utility model discloses a pneumatic type handheld drilling machine which comprises a separating drill rod arranged at the end of an extending drill rod and fixedly connected with the extending drill rod in a detachable mode. The plugging drill rod is arranged at the end part of the separating drill rod and is detachably and fixedly connected with the separating drill rod; the detection assembly is arranged in the plugging drill rod and / or the drill bit and used for detecting whether underground water and / or methane exists at the drill bit or not; and the separation assembly is arranged between the plugging drill rod and the separation drill rod and used for separating the extension drill rod from the plugging drill rod when underground water or methane is detected, and the plugging drill rod is reserved in the drill hole to plug the drill hole. The pneumatic handheld drilling machine is reasonable in design, can detect the condition of underground water at the drill bit in time, avoids too high experience requirements on workers, and guarantees the personal safety of the workers.

Description

Technical Field

[0001] This utility model relates to the field of pneumatic handheld drill technology, and in particular to a pneumatic handheld drill. Background Technology

[0002] Floods are a common type of accident in coal mining. These accidents are sudden and can cause serious damage to mines. Floods can cause devastating disasters to mines in a very short time. In some production mines, there are often many small, old, water-filled caverns, faults, and water-rich layers.

[0003] In existing technologies, the following methods are commonly used to determine if groundwater has been encountered during drilling: 1. Changes in drilling rig sound: When the drill bit contacts the aquifer, the drilling rig will become noticeably quieter or produce the sound of flowing water due to reduced resistance; 2. Sudden increase in drilling speed: When drilling reaches the aquifer, the rock layer becomes softer, and the drilling speed will suddenly increase, possibly accompanied by water leakage.

[0004] Both of the above methods require workers to have sufficient experience and judgment, which places high demands on drilling workers. If the workers fail to determine that they have drilled into groundwater, groundwater may gush out of the borehole when the drill rod is withdrawn, which may affect the safety of the surrounding workers.

[0005] Methane detection requires the drill pipe to be removed from the borehole and the gas to diffuse into the roadway before it can be detected by a methane detector, which poses a significant threat to the physical and mental safety of workers.

[0006] Therefore, it is necessary to improve the existing pneumatic hand-held drilling rigs. Utility Model Content

[0007] The purpose of this invention is to overcome the defects in the existing technology and provide a pneumatic handheld drill that can detect the groundwater and methane levels at the drill bit in a timely manner, avoiding excessive requirements on the worker's experience and ensuring the worker's safety.

[0008] To solve the above-mentioned technical problems, this utility model provides a pneumatic handheld drill, comprising: a frame; a drill body connected to the frame; several extension drill rods, which are sequentially and detachably fixedly connected to each other and to the rotating shaft of the drill body; a detachable drill rod, disposed at the end of the extension drill rod and detachably fixedly connected to the extension drill rod; a sealing drill rod, disposed at the end of the detachable drill rod and detachably fixedly connected to the detachable drill rod; a drill bit, disposed at the end of the sealing drill rod and detachably fixedly connected to the sealing drill rod; a detection component, disposed within the sealing drill rod and / or the drill bit, for detecting the presence of groundwater and / or methane at the drill bit; and a separation component, disposed between the sealing drill rod and the detachable drill rod, for separating the extension drill rod from the sealing drill rod and leaving the sealing drill rod inside the borehole to seal the borehole when groundwater or methane is detected.

[0009] According to one embodiment of the present invention, the sealing drill rod is provided with an installation cavity, and the installation cavity and the outer wall of the sealing drill rod are provided with a detection channel; the detection component includes a detection end disposed in the installation cavity, and the detection end includes a water immersion sensor and a methane sensor.

[0010] According to one embodiment of the present invention, the sealing drill rod is provided with a female connector, and the disengaging drill rod is provided with a male connector that is inserted and engaged with the female connector; the separation assembly includes a limiting pin movably connected to the male connector and a limiting hole provided on the side wall of the female connector, the limiting pin and the limiting hole being in a limiting engagement; the limiting pin has two working positions: a first working position in which the limiting pin is disposed in the limiting hole; and a second working position in which the limiting pin is separated from the limiting hole.

[0011] According to one embodiment of the present invention, the separation component includes a pull-away component for separating the limiting pin from the limiting hole, and the separation component further includes an elastic element for pressing the limiting pin against the limiting hole in its natural state.

[0012] According to one embodiment of the present invention, the pull-away assembly includes a pin seat, the release drill rod is provided with a groove, the extension direction of the groove is parallel to the axis of the release drill rod, and the pin seat is slidably connected to the groove; in a first working position, the pin seat is adjacent to one end of the groove; in a second working position, the pin seat is adjacent to the other end of the groove.

[0013] According to one embodiment of the present invention, the pin seat is provided with an inclined groove, the inclined groove is inclined and its inclined direction is towards the sealing drill rod, and the limiting pin is slidably connected to the inclined groove; in the first working position, the sliding end of the limiting pin is adjacent to the groove opening of the inclined groove; in the second working position, the sliding end of the limiting pin is adjacent to the bottom of the inclined groove.

[0014] According to one embodiment of the present invention, the limiting pin is provided with a guide groove, the extension direction of the guide groove is perpendicular to the axial direction of the limiting groove, a compression spring seat is slidably disposed in the guide groove, and the elastic element is clamped between the compression spring seat and the bottom of the inclined groove.

[0015] According to one embodiment of the present invention, the detached drill rod is provided with a blind hole, and in the second working position, the limiting pin is limited and engaged with the blind hole.

[0016] According to one embodiment of the present invention, a push-pull rod is provided at the end of the pin seat, and the push-pull rod passes through the detachable drill rod; it also includes an extension rod, and a plurality of extension rods are sequentially and detachably fixedly connected end to end, the extension rods are detachably fixedly connected to the push-pull rods, and the extension rods pass through the extension drill rods.

[0017] According to one embodiment of the present invention, the two ends of the extension drill rod are provided with a first female opening and a first male opening. The side wall of the first female opening is provided with a first insertion hole, and the side wall of the first male opening is provided with a first elastic pin. The first elastic pins of two adjacent extension drill rods are matched with the first insertion hole for limiting engagement.

[0018] According to one embodiment of the present invention, the two ends of the extension rod are provided with a second female opening and a second male opening, the side wall of the second female opening is provided with a second insertion hole, the side wall of the second male opening is provided with a second elastic pin, and the second elastic pins of two adjacent extension rods are mutually limiting and engaged with the second insertion hole.

[0019] According to one embodiment of the present invention, the second elastic pin is arranged coaxially with the first insertion hole.

[0020] According to one embodiment of the present invention, the extension drill rod is provided with a through hole, and the extension rod passes through the through hole.

[0021] Compared with existing technologies, the pneumatic handheld drill of this invention has a reasonable structural design. When the detection component at the drill bit or the sealing drill rod detects groundwater or methane, the drilling operation can be stopped in time. The separation component separates the detached drill rod from the sealing drill rod, and the sealing drill rod remains in the borehole to seal it for subsequent safety treatment. This avoids the phenomenon of groundwater seepage or methane leakage, improves the safety of drilling, and protects the personal safety of workers. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the pneumatic handheld drill of this utility model;

[0023] Figure 2 It is a schematic diagram of the structure connecting the extended drill pipe, the detached drill pipe, the plugged drill pipe, and the drill bit.

[0024] Figure 3 yes Figure 2 An explosion diagram;

[0025] Figure 4 This is a schematic diagram of the structure connecting the separation component to the detached drill pipe;

[0026] Figure 5 yes Figure 4 An explosion diagram;

[0027] Figure 6 yes Figure 4 A sectional view (first working position);

[0028] Figure 7 It is a cross-sectional view detached from the drill pipe;

[0029] Figure 8 This is a schematic diagram of the structure of the separate components;

[0030] Figure 9 yes Figure 8 A sectional view;

[0031] Figure 10 yes Figure 8 An explosion diagram;

[0032] Figure 11 yes Figure 10 A sectional view;

[0033] Figure 12 This is a cross-sectional view of the separated components (second working position);

[0034] Figure 13 This is a schematic diagram of the limit pin structure;

[0035] Figure 14 This is a schematic diagram of the compression spring seat;

[0036] Figure 15 This is a schematic diagram of the extended drill pipe structure;

[0037] Figure 16 yes Figure 15 A sectional view;

[0038] Figure 17 This is a structural schematic diagram of the extension rod;

[0039] Figure 18 yes Figure 17 A sectional view;

[0040] Figure 19 This is a schematic diagram of the plugging drill pipe structure;

[0041] Figure 20 yes Figure 19 A sectional view;

[0042] Figure 21 This is a schematic diagram of the drill bit's structure;

[0043] Figure 22 This is a structural schematic diagram of the drilling rig body;

[0044] Figure 23 This is a schematic diagram of the internal structure of the pin seat;

[0045] Figure 24 This is a schematic diagram of the state of the separation component during the switching process from the first working position to the second working position;

[0046] Figure 25 This is a schematic diagram showing the state of the separation component in the second working position;

[0047] In the diagram: 100, Frame; 200, Drill Rig Body; 210, Rotary Shaft; 220, Receiving Hole; 300, Extension Drill Rod; 310, First Female Port; 311, First Insertion Hole; 320, First Male Connector; 321, First Elastic Pin; 330, Through Hole; 400, Disengagement Drill Rod; 410, Insertion Male Connector; 420, Slide Groove; 421, Blind Hole; 430, Elastic Pressing Block; 500, Sealing Drill Rod; 510, Mounting Cavity; 52 0. Detection channel; 530. Plug-in female port; 531. Limiting hole; 600. Drill bit; 700. Detection end; 800. Separation assembly; 810. Limiting pin; 811. Guide groove; 812. Compression spring seat; 820. Elastic element; 830. Pin seat; 831. Inclined groove; 832. Push-pull rod; 840. Extension rod; 841. Second female port; 842. Second male port; 843. Second insertion hole; 844. Second elastic pin. Detailed Implementation

[0048] The specific embodiments of this utility model will be further described below with reference to the accompanying drawings and examples. The following examples are only used to more clearly illustrate the technical solution of this utility model and should not be construed as limiting the scope of protection of this utility model.

[0049] like Figure 1-25 As shown, the pneumatic handheld drill of this utility model includes: a frame 100; a drill body 200 connected to the frame 100; several extension drill rods 300, which are sequentially and detachably fixedly connected to each other, and are detachably fixedly connected to the rotating shaft 210 of the drill body 200; a detachable drill rod 400, which is located at the end of the extension drill rods 300 and is detachably fixedly connected to the extension drill rods 300; and a sealing drill rod 500, which is located at the end of the detachable drill rods 400 and is detachably fixedly connected to the detachable drill rods 400. The system includes: a drill bit 600, disposed at the end of the plugging drill rod 500 and detachably fixed to the plugging drill rod 500; a detection component, disposed within the plugging drill rod 500 and / or the drill bit 600, for detecting the presence of groundwater and / or methane at the drill bit 600; and a separation component 800, disposed between the plugging drill rod 500 and the detachment drill rod 400, for separating the extension drill rod 300 from the plugging drill rod 500 and leaving the plugging drill rod 500 inside the borehole to seal the borehole when groundwater or methane is detected.

[0050] With this design, a detection component is installed at the drill bit 600 or the plugging drill rod 500 to monitor in real time whether groundwater or methane will appear during drilling. If the detection component detects an abnormality, the drilling operation is stopped immediately. The separation component 800 separates the detachment drill rod 400 from the plugging drill rod 500. The detachment drill rod 400 and the extension drill rod 300 are removed from the borehole, while the plugging drill rod 500 remains in the borehole to seal it and prevent groundwater or methane from overflowing, which will be handled safely later.

[0051] According to one embodiment of the present invention, the plugging drill rod 500 is provided with an installation cavity 510, and the installation cavity 510 and the outer wall of the plugging drill rod 500 are provided with a detection channel 520; the detection component includes a detection end 700 disposed in the installation cavity 510, and the detection end 700 includes a water immersion sensor and a methane sensor.

[0052] With this design, the detection end 700 is set inside the plugging drill rod 500, which can provide a certain degree of protection for the detection component during drilling operations; the water immersion sensor can be the Lingpu RS1 water immersion sensor; the methane sensor can be the infrared methane sensor GW-3000B.

[0053] According to one embodiment of the present invention, the plugging drill rod 500 is provided with a female connector 530, and the disengaging drill rod 400 is provided with a male connector 410 that is plugged into the female connector 530; the separation assembly 800 includes a limiting pin 810 movably connected to the male connector 410 and a limiting hole 531 provided on the side wall of the female connector 530, wherein the limiting pin 810 and the limiting hole 531 are mutually limitingly engaged; the limiting pin 810 has two working positions: a first working position in which the limiting pin 810 is disposed in the limiting hole 531; and a second working position in which the limiting pin 810 is separated from the limiting hole 531.

[0054] With this design, during normal drilling operations and when installing the detachable drill rod 400, the limiting pin 810 is in the first working position; when groundwater or methane is detected, the detachable drill rod 400 needs to be separated from the plugging drill rod 500. At this time, the limiting pin 810 is in the second working position, and there is no axial limitation between the detachable drill rod 400 and the plugging drill rod 500, so the detachable drill rod 400 can be separated from the plugging drill rod 500.

[0055] According to one embodiment of the present invention, the separation component 800 includes a pull-away component for separating the limiting pin 810 from the limiting hole 531, and the separation component 800 also includes an elastic member 820 for pressing the limiting pin 810 against the limiting hole 531 in its natural state.

[0056] This design enables the limit pin 810 to switch between the first working position and the second working position.

[0057] According to one embodiment of the present invention, the pull-away assembly includes a pin seat 830, and the release drill rod 400 is provided with a groove 420. The extension direction of the groove 420 is parallel to the axis of the release drill rod 400, and the pin seat 830 is slidably connected to the groove 420. In a first working position, the pin seat 830 and one end of the groove 420 are adjacent to each other. In a second working position, the pin seat 830 and the other end of the groove 420 are adjacent to each other.

[0058] With this design, the position of the limit pin 810 can be switched by adjusting the position of the pin seat 830.

[0059] According to one embodiment of the present invention, the pin seat 830 is provided with an inclined groove 831, the inclined groove 831 is inclined and its inclined direction is towards the sealing drill rod 500, and the limiting pin 810 is slidably connected to the inclined groove 831; in the first working position, the sliding end of the limiting pin 810 is adjacent to the groove opening of the inclined groove 831; in the second working position, the sliding end of the limiting pin 810 is adjacent to the bottom of the inclined groove 831.

[0060] With this design, the limiting pin 810 can extend or retract within the pin seat 830, and the inclined groove 831 guides the limiting pin 810.

[0061] According to one embodiment of the present invention, the limiting pin 810 is provided with a guide groove 811, the extension direction of the guide groove 811 is perpendicular to the axial direction of the limiting groove, a compression spring seat 812 is slidably disposed in the guide groove 811, and the elastic member 820 is sandwiched between the compression spring seat 812 and the bottom of the inclined groove 831.

[0062] With this design, the limiting pin 810 can ensure that the elastic element 820 is always in a vertical state during the sliding process, thus avoiding the phenomenon of the elastic element 820 being tilted; the elastic element 820 can be a compression spring, etc.

[0063] According to one embodiment of the present invention, the detached drill rod 400 is provided with a blind hole 421, and in the second working position, the limiting pin 810 is limited and engaged with the blind hole 421.

[0064] With this design, the limiting pin 810 is confined in the blind hole 421, preventing the pin seat 830 from moving during the separation of the detached drill rod 400 from the sealing drill rod 500.

[0065] According to one embodiment of this utility model, an elastic pressing block 430 is provided between the blind hole 421 and the side wall of the detached drill rod 400. When the limiting pin 810 is positioned in the blind hole 421 and the detached drill rod 400 is pulled out, if the limiting pin 810 needs to be reset to the first working position, the elastic pressing block 430 can be used to press the limiting pin 810, causing the limiting pin 810 to disengage from the blind hole 421. At this time, pushing the pin seat 830 can move the limiting pin 810 to the first working position. The setting of the elastic pressing block 430 can also prevent mud and other substances from entering the blind hole 421.

[0066] According to one embodiment of the present invention, a push-pull rod 832 is provided at the end of the pin seat 830, and the push-pull rod 832 passes through the detachable drill rod 400; it also includes an extension rod 840, a plurality of extension rods 840 being sequentially and detachably fixedly connected end to end, the extension rod 840 being detachably fixedly connected to the push-pull rod 832, and the extension rod 840 passing through the extension drill rod 300.

[0067] The drilling rig body 200 drives the sealing drill rod 500 and the drill bit 600 to drill a hole. As the drilling gradually goes deeper, the disengagement drill rod 400 is connected to the end of the sealing drill rod 500 in sequence, and the extension drill rod 300 is connected to the end of the disengagement drill rod 400 in sequence. Several extension drill rods 300 are connected in sequence. Before the extension drill rods 300 are connected, the extension rod 840 needs to be connected to the push-pull rod 832. Then the extension drill rod 300 is sleeved on the extension rod 840.

[0068] According to one embodiment of the present invention, the two ends of the extension drill rod 300 are provided with a first female opening 310 and a first male opening 320. The side wall of the first female opening 310 is provided with a first insertion hole 311, and the side wall of the first male opening 320 is provided with a first elastic pin 321. The first elastic pins 321 of two adjacent extension drill rods 300 are mutually limiting and cooperating with the first insertion holes 311.

[0069] This design achieves the goal of sequentially disassembling and fixing the extension drill pipe 300.

[0070] According to one embodiment of the present invention, the two ends of the extension rod 840 are provided with a second female port 841 and a second male port 842. The side wall of the second female port 841 is provided with a second insertion hole 843, and the side wall of the second male port 842 is provided with a second elastic pin 844. The second elastic pins 844 of two adjacent extension rods 840 are mutually limiting and cooperating with the second insertion hole 843.

[0071] This design achieves the purpose of sequentially detachable and fixed connection of the extension rods 840.

[0072] According to one embodiment of the present invention, the second elastic pin 844 is arranged coaxially with the first insertion hole 311.

[0073] With this design, when it is necessary to disassemble the extension rod 840, a long, hard object such as a screwdriver can be used to insert it into the first insertion hole 311 and apply force to the second elastic pin 844 to compress the second elastic pin 844. The second elastic pin 844 will then separate from the second insertion hole 843, at which point the extension rod 840 can be pulled out.

[0074] According to one embodiment of the present invention, the extension drill rod 300 is provided with a through hole 330, and the extension rod 840 passes through the through hole 330.

[0075] According to one embodiment of the present invention, the rotating shaft 210 of the drilling rig body 200 is provided with a receiving hole 220 for accommodating the extension rod 840.

[0076] This utility model also provides a method for using a pneumatic handheld drill, including the following steps:

[0077] S100, Fix the frame 100 tightly against the side wall of the roadway;

[0078] S200, the drilling rig body 200 is fixed on the frame 100;

[0079] S300, drill bit 600 and plugging drill rod 500 are fixedly connected, and then the drilling rig body 200 is started to drill holes in the side wall of the tunnel.

[0080] S400. As drilling continues to deepen, the plugging drill rod 500 is separated from the drilling machine body 200. The detachment drill rod 400 is connected to the end of the plugging drill rod 500 to continue drilling. The detachment drill rod 400 is connected to the drilling machine body 200.

[0081] S500. As drilling continues to deepen, the detachment drill rod 400 separates from the drill body 200. The extension rod 840 is inserted and connected to the push-pull rod 832. The extension drill rod 300 is sleeved on the extension rod 840. The extension drill rod 300 is connected to the end of the detachment drill rod 400. The extension drill rod 300 is connected to the drill body 200 to continue drilling.

[0082] S600. As drilling continues, extension rods 840 and extension drill rods 300 are continuously connected. Extension rods 840 are fixed by inserting the second insertion hole 843 into the second elastic pin 844. Extension drill rods 300 are fixed by inserting the first insertion hole 311 into the first elastic pin 321.

[0083] S700 When the detection terminal 700 detects groundwater or methane, and the signal receiving terminal located outside the borehole receives the signal sent by the detection terminal 700, the drilling operation is stopped.

[0084] S800: Separate the detachable drill rod 400 from the plugging drill rod 500. The plugging drill rod 500 remains in the borehole to perform a plugging function.

[0085] S800 includes the following steps

[0086] S810, the extension drill pipe 300 is separated from the drilling rig body 200;

[0087] S820, pull the extension rod 840 towards the drilling rig body 200, the extension rod 840 drives the push-pull rod 832 to slide, and the push-pull rod 832 drives the pin seat 830 to slide in the slide groove 420;

[0088] Under the axial guidance of the limiting hole 531 and the axial guidance of the sliding end of the limiting pin 810, the limiting pin 810 slides axially relative to the limiting hole 531 and slides obliquely relative to the pin seat 830. The elastic element 820 is compressed, and the compression spring seat 812 slides with the limiting pin 810 to ensure that the elastic element 820 is always vertical. The compression spring seat 812 and the pin seat 830 are relatively fixed.

[0089] S840 When the limiting end of the limiting pin 810 separates from the limiting hole 531, the elastic element 820 is compressed to the extreme. As the pin seat 830 continues to slide, the limiting end of the limiting pin 810 abuts against the inner wall of the insertion female 530, and then abuts against the inner wall of the disengaged drill rod 400.

[0090] S850. When the pin seat 830 abuts against the end of the slide groove 420, the limiting pin 810 is coaxial with the blind hole 421, and the force applied to the extension rod 840 stops. Under the elastic force of the elastic element 820, the limiting pin 810 is inserted into the blind hole 421. At this time, there is no axial limitation between the disengaged drill rod 400 and the plugging drill rod 500.

[0091] S860, the extension drill rod 300 is connected to the rotating shaft 210 of the drilling machine body 200. Rotating the rotating shaft 210 in the opposite direction will drive the extension drill rod 300 and the detachment drill rod 400 to reverse and exit the borehole. The sealing drill rod 500 will remain in the borehole to play a sealing role.

[0092] In another specific embodiment, the sensor can use wires instead of wireless signal transmission. The wires cooperate with the extension drill rods 300 in sections, and the signal is transmitted from deep in the borehole to a location adjacent to the drilling rig body through wire insertion, so that the receiving end outside the borehole can receive the signal.

[0093] In another specific embodiment, an electrical transmission wire is provided in the extension rod 840, and the extension rod 840 can serve as a carrier for electrical signal transmission.

[0094] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A pneumatic hand-held drill, characterized in that The utility model relates to a drilling machine, including: A frame (100); A drilling machine body (200) is connected with the frame (100); An extension drill rod (300) is provided with a plurality of and is fixedly connected in sequence, and is fixedly connected with the rotating shaft of the drilling machine body (200); A separation drill rod (400) is arranged at the end of the extension drill rod (300) and is fixedly connected with the extension drill rod (300); A blocking drill rod (500) is arranged at the end of the separation drill rod (400) and is fixedly connected with the separation drill rod (400); A drill bit (600) is arranged at the end of the blocking drill rod (500) and is fixedly connected with the blocking drill rod (500); A detection assembly is arranged in the blocking drill rod (500) and / or drill bit (600) and is used for detecting whether underground water and / or methane exist at the drill bit (600); A separation assembly (800) is arranged between the blocking drill rod (500) and the separation drill rod (400) and is used for separating the extension drill rod (300) from the blocking drill rod (500) when detecting underground water or methane, and blocking the drill hole by storing the blocking drill rod (500) in the drill hole.

2. A pneumatic hand-held drill as claimed in claim 1, characterized in that The blocking drill rod (500) is provided with a mounting cavity (510), and the mounting cavity (510) and the outer wall of the blocking drill rod (500) are provided with a communication detection channel (520); the detection assembly includes a detection end (700) arranged in the mounting cavity (510), and the detection end (700) includes a water immersion sensor and a methane sensor.

3. The pneumatic hand-held drill as claimed in claim 1, characterized in that The blocking drill rod (500) is provided with a plug-in female mouth (530), the separation drill rod (400) is provided with a plug-in male head (410) matched with the plug-in female mouth (530); the separation assembly (800) includes a limiting pin (810) movably connected with the plug-in male head (410), a limiting hole (531) arranged on the side wall of the plug-in female mouth (530), and the limiting pin (810) is limitedly matched with the limiting hole (531); the limiting pin (810) has two working positions, a first working position: the limiting pin (810) is arranged in the limiting hole (531); A second working position, the limiting pin (810) is separated from the limiting hole (531).

4. The pneumatic hand-held drill according to claim 3, characterized in that The separation assembly (800) includes a pull-off assembly for separating the limiting pin (810) from the limiting hole (531), and the separation assembly (800) further includes an elastic member (820) for abutting the limiting pin (810) in the limiting hole (531) in a natural state.

5. A pneumatic hand-held drill as claimed in claim 4, characterized in that The pulling-off assembly comprises a pin shaft seat (830), the pulling-off drill rod (400) is provided with a sliding groove (420), the extending direction of the sliding groove (420) is parallel to the axial direction of the pulling-off drill rod (400), and the pin shaft seat (830) is in sliding connection with the sliding groove (420); in the first working position, the pin shaft seat (830) is arranged adjacent to one end of the sliding groove (420); and in the second working position, the pin shaft seat (830) is arranged adjacent to the other end of the sliding groove (420).

6. A pneumatic hand-held drill as claimed in claim 5, characterized in that The pin shaft seat (830) is provided with an inclined groove (831), the inclined groove (831) is arranged in an inclined manner, and the inclined direction of the inclined groove (831) is towards the plugging drill rod (500), the limiting pin (810) is in sliding connection with the inclined groove (831); in the first working position, the sliding end of the limiting pin (810) is arranged adjacent to the groove mouth of the inclined groove (831); and in the second working position, the sliding end of the limiting pin (810) is arranged adjacent to the groove bottom of the inclined groove (831).

7. A pneumatic hand-held drill as claimed in claim 6, characterized in that The limiting pin (810) is provided with a guide groove (811), the extending direction of the guide groove (811) is perpendicular to the axial direction of the limiting groove, a compression spring seat (812) is slidably arranged in the guide groove (811), and the elastic member (820) is clamped between the compression spring seat (812) and the groove bottom of the inclined groove (831).

8. A pneumatic hand-held drill as claimed in claim 7, characterized in that The pulling-off drill rod (400) is provided with a blind hole (421), and in the second working position, the limiting pin (810) is in limiting cooperation with the blind hole (421).

9. A pneumatic hand-held drill as claimed in claim 8, characterized in that The end of the pin shaft seat (830) is provided with a push-pull rod (832), the push-pull rod (832) is arranged in the pulling-off drill rod (400); further comprising an extension rod (840), a plurality of extension rods (840) are sequentially and detachably fixedly connected, the extension rod (840) is detachably fixedly connected with the push-pull rod (832), and the extension rod (840) is arranged in the extension drill rod (300).

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