Drilling depth measuring device for drilling and blasting construction
By designing a disc-shaped main body and probe structure in the borehole depth measuring device, the infrared rangefinder is ensured to be coaxial with the borehole, thus solving the problem of inaccurate borehole measurement in soft surrounding rock environments and achieving more accurate depth measurement.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- POWERCHINA WATER ENVIRONMENT GOVERANCE
- Filing Date
- 2025-05-29
- Publication Date
- 2026-04-21
AI Technical Summary
In weak surrounding rock environments, boreholes may experience localized collapses due to loose rock masses. Residual rock powder and gravel on the borehole walls can affect infrared radiation propagation, leading to inaccurate borehole depth measurements.
Design a borehole depth measuring device, which adopts a disc-shaped main body and multiple probes. The probes are positioned to abut against the inner wall of the borehole through a positioning structure, ensuring that the infrared rangefinder is coaxially set with the borehole and avoiding the interference of debris on the inner wall of the borehole with the infrared light propagation.
This method ensures that the infrared propagation trajectory coincides with the borehole centerline, avoiding the influence of local collapse of the borehole inner wall and debris, and ensuring the accuracy of borehole depth measurement.
Smart Images
Figure CN224149550U_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of borehole depth measurement technology, specifically relating to a borehole depth measurement device for drilling and blasting operations. Background Technology
[0002] Drill-and-blast excavation is a tunneling and underground engineering technique that uses drilling, charging, and blasting to excavate rock. It is widely used in the construction of mountain tunnels, fractured rock tunnels, and short tunnels. Its core process includes drilling, charging, plugging, detonation, and subsequent muck removal and support. It is characterized by its high flexibility, wide adaptability to geological conditions, and high excavation efficiency.
[0003] In existing technologies, the depth of the formed borehole needs to be measured after drilling to avoid adverse effects on the charging process caused by insufficient or excessive depth. A common measurement method is to use an infrared rangefinder to project infrared light onto the bottom of the borehole to determine the borehole depth.
[0004] The inventors discovered that in environments with weak surrounding rock (such as fractured rock strata), boreholes may experience local collapse due to loose rock mass, and a large amount of rock powder and gravel remain on the borehole wall, which can easily affect the propagation of infrared rays and affect the reliability of measurement results. Utility Model Content
[0005] This application provides a borehole depth measuring device for drilling and blasting operations, which aims to make the propagation trajectory of infrared rays coincide with the central axis of the borehole, avoid the influence of local collapse of the borehole inner wall, rock powder and gravel, and ensure the accuracy of the borehole depth measurement results.
[0006] To achieve the above objectives, the technical solution adopted in this application is as follows:
[0007] A drilling depth measuring device for drilling and blasting operations is provided, comprising:
[0008] The main body adopts a disc-shaped structure and is used to fit onto the construction surface and cover the drill holes;
[0009] At least three probes are disposed on the main body and arranged at intervals along the circumference of the main body to be suitable for insertion into the borehole; each probe is slidably connected to the main body and is adapted to move toward or away from the central axis of the main body so that each probe abuts against the inner wall of the borehole;
[0010] A positioning structure, disposed on the main body and connected to each of the probe rods, restricts the movement of the probe rods relative to the main body; and
[0011] The first infrared rangefinder body is fixedly installed at the center of the main body, so that when each probe abuts against the inner wall of the borehole, the first infrared rangefinder body and the borehole are coaxially arranged.
[0012] In one possible implementation, the body has a plurality of guide holes corresponding one-to-one with the plurality of probes; the plurality of guide holes are arranged at circumferential intervals along the body, and each guide hole extends radially along the body;
[0013] The probe rod is inserted into the corresponding guide hole and has the freedom to move along the length of the guide hole.
[0014] In one possible implementation, the positioning structure includes:
[0015] A docking shell, coaxially mounted on the main body, has pre-drilled holes suitable for the probe rod to pass through and for avoiding the probe rod's movement trajectory; and
[0016] A turntable is coaxially mounted on the main body and positioned between the docking shell and the main body; the turntable is driven by a rotating motor for rotating it, and the rotating motor is fixedly connected to the docking shell.
[0017] The turntable has multiple beam positioning holes that correspond one-to-one with the multiple guide holes; each beam positioning hole extends radially outward in an arc shape along the turntable, so that when the turntable rotates relative to the main body, the connection position between the beam positioning hole and the guide hole moves radially along the main body.
[0018] In one possible implementation, a second infrared rangefinder body is fixedly mounted on the docking shell;
[0019] When the probe abuts against the bottom of the borehole, the second infrared rangefinder body can measure the distance between the docking shell and the construction surface.
[0020] In one possible implementation, a recessed groove is provided on the docking shell, and the second infrared rangefinder body is fixedly embedded in the recessed groove;
[0021] A baffle is fitted into the opening of the sinking trough, and the baffle has a light-transmitting port suitable for the infrared rays of the second infrared rangefinder body to pass through.
[0022] In one possible implementation, the docking shell has a mounting frame on the side facing away from the main body, and the rotating motor is fixedly embedded in the mounting frame; the mounting frame has a mounting plate detachably connected to the side facing away from the docking shell, the mounting plate is adapted to abut against the rotating motor, and the first infrared rangefinder body is fixedly mounted on the mounting plate.
[0023] In one possible implementation, the mounting frame has a first protrusion, and the mounting plate has a second protrusion adapted to overlap with the first protrusion; the first protrusion has a first through hole, and the second protrusion has a second through hole adapted to coaxially communicate with the first through hole; the mounting plate further includes:
[0024] A locking bolt, adapted to be inserted into the interconnected first and second through holes, with its head abutting against the first or second protrusion; and
[0025] A stop nut, threadedly connected to the locking bolt, is adapted to abut against the second protrusion or the first protrusion to cooperate with the head of the locking bolt and restrict the movement of the mounting plate away from the mounting frame.
[0026] In one possible implementation, the end of the probe extends from the guide hole, and its extended end has an enlarged diameter portion extending radially outward, and the side of the probe extending outward has a limiting member connected to the main body for abutting the enlarged diameter portion.
[0027] In one possible implementation, a handle is fixedly provided on the main body;
[0028] When the main body is in contact with the construction surface, the handle is located on the side of the main body facing away from the construction surface, for the operator to hold.
[0029] In one possible implementation, each of the probes is fitted with a rubber sleeve.
[0030] In this embodiment, by moving the main body to a position that fits against the construction surface and blocks the borehole, the probe rod can be inserted into the borehole. At this time, by adjusting the positioning structure, each probe rod can be moved synchronously away from the central axis of the borehole until each probe rod abuts against the inner wall of the borehole, achieving the technical objective of coaxially setting the first infrared rangefinder body and the borehole. Based on the coaxial setting of the first infrared rangefinder body and the borehole, opening the first infrared rangefinder body can form an infrared trajectory that coincides with the central axis of the borehole, avoiding the influence of protruding debris on the inner wall of the borehole on the infrared propagation.
[0031] The borehole depth measuring device for drilling and blasting operations provided in this embodiment, compared with the prior art, can make the propagation trajectory of infrared rays coincide with the central axis of the borehole, avoiding the influence of local collapse of the borehole inner wall, rock powder and gravel, and ensuring the accuracy of the borehole depth measurement results. Attached Figure Description
[0032] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0033] Figure 1 One of the three-dimensional structural schematic diagrams of the drilling depth measuring device for drilling and blasting operations provided in the embodiments of this application;
[0034] Figure 2 A second three-dimensional structural schematic diagram of the borehole depth measuring device for drilling and blasting operations provided in the embodiments of this application;
[0035] Figure 3 for Figure 2 A magnified view of a portion of the middle circle A;
[0036] Figure 4 This is a partially enlarged schematic diagram of the docking shell and the second infrared rangefinder body used in the embodiments of this application from an explosion perspective.
[0037] Figure 5 This is a three-dimensional structural diagram of the main body and limiting member used in the embodiments of this application from an exploded perspective;
[0038] Figure 6 This is a three-dimensional structural diagram of the probe and rubber sleeve used in the embodiments of this application from an explosion perspective;
[0039] Figure 7 This is a three-dimensional structural diagram of the docking shell and mounting frame used in the embodiments of this application in an assembled state;
[0040] Figure 8 This is an exploded view of the positioning structure used in the embodiments of this application;
[0041] Figure 9 This is a partially enlarged schematic diagram of the mounting frame and mounting plate used in the embodiments of this application from an exploded view.
[0042] Explanation of reference numerals in the attached drawings: 1. Main body; 11. Guide hole; 12. Limiting component; 13. Handle; 2. Probe rod; 21. Enlarged diameter section; 22. Rubber sleeve; 3. Positioning structure; 31. Docking shell; 311. Reserved hole; 312. Sinking groove; 32. Turntable; 321. Rotating motor; 322. Beam positioning hole; 4. First infrared rangefinder body; 5. Second infrared rangefinder body; 6. Baffle; 61. Light-transmitting opening; 7. Mounting frame; 71. First protrusion; 711. First through hole; 8. Mounting plate; 81. Second protrusion; 811. Second through hole; 9. Locking bolt; 91. Stop nut. Detailed Implementation
[0043] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.
[0044] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.
[0045] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.
[0046] Furthermore, 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 technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.
[0047] Please refer to the following: Figures 1 to 9 The drilling depth measuring device for drilling and blasting operations provided in this application will now be described. The drilling depth measuring device for drilling and blasting operations proposed in this application includes a main body 1, a probe 2, a positioning structure 3, and a first infrared rangefinder body 4.
[0048] The main body 1 adopts a disc-shaped structure and is used to adhere to the construction surface and cover the drilling holes. In this embodiment, for ease of description, the surface of the main body 1 that adheres to the construction surface is defined as its front side; correspondingly, the side of the main body 1 that faces away from the construction surface is its rear side.
[0049] The probe rods 2 are disposed on the front side of the main body 1, and there are at least three of them. In this embodiment, there are three probe rods 2, which are arranged at intervals along the circumference of the main body 1, so that each probe rod 2 can be inserted into the borehole when the main body 1 blocks the borehole. Furthermore, each probe rod 2 is slidably connected to the main body 1 and is adapted to move toward or away from the central axis of the main body 1, so that each probe rod 2 abuts against the inner wall of the borehole, thereby coinciding the central axis of the main body 1 and the central axis of the borehole.
[0050] The positioning structure 3 is mounted on the main body 1 and connected to each probe rod 2 to restrict the movement of the probe rod 2 relative to the main body 1. Based on this, the main body 1 can be used in at least two ways: First, the main body 1 is fixed to the construction surface, the probe rod 2 is inserted into the borehole, and then each probe rod 2 is moved synchronously by the positioning structure 3 so that each probe rod 2 moves away from the central axis of the main body 1 until it abuts the borehole; this is an accurate measurement method. Second, the positions of the main body 1 and the probe rod 2 are first fixed by the positioning structure 3 so that the distance between the probe rod 2 and the central axis of the main body 1 is approximately equal to the radius of the cross-sectional circle of the borehole; this allows the main body 1 to be directly applied to the measurement of this type of borehole (and also serves to check the borehole specifications); this is a rapid measurement method.
[0051] The first infrared rangefinder body 4 is fixedly installed at the center of the main body 1 so that when each probe rod 2 abuts against the inner wall of the borehole, the first infrared rangefinder body 4 and the borehole are coaxially arranged.
[0052] In this embodiment, by moving the main body 1 to a position that fits the construction surface and blocks the borehole, the probe rod 2 can be inserted into the borehole. At this time, by adjusting the positioning structure 3, each probe rod 2 can be moved synchronously away from the central axis of the borehole until each probe rod 2 abuts against the inner wall of the borehole, achieving the technical objective of coaxially setting the first infrared rangefinder body 4 and the borehole. Based on the coaxial setting of the first infrared rangefinder body 4 and the borehole, opening the first infrared rangefinder body 4 can form an infrared trajectory that coincides with the central axis of the borehole, avoiding the influence of protruding debris on the inner wall of the borehole on the infrared propagation.
[0053] The drilling depth measuring device for drilling and blasting operations provided in this embodiment, compared with the prior art, can take advantage of the characteristic that the protrusions on the borehole surface are unlikely to affect its center position, so that the propagation trajectory of infrared rays coincides with the central axis of the borehole, avoiding the influence of local collapse of the borehole inner wall, rock powder and gravel, and ensuring the accuracy of the borehole depth measurement results.
[0054] In some embodiments, such as Figure 1 and Figure 5 As shown, the main body 1 has multiple guide holes 11 corresponding to multiple probe rods 2; the multiple guide holes 11 are arranged at intervals along the circumference of the main body 1, and each guide hole 11 extends radially along the main body 1.
[0055] After actual assembly, each probe 2 is inserted into the corresponding guide hole 11 and has the freedom to move along the length direction of the guide hole 11 to realize the sliding connection between the probe 2 and the main body 1.
[0056] In some embodiments, such as Figure 2 and Figure 8 As shown, the positioning structure 3 includes a docking shell 31 and a turntable 32.
[0057] The docking shell 31 is coaxially disposed on the front side of the main body 1 and fixedly connected to the main body 1. Furthermore, to avoid affecting the sliding connection between the probe rod 2 and the main body 1, the docking shell 31 also has reserved holes 311 suitable for the probe rod 2 to pass through and to avoid the movement trajectory of the probe rod 2. In this embodiment, there are three reserved holes 311, which are spaced apart along the circumference of the docking shell 31.
[0058] The turntable 32 is coaxially disposed on the front side of the main body 1 and between the docking shell 31 and the main body 1, so that the docking shell 31 and the main body 1 respectively abut against the front and rear sides of the turntable 32, restricting the movement of the turntable 32 relative to the main body 1 in the front-rear direction. The turntable 32 is driven by a rotary motor 321 for driving its rotation, and this rotary motor 321 is fixedly connected to the docking shell 31.
[0059] The turntable 32 has multiple beam position holes 322 that are connected to multiple guide holes 11 in a one-to-one manner. Each beam position hole 322 extends outward in an arc shape along the radial direction of the turntable 32, so that when the turntable 32 rotates relative to the main body 1, the connection position between the beam position hole 322 and the guide hole 11 moves along the radial direction of the main body 1, thereby driving the probe 2 to move.
[0060] When measuring data using the borehole depth measuring device provided in this application embodiment, there are situations where the length of the probe 2 is greater than the borehole depth. In this case, when the probe 2 is inserted into the borehole, even if the end of the probe 2 abuts against the bottom of the borehole, the mating shell 31 is still not in contact with the construction surface. At this time, the first infrared rangefinder body 4 is further back than the original testing position, resulting in a larger value and making it impossible to calculate the borehole depth. To solve this problem, in some embodiments, such as... Figure 3 and Figure 4 As shown, a second infrared rangefinder body 5 is fixedly installed on the docking shell 31.
[0061] By adopting the above technical solution, when the probe rod 2 abuts the bottom of the borehole, the second infrared rangefinder body 5 can measure the distance between the docking shell 31 and the construction surface. By combining this data with the data of the first infrared rangefinder body 4 and the thickness of part of the structure itself, the depth of the borehole can be calculated.
[0062] For example: When the probe 2 touches the bottom of the borehole, the value displayed by the first infrared rangefinder body 4 is A, and the value displayed by the second infrared rangefinder body 5 is B. It is known that the distance between the first infrared rangefinder body 4 and the second infrared rangefinder body 5 in the front-to-back direction is C. Then, the depth of the borehole is A-(BC), that is, A-B+C.
[0063] In some embodiments, such as Figure 3 and Figure 4 As shown, a recessed groove 312 is provided on the docking shell 31, and the second infrared rangefinder body 5 is fixedly embedded in the recessed groove 312 to realize the recessed installation of the second infrared rangefinder body 5 relative to the front side of the docking shell 31. This allows the light emission position of the second infrared rangefinder body 5 to coincide with the front side of the docking shell 31, thereby ignoring the influence of the thickness of the second infrared rangefinder body 5 itself on the data measurement.
[0064] A baffle 6 is fitted into the opening of the sink trough 312, and a light-transmitting port 61 is provided on the baffle 6 to allow infrared rays from the second infrared rangefinder body 5 to pass through. The position of the second infrared rangefinder body 5 relative to the docking shell 31 can be limited by this baffle 6.
[0065] In some embodiments, such as Figure 2 and Figure 9 As shown, a mounting frame 7 is provided on the side of the docking shell 31 facing away from the main body 1. The rotating motor 321 is fixedly embedded in the mounting frame 7 to secure the rotating motor 321 itself. Furthermore, the side of the mounting frame 7 facing away from the docking shell 31 has a mounting plate 8. This mounting plate 8 is detachably connected to the mounting frame 7 to allow the mounting plate 8 to abut against the base of the rotating motor 321. The first infrared rangefinder body 4 is fixedly mounted on the side of the mounting plate 8 facing away from the rotating motor 321.
[0066] It should be noted that when participating in the measurement, the data actually measured by the first infrared rangefinder body 4 is the distance between the mounting plate 8 and the bottom of the borehole, which is smaller than the actual required value (i.e., the depth of the borehole). However, since the distance between the mounting plate 8 and the docking shell 31 is fixed, when the first infrared rangefinder body 4 is used, by preset the relevant parameters of the first infrared rangefinder body 4, the actual output value can be made equal to the depth of the borehole.
[0067] For example, if the value detected by the first infrared rangefinder body 4 is A, and the distance between the mounting plate 8 and the docking shell 31 (the preset value) is B, then the value displayed by the first infrared rangefinder body 4 is A+B.
[0068] In some embodiments, such as Figure 9As shown, the mounting frame 7 has a first protrusion 71, and the mounting plate 8 has a second protrusion 81 adapted to overlap with the first protrusion 71; and the first protrusion 71 has a first through hole 711, and the second protrusion 81 has a second through hole 811 adapted to coaxially communicate with the first through hole 711.
[0069] Based on the foregoing, the mounting plate 8 also includes a locking bolt 9 and a stop nut 91.
[0070] The locking bolt 9 is adapted to be inserted into the interconnected first through hole 711 and second through hole 811, and its head abuts against the first protrusion 71 or the second protrusion 81.
[0071] The locking nut 91 is threadedly connected to the locking bolt 9 and is adapted to abut against the second protrusion 81 or the first protrusion 71 to cooperate with the head of the locking bolt 9 and restrict the movement of the mounting plate 8 away from the mounting frame 7.
[0072] In some embodiments, such as Figure 1 , Figure 5 and Figure 6 As shown, the rear end of the probe rod 2 extends out of the guide hole 11, and its extended end has an enlarged diameter portion 21 extending outward along its own radial direction. The side of the probe rod 2 that extends outward has a limiting member 12 connected to the main body 1 and used to abut against the rear side of the enlarged diameter portion 21.
[0073] By adopting the above technical solution, the probe rod 2 can be moved backward by removing the limiting component 12, thereby separating the probe rod 2 from the main body 1.
[0074] In some embodiments, such as Figure 1 and Figure 5 As shown, a handle 13 is fixedly installed on the main body 1.
[0075] When the main body 1 is in contact with the construction surface, the handle 13 is located on the side of the main body 1 facing away from the construction surface, so as to be held by the operator, thereby facilitating the control of the fixed state of the main body 1 (relative to the docking shell 31).
[0076] In some embodiments, such as Figure 2 and Figure 6 As shown, each probe rod 2 is fitted with a rubber sleeve 22.
[0077] By adopting the above technical solution, the probe rod 2 abuts against the inner wall of the borehole through the rubber sleeve 22, thereby reducing the rigid force transmitted from the inner wall of the borehole to the probe rod 2 and preventing damage to the probe rod 2.
[0078] The above content is only a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. A device for measuring the depth of a borehole for use in drill and blast construction, characterised in that, include: The main body adopts a disc-shaped structure and is used to fit onto the construction surface and cover the drill holes; At least three probes are disposed on the main body and arranged at intervals along the circumference of the main body to be suitable for insertion into the borehole; each probe is slidably connected to the main body and is adapted to move toward or away from the central axis of the main body so that each probe abuts against the inner wall of the borehole; A positioning structure is provided on the main body and connected to each of the probes to restrict the movement of the probes relative to the main body; as well as The first infrared rangefinder body is fixedly installed at the center of the main body, so that when each probe abuts against the inner wall of the borehole, the first infrared rangefinder body and the borehole are coaxially arranged.
2. The drilling depth measuring device for drill and blast construction according to claim 1, characterized by, The main body has a plurality of guide holes corresponding one-to-one with the plurality of probes; the plurality of guide holes are arranged at intervals along the circumference of the main body, and each guide hole extends radially along the main body; The probe rod is inserted into the corresponding guide hole and has the freedom to move along the length of the guide hole.
3. The drilling depth measuring device for drill and blast construction according to claim 2, characterized by, The positioning structure includes: A docking shell, coaxially mounted on the main body, has pre-drilled holes suitable for the probe rod to pass through and for avoiding the probe rod's movement trajectory; and A turntable is coaxially mounted on the main body and positioned between the docking shell and the main body; the turntable is driven by a rotating motor for rotating it, and the rotating motor is fixedly connected to the docking shell. The turntable has multiple beam positioning holes that correspond one-to-one with the multiple guide holes; each beam positioning hole extends radially outward in an arc shape along the turntable, so that when the turntable rotates relative to the main body, the connection position of the beam positioning hole and the guide hole moves radially along the main body.
4. The drilling depth measuring device for drill and blast construction according to claim 3, characterized by A second infrared rangefinder body is fixedly installed on the docking shell; When the probe abuts against the bottom of the borehole, the second infrared rangefinder body can measure the distance between the docking shell and the construction surface.
5. The drilling depth measuring device for drill and blast construction according to claim 4, characterized by, The docking shell is provided with a recessed groove, and the second infrared rangefinder body is fixedly embedded in the recessed groove. A baffle is fitted into the opening of the sinking trough, and the baffle has a light-transmitting port suitable for the infrared rays of the second infrared rangefinder body to pass through.
6. The drilling depth measuring device for drill and blast construction according to claim 3, wherein The docking shell has a mounting frame on the side facing away from the main body, and the rotating motor is fixedly embedded in the mounting frame; the mounting frame has a mounting plate detachably connected to it on the side facing away from the docking shell, the mounting plate is adapted to abut against the rotating motor, and the first infrared rangefinder body is fixedly mounted on the mounting plate.
7. The drilling depth measuring device for drill and blast construction according to claim 6, characterized by, The mounting frame has a first protrusion, and the mounting plate has a second protrusion adapted to overlap with the first protrusion; the first protrusion has a first through hole, and the second protrusion has a second through hole adapted to coaxially communicate with the first through hole; the mounting plate further includes: A locking bolt, adapted to be inserted into the interconnected first and second through holes, with its head abutting against the first or second protrusion; and A stop nut, threadedly connected to the locking bolt, is adapted to abut against the second protrusion or the first protrusion to cooperate with the head of the locking bolt and restrict the movement of the mounting plate away from the mounting frame.
8. The drilling depth measuring device for drill and blast construction according to claim 2, characterized by, The end of the probe extends out of the guide hole, and its extended end has an enlarged diameter portion extending outward along its own radial direction. The side of the probe extending outward has a limiting member connected to the main body for abutting the enlarged diameter portion.
9. The drilling depth measuring device for drill and blast construction according to claim 1, characterized by, A handle is fixedly provided on the main body; When the main body is in contact with the construction surface, the handle is located on the side of the main body facing away from the construction surface, for the operator to hold.
10. The drilling depth measuring device for drill and blast construction according to claim 1, characterized by, Each of the probes is fitted with a rubber sleeve.