A device for measuring the inner diameter of a borehole

Abstract

This invention provides a device for measuring the inner diameter of a borehole, comprising a graduated steel wire, a flexible steel wire, a pre-compressed multi-layered compression spring assembly, a flexible metal tube, and a directional deployment mechanism. During operation, the spring assembly deploys evenly within the borehole wall through a guide opening, forming a fixed angle. The displacement of the flexible steel wire is directly displayed by the surface scale, and the borehole diameter can be quickly calculated using preset parameters. The flexible tube protects the internal structure from environmental interference.

Description

Technical Field

[0001] This utility model relates to the field of borehole inner diameter measurement technology, and more specifically, to a deep borehole inner diameter measurement device suitable for complex environments such as open-pit mine blasting holes and geological boreholes. Background Technology

[0002] Deep hole diameter measurement (e.g., blasting holes in open-pit mines, geological drilling holes) is crucial for setting blasting parameters and engineering safety, but traditional methods have significant drawbacks. Mechanical contact-type measuring instruments use rigid probes that unfold to contact the hole wall; their mechanical structure is complex, they are only suitable for short holes and depend on regular hole wall conditions, and are prone to jamming and failure in dusty or waterlogged environments. Electronic sensor borehole measuring instruments can improve accuracy, but require precision pressure sensors or laser modules, which are costly, and the data cables and battery components have depth limitations, making them unsuitable for long-term operation in harsh environments. In addition, traditional telescopic rod calibration methods (such as experience-based methods in mines) are inefficient, highly susceptible to human reading errors, and cannot adapt to local changes in hole diameter or curved channels. None of the above technical solutions can simultaneously meet the core requirements of high accuracy, operational stability, and adaptability to long depths in deep hole measurement. Especially in complex hole wall structures and outdoor environments, existing measuring instruments generally face insurmountable contradictions such as structural jamming, signal distortion, or short lifespan, resulting in insufficient reliability and low efficiency of measurement data. Summary of the Invention

[0003] To address the aforementioned technical issues, a simple, high-precision measuring device suitable for harsh environments is provided. This device enables rapid and stable measurement of long-distance (50-meter) deep holes by utilizing the quantitative relationship between the direct displacement of a steel wire and the hole diameter.

[0004] The technical means adopted in this utility model are as follows:

[0005] A device for measuring the inner diameter of a borehole, comprising:

[0006] The gripping part has its bottom fixedly connected to the top of the flexible metal tube by a rigid connector, and an axial through hole is provided inside the gripping part;

[0007] A steel wire with graduation marks, one end of which has no graduation marks and passes through the through hole, the cavity of the flexible metal tube, and the central axial channel of the straight tube, and is finally fixed to the end of a multi-layer compression spring assembly provided at the end of the straight tube; the other end of the steel wire has graduation marks and is exposed at the gripping part to directly read the displacement.

[0008] The multi-layer compression spring assembly is pre-compressed and stored inside the straight tube, and the side wall of the straight tube is provided with symmetrical arc-shaped guide openings. When the spring assembly unfolds and contacts the hole wall, the guide openings constrain its unfolding direction and limit the orientation angle θ (25°±3°). At the same time, the steel wire cord generates an axial displacement ΔL due to the lateral expansion of the spring unfolding. The value of ΔL is directly displayed through the scale markings exposed on the gripping part.

[0009] Furthermore, the steel wire is made of bend-resistant stainless steel, and the minimum graduation value of the surface scale markings is 0.5mm;

[0010] The multi-layer compression spring assembly consists of at least three layers of helical springs stacked in layers, with the ends of each layer connected in series by a ring-shaped fixing clip to maintain synchronous elongation during unfolding.

[0011] Furthermore, the arc-shaped guide opening of the straight tube is a symmetrical semi-circle, and the opening radius matches the free-expanding outer diameter of the compression spring assembly;

[0012] The end of the steel wire is locked in the end fixing clip of the multi-layer compression spring assembly by a threaded locking member to ensure that the displacement of the steel wire and the total elongation of the spring assembly are in a 1:1 force transmission ratio.

[0013] Furthermore, the outer surface of the flexible metal conduit is provided with depth scale markings, and its end is detachably threaded to the straight pipe 4.

[0014] Furthermore, the steel wire is clearance-fitted with the central axial channel of the straight tube, and the inner wall of the channel is provided with anti-friction protrusions to reduce the additional resistance when the steel wire slides.

[0015] The core principle of this utility model, which adopts the above technical solution, is based on the physical mechanism of mechanical linkage displacement transmission and force balance of multi-layer spring group. It achieves high-precision dynamic measurement through the quantitative relationship between the axial displacement ΔL of the steel wire and the inner diameter W of the deep hole.

[0016] This invention transforms the physical contact problem of deep hole inner diameter measurement into a direct and visual measurement of wire displacement, breaking through the bottlenecks of traditional methods in terms of accuracy, depth, and environmental adaptability. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1This is a schematic diagram of the structure of this utility model when it is assembled and not in use.

[0019] Figure 2 This is a schematic diagram of the structure of this utility model in use.

[0020] In the diagram: 1. Grip; 1a. Axial through hole; 2. Steel wire; 3. Flexible metal conduit; 4. Straight tube; 5a-5b. Arc-shaped guide opening; 6-7. Multi-layer compression spring assembly; 8. Scale clamp. Detailed Implementation

[0021] It should be noted that, where there is no conflict, the embodiments and features in the embodiments of this utility model can be combined with each other. The present utility model will now be described in detail with reference to the accompanying drawings and embodiments.

[0022] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this utility model or its application or use. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0023] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to the present invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0024] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0025] In the description of this utility model, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this utility model and simplifying the description. Unless otherwise stated, these directional terms 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, and therefore should not be construed as a limitation on the scope of protection of this utility model. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0026] For ease of description, spatial relative terms such as "above," "over," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation besides the orientation of the device as described in the figures. For example, if the device in the figures is inverted, a device described as "above" or "above" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0027] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be construed as limiting the scope of protection of this utility model.

[0028] like Figure 1 and Figure 2 As shown, this utility model provides a device for measuring the inner diameter of a borehole, comprising:

[0029] The gripping part 1 has its bottom fixedly connected to the top end of the flexible metal tube 3 via a rigid connector, and an axial through hole 1a is provided inside the gripping part;

[0030] A steel wire 2 with graduation marks, one end of which has no graduation marks and passes through the through hole 1a, the cavity of the flexible metal tube 3, and the central axial channel of the straight tube 4, and is finally fixed to the end of the multi-layer compression spring group (6, 7) provided at the end of the straight tube; the other end of the steel wire 2 has graduation marks and is exposed on the grip part 1 to directly read the displacement.

[0031] The multi-layer compression spring assembly (6, 7) is pre-compressed and stored inside the straight tube 4, and the straight tube 4 has symmetrical arc-shaped guide openings (5a, 5b) on its side wall. When the spring assembly unfolds and contacts the hole wall, the guide openings constrain its unfolding direction and limit the orientation angle θ (25°±3°). At the same time, the steel wire 2 generates an axial displacement ΔL due to the lateral expansion of the spring unfolding. The value of ΔL is directly displayed through the scale markings exposed on the gripping part.

[0032] Furthermore, the steel wire 2 is made of bend-resistant stainless steel, and the minimum graduation value of the surface scale marking is 0.5mm;

[0033] The multi-layer compression spring group (6, 7) consists of at least 3 layers of helical springs stacked in layers, with the ends of each layer connected in series by a ring-shaped fixing clip to maintain synchronous elongation when unfolded.

[0034] Furthermore, the arc-shaped guide openings (5a, 5b) of the straight tube 4 are symmetrical semicircles, and the opening radius matches the free unfolding outer diameter of the compression spring assembly;

[0035] The end of the steel wire 2 is locked in the end fixing clip of the multi-layer compression spring assembly by a threaded locking member to ensure that the displacement of the steel wire and the total elongation of the spring assembly are in a 1:1 force transmission ratio.

[0036] Furthermore, the outer surface of the flexible metal conduit 3 is provided with depth scale markings, and its end is detachably threaded to the straight pipe 4.

[0037] Furthermore, the steel wire 2 is clearance-fitted with the central axial channel of the straight tube 4, and the inner wall of the channel is provided with anti-friction protrusions to reduce the additional resistance when the steel wire slides.

[0038] In this utility model employing the above technical solution, when the device is inserted into the deep hole to a predetermined depth, the multi-layer compression spring assembly (6, 7) at the end of the straight tube 4 unfolds due to the supporting force of the hole wall. Because the spring assembly is limited by the inner cavity of the straight tube 4 and the guide openings (5a, 5b), the included angle θ of the lateral expansion remains stable (preset to 25°±3°).

[0039] The lateral extension of the spring assembly (i.e., the maximum lateral width Wext) is geometrically proportional to the axial displacement ΔL of the steel wire 2.

[0040] The ungraded end of the flexible steel wire 2 passes through the through hole 1a of the gripping part → the inner cavity of the flexible conduit → the center channel of the straight tube, ensuring a seamless axial displacement transmission path (friction coefficient ≤ 0.05). The lateral expansion of the spring assembly is directly converted into a readable scale change through the steel wire displacement ΔL, avoiding signal attenuation.

[0041] Multilayer compression spring component layered design:

[0042] At least three layers of springs are connected in series by a ring-shaped fixing clip to form a force-distributing structure. Each spring layer only bears about 1 / 3 of the total pressure, effectively eliminating the cumulative deformation caused by the unevenness (±3mm) of the local hole wall of a single spring (the deformation error of a single layer can be reduced by 70%), while ensuring synchronous deployment.

[0043] The arc-shaped guide opening (5a-5b) of the straight tube 4 physically limits the range of the θ angle, and the opening diameter (e.g., Φ18mm) matches the free unfolding width of the spring.

[0044] The specific usage steps are as follows:

[0045] Step 1: Assembly and Calibration (only for first use or when not in use)

[0046] Component connection:

[0047] Ensure that both ends of the flexible metal conduit 3 are threadedly connected to the gripping part 1 and the straight tube 4 respectively (M30×2 and M25×1.5 external threads).

[0048] The multi-layer compression spring assembly (6-7) needs to be pre-compressed to its initial length (e.g., 180mm) and placed inside the straight tube (4).

[0049] After the unmarked end of the steel wire 2 passes through the channel, it is fixed to the end of the spring by a ring-shaped fixing clip and a locking device;

[0050] Adjust the grip part 1 so that the "0" mark of the steel wire scale is aligned with the reference line on the surface of the grip part to complete the zero point calibration.

[0051] Compare and statistically analyze the end expansion of the multi-layer compression spring group (6, 7) with the movement of the steel wire 2 to form a table showing the correspondence between the end expansion change of the multi-layer compression spring group (6, 7) and the movement ΔL of the steel wire 2.

[0052] Step 2: Determine the target depth

[0053] Two people work together to vertically lower the flexible conduit 3 to the target depth (read the value through the scale markings on the outer wall).

[0054] Example: When measuring the diameter of the hole at -30 meters, use the scale clamp 8 to clamp the flexible conduit 3 at the -30 meter position. Stop lowering when the outer wall of the conduit displays "-30m", that is, when the scale clamp 8 is tightly attached to the hole or partially embedded.

[0055] Ensure that the straight pipe 4 is fully inserted into the hole, leaving the gripping part 1 and the middle section of the pipe outside for easy operation;

[0056] Slowly lift the gripping part 1 about 50mm (leaving room for operation) to disengage the end of the straight tube 4 from the constraint groove; and loosen the scale end of the steel wire 2.

[0057] The spring assembly automatically unfolds after being subjected to the reaction force of the hole wall (the included angle θ is maintained at 25°±3°), pushing the steel wire 2 to generate a displacement ΔL;

[0058] Observe the scale line on the steel wire, and record the value of ΔL when the scale changes stop (error ≤ 0.1mm within about 3 seconds).

[0059] Compare the changes in the unfolded ends of the corresponding multi-layer compression spring groups (6, 7) in the table. Add this change value to the initial length of the multi-layer compression spring groups (6, 7) in the unfolded state to get the inner diameter.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A device for measuring the inner diameter of a borehole, characterized in that, include: The gripping part has its bottom fixedly connected to the top of the flexible metal tube by a rigid connector, and an axial through hole is provided inside the gripping part; A steel wire with graduation marks, one end of which has no graduation marks and passes through the through hole, the cavity of the flexible metal tube, and the central axial channel of the straight tube, and is finally fixed to the end of a multi-layer compression spring assembly provided at the end of the straight tube; the other end of the steel wire has graduation marks and is exposed at the gripping part to directly read the displacement. The multi-layer compression spring assembly is pre-compressed and stored in the inner cavity of the straight tube, and the side wall of the straight tube is provided with symmetrical arc-shaped guide openings. When the spring assembly unfolds and contacts the hole wall, the guide openings constrain its unfolding direction and limit the orientation angle θ (25°±3°). At the same time, the steel wire cord generates an axial displacement ΔL due to the lateral expansion of the spring unfolding. The value of ΔL is directly displayed through the scale markings exposed on the gripping part.

2. The device for measuring the inner diameter of a borehole according to claim 1, characterized in that: The steel wire is made of bend-resistant stainless steel, and the minimum graduation value of the surface scale markings is 0.5mm; The multi-layer compression spring assembly consists of at least three layers of helical springs stacked in layers, with the ends of each layer connected in series by a ring-shaped fixing clip to maintain synchronous elongation during unfolding.

3. A device for measuring the inner diameter of a borehole according to any one of claims 1-2, characterized in that: The arc-shaped guide opening of the straight tube is a symmetrical semi-circle, and the opening radius matches the free unfolding outer diameter of the compression spring assembly; The end of the steel wire is locked in the end fixing clip of the multi-layer compression spring assembly by a threaded locking member to ensure that the displacement of the steel wire and the total elongation of the spring assembly are in a 1:1 force transmission ratio.

4. The device for measuring the inner diameter of a borehole according to claim 3, characterized in that: The steel wire is fitted with the central axial channel of the straight tube with a clearance, and the inner wall of the channel is provided with anti-friction serrations to reduce the additional resistance when the steel wire slides.

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