While-drilling hole depth measuring device suitable for underground coal mine

Abstract

The invention belongs to the technical field of drilling depth measurement, and particularly relates to a while-drilling hole depth measuring device suitable for an underground coal mine, which comprises a stator shell, a rotor baffle, a driven wheel, a pressing assembly and a coding wheel, the stator shell is circular and is fixedly connected with a front clamp holder of a drill rod, and the rotor baffle is rotatably mounted in the stator shell; the driven wheel and the coding wheel are oppositely arranged on the two sides of the drill rod and installed on the rotor baffle, and the pressing assembly enables the driven wheel and the coding wheel to clamp the drill rod through elasticity. When the drill rod rotates and does not advance, the rotor baffle, the driven wheel, the coding wheel and the drill rod coaxially rotate, and when the drill rod advances, the driven wheel and the coding wheel rotate; through the above structure, the propulsion of the drill rod is decoupled, the rotation of the coding wheel is only influenced by the axial movement of the rotating rod, the measurement precision is ensured, the rotor baffle plate is flexibly clamped on the drill rod through the pressing assembly, so that the rotor baffle plate can adapt to certain disturbance, and the measurement precision is further improved.

Description

Technical Field

[0001] This invention relates to the field of borehole depth measurement technology, and specifically to a borehole depth measurement device suitable for use in underground coal mines. Background Technology

[0002] In underground coal mines, borehole depth measurement is an essential procedure. Specific depth measurements ensure that the borehole penetrates the target coal seam or gas-rich area, and are crucial for drawing accurate geological profiles and understanding the coal seam occurrence conditions.

[0003] The prior art (CN219061616U) discloses a continuous drilling depth measuring device, which includes a roller with a photoelectric encoder. The axis of the roller's rotation shaft intersects the axis of the drill rod. A tension spring keeps the roller in contact with the drill rod, thereby forcing the roller to rotate when the drill rod is advanced. The drilling depth is calculated by counting the number of rotations of the roller.

[0004] The above-mentioned solution has the following problems during use: 1. The drill rod advance can be decomposed into rotational motion and axial motion. Ideally, the roller and the drill rod are in point contact, and the roller will only respond to the axial motion of the drill rod and will not respond to the rotational motion. However, in reality, the roller is squeezed on the drill rod, forming a small contact area. This area has width. Once the drill rod rotates, it will also drive the roller to rotate. In reality, the device actually measures the composite linear velocity of the drill rod surface. Therefore, additional sensors or theoretical calculations are needed to distinguish pure axial displacement, which is prone to errors. 2. The roller does not follow the drill rod advance and should be placed on the ground. The jumping and bending of the drill rod will directly affect the pressure and contact of the roller, thus affecting the measurement accuracy. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the purpose of this invention is to provide a drilling depth measurement device suitable for underground coal mines, which has high measurement accuracy and better stability.

[0006] The technical solution adopted in this invention is as follows: A drilling depth measuring device suitable for underground coal mines includes a stator housing, a rotor baffle, a driven wheel, a clamping assembly, and a coding wheel; The stator housing is circular and is fixedly connected to the front clamp of the drill pipe. The rotor baffle is rotatably installed inside the stator housing. The driven wheel and the encoder wheel are positioned opposite each other on both sides of the drill rod and are mounted on the rotor baffle. The clamping assembly uses elasticity to clamp the drill rod with the driven wheel and the encoder wheel. When the drill rod is rotating but not advancing, the rotor baffle, driven wheel, and encoder wheel rotate coaxially with the drill rod. When the drill rod advances, the driven wheel and encoder wheel rotate on their own.

[0007] Working principle: When the drill rod rotates, the friction will cause the entire rotor baffle to rotate freely along the stator housing. When the drill rod is pushed axially, it will push the entire rotor assembly (including the encoder wheel and driven wheel) forward. The rotor is fixed to the front clamp by the stator, which is converted into the rotation of the encoder wheel. The encoder wheel records and uploads the number of revolutions through wireless transmission.

[0008] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. Through the above structure, the advance of the drill rod is decoupled, and the rotation of the encoder wheel itself is only affected by the axial movement of the rotating rod, thus ensuring measurement accuracy; 2. The front clamp is integrated with the drill rig body. Due to its large weight, the drill rig body is relatively stable. When the drill rod jumps, the stator housing rigidly limits the rotor baffle, which can effectively suppress and control the jumping energy. When the drill rod bends, the rotor baffle is flexibly clamped on the drill rod by the clamping assembly, which can adapt to certain disturbances, thereby improving the measurement accuracy.

[0009] In a preferred embodiment of the present invention, the clamping assembly includes a first frame and a clamping spring. The driven wheel is rotatably mounted on a second frame, the second frame is slidably mounted on a rotor baffle, one end of the clamping spring is fixedly mounted on the first frame, and the other end of the clamping spring abuts against the second frame, forcing the driven wheel to be in close contact with the drill rod.

[0010] Beneficial effects: The above settings allow the clamping spring to apply pressure to the drill rod through the driven wheel, ensuring that the encoder wheel and the driven wheel are always clamped to the drill rod, and can also adapt to drill rods of different diameters within a certain range.

[0011] In a preferred embodiment of the present invention, the driven wheel is a grooved wheel and the coding wheel is a flat roller.

[0012] Beneficial effects: The contact area between the grooved wheel and the drill rod is a recessed area, which can achieve a certain degree of centering effect, increase the contact area, and make it more stable; the encoder wheel adopts a flat roller body, which makes its measurement accuracy more accurate. The combination of the two enables it to achieve accurate measurement in high vibration environment.

[0013] In a preferred embodiment of the present invention, an annular groove is provided on the inner side of the stator housing, and multiple rollers are rotatably mounted on the rotor baffle. The multiple rollers are evenly distributed circumferentially and all roll along the annular groove.

[0014] Beneficial effects: By setting up the above, sliding friction is transformed into rolling friction, resulting in minimal resistance and lower wear. Multiple evenly distributed rollers can disperse various radial impact forces and vibration forces transmitted from the drill rod to multiple points, avoiding stress concentration. When the drill rod experiences radial runout, it will attempt to push the rotor baffle away from the center position. Three or more rollers can form a stable support structure to jointly resist this force and prevent the rotor baffle from jamming.

[0015] In a preferred embodiment of the present invention, the stator housing includes two semi-rings, which are fixed together by bolts.

[0016] Beneficial effects: The stator housing is composed of two detachable semi-rings, which can be disassembled and assembled at any time without having to be inserted from the end of the drill rod.

[0017] In a preferred embodiment of the present invention, a battery box is also included, which is mounted on the rotor baffle and supplies power to the encoder wheel.

[0018] Beneficial effect: When it is necessary to replace the battery in the battery box, the individual half rings can be disassembled, which is more convenient.

[0019] As a preferred embodiment of the present invention, it also includes a four-corner bracket. The stator housing is provided with four lugs, which are fixed to the four-corner bracket by bolts. The four-corner bracket can be fixed to the front clamp by bolts.

[0020] Beneficial effect: By setting up four corner brackets to connect the stator housing to the front clamp, the structure is made more stable.

[0021] In a preferred embodiment of the present invention, a cylinder displacement sensor is also included, which is used to detect the displacement distance of the drilling rig's propulsion cylinder.

[0022] Beneficial effects: The cylinder displacement value is affected by errors in elastic deformation, mechanical clearance, slippage, and non-production stroke, and can ultimately yield the actual advance value of the drill pipe. Its measurement accuracy is relatively low. However, in the absence of mechanical failure, the difference between the cylinder displacement value and the actual advance value should be kept within a certain range. Therefore, by checking whether this difference exceeds the range, the measuring device can be verified. If the difference is too large, it indicates that a mechanical failure has occurred and repair is required. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of a first embodiment of the borehole depth measurement device applicable to underground coal mines according to the present invention; Figure 2 This is a schematic diagram of the internal structure of the drilling depth measurement device of the present invention applicable to underground coal mines, according to Embodiment 1; Figure 3This is a schematic diagram of the stator housing and rotor baffle in Embodiment 1 of the drilling depth measurement device applicable to underground coal mines of the present invention; Figure 4 This is a front view of the rotor baffle in Embodiment 3 of the drilling depth measurement device applicable to underground coal mines of the present invention; Figure 5 This is a partial cross-sectional view of Embodiment 3 of the drilling depth measurement device applicable to underground coal mines according to the present invention.

[0024] The reference numerals in the attached drawings include: stator housing 1, semi-annular body 11, annular groove 12, rotor baffle 2, roller 21, driven wheel 3, second frame 31, encoder wheel 4, third frame 41, first frame 5, four corner brackets 6, battery box 7, drill rod 8, heat dissipation hole 91, guide hole 92, guide plate 93, and flow channel 94. Detailed Implementation

[0025] Typical embodiments embodying the features and advantages of the present invention will be specifically described in the following description. It should be understood that the present invention can have various variations in different embodiments without departing from the scope of the present invention, and the descriptions and illustrations herein are for illustrative purposes only and not intended to limit the present invention.

[0026] In the description of this application, the terms "first", "second", etc. are used only for the convenience of describing this application and simplifying the description, and are not intended to indicate or imply that the structure 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 of this application.

[0027] Example 1: See Figures 1 to 3 As shown in the figure, this embodiment discloses a drilling depth measurement device suitable for underground coal mines, including a stator housing 1, a rotor baffle 2, a driven wheel 3, a clamping assembly, an encoder wheel 4, and a four-corner bracket 6.

[0028] Among them, see Figure 3 As shown, the stator housing 1 includes two semi-rings 11, each with an annular groove 12. The two semi-rings 11 can be assembled with bolts to form a circular guide rail through the annular groove 12. It also includes a back plate, which is used to limit the rotor baffle 2 circumferentially on one side. The stator housing 1 is provided with lugs, which can be connected to the four corner brackets 6 with bolts. The four corner brackets 6 can be connected to the front clamp with bolts.

[0029] Among them, see Figure 2 and Figure 3As shown, a plurality of rollers 21 are circumferentially rotatably mounted on the rotor baffle 2. The rollers 21 roll along a circular guide rail. The rotor baffle 2 and the stator housing 1 should have through holes in the middle, and are fitted onto the drill rod 8 without contacting the drill rod 8. The clamping assembly includes a first frame 5 and a clamping spring (not shown in the figure). The driven wheel 3 is rotatably mounted on a second frame 31, which is slidably mounted on the rotor baffle 2. One end of the clamping spring is fixedly mounted on the first frame 5, and the other end of the clamping spring abuts against the first frame 5. On the second frame 31, the driven wheel 3 is forced to be in close contact with the drill rod 8; the driven wheel 3 and the encoder wheel 4 are arranged opposite each other on both sides of the drill rod 8, and the encoder wheel 4 is rotatably mounted on the third frame 41, which is fixedly mounted on the rotor baffle 2 by bolts; when the drill rod 8 rotates, the friction will drive the entire rotor baffle 2 to rotate along the stator housing 1; when the drill rod 8 is axially advanced, there will be a tendency to push the entire rotor assembly forward, and the rotor is fixed on the front clamp by the stator, thus converting it into the rotation of the encoder wheel 4.

[0030] The encoder wheel 4 is equipped with a rotary encoder, a microcontroller chip, and a wireless communication module. The rotary encoder converts the rotation angle or speed into an electrical signal through photoelectric or electromagnetic principles. The microcontroller chip processes the data and transmits it to the user terminal through the wireless communication module. The above working process is existing technology and will not be described in detail here.

[0031] The driven wheel 3 is a grooved wheel, and the coding wheel 4 is a flat roller. The contact area between the grooved wheel and the drill rod 8 is a recessed area, which can achieve a certain degree of centering effect, increase the contact area, and make it more stable. The coding wheel 4 is a flat roller, which has more accurate measurement accuracy. The combination of the two enables it to achieve accurate measurement in a high vibration environment.

[0032] It also includes a battery box 7, which is installed on the rotor baffle 2 to power the encoder wheel 4. With the help of the wireless transmission module, the whole system does not require wired connection for external signal transmission and power supply, thus avoiding damage to the lines in high vibration environments.

[0033] Example 2: Based on the first embodiment, the present invention also provides a drilling depth measurement device suitable for underground coal mines, which further includes a cylinder displacement sensor. The cylinder displacement sensor adopts the Schaevitz MRU series displacement sensor. The cylinder displacement sensor is used to detect the displacement distance of the drilling rig's propulsion cylinder. Under the influence of elastic deformation, mechanical clearance, slippage, and non-production stroke errors, the cylinder displacement value can finally obtain the actual propulsion value of the drill rod 8. Its measurement accuracy is relatively low. However, when there is no mechanical failure, the difference between the cylinder displacement value and the actual propulsion value should be kept within a certain range. Therefore, by detecting whether the difference exceeds the range, the measuring device can be verified. When the difference is too large, it indicates that a mechanical failure has occurred and maintenance is required.

[0034] Example 3: See Figure 4 and Figure 5 As shown, the stator housing 1 has multiple heat dissipation holes 91 circumferentially arranged on its side wall, and the rotor baffle 2 has multiple guide holes 92 circumferentially arranged. The guide holes 92 open towards the inner side of the stator housing 1. The rotor baffle 2 has a flow channel 94 inside, one end of which is connected to the guide hole 92, and the other end is inclined inward and towards the drill rod 8. A guide plate 93 (with an inclined or curved slope) is installed inside the guide hole 92, extending out of the guide hole 92. When the rotor baffle 2 rotates, it drives the multiple guide plates 93, causing the guide holes 92 to rotate, forming an airflow from the outside of the heat dissipation holes 91 to the inside of the stator housing 1. The airflow is guided by the guide plates 93 into the guide holes 92 and then blown out obliquely through the flow channel 94. Figure 4 The middle arrow indicates the direction of airflow guided by the guide hole 92 on one side.

[0035] The rotor baffle 2 is made of a material with good thermal conductivity (copper-based alloy is used in this scheme). When the rotor baffle 2 is in the rotating state, the gas flows into the drainage channel 4, so that there is airflow in the inner rotor baffle 2, thereby making the temperature of the rotor baffle 2 lower. Since the battery box 7 is in direct contact with the rotor baffle 2, the rotor baffle 2 can be used as a heat sink for the battery box 7.

[0036] Through the aforementioned structure, the inwardly positioned guide holes 92 allow the airflow path to pass through the outer wall of the battery box 7, thus dissipating heat from the battery box 7. Combined with the thermal conductivity of the rotor baffle 2, this prevents the battery box 7 from overheating. Furthermore, the airflow direction can carry away dust from inside the stator housing 1, preventing excessive internal dust accumulation and affecting the service life of other working components. Due to the working environment, dust and impurities easily adhere to the drill rod 8, causing the drill rod 8 to not make direct contact with the encoder wheel 4, which in turn leads to deviations in the measurement data. The airflow generated in this solution, blown out at an angle, can clean the surface of the drill rod 8 to a certain extent, ensuring the measurement accuracy as much as possible.

[0037] In other embodiments, the diameter of the drainage channel 94 can be set to gradually decrease. The smaller diameter increases the airflow velocity in this section, resulting in a lower temperature and thus improving the heat dissipation effect.

[0038] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A drilling depth measurement device suitable for underground coal mines, characterized in that: Includes stator housing, rotor baffle, driven wheel, clamping assembly, and encoder wheel; The stator housing is circular and is fixedly connected to the front clamp of the drill pipe. The rotor baffle is rotatably installed inside the stator housing. The driven wheel and the encoder wheel are positioned opposite each other on both sides of the drill rod and are mounted on the rotor baffle. The clamping assembly uses elasticity to clamp the drill rod with the driven wheel and the encoder wheel. When the drill rod is rotating but not advancing, the rotor baffle, driven wheel, and encoder wheel rotate coaxially with the drill rod. When the drill rod advances, the driven wheel and encoder wheel rotate on their own.

2. The drilling depth measuring device for underground coal mines according to claim 1, characterized in that: The clamping assembly includes a first frame and a clamping spring. The driven wheel is rotatably mounted on a second frame, which is slidably mounted on a rotor baffle. One end of the clamping spring is fixedly mounted on the first frame, and the other end of the clamping spring abuts against the second frame, forcing the driven wheel to be in close contact with the drill rod.

3. The drilling depth measuring device for underground coal mines according to claim 2, characterized in that: The driven wheel is a grooved wheel, and the coding wheel is a flat roller.

4. The drilling depth measuring device for underground coal mines according to claim 1, characterized in that: The stator housing has an annular groove on its inner side, and multiple rollers are rotatably mounted on the rotor baffle. The multiple rollers are evenly distributed circumferentially and all roll along the annular groove.

5. The drilling depth measuring device for underground coal mines according to claim 1, characterized in that: The stator housing comprises two semi-rings, which are fixed together by bolts.

6. The drilling depth measuring device for underground coal mines according to claim 1, characterized in that: It also includes a battery box, which is mounted on the rotor baffle and supplies power to the encoder wheel.

7. The drilling depth measuring device for underground coal mines according to claim 1, characterized in that: It also includes a four-corner bracket. The stator housing has four lugs, which are fixed to the four-corner bracket by bolts. The four-corner bracket can be fixed to the front clamp by bolts.

8. The drilling depth measuring device for underground coal mines according to claim 1, characterized in that: It also includes a cylinder displacement sensor, which is used to detect the displacement distance of the drilling rig's propulsion cylinder.

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