A self-powered vibration measurement sensor for coal mine drilling

Abstract

This invention discloses a self-powered vibration measurement sensor for coal mine drilling, comprising a housing and an end cap, which are sealed by screw connection. A vibration table is disposed in the cavity in the middle of the housing. A copper electrode layer and a Kapton sensing layer are disposed on the upper surface of the vibration table, and a copper electrode layer and a silicone film sensing layer are disposed on the lower side of the end cap. The positions of the copper electrode layer and the Kapton sensing layer correspond to those of the copper electrode layer and the silicone film sensing layer. The greatest advantage of this invention is its self-powered nature. This sensor does not require an external power supply, saving downhole space during installation. At the same time, this type of sensor also has a series of advantages such as low cost, simple structure, and high efficiency at low frequencies. This invention has a simple structure, high reliability, and is not prone to distortion.

Description

Technical Field

[0001] This invention relates to the field of geological instrumentation technology, specifically to a self-powered vibration measurement sensor for coal mine drilling. Background Technology

[0002] my country is a major coal producer and consumer, and its coal reserves are abundant, ranking among the world's top. Therefore, my country has invested considerable effort in the research of coal resource exploration and mining technologies, and has made many progresses. Today, coal mine drilling equipment is also transforming from mechanization to intelligentization.

[0003] During the drilling process, drilling and logging are crucial steps. Vibrations generated by the drill bit during drilling can negatively impact the drilling work, such as accelerating the wear of the drill bit.

[0004] In recent years, with the deepening of research, researchers have gained a more profound understanding of the vibration mechanism of drill strings. Drill string vibration is classified into three types: longitudinal vibration, lateral vibration, and torsional vibration. Among these three, longitudinal vibration is the most harmful and also the most frequent. During the drilling process, the drill bit is subjected to formation pressure, causing it to jump and vibrate. Axial vibration of the drill string can damage the drill bit, and in severe cases, it can even affect the entire drilling rig and damage the surface structure.

[0005] Against this backdrop, axial vibration of the drill string has become one of the important parameters measured by logging instruments. Traditional vibration measurement sensors can be classified into the following types according to the physical properties of the measurement process: mechanical, optical, and electrical. Mechanical vibration sensors have the advantages of simple structure and easy installation and use, but this structure has poor accuracy and can measure a low frequency. Optical sensors rely on optical systems to amplify the captured vibration signal, which is convenient for recording and display, but this structure is obviously not suitable for use in coal mines. Electrical sensors convert the captured vibration signal into an electrical signal for output, and this structure is also the most widely used. Summary of the Invention

[0006] The purpose of this invention is to provide a self-powered vibration measurement sensor for coal mine drilling, belonging to the electrical measurement method, which can be used to measure the vibration of coal mine drilling tools. Specifically, it can reflect parameters such as vibration frequency, amplitude and acceleration, thereby overcoming the shortcomings of the prior art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a self-powered vibration measurement sensor for coal mine drilling, comprising an outer shell and an end cap, wherein the outer shell and the end cap are sealed by screw connection; a vibration table is disposed in the cavity in the middle of the outer shell; a copper electrode layer and a Kapton sensing layer are disposed on the upper surface of the vibration table; and a copper electrode layer and a silicone film sensing layer are disposed on the lower side of the end cap; the positions of the copper electrode layer and the Kapton sensing layer correspond to those of the copper electrode layer and the silicone film sensing layer; during the longitudinal vibration of the drill string, the vibration table is driven to reciprocate up and down, causing the copper electrode layer and the Kapton sensing layer to cyclically contact and separate from the copper electrode layer and the silicone film sensing layer, thereby inducing electricity; and the frequency of the output voltage signal can reflect the vibration frequency of the drill string.

[0008] As a further aspect of the present invention: a buffer bladder made of rubber is provided between the end cap and the copper electrode layer and the silicone film sensing layer, and the buffer bladder is filled with buffer solution.

[0009] As a further embodiment of the present invention: a sleeve is provided at the bottom of the cavity in the middle of the outer shell, and a moving rod is fixedly provided on the lower surface of the vibration table. The moving rod is embedded in the sleeve and can reciprocate along the direction of the sleeve. The sleeve can ensure that the vibration table does not tilt during the reciprocating vibration process.

[0010] As a further aspect of the present invention: a spring is fitted onto the sleeve, and the spring is engaged between the vibration table and the inner bottom surface of the outer shell to initiate the vibration of the vibration table.

[0011] As a further embodiment of the present invention: rollers of the same specifications are symmetrically arranged around the vibration table, a layer of PTFE film is laid on the surface of the rollers, and multiple rows of copper electrodes are symmetrically attached to the inner wall of the outer shell. The rollers are stuck between the vibration table and the corresponding copper electrodes. During the vibration of the vibration table, the rollers reciprocate, and the PTFE film on the rollers comes into contact with the corresponding copper electrodes at different positions and generates electricity through friction, outputting the corresponding voltage signal.

[0012] As a further aspect of the present invention: multiple pairs of copper electrodes are provided on each row of copper electrodes; the width of each pair of copper electrodes is different, but the curvature is equal; since the width of each pair of electrodes is different, the output voltage value is also different, and the amplitude can be reflected by the output voltage value here, and the corresponding acceleration value can also be calculated by the time difference of the output signal between the electrodes.

[0013] As a further aspect of the present invention, the arc is 30°–60°.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: The greatest advantage of the present invention is its self-powered nature. This sensor does not require an external power supply, saving downhole space during installation. At the same time, this type of sensor also has a series of advantages such as low cost, simple structure, and high efficiency at low frequencies. It converts the longitudinal vibration of the drill string into the vibration of the vibration table and the reciprocating rolling of the roller. By utilizing the intermittent contact sensing between the vibration table and the end cap, and the friction sensing between the roller and different copper electrodes, the vibration frequency, vibration amplitude, and vibration acceleration parameters of the longitudinal vibration of the drill string can be reflected in real time through electrical signals. The present invention has a simple structure, high reliability, and is not prone to distortion. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of the present invention;

[0016] Figure 2 for Figure 1 The front view;

[0017] Figure 3 for Figure 1 Top view;

[0018] Figure 4 for Figure 2 AA sectional view.

[0019] In the diagram: 1. End cap; 2. Outer shell; 3. Screw; 4. Copper electrode layer and Kapton sensing layer; 5. Vibration table; 6. Roller; 7. Spring; 8. Sleeve; 9. Copper electrode; 10. Buffer bladder; 11. Copper electrode layer and silicone film sensing layer; 12. Moving rod. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Please see Figure 1-4This invention provides a technical solution: a self-powered vibration measurement sensor for coal mine drilling, comprising a housing 2 and an end cap 1, the housing 2 and the end cap 1 being sealed by screws 3; a vibration table 5 is disposed in the cavity in the middle of the housing 2; a copper electrode layer and a Kapton sensing layer 4 are disposed on the upper surface of the vibration table 5; a copper electrode layer and a silicone film sensing layer 11 are disposed on the lower side of the end cap 1; a buffer bladder 10 made of rubber is disposed between the end cap 1 and the copper electrode layer and the silicone film sensing layer 11, and the buffer bladder 10 is filled with buffer solution; the copper electrode layer and the Kapton sensing layer 4 are positioned corresponding to the copper electrode layer and the silicone film sensing layer 11; during the longitudinal vibration of the drill string, the vibration table 5 is driven to reciprocate up and down, so that the copper electrode layer and the Kapton sensing layer 4 are cyclically contacted and separated from the copper electrode layer and the silicone film sensing layer 11, thereby inducing electricity, and the frequency of the output voltage signal can reflect the vibration frequency of the drill string.

[0022] A sleeve 8 is installed at the bottom of the cavity in the middle of the outer shell 2. A movable rod 12 is fixedly installed on the lower surface of the vibration table 5. The movable rod 12 is embedded in the sleeve 8 and can reciprocate along the direction of the sleeve 8. The sleeve 8 can ensure that the vibration table 5 does not tilt during reciprocating vibration. A spring 7 is sleeved on the sleeve 8. The spring 7 is locked between the vibration table 5 and the inner bottom surface of the outer shell 2 to start the vibration of the vibration table 5. Rollers 6 of the same specification are symmetrically arranged around the vibration table 5. A layer of PTFE film is laid on the surface of the rollers 6. Multiple rows of copper electrodes 9 are symmetrically attached to the inner wall of the outer shell 2. The roller 6 is positioned between the vibration table 5 and the corresponding copper electrode 9. During vibration, the roller 6 reciprocates, and the PTFE film on the roller 6 contacts and rubs against the corresponding copper electrode 9 at different positions to generate an electric voltage signal. Each row of copper electrodes 9 has multiple pairs of copper electrodes. The width of each pair of copper electrodes is different, but the curvature is equal, ranging from 30° to 60°, preferably 40°. Since the width of each pair of electrodes is different, the output voltage value is also different. The amplitude can be reflected by the output voltage value, and the corresponding acceleration value can also be calculated by the time difference between the output signals between the electrodes.

[0023] During operation, as the vibration platform reciprocates up and down, the copper electrode layer and the silicone film sensing layer 11 cyclically contact and separate from the copper electrode layer and the Kapton sensing layer 4, thereby inducing electricity. The frequency of the output voltage signal can reflect the vibration frequency. At the same time, as the vibration platform vibrates up and down, the rollers 6 on both sides also roll and generate electricity through friction with the copper electrodes 9 attached to the inner wall. Since the width of each pair of copper electrodes 9 is different, the output voltage value is also different. Therefore, the amplitude can be reflected by the output voltage value here, and the acceleration value can also be calculated by the time difference of the output signal between the electrodes.

[0024] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A self-powered vibration measurement sensor for coal mine drilling, comprising a housing (2) and an end cap (1), wherein the housing (2) and the end cap (1) are connected and sealed by screws (3), characterized in that: A vibration table (5) is provided in the cavity in the middle of the outer shell (2). A copper electrode layer and a Kapton sensing layer (4) are provided on the upper surface of the vibration table (5). A copper electrode layer and a silicone film sensing layer (11) are provided on the lower side of the end cap (1). The copper electrode layer and the Kapton sensing layer (4) are positioned corresponding to the copper electrode layer and the silicone film sensing layer (11). During the longitudinal vibration of the drill string, the vibration table (5) is driven to move up and down reciprocally, so that the copper electrode layer and the Kapton sensing layer (4) are cyclically contacted and separated from the copper electrode layer and the silicone film sensing layer (11), thereby inducing electricity. The frequency of the output voltage signal can reflect the vibration frequency of the drill string. The vibrating table (5) is symmetrically surrounded by rollers (6) of the same specifications. A layer of PTFE film is laid on the surface of the rollers (6). Multiple rows of copper electrodes (9) are symmetrically attached to the inner wall of the outer shell (2). A buffer bladder (10) made of rubber is provided between the end cap (1) and the copper electrode layer and the silicone film sensing layer (11). The buffer bladder (10) is filled with buffer solution. The rollers (6) are stuck between the vibrating table (5) and the corresponding copper electrodes (9). During the vibration of the vibrating table (5), the rollers (6) reciprocate. The PTFE film on the rollers (6) contacts and rubs against the corresponding copper electrodes (9) at different positions to generate electricity and output the corresponding voltage signal. A sleeve (8) is provided at the bottom of the cavity in the middle of the outer shell (2), and a moving rod (12) is fixedly provided on the lower surface of the vibration table (5). The moving rod (12) is embedded in the sleeve (8) and can move back and forth along the direction of the sleeve (8). A spring (7) is fitted on the sleeve (8), and the spring (7) is locked between the vibration table (5) and the inner bottom surface of the outer shell (2) to start the vibration of the vibration table (5); Each row of copper electrodes (9) has multiple pairs of copper electrodes; each pair of copper electrodes has a different width but the same curvature. The arc is 30°–60°.

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