Preamplifier for marine single-channel seismic receiver cable

Abstract

This invention relates to a preamplifier for a single-channel marine seismic receiving cable. The preamplifier has a sealing plug at both ends of the cable insertion hole at the front end of the housing. The cable passes coaxially through the plug holes and is slidably sealed to the sealing plug. Each sealing plug has a pressure ring coaxially mounted on its large end face. The pressure ring is pressed into the conical bore section by a locking bolt, and the pressure ring does not contact the end face of the housing. The locking bolt is fixed to the housing wall, and a smooth cylindrical section slides with the pressure ring. An inner pressure ring abuts against the end face of a pressure plate via an elastic element. The pressure plate is located near the front end of the housing and is coaxially and integrally connected to the cable. There is a tensile movement range between the cable and the data interface of the circuit board, so that when the cable is towed by a ship, the pressure plate compresses the elastic element, further pressing the inner pressure ring against its corresponding inner sealing plug. This invention can significantly improve the preamplifier's sealing, vibration resistance, and the reliability of its connection to the cable.

Description

Technical Field

[0001] This invention relates to the field of marine seismic receiving cable technology, and more specifically to a preamplifier for a marine single-channel seismic receiving cable. Background Technology

[0002] Marine single-channel seismic exploration is one of the core technologies in marine geological surveys, oil and gas resource exploration, and other fields. As a key component of the seismic receiving cable, the preamplifier should be connected to the cable to better amplify the signal. Its working environment is relatively harsh, and it needs to withstand multiple tests such as seawater corrosion, seawater impact vibration, especially the tension fluctuation during towing, and the risk of seawater leakage. Its working stability and service life directly determine the quality of seismic exploration data acquisition and the continuity of exploration operations. In the existing technology, the preamplifier shell used for marine single-channel seismic receiving cables mostly adopts a single-layer structure. Even if some of the materials used are corrosion-resistant, it is difficult to achieve both corrosion resistance and shock and vibration resistance. During long-term immersion in the marine environment and towing operations, the shell is easily damaged by seawater corrosion, or the external impact and vibration are transmitted to the internal circuit board, causing damage to the circuit board and affecting the normal operation of the equipment. Regarding sealing performance, existing preamplifier cable hole sealing structures mostly use a single sealing element for fixed sealing. The fit clearance between the sealing element and the cable / cable hole is difficult to control precisely, and there is a lack of adaptive compensation mechanism for sealing performance. During towing operations, when the cable encounters obstacles in the sea and is subjected to a sudden strong pull, the sealing element is prone to relative displacement with the cable or cable hole, resulting in an increased sealing gap. Seawater can easily seep into the casing through the cable hole, damaging the internal circuit board and electronic components. However, if the sealing pressure of the sealing element is designed to withstand the normal high pressure parameter when encountering strong pulls from obstacles, the sealing element may age and deform due to long-term excessive compression, reducing sealing reliability and service life. In addition, the connection between the cable and the circuit board data interface in the existing device lacks an effective buffer and positioning structure. When the drag force fluctuates, the cable is prone to loosening or falling off due to rigid pulling, or even the cable itself may be broken, affecting the stability of signal transmission. The aforementioned technical deficiencies make it difficult for existing marine single-channel seismic receiver cable preamplifiers to meet the needs of actual exploration operations in terms of adaptability, reliability, and service life in harsh marine environments. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide a preamplifier for a marine single-channel seismic receiving cable, which can improve sealing reliability, shock and vibration resistance, and cable connection stability.

[0004] This invention is achieved through the following technical solution: A preamplifier for a single-channel marine seismic receiving cable includes a corrosion-resistant inner shell and an outer shell, with a buffer filler layer between the two shells. The front end of the shell has a cable-passing hole, and both ends of the cable-passing hole have a conical hole section. A sealing plug is embedded in each of the conical hole sections. The cable passes coaxially through the plug hole of the sealing plug and is slidably sealed to the sealing plug. Each sealing plug has a pressure ring coaxially arranged on its large end face. The pressure ring presses the sealing plug into the conical hole section through a locking bolt, and the pressure ring does not contact the end face of the outer shell, so that the pressure ring has an axial displacement to continue compressing the sealing plug. The locking bolt is fixed to the shell wall of the outer shell, and the part of it that protrudes from the shell wall is a smooth cylindrical section, which slides with the pressure ring. The inner pressure ring located inside the housing is in contact with the end face of a pressure plate through an elastic element. The pressure plate is located at the front end of the housing and is coaxially and integrally connected with the cable. There is a tensile movement between the cable and the data interface of the circuit board so that when the cable is towed by the ship, the pressure plate compresses the elastic element, thereby allowing the inner pressure ring to further press its corresponding inner sealing plug.

[0005] Furthermore, the sealing plug includes a coaxially integrally formed cylindrical portion and a conical portion, with the cylindrical portion located outside the conical bore section for coaxial sleeve connection with the pressure ring.

[0006] Furthermore, the elastic element is a disc spring, one end of which is coaxially connected to the end face of the inner pressure ring, and the other end is coaxially connected to the pressure plate. Under normal conditions, the pressure ring is in contact with the nut of the locking bolt. When the cable is dragged forward and the outer casing is moved, if the resistance exceeds the rated resistance, the cable slides forward axially in the cable hole, and the inner pressure ring further presses the inner sealing plug, causing the inner pressure ring to separate from the nut.

[0007] Furthermore, the locking bolt is welded or integrally fixed to the edge of the circular boss on the inner end face of the housing, and the cable hole is coaxially arranged with the circular boss.

[0008] Furthermore, a piston rod is fixed perpendicularly to the end face of the pressure plate near its edge. The piston ring of the piston rod is located in an annular pressure chamber fixedly installed inside the outer shell. The annular pressure chamber is filled with compressed gas. One end of the pressure pipe is fixedly connected to the end opposite to the pressure plate, and the other end of the pressure pipe is connected to the outer pressure ring. This allows the piston ring to further compress the compressed gas and push the outer pressure ring to further press its corresponding outer sealing plug when the pressure plate moves forward along the axial direction of the cable.

[0009] Furthermore, the outer pressure ring end face has a T-shaped sliding cavity; the end of the booster tube is located in the sliding cavity in a sealing fit and is axially elastically connected to the inner wall of the sliding cavity through a pressure-resistant spring, so that when the piston rod squeezes and compresses the gas, the outer pressure ring moves axially toward the outer sealing plug relative to the end of the booster tube.

[0010] Furthermore, a positioning component is fixed at the front end inside the housing. The positioning component is used to fix the position of the cable near the circuit board interface. The portion of the cable between the positioning component and the pressure plate is partially freely bent.

[0011] Furthermore, the positioning component includes a positioning ring, on which a plurality of studs are installed radially. One end of each stud is fixed with a driven gear, and the other end is rotatably connected to the inner side of the outer surface of the tube segment. The driven gear meshes with an end face gear, which is coaxially and rotatably mounted on the positioning ring so that when rotated, all the studs move synchronously, causing the tube segment to hug the cable and fix it to the end face of the positioning ring.

[0012] Furthermore, the end gear is coaxially and integrally fixed on the end face of a locking sleeve. The locking sleeve is threaded onto the cylindrical boss at the end of the positioning ring and is in contact with the stepped surface of the cylindrical boss by a fastening spring. The outer surface of the locking sleeve has a regular hexagonal structure.

[0013] Furthermore, the portion of the cable located within the cable threading hole and positioning assembly is coaxially fitted with a rubber sheath; the outer shell is cylindrical, with rounded corners on its end faces.

[0014] The beneficial effects of this invention are as follows: This invention relates to a preamplifier for a single-channel marine seismic receiving cable. Addressing the technical shortcomings of existing preamplifiers for single-channel marine seismic receiving cables in terms of adaptability to harsh marine environments, sealing reliability, shock and vibration resistance, and cable connection stability, the corresponding structural principles of this invention are explained in detail below: 1. Excellent corrosion resistance and shock and vibration resistance, suitable for harsh marine environments: The outer shell adopts a double-shell structure, with both the inner and outer shells having corrosion resistance, which can effectively resist long-term seawater immersion corrosion and extend the service life of the device; the gap between the inner and outer shells is filled with a buffer filler layer, which can effectively absorb external impacts and vibrations, weaken the impact force transmitted to the inner shell, thereby reliably protecting the internal circuit board from damage and ensuring the stable operation of the device in towing operations and complex seabed environments.

[0015] 2. Adaptive and Adjustable Sealing Performance, High Leakage Reliability: The cable insertion hole employs a double conical hole section with double sealing plugs at both ends. The sealing plugs utilize a conical structure adapted to the conical hole section, forming a sliding seal with the cable through elastic compression, resulting in a good initial sealing effect. Simultaneously, each sealing plug is equipped with a pressure ring and a locking bolt. The pressure ring retains axial displacement for further compression of the sealing plug. When the cable is subjected to strong pulling, it can drive the pressure ring to further compress the sealing plug, ensuring a tighter seal between the plug and the cable, thus achieving adaptive improvement in sealing performance. Furthermore, through the linkage structure of the pressure plate, elastic element, piston rod, annular pressure chamber, and pressure pipe, when the cable is pulled, the inner pressure ring can simultaneously compress the inner sealing plug, and the outer pressure ring can simultaneously compress the outer sealing plug, achieving bidirectional adaptive dynamic sealing at both ends of the cable insertion hole. This not only copes with abnormal changes in pressure during towing but also avoids aging and deformation caused by excessive compression of the sealing plug under normal conditions, balancing sealing reliability and service life. 3. Stable cable connection with excellent anti-drop and anti-breakage performance: The internal housing is equipped with a positioning component. Through the coordinated action of the positioning ring, stud, tube, driven gear, end face gear, and locking sleeve, the cable can be reliably fixed near the circuit board interface, preventing the cable from loosening or even detaching from the circuit board interface due to tension, thus ensuring the stability of signal transmission. The cable section between the positioning component and the pressure plate is designed to be partially free-bending, and a small amount of tensile movement is reserved between the cable and the circuit board data interface. This provides room to avoid axial tension generated during cable dragging, allowing the cable to slip slightly under a set tension, effectively preventing cable breakage due to rigid tension, and further improving the reliability of the cable connection. In summary, the present invention has a scientific and reasonable structural design. Through multi-structure collaborative optimization, it comprehensively improves the core performance of the preamplifier, such as corrosion resistance, shock and vibration resistance, sealing reliability, and cable connection stability. It can perfectly adapt to the harsh operating environment of marine single-channel seismic exploration, significantly extend the service life of the device, and ensure the continuity and accuracy of seismic exploration data acquisition. It has extremely high practical value and promotion significance.

[0016] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0017] Figure 1 This is a partial cross-sectional view of one of the preamplifiers for a single-channel marine seismic receiving cable according to the present invention; Figure 2 This is a structural diagram of the central part of the front end of a preamplifier used in a single-channel marine seismic receiving cable. Figure 3 for Figure 1 Sectional view at point A in the middle; Figure 4 for Figure 3 Enlarged view of point C in the middle; Figure 5 Position the main view of the component; Figure 6 This is an axial sectional view of the positioning component; Figure 7 The right view of the positioning component; Figure 8 A schematic diagram of a six-segment circular array around a cable; Figure 9 This is a schematic diagram of the cross-section when the outer shell has a cylindrical structure.

[0018] In the diagram: 1. Outer shell 101, 102. Buffer packing layer 102, 103. Inner shell 103, 2. Circuit board 2, 3. Cable 3, 4. Inner sealing plug 4, 401. Conical part 402, 402. Locking bolt 5, 501. Smooth column section 502, 502. Disc spring 6, 7. Pressure plate 7, Piston rod 8, Piston ring 9, Pressure boosting tube 10, Inner pressure ring 11, Outer pressure ring 12, Slide cavity 1201, Pressure-resistant spring 13, Positioning ring 14, 1401. 15. Stud 15, Driven gear 16, Tube segment 17, End face gear 18, Locking sleeve 19, Fastening spring 20, Outer sealing plug 21, 22. Annular pressure boosting chamber 22. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0020] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0021] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0022] Please see Figures 1-3This invention provides a technical solution: the preamplifier for a single-channel marine seismic receiving cable in this embodiment, such as... Figure 1 The system mainly includes a housing 1 for mounting the circuit board 2. The housing 1 adopts a double-layer shell structure, with both the inner shell 103 and the outer shell 101 possessing corrosion resistance to adapt to the harsh corrosive environment of the ocean. A buffer filler layer 102 fills the gap between the inner shell 103 and the outer shell 101. This buffer filler layer 102 effectively absorbs external impacts and vibrations, weakening the impact force transmitted to the inner shell 103, thereby protecting the internal circuit board 2 from damage. A cable-passing hole is provided at the front end of the housing 1 for the cable 3 to pass through. Both ends of the cable-passing hole are provided with conical sections, each containing a sealing plug: an outer sealing plug 21 and an inner sealing plug 4, located respectively within the outer and inner surfaces of the end of the housing 1. The sealing plugs adopt a conical structure adapted to the conical sections. The cable 3 passes coaxially through the plug hole in the center of the sealing plug, and a sliding seal is formed between the cable 3 and the sealing plug due to strong elastic compression contact, preventing seawater from seeping into the interior of the housing 1 through the cable-passing hole. Meanwhile, a pressure ring is coaxially assembled on the large end face of each sealing plug, namely the inner pressure ring 11 and the outer pressure ring 12, which are used to compress the inner sealing plug 4 and the outer sealing plug 21, respectively. Each pressure ring presses the sealing plug into the conical hole section through several locking bolts 5. After assembly, the pressure ring does not contact the end face of the outer shell 1, so that the pressure ring retains the axial displacement to continue compressing the sealing plug, providing space for subsequent compensation of sealing performance. The main purpose is that when the cable 3 is pulled forcefully, the sealing plug is squeezed more tightly, so that it wraps more tightly with the cable 3, resulting in better sealing performance and improved sealing and connection reliability. Figure 3As shown, the locking bolt 5 is fixedly installed on the shell wall of the outer casing 1. The part of the locking bolt 5 protruding from the shell wall of the outer casing 1 is a smooth cylindrical section 501. A matching through hole is opened on the pressure ring. The smooth cylindrical section 501 and the through hole of the pressure ring form a sliding fit to ensure that the pressure ring moves smoothly without jamming in the axial direction. The inner pressure ring 11 located inside the outer casing 1 (i.e., the pressure ring near the inner side of the outer casing 1) is in contact with the end face of a pressure plate 7 through an elastic element. The pressure plate 7 is located inside the outer casing 1 near the front end, and the pressure plate 7 is coaxial with the cable 3 and integrally connected. A tensile movement amount is reserved between the cable 3 and the data interface on the circuit board 2. For example, the corresponding part of the cable 3 is slightly bent freely to avoid the cable 3 from falling off the data interface when pulled. On the other hand, it provides a prerequisite for the cable 3 to slide slightly under the set tension in the wire hole, so as to prevent the cable 3 from being pulled off. During use, when the ship tows the cable 3 forward, the cable 3 and the outer shell 1 generally move together. However, when encountering obstacles on the seabed or other factors that cause the pulling to be obstructed, the tension on the cable 3 will increase significantly. At this time, it will drive the pressure plate 7 to move forward, that is, the cable 3 will have a small displacement or slippage in the cable hole, causing the pressure plate 7 to compress the elastic element, which in turn pushes the inner pressure ring 11 to further tighten its corresponding inner sealing plug 4, automatically improving the sealing effect and coping with the abnormal changes in pressure during towing. At the same time, it is also to avoid the sealing plug and the corresponding part of the cable 3 being in an excessively squeezed state under unnecessary pulling conditions, which would affect their service life and long-term reliability. The sealing firmness will only be further automatically improved under strong pulling force. In this embodiment, as Figure 3 As shown, the sealing plug adopts a coaxial integral molding structure, specifically including a cylindrical part 402 and a conical part 401. The shape of the conical part 401 is adapted to the conical hole sections at both ends of the cable hole. During assembly, the conical part 401 is embedded in the conical hole section, while the cylindrical part 402 is located outside the conical hole section. The outer diameter of the cylindrical part 402 matches the inner hole of the pressure ring, allowing the pressure ring to be coaxially sleeved on the cylindrical part 402. Through the pressing action of the pressure ring, the conical part 401 of the sealing plug can be tightly fitted with the conical hole section, further ensuring the sealing reliability. In this embodiment, as Figure 3As mentioned above, the elastic element can be a disc spring 6 with large elastic force and relatively small size. The disc spring 6 has good elastic restoring performance and compressive strength. One end of the disc spring 6 is coaxially fixedly connected to the end face of the inner pressure ring 11, and the other end is coaxially fixedly connected to the end face of the pressure plate 7. In the assembled state (normal state), the pressure ring abuts against the nut 502 of the locking bolt 5, allowing the locking bolt 5 to maintain an initial compression sealing force on the sealing plug through the pressure ring. At this time, the disc spring 6 can be in a slightly compressed state or without compression. When it is slightly compressed, it can provide basic clamping force for the sealing plug together with the locking bolt 5. When the cable 3 is dragged forward and the housing 1 is moved, if the resistance exceeds the rated resistance, the cable 3 will slide forward axially relative to the housing 1 in the cable hole. The cable 3 drives the pressure plate 7 to move forward synchronously. The pressure plate 7 further compresses the disc spring 6. The elastic force of the disc spring 6 pushes the inner pressure ring 11 to further press the inner sealing plug 4. At this time, the inner pressure ring 11 separates from the nut 502 of the locking bolt 5, that is, the axial pressure of the sealing plug increases. This structure realizes the adaptive compensation of sealing pressure, ensuring the sealing effect under resistance fluctuation. When the external resistance returns to the normal state, the disc spring 6 resets, which can release a certain pressure on the sealing plug and allow the sealing plug to return to the sealing state under normal working conditions. like Figure 3 As shown, in this embodiment, a circular boss is provided on the inner end face of the outer shell 1 (the inner end face near the cable hole). It can be integrally formed with the outer shell 1. The cable hole and the circular boss are coaxially arranged to ensure the coaxiality when the cable 3 passes through. The locking bolts 5 are fixed to the edge of the circular boss by welding or integral forming. Multiple locking bolts 5 are evenly distributed along the circumference of the circular boss. This fixing method improves the connection strength of the locking bolts 5 and prevents the locking bolts 5 from loosening or falling off due to vibration and tension during marine towing, thus ensuring the compression stability of the pressure ring on the sealing plug. In this embodiment, as Figure 3As shown, a piston rod 8 is vertically fixed on the edge end face of the pressure plate 7. A piston ring 9 is provided at the end of the piston rod 8 away from the pressure plate 7. The piston ring 9 is assembled in an annular pressure chamber 22, which is fixedly installed inside the outer shell 1. The annular pressure chamber 22 is filled with compressed gas that has been compressed to a certain degree and can still be compressed further. The compressed gas is preferably an inert gas. One end of a pressure boosting pipe 10 is fixedly connected to the end of the annular pressure chamber 22 away from the pressure plate 7. The other end of the pressure boosting pipe 10 is connected to the outer pressure ring 12 (i.e., the pressure ring near the outer side of the outer shell 1). When the cable 3 is dragged by the pressure plate 7 and moves forward axially, the pressure plate 7 drives the piston rod 8 to move forward synchronously. The piston ring 9 on the piston rod 8 further compresses the compressed gas in the annular pressure chamber 22, causing the gas pressure in the pressure chamber to increase further. The high-pressure gas is transmitted to the outer pressure ring 12 through the pressure pipe 10, pushing the outer pressure ring 12 to further press its corresponding outer sealing plug 21, realizing adaptive pressurization of the outer end seal, and adaptively improving the sealing performance of the outer sealing plug 21. Thus, in this device, both ends of the wire hole are adaptively and dynamically sealed, and the sealing performance is adaptively adjusted according to the working conditions. In specific manufacturing, such as Figure 4 A T-shaped sliding cavity 1201 is formed on the end face of the outer pressure ring 12, with the opening of the sliding cavity 1201 facing the side of the booster tube 10. The end of the booster tube 10 is also T-shaped and is slidably and sealingly installed in the sliding cavity 1201. The end of the booster tube 10 and the inner wall of the sliding cavity 1201 are connected by a pressure-resistant spring 13 as shown in the figure to achieve an axial elastic seal connection, maintaining the reliability and sealing of the connection between the booster tube 10 and the outer pressure ring 12. The pressure-resistant spring 13 can withstand the reaction force generated when the outer pressure ring 12 is squeezed and close to the outer sealing plug 21, allowing gas to pass through the fixed booster tube 10 and press against the end face of the outer pressure ring 12 as the driving force to drive the outer pressure ring 12, thereby further enhancing the sealing of the outer sealing plug 21 and simultaneously achieving a sliding seal between the booster tube 10 and the outer pressure ring 12. The structure is simple and ingenious.

[0023] In this embodiment, as Figure 1 , Figures 5-7 As shown, a positioning component is also fixedly installed inside the housing 1 near the front end. This positioning component is used to fix the position of the cable 3 near the interface of the circuit board 2, that is, to fix the position of the cable 3 near the aforementioned data interface, so as to prevent the cable 3 from loosening or even detaching from the interface of the circuit board 2 due to tension, thus ensuring the stability of signal transmission. The portion of the cable 3 between the positioning component and the pressure plate 7 is set to a partially free-bending shape, which only requires slight bending. This free-bending structure allows for the axial stretching of the cable 3 during dragging, preventing the cable 3 from being rigidly pulled and damaged when it encounters an accidental strong resistance when it is normally taut. It also provides clearance for the axial movement of the pressure plate 7. The positioning component in this embodiment includes a positioning ring 14, which is fixedly installed inside the housing 1. Figures 5-6 As shown, the locating ring 14 is radially threaded with several studs 15. The number of studs 15 is set according to the positioning requirements; for example, it can also be set as follows: Figure 8 The six studs shown ensure even clamping and securing of cable 3. Each stud 15 has a driven gear 16 fixedly connected to one end, and the other end connected via... Figure 6 The rotating fit shown is connected to the inner side of the outer surface of the tube 17. The inner surface of the tube 17 is adapted to the shape of the cable 3 for contact with the surface of the cable 3. All driven gears 16 mesh with a face gear 18, which is coaxially mounted on the positioning ring 14 via bearings. When the face gear 18 rotates, it drives all driven gears 16 to rotate synchronously. The driven gears 16 drive the corresponding studs 15 to move radially synchronously along the positioning ring 14. The studs 15 push the tube 17 toward the cable 3, and finally, the multiple tubes 17 hold the cable 3 tightly and fix it to the end face of the positioning ring 14, achieving reliable positioning of the cable 3. In addition, the above positioning component can also be used on the pressure plate 7, so that the pressure plate 7 is fixed in the corresponding position of the cable 3 in this way. In this embodiment, as Figures 5-6 The end face gear 18 is coaxially and integrally fixed to the end face of a locking sleeve 19. The locking sleeve 19 is threaded onto the cylindrical boss 1401 at the end of the positioning ring 14. The cylindrical boss 1401 has a stepped surface and threads on its side. A fastening spring 20 is connected between the locking sleeve 19 and the stepped surface of the cylindrical boss 1401, providing preload to the locking sleeve 19 to prevent it from loosening during vibration. The outer surface of the locking sleeve 19 is designed as a regular hexagon, which facilitates rotation of the locking sleeve 19 using tools such as wrenches. Rotating the locking sleeve 19 drives the end face gear 18 to rotate synchronously, thereby realizing the synchronous movement of the stud 15 and the clamping or loosening of the cable 3 by the tube 17. The operation is convenient and the fixation is reliable. In this embodiment, the portion of cable 3 located inside the cable insertion hole and the positioning component is fitted with a rubber sheath (not shown in the figure) on the outer coaxial sleeve. The rubber sheath has good flexibility and wear resistance, protecting cable 3 and preventing damage caused by friction between cable 3 and the inner wall of the cable insertion hole and the internal structure of the positioning component. It also further improves the sealing performance at the cable insertion hole. During manufacturing, the outer shell 1 is as follows: Figure 9The device can be configured as a cylindrical structure, which facilitates towing in a marine environment and reduces water resistance. The edges of the outer shell 1 are rounded to prevent damage from impacts. To ensure the device remains in a relatively stable position, the inner shell 103 can be made into a semi-cylindrical structure, allowing the amplifier to slide smoothly without obstructions. Figure 9 The posture shown is shifted forward.

[0024] In the above description of the present invention, it should be noted that the terms "one side," "the other side," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the invention is conventionally placed during use. These terms are used only for the convenience of describing the present invention and for 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 the present invention. Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0025] Furthermore, terms such as "identical" do not imply that components must be absolutely identical; minor differences are permissible. The term "perpendicular" simply means that the positional relationship between components is more perpendicular than "parallel," not that the structure must be perfectly perpendicular; a slight tilt is acceptable.

[0026] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A preamplifier for a marine single-channel seismic receiving cable, comprising a housing (1) for mounting a circuit board (2), characterized in that: The outer shell (1) comprises a corrosion-resistant inner shell (103) and an outer shell (101), and a buffer filler layer (102) is filled between the two shells, the front end of the outer shell (1) has a cable passing hole, both ends of the cable passing hole have a conical hole section, a sealing plug is embedded in each conical hole section, a cable (3) coaxially passes through the plug hole of the sealing plug and is in sliding sealing connection with the sealing plug; A compression ring is coaxially arranged on the large end surface of each sealing plug, the compression ring is pressed into the conical hole section by a locking bolt (5), and the compression ring does not contact the end surface of the outer shell (1), so that the compression ring has an axial displacement amount for further compressing the sealing plug, the locking bolt (5) is fixed on the shell wall of the outer shell (1), and the exposed shell wall of the outer shell (1) is a smooth column section (501), and the smooth column section (501) is in sliding fit with the compression ring; An inner compression ring (11) located in the outer shell (1) is in abutting contact with the end surface of a pressure plate (7) through an elastic element, the pressure plate (7) is located at the front end in the outer shell (1), and the pressure plate (7) is coaxially and integrally connected with the cable (3), and the cable (3) has a stretching displacement amount with the data interface of the circuit board (2), so that when the cable (3) is pulled forward by a ship, the inner compression ring (11) is further compressed to the corresponding inner sealing plug (4) by the compression of the pressure plate (7) and the elastic element.

2. A preamplifier for a marine single-channel seismic streamer according to claim 1, characterized in that: The sealing plug comprises a coaxially integrated cylindrical part (402) and a conical part (401), and the cylindrical part (402) is located outside the conical hole section for coaxial sleeving of the compression ring.

3. A preamplifier for a marine single-channel seismic streamer according to claim 2, characterized in that: The elastic element is a disc spring (6), one end of which is coaxially connected with the end surface of the inner compression ring (11), the other end is coaxially connected with the pressure plate (7), and the compression ring is in abutting contact with the nut (502) of the locking bolt (5) in a normal state, when the cable (3) is pulled forward to move the outer shell (1) and encounters a force exceeding the rated resistance, the cable (3) axially slides forward in the cable passing hole, the inner compression ring (11) further compresses the inner sealing plug (4) to separate the inner compression ring (11) from the nut (502).

4. A preamplifier for a marine single-channel seismic streamer according to claim 1, characterized in that: The locking bolt (5) is welded or integrally fixed to the edge of the circular boss of the end surface in the outer shell (1), and the cable passing hole is coaxially arranged with the circular boss.

5. A preamplifier for a marine single-channel seismic streamer according to claim 1, characterized in that: The end surface of the pressure plate (7) is also vertically fixed with a piston rod (8), the piston ring (9) of the piston rod (8) is located in an annular pressure chamber (22) fixedly installed in the outer shell (1), the annular pressure chamber (22) is filled with compressed gas, one end of the pressure plate (7) is fixedly connected with one end of a pressure pipe (10), the other end of the pressure pipe (10) is connected with an outer compression ring (12), so that when the pressure plate (7) axially moves forward, the piston ring (9) further presses the compressed gas to push the outer compression ring (12) to further compress the corresponding outer sealing plug (21).

6. A preamplifier for a marine single-channel seismic streamer according to claim 5, characterized in that: The outer pressure ring (12) has a T-shaped sliding cavity (1201) on its end face; the end of the booster tube (10) is located in the sliding cavity (1201) in a sealed fit, and is axially elastically connected to the inner wall of the sliding cavity (1201) by a pressure-resistant spring (13), so that when the piston rod (8) squeezes and compresses the gas, the outer pressure ring (12) moves axially toward the outer sealing plug (21) relative to the end of the booster tube (10).

7. A preamplifier for a marine single-channel seismic streamer according to claim 1, characterized in that: A positioning component is also fixed at the front end of the housing (1). The positioning component is used to fix the position of the cable (3) near the interface of the circuit board (2). The part of the cable (3) between the positioning component and the pressure plate (7) is partially free-bent.

8. A preamplifier for a marine single-channel seismic streamer according to claim 7, characterized in that: The positioning assembly includes a positioning ring (14), and a plurality of studs (15) are installed radially on the positioning ring (14). One end of the stud (15) is fixed with a driven gear (16), and the other end is rotatably connected to the inner side of the outer surface of the tube sheet (17). The driven gear (16) meshes with an end face gear (18), and the end face gear (18) is coaxially rotatably mounted on the positioning ring (14) so ​​that when rotating, all the studs (15) move synchronously, causing the tube sheet (17) to hug the cable (3) and fix it on the end face of the positioning ring (14).

9. A preamplifier for a marine single-channel seismic streamer according to claim 8, characterized in that: The end face gear (18) is coaxially and integrally fixed on the end face of a locking sleeve (19). The locking sleeve (19) is threadedly fitted onto the cylindrical boss (1401) at the end of the positioning ring (14), and is in contact with the stepped surface of the cylindrical boss (1401) through a fastening spring (20). The outer surface of the locking sleeve (19) is a regular hexagonal structure.

10. A preamplifier for a marine single-channel seismic streamer according to claim 7, characterized in that: The portion of the cable (3) located within the cable hole and positioning assembly is fitted with a rubber sheath on the outside; the outer shell (1) is cylindrical with rounded corners on its end face.

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