Gravity sampling and geothermal gradient measuring device and measuring method

Abstract

The present application relates to the technical field of in-situ acquisition of seabed, in particular to a new gravity sampling and geothermal gradient measuring device and measuring method. The measuring device comprises: an impact unit, including an outer cylinder and a transmission cylinder, the transmission cylinder is located on the annular inner side of the outer cylinder, and the transmission cylinder rotates along the annular inner surface of the outer cylinder, an impact mechanism is arranged in the outer cylinder, and the transmission cylinder drives the impact mechanism to generate a downward impact force on the probe rod unit during rotation; a probe rod unit, fixedly connected with the bottom of the impact unit, comprising a probe rod and a plurality of temperature sensing units arranged on the probe rod. It can realize large-depth penetration of the probe, and complete in-situ temperature acquisition and in-situ sample collection during continuous downward penetration.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of in-situ acquisition of seabed, in particular to a new gravity sampling and geothermal gradient measuring device and measuring method. BACKGROUND

[0002] Seafloor heat flow data is of great significance to the research of plate tectonics dynamics, the thermal state of the earth interior, oceanic lithosphere and ocean basin evolution, continental margin formation process, plate subduction, and seabed resources.

[0003] The current seafloor heat flow probe technology is only suitable for heat flow measurement of soft seabed rich in sediments, and is not suitable for hard seabed and bedrock seabed. However, in fact, there is a considerable amount of bedrock seabed in the mid-ocean ridge and subduction zone seabed area, and its active thermal activity is a field worthy of study. Although the current borehole heat flow detection technology can be used for heat flow measurement of hard seabed and even bedrock seabed, it requires additional technical complex drilling equipment and measuring equipment such as a drilling ship, and the cost of obtaining heat flow data is expensive and inefficient, which is not conducive to large-scale geothermal survey.

[0004] In addition, there are two problems in the process of marine geothermal measurement operation. One is that the temperature measuring probe of the existing technology is prone to impact during lowering, which may cause damage to the probe. The second is that the existing gravity sampler cannot effectively penetrate the hard sandstone basement environment, resulting in a decrease in the effective length of the sample and the lack of temperature probe measurement data. SUMMARY

[0005] The purpose of the present application is to overcome the above-mentioned defects of the prior art, and to provide a new gravity sampling and geothermal gradient measuring device and measuring method, which can realize deep penetration of the probe and complete in-situ temperature acquisition and in-situ sample collection during continuous downward penetration.

[0006] The technical scheme of the present application is as follows: a new gravity sampling and geothermal gradient measuring device, comprising:

[0007] The impact unit comprises an outer cylinder and a transmission cylinder, the transmission cylinder is located on the inner side of the outer cylinder in a ring shape, and the transmission cylinder rotates along the inner surface of the outer cylinder in a ring shape. An impact mechanism is arranged in the outer cylinder, and the transmission cylinder drives the impact mechanism to generate a downward impact force on the probe rod unit during rotation.

[0008] The probe rod unit is fixedly connected to the bottom of the impact unit, and comprises a probe rod and a plurality of temperature sensing units arranged on the probe rod.

[0009] In the present application, the top of the outer cylinder is fixedly provided with a cover plate, the center of the cover plate is provided with a fixed column, the top end of the fixed column is located outside the outer cylinder and connected with the composite cable, and the bottom end of the fixed column is located inside the outer cylinder and connected with the sliding cylinder.

[0010] The annular outer side sliding sleeve of the outer cylinder is provided with a plurality of counterweight rings arranged at intervals in the axial direction, the counterweight rings are fixedly connected through connecting rods, and the counterweight rings are arranged on the bottom plate of the outer cylinder.

[0011] The bottom of the outer cylinder is fixedly connected with the probe rod unit, and the center of the top surface of the bottom of the outer cylinder is fixedly provided with a supporting column.

[0012] The annular inner side wall of the transmission cylinder is fixedly provided with a gear ring, a plurality of gears are correspondingly arranged in the outer cylinder, the gears are connected with the cover plate through a driving motor, and the gears and the gear ring are meshed with each other.

[0013] An upper stop ring is arranged above the transmission cylinder, a lower stop ring is arranged below the transmission cylinder, and the transmission cylinder is located between the upper stop ring and the lower stop ring, and the upper stop ring and the lower stop ring are fixedly connected with the outer cylinder.

[0014] The impact mechanism comprises:

[0015] The lead block is slidingly arranged in the sliding cylinder;

[0016] The end face cam is connected with the transmission cylinder at the annular outer side, and the upper surface thereof is a curved surface, and the curved surface is provided with smooth convex points;

[0017] A plurality of pull rod assemblies are arranged, the pull rod assembly comprises a support arranged in the horizontal direction, a pull rod arranged in the vertical direction, and a connecting rod rotationally connected with the outer cylinder, one end of the support is provided with a roller, the roller is in contact with the upper surface of the end face cam, the other end of the support is located below the lead block and is hingedly connected with the upper end of the pull rod, the lower end of the pull rod is hingedly connected with one end of the connecting rod, the other end of the connecting rod is hingedly connected with the outer cylinder, and the connecting ends of the pull rod and the connecting rod are located above the supporting column.

[0018] A plurality of oil grooves arranged in the axial direction are arranged at the inner surface of the sliding cylinder, and lubricating oil is arranged in the oil grooves.

[0019] The annular outer side of the end face cam is fixedly provided with an end face cam flange outer ring, and the transmission cylinder and the end face cam flange outer ring are connected through a pin shaft.

[0020] A plurality of pull rod assemblies are uniformly and intervaliy arranged in the circumferential direction of the transmission cylinder;

[0021] A plurality of support seats are fixedly arranged at the annular inner side of the outer cylinder, the support seats are connected through a support ring, and one end of the connecting rod is hingedly connected with the support ring.

[0022] A plurality of arc-shaped grooves are arranged at intervals in the axial direction on the probe rod unit, and a temperature sensing unit is arranged in the arc-shaped grooves;

[0023] The temperature sensing unit comprises a temperature sensor and a temperature measuring probe, the temperature measuring probe is connected with the temperature sensor, and the temperature sensor is fixedly connected with the probe rod through a fixing support;

[0024] The probe center is provided with a POM pipe.

[0025] The application further discloses a method for measuring the novel gravity sampling and geothermal gradient measuring device.

[0026] S1, after the device is put into water, the device is quickly inserted into the seabed under the action of gravity;

[0027] S2, after the device is inserted into the seabed sediment, the transmission cylinder is rotated, and in the rotating process, the impact mechanism continuously generates downward impact force on the probe unit, and through the impact force, the downward drilling of the device is realized;

[0028] S3, after the device is drilled to the expected depth, the impact mechanism stops acting, the process of downward drilling of the probe realizes sample collection, and the temperature gradient is collected through the temperature sensing unit.

[0029] In the step S2, the device is powered by the composite cable, the gear connected with the motor is driven to rotate by the motor, the gear ring and the transmission cylinder fixedly connected with the gear ring are driven to rotate through the mutual meshing between the gear and the gear ring;

[0030] The transmission cylinder is rotated, the pin shaft connection between the end face cam flange end outer ring and the transmission cylinder makes the transmission cylinder drive the end face cam to synchronously rotate;

[0031] In the rotating process of the end face cam, the convex points on the end face cam periodically lift the roller, the bracket connected with the roller also moves upward, in the process of upward movement of the bracket, the lead block is lifted and slides into the sliding cylinder, at the same time, the bracket drives the connecting rod to rotate upward through the pull rod, and the connecting end of the pull rod and the connecting rod is away from the upper surface of the supporting column;

[0032] The end face cam continues to rotate, the convex points on the end face cam are away from the roller, at this time, the roller descends, the bracket connected with the roller also moves downward, the bracket drives the connecting rod to rotate downward through the pull rod, and the lead block moves downward under the action of gravity, and downward pressure is applied to the bracket, when the connecting end of the connecting rod and the pull rod moves downward to contact and collide with the supporting column, downward impact force is applied to the supporting column through the pressure generated by the lead block;

[0033] With the rotation of the end face cam, the lead block periodically reciprocates in the vertical direction, and in the process of periodic downward movement of the lead block, the downward pressure of the lead block is sequentially transmitted to the supporting column through the connecting end of the connecting rod and the pull rod in the plurality of connecting rod assemblies, and the downward impact force is continuously applied to the probe unit;

[0034] In the process of downward movement of the probe unit, the sediment enters the POM pipe, and sample collection is realized.

[0035] The beneficial effects of the present application are:

[0036] (1) The device can rely on the gravity of the lead block configured by itself to continuously apply downward impact force to the probe rod, and can realize large depth penetration of the probe, and in the process of continuous downward penetration of the probe rod, in-situ temperature acquisition and in-situ sample collection are completed at the same time;

[0037] (2) In the probe rod unit of the device, the temperature sensing unit is arranged in the arc-shaped groove on the probe rod, which can effectively avoid damage of the temperature sensor caused by friction of the surrounding deposited bottom layer, and ensure the integrity of the in-situ temperature acquisition data of the probe rod;

[0038] (3) The device has small volume and compact structure, and through the setting of the curve of the working surface of the end face cam and the number of connecting rod assemblies, the impact frequency of the probe rod unit can be accurately controlled. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 is a schematic diagram of the three-dimensional structure of the device of the present application;

[0040] Figure 2 is a schematic diagram of the front structure of the device of the present application;

[0041] Figure 3 is a schematic diagram of the first cross-sectional structure of the impact unit;

[0042] Figure 4 is a schematic diagram of the second cross-sectional structure of the impact unit;

[0043] Figure 5 is a schematic diagram of the third cross-sectional structure of the impact unit;

[0044] Figure 6 is a schematic diagram of the inner surface of the slide cylinder;

[0045] Figure 7 is a schematic diagram of the structure of the end face cam;

[0046] Figure 8 is a schematic diagram of the structure of the connection between the end face cam and the transmission cylinder;

[0047] Figure 9 is a schematic diagram of the structure of the connection between the temperature sensing unit and the probe rod;

[0048] Figure 10 is a schematic diagram of the structure of the probe rod.

[0049] In the figure: 1 impact unit; 2 probe rod unit; 3 counterweight; 4 probe rod; 5 temperature sensing unit; 6 composite cable; 7 connecting column; 8 cover plate; 9 driving motor; 10 gear; 11 lead block; 12 sliding cylinder; 13 end face cam; 14 counterweight ring; 15 working surface; 16 lower blocking ring; 17 transmission cylinder; 18 upper blocking ring; 19 outer cylinder; 20 gear ring; 21 support; 22 roller; 23 pull rod; 24 connecting rod; 25 support ring; 26 support seat; 27 bearing column; 28 connecting rod; 29 oil groove; 30 end face cam flange outer ring; 31 pin shaft; 32 temperature sensor; 33 temperature measuring probe; 34 fixed support; 35 POM tube; 36 arc-shaped groove; 37 bottom plate. DETAILED DESCRIPTION

[0050] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0051] In the following description, specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be practiced in a variety of ways beyond those described herein without departing from the spirit of the present application, which would be understood by one skilled in the art. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0052] As shown in Figure 1 and Figure 2 A new gravity sampling and geothermal gradient measuring device according to the present application includes an impact unit 1 and a probe rod unit 2. The impact unit 1 is located above the probe rod unit 2, and the bottom of the impact unit 1 is fixedly connected to the top of the probe rod unit 2. The top surface of the impact unit 1 is provided with a composite cable 6. Through the composite cable, the connection between the measuring device and the work ship is achieved.

[0053] As shown in Figure 3 and Figure 4As shown, the impact unit comprises an outer cylinder 19, the top of the outer cylinder 19 is fixed with a cover plate 8, the circumferential outer side of the outer cylinder 19 is provided with a counterweight 3, the counterweight 3 is arranged on a bottom plate 37, the bottom plate 37 is fixed on the circumferential outer side of the outer cylinder 19. The counterweight 3 in this embodiment is a plurality of counterweight rings 14 arranged along the axial direction of the outer cylinder and located on the circumferential outer side of the outer cylinder, the plurality of counterweight rings 14 are fixedly connected through connecting rods 28, and each counterweight ring 14 is fixedly connected with the connecting rod 28. A cylindrical cavity is arranged in the outer cylinder 19, and an impact mechanism is arranged in the cavity. The bottom of the outer cylinder is fixedly connected with the probe rod unit, and the top surface of the bottom of the outer cylinder 19 is fixedly provided with a supporting column 27, which is in a protruding shape. During the operation of the impact mechanism, the impact mechanism continuously applies downward impact force to the supporting column, and the supporting column transmits the impact force to the probe rod unit, so that the probe rod unit continuously drills downward. In this embodiment, the supporting column 27 is in a cylindrical shape and located in the outer cylinder, and is fixed at the center position of the top surface of the bottom of the outer cylinder.

[0054] The annular inner side of the outer cylinder 19 is provided with a transmission cylinder 17, and in this embodiment, the outer cylinder and the transmission cylinder are both in a cylindrical shape, the transmission cylinder 17 is nested in the inner side of the outer cylinder 19, and the transmission cylinder 17 can rotate along the inner surface of the outer cylinder 19, that is, the transmission cylinder 17 is in rotational connection with the outer cylinder 19. Through gear transmission, the rotation of the transmission cylinder 17 along the annular inner surface of the outer cylinder is realized.

[0055] In this embodiment, a plurality of gears 10 are arranged in the cavity of the outer cylinder 19, and the gears 10 are in transmission connection with the output end of the driving motor 9. The driving motor 9 is fixed on the cover plate 8. Correspondingly, a gear ring 20 is fixed on the annular inner side of the transmission cylinder 17, and the gear ring 20 is in meshing connection with the gears 10. During the operation of the driving motor 9, the gears 10 are driven to rotate, and through the meshing transmission between the gears 10 and the gear ring 20, the gear ring 20 and the transmission cylinder 17 fixedly connected with the gear ring are driven to rotate. By arranging a plurality of gears 10, sufficient power can be provided for the rotation of the transmission cylinder.

[0056] The upper side of the transmission cylinder 17 is provided with an upper stop ring 18, and the lower side of the transmission cylinder 17 is provided with a lower stop ring 16, and the upper stop ring 18 and the lower stop ring 16 are fixedly connected with the inner surface of the transmission cylinder 17. The upper stop ring 18 and the lower stop ring 16 limit the transmission cylinder, so that the transmission cylinder 17 is always located between the upper stop ring 18 and the lower stop ring 16. In this embodiment, the upper stop ring and the lower stop ring are in an integral structure with the transmission cylinder.

[0057] The impact mechanism comprises a lead block 11, an end face cam 13, a plurality of pull rod assemblies in contact with the end face cam, and the end face cam 13 is connected with the inner surface of the transmission cylinder 17, so that the transmission cylinder 17 drives the end face cam 13 to rotate during rotation. The lead block 11 is located above the pull rod assembly. The pull rod assembly is always in contact with the upper surface of the end face cam 13. As Figure 7As shown, the upper surface of the end face cam is the working end face 15, which is curved and has smooth protrusions. The pull rod assembly is located between the lead block 11 and the support column 27. During its contact with the end face cam, the pull rod assembly moves up and down, supporting the lead block 11 above it to reciprocate vertically. When the lead block 11 moves downward, under its own weight, it exerts a downward impact force on the support column 27 below through the pull rod assembly.

[0058] In this embodiment, a connecting post 7 is fixed at the center of the cover plate 8. The top end of the connecting post 7 is located outside the outer cylinder and connected to the composite cable 6, while the bottom end of the connecting post 7 is located inside the outer cylinder and fixedly connected to the slide cylinder 12. The lead block 11 is located inside the slide cylinder 12, and the lead block 11 is slidably connected to the inner surface of the slide cylinder 12. The slide cylinder 12 guides and limits the vertical reciprocating movement of the lead block 11. Figure 6 As shown, the inner surface of the slide cylinder 12 is provided with several circumferential oil grooves 29, which are filled with lubricating oil. During the continuous reciprocating motion of the lead block 11, the lubricating oil plays a lubricating role in the relative motion between the lead block 11 and the slide cylinder 12, reducing the friction between the lead block and the slide cylinder.

[0059] like Figure 8 As shown, an annular outer ring 30 of the end face cam flange is fixed to the annular outer surface of the end face cam 13. In this embodiment, the outer ring 30 of the end face cam flange and the end face cam 13 are integrally formed. There is an annular gap between the bottom end of the transmission cylinder 17 and the lower retaining ring 16. The outer ring 30 of the end face cam flange is located within this annular gap, and the outer ring 30 of the end face cam flange and the transmission cylinder 17 are connected by a pin 31. Therefore, during the transmission process of the transmission cylinder 17, the torque is transmitted to the outer ring 30 of the end face cam flange through the pin 31, thereby driving the end face cam 13 to rotate together with the transmission cylinder.

[0060] The tie rod assembly includes a horizontal bracket 21, one end of which has a rotating roller 22 that contacts the working end face 15 of the end face cam 13. The other end of the bracket 21 is located below the lead block 11 and is connected to a lower connecting rod 24 via a vertical tie rod 23. The connecting rod 24 is located below the bracket 21, with one end hinged to the bottom end of the tie rod 23 and the other end hinged to the inner surface of the outer cylinder 19. The connecting rod 24 is located above the support column 24, and the connection end of the connecting rod 24 and the tie rod 23 can contact the top surface of the support column 27.

[0061] The impact mechanism in the embodiment comprises four pull rod assemblies, which are evenly spaced along the annular inner side of the outer cylinder, i.e. the included angle between two adjacent pull rod assemblies is 90°. A plurality of support seats 26 are fixed to the inner surface of the outer cylinder below the end face cam, and the support seats are connected by a support ring 25. The end of the connecting rod 24 is hinged to the support ring 25.

[0062] During the rotation of the end face cam 13, when the pull rod assembly in the impact mechanism is in contact with the convex point on the working end face, the convex point drives the pull rod assembly to move upward, and the pull rod assembly supports the lead block above it to move upward. With the continuous rotation of the end face cam, when it moves to the position where the pull rod assemblies are not in contact with the convexities on the working end face, the lead block 11 moves downward along the slide cylinder 12 under the action of its own gravity. During the downward movement of the lead block 11, the pull rod assembly collides with the supporting column, and the impact force generated during the collision of the supporting column is transmitted downward to the probe rod unit. During the movement of the end face cam 13, the reciprocating movement of the lead block 11 in the vertical direction is realized, and the impact force generated during the reciprocating movement of the lead block 11 makes the probe rod unit continuously drill downward.

[0063] As shown in Figure 9 The probe rod unit comprises a probe rod 4, and the center of the probe rod is provided with a POM tube 35. During the drilling of the probe rod unit, the columnar sediment enters and stays in the POM tube 35, thereby realizing the sampling action of the deep-sea sediment. A plurality of arc-shaped grooves 36 are arranged on the probe rod 4 along the axial direction, and a temperature sensing unit 5 is arranged in the arc-shaped grooves 36. The temperature sensing unit 5 comprises a temperature sensor 32 and a temperature probe 33. The temperature sensor 32 is arranged along the axial direction of the probe rod, and one end of the temperature sensor 32 is fixedly connected with the temperature probe 33. The temperature sensor 32 is fixedly arranged in the arc-shaped groove 36 through a plurality of fixed supports 34. In the embodiment, the fixed support 34 comprises two symmetrical arc-shaped support brackets, and an arc-shaped channel is formed between the two symmetrical arc-shaped support brackets, and the temperature sensor is located in the arc-shaped channel. One end of each of the two arc-shaped support brackets is fixedly connected with the probe rod, and the other end of each of the two arc-shaped support brackets is fixedly connected with each other through a bolt. The temperature sensor 32 is fixedly arranged in the fixed support 34 through the tightening bolt. By arranging the temperature sensor 32 in an embedded structure, the temperature sensor can be prevented from being damaged by friction with the surrounding sediment bottom layer.

[0064] The application further discloses a measurement method using the novel gravity sampling and geothermal gradient measuring device.

[0065] In the first step, the device is connected with the composite cable 6 and then is put into water on the working ship. Under the action of its own gravity, the device is quickly inserted into the sea bottom.

[0066] Second step, after the device is inserted into the seabed sediment, the shipboard control room can supply power to the device through the composite cable 6, drive the motor 9 to rotate the gear 10 connected thereto, through the mutual engagement between the gear 10 and the gear ring 20, drive the gear ring 20 and the transmission cylinder 17 fixedly connected thereto to rotate, realize motion transmission.

[0067] During the rotation of the transmission cylinder 17, the pin shaft connection between the end face cam flange outer ring 30 and the transmission cylinder 17 causes the transmission cylinder 17 to drive the end face cam 13 to rotate synchronously.

[0068] Third step, during the rotation of the end face cam 13, the convex points on the end face cam periodically lift the roller, and the bracket connected with the roller also moves upward. During the upward movement of the bracket, the lead block 11 is lifted and slides into the sliding cylinder 12. At the same time, the bracket drives the connecting rod to rotate upward through the pull rod. The connecting end of the connecting rod and the pull rod moves away from the upper surface of the supporting column 27.

[0069] The end face cam 13 continues to rotate, and the convex points on the end face cam move away from the roller. At this time, the roller descends, and the bracket connected with the roller also moves downward. At this time, the bracket drives the connecting rod to rotate downward through the pull rod. During this process, the lead block 11 exerts downward pressure on the bracket under its own gravity. When the connecting end of the connecting rod and the pull rod moves downward to contact and collide with the supporting column, a downward impact force is exerted on the supporting column 27 during the collision process.

[0070] With the rotation of the end face cam 13, the lead block 11 in the sliding cylinder 12 realizes periodic reciprocating movement in the vertical direction. During the downward movement of the lead block 11, the connecting end of the connecting rod and the pull rod is the force exerting end. Through the force exerting end in each connecting rod assembly, the downward pressure of the lead block is sequentially transmitted to the supporting column 27 through the force exerting end, and a downward impact force is continuously exerted on the probe rod unit, thereby realizing the downward drilling of the entire device.

[0071] Fourth step, when the entire device drills downward to the expected depth, the impact mechanism stops working. During the downward drilling of the device, sample collection is realized through the POM tube 35 in the probe rod, and temperature gradient collection is realized through the temperature sensing unit 5 on the probe rod unit.

[0072] The above describes in detail the new gravity sampling and geothermal gradient measuring device and measuring method provided by the present application. The principles and implementation manners of the present application are described by using specific examples, and the above description of the examples is only used to help understand the method of the present application and the core idea thereof. It should be pointed out that, for those skilled in the art, some improvements and modifications can be made to the present application without departing from the principles of the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application. The above description of the disclosed examples enables those skilled in the art to implement or use the present application. Various modifications of the examples will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other examples without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the examples shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A gravity sampling and geothermal gradient measurement device, characterized in that, include: The impact unit includes an outer cylinder and a transmission cylinder. The transmission cylinder is located inside the annular side of the outer cylinder and rotates along the inner surface of the annular side of the outer cylinder. An impact mechanism is provided inside the outer cylinder. During the rotation of the transmission cylinder, the impact mechanism is driven to generate a downward impact force on the probe unit. The probe unit is fixedly connected to the bottom of the impact unit, and includes a probe and several temperature sensing units mounted on the probe. A POM tube is located at the center of the probe. The top of the outer cylinder is fixed with a cover plate, and a fixing post is provided at the center of the cover plate. The top of the fixing post is located outside the outer cylinder and connected to the composite cable, and the bottom of the fixing post is located inside the outer cylinder and connected to the sliding cylinder. The outer annular outer sliding sleeve of the outer cylinder has several counterweight rings spaced apart along the axial direction. The counterweight rings are fixedly connected by connecting rods and are set on the bottom plate of the outer cylinder. The bottom of the outer cylinder is fixedly connected to the probe unit, and a support column is fixed at the center of the top surface of the bottom of the outer cylinder; A gear ring is fixed on the inner annular sidewall of the transmission cylinder, and several gears are provided in the outer cylinder. The gears are connected to the cover plate through the drive motor, and the gears mesh with the gear ring. An upper retaining ring is provided above the transmission cylinder, and a lower retaining ring is provided below the transmission cylinder. The transmission cylinder is located between the upper retaining ring and the lower retaining ring, and both the upper retaining ring and the lower retaining ring are fixedly connected to the outer cylinder. The lead block is slidably positioned inside the slide tube; The end face cam is connected to the transmission cylinder on its annular outer side, and its upper surface is curved with smooth protrusions. Several tie rod assemblies, each tie rod assembly including a horizontally arranged bracket, a vertically arranged tie rod, and a connecting rod rotatably connected to the outer cylinder. One end of the bracket is provided with a roller, which contacts the upper surface of the end face cam. The other end of the bracket is located below the lead block and is hinged to the upper end of the tie rod. The lower end of the tie rod is hinged to one end of the connecting rod, and the other end of the connecting rod is hinged to the outer cylinder. The connection end of the tie rod and the connecting rod is located above the support column. Several tie rod assemblies are evenly spaced along the circumference inside the transmission cylinder; Several support seats are fixed on the inner annular side of the outer cylinder. The support seats are connected by support rings, and one end of the connecting rod is hinged to the support rings.

2. The gravity sampling and geothermal gradient measurement device according to claim 1, characterized in that, The inner surface of the slide cylinder is provided with several oil grooves arranged along the axial direction, and the oil grooves are filled with lubricating oil.

3. The gravity sampling and geothermal gradient measurement device according to claim 1, characterized in that, The outer ring of the end face cam flange is fixedly provided on the annular outer side of the end face cam, and the transmission cylinder is connected to the outer ring of the end face cam flange by a pin.

4. The gravity sampling and geothermal gradient measurement device according to claim 1, characterized in that, The probe unit has several arc-shaped grooves spaced apart along its axial direction, and a temperature sensing unit is installed in the arc-shaped grooves. The temperature sensing unit includes a temperature sensor and a temperature probe. The temperature probe is connected to the temperature sensor, and the temperature sensor is fixedly connected to the probe rod through a fixed bracket.

5. A method for measurement using a gravity sampling and geothermal gradient measuring device as described in any one of claims 1-4, characterized in that, Includes the following steps: S1. After the device enters the water, it quickly inserts towards the seabed under its own gravity. S2. After the device is inserted into the seabed sediment, the transmission cylinder rotates. During its rotation, the impact mechanism continuously generates a downward impact force on the probe unit. Through this impact force, the device can drill downwards. S3. After the device drills down to the expected depth, the impact mechanism stops. The process of the probe drilling down achieves sample collection, and at the same time, the temperature gradient is collected through the temperature sensing unit.

6. The method for measurement using gravity sampling and geothermal gradient measuring device according to claim 5, characterized in that, In step S2, the device is powered by a composite cable, which drives the motor to rotate the gear connected to it. Through the meshing between the gear and the gear ring, the gear ring and the transmission cylinder fixedly connected to it rotate. The transmission cylinder rotates, and the pin connection between the outer ring of the end face cam flange and the transmission cylinder causes the transmission cylinder to drive the end face cam to rotate synchronously. During the rotation of the end face cam, the protrusion on the end face cam periodically lifts the roller, and the bracket connected to the roller also moves upward. During the upward movement of the bracket, the lead block is lifted and slides into the slide cylinder. At the same time, the bracket drives the connecting rod to rotate upward through the pull rod, and the connection end of the pull rod and the connecting rod leaves the upper surface of the support column. As the end face cam continues to rotate, the protrusion on the end face cam leaves the roller, at which point the roller descends, and the bracket connected to the roller also moves downward. The bracket drives the connecting rod to rotate downward through the tie rod, and the lead block moves downward under its own weight, applying downward pressure to the bracket. When the connecting end of the connecting rod and the tie rod moves downward to contact and collide with the support column, the pressure generated by the lead block applies a downward impact force to the support column. As the end face cam rotates, the lead block reciprocates periodically in the vertical direction. During the periodic downward movement of the lead block, the downward pressure of the lead block is transmitted to the load-bearing column through the connection end of the connecting rod and the tie rod in each connecting rod assembly, continuously applying a downward impact force to the probe unit. As the probe unit moves downwards, the sediment enters the POM tube, thus collecting the sample.

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