Press-in type pore pressure sensor for measuring pressure difference through optical fiber and sensing method of press-in type pore pressure sensor

Abstract

The invention relates to a press-in type pore pressure sensor for measuring through optical fiber pressure difference and a sensing method thereof. The sensor comprises a pressure sensing piece and an optical fiber sensing piece detachably arranged on the pressure sensing piece. The pressure sensing piece comprises a sensing piece body and a pressure sensing head arranged at one end of the sensing piece body, and elastic clearance exists between the pressure sensing head and the sensing piece body. A light source is arranged on the induction piece body, is connected with a light source switch, and is connected with the optical fiber induction piece through an optical fiber; a delay opening and closing structure is arranged between the pressure sensing head and the light source switch; according to the utility model, the delay opening and closing structure is arranged, so that after the sensor is started, even if the environment pressure value is suddenly reduced to be lower than the value before starting, the sensor does not sleep immediately, but keeps an opening state, so as to carry out more careful monitoring; only when the environment pressure is lower than the value before starting and the distance is a certain difference value, the system can be converted into a dormant state.

Description

Technical Field

[0001] The invention relates to a pressure-insertion pore pressure sensor for measuring pressure difference through optical fiber and a sensing method thereof. Background Art

[0002] The pressure-insertion pore pressure sensor based on optical fiber pressure difference is a kind of sensor that, when external physical quantity (such as pressure) acts on the modulation zone, the changes of light signals (such as intensity, wavelength, phase, etc.) emitted by the light source are exported and detected through optical fiber and converted into measurable signals.

[0003] Fiber Bragg grating (FBG) or Fabry-Perot interferometer is usually used as the sensing element. When pressure acts on the sensor, the physical structure of the grating or interferometer cavity in the optical fiber changes, resulting in changes in the wavelength of the reflected light or the interference fringes.

[0004] The principle is that external pressure will change the period or refractive index of the fiber grating, thereby changing the wavelength of the reflected light. By detecting the change in wavelength, the magnitude of the pressure can be inferred. It has the advantages of anti-electromagnetic interference, corrosion resistance, high precision and long-term stability.

[0005] The optical signal wavelength change is converted into a measurable, concrete digital value, and it has the characteristics of optical fiber pressure difference measurement with high-precision digital representation.

[0006] It is often used to monitor pore water pressure in hydraulic structures, dams, tunnels and other projects. Due to its high-precision measurement of pore water pressure, it is widely used in civil engineering, geological monitoring and other fields.

[0007] Due to the requirements of its application scenarios, the sensor has an extremely long working cycle. Conventional press-fit pore pressure fiber optic sensors are online all year round, and their battery life and electronic components suffer serious wear and tear, resulting in their lifespan being unable to meet the entire monitoring cycle.

[0008] Some sensors achieve normally closed state by setting a pre-start value, but the switching between the open and closed states is based on a specific pressure value. This means that when the pressure value fluctuates above and below the set pre-start value, the sensor will frequently switch between the open and closed states. In the long run, the failure rate will remain high. Summary of the invention

[0009] The object of the present invention is to provide a pressure-insertion pore pressure sensor and a sensing method thereof for measuring differential pressure through optical fiber, so as to solve the problems raised in the above-mentioned background technology.

[0010] To achieve the above object, the present invention provides the following technical solutions: A press-in type pore pressure sensor for measuring differential pressure through optical fiber, comprising a pressure sensing element and an optical fiber sensing element detachably arranged on the pressure sensing element; The pressure sensing element includes a sensing element body and a pressure sensing head arranged at one end of the sensing element body, and there is an elastic clearance between the pressure sensing head and the sensing element body; A light source is arranged on the sensing element body, the light source is connected to a light source switch, and the light source is connected to the optical fiber sensing element through an optical fiber; A delay opening and closing structure is arranged between the pressure sensing head and the light source switch; When the pressure sensing head approaches the sensing element body until the elastic clearance between the two is completely eliminated, the delay opening and closing structure controls the light source to be powered on through the light source switch; And in the process of the pressure sensing head moving away from the sensing element body and restoring the elastic clearance between the two, the disconnection timing of the light source switch for disconnecting the light source is delayed.

[0011] For the press-in type pore pressure sensor for measuring differential pressure through optical fiber as described above: An inner sleeve is installed in the sensing element body, one end of the pressure sensing head extends into the inner sleeve, and the other end protrudes from the inner sleeve as a contact part; A ring platform is formed on the outer periphery of a section of the pressure sensing head extending into the inner sleeve. The pressure sensing head and the inner sleeve are elastically connected by a compression spring and fixed on the sensing element body through a flange cover.

[0012] For the press-in type pore pressure sensor for measuring differential pressure through optical fiber as described above: Installation guide ribs are integrally arranged on the inner wall of the inner sleeve along the axial direction, and a guide groove for sliding cooperation with the installation guide ribs is opened on the ring platform.

[0013] For the press-in type pore pressure sensor for measuring differential pressure through optical fiber as described above: A switch mechanical arm is rotatably arranged on the light source switch, and the delay opening and closing structure includes a tension spring connecting the light source switch and the end of the switch mechanical arm; When the switch mechanical arm is vertically downward, the tension spring reaches the maximum tensile amount and is in a balanced state, so that the light source switch is at the critical position of being powered on or off.

[0014] For the press-in type pore pressure sensor for measuring differential pressure through optical fiber as described above: One end of the outer periphery of a section of the pressure sensing head protruding from the sensing element body is rotatably connected to one end of a push-pull member, and the other end of the push-pull member is rotatably connected to a push ring; An embedding hole is formed on the inner wall of the push ring, a ball is movably embedded in the embedding hole, and the push ring is matched with a rotating sleeve; Among them, mounting posts are arranged on the outer wall of the sensing element body, the rotating sleeve is rotatably arranged on the mounting posts, and the pushing ring is sleeved with the rotating sleeve; a spiral groove is formed on the outer wall of the rotating sleeve, and the ball is also rolling and fitted on the spiral groove.

[0015] The press-in type pore pressure sensor measured by fiber optic differential pressure as described above: Two contact rods parallel to the rotating sleeve are arranged on the rotating sleeve, there is a gap between the two contact rods, and the contact rods cooperate with the switch robotic arm.

[0016] The press-in type pore pressure sensor measured by fiber optic differential pressure as described above: The fiber optic sensing element is installed on the hoop structure, and the hoop structure is connected to the sensing element body; The hoop structure includes two semi-circular first hoops and second hoops, the first hoop and the second hoop are hinged, and a mounting arm is formed at one end of the second hoop; The fiber optic sensing element is installed on the mounting arm.

[0017] The press-in type pore pressure sensor measured by fiber optic differential pressure as described above: One end of the fiber optic sensing element is fixedly connected to the clamp, the clamp cooperates with the through hole formed at the end of the mounting arm, and is installed by bolts.

[0018] The press-in type pore pressure sensor measured by fiber optic differential pressure as described above: A screw rod is rotatably arranged on one side of the mounting arm, a nut sleeve is threadedly connected to the screw rod, one end of a connecting rod is rotatably connected to one side of the nut sleeve, and the other end of the connecting rod is rotatably connected to the outer wall of the first hoop.

[0019] A method for sensing by a press-in type pore pressure sensor measured by fiber optic differential pressure includes the following steps: Step 1, preset the starting value. Determine the maximum value of micro-vibration according to the on-site situation of the measured environment, and select a compression spring with a matching elastic modulus; Step 2, assemble the sensor. Sequentially install the compression spring, the inner sleeve, and the pressure sensing head into the sensing element body and firmly connect them to the sensing element body through a flange cover; then install the fiber optic sensing element on the outer wall of the sensing element body through the hoop structure, and finally connect the light source and the fiber optic sensing element through an optical fiber; Step 3, fixed-point layout. Set the assembled sensor at the measured position according to the calibrated monitoring point, and detect the working states of the pressure sensing element and the fiber optic sensing element under the energized state; Step 4, bus connection. Connect the other end of the fiber optic sensing element to the data receiving end through an optical fiber to ensure that the sensors at each point can communicate with the data receiving end normally, and then connect the data receiving end to the induction main station; Step 5, data collection and recording: Monitor the pressure values received and transmitted by the data receiving end in real time at the induction master station, and record the data trend, continuity, peak and trough values in a register.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: An elastic clearance is provided between the pressure sensing head and the induction element body in the present invention to modulate the pre-start value of the entire sensor; for example, a specific pre-induction start value can be preset. When the pre-induction value is not reached, the sensor remains normally closed to filter out conventional micro-vibrations. In the present invention, by providing an elastic clearance between the pressure sensing head and the induction element body, conventional micro-vibrations are not sufficient to activate this sensor, and it is kept in a dormant state as much as possible to increase its battery life.

[0021] A delay opening and closing structure is provided in the present invention, so that even after the sensor is activated, even if the ambient pressure value drops suddenly below the pre-start value, it will not immediately go into dormancy, but will remain in the open state for more meticulous monitoring; it will only go into dormancy when the ambient pressure is lower than the pre-start value and there is a certain difference. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic structural diagram of a push-in type pore pressure sensor measured by fiber optic differential pressure.

[0023] Figure 2 It is a schematic structural diagram of another orientation of a push-in type pore pressure sensor measured by fiber optic differential pressure.

[0024] Figure 3 It is a schematic structural diagram of the pressure sensing element in a push-in type pore pressure sensor measured by fiber optic differential pressure.

[0025] Figure 4 It is a schematic diagram of the partial disassembly structure of the pressure sensing element.

[0026] Figure 5 For Figure 4 Another schematic diagram of the orientation.

[0027] Figure 6 For Figure 5 An enlarged view of part A in

[0028] Figure 7 It is a schematic structural diagram of the push-in type pore pressure sensor measured by fiber optic differential pressure after removing the pressure sensing head.

[0029] Figure 8 For Figure 7 An enlarged view of part B in

[0030] Figure 9 For Figure 7 A schematic diagram of the disassembly of the rotating sleeve, push ring, and ball bearings on the basis of

[0031] Figure 10 is Figure 9 An enlarged view of part C in

[0032] Figure 11 Schematic diagrams of the disassembled rotating sleeve, pushing ring, and ball structure

[0033] Figure 12 is a schematic diagram of the structure of the press-in type pore pressure sensor measured by optical fiber differential pressure in another orientation

[0034] Figure 13 is Figure 12 An enlarged view of part D in

[0035] Figure 14 is a schematic diagram of the structure after removing the optical fiber sensing element and the clamp from the mounting arm

[0036] In the figure: 1 - pressure sensing element; 101 - pressure sensing head; 1011 - annular platform; 1012 - guide groove; 102 - inner sleeve; 1021 - mounting guide edge; 103 - compression spring; 104 - flange cover; 105 - light source switch; 1051 - switch robotic arm; 106 - mounting post; 107 - rotating sleeve; 1071 - contact rod; 1072 - spiral groove; 108 - pushing ring; 1081 - embedding hole; 109 - ball; 110 - tension spring; 2 - optical fiber sensing element; 201 - light source; 202 - clamp; 203 - mounting arm; 204 - first hoop; 205 - second hoop; 206 - screw rod; 207 - screw sleeve; 208 - connecting rod; 3 - pushing and pulling member Specific embodiments

[0037] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments

[0038] Please refer to Figures 1 to 14 , as an embodiment of the present invention, the press-in type pore pressure sensor measured by optical fiber differential pressure includes a pressure sensing element 1 and an optical fiber sensing element 2 detachably arranged on the pressure sensing element 1 The pressure sensing element 1 includes a sensing element body and a pressure sensing head 101 arranged at one end of the sensing element body, and there is an elastic clearance between the pressure sensing head 101 and the sensing element body A light source 201 is arranged on the sensing element body, the light source 201 is connected to the light source switch 105, and the light source 201 is connected to the optical fiber sensing element 2 through an optical fiber A delay opening and closing structure is arranged between the pressure sensing head 101 and the light source switch 105 When the elastic clearance between the pressure-sensitive head 101 and the sensor body approaches until it is completely eliminated, the light source switch 105 controls the power-on of the light source 201; During the process that the pressure-sensitive head 101 moves away from the sensor body and the elastic clearance between them is restored, the disconnection timing of the light source switch 105 to disconnect the light source 201 is delayed.

[0039] In this embodiment, an elastic clearance is provided between the pressure-sensitive head 101 and the sensor body in the present invention to modulate the pre-start value of the entire sensor; for example, the specific pre-sensing start value can be preset. When the pre-sensing value is not reached, the sensor remains in the normally closed state to filter out regular micro-vibrations; Among them, regular micro-vibrations are usually periodic or quasi-periodic, with clear time laws and frequency characteristics. For example, simple harmonic vibration, forced vibration, etc.; and regular micro-vibrations are usually continuous and stable, and the vibration process can last for a long time, such as the steady-state vibration of a construction machinery system; However, in the present invention, by providing an elastic clearance between the pressure-sensitive head 101 and the sensor body, regular micro-vibrations are not sufficient to activate the present sensor, and it is kept in the dormant state as much as possible to increase its battery life.

[0040] In case of macroscopic vibration, the pressure value will exceed the pre-sensing start value, and at this time, the sensor switches from the dormant state to the working state; among them, macroscopic vibration has a large vibration amplitude, usually at the millimeter level or higher, which has a direct impact on the structural stability; and macroscopic vibration is often non-periodic, without clear rules, and may be random or transient. For example, ground vibration caused by an earthquake, explosion shock wave, etc.

[0041] In the present invention, a delay opening and closing structure is provided, so that even after the sensor is activated, even if the ambient pressure value drops suddenly below the pre-start value, it will not immediately go into the dormant state, but will remain in the open state for more careful monitoring; it will only switch to the dormant state when the ambient pressure is lower than the pre-start value and there is a certain difference.

[0042] As a further solution of the present invention, an inner sleeve 102 is installed in the sensor body, one end of the pressure-sensitive head 101 extends into the inner sleeve 102, and the other end protrudes from the inner sleeve 102 as a contact part; A ring platform 1011 is formed on the outer periphery of a section of the pressure-sensitive head 101 extending into the inner sleeve 102. The pressure-sensitive head 101 and the inner sleeve 102 are elastically connected by a compression spring 103 and fixed to the sensor body through a flange cover 104.

[0043] It should be noted that the pressure sensor head 101 in the present invention has a split structure, including an external section and an embedded section, and the embedded section is the section extending into the inner sleeve 102. When assembling this split structure, first slip the flange cover 104 onto the embedded section and then fix the external section and the embedded section together.

[0044] When the flange cover 104 is fixed on the sensing element body, since the compression spring 103 is pre-compressed, a force away from the sensing element body will be exerted on the pressure sensor head 101. However, due to the annular platform 1011 being blocked by the flange cover 104, the compression spring 103 can be kept under pressure all the time, that is, a certain elastic clearance is achieved between the pressure sensor head 101 and the inner sleeve 102 through the compression spring 103.

[0045] As a further solution of the present invention, in order to prevent relative rotation between the pressure sensor head 101 and the inner sleeve 102, mounting guide ribs 1021 are integrally provided on the inner wall of the inner sleeve 102 along the axial direction, and a guide groove 1012 for sliding cooperation with the mounting guide ribs 1021 is formed on the annular platform 1011.

[0046] In this embodiment, since the inner sleeve 102 has been fixed to the sensing element body through the flange cover 104, the inner sleeve 102 cannot rotate. With the cooperation of the provided mounting guide ribs 1021 and the guide groove 1012, the pressure sensor head 101 also cannot rotate and can only expand and contract relative to the inner sleeve 102.

[0047] As a further solution of the present invention, a switch robotic arm 1051 is rotatably provided on the light source switch 105, and the delay opening and closing structure includes a tension spring 110 connecting the light source switch 105 and the end of the switch robotic arm 1051. When the switch robotic arm 1051 is vertically downward, the tension spring 110 reaches the maximum tensile amount and is in a balanced state, so that the light source switch 105 is at the critical position of turning on and off.

[0048] In this embodiment, when the pressure sensor head 101 is subjected to pressure and this pressure is less than the pre-start value, although the switch robotic arm 1051 rotates, it does not reach the balanced position, so the light source switch 105 will not turn on.

[0049] During the process that the pressure received by the pressure sensor head 101 suddenly rises and exceeds the pre-start value, as long as the pressure slightly exceeds the previous value, that is, the switch robotic arm 1051 slightly exceeds the critical position, the switch robotic arm 1051 will quickly act to energize the light source 201. During the process that the pressure received by the pressure sensor head 101 decreases, it will turn off only when the switch robotic arm 1051 reverses and slightly exceeds the balanced position in the reverse direction.

[0050] As a further solution of the present invention, one end of the outer periphery of the pressure-sensitive head 101 protruding from the main body of the sensing member is rotatably connected to one end of the push-pull member 3, and the other end of the push-pull member 3 is rotatably connected to the push ring 108; A fitting hole 1081 is formed on the inner wall of the push ring 108, a ball 109 is movably fitted in the fitting hole 1081, and the push ring 108 and the rotating sleeve 107 are matched; Wherein, a mounting post 106 is arranged on the outer wall of the main body of the sensing member, the rotating sleeve 107 is rotatably arranged on the mounting post 106, and the push ring 108 is sleeved on the rotating sleeve 107; a spiral groove 1072 is formed on the outer wall of the rotating sleeve 107, and the ball 109 is also rollingly fitted in the spiral groove 1072.

[0051] In this embodiment, when the pressure-sensitive head 101 is subjected to a pressure greater than the pre-pressure of the compression spring 103, the pressure-sensitive head 101 will contract into the inner sleeve 102. During the contraction of the pressure-sensitive head 101, the push ring 108 is driven away from the main body of the sensing member through the push-pull member 3; During this process, the push ring 108 drives the ball 109 to also move away from the main body of the sensing member, and the ball 109 cooperates with the spiral groove 1072 to drive the rotating sleeve 107 to rotate.

[0052] As a further solution of the present invention, two contact rods 1071 parallel to the rotating sleeve 107 are arranged on the rotating sleeve 107, there is a gap between the two contact rods 1071, and the contact rods 1071 cooperate with the switch mechanical arm 1051.

[0053] In this embodiment, precisely because there is a gap between the two contact rods 1071, when one side of the contact rod 1071 drives the switch mechanical arm 1051 to cross the balance position, if the pressure decreases, the contact rod 1071 on the other side will not immediately drive the switch mechanical arm 1051 to quickly reverse. Instead, after eliminating the gap between the contact rod 1071 on the other side and the switch mechanical arm 1051, the contact rod 1071 on the other side will reverse to drive the switch mechanical arm 1051 to reverse; and when the contact rod 1071 on the other side drives the switch mechanical arm 1051 to reverse to the balance position, it will continue to reverse to cut off the power supply of the light source 201 through the light source switch 105.

[0054] As a further solution of the present invention, the optical fiber sensing member 2 is installed on a hoop structure, and the hoop structure is connected to the main body of the sensing member; The hoop structure includes two semi-circular first hoops 204 and second hoops 205, the first hoop 204 and the second hoop 205 are hinged, and a mounting arm 203 is formed at one end of the second hoop 205; The optical fiber sensing member 2 is installed on the mounting arm 203.

[0055] In this embodiment, two hinged hoops are used to make the entire hoop structure have an openable and closable function, which facilitates fixing the entire hoop structure and the mounting arm 203 on the outer wall of the sensing element body.

[0056] As a further solution of the present invention, one end of the optical fiber sensing element 2 is fixedly connected to the clamp 202, and the clamp 202 is matched with the perforation formed at the end of the mounting arm 203 and is installed by bolts.

[0057] In this embodiment, the provided clamp 202 is used to achieve a detachable connection between the optical fiber sensing element 2 and the mounting arm 203.

[0058] As a further solution of the present invention, a screw 206 is rotatably provided on one side of the mounting arm 203, a nut 207 is threadedly connected to the screw 206, one end of a connecting rod 208 is rotatably connected to one side of the nut 207, and the other end of the connecting rod 208 is rotatably connected to the outer wall of the first hoop 204.

[0059] In this embodiment, by rotating the screw 206, the nut 207 can be driven to move along the length direction of the screw 206, and then the hinged first hoop 204 and the second hoop 205 can be controlled to open and close through the connecting rod 208.

[0060] In addition, the present invention also proposes a method for sensing by using the press-in type pore pressure sensor through optical fiber differential pressure measurement as described above, including the following steps: Step 1, preset the starting value before startup. Determine the maximum value of micro-vibration according to the on-site conditions of the measured environment (including data such as the vibration of construction machinery and the vibration caused by the load of road vehicles passing by), and select a compression spring 103 with a matching elastic modulus. Step 2, assemble the sensor. Sequentially install the compression spring 103, the inner sleeve 102, and the pressure sensing head 101 into the sensing element body and firmly connect them to the sensing element body through the flange cover 104; then install the optical fiber sensing element 2 on the outer wall of the sensing element body through the hoop structure, and finally connect the light source 201 and the optical fiber sensing element 2 through an optical fiber. Step 3, fixed-point layout. Set the assembled sensor at the measured position according to the calibrated monitoring points, and detect the working states of the pressure sensing element 1 and the optical fiber sensing element 2 in the powered-on state. Step 4, bus connection. Connect the other end of the optical fiber sensing element 2 to the data receiving end through an optical fiber to ensure that the sensors at each point can communicate with the data receiving end normally, and then connect the data receiving end to the sensing master station. Step 5, data collection and recording. Real-time monitor the pressure values transmitted and received by the data receiving end at the sensing master station, and record the data trend, continuity, peak and valley values in a register.

[0061] The above embodiments are illustrative rather than restrictive, so without departing from the spirit or basic characteristics of the present invention, all technical solutions that can implement the present invention in other specific forms are included in the present invention.

Claims

1. A press-in pore pressure sensor for measuring by optical fiber differential pressure, comprising a pressure sensing element (1) and an optical fiber sensing element (2) detachably arranged on the pressure sensing element (1), characterized in that, The pressure-sensitive sensing element (1) includes a sensing element body and a pressure-sensitive head (101) provided at one end of the sensing element body, and there is an elastic clearance between the pressure-sensitive head (101) and the sensing element body; A light source (201) is provided on the sensing element body, the light source (201) is connected to a light source switch (105), and the light source (201) is connected to an optical fiber sensing element (2) through an optical fiber; A delay opening and closing structure is provided between the pressure-sensitive head (101) and the light source switch (105); When the pressure-sensitive head (101) approaches the sensing element body until the elastic clearance between them is completely eliminated, the delay opening and closing structure controls the light source (201) to be energized through the light source switch (105); And during the process that the pressure-sensitive head (101) moves away from the sensing element body and restores the elastic clearance between them, the disconnection timing of the light source switch (105) to disconnect the light source (201) is delayed.

2. The piezometric pressure sensor of the push-in type measured by optical fiber differential pressure according to claim 1, wherein An inner sleeve (102) is installed in the sensing element body, one end of the pressure-sensitive head (101) extends into the inner sleeve (102), and the other end protrudes from the inner sleeve (102) as a contact part; A ring platform (1011) is formed on the outer periphery of a section of the pressure-sensitive head (101) extending into the inner sleeve (102). The pressure-sensitive head (101) and the inner sleeve (102) are elastically connected by a compression spring (103) and fixed on the sensing element body by a flange cover (104).

3. The piezometric pressure sensor of the press-in type through fiber optic differential pressure measurement according to claim 2, wherein Installation guide ribs (1021) are integrally provided on the inner wall of the inner sleeve (102) along the axial direction, and a guide groove (1012) for sliding cooperation with the installation guide ribs (1021) is provided on the ring platform (1011).

4. The piezometric pressure sensor by fiber optic differential pressure measurement according to claim 2, wherein A switch mechanical arm (1051) is rotatably provided on the light source switch (105), and the delay opening and closing structure includes a tension spring (110) connecting the light source switch (105) and the end of the switch mechanical arm (1051); When the switch mechanical arm (1051) is vertically downward, the tension spring (110) reaches the maximum tensile amount and is in a balanced state, so that the light source switch (105) is in the critical position of energization and de-energization.

5. The piezometric pressure sensor by fiber optic differential pressure measurement according to claim 4, wherein One end of the outer periphery of a section of the pressure-sensitive head (101) protruding from the sensing element body is rotatably connected to one end of a push-pull member (3), and the other end of the push-pull member (3) is rotatably connected to a push ring (108); An insertion hole (1081) is formed on the inner wall of the push ring (108), a ball (109) is movably inserted in the insertion hole (1081), and the push ring (108) is matched with a rotating sleeve (107); An installation post (106) is provided on the outer wall of the sensing element body, the rotating sleeve (107) is rotatably provided on the installation post (106), and the push ring (108) is sleeved with the rotating sleeve (107); a spiral groove (1072) is formed on the outer wall of the rotating sleeve (107), and the ball (109) also rolls and fits in the spiral groove (1072).

6. The press-in type pore pressure sensor for fiber optic differential pressure measurement according to claim 5, characterized in that, The rotating sleeve (107) is provided with two touch rods (1071) parallel to the rotating sleeve (107), a gap is provided between the two touch rods (1071), and the touch rods (1071) cooperate with the switch mechanical arm (1051).

7. The press-in pore pressure sensor by fiber optic differential pressure measurement according to claim 2, characterized in that, The optical fiber sensing element (2) is mounted on a hoop structure, and the hoop structure is connected to the sensing element body; The hoop structure comprises two semi-annular first hoops (204) and a second hoops (205), the first hoops (204) and the second hoops (205) being hinged, and a mounting arm (203) is formed at one end of the second hoops (205); The optical fiber sensing component (2) is mounted on the mounting arm (203).

8. A push-in pore pressure sensor for measuring differential pressure through optical fiber according to claim 7, characterized in that, One end of the optical fiber sensing component (2) is fixedly connected to the clamp (202), and the clamp (202) matches a through hole formed at the end of the mounting arm (203) and is mounted by means of bolts.

9. A press-in type pore pressure sensor for fiber optic differential pressure measurement according to claim 7, characterized in that, A screw rod (206) is rotatably provided on one side of the mounting arm (203), a screw sleeve (207) is threadedly connected to the screw rod (206), one side of the screw sleeve (207) is rotatably connected to one end of a connecting rod (208), and the other end of the connecting rod (208) is rotatably connected to the outer wall of the first hoop (204).

10. An induction method of the pressure-injection pore pressure sensor through optical fiber differential pressure measurement as claimed in claim 7, characterized in that, The steps include: Step 1: pre-adjust the pre-start value, determine the maximum value of the micro-vibration according to the on-site conditions of the measured environment, and select a compression spring (103) with a matching elastic modulus; Step 2, assembling the sensor, sequentially installing the compression spring (103), the built-in sleeve (102), and the pressure sensing head (101) into the sensing component body and firmly connecting them to the sensing component body through the flange cover (104); then installing the optical fiber sensing component (2) on the outer wall of the sensing component body through the hoop structure; and finally connecting the light source (201) and the optical fiber sensing component (2) through the optical fiber; Step 3: fixed-point arrangement, placing the assembled sensors at the measured positions according to the calibrated monitoring points, and detecting the working status of the pressure sensing element (1) and the optical fiber sensing element (2) when powered on; Step 4: bus connection: connect the other end of the optical fiber sensing element (2) to the data receiving end through the optical fiber to ensure that the sensor at each point can communicate normally with the data receiving end, and then connect the data receiving end to the sensing main station; Step 5: Data collection and recording: monitor the pressure values ​​sent and received by the data receiving end in real time at the sensing station, and record the data trend, continuity, peak and trough values.

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