Filling device and filling method for high-pressure-resistant stress sensing element

Abstract

The invention discloses a high-pressure-resistant stress sensing element filling device which comprises a rack, the oil filling clamping tool comprises an oil filling fixing seat and a plug which are oppositely arranged up and down and can relatively move up and down, the oil filling fixing seat is provided with an oil conveying connector, the top of the oil conveying connector upwards extends out of the top face of the oil filling fixing seat, and an oil conveying pipeline and a liquid discharging pipeline which are communicated with the interior of the oil conveying connector are arranged in the oil filling fixing seat; three pipe orifices of the three-way pipe are respectively connected with the oil conveying pipeline, the second connecting pipe and the fourth connecting pipe; the pressurizing liquid storage tank is provided with an exhaust port, a pressurizing port and an oil conveying port, the oil conveying port is connected with the second connecting pipe, and oil in the pressurizing liquid storage tank is conveyed into the oil conveying pipeline through the second connecting pipe; the vacuum machine is connected with the fourth connecting pipe; the flow meter is used for monitoring the liquid flow in the second connecting pipe; the vacuum degree detection device is used for monitoring the vacuum degree in the filling pipeline; the drain valve is used for controlling the connection and disconnection of the fifth connecting pipe; the liquid conduction valve is used for controlling the connection and disconnection of the second connecting pipe; and the vacuum conduction valve is used for controlling the on-off of the fourth connecting pipe.

Description

Technical Field

[0001] This invention belongs to the field of automated production equipment technology, specifically relating to a filling device and filling method for a high-pressure stress-resistant sensing element. Background Technology

[0002] Figure 1 and Figure 2 The image shows a high-pressure stress sensing element used in coal mines to test the extrusion pressure of coal seams. Figure 1 and Figure 2 As shown, the high-pressure stress sensing element includes a sealed shaped tube 100, an oil pipe 101, and a connector 102. The sealed shaped tube 100 is a sealed structure filled with oil. The sealed shaped tube 100 is connected to the connector 102 via the oil pipe 101. A one-way valve 103 is installed inside the connector 102, allowing the oil to flow only in one direction. The high-pressure stress sensing element is installed 9-15 meters deep into the coal seam, inside a stress observation hole in the coal mine roadway. It is used to monitor the dynamic changes in stress and pressure of the strata during mine operations, to understand the strata structure and stress distribution, and to provide early warnings of abnormal strata conditions, thus ensuring the safety of coal mine operations.

[0003] When producing this type of high-pressure stress sensing element, the oil is poured into the sealed shaped tube 100 through the connector 102 and the oil delivery pipe 101. However, to meet the application requirements in mines, the diameter of the oil delivery pipe 101 is very small, and its length is relatively long, typically several meters or even tens of meters. During filling, it needs to be rolled up to avoid taking up too much space. Due to the long length and small diameter of the oil delivery pipe, the lack of an venting structure on the oil delivery pipe 101, and the 90° angle between the inlet end 101a of the oil delivery pipe 101 and the filling port 102a of the connector 102, conventional atmospheric pressure gravity-flow filling equipment or pressure filling equipment for bottles and tanks is insufficient to fill the oil into the sealed shaped tube 100. Furthermore, since both ends of the connector 102 are open, it is necessary to ensure a tight seal under high pressure from both the upper and lower openings to prevent oil leakage during filling. Therefore, specialized filling equipment needs to be designed for this type of high-pressure stress sensing element to achieve oil filling production. Summary of the Invention

[0004] The purpose of this invention is to provide a filling device and method for a high-pressure stress-resistant sensing element, which can realize the filling of oil into the high-pressure stress-resistant sensing element used for coal seam extrusion pressure testing in coal mines.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A high-pressure stress-resistant sensing element filling device includes: a frame; an oil filling clamping fixture mounted on the frame, the oil filling clamping fixture including an oil filling base, a plug, and a plug pressing drive unit, the plug and the oil filling base being vertically opposite each other and movable vertically relative to each other, the plug pressing drive unit controlling the plug to move downward and providing downward pressure to the plug, the oil filling base being provided with an oil delivery connector, the top of the oil delivery connector extending upward from the top surface of the oil filling base, the oil filling base being provided with an oil delivery pipeline communicating with the oil delivery connector and a drain pipeline communicating with the oil delivery connector, the drain pipeline being connected to a fifth connecting pipe; a tee pipe, one port of the tee pipe being connected to the... The system includes: an oil pipeline connected to a second connecting pipe and a fourth connecting pipe; a pressurized storage tank mounted on the frame, equipped with an exhaust port, a pressurization port, and an oil inlet; the pressurization port connected to an external pressurization device; the oil inlet connected to the second connecting pipe; oil from the pressurized storage tank entering the oil pipeline via the second connecting pipe; a vacuum machine connected to the fourth connecting pipe; a flow meter for monitoring the liquid flow in the second connecting pipe; a vacuum detection device for monitoring the vacuum level in the filling pipeline; a drain valve controlling the opening and closing of the fifth connecting pipe; a liquid flow control valve controlling the opening and closing of the second connecting pipe; and a vacuum flow control valve controlling the opening and closing of the fourth connecting pipe.

[0007] In some embodiments, a gas-liquid separator is further included, the fourth connecting pipe is connected to the inlet of the gas-liquid separator, the exhaust port of the gas-liquid separator is connected to the third connecting pipe, and the other end of the third connecting pipe is connected to the vacuum machine.

[0008] In some embodiments, the pressurized storage tank is positioned at a height higher than the oil filling clamping fixture.

[0009] In some embodiments, the system further includes an oil storage basin and an oil pump. The oil storage basin is connected to the oil inlet of the pressurized liquid storage tank via a first connecting pipe. The oil in the oil storage basin is added to the pressurized liquid storage tank via the first connecting pipe under the action of the oil pump.

[0010] In some embodiments, an oil drain pan is also included, and the fifth connecting pipe drains oil into the oil drain pan.

[0011] In some embodiments, the high-pressure stress sensing element includes a sealed shaped tube, a connector, and an oil supply pipe connecting the sealed shaped tube and the connector; a one-way valve is provided inside the connector, and the connector has a first port and a second port at both axial ends, with liquid flowing from the first port to the second port; the connector is disposed on the oil filling fixing seat, and the oil supply connector extends from the top of the oil filling fixing seat and enters the connector from the first port; the plug is used to seal the second port.

[0012] In some embodiments, the plug is a cap-type connector that covers the periphery of the end of the connector.

[0013] In some embodiments, the plug pressing drive unit is a cylinder, which is mounted on a bracket fixed to the frame. The piston rod of the cylinder is connected to a pressure rod, which is connected to the plug. A rubber pressure sleeve is provided between the pressure rod and the plug.

[0014] In some embodiments, the rack is provided with an operation panel with a display screen.

[0015] In some embodiments, an operating table is provided on the frame, and the oil filling clamping fixture is disposed on the operating table.

[0016] The present invention also provides a method for filling using the aforementioned high-pressure stress-sensing element filling device, comprising the following steps:

[0017] The connector of the high-pressure stress sensing element is installed onto the filling fixture, and the plug seals the second port of the connector.

[0018] Control the vacuum valve to the open state, start the vacuum machine to exhaust air, and monitor the airtightness and vacuum level in the filling pipeline;

[0019] After exhausting the air, close the vacuum valve to enter the vacuum holding stage;

[0020] After the vacuum is maintained for a certain period of time, the vacuum detection device monitors whether the vacuum degree has reached the set value. If it has, the liquid conduction valve is controlled to be in the conduction state, and the oil flows from the pressurized storage tank into the oil delivery joint and enters the connector. It then flows through the oil delivery pipe of the high pressure stress sensing element into the sealed special-shaped tube of the high pressure stress sensing element.

[0021] After filling a sensor element, close the liquid inlet valve and open the drain valve to drain the excess oil.

[0022] Remove the connector of the pre-filled high-pressure stress sensing element, install the connector of another high-pressure stress sensing element, and repeat the above steps to fill the new high-pressure stress sensing element with oil.

[0023] As can be seen from the above technical solutions, this invention designs a specific structure for the oil filling clamping fixture of the high-pressure stress sensing element used for coal seam compression pressure detection. During the filling process, the plug blocks the non-filling port and provides sufficient downward pressure to resist the pressure during high-pressure oil filling. Pressurized oil filling can be achieved while ensuring airtightness. At the same time, by maintaining vacuum and cooperating with a pressurized liquid storage tank, oil filling is achieved by applying external air pressure. This filling method provides an efficient filling solution for small-diameter sealed containers (the sealed irregular tube of the stress sensor) by utilizing negative pressure to draw a vacuum and applying external pressure. It solves the problem of filling small-diameter sealed containers, and the filling volume is accurate, the filling efficiency is high, and the operation is simple and convenient. After manually clamping the connector, the filling can be fully automated, and mass production can be realized. Attached Figure Description

[0024] To more clearly illustrate the embodiments of the present invention, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the structure of a high-pressure stress-resistant sensing element;

[0026] Figure 2 This is a cross-sectional view of a high-pressure stress-resistant sensing element.

[0027] Figure 3 This is a schematic diagram of the high-pressure stress sensing element filling device according to an embodiment of the present invention;

[0028] Figure 4 This is a schematic diagram of the structure of the oil filling clamping tool according to an embodiment of the present invention;

[0029] Figure 5 This is a partial cross-sectional view of the high-pressure stress sensing element and the oil filling clamping fixture assembled together according to an embodiment of the present invention.

[0030] Figure 6 This is a schematic diagram showing the connection of each valve body in the high-pressure stress sensing element filling device according to an embodiment of the present invention.

[0031] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings. Detailed Implementation

[0032] The present invention will now be described in detail with reference to the accompanying drawings. In describing the embodiments of the present invention, for ease of explanation, the drawings illustrating the device structure will be partially enlarged, not according to general proportions. Furthermore, the schematic diagrams are merely examples and should not be construed as limiting the scope of protection of the present invention. It should be noted that the drawings are simplified and use non-precise proportions, intended only to facilitate and clearly illustrate the embodiments of the present invention. Additionally, in the description of this application, terms such as "first" and "second" are used only to distinguish descriptions and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Terms such as "positive," "negative," "bottom," "upper," "lower," "front," "rear," "left," and "right" indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, not indicating or implying 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.

[0033] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can also refer to the internal connection of two components; and they can refer to a wireless connection or a wired connection. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0034] like Figure 3 As shown, the high-pressure stress sensing element filling device of this embodiment includes a frame 1, an oil filling clamping fixture 2, a pressurized liquid storage tank 3, a vacuum machine 4, a flow meter 5, a vacuum degree detection device 6, a vacuum conduction valve 7, a liquid conduction valve 8, a drain valve 9, and a detection switch 10. As an optional embodiment, this embodiment also includes a gas-liquid separator 11.

[0035] The frame 1 is equipped with an operating platform 1-1, and the oil filling clamping fixture 2 is mounted on the operating platform 1-1. The vacuum machine 4 is located below the operating platform 1-1. The pressurized liquid storage tank 3 and the gas-liquid separator 11 are mounted on the frame 1, and their heights are both higher than the height of the oil filling clamping fixture 2. The pressurized liquid storage tank 3 stores the oil to be filled. The oil is pressurized and then filled into the sealed shaped tube 100 through the connector 102 of the high-pressure stress sensing element and the oil delivery pipe 101.

[0036] The flow meter 5 and the vacuum detection device 6 are both mounted on the frame 1. The frame 1 is also equipped with an operation panel 12 with a display screen. The detection results of the flow meter 5 and the vacuum detection device 6 can be displayed on the display screen of the operation panel 12 so that the operator can understand the filling situation in a timely manner.

[0037] Optionally, this embodiment also includes an oil storage basin 13 and an oil drain basin 14. The oil storage basin 13 stores the oil to be filled. It is connected to the inlet 3a of the pressurized storage tank 3 via a first connecting pipe 13a. The oil in the storage basin 13 is added to the pressurized storage tank 3 via the first connecting pipe 13a under the action of the oil pump 15. The pressurized storage tank 3 is a tank with a scale. When the liquid level in the tank is lower than a preset value, the oil in the storage basin 13 can be automatically replenished, improving the automation level of the equipment and reducing the workload of manually adding oil. The oil drain basin 14 collects excess oil during the filling process.

[0038] The pressurized storage tank 3 has an exhaust port 3b and a pressurization port 3c at its top. The pressurization port 3c is connected to an external pressurization device (not shown) for pressurizing the oil in the pipe. The pressurized storage tank 3 has an oil inlet 3d at its bottom, which is connected to a second connecting pipe 3e. A flow meter 5 is installed on the second connecting pipe 3e to detect the liquid flow rate in the second connecting pipe 3e. In this embodiment, the flow meter 5 is a high-precision, low-flow-rate flow meter to adapt to applications with very small oil pipe diameters. The flow rate value detected by the flow meter 5 is displayed in real time on the display screen of the operation panel 12.

[0039] Vacuum pump 4 is used for venting, completely purging the air from the sealed shaped tube 100 and the oil filling fixture by drawing a vacuum. The vacuum degree detection device 6 detects the vacuum degree of the filling pipeline (which includes at least the oil supply pipeline within the filling fixture and the pipeline within the oil supply connector) to determine if the air has been completely removed. Vacuum pump 4 is connected to the third connecting pipe 4a, the other end of which is connected to the exhaust port 11a of the gas-liquid separator 11. The gas-liquid separator 11 utilizes the difference in specific gravity between gas and liquid to achieve gas-liquid separation; the lower-density gas is drawn from the top, while the higher-density liquid settles at the bottom. A drain port 11b is provided at the bottom of the gas-liquid separator 11. Liquid generated during the evacuation process undergoes gas-liquid separation within the separator 11 and is discharged from the drain port 11b. In a preferred embodiment, the gas-liquid separator protects the vacuum pump, preventing backflow of oil during vacuuming and thus effectively increasing its service life. Furthermore, by incorporating a vacuum holding function, the airtightness of the high-pressure stress sensing element can be detected simultaneously. A fourth connecting pipe 11c is connected to the inlet at the bottom of the gas-liquid separator 11.

[0040] Combination Figure 2 , Figure 4 , Figure 5 and Figure 6As shown, the oil filling clamping fixture 2 in this embodiment includes an oil filling fixing seat 2-1, a plug 2-2, a plug pressing drive unit 2-3, a pressure rod 2-4, and a bracket 2-5. Both ends of the connector 102 are open (102a, 102b) along the axial direction. The one-way valve 103 inside the connector 102 ensures that liquid can only flow from the first port 102a to the second port 102b of the connector 102. Based on the flow direction of the liquid inside the connector 102, the first port 102a of the connector 102 is used as the oil filling port.

[0041] The oil filling base 2-1 and the plug 2-2 are arranged vertically opposite each other and can move vertically relative to each other. The oil filling base 2-1 is fixed on the operating table 1-1 of the frame 1. The oil filling base 2-1 is provided with an oil delivery connector 2-6, the top of which extends upward from the top surface of the oil filling base 2-1. The connector 102 of the high-pressure stress sensing element is installed on the oil filling base 2-1, and the oil delivery connector 2-6 is inserted into the connector 102 through the oil filling port. In this embodiment, the oil delivery connector 2-6 is a straight pipe, and a sealing ring 2-7 and a retaining ring 2-8 are provided between the oil delivery connector 2-6 and the oil filling base 2-1. An oil delivery pipeline 2-1a is machined inside the oil filling base 2-1, which is connected to the pipeline inside the oil delivery connector 2-6, allowing oil to be delivered to the connector 102 through the oil delivery connector 2-6. The oil pipeline 2-1a is connected to the second connecting pipe 3e. The oil in the pressurized storage tank 3 enters the connector 102 through the second connecting pipe 3e, the oil pipeline 2-1a, and the oil connector 2-6, and then flows to the sealed special-shaped pipe 100 through the oil pipeline 101.

[0042] The plug 2-2 is used to seal the second port 102b of the connector 102. In this embodiment, the plug 2-2 is a cover structure that can cover the end of the connector 102 where the second port 102b is located. The cover structure of the plug, which covers the end of the connector 102, provides better sealing compared to a plug structure. Under the control of the plug pressing drive unit 2-3, the plug 2-2 can move up and down. When it moves down, it covers the connector 102 and seals the second port 1-2. When it moves up, it moves away from the connector 102. In this embodiment, the plug pressing drive unit 2-3 is a cylinder, which is mounted on a bracket 2-5. The bracket 2-5 is set on the operating table 1-1 of the frame 1. The piston rod and the pressure rod 2-4 of the cylinder are connected, so that when the cylinder is actuated, it drives the plug 2-2 to move up and down. Optionally, in this embodiment, a rubber pressure sleeve 2-9 is provided between the pressure rod 2-4 and the plug 2-2. The rubber pressure sleeve 2-9 can play a certain buffering role when the plug and the connector 102 are connected.

[0043] The oil filling mounting base 2-1 is also equipped with a drain pipe (not shown) that connects to the oil delivery connector 2-6. The drain pipe is connected to the fifth connecting pipe 14a, which drains the oil discharged through the drain pipe into the oil drain basin 14. A drain valve 9 is installed on the fifth connecting pipe 14a and is used to control the opening and closing of the fifth connecting pipe 14a.

[0044] Oil pipeline 2-1a is connected to the second connecting pipe 3e via a tee pipe 2-10. A liquid flow valve 8 is installed between the second connecting pipe 3e and the tee pipe 2-10 to control the opening and closing of the second connecting pipe 3e. Of the three ports of the tee pipe 2-10, one is connected to the oil pipeline 2-1a, one is connected to the second connecting pipe 3e, and the third is connected to the fourth connecting pipe 11c. A vacuum flow valve 7 is installed on the fourth connecting pipe 11c to control its opening and closing. A detection switch 10 is installed between the tee pipe 2-10 and the fourth connecting pipe 11c.

[0045] The following description, in conjunction with the accompanying drawings, explains the method for filling a high-pressure stress-resistant sensing element using the filling device of this embodiment.

[0046] First, the connector 102 of the high pressure stress sensing element is installed on the filling fixing base 2-1. The second end of the connector 102 is sleeved on the top of the oil delivery connector 2-6. The plug pressing drive unit 2-3 controls the plug 2-2 to be sleeved downward on the first end of the connector 102 to seal the second port 102b of the connector 102.

[0047] Control the vacuum valve 7 to the open state, start the vacuum machine 4, exhaust the air through the vacuum machine 4, and monitor the air tightness and vacuum level in the circuit through the vacuum detection device 6; the exhaust time can be preset.

[0048] After exhausting the air, close vacuum valve 7 to enter the vacuum holding stage;

[0049] After the vacuum is maintained for a certain period of time, the vacuum detection device 6 monitors whether the vacuum degree has reached the set value. If it has, the liquid conduction valve 8 is controlled to be in the conducting state. The oil in the pressurized storage tank 3 flows into the oil delivery joint 2-6 through the second connecting pipe 3e and enters the connector 102. It is then poured into the sealed special-shaped tube 100 through the oil delivery pipe 101. During the filling process, the oil is poured upwards under hydraulic pressure (e.g., Figure 5 (As shown by the upward arrow), the plug 2-2 resists the hydraulic pressure downward under the action of the plug downward driving unit 2-3 (as shown by the upward arrow). Figure 5 (As shown by the downward arrow in the middle), seal the second port of connector 102;

[0050] After filling one sensor element, close the liquid flow valve 8 and open the drain valve 9 to drain excess oil into the drain basin 14 via the fifth connecting pipe 14a for collection and recycling. Remove the connector of the filled sensor element and install the connector of another sensor element for filling. The detection switch 10 controls the vacuum flow valve 7 to be in the conducting state according to a pre-set program logic (such as the vacuum holding time). During the exhaust process via the vacuum machine 4, residual oil in the oil filling fixture can also be sucked up and input into the gas-liquid separator 11 via the fourth connecting pipe 11c. The vacuum machine 4 sucks away the separated air through the third connecting pipe 4a connected to the exhaust port 11a of the gas-liquid separator 11, freeing up more space in the tank to store oil. When the oil in the tank reaches a certain amount, open the drain port 11b to drain the oil for recycling. After vacuum exhaust is complete, repeat the previous steps to fill new sensor elements with oil.

[0051] When a certain amount of oil is used in the pressurized storage tank 3 and the liquid level in the storage tank is lower than the preset value, the oil pump 15 is started to transport the oil in the oil storage basin 13 to the pressurized storage tank 3 through the first connecting pipe 13a. At the same time, the vent 3b at the top of the pressurized storage tank 3 is opened to release the gas in the tank. After the oil is replenished, the vent 3b is closed and the pressurization equipment is started to pressurize the oil through the pressurization port 3c to accelerate the flow of oil from the oil inlet 3d to achieve pressurized filling.

[0052] This invention addresses the issue of high-pressure stress sensing elements with connectors featuring through-holes at both ends. A specific oil-filling clamping fixture is designed to address this problem. During the filling process, a plug blocks the non-filling port and provides sufficient downward pressure to resist the pressure during high-pressure oil filling. This allows for pressurized oil filling while maintaining an airtight seal. Simultaneously, a pneumatic valve (vacuum valve) maintains a vacuum, ensuring a certain degree of vacuum within the sealed, irregularly shaped tube even after the vacuum pump is removed, facilitating oil filling. Combined with a pressurized storage tank, external air pressure enables oil filling. This device requires only manual clamping of the connector for fully automated filling, offering high efficiency, displaying parameters such as vacuum level and filling volume, and is easy to operate.

[0053] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A filling device for high-pressure stress-resistant sensing elements, characterized in that, include: frame; The oil filling clamping fixture is installed on the frame. The oil filling clamping fixture includes an oil filling base, a plug, and a plug pressing drive unit. The plug and the oil filling base are arranged vertically opposite each other and can move vertically relative to each other. The plug pressing drive unit can control the plug to move downward and provide downward pressure to the plug. The oil filling base is provided with an oil delivery connector. The top of the oil delivery connector extends upward from the top surface of the oil filling base. The oil filling base is provided with an oil delivery pipeline communicating with the oil delivery connector and a drain pipeline communicating with the oil delivery connector. The drain pipeline is connected to a fifth connecting pipe. A three-way pipe, one port of which is connected to the oil pipeline, one port of which is connected to the second connecting pipe, and one port of which is connected to the fourth connecting pipe; The pressurized liquid storage tank is installed on the frame. The pressurized liquid storage tank is equipped with an exhaust port, a pressurization port and an oil inlet. The pressurization port is connected to an external pressurization device and the oil inlet is connected to the second connecting pipe. The oil in the pressurized liquid storage tank is input into the oil pipeline through the second connecting pipe. A vacuum machine, which is connected to the fourth connecting pipe; A flow meter for monitoring the liquid flow rate in the second connecting pipe; Vacuum level detection device for monitoring the vacuum level inside the filling pipeline; The drain valve controls the on / off state of the fifth connecting pipe; A liquid-conducting valve that controls the on / off state of the second connecting pipe; A vacuum valve that controls the on / off state of the fourth connecting pipe.

2. The high-pressure stress-resistant sensing element filling device as described in claim 1, characterized in that: It also includes a gas-liquid separator, the fourth connecting pipe is connected to the inlet of the gas-liquid separator, the exhaust port of the gas-liquid separator is connected to the third connecting pipe, and the other end of the third connecting pipe is connected to the vacuum machine.

3. The high-pressure stress-resistant sensing element filling device as described in claim 1, characterized in that: The pressurized storage tank is installed at a height higher than the oil filling clamping fixture.

4. The high-pressure stress-resistant sensing element filling device as described in claim 1, characterized in that: It also includes an oil storage basin and an oil pump. The oil storage basin is connected to the oil inlet of the pressurized liquid storage tank through a first connecting pipe. The oil in the oil storage basin is added to the pressurized liquid storage tank through the first connecting pipe under the action of the oil pump.

5. The high-pressure stress-resistant sensing element filling device as described in claim 1, characterized in that: It also includes an oil drain basin, into which the fifth connecting pipe drains the oil.

6. The high-pressure stress-resistant sensing element filling device as described in claim 1, characterized in that: The high-pressure stress sensing element includes a sealed shaped tube, a connector, and an oil supply pipe connecting the sealed shaped tube and the connector; the connector is provided with a one-way valve, and the connector has a first port and a second port at both axial ends, through which liquid flows from the first port to the second port; the connector is mounted on the oil filling base, and the oil supply connector extends from the top of the oil filling base and enters the connector from the first port; the plug is used to seal the second port.

7. The high-pressure stress-resistant sensing element filling device as described in claim 6, characterized in that: The plug is a cover-type connector that covers the outer periphery of the end of the connector.

8. The high-pressure stress-resistant sensing element filling device as described in claim 1, characterized in that: The plug pressing drive unit is a cylinder, which is mounted on a bracket fixed to the frame. The piston rod of the cylinder is connected to a pressure rod, which is connected to the plug. A rubber pressure sleeve is provided between the pressure rod and the plug.

9. The high-pressure stress-resistant sensing element filling device as described in claim 1, characterized in that: An operating table is provided on the frame, and the oil filling clamping fixture is set on the operating table.

10. A method for filling using the high-pressure stress-sensing element filling apparatus as described in any one of claims 1 to 9, characterized in that, Includes the following steps: The connector of the high-pressure stress sensing element is installed onto the filling fixture, and the plug seals the second port of the connector. Control the vacuum valve to the open state, start the vacuum machine to exhaust air, and monitor the airtightness and vacuum level in the filling pipeline; After exhausting the air, close the vacuum valve to enter the vacuum holding stage; After the vacuum is maintained for a certain period of time, the vacuum detection device monitors whether the vacuum degree has reached the set value. If it has, the liquid conduction valve is controlled to be in the conduction state, and the oil flows from the pressurized storage tank into the oil delivery joint and enters the connector. It then flows through the oil delivery pipe of the high pressure stress sensing element into the sealed special-shaped tube of the high pressure stress sensing element. After filling a sensor element, close the liquid inlet valve and open the drain valve to drain the excess oil. Remove the connector of the pre-filled high-pressure stress sensing element, install the connector of another high-pressure stress sensing element, and repeat the above steps to fill the new high-pressure stress sensing element with oil.

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