Sealing force test platform based on valve type asteroid sample tube

Abstract

This invention discloses a sealing force testing platform for valve-type spherical soil sample collection tubes, comprising an adjustable temperature inner liner, several traction modules, a heat-insulated support platform, and a mounting base. The outer wall of the adjustable temperature inner liner is wound with a heat-conducting hose, through which a high-low temperature circulating liquid is introduced to simulate high-low temperature conditions in a testing environment. A PT100 temperature sensor is used to collect the internal temperature in real time, ensuring a stable and controllable testing environment. Each traction module uses a dual-stepper motor-driven electric cylinder as its power unit, forming a differential traction structure with fixed pulleys and carbon fiber ropes. Combined with the geometric constraints of the valve installation, the valves are precisely pulled, and the sealing force is collected in real time simultaneously. The support platform is made entirely of heat-insulating material, elevating the inner liner and aligning the sample tube with the traction modules to reduce temperature conduction interference. This invention can simulate different temperature environments and simultaneously measure the sealing force-opening characteristic curves of each valve in a multi-valve sealing sample tube, offering advantages such as strong compatibility, high testing accuracy, and comprehensive data.

Description

Technical Field

[0002] This invention relates to a sealing performance testing device, specifically a sealing force testing platform for valve-type spherical soil collection sample tubes, which can measure the sealing force of valve-type sample tubes under different temperature environments. Background Technology

[0004] Astrospheric regolith collection is a crucial part of extraterrestrial exploration missions. my country's Chang'e 5 and Chang'e 6 missions successfully collected lunar regolith and brought it back to Earth. In these missions, the extraterrestrial probe needs to collect the regolith samples into sample tubes, then remove and seal the tubes. Because active sealing is complex, requires additional sealing mechanisms, and adds to the probe's weight, many sample tube designs employ passive sealing—the tubes are automatically sealed by an elastic sealing component upon removal after sample collection. Considering the sample tubes need to carry the regolith samples on a long interplanetary journey, enduring acceleration, deceleration, and turbulence during reentry, the sealing component needs a certain sealing force redundancy to ensure no leakage. Therefore, the sealing force is critical to the safe return of the regolith samples and is a vital indicator of the sample tube's airtightness. A commonly used passive sealing sample tube design is the valve-type sample tube. As a design with excellent sealing performance, it ensures that the regolith does not come into direct contact with organic matter, thus preventing sample contamination. The sealing mechanism of this type of sample tube has multiple valves, which requires the corresponding sealing force testing platform to apply loads accurately and symmetrically to obtain the most accurate sealing force performance indicators. Summary of the Invention

[0006] The technical problem to be solved by this invention is to develop a testing platform that can measure the sealing force of valve-type passively sealed sample tubes under different temperature conditions.

[0007] This invention relates to a sealing force testing platform based on a valve-type spherical soil collection sample tube, comprising an adjustable temperature inner liner, a traction module, and a support platform, all mounted on a horizontal base plate.

[0008] The support platform is used to support the adjustable temperature inner liner and set the height of the adjustable temperature inner liner at a preset height.

[0009] The adjustable temperature inner liner includes an inner liner body, an inner liner top cover, and a heat-conducting hose. The inner liner body and the inner liner top cover are both rotating structures coaxially connected to form an integral cylindrical sample tube receiving chamber, where the sample tube to be tested is placed coaxially. The lower circumferential part of the inner liner body has screw holes for mounting set screws to securely fasten the sample tube to the chamber.

[0010] The inner liner cover has fine slits evenly arranged circumferentially along the axial direction of the inner liner cover sidewall. The number of these slits is equal to the number of valves on the valve-type spherical soil collection tube being tested, and the circumferential position of each valve on the sample tube being tested corresponds to the position of each slit.

[0011] A heat-conducting hose is wrapped around the outer perimeter of the inner sample tube receiving chamber. High and low temperature liquids are introduced into the heat-conducting hose to change the internal temperature of the sample tube receiving chamber, and the internal temperature of the sample tube receiving chamber is detected by a temperature sensor installed on the inner body.

[0012] The number of traction modules is equal to the number of valves in the tested valve-type spherical soil sampling tube. They are evenly distributed circumferentially around the adjustable-temperature inner liner, with their circumferential positions corresponding to the circumferential slits on the inner liner's top cover. These modules are used to apply tension to the valves of the tested valve-type spherical soil sampling tube. The traction modules include a height-adjustable electric cylinder, a traction electric cylinder, a fixed pulley, a tension sensor, a fisheye bearing, and a traction rope.

[0013] Both the height-adjusting electric cylinder and the traction electric cylinder have vertically arranged piston rods and are electric cylinders with L-shaped adapter plates.

[0014] The height-adjustable electric cylinder has a fixed pulley cantilever bracket on one side of the L-shaped adapter plate and the piston rod end. The end of the fixed pulley cantilever bracket is fixed to the L-shaped adapter plate; the front end is located outside the height-adjustable electric cylinder and is equipped with a fixed pulley.

[0015] The L-shaped adapter plate of the traction electric cylinder is slidably connected to the outer wall of the electric cylinder and a tension sensor mounting bracket is fixedly installed on one side. A fisheye bearing is fixedly installed at the bottom of the tension sensor mounting bracket. The fisheye bearing is connected to the lower end of the tension sensor. A force measuring ring is assembled at the upper end of the tension sensor.

[0016] One end of the carbon fiber rope is fixed to the force-measuring ring, and the other end goes upwards past the fixed pulley and then reverses direction, passing radially through the sample tube receiving chamber and through the corresponding circumferential slit on the inner liner cover into the sample tube receiving chamber, and is fixed to the valve tip opening at the corresponding circumferential position. Thus, the height-adjusting electric cylinder and the traction electric cylinder perform a traction action, applying an outward load to the traction rope, thereby pulling the valve outwards through the traction rope.

[0017] The advantages of this invention are:

[0018] 1. The sealing force testing platform for the sample tube of the present invention can meet the sealing force testing needs of various sealing components and is compatible with sample tubes and sealing components of different types and sizes.

[0019] 2. The sealing force testing platform for the sample tube of the present invention can adaptively adjust and correct clamping errors to ensure testing accuracy, thereby saving time and economic costs for the research and development and selection of sample tubes for the packaging of the sample tube.

[0020] 3. This invention can test the sealing force of sample tubes at different temperatures and simulate the changes in sealing force of sample tubes under various extreme temperature conditions in outer space, providing objective testing basis for the research and development of star soil encapsulated sample tubes. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of the sealing force testing platform based on the valve-type star soil collection sample tube of the present invention;

[0023] Figure 2 This is an exploded view of the adjustable temperature inner liner structure in the sealing force testing platform based on the valve-type star soil collection sample tube of the present invention.

[0024] Figure 3 This is a schematic diagram of the tension module structure in the sealing force testing platform based on the valve-type star soil collection sample tube of the present invention;

[0025] Figure 4 This is a schematic diagram of the sealing force measurement method of the sealing force testing platform based on the valve-type star soil collection sample tube;

[0026] Figure 5 This is a geometric schematic diagram of the electric cylinder position adjustment principle for the traction module.

[0027] In the picture:

[0028] 1-Adjustable temperature inner liner; 101-Inner liner body; 102-Inner liner top cover; 102a-Slit; 103-Insulated viewing window glass; 104-Viewing window frame; 105-PT100 temperature sensor; 106-Set screw; 107-Heat conductive hose;

[0029] 2-Tethering module; 201-Height adjustment electric cylinder; 202-Tethering electric cylinder; 203-Fixed pulley cantilever frame; 204-Fixed pulley; 205-Force sensor mounting bracket; 206-Force sensor; 207-Carbon fiber rope; 208-Fisheye bearing; 209-Force measuring ring;

[0030] 3-Support platform;

[0031] 4. Install the base plate;

[0032] 5-Valve. Detailed Implementation

[0034] The present invention will now be described in further detail with reference to the accompanying drawings.

[0035] This invention relates to a sealing force testing platform based on a valve-type asteroidal soil sampling tube, comprising an adjustable temperature inner liner 1, a tension module 2, a support platform 3, and a mounting base 4, as shown below. Figure 1 As shown.

[0036] The support platform 3 is made of heat-insulating material and has a cylindrical structure. It is fixed to the middle of the mounting base plate 4 by means of a bottom flange and screws. An adjustable temperature inner liner 1 is installed on the top of the support platform 3, and the height of the adjustable temperature inner liner 1 is set to a preset height by means of the support platform 3.

[0037] The adjustable temperature inner liner 1 consists of an inner liner body 101, an inner liner top cover 102, a heat-insulating viewing window 103, a viewing window frame 104, a PT100 temperature sensor 105, a set screw 106, and a heat-conducting hose 107. Figure 2 As shown.

[0038] Both the inner liner body 101 and the inner liner top cover 102 are rotating structures made of brass with equal inner diameters. The inner liner top cover 102 and the inner liner body 101 are coaxially arranged vertically and are coaxially connected and fixed by bolts through connecting flanges designed circumferentially at the bottom of the inner liner top cover 102 and the top of the inner liner body 101, forming an integral cylindrical sample tube receiving chamber. Its inner diameter and height are larger than the tested valve-type asteroidal soil sampling tube (tube body and top cover), allowing the tested valve-type asteroidal soil sampling tube to be inserted into the sample tube receiving chamber through the opening on the top surface of the inner liner top cover 102, and the entire tube is located inside the sample tube receiving chamber. At the same time, the lower circumferential part of the inner liner body 101 has three screw holes, each threaded with a set screw 106. Thus, when the tested valve-type asteroidal soil sampling tube is placed inside the inner liner body 101, tightening the set screws 106 can coaxially and firmly fix the tested valve-type asteroidal soil sampling tube at the center of the sample tube receiving chamber.

[0039] The inner liner cover 102 has N slits 102a, each 12 mm long and 2 mm wide, evenly arranged circumferentially along its axis 102. The number N of these slits 102a is equal to the number of valves 5 in the valve-type spherical soil sampling tube under test. After the valve-type spherical soil sampling tube is installed, the circumferential position of each valve 5 corresponds to the position of each slit 102a. N carbon fiber ropes can then pass through each slit 102a and be radially tied to the small holes at the tips of each valve 5. Therefore, multiple inner liner covers 102 with different numbers of slits 102a can be designed, allowing for the selection of an inner liner cover 102 with the corresponding number of slits 102a based on the number of valves 5 in the valve-type spherical soil sampling tube under test, for sealing force testing. Because the front end of the carbon fiber rope needs to be horizontal, and the height of the fixing point between the carbon fiber rope and the valve 5 will change during the opening of the valve 5, the position of the rope passing through the outer wall of the inner bladder will also rise and fall accordingly. Therefore, a certain length of slit needs to be provided to allow for the undulation.

[0040] A heat-insulating viewing window 103 and a viewing window frame 104 are coaxially arranged from bottom to top on the top surface of the inner liner cover 102. The viewing window frame 104 is circumferentially connected and fixed to the inner liner cover 102 by screws, pressing the heat-insulating viewing window 103 tightly to the top surface of the inner liner cover 102, and the radial displacement of the heat-insulating viewing window 103 is restricted by the shoulder of the viewing window frame 104. This allows the tester to observe the internal condition of the sample tube containing chamber through the heat-insulating viewing window 103.

[0041] A heat-conducting flexible hose 107 is wound around the outer perimeter of the inner liner sample tube receiving chamber. High and low temperature liquids can be introduced into the hose 107 to change the internal temperature of the sample tube receiving chamber. It is threadedly connected to a PT100 temperature sensor at the bottom of the inner liner body 101, allowing the PT100 temperature sensor to detect and read the internal temperature of the sample tube receiving chamber, thus enabling feedback regulation of the internal temperature. When winding the heat-conducting flexible hose 107, it is necessary to maximize its coverage area while avoiding holes in the sample tube receiving chamber. Therefore, for the sample tube receiving chamber with the above structure, in this embodiment, the heat-conducting flexible hose 107 is first wound multiple times on the inner liner cover 102 between the slit 102a and the top of the inner liner cover 102. The inlet end extends downwards through adjacent slits and passes through the perforations in the inner liner body 101 and the inner liner cover 102, continuing downwards...

[0042] The bottom of the adjustable temperature inner liner 1 of the above structure is connected to the top flange of the aforementioned support platform 3, and the two are coaxially fixed together by bolts.

[0043] like Figure 3 As shown, the tension module 2 is used to apply tension to the valve 5 of the tested valve-type spherical soil sampling tube. Therefore, the number of tension modules 2 is equal to the number of valves 5 in the tested valve-type spherical soil sampling tube, which is N. The N tension modules 2 are evenly distributed around the adjustable temperature inner liner 1 in a circumferential direction, and their circumferential positions correspond to the positions of the circumferential slits 102a of the aforementioned inner liner cover 102. In this embodiment, the tested valve-type spherical soil sampling tube has 3 valves 5, so an inner liner cover 102 with three slits 102a is used in conjunction with 3 tension modules for testing.

[0044] like Figure 3 As shown, the traction module 2 is mainly composed of a height-adjusting electric cylinder 201 and a traction electric cylinder 202, both of which are fixed to the mounting base plate 4. The piston rods of both cylinders are perpendicular to the mounting base plate 4 and are driven by a stepper motor, allowing for quantitative control of the piston rod's extension and retraction length. Simultaneously, the height-adjusting electric cylinder 201 and the traction electric cylinder 202 are arranged radially along the circumference of the traction module 2, with the height-adjusting electric cylinder 201 adjacent to the adjustable-temperature inner liner 1.

[0045] Both the height-adjusting electric cylinder 201 and the pulling electric cylinder 202 mentioned above are electric cylinders with L-shaped adapter plates. That is, the fixed side of the L-shaped adapter plate is fixed to the end of the piston rod on the outside of the cylinder body, and the other side is the sliding side, which is slidably connected to the side wall of the cylinder body. Thus, the two sides of the L-shaped adapter plate provide two mutually perpendicular mounting reference surfaces for the electric cylinder.

[0046] A fixed pulley cantilever 203 is provided on the fixed side of the L-shaped adapter plate of the height adjustment electric cylinder 201; the end of the fixed pulley cantilever 203 is fixedly installed on the fixed side of the L-shaped adapter surface by screws; the front end of the fixed pulley cantilever 203 is a U-shaped connecting end, located outside the height adjustment electric cylinder 201; a fixed pulley 204 is provided inside the U-shaped connecting end, and the two ends of the wheel axle of the fixed pulley 204 are respectively connected to the two sides of the U-shaped connecting end by bearings.

[0047] The L-shaped adapter plate of the traction electric cylinder 202 is fixedly mounted with a tension sensor mounting bracket 205 by isomorphic screws. A fisheye bearing 208 is fixedly mounted at the bottom of the tension sensor mounting bracket 205. The fisheye bearing 208 is connected to the lower end of the tension sensor 206. A force measuring ring 209 is assembled at the upper end of the tension sensor 206.

[0048] One end of the carbon fiber rope 207 is fixed to the force-measuring ring 209, and the other end goes upward past the fixed pulley 204 and then reverses direction, passing radially through the circumferential slit 201a of the inner liner cover 102 into the sample tube receiving chamber, and is fixed to the corresponding circumferential opening at the tip of the valve 5. Through the design of the installation positions of each part and the height of the support platform 3, combined with the lifting and lowering adjustment of the piston rod of the height-adjusting electric cylinder, the carbon fiber rope 207 is ultimately kept in a taut state. A section of the carbon fiber rope 207 between the fixed pulley 204 and the force-measuring ring 209 is perpendicular to the mounting base plate, while another section of the carbon fiber rope 207 between the fixed pulley 204 and the valve 5 is parallel to the mounting base plate. Figure 4 As shown.

[0049] Thus, the height adjustment electric cylinder 201 and the traction electric cylinder 202 perform the traction action, applying an outward load to the carbon fiber rope 207, and pulling the valve 5 outward through the carbon fiber rope 207.

[0050] The pulling action of the aforementioned height-adjusting electric cylinder 201 and the pulling electric cylinder 202 is achieved through a differential mechanism, ensuring that the section of carbon fiber rope 207 between the fixed pulley 204 and the valve 5 remains horizontal during the pulling process. Specifically:

[0051] like Figure 5As shown, let R be the distance between the sample tube valve hinge and the opening at the tip of valve 5, q be the angle between the lines connecting them and the vertical direction, r be the radius of the fixed pulley 204, L be the total length of the carbon fiber rope 207, and L1 be the horizontal distance between the sample tube valve hinge and the axis of rotation of the fixed pulley 204. To ensure that the carbon fiber rope 207 of the traction module is taut and that the section of carbon fiber rope 207 between the fixed pulley 204 and valve 5 is horizontal, the height adjustment electric cylinder 201 needs to adjust the height of the fixed pulley 204 so that the vertical distance between the sample tube valve hinge and the axis of rotation of the fixed pulley 204 is... Furthermore, to pull the electric cylinder 202, the height of the force sensor 206 and the force-measuring ring 209 needs to be adjusted so that the distance between the end of the carbon fiber rope 207 connected to the force-measuring ring 209 and the shaft of the fixed pulley 204 in the vertical direction is... Accordingly, by actively adjusting H1 and H2 through the height-adjusting electric cylinder 201 and the traction electric cylinder 202, the opening degree of valve 5 can be controlled, specifically as follows:

[0052] .

[0053] This invention provides a sealing force testing platform for valve-type asteroid sample collection tubes, compatible with sample tubes of varying numbers and sizes of valves. The following description uses a three-valve sample tube sealing force test as an example to illustrate the usage of this invention:

[0054] First, prepare for the test by threading the ends of the carbon fiber ropes of each traction module through the slits and securing them to the corresponding valve tip openings on the circumferential direction of the sample tube. Then, insert the sample tube into the sample tube receiving chamber and secure it with set screws. Simultaneously, adjust each traction module 2 to ensure that each carbon fiber rope 207 is just taut and that the carbon fiber rope 207 passes vertically through the fixed pulley 204 and connects to the valve 5 horizontally. To test the sealing force under extreme temperature conditions, simply pass the appropriate high or low temperature liquid into the heat-conducting hose 107 and read the value from the PT100 temperature sensor 105. Once the temperature is suitable, the test can begin.

[0055] During testing, all traction modules 2 are controlled to synchronously perform traction actions, which slowly pulls up all valves 5. During this process, the sealing force-opening characteristic curve of each valve 5 is measured by the tension sensor 206. At the same time, the experimenter can observe the sample tube through the viewing window. After the experiment, each traction module 2 is relaxed, and the sample tube can be removed after the adjustable temperature inner liner 1 returns to room temperature.

Claims

1. A sealing force testing platform based on a valve-type spherical soil sampling tube, characterized in that: The adjustable temperature inner liner, the tensioning module, and the support platform are all mounted on a horizontal base plate. The support platform is used to support the adjustable temperature inner liner and set the height of the adjustable temperature inner liner at a preset height; The adjustable temperature inner liner includes an inner liner body, an inner liner top cover, and a heat-conducting hose; wherein, the inner liner body and the inner liner top cover are both rotating structures coaxially connected to form an integral cylindrical sample tube receiving chamber, in which the sample tube to be tested is placed coaxially; the lower part of the inner liner body has screw holes in the circumferential direction for installing set screws to tighten and fix the sample tube to be tested. The inner liner cover has fine slits evenly arranged circumferentially along the axial direction of the inner liner cover sidewall. The number of these fine slits is equal to the number of valves in the valve-type spherical soil collection tube being tested, and the circumferential position of each valve on the sample tube being tested corresponds to the position of each fine slit. A heat-conducting hose is wrapped around the outer perimeter of the inner sample tube receiving chamber. High and low temperature liquids are introduced into the heat-conducting hose to change the internal temperature of the sample tube receiving chamber, and the internal temperature of the sample tube receiving chamber is detected by a temperature sensor installed on the inner body. The number of the traction modules is equal to the number of valves in the tested valve-type spherical soil sampling tube. They are evenly distributed around the adjustable temperature inner liner, with their circumferential positions corresponding to the circumferential slits on the inner liner cover. They are used to apply tension to the valves of the tested valve-type spherical soil sampling tube. The traction module includes a height-adjustable electric cylinder, a traction electric cylinder, a fixed pulley, a tension sensor, a fisheye bearing, and a traction rope. Both the height-adjusting electric cylinder and the traction electric cylinder have vertically arranged piston rods and are electric cylinders with L-shaped adapter plates. Among them, a fixed pulley cantilever frame is provided on the side of the L-shaped adapter plate of the height adjustment electric cylinder and the piston rod end; the end of the fixed pulley cantilever frame is fixed to the L-shaped adapter plate; the front end is located outside the height adjustment electric cylinder and is equipped with a fixed pulley. A tension sensor mounting bracket is fixedly installed on one side of the L-shaped adapter plate of the traction electric cylinder that is slidably connected to the outer wall of the electric cylinder. A fisheye bearing is fixedly installed at the bottom of the tension sensor mounting bracket. The fisheye bearing is connected to the lower end of the tension sensor. A force measuring ring is assembled at the upper end of the tension sensor. One end of the carbon fiber rope is fixed to the force-measuring ring, and the other end goes upward around the fixed pulley and then reverses direction. It passes through the circumferential slit on the inner liner cover and enters the sample tube receiving chamber radially, and is fixed to the valve tip opening at the corresponding circumferential position. Thus, the height adjustment electric cylinder and the traction electric cylinder perform the traction action, applying an outward load to the traction rope, and pulling the valve outward through the traction rope.

2. The sealing force testing platform based on the valve-type star soil collection sample tube as described in claim 1, characterized in that: The support platform is made of heat-insulating material and has a cylindrical structure.

3. The sealing force testing platform based on the valve-type star soil collection sample tube as described in claim 1, characterized in that: Both the inner liner body and the inner liner cover are made of brass.

4. The sealing force testing platform based on the valve-type star soil collection sample tube as described in claim 1, characterized in that: The top surface of the inner liner cover is equipped with a heat-insulated viewing window glass, which facilitates observation of the inside of the sample tube holding chamber. The viewing window glass is pressed and fixed to the top surface of the inner liner cover by the viewing window frame.

5. The sealing force testing platform based on the valve-type star soil collection sample tube as described in claim 1, characterized in that: The traction action of the height-adjusting electric cylinder and the traction electric cylinder is achieved through a differential mechanism between the two, ensuring that the carbon fiber rope is taut and that the section of traction rope between the fixed pulley and the valve remains horizontal throughout the traction process; specifically: The height-adjustable electric cylinder requires adjusting the height of the fixed pulley to ensure the vertical distance between the sample tube valve hinge and the fixed pulley's axis. Furthermore, the height of the force sensor and the force-measuring ring needs to be adjusted when pulling the electric cylinder, so that the distance between the end of the carbon fiber rope connected to the force-measuring ring and the shaft of the fixed pulley in the vertical direction is... ; Where R is the distance between the sample tube valve hinge and the valve tip opening; L is the total length of the traction rope; θ is the valve opening; r is the radius of the fixed pulley; and L1 is the horizontal distance between the sample tube valve hinge and the fixed pulley axis.

6. The sealing force testing platform based on the valve-type star soil collection sample tube as described in claim 5, characterized in that: The valve opening is controlled by actively adjusting H1 and H2 using a height-adjusting electric cylinder and a traction electric cylinder, with the specific relationship as follows: 。 7. The testing method of the sealing force testing platform based on the valve-type star soil collection sample tube as described in claim 1, characterized in that: First, prepare for the test by threading the front end of the carbon fiber rope of each traction module through the slit on the side wall of the sample tube receiving chamber and then fastening it to the corresponding valve tip opening of the three-lobed sample tube. Then, insert the three-lobed sample tube into the sample tube receiving chamber and fix it with the set screw. At the same time, adjust each traction module to make each carbon fiber rope taut and ensure that the carbon fiber rope passes vertically through the fixed pulley and then connects to the valve in the horizontal direction. During the test, all traction modules are controlled to perform traction actions synchronously to pull up all valves. During the process, the sealing force-opening characteristic curve of each valve is obtained based on the data measured by the tension sensor. At the same time, the experimenter can observe the sample tube through the window. After the experiment is completed, each traction module is relaxed and the sample tube is removed after the adjustable temperature inner liner returns to normal temperature.

8. The testing method of the sealing force testing platform based on the valve-type star soil collection sample tube as described in claim 7, characterized in that: To test the sealing force under extreme temperature conditions, the corresponding high and low temperature liquids are introduced into the heat-conducting hose, and the temperature sensor values ​​are read. The test can begin once the temperature reaches the set temperature.

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