A method for measuring contact forces during a load launch process

Abstract

A kind of contact force measurement method of load launch process, comprising: step one: install load ring assembly on the mouth piece of launch tube through shear sensor;Step two: adjust the concentricity of load ring assembly and launch tube, adjust the levelness of shear sensor;Step three: set stress measuring element on shear sensor;Step four: hang standard weight on load ring assembly, fit linear variation curve between the signal of stress measuring element and the total mass of standard weight;Step five: place launch tube in water and launch load, obtain the contact force corresponding to load ring assembly by linear variation curve between the signal data of stress measuring element and the total mass of standard weight, accurately measure the contact force between the mouth end of launch tube and load during launch process, provide test data support for the establishment of contact force mathematical model of carrier platform and load separation process, improve the accuracy and reliability of load launch trajectory design.

Description

Technical Field

[0001] This invention relates to the field of measuring device technology, and in particular to a method for measuring contact force during load launch. Background Technology

[0002] Underwater unmanned platforms possess high stealth capabilities and can carry varying quantities and types of payloads to perform diverse combat missions, including raids and reconnaissance. During payload launch, the payload and platform interact due to their constraint relationship, generating contact forces. These contact forces influence the initial motion state of the payload upon separation, thereby affecting the ballistic stability of the launch trajectory and directly impacting the success or failure of the combat mission.

[0003] Accurate modeling of the contact force during the payload launch process is a key problem that needs to be solved in the research. The modeling process requires a large amount of contact force test data. Therefore, designing a measuring device that can measure the change of contact force during the separation process of the payload and the platform is of great value. Summary of the Invention

[0004] To address the shortcomings of existing production technologies, the applicant provides a method for measuring contact force during payload launch. This method accurately measures the contact force between the launch tube tip and the payload during launch, providing experimental data support for establishing a mathematical model of the contact force during the separation process between the launch vehicle platform and the payload, thereby improving the accuracy and reliability of payload launch trajectory design.

[0005] The technical solution adopted in this invention is as follows:

[0006] A method for measuring contact force during payload launch includes the following steps:

[0007] Step 1: Install the nozzle mounting component at the outlet of the launch tube. Install the force measuring ring assembly on the nozzle mounting component through the shear force sensor. The minimum inner diameter of the force measuring ring assembly is equal to the inner diameter of the launch tube. The two shear force sensors are symmetrically arranged about the diameter of the launch tube, and the direction of the line connecting the centers of the shear force sensors passes through the axis of the launch tube.

[0008] Step 2: Adjust the concentricity of the force ring assembly and the launching tube to ensure that the force ring assembly and the launching tube are concentric, and adjust the levelness of the two shear force sensors;

[0009] Step 3: Set up stress measurement elements on the shear force sensor;

[0010] Step 4: Suspend the standard weight on the force ring assembly. The downward direction of the standard weight is perpendicular to the direction of the line connecting the centers of the two shear force sensors. Record the signal change of the stress measuring element. Change the signal output of the stress measuring element by changing the total mass of the standard weight. Fit the linear change curve between the signal of the stress measuring element and the total mass of the standard weight.

[0011] Step 5: After the load is loaded, place the launch tube in the water and launch the load. The processor receives and records the signal data of the stress measurement element during the load launch process. The contact force on the corresponding force ring assembly is obtained by the linear change curve between the signal and the total mass of the standard weight.

[0012] Its further technical solution lies in:

[0013] When using a dry launch payload:

[0014] In step one, when installing the force ring assembly, a sealing ring is installed between the force ring assembly and the end of the transmitting tube;

[0015] In step five, after the load is in place, the sealing plate is installed on the outside of the force measuring ring assembly by pressing the sealing ring, so that the sealing plate, the force measuring ring assembly and the launching tube form a closed space. After the airtightness test is performed to confirm that the seal is good, the launching tube is then placed in water.

[0016] The sealing sheet is an aluminum film.

[0017] When measuring contact force in the vertical direction, the two shear force sensors are set in the horizontal direction.

[0018] When measuring contact force in the horizontal direction: the two shear force sensors are set in the vertical direction.

[0019] In step one: the nozzle mounting piece is ring-shaped and is fixedly installed at the outlet of the launch tube by means of threaded connection.

[0020] The shear force sensor has the following structure: it includes a rectangular block body, one end of which is connected to a pipe mounting component along its length, and the other end of which is connected to a force measuring ring assembly. A weakening groove is provided in the middle of the block body, making the shear force sensor form a parallel beam structure. The two sides of the weakening groove along its length are a first stress concentration surface and a second stress concentration surface, respectively. The center of the shear force sensor is located at the central section of the weakening groove, and the central section is parallel to the first and second stress concentration surfaces. The first and second stress concentration surfaces are used to bear the stress on the shear force sensor when a standard weight is applied.

[0021] The stress measuring element is a strain gauge, which is attached to the first stress concentration surface and the second stress concentration surface. The signal of the stress measuring element is a voltage signal.

[0022] The force measuring ring assembly has the following structure: it includes a force measuring ring body, the inner diameter of which is larger than the inner diameter of the transmitting tube. The force measuring ring body is connected to the tube mounting component through a shear force sensor. A force measuring inner ring is installed on the inner surface of the force measuring ring body. The inner diameter of the middle part of the force measuring inner ring is the same as the inner diameter of the transmitting tube. The inner surfaces at both ends of the force measuring inner ring are provided with transition slopes that cooperate with the inner surface of the force measuring ring body.

[0023] The inner ring for force measurement is made of polytetrafluoroethylene.

[0024] The beneficial effects of this invention are as follows:

[0025] This invention features a compact and reasonable structure and is easy to operate. By installing a force-measuring ring assembly on the launch tube using a shear force sensor, the stress change signal generated by the deformation of the force-measuring ring assembly when it comes into contact with the load during launch is used to measure the contact force between the load and the launch tube during launch. This precise measurement of the contact force between the tube end and the load during launch provides experimental data support for establishing a mathematical model of the contact force during the separation process between the launch vehicle platform and the load, thereby improving the accuracy and reliability of the load launch trajectory design.

[0026] Furthermore, the present invention also has the following advantages:

[0027] (1) By installing a sealing ring between the force ring assembly and the end of the launch tube, and by installing a sealing plate on the outside of the force ring assembly through a press-fit ring, the sealing plate, the force ring assembly and the launch tube form a closed space, which can meet the requirements of the underwater dry launch mode of the load and ensure the water tightness inside the launch tube.

[0028] (2) By setting up shear force sensors in two directions, the contact force at different positions during the load launch process can be measured, further increasing the richness of the measurement data and making the test data support more comprehensive.

[0029] (3) The force measuring inner ring is assembled by the force measuring ring body with an inner diameter greater than that of the launch tube and the force measuring inner ring with an inner diameter equal to that of the launch tube. This makes the force measuring ring assembly structure stable while minimizing the contact position with the load, and more accurately measuring the contact force between the load and the launch tube opening. By setting a transition slope, the load is ensured to contact the force measuring ring without jamming. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of the present invention.

[0031] Figure 2 This is the front view of the present invention.

[0032] Figure 3 This is an axonal sectional view of the present invention (during wet launch).

[0033] Figure 4 This is a cross-sectional view of the present invention.

[0034] Figure 5 This is a cross-sectional view of the present invention (including load 7).

[0035] Figure 6 for Figure 4 Enlarged view of point A in the middle.

[0036] Figure 7 This is the left view (sectional view) of the present invention.

[0037] Figure 8 This is a schematic diagram of the shear force sensor of the present invention.

[0038] Among them: 1. Transmitter tube;

[0039] 2. Shear force sensor; 20. Block body; 21. Weakening groove; 22. First stress concentration surface; 23. Second stress concentration surface;

[0040] 3. Pipe fittings;

[0041] 4. Force measuring ring assembly; 41. Force measuring ring body; 42. Inner force measuring ring; 43. Sealing ring; 44. Transition slope;

[0042] 5. Sealing sheet; 6. Press-fit ring;

[0043] 7. Load. Detailed Implementation

[0044] The specific embodiments of the present invention will now be described with reference to the accompanying drawings.

[0045] Example 1:

[0046] like Figures 1-5 As shown, the method for measuring contact force during payload launch in this embodiment includes the following steps:

[0047] Step 1: Install the nozzle mounting component 3 at the outlet of the launch tube 1. Install the force measuring ring assembly 4 on the nozzle mounting component 3 through the shear force sensor 2. The minimum inner diameter of the force measuring ring assembly 4 is equal to the inner diameter of the launch tube 1. The two shear force sensors 2 are symmetrically arranged about the diameter of the launch tube 1, and the direction of the center line connecting the shear force sensors 2 passes through the axis of the launch tube 1.

[0048] Step 2: Adjust the concentricity of the force measuring ring assembly 4 and the launching tube 1 to make them concentric, and adjust the levelness of the two shear force sensors 2.

[0049] Step 3: Set the stress measurement element on the shear sensor 2.

[0050] Step 4: Suspend the standard weight on the force ring assembly 4. The downward direction of the standard weight is perpendicular to the direction of the line connecting the centers of the two shear force sensors 2. Record the signal change of the stress measuring element. Change the signal output of the stress measuring element by changing the total mass of the standard weight. Fit the linear change curve between the signal of the stress measuring element and the total mass of the standard weight.

[0051] Step 5: After the load 7 is loaded into place, the launching tube 1 is placed in the water and the load 7 is launched. The processor receives and records the signal data of the stress measuring element during the launch of the load 7. The contact force on the corresponding force ring assembly 4 is obtained by the linear change curve between the signal and the total mass of the standard weight.

[0052] Specifically, the processor is the signal acquisition or signal acquisition and processing device needed during measurement.

[0053] The measurement method in this embodiment involves installing a force-measuring ring assembly 4 on the launch tube 1 via a shear force sensor 2. During launch, when the force-measuring ring assembly 4 comes into contact with the load 7, the shear force sensor 2 experiences shear strain. The contact force between the load and the launch tube 1 during launch is measured by the signal change of the stress measuring element. This allows for accurate measurement of the contact force between the nozzle end of the launch tube 1 and the load during launch, providing experimental data support for establishing a mathematical model of the contact force during the separation process between the launch vehicle platform and the load, and improving the accuracy and reliability of the launch trajectory design of the load 7.

[0054] The structural components required for this measurement method can be directly installed at the inlet of the launch tube 1 without affecting the original launch system and load 7. It is especially suitable for small-scale model water tank tests. Usually, the size of the model is small under a certain scaling ratio in water tank tests, and conventional force balances do not have the space and conditions for installation.

[0055] Example 2:

[0056] like Figures 1-7 As shown, the method for measuring the contact force during the load launch process in dry launch according to this embodiment includes the following steps:

[0057] Step 1: Install the nozzle mounting component 3 at the outlet of the launch tube 1. A force-measuring ring assembly 4 is mounted on the nozzle mounting component 3 via shear force sensors 2. A sealing ring 43 is installed between the force-measuring ring assembly 4 and the end of the launch tube 1. The two shear force sensors 2 are symmetrically arranged about the diameter of the launch tube 1, and the line connecting the centers of the shear force sensors 2 passes through the axis of the launch tube 1. Figure 7 As shown.

[0058] Specifically, by adjusting the installation position of the nozzle mounting part 3 on the launching tube 1, the compression state of the sealing ring 43 and the gap between the force measuring ring assembly 4 and the end of the launching tube 1 are adjusted. When the nozzle mounting part 3 and the launching tube 1 are threadedly connected, the installation position of the nozzle mounting part 3 on the threaded surface of the launching tube 1 is adjusted by rotation.

[0059] Step 2: Adjust the concentricity of the force measuring ring assembly 4 and the launching tube 1 to make them concentric, and adjust the levelness of the two shear force sensors 2.

[0060] Step 3: Set the stress measurement element on the shear sensor 2.

[0061] Step 4: Suspend the standard weight on the force ring assembly 4. The downward direction of the standard weight is perpendicular to the direction of the line connecting the centers of the two shear force sensors 2. Record the signal change of the stress measuring element. Change the signal output of the stress measuring element by changing the total mass of the standard weight. Fit the linear change curve between the signal of the stress measuring element and the total mass of the standard weight.

[0062] Step 5: After the load 7 is loaded into place, the sealing plate 5 is installed on the outside of the force measuring ring assembly 4 through the pressing ring 6, so that the sealing plate 5, the force measuring ring assembly 4 and the launching tube 1 form a closed space. After the airtightness test is performed to confirm that the seal is good, the launching tube 1 is placed in water and the load 7 is launched. The processor receives and records the signal data of the stress measuring element during the launch of the load 7. The contact force on the corresponding force measuring ring assembly 4 is obtained by the linear change curve between the signal and the total mass of the standard weight.

[0063] Furthermore, in step five, the sealing sheet 5 is an aluminum film.

[0064] The measurement method of this embodiment, by installing a sealing ring 43 between the force ring assembly 4 and the end of the launch tube 1, and by installing a sealing sheet 5 on the outside of the force ring assembly 4 through a press-fit ring 6, forms a closed space with the sealing sheet 5, the force ring assembly 4 and the launch tube 1, which can be applied to the requirements of the underwater dry launch mode of the payload 7 and ensures the watertightness of the launch tube 1.

[0065] In contrast to dry-wet firing, wet firing does not require the installation of sealing ring 43, pressure ring 6 and sealing sheet 5.

[0066] Example 3: Based on Examples 1 and 2, the measurement method and the structural devices used in the measurement method are further explained.

[0067] Step 1: Install the nozzle mounting component 3 at the outlet of the launch tube 1. Install the force measuring ring assembly 4 on the nozzle mounting component 3 through the shear force sensor 2. The two shear force sensors 2 are symmetrically arranged about the diameter of the launch tube 1, and the direction of the line connecting the centers of the shear force sensors 2 passes through the axis of the launch tube 1.

[0068] Specifically, launch tube 1 is a component of a UUV (Unmanned Underwater Vehicle) or other delivery platform. Torpedoes and other weapon payloads are located inside launch tube 1. The inner wall of launch tube 1 is smooth. The fit between payload 7 and launch tube 1 is a hard contact. The inner diameter of launch tube 1 is slightly larger than the outer diameter of payload 7. When payload 7 is placed in launch tube 1, its state is as follows: Figure 5 As shown.

[0069] Furthermore, in step one, the nozzle mounting component 3 is ring-shaped and is fixedly installed at the outlet of the transmitting tube 1 by means of a threaded connection. Specifically, the nozzle mounting component 3 is connected to the shear force sensor 2, and the force measuring ring assembly 4 is connected to the shear force sensor 2 by fasteners. In this step, the fasteners do not need to be fully tightened.

[0070] Furthermore, in step one, when measuring the contact force in the vertical direction, the two shear force sensors 2 are set in the horizontal direction, as follows: Figure 1 As shown; when measuring the contact force in the horizontal direction: the two shear force sensors 2 are set in the vertical direction, as shown. Figure 2 As shown.

[0071] By setting up shear force sensors 2 in two directions, the contact force at different positions during the launch of load 7 can be measured, further increasing the richness of the measurement data and making the test data support more comprehensive.

[0072] Furthermore, such as Figure 8 As shown, the structure of the shear force sensor 2 is as follows: it includes a rectangular block body 20. One end of the block body 20 is connected to the pipe mounting component 3 along its length, and the other end of the block body 20 is connected to the force measuring ring assembly 4 along its length. A weakening groove 21 is provided in the middle of the block body 20, which makes the shear force sensor 2 form a parallel beam structure. The two sides of the weakening groove 21 along its length are the first stress concentration surface 22 and the second stress concentration surface 23, respectively. The center of the shear force sensor 2 is located at the central section of the weakening groove 21. The central section is parallel to the first stress concentration surface 22 and the second stress concentration surface 23. The first stress concentration surface 22 and the second stress concentration surface 23 are used to bear the stress on the shear force sensor 2 when a standard weight is applied.

[0073] Step 2: Adjust the concentricity of the force measuring ring assembly 4 and the launching tube 1 to make them concentric, and adjust the levelness of the two shear force sensors 2.

[0074] Specifically, a cylindrical positioning model with an outer diameter equal to the minimum inner diameter of the force-measuring ring assembly 4 is used for positioning. The position of the force-measuring ring assembly 4 is fine-tuned to ensure coaxiality between the force-measuring ring assembly 4 and the transmitting tube 1. Simultaneously, the horizontality of the shear force sensor 2 is adjusted to ensure that, when measuring contact force in the vertical direction, the first stress concentration surface 22 and the second stress concentration surface 23 are parallel to the horizontal plane; when measuring contact force in the horizontal direction, the first stress concentration surface 22 and the second stress concentration surface 23 are parallel to the vertical plane. Then, the fasteners are tightened. The force ring assembly 4 is installed at the inlet of the launch tube 1, with its minimum inner diameter being equal to that of the launch tube 1. The force ring assembly 4 is connected to the launch tube 1 via the shear force sensor 2. When subjected to contact force, it will displace relative to the launch tube 1. There is a gap between the end faces of the force ring assembly 4 and the launch tube 1. When the shear force sensor 2 deforms, this gap serves as the deformation space for the force ring assembly 4. When a dry launch load 7 is required, this gap is also used to install the sealing ring 43. The sealing ring 43 is made of soft material, ensuring watertightness while allowing for a certain amount of deformation.

[0075] Step 3: Set the stress measurement element on the shear sensor 2.

[0076] Furthermore, the stress measuring element is a strain gauge, which is attached to the first stress concentration surface 22 and the second stress concentration surface 23, and the signal of the stress measuring element is a voltage signal.

[0077] Specifically, when the load 7 is launched from the launch tube 1, the stress measuring element is used to measure the force on the shear sensor 2 when the load 7 comes into contact with the force ring assembly 4, thereby reflecting the magnitude of the contact force on the force ring assembly 4. The load 7 mentioned here is either a weapon load model in the water tank test phase or an actual weapon load, depending on the specific test site and conditions. The load 7 is suitable for different rotating body shapes. The stress measuring element is a strain gauge, and the signal change of the stress measuring element is a voltage signal. Four strain gauges are set on a shear sensor 2. Two strain gauges are set on the first stress concentration surface 22 along the length of the block body 20, and each strain gauge corresponds to the thinnest position. Two strain gauges are set on the second stress concentration surface 23 along the length of the block body 20, and each strain gauge also corresponds to the thinnest position. The four strain gauges form a Wheatstone bridge. The output voltage signal change of the bridge is used to reflect the force on the shear sensor 2, thereby measuring the contact force between the load 7 and the end of the launch tube 1.

[0078] Step 4: Suspend the standard weight on the force ring assembly 4. The downward direction of the standard weight is perpendicular to the direction of the line connecting the centers of the two shear force sensors 2. Record the signal change of the stress measuring element. Change the signal output of the stress measuring element by changing the total mass of the standard weight. Fit the linear change curve between the signal of the stress measuring element and the total mass of the standard weight.

[0079] Specifically, in this step, the total mass of the standard weights suspended on the force ring assembly 4 is used to simulate the magnitude of the contact force when the load 7 comes into contact with the force ring assembly 4.

[0080] Step 5: After the load 7 is loaded into place, the launching tube 1 is placed in the water and the load 7 is launched. The processor receives and records the signal data of the stress measuring element during the launch of the load 7. The contact force on the corresponding force ring assembly 4 is obtained by the linear change curve between the signal and the total mass of the standard weight.

[0081] Specifically, when the load 7 passes through the force ring assembly 4 after being launched, the force ring assembly 4 will undergo slight displacement after being subjected to force. This displacement will cause slight deformation of the shear force sensor 2, resulting in a voltage difference between the strain gauges (stress measuring elements) on the first stress concentration surface 22 and the second stress concentration surface 23 of the shear force sensor 2. The magnitude of the voltage difference can reflect the magnitude of the contact force on the force ring.

[0082] During the launch process, the load will be subjected to external forces and will also generate radial jitter or vibration. During the launch of the load 7, the contact force between the load 7 and the force measuring ring assembly 4 is constantly changing. The stress measuring element outputs one or more data signals during the launch of the load 7. Based on the magnitude of the signal and the curve calibrated by the weights in step four, the contact force applied by the load 7 to the force measuring ring assembly 4 is obtained.

[0083] Furthermore, such as Figure 6 As shown, the structure of the force measuring ring assembly 4 is as follows: it includes a force measuring ring body 41, the inner diameter of the force measuring ring body 41 is larger than the inner diameter of the transmitting tube 1, the force measuring ring body 41 is connected to the tube mounting part 3 through the shear force sensor 2, the inner surface of the force measuring ring body 41 is installed with a force measuring inner ring 42, the inner diameter of the middle part of the force measuring inner ring 42 is the same as the inner diameter of the transmitting tube 1, and the inner surfaces at both ends of the force measuring inner ring 42 are provided with transition inclined surfaces 44 that cooperate with the inner surface of the force measuring ring body 41.

[0084] Specifically, the minimum inner diameter of the force-measuring inner ring 42 is also the minimum inner diameter of the force-measuring ring assembly 4. The force-measuring inner ring 42 is assembled by combining a force-measuring ring body 41 with an inner diameter greater than that of the launch tube 1 and a force-measuring inner ring 42 with an inner diameter equal to that of the launch tube 1. This ensures the stability of the force-measuring ring assembly 4 while minimizing the contact position with the load 7, allowing for more accurate measurement of the contact force between the load 7 and the nozzle of the launch tube 1. A transition slope 44 is provided to ensure that the load 7 contacts the force-measuring ring without jamming. The overall shape of the force-measuring ring assembly 4 is such that the inner diameter gradually decreases from the edge to the center.

[0085] Furthermore, the inner force-measuring ring 42 is made of polytetrafluoroethylene (PTFE). This reduces the frictional resistance of the inner force-measuring ring 42 to the load 7 during launch.

[0086] When the column segment of load 7 moves to the inlet of the launching tube 1, under the guidance of the inner force measuring ring 42, the constraint force at the cross-section of the inlet of the launching tube 1 is entirely applied to the inner force measuring ring 42. Due to the gap between the force measuring ring assembly 4 and the launching tube 1, the force measuring ring assembly 4 will undergo slight displacement, causing the shear force sensor 2 to undergo slight deformation, resulting in a change in the output voltage of the strain gauge. The change in voltage is linearly related to the contact force. The magnitude of the contact force can be obtained by converting the linear change curve between the signal and the total mass of the standard weights.

[0087] The above description is an explanation of the present invention and not a limitation thereof. The scope of the present invention is defined by the claims. Within the scope of protection of the present invention, any form of modification may be made.

Claims

1. A method for measuring contact force during load launch, characterized in that: Includes the following steps: Step 1: Install the nozzle mounting part (3) at the outlet of the launch tube (1). Install the force measuring ring assembly (4) on the nozzle mounting part (3) through the shear force sensor (2). The minimum inner diameter of the force measuring ring assembly (4) is equal to the inner diameter of the launch tube (1). The two shear force sensors (2) are symmetrically arranged about the diameter of the launch tube (1), and the direction of the center line connecting the shear force sensors (2) passes through the axis of the launch tube (1). Step 2: Adjust the concentricity of the force ring assembly (4) and the launching tube (1) to make the force ring assembly (4) and the launching tube (1) concentric, and adjust the levelness of the two shear force sensors (2); Step 3: Set the stress measuring element on the shear sensor (2); Step 4: Suspend the standard weight on the force ring assembly (4). The downward direction of the standard weight is perpendicular to the direction of the line connecting the centers of the two shear force sensors (2). Record the signal change of the stress measuring element. Change the signal output of the stress measuring element by changing the total mass of the standard weight. Fit the linear change curve between the signal of the stress measuring element and the total mass of the standard weight. Step 5: After the load (7) is loaded into place, place the launching tube (1) in the water and launch the load (7). The processor receives and records the signal data of the stress measuring element during the launch of the load (7). The contact force of the corresponding force ring assembly (4) is obtained through the linear change curve between the signal and the total mass of the standard weight. The structure of the shear sensor (2) is as follows: it includes a rectangular block body (20), one end of the block body (20) is connected to the pipe mounting part (3) in the length direction, and the other end of the block body (20) is connected to the force measuring ring assembly (4). A weakening groove (21) is provided in the middle of the block body (20) to make the shear sensor (2) form a parallel beam structure. The two sides of the weakening groove (21) in the length direction are the first stress concentration surface (22) and the second stress concentration surface (23), respectively. The center of the shear sensor (2) is located at the center section of the weakening groove (21). The center section is parallel to the first stress concentration surface (22) and the second stress concentration surface (23). The first stress concentration surface (22) and the second stress concentration surface (23) are used to bear the stress on the shear sensor (2) when a standard weight is applied.

2. The method for measuring contact force during load launch as described in claim 1, characterized in that: When using a dry launch payload (7): In step one, when installing the force ring assembly (4), a sealing ring (43) is installed between the force ring assembly (4) and the end of the transmitter tube (1). In step five, after the load (7) is filled in place, the sealing plate (5) is installed on the outside of the force ring assembly (4) by the press ring (6), so that the sealing plate (5), the force ring assembly (4) and the launching tube (1) form a closed space. After the airtightness test is performed to confirm that the seal is good, the launching tube (1) is placed in the water.

3. The method for measuring contact force during load launch as described in claim 2, characterized in that: The sealing sheet (5) is an aluminum film.

4. The method for measuring contact force during load launch as described in claim 1, characterized in that: When measuring the contact force in the vertical direction, the two shear force sensors (2) are set in the horizontal direction.

5. The method for measuring contact force during load launch as described in claim 1, characterized in that: When measuring the contact force in the horizontal direction: the two shear force sensors (2) are set in the vertical direction.

6. The method for measuring contact force during load launch as described in claim 1, characterized in that: In step one: the pipe fitting (3) is ring-shaped and is fixedly installed at the outlet of the launching tube (1) by means of threaded connection.

7. The method for measuring contact force during load launch as described in claim 1, characterized in that: The stress measuring element is a strain gauge, which is attached to the first stress concentration surface (22) and the second stress concentration surface (23). The signal of the stress measuring element is a voltage signal.

8. The method for measuring contact force during load launch as described in claim 1, characterized in that: The structure of the force measuring ring assembly (4) is as follows: it includes a force measuring ring body (41), the inner diameter of the force measuring ring body (41) is larger than the inner diameter of the launching tube (1), the force measuring ring body (41) is connected to the tube mounting part (3) through the shear force sensor (2), the inner surface of the force measuring ring body (41) is equipped with a force measuring inner ring (42), the inner diameter of the middle part of the force measuring inner ring (42) is the same as the inner diameter of the launching tube (1), and the inner surfaces at both ends of the force measuring inner ring (42) are provided with transition inclined surfaces (44) that cooperate with the inner surface of the force measuring ring body (41).

9. The method for measuring contact force during load launch as described in claim 8, characterized in that: The inner ring (42) for measuring force is made of polytetrafluoroethylene.

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