Large-diameter cylinder inner surface strain gauge positioning marking device and method

Abstract

The invention discloses a device and a method for positioning and marking strain gauges on the inner surface of a large-diameter cylinder. Comprising an adjusting mechanism, an axial positioning mechanism connected with the adjusting mechanism, a circumferential positioning mechanism connected with the axial positioning mechanism, a supporting platform used for supporting the large-diameter cylinder and a controller used for controlling the axial positioning mechanism and the circumferential positioning mechanism to act, and the axial positioning mechanism extends into the large-diameter cylinder. The adjusting mechanism comprises a height adjusting assembly and a horizontal adjusting assembly connected to the height adjusting assembly, the axial positioning mechanism is connected to the horizontal adjusting assembly, and after positioning is completed, an electric stop valve is controlled to be opened to spray marks at the positioning position. The device is reliable in structure and good in use performance, realizes accurate positioning and marking along the axis and the circumferential direction, fills a gap for accurately positioning a strain gauge on the inner wall of a large-diameter cylinder in engineering, provides a convenient and simple technical scheme, and is reliable and convenient to operate.

Description

Technical Field

[0001] This invention relates to the field of measurement technology, and specifically to a device and method for positioning and marking strain gauges on the inner surface of a large-diameter cylinder. Background Technology

[0002] Cylindrical shell structures, such as rocket shells and spacecraft shells, are widely used in critical aerospace components. During service, these structural components often withstand complex loads in multiple directions, thus placing higher demands on their strength design.

[0003] In practical engineering applications, a crucial method for evaluating the strength of cylindrical shell structures is to accurately obtain the strain at key locations. Due to the complexity of the structure and stresses experienced by these cylindrical shells, strain gauges are typically distributed at different angles along the circumferential direction of the inner surface of the shell to provide a more comprehensive assessment of the stress conditions. However, in actual engineering and testing, strain gauges at different circumferential angles on the inner surface of the structure are usually determined based on the chord length. Due to calculation errors, actual measurement, and positioning errors, the strain gauges located using this method often deviate significantly from the required positions, greatly affecting the accuracy of the results. This fails to reflect the true strain conditions during the stress process, thus impacting the overall strength assessment of the structure and subsequent design optimization.

[0004] Therefore, how to provide a new device and method to accurately locate the bonding position of strain gauges on the inner surface of large-diameter cylinders, reduce positioning errors, and ensure the accuracy of strain results at key locations has become an urgent technical problem to be solved. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a device and method for positioning and marking strain gauges on the inner surface of a large-diameter cylinder.

[0006] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: a strain gauge positioning and marking device for the inner surface of a large-diameter cylinder, comprising an adjustment mechanism, an axial positioning mechanism connected to the adjustment mechanism, a circumferential positioning mechanism connected to the axial positioning mechanism, a support platform for supporting the large-diameter cylinder, and a controller for controlling the movement of the axial positioning mechanism and the circumferential positioning mechanism, wherein the axial positioning mechanism extends into the interior of the large-diameter cylinder. The adjustment mechanism includes a height adjustment component and a horizontal adjustment component connected to the height adjustment component, and an axial positioning mechanism is connected to the horizontal adjustment component.

[0007] Furthermore, the height adjustment component includes a fixed base, a mounting plate disposed on the fixed base, and mounting holes distributed in multiple rows on the mounting plate, with multiple mounting holes distributed along the vertical direction of the mounting plate. The horizontal adjustment component is disposed on the mounting plate by a positioning element.

[0008] Furthermore, the horizontal adjustment assembly includes a horizontal seat and a positioning hole formed on the horizontal seat. The horizontal adjustment assembly is connected to the height adjustment assembly by means of a positioning element passing through the positioning hole and the mounting hole. The axial positioning mechanism is set on the horizontal seat.

[0009] Furthermore, the axial positioning mechanism includes a connecting slide plate, an electric push rod mounted on the connecting slide plate, and a push rod controller for controlling the movement of the electric push rod, while the circumferential positioning mechanism is connected to the telescopic end of the electric push rod.

[0010] Furthermore, the circumferential positioning mechanism includes an adapter plate, a hydraulic motor connected to the adapter plate, a pin connected to the output end of the hydraulic motor, a laser displacement sensor mounted on the outer wall of the pin, and an encoder connected to the end of the pin. The adapter plate is connected to the electric push rod of the axial positioning mechanism.

[0011] Furthermore, a spline is provided on the lower end face of the pin, and a keyway is provided on the output end of the hydraulic motor. The hydraulic motor drives the pin to rotate through the cooperation of the spline and the keyway.

[0012] Furthermore, the encoder is connected to the pin shaft via a coupling.

[0013] Furthermore, a groove is provided on the outer wall of the pin, and the laser displacement sensor is installed in the groove. Furthermore, a high-pressure tank is detachably mounted on the side of the pin, and a nozzle is connected to the open end of the high-pressure tank. An electric shut-off valve is installed between the nozzle and the high-pressure tank, and the high-pressure tank is installed in the middle of the pin.

[0014] The present invention also provides a positioning and marking method based on a positioning and marking device for strain gauges on the inner surface of a large-diameter cylinder, comprising the following steps: S1: Place the large-diameter cylinder on the support platform and make preliminary adjustments to the positions of the axial positioning mechanism and the circumferential positioning mechanism; S2: The controller adjusts the spatial position of the entire device based on the information fed back by the laser displacement sensor, so that the axis of the device coincides with the axis of the large-diameter cylinder; S3: The electric push rod is controlled by the push rod controller to move to several positions along the axial direction of the large-diameter cylinder. The angle information fed back by the encoder is received through wireless signal transmission. The hydraulic motor directly drives the pin shaft, thereby driving the rotation of the laser displacement sensor and realizing the precise positioning of the inner wall of the cylinder at multiple positions along the axial and circumferential directions. S4: After positioning is completed, the electric shut-off valve is opened to spray markings at the positioning point.

[0015] The present invention has the following beneficial effects: The present invention provides a positioning and marking device and method for strain gauges on the inner surface of a large-diameter cylinder. It has a reliable structure and good performance. It uses an electric push rod, a hydraulic motor, a pin shaft, an encoder, and a laser displacement sensor to achieve precise positioning along the axis and circumference. At the same time as precise positioning, the positioning points can be marked, which facilitates the pasting of strain gauges. It fills the gap in the precise positioning of strain gauges on the inner wall of large-diameter cylinders in engineering, and provides a convenient and simple technical solution. It is reliable and convenient to operate. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 To adjust the schematic diagram of the mechanism; Figure 3 This is a schematic diagram of the axial positioning mechanism and the circumferential positioning mechanism in this invention; Figure 4 This is a schematic diagram of the structure used for marking and positioning in this invention; Figures 1 to 4 The reference numerals in the attached figures represent: 1-adjustment mechanism, 2-axial positioning mechanism, 3-circumferential positioning mechanism, 4-support platform, 5-large diameter cylinder, 6-controller, 10-height adjustment component, 11-level adjustment component, 100-fixed seat, 101-mounting plate, 102-mounting hole, 110-level seat, 111-positioning component, 20-connecting slide plate, 21-electric push rod, 22-push rod controller, 30-adapter plate, 31-hydraulic motor, 32-pin, 33-laser displacement sensor, 34-encoder, 35-spline, 36-keyway, 37-coupling, 38-high pressure tank, 39-nozzle, 40-electric shut-off valve. Detailed Implementation

[0017] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0018] like Figure 1As shown, a strain gauge positioning and marking device for the inner surface of a large-diameter cylinder includes an adjustment mechanism 1, an axial positioning mechanism 2 connected to the adjustment mechanism 1, a circumferential positioning mechanism 3 connected to the axial positioning mechanism 2, a support platform 4 for supporting the large-diameter cylinder 5, and a controller 6 for controlling the actions of the axial positioning mechanism 2 and the circumferential positioning mechanism 3. The axial positioning mechanism 2 extends into the interior of the large-diameter cylinder 5. The axial positioning mechanism 2 is connected to the adjustment mechanism 1 and is responsible for positioning the strain gauge axially, i.e., along the length of the cylinder. The circumferential positioning mechanism 3 is connected to the axial positioning mechanism 2 and is responsible for positioning the strain gauge circumferentially, i.e., around the circumference of the cylinder. The controller 6 controls the actions of the axial positioning mechanism 2 and the circumferential positioning mechanism 3 to achieve precise positioning of the strain gauge. The controller 6 uses an STM32 microcontroller. By setting up the support platform 4, the cylinder can be fixed, facilitating the positioning of the cylinder.

[0019] like Figure 2 As shown, the adjustment mechanism 1 includes a height adjustment component 10 and a horizontal adjustment component 11 connected to the height adjustment component 10. An axial positioning mechanism 2 is connected to the horizontal adjustment component 11. The mounting plate 101 serves as a bridge connecting the fixed base 100 and the horizontal adjustment component 11, providing a flat surface for mounting and positioning the horizontal adjustment component 11. Multiple rows of mounting holes 102 on the mounting plate 101 allow the horizontal adjustment component 11 to be installed and adjusted at different heights and positions to accommodate cylinders of different sizes or different measurement needs. The mounting holes 102 are distributed along the vertical direction of the mounting plate 101, meaning that the horizontal adjustment component 11 can be fine-tuned in the vertical direction to meet height adjustment requirements. Furthermore, the multiple rows of mounting holes 102 also mean that fine-tuning can be performed in the horizontal direction.

[0020] The height adjustment assembly 10 includes a fixed base 100, a mounting plate 101 disposed on the fixed base 100, and mounting holes 102 distributed in multiple rows on the mounting plate 101. The mounting holes 102 are distributed in multiple rows along the vertical direction of the mounting plate 101. The horizontal adjustment assembly is disposed on the mounting plate 101 by a positioning member 111.

[0021] The horizontal adjustment assembly 11 includes a horizontal seat 110 and a positioning hole opened on the horizontal seat 110. The horizontal adjustment assembly 11 is connected to the height adjustment assembly 10 by a positioning member 111 passing through the positioning hole and the mounting hole 102. The axial positioning mechanism 2 is set on the horizontal seat 110.

[0022] like Figure 3As shown, the axial positioning mechanism 2 includes a connecting slide plate 20, an electric push rod 21 mounted on the connecting slide plate 20, and a push rod controller 22 for controlling the movement of the electric push rod 21. A circumferential positioning mechanism 3 is connected to the telescopic end of the electric push rod 21. The push rod controller 22 is communicatively connected to a controller 6, which sends action commands to the push rod controller 22, which then controls the electric push rod 21 to perform corresponding actions. The connecting slide plate 20 is the basic component of the axial positioning mechanism 2, serving as a connection and support. The connecting slide plate 20 is fixedly connected to the electric push rod 21, providing a stable mounting platform for the electric push rod 21. The electric push rod 21 is the core component of the axial positioning mechanism 2, responsible for axial positioning and adjustment. By controlling the telescopic movement of the electric push rod 21, the axial position of the connecting slide plate 20 and its connected components can be precisely adjusted. The push rod controller 22 is the key component for controlling the movement of the electric push rod 21. It receives signals or commands from the outside and controls the telescopic movement of the electric push rod 21 according to these signals or commands. By adjusting the parameters or program of the push rod controller 22, precise control can be achieved over parameters such as the speed, position, and stroke of the electric push rod 21.

[0023] This invention preferably uses an electric linear actuator 21. Compared to pneumatic and hydraulic actuators, the electric linear actuator is compact and programmable, enabling high-speed, high-load, precise control, and acceleration / deceleration settings. The electric linear actuator 21 utilizes the rotational force of a motor to convert electricity into linear torque. By rotating the actuator's screw with the motor, the core moves linearly, generating a push / pull effect on the load. Compared to hydraulic and pneumatic actuators, the electric linear actuator 21 is the most reliable, requiring virtually no maintenance. Furthermore, the electric linear actuator 21 is equipped with feedback sensors, allowing the actuator to actively transmit its stroke position to the control system. These output signal sensors also allow the control box to accurately adjust the actuator's stroke at any time, thereby precisely positioning the axial position of the cylinder.

[0024] The circumferential positioning mechanism 3 includes a transition plate 30, a hydraulic motor 31 connected to the transition plate 30, a pin 32 connected to the output end of the hydraulic motor 31, a laser displacement sensor 33 mounted on the outer wall of the pin 32, and an encoder 34 connected to the end of the pin 32. The transition plate 30 is connected to the electric push rod 21 of the axial positioning mechanism 2. The transition plate 30 acts as a connecting component, serving as a bridge. On one hand, it connects to the electric push rod 21 of the axial positioning mechanism 2, transmitting the thrust of the electric push rod 21 to the circumferential positioning mechanism 3; on the other hand, the transition plate 30 also provides a stable mounting platform for components such as the hydraulic motor 31 and the pin 32, ensuring their coordinated operation. The hydraulic motor 31 is the power source of the circumferential positioning mechanism 3. It converts the liquid pressure energy provided by the hydraulic pump into mechanical torque and speed, thereby driving the pin 32 to rotate. By controlling the input pressure and flow rate of the hydraulic motor 31, precise control of parameters such as the rotational speed and torque of the pin 32 can be achieved. Hydraulic motor 31 is preferably a hydraulic ball piston motor. Ball piston motors are characterized by simple structure, reliable operation, small size, light weight, impact resistance, long service life, stable low-speed operation, and stepless speed regulation, making them suitable for the working requirements of this invention. Pin 32 is the transmission component in the circumferential positioning mechanism 3. One end of it is connected to the output end of the hydraulic motor 31, and the other end is connected to the encoder 34 or other positioned components. Pin 32 transmits the power of the hydraulic motor 31 to the positioned component through rotational motion, achieving circumferential positioning and adjustment. Laser displacement sensor 33 is used to monitor the displacement or position change of pin 32 in real time. It accurately measures the distance or displacement between pin 32 and the sensor by emitting a laser beam and receiving the reflected signal. Laser displacement sensor 33 features high precision, high resolution, and non-contact measurement, enabling it to capture the movement and position change of pin 32 in real time, providing accurate feedback signals to the control system. Encoder 34 is used to measure the rotational angle or linear displacement of pin 32 and convert these mechanical movements into electrical or digital signals. By reading the output signal of encoder 34, parameters such as the rotational speed and position of pin 32 can be calculated in real time, providing precise position feedback signals to the control system. Encoder 34 plays a crucial role in the circumferential positioning mechanism 3, ensuring the precise position and stability of the positioned component in the circumferential direction.

[0025] The lower end face of the pin 32 is provided with a spline 35, and the output end of the hydraulic motor 31 is provided with a keyway 36. The engagement of the spline 35 and the keyway 36 enables the hydraulic motor 31 to drive the pin 32 to rotate. The structure is compact, saves installation space, and also improves the torsional strength and stability of the transmission.

[0026] The encoder 34 is connected to the pin 32 via a coupling 37. The encoder 34 and the pin 32 are linked, and the encoder can feed back rotation signals to the controller 6 in real time. The controller 6 receives the signals from the encoder 34 and drives the pin 32 directly through the hydraulic motor 31, thereby driving the rotation of the laser displacement sensor 33 to achieve precise positioning of the inner wall of the circumference at different angles.

[0027] A groove is formed on the outer wall of the pin 32, and the laser displacement sensor 33 is installed in the groove. The laser source is located on the axis of the pin 32, and the signal from the laser displacement sensor 33 is transmitted to the controller 6. In order to ensure that the axis of the positioning device coincides with the axis of the cylinder, the position of the adjustment mechanism 1 in the height and horizontal direction can be adjusted according to the displacement signal transmitted by the displacement sensor, thereby improving the positioning efficiency.

[0028] In addition, such as Figure 4 As shown, a high-pressure tank 38 is detachably mounted on the side of the pin. A nozzle 39 is connected to the open end of the high-pressure tank 38, and an electric shut-off valve 40 is installed between the nozzle 39 and the high-pressure tank 38. The high-pressure tank 38 is installed in the middle of the pin. The high-pressure tank 38 is filled with polyvinyl alcohol powder. Due to its good adhesion to metal surfaces and ease of cleaning, during the rotation of the pin, the positioning points can be marked with polyvinyl alcohol powder according to the pin's movement positioning information, facilitating subsequent bonding of strain gauges. Furthermore, the use of this powder marking will not cause scratches or damage to the inner wall of the cylinder. Figure 3 The high-pressure tank 38 was not installed in the middle.

[0029] The high-pressure tank 38 has a groove on the side facing the pin shaft that matches the shape of the pin shaft. It is fixed with screws using ear plates and clamps. The high-pressure tank 38 is installed in the middle position of the pin shaft to facilitate the positioning of the high-pressure tank 38 after the pin shaft is displaced, thereby improving the accuracy of spray positioning.

[0030] The present invention also provides a positioning and marking method based on a positioning and marking device for strain gauges on the inner surface of a large-diameter cylinder, comprising the following steps: S1: Place the large-diameter cylinder 5 on the support platform 4, and make preliminary adjustments to the positions of the axial positioning mechanism 2 and the circumferential positioning mechanism 3; S2: The controller 6 adjusts the spatial position of the entire device according to the information fed back by the laser displacement sensor 33, so that the axis of the device coincides with the axis of the large diameter cylinder 5. S3: The electric push rod 21 is controlled by the push rod controller 22 to move to several axial positions of the large-diameter cylinder 5. The angle information fed back by the encoder 34 is received through wireless signal transmission. The hydraulic motor 31 directly drives the pin 32, thereby driving the rotation of the laser displacement sensor 33, so as to achieve precise positioning of the inner wall of the cylinder at multiple positions along the axial and circumferential directions.

[0031] S4: After positioning is completed, the electric shut-off valve 40 is opened to spray markings at the positioning point.

[0032] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A positioning and marking device for strain gauges on the inner surface of a large-diameter cylinder, characterized in that, It includes an adjustment mechanism (1), an axial positioning mechanism (2) connected to the adjustment mechanism (1), a circumferential positioning mechanism (3) connected to the axial positioning mechanism (2), a support platform (4) for supporting a large-diameter cylinder (5), and a controller (6) for controlling the movement of the axial positioning mechanism (2) and the circumferential positioning mechanism (3), wherein the axial positioning mechanism (2) extends into the interior of the large-diameter cylinder (5); The adjustment mechanism (1) includes a height adjustment component (10) and a horizontal adjustment component (11) connected to the height adjustment component (10), and the axial positioning mechanism (2) is connected to the horizontal adjustment component (11).

2. The large-diameter cylindrical inner surface strain gauge positioning and marking device according to claim 1, characterized in that, The height adjustment component (10) includes a fixed base (100), a mounting plate (101) disposed on the fixed base (100), and mounting holes (102) formed on the mounting plate (101) and arranged in multiple rows. The mounting holes (102) are distributed in multiple rows along the vertical direction of the mounting plate (101). The horizontal adjustment component (11) is disposed on the mounting plate (101) by a positioning member (111).

3. The large-diameter cylindrical inner surface strain gauge positioning and marking device according to claim 2, characterized in that, The horizontal adjustment assembly (11) includes a horizontal seat (110) and a positioning hole opened on the horizontal seat (110). The horizontal adjustment assembly (11) is connected to the height adjustment assembly (10) by a positioning member (111) passing through the positioning hole and the mounting hole (102). The axial positioning mechanism (2) is disposed on the horizontal seat (110).

4. The large-diameter cylindrical inner surface strain gauge positioning and marking device according to claim 1, characterized in that, The axial positioning mechanism (2) includes a connecting slide plate (20), an electric push rod (21) disposed on the connecting slide plate (20), and a push rod controller (22) for controlling the movement of the electric push rod (21). The circumferential positioning mechanism (3) is connected to the telescopic end of the electric push rod (21).

5. The large-diameter cylindrical inner surface strain gauge positioning and marking device according to claim 4, characterized in that, The circumferential positioning mechanism (3) includes a transition plate (30), a hydraulic motor (31) connected to the transition plate (30), a pin (32) connected to the output end of the hydraulic motor (31), a laser displacement sensor (33) set on the outer wall of the pin (32), and an encoder (34) connected to the end of the pin (32). The transition plate (30) is connected to the electric push rod (21) of the axial positioning mechanism (2).

6. The large-diameter cylindrical inner surface strain gauge positioning and marking device according to claim 5, characterized in that, The lower end face of the pin (32) is provided with a spline (35), and the output end of the hydraulic motor (31) is provided with a keyway (36). The hydraulic motor (31) drives the pin (32) to rotate through the cooperation of the spline (35) and the keyway (36).

7. The large-diameter cylindrical inner surface strain gauge positioning and marking device according to claim 5, characterized in that, The encoder (34) is connected to the pin (32) via a coupling (37).

8. The large-diameter cylindrical inner surface strain gauge positioning and marking device according to claim 5, characterized in that, A groove is provided on the outer wall of the pin (32), and the laser displacement sensor (33) is disposed in the groove.

9. The large-diameter cylindrical inner surface strain gauge positioning and marking device according to claim 5, characterized in that, A high-pressure tank (38) is detachably mounted on the side of the pin. A nozzle (39) is connected to the open end of the high-pressure tank (38). An electric shut-off valve (40) is provided between the nozzle (39) and the high-pressure tank (38). The high-pressure tank (38) is installed in the middle of the pin.

10. A positioning method based on the large-diameter cylindrical inner surface strain gauge positioning marking device according to any one of claims 1 to 9, characterized in that, Includes the following steps: S1: Place the large-diameter cylinder (5) on the support platform (4) and make preliminary adjustments to the positions of the axial positioning mechanism (2) and the circumferential positioning mechanism (3); S2: The controller (6) adjusts the spatial position of the entire device according to the information fed back by the laser displacement sensor (33) so that the axis of the device coincides with the axis of the large diameter cylinder (5); S3: The electric push rod (21) is controlled by the push rod controller (22) to move to several positions along the axial direction of the large diameter cylinder (5). The angle information fed back by the encoder (34) is received by the wireless signal transmission means. The pin shaft (32) is directly driven by the hydraulic motor (31), thereby driving the rotation of the laser displacement sensor (33) to achieve precise positioning of the inner wall of the cylinder along multiple positions in the axial and circumferential directions. S4: After positioning is completed, the electric shut-off valve (40) is opened to spray markings at the positioning point.

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